Download The Earth`s Crust and the Moho

Loihi (海底火山)
bamboozle (vt) : to deceive by underhanded methods 騙取, 騙使…: DUPE,
HOODWINK  bamboozlement (n)
dupe (n) : one that is easily deceived or cheated : FOOL (vt) to make a dupe
of
hoodwink (vt) : to deceive by false appearance : DUPE  hoodwinker
synonyms DUPE, GULL, TRICK, HOAX mean to deceive by underhanded
means. DUPE suggests unwariness in the person deluded. GULL stresses
credulousness or readiness to be imposed on (as through greed) on the part
of the victim. TRICK implies an intent to delude by means of a ruse or fraud
but does not always imply a vicious intent. HOAX implies the contriving of
an elaborate or adroit imposture in order to deceive.
yep Pronunciation: 'yep, or with glottal stop instead of p : YES (glottal (adj) :
of, relating to, or produced in or by the glottis『解剖』聲門)
poke (vt) 1 a (1) : PROD, JAB (以手指, 肘) 推, 伸<poked him in the ribs>
(2) : to urge or stir by prodding or jabbing (3) : to cause to prod : THRUST
<poked a stick at the snake> b (1) : PIERCE, STAB (2) : to produce by
piercing, stabbing, or jabbing 刺, 戳<poke a hole> c (1) : HIT, PUNCH
<poked him in the nose> (2) : to deliver (a blow) with the fist 2 a : to cause to
project 伸出<poked her head out of the window> b : to make (one's way) by
poking <poked his way through the ruins> c : to interpose or interject in a
meddlesome manner <asked him not to poke his nose into other people's
business> (vi) 1 a : to make a prodding, jabbing, or thrusting movement
especially repeatedly (以棍棒) 戳; 刺 b : to strike out at something ; 2 a : to
look about or through something without system : RUMMAGE <poking
around in the attic> b : MEDDLE
lava (n): molten rock that issues from a volcano or from a fissure in the earth's
surface, 熔岩, 火山岩 ; also : such rock that has cooled and hardened 凝固的
熔岩
pile (n): a long slender column usually of timber, steel, or reinforced concrete
一(大)堆, 一疊 (vt, vi) to lay or place in a pile : STACK 堆積, 成堆; 大量 
pile up
hard(adj) 
harden (vt, vi) to make hard or harder 使硬化, 變硬
eventually (adv) at an unspecified later time : in the end 結果, 最後; 終於
started out as …: to begin (its existence, function, shape) as 以… 開始
spit (v) spit or spat, spitting (vt) 1 a : to eject (as saliva) from the mouth :
EXPECTORATE 吐 (痰, 口水等) b (1) : to express (unpleasant or malicious
feelings) by or as if by spitting (2) : to utter with a spitting sound or scornful
expression <spat out his words> c : to emit as if by spitting 噴出; especially :
to emit (precipitation) in driving particles or in flurries <spit rain> (vi) 1 a (1) :
to eject saliva as an expression of aversion or contempt (2) : to exhibit
contempt b : to eject matter (as saliva) from the mouth : EXPECTORATE
expectorate (vi, vt) to discharge/ eject from the throat or lungs by coughing or
hawking (吐出, 吐痰)
liquid (n) a fluid (as water) that has no independent shape but has a definite
volume and does not expand indefinitely and that is only slightly compressible
液態, 液體 (adj) flowing freely like water ; having the properties of a liquid
液態的
emerge (vt) (vi)
1 : to become manifest 顯露, 出現
2 : to rise from or as if from an enveloping fluid : come out into view 浮現, 顯
現
3 : to rise from an obscure or inferior position or condition, 出人頭地; 脫穎而
出
4 : to come into being through evolution
seamount noun : a submarine mountain rising above the deep-sea floor
Triangles and Circles in the image below mark the approximate
locations of shield volcanoes of the main Hawaiian Islands
Lo'ihi seamount off the southeast coast of Hawai'i was known from
bathymetric surveys, and thought to be a large slump. However, dredging in
the 1970's recovered fresh lava samples, and the growing HVO seismic
network began to record earthquake swarms centered on Lo'ihi. Submersible
investigations have confirmed that Lo'ihi is actually the youngest Hawaiian
volcano, with its summit some 975 m below sea level (~4000 m above the
adjacent sea floor). Geochemical analyses of Lo'ihi samples show many of
them to be alkalic basalt. Lo'ihi has a flat top that may be an almost-filled
caldera, and as we'll see later this means it probably also has a magma
chamber. Many of the pillow lavas observed on Lo'ihi have little or no
sediment on them, a good indication of their recent formation.
This map shows bathymetry of Lo'ihi volcano, off the SE coast of the big
island of Hawai'i. The colors go from deep blue (~4500 m depth) to red
(~1000 m depth). Note the relatively flat summit that is pocked with a couple
of pit craters. This summit is probably a filled caldera. A seismic swarm in
July of 1996 was accompanied by the formation of a new pit crater near the
SW edge of the summit. This diagram was kindly provided by John Smith and
Terri Dunnebier of the Hawai'i Mapping Research Group.
General Information About Loihi
Loihi seamount, sometimes known as the "youngest volcano" in the
Hawaiian chain, is an undersea mountain rising more than 3000 meters above
the floor of the Pacific Ocean (Loihi is the red-capped nub that is pointed out
in the image above). Both Loihi and Kilauea volcanoes sit on the flank Mauna
Loa volcano, an older, larger, and still active volcano on the Big Island of
Hawaii. Loihi sits submerged in the Pacific off of the south-eastern coast of
the Big Island of Hawaii (this is the grey area labeled "Hawaii" at the top of
the image). Although hidden beneath the waves, Loihi is nevertheless taller
than Mt. St. Helens was prior to the catastropic volcanism there in 1980.
Before to the 1970's, Loihi was not known to be an active volcano. Instead,
it was thought to be a fairly common old seamount volcano of the type that
surrounds the Hawaiian islands. These latter volcanoes are similar in age (80100 million years old) to the sea floor upon which the Big Island of Hawaii sits.
This sea floor was itself created some 6000 km away on the undersea volcanic
mountain chain known as the East Pacific Rise. It has slowly moved northwestward to the present location of the Hawaiian Hotspot.
In 1970, our ideas about the seamount changed drastically following an
expedition that went to Loihi to study an earthquake swarm (intense, repeated
seismic activity) that had just occurred there. It was revealed that Loihi was a
young, active volcano, rather than an old dead seamount from a bygone aeon.
The volcano is mantled with young and old lava flows and is activly venting
hydrothermal fluids at it's summit and south rift zone. In August 1996 Loihi
volcano rumbled to life again with a vengence and has been intermittantly
active since then (as described below and elsewhere at this web site). In fact,
University of Hawaii scientists studying the seamount following the 1996
seismic swarm have found direct evidence of a volcanic eruption there in 1996,
making this the first confirmed historical eruption of the seamount.
Loihi shares the Hawaiian hot spot with its larger active siblings Mauna Loa
and Kilauea.
LOIHI WENT SEISMIC (July
1996):
During the summer of 1996, the
largest swarm of earthquakes ever
recorded on ANY Hawaiian
volcano shook Loihi seamount.
The swarm began on 17 July 1996;
to date, a total of over 4000
earthquakes have been recorded
by the Hawaii Volcano
Observatory (HVO) network.
Click HERE to see a location map
with of earthquake epicenters.
Learn more about this event and
recent activity at Loihi on the
1996 Loihi Eruption Pages.
The image to the left is a shaded
"Bathymetric map" of Loihi
Seamount as it now looks,
following the July 1996 eruption
and seismic event. The 3
depressions in the summit area are "pit craters"; the lower-left most crater was
formed in July 1996.
"Bathymetry" refers to the depth from the ocean's surface to features on the
seafloor. As you might expect, low numbers on a depth map refer to shallow
regions, or the high point on a submarine mountain such as Loihi. Shallow
regions are given in warm colors on this map; cool colors are the deep regions.
Map made by UH graduate student Nathan Becker using 1997 seabeam
bathymetry and the GMT program
A bulbous pillow lava from Loihi's summit area. Most of the rocks to be found
on Loihi's summit are coated by some amount of fine sediment and/or clay
minerals that come from the interaction of sea water with the rock's surface.
Only the very youngest rocks typically are sediment-free in this environment.
You can see examples of the latter on our Rock Gallery page. You can also
learn about the Chemical compositions of young rocks from Loihi at this web
site. Photo by Mike Garcia
bathymetry(n) : the measurement of water depth at various places in a body
of water; 海深測量術 also : the information derived from such measurements
海洋生物分佈學
 bathy·met·ric/bathy·met·ri·cal (adj)
slump (n) 2 : a downward slide of a mass of rock or land 下陷, 下掉 ; 1 a : a
marked or sustained decline especially in economic activity or prices 暴跌<a
post-election slump> b : a period of poor or losing play by a team or individual
競賽活動中表現失常的低潮期間, <one spring I was in a batting slump -Ted Williams>入;
nub (n) alteration of English dialect knub, 1 : KNOB, LUMP 小塊, 2 :
NUBBIN 小片, 小塊 ; 3 : GIST, POINT 要點, 要旨, 核心 小片
dredge (n)1 : an apparatus usually in the form of an oblong iron frame with an
attached bag net used especially for gathering fish and shellfish 2 : a machine
for removing earth usually by buckets on an endless chain or a suction tube 疏
濬機; 挖泥機 3 : a barge used in dredging 挖泥船 (vt) 1 a : to dig, gather, or
pull out with or as if with a dredge -- often used with up b : to deepen (as a
waterway) with a dredging machine 用挖泥機清除 (挖寬, 挖深); 疏濬 (港灣,
河川等)2 : to bring to light by deep searching -- often used with up <dredging
up memories> (vi) 1 : to use a dredge 2 : to search deeply
alkali (n) 1 : a soluble salt obtained from the ashes of plants and consisting
largely of potassium or sodium carbonate; broadly : a substance (as a
hydroxide or carbonate of an alkali metal) having marked basic properties -compare BASE 7a『化學』鹼
alkali metal: any of the univalent mostly basic metals of group I of the
periodic table comprising lithium, sodium, potassium, rubidium, cesium, and
francium
basalt 玄武岩: a dark gray to black dense to fine-grained igneous rock that consists of
basic plagioclase(『礦』斜長石), augite 輝石, and usually magnetite 磁鐵礦
igneous (adj) 1 : of, relating to, or resembling fire 似火的: FIERY 2 a :
relating to, resulting from, or suggestive of the intrusion or extrusion of
magma or volcanic activity b : formed by solidification of magma 1『地質』
火成的
2 <igneous rock>
magma (n) molten rock material within the earth from which igneous rock
results by cooling『地質』岩漿
caldera : a volcanic crater that has a diameter many times that of the vent and
is formed by collapse of the central part of a volcano or by explosions of
extraordinary violence『地質』火山口
Rock —Aggregation of solid matter composed of one or more of the minerals
forming the earth's crust. The scientific study of rocks is called petrology (岩
石學). Rocks are commonly divided, according to their origin, into three major
classes
igneous rock 火成岩,
sedimentary 沈積岩, and
metamorphic 變質岩
Igneous rock originates from the cooling and solidification of molten matter
from the earth's interior. Igneous rocks are commonly divided into classes by
texture. Some rocks are markedly granular (e.g., granite 花崗岩, syenite 正長
岩, 黑花崗石, diorite 閃長岩
, gabbro 飛白岩;輝長岩, peridotite 橄欖岩, and pyroxenite 輝石岩), while
others (e.g., basalt 玄武岩, trachite, dacite 似安山岩的火成岩, and andesite
安山岩) are composed of grains visible only under a microscope.
Sedimentary rocks originate from the consolidation of sediments derived in
part from living organisms but chiefly from older rocks of all classes
(ultimately the mineral elements are derived from igneous rocks alone). The
characteristic feature of sedimentary rocks is their stratification『地質』成層,
層理; they are frequently called stratified rocks. Sedimentary rocks made up of
angular particles derived from other rocks are said to have a clastic texture, in
contrast to pyroclastic sediments, which are particles of volcanic origin.
Metamorphic rocks originate from the alteration of the texture and mineral
constituents of igneous, sedimentary, and older metamorphic rocks under
extreme heat and pressure deep within the earth. Some (e.g., marble 大理石
and quartzite 石英岩) are massive in structure; those which have been subject
to the more extreme forms of metamorphism, are characterized by foliation『
地質』葉理(i.e., the arrangement of their minerals in roughly parallel planes,
giving them a banded appearance). A distinguishing characteristic of many
metamorphic rocks is their slaty cleavage. Among the common metamorphic
rocks are schist 片岩(e.g., mica 雲母 schist and hornblende 普通角閃石
schist), gneiss 片麻岩(sounds nice), quartzite 石英岩, slate 板石, and marble. 大
理石
Sedimentary rocks are made up of layers.
They may feel sandy or gritty and they break
relatively easily.
Metamorphic rocks are very hard. They
may have a sparkly appearance from crystal
embedded in them. The crystals will appear to
be lined up into different layers.
Igneous rocks are also sparkly, but the
crystals will be scattered throughout rather
than in layered bands.
archaeology(n)1 : the scientific study of material remains (as fossil relics,
artifacts, and monuments) of past human life and activities 考古學 2 : remains
of the culture of a people : ANTIQUITIES
paleontology(n) : a science dealing with the life of past geological periods as
known from fossil remains 古生物學, 化石學
Do Mountains Get Taller?
clear this up: 把這弄清楚, 澄清一下
puzzle (vt) to offer or represent to (as a person) a problem difficult to solve or
a situation difficult to resolve : challenge mentally; also : to exert (as oneself)
over such a problem or situation <they puzzled their wits to find a solution> (n)
something that puzzles, a question, a problem, 難題, (測智力的)拼圖遊戲,迷
惑, 困擾
the skin of an orange  the peel of an orange (蔬果的) 皮; 果皮
slide (vi) to move smoothly along a surface : SLIP, b : to coast over snow or
ice, c of a base runner in baseball : to fall or dive feet-first or head-first when
approaching a base
(vt) a : to cause to glide or slip 滑, 滑動 (n) 1 a : an act or instance of sliding 2 :
a sliding part or mechanism: (2) : a guiding surface (as a feeding mechanism)
along which something slides 幻燈片, 載玻片 3 a : the descent of a mass of
earth, rock, or snow down a hill or mountainside b : a dislocation in which one
rock mass in a mining lode has slid on another : FAULT 土崩; 地層滑動 4 a
(1) : a slippery surface for coasting (2) : a chute with a slippery bed 滑梯
collide (vi) 1 : to come together with solid or direct impact 碰撞 2 clash: 衝突
 collision
stick (vi) stuck, stuck 1 : to hold to something firmly by or as if by adhesion:
黏著, 附著 a : to become fixed in place by means of a pointed end b : to
become fast by or as if by miring or by gluing or plastering <stuck in the mud>
2 a : to remain in a place, situation, or environment 堅持 b : to hold fast or
adhere resolutely : CLING c : to remain effective d : to keep close in a chase
or competition 3 : to become blocked, wedged, or jammed.
Snail 蝸牛, 動作慢吞吞之人物
slug 蛞蝓ㄎㄨㄛˋ ㄩˊ蜒蚰的別名｜ㄢˊ ｜ㄡˊ軟體動物腹足類，無殼。身
體圓而長，表面多黏液，頭部有長短觸角各一對，晝伏夜出，以植物的
葉子為食。用肺呼吸，雌雄同體。或稱為鼻涕蟲、蛞蝓
wear (vt) 1 : to bear or have on the person 穿; 戴<wore a coat> …. 4 a : to
cause to deteriorate by use 磨損 b : to impair or diminish by use or attrition :
consume or waste gradually <letters on the stone worn away by weathering>
5 : to produce gradually by friction or attrition 磨破<wear a hole in the rug>
(vi) 1 a : to endure use : last under use or the passage of time <material that
will wear for years> b : to retain quality or vitality 2 a : to diminish or decay
through use <the heels of his shoes began to wear> b : to diminish or fail with
the passage of time <the effect of the drug wore off> <the day wore on> c : to
grow or become by attrition or use 磨損; 穿壞, 耗損
Himalayan mountains 喜馬拉雅山脈
tectonics 1 : geological structural features as a whole
2 a : a branch of geology concerned with the structure of the crust of a planet
(as earth) or moon and especially with the formation of folds and faults in it
『地質』大地構造學
Plates of the Earth
Division of the Earth's surface into a mosaic of moving plates,
according to plate tectonic theory. Boundaries between the plates are
actively spreading submarine ridges in the middle of the oceans,
subduction zones in ocean trenches or mountain ranges on the
continents, or margins where the plates slide past one another. Most of
the world's earthquakes occur at plate boundaries.
Eurasian : (adj)1 : of a mixed European and Asian origin歐亞混血的2 : of or
relating to Europe and Asia 歐亞的
Earth Structure
To understand how earthquakes are created you must first understand the
structure of the Earth. The Earth is made up of many sections. It has a core, the
mantle, the crust, the lithosphere, the Moho and the asthenosphere.
The core of the oblate spheroid that we call Earth is hypothesized to be made
of nickel-iron alloy. It was discovered by the Danish seismologist Inge
Lehmann after she studied the reflection and refraction of earthquake waves as
they travel through the earth.
The inner core, although it reaches temperatures of 10,000 degrees Celsius, is
solid due to the tremendous amount of pressure that is being put on it. As you
move away from the center, the Earth cools down. The outer core is liquid.
This is known because s-waves cannot travel through it.
p-wave: pressure wave ; s-wave: shear wave
The mantle is thought to consist of a dense, dark-colored, rock called
peridotite 橄欖岩. Even though no one has ever been down that deep in the
Earth scientists can assume this because of the way that earthquake waves
behave in the interior of the Earth. Also they can support their theory of the
materials of the mantle with the fact in some places on the Earth’s surface the
mantle has spilled out onto the surface. The mantle is much cooler than the
core and its temperature varies from 6,000 degrees Celsius to 1,500 degrees
Celsius. The rock in the mantle is not liquid but is a flexible solid that can be
moved if enough pressure is used for an extended period of time.
The crust is the layer that we live on it is thinner in proportion to the earth than
the shell is too an egg. This is the area that geologists study. It is known that
the crust is made up of two types of rock. The Basaltic rock covers the entire
Earth in a thin layer that is only six kilometers deep. In certain spots the
second layer that is made up of grantic rocks is built up onto of the basaltic
layer. The grantic layers can be up to forty kilometers thick. They are the
continents. Where there are no continents water flows over the basaltic rock to
form the oceans.
In between the crust and the Mantle is the Moho. It was discovered and named
after Adrija Mohorovicic. The Mohorovicic Discontinuity, as it is formally
known, is eight kilometers underneath the oceans, and up to thirty-two
kilometers thick underneath the continents.
Together the crust and the upper mantle make up the lithosphere. Recently
scientists discovered that all of the lithosphere is broken up into approximately
a dozen pieces called plates. These plates are constantly moving, whether it be
together, apart or side by side each other because of the layer that lies
underneath it. The layer is called the asthenosphere.
The asthenosphere is similar in composition to the lithosphere but unlike the
rock in the lithosphere asthenospheric rock is partially melted. This allows the
rock to flow very slowly. It is now the belief of scientists that the flow of the
rock of the asthenosphere takes the form of large slowly moving convection
currents. Within a current the rock material heats up, expands and rises. As it
rises it cools down and contracts. Since it is now cooler the density increases
and the rock once again sinks. As it sinks the rock material heats up again and
rises to continue the cycle.These currents causes the lithospheric plates to
move. The movement is the major cause of all of the world’s earthquakes.
lithosphere 岩界, 岩石圈(n): the solid part of a celestial body (as the earth);
specifically : the outer part of the solid earth composed of rock essentially like
that exposed at the surface and usually considered to be about 50 miles (80
kilometers) in thickness
asthenosphere (n): a hypothetical zone of a celestial body (as the earth) which
lies beneath the lithosphere and within which the material is believed to yield
readily to persistent stresses
Moho (n) short for Mohorovicic discontinuity, from Andrija Mohorovicic died
1936 Yugoslavian geologist : the boundary layer between the earth's crust and
mantle whose depth varies from about 3 miles (5 kilometers) beneath the
ocean floor to about 25 miles (40 kilometers) beneath the continents 莫荷不連
續面, 地球外殼與內殼之界線
Crust『地質』地殼
Mantle: 『地質』地幔 (地殼與地心間的地層)
Core 地核,
Lithosphere
The lithosphere is the outer solid part of the
earth, including the crust and uppermost
mantle. The lithosphere is about 100 km
thick, although its thickness is age dependent
(older lithosphere is thicker). The
lithosphere below the crust is brittle enough
at some locations to produce earthquakes by
faulting, such as within a subducted oceanic
plate.
Asthenosphere
The asthenosphere is the ductile part of the
earth just below the lithosphere, including
the lower mantle. The asthenosphere is
about 180 km thick.
(Image courtesy of Massey University)
Crust
The crust is the outermost major
layer of the earth, ranging from
about 10 to 65 km in thickness
worldwide. The uppermost 15-35
km of crust is brittle enough to
produce earthquakes.
Mantle
The mantle is the part of the
earth's interior between the
metallic outer core and the
crust.
Core
The innermost part of the
earth. The outer core extends
from 2500 to 3500 miles
below the earth's surface and
is liquid metal. The inner core
(Image from John Lahr, USGS Open-File Report 99- is the central 500 miles and is
solid metal.
132)
The Earth can be envisioned as consisting of a series of concentric layers,
each layer made up of material with a different composition and density
(Figure 1). The inner core which has a density of ~12.9 grams/cm3 forms the
innermost layer of our planet. It probably is composed of iron and nickel
either in a solid or dense liquid state. Though similar in composition and
density to the inner core, the outer core is thought to be entirely
liquid. Enveloping the core is the mantle which makes up ~82% of the volume
of the Earth. It has an average density of ~5.7 grams/cm3, and is composed of
an iron-magnesium silicate material called peridotite. The Mohorovicic
discontinuity (or simply the Moho) separates the mantle from the crust .
Forming the outer most layer of the Earth, the crust has a density of ~2.6~2.9 grams/cm3. Varying in thickness and composition it can be subdivided
into two prominent end members. One end member has an average thickness
of ~ 7 km, and is always found beneath the worlds oceans. Thus, it is not
surprising that it is often referred to as oceanic crust. Composed of
aluminosilicate materials that are relatively rich in iron and magnesium,
oceanic crust has an average basaltic composition. The other end member of
crust is always found in continental areas where it varies in thickness ranging
from ~35 km to ~70 km. Composed of aluminosilicate materials that are
relatively rich in potassium, continental crust has an average granodioritic
composition. In contrast to oceanic and continental crust, transitional types of
crust are typically intermediate in composition and thickness and are typical of
island arcs found in the world's oceans. [granodiorite (n): a granular
intrusive侵入的 quartzose (石英的,石英構成的) igneous rock intermediate between
granite and quartz-containing diorite(閃長岩) with plagioclase(斜長石)
predominant over orthoclase(正長石)]
Superimposed on the generalized structure of the Earth described in the
preceding section are two prominent layers that owe their existence to their
differing strengths. These two layers are called the asthenosphere and the
lithosphere. The asthenosphere, extending from about 100 to 200 km depth, is
made up entirely of very hot mantle material. In fact, it probably contains
about 1% or so of liquid. Under the ambient conditions that mantle is found in
the asthenosphere it would flow plastically, much like like your ink pen when
it is left exposed in your car dashboard on a hot sunny day. In contrast, the
overlying lithosphere, consisting of the lower(uppermost?) mantle and the
crust, is stronger, colder, and less dense than the asthenosphere. New
lithosphere is produced at mid-ocean ridges while old lithosphere is
assimilated back into the asthenosphere, either wholly or in part, as it
descends beneath island arcs. The mesosphere is that portion of the mantle
underlying the asthenosphere. It extends from about 200 to 2890 km
depth. From the above discussion see if you can pick out the lithosphere,
asthenosphere, mesophere, and inner and outer core in Figure 2.
Plates
Geologists have over the last 50-60 years have been able to document that
there are 7 major lithospheric plates, and many small microplates making up
the outer layer of the Earth. The 7 major lithospheric plates are the North
American, Euasian, South American, African, Indian-Australian, and Antarctic
plates. Of the many microplates the Juan De Fuca, Cocos, Nazca, Caribbean,
Philippine, Scotia, and Arabian plates are 7 common ones shown on tectonic
maps. On the map provided in Figure 3 see if you can find these 14 plates.
Plates of the Earth
Boundaries
All lithospheric plates terminate in two or more of three fundamentally
different types of boundaries ( Figure 3). The most salient aspects of each
type of boundary are illustrated and discussed below. [salient : moving by
leaps or springs 跳躍的: JUMPING 2 : jetting upward <a salient fountain> 3 a :
projecting beyond a line, surface, or level b : standing out conspicuously :
PROMINENT;突出的; 凸起的, 顯著的]
Divergent
Divergent boundaries are sites of mid-ocean ridges where two plates are
moving away from each other.
Convergent
Convergent boundaries are locations where one lithospheric plate descends
or is subducted beneath another. Such locations can be identified by a long
chains of volcanoes, and by a parallel bathymetrically low area in the sea floor
called a trench.
The Earth's Crust and the Moho
The outer shell, or crust, varies from 5 to 25 mi (8 to 40 km) in thickness,
and consists of the continents and ocean basins at the surface. The continents
are composed of rock types collectively called sial, a classification based on
their densities and composition. Beneath the ocean basins and the sial of
continents lie denser rock types called sima. The sial and sima together form
the crust, beneath which lies a shell called the mantle. The boundary between
the crust and the mantle is marked by a sharp alteration in the velocity of
earthquake waves passing through that region. This boundary layer is called
the Mohorovii discontinuity, or Moho. [sial : 矽鋁岩 ; sima : 地殼之下層]
The Earth's Mantle
Extending to a depth of c.1,800 mi (2,900 km), the mantle probably consists
of very dense (average c.3.9) rock rich in iron and magnesium minerals.
Although temperatures increase with depth, the melting point of the rock is not
reached because the melting temperature is raised by the great confining
pressure. At depths between c.60 mi and c.125 mi (100 and 200 km) in the
mantle, a plastic zone, called the asthenosphere, is found to occur. Presumably
the rocks in this region are very close to melting, and the zone represents a
fundamental boundary between the moving crustal plates of the earth's surface
and the interior regions. The molten magma that intrudes upward into crustal
rocks or issues from a volcano in the form of lava may owe its origin to
radioactive heating or to the relief of pressure in the lower crust and upper
mantle caused by earthquake faulting of the overlying crustal rock. Similarly,
it is thought that the heat energy released in the upper part of the mantle has
broken the earth's crust into vast plates that slide around on the plastic zone,
setting up stresses along the plate margins that result in the formation of folds
and faults (see plate tectonics ).
The Earth's Core
Thought to be composed of iron and nickel, the dense (c.11.0) core of the
earth lies below the mantle. The abrupt disappearance of direct compressional
earthquake waves, which cannot travel through liquids, at depths below
c.1,800 mi (2,900 km) indicates that the outer 1,380 mi (2,200 km) of the core
are molten. It is thought, however, that the inner 780 mi (1,260 km) of the core
are solid. The outer core is thought to be the source of the earth's magnetic
field: In the “dynamo theory” advanced by W. M. Elasser and E. Bullard, tidal
energy or heat is converted to mechanical energy in the form of currents in the
liquid core; this mechanical energy is then converted to electromagnetic
energy, which we see as the magnetic field.
Earth Statistics
Mass (kg)
5.976e+24
Mass (Earth = 1)
1.0000e+00
Equatorial radius (km)
6,378.14
Equatorial radius (Earth = 1)
1.0000e+00
Mean density (gm/cm^3)
5.515
Mean distance from the Sun (km)
149,600,000
Mean distance from the Sun (Earth = 1)
1.0000
Rotational period (days)
0.99727
Rotational period (hours)
23.9345
Orbital period (days)
365.256
Mean orbital velocity (km/sec)
29.79
Orbital eccentricity
0.0167
Tilt of axis (degrees)
23.45
Orbital inclination (degrees)
0.000
Equatorial escape velocity (km/sec)
11.18
Equatorial surface gravity (m/sec^2)
9.78
Visual geometric albedo
0.37
Mean surface temperature
15°C
Atmospheric pressure (bars)
1.013
Atmospheric composition
Nitrogen
77%
Oxygen
21%
Other
2%
albedo (n): reflective power; specifically : the fraction of incident radiation (as
light) that is reflected by a surface or body (as the moon or a cloud) 反照率
(行星或衛星反射出的光線與其接受到的光線之比)
Do Penguins Shiver?(企鵝會打冷顫嗎？)
have the air conditioner all the way up  將 air conditioner 冷氣一直調到最
高
get myself ready for  get ready for (doing something) 準備好做…
manage to (do something) (vi)…to succeed in accomplishing : CONTRIVE
設法, 圖法/圖謀去做 {contrive (vt) 1 a : DEVISE, PLAN <contrive ways of
handling the situation> b : to form or create in an artistic or ingenious manner
<contrived household utensils from stone> 2 : to bring about by stratagem or
with difficulty : MANAGE (vi) to make schemes }
live down there  live down in Antarctica {down : in a direction that is the
opposite of up: as a : SOUTHWARD b : to or toward a point away from the
speaker or the speaker's point of reference}
shiver (vi) 1 : to undergo trembling : QUIVER; 顫抖 2 : to tremble in the
wind as it strikes first one and then the other side (of a sail) (also vt)『航海』
使船靠近風帶而顫動 (n) 1 : an instance of shivering : TREMBLE 2 : an
intense shivery sensation especially of fear -- often used in plural with the
<horror movies give him the shivers>冷得發抖
vibrate: (vi) to move to and fro or from side to side (vt) to swing or move to
and fro
shake: (v) 1 : to move/vibrate irregularly to and fro, as the result of a blow or
shock
tremble: to shake involuntarily (as with fear or cold) : SHIVER
quiver: (vi) to shake or move with a slight trembling motion
oscillate: (vi) to swing backward and forward like a pendulum
fluctuate: (vi) to shift back and forth uncertainly ; flow in waves
vacillate: (vi) to sway through lack of equilibrium b : FLUCTUATE,
OSCILLATE
swing: (vt) to cause to move vigorously through a wide arc or circle <swing an
ax>
YA:Happy
Pudding:
sway: (vt) to swing slowly and rhythmically back and forth from a base
or pivot
undulate (vi) to form or move in waves : FLUCTUATE
waver (vi) 1 : to vacillate irresolutely between choices : fluctuate in opinion
Meaning to move from one direction to its opposite.
UNDULATE suggests a gentle wavelike motion <an undulating sea of grass>.
SWING implies a movement of something attached at one end or one side
<the door suddenly swung open>.
SWAY implies a slow swinging or teetering movement <trees swaying in the
breeze>.
OSCILLATE stresses a usually regular alternation of direction <an oscillating
fan>.
VIBRATE suggests the rapid oscillation of an elastic body under stress or
impact <the vibrating strings of a piano>.
FLUCTUATE suggests constant irregular changes of level, intensity, or value
<fluctuating interest rates>.
WAVER stresses irregular motion suggestive of reeling or tottering <the
exhausted runner wavered before collapsing>.
You bet : you can bet that … 你可在…(這上面)打賭  肯定是 …
-ster : noun combining form
1 : one that does or handles or operates <spinster> <tapster> <teamster>
2 : one that makes or uses <songster> <punster>
3 : one that is associated with or participates in <gamester> <gangster>
4 : one that is <youngster>
have more of a problem (doing A) than (doing B) 做 A 的問題 比 做 B 的
問題 還多 ; 做 A 比 做 B 的問題還來的多
the very bottom of …: …的 最 底部 . very (adj) -- used as an intensive
especially to emphasize identity <before my very eyes>真正的, 僅僅的, 確實
的, 就是那個的.
down jacket  down (n) 1 : a covering of soft fluffy feathers; also : these
feathers 絨毛; 羽絨 2 : something soft and fluffy like down 類似絨毛的柔
軟物
in lots of different ways  in different ways + in lots of ways
layer (n) 1 : one that lays (as a worker who lays brick or a hen that lays eggs)
舖東西的人 2 a : one thickness, course, or fold laid or lying over or under
another 層
trap (n) 1 : a device for taking game or other animals; especially : one that
holds by springing shut suddenly 陷阱 2 a : something by which one is caught
or stopped unawares; also : a position or situation from which it is difficult or
impossible to escape 詭計; 圈套(vt) 1 a : to catch or take in or as if in a trap :
ENTRAP b : to place in a restricted position : CONFINE 設陷阱捕 <trapped
in the burning wreck> 3 a : STOP, HOLD <these mountains trap rains and
fogs generated over the ocean> 留住,堵住
flatten out 把…弄平 (vt) to make flat: as a : to make level or smooth b : to
knock down; also : to defeat decisively c : to make dull or uninspired -- often
used with out d : to make (as paint) lusterless e : to stabilize especially at a
lower level
(vi) : to become flat or flatter: as a : to become dull or spiritless b : to extend in
or into a flat position or form c : to become uniform or stabilized often at a
new lower level -- usually used with out
a barrier against  barrier (n) something material that blocks or is intended
to block passage <highway barriers> <a barrier contraceptive>障礙物, 阻礙,
路障設置; 海關的關口; 賽馬場的出發柵, 隔閡. 2, b : a natural formation or
structure that prevents or hinders movement or action <geographic barriers to
species dissemination>自然屏障 <barrier beaches> <drugs that cross the
placental barrier>
the cold  the cold air. Example : the rich = the rich people
let some heat off :讓一些熱氣散出
bald (adj) lacking a natural or usual covering (as of hair, vegetation, or nap)
禿的, 光禿禿的, 禿頭的
coat( (n) 1 a : an outer garment worn on the upper body and varying in length
and style according to fashion and use 外套 b : something resembling a coat
2 : the external growth on an animal 動物的外皮, 毛皮 3 : a layer of one
substance covering another 外層 . (vt) to cover with a coat 用上衣罩上; to
cover or spread with a finishing, protecting, or enclosing layer 塗上一層
The Penguin FAQ
Here are a couple of answers to Frequently Asked Questions
about penguins I received from kids and penguin lovers. My
answers apply mainly to the two kinds of penguins I know best,
the Adelie penguins and the Emperor penguins. Just remember
that although I've lived with penguins for more than a year, I'm
no substitute for a real ornithologist...
Who discovered the Adelie or Emperor penguins ?
I don't know. The first discoverers of Antarctica saw many
on the shores, but it's also possible to see them farther
north, resting on floating pieces of ice, so even explorers of
southern seas who didn't reach Antarctica saw many in the
18th century. And sometimes penguins get lost and end up
in the wrong places. There was an Emperor penguin
spending the winter in Tasmania, alone, a few years ago.
Antarctica itself was thus discovered much later than
penguins.
AUSTRALIA
Adelie penguins are named after Adelie Land which was
named by French discoverer Dumont d'Urville after his wife,
Adèle, in 1840. So even if people had seen Adelie penguins
before him, they did not give them a specific name.
Captain Cook saw many King Penguins during his 1775 trip.
The biologist of the expedition, Forster, made many
drawings. 69 years later, Gray studied those drawings and
noticed one that was different: it was the first Emperor
penguin, thus the latin name Aptenodytes Forsteri.
Where does the word 'penguin' come from ?
The first animal called penguin was a flightless bird of the
Arctic sea, also known as the Great Auk, which was very
similar to a penguin in anatomy, although from a different
order of birds. It was hunted to extinction in the 1600s.
Then when explorers later discovered similar animals in the
southern seas, they named them the same way. The word
itself has muddy origin; it originally seemed to mean 'fat
one' in spanish/portuguese, and may come from either the
Welsh 'pen gwyn' (white head), from the Latin 'pinguis'
(fat); or from a corruption of 'pin-wing' (pinioned wings).
How many species of penguins are there ?
There are currently 17 species of Penguins, but fossil records
indicate that there used to be more in the past. The current
ones, all living in the southern hemisphere, are: Adelie,
African, Chinstrap, Emperor, Erect Crested, Fairy, Fjordland,
Galapagos, Gentoo, Humboldt, King, Macaroni, Magellanic,
Rockhopper, Royal, Snares Island, Yellow Eyed. I know well
only the Adelie and Emperor which lived in the vcinity of
Dumont d'Urville, but I have a few pictures of the Fairy (aka
Little Blue) and Yellow Eyed penguins on my Tasmanian
page.
Why aren't there penguins in the Arctic ?
Well, as you just read above, there used to be one flightless
bird called penguin, also known as the Great Auk, but it was
exterminated four centuries ago. The reason that there
aren't any is probably because of predators: penguins need
to go on land to nest and are quite defenceless with their
feet on the ground. Antarctica and other southern island are
devoid or have few land predators. The Arctic has bears,
wolves, foxes, rats and more...
Right: An adelie penguin fledging in autumn.
Are penguins mammals/birds/fish/...?
Here are a few clues: they lay eggs, they have feathers,
they breathe air, they have clawed feet, they have a beak...
Can you put the clues together ?
I had a good laugh recently when talking with two
veterinarians. One was certain that penguins are mammals
(like seals), the other was certain that penguins are fish. I
hope my pets don't ever get sick !
Do penguins have feathers ?
Yes they do, like all birds. Their feathers are very compact
and hard. When they are hot they ruffle them. And we could
often see them plucking out old feathers or scratching (they
have parasites like fleas and mites). On the picture on the
right you can see an Adelie penguin loosing its old feathers
before returning to sea, a process called fledging (or
feathering) that happens in november-december for
Emperors and march-april for Adelie penguins.
Why don't penguins get cold ?
Because they are fat ! Fat has two main purposes in the
body: it is a good insulator against cold and also it is a
reserve of energy. When the emperor penguins arrive in
autumn to stay the winter in Antarctica without eating,
about half of their bodyweight is made of a 4cm thick layer
of fat which they will use to withstand the long cold nights.
Also the structure of the penguin feathers gives them an
increased protection against cold: an outer layer of long
hard smooth feathers streamlined for fast swimming (that
also probably protects them from the wind), but underneath
is a layer of short fluffy down feathers providing better
insulation by trapping air.
Penguin chicks have very warm down feathers around their
body, but because they are smaller in size they seek
protection under the belly of a parent. When they grow
bigger they become more independent, staying in groups
called crèche. Also their down feathers are not waterproof
and they will die from the cold if they fall in water or mud
(see the picture below of a wet chick about to freeze to
death).
Right: An Emperor penguin chick overheating on a hot spring
day.
As a general rule: the colder the area they live in, the bigger
the penguin (you retain heat better when the
volume/surface ratio increases). Penguins can actually
overheat in Antarctica on warm summer days: when the
temperature is high they erect their feathers a lot to
increase airflow and heat exchange, they spread out far form
each others, they lay down on the ice (left picture) and they
pant; all signs I've seen in unlucky penguins kept in zoos.
Penguins, as a bird and like mammals, need to maintain a
precise and fairly high body temperature in order to keep
their metabolism working. The exception is that penguins
are known to decrease their body temperature when in
water, so as to minimize heat loss (which is proportional to
the difference of temperature between body and outside).
The penguins most exposed to the cold, the Emperors, need
to be social to survive the hardship of winter. During the
coldest and windiest winter nights, they pack together in
what is called a turtle: those in the middle are warm and
exchange position with those outside after a while.
Why do penguins have a white belly and black
back ?
Those colors make the penguins less visible when in the
water: as seen from above you see a black back above the
darkness of the deep sea; as seen from below you see a
light belly in front of the bright sky. Not too visible either
way (plenty of fish are like that). In other words it is a
defense mechanism when underwater. You've probably
noticed that it makes them quite visible on land, but Adelies
and Emperors don't really have predators there.
I don't know if the orange neck of the Emperors has a
specific function, but only adult penguins have it. Juvenile
penguins (one to two years of age) only have a grey neck.
Right: A sleeping adelie penguin, with his head under his
flipper.
Are penguins nocturnal ?
Not the Adelie or Emperor. Nocturnal activity is for most
animals a way to avoid predators, and those penguins don't
have predators when they are on the land, so they are
active during the day and rest at night. I don't know what
their activity at sea is. But what about the night in Antarctica
anyway ? In summer there isn't any night but the sun does
get lower on the horizon, and during those periods you can
indeed see Adelie penguins sleeping. It's also true for the
Emperors who spend the long winter nights huddled
together without moving but usually spread out on the ice a
little when there's the daily short hour of sunlight.
Other species of penguins that live on mainlands like in
South-Africa, South-America, Tasmania or New-Zealand
often have different behaviors. The Little Blue penguins
come out of their burrows before sunrise to go feed at sea
and come back after dark, but they probably spend the rest
of the night sleeping safely inside.
Adelie and emperors penguins sleep standing when they
have an egg, or sometimes laying down if they don't. Adelies
often rest their head under a flipper (see picture on right).
And they close their eyes.
Right: An Adelie penguin's egg hatching.
How big is a penguin's egg ?
An Adelie egg is slightly larger than a large hen's egg
and shaped the same. An Emperor's egg is much
bigger, up to 15cm long and 12cm diameter with a
conical top and a spherical bottom. The picture on the
right shows an Adelie penguin's egg hatching (see the
beak of the chick breaking the shell), and on the left
picture I'm holding an emptied Emperor's egg.
Emperors don't build nests: they carry their eggs
balanced on their feet, under their belly. They usually
don't move much, but if they take a big step, like to
catch their balance or to flee, then they drop their egg;
and once their egg is out of their pouch they will not
recognize it anymore. The egg promptly dies, freezes
and cracks and eventually falls into the bottom of the
sea when the sea ice melts off in spring. So we had the
possibility to recover and clean some abandoned eggs.
The first Emperor penguin egg was found on floating ice in
1840. Wilson saw it in a museum and recognized it as such
in 1905, and he also discovered the first rookery of Emperor
penguins in 1902 at Cape Crozier. In 1911 he decided to do
a winter trip to recover some eggs with Bowers and CherryGarrard, the only winter trip ever attempted in Antarctica,
which is recounted in the famous book: The worst journey in
the world
, one of the best read about Antarctica. They
barely survived. He later died on the return trip from the
South Pole with Captain Scott.
Are penguins endangered ?
It's hard to get an accurate count of Emperor and Adelie
penguins because there are many places where they live
that no human has ever visited, but apparently they are not
endangered, although their numbers fluctuate with the
availability of food in the sea. So for instance El Niño
episodes will have a strong negative influence on the
number of penguin chicks born. Adelie and Emperors don't
have land predators and humans leave them alone
nowadays, which is not true of most other species of
penguins who live on islands which have been colonized by
rats (everywhere), wild cats (like King Penguins at
Kerguelen), dogs (like blue penguins in New Zealand) or too
many tourists (like the penguins of the Galapagos).
Someone I met (not sure if he's a friend) told me he once
ate a penguin a long time ago and said it tasted something
like a mix between a chicken gone bad and a smelly fish,
and very fat at that ! So I won't give any recipe here... But
being bad to eat didn't protect them from human barbary.
Last century the whalers hunting in the southern indian
ocean (and maybe other areas) needed heat to melt off and
process whale fat. There isn't any wood on those southern
islands so they invented a barbaric device: a 'penguin press'
into which they would throw hundreds of live penguins,
crush them to extract their fat, and then use this fat as
combustible. The population of king penguins decreased
dramatically at that time but has since recovered. I'm glad
this time is over.
Where can I get or buy a penguin ?
Sorry, all species of penguins are protected, you can't get
one legally. And honestly, do you really think an animal that
spends half of its time swimming free in the ocean and the
other half in deep cold Antarctica would have a happy life in
a hot, dry and small home ? You'll have to satisfy yourself
with a stuffed teddy penguin.
Right: A wet Adelie penguin chick that will die in a few minutes.
How do you care for a penguin ?
How did you find a penguin in the first place ?!? True,
sometimes they end up washed ashore exhausted by storms
or wounded by predators or boats... If this is the case, be
careful that their bites can be very painful and they also give
mean punches with their bony flippers (they can break your
fingers easily). Grab them by the neck and hold them off the
ground for quick transportation. If you can, put a hood over
their eyes as they will immediately calm down.
In '92 my predecessors in DdU adopted two emperor chicks
they had found abandoned on the ice. They kept them
indoors and fed them leftover foods: raw fish at the
beginning but also canned fish and even meat. Those two
grew up to be the biggest and fattest penguins of the area
and were later released in the sea, quite healthy. So I guess
they are not particularly picky since their normal natural diet
consist of an oil specially secreted by the parents.
In New Zealand in 2000 several thousands little blue
penguins got contaminated by an oil spill; they were
collected and distributed among volunteers for cleaning and
care; they even put sweaters on them to keep them from
plucking they contaminated feathers. The survivors were
later released at sea.
Chicks depend on their parents for survival between
hatching and the growth of their waterproof feathers: about
seven weeks for Adélie chicks, 6 months for Emperors and
even more for King chicks. Chicks' down feathers are not
waterproof and they must stay away from water or mud,
unlike the Adelie chick shown on the left picture which died a
few minutes after falling in muddy water. Yes, it's a harsh
world and that's why Adelie penguins build nests out of
pebbles. Once a chick has feathered (or fledged), it enters
the sea and becomes independent of its parents.
Right: Adelie penguin swimming fast and jumping out of the
water.
How can I find a job that deals with penguins ?
You mean zookeeper ? Kid working in a south-east asian
sweatshop making stuffed teddy penguins ? Linux kernel
developer ? Hockey player in Pittsburgh ? OK, the proper
term would be ornithologist (bird scientist). Most
ornithologists are hobbyists, but you can get a PhD and
make a job off it. All the information you want (and more) is
in the Going To Antarctica page
.
Right: Krill, a little shrimp that is the main part of the diet of
penguins.
How do emperor penguins get their food ?
They swim fast and catch it in the sea: krill (picture on
right), shrimp, small fish, octopus... The Antarctic ocean is
very rich with life, more so than the equator for instance.
The reason is quite technical: cold water can absorb more
oxygen than warm water, it's a physical property. Similarly
cold water can absorb less salt then warm water. And the
ocean (at -1.8°C) is always warmer than the land. Those
two issues make it easier for life to thrive in cold oceans,
although the cold temperature slows down animal
metabolism (or requires insulation such as fat) and the lack
of sunlight in winter stops the photosynthesis of plankton.
Penguins are extremely good swimmers that can dive to
500m of depth and stay submerged for 5 minutes, but don't
forget that, like dolphins for instance, they need to go back
to the surface to breathe fresh air.
Do penguins make noise ?
Yes, and lots of it ! Pass your mouse over the first few
pictures above to hear them. They have a very loud voice
similar to a donkey braying. Those calls are essential since
they recognize themselves only through voice, not visually.
They call to attract mates, when doing courtship, when
greeting a returning mate, when threatening other penguins
(or a human coming too close), or sometimes when bored
alone. Different species of penguins have different calls, and
in some species like the Emperors the male and female have
a distinct voice that one can tell apart with a little training
(listen to the samples below).
On my first job in Antarctica, I installed a Sodar, an acoustic
device to do remote sensing of the lower atmosphere. In
summer the data was perturbed by the noise coming from
all the Adelie penguins.
Here are the recorded sounds I have (just click on
them):Adult Adelie (male or female)Adelie chickMale
EmperorFemale EmperorEmperor chick Now just try to
imagine when there are 5000 of them at the same time...
Right: A dead Adelie penguin on its way to becoming a fossile.
Do penguins have predators ?
Emperor penguins do not have predators, either in sea (they
are too fast) or on the land (no other animals in winter in
Antarctica). In spring Giant Petrels will occasionally grab an
abandoned chick, and also juveniles that haven't learnt to
swim well may fall prey to the Leopard Seal when first
hitting the water. Thus emperor penguins don't have any
defense mechanism, they only start to turn around and flee
if you get within one or two meters from them. Their main
enemy is the cold and the distance to the sea; and on really
cold winters some of them do not have the strength to make
it back to the sea.
Adult Adelie penguins do not have predators on land;
although their unatented eggs and chicks are often attacked
by skuas (which is probably the reason why most penguins
are afraid of what comes from the sky). When in the sea
they have to avoid Leopard Seal and killer whales.
How long do penguins live ?
So unlike many animals Antarctic penguins are lucky not to
have too many predators and it's possible for them to die of
old age. There's an Emperor at DdU who was tagged 40
years ago, still coming every year. Adelie penguins have a
life expectancy of 15 years or more.
Right: Adult adelie penguins aggressive towards a chick out of
his own nest.
Do penguins fight ? Are penguins aggressive ?
They have few predators, but Adelie penguins fight between
themselves a lot for various reasons: for mates, for the best
nest locations, for the possession of rocks and pebbles, if
some other penguin gets too close to their nest... Those
fights never go beyond the 'first blood' but I've seen
penguins jump off cliffs in fright (or being pushed off !).
Their defense mechanism involves loud braying calls,
threatening attitudes (body moving side to side), pinching
with the beak and hitting very fast with their flippers which
are very hard (it's just a flat bone with skin and thin feathers
on top). I was once standing in the middle of the base,
talking with a colleague, when a penguin in a bad mood
decided I was in his way. He bit me on the tendon inside the
knee while hitting me very hard with a series of lightning
fast punches ! I had a limp for a week.
Adult Adelies are particularly aggressive towards others'
chicks. Chicks can be abandonned for two reasons: either a
parent disapeared at sea and the other had to go feed, or
there were twins but the parents had only enough food to
feed one chick (the biggest). I which case you see a
wretched chick walking around the rookeries, getting weaker
by the day, trying to get back to his nest but constantly
harassed by the other adults, and soon watched very closely
by a skua or two...
On the other hand, Emperor penguins are probably the most
placid animals ever. No predators, so no defence
mechanism. And they need to rely a lot on the others to
survive the winter together, so the only time they display
any kind of aggressivity are when the females compete for a
male: they just stand around and try to interrupt him if he
chooses a mate by standing in the middle. That's about all.
Where are penguins located ?
Adelie and Emperor penguins live on the shores of
Antarctica, in the few places that have rocks for Adelie and
in the few places where the sea ice is stable enough not to
be broken up by strong winter storms for Emperors. Just
think that 98% of Antarctica is covered by ice, so that
doesn't leave much rock for Adelie penguins to settle. And
there are glaciers around most of Antarctica, making it too
unstable and dangerous for Emperors to settle (glaciers
move, they have crevasses, falling seracs...).
In the spring of '93 we had a record number of Emperor
penguin chicks next to Dumont d'Urville. Due to unusually
warm and mild weather they spread out on the ice quite far
way, leaving the sheltered area between the islands. Then a
strong storm came and broke up the ice around the islands.
After the end of the storm, two thirds of the chicks were
missing, fallen in the deadly cold water while still wearing
their down feathers...
Are penguins found only in Antarctica ?
No. Different species have different habitats: Adelie and
Emperors in Antarctica; King, Chinstrap and others in subAntarctic Islands (plenty of small islands that are located in
the Antarctic Ocean, the south Pacific, south Atlantic or
south Indian ocean); Little Blue, Yellow-eyed and others at
the southernmost tips of America, Africa or Australia; there
are even penguins near the equator, at the Galapagos
Islands.
But there aren't any penguins in the northern hemisphere,
although there used to be a very similar flightless bird of a
different family, called the great penguin aka Great Auk, a
cousin of puffins from the Arctic sea. Unfortunately it was
hunted to extinction in the 1600s. Penguins are very slow
and awkward on land, making them easy preys for
predators, that's why they are only common on small islands
or places that do (or did) not have any predators (including
humans).
Right: A creche of emperor penguin chicks in early spring.
What is called a group of penguins ?
I can think of no less than 4 different terms:
A 'rookery'. Emperor penguins huddle together to form one
very large rookery when it's cold and split in smaller groups
spread on the ice when it's warm; they don't make nests but
carry their eggs or their feet. Adelie penguins form small
rookeries of 2 to hundreds of couples by building nests on
rocky outcrops.
When emperors are huddled close together against the chilly
winter storms, we call this a 'turtle', just like the Roman
legionnaires defensive position. Penguins in this situation
change position periodically, those on the outside moving
back inside to shelter from the cold, something similar to
bikers taking the lead temporarily although it costs them
energy. This behavior was thought to be a fairly unique
altruistic behavior, but it can be explained quite simply by
evolutionary biology: no penguin want to be outside exposed
to the cold, so they try to get to the center, but they don't
want to fight for it (a big waste of energy), so they just push
slowly till they get a better position; and later other
penguins pushing in other directions will expose them again.
When they grow bigger and no longer need an adult at all
time to keep them sheltered, the chicks group together in
'crèches' (picture on left), a French word for crib. They do
this for protection against the cold and against predators
(Skuas and Giant petrels) but are not cared communally by
the remaining adults: adults will feed only their own chick
which they recognize by its voice. There can be several
crèches in a large rookery.
And more simply we also say that all the rookeries in a
common area form a 'colony'.
What other animals live near penguins ?
Seals, other birds like skuas and petrels, and even
sometimes humans in places like New Zealand or the
Galapagos.
Do penguins fall over when something fly over
them ?
No. This is an urban legend and I can't believe the NSF
actually founded a study on this. Adelie and Emperor
penguins are moderately scared of things from the sky
because that's where their only predators on land come from
(skuas and giant petrels that grab their unattended eggs or
chicks). They can also be afraid of noisy helicopters at first,
but they get used to them very fast. In Dumont d'Urville,
some Adelies are nesting less than 10 meters from
helicopter landing pads. They just crouch for a minute when
the chopper passes above them.
Right: Hole left by the body heat of an Adelie penguin who
waited out a storm for several days... with skidmarks !
What color is penguin poop ?
I can't believe some of the questions I get... Well, here
goes: it's kinda white with greenish and darkish streaks
when it comes out, but when it dries it turns to reddish for
Adelies and greenish for Emperors. The red comes from all
the krill that they eat and there are large quantities of this
red 'mud' accumulated around the rookeries (sometimes as
much as 10cm thick). The green is probably bile due to the
fact that the Emperors fast for a long period; the ice is
covered with it in spring and melts back into the sea.
The fact that adelie penguins nest on rock outcrops makes it
so that the higher ones 'shower' the lower ones. Just like in
our own society I guess...
Space Fuels (太空燃料)
We are gonna need : We are going to need : Are we gonna go soon?
fuel: (n) 1 a : a material used to produce heat or power by burning 燃料 b :
nutritive material c : a material from which atomic energy can be liberated
especially in a reactor 2 : a source of sustenance or incentive :
REINFORCEMENT 刺激物; 維持物 ; (vt) 1 : to provide with fuel 供以燃料
2 : SUPPORT, STIMULATE 支持; 刺激; (vi) to take in fuel -- often used
with up
colony (n) a : a body of people living in a new territory but retaining ties with
the parent state 殖民者 b : the territory inhabited by such a body 殖民地 2 : a
distinguishable localized population within a species 族群<colony of
termites> 3 a : a circumscribed mass of microorganisms usually growing in or
on a solid medium 『微生物』微生物的滋繁 b : the aggregation of zooids
of a compound animal 4 a : a group of individuals or things with common
characteristics or interests situated in close association <an artist colony> b :
the section occupied by such a group 5 : a group of persons institutionalized
away from others (被隔離安置於遠處的) 一群人 <a leper colony>安置在離
島的罪犯 <a penal colony>; also : the land or buildings occupied by such a
group (上述之) 隔離, 聚集區
Stop the presses : stop the reporting/printing/publishing activities.
press: (n) 7a : the gathering and publishing or broadcasting of news :
JOURNALISM b : newspapers, periodicals, and often radio and television
news broadcasting 新聞, 出版, 傳播 c : news reporters, publishers, and
broadcasters d : comment or notice in newspapers and periodicals <is getting
a good press>
comet (n) a celestial body that consists of a fuzzy head usually surrounding a
bright nucleus, that has a usually highly eccentric orbit, and that often when
in the part of its orbit near the sun develops a long tail which points away
from the sun『天文』彗星, 掃帚星
Fuel
fuel, material that can be burned or otherwise consumed to produce heat.
The common fuels used in industry, transportation, and the home are burned
in air. The carbon and hydrogen in fuel rapidly combine with oxygen in the
air in an exothermal reaction—one that liberates heat. Most of the fuels used
by industrialized nations are in the form of incompletely oxidized and
decayed animal and vegetable materials, or fossil fuels(化石燃料, 礦物燃料),
specifically coal(煤炭), peat(泥炭), lignite(褐炭), petroleum(石油), and
natural gas(天然瓦斯). From these natural fuels other artificial ones can be
derived. Coal gas, coke, water gas, and producer gas can be made using coal
as the principal ingredient. Gasoline, kerosene, and fuel oil are made from
petroleum. For most transportation, fuel must be in a liquid form.
[exothermal『物理』可散熱的; isothermal 同溫的; adiabatic『物理』絕
熱的
peat : partially carbonized vegetable tissue formed by partial
decomposition in water of various plants (as mosses『植物』苔, 蘚, 地衣
of the genus Sphagnum), i.e., soil material consisting of partially
decomposed organic matter; found in swamps 沼澤 and bogs 濕地 in
various parts of the temperate zone. It is formed by the slow decay of
successive layers of aquatic and semiaquatic plants, e.g., sedges, reeds,
rushes, and mosses. a bold lively woman
lignite (n) a usually brownish black coal intermediate between peat and
bituminous coal; especially : one in which the texture of the original wood
is distinct -- called also brown coal. It contains more moisture than coal
and tends to dry and crumble when exposed to the air; the flame is long
and smoky and the heating power low. It is found in the United States,
Canada, Germany, and elsewhere chiefly in formations formed in the
Tertiary period. { bituminous(adj) 1 : containing or impregnated with
bitumen 2 : of or relating to bituminous coal ; bitumen 瀝青, 黑褐色 (n) 1 :
an asphalt of Asia Minor used in ancient times as a cement and mortar 2 :
any of various mixtures of hydrocarbons (as tar) often together with their
nonmetallic derivatives that occur naturally or are obtained as residues
after heat-refining natural substances (as petroleum);
]
There is a growing concern about the environmental contamination caused by
the burning of great amounts of fossil fuels and about the increasing expense
of finding them and processing them into easily usable forms (see energy,
sources of). During the last 100 years the amount of carbon dioxide in the
atmosphere has increased, and there is evidence that this phenomenon may be
due to the burning of fossil fuel. Use of biomass, which consists of plants or
plant waste, would not produce excess carbon dioxide because the plants
absorb the gas for their growth. Wood is not as concentrated a form of energy
as fossil fuels, but it can be converted into a more energy-rich fuel called
charcoal. Burning fossil fuel also releases acidic oxides of sulfur and nitrogen
which are deposited on the earth in rainwater (see acid rain). The clearing of
forests, particularly in the tropical regions, also threatens to increase the
amount of carbon dioxide in the atmosphere because the forests utilize carbon
dioxide for growth.
[biomass (n) 1 : the amount of living matter (as in a unit area or volume of
habitat) 『生物』生物量 2 : plant materials and animal waste used especially
as a source of fuel]
The amount of fossil fuel available is limited and new methods of recovery
are being developed. One proposed alternative fuel is hydrogen, which is now
employed as a fuel only for a few special purposes because of its high cost.
Hydrogen can be produced by electrolysis of water for which nonfossil fuels
would supply the energy. Solar energy could be utilized either by direct
conversion to electricity using photovoltaic cells or by trapping solar heat.
Fuels are rated according to the amount of heat (in calories or Btu) they can
produce. Nuclear fuels are also possible substitutes for fossil fuels. Nuclear
fuels are not burned; they undergo reactions in which the nuclei of their atoms
either split apart, i.e., undergo fission, or combine with other nuclei, i.e.,
undergo fusion. In either case, a small part of the nuclear mass is converted to
heat energy. All nuclear fuels currently employed in practical, nonweapons
applications react by fission.
[electrolysis (n) the producing of chemical changes by passage of an electric
current through an electrolyte b : subjection to this action『化學』電解
photovoltaic (adj): 『電子』光電伏特的 of, relating to, or utilizing the
generation of a voltage when radiant energy falls on the boundary between
dissimilar substances (as two different semiconductors)]
High-energy fuels for jet engines and rockets are rated by their specific
impulse in thrust per pound of propellant per second. Hydrogen, which is the
lightest element, is usually used in the form of compounds, because the
density of liquid hydrogen is low and therefore a large volume is required.
Addition of aluminum 鋁 powder or lithium 鋰 increases the efficiency.
Rockets usually have a self-contained supply of oxygen or some other
oxidizer, such as ammonium 銨 (氨鹽基), lithium, or potassium perchlorate.
Fuels such as turpentine, alcohol, aniline, and ammonia use nitric acid,
hydrogen peroxide, and liquid oxygen as oxidizers. More power can be
obtained by oxidizing hydrazine, diborane, or hydrogen with oxygen, ozone,
or fluorine.
See oil gas; liquefied petroleum gas; gas, fuel; nuclear energy.
[perchlorate (n)] a salt or ester of perchloric acid『化學』高氯酸鹽
perchloric acid (n) a fuming corrosive strong acid HClO4 that is the most
highly oxidized acid of chlorine and a powerful oxidizing agent when heated
『化學』過氯酸
Fuel Cell 燃料電池
webster: a device that continuously changes the chemical energy of a
fuel (as hydrogen) and an oxidant directly into electrical energy
Fuel cell: electric cell in which the chemical energy from the oxidation of a
gas fuel is converted directly to electrical energy in a continuous process (see
oxidation and reduction). The efficiency of conversion from chemical to
electrical energy in a fuel cell is between 65% and 80%, nearly twice that of
the usual indirect method of conversion in which fuels are used to heat steam
to turn a turbine connected to an electric generator. The earliest fuel cell, in
which hydrogen and oxygen were combined to form water, was constructed
in 1829 by the Englishman William Grove. In the hydrogen and oxygen fuel
cell, hydrogen and oxygen gas are bubbled into separate compartments
connected by a porous disk through which an electrolyte such as aqueous 似
水 的 potassium hydroxide (KOH 氫 氧 化 鉀 ) can move. Inert graphite
electrodes, mixed with a catalyst such as platinum 白金, are dipped into each
compartment. When the two electrodes are connected by a wire, the
combination of electrodes, wire, and electrolyte form a complete circuit, and
an oxidation-reduction (氧化-還原) reaction takes place in the cell: hydrogen
gas is oxidized to form water at the anode, or hydrogen electrode; electrons
are liberated in this process and flow through the wire to the cathode, or
oxygen electrode; and at the cathode the electrons combine with the oxygen
gas and reduce it. The modern hydrogen-oxygen cell, operating at about
250°C and a pressure of 50 atmospheres, gives a maximum voltage of about 1
volt. Fuel cells have been used to generate electricity in space flights.
What Is A Fuel Cell?
In principle, a fuel cell operates like a battery. Unlike a battery, a fuel cell
does not run down or require recharging. It will produce energy in the form of
electricity and heat as long as fuel is supplied.
A fuel cell consists of two electrodes sandwiched around an electrolyte.
Oxygen passes over one electrode and hydrogen over the other, generating
electricity, water and heat.
Hydrogen fuel is fed into the "anode" (陽極,正極) of the fuel cell. Oxygen (or
air) enters the fuel cell through the cathode. Encouraged by a catalyst, the
hydrogen atom splits into a proton (『物理』質子) and an electron (電子),
which take different paths to the cathode. The proton passes through the
electrolyte. The electrons create a separate current that can be utilized before
they return to the cathode, to be reunited with the hydrogen and oxygen in a
molecule of water.
[neutron : 『物理』中子]
A fuel cell system which includes a "fuel reformer" can utilize the hydrogen
from any hydrocarbon(碳氫化合物)fuel - from natural gas to methanol, and
even gasoline. Since the fuel cell relies on chemistry and not combustion,
emissions from this type of a system would still be much smaller than
emissions from the cleanest fuel combustion processes.
[methanol = methyl alcohol 『化學』甲醇 = wood alcohol 木精: a light
volatile flammable poisonous liquid alcohol CH3OH used especially as a
solvent, antifreeze, or denaturant for ethyl alcohol and in the synthesis of other
chemicals [methyl:甲基 an alkyl group CH3 derived from methane by
removal of one hydrogen atom]
TYPES OF FUEL CELLS
Phosphoric Acid
Proton Exchange Membrane or Solid Polymer
Molten Carbonate
Solid Oxide
Alkaline
Direct Methanol Fuel Cells
Regenerative Fuel Cells
Zinc Air Fuel Cells
Protonic Ceramic Fuel Cell
-------------------------------------------------------------------------------Phosphoric Acid (PAFC). This type of fuel cell is commercially available
today. More than 200 fuel cell systems have been installed all over the world
- in hospitals, nursing homes, hotels, office buildings, schools, utility power
plants, an airport terminal, landfills and waste water treatment plants. PAFCs
generate electricity at more than 40% efficiency -- and nearly 85% of the
steam this fuel cell produces is used for cogeneration -- this compares to
about 35% for the utility power grid in the United States. Operating
temperatures are in the range of 300 to 400 degrees F (150 - 200 degrees C).
At lower temperatures, phosphoric acid is a poor ionic conductor, and carbon
monoxide (CO) poisoning of the Platinum (Pt) electro-catalyst in the anode
becomes severe. The electrolyte is liquid phosphoric acid soaked in a matrix.
One of the main advantages to this type of fuel cell, besides the nearly 85%
cogeneration efficiency, is that it can use impure hydrogen as fuel. PAFCs
can tolerate a CO concentration of about 1.5 percent, which broadens the
choice of fuels they can use. If gasoline is used, the sulfur must be removed.
Disadvantages of PAFCs include: it uses expensive platinum as a catalyst, it
generates low current and power comparably to other types of fuel cells, and
it generally has a large size and weight. PAFCs, however, are the most mature
fuel cell technology. Through organizational linkages with Gas Research
Institute (GRI), electronic utilities, energy service companies, and user groups,
the Department of Energy (DOE) helped in bringing about the
commercialization of a PAFC, produced by ONSI (now UTC Fuel Cells).
Existing PAFCs have outputs up to 200 kW, and 1 MW units have been
tested.
Anode: H2(g) -> 2H+(aq)+ 2eCathode: ½O2(g) + 2H+(aq) + 2e- -> H2O(l)
-------------------------------------------------------------------------------Cell: H2(g) + ½O2(g)+ CO2 -> H2O(l) + CO2
Proton Exchange Membrane (PEM). These cells operate at relatively low
temperatures (about 175 degrees F or 80 degrees C), have high power density,
can vary their output quickly to meet shifts in power demand, and are suited
for applications, -- such as in automobiles -- where quick startup is required.
According to DOE, "they are the primary candidates for light-duty vehicles,
for buildings, and potentially for much smaller applications such as
replacements for rechargeable batteries." The proton exchange membrane is a
thin plastic sheet that allows hydrogen ions to pass through it. The membrane
is coated on both sides with highly dispersed metal alloy particles (mostly
platinum) that are active catalysts. The electrolyte used is a solid organic
polymer poly-perflourosulfonic acid. The solid electrolyte is an advantage
because it reduces corrosion and management problems. Hydrogen is fed to
the anode side of the fuel cell where the catalyst encourages the hydrogen
atoms to release electrons and become hydrogen ions (protons). The electrons
travel in the form of an electric current that can be utilized before it returns to
the cathode side of the fuel cell where oxygen has been fed. At the same time,
the protons diffuse through the membrane (electrolyte) to the cathode, where
the hydrogen atom is recombined and reacted with oxygen to produce water,
thus completing the overall process. This type of fuel cell is, however,
sensitive to fuel impurities. Cell outputs generally range from 50 to 250 kW.
Anode: H2(g) -> 2H+(aq) + 2eCathode: ½O2(g) + 2H+(aq) + 2e- -> H2O(l)
-------------------------------------------------------------------------------Cell: H2(g) + ½O2(g) -> H2O(l)
Molten Carbonate (MCFC). These fuel cells use a liquid solution of lithium,
sodium and/or potassium carbonates, soaked in a matrix for an electrolyte.
They promise high fuel-to-electricity efficiencies, about 60% normally or
85% with cogeneration, and operate at about 1,200 degrees F or 650 degrees
C. The high operating temperature is needed to achieve sufficient
conductivity of the electrolyte. Because of this high temperature, noble metal
catalysts are not required for the cell's electrochemical oxidation and
reduction processes. To date, MCFCs have been operated on hydrogen,
carbon monoxide, natural gas, propane, landfill gas, marine diesel, and
simulated coal gasification products. 10 kW to 2 MW MCFCs have been
tested on a variety of fuels and are primarily targeted to electric utility
applications. Carbonate fuel cells for stationary applications have been
successfully demonstrated in Japan and Italy. The high operating temperature
serves as a big advantage because this implies higher efficiency and the
flexibility to use more types of fuels and inexpensive catalysts as the
reactions involving breaking of carbon bonds in larger hydrocarbon fuels
occur much faster as the temperature is increased. A disadvantage to this,
however, is that high temperatures enhance corrosion and the breakdown of
cell components.
Anode: H2(g) + CO32- -> H2O(g) + CO2(g) + 2eCathode: ½O2(g) + CO2(g) + 2e- -> CO32-
-------------------------------------------------------------------------------Cell: H2(g) + ½O2(g) + CO2(g) -> H2O(g) + CO2(g)
Solid Oxide (SOFC). Another highly promising fuel cell, this type could be
used in big, high-power applications including industrial and large-scale
central electricity generating stations. Some developers also see SOFC use in
motor vehicles and are developing fuel cell auxiliary power units (APUs)
with SOFCs. A solid oxide system usually uses a hard ceramic material of
solid zirconium oxide and a small amount of ytrria, instead of a liquid
electrolyte, allowing operating temperatures to reach 1,800 degrees F or 1000
degrees C. Power generating efficiencies could reach 60% and 85% with
cogeneration and cell output is up to 100 kW. One type of SOFC uses an
array of meter-long tubes, and other variations include a compressed disc that
resembles the top of a soup can. Tubular SOFC designs are closer to
commercialization and are being produced by several companies around the
world. Demonstrations of tubular SOFC technology have produced as much
as 220 kW. Japan has two 25 kW units online and a 100 kW plant being
testing in Europe.
Anode: H2(g) + O2- -> H2O(g) + 2eCathode: ½O2(g) + 2e- -> O2-
-------------------------------------------------------------------------------Cell: H2(g) + ½O2(g) -> H2O(g)
Alkaline. Long used by NASA on space missions, these cells can achieve
power generating efficiencies of up to 70 percent. They were used on the
Apollo spacecraft to provide both electricity and drinking water. Their
operating temperature is 150 to 200 degrees C (about 300 to 400 degrees F).
They use an aqueous solution of alkaline potassium hydroxide soaked in a
matrix as the electrolyte. This is advantageous because the cathode reaction is
faster in the alkaline electrolyte, which means higher performance. Until
recently they were too costly for commercial applications, but several
companies are examining ways to reduce costs and improve operating
flexibility. They typically have a cell output from 300 watts to 5 kW.
Anode: H2(g) + 2(OH)-(aq) -> 2H2O(l) + 2eCathode: ½O2(g) + H2O(l) + 2e- -> 2(OH)-(aq)
-------------------------------------------------------------------------------Cell: H2(g) + ½O2(g) -> H2O(l)
Direct Methanol Fuel Cells (DMFC). These cells are similar to the PEM cells
in that they both use a polymer membrane as the electrolyte. However, in the
DMFC, the anode catalyst itself draws the hydrogen from the liquid methanol,
eliminating the need for a fuel reformer. Efficiencies of about 40% are
expected with this type of fuel cell, which would typically operate at a
temperature between 120-190 degrees F or 50 -100 degrees C. This is a
relatively low range, making this fuel cell attractive for tiny to mid-sized
applications, to power cellular phones and laptops. Higher efficiencies are
achieved at higher temperatures. A major problem, however, is fuel crossing
over from the anode to the cathode without producing electricity. Many
companies have said they solved this problem, however. They are working on
DMFC prototypes used by the military for powering electronic equipment in
the field.
Anode: CH3OH(aq) + H2O(l) -> CO2(g) + 6H+(aq) + 6eCathode: 6H+(aq) + 6e- + 3/2O2(g) -> 3H2O(l)
-------------------------------------------------------------------------------Cell: CH3OH(aq) + 3/2O2(g) -> CO2(g) + 2H2O(l)
Regenerative Fuel Cells. Still a very young member of the fuel cell family,
regenerative fuel cells would be attractive as a closed-loop form of power
generation. Water is separated into hydrogen and oxygen by a solar-powered
electrolyser. The hydrogen and oxygen are fed into the fuel cell which
generates electricity, heat and water. The water is then recirculated back to
the solar-powered electrolyser and the process begins again. These types of
fuel cells are currently being researched by NASA and others worldwide.
Zinc-Air Fuel Cells (ZAFC). In a typical zinc/air fuel cell, there is a gas
diffusion electrode (GDE), a zinc anode separated by electrolyte, and some
form of mechanical separators. The GDE is a permeable membrane that
allows atmospheric oxygen to pass through. After the oxygen has converted
into hydroxyl ions and water, the hydroxyl ions will travel through an
electrolyte, and reaches the zinc anode. Here, it reacts with the zinc, and
forms zinc oxide. This process creates an electrical potential; when a set of
ZAFC cells are connected, the combined electrical potential of these cells can
be used as a source of electric power. This electrochemical process is very
similar to that of a PEM fuel cell, but the refueling is very different and
shares characteristics with batteries. Metallic Power is working on ZAFCs
containing a zinc "fuel tank" and a zinc refrigerator that automatically and
silently regenerates the fuel. In this closed-loop system, electricity is created
as zinc and oxygen are mixed in the presence of an electrolyte (like a
PEMFC), creating zinc oxide. Once fuel is used up, the system is connected
to the grid and the process is reversed, leaving once again pure zinc fuel
pellets. The key is that this reversing process takes only about 5 minutes to
complete, so the battery recharging time hang up is not an issue. The chief
advantage zinc-air technology has over other battery technologies is its high
specific energy, which is a key factor that determines the running duration of
a battery relative to its weight. When ZAFCs are used to power EVs, they
have proven to deliver longer driving distances between refuels than any
other EV batteries of similar weight. Moreover, due to the abundance of zinc
on earth, the material costs for ZAFCs and zinc-air batteries are low. Hence,
zinc-air technology has a potential wide range of applications, ranging from
EVs, consumer electronics to military. Powerzinc in southern California is
currently commercializing their zinc/air technology for a number of different
applications.
Protonic Ceramic Fuel Cell (PCFC). This new type of fuel cell is based on
a ceramic electrolyte material that exhibits high protonic conductivity at
elevated temperatures. PCFCs share the thermal and kinetic advantages of
high temperature operation at 700 degrees Celsius with molten carbonate and
solid oxide fuel cells, while exhibiting all of the intrinsic benefits of proton
conduction in polymer electrolyte and phosphoric acid fuel cells (PAFCs).
The high operating temperature is necessary to achieve very high electrical
fuel efficiency with hydrocarbon fuels. PCFCs can operate at high
temperatures and electrochemically oxidize fossil fuels directly to the anode.
This eliminates the intermediate step of producing hydrogen through the
costly reforming process. Gaseous molecules of the hydrocarbon fuel are
absorbed on the surface of the anode in the presence of water vapor, and
hydrogen atoms are efficiently stripped off to be absorbed into the electrolyte,
with carbon dioxide as the primary reaction product. Additionally, PCFCs
have a solid electrolyte so the membrane cannot dry out as with PEM fuel
cells, or liquid can't leak out as with PAFCs. Protonetics International Inc. is
primarily researching this type of fuel cell.
Applications for Fuel Cells
Stationary
Residential
Transportation
Portable Power
Landfill/Wastewater Treatment
-------------------------------------------------------------------------------There are many uses for fuel cells — right now, all of the major automakers
are working to commercialize a fuel cell car. Fuel cells are powering buses,
boats, trains, planes, scooters, even bicycles. There are fuel cell-powered
vending machines, vacuum cleaners and highway road signs. Miniature fuel
cells for cellular phones, laptop computers and portable electronics are on
their way to market. Hospitals, credit card centers, police stations, and banks
are all using fuel cells to provide power to their facilities. Wastewater
treatment plants and landfills are using fuel cells to convert the methane gas
they produce into electricity. The possibilities are endless. For monthly
updates on the latest fuel cell developments in all applications, sign-up for our
listserve to receive Fuel Cells 2000's monthly technology updates via email.
Send a BLANK email (no subject) here to subscribe.
Stationary. More than 200 fuel cell systems have been installed all over the
world — in hospitals, nursing homes, hotels, office buildings, schools, utility
power plants, and an airport terminal, providing primary power or backup. In
large-scale building systems, fuel cells can reduce facility energy service
costs by 20% to 40% over conventional energy service.
Residential. Fuel cells are ideal for power generation, either connected to the
electric grid to provide supplemental power and backup assurance for critical
areas, or installed as a grid-independent generator for on-site service in areas
that are inaccessible by power lines. Since fuel cells operate silently, they
reduce noise pollution as well as air pollution and the waste heat from a fuel
cell can be used to provide hot water or space heating for a home. Many of
the prototypes being tested and demonstrated for residential use extract
hydrogen from propane or natural gas. See our FAQ's section for more
information.
Transportation. All the major automotive manufacturers have a fuel cell
vehicle either in development or in testing right now — Honda, Toyota,
DaimlerChrysler, GM, Ford, Hyundai, Volkswagen — you name it. They
speculate that the fuel cell vehicle will not be commercialized until at least
2004. For more information on fuel cells in transportation, check out our
Transportation Mini-Site.
Portable Power. Miniature fuel cells, once available to the commercial
market, will help consumers talk for up to a month on a cellular phone
without recharging. Fuel cells will change the telecommuting world,
powering laptops and palm pilots hours longer than batteries. Other
applications for micro fuel cells include pagers, video recorders, portable
power tools, and low power remote devices such as hearing aids, smoke
detectors, burglar alarms, hotel locks and meter readers. These miniature fuel
cells generally run on methanol, an inexpensive wood alcohol also used in
windshield wiper fluid.
natural gas
natural gas,
natural mixture of gaseous hydrocarbons found issuing from the
ground or obtained from specially driven wells. The composition of natural
gas varies in different localities. Its chief component, methane 化學』甲烷,
usually makes up from 80% to 95%, and the balance is composed of varying
amounts of ethane 乙烷, propane 丙烷, butane 丁烷, and other hydrocarbon
compounds. Because of its flammability and high calorific value, natural gas is
used extensively as an illuminant and a fuel. Although commonly associated
with petroleum deposits it also occurs separately in sand, sandstone, and
limestone deposits. Some geologists theorize that natural gas is a byproduct of
decaying vegetable matter in underground strata, while others think it may be
primordial gases that rise up from the mantle. Some of the hydrocarbons found
in gasoline also occur as vapors in natural gas; by liquefying these
hydrocarbons, gasoline can be obtained. Natural gas was known to the ancients
but was considered by them to be a supernatural phenomenon because, noticed
only when ignited, it appeared as a mysterious fire bursting from the ground.
One of the earliest attempts to harness it for economic use occurred in the
early 19th cent. in Fredonia, N.Y. Toward the latter part of the 19th cent., large
industrial cities began to make use of natural gas, and extensive pipeline
systems have been constructed to transport gas. Liquefied natural gas,. or
LNG, is natural gas that has been pressurized and cooled so as to liquefy it for
convenience in shipping and storage. The boiling point of natural gas is
extremely low, and only in the 1970s did cryogenic technology (see lowtemperature physics) advance enough to make the production and transport of
LNG commerically feasible. Some of the natural gas moved to and from the
United States is carried as LNG in special tankers.
liquefied petroleum gas
liquefied petroleum gas
or LPG,mixture of gases, chiefly propane and
butane, produced commercially from petroleum and stored under pressure to
keep it in a liquid state. The boiling point of liquefied petroleum gas varies
from about -44°C to 0°C (-47°F to 32°F), so that the pressure required to
liquefy it is considerable and the containers for it must be of heavy steel. When
prepared as fuel, LPG is largely propane; common uses are for powering
automotive vehicles, for cooking and heating, and sometimes for lighting in
rural areas. LPG is an attractive fuel for internal-combustion engines; because
it burns with little air pollution and little solid residue, it does not dilute
lubricants, and it has a high octane rating.
Hydrocarbon
hydrocarbon
, any organic compound composed solely of the elements
hydrogen and carbon. The hydrocarbons differ both in the total number of
carbon and hydrogen atoms in their molecules and in the proportion of
hydrogen to carbon. The hydrocarbons can be divided into various
homologous series. Each member of such a series shows a definite relationship
in its structural formula to the members preceding and following it, and there
is generally some regularity in changes in physical properties of successive
members of a series. The alkanes are a homologous series of saturated
aliphatic hydrocarbons. The first and simplest member of this series is
methane, CH4; the series is sometimes called the methane series. Each
successive member of a homologous series of hydrocarbons has one more
carbon and two more hydrogen atoms in its molecule than the preceding
member. The second alkane is ethane, C2H6, and the third is propane, C3H8.
Alkanes have the general formula CnH2n+2 (where n is an integer greater than
or equal to 1). Generally, hydrocarbons of low molecular weight, e.g.,
methane, ethane, and propane, are gases; those of intermediate molecular
weight, e.g., hexane, heptane, and octane, are liquids; and those of high
molecular weight, e.g., eicosane (C20H42) and polyethylene, are solids. Paraffin
is a mixture of high-molecular-weight alkanes; the alkanes are sometimes
called the paraffin series. Other homologous series of hydrocarbons include
the alkenes and the alkynes. The various alkyl derivatives of benzene are
sometimes referred to as the benzene series. Many common natural
substances, e.g., natural gas, petroleum, and asphalt, are complex mixtures of
hydrocarbons. The coal tar obtained from coal by coking is also a mixture of
hydrocarbons. Natural gas, petroleum, and coal tar are important sources of
many hydrocarbons. These complex mixtures can be refined into simpler
mixtures or pure substances by fractional distillation.
Alkane
alkane ,
any of a group of aliphatic hydrocarbons whose molecules contain
only single bonds (see chemical bond). Alkanes have the general chemical
formula CnH2n+2. An alkane is said to have a continuous chain if each carbon
atom in its molecule is joined to at most two other carbon atoms; it is said to
have a branched chain if any of its carbon atoms is joined to more than two
other carbon atoms. The first four continuous-chain alkanes are methane, CH4;
ethane, C2H6; propane, C3H8; and butane, C4H10. Names of continuous-chain
alkanes whose molecules contain more than five carbon atoms are formed
from a root that indicates the number of carbon atoms and the suffix -ane to
indicate that the compound is an alkane; e.g., alkanes with 5, 6, 7, 8, 9, and 10
carbon atoms in their molecules are pentane, hexane, heptane, octane, nonane,
and decane, respectively. The name of a branched-chain alkane is formed by
adding prefixes to the name of the continuous-chain alkane from which it is
considered to be derived; e.g., 2-methylpropane (called also isobutane) is
thought of as being derived by replacing one of the hydrogen atoms bonded to
the second (2-) carbon atom of a propane molecule with a methyl (CH3) group,
forming CH3CH(CH3)2. Chemically, the alkanes are relatively unreactive.
They are obtained by fractional distillation from petroleum and are used
extensively as fuels. The alkanes are sometimes referred to as the methane
series (after the simplest alkane) or as paraffins.
Jellyfish (水母)
Raindrops(雨滴)
Birth of an Ocean (海洋的誕生)