Download Hydrosphere - Greenon Local Schools

Introduction to the Hydrosphere
Objective
• Students will understand the
components of the hydrosphere.
• Students will know the composition
of ocean water, the physical
structure of the ocean, and how the
ocean is important to humanity.
Review: The Hydrosphere I
• Hydrosphere: the combined mass of
water found on, under, and over the
surface of the Earth
• Recall that the hydrosphere is
connected to the other spheres of
the Earth System
• Can anybody come up with one way
that the hydrosphere is connected
to another sphere?
Review: The Hydrosphere II
• The Water Cycle describes how the
hydrosphere is connected to the
atmosphere, cryosphere, biosphere
and lithosphere
The World’s Water I
• Most of the world’s water is in the
ocean basins (97%)
• A much smaller
amount (3%) is
freshwater
• Only 1% of the
freshwater is
easily accessible
The World’s Water II
The Importance of Water I
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Water is a necessity for life on Earth
(1) Organisms need it to live
(2) Growing food
(3) Transportation
(4) Industry
(5) Other uses
Water is important to industry
The Importance of Water II
• Water use varies from country to
country, poorer countries use water
more for agriculture, and richer
countries use water more for industry
The Importance of Water III
• The world's six billion people are already
appropriating 54 per cent of all the
accessible freshwater contained in
rivers, lakes and underground aquifers.
• By 2025 humankind's share will be 70
per cent
• As the world continues to industrialize,
water demand will likely increase
The Importance of Water IV
• Conflicts and wars have been fought over
water rights
• Middle East fighting over the rights to the
Jordan River water
• Water wars over Los Angeles water access
in California
• "If the wars of this century were fought
over oil, the wars of the next century will
be fought over water.“ - World Bank vice
president
(Ismail Serageldin), 1995
The Importance of Water V
• Nonrenewable resources—Can’t be
replaced in nature very quickly
Vs.
• Renewable resources—Can be
replaced in nature very quickly, once
you use up the resource, it’s gone
• Do you think water is a renewable or
nonrenewable resource? Explain
Ocean Water I
• Ocean water is commonly called
“sea water”
• Composed of the following:
• (1) Dissolved gases (including
oxygen and carbon dioxide)
• (2) Dissolved nutrients (nitrates and
phosphates)
• (3) Dissolved solids (salts)
• (4) Suspended solids
Ocean Water II
• Salinity: The measure of the amount of
dissolved salts in seawater.
• Salinity is usually measured in parts per
thousand (ppt), 1 ppt is 0.1%
• The salinity of seawater varies:
• Where is the salinity
the greatest? The
least? Why?
Ocean Water III
• Density of freshwater = 1.0 g/cm3
• Density of saltwater = 1.02 g/cm3-1.03
g/cm3
• Which type of water sinks?
• Freshwater / Saltwater Demonstration
Ocean Water IV
• Ocean water absorbs light, this heats up
ocean water. However, some light is
reflected.
• Why does ocean water appear blue?
• Blue wavelengths are absorbed the least by
the deep ocean water and are scattered
and reflected back to the observer’s eye
• Why does ocean water appear black?
• All light is absorbed by the water and little
is reflected back.
• Why does ocean water appear green?
• Living organisms reflect green light
Ocean Water V
• The temperature of the ocean water
decreases with depth, in the area called
the thermocline (see the diagram)
• There are a
number of
environments that
are depth /
temperature
Three major layers:
(1) Epipleagic zone
dependent. We will
(2) Thermocline zone
(3) Bottom zone
discuss these later.
Ocean Water VI
•
Scientists have divided the ocean into five main layers. These layers, known as "zones", extend
from the surface to the most extreme depths where light can no longer penetrate. These deep
zones are where some of the most bizarre and fascinating creatures in the sea can be found. As
we dive deeper into these largely unexplored places, the temperature drops and the pressure
increases at an astounding rate. The following diagram lists each of these zones in order of
depth.
Fundamentals of Oceanography IA
• Ocean: Large body of salt water
• Five principle oceans in the world
• These oceans cover over 70% of the
surface of the Earth
Fundamentals of Oceanography IB
• Some oceans are broken into
southern / northern parts
• Seas: Large body of water marked off
by land boundaries
• Examples:
• North Sea
• Weddell Sea
• Ross Sea
• Caribbean Sea
Fundamentals of Oceanography II
• What is oceanography? Oceanography is the
study of the great bodies of salt water comprising
all the oceans and seas that cover nearly threefourths of the surface of the earth, and the
scientific study of the physical, chemical, and
biological aspects of the so-called world ocean.
The major goals of oceanography are to understand
the geologic and geochemical processes involved
in the evolution and alteration of the ocean and its
basin, to evaluate the interaction of the ocean and
the atmosphere so that greater knowledge of
climatic variations can be attained, and to describe
how the biological productivity in the sea is
controlled.
Fundamentals of Oceanography III
• The ocean floor isn’t flat, there is
underwater topography (called
bathymetry)
• Tectonics
• Mid ocean
ridge system
• Sea mounts
• Black smokers
• White smokers
• Fault zones
• Trenches
Fundamentals of Oceanography IVA
• Mid ocean ridge extends for over
49,000 miles, a place where new
ocean crust is forming
Fundamentals of Oceanography IVB
• The mid ocean ridge system is essentially a
long chain of volcanoes, a place where magma
comes to the bottom of the ocean floor
• The ocean floor spreads apart away from the
ridges
Fundamentals of Oceanography V
• Seamount: A mountain rising from the ocean
seafloor that does not reach to the water's surface,
and thus is not an island, extinct volcano
• Can provide habitats for marine species that are
not found on or around the surrounding deeper
ocean bottom
• Navigation hazards and good fishing
Fundamentals of Oceanography VIA
• Hot spot—A location on the Earth's
surface that has experienced active
volcanism for a long period of time
• Hot spots are visible in ocean basins as
a series of islands / seamounts (Hawaii)
Fundamentals of Oceanography VIB
• Hawaiian-Emperor Seamount
Chain, which is a whole series of
islands / seamounts formed from
the Hawaii hot spot:
Fundamentals of Oceanography VII
• Black smokers: A type of hydrothermal
vent found on the ocean floor
• Unique ecosystems near both
types of vents
• Organisms around these vents don’t
require sunlight to live, but chemicals
- Possible extractable ore deposits
• White smokers: White smokers are a type
of hydrothermal vent that emits lighterhued minerals than
black smokers. They are
generally cooler too.
Fundamentals of Oceanography VIIIA
• Faults, which are zones where rocks are
displaced (moved), can occur underwater,
below oceans and/or seas
• Tsunami: Is a series of waves created
when a body of water, such as an ocean, is
rapidly displaced
• Causes of tsunamis: (1) Displacement
along a fault, (2) Underwater volcanic
eruption, (3) Underwater avalanche, (4)
Impact of an extraterrestrial body
• DID YOU KNOW? The largest tsunami recorded
measured 210 feet, about 18 stories above sea level,
when it reached Siberia's Kamchatka Peninsula in 1737.
Fundamentals of Oceanography VIIIB
• A tsunami struck multiple countries
in Africa and Asia in 2004 due to an
underwater earthquake
• Seawalls are built to protect coastal
cities from
tsunamis
• Tsunami warning
network
Watch tsunami
videos
Fundamentals of Oceanography IXA
• Trench: A relatively deep, linear
and narrow oceanic feature that is
formed by plate subduction.
• Deepest parts of the ocean floors
• The deepest trench: Mariana
Trench (10,739 m (35,787 ft))
• Chemosynthetic (turning chemicals
into carbon) communities thrive in
certain deep trenches areas
Fundamentals of Oceanography IXB
•
The Puerto Rico Trench between the North American and Caribbean
Plates:
Ocean Currents I
The major surface currents in the world’s oceans are caused by prevailing winds. The
currents may be cold, as in the instance of the West Wind Drift, or warm, as the Gulf
Stream. Currents circulate in paths called gyres, moving in a clockwise direction in
the northern hemisphere and a counterclockwise direction in the southern
hemisphere.
Ocean Currents II
• Density Current: Different densities
caused by a difference in
temperature and salinity.
• Surface Current: Can move as fast
as 100 km a day and effect the top
200 m of the ocean. Driven by
winds.
Ocean Currents III
• Upwelling: The upward motion of ocean
water. Cold water moves from the bottom to
the surface. These waters are rich in
nutrients and very productive for fisherman.
High in oxygen.
• Upwelling = good fishin’! 
Ocean Currents IV
•
Life in the oceans is not uniformly abundant. Because of the low
ratio of surface water to deep water and the lack of seasonal
nutrient enrichment, much of the open ocean is a watery desert,
especially the tropical seas. The most productive areas are the
coastal regions, areas of upwellings (see below), and the Arctic and
Antarctic oceans
•
The rich Antarctic waters are pulled away from the shore and
become part of the Antarctic Circumpolar Current, also known as
West Wind Drift. This current, the strongest ocean current on earth,
is partially diverted by the southern tip of South America, forming
the Humboldt Current off the coast of Peru. As the surface water is
pulled out by winds, the nutrient-rich deep water replaces it, aided
by the absence of a continental shelf. This is an important upwelling
region, and it supports an enormous amount of life. Copepods and
opossum shrimp replace the krill of the Antarctic. Feeding on these
crustaceans are immense schools of small fish that, in turn, are
consumed by seabirds, replacing whales at the top of the food web.
Ocean Currents V
• The flow of ocean currents plays a
dominant part in the climate of
many of the Earth’s regions
• The world’s oceans collect heat and
transport it around the world
Ocean Resources IA
• Fishing is very important in provide world
societies with protein
• World total of 86 million tons of fish were
captured in 2000
• It will be necessary to manage ocean
fisheries in the coming years to make
sure the number of fish caught never
makes it to zero
• Predictions are that the sea can yield
only about 25 percent more than the
present amount of organic food
resources.
Ocean Resources IB
• Fisheries: is the name of the business of
harvesting fish and other marine animals and
plants in order to make a living. Fisheries include:
(1) large industrial-scale operations with foreign
fishermen who process their catch for export and
commercial sales, (2) small-scale operations by
local fishermen who primarily supply nearby
markets, (3) aquaculture farms which raise marine
animals and fish in a maintained environment, and
(4) businesses that produce fish products.
• Exclusive Economic Zone (EEZ): More than 90% of
world marine fish catch comes from the 10% of the
oceans closest to land. This area is included in the
Exclusive Economic Zone (EEZ). The EEZ refers to
the coastal waters that lie adjacent to the coast
and extend 200 nautical miles offshore.
Ocean Resources IC
• Countries have
exclusive rights within
the EEZ
Ocean Resources IIA
• Petroleum resources can be found
off of shorelines in oceans and/or
seas
• There are rock
layers under sea/
ocean water that
hold petroleum
and trap it
Simplified cross-section showing a slice through
the geologic layers under the Gulf of Mexico
Ocean Resources IIAA
• Oil platforms are situated in waters
off of coastlines, including in the Gulf
of Mexico
• These platforms are shut down when
hurricanes approach
17 percent of the world petroleum
production
Ocean Resources III
• The ocean is used for shipping
products from one country to
another
• Large number of products traveling
from China to the USA
• Panama Canal expansion
Ships can spill oil (or other chemicals) or can create noise
pollution, adversely affecting the marine environment
Ocean Resources IV
• Tourism is also an important
industry in the oceans
• Eco-tourism
Ocean Resources V
• Tidal energy farms
• A lot of wind energy can be
harnessed by placing windmills out in
seas and/or oceans. This is
commonly called “offshore wind”
Ocean Resources VI
• Desalinization plants: Plants that
remove excess salt and other
minerals from water
• Desalinization of ocean water is very
important in the dry Middle East, and
may be increasingly more important
in the future, worldwide
Ocean Resources VII
• Mining operations are conducted in
and under the ocean
• Diamonds, gold, silver, metal ores,
sand, salt, and gravel mines
Climate Change & the Oceans
Fun Fact
• Did you know? If all the gold
suspended in the world's seawater
were mined, each person on Earth
could have about 9 pounds of gold.
References
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http://www.unesco.org/water
http://www.worldwater.org
http://www.loc.gov
http://www.dictionary.com
http://oceanexplorer.noaa.gov
http://www.wikipedia.org
http://marinebio.org
http://www.mvtimes.com
http://www.aip.org
The Little Giant Book of Science Trivia