Download Great Idea: All matter above and beneath Earth`s surface moves in

Earth….a mostly closed system?
Great Idea:
All matter above and beneath Earth s surface moves in
cycles.
Can a planet like Earth be considered a
single living organism?
Can a planet like Earth be considered a single living
organism?
After all, the human body is composed of hundreds of billions of bacteria, and yet
we consider the human body to be a single organism. The Gaia Hypothesis (or
popularly known as “Gaia Theory”) goes beyond the individual organisms living on
Earth, it encompasses all the living and non-living components of Earth’s biosphere
and proposes that the complex interacting systems regulate the environment to a
very high degree.
When you stop to think about it, our planet does act like a huge organism. If you
look at the interrelationship between plants and atmospherics, animals and humans,
rocks and water, a complex pattern of symbiotic processes seem to complement
each other perfectly. Should one system be pushed out of balance by some external
force (such as a massive injection of atmospheric carbon dioxide after a volcanic
event), other processes are stimulated to counteract the instability (more
phytoplankton appear in the oceans to absorb the carbon dioxide in the water). Many
of these processes could be interpreted as a “global immune system”.
The biosphere is the net sum of all of the
ecosystems on Earth. It is often referred to
as the Earth’s life zone. In the most broad
sense of the word, in biophysiology, biosphere
is the global ecological system integrating all
living beings and their relationships, including
their interaction with the elements of the
lithosphere, hydrosphere, and the atmosphere.
It is thought that the biosphere has evolved through a process known as
biogenesis, which began more than 3.5 billion years ago. The term was
coined in 1875 by Eduard Suess. He defined it as the place on Earth where
life dwells.
There is a theory that the biosphere itself is a
living organism. This is called the Gaia hypothesis.
An atmospheric scientist from the United Kingdom,
James Lovelock, proposed the Gaia hypothesis to
explain how biotic and abiotic factors interact in
the biosphere. The theory postulates that the
atmosphere, geosphere, and hydrosphere are
cooperating systems that yield a biosphere full of
life.
Chapter Outline • 
• 
• 
• 
Cycles Small and Large The Hydrologic Cycle The Atmospheric Cycle The Rock Cycle Cycles Small and Large Recycling •  Where did the aluminum can go? •  Atoms last virtually forever –  Different forms •  Lava flow bonded to oxygen •  Solid rock •  Soil •  Aluminum metal •  Recycling saves energy Recycling Aluminum Cans The Nature of Earth s Cycle •  Earth materials move in cycles •  A change in one cycle affects the others •  Atoms constantly moving and recycling – 
– 
– 
– 
Reservoirs Hydrologic cycle Atmospheric cycle Rock cycle •  Heat –  Hotàcold –  Sources •  Sun •  Geothermal processes The Hydrologic Cycle Reservoirs of Water •  Amount of water on earth is fixed •  Major repositories –  Ice caps –  Glaciers •  Unseen reservoirs –  Groundwater •  Aquifers Major Repositories of Water Movements of Water between Reservoirs •  Hydrologic cycle –  Short-­‐term transfer of water between ocean and land Glaciers and Ice Caps Store Water The Hydrologic Cycle Ocean Currents •  Redistribute heat across planet The Science of Life •  Sobering facts about Earth s water –  96% is salty –  Less than 1% is readily available for human use Chemical Cycles in the Oceans •  Chemicals in constant moTon •  SalTness –  Constant over several hundred million years –  Primarily determined by Na+ and Cl-­‐ ions –  Residence Tme •  Chemical cycle Residence Times for Elements in the Ocean The Science of LIfe •  Element residence Tmes –  Human body Science by the Numbers •  The ocean s gold –  How much is present? Ice Ages •  Ice Age –  Water locked in glaciers –  Glaciers advance from poles •  Current ice age –  Interglacial period •  Earth s total water is fixed –  Ice caps, glaciers grow –  Sea level drops North American GlaciaTon RelaTonship of the Earth s Tilt to the Seasons Precession of the Earth s Axis Jet Stream Weather – cont. –  Humidity •  Atmospheric water content –  Cloudiness •  ConcentraTon of water droplets –  Prevailing winds •  Consequence of atmospheric convecTon Clouds and Rain; Windward Side of Mountains The General CirculaTon of the Atmosphere •  CirculaTon powered by Sun –  Air heated and rises –  Cools and sinks •  Prevailing winds –  Caused by Earth s rotaTon Common Storms and Weather Pa\erns •  Severe weather –  Tropical storms •  Hurricanes •  Typhoons –  Tornadoes •  Weather cycle –  El Nino Hurricane Tornado The Ongoing Process of Science •  How steady is the Earth s climate? –  Can change drasTcally and quickly •  Evidence Climate •  Long-­‐term climate –  Oceans –  Mountains –  Sunlight •  Amount radiated back to space •  PredicTon –  Global circulaTon models The Rock Cycle Igneous Rocks •  Igneous rocks –  Solidify from hot liquid •  Types –  Extrusive •  Solidify at surface –  Intrusive •  Solidify below surface The Rock Cycle Igneous Rocks Granite Sedimentary Rocks •  Sedimentary rock –  From grains of weathered rock •  FormaTon –  CompacTon –  CementaTon •  Examples –  Sandstone –  Shale –  Limestone Sedimentary Rocks Sand The Science of Life •  Coral reefs