Environmental Science

Environmental Science Earth

Water for life • Water and gases store heat • Allows Earth to maintain a steadier surface temperature than other planets. • Water is also needed by organisms- • dissolves needed nutrients • chemical reactions needed for survival occur in water

Earth is divided into 3 regions that support life: Lithosphere- layer of land that forms the Earth’s surface Hydrosphere- all areas that are made up of water Atmosphere- layer of air that surrounds the Earth

Lithosphere • outer solid part of the earth, including the crust and uppermost mantle • Varies in thickness • 10 to 200 kilometeres • Made up of 3 types of rock classified by their formation • Metamorphic • Sedimentary • Igneous http://www.ngdir.ir/sitelinks/kids/html/g1_L.htm

Metamorphic Rock • Rocks that have been transformed by heat or pressure– sometimes by both http://www.omaksd.wednet.edu/Albin/Science/vocab_wasl.htm

Sedimentary Rock • Rocks that have been broken down by compression & erosion- wind & water • Than accumulate in layers, become compressed and cemented http://orchard.sbschools.net/users/dgurwicz/fieldtrips/buttonsandboats/Sedimentary_layers.jpg

http://www.fs.fed.us/r2/gmug/permits/grand_valley/basaltrock_for_webpage.jpghttp://www.fs.fed.us/r2/gmug/permits/grand_valley/basaltrock_for_webpage.jpg Igneous Rock • Rock formed from liquid rock (magma) • Cools and forms a solid • Extrusive igneous rock comes from magma- cools at surface • Intrusive comes from the crystallization

The “Rock Cycle” http://www.freewebs.com/lexyc/

Hydrosphere • 70% Earth covered by water • 97% of hydrosphere is salt water • 3 % is fresh • 2/3 of fresh water occur in glaciers and ice caps • Availability of fresh water often determines amount and type of organisms area can support http://www.uwsp.edu/geO/faculty/ritter/glossary/h_k/hydrosphere.html

2 types of fresh water • Surface- lakes, streams, creeks, etc. • Ground- found beneath the Earth’s surface • Moves very slowly http://www.connectedwater.gov.au/images/Processes_fig1_resize.jpg

Aquifer- underground layer of porous rock that contains water source of water for many people slow to be replenished- many aquifers are beginning to dry up Artersian Well- water flows to surface due to high pressure underground Underground Water Supply http://geology.com/articles/bottled-water.shtml

Atmosphere • Layer of gases keep Earth’s temperature steady http://www.topsfieldschools.org/PROCTOR/P_Science/Atmosphere/atmosphere.jpg http://en.wikivisual.com/index.php/Air

4 Layers of Atmosphere • Troposphere- layer of the atmosphere that touches Earth’s surface • most gas molecules in the atmosphere • layer in which most weather occurs • Ground ozone • Stratosphere- 18-50 km upper stratosphere contains the Ozone layer - important to life on Earth because it filters most of the sun’s UV radiation

4 Layers of Atmosphere 3. Mesosphere- 50-85 km - coldest layer of atmosphere (temps as low as -100 °C) 4. Thermosphere- • outermost layer • temperatures as high as 2000° C • gas particles bombarded by the sun become ions and create the ionosphere • Ionosphere is an extension of the thermosphere • aurora borealis occurs when gas molecules interact with free electrons and give off light • 60-200km

Biosphere • zone of the Earth where life actually occurs -- includes all living organisms, including man, and all organic matter that has not yet decomposed • The combined parts of the lithosphere, atmosphere, and hydrosphere where life exists • can be divided into distinct ecosystems

Biosphere • Most life on Earth exists between 500 meters below the ocean’s surface to 6 km above sea level • All organisms obtain the materials they need to live in the biosphere. • They depend on the biosphere and are affected by changes to the biosphere, changes can affect organisms and organisms can create changes to an environment • Energy constantly flows through the biosphere • Most energy originates as sunlight – photosynthesis • Flows out of biosphere as heat into space

Environmental Science