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blocky lava



Acid rain

precipitation that incorporates anthropogenic acids and acidic materials; ph below 5, H2SO4; HNO3

Active Solar Heating

generally pump at a heat absorbing fluid medium through a small collector, such as air or water

Acute Toxicity

substances that are slightly harmful to your health when ingested or inhaled


modifying slightly to fit a new set of conditions

Amazon River

the largest river; runs through South America


Minute particles or liquid droplets suspended in the air


living or occurring only in the presence of oxygen

Air Mass

large volume of air defined by its temperature and water vapor content

Air pollution

damaging materials released into the environment

Algal Bloom

bloom of algae; caused by excess nutrients (nitrates and phosphates)


level of alkaline in a substance; pH 7.1-14


biochemical interactions among all types of plants including microorganisms


a description of a surface's reflective properties

Ambient air

the air immediately around us


pungent colorless gas


ammonium compounds in the decomposition of organic matter

Anadromous Species

fresh water fish that swim to ocean, and return to fresh water


lives or occurs without oxygen


human-caused or resulting from the influence of human beings


water-bearing layers of sand, gravel, and rock below Earth's surface

Aral Sea

4th largest lake in the world, no outlet, the evaporation keeps the water from rising

Army Corps of Engineers

provide vital public security, energize the economy, reduce risk for disasters


highly toxic metalloid widely spread through nature; in the soils in the West


fibris mineral that does not burn, utilized for fire protection


the remains of burned objects


nitrogen compounds are incorporated into proteins & DNA

Aswan High Dam

It was built in 1956 to control the flooding of the Nile River. The dam gives Egyptian farmers a more dependable source of water for their crops. It also gives Egypt electrical power.


a gasous layer that envelopes the Earth; N2 78%, O2 20.94%, Argon .9%, CO2 0.38%

Atmospheric inversion

warm layer traps a cool layer beneath it

Automobile emissions

variety of gasses caused by internal combustion engines (VOC, Nitrous Oxides, CO2, CO)

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