Unit 4: Factors Impacting the Environment Test Review

Answer Key

Definitions

Ecoregion - an area defined by its environmental factors such as, climate, landforms, soil, vegetation.

Example: the Gulf Coast Region,

Piney Woods, etc.

Weathering – the breaking down of rock into smaller and smaller pieces by natural processes.

Erosion – process by which wind and water move sediment from one place to another.

Deposition – the process of laying down or “depositing” matter such as sediment, soil, or rocks down by a natural process.

Drought – an extended period of dry weather resulting in a severe shortage of water.

Tsunamis – a large wave or series of waves that is caused by an underwater earth-quake or volcanic eruption.

Volcanoes – an opening in the earth’s crust in which molten lava, ash and gases are ejected.

Hurricanes – a rotating tropical storm whose winds have reached a constant speed of 74 mph or more. Form over warm, open ocean.

Hurricanes – a rotating tropical storm whose winds have reached a constant speed of 74 mph or more. Form over warm, open ocean.

Lightning – a brilliant spark of electricity that can happen in a thundercloud, between clouds or between a cloud and the ground.

Earthquake – a shaking and vibration at the surface of the earth resulting from underground movement along a fault plane or from volcanic activity.

Questions – Explain:

1. How does a volcanic eruption affect the local environment?

A volcanic eruption can destroy an environment by burning down vegetations, structures, destroying habitats, or even cooling the earth’s temperature due to ash lingering in the air covering the sun. On the other

hand, volcanic eruptions can

cancel out weathering because

it also builds up new land.

2. List weathering agents.

Mechanical: wind, water, gravity, abrasion,

ice wedging, plants and animals.

Chemical: water, acids in precipitation (acid

rain), acid in ground water, acid inliving things, oxidation.

ice wedging

3. What is the difference between chemical and mechanical weathering?

Mechanical weathering is the breaking down of rocks into smaller pieces

by a physical means.

Chemical weathering is the breakingdown rock into a new substance by achemical means such as water, weakacids and reaction with air.

4. Explain why our earth experiences earthquakes.

The surface of the earth sits on several plates that float on the molten rock below the earth’s surface. These plates push up against each other building up a great amount of stress (potential energy). When the plates move against each other they release that stress causing an earthquake. This usually happens along a fault line. The sudden shift, or movement is an

Earthquake.

5. Name and describe a large storm that develops over an ocean.

List all names for this storm.

A hurricane is a tropical storm that develops over warm open ocean water. When the winds reach a sustained wind speed of 74 mph it is called a hurricane.

Hurricane, typhoon, cyclone.