Download EnvSci Chapter 3 Review Answers

Environmental Science
Name _Key_____________________ Period ___ Date _______
Chapter 3 - The Dynamic Earth
Review
The Geosphere
Compositional Layers (list all three and give a brief description of each):
1. _Crust_ - _The hard outer surface of the Earth_
2. _Mantle_ - _The moving inner portion of the Earth_
3. _Core_ - _Dense center of the Earth_
Structural Layers (list all three and give a brief description of each):
1. _Lithosphere_ - _Cool rigid outer layer of the Earth, contains the Crust and the top of the Mantle_
2. _Asthenosphere_ - _The Plastic layer that flows very slowly and causes techtonic motion_
3. _Mesosphere_ - _The middle layer of the Earth_
4. _Outer Core_ - _The dense liquid layer of the Earth made of liquid nickel and iron_
5. _Inner Core_ - _The dense solid layer of the Earth made of nickel and iron, made solid by extreme pressure_
Define:
Magma - _Molten rock found underground_
Tectonic Plate - _The large sections of lithosphere that float around on the mantle_
Earthquake - _Vibrations along faults as the plates slip past each other_
Volcano - _A mountain made from magma as it erupts through the surface of the Earth_
Mudflow - _When hot ash from a volcano mixes with water to form a deadly mudslide_
Erosion - _When wind or water or slowly deteriorate the surface of the Earth_
What is the temperature of the inner core? _4000oC -5000oC_ (make sure you give a unit!)
What causes the inner core to be solid? _intense pressure_
In which geologic zone is 1/3 of the Earth’s mass found? _The Core (both Inner and Outer Core)_
Where does most geologic activity happen? _Tectonic plate boundaries_
What is the scale used to measure earthquakes? _Richter Scale_
How do mountain ranges form? _Collisions between two tectonic plates_
What two things cause erosion? _wind_ & _water_
How can volcanoes affect sunlight reaching the Earth? _They can emit large clouds of ash into the atmosphere and block
incoming sunlight_
The Atmosphere
List all four layers and describe the temperature variation as you go up:
1. _Thermosphere_ - _2000 oC+ zone of extremely thin Nitrogen and Oxygen_
2. _Mesosphere_ - _The coldest layer of the atmosphere_
3. _Stratosphere_ - _Home of the ozone and gradually warming from the Troposphere, warmer as you go up_
4. _Troposphere_ - _The level we live in, becomes less dense and colder as you go up_
What is the most abundant gas in the atmosphere? _Nitrogen_
What is the second most abundant gas in the atmosphere? _Oxygen_
What is the ozone layer? _A layer of O3 (oxygen) that is really good at absorbing UV radiation_
Where is the ozone layer found? _The Stratosphere_
What causes the density of the troposphere to increase as you get closer to the Earth? _Gravity and the pressure of the
layers above_
What organisms produce oxygen? _Plants, algae, phytoplankton_
What causes weather? _Movement of air in the Troposphere_
Define:
Conduction - _Transfer of heat energy by direct contact_
Convection - _Transfer of heat by circular currents (happens in the oceans, the mantle and the atmosphere)_
Radiation - _Transfer of energy by electromagnetic waves, and it can happen through space_
What effect do Greenhouse gases have on the environment? _Trap heat in the atmosphere like a blanket_
How much of the sun’s radiation reaches the Earth? _2 billionths_
How much of that energy actually makes it through the atmosphere to the Earth? _About 50%_
What happens to the rest of that energy? _It is absorbed, scattered or reflected_
What is the hottest layer of the atmosphere? _Thermosphere_
The Hydrosphere
The Water Cycle (list all three parts and give a brief description of each):
1. _Evaporation_ - _When liquid water is heated and becomes water vapor_
2. _Condensation_ - _Water vapor forms droplets on dust particles_
3. _Precipitation_ - _Large droplets join together and eventually fall from the sky (rain, snow, sleet or hail)_
Define:
Salinity - _Salt concentration_
Tributary - _Smaller streams or rivers that flow into larger ones_
Groundwater - _Water that is filtered slowly into the Earth_
Aquifer - _A rock layer that stores and allows the flow of groundwater_
Recharge Zone - _The surface of the land where water enters an aquifer_
Where is most fresh water found? _Glaciers and polar ice_
Why does ocean water have a higher salinity than freshwater? _The salts build up as they are collected from rivers
entering the ocean, and over time the evaporation of ocean water leaves the salt behind_
Are the oceans separate bodies of water? Why or why not? _We can consider them one World Ocean because they are
all connected_
In the blanks below list the two types of currents, tell where they flow and why.
1. _surface current_ flows on the _surface of the ocean_because of _wind_
2. _deep current_ flows on the _the ocean floor_because of _convection of water_
Which of these two has the greater effect on climate? _Surface currents_
How do the oceans help maintain the Earth’s temperature? _They absorb heat energy and slowly radiate it back into
the atmosphere_
The Biosphere
Define:
Biosphere - _The part of the planet in which life can exist_
Open system - _One in which transfer of matter or energy can enter or leave_
Closed system - _One in which matter or energy do not enter or leave_
Which system is the Earth in regards to energy? _Open System_
Which system is the Earth in regards to matter? _Closed System_
What do plants require? _Sunlight_
What form of energy does sunlight take as it travels through space to the Earth? _Electromagnetic radiation_
Why is cycling of matter important to the biosphere? _There are limited resources available, as things die the matter in
them goes back into the biosphere to be recycled in future generations of life_
What are the basic requirements of life? _Liquid water_, _ temperatures between 10oC and 40oC_ & _a source of
energy_
What are phytoplankton? _Microorganisms that produce energy storing molecules using sunlight and release oxygen
into the atmosphere_
Name three ways gravity helps all of these systems function the way they do:
1. _Causes increases in pressure and temperature as you get closer to the center of the Earth_
2. _Allows convection in the mantle, atmosphere and hydrosphere_
3. _It keeps the gases at the surface of the Earth and the solid materials in the center_