Chapter 2 - A Living Planet

Question 0

In 1912, Alfred Wegener of Germany presented a new idea about continents— ___________. It maintained that the earth was once a supercontinent that divided and slowly drifted apart over millions of years.

Answer 0

the continental drift hypothesis

Question 1

On June 30, 1908, at about 7:30 A.M., an explosion occurred over the _________ . This event might have been an asteroid hit.

• The force of the explosion was estimated at between 10 and 20 megatons of TNT.
• The fireball and explosion were seen and felt 500miles away.
• Five hundred thousand acres of forest were flattened and burned.
• More than 600 grazing reindeer were roastedinstantly.
• No crater could be found

Answer 1

Tunguska region of Siberia

Question 2

The ________ is the continous circulation of water between the atmosphere, the oceans, and the earth

Answer 2

hydrological cycle

Question 3

Geographers call an area drained by a major river and its tributaries a _______.

Answer 3

drainage basin

Question 4

The water held in the pores of rock is called _______.

Answer 4

ground water

Question 5

The _______ can rise or fall depending on the amount of precipitation in the region and on the amount of water pumped out of the ground.

Answer 5

water table

Question 6

_______ are naturally formed features on the surface of the earth.

Answer 6

Landforms

Question 7

The earth’s surface from the edge of a continent to the deep part of the ocean is called the ________.

Answer 7

continental shelf

Question 8

________ is the difference in elevation of a landform from its lowest point to its highest point.

Answer 8

Relief

Question 9

___________ is the combination of the surface shape and composition of the landforms and their distribution in a region

Answer 9

Topography

Question 10

Riding above this circulationsystem are the ________, enormous moving pieces of the earth’s lithosphere.

Answer 10

tectonic plates

Question 11

Plates that move apart, spreading horizontally are called ________.

Answer 11

Divergent boundaries

Question 12

Plates collide, causing either one plate to dive under the other or the edges of both plates to crumple.

Answer 12

Convergent boundary

Question 13

When plates slide past oneanother _______ is occuring

Answer 13

Transform boundary

Question 14

However, sometimes the rock is not flexible and will crack under the pressures exerted by the plate movement. This fracture in the earth’s crust is called a ________.

Answer 14

Fault

Question 15

As the plates grind or slip past each other at a fault, the earth shakes or trembles. This sometimes violent movement of the earth is an ___________.

Answer 15

earthquake

Question 16

A ______ measures the size of the waves created by an earthquake.

Answer 16

seismograph

Question 17

“The point directly above the focus on the earth’s surface is the ________.

Answer 17

epicenter

Question 18

The _______uses information collected by seismographs to determine the relative strength of an earthquake.

Answer 18

Richter Scale

Question 19

An _________ is the sudden release of energy in the form of motion.

Answer 19

earthquake

Question 20

Sometimes an earthquake causes a _______, a giant wave in the ocean.

Answer 20

tsunami

Question 21

Magma, gases, and water from the lower partof the crust or the mantle collect in underground chambers. Eventually the materials pour out of a crack in the earth’s surface called a _______.

Answer 21

volcano

Question 22

“Magma that has reached the earth’s surface is called ______.

Answer 22

lava

Question 23

_______, a zone around the rim of the Pacific Ocean, is the location of the vast majority of active volcanoes.

Answer 23

The Ring of Fire

Question 24

External forces, suchas weathering and erosion, also alter landscapes and in some instances create the soil that is needed for plant life. _______ refers to physical and chemical processes that change the characteristics of rock on or near the earth’s surface.

Answer 24

Weathering.

Question 25

Weathering processes create smaller and smaller pieces of rock called _______. ________ is mostly identifiable as either mud, sand, or silt, which is very fine particles of rock.

Answer 25

Sediment

Question 26

Processes that break rock into smaller pieces are referred to as ____________. ____________does not change the composition of the rock—only its size.

Answer 26

mechanical weathering

Question 27

_____________ occurs when rock is changed into a new substance as a result of interaction between elements in the air or water and the minerals in the rock. Decomposition, or breakup, can happen in several ways. Some minerals react to oxygen in the air and begin to crumble. That is what happens when iron rusts, for example.

Answer 27

Chemical Weathering

Question 28

________ occurs when weathered material is moved by the action of wind, water, ice, or gravity.

Answer 28

Erosion

Question 29

For erosion to occur, a transporting agent, such as water, must be present. ________, ________, ________, or ________ cause erosion by grinding rock into smaller pieces.

Answer 29

Glaciers, waves, stream flow, or blowing winds

Question 30

The texture of the soil, the amount of organic material called ______, and the amount of air and water in the soil all contribute to the soil’s _____—its ability to nurture plants.

Answer 30

humus; fertility