help in geology

9/22/13 5:26 PM

What is the definition of a hypothesis?

Select one:

a. The end result of the scientific method.

b. Data discovered by scientists.

c. A theory developed through years of experience.

d. An explanation for a natural phenomenon.

Boundaries between Earth’s layers Select one:

a. are unreachable to humans, so they must be studied by indirect methods.

b. are defined by abrupt changes in earthquake-wave velocities.

c. are places where there’s abrupt change in the density of rock.

d. divide the Earth into three major layers (crust, mantle, and core) and several sublayers.

e. All the possible answers are correct.

Earth is round because Select one:

a. erosion over time has worn down the jagged edges of its planetesimals.

b. its interior rock is warm enough to flow slowly in response to gravity.

c. solar wind has shaped it.

d. the gravitational tug of the Moon has worn down the jagged edges.

e. the gravitational tug of the Sun has worn down the jagged edges.

Changes in the positions of continents; the amount of volcanic activity; the uplift of land surfaces; the formation of coal, oil, and organic shale; and life evolution events all contribute to short-term climate change. Select one:

a. True

b. False

Methane, carbon dioxide, and several trace gases (including water) are all greenhouse gases that cause the atmosphere to cool by reflecting large amounts of solar energy back into space.
Select one:

a. True

b. False


It is generally believed that humans began to significantly modify the environment about how long ago?
Select one:
a. 8 Ka, near the start of agricultural-based societies
b. 4–5 Ka, near the “dawn of civilization”
c. 2 Ka, the birth of Christ
d. ~250 years ago, during the Age of Industrialization

How much has atmospheric CO2 increased in approximately the last 50 years, according to the record for Hawaii’s Mauna Loa observatory, in the figure below?

Select one:

a. from about 220 to 320 ppm (parts per million)

b. from about 360 to 400 ppm

c. from about 310 to 390 ppm

d. from about 220 to 400 ppm

The factors that affect Earth’s long-term climate are different from those that affect climate on shorter time scales.
Select one:

a. true

b. false

According to Milankovitch, which of the following is a contributing factor to ice-age cycles?

Select one:

a. sunspot cycles

b. variations in ocean temperature

c. shifting continental positions due to plate tectonics

d. increased amounts of volcanic ash

e. variations in the shape of Earth’s orbit

Continental ice sheets today are found only in Select one:

a. Alaska and Iceland.

b. Antarctica and Iceland.

c. Antarctica and Greenland.

d. Greenland and Iceland.

e. Alaska and Antarctica.

Which type of moraine can a glacier have only one of? Select one:

a. recessional

b. end

c. medial

d. terminal

e. lateral