Astronomy Chapter 7

Clouds form primarily at the boundary between:

the troposphere and the stratosphere.

When two tectonic plates collide:

they continue moving, producing a variety of large deformations.

At what phase are the tides least noticeable?

third quarter

At Earth's geographic North Pole, a magnetic compass needle would point (approximately)

toward Kansas City.

If you were making a scale model of Earth representing our planet by a 12-inch basketball, the indoor core would be about the size of _____

2-inch Golf Ball

Why is the sky blue?

The atmosphere scatters the light from the Sun.

What is true of spring tides?

The difference between low and high tides would be greatest.

The deepest that geologists have drilled into Earth is about the same as

the altitude most commercial jet airplanes fly.

What can we conclude about the structure of Earth's interior knowing that the average density of Earth is higher than the average density of the rock on the continents and seafloor?

that Earth's most dense material must be beneath the surface

A region where a denser basaltic plate is subducted under a continental one is:

the Nazca Trench.

When strong solar winds are displaced poleward by our magnetic fields, we get:

intense auroral displays.

The Dynamo Theory holds that:

magnetic fields are generated by rapidly spinning, fluid magnetic interiors

What gas is the primary constituent of our atmosphere?

nitrogen

If Earth had no Moon, then tides would

occur with the same frequency, but would not be as strong.

The critical part of the atmosphere for protecting life on the ground from excessive ultraviolet radiation is the:

ozone layer.

What event triggered the dramatic increase in atmospheric carbon dioxide concentration seen over the last couple of centuries?

the Industrial Revolution

Due to plate tectonics, the width of the Atlantic Ocean is separating at a rate about the same as the growth of

human fingernails.

Which layer of the Earth is unique among the terrestrial planets?

hydrosphere

The principal greenhouse gases in our present atmosphere are:

water vapor and carbon dioxide.

Earth's average density is about the same as that of _____

Chunk of Black Volcanic Rock

Australia is composed of relatively old and thick _____

Continental Crust

What is the hole in the ozone layer thought to be caused by?

CFCs

If seismometers registered P- and S-waves everywhere on the Moon, they would suggest that the moon had _____

No Molten Cored

The region around Earth where the magnetic field traps charged particles is the:

Van Allen Radiation Belts.

What is the process that physically transfers heat from a lower (hotter) to a higher (cooler) level?

convection

At what phase would tidal variation be the least during the entire day?

first quarter

From the center outward, what is the correct order of Earth's core?

solid metallic inner core, molten metal outer core, silicate mantle and crust.

The earthquakes that occur in SoCal generally occur above a _____

Fault

Ole Faithful Geyser at Yellowstone National Park in the United States acquires its energy from a _____

Hot Spot

_____ found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock

Seafloor Crust

The slowly increasing distance between South America and Africa is due to _____

Seafloor Spreading

Layered _____ exposed by erosion can be seen when looking at the Grand Canyon in the United States

Sedimentary Rock