Module 1 Dynamic Earth

The early development of the theory of plate tectonics was supported by which of these observations?

• matching fossils on the continents of Africa and South America

• glacier deposits far from existing continental glaciers

• thick sediment layers at the mouths of rivers

• sudden volcanic activity of long-dormant volcanoes

According to the table, as the magnitude of earthquakes increases, the distance that tremors will be felt ____.

• increases

• decreases

• increases, then decreases

• remains the same

A geologist checks her seismometer for activity after an earthquake that occurs on the other side of Earth. The instrument records P-waves, but not S-waves. What statement explains why S-waves are not recorded?

• Seismometers do not record evidence of S-waves.

• S-waves travel in a different direction than P-waves.

• The earthquake was not strong enough to produce S-waves.

• The S-waves were stopped by a liquid interior layer.

Based on the diagram, which process explains why less dense, hot magma rises to the surface to displace more dense, cooler magma?

• conduction

• diffusion

• radiation

• convection

This map shows the continents as they appear on Earth's surface today. It would be correct to say that in another 50 years the continents will ___

• have moved to entirely new positions.

• be in almost the same positions as they are in today.

• have joined to become one large continent.

• be moving much faster than they are today.

The best evidence that the continents were once connected is that they have matching ___

• weather, fossils, and rock types.

• rock types, fossils, and coastlines.

• coastlines, weather, and rock types.

• coastlines, weather, and fossils.

The Mid-Atlantic Ridge exists between the African and South American geologic plates. Which process most often occurs at the Mid-Atlantic Ridge?

• destruction of underwater mountains

• creation of new continents

• subduction of geologic plates

• seafloor spreading

Which area of the diagram shows the subduction zone?

• 1

• 2

• 3

• 4

The following diagram shows a cross-section of the mid-Atlantic Ridge. Which area is likely the oldest crust?

• 1

• 2

• 3

• 4

Which of the following is the best evidence that Earth's continents were once in vastly different positions than they are today?

• Penguins are found only in the Southern Hemisphere.

• Fossils of tropical plants are found in Antarctica.

• Volcanoes encircle the Pacific Ocean.

• Major rivers form deltas from continental erosion.