Quarter 1 - Module 4

Alfred Wegener is a German scientist who proposed a theory about the history of the landmasses of the world. Which of the following theories did Wegener propose?

• Continental Drift Theory

• Seafloor Spreading Theory

• Plate Tectonics Theory

• Continental Shift Theory

Why was the theory of continental drift was not accepted by scientists despite of numerous evidences that support it?

• It was not able to provide an explanation why the continents move.

• The theory required advanced concepts inaccessible during the time.

• The scientist who proposed the theory did not have a good reputation.

• A majority of the presented evidence were found out to be fabrications.

How do oceans get wider according to the seafloor spreading theory? When magma comes out of the ocean ridge, it ____________________________________.

• pushes the old crust upwards increasing the thickness of the crust

• melts the old crust creating a heat source which boils away the ocean water

• melts the old crust creating a trench which causes the ocean to increase its water capacity

• pushes either side of ridge away from the ridge pushing the ocean floor apart while creating new crustal material

Materials in the mantle move via convection currents. Which of the following explains how a convection current is generated?

• The mantle is squeezed between the crust and the core. The heat generated from this enables convection currents to flow.

• Tectonic plates are moving. As they move, they produce friction which creates heat. This heat pushes the flow of convection currents.

• The core of the earth is much hotter than the mantle. The heat from the core flows towards the mantle fueling the convection currents.

• Heat from the sun is absorbed by the Earth’s internal layers. This constant flow of heat from the sun triggers the movement of mantle materials.

Which statement reflects the how plate tectonics explains the movement of landmasses and oceans?

• Oceans and continents are both part of the lithosphere. When a segment of the lithosphere moves, so do the oceans and continents.

• Oceanic crusts move to either side of an oceanic ridge and in the process pushes the continents to move also.

• Continental landmasses move through the unmoving oceans breaking oceanic crusts in the process.

• Continental landmasses move independently from oceanic seafloor.

Which of the following is the main concept proposed by the Seafloor Spreading Theory?

• Magma forms convection cells in the mantle.

• Continents move through unmoving oceans.

• The lithosphere of the earth is divided into segments.

• Magma coming out from ocean ridges forms new seafloor.

What is the behavior of magma in convection currents?

• Hotter magma materials rise up while cooler magma sinks down.

• Cooler magma rises up while hotter magma materials sink down.

• Magma currents rotate inside the outer core of the Earth.

• The movement of magma in the mantle is heats up the Earth’s core.

What layer of the earth serves as a heat source that initiates the formation of convection currents?

• core

• crust

• lithosphere

• mantle

Which of the following sequence correctly illustrates the progression of theories explaining why tectonic plates move?

• Seafloor Spreading → Continental Drift → Convection Currents → Earth’s Interior Layers → Plate Tectonics Theory

• Continental Drift → Seafloor Spreading → Convection Currents → Earth’s Interior Layer → Plate Tectonics Theory

• Convection Currents → Earth’s Interior Layers → Continental Drift → Seafloor Spreading → Plate Tectonics Theory

• Earth’s Interior Layers → Convection Currents → Seafloor Spreading → Continental Drift → Plate Tectonics Theory

Which of the following is a mechanical layer of the Earth?

• Core

• Crust

• Lithosphere

• Mantle