Earth Science

What is the name of Alfred Wegener's hypothesis about moving landmasses? continental movement plate tectonics continental drift seafloor spreading

continental drift

What is thought to be the driving mechanism of plate movement? volcanoes conduction of heat in the mantle continental drifting convection currents in the mantle

Convection currents in Earth's mantle are thought to be the driving mechanism of plate movement. These currents transfer thermal heat in unequally heated material.

What was one reason that Wegener's hypothesis of continental drift was rejected? He could not explain what was moving the continents. He could not support the idea that climates of certain landmasses had been different He could not support that the continents were once adjacent. He could not explain where the continents had moved.

Wegener could not explain what was moving the continents. His suggestion of Earth's rotation being responsible was disputed by physicists.

What type of force is exerted on a tectonic plate near the part of convection current where the mantle is cooling? a rising force a sinking force an elastic force a cracking force

a sinking force. The downward part of a convection current occurs pulls the mantle downward with a sinking force. Since the mantle near the tectonic plates behaves like a solid that is attached to the tectonic plate, the plate is pulled downward at convergent boundaries.

Places where two tectonic plates are moving away from each other are called __________. convergent boundaries divergent boundaries earthquake boundaries transform boundaries

divergent boundaries

What evidence did Wegener use to estimate the time of Pangaea's break up? magnetic isochrons coal deposits ocean-floor topography fossil data

fossil data

The thickness of ocean sediments that are close to a mid-ocean ridge is __________ the thickness of ocean sediments that are far from mid-ocean ridges. more than the same as always 100 times less than

less than

When a divergent plate boundary forms on continents, a __________ forms. crater volcano mid-continent ridge rift valley

rift valley

Harry Hess' theory of __________ explained how ocean crust is generated and destroyed. continental drift continental movement seafloor spreading plate tectonics

seafloor spreading

What is the process called when one plate is forced beneath another at a convergent plate boundary? transformation subduction convergence subtraction

subduction