It is where two plates are moving apart.

He proposed the seafloor spreading theory.

Seafloor spreading occurs at ______ plate boundaries.

It is a scientific theory that explains

how major landforms are created as a result

of Earth’s subterranean movements.

________ occur when one or both of the tectonic

plates are composed of oceanic crust.

Wegener was convinced that all of Earth’s continents were once part of an enormous, single landmass called 

It is a system for the detection of objects under water and for measuring the water's depth by emitting sound pulses and

detecting or measuring their

return after being reflected.

It is where two plates slide passed each other.

He proposed the Continental Drift Theory.