Geology Flashcard

Front

What is sea-floor spreading?

Back

Sea-floor spreading is the process by which new oceanic crust is formed at mid-ocean ridges and gradually moves away from the ridge, causing the ocean floor to expand.

Front

Where are the youngest rocks in the ocean floor found?

Back

The youngest rocks in the ocean floor are found near mid-ocean ridges.

Front

What was a major reason Wegener's hypothesis of continental drift was rejected?

Back

Wegener could not explain how the continents could move through the ocean floor.

Front

What method do scientists use to determine the structure of Earth's interior?

Back

Scientists use seismic waves to determine what Earth's interior looks like.

Front

What drives mantle convection?

Back

Mantle convection is driven by the heat from the cooling of Earth's interior and the decay of radioactive isotopes.

Front

What are P waves?

Back

P waves are primary waves that cause Earth to vibrate in the direction of the wave's motion.

Front

What are S waves?

Back

S waves are secondary waves that cause Earth to vibrate at right angles to the direction the wave moves.

Front

What is the lithosphere?

Back

The lithosphere is the rigid outer layer of the Earth, consisting of the crust and the upper mantle.

Front

What is the asthenosphere?

Back

The asthenosphere is the semi-fluid layer of the mantle beneath the lithosphere, allowing for the movement of tectonic plates.

Front

What is a tectonic plate?

Back

A tectonic plate is a large slab of solid rock that makes up the Earth's lithosphere and moves over the asthenosphere.