Paleomagnetism

Front

What is paleomagnetism?

Back

Paleomagnetism is the study of the magnetic properties of rocks, sediments, and soils, particularly the record of Earth's magnetic field reversals over geological time.

Front

How is new crust formed without increasing Earth's surface area?

Back

New crust is formed at mid-ocean ridges while old crust is recycled in subduction zones.

Front

What happens when continental and oceanic plates converge?

Back

The oceanic plate, being denser, sinks under the continental plate.

Front

What is a magnetic field reversal?

Back

A magnetic field reversal is when Earth's magnetic field flips, causing magnetic north and south to switch places.

Front

Is it true that the magnetic north pole has always been close to the geographic North Pole?

Back

False. The magnetic north pole has moved significantly over geological time.

Front

What is the average density of continental crust?

Back

The average density of continental crust is 2.8 g/cm³.

Front

What is the average density of oceanic crust?

Back

The average density of oceanic crust is 3.2 g/cm³.

Front

What geological feature is formed at mid-ocean ridges?

Back

Mid-ocean ridges are formed where new oceanic crust is created as tectonic plates pull apart.

Front

What is subduction?

Back

Subduction is the process by which one tectonic plate moves under another plate and sinks into the mantle.

Front

What role do subduction zones play in the recycling of crust?

Back

Subduction zones recycle old crust back into the mantle while new crust is formed at mid-ocean ridges.