Geology and Earth Structure

A fault is a fracture or zone of fractures between two blocks of rock. When stress builds up and the rock breaks, movement along the fault causes an earthquake.

When rocks break or slip along a fault, the stored elastic energy is released in the form of seismic waves that travel through the Earth.

Magma typically collects in a magma chamber, travels up through a conduit or channel, and exits through the vent of the volcano.

Earthquakes occur most frequently at the boundaries where tectonic plates meet, as the movement and friction between these plates release energy.

The crust is solid, and the inner core is solid due to extreme pressure. The mantle is semi-solid (plastic), and the outer core is liquid.

The mantle is the thickest layer of the Earth, making up the majority of the Earth's volume.

Subduction occurs when one tectonic plate moves under another, forcing it into the mantle where it melts and can lead to volcanic activity.

The San Andreas Fault is a classic example of a transform plate boundary, where two tectonic plates slide horizontally past each other. Convergent boundaries involve collision, while divergent boundaries involve separation.

Divergent boundaries occur where tectonic plates move away from each other. This movement often allows magma to rise and create new crust.

Convergent boundaries occur where two tectonic plates move toward each other and collide. This process can lead to mountain building or subduction zones.

The lithosphere, which includes the crust and the uppermost part of the mantle, is broken into tectonic plates. The crust is the outermost layer.

Continental drift is the hypothesis that Earth's continents have moved over geological time relative to each other. Plate tectonics is the broader theory explaining how they move.