Science - 7 (earthquakes)

What are the two types of earthquakes mentioned in the lecture?

Tectonic earthquakes and volcanic earthquakes.

What is the focus of an earthquake?

The point of origin of seismic waves.

What distinguishes active faults from inactive faults?

Active faults have moved in the last 10,000 years, while inactive faults have not.

What causes earthquakes along fault lines?

Sudden movement along faults and plate boundaries that releases stored energy.

What type of fault occurs at divergent boundaries?

Normal faults.

What is the difference between normal dip-slip faults and reverse dip-slip faults?

Normal dip-slip faults have the hanging wall moving down relative to the footwall, while in reverse dip-slip faults, the hanging wall moves up relative to the footwall.

What type of fault has horizontal movement?

Strike-slip fault.

What effect do tectonic plate movements have on faults?

They provide stress that can cause rocks to break and generate earthquakes.

What is an oblique-slip fault?

A fault that exhibits both dip-slip and strike-slip displacements.

What happens to energy stored in rocks before an earthquake?

It is released suddenly when the rocks break, causing vibrations felt as earthquakes.