Earthquakes vocabulary review

Huge ocean wave produced by displacement of the sea floor. Tsunami Huge ocean wave produced by displacement of the sea floor.

The difference between the arrival times of the P and S waves. Lag time The difference between the arrival times of the P and S waves.

Seismic waves that travel through Earth’s interior sill dike stock neck Body waves Seismic waves that travel through Earth’s interior

A numerical scale of earthquake magnitude. Richter scale A numerical scale of earthquake magnitude.

The central, horizontal line running through the seismogram. Baseline The central, horizontal line running through the seismogram.

Rigid outer shell of Earth, 7 to 125 km thick lithosphere Lithosphere Rigid outer shell of Earth, 7 to 125 km thick

The point on Earth’s surface above the focus. seismic fault footwall headwall Epicenter The point on Earth’s surface above the focus.

A layer of Earth beneath the lithosphere. Asthenosphere A layer of Earth beneath the lithosphere.

The height of the wave above baseline. Amplitude The height of the wave above baseline.

Anticline An upward arching fold.

Scale expressing intensities of earthquakes in Roman numerals (I-XII). Mercalli scale Scale expressing intensities of earthquakes in Roman numerals (I-XII).

Type of fault where hanging wall moves down relative to the footwall. Normal fault Type of fault where hanging wall moves down relative to the footwall.

The record of earthquake motion recorded by a seismograph. Seismogram The record of earthquake motion recorded by a seismograph.

A measure of energy released during an earthquake. Magnitude A measure of energy released during an earthquake.

A fault where the hanging wall moves up relative to the footwall. Reverse fault A fault where the hanging wall moves up relative to the footwall.

A fault in which movement is parallel to the fault surface. Strike-slip fault A fault in which movement is parallel to the fault surface.

A seismic wave that travels on Earth’s surface. sill dike stock neck Surface wave A seismic wave that travels on Earth’s surface.

Benioff zone Earthquake zone that slopes landward and downward away from the trench.

The point where seismic waves originate. fault footwall headwall Focus The point where seismic waves originate.

A downward arching fold. Syncilne A downward arching fold.