Seismology

Soil liquefaction describes a phenomenon whereby a saturated or partially saturated soil substantially loses strength and stiffness in response to an applied stress, usually earthquake shaking or other sudden change in stress condition, causing it to behave like a liquid.

P-waves are a type of elastic wave, and are one of the two main types of elastic body waves, called seismic waves in seismology, that travel through a continuum and are the first waves from an earthquake to arrive at a seismograph.

The Richter magnitude scale (also Richter scale) assigns a magnitude number to quantify the size of an earthquake.

Seismometers are instruments that measure motion of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources.

A hodograph is a diagram that gives a vectorial visual representation of the movement of a body or a fluid.

The epicenter, epicentre /ˈɛpɪsɛntər/ or epicentrum is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates.

A quake is the result when the surface of a planet, moon or star begins to shake, usually as the consequence of a sudden release of energy transmitted as seismic waves, and potentially with great violence.

Long period ground motion is ground movement during an earthquake with a period longer than 1 second.

A seismic metamaterial, is a metamaterial that is designed to counteract the adverse effects of seismic waves on artificial structures, which exist on or near the surface of the earth.

Induced seismicity refers to typically minor earthquakes and tremors that are caused by human activity that alters the stresses and strains on the Earth's crust.

In seismology, an isoseismal map is used to show lines of equal felt seismic intensity, generally measured on the Modified Mercalli scale.