Foreshocks

An earthquake that is smaller than, and precedes, a "mainshock". Foreshocks tend to occur in the same area as the mainshock. Foreshocks have not been observed before damaging ...

foreshock

Earth science; Geology

A minor tremor that precedes an earthquake. An increase in seismicity may signal that a major release of strain energy is about to occur.

foreshock

Natural environment; Earthquake

A foreshock is an earthquake that occurs before a larger seismic event (the mainshock) and is related to it in both time and space. The designation of an earthquake as foreshock, ...

seismic survey

Earth science; Seismology

A technique for determining the detailed structure of the rocks underlying a particular area by passing acoustic shock waves into the strata and detecting and measuring the ...

shot

Earth science; Seismology

A small explosion used to produce shock waves during a seismic survey.

jug hustler

Earth science; Seismology

A member of a seismic crew who operates the geophones.

seismic exploration

Earth science; Seismology

An exploration technique involving the use of seismic methods.

seismic observer

Earth science; Seismology

A seismic observer operates geophysical recording instruments used in seismic surveys and performs routine maintenance to ensure optimum data quality.

scarp

Earth science; Seismology

A roughly linear, cliff-like slope or face that breaks the continuity of a surface into distinct levels. Scarps are often produced by faulting, especially that which involves a ...