Glossary of earthquake terms
|
Seismograph
Seismometer
A seismograph, or
seismometer, is an instrument used to detect and record earthquakes.
Generally, it consists of a mass attached to a fixed base. During
an earthquake, the base moves and the mass does not. The motion
of the base with respect to the mass is commonly transformed into
an electrical voltage. The electrical voltage is recorded on paper,
magnetic tape, or another recording medium. This record is proportional
to the motion of the seismometer mass relative to the earth, but
it can be mathematically converted to a record of the absolute
motion of the ground. Seismograph generally refers to the
seismometer and its recording device as a single unit. ( See also
Earthquake
ABC's and FAQ discussion.)
|
|