Written record of earthquake is known as archaeological evidence.
The written record is the pedigree.
Earthquakes are measured by a seismometer, also known as a seismograph.
If you are referring to the record printed on a chart by a seismograph, it is called a seismogram. If you are referring to a hand-written record of the events of an earthquake, this might be referred to as a journal.
Seismograph.
A seismometer is used to measure the strength of earthquakes.
Hansard
Studbook.
Studbook.
It's just called observations.
seismographs
Seisometer
earthquakes that immediately follow a major earthquake are called "aftershocks" as to small earthquakes before large earthquakes are called "foreshocks".