Acceleration
The rate at which motion changes. A seismic sensor measures acceleration over time so the shape and intensity of building movement can be recorded.
Terminology
Seismic monitoring glossary
Definitions for the main sensing, earthquake and engineering terms used on this site.
Building motion
The movement of a building during vibration or an earthquake. It is not the same as a structural safety assessment.
Event recording
A time-stamped series of sensor measurements captured around a detected shaking event for later technical review.
P wave
The primary seismic wave. It normally travels faster than other earthquake waves and may arrive first at a sensor.
S wave
The secondary seismic wave. It normally arrives after the P wave and moves material perpendicular to its direction of travel.
Sensor
The measurement component that converts physical building movement into digital data.
Seismic monitoring
The continuous or event-based measurement of ground or building motion. Monitoring supports observation; it does not certify that a building is safe.
Structural engineer
A qualified engineer who evaluates how structures behave and can interpret measurements together with inspections, plans and other evidence.