What is an Earthquake?
An earthquake is the vibration, produced by a rapid release of seismic earth.
- Caused by accumulation and sudden release of stress in the crust
- Transmitted in the form of seismic waves
- Radiates in all directions from its source (the focus, or hypocenter)
- Instruments around the world record an event by measuring the wave motions
- Most EQs are associated with movement on faults
- initiation of new faults- occasionally
- new movement on old faults- vast majority
- Most of the stress and motion along faults can be explained by plate tectonics
- Earthquakes are happening all the time, but most are not felt by people: https://earthquake.usgs.gov/earthquakes/map/?extent=15.45368,-140.36133&extent=55.87531,-49.6582
