Earthquakes and seismic activity often happen with sudden movements underground with tectonic plates. Seismographs are used by scientists to measure the time, location and strength of an earthquake.

An earthquake measuring 2.1 on the Richter scale was felt on Wednesday night in municipalities in the districts of Porto and ...

(NEXSTAR) — While areas like California and the West Coast may be top of mind when you think of where earthquakes occur in the U.S., a new report shows nearly 75% of the country could experience a ...

Earthquakes are measured using seismographs, which monitor the seismic waves that travel through the Earth after an earthquake strikes. Scientists used the Richter Scale for many years but now largely ...

Earthquake strength is registered on the moment magnitude scale, which measures how much energy was released when the rocks along a fault moved during the quake. By Henry Fountain Earthquake strength ...