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.

About 55 earthquakes a day – 20,000 a year – are recorded by the National Earthquake Information Center. Most are tiny and barely noticed by people living where they happen. But some are strong enough ...

Earthquakes are natural phenomena caused by the sudden release of energy in the Earth’s crust, resulting in seismic waves. The magnitude of an earthquake is measured using the Richter scale, which ...

Scientists measure both the energy released in an earthquake and its damage. In 1902, Italian scientist Giuseppe Mercalli introduced a scale that measures the intensity of an earthquake based on its ...

For some residents, the morning shake was a reminder of a powerful quake that also struck near Anchorage in late November, at ...

An earthquake registering an intensity of upper 5 on Japan's seismic scale of zero to 7 has hit the Aso region of Kumamoto Prefecture, in the southwestern part of the country.