Often in these weekly Night Sky columns I refer to the magnitude of a star or planet. The concept of magnitude is relatively easy to grasp. Put simply, magnitude indicates an object’s degree of ...

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.

Earthquakes are becoming increasingly frequent. On Sunday morning, four earthquakes struck parts of India, Myanmar, and Tajikistan within just one hour, sending tremors across central and South Asia.

An earthquake rattled much of the Northeast on Friday morning, with shaking felt across the New York City metropolitan area and in communities from Baltimore and Philadelphia up through New England.

The moment magnitude scale (MMS; denoted explicitly with Mw or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on ...