Earthquakes




Current Earthquake Activity USGS

4.0+ Earthquakes Worldwide in the Last 30 Days








Paul Giamatti in a scene from the 2015 film San Andreas

Whatever affects one part of a tectonic plate affects the entire plate.




An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.

At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.

In its most generic sense, the word earthquake is used to describe any seismic event - whether a natural phenomenon or an event caused by humans - that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its focus or hypocenter. The term epicenter refers to the point at ground level directly above the hypocenter.

Read more ...





EARTHQUAKE INDEX


PLANET EARTH


TSUNAMI


PLATE TECTONICS


POLE SHIFTS


CRUSTAL DISPLACEMENT


CONTINENTAL DRIFT


EARTH'S ENERGY GRIDS


GEOLOGY


PACIFIC RING OF FIRE


VOLCANOES


PROPHECIES


PLANET EARTH INDEX


PHYSICAL SCIENCES INDEX



ALPHABETICAL INDEX


CRYSTALINKS HOME PAGE


PSYCHIC READING WITH ELLIE


BOOK: THE ALCHEMY OF TIME


DONATION TO CRYSTALINKS


ADVERTISE ON CRYSTALINKS