earthquake

[ urth-kweyk ]

noun

1. a series of vibrations induced in the earth's crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating.

   Synonyms: temblor, seism, shock, tremor, quake

2. something that is severely disruptive; upheaval.

earthquake

/ ˈɜːθˌkweɪk /

noun

1. a sudden release of energy in the earth's crust or upper mantle, usually caused by movement along a fault plane or by volcanic activity and resulting in the generation of seismic waves which can be destructive seismic

earthquake

/ ûrth′kwāk′ /

1. A sudden movement of the Earth's lithosphere (its crust and upper mantle). Earthquakes are caused by the release of built-up stress within rocks along geologic faults or by the movement of magma in volcanic areas. They are usually followed by aftershocks.
2. See Note at fault

earthquake

1. A tremor of the surface of the Earth , sometimes severe and devastating, which results from shock waves generated by the movement of rock masses deep within the Earth, particularly near boundaries of tectonic plates . ( See fault , Richter scale , and seismology .)

Notes

Earthquakes are particularly likely where such plates are sliding past each other, as in the San Andreas Fault .

Earthquakes cannot be accurately predicted, although the likelihood of a region's suffering an earthquake can be estimated.

Other Words From

• pre·earthquake adjective

Word History and Origins

Origin of earthquake¹

1300–50; Middle English erthequake ( earth, quake ), replacing Old English eorthdyne ( din ¹ )

A Closer Look

Fractures in Earth's crust, or lithosphere, where sections of rock have slipped past each other are called faults. Earthquakes are caused by the sudden release of accumulated strain along these faults, releasing energy in the form of low-frequency sound waves called seismic waves. Although thousands of earthquakes occur each year, most are too weak to be detected except by seismographs, instruments that detect and record vibrations and movements in the Earth. The point where the earthquake originates is the seismic focus, and directly above it on Earth's surface is the earthquake's epicenter. Three kinds of waves accompany earthquakes. Primary (P) waves have a push-pull type of vibration. Secondary (S) waves have a side-to-side type of vibration. Both P and S waves travel deep into Earth, reflecting off the surfaces of its various layers. S waves cannot travel through the liquid outer core. Surface (L) waves—named after the nineteenth-century British mathematician A.E.H. Love—travel along Earth's surface, causing most of the damage of an earthquake. The total amount of energy released by an earthquake is measured on the Richter scale. Each increase by 1 corresponds to a tenfold increase in strength. Earthquakes above 7 on the Richter scale are considered severe. The famous earthquake that flattened San Francisco in 1906 had a magnitude of 7.8.

Example Sentences

Continuous buildup of carbon dioxide underground, he says, could drive earthquakes, which fracture Earth’s crust and allow more CO2 to creep upward, which in turn generates more quakes.

From Science News

When they do, they can raise up mountains, cause earthquakes — and open up volcanoes.

From Science News For Students

Phenomena like earthquakes and ocean tides continually knock Earth’s rotation off-kilter, requiring constant correction of GPS satellite signals.

From Science News

While this is not the first time Ghana’s capital has experienced earth tremor, the frequency and intensity of recent tremors have left many residents worried about an imminent major earthquake.

From Quartz

Christchurch, New Zealand, transitioned to telework after earthquakes rocked the country in 2010 and 2012.

From Voice of San Diego

But on Thursday Boxer triggered a Golden State political earthquake, announcing that she would not seek a fifth term in 2016.

From The Daily Beast

In 1997, an earthquake in Assisi caused the collapse of the main cathedral and killed ten people.

From The Daily Beast

In 2010 Cuba provided the largest contingent of medical staff during the aftermath of the huge earthquake that shook Haiti.

From The Daily Beast

The earthquake sparked a surge in religious belief in Japan.

From The Daily Beast

It is a glimpse at life exactly as it was at 3:32 am on April 6, 2009 when the earthquake stopped time.

From The Daily Beast

An earthquake completely destroyed Schiraz in Persia; 12,000 lives were lost.

From Project Gutenberg

She is always in fear of an earthquake, and feels safer to have a light burning in readiness all night long.

From Project Gutenberg

Matthew, in his account of the fact of the Resurrection, says that there was an earthquake when the angel rolled away the stone.

From Project Gutenberg

A terrible earthquake happened at Pekin, in China, throwing down houses and burying more than 1,000 inhabitants in the ruins.

From Project Gutenberg

The town of Praia, in the island of Terceira, completely destroyed by an earthquake.

From Project Gutenberg

Related Words

• shock
• temblor
• upheaval