earthquake

American  

[urth-kwayk] / ˈɜrθˌkweɪk /

noun

• earthquakes
  plural

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 British  

/ 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

---

earthquake Scientific  

/ 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 Cultural  

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.)

---

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.

Discover More

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 Word Forms

Derived Forms

• preearthquake
  adjective

Inflected Forms

Nouns

• earthquakes
  plural

---

Etymology

Origin of earthquake

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

---

Compare meaning

How does earthquake compare to similar and commonly confused words? Explore the most common comparisons:

• earthquake vs. aftershock
• temblor vs. earthquake

---

Explanation

If you're visiting your friend in California and her house starts to shake, you might be experiencing an earthquake, which is the shaking of the surface of the earth that happens when there's movement deep underground. Earthquake is one of those words that means exactly what it sounds like: the earth is quaking. Earthquakes happen along "fault lines," the places where the big plates of the earth meet and rub up against each other during volcanic activities. We also use earthquake metaphorically, to talk about something that causes a violent upheaval.

Example Sentences

See Examples For:

earthquake earthquakes

He survived the great earthquake of 1906, worked in hotels and kitchens, traveled to China six times, married twice and had six children, all sons.

From The Wall Street Journal ● Nov. 1, 2026

But after an earthquake in 2024 killed hundreds of people and caused widespread damage to Japan's Noto Peninsula, Ayumi stocked up even more.

From BBC ● Oct. 31, 2026

The artificial intelligence trade may be struggling early Friday, but use of the technology is still expected by many to cause an earthquake for workers, and by extension, their ability to manage household debt.

From MarketWatch ● Oct. 30, 2026

He leads an institute behind many scientific feats: It gave birth to JPL 90 years ago, created the earthquake Richter scale and helped build the first detectors to observe cosmic gravitational waves.

From Los Angeles Times ● Oct. 29, 2026

Because on Tuesday night, the earthquake activity increased tremendously.

From "Mountain of Fire" by Rebecca E. F. Barone

Some earthquakes are felt with greatest force far from their epicenter.

From Slate ● Nov. 5, 2026

It was an era of climate change, supply chain collapse, earthquakes, famine, disease, migration, drought and armed incursions and invasions.

From Salon ● Oct. 30, 2026

It also follows devastating earthquakes in Colombia and Venezuela earlier this year.

From BBC ● Oct. 9, 2026

“You live in Florida, you worry about hurricanes. You live in California, you worry about earthquakes, mudslides,” he said.

From The Wall Street Journal ● Oct. 7, 2026

We lived in a region where earthquakes happened often, but this felt different.

From "Malala: The Girl Who Stood Up for Education and Changed the World" by Malala Yousafzai

Random Word

Spin the wheel and learn a new word!

---

Related Words

• shock
• temblor
• upheaval

---