Mohorovičić discontinuity

American  

[moh-haw-roh-vuh-chich dis-kon-tn-oo-i-tee, -hoh-, -yoo-] / ˌmoʊ hɔˈroʊ və tʃɪtʃ ˌdɪs kɒn tnˈu ɪ ti, -hoʊ-, -ˈyu- /

Also Moho

noun

Geology.

1. the discontinuity between the crust and the mantle of the earth, occurring at depths that average about 22 miles (35 km) beneath the continents and about 6 miles (10 km) beneath the ocean floor.

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Mohorovičić discontinuity British  

/ ˌməʊhəˈrəʊvɪtʃɪtʃ /

noun

1. Often shortened to: Moho.  the boundary between the earth's crust and mantle, across which there is a sudden change in the velocity of seismic waves

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Mohorovičić discontinuity Scientific  

/ mō′hə-rō′və-chĭch /

1. The boundary between the Earth's crust and mantle, located at an average depth of 8 km (5 mi) under the oceans and 32 km (20 mi) under the continents. The velocity of seismic primary waves across this boundary changes abruptly from 6.7 to 7.2 km (4.1 to 4.5 mi) per second in the lower crust to 7.6 to 8.6 km (4.7 to 5.3 mi) per second in the upper mantle. The boundary is estimated to be between 0.2 and 3 km (0.1 and 1.9 mi) thick and is believed to coincide with a change in rock type from basalts (above) to peridotites and dunites (below). It is named after its discoverer, Croatian seismologist Andrija Mohorovičić (1857–1936).

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Etymology

Origin of Mohorovičić discontinuity

1935–40; named after Andrija Mohorovičić (1857–1936), Croatian geophysicist, who discovered it

Example Sentences

The dividing line between the crust and the mantle is called the Mohorovičić discontinuity, or "the Moho."

From Science Daily • Feb. 20, 2026

Normally, the crust–mantle boundary is thought to be marked by a feature known as the Mohorovičić discontinuity, or ‘Moho’, at which seismic waves change velocity.

From Nature • Nov. 30, 2015

The drilling project planned to study the Mohorovičić discontinuity, situated at a depth of 15 kilometers.

From Scientific American • Apr. 1, 2013

He had discovered the boundary between the crust and the layer immediately below, the mantle; this zone has been known ever since as the Mohorovičić discontinuity, or Moho for short.

From "A Short History of Nearly Everything" by Bill Bryson