Mohorovičić discontinuity definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The boundary between the earth's crust and the underlying mantle, averaging 8 kilometers (5 miles) in depth under the oceans and 32 kilometers (20 miles) in depth under the continents.
Origin: After Andrija Mohorovičić (1857-1936), Croatian geophysicist.
mohorovičić discontinuity - Science Definition
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).