[ mahy-kruh-sahy-zuh m, -suh m ]
/ ˈmaɪ krəˌsaɪ zəm, -səm /

noun Geology.

a feeble, recurrent vibration of the ground recorded by seismographs and believed to be due to an earthquake or a storm at sea.

Origin of microseism

First recorded in 1885–90; micro- + seism

Related forms

mi·cro·seis·mic, mi·cro·seis·mi·cal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for microseism


/ (ˈmaɪkrəʊˌsaɪzəm) /


a very slight tremor of the earth's surface, thought not to be caused by an earthquake

Derived Forms

microseismic (ˌmaɪkrəʊˈsaɪzmɪk) or microseismical, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for microseism


[ mīkrə-sī′zəm ]

A faint Earth tremor, unrelated to earthquakes, caused by natural phenomena, such as winds and strong ocean waves.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.