Microseism

In seismology, a microseism is defined as a faint earth tremor caused by natural phenomena.[1][2] Sometimes referred to as a "hum",[3] it should not be confused with the anomalous acoustic phenomenon of the same name. The term is most commonly used to refer to the dominant background seismic and electromagnetic noise signals on Earth, which are caused by water waves in the oceans and lakes.[4][5][6][7][8] Characteristics of microseism are discussed by Bhatt.[8] Because the ocean wave oscillations are statistically homogenous over several hours, the microseism signal is a long-continuing oscillation of the ground.[9] The most energetic seismic waves that make up the microseismic field are Rayleigh waves, but Love waves can make up a significant fraction of the wave field, and body waves are also easily detected with arrays. Because the conversion from the ocean waves to the seismic waves is very weak, the amplitude of ground motions associated to microseisms does not generally exceed 10 micrometers.

  1. ^ The American Heritage Dictionary of the English Language (Fourth ed.), Houghton Mifflin Company, 2000
  2. ^ Ebel, John E. (2002), "Watching the Weather Using a Seismograph", Seismological Research Letters, 73 (6): 930–932, Bibcode:2002SeiRL..73..930E, doi:10.1785/gssrl.73.6.930.
  3. ^ Ardhuin, Fabrice, Lucia Gualtieri, and Eleonore Stutzmann. "How ocean waves rock the Earth: two mechanisms explain seismic noise with periods 3 to 300 s." Geophys. Res. Lett. 42 (2015).
  4. ^ Longuet-Higgins, M. S. (1950), "A theory of the origin of microseisms", Philosophical Transactions of the Royal Society A, 243 (857): 1–35, Bibcode:1950RSPTA.243....1L, doi:10.1098/rsta.1950.0012, S2CID 31828394
  5. ^ Hasselmann, K. (1963), "A statistical analysis of the generation of micro-seisms", Rev. Geophys., 1 (2): 177–210, Bibcode:1963RvGSP...1..177H, doi:10.1029/RG001i002p00177, hdl:21.11116/0000-0007-DD32-8
  6. ^ Kedar, S.; Longuet-Higgins, M. S.; Graham, F. W. N.; Clayton, R.; Jones, C. (2008), "The origin of deep ocean microseisms in the north Atlantic ocean" (PDF), Proc. R. Soc. Lond. A, 464 (2091): 1–35, Bibcode:2008RSPSA.464..777K, doi:10.1098/rspa.2007.0277, S2CID 18073415
  7. ^ Ardhuin, F.; Stutzmann, E.; Schimmel, M.; Mangeney, A. (2011), "Ocean wave sources of seismic noise" (PDF), J. Geophys. Res., 115 (C9): C09004, Bibcode:2011JGRC..116.9004A, doi:10.1029/2011jc006952
  8. ^ a b Bhatt, Kaushalendra M (2014). "Microseisms and its impact on the marine-controlled source electromagnetic signal". Journal of Geophysical Research: Solid Earth. 119 (12): 2169–9356. Bibcode:2014JGRB..119.8655B. doi:10.1002/2014JB011024.
  9. ^ "Microseism". Retrieved 2008-08-25.