Harmonic tremor
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A harmonic tremor is a sustained release of seismic and infrasonic energy typically associated with the underground movement of magma, the venting of volcanic gases from magma, or both. It is a long-duration release of seismic energy, with distinct spectral lines, that often precedes or accompanies a volcanic eruption. More generally, a volcanic tremor is a sustained signal that may or may not possess these harmonic spectral features. Being a long-duration continuous signal from a temporally extended source, a volcanic tremor contrasts distinctly with transient sources of seismic radiation, such as tremors that are typically associated with earthquakes and explosions.
Nonvolcanic, episodic tremor has now been described,[1] and is distinguished by the term episodic tremor and slip (ETS) which may occur in slow earthquakes.
The relation between long-period events and an imminent eruption was first observed by Bernard Chouet, a volcanologist who was working at the United States Geological Survey.[2][3][4]
See also
[edit]Notes
[edit]- ^ Obara, Kazushige (2002). "Nonvolcanic Deep Tremor Associated with Subduction in Southwest Japan". Science. 296 (5573): 1679–1681. Bibcode:2002Sci...296.1679O. doi:10.1126/science.1070378. PMID 12040191. S2CID 32354691.
- ^ Chouet, Bernard A. (1996). "Long-period volcano seismicity: its source and use in eruption forecasting". Nature. 380 (6572): 309–316. Bibcode:1996Natur.380..309C. doi:10.1038/380309a0. ISSN 0028-0836. S2CID 4341826.
- ^ Interview with Bernard Chouet regarding his research into long-period events and volcanic eruptions: http://www.esi-topics.com/volcanoes/interviews/BernardChouet.html Archived 2009-02-01 at the Wayback Machine .
- ^ U.S. TV program on use of long-period events to predict volcanic eruptions: "Nova: Volcano's Deadly Warning": https://www.pbs.org/wgbh/nova/volcano/ . See also "Volcano Hell" episode of BBC TV series "Horizon" on same subject: http://www.bbc.co.uk/science/horizon/2001/volcanohell.shtml .
External links
[edit]- Seismicity, low frequency events and tremor at the Katla subglacial volcano, Iceland
- The harmonic tremors of a volcanic eruption Archived 2012-03-16 at the Wayback Machine