Encyclopedia of Natural Hazards

2013 Edition
| Editors: Peter T. Bobrowsky

Harmonic Tremor

Reference work entry
DOI: https://doi.org/10.1007/978-1-4020-4399-4_163

Definition

Harmonic tremor is defined as seismicity consisting of a continuous low frequency, often single frequency, sine wave with smoothly varying amplitude, and is caused by complex interactions between magma (see  Magma), exsolved gases, and bedrock at volcanoes (McNutt, 2000).

Harmonic tremor comprises a sequence of seismic waves whose dominant frequencies typically range from 1 to 5 Hz. Harmonic tremor and spasmodic bursts (also called spasmodic tremor) are specific variants of more general volcanic tremor. However, harmonic bursts have a relatively uniform signal, whereas spasmodic bursts have a higher frequency, pulsating, irregular signal.

Volcanic tremor, including harmonic tremor, may persist for minutes to days or longer, may lack a distinct beginning or end, frequently precedes and almost always accompanies eruptions, and was the most consistent short-term indicator of impending eruptions in a study of 200 calderas worldwide (McNutt, 2000) (see also  Volcanoes and...

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Bibliography

  1. Chouet, B., 1988. Resonance of a fluid-driven crack: radiation properties and implications for the source of long-period events and harmonic tremor. Journal of Geophysical Research, 93, 4375–4400.CrossRefGoogle Scholar
  2. Hellweg, M., 2000. Physical models for the source of Lascar’s harmonic tremor. Journal of Volcanology and Geothermal Research, 101, 183–198.CrossRefGoogle Scholar
  3. Jolly, A. D., Sherburn, S., Jousset, P., and Kilgour, G., 2010. Eruption source processes derived from seismic and acoustic observations of the 25 September 2007 Ruapehu eruption – North Island, New Zealand. Journal of Volcanology and Geothermal Research, 191, 33–45.CrossRefGoogle Scholar
  4. Julian, B. R., 1994. Volcanic tremor: nonlinear excitation by fluid flow. Journal of Geophysical Research, 99, 11859–11877.CrossRefGoogle Scholar
  5. Leet, R. C., 1988. Saturated and subcooled hydrothermal boiling in groundwater flow channels as a source of harmonic tremor. Journal of Geophysical Research, 93, 4835–4849.CrossRefGoogle Scholar
  6. Lesage, P., Mora, M. M., Alvarado, G. E., Pacheco, J., and Métaxian, J.-P., 2006. Complex behavior and source model of the tremor at Arenal volcano, Costa Rica. Journal of Volcanology and Geothermal Research, 157, 49–59.CrossRefGoogle Scholar
  7. Maryanto, S., et al., 2008. Constraints on the source mechanism of harmonic tremors based on seismological, ground deformation, and visual observations at Sakurajima volcano, Japan. Journal of Volcanology and Geothermal Research, 170, 198–217.CrossRefGoogle Scholar
  8. McNutt, S. R., 2000. Seismic monitoring. In Sigurdsson, H. (ed.),Encyclopedia of Volcanoes. San Diego: Academic Press, pp. 1095–1119.Google Scholar
  9. Nishi, Y., Sherburn, S., Scott, B. J., and Sugihara, M., 1996. High-frequency earthquakes at White Island volcano, New Zealand: insights into the shallow structure of a volcano-hydrothermal system. Journal of Volcanology and Geothermal Research, 72, 183–197.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Geological Survey of CanadaNatural Resources Canada, Geological Survey of CanadaVancouverCanada