Encyclopedia of Earthquake Engineering

Living Edition
| Editors: Michael Beer, Ioannis A. Kougioumtzoglou, Edoardo Patelli, Ivan Siu-Kui Au

Earthquake Swarms

  • Josef HorálekEmail author
  • Tomáš Fischer
  • Páll Einarsson
  • Steinunn S. Jakobsdótir
Living reference work entry
DOI: http://doi.org/10.1007/978-3-642-36197-5_294-1



Earthquake swarms are a specific type of seismicity. They are generally defined as sequences of seismic events closely clustered in space and time, without a single outstanding earthquake (Mogi 1963). Globally, most seismic energy is released in ordinary earthquakes, represented by a single strong event succeeded by a series of smaller aftershocks (in some cases also preceded by foreshocks) with magnitudes of one or more magnitude units lower than that of the main event. These are so-called mainshock-aftershock sequences. In contrast, an earthquake swarm consists of numerous, mostly shallow, earthquakes, which are missing a single large event. They produce few dominant earthquakes of similar magnitudes so that smaller events are not associated with any...

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We are grateful to both anonymous reviewers for their valuable suggestions, which helped us to improve the paper substantially. Most of the work was accomplished within the Grant Project P210–12–2336 of the Grant Agency of the Czech Republic “Earthquake swarms and their triggering mechanisms and driving forces in diverse tectonic environments (Bohemian Massif, Mid-Atlantic ridge, French Alps).”


  1. Cappa F, Rutqvist J, Yamamoto K (2009) Modeling crustal deformation and rupture processes related to upwelling of deep CO2-rich fluids during the 1965–1967 Matsushiro earthquake swarm in Japan. J Geophys Res 114, B10304. doi:10.1029/2009JB006398
  2. Chouet B (1996) Long-period volcano seismicity: its sources and use in eruption forecasting. Nature 380:309–316
  3. Daniel G, Prono E, Renard F, Thouvenot F, Hainzl S, Marsan D, Helmstetter A, Traversa P, Got JL, Jenatton L, Guiguet R (2011) Changes in effective stress during the 2003–2004 Ubaye seismic swarm, France. J Geophys Res 116, B01309. doi:10.1029/2010JB007551
  4. Einarsson P (1986) Seismicity along the eastern margin of the North American Plate. In: Vogt PR, Tucholke BE (eds) The Western North Atlantic region, vol M, The Geology of North America. Geological Society of America, Boulder, pp 99–116
  5. Farrel J, Husen S, Smith RB (2009) Earthquake swarm and b-value characterization of the Yellowstone volcano-tectonic system. J Volcanol Geotherm Res 188(1–3):260–276
  6. Fischer T, Horálek J (2005) Slip-generated patterns of swarm microearthquakes from West Bohemia/Vogtland (central Europe): evidence of their triggering mechanism? J Geophys Res 110:B05S21. doi:10.1029/2004JB003363
  7. Fischer T, Horálek J, Hrubcová P, Vavryčuk V, Bräuer K, Kämpf H (2014) Intra-continental earthquake swarms in West-Bohemia and Vogtland: a review. Tectonophysics 611:1–27. doi:10.1016/j.tecto.2013.11.001
  8. Foulger GR, Julian BR, Hill DP, Pitt AM, Malin P, Shalev E (2004) Non-double-couple microearthquakes at Long Valley caldera, California, provide evidence for hydraulic fracturing. J Volcanol Geotherm Res 132:45–71
  9. Godano M, Larroque C, Bertrand E, Courboulex F, Deschamps A, Salichon J, Blaud-Guerry C, Fourteau L, Charléty J, Deshayes P (2013) The October–November 2010 earthquake swarm near Sampeyre (Piedmont region, Italy): a complex multicluster sequence. Tectonophysics 608:97–111. doi:10.1016/j.tecto.2013.10.010
  10. Hainzl S (2004) Seismicity pattern of earthquake swarms due to fluid intrusion and stress triggering. Geophys J Int 159:1090–1096. doi:10.1111/j.1365-246X.2004.02463.x
  11. Hainzl S, Fischer T, Dahm T (2012) Seismicity-based estimation of the driving fluid pressure in the case of swarm activity in Western Bohemia. Geophys J Int 191:271–281. doi:10.1111/j.1365-246X.2012.05610.x
  12. Hill DP (1977) A model for earthquake swarms. J Geophys Res 82(8):1347–1352
  13. Hill DP, Langbein JO, Prejean S (2003) Relations between seismicity and deformation during unrest in Long Valley Caldera, California, from 1995 through 1999. J Volcanol Geotherm Res 127(3–4):175–193
  14. Holtkamp SG, Brudzinski MR (2011) Earthquake swarms in circum-Pacific subduction zones. Earth Planet Sci Lett 305:215–225
  15. Horálek J, Šílený J (2013) Source mechanisms of the 2000 earthquake swarm in the West Bohemia/Vogtland region (Central Europe). Geophys J Int 194:979–999. doi:10.1093/gji/ggt295
  16. Horálek J, Šílený J, Fischer T (2002) Moment tensors of the January 1997 earthquake swarm in West Bohemia (Czech Republic): double-couple vs. non-double-couple events. Tectonophysics 356:65–85
  17. Hurst AW, McGinty PJ (1999) Earthquake swarms to the west of Mt Ruapehu preceding its 1995 eruption. J Volcanol Geotherm Res 90:19–28
  18. Ibáñez JM, De Angelis S, Díaz-Moreno A, Hernández P, Alguacil G, Posada A, Pérez N (2012) Insights into the 2011–2012 submarine eruption off the coast of El Hierro (Canary Islands, Spain) from statistical analyses of earthquake activity. Geophys J Int 191:659–670. doi:10.1111/j.1365-6X.2012.05629.x
  19. Ibs-von Seht M, Plenefisch T, Klinge K (2008) Earthquake swarms in continental rifts – a comparison of selected cases in America, Africa and Europe. Tectonophysics 452:66–77
  20. Jenatton L, Guiguet R, Thouvenot F, Daix N (2007) The 16,000-event 2003–2004 earthquake swarm in Ubaye (French Alps). J Geophys Res 112, B11304. doi:10.1029/2006JB004878
  21. Julian BR, Miller AD, Foulgler GR (1997) Non-double-couple earthquake mechanisms at the Hengill-Grensdalur volcanic complex, Southwest Iceland. Geophys Res Lett 24:743–746
  22. Kato A, Sakai S, Iidaka T, Iwasaki T, Hirata N (2010) Non-volcanic seismic swarms triggered by circulating fluids and pressure fluctuations above a solidified diorite intrusion. Geophys Res Lett 37, L15302. doi:10.1029/2010GL043887
  23. Kraft T, Wassermann J, Schmedes E, Igel H (2006) Meteorological triggering of earthquake swarms at Mt. Hochstaufen, SE-Germany. Tectonophysics 424:245–258
  24. Lay T, Wallace TC (1995) Modern global seismology. Academic Press, Inc. San Diego
  25. Lin G, Shearer PM (2009) Evidence for waterfilled cracks in earthquake source regions. Geophys Res Lett 36, L17315. doi:10.1029/2009GL039098
  26. Massin F, Farrell J, Smith RB (2013) Repeating earthquakes in the Yellowstone volcanic field: implications for rupture dynamics, ground deformation, and migration in earthquake swarms. J Volcanol Geotherm Res 257:159–173
  27. Minson SE, Dreger DS, Bürgmann R, Kanamori H, Larson KM (2007) Seismically and geodetically determined nondouble-couple source mechanisms from the 2000 Miyakejima volcanic earthquake swarm. J Geophys Res 112, B10308. doi:10.1029/2006JB004847
  28. Mogi K (1963) Some discussion on aftershocks, foreshocks and earthquake swarms – the fracture of semi-infinite body caused by an inner stress origin and its relation to the earthquake phenomena. Bull Earthquake Res Inst 41:615–658
  29. Ogata Y (1988) Statistical models for earthquake occurrences and residual analysis for point processes. J Am Stat Assoc 83:9–27
  30. Pedersen R, Sigmundsson F, Einarsson P (2007) Controlling factors on earthquake swarms associated with magmatic intrusions; constraints from Iceland. J Volcanol Geotherm Res 162:73–80
  31. Scholz CH (2002) The mechanics of earthquakes and faulting. Cambridge University Press, Cambridge
  32. Shapiro SA, Huenges E, Borm G (1997) Estimating the crust permeability from fluidinjection-induced seismic emission at the KTB site. Geophys J Int 131:F15–F18
  33. Shelly DR, Hill DP (2011) Migrating swarms of brittle-failure earthquakes in the lower crust beneath Mammoth Mountain, California. Geophys Res Lett 38, L20307. doi:10.1029/2011GL049336
  34. Sigmundsson F, Hooper A, Hreinsdóttir S, Vogfjörd KS, Ófeigsson BG, Heimisson ER, Dumont S, Parks M, Spaans K, Guðmundsson GB, Drouin V, Árnadóttir T, Jónsdóttir K, Gudmundsson MT, Högnadóttir T, Fridriksdóttir HM, Hensch M, Einarsson P, Magnússon E, Samsonov S, Brandsdóttir B, White RS, Ágústsdóttir T, Greenfield T, Green RG, Hjartardóttir ÁR, Pedersen R, Bennett RA, Geirsson H, La Femina PC, Björnsson H, Pálsson F, Sturkell E, Been CJ, Möllhoff M, Braiden AK, Eibl EPS (2015) Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system, Iceland. Nature 517:191–195. doi:10.1038/nature14111
  35. Stroujkova A, Malin PE (2002) Moment-tensor statistics of the 1997 Long Valley microearthquake swarm. J Seismol 6:69–85
  36. Templeton DC, Dreger DS (2006) Non-double-couple earthquakes in the Long Valley volcanic region. Bull Seimol Soc Am 96:69–79
  37. Thouvenot F, Jenatton L, Gratier J-P (2009) 200-m-deep earthquake swarm in Tricastin (lower Rhone Valley, France) accounts for noisy seismicity over past centuries. Terra Nova 21(3):203–210
  38. Vavryčuk V (2001) Inversion for parameters of tensile earthquakes. J Geophys Res 106(B8):16339–16355. doi:10.1029/2001JB000372
  39. Vavryčuk V (2011) Tensile earthquakes: theory, modeling, and inversion. J Geophys Res 116(B12), B12320. doi:10.1029/2011JB008770
  40. Vidale JE, Shearer PM (2006) A survey of 71 earthquake bursts across southern California: exploring the role of pore fluid pressure fluctuations and aseismic slip as drivers. J Geophys Res 111, B05312. doi:10.1029/2005JB004034
  41. Wright TJ, Sigmundsson F, Ayele A, Belachew M, Brandsdottir B, Calais E, Ebinger C, Einarsson P, Hamling I, Keir D, Lewi E, Pagli C, Pedersen R (2012) Geophysical constraints on the dynamics of spreading centres from rifting episodes on land. Nat Geosci. doi:10.1038/NGEO1428
  42. Yamashita T (1999) Pore creation due to fault slip in a fluid-permeated fault zone and its effect on seismicity: generation mechanism of earthquake swarm. Pure Appl Geophys 155:625–647
  43. Yukutake Y, Ito H, Honda R, Harada M, Tanada T, Yoshida A (2011) Fluid-induced swarm earthquake sequence revealed by precisely determined hypocenters and focal mechanisms in the 2009 activity at Hakone volcano, Japan. J Geophys Res 116, B04308. doi:10.1029/2010jb008036

Copyright information

© Springer-Verlag Berlin Heidelberg 2021

Authors and Affiliations

  • Josef Horálek
    • 1
    Email author
  • Tomáš Fischer
    • 2
  • Páll Einarsson
    • 3
  • Steinunn S. Jakobsdótir
    • 3
  1. 1.Institute of GeophysicsAcademy of Sciences of the Czech RepublicPragueCzech Republic
  2. 2.Faculty of ScienceCharles University in PraguePragueCzech Republic
  3. 3.Faculty of Earth ScienceUniversity of IcelandReykjavíkIceland