Caldera

For other uses, see Caldera (disambiguation).

Mount Mazama's eruption timeline, an example of caldera formation

A caldera (/kɔːlˈdɛrə, kæl-/[1] kawl-DERR-ə, kal-) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the structural integrity of such a chamber, greatly diminishing its capacity to support its own roof, and any substrate or rock resting above. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter).[2] Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur over the course of a century, the formation of a caldera is a rare event, occurring only a few times within a given window of 100 years.[3] Only eight caldera-forming collapses are known to have occurred between 1911 and 2018,[3] with a caldera collapse at Kīlauea, Hawaii in 2018.[4] Volcanoes that have formed a caldera are sometimes described as "caldera volcanoes".[5]

  1. ^ "caldera". Dictionary.com Unabridged (Online). n.d.
  2. ^ Troll, V. R.; Walter, T. R.; Schmincke, H.-U. (1 February 2002). "Cyclic caldera collapse: Piston or piecemeal subsidence? Field and experimental evidence". Geology. 30 (2): 135–38. Bibcode:2002Geo....30..135T. doi:10.1130/0091-7613(2002)030<0135:CCCPOP>2.0.CO;2. ISSN 0091-7613.
  3. ^ a b Gudmundsson, Magnús T.; Jónsdóttir, Kristín; Hooper, Andrew; Holohan, Eoghan P.; Halldórsson, Sæmundur A.; Ófeigsson, Benedikt G.; Cesca, Simone; Vogfjörd, Kristín S.; Sigmundsson, Freysteinn; Högnadóttir, Thórdís; Einarsson, Páll; Sigmarsson, Olgeir; Jarosch, Alexander H.; Jónasson, Kristján; Magnússon, Eyjólfur; Hreinsdóttir, Sigrún; Bagnardi, Marco; Parks, Michelle M.; Hjörleifsdóttir, Vala; Pálsson, Finnur; Walter, Thomas R.; Schöpfer, Martin P. J.; Heimann, Sebastian; Reynolds, Hannah I.; Dumont, Stéphanie; Bali, Eniko; Gudfinnsson, Gudmundur H.; Dahm, Torsten; Roberts, Matthew J.; Hensch, Martin; Belart, Joaquín M. C.; Spaans, Karsten; Jakobsson, Sigurdur; Gudmundsson, Gunnar B.; Fridriksdóttir, Hildur M.; Drouin, Vincent; Dürig, Tobias; Aðalgeirsdóttir, Guðfinna; Riishuus, Morten S.; Pedersen, Gro B. M.; van Boeckel, Tayo; Oddsson, Björn; Pfeffer, Melissa A.; Barsotti, Sara; Bergsson, Baldur; Donovan, Amy; Burton, Mike R.; Aiuppa, Alessandro (15 July 2016). "Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow" (PDF). Science. 353 (6296): aaf8988. doi:10.1126/science.aaf8988. hdl:10447/227125. PMID 27418515. S2CID 206650214. Archived (PDF) from the original on 24 July 2018.
  4. ^ Shelly, D.R.; Thelen, W.A. (2019). "Anatomy of a Caldera Collapse: Kīlauea 2018 Summit Seismicity Sequence in High Resolution". Geophysical Research Letters. 46 (24): 14395–14403. Bibcode:2019GeoRL..4614395S. doi:10.1029/2019GL085636. S2CID 214287960.
  5. ^ Druitt, T. H.; Costa, F.; Deloule, E.; Dungan, M.; Scaillet, B. (2012). "Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano". Nature. 482 (7383): 77–80. Bibcode:2012Natur.482...77D. doi:10.1038/nature10706. hdl:10220/7536. ISSN 0028-0836. PMID 22297973.