The largest eruptions in Earth's history
Data(s) |
01/07/2011
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Resumo |
Large igneous provinces (LIPs) host the most frequently recurring, largest volume basaltic & silicic eruptions on Earth. The largest volume (>1000 km^3 DRE) and magnitude (>M8) eruptions produce areally extensive (10^4-10^5 km^2) basaltic flow fields and sills, and silicic ignimbrites that are the main LIP building blocks. Basaltic and silicic eruptions have comparable magnitudes, but silicic ignimbrite volumes may be significantly underestimated due to unrecognized and correlated, but voluminous co-ignimbrite ash deposits. Magma composition is no barrier to individual eruption volume. Despite similar magnitudes, flood basaltic and silicic eruptions are very different in eruption mechanism, duration, intensity, vent configuration, and emplacement style. Flood basalts are dominantly effusive Hawaiian-Strombolian, with magma discharge rates of ~10^7-10^8 kg s^-1, and produce dominantly compound pahoehoe flow fields over eruption durations most likely >10 yrs. Most silicic eruptions are moderately to highly explosive, producing cocurrent pyroclastic fountains (rarely Plinian) and suggested to be of short-duration (hours to days) and high intensity (~10^11 kg s^-1). Eruption frequencies are elevated for largemagnitude eruptions of both magma types during LIP formation. In basalt-dominated provinces, large magnitude (>M8) eruptions have much shorter recurrence intervals (10^3-10^4 years) than similar magnitude silicic eruptions (~10^5 years). The huge volumes of magma erupted rapidly in LIPs raises several unresolved issues in terms of locus of magma generation and storage (if any) in the crust prior to eruption, the paths and rates of ascent from magma reservoirs to the surface, and relative aerosol contributions to the stratosphere from the flood basaltic and rhyolitic eruptions. |
Formato |
application/pdf |
Identificador | |
Relação |
http://eprints.qut.edu.au/58558/1/81106015_BRYAN03351.pdf http://www.iugg2011.com/abstracts/abstracts.html Bryan, Scott Edward, Ukstins Peate, Ingrid, Self, Stephen, Peate, David W., Jerram, Dougal A., Mawby, Michael R., Marsh, J.S. (Goonie), & Miller, Jodie (2011) The largest eruptions in Earth's history. In 25th IUGG General Assembly, 28 June - 7 July 2011, Melbourne, NSW. |
Direitos |
Copyright 2011 [please consult the author] |
Fonte |
School of Earth, Environmental & Biological Sciences; Science & Engineering Faculty |
Palavras-Chave | #040314 #040304 #040303 |
Tipo |
Conference Paper |