Climate change as a driver of volcano lateral collapse [Bill McGuire]
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Climate change as a driver of volcano lateral collapse [Bill McGuire]

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Climate change as a driver of volcano lateral collapse. Presented by Bill McGuire at the "Perth II: Global Change and the World's Mountains" conference in Perth, Scotland in September 2010.

Climate change as a driver of volcano lateral collapse. Presented by Bill McGuire at the "Perth II: Global Change and the World's Mountains" conference in Perth, Scotland in September 2010.

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    Climate change as a driver of volcano lateral collapse [Bill McGuire] Climate change as a driver of volcano lateral collapse [Bill McGuire] Presentation Transcript

    • Climate change as a driverof volcano lateral collapseBill McGuire1 & Rachel Lowe21Aon Benfield UCL Hazard Research Centre,University College London2Exeter Climate Systems, University of Exeter The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • Talk structure• Volcano lateral collapse• A volcanic response to climate change• The COLLAPSE database• Temporal variations in the lateral collapse record• Climate influences and collapse mechanisms• Future prospects Eyjafjallajökull (Iceland) April 2010 The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • Volcano lateral collapse• Failure of volcanic edifice Mount St Helens leading to debris avalanche• Common, transitory feature of lifecycles of long-lived volcanoes of all types• Frequency: ~ 20 a century over last 500 years• 20% of ca 1500 active Holocene volcanoes show evidence of collapse Hawaii• Occur at all scales up to > Hawaii 1000km3• Collapse velocities typically > 40ms-1• May be eruption-related• Significant hazard The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • Factors affecting volcano stability COLLAPSE TRIGGERS Seismic ground acceleration Pore-water pressurization The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • A Geospheric response to climatechange • Periods of dynamic climate change elicit response from Geosphere – Increased seismicity – Elevated levels of submarine landslide formation • Volcanic response – High latitude ice caps (Iceland) – Globally Phil Trans. R. Soc. A., 368, 2010 The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • The volcanic response• Ice unloading at high • latitudes (e.g. Iceland) – Volcanic activity > x10 more frequent that current during early post-glacial times – Mantle melt production increased x30 Vatnajökull• Global response – ice-core record – Ice melt; increased ppn; sea-level rise – Volcano lateral collapse contribution? Mount St Helens (1980) The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • Sea-level rise as a driver? Increased volcanism EruptionReduced compressive Maximum shear stress onstress seaward flank Lateral collapse Pumping action Increased compressive stress Frequency of significant Mediterranean eruptions between 15 and 8 thousand y BP = The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003with time averaged 1,050 y 350 y compared
    • The COLLAPSE database 480 Quaternary collapse events at 316 volcanoes The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • Spatial distribution of collapses The information contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • Temporal distribution of lateral collapses The temporal distributionof lateral collapse events in the Quaternary North Pole The temporal distribution of lateral collapse events with volume 80 C-14 limit 10000 60 1000 100 40 10 Volume ( km3) 20 1 Latitude Issues: preservation & dating 0.1 0 100 collapse events recognised in last 500y 0.01 - sample is a very small fraction of total 0.001 -20 0.00011000000 900000 800000 700000 600000 500000 400000 300000 200000 100000 0 -40 Age (years BP) -60 -801800 1600 1400 1200 1000 800 600 400 200 0 South Pole Age (ka BP) The information contained in this document is strictly proprietary and confidential Lateral Collapse Events ©Benfield Hazard Research Centre 2003
    • Filtered collapse record and collapse rates The temporal distribution of lateral collapse events by region 20 90 18 Collapses > 40 ka and < 2 ka and volumes < 1km3 filtered out 80 16 70 Distance from Equator (°N /°S) Collapse rate (per 1000 years) 14 60 12 50 10 Rate of lateral collapse event in the marine and continental environment 40 8 14 30 6 12 29 percent collapse at island volcanoes 20 4 42 percent within 250km of coastCollapse rate per 1000 years 10 2 10 8 0 0 Equator 6 40 35 30 25 20 15 10 5 0 Age (ka BP) 4 Africa Austalasia Canary Islands Central America and the Caribbean Europe Hawaaiian Isalnds 2 Indian Ocean Southeast Asia Japan 0 North America Russia South America 40 38 36 34 Global collapse26 24 100020 18 32 30 28 rate per 22 years 16 14 12 10 8 6 4 2 0 The information contained in this document is strictly proprietary and confidential Age (ka BP) Marine Environment Continental Environment ©Benfield Hazard Research Centre 2003
    • Pattern of collapse minima The temporal distribution of lateral collapse events by region 20 90 18 80 16 70 Distance from Equator (°N /°S)Collapse rate (per 1000 years) 14 60 12 50 10 40 8 30 6 20 4 2 10 0 0 Equator 40 35 30 25 20 15 10 5 0 Age (ka BP) Africa Austalasia Canary Islands Central America and the Caribbean Europe Hawaaiian Isalnds Indian Ocean LGM Heinrich Y.Dryas 8.2 ka Cold, dry Southeast Asia Japan North America Russia South America Global collapse rate per 1000 years The information event intervals H1 contained in this document is strictly proprietary and confidential ©Benfield Hazard Research Centre 2003
    • A working hypothesis• No obvious link with absolute sea-level or rate of rise• Incidence of collapse increases following end of colder/drier episodes – Debuttressing effect of ice mass loss – Meltwater production and increased precipitation • Raised water tables – Increased potential for magma-water interaction at shallow depths – Pore-water pressurization by magma provides potential trigger The information contained in this document is strictly proprietary and confidential P. Trans. R. Soc. A., 368, 2559-2577. 2010 ©Benfield Hazard Research Centre 2003
    • Future candidates for collapse?Ritter Island (PNG) 1888 Pico do Fogo (Cape Verde) The information contained in this document is strictly proprietary and confidentialStromboli (Italy) 2002 Cumbre Vieja (La Palma) ©Benfield Hazard Research Centre 2003