Super Volcanoes

Tom Pering

Super Volcanoes

1Todays topicsWhat is a super eruption?Where do super eruptions occur?What do super volcanoes look like?Super Volcanoes around the world.Yellowstone Caldera ChainYellowstone NowWhat would an eruption at Yellowstone be like to live through?What are the chances of an eruption occurring in our lifetime?

What is a super eruption?You may know about super eruptions under the term supervolcano.Definition of a super eruptionVEI 8 Ultra-Plinian, Mega-Colossal3Lord Byron - DarknessI had a dream, which was not all a dream.The bright sun was extinguished, and the starsDid wander darkling in the eternal space,Rayless, and pathless, and the icy earthSwung blind and blackening in the moonless air;Morn came and went -and came, and brought no day

Plate Boundaries

Hot SpotsMantle Plume

Huge Magma Chambers

Where do super eruptions occur?5What do super volcanoes look like?Caldera Volcanoes

Well known super volcanoesYellowstone, USALake Toba, INDONESIATaupo, NEW ZEALANDNot so well known super volcanoesLa Garita Caldera, USACerro Galn, ARGENTINAGlen Coe, SCOTLANDScafells, Lake District, ENGLAND Who can name a super volcano7Glen Coe, ScotlandLast eruption 420 million years agoSilurian (Paleozoic Era)5 eruptionsRoughly 500,000 years apart.Glaciations8Scafells, Lake District, England440 520 million years ago (unknown last eruption)Ordovician (Paleozoic Era)Largest known phreatomagmatic eruption VEI 7 or 8?Glaciations

9Lake Toba, Indonesia74,000 years agoLargest Volcanic Lake in worldMankind survivedGlobal volcanic winter10

Taupo, New ZealandFirst Eruption 300,000 years agoOruanui Eruption26,500 years agoLots of volcanic activity nearbySlightly smaller than Taupo, one of the biggest eruptions in the past 250,000 years just behind Toba12

La Garita Caldera, USAColorado26 million years agoLargest known eruption5000 km

Minimum of 14 calderas, large one, fish canyon tuff, 14

80km long and 40km wide15Cerro Galn, ArgentinaAndes Mountain Range2.2 million years ago1050 kmMinimum of 14 calderas, large one, fish canyon tuff, 16

Yellowstone Caldera Chain

Put in a photo of the Yellowstone caldera chain18Yellowstone EruptionsHuckleberry Ridge Caldera, 2.1 million years ago2450 km Mesa Falls, 1.3 million years ago280 kmLava Creek, 640,000 years ago1000 km

Source: USGS

Yellowstone

Yellowstone NowNational Park - over 3 million visitors a year.307 million people in the USAAn eruption at Yellowstone could be a small outflow of lava or an VEI 8 eruption. Large Magma Chamber

Warning signs of an imminent eruptionHigh ground temperaturesIncreased volcanic gas emissionHydrothermal feature activity increaseGround upliftHydrothermal explosionsEarthquakes

Harmonic tremors

Bison deaths22

Possible regional effects of an eruption at YellowstoneZone 1 Pyroclastic Zone (Around 90,000 could be killed 90% mortality rate)100 km radiusZone 2 and 3 Asphyxiation and Roof Collapse 3 million people trapped by ashZone 4Ashfall 15cmZone 5Ashfall 5cm Zone 6Ashfall 1cm

Pyroclastic flows occur when the pressure holding the eruption column in the air dips, causing ash to fall out of the column. Very fast, can reach up to 1000km/h, high temp of volcanic gas and ash, zone 1 could be up to 100km from yellowstone or 10,000km2 of land.

Greatest danger is anyone within 1000km of the volcano. (ash above 15cm, loading on roofs, collapse and crush.

Food source gone, air transport halted for whole of US24Different ways to dieDirect AsphyxiationGas PoisoningPyroclastic FlowsRoof CollapseBurningLaharsPlane Crash

Indirect Starvation / DroughtFreezeRiots / Conflict

What could be the global effects of an eruption at Yellowstone?Water Contamination

Food Shortages

Increase Rainfall

Economic Failure

Extinction

Volcanic Winter

Triggering of an Ice AgeAsh particles can trigger rainfall, can turn ash on ground into flows laharsDeath by ash 500,0001783, Laki eruption (fissure eruption), lava spewed for 7 months, fluorosis death. Eruption released flourine, deformities in bones killing or crippling. Yellowstone could release this into the atmosphere, and transport around the world.Real risk comes from sulphur dioxide (sulphuric acid (transformation occurs) gets into stratosphere can stay their for years, deflecting sunlight away from the earth.

Evidence Ice Cores. Biggest signal evidence super eruption in Toba. 2000 million tonnes of aerosols.

Using this data for yellowstone 3 weeks to spread completely across the globe. 2 3 years snow all year round. 26

What are the chances of a super eruption occurring in our lifetimes?Are we overdue?

Further Readinghttp://www.yellowstonenationalpark.com/calderas.htmYellowstone Volcano ObservatoryUSGS

ReferencesBrenchley, P.J., Rawson, P.F., 1990? The Geology of England and Wales. The Geological Society. Bath. 256ppCIA World Fact book [Online]Cole, J.W., Milner, D.M., Spinks, K.D., 2005. Calderas and caldera structures: a review. Earth Science Reviews. 69, pp. 1-26Grotzinger, J., Jordan, T.H., Press, F., Siever, R., 2006. Understanding Earth. W.H.Freeman. Basingstoke. Moore, I., Kokelaar, P., 1998. Tectonically controlled piecemeal caldera collapse: A case study of Glencoe volcano, Scotland. Geological Society of America Bulletin. 110 (11), pp. 1448-1466Riciptu, L.R., Johnson, C.M., Sawyer, D.A., Lipman, P.W., 1995. Crustal and magmatic evolution in a large multicyclic caldera complex. Journal of Volcanology and Geothermal Research. 67, pp. 1 28Wilson, C.J.N., 2001. The 26.5ka oruanui eruption, New Zealand: an introduction and overview. Journal of Volcanology and Geothermal Research. 112, pp. 133 - 174