Tom Pering

“Super Volcanoes”

Today’s topics…What 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 eruption

VEI 8 – Ultra-Plinian, Mega-Colossal

Lord Byron - Darkness

“I 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?

What do super volcanoes look like?Caldera Volcanoes

Well known “super volcanoes”Yellowstone, USALake Toba, INDONESIATaupo, NEW ZEALAND

Not so well known “super volcanoes”La Garita Caldera, USACerro Galán, ARGENTINAGlen Coe, SCOTLANDScafells, Lake District, ENGLAND

Glen Coe, ScotlandLast eruption 420 million years agoSilurian (Paleozoic Era)5 eruptionsRoughly 500,000 years apart.Glaciations

Scafells, Lake District, England440 – 520 million years ago (unknown last

eruption)Ordovician (Paleozoic Era)Largest known phreatomagmatic eruption VEI 7 or 8?Glaciations

Lake Toba, Indonesia74,000 years agoLargest Volcanic Lake in worldMankind survived

Taupo, New ZealandFirst Eruption – 300,000 years agoOruanui Eruption

26,500 years ago

Lots of volcanic activity nearby

La Garita Caldera, USAColorado26 million years ago

Largest known eruption5000 km³

Cerro Galán, ArgentinaAndes Mountain Range2.2 million years ago1050 km³

Yellowstone Caldera Chain

Yellowstone EruptionsHuckleberry Ridge Caldera, 2.1 million

years ago2450 km³

Mesa Falls, 1.3 million years ago280 km³

Lava Creek, 640,000 years ago1000 km³

• 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

Possible regional effects of an eruption at YellowstoneZone 1 – Pyroclastic Zone (Around 90,000

could be killed – 90% mortality rate)100 km radius

Zone 2 and 3 – Asphyxiation and Roof Collapse 3 million people trapped by ash

Zone 4Ashfall – 15cm

Zone 5Ashfall – 5cm

Zone 6Ashfall – 1cm

Different ways to die…Direct

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 Age

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

Further Readinghttp://www.yellowstonenationalpark.com/ca

lderas.htmYellowstone Volcano ObservatoryUSGS

References Brenchley, P.J., Rawson, P.F., 1990? The Geology of England and

Wales. The Geological Society. Bath. 256pp CIA 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. 1-26 Grotzinger, 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. 1448-1466

Riciptu, 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 – 28

Wilson, 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