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Super Volcanoes
By: Joe Staloch
Jenny Koester
¾What is a super volcano?
ƒ the term super volcano is not scientific, it is a
media based term
ƒ a super volcano would be extremely large,
produce large calderas, and have global
affects.
¾How do super volcanoes form?
1. super volcanoes, more specifically caldera
forming volcanoes, form when magma pools
in country rock.
2. After a small pool is created, the mafic
magma assimilates the country rock, which
is felsic, this assimilation of country rock
forms rhyolitic magma.
3. Rhyolitic magma is more viscous and so
gases build up in the magma creating
tremendous pressure.
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How do super volcanoes form?
4. When the pressure becomes to much for the country
rock to withstand, it fractures.
5. The pressure of the magma is released so violently that
debris is expelled so high into the atmosphere that
global climate changes are almost inevitable, and ash
fall results hundreds or even thousands of miles away.
6. After the magma chamber has been drained by the
massive expulsion, the ground remaining above the
empty chamber sinks down along fracture points formed
by the eruption
¾What is the difference between super
volcanoes and other volcanoes?
ƒ explosiveness
ƒ huge calderas
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Examples of Super Volcanoes
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Long Valley, eastern California
Toba, Indonesia
Taupo, New Zealand
Yellowstone Caldera, Yellowstone
National Park
The World’s Volcanoes
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Comparative Eruptive Volumes
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Yellowstone, a sleeping giant?
• the Yellowstone hotspot, has left a trail of
15-20 calderas as the North American
plate moves southwest over the hotspot, in
the past 16 million years
• three calderas have been formed in the
Yellowstone in the past 2 million years
Trail of past calderas
Map of Yellowstone Calderas
1. Oldest
Yellowstone
caldera- 2 mya
2. 1.3 mya
Yellowstone
caldera
3. 630,000 year
old Yellowstone
caldera
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3 Cataclysmic Events
• 1st eruption
– first caldera forming event occurred 2.1 million
years ago
– this eruption was 2,500 times larger than the
1980 eruption of Mt. St. Helens
– the caldera formed by this eruption was
bigger than the state of Rhode Island
– produced Huckleberry Ridge tuff, 500 – 2500
foot thick sheet of volcanic rock
Ash Fall
Map of Yellowstone Calderas
1. Oldest
Yellowstone
caldera- 2 mya
2. 1.3 mya
Yellowstone
caldera
3. 630,000 year
old Yellowstone
caldera
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• 2nd eruption
– after the 1st eruption, the volcanic activity
moved into the island park area in Idaho.
– 1.3 million years ago
– this eruption was 280 times larger than the
1980 eruption of Mt. St. Helens
– created Island Park caldera
– Mesa Falls tuff 500 feet thick
Ash Fall
Map of Yellowstone Calderas
1. Oldest
Yellowstone
caldera- 2 mya
2. 1.3 mya
Yellowstone
caldera
3. 630,000 year
old Yellowstone
caldera
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• 3rd eruption
– this eruption occurred within the park 650,000
years ago
– this eruption was 1,000 larger than the 1980
Mt. St. Helens eruption
– formed a caldera 50 mi. by 30 mi.
– Lava Creek tuff in some places is 1600 feet
thick
– the topography of Yellowstone Plateau is the
flat bottom of the caldera
Ash Fall
Why is Yellowstone so active?
• It lies on top of a hot spot!!!
• this hotspot is different from most because
it is under continental crust which resists
volcanism, so when magma finally breaks
through, it is a devastating event
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Earth’s Hotspots
Will it Erupt Again?
YES!!!
When?
• scientists have determined, Yellowstone
Volcano erupts every 600,000 years, it has
been 640,000 years since the last eruption
• scientists predict an eruption in the next
100,000 years
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