Geology notes september 22

Geology notes - Lava fountains no more than a couple hundred feet in the air*Can flow at high speeds(30mph-The volcano Explosivity Index(VEI ranks

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Geology Exam 40 multiple choice and 10 matching (answers can be used for than once) -Volcanic eruptions -Volcanic eruptions are driven by escaping volatiles “Soda Pop” theory of eruption -Eruption type is related to magma composition *Andesite are the most dangerous (Pelean, Plinian, and Vulcanian) *Basalt eruptions are not that dangerous (Icelandic, Hawaiian, and Strombolian) -Plinian eruptions are produced by boiling magma where the bubbles burst to make glassy fragments of volcanic ash. *Plinian eruptions can eject volcanic ash and volatiles into the sstratosphere *Most dangerous, driven by Felsic magma and are water rich. *Pyroclastic flows are a mixture of very hot volcanic ash and gas that t flow down the flank of a volcano. -Vulcanian and Strombolian eruptions are a mixture of lava flows and ejected cinders and bombs.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
*basalt magma *scoria (cinders) -Hawaiian and Icelandic eruptions produce basalt lava flows
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: * Lava fountains, no more than a couple hundred feet in the air *Can flow at high speeds (30mph)-The volcano Explosivity Index (VEI) ranks volcanoes by the amount of magma erupted *0-2 very small chambers, not very dangerous eruptions, basalt eruptions *7-8 very dangerous, Felsic eruptions (andesite and rhyolite) *VEI is related water content and viscosity, which are controlled by magma composition *VEI and eruption type correlate to magma composition, magma chamber depth, and time between eruptions -Calderas form when very large magma chambers empty and collapse *EX. Crater Lake, Oregon *Yellowstone National Park is an excellent example of a collapsed caldera *3 cycles of Yellowstone eruptions began 2.2 million years ago and ended 600,000 years ago. Magma is still present below the park at 15 km depth *The Yellowstone caldera continues to show tectonic and hydrothermal activity...
View Full Document

This note was uploaded on 08/09/2011 for the course GEOS 1004 at Virginia Tech.

Page1 / 3

Geology notes - Lava fountains no more than a couple hundred feet in the air*Can flow at high speeds(30mph-The volcano Explosivity Index(VEI ranks

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online