Irenaeus, Siteadmin, Check users, oversight, Administrators
351,381
edits
Changes
Jump to navigation
Jump to search
Line 7:
Line 7: + + + + + + + + + +
→External links
As tephra falls to the ground with increasing distance from a volcano, the average size of the individual rock particles becomes smaller and thickness of the resulting deposit becomes thinner. Small tephra stays aloft in the eruption cloud for longer periods of time, which allows wind to blow tiny particles farther from an erupting volcano.<ref>http://volcanoes.usgs.gov/Products/Pglossary/tephra.html</ref>
As tephra falls to the ground with increasing distance from a volcano, the average size of the individual rock particles becomes smaller and thickness of the resulting deposit becomes thinner. Small tephra stays aloft in the eruption cloud for longer periods of time, which allows wind to blow tiny particles farther from an erupting volcano.<ref>http://volcanoes.usgs.gov/Products/Pglossary/tephra.html</ref>
== Supervolcano ==
[[File:375px-Long Valley Caldera cross section.svg.png|thumbnail|200px|right|Cross-section through Long Valley Caldera. The valley is one of the Earth's largest [[caldera]]s.]]
''See also:'' [[Supervolcano]]
According to the website Internet Feolography:
{{Cquote|A [[supervolcano]] is any [[volcano]] capable of producing a volcanic eruption with an ejecta volume greater than 1,000 km3 (240 cu mi). This is thousands of times larger than normal volcanic eruptions. Supervolcanoes are on a much bigger scale than other volcanoes. Unlike composite volcanoes, with their steep sides, they are difficult to spot. They are typically depresssions in the ground. The calderas are so large they can be seen from space. They have been identified in [[Indonesia]], in [[New Zealand]], in [[South America]] and an extinct one in [[Glen Coe]] in the [[UK]].
Supervolcanoes can occur when magma in the mantle rises into the crust from a hotspot but is unable to break through the crust, and pressure builds in a large and growing magma pool until the crust is unable to contain the pressure (this is the case for the [[Yellowstone]] [[Caldera]]).<ref>[http://www.geography.learnontheinternet.co.uk/topics/whatisasupervolcano.html What is a supervolcano?]</ref>}}
==External links==
==External links==