A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, 3,000 kilometers (1,900 mi) deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide past one another.
Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool the Earth's troposphere. Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines.
This isn't purely an Earth science question, but I don't know where else to post it. Recently, the Kasatochi volcano erupted in Alaska. It brought to mind something that happened to me a long time ago that I have always wondered about.
In 1989 I was flying from Alaska to Seattle. Days...
Apparantly, an incredibly intense electrical storm develloped during the eruption, giving some spectacular light effects during the night
http://www.nuestroclima.com/blog/?p=1003
So there is that wide spread layer of Volcanic ash, known as the Laacher Sea Tephra which is widely used as a dating marker but how old is it, itself?
All with 95% confidence interval:
K-Ar dating gives: 12,900 +/- 560 years before present
A carbon date of the last tree ring of an ash...
Time to wing in a female virgin, or at least a PF sister that hasn't gotten lucky for a while. :rolleyes: Astronuc is a volcano-hound, so he'll probably volunteer to oversee the ceremony. Mexico City should have pleasant weather this time of year...
Edit: Removed URL to image - rotating...
http://www.indiadaily.com/editorial/17965.asp
A supervolcano hidden in a veritable mega-volcano nursery called the Eduardo Avaroa Caldera Complex, located in the inhospitable Puna-Altiplano region near the tri-section of Argentina, Bolivia, and Chile is a major focus of many volcano experts...
Ok, I've been working on this for awhile and I can't seem to understand how to work it out. ANY insight would be greatly appreciated!
The problem: An erupting volcano (2.5 km tall) projects a boulder from a vent at an angle of 40 degrees to the horizontal direction. The rock lands 6.0 km away...
is it true that there are more greenhouse gasses released from a single Volcanic eruption than all of the gasses produced by man since the industrial revolution?
If so, shouldn't that silence the global-warming advocates?
During volcanic eruptions, chunks of solid rock can be blasted out of the volcano; these projectiles are called volcanic bombs. At what initial speed would a bomb have to be ejected, at angle 35* to the horizontal, from the vent at A in order to fall at the foot of the volcano at B, at vertical...
A volcano fills the volume between the graphs z=0 and \frac{1}{(x^2+y^2)^3}, and outside the cylinder x^2+y^2=1
so I found the z height to be from 0 to 1, the radius from 1 to infinity, and theta to be from 0 to 2pi
\int_0 ^{2 \pi} \int_1 ^{\inf}\int _0 ^ {1} r dzdrd \theta
I know that...
Does anyone have any idea about when it might erupt again?
I'd like to be prepared since the magma chamber of this thing will prolly wipe out the entire earth.
Iwo Jima and Japan lie along the western edge of the Pacific Ring of Fire (ROF). During the last 18 months, the seismic and volcanic activity seems to have increased, and along with the Sumatran tsunamis and a few big quakes off North and South America, one has to wonder its all related.
See...