My OperaPetit spots - New Type of Volcano?
Thursday, August 10, 2006 3:46:44 PM
A series of mysterious eruptions in the western Pacific could be caused by a new type of volcano, a new study suggests.
Three processes are responsible for the formation of volcanoes on Earth, according to theories:
* The planet's tectonic plates can move away from each other, allowing magma to seep up (at divergent plate boundaries).
* The plates can also move towards each other, forcing eruptions (at convergent plate boundaries).
* Plumes of magma well up from deep inside the Earth (at hotspots).
In the July 27 issue of Science Express (and not yet in the journal Science as reported at livescience), researchers report the discovery of tiny active volcanoes on the Pacific Plate that aren't caused by any of these mechanisms.
These small volcanoes may be widespread on ocean floors where the mantle just under the crust is squeezed out by tectonic forces when one plate moves under another.
The possibility of this type of volcanism had been proposed in the past, but had never been adequately documented.
Dubbed "petit spots" (in contrast to “hot spots”), these new types of volcanoes are difficult to spot using satellite technology.
http://www.livescience.com/forcesofnature/060728_petit_spot.html
Sciencexpress
See also http://whatonearth.olehnielsen.dk/volcanoes.asp#setting
Some people believe by the way that “it is not global warming that's causing the oceans to heat, it's heated oceans that are warming the globe and setting up a scenario that includes among its consequences more and increasingly violent hurricanes, tornadoes and blizzards.” And “what is heating the seas is underwater tectonic activity such as submerged volcanic eruptions and other problems causing red hot magma to seep up through cracks in the ocean floor, heating the water around them.” I would like, however, to stress that these processes have been going on continuously for billions of years, although admittedly not always with the same pace.
Three processes are responsible for the formation of volcanoes on Earth, according to theories:
* The planet's tectonic plates can move away from each other, allowing magma to seep up (at divergent plate boundaries).
* The plates can also move towards each other, forcing eruptions (at convergent plate boundaries).
* Plumes of magma well up from deep inside the Earth (at hotspots).
In the July 27 issue of Science Express (and not yet in the journal Science as reported at livescience), researchers report the discovery of tiny active volcanoes on the Pacific Plate that aren't caused by any of these mechanisms.
These small volcanoes may be widespread on ocean floors where the mantle just under the crust is squeezed out by tectonic forces when one plate moves under another.
The possibility of this type of volcanism had been proposed in the past, but had never been adequately documented.
Dubbed "petit spots" (in contrast to “hot spots”), these new types of volcanoes are difficult to spot using satellite technology.
http://www.livescience.com/forcesofnature/060728_petit_spot.html
Sciencexpress
See also http://whatonearth.olehnielsen.dk/volcanoes.asp#setting
Some people believe by the way that “it is not global warming that's causing the oceans to heat, it's heated oceans that are warming the globe and setting up a scenario that includes among its consequences more and increasingly violent hurricanes, tornadoes and blizzards.” And “what is heating the seas is underwater tectonic activity such as submerged volcanic eruptions and other problems causing red hot magma to seep up through cracks in the ocean floor, heating the water around them.” I would like, however, to stress that these processes have been going on continuously for billions of years, although admittedly not always with the same pace.
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