IMAG STS Beisa screen shot

We are checking our databases, but it appears that if you want to have a really massive explosion, your best chance is to be

an arc volcano. Arc volcanoes come in three types of groups: oceanic arcs, continental arcs and hybrids. An oceanic arc forms

where two tectonic plates meet underwater. Some of the better known oceanic arcs are the Philippines, Tonga, the Kermadec islands,

the Sunda Arc (starting with the Andaman and Nicobar islands and curving southeast through Sumatra), the Solomons and

the Mascarenes (the islands like Reunion and Mauritius east of Madagascar). Usually there is a deepwater trench that parallels the

arc. Continental arcs form where two tectonic plates meet on land. The most famous continental arc is the Andes. There is a similar

structure starting at Panama and running 1500 km north through central America. A third example is the Cascadian arc. Its southern

portion starts at Mt. Lassen in California and includes twenty major volcanoes as it continues northward past Mount Rainier near

Seattle to Silverthorne caldera in British Columbia. A hybrid arc occurs when the two plates transition - examples are the Aleutian arc

which runs from Mt. Douglas, Mt. Griggs and Novarupta at the northern end of the Alaska Peninsula through Cold Bay caldera at the

southern end of the peninsula out through the Aleutian islands to Kiska at the extreme west. A similar example is the Kurile-Kamchatka

arc which runs from Hokkaido in northern Japan northward through the Kuriles and further north in the Kamchatka peninsula.

Non-arc volcanoes like Mauna Loa in Hawaii and Mt. Etna in Sicily erupt at reasonably constant rates but with little explosive force.

That means it is rare for non-arc volcanoes to eject sulfur into the stratosphere. Sulfur dioxide and other gases that only reach the

lower troposphere tend to be removed by rains quickly. Stratospheric clouds of sulfur and other gases can linger for years.