Volcanoes Many People Make the Assumption That

Volcanoes Many people make the assumption that the most severe damage done by volcanoes results from the hot lava that flows from some volcanoes. For example, the lava that flows from Hawaiian volcanoes -- called "Hawaiian volcanism" -- are quite striking and make incredibly beautiful yet dangerous-looking videos and still photos. But that volcanic eruption is not nearly as hazardous as the eruption from a volcano like Mount St. Helens.

This paper discusses the most dangerous volcano eruptions, and it also references certain side effects from some volcanoes that most people aren't aware of. Volcanic Hazards When Mount St. Helens exploded on May 18, 1980, there was no red hot lava flowing down from the top of the mountain. But there was an enormously powerful blast that permanently altered the landscape. This kind of explosive blast from a volcano is considered to be the most violent.

An article in Life Science online magazine reports that the explosion removed the upper 1,300 feet of the top of the mountain. The way in which Mount St. Helens erupted is the kind of hazard that is most damaging.

The article by Mary Bagley explains that scientists that were flying around the volcano noted that the "…whole north face of the mountain was on the move," and as they passed to the east side of the mountain, "the north face collapsed, releasing superheated gases and trapped magma in a massive lateral explosion." The scientists in the plan had to put the plane into a very steep dive just to be going fast enough to "outrun the cloud of incandescent gas" (Bagley).

This, again, is the most hazardous kind of volcanic eruption. In fact, once the pressure that had been building up in the volcano was released -- very abruptly -- a "nuees ardentes" was created, which is a "glowing cloud of superheated gas and rock debris" which moved at "supersonic speeds" (Bagley). How much damage was done? Everything within eight miles of the mountain "was wiped out almost instantly," Bagley writes. The shockwave leveled old trees in the forest up to 19 miles away.

An estimated 540 million tons of ask was released as a cloud reached 12 miles in the air. Another direct hazard from Mount St. Helens was created when the tremendous heat produced by the eruption melted the ice and snow on the mountain and a sea of hot mud, moving at about 90 miles per hour, roared down the mountain and swept away "everything in its path" (Bagley).

Indirect Hazards from Volcanoes While direct hazards include blasts that flatten forests and hot mud flows that wipe out everything in its path, there are indirect hazards as well that are associated with volcanoes. In the case of Mount St. Helens, the soot and smoke in the air was damaging to public health, and the flattening of the forests was damaging to the ecology on which recreationalists depend.

In the Laki, Island volcano, which erupted in 1783, the indirect hazards included: "drought, famine, and gas poisoning, which killed 9,350 people" and thousands of heads of livestock (www.n-d-a.org). In the Tambora volcano in Indonesia (1815), the indirect hazards from that blast included tsunamis, famine, disease and starvation" (www.n-d-a-.org). Moreover, crops failed in Indonesia and due to.