WCM Forum - Yellowstone

oh lassts doch bitte dir kirche im dorf....

http://volcanoes.usgs.gov/yvo/2005/docudrama.html

Zitat:

QUESTION: What is the chance of another catastrophic volcanic eruption at Yellowstone?
ANSWER: Although it is possible, scientists are not convinced that there will ever be another catastrophic eruption at Yellowstone. Given Yellowstone's past history, the yearly probability of another caldera—forming eruption could be calculated as 1 in 730,000 or 0.00014%. However, this number is based simply on averaging the two intervals between the three major past eruptions at Yellowstone — this is hardly enough to make a critical judgement. This probability is roughly similar to that of a large (1 kilometer) asteroid hitting the Earth. Moreover, catastrophic geologic events are neither regular nor predictable.

QUESTION: What would happen if a "supervolcano" eruption occurred again at Yellowstone?
ANSWER: Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate. The surrounding states of Montana, Idaho, and Wyoming would be affected, as well as other places in the United States and the world. Such eruptions usually form calderas, broad volcanic depressions created as the ground surface collapses as a result of withdrawal of partially molten rock (magma) below. Fortunately, the chances of this sort of eruption at Yellowstone are exceedingly small in the next few thousands of years.

QUESTION: Do scientists know if a catastrophic eruption is currently imminent at Yellowstone?
ANSWER: There is no evidence that a catastrophic eruption at Yellowstone is imminent, and such events are unlikely to occur in the next few centuries. Scientists have also found no indication of an imminent smaller eruption of lava.

QUESTION: Could the Yellowstone volcano have an eruption that is not catastrophic?
ANSWER: Yes. Over the past 640,000 years since the last giant eruption at Yellowstone, approximately 80 relatively nonexplosive eruptions have occurred and produced primarily lava flows. This would be the most likely kind of future eruption. If such an event were to occur today, there would be much disruption of activities in Yellowstone National Park, but in all likelihood few lives would be threatened. The most recent volcanic eruption at Yellowstone, a lava flow on the Pitchstone Plateau, occurred 70,000 years ago.

und hier auch noch was zum nachlesen: http://pubs.usgs.gov/fs/2005/3024/

lg
cin