PDA

View Full Version : Yellowstone Rated High for Eruption Threat



Jolie Rouge
05-09-2005, 11:22 AM
Yellowstone Rated High for Eruption Threat



YELLOWSTONE NATIONAL PARK, Wyo. (AP) - The Yellowstone caldera has been classified a high threat for volcanic eruption, according to a report from the U.S. Geological Survey.

Yellowstone ranks 21st most dangerous of the 169 volcano centers in the United States, according to the Geological Survey's first-ever comprehensive review of the nation's volcanoes.

Kilauea in Hawaii received the highest overall threat score followed by Mount St. Helens and Mount Rainer in Washington, Mount Hood in Oregon and Mount Shasta in California.

Kilauea has been erupting since 1983. Mount St. Helens, which erupted catastrophically in 1980, began venting again in 2004.


Those volcanoes fall within the very high threat group, which includes 18 systems. Yellowstone is classified with 36 others as high threat.


Recurring earthquake swarms, swelling and falling ground, and changes in hydrothermal features are cited in the report as evidence of unrest at Yellowstone.


The report calls for better monitoring of the 55 volcanoes in the very high and high threat categories to track seismic activity, ground bulging, gas emissions and hydrologic changes.


University of Utah geology professor Robert Smith, who monitors earthquakes and volcanic activity in Yellowstone, said more real-time monitoring should be helpful.


``We've really been stressing over the last couple of years that the USGS should consider hazards as a very high priority in their future,'' he said. ``We need to get the public's confidence and the perception that we're doing it right.''


The university has joined the Geological Survey and Yellowstone National Park in creating the Yellowstone Volcano Observatory, which uses ground-based instruments throughout the region and satellite data to monitor volcanic and earthquake unrest in the world's first national park.


The USGS report recognizes Yellowstone as an unusual hazard because of the millions of people who visit the park and walk amid features created by North America's largest volcanic system, Smith said, a status he has been advocating for years.


Smith does not paint the devastating picture portrayed in a recent TV docudrama but said smaller threats exist. For example, a lower-scale hydrothermal blast could scald tourists strolling along boardwalks.


Emissions of toxic gases from the park's geothermal features also pose a threat. Five bison dropped dead last year after inhaling poisonous gases trapped near the ground due to cold, calm weather near Norris Geyser Basin.


Stepped up monitoring and a new 24-hour watch office could lead to more timely warnings and help avoid human catastrophes at Yellowstone and nationally, according to the USGS.


Forty-five eruptions, including 15 cases of notable volcanic unrest, have been documented at 33 volcanoes in the U.S. since 1980, according to the report, released April 29.

http://cnn.netscape.cnn.com/ns/news/story.jsp?floc=ne-main-9-l8&flok=FF-APO-1501&idq=/ff/story/0001%2F20050509%2F1502634898.htm&sc=1501


On the Net:


U.S. Geological Survey: http://www.usgs.gov


Volcano Threat Report: http://pubs.usgs.gov/of/2005/1164


Yellowstone Volcano Observatory: http://volcanoes.usgs.gov/yvo/index.html



05/09/05 15:02

sivohdarba
05-11-2005, 03:19 AM
I watched the "docudrama" and it scared the beejeebies out of me! I am kind of relieved that they don't agree with it...I was starting to think I should prepare for it's eruption like I did for Y2k :o

llbriteyes
05-11-2005, 06:58 AM
The threat is still there, though.

Linda



I watched the "docudrama" and it scared the beejeebies out of me! I am kind of relieved that they don't agree with it...I was starting to think I should prepare for it's eruption like I did for Y2k :o

dotcomgirl
05-12-2005, 02:40 PM
this is quite scarey since I live in Montana . I watched the docudrama about it also. Other than the eruption Yellowstone park is spectacular.

Jolie Rouge
01-14-2008, 10:29 PM
Tsunami linked to Yellowstone crater
Mon Jan 14, 4:53 PM ET

YELLOWSTONE NATIONAL PARK, Wyo. - Tsunami-like waves created by an earthquake may have triggered the world's largest known hydrothermal explosion some 13,000 years ago, a federal scientist says.

The explosion created the Mary Bay crater that stretches more than one mile across along the north edge of Yellowstone Lake. Debris from the explosion has been found miles away.

Lisa Morgan of the U.S. Geological Survey told a gathering of scientists over the weekend at Mammoth Hot Springs that an earthquake may have displaced more than 77 million cubic feet of water in Yellowstone Lake, creating huge waves that essentially unsealed a capped geothermal system.

Though much has been made in recent years of a possible eruption of Yellowstone's "super volcano," geologists studying the park have long said that the likelihood is greater for a large hydrothermal explosion.

Morgan said that over the last 14,000 years there have been 20 hydrothermal explosions in Yellowstone that mostly left craters bigger than football fields. They resulted in well-known Yellowstone landmarks such as Mary Bay, Turbid Lake and Indian Pond, all near the north edge of Yellowstone Lake.

The explosions happen when hot water just below the surface flashes into steam and breaks through the surface.

Smaller explosions in Yellowstone happen about once every two years but rarely when people are around or in danger, according to a 2007 hazard assessment produced by USGS.

In 1989, an explosion at Porkchop geyser at Norris Geyser Basin sent rocks and debris flying more than 200 feet.

But geologists are still trying to better understand the larger explosions that happen about once every 700 years in Yellowstone and have left behind the biggest hydrothermal explosion craters in the world.

At Mary Bay, Morgan said she thinks there were at least two big waves before the explosion. Evidence of those waves has been found more than 3 miles north of the lake's edge, she said.

The explosion's column may have reached more than a mile in the air and spread debris across some 18 square miles, she said.

"You would not want to be here when this occurred," Morgan said.

Predicting if or when another will happen remains difficult but it's worthy of continued study, scientists involved with Yellowstone's geology said.

"It's something we should take notice of," Morgan said.

http://news.yahoo.com/s/ap/20080114/ap_on_sc/yellowstone_hydrothermal_explosions;_ylt=AutoGf1zF BCw_bQ3ZNhwRpms0NUE