Featured Research

from universities, journals, and other organizations

Even Without An Eruption, Soft Spots On Volcanoes Can Trigger Deadly Mudflows, UB Scientists Find

Date:
December 16, 1999
Source:
University At Buffalo
Summary:
Just because a volcano isn't erupting doesn't mean it poses no danger. In papers presented at the annual meeting of the American Geophysical Union, University at Buffalo volcanologists show how, in some cases, soft spots on volcanoes that simply collapse from the side may trigger mudflows that potentially can be more devastating than eruptions.

SAN FRANCISCO -- Just because a volcano isn't erupting doesn't mean it poses no danger.

Related Articles


In papers being presented today (Tuesday, Dec. 14) at the annual meeting of the American Geophysical Union, University at Buffalo volcanologists show how, in some cases, soft spots on volcanoes that simply collapse from the side may trigger mudflows that potentially can be more devastating than eruptions.

"This is the frightening part about it. These volcanoes don't even have to erupt. They just sit there and a part of it comes roaring off," said Michael F. Sheridan, Ph.D., professor of geology and lead researcher.

"Our findings show us that we have to pay more attention to these older volcanoes that have been sitting around for awhile, sort of stewing in their own juices," said Sheridan.

He explained that as these hydrothermal fluids circulate, they change the structure of the rocks and minerals, softening the volcanoes and making them more vulnerable to collapse.

"That explains why so many volcanoes are usually kind of craggy and steep near the top," he said. "They get that way when soft parts slump or a big slab breaks off, leaving a cliff face."

Sheridan said this new realization about the dangers that volcanic mudflows present to populations is particularly relevant because more towns are being built on volcanic slopes. And that is the case not just in Mexico and other countries known for their volcanoes, but in the U.S. as well.

"Avalanches and mudflows could be a big issue for Mt. Rainier in Washington for example," he said. "There's a lot of pressure in the Seattle and Tacoma areas to start new developments that extend right up into the mountains, but people are building subdivisions in areas that, in the not too distant past, were overcome by mudflows. People are not willing to accept the concept that this is a really dangerous area."

Sheridan said he and his colleagues are applying to volcanoes concepts about hydrothermal alteration that were developed in the 1970s for the purposes of exploration for economically important mineral deposits. Alteration zones and weaknesses in rock structures were targeted then as places to search for these minerals.

Now these weak areas, which UB researchers are pinpointing using satellite data, are turning out to be red flags that could be the source of mudflows so deadly they can travel as far as 80 miles from a source and are capable of wiping out whole towns and villages.

Sometimes, when a piece of a volcano comes loose, an avalanche is triggered.

"Avalanches in themselves can be disastrous," Sheridan noted, "but they don't travel nearly as far as mudflows and they are confined to relatively steep slopes, whereas a mudflow will go for miles. This is where the real danger lies; if you have a really tall volcano and all that energy is driving a mudflow, it could be devastating."

Dangerous mudflows develop when clay is present in the material derived from the volcano's slopes. UB researchers use spectrometers mounted in aircraft or satellites to collect data about the volcano's surface that will help to pinpoint soft spots. This data is interpreted to outline hazard zones for potential mudflows or lahars.

So far, Sheridan and his team have uncovered alarming soft spots on Pico Orizaba, the highest mountain in Mexico, and have mapped areas of potential mudflows at Colima, Mexico's most active volcano.

"That data is going to surprise a lot of people," said Sheridan. "When we started our work on Pico, we were told by geologists in Mexico who had studied the volcano that we would not find any soft spots there, that there simply wasn't any alteration there. In the end, we found alteration everywhere."

While Vera Cruz, the nearest large city with a population of 2 million, is not in danger, Sheridan said that other cities that are closer to the volcano, with populations of around 150,000 or 200,000, are threatened.

The conclusions of this research stem in part from the UB scientists' visit to Nicaragua last fall after torrential rainfall from Hurricane Mitch triggered devastating mudflows that killed about 1,600 people.

"Nicaragua was a real eye-opener," said Sheridan. "There was such a small catchment basin where the rain accumulated, but because the conditions were favorable for this kind of event, a massive, tragic mudflow resulted. These areas are at extremely high risk if people are living nearby," he said.

The research is being funded by the National Aeronautical and Space Administration.


Story Source:

The above story is based on materials provided by University At Buffalo. Note: Materials may be edited for content and length.


Cite This Page:

University At Buffalo. "Even Without An Eruption, Soft Spots On Volcanoes Can Trigger Deadly Mudflows, UB Scientists Find." ScienceDaily. ScienceDaily, 16 December 1999. <www.sciencedaily.com/releases/1999/12/991216080524.htm>.
University At Buffalo. (1999, December 16). Even Without An Eruption, Soft Spots On Volcanoes Can Trigger Deadly Mudflows, UB Scientists Find. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/1999/12/991216080524.htm
University At Buffalo. "Even Without An Eruption, Soft Spots On Volcanoes Can Trigger Deadly Mudflows, UB Scientists Find." ScienceDaily. www.sciencedaily.com/releases/1999/12/991216080524.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Keurig Co-Founder Says Company Has A Waste Problem

Keurig Co-Founder Says Company Has A Waste Problem

Newsy (Mar. 5, 2015) — Keurig co-founder John Sylvan told The Atlantic he doesn&apos;t even own a Keurig because they&apos;re too expensive and produce too much waste. Video provided by Newsy
Powered by NewsLook.com
Raw: Tourists Visit Rare Grey Whales in Mexico

Raw: Tourists Visit Rare Grey Whales in Mexico

AP (Mar. 4, 2015) — Once nearly extinct, grey whales now migrate in their thousands to Mexico&apos;s Vizcaino reserve in Baja California, in search of warmer waters to mate and give birth. Tourists flock to the reserve to see the whales, measuring up to 49 feet long. (March 4) Video provided by AP
Powered by NewsLook.com
Raw: Injured Miners Treated After Blast

Raw: Injured Miners Treated After Blast

AP (Mar. 4, 2015) — An explosion ripped through a coal mine before dawn Wednesday in war-torn eastern Ukraine, killing at least one miner, officials said. Graphic video of injured miners being treated in a Donetsk hospital. (March 4) Video provided by AP
Powered by NewsLook.com
Australian Museum Shares Terrifying Goblin Shark With the World

Australian Museum Shares Terrifying Goblin Shark With the World

Buzz60 (Mar. 4, 2015) — The Australian Museum has taken in its fourth-ever goblin shark, a rare fish with an electricity-sensing snout and &apos;alien-like&apos; jaw. Mike Janela (@mikejanela) takes a look. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins