Has Mount St. Helens Awakened?
Sept. 28, 2004
(CBS/AP)
Small earthquakes rattled Mount St. Helens at the rate of one or two a minute Monday, and seismologists were working to determine the significance of some of the most intense seismic activity in nearly 20 years.
Nervous scientists fear the slumbering giant, which hasn't had any kind of eruption in 18 years, may have awakened.
"Things could change rapidly or continue on like this for weeks," seismologist Steve Malone of the University of Washington told CBS News.
Early tests of gas samples collected above the volcano by helicopter Monday did not show unusually high levels of carbon dioxide or sulfur.
"This tells us that we are probably not yet seeing magma moving up in the system," said Jeff Wynn, chief scientist with the U.S. Geological Survey in Vancouver, Wash. He noted additional tests are necessary to better define whether there's magma moving under the mountain's crater.
Scientists are trying to figure out what is going on beneath the 925-foot-high dome of hardened lava within the mountain's gaping crater. They want to know whether the quakes are the result of water seeping into the mountain or magma.
In either case, they'll continue to watch the volcano ? which erupted to devastating effect in 1980 ? from the Cascade Volcano Observatory in Vancouver, about 50 miles away. Additional flights are also planned but not yet scheduled, Wynn said.
A helicopter carried scientists and instruments over the crater Monday to assess the gases and ground deformation that would indicate pressure building below the dome.
Measurements of ground movement "will tell us whether there's any new magma coming into the system," said Seth Moran, a seismologist at the observatory. That data will not be immediately available.
Swarms of small earthquakes began Thursday and increased in frequency and magnitude until Sunday, when there were more than 10 events with a magnitude of 2 to 2.8. The quakes are at depths less than one mile below the lava dome.
By Monday, the pace was unchanged and the magnitude range had narrowed to between 0.5 and 2-plus, Wynn said.
"Since this morning, the energy releases have been slowly but steadily ramping up," he said. "We don't know what that means. ... That kind of energy hasn't been seen since 1986," when the mountain's last lava-dome-building eruption occurred.
Moran said there was potential for explosions within the crater that could throw rocks as far as the rim.
The USGS issued a notice of volcanic unrest on Sunday, citing "an increased likelihood of a hazardous event." U.S. Forest Service officials closed hiking trails above the tree line at 4,800 feet on the 8,364-foot mountain, though the visitor's center and most other trails at the Mount St. Helens National Monument remained open.
"Oh my God, we were just went through there twice!" hiker Monica Williams said.
St. Helens' May 18, 1980, eruption killed 57 people, leveled hundreds of square miles of forests and dumped volcanic ash across the Northwest.
Sunday's activity was the most in a 24-hour period since the 1986 eruption, said survey geologist Willie Scott. Earthquake swarms in 1998 and 2001 did not result in any surface activity.
If there is an explosion, Scott said concern would be focused within the crater and on the upper flanks of the volcano. A five-mile area, primarily north of the volcano, could receive flows of mud and rock debris.
On Monday, a helicopter lowered a geophysicist onto the lava dome to replace a failed instrument used to measure tiny movements that indicate whether the dome is swelling, Wynn said.
While the chopper was near the dome, the pilot was in radio contact with Bobbie Myers, another geophysicist who during the 1980 blast learned to detect subtle changes in seismic monitors.
"She's known to be able to predict explosive events up to a couple of minutes ahead of time," Wynn said.
Mt. St. Helens isn't the only restless volcano, reports CBS News Correspondent Sandra Hughes: In Alaska, Mount Spurr is getting so hot that an ice cauldron has formed in the summit. In Hawaii , both Mauna Loa and Kilauea have become more active. And in California, Mammoth Mountain, a popular ski town built directly on top of an underground caldron, has shown signs of life with killer gases that scorched trees.
All of these volcanoes are located on the so-called "Ring Of Fire" that circles from North America to Asia.
"They are related in plate tectonics in a sort of way, and the stresses on the earth, but they don't talk to each other, and one is not dependent on the other," said Malone.
At any given time, at least 20 volcanoes are erupting somewhere in the world.
Is Mt. St. Helens Ready to Blow Again??
by Gretchen956 12 Replies latest social current
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Gretchen956
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Sentinel
Hi Gretchen,
I was drawn to your post, because I just learned there was a significant earthquake in central California this morning. I've been thinking too, that with all the hurricane activities abounding this season, we should probably be on the watch for erupting volcanos and more earthquakes. When the earth is moving and changing in one area, it usually does affect an opposite side area.
Thanks, I enjoyed reading the information you posted.
/<
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Gretchen956
Good point, Sentinel, I hadn't thought of it from that aspect.
Sherry
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TonyT
See?!!!!
Volcanoes, hurricanes, earthquakes, a millionaire football player quitting because he would rather smoke pot...
Isn't it obvious to any reasonable person that we are in the last days?
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truthseeker1
And they say pot has no ill effects.....Sheash!
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Mulan
It's doing all the same things it did back in Feb. and March of 1980. And then it blew on May 18, the same year, so we are kind of expecting it. It's unlikely it will be such a massive explosion this time, because the top of the mountain is gone, but you never know.
I agree,,,,,,,,,,,,,,,,"signs of the times". Hahahhaha.
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JeffT
We were in Pullman when it blew in 1980. We'd just gotten out of the Sunday meeting and wife and I were thinking of taking the kids on a picnic. We scrapped that plan becuase of an ugly black cloud on the horizon. Got home and found out about the eruption. It is really creepy when the emergecy broadcast tone comes on the TV and somebody starts out "This is not a drill..." By five it was pitch black and everybody was inside because we didn't know if it was toxic. We ended up with eight tons of ash per acre. Things were pretty well screwed up for a couple of weeks.
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seven006
I remember the ash falling like snow and completely covering my lawn. I went out and tried to make an ash man. The ash doesn't stick together like snow does. Ash angels were a bit of a bitch to make also.
Dave
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LittleToe
So we're gonna have an ash-man contest at the Fest???
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xjw_b12
Volcanoes, hurricanes, earthquakes, a millionaire football player quitting because he would rather smoke pot...
Isn't it obvious to any reasonable person that we are in the last days?
You forgot to mention the NHL Players strike.
xjw_b12 suffering from his own personal Armegeddon