Jump to content

Recommended Posts

  • Replies 5
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Posted
Can ya post the text? Registration is required.

 

Here ya go, Ralph:

 

Biggest ash blast yet at St. Helens

 

12:56 PM PDT on Tuesday, October 5, 2004

 

From KING, NWCN Staff Reports and the Associated Press

 

MOUNT ST. HELENS NATIONAL MONUMENT, Wash. - Mount St. Helens sent up what appeared to be the biggest blast of ash yet Tuesday morning since the mountain began its most recent period of restlessness.

 

Scientists nevertheless said Tuesday's venting was still not the biggest event to be expected and won't be likely be the last of its kind.

 

"Mount St. Helens has begun a period of eruptive activity. It may last weeks. it may last months. I think people need to get used to the concept," said USGS volcanologist Jake Lowenstern.

 

Lowenstern said it appeared the the ash and steam now were coming from multiple vents inside the crater, which now contains some ponded and boiling water.

 

The prevailing winds of between 20 mph and up to 40 mph were expected to carry the ash in the direction of the Yakima Valley, Wenatchee and Cle Elum but would not arrive for about four to six hours, according to weather forecasters.

 

The plume rose to an estimated elevation of about 13,000 feet and the National Weather Service issued an ashfall advisory for the south Washington Cascades.

 

In Randall, Wash. about 21 miles from St. Helens, residents reported the ash as a thin cloud moving overhead about an hour after the Tuesday blast.

 

As Tuesday dawned, scientists were paying close attention to a large area of swelling on the mountain the previous 24 hours, a growth of 150 feet in an area covering about 150 football fields on the southern side of the lava dome.

 

By noon, SkyKING aerials showed the uplifted area even bigger than before with a large area of ponded muck inside what has been the most active and violent vent so far.

 

The 600-foot-deep glacier behind the dome, and one of the few advancing glaciers in the country, is now one of the many shades of gray that make up the inside of the crater.

 

Scientists speculate the pressure pushing up the dome could be from magma, volcanic gases or a combination of both. The volcano's large steam emissions came from the area of swelling.

 

"When you get that kind of deformation at that rate, plus with this high and tense seismicity, it does seem to indicate that something is imminent, something will happen fairly soon," said USGS scientist Jon Major. "But there's still a chance that this could all quiet back down, so at this point it's still a little bit of a guessing game as exactly when and what is going to happen."

 

USGS scientists also discovered Monday an increase in sulfur dioxide, hydrogen sulfide and carbon dioxide, gases associated with magma, inside the crater. Small earthquakes within the 2.0 to 3.0 magnitude range occurring three to four times a minute continued to rumble the volcano Tuesday morning, but subsided again after the Tuesday eruption.

 

Scientists continue to monitor the volcano and hope to gather more data from two new GPS system devices air dropped into the crater Monday.

 

As Mount St. Helens continues to vent steam and ash, communities in Washington and Oregon are readying contingency plans. That includes making sure emergency vehicles will be able to operate even under heavy ash fall.

 

Clark, Skamania and Cowlitz counties will coordinate local road closures and cleanup and are prepared for possible health effects that might impact local hospitals and possible disruption to electrical service.

 

Emergency officials say residents near the mountain can prepare by having 72 hours' worth of supplies, including canned and dry food and drinking water, on hand.

 

The mountain’s alert was raised over the weekend to Level 3, the highest possible, meaning an eruption is imminent. Some volcano experts had said an explosion would probably happen over the weekend. But as the time passed, others cautioned Monday that volcanic activity is difficult to predict.

 

“Right now, we’re thinking it’s about a 70 percent chance that it will erupt and a 30 percent chance that it just might go back to sleep,” Pierson told NBC’s “Today” show Monday.

 

Pierson said a buildup of earthquakes since a plume of steam was released on Friday indicate that pressure is still mounting within the volcano. Geological Survey crews also observed a shift in the crater floor and on part of the 1,000-foot lava dome that essentially serves as a plug for magma, he said.

 

“Cracks are opening up so we know something is pushing up close to the surface right now,” Pierson said.

 

Scientists have also detected elevated levels of carbon dioxide and other volcanic gases, including the rotten egg smell of hydrogen sulfide, that reflect changes in the volume of magma rising within the mountain.

Posted

Thanks, Paul.

 

My landlord, in a display of solidarity with the ash-stricken, is having my building's brick walls tuckpointed over the next few weeks. There's cement dust flying everywhere, covering the walls, yard, and basement in a fine layer of gray. It's the next best thing to living downwind!

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...