The water is rising 10 - 12 inches an hour. They can't wait forever. The pressure behind the debris dam will grow anyway and cause a larger problem when it does break down. The debris dam might be accessible from the side of the structure without risking lives to blow a hole in it.
If there are people still alive the rescuers have to have a chance to find them and they can't do it underwater. USGS might be able to estimate how stable the rest of the hillside is, too.
Geologic map of the Snohomish Quadrangle, Snohomish County, Washington (click here)
I thought it looked like sand. (click here) These are old glacial deposits. It is mixed some iron, but, when sand gets dry and then fills up with water again, there is bound to be trouble.
The Sheriff is asking residents in Oso and Arlington to evacuate. Lake Stevens is in the lower right corner of this image, and those towns are further north. They are in the next Quadrangle north of the Snohomish Quadrangle.
If there are people still alive the rescuers have to have a chance to find them and they can't do it underwater. USGS might be able to estimate how stable the rest of the hillside is, too.
Geologic map of the Snohomish Quadrangle, Snohomish County, Washington (click here)
I thought it looked like sand. (click here) These are old glacial deposits. It is mixed some iron, but, when sand gets dry and then fills up with water again, there is bound to be trouble.
Rescuers to search through the night for mudslide survivors in Washington state after hearing cries for help (click here)
March 22, 2014, 10:52 p.m.
Rescuers searching a Washington (click here) state community
devastated by a deadly mudslide said Saturday night that they had heard
signs of life coming from the debris and would continue searching even
as the danger of flooding rose.
“We’ll be here all night long doing what we can to rescue people,” Snohomish County Sheriff Ty Trenary said.
Trenary, speaking at a televised news conference, did
not specify what kinds of sounds had been detected. He said the search
had been made difficult by the sheer devastation to the area about 40
miles north of Seattle. At least three people were killed and six homes
destroyed.
“There’s nothing left in the area,” he said.
The mudslide hit about 10:45 a.m. Saturday near the community of Oso....
The Sheriff is asking residents in Oso and Arlington to evacuate. Lake Stevens is in the lower right corner of this image, and those towns are further north. They are in the next Quadrangle north of the Snohomish Quadrangle.
