Mount St. Helens Alert Status Increased

DarkHand writes "Mount St. Helens has become even more unstable in the last few hours. The U.S. Geological Surveys Cascades Volcano Observatory has increased the volcanic alert around the volcano to level 2 and released a press release: 'Over night, seismic activity at Mount St. Helens has accelerated significantly, which increases our level of concern that current unrest could culminate in an eruption. We are increasing the alert level to the second of three levels [...]. Earthquakes are occurring at about four per minute. The largest events are approaching Magnitude 2.5 and they are becoming more frequent. All are still at shallow levels in and below the lava dome that grew in the crater between 1980 and 1986. This suggests that the ongoing intense earthquake activity has weakened the dome, increasing the likelihood of explosions or perhaps the extrusion of lava from the dome.' The most recent readings at the SEP seismograph stationed on the lava dome itself are totally saturated. The ground is now literally constantly rumbling."

Comments

Mt St Helens seismic and other info

[daveschroeder]

Mt St Helens National Volcanic Monument (USFS map, Mapquest map)

USGS earthquake info for Mt St Helens National Volcanic Monument area (wide view)

USGS Cascades Volcano Observatory Mt St Helens seismic observations

Pacific Northwest Seismograph Network Mt St Helens home page (earthquake list)

Re:Mt St Helens seismic and other info

[nawspac]

dont forget the webcam.
http://www.fs.fed.us/gpnf/volcanocams/msh/

Mount St. Helens VolcanoCam

[noselasd]

Hmm. I was hoping to see a live volcano eruption here, but it seems
not to be broadcasting now. Anyone knows why/what's happening ?

Re:How severe?

[southpolesammy]

Seismologists are expecting anywhere from nothing at all (not uncommon following an earthquake swarm, happens at Kilaeua from time to time), to a moderate event.

By comparison, the 1980 blast was a catastrophic event. A medium strength earthquake caused the entire north face of the mountain to crumble in a massive rockslide, which also uncorked the pressure on the magma underneath, resulting in a huge lateral explosion through the rock slide. Imagine a wall of rocks coming at you at 300mph. It's doubtful that something like that will happen again in our lifetimes.