Few weeks later, of rumbling, burping buildup, lava finally punched through to the surface at Mount St. Helens early yesterday.
But it happened so quietly even scientists didn't realize it at first.
Only after infrared instruments revealed that a fin of rock the size of a six-story apartment building registered nearly 1,100 degrees did geologists conclude it was made up of partly hardened lava.
"The fact that we see stuff at the surface that hot means it's new rock," said U.S. Geological Survey volcanologist Willie Scott, informs The Seattle Times.
According to Seattle Post Intelligencer, for the first time in 18 years, lava has broken the surface of this restless volcano, pushing its way out Monday afternoon in an inky gray spine of crystallized molten rock from what scientists are calling a new lava dome.
As tall as a six-story building, the solid but intensely hot crest of surfacing lava - dubbed "the slab" and "the fin" by scientists here - signifies a new phase of &to=http://newsfromrussia.com/accidents/2004/10/08/56494.html' target=_blank>activity for St. Helens: a period of dome building that could last for years and could be marked by quiet flows of lava or explosive eruptions of it. The new slab of lava "could be considered the cork in the bottle," John Pallister, a U.S. Geological Survey volcanologist, said yesterday, adding: "We're still concerned about the possibility of a more explosive event." In recent weeks, the crater floor near the southern part of the lava dome has been pushed up more than 330 feet by rising magma. That is also the location of the steam emissions and the new lava extrusion.
"We are in a period that we are comfortable calling renewed lava dome growth," said Dr. Tina Neal of the geological survey. She said the activity was likely to grow and ebb over the coming days, months and perhaps even years. Scientists still do not know how much molten rock has risen into the volcano or even exactly where it is, although they suspect much of it is within half a mile of the surface.
More explosive eruptions could still occur, Dr. Neal said, adding: "We could see an escalation of unrest come on very rapidly, and this could occur without much warning.