St. Helens & Dreams

I've related in the past the dreams I've had involving massive volcanism. When St. Helens blew it's top I thought it had begun. I have looked at the activity of various Cascade volcanoes and while geologists claim they are independent, I believe I see a pattern in that most of the time when one becomes active, most of the others do within a century, with the exception of Mt. Rainier. Many years have passed, and there hasn't been a major increase in volcanic activity. St. Helens continues to do dome building since 2004.

An article about Mt. St. Helens, in physorg.com, suggests that St. Helens has become an open system like Kilauea in Hawaii with magma being replenished from a source deep within the earth as fast as it comes to the surface. This is indicated by the fact that the flanks are no longer distorting as they would if the magma chamber were emptying.

Usually Cascade volcanoes are thought to be the result of subducting Pacific Ocean plate re-melting and rising to the surface, not a continuous flow process. Kilauea is fed by a hot spot which may be bringing material all the way from the core-mantel boundary. Such a hot spot also exists beneath Yellowstone. At one time it existed beneath the area along the Washington-Oregon border and was thought to be the source of the huge Columbia River Basin basaltic floods that occurred between 17 million and six million years ago. The North American plate moved westward and overtime the hot spot under it gradually moved eastward until it assumed it's present position under Yellowstone.

Recent analysis of the chemical composition of these basaltic floods suggests a lithospheric mantel source rather than a deeper asthenic source. It is still possible that the hot spot played a role in the lithospheric instability but the actual source of magma does not appear to be deep.

My concern is that as the plate moved over the hot spot, that a sort of hot trail back towards this region remained, sort of a conduit, that perhaps would feed these Pacific volcanoes.

In central Oregon, west of Bend, there is a patch of land that began rising in 1997 and has continued to rise at a rate of 1.4 inches per year. According to an article in PhysOrg.com, the land has continued to rise at this rate and in 2004 a swarm of 350 small earthquakes indicated magma movement under ground.

The Yellowstone super volcano system has erupted on average every 600,000 years, it's been 620,000 since the last eruption. Is it gearing up for another? Part of the Cascade system may be plumbed into it and participate.