is Mount Saint Helens a supervolcano?

It's a super volcano, we know. But is Washington's leading lava producer a supervolcano? NewScientist is on it:

Graham Hill of GNS Science, an earth and nuclear science institute in Wellington, New Zealand, led a team that set up magnetotelluric sensors around Mount St Helens in Washington state, which erupted with force in 1980. The measurements revealed a column of conductive material that extends downward from the volcano. About 15 kilometres below the surface, the relatively narrow column appears to connect to a much bigger zone of conductive material.

This larger zone was first identified in the 1980s by another magnetotelluric survey, and was found to extend all the way to beneath Mount Rainier 70 kilometres to the north-east, and Mount Adams 50 kilometres to the east. It was thought to be a zone of wet sediment, water being a good electrical conductor.

However, since the new measurements show an apparent conduit connecting this conductive zone to Mount St Helens - which was undergoing a minor eruption of semi-molten material at the time the measurements were made - Hill and his colleagues now think the conductive material is more likely to be a semi-molten mixture. Its conductivity is not high enough for it to be pure magma, Hill says, so it is more likely to be a mixture of solid and molten rock.

Before you start freaking out over a molten apocalypse devouring the west coast, and go do something foolish like canceling your summer vacation, consider the requisite skeptic:

Gary Egbert of Oregon State University in Corvallis, who is a magnetotellurics specialist but not a member of Hill's team, is cautious about the idea of a nascent supervolcano where Mount St Helens sits. "It seems likely that there's some partial melt down there," given that it is a volcanic area, he says. "But part of the conductivity is probably just water."

Let's hope so. It's bad enough having one supervolcano within world-ending distance of the Pacific Northwest. No need for two.