"It's gonna blow... Volcano"

(Lyrics from the pop song Volcano, by Presidents of the United States of America)

I only have time for a short entry, but it looks like Mt. Redoubt in Alaska may erupt. One of the omens is the occurrence of harmonic tremors that accompany movement of magma through a volcano. Volcano seismicity is physically different from the tectonic earthquakes that we usually talk about.

Check out the situation at the Alaska Volcano Observatory.

Photo: Redoubt Volcano from the AVO observation hut. The dark flow was growing while work was performed on the Redoubt webcam. Taken 27 Jan., 2009. (www.avo.alaska.edu)