Agrigan

Our tour of the Marianas begins SW of Guam. In this area the volcanoes are submerged and make up a region known as the Southern Seamount Province. Our first stop is Tracey Seamount, which lies 30 km west of Guam. Tracey is a ~2 km tall cone and volume of ~45 km3 It is one of the smaller volcanoes in the Mariana arc; Pagan, contains about 2200 km3 of material (Bloomer et al., 1989). It has a sector collapse on its western flank and resembles a submarine Mt. St. Helens. It was investigated by the ROV Hyper-Dolphin from the R/V Natsushima in Feb. 2009, which revealed that the cone is map up of…

This week I welcome Dr. Ed Kohut as a guest blogger here on Eruptions (while I am off in the Sierras doing some field work). I've known Ed for 10 years now - we were both graduate students in igneous petrology at Oregon State University - and we are both Massachusetts natives. Ed was in the Coast Guard before getting degrees at University of Rhode Island and Boston University before heading of to Oregon State for a Ph.D., where he worked on melt inclusions in minerals. One of his major research areas is magmatism in the Mariana Islands and he was nice enough to put together a look at the…