An abiding interest of mine is the deep structure of magmatic arcs -- especially island arcs.
Our group has undertaken a large reflection/refraction seismic study of the magmatic arc in Costa Rica.
To see a map of the offshore data collection, conducted in Feb-April 2008, click on the thumbnail below:
The Aleutian island arc is a terrific place to study the processes that create arc crust, due to its relatively simple tectonic setting.
I first got involved in studying the orign of arc crust through a 1994 marine seismic survey I participated in while I still was at WHOI, together with a number of other PI's (Sue McGeary, John Diebold, Nathan Bangs, and Simon Klemperer). The survey consisted of seismic reflection data acquired by the R/V Ewing and wide-angle seismic data acquired on ocean-bottom seismic instruments (which our group deployed from the R/V Alpha Helix) and land instruments on the islands deployed by the Stanford group.
This paper showed results from one of the cross-arc lines in the Aleutians (A1), based on reflection and OBS data (Fig. 1 at right). The results showed that the average velocity structure of the arc on Line A1 was too fast to represent a bulk andesitic composition and was significantly faster (and thus more mafic) than mature continental crust (Fig. 2 at right).
You can download a PDF of the paper here.