Student Opportunities for Future Research
Glenn Spinelli, Assistant Professor of Geophysics

    I have two opportunities for a graduate student beginning in 2009. Details of the projects are given below, and feel free to contact me if you are interested in working on either of these projects.

Hydrothermal circulation in subducting crust
    This project involves modeling the thermal effects of fluid transport in subducting ocean crust. Seafloor heat flux observations on the Nankai margin of Japan suggest that fluid flow in ocean crust is redistributing heat -- and this fluid flow reduces temperatures in the subduction zone. In an extension of this work, I want to work with a student to test the hypothesis that similar hydrothermal circulation occurs in subducting crust on the Cascadia and Costa Rica subduction margins. For this project, a student will work with a subduction zone thermal model and heat flux observations to constrain the potential thermal effects of fluid circulation on these margins.

Sediment cementation and deformation in the Nankai margin accretionary prism
    This project involves examining cementation of sediment entering the accretionary wedge off southern Japan. The hypothesis to be tested is that a small amount of opal cement dramatically affects the deformation of hemipelagic sediment on this margin - specifically, the cement inhibits fracturing of this accreted sediment. This has implications for the hydrogeology of the margin, as fractures greatly enhance the permeability of the margin wedge sediment. A student working on this project will determine the degree of opal cementation of sediment samples using a variety of laboratory methods (e.g., electron microprobe, alkaline leaching of silcates). Ultimately, the student will collaborate with colleagues performing geotechinical engineering tests on the same sediments to gain an understanding of the cement's effect on sediment strength and deformation.