Opportunities for Geophysics Research at the Scripps Institution of Oceanography

Geophysics at SIO includes experimental and theoretical projects on a wide range of topics. The purpose of this brief report is to highlight some of the ongoing and planned programs that are likely to involve graduate student participation.

Crustal Deformation and Geodesy

These are exciting times in crustal deformation studies because of the new constraints provided by satellite observations such as GPS and InSAR. Yehuda Bock runs a continuous GPS network in southern California as well as a field program in Indonesia. He is currently experimenting with the use of high-sample rate GPS to directly observe dynamic displacements during earthquakes. Yuri Fialko has been pioneering new methods for analysis of InSAR data (see SIO Satellite Geodesy) and has funding for one to two new students, who are likely to work on: (1) modeling the interseismic strain accumulation and tectonics of the southern San Andreas Fault, or (2) InSAR analysis and modeling of volcanic deformation in South America. He is also involved in a field seismic experiment planned for the Mojave in summer 2006 to image the Calico fault, which InSAR data suggest should have a 1 to 2 km wide low velocity zone. Duncan Agnew operates several laser strain meters in southern California, including one at the Pinon Flat Observatory. Duncan often uses student volunteers for GPS field work in southern California and has funding for a new grad student. When he’s not surfing, David Sandwell uses InSAR and other satellite remote sensing data to study and model crustal deformation, including the response of the southern California crust to the recent M 7 Landers and Hector Mine earthquakes.

Electrical Methods

Scripps has been a pioneer in marine electromagnetic methods and instrumentation and is a world leader in this field (see SIO Marine EM). EM research at IGPP is led by Steve Constable and has involved development of seafloor instrumentation, data inversion techniques, and laboratory studies of rock properties. In recent years an explosion of interest and financial support for EM methods from the oil industry has helped expand Steve’s program and ensure lucrative job offers for his graduates. Recent cruises have included the East Pacific Rise, off-shore Angola, northern Japan, the Faroe Trough, and Hydrate Ridge off the Oregon coast. Planned cruises include Loihi, Hawaii, this summer and several short cruises in the Gulf of Mexico and off-shore San Diego during the next year. Often space is available for student volunteers even if they are not directly working on the EM program.

Geomagnetism and Paleomagnetism

Scripps has developed and pioneered the use of inverse theory for analysis of geomagnetic data. Bob Parker (right) is an expert on inverse theory and recreational cycling. Ongoing research projects make use of satellite and observatory magnetic field data to study the electrical conductivity of Earth’s mantle and of paleomagnetic data to evaluate the character and evolution of Earth's geomagnetic field and the nature of the geodynamo in the core. Scripps operates a paleomagnetic laboratory, and Hubert Staudigel and Lisa Tauxe hope to be collecting more paleomagnetic rock samples in Antarctica and may need student volunteers for a project to determine long term magnetic field structure at high latitude. Cathy Constable has funding for one new student to work on millennial scale secular variation of the magnetic field.

Marine Seismology

Scripps operates part of the national Ocean Bottom Seismometer (OBS) instrument pool (see OBSIP), which was recently used by Gabi Laske as part of the Hawaiian PLUME experiment. However, another competitor in the nicest place to do field work contest is the Lake Tahoe profiling work of Graham Kent, who used an instrument designed by SIO’s Neil Driscoll to study the history of faulting in the lake sediments (see Geology press release). Student volunteers are likely to continue to be needed for Lake Tahoe field work, as well as for a Salton Sea sediment imaging project, assuming that this proposal is funded.

Seismology and Deep Earth Studies

Scripps scientists are at the forefront of both experimental and theoretical seismology. Guy Masters is a leader in the effort to develop three-dimensional models of the structure of Earth's mantle and core based on normal mode, surface wave dispersion measurements, and body-wave travel times. He has funding for one additional student, who will probably work on analyzing and inverting surface waves to build new models of anisotropy throughout the upper mantle. Peter Shearer likes to crunch large seismic data sets and works in both global and California seismology. Check out the cool animation of the 2004 Sumatra earthquake rupture (work done with postdoc Miaki Ishii, now an Assistant Professor at Harvard where the weather is infinitely worse than San Diego). Peter has funding for at least one additional student, who will have a choice of several projects, provided they are willing to learn a little FORTRAN. Sofia Akber uses thermodynamics and statistical mechanics to model the chemistry and elastic properties of mantle and core minerals with IGPP's Wolfpack computing cluster. She has funding for one new graduate student and is particularly eager for one with training or interest in quantum mechanics.

Instrumentation

Scripps is one of the few institutions that designs, builds and tests new geophysical instruments, including Ocean Bottom Seismometers, seafloor EM instruments (see above), laser strainmeters, optical gravimeters, and infrasound detectors. LeRoy Dorman has made a new implosive source for midwater or seafloor use. IGPP operates the IDA seismic network and the Broadband Data Collection Center. Mark Zumberge (right) is currently experimenting with optical seismometer design, optical fiber strainmeters, and infrasound detectors. He typically goes to sea several times a year to deploy instruments and has funding for a new student to work on fiber optic sensors, included a strain meter recently installed at the SAFOD drill hole on the San Andreas Fault near Parkfield.

Graduate student life

SIO is a fun place and students, faculty, researchers, and staff have many opportunities to pursue their hobbies or just to relax on the beach. Most Earth scientists love the outdoors and there are scores of opportunities for year-round outdoor recreation, including running (Jeremy, Cathy, Debi, Judy, John), biking (Bob, Michael), tennis (Peter, German, Jeff, Wayne), horseback riding (Guy, Karen), surfing (David, Graham, Jeff), climbing (Fiona, Graham), skiing (Frank, Renee, Bettina, Karen, Guy, Steve, Cathy), yoga (Cathy, Steve, Lisa), orienteering (Alistair) and ultimate frisbee (John, Michael). We have many amateur musicians, including both classical (Urska, Lisa, Wayne), and popular (Joseph, Robin, Scott). Other hobbies include ballet (Urska, Bettina), film making (Kerry, Peter), wildlife photography (LeRoy) and star gazing (Kris, Michael, Wayne, Peter). There typically is a student cruise every year, and a field trip to Fossil Canyon (see right) in Anza Borrego park. Most students attend the Fall AGU meetings in San Francisco and usually several workshops and at least one overseas conference.