Theoretical and Computational Seismology

Theoretical and Computational Seismology provides the foundation upon which seismic data are analyzed. Research in this area involves the development of computational methods and codes for simulation of wave propagation in 3D heterogeneous, anisotropic, elastic and/or anelastic media, and calculation of finite-frequency sensitivity kernels for various wave phenomena, including head waves, Rayleigh wave ellipticity, and cross-dependence of P and S waveforms and velocities. Simulations of waves propagation are carried out on the University of Rhode Island High-Performance Computers, where the Seismo Lab is the largest contributor and user. Recent and on-going projects include: Passive-source reverse time migration, simulation of wave propagation in anelastic media, Q sensitivity kernels, a hybrid 3D FD simulation of teleseismic body waves, and 3D kernels of Z/H amplitude ratios.

Structure and Dynamics of the Earth's Interior

Discoveries in the Earth's deep interior come from observations of seismic waves recorded on the Earth surface. We use seismic waves to map the Earth's internal interfaces or image the interior in a way similar to a medical CAT scan. The results provide constraints on the thermal and compositional variations in the crust and mantle. Research topics include mid-ocean ridges, hotspots (Iceland, Hawaii, Azores, Tanzania, Galapagos), oceanic plateaus (Ontong Java), subduction zones (Cascadia), passive margins (Eastern U.S.), mantle plumes, crust and mantle structure beneath Eurasia and Africa, continental collision (Tibet), and the mantle transition zone. Recent and on-going projects include: full-wave Pn tomography of Tibet, joint gravity and full-wave seismic inversion of southern California, fault zone structures (San Jacinto), the magma systems at the Cascades volcanic zone and beneath the Long Valley caldera, and the distribution of velocity heterogeneities.

Fieldwork and Cruises

Upcoming Cruises to Galapagos. We are planning for a winter 2021 deployment of 53 ocean bottom seismometers and a spring 2022 instrument recovery, though the ship and instrument schedules are yet to be finalized.

2018 Kilauea Eruption. Yang Shen and Ph.D student Jiahang Li joined a team of scientists from Rice University and West Washington University deployed 12 ocean bottom seismometers offshore Kilauea to record earthquake activities and lava-water interaction.

2015-2016 Solomon Islands. Deployment of broadband seismometers on the Solomon Islands for studying the Ontong Java Plateau.

2006-2010 NETS (Northeast Tibet Seismic Experiment). In collaboration with Chinese Academy of Geosciences, China University of Geosciences (Beijing), University of Houston, and University of Missouri, we carried out a seismic experiment in the northeast Tibetan plateau to understand the rise and growth of the plateau and its interaction with the surrounding tectonic blocks.

2005 SEATOS (Sumatra Earthquake and Tsunami Offshore Survey). Shortly after the December 26, 2004 Sumatra Earthquake, we participated in an offshore survey near the epicenter of the earthquake and obtained images of seafloor ruptures that caused the devastating Indian Ocean tsunami.

ICEMELT

MELT

Seismic, Tsunami, and Volcanic Hazards

Details to come ...