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Sean Gulick |
Active tectonics: convergent margins, transitional tectonics and microplates, seismic hazards, and tectonic-glacial climate interactions. Impact cratering: Chicxulub, mass extinctions, and impact deformation.
Research Interests
Sean’s primary scientific interest is
in the examination of deformation of the Earth in convergent margins, complex
transitional tectonic environments such as microplates, and the massive
deformation due to bolide impacts. Convergent margins represent the most
numerous and potentially most deadly locales for earthquake production, requiring
a greater understanding of the interplay of subduction zone tectonics,
structural deformation, accretionary prism development, and migration of fluids
and gases from deep in the accretionary margin to the seafloor. Deformation in
active tectonic regimes affects the geologic record of the continental margins
and basins through sediment deformation, uplift and/or subsidence, orogenesis,
and interplay with climate. A completely non-tectonic source of deformation in
the earth and yet vital to understanding the planet's history are impacts from
meteors and comets and their effect on global climate and life. 2-D and 3-D
seismic reflection techniques provide both regional and/or local information
regarding the nature and timing of the deformation, yield partial geologic
histories of basins, and can be used to examine the physical properties of the
fault zones. Information gathered by the marine geophysical techniques is even
more powerful when ground-truthed using ocean drilling and/or direct submersible
observations.
Current projects that Sean, his students, and colleagues are working on include high-resolution imaging of sediments in south-east Alaska’s fjords and continental shelf basin to investigate glacial erosion in a complex tectonic setting and interpretation of a new suite of seismic reflections lines collected this year over the Chicxulub impact crater. Planning is underway for additional seismic studies (see STEEP) in Alaska, investigating the tectonic underpinnings, crustal structure, and geologic-climatic history that has built the highest coastal mountains in the world (the St. Elias Mountains) and potentially affected northern hemisphere climate. An industry-collected 3-D seismic experiment to image the Nankai trough near the Kumano Basin is proposed to examine in detail the seismogenic (earthquake producing) portion of the subduction zone off southeast Japan. Integrated Ocean Drilling Program (IODP) expeditions to the Gulf of Alaska to investigate tectonic-climate linkages (see NSF-JOI Workshop), to the Nankai trough to study seismogenesis (NanTroSEIZE), and to the Chicxulub impact crater to understand impact cratering and cause of the K/T mass extinction are all in the planning stages.
Ongoing Projects
Exploring Structural Controls on Great Earthquake Rupture and Architecture of the Sumatra-Andaman Convergent Margin
St. Elias Erosion/Tectonics Project (STEEP)
US-Japan Collaborative Investigation of Nankai Subduction Thrust Seismicity and Fault Properties
Ocean Drilling Program Leg 196, Nankai Trough
Recent Publications
Mosher, D.C., J.A. Austin, Jr., D. Fisher, and S.P. Gulick, Deformation of the northern Sumatra accretionary prism: evidence for strain partitioning from high-resolution seismic reflection profiles and ROV observations: Marine Geology, submitted, June 2007.
Gulick, S., Barton, P., Christeson, G., McDonald, M., Mendoza, K., Morgan, J., Pearson, Z., Surrendra, A., Urrutia, J., Vermeesch, P., Warner, M., Importance of pre-impact crustal structure in the asymmetry of the Chicxulub impact crater: Nature Geosciences, in revision, August, 2007.
McDonald, M., Gulick, S., Melosh, J., Oblique impacts and peak ring position: Comparing Venusian craters to Chiculub: Geophysical Research Letters, in revision, August, 2007.
Lowe, L., Gulick, S., Pavlis, T., Bruns, R., Mann, P., Localized deformation zones in the offshore leading edge of the Yakutat microplate, Gulf of Alaska: AGU Monograph, accepted, August 2007.
Gulick, S., Lowe, L., Pavlis, T., Mayer, L., 2007, Gardner, J., Geophysical insights into the Transition fault debate: Propagating strike-slip in response to stalling Yakutat block subduction in the Gulf of Alaska: Geology, v. 35, p. 763-766; doi: 10.1130/G23585A.
Fisher, D., Mosher, D., Austin, J. A., Jr., Gulick, S. P. S., Masterlark, T., and Moran, K., Active deformation across the Sumatran forearc over the December 2004 Mw9.2 rupture, Geology, v. 35., pp. 99-102, DOI: 10.1130/G22993A.1, 2007.
Nordfjord, S.*, Goff, J. A., Austin, J. A., Jr., Gulick, S. P. S., Seismic facies of incised valley- fills, New Jersey continental shelf: Implications for erosion and preservation processes acting during latest Pleistocene-Holocene transgression: J. Sed. Res., v. 76, p. 1284-1303, DOI: 10.2110/jsr.2006.108, 2006.
Sean's UTIG Contributions (Publications)