A high-resolution, integrated study of seismic structures and risks

点击翻译按钮获取中文摘要

The Earth is a complex dynamic system. While its fundamental characteristics generally subscribe to the simple theory of plate tectonics, the detailed elastic properties of crust/mantle rocks and the origins of earthquakes differ from region to region. Sufficient data coverage and improved knowledge of seismicity, subsurface velocity, stratification and stress condition are prerequisites for an accurate assessment of plate histories and states. The proposed research program will target both issues based on a multi-scale, integrated study. The two key components of the proposed program are: (1) to quantify the regional seismic structures and risks beneath western Canada, and (2) to improve the quality of global crust and mantle seismic images, emphasizing subduction zones, ridges and hotspots. The first element of the proposed program will combine passive-source deployments of broadband seismometers with laboratory-based analyses of seismic risk, velocity and anisotropy. It will expand the success of the Canadian Rockies and Alberta Network (CRANE), the first broadband seismic array in Alberta, by compiling accurate regional catalogues of microseismic activity and maps of three-dimensional seismic velocity. Expected research outcomes, especially those pertaining to the origin and distribution of local microseisms, could directly impact the environmental policies/decisions that are vital for the sustained economic growth in the province of Alberta. The second component of this proposal will be a laboratory-based, global analysis of earthquake data from existing seismic networks. The availability of broadband data and novel array-based imaging methods will enable high-resolution snapshots of the crust and mantle beneath various tectonic regimes. The two components of the proposed research program are complementary in scale and scope. Together, they form a solid foundation for long-term studies of plate history and seismic risk. The proposed program will be an integral part of the research and training of several graduate students. It will also present summer research opportunities for undergraduate students, as well as training for other highly qualified personnel.