Topic: "Imaging active tectonics in the remote Brooks Range, Alaska: the 2018 Kaktovik earthquakes"
Speaker: Élyse Gaudreau, School of Earth and Ocean Sciences, University of Victoria, Canada
The largest earthquakes recorded in northern Alaska (Mw 6.4, followed by a Mw6.0 aftershock) occurred 6 hours apart in the northeastern Brooks Range near the village of Kaktovik. Despite northern Alaska being seismically active, the tectonics of this area remain enigmatic because of sparse data availability until recent years. However, Sentinel-1 interferometric synthetic aperture radar (InSAR) satellites and Earthscope Transportable Array seismic data captured the earthquake sequence, giving insight into the little-known active tectonic processes of the region. In this study, InSAR modeling, teleseismic back projections, calibrated hypocentral relocations, and regional moment tensor solutions resolve two previously unknown, SSW dipping right-lateral fault segments. These are the first known active faults that are conjugate to the nearby Canning displacement zone, which seems to be part of a broader zone of deformation than previously thought. Moreover, the Kaktovik sequence possibly reactivated preexisting faults that were previously considered inactive, highlighting the potential for damaging earthquakes on seemingly aseismic faults.
Speaker Bio: Élyse Gaudreau, School of Earth and Ocean Sciences,, University of Victoria, Canada Élyse Gaudreau is a PhD candidate at the University of Victoria whose work focuses on better understanding the relationships between fault zone characteristics and their coseismic deformation patterns, particularly on immature fault zones that have not yet hosted many earthquakes, and are often in conspicuous as a result. She was awarded a NSERC Alexander Graham Bell Canada Graduate Scholarship and a Montalbano Fellows Scholarship for her work involving using mainly InSAR and optical image processing techniques, along with seismic and geologic data, to study earthquakes as far back as 50 years ago.
Prior to her PhD, Élyse received a BSc and MSc from the University of Ottawa where her interest in tectonics led to research projects involving microstructural analyses of rock deformation, potential fields geophysics and thermochronology.
Because of Physical Distancing our luncheons will be virtual until further notice.
VIRTUAL MEETING ONLINE
TIME: Virtual doors open at 11:30 (Alaska Time), Announcements start at 11:45, Talk starts at 12:00