identifying shallow slow slip using natural & experimental hematite slip surfaces
Slow slip, or the movement along a fault without an earthquake, is a fundamental part of the seismic cycle. In the near-surface environment, slow slip may impact a range of tectonic processes and seismic hazards, including reducing earthquake energy, controlling how earthquakes stop, and the intensity of ground shaking. A critical unknown is how the material properties of fault rocks control this phenomenon. Our research focuses on a segment of the San Andreas fault that is overdue for a large earthquake and has experienced recent slow slip events. We are leveraging the unique textural and geochemical qualities of hematite, a common mineral in faults, to determine the prevalence, timing, and impact of slow slip along the southern San Andreas fault in Mecca Hills, California. Comparison of observations from natural hematite-coated faults with laboratory deformation experiments will document how hematite deforms to understand what governs where and why slow slip occurs.
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Data will be integrated into a new educational program, the Providence (Utah) to Providence (Rhode Island) Partnership, that will connect rural and urban students in different parts of the country and impact more than 450 elementary and middle school students. Research and broader impact activities will provide mentoring and role modeling opportunities for middle school through faculty levels, critical for expanding and diversifying the sciences through each stage of education and training. This NSF-funded work is collaborative with Co-PI Greg Hirth (Brown University), with help from Kelly Bradbury and Jim Evans (USU), and Peter Reiners (University of Arizona).
Publications (denotes * graduate mentee)
*Moser, A.C, Evans, J.P., Ault, A.K., Janecke, S.U., Bradbury, K.K., 2017, (U-Th)/He thermochronometry reveals Pleistocene punctuated deformation and synkinematic hematite mineralization in the Mecca Hills, southernmost San Andreas Fault zone, Earth and Planetary Science Letters, v. 476, p. 87-99, doi: 10.1016:/j.epsl.2017.07.039.
*DiMonte, A.A, Ault, A.K., Hirth, G., Bradbury, K.K, 2022, Hematite accommodated shallow, transient Pleistocene slow slip along the exhumed southern San Andreas fault system, California, USA, Geology, v. 50, 1443-1447, doi: 10.1130/G50489.1
*DiMonte, A.A, Ault, A.K., Hirth, G., Meyers, C., in prep., Hematite frictional behavior and He loss during slow slip deformation experiments, to be submitted to JGR – Solid Earth.
*Moser, A.C, Evans, J.P., Ault, A.K., Janecke, S.U., Bradbury, K.K., 2017, (U-Th)/He thermochronometry reveals Pleistocene punctuated deformation and synkinematic hematite mineralization in the Mecca Hills, southernmost San Andreas Fault zone, Earth and Planetary Science Letters, v. 476, p. 87-99, doi: 10.1016:/j.epsl.2017.07.039.
*DiMonte, A.A, Ault, A.K., Hirth, G., Bradbury, K.K, 2022, Hematite accommodated shallow, transient Pleistocene slow slip along the exhumed southern San Andreas fault system, California, USA, Geology, v. 50, 1443-1447, doi: 10.1130/G50489.1
*DiMonte, A.A, Ault, A.K., Hirth, G., Meyers, C., in prep., Hematite frictional behavior and He loss during slow slip deformation experiments, to be submitted to JGR – Solid Earth.