Geological constraints on the mechanisms of slow earthquakes

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Earth's tectonic plates are constantly moving and slipping by one another. Although the tectonic plates move at constant velocities over geological time, the rates of motion at the plate boundaries, where relative motions are localized, are much more complex. Observed slip rates across plate boundaries range from very sudden, rapid motion in earthquakes to creep at approximately the long-term average of the plates on either side. Recent seismological and geodetic observations have defined a suite of phenomena, called `slow earthquakes', which are like regular earthquakes, but their slip rates are slower so they can last for weeks. Because slow earthquakes happen more frequently than regular earthquakes in some places, they present an exciting window into the controls on slip at depth. If we could understand the mechanisms of slow earthquakes, they might be a tool for monitoring and forecasting large, potentially devastating regular earthquakes. In the next five years, my research program will focus on slow earthquakes to inform the basic physics that controls them and to investigate how slow earthquake slip is related to seismic slip and creep. My research group and I will address several key objectives: 1. Determining what limits the slip rate in slow earthquakes to stop them becoming regular earthquakes; 2. Explaining how slow earthquakes can occur in a wide variety of tectonic settings by establishing the underlying process; 3. Defining the spatial and temporal relations between slip in slow and regular earthquakes to assess potential causal relations between them; 4. Determining what controls the sizes of slow earthquakes. We will implement an integrated geological field, micro-analytical, and experimental research program that is designed to overcome the spatial resolution limitations of seismology and geophysics. This work will be at the forefront of the emerging field of geologically focused research seeking to investigate slow earthquakes by yielding genuinely novel data that target specific aspects of the mechanisms of slow earthquakes. The outcomes can provide the foundation for modelling and observational work that defines how slow and regular earthquakes modulate one another and, ultimately, may lead to a basis for using slow earthquakes as a tool for forecasting future earthquakes. This research program will support four graduate ¬level and five or more undergraduate research projects. I work hard to create a training environment that is fair, transparent, and inclusive. My training philosophy incorporates steps throughout the research experience, from recruitment to graduation, that aim to broaden participation in the Geosciences, particularly from under-represented groups. By participating in my research program, trainees will develop a valuable range of technical, data analysis, project management, writing, and presentation skills to prepare them for careers in a range of science and engineering industries or academia.