Current Research in EEPS: Alice Turner, University of Oxford
Repeating earthquakes across the Earth-Moon system
Abstract:
Repeating earthquakes rupture the same area of fault at different times. They occur in a diverse range of environments including crustal strike slip faults and subduction zones along with more unusual non-tectonic settings, including glaciers, volcanoes and even on the moon. The repetitive nature of these events makes them useful tools for tracking slip rates or studying fault properties, yet we do not understand their underlying physics. In this talk, split into two parts, I will discuss my work to unravel some of the puzzles of these quakes across the Earth-Moon system.
Firstly, I will focus on repeating events in Parkfield, California. The recurrence time of these events should be intuitive — the next earthquake in a particular location will occur when the strain drop has recovered. But these events occur less frequently than one would expect from theoretical scaling laws. Recent models suggest a possible explanation: small earthquakes could occur between repeating events as “partial ruptures”. To test this model for repeating seismicity, I search for these partial ruptures in the high-quality seismic catalogues in Northern California.
In the second part of this talk, I will focus on deep repeating moonquakes. Deep moonquakes occur in clusters, at 700–1,200-km depth, and provide unique insight about the stresses deep in the lunar interior. Using observations of deep moonquake waveforms, I find tidal stresses to be the main driver of deep moonquakes. Based on these results, I intend to ll discuss the potential implications for lunar structure and the mechanism of deep moonquakes. Finally, I present my current and future research directions.
Zoom information:
https://riceuniversity.zoom.us/j/92141793780?pwd=dERRMmtPZnNuRGVycmRWWmhnUXN3UT09
Passcode: 604165
Webinar ID: 921 4179 3780
