2016 Birdsall-Dreiss Distinguished Lecturer – Geological Society of America
Professor of hydrogeology – Department of Geological Sciences, University of Colorado-Boulder
Title: Fluid Induced Earthquakes: Insights from Hydrogeology and Poro-mechanics
Date: Thursday, March 24, 2016
Time: 3:30 PM – 4:30 PM
Location: 100 Williamson
Beginning in the 1960s, pore fluid pressure was identified as the primary culprit for inducing earthquakes reported near deep fluid-injection wells and newly built surface reservoirs worldwide. As these human activities continue and grow, induced seismicity has surged in recent decades at some but not all sites. This increase in seismicity raises the question of what fundamental hydrogeologic and poro-mechanics processes and parameters make some sites more prone to induced seismicity. This lecture will offer an overview and physical insights of fluid induced seismicity from hydrologic and poro-mechanics perspectives. Two contrasting case studies are used to illustrate how pore fluid pressure could have played a role in observed seismicity, one near a deep well fluid injection in the geologically quiescent region in the central US, and the other near a surface reservoir in a tectonically active region. High rate of fluid input emerges as an important player in contributing to induced seismicity. The first few years of fluid injection or reservoir impoundment is typically a critical period when seismic hazard is elevated. While pre-existing faults dictate earthquake locations, the spatial extent of pore pressure influence could reach tens of kilometres from fluid injection or reservoir impoundment sites. Continued research in this direction will not only offer a better understanding of the hydrogeologic and seismologic processes but also help to guide best practices in the quest for water and energy resources in coming decades.