Abstract

Induced seismicity is a central issue in the development of subsurface energy technologies in the United States and around the world. Examples include subsurface wastewater injection, reservoir impoundment in the vicinity of large dams, development of mining, geothermal or hydrocarbon resources, and in geologic carbon sequestration. While most of the induced earthquakes are fortunately too small to be felt, some can go up to magnitude 5—large enough to be felt and to cause damage to buildings. Understanding the physical mechanisms behind induced seismicity is essential to successful management and mitigation of the seismic risk associated with subsurface energy technologies. As a first step in my research, I developed a zero-dimensional spring-poroslider model of frictional slip as an analog for induced seismicity to explain the common observation that abrupt increases in injection rate increase the seismic risk. Second, I perform an energy analysis using the same spring-poroslider model to shed light into the partitioning of energy released into frictional and radiated energy—since the latter is associated with the overall size of the earthquake and its potential for damage to man-made structures. Third, I extend the model to two-dimensions to reproduce laboratory experiments of injection-induced fault slip. Fourth, I study the effect of heterogeneity on the dynamics of frictional faults. In particular, I analyze stick-slip behaviors resulting from spatially heterogeneous Coulomb friction, and find that this heterogeneity alone leads to slip dynamics qualitatively similar to a wide range of slip behaviors observed in nature from fault creep and low frequency earthquakes to ordinary earthquakes and slow slip events. This research, as a whole, enhances our understanding of the mechanics of fluid-injection-induced earthquakes and suggests strategies that mitigate or minimize the seismic risk associated with subsurface operations.

Bio

Maryam is an Ibn Rushd postdoctoral fellow at Caltech. She obtained her Ph.D. in computational science and engineering from MIT, MS in civil and environmental engineering from UC Berkeley, and BS in petroleum engineering from Texas A&M University. She also worked as a reservoir engineer at Saudi Aramco for a few years. Her research interests include fluid flow in porous media, friction, and earthquakes.