Making Quakes in Austin, Texas
November 9, 2022
After months spent carefully combining black steel plates, delicate sensors, and five hydraulic jacks into a device that mimics the sliding of tectonic plates past each other, a team of researchers and graduate students successfully made an earthquake in the lab on November 7, 2022.
It was an audible snap.
“Today was our first experiment, and—with nothing broken or catching fire—we were able to simulate an earthquake,” smiled Srisharan Shreedharan, a postdoctoral fellow at the Institute for Geophysics at the Jackson School of Geosciences (JSG). “We can now establish a baseline of what’s working or not working for our upcoming experiments.”
The experimental apparatus was designed and built in a cavernous warehouse that houses the UT Morphodynamics Laboratory at UT Austin’s J.J. Pickle Research Campus. Constructed on an industrial metal table wedged among detritus from decades of research on fluids, the device includes a line of four hydraulic jacks that simulate the normal pressure or load between the plates, which in this case are two blocks acrylic plastic. It is a fifth jack that piles sheer stress onto the system, moving blocks of plastic that mimic tectonic plates past each other millimeter by millimeter.
Earthquakes occur along the fault line, or a boundary filled with white quartz powder, when the pressure becomes too great. At this time, sensors record data including the amount of fault slippage, the amount of shear stress within the fault, change in volume within the fault during the quake, and seismic radiation.
“This experimental data can then be compared to our models as well as to real-world data from subduction zones and other fault zones like the San Andreas fault,” said David “Chas” Bolton, a research scientist at the Bureau of Economic Geology. Bolton will soon be leading the experiment. “We now intend to investigate how ruptures start and propagate along bimaterial fault zones.”