Author(s): Karan Adhikari, University of Houston (First Author, Presenting Author) Behrooz Ferdowsi, University of Houston
We investigate small energy releases known as acoustic emissions (AEs) occurring during fault movements, akin to sounds produced in earthquakes. In laboratory settings, we gently shear a layer of silica powder to simulate crushed rock near the Earth's surface. Using a specially designed apparatus, we control stress, temperature, and humidity while recording AEs with external sensors. Calibration with simple ball-drop tests converts sensor signals into physical measurements. We observe that AEs persist even at very slow slip rates, indicating they likely reflect internal grain motion. This suggests a connection between AE intensity and changes in friction. Our findings offer new insights into fault behavior under low-stress conditions and lay the groundwork for using machine learning to analyze AE signals and predict frictional characteristics.