Dino Huang, Ph.D.
Jackson School of Geosciences
Bureau of Economic Geology
The University of Texas at Austin
Earthquake activities in areas across the Midland Basin and the Central Basin Platform of West Texas have significantly increased since mid-2019 due to continuing industrial activities. The induced seismicity has allowed us to discover previously unknown seismogenic structures. In this seminar talk I will present a recent study focusing on seismotectonic characteristics of the Midland Basin. Based on the seismicty distribution and source mechanism patterns, a number of distinctive seismicity groups have been identified. A vast majority of seismicity are located in the crystalline basement. Most of the seismicity groups contain structures that commonly present linear geometry but with various orientation. While the inverted focal mechanisms are a mix of strike-slip and normal faulting, the inverted stress filed contains the least compression axes (S3) that are commonly oriented in 330° azimuth across the identified seismicity groups. In contrast, the maximum compress axes (S1) rotates from horizontal to vertical across the seismicity groups. A combination of all seismogenic features has demonstrated that the Midland Basin contains fault architectures resulted from previous extensional tectonic activities, accommodated by a series of basement-rooted strike-slip and normal faults. They are reactivated by the current fluid injection.