WEDNESDAY April 10th - Baxter's Interurban Grill Event
NOTE: This month's lunch is on WEDNESDAY, instead of the usual Thursday.
11:30 Lunch
12:00 Presentation
Online link https://meet.google.com/caz-ycax-mas
Title: Seismic Hazard Considerations as Oklahoma Approaches Nearly a Decade Since Peak Injection
ABSTRACT:
It has been well-publicized that Oklahoma experienced an unprecedented increase in seismicity. That seismicity peaked in 2015 when there were ~900 M3.0+ earthquakes, relative to a tectonic background rate of just 1-2 M3.0+ earthquakes per year prior to 2009. Many of those events are now understood to have been induced by wastewater disposal, some of which caused moderate but not widespread damage to the rural communities in which they occurred. While most public and regulatory attention has historically been focused on wastewater disposal into the Ordovician-age Arbuckle Group as a causal mechanism, in the last few years hydraulic fracturing (HF) triggers most of the induced seismicity in the state. We will report on our recent efforts to categorize HF-triggered seismicity, over the last decade, through statistical analysis. During the last decade and increasingly as the network has expanded and event detectability has improved through implementation of machine-learning, we find that almost 16% of HF completions are associated with the occurrence of an earthquake. Of those ~8,000 earthquakes associated with HF, ~1,000 were felt and reported to the USGS DYFI. We will discuss a couple of anomalous cases of larger than expected reported intensities, which include significant amplification of seismic waves due to local geology. One of those was a M3.2 HF-triggered earthquake that led to reports of light damage in southern Canadian County, OK. Our findings have important implications for mitigation of HF well completion seismicity as it is occurring and can guide best practices for future long-term geostorage and geothermal projects. In addition, I will discuss 2024 seismicity including sharing our most recent investigation into the Edmond/Arcadia January sequence and the M5.1 Prague earthquake and subsequence aftershock sequence.
BIOGRAPHY:
Dr. Jake Walter is the State Seismologist at the Oklahoma Geological Survey, a University Department and state agency, and affiliate faculty in the School of Geosciences at the University of Oklahoma. He has research interests in earthquake seismology, geohazards, glaciology, and induced seismicity. He is the author of over 40 peer-reviewed publications and has led NSF, DOE, NASA, and FEMA grants. He assists state emergency management and other state agencies with earthquake-related matters and engages in science outreach for audiences at all age levels across the state.
"Geophysical Society of Tulsa (GST)" is a 501(c)3 non-profit organization. Oklahoma, P.O. Box 2784, Tulsa, OK 174101