Monique M. Holt
(née Scales)
About me:
I'm a PhD candidate with the University of Utah Seismograph Stations. I'm also the president of Inclusive Earth, a student-led DEJI organization in the College of Mines and Earth Sciences.
Research Interests:
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Forensic seismology
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Machine learning applications
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Anthropogenic earthquakes
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Earthquake relocation
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Network seismology
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RECENT PUBLICATIONS
Baker, B., Holt, M. M., Pankow, K. L., Koper, K. D., Farrell, J. (2021). Monitoring the 2020 Magna, Utah, Earthquake Sequence with Nodal Seismometers and Machine Learning, https://doi.org/10.1785/0220200316.
Koper, K. D., Holt, M. M., Voyles, J. R., Burlacu, R., Pyle, M. L., Wang, R., Schmandt, B. (2020), Discrimination of Small Earthquakes and Buried Single-fired Chemical Explosions at Local Distances (<150 km) in the Western U.S. from Comparison of Local Magnitude (ML) and Coda Duration Magnitude (MC), https://doi.org/10.1785/0120200188.
Pang, G. G., Koper, K. D., Mesimeri, M., Pankow, K. L., Baker, B., Farrell, J., Holt, J., Hale, J. M., Roberson, P., Burlacu, R., Pechmann, J. C., Whidden, K., Holt, M. M., Allam, A., DuRoss, C. (2020), Seismic Analysis of the 2020 Magna, Utah, earthquake sequence: Evidence for a listric Wasatch fault, https://doi.org/10.1029/2020GL089798.
Voyles, J. R., Holt, M. M., Hale, J. M., Koper, K. D., Burlacu, R., Chambers, D. J. A. (2020), A New Catalog of Explosion Source Parameters in the Utah Region with Application to ML-MC-Based Depth Discrimination at Local Distances, https://doi.org/10.1785/0220190185.
Holt, M. M., Koper, K.D., Yeck, W., D'Amico, S., Li, Zongshan, Hale, J. M., Burlacu, R. (2019), On the Portability of ML–MC as a Depth Discriminant for Small Seismic Events Recorded at Local Distances,
EDUCATION
2017–Present
PhD Candidate, Geophysics
UNIVERSITY OF UTAH
Advisor: Dr. Keith Koper
Thesis Title: Seismic Discrimination of Small Events Recorded at Local Distances
2015–2017
M.S., Geophysics
SOUTHERN METHODIST UNIVERSITY
Advisor: Dr. Heather DeShon
Thesis Title: A decade of induced slip on the causative fault of the 2015 Mw4.0 Venus earthquake, northeast Johnson County, Texas
2011–2015
B.S., Geophysics
B.S., Applied Mathematics
SOUTHERN METHODIST UNIVERSITY
RESEARCH
ML-MC: Depth Discriminant
Seismic depth discriminants are effective for event screening of small seismic events recorded at local distances. One such discriminant is the difference between local magnitude and coda duration magnitude (ML-MC). Studies have shown that this method is an effective discriminant in Yellowstone, Utah, Oklahoma, Italy, Wyoming, Washington, and Nevada. The next step is to figure out (1) how ML-MC works as a depth discriminant, and (2) how to simplify the problem.
This work is ongoing and will comprise my PhD thesis at University of Utah with advisor Dr. Keith Koper. The first chapter has already been published in BSSA.
https://doi.org/10.1002/2017JB014460.
Related studies:
https://doi.org/10.1785/0120200188
Magna Focal Mechanisms
On 18 March 2020 a M5.6 earthquake occurred in Magna, UT, just west of Salt Lake City. Due to the notable seismic hazard in the area, the University of Utah Seismograph Stations had >150 permanent seismometers that recorded the mainshock. Additionally, >150 temporary 5-Hz geophones were deployed for approximately 30 days. For this study we use the large-N array and machine learning to generate focal mechanisms. Our results (1) highlight the utility of modern seismological tools such as the portable geophones and machine learning, (2) confirm the extensional stress regime of the Salt Lake Valley, and (3) comment on the behavior of the Wasatch Fault at depth.
This work will be submitted shortly.
The seminal paper can be found here: https://doi.org/10.1029/2020GL089798
Induced Seismicity
In May 2015 there was a M4.0 earthquake near Venus, Texas which is just south of the Dallas-Ft. Worth Metroplex. At the time, there were five high-volume saltwater disposal wells operating within 5 km of the mainshock. We used matched-filter detection, double-difference relocation, focal mechanisms, seismic reflection profiles, and data analysis to show that the injection layer was over-pressured, which likely led to the earthquake sequence.
This work was conducted as part of my Master's thesis at Southern Methodist University with advisor Dr. Heather DeShon. The article study was published in JGR. https://doi.org/10.1002/2017JB014460.