SELECT PUBLICATIONS

Forensic seismology

• Wang, R., Schmandt, B., Holt, M., Koper, K. (2021). Advancing local distance discrimination of explosions and earthquakes using joint P/S and ML–MC classification, https://doi.org/10.1029/2021GL095721.

• 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, Z., Hale, J. M., Burlacu, R. (2019). On the portability of ML–MC as a depth discriminant for small seismic events recorded at local distances, https://doi.org/10.1785/0120190096.

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Network seismology

• 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.

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Induced seismicity

• Scales, M. M., DeShon, H. R., Magnani, M. B., Walter, J. I., Quinones, L., Pratt, T. L., Hornbach, M. J. (2017). A decade of induced seismicity on the causative fault of the 2015 Mw 4.0 Venus earthquake, northeast Johnson County, Texas, https://doi.org/10.1002/2017JB014460.

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Diversity, Equity, Inclusion

• Lerback, J. C., Holt, M. M., Enriquez St. Pierre, G. A., Putman, A., Tulley-Cordova, C. L., Smith, W. A., Caughman, L., and Alvarez, S. (2022). Community voices: Achieving real diversity in STEM requires the ability to transform institutions, https://doi.org/10.1038/s41467-021-27376-4. 

• Velasco, A. A., Aderhold, K., Alfaro-Diaz, R., Brown, W., Brudzinski, M. R., Fraiser, M., Holt, M. M., Mori, J., Noriega, G., Scharer, K., Templeton, D., Terra, F., Williams-Stroud, S. (2021). SSA Task Force on Diversity, Equity, and Inclusion: Toward a changing, inclusive future in earthquake science, https://doi.org/10.1785/0220210170.

EDUCATION

2017–2021

Ph.D., Geophysics

UNIVERSITY OF UTAH

Advisor: Dr. Keith Koper

Dissertation Title: Seismic discrimination of earthquakes and explosions using comparisons of local magnitude (ML) and coda magnitude (MC)

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

Holt et al., in prep

ML:MC Depth Discriminant

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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. Current work is investigating different ML and MC formulations, and applying the method to historic nuclear explosions.

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Related studies:

Wang et al. (2021)

Koper et al. (2020)

Voyles et al. (2020)

Holt et al. (2019)

Koper et al. (2016)

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Github repositories:

MADPy

Magna Focal Mechanisms

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On 18 March 2020 an Mw5.6 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 5Hz 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.

Related studies:

Baker et al. (2021)

Kleber et al. (2021)

Pang et al. (2020)

Holt et al., in prep

Induced Seismicity

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In May 2015 there was an Mw4.0 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.

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Related studies:

Quinones et al. (2019)

Scales et al. (2017)

Hornbach et al. (2016)

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Download thesis

Scales et al. (2017)