Graduation Year

2022

Graduation Month

May

Document Type

Thesis

Degree Name

Bachelor of Science

School or Department

Geosciences

Major

Geosciences

Faculty Mentor

Dr. Hilary R. Martens

Faculty Mentor Department

Geosciences

Keywords

montana earthquake record, seismicity, Python, aftershocks

Subject Categories

Computer Sciences | Earth Sciences | Geology | Geophysics and Seismology

Abstract

The Rocky Mountains of western Montana have long been experiencing tectonic compression and extension that has shaped much of western North America. This activity consistently produces seismic events, like the 6 July 2017 M 5.8 earthquake 11 km southeast of Lincoln, MT, which can be used to advance understanding of crust and mantle dynamics and structure. Seismic mapping is vital to understanding structure and tectonic activity in western Montana as well as in analogous locations across the world. Recently deployed seismometers from the University of Montana as well as the Montana Regional Seismic Network (MRSN) from the Montana Bureau of Mines and Geology (MBMG) and temporary stations from the United States Geological Survey (USGS) have been collecting continuous data for several years that can be analyzed using the QuakeMigrate software. Continuous waveform data from the University of Montana Seismic Network (UMSN) has not previously been searched for earthquakes (outside of the USGS event catalog) and potentially contains hundreds or thousands of additional small seismic events not previously detected by the more sparsely distributed regional networks. An updated catalog, based on the concentrated deployment of UMSN stations around the Lincoln aftershock sequence, will allow for an updated structural analysis of west-central Montana with unprecedented precision, as well as detailed analyses of aftershock evolution and crustal stress state. Large events, like the Lincoln, Montana event in 2017, garner significant attention but are rare. Smaller events, while they may not be felt at the surface or even register in some seismometers, are much more common and therefore can provide a more thorough understanding of the Earth’s subsurface dynamics and structure, thus motivating the need for a detailed catalog. We are currently using QuakeMigrate to create an earthquake catalog using data from the 12 stations in the UMSN, stations from the MRSN, and temporary USGS stations near Lincoln to detect and locate aftershocks following the M 5.8 Lincoln, Montana mainshock. The catalog will include origin times, hypocentral locations, and magnitudes of earthquakes that have occurred since the Lincoln, Montana mainshock on 6 July 2017. This catalog aims to provide accessible seismic event data for west-central Montana beginning on 6 July 2017 until the conclusion of 2021.

Honors College Research Project

No

GLI Capstone Project

no

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