I have a wide-ranging set of research interests that stem from my background in both seismology and atmospheric acoustics, and from my experience working at both national laboratories and academia. I’ve been fortunate to work with a lot of really smart people from across a breadth of disciplines including physics, mathematics, statistics, computer science, engineering, and earth sciences. My experiences of collaborating across disciplines constantly informs my research interests, and I try to borrow and apply things I learn in one place to new problems.
01 Algorithms & Data
Measurements and data are our window into the natural world. I love finding ways to analyze data in order to learn new things about Earth. While it’s always fun to go out and make new measurements (and sometimes it’s absolutely necessary!), I particularly enjoy developing new ways to process data in order to make new discoveries. Much of my work has been on developing algorithms for processing seismic and geoacoustic data in smarter ways. This work has focused on exploring ways to detect new types of signal, or entirely new events. More efficient algorithms can also help for problems that require extensive human interaction and review; reducing analyst workloads and enabling the processing of more data.

A Data Driven Framework for Automated Detection of Aircraft Generated Signals in Seismic Array Data Using Machine Learning
Zhang, Xinxiang and Arrowsmith, Stephen and Tsongas, Sotirios and Hayward, Chris and Meng, Haoran and Ben-Zion, Yehuda
BibTeX

Big Data Seismology
Arrowsmith, Stephen and Trugman, Daniel and MacCarthy, Jonathan and Bergen, Karianne and Lumley, David and Magnani, Beatrice
BibTeX

Implementation of the Waveform Correlation Event Detection System (WCEDS) Method for Regional Seismic Event Detection in Utah
Arrowsmith, Stephen and Young, Christopher and Pankow, Kristine
BibTeX

Multivariate acoustic detection of small explosions using Fisher’s combined probability test
Arrowsmith, Stephen J and Taylor, Steven R
BibTeX
02 Geophysical Inverse Theory
In Geophysics, we often make use of grossly limited and insufficient data to understand complex Earth structures or processes. Inverse theory provides us with the tools to use our limited data to make meaningful inferences about the Earth, while formally understanding the uncertainty in our models. My PhD was based on a classic Geophysical inverse theory problem – seismic tomography – which is the inference of 3D Earth structure from measurements of seismic waves. I learnt first-hand about the challenge of limited datasets! My interest in atmospheric acoustics subsequently required me to consider even harder inverse problems, and to come to terms with Bayesian methods as a more thorough means to assess uncertainty. While it might sound boring, getting inverse theory right is the key to any assessment of the Earth from limited data. In particular, I have an ongoing interest in how we can characterize uncertainty, and how that informs our understanding of Earth.

Event Location with Sparse Data: When Probabilistic Global Search is Important
Stephen Arrowsmith; Junghyun Park; Il‐Young Che; Brian Stump; Gil Averbuch
BibTeX

Locating Surface Explosions by Combining Seismic and Infrasound Data
Koch, Clinton D and Arrowsmith, Stephen
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A framework for estimating stratospheric wind speeds from unknown sources and application to the 2010 December 25 bolide
Arrowsmith, Stephen J and Marcillo, Omar and Drob, Douglas P
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Seismic imaging of a hot upwelling beneath the British Isles
Arrowsmith, Stephen J and Kendall, Michael and White, Nicky and VanDecar, John C and Booth, David C
BibTeX
03 Geoacoustic Sources & Propagation
Volcanoes, earthquakes, bolides, ocean activity, and a wide-variety of human caused signals can generate geoacoustic waves. These waves propagate through the atmosphere and can be detected at long distances. A particular interest of mine is how we can use geoacoustic waves to understand either sources, or the propagation through a dynamic atmosphere.

Illuminating the North Korean nuclear explosion test in 2017 using remote infrasound observations
Che, Il-Young and Kim, Keehoon and Le Pichon, Alexis and Park, Junghyun and Arrowsmith, Stephen and Stump, Brian
BibTeX

Evidence for Short Temporal Atmospheric Variations Observed by Infrasonic Signals: 1. The Troposphere
Averbuch, Gil and Ronac-Giannone, Miro and Arrowsmith, Stephen and Anderson, Jake
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On infrasound generated by wind farms and its propagation in low-altitude tropospheric waveguides
Marcillo, Omar and Arrowsmith, Stephen and Blom, Philip and Jones, Kyle
BibTeX
04 Forensic Seismology & Acoustics
I have a long-standing interest in the use of seismology and acoustics to monitor human sources for national and international security. I’ve worked on several programs at the national laboratories on developing algorithms and tools for national and international agencies to aid in the ability to detect, locate, and characterize human sources. Many people don’t associate Earth Science with these applications, but I find it an interesting and important application of our science!

Persistent, “Mysterious” Seismoacoustic Signals Reported in Oklahoma State during 2019
Carmichael, Josh and Thiel, Andrew and Blom, Philip and Walter, Jacob and Dannemann, Fransiska and Arrowsmith, Stephen and Carr, Chris
BibTeX

Bolide Energetics and Infrasound Propagation: Exploring the 18 December 2018 Bering Sea Event to Identify Limitations of Empirical and Numerical Models
Arrowsmith, Stephen and Negraru, Petru and Johnson, Greg
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False alarms and the IMS infrasound network: Understanding the factors influencing the creation of false events
Arrowsmith, Stephen J
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Explosion yield estimation from pressure wave template matching
Arrowsmith, Stephen and Bowman, Daniel