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Alicia J. Hotovec-Ellis, PhD

I am a volcano seismologist who is focused on improving the way we recognize, monitor, and respond to volcanic unrest. I use and develop new tools to rapidly detect and better understand seismic signals generated by volcanoes such as earthquake swarms and tremor.

I have two roles at the California Volcano Observatory (CalVO): fundamental science research on volcanic seismicity and monitoring of California’s volcanoes. My research focuses on understanding physical processes at volcanoes through the entire cycle of eruption and repose using a variety of seismological methods.

Major themes in my research are:

  • Recognition of unrest and changes in eruptive character
  • Genesis of earthquake swarms and volcanic tremor
  • Integration of interdisciplinary geophysical and geological datasets into seismic interpretations

The methods I use include waveform cross-correlation and clustering, precise relative relocation, coda wave interferometry, spectral analysis, and machine learning, among many others. I enjoy working on eruption datasets and often revisit older data to find new and unexpected observations that supplement our knowledge of what occurred and why.

I develop software for improving the way we seismically monitor volcanoes by bringing ideas from the literature into production for routine monitoring. I'm interested in the integration of interactive and automated data display so scientists responding to crises spend less time assembling data and more time interpreting it.

I lead the monitoring team at CalVO, and work with the Northern California Seismic Network to keep California’s volcanoes under constant surveillance. My goal is to ensure the necessary equipment and monitoring capabilities are already in place when the next Californian eruption occurs. I also assist other USGS volcano observatories and the Volcano Disaster Assistance Program with capacity building, data analysis, and eruption response assistance.

My interest in volcanoes began at a young age, and my career made possible through the support and mentorship of USGS scientists. As a result, I believe strongly in the value of both public outreach and mentoring for students and early career researchers.

 

Professional Experience

  • 2020-Present: Research Geophysicist, USGS California Volcano Observatory

  • 2016-2020: USGS Mendenhall Postdoctoral Fellow, Volcano Science Center

  • 2014-2016: Postdoctoral Researcher, Department of Earth and Space Sciences, University of Washington

  • 2009-2016: Duty Seismologist, Pacific Northwest Seismic Network

  • 2009-2014: Research Assistant, Department of Earth and Space Sciences, University of Washington

  • 2010: Research Geophysicist, USGS Alaska Volcano Observatory

  • 2004-2009: Physical Science Technician / Geophysicist, USGS National Earthquake Information Center

Education and Certifications

  • Doctor of Philosophy, Earth and Space Science: 2014, University of Washington, Seattle, WA

  • Master of Science, Geophysics: 2009, Colorado School of Mines, Golden, CO

  • Bachelor of Science, Geophysical Engineering: 2007, Magna Cum Laude, Colorado School of Mines, Golden, CO

Affiliations and Memberships*

  • Seismological Society of America

  • American Geophysical Union

  • International Association of Volcanoes and Chemistry of the Earth's Interior

Honors and Awards

  • David A. Johnston Award for Research Excellence, University of Washington, 2014

  • College of the Environment Dean’s Graduate Medalist, University of Washington, 2014

  • AGU Outstanding Student Paper Award (VGP Section), 2011

  • AGU Outstanding Student Paper Award (VGP Section), 2010

  • Cecil and Ida Green Award in Geophysics, Colorado School of Mines, 2007

  • Magna Cum Laude, Colorado School of Mines, 2007

  • John Moore Endowed Scholarship, Colorado School of Mines, 2003-2007

Science and Products

Time series of seismic velocity changes during the 2018 collapse of Kīlauea volcano derived from coda wave interferometry of repeating earthquakes

These processed data and provisional codes were created to investigate seismic velocity changes associated with the collapse of Kīlauea caldera during its 2018 eruption. Primary data (i.e., seismic waveforms) are hosted at the Incorporated Research Institutions for Seismology (IRIS; https://www.iris.edu/) and are ingested by the codes included here to reproduce the data analyzed in Hotovec-Ellis e
By
Volcano Science Center, Kīlauea
No results found.

Ring fault creep drives volcano-tectonic seismicity during caldera collapse of Kīlauea in 2018

Basaltic caldera collapses are episodic, producing very-long-period (VLP) earthquakes up to Mw 5.4, with prolific inter-collapse (between collapses) volcano-tectonic (VT) seismicity. During the 2018 caldera collapse of Kīlauea Volcano, VT seismicity ceased following each collapse, and then accelerated to a quasi-steady rate prior to the next collapse, marking a temporal pattern distinct from typic
Authors
Taiyi A. Wang, Paul Segall, Alicia J. Hotovec-Ellis, Kyle R. Anderson, Peter F. Cervelli
By
Volcano Hazards Program, Volcano Science Center

Volcanic earthquake catalog enhancement using integrated detection, matched-filtering, and relocation tools

Volcanic earthquake catalogs are an essential data product used to interpret subsurface volcanic activity and forecast eruptions. Advances in detection techniques (e.g., matched-filtering, machine learning) and relative relocation tools have improved catalog completeness and refined event locations. However, most volcano observatories have yet to incorporate these techniques into their catalog-bui
Authors
Darren Tan, David Fee, Alicia J. Hotovec-Ellis, J. Pesicek, Matthew M. Haney, John Power, T. Girona
By
Volcano Hazards Program, Volcano Science Center

Trends in volcano seismology: 2010 to 2020 and beyond

Volcano seismology has been fundamental to our current understanding of crustal magma migration and eruption. The increasing availability of portable seismic networks with the creative use of seismic sources and ambient noise has led to a better understanding of the volcanic structure of many volcanoes and is producing increasingly detailed images of the volcanic subsurface. The past decade (2010-
Authors
Weston Thelen, Robin Matoza, Alicia J. Hotovec-Ellis
By
Volcano Hazards Program, Volcano Science Center

Earthquake-derived seismic velocity changes during the 2018 caldera collapse of Kīlauea volcano

The 2018 Kīlauea caldera collapse produced extraordinary sequences of seismicity and deformation, with 62 episodic collapse events which significantly altered the landscape of the summit region. Despite decades of focused scientific studies at Kīlauea, detailed information about the internal structure of the volcano is limited. Recently developed techniques in seismic interferometry can be used to
Authors
Alicia J. Hotovec-Ellis, Brian Shiro, David R. Shelly, Kyle R. Anderson, Matt Haney, Weston Thelen, Emily Montgomery-Brown, Ingrid Johanson
By
Volcano Hazards Program, Volcano Science Center

Seismic and geodetic progression of the 2018 summit caldera collapse of Kīlauea Volcano

The 2018 eruption of Kīlauea volcano, Hawaiʻi, resulted in a major collapse of the summit caldera along with an effusive eruption in the lower East Rift Zone. The caldera collapse comprised 62 highly similar collapse cycles of strong ground deformation and earthquake swarms that ended with a magnitude 5 collapse event and one partial cycle that did not end with a collapse event. We analyzed geodet
Authors
Gabrielle Tepp, Alicia J. Hotovec-Ellis, Brian Shiro, Ingrid Johanson, Weston Thelen, Matthew M. Haney
By
Natural Hazards Mission Area, Volcano Hazards Program, Volcano Science Center

Deep fluid pathways beneath Mammoth Mountain, California, illuminated by migrating earthquake swarms

Although most volcanic seismicity is shallow (within several kilometers of the surface), some volcanoes exhibit deeper seismicity (10 to 30+ km) that may reflect active processes such as magma resupply and volatile transfer. One such volcano is Mammoth Mountain, California, which has also recently exhibited high rates of CO2 discharge at the surface. We perform high-resolution earthquake detection
Authors
Alicia J. Hotovec-Ellis, David R. Shelly, David P. Hill, Andrew M. Pitt, Phillip B. Dawson, Bernard A. Chouet
By
Volcano Hazards Program, Volcano Science Center

Non-USGS Publications**

Hotovec-Ellis, A.J., Bodin, P., Thelen, W., Okubo, P., and Vidale, J.E., 2017. Improving the Hawaiian Seismic Network for Earthquake Early Warning, Seism. Res. Lett., 88, pp. 326-334, doi:10.1785/0220160187.
Thelen, W.A., Hotovec-Ellis, A.J., and Bodin, P., 2016. Feasibility study of earthquake early warning (EEW) in Hawaiʻi. U.S. Geological Survey Open-File Report 2016-1172, 33 p., http://dx.doi.org/10.3133/ofr20161172.
Hotovec-Ellis, A. J., Vidale, J. E., Gomberg, J., Thelen, W., and Moran, S. C., 2015. Changes in seismic velocity during the first 14 months of the 2004–2008 eruption of Mount St. Helens, Washington, J. Geophys. Res., 120, pp. 6226-6240, doi:10.1002/2015JB012101.
Haney, M., Hotovec-Ellis, A.J., Bennington, N.L., De Angelis, S., and Thurber, C., 2015. Tracking changes in volcanic systems with seismic interferometry, in Encyclopedia of Earthquake Engineering, edited by M. Beer et al., pp. 1-23, Springer, doi:10.1007/978-3-642-36197-5_50-1.
Hotovec-Ellis, A.J., Gomberg, J.S., Vidale, J.E., and Creager, K.C., 2014. A continuous record of inter-eruption velocity change at Mount St. Helens from coda-wave interferometry, J. Geophys. Res., 119, pp. 2199–2214, doi:10.1002/2013JB010742.
Vidale, J.E., Malone, S.D., Hotovec-Ellis, A.J., Moran, S.C., Creager, K.C., Houston, H., and Schmidt, D.A., 2013. Deep long-period earthquakes west of the volcanic arc in Oregon: Direct evidence of fluid migration through the forearc mantle wedge, Geophys. Res. Lett., pp. 370-376, doi:10.1002/2013GL059118.
Dmetrieva, K., Hotovec-Ellis, A.J., Prejean, S.G., and Dunham, E.M., 2013. Frictional faulting model for silenced harmonic tremor prior to Redoubt Volcano eruptions. Nature Geoscience 6(8), pp. 652-656, doi:10.1038/ngeo1879.
Hotovec, A.J., Prejean, S.G., Vidale, J.E., and Gomberg, J.S., 2013. Strongly Gliding Harmonic Tremor During the 2009 Eruption of Redoubt Volcano. J. Volcan. Geotherm. Res. (Redoubt Special Issue) 259, pp. 89-99, doi:10.1016/jvolgeores.2012.01.001.
Gomberg, J., Creager, K., Sweet, J., Vidale, J., Ghosh, A., and Hotovec, A., 2012. Earthquake spectra and near-source attenuation in the Cascadia subduction zone. J. Geophys. Res. 117, B05312, 12 p., doi:10.1029/2011JB009055.
Vidale, J.E., Hotovec, A.J., Ghosh, A., Creager, K.C., and Gomberg, J.S., 2011. Tiny intraplate earthquakes triggered by nearby episodic tremor and slip in Cascadia. Geochem. Geophys. Geosyst. 12(6), Q06005, 8 p., doi:10.1029/2011GC003559.
Allen, T.I., Wald, D.J., Earle, P.S., Marano, K.D., Hotovec, A.J., Lin, K., and Hearne, M., 2009. An Atlas of ShakeMaps and population exposure catalog for earthquake loss modeling. Bull. Earthq. Eng. 7(3), pp. 701-718, doi: 10.1007/s10518-009-9120-y.
Earle, P.S, Wald, D.J., Jaiswal, K.S., Allen, T.I., Marano, K.D., Hotovec, A.J., Hearne, M.G., and Fee. J.M., 2009. Prompt Assessment of Global Earthquakes for Response (PAGER): A system for rapidly determining the impact of earthquakes worldwide. U.S. Geological Survey Open-File Report 2009-1131, 15 p.
Allen, T.I., Wald, D.J., Hotovec, A.J., Lin, K., Earle, P.S., and Marano, K.D., 2008. An Atlas of ShakeMaps for selected global earthquakes. U.S. Geological Survey Open-File Report 2008-1236, 47 p. 2008

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

REDPy - Repeating Earthquake Detector in Python (Version 1.0.0)

REDPy (Repeating Earthquake Detector in Python) is a tool for automated detection and analysis of repeating earthquakes in continuous data. It works without any previous assumptions of what repeating seismicity looks like (that is, does not require a template event). Repeating earthquakes are clustered into families based on waveform similarity via cross-correlation across multiple stations. All d
By
Volcano Science Center
link

The Mystery of the Noon Booms Part 2

In last week's post (https://www.usgs.gov/observatories/calvo/news/mystery-noon-booms-part-1), we challenged you to give us your best hypotheses as to...

Read Article
link

The Mystery of the Noon Booms: Part 1

Just in time for the Fourth of July, CalVO scientists have been seeing some interesting - but unusual - acoustic signals on our seismometers. 

Read Article

Science and Products

  • Data

    Time series of seismic velocity changes during the 2018 collapse of Kīlauea volcano derived from coda wave interferometry of repeating earthquakes

    These processed data and provisional codes were created to investigate seismic velocity changes associated with the collapse of Kīlauea caldera during its 2018 eruption. Primary data (i.e., seismic waveforms) are hosted at the Incorporated Research Institutions for Seismology (IRIS; https://www.iris.edu/) and are ingested by the codes included here to reproduce the data analyzed in Hotovec-Ellis e
    By
    Volcano Science Center, Kīlauea
  • Multimedia
    No results found.
  • Publications

    Ring fault creep drives volcano-tectonic seismicity during caldera collapse of Kīlauea in 2018

    Basaltic caldera collapses are episodic, producing very-long-period (VLP) earthquakes up to Mw 5.4, with prolific inter-collapse (between collapses) volcano-tectonic (VT) seismicity. During the 2018 caldera collapse of Kīlauea Volcano, VT seismicity ceased following each collapse, and then accelerated to a quasi-steady rate prior to the next collapse, marking a temporal pattern distinct from typic
    Authors
    Taiyi A. Wang, Paul Segall, Alicia J. Hotovec-Ellis, Kyle R. Anderson, Peter F. Cervelli
    By
    Volcano Hazards Program, Volcano Science Center

    Volcanic earthquake catalog enhancement using integrated detection, matched-filtering, and relocation tools

    Volcanic earthquake catalogs are an essential data product used to interpret subsurface volcanic activity and forecast eruptions. Advances in detection techniques (e.g., matched-filtering, machine learning) and relative relocation tools have improved catalog completeness and refined event locations. However, most volcano observatories have yet to incorporate these techniques into their catalog-bui
    Authors
    Darren Tan, David Fee, Alicia J. Hotovec-Ellis, J. Pesicek, Matthew M. Haney, John Power, T. Girona
    By
    Volcano Hazards Program, Volcano Science Center

    Trends in volcano seismology: 2010 to 2020 and beyond

    Volcano seismology has been fundamental to our current understanding of crustal magma migration and eruption. The increasing availability of portable seismic networks with the creative use of seismic sources and ambient noise has led to a better understanding of the volcanic structure of many volcanoes and is producing increasingly detailed images of the volcanic subsurface. The past decade (2010-
    Authors
    Weston Thelen, Robin Matoza, Alicia J. Hotovec-Ellis
    By
    Volcano Hazards Program, Volcano Science Center

    Earthquake-derived seismic velocity changes during the 2018 caldera collapse of Kīlauea volcano

    The 2018 Kīlauea caldera collapse produced extraordinary sequences of seismicity and deformation, with 62 episodic collapse events which significantly altered the landscape of the summit region. Despite decades of focused scientific studies at Kīlauea, detailed information about the internal structure of the volcano is limited. Recently developed techniques in seismic interferometry can be used to
    Authors
    Alicia J. Hotovec-Ellis, Brian Shiro, David R. Shelly, Kyle R. Anderson, Matt Haney, Weston Thelen, Emily Montgomery-Brown, Ingrid Johanson
    By
    Volcano Hazards Program, Volcano Science Center

    Seismic and geodetic progression of the 2018 summit caldera collapse of Kīlauea Volcano

    The 2018 eruption of Kīlauea volcano, Hawaiʻi, resulted in a major collapse of the summit caldera along with an effusive eruption in the lower East Rift Zone. The caldera collapse comprised 62 highly similar collapse cycles of strong ground deformation and earthquake swarms that ended with a magnitude 5 collapse event and one partial cycle that did not end with a collapse event. We analyzed geodet
    Authors
    Gabrielle Tepp, Alicia J. Hotovec-Ellis, Brian Shiro, Ingrid Johanson, Weston Thelen, Matthew M. Haney
    By
    Natural Hazards Mission Area, Volcano Hazards Program, Volcano Science Center

    Deep fluid pathways beneath Mammoth Mountain, California, illuminated by migrating earthquake swarms

    Although most volcanic seismicity is shallow (within several kilometers of the surface), some volcanoes exhibit deeper seismicity (10 to 30+ km) that may reflect active processes such as magma resupply and volatile transfer. One such volcano is Mammoth Mountain, California, which has also recently exhibited high rates of CO2 discharge at the surface. We perform high-resolution earthquake detection
    Authors
    Alicia J. Hotovec-Ellis, David R. Shelly, David P. Hill, Andrew M. Pitt, Phillip B. Dawson, Bernard A. Chouet
    By
    Volcano Hazards Program, Volcano Science Center

    Non-USGS Publications**

    Hotovec-Ellis, A.J., Bodin, P., Thelen, W., Okubo, P., and Vidale, J.E., 2017. Improving the Hawaiian Seismic Network for Earthquake Early Warning, Seism. Res. Lett., 88, pp. 326-334, doi:10.1785/0220160187.
    Thelen, W.A., Hotovec-Ellis, A.J., and Bodin, P., 2016. Feasibility study of earthquake early warning (EEW) in Hawaiʻi. U.S. Geological Survey Open-File Report 2016-1172, 33 p., http://dx.doi.org/10.3133/ofr20161172.
    Hotovec-Ellis, A. J., Vidale, J. E., Gomberg, J., Thelen, W., and Moran, S. C., 2015. Changes in seismic velocity during the first 14 months of the 2004–2008 eruption of Mount St. Helens, Washington, J. Geophys. Res., 120, pp. 6226-6240, doi:10.1002/2015JB012101.
    Haney, M., Hotovec-Ellis, A.J., Bennington, N.L., De Angelis, S., and Thurber, C., 2015. Tracking changes in volcanic systems with seismic interferometry, in Encyclopedia of Earthquake Engineering, edited by M. Beer et al., pp. 1-23, Springer, doi:10.1007/978-3-642-36197-5_50-1.
    Hotovec-Ellis, A.J., Gomberg, J.S., Vidale, J.E., and Creager, K.C., 2014. A continuous record of inter-eruption velocity change at Mount St. Helens from coda-wave interferometry, J. Geophys. Res., 119, pp. 2199–2214, doi:10.1002/2013JB010742.
    Vidale, J.E., Malone, S.D., Hotovec-Ellis, A.J., Moran, S.C., Creager, K.C., Houston, H., and Schmidt, D.A., 2013. Deep long-period earthquakes west of the volcanic arc in Oregon: Direct evidence of fluid migration through the forearc mantle wedge, Geophys. Res. Lett., pp. 370-376, doi:10.1002/2013GL059118.
    Dmetrieva, K., Hotovec-Ellis, A.J., Prejean, S.G., and Dunham, E.M., 2013. Frictional faulting model for silenced harmonic tremor prior to Redoubt Volcano eruptions. Nature Geoscience 6(8), pp. 652-656, doi:10.1038/ngeo1879.
    Hotovec, A.J., Prejean, S.G., Vidale, J.E., and Gomberg, J.S., 2013. Strongly Gliding Harmonic Tremor During the 2009 Eruption of Redoubt Volcano. J. Volcan. Geotherm. Res. (Redoubt Special Issue) 259, pp. 89-99, doi:10.1016/jvolgeores.2012.01.001.
    Gomberg, J., Creager, K., Sweet, J., Vidale, J., Ghosh, A., and Hotovec, A., 2012. Earthquake spectra and near-source attenuation in the Cascadia subduction zone. J. Geophys. Res. 117, B05312, 12 p., doi:10.1029/2011JB009055.
    Vidale, J.E., Hotovec, A.J., Ghosh, A., Creager, K.C., and Gomberg, J.S., 2011. Tiny intraplate earthquakes triggered by nearby episodic tremor and slip in Cascadia. Geochem. Geophys. Geosyst. 12(6), Q06005, 8 p., doi:10.1029/2011GC003559.
    Allen, T.I., Wald, D.J., Earle, P.S., Marano, K.D., Hotovec, A.J., Lin, K., and Hearne, M., 2009. An Atlas of ShakeMaps and population exposure catalog for earthquake loss modeling. Bull. Earthq. Eng. 7(3), pp. 701-718, doi: 10.1007/s10518-009-9120-y.
    Earle, P.S, Wald, D.J., Jaiswal, K.S., Allen, T.I., Marano, K.D., Hotovec, A.J., Hearne, M.G., and Fee. J.M., 2009. Prompt Assessment of Global Earthquakes for Response (PAGER): A system for rapidly determining the impact of earthquakes worldwide. U.S. Geological Survey Open-File Report 2009-1131, 15 p.
    Allen, T.I., Wald, D.J., Hotovec, A.J., Lin, K., Earle, P.S., and Marano, K.D., 2008. An Atlas of ShakeMaps for selected global earthquakes. U.S. Geological Survey Open-File Report 2008-1236, 47 p. 2008

    **Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

  • Software

    REDPy - Repeating Earthquake Detector in Python (Version 1.0.0)

    REDPy (Repeating Earthquake Detector in Python) is a tool for automated detection and analysis of repeating earthquakes in continuous data. It works without any previous assumptions of what repeating seismicity looks like (that is, does not require a template event). Repeating earthquakes are clustered into families based on waveform similarity via cross-correlation across multiple stations. All d
    By
    Volcano Science Center
  • News
    link

    The Mystery of the Noon Booms Part 2

    In last week's post (https://www.usgs.gov/observatories/calvo/news/mystery-noon-booms-part-1), we challenged you to give us your best hypotheses as to...

    Read Article
    link

    The Mystery of the Noon Booms: Part 1

    Just in time for the Fourth of July, CalVO scientists have been seeing some interesting - but unusual - acoustic signals on our seismometers. 

    Read Article

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government