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Alexandra Iezzi, Ph.D.

My research focuses on using infrasound and seismic data to study and improve monitoring of volcanic events in the Cascades. In particular, I focus on lahar/debris flow research and the development of detection, localization, and characterization algorithms for these types of events. 

Professional Experience

  • 2022 - present: Research Geophysicist, Volcano Science Center, Cascades Volcano Observatory

  • 2020 - 2022: NSF Earth Sciences Postdoctoral Fellow, University of California Santa Barbara

  • 2015 - 2020: Graduate Research Assistant, Geophysical Institute, Alaska Volcano Observatory, University of Alaska Fairbanks

  • Summer 2019: Graduate Research Assistant, Los Alamos National Laboratory 

  • Summer 2014 & 2015: Physical Science Technician (180-day appointment), Volcano Science Center, Alaska Volcano Observatory

  • Winter 2014: Research Assistant (volunteer), Volcano Science Center, Cascades Volcano Observatory 

  • 2013 - 2015: Fluvial Studies Research Assistant, Connecticut College

Education and Certifications

  • 2020 - Ph.D. in Geophysics, University of Alaska Fairbanks

  • 2015 - B.A. in Geophysics (self-designed) with minors in Mathematics and Physics, Connecticut College

Science and Products

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin.  Top plot is seismic data from the YNM station, located at the Norris Geyser Basin Museum.  Middle plot is seismic data from station YNB, in the Ragged Hills of Norris Geyser Basin. Bottom plot is infrasound data from station YNB.&nb

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin.  Top plot is seismic data from the YNM station, located at the Norris Geyser Basin Museum.  Middle plot is seismic data from station YNB, in the Ragged Hills of Norris Geyser Basin. Bottom plot is infrasound data from station YNB.&nb

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
Filter Total Items: 21

Infrasound for volcano monitoring

IntroductionVolcanic eruptions produce acoustic waves when volcanic gases and hot material rapidly expand in the atmosphere. Volcanic activity can produce acoustic signals with a wide range of frequencies, from very long period (>10 seconds) to audible (>20 hertz [Hz]), but the most energetic band is typically in the infrasound from 0.5 to 20 Hz. Studies of volcanic infrasound and the deployment o
Authors
John J. Lyons, David Fee, Weston A. Thelen, Alexandra M. Iezzi, Aaron G. Wech
By
Volcano Hazards Program, Volcano Science Center

Monitoring lahars

IntroductionLahars, or debris flows that originate from a volcano (Pierson and Scott, 1985; Pierson, 1995), are among the most destructive, far-reaching, and persistent hazards on stratovolcanoes. Lahars may be triggered by syneruptive rapid melting of snow and ice, lake breakouts, or heavy rains in conjunction with large eruptive columns. Alternatively, lahars can follow eruptions, when clastic d
Authors
Weston A. Thelen, John J. Lyons, Alexandra M. Iezzi, Seth C. Moran
By
Volcano Hazards Program, Volcano Science Center

Debris-flow monitoring on volcanoes via a novel usage of a laser rangefinder

Mount Rainier has had at least 11 large lahars over the last 6,000 years, including one occurring without evidence of eruptive activity. This prompted the creation of a lahar detection system that uses a combination of seismic, infrasound, and tripwires. We test a laser rangefinder placed on a river channel bank for detecting and confirming mass movements flowing past a station as an alternative t
Authors
Alexandra M. Iezzi, Emily H Bryant, Weston Thelen, Craig Gabrielson, Seth C. Moran, Matthew R. Patrick, Edward F. Younger, Maciej Obryk
By
Volcano Hazards Program, Volcano Science Center

Lessons learned from the 2022 CONVERSE Monogenetic Volcanism Response Scenario exercise

When volcanic unrest occurs, the scientific community can advance fundamental understanding of volcanic systems, but only with coordination before, during, and after the event across academic and governmental agencies. To develop a coordinated response plan, the Community Network for Volcanic Eruption Response (CONVERSE) orchestrated a scenario exercise centered around a hypothetical volcanic cris
Authors
Yolanda C Lin, Einat Lev, Ria Mukerji, Tobias P. Fischer, Charles B. Connor, Wendy K. Stovall, M. Poland, Alexandra M. Iezzi, Christelle Wauthier, Judit Gonzalez-Santana, Heather M. Wright, Samantha Wolf, Tobi Kasali
By
Volcano Hazards Program, Volcano Science Center

Introduction to the special section on seismoacoustics and seismoacoustic data fusion

A variety of geophysical hazards (e.g., volcanic activity, earthquakes, mass movements, marine storms, bolides) and anthropogenic sources (e.g., chemical and nuclear explosions, mining blasts, rocket launches) can release energy as mechanical waves in the ground, ocean, and atmosphere (Arrowsmith et al., 2010; Campus and Christie, 2009). Due to the mechanical coupling between a planetary body, its
Authors
Fransiska K. Dannemann Dugick, Jordan W. Bishop, Léo Martire, Alexandra M. Iezzi, Jelle D. Assink, Quentin Brissaud, Stephen Arrowsmith
By
Volcano Hazards Program, Volcano Science Center

2019 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory

The Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at 17 volcanic centers in Alaska in 2019. The most notable volcanic activity was an eruption of Shishaldin Volcano, featuring eruptive activity that produced lava flows, lahars, and ash. Weak explosive activity also took place at Great Sitkin Volcano and
Authors
Tim R. Orr, Cheryl E. Cameron, Hannah R. Dietterich, James P. Dixon, Max L. Enders, Ronni Grapenthin, Alexandra M. Iezzi, Matthew W. Loewen, John A. Power, Cheryl Searcy, Gabrielle Tepp, Liam Toney, Christopher F. Waythomas, Aaron G. Wech
By
Ecosystems Mission Area, Volcano Hazards Program, Volcano Science Center

2018 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory

The Alaska Volcano Observatory responded to eruptions, considerable and minor volcanic unrest, and seismic events at 15 volcanic centers in Alaska during 2018. The most notable volcanic activity came from Mount Cleveland, which had continuing intermittent dome growth and ash eruptions, and Mount Veniaminof, Great Sitkin Volcano, and Semisopochnoi Island, the three of which had minor eruptions. Thi
Authors
Cheryl E. Cameron, Tim R. Orr, James P. Dixon, Hannah R. Dietterich, Christopher F. Waythomas, Alexandra M. Iezzi, John A. Power, Cheryl Searcy, Ronni Grapenthin, Gabrielle Tepp, Kristi L. Wallace, Taryn M. Lopez, Kimberly Degrandpre, John M. Perreault
By
Volcano Hazards Program, Volcano Science Center

UAS-Based Observations of Infrasound Directionality at Stromboli Volcano, Italy

Infrasound (low frequency sound waves) can be used to monitor and characterize volcanic eruptions. However, infrasound sensors are usually placed on the ground, thus providing a limited sampling of the acoustic radiation pattern that can bias source size estimates. We present observations of explosive eruptions from a novel uncrewed aircraft system (UAS)-based infrasound sensor platform that was s
Authors
Alexandra M. Iezzi, Richard M. Buzard, David Fee, Robin S. Matoza, Julia E. Gestrich, A.D. Jolly, Markus Schmid, Valeria Cigala, Ulrich Kueppers, Caron E.J. Vossen, Corrado Cimarelli, Giorgio Lacanna, Maurizio Ripepe
By
Volcano Hazards Program, Volcano Science Center

Analog field-scale acoustic study of volcanic eruption directivity using a tiltable liquid nitrogen-charged water cannon

Laterally directed explosive eruptions are responsible for multiple fatalities over the past decade and are an increasingly important volcanology problem. To understand the energy dynamics for these events, we collected field-scale explosion data from nine acoustic sensors surrounding a tiltable cannon as part of an exploratory experimental design. For each cannon discharge, the blast direction wa
Authors
A.D. Jolly, Benjamin Kennedy, Robin S. Matoza, Alexandra M. Iezzi, Bruce W. Christensen, Richard Johnson, Amilea Sork, David Fee
By
Volcano Hazards Program, Volcano Science Center

Atmospheric waves and global seismoacoustic observations of the January 2022 Hunga eruption, Tonga

The 15 January 2022 climactic eruption of Hunga volcano, Tonga, produced an explosion in the atmosphere of a size that has not been documented in the modern geophysical record. The event generated a broad range of atmospheric waves observed globally by various ground-based and spaceborne instrumentation networks. Most prominent was the surface-guided Lamb wave (≲0.01 hertz), which we observed prop
Authors
Robin S. Matoza, David Fee, Jelle D. Assink, Alexandra M. Iezzi, David N. Green, Keehoon Kim, Liam Toney, Thomas Lecocq, Siddharth Krishnamoorthy, Jean-Marie Lalande, Kiwamu Nishida, Kent L. Gee, Matthew M. Haney, Hugo D. Ortiz, Quentin Brissaud, Léo Martire, Lucie Rolland, Panagiotis Vergados, Alexandra Nippress, Junghyun Park, Shahar Shani-Kadmiel, Alex Witsil, Stephen Arrowsmith, Corentin Caudron, Shingo Watada, Anna Perttu, Benoit Taisne, Pierrick Mialle, Alexis Le Pichon, Julien Vergoz, Patrick Hupe, Philip S. Blom, Roger M. Waxler, Silvio De Angelis, Jonathan Snively, Adam T. Ringler, Robert E. Anthony, A.D. Jolly, Geoff Kilgour, Gil Averbuch, Maurizio Ripepe, Mie Ichihara, Alejandra Arciniega-Ceballos, Elvira Astafyeva, Lars Ceranna, Sandrine Cevuard, Il-Young Che, Rodrigo de Negri Leiva, Carl W. Ebeling, Läslo G. Evers, Luis E. Franco-Marin, Tom Gabrielson, Katrin Hafner, R. Giles Harrison, Attila Komjathy, Giorgio Lacanna, John J. Lyons, Kenneth A. Macpherson, Emanuele Marchetti, Kathleen McKee, Rob Mellors, Gerardo Mendo-Pérez, T. Dylan Mikesell, Edhah Munaibari, Mayra Oyola-Merced, Iseul Park, Christoph Pilger, Cristina Ramos, Mario Ruiz, Roberto Sabatini, Hans Schwaiger, Dorianne Tailpied, Carrick Talmadge, Jérôme Vidot, Jeremy Webster, David C. Wilson
By
Natural Hazards Mission Area, Volcano Hazards Program, Geologic Hazards Science Center, Volcano Science Center

Evidence for near-source nonlinear propagation of volcano infrasound from Strombolian explosions at Yasur Volcano, Vanuatu

Volcanic eruption source parameters may be estimated from acoustic pressure recordings dominant at infrasonic frequencies (< 20 Hz), yet uncertainties may be high due in part to poorly understood propagation dynamics. Linear acoustic propagation of volcano infrasound is commonly assumed, but nonlinear processes such as wave steepening may distort waveforms and obscure the sourcing process in recor
Authors
Sean P Maher, Robin S Matoza, A.D. Jolly, Catherine de Groot-Hedlin, Kent L. Gee, David Fee, Alexandra M. Iezzi
By
Volcano Hazards Program, Volcano Science Center

High-rate very-long-period seismicity at Yasur volcano, Vanuatu: source mechanism and decoupling from surficial explosions and infrasound

Yasur volcano, Vanuatu is a continuously active open-vent basaltic-andesite stratocone with persistent and long-lived eruptive activity. We present results from a seismo-acoustic field experiment at Yasur, providing locally dense broad-band seismic and infrasonic network coverage from 2016 July 27 to August 3. We corroborate our seismo-acoustic observations with coincident video data from cameras
Authors
Robin S Matoza, Bernard A Chouet, A.D. Jolly, Phillip B. Dawson, Rebecca H Fitzgerald, Ben M. Kennedy, David Fee, Alexandra M. Iezzi, Geoff N Kilgour, E. Garaebiti, Sandrine Cevuard
By
Volcano Hazards Program, Volcano Science Center

Non-USGS Publications**

Iezzi, A.M., Matoza R.S., Bishop, J.W., Bhetanabhotla, S., and Fee, D. (2022), Narrow-Band Least-Squares Infrasound Array Processing, Seismological Research Letters: Electronic Seismologist, 93, 5, https://doi.org/10.1785/0220220042
Watson, L.M., Iezzi, A.M., Toney, L., Maher, S.P., Fee, D., McKee, K., Ortiz, H.D., Matoza, R.S., Anderson, J.F., Witsil, A.J.C., Gestrich, J.E., Bishop, J.W., and Johnson, J.B. (2022), Volcano Infrasound: Progress and Future Directions, Bulletin of Volcanology, 84, 44, https://doi.org/10.1007/s00445-022-01544-w
Blom, P.S., Iezzi, A.M., and Euler, G. (2020), Seismoacoustic analysis of underground explosions using the Rayleigh integral, Geophysical Journal International, 223, 1069–1085. https://doi.org/10.1093/gji/ggaa363
Iezzi, A.M., Fee, D., Kim, K., Jolly, A.D., and Matoza, R.S. (2019), Three-Dimensional Acoustic Multipole Waveform Inversion at Yasur Volcano, Vanuatu, Journal of Geophysical Research: Solid Earth, 124, 8679-8703. https://doi.org/10.1029/2018JB017073
Diaz-Moreno, A., Iezzi, A.M., Lamb, O.D., Fee, D., Kim, K., Zuccarello, L., and De Angelis, S. (2019), Volume Flow Rate Estimation for Small Explosions at Mt. Etna, Italy, From Acoustic Waveform Inversion, Geophysical Research Letters, 46, 11071-11079. https://doi.org/10.1029/2019GL084598
Jolly, A.D., Matoza, R.S., Fee, D., Kennedy, B.M., Iezzi, A.M., Fitzgerald, R.H., Austin, A.C., and Johnson, R. (2017), Capturing the Acoustic Radiation Pattern of Strombolian Eruptions using Infrasound Sensors Aboard a Tethered Aerostat, Yasur Volcano, Vanuatu. Geophysical Research Letters, 44 (19), 9672-9680. https://doi.org/10.1002/2017GL074971
Iezzi, A.M. (2020). Exploring Infrasound Wavefields to Characterize Volcanic Eruptions, Ph.D. Dissertation, University of Alaska Fairbanks, Department of Geosciences, 1-192.
Iezzi, A.M. (2015), Lahar Inundation Modeling with the Aid of Historic Flow Deposits at Redoubt Volcano, Cook Inlet, Alaska. Undergraduate Honors Thesis, Connecticut College, Department of Physics, Astronomy and Geophysics, 1-160.

**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.

Get to know CVO: Alex and Infrasound

Get to know CVO: Alex and Infrasound

At the Cascades Volcano Observatory, staff use technical skills and creativity to solve complex problems and innovate for the future. Alex Iezzi uses...

Read Article

Science and Products

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin.  Top plot is seismic data from the YNM station, located at the Norris Geyser Basin Museum.  Middle plot is seismic data from station YNB, in the Ragged Hills of Norris Geyser Basin. Bottom plot is infrasound data from station YNB.&nb

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin.  Top plot is seismic data from the YNM station, located at the Norris Geyser Basin Museum.  Middle plot is seismic data from station YNB, in the Ragged Hills of Norris Geyser Basin. Bottom plot is infrasound data from station YNB.&nb

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
Filter Total Items: 21

Infrasound for volcano monitoring

IntroductionVolcanic eruptions produce acoustic waves when volcanic gases and hot material rapidly expand in the atmosphere. Volcanic activity can produce acoustic signals with a wide range of frequencies, from very long period (>10 seconds) to audible (>20 hertz [Hz]), but the most energetic band is typically in the infrasound from 0.5 to 20 Hz. Studies of volcanic infrasound and the deployment o
Authors
John J. Lyons, David Fee, Weston A. Thelen, Alexandra M. Iezzi, Aaron G. Wech
By
Volcano Hazards Program, Volcano Science Center

Monitoring lahars

IntroductionLahars, or debris flows that originate from a volcano (Pierson and Scott, 1985; Pierson, 1995), are among the most destructive, far-reaching, and persistent hazards on stratovolcanoes. Lahars may be triggered by syneruptive rapid melting of snow and ice, lake breakouts, or heavy rains in conjunction with large eruptive columns. Alternatively, lahars can follow eruptions, when clastic d
Authors
Weston A. Thelen, John J. Lyons, Alexandra M. Iezzi, Seth C. Moran
By
Volcano Hazards Program, Volcano Science Center

Debris-flow monitoring on volcanoes via a novel usage of a laser rangefinder

Mount Rainier has had at least 11 large lahars over the last 6,000 years, including one occurring without evidence of eruptive activity. This prompted the creation of a lahar detection system that uses a combination of seismic, infrasound, and tripwires. We test a laser rangefinder placed on a river channel bank for detecting and confirming mass movements flowing past a station as an alternative t
Authors
Alexandra M. Iezzi, Emily H Bryant, Weston Thelen, Craig Gabrielson, Seth C. Moran, Matthew R. Patrick, Edward F. Younger, Maciej Obryk
By
Volcano Hazards Program, Volcano Science Center

Lessons learned from the 2022 CONVERSE Monogenetic Volcanism Response Scenario exercise

When volcanic unrest occurs, the scientific community can advance fundamental understanding of volcanic systems, but only with coordination before, during, and after the event across academic and governmental agencies. To develop a coordinated response plan, the Community Network for Volcanic Eruption Response (CONVERSE) orchestrated a scenario exercise centered around a hypothetical volcanic cris
Authors
Yolanda C Lin, Einat Lev, Ria Mukerji, Tobias P. Fischer, Charles B. Connor, Wendy K. Stovall, M. Poland, Alexandra M. Iezzi, Christelle Wauthier, Judit Gonzalez-Santana, Heather M. Wright, Samantha Wolf, Tobi Kasali
By
Volcano Hazards Program, Volcano Science Center

Introduction to the special section on seismoacoustics and seismoacoustic data fusion

A variety of geophysical hazards (e.g., volcanic activity, earthquakes, mass movements, marine storms, bolides) and anthropogenic sources (e.g., chemical and nuclear explosions, mining blasts, rocket launches) can release energy as mechanical waves in the ground, ocean, and atmosphere (Arrowsmith et al., 2010; Campus and Christie, 2009). Due to the mechanical coupling between a planetary body, its
Authors
Fransiska K. Dannemann Dugick, Jordan W. Bishop, Léo Martire, Alexandra M. Iezzi, Jelle D. Assink, Quentin Brissaud, Stephen Arrowsmith
By
Volcano Hazards Program, Volcano Science Center

2019 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory

The Alaska Volcano Observatory responded to eruptions, volcanic unrest or suspected unrest, increased seismicity, and other significant activity at 17 volcanic centers in Alaska in 2019. The most notable volcanic activity was an eruption of Shishaldin Volcano, featuring eruptive activity that produced lava flows, lahars, and ash. Weak explosive activity also took place at Great Sitkin Volcano and
Authors
Tim R. Orr, Cheryl E. Cameron, Hannah R. Dietterich, James P. Dixon, Max L. Enders, Ronni Grapenthin, Alexandra M. Iezzi, Matthew W. Loewen, John A. Power, Cheryl Searcy, Gabrielle Tepp, Liam Toney, Christopher F. Waythomas, Aaron G. Wech
By
Ecosystems Mission Area, Volcano Hazards Program, Volcano Science Center

2018 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory

The Alaska Volcano Observatory responded to eruptions, considerable and minor volcanic unrest, and seismic events at 15 volcanic centers in Alaska during 2018. The most notable volcanic activity came from Mount Cleveland, which had continuing intermittent dome growth and ash eruptions, and Mount Veniaminof, Great Sitkin Volcano, and Semisopochnoi Island, the three of which had minor eruptions. Thi
Authors
Cheryl E. Cameron, Tim R. Orr, James P. Dixon, Hannah R. Dietterich, Christopher F. Waythomas, Alexandra M. Iezzi, John A. Power, Cheryl Searcy, Ronni Grapenthin, Gabrielle Tepp, Kristi L. Wallace, Taryn M. Lopez, Kimberly Degrandpre, John M. Perreault
By
Volcano Hazards Program, Volcano Science Center

UAS-Based Observations of Infrasound Directionality at Stromboli Volcano, Italy

Infrasound (low frequency sound waves) can be used to monitor and characterize volcanic eruptions. However, infrasound sensors are usually placed on the ground, thus providing a limited sampling of the acoustic radiation pattern that can bias source size estimates. We present observations of explosive eruptions from a novel uncrewed aircraft system (UAS)-based infrasound sensor platform that was s
Authors
Alexandra M. Iezzi, Richard M. Buzard, David Fee, Robin S. Matoza, Julia E. Gestrich, A.D. Jolly, Markus Schmid, Valeria Cigala, Ulrich Kueppers, Caron E.J. Vossen, Corrado Cimarelli, Giorgio Lacanna, Maurizio Ripepe
By
Volcano Hazards Program, Volcano Science Center

Analog field-scale acoustic study of volcanic eruption directivity using a tiltable liquid nitrogen-charged water cannon

Laterally directed explosive eruptions are responsible for multiple fatalities over the past decade and are an increasingly important volcanology problem. To understand the energy dynamics for these events, we collected field-scale explosion data from nine acoustic sensors surrounding a tiltable cannon as part of an exploratory experimental design. For each cannon discharge, the blast direction wa
Authors
A.D. Jolly, Benjamin Kennedy, Robin S. Matoza, Alexandra M. Iezzi, Bruce W. Christensen, Richard Johnson, Amilea Sork, David Fee
By
Volcano Hazards Program, Volcano Science Center

Atmospheric waves and global seismoacoustic observations of the January 2022 Hunga eruption, Tonga

The 15 January 2022 climactic eruption of Hunga volcano, Tonga, produced an explosion in the atmosphere of a size that has not been documented in the modern geophysical record. The event generated a broad range of atmospheric waves observed globally by various ground-based and spaceborne instrumentation networks. Most prominent was the surface-guided Lamb wave (≲0.01 hertz), which we observed prop
Authors
Robin S. Matoza, David Fee, Jelle D. Assink, Alexandra M. Iezzi, David N. Green, Keehoon Kim, Liam Toney, Thomas Lecocq, Siddharth Krishnamoorthy, Jean-Marie Lalande, Kiwamu Nishida, Kent L. Gee, Matthew M. Haney, Hugo D. Ortiz, Quentin Brissaud, Léo Martire, Lucie Rolland, Panagiotis Vergados, Alexandra Nippress, Junghyun Park, Shahar Shani-Kadmiel, Alex Witsil, Stephen Arrowsmith, Corentin Caudron, Shingo Watada, Anna Perttu, Benoit Taisne, Pierrick Mialle, Alexis Le Pichon, Julien Vergoz, Patrick Hupe, Philip S. Blom, Roger M. Waxler, Silvio De Angelis, Jonathan Snively, Adam T. Ringler, Robert E. Anthony, A.D. Jolly, Geoff Kilgour, Gil Averbuch, Maurizio Ripepe, Mie Ichihara, Alejandra Arciniega-Ceballos, Elvira Astafyeva, Lars Ceranna, Sandrine Cevuard, Il-Young Che, Rodrigo de Negri Leiva, Carl W. Ebeling, Läslo G. Evers, Luis E. Franco-Marin, Tom Gabrielson, Katrin Hafner, R. Giles Harrison, Attila Komjathy, Giorgio Lacanna, John J. Lyons, Kenneth A. Macpherson, Emanuele Marchetti, Kathleen McKee, Rob Mellors, Gerardo Mendo-Pérez, T. Dylan Mikesell, Edhah Munaibari, Mayra Oyola-Merced, Iseul Park, Christoph Pilger, Cristina Ramos, Mario Ruiz, Roberto Sabatini, Hans Schwaiger, Dorianne Tailpied, Carrick Talmadge, Jérôme Vidot, Jeremy Webster, David C. Wilson
By
Natural Hazards Mission Area, Volcano Hazards Program, Geologic Hazards Science Center, Volcano Science Center

Evidence for near-source nonlinear propagation of volcano infrasound from Strombolian explosions at Yasur Volcano, Vanuatu

Volcanic eruption source parameters may be estimated from acoustic pressure recordings dominant at infrasonic frequencies (< 20 Hz), yet uncertainties may be high due in part to poorly understood propagation dynamics. Linear acoustic propagation of volcano infrasound is commonly assumed, but nonlinear processes such as wave steepening may distort waveforms and obscure the sourcing process in recor
Authors
Sean P Maher, Robin S Matoza, A.D. Jolly, Catherine de Groot-Hedlin, Kent L. Gee, David Fee, Alexandra M. Iezzi
By
Volcano Hazards Program, Volcano Science Center

High-rate very-long-period seismicity at Yasur volcano, Vanuatu: source mechanism and decoupling from surficial explosions and infrasound

Yasur volcano, Vanuatu is a continuously active open-vent basaltic-andesite stratocone with persistent and long-lived eruptive activity. We present results from a seismo-acoustic field experiment at Yasur, providing locally dense broad-band seismic and infrasonic network coverage from 2016 July 27 to August 3. We corroborate our seismo-acoustic observations with coincident video data from cameras
Authors
Robin S Matoza, Bernard A Chouet, A.D. Jolly, Phillip B. Dawson, Rebecca H Fitzgerald, Ben M. Kennedy, David Fee, Alexandra M. Iezzi, Geoff N Kilgour, E. Garaebiti, Sandrine Cevuard
By
Volcano Hazards Program, Volcano Science Center

Non-USGS Publications**

Iezzi, A.M., Matoza R.S., Bishop, J.W., Bhetanabhotla, S., and Fee, D. (2022), Narrow-Band Least-Squares Infrasound Array Processing, Seismological Research Letters: Electronic Seismologist, 93, 5, https://doi.org/10.1785/0220220042
Watson, L.M., Iezzi, A.M., Toney, L., Maher, S.P., Fee, D., McKee, K., Ortiz, H.D., Matoza, R.S., Anderson, J.F., Witsil, A.J.C., Gestrich, J.E., Bishop, J.W., and Johnson, J.B. (2022), Volcano Infrasound: Progress and Future Directions, Bulletin of Volcanology, 84, 44, https://doi.org/10.1007/s00445-022-01544-w
Blom, P.S., Iezzi, A.M., and Euler, G. (2020), Seismoacoustic analysis of underground explosions using the Rayleigh integral, Geophysical Journal International, 223, 1069–1085. https://doi.org/10.1093/gji/ggaa363
Iezzi, A.M., Fee, D., Kim, K., Jolly, A.D., and Matoza, R.S. (2019), Three-Dimensional Acoustic Multipole Waveform Inversion at Yasur Volcano, Vanuatu, Journal of Geophysical Research: Solid Earth, 124, 8679-8703. https://doi.org/10.1029/2018JB017073
Diaz-Moreno, A., Iezzi, A.M., Lamb, O.D., Fee, D., Kim, K., Zuccarello, L., and De Angelis, S. (2019), Volume Flow Rate Estimation for Small Explosions at Mt. Etna, Italy, From Acoustic Waveform Inversion, Geophysical Research Letters, 46, 11071-11079. https://doi.org/10.1029/2019GL084598
Jolly, A.D., Matoza, R.S., Fee, D., Kennedy, B.M., Iezzi, A.M., Fitzgerald, R.H., Austin, A.C., and Johnson, R. (2017), Capturing the Acoustic Radiation Pattern of Strombolian Eruptions using Infrasound Sensors Aboard a Tethered Aerostat, Yasur Volcano, Vanuatu. Geophysical Research Letters, 44 (19), 9672-9680. https://doi.org/10.1002/2017GL074971
Iezzi, A.M. (2020). Exploring Infrasound Wavefields to Characterize Volcanic Eruptions, Ph.D. Dissertation, University of Alaska Fairbanks, Department of Geosciences, 1-192.
Iezzi, A.M. (2015), Lahar Inundation Modeling with the Aid of Historic Flow Deposits at Redoubt Volcano, Cook Inlet, Alaska. Undergraduate Honors Thesis, Connecticut College, Department of Physics, Astronomy and Geophysics, 1-160.

**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.

Get to know CVO: Alex and Infrasound

Get to know CVO: Alex and Infrasound

At the Cascades Volcano Observatory, staff use technical skills and creativity to solve complex problems and innovate for the future. Alex Iezzi uses...

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