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Aaron Wech

My research focuses on developing techniques for tracking non-earthquake seismicity. By applying these techniques to seismic data across broad spatial and temporal scales, I analyze the patterns to investigate underlying earthquake and volcano source processes. I incorporate these techniques into automatic monitoring and alarm systems for regional seismic networks and volcano observatories.

Professional Experience

  • 2015 – present - Research Geophysicist, Volcano Science Center, U.S. Geological Survey, Anchorage, AK

  • 2013 – 2015 - Mendenhall Postdoctoral Fellow, Volcano Science Center, U.S. Geological Survey, Anchorage, AK

  • 2010 – 2013 - Postdoctoral Fellow, Victoria University of Wellington, New Zealand

Education and Certifications

  • 2010 – Ph.D. Geophysics, University of Washington, Seattle, WA

  • 2005 – B.S. Mathematics & Physics, Kansas State University, Manhattan, KS

Science and Products

link
Image: Geologic Studies on Sitkinak Island, Alaska

Alaska-Aleutian Subduction Zone Studies

Our research team is exploring seismic and aseismic slip along the Alaska-Aleutian arc and studying the prehistoric record of megathrust earthquakes and tsunamis along the Alaska-Aleutian subduction zone Seismic and Aseismic Slip : Tectonic tremor and associated slow slip events represent a newly discovered part of the earthquake cycle. This research aims to understand the process generating...
By
Alaska Science Center
link

Alaska-Aleutian Subduction Zone Studies

Our research team is exploring seismic and aseismic slip along the Alaska-Aleutian arc and studying the prehistoric record of megathrust earthquakes and tsunamis along the Alaska-Aleutian subduction zone Seismic and Aseismic Slip : Tectonic tremor and associated slow slip events represent a newly discovered part of the earthquake cycle. This research aims to understand the process generating...
Learn More
Filter Total Items: 27

Seismic techniques and suggested instrumentation to monitor volcanoes

IntroductionChanges in the pressure or location of magma can stress or break surrounding rocks and trigger flow of nearby waters and gases, causing seismic signals, such as discrete earthquakes and tremor. These phenomena are types of seismic unrest that commonly precede eruption and can be used to forecast volcanic activity. Mass movements at the surface, including avalanches, debris flows, and l
Authors
Weston A. Thelen, John J. Lyons, Aaron G. Wech, Seth C. Moran, Matthew M. Haney, Ashton F. Flinders
By
Volcano Hazards Program, Volcano Science Center

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

From field station to forecast: Managing data at the Alaska Volcano Observatory

The Alaska Volcano Observatory (AVO) uses multidisciplinary data to monitor and study dozens of active and potentially active volcanoes. Here, we provide an overview of internally and externally generated data types, tools and resources used in their management, and challenges faced. Data sources include the following: (1) a multiparameter (seismic, infrasound, GNSS, web cameras) ground-based moni
Authors
Michelle L. Coombs, Cheryl Cameron, Hannah R. Dietterich, Eleanor Boyce, Aaron Wech, Ronni Grapenthin, Kristi L. Wallace, Thomas Parker, Taryn Lopez, Scott Crass, David Fee, Matthew M. Haney, Dane M. Ketner, Matthew W. Loewen, John J. Lyons, Jenny Sha Nakai, John Power, Steven M Botnick, Israel Brewster, Max L. Enders, Dain Harmon, Peter J. Kelly, Michael J. Randall
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

Return from dormancy: Rapid inflation and seismic unrest driven by transcrustal magma transfer at Mt. Edgecumbe (L’´ux Shaa) Volcano, Alaska

In April 2022, a seismic swarm near Mt. Edgecumbe in southeast Alaska suggested renewed activity at this transform fault volcano, which was last active ≈800 years ago. Previously, thin rhyolitic tephras were deposited 5 and 4 ka. Satellite radar data from 2014 to 2022 resolves line-of-sight rapid inflation up to 7.1 cm/yr beginning in August 2018. Bayesian modeling suggests a transcrustal system o
Authors
R. Grapenthin, Yitian Cheng, Mario Angarita, Darren Tan, Franz J. Meyer, David Fee, Aaron Wech
By
Volcano Hazards Program, Volcano Science Center

Cataloging tectonic tremor energy radiation in the Cascadia subduction zone

For the past ∼12 years the Pacific Northwest Seismic Network has been automatically detecting and locating tectonic tremor across the Cascadia subduction zone, resulting in a catalog of more than 500,000 tremor epicenters to date, which has served as a valuable resource for tremor and slip research. This manuscript presents an updated methodology for routine tremor detection in Cascadia and a new
Authors
Aaron Wech
By
Volcano Hazards Program, Volcano Science Center

Deep long-period earthquakes generated by second boiling beneath Mauna Kea volcano

Deep long-period earthquakes (DLPs) are an enigmatic type of volcanic seismicity that sometimes precedes eruptions but mostly occurs at quiescent volcanoes. These earthquakes are depleted in high-frequency content and typically occur near the base of the crust. We observed a near-periodic, long- lived sequence of more than one million DLPs in the past 19 years beneath the dormant postshield Mauna
Authors
Aaron Wech, Weston Thelen, Amanda Thomas
By
Volcano Hazards Program, Volcano Science Center

Infrasound generated by the 2016-2017 shallow submarine eruption of Bogoslof volcano, Alaska

The 2016–2017 shallow submarine eruption of Bogoslof volcano produced numerous infrasound signals over 9 months that were recorded on six Alaska Volcano Observatory (AVO) arrays at ranges of 59 to over 800 km from the volcano. The lack of geophysical monitoring near Bogoslof and the repeated production of volcanic clouds to flight levels made monitoring by remote infrasound critical during the eru
Authors
John J. Lyons, Alexandra M. Iezzi, David Fee, Hans Schwaiger, Aaron Wech, Matthew M. Haney
By
Volcano Hazards Program, Volcano Science Center

Upper plate heterogeneity along the Southern Hikurangi Margin, New Zealand

Controlled and natural source seismic data are used to build a 3-D P wave model for southern North Island, New Zealand, where the Pacific Plate subducts beneath the Australian Plate at a rate of ~41 mm/year. Our analysis reveals an abrupt along-strike transition in overthrusting plate structure within Cook Strait. Contrasts in properties (Vp, Vp/Vs, and Qs) likely reflects the degree of deformatio
Authors
Stuart Henrys, Donna Eberhart-Phillips, Dan Bassett, Rupert Sutherland, David Okaya, Martha Savage, Dominic Evanzia, Tim A. Stern, Hiroshi Sato, Kimihiro Mochizuki, Takaya Iwasaki, Eiji Kurashimo, Anya Seward, Aaron Wech
By
Volcano Hazards Program, Volcano Science Center

Constraints on eruption processes and event masses for the 2016–2017 eruption of Bogoslof volcano, Alaska, through evaluation of IASI satellite SO2 masses and complementary datasets

Bogoslof volcano, Alaska, experienced at least 70 explosive eruptions between 12 December 2016 and 31 August 2017. Due to its remote location and limited local monitoring network, this eruption was monitored and characterized primarily using remote geophysical and satellite techniques. SO2 emissions from Bogoslof were persistently detected by the Infrared Atmospheric Sounding Interferometer (IASI)
Authors
Taryn Lopez, Lieven Clarisse, Hans Schwaiger, Alexa R. Van Eaton, Matthew W. Loewen, David Fee, John J. Lyons, Kristi L. Wallace, Cheryl Searcy, Aaron Wech, Matthew M. Haney, David J. Schneider, Nathan Graham
By
Volcano Hazards Program, Volcano Science Center

Seismo-acoustic evidence for vent drying during shallow submarine eruptions at Bogoslof volcano, Alaska

Characterizing the state of the volcanic vent is key for interpreting observational datasets and accurately assessing volcanic hazards. This is particularly true for remote, complex eruptions such as the 2016–2017 Bogoslof volcano, Alaska eruption sequence. Bogoslof’s eruptions in this period were either shallow submarine or subaerial, or some combination of both. Our results demonstrate how low-f
Authors
David Fee, John J. Lyons, Matthew M. Haney, Aaron Wech, Christopher F. Waythomas, Angela K. Diefenbach, Taryn Lopez, Alexa R. Van Eaton, David J. Schneider
By
Volcano Hazards Program, Volcano Science Center

Overview, chronology, and impacts of the 2016–2017 eruption of Bogoslof volcano, Alaska

The 2016–2017 eruption of Bogoslof volcano, a back-arc shallow submarine volcano in Alaska’s Aleutian arc, began in December 2016 and included 70 explosive events and at least two episodes of subaerial dome building. Because the volcano had no local monitoring stations during the eruption, a combination of distant seismic stations, regional infrasound sensors, lightning detection, a variety of sat
Authors
Michelle L. Coombs, Kristi L. Wallace, Cheryl Cameron, John J. Lyons, Aaron Wech, Kim M. Angeli, Peter Cervelli
By
Volcano Hazards Program, Volcano Science Center

Science and Products

link
Image: Geologic Studies on Sitkinak Island, Alaska

Alaska-Aleutian Subduction Zone Studies

Our research team is exploring seismic and aseismic slip along the Alaska-Aleutian arc and studying the prehistoric record of megathrust earthquakes and tsunamis along the Alaska-Aleutian subduction zone Seismic and Aseismic Slip : Tectonic tremor and associated slow slip events represent a newly discovered part of the earthquake cycle. This research aims to understand the process generating...
By
Alaska Science Center
link

Alaska-Aleutian Subduction Zone Studies

Our research team is exploring seismic and aseismic slip along the Alaska-Aleutian arc and studying the prehistoric record of megathrust earthquakes and tsunamis along the Alaska-Aleutian subduction zone Seismic and Aseismic Slip : Tectonic tremor and associated slow slip events represent a newly discovered part of the earthquake cycle. This research aims to understand the process generating...
Learn More
Filter Total Items: 27

Seismic techniques and suggested instrumentation to monitor volcanoes

IntroductionChanges in the pressure or location of magma can stress or break surrounding rocks and trigger flow of nearby waters and gases, causing seismic signals, such as discrete earthquakes and tremor. These phenomena are types of seismic unrest that commonly precede eruption and can be used to forecast volcanic activity. Mass movements at the surface, including avalanches, debris flows, and l
Authors
Weston A. Thelen, John J. Lyons, Aaron G. Wech, Seth C. Moran, Matthew M. Haney, Ashton F. Flinders
By
Volcano Hazards Program, Volcano Science Center

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

From field station to forecast: Managing data at the Alaska Volcano Observatory

The Alaska Volcano Observatory (AVO) uses multidisciplinary data to monitor and study dozens of active and potentially active volcanoes. Here, we provide an overview of internally and externally generated data types, tools and resources used in their management, and challenges faced. Data sources include the following: (1) a multiparameter (seismic, infrasound, GNSS, web cameras) ground-based moni
Authors
Michelle L. Coombs, Cheryl Cameron, Hannah R. Dietterich, Eleanor Boyce, Aaron Wech, Ronni Grapenthin, Kristi L. Wallace, Thomas Parker, Taryn Lopez, Scott Crass, David Fee, Matthew M. Haney, Dane M. Ketner, Matthew W. Loewen, John J. Lyons, Jenny Sha Nakai, John Power, Steven M Botnick, Israel Brewster, Max L. Enders, Dain Harmon, Peter J. Kelly, Michael J. Randall
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

Return from dormancy: Rapid inflation and seismic unrest driven by transcrustal magma transfer at Mt. Edgecumbe (L’´ux Shaa) Volcano, Alaska

In April 2022, a seismic swarm near Mt. Edgecumbe in southeast Alaska suggested renewed activity at this transform fault volcano, which was last active ≈800 years ago. Previously, thin rhyolitic tephras were deposited 5 and 4 ka. Satellite radar data from 2014 to 2022 resolves line-of-sight rapid inflation up to 7.1 cm/yr beginning in August 2018. Bayesian modeling suggests a transcrustal system o
Authors
R. Grapenthin, Yitian Cheng, Mario Angarita, Darren Tan, Franz J. Meyer, David Fee, Aaron Wech
By
Volcano Hazards Program, Volcano Science Center

Cataloging tectonic tremor energy radiation in the Cascadia subduction zone

For the past ∼12 years the Pacific Northwest Seismic Network has been automatically detecting and locating tectonic tremor across the Cascadia subduction zone, resulting in a catalog of more than 500,000 tremor epicenters to date, which has served as a valuable resource for tremor and slip research. This manuscript presents an updated methodology for routine tremor detection in Cascadia and a new
Authors
Aaron Wech
By
Volcano Hazards Program, Volcano Science Center

Deep long-period earthquakes generated by second boiling beneath Mauna Kea volcano

Deep long-period earthquakes (DLPs) are an enigmatic type of volcanic seismicity that sometimes precedes eruptions but mostly occurs at quiescent volcanoes. These earthquakes are depleted in high-frequency content and typically occur near the base of the crust. We observed a near-periodic, long- lived sequence of more than one million DLPs in the past 19 years beneath the dormant postshield Mauna
Authors
Aaron Wech, Weston Thelen, Amanda Thomas
By
Volcano Hazards Program, Volcano Science Center

Infrasound generated by the 2016-2017 shallow submarine eruption of Bogoslof volcano, Alaska

The 2016–2017 shallow submarine eruption of Bogoslof volcano produced numerous infrasound signals over 9 months that were recorded on six Alaska Volcano Observatory (AVO) arrays at ranges of 59 to over 800 km from the volcano. The lack of geophysical monitoring near Bogoslof and the repeated production of volcanic clouds to flight levels made monitoring by remote infrasound critical during the eru
Authors
John J. Lyons, Alexandra M. Iezzi, David Fee, Hans Schwaiger, Aaron Wech, Matthew M. Haney
By
Volcano Hazards Program, Volcano Science Center

Upper plate heterogeneity along the Southern Hikurangi Margin, New Zealand

Controlled and natural source seismic data are used to build a 3-D P wave model for southern North Island, New Zealand, where the Pacific Plate subducts beneath the Australian Plate at a rate of ~41 mm/year. Our analysis reveals an abrupt along-strike transition in overthrusting plate structure within Cook Strait. Contrasts in properties (Vp, Vp/Vs, and Qs) likely reflects the degree of deformatio
Authors
Stuart Henrys, Donna Eberhart-Phillips, Dan Bassett, Rupert Sutherland, David Okaya, Martha Savage, Dominic Evanzia, Tim A. Stern, Hiroshi Sato, Kimihiro Mochizuki, Takaya Iwasaki, Eiji Kurashimo, Anya Seward, Aaron Wech
By
Volcano Hazards Program, Volcano Science Center

Constraints on eruption processes and event masses for the 2016–2017 eruption of Bogoslof volcano, Alaska, through evaluation of IASI satellite SO2 masses and complementary datasets

Bogoslof volcano, Alaska, experienced at least 70 explosive eruptions between 12 December 2016 and 31 August 2017. Due to its remote location and limited local monitoring network, this eruption was monitored and characterized primarily using remote geophysical and satellite techniques. SO2 emissions from Bogoslof were persistently detected by the Infrared Atmospheric Sounding Interferometer (IASI)
Authors
Taryn Lopez, Lieven Clarisse, Hans Schwaiger, Alexa R. Van Eaton, Matthew W. Loewen, David Fee, John J. Lyons, Kristi L. Wallace, Cheryl Searcy, Aaron Wech, Matthew M. Haney, David J. Schneider, Nathan Graham
By
Volcano Hazards Program, Volcano Science Center

Seismo-acoustic evidence for vent drying during shallow submarine eruptions at Bogoslof volcano, Alaska

Characterizing the state of the volcanic vent is key for interpreting observational datasets and accurately assessing volcanic hazards. This is particularly true for remote, complex eruptions such as the 2016–2017 Bogoslof volcano, Alaska eruption sequence. Bogoslof’s eruptions in this period were either shallow submarine or subaerial, or some combination of both. Our results demonstrate how low-f
Authors
David Fee, John J. Lyons, Matthew M. Haney, Aaron Wech, Christopher F. Waythomas, Angela K. Diefenbach, Taryn Lopez, Alexa R. Van Eaton, David J. Schneider
By
Volcano Hazards Program, Volcano Science Center

Overview, chronology, and impacts of the 2016–2017 eruption of Bogoslof volcano, Alaska

The 2016–2017 eruption of Bogoslof volcano, a back-arc shallow submarine volcano in Alaska’s Aleutian arc, began in December 2016 and included 70 explosive events and at least two episodes of subaerial dome building. Because the volcano had no local monitoring stations during the eruption, a combination of distant seismic stations, regional infrasound sensors, lightning detection, a variety of sat
Authors
Michelle L. Coombs, Kristi L. Wallace, Cheryl Cameron, John J. Lyons, Aaron Wech, Kim M. Angeli, Peter Cervelli
By
Volcano Hazards Program, Volcano Science Center
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