Seth Moran, Ph.D.
My professional career has largely been devoted to the study of active volcanoes and volcano seismology, with a hiatus in 2015-2020 to serve as the Scientist-in-Charge of the Cascades Volcano Observatory. I am interested in all things volcanoes and seismology, as well as hazards in general. I'm also interested in science communication and in seeking ways to build more inclusive workplace environments.
Science and Products
Filter Total Items: 53
Temporal changes in stress preceding the 2004-2008 eruption of Mount St. Helens, Washington
The 2004-2008 eruption of Mount St. Helens (MSH), Washington, was preceded by a swarm of shallow volcano-tectonic earthquakes (VTs) that began on September 23, 2004. We calculated locations and fault-plane solutions (FPS) for shallow VTs recorded during a background period (January 1999 to July 2004) and during the early vent-clearing phase (September 23 to 29, 2004) of the 2004-2008 eruption. FPS
Authors
H.L. Lehto, D.C. Roman, S.C. Moran
Volcano monitoring
Volcanoes are not randomly distributed over the Earth's surface. Most are concentrated on the edges of continents, along island chains, or beneath the sea where they form long mountain ranges. More than half of the world's active volcanoes above sea level encircle the Pacific Ocean (see Fig. 1). The concept of plate tectonics explains the locations of volcanoes and their relationship to other larg
Authors
James G. Smith, Jonathan Dehn, Richard P. Hoblitt, Richard G. Lahusen, Jacob B. Lowenstern, Seth C. Moran, Lindsay McClelland, Kenneth A. McGee, Manuel Nathenson, Paul G. Okubo, John S. Pallister, Michael P. Poland, John A. Power, David J. Schneider, Thomas W. Sisson
VP Structure of Mount St. Helens, Washington, USA, imaged with local earthquake tomography
We present a new P-wave velocity model for Mount St. Helens using local earthquake data recorded by the Pacific Northwest Seismograph Stations and Cascades Volcano Observatory since the 18 May 1980 eruption. These data were augmented with records from a dense array of 19 temporary stations deployed during the second half of 2005. Because the distribution of earthquakes in the study area is concent
Authors
G.P. Waite, S.C. Moran
Instrumentation recommendations for volcano monitoring at U.S. volcanoes under the national volcano early warning system
As magma moves toward the surface, it interacts with anything in its path: hydrothermal systems, cooling magma bodies from previous eruptions, and (or) the surrounding “country rock.” Magma also undergoes significant changes in its physical properties as pressure and temperature conditions change along its path. These interactions and changes lead to a range of geophysical and geochemical phenomen
Authors
Seth C. Moran, Jeff T. Freymueller, Richard G. LaHusen, Kenneth A. McGee, Michael P. Poland, John A. Power, David A. Schmidt, David J. Schneider, George Stephens, Cynthia A. Werner, Randall A. White
Seismic-monitoring changes and the remote deployment of seismic stations (seismic spider) at Mount St. Helens, 2004-2005
The instruments in place at the start of volcanic unrest at
Mount St. Helens in 2004 were inadequate to record the large
earthquakes and monitor the explosions that occurred as the
eruption developed. To remedy this, new instruments were
deployed and the short-period seismic network was modified.
A new method of establishing near-field seismic monitoring
was developed, using remote deploymen
Authors
Patrick J. McChesney, Marvin R. Couchman, Seth C. Moran, Andrew B. Lockhart, Kelly J. Swinford, Richard G. LaHusen
Seismicity and infrasound associated with explosions at Mount St. Helens, 2004-2005
Six explosions occurred during 2004-5 in association
with renewed eruptive activity at Mount St. Helens, Washington. Of four explosions in October 2004, none had precursory
seismicity and two had explosion-related seismic tremor that
marked the end of the explosion. However, seismicity levels
dropped following each of the October explosions, providing
the primary instrumental means for explos
Authors
Seth C. Moran, Patrick J. McChesney, Andrew B. Lockhart
Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005
From October 2004 to May 2005, the Center for Earthquake Research and Information of the University of Memphis
operated two to six broadband seismometers within 5 to 20
km of Mount St. Helens to help monitor recent seismic and
volcanic activity. Approximately 57,000 earthquakes identified during the 7-month deployment had a normal magnitude
distribution with a mean magnitude of 1.78 and a stan
Authors
Stephen P. Horton, Robert D. Norris, Seth C. Moran
Near-real-time information products for Mount St. Helens -- tracking the ongoing eruption
The rapid onset of energetic seismicity on September
23, 2004, at Mount St. Helens caused seismologists at the
Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques
that summarized and displayed seismic parameters for use by
scientists and the general public. Such techniques included
webicorders (Web-based helicorder-like displays), g
Authors
Anthony I. Qamar, Stephen Malone, Seth C. Moran, William P. Steele, Weston A. Thelen
The 8 October 2006 Md 4.5 Cowlitz chimneys earthquake in Mount Rainier National Park
An Md 4.5 earthquake located ∼12 km east of Mount Rainier occurred on 8 October 2006 at 02:48 UTC (figure 1). Although not large enough to be damaging or of major tectonic significance, a summary description of the earthquake is warranted because of its proximity to Mount Rainier, and because earthquakes of Md ≥ 4.5 are relatively rare in this region. Previous events of Md ≥ 4.5 have occurred appr
Authors
J. Renate Hartog, Joan S. Gomberg, Seth C. Moran, Amy K. Wright, Karen L. Meagher
Seismic and acoustic recordings of an unusually large rockfall at Mount St. Helens, Washington
On 29 May 2006 a large rockfall off the Mount St. Helens lava dome produced an atmospheric plume that was reported by airplane pilots to have risen to 6,000 m above sea level and interpreted to be a result of an explosive event. However, subsequent field reconnaissance found no evidence of a ballistic field, indicating that there was no explosive component. The rockfall produced complex seismic an
Authors
Seth C. Moran, R.S. Matoza, M.A. Garces, M.A.H. Hedlin, D. Bowers, William E. Scott, David R. Sherrod, James W. Vallance
Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska
The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6 km below sea level and encompasses all of the Katmai volcanoes; Martin, Mageik, Triden
Authors
A.D. Jolly, S.C. Moran, S.R. McNutt, D.B. Stone
Dynamics of seismogenic volcanic extrusion at Mount St Helens in 2004-05
The 2004-05 eruption of Mount St Helens exhibited sustained, near-equilibrium behaviour characterized by relatively steady extrusion of a solid dacite plug and nearly periodic shallow earthquakes. Here we present a diverse data set to support our hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upwards by ascending, soli
Authors
R. M. Iverson, D. Dzurisin, C. A. Gardner, T.M. Gerlach, R.G. LaHusen, M. Lisowski, J. J. Major, S. D. Malone, J.A. Messerich, S.C. Moran, J.S. Pallister, A.I. Qamar, S. P. Schilling, J.W. Vallance
Science and Products
Filter Total Items: 53
Temporal changes in stress preceding the 2004-2008 eruption of Mount St. Helens, Washington
The 2004-2008 eruption of Mount St. Helens (MSH), Washington, was preceded by a swarm of shallow volcano-tectonic earthquakes (VTs) that began on September 23, 2004. We calculated locations and fault-plane solutions (FPS) for shallow VTs recorded during a background period (January 1999 to July 2004) and during the early vent-clearing phase (September 23 to 29, 2004) of the 2004-2008 eruption. FPS
Authors
H.L. Lehto, D.C. Roman, S.C. Moran
Volcano monitoring
Volcanoes are not randomly distributed over the Earth's surface. Most are concentrated on the edges of continents, along island chains, or beneath the sea where they form long mountain ranges. More than half of the world's active volcanoes above sea level encircle the Pacific Ocean (see Fig. 1). The concept of plate tectonics explains the locations of volcanoes and their relationship to other larg
Authors
James G. Smith, Jonathan Dehn, Richard P. Hoblitt, Richard G. Lahusen, Jacob B. Lowenstern, Seth C. Moran, Lindsay McClelland, Kenneth A. McGee, Manuel Nathenson, Paul G. Okubo, John S. Pallister, Michael P. Poland, John A. Power, David J. Schneider, Thomas W. Sisson
VP Structure of Mount St. Helens, Washington, USA, imaged with local earthquake tomography
We present a new P-wave velocity model for Mount St. Helens using local earthquake data recorded by the Pacific Northwest Seismograph Stations and Cascades Volcano Observatory since the 18 May 1980 eruption. These data were augmented with records from a dense array of 19 temporary stations deployed during the second half of 2005. Because the distribution of earthquakes in the study area is concent
Authors
G.P. Waite, S.C. Moran
Instrumentation recommendations for volcano monitoring at U.S. volcanoes under the national volcano early warning system
As magma moves toward the surface, it interacts with anything in its path: hydrothermal systems, cooling magma bodies from previous eruptions, and (or) the surrounding “country rock.” Magma also undergoes significant changes in its physical properties as pressure and temperature conditions change along its path. These interactions and changes lead to a range of geophysical and geochemical phenomen
Authors
Seth C. Moran, Jeff T. Freymueller, Richard G. LaHusen, Kenneth A. McGee, Michael P. Poland, John A. Power, David A. Schmidt, David J. Schneider, George Stephens, Cynthia A. Werner, Randall A. White
Seismic-monitoring changes and the remote deployment of seismic stations (seismic spider) at Mount St. Helens, 2004-2005
The instruments in place at the start of volcanic unrest at
Mount St. Helens in 2004 were inadequate to record the large
earthquakes and monitor the explosions that occurred as the
eruption developed. To remedy this, new instruments were
deployed and the short-period seismic network was modified.
A new method of establishing near-field seismic monitoring
was developed, using remote deploymen
Authors
Patrick J. McChesney, Marvin R. Couchman, Seth C. Moran, Andrew B. Lockhart, Kelly J. Swinford, Richard G. LaHusen
Seismicity and infrasound associated with explosions at Mount St. Helens, 2004-2005
Six explosions occurred during 2004-5 in association
with renewed eruptive activity at Mount St. Helens, Washington. Of four explosions in October 2004, none had precursory
seismicity and two had explosion-related seismic tremor that
marked the end of the explosion. However, seismicity levels
dropped following each of the October explosions, providing
the primary instrumental means for explos
Authors
Seth C. Moran, Patrick J. McChesney, Andrew B. Lockhart
Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005
From October 2004 to May 2005, the Center for Earthquake Research and Information of the University of Memphis
operated two to six broadband seismometers within 5 to 20
km of Mount St. Helens to help monitor recent seismic and
volcanic activity. Approximately 57,000 earthquakes identified during the 7-month deployment had a normal magnitude
distribution with a mean magnitude of 1.78 and a stan
Authors
Stephen P. Horton, Robert D. Norris, Seth C. Moran
Near-real-time information products for Mount St. Helens -- tracking the ongoing eruption
The rapid onset of energetic seismicity on September
23, 2004, at Mount St. Helens caused seismologists at the
Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques
that summarized and displayed seismic parameters for use by
scientists and the general public. Such techniques included
webicorders (Web-based helicorder-like displays), g
Authors
Anthony I. Qamar, Stephen Malone, Seth C. Moran, William P. Steele, Weston A. Thelen
The 8 October 2006 Md 4.5 Cowlitz chimneys earthquake in Mount Rainier National Park
An Md 4.5 earthquake located ∼12 km east of Mount Rainier occurred on 8 October 2006 at 02:48 UTC (figure 1). Although not large enough to be damaging or of major tectonic significance, a summary description of the earthquake is warranted because of its proximity to Mount Rainier, and because earthquakes of Md ≥ 4.5 are relatively rare in this region. Previous events of Md ≥ 4.5 have occurred appr
Authors
J. Renate Hartog, Joan S. Gomberg, Seth C. Moran, Amy K. Wright, Karen L. Meagher
Seismic and acoustic recordings of an unusually large rockfall at Mount St. Helens, Washington
On 29 May 2006 a large rockfall off the Mount St. Helens lava dome produced an atmospheric plume that was reported by airplane pilots to have risen to 6,000 m above sea level and interpreted to be a result of an explosive event. However, subsequent field reconnaissance found no evidence of a ballistic field, indicating that there was no explosive component. The rockfall produced complex seismic an
Authors
Seth C. Moran, R.S. Matoza, M.A. Garces, M.A.H. Hedlin, D. Bowers, William E. Scott, David R. Sherrod, James W. Vallance
Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska
The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6 km below sea level and encompasses all of the Katmai volcanoes; Martin, Mageik, Triden
Authors
A.D. Jolly, S.C. Moran, S.R. McNutt, D.B. Stone
Dynamics of seismogenic volcanic extrusion at Mount St Helens in 2004-05
The 2004-05 eruption of Mount St Helens exhibited sustained, near-equilibrium behaviour characterized by relatively steady extrusion of a solid dacite plug and nearly periodic shallow earthquakes. Here we present a diverse data set to support our hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upwards by ascending, soli
Authors
R. M. Iverson, D. Dzurisin, C. A. Gardner, T.M. Gerlach, R.G. LaHusen, M. Lisowski, J. J. Major, S. D. Malone, J.A. Messerich, S.C. Moran, J.S. Pallister, A.I. Qamar, S. P. Schilling, J.W. Vallance