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.
Science and Products
Filter Total Items: 58
Source mechanisms of persistent shallow earthquakes during eruptive and non-eruptive periods between 1981 and 2011 at Mount St. Helens, Washington Source mechanisms of persistent shallow earthquakes during eruptive and non-eruptive periods between 1981 and 2011 at Mount St. Helens, Washington
Shallow seismicity between 0 and 3-km depth has persisted at Mount St. Helens, Washington (MSH) during both eruptive and non-eruptive periods for at least the past thirty years. In this study we investigate the source mechanisms of shallow volcano-tectonic (VT) earthquakes at MSH by calculating high-quality hypocenter locations and fault plane solutions (FPS) for all VT events recorded...
Authors
Heather L. Lehto, Diana C. Roman, Seth C. Moran
Faulting within the Mount St. Helens conduit and implications for volcanic earthquakes Faulting within the Mount St. Helens conduit and implications for volcanic earthquakes
The 2004–2008 eruption of Mount St. Helens produced seven dacite spines mantled by cataclastic fault rocks, comprising an outer fault core and an inner damage zone. These fault rocks provide remarkable insights into the mechanical processes that accompany extrusion of degassed magma, insights that are useful in forecasting dome-forming eruptions. The outermost part of the fault core...
Authors
John S. Pallister, Katharine V. Cashman, Jonathan T. Hagstrum, Nicholas M. Beeler, Seth C. Moran, Roger P. Denlinger
Volcanic earthquakes in Alaska's national parks Volcanic earthquakes in Alaska's national parks
Alaska’s national parks contain 11 historically active volcanoes (Figure 2), which produce thousands of small earthquakes every year. These earthquakes are voices of the magmatic and geothermal systems within the volcanoes. The Alaska Volcano Observatory (AVO), a joint program of the U.S. Geological Survey, the Geophysical Institute at the University of Alaska Fairbanks, and the Alaska...
Authors
Stephanie G. Prejean, Seth C. Moran, John A. Power, Michael J. West
Failed magmatic eruptions: Late-stage cessation of magma ascent Failed magmatic eruptions: Late-stage cessation of magma ascent
When a volcano becomes restless, a primary question is whether the unrest will lead to an eruption. Here we recognize four possible outcomes of a magmatic intrusion: "deep intrusion", "shallow intrusion", "sluggish/viscous magmatic eruption", and "rapid, often explosive magmatic eruption". We define "failed eruptions" as instances in which magma reaches but does not pass the "shallow...
Authors
S.C. Moran, C. Newhall, D.C. Roman
Deep long-period earthquakes beneath Washington and Oregon volcanoes Deep long-period earthquakes beneath Washington and Oregon volcanoes
Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic...
Authors
M.L. Nichols, S. D. Malone, Seth C. Moran, Weston A. Thelen, J.E. Vidale
Temporal changes in stress preceding the 2004-2008 eruption of Mount St. Helens, Washington 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...
Authors
H.L. Lehto, D.C. Roman, S.C. Moran
Science and Products
Filter Total Items: 58
Source mechanisms of persistent shallow earthquakes during eruptive and non-eruptive periods between 1981 and 2011 at Mount St. Helens, Washington Source mechanisms of persistent shallow earthquakes during eruptive and non-eruptive periods between 1981 and 2011 at Mount St. Helens, Washington
Shallow seismicity between 0 and 3-km depth has persisted at Mount St. Helens, Washington (MSH) during both eruptive and non-eruptive periods for at least the past thirty years. In this study we investigate the source mechanisms of shallow volcano-tectonic (VT) earthquakes at MSH by calculating high-quality hypocenter locations and fault plane solutions (FPS) for all VT events recorded...
Authors
Heather L. Lehto, Diana C. Roman, Seth C. Moran
Faulting within the Mount St. Helens conduit and implications for volcanic earthquakes Faulting within the Mount St. Helens conduit and implications for volcanic earthquakes
The 2004–2008 eruption of Mount St. Helens produced seven dacite spines mantled by cataclastic fault rocks, comprising an outer fault core and an inner damage zone. These fault rocks provide remarkable insights into the mechanical processes that accompany extrusion of degassed magma, insights that are useful in forecasting dome-forming eruptions. The outermost part of the fault core...
Authors
John S. Pallister, Katharine V. Cashman, Jonathan T. Hagstrum, Nicholas M. Beeler, Seth C. Moran, Roger P. Denlinger
Volcanic earthquakes in Alaska's national parks Volcanic earthquakes in Alaska's national parks
Alaska’s national parks contain 11 historically active volcanoes (Figure 2), which produce thousands of small earthquakes every year. These earthquakes are voices of the magmatic and geothermal systems within the volcanoes. The Alaska Volcano Observatory (AVO), a joint program of the U.S. Geological Survey, the Geophysical Institute at the University of Alaska Fairbanks, and the Alaska...
Authors
Stephanie G. Prejean, Seth C. Moran, John A. Power, Michael J. West
Failed magmatic eruptions: Late-stage cessation of magma ascent Failed magmatic eruptions: Late-stage cessation of magma ascent
When a volcano becomes restless, a primary question is whether the unrest will lead to an eruption. Here we recognize four possible outcomes of a magmatic intrusion: "deep intrusion", "shallow intrusion", "sluggish/viscous magmatic eruption", and "rapid, often explosive magmatic eruption". We define "failed eruptions" as instances in which magma reaches but does not pass the "shallow...
Authors
S.C. Moran, C. Newhall, D.C. Roman
Deep long-period earthquakes beneath Washington and Oregon volcanoes Deep long-period earthquakes beneath Washington and Oregon volcanoes
Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic...
Authors
M.L. Nichols, S. D. Malone, Seth C. Moran, Weston A. Thelen, J.E. Vidale
Temporal changes in stress preceding the 2004-2008 eruption of Mount St. Helens, Washington 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...
Authors
H.L. Lehto, D.C. Roman, S.C. Moran