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Post-1978 tumescence at Long Valley Caldera, California: A geophysical perspective
Long Valley Caldera has been restless since at least 1978. Prominent symptoms of this unrest include earthquake swarms and tumescence (inflation) centered on the resurgent dome. Over the years, interpretations of physical processes underlying this unrest have varied considerably. Results from a collection of geophysical studies infer the presence and/or active intrusion of magma in the crust. Geol
Authors
David P. Hill, Emily Montgomery-Brown, David R. Shelly, Ashton F. Flinders, Stephanie Prejean
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
Seismic evidence for significant melt beneath the Long Valley Caldera, California, USA
A little more than 760 ka ago, a supervolcano on the eastern edge of California (United States) underwent one of North America's largest Quaternary explosive eruptions. Over this ~6-day-long eruption, pyroclastic flows blanketed the surrounding ~50 km with more than 1400 km3 of the now-iconic Bishop Tuff, with ashfall reaching as far east as Nebraska. Collapse of the volcano's magma reservoir crea
Authors
Ashton F. Flinders, David R. Shelly, Phillip B. Dawson, David P. Hill, Barbara Tripoli, Yang Shen
Volcanic unrest and hazard communication in Long Valley Volcanic Region, California
The onset of volcanic unrest in Long Valley Caldera, California, in 1980 and the subsequent fluctuations in unrest levels through May 2016 illustrate: (1) the evolving relations between scientists monitoring the unrest and studying the underlying tectonic/magmatic processes and their implications for geologic hazards, and (2) the challenges in communicating the significance of the hazards to the p
Authors
David P. Hill, Margaret T. Mangan, Stephen R. McNutt
Long Valley Caldera-Mammoth Mountain unrest: The knowns and the unknowns
This perspective is based largely on my study of the Long Valley Caldera (California, USA) over the past 40 years. Here, I’ll examine the “knowns” and the “known unknowns” of the complex tectonic–magmatic system of the Long Valley Caldera volcanic complex. I will also offer a few brief thoughts on the “unknown unknowns” of this system.
Authors
David P. Hill
Fluid-faulting interactions: Fracture-mesh and fault-valve behavior in the February 2014 Mammoth Mountain, California, earthquake swarm
Faulting and fluid transport in the subsurface are highly coupled processes, which may manifest seismically as earthquake swarms. A swarm in February 2014 beneath densely monitored Mammoth Mountain, California, provides an opportunity to witness these interactions in high resolution. Toward this goal, we employ massive waveform-correlation-based event detection and relative relocation, which quadr
Authors
David R. Shelly, Taka’aki Taira, Stephanie Prejean, David P. Hill, Douglas S. Dreger
S-wave triggering of tremor beneath the Parkfield, California, section of the San Andreas fault by the 2011 Tohoku, Japan earthquake: observations and theory
The dynamic stresses that are associated with the energetic seismic waves generated by the Mw 9.0 Tohoku earthquake off the northeast coast of Japan triggered bursts of tectonic tremor beneath the Parkfield section of the San Andreas fault (SAF) at an epicentral distance of ∼8200 km. The onset of tremor begins midway through the ∼100‐s‐period S‐wave arrival, with a minor burst coinciding with the
Authors
David P. Hill, Zhigang Peng, David R. Shelly, Chastity Aiken
Dynamic stresses, Coulomb failure, and remote triggering
Dynamic stresses associated with crustal surface waves with 15-30-sec periods and peak amplitudes < 1 MPa are capable of triggering seismicity at sites remote from the generating mainshock under appropriate conditions. Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid-onset triggered seismicity that develop during the surface-wave peak dyn
Authors
David P. Hill
Interdisciplinary discussion of volcanic processes beneath the Long Valley Caldera-Mono Craters Area
Volcanism in the Long Valley Caldera-Mono Craters (LVCMC) volcanic field in eastern California over the past 4 Ma is dominated by the 0.76 Ma caldera-forming eruption of 600 km3 of rhyolite to form the Bishop Tuff. Over the last 150 k.y., volcanism has concentrated along the Mono-Inyo chain, which extends 45 km north from Mammoth Mountain to Mono Lake (Figure 1, below). Recent eruptions along this
Authors
David P. Hill, Paul Segall
EarthScoping the inner workings of magmatic systems
In the shadow of one of the world's great volcanic systems, an intensive 3-day workshop was undertaken to work toward developing a scientific plan for the magmatic systems component of the U.S. National Science Foundation's (NSF) EarthScope Initiative. This NSF-sponsored workshop was designed to provide direction to the EarthScope planning committee and the NSF in developing scientific, technical,
Authors
Michael W Hamburger, Stephen McNutt, Daniel Dzurisin, Jonathan Fink, David P. Hill, Charles Meertens, Chris Newhall, Susan Owen, John A. Power
Earthquake-volcano interactions
No abstract available.
Authors
David P. Hill, Fred Pollitz, Christopher Newhall
Very-long-period volcanic earthquakes beneath Mammoth Mountain, California
Detection of three very‐long‐period (VLP) volcanic earthquakes beneath Mammoth Mountain emphasizes that magmatic processes continue to be active beneath this young, eastern California volcano. These VLP earthquakes, which occurred in October 1996 and July and August 2000, appear as bell‐shaped pulses with durations of one to two minutes on a nearby borehole dilatometer and on the displacement seis
Authors
David P. Hill, P. Dawson, M. J. S. Johnston, A. M. Pitt, G. Biasi, K. Smith
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Filter Total Items: 14
Post-1978 tumescence at Long Valley Caldera, California: A geophysical perspective
Long Valley Caldera has been restless since at least 1978. Prominent symptoms of this unrest include earthquake swarms and tumescence (inflation) centered on the resurgent dome. Over the years, interpretations of physical processes underlying this unrest have varied considerably. Results from a collection of geophysical studies infer the presence and/or active intrusion of magma in the crust. GeolAuthorsDavid P. Hill, Emily Montgomery-Brown, David R. Shelly, Ashton F. Flinders, Stephanie PrejeanDeep 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 detectionAuthorsAlicia J. Hotovec-Ellis, David R. Shelly, David P. Hill, Andrew M. Pitt, Phillip B. Dawson, Bernard A. ChouetSeismic evidence for significant melt beneath the Long Valley Caldera, California, USA
A little more than 760 ka ago, a supervolcano on the eastern edge of California (United States) underwent one of North America's largest Quaternary explosive eruptions. Over this ~6-day-long eruption, pyroclastic flows blanketed the surrounding ~50 km with more than 1400 km3 of the now-iconic Bishop Tuff, with ashfall reaching as far east as Nebraska. Collapse of the volcano's magma reservoir creaAuthorsAshton F. Flinders, David R. Shelly, Phillip B. Dawson, David P. Hill, Barbara Tripoli, Yang ShenVolcanic unrest and hazard communication in Long Valley Volcanic Region, California
The onset of volcanic unrest in Long Valley Caldera, California, in 1980 and the subsequent fluctuations in unrest levels through May 2016 illustrate: (1) the evolving relations between scientists monitoring the unrest and studying the underlying tectonic/magmatic processes and their implications for geologic hazards, and (2) the challenges in communicating the significance of the hazards to the pAuthorsDavid P. Hill, Margaret T. Mangan, Stephen R. McNuttLong Valley Caldera-Mammoth Mountain unrest: The knowns and the unknowns
This perspective is based largely on my study of the Long Valley Caldera (California, USA) over the past 40 years. Here, I’ll examine the “knowns” and the “known unknowns” of the complex tectonic–magmatic system of the Long Valley Caldera volcanic complex. I will also offer a few brief thoughts on the “unknown unknowns” of this system.AuthorsDavid P. HillFluid-faulting interactions: Fracture-mesh and fault-valve behavior in the February 2014 Mammoth Mountain, California, earthquake swarm
Faulting and fluid transport in the subsurface are highly coupled processes, which may manifest seismically as earthquake swarms. A swarm in February 2014 beneath densely monitored Mammoth Mountain, California, provides an opportunity to witness these interactions in high resolution. Toward this goal, we employ massive waveform-correlation-based event detection and relative relocation, which quadrAuthorsDavid R. Shelly, Taka’aki Taira, Stephanie Prejean, David P. Hill, Douglas S. DregerS-wave triggering of tremor beneath the Parkfield, California, section of the San Andreas fault by the 2011 Tohoku, Japan earthquake: observations and theory
The dynamic stresses that are associated with the energetic seismic waves generated by the Mw 9.0 Tohoku earthquake off the northeast coast of Japan triggered bursts of tectonic tremor beneath the Parkfield section of the San Andreas fault (SAF) at an epicentral distance of ∼8200 km. The onset of tremor begins midway through the ∼100‐s‐period S‐wave arrival, with a minor burst coinciding with theAuthorsDavid P. Hill, Zhigang Peng, David R. Shelly, Chastity AikenDynamic stresses, Coulomb failure, and remote triggering
Dynamic stresses associated with crustal surface waves with 15-30-sec periods and peak amplitudes < 1 MPa are capable of triggering seismicity at sites remote from the generating mainshock under appropriate conditions. Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid-onset triggered seismicity that develop during the surface-wave peak dynAuthorsDavid P. HillInterdisciplinary discussion of volcanic processes beneath the Long Valley Caldera-Mono Craters Area
Volcanism in the Long Valley Caldera-Mono Craters (LVCMC) volcanic field in eastern California over the past 4 Ma is dominated by the 0.76 Ma caldera-forming eruption of 600 km3 of rhyolite to form the Bishop Tuff. Over the last 150 k.y., volcanism has concentrated along the Mono-Inyo chain, which extends 45 km north from Mammoth Mountain to Mono Lake (Figure 1, below). Recent eruptions along thisAuthorsDavid P. Hill, Paul SegallEarthScoping the inner workings of magmatic systems
In the shadow of one of the world's great volcanic systems, an intensive 3-day workshop was undertaken to work toward developing a scientific plan for the magmatic systems component of the U.S. National Science Foundation's (NSF) EarthScope Initiative. This NSF-sponsored workshop was designed to provide direction to the EarthScope planning committee and the NSF in developing scientific, technical,AuthorsMichael W Hamburger, Stephen McNutt, Daniel Dzurisin, Jonathan Fink, David P. Hill, Charles Meertens, Chris Newhall, Susan Owen, John A. PowerEarthquake-volcano interactions
No abstract available.AuthorsDavid P. Hill, Fred Pollitz, Christopher NewhallVery-long-period volcanic earthquakes beneath Mammoth Mountain, California
Detection of three very‐long‐period (VLP) volcanic earthquakes beneath Mammoth Mountain emphasizes that magmatic processes continue to be active beneath this young, eastern California volcano. These VLP earthquakes, which occurred in October 1996 and July and August 2000, appear as bell‐shaped pulses with durations of one to two minutes on a nearby borehole dilatometer and on the displacement seisAuthorsDavid P. Hill, P. Dawson, M. J. S. Johnston, A. M. Pitt, G. Biasi, K. Smith
*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