Publications
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A geologic field guide to S P Mountain and its lava flow, San Francisco Volcanic Field, Arizona
IntroductionWe created this guide to introduce the user to the San Francisco Volcanic Field as a terrestrial analog site for planetary volcanic processes. For decades, the San Francisco Volcanic Field has been used to teach scientists to recognize the products of common types of volcanic eruptions and associated volcanic features. The volcanic processes and products observed in this volcanic field
Authors
Amber L. Gullikson, M. Elise Rumpf, Lauren A. Edgar, Laszlo P. Keszthelyi, James A. Skinner, Lisa Thompson
The trajectory of soil development and its relationship to soil carbon dynamics
It has been postulated that the amount of soil organic carbon (SOC) associated with soil minerals exhibits a threshold relationship in response to effective soil moisture (estimated as precipitation less evapotranspiration). To better characterize the role of moisture in influencing mechanisms of SOC storage during pedogenesis, we compare soils from two different chronosequence sites: the Santa Cr
Authors
Corey Lawrence, Marjorie S. Schulz, Caroline Masiello, Oliver A. Chadwick, Jennifer W. Harden
Channel-amphitheatre landforms resulting from liquefaction flowslides during rapid drawdown of glacial Lake Fraser, British Columbia, Canada
Unusual channel-amphitheatre landforms are present in Late Pleistocene–early Holocene, subaqueous fan and delta deposits in the glacial Lake Fraser basin, central British Columbia. The lake formed during the decay of the last Cordilleran Ice Sheet and drained ~11,500 years ago during a large outburst flood. The fronts of a delta and two subaqueous fans consisting of silt to fine sand are marked by
Authors
Brendan G.N. Miller, Richard M. Iverson, John J. Clague, Marten Geertsema, Nicholas J. Roberts
Trachyandesite of Kennedy Table, its vent complex, and post−9.3 Ma uplift of the central Sierra Nevada
Tectonic interpretation of the central Sierra Nevada—whether the crest of the Sierra Nevada (California, USA) was uplifted in the late Cenozoic or whether the range has undergone continuous down-wearing since the Late Cretaceous—is controversial, since there is no obvious tectonic explanation for renewed uplift. The strongest direct evidence for late Cenozoic uplift of the central Sierra Nevada co
Authors
Edward Hildreth, Judith Fierstein, Fred M. Phillips, Andrew T. Calvert
Why study geysers?
Scientific research for more than two centuries has improved our understanding of Earth’s geysers. This knowledge provides insights into volcanic processes, the origin and environmental limits of life on Earth and potentially Mars, and on geysers on icy outer solar system satellites. Continued scientific research will help us understand and protect these natural wonders that attract millions of to
Authors
Shaul Hurwitz, Michael Manga, Kathleen Campbell, Carolina Munoz-Saez, Eva Eibl
Repeating caldera collapse events constrain fault friction at the kilometer scale
Fault friction is central to understanding earthquakes, yet laboratory rock mechanics experiments are restricted to, at most, meter scale. Questions thus remain as to the applicability of measured frictional properties to faulting in situ. In particular, the slip-weakening distance dcdc strongly influences precursory slip during earthquake nucleation, but scales with fault roughness and is challen
Authors
Paul Segall, Kyle R. Anderson
The products of primary magma fragmentation finally revealed by pumice agglomerates
Following rapid decompression in the conduit of a volcano, magma breaks into ash- to block-sized fragments, powering explosive sub-Plinian and Plinian eruptions that may generate destructive pyroclastic falls and flows. It is thus crucial to assess how magma breaks up into fragments. This task is difficult, however, because of the subterranean nature of the entire process and because the original
Authors
Thomas Giachetti, Kathy Trafton, Joshua Wiejaczka, James E. Gardner, James M. Watkins, Tom Shea, Heather M. Wright
Long-term year-round observations of magmatic CO2 emissions on Mammoth Mountain, California, USA
Diffuse emission of magmatic CO2 is one of the main indicators of volcanic unrest at Mammoth Mountain, but the presence of deep seasonal snowpack at the site has hindered year-round CO2 flux observations. A permanent eddy covariance station was established at the largest area of diffuse CO2 degassing on Mammoth Mountain (Horseshoe Lake tree kill) that measured CO2 fluxes (Fc) and meteorological pa
Authors
Jennifer L. Lewicki
Seismic monitoring during crises at the NEIC in support of the ANSS
Over the past two decades, the U.S. Geological Survey (USGS) National Earthquake Information Center (NEIC) has overcome many operational challenges. These range from minor disruptions, such as power outages, to significant operational changes, including system reconfiguration to handle unique earthquake sequences and the need to handle distributed work during a pandemic. Our ability to overcome cr
Authors
Paul S. Earle, Harley M. Benz, William L. Yeck, Gavin P. Hayes, Michelle Guy, John Patton, David Kragness, David B. Mason, Brian Shiro, Emily Wolin, John Bellini, Jana Pursley, Robert Lorne Sanders
Preliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska
We simulated the concurrent rapid motion of landslides on an unstable slope at Barry Arm, Alaska. Movement of landslides into the adjacent fjord displaced fjord water and generated a tsunami, which propagated out of Barry Arm. Rather than assuming an initial sea surface height, velocity, and location for the tsunami, we generated the tsunami directly using a model capable of simulating the dynamic
Authors
Katherine R. Barnhart, Ryan P. Jones, David L. George, Jeffrey A. Coe, Dennis M. Staley
The petrologic and degassing behavior of sulfur and other magmatic volatiles from the 2018 eruption of Kīlauea, Hawaiʻi: Melt concentrations, magma storage depths, and magma recycling
Kīlauea Volcano’s 2018 lower East Rift Zone (LERZ) eruption produced exceptionally high lava effusion rates and record-setting SO2 emissions. The eruption involved a diverse range of magmas, including primitive basalts sourced from Kīlauea’s summit reservoirs. We analyzed LERZ matrix glasses, melt inclusions, and host minerals to identify melt volatile contents and magma storage depths. The LERZ g
Authors
Allan Lerner, Paul J. Wallace, Thomas Shea, Adrien Mourey, Peter J. Kelly, Patricia Nadeau, Tamar Elias, Christoph Kern, Laura E. Clor, Cheryl Gansecki, R. Lopaka Lee, Lowell Moore, Cynthia A. Werner
Time-evolving surface and subsurface signatures of Quaternary volcanism in the Cascades Arc: Reply
No abstract available.
Authors
Daniel O'Hara, Leif Karlstrom, David W. Ramsey