Publications
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Cogenetic late Pleistocene rhyolite and cumulate diorites from Augustine Volcano revealed by SIMS 238U-230Th dating of zircon, and implications for silicic magma generation by extraction from mush
Augustine Volcano, a frequently active andesitic island stratocone, erupted a late Pleistocene rhyolite pumice fall that is temporally linked through zircon geochronology to cumulate dioritic blocks brought to the surface in Augustine's 2006 eruption. Zircon from the rhyolite yield a 238U-230Th age of ∼25 ka for their unpolished rims, and their interiors yield a bimodal age populations at ∼26 ka a
Authors
Michelle L. Coombs, Jorge A. Vazquez
Metrics for comparing dynamic earthquake rupture simulations
Earthquakes are complex events that involve a myriad of interactions among multiple geologic features and processes. One of the tools that is available to assist with their study is computer simulation, particularly dynamic rupture simulation. A dynamic rupture simulation is a numerical model of the physical processes that occur during an earthquake. Starting with the fault geometry, friction cons
Authors
Michael Barall, Ruth A. Harris
Seismic instrumentation plan for the Hawaiian Volcano Observatory
The seismic network operated by the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) is the main source of authoritative data for reporting earthquakes in the State of Hawaii, including those that occur on the State’s six active volcanoes (Kīlauea, Mauna Loa, Hualālai, Mauna Kea, Haleakalā, Lō‘ihi). Of these volcanoes, Kīlauea and Mauna Loa are considered “very high threat” in a report
Authors
Weston A. Thelen
Investigation of the high-frequency attenuation parameter, κ (kappa), from aftershocks of the 2010 Mw 8.8 Maule, Chile earthquake
The Bío Bío region of Chile experienced a vigorous aftershock sequence following the 2010 February 27 Mw 8.8 Maule earthquake. The immediate aftershock sequence was captured by two temporary seismic deployments: the Quake Catcher Network Rapid Aftershock Mobilization Program (QCN RAMP) and the Incorporated Research Institutions for Seismology CHile Aftershock Mobilization Program (IRIS CHAMP). Her
Authors
Corrie Neighbors, E. J. Liao, Elizabeth S. Cochran, G. J. Funning, A. I. Chung, J. F. Lawrence, C. M. Christensen, M. Miller, A. Belmonte, H. H. Andrés Sepulveda
A new analysis of Mars "Special Regions": findings of the Second MEPAG Special Regions Science Analysis Group (SR-SAG2)
A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understan
Authors
John D. Rummel, David W. Beaty, Melissa A. Jones, Corien Bakermans, Nadine G. Barlow, Penelope J. Boston, Vincent F. Chevrier, Benton C. Clark, Jean-Pierre P. de Vera, Raina V. Gough, John E. Hallsworth, James W. Head, Victoria J. Hipkin, Thomas L. Kieft, Alfred S. McEwen, Michael T. Mellon, Jill A. Mikucki, Wayne L. Nicholson, Christopher R. Omelon, Ronald Peterson, Eric E. Roden, Barbara Sherwood Lollar, Kenneth L. Tanaka, Donna Viola, James J. Wray
World-Wide Standardized Seismograph Network: a data users guide
The purpose of this report, which is based on an unpublished draft prepared in the 1970s, is to provide seismologists with the information they may need to use the WWSSN data set as it becomes available in a more easily accessible and convenient format on the Internet. The report includes a description of the WWSSN network, station facilities, operations and instrumentation, a derivation of the in
Authors
Jon R. Peterson, Charles R. Hutt
Surveying the South Pole-Aitken basin magnetic anomaly for remnant impactor metallic iron
The Moon has areas of magnetized crust ("magnetic anomalies"), the origins of which are poorly constrained. A magnetic anomaly near the northern rim of South Pole-Aitken (SPA) basin was recently postulated to originate from remnant metallic iron emplaced by the SPA basin-forming impactor. Here, we remotely examine the regolith of this SPA magnetic anomaly with a combination of Clementine and Lunar
Authors
Joshua T.S. Cahill, Justin Hagerty, David M. Lawrence, Rachel L. Klima, David T. Blewett
Assessing inundation hazards to nuclear powerplant sites using geologically extended histories of riverine floods, tsunamis, and storm surges
Most nuclear powerplants in the United States are near rivers, large lakes, or oceans. As evident from the Fukushima Daiichi, Japan, disaster of 2011, these water bodies pose inundation threats. Geologic records can extend knowledge of rare hazards from flooding, storm surges, and tsunamis. This knowledge can aid in assessing the safety of critical structures such as dams and energy plants, for wh
Authors
Jim O'Connor, Brian F. Atwater, Timothy A. Cohn, Thomas M. Cronin, Mackenzie K. Keith, Christopher G. Smith, Robert R. Mason,
Coseismic landslides reveal near-surface rock strength in a high-relief tectonically active setting
We present quantitative estimates of near-surface rock strength relevant to landscape evolution and landslide hazard assessment for 15 geologic map units of the Longmen Shan, China. Strength estimates are derived from a novel method that inverts earthquake peak ground acceleration models and coseismic landslide inventories to obtain material proper- ties and landslide thickness. Aggregate rock str
Authors
Sean F. Gallen, Marin K. Clark, Jonathan W. Godt
The Late Cretaceous Middle Fork caldera, its resurgent intrusion, and enduring landscape stability in east-central Alaska
Dissected caldera structures expose thick intracaldera tuff and, uncommonly, cogenetic shallow plutons, while remnants of correlative outflow tuffs deposited on the pre-eruption ground surface record elements of ancient landscapes. The Middle Fork caldera encompasses a 10 km × 20 km area of rhyolite welded tuff and granite porphyry in east-central Alaska, ∼100 km west of the Yukon border. Intracal
Authors
Charles R. Bacon, Cynthia Dusel-Bacon, John N. Aleinikoff, John F. Slack
The 2011 Virginia M5.8 earthquake: Insights from seismic reflection imaging into the influence of older structures on eastern U.S. seismicity
The Mineral, Virginia (USA), earthquake of 23 August 2011 occurred at 6– 8 km depth within the allochthonous terranes of the Appalachian Piedmont Province, rupturing an ~N36°E striking reverse fault dipping ~50° southeast. This study used the Interstate Highway 64 seismic refl ection profi le acquired ~6 km southwest of the hypocenter to examine the structural setting of the earthquake. The profi
Authors
Thomas L. Pratt, J. Wright Horton, D.B. Spear, A.K. Gilmer, Daniel E. McNamara
The birth and death of transverse aeolian ridges on Mars
Transverse aeolian ridges (TARs) are small bright windblown deposits found throughout the Martian tropics that stand a few meters tall and are spaced a few tens of meters apart. The origin of these features remains mysterious more than 20 years after their discovery on Mars. This paper presents a new hypothesis, that some of the TARs could be indurated dust deposits emplaced millions of years ago
Authors
Paul E. Geissler