Publications
Filter Total Items: 7239
A 50-year Sr/Ca time series from an enclosed, shallow-water Guam coral: In situ monitoring and extraction of a temperature trend, annual cycle, and ENSO and PDO signals
Located on the northern edge of the West Pacific Warm Pool and having a developed economy and modern infrastructure, Guam is well positioned and equipped for obtaining natural records of the west Pacific maritime paleoclimate. This study was a proof of concept to explore whether useful climate proxy records might be obtained from coral at readily accessible, even if geochemically nonoptimal, coast
Authors
Tomoko Bell, Mark Lander, John Jenson, Richard Randall, Judson W. Partin, Nancy G. Prouty
On the intensity of the magnetic superstorm of September 1909
Analysis is made of solar observations and ground‐based magnetometer data recording space weather before and during the magnetic superstorm of 25 September 1909. From these data, it is inferred that the storm was initiated by an interplanetary coronal‐mass ejection having a mean Sun‐to‐Earth velocity of ~1,679 km/s. The commencement pressure on the magnetopause was ~32.4 nPa, sufficient to compres
Authors
Jeffrey J. Love, Hisashi Hayakawa, Edward W. Cliver
Updated California aftershock parameters
Reasenberg and Jones (1989) introduced a statistical model for aftershock rate following a mainshock along with estimates of “generic” California parameter values based on past aftershock sequences. The Reasenberg and Jones (1989) model has been used for decades to issue aftershock forecasts following M≥5 mainshocks in California. Here, we update the “generic” parameters for California through a f
Authors
Jeanne L. Hardebeck, Andrea L. Llenos, Andrew J. Michael, Morgan T. Page, Nicholas van der Elst
The Albuquerque Seismological Lab WWSSN film chip preservation project
From 1961 to 1996, the Albuquerque Seismological Laboratory (ASL) installed and operated the World‐Wide Standardized Seismograph Network (WWSSN). Each station within the network consisted of three Benioff short‐period sensors and three Sprengnether Press‐Ewing long‐period sensors along with recording, timing, and calibration equipment. Approximately 3.7 million single‐day record film chips were cr
Authors
Alexis Casondra Bianca Alejandro, Charles R. Hutt, Adam T. Ringler, Sabrina Veronica Moore, Robert E. Anthony, David C. Wilson
Global Earthquake Model (GEM) Risk Map
The Global Earthquake Risk Map (v2018.1) comprises four global maps. The main map presents the geographic distribution of average annual loss (USD) normalized by the
average construction costs of the respective country (USD/m2 due to ground shaking in
the residential, commercial and industrial building stock, considering contents, structural and non-structural components. The normalized metri
Authors
V. Silva, D. Amo-Oduro, A. Calderon, J. Dabbeek, V. Despotaki, L. Martins, A. Rao, M. Simionato, D. Vigano, C. Yepes, A. Acevedo, H. Crowley, Nick Horspool, Kishor S. Jaiswal, M. Journeay, M. Pittore
Geomorphic evolution of a gravel‐bed river under sediment‐starved vs. sediment‐rich conditions: River response to the world's largest dam removal
Understanding river response to sediment pulses is a fundamental problem in geomorphic process studies, with myriad implications for river management. However, because large sediment pulses are rare and usually unanticipated, they are seldom studied at field scale. We examine fluvial response to a massive (~20 Mt) sediment pulse released by the largest dam removal globally, on the Elwha River, Was
Authors
Amy E. East, Joshua B. Logan, Mark C. Mastin, Andrew C. Ritchie, Jennifer A. Bountry, Christopher S. Magirl, Joel B. Sankey
Role of fault gouge during Interaction between hydraulic fracture and a preexisting fracture
Enhanced reservoir connectivity generally requires maximizing the intersection between hydraulic fracture (HF) and preexisting underground natural fractures (NF), while having the hydraulic fracture continue to propagate across the natural fractures. Observations of downhole core samples suggest that these natural fractures are in fact veins filled with minerals such as calcite (Mighani et al., 20
Authors
S. Mighani, David A. Lockner, Brian D. Kilgore, Brian Evans
Quantifying post-wildfire hillslope erosion with lidar
Following a wildfire, flooding and debris- flow hazards are common and pose a threat to human life and infrastructure in steep burned terrain. Wildfire enhances both water runoff and soil erosion, which ultimately shape the debris flow potential. The erosional processes that route excess sediment from hillslopes to debris-flow channels in recently burned areas, however, are poorly constrained. I
Authors
Francis K. Rengers, Luke McGuire
Serpentinite‐rich gouge in a creeping segment of the Bartlett Springs Fault, northern California: Comparison with SAFOD and implications for seismic hazard
An exposure of a creeping segment of the Bartlett Springs Fault (BSF), part of the San Andreas Fault system in northern California, is a ~1.5‐m‐wide zone of serpentinite‐bearing fault gouge cutting through Late Pleistocene fluvial deposits. The fault gouge consists of porphyroclasts of antigorite serpentinite, talc, chlorite, and tremolite‐actinolite, along with some Franciscan metamorphic rocks,
Authors
Diane E. Moore, Robert J. McLaughlin, James J. Lienkaemper
Overview of spirit microscopic imager results
This paper provides an overview of Mars Exploration Rover Spirit Microscopic Imager (MI) operations and the calibration, processing, and analysis of MI data. The focus of this overview is on the last five Earth years (2005–2010) of Spirit's mission in Gusev crater, supplementing the previous overview of the first 450 sols of the Spirit MI investigation. Updates to radiometric calibration using in‐
Authors
Kenneth E. Herkenhoff, Steve W Squyres, Raymond E. Arvidson, Shoshanna B Cole, Rob Sullivan, Aileen Yingst, Nathalie Cabrol, Ella (Contractor) Lee, Janet Richie, Robert M. Sucharski, Fred J. Calef, James F. Bell, Mary Chapman, Paul Geissler, Lauren A. Edgar, Brenda Franklin, Joel A. Hurowitz, Elsa Jensen, Jeffrey R. Johnson, Randolph L. Kirk, Peter Lanagan, Kevin Mullins, Craig Leff, Justin Maki, Bonnie L. Redding, Melissa Rice, Michael H. Sims, Richard Springer, Annette Sunda, Nicole Spanovich, Laurence A. Soderblom, Alicia Vaughan
Honolulu Magnetic Observatory
Tucked in a grove of thorny mesquite trees, on an ancient coral reef on the south side of the Hawaiian island of Oahu, west of Pearl Harbor, a small unmanned observatory quietly records the Earth’s time-varying magnetic field. The Honolulu Magnetic Observatory is 1 of 14 that the U.S. Geological Survey Geomagnetism Program operates at various locations across the United States and its territories
Authors
Jeffrey J. Love, Carol Finn
The extreme space weather event in September 1909
We evaluate worldwide low-latitude auroral activity associated with the great magnetic storm of September 1909 for which a minimum Dst value of −595 nT has recently been determined. From auroral observations, we calculate that the equatorward boundary of the auroral oval in the 1909 event was in the range from 31°–35° invariant latitude (assuming auroral height of 400 km) to 37°–38° (800 km). Thes
Authors
Hisashi Hayakawa, Yusuke Ebihara, Edward W. Cliver, Kentaro Hattori, Shin Toriumi, Jeffrey J. Love, Norio Umemura, Kosuke Namekata, Takahito Sakaue, Takuya Takahashi, Kazunari Shibata