Publications
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Disk-integrated thermal properties of Ceres measured at the millimeter wavelengths
We observed Ceres at three epochs in 2015 November and 2017 September and October with Atacama Large Millimeter/submillimeter Array (ALMA) 12 m array and in 2017 October with the ALMA Compact Array (ACA), all at ~265 GHz continuum (wavelengths of ~1.1 mm) to map the temperatures of Ceres over a full rotation at each epoch. We also used 2017 October ACA observations to search for HCN. The disk-aver
Authors
Jian-Yang Li, Arielle Moullet, Timothy N. Titus, Henry H. Hsieh, Mark V. Sykes
Methods for rapidly estimating velocity precision from GNSS time series in the presence of temporal correlation: A new method and comparison of existing methods
Time series of position estimates from Global Navigational Satellite System (GNSS) are used to measure the velocities of points on the surface of the Earth. Along with the velocity estimates, a measure of the precision is needed to assess the quality of the velocity measurement. Here, I evaluate rate uncertainties provided by four different methods that have been applied to geodetic time series. T
Authors
John Langbein
Genesis and evolution of ferromanganese crusts from the summit of Rio Grande Rise, southwest Atlantic Ocean
The Rio Grande Rise (RGR) is a large elevation in the Atlantic Ocean and known to host potential mineral resources of ferromanganese crusts (Fe–Mn), but no investigation into their general characteristics have been made in detail. Here, we investigate the chemical and mineralogical composition, growth rates and ages of initiation, and phosphatization of relatively shallow-water (650–825 m) Fe–Mn c
Authors
Mariana Benites, James R. Hein, Kira Mizell, Terrence Blackburn, Luigi Jovane
Practical limitations of Earthquake Early Warning
Earthquake Early Earning (EEW) entails detection of initial earthquake shaking and rapid estimation and notification to users prior to imminent, stronger shaking. EEW is coming to the U.S. West Coast. But what are the technical and social challenges to delivering actionable information on earthquake shaking before it arrives? Although there will be tangible benefits, there are also limitations. Ba
Authors
David J. Wald
USGS “Did You Feel It?” — Science and lessons from twenty years of citizen science-based macroseismology
The U.S. Geological Survey (USGS) “Did You Feel It?” (DYFI) system is an automatic method for rapidly collecting macroseismic intensity data from Internet users’ shaking and damage reports and for generating intensity maps immediately following felt earthquakes. DYFI has been in operation for nearly two decades (1999-2019) in the United States, and for nearly 15 years globally. During that period
Authors
Vince Quitoriano, David J. Wald
How processing methodologies can distort and bias power spectral density estimates of seismic background noise
Power spectral density (PSD) estimates are widely used in seismological studies to characterize background noise conditions, assess instrument performance, and study quasi‐stationary signals that are difficult to observe in the time domain. However, these studies often utilize different processing techniques, each of which can inherently bias the resulting PSD estimates. The level of smoothing, th
Authors
Robert E. Anthony, Adam T. Ringler, David C. Wilson, Manochehr Bahavar, Keith D. Koper
Earthquake early warning ShakeAlert 2.0: Public rollout
The ShakeAlert Earthquake Early Warning System is designed to automatically identify and characterize the initiation and rupture evolution of large earthquakes, estimate the intensity of ground shaking that will result, and deliver alerts to people and systems that may experience shaking, prior to the occurrence of shaking at their location. It is configured to issue alerts to locations within the
Authors
Monica Kohler, Deborah E. Smith, Jennifer Andrews, Angela I. Chung, Renate Hartog, Ivan Henson, Doug Given, Robert Michael deGroot, Stephen Robert Guiwits
Seismic and geodetic progression of the 2018 summit caldera collapse of Kīlauea Volcano
The 2018 eruption of Kīlauea volcano, Hawaiʻi, resulted in a major collapse of the summit caldera along with an effusive eruption in the lower East Rift Zone. The caldera collapse comprised 62 highly similar collapse cycles of strong ground deformation and earthquake swarms that ended with a magnitude 5 collapse event and one partial cycle that did not end with a collapse event. We analyzed geodet
Authors
Gabrielle Tepp, Alicia J. Hotovec-Ellis, Brian Shiro, Ingrid Johanson, Weston Thelen, Matthew M. Haney
Ground-motion predictions for California — Comparisons of three prediction equations
We systematically evaluate datasets, functional forms, independent parameters of estimation, and resulting ground-motion predictions (as median and aleatory variability) of the Graizer and Kalkan (2015, 2016) (GK15) ground-motion prediction equation (GMPE) with the next generation of attenuation project (NGA-West2) models of Abrahamson and others (2014) (ASK14) and Boore and others (2014) (BSSA14)
Authors
Erol Kalkan, Vladimir Graizer
Probabilistic regional-scale liquefaction triggering modeling using 3D Gaussian processes
Liquefaction is a major cause of coseismic damages, occurring irregularly over hundreds or thousands of square kilometers in large earthquakes. Large variations in the extent and location of liquefaction have been observed in recent earthquakes, motivating the need for prediction methods that consider the spatial heterogeneity of geologic deposits at a regional scale. Contemporary regional-scale l
Authors
Michael Greenfield, Alex R. R. Grant
Runoff-initiated post-fire debris flow Western Cascades, Oregon
Wildfires dramatically alter the hydraulics and root reinforcement of soil on forested hillslopes, which can promote the generation of debris flows. In the Pacific Northwest, post-fire shallow landsliding has been well documented and studied, but the potential role of runoff-initiated debris flows is not well understood and only one previous to 2018 had been documented in the region. On 20 June 20
Authors
Sara Wall, J.J. Roering, Francis K. Rengers
Regionally Optimized Background Earthquake Rates from ETAS (ROBERE) for probabilistic seismic hazard assessment
We use an epidemic‐type aftershock sequence (ETAS) based approach to develop a regionally optimized background earthquake rates from ETAS (ROBERE) method for probabilistic seismic hazard assessment. ROBERE fits parameters to the full seismicity catalog for a region with maximum‐likelihood estimation, including uncertainty. It then averages the earthquake rates over a suite of catalogs from which f
Authors
Andrea L. Llenos, Andrew J. Michael