Publications
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Sediment compaction rates and subsidence in deltaic plains: Numerical constraints and stratigraphic influences Sediment compaction rates and subsidence in deltaic plains: Numerical constraints and stratigraphic influences
Natural sediment compaction in deltaic plains influences subsidence rates and the evolution of deltaic morphology. Determining compaction rates requires detailed knowledge of subsurface geotechnical properties and depositional history, neither of which is often readily available. To overcome this lack of knowledge, we numerically forward model the incremental sedimentation and compaction...
Authors
T.A. Meckel, Uri S. ten Brink, S.J. Williams
Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper
The Cassini Titan Radar Mapper obtained Synthetic Aperture Radar images of Titan's surface during four fly-bys during the mission's first year. These images show that Titan's surface is very complex geologically, showing evidence of major planetary geologic processes, including cryovolcanism. This paper discusses the variety of cryovolcanic features identified from SAR images, their...
Authors
Rosaly Lopes, K. L. Mitchell, Ellen R. Stofan, Jonathan I. Lunine, Ralf D. Lorenz, F. Paganelli, Randolph L. Kirk, C. A. Wood, Stephen D. Wall, L.E. Robshaw, A.D. Fortes, Catherine D. Neish, Jani Radebaugh, E. Reffet, S.J. Ostro, Charles Elachi, M.D. Allison, Y. Anderson, R. Boehmer, G. Boubin, Philip S. Callahan, P. Encrenaz, E. Flamini, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, Michael A. Janssen, W.T.K. Johnson, K. Kelleher, D.O. Muhleman, G. Ori, R. Orosei, G. Picardi, F. Posa, L.E. Roth, R. Seu, S. Shaffer, Laurence A. Soderblom, B. Stiles, S. Vetrella, R.D. West, L. Wye, H. A. Zebker
Forecast experiment: do temporal and spatial b value variations along the Calaveras fault portend M ≥ 4.0 earthquakes? Forecast experiment: do temporal and spatial b value variations along the Calaveras fault portend M ≥ 4.0 earthquakes?
The power law distribution of earthquake magnitudes and frequencies is a fundamental scaling relationship used for forecasting. However, can its slope (b value) be used on individual faults as a stress indicator? Some have concluded that b values drop just before large shocks. Others suggested that temporally stable low b value zones identify future large-earthquake locations. This study...
Authors
Tom Parsons
Tsunami warnings: Understanding in Hawai'i Tsunami warnings: Understanding in Hawai'i
The devastating southeast Asian tsunami of December 26, 2004 has brought home the destructive consequences of coastal hazards in an absence of effective warning systems. Since the 1946 tsunami that destroyed much of Hilo, Hawai‘i, a network of pole mounted sirens has been used to provide an early public alert of future tsunamis. However, studies in the 1960s showed that understanding of...
Authors
Chris E. Gregg, Bruce F. Houghton, Douglas Paton, David M. Johnston, David A. Swanson, B.S. Yanagi
Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska
The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6 km below sea level and encompasses all of the Katmai volcanoes; Martin...
Authors
A.D. Jolly, S.C. Moran, S.R. McNutt, D.B. Stone
Implications of the 26 December 2004 Sumatra-Andaman earthquake on tsunami forecast and assessment models for great subduction-zone earthquakes Implications of the 26 December 2004 Sumatra-Andaman earthquake on tsunami forecast and assessment models for great subduction-zone earthquakes
Results from different tsunami forecasting and hazard assessment models are compared with observed tsunami wave heights from the 26 December 2004 Indian Ocean tsunami. Forecast models are based on initial earthquake information and are used to estimate tsunami wave heights during propagation. An empirical forecast relationship based only on seismic moment provides a close estimate to the...
Authors
Eric L. Geist, Vasily V. Titov, Diego Arcas, Fred F. Pollitz, Susan L. Bilek
Why the sacramento delta area differs from other parts of the great valley: numerical modeling of thermal structure and thermal subsidence of forearc basins Why the sacramento delta area differs from other parts of the great valley: numerical modeling of thermal structure and thermal subsidence of forearc basins
Data on present-day heat flow, subsidence history, and paleotemperature for the Sacramento Delta region, California, have been employed to constrain a numerical model of tectonic subsidence and thermal evolution of forearc basins. The model assumes an oceanic basement with an initial thermal profile dependent on its age subjected to refrigeration caused by a subducting slab. Subsidence...
Authors
V.O. Mikhailov, T. Parsons, R.W. Simpson, E.P. Timoshkina, C. Williams
Accelerated uplift and magmatic intrusion of the Yellowstone caldera, 2004 to 2006 Accelerated uplift and magmatic intrusion of the Yellowstone caldera, 2004 to 2006
The Yellowstone caldera began a rapid episode of ground uplift in mid-2004, revealed by Global Positioning System and interferometric synthetic aperture radar measurements, at rates up to 7 centimeters per year, which is over three times faster than previously observed inflation rates. Source modeling of the deformation data suggests an expanding volcanic sill of ???1200 square...
Authors
Wu-Lung Chang, Robert B. Smith, Charles Wicks, J.M. Farrell, C.M. Puskas
Windy Mars: A dynamic planet as seen by the HiRISE camera Windy Mars: A dynamic planet as seen by the HiRISE camera
With a dynamic atmosphere and a large supply of particulate material, the surface of Mars is heavily influenced by wind-driven, or aeolian, processes. The High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO) provides a new view of Martian geology, with the ability to see decimeter-size features. Current sand movement, and evidence for recent...
Authors
Nathan T. Bridges, Paul E. Geissler, Alfred S. McEwen, B.J. Thomson, Frank C. Chuang, Kenneth E. Herkenhoff, Laszlo P. Keszthelyi, Sara Martinez-Alonso
Sandy signs of a tsunami's onshore depth and speed Sandy signs of a tsunami's onshore depth and speed
Tsunamis rank among the most devastating and unpredictable natural hazards to affect coastal areas. Just 3 years ago, in December 2004, the Indian Ocean tsunami caused more than 225,000 deaths. Like many extreme events, however, destructive tsunamis strike rarely enough that written records span too little time to quantify tsunami hazard and risk. Tsunami deposits preserved in the...
Authors
K. Huntington, J. Bourgeois, G. Gelfenbaum, P. Lynett, B. Jaffe, H. Yeh, R. Weiss
Spatial and temporal variability in oceanographic and meteorologic forcing along Central California and its implications on nearshore processes Spatial and temporal variability in oceanographic and meteorologic forcing along Central California and its implications on nearshore processes
In the past two decades, the understanding of the important large-scale phenomena (El Niño, upwelling, California current, etc) that drive physical, chemical, and biological processes along the US West Coast has greatly improved. However, the ability to predict the influence of annual and inter-annual events on a regional scale still remains limited. High-resolution hourly data from 6...
Authors
D.K. Wingfield, C. D. Storlazzi
Forcing of large-scale cycles of coastal change at the entrance to Willapa Bay, Washington Forcing of large-scale cycles of coastal change at the entrance to Willapa Bay, Washington
Anomalous morphological features within large estuaries may be: (1) recorders of external forces that periodically overwhelm the normal morphodynamic responses to estuarine energy fluxes, and (2) possible predictors of cycles of future coastal change. At the entrance to Willapa Bay, Washington, chronic beach erosion and frequent coastal flooding are related to the historical northward...
Authors
Robert A. Morton, H. Edward Clifton, Noreen A. Buster, Russell L. Peterson, Guy Gelfenbaum