Publications
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Sizes of the largest possible earthquakes in the central and eastern United States— Summary of a workshop, September 8–9, 2008, Golden, Colorado Sizes of the largest possible earthquakes in the central and eastern United States— Summary of a workshop, September 8–9, 2008, Golden, Colorado
Most probabilistic seismic-hazard assessments require an estimate of Mmax, the magnitude (M) of the largest earthquake that is thought possible within a specified area. In seismically active areas such as some plate boundaries, large earthquakes occur frequently enough that Mmax might have been observed directly during the historical period. In less active regions like most of the...
Authors
Russell L. Wheeler
Fractures, stress and fluid flow prior to stimulation of well 27-15, Desert Peak, Nevada, EGS project Fractures, stress and fluid flow prior to stimulation of well 27-15, Desert Peak, Nevada, EGS project
A suite of geophysical logs has been acquired for structural, fluid flow and stress analysis of well 27-15 in the Desert Peak Geothermal Field, Nevada, in preparation for stimulation and development of an Enhanced Geothermal System (EGS). Advanced Logic Technologies Borehole Televiewer (BHTV) and Schlumberger Formation MicroScanner (FMS) image logs reveal extensive drilling-induced...
Authors
Nicholas C. Davatzes, Stephen H. Hickman
GPS: Applications for measuring tectonic and fault-related deformation GPS: Applications for measuring tectonic and fault-related deformation
The Global Positioning System (GPS) is a space-based Global NavigationSatellite System (GNSS). Using signals transmitted by GPS satellites, the positions of ground‐based receivers can be calculated to high precision,making it possible to track the movement of points on the Earth's surface over time. Unlike older geodetic surveying methods which involved periodicallymeasuring angles...
Authors
Jessica R. Murray
Seismic wave triggering of nonvolcanic tremor, episodic tremor and slip, and earthquakes on Vancouver Island Seismic wave triggering of nonvolcanic tremor, episodic tremor and slip, and earthquakes on Vancouver Island
[1] We explore the physical conditions that enable triggering of nonvolcanic tremor and earthquakes by considering local seismic activity on Vancouver Island, British Columbia during and immediately after the arrival of large-amplitude seismic waves from 30 teleseismic and 17 regional or local earthquakes. We identify tremor triggered by four of the teleseismic earthquakes. The close...
Authors
Justin L. Rubinstein, Joan S. Gomberg, John E. Vidale, Aaron G. Wech, Honn Kao, Kenneth C. Creager, Garry C. Rogers
Preservation of random megascale events on Mars and Earth: Influence on geologic history: GSA special papers Preservation of random megascale events on Mars and Earth: Influence on geologic history: GSA special papers
No abstract available.
Authors
Mary G. Chapman, Laszlo P. Keszthelyi
Hand-hewn granite basins at Native American saltworks, Sierra Nevada, California Hand-hewn granite basins at Native American saltworks, Sierra Nevada, California
This site in the northern Sierra Nevada contains about 369 circular basins carved in fresh, glaciated granodioritic bedrock, with 325 basins crowded together in an area of 2,700 m2 on the main terrace. These terrace basins have a median average diameter of 125 cm (80 percent between 100 and 160 cm) and a median depth of 75–80 cm. They show a strong congruity to similar granitic basins in...
Authors
James G. Moore, Michael F. Diggles
Hydrothermal processes above the Yellowstone magma chamber: Large hydrothermal systems and large hydrothermal explosions Hydrothermal processes above the Yellowstone magma chamber: Large hydrothermal systems and large hydrothermal explosions
Hydrothermal explosions are violent and dramatic events resulting in the rapid ejection of boiling water, steam, mud, and rock fragments from source craters that range from a few meters up to more than 2 km in diameter; associated breccia can be emplaced as much as 3 to 4 km from the largest craters. Hydrothermal explosions occur where shallow interconnected reservoirs of steam- and...
Authors
Lisa A. Morgan, Pat Shanks, Kenneth L. Pierce
Buckets of ash track tephra flux from Halema'uma'u Crater, Hawai'i Buckets of ash track tephra flux from Halema'uma'u Crater, Hawai'i
The 2008–2009 eruption at Kīlauea Volcano's summit made news because of its eight small discrete explosive eruptions and noxious volcanic smog (vog) created from outgassing sulfur dioxide. Less appreciated is the ongoing, weak, but continuous output of tephra, primarily ash, from the new open vent in Halema'uma'u Crater. This tephra holds clues to processes causing the eruption and...
Authors
Don Swanson, Kelly M. Wooten, Tim R. Orr
Proceedings of the XIIIth IAGA Workshop on Geomagnetic Observatory Instruments, Data Acquisition, and Processing Proceedings of the XIIIth IAGA Workshop on Geomagnetic Observatory Instruments, Data Acquisition, and Processing
The thirteenth biennial International Association of Geomagnetism and Aeronomy (IAGA) Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing was held in the United States for the first time on June 9-18, 2008. Hosted by the U.S. Geological Survey's (USGS) Geomagnetism Program, the workshop's measurement session was held at the Boulder Observatory and the...
Authors
Jeffrey J. Love
Saddle Mountain fault deformation zone, Olympic Peninsula, Washington: Western boundary of the Seattle uplift Saddle Mountain fault deformation zone, Olympic Peninsula, Washington: Western boundary of the Seattle uplift
The Saddle Mountain fault, first recognized in the early 1970s, is now well mapped in the Hoodsport area, southeastern Olympic Peninsula (northwestern United States), on the basis of light detection and ranging (LIDAR) surveys, aerial photography, and trench excavations. Drowned trees and trench excavations demonstrate that the Saddle Mountain fault produced a MW 6.5–7.0 earthquake 1000...
Authors
Richard J. Blakely, Brian L. Sherrod, Jonathan F. Hughes, Megan L. Anderson, Ray E Wells, Craig S. Weaver
Coastal change along the shore of northeastern South Carolina— The South Carolina Coastal Erosion Study Coastal change along the shore of northeastern South Carolina— The South Carolina Coastal Erosion Study
The U.S. Geological Survey, in cooperation with the South Carolina Sea Grant Consortium, conducted a 7-year, multidisciplinary study of coastal erosion in northeastern South Carolina. Shoreline behavior along the coast of Long Bay is dictated by waves, tidal currents, and sediment supply that act within the overall constraints of the regional geologic setting. Beaches are thin ribbons of...
Authors
W. C. Schwab, P. T. Gayes, R.A. Morton, N. W. Driscoll, W. E. Baldwin, W. A. Barnhardt, J. F. Denny, M.S. Harris, M.P. Katuna, T.R. Putney, G. Voulgaris, J.C. Warner, E.E. Wright
Community exposure to lahar hazards from Mount Rainier, Washington Community exposure to lahar hazards from Mount Rainier, Washington
Geologic evidence of past events and inundation modeling of potential events suggest that lahars associated with Mount Rainier, Washington, are significant threats to downstream development. To mitigate potential impacts of future lahars and educate at-risk populations, officials need to understand how communities are vulnerable to these fast-moving debris flows and which individuals and
Authors
Nathan J. Wood, Christopher E. Soulard