Publications
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Geomorphic and vegetation processes of the Willamette River floodplain, Oregon: current understanding and unanswered science questions
This report summarizes the current understanding of floodplain processes and landforms for the Willamette River and its major tributaries. The area of focus encompasses the main stem Willamette River above Newberg and the portions of the Coast Fork Willamette, Middle Fork Willamette, McKenzie, and North, South and main stem Santiam Rivers downstream of U.S. Army Corps of Engineers dams. These reac
Authors
J. Rose Wallick, Krista L. Jones, Jim E. O'Connor, Mackenzie K. Keith, David Hulse, Stanley V. Gregory
Long-range hazard assessment of volcanic ash dispersal for a Plinian eruptive scenario at Popocatépetl volcano (Mexico): implications for civil aviation safety
Popocatépetl is one of Mexico’s most active volcanoes threatening a densely populated area that includes Mexico City with more than 20 million inhabitants. The destructive potential of this volcano is demonstrated by its Late Pleistocene–Holocene eruptive activity, which has been characterized by recurrent Plinian eruptions of large magnitude, the last two of which destroyed human settlements in p
Authors
Rosanna Bonasia, Chirara Scaini, Lucia Capra, Manuel Nathenson, Claus Siebe, Lilia Arana-Salinas, Arnau Folch
Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA
We present chemical and isotopic data for fluids, minerals and rocks from the Long Valley meteoric-hydrothermal system. The samples encompass the presumed hydrothermal upwelling zone in the west moat of the caldera, the Casa Diablo geothermal field, and a series of wells defining a nearly linear, ∼16 km long, west-to-east trend along the likely fluid flow path. Fluid samples were analyzed for the
Authors
Shaun T. Brown, B. Mack Kennedy, Donald J. DePaolo, Shaul Hurwitz, William C. Evans
Compaction and gas loss in welded pyroclastic deposits as revealed by porosity, permeability, and electrical conductivity measurements of the Shevlin Park Tuff
Pyroclastic flows produced by large volcanic eruptions commonly densify after emplacement. Processes of gas escape, compaction, and welding in pyroclastic-flow deposits are controlled by the physical and thermal properties of constituent material. Through measurements of matrix porosity, permeability, and electrical conductivity, we provide a framework for understanding the evolution of pore struc
Authors
Heather M. Wright, Katharine V. Cashman
Early and late Holocene glacial fluctuations and tephrostratigraphy, Cabin Lake, Alaska
Marked changes in sediment types deposited in Cabin Lake, near Cordova, Alaska, represent environmental shifts during the early and late Holocene, including fluctuations in the terminal position of Sheridan Glacier. Cabin Lake is situated to receive meltwater during periods when the outwash plain of the advancing Sheridan Glacier had aggraded. A brief early Holocene advance from 11.2 to 11.0 cal k
Authors
Paul D. Zander, Darrell S. Kaufman, Stephen C. Kuehn, Kristi L. Wallace, R. Scott Anderson
Extreme CO2 disturbance and the resilience of soil microbial communities
Carbon capture and storage (CSS) technology has the potential to inadvertently release large quantities of CO2 through geologic substrates and into surrounding soils and ecosystems. Such a disturbance has the potential to not only alter the structure and function of plant and animal communities, but also soils, soil microbial communities, and the biogeochemical processes they mediate. At Mammoth
Authors
Jack W. McFarland, Mark P. Waldrop, Monica Haw
Advances in natural hazard science and assessment, 1963-2013
No abstract available.
Authors
Mary Lou Zoback, Eric Geist, John Pallister, David P. Hill, Simon Young, Wendy McCausland
The late Holocene dry period: multiproxy evidence for an extended drought between 2800 and 1850 cal yr BP across the central Great Basin, USA
Evidence of a multi-centennial scale dry period between ∼2800 and 1850 cal yr BP is documented by pollen, mollusks, diatoms, and sediment in spring sediments from Stonehouse Meadow in Spring Valley, eastern central Nevada, U.S. We refer to this period as the Late Holocene Dry Period. Based on sediment recovered, Stonehouse Meadow was either absent or severely restricted in size at ∼8000 cal yr BP.
Authors
Scott A. Mensing, Saxon E. Sharpe, Irene Tunno, Don W. Sada, Jim M. Thomas, Scott W. Starratt, Jeremy Smith
Composition and origin of rhyolite melt intersected by drilling in the Krafla geothermal field, Iceland
The Iceland Deep Drilling Project Well 1 was designed as a 4- to 5-km-deep exploration well with the goal of intercepting supercritical hydrothermal fluids in the Krafla geothermal field, Iceland. The well unexpectedly drilled into a high-silica (76.5 % SiO2) rhyolite melt at approximately 2.1 km. Some of the melt vesiculated while extruding into the drill hole, but most of the recovered cuttings
Authors
R.A. Zierenberg, P. Schiffman, G.H. Barfod, C.E. Lesher, N.E. Marks, Jacob B. Lowenstern, A.K. Mortensen, E.C. Pope, D.K. Bird, M.H. Reed, G.O. Friðleifsson, W.A. Elders
Rangewide glaciation in the Sierra Nevada, California
The 600-km-long Sierra Nevada underwent extensive Pleistocene glaciation except for its southernmost 100 km. Presently, ∼1700 small glaciers and ice masses near the crest of the range occur above 3250 m in elevation; these covered an area of ∼50 km2 in 1972. Fourteen of the largest glaciers decreased by about one half in area during the period from 1900 to 2004.Rock glaciers, generally glacial ice
Authors
James G. Moore, Barry C. Moring
Moderate-magnitude earthquakes induced by magma reservoir inflation at Kīlauea Volcano, Hawai‘i
Although volcano-tectonic (VT) earthquakes often occur in response to magma intrusion, it is rare for them to have magnitudes larger than ~M4. On 24 May 2007, two shallow M4+ earthquakes occurred beneath the upper part of the east rift zone of Kīlauea Volcano, Hawai‘i. An integrated analysis of geodetic, seismic, and field data, together with Coulomb stress modeling, demonstrates that the earthqua
Authors
Christelle Wauthier, Diana C. Roman, Michael P. Poland
Response of diatoms and silicoflagellates to climate change in the Santa Barbara Basin during the past 250 years and the rise of the toxic diatom Pseudo-nitzschia australis
Diatoms and silicoflagellate assemblages were examined in two year-increments of varved samples spanning the interval from 1748 through 2007 in Santa Barbara Basin (SBB) box core SBBC0806 to determine the timing and impact of possible 20th century warming on several different components of the plankton. Diatoms (Thalassionema nitzschioides =TN) and silicoflagellates (Distephanus speculum s.l. =DS)
Authors
John A. Barron, David Bukry, David B. Field, Bruce Finney