Publications
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Impacts of the 2004 Indian ocean tsunami on the southwest coasts of Sri Lanka Impacts of the 2004 Indian ocean tsunami on the southwest coasts of Sri Lanka
The 2004 Indian Ocean tsunami caused major landscape changes along the southwest coasts of Sri Lanka that were controlled by the flow, natural topography and bathymetry, and anthropogenic modifications of the terrain. Landscape changes included substantial beach erosion and scouring of return-flow channels near the beach, and deposition of sand sheets across the narrow coastal plain. In...
Authors
Robert A. Morton, John A. Goff, Scott L. Nichol
THEMIS observes possible cave skylights on Mars THEMIS observes possible cave skylights on Mars
Seven possible skylight entrances into Martian caves were observed on and around the flanks of Arsia Mons by the Mars Odyssey Thermal Emission Imaging System (THEMIS). Distinct from impact craters, collapse pits or any other surface feature on Mars, these candidates appear to be deep dark holes at visible wavelengths while infrared observations show their thermal behaviors to be...
Authors
Glen Cushing, Timothy N. Titus, J. Judson Wynne, P. R. Christensen
Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska
Tephra-fall deposits from Cook Inlet volcanoes were detected in sediment cores from Tustumena and Paradox Lakes, Kenai Peninsula, Alaska, using magnetic susceptibility and petrography. The ages of tephra layers were estimated using 21 14C ages on macrofossils. Tephras layers are typically fine, gray ash, 1–5 mm thick, and composed of varying proportions of glass shards, pumice, and glass...
Authors
C.S. de Fontaine, D. S. Kaufman, Anderson R. Scott, A. Werner, Christopher F. Waythomas, T.A. Brown
Rip currents, mega-cusps, and eroding dunes Rip currents, mega-cusps, and eroding dunes
Dune erosion is shown to occur at the embayment of beach mega-cusps O(200 m alongshore) that are associated with rip currents. The beach is the narrowest at the embayment of the mega-cusps allowing the swash of large storm waves coincident with high tides to reach the toe of the dune, to undercut the dune and to cause dune erosion. Field measurements of dune, beach, and rip current...
Authors
E.B. Thornton, J. MacMahan, A. H. Sallenger
Writing on the walls: Geological context and early American spiritual beliefs Writing on the walls: Geological context and early American spiritual beliefs
Native American culture in many parts of California is preserved in fragmentary oral and conventional written histories, but also in sometimes dramatic petroglyphs and pictographs throughout the state. The symbolism of these images has been interpreted to reflect the natural environment, in particular issues related to rain. Although there is little doubt that rain was of paramount...
Authors
S. E. Hough
Massive edifice failure at Aleutian arc volcanoes Massive edifice failure at Aleutian arc volcanoes
Along the 450-km-long stretch of the Aleutian volcanic arc from Great Sitkin to Kiska Islands, edifice failure and submarine debris-avalanche deposition have occurred at seven of ten Quaternary volcanic centers. Reconnaissance geologic studies have identified subaerial evidence for large-scale prehistoric collapse events at five of the centers (Great Sitkin, Kanaga, Tanaga, Gareloi, and...
Authors
Michelle L. Coombs, S.M. White, D.W. Scholl
Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline
Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust...
Authors
Dale W. Griffin, Nilgun Kubilay, Mustafa Kocak, Mike A. Gray, Timothy C. Borden, Eugene A. Shinn
A closer look at water-related geologic activity on Mars A closer look at water-related geologic activity on Mars
Water has supposedly marked the surface of Mars and produced characteristic landforms. To understand the history of water on Mars, we take a close look at key locations with the High-Resolution Imaging Science Experiment on board the Mars Reconnaissance Orbiter, reaching fine spatial scales of 25 to 32 centimeters per pixel. Boulders ranging up to ∼2 meters in diameter are ubiquitous in...
Authors
Alfred S. McEwen, C.J. Hansen, W.A. Delamere, E. M. Eliason, Kenneth E. Herkenhoff, Laszlo P. Keszthelyi, V. C. Gulick, Randolph L. Kirk, M. T. Mellon, J. A. Grant, N. Thomas, C.M. Weitz, S. W. Squyres, N.T. Bridges, S.L. Murchie, F. Seelos, K. Seelos, C.H. Okubo, M.P. Milazzo, L.L. Tornabene, W.L. Jaeger, S. Byrne, P.S. Russell, J.L. Griffes, S. Martinez-Alonso, A. Davatzes, F. C. Chuang, B.J. Thomson, K.E. Fishbaugh, C. M. Dundas, K.J. Kolb, M. E. Banks, J.J. Wray
Altered mangrove wetlands as habitat for estuarine nekton: are dredged channels and tidal creeks equivalent? Altered mangrove wetlands as habitat for estuarine nekton: are dredged channels and tidal creeks equivalent?
Hasty decisions are often made regarding the restoration of "altered" habitats, when in fact the ecological value of these habitats may be comparable to natural ones. To assess the "value" of altered mangrove-lined habitats for nekton, we sampled for 1 yr within three Tampa Bay wetlands. Species composition, abundance, and spatial distribution of nekton assemblages in permanent subtidal...
Authors
Justin M. Krebs, Adam B. Brame, Carole C. McIvor
Restoring coastal wetlands that were ditched for mosquito control: a preliminary assessment of hydro-leveling as a restoration technique Restoring coastal wetlands that were ditched for mosquito control: a preliminary assessment of hydro-leveling as a restoration technique
The wetlands surrounding Tampa Bay, Florida were extensively ditched for mosquito control in the 1950s. Spoil from ditch construction was placed adjacent to the wetlands ditches creating mound-like features (spoil-mounds). These mounds represent a loss of 14% of the wetland area in Tampa Bay. Spoil mounds interfere with tidal flow and are locations for non-native plants to colonize (e.g...
Authors
Thomas J. Smith, Ginger Tiling, Pamela S. Leasure
Post-earthquake investigations-exercising the NEHRP plan and development of a virtual clearinghouse concept Post-earthquake investigations-exercising the NEHRP plan and development of a virtual clearinghouse concept
No abstract available.
Authors
Thomas L. Holzer, Christopher Rojahn, Charles Scawthorn
Liquemap: A real-time post-earthquake map of liquefaction probability Liquemap: A real-time post-earthquake map of liquefaction probability
No abstract available.
Authors
Michael J. Bennett, Luke Blair, Thomas L. Holzer, Thomas E. Noce