Skip to main content
U.S. flag

An official website of the United States government

Conference Papers

Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.

Filter Total Items: 5547

Field investigation of the drift shadow Field investigation of the drift shadow

The "Drift Shadow" is defined as the relatively drier region that forms below subsurface cavities or drifts in unsaturated rock. Its existence has been predicted through analytical and numerical models of unsaturated flow. However, these theoretical predictions have not been demonstrated empirically to date. In this project we plan to test the drift shadow concept through field...
Authors
G.W. Su, T.J. Kneafsey, T.A. Ghezzehei, P.J. Cook, B.D. Marshall

Field tests of acoustic telemetry for a portable coastal observatory Field tests of acoustic telemetry for a portable coastal observatory

Long-term field tests of a low-cost acoustic telemetry system were carried out at two sites in Massachusetts Bay. At each site, an acoustic Doppler current profiler mounted on a bottom tripod was fitted with an acoustic modem to transmit data to a surface buoy; electronics mounted on the buoy relayed these data to shore via radio modem. The mooring at one site (24 m water depth) was...
Authors
M. Martini, B. Butman, J. Ware, D. Frye

Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana

Redheads, Aythya americana, concentrate in large numbers annually in traditional wintering areas along the western and northern rim of the Gulf of Mexico. Two of these areas are the Laguna Madre of Texas and Chandeleur Sound of Louisiana. We collected data on 54,340 activities from 103 redhead flocks in Texas and 51,650 activities from 57 redhead flocks in Louisiana. Males and females...
Authors
M.C. Woodin, T.C. Michot

Forecasting runout of rock and debris avalanches Forecasting runout of rock and debris avalanches

Physically based mathematical models and statistically based empirical equations each may provide useful means of forecasting runout of rock and debris avalanches. This paper compares the foundations, strengths, and limitations of a physically based model and a statistically based forecasting method, both of which were developed to predict runout across three-dimensional topography. The...
Authors
Richard M. Iverson

Foreword: Understanding through modeling Foreword: Understanding through modeling

[No abstract available]
Authors
C. Zheng, E. Poeter, M. Hill, J. Doherty

Fracture in Westerly granite under AE feedback and constant strain rate loading: Nucleation, quasi-static propagation, and the transition to unstable fracture propagation Fracture in Westerly granite under AE feedback and constant strain rate loading: Nucleation, quasi-static propagation, and the transition to unstable fracture propagation

New observations of fracture nucleation are presented from three triaxial compression experiments on intact samples of Westerly granite, using Acoustic Emission (AE) monitoring. By conducting the tests under different loading conditions, the fracture process is demonstrated for quasi-static fracture (under AE Feedback load), a slowly developing unstable fracture (loaded at a 'slow'...
Authors
B.D. Thompson, R.P. Young, D.A. Lockner

Future for polar bears in a declining sea ice environment: What do we know? Future for polar bears in a declining sea ice environment: What do we know?

During an April 22, 2006, interview on the CBC radio program “The House,” Tim Flannery, author of the recent book “The Weathermakers,” stated, “Projections of the polar bear specialists are that by about 2030, around that date, the species will be extinct because of global warming induced changes in the Arctic sea ice.” That statement was followed on May 4th by quotations in the Toronto...
Authors
Steven C. Amstrup

Gaussian-based filters for detecting Martian dust devils Gaussian-based filters for detecting Martian dust devils

The ability to automatically detect dust devils in the Martian atmosphere from orbital imagery is becoming important both for scientific studies of the planet and for the planning of future robotic and manned missions. This paper describes our approach for the unsupervised detection of dust devils and the preliminary results achieved to date. The algorithm centers upon the use of a...
Authors
F. Yang, P.A. Mlsna, P. Geissler

Geochronology and tectonic significance of Middle Proterozoic granitic orthogneiss, North Qaidam HP/UHP terrane, Western China Geochronology and tectonic significance of Middle Proterozoic granitic orthogneiss, North Qaidam HP/UHP terrane, Western China

Amphibolite-facies para- and orthogneisses near Dulan, in the southeast part of the North Qaidam terrane, enclose minor ultra-high pressure (UHP) eclogite and peridotite. Field relations and coesite inclusions in zircons from paragneiss suggest that felsic, mafic, and ultramafic rocks all experienced UHP metamorphism and a common amphibolite-facies retrogression. Ion microprobe U-Pb and...
Authors
C.G. Mattinson, J. L. Wooden, J. G. Liou, D.K. Bird, C.L. Wu

Geodetic antenna calibration test in the Antarctic environment Geodetic antenna calibration test in the Antarctic environment

TransAntarctic Mountain DEFormation (TAMDEF) Monitoring Network is the NSF-sponsored OSU and USGS project, aimed at measuring crustal motion in the Transantarctic Mountains of Victoria Land using GPS carrier phase measurements. Station monumentation, antenna mounts, antenna types, and data processing strategies were optimized to achieve mm-level estimates for the rates of motion. These...
Authors
A. Grejner-Brzezinska, E. Vazquez, L. Hothem

Geologic impacts of the 2004 Indian ocean tsunami on Indonesia, Sri Lanka, and the Maldives Geologic impacts of the 2004 Indian ocean tsunami on Indonesia, Sri Lanka, and the Maldives

The December 26, 2004 Indian Ocean tsunami was generated by a large submarine earthquake (magnitude ???9.1) with an epicenter located under the seafloor in the eastern Indian Ocean near northern Sumatra, Indonesia. The resulting tsunami was measured globally and had significant geologic impacts throughout the Indian Ocean basin. Observations of tsunami impacts, such as morphologic change
Authors
B. M. Richmond, B. E. Jaffe, G. Gelfenbaum, R.A. Morton
Was this page helpful?