Coseismic source model of the 2003 Mw 6.8 Chengkung earthquake, Taiwan, determined from GPS measurements
K.-E. Ching, R.-J. Rau, Y. Zeng
2007, Journal of Geophysical Research B: Solid Earth (112)
A coseismic source model of the 2003 Mw 6.8 Chengkung, Taiwan, earthquake was well determined with 213 GPS stations, providing a unique opportunity to study the characteristics of coseismic displacements of a high-angle buried reverse fault. Horizontal coseismic displacements show fault-normal shortening across the fault trace. Displacements on the hanging...
Distinguishing sources of ground water recharge by using δ2H and δ18O
Kyle W. Blasch, Jeannie R. Bryson
2007, Ground Water (45) 294-308
Stable isotope values of hydrogen and oxygen from precipitation and ground water samples were compared by using a volumetrically based mixing equation and stable isotope gradient to estimate the season and location of recharge in four basins. Stable isotopes were sampled at 11 precipitation sites of differing elevation during a...
High-resolution proxy record of Holocene climate from a loess section in Southwestern Nebraska, USA
X. Miao, J.A. Mason, W.C. Johnson, Hongfang Wang
2007, Palaeogeography, Palaeoclimatology, Palaeoecology (245) 368-381
Multi-proxy analysis was used to produce a high-resolution paleoclimatic record from an exceptionally thick section of the Holocene Bignell Loess near Wauneta, Southwestern Nebraska, in the central Great Plains. The Wauneta section has excellent age control, based on optically stimulated luminescence (OSL) and radiocarbon dating, and records multiple episodes of...
On using surface-source downhole-receiver logging to determine seismic slownesses
D.M. Boore, E.M. Thompson
2007, Soil Dynamics and Earthquake Engineering (27) 971-985
We present a method to solve for slowness models from surface-source downhole-receiver seismic travel-times. The method estimates the slownesses in a single inversion of the travel-times from all receiver depths and accounts for refractions at layer boundaries. The number and location of layer interfaces in the model can be selected...
A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary
C. J. N. Wilson, D.A. Rhoades, M. A. Lanphere, A.T. Calvert, Bruce F. Houghton, S.D. Weaver, J. W. Cole
2007, Quaternary Science Reviews (26) 1861-1870
Pyroclastic fall deposits of the paired Rotoiti and Earthquake Flat eruptions from the Taupo Volcanic Zone (New Zealand) combine to form a widespread isochronous horizon over much of northern New Zealand and the southwest Pacific. This horizon is important for correlating climatic and...
Integrated ground-water monitoring strategy for NRC-licensed facilities and sites: Case study applications
V. Price, T. Temples, R. Hodges, Z. Dai, D. Watkins, J. Imrich
2007, Report
This document discusses results of applying the Integrated Ground-Water Monitoring Strategy (the Strategy) to actual waste sites using existing field characterization and monitoring data. The Strategy is a systematic approach to dealing with complex sites. Application of such a systematic approach will reduce uncertainty associated with site analysis, and therefore...
Juvenile densities relative to water regime in mainstem reservoirs of the Tennessee River, USA
L.E. Miranda, D.R. Lowery
2007, Lakes and Reservoirs: Research and Management (12) 87-96
Successful reproduction and development of strong year classes of fish in storage reservoirs are commonly associated with reproductive seasons of high water level and extensive flooding. Responses to flooding are likely to be less pronounced or altogether different in mainstem navigation reservoirs that experience limited water level fluctuation. In these...
Advanced technologies demonstrated by the miniature integrated camera and spectrometer (MICAS) aboard deep space 1
D.H. Rodgers, P.M. Beauchamp, L.A. Soderblom, R. H. Brown, G.-S. Chen, M. Lee, B.R. Sandel, D.A. Thomas, R.T. Benoit, R.V. Yelle
2007, Space Science Reviews (129) 309-326
MICAS is an integrated multi-channel instrument that includes an ultraviolet imaging spectrometer (80-185 nm), two high-resolution visible imagers (10-20 ??rad/pixel, 400-900 nm), and a short-wavelength infrared imaging spectrometer (1250-2600 nm). The wavelength ranges were chosen to maximize the science data that could be collected using existing semiconductor technologies and avoiding...
Nutrients stimulate leaf breakdown rates and detritivore biomass: Bottom-up effects via heterotrophic pathways
J.L. Greenwood, A.D. Rosemond, J.B. Wallace, W. F. Cross, H.S. Weyers
2007, Oecologia (151) 637-649
Most nutrient enrichment studies in aquatic systems have focused on autotrophic food webs in systems where primary producers dominate the resource base. We tested the heterotrophic response to long-term nutrient enrichment in a forested, headwater stream. Our study design consisted of 2 years of pretreatment data in a reference and...
High nutrient pulses, tidal mixing and biological response in a small California estuary: Variability in nutrient concentrations from decadal to hourly time scales
J.M. Caffrey, T.P. Chapin, H.W. Jannasch, J.C. Haskins
2007, Estuarine, Coastal and Shelf Science (71) 368-380
Elkhorn Slough is a small estuary in Central California, where nutrient inputs are dominated by runoff from agricultural row crops, a golf course, and residential development. We examined the variability in nutrient concentrations from decadal to hourly time scales in Elkhorn Slough to compare forcing by physical and biological factors....
Local search for optimal global map generation using mid-decadal landsat images
L. Khatib, J. Gasch, Robert Morris, S. Covington
2007, Conference Paper, AAAI Workshop - Technical Report
NASA and the US Geological Survey (USGS) are seeking to generate a map of the entire globe using Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) sensor data from the "mid-decadal" period of 2004 through 2006. The global map is comprised of thousands of scene...
Ultraviolet radiation and bio-optics in Crater Lake, Oregon
B.R. Hargreaves, S.F. Girdner, M.W. Buktenica, R.W. Collier, E. Urbach, G.L. Larson
2007, Hydrobiologia (574) 107-140
Crater Lake, Oregon, is a mid-latitude caldera lake famous for its depth (594 m) and blue color. Recent underwater spectral measurements of solar radiation (300-800 nm) support earlier observations of unusual transparency and extend these to UV-B wavelengths. New data suggest that penetration of solar UVR into Crater Lake has...
Characterization of microtopography and its influence on vegetation patterns in created wetlands
K. Moser, C. Ahn, Gregory E. Noe
2007, Wetlands (27) 1081-1097
Created wetlands are increasingly used to mitigate wetland loss. Thus, identifying wetland creation methods that enhance ecosystem development might increase the likelihood of mitigation success. Noting that the microtopographic variation found in natural wetland settings may not commonly be found in created wetlands, this study explores relationships between induced microtopography,...
Geologic mapping of the Amirani-Gish Bar region of Io: Implications for the global geologic mapping of Io
David A. Williams, Laszlo P. Keszthelyi, David A. Crown, Windy L. Jaeger, Paul M. Schenk
2007, Icarus (186) 204-217
We produced the first geologic map of the Amirani-Gish Bar region of Io, the last of four regional maps generated from Galileo mission data. The Amirani-Gish Bar region has five primary types of geologic materials: plains, mountains, patera floors, flows, and diffuse deposits. The flows and patera floors are thought...
A method to estimate groundwater depletion from confining layers
Leonard F. Konikow, Christopher E. Neuzil
2007, Water Resources Research (43)
Although depletion of storage in low‐permeability confining layers is the source of much of the groundwater produced from many confined aquifer systems, it is all too frequently overlooked or ignored. This makes effective management of groundwater resources difficult by masking how much water has been derived from storage and, in...
Grids of Agricultural Pesticide Use in the Conterminous United States, 1992
Naomi Nakagaki
2007, Report
This spatial dataset consists of 199 1-kilometer (km) resolution grids depicting estimated agricultural use of 199 pesticides in 1992 for the conterminous United States. Each grid cell value in the national grids of this dataset is the estimated total kilograms (kg) of a pesticide applied to row crops, small grain...
Grids of agricultural pesticide use in the conterminous United States, 1997
Naomi Nakagaki
2007, Report
This spatial dataset consists of 219 1-kilometer (km) resolution grids depicting estimated agricultural use of 219 pesticides in 1997 for the conterminous United States. Each grid cell value in the national grids of this dataset is the estimated total kilograms (kg) of a pesticide applied to row crops, small grain...
Anza-Terwilliger study wells in Riverside County, California
Andrew Morita, Dennis A. Clark, Peter Martin
2007, Report
This digital data set contains the locations, water-level altitude, and water-level differences of 70 wells selected to document water-level changes between fall 2004 and spring 2005 in the Anza-Terwilliger area of Riverside County, California. The winter of 2005 was one of the wettest periods on record. Links to...
High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system
G. Lipfert, W.C. Sidle, A.S. Reeve, R. A. Ayuso, A.J. Boyce
2007, Chemical Geology (242) 385-399
Ground water with high arsenic concentrations (up to 26.6????mol L- 1) has sulfate enriched in 34S and 18O in the fractured-bedrock, ground-water system of the Kelly's Cove watershed, Northport, Maine, USA. The ranges of sulfur and oxygen isotope values in aqueous sulfate, ??34S[SO4] and ??18O[SO4], at the Kelly's Cove watershed...
Habitat classification modeling with incomplete data: Pushing the habitat envelope
P.L. Zarnetske, T.C. Edwards Jr., Gretchen G. Moisen
2007, Ecological Applications (17) 1714-1726
Habitat classification models (HCMs) are invaluable tools for species conservation, land-use planning, reserve design, and metapopulation assessments, particularly at broad spatial scales. However, species occurrence data are often lacking and typically limited to presence points at broad scales. This lack of absence data precludes the use of many statistical techniques...
Evaluation of a non-point source pollution model, AnnAGNPS, in a tropical watershed
V. Polyakov, A. Fares, D. Kubo, J. Jacobi, C. Smith
2007, Environmental Modelling and Software (22) 1617-1627
Impaired water quality caused by human activity and the spread of invasive plant and animal species has been identified as a major factor of degradation of coastal ecosystems in the tropics. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized Non-Point Source Pollution Model), in...
Genetic studies of freshwater turtle and tortoises: a review of the past 70 years
Nancy N. FitzSimmons, Kristen M. Hart
2007, Conference Paper, Defining turtle diversity: proceedings of a workshop on genetics, ethics, and taxonomy of freshwater turtles and tortoises, Cambridge, Massachusetts, 8-12 August 2005
Powerful molecular techniques have been developed over many decades for resolving genetic relationships, population genetic structure, patterns of gene flow, mating systems, and the amount of genetic diversity in animals. Genetic studies of turtles were among the earliest and the rapid application of new genetic tools and analytical techniques is...
Ensuring confidence in radionuclide-based sediment chronologies and bioturbation rates
John Crusius, Timothy C. Kenna
2007, Estuarine, Coastal and Shelf Science (71) 537-544
Sedimentary records of naturally occurring and fallout-derived radionuclides are widely used as tools for estimating both the ages of recent sediments and rates of sedimentation and bioturbation. Developing these records to the point of data interpretation requires careful sample collection, processing, analysis and data modeling. In this work, we document...
Comparison of local- to regional-scale estimates of ground-water recharge in Minnesota, USA
G. N. Delin, R. W. Healy, D. L. Lorenz, J. R. Nimmo
2007, Journal of Hydrology (334) 231-249
Regional ground-water recharge estimates for Minnesota were compared to estimates made on the basis of four local- and basin-scale methods. Three local-scale methods (unsaturated-zone water balance, water-table fluctuations (WTF) using three approaches, and age dating of ground water) yielded point estimates of recharge that represent spatial scales from about 1...
Joint inversion of high-frequency surface waves with fundamental and higher modes
Y. Luo, J. Xia, J. Liu, Q. Liu, S. Xu
2007, Journal of Applied Geophysics (62) 375-384
Joint inversion of multimode surface waves for estimating the shear (S)-wave velocity has received much attention in recent years. In this paper, we first analyze sensitivity of phase velocities of multimodes of surface waves for a six-layer earth model, and then we invert surface-wave dispersion curves of the theoretical model...
