Wetland vegetation in Manzala lagoon, Nile Delta coast, Egypt: Rapid responses of pollen to altered nile hydrology and land use
C.E. Bernhardt, J.-D. Stanley, B. P. Horton
2011, Journal of Coastal Research (27) 731-737
The pollen record in a sediment core from Manzala lagoon on the Nile delta coastal margin of Egypt, deposited from ca. AD 1860 to 1990, indicates rapid coastal wetland vegetation responses to two primary periods of human activity. These are associated with artificially altered Nile hydrologic regimes in proximal areas and distal...
Geology, geochronology, and paleogeography of the southern Sonoma volcanic field and adjacent areas, northern San Francisco Bay region, California
David L. Wagner, George J. Saucedo, Kevin B. Clahan, Robert J. Fleck, Victoria E. Langenheim, Robert J. McLaughlin, Andrei M. Sarna-Wojcicki, James R. Allen, Alan L. Deino
2011, Geosphere (7) 658-683
Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that...
Effects of fringing reefs on tsunami inundation: American Samoa
G. Gelfenbaum, A. Apotsos, A.W. Stevens, B. Jaffe
2011, Earth-Science Reviews (107) 12-22
A numerical model of tsunami inundation, Delft3D, which has been validated for the 29 September 2009 tsunami in Tutuila, American Samoa, is used to better understand the impact of fringing coral reefs and embayments on tsunami wave heights, inundation distances, and velocities. The inundation model is used to explore the...
Nitrogen uptake by the shoots of smooth cordgrass Spartina alterniflora
T. J. Mozdzer, M. Kirwan, K. J. McGlathery, J. C. Zieman
2011, Marine Ecology Progress Series (433) 43-52
The smooth cordgrass Spartina alterniflora is the foundation species in intertidal salt marshes of the North American Atlantic coast. Depending on its elevation within the marsh, S. alterniflora may be submerged for several hours per day. Previous ecosystem-level studies have demonstrated that S. alterniflora marshes are a net sink for nitrogen (N), and that removal of...
The indication of Martian gully formation processes by slope-area analysis
Susan J. Conway, Matthew R. Balme, John B. Murray, Martin C. Towner, Chris Okubo, Peter M. Grindrod
2011, Geological Society Special Publication (356) 171-201
The formation process of recent gullies on Mars is currently under debate. This study aims to discriminate between the proposed formation processes - pure water flow, debris flow and dry mass wasting - through the application of geomorphological indices commonly used in terrestrial geomorphology. High-resolution digital elevation models (DEMs) of...
Mapping rice areas of South Asia using MODIS multitemporal data
M.K. Gumma, A. Nelson, P.S. Thenkabail, A.N. Singh
2011, Journal of Applied Remote Sensing (5)
Our goal is to map the rice areas of six South Asian countries using moderate-resolution imaging spectroradiometer (MODIS) time-series data for the time period 2000 to 2001. South Asia accounts for almost 40% of the world's harvested rice area and is also home to 74% of the population that lives...
Seawater calcium isotope ratios across the Eocene-Oligocene transition
E.M. Griffith, A. Paytan, A. Eisenhauer, Thomas D. Bullen, E. Thomas
2011, Geology (39) 683-686
During the Eocene-Oligocene transition (EOT, ca. 34 Ma), Earth's climate cooled significantly from a greenhouse to an icehouse climate, while the calcite (CaCO3) compensation depth (CCD) in the Pacific Ocean increased rapidly. Fluctuations in the CCD could result from various processes that create an imbalance between calcium (Ca) sources to,...
Adaptive finite volume methods with well-balanced Riemann solvers for modeling floods in rugged terrain: Application to the Malpasset dam-break flood (France, 1959)
D.L. George
2011, International Journal for Numerical Methods in Fluids (66) 1000-1018
The simulation of advancing flood waves over rugged topography, by solving the shallow-water equations with well-balanced high-resolution finite volume methods and block-structured dynamic adaptive mesh refinement (AMR), is described and validated in this paper. The efficiency of block-structured AMR makes large-scale problems tractable, and allows the use of accurate and...
Effects of dynamically variable saturation and matrix-conduit coupling of flow in karst aquifers
Thomas Reimann, T. Geyer, W.B. Shoemaker, R. Liedl, M. Sauter
2011, Water Resources Research (47)
Well-developed karst aquifers consist of highly conductive conduits and a relatively low permeability fractured and/or porous rock matrix and therefore behave as a dual-hydraulic system. Groundwater flow within highly permeable strata is rapid and transient and depends on local flow conditions, i.e., pressurized or nonpressurized flow. The characterization of karst...
Potential misuse of avian density as a conservation metric
Susan K. Skagen, Amy A. Yackel Adams
2011, Conservation Biology (25) 48-55
: Effective conservation metrics are needed to evaluate the success of management in a rapidly changing world. Reproductive rates and densities of breeding birds (as a surrogate for reproductive rate) have been used to indicate the quality of avian breeding habitat, but the underlying assumptions of these metrics rarely have...
The secret to successful solute-transport modeling
Leonard F. Konikow
2011, Ground Water (49) 144-159
Modeling subsurface solute transport is difficult—more so than modeling heads and flows. The classical governing equation does not always adequately represent what we see at the field scale. In such cases, commonly used numerical models are solving the wrong equation. Also, the transport equation is hyperbolic where advection is dominant,...
Eruptive history of South Sister, Oregon Cascades
J. Fierstein, W. Hildreth, A.T. Calvert
2011, Journal of Volcanology and Geothermal Research (207) 145-179
South Sister is southernmost and highest of the Three Sisters, three geologically dissimilar stratovolcanoes that together form a spectacular 20km reach along the Cascade crest in Oregon. North Sister is a monotonously mafic edifice as old as middle Pleistocene, Middle Sister a basalt-andesite-dacite cone built between 48 and 14ka, and...
SPECTRAL data-based estimation of soil heat flux
Ramesh K. Singh, A. Irmak, Elizabeth Walter-Shea, S.B. Verma, A.E. Suyker
2011, Transactions of the ASABE (54) 1589-1597
Numerous existing spectral-based soil heat flux (G) models have shown wide variation in performance for maize and soybean cropping systems in Nebraska, indicating the need for localized calibration and model development. The objectives of this article are to develop a semi-empirical model to estimate G from a normalized difference vegetation...
Observations of changes in waveform character induced by the 1999 Mw7.6 Chi-Chi earthquake
K.H. Chen, T. Furumura, J. Rubinstein, R.-J. Rau
2011, Geophysical Research Letters (38)
We observe changes in the waveforms of repeating earthquakes in eastern Taiwan following the 1999 Mw7.6 Chi-Chi earthquake, while their recurrence intervals appear to be unaffected. There is a clear reduction in waveform similarity and velocity changes indicated by delayed phases at the time of the Chi-Chi event. These changes...
Widespread seismicity excitation throughout central Japan following the 2011 M=9.0 Tohoku earthquake and its interpretation by Coulomb stress transfer
S. Toda, R.S. Stein, J. Lin
2011, Geophysical Research Letters (38)
We report on a broad and unprecedented increase in seismicity rate following the M=9.0 Tohoku mainshock for M ≥ 2 earthquakes over inland Japan, parts of the Japan Sea and Izu islands, at distances of up to 425 km from the locus of high (≥15 m) seismic slip on the...
Characterizing land surface change and levee stability in the Sacramento-San Joaquin Delta using UAVSAR radar imagery
C. Jones, G. Bawden, S. Deverel, J. Dudas, S. Hensley
2011, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
The islands of the Sacramento-San Joaquin Delta have been subject to subsidence since they were first reclaimed from the estuary marshlands starting over 100 years ago, with most of the land currently lying below mean sea level. This area, which is the primary water resource of the state of California,...
Impacts of changing food webs in Lake Ontario: Implications of dietary fatty acids on growth of alewives
R.J. Snyder, C.J. Demarche, D. C. Honeyfield
2011, Aquatic Ecosystem Health & Management (14) 231-238
Declines in the abundance and condition of Great Lakes Alewives have been reported periodically during the last two decades, and the reasons for these declines remain unclear. To better understand how food web changes may influence Alewife growth and Wisconsin growth model predictions, we fed Alewives isocaloric diets high in...
Unravelling long-term vegetation change patterns in a binational watershed using multitemporal land cover data and historical photography
M.L. Villarreal, Laura M. Norman, Robert Webb, Diane E. Boyer, R.E. Turner
2011, Conference Paper, 2011 6th International Workshop on the Analysis of Multi-Temporal Remote Sensing Images, Multi-Temp 2011 - Proceedings
A significant amount of research conducted in the Sonoran Desert of North America has documented, both anecdotally and empirically, major vegetation changes over the past century due to human land use activities. However, many studies lack coincidental landscape-scale data characterizing the spatial and temporal manifestation of these changes. Vegetation changes...
Characterizing fragmentation of the collective forests in southern China from multitemporal Landsat imagery: A case study from Kecheng district of Zhejiang province
M. Li, Z. Zhu, James E. Vogelmann, D. Xu, W. Wen, A. Liu
2011, Applied Geography (31) 1026-1035
Tropical and subtropical forests provide important ecosystem goods and services including carbon sequestration and biodiversity conservation. These forests are facing increasing socioeconomic pressures and are rapidly being degraded and fragmented. This analysis focuses on the rate of change and patterns of fragmentation in a collective forest area in Zhejiang province,...
Structure of the San Fernando Valley region, California: implications for seismic hazard and tectonic history
V.E. Langenheim, T. L. Wright, D. A. Okaya, R.S. Yeats, G. S. Fuis, K. Thygesen, H. Thybo
2011, Geosphere (7) 528-572
Industry seismic reflection data, oil test well data, interpretation of gravity and magnetic data, and seismic refraction deep-crustal profiles provide new perspectives on the subsurface geology of San Fernando Valley, home of two of the most recent damaging earthquakes in southern California. Seismic reflection data provide depths to Miocene–Quaternary horizons;...
Terrestrial source to deep-sea sink sediment budgets at high and low sea levels: Insights from tectonically active Southern California
J.A. Covault, B.W. Romans, S.A. Graham, A. Fildani, G.E. Hilley
2011, Geology (39) 619-622
Sediment routing from terrestrial source areas to the deep sea influences landscapes and seascapes and supply and filling of sedimentary basins. However, a comprehensive assessment of land-to-deep-sea sediment budgets over millennia with significant climate change is lacking. We provide source to sink sediment budgets using cosmogenic radionuclide–derived terrestrial denudation rates...
Raman spectroscopic measurements of CO2 density: Experimental calibration with high-pressure optical cell (HPOC) and fused silica capillary capsule (FSCC) with application to fluid inclusion observations
X. Wang, I-Ming Chou, W. Hu, Robert Burruss, Q. Sun, Y. Song
2011, Geochimica et Cosmochimica Acta (75) 4080-4093
Raman spectroscopy is a powerful method for the determination of CO2 densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO2 Fermi diad split (Δ, cm−1) and CO2 density (ρ, g/cm3) has been documented by several previous studies. However, significant discrepancies exist among these...
Sibship reconstruction for inferring mating systems, dispersal and effective population size in headwater brook trout (Salvelinus fontinalis) populations
Yoichiro Kanno, Jason C. Vokoun, Benjamin H. Letcher
2011, Conservation Genetics (12) 619-628
Brook trout Salvelinus fontinalis populations have declined in much of the native range in eastern North America and populations are typically relegated to small headwater streams in Connecticut, USA. We used sibship reconstruction to infer mating systems, dispersal and effective population size of resident (non-anadromous) brook trout in two...
What is the role of fresh groundwater and recirculated seawater in conveying nutrients to the coastal ocean?
Yishai Weinstein, Yoseph Yechieli, Yehuda Shalem, William C. Burnett, Peter W. Swarzenski, Barak Herut
2011, Environmental Science and Technology (45) 5195-5200
Submarine groundwater discharge (SGD) is a major process operating at the land-sea interface. Quantifying the SGD nutrient loads and the marine/terrestrial controls of this transport is of high importance, especially in oligotrophic seas such as the eastern Mediterranean. The fluxes of nutrients in groundwater discharging from the seafloor at Dor...
Spawning habitat selection of hickory shad
Julianne E. Harris, Joseph E. Hightower
2011, North American Journal of Fisheries Management (31) 495-505
We examined the spawning habitat selectivity of hickory shad Alosa mediocris, an anadromous species on the Atlantic coast of North America. Using plankton tows and artificial substrates (spawning pads), we collected hickory shad eggs in the Roanoke River, North Carolina, to identify spawning timing, temperature, and microhabitat use. Hickory shad eggs...
