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Sample records for grande embayment texas

  1. Creationism in the Grand Canyon, Texas Textbooks

    NASA Astrophysics Data System (ADS)

    Folger, Peter

    2004-01-01

    AGU President Bob Dickinson, together with presidents of six other scientific societies, have written to Joseph Alston, Superintendent of Grand Canyon National Park, pointing out that a creationist book, The Grand Canyon: A Different View, is being sold in bookstores within the borders of the park as a scientific explanation about Grand Canyon geologic history. President Dickinson's 16 December letter urges that Alston clearly separate The Grand Canyon: A Different View from books and materials that discuss the legitimate scientific understanding of the origin of the Grand Canyon. The letter warns the Park Service against giving the impression that it approves of the anti-science movement known as young-Earth creationism, or that it endorses the advancement of religious tenets disguised as science. The text of the letter is on AGU's Web site http://www.agu.org/sci_soc/policy/sci_pol.html. Also, this fall, AGU sent an alert to Texas members about efforts by intelligent design creationists aimed at weakening the teaching of biological evolution in textbooks used in Texas schools. The alert pointed scientists to a letter, drafted by AGU, together with the American Institute of Physics, the American Physical Society, the Optical Society of America, and the American Astronomical Society, that urged the Texas State Board of Education to adopt textbooks that presented only accepted, peer-reviewed science and pedagogical expertise. Over 550 scientists in Texas added their names to the letter (http://www.agu.org/sci_soc/policy/texas_textbooks.pdf ), sent to the Board of Education on 1 November prior to their vote to adopt a slate of new science textbooks. The Board voted 11-5 in favor of keeping the textbooks free of changes advocated by groups supporting intelligent design creationism.

  2. Slip re-orientation in the oblique Abiquiu embayment, northern Rio Grande rift

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Murphy, M. A.; Andrea, R. A.

    2015-12-01

    Traditional models of oblique rifting predict that an oblique fault accommodates both dip-slip and strike-slip kinematics. However, recent analog experiments suggest that slip can be re-oriented to almost pure dip-slip on oblique faults if a preexisting weak zone is present at the onset of oblique extension. In this study, we use fault slip data from the Abiquiu embayment in northern Rio Grande rift to test the new model. The Rio Grande rift is a Cenozoic oblique rift extending from southern Colorado to New Mexico. From north to south, it comprises three major half grabens (San Luis, Española, and Albuquerque). The Abiquiu embayment is a sub-basin of the San Luis basin in northern New Mexico. Rift-border faults are generally older and oblique to the trend of the rift, whereas internal faults are younger and approximately N-S striking, i.e. orthogonal to the regional extension direction. Rift-border faults are deep-seated in the basement rocks while the internal faults only cut shallow stratigraphic sections. It has been suggested by many that inherited structures may influence the Rio Grande rifting. Particularly, Laramide structures (and possibly the Ancestral Rockies as well) that bound the Abiquiu embayment strike N- to NW. Our data show that internal faults in the Abiquiu embayment exhibit almost pure dip-slip (rake of slickenlines = 90º ± 15º), independent of their orientations with respect to the regional extension direction. On the contrary, border faults show two sets of rakes: almost pure dip-slip (rake = 90º ± 15º) where the fault is sub-parallel to the foliation, and moderately-oblique (rake = 30º ± 15º) where the fault is high angle to the foliation. We conclude that slip re-orientation occurs on most internal faults and some oblique border faults under the influence of inherited structures. Regarding those border faults on which slip is not re-oriented, we hypothesize that it may be caused by the Jemez volcanism or small-scale mantle

  3. Llano Grande Center's Oral History Project Sparks Cultural and Economic Renewal in Texas's Rio Grande Valley. Rural Trust Featured Project.

    ERIC Educational Resources Information Center

    Null, Elizabeth Higgins

    The Llano Grande Center for Research and Development started as an oral history experiment in two of Texas's poorest school districts. Since the 1920s, when this arid region in the southernmost tip of Texas was first transformed into the orchards and farmlands of the "Magic Valley," workers of Mexican descent have worked the land. Over…

  4. Short-term community transition and selection in shallow marine embayment fauna from Pennsylvanian of north-central Texas

    SciTech Connect

    Cate, A.S.

    1988-02-01

    Community and size-frequency analyses were obtained for macrofauna from a thin fossiliferous interval within an otherwise barren shallow marine embayment facies in the East Mountain Shale (Strawn Group). Vertically contiguous sampling of this discrete unit allowed reconstruction of short-term community transition and detection of shifts in the population structure of two gastropod species (Glabrocingulum G. grayvillensis, Straparollus A. catilloides). These biological phenomena could be related to environmental shifts brought about by deltaic progradation.

  5. Environmental Degradation in a Dependent Region: The Rio Grande Valley of Mexico and Texas.

    ERIC Educational Resources Information Center

    Jones, Richard C.

    1999-01-01

    Traces the interrelationships among dependence, environmental degradation, and human health in the Rio Grande Valley of Mexico and Texas. Presents a case study on environmental factors threatening family health in households located on both sides of the border; the health problems can be overcome by addressing restrictive zoning, health services,…

  6. Poverty in the Lower Rio Grande Valley of Texas: Historical and Contemporary Dimensions.

    ERIC Educational Resources Information Center

    Miller, Michael V.; Maril, Robert Lee

    Relative to other urbanized areas, the Lower Rio Grande Valley of Texas consistently ranks at the bottom in regard to almost every objective indicator of socioeconomic welfare: per capita income, educational attainment, employment, and health and housing conditions. The 1970 census discovered that approximately one-half of its population,…

  7. Poverty and Problems of Development in the Lower Rio Grande Valley of Texas.

    ERIC Educational Resources Information Center

    Miller, Michael V.

    Bounded on the west and south by Mexico and to the east by the Gulf, the Lower Rio Grande Valley of Texas is separated from the nearest U.S. urban center of any size by miles of flat and arid brushland. Its total population of approximately 335,000 is essentially composed of 2 groups--Mexican Americans and Anglos. Although the region is one of the…

  8. Evaluation of canoe surveys for anurans along the Rio Grande in Big Bend National Park, Texas

    USGS Publications Warehouse

    Jung, R.E.; Bonine, K.E.; Rosenshield, M.L.; de la Reza, A.; Raimondo, S.; Droege, S.

    2002-01-01

    Surveys for amphibians along large rivers pose monitoring and sampling problems. We used canoes at night to spotlight and listen for anurans along four stretches of the Rio Grande in Big Bend National Park, Texas, in 1998 and 1999. We explored temporal and spatial variation in amphibian counts and species richness and assessed relationships between amphibian counts and environmental variables, as well as amphibian-habitat associations along the banks of the Rio Grande. We documented seven anuran species, but Rio Grande leopard frogs (Rana berlandieri) accounted for 96% of the visual counts. Chorus surveys along the river detected similar or fewer numbers of species, but orders of magnitude fewer individuals compared to visual surveys. The number of species varied on average by 37% across monthly and nightly surveys. We found similar average coefficients of variation in counts of Rio Grande leopard frogs on monthly and nightly bases (CVs = 42-44%), suggesting that canoe surveys are a fairly precise technique for counts of this species. Numbers of Rio Grande leopard frogs observed were influenced by river gage levels and air and water temperatures, suggesting that surveys should be conducted under certain environmental conditions to maximize counts and maintain consistency. We found significant differences in species richness and bullfrog (Rana catesbeiana) counts among the four river stretches. Four rare anuran species were found along certain stretches but not others, which could represent either sampling error or unmeasured environmental or habitat differences among the river stretches. We found a greater association of Rio Grande leopard frogs with mud banks compared to rock or cliff (canyon) areas and with seepwillow and open areas compared to giant reed and other vegetation types. Canoe surveys appear to be a useful survey technique for anurans along the Rio Grande and may work for other large river systems as well.

  9. Distribution and habitat associations of juvenile Common Snook in the lower Rio Grande, Texas

    USGS Publications Warehouse

    Huber, Caleb G.; Grabowski, Timothy B.; Patino, Reynaldo; Pope, Kevin L.

    2014-01-01

    Common Snook Centropomus undecimalis were once abundant off the Texas coast, but these populations are now characterized by low abundance and erratic recruitment. Most research concerning Common Snook in North America has been conducted in Florida and very little is known about the specific biology and habitat needs of Common Snook in Texas. The primary objective of this study was to describe the habitat use patterns of juvenile Common Snook and their role in the fish assemblage in the lower portion of the Rio Grande, Texas. Secondarily, we documented the relationship between age and juvenile reproductive development. Fish were collected during January–March 2006 from the lower 51.5 km of the Rio Grande using a bottom trawl and boat-mounted electrofisher. Measurements of water quality and other habitat traits were recorded at each sampling site. We captured 225 Common Snook exclusively in freshwater habitats above river kilometer 12.9. The distribution of juvenile Common Snook was not random, but influenced primarily by turbidity and dissolved oxygen. Sex differentiation and gonadal development based on histological examination of gonads established that age-1 and age-2 Common Snook were juvenile, prepubertal males. There was no difference between the age groups in their overall distribution in the river. However, age-2 Common Snook were associated with deeper areas with faster currents, higher conductivity, and steeper banks. Overall, Common Snook in the lower Rio Grande show substantial differences in habitat use than their counterparts in other parts of the range of the species, but it is unclear whether this is due to differences in habitat availability, behavioral plasticity, or some combination thereof.

  10. Residues of toxaphene in insectivorous birds (Petrochelidon spp.) from the Rio Grande, Texas.

    PubMed

    Maruya, K A; Smalling, K L; Mora, M A

    2005-05-01

    Although it has been documented that wildlife in the Rio Grande Valley (RGV) contain increased concentrations of organochlorine (OC) contaminants, particularly DDE, little has been published on residues of toxaphene throughout this major North American watershed. In this study, 28 liver composites from adult swallows (Petrochelidon spp.) collected along the Rio Grande from 1999 through 2000 were analyzed for toxaphene residues using congener-specific gas chromatography-electron-capture negative ionization-mass spectrometry. Estimated total toxaphene concentrations ranged from 12 to 260 ng/g wet wt and were highest in samples from the lower RGV near Llano Grande Lake in Hidalgo and Cameron counties (Texas). Toxaphene congener profiles were relatively invariant throughout the watershed and were dominated by 2,2,5-endo,6-exo,8,8,9,10-octachlorobornane (P-42a or B8-806) with lesser amounts of several other Cl(7)-Cl(9) compounds, many of which remain unidentified. Petrochelidon spp. liver profiles appear to be intermediate in complexity between those in invertebrates and fish (more complex) and mammals (less complex) and differs somewhat from those reported for other avian species. In addition to other legacy OC contaminants, toxaphene residues were most concentrated in the lower RGV and accumulated at up to hundreds of parts per billion in these insect-eating birds, underscoring their utility as avian bioindicators of persistent organic pollutants.

  11. Residues of toxaphene in insectivorous birds (Petrochelidon spp.) from the Rio Grande, Texas

    USGS Publications Warehouse

    Maruya, K.A.; Smalling, K.L.; Mora, M.A.

    2005-01-01

    Although it has been documented that wildlife in the Rio Grande Valley (RGV) contain increased concentrations of organochlorine (OC) contaminants, particularly DDE, little has been published on residues of toxaphene throughout this major North American watershed. In this study, 28 liver composites from adult swallows (Petrochelidon spp.) collected along the Rio Grande from 1999 through 2000 were analyzed for toxaphene residues using congener-specific gas chromatography-electron-capture negative ionization-mass spectrometry. Estimated total toxaphene concentrations ranged from 12 to 260 ng/g wet wt and were highest in samples from the lower RGV near Llano Grande Lake in Hidalgo and Cameron counties (Texas). Toxaphene congener profiles were relatively invariant throughout the watershed and were dominated by 2,2,5-endo,6-exo,8,8,9,10- octachlorobornane (P-42a or B8-806) with lesser amounts of several other Cl 7-Cl9 compounds, many of which remain unidentified. Petrochelidon spp. liver profiles appear to be intermediate in complexity between those in invertebrates and fish (more complex) and mammals (less complex) and differs somewhat from those reported for other avian species. In addition to other legacy OC contaminants, toxaphene residues were most concentrated in the lower RGV and accumulated at up to hundreds of parts per billion in these insect-eating birds, underscoring their utility as avian bioindicators of persistent organic pollutants. ?? 2005 Springer Science+Business Media, Inc.

  12. Mexican Migrations to the U.S., 1900-1920, with a Focus on the Texas Lower Rio Grande Valley.

    ERIC Educational Resources Information Center

    Miller, Hubert J.

    Migrations from 1900-1920 were analyzed, focusing on the overall pattern of Mexican migrations to the United States during the two decades; migrations to Texas, the major recipient of migrants during the period; and migrations into the lower Rio Grande Valley. Data were based on official registrations either entering the United States or leaving…

  13. Mapping giant reed (Arundo donax) infestations along the Texas-Mexico portion of the Rio Grande using aerial photography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed is an invasive weed throughout the southern half of the United States with the densest stands growing along the coastal rivers of southern California and the Rio Grande in Texas. The objective of this study was to use aerial photography to map giant reed infestations and estimate infested...

  14. Using aerial photography for mapping giant reed infestations along the Texas-Mexico portion of the Rio Grande.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed (Arundo donax L.) is an invasive weed throughout the southern half of the United States with the densest stands growing along the coastal rivers of southern California and the Rio Grande in Texas. The objective of this study was to use aerial photography to map giant reed infestations and...

  15. 78 FR 1763 - Oranges and Grapefruit Grown in Lower Rio Grande Valley in Texas; Increased Assessment Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... From the Federal Register Online via the Government Publishing Office #0; #0;Proposed Rules #0...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 906 Oranges and Grapefruit Grown in Lower Rio Grande Valley in Texas; Increased Assessment Rate AGENCY: Agricultural Marketing Service,...

  16. Birds of the Rio Grande and other riparian habitats of Western Webb County, Texas

    USGS Publications Warehouse

    Woodin, Marc C.; Skoruppa, Mary Kay; Blacklock, Gene W.; Hickman, Graham C.

    2007-01-01

    We conducted 164 diurnal morning point counts in 1997 and 89 nocturnal point counts in 1998 along the Rio Grande and at other riparian habitats on remote ranchland in northwestern Webb County. We subsequently conducted 94 diurnal morning and 37 nocturnal point counts in 1999 on public lands along the Rio Grande and at other riparian habitats at Laredo, Webb County. From these systematic surveys (n 384) and other irregular visits to sites during the length of the study, we detected a total of 209 bird species. Many species (97) are distributed widely over much of North America, but substantial numbers of species were also of primarily eastern (30), western (30), southwestern (26), and tropical (26) distributions. Fifty-five of the 209 species (26%) occur on >1 species priority lists in six bird conservation plans that we reviewed, but only four of these were tropical species. This suggests that tropical species, the driving force behind ecotourism-sustained economies in southern Texas, may not benefit directly from recent bird conservation plans, since their lists of priority species do not include many tropical birds. Thus, conservation projects designed to benefit primarily tropical species will not be ranked highly for funding if evaluated on the basis of the bird conservation plans we reviewed.

  17. Trace elements and organic compounds associated with riverbed sediments in the Rio Grande/Rio Bravo basin, Mexico and Texas

    USGS Publications Warehouse

    Lee, R.W.; Wilson, J.T.

    1997-01-01

    In 1991, the Texas Natural Resource Conservation Commission (TNRCC) was mandated by the Texas Clean Rivers Act (Senate Bill 818) to assess water quality of rivers in Texas. Recent efforts to collect information for the assessment of water quality in the Rio Grande/Rio Bravo Basin have involved Federal agencies on both sides of the 1,248-mile U.S.-Mexico border?U.S. Environmental Protection Agency, U.S. Geological Survey (USGS), Secretaria de Desarollo Social (Secretary for Social Development, Mexico), National Water Commission of Mexico, and International Boundary and Water Commission?as well as State and local agencies in a spirit of international cooperation. Substantial efforts have been made to gather data needed to determine the quality of water and ecological status of the Rio Grande/Rio Bravo, especially at sites along the border (fig. 1). The purpose of this report is to assess selected historical data of trace elements and organic compounds in riverbed sediments of the Rio Grande/Rio Bravo, and of the Pecos River and the Arroyo Colorado in Texas.

  18. Solute Sources and Budget for the Rio Grande above El Paso, Texas

    NASA Astrophysics Data System (ADS)

    Hogan, J. F.; Phillips, F. M.; Hendrickx, J. M.

    2001-12-01

    Issues of water quality, especially salinity, limit the use of water resources from the Rio Grande. Identification and quantification of salinity sources is critical for improved river management. In the headwater region salts are typically derived from atmospheric deposition and chemical weathering reactions. Salinity increases during transit may result from both natural (saline groundwater, hydrothermal springs and dissolution of evaporite deposits) and anthropogenic (agricultural return flow and wastewater from sewage treatment plants) sources. These increases are magnified by evapotranspiration (this includes evaporation from open water, transpiration from irrigated agriculture and transpiration from natural riparian areas). With multiple salinity sources and evapotranspiration acting simultaneously, understanding the solute balance for the Rio Grande at a level needed for improved river management is difficult. We have conducted synoptic sampling of the Rio Grande from the headwaters in Colorado to south of El Paso, Texas. Sampling was conducted in January and August of 2000 and 2001. The total dissolved solids content (TDS) of the Rio Grande increases from < 50 mg/L in headwater regions of Colorado to > 2000 mg/L south of El Paso, Texas. The Cl/Br (wt/wt) ratio for river water increases from ~50 in the headwaters (typical for atmospheric deposition) to ~700 in the lower basin. This increase in Cl/Br ratio demonstrates the importance of additional salinity sources. Three end-members are recognized using Cl/Br mixing plots for winter samples: atmospheric deposition, a hydrothermal end-member localized around Truth of Consequences, NM, and a third end-member that may represent groundwater. Samples collected during the summer months are shifted off the winter mixing lines indicating concentration through ET. Increases in salinity were not a simple function of distance downriver, but rather occurred in a series of steps. Some of these steps are correlated with

  19. Assessment of organochlorine pesticide levels in Manadas Creek, an urban tributary of the Rio Grande in Laredo, Texas.

    PubMed

    Flores, Brianna; Camarena, Celina; Ren, Jianhong; Krishnamurthy, Sushma; Belzer, Wayne

    2009-07-01

    The Rio Grande is the natural boundary between the United States and Mexico from El Paso, Texas, to Brownsville, Texas. It supports about 12 million people on both sides of the border for municipal, agricultural, industrial, and recreational uses. The rapid population and economic growth along the border region has led to increased pollution in the Rio Grande, which has been linked to several border health issues associated with pesticide contamination. This project was initiated to assess the organochlorine pesticide levels in the water and sediments in Manadas Creek, an urban tributary of the Rio Grande located in north Laredo, Texas. Water and sediment samples were collected monthly during a 6-month period from July to December of 2006 and analyzed using gas chromatography with an electron capture detector after extraction via a solid-phase microextraction technique. Among the water and sediment samples collected, several organochlorine pesticides including alpha-, beta-, and gamma-hexachlorocyclohexane (HCH), heptachlor epoxide, endrin, and 4,4'-DDT were found in either the creek water or sediments. Analysis of variance results indicated that only gamma-HCH had significant variation in the creek water among the sampling periods. Comparison of results with previous findings showed the presence of higher levels of HCH isomers and much lower DDT concentrations in the present study.

  20. Species richness, relative abundance, and habitat associations of nocturnal birds along the rio grande in Southern texas

    USGS Publications Warehouse

    Skoruppa, M.K.; Woodin, M.C.; Blacklock, G.

    2009-01-01

    The segment of the Rio Grande between International Falcon Reservoir and Del Rio, Texas (distance ca. 350 km), remains largely unexplored ornithologically. We surveyed nocturnal birds monthly during February-June 1998 at 19 stations along the Rio Grande (n = 6) and at upland stock ponds (n = 13) in Webb County, Texas. We conducted 10-min point counts (n = 89) after sunset and before moonset. Four species of owls and five species of nightjars were detected. Nightjars, as a group, were nearly five limes more abundant (mean number/count = 2.63) than owls (mean number = 0.55). The most, common owl, the great horned owl (Bubo virginianus), had a mean number of 0.25/point count. The mean for elf owls (Micrathene whitneyi) was 0.16/point count. The most common nightjars were the common poorwill (Phalaenoptilus nuttallii; 1.21/point count) and lesser nighthawk (Chordeiles acutipennir, 1.16/point count). Survey sites on the river supported more species (mean = 2.2) than did upland stock ponds (mean = 1.4). However, only one species (common pauraque, Nyctidromus albicollis) showed a preference for the river sites. Our results establish this segment of the Rio Grande in southern Texas as an area of high diversity of nightjars in the United States, matched (in numbers of species) only by southeastern Arizona and southwestern New Mexico.

  1. Exposure to insecticides of brushland wildlife within the Lower Rio Grande Valley, Texas, USA

    USGS Publications Warehouse

    Custer, T.W.; Mitchell, C.A.

    1987-01-01

    Brushland wildlife within the Lower Rio Grande Valley of south Texas were studied following applications of eleven insecticides to nearby sugarcane or cotton fields. During the study no wildlife were found dead. Mean brain acetylcholinesterase (AChE) activity of great-tailed grackles (Quiscalus mexicanus) and mourning doves (Zenaida macroura) was significantly lower than controls following application of some organophosphorous insecticides. Brain AChE activity varied significantly among chemicals, days after exposure and application rates. Mean brain AChE activity of white-winged doves (Zenaida asiatica) and three small mammal species was not significantly different than their respective controls following application of insecticides. Mean brain AChE activity of grackles was inhibited significantly more than white-winged doves after application of Bolstar, EPN-methyl parathion, and Azodrin and significantly more than that of mourning doves after applications of Bolstar and EPN-methyl parathion. Our data indicate that there were no adverse effects on most brushland wildlife. Exposure was probably dependent upon use of the agricultural fields as feeding or resting sites and only grackles and mourning doves were regularly present in the fields.

  2. Exposure to insecticides of brushland wildlife within the lower Rio Grande valley Texas USA

    USGS Publications Warehouse

    Custer, T.W.; Mitchell, C.A.

    1987-01-01

    Brushland wildlife within the Lower Rio Grande Valley of south Texas were studied following applications of eleven insecticides to nearby sugarcane or cotton fields. During the study no wildlife were found dead. Mean brain acetycholinesterase (AChE) activity of great-tailed grackles (Quiscalus mexicanus) and mourning doves (Zenaida microura) was significantly lower than controls following application of some organophosphorus insecticides. Brain AChE activity varied significantly among chemicals, days after exposure and lactin rates. Mean brain AChE activity of white-winged doves (Zenaida asiatica) and three small mammals species was not significantly different than their respective control following application of the insecticides. Mean brain AChE activity of grackles was inhibited significantly more than white-winged doves after application of Bolstar, EPN-methyl parathion, and Azodrin and significantly more than that of mourning doves after applications of Bolstar and EPN-methyl parathion. Our data indicate that there were no adverse effects on most brushland wildlife. Exposure was probably dependent upon use of the agricultural fields as feeding or resting site and only grackles and mourning doves were regularly present in the fields.

  3. Anticholinesterase exposure of white-winged doves breeding in lower Rio Grande valley, Texas

    USGS Publications Warehouse

    Tacha, T.C.; Schacht, S.J.; George, R.R.; Hill, E.F.

    1994-01-01

    We studied exposure of breeding white-winged doves (Zenaida asiatica) to anticholinesterase compounds (organophosphorus and carbamate pesticides) in the Lower Rio Grande Valley (LRGV), Texas. Widespread use of organophosphorus pesticides and dove population declines prompted the study. We collected breeding adult doves in May and July 1991 (n = 28) and July 1992 (n = 33) at 6 locations. We used depression of whole-brain cholinesterase (ChE) activity (2 SD below control mean) to detect exposure; values from 4 hand-reared doves fed commercial pigeon chow served as the control. Mean brain ChE activity was lower (P lt 0.027) than the control sample at all 6 locations in 1991; 79% of the birds were diagnostic of exposure ( gt 16.1% ChE depression). Pooled 1992 field samples also were lower (P lt 0.036) than were control samples; doves from 4 of the 6 locations had brain ChE activity below (P lt 0.088) controls. Overall, 39% of 1992 doves were diagnostic of exposure to anticholinesterase compounds. Higher exposure rates in 1991 were probably due to increased use of organophosphorus pesticides. Research is needed documenting effects of sublethal exposure on white-winged dove productivity.

  4. Seepage investigation on the Rio Grande from below Caballo Reservoir, New Mexico, to El Paso, Texas, 2012

    USGS Publications Warehouse

    Gunn, Mark A.; Roark, D. Michael

    2014-01-01

    A seepage investigation was conducted by the U.S. Geological Survey, in cooperation with the New Mexico Interstate Stream Commission, along an approximately 106-mile reach of the Rio Grande from below Caballo Reservoir, New Mexico, to El Paso, Texas, during June 26–28, 2012, to determine gain or loss of streamflow due to seepage to or from the river channel. Discharge measurements were made during the irrigation season at high flow including 5 sites along the Rio Grande, 5 diversions, and 63 inflows. The net gain or loss of flow in the river channel was computed for four reaches within the 106-mile reach of the Rio Grande. The normalized percentage difference was computed for each reach to determine the difference between discharge measured at upstream and downstream sites, and the normalized percentage uncertainty was computed to determine if a computed gain or loss exceeded cumulative uncertainty associated with measurement of discharge.

  5. Creating a standardized watersheds database for the Lower Rio Grande/Río Bravo, Texas

    USGS Publications Warehouse

    Brown, J.R.; Ulery, Randy L.; Parcher, Jean W.

    2000-01-01

    This report describes the creation of a large-scale watershed database for the lower Rio Grande/Río Bravo Basin in Texas. The watershed database includes watersheds delineated to all 1:24,000-scale mapped stream confluences and other hydrologically significant points, selected watershed characteristics, and hydrologic derivative datasets.Computer technology allows generation of preliminary watershed boundaries in a fraction of the time needed for manual methods. This automated process reduces development time and results in quality improvements in watershed boundaries and characteristics. These data can then be compiled in a permanent database, eliminating the time-consuming step of data creation at the beginning of a project and providing a stable base dataset that can give users greater confidence when further subdividing watersheds.A standardized dataset of watershed characteristics is a valuable contribution to the understanding and management of natural resources. Vertical integration of the input datasets used to automatically generate watershed boundaries is crucial to the success of such an effort. The optimum situation would be to use the digital orthophoto quadrangles as the source of all the input datasets. While the hydrographic data from the digital line graphs can be revised to match the digital orthophoto quadrangles, hypsography data cannot be revised to match the digital orthophoto quadrangles. Revised hydrography from the digital orthophoto quadrangle should be used to create an updated digital elevation model that incorporates the stream channels as revised from the digital orthophoto quadrangle. Computer-generated, standardized watersheds that are vertically integrated with existing digital line graph hydrographic data will continue to be difficult to create until revisions can be made to existing source datasets. Until such time, manual editing will be necessary to make adjustments for man-made features and changes in the natural landscape

  6. Creating a standardized watersheds database for the lower Rio Grande/Rio Bravo, Texas

    USGS Publications Warehouse

    Brown, Julie R.; Ulery, Randy L.; Parcher, Jean W.

    2000-01-01

    This report describes the creation of a large-scale watershed database for the lower Rio Grande/Rio Bravo Basin in Texas. The watershed database includes watersheds delineated to all 1:24,000-scale mapped stream confluences and other hydrologically significant points, selected watershed characteristics, and hydrologic derivative datasets. Computer technology allows generation of preliminary watershed boundaries in a fraction of the time needed for manual methods. This automated process reduces development time and results in quality improvements in watershed boundaries and characteristics. These data can then be compiled in a permanent database, eliminating the time-consuming step of data creation at the beginning of a project and providing a stable base dataset that can give users greater confidence when further subdividing watersheds. A standardized dataset of watershed characteristics is a valuable contribution to the understanding and management of natural resources. Vertical integration of the input datasets used to automatically generate watershed boundaries is crucial to the success of such an effort. The optimum situation would be to use the digital orthophoto quadrangles as the source of all the input datasets. While the hydrographic data from the digital line graphs can be revised to match the digital orthophoto quadrangles, hypsography data cannot be revised to match the digital orthophoto quadrangles. Revised hydrography from the digital orthophoto quadrangle should be used to create an updated digital elevation model that incorporates the stream channels as revised from the digital orthophoto quadrangle. Computer-generated, standardized watersheds that are vertically integrated with existing digital line graph hydrographic data will continue to be difficult to create until revisions can be made to existing source datasets. Until such time, manual editing will be necessary to make adjustments for man-made features and changes in the natural landscape

  7. Hematozoan parasites of Rio Grande wild turkeys from southern Texas (USA)

    USGS Publications Warehouse

    Castle, Marc D.; Christensen, Beth A.; Rocke, Tonie E.

    1988-01-01

    One hundred twenty-three of 300 blood samples (41%) taken from Rio Grande wild turkeys (Meleagris gallopavo intermedia) from three locations in southern Texas (Welder Wildlife Refuge, Chaparrosa Ranch, and Campo Alegre Ranch) and subinoculated into domestic broad-breasted white turkey poults were positive for a Plasmodium (Novyella) sp. Analysis of blood films from 350 turkeys revealed Haemoproteus meleagridis in 76% of the birds. A significantly greater mean parasite intensity was observed in birds from Welder Wildlife Refuge. Birds from the Campo Alegre Ranch exhibited a significantly higher prevalence of H. meleagridis than birds from Chaparrosa. The Plasmodium sp. was infective for canaries (Serinus canaria), bobwhites (Colinus virginianus), and ring-necked pheasants (Phasianus colchicus), but would not produce infection in white leghorn chickens (Gallus gallus) or Coturnix quail (Coturnix coturnix). Attempts to infect Culex tarsalis and C. pipiens pipiens were unsuccessful. Asexual erythrocytic synchrony was not observed when blood-induced infections were monitored in two domestic turkey poults every 4 hr for 72 hr. Exoerythrocytic stages were not found upon examination of impression smears and tissue samples taken from brain, liver, spleen, kidney, lung, and bone marrow. The Plasmodium sp. is most similar morphologically to three species in the subgenus Novyella, P. hexamerium, P. vaughani, and P. kempi. The most striking similarities are to P. hexamerium, and involve mean merozoite number, erythrocytic schizont location, and vertebrate host susceptibility. It differs from P. vaughani in being able to infect turkeys and in type of parasitized erythrocytes. Differences to P. kempi include mean merozoite number, and ability to infect pheasants, and its inability to develop inC. pipiens and C. tarsalis.

  8. Discovery of a second population of white-collared seedeaters, Sporophila torqueola (Passeriformes: emberizidae) along the Rio Grande of Texas

    USGS Publications Warehouse

    Woodin, Marc C.; Skoruppa, Mary K.; Blacklock, Gene W.; Hickman, Graham C.

    1999-01-01

    The range of the white-collared seedeater (Sporophila torqueola), a tropical grassland species, extends from Central America northward along both coasts of Mexico (Eitniear, 1997), including Tamaulipas and Nuevo Leon (Howell and Webb, 1995). White-collared seedeaters historically occurred commonly in extreme southern Texas (Oberholser, 1974; Rappole and Blacklock, 1994). However, since about 1950, white-collared seedeaters have undergone a precipitous decline in south Texas. Studies during 1994-1996 identified only seven to nine breeding pairs in the only population known to occur in Texas, located ca. 55 km downriver of Laredo, Texas, in Zapata Co. (Eitniear, 1997). Outside of the historical range, very few records are documented. Oberholser (1974) reported that three white-collared seed- eater specimens were collected in 1948 in Webb Co., northwest of Laredo, and Arnold (1980) also collected a white-collared seedeater in Webb Co. Vagrants also have been sighted as far afield as Corpus Christi (Blacklock, 1964), ca. 200 km north of the Rio Grande (Fig. 1).

  9. Quality of Shallow Groundwater and Drinking Water in the Mississippi Embayment-Texas Coastal Uplands Aquifer System and the Mississippi River Valley Alluvial Aquifer, South-Central United States, 1994-2004

    USGS Publications Warehouse

    Welch, Heather L.; Kingsbury, James A.; Tollett, Roland W.; Seanor, Ronald C.

    2009-01-01

    The Mississippi embayment-Texas coastal uplands aquifer system is an important source of drinking water, providing about 724 million gallons per day to about 8.9 million people in Texas, Louisiana, Mississippi, Arkansas, Missouri, Tennessee, Kentucky, Illinois, and Alabama. The Mississippi River Valley alluvial aquifer ranks third in the Nation for total withdrawals of which more than 98 percent is used for irrigation. From 1994 through 2004, water-quality samples were collected from 169 domestic, monitoring, irrigation, and public-supply wells in the Mississippi embayment-Texas coastal uplands aquifer system and the Mississippi River Valley alluvial aquifer in various land-use settings and of varying well capacities as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Groundwater samples were analyzed for physical properties and about 200 water-quality constituents, including total dissolved solids, major inorganic ions, trace elements, radon, nutrients, dissolved organic carbon, pesticides, pesticide degradates, and volatile organic compounds. The occurrence of nutrients and pesticides differed among four groups of the 114 shallow wells (less than or equal to 200 feet deep) in the study area. Tritium concentrations in samples from the Holocene alluvium, Pleistocene valley trains, and shallow Tertiary wells indicated a smaller component of recent groundwater than samples from the Pleistocene terrace deposits. Although the amount of agricultural land overlying the Mississippi River Valley alluvial aquifer was considerably greater than areas overlying parts of the shallow Tertiary and Pleistocene terrace deposits wells, nitrate was rarely detected and the number of pesticides detected was lower than other shallow wells. Nearly all samples from the Holocene alluvium and Pleistocene valley trains were anoxic, and the reducing conditions in these aquifers likely result in denitrification of nitrate. In contrast, most samples from the

  10. Hydrogeological characterization of a bank filtration experiment site at the Rio Grande, El Paso, Texas, USA

    NASA Astrophysics Data System (ADS)

    Langford, R.; Schulze-Makuch, D.; Pillai, S.; Abdel-Fattah, A.; Widmer, K.

    2003-04-01

    An experiment site was constructed along an artificial channel of the Rio Grande in El Paso, Texas. The experiment was funded by the EPA and is designed to measure the effectiveness of bank filtration in an arid environment. Regionally, the experiment is important because of the hundreds of thousands of people drinking water from shallow wells drilled in close proximity to septic systems. A pumping well was drilled 17 meters from the stream bank and screened from 3.5 to 8 m depth. A cruciform array of observation wells with several multilevel completions allows detection of downstream and vertical movement of water as well as flow from the stream to the well. All of the wells were continuously cored during drilling. Analysis of the cores reveals that the site consists of two stacked channels filled with sand deposited from the meandering Rio Grande. A grid of ground-penetrating radar lines provided three-dimensional coverage between wells and showed bedding to 6.5 m depth. Constant head hydraulic conductivities show that the aquifer consists of two more permeable units separated by the less permeable upper fill of the lower channel complex, with vertical hydraulic conductivities of (1x10-6 to 2x10-6 m/s?). The intervals above and below this interval have the highest vertical conductivities (up to 3.5x10-5 m/s). A multiple pumping and tracer test was conducted using the cruciform array of the field site that consisted of a pumping well, 16 observation wells, and a stream sampling point. The average hydraulic conductivity of the geological media at the field site was about 2 x 10-3 m/s based on pumping test analysis. However, the type curve responses revealed significant heterogeneity of hydraulic conductivity throughout the field site. For the tracer test, bromide and microspheres were used as tracers. Microspheres were used to mimic the behavior of Giardia and Cryptosporidium. The tracers (bromide and microspheres of different sizes and colors) were injected in one

  11. Texas

    USGS Publications Warehouse

    ,

    1999-01-01

    In 1997, the Texas Legislature passed a comprehensive revision to the Texas Water Code. This legislation (Senate Bill 1) changed water planning in Texas from a statewide to a regional activity. By September 2001, the 16 regions created by Senate Bill 1 must produce water plans to address their water needs during drought-of-record conditions, and must identify water-management strategies for periods when streamflows, reservoir storage, and groundwater levels are 50 and 75 percent of normal.

  12. Biomarkers of exposure and effects of environmental contaminants on swallows nesting along the Rio Grande, Texas, USA

    USGS Publications Warehouse

    Mora, M.A.; Musquiz, D.; Bickham, J.W.; MacKenzie, D.S.; Hooper, M.J.; Szabo, J.K.; Matson, C.W.

    2006-01-01

    We collected adult cave swallows (Petrochelidon fulva) and cliff swallows (P. pyrrhonota) during the breeding seasons in 1999 and 2000 from eight locations along the Rio Grande from Brownsville to El Paso (unless otherwise specified, all locations are Texas, USA) and an out-of-basin reference location. Body mass, spleen mass, hepatosomatic index (HSI), gonadosomatic index (GSI), thyroxine (T4) in plasma, DNA damage measured as the half-peak coefficient of variation of DNA content (HPCV) in blood cells, as well as acetylcholinesterase and butyrylcholinesterase in brain were compared with concentrations of organochlorines, metals, and metalloids in carcasses to determine potential effects of contaminants on swallows during the breeding season. Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p???-DDE) were significantly greater in swallows from El Paso than in those from most locations, except for Pharr and Llano Grande. All swallows from these three locations had p,p???-DDE concentrations of 3 ??g/g wet weight or greater. Swallows from El Paso either had or shared the highest concentrations of p,p???-DDE, polychlorinated biphenyls, and 13 inorganic elements. Swallows from El Paso exhibited greater spleen mass and HPCV values as well as lower T4 values compared with those from other locations. Thyroxine was a potential biomarker of contaminant exposure in swallows of the Rio Grande, because it was negatively correlated with p,p???-DDE and Se. Spleen mass was positively correlated with selenium and HSI and negatively correlated with body mass, GSI, Mn, and Ni. Overall, the present study suggests that insectivorous birds living in areas of high agricultural and industrial activity along the Rio Grande bioaccumulate environmental contaminants. These contaminants, particularly p,p???-DDE, may be among multiple factors that impact endocrine and hematopoietic function in Rio Grande swallows. ?? 2006 SETAC.

  13. Novel techniques developed to control cattle fever ticks feeding on free-ranging white-tailed deer along the Rio Grande in South Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle fever ticks were eradicated from the southern and southeastern U.S. and California in a campaign that lasted from 1907 through 1943, however, re-introductions across the Rio Grande from Mexico and into South Texas have resulted in extensive efforts to maintain eradication from other parts of ...

  14. Spatial information technologies for climate change impact on ecosystems: detecting and mapping invasive weeds in the Rio Grande River system of south Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wetlands and aquatic ecosystems are vulnerable to climate change. Exotic invasive weeds are a serious problem in the Rio Grande River system of Texas. The river extends 3,040 km from its source in the San Juan Mountains of Colorado to the mouth at the Gulf of Mexico on the United States-Mexico borde...

  15. Application of scintillometry to estimate water use by giant reed (Arndo Donax L.)- A perennial invasive weed along the Rio Grande River near Laredo, Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed (Arundo donax L.) is a bamboo-like perennial invasive weed from Eurasia presenting a severe threat to agroecosystems and riparian areas in Texas and Mexican portions of the Rio Grande River Basin. It is spreading rapidly by displacing native vegetation. Giant reeds are expected to consume...

  16. Colonias in the Lower Rio Grande Valley of South Texas: A Summary Report. Lyndon B. Johnson School of Public Affairs, Policy Research Report, Number 18.

    ERIC Educational Resources Information Center

    Haynes, Kingsley E.; And Others

    The Lower Rio Grande Valley of South Texas consists of three counties: Cameron, Hidalgo, and Willacy. Poverty pervades in the Valley, especially in the colonias ("a poor, rural unincorporated community with 20 or more dwelling units, where home ownership is the rule"). Colonia residents are almost exclusively Mexican Americans.…

  17. Spatial and temporal variations in streamflow, dissolved solids, nutrients, and suspended sediment in the Rio Grande Valley study unit, Colorado, New Mexico, and Texas, 1993-95

    USGS Publications Warehouse

    Moore, Stephanie J.; Anderholm, Scott K.

    2002-01-01

    Streamflow and water quality vary spatially and temporally in the Rio Grande from Del Norte, Colorado, to El Paso, Texas. The variations in streamflow and in concentrations of selected waterquality constituents?dissolved solids, dissolved nitrite plus nitrate as nitrogen, total phosphorus, and suspended sediment?are described in this report. A multivariate linear regression model, ESTIMATOR2000, was used to estimate loads for selected constituents. Streamflow decreases in the downstream direction throughout most of the basin because outflows (due to agricultural use, leakage to ground water, and evapotranspiration) are greater than inflows. Streamflow increases between Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, to Rio Grande at Otowi Bridge, near San Ildefonso, New Mexico, because ground-water and tributary inflow are greater than outflow. Concentrations of dissolved solids, dissolved nitrite plus nitrate, total phosphorus, and suspended sediment generally increase in the downstream direction. Concentrations of dissolved solids, dissolved nitrite plus nitrate, and total phosphorus decrease between Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, and Rio Grande at Otowi Bridge, near San Ildefonso, New Mexico, because of dilution by tributary inflow. Concentrations of dissolved nitrite plus nitrate, total phosphorus, and suspended sediment decrease between Rio Grande Floodway at San Marcial, New Mexico, and Rio Grande below Leasburg Dam, near Leasburg, New Mexico, because of reservoir effects (nutrient uptake and settling of sediment). Several instances of decreasing streamflow and increasing loads indicate the presence of inflows with large constituent concentrations (relative to those of the Rio Grande immediately upstream from that inflow); this occurs (1) between Rio Grande near Del Norte, Colorado, and Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, for dissolved solids, (2) between Rio

  18. Elevated DDE and toxaphene residues in fishes and birds reflect local contamination in the lower Rio Grande valley Texas USA

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Kennedy, H.R.; Krynitsky, A.J.; Ribick, M.A.

    1983-01-01

    A potential organochlorine pesticide problem was identified near Mission, Texas, by the National Park Monitoring Program. Fish samples from this site have consistently contained elevated levels of DDE since 1968. Surveys were made in 1976, 1978, and 1979 to determine the extent of organochlorine pesticide contamination in fishes and birds of the area. Freshwater fishes of Arroyo Colorado, a major waterway traversing the lower Rio Grande Valley, were highly contaminated with DDE and toxaphene residues compared to samples from other areas in the Valley; both DDE and toxaphene ranged up to 31.5 ppm wet wt in whole-fish composite samples. Median DDE residues in fish-eating bird carcasses from this area ranged up to 34 ppm wet wt, and 81 ppm in individual specimens. The levels of contaminants detected in fishes and birds were within, or above, the range producing adverse effects in certain species. The major sources of contamination to the Arroyo Colorado system likely stem from past and present use of persistent pesticides on surrounding croplands, and possibly from an abandoned pesticide plant at Mission, Texas.

  19. Elevated DDE and toxaphene residues in fishes and birds reflect local contamination in the lower Rio Grande Valley, Texas

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Kennedy, H.D.; Krynitsky, A.J.; Ribick, M.A.

    1983-01-01

    A potential organochlorine pesticide problem was identified near Mission, Texas, by the National Pesticide Monitoring Program. Fish samples from this site have consistently contained elevated levels of DDE since 1968. Surveys were made in 1976, 1978, and 1979 to determine the extent of organochlorine pesticide contamination in fishes and birds of the area. Freshwater fishes of the Arroyo Colorado, a major waterway traversing the lower Rio Grande Valley, were highly contaminated with DDE and toxaphene residues compared to samples from other areas in the Valley; both DDE and toxaphene ranged up to 31.5 ppm wet weight in whole-fish composite samples. In addition, median DDE residues in fish-eating bird carcasses from this area ranged up to 34 ppm wet weight, and 81 ppm in individual specimens. The levels of contaminants detected in fishes and birds were within, or above, the range producing adverse effects in certain species. The major sources of contamination to the Arroyo Colorado system likely stem from past and present use of persistent pesticides on surrounding croplands, and possibly from an abandoned pesticide plant at Mission, Texas.

  20. A survey of bee species found pollinating watermelons in the Lower Rio Grande Valley of Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using a combination of flower traps and visual observations, we surveyed three watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] fields in the Lower Rio Grande Valley to determine what bees inhabit this crop in this region. No managed honey bee (Apis mellifera L.) hives were in any of the fie...

  1. Chickamauga reservoir embayment study - 1990

    SciTech Connect

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.

    1992-12-01

    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  2. Floodplain construction of the Rio Grande at El Paso, Texas, USA: response to Holocene climate change

    NASA Astrophysics Data System (ADS)

    Hall, Stephen A.; Peterson, John A.

    2013-04-01

    The Rio Grande is one of the larger rivers in North America, and the development of its floodplain is related to Holocene climate and climate change. The late Pleistocene through early Holocene channel is characterized by a meander or braided system with lateral cutting and backfilling, resulting in the valley-wide deposition of massive to cross-bedded, fine-to-medium textured sand. The late Pleistocene-early Holocene floodplain is also the sand source for the adjacent Bolson sand sheet. The sand sheet stopped accumulating new sand 5000 yrs ago, an event directly related to the shutting off of the sand supply caused by the deposition of overbank muds that covered and sealed the floodplain surface. During the middle Holocene, the river may have dried intermittently with the floodplain becoming deflated and local sand dunes forming on the floodplain. After 5000 yrs the climate was less arid and the river shifted to a regime of increased flooding and overbank deposition of silt and clay. By 2500 yrs, a late Holocene period of wet climate resulted in further overbank deposition and the formation of a cumulic Mollisol across the floodplain, the Socorro paleosol. The period of wet climate corresponds to the Audubon Neoglacial and active rock glaciers in the southern Rocky Mountains, speleothem growth in nearby caves, and other evidence for wet-cool conditions in the region. After 1000 yrs, the climate became drier, and the deposition and accumulation of overbank muds by the flooding Rio Grande came to a halt. Even though the river has flooded often in historic times, and presumably during late prehistoric times as well, there is little evidence for deposition of overbank sediments on the floodplain since A.D. 1000. Accordingly, the present-day surface of the Lower Valley is ten centuries old. Three channels occur on the US side of the Lower Valley floodplain, and during the past 2500 yrs stream flow has shifted from one to the other by the avulsion process of channel

  3. Spatial distribution of antimony and arsenic levels in Manadas Creek, an urban tributary of the Rio Grande in Laredo, Texas.

    PubMed

    Baeza, Marcia; Ren, Jianhong; Krishnamurthy, Sushma; Vaughan, Thomas C

    2010-02-01

    The Rio Grande and its tributaries represent a critical water source for both the human population and the ecological resources of the Rio Grande drainage basin. Manadas Creek, an urban tributary of the Rio Grande, is located in an industrialized area of Laredo, Texas, where warehouses, a major railroad, and a decommissioned antimony (Sb) smelter are located. Previous studies have found that the creek water is contaminated with heavy metals such as Sb and arsenic (As). However, data on the metal distribution in this creek are very limited. Herein, water and sediment core samples were collected from six sites along the creek in February, April, and May 2008. Samples were analyzed for dissolved and total metals in water, total metals in sediments, and available (soluble-exchangeable, surface adsorbed, and organically bound) fractions of metals associated with the sediments. Results show that concentrations of Sb in the water and sediment samples were significantly lower at the upstream control site compared to the two sites located near the decommissioned smelter. Decreasing levels of Sb were found at the sites located downstream. The As levels in the sediment remained constant at different depths, whereas Sb varied significantly. A high level, 420 mg/kg, of sediment Sb was found at the maximum sediment depth of 35.0 cm sampled. In addition, 65.7-76.9% Sb and 80.3-85.6% As were in their residual form, 15.0-22.5% Sb and 6.2-11.4% As were bound to organic matter, and the remaining As and Sb were in the soluble and surface adsorbed fractions. Pearson correlation analyses indicated that the distribution of Sb was only moderately correlated to iron and nickel in the sediment and its correlation with the sediment properties measured was insignificant. Cluster analyses only grouped the two Sb isotopes together for the sediments collected in May, indicating that sources other than natural occurrence were associated with Sb. The high level of sediment Sb observed indicates

  4. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas; ground-water quality in the Rio Grande flood plain, Cochiti Lake, New Mexico, to El Paso, Texas, 1995

    USGS Publications Warehouse

    Bexfield, L.M.; Anderholm, S.K.

    1997-01-01

    From March to May of 1995, water samples were collected from 30 wells located in the flood plain of the Rio Grande between Cochiti Lake, New Mexico, and El Paso, Texas. These samples were analyzed for a broad host of constituents, including field parameters, major constituents, nutrients, dissolved organic carbon, trace elements, radiochemicals, pesticides, and volatile organic compounds. The main purpose of this study was to observe the quality of ground water in this part of the Rio Grande Valley study unit of the U.S. Geological Survey National Water-Quality Assessment program. The sampling effort was limited to the basin- fill aquifer beneath the above-defined reach of the Rio Grande flood plain because of the relative homogeneity of the hydrogeology, the large amount of ground-water use for public supply, and the potential for land-use activities to affect the quality of ground water. Most of the wells sampled for the study are used for domestic purposes, including drinking water. Depths to the tops of the sampling intervals in the 30 wells ranged from 10 to 345 feet below land surface, and the median was 161.5 feet; the sampling intervals in most of the wells spanned about 10 feet or less. Quality-control data were collected at three of the wells. A significant amount of variation was found in the chemical composition of ground water sampled throughout the study area, but the water generally was found to be of suitable chemical quality for use as drinking water, according to current enforceable standards established by the U.S. Environmental Protection Agency (EPA). Nutrients generally were measured at concentrations near or below their method reporting limits. The most dominant nutrient species was nitrite plus nitrate, at a maximum concentration of 1.9 milligrams per liter (as N). Only eight of the trace elements analyzed for had median concentrations greater than their respective minimum reporting levels. Water from one well exceeded the lifetime health

  5. Environmental contaminants in blood, hair, and tissues of ocelots from the Lower Rio Grande Valley, Texas, 1986-1997

    USGS Publications Warehouse

    Mora, M.A.; Laack, L.L.; Clare, Lee M.; Sericano, J.; Presley, R.; Gardinali, P.R.; Gamble, L.R.; Robertson, S.; Frank, D.

    2000-01-01

    The ocelot (Felis pardalis) is an endangered neotropical cat distributed within a small range in the Lower Rio Grande Valley (LRGV), in Texas, U.S.A. Studies of the impacts of environmental contaminants in wild cats are few. Approximately one fourth of the estimated population (about 100) of ocelots in the LRGV was sampled to evaluate the impacts of chlorinated pesticides, polychlorinated biphenyls, and trace elements on the population. Hair was collected from 32 ocelots trapped between 1986-1992, and blood was collected from 20 ocelots trapped between 1993-1997. A few blood samples were obtained from individuals recaptured two or three times. Tissue samples from 4 road-killed ocelots were also analyzed. DDE, PCBs, and Hg were some of the most common contaminants detected in hair and blood. Mean Hg levels in hair ranged from 0.5 to 1.25 ??g g-1 dw, Se from 1.5 to 3.48 ??g g-1 dw, and Pb from 0.56 to 26.8 ??g g-1 dw. Mean DDE concentrations in plasma ranged from 0.005 ??g g-1 ww to 0.153 ??g g-1 ww, and PCBs ranged from 0.006 ??g g-1 ww to 0.092 ??g g-1 ww. Mean Hg levels in red blood cells ranged from 0.056 ??g g-1 dw to 0.25 ??g g-1 dw. Concentrations of DDE, PCBs, or Hg, did not increase significantly with age, although the highest concentrations of DDE and Hg were found in older animals. Overall, concentrations of DDE, PCBs, and Hg were low and at levels that currently do not pose any threat to health or survival of the ocelot. This is further supported by good reproduction of the ocelot in the LRGV, where adult females averaged about 1.5 kittens/litter. Thus, it seems that the current major threat to recovery of the ocelot in the LRGV may be habitat loss, although potential impacts of new generation pesticides, such as organophosphorus and carbamate insecticides need further study.The ocelot (Felis pardalis) is an endangered neotropical cat distributed within a small range in the Lower Rio Grande Valley (LRGV), in Texas, U.S.A. Studies of the impacts of

  6. Regional variation and relationships between the contaminants dde and selenium and stable isotopes in swallows nesting along the Rio Grande and one reference site, Texas, USA.

    PubMed

    Mora, M A; Boutton, T w; Musquiz, D

    2005-03-01

    Cave swallows (Petrochelidon fulva) and cliff swallows (P. pyrrhonota) nest in numerous colonies throughout the Texas portion of the Rio Grande along the U.S. border with Mexico. We collected swallows during 1999 and 2000 from eight locations along the Rio Grande to determine if delta15N and delta13C values could be used to predict 1,1-di-(p-chlorophenyl-)2,2-dichloroethene (DDE) and selenium (Se) contaminant burdens in insectivorous birds nesting across a geographic gradient in the Texas-Mexico border and to discern if stable isotopes could help discriminate between local versus nonlocal acquisition of contaminants. We analysed delta15N and delta13C in liver and muscle and DDE and Se in swallow carcasses. Within individuals, delta15N was higher in liver than in muscle of both species by an average of 1.34%, whereas delta13C was 0.145% higher in muscle than in liver. Significant differences occurred among locations in delta15N and delta13C values in liver and muscle of both species. Cave swallows from three locations in the Lower Rio Grande Valley were more enriched in delta15N than swallows from other sites. In general, swallows nesting in more northern latitudes along the Rio Grande had lower delta15N and delta13C values than those nesting farther south. Concentrations of DDE were significantly greater in swallows from El Paso, Llano Grande, and Pharr than in those from Brownsville, Falcon Lake, Laredo, Del Rio, and a reference site outside the Rio Grande. All swallows (n = 21) from El Paso, Llano Grande, and Pharr had DDE concentrations > or = 3 microg g(-1) wet weight (ww), a value three times greater than the estimated threshold in avian prey that could cause potential reproductive failures in raptors. Concentrations of Se also were significantly greater in El Paso and Del Rio than at other locations. Most Se concentrations were not of concern for direct effects on birds or their predators. Principal component analysis indicated some positive correlations

  7. Chlorinated hydrocarbons and biomarkers of exposure in wading birds and fish of the Lower Rio Grande Valley, Texas

    USGS Publications Warehouse

    Wainwright, S.E.; Mora, M.A.; Sericano, J.L.; Thomas, P.

    2001-01-01

    During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and great egrets (Ardea alba) were similar to those found in other parts of North America; however, nesting success of black-crowned night-herons (Nycticorax nycticorax) was lower, very likely due to flooding of the nesting area. Except for DDE and toxaphene, all chlorinated pesticides in bird eggs were low and not of concern for negative effects on any of the three species. DDE was highest in green heron eggs and seemed to increase along a geographic gradient from west to east, with eggs from Falcon Reservoir containing low concentrations, and those at Los Indios containing the highest concentrations (approx. 11,000 ng/g WW), near or above the threshold for reproductive impairment. DDE levels in great egrets and black-crowned night-herons were below those that are associated with reproductive impairment. Mean DDE levels in carp at the JAS Farms site were above the threshold level suggested for predator protection. Toxaphene was detected in about 20% of the samples with high levels observed in green heron eggs from Los Indios (mean = 4,402 ng/g WW). These are the highest toxaphene levels reported in bird eggs in the LRGV. Toxaphene levels in fish ranged between 90 and 312 ng/g WW. In general, PCBs in bird eggs and fish tissue were low and at levels not of concern for reproductive effects. The greatest concentrations of testosterone and 11-ketotestosterone were detected in fish from the JAS Farms site, which also had the greatest concentrations of DDE. Increased androgen production and gonad development in fish at this site, relative to Pharr, could be possibly associated with

  8. Use of semipermeable membrane devices (SPMD) to assess occurrence and estimate water concentrations of selected organic compounds in the Rio Grande from Presidio to Brownsville, Texas

    USGS Publications Warehouse

    Moring, J. Bruce

    1999-01-01

    In Texas, the Rio Grande forms the international boundary between Mexico and the United States and extends about 2,000 kilometers from El Paso to the mouth of the Rio Grande just south of Brownsville, where the river flows into the Gulf of Mexico (fig. 1). The North American Free Trade Agreement (NAFTA) has resulted in increased industrialization and population growth on both sides of the international boundary, which in turn has focused attention on environmental issues, including water quality and quantity in the Rio Grande. Nonpoint urban and agricultural runoff and wastewater discharges from industrial and municipal facilities are potential sources of organic compounds such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Historical applications of organochlorine pesticides such as DOT and chlordane in the United States and Mexico have resulted in a continuing source of these environmentally longlived compounds in the Rio Grande Basin. In the United States, all organochlorine pesticides either have been banned entirely or have use restrictions. However, in Mexico, the organochlorine pesticide DOT is still in use, although with some application restrictions.

  9. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas; fish communities at selected sites, 1993-95

    USGS Publications Warehouse

    Carter, L.F.

    1997-01-01

    Fish communities at 10 sites in the Rio Grande Basin were sampled during low-flow periods between 1993 and 1995 as part of the U.S. Geological Survey National Water-Quality Assessment Program. The ecology of fish communities is one of several lines of evidence used to characterize water-quality conditions. This report describes the fish communities at selected sites in the Rio Grande Basin and relates the structure of these fish communities to the physical and chemical characteristics of the streams. Twenty-nine species of fish representing 10 families were identified in 25 samples collected during this study. Species richness ranged from 1 to 13. Cluster analysis of the 25 samples collected during this study delineated four groups of sites that were based on the similarity of the fish communities. The first two groups were individual sites with low species richness. The third group contained the most samples, and the fourth group consisted of samples from the Rio Grande at Isleta, New Mexico, and the Rio Grande at El Paso, Texas. The shift in community structure of samples from group 3 to group 4 reflects changes from predominantly coldwater fishes to warmwater fishes. Four metrics of biotic integrity (percentages of introduced individuals, omnivores, tolerant individuals, and anomalies) were used in this study to provide a broad overview of the community structure. The relative percentages of introduced species at the Rio Grande near Del Norte, Colorado; Saguache Creek near Saguache, Colorado; Rio Grande below Taos Junction Bridge, near Taos, New Mexico; and Rio Grande at Isleta are indicative of biological stress on the communities at these sites. The dominance of omnivores in samples from the Rio Grande below Taos Junction Bridge, near Taos; Rio Chama near Chamita, New Mexico; Rio Grande at Isleta; and Rio Grande at El Paso is an indication of environmental stress at these sites. In 1995, tolerant species accounted for the entire fish community at the Rio

  10. Water-quality assessment of the Rio Grande Valley study unit, Colorado, New Mexico, and Texas; analysis of selected nutrient, suspended-sediment, and pesticide data

    USGS Publications Warehouse

    Anderholm, S.K.; Radell, M.J.; Richey, S.F.

    1995-01-01

    This report contains a summary of data compiled from sources throughout the Rio Grande Valley study unit of the National Water- Quality Assessment program. Information presented includes the sources and types of water-quality data available, the utility of water-quality data for statistical analysis, and a description of recent water-quality conditions and trends and their relation to natural and human factors. Water-quality data are limited to concentrations of selected nutrient species in surface water and ground water, concentrations of suspended sediment and suspended solids in surface water, and pesticides in surface water, ground water, and biota. The Rio Grande Valley study unit includes about 45,900 square miles in Colorado, New Mexico, and Texas upstream from the streamflow-monitoring station Rio Grande at El Paso, Texas. The area also includes the San Luis Closed Basin and the surface-water closed basins east of the Continental Divide and north of the United States-Mexico international border. The Rio Grande drains about 29,300 square miles in these States; the remainder of the study unit area is in closed basins. Concentrations of all nutrients found in surface-water samples collected from the Rio Grande, with the exception of phosphorus, generally remained nearly constant from the northernmost station in the study unit to Rio Grande near Isleta, where concentrations were larger by an order of magnitude. Total nitrogen and total phosphorus loads increased downstream between Lobatos, Colorado, and Albuquerque, New Mexico. Nutrient concentrations remained elevated with slight variations until downstream from Elephant Butte Reservoir, where nutrient concentrations were lower. Nutrient concentrations then increased downstream from the reservoir, as evidenced by elevated concentrations at Rio Grande at El Paso, Texas. Suspended-sediment concentrations were similar at stations upstream from Otowi Bridge near San Ildefonso, New Mexico. The concentration and

  11. Spatial and Temporal Variations in Streamflow and Dissolved Solids in the Rio Grande from Del Norte, Colorado, to El Paso, Texas, 1993-95

    NASA Astrophysics Data System (ADS)

    Moore, S. J.; Anderholm, S. K.

    2002-12-01

    Data collected as part of the Rio Grande Valley National Water Quality Assessment Program were used to evaluate spatial and temporal variations in streamflow and the concentration of dissolved solids at selected sites on the Rio Grande from Del Norte, Colorado, to El Paso, Texas, for the period of April 1993 to September 1995. Dissolved solids loads, which were estimated by a multivariate linear regression model (ESTIMATOR2000), are also presented and discussed. Spatial and temporal variations in streamflow, dissolved solids concentrations, and dissolved solids loads were used to evaluate how surface-water and ground-water inflows to and outflows from the Rio Grande affect dissolved solids along the river. Streamflow decreases from Del Norte, Colorado, to the mouth of the Conejos River because of diversions for irrigation. Streamflow increases from the mouth of the Conejos River to Otowi Bridge because of surface-water inflows (from the Conejos River, the Chama River, and other tributaries) and ground-water inflow in northern New Mexico. Streamflow decreases downstream from Otowi Bridge because outflows (due to agricultural use, leakage to ground water, and evapo-transpiration) are greater than inflows. Dissolved solids concentrations generally increase in the downstream direction; however, dissolved solids concentrations decrease between the mouth of the Conejos River and Otowi Bridge due to surface-water inflows from the Conejos and the Chama Rivers and ground-water inflows in northern New Mexico. In several reaches of the Rio Grande, decreasing streamflow and increasing dissolved solids loads indicate the presence of inflows with large dissolved solids concentrations (relative to those of the Rio Grande immediately upstream from that inflow); this occurs (1) between Del Norte, Colorado, and the mouth of Trinchera Creek, near Lasauses, Colorado (2) between Otowi Bridge and San Marcial, New Mexico, and (3) between Leasburg, New Mexico, and El Paso, Texas

  12. Geothermal gradients in Mississippi embayment

    SciTech Connect

    Staub, W.P.; Treat, N.L.

    1983-09-01

    A statistical analysis of bottom-hole temperatures from oil and gas wells in the northern Mississippi embayment suggests that the geothermal gradient below a depth of 1 km is low (22.2/sup 0/C/km) and for the New Madrid seismic zone, it is even lower (15.7/sup 0/C/km). These data support the tentative conclusion of Swanberg et al that ground-water convection is the source of near-surface heat in shallow water wells of the region. Research by Mitchell et al had suggested a high geothermal gradient in the crust and upper mantel beneath the New Madrid seismic zone as a plausible explanation for the lower than average compressional wave velocities observed there. Warmer than normal wells in the northern Mississippi embayment are scattered at random and may be attributed to random error in the data. Deep wells in the southern Mississippi embayment are substantially hotter than wells at a comparable depth farther north. The regional geothermal gradient below a depth of 1 km from northern Louisiana to central Mississippi is 26.9/sup 0/C/km. From central Mississippi to central Alabama, the geothermal gradient (23.1/sup 0/C/km) is comparable to that of the northern Mississippi embayment.

  13. Web application to access U.S. Army Corps of Engineers Civil Works and Restoration Projects information for the Rio Grande Basin, southern Colorado, New Mexico, and Texas

    USGS Publications Warehouse

    Archuleta, Christy-Ann M.; Eames, Deanna R.

    2009-01-01

    The Rio Grande Civil Works and Restoration Projects Web Application, developed by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers (USACE) Albuquerque District, is designed to provide publicly available information through the Internet about civil works and restoration projects in the Rio Grande Basin. Since 1942, USACE Albuquerque District responsibilities have included building facilities for the U.S. Army and U.S. Air Force, providing flood protection, supplying water for power and public recreation, participating in fire remediation, protecting and restoring wetlands and other natural resources, and supporting other government agencies with engineering, contracting, and project management services. In the process of conducting this vast array of engineering work, the need arose for easily tracking the locations of and providing information about projects to stakeholders and the public. This fact sheet introduces a Web application developed to enable users to visualize locations and search for information about USACE (and some other Federal, State, and local) projects in the Rio Grande Basin in southern Colorado, New Mexico, and Texas.

  14. Llano Grande Lake bottom sediments; a chronicle of water-quality changes in the Arroyo Colorado, South Texas, 1989-2001

    USGS Publications Warehouse

    Mahler, Barbara June; Van Metre, Peter C.

    2002-01-01

    The Arroyo Colorado, an ancient channel of the Rio Grande, extends 90 miles from Mission, Tex., to the Laguna Madre. The Arroyo Colorado flows through areas of intense agricultural cultivation and through important habitat for migrating birds and other wildlife, including several wildlife sanctuaries and refuges. The above-tidal segment of the Arroyo Colorado is included in the State of Texas 2000 Clean Water Act 303(d)1 list in part because of elevated concentrations of the hydrophobic legacy pollutants DDE (a DDT breakdown product), chlordane, and toxaphene in fish tissue. This report addresses three questions: Do legacy pollutants (organochlorine compounds, major and trace elements) occur in the Arroyo Colorado at present and at what concentrations?How has the occurrence of selected legacy pollutants in the Arroyo Colorado changed over time?Are current concentrations of legacy pollutants in bottom sediments at levels of concern for the health of aquatic biota?To answer these questions, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA), collected and analyzed a sediment core from Llano Grande Lake on the Arroyo Colorado (fig. 1). Sediment cores can be used to reconstruct historical trends in concentrations of hydrophobic contaminants (Eisenreich and others, 1989; Van Metre and others, 1997, 2000). The lake is part of the Rio Grande delta drainage system (fig. 1). The lake is 6 miles long and has a maximum width of 600 feet.

  15. Landsat sattelite multi-spectral image classification of land cover and land use changes for GIS-based urbanization analysis in irrigation districts of lower Rio Grande Valley of Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lower Rio Grande Valley in the south of Texas is experiencing rapid increase of population to bring up urban growth that continues influencing on the irrigation districts in the region. This study evaluated the Landsat satellite multi-spectral imagery to provide information for GIS-based urbaniz...

  16. Biological studies and field observations in Europe of Lasioptera donacis potential biological control agent of giant reed, Arundo donax, an invasive weed of the Rio Grande Basin of Texas and Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed, Arundo donax L. (Poaceae; Arundinoideae), is a clonal reed grass that is native from the western Mediterranean to India and invasive in North America and other arid temperate/subtropical parts of the world, including the Rio Grande Basin of Texas and Mexico. A biological control of gian...

  17. 78 FR 24329 - Oranges and Grapefruit Grown in Lower Rio Grande Valley in Texas; Increased Assessment Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... increase in advertising and promotion, as well as allow the Committee to replenish funds in its reserves... promotion; $489,500 for the Mexican fruit fly control program; and $243,000 for management, administration... price for Texas citrus during the 2010-11 season was around $11.30 per box and total shipments were...

  18. Life history and life tables of Bactericera cockerelli (Hemiptera: Psyllidae) on potato under laboratory and field conditions in the lower Rio Grande Valley of Texas.

    PubMed

    Yang, Xiang-Bing; Zhang, Yong-Mei; Hua, Lei; Liu, Tong-Xian

    2010-10-01

    Effective management of potato 'Zebra Chip' (ZC) disease caused by Cadidatus Liberibacter psyllaurous (syn. solanacearum) depends on the management of its insect vector insect, potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae). To elucidate the age-specific population dynamics of B. cockerelli, the life-table parameters were determined on potato, Solanum tuberosum L., under both laboratory and field conditions in the Lower Rio Grande Valley (LRGV) of Texas. Generally, survival, fecundity, and longevity of B. cockerelli were significantly greater under laboratory than under field conditions. The mortality under laboratory conditions was mainly due to natural intrinsic mortality. However, under field conditions, most (83.2%) B. cockerelli were missing, and of those that were not, they developed slower, and had shorter preoviposition period, shorter oviposition period, shorter longevity, lower fecundity, and higher mortality than those under laboratory conditions. As a result, most of the life-table parameters of B. cockerelli, including the intrinsic rate of increase, finite rate of increase, and net reproductive rate, were significantly lower in the field under the environmental conditions of the LRGV of Texas than in the laboratory. The information could help increase our understanding of the epidemiology of the ZC diseases associated with the pathogens transmitted by this insect pest.

  19. Factors that contribute to Hispanic English Language Learners' high academic performance in high school science in the Rio Grande Valley of Texas: A multicase study

    NASA Astrophysics Data System (ADS)

    Elizondo, Antonio

    The purpose of this multicase study was to discover factors that contribute to Hispanic English language learners' (ELL) high academic performance in high school science in the Rio Grande Valley of Texas. Participants were high school seniors enrolled in college-level classes who had scored commended on the science exit-level Texas Assessment of Knowledge and Skills and ranked toward the top of their class. One student from each of four different high schools in south Texas were selected to participate. Schools identified students meeting the participant criteria and provided consent documents. In this qualitative research study, students were interviewed on three different dates. Administrators and science teachers were also interviewed for triangulation. Significant findings showed that intrinsic qualities were mainly responsible for factors contributing to high academic performance. Hispanic ELL students need meaningful responsibilities to internalize self-esteem and self-efficacy to realize high academic performance. Self-motivation, a contributing factor, provides students with a positive outlook on high academic performance and the ability to defer more immediate undermining rewards. Students expect to contribute to society by helping others. This helps their self-esteem as well as their self-worth and supports high academic performance. Parental and teacher support are critical for high academic performance. Low socioeconomic status alone is not a causal factor for poor academic performance. School administrations should assign willing and enthusiastic teachers as mentors to target students and provide skills to parents that promote, inspire, and motivate students' intrinsic qualities. Future studies should examine different leadership styles that maximize teachers' ability to influence students' high academic performance. Finally, students should be given guidance in setting career goals and demonstrating that high academic achievement is attainable and

  20. The quality of our Nation's waters: water quality in the Mississippi embayment-Texas coastal uplands aquifer system and Mississippi River Valley alluvial aquifer, south-central United States, 1994-2008

    USGS Publications Warehouse

    Kingsbury, James A.; Barlow, Jeannie R.; Katz, Brian G.; Welch, Heather L.; Tollett, Roland W.; Fahlquist, Lynne S.

    2015-01-01

    About 8 million people rely on groundwater from the Mississippi embayment—Texas coastal uplands aquifer system for drinking water. The Mississippi River Valley alluvial aquifer also provides drinking water for domestic use in rural areas but is of primary importance to the region as a source of water for irrigation. Irrigation withdrawals from this aquifer are among the largest in the Nation and play a key role in the economy of the area, where annual crop sales total more than $7 billion. The reliance of the region on both aquifers for drinking water and irrigation highlights the importance of long-term management to sustain the availability and quality of these resources.

  1. Seepage investigations of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, 2006-13

    USGS Publications Warehouse

    Crilley, D.M.; Matherne, A.M.; Thomas, Nicole; Falk, S.E.

    2013-01-01

    Seepage investigations were conducted annually by the U.S. Geological Survey from 1988 to 1998 and from 2004 to 2013 along a 64-mile reach of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, as part of the Mesilla Basin monitoring program. Results of studies conducted from 2006 to 2013 are presented in this report. Seepage investigations were conducted over a period of 1–2 days in February of each year, during low-flow conditions in the non-irrigation season. During the seepage investigations, discharge was measured at as many as 24 sites along the Rio Grande and as many as 20 inflow sites within the study reach. Net seepage gain or loss was computed for each subreach by subtracting the discharge measured at the upstream location from the discharge measured at the closest downstream location along the river and then subtracting any inflow to the river within the subreach. An estimated gain or loss was determined to be significant when it exceeded the cumulative measurement uncertainty associated with the net seepage computation. Study reaches during 2006 to 2013 ranged from 20.2 to 64 miles in length, and seepage losses ranged from 8.2 ± 3.1 to 47.9 ± 8.2 cubic feet per second.

  2. Seepage investigation of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, 2014

    USGS Publications Warehouse

    Briody, Alyse C.; Robertson, Andrew J.; Thomas, Nicole

    2016-03-22

    Seepage investigations have been conducted annually by the U.S. Geological Survey from 1988 to 1998 and from 2004 to the present (2014) along a 64-mile reach of the Rio Grande from below Leasburg Dam, Leasburg, New Mexico, to above American Dam, El Paso, Texas, as part of the Mesilla Basin monitoring program. Results of the investigation conducted in 2014 are presented in this report. The 2014 seepage investigation was conducted on February 11, 2014, during the low-flow conditions of the non-irrigation season. During the 2014 investigation, discharge was measured at 23 sites along the main-stem Rio Grande and 19 inflow sites within the study reach. Because of extended drought conditions affecting the basin, many sites along the Rio Grande (17 main-stem and 9 inflow) were observed to be dry in February 2014. Water-quality samples were collected during the seepage investigation at sites with flowing water as part of a long-term monitoring effort in the region.Net seepage gain or loss was computed for each subreach (the interval between two adjacent measurement locations along the river) by subtracting the discharge measured at the upstream location from the discharge measured at the closest downstream location along the river and then subtracting any inflow to the river within the subreach. An estimated gain or loss was determined to be meaningful when it exceeded the cumulative measurement uncertainty associated with the net seepage computation. The cumulative seepage loss in the 64-mile study reach in 2014 was 16.0 plus or minus 2.9 cubic feet per second.

  3. Contaminant exposure of willets feeding in agricultural drainages of the Lower Rio Grande Valley of South Texas.

    PubMed

    Custer, T W; Mitchell, C A

    1991-02-01

    Willets (Catoptrophorus semipalmatus) were collected in June and August 1986 at the outlets of two agricultural drainages into the Lower Laguna Madre of South Texas and at two other Texas coastal sites. Mean liver concentration of arsenic was higher in August than June. Over 20% of the livers had arsenic concentrations elevated above a suggested background level of 5.0 ppm dry weight (DW), but concentrations (maximum 15 ppm) were below those associated with acute toxicity. Selenium concentration in livers varied from 2.3 to 8.3 ppm DW for all locations and represented background levels. Mercury concentrations in livers for all locations (means = 2.0 to 3.4, maximum 17 ppm DW) were below those associated with avian mortality and similar to levels found in other estuarine/marine birds. DDE in carcasses was higher in adults (mean = 1.0 ppm wet weight) than juveniles (0.2 ppm), and higher in August (1.0 ppm) than June (0.5 ppm); however, DDE concentrations were generally at background levels. Based on brain cholinesterase activity, willets were not recently exposed to organophosphate pesticides.

  4. Contaminant exposure of willets feeding in agricultural drainages of the lower Rio Grande valley of south Texas

    USGS Publications Warehouse

    Custer, T.W.; Mitchell, C.A.

    1991-01-01

    Willets (Catoptrophorus semipalmatus) were collected in June and August 1986 at the outlets of two agricultural drainages into the Lower Laguna Madre of South Texas and at two other Texas coastal sites. Mean liver concentration of arsenic was higher in August than June. Over 20% of the livers had arsenic concentrations elevated above a suggested background level of 5.0 ppm dry weight (DW), but concentrations (maximum 15 ppm) were below those associated with acute toxicity. Selenium concentration in livers varied from 2.3 to 8.3 ppm DW for all locations and represented background levels. Mercury concentrations in livers for all locations (means = 2.0 to 3.4, maximum 17 ppm DW) were below those associated with avian mortality and similar to levels found in other estuarine/marine birds. DDE in carcasses was higher in adults (mean = 1.0 ppm wet weight) than juveniles (0.2 ppm), and higher in August (1.0 ppm) than June (0.5 ppm); however, DDE concentrations were generally at background levels. Based on brain cholinesterase activity, willets were not recently exposed to organophosphate pesticides.

  5. From Channel to Floodplain: Geomorphic Transformation of the Rio Grande in the Big Bend Region of Texas, Chihuahua, and Coahuila

    NASA Astrophysics Data System (ADS)

    Dean, D. J.; Schmidt, J. C.

    2008-12-01

    Multiple analyses indicate that over the last 17 years on the Rio Grande in Big Bend National Park, a positive feedback mechanism existed between extended base-flows, non-native vegetation invasion, and vertical floodplain accretion which caused rapid channel narrowing and disconnection of the floodplain from the channel. We identified this feedback mechanism using detailed stratigraphic analyses of inset floodplain deposits, dendro-geomorphological analyses of woody vegetation removed from floodplain trenches, hydrologic analyses, and observed shifts in the stage-discharge relation. The active channel width of the Rio Grande has narrowed by 35-50% since 1991. Narrowing has occurred by vertical accretion of fine-grained deposits on top of alternate bars of sand, gravel, and cobbles. These vertically accreting deposits are inset within natural levees. In two long floodplain trenches, we measured 2.75 and 3.5m of vertical accretion, all of which occurred during the past 17 years. In some localities, nearly 90% of bare, active channel bars were converted to vegetated floodplain during the same period. Channel narrowing by vertical accretion coincided with a rapid invasion of non-native riparian vegetation (Tamarix spp., Arundo donax) which increased bank roughness and created a positive feedback of decreased channel capacity, an upward shift of the stage-discharge relation, overbank flooding at lower discharges, and continued vertical accretion. Thus, although peak flows were reduced by 48% and the percent exceedance of both the two-year flood and long- term mean annual flow declined during the past 17 years, overbank flooding continued. These changes reflect a shift in the geomorphic character of the Rio Grande from a wide river with transient channel margins and in-stream geomorphic features to a simple channel with steep, definable, vegetated banks and few bare active geomorphic surfaces.

  6. Streamflow gains and losses and selected water-quality observations in five subreaches of the Rio Grande/Rio Bravo del Norte from near Presidio to Langtry, Texas, Big Bend area, United States and Mexico, 2006

    USGS Publications Warehouse

    Raines, Timothy H.; Turco, Michael J.; Connor, Patrick J.; Bennett, Jeffery B.

    2012-01-01

    Few historical streamflow and water-quality data are available to characterize the segment of the Rio Grande/Rio Bravo del Norte (hereinafter Rio Grande) extending from near Presidio to near Langtry, Texas. The U.S. Geological Survey, in cooperation with the National Park Service and the Texas Commission on Environmental Quality, collected water-quality and streamflow data from the Rio Grande from near Presidio to near Langtry, Texas, to characterize the streamflow gain and loss and selected constituent concentrations in a 336.3-mile reach of the Rio Grande from near Presidio to near Langtry, Texas. Streamflow was measured at 38 sites and water-quality samples were collected at 20 sites along the Rio Grande in February, March, and June 2006. Streamflow gains and losses over the course of the stream were measured indirectly by computing the differences in measured streamflow between sites along the stream. Water-quality data were collected and analyzed for salinity, dissolved solids, major ions, nutrients, trace elements, and stable isotopes. Selected properties and constituents were compared to available Texas Commission on Environmental Quality general use protection criteria or screening levels. Summary statistics of selected water-quality data were computed for each of the five designated subreaches. Streamflow gain and loss and water-quality constituent concentration were compared for each subreach, rather than the entire segment because of the temporal variation in sample collection caused by controlled releases upstream. Subreach A was determined to be a losing reach, and subreaches B, C, D, and E were determined to be gaining reaches. Compared to concentrations measured in upstream subreaches, downstream subreaches exhibited evidence of dilution of selected constituent concentrations. Subreaches A and B had measured total dissolved solids, chloride, and sulfate exceeding the Texas Commission on Environmental Quality general use protection criteria

  7. Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas

    USGS Publications Warehouse

    Sitzlar, M.A.; Mora, M.A.; Fleming, J.G.W.; Bazer, F.W.; Bickham, J.W.; Matson, C.W.

    2009-01-01

    Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies. ?? 2008 Springer Science+Business Media, LLC.

  8. Crustal structure of the northern mississippi embayment and a comparison with other continental rift zones

    USGS Publications Warehouse

    Mooney, W.D.; Andrews, M.C.; Ginzburg, A.; Peters, D.A.; Hamilton, R.M.

    1983-01-01

    Previous geological and geophysical investigations have suggested that the Mississippi Embayment is the site of a Late Precambrian continental rift that was reactivated in the Mesozoic. New information on the deep structure of the northern Mississippi Embayment, gained through an extensive seismic refraction survey, supports a rifting hypothesis. The data indicate that the crust of the Mississippi Embayment may be characterized by six primary layers that correspond geologically to unconsolidated Mesozoic and Tertiary sediments (1.8 km/s), Paleozoic carbonate and clastic sedimentary rocks (5.9 km/s), a low-velocity layer of Early Paleozoic sediments (4.9 km/s), crystalline upper crust (6.2 km/s), lower crust (6.6 km/s), modified lower crust (7.3 km/s), and mantle. Average crustal thickness is approximately 41 km. The presence and configuration of the low-velocity layer provide new evidence for rifting in the Mississippi Embayment. The layer lies within the northeast-trending upper-crustal graben reported by Kane et al. (1981), and probably represents marine shales deposited in the graben after rifting. The confirmation and delineation of a 7.3 km/s layer, identified in previous studies, implies that the lower crust has been altered by injection of mantle material. Our results indicate that this layer reaches a maximum thickness in the north-central Embayment and thins gradually to the southeast and northwest, and more rapidly to the southwest along the axis of the graben. The apparent doming of the 7.3 km/s layer in the north-central Embayment suggests that rifting may be the result of a triple junction located in the Reelfoot Basin area. The crustal structure of the Mississippi Embayment is compared to other continental rifts: the Rhinegraben, Limagnegraben, Rio Grande Rift, Gregory Rift, and the Salton Trough. This comparison suggests that alteration of the lower crust is a ubiquitous feature of continental rifts. ?? 1983.

  9. Stratigraphic, sedimentologic, and dendrogeomorphic analyses of rapid floodplain formation along the Rio Grande in Big Bend National Park, Texas

    USGS Publications Warehouse

    Dean, D.J.; Scott, M.L.; Shafroth, P.B.; Schmidt, J.C.

    2011-01-01

    The channel of the lower Rio Grande in the Big Bend region rapidly narrows during years of low mean and peak flow. We conducted stratigraphic, sedimentologic, and dendrogeomorphic analyses within two long floodplain trenches to precisely reconstruct the timing and processes of recent floodplain formation. We show that the channel of the Rio Grande narrowed through the oblique and vertical accretion of inset floodplains following channel-widening floods in 1978 and 1990-1991. Vertical accretion occurred at high rates, ranging from 16 to 35 cm/yr. Dendrogeomorphic analyses show that the onset of channel narrowing occurred during low-flow years when channel bars obliquely and vertically accreted fine sediment. This initial stage of accretion occurred by both bedload and suspended-load deposition within the active channel. Vegetation became established on top of these fine-grained deposits during years of low peak flow and stabilized these developing surfaces. Subsequent deposition by moderate floods (between 1.5 and 7 yr recurrence intervals) caused additional accretion at rapid rates. Suspended-sediment deposition was dominant in the upper deposits, resulting in the formation of natural levees at the channel margins and the deposition of horizontally bedded, fining-upward deposits in the floodplain trough. Overall, channel narrowing and floodplain formation occurred through an evolution from active-channel to floodplain depositional processes. High-resolution dendrogeomorphic analyses provide the ability to specifically correlate the flow record to the onset of narrowing, the establishment of riparian vegetation, the formation of natural levees, and ultimately, the conversion of portions of the active channel to floodplains. ?? 2011 Geological Society of America.

  10. Evaluation of soil sustainability along the Rio Grande in West Texas: changes in salt loading and organic nutrients due to farming practices

    NASA Astrophysics Data System (ADS)

    Cox, C. L.; Ganjegunte, G.; Borrok, D. M.; Lougheed, V.; Ma, L.; Jin, L.

    2011-12-01

    thus have higher salt loading, and that Cotton has a higher clay content. The EC values continuously increase from irrigation water to soil waters, suggesting that as water travels through the soil profile it increases in salinity. Consistent with this observation, cation concentrations in soil waters increased with depth. Therefore, the salts within the soils are mobilized during irrigation. 5TE sensors at all three depths in the field showed spikes in EC, and soil moisture during each period of flood irrigation. Data also suggests a lower bulk EC between irrigation periods which might result from a lower soil moisture content which doesn't solublize the salts. The carbonate- and gypsum- rich soils and surface water in the Rio Grande Basin change with intensity and amount of irrigation, addition of fertilizers, and other agricultural practices. Results from this project contribute to our understanding of salt loading and nutrient cycling in the vulnerable area of the Rio Grande Valley in West Texas.

  11. Aspergillus parasiticus communities associated with sugarcane in the Rio Grande Valley of Texas: implications of global transport and host association within Aspergillus section Flavi.

    PubMed

    Garber, N P; Cotty, P J

    2014-05-01

    In the Rio Grande Valley of Texas (RGV), values of maize and cottonseed crops are significantly reduced by aflatoxin contamination. Aflatoxin contamination of susceptible crops is the product of communities of aflatoxin producers and the average aflatoxin-producing potentials of these communities influence aflatoxin contamination risk. Cropping pattern influences community composition and, thereby, the epidemiology of aflatoxin contamination. In 2004, Aspergillus parasiticus was isolated from two fields previously cropped to sugarcane but not from 23 fields without recent history of sugarcane cultivation. In 2004 and 2005, A. parasiticus composed 18 to 36% of Aspergillus section Flavi resident in agricultural soils within sugarcane-producing counties. A. parasiticus was not detected in counties that do not produce sugarcane. Aspergillus section Flavi soil communities within sugarcane-producing counties differed significantly dependent on sugarcane cropping history. Fields cropped to sugarcane within the previous 5 years had greater quantities of A. parasiticus (mean = 16 CFU/g) than fields not cropped to sugarcane (mean = 0.1 CFU/g). The percentage of Aspergillus section Flavi composed of A. parasiticus increased to 65% under continuous sugarcane cultivation and remained high the first season of rotation out of sugarcane. Section Flavi communities in fields rotated to non-sugarcane crops for 3 to 5 years were composed of <5% A. parasiticus, and fields with no sugarcane history averaged only 0.2% A. parasiticus. The section Flavi community infecting RGV sugarcane stems ranged from 95% A. parasiticus in billets prepared for commercial planting to 52% A. parasiticus in hand-collected sugarcane stems. Vegetative compatibility assays and multilocus phylogenies verified that aflatoxin contamination of raw sugar was previously attributed to similar A. parasiticus in Japan. Association of closely related A. parasiticus genotypes with sugarcane produced in Japan and RGV

  12. Texas Greenup

    NASA Technical Reports Server (NTRS)

    2007-01-01

    June 2007 was one of the wettest Junes on record for the state of Texas. Starting in late May, a string of low-pressure systems settled in over the U.S. Southern Plains and unleashed weeks of heavy to torrential rain. During the final week of June, much of Texas, Oklahoma, and Kansas received more than 330 percent of their average rainfall, said the National Climatic Data Center. The widespread heavy rain brought deadly floods to the entire region. On July 6, the Associated Press reported that every major river basin in Texas was at flood stage, an event that had not occurred since 1957. In addition to causing floods, the rains stimulated plant growth. The grassy, often arid, plains and plateaus of northern Mexico (bottom left), Texas (center), and New Mexico (top, left of center) burst to life with dense vegetation as this vegetation anomaly image shows. Regions where plants were growing more quickly or fuller than average are green, while areas where growth is below average are brown. Most of Texas is green, with a concentrated deep green, almost black, spot where vegetation growth was greatest. This area of western Texas is where the Pecos River flows out of New Mexico and heads southeast to the Rio Grande. In the darkest areas, vegetation was more than 100 percent above average. The brown spots in northeastern Texas and Oklahoma (top, right of center) may be areas where persistent clouds or water on the ground are hiding the plants from the satellite's view. Plants may also be growing less than average if swamped by too much rain. The image was made with data collected by the SPOT satellite between June 11 and June 20, 2007. NASA imagery created by Jesse Allen, Earth Observatory, using SPOT data provided courtesy of the USDA Foreign Agricultural Service and processed by Jennifer Small and Assaf Anyamba of the GIMMS Group at NASA GSFC.

  13. Comparative phylogeography of Mississippi embayment fishes.

    PubMed

    Egge, Jacob J D; Hagbo, Taylor J

    2015-01-01

    The Mississippi Embayment is a prominent physiographic feature of eastern North America consisting of primarily lowland aquatic habitats and a fish fauna that is largely distinct from nearby highland regions. Numerous studies have demonstrated that both pre-Pleistocene and Pleistocene events have had a strong influence on the distributions and relationships of highland fishes in eastern North America. However, the extent to which these same events affected Embayment distributed taxa remains largely unexplored. The purpose of this study was to investigate the relative roles of pre-Pleistocene and Pleistocene events in shaping phylogeographic relationships of four stream dwelling fishes in the Mississippi Embayment. Molecular genetic analyses of the mitochondrial gene cytochrome b were performed for three ictalurid catfish species (Noturus miurus, n = 67; Noturus hildebrandi, n = 93, and Noturus phaeus, n = 44) and one minnow species (Cyprinella camura, n = 78), all distributed in tributary streams of the Mississippi Embayment. Phylogenetic relationships and divergence times among haplotypes for each species were estimated using maximum likelihood and Bayesian methods. Phylogenetic analyses recovered 6 major haplotype clades within N. miurus, 5 within N. hildbrandi, 8 within N. phaeus, and 8 within C. camura. All three Noturus species show a high degree of isolation by drainage, which is less evident in C. camura. A clade of haplotypes from tributaries in the southern portion of the Mississippi Embayment was consistently recovered in all four species. Divergence times among clades spanned the Pleistocene, Pliocene, and Miocene. Novel relationships presented here for C. camura and N. phaeus suggest the potential for cryptic species. Pre-Pleistocene and Pleistocene era sea level fluctuations coincide with some divergence events, but no single event explains any common divergence across all taxa. Like their highland relatives, a combination of both pre-Pleistocene and

  14. Comparative Phylogeography of Mississippi Embayment Fishes

    PubMed Central

    Egge, Jacob J. D.; Hagbo, Taylor J.

    2015-01-01

    The Mississippi Embayment is a prominent physiographic feature of eastern North America consisting of primarily lowland aquatic habitats and a fish fauna that is largely distinct from nearby highland regions. Numerous studies have demonstrated that both pre-Pleistocene and Pleistocene events have had a strong influence on the distributions and relationships of highland fishes in eastern North America. However, the extent to which these same events affected Embayment distributed taxa remains largely unexplored. The purpose of this study was to investigate the relative roles of pre-Pleistocene and Pleistocene events in shaping phylogeographic relationships of four stream dwelling fishes in the Mississippi Embayment. Molecular genetic analyses of the mitochondrial gene cytochrome b were performed for three ictalurid catfish species (Noturus miurus, n = 67; Noturus hildebrandi, n = 93, and Noturus phaeus, n = 44) and one minnow species (Cyprinella camura, n = 78), all distributed in tributary streams of the Mississippi Embayment. Phylogenetic relationships and divergence times among haplotypes for each species were estimated using maximum likelihood and Bayesian methods. Phylogenetic analyses recovered 6 major haplotype clades within N. miurus, 5 within N. hildbrandi, 8 within N. phaeus, and 8 within C. camura. All three Noturus species show a high degree of isolation by drainage, which is less evident in C. camura. A clade of haplotypes from tributaries in the southern portion of the Mississippi Embayment was consistently recovered in all four species. Divergence times among clades spanned the Pleistocene, Pliocene, and Miocene. Novel relationships presented here for C. camura and N. phaeus suggest the potential for cryptic species. Pre-Pleistocene and Pleistocene era sea level fluctuations coincide with some divergence events, but no single event explains any common divergence across all taxa. Like their highland relatives, a combination of both pre-Pleistocene and

  15. Mesohabitats, fish assemblage composition, and mesohabitat use of the Rio Grande silvery minnow over a range of seasonal flow regimes in the Rio Grande/Rio Bravo del Norte, in and near Big Bend National Park, Texas, 2010-11

    USGS Publications Warehouse

    Moring, J. Bruce; Braun, Christopher L.; Pearson, Daniel K.

    2014-01-01

    There were no statistically significant differences between the stream velocities associated with seine hauls of the Rio Grande silvery minnow and Tamaulipas shiner. Stream velocities associated with the seine hauls that included Rio Grande silvery minnow indicate that this species is predominantly found in low-velocity mesohabitats. Velocities associated with seine hauls that included the Tamaulipas shiner represented a much broader overall range of velocities than those associated with Rio Grande silvery minnow collections. No statistically significant differences were found between the depths for seine hauls that included Rio Grande silvery minnow or Tamaulipas shiner. The Rio Grande silvery minnow was more commonly collected in seine hauls from mesohabitats dominated by cobble substrates and less frequently collected in mesohabitats with substrates dominated by fine-sized silt and clay particles, gravels, and sands, in that order. In contrast, the Tamaulipas shiner was broadly distributed among mesohabitats characterized as having gravel, cobble, and silt and clay.

  16. An integrated geological and geophysical study of the Uinta Mountains, Utah, Colorado and a geophysical study on Tamarix in the Rio Grande River basin, West Texas

    NASA Astrophysics Data System (ADS)

    Khatun, Salma

    2008-07-01

    comprehensive picture of the structures in the study area. These models show that the Uinta uplift is a single sedimentary block with numerous thrust faults on the northern and southern flanks of the uplift. These models also reveal the fact that the thickness of the crust is quite variable in the study area. This is also supported by the crustal thickness map constructed for this study from seismic and receiver function information. Magnetic maps show that the Proterozoic sedimentary package known as Uinta Mountain Group extends into the Basin and Range and indicates its link with the ancient rift margin in the Western United States. Findings of this research are correlated to earlier studies and placed in a broader context. Finally an analogy is made between the Uinta aulacogen, the Southern Oklahoma aulacogen and the Dniepr-Donets aulacogen in Ukraine. This discussion focuses light on the mechanism that led to the Uinta's development from a failed rift to an uplift. Part two of this research examined the effect of saltcedar (Tamarix sp) on water and soil properties in the Rio Grande River valley in West Texas. Tamarix is a woody phreatophyte (water-loving plant) common in riparian habitats. The presence of Tamarix in a river system raises concerns about its effect on water quality because it can increase the salinity of water and surrounding soil and it reduces stream flow. Geophysical electrical techniques were used to track soil salinity and moisture changes caused by Tamarix, as well as to determine how soil salinity and moisture properties are altered when Tamarix is eradicated from the region. These techniques allowed more rapid in-situ assessment of the soil properties than the conventional method of removing soil and water samples for analysis. This study was focused on the influence of Tamarix on soil properties and hydrology at the subsurface at four sites in the Rio Bosque Wetlands Park, El Paso, Texas Two sites had flourishing Tamarix and two others were areas

  17. Rio Grande Wetbacks: Mexican Migrant Workers.

    ERIC Educational Resources Information Center

    Norquest, Carrol

    Farmers in the Lower Rio Grande Valley of Texas saw a rise of wetback labor in the 1930s and 40s. The wetback laborers were Mexicans who had crossed the Rio Grande and were in the United States illegally to work. Carrol Norquest, a farmer in the Lower Rio Grande Valley, employed wetbacks regularly. In this book, Mr. Norquest writes about the…

  18. Seasonality and movement of adventive populations of the arundo wasp (Hymenoptera: Eurytomidae), a biological control agent of giant reed in the Lower Rio Grande Basin in south Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The arundo wasp, Tetramesa romana, has been permitted as a biological control agent for the invasive perennial grass, Arundo donax. Evidence of adventive populations of the arundo wasp in the Lower Rio Grande Basin was confirmed with a spatio-temporal survey spanning more than 350 river miles. A ...

  19. Impact of the biological control agent, Tetramesa romana (Hymenoptera: Eurytomidae) on Arundo donax (Poaceae: Arundinoideae) along the Rio Grande River in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five years post release of 1.2 million arundo wasps, Tetramesa romana, into the riparian habitats of the lower Rio Grande River; changes in the health the invasive weed, Arundo donax, giant reed have been documented. These changes in plant attributes are fairly consistent along the 558 river miles b...

  20. Isotopic and Hydraulic Head Evidence for Cross-formational Leakage of Saline Water From the Rio Grande Alluvium to the Hueco Bolson Aquifer, Trans-Pecos Texas

    NASA Astrophysics Data System (ADS)

    Hibbs, B. J.; Eastoe, C. J.; Bangs, E.; Reinert, S.

    2002-12-01

    The twin-cities of El Paso and Juarez share the water resources of the Hueco Bolson, a Tertiary and Quaternary basin fill aquifer that spans the international border. Artesian conditions existed in the El Paso-Juarez Valley during predevelopment times, and dilute groundwaters in the Hueco Bolson flowed upward and mixed with the mineralized water in the shallow Rio Grande alluvium (alluvial deposits less than 60 m thick). The hydraulic gradient has been reversed since predevelopment times by heavy municipal pumping in the Hueco Bolson aquifer, and many of the deeper wells in the El Paso-Juarez Valley have been retired due to salinity exceeding 1500 mg/L TDS. Previous studies based on groundwater modeling suggested that salinity increased in deeper wells due to induced leakage of saline water from the shallow Rio Grande alluvium. Hydrochemical, isotopic and hydraulic head data collected in this study support this model. Tritium levels in several deeper wells in the El Paso-Juarez Valley (screens set from 90 to 210 m) vary from 1.2 to 7.9 TU, indicating post-bomb water from leakage from the Rio Grande and Rio Grande alluvium. The hydraulic head gradient is oriented vertically downward between the alluvial and bolson aquifers, reaching 0.14 (27 m/189 m) in one well nest. Groundwater from the same well nest gives δ18O and δ2H values plotting along a mixing curve, representing evaporated and saline waters in shallow alluvial wells (-7.2 to -8.3 δ18O \\permil, -66 to -71 δ2H \\permil), meteoric and dilute waters in the deepest bolson well (-10.7 δ18O \\permil, -76 δ2H \\permil), and intermediate and mixed saline water in middle bolson wells (-9.8 to -10.3 δ18O \\permil, -76 to -77 δ2H \\permil).

  1. Water resources data Texas, water year 2004, volume 5. Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Long, Susan C. Aragon; Reece, Brian D.; Eames, Deanna R.

    2005-01-01

    Water-resources data for the 2004 water year for Texas are presented in six volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 5 contains records for water discharge at 86 gaging stations; stage only at 5 gaging stations; elevation at 3 lakes and reservoirs; content at 4 lakes and reservoirs;and water quality at 24 gaging stations. Also included are data for 16 partial-record stations comprised of 1 flood-hydrograph, 11 low-flow, and 4 crest-stage stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  2. Water resources data Texas water year 2002, volume 5. Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Gandara, Susan C.

    2003-01-01

    Water-resources data for the 2002 water year for Texas are presented in six volumes and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 5 contains records for water discharge at 82 gaging stations; stage only at 6 gaging stations; stage and contents at 8 lakes and reservoirs; water quality at 25 gaging stations; and data for 30 partial-record stations comprised of 2 flood-hydrograph, 6 low-flow, 4 crest-stage, and 18 miscellaneous stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  3. Water resources data Texas water year 2001, volume 5. Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Gandara, Susan C.

    2002-01-01

    Water-resources data for the 2001 water year for Texas are presented in six volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 5 contains records for water discharge at 77 gaging stations; stage only at 4 gaging stations; stage and contents at 5 lakes and reservoirs; water quality at 27 gaging stations; and data for 23 partial-record stations comprised of 3 flood-hydrograph, 8 low-flow, 4 crest-stage, and 3 miscellaneous stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  4. Water resources data Texas water year 2003, volume 5. Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Gandara, Susan C.

    2004-01-01

    Water-resources data for the 2003 water year for Texas are presented in six volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 5 contains records for water discharge at 84 gaging stations; stage only at 6 gaging stations; stage and contents at 6 lakes and reservoirs; water quality at 28 gaging stations; and data for 18 partial-record stations comprised of 1 flood-hydrograph, 10 low-flow, 4 crest-stage, and 3 miscellaneous stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  5. Water resources data Texas water year 1999, volume 5. Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Gandara, S.C.; Gibbons, W.J.; Barbie, D.L.; Jones, R.E.

    2000-01-01

    Water-resources data for the 1999 water year for Texas are presented in six volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 5 contains records for water discharge at 76 gaging stations; stage only at 1 gaging stations; stage and contents at 4 lakes and reservoirs; water quality at 38 gaging stations; and data for 30 partial-record stations comprised of 3 flood-hydrograph, 14 low-flow, and 8 crest-stage, and 5 miscellaneous stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  6. Water resources data, Texas water year 1998, volume 3. Colorado River basin, Lavaca River basin, Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Gandara, S.C.; Gibbons, W.J.; Andrews, F.L.; Barbie, D.L.

    1999-01-01

    Water-resources data for the 1998 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 3 contains records for water discharge at 126 gaging stations; stage only at 3 gaging stations; stage and contents at 15 lakes and reservoirs; water quality at 62 gaging stations; and data for 35 partial-record stations comprised of 8 flood-hydrograph, 14 low-flow, and 18 creststage, and 5 miscellaneous stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  7. Water resources data Texas water year 2000, volume 5. Guadalupe River basin, Nueces River basin, Rio Grande basin, and intervening coastal basins

    USGS Publications Warehouse

    Gandara, S.C.; Gibbons, W.J.; Barbie, D.L.

    2001-01-01

    Water-resources data for the 2000 water year for Texas are presented in six volumes, and consist of records of stage, discharge, and water quality of streams and canals; stage, contents, and water-quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 5 contains records for water discharge at 71 gaging stations; stage only at 4 gaging stations; stage and contents at 4 lakes and reservoirs; water quality at 29 gaging stations; and data for 23 partial-record stations comprised of 3 flood-hydrograph, 10 low-flow, 6 crest-stage, and 4 miscellaneous stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations. Additional water data were collected at various sites, not part of the systematic data-collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal, State, and local agencies in Texas. Records for a few pertinent stations in the bordering States also are included.

  8. Usage and administration manual for a geodatabase compendium of water-resources data-Rio Grande Basin from the Rio Arriba-Sandoval County line, New Mexico, to Presidio, Texas, 1889-2009

    USGS Publications Warehouse

    Burley, Thomas E.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the New Mexico Interstate Stream Commission, developed a geodatabase compendium (hereinafter referred to as the 'geodatabase') of available water-resources data for the reach of the Rio Grande from Rio Arriba-Sandoval County line, New Mexico, to Presidio, Texas. Since 1889, a wealth of water-resources data has been collected in the Rio Grande Basin from Rio Arriba-Sandoval County line, New Mexico, to Presidio, Texas, for a variety of purposes. Collecting agencies, researchers, and organizations have included the U.S. Geological Survey, Bureau of Reclamation, International Boundary and Water Commission, State agencies, irrigation districts, municipal water utilities, universities, and other entities. About 1,750 data records were recently (2010) evaluated to enhance their usability by compiling them into a single geospatial relational database (geodatabase). This report is intended as a user's manual and administration guide for the geodatabase. All data available, including water quality, water level, and discharge data (both instantaneous and daily) from January 1, 1889, through December 17, 2009, were compiled for the study area. A flexible and efficient geodatabase design was used, enhancing the ability of the geodatabase to handle data from diverse sources and helping to ensure sustainability of the geodatabase with long-term maintenance. Geodatabase tables include daily data values, site locations and information, sample event information, and parameters, as well as data sources and collecting agencies. The end products of this effort are a comprehensive water-resources geodatabase that enables the visualization of primary sampling sites for surface discharges, groundwater elevations, and water-quality and associated data for the study area. In addition, repeatable data processing scripts, Structured Query Language queries for loading prepared data sources, and a detailed process for refreshing all data in the

  9. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas; organic compounds and trace elements in bed sediment and fish tissue, 1992-93

    USGS Publications Warehouse

    Carter, L.F.; Anderholm, S.K.

    1997-01-01

    The occurrence and distribution of contaminants in aquatic systems are major components of the National Water-Quality Assessment (NAWQA) Program. Bed-sediment samples were collected at 18 sites in the Rio Grande Valley study unit between September 1992 and March 1993 to characterize the geographic distribution of organic compounds, including chlorinated insecticides, polychlorinated biphenyls (PCB's), and other chlorinated hydrocarbons, and also trace elements. Two-millimeter-size- fraction sediment was analyzed for organic compounds and less than 63-micron-size-fraction sediment was analyzed for trace elements. Concentrations of p,p'-DDE were detected in 33 percent of the bed-sediment samples. With the exception of DDT-related compounds, no other organochlorine insecticides or polychlorinated biphenyls were detected in samples of bed sediment. Whole-body fish samples were collected at 11 of the bed- sediment sites and analyzed for organic compounds. Organic compounds were reported more frequently in samples of fish, and more types of organic compounds were found in whole-body fish samples than in bed-sediment samples. Concentrations of p,p'-DDE were detected in 91 percent of whole-body fish samples. Polychlorinated biphenyls, cis-chlordane, trans-chlordane, trans- nonachlor, and hexachlorobenzene were other organic compounds detected in whole-body samples of fish from at least one site. Because of the extent of mineralized areas in the Rio Grande Basin arsenic, cadmium, copper, lead, mercury, selenium, and zinc concentrations in bed-sediment samples could represent natural conditions at most sites. However, a combination of natural conditions and human activities appears to be associated with elevated trace-element concentrations in the bed-sediment sample from the site Rio Grande near Creede, Colorado, because this sample exceeded the background trace-element concentrations calculated for this study. Fish-liver samples were collected at 12 of the bed

  10. Design and Compilation of a Geodatabase of Existing Salinity Information for the Rio Grande Basin, from the Rio Arriba-Sandoval County Line, New Mexico, to Presidio, Texas, 2010

    USGS Publications Warehouse

    Shah, Sachin D.; Maltby, David R.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, compiled salinity-related water-quality data and information in a geodatabase containing more than 6,000 sampling sites. The geodatabase was designed as a tool for water-resource management and includes readily available digital data sources from the U.S. Geological Survey, U.S. Environmental Protection Agency, New Mexico Interstate Stream Commission, Sustainability of semi-Arid Hydrology and Riparian Areas, Paso del Norte Watershed Council, numerous other State and local databases, and selected databases maintained by the University of Arizona and New Mexico State University. Salinity information was compiled for an approximately 26,000-square-mile area of the Rio Grande Basin from the Rio Arriba-Sandoval County line, New Mexico, to Presidio, Texas. The geodatabase relates the spatial location of sampling sites with salinity-related water-quality data reported by multiple agencies. The sampling sites are stored in a geodatabase feature class; each site is linked by a relationship class to the corresponding sample and results stored in data tables.

  11. Plant water use characteristics of five dominant shrub species of the Lower Rio Grande Valley, Texas, USA: implications for shrubland restoration and conservation.

    PubMed

    Adhikari, Arjun; White, Joseph D

    2014-01-01

    The biogeographic distribution of plant species is inherently associated with the plasticity of physiological adaptations to environmental variation. For semi-arid shrublands with a legacy of saline soils, characterization of soil water-tolerant shrub species is necessary for habitat restoration given future projection of increased drought magnitude and persistence in these ecosystems. Five dominant native shrub species commonly found in the Lower Rio Grande Valley, TX, USA, were studied, namely Acacia farnesiana, Celtis ehrenbergiana, Forestiera angustifolia, Parkinsonia aculeata and Prosopis glandulosa. To simulate drought conditions, we suspended watering of healthy, greenhouse-grown plants for 4 weeks. Effects of soil salinity were also studied by dosing plants with 10% NaCl solution with suspended watering. For soil water deficit treatment, the soil water potential of P. glandulosa was the highest (-1.20 MPa), followed by A. farnesiana (-4.69 MPa), P. aculeata (-5.39 MPa), F. angustifolia (-6.20 MPa) and C. ehrenbergiana (-10.02 MPa). For the soil salinity treatment, P. glandulosa also had the highest soil water potential value (-1.60 MPa), followed by C. ehrenbergiana (-1.70 MPa), A. farnesiana (-1.84 MPa), P. aculeata (-2.04 MPa) and F. angustifolia (-6.99 MPa). Within the species, only C. ehrenbergiana and F. angustifolia for soil water deficit treatment and A. farnesiana for the salinity treatment had significantly lower soil water potential after 4 weeks of treatment (P < 0.05). We found that soil water potential, stomatal conductance and net photosynthesis of the species significantly reduced over time for both treatments (P < 0.05). We conclude that while all species exhibited capacities to withstand current water availability, some species demonstrated limited tolerance for extreme water stress that may be important for management of future shrub diversity in Lower Rio Grande Valley.

  12. Status of fish communities in the Rio Grande, Big Bend National Park, Texas - comparison before and after Spring 2003 period of low flow

    USGS Publications Warehouse

    Moring, J. Bruce

    2005-01-01

    During 2003–04 the U.S. Geological Survey, in cooperation with the National Park Service, re-evaluated the status of fish communities in three reaches of the Rio Grande in Big Bend National Park that originally were evaluated when the three reaches were established for study in 1999. The objective was to determine whether there were measurable differences between 1999 and 2003–04 (referred to as 2004) fish community status that likely are attributable to a rare 58-day period of low flow (less than 1 cubic meter per second) in spring 2003 at the Johnson Ranch gaging station on the Rio Grande in Big Bend National Park. The total number of fish species collected at all three sites (Boquillas, Johnson Ranch, and Santa Elena) in 1999 was greater than in 2004. The number of fish species collected at the Boquillas site in 1999 (10) was twice that collected in 2004; the number of species collected at the Johnson Ranch site in 1999 (nine) was almost twice that collected in 2004 (five). In contrast, the numbers at the Santa Elena site were nearly the same, 15 species in 1999, 14 in 2004. Percent community similarity for the Boquillas site is 8.04, for the Johnson Ranch site, 6.65, and for the Santa Elena site, 47.6, which indicates considerably more similarity between the 1999 and 2004 fish communities at the Santa Elena site than for the Boquillas and Johnson Ranch sites. At the Boquillas and Johnson Ranch sites, the fish communities shifted from small minnow (Cyprinidae) dominated in 1999 to largely gar (Lepisosteidae) and catfish (Ictaluridae) dominated in 2004. In contrast, no such shift occurred at the Santa Elena site between 1999 and 2004. Differences in flow conditions between the two downstream sites and the Santa Elena site might account for the dissimilar findings. The findings of the study provide some evidence that the spring 2003 period of low flow affected fish communities, but the findings are not definitive as other factors such as increased salinity

  13. Interpretation of Late Cretaceous Volcanic Mounds and Surrounding Gulfian Series Formations Using 3D Seismic Data in Zavala County, Texas

    NASA Astrophysics Data System (ADS)

    Bennett, Laura Claire

    The Late Cretaceous Gulfian series is a prominent and important series across the State of Texas that has been extensively studied since the nineteenth century. It is composed of series of southeast-dipping shelf carbonates and clastics deposited on the northwest margin of the Gulf of Mexico Basin. In south Texas, the Gulfian series was deposited in the Rio Grande Embayment and Maverick Basin and is comprised of the Eagle Ford Group, Austin Group, Anacacho Limestone, San Miguel Formation, Olmos Formation, and Escondido Formation that crop out and continue basinward in the subsurface. Late Cretaceous volcanism formed volcanic mounds composed of altered palagonite tuff that are clustered into two fields, including the Uvalde Field centered in Zavala County. Using the Pedernales 3D seismic survey, located in east-central Zavala County, several volcanic mounds were identified and mapped without the use of well log data by identifying structures and characteristics associated with the volcanic mounds. Isolating these mounds through mapping enabled the mapping of the tops surrounding Gulfian formations, Lower Eagle Ford, Upper Eagle Ford, Austin, Anacacho, and San Miguel, for which time-structure, amplitude, similarity/coherency attribute, and isochron maps were generated. By using 3D seismic data, the volcanic mounds and their relation to surrounding rocks can be better interpreted.

  14. Variability of surface-water quantity and quality and shallow groundwater levels and quality within the Rio Grande Project Area, New Mexico and Texas, 2009–13

    USGS Publications Warehouse

    Driscoll, Jessica M.; Sherson, Lauren R.

    2016-03-15

    Drought conditions during the study period of January 1, 2009, to September 30, 2013, caused a reduction in surface-water releases from water-supply storage infrastructure of the Rio Grande Project, which led to changes in surface-water and groundwater (conjunctive) use in downstream agricultural alluvial valleys. Surface water and groundwater in the agriculturally dominated alluvial Rincon and Mesilla Valleys were investigated in this study to measure the influence of drought and subsequent change in conjunctive water use on quantity and quality of these water resources. In 2013, the U.S. Geological Survey, in cooperation with the New Mexico Environment Department and the New Mexico Interstate Stream Commission, began a study to (1) calculate dissolved-solids loads over the study period at streamgages in the study area where data are available, (2) assess the temporal variability of dissolved-solids loads at and between each streamgage where data are available, and (3) relate the spatiotemporal variability of shallow groundwater data (groundwater levels and quality) within the alluvial valleys of the study area to spatiotemporal variability of surface-water data over the study period. This assessment included the calculation of surface-water dissolved-solids loads at streamgages as well as a mass-balance approach to measure the change in salt load between these streamgages. Bimodal surface-water discharge data led to a temporally-dynamic volumetric definition of release and nonrelease seasons. Continuous surface-water discharge and water-quality data from three streamgages on the Rio Grande were used to calculate daily dissolved-solids loads over the study period, and the results were aggregated annually and seasonally. Results show the majority of dissolved-solids loading occurs during release season; however, decreased duration of the release season over the 5-year study period has resulted in a decrease of the total annual loads at each streamgage

  15. Baseline assessment of instream and riparian-zone biological resources on the Rio Grande in and near Big Bend National Park, Texas

    USGS Publications Warehouse

    Moring, James Bruce

    2002-01-01

    Five study sites, and a sampling reach within each site, were established on the Rio Grande in and near Big Bend National Park in 1999 to provide the National Park Service with data and information on the status of stream habitat, fish communities, and benthic macroinvertebrates. Differences in stream-habitat conditions and riparian vegetation reflect differences in surface geology among the five sampling reaches. In the most upstream reach, Colorado Canyon, where igneous rock predominates, streambed material is larger; and riparian vegetation is less diverse and not as dense as in the four other, mostly limestone reaches. Eighteen species of fish and a total of 474 individuals were collected among the five reaches; 348 of the 474 were minnows. The most fish species (15) were collected at the Santa Elena reach and the fewest species (9) at the Colorado Canyon and Johnson Ranch reaches. The fish community at Colorado Canyon was least like the fish communities at the four other reaches. Fish trophic structure reflected fish-community structure among the five reaches. Invertivores made up at least 60 percent of the trophic structure at all reaches except Colorado Canyon. Piscivores dominated the trophic structure at Colorado Canyon. At the four other reaches, piscivores were the smallest trophic group. Eighty percent of the benthic macroinvertebrate taxa collected were aquatic insects. Two species of blackfly were the most frequently collected invertebrate taxon. Net-spinning caddisflies were common at all reaches except Santa Elena. The aquatic-insect community at the Boquillas reach was least similar to the aquatic-insect community at the other reaches.

  16. Groundwater availability of the Mississippi embayment

    USGS Publications Warehouse

    Clark, Brian R.; Hart, Rheannon M.; Gurdak, Jason J.

    2011-01-01

    Groundwater is an important resource for agricultural and municipal uses in the Mississippi embayment. Arkansas ranks first in the Nation for rice and third for cotton production, with both crops dependent on groundwater as a major source of irrigation requirements. Multiple municipalities rely on the groundwater resources to provide water for industrial and public use, which includes the city of Memphis, Tennessee. The demand for the groundwater resource has resulted in groundwater availability issues in the Mississippi embayment including: (1) declining groundwater levels of 50 feet or more in the Mississippi River Valley alluvial aquifer in parts of eastern Arkansas from agricultural pumping, (2) declining groundwater levels of over 360 feet over the last 90 years in the confined middle Claiborne aquifer in southern Arkansas and northern Louisiana from municipal pumping, and (3) litigation between the State of Mississippi and a Memphis water utility over water rights in the middle Claiborne aquifer. To provide information to stakeholders addressing the groundwater-availability issues, the U.S. Geological Survey Groundwater Resources Program supported a detailed assessment of groundwater availability through the Mississippi Embayment Regional Aquifer Study (MERAS). This assessment included (1) an evaluation of how these resources have changed over time through the use of groundwater budgets, (2) development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends, and (3) application of statistical tools to evaluate the importance of individual observations within a groundwater-monitoring network. An estimated 12 million acre-feet per year (11 billion gallons per day) of groundwater was pumped in 2005 from aquifers in the Mississippi embayment. Irrigation constitutes the largest groundwater use, accounting for approximately 10 million acre-feet per year (9 billion gallons per day) in 2000 from the Mississippi

  17. Texas Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Wind-Whipped Fires in East Texas     View Larger Image ... one-year drought on record and the warmest month in Texas history. The Multi-angle Imaging SpectroRadiometer (MISR) instrument on ...

  18. Eutrophication analysis of embayments in Prince William Sound, Alaska

    SciTech Connect

    Lung, W.S.; Martin, J.L.; McCutcheon, S.C.

    1993-01-01

    Fertilizers were used in the summer of 1989 to accelerate bacterial growth in a bioremediation effort to clean up the beaches following the EXXON Valdez oil spill. Mathematical models were used to quantify the eutrophication potential in two selected embayments in Prince William Sound: Passage Cove and Snug Harbor. First, mass transport in these two embayments was determined to. Next, eutrophication models were developed for these two embayments to simulate the seasonal algal concentrations prior to fertilizer application. Finally, a series of nutrient-loading-scenarios based on different fertilizer and other chemical application rates were developed to investigate the impact. Model results and the data available indicated that the rapid exchange between embayments and the open water limits algal growth and buildup of concentrations of other chemicals applied to beaches. The exception is the potential for some ammonia toxicity at high application rates. Despite the limited data available it is clear that no significant increased algal growth would be expected following fertilizer application.

  19. SOLUTION MINING IN SALT DOMES OF THE GULF COAST EMBAYMENT

    SciTech Connect

    Griswold, G. B.

    1981-02-01

    Following a description of salt resources in the salt domes of the gulf coast embayment, mining, particularly solution mining, is described. A scenario is constructed which could lead to release of radioactive waste stored in a salt dome via inadvertent solution mining and the consequences of this scenario are analyzed.

  20. U. S. Geological Survey investigation of Mississippi Embayment area

    SciTech Connect

    Glick, E.E.

    1983-09-01

    Prior to about 1974, most of the work in the Mississippi embayment area by members of the U.S. Geological Survey was motivated by interest in the embayment's paleontologic aspects, stratigraphy, and economic resources, especially ground water. However, an excellent description of the effects of the New Madrid earthquake series was published on the centennial of that 1811-1812 seismicity. During World War II, combined efforts of the U.S. Geological Survey and the U.S. Bureau of Mines produced a wealth of information about the Little Rock pluton and the process of laterizing exposed nepheline syenite to form bauxite. That project, in a search for additional intrusive bodies at shallow depth, sponsored a reconnaissance aeromagnetic survey along the embayment edge from Little Rock, Arkansas, to Cairo, Illinois. Magnetic anomalies that were identified then are now known to be related to the series of buried plutons aligned along the northwestern margin of the upper Mississippi embayment graben. Later investigations assessed the geochemistry of the more mafic parts of the Little Rock pluton. In 1974, U.S. Geological survey effort, along with that of other federal agencies, state agencies, and academic institutions, was directed toward finding the cause of ongoing seismicity in the upper embayment and toward assessing the related potential effects on persons and property. The purpose of this poster display is to summarize the more significant findings in this area related to (a) the rock sequence, lower crust to surface; (b) the major structural features, including a rift system; (c) the current state of stress; and (d) the present-day seismicity.

  1. Basic Education in the Lower Rio Grande Valley: Human Capital Development or a Colonial System?

    ERIC Educational Resources Information Center

    Lynch, Patrick D.

    This report describes economic, social, and political characteristics of the lower Rio Grande Valley with implications for the educational system, and presents preliminary findings on how south Texas schools are integrating new immigrant Mexican students. The lower Rio Grande Valley comprises four Texas counties and northern Tamaulipas, Mexico.…

  2. Circulation patterns in open, wide and deep lacustrine embayments with different aspect ratios

    NASA Astrophysics Data System (ADS)

    Razmi, Amir Mehdi; Barry, David Andrew; Lemmin, Ulrich

    2013-04-01

    Numerical simulations were carried out to examine the effect of different horizontal aspect ratios on wind-induced circulation within open, wide and deep lacustrine embayments. Two adjacent embayments in Lake Geneva, Switzerland, located between Morges and Lausanne on the north shore of the lake, were compared. These embayments were selected because of their similar exposure with respect to wind forcing. However, their aspect ratios are different, making them ideal case studies to evaluate the impact of the aspect ratio on the resulting circulation pattern. A previously validated 3D hydrodynamic model (Delft3D-FLOW) was employed to simulate currents in the lake for the year 2010. Detailed over-lake maps of wind, temperature and humidity were used as input to drive the model. The embayments were compared in terms of circulation patterns and conditions leading to gyre formation. Furthermore, we carried out a systematic comparison, focusing on the embayment aspect ratio by constructing different "synthetic" embayments with aspect ratios in the range 1 - 4. Subsequently, the flow field within these embayments was computed for typical meteorological regimes (dominant wind regimes and seasonality). In particular, the generation of gyres was compared for different cases. The results revealed that, even for large aspect ratios (~ 3), wind-induced circulation can still occur in open, wide, and deep lacustrine embayments. The results showed that, as expected, gyres are formed less frequently as the embayment aspect ratio increases. For this reason, gyres are much more probable in the Morges embayment than in Vidy Bay.

  3. Modes and emergent time scales of embayed beach dynamics

    NASA Astrophysics Data System (ADS)

    Ratliff, Katherine M.; Murray, A. Brad

    2014-10-01

    In this study, we use a simple numerical model (the Coastline Evolution Model) to explore alongshore transport-driven shoreline dynamics within generalized embayed beaches (neglecting cross-shore effects). Using principal component analysis (PCA), we identify two primary orthogonal modes of shoreline behavior that describe shoreline variation about its unchanging mean position: the rotation mode, which has been previously identified and describes changes in the mean shoreline orientation, and a newly identified breathing mode, which represents changes in shoreline curvature. Wavelet analysis of the PCA mode time series reveals characteristic time scales of these modes (typically years to decades) that emerge within even a statistically constant white-noise wave climate (without changes in external forcing), suggesting that these time scales can arise from internal system dynamics. The time scales of both modes increase linearly with shoreface depth, suggesting that the embayed beach sediment transport dynamics exhibit a diffusive scaling.

  4. Floodplain and wetlands assessment of the White Oak Creek Embayment

    SciTech Connect

    Not Available

    1991-07-01

    This report describes the proposed methods for dealing with contaminants that have accumulated in White Oak Creek, White Oak Lake, and the White Oak Creek Embayment as a result of process releases and discharges from the Oak Ridge National Laboratory. Alternative methods of cleaning up the area which were considered in accordance with regulatory guidelines are listed, and information supporting the selected methods is provided. Also included are results of a site survey conducted at the White Oak Creek Embayment and the expected effects of the proposed control structures on the floodplain and wetlands. The appendix contains figures showing the nine cross-sections of the stream channel surveyed during studies of the White Oak Creek area.

  5. A Model for Health Professional Education in South Texas

    ERIC Educational Resources Information Center

    Ramirez, Amelie; Vela, Leonel; Cigarroa, Francisco G.

    2008-01-01

    In 1997, The University of Texas Health Science Center at San Antonio established the Regional Academic Health Center (RAHC) for the Lower Rio Grande Valley in south Texas. Through medical education programs, research facilities, and partnerships with health-care providers, the RAHC aims to improve the health status and access to health services…

  6. 7 CFR 906.365 - Texas Orange and Grapefruit Regulation 34.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Texas Orange and Grapefruit Regulation 34. 906.365... ORANGES AND GRAPEFRUIT GROWN IN LOWER RIO GRANDE VALLEY IN TEXAS Container and Pack Requirements § 906.365 Texas Orange and Grapefruit Regulation 34. (a) No handler shall handle any variety of oranges...

  7. 7 CFR 906.365 - Texas Orange and Grapefruit Regulation 34.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Texas Orange and Grapefruit Regulation 34. 906.365... ORANGES AND GRAPEFRUIT GROWN IN LOWER RIO GRANDE VALLEY IN TEXAS Container and Pack Requirements § 906.365 Texas Orange and Grapefruit Regulation 34. (a) No handler shall handle any variety of oranges...

  8. 7 CFR 906.365 - Texas Orange and Grapefruit Regulation 34.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Texas Orange and Grapefruit Regulation 34. 906.365... ORANGES AND GRAPEFRUIT GROWN IN LOWER RIO GRANDE VALLEY IN TEXAS Container and Pack Requirements § 906.365 Texas Orange and Grapefruit Regulation 34. (a) No handler shall handle any variety of oranges...

  9. 7 CFR 906.365 - Texas Orange and Grapefruit Regulation 34.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Texas Orange and Grapefruit Regulation 34. 906.365... ORANGES AND GRAPEFRUIT GROWN IN LOWER RIO GRANDE VALLEY IN TEXAS Container and Pack Requirements § 906.365 Texas Orange and Grapefruit Regulation 34. (a) No handler shall handle any variety of oranges...

  10. Seismotectonic implications of sand blows in the southern Mississippi Embayment

    USGS Publications Warehouse

    Cox, R.T.; Hill, A.A.; Larsen, D.; Holzer, T.; Forman, S.L.; Noce, T.; Gardner, C.; Morat, J.

    2007-01-01

    We explore seismically-induced sand blows from the southern Mississippi Embayment and their implications in resolving the question of near or distal epicentral source region. This was accomplished using aerial photography, field excavations, and cone penetration tests. Our analysis shows that three sand blow fields exhibit a distinct chronology of strong ground motion for the southern embayment: (1) The Ashley County, Arkansas sand blow field, near the Arkansas/Louisiana state border, experienced four Holocene sand venting episodes; (2) to the north, the Desha County field experienced at least three episodes of liquefaction; and (3) the Lincoln-Jefferson Counties field experienced at least one episode. Cone penetration tests (CPT) conducted in and between the sand blow fields suggest that the fields may not be distal liquefaction associated with New Madrid seismic zone earthquakes but rather are likely associated with strong earthquakes on local faults. This conclusion is consistent with the differences in timing of the southern embayment sand venting episodes and those in the New Madrid seismic zone. These results suggest that active tectonism and strong seismicity in intraplate North America may not be localized at isolated weak spots, but rather widespread on fault systems that are favorably oriented for slip in the contemporary stress field. ?? 2006 Elsevier B.V. All rights reserved.

  11. Gyre formation within embayments of a large lake (Lake Geneva, Switzerland)

    NASA Astrophysics Data System (ADS)

    Razmi, A.; Barry, D.; Bouffard, D.; Le Dantec, N.; Lemmin, U.; Wuest, A.

    2013-12-01

    Numerical simulations were carried out to examine gyre formation within open, wide lacustrine embayments. The present study was motivated by observed differences in gyre formation within two open and wide embayments (located at Vidy and Morges in Lake Geneva, Switzerland). These two embayments are located within about 3 km of each other on the northern shore of Lake Geneva, and are subjected to similar pelagic currents. Vidy is deeper and has a greater aspect ratio than Morges. The flow field in the embayments was modeled using a previously validated 3D hydrodynamic model (Delft3D-FLOW). The model solved the Reynolds-Averaged Navier-Stokes equations, combined with a k-ɛ turbulence closure in σ (lakebed-following) coordinates. Our study focused on the influence of the embayment geometry on the (uniform) longshore (pelagic) current, specifically the occurrence and magnitude of circulation within the embayment. We built a set of numerical experiments using synthetic embayments, and systematically examined embayment geometry, thereby capturing the differences between the Vidy and Morges embayments. The numerical experiments considered single rectilinear embayments with different aspect ratios (i.e., 1-6), depth, shore-parallel flow rates, and embayment corner angle between 0°-50°. The circulation magnitude changes abruptly for an angle of about 40°. Embayments with angles greater than 40° have much greater circulation then those with lesser angles, other factors remaining the same. Of the factors considered (i.e., aspect ratio, offshore current velocity, corner angle, bottom slope, and viscosity), bottom slope and the viscosity have almost no impact on embayment circulation. For uniform offshore current patterns, gyres form in embayments with large aspect ratios (up to ~3). For the Vidy and Morges embayments, the results showed that gyre formation is more likely in Morges due to its smaller aspect ratio, a finding that is supported by field data gathered in

  12. Nutrient budgets for large Chinese estuaries and embayment

    NASA Astrophysics Data System (ADS)

    Liu, S. M.; Hong, G.-H.; Ye, X. W.; Zhang, J.; Jiang, X. L.

    2009-01-01

    Nutrient concentrations among the Chinese rivers and bays vary 10-75 fold depending on nutrient elements. The silicic acid levels in South China rivers are higher than those from North China rivers and the yields of dissolved silicate increased from the north to the south of China, indicating the effect of climate on weathering. The nutrient levels in Chinese rivers are higher than those from the large and less-disturbed world rivers such as Amazon and Zaire, but comparable to the values for European and North American polluted and eutrophic rivers like the Loire and Po. This may be ascribed to both of extensive leaching and influences from agricultural and domestic activities over the drainage basins of Chinese rivers. DIN:PO3-4 ratios in most of Chinese rivers and bays are higher (up to 2800) than the other rivers in the world. The atomic ratios of DIN to PO43- in the major Chinese rivers and embayment decrease in exponential trend with increase in the atomic ratios of PO43- to Si(OH)4, indicating that primary production in coastal environments changes with the nutrients transport when the urbanization develops to a certain extent, and the potential limited nutrient elements can be changed from phosphorus to nitrogen limitation, which can modify aquatic food webs and then the ocean ecosystem. A simple steady-state mass-balance box model was employed. The output shows that the estuaries and embayment behave as a sink or source of nutrients. For the major Chinese estuaries, both residual and mixing flow transport nutrients off the estuaries, and nutrient transport fluxes in summer is 3-4 fold that in winter except comparable for NH4+. These fluxes are 1.0-1.7 fold that estimated by timing riverine nutrient concentrations and freshwater discharge. For the major Chinese embayment, nutrient elements are transported to China Seas except PO43- and Si(OH)4 in Sanggou Bay and Jiaozhou Bay. Seasonally, nutrients transport fluxes off the bays in the summer are 2.2-7.0 fold

  13. Upper Mississippi embayment shallow seismic velocities measured in situ

    USGS Publications Warehouse

    Liu, Huaibao P.; Hu, Y.; Dorman, J.; Chang, T.-S.; Chiu, J.-M.

    1997-01-01

    Vertical seismic compressional- and shear-wave (P- and S-wave) profiles were collected from three shallow boreholes in sediment of the upper Mississippi embayment. The site of the 60-m hole at Shelby Forest, Tennessee, is on bluffs forming the eastern edge of the Mississippi alluvial plain. The bluffs are composed of Pleistocene loess, Pliocene-Pleistocene alluvial clay and sand deposits, and Tertiary deltaic-marine sediment. The 36-m hole at Marked Tree, Arkansas, and the 27-m hole at Risco, Missouri, are in Holocene Mississippi river floodplain sand, silt, and gravel deposits. At each site, impulsive P- and S-waves were generated by man-made sources at the surface while a three-component geophone was locked downhole at 0.91-m intervals. Consistent with their very similar geology, the two floodplain locations have nearly identical S-wave velocity (VS) profiles. The lowest VS values are about 130 m s-1, and the highest values are about 300 m s-1 at these sites. The shear-wave velocity profile at Shelby Forest is very similar within the Pleistocene loess (12m thick); in deeper, older material, VS exceeds 400 m s-1. At Marked Tree, and at Risco, the compressional-wave velocity (VP) values above the water table are as low as about 230 m s-1, and rise to about 1.9 km s-1 below the water table. At Shelby Forest, VP values in the unsaturated loess are as low as 302 m s-1. VP values below the water table are about 1.8 km s-1. For the two floodplain sites, the VP/VS ratio increases rapidly across the water table depth. For the Shelby Forest site, the largest increase in the VP/VS ratio occurs at ???20-m depth, the boundary between the Pliocene-Pleistocene clay and sand deposits and the Eocene shallow-marine clay and silt deposits. Until recently, seismic velocity data for the embayment basin came from earthquake studies, crustal-scale seismic refraction and reflection profiles, sonic logs, and from analysis of dispersed earthquake surface waves. Since 1991, seismic data

  14. Embayed intermediate volcanoes on Venus: constraints on the evolution of the volcanic plains.

    NASA Astrophysics Data System (ADS)

    López, I.

    2007-08-01

    Volcanoes on Venus are divided into three classes based on diameter (e.g. Crumpler et al., 1997): 1) large volcanoes (>=100 km); intermediate volcanoes (>=20 km and < 100 km; and 3) small volcanoes (< 20 km). Some authors (Guest and Stofan, 1999; Crumpler et al., 1997) propose that some intermediate volcanoes could be indeed large volcanoes with embayed flow aprons. We analyze the global population of embayed intermediate-size volcanoes and compare their summits with edifices classified as large volcanoes. We define an intermediate-size volcano as embayed when: 1) we observe flows from another source that clearly overlap the volcano slopes, and 2) we observe intermediate-size volcanoes with their summits presenting scarps related to flank-failure processes but with the products of the modification (i.e. collapse deposits) embayed. As result of the survey more than 100 embayed intermediate-size volcanoes have been catalogued and integrated into a Geographic Information System. Many if not most of these volcanoes have summit characteristics similar to other large volcanoes and therefore could indeed be large volcanoes with their flow aprons embayed. Large volcanoes on Venus (~165 catalogued features) have been traditionally considered to represent a late type of activity on the evolution of the volcanic plains (e.g. Price and Suppe, 1994). If a representative fraction of the observed intermediate-size embayed volcanoes are indeed embayed large volcanoes the stratigraphic significance of large volcanoes on the evolution of the plains should be reevaluated.

  15. Impact of the arundo wasp, Tetramesa romana (Hymenoptera:Eurytomidae) on biomass of the invasive weed, Arundo donax (Poaceae:Arundinoideae) and on revegetation of riparian habitat along the Rio Grande in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An invasive grass, Arundo donax, occupies thousands of hectares of arid riparian habitat along the Rio Grande and was the first perennial grass to be targeted with biological control, due to the great negative impacts of this weed on water resources and riparian ecosystems. The shoot-tip galling was...

  16. Assessing the extreme overwash regime along an embayed urban beach

    NASA Astrophysics Data System (ADS)

    Silveira, Tanya M.; Taborda, Rui; Carapuço, Mafalda M.; Andrade, César; Freitas, Maria C.; Duarte, João F.; Psuty, Norbert P.

    2016-12-01

    Coastal overwash is one of the most important hazards affecting the coastal zone and therefore has been the focus of several studies related to the establishment of setback lines. However, studies of extreme overwash (EO) events along urban beaches backed by a seawall or structure are scarce, and reveal the difficulties associated with its assessment, measurement and validation. The Nazaré coastal urban area (located on the west coast of Portugal) is developed adjacent to an embayed reflective beach and is subject to frequent and localized inundation due to EO events capable of overtopping the protection seawall. The current work develops a methodological approach to simulate total water levels (TWL) and seawall overtopping occurrences in time and space, with the ultimate goal of identifying the factors that govern the extreme overwash regime. The method uses multi-decadal time series of site-specific wave and tide, and high-resolution topo-bathymetric data, and recreates the TWL time series for a 36-year period. The model is successfully validated against video imagery and maximum swash line data that provide information on the reach of the water levels measured during modal and extreme TWL conditions along the studied beach. This study establishes the importance of the interaction of the modal and extreme hydrodynamic processes with the beach and backshore morphology. The Nazaré embayment is in equilibrium with the alongshore-varying modal wave conditions, resulting in higher vulnerability of the most sheltered sector during extreme events.

  17. Post-Cretaceous faulting at head of Mississippi embayment

    SciTech Connect

    Nelson, W.J. ); Harrison, R.W. )

    1993-03-01

    Recent mapping in southernmost Illinois and southeastern Missouri has revealed numerous faults that displace Cretaceous and Tertiary strata. Units as young as the Pliocene-Pleistocene( ) Mounds Gravel are deformed; some faults possibly displace Quaternary sediments. The faults strike northeast, dip nearly vertically, and exhibit characteristics of dextral strike-slip. Pull-apart grabens occur along right-stepping fault strands, they contain chaotically jumbled blocks of Paleozoic, Cretaceous and Tertiary rocks downdropped as much as 800 m relative to wall rocks. Faults at the head of the Mississippi embayment probably originated during Cambrian rifting (Reelfoot rift) and have a long, complex history of reactivation under different stress fields. Some faults are on strike with faults in the New Madrid seismic zone. Kinematics of post-Cretaceous displacements fit the contemporary stress regime of ENE-WSW compression. Similar fault orientations and kinematics, as well as close proximity, suggest a close link between faulting at the head of the embayment and ongoing tectonism in the New Madrid seismic zone.

  18. Seismic Noise Characterization in the Northern Mississippi Embayment

    NASA Astrophysics Data System (ADS)

    Wiley, S.; Deshon, H. R.; Boyd, O. S.

    2009-12-01

    We present a study of seismic noise sources present within the northern Mississippi embayment near the New Madrid Seismic Zone (NMSZ). The northern embayment contains up to 1 km of unconsolidated coastal plain sediments overlying bedrock, making it an inherently noisy environment for seismic stations. The area is known to display high levels of cultural noise caused by agricultural activity, passing cars, trains, etc. We characterize continuous broadband seismic noise data recorded for the months of March through June 2009 at six stations operated by the Cooperative New Madrid Seismic Network. We looked at a single horizontal component of data during nighttime hours, defined as 6:15PM to 5:45AM Central Standard Time, which we determined to be the lowest amplitude period of noise for the region. Hourly median amplitudes were compared to daily average wind speeds downloaded from the National Oceanic and Atmospheric Administration. We find a correlation between time periods of increased noise and days with high wind speeds, suggesting that wind is likely a prevalent source of seismic noise in the area. The effects of wind on seismic recordings may result from wind induced tree root movement which causes ground motion to be recorded at the vaults located ~3m below ground. Automated studies utilizing the local network or the EarthScope Transportable Array, scheduled to arrive in the area in 2010-11, should expect to encounter wind induced noise fluctuations and must account for this in their analysis.

  19. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; summary and analysis of water-quality data for the basic-fixed-site network, 1993-95

    USGS Publications Warehouse

    Healy, D.F.

    1997-01-01

    The Rio Grande Valley study unit of the U.S. Geological Survey National Water-Quality Assessment Program collected monthly water- quality samples at a network of surface-water sites from April 1993 through September 1995. This basic-fixed-site network consisted of nine main-stem sites on the Rio Grande, five sites on tributaries of the Rio Grande, two sites on streams in the Rio Grande Valley study unit that are not directly tributary to the Rio Grande, and one site on a conveyance channel. During each monthly sampling, field properties were measured and samples were collected for the analysis of dissolved solids, major constituents, nutrients, selected trace elements, and suspended-sediment concentrations. During selected samplings, supplemental samples were collected for the analysis of additional trace elements, organic carbon, and/or pesticides. Spatial variations of dissolved-solids, major-constituent, and nutrient data were analyzed. The report presents summary statistics for the monthly water-quality data by sampling site and background information on the drainage basin upstream from each site. Regression equations are presented that relate dissolved-solids, major-constituent, and nutrient concentrations to streamflow, selected field properties, and time. Median instantaneous streamflow at each basic-fixed site ranged from 1.4 to 1,380 cubic feet per second. Median specific conductance at each basic-fixed site ranged from 84 to 1,680 microsiemens per centimeter at 25 degrees Celsius, and median pH values ranged from 7.8 to 8.5. The water sampled at the basic-fixed sites generally was well oxygenated and had a median dissolved-oxygen percent of saturation range from 89 to 108. With the exception of Rio Grande above mouth of Trinchera Creek, near Lasauses, Colorado, dissolved-solids concentrations in the main stem of the Rio Grande generally increased in a downstream direction. This increase is from natural sources such as ground-water inflow and

  20. Coliform contamination of a coastal embayment: Sources and transport pathways

    USGS Publications Warehouse

    Weiskel, P.K.; Howes, B.L.; Heufelder, G.R.

    1996-01-01

    Fecal bacterial contamination of nearshore waters has direct economic impacts to coastal communities through the loss of shellfisheries and restrictions of recreational uses. We conducted seasonal measurements of fecal coliform (FC) sources and transport pathways contributing to FC contamination of Buttermilk Bay, a shallow embayment adjacent to Buzzards Bay, MA. Typical of most coastal embayments, there were no direct sewage discharges (i.e., outfalls), and fecal bacteria from human, domestic animal, and wildlife pools entered open waters primarily through direct deposition or after transport through surface waters or groundwaters. Direct fecal coliform inputs to bay waters occurred primarily in winter (December-March) from waterfowl, ~33 x 1012 FC yr-1 or ~67% of the total annual loading. Effects of waterfowl inputs on bay FC densities were mitigated by their seasonality, wide distribution across the bay surface, and the apparent limited dispersal from fecal pellets. On-site disposal of sewage by septic systems was the single largest FC source in the watershed-embayment system, 460 x 1012 FC yr-1, but due to attenuation during subsurface transport only a minute fraction, < 0.006 x 1012 FC yr-1, reached bay waters (<0.01% of annual input to bay). Instead, surface water flows, via storm drains and natural streams under both wet- and dry-weather conditions, contributed the major terrestrial input, 12 x 1012 FC yr-1 (24% of annual input), all from animal sources. Since most of the surface water FC inputs were associated with periodic, short-duration rain events with discharge concentrated in nearshore zones, wet-weather flows were found to have a disproportionately high impact on nearshore FC levels. Elution of FC from shoreline deposits of decaying vegetation (wrack) comprised an additional coliform source. Both laboratory and field experiments suggest significant elution of bacteria from wrack, ~3 x 1012 FC yr-1 on a bay-wide basis (6% of annual input), primarily

  1. Nearshore hydrodynamics as loading and forcing factors for Escherichia coli contamination at an embayed beach

    USGS Publications Warehouse

    Ge, Zhongfu; Whitman, Richard L.; Nevers, Meredith B.; Phanikumar, Mantha S.; Byappanahalli, Muruleedhara N.

    2012-01-01

    Numerical simulations of the transport and fate of Escherichia coli were conducted at Chicago’s 63rd Street Beach, an embayed beach that had the highest mean E. coli concentration among 23 similar Lake Michigan beaches during summer months of 2000-2005, in order to find the cause for the high bacterial contamination. The numerical model was based on the transport of E. coli by current circulation patterns in the embayment driven by longshore main currents and the loss of E. coli in the water column, taking settling as well as bacterial dark- and solar-related decay into account. Two E. coli loading scenarios were considered: one from the open boundary north of the embayment and the other from the shallow water near the beachfront. Simulations showed that the embayed beach behaves as a sink for E. coli in that it generally receives E. coli more efficiently than it releases them. This is a result of the significantly different hydrodynamic forcing factors between the inside of the embayment and the main coastal flow outside. The settled E. coli inside the embayment can be a potential source of contamination during subsequent sediment resuspension events, suggesting that deposition-resuspension cycles of E. coli have resulted in excessive bacterial contamination of beach water. A further hypothetical case with a breakwater shortened to half its original length, which was anticipated to enhance the current circulation in the embayment, showed a reduction in E. coli concentrations of nearly 20%.

  2. Nearshore hydrodynamics as loading and forcing factors for Escherichia coli contamination at an embayed beach

    USGS Publications Warehouse

    Ge, Zhongfu; Whitman, Richard L.; Nevers, Meredith B.; Phanikumar, Mantha S.; Byappanahalli, Muruleedhara N.

    2012-01-01

    Numerical simulations of the transport and fate of Escherichia coli were conducted at Chicago's 63rd Street Beach, an embayed beach that had the highest mean E. coli concentration among 23 similar Lake Michigan beaches during summer months of 2000-2005, in order to find the cause for the high bacterial contamination. The numerical model was based on the transport of E. coli by current circulation patterns in the embayment driven by longshore main currents and the loss of E. coli in the water column, taking settling as well as bacterial dark- and solar-related decay into account. Two E. coli loading scenarios were considered: one from the open boundary north of the embayment and the other from the shallow water near the beachfront. Simulations showed that the embayed beach behaves as a sink for E. coli in that it generally receives E. coli more efficiently than it releases them. This is a result of the significantly different hydrodynamic forcing factors between the inside of the embayment and the main coastal flow outside. The settled E. coli inside the embayment can be a potential source of contamination during subsequent sediment resuspension events, suggesting that deposition-resuspension cycles of E. coli have resulted in excessive bacterial contamination of beach water. A further hypothetical case with a breakwater shortened to half its original length, which was anticipated to enhance the current circulation in the embayment, showed a reduction in E. coli concentrations of nearly 20%.

  3. Genetic and grade and tonnage models for sandstone-hosted roll-type uranium deposits, Texas Coastal Plain, USA

    USGS Publications Warehouse

    Hall, Susan M.; Mihalasky, Mark J.; Tureck, Kathleen; Hammarstrom, Jane M.; Hannon, Mark

    2017-01-01

    with either (1) organic-rich debris adjacent to large long-lived fluvial channels and barrier–bar sequences or (2) extrinsic reductants entrained in formation water or discrete gas that migrated into host units via faults and along the flanks of salt domes and shale diapirs. The southwestern portion of the region, the Rio Grande embayment, contains all the necessary factors required for roll-type uranium deposits. However, the eastern portion of the region, the Houston embayment, is challenged by a humid environment and a lack of source rock and transmissive units, which may combine to preclude the deposition of economic deposits. A grade and tonnage model for the Texas Coastal Plain shows that the Texas deposits represent a lower tonnage subset of roll-type deposits that occur around the world, and required aggregation of production centers into deposits based on geologic interpretation for the purpose of conducting a quantitative mineral resource assessment.

  4. DRAFT LANDSAT DATA MOSAIC: MONTGOMERY COUNTY, TEXAS; HARRIS COUNTY, TEXAS; FORT BEND COUNTY, TEXAS; BRAZORIA COUNTY, TEXAS; GALVESTON COUNTY, TEXAS

    EPA Science Inventory

    This is a draft Landsat Data Mosaic, which contains remote sensing information for Montgomery County, Texas Harris County, Texas Fort Bend County, Texas Brazoria County, Texas Galveston County, and Texas Imagery dates on the following dates: October 6, 1999 and September 29, 200...

  5. Texas Heart Institute

    MedlinePlus

    ... Texas Heart Institute, The University of Texas Health Science Center at Houston, MD Anderson Cancer Center, and The University of Houston. Held most ... for Physicians Fellowships & Residencies School ...

  6. Maps of upper Mississippi embayment Paleozoic and Precambrian rocks

    USGS Publications Warehouse

    Dart, Richard L.

    1995-01-01

    The Mississippi Embayment regional seismic hazard (Fuller, 1912; Nuttli, 1973, 1982, 1983), associated with the New Madrid seismic zone (NMSZ) is attributed to displacement on seismogenic structures primarily within the failed Reelfoot rift (Burke and Dewey, 1973; Ervin and McGinnis, 1975; Hildenbrand, 1977; Johnston and Shedlock, 1992). Hildenbrand and others (1977) and Hildenbrand (1985) used potential field data to show the northeast trend of the buried rift and the existence of related intrusive bodies. The Mississippi Valley graben (Hildenbrand and others, 1977; Kane and others, 1981; Hildenbrand, 1985; Wheeler and others, 1993), also referred to as the Reelfoot graben (Hildenbrand and Hendricks, 1995), is here considered to be the structural expression of the Reelfoot rift at the Precambrian basement surface.

  7. Water quality monitoring report for the White Oak Creek Embayment

    SciTech Connect

    Ford, C.J. ); Wefer, M.T. )

    1993-01-01

    Water quality monitoring activities that focused on the detection of resuspended sediments in the Clinch River were conducted in conjunction with the White Oak Creek Embayment (WOCE) time-critical Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to construct a sediment-retention structure at the mouth of White Oak Creek (WOC). Samples were collected by use of a 24-h composite sampler and through real-time water grab sampling of sediment plumes generated by the construction activities. Sampling stations were established both at the WOC mouth, immediately adjacent to the construction site, and at K-1513, the Oak Ridge K-25 Site drinking water intake approximately 9.6 km downstream in the Clinch River. Results are described.

  8. Loss of native rocky reef biodiversity in Australian metropolitan embayments.

    PubMed

    Stuart-Smith, Rick D; Edgar, Graham J; Stuart-Smith, Jemina F; Barrett, Neville S; Fowles, Amelia E; Hill, Nicole A; Cooper, Antonia T; Myers, Andrew P; Oh, Elizabeth S; Pocklington, Jacqui B; Thomson, Russell J

    2015-06-15

    Urbanisation of the coastal zone represents a key threat to marine biodiversity, including rocky reef communities which often possess disproportionate ecological, recreational and commercial importance. The nature and magnitude of local urban impacts on reef biodiversity near three Australian capital cities were quantified using visual census methods. The most impacted reefs in urbanised embayments were consistently characterised by smaller, faster growing species, reduced fish biomass and richness, and reduced mobile invertebrate abundance and richness. Reef faunal distribution varied significantly with heavy metals, local population density, and proximity to city ports, while native fish and invertebrate communities were most depauperate in locations where invasive species were abundant. Our study adds impetus for improved urban planning and pollution management practises, while also highlighting the potential for skilled volunteers to improve the tracking of changes in marine biodiversity values and the effectiveness of management intervention.

  9. Explosion source strong ground motions in the Mississippi embayment

    USGS Publications Warehouse

    Langston, C.A.; Bodin, P.; Powell, C.; Withers, M.; Horton, S.; Mooney, W.

    2006-01-01

    Two strong-motion arrays were deployed for the October 2002 Embayment Seismic Excitation Experiment to study the spatial variation of strong ground motions in the deep, unconsolidated sediments of the Mississippi embayment because there are no comparable strong-motion data from natural earthquakes in the area. Each linear array consisted of eight three-component K2 accelerographs spaced 15 m apart situated 1.2 and 2.5 kin from 2268-kg and 1134-kg borehole explosion sources, respectively. The array data show distinct body-wave and surface-wave arrivals that propagate within the thick, unconsolidated sedimentary column, the high-velocity basement rocks, and small-scale structure near the surface. Time-domain coherence of body-wave and surface-wave arrivals is computed for acceleration, velocity, and displacement time windows. Coherence is high for relatively low-frequency verticalcomponent Rayleigh waves and high-frequency P waves propagating across the array. Prominent high-frequency PS conversions seen on radial components, a proxy for the direct S wave from earthquake sources, lose coherence quickly over the 105-m length of the array. Transverse component signals are least coherent for any ground motion and appear to be highly scattered. Horizontal phase velocity is computed by using the ratio of particle velocity to estimates of the strain based on a plane-wave-propagation model. The resulting time-dependent phase-velocity map is a useful way to infer the propagation mechanisms of individual seismic phases and time windows of three-component waveforms. Displacement gradient analysis is a complementary technique for processing general spatial-array data to obtain horizontal slowness information.

  10. Sedimentation processes in a coral reef embayment: Hanalei Bay, Kauai

    USGS Publications Warehouse

    Storlazzi, C.D.; Field, M.E.; Bothner, Michael H.; Presto, M.K.; Draut, A.E.

    2009-01-01

    Oceanographic measurements and sediment samples were collected during the summer of 2006 as part of a multi-year study of coastal circulation and the fate of terrigenous sediment on coral reefs in Hanalei Bay, Kauai. The goal of this study was to better understand sediment dynamics in a coral reef-lined embayment where winds, ocean surface waves, and river floods are important processes. During a summer period that was marked by two wave events and one river flood, we documented significant differences in sediment trap collection rates and the composition, grain size, and magnitude of sediment transported in the bay. Sediment trap collection rates were well correlated with combined wave-current near-bed shear stresses during the non-flood periods but were not correlated during the flood. The flood's delivery of fine-grained sediment to the bay initially caused high turbidity and sediment collection rates off the river mouth but the plume dispersed relatively quickly. Over the next month, the flood deposit was reworked by mild waves and currents and the fine-grained terrestrial sediment was advected around the bay and collected in sediment traps away from the river mouth, long after the turbid surface plume was gone. The reworked flood deposits, due to their longer duration of influence and proximity to the seabed, appear to pose a greater long-term impact to benthic coral reef communities than the flood plumes themselves. The results presented here display how spatial and temporal differences in hydrodynamic processes, which result from variations in reef morphology and orientation, cause substantial variations in the deposition, residence time, resuspension, and advection of both reef-derived and fluvial sediment over relatively short spatial scales in a coral reef embayment.

  11. Rip spacing and persistence on an embayed beach

    NASA Astrophysics Data System (ADS)

    Holman, R. A.; Symonds, G.; Thornton, E. B.; Ranasinghe, R.

    2006-01-01

    Four years of daily time exposure images from an embayed beach were examined to study the spacing, persistence, and location preferences of rips in a natural rip channel system. A total of 5271 rip channels was observed on 782 days. Occurrence statistics showed no evidence of the preferred location pattern associated with standing edge waves trapped in an embayed beach. The histogram of rip spacing, the primary diagnostic observable for most models, was well modeled by a lognormal distribution (mean spacing of 178 m). However, spacings were highly longshore variable (time mean of the standard deviation/longshore mean of rip spacing was 39%), so they are of questionable merit as a diagnostic variable. Storm-driven resets to the longshore uniform condition required by most models occurred only four times per year on average, making rip generation models relevant to only a small fraction of the system behavior. Rip spacings after the 15 observed reset events were uncorrelated with bar crest distance. The lifetime of the 324 individual rip channel trajectories averaged 45.6 days. Rips were equally mobile in both longshore directions, but the coefficient of variation of rip migration rates was large, even for high migration rates. The mean migration rate was well correlated to a proxy for the longshore current (R2 of 0.78). Thus there is no significant evidence that the formation, spacing, and migration of rip channels on this beach can be explained by currently existing simple models. Moreover, the alongshore uniform initial conditions assumed by these models are rare on Palm Beach, making the models generally inapplicable.

  12. The responses of artificial embayed beaches to storm events

    NASA Astrophysics Data System (ADS)

    Ojeda, E.; Guillén, J.; Ribas, F.

    2009-09-01

    The plan-view and the profile shape of sandy beaches largely depend on the incoming wave-energy (Wright and Short, 1984). In this sense, storm events are responsible for major changes in the configuration of sandy beaches and the cumulative effect of storms and fair-weather conditions determines the morphodynamic state of a certain beach. With increasing wave energy, the beach will change from the Reflective state to the Low Tide Terrace, Transverse Bar and Rip, Rhythmic Bar and Beach, Longshore Bar and Trough and finally to the Dissipative beach state. These morphodynamic states are also observed at artificial embayed beaches, although artificial groins limit alongshore sediment transport and protect sections of the beach from waves approaching from a range of directions (Short and Masselink, 1999). This contribution focuses on the morphological changes of the shoreline and the submerged sandbars of artificial embayed (sandy) beaches due to the effect of high-wave conditions associated to storms. We characterize the morphological response of the emerged and submerged beach profile of two of the artificial embayed beaches of the Barcelona city coast (NW Mediterranean). The two embayed beaches under study are single-barred beaches subject to the same climatic conditions but with different morphological characteristics. The study comprises more than 4 years of data, from November 2001 to March 2006, obtained through an Argus video system (Holman and Stanley, 2007). The extraction of the shoreline and barline locations is accomplished using 10-minute time-exposure video images. Shorelines were extracted directly from oblique images (see Ojeda and Guillén, [2008] for a complete description) and rectified afterwards. Sandbars were inferred from the rectified time-exposure video images based on the preferential wave breaking over shallow areas, so they required a minimum significant wave height (Hs) which allowed the occurrence of a clear wave-breaking pattern. The

  13. Grand River/Grand Rapids (Michigan)

    EPA Pesticide Factsheets

    Grand River/Grand Rapids (Michigan) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts

  14. PECONIC ESTUARY: AN ASSESSMENT OF SHELLFISH RESOURCES IN THE TRIBUTARIES AND EMBAYMENTS OF THE PECONIC ESTUARY

    EPA Science Inventory

    Executive Summary Historically, the Peconic Estuary's shellfish resources have supported significant fisheries for a number of species including hard clams, oysters and bay scallops. However, distribution and abundance data for the tributaries and embayments within the Peconic Es...

  15. Floods on small streams in Texas

    USGS Publications Warehouse

    Ruggles, Frederick H.

    1966-01-01

    The first streamflow station in Texas was established on the Rio Grande at El Paso on May 10, 1889. Sip,ce that time the systematic collection of streamflow data. has expanded. In 1915 the Texas Board of Water Engineers (now the Texas Water Development Board) entered into a cooperative agreement with the U. S. Geological Survey for the purpose of expanding the network of stream-gaging stations in Texas. Sites were selected for stream-gaging stations to obtain hydrologic data for water supply and flood control. Therefore, the stream-gaging stations were located principally on major streams. Today, after three-quarters of a century.of hydrologic data collection, peak discharge data on small streams are still deficient in Texas. The Geological Survey and the Texas Highway Department, therefore, have entered into a cooperative program to collect peak discharge data on small streams for the purpose of deriving flood-frequency data needed for the economical design of culverts and small bridges.

  16. Equilibrium bed profiles in an idealized two-inlet embayment

    NASA Astrophysics Data System (ADS)

    Salles, Paulo; Meerman, Corine; Schuttelaars, Henk

    2015-04-01

    Multiple inlet systems are present at many coasts worldwide, often in coastal areas with high ecological and/or economical value (e.g., Wadden Sea, Venice Lagoon, Terminos Lagoon, etc). These coastal systems are highly dynamic, and their equilibrium is fragile. The stability depends mainly on the sediment dynamics at the inlet and inside the embayment, as well as numerous other factors and processes, such as inlet and embayment geometries, sediment properties, sediment availability, tidal and wave forcing, wind, fresh water input, and human interventions. It also depends on the presence of watersheds inside the system that can generate subembayments during some periods of the tidal cycle or longer timescales (e.g., dry season), and consequently modify the residual circulation and transport, which in turn can affect the long-term stability. This study focuses particularly on the equilibrium bed profile in a two-inlet system, as a function of varying conditions (inlet depth, basin length, tidal amplitude and nonlinearity). In order to address this, an idealized cross-sectionally averaged semi-analytical model was developed, in which only the essential physical processes are taken into account. The basin is assumed to be short (compared to the wavelength) and shallow, and the width may vary in the along-channel direction. The water motion is described by the depth averaged shallow water equations. The model is forced at each inlet with a mean surface elevation, a prescribed semidiurnal signal (M2) and its first overtide (M4), and the depths at the entrances are prescribed. The sediment transport is described by a depth integrated advection-diffusion equation, and the bed evolves due to the divergence of tidally-averaged bedload and suspended load fluxes. Model results of equilibrium bottom profiles suggest that morphodynamic equilibria can be found in such two-inlet systems. The observed equilibrium profiles show the formation of watersheds, with its location and

  17. Using airborne hyperspectral imagery for mapping saltcedar infestations in west Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rio Grande of west Texas contains, by far, the largest infestation of saltcedar (Tamarix spp.) in Texas. The objective of this study was to evaluate airborne hyperspectral imagery and different classification techniques for mapping saltcedar infestations. Hyperspectral imagery with 102 usable ba...

  18. Evaluating airborne hyperspectral imagery for mapping saltcedar infestations in west Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rio Grande of west Texas contains by far the largest infestation of saltcedar (Tamarix spp.) in Texas. The objective of this study was to evaluate airborne hyperspectral imagery and different classification techniques for mapping saltcedar infestations. Hyperspectral imagery with 102 usable band...

  19. 75 FR 7625 - Endangered and Threatened Wildlife and Plants; Rio Grande Silvery Minnow (Hybognathus amarus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-22

    ... (mi)) reach of the Rio Grande River in New Mexico, downstream of Cochiti Dam to the headwaters of Elephant Butte Reservoir. In December 2008, silvery minnows were introduced into the Rio Grande River near Big Bend, Texas, as a nonessential, experimental population under section 10(j) of the ESA (December...

  20. 46 CFR 7.105 - Marquesas Keys, FL to Rio Grande, TX.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Marquesas Keys, FL to Rio Grande, TX. 7.105 Section 7.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY... the seaward limits of the territorial sea (as defined in 33 CFR 2.22(a)(1)) to Rio Grande, Texas...

  1. 46 CFR 7.105 - Marquesas Keys, FL to Rio Grande, TX.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Marquesas Keys, FL to Rio Grande, TX. 7.105 Section 7.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY... the seaward limits of the territorial sea (as defined in 33 CFR 2.22(a)(1)) to Rio Grande, Texas...

  2. 46 CFR 7.105 - Marquesas Keys, FL to Rio Grande, TX.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Marquesas Keys, FL to Rio Grande, TX. 7.105 Section 7.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY... the seaward limits of the territorial sea (as defined in 33 CFR 2.22(a)(1)) to Rio Grande, Texas...

  3. White Oak Creek Embayment site characterization and contaminant screening analysis

    SciTech Connect

    Blaylock, B.G.; Ford, C.J.; Frank, M.L.; Hoffman, F.O.; Hook, L.A.

    1993-01-01

    Analyses of sediment samples collected near the mouth of White Oak Creek during the summer of 1990 revealed [sup 137]Cs concentrations [> 10[sup 6] Bq/kg dry wt (> 10[sup 4] pCi/g dry wt)] near the sediment surface. Available evidence indicates that these relatively high concentrations of [sup 137]Cs now at the sediment surface were released from White Oak Dam in the mid-1950s and had accumulated at depositionalsites in the embayment. These accumulated sediments are being eroded and transported downstream primarily during winter low-water levels by flood events and by a combination of normal downstream flow and the water turbulence created by the release of water from Melton Hill Dam during hydropower generation cycles. This report provides a more thorough characterization of the extent of contamination in WOCE than was previously available. Environmental samples collected from WOCE were analyzed for organic, inorganic, and radiological contaminants in fish, water, and sediment. These results were used to conduct a human health effects screening analysis. Walkover radiation surveys conducted inside the fenced area surrounding the WOCE at summer-pool (741 ft MSL) and at winter-pool (733 ft MSL) level, indicated a maximum exposure rate of 3 mR h[sup 1] 1 m above the soil surface.

  4. Stratigraphie relations of australites in the Port Campbell Embayment, Victoria

    USGS Publications Warehouse

    Shoemakeri, E.M.; Ralph, Uhlherr H.

    1999-01-01

    In the Port Campbell Embayment of Victoria, australites have been found in situ in channel deposits of the Hanson Plain Sand of Pliocene and Pleistocene age. The large majority of the australites, however, occur as a lag deposit at the basal contact of the Sturgess Sand of late Pleistocene and Holocene age and are spatially correlated with ferruginous sandstone clasts that are derived from the Hanson Plain Sand. Some of the tektites are imbedded in or bonded to the ferruginous sandstone clasts, but most are found as individual tektite fragments. A few percent of the tektites have nearly perfectly preserved, complete aerodynamically shaped forms. The sandstone clasts and associated tektites have been reworked from the much older underlying Hanson Plain and have been locally concentrated in the lag deposit. Some tektites also occur at higher levels in the Sturgess Sand, almost invariably in association with stone flakes, exotic stones transported by the aborigines and, locally, with middens of mollusc shells. Circumstantial evidence indicates that the aborigines transported the tektites found in the upper part of the Sturgess, particularly at Stanhope Bay. As Port Campbell australites unequivocally occur in strata much older than the late Pleistocene and Holocene Sturgess, there is no longer any conflict between the apparent stratigraphie age of the tektites and the middle Pleistocene ages obtained by various Chronometrie methods. ?? Meteoritical Society, 1999.

  5. An oceanic heat transport pathway to the Amundsen Sea Embayment

    NASA Astrophysics Data System (ADS)

    Rodriguez, Angelica R.; Mazloff, Matthew R.; Gille, Sarah T.

    2016-05-01

    The Amundsen Sea Embayment (ASE) on the West Antarctic coastline has been identified as a region of accelerated glacial melting. A Southern Ocean State Estimate (SOSE) is analyzed over the 2005-2010 time period in the Amundsen Sea region. The SOSE oceanic heat budget reveals that the contribution of parameterized small-scale mixing to the heat content of the ASE waters is small compared to advection and local air-sea heat flux, both of which contribute significantly to the heat content of the ASE waters. Above the permanent pycnocline, the local air-sea flux dominates the heat budget and is controlled by seasonal changes in sea ice coverage. Overall, between 2005 and 2010, the model shows a net heating in the surface above the pycnocline within the ASE. Sea water below the permanent pycnocline is isolated from the influence of air-sea heat fluxes, and thus, the divergence of heat advection is the major contributor to increased oceanic heat content of these waters. Oceanic transport of mass and heat into the ASE is dominated by the cross-shelf input and is primarily geostrophic below the permanent pycnocline. Diagnosis of the time-mean SOSE vorticity budget along the continental shelf slope indicates that the cross-shelf transport is sustained by vorticity input from the localized wind-stress curl over the shelf break.

  6. Southeast Georgia embayment high-resolution seismic-reflection survey

    USGS Publications Warehouse

    Edsall, Douglas W.

    1979-01-01

    A high-resolution seismic survey of the offshore part of the Southeast Georgia Embayment on about a 20 km spacing was completed in 1976. A stratigraphic analyses of the data shows that the largest controlling factor in the depositional history of the shelf has been the Gulf Stream. These currents have shifted back and forth across the shelf, at times incising into shelf sediments, and at all times blocking much of the accumulation of Cenozoic sediments seaward of the Florida-Hatteras Slope. In the southern region the Gulf Stream maintained its present position since Miocene time, blocking the accumulation of Pliocene and younger rocks on the Plateau. Northward, in the middle, region the currents turned slightly to the northeast. The inner portion of the Blake Plateau has been scoured of sediments since the Paleocene in this area, and scouring has also occurred on the shelf from time to time. In the northern part of the survey area a more easterly flow of the Gulf Stream has allowed Eocene and younger rocks to be deposited on the Plateau. Line drawings and a geologic map show the distribution of the various Cretaceous and Cenozoic units. A number of potential environmental hazards or constraints to petroleum development seen in the reflection data are identified. Besides current scour and erosion features, these include gravity faults on the slope, a slump, faulting on the inner Blake Plateau, the shelf edge reef, and deep water reefs on the Blake Plateau.

  7. Eutrophication risk assessment in coastal embayments using simple statistical models.

    PubMed

    Arhonditsis, G; Eleftheriadou, M; Karydis, M; Tsirtsis, G

    2003-09-01

    A statistical methodology is proposed for assessing the risk of eutrophication in marine coastal embayments. The procedure followed was the development of regression models relating the levels of chlorophyll a (Chl) with the concentration of the limiting nutrient--usually nitrogen--and the renewal rate of the systems. The method was applied in the Gulf of Gera, Island of Lesvos, Aegean Sea and a surrogate for renewal rate was created using the Canberra metric as a measure of the resemblance between the Gulf and the oligotrophic waters of the open sea in terms of their physical, chemical and biological properties. The Chl-total dissolved nitrogen-renewal rate regression model was the most significant, accounting for 60% of the variation observed in Chl. Predicted distributions of Chl for various combinations of the independent variables, based on Bayesian analysis of the models, enabled comparison of the outcomes of specific scenarios of interest as well as further analysis of the system dynamics. The present statistical approach can be used as a methodological tool for testing the resilience of coastal ecosystems under alternative managerial schemes and levels of exogenous nutrient loading.

  8. Detrital zircon study of the Dezful Embayment in the central Zagros, southern Iran

    NASA Astrophysics Data System (ADS)

    Hsieh, Hao Cheng; Chung, Sun Lin; Talebian, Morteza; Chen, Ling; Zarrinkoub, Mohammad H.; Lee, Hao Yang

    2016-04-01

    The Dezful Embayment of the Zagros Simply Folded Belt (ZFTB) in southern Iran is a foreland basin that formed as a flexural basin during the Miocene by the Zagros orogeny. This study reports a LA-ICPMS analysis of zircon U-Pb geochronology of 13 sedimentary rock samples from the Dezful Embayment, and five others from the Urumieh-Dokhtar magmatic arc (UDMA) and the Sanandaj-Sirjan zone (SSZ). In the northern and central parts of the Dezful Embayment, samples were collected from four principal sedimentary sequences including, from bottom to top, the Gachsaran Formation, Mishan Formation, Agha Jari Formation and Bakhtyari Formation. Our new zircon ages, together with published geochronological data from the UDMA and SSZ, can be used to better constrain the source provenance and tectonic implication of the Dezful Embayment related to the Arabia-Eurasia collision following the closure of Neo-Tethys. Samples of the UDMA and SSZ are characterized by abundant zircon ages of Eocene to Oligocene (55-25 Ma) and Jurassic (176-144 Ma), respectively. In the Dezful Embayment, detrital zircon age populations show significant variations. The age spectra of the northern Embayment show major peaks at the Precambrian (950-550 Ma), Late Carboniferous (323-299 Ma), Jurassic (176-144 Ma) and Eocene to Oligocene (55-25 Ma), with the last two age peaks suggesting an important source provenance from Eurasia, involving the SSZ and UDMA. By contrast, in the central Embayment, detrital zircons are dominated by Precambrian ages (2500 Ma, 1850 Ma, and 950-550 Ma), with rare Jurassic and Cenozoic ages. This suggests a different sedimentary source that we interpret to be the Arabian continent from the south. Moreover, gradual changes in the detrital zircon age spectra and thus in the source provenances are observed in different parts of the Dezful Embayment. The change in the northern Embayment occurred in the Agha Jari Formation, earlier than that in the central Embayment occurring between the

  9. ASSESSING TRANSBOUNDARY INFLUENCES IN THE LOWER RIO GRANDE VALLEY

    EPA Science Inventory

    The Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was a U.S.-Mexico Border XXI Program project to assess transboundary air pollution in and near Brownsville, Texas. The study used a three-site air monitoring network very close to the border to capture the d...

  10. Formation of Pedogenic Carbonates in the Semi-arid Rio Grande Valley: Insights from Carbon, Major elements, and U-series isotopes in Natural and Agricultural Soils of Southern New Mexico and Western Texas

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Jin, L.; Tweedie, C. E.

    2013-12-01

    Accumulation of pedogenic carbonates in arid and semi-arid soils affects soil porosity, water infiltration, and global carbon cycle. We investigate formation rates of these carbonates under different land uses in the semi-arid Rio Grande valley using mineralogy, concentrations of major elements (including C), and U-series isotopes. Our study sites include one alfalfa farm (Alfalfa) at El Paso, TX under frequent irrigation with saline water from the Rio Grande River, and one natural shrub field under natural rainfall conditions at the USDA Jornada Experimental Range (Jornada) in NM. Major minerals observed at Alfalfa and Jornada are calcite, quartz, and feldspars. Calcite/quartz ratios increase upward in the profile at Alfalfa, suggesting formation of carbonates in shallow soils. Consistently, total carbon increases toward the soil surface at Alfalfa, contributed by both soil organic carbon and soil inorganic carbon (pedogenic carbonates). Concentrations of major elements (e.g Ca, Mg, and Sr) also increase toward the surface at Alfalfa, suggesting surface addition. Alternating trends of enrichment and depletion are observed throughout the soil profiles. In contrast, calcite/quartz ratios decrease toward the surface at Jornada, indicative of leaching at shallow soils and redeposition of calcite at depth. This is in agreement with high soil inorganic carbon contents measured at depth. At Jornada however, the Ca, Mg and Sr concentrations decrease toward the surface, showing typical depletion profiles. (234U/238U) activity ratios in bulk soils increase upward at Alfalfa while at Jornada (234U/238U) ratios decrease toward the surface. (234U/238U) ratios at Alfalfa suggest surface addition of U onto shallow soils probably from irrigation water, which is known to have high (234U/238U) ratios. Jornada shows preferential loss of 234U upward. U-series disequilibrium in pedogenic carbonates enables calculation of their formation ages. At Alfalfa, carbonate ages range from 2

  11. Water-Quality Assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas--Surface-Water Quality, Shallow Ground-Water Quality, and Factors Affecting Water Quality in the Rincon Valley, South-Central New Mexico, 1994-95

    USGS Publications Warehouse

    Anderholm, Scott K.

    2002-01-01

    As part of the National Water-Quality Assessment Program, surface-water and ground-water samples were collected in 1994 and 1995 for analysis of common constituents, nutrients, dissolved organic carbon, trace elements, radioactivity, volatile organic compounds, and pesticides to characterize surface- water quality and shallow ground-water quality and to determine factors affecting water quality in the Rincon Valley, south-central New Mexico. Samples of surface water were collected from three sites on the Rio Grande and from sites on three agricultural drains in the Rincon Valley in January 1994 and 1995, April 1994, and October 1994. Ground-water samples were collected in late April and early May 1994 from 30 shallow wells that were installed during the investigation. Dissolved-solids concentrations in surface water ranged from 434 to 1,510 milligrams per liter (mg/L). Dissolved-solids concentrations were smallest in water from the Rio Grande below Caballo Dam and largest in the drains. Nitrite plus nitrate concentrations ranged from less than 0.05 to 3.3 mg/L as nitrogen, and ammonia concentrations ranged from less than 0.015 to 0.33 mg/L as nitrogen in surface-water samples. Trace-element concentrations in surface water were significantly smaller than the acute-fisheries standards. One or more pesticides were detected in 34 of 37 surface-water samples. DCPA (dacthal) and metolachlor were the most commonly detected pesticides. No standards have been established for the pesticides analyzed for in this study. Dissolved-solids concentrations in shallow ground water ranged from 481 to 3,630 mg/L. All but 2 of 30 samples exceeded the secondary maximum contaminant level for dissolved solids of 500 mg/L. Water from about 73 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for sulfate, and water from about 7 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for chloride. Nitrite plus nitrate

  12. The dynamics of cooling water discharge in a shallow, non-tidal embayment

    NASA Astrophysics Data System (ADS)

    Hofmeister, Richard; Bolding, Karsten; Hetland, Robert D.; Schernewski, Gerald; Siegel, Herbert; Burchard, Hans

    2013-12-01

    The dynamics of cooling water spreading in a non-tidal embayment is subject of a modelling-based study of Greifswald Bay, a shallow embayment at the south-western coast of the Baltic Sea. Potential cooling water spreading due to a possible power plant at Greifswald Bay is evaluated as differences between a realistic hind-cast simulation and a similar simulation but including the cooling water pumping. The model results are confirmed with satellite imagery of the embayment during operation of a nuclear power plant in the 1980s. The effect of cooling water pumping on the residual circulation, additional stratification and the heating of near-bed waters in the herring spawning areas is evaluated from the simulation. The model results for an idealised embayment and the realistic scenario, as well as the satellite images, show a clear dependence of the plume spreading on the wind direction. Although the surface plume affects a large area of the embayment, the results show a localised impact on residual circulation, bulk stratification and heating of the waterbody.

  13. Treasured Texas Theaters

    ERIC Educational Resources Information Center

    Horton, Anita

    2012-01-01

    Dallas artist Jon Flaming's deep love of Texas is evident in his paintings and sculpture. Although he has created one sculptural Texas theater, his work primarily showcases old Texas barbershops, vacant homes, and gas stations. In this article, the author describes how her students, inspired by Flaming's works, created three-dimensional historical…

  14. East Texas Storytellers.

    ERIC Educational Resources Information Center

    Anderson, Brandi, Ed.

    1987-01-01

    Written and published by the students at Gary High School, Gary, Texas, "Loblolly Magazine" is published twice a year. Issues are frequently devoted to a distant theme. The theme of this issue, "East Texas Storytellers," attempts to capture some of the local color and regional history of eastern Texas. The first article,…

  15. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; shallow ground-water quality of a land-use area in the San Luis Valley, south-central Colorado, 1993

    USGS Publications Warehouse

    Anderholm, S.K.

    1996-01-01

    This report describes the quality of shallow ground water in an agricultural area in the San Luis Valley, Colorado, and discusses how natural and human factors affect the quality of shallow ground water. Thirty-five wells were installed, and water samples were collected from these wells and analyzed for selected dissolved common constituents, nutrients, trace elements, radionuclides, and synthetic organic compounds. The San Luis Valley is a high intermontane valley that is partially drained by the Rio Grande. The San Luis Valley land-use study area was limited to a part of the valley where the depth to water is generally less than 25 feet. The area where the 35 monitor wells were installed was further limited to the part of the study area where center-pivot overhead sprinklers are used to irrigate crops. Precipitation, runoff from adjacent mountainous areas, and ground-water inflow from the adjacent mountainous areas are the main sources of water to the aquifers in the San Luis Valley. Discharge of water from the shallow, unconfined aquifer in the valley is mainly from evapotranspiration. The dominant land use in the San Luis Valley is agriculture, although nonirrigated land and residential land are interspersed with agricultural land. Alfalfa, native hay, barley, wheat, potatoes, and other vegetables are the main crops. Dissolved-solids concentrations in shallow ground water sampled ranged from 75 to 1,960 milligrams per liter. The largest median concentration of cations was for calcium, and the largest median concentration of anions was for bicarbonate in shallow ground water in the San Luis Valley. Calcium concentrations ranged from 7.5 to 300 milligrams per liter, and bicarbonate concentrations ranged from 28 to 451 milligrams per liter. Nitrite plus nitrate concentrations ranged from less than 0.1 to 58 milligrams per liter as N; water from 11 wells had nitrite plus nitrate concentrations greater than 10 milligrams per liter as N. With the exception of the

  16. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas : shallow ground-water quality and land use in the Albuquerque area, central New Mexico, 1993

    USGS Publications Warehouse

    Anderholm, Scott K.

    1997-01-01

    This report describes the quality of shallow ground water and the relations between land use and the quality of that shallow ground water in an urban area in and adjacent to Albuquerque, New Mexico. Water samples were collected from 24 shallow wells. Samples were analyzed for selected common constituents, nutrients, trace elements, radionuclides, volatile organic compounds, and pesticides. The study area, which is in the Albuquerque Basin in central New Mexico, was limited to the Rio Grande flood plain; depth to water in this area generally is less than 25 feet. The amount and composition of recharge to the shallow ground-water system are important factors that affect shallow ground-water composition in this area. Important sources of recharge that affect shallow ground-water quality in the area include infiltration of surface water, which is used in agricultural land-use areas to irrigate crops, and infiltration of septic-system effluent in residential areas. Agricultural land use represents about 28 percent of the area, and residential land use represents about 35 percent of the total study area. In most of the study area, agricultural land use is interspersed with residential land use and neither is the dominant land use in the area. Land use in the study area historically has been changing from agricultural to urban. The composition of shallow ground water in the study area varies considerably. The dissolved solids concentration in shallow ground water in the study area ranges from 272 to 1,650 milligrams per liter, although the relative percentages of selected cations and anions do not vary substantially. Calcium generally is the dominant cation and bicarbonate generally is the dominant anion. Concentrations of nutrients generally were less than 1 milligram per liter. The concentration of many trace elements in shallow ground water was below or slightly above 1 microgram per liter and there was little variation in the concentrations. Barium, iron, manganese

  17. Coastal loading and transport of Escherichia coli at an embayed beach in Lake Michigan

    USGS Publications Warehouse

    Ge, Z.; Nevers, M.B.; Schwab, D.J.; Whitman, R.L.

    2010-01-01

    A Chicago beach in southwest Lake Michigan was revisited to determine the influence of nearshore hydrodynamic effects on the variability of Escherichia coli (E. coli) concentration in both knee-deep and offshore waters. Explanatory variables that could be used for identifying potential bacteria loading mechanisms, such as bed shear stress due to a combined wave-current boundary layer and wave runup on the beach surface, were derived from an existing wave and current database. The derived hydrodynamic variables, along with the actual observed E. coli concentrations in the submerged and foreshore sands, were expected to reveal bacteria loading through nearshore sediment resuspension and swash on the beach surface, respectively. Based on the observation that onshore waves tend to result in a more active hydrodynamic system at this embayed beach, multiple linear regression analysis of onshore-wave cases further indicated the significance of sediment resuspension and the interaction of swash with gull-droppings in explaining the variability of E. coli concentration in the knee-deep water. For cases with longshore currents, numerical simulations using the Princeton Ocean Model revealed current circulation patterns inside the embayment, which can effectively entrain bacteria from the swash zone into the central area of the embayed beach water and eventually release them out of the embayment. The embayed circulation patterns are consistent with the statistical results that identified that 1) the submerged sediment was an additional net source of E. coli to the offshore water and 2) variability of E. coli concentration in the knee-deep water contributed adversely to that in the offshore water for longshore-current cases. The embayed beach setting and the statistical and numerical methods used in the present study have wide applicability for analyzing recreational water quality at similar marine and freshwater sites. ?? 2010 American Chemical Society.

  18. Coastal loading and transport of Escherichia coli at an embayed beach in Lake Michigan.

    PubMed

    Ge, Zhongfu; Nevers, Meredith B; Schwab, David J; Whitman, Richard L

    2010-09-01

    A Chicago beach in southwest Lake Michigan was revisited to determine the influence of nearshore hydrodynamic effects on the variability of Escherichia coli (E. coli) concentration in both knee-deep and offshore waters. Explanatory variables that could be used for identifying potential bacteria loading mechanisms, such as bed shear stress due to a combined wave-current boundary layer and wave runup on the beach surface, were derived from an existing wave and current database. The derived hydrodynamic variables, along with the actual observed E. coli concentrations in the submerged and foreshore sands, were expected to reveal bacteria loading through nearshore sediment resuspension and swash on the beach surface, respectively. Based on the observation that onshore waves tend to result in a more active hydrodynamic system at this embayed beach, multiple linear regression analysis of onshore-wave cases further indicated the significance of sediment resuspension and the interaction of swash with gull-droppings in explaining the variability of E. coli concentration in the knee-deep water. For cases with longshore currents, numerical simulations using the Princeton Ocean Model revealed current circulation patterns inside the embayment, which can effectively entrain bacteria from the swash zone into the central area of the embayed beach water and eventually release them out of the embayment. The embayed circulation patterns are consistent with the statistical results that identified that 1) the submerged sediment was an additional net source of E. coli to the offshore water and 2) variability of E. coli concentration in the knee-deep water contributed adversely to that in the offshore water for longshore-current cases. The embayed beach setting and the statistical and numerical methods used in the present study have wide applicability for analyzing recreational water quality at similar marine and freshwater sites.

  19. A new tool to assess groundwater resources in the Mississippi embayment

    USGS Publications Warehouse

    Clark, Brian R.; Freiwald, David A.

    2011-01-01

    What is the Mississippi Embayment? The Mississippi embayment study area encompasses approximately 78,000 square miles in eight States and includes large parts of Arkansas, Louisiana, Mississippi, and Tennessee, and smaller areas of Alabama, Illinois, Kentucky, and Missouri (fig. 1). The Mississippi embayment is essentially a basin that slopes toward the Gulf of Mexico and is filled with sediments of alternating sand, silt, and clay layers. There are two principal aquifers in the embayment-the Mississippi River Valley alluvial aquifer (alluvial aquifer) and the middle Claiborne aquifer (fig. 1). The shallow alluvial aquifer is the primary source of groundwater for irrigation in the largely agricultural region, while the deeper middle Claiborne aquifer is a primary source of drinking water for many of the 5.2 million people living in the embayment. The U.S. Geological Survey (USGS) is conducting large-scale multidisciplinary regional studies of groundwater availability for the Nation. Studies comprise individual assessments of regional groundwater-flow systems that encompass varied terrains and document a comprehensive regional and national perspective of groundwater resources. Collectively, these studies are the foundation for the national assessment of groundwater availability and are conducted in cooperation with other Federal, State, local governments, and the private sector. Numerical groundwater-flow models are used in these studies to document effects of human activities and climate variability on groundwater levels, changes in aquifer storage, and flow between groundwater and surface-water bodies. As part of the Mississippi Embayment Regional Aquifer Study (MERAS), a numerical model was constructed of 13 layers over 78,000 square miles representing multiple aquifers and confining units for the period of 1870 to 2007. The model is a tool that was used to assess and better understand groundwater resources.

  20. Statewide summary for Texas

    USGS Publications Warehouse

    Handley, Lawrence R.; Spear, Kathryn A.; Gibeaut, Jim; Thatcher, Cindy

    2014-01-01

    Seafood landed at Texas ports valued $240 million in 2011, and recreational saltwater fishing alone provided nearly 17,000 jobs (Texas GLO, 2013). Fishes directly dependent upon wetland habitats include multiple shrimp species, blue crab, eastern oyster, black drum, flounder, sheepshead, and snapper. Texas has the highest number of hunters, anglers, and hunting expenditures in the nation (U.S. Fish and Wildlife Service, 2012). Hunting yields $2.3 billion for the state, and recreational fishing yields $3.2 billion. Texas is the top birding destination in the Nation. Tourism in Texas generates $7.5 billion for the state, and wildlife viewing generates $2.9 billion.

  1. Seafloor environments in Cape Cod Bay, a large coastal embayment

    USGS Publications Warehouse

    Knebel, H. J.; Rendigs, R. R.; List, J.H.; Signell, R.P.

    1996-01-01

    Cape Cod Bay is a glacial, semi-enclosed embayment that has a patchy distribution of modern seafloor sedimentary environments of erosion or nondeposition, deposition, and sediment reworking. Sidescan-sonar records and supplemental bathymetric, sedimentary, subbottom, and physical- oceanographic data indicate that the characteristics and distribution of these three categories of bottom environments are controlled by a combination of geologic and oceanographic processes that range from episodic to long-term and from regional to local. (1) Environments of erosion or nondeposition comprise exposares of bedrock, glacial drift, and coarse lag deposits that contain sediments (where present) ranging from boulder fields to gravelly coarse-to-medium sands. These environments are dominant on the shallow margins of the bay (water depths <30 m) where they reflect sediment resuspension, winnowing, and transport during modern northerly storms. (2) Environments of deposition are blanketed by fine-grained sediments ranging from muds to muddy fine sands. These environments are dominant across the floor of the central basin (water depths= 30-60 m) where fine- grained sediments (derived from regional and local sources and emplaced primarily during episodic wind- and density-driven flow) settle through the water column and accumulate under weak bottom currents during nonstorm conditions. (3) Environments of sediment reworking contain patches with diverse textures ranging from gravelly sands to muds. These environments occupy much of the transitional slopes between the margins and the basin floor and reflect a combination of erosion and deposition. The patchy distribution of sedimentary environments within the bay reflects not only regional changes in processes between the margins and the basin but local changes within each part of the bay as well. Small-scale patchiness is caused by local changes in the strengths of wave- and wind-driven currents and (on the margins) by local

  2. Modern foraminifera assemblages in the Amundsen Sea Embayment

    NASA Astrophysics Data System (ADS)

    Ewa Jernas, Patrycja; Kuhn, Gerhard; Hillenbrand, Claus-Dieter; Lander Rasmussen, Tine; Forwick, Matthias; Mackensen, Andreas; Schröder, Michael; Smith, James; Klages, Johann Philipp

    2015-04-01

    The West Antarctic Ice Sheet (WAIS) is considered the most unstable part of the Antarctic Ice Sheet. As the WAIS is mostly grounded below sea level, its stability is of great concern. A collapse of large parts of the WAIS would result in a significant global sea-level rise. At present, the WAIS shows dramatic ice loss in its Amundsen Sea sector, especially in Pine Island Bay. Pine Island Glacier (PIG) is characterised by fast flow, major thinning and rapid grounding-line retreat. Its mass los over recent decades is generally attributed to melting caused by the inflow of warm Circumpolar Deep Water (CDW). Future melting of PIG may result in a sea level tipping point, because it could trigger widespread collapse of the WAIS, especially when considering ongoing climate change. Our research project aims to establish proxies (integration of foraminifera, sediment properties and oceanographic data) for modern environmental conditions by analysing seafloor surface sediments along a transect from the glacier proximal settings to the middle-outer shelf in the eastern Amundsen Sea Embayment. These proxies will then be applied on sediment records spanning the Holocene back to the Last Glacial Maximum for reconstructing spatial and temporal variations of CDW upwelling and ice-ocean interactions during the past c. 23,000 years. We will present preliminary results from the analyses of ten short marine sediment cores (multi and box cores) collected during expeditions JR179 (2008) and ANT-XXVI/3 (2010) along a transect from inner Pine Island Bay to the middle-outer shelf part of the Abbot Palaeo-Ice Stream Trough at water depths ranging from 458 m (middle shelf) to 1444 m (inner shelf). The sediment cores are currently investigated for distribution patterns of planktonic and benthic foraminifera and grain-size distribution at 1 cm resolution. Core tops (0-10 cm) were stained with Rose Bengal for living benthic foraminifera investigations. The chronology of the cores will be based

  3. Simulating the hydrologic impact of Arundo donax invasion on the headwaters of the Nueces River in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arundo donax (hereafter referred to as Arundo), which is a robust herbaceous plant, has invaded the riparian zones of the Rio Grande River and the rivers of the Texas Hill Country over the last two decades. Arundo was first observed along the Nueces River in central Texas in 1995 by the Nueces Rive...

  4. FEASIBILITY STUDY OF CLIMATE CHANGE IMPACTS ON NITROGEN IN CAPE COD EMBAYMENTS

    EPA Science Inventory

    The objective of this study is to explore the feasibility of studying potential effects of climate change on impairments resulting from nitrogen loadings in the salt water embayments of Cape Cod. The report includes a recommended plan for studying these impacts, an estimate of t...

  5. Early Monitoring Approaches Developed from a Case Study on a Vulnerable Great Lakes Embayment

    EPA Science Inventory

    Great Lakes harbors/embayments are at high risk of introduction of invasive species. Monitoring is needed to inform on new introductions, and to track success of programs to limit invasion or spread. A field case study was conducted in the Duluth-Superior Harbor/St. Louis River, ...

  6. The Estuary Book: A Guide to Promoting Understanding and Regional Management of Maine's Estuaries and Embayments.

    ERIC Educational Resources Information Center

    Ruffing, Jenny

    The objective of this document is to provide information about estuaries, the impact of uses on the environmental health of an estuary, and what communities and concerned individuals can do to manage and protect their local estuarine resources successfully. Much of the information presented here pertains to other embayments along the Maine coast…

  7. Geomorphic modeling of macro-tidal embayment with extensive tidal flats: Skagit Bay, Washington

    DTIC Science & Technology

    2012-09-30

    DISTRIBUTION A: Distribution approved for public release; distribution is unlimited. Geomorphic modeling of macro- tidal embayment with extensive... tidal flats: Skagit Bay, Washington Lyle Hibler Battelle-Pacific Northwest Division Marine Sciences Laboratory Sequim, WA 98382 phone: (360) 681...of muddy tidal flats and to quantify the effects of tidal action, river discharge, and shoreline development (e.g. dikes and jetties) on these

  8. RELATIONSHIPS BETWEEEN NITROGEN LOADING AND CONCENTRATIONS OF NITROGEN AND CHLOROPHYLL IN COASTAL EMBAYMENTS

    EPA Science Inventory

    We describe results obtained with a simple model that uses loading rates of total nitrogen (TN), defined as dissolved inorganic nitrogen plus dissolved and particulate organic nitrogen, to calculate annually and spatially averaged concentrations of TN in coastal embayments. We al...

  9. Robust Segmentation of Embayments to Encompass Exposure and Changes in Constituent Load

    EPA Science Inventory

    Nutrient and contaminant loads from the watershed, atmosphere, and seaward boundary to an embayment continually change due to human activities and alterations in the trends of natural forcing. Nevertheless, residence time (a measure of exposure) is always viewed as an unchanging ...

  10. An Eocene flora from trans-Pecos Texas

    USGS Publications Warehouse

    Berry, Edward Wilber

    1920-01-01

    During the fall of 1916 I received a small collection of fossil plants which had been obtained during a geologic reconnaissance of the trans-Pecos region of Texas, by Charles Lawrence Baker. A preliminary report was sent to Mr. Baker in November of that year and was quoted in his discussion of the geology of that region. I have since made a careful study of the collection, and although it contains only a few species the occurrence of fossil plans in this region is worthy of more definite and detailed record, especially as these plants enabled me to assign a definite age to the beginning of the igneous activity of the region and to establish correlations between the floras of the Mississippi embayment and the Rocky Mountain Region.

  11. John Holt Stanway: Gone to Texas

    NASA Astrophysics Data System (ADS)

    Bryan, J.

    2008-01-01

    John Holt Stanway (1799Ð1872) was an amateur astronomer who lived in Manchester, England until 1845. He was in contact with the English Ôgrand amateurÕ astronomer, William Henry Smyth, who supported him for Fellowship of the Royal Astronomical Society and evidently advised him on how to build and equip an observatory. Apparently, Stanway had an observatory at Chorlton-cum-Hardy in 1837. In 1845, Stanway left for the United States in response to serious business problems. En route, he met Ashbel Smith, a representative of the government of the Republic of Texas, who convinced Stanway to go to Texas. There he changed his name to John H. Smythe Stanley and settled in Houston, where he re-established his observatory. He became a commercial photographer and wrote about astronomy and other scientific subjects in Houston newspapers until his death in 1872.

  12. Marine carbonate embayment system in an Eolian dune terrain, Permian Upper Minnelusa Formation, Rozet Area, Powder River Basin, Wyoming

    SciTech Connect

    Achauer, C.W.

    1987-05-01

    The eolian origin for Minnelusa sandstones has been stressed in numerous published articles. However, the dolomites that are interbedded with the eolian sandstones have received little attention. Isopach mapping of one of the dolomite units (Dolomite I) reflects a marine embayment system whose individual embayments range from 1/2 to 1 mi in width and trend primarily in a northwest direction. Consistently the embayment dolomites pinch out against the flanks of reworked, low relief, broad, eolian dune ridges. So far, 108 mi/sup 2/ of the Dolomite I marine embayment system have been mapped, but the overall extent of the system is undoubtedly much greater. Dolomite I is rarely cored, but cores from stratigraphically higher embayment dolomites in the upper Minnelusa show that these dolomites display the following, shoaling-upward sequence: (1) subtidal, sparingly fossiliferous dolomite; (2) intertidal, algal-laminated or brecciated or mud-cracked dolomite; and (3) very thin, supratidal, nodular anhydrite. The embayments, therefore, became the sites of marine sabkhas located between eolian dunes. Two main conclusions emerge from this study: (1) the juxtaposition of eolian sandstones and marine dolomites in a tectonically stable area suggests that eustatic sea level changes and a very arid climate were responsible for the marked environmental and lithologic changes observed in the upper Minnelusa, and (2) arid, coastal, evaporitic sabkhas bordered by eolian dunes are known from a number of modern and ancient cases, but marine carbonate embayments and associated evaporitic sabkhas that penetrate deeply into eolian sandstone terrains are rare.

  13. Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

    NASA Astrophysics Data System (ADS)

    Ferguson, David J.; Gonnermann, Helge M.; Ruprecht, Philipp; Plank, Terry; Hauri, Erik H.; Houghton, Bruce F.; Swanson, Donald A.

    2016-10-01

    The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete exsolution of H2O, CO2, and S from the embayment melts during eruptive ascent creates diffusion profiles that can be measured using microanalytical techniques, and then modeled to infer the average decompression rate. We obtain average rates of ~0.05-0.45 MPa s-1 for eruptions ranging from Hawaiian style fountains to basaltic subplinian, with the more intense eruptions having higher rates. The ascent timescales for these magmas vary from around ~5 to ~36 min from depths of ~2 to ~4 km, respectively. Decompression-exsolution models based on the embayment data also allow for an estimate of the mass fraction of pre-existing exsolved volatiles within the magma body. In the eruptions studied, this varies from 0.1 to 3.2 wt% but does not appear to be the key control on eruptive intensity. Our results do not support a direct link between the concentration of pre-eruptive volatiles and eruptive intensity; rather, they suggest that for these eruptions, decompression rates are proportional to independent estimates of mass discharge rate. Although the intensity of eruptions is defined by the discharge rate, based on the currently available dataset of embayment analyses, it does not appear to scale linearly with average decompression rate. This study demonstrates the utility of the embayment method for providing quantitative constraints on magma ascent during explosive basaltic eruptions.

  14. Bulk sediment Qp and Qs in the Mississippi embayment, central United States

    USGS Publications Warehouse

    Langston, C.A.; Bodin, P.; Powell, C.; Withers, M.; Horton, S.; Mooney, W.

    2005-01-01

    We have estimated P-wave and S-wave anelastic attenuation coefficients for the thick, unconsolidated sediments of the Mississippi embayment, central United States, using the spectral distance decay of explosion P and Rayleigh waves. The sediment-trapped P wave, Psed, is observed to ranges of 80 km at 10 Hz, and 1-Hz Rayleigh waves are observed out to 130 km from a 5000-lb borehole explosion in the northern part of the embayment. Rayleigh waves of 4 Hz are seen to distances of 3 km from a smaller 50-lb explosion. Analysis of the group velocity and amplitude-distance decay of both waves yields an average Qs of 100 and Qp of 200 for embayment sediments that are independent of frequency. Scatter in the Q estimates comes from interference of multiple P-wave reverberations and Rayleigh-wave modes. The attenuation model is self-consistent in that it is the same as obtained by the analysis of synthetic seismograms using the inferred Q-values. Inferred Qp and Qs values are more than three times higher than previous estimates and imply that unconsolidated sediments of the embayment do not significantly attenuate small-strain earthquake ground motions. These estimates represent a lower bound to Q of the sediments since significant scattering is observed in the waveform data that contributes to the distance decay of wave amplitude. Higher Q values also imply that the unconsolidated sediments of the embayment will form an efficient wave guide for surface waves radiated from shallow earthquakes or large earthquakes that rupture into the sediments, producing high-amplitude, long-duration wave trains that should be considered in earthquake hazard assessments.

  15. Rift processes and crustal structure of the Amundsen Sea Embayment, West Antarctica, from 3D potential field modelling

    NASA Astrophysics Data System (ADS)

    Kalberg, Thomas; Gohl, Karsten; Eagles, Graeme; Spiegel, Cornelia

    2015-12-01

    The Amundsen Sea Embayment of West Antarctica is of particular interest as it provides critical geological boundary conditions in better understanding the dynamic behavior of the West Antarctic Ice Sheet, which is undergoing rapid ice loss in the Amundsen Sea sector. One of the highly debated hypothesis is whether this region has been affected by the West Antarctic Rift System, which is one of the largest in the world and the dominating tectonic feature in West Antarctica. Previous geophysical studies suggested an eastward continuation of this rift system into the Amundsen Sea Embayment. This geophysical study of the Amundsen Sea Embayment presents a compilation of data collected during two RV Polarstern expeditions in the Amundsen Sea Embayment of West Antarctica in 2006 and 2010. Bathymetry and satellite-derived gravity data of the Amundsen Sea Embayment complete the dataset. Our 3-D gravity and magnetic models of the lithospheric architecture and development of this Pacific margin improve previous interpretations from 2-D models of the region. The crust-mantle boundary beneath the continental rise and shelf is between 14 and 29 km deep. The imaged basement structure can be related to rift basins within the Amundsen Sea Embayment, some of which can be interpreted as products of the Cretaceous rift and break-up phase and some as products of later propagation of the West Antarctic Rift System into the region. An estimate of the flexural rigidity of the lithosphere reveals a thin elastic thickness in the eastern embayment which increases towards the west. The results are comparable to estimates in other rift systems such as the Basin and Range province or the East African Rift. Based on these results, we infer an arm of the West Antarctic Rift System is superposed on a distributed Cretaceous rift province in the Amundsen Sea Embayment. Finally, the embayment was affected by magmatism from discrete sources along the Pacific margin of West Antarctica in the Cenozoic.

  16. Guidebook to Rio Grande rift in New Mexico

    USGS Publications Warehouse

    Hawley, J. W.

    1978-01-01

    Discusses the details of geologic features along the rift zone. Included are short papers on topics relative to the overall region. These papers and the road logs are of special interest to any one pursuing further study of the rift. This book is a comprehensive guide to the middle and late Cenozoic geology of the Rio Grande region of Colorado and New Mexico. Though initially used on field trips for the International Symposium on Tectonics and Magmatism of the Rio Grande rift, the guidebook will be useful to anyone interested in the Cenozoic history of the 600-mi-long area extending from central Colorado to El Paso, Texas.

  17. Hyacinths Choke the Rio Grande

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These images acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), flying aboard NASA's Terra satellite, demonstrate the potential of satellite-based remote sensors to monitor infestations of non-native plant species. These images show the vigorous growth of water hyacinths along a stretch of the Rio Grande River in Texas. The infestation had grown so dense in some places it was impeding the flow of water and rendered the river impassible for boats. The hyacinth is an aquatic weed native to South America. The plant is exotic looking and, when it blooms, the hyacinth produces a pretty purple flower, which is why it was introduced into North America. However, it has the capacity to grow and spread at astonishing rates so that in the wild it can completely clog the flow of rivers and waterways in a matter of days or weeks. The top image was acquired on March 30, 2002, and the bottom image on May 9, 2002. In the near-infrared region of the spectrum, photosynthetically-active vegetation is highly reflective. Consequently, vegetation appears bright to the near-infrared sensors aboard ASTER; and water, which absorbs near-infrared radiation, appears dark. In these false-color images produced from the sensor data, healthy vegetation is shown as bright red while water is blue or black. Notice a water hyacinth infestation is already apparent on March 30 near the center of the image. By May 9, the hyacinth population has exploded to cover more than half the river in the scene. Satellite-based remote sensors can enable scientists to monitor large areas of infestation like this one rather quickly and efficiently, which is particularly useful for regions that are difficult to reach from on the ground. (For more details, click to read Showdown in the Rio Grande.) Images courtesy Terrametrics; Data provided by the ASTER Science Team

  18. 75 FR 3277 - Notice of Final Federal Agency Actions on State Highway 99 (Segment F-2) in Texas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ... Federal Highway Administration Notice of Final Federal Agency Actions on State Highway 99 (Segment F-2) in... actions relate to a proposed highway project, Grand Parkway (State Highway 99) Segment F-2, from State... the following highway project in the State of Texas: Grand Parkway (State Highway 99) Segment F-2...

  19. Rio Grande valley Colorado new Mexico and Texas

    USGS Publications Warehouse

    Ellis, Sherman R.; Levings, Gary W.; Carter, Lisa F.; Richey, Steven F.; Radell, Mary Jo

    1993-01-01

    Two structural settings are found in the study unit: alluvial basins and bedrock basins. The alluvial basins can have through-flowing surface water or be closed basins. The discussion of streamflow and water quality for the surface-water system is based on four river reaches for the 750 miles of the main stem. the quality of the ground water is affected by both natural process and human activities and by nonpoint and point sources. Nonpoint sources for surface water include agriculture, hydromodification, and mining operations; point sources are mainly discharge from wastewater treatment plants. Nonpoint sources for ground water include agriculture and septic tanks and cesspools; point sources include leaking underground storage tanks, unlined or manure-lined holding ponds used for disposal of dairy wastes, landfills, and mining operations.

  20. Migrant Worker: A Boy from the Rio Grande Valley.

    ERIC Educational Resources Information Center

    Hoyt-Goldsmith, Diane

    Ricky is an 11-year-old migrant worker. During the summer, he travels with his family from their home in Rio Grande City, Texas, to farms farther north. There they spend 10-12 hours a day in the hot sun picking fruit and vegetables and packing the harvest for market. Ricky is not protected by the federal laws that govern the hours, wages, and…

  1. STEM education for teachers in the Rio Grande Valley

    NASA Astrophysics Data System (ADS)

    Ries, Judit Gyorgyey; Baguio, Margaret R.

    2015-11-01

    We have worked with elementary and middle school teachers in the Rio Grande Valley for the last 10 years bringing Earth and Space Science themed workshops to underserved areas of Texas. The Texas curriculum was also changed to include Astronomy and Space Science requirement in the tests students need to take to prove their academic preparedness. The teachers worked through a variety of inquiry-based, hands-on activities after a short presentation on the background science. In order to evaluate our effectiveness, we have asked the teachers to take pre- and post-workshop tests, and we asked them to fill out a self-reflective survey. We will report on our experiences, what works best with the teachers, and in what areas we still have a long way to go.This work was supported by various NASA education grants and Cooperative agreements, as well as grants provided by the Texas Space Grant Consortium.

  2. Migrant Programs in Texas.

    ERIC Educational Resources Information Center

    Carrasco, Frank, Ed.

    The purpose of this handbook is to provide information on migrant programs and services in the state of Texas. Data are gathered from 92 of the 254 counties in Texas. There is a profile for each county selected and for all migrant programs identified in each county. Descriptions of Title III-B migrant programs, the High School Equivalency program,…

  3. Earthquake history of Texas

    USGS Publications Warehouse

    von Hake, C. A.

    1977-01-01

    Seventeen earthquakes, intensity V or greater, have centered in Texas since 1882, when the first shock was reported. The strongest earthquake, a maximum intensity VIII, was in western Texas in 1931 and was felt over 1 165 000 km 2. Three shocks in the Panhandle region in 1925, 1936, and 1943 were widely felt. 

  4. Fireball Over Texas

    NASA Video Gallery

    Video of the fireball seen over Texas this morning (12/7/12); it was taken by a NASA camera located near Mayhill, New Mexico. It is very unusual for us to see a meteor all the way across Texas. The...

  5. Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.

    USGS Publications Warehouse

    Culver, Stephen J.; Farrell, Kathleen M.; Mallinson, David J.; Willard, Debra A.; Horton, Benjamin P.; Riggs, Stanley R.; Thieler, E. Robert; Wehmiller, John F.; Parham, Peter; Snyder, Scott W.; Hillier, Caroline

    2011-01-01

    To understand the temporal and spatial variation of eustatic sea-level fluctuations, glacio-hydro-isostacy, tectonics, subsidence, geologic environments and sedimentation patterns for the Quaternary of a passive continental margin, a nearly complete stratigraphic record that is fully integrated with a three dimensional chronostratigraphic framework, and paleoenvironmental information are necessary. The Albemarle Embayment, a Cenozoic regional depositional basin in eastern North Carolina located on the southeast Atlantic coast of the USA, is an ideal setting to unravel these dynamic, interrelated processes.Micropaleontological data, coupled with sedimentologic, chronostratigraphic and seismic data provide the bases for detailed interpretations of paleoenvironmental evolution and paleoclimates in the 90. m thick Quaternary record of the Albemarle Embayment. The data presented here come from a transect of cores drilled through a barrier island complex in the central Albemarle Embayment. This area sits in a ramp-like setting between late Pleistocene incised valleys.The data document the episodic infilling of the Albemarle Embayment throughout the Quaternary as a series of transgressive-regressive (T-R) cycles, characterized by inner shelf, midshelf, and shoreface assemblages, that overlie remnants of fluvial to estuarine valley-fill. Barrier island and marginal marine deposits have a low preservation potential. Inner to mid-shelf deposits of the early Pleistocene are overlain by similar middle Pleistocene shelf sediments in the south of the study area but entirely by inner shelf deposits in the north. Late Pleistocene marine sediments are of inner shelf origin and Holocene deposits are marginal marine in nature. Pleistocene marine sediments are incised, particularly in the northern half of the embayment by lowstand paleovalleys, partly filled by fluvial/floodplain deposits and in some cases, overlain by remnants of transgressive estuarine sediments. The shallowing

  6. Penokean tectonics along a promontory-embayment margin in east-central Minnesota

    USGS Publications Warehouse

    Chandler, V.W.; Boerboom, Terrence; Jirsa, M.A.

    2007-01-01

    Recent geologic investigations in east-central Minnesota have utilized geophysical data, test drilling, and high-resolution geochronologic dating to produce a significantly improved map of a poorly exposed part of the 1880-1830 Ma Penokean orogen. These investigations have elucidated major changes in the structure of the orogen, as compared to its counterparts in northern Michigan and northwestern Wisconsin. Foreland basin, fold and thrust belt, and magmatic terrane components that are recognized to the east extend into east-central Minnesota, but they appear to be deflected southwards and truncated in proximity to Archean rocks of the Minnesota River Valley (MRV) subprovince. In contrast, the interior of the MRV subprovince to the southwest shows little sign of Penokean tectonism. In addition, the magmatic and metamorphic rocks of the internal zone of the orogen in east-central Minnesota are extensively invaded by ca. 1785-1770 Ma granitic rocks (the East-Central Minnesota Batholith), whereas, post-orogenic granites of this age occur sparingly to the east. These differences in orogenic structure may be related to their location near the juncture of an embayment (Becker embayment) and a promontory (MRV promontory) that formed the pre-Penokean continental margin. In this scenario, the MRV promontory, which at the surface consists chiefly of high-metamorphic-grade Mesoarchean gneisses, would have formed competent, high-standing crust that resisted deformation and did not host significantly thick continental margin sequences. In contrast, the part of the Becker Embayment adjoining the promontory would have involved relatively weak, low-standing crust that favored deposition of continental margin sequences and, during Penokean collision, would have accommodated tectonic loading of the cratonic margin through thin-skinned deformation. Thrusting of thick embayment sequences and possibly a block of Archean crust (Marshfield terrane) onto the embayment margin may have

  7. Could narrow marine embayments prevent sea-glacier invasion, and protect photosynthetic life during a Snowball Earth?

    NASA Astrophysics Data System (ADS)

    Campbell, Adam J.

    During the Snowball Earth events of the Neoproterozoic, the Earth's oceans may have been completely covered in ice. This ice would have been thick enough to prohibit the transmission of light to the liquid water underneath the entirely frozen surface of the ocean. However, photosynthetic eukaryotes are thought to have survived during these events. This is the first work to throughly attempt to reconcile how photosynthetic eukaryotes survived on a planet with a completely frozen ocean surface. Narrow marine embayments like the modern-day Red Sea, would restrict the inflow of sea glaciers. These embayments, if located in regions of net sublimation, would restrict sea-glacier invasion and could provide refuge for these organisms at the end of their channels. This work demonstrates that under a set of climate conditions and channel geometries, narrow marine embayments allow for incomplete sea-glacier invasion, a necessary condition for marine embayments to provide refugia.

  8. Geophysical Log Database for the Mississippi Embayment Regional Aquifer Study (MERAS)

    USGS Publications Warehouse

    Hart, Rheannon M.; Clark, Brian R.

    2008-01-01

    The Mississippi Embayment Regional Aquifer Study (MERAS) is an investigation of ground-water availability and sustainability within the Mississippi embayment as part of the U.S. Geological Survey Ground-Water Resources Program. The MERAS area consists of approximately 70,000 square miles and encompasses parts of eight states including Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee. More than 2,600 geophysical logs of test holes and wells within the MERAS area were compiled into a database and were used to develop a digital hydrogeologic framework from land surface to the top of the Midway Group of upper Paleocene age. The purpose of this report is to document, present, and summarize the geophysical log database, as well as to preserve the geophysical logs in a digital image format for online access.

  9. Improving Constraints on Paleo Ice Sheets in the Amundsen Sea Embayment

    NASA Astrophysics Data System (ADS)

    Larter, Robert D.; Gohl, Karsten; Bentley, Michael J.

    2010-01-01

    Amundsen Sea Embayment: Tectonic and Climatic Evolution; Granada, Spain, 9 September 2009; Geoscientists working on the Amundsen Sea Embayment (ASE) of West Antarctica met at a workshop during the First Antarctic Climate Evolution Symposium to discuss recent advances from, and future priorities for, work in this region. The ASE is the most rapidly changing sector of the West Antarctic Ice Sheet (WAIS) and contains enough ice to raise sea level by 1.2 meters. Ice sheet modeling studies suggest that this sector of the WAIS is potentially unstable. Considerable efforts have been made through several national Antarctic programs to acquire new data on the geological structure, subglacial topography, bathymetry, and glacial history of this remote region. These data are important for establishing boundary conditions for ice sheet modeling, for providing constraints on past ice sheet changes that can be used to test models, and for putting recent changes into a longer-term context.

  10. Burrowing mayflies as indicators of ecosystem health: status of populations in two western Lake Superior embayments

    USGS Publications Warehouse

    Edsall, Thomas A.; Gorman, Owen T.; Evrard, Lori M.

    2004-01-01

    The U.S. Environmental Protection Agency and Environment Canada are supporting the development of indicators of ecosystem health that can be used to report on progress in restoring and maintaining the Great Lakes ecosystem, as called for in the Great Lakes Water Quality Agreement between the United States and Canada. One indicator under development for Great Lakes mesotrophic environments is based on burrowing mayflies ( Hexagenia: Ephemeroptera: Ephemeridae). In this paper, we report the results of a benthic survey in spring 2002 to determine the status of nymphal populations of Hexagenia in two western Lake Superior embayments, the St. Louis River estuary, an area with significant water-use impairments, and Chequamegon Bay, an area with no known water-use impairments. Ponar grab samples collected throughout these embayments showed nymphs were generally abundant in finely particulate, cohesive substrate (clay or mixtures of clay and sand) in both embayments. However, in the St. Louis River estuary nymphs were absent in those preferred substrates at 11 stations in the eastern portion of St. Louis Bay and the adjoining northwestern portion of the Duluth-Superior Harbor, where the sediments were variously contaminated with visible amounts of taconite pellets, paint chips, oil, or combusted coal waste (clinkers). Our results suggest that human activities have rendered those portions of the St. Louis River estuary unsuitable for habitation by Hexagenia nymphs and we recommend that trend monitoring of the nymphal population there be conducted to permit reporting on progress in restoring and maintaining the health and integrity of this Great Lakes ecosystem embayment, consistent with the intent of the Great Lakes Water Quality Agreement.

  11. Continental Shelf Embayments of the Eastern Margin of the Philippines; Lamon Bay Stratification & Circulation

    DTIC Science & Technology

    2012-09-30

    in 2011. Data from R/V Revelle hull mounted ADCP. The hull ADCP and the CTD thermohaline stratification reveal a shift in circulation pattern...Philippines; Lamon Bay Stratification & Circulation Arnold L. Gordon Lamont-Doherty Earth Observatory 61 Route 9W Palisades, NY 10964-8000... circulation , stratification and the Shelf-Slope interaction, and the resultant ocean productivity, within a major embayment, Lamon Bay, of the eastern

  12. Correlation of Twin Creek limestone with Arapien shale in Arapien embayment, Utah - preliminary appraisal

    SciTech Connect

    Sprinkel, D.A.; Waanders, G.L.

    1984-07-01

    Striking and important stratigraphic patterns have emerged as a result of recent work during which members of the Twin Creek Limestone were correlated with the Arapien Shale, all of Middle Jurassic age. These correlations, determined first on the basis of electric and lithologic logs, are supported by recent palynologic work. Three distinct dinoflagellate assemblages, assigned to the Bajocian(.), Bathonian, and Callovian stages, form the paleontologic basis for these correlations. The Bajocian(.) assemblage is found in rocks of the Sliderock and Rich Members of the Twin Creek Limestone. The Bathonian assemblage is found in units of the Boundary Ridge and Watton Canyon Members of the Twin Creek, and also in units of the lower Arapien Shale (lower Leeds Creek Member of the Twin Creek of Wyoming). The Callovian assemblage is found in rocks of the upper Arapien (upper Leeds Creek and Giraffe Creek Members of the Twin Creek of Wyoming). Isopach maps, based on these correlations, indicate that most of central Utah was the site of a large marine embayment - the Arapien embayment -that was flanked on the west, south, and east by highlands. The maps also suggest that the ancestral Uinta Mountains, a submerged feature, affected sedimentation as early as Bajocian time, and became a significant barrier from the late Bathonian through Callovian. In central Utah, marine carbonates were deposited in the Arapien embayment during deposition of the Gypsum Spring through Watton Canyon Members of the Twin Creek Limestone. During deposition of the Arapien Shale, a major northward regression occurred; the embayment shrank to form a smaller basin - the Arapien basin - that lay directly south of the ancestral Uinta Mountains. Most of the Arapien Shale is shallow-water deposits that formed in the basin under hypersaline conditions.

  13. Digital Surfaces and Thicknesses of Selected Hydrogeologic Units within the Mississippi Embayment Regional Aquifer Study (MERAS)

    USGS Publications Warehouse

    Hart, Rheannon M.; Clark, Brian R.; Bolyard, Susan E.

    2008-01-01

    Digital surfaces of selected Tertiary and younger age hydrogeologic units within the Mississippi embayment aquifer system were created using more than 2,600 geophysical logs for an area that covers approximately 70,000 square miles and encompasses parts of eight states. The digital surfaces were developed to define and display the hydrogeologic framework for the Mississippi Embayment Regional Aquifer Study (MERAS). The digital surfaces also provide a foundation of the selected hydrogeologic units for development of a steady-state and transient regional ground-water flow model of the Mississippi embayment aquifer system from the top of the Midway confining unit upwards to land surface. The ground-water flow model is under development as part of the U.S. Geological Survey Ground-Water Resources Program. Using a Geographic Information System, nine digital surfaces of the tops of selected hydrogeologic units were created using the Australian National University Digital Elevation Model method as an interpolation scheme. Thickness maps also were constructed using the Geographic Information System by calculating the difference between the altitude of the interpreted base of an overlying unit and the altitude of the interpreted top of an underlying unit. In general, the highest hydrogeologic unit altitudes are located along the eastern edge of the study area in the outcrop, and the lowest altitudes, in general, are located along the southern edge of the study area along the axis of the embayment. The Mississippi River Valley alluvial aquifer and the lower Claiborne aquifer are the thinnest aquifers of importance in the study area; the thickest aquifer of importance is the middle Claiborne aquifer.

  14. Tsunami inundation and sediment transport in a sediment-limited embayment on American Samoa

    USGS Publications Warehouse

    Apotsos, A.; Gelfenbaum, G.; Jaffe, B.; Watt, Sebastian; Peck, B.; Buckley, M.; Stevens, A.

    2011-01-01

    Field observations and numerical simulations are used to explore tsunami inundation and sediment transport in an embayment (Fagafue Bay) on the north side of Tutuila, American Samoa during the 29 September 2009 South Pacific tsunami. Field observations of the nearshore bathymetry and topography, tsunami flow depth and sediment deposition, and extent of movable sandy sediment remaining on the beach were collected during two field surveys approximately two and five weeks after the tsunami. Onshore measurements of flow depth at forty-eight locations indicate the wave inundated almost 250. m onshore with a depth exceeding 7. m locally. The tsunami deposited patchy areas of sediment up to 0.2. m thick interspersed with a thin dusting (< 0.01 m) of sandy sediment throughout most of the inundated area. A numerical simulation based on the best available topography and bathymetry and a simplified offshore wave forcing is calibrated with the onshore flow observations. The calibrated model is used to simulate tsunami-induced sediment transport within and onshore of both the actual embayment and several idealized embayments. The simulations show that the onshore deposition of sediment can be affected by more than 50% by both the amount of sediment available for transport and the steepness of the onshore topography, suggesting these effects may need to be considered when interpreting tsunami deposits.

  15. Late Wisconsin and early holocene glacial history, inner Ross Embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Denton, George H.; Bockheim, James G.; Wilson, Scott C.; Stuiver, Minze

    1991-05-01

    Lateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore, Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and younger (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000 to 13,000 yr B.P. Outlet glacier profiles from these drifts constrain late Wisconsin ice sheet surface elevations. Within these constraint, two extreme late Wisconsin reconstructions are given of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment, one reconstruction shows floating shelf ice, where as the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600 to 6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains.

  16. Sediment dynamics of a sediment-starved, open-marine marsh embayment: Waccasassa Bay, Florida

    USGS Publications Warehouse

    Wood, Nathan J.; Hine, Albert C.

    2003-01-01

    Although the Big Bend region of Florida's Gulf of Mexico coast is considered sediment-starved, the open marine marshes that characterize the area are keeping pace with sea level rise. Waccasassa Bay, an embayment within this region, also contains unique subtidal mudbanks that thicken with increasing proximity to embayment head, while the remainder of the bayfloor is characterized by exposed carbonate bedrock or by a thin veneer of sediment. Hydro- dynamic data sets were collected to determine the primary sedimentary processes within Waccasassa Bay capable of creating such geomorphic features. Data suggest that the embayment is a flood-dominated system influenced primarily by semi-diurnal tides with flood-stage intensification towards the river-mouth. Subtidal mudbanks are believed to be the result of tidal time-velocity asymmetries and the convergence of sediment transport pathways. Flood dominance for potential bedload transport suggests a gradual infilling of the bay interior for the short time scale of this study. With no mechanism for seaward transport, Waccasassa Bay can be considered a sediment sink for the remainder of the Big Bend re

  17. Late Wisconsin and early holocene glacial history, inner Ross Embayment, Antarctica

    NASA Technical Reports Server (NTRS)

    Denton, George H.; Bockheim, James G.; Wilson, Scott C.; Stuiver, Minze

    1991-01-01

    Lateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore, Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and younger (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000 to 13,000 yr B.P. Outlet glacier profiles from these drifts constrain late Wisconsin ice sheet surface elevations. Within these constraint, two extreme late Wisconsin reconstructions are given of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment, one reconstruction shows floating shelf ice, where as the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600 to 6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains.

  18. Three-dimensional long-period groundmotion simulations in the upper Mississippi embayment

    USGS Publications Warehouse

    Macpherson, K.A.; Woolery, E.W.; Wang, Z.; Liu, P.

    2010-01-01

    We employed a 3D velocity model and 3D wave propagation code to simulate long-period ground motions in the upper Mississippi embayment. This region is at risk from large earthquakes in the New Madrid seismic zone (NMSZ) and observational data are sparse, making simulation a valuable tool for predicting the effects of large events. We undertook these simulations to estimate the magnitude of shaking likely to occur and to investigate the influence of the 3D embayment structure and finite-fault mechanics on ground motions. There exist three primary fault zones in the NMSZ, each of which was likely associated with one of the main shocks of the 1811-12 earthquake triplet. For this study, three simulations have been conducted on each major segment, exploring the impact of different epicentral locations and rupture directions on ground motions. The full wave field up to a frequency of 0.5 Hz is computed on a 200 ?? 200 ?? 50-km 3 volume using a staggered-grid finite-difference code. Peak horizontal velocity and bracketed durations were calculated at the free surface. The NMSZ simulations indicate that for the considered bandwidth, finite-fault mechanics such as fault proximity, directivity effect, and slip distribution exert the most control on ground motions. The 3D geologic structure of the upper Mississippi embayment also influences ground motion with indications that amplification is induced by the sharp velocity contrast at the basin edge.

  19. Longitudinal Hydrodynamic Characteristics in Reservoir Tributary Embayments and Effects on Algal Blooms

    PubMed Central

    Dai, Huichao; Mao, Jingqiao; Jiang, Dingguo; Wang, Lingling

    2013-01-01

    Three Gorges Reservoir (TGR) is one of the largest man-made lakes in the world. Since the impoundment in 2003, however, algal blooms have been often observed in the tributary embayments. To control the algal blooms, a thorough understanding of the hydrodynamics (e.g., flow regime, velocity gradient, and velocity magnitude and direction) in the tributary embayments is particularly important. Using a calibrated three-dimensional hydrodynamic model, we carried out a hydrodynamic analysis of a typical tributary embayment (i.e., Xiangxi Bay) with emphasis on the longitudinal patterns. The results show distinct longitudinal gradients of hydrodynamics in the study area, which can be generally characterized as four zones: riverine, intermediate, lacustrine, and mainstream influenced zones. Compared with the typical longitudinal zonation for a pure reservoir, there is an additional mainstream influenced zone near the mouth due to the strong effects of TGR mainstream. The blooms are prone to occur in the intermediate and lacustrine zones; however, the hydrodynamic conditions of riverine and mainstream influence zones are not propitious for the formation of algal blooms. This finding helps to diagnose the sensitive areas for algal bloom occurrence. PMID:23874534

  20. Stratigraphy and structure along the Pensacola Arch/Conecuh Embayment margin in northwest Florida

    SciTech Connect

    Duncan, J.G. . Geology Dept. Florida Geological Survey, Tallahassee, FL )

    1993-03-01

    Stratigraphic and structural analysis of deep borehole data along the Pensacola Arch/Conecuh Embayment margin in eastern Santa Rosa County, Florida reveals a northeast-trending basement normal fault that is downthrown to the northwest. The fault functioned as a border fault of a half-graben (or graben ) that developed during continental rifting of Pangea in the Late Triassic and Early Jurassic. The upthrown or horst block was a paleotopographic high that formed the southeastern boundary of the Middle to Late Jurassic Conecuh Embayment. A second, younger basement fault trends approximately perpendicular to the half-graben border fault. Late Triassic synrift continental sediments, deposited on the downthrown block of the half-graben, pinch-out abruptly to the southeast pre-Mesozoic Suwannee Basin basement. The border fault is located approximately where the Triassic sedimentary wedge pinches out. Middle to Upper Jurassic drift-stage strata of the Conecuh embayment progressively onlap the post-rift unconformity toward the southeast. Upper Jurassic Smackover Formation carbonates and evaporites apparently overstep Triassic deposits and rest directly on Suwannee Basin quartzitic sandstone near their depositional limit at the Pensacola Arch. The Smackover Formation thins significantly toward the southeast in association with the Triassic pinch-out and half-graben border fault. The pinch-out trend of the Smackover Formation suggests a northeast-southwest orientation for the Triassic border fault and supports a horst-block origin for the Pensacola Arch.

  1. Treatise on seismicity and velocity structure of the northern Mississippi Embayment

    NASA Astrophysics Data System (ADS)

    Mostafanejad, Akramalsadat

    Seismicity of the New Madrid seismic zone, velocity structure of the northern Mississippi Embayment and extent of lithospheric discontinuities have been investigated in this work. Spatial variations of seismic b-value in the NMSZ have been determined. A region of high b-value (b˜1.8) in the northern segment of the Reelfoot fault has been found which reflects higher frequency in the occurrence rate of small earthquakes. This is attributed to fault creep in a medium with high silica content, high pore fluid pressure and extensive velocity heterogeneity. In another study, power spectral ratios of horizontal to vertical (H/V) and vertical to horizontal (V/H) components of teleseismic P-waves recorded by broadband seismic stations inside the Mississippi embayment have been examined to produce a 3-D average velocity map of the sediments. Fundamental resonance frequencies for S-wave reverberations in the northern Mississippi Embayment are about 0.2 to 0.4 Hz. Detailed linear gradient velocity models for Vp and Vs have also been calculated using teleseismic vertical and radial transfer functions at 60 broadband stations inside the Mississippi embayment and simultaneously inverting for velocity parameters. This led to a detailed 3-D linear gradient Vp and Vs model of the sediments for the first time. P-wave velocity starts at about 1.0 km/s near the surface and increases with depth to 3.5 to 4 km/s in deeper parts of the embayment. S-wave velocities vary from 0.3km/s to 1.6 km/s in deeper sections to the southwest. This detailed velocity structure of the unconsolidated sediments is developed so that it could be used to downward continue the transfer functions to the depth of 5 km to remove the effects of observed amplification, reverberation and large P-S conversions that occurs at the sediment-bedrock interface. The resulting waveforms are depth migrated to image the lateral and vertical changes of major reflectors with depth. The Moho boundary is observed with high

  2. Potentiometric Surface in the Sparta-Memphis Aquifer of the Mississippi Embayment, Spring 2007

    USGS Publications Warehouse

    Schrader, T.P.

    2008-01-01

    The most widely used aquifer for industry and public supply in the Mississippi embayment in Arkansas, Louisiana, Mississippi, and Tennessee is the Sparta-Memphis aquifer. Decades of pumping from the Sparta-Memphis aquifer have affected ground-water levels throughout the Mississippi embayment. Regional assessments of water-level data from the aquifer are important to document regional water-level conditions and to develop a broad view of the effects of ground-water development and management on the sustainability and availability of the region's water supply. This information is useful to identify areas of water-level declines, identify cumulative areal declines that may cross State boundaries, evaluate the effectiveness of ground-water management strategies practiced in different States, and identify areas with substantial data gaps that may preclude effective management of ground-water resources. A ground-water flow model of the northern Mississippi embayment is being developed by the Mississippi Embayment Regional Aquifer Study (MERAS) to aid in answering questions about ground-water availability and sustainability. The MERAS study area covers parts of eight states including Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee and covers approximately 70,000 square miles. The U.S. Geological Survey (USGS) and the Mississippi Department of Environmental Quality Office of Land and Water Resources measured water levels in wells completed in the Sparta-Memphis aquifer in the spring of 2007 to assist in the MERAS model calibration and to document regional water-level conditions. Measurements by the USGS and the Mississippi Department of Environmental Quality Office of Land and Water Resources were done in cooperation with the Arkansas Natural Resources Commission; the Arkansas Geological Survey; Memphis Light, Gas and Water; Shelby County, Tennessee; and the city of Germantown, Tennessee. In 2005, total water use from the Sparta

  3. Coastal evolution between two giant rivers: The Chan May embayment in central Vietnam

    NASA Astrophysics Data System (ADS)

    Gouramanis, C.; Switzer, A.; Bristow, C.; Pham, D. T.; Mauz, B.; Pile, J.; Doan, L. D.; Hoang, Q. D.; Ngo, C. K.; Dao, N.; Polivka, P.; Soria, L.; Lee, Y.; Sloss, C.; Hoang, L. V.

    2015-12-01

    The coastal landscapes of Vietnam are dominated in the north and south by the very large Red and Mekong rivers. Central Vietnam, in contrast, has few large rivers that flow to the coastal zone. This coupled with the high relief (>1500 m) of the granitic Truong Son Range and shallow gradient continental shelf, has produced two different coastal geomorphologies. The first is a shallow basin infilled with a sequence of parallel, arcuate beach ridges, and the second includes the development of shore-parallel spits and coastal lagoons. All systems are Holocene in age and we present evidence of the Holocene evolution of the northward-facing, beach ridge strandplain located in the Chan May embayment, approximately 35 km north of Danang. This embayment is relatively small (5 km long at the beach and with a beach ridge sequence that spans 11 km from the modern beach to the base of the Truong Son Range) compared to other beach ridge strandplains to the north and south and serves as an analogue for the evolution of these larger systems. The Holocene evolution of the embayment was resolved using Ground Penetrating Radar (GPR), high-resolution sedimentological analysis and quartz Optically Stimulated Luminescence were used to investigate the internal stratigraphy and chronological development of the beach ridges at Chan May. The strandplain contains uniform, clean quartz-rich sediment interspersed by thin heavy mineral rich bands forming shallow-gradient beach ridges that have steadily prograded seaward during the regression after the mid-Holocene sea level highstand. As the beach ridges prograded seaward, a small river feeding directly from the Truong Son Range meandered across the strandplain and significantly modified the embayment. Recently, the river has become much reduced due to anthropogenic modification of the river and landscape. Prior to the Holocene marine highstand, the area was similarly characterized by a surface of prograding beach ridges that were eroded by

  4. More CBE in Texas

    ERIC Educational Resources Information Center

    Sandoz, Ellis

    1977-01-01

    New accreditation regulations in Texas require competency-based education programs for all districts. All districts must be accredited to receive state aid, which makes up 85 cents of every dollar spent locally. (Author/IRT)

  5. Mapping giant reed along the Rio Grande using airborne and satellite imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed (Arundo donax L.) is a perennial invasive weed that presents a severe threat to agroecosystems and riparian areas in the Texas and Mexican portions of the Rio Grande Basin. The objective of this presentation is to give an overview on the use of aerial photography, airborne multispectral a...

  6. Estimating water use by giant reed along the Rio Grande River using a large aperture scintillometer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed (Arundo donax L.) is a bamboo-like perennial invasive weed from Eurasia presenting a severe threat to agroecosystems and riparian areas in Texas and Mexican portions of the Rio Grande River Basin. It is known to consume excessive amounts of water to support its rapid vegetative growth rat...

  7. Economic implications for the biological control of Arundo donax: Rio Grande Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed, Arundo donax L., is a large, bamboo-like plant native to the Mediterranean region. It has invaded several thousand hectares of the Rio Grande riparian habitat in Texas and Mexico. The United States Department of Agriculture-Agricultural Research Service (USDA-ARS) is investigating four...

  8. Economic implications for the biological control of Arundo donax: Rio Grande Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant reed, Arundo donax L., is a large bamboo-like plant native to the Mediterranean region. It has invaded several thousand hectares of the Rio Grande riparian habitat in Texas and Mexico. The United States Department of Agriculture-Agricultural Research Service (USDA-ARS) is investigating four ...

  9. Grand challenge problems in environmental modeling and remediation: groundwater contaminant transport

    SciTech Connect

    Todd Arbogast; Steve Bryant; Clint N. Dawson; Mary F. Wheeler

    1998-08-31

    This report describes briefly the work of the Center for Subsurface Modeling (CSM) of the University of Texas at Austin (and Rice University prior to September 1995) on the Partnership in Computational Sciences Consortium (PICS) project entitled Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport.

  10. Properties and chemical constituents in ground water from the lower Wilcox Aquifer, Mississippi Embayment Aquifer System, south-central United States

    USGS Publications Warehouse

    Pettijohn, Robert A.; Busby, John F.; Beckman, Jeffery D.

    1993-01-01

    The Gulf Coast Regional Aquifer-System Analysis is a study of regional aquifers composed of sediments of mostly Cenozoic age that underlie about 230,000 sq mi of the Gulf Coastal Plain. These regional aquifers are part of three aquifer systems: (1) the Mississippi Embayment Aquifer System, (2) the Texas Coastal Uplands Aquifer System, and (3) the Coastal Lowlands Aquifer System. The water chemistry of the Lower Wilcox Aquifer, which is part of the Mississippi Embayment Aquifer System is presented by a series of maps. These maps show the areal distribution of (1) the concentration of dissolved solids and temperature, (2) the primary water types and pH, (3) the concentration of major ions and silica, and (4) the milliequivalent ratios of selected ions. Dissolved constituents, pH, temperature, and ratios are based on the median values of all samples in each 100-sq-mi area. The concentration of dissolved solids in water from the Lower Wilcox Aquifer ranges from 18 mg/L near the outcrop in western Tennessee to 122,000 mg/L in a down-dip area in southern Mississippi. The primary water type is calcium bicarbonate in the outcrop area and sodium bicarbonate in all other areas of the aquifer within the limits of available data. The concentrations of major ions generally increase from the outcrop area to the down-dip limit of the data in the southern part of the aquifer area east of the Mississippi River. The milliequivalent ratio maps of selected ions in water from the Lower Wilcox Aquifer indicate some trends. The milliequivalent ratio of magnesium plus calcium to bicarbonate ranges from less than 0.1 to 40.4 and generally decreases from outcrop to down-dip limit of the data in the southern part of the aquifer area east of the Mississippi River. The milliequivalent ratio of bicarbonate to chloride ranges from 0.01 in southern Mississippi to 52.3 in northwestern Mississippi. This ratio increases from the outcrop toward the Mississippi River and from north to south in the

  11. Water-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, B.J.; Callender, Edward C.

    1997-01-01

    In 1991, the U.S. Geological Survey (USGS) began full implementation of the National Water-Quality Assessment (NAWQA) Program (Leahy and others, 1990). Also in 1991, the State of Texas established the Clean Rivers Program (CRP) administered by the Texas Natural Resource Conservation Commission (TNRCC). The coring study reported here was a collaborative effort between the NAWQA Program and the CRP Rio Grande Border Environmental Assessment Team, with additional funding support from the El Paso County Water Improvement District No. 1.

  12. NEHRP soil classifications for estimating site-dependent seismic coefficients in the Upper Mississippi Embayment

    USGS Publications Warehouse

    Street, R.; Woolery, E.W.; Wang, Z.; Harris, J.B.

    2001-01-01

    Local soil conditions have a profound influence on the characteristics of ground shaking during an earthquake. Exceptionally deep soil deposits, on the order of 100-1000 m deep, are found in the Upper Mississippi Embayment of the central United States. Shear waves (SH) from earthquakes in the New Madrid seismic zone are expected to be strongly affected by the sharp impedance contrasts at the bedrock/sediment interface, attenuation of seismic waves in the soil column, and the SH-wave velocities of the more poorly consolidated near-surface (???50 m) soils. SH-wave velocities of the near-surface soils at nearly 400 sites in the Upper Mississippi Embayment were determined using conventional seismic SH-wave refraction and reflection techniques. Based on the average SH-wave velocities of the upper 30 m of the soils, sites in the Mississippi River floodplain portion of the study area are predominantly classified as Site Class D (180-360 m/s) in accordance with the 1997 NEHRP provisions. Sites away from the active floodplains in western Kentucky and western Tennessee, the SH-wave velocities of the upper 30 m of soils typically ranged from mid-200 to mid-300 m/s. Several sites in western Kentucky had averaged SH-wave velocities greater than 360 m/s, thereby qualifying them as Site Class C (360-760 m/s) in accordance with the 1997 NEHRP provisions. One dimensional site effects, including amplification and dynamic site period, were calculated for a representative suite of sites across the Upper Mississippi Embayment at latitude ?? 38.5??. Although seismic attenuation is greater in the Mississippi River floodplain (i.e. thicker, lower velocity material), the site effects tend to be greater than in the uplands of western Tennessee because of larger impedance contrasts within the near-surface soils. ?? 2001 Elsevier Science B.V. All rights reserved.

  13. Intracaldera volcanic activity, Toledo caldera and embayment, Jemez Mountains, New Mexico

    SciTech Connect

    Heiken, G.; Goff, F.; Stix, J.; Shafiqullah, M.; Garcia, S.; Hagan, R.

    1986-02-10

    The Toledo caldera was formed at 1.47 +- 0.06 Ma during the catastrophic eruption of the lower member, Bandelier Tuff. The caldera was obscured at 1.12 +- 0.03 Ma during eruption of the equally voluminous upper member of the Bandelier Tuff that led to formation of the Valles caldera. Earlier workers interpreted a 9-km-diameter embayment, located NE of the Valles caldera (Toledo embayment), to be a remnant of the Toledo caldera. Drill hole data and new K-Ar dates of Toledo intracaldera domes redefine the position of Toledo caldera, nearly coincident with and of the same dimensions as the younger Valles caldera. the Toledo embayment may be of tectonic origin or a small Tschicoma volcanic center caldera. This interpretation is consistent with distribution of the lower member of the Bandelier Tuff and with several other field and drilling-related observations. Explosive activity associated with Cerro Toledo Rhyolite domes is recorded in tuff deposits located between the lower and upper members of the Bandelier Tuff on the northeast flank of the Jemez Mountains. Recorded in the tuff deposits are seven cycles of explosive activity. Most cycles consists of phreatomagmatic tuffs that grade upward into Plinian pumice beds. A separate deposit, of the same age and consisting of pyroclastic surges and flows, is associated with Rabbit Mountain, located on the southeast rim of the Valles-Toledo caldera complex. These are the surface expression of what may be a thicker, more voluminous intracaldera tuff sequence. The combined deposits of the lower and upper members of the Bandelier Tuff, Toledo and Valles intracaldera sediments, tuffs, and dome lavas form what we interpret to be a wedge-shaped caldera fill. This sequence is confirmed by deep drill holes and gravity surveys.

  14. Attributes and origins of ancient submarine slides and filled embayments: Examples from the Gulf Coast basin

    SciTech Connect

    Morton, R.A. )

    1993-06-01

    Large submarine slides and associated shelf margin embayments represent an intermediate member in the continuum of unstable shelf margin features. On seismic profiles, they may resemble submarine canyons, but are different in their size, morphology, origin, and hydrocarbon exploration potential. Two large Neogene submarine slides, located in the northwestern Gulf Coast Basin, formed on the upper slope and flanks of prominent shelf-margin deltas. The basal detachment surface of each slide is a structural discontinuity that may be misinterpreted as an erosional unconformity and misidentified as a stratigraphic boundary separating depositional sequences. Regional stratigraphic correlations indicate that both slides were initiated after the continental platform was flooded. The condensed sections deposited during the rise in relative sea level contain the basal detachment surfaces. The relationships between the slides and sea level fluctuations are uncertain. The shelf-margin embayments created by the slides apparently were partly excavated during periods of lowered relative sea level and were filled during sea level rise and highstand. Eventually the preslide morphology of the shelf margin was restored by coalsced prograding deltas. Submarine slides exhibit landward dipping, wavy, mounded, and chaotic seismic reflection that are manifestations of slump blocks and other mass transport material. Composition of these internally derived slide deposits depends on th composition of the pre-existing shelf margin. Embayment fill above the slide consists mostly of externally derived mudstones and sandstones deposited by various disorganized slope processes, as well as more organized submarine channel-level systems. Thickest slope sandstones, which are potential hydrocarbon reservoirs, commonly occur above the basal slide mudstones where seismic reflections change from chaotic patterns to overlying wavy or subhorizontal reflections. 46 refs., 10 figs., 1 tab.

  15. Attributes and origins of ancient submarine slides and filled embayments: examples from the Gulf Coast basin

    USGS Publications Warehouse

    Morton, Robert

    1993-01-01

    Submarine slides exhibit landward-dipping, wavy, mounded, and chaotic seismic reflections that are manifestations of slump blocks and other mass transport material. Composition of these internally derived slide deposits depends on the composition of the preexisting shelf margin. Embayment fill above the slide consists mostly of externally derived mudstones and sandstones deposited by various disorganized slope processes, as well as more organized submarine channel-levee systems. Thickest slope sandstones, which are potential hydrocarbon reservoirs, commonly occur above the basal slide mudstones where seismic reflections change from chaotic patterns to overlying wavy or subhorizontal reflections.

  16. Transverse section through the Grand Lodge and Grand Chapter rooms ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Transverse section through the Grand Lodge and Grand Chapter rooms of James H. Windrim and George Summers’s neoclassical competition design for the New Masonic Temple, Philadelphia, 1867 - Masonic Temple, 1 North Broad Street, Philadelphia, Philadelphia County, PA

  17. Detection of Rhynchophorus palmarum (Coleoptera: Curculionidae) and identification of associated nematodes in south Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports a survey conducted to find the South American palm weevil Rhynchophorus palmarum (L.) and the red palm weevil R. ferrugineus (Olivier) (Coleoptera: Curculionidae), two invasive species of palm trees. The study was performed in the Rio Grande Valley of south Texas and near the bor...

  18. Isaria poprawskii sp. nov. (Hypocreales: Cordycipitacae), a new entomopathogenic fungus from Texas affecting sweet potato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isaria poprawskii is described as a new entomopathogenic species similar to Isaria javanica (=Paecilomyces javanicus). It was discovered ont he sweet potato whitefly, Bemisia tabaci biotype B in the Lower Rio Grande Valley of Texas (LRGV), USA. Morphological and DNA examinations indicated the dist...

  19. Texas State Technical College Review.

    ERIC Educational Resources Information Center

    Aumack, Bruce; Blake, Larry J.

    Texas educational legislation for 1991 required the Texas Higher Education Coordinating Board (THECB) to review the operations of, and the continuing need for, each of the four main campuses and five extension centers of the Texas State Technical College System (TSTCS), and to make recommendations concerning the facilities' continuation and/or…

  20. A GRAND affair

    NASA Astrophysics Data System (ADS)

    tima2014; tomandersen; mugundhan; toadgreen

    2015-10-01

    In reply to the physicsworld.com news story “GRAND plans for new neutrino observatory”, which called for a new detector made up of hundreds of thousands of antennas spread over an area slightly smaller than the UK (18 August, http://owl.ly/R5N6u).

  1. Democracy and "Grand" Corruption.

    ERIC Educational Resources Information Center

    Rose-Ackerman, Susan

    1996-01-01

    Defines "grand" corruption as that occurring at the higher levels of a political system and involving large sums of money. Discusses the impact and incentives for this level of corruption as well as various government responses. Identifies multinational corporations as the major malefactors. (MJP)

  2. A SIMPLIFIED MODELING OF FLUSHING AND RESIDENCE TIME IN 42 EMBAYMENTS IN NEW ENGLAND, USA, WITH SPECIAL ATTENTION TO GRENWICH BAY, RHODE ISLAND

    EPA Science Inventory

    A simplified protocol has been developed to meet the need for modeling hydrodynamics and transport in large numbers of embayments quickly and reliably. The procedure is illustrated with 42 embayments in southern New England, USA, giving special attention to Greenwich Bay, RI. The...

  3. Paleocene to Middle Miocene planktic foraminifera of the southwestern Salisbury Embayment, Virginia and Maryland: biostratigraphy, allostratigraphy, and sequence stratigraphy

    USGS Publications Warehouse

    Poag, C.W.; Commeau, J.A.

    1995-01-01

    The Paleocene to Middle Miocene sedimentary fill of the southwestern Salisbury Embayment contains a fragmental depositional record, interrupted by numerous local diastems and regional unconformities. Using planktic foraminiferal biostratigraphy, 15 unconformity-bounded depositional units have been identified, assigned to six formations and seven alloformations previously recognized in the embayment. The units correlate with second- and third-order sequences of the Exxon sequence stratigraphy model, and include transgressive and highstand systems tracts. Alloformation, formation, and sequence boundaries are marked by abrupt, scoured, burrowed, erosional surfaces, which display lag deposits, biostratigraphic gaps, and intense reworking of microfossils above and below the boundaries. -from Authors

  4. Spatial and temporal trends in summertime climate and water quality indicators in the coastal embayments of Buzzards Bay, Massachusetts

    NASA Astrophysics Data System (ADS)

    Rheuban, J. E.; Williamson, S.; Costa, J. E.; Glover, D. M.; Jakuba, R. W.; McCorkle, D. C.; Neill, C.; Williams, T.; Doney, S. C.

    2016-01-01

    Degradation of coastal ecosystems by eutrophication is largely defined by nitrogen loading from land via surface water and groundwater flows. However, indicators of water quality are highly variable due to a myriad of other drivers, including temperature and precipitation. To evaluate these drivers, we examined spatial and temporal trends in a 22-year record of summer water quality data from 122 stations in 17 embayments within Buzzards Bay, MA (USA), collected through a citizen science monitoring program managed by Buzzards Bay Coalition. To identify spatial patterns across Buzzards Bay's embayments, we used a principle component and factor analysis and found that rotated factor loadings indicated little correlation between inorganic nutrients and organic matter or chlorophyll a (Chl a) concentration. Factor scores showed that embayment geomorphology in addition to nutrient loading was a strong driver of water quality, where embayments with surface water inputs showed larger biological impacts than embayments dominated by groundwater influx. A linear regression analysis of annual summertime water quality indicators over time revealed that from 1992 to 2013, most embayments (15 of 17) exhibited an increase in temperature (mean rate of 0.082 ± 0.025 (SD) °C yr-1) and Chl a (mean rate of 0.0171 ± 0.0088 log10 (Chl a; mg m-3) yr-1, equivalent to a 4.0 % increase per year). However, only seven embayments exhibited an increase in total nitrogen (TN) concentration (mean rate 0.32 ± 0.47 (SD) µM yr-1). Average summertime log10(TN) and log10(Chl a) were correlated with an indication that the yield of Chl a per unit total nitrogen increased with time suggesting the estuarine response to TN may have changed because of other stressors such as warming, altered precipitation patterns, or changing light levels. These findings affirm that nitrogen loading and physical aspects of embayments are essential in explaining the

  5. Spatial and temporal trends in summertime climate and water quality indicators in the coastal embayments of Buzzards Bay, Massachusetts

    NASA Astrophysics Data System (ADS)

    Rheuban, J. E.; Williamson, S. C.; Costa, J. E.; Glover, D. M.; Jakuba, R. W.; McCorkle, D. C.; Neill, C.; Williams, T.; Doney, S. C.

    2015-08-01

    Degradation of coastal ecosystems by eutrophication is largely defined by nitrogen loading from land via surface and groundwater flows. However, indicators of water quality are highly variable due to a myriad of other drivers, including temperature and precipitation. To evaluate these drivers, we examined spatial and temporal trends in a 22 year record of summer water quality data from 122 stations in 17 embayments within Buzzards Bay, MA (USA), collected through a citizen science monitoring program managed by Buzzards Bay Coalition. To identify spatial patterns across Buzzards Bay's embayments, we used a principle component and factor analysis and found that rotated factor loadings indicated little correlation between inorganic nutrients and organic matter and chlorophyll a (Chl a) concentration. Factor scores showed that embayment geomorphology in addition to nutrient loading was a strong driver of water quality, where embayments with surface water inputs showed larger biological impacts than embayments dominated by groundwater influx. A linear regression analysis of annual summertime water quality indicators over time revealed that from 1992 to 2013, most embayments (15 of 17) exhibited an increase in temperature (mean rate of 0.082 ± 0.025 (SD) °C yr-1) and Chl a (mean rate of 0.0171 ± 0.0088 log10 (Chl a; mg m-3) yr-1, equivalent to a 4.0 % increase per year). However, only 7 embayments exhibited an increase in total nitrogen (TN) concentration (mean rate 0.32 ± 0.47 (SD) μM yr-1). Average summertime log10 (TN) and log10 (Chl a) were correlated with an indication that yield of Chl a per unit total nitrogen increased with time suggesting the estuarine response to TN may have changed because of other stressors such as warming, altered precipitation patterns, or changing light levels. These findings affirm that nitrogen loading and physical aspects of embayments are essential in explaining observed ecosystem response. However, climate-related stressors may

  6. NanoSIMS results from olivine-hosted melt embayments: Magma ascent rate during explosive basaltic eruptions

    NASA Astrophysics Data System (ADS)

    Lloyd, Alexander S.; Ruprecht, Philipp; Hauri, Erik H.; Rose, William; Gonnermann, Helge M.; Plank, Terry

    2014-08-01

    The explosivity of volcanic eruptions is governed in part by the rate at which magma ascends and degasses. Because the time scales of eruptive processes can be exceptionally fast relative to standard geochronometers, magma ascent rate remains difficult to quantify. Here we use as a chronometer concentration gradients of volatile species along open melt embayments within olivine crystals. Continuous degassing of the external melt during magma ascent results in diffusion of volatile species from embayment interiors to the bubble located at their outlets. The novel aspect of this study is the measurement of concentration gradients in five volatile elements (CO2, H2O, S, Cl, F) at fine-scale (5-10 μm) using the NanoSIMS. The wide range in diffusivity and solubility of these different volatiles provides multiple constraints on ascent timescales over a range of depths. We focus on four 100-200 μm, olivine-hosted embayments erupted on October 17, 1974 during the sub-Plinian eruption of Volcán de Fuego. H2O, CO2, and S all decrease toward the embayment outlet bubble, while F and Cl increase or remain roughly constant. Compared to an extensive melt inclusion suite from the same day of the eruption, the embayments have lost both H2O and CO2 throughout the entire length of the embayment. We fit the profiles with a 1-D numerical diffusion model that allows varying diffusivities and external melt concentrations as a function of pressure. Assuming a constant decompression rate from the magma storage region at approximately 220 MPa to the surface, H2O, CO2 and S profiles for all embayments can be fit with a relatively narrow range in decompression rates of 0.3-0.5 MPa/s, equivalent to 11-17 m/s ascent velocity and an 8 to 12 minute duration of magma ascent from ~ 10 km depth. A two stage decompression model takes advantage of the different depth ranges over which CO2 and H2O degas, and produces good fits given an initial stage of slow decompression (0.05-0.3 MPa/s) at high

  7. Tectonic development of the New Madrid rift complex, Mississippi embayment, North America

    NASA Astrophysics Data System (ADS)

    Braile, Lawrence W.; Hinze, William J.; Keller, G. Randy; Lidiak, Edward G.; Sexton, John L.

    1986-11-01

    Geological and geophysical studies of the New Madrid Seismic Zone have revealed a buried late Precambrian rift beneath the upper Mississippi Embayment area. The rift has influenced the tectonics and geologic history of the area since late Precambrian time and is presently associated with the contemporary earthquake activity of the New Madrid Seismic Zone. The rift formed during late Precambrian to earliest Cambrian time as a result of continental breakup and has been reactivated by compressional or tensional stresses related to plate tectonic interactions. The configuration of the buried rift is interpreted from gravity, magnetic, seismic refraction, seismic reflection and stratigraphic studies. The increased mass of the crust in the rift zone, which is reflected by regional positive gravity anomalies over the upper Mississippi Embayment area, has resulted in periodic subsidence and control of sedimentation and river drainage in this cratonic region since formation of the rift complex. The correlation of the buried rift with contemporary earthquake activity suggests that the earthquakes result from slippage along zones of weakness associated with the ancient rift structures. The slippage is due to reactivation of the structure by the contemporary, nearly E-W regional compressive stress which is the result of plate motions.

  8. Transient simulations of nitrogen load for a coastal aquifer and embayment, Cape Cod, MA

    USGS Publications Warehouse

    Colman, J.A.; Masterson, J.P.

    2008-01-01

    A time-varying, multispecies, modular, three-dimensional transport model (MT3DMS) was developed to simulate groundwater transport of nitrogen from increasing sources on land to the shore of Nauset Marsh, a coastal embayment of the Cape Cod National Seashore. Simulated time-dependent nitrogen loads at the coast can be used to correlate with current observed coastal eutrophic effects, to predict current and ultimate effects of development, and to predict loads resulting from source remediation. A time-varying nitrogen load, corrected for subsurface loss, was applied to the land subsurface in the transport model based on five land-use coverages documenting increasing development from 1951 to 1999. Simulated nitrogen loads to Nauset Marsh increased from 230 kg/yr before 1930 to 4390 kg/yr in 2001 to 7130 kg/yr in 2100, assuming future nitrogen sources constant at the 1999 land-use rate. The simulated nitrogen load per area of embayment was 5 times greater for Salt Pond, a eutrophic landward extension of Nauset Marsh, than for other Nauset Marsh areas. Sensitivity analysis indicated that load results were little affected by changes in vertical discretization and annual recharge but much affected by the nitrogen loss rate assumed for a kettle lake downgradient from a landfill.

  9. Lithospheric structure beneath northern Mississippi embayment from joint inversion of surface wave dispersion and receiver functions

    NASA Astrophysics Data System (ADS)

    Su, Han

    The northern Mississippi Embayment is characterized by relatively high seismicity at the New Madrid Seismic Zone. Although many studies have focused on specific earthquakes or on the structure at specific locations, the mechanism of the earthquake process has remained an enigma. As part of the Northern Embayment Lithosphere Experiment, we focus on high resolution surface-wave tomography of Love and Rayleigh, phase and group velocities for a study region bounded by 34-40 N latitude and 85-94 W longitude for periods from 2 to 50 seconds by cross-correlating ambient noise from BH channels of the Transportable Array of EarthScope. To test the usefulness of the dispersion, we perform a joint inversion of dispersion and teleseismic P-wave receiver functions for stations in the region. At a few locations, we are able to test the resulting models by comparing predicted to observed broadband recordings of local earthquakes. At these few locations, we find good agreement and also evidence that the Moho is a gradient rather than a sharp discontinuity.

  10. Petroleum system evolution in the Conecuh Embayment southwest Alabama U.S. Gulf Coast

    SciTech Connect

    Wade, W.J. |

    1996-09-01

    Analyses of hydrocarbon maturation trends in Smackover reservoirs of southwest Alabama indicates that crude oils in updip reservoirs of the Conecuh Embayment are anomalously mature for their present temperature-depth regimes. It is inferred that these mature oils equilibrated to depth-temperature conditions in deeper reservoirs downdip, and subsequently remigrated to their present positions. Burial history reconstructions, regional structure, and reservoir distributions support a model in which these mature oils leaked from the Jay-Flomaton-Big Escambia Creek field complex during Tertiary time, migrated through the Norphlet Formation, and accumulated in updip Smackover and Haynesville traps associated with basement knobs. Geochemical evidence suggests that hydrocarbon leakage from the Jay-Flomaton-Big Escambia Creek complex may have been triggered by an influx of very mature gas condensates with high non-hydrocarbon gas contents from failed reservoirs still farther downdip. This scenario has potential implications for (1) predicting potential migration pathways and preferential areas of crude oil accumulation in the updip portions of the Conecuh Embayment; and (2) reinterpreting organic-inorganic burial diagenetic reactions in the Norphlet Formation reservoirs of offshore Mobile Bay.

  11. A joint local and teleseismic tomography study of the Mississippi Embayment and New Madrid Seismic Zone

    NASA Astrophysics Data System (ADS)

    Nyamwandha, Cecilia A.; Powell, Christine A.; Langston, Charles A.

    2016-05-01

    Detailed, upper mantle P and S wave velocity (Vp and Vs) models are developed for the northern Mississippi Embayment (ME), a major physiographic feature in the Central United States (U.S.) and the location of the active New Madrid Seismic Zone (NMSZ). This study incorporates local earthquake and teleseismic data from the New Madrid Seismic Network, the Earthscope Transportable Array, and the FlexArray Northern Embayment Lithospheric Experiment stations. The Vp and Vs solutions contain anomalies with similar magnitudes and spatial distributions. High velocities are present in the lower crust beneath the NMSZ. A pronounced low-velocity anomaly of ~ -3%--5% is imaged at depths of 100-250 km. High-velocity anomalies of ~ +3%-+4% are observed at depths of 80-160 km and are located along the sides and top of the low-velocity anomaly. The low-velocity anomaly is attributed to the presence of hot fluids upwelling from a flat slab segment stalled in the transition zone below the Central U.S.; the thinned and weakened ME lithosphere, still at slightly higher temperatures from the passage of the Bermuda hotspot in mid-Cretaceous, provides an optimal pathway for the ascent of the fluids. The observed high-velocity anomalies are attributed to the presence of mafic rocks emplaced beneath the ME during initial rifting in the early Paleozoic and to remnants of the depleted, lower portion of the lithosphere.

  12. Microphytobenthos potential productivity estimated in three tidal embayments of the San Francisco Bay system

    USGS Publications Warehouse

    Guarini, Jean-Marc; Cloern, James E.; Edmunds, Jody L.; Gros, Philippe

    2002-01-01

    In this paper we describe a three-step procedure to infer the spatial heterogeneity in microphytobenthos primary productivity at the scale of tidal estuaries and embayments. The first step involves local measurement of the carbon assimilation rate of benthic microalgae to determine the parameters of the photosynthesis-irradiance (P-E) curves (using non-linear optimization methods). In the next step, a resampling technique is used to rebuild pseudo-sampling distributions of the local productivity estimates; these provide error estimates for determining the significance level of differences between sites. The third step combines the previous results with deterministic models of tidal elevation and solar irradiance to compute mean and variance of the daily areal primary productivity over an entire intertidal mudflat area within each embayment. This scheme was applied on three different intertidal mudflat regions of the San Francisco Bay estuary during autumn 1998. Microphytobenthos productivity exhibits strong (ca. 3-fold) significant differences among the major sub-basins of San Francisco Bay. This spatial heterogeneity is attributed to two main causes: significant differences in the photosynthetic competence (P-E parameters) of the microphytobenthos in the different sub-basins, and spatial differences in the phase shifts between the tidal and solar cycles controlling the exposure of intertidal areas to sunlight. The procedure is general and can be used in other estuaries to assess the magnitude and patterns of spatial variability of microphytobenthos productivity at the level of the ecosystems.

  13. Microphytobenthic potential productivity estimated in three tidal embayments of the San Francisco Bay: A comparative study

    USGS Publications Warehouse

    Guarini, J.-M.; Cloern, James E.; Edmunds, J.

    2002-01-01

    In this paper we describe a three-step procedure to infer the spatial heterogeneity in microphytobenthos primary productivity at the scale of tidal estuaries and embayments. The first step involves local measurement of the carbon assimilation rate of benthic microalgae to determine the parameters of the photosynthesis-irradiance (P-E) curves (using non-linear optimization methods). In the next step, a resampling technique is used to rebuild pseudo-sampling distributions of the local productivity estimates; these provide error estimates for determining the significance level of differences between sites. The third step combines the previous results with deterministic models of tidal elevation and solar irradiance to compute mean and variance of the daily areal primary productivity over an entire intertidal mudflat area within each embayment. This scheme was applied on three different intertidal mudflat regions of the San Francisco Bay estuary during autumn 1998. Microphytobenthos productivity exhibits strong (ca. 3-fold) significant differences among the major sub-basins of San Francisco Bay. This spatial heterogeneity is attributed to two main causes: significant differences in the photosynthetic competence (P-E parameters) of the microphytobenthos in the different sub-basins, and spatial differences in the phase shifts between the tidal and solar cycles controlling the exposure of intertidal areas to sunlight. The procedure is general and can be used in other estuaries to assess the magnitude and patterns of spatial variability of microphytobenthos productivity at the level of the ecosystems.

  14. Chemical Contamination of the Lower Rio Grande near Laredo, TX

    NASA Astrophysics Data System (ADS)

    Flores, B.; Ren, J.; Krishnamurthy, S.; Belzer, W.

    2006-12-01

    The Rio Grande River stretches over 2000 miles from the southern Rocky Mountains in Colorado to the tip of Texas where the Rio Grande meets the Gulf of Mexico. It is the natural boundary between U.S. and Mexico from El Paso, TX, to Brownsville, TX. The communities along the border heavily rely upon the Rio Grande as a primary source of water for consumption, agricultural uses, supporting wildlife and recreation. For many years the Rio Grande has been polluted with municipal, industrial, agricultural and farming contaminants from both sides of the border. This pollution has led to the extinction or reduction of certain wildlife species as well as affecting the health of the residences along the border. Even though great strides have been made in monitoring the Rio Grande, there has been a lack of intense monitoring data collection for pollutants such as pesticides. Three sampling sites including Manadas Creek, the Rio Grande River at International Bridge I, and USGS monitoring site 08459200 off of Highway 83 were chosen. The water quality parameters focused include temperature, pH, conductivity, dissolve oxygen (DO), salinity, total dissolved solids, nutrients, metals and pesticides. Preliminary results have shown elevated concentration of total phosphorus and ortho-phosphorus in the Manadas Creek site. Organochlorinated pesticides such as heptachlor and 4, 4 DDE were detected at various concentrations at all sites and endrin aldehyde was found at Manadas Creek site. This research has provided more information on the current chemical contamination level of the Rio Grande in the Laredo area.

  15. Public water supplies in southern Texas

    USGS Publications Warehouse

    Broadhurst, W.L.; Sundstrom, R.W.; Rowley, J.H.

    1950-01-01

    This report gives a summarized description of the public water supplies in 42 counties of southern Texas, extending from the Rio Grande northward to the northern boundaries of Kinney, Uvalde, Bandera, Kendall, and Hays Counties and eastward to the eastern boundaries of Caldwell, Gonzales, DeWitt, Victoria, and Calhoun Counties. It gives the available data as follows for each of the 114 communities: Population of the community; name of the official from whom the information was obtained; ownership of water works, whether private or municipal; source of supply, whether ground or surface water; the amount of water consumed; the facilities for storage; the number of customers served; the character of the chemical and sanitary treatment, if any; and chemical analyses of the water. Where ground water is used, the following information also is given: Records of wells, including drillers' logs; character of the pumping equipment; yield of the wells and records of water levels, where they are available.

  16. Outdoor Education in Texas.

    ERIC Educational Resources Information Center

    Myers, Ray H.

    In Dallas in 1970, high school outdoor education began as a cocurricular woods and waters boys' club sponsored by a community sportsman. Within one year, it grew into a fully accredited, coeducational, academic course with a curriculum devoted to the study of wildlife in Texas, ecology, conservation, hunting, firearm safety, fishing, boating and…

  17. Texas Hunter Education Manual.

    ERIC Educational Resources Information Center

    Hall, Steve

    This handbook serves as a reference for the mandatory hunter education course in Texas. The "Introduction" explains hunter education's goal to produce safe, knowledgeable, responsible, and informed hunters. It also gives information related to hunting opportunities, administration, and management. Chapter 2, "Our Hunting…

  18. The Woodlands, Texas.

    ERIC Educational Resources Information Center

    McHaney, Larry J.; Bernhardt, Jerry

    1988-01-01

    The authors describe the "central project" concept for implementing technology education while addressing education reform. The central project is a topic around which students, teachers, administrators, and the community focus their energies as a team. At McCullough High School (Texas), the central project involved design and…

  19. Texas Migrant Council, Inc.

    ERIC Educational Resources Information Center

    Villarreal, Oscar L.

    Operating various programs, the Texas Migrant Council, a multi-service agency, administers assistance to migrants during their stay in their home base state, as well as on their migrant trek. Its Head Start program serves mobile migrant children from the ages of 0 to 5 and gives continuity of services by following them to the northern states…

  20. Library Laws of Texas.

    ERIC Educational Resources Information Center

    Seidenberg, Ed, Ed.

    Compiled to provide a central reference point for all legislative information pertaining to libraries in the state of Texas, this publication includes all pertinent legislation as amended through the 66th Legislature, Regular Session, 1979. It contains articles dealing specifically with archives, buildings and property, city libraries, non-profit…

  1. Library Laws of Texas.

    ERIC Educational Resources Information Center

    Getz, Richard E., Comp.

    Compiled to provide a central reference point for all legislative information pertaining to libraries in the State of Texas, this publication includes all pertinent legislation as amended through the 71st Legislature, 1989, Regular Session. This update of the 1980 edition has been expanded to include statutes pertaining to the school and academic…

  2. Texas-Oklahoma

    Atmospheric Science Data Center

    2014-05-15

    ... major geographic features. The south bank of the Red River marks the boundary between Texas and Oklahoma. Traversing brush-covered ... flow eastward, their waters eventually discharging into the Mississippi River. A smoke plume to the north of the Ouachita Mountains and ...

  3. East Texas Quilts.

    ERIC Educational Resources Information Center

    Whiteside, Karen, Ed.

    1986-01-01

    Patchwork quilting is an original folk art in the United States. Pilgrims first used worn out scraps of cloth to make bed covers in an age of scarcity. Featured here are stories on East Texas Quilts, their origins, the love and hard work which goes into the making of a quilt (Ira Barr and others). The techniques needed to construct a quilt are…

  4. Texas Irrigation Situation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The irrigation situation in Texas is an interaction between hydrology and water policies. In 2012, according to National Agricultural Statistical Service (NASS) four High Plains counties, Gainesville, Yoakum, Terry and Cochran, accounted for approximately 60% of the 150,000 acres of peanut productio...

  5. Texas and SREB

    ERIC Educational Resources Information Center

    Southern Regional Education Board (SREB), 2009

    2009-01-01

    The Southern Regional Education Board (SREB) is a nonprofit organization that works collaboratively with Texas and 15 other member states to improve education at every level--from pre-K to postdoctoral study--through many effective programs and initiatives. SREB's "Challenge to Lead" Goals for Education, which call for the region to lead…

  6. Tornado from Texas.

    ERIC Educational Resources Information Center

    Vail, Kathleen

    1996-01-01

    Santa Fe School Superintendent Yvonne Gonzales, the "Texas Tornado," was hired to fix a 40% student-dropout rate and a white/Hispanic gap in achievement test scores. Gonzales is an avid integrationist; relies on humor, appeasement, and persuasion tactics; and has alienated some school employees by increasing central office…

  7. Summary of records of surface waters of Texas, 1898-1937

    USGS Publications Warehouse

    Ellsworth, Clarence E.

    1939-01-01

    The first gaging station In Texas urns established on the Rio Grande at El Paso on May 10, 1889, under the provisions of the Act of Congress of October 2, 1888, which authorized the organization of the Irrigation Survey by the United States Geological Survey. A few miscellaneous measurements of streams In central Texas, between Del Rio and Austin, were made, by C. C. Babb of the Geological Survey in 1894, 1895, and 1896. In 1897 T. U. Taylor, professor of civil engineering at the University of Texas, at Austin, began a systematic study for the Geological Survey of as many of the principal streams as the limited funds would permit. In the same year the American section of the International Water Commission began collecting records of flow of the Rio Grande in Texas. Records for the Rio Grande and some of its tributaries from 1897 to 1913, inclusive, collected by that commission under the immediate direction of W. W. Follett, United States consulting engineer, are contained in Geological Survey Water-supply Paper 358. It was not until 1915, when the State Legislature appropriated funds for stream measurement investigations by the Texas Board of Water Engineers, that a substantial beginning toward the systematic collection of stream-flow records was made. The work has been continued and enlarged gradually so that records have been collected at about 230 stations in Texas. In September 1937 86 gaging stations were being maintained in Texas by the Geological Survey and the cooperating agencies. Many miscellaneous discharge measurements have been made at other points. The records collected by the Geological Survey from 1889 to 1937 are now scattered through more than 50 reports, many of which are out of print.

  8. Seismic anisotropy of the Rio Grande Rift and surrounding regions

    NASA Astrophysics Data System (ADS)

    Pulliam, J.; Rockett, C. V.; Grand, S. P.

    2009-12-01

    The Rio Grande Rift, located between the Colorado Plateau and the Great Plains, has a complex tectonic history comprised of two distinct phases in the Cenozoic era. An early stage of rifting began in the mid-Oligocene (~30 Ma) and lasted until the early Miocene (~18 Ma), followed by a lull and then an apparent reactivation along previous zones of weakness during a separate extension event in the late Miocene (~10 Ma), which continues today. The rift now extends more than 1000 km in length, trending north-south from Southern Colorado through New Mexico and Western Texas and into Chihuahua, Mexico. Structure of the rift is complex due to its multiple events of extension. The LA RISTRA seismic study (1999-2006) deployed broadband seismographs on a transect from Texas to Utah to investigate the structure and processes that control the Rift. Among other results, they found distinct differences in orientation of the fast polarization direction, as measured from SKS splitting, in the three main regions: the Colorado Plateau, the Rio Grande Rift, and the Great Plains. In 2008 71 EarthScope FlexArray stations were installed between Transportable Array stations to form a broad 2D deployment on the eastern flank of the RGR in southeastern New Mexico and western Texas as part of the SIEDCAR (Seismic Investigation of Edge Driven Convection Associated with the Rio Grande Rift) study. SKS splitting measurements from these, as well as from TA stations in the vicinity, show a more complex 2D pattern, but one which conforms with variations in crustal thickness and velocity anomalies in the uppermost mantle. We will report on these measurements and their implications for the style of convection associated with the RGR.

  9. Catalogue of Texas spiders

    PubMed Central

    Dean, David Allen

    2016-01-01

    Abstract This catalogue lists 1,084 species of spiders (three identified to genus only) in 311 genera from 53 families currently recorded from Texas and is based on the “Bibliography of Texas Spiders” published by Bea Vogel in 1970. The online list of species can be found at http://pecanspiders.tamu.edu/spidersoftexas.htm. Many taxonomic revisions have since been published, particularly in the families Araneidae, Gnaphosidae and Leptonetidae. Many genera in other families have been revised. The Anyphaenidae, Ctenidae, Hahniidae, Nesticidae, Sicariidae and Tetragnathidae were also revised. Several families have been added and others split up. Several genera of Corinnidae were transferred to Phrurolithidae and Trachelidae. Two genera from Miturgidae were transferred to Eutichuridae. Zoridae was synonymized under Miturgidae. A single species formerly in Amaurobiidae is now in the Family Amphinectidae. Some trapdoor spiders in the family Ctenizidae have been transferred to Euctenizidae. Gertsch and Mulaik started a list of Texas spiders in 1940. In a letter from Willis J. Gertsch dated October 20, 1982, he stated “Years ago a first listing of the Texas fauna was published by me based largely on Stanley Mulaik material, but it had to be abandoned because of other tasks.” This paper is a compendium of the spiders of Texas with distribution, habitat, collecting method and other data available from revisions and collections. This includes many records and unpublished data (including data from three unpublished studies). One of these studies included 16,000 adult spiders belonging to 177 species in 29 families. All specimens in that study were measured and results are in the appendix. Hidalgo County has 340 species recorded with Brazos County at 323 and Travis County at 314 species. These reflect the amount of collecting in the area. PMID:27103878

  10. Asymptotically safe grand unification

    NASA Astrophysics Data System (ADS)

    Bajc, Borut; Sannino, Francesco

    2016-12-01

    Phenomenologically appealing supersymmetric grand unified theories have large gauge representations and thus are not asymptotically free. Their ultraviolet validity is limited by the appearance of a Landau pole well before the Planck scale. One could hope that these theories save themselves, before the inclusion of gravity, by generating an interacting ultraviolet fixed point, similar to the one recently discovered in non-supersymmetric gauge-Yukawa theories. Employing a-maximization, a-theorem, unitarity bounds, as well as positivity of other central charges we nonperturbatively rule out this possibility for a broad class of prime candidates of phenomenologically relevant supersymmetric grand unified theories. We also uncover candidates passing these tests, which have either exotic matter or contain one field decoupled from the superpotential. The latter class of theories contains a model with the minimal matter content required by phenomenology.

  11. Relative persistence and dispersal of age-0 and age-1 largemouth bass stocked into two Ohio River embayments

    USGS Publications Warehouse

    Hartman, K.J.; Janney, E.C.

    2006-01-01

    In October of 1998 the West Virginia Division of Natural Resources stocked age-0 [mean total length (MTL) = 178 mm] and age-1 (MTL = 273 mm) hatchery-reared largemouth bass into two embayments of the Ohio River. Stocked fish were fitted with both an anchor tag and a visible implant elastomer mark. A multifaceted sampling approach was undertaken to (1) evaluate the persistence of stocked largemouth bass, (2) estimate fidelity of stocked largemouth bass to release sites, and (3) compare return rates of the two age classes. Although stocked largemouth bass comprised the majority (81%) of all bass captured in electrofishing surveys of the stocked embayments during fall 1998, catches declined rapidly during winter 1998, and by spring and summer 1999 stocked largemouth bass were virtually absent from electrofishing surveys. Creel surveys indicated no catch of stocked largemouth bass in the release sites after winter 1998. Electrofishing surveys, creel surveys, and angler call-ins all suggested stocked fish did not persist and either moved out of the stocked embayments or died. The results suggest that stocking advanced-size largemouth bass into these embayments only provided a limited and short-term enhancement of the fishery in those areas.

  12. Petrologic model of the northern Mississippi Embayment based on satellite magnetic and ground-based geophysical data

    NASA Technical Reports Server (NTRS)

    Thomas, H. H.

    1984-01-01

    A petrologic model of the northern Mississippi Embayment, derived from gravity, seismic and rift data, is evaluated by converting the model to a magnetization model which is compared with satellite magnetic anomaly models. A magnetization contrast of approximately -0.54 A/m, determined from the petrologic model of the embayment compares favorably to values of -0.62 A/m and -0.45 A/m from a Magsat United States Apparent Magnetization Contrast Map and a published POGO magnetization contrast model, respectively. The petrologic model suggests that the magnetic anomaly low associated with the Mississippi Embayment may be largely due to the intrusion under non-oxidizing conditions of low Curie temperature gabbroic material at the base of the crust of the embayment. Near-surface mafic plutons, bordering the Mississippi Valley Graben, appear from aeromagnetic data to have higher magnetizations than the deeper gabbroic material; however, it is impossible to ascertain if this is due to compositional differences or similar material at shallower (lower temperature) depths. These results indicate that variations in the Curie temperatures of intrusions accompanying rifting may account for a large part of the wide range of magnetic anomalies associated with presently inactive rifts with normal heat flow.

  13. PROPOSED USE OF LENGTH ALONG SHORELINE OF EELGRASS BEDS AS A MEASURE OF SUBMERGED AQUATIC VEGETATION (SAV) IN EMBAYMENTS

    EPA Science Inventory

    The U.S. EPA's Atlantic Ecology Division (AED) has a multi-year research program to develop empirical nitrogen load-response models for embayments in southern New England. This research program is part of EPA's Aquatic Stressors Program, which is designed to provide managers with...

  14. Ascent Rates from Melt Embayments: Insights into the Eruption Dynamics of Arc Volcanoes

    NASA Astrophysics Data System (ADS)

    Ruprecht, P.; Lloyd, A. S.; Hauri, E.; Rose, W. I.; Gonnermann, H. M.; Plank, T. A.

    2014-12-01

    A significant fraction of the magma that is added from the mantle to the subvolcanic plumbing system ultimately erupts at the surface. The initial volatile content of the magmas as well as the interplay between volatile loss and magma ascent plays a significant role in determining the eruption style (effusive versus explosive) as well as the magnitude of the eruption. The October 17, 1974 sub-Plinian eruption of Volcán de Fuego represents a particularly well-characterized system in terms of volatile content and magma chemistry to investigate the relation between initial water content of the magmas and the ascent rate. By modeling volatile element distribution in melt embayments through diffusion and degassing during ascent we can estimate magma ascent from the storage region in the crust to the surface. The novel aspect is the measurement of concentration gradients multiple volatile elements (in particular CO2, H2O, S) at fine-scale (5-10 μm) using the NanoSIMS. The wide range in diffusivity and solubility of these different volatiles provides multiple constraints on ascent timescales over a range of depths. H2O, CO2, and S all decrease toward the embayment outlet bubble documenting the loss of H2O and CO2 compared to an extensive melt inclusion suite from the same day of the eruption. The data is best described by a two-stage model. At high pressure (>145 MPa) decompression is slow (0.05- 0.3 MPa/s) and CO2 is bled off predominantly. At shallow levels decompression accelerates to 0.3-0.5 MPa/s at the point of H2O exsolution, which strongly affects the buoyancy of the ascending magma. The magma ascent rates presented are among the first for explosive basaltic eruptions and demonstrate the potential of the embayment method for quantifying magmatic timescales associated with eruptions of different vigor. [1] Lloyd et al. (2014) JVGR, http://dx.doi.org/10.1016/j.jvolgeores.2014.06.002

  15. Ground-water flow analysis of the Mississippi Embayment aquifer system, South-Central United States

    USGS Publications Warehouse

    Arthur, J.K.; Taylor, R.E.

    1998-01-01

    The Mississippi Embayment aquifer system is composed of six regional aquifers covering about 160,000 square miles in parts of Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee. The flow analysis presented in this report as part of the Gulf Coast Regional Aquifer-System Analysis study pertains to five aquifers in sediments of the Wilcox and Claiborne groups of Tertiary age. In descending order, the aquifers are (1) the upper Claiborne, (2) the middle Claiborne, (3) the lower Claiborne-upper Wilcox, (4) the middle Wilcox, and (5) the lower Wilcox. The flow analysis of the sixth aquifer in the aquifer system, the Mississippi River valley alluvial aquifer in sediments of Holocene and Pleistocene age, is presented in chapter D of this Professional Paper.

  16. Holocene evolution of the merrimack embayment, northern massachusetts, interperted from shallow seismic stratigraphy

    USGS Publications Warehouse

    Hein, C.J.; FitzGerald, D.M.; Barnhardt, W.A.

    2007-01-01

    Recent multi-beam, backscatter, and bottom sediment data demonstrate that a large sand sheet was formed in the inner shelf by the reworking of the Merrimack River lowstand delta and braid plain (12 kya) during the Holocene transgression. Seismic data reveal the presence of widespread channel cut-and-fill structures landward of the delta suggesting that much of the sand sheet consists of braided stream deposits. These features map into several sets of cut-and-fill structures, indicating the avulsion of the primary river channels, which creates the lobes of the paleo-delta. Truncations of these, cut-and-fill structures suggest that the braid plain deposits were probably reworked during the Holocene transgression and may have contributed sand to developing barriers that presently border the Merrimack Embayment.

  17. Water quality monitoring report for the White Oak Creek Embayment. Environmental Restoration Program

    SciTech Connect

    Ford, C.J.; Wefer, M.T.

    1993-01-01

    Water quality monitoring activities that focused on the detection of resuspended sediments in the Clinch River were conducted in conjunction with the White Oak Creek Embayment (WOCE) time-critical Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to construct a sediment-retention structure at the mouth of White Oak Creek (WOC). Samples were collected by use of a 24-h composite sampler and through real-time water grab sampling of sediment plumes generated by the construction activities. Sampling stations were established both at the WOC mouth, immediately adjacent to the construction site, and at K-1513, the Oak Ridge K-25 Site drinking water intake approximately 9.6 km downstream in the Clinch River. Results are described.

  18. Petrologic model of the northern Mississippi embayment based on satellite magnetic and ground based geophysical data

    NASA Technical Reports Server (NTRS)

    Thomas, H. H.

    1983-01-01

    Magnetization, derived from gravity-seismic data from the northern Mississippi Embayment, is evaluated relative to magnetization values obtained from satellite magnetic data. A magnetization contrast of approximately -0.54 A/m determined from the geophysical model compares favorably to a value of approximately -0.47 A/m from MAGSAT United States Apparent Magnetization contrast map. The negative magnetization contrast, required by the MAGSAT data, is unusual as rift zones with the exception of those which are currently active are associated with positive magnetization. The model presented favors an intrusion of low Curie temperature mafic rock at the base of the crust. Alternate possibilities, a shallow Curie isotherm or remanence in a direction other than that of the current main field, seem less likely as reported regional heat flow values are too low and remanence is attenuated at depth.

  19. Stratigraphic and palaeoenvironmental summary of the south-east Georgia Embayment: a correlation of exploratory wells

    USGS Publications Warehouse

    Poppe, L.J.; Popenoe, P.; Poag, C.W.; Swift, B.A.

    1995-01-01

    A Continental Offshore Stratigraphic Test (COST) well and six exploratory wells have been drilled in the south-east Georgia embayment. The oldest rocks penetrated are weakly metamorphosed Lower Ordovician quartz arenites and Silurian shales and argillites in the Transco 1005-1 well and Upper Devonian argillites in the COST GE-1 well. The Palaeozoic strata are unconformably overlain by interbedded non-marine Jurassic sandstones and shales and marginal marine Lower Cretaceous rocks. Together, these rocks are stratigraphically equivalent to the onshore Fort Pierce and Cotton Valley(?) Formations and rocks of the Lower Cretaceous Comanchean Provincial Series. The Upper Cretaceous part of the section is composed mainly of neritic calcareous shales and shaley limestones stratigraphically equivalent to the primarily marginal marine facies of the onshore Atkinson, Cape Fear and Middendorf Formations and Black Creek Group, and to limestones and shales of the Lawson Limestone and Peedee Formations. Cenozoic strata are also described. -from Authors

  20. Moving sands along a headland-embayed beach system (Algarve, Southern Portugal)

    NASA Astrophysics Data System (ADS)

    Oliveira, Sónia; Horta, João; Nascimento, Ana; Gomes, Ana; Veiga-Pires, Cristina; Moura, Delminda

    2015-04-01

    Resilience of embayed and pocket beaches located at the southernmost coast of Portugal is currently a major question to coastal management of this region. In fact, several among those beaches have been artificially fed aiming to increase the width of the beach allowing people to maintain a safe distance to the unstable rocky cliffs. The sand is dredged from the offshore (ca. 2 miles from the shoreline) representing high costs for the Portuguese government. For how long will the artificial feeding solve the problem? Which beaches are worth being nourished taking into account the morphosedimentary processes? The present work is the result of a field experiment aiming to study the efficiency of the alongshore sedimentary transport between successive embayed beaches. The experiment was performed in the very indented rocky coast of the Algarve region (Southern Portugal) and comprised two field campaigns, both in 2014, during spring tides in March and November. The Algarve coast experiences a semi-diurnal meso-tidal regime ranging from 1.3 m during neap tides to 3.5 m at spring tides and the waves approach from WSW (232°) during 72% of observations along the year, almost normal to the study area shoreline. The wave and current characteristics (significant height-Hs and Period-T for waves, velocity and direction for currents) were measured during three and six tidal cycles respectively for the first and second campaign, using two pressure transducers and one electromagnetic current meter. We used sand painted with orange fluorescent dye (100 kg in March and 200 kg in November) as tracer to track the movement of the sand along the coast. The marked sand was placed on the beach face of the westernmost beach of the study area during the first low tide of each campaign. Following, hundreds of sediment samples were collected during low tide, through the monitored period, in the nodes of a georeferenced square mesh of 10 x 20 m covering three embayed beaches. Later in the

  1. Corpus Christi, Texas

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This near vertical view of the south Texas coast shows the city of Corpus Christi (28.0N, 97.0W) and Corpus Christi Bay. Mustang Island and the Gulf of Mexico are seen in the Southeast corner of the view. The Nueces River flows into the bay from the west. The light toned squiggly lines in Corpus Christi Bay are mud trails caused by shrimp boats dragging their nets along the shallow bottom of the bay.

  2. Seismic reflection images of shallow faulting, northernmost Mississippi embayment, north of the New Madrid seismic zone

    USGS Publications Warehouse

    McBride, J.H.; Nelson, W.J.

    2001-01-01

    High-resolution seismic reflection surveys document tectonic faults that displace Pleistocene and older strata just beyond the northeast termination of the New Madrid seismic zone, at the northernmost extent of the Mississippi embayment. These faults, which are part of the Fluorspar Area fault complex in southeastern Illinois, are directly in line with the northeast-trending seismic zone. The reflection data were acquired using an elastic weight-drop source recorded to 500 msec by a 48-geophone array (24-fold) with a 10-ft (??3.0m) station interval. Recognizable reflections were recorded to about 200 msec (100-150 m). The effects of multiple reflections, numerous diffractions, low apparent velocity (i.e., steeply dipping) noise, and the relatively low-frequency content of the recorded signal provided challenges for data processing and interpreting subtle fault offsets. Data processing steps that were critical to the detection of faults included residual statics, post-stack migration, deconvolution, and noise-reduction filtering. Seismic migration was crucial for detecting and mitigating complex fault-related diffraction patterns, which produced an apparent 'folding' of reflectors on unmigrated sections. Detected individual offsets of shallow reflectors range from 5 to 10 m for the top of Paleozoic bedrock and younger strata. The migrated sections generally indicate vertical to steeply dipping normal and reverse faults, which in places outline small horsts and/or grabens. Tilting or folding of stratal reflectors associated with faulting is also locally observed. At one site, the observed faulting is superimposed over a prominent antiformal structure, which may itself be a product of the Quaternary deformation that produced the steep normal and reverse faults. Our results suggest that faulting of the Paleozoic bedrock and younger sediments of the northern Mississippi embayment is more pervasive and less localized than previously thought.

  3. Effects of aquifer travel time on nitrogen transport to a coastal embayment

    USGS Publications Warehouse

    Colman, John A.; Masterson, John P.; Pabich, Wendy J.; Walter, Donald A.

    2004-01-01

    Effects of aquifer travel time on nitrogen reaction and loading to Popponesset Bay, a eutrophic coastal embayment on western Cape Cod, Massachusetts, are evaluated through hydrologic analysis of flow and transport. Approximately 10% of the total nitrogen load to the embayment is intercepted by fresh water ponds and delivered to the coast by connecting streams. For the nitrogen load not intercepted by ponds, we compare two steady-state methods of analyzing nitrogen loss in the aquifer, one using a constant-loss factor and the other time-dependent loss rates. The constant-loss method, which assumes that all similar land uses have the same per unit area loading rate to surface water regardless of location within the watershed, predicts that 42% of the nonpond watershed nitrogen load originated within the zero to 2 yr time-of-travel zone, which is 40% of the contributing area. The time-of-travel loss method calculates loss rates based on aquifer travel times and denitrification reaction kinetics, evaluated separately for carbon-unlimited and carbon-limited cases. Time-of-travel loss calculations for percent of nonpond load that originated within the area of < 2 yr aquifer residence time are 64% when carbon is not limiting, but only 49% when carbon limitation is included, not greatly different from the constant-loss method. A feature of the kinetics used is that carbon (and the denitrified nitrogen) is lost rather quickly in the aquifer travel path, after which carbon limitation stops denitrification altogether. Carbon limitation causes the time-of-travel loss model to approximate the constant-loss model such that in most of the watershed, a nearly constant fraction of the nitrogen input is lost in both models.

  4. Occurrence of invertebrates at 38 stream sites in the Mississippi Embayment study unit, 1996-99

    USGS Publications Warehouse

    Caskey, Brian J.; Justus, B.G.; Zappia, Humbert

    2002-01-01

    A total of 88 invertebrate species and 178 genera representing 59 families, 8 orders, 6 classes, and 3 phyla was identified at 38 stream sites in the Mississippi Embayment Study Unit from 1996 through 1999 as part of the National Water-Quality Assessment Program. Sites were selected based on land use within the drainage basins and the availability of long-term streamflow data. Invertebrates were sampled as part of an overall sampling design to provide information related to the status and trends in water quality in the Mississippi Embayment Study Unit, which includes parts of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee. Invertebrate sampling and processing was conducted using nationally standardized techniques developed for the National Water-Quality Assessment Program. These techniques included both a semi-quantitative method, which targeted habitats where invertebrate diversity is expected to be highest, and a qualitative multihabitat method, which samples all available habitat types possible within a sampling reach. All invertebrate samples were shipped to the USGS National Water-Quality Laboratory (NWQL) where they were processed. Of the 365 taxa identified, 156 were identified with the semi-quantitative method that involved sampling a known quantity of what was expected to be the richest habitat, woody debris. The qualitative method, which involved sampling all available habitats, identified 345 taxa The number of organisms identified in the semi-quantitative samples ranged from 74 to 3,295, whereas the number of taxa identified ranged from 9 to 54. The number of organisms identified in the qualitative samples ranged from 42 to 29,634, whereas the number of taxa ranged from 18 to 81. From all the organisms identified, chironomid taxa were the most frequently identified, and plecopteran taxa were among the least frequently identified.

  5. Sedimentary facies and history of Upper Jurassic (Oxfordian) Smackover Formation in Conecuh embayment of south Alabama

    SciTech Connect

    Esposito, R.A.; King, D.T. Jr.

    1986-05-01

    The Upper Jurassic (Oxfordian) Smackover Formation is an important petroleum-bearing unit in the deep subsurface of the gulf rim. The authors studied the sedimentary facies and sedimentary history of the Smackover in Escambia County, Alabama. The wells studied form an east-west strike section across the Conecuh embayment in south Alabama. In the central part of the embayment, the Smackover is 350 ft (107 m) thick and consists of a vertical sequence of the following correlative sedimentary facies. In stratigraphic order, they are: (1) basal, shallow-water facies that rests conformably on the underlying Norphlet and forms a discontinuous interval a few feet thick, consisting of algal-laminated mudstones, sandy packstones and grainstones, and clast horizons; (2) basinal, deep-water facies, 175 ft (53 m) thick, consisting of resedimented debris beds (oolitic-pisolitic-graded beds, 8 in or 24 cm thick) intercalated with laminated, very argillaceous mudstone and wackestone; (3) parallel and wavy-laminated, sparsely fossiliferous packstone and wackestone, 80 ft (24 m) thick, interpreted as a carbonate slope deposit that accumulated below storm wave base; (4) bioturbated oolitic, pelletal, and fossiliferous packstone with faint relict laminations, 45 ft (14 m) thick, containing abundant Thalassinoides and Zoophycus traces and interpreted as below normal wave base deposits; and (5) oolitic and fossiliferous grainstone, 50 ft (15 m) thick, interpreted as deposits formed above wave base (shelf-platform deposits). The above sequence suggests progradation of a carbonate shelf. This progradation probably followed the rapid eustatic sea-level rise of the Oxfordian.

  6. Stratigraphic and palaeoenvironmental summary of the south-east Georgia embayment: a correlation of exploratory wells

    USGS Publications Warehouse

    Poppe, Lawrence J.; Popenoe, Peter; Poag, C. Wylie; Swift, B. Ann

    1995-01-01

    A Continental Offshore Stratigraphic Test (COST) well and six exploratory wells have been drilled in the south-east Georgia embayment. The oldest rocks penetrated are weakly metamorphosed Lower Ordovician quartz arenites and Silurian shales and argillites in the Transco 1005-1 well and Upper Devonian argillites in the COST GE-1 well. These marine strata, which are equivalent to the Tippecanoe sequence in Florida, underlie the post-rift unconformity and represent part of a disjunct fragment of Gondwana that was sutured to the North American craton during the late Palaeozoic Alleghanian orogeny. The Palaeozoic strata are unconformably overlain by interbedded non-marine Jurassic (Bajocian and younger) sandstones and shales and marginal marine Lower Cretaceous sandstones, calcareous shales and carbonates, which contain scattered beds of coal and evaporite. Together, these rocks are stratigraphically equivalent to the onshore Fort Pierce and Cotton Valley(?) Formations and rocks of the Lower Cretaceous Comanchean Provincial Series. The abundance of carbonates and evaporites in this interval, which reflects marine influences within the embayment, increases upwards, eastwards and southwards. The Upper Cretaceous part of the section is composed mainly of neritic calcareous shales and shaley limestones stratigraphically equivalent to the primarily marginal marine facies of the onshore Atkinson, Cape Fear and Middendorf Formations and Black Creek Group, and to limestones and shales of the Lawson Limestone and Peedee Formations. Cenozoic strata are primarily semiconsolidated marine carbonates. Palaeocene to middle Eocene strata are commonly cherty; middle Miocene to Pliocene strata are massive and locally phosphatic and glauconitic; Quaternary sediments are dominated by unconsolidated carbonate sands. The effects of eustatic changes and shifts in the palaeocirculation are recorded in the Upper Cretaceous and Tertiary strata.

  7. Deciphering tectonic phases of the Amundsen Sea Embayment shelf, West Antarctica, from a magnetic anomaly grid

    NASA Astrophysics Data System (ADS)

    Gohl, Karsten; Denk, Astrid; Eagles, Graeme; Wobbe, Florian

    2013-02-01

    The Amundsen Sea Embayment (ASE), with Pine Island Bay (PIB) in the eastern embayment, is a key location to understanding tectonic processes of the Pacific margin of West Antarctica. PIB has for a long time been suggested to contain the crustal boundary between the Thurston Island block and the Marie Byrd Land block. Plate tectonic reconstructions have shown that the initial rifting and breakup of New Zealand from West Antarctica occurred between Chatham Rise and the eastern Marie Byrd Land at the ASE. Recent concepts have discussed the possibility of PIB being the site of one of the eastern branches of the West Antarctic Rift System (WARS). About 30,000 km of aeromagnetic data - collected opportunistically by ship-based helicopter flights - and tracks of ship-borne magnetics were recorded over the ASE shelf during two RV Polarstern expeditions in 2006 and 2010. Grid processing, Euler deconvolution and 2D modelling were applied for the analysis of magnetic anomaly patterns, identification of structural lineaments and characterisation of magnetic source bodies. The grid clearly outlines the boundary zone between the inner shelf with outcropping basement rocks and the sedimentary basins of the middle to outer shelf. Distinct zones of anomaly patterns and lineaments can be associated with at least three tectonic phases from (1) magmatic emplacement zones of Cretaceous rifting and breakup (100-85 Ma), to (2) a southern distributed plate boundary zone of the Bellingshausen Plate (80-61 Ma) and (3) activities of the WARS indicated by NNE-SSW trending lineaments (55-30 Ma?). The analysis and interpretation are also used for constraining the directions of some of the flow paths of past grounded ice streams across the shelf.

  8. Scale and pattern of broadnose sevengill shark Notorynchus cepedianus movement in estuarine embayments.

    PubMed

    Williams, G D; Andrews, K S; Katz, S L; Moser, M L; Tolimieri, N; Farrer, D A; Levin, P S

    2012-04-01

    The detailed movements of 32 acoustically tagged broadnose sevengill shark Notorynchus cepedianus were documented in and around north-east Pacific Ocean estuarine embayments from 2005 to 2007. Arrangements of passive acoustic receivers allowed analysis of movement at several spatial scales, with sex and size examined as possible factors influencing the pattern and timing of these movements. Notorynchus cepedianus exhibited a distinctly seasonal pattern of estuary use over three consecutive years, entering Willapa Bay in the spring, residing therein for extended periods of time during the summer and dispersing into nearshore coastal habitats and over the continental shelf during the autumn. Notorynchus cepedianus within Willapa Bay showed spatio-temporal patterns of segregation by size and sex, with males and small females using peripheral southern estuary channels early in the season before joining large females, who remained concentrated in central estuary channels for the entire season. Individuals displayed a high degree of fidelity not only to Willapa Bay (63% were documented returning over three consecutive seasons), but also to specific areas within the estuary, showing consistent patterns of site use from year to year. Cross-estuary movement was common during the summer, with most fish also moving into an adjacent estuarine embayment for some extent of time. Most winter and autumn coastal detections of N. cepedianus were made over the continental shelf near Oregon and Washington, U.S.A., but there were also examples of individuals moving into nearshore coastal habitats further south into California, suggesting the feasibility of broad-scale coastal movements to known birthing and nursery grounds for the species. These findings contribute to a better understanding of N. cepedianus movement ecology, which can be used to improve the holistic management of this highly mobile apex predator in regional ecosystems.

  9. Upper Maastrichtian ammonite biostratigraphy of the Gulf Coastal Plain (Mississippi Embayment, southern USA)

    USGS Publications Warehouse

    Larina, Ekaterina; Garb, Matthew P.; Landman, Neil H.; Dastas, Natalie; Thibault, Nicolas; Edwards, Lucy E.; Phillips, George; Rovelli, Remy; Myers, Corinne; Naujokaityte, Jone

    2016-01-01

    The Cretaceous outcrop belt of the Mississippi Embayment in the Gulf Coastal Plain (GCP) spans the Cretaceous/Paleogene (K/Pg) boundary. A detailed reconstruction of this time interval is critical for understanding the nature of biotic and environmental changes preceding the end-Cretaceous Mass Extinction event and for deciphering the likely extinction mechanism (i.e., bolide impact versus volcanism). Eight sections encompassing the K/Pg succession across the Mississippi Embayment were analyzed using biostratigraphic sampling of ammonites, dinoflagellates, and nannofossils. An upper Maastrichtian ammonite zonation is proposed as follows, from oldest to youngest:Discoscaphites conradi Zone, D. minardi Zone, and D. iris Zone. Our study documents that the ammonite zonation established in the Atlantic Coastal Plain (ACP) extends to the GCP. This zonation is integrated with nannofossil and dinoflagellate biostratigraphy to provide a framework to more accurately determine the age relationships in this region. We demonstrate that ammonites and dinoflagellates are more reliable stratigraphic indicators in this area than nannofossils because age-diagnostic nannofossils are not consistently present within the upper Maastrichtian in the GCP. This biostratigraphic framework has the potential to become a useful tool for correlation of strata both within the GCP and between the GCP, Western Interior, and ACP. The presence of the uppermost Maastrichtian ammonite D. iris, calcareous nannofossil Micula prinsii, and dinoflagellates Palynodinium grallator and Disphaerogena carposphaeropsis suggests that the K/Pg succession in the GCP is nearly complete. Consequently, the GCP is an excellent setting for investigating fine scale temporal changes across the K/Pg boundary and ultimately elucidating the mechanisms causing extinction.

  10. Abandoned Texas oil fields

    SciTech Connect

    Not Available

    1980-12-01

    Data for Texas abandoned oil fields were primarily derived from two sources: (1) Texas Railroad Commission (TRRC), and (2) Dwight's ENERGYDATA. For purposes of this report, abandoned oil fields are defined as those fields that had no production during 1977. The TRRC OILMASTER computer tapes were used to identify these abandoned oil fields. The tapes also provided data on formation depth, gravity of oil production, location (both district and county), discovery date, and the cumulative production of the field since its discovery. In all, the computer tapes identified 9211 abandoned fields, most of which had less than 250,000 barrel cumulative production. This report focuses on the 676 abandoned onshore Texas oil fields that had cumulative production of over 250,000 barrels. The Dwight's ENERGYDATA computer tapes provided production histories for approximately two-thirds of the larger fields abandoned in 1966 and thereafter. Fields which ceased production prior to 1966 will show no production history nor abandonment date in this report. The Department of Energy hopes the general availability of these data will catalyze the private sector recovery of this unproduced resource.

  11. Clarksville field Red River County, Texas: Production and facies interpretation

    SciTech Connect

    Reed, C.H. )

    1991-03-01

    The Clarksville field was discovered in December in 1985 while targeting a deeper paleozoic horizon. Since production went on line in 1986, this field has produced over 1 million barrels of oil (MMBO) with the appearance of a considerably longer and more lucrative life. The producing horizon is a Jurassic-age lithic conglomerate sitting unconformably on the Paleozoic and Triassic structural front of the buried Ouachita range. Facies correlation out of the basin indicate this unit to be Louark age. Mapping and compositional analysis indicate the depositional environmental of this unit to be an arid climate alluvial fan deposited as a 'Bajada' complex. This fan system was laid down at the updip margin of the actively forming Mesozoic embayment where it meets the Ouachita structural front. The significance of this field is demonstrated by the production yield at a relatively shallow depth (5800 ft). At this time, production similar to Clarksville field has yet to be encountered anywhere along the Mesozoic rim of the East Texas basin but does represent a viable exploration trend, in addition to being a gateway for future paleozoic production in the basin.

  12. The Mississippi Embayment Regional Aquifer Study (MERAS): Documentation of a Groundwater-Flow Model Constructed to Assess Water Availability in the Mississippi Embayment

    USGS Publications Warehouse

    Clark, Brian R.; Hart, Rheannon M.

    2009-01-01

    The Mississippi Embayment Regional Aquifer Study (MERAS) was conducted with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater. This report documents the construction and calibration of a finite-difference groundwater model for use as a tool to quantify groundwater availability within the Mississippi embayment. To approximate the differential equation, the MERAS model was constructed with the U.S. Geological Survey's modular three-dimensional finite-difference code, MODFLOW-2005; the preconditioned conjugate gradient solver within MODFLOW-2005 was used for the numerical solution technique. The model area boundary is approximately 78,000 square miles and includes eight States with approximately 6,900 miles of simulated streams, 70,000 well locations, and 10 primary hydrogeologic units. The finite-difference grid consists of 414 rows, 397 columns, and 13 layers. Each model cell is 1 square mile with varying thickness by cell and by layer. The simulation period extends from January 1, 1870, to April 1, 2007, for a total of 137 years and 69 stress periods. The first stress period is simulated as steady state to represent predevelopment conditions. Areal recharge is applied throughout the MERAS model area using the MODFLOW-2005 Recharge Package. Irrigation, municipal, and industrial wells are simulated using the Multi-Node Well Package. There are 43 streams simulated by the MERAS model. Each stream or river in the model area was simulated using the Streamflow-Routing Package. The perimeter of the model area and the base of the flow system are represented as no-flow boundaries. The downgradient limit of each model layer is a no-flow boundary, which approximates the extent of water with less than 10,000 milligrams per liter of dissolved solids. The MERAS model was calibrated by making manual changes to parameter values and examining residuals for hydraulic heads and streamflow. Additional calibration was achieved through

  13. Lawyers for Texas. A study of Legal Education in Texas.

    ERIC Educational Resources Information Center

    Texas Coll. and Univ. System, Austin. Coordinating Board.

    In response to requests from Texas institutions of higher education to establish additional legal education programs, the Coordinating Board, Texas College and University System in October 1972, appointed two groups to undertake a cooperative study to assist in determining whether or not additional opportunities for legal education were needed in…

  14. Solar Hot Water for Motor Inn--Texas City, Texas

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Final report describes solar domestic-hot-water heater installation at LaQuinta Motor Inn, Texas City, Texas which furnished 63% of total hot-water load of new 98-unit inn. Report presents a description of system, drawings and photographs of collectors, operations and maintenance instructions, manufacturers' specifications for pumps, and an engineer's report on performance.

  15. Integrated Geologic, Geochemical, and Geophysical Studies of Big Bend National Park, Texas

    USGS Publications Warehouse

    Gray, John E.; Finn, Carol A.; Morgan, Lisa A.; Page, William R.; Shanks, Wayne C.

    2007-01-01

    Introduction Big Bend National Park (BBNP), Texas, covers 801,163 acres (3,242 km2) and was established in 1944 through a transfer of land from the State of Texas to the United States. The park is located along a 118-mi (190-km) stretch of the Rio Grande at the United States border with Mexico. The U.S. Geological Survey (USGS) began a 5-year project in 2003 with the objective of studying a number of broad and diverse geologic, geochemical, and geophysical topics in BBNP. This fact sheet describes results of some of the research by USGS scientists working in BBNP.

  16. RiSA: A Science Festival for the Bilingual and Bicultural Rio Grande Valley

    NASA Astrophysics Data System (ADS)

    Key, Joey Shapiro; Torres, Cristina; Stone, Robert

    2014-03-01

    The Rio Grande Science and Arts (RiSA) Festival organized by the Center for Gravitational Wave Astronomy (CGWA) at the University of Texas at Brownsville (UTB) will use a wide variety of artforms to bring physics and science topics to the bilingual and bicultural population of the Rio Grande Valley of South Texas. The science and art faculty at UTB will partner with art and education professionals to create an annual community event celebrating science though art. Music, dance, poetry, and visual arts will headline the festival activities. Festival events and products will be produced in both English and Spanish to attract and inform the bilingual local community. The RiSA Festival is supported by the Science Festival Alliance and the Sloan Foundation. Supported by the Science Festival Alliance and the Sloan Foundation.

  17. Distribution of wild taro (Colocasia esculenta) in subtropical Texas, growth of young colonies, and tolerance to simulated herbivory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-native wild taro (Colocasia esculenta) is an ornamental plant that is an emerging invasive weed in moist riparian areas in subtropical and warm temperate river systems in Texas, with potential impacts on native plant species, habitat quality and water use in the Lower Rio Grande Basin. Observati...

  18. Back on Track to College: A Texas School District Leverages State Policy to Put Dropouts on the Path to Success

    ERIC Educational Resources Information Center

    Allen, Lili; Wolfe, Rebecca E.

    2010-01-01

    In the Rio Grande Valley of south Texas, the Pharr-San Juan-Alamo Independent School District has achieved a startling success over the last two years: it has recovered and graduated over 600 dropouts and put them on a clear pathway to college. Just a few years ago, low graduation rates, struggling high schools, and poor staff and student morale…

  19. Do Trends in Physical Activity, Sedentary, and Dietary Behaviors Support Trends in Obesity Prevalence in 2 Border Regions in Texas?

    ERIC Educational Resources Information Center

    Ezendam, Nicole P. M.; Springer, Andrew E.; Brug, Johannes; Oenema, Anke; Hoelscher, Deanna H.

    2011-01-01

    Objective: The aim of the study was to compare the change in energy balance-related behaviors from 2000-2002 to 2004-2005 between 2 Texas regions with distinct patterns in obesity prevalence (decrease in the El Paso region [EP] and leveling off in the Rio Grande Valley region [RGV]) and to determine the role of the behaviors in the difference in…

  20. "Ganas": From the Individual to the Community, and the Potential for Improving College Going in the "Land That Texas Forgot"

    ERIC Educational Resources Information Center

    Cabrera, Nolan L.; Lopez, Patricia D.; Saenz, Victor B.

    2012-01-01

    This study explores college-going "ganas" in the South Rio Grande Valley of Texas within the context of Frierian liberatory praxis. During focus groups, current and former high school students discussed their experiences developing "ganas" regarding college going and discussed how parental support was integral to…

  1. Texas Education Miracle No Mirage.

    ERIC Educational Resources Information Center

    Greene, Jay P.

    2000-01-01

    Defends the significant increases seen in Texas student achievement during the 1990s, addressing attacks on the validity of these improvements. Supports the governor's emphasis on accountability testing because of its positive results, concluding that the Texas Assessment of Academic Skills holds students and schools accountable and provides…

  2. Overview: Research Funding in Texas

    ERIC Educational Resources Information Center

    Texas Higher Education Coordinating Board, 2009

    2009-01-01

    Obtaining more federal funds is the expressed research goal in "Closing the Gaps by 2015." It states: By 2015, increase the level of federal science and engineering research and development obligations to Texas institutions to 6.5 percent of obligations to higher education institutions across the nation. In 2006, Texas institutions of…

  3. Texas Coastal Cleanup Report, 1986.

    ERIC Educational Resources Information Center

    O'Hara, Kathryn; And Others

    During the 1986 Coastweek, a national event dedicated to improvement of the marine environment, a large beach cleanup was organized on the Texas coast. The goals of the cleanup were to create public awareness of the problems caused by marine debris, and to collect data on the types and quantities of debris found on the Texas coastline. The…

  4. Alternative Teacher Certification in Texas.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This publication describes alternative teacher certification programs in Texas that train interns who are generally mature, mid-career individuals. The document is organized into seven sections: (1) "Alternative Certification in Texas" discusses the history and background of the programs including legislation, the first alternative…

  5. Producing physicians for south Texas.

    PubMed

    Thomson, W A; Denk, J P; Ferry, P G; Martinez-Wedig, C; Michael, L H

    1999-01-01

    South Texas, one of the fastest growing regions in the country, remains among the most medically underserved, in part, because few students from South Texas enter medical school. To address this issue and to increase the diversity of the matriculant pool, Baylor College of Medicine (BCM) and The University of Texas-Pan American (UT-PA) established in 1994 the Premedical Honors College (PHC), a rigorous undergraduate program at UT-PA for students from South Texas high schools. Students who complete all PHC requirements and BCM prerequisites are accepted into BCM upon graduation from UT-PA. Those in good standing receive counseling, enrichment experiences, and tuition and fee waivers from UT-PA and BCM. The program is increasing the number of students from South Texas universities matriculating into medical school, and is expanding the involvement of local physicians in undergraduate education, heightening visibility for partner institutions, and becoming an effective, replicable bachelor of science/doctor of medicine model.

  6. Hydrogeology of Webb County, Texas

    USGS Publications Warehouse

    Lambert, Rebecca B.

    2004-01-01

    IntroductionWebb County, in semiarid South Texas on the U.S.-Mexico border, is a region confronted by increasing stresses on natural resources. Laredo (fig. 1), the largest city in Webb County (population 193,000 in 2000), was one of the 10 fastest-growing metropolitan areas in the country during 1990-2000 (Perry and Mackun, 2001). Commercial and industrial activities have expanded throughout the region to support the maquiladora industry (manufacturing plants in Mexico) along the border and other growth as a result of the passage of the North American Free Trade Agreement. The Rio Grande currently (2002) is the primary source of public water supply for Laredo and other cities along the border in Webb County (fig. 1). Other cities, such as Bruni and Mirando City in the southeastern part of the county, rely on ground-water supplies to meet municipal demands. Increased water demand associated with development and population growth in the region has increased the need for the City of Laredo and Webb County to evaluate alternative water sources to meet future demand. Possible options include (1) supplementing the surface-water supply with ground water, and (2) applying artificial storage and recovery (ASR) technology to recharge local aquifers. These options raise issues regarding the hydraulic capability of the aquifers to store economically substantial quantities of water, current or potential uses of the resource, and possible effects on the quality of water resulting from mixing ground water with alternative source waters. To address some of these issues, the U.S. Geological Survey (USGS), in cooperation with the City of Laredo, began a study in 1996 to assess the ground-water resources of Webb County. A hydrogeologic study was conducted to review and analyze available information on the hydrogeologic units (aquifers and confining units) in Webb County, to locate available wells in the region with water-level and water-quality information from the aquifers, and to

  7. NanoSIMS results from olivine-hosted melt embayments: Modeling ascent rate in explosive basaltic eruptions

    NASA Astrophysics Data System (ADS)

    Lloyd, A. S.; Plank, T.; Ruprecht, P.; Hauri, E. H.; Gonnermann, H. M.; Rose, W. I.

    2012-12-01

    A critical parameter governing the explosivity of volcanic eruptions is the rate at which magma ascends and degases, because this affects bubble nucleation, coalescence, and ultimately fragmentation. Although several methods have been used to determine magma ascent rates, it remains a poorly constrained parameter for most eruptions. One promising method employs diffusion modeling of H2O and CO2 concentration gradients in melt embayments/open melt inclusions [1,2]. Here we utilize the fine spatial resolution of the nanoSIMS to obtain concentration gradients for five volatile species, improving upon previous efforts that were more limited in spatial resolution (FTIR, [1]) and in number of volatile analytes (H2O only by BSE, [2]). Focusing on explosive basaltic eruptions, for which very little is known about ascent rates, we chose ash and lapilli samples from the Oct 1974 sub-plinian eruption of Volcán de Fuego. Glassy, olivine-hosted embayments with evidence of outlet bubbles were analyzed by nanoSIMS at a minimum distance between spots of 15 μm. Major element zonation in the embayments was investigated by EMP, and high resolution BSE images were captured to complement the nanoSIMS spot measurements for H2O (as in [2]). We report analyses for 5 embayments that vary in length from 100 to 350 μm. Low-solubility volatiles (CO2, H2O, S) decrease towards the embayment outlet, consistent with diffusive reequilibration with the more-degassed surrounding melt. High-solubility volatiles (Cl, F) increase towards the outlet, apparently behaving as magmaphile elements. Major elements exhibit constant concentrations along the embayment, except for a 20-50 μm wide zone near the embayment outlet, perhaps representing a boundary layer at the outlet bubble, where concentrations vary consistent with olivine and clinopyroxene microlite growth. BSE grayscale values are thus affected by both H2O diffusion and major element zonation at the embayment outlet, and cannot be used to

  8. Convective circulation during differential heating and cooling in the Minky Creek embayment of Guntersville Reservoir, data summary for 1991

    SciTech Connect

    Smith, C.S.; James, W.F.; Barko, J.W. |

    1993-06-01

    Convective circulation patterns were examined in the Minky Creek embayment of Guntersville Reservoir, Alabama, during Mid-august to mid-October 1990 and mid-May through mid-November 1991. This report describes the results obtained during 1991. Day time heating produced a warm surface layer at all stations, while the layer was often eliminated during nighttime cooling. For much of the study period, vertical temperature stratifications was minimal except during periods of heating or cooling. During differential heating, shallow regions were aften heated to the bottom while warming was confined to surface layers at deeper locations. During differential cooling water moved from shallow regions as an underflow of cool water and was replace by a return current of warmer surface waters from deeper regions. Wind influence the temperature gradients. These results support the contention that convective circulation can potentially be very important in reservoir embayments.

  9. The Texas We Create: State of Texas Children 2012--Texas KIDS COUNT Annual Data Book

    ERIC Educational Resources Information Center

    Deviney, Frances; Hattemer, Kori

    2012-01-01

    The 2012 data book explores how our kids have fared during the last decade--some outcomes are positive, some negative. But positive or negative outcomes for kids don't just happen. They are the inevitable results of effective or failed policy choices. The State of Texas Children 2012 combines data and policy to tell the story of Texas kids. It's…

  10. Human health risk assessment and remediation activities at White Oak Creek Embayment at Oak Ridge National Laboratory

    SciTech Connect

    Blaylock, B.G.

    1994-12-31

    Cesium-137 concentrations of >10{sup 6} Bq/kg dry wt (10{sup 4} pCi/g dry wt) were found in the surface sediments of White Oak Creek Embayment (WOCE) during 1990. A review of past data indicated Cesium-137, among other contaminants, was released from White Oak dam in the mid 1950s and had accumulated in the sediment of WOCE. The sediments from WOCE were being eroded and transported downstream primarily during winter low-water levels by flood events and by a combination of normal downstream flow and water turbulence. Sampling was conducted to determine the extent of radiological and nonradiological contamination. A contaminant screening analysis was conducted to determine which contaminants pose a problem from a human health standpoint. All noncarcinogens had screening indices of <1.0, indicating that concentrations of noncarcinogens were below the levels of concern for a realistic maximum exposure situation. An illegal intruder or an individual using the embayment for fishing purposes could be exposed to >10{sup 4} risk of excess lifetime cancer incidence from external exposure to Cesium-137 in sediment and from ingestion of polychlorinated biphenyls in fish. As a result of these analyses and the fact that >10{sup 6} Bq/kg dry wt (10{sup 4} pCi/g dry wt) of Cesium-137 could be transported from the Oak Ridge Reservation, a coffer-cell dam was constructed at the mouth of White Oak Creek in 1992 to: (1) reduce sediment erosion and the transport of radioactive sediments from the WOCE into the Clinch River, (2) maintain year-round inundation of the embayment sediments to reduce external radiation exposure, and (3) impede the movement of fish into and out of the embayment. The effectiveness of this remediation is being evaluated.

  11. Isolation of naturally occurring enteroviruses from a variety of shellfish species residing in Long Island and New Jersey marine embayments

    SciTech Connect

    Vaughn, J.M.; Landry, E.F.; Vicale, T.J.; Dahl, M.C.

    1980-02-01

    Shellfish and shellfish-raising waters from a variety of Long Island and New Jersey marine embayments were examined for the presence of human enteroviruses. Little difference in virological quality was noted between areas designated as being open or closed to shellfishing. Viral isolations could not be correlated with coliform counts from identical samples, indicating the need to re-evaluate the use of bacterial standards as indices of the overall sanitary quality of water and shellfish.

  12. Ectosymbiosis associated with cidaroids (Echinodermata: Echinoidea) promotes benthic colonization of the seafloor in the Larsen Embayments, Western Antarctica

    NASA Astrophysics Data System (ADS)

    Hardy, C.; David, B.; Rigaud, T.; De Ridder, C.; Saucède, T.

    2011-03-01

    Ice-shelf collapses in the Larsen A and B embayments along the Weddell side of the Antarctic Peninsula resulted in new open-water areas that are likely reorganizing benthic communities. It is a natural laboratory to assess colonization of the sea bottom under new conditions. We tested the hypothesis that the epibionts associated to cidaroid echinoids could promote or enhance the colonization of hard surfaces. In fact, being vagile, cidaroids might improve dispersal capabilities of the sessile animals that are attached to their spines, e.g., promoting the colonization of areas where the fauna has been eradicated by iceberg scouring. If this hypothesis is correct, pioneer sessile species present locally on stones might have affinities with ectosymbionts on cidaroids, and the sessile fauna present both on cidaroids and stones should be more similar in the Larsen embayments than in undisturbed areas. We therefore compared sessile species living on cidaroids with those living on stones in three areas: Larsen A and B embayments and two undisturbed and geographically different areas, Atka Bay and Elephant Island. Overall, richness, evaluated as 'morphotypes' richness, was lower in the Larsen area than in other areas, but levels of species diversity were similar among the three zones. The estimate of similarity between assemblages (using the C22 index of Chao et al., 2008) also suggests that cidaroid epibionts are either species-specific or specific to cidaroids, while the composition of sessile fauna on stones is more variable and probably dependent on local factors. In the two undisturbed areas, sessile fauna are highly different between stones and cidaroids. This contrasts with the Larsen embayments where cidaroids share more than 80% of epibionts with the surrounding stones. These results suggest that ectosymbioses linked to cidaroids strongly contribute to benthic colonization of the seafloor in the Larsen enbayments. With time, secondary successions are expected to

  13. Glacial geomorphology and past ice flows in the Larsen A embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Campo, J.; Wellner, J. S.; Lavoie, C.

    2012-12-01

    During the Last Glacial Maximum (LGM), the expanded Antarctic Peninsula Ice Sheet was grounded on the continental shelf in the Northwestern Weddell Sea at least 10 km past the modern grounding line. The grounded ice of the Antarctic Peninsula Ice Sheet sculpted a suite of characteristic geomorphic features onto the shelf - features that were uncovered upon the retreat of the ice sheet, indicating flow direction and style. The break up of the Larsen A Ice Shelf in recent decades has continued to expose more areas of the inner shelf. A US. Antarctic Program cruise aboard the NB Palmer, completed in April of this year as part of the LARISSA program, collected multibeam swath bathymetric data and 3.5 kHz chirp sub-bottom sediment profiler data in the Larsen A embayment. New multibeam data close to the shoreline, particularly in Drygalski Trough and Bombardier Bay, has been merged with existing swath data from the U.S. and British programs to permit mapping and interpretation of ice flow from the tributaries and across the shelf. Initial observations of chirp data suggest little marine or glaciomarine sediment has accumulated in these tributary fjords, hinting that glacial retreat there occurred relatively recently. All sediment volumes for which profiles were collected occur above the glacial unconformity carved by the post-glacial retreat. Interpretation of chirp data is ongoing for volume calculations and mapping of discrete units. Ongoing work is currently being completed to measure volumes of sediment accumulation, which will then be correlated to sediment cores studied by project collaborators. The multibeam data is being analyzed in ArcGIS to determine the changes in length/width scales of the geomorphic features. As expected, the subglacial features on the outer shelf are elongated compared to the linear features on the inner shelf. Based on Evans, et al. [2005] combined with data collected this year, we have mapped ice flow form the tributaries and out through

  14. Texas Affordable Baccalaureate Program: A Collaboration between the Texas Higher Education Coordinating Board, South Texas College, and Texas A&M University-Commerce. CBE Case Study

    ERIC Educational Resources Information Center

    Klein-Collins, Rebecca; Glancey, Kathleen

    2015-01-01

    This case study is part of a series on newer competency-based degree programs that have been emerging in recent years. In January 2014, the Texas Higher Education Coordinating Board (THECB), South Texas College (STC), and Texas A&M University-Commerce (A&M Commerce) launched the Texas Affordable Baccalaureate Program, the state's first…

  15. Population Change and the Future of Texas.

    ERIC Educational Resources Information Center

    Marshall, F. Ray; Bouvier, Leon F.

    The future is filled with demographic change for the State of Texas. As the population becomes more ethnically diverse, the Texas demographic, economic, and sociocultural profiles also will change. This volume presents a wide range of demographic information on the State of Texas. The 10 chapters look at: (1) the population of Texas: past,…

  16. TEXAS MIGRANT LABOR, THE 1964 MIGRATION.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    THE MAJORITY OF TEXAS MIGRANTS LIVE IN SOUTH TEXAS AND APPROXIMATELY 95 PERCENT OF THEM ARE OF MEXICAN EXTRACTION. MOST OF THE OTHER FIVE PERCENT ARE EAST TEXAS NEGROES. THE MECHANIZATION OF COTTON HARVESTING AND THE EXPIRATION OF THE "BRACERO PROGRAM" IN 1964 HAVE CAUSED MORE TEXAS MIGRANTS TO SEEK EMPLOYMENT OUTSIDE OF THE STATE. DURING 1964,…

  17. Water supply and needs for West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation focused on the water supplies and needs of West Texas, Texas High Plains. Groundwater is the most commonly used water resources on the Texas High Plains, with withdrawals from the Ogallala Aquifer dominating. The saturation thickness of the Ogallala Aquifer in Texas is such that t...

  18. Charter Schools in Texas: An Overview

    ERIC Educational Resources Information Center

    Penning, Francisco; Slate, John R.

    2011-01-01

    In this article we analyzed the literature regarding charter schools in the State of Texas. We specifically examined the evolution of the charter school movement in Texas. Moreover, data regarding the effectiveness/ineffectiveness of charter schools in Texas were discussed. Our overview of Texas charter schools, given their widespread presence in…

  19. 78 FR 11579 - Texas Regulatory Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ... and updating of data into the Applicant Violator System. Additionally, Texas is adding new language... Office of Surface Mining Reclamation and Enforcement 30 CFR Part 943 Texas Regulatory Program AGENCY... the Texas regulatory program (Texas program) under the Surface Mining Control and Reclamation Act...

  20. Using modelling to predict impacts of sea level rise and increased turbidity on seagrass distributions in estuarine embayments

    NASA Astrophysics Data System (ADS)

    Davis, Tom R.; Harasti, David; Smith, Stephen D. A.; Kelaher, Brendan P.

    2016-11-01

    Climate change induced sea level rise will affect shallow estuarine habitats, which are already under threat from multiple anthropogenic stressors. Here, we present the results of modelling to predict potential impacts of climate change associated processes on seagrass distributions. We use a novel application of relative environmental suitability (RES) modelling to examine relationships between variables of physiological importance to seagrasses (light availability, wave exposure, and current flow) and seagrass distributions within 5 estuarine embayments. Models were constructed separately for Posidonia australis and Zostera muelleri subsp. capricorni using seagrass data from Port Stephens estuary, New South Wales, Australia. Subsequent testing of models used independent datasets from four other estuarine embayments (Wallis Lake, Lake Illawarra, Merimbula Lake, and Pambula Lake) distributed along 570 km of the east Australian coast. Relative environmental suitability models provided adequate predictions for seagrass distributions within Port Stephens and the other estuarine embayments, indicating that they may have broad regional application. Under the predictions of RES models, both sea level rise and increased turbidity are predicted to cause substantial seagrass losses in deeper estuarine areas, resulting in a net shoreward movement of seagrass beds. Seagrass species distribution models developed in this study provide a valuable tool to predict future shifts in estuarine seagrass distributions, allowing identification of areas for protection, monitoring and rehabilitation.

  1. Upper Cretaceous molluscan record along a transect from Virden, New Mexico, to Del Rio, Texas

    USGS Publications Warehouse

    Cobban, W.A.; Hook, S.C.; McKinney, K.C.

    2008-01-01

    Updated age assignments and new collections of molluscan fossils from lower Cenomanian through upper Campanian strata in Texas permit a much refined biostratigraphic correlation with the rocks of New Mexico and the Western Interior. Generic names of many Late Cretaceous ammonites and inoceramid bivalves from Texas are updated to permit this correlation. Strata correlated in the west-to-east transect include the lower Cenomanian Beartooth Quartzite and Sarten Sandstone of southwest New Mexico, and the Eagle Mountains Formation, Del Rio Clay, Buda Limestone, and. basal beds of the Chispa Summit, Ojinaga, and Boquillas Formations of the Texas-Mexico border area. Middle Cenomanian strata are lacking in southwestern New Mexico but are present in the lower parts of the Chispa Summit and Boquillas Formations in southwest Texas. Upper Cenomanian and lower Turonian rocks are present at many localities in New Mexico and Texas in the Mancos Shale and Chispa Summit, Ojinaga, and Boquillas Formations. Middle Turonian and younger rocks seem to be entirely nonmarine in southwestern New Mexico, but they are marine in the Rio Grande area in the Chispa. Summit, Ojinaga, and Boquillas Formations. The upper part of the Chispa Summit and Boquillas contain late Turonian fossils. Rocks of Coniacian and Santonian age are present high in the Chispa Summit, Ojinaga, and Boquillas Formations, and in the lower part of the Austin. The San Carlos, Aguja, Pen, and Austin Formations contain fossils of Campanian age. Fossils representing at least 38 Upper Cretaceous ammonite zones are present along the transect. Collections made in recent years in southwestern New Mexico and at Sierra de Cristo Rey just west of downtown El Paso, Texas, have been well treated and do not need revision. Taxonomic names and zonations published in the pre-1970 literature on the Rio Grande area of Texas have been updated. New fossil collections from the Big Bend National Park, Texas, allow for a much refined correlation

  2. Texas floods of 1940

    USGS Publications Warehouse

    Breeding, Seth D.

    1948-01-01

    Floods occurred in Texas during, June, July, and November 1940 that exceeded known stages on many small streams and at a few places on the larger streams. Stages at several stream-gaging stations exceeded the maximum known at those places since the collection of daily records began. A storm, haying its axis generally on a north-south line from Cameron to Victoria and extending across the Brazos, Colorado, Lavaca, and Guadalupe River Basins, caused heavy rainfall over a large part of south-central Texas. The maximum recorded rain of 22.7 inches for the 2-day period June 29-30 occurred at Engle. Of this amount, 17.5 inches fell in the 12-hour period between 8 p.m. June 29, and 8 a.m. June 30. Light rains fell at a number of places on June 28, and additional light rains fell at many places within the area from July 1 to 4. During the period June 28 to July 4 more than 20 inches of rain fell over an area of 300 square miles, more than 15 inches over 1,920 square miles, and more than 10 inches over 5,100 square miles. The average annual rainfall for the area experiencing the heaviest rainfall during this storm is about 35 inches. Farming is largely confined to the fertile flood plains in much of the area subjected to the record-breaking floods in June and July. Therefore these floods, coming at the height of the growing season, caused severe losses to crops. Much damage was done also to highways and railways. The city of Hallettsville suffered the greatest damage of any urban area. The Lavaca River at that place reached a stage 8 feet higher than ever known before, drowned several people, destroyed many homes, and submerged almost the entire business district. The maximum discharge there was 93,100 second-feet from a drainage area of 101 square miles. Dry Creek near Smithville produced a maximum discharge of 1,879 second-feet from an area of 1.48 square miles and a runoff of 11.3 inches in a 2-day period from a rainfall of 19.5 inches. The area in the Colorado River

  3. Aflatoxin contamination of commercial cottonseed in South Texas.

    PubMed

    Jaime-Garcia, Ramon; Cotty, Peter J

    2003-09-01

    ABSTRACT Aflatoxins are toxic fungal metabolites produced by several members of Aspergillus section Flavi. U.S. federal regulations limit the use of aflatoxin-contaminated cottonseed. Cottonseed with aflatoxin content of 20 ng/g or higher may not enter the profitable dairy market. Between 4,472 and 9,949 truckloads of cottonseed from 31 to 35 gins in South Texas were analyzed for aflatoxin content each year from 1997 to 2001 upon receipt at the Valley Co-op Oil Mill in Harlingen, TX. The highest levels of contamination occurred in 1999, with an average aflatoxin content of 112 ng/g and 66% of the cottonseed truckloads exceeding 20 ng/g. Years 1997 and 2000 had the lowest aflatoxin levels, averaging 24 ng/g, with the lowest incidence (16%) of the truckloads exceeding 20 ng/g in 1997. In general, aflatoxin contamination increased as the ginning season progressed. Rainfall after boll opening correlated highly with aflatoxin content, with rainfall in July explaining over 50% of the observed variability in aflatoxin content. South Texas was divided into four regions: Rio Grande Valley, Coastal Bend, Upper Coast, and Winter Garden. Geostatistical analyses revealed recurrent patterns of high and low contamination. The greatest contamination occurred from the central Coastal Bend region through the southern Upper Coast region. The Rio Grande Valley region experienced the least contamination during the study period.

  4. Geology and ground-water resources of Duval County, Texas

    USGS Publications Warehouse

    Sayre, Albert Nelson

    1937-01-01

    Duval County is situated in southern Texas, 100 to 150 miles south of San Antonio and about midway between Corpus Christi, on the Gulf of Mexico, and Laredo, on the Rio Grande. The county lies on the Coastal Plain, which for the most part is low and relatively featureless. Between the Nueces River and the Rio Grande in this part of Texas the plain is interrupted by an erosion remnant, the Reynosa Plateau, which reaches a maximum altitude of nearly 1,000 feet above sea level and stands well above the areas to the east and west. The Reynosa Plateau includes most of Duval County and parts of Webb, Zapata, Starr, Jim Hogg, Jim Wells, McMullen, and Live Oak Counties. In Duval County the plateau is bounded on the west by the westward-facing Bordas escarpment, 75 to 150 feet high, which crosses the county with a southwesterly trend from about the middle of the north boundary to about the middle of the west boundary. On the east the plateau is bounded by a low seaward-facing escarpment, which passes through San Diego, trending a little west of south.

  5. White Oak Creek Embayment site characterization and contaminant screening analysis. Environmental Restoration Program

    SciTech Connect

    Blaylock, B.G.; Ford, C.J.; Frank, M.L.; Hoffman, F.O.; Hook, L.A.

    1993-01-01

    Analyses of sediment samples collected near the mouth of White Oak Creek during the summer of 1990 revealed {sup 137}Cs concentrations [> 10{sup 6} Bq/kg dry wt (> 10{sup 4} pCi/g dry wt)] near the sediment surface. Available evidence indicates that these relatively high concentrations of {sup 137}Cs now at the sediment surface were released from White Oak Dam in the mid-1950s and had accumulated at depositionalsites in the embayment. These accumulated sediments are being eroded and transported downstream primarily during winter low-water levels by flood events and by a combination of normal downstream flow and the water turbulence created by the release of water from Melton Hill Dam during hydropower generation cycles. This report provides a more thorough characterization of the extent of contamination in WOCE than was previously available. Environmental samples collected from WOCE were analyzed for organic, inorganic, and radiological contaminants in fish, water, and sediment. These results were used to conduct a human health effects screening analysis. Walkover radiation surveys conducted inside the fenced area surrounding the WOCE at summer-pool (741 ft MSL) and at winter-pool (733 ft MSL) level, indicated a maximum exposure rate of 3 mR h{sup 1} 1 m above the soil surface.

  6. Comparison of deterministic and stochastic earthquake simulators for fault interactions in the Lower Rhine Embayment, Germany

    NASA Astrophysics Data System (ADS)

    Hainzl, Sebastian; Zöller, Gert; Brietzke, Gilbert B.; Hinzen, Klaus-G.

    2013-10-01

    Time-dependent probabilistic seismic hazard assessment requires a stochastic description of earthquake occurrences. While short-term seismicity models are well-constrained by observations, the recurrences of characteristic on-fault earthquakes are only derived from theoretical considerations, uncertain palaeo-events or proxy data. Despite the involved uncertainties and complexity, simple statistical models for a quasi-period recurrence of on-fault events are implemented in seismic hazard assessments. To test the applicability of statistical models, such as the Brownian relaxation oscillator or the stress release model, we perform a systematic comparison with deterministic simulations based on rate- and state-dependent friction, high-resolution representations of fault systems and quasi-dynamic rupture propagation. For the specific fault network of the Lower Rhine Embayment, Germany, we run both stochastic and deterministic model simulations based on the same fault geometries and stress interactions. Our results indicate that the stochastic simulators are able to reproduce the first-order characteristics of the major earthquakes on isolated faults as well as for coupled faults with moderate stress interactions. However, we find that all tested statistical models fail to reproduce the characteristics of strongly coupled faults, because multisegment rupturing resulting from a spatiotemporally correlated stress field is underestimated in the stochastic simulators. Our results suggest that stochastic models have to be extended by multirupture probability distributions to provide more reliable results.

  7. Basin-related effects on ground motion for earthquake scenarios in the Lower Rhine Embayment

    NASA Astrophysics Data System (ADS)

    Ewald, Michael; Igel, Heiner; Hinzen, Klaus-Günter; Scherbaum, Frank

    2006-07-01

    The deterministic calculation of earthquake scenarios using complete waveform modelling plays an increasingly important role in estimating shaking hazard in seismically active regions. Here we apply 3-D numerical modelling of seismic wave propagation to M 6+ earthquake scenarios in the area of the Lower Rhine Embayment, one of the seismically most active regions in central Europe. Using a 3-D basin model derived from geology, borehole information and seismic experiments, we aim at demonstrating the strong dependence of ground shaking on hypocentre location and basin structure. The simulations are carried out up to frequencies of ca. 1 Hz. As expected, the basin structure leads to strong lateral variations in peak ground motion, amplification and shaking duration. Depending on source-basin-receiver geometry, the effects correlate with basin depth and the slope of the basin flanks; yet, the basin also affects peak ground motion and estimated shaking hazard thereof outside the basin. Comparison with measured seismograms for one of the earthquakes shows that some of the main characteristics of the wave motion are reproduced. Cumulating the derived seismic intensities from the three modelled earthquake scenarios leads to a predominantly basin correlated intensity distribution for our study area.

  8. Small-scale spatial structuring of interstitial invertebrates on three embayed beaches, Sydney, Australia

    NASA Astrophysics Data System (ADS)

    Cooke, Belinda C.; Goodwin, Ian D.; Bishop, Melanie J.

    2014-10-01

    An understanding of ecological processes hinges upon an understanding of the spatial structuring of their key biotic components. Interstitial invertebrates are a ubiquitous and ecologically important component of sandy beach ecosystems. As many sandy beach taxa have limited dispersal, it may be expected that their populations exhibit a high degree of spatial structuring, yet the spatial scales across which they display baseline variability remain largely unknown. To assess (1) whether interstitial invertebrates display patchiness on embayed sandy beaches, (2) whether the size of patches they form is consistent across three geographically proximal beaches, (3) the key environmental correlates of this variation and (4) its taxonomic dependence, samples were collected at regular (0.5 m) intervals along 15 m long geomorphically similar stretches of three proximal intermediate beaches and analyses of spatial autocorrelation were conducted. On each of the three beaches, interstitial invertebrate communities formed patches of 2-4.5 m in diameter. Spatial structuring of invertebrate communities was driven by harpacticoid copepods and gastrotrichs, and corresponded to spatial structuring of sediments. Sediments, however, explained only 33% of spatial variation in faunal communities, indicating the importance of other abiotic and/or biotic factors. Our study highlights that even on seemingly homogeneous sandy beaches, faunal communities may display considerable small-scale spatial structuring. Examination of spatial structure may lead to a greater understanding of the ecological processes in this system.

  9. Did massive glacial dewatering modify sedimentary structures on the Amundsen Sea Embayment shelf, West Antarctica?

    NASA Astrophysics Data System (ADS)

    Weigelt, Estella; Uenzelmann-Neben, Gabriele; Gohl, Karsten; Larter, Robert D.

    2012-07-01

    Multichannel seismic reflection lines collected in the western Amundsen Sea Embayment (ASE) provide an insight into the sedimentary cover on the shelf, which documents glacial processes. Numerous columnar, reflection-poor structures penetrating the sedimentary sequences on the middle shelf form the focus of this study. The features range between 50 and 500 m in width, and from a few metres up to 500 m in height. The columns originate and end at different depths, but do not seem to penetrate to the seafloor. They show well-defined vertical boundaries, and reflection signals can be identified below them. Hence, we exclude gas-bearing chimneys. Based on the general seismic reflection characteristics we suggest that the columns originate from dewatering processes which occur close to glaciated areas where fluids are pressed out of rapidly loaded sediments. Likely several mud-diapirs rise from water-rich mud layers within a mixed sedimentary succession and penetrate overlying denser and coarse-grained sediment strata. The presence of fluid-escape veins indicates a glacial origin and overprinting of the older sedimentary sequences on the ASE. The locations of the structures indicate that grounded ice sheets reached at least onto the middle shelf during former glacial periods.

  10. Influence of microscale turbulence on the phytoplankton of a temperate coastal embayment, Western Australia

    NASA Astrophysics Data System (ADS)

    Machado, Daniel A.; Marti, Clelia L.; Imberger, Jörg

    2014-05-01

    We investigated the influence of microscale turbulence on the large phytoplankton of a coastal embayment in south-western Australia. Microstructure, physical and fluorometric depth-profiling field measurements and water sampling for nutrient, chlorophyll-a analyses and counting of the large size fraction of phytoplankton (microphytoplankton) were conducted in late-winter and late-spring of 2012. In both seasons we observed dominance of diatoms, low numbers of dinoflagellates, low nutrient concentrations, nitrogen limitation, clear waters and high turbulence intensities. In late-winter, total nitrogen, chlorophyll-a and diatom cell concentrations were higher than in late-spring, but dinoflagellates abundance did not change substantially. This indicated that the chain-forming diatom life-forms that dominated (Leptocylindrus, Chaetoceros and Skeletonema) were able to utilize the increased pulses of nitrogen in late-winter. The prevailing turbulence intensities observed, associated with the wind speed, were such that the Batchelor scale was smaller than the length of the diatom chains (100-300 μm), implying that these diatoms could experience microscale nutrient gradients. By contrast, the Kolmogorov velocity scales overwhelmed the motility abilities of the dinoflagellates observed, which in turn gain only little benefit from self propulsion at high turbulence. It is suggested that, nutrient storage allows diatoms surviving calm periods of low nutrient availability and formation of siliceous cell chains provide diatoms an advantage in accessing nutrients in turbulent coastal ecosystems.

  11. Present and future prolonged drought impacts on a large temperate embayment: Port Phillip Bay, Australia

    NASA Astrophysics Data System (ADS)

    Lee, Randall S.; Black, Kerry P.; Bosserel, Cyprien; Greer, Dougal

    2012-06-01

    Observations of a large temperate embayment in Victoria, Australia, reveal a sustained climatic shift that occurred in response to a prolonged drought in the region during 1997-2009. Historically, the bay is fresher than the ocean with fresh outflow to the sea. However, the drought has caused substantially elevated salinity and temperatures above adjacent oceanic waters. The bay's capacity to dilute and flush waste discharges to the ocean was also changed. Observed conditions have been numerically modelled with hydrodynamic and coupled lagrangian particle dispersion models to test differences in dispersion and exchange during historically fresher conditions and hypersaline bay scenarios. Further scenarios were tested for projected climate conditions which were similar to the recent drought responses in the bay. The models identified the effects on the circulation of the climatic shift including regions of increased vulnerability to extreme salinity in the bay, with some existing discharges concentrating in these regions of heightened vulnerability. Absolute salinity in the bay could reach critical levels of over 38 g kg-1, in places, which may compromise bay ecology.

  12. Hydrography of and biogeochemical inputs to Liberty Bay, a small urban embayment in Puget Sound, Washington

    USGS Publications Warehouse

    Takesue, Renee K.

    2011-01-01

    This multi-chapter report describes scientific and logistic understanding gained from a 2 year proof-of-concept study in Liberty Bay, a small urban embayment in central Puget Sound, Washington. The introductory chapter describes the regional and local setting, the high-level study goals, the site-specific urban stressors, and the interdisciplinary study approach. Subsequent data chapters describe detailed studies of various components of the Liberty Bay ecosystem: the aquatic environment (Chapter 2), surface and groundwater quantity and quality (Chapter 3), sediment quality (Chapter 4), eelgrass habitat (Chapter 5), carbon and nitrogen sources (Chapter 6), and a statistical model relating herring spawn probability to shoreline attributes (Chapter 7). The final chapter synthesizes knowledge about individual components into a system-wide understanding of how urbanization may affect the Liberty Bay ecosystem. The Liberty Bay study was conducted as part of the U.S. Geological Survey's Coastal Habitats in Puget Sound project, an interdisciplinary collaboration to understand physical and biological processes that affect nearshore ecosystems.

  13. Uneven onset and pace of ice-dynamical imbalance in the Amundsen Sea Embayment, West Antarctica

    NASA Astrophysics Data System (ADS)

    Konrad, Hannes; Gilbert, Lin; Cornford, Stephen L.; Payne, Antony; Hogg, Anna; Muir, Alan; Shepherd, Andrew

    2017-01-01

    We combine measurements acquired by five satellite altimeter missions to obtain an uninterrupted record of ice sheet elevation change over the Amundsen Sea Embayment, West Antarctica, since 1992. Using these data, we examine the onset of surface lowering arising through ice-dynamical imbalance, and the pace at which it has propagated inland, by tracking elevation changes along glacier flow lines. Surface lowering has spread slowest (<6 km/yr) along the Pope, Smith, and Kohler (PSK) Glaciers, due to their small extent. Pine Island Glacier (PIG) is characterized by a continuous inland spreading of surface lowering, notably fast at rates of 13 to 15 km/yr along tributaries draining the southeastern lobe, possibly due to basal conditions or tributary geometry. Surface lowering on Thwaites Glacier (THG) has been episodic and has spread inland fastest (10 to 12 km/yr) along its central flow lines. The current episodes of surface lowering started approximately 10 years before the first measurements on PSK, around 1990 on PIG, and around 2000 on THG. Ice-dynamical imbalance across the sector has therefore been uneven during the satellite record.

  14. Genetic structure of eelgrass Zostera marina meadows in an embayment with restricted water flow

    USGS Publications Warehouse

    Munoz-Salazar, R.; Talbot, S.L.; Sage, G.K.; Ward, D.H.; Cabello-Pasini, Alejandro

    2006-01-01

    Genetic structure of the seagrass Zostera marina in a coastal lagoon with restricted water flow, and with heterogeneous water residence times and oceanographic characteristics, was assessed using 8 polymorphic microsatellite loci. Analyses of genetic differentiation (??) and Bayesian clustering suggested that the Z. marina population in San Quintin Bay (SQB) is genetically substructured, with at least 4 genetically different groups: (1) West Head, (2) Mouth, (3) East Arm, and (4) East Head. The greatest ?? value was observed between the most distant sites (?? = 0.095). The lowest values were found among sites closest to the mouth of the coastal lagoon (?? = 0.000 to 0.009). The maximum likelihood approach showed that the sites at the mouth have a mixed pattern of gene flow without a unidirectional pattern. In contrast, there was a clear pattern of asymmetrical gene flow from the mouth towards the West Head. These results suggested that the restriction of water flow at the heads, current pattern, and the distance between sites can reduce genetic flow and promote genetic differences within Z. marina meadows in small water embayments such as SQB. Though the population is genetically substructured and a 14 % decline in cover has been detected, this study did not show evidence of a recent genetic bottleneck. In contrast, mouth sites have experienced a recent expansion in their population size, and also perhaps a recent influx of rare alleles from genetically distinct immigrants. ?? Inter-Research 2006.

  15. Science to support the understanding of south Texas surface-water and groundwater resources in a changing landscape

    USGS Publications Warehouse

    Ockerman, Darwin J.; Garcia, Travis J.; Opsahl, Stephen P.

    2012-01-01

    The U.S. Geological Survey (USGS) works in cooperation with other local, State, and Federal agencies to provide timely access to water data, publications, and information to foster a better understanding of the water resources of south Texas. The USGS and our cooperators are involved in a wide variety of programs for collecting hydrologic data and scientific information in the changing landscape of south Texas to help our cooperators effectively address water-resource issues in this part of the State. This fact sheet provides an overview of our collaborative scientific endeavors in the basins of the Nueces, San Antonio, and Guadalupe Rivers and lower Rio Grande. An overview of USGS capabilities pertaining to water resource issues in Texas, including recently completed and ongoing studies in south Texas, is available at http://tx.usgs.gov/Capabilities/index.html.

  16. Nuclear Proliferation and Grand Challenges

    ScienceCinema

    McCarthy, Kathy

    2016-07-12

    Nuclear engineer Dr. Kathy McCarthy leads systems analysis. She talks about proliferation and the grand challenges of nuclear R&D. For more information about INL energy research, visit http://www.facebook.com/idahonationallaboratory.

  17. Nuclear Proliferation and Grand Challenges

    SciTech Connect

    McCarthy, Kathy

    2009-01-01

    Nuclear engineer Dr. Kathy McCarthy leads systems analysis. She talks about proliferation and the grand challenges of nuclear R&D. For more information about INL energy research, visit http://www.facebook.com/idahonationallaboratory.

  18. Water Finance Forum-Texas

    EPA Pesticide Factsheets

    Regional Finance Forum: Financing Resilient and Sustainable Water Infrastructure, held in Addison, Texas, September 10-11, 2015.Co-sponsored by EPA's Water Infrastructure and Resiliency Finance Center and the Environmental Finance Center Network.

  19. Dalhart Texas 1972-2011

    NASA Video Gallery

    A water-rich polka dot pattern takes over the traditional rectangular patchwork of fields in this 40 year sequence of Landsat images of the dry Texas panhandle near the town of Dalhart. In this ser...

  20. Synoptic Sampling of Dissolved Nitrogen Species and Organic Carbon in the Rio Grande Basin

    NASA Astrophysics Data System (ADS)

    Villinski, J. E.; Hogan, J. F.; Brooks, P. D.; Haas, P. A.; Mills, S. K.

    2002-12-01

    Synoptic sampling has been performed along the Rio Grande from the headwaters in Colorado to Fort Quitman, Texas, south of El Paso. Samples from August 2001 and January 2002 were analyzed for nitrate (NO3-), ammonium (NH_{4}$+), total dissolved nitrogen (TDN), and dissolved organic carbon (DOC). DOC concentrations increase slowly between Colorado and southern New Mexico and then approximately double in Texas. Large sources of N during both sampling periods were the urban areas around Albuquerque and El Paso, Texas and Ciudad Juarez, Mexico, and agricultural regions in the Rincon and Mesilla valleys of southern New Mexico. Nitrate-N concentrations remained high south of Albuquerque to Elephant Butte reservoir in the summer, presumably due to lack of primary production. Inorganic N concentrations generally are higher in the winter than in the summer. During the summer, ammonium concentrations were greater than 100 mg N/l only at the outlet of Elephant Butte Reservoir, and in Texas. However, winter concentrations were on average an order of magnitude greater, again with the largest ammonium values (5000 \\mug N/l) in Texas. These patterns are consistent with a reduction in biological nutrient demand during the non-growing season.

  1. Coastal Inlets of Texas, USA

    DTIC Science & Technology

    2007-01-01

    Caney Creek Freeport Ship Channel San Luis Pass Galveston Pass Rollover Fish Pass Sabine Pass Texas Victoria Houston Port Arthur Corpus Christi...1960) provide design guidance for constructing fish passes along the Texas coast, it appears that an update based on more recent experiences and...Hall Pier at Corpus Christi; and bay gauges (Rawlings at Mouth of Colorado River; Lavaca, and Port Isabel in the lower Laguna Madre ) for year 1999

  2. Embayment scale assessment of submarine groundwater discharge nutrient loading and associated land use

    NASA Astrophysics Data System (ADS)

    Young, Caitlin; Tamborski, Joseph; Bokuniewicz, Henry

    2015-06-01

    A shoreline survey of porewater nutrient concentrations and 222Rn surface water activities was performed in Port Jefferson Harbor, NY, an embayment of Long Island Sound. Submarine groundwater discharge (SGD) was calculated for individual shoreline segments; shallow porewater nutrient concentrations were applied to calculated groundwater flux values in order to spatially depict the nutrient flux to overlying harbor water. Nitrate was the dominant form of inorganic nitrogen as porewater concentrations of ammonium were negligible. Land use analysis showed that nitrate to phosphate ratios (N:P) in SGD were positively correlated with medium to high development of inland aquifer watersheds. A multivariate regression model was developed which describes 79% of the variability in shoreline nitrate discharge. Three modes of nutrient transport were observed; 1) High SGD rates coupled with nutrient rich groundwater derived from high density development, 2) moderate SGD rates coupled with low nutrient groundwater from low density development/forested watersheds and 3) negligible SGD rates associated with recirculated seawater adjacent to low density development areas. Transport mode 1 dominated total SGD nitrate inputs primarily due to steep hydraulic gradient, a characteristic of tunnel valleys in glacial deposits, which highlights the critical role hydrogeology plays in groundwater nitrogen loading to surface water. Total nitrate inputs to the harbor from shoreline SGD alone are 980 mol d-1, similar to average daily sewage treatment plant nitrogen inputs of 870 mol d-1. The techniques used in this study represent an effective methodology for calculating SGD derived nutrient loads where a surface water nutrient source is present.

  3. Moment release in the Lower Rhine Embayment, Germany: seismological perspective of the deformation process

    NASA Astrophysics Data System (ADS)

    Schmedes, J.; Hainzl, S.; Reamer, S.-K.; Scherbaum, F.; Hinzen, K.-G.

    2005-03-01

    An important task of seismic hazard assessment consists of estimating the rate of seismic moment release which is correlated to the rate of tectonic deformation and the seismic coupling. However, the estimations of deformation depend on the type of information utilized (e.g. geodetic, geological, seismic) and include large uncertainties. We therefore estimate the deformation rate in the Lower Rhine Embayment (LRE), Germany, using an integrated approach where the uncertainties have been systematically incorporated. On the basis of a new homogeneous earthquake catalogue we initially determine the frequency-magnitude distribution by statistical methods. In particular, we focus on an adequate estimation of the upper bound of the Gutenberg-Richter relation and demonstrate the importance of additional palaeoseismological information. The integration of seismological and geological information yields a probability distribution of the upper bound magnitude. Using this distribution together with the distribution of Gutenberg-Richter a and b values, we perform Monte Carlo simulations to derive the seismic moment release as a function of the observation time. The seismic moment release estimated from synthetic earthquake catalogues with short catalogue length is found to systematically underestimate the long-term moment rate which can be analytically determined. The moment release recorded in the LRE over the last 250 yr is found to be in good agreement with the probability distribution resulting from the Monte Carlo simulations. Furthermore, the long-term distribution is within its uncertainties consistent with the moment rate derived by geological measurements, indicating an almost complete seismic coupling in this region. By means of Kostrov's formula, we additionally calculate the full deformation rate tensor using the distribution of known focal mechanisms in LRE. Finally, we use the same approach to calculate the seismic moment and the deformation rate for two subsets

  4. Post-earthquake coastal evolution and recovery of an embayed beach in central-southern Chile

    NASA Astrophysics Data System (ADS)

    Martínez, Carolina; Rojas, Daniel; Quezada, Matías; Quezada, Jorge; Oliva, Ricardo

    2015-12-01

    Earthquakes and tsunamis are significant factors for change along active margin shores, and influence coastal evolution. The Chilean coast was affected in 2010 by a subduction earthquake with a magnitude of Mw 8.8 and also by a trans-Pacific tsunami, which generated violent geomorphologic changes and damaged homes. Following these events, the magnitude of the changes which affect Chile's central-southern coast (37°S) and the role of subduction earthquakes in coastal evolution on a historical scale were investigated. At Lebu bay (an embayed beach) data were generated for variations in time and space along the shoreline, topographical and bathymetric changes in the bay, and for morphodynamic littoral processes. Logarithmic and parabolic models were applied to the shoreline along with map overlays in order to determine changes. The shoreline processes were analyzed based on statistics for waves, tides and sediment transport for pre- and post-tsunami conditions. An average accretion rate of 2.80 m/year (1984-2010) was established for the shoreline, with a strong trend towards accretion in the last 30 years. A parabolic function best represented the general form of the shoreline, although the presence of a river in the concave zone affected the fit in this sector. Two factors controlled historical changes on the beach: one of anthropic origin in addition to the earthquake and tsunami on February 27th, 2010. The post-earthquake recovery was fast, and currently the beach is in a stable condition despite the inter-seismic subsidence process previous to the event. This coastal system showed a high resilience in the face of coastal geomorphological changes induced by high-impact natural disturbances. However, the opposite occurred in relation to changes induced by anthropogenic disturbances.

  5. Occurrence of pesticides in five rivers of the Mississippi Embayment Study Unit, 1996-98

    USGS Publications Warehouse

    Coupe, Richard H.

    2000-01-01

    The occurrence and temporal distribution of more than 80 pesticides and pesticide metabolites were determined in five rivers of the Mississippi Embayment National Water-Quality Assessment study unit from February 1996 through January 1998. More than 230 samples were collected and analyzed during the 2-year study. The five rivers sampled included three rivers with small, primarily agricultural watersheds; one river with a small urban watershed in Memphis, Tennessee; and one large river with mixed land use (row-crop agriculture, pasture, forest, and urban). Pesticides, usually herbicides, were frequently detected in water samples from every river. Insecticides were frequently detected (chlorpyrifos and diazinon in all samples) only in the river that drains the urban watershed. The occurrence of pesticides in surface water varied among the agricultural watersheds as well as between the agricultural and urban watersheds. The pesticides detected in the rivers that drain the agricultural watersheds were related to the major crop types cultivated in the watershed?corn is mostly grown in the northern part of the study unit, whereas cotton and rice are mostly grown in the southern part. The occurrence of pesticides in the Yazoo River, which drains the mixed land-use watershed, was similar to pesticide occurrence in the rivers that drain smaller agricultural watersheds, although concentrations were lower in the Yazoo River. Likewise, simazine, which was detected in all urban stream samples, was also detected in all Yazoo River samples, but in lower concentrations. The aquatic-life criteria for diazinon and chlorpyrifos was exceeded in 24 of 25 and 12 of 25 urban river samples, respectively, but only once or twice in agricultural and mixed-use watershed samples. Atrazine exceeded the aquatic-life criterion in about 20 percent of the samples from each river, particularly in the spring following pesticide application.

  6. Structure and development of the Southeast Georgia Embayment and northern Blake Plateau: preliminary analysis

    USGS Publications Warehouse

    Dillon, William P.; Paull, Charles K.; Buffler, Richard T.; Fail, Jean-Pierre

    1979-01-01

    Multichannel seismic reflection profiles from the Southeast Georgia Embayment and northern Blake Plateau show reflectors that have been correlated tentatively with horizons of known age. The top of the Cretaceous extends smoothly seaward beneath the continental shelf and Blake Plateau, unaffected at the present shelf edge. A reflector inferred to correspond approximately to the top of the Jurassic section onlaps and pinches out against rocks below. A widespread smooth reflector probably represents a volcanic layer of Early Jurassic age that underlies only the northwestern part of the research area. A major unconformity beneath the inferred volcanic layer is probably of Late Triassic or Early Jurassic age. This unconformity dips rather smoothly seaward beneath the northern Blake Plateau, but south of a geological boundary near 31°N, it has subsided much more rapidly, and reaches depths of more than 12 km. Development of the continental margin north of the boundary began with rifting and subsidence of continental basement in the Triassic. An episode of volcanism may have been due to stresses associated with a spreading center jump at about 175 million years ago. Jurassic and Cretaceous deposits form an onlapping wedge above the inferred early Jurassic volcanics and Triassic sedimentary rocks. During Cenozoic times, development of Gulf Stream flow caused a radical decrease in sedimentation rates so that a shelf that was much narrower than the Mesozoic shelf was formed by progradation against the inner edge of the stream. South of the 31°N geological boundary, the basement probably is semi-oceanic and reef growth, unlike that in the area to the north, has been very active at the outer edge of the plateau.

  7. Sedimentology of an early Cambrian tide-dominated embayment: Quyuk formation, Victoria Island, Arctic Canada

    NASA Astrophysics Data System (ADS)

    Durbano, Andrew M.; Pratt, Brian R.; Hadlari, Thomas; Dewing, Keith

    2015-05-01

    The early Cambrian (series 2, stage 4) Quyuk formation is exposed in the Minto Inlier of western Victoria Island, Canadian Arctic Islands, and forms the base of the Phanerozoic succession. Coeval with other sandstones of this age in Laurentia, it was deposited in a shallow-marine embayment on a passive margin during the initial phase of the early Paleozoic transgression. Four facies associations are recognized: (1) offshore muds consisting dominantly of dark gray laminated mudstone with discontinuous laminae of medium- to coarse sand; (2) offshore sand dune fields characterized by laterally continuous, planar cross-stratified beds up to 1.4 m thick of medium- to coarse-grained sandstone; (3) distal nearshore consisting dominantly of fine- to medium-grained bioturbated sandstone and fine- to medium-grained sandstone interbedded with laminated mudstone; and (4) proximal nearshore characterized by laterally continuous fine- to medium-grained bioturbated sandstone and medium-grained oolitic ironstone. Large scale dunes of facies association 2 record areas where tidal currents were amplified and had available sediment supply in contrast to facies association 1, which was sediment starved. Dunes are, for the most part, non-bioturbated or contain just a few individual burrows belonging to Skolithos. In nearshore settings, bioturbation in the form of a typical early Cambrian suite of shallow-subtidal ichnofossils predominated, representing a low-diversity Cruziana ichnofacies. Oolitic ironstone horizons in the proximal nearshore mark periods of low sedimentation rates when iron became concentrated and calcite was the primary cementing agent. The coastline is envisaged as a complex of bays and lagoons.

  8. Coupled ice-flow/ocean circulation modeling in the Amundsen Sea Embayment using ISSM and MITgcm.

    NASA Astrophysics Data System (ADS)

    Larour, E. Y.; Menemenlis, D.; Schodlok, M.

    2014-12-01

    the West Antarctic Ice Sheet is thought to be prone to marine instability in which prolonged grounding line retreat could occur due to inland downwards sloping bedrocks. However, this instability is difficult to model in part due to the absence of good parameterizations for melt-rates under ice-shelves, in particular near or at the grounding-line, where a complex interplay between butressing, melt-rate, water-pressure and internal stresses in the ice develops. In order to simulate such melt rates accurately, ice-sheet models need to be fully coupled to ocean models, in order to capture the feedback mechanisms between heat-flux at the ice/ocean interface and cavity shape driven by grounding-line retreat.Here, we show an example of such a coupling between the Ice Sheet System Model (ISSM) and the MIT General Circulation Model (MITgcm). The goal is to run sensitivity studies of the evolution of Pine Island Glacier in West Antarctica. We quantify the impact of feedbacks between both systems by running short transients (20-100 years) of the coupled ice-sheet flow/ocean circulation model. We vary inputs such as far-field temperature of the Circumpolar Deep-Water, surface temperature of the Amundsen Sea Embayment, and far-field surface ice-flow velocity. Preliminary insights into the variability of the system are presented, as well as quantified impacts of variations in model inputs.This work was performed at the California Institute of Technology's Jet Propulsion Laboratory undera contract with the National Aeronautics and Space Administration's Cryosphere Science Program.

  9. Post-glacial thinning history of the Foundation Ice Stream, Weddell Sea embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Bentley, M.; Hein, A. S.; Sugden, D. E.; Whitehouse, P.; Vieli, A.; Hindmarsh, R. C.

    2012-12-01

    The Antarctic ice sheet is the largest on earth and any instability is likely to dominate global sea level change. We therefore require models of the ice sheet to make more reliable and robust predictions of future change. One problem in meeting this challenge is the lack of past data on deglaciation with which to initialize and calibrate the models. This problem has been particularly acute in the Weddell Sea embayment and in particular its eastern part where the Foundation - Thiel Trough has been a principal drainage route for the West Antarctic Ice Sheet (WAIS), and its southern extension may be a potential location for future instability. Two significantly different models of glacial history have been proposed for the trough. The first, based largely on marine geology suggests that grounded ice extended to the continental shelf at the Last Glacial Maximum (LGM), filling the Foundation-Thiel trough. The second, based largely on terrestrial glacial geology suggests a much more restricted advance of ice in the trough with relatively minor or even zero thickening of the ice sheet onshore. Here we present new glacial geologic data from the margins of the Foundation Ice Stream, which currently occupies the southern extension of the trough. We sampled erratic clasts from several nunataks along > 100km transect of the ice stream, and will present the 10Be ages on these clasts. The data show several hundred metres of thinning occurred along the lower Foundation Ice Stream and its tributary the Academy Glacier in the Holocene. We discuss the implications for the competing models of LGM and post-LGM glacial history.

  10. Chagas Disease Risk in Texas

    PubMed Central

    Sarkar, Sahotra; Strutz, Stavana E.; Frank, David M.; Rivaldi, Chissa–Louise; Sissel, Blake; Sánchez–Cordero, Victor

    2010-01-01

    Background Chagas disease, caused by Trypanosoma cruzi, remains a serious public health concern in many areas of Latin America, including México. It is also endemic in Texas with an autochthonous canine cycle, abundant vectors (Triatoma species) in many counties, and established domestic and peridomestic cycles which make competent reservoirs available throughout the state. Yet, Chagas disease is not reportable in Texas, blood donor screening is not mandatory, and the serological profiles of human and canine populations remain unknown. The purpose of this analysis was to provide a formal risk assessment, including risk maps, which recommends the removal of these lacunae. Methods and Findings The spatial relative risk of the establishment of autochthonous Chagas disease cycles in Texas was assessed using a five–stage analysis. 1. Ecological risk for Chagas disease was established at a fine spatial resolution using a maximum entropy algorithm that takes as input occurrence points of vectors and environmental layers. The analysis was restricted to triatomine vector species for which new data were generated through field collection and through collation of post–1960 museum records in both México and the United States with sufficiently low georeferenced error to be admissible given the spatial resolution of the analysis (1 arc–minute). The new data extended the distribution of vector species to 10 new Texas counties. The models predicted that Triatoma gerstaeckeri has a large region of contiguous suitable habitat in the southern United States and México, T. lecticularia has a diffuse suitable habitat distribution along both coasts of the same region, and T. sanguisuga has a disjoint suitable habitat distribution along the coasts of the United States. The ecological risk is highest in south Texas. 2. Incidence–based relative risk was computed at the county level using the Bayesian Besag–York–Mollié model and post–1960 T. cruzi incidence data. This risk

  11. Evolution of Permian evaporite basin in Texas panhandle

    SciTech Connect

    Presley, M.W. )

    1987-02-01

    Permian (Leonardian to Ochoan) evaporites in the Texas Panhandle were deposited in a range of marine shelf to supratidal environments along an arid coastline. Carbonates in these strata generally were deposited in inner shelf systems and include subtidal to supratidal facies. Landward of shelf environments, evaporites were deposited in brine pans and salt flats. Brine-pan facies are laminated anhydrite and banded salt that formed in shallow, hypersaline water such as restricted lagoons or supratidal salines. Salt-flat facies are mainly chaotic mixtures of mudstone and halite possibly formed by salt deposition on and within mud flats that bordered brine pans, or in brine-soaked mud-flat depressions. Periodically, mud flats built across the evaporite systems and were supplied with red terrestrial clastics, mainly mud and silt. These facies occur together in at least three different types of lithogenetic units. Strata in the Clear Fork Group (Leonardian) are considered deposits of a coastal evaporite basin that was progressively filled by terrestrial clastics. These rocks exhibit regressive cycles of brine-pan, salt-flat, and mud-flat facies. In contrast, San Andres strata (Guadalupian) were deposited in a broad marine embayment with persistent brine-pan conditions, and contain cycles of inner shelf and brine-pan facies. Post-San Andres strata (late Guadalupian and Ochoan) were deposited in the inner reaches of a broad interior salt basin and are composed mainly of mud-flat, salt-flat, and halite-rich brine-pan facies. 20 figs., 2 tabs.

  12. Paleohydrology of Southwestern Texas

    NASA Astrophysics Data System (ADS)

    Kochel, R. Craig; Baker, Victor R.; Patton, Peter C.

    1982-08-01

    Current statistical methods may be unable to accurately predict recurrence intervals of rare, large-magnitude floods, especially in semiarid regions having positively skewed annual flood distributions, great hydrologic variability, and widely spaced gaging stations. Current approaches rely on historical data, but catastrophic floods may have recurrence intervals far greater than the length of historical records. In the lower Pecos and Devils Rivers of southwestern Texas, paleoflood discharge and frequency estimates are extended over 10,000 years by the study of slack-water flood sediments. Slack-water deposits are typically fine-grained sand and silt that accumulate during floods in areas where current velocity is reduced, i.e., in back-flooded tributary mouths, channel expansions, downstream from bedrock spurs and/or slump blocks, and in shallow caves along bedrock walls. Radiocarbon dating of organic detritus in slack-water deposits establishes the flood chronology while paleoflood discharges can be estimated by slope-area techniques. Paleoflood information extracted from slack-water sediments can greatly extend flood records. These floods may be weighted like historical data in log Pearson type 3 calculations of flood frequency. Our morphostratigraphic approach combines recorded data with geomorphic evidence to derive estimates of flood frequency. This technique offers an inexpensive and rapid way to assess catastrophic flood risk.

  13. Regional Haze Plan for Texas and Oklahoma

    EPA Pesticide Factsheets

    EPA partially approved and partially disapproved the Texas regional haze plan. EPA also finalized a plan to limit sulfur dioxide emissions from eight Texas coal-fired electricity generating facilities

  14. Libraries in Texas: MedlinePlus

    MedlinePlus

    ... on this page, please enable JavaScript. Amarillo Texas Tech University Health Sciences Center Harrington Library of the ... bell_parrish_medical_libr.asp El Paso Texas Tech University Health Sciences Center at El Paso Gallo ...

  15. Solar domestic hot water system installed at Texas City, Texas

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This is the final technical report of the solar energy system located at LaQuinta Motor Inn, Texas City, Texas. The system was designed to supply 63 percent of the total hot water load for a new 98 unit motor inn. The solar energy system consists of a 2100 square feet Raypack liquid flat plate collector subsystem and a 2500 gallon storage subsystem circulating hot water producing 3.67 x 10 to the 8th power Btu/year. Abstracts from the site files, specification references, drawings, installation, operation, and maintenance instructions are included.

  16. Campanian coastal plain sediments in southeastern Missouri and southern Illinois - Significance to the early geologic history of the northern Mississippi Embayment

    USGS Publications Warehouse

    Harrison, R.W.; Litwin, R.J.

    1997-01-01

    Basal Cretaceous deposits in the northernmost part of the Mississippi Embayment in southeastern Missouri and southern Illinois have been correlated previously with the Tuscaloosa Formation of Alabama. New palynological data indicate that these clastic deposits comprise non-marine and marine sections of middle to late Campanian age. They consist of a lower non-marine deposit, the herein newly proposed Post Creek Formation, and an upper marine deposit that we correlate in part with the Coffee Sand of Tennessee. These Campanian deposits overlie a diachronous Mesozoic paleosol, Little Bear Formation, and are progressively overlain by the McNairy Sand of early to middle Maastrichtian age, the Owl Creek Formation of middle to late Maastrichtian age, and the Porters Creek Clay of late Paleocene age. Outcrops and subsurface occurrences of the Post Creek Formation are widespread around the northern margin of the Mississippi Embayment. In contrast, the Coffee Sand is more restricted in distribution, and is present in southeast Missouri only as an outlier. Extensive occurrences of the Coffee Sand are found in Tennessee and further south in the embayment. This study shows that (1) the basal Cretaceous deposits in the northern Mississippi Embayment are not equivalent to the Tuscaloosa Formation, but are entirely separate stratigraphic units, (2) the shallow Cretaceous Interior Seaway occupied the northernmost part of the present Mississippi Embayment by the late Campanian, and (3) a large part of the northern embayment may have experienced an episode of uplift and erosion during the latest Campanian or earliest Maastrichtian, prior to deposition of McNairy Sand. ?? 1997 Academic Press Limited.

  17. Coolwater culmination: Sensitive high-resolution ion microprobe (SHRIMP) U-Pb and isotopic evidence for continental delamination in the Syringa Embayment, Salmon River suture, Idaho

    USGS Publications Warehouse

    Lund, K.; Aleinikoff, J.N.; Yacob, E.Y.; Unruh, D.M.; Fanning, C.M.

    2008-01-01

    During dextral oblique translation along Laurentia in western Idaho, the Blue Mountains superterrane underwent clockwise rotation and impinged into the Syringa embayment at the northern end of the Salmon River suture. Along the suture, the superterrane is juxtaposed directly against western Laurentia, making this central Cordilleran accretionary-margin segment unusually attenuated. In the embayment, limited orthogonal contraction produced a crustal wedge of oceanic rocks that delaminated Laurentian crust. The wedge is exposed through Laurentian crust in the Coolwater culmination as documented by mapping and by sensitive high-resolution ion microprobe U-Pb, Sri, and ??Nd data for gneisses that lie inboard of the suture. The predominant country rock is Mesoproterozoic paragneiss overlying Laurentian basement. An overlying Neoproterozoic (or younger) paragneiss belt in the Syringa embayment establishes the form of the Cordilleran miogeocline and that the embayment is a relict of Rodinia rifting. An underlying Cretaceous paragneiss was derived from arc terranes and suture-zone orogenic welt but also from Laurentia. The Cretaceous paragneiss and an 86-Ma orthogneiss that intruded it formed the wedge of oceanic rocks that were inserted into the Laurentian margin between 98 and 73 Ma, splitting supracrustal Laurentian rocks from their basement. Crustal thickening, melting and intrusion within the wedge, and folding to form the Coolwater culmination continued until 61 Ma. The embayment formed a restraining bend at the end of the dextral transpressional suture. Clockwise rotation of the impinging superterrane and overthrusting of Laurentia that produced the crustal wedge in the Coolwater culmination are predicted by oblique collision into the Syringa embayment. Copyright 2008 by the American Geophysical Union.

  18. ""Una Persona Derechita" (Staying Right in the Mind)": Perceptions of Spanish-Speaking Mexican American Older Adults in South Texas "Colonias"

    ERIC Educational Resources Information Center

    Sharkey, Joseph R.; Sharf, Barbara F.; St. John, Julie A.

    2009-01-01

    Purpose: This study describes the perceptions of brain health among older Spanish-speaking Mexican Americans who reside in colonia areas of the Lower Rio Grande Valley of Texas. Design and Methods: In 2007, 33 Mexican American older adults (9 men and 24 women) were recruited by "promotoras" (community health workers) from clusters of…

  19. Geologic Map Database of Texas

    USGS Publications Warehouse

    Stoeser, Douglas B.; Shock, Nancy; Green, Gregory N.; Dumonceaux, Gayle M.; Heran, William D.

    2005-01-01

    The purpose of this report is to release a digital geologic map database for the State of Texas. This database was compiled for the U.S. Geological Survey (USGS) Minerals Program, National Surveys and Analysis Project, whose goal is a nationwide assemblage of geologic, geochemical, geophysical, and other data. This release makes the geologic data from the Geologic Map of Texas available in digital format. Original clear film positives provided by the Texas Bureau of Economic Geology were photographically enlarged onto Mylar film. These films were scanned, georeferenced, digitized, and attributed by Geologic Data Systems (GDS), Inc., Denver, Colorado. Project oversight and quality control was the responsibility of the U.S. Geological Survey. ESRI ArcInfo coverages, AMLs, and shapefiles are provided.

  20. Texas Migrant Labor. Annual Report, 1969.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    Among the responsibilities of the Good Neighbor Commission of Texas are (1) a survey of conditions and (2) a study of problems related to migrant labor in Texas. This annual report of the 1969 migrant scene shows the results of that survey and study. Beginning with an overview of Texas migrant labor, which goes back several years and includes a…

  1. Texas Emergency Resource Management. Volume I.

    DTIC Science & Technology

    1979-09-30

    and the transportation of essential supplies such as food and medical . FINDINGS 1. Basic operational concepts contain.d in the Texas Emer- gency...19. (Cont.) Economic Stabilization Health and Medical Petroleum, Gas and Solid Fuel Electric Power, Water Industrial Production Manpower...Government - State of Texas Emergency Resources Management Organization, Health and Medical , State to Local Government - State of Texas Emergency Resources

  2. Ready Texas: Stakeholder Convening. Proceedings Report

    ERIC Educational Resources Information Center

    Intercultural Development Research Association, 2016

    2016-01-01

    With the adoption of substantial changes to Texas high school curricula in 2013 (HB5), a central question for Texas policymakers, education and business leaders, families, and students is whether and how HB5 implementation impacts the state of college readiness and success in Texas. Comprehensive research is needed to understand the implications…

  3. Texas Real Estate Curriculum Workshop Summary Report.

    ERIC Educational Resources Information Center

    Lyon, Robert

    The Texas Real Estate Research Center-Texas Education Agency (TRERC-TEA) curriculum workshop was attended by over 40 participants representing 26 Texas community colleges. These participants divided into eight small groups by real estate specialty area and developed curriculum outlines and learning objectives for the following real estate courses:…

  4. Overview of the Texas Youth Fitness Study

    ERIC Educational Resources Information Center

    Morrow, James R., Jr.; Martin, Scott B.; Welk, Gregory J.; Zhu, Weimo; Meredith, Marilu D.

    2010-01-01

    This paper summarizes the historical and legislative backgrounds leading to statewide testing of health-related physical fitness in Texas children grades 3-12 as mandated by Texas Senate Bill 530. The rationale and goals for an associated research project (the Texas Youth Fitness Study, funded by the Robert Wood Johnson Foundation) to evaluate…

  5. The Demographics of Corporal Punishment in Texas

    ERIC Educational Resources Information Center

    Phillips, Stephanie

    2012-01-01

    This dissertation examined the student discipline policies of 1,025 Texas school districts, as well as data from the Texas Education Agency's Academic Excellence Indicator System in order to identify demographic patterns regarding corporal punishment policies in Texas schools. The study also studied the relationship between a district's corporal…

  6. Testing in Texas: Accountability for Bilingual Students.

    ERIC Educational Resources Information Center

    Porter, Rosalie Pedalino, Ed.

    2000-01-01

    This issue has a special, multi-article section on student testing in Texas and contains three additional and unrelated articles. "The Texas Testing Case Documents: G.I. Forum, et al. v. Texas Education Agency, et al." section has five articles: "Overview" (Roger Clegg); a copy of the "First Amended Complaint";…

  7. In Texas, a Statewide Commitment to Transfer

    ERIC Educational Resources Information Center

    Jacobs, Bonita C.; Cutright, Marc

    2010-01-01

    The Texas Transfer Success Conference, held at eight sites across Texas in May 2009, drew more than 1,000 attendees from Texas and international colleges and universities. The purpose of the conference was to discuss strategies and principles for increasing the effectiveness of inter-institutional transfer for students. The conference was planned…

  8. Research on Texas Water and Recreation Resources.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Texas Agricultural Experiment Station.

    The need for research pertaining to the best use of water and recreation resources in Texas is emphasized in these four papers presented at the 1968 Experiment Station Conference, College Station, Texas. "Parameters of Water Resources in Texas" identifies and elaborates upon the important elements presently constituting the water…

  9. Habitat partitioning by five congeneric and abundant Choerodon species (Labridae) in a large subtropical marine embayment

    NASA Astrophysics Data System (ADS)

    Fairclough, D. V.; Clarke, K. R.; Valesini, F. J.; Potter, I. C.

    2008-04-01

    The habitats occupied by the juveniles and adults of five morphologically similar, diurnally active and abundant Choerodon species in the large subtropical environment of Shark Bay, a "World Heritage Property" on the west coast of Australia, have been determined. The densities of the two life cycle stages of each Choerodon species in those habitats were used in various analyses to test the hypotheses that: (1) habitats are partitioned among these species and between their juveniles and adults; (2) such habitat partitioning is greatest in the case of the two Western Australian endemic species, i.e. Choerodon rubescens and Choerodon cauteroma; and (3) the extent of habitat partitioning between both of these two species and the only species that is widely distributed in the Indo-West Pacific, i.e. Choerodon schoenleinii, will be less pronounced. Initially, catches of each of the five congeneric species, obtained during other studies in Shark Bay by angling, spearfishing and otter trawling, were collated to elucidate the broad distribution of these species in that embayment. Underwater visual census was then used to determine the densities of the juveniles and adults of each Choerodon species at sites representing the four habitat types in which one or more of these species had been caught, i.e. reefs in marine waters at the western boundary of the bay and seagrass, reefs and rocky shorelines in the two inner gulfs. The compositions of the Choerodon species over marine (entrance channel) reefs and in seagrass were significantly different and each differed significantly from those in both inner gulf reefs and rocky shorelines, which were, however, not significantly different. Choerodon rubescens was restricted to exposed marine reefs, and thus occupied a different habitat and location of the bay than C. cauteroma, the other endemic species, which was almost exclusively confined to habitats found in the inner gulfs. Choerodon cauteroma differed from other Choerodon

  10. Neogene Seismic Stratigraphic Framework and Fill History of the Northeastern Albemarle Embayment, North Carolina

    NASA Astrophysics Data System (ADS)

    Mallinson, D. J.; Riggs, S. R.; Thieler, R.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.; Wehmiller, J.; Foster, D. S.

    2002-12-01

    Seismic and chirp sonar surveys were conducted in the eastern Albemarle Sound and adjacent tributaries and the inner continental shelf to define the geologic framework and evolution of the North Carolina coastal system. Surveys were utilized to target paleofluvial channels for drilling and core recovery for the assessment of sea level and climate change during the Quaternary. Lithostratigraphic and chronostratigraphic data are derived from eight drill sites on the Outer Banks, and the Mobil #1 well in the eastern Albemarle Sound. Within the study area, parallel-bedded, gently dipping Miocene beds occur at 100 to >180 mbsl, and are overlain by a southward-thickening Pliocene unit characterized by steeply inclined southward-prograding beds. The Quaternary section unconformably overlies the Pliocene unit, and consists of at least five depositional sequences exhibiting numerous incised channel-fill facies. The Quaternary section is 55 to 60 meters thick. Shallow stratigraphy (0-50 mbsl) is dominated by complex fill-stratigraphy within the incised paleo-Roanoke River valley. Radiocarbon and amino acid racemization (AAR) dates indicate that the valley-fill is late Pleistocene to Holocene in age. At least 6 distinct valley-fill units are identified in the seismic data based upon reflection geometry. Cores reveal a 3 to 6 meter thick basal fluvial channel lag that is overlain by a 15-meter thick unit of interbedded freshwater muds and sands. Organic materials within the freshwater deposits have ages of 13-11 cal. ka, and are overlain by several units comprised of shallow marine sediments. Shallow marine sediments within the valley are silty, fine- to medium-grained sands containing abundant neritic forams, suggesting that this area was an open embayment during much of the Holocene. Seismic data reveal that initial infilling occurred from the north and west during the late Pleistocene and early Holocene. Later infilling occurred from the east and is characterized by a large

  11. Late Neogene and Quaternary evolution of the northern Albemarle Embayment (mid-Atlantic continental margin, USA)

    USGS Publications Warehouse

    Mallinson, D.; Riggs, S.; Thieler, E.R.; Culver, S.; Farrell, K.; Foster, D.S.; Corbett, D.R.; Horton, B.; Wehmiller, J. F.

    2005-01-01

    Seismic surveys in the eastern Albemarle Sound, adjacent tributaries and the inner continental shelf define the regional geologic framework and provide insight into the sedimentary evolution of the northern North Carolina coastal system. Litho- and chronostratigraphic data are derived from eight drill sites on the Outer Banks barrier islands, and the Mobil #1 well in eastern Albemarle Sound. Within the study area, parallel-bedded, gently dipping Miocene beds occur at 95 to > 160 m below sea level (m bsl), and are overlain by a southward-thickening Pliocene unit characterized by steeply inclined, southward-prograding beds. The lower Pliocene unit consists of three seismic sequences. The 55-60 m thick Quaternary section unconformably overlies the Pliocene unit, and consists of 18 seismic sequences exhibiting numerous incised channel-fill facies. Shallow stratigraphy (< 40 m bsl) is dominated by complex fill patterns within the incised paleo-Roanoke River valley. Radiocarbon and amino-acid racemization (AAR) ages indicate that the valley-fill is latest Pleistocene to Holocene in age. At least six distinct valley-fill units are identified in the seismic data. Cores in the valley-fill contain a 3-6 m thick basal fluvial channel deposit that is overlain by a 15 m thick unit of interlaminated muds and sands of brackish water origin that exhibit increasing marine influence upwards. Organic materials within the interlaminated deposits have ages of 13-11 cal. ka. The interlaminated deposits within the valley are overlain by several units that comprise shallow marine sediments (bay-mouth and shoreface environments) that consist of silty, fine- to medium-grained sands containing open neritic foraminifera, suggesting that this area lacked a fronting barrier island system and was an open embayment from ???10 ka to ???4.5 ka. Seismic data show that initial infilling of the paleo-Roanoke River valley occurred from the north and west during the late Pleistocene and early Holocene

  12. Comparative diel feeding ecology of brook silverside, golden shiner, and subyearling pumpkinseed in a Lake Ontario embayment during summer

    USGS Publications Warehouse

    Johnson, James H.; Chalupnicki, Marc; Abbett, Ross; Diaz, Avriel R; Nack, Christopher C

    2017-01-01

    Fish feeding ecology has been shown to vary over a 24-h period in terms of the prey consumed and feeding intensity. Consequently, in order to best determine the interspecific feeding associations within a fish community, examination of the diet at multiple times over a 24-h period is often necessary. We examined the diel feeding ecology of three fish species that were numerically dominant in a Lake Ontario embayment during summer. The diet of each of the three species, subyearling pumpkinseed Lepomis gibbosus, golden shiner Notemigonus crysoleucus, and brook silverside Labidesthes sicculus, was distinct with no significant overlap in diet composition occurring within any of the 4-h time intervals. The diet composition of each species suggested that brook silverside were feeding at the surface (terrestrial invertebrates and aquatic surface dwelling hemipterans) whereas subyearling pumpkinseed (amphipods) and golden shiner (tipulids) were feeding on different benthic prey. Differences in feeding periodicity were most pronounced for subyearling pumpkinseed. Our findings provide valuable insights on interspecific feeding associations among these three fish species during summer in a Lake Ontario embayment.

  13. Hydrogeologic setting and the potentiometric surfaces of regional aquifers in the Hollandale Embayment, southeastern Minnesota, 1970-80

    USGS Publications Warehouse

    Delin, G.N.; Woodward, D.G.

    1984-01-01

    Potentiometric-surface maps for each aquifer indicate that movement of ground water is predominantly toward the major rivers. The St. Croix, Minnesota, and Mississippi Rivers constitute regional discharge boundaries for ground-water flow. A major ground-water divide in the St. Peter, Prairie du Chien-Jordan, Ironton-Galesville, and Mount Simon-Hinckley aquifers in the south-central part of the Hollandale embayment separates ground-water flow northward toward the Twin Cities area and southward toward Iowa. The St. Peter and Prairie du Chien-Jordan aquifers in the southeastern part of the embayment contain ground-water mounds as high as 90 ft above the regional potentiometric surface. The mounds occur as a result of increased recharge where the Decorah-Platteville-Glenwood confining bed has been removed by erosion and the aquifers subcrop beneath drift that is about 20 ft thick. This head distribution produces a locally complex pattern of flow in which ground water moves southwesterly toward Iowa instead of directly toward the Mississippi River.

  14. Seismic anisotropy beneath the Mississippi Embayment and the New Madrid Seismic Zone: A study of shear wave splitting

    NASA Astrophysics Data System (ADS)

    Nyamwandha, Cecilia A.; Powell, Christine A.

    2016-11-01

    Shear wave splitting associated with the Mississippi Embayment (ME) is determined using teleseismic SKS phases recorded by the Northern Embayment Lithosphere Experiment (NELE), the USArray Transportable Array (TA), and the New Madrid seismic network for the period 2005-2016. Our data set consists of 5900 individual splitting measurements from 257 earthquakes recorded at 151 stations within and outside the ME. Stations outside of the ME exhibit significant shear wave splitting, with average delay times between 0.4 s and 1.8 s. To the northeast and east of the ME, nearly all observed fast orientations are approximately oriented northeast-southwest, in agreement with absolute plate motion (APM) predicted by HS3-Nuvel-1A. The homogeneity of the fast orientations in this region suggests that the splitting is due to active flow in the asthenosphere. A counterclockwise rotation in the splitting orientation is observed moving northeast to northwest across the study area. Inside the ME, some stations show large and systematic deviations of the measured fast orientations from the APM. The delay times within the entire ME range from 0.9 s to 2.1 s. Splitting complexity is attributed to relic lithospheric fabrics formed during past tectonic events including passage of a hot spot in mid-Cretaceous time. The anisotropy may also be linked to the presence of a southwest dipping region of low P and S wave velocities below the ME or to deeper flow in the asthenosphere.

  15. The State of Texas Children: 2003. Texas Kids Count.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Center for Public Policy Priorities.

    This Kids Count report details trends in the well-being of children in Texas. The statistical portrait is based on indicators in the areas of: (1) family and community population; (2) economic resources, security, and opportunity; (3) early care and education; (4) school success; (5) teens at risk; (6) physical, social, and emotional health; (7)…

  16. Thomas Moran: "The Grand Canyon."

    ERIC Educational Resources Information Center

    Brubaker, Ann

    1986-01-01

    Presents a lesson plan for introducing students in grades four through six to Thomas Moran's painting, "The Grand Canyon." The goal of the lesson is to illustrate the importance of the American West as a subject for artists in the nineteenth century. (JDH)

  17. Long-term deformation in the Mississippi Embayment (Central USA) imaged by high-resolution seismic reflection data

    NASA Astrophysics Data System (ADS)

    Hao, Yanjun

    Large magnitude intraplate earthquakes are a puzzling exception to plate tectonic theory. Unlike earthquakes occurring along plate boundaries, large continental intraplate earthquakes are a rare occurrence and are often distributed over broad regions. Albeit rare, their occurrence can cause widespread damage because of the low attenuation of seismic energy typical of plate interiors [Hanks and Johnston, 1992]. In the Central USA, most of the recent tectonic intraplate seismicity concentrates along the New Madrid seismic zone (NMSZ), where three large (M>7) earthquakes occurred between 1811--1812 [Johnston and Schweig, 1996]. Here the low surface deformation rates [Calais and Stein, 2009] conflict with the elevated instrument-recorded seismicity and the occurrence of historical and prehistorical large magnitude events [Tuttle et al., 2002]. One of the promising hypotheses proposed to reconcile this apparent contradiction is that intraplate earthquakes may be temporally clustered, episodic or cyclic, and may migrate spatially at the regional or continental scale across multiple faults or fault systems. In order to test this hypothesis and to understand how and where the long-term deformation is accommodated in the Mississippi Embayment, Central USA, I utilize high-resolution seismic reflection data acquired by the Mississippi River Project [Magnani and McIntosh, 2009] and by a 2010 survey across the Meeman-Shelby fault [Magnani, 2011; Hao et al., 2013]. To identify the location of Quaternary deformation and characterize deformation history, I acquired, processed, and interpreted the seismic reflection data and integrated them with other available geophysical (e.g. seismicity, crustal and lithospheric models) and geological (e.g. magmatism and borehole) data. For my research, I focus on three regions in the Mississippi Embayment: 1) the Meeman-Shelby fault west of Memphis, Tennessee, 2) the eastern Reelfoot rift margin north of Memphis, Tennessee, and 3) the area in

  18. Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport (Partnerships in Computational Science)

    SciTech Connect

    Celia, M.A.

    1999-03-11

    The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the Princeton University component of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1998. Seven institutions were primarily involved in this project: Brookhaven National Laboratory, Oak Ridge National Laboratory, Princeton University, SUNY at Stony Brook, Texas A&M University, The University of South Carolina, and the University of Texas at Austin, with contributing efforts from the Westinghouse Savannah River Technology Center. Each institution had primary responsibility for specific research components, but strong collaboration among all institutions was essential for the success of the project and in producing the final deliverables. PICS deliverables include source code for the suite of research simulators and auxiliary HPC tools, associated documentation, and test problems. These materials will be available as indicated from each institution's web page or from the Center for Computational Sciences Oak Ridge National Laboratory in January 1998.

  19. Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport (Partnerships in Computational Science)

    SciTech Connect

    Sharpley, Robert C.

    1997-12-01

    The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the University of South Carolina component of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997. Seven institutions were primarily involved in this project: Brookhaven National Laboratory, Oak Ridge National Laboratory, Princeton University, SUNY at Stony Brook, Texas A&M University, The University of South Carolina, and the University of Texas at Austin, with contributing efforts from the Westinghouse Savannah River Technology Center. Each institution had primary responsibility for specific research components, but strong collaboration among all institutions was essential for the success of the project and in producing the final deliverables. PICS deliverables include source code for the suite of research simulators and auxiliary HPC tools, associated documentation, and test problems. These materials will be available as indicated from each institution's web page or from the Center for Computational Sciences Oak Ridge National Laboratory in January 1998.

  20. Simulation of the effects of groundwater withdrawals on water-level altitudes in the Sparta aquifer in the Bayou Meto-Grand Prairie area of eastern Arkansas, 2007-37

    USGS Publications Warehouse

    Clark, Brian R.; Westerman, Drew A.; Fugitt, D. Todd

    2011-01-01

    A groundwater-flow model of the Mississippi embayment was used to evaluate changes in water-level altitudes before (scenario 1) and after (scenario 2) the addition of wells that simulate potential future pumping from the Sparta aquifer in the Bayou Meto-Grand Prairie area of eastern Arkansas for the 30-year period from 2007 through 2037. Water-level altitudes at six model cell locations from the two different scenarios were compared for the period 2007 through 2037. Potential future pumping wells were added to the Mississippi Embayment Regional Aquifer Study model at a rate of 13 wells per year within areas of potential future pumping. Change maps for the Bayou Meto-Grand Prairie area were constructed for each scenario and water-level hydrographs were constructed for each scenario for each of the six model cell locations. The additional pumping from wells in the Sparta aquifer created greater water-level declines in the Bayou Meto-Grand Prairie area. In scenario 1, simulated water-level altitude declines range from 20 to 40 feet from 2007 through 2037. In scenario 2, the cone of depression in Lonoke County is the deepest, with a maximum water-level decline of approximately 102 feet. Water-level altitude declines range from 40 to 50 feet over most of the remainder of the Bayou Meto-Grand Prairie area in scenario 2. Simulated water-level altitudes across the Bayou Meto-Grand Prairie area and at all six model cell locations indicate substantial declines when additional wells pumping from the Sparta aquifer are introduced into the model from 2007 through 2037.

  1. A comparative assessment of contaminants in fish from four resacas of the Texas, USA-Tamaulipas, Mexico border region.

    PubMed

    Mora, M A; Papoulias, D; Nava, I; Buckler, D R

    2001-07-01

    A recent survey of contaminant information for the Lower Rio Grande Valley (LRGV), Texas, has shown that little is known about contaminants and their impacts on biota of resacas (oxbows) along the US-Mexico border. In 1996, fish were collected from four resacas in the Texas-Tamaulipas border region to assess contaminant loadings and their impacts on fish and birds. Tissue residue concentrations in fish were analyzed and also compared to two histopathological bioindicators of unhealthy environmental conditions. Of the organochlorine insecticides measured, DDE was the most common and was present at relatively high concentrations (10 microg/g w/w) at some sites. DDE concentrations were nearly 20 times greater in fish from resacas in Texas than from resacas in Tamaulipas, although the limited sample sizes obtained precluded statistical comparisons. DDE concentrations in fish from the two Texas resacas were also greater than those reported in fish from nearby areas during the 1980s and 1990s. Most trace element concentrations were similar among resacas from Texas and Tamaulipas. Arsenic, however, was two to six times greater in fish from a downtown resaca in Matamoros than in fish from other resacas in Tamaulipas and Texas. The bioindicators, pigment accumulation, and macrophage aggregates (MAs), in general, reflected the contamination indicated by the tissue residues for each site. Overall, it appears that some resacas of the US-Mexico border region are contaminant sinks and could pose potential health or reproductive problems for fish and wildlife, and humans that consume fish from those sites.

  2. "Fisher v. Texas": Strictly Disappointing

    ERIC Educational Resources Information Center

    Nieli, Russell K.

    2013-01-01

    Russell K. Nieli writes in this opinion paper that as far as the ability of state colleges and universities to use race as a criteria for admission goes, "Fisher v. Texas" was a big disappointment, and failed in the most basic way. Nieli states that although some affirmative action opponents have tried to put a more positive spin on the…

  3. How Texas Rewrote Your Textbooks.

    ERIC Educational Resources Information Center

    Moyer, Wayne A.

    1985-01-01

    Reviews issues and events related to adopting high school biology textbooks in Texas. Specific reference is given to the viewpoints of Mel and Norma Gabler. It is argued that factors controlling textbook content should not result from past market forces, but from a permanent science constituency and an informed public. (DH)

  4. A Big LEAP for Texas

    ERIC Educational Resources Information Center

    Phillips, Loraine; Roach, David; Williamson, Celia

    2014-01-01

    In Texas, educators working to coordinate the efforts of fifty community colleges, thirty-eight universities, and six university systems are bringing the resources of the Association of American Colleges and Universities (AAC&U) Liberal Education and America's Promise (LEAP) initiative to bear in order to ensure that the state's nearly 1.5…

  5. Texas Endangered Species Activity Book.

    ERIC Educational Resources Information Center

    Jackson, Kathleen Marie; Campbell, Linda

    This publication is the result of the Texas Parks and Wildlife Division's (TPWD's) commitment to education and the fertile partnerships formed between TPWD biologists and educators. This activity book brings together the expertise and practical knowledge of a classroom teacher with the technical knowledge and skills of a TPWD biologist and artist.…

  6. CBTE: The Nays of Texas

    ERIC Educational Resources Information Center

    Sandoz, Ellis

    1974-01-01

    A heated controversy occurred when the Texas State Board of Education mandated competency based teacher education (CBTE) for all of the State's 66 teacher preparatory institutions. The author, who has led a movement of professional groups seeking an attorney general's ruling against the mandate, argues that this mandate violates the professor's…

  7. Texas A&M University

    ERIC Educational Resources Information Center

    Osters, Sandi

    2009-01-01

    Texas A&M University is a research extensive institution located in College Station. More than 45,000 students attend the university (about 20% are graduate or professional students). Academically, the university is known for its engineering, business, and agricultural and veterinary medicine programs, although there are more than 150 programs…

  8. Antidote: Civic Responsibility. Texas Law.

    ERIC Educational Resources Information Center

    Phi Alpha Delta Law Fraternity International, Washington, DC.

    Designed for middle school through high school students, this unit contains eight lesson plans that focus on Texas state law. The state lessons correspond to lessons in the volume, "Antidote: Civic Responsibility. Drug Avoidance Lessons for Middle School & High School Students." Developed to be presented by educators, law student, or…

  9. South Texas Maquiladora Suppliers Project.

    ERIC Educational Resources Information Center

    Patrick, J. Michael

    This project was undertaken to assist South Texas industries in improving export to nearby Mexican maquiladoras (factories). The maquiladora program is based on co-production by two plants under a single management, one on each side of the border. Activities addressed four objectives: (1) to determine the dollar value, quantity, and source of the…

  10. Texas Educational History: A Bibliography.

    ERIC Educational Resources Information Center

    Conrad, James H., Comp.

    The bibliography provides a comprehensive listing of the literature of Texas educational history up to March, 1978. Objectives are to provide access to the sources and to stimulate interest and research in the field. Over 1050 books, journal articles, pamphlets, theses, and doctoral dissertations are arranged in nine subject sections: General…

  11. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  12. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  13. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  14. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  15. 33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. 100.906 Section 100.906 Navigation and Navigable Waters COAST GUARD... Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI. (a) Regulated Area. All waters of...

  16. Red Tide off Texas Coast

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Red tides (algae) bloomed late this summer along a 300-mile stretch of Texas' Gulf Coast, killing millions of fish and shellfish as well as making some people sick. State officials are calling this the worst red tide bloom in 14 years. The algae produces a poison that paralyzes fish and prevents them from breathing. There is concern that the deadly algae could impact or even wipe out this year's oyster harvest in Texas, which usually peaks during the Thanksgiving and Christmas holidays. The red tides were first observed off the Texas coast in mid-August and have been growing steadily in size ever since. Red tides tend to bloom and subside rapidly, depending upon changes in wind speed and direction, water temperature, salinity, and rainfall patterns (as the algae doesn't do as well in fresher water). This true-color image of the Texas Gulf Coast was acquired on September 29, 2000, by the Moderate-resolution Imaging Spectroradiometer (MODIS) flying aboard NASA's Terra spacecraft. The red tide can be seen as the dark reddish discoloration in the ocean running southwest to northeast along the coast. In this scene, the bloom appears to be concentrated north and east of Corpus Christi, just off Matagorda Island. The image was made at 500-meter resolution using a combination of MODIS' visible bands 1 (red), 4 (green), and 3 (blue). The city of Houston can be seen clearly as the large, greyish cluster of pixels to the north and west of Galveston Bay, which is about mid-way up the coastline in this image. Also visible in this image are plumes of smoke, perhaps wildfires, both to the north and northeast of Houston. For more information about red tides, refer to the Texas Red Tide Web site. Image courtesy Andrey Savtchenko, MODIS Data Support Team, and the MODIS Ocean Team, NASA's Goddard Space Flight Center

  17. Impacts of historic morphology and sea level rise on tidal hydrodynamics in a microtidal estuary (Grand Bay, Mississippi)

    NASA Astrophysics Data System (ADS)

    Passeri, Davina L.; Hagen, Scott C.; Medeiros, Stephen C.; Bilskie, Matthew V.

    2015-12-01

    This study evaluates the geophysical influence of the combined effects of historic sea level rise (SLR) and morphology on tidal hydrodynamics in the Grand Bay estuary, located in the Mississippi Sound. Since 1848, the landscape of the Mississippi Sound has been significantly altered as a result of natural and anthropogenic factors including the migration of the offshore Mississippi-Alabama (MSAL) barrier islands and the construction of navigational channels. As a result, the Grand Bay estuary has undergone extensive erosion resulting in the submergence of its protective barrier island, Grand Batture. A large-domain hydrodynamic model was used to simulate present (circa 2005) and past conditions (circa 1848, 1917, and 1960) with unique sea levels, bathymetry, topography and shorelines representative of each time period. Additionally, a hypothetical scenario was performed in which Grand Batture Island exists under 2005 conditions in order to observe the influence of the island on tidal hydrodynamics within the Grand Bay estuary. Changes in tidal amplitudes from the historic conditions varied. Within the Sound, tidal amplitudes were unaltered due to the open exposed shoreline; however, in semi-enclosed embayments outside of the Sound, tidal amplitudes increased. In addition, harmonic constituent phases were slower historically. The position of the MSAL barrier island inlets influenced tidal currents within the Sound; the westward migration of Petit Bois Island allowed stronger tidal velocities to be centered on the Grand Batture Island. Maximum tidal velocities within the Grand Bay estuary were 5 cm/s faster historically, and reversed from being flood dominant in 1848 to ebb dominant in 2005. If the Grand Batture Island was reconstructed under 2005 conditions, tidal amplitudes and phases would not be altered, indicating that the offshore MSAL barrier islands and SLR have a greater influence on these tidal parameters within the estuary. However, maximum tidal

  18. Quantifying the uncertainty in site amplification modeling and its effects on site-specific seismic-hazard estimation in the upper Mississippi embayment and adjacent areas

    USGS Publications Warehouse

    Cramer, C.H.

    2006-01-01

    The Mississippi embayment, located in the central United States, and its thick deposits of sediments (over 1 km in places) have a large effect on earthquake ground motions. Several previous studies have addressed how these thick sediments might modify probabilistic seismic-hazard maps. The high seismic hazard associated with the New Madrid seismic zone makes it particularly important to quantify the uncertainty in modeling site amplification to better represent earthquake hazard in seismic-hazard maps. The methodology of the Memphis urban seismic-hazard-mapping project (Cramer et al., 2004) is combined with the reference profile approach of Toro and Silva (2001) to better estimate seismic hazard in the Mississippi embayment. Improvements over previous approaches include using the 2002 national seismic-hazard model, fully probabilistic hazard calculations, calibration of site amplification with improved nonlinear soil-response estimates, and estimates of uncertainty. Comparisons are made with the results of several previous studies, and estimates of uncertainty inherent in site-amplification modeling for the upper Mississippi embayment are developed. I present new seismic-hazard maps for the upper Mississippi embayment with the effects of site geology incorporating these uncertainties.

  19. Paleoseismic evidence for dynamic surface rupturing in an intraplate setting (Lower Rhine Embayment, central Europe)

    NASA Astrophysics Data System (ADS)

    Kuebler, S.; Friedrich, A. M.; Strecker, M. R.

    2011-12-01

    One of the most enigmatic problems in intraplate earthquake geology is the spatio-temporal recurrence pattern of large earthquakes. Intraplate regions such as the New Madrid seismic zone or the central European rift system are subject to considerable seismic hazards, because fault activity is highly disparate in space and time and our knowledge about the recurrence of large earthquakes is still rudimentary. The current debate in central Europe ranges from slip dominated by repeated large coseismic events to slip dominated by aseismic creep. Here, field evidence in support of the former is sparse, and hence, some authors concluded that many faults move by slow aseismic creep rather than by ground rupturing earthquakes. We report new results from a paleoseismic study carried out in the Lower Rhine Embayment across a subsidiary normal fault in the area of Germany's largest historical earthquake (1756 AD, ML 6.2±0.2) that clearly revealed field evidence of dynamic surface faulting. At the trench site, the fault is covered by <5 m-thick Holocene fluvial gravel and flood deposits overlaying Devonian shale. We mapped a surface offset of ~1 m and a ~10 m wide zone of localized deformation expressed by abundant fractures with aligned and broken clasts extending vertically throughout the entire gravel. Mapping of 237 fractured clasts and the long-axis orientation of ~10.000 clasts defines a deformation zone coinciding with the surface offset and two offset markers within the gravel layers. We interpret these features as the result of coseismic deformation at the near-surface end of the rupture. We rule out alternative processes which may lead to fracturing of pebbles such as freeze-thaw weathering or sediment loading effects, since both the gravel fabric and fracture planes coincide well with the fault orientation. We preclude slow deformation due to aseismic creep as governing process to cause rupturing of pebbles this close to the surface, as this would require an

  20. GRAND DITCH VIEW, FROM FARVIEW CURVE OVERLOOK, VIEWING WEST. DITCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GRAND DITCH VIEW, FROM FARVIEW CURVE OVERLOOK, VIEWING WEST. DITCH IS INDICATED BY HORIZONTAL LINE NEAR TOP OF CLOUD COVERED PEAKS - Grand Ditch, Baker Creek to LaPoudre Pass Creek, Grand Lake, Grand County, CO

  1. View of upstream face of Grand Coulee Dam, looking northeast. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of Grand Coulee Dam, looking northeast. This image features a cloudless sky.) - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  2. Crustal structure of the Amundsen Sea Embayment, West Antarctica: Implications for its tectonic evolution from a geophysical dataset.

    NASA Astrophysics Data System (ADS)

    Kalberg, Thomas; Gohl, Karsten

    2013-04-01

    The Amundsen Sea Embayment of West Antarctica is a centrepiece in understanding the history of the New Zealand - Antarctica breakup. This region plays a key role in plate kinematic reconstruction of the southern Pacific from the collision of the Hikurangi Plateau with the Gondwana subduction margin to the evolution of the West Antarctic Rift System. During two RV Polarstern cruises in 2006 and 2010, a large geophysical dataset was collected consisting of seismic refraction and reflection profiles, shipborne gravity and helicopter magnetic measurements. The data provide constraints on the crustal architecture, the structural evolution and the tectonic block formation during and after the Cretaceous continental breakup. We present two continental rise-to-shelf P-wave velocity models which were derived from forward travel-time modelling of ocean bottom hydrophone recordings which provide an insight into the crustal and upper mantle architecture beneath the Amundsen Sea Embayment for the first time. The sedimentary sequences and the basement were constrained by seismic reflection data. A 2-D density-depth model supports and complements the P-wave modelling. Observed P-wave velocities show 10 to 14 km thick crust of the continental rise and up to 28 km thick crust beneath the middle and inner shelf. The crust of the continental rise is characterized by a small gradient in thickness. Including horst and graben structures this can be associated with wide-mode rifting. A high velocity zone with velocities ranging between 7.1 and 7.6 km/s indicate magmatic underplating of variable thickness along the entire transect. We classify this margin as one of volcanic type rather than magma poor because of the high-velocity zone and seaward dipping reflectors observed from the seismic reflection data. We discuss the possibility of a serpentinized upper mantle caused by seawater penetration at the Marie Byrd Seamounts. The crustal structure, distinct zones in potential field

  3. A large CO2 sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)

    NASA Astrophysics Data System (ADS)

    Cotovicz, L. C., Jr.; Knoppers, B. A.; Brandini, N.; Costa Santos, S. J.; Abril, G.

    2015-03-01

    In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land-ocean interface are still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, SE-Brazil. Water pCO2 varied between 22 and 3715 ppmv in the Bay showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and Chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10% of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. In the inner part of the bay, the calculated annual CO2 sink (-19.6 mol C m2 yr-1) matched the organic carbon burial in the sediments reported in the literature. The carbon sink and autotrophy of Guanabara Bay was driven by planktonic primary production promoted by eutrophication, and by its typology of marine embayment lacking the classical extended estuarine mixing zone, in contrast to river-dominated estuarine systems, which are generally net heterotrophic and CO2 emitters. Our results show that global CO2

  4. Texas-louisiana shelf circulation and transport processes study: Year 2, annual report. Final report, April 1993-March 1994

    SciTech Connect

    Jochens, A.E.; Nowlin, W.D.

    1995-05-01

    The Minerals Management Service (MMS) of the Department of the Interior supports the Louisiana-Texas Shelf Physical Oceanography Program (LATEX). LATEX is divided into three study units: Study Unit A, Texas-Louisiana Shelf Circulation and Transport Process (LATEX A or LATEX Shelf); Study Unit B, Mississippi River Plume Hydrography (LATEX B or LATEX Plume); and Study Unit C, Gulf of Mexico Eddy Circulation (LATEX C or LATEX Eddy). LATEX A, the largest of the three studies, covers the middle and outer Texas-Louisiana continental shelf from the Mississippi River to the Rio Grande. The report focuses on the work of LATEX A during the second field year, April 1993 through March 1994.

  5. Regional distribution of wave- and fluvial-dominated deltaic deposits of Olmos formation (upper Cretaceous) in Maverick basin, southwest Texas

    SciTech Connect

    Ambrose, W.; Tyler, N.

    1984-04-01

    Regional subsurface analysis in southwest Texas indicates that the Olmos Formation (Gulfian) was deposited by a complex of wave- and fluvial-dominated delta systems in two depocenters. Sediment influx was from the north and northwest. Five deltaic submits, A through E, were deposited in the western depocenter. Three other deltaic wedges (F, G, H) formed the second depocenter farther east in present-day Frio and LaSalle Counties. Subsidence was greater in the western half of the Maverick basin where thickest (1,300 ft; 395 m) deltaic sediments were deposited. Lower Olmos strata represent a succession from wave-reworked, strike-elongate deltas of subunit A, similar to those of the underlying San Miguel Formation, to fluvial-dominated, dip-elongate deltas of subunits B and C. Extensive (1200 mi/sup 2/ or 3100 km/sup 2/ in Texas) aggradational floodplain deposits of B and C are characterized by diverse electric-log patterns; variation in log character is a response to complex depositional facies on the delta platform. Downdip, toward the Cretaceous shelf edge, delta-plain facies merge with upward-coarsening delta-front sandstones. Uppermost subunits D and E were deposited by a prograding barrier-island system in an interdeltaic embayment marginal to high constructive deltas of the easter depocenter. Lagoonal and fluvial-channel deposits are recognized from cores. Eastward migration of deposition was accompanied by an abrupt change of depositional style in the western depocenter from deltaic to coastal-interdeltaic.

  6. 75 FR 45611 - Texas Eastern Transmission LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... Energy Regulatory Commission Texas Eastern Transmission LP; Notice of Application July 27, 2010. Take notice that on July 15, 2010, Texas Eastern Transmission (Texas Eastern), P.O. Box 1642, Houston, Texas... Eastern Transmission, LP, P.O. Box 1642, Houston, Texas 77251-1642, or by calling (713)...

  7. 76 FR 38381 - Texas Eastern Transmission, LP; Notice of Amendment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Amendment Take notice that on June 13, 2011, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas 77056... Application should be directed to Berk Donaldson, Director, Rates and Certificates, Texas Eastern...

  8. 77 FR 20015 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on March 19, 2012, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas.... Connolly, General Manager, Rates & Certificates, Texas Eastern Transmission, LP, P.O. Box 1642,...

  9. 78 FR 26340 - Texas Gas Transmission, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... Energy Regulatory Commission Texas Gas Transmission, LLC; Notice of Application Take notice that on April 15, 2013, Texas Gas Transmission, LLC (Texas Gas), 9 Greenway Plaza, Suite 2800, Houston, Texas 77046..., Rates and Regulatory Affairs, Texas Gas Transmission, LLC, 9 Greenway Plaza, Suite 2800, Houston,...

  10. 76 FR 49760 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on July 29, 2011, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas... directed to Lisa A. Connolly, General Manager, Rates & Certificates, Texas Eastern Transmission, LP,...

  11. 77 FR 26534 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on April 19, 2012, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas... directed to Marcy F. Collins, Associate General Counsel, Texas Eastern Transmission, LP, P.O. Box...

  12. Water resources simulation in the Rio Grande basin using coupled models

    SciTech Connect

    Springer, E.P.; Winter, C.L.; Bossert, J.E.

    1999-04-01

    Regional assessments of water resources under global climate change require models that can resolve management, land use, and climate effects. Los Alamos National Laboratory is developing a coupled model of water resources that places a river basin in its global context. The upper Rio Grande basin above El Paso, Texas is the testbed for this model. The model structure and computational approach are emphasize and issues such as nonlinear feedback between components and spatial and temporal scaling of processes are discussed. Using simulations of regional meteorology, the effects of high spatial resolution simulations on the distribution of precipitation are demonstrated.

  13. Late Holocene shoreline behavior in embayments of Lake Michigan: Influence of quasi-periodic lake-level variations and sediment supply

    SciTech Connect

    Thompson, T.A.; Baedke, S.J. . Indiana Geological Survey)

    1994-04-01

    Lake Michigan contains numerous former embayments into glacial deposits or bedrock. Many of the embayments contain dunes, spits, and captured lakes, but others contain arcuate strandplains of beach ridges. The strandplains are a geologic record of shoreline behavior and lake-level variation throughout the late Holocene. The larger strandplains show similar long-term patterns of beach-ridge development. The similar patterns are expected because variations in lake level are a primary control on shoreline behavior, and all embayments would have experienced relatively the same lake-level changes. Some variations in the long-term pattern of shoreline development do occur between strandplains. These dissimilarities are primarily a function of different rates of sediment supply to the shoreline of each embayment. Beach-ridge development within embayments can be represented on a rate of water level change versus rate of sediment supply diagram (Curray diagram) as three superimposed ovals on the positive rate of sediment supply side of the diagram. The three stacked ovals represent the three quasi-periodic lake-level variations defined by Thompson (1992) and show the position of the shoreline for a given time within the Curray diagram fields. For shorelines with a high rate of sediment supply, only the 30-year quasi-periodic variation would reach the aggradation line. For shorelines having significantly less sediment supply, rising lake level on the 150- and 600-year variations would force the 30-year oval across the aggradation line and well into the depositional and possibly the erosional transgression fields. Under these conditions erosion would occur that may remove, stack, or at least prevent one or more beach ridges from being developed.

  14. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  15. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the Turning... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety...

  16. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the Turning... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety...

  17. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the Turning... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety...

  18. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the Turning... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety...

  19. Bedrock platforms within the Ross Embayment, West Antarctica: Hypotheses for ice sheet history, wave erosion, Cenozoic extension, and thermal subsidence

    NASA Astrophysics Data System (ADS)

    Wilson, Douglas S.; Luyendyk, Bruce P.

    2006-12-01

    Ice-penetrating radar (mostly airborne) and marine seismic surveys have revealed plateaus and terraces about 100-350 m below sea level beneath parts of the Ross Embayment, including the West Antarctic ice sheet, the Ross Ice Shelf, and the eastern Ross Sea. These surfaces cover many thousands of square kilometers and are separated by bedrock troughs occupied by the West Antarctic ice streams. Prominent plateaus are under Edward VII Peninsula, Siple Dome, and Roosevelt Island. Marine seismic data and gravity data over the buried plateaus support an interpretation that they were caused by erosion into basement. The flat and level nature of the surfaces that were formed by erosion, are near the same depth over large distances, and fringe the buried rugged bedrock topography of Marie Byrd Land supports an interpretation of marine rather than glacial erosion. Marine seismic reflection profiles over one of the plateau remnants show it as an angular unconformity cut into gently dipping sediments of late Oligocene age, draped with thin, flat-lying sediments, implying that the plateau is early Miocene or younger. The younger limit for plateau erosion follows from the interpretation of the mechanism: erosion must predate permanent ice along the coast associated with the growth of the West Antarctic ice sheet, probably prior to 10 Ma and possibly prior to 14 Ma. The plateaus along the Siple Coast, with depths around 350 meters, do not rebound to close to sea level and wave base for models of removing past and present ice load. This discrepancy can be explained if Ross Embayment lithosphere has been cooling and subsiding since significant extension in Eocene to Oligocene time. Our interpretation requires crustal subsidence in the Ross Sea, which in turn implies higher bedrock elevations in the past within this region. Higher-standing topography presented an opportunity for the accumulation of local ice sheets and caused sea level fluctuation prior to late Cenozoic time.

  20. Wildlife, urban inputs, and landscape configuration are responsible for degraded swimming water quality at an embayed beach

    USGS Publications Warehouse

    Byappanahalli, Muruleedhara N.; Nevers, Meredith; Whitman, Richard L.; Ge, Zhongfu; Shively, Dawn A.; Spoljaric, Ashley; Przybyla-Kelly, Katarzyna

    2015-01-01

    Jeorse Park Beach, on southern Lake Michigan, experiences frequent closures due to high Escherichia coli (E. coli) levels since regular monitoring was implemented in 2005. During the summer of 2010, contaminant source tracking techniques, such as the conventional microbial and physical surveys and hydrodynamic models, were used to determine the reasons for poor water quality at Jeorse Park. Fecal indicator bacteria (E. coli, enterococci) were high throughout the season, with densities ranging from 12–2419 (culturable E. coli) and 1–2550 and < 1–5831 (culturable and qPCR enterococci, respectively). Genetic markers for human (Bacteroides HF183) and gull (Catellicoccus marimammalium) fecal contamination were found in 15% and 37% of the samples indicating multiple sources contributing to poor water quality. Nesting colonies of double-crested cormorants (Phalacrocorax auritus) have steadily increased since 2005, coinciding with high E. colilevels. A hydrodynamic model indicated that limited circulation allows bacteria entering the embayed area to be retained in nearshore areas; and bacterial resuspension from sand and stranded beach wrack during storm events compounds the problem. The integration of hydrodynamics, expanded use of chemical and biological markers, as well as more complex statistical multivariate techniques can improve microbial source tracking, informing management actions to improve recreational water quality. Alterations to embayed structures to improve circulation and reduce nuisance algae as well as growing native plants to retain sand to improve beach morphometry are among some of the restoration strategies under consideration in ongoing multi-agency collaborations.

  1. Influence of the West Antarctic Ice Sheet and its collapse on the wind and precipitation regimes of the Ross Embayment

    NASA Astrophysics Data System (ADS)

    Seles, D.; Kowalewski, D. E.

    2015-12-01

    Marine Isotope Stage 31 (MIS 31) is a key analogue for current warming trends yet the extent of the East Antarctic Ice Sheet (EAIS) and the West Antarctic Ice Sheet (WAIS) during this interglacial remains unresolved. Inconsistencies persist between offshore records (suggesting the instability of WAIS) and McMurdo Dry Valley (MDV) terrestrial datasets (indicating long-term ice sheet stability). Here we use a high-resolution regional scale climate model (RegCM3_Polar) to reconstruct paleoclimate during MIS 31 (warm orbit, 400 ppm CO2) and assess changes in precipitation and winds (including katabatic) with WAIS present versus WAIS absent. The MIS 31 scenario with WAIS present resulted in minimal changes in wind magnitude compared with current climate conditions. With WAIS absent, the model predicts a decrease in coastal and highland monthly mean average wind velocities. The greatest rates of snowfall remain along the coast but shift towards higher latitudes with the interior continent remaining dry when WAIS is removed. Focusing on the Ross Embayment, this decreased monthly mean wind velocity and shift of winds to the east indicate a greater influence of offshore winds from the Ross Sea, enabling the increase of precipitation southward along the Transantarctic Mountains (TAM) (i.e. MDV). The apparent decrease of katabatic winds with no WAIS implies that offshore winds may be responsible for bringing the warmer, wetter air into the TAM. The change in wind and precipitation in the Ross Embayment and specifically the MDV highlights the impact of WAIS on Antarctic climate and its subsequent influence on the mass balance of peripheral EAIS domes (i.e. Taylor Dome). Modeling suggests that if WAIS was absent during MIS 31, we would expect (1) greater accumulation at such domes and (2) MDV terrestrial records that reflect a wetter climate, and (3) weaker winds suggesting possibly lower ablation/erosion rates compared to if WAIS was present.

  2. Toxicity of waters from the Rochester Embayment Area of Concern to the plankton species Pseudokirchneriella subcapitata and Ceriodaphnia dubia

    USGS Publications Warehouse

    Baldigo, Barry P.; Duffy, Brian T.; Smith, Alexander J; George, Scott D.

    2016-01-01

    The lower Genesee River and Rochester Embayment of Lake Ontario are a designated Area of Concern (AOC) under the binational Great Lakes Water Quality Agreement. The “degradation of phytoplankton and zooplankton populations” or plankton Beneficial Use Impairment (BUI) was classified as unknown and in need of further assessment in this AOC because water quality data suggested plankton communities could be effected and community data were either unavailable or indicated impacts. The plankton BUI may now be obsolete because local contaminant sources have been largely eliminated. The present study was conducted between July 2013 and August 2014 to assess the BUI-removal criteria: “AOC plankton bioassays confirm that toxicity in ambient waters (i.e., no growth inhibition) is not significantly higher than comparable non-AOC controls”. Acute and chronic toxicity of waters from 13 sites were quantified seasonally using standardized bioassays with the green alga Pseudokirchneriella subcapitata and water flea Ceriodaphnia dubia to test the hypothesis that toxicity of waters from AOC sites was not higher than that of waters from comparable non-AOC reference sites. Survival and reproduction of C. dubia did not differ significantly between site types, systems, or months. The growth of P. subcapitata did not differ between site types, but differed among systems and months. All results indicate that waters from AOC sites were no more toxic to both plankton species than waters from reference sites. Assuming test species represent natural plankton assemblages, water quality should not negatively affect survival and growth of resident plankton populations in the Rochester Embayment AOC.

  3. Freshwater withdrawals in Texas, 1985

    USGS Publications Warehouse

    Lurry, Dee L.; Barber, Nancy L.

    1990-01-01

    Since 1950, the U.S. Geological Survey (USGS) has estimated water use in the United States at 5-year intervals.  Resulting reports tabulate water use by State and by water-resources region (major river basins) for a number of categories, such as irrigation, water supply, and industrial.  In 1977, the USGS began the National Water-Use Information Program, designed to be a National source of accurate, consistent water-use data.  The water-use project in Texas is part of the National Water-Use Information Program.  The Texas District of the USGS compiles water-use information by county and by hydrologic unit using data collected by States agencies.  A hydrologic unit is a geographic area representing part or all of a surface drainage basin, a combination of drainage basins, or a distinct hydrologic feature.

  4. Hydrogeologic assessment of shallow flow systems in the Walnut Formation, central Texas

    SciTech Connect

    Feckley, D.L. . Geology Dept.)

    1993-02-01

    The Walnut Formation crops out in the limestone dominated terrain of the Grand Prairie in Central Texas. The Walnut is the only clay-rich member within this dominantly limestone section. Because of its clay-rich nature, agricultural landuse of the Walnut Formation is greater than on surrounding formations. The clay content also makes the Walnut a natural consideration for waste disposal sites. However, many drainages and streams receive baseflow from the Walnut, and the Walnut overlies the Paluxy Aquifer, a minor aquifer in the State of Texas. Therefore, understanding the hydrogeology of the Walnut becomes increasingly important in order to protect baseflow water quality, and the underlying Paluxy Aquifer. Evaluation of hydrogeologic properties includes well hydrograph analysis, slug tests, pumping tests and laboratory tests. Results strongly indicate the presence of shallow flow systems, which are influenced by geomorphology and stratigraphy. An understanding of the geomorphic evolution of the region greatly aids the groundwater investigations.

  5. FOUR NOTCH ROADLESS AREA, TEXAS.

    USGS Publications Warehouse

    Houser, B.B.; Ryan, George S.

    1984-01-01

    A geologic and geochemical investigation of the Four Notch Roadless Area, Texas, was conducted. The area has a probable resource potential for oil and gas. There is, however, little promise for the occurrence of metallic mineral resources or other energy resources. Acquisition of seismic data and detailed comparisons with logs from wells from the vicinity of the Four Notch Roadless Area is necessary to better determine if the subsurface stratigraphy and structures are favorable for the accumulation of oil or gas.

  6. Guadalupian studies in West Texas

    USGS Publications Warehouse

    Grant, R.E.; Wardlaw, B.R.; Rohr, D.M.

    2000-01-01

    Murchison established the Permian System in the Ural Mountains of Russia in 1841. The first North American Permian fossils were discovered by Hall (1856) about 15 years later. The fossils, which were collected in New York State, were initially described as Carboniferous (Hall, 1856) but were subsequently recognized as Permian by Girty (1902). Benjamin F. Shumard (1858), however, was the first to place an unequivocal Permian designation on some North American fossils, which has been collected by his brother George G. Shumard from the Guadalupe Mountains in Texas. A half a century passed before Girty (1908) made known an extensive Guadalupian fauna, although his field work in Texas and his study of this fauna already lead him to propose a Guadalupian "period" (Girty, 1902). Girty's suggestion was accepted only when it was formalized as the Guadalupe Series by Adams et al. (1939). The "Guadalupian fauna" was based upon fossils that Girty collected in 1901 on an expedition headed by Robert T. Hill, a revered figure in Texas geology.

  7. Sediment Management Options for Galveston Island, Texas

    DTIC Science & Technology

    2015-06-15

    the potential for long-term sustainability are presented. Galveston Island is a 47 km long sand barrier island along the upper Texas coast (Figure...1 SEDIMENT MANAGEMENT OPTIONS FOR GALVESTON ISLAND , TEXAS ASHLEY E. FREY1, ANDREW MORANG1, DAVID B. KING1, ROBERT C. THOMAS2 1. U.S. Army...Galveston Island is a major tourist and commercial center on the Gulf of Mexico at the mouth of Galveston Bay, Texas, USA. The shoreline along the

  8. 27 CFR 9.136 - Texas Hill Country.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., 1954 (revised 1974); (2) Sonora, Texas, 1954 (revised 1978); (3) Llano, Texas, 1954 (revised 1975); (4....S. Highway 377 southwest to the town of Rocksprings, on the Sonora, Texas, U.S.G.S. map, where...

  9. The Texas Research Development Fund: Building Institutional Research Capacity at Texas Public Universities

    ERIC Educational Resources Information Center

    Rosales, Laura Leal

    2010-01-01

    In 2001, the Texas state legislature created the Texas Excellence Fund (TEF) and the University Research Fund (URF) with the purpose of supporting institutional excellence and research capacity at general academic institutions. During the 2002-2003 biennium, participating Texas public universities received revenues from these funds (Legislative…

  10. Spatial Relationships of Soil Texture and Crop Rotation to Aspergillus flavus Community Structure in South Texas.

    PubMed

    Jaime-Garcia, Ramon; Cotty, Peter J

    2006-06-01

    ABSTRACT Aspergillus flavus, the causal agent of aflatoxin contamination of cottonseed, is a natural inhabitant of soils. A. flavus can be divided into the S and L strains, of which the S-strain isolates, on average, produce greater quantities of aflatoxins than the L-strain isolates. Aflatoxin contamination can be severe in several crops in South Texas. The structure of A. flavus communities residing in soils of South Texas was determined from 326 soil samples collected from 152 fields located from the Rio Grande Valley in the south to Fort Bend County in the north from 2001 through 2003. Analysis of variance indicated significant differences in the incidence of A. flavus isolates belonging to the S strain (percent S) among regions. The Coastal Bend (30.7%) and Upper Coast (25.5%) regions had significantly higher percent S incidence than the Rio Grande Valley (4.8%). No significant differences in percent S among years were detected. The CFU per gram of soil were not significantly different among regions. Strain S incidence was positively correlated with clay content and negatively correlated with sand content. Fields cropped to cotton the previous year had a higher S-strain incidence, whereas fields cropped to corn had greater total quantities of A. flavus propagules. Maps of S-strain patterns show that the S strain constitutes >30% of the overall A. flavus community in the area extending from the central Coastal Bend region to the central Upper Coast region. The west Rio Grande Valley had the lowest S-strain incidence (<10%). Geographic variation in S-strain incidence may influence the distribution of aflatoxin contamination in South Texas.

  11. Grand Challenges of Enterprise Integration

    SciTech Connect

    Brosey, W.D; Neal, R.E.; Marks, D.

    2001-04-01

    Enterprise Integration connects and combines people, processes, systems, and technologies to ensure that the right people and the right processes have the right information and the right resources at the right time. A consensus roadmap for Technologies for Enterprise Integration was created as part of an industry/government/academia partnership in the Integrated Manufacturing Technology Initiative (IMTI). Two of the grand challenges identified by the roadmapping effort will be addressed here--Customer Responsive Enterprises and Totally Connected Enterprises. Each of these challenges is briefly discussed as to the current state of industry and the future vision as developed in the roadmap.

  12. Water quality, discharge, and groundwater levels in the Palomas, Mesilla, and Hueco Basins in New Mexico and Texas from below Caballo Reservoir, New Mexico, to Fort Quitman, Texas, 1889-2013

    USGS Publications Warehouse

    McKean, Sarah E.; Matherne, Anne Marie; Thomas, Nicole

    2014-01-01

    The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, compiled data from various sources to develop a dataset that can be used to conduct an assessment of the total dissolved solids in surface water and groundwater of the Palomas, Mesilla, and Hueco Basins in New Mexico and Texas, from below Caballo Reservoir, N. Mex., to Fort Quitman, Tex. Data include continuous surface-water discharge records at various locations on the Rio Grande; surface-water-quality data for the Rio Grande collected at selected locations in the Palomas, Mesilla, and Hueco Basins; groundwater levels and groundwater-quality data collected from selected wells in the Palomas and Mesilla Basins; and data from several seepage investigations conducted on the Rio Grande and selected drains in the Mesilla Basin.

  13. Prolific Overton field gas reservoirs within large transverse oolite shoals, Upper Jurassic Haynesville, Eastern Margin East Texas basin

    SciTech Connect

    Glynn, W.G.; Covington, T.E.; Lighty, R.G.; Ahr, W.M.

    1985-02-01

    Late Triassic rifting along a northeast-southwest spreading center in east Texas resulted in basement highs along the eastern margin of the East Texas basin that became sites of extensive ooid shoal deposition during Late Jurassic time. Reservoirs within oolite facies at Overton field contain over 1 tcf of natural gas. These large shoals, each approximately 15 mi (24 km) long and 3 mi (4.8 km) wide, trend north-south as a group and northeast-southwest individually. They are oblique to the basin margin but parallel with Jurassic diffracted tidal currents within the East Texas embayment. Modern Bahamian ooid shoals of similar size, trend, and depositional setting occur at the terminus of the deep Tongue-Of-The-Ocean platform reentrant. Overton field reservoirs are in ooid grainstone shoal facies and in transitional shoal margins of skeletal-oolitic-peloidal grainstones and packstones. Adjacent nonreservoir facies are peloidal-skeletal-siliciclastic wackestones and mudstones. Early diagenesis of grainstone reservoir facies included meteoric dissolution and grain stabilization, resulting in abundant chalky intraparticle porosity and equant and bladed calcite cements filling interparticle porosity. Subsequent burial diagenesis resulted in intense solution compaction and coarse equant calcite and saddle crystal dolomite that occluded remaining interparticle porosity. Whole-rock trace element analysis indicates greatest diagenetic flushing (less magnesium, strontium) in porous zones. Stable isotopes for grains and cements show strong overprint of later burial diagenesis, with greater depletion of delta/sup 18/O in reservoir facies. However, hydrocarbons were emplaced prior to late cementation, and unlike other Jurassic Gulf Coast reservoirs, deep burial diagenesis provided no late-stage formation of porosity.

  14. Ground-water flow paths and traveltime to three small embayments within the Peconic Estuary, eastern Suffolk County, New York

    USGS Publications Warehouse

    Schubert, Christopher E.

    1999-01-01

    The Peconic Estuary, at the eastern end of Long Island, has been plagued by a recurrent algal bloom that has caused the severe decline of local marine resources. Although the onset, duration, and cessation of the bloom remain unpredictable, ground-water discharge has been shown to affect surface-water quality in the western part of the estuary. Results from a study on the North Fork of Long Island indicate that local hydrogeologic factors cause differences in ground-water age and characteristics of discharge to the estuary. The need for information on the local patterns and rates of ground-water discharge to the Peconic Estuary prompted analysis of ground-water flow paths and traveltime to three small embayments within the estuary.Meetinghouse Creek, near the west end of the North Fork; Sag Harbor Cove, in the central part of the South Fork; and West Neck Bay, on Shelter Island.Ground-water-flow models were developed, and particle-tracking procedures were applied to the results of each model, to define the flow paths and traveltime of ground water to the three embayments. The steady-state flow models represent the two-dimensional ground-water-flow system along a vertical section through the uplands of each embayment and simulate long-term hydrologic conditions. The particle-tracking procedure used model-generated ground-water levels and flow rates to calculate the water-particle pathlines and times-of-travel through each flow system from the point of entry (recharge) to the point of exit at streams, the shore, or subsea-discharge areas.Results for the Meetinghouse Creek study area indicate that about 50 percent of the total recharge that enters the system flows southward to Meetinghouse Creek; half of this amount discharges as base flow to the fresh-water reach of the creek, and half as shoreline underflow to the estuarine reach. About 85 percent of the total discharge to Meetinghouse Creek has flowed entirely within the upper glacial aquifer, and about 15 percent

  15. Ground-water flow paths and traveltime to three small embayments within the Peconic Estuary, eastern Suffolk County, New York

    USGS Publications Warehouse

    Schubert, Christopher E.

    1999-01-01

    The Peconic Estuary, at the eastern end of Long Island, has been plagued by a recurrent algal bloom that has caused the severe decline of local marine resources. Although the onset, duration, and cessation of the bloom remain unpredictable, ground-water discharge has been shown to affect surface-water quality in the western part of the estuary. Results from a study on the North Fork of Long Island indicate that local hydrogeologic factors cause differences in ground-water age and characteristics of discharge to the estuary. The need for information on the local patterns and rates of ground-water discharge to the Peconic Estuary prompted analysis of ground-water flow paths and traveltime to three small embayments within the estuary.Meetinghouse Creek, near the west end of the North Fork; Sag Harbor Cove, in the central part of the South Fork; and West Neck Bay, on Shelter Island. Ground-water-flow models were developed, and particle-tracking procedures were applied to the results of each model, to define the flow paths and traveltime of ground water to the three embayments. The steady-state flow models represent the two-dimensional ground-water-flow system along a vertical section through the uplands of each embayment and simulate long-term hydrologic conditions. The particle-tracking procedure used model-generated ground-water levels and flow rates to calculate the water-particle pathlines and times-of-travel through each flow system from the point of entry (recharge) to the point of exit at streams, the shore, or subsea-discharge areas. Results for the Meetinghouse Creek study area indicate that about 50 percent of the total recharge that enters the system flows southward to Meetinghouse Creek; half of this amount discharges as base flow to the fresh-water reach of the creek, and half as shoreline underflow to the estuarine reach. About 85 percent of the total discharge to Meetinghouse Creek has flowed entirely within the upper glacial aquifer, and about 15

  16. An Analysis of Laboratory Safety in Texas.

    ERIC Educational Resources Information Center

    Fuller, Edward J.; Picucci, Ali Callicoatte; Collins, James W.; Swann, Philip

    This paper reports on a survey to discover the types of laboratory accidents that occur in Texas public schools, the factors associated with such accidents, and the practices of schools with regard to current laboratory safety requirements. The purpose of the survey is to better understand safety conditions in Texas public schools and to help…

  17. Introduction to Basic Texas State Documents Reference.

    ERIC Educational Resources Information Center

    Walton, Robert

    The Texas State Publications Clearinghouse of the Texas State Library has prepared this list of materials pertaining to legislative and executive branch publications on the state and local level. Judicial branch publications are judged innappropriate as they are best left in the domain of the law library. The specific topics are…

  18. 40 CFR 81.429 - Texas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Texas. 81.429 Section 81.429 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF... Visibility Is an Important Value § 81.429 Texas. Area name Acreage Public Law establishing Federal...

  19. TEXAS MIGRANT LABOR, THE 1965 MIGRATION.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    THE CALENDAR YEAR 1965 WAS THE FIRST FULL YEAR IN WHICH NO BRACEROS WERE IMPORTED FROM MEXICO. CROP LOSSES OCCURRED IN SOME AREAS OF THE COUNTRY DUE TO LABOR SHORTAGES, HOWEVER, GOVERNMENT OFFICIALS STATE THAT THESE SHORTAGES CAN BE AVOIDED IN THE FUTURE. THE MAJORITY OF TEXAS MIGRANTS LIVE IN SOUTH TEXAS AND APPROXIMATELY 95 PERCENT OF THEM ARE…

  20. Texas Migrant Labor. 1975 Annual Report.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    The Good Neighbor Commission of Texas coordinates the work of the Federal, State, and local government toward the improvement of travel and living and working conditions of Texas migrant laborers and their families. Covering the full spectrum of migrant labor activity directly related to the improvement of the well-being of migrant and seasonal…

  1. Texas Migrant Labor, 1974 Annual Report.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    Organized under a 1943 Federal grant and later funded by legislative appropriations, the Good Neighbor Commission of Texas coordinates the work of Federal, State, and local government units endeavoring to improve the travel, living, and working conditions of Texas migrant farmworkers and their families. The 1974 annual report chronicles the facts,…

  2. Texas Migrant Labor. Annual Report, 1971.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    The Good Neighbor Commission of Texas, organized under a Federal grant in 1943 and later constituted as an agency of state government by legislative mandate, is charged under its basic law to coordinate the work of the Federal, State, and local government units endeavoring to improve the travel and working conditions of Texas migrant farm workers.…

  3. TEXAS MIGRANT LABOR, THE 1966 MIGRATION.

    ERIC Educational Resources Information Center

    Good Neighbor Commission of Texas, Austin.

    THE CALENDAR YEAR 1966 WAS THE SECOND FULL YEAR IN WHICH NO BRACEROS WERE IMPORTED FROM MEXICO. CRITICAL LABOR SHORTAGES OCCURRED IN SOME AREAS, HOWEVER, THE DOMESTIC LABOR SUPPLY BECAME MORE STABLE AND FEWER PROBLEMS WERE EXPERIENCED THAN IN 1965. THE MAJORITY OF TEXAS MIGRANTS LIVE IN SOUTH TEXAS AND APPROXIMATELY 95 PERCENT OF THEM ARE OF…

  4. Northeast Texas Workplace Partnership Implementation Program.

    ERIC Educational Resources Information Center

    Northeast Texas Community Coll., Mount Pleasant.

    The Northeast Texas Workplace Partnership Program developed curriculum and training materials based on the literacy requirements of the workplace for two different industries in northeast Texas--Lone Star Steel Company and Pilgrim's Pride Industries. Three advisory committees were established to involve the community, education, and business and…

  5. 21 CFR 808.93 - Texas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific State and Local Exemptions § 808.93 Texas. (a) The following Texas medical device requirement is...

  6. 21 CFR 808.93 - Texas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific State and Local Exemptions § 808.93 Texas. (a) The following Texas medical device requirement is...

  7. Research, Publishing, and Tenure among Texas Biologists

    ERIC Educational Resources Information Center

    Salehi, Faiz

    2007-01-01

    This study examined opinions toward research among biology faculty in Texas institutions of higher learning. The objectives of the study were to determine what the viewpoints of Texas biology faculty were toward research according to faculty rank and institutional type. Mailed questionnaire approach was used in this study to collect data.…

  8. 76 FR 40765 - Texas Disaster #TX-00378

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ... ADMINISTRATION Texas Disaster TX-00378 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Texas dated 07/05/2011. Incident: Dyer Mills Fire. Incident Period: 06/19/2011 through 06/26/2011. Effective Date:...

  9. Texas School Law: A Practical Guide.

    ERIC Educational Resources Information Center

    Frels, Kelly, Ed.; Horner, Jeff, Ed.; Camp, Bill, Ed.; Robinson, Vianei Lopez, Ed.

    Intended as a practical legal guide for Texas educators and lawyers, this book contains three major sections dealing with several chapters on various school law topics, each prepared by Texas attorneys. Section 1, "School Boards and Superintendents," includes chapters on school board members authority and relationship with staff, the…

  10. Texas Migrant Council, Inc. Siempre Unidos.

    ERIC Educational Resources Information Center

    Texas Migrant Council, Inc., Laredo.

    In 1969 the Texas Migrant Council Mobile Head Start began a program of year-round day care/head start services that would follow migrant children from their South Texas winter home to certain northern states during the summer. Services included educational, medical and nutritional help. Prime grantee for the project was initially the Colorado…

  11. Texas Almanac Teacher's Guide, 1998-99.

    ERIC Educational Resources Information Center

    Dallas Morning News, TX.

    This teacher's guide utilizes the subject matter in the 1998-99 Texas Almanac in a variety of interdisciplinary student activities for grades 3-8. The guide includes a grade-by-grade curriculum chart detailing which lessons correspond to specific Texas Assessment of Academic Skills (TAAS) objectives and Essential Element requirements. The 45…

  12. Texas Teacher Recruitment and Retention Study.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This report on teacher recruitment and retention in Texas identifies and analyzes programs offered by higher education institutions, school districts, regional education service centers, and other organizations that address the teacher shortage in Texas. The study was undertaken with the understanding that teacher compensation issues are pervasive…

  13. Texas Almanac Teacher's Guide, 2002-2003.

    ERIC Educational Resources Information Center

    Barringer, Betty; Ferguson, Sharon; Haynes, Beverly; Jacobs, Margaret; Jameson, Eugenia E.; Massey, Linda; Moran, Rebecca; Wilson, Ann

    This interdisciplinary guide utilizes the subject matter in the 2002-2003 "Texas Almanac" to help classroom educators teach students in grades three to eight about the social, economic, cultural, and historical background of Texas. The guide has questions, puzzles, and activities that teachers can use to inform their students about the…

  14. The Texas Head Start Metro Models.

    ERIC Educational Resources Information Center

    Riley, Mary Tom, Ed.; Flores, Alfredo R., Ed.

    The Texas Metro Network (TMN) is an informal group of Head Start Directors and Executive Directors organized for the purposes of improving the delivery of training and technical assistance and for assisting communication between large scale Head Start programs in the metropolitan areas of Texas. In pursuit of these aims, each member unit of the…

  15. Texas School Finance Reform: An IDRA Perspective.

    ERIC Educational Resources Information Center

    Cardenas, Jose A.

    This book chronicles the history of school finance reform in Texas between 1968 and 1995. Specifically, the book focuses on the substantial changes in the method of funding Texas public schools, aimed at creating a more equitable system of educational opportunity. The author, Dr. Jose A. Cardenas, founded the Intercultural Development Research…

  16. The Legacy of the Texas Tower Sniper

    ERIC Educational Resources Information Center

    Lavergne, Gary

    2007-01-01

    In this article, the author relates the incident that happened at the University of Texas to the tragedy that took place at Virginia Tech. On August 1, 1966, Charles Joseph Whitman ascended the University of Texas Tower, in Austin, and in 96 minutes fired 150 high-powered rounds of ammunition down upon an unsuspecting university family. The…

  17. 77 FR 25949 - Texas Regulatory Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-02

    ... Reclamation Division, Railroad Commission of Texas, 1701 North Congress Avenue, Capitol Station, P.O. Box... Identification of Interest and Compliance Information (Underground Mining) Texas proposes to add language to this...: Standards for Success (Surface Mining) and Sec. 12.560 Revegetation: Standards for Success...

  18. Child Care in Texas: A Report.

    ERIC Educational Resources Information Center

    Larson, Erik

    This report examines a basic child care challenge confronting the state of Texas: the shortage of affordable, accessible, quality early care and education for Texas families with children, particularly those with limited incomes. The report notes that these three factors--affordability, accessibility, and good quality--are integral to a successful…

  19. [Sybil Scott and East Texas Baseball Players.

    ERIC Educational Resources Information Center

    Woodfin, Samantha, Ed.

    1996-01-01

    This issue of "Loblolly Magazine" is dedicated to Sybil Scott, born in 1910 and still going at the age of 85. She shares some interesting tales of what it was like growing up in the '10's and '20's in Texas, including her school years. She remembers, very vividly, her childhood and teenage years in East Texas. Among the many interesting…

  20. Texas: The State and Its Educational System.

    ERIC Educational Resources Information Center

    Hodgkinson, Harold L.

    The more diversified the economy, the greater Texas's possibilities for security and stability. The state cannot diversify the job and business structure unless there is an educational system prepared to develop Texas's human resources to their fullest. The state's population will be over 40 percent minority by the end of the century, and student…

  1. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [Rio Grande Valley, Texas

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1979-01-01

    The author has identified the following significant results. Procedures to edit cloud-contaminated pixels from those pixels representing Earth surface features were investigated. Because clouds are more reflective than Earth features and are colder than Earth surface features most of the year at 26 N latitude, either a raw digital count ratio or a ratio of reflectance percentage for the VIS band to the temperature works well. For this procedure, the two bands of data need to be registered to the ground scene.

  2. Effectiveness of transgenic Bt cottons against noctuids in the Lower Rio Grande Valley of Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluations of the comparative efficacy of Bacillus thuringiensis Bollgard, Bollgard II and non-Bt traits expressing cottons for control of the noctuid complex composed of bollworms, Helicoverpa zea (Boddie), fall armyworms, Spodoptera frugiperda (J.E. Smith), beet armyworms, Spodoptera exigua (Hübn...

  3. Creating a Standardized Watersheds Database for the Lower Rio Grande/Rio Bravo, Texas

    DTIC Science & Technology

    2000-01-01

    inspected to verify vertical integration with the most recent (1995–96) digital orthoimagery source material. Differences were observed between features in...the orthoimagery and in the existing DLG hydrography lines. In some cases, DLG features were not present at all in the orthoimagery , or the DLG...hydrography lines were shifted as far as 75 meters from observed features in the orthoimagery . Furthermore, hydrography was shifted by varying amounts

  4. Ground-water resources of the lower Rio Grande Valley area, Texas

    USGS Publications Warehouse

    Baker, R.C.; Dale, O.C.

    1964-01-01

    Further studies should be made in the area to correct important deficiencies in available information. A continuing program is recommended because information such as fluctuations in water levels and the amount and distribution of pumping can be obtained only on a current basis.

  5. South Texas coastal classification maps - Mansfield Channel to the Rio Grande

    USGS Publications Warehouse

    Morton, Robert A.; Peterson, Russell L.

    2006-01-01

    The Nation's rapidly growing coastal population requires reliable information regarding the vulnerability of coastal regions to storm impacts. This has created a need for classifying coastal lands and evaluating storm-hazard vulnerability. Government officials and resource managers responsible for dealing with natural hazards also need accurate assessments of potential storm impacts in order to make informed decisions before, during, and after major storm events. Both economic development and coastal-damage mitigation require integrated models of storm parameters, hazard vulnerability, and expected coastal responses. Thus, storm-hazard vulnerability assessments constitute one of the fundamental components of forecasting storm impacts. Each year as many as 10 to 12 hurricanes and tropical storms will be the focus of national attention. Of particular interest are intense hurricanes (Categories 3 to 5 of the Saffir-Simpson Hurricane Scale) that have the potential to cause substantial economic and environmental damage to the Atlantic and Gulf Coasts of the United States. These coastal regions include some of the largest metropolitan areas in the country and they continue to experience rapid population growth. Based on media reports, there is a general lack of public knowledge regarding how different coastal segments will respond to the same storm or how the same coastal segment will respond differently depending on storm conditions. A primary purpose of the USGS National Assessment of Coastal Change Project is to provide accurate representations of pre-storm ground conditions for areas that are designated high priority because they have dense populations or valuable resources that are at risk. A secondary purpose is to develop a broad coastal classification that, with only minor modification, can be applied to most coastal regions in the United States.

  6. Houston, Galveston Bay, Texas, USA

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Less than an hour before this photo was taken, a large explosion and fire occurred at a petrochemical plant in Mount Belvieu, just to the east of Houston, Texas (29.5N, 95.0W). The fire has just started and the smoke plume is fairly small but by the end of the day, smoke obscured most of the area east of Houston. The spider-web network of highways radiating from the center of Houston is easily seen as well as the Astrodome and other features.

  7. CHAMBERS FERRY ROADLESS AREA, TEXAS.

    USGS Publications Warehouse

    Houser, B.B.; Ryan, George S.

    1984-01-01

    A geologic and geochemical investigation of the Chambers Ferry Roadless Area, Texas was conducted. The area has probable mineral-resource potential for oil and gas and for lignite. No metallic or additional energy resources were identified in the investigation. Detailed analyses of well logs from the vicinity of the Chambers Ferry Roadless Area, in conjunction with seismic data, are necessary to determine if the subsurface stratigraphy and structure are favorable for the accumulation of oil and gas. A shallow drilling program involving coring on a close-space grid is necessary for determination of the rank and continuity of seams of lignitic sediments in the area.

  8. Texas Solar Collaboration Action Plan

    SciTech Connect

    Winland, Chris

    2013-02-14

    Texas Solar Collaboration Permitting and Interconenction Process Improvement Action Plan. San Antonio-specific; Investigate feasibility of using electronic signatures; Investigate feasibility of enabling other online permitting processes (e.g., commercial); Assess need for future document management and workflow/notification IT improvements; Update Information Bulletin 153 regarding City requirements and processes for PV; Educate contractors and public on CPS Energy’s new 2013 solar program processes; Continue to discuss “downtown grid” interconnection issues and identify potential solutions; Consider renaming Distributed Energy Resources (DER); and Continue to participate in collaborative actions.

  9. Water-quality and ancillary data collected from the Arroyo Colorado near Rio Hondo, Texas, 2006

    USGS Publications Warehouse

    Roussel, Meghan C.; Canova, Michael G.; Asquith, William H.; Kiesling, Richard L.

    2007-01-01

    The Arroyo Colorado is in the lower Rio Grande Valley of southern Texas and extends from near Mission, Texas, eastward to the Laguna Madre estuarine and coastal marine system, which separates Padre Island from the Texas mainland. Streamflow in the Arroyo Colorado primarily is sustained by effluent from municipal wastewater-treatment plants along the stream banks. Since 1986, the tidal segment of the Arroyo Colorado from the port of Harlingen to the Laguna Madre has been designated by the State of Texas as an impaired water body because of low dissolved oxygen concentrations. Efforts to develop predictive water-quality models for the tidal segment of the Arroyo Colorado have been hampered by a lack of physical, biological, and biochemical data. Specifically, data on primary algal productivity, nutrient cycling, sediment deposition rates, and the relations between these processes and dissolved oxygen dynamics in the stream have been inadequate to support water-quality modeling efforts. The U.S. Geological Survey, in cooperation with the Texas Commission on Environmental Quality, did a study in 2006 to collect data associated with primary algal productivity, nutrient cycling, and dissolved oxygen dynamics in the tidal segment (2201) of the Arroyo Colorado near Rio Hondo. Specific objectives of the study were to (1) characterize water quality by measuring basic properties; (2) characterize the concentrations of carbon and nutrients, biochemical oxygen demand, total organic carbon, total suspended solids, and volatile suspended solids; (3) measure the seasonal differences of nutrient-dependent algal growth and algal production in the water column; (4) measure oxygen respiration or production rates; and (5) measure rates of sediment deposition.

  10. Ground-Water Availability Responses to Climate Variability on Interannual to Multidecadal Timescales, Mississippi Embayment Regional Aquifer System, USA

    NASA Astrophysics Data System (ADS)

    Gurdak, J. J.; Clark, B. R.; Hanson, R. T.; Scheiderer, R. M.

    2008-12-01

    Climate variability on interannual to multidecadal timescales has important implications for the availability of global ground-water resources. Spatiotemporal patterns in precipitation, air temperature, evapotranspiration, drought, streamflow, and recharge are partially controlled by the variability in climate forcings on interannual to multidecadal timescales. Because these climate-varying conditions can augment or diminish human stresses (pumping) on ground water, the responses in water levels and ground-water storage can be dramatic when different climate cycles lie coincident in a positive (wet/cool) or negative (dry/warm) phase of variability. Thus, understanding climate cycles on these timescales has particular relevance for management decisions during drought and for ground-water resources close to the limits of sustainability. The objective of this study is to quantify the response of ground-water resources in the Mississippi Embayment Regional aquifer system (USA) (>181,000 km2) to natural climate variability on interannual to multidecadal timescales and to use that knowledge to improve calibration of ground-water availability modeling that will predict the responses in this regional aquifer system over the next twenty-five to fifty years. The Mississippi Embayment Regional aquifer system is an important water resource used predominantly for public-drinking and agricultural supply across parts of seven States (Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee). Using singular spectrum analysis of long-term hydrologic time series, the signal of ground-water pumping was removed and natural variations were identified in all tree ring, precipitation, air temperature, and ground-water level time series as partially coincident with known climate forcings; including the El Nino/Southern Oscillation (2 to 6 year cycle), the Pacific Decadal Oscillation (10 to 25 year cycle), and the Atlantic Multidecadal Oscillation (50 to 80 year cycle

  11. Sedimentary architecture of the Amundsen Sea Embayment shelf, West Antarctica, from pre-glacial to glacial processes

    NASA Astrophysics Data System (ADS)

    Gohl, Karsten; Uenzelmann-Neben, Gabriele; Hillenbrand, Claus-Dieter; Larter, Robert; Nitsche, Frank

    2013-04-01

    Studies of the sedimentary architecture and characteristics of Antarctic shelves provide clues of past ice sheet advance-retreat cycles and help improve constraints for paleo-ice dynamic models since early glacial periods. A first seismostratigraphic analysis of the Amundsen Sea Embayment shelf and slope of West Antarctica reveals insights into the structural architecture of the continental margin and shows stages of sediment deposition, erosion and transport history from pre-glacial times to early glaciation and to the most recent glacial periods. The shelf geometry consists of a large pre- and syn-rift basin in the middle shelf region between outcropping basement of the inner shelf and basement ridges and highs beneath the outer shelf. A middle shelf sub-basin exists which may have formed as a result of motion along an early West Antarctic Rift System branch. At least 4 km of pre-glacial strata has been eroded from the present inner shelf and coastal hinterland by ice sheet advances since the onset of glaciation. Some of the eroded sediments were deposited as a progradational wedge extending the outer shelf by 25 to 65 km oceanward of the pre-glacial shelf-break. Comparing the observed seismic characteristics with those of other Antarctic shelf sequences, we assign an Early Cretaceous age for bottom sedimentary unit ASS-1, a Late Cretaceous to Oligocene age for unit ASS-2, an Early to Mid-Miocene age for unit ASS-3, a Mid-Miocene age for unit ASS-4, a Late Miocene to Early Pliocene age for unit ASS-5, and a Pliocene to Pleistocene age for the top unit ASS-6. The survival of buried grounding zone wedges in the upper part of unit ASS-5 of the outer shelf is consistent with the onset of a long warming phase and a retreated ice sheet in the early Pliocene as observed for the Ross Sea shelf and reconstructed from paleo-ice sheet models. Our data also reveal that the paleo-ice flow paths of the central Pine Island Trough system have remained stationary across the

  12. Modern sedimentation processes in a wave-dominated coastal embayment: Espírito Santo Bay, southeast Brazil

    NASA Astrophysics Data System (ADS)

    Bastos, Alex Cardoso; Costa Moscon, Daphnne Moraes; Carmo, Dannilo; Neto, José Antonio Baptista; da Silva Quaresma, Valéria

    2015-02-01

    Sediment dynamics in wave-dominated coastal embayments are generally controlled by seasonal meteorological conditions, storms having a particularly strong influence. In the present study, such hydrodynamic processes and associated deposits have been investigated in a coastal embayment located along the southeast coast of Brazil, i.e. Espírito Santo Bay, in the winter (June/July) of 2008. The bay has undergone a series of human interventions that have altered the local hydrodynamic processes and, consequently, the sediment transport patterns. Facies distribution and sediment dynamics were examined by acoustic seabed mapping, sediment and core sampling, hydrodynamic measurements and sand transport modelling. The results show that sediment distribution can be described in terms of nearshore and offshore zones. The offshore bay sector is predominantly composed of "palimpsest" lithoclastic medium-coarse sands deposited in the course of the early Holocene transgression that peaked about 5,000 years ago. In the inner bay or nearshore zone (up to depths of 4-8 m), these older transgressive deposits are today overlain by a thin (up to 30-cm-thick) and partly patchy blanket of younger regressive fine sand/muddy fine sands. Both coarse- and fine-grained facies are being reworked during high-energy events (Hs>1.5 m) when fine sediment is resuspended, weak tide-induced drift currents causing the sand patches to be displaced. The coarser sediment, by contrast, is mobilized as bedload to produce wave ripples with spacings of up to 1.2 m. These processes lead to a sharp spatial delimitation between a fine sand/mud facies and a rippled coarse sand facies. The fine sand patches have a relief of about 20-30 cm and reveal a typical internal tempestite depositional sequence. Fair-weather wave-induced sediment transport (Hs<1 m), supported by weak tidal currents, seems to only affect the fine sediment facies. Sediment dynamics in Espírito Santo Bay is thus essentially controlled by

  13. View of upstream face of the forebay dam of Grand ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of upstream face of the forebay dam of Grand Coulee Dam, looking west. Construction of the forebay dam, which replaced the eastern end of the original Grand Coulee Dam, was completed in 1974. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  14. Grand challenges for biological engineering.

    PubMed

    Yoon, Jeong-Yeol; Riley, Mark R

    2009-09-22

    Biological engineering will play a significant role in solving many of the world's problems in medicine, agriculture, and the environment. Recently the U.S. National Academy of Engineering (NAE) released a document "Grand Challenges in Engineering," covering broad realms of human concern from sustainability, health, vulnerability and the joy of living. Biological engineers, having tools and techniques at the interface between living and non-living entities, will play a prominent role in forging a better future. The 2010 Institute of Biological Engineering (IBE) conference in Cambridge, MA, USA will address, in part, the roles of biological engineering in solving the challenges presented by the NAE. This letter presents a brief outline of how biological engineers are working to solve these large scale and integrated problems of our society.

  15. Gravity and grand unified theories

    NASA Astrophysics Data System (ADS)

    Parker, L.; Toms, D. J.

    1985-02-01

    Curvature-dependent consequences of grand unified theories (GUTs) for the evolution of the very early universe are investigated, considering the possibility that at high curvature and particle energies of 10 to the 24th eV the effective values of the coupling constants governing the strength of the curvature-matter interaction are largely determined by the elementary-particle content defined by the particular GUT. The GUTs examined include those of Georgi and Glashow (1974) and Chang et al. (1980), and the coupling constants studied are the cosmological Lambda, Newtonian G, xi(phi) and xi(H) linking curvature and the scalar Higgs bosons, and alpha(i) (coefficients of action terms quadratically dependent on the curvature tensor).

  16. Grand unification of neutron stars.

    PubMed

    Kaspi, Victoria M

    2010-04-20

    The last decade has shown us that the observational properties of neutron stars are remarkably diverse. From magnetars to rotating radio transients, from radio pulsars to isolated neutron stars, from central compact objects to millisecond pulsars, observational manifestations of neutron stars are surprisingly varied, with most properties totally unpredicted. The challenge is to establish an overarching physical theory of neutron stars and their birth properties that can explain this great diversity. Here I survey the disparate neutron stars classes, describe their properties, and highlight results made possible by the Chandra X-Ray Observatory, in celebration of its 10th anniversary. Finally, I describe the current status of efforts at physical "grand unification" of this wealth of observational phenomena, and comment on possibilities for Chandra's next decade in this field.

  17. Grand unification of neutron stars

    PubMed Central

    Kaspi, Victoria M.

    2010-01-01

    The last decade has shown us that the observational properties of neutron stars are remarkably diverse. From magnetars to rotating radio transients, from radio pulsars to isolated neutron stars, from central compact objects to millisecond pulsars, observational manifestations of neutron stars are surprisingly varied, with most properties totally unpredicted. The challenge is to establish an overarching physical theory of neutron stars and their birth properties that can explain this great diversity. Here I survey the disparate neutron stars classes, describe their properties, and highlight results made possible by the Chandra X-Ray Observatory, in celebration of its 10th anniversary. Finally, I describe the current status of efforts at physical “grand unification” of this wealth of observational phenomena, and comment on possibilities for Chandra’s next decade in this field. PMID:20404205

  18. Google Earth Grand Tour Themes

    NASA Astrophysics Data System (ADS)

    De Paor, D. G.; Whitmeyer, S. J.; Bentley, C.; Dordevic, M. M.

    2014-12-01

    As part of an NSF TUES Type 3 project entitled "Google Earth for Onsite and Distance Education (GEODE)," we are assembling a "Grand Tour" of locations on Earth and other terrestrial bodies that every geoscience student should know about and visit at least in virtual reality. Based on feedback from colleagues at previous meetings, we have identified nine Grand Tour themes: "Plates and Plumes," "Rocks and Regions," "Geology Through Time," "The Mapping Challenge*," "U.S. National Parks*," "The Magical Mystery Tour*," "Resources and Hazards," "Planets and Moons," and "Top of the Pops." Themes marked with an asterisk are most developed at this stage and will be demonstrated in real time. The Mapping Challenge invites students to trace geological contacts, measure bedding strike and dip and the plunge, trend, and facing of a fold. There is an advanced tool for modeling periclinal folds. The challenge is presented in a game-like format with an emphasis on puzzle-solving that will appeal to students regardless of gender. For the tour of U.S. national parks, we divided the most geologically important parks into four groups—Western Pacific, West Coast, Rockies, and East Coast. We are combining our own team's GigaPan imagery with imagery already available on the Internet. There is a great deal of imagery just waiting to be annotated for geological education purposes. The Magical Mystery Tour takes students to Google Streetview locations selected by instructors. Students are presented with questions or tasks and are given automatic feedback. Other themes are under development. Within each theme, we are crowd-sourcing contributions from colleagues and inviting colleagues to vote for or against proposed locations and student interactions. The GEODE team includes the authors and: Heather Almquist, Stephen Burgin, Cinzia Cervato, Gene Cooper, Paul Karabinos, Terry Pavlis, Jen Piatek, Bill Richards, Jeff Ryan, Ron Schott, Kristen St. John, and Barb Tewksbury.

  19. 33 CFR 117.285 - Grand Canal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Grand Canal. 117.285 Section 117.285 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.285 Grand Canal. (a) The draw of the Lansing Island bridge, mile 0.7, shall open on...

  20. FOI and Fire at the MGM Grand.

    ERIC Educational Resources Information Center

    Thompson, William N.; Marie, Janice

    The fire at the MGM Grand Hotel in Las Vegas, Nevada, brought to light a lack of compliance with the freedom of information philosophy and its supporting statutes. Freedom of information means circulation of important information. However, at the Grand Hotel, the hotel staff had not been properly trained in disaster procedures, the escape…

  1. Quaternary faults of west Texas

    SciTech Connect

    Collins, E.W.; Raney, J.A. . Bureau of Economic Geology)

    1993-04-01

    North- and northwest-striking intermontane basins and associated normal faults in West Texas and adjacent Chihuahua, Mexico, formed in response to Basin and Range tectonism that began about 24 Ma ago. Data on the precise ages of faulted and unfaulted Quaternary deposits are sparse. However, age estimates made on the basis of field stratigraphic relationships and the degree of calcic soil development have helped determine that many of the faults that bound the basin margins ruptured since the middle Pleistocene and that some faults probably ruptured during the Holocene. Average recurrence intervals between surface ruptures since the middle Pleistocene appear to be relatively long, about 10,000 to 100,000 yr. Maximum throw during single rupture events have been between 1 and 3 m. Historic seismicity in West Texas is low compared to seismicity in many parts of the Basin and Range province. The largest historic earthquake, the 1931 Valentine earthquake in Ryan Flat/Lobo Valley, had a magnitude of 6.4 and no reported surface rupture. The most active Quaternary faults occur within the 120-km-long Hueco Bolson, the 70-km-long Red Light Bolson, and the > 200-km-long Salt Basins/Wild Horse Flat/Lobo Valley/Ryan Flat.

  2. Texas Public School Technology Survey, 1988. Final Report.

    ERIC Educational Resources Information Center

    Denton, Jon; Davis, Trina; Strader, Arlen; Jessup, George

    The Texas Association of School Administrators (TASA) with technical support from the South Central Regional Technology in Education Consortia-Texas (SCR*TEC-TX) conducted a survey of the technology infrastructure in all public schools in Texas. This document provides the final report of the 1998 Texas Public School Technology Survey. Following…

  3. 27 CFR 9.155 - Texas Davis Mountains.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Texas Davis Mountains. 9... Texas Davis Mountains. (a) Name. The name of the viticultural area described in this section is “Texas Davis Mountains.” (b) Approved map. The appropriate maps for determining the boundary of the Texas...

  4. 27 CFR 9.136 - Texas Hill Country.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Austin, Texas, 1954 (revised 1974); (5) Del Rio, Texas, 1958 (revised 1969); (6) San Antonio, Texas, 1954... is the intersection of Interstate Highway 35 and State highway 29 to the north of the city of Austin, on the Austin Texas, U.S.G.S. map; (2) From the beginning point, the boundary follows State...

  5. 27 CFR 9.136 - Texas Hill Country.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Austin, Texas, 1954 (revised 1974); (5) Del Rio, Texas, 1958 (revised 1969); (6) San Antonio, Texas, 1954... is the intersection of Interstate Highway 35 and State highway 29 to the north of the city of Austin, on the Austin Texas, U.S.G.S. map; (2) From the beginning point, the boundary follows State...

  6. 27 CFR 9.136 - Texas Hill Country.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Austin, Texas, 1954 (revised 1974); (5) Del Rio, Texas, 1958 (revised 1969); (6) San Antonio, Texas, 1954... is the intersection of Interstate Highway 35 and State highway 29 to the north of the city of Austin, on the Austin Texas, U.S.G.S. map; (2) From the beginning point, the boundary follows State...

  7. 27 CFR 9.136 - Texas Hill Country.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Austin, Texas, 1954 (revised 1974); (5) Del Rio, Texas, 1958 (revised 1969); (6) San Antonio, Texas, 1954... is the intersection of Interstate Highway 35 and State highway 29 to the north of the city of Austin, on the Austin Texas, U.S.G.S. map; (2) From the beginning point, the boundary follows State...

  8. 27 CFR 9.144 - Texas High Plains.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...” 1954, revised 1975. (6) “Big Spring, Texas” 1954, revised 1975. (c) Boundary. The Texas High Plains...; (2) The boundary follows U.S. Route 180 east through Seminole, Texas and onto the Big Spring, Texas... the U.S.G.S. maps of Big Spring and Lubbock, Texas; (4) The boundary continues along the 3,000...

  9. 27 CFR 9.155 - Texas Davis Mountains.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Texas Davis Mountains. 9... Texas Davis Mountains. (a) Name. The name of the viticultural area described in this section is “Texas Davis Mountains.” (b) Approved map. The appropriate maps for determining the boundary of the Texas...

  10. 27 CFR 9.155 - Texas Davis Mountains.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Texas Davis Mountains. 9... Texas Davis Mountains. (a) Name. The name of the viticultural area described in this section is “Texas Davis Mountains.” (b) Approved map. The appropriate maps for determining the boundary of the Texas...

  11. 27 CFR 9.155 - Texas Davis Mountains.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Texas Davis Mountains. 9... Texas Davis Mountains. (a) Name. The name of the viticultural area described in this section is “Texas Davis Mountains.” (b) Approved map. The appropriate maps for determining the boundary of the Texas...

  12. 27 CFR 9.155 - Texas Davis Mountains.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Texas Davis Mountains. 9... Texas Davis Mountains. (a) Name. The name of the viticultural area described in this section is “Texas Davis Mountains.” (b) Approved map. The appropriate maps for determining the boundary of the Texas...

  13. The Texas Childhood Hunger Identification Project. Final Report.

    ERIC Educational Resources Information Center

    Center for the Public Policy Priorities, Austin, TX.

    The final report of the Texas Childhood Hunger Identification Project (Texas CHIP), this document describes the most comprehensive study of childhood hunger undertaken in Texas. Through enumeration and interviewing methods, low-income families from 27 counties in Texas were analyzed in the areas of income allocation, food frequency, homelessness,…

  14. 75 FR 61461 - Texas Gas Transmission, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Federal Energy Regulatory Commission Texas Gas Transmission, LLC; Notice of Application September 28, 2010. Take notice that on September 22, 2010, Texas Gas Transmission, LLC (Texas Gas), 3800 Frederica Street.... Fort, Manager of Certificates and Tariffs, Texas Gas Transmission, LLC, 3800 Frederica...

  15. 78 FR 43874 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application On July 2, 2013, Texas Eastern Transmission, LP (Texas Eastern) filed with the Federal Energy Regulatory Commission (Commission... Eastern Transmission, LP, P.O. Box 1642, Houston, Texas, 77251-1642, or by calling (713) 627-4102; by...

  16. 78 FR 36178 - Texas Gas Transmission, LLC; Notice Of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Texas Gas Transmission, LLC; Notice Of Application Take notice that on May 29, 2013, Texas Gas Transmission, LLC (Texas Gas), 9 Greenway Plaza, Suite 2800, Houston, Texas...

  17. Two Texas Colleges Buy into the Big Time.

    ERIC Educational Resources Information Center

    Business Week, 1983

    1983-01-01

    Revenues from oil/gas royalties on University of Texas (Austin) and Texas A&M go into a fund which is used to hire faculty and develop programs, particularly in the sciences. However, Texas legislators are considering a bill that would spread the oil money to other campuses in the Texas university system. (JN)

  18. Social, political, and institutional setting: Water management problems of the Rio Grande

    USGS Publications Warehouse

    Douglas, A.J.

    2009-01-01

    This paper discusses various water management issues facing federal, state, and local agencies charged with managing the water resources of the Rio Grande River Basin and its major tributaries. The Rio Grande - 3,058 km (=1,900 mi) long - is the fourth longest river in the United States. The river's basin is 870,236 km2 (=336,000 mi2) and for roughly two-thirds of its length it forms the United States-Mexican border. It is a major recreational resource providing world class trout fishing near its headwaters in Colorado's San Juan Mountains and shoreline, angling, and boating opportunities near the Colorado-New Mexico border. The Rio Grande is the principal tourist attraction of Big Bend National Park and flows through downtown Albuquerque and El Paso. Many reaches are wide and broad, but almost all are relatively shallow and not navigable by commercial ships. Nevertheless, it is one of the most important renewable water resources of the southwestern United States and North America. The issue of the "manageability" of the river in the face of social forces and disparate administrative jurisdictions that adversely impact Rio Grande flows is a thread linking various sections of the paper together. The length of the river; the fact that major reaches lie in Colorado, New Mexico, and Texas; and its unique role as an international boundary pose complex management problems. The allocation status quo formed by the complex nexus of existing river laws make it difficult to reshape Rio Grande management. ?? 2009 ASCE.

  19. Topographic analysis for tectonic geomorphology using digital image processing of elevation data from the Mississippi embayment and adjacent areas

    SciTech Connect

    Mayer, L. . Dept. of Geology)

    1993-03-01

    Image processing of digital elevation data provides a framework within which to evaluate the relative importance of tectonic and erosional signatures on the landscape. Shaded relief imaging of the elevation data illuminates regional topographic features coincident with the physiographic provinces bounding the Mississippi embayment portion of the Coastal Plain: the Ozark Plateaus and Ouachitas on the west, the Central Lowland on the north, and the Interior Low Plateaus on the east. Grayscale or colors from custom color lookup tables are assigned based on elevation. Stretching can be used to enhance a particular elevation range while spatial convolution kernels can be used to provide a robust and rapid means of designing high- and low-pass filters for the purpose of restricting the frequency range examined. Thresholding the elevation ranges and assigning boundaries of the resultant binary images allow for the rapid delineation of topographic contour lines and permits quantization of planform geometry. Forty one-degree by 30-minute quadrangles have been imaged for the purpose of delineating topographic features of possible tectonic origin.

  20. Reconstructing the Last Glacial Maximum ice sheet in the Weddell Sea embayment, Antarctica, using numerical modelling constrained by field evidence

    NASA Astrophysics Data System (ADS)

    Le Brocq, A. M.; Bentley, M. J.; Hubbard, A.; Fogwill, C. J.; Sugden, D. E.; Whitehouse, P. L.

    2011-09-01

    The Weddell Sea Embayment (WSE) sector of the Antarctic ice sheet has been suggested as a potential source for a period of rapid sea-level rise - Meltwater Pulse 1a, a 20 m rise in ˜500 years. Previous modelling attempts have predicted an extensive grounding line advance in the WSE, to the continental shelf break, leading to a large equivalent sea-level contribution for the sector. A range of recent field evidence suggests that the ice sheet elevation change in the WSE at the Last Glacial Maximum (LGM) is less than previously thought. This paper describes and discusses an ice flow modelling derived reconstruction of the LGM ice sheet in the WSE, constrained by the recent field evidence. The ice flow model reconstructions suggest that an ice sheet consistent with the field evidence does not support grounding line advance to the continental shelf break. A range of modelled ice sheet surfaces are instead produced, with different grounding line locations derived from a novel grounding line advance scheme. The ice sheet reconstructions which best fit the field constraints lead to a range of equivalent eustatic sea-level estimates between approximately 1.4 and 3 m for this sector. This paper describes the modelling procedure in detail, considers the assumptions and limitations associated with the modelling approach, and how the uncertainty may impact on the eustatic sea-level equivalent results for the WSE.

  1. Atypical residency of short-beaked common dolphins (Delphinus delphis) to a shallow, urbanized embayment in south-eastern Australia

    PubMed Central

    Salgado Kent, Chandra; Donnelly, David; Weir, Jeffrey; Bilgmann, Kerstin

    2016-01-01

    Short-beaked common dolphins (Delphinus delphis) are typically considered highly mobile, offshore delphinids. This study assessed the residency of a small community of short-beaked common dolphins in the shallow, urbanized Port Phillip Bay, south-eastern Australia. The ability to identify common dolphins by their dorsal fin markings and coloration using photo-identification was also investigated. Systematic and non-systematic boat surveys were undertaken between 2007 and 2014. Results showed that 13 adult common dolphins and their offspring inhabit Port Phillip Bay, of which 10 adults exhibit residency to the bay. The majority of these adults are reproductively active females, suggesting that female philopatry may occur in the community. Systematic surveys conducted between 2012 and 2014 revealed that the dolphins were found in a median water depth of 16 m and median distance of 2.2 km from the coast. The shallow, urbanized habitat of this resident common dolphin community is atypical for this species. As a result, these common dolphins face threats usually associated with inshore bottlenose dolphin communities. We suggest that the Port Phillip Bay common dolphin community is considered and managed separate to those outside the embayment and offshore to ensure the community's long-term viability and residency in the bay. PMID:27703709

  2. Geologic mapping of near-surface sediments in the northern Mississippi Embayment, McCracken County, KY

    SciTech Connect

    Sexton, Joshua L; Fryar, Alan E; Greb, s F

    2006-04-01

    POSTER: The Jackson Purchase region of western Kentucky consists of Coastal Plain sediments near the northern margin of the Mississippi Embayment. Within this region is the Paducah Gaseous Diffusion Plant (PGDP), a uranium enrichment facility operated by the US Department of Energy. At PGDP, a Superfund site, soil and groundwater studies have provided subsurface lithologic data from hundreds of monitoring wells and borings. Despite preliminary efforts by various contractors, these data have not been utilized to develop detailed stratigraphic correlations of sedimentary units across the study area. In addition, sedimentary exposures along streams in the vicinityof PGDP have not been systematically described beyond the relatively simple geologic quadrangle maps published by the US Geological Survey in 1966-67. This study integrates lithologic logs, other previous site investigation data, and outcrop mapping to provide a compilation of near-surface lithologic and stratigraphic data for the PGDP area. A database of borehole data compiled during this study has been provided to PGDP for future research and archival.

  3. Effect of selection and sequencing of representative wave conditions on process-based predictions of equilibrium embayed beach morphology

    NASA Astrophysics Data System (ADS)

    Daly, Christopher J.; Bryan, Karin R.; Gonzalez, Mauricio R.; Klein, Antonio H. F.; Winter, Christian

    2014-06-01

    In order to decrease the simulation time of morphodynamic models, often-complex wave climates are reduced to a few representative wave conditions (RWC). When applied to embayed beaches, a test of whether a reduced wave climate is representative or not is to see whether it can recreate the observed equilibrium (long-term averaged) bathymetry of the bay. In this study, the wave climate experienced at Milagro Beach, Tarragona, Spain was discretized into `average' and `extreme' RWCs. Process-based morphodynamic simulations were sequenced and merged based on `persistent' and `transient' forcing conditions, the results of which were used to estimate the equilibrium bathymetry of the bay. Results show that the effect of extreme wave events appeared to have less influence on the equilibrium of the bay compared to average conditions of longer overall duration. Additionally, the persistent seasonal variation of the wave climate produces pronounced beach rotation and tends to accumulate sediment at the extremities of the beach, rather than in the central sections. It is, therefore, important to account for directional variability and persistence in the selection and sequencing of representative wave conditions as is it essential for accurately balancing the effects beach rotation events.

  4. Processes affecting geochemistry and contaminant movement in the middle Claiborne aquifer of the Mississippi embayment aquifer system

    USGS Publications Warehouse

    Katz, Brian G.; Kingsbury, James A.; Welch, Heather L.; Tollett, Roland W.

    2012-01-01

    Groundwater chemistry and tracer-based age data were used to assess contaminant movement and geochemical processes in the middle Claiborne aquifer (MCA) of the Mississippi embayment aquifer system. Water samples were collected from 30 drinking-water wells (mostly domestic and public supply) and analyzed for nutrients, major ions, pesticides, volatile organic compounds (VOCs), and transient age tracers (chlorofluorocarbons, tritium and helium-3, and sulfur hexafluoride). Redox conditions are highly variable throughout the MCA. However, mostly oxic groundwater with low dissolved solids is more vulnerable to nitrate contamination in the outcrop areas east of the Mississippi River in Mississippi and west Tennessee than in mostly anoxic groundwater in downgradient areas in western parts of the study area. Groundwater in the outcrop area was relatively young (apparent age of less than 40 years) with significantly (p 50 m depth) indicated contaminant movement from shallow parts of the aquifer into deeper oxic zones. Given the persistence of nitrate in young oxic groundwater that was recharged several decades ago, and the lack of a confining unit, the downward movement of young contaminated water may result in higher nitrate concentrations over time in deeper parts of the aquifer containing older oxic water.

  5. Atypical residency of short-beaked common dolphins (Delphinus delphis) to a shallow, urbanized embayment in south-eastern Australia.

    PubMed

    Mason, Suzanne; Salgado Kent, Chandra; Donnelly, David; Weir, Jeffrey; Bilgmann, Kerstin

    2016-09-01

    Short-beaked common dolphins (Delphinus delphis) are typically considered highly mobile, offshore delphinids. This study assessed the residency of a small community of short-beaked common dolphins in the shallow, urbanized Port Phillip Bay, south-eastern Australia. The ability to identify common dolphins by their dorsal fin markings and coloration using photo-identification was also investigated. Systematic and non-systematic boat surveys were undertaken between 2007 and 2014. Results showed that 13 adult common dolphins and their offspring inhabit Port Phillip Bay, of which 10 adults exhibit residency to the bay. The majority of these adults are reproductively active females, suggesting that female philopatry may occur in the community. Systematic surveys conducted between 2012 and 2014 revealed that the dolphins were found in a median water depth of 16 m and median distance of 2.2 km from the coast. The shallow, urbanized habitat of this resident common dolphin community is atypical for this species. As a result, these common dolphins face threats usually associated with inshore bottlenose dolphin communities. We suggest that the Port Phillip Bay common dolphin community is considered and managed separate to those outside the embayment and offshore to ensure the community's long-term viability and residency in the bay.

  6. Determining Environmental Factors Controlling Nitrogen Cycling in the Semi-Arid Rio Grande Using Nitrogen and Oxygen Isotopes

    NASA Astrophysics Data System (ADS)

    Sanchez, D. A.; Szynkiewicz, A.; Faiia, A. M.

    2015-12-01

    The Rio Grande is a semi-arid river in the American Southwest supporting agriculture and large populous centers in New Mexico and west Texas. In addition to increasing salinity, considerable increases of nitrate (NO3), up to ~50 mg/L, have been previously observed in the Rio Grande between Las Cruces, New Mexico and El Paso, Texas. This is particularly a problem during non-irrigation season when little surface water is released from upstream reservoirs, substantially reducing stream flows in the Rio Grande. While both irrigation runoff and municipal waste effluents are likely important NO3 contributors, there are no quantitative studies assessing NO3 fluxes to the Rio Grande from these two sources. Therefore, in this study we used 𝛿15N and 𝛿18O values of NO3 as environmental tracers to characterize major NO3 sources in the Rio Grande and its agricultural drains between Las Cruces and El Paso. Surface water of the semi-arid Rio Grande, drains and major wastewater treatment plants were collected in October 2014 (non-irrigation season) and August 2015 (irrigation season). The water samples from the 2014 sampling campaign showed that the 𝛿15N and 𝛿18O values of NO3 in the Rio Grande and two agricultural drains located south of El Paso varied in relatively narrow range from +9.8 to +15.7‰ and -5.9 to -0.2‰, respectively. These ranges were similar to 𝛿15N and 𝛿18O values of local wastewater treatment plants in Las Cruces and El Paso, from +8.2 to +10.2‰ and -9.7 to -2.5‰ respectively. Municipal wastewater effluents are important tributaries to the semi-arid Rio Grande in the studied area, particularly during non-irrigation season. Furthermore, irrigation of agricultural fields south of El Paso is to a large extent supported by reclaimed municipal wastewater. Consequently, these explain the observed higher contributions of NO3 from urban sources in the investigated area.

  7. 17. Photocopy of photograph (original contact print in Grand Rapids ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Photocopy of photograph (original contact print in Grand Rapids Michigan City Library, Michigan Room) circa 1908, photographer unknown. VIEW NORTH - NORTHEAST, SOUTHSIDE, GENERAL VIEW. - Bridge Street Bridge, Spanning Grand River, Michigan & Bridge Streets, Grand Rapids, MI

  8. U.S. Geological Survey response to flooding in Texas, May–June 2015

    USGS Publications Warehouse

    East, Jeffery W.

    2016-04-26

    National Weather Service flood stage being exceeded at USGS streamgages on numerous rivers. The widespread and prolonged nature of the flooding was unusual; most flood events in Texas are localized, typically affecting only one or two river basins and generally lasting only a few days. With the exception of the Rio Grande, flooding was widespread in all of the major rivers in Texas during May–June 2015.

  9. "In the middle of an orange grove, across the street from the tortilla factory": The Science Academy of South Texas

    NASA Astrophysics Data System (ADS)

    Canter, Anna Rudolph

    2004-12-01

    The Science Academy of South Texas, one of four magnet schools in The South Texas Independent School District (STISD), opened in 1989 to bring educational opportunities in mathematics and science to students in the Rio Grande Valley of South Texas. STISD serves three counties and offers enrollment to any student who applies from any of the twenty-eight feeder districts. The Science Academy is the only mathematics and science magnet school in the Rio Grande Valley. Over years, Science Academy has developed partnerships with major colleges and universities in Houston, Texas and the Rio Grande Valley. University partnerships have provided funding for programs at the school and have created continuing summer study programs for Science Academy students. Graduates have been accepted to and/or attended some of the most prestigious colleges and universities across the United States, despite personal challenges including low socioeconomic status, English as their second language, and being the first in their family to attend college. This historical study seeks to answer two basic questions. How has the Science Academy faced its academic, political, and social challenges over the years? What factors appear to have contributed to its establishment, survival, and success? Chapter One, "Significance of the Study and Research Methods" describes the study's significance within the scholarly literature and the research methods used for this study. Chapter Two, "The Science Academy of South Texas" presents the history of STISD and the events which precipitated Science Academy's establishment. Chapter Three, "The Administration, Faculty and Staff of Science Academy," discusses administration and faculty of the Science Academy. Its focus is Science Academy teachers and their educational beliefs as well as the administrators and staff and their beliefs. Chapter Four, "Curriculum Continuity and Change at the Science Academy," focuses on the curriculum history of Science Academy and

  10. Sediment Supply Versus Local Hydraulic Controls on Sediment Transport and Storage in the Rio Grande in the Big Bend Region

    NASA Astrophysics Data System (ADS)

    Dean, D. J.; Topping, D. J.; Schmidt, J. C.

    2015-12-01

    The Rio Grande in the Big Bend region of Texas, USA, and Chihuahua and Coahuila, Mexico, has a large sediment supply, and a variable hydrology resulting in rapid channel narrowing during years of low mean and peak flow, and channel widening during rare, large-magnitude floods. This dynamic nature makes the Rio Grande a useful natural laboratory to investigate the relative importance of flow strength and sediment supply in controlling channel change. We analyzed a suite of sediment-transport and geomorphic data to determine the cumulative influence of different flood types on changing channel form. In this study, physically-based analyses suggest that channel change on the Rio Grande is controlled by both changes in flow strength and sediment supply over different spatial and temporal scales. Channel narrowing is primarily caused by sediment supplied to the Rio Grande during flash floods on desert tributaries. Tributary floods have large suspended-sediment concentrations, occur for short durations, and attenuate rapidly downstream in the Rio Grande, depositing much of their sediment in downstream reaches. Long-duration floods on the mainstem are the only floods that have the capacity to enlarge the Rio Grande. These floods, released from upstream dams, can either erode or deposit sediment in the Rio Grande depending upon the antecedent in-channel sediment supply and the magnitude and duration of the flood. Geomorphic and sediment-transport analyses show that sand erosion and deposition during long-duration floods are most strongly controlled by the spatial distribution of flow strength as governed by channel slope. However, temporal changes in the grain size and amount of available sand within the channel, as inferred from comprehensive analyses of suspended-sediment concentration and grain size, control the degree of sediment evacuation or accumulation over large spatial scales.

  11. Integrated hydrologic modeling of a transboundary aquifer system —Lower Rio Grande

    USGS Publications Warehouse

    Hanson, Randall T.; Schmid, Wolfgang; Knight, Jacob E.; Maddock, Thomas

    2013-01-01

    For more than 30 years the agreements developed for the aquifer systems of the lower Rio Grande and related river compacts of the Rio Grande River have evolved into a complex setting of transboundary conjunctive use. The conjunctive use now includes many facets of water rights, water use, and emerging demands between the states of New Mexico and Texas, the United States and Mexico, and various water-supply agencies. The analysis of the complex relations between irrigation and streamflow supplyand-demand components and the effects of surface-water and groundwater use requires an integrated hydrologic model to track all of the use and movement of water. MODFLOW with the Farm Process (MFFMP) provides the integrated approach needed to assess the stream-aquifer interactions that are dynamically affected by irrigation demands on streamflow allotments that are supplemented with groundwater pumpage. As a first step to the ongoing full implementation of MF-FMP by the USGS, the existing model (LRG_2007) was modified to include some FMP features, demonstrating the ability to simulate the existing streamflow-diversion relations known as the D2 and D3 curves, departure of downstream deliveries from these curves during low allocation years and with increasing efficiency upstream, and the dynamic relation between surface-water conveyance and estimates of pumpage and recharge. This new MF-FMP modeling framework can now internally analyze complex relations within the Lower Rio Grande Hydrologic Model (LRGHM_2011) that previous techniques had limited ability to assess.

  12. Water sanitation practices on the Texas-Mexico border: implications for physicians on both sides.

    PubMed

    Cech, I; Essman, A

    1992-11-01

    With the epidemic of cholera in South and Central America and reports of cholera in the Northern Hemisphere in Mexico, increasing concern focuses on sanitation problems along the border between the United States and Mexico. It is feared that binationally shared water supplies are threatened or contaminated by sewage and other wastes. Although much anecdotal information exists, surprisingly few hard data are available in the United States (or in Mexico, for that matter) regarding water quality on the Mexican side of the border. This shortage of data is felt most acutely in the semiarid portions of the border, where water is extraordinarily scarce. In 1987, researchers at the University of Texas School of Public Health (UTSPH) began gathering data on the availability, accessibility, and bacteriologic and chemical safety of raw and finished drinking water in Mexico at its border with Texas. In view of their timely significance, we wish to share pertinent data. This particular study was carried out in Ciudad Juarez, a city of more than 1 million people, situated just across the Rio Grande from the Texas city of El Paso. The investigation was conducted at the invitation and with the assistance of municipal authorities of Cd. Juarez. As far as we know, this was the first time the water in Cd. Juarez had been tested for indicator fecal bacteria and other selected contaminants.

  13. The ecology of open-bay bottoms of Texas: A community profile

    SciTech Connect

    Armstrong, N.E.

    1987-05-01

    Open-bay bottoms represent one of the most extensive habitats in any estuarine system, especially in the northwestern Gulf of Mexico estuaries of Texas. Seven major estuarine systems are found here (Sabine Lake, Galveston Bay, Matagorda Bay, San Antonio Bay, Copano-Aransas Bays, Corpus Christi Bay, and the Laguna Madre), along with three minor riverine estuaries (Brazos, San Bernard, and Rio Grande) which long ago filled. These bays are typically broad and shallow with average depths of 1.2 to 2.4 m and a total surface area of 624,000 ha. Salt marshes and seagrass beds are small. The structure and function of the benthic communities in these Texas estuaries are examined by reviewing and integrating data from a number of past and ongoing studies. While studies in these systems have not been as numerous as in other estuaries, the patterns of structure and function are beginning to emerge. The key functions of the benthic system are production of biomass as food resources for higher trophic levels; bioturbation, which enhances nutrient regeneration; and nutrient regeneration itself. Benthic nutrient regeneration in the shallow waters of Texas estuaries may play a key role in regulating primary production in the estuaries. Managers of these estuaries must consider the open-bay bottom systems as a critical part of the overall function of these estuaries.

  14. SECURES: Austin, Texas demonstration results

    NASA Astrophysics Data System (ADS)

    Lewis, Glynn; Shaw, Scott; Scharf, Peter; Stellingworth, Bob

    2003-09-01

    The Law Enforcement technology development community has a growing interest in the technologies associated with gunshot detection and localization. These interests revolve around community-oriented policing. Technologies of interest include those associated with muzzle blast and bullet shockwave detection and the inter-netting of these acoustic sensors with electro-optic sensors. To date, no one sensor technology has proven totally effective for a complete solution. PSI has a muzzle blast detection and localization product which is wireless, highly mobile and reconfigurable, with a user-friendly laptop processor and display unit, which completed a one-year demonstration in Austin, Texas on July 6, 2002. This demonstration was conducted under a Cooperative Agreement with the National Institute of Justice and in cooperation with the Austin Police Department. This paper will discuss the details of the demonstrations, provide a summarized evaluation, elucidate the lessons learned, make recommendations for future deployments and discuss the developmental directions indicated for the future.

  15. Reservoir evaporation in Texas, USA

    NASA Astrophysics Data System (ADS)

    Wurbs, Ralph A.; Ayala, Rolando A.

    2014-03-01

    The role of reservoir surface evaporation in river/reservoir water budgets and water management is explored using a modeling system that combines historical natural hydrology with current conditions of water resources development and management. The long-term mean evaporation from the 3415 reservoirs in the Texas water rights permit system is estimated to be 7.53 billion m3/year, which is equivalent to 61% of total agricultural or 126% of total municipal water use in the state during the year 2010. Evaporation varies with the hydrologic conditions governing reservoir surface areas and evaporation rates. Annual statewide total evaporation volumes associated with exceedance probabilities of 75%, 50%, and 25% are 7.07, 7.47, and 7.95 billion m3/year, respectively. Impacts of evaporation are greatest during extended severe droughts that govern water supply capabilities.

  16. Solar Leasing Summary, Houston Texas

    SciTech Connect

    Hammer, Mary

    2013-02-14

    A relatively new option for homeowners looking to add solar to their home is the solar lease. At present, the solar lease option can be found in California, Arizona, Texas, Colorado, Hawaii, New York and Oregon. The most active companies currently offering solar leases are NRG Energy, Sungevity, Solar City and Sun Run. With the uncertainty and/or lack of subsidies the states participating in these programs have ebbed and flowed over the last few years. However, there is an expectation that in the current market solar leasing will make solar viable without the utility and federal subsidies. NRG Energy is currently testing this expectation in Houston, TX where currently no subsidies or incentives beyond the federal tax incentives, exist. Following is an explanation on the state of solar leasing in Houston, TX and explanation of the current financing options.

  17. Last workshop on grand unification

    SciTech Connect

    Frampton, P.H. . Dept. of Physics and Astronomy)

    1991-01-01

    The presentations at the workshop alternated between experiment and theory in the traditional manner. Let me introduce first all the experimental topics. For the proton decay experiments, their present status was provided by Ayres, Ernwein, Gajewski and Totsuka for the Soudan, Frejus, IMB and Kamioka groups respectively. Massive neutrinos were reviewed by Robertson, solar neutrinos by Bahcall, and double beta decay by Avignone. Monopole searches were covered by Barish. Other experimental talks concerned both astrophysics and the Standard Model. In astrophysics, Perlmutter presented the possible discovery of a sub- millisecond pulsar in supernova 1987A and Sadoulet outlined a program to search for dark matter. Within the Standard Model, Matthews reported the recent discovery of Z{sup 0} particle decays at SLC and Dehmelt described his high-accuracy measurement of (g-2){sub c}. The theoretical talks were on GUTs, extensions of the Standard Model, general relativity and strings, and theoretical astrophysics and cosmology. Langacker talked on grand unification, proton decay and neutrino masses.

  18. Introduction to Grand Unified Theories

    NASA Astrophysics Data System (ADS)

    Masiero, Antonio

    The following sections are included: * THE STANDARD MODEL: A CRITICAL APPRAISAL * The "Low Energy" Limit of Renormalizable Gauge Theories * The Standard Model: its purity * The Standard Model: its impurity * Vices and Virtues of the Standard Model * INTRODUCTION TO GRAND UNIFIED THEORIES * When "Strong" and "Weak" Merge Together * The "Big Desert" Picture of the World * A Persistent Cloud: the hierarchy problem * PHENOMENOLOGICAL CONSEQUENCES OF GUTs * What is New in GUTs * General Features of the B and L Violating Processes * A FIRST GLIMPSE AT THE SU(5) MODEL * Why SU(5)? * The Higgs Sector and the Hierarchy Nightmare * LOW ENERGY PHENOMENOLOGICAL CONSEQUENCES OF SU(5) * The Successful sin2θW Prediction of SU(5) * Fermion Masses in SU(5) * Mixing Angles and Phases * Proton Lifetime: A Death Blow to the SU(5) Model? * B-L and Neutrino Masses in SU(5) * SU(5): A Final Score * NEW PHYSICS NOT FAR FROM THE FERMI SCALE? * L-Right Symmetry: A Fundamental Symmetry? * Massive Majorana Neutrinos * Neutron -Antineutron Oscillations * Lepton Number as a Fourth Colour * THE SO(10) MODEL * Few Generalities on the Orthogonal Groups * The SO(10) Gauge Interactions * Patterns of Symmetry Breaking in the SO(10) Model * The Fermion Mass Spectrum * The Question of the Neutrino Mass * PHENOMENOLOGY OF THE INTERMEDIATE MASS SCALES * Renormalization Group Equations in the Presence of IMS * MI and MX in IMS models * Higgs Contributions to the β-Functions * Phenomenological Consequences of IMS * A GENERAL OUTLOOK ON GUTs * General Constraints on GUTs * Major Unsolved Questions in GUTs * Bibliography * References

  19. Grand unification through gravitational effects

    SciTech Connect

    Calmet, Xavier; Hsu, Stephen D. H.; Reeb, David

    2010-02-01

    We systematically study the unification of gauge couplings in the presence of (one or more) effective dimension-5 operators cHG{sub {mu}{nu}G}{sup {mu}{nu}/}4M{sub pl}, induced into the grand unified theory by gravitational interactions at the Planck scale. These operators alter the usual condition for gauge-coupling unification, which can, depending on the Higgs content H and vacuum expectation value, result in unification at scales M{sub X} significantly different than naively expected. We find nonsupersymmetric models of SU(5) and SO(10) unification, with natural Wilson coefficients c, that easily satisfy the constraints from proton decay. Furthermore, gauge-coupling unification at scales as high as the Planck scale seems feasible, possibly hinting at simultaneous unification of gauge and gravitational interactions. In the Appendix we work out the group theoretical aspects of this scenario for SU(5) and SO(10) unified groups in detail; this material is also relevant in the analysis of nonuniversal gaugino masses obtained from supergravity.

  20. Supersymmetry and supergravity: Phenomenology and grand unification

    SciTech Connect

    Arnowitt, R. |; Nath, P.

    1993-12-31

    A survey is given of supersymmetry and supergravity and their phenomenology. Some of the topics discussed are the basic ideas of global supersymmetry, the minimal supersymmetric Standard Model (MSSM) and its phenomenology, the basic ideas of local supersymmetry (supergravity), grand unification, supersymmetry breaking in supergravity grand unified models, radiative breaking of SU(2) {times} U(1), proton decay, cosmological constraints, and predictions of supergravity grand unified models. While the number of detailed derivations are necessarily limited, a sufficient number of results are given so that a reader can get a working knowledge of this field.