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Sample records for grande embayment texas

  1. Stratigraphy and sedimentology of Kincaid Formation, Midway Group (Paleocene), Upper Rio Grande Embayment, Texas

    SciTech Connect

    Roy, E.C. Jr.

    1984-09-01

    Sedimentary rocks of the Kincaid Formation crop out along the northern and western edges of the Rio Grande Embayment. Siltstones are exposed at the type locality of the Kincaid Formation along the Frio River in Uvalde County, Texas. On the east and south, the Kincaid Formation changes facies to richly fossiliferous carbonate rocks; however, basinward, it grades into a shale facies that contains interbedded units of fine-grained sandstone. At the type locality of the Kincaid Formation, approximately 30 ft (9 m) of massive siltstone grades upward into a very silty limestone unit. Bedding is poorly defined throughout the section, largely the result of intensive bioturbation. The grain size of the siltstone increases upward, ranging from medium to coarse. Clay content in the siltstone decreases upward as the amount of calcareous material increases. The upper 4-6 ft (1.2-1.8 m) may actually be considered a silty limestone. A dramatic facies change is present along the outcrop both east and south of the type section. To the east, the Kincaid Formation is composed of glauconitic and highly fossiliferous limestone. The siltstone present at the type locality thins eastward and is absent less than 20 mi (32 km) away. Eighty miles (130 km) to the south, along the Rio Grande River, approximately 45 ft (14 m) of limestone and shale comprise the Kincaid Formation. These early Paleocene sediments are interpreted to be shallow marine in origin. The siltstone represents a shallow sublittoral shoreface environment whereas the limestones on the east and south were deposited in shallow nearshore environments beyond the reach of clastic deposition.

  2. 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.

  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 time,…

  4. Hematozoan parasites of Rio Grande wild turkeys from southern Texas.

    PubMed

    Castle, M D; Christensen, B M; Rocke, T 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 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 in C. pipiens and C. tarsalis.

  5. 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.

  6. Constraints and opportunities for ecological restoration in the Rio Grande Valley, Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are few areas in the United States that have experienced a more precipitous growth than the Lower Rio Grande Valley (RGV) in south Texas, where human populations have almost doubled in the last 20 years. This growth is matched with a rapid proliferation of built environments that is often asso...

  7. 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,…

  8. Isolation of bacteria from cotton bolls in the Texas Coastal Bend and Rio Grande Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boll rots have caused a reduction in yield, lint quality, and increased contaminated seed. During 2011 and 2012 field surveys were conducted throughout the Texas Coastal Bend and Rio Grande Valley to determine incidence of cotton boll rot. A variety trial was conducted using the top five varieties...

  9. 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,…

  10. The Role of Farm Labor Market Institutions in the Lower Rio Grande Valley of Texas.

    ERIC Educational Resources Information Center

    Miller, Paul B.

    The objectives of this pilot study were to study the operation of the farm labor market in the Lower Rio Grande Valley of Texas, to analyze the functions of the labor market institutions in the Valley, and to formulate a series of policy recommendations to assist in relieving the short and long run problems of both farm workers and employers.…

  11. 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…

  12. 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.

  13. 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.

  14. Infectious disease survey of Rio Grande wild turkeys in the Edwards Plateau of Texas.

    PubMed

    Peterson, Markus J; Aguirre, Raymond; Ferro, Pamela J; Jones, Dustin A; Lawyer, Tim A; Peterson, M Nils; Silvy, Nova J

    2002-10-01

    State wildlife agencies have translocated thousands of wild turkeys (Meleagris gallopavo) since the 1930s to reestablish this species. Because of threats to the domestic poultry industry and wild birds, screening for selected infectious agents has become routine since the early 1980s. One of the principal sources for Rio Grande wild turkeys (M. gallopavo intermedia) for translocation purposes was the Edwards Plateau of Texas (USA). Unfortunately, turkey abundance has declined in the southern Edwards Plateau since the late 1970s. Surprisingly few studies have addressed wild turkeys in this region, perhaps reflecting its status as the heart of Rio Grande turkey range. We surveyed 70 free-living Rio Grande wild turkeys from Bandera and Kerr counties, Texas, for evidence of exposure to Salmonella typhimurium, S. pullorum, Mycoplasma gallisepticum, M. meleagridis, M. synoviae, Chlamydophila psittaci, and the avian influenza, Newcastle disease, turkey corona, and reticuloendotheliosis viruses. Of these, 80% (56) were seropositive for both M. gallisepticum and M. synoviae on the serum plate antigen test. Ten of these individuals (14% of total) were positive for M. synoviae by hemagglutination inhibition testing. All other serologic tests were negative. Two adult females sampled in Kerr County, whose body mass was significantly less than that of other adult females trapped in the area, tested positive for reticuloendotheliosis virus (REV) proviral DNA on polymerase chain reaction. Reticuloendotheliosis virus was isolated from one of these individuals. The pathogenesis, transmission, and/or population-level influences of M. gallisepticum, M. synoviae, and REV in Rio Grande wild turkeys deserves further study.

  15. Insecticide susceptibility of Aedes aegypti and Aedes albopictus in the Lower Rio Grande Valley of Texas and Mexico.

    PubMed

    Sames, W J; Bueno, R; Hayes, J; Olson, J K

    1996-09-01

    In response to a potential dengue fever outbreak in south Texas during 1995, the susceptibilities of Aedes aegypti and Aedes albopictus to commonly used mosquito adulticides were assessed. Larvae collected from the Lower Rio Grande Valley of Texas and Mexico were reared to adults and tested against susceptible laboratory strains at Texas A&M University. Resistance ratios at both the LC50 and LC95 rates were all less than 10, indicating that adult populations of both species are still susceptible to malathion, chlorpyrifos, resmethrin, and permethrin.

  16. Historical changes in streamflows, channel morphology, and riparian vegetation of the Rio Grande downstream of Brownsville, Texas

    USGS Publications Warehouse

    Moring, J. Bruce; Setser, Rita

    2000-01-01

    The Rio GrandefRio Bravo drains an area of more than 440,300 square kilometers of Mexico and southwestern United States (Bartlett. 1984). The Rio Grande flows for 3,000 kilometers from its headwaters in the San Juan Mountains of southern Colorado to the Gulf of Mexico downstream of Brownsville, Texas. The "Rio," as it is often called, drains the southern Rocky Mountains of Colorado and northern New Mexico; the vast Chihuahuan Desert of southern New Mexico, northern Mexico, and southwestern Texas; ami the subtropical lower valley of southern Texas (fig. I).

  17. 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.

  18. 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…

  19. 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...

  20. School and Public Youth Librarians as Health Information Gatekeepers: Research from the Lower Rio Grande Valley of Texas

    ERIC Educational Resources Information Center

    Lukenbill, Bill; Immroth, Barbara

    2009-01-01

    This study investigated how school and public librarians can become better disseminators of health information and improve health information literacy in small and rural communities in a selected research area. We used the Lower Rio Grande Valley of Texas as our study area, composed of the economically depressed Cameron, Hidalgo, Starr, and…

  1. Susceptibility of redbanded and conchuela stink bugs from the Texas Lower Rio Grande Valley to organophosphate and pyrethroid insecticides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the susceptibility of 2 stink bug species, red banded stink bug (RBSB), Piezodorus guildinii, (Westwood) and conchuela stinkbug, Chlorochroa ligata (Say) collected in the Texas Lower Rio Grande Valley to selected pyrethroid and organophosphate technical grade insecticides. The adult glass ...

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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...

  17. 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. Contributing to the…

  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. 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.

  20. Dengue vectors, human activity, and dengue virus transmission potential in the lower Rio Grande Valley, Texas, United States.

    PubMed

    Vitek, Christopher J; Gutierrez, Joann A; Dirrigl, Frank J

    2014-09-01

    Dengue virus is an emerging disease of concern in the Americas. Recent outbreaks in Florida highlight the potential for the virus to return to the United States. The Lower Rio Grande Valley region of Texas directly borders Mexico, and has experienced dengue transmission in the past concurrent with outbreaks in Mexico along the border region. We examined the potential for dengue virus transmission by examining the vectors in the region, as well as assessing human behavior. We further hypothesized that dengue vector abundance would influence human behavior. Two dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), were found in the region in high abundance. More mosquitoes were collected in rural sites and sites with high vegetation. Of the two species, only Ae. albopictus showed any significant habitat preferences, being more common in rural site. While there was no correlation between human behavior and mosquito abundance, the results support a significant correlation between knowledge of mosquitoes and dengue virus and behavioral practices that might reduce risk of disease transmission. Dengue risk may be higher in certain regions of the Lower Rio Grande Valley based on socioeconomic conditions, specifically in economically poor regions such as the undeveloped colonias found in the region. Because of the proximity of this region to an area with endemic dengue, continued surveillance and risk assessment is suggested.

  1. 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...

  2. 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.

  3. 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

  4. 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

  5. Mental health screening at temporary military health clinics in low income Hispanic communities within the Rio Grande Valley of Texas.

    PubMed

    Morecook, Robert; Greenstone, James L; Hays, J Ray

    2011-01-01

    Behavioral and mental health problems are not always considered in temporary medical clinics nor are instruments readily available to provide medical practitioners in these settings with information relevant to mental health conditions. This study provided preliminary data on the utility of the Mini Mental Screen in temporary military medical clinics in the Texas Rio Grande Valley. This instrument was administered to individuals who may have behavioral or mental health problems. In a sample of mostly Hispanic patients (N = 75) seen at a temporary medical clinic, 12% were at significant risk of mental health problems, with an additional 9% at moderate risk using published cut-off scores for the risk of such problems. The results for each patient were provided to a medical practitioner who further evaluated the risk, treated the problem, or made a referral. When asked, three of four medical practitioners found that screening data was helpful in their work with patients. One practitioner was concerned that the screening instrument might have too high a false positive rate to be useful. Cultural issues of openness about mental health and behavioral problems need to be considered in such settings.

  6. 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

    ... Texas Valley Citrus Committee (Committee) for the 2012-13 and subsequent fiscal periods from $0.14 to $0... price for Texas citrus during the 2010-11 season was around $11.30 per box and total shipments were near... available information, approximately 60 percent of Texas citrus handlers could be considered...

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 76 FR 49381 - Oranges and Grapefruit Grown in Lower Rio Grande Valley in Texas; Increased Assessment Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ... Valley Citrus Committee (Committee) for the 2011-12 and subsequent fiscal periods from $0.12 to $0.14 per...' budget, the Texas Department of Agriculture requested the citrus industry's assistance in funding a... annual receipts are less than $7,000,000. An updated Texas citrus industry profile shows that 6 of the...

  15. 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

  16. Aquifer tests in the flood-plain alluvium and Santa Fe group at the Rio Grande near Canutillo, El Paso County, Texas

    USGS Publications Warehouse

    Nickerson, Edward L.

    1989-01-01

    An aquifer system consisting of the Rio Grande flood-plain alluvium and Santa Fe Group underlying the southern Mesilla Valley in Dona Ana County, New Mexico and El Paso County, Texas has become an important source of water for both municipal and agricultural uses. Determination of aquifer properties is essential in order to evaluate groundwater potential for increasing water demand and potential streamflow depletion of the Rio Grande due to groundwater development. The aquifer system at the Canutillo well field hydrologic section was divided into a shallow, intermediate, and deep zone based on geohydrologic characteristics. Aquifer properties of specific zones at the test site were determined from a series of multiple-well aquifer tests conducted from December 3, 1985 through January 20, 1986. The Rio Grande is hydraulically connected to the shallow flood-plain alluvium. Water generally occurs within the shallow zone under unconfined conditions, within the intermediate zone under semiconfined conditions, and within the deep zone under confined conditions. (USGS)

  17. 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.

  18. 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...

  19. 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...

  20. 76 FR 61249 - Oranges and Grapefruit Grown in Lower Rio Grande Valley in Texas; Increased Assessment Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... this action was published in the Federal Register on August 10, 2011 (76 FR 49381). Copies of the... increases the assessment rate established for the Texas Valley Citrus Committee (Committee) for the 2011-12... Agriculture requested the citrus industry's assistance in funding a Mexican fruit fly trapping program,...

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Population dynamics of Bemisia argentifolii (Homoptera: Aleyrodidae) on spring collard and relationship to yield in the lower Rio Grande Valley of Texas.

    PubMed

    Liu, T X

    2000-06-01

    Seasonal population dynamics of the silverleaf whitefly, Bemisia argentifolii Bellows & Perring [formerly known as the sweetpotato whitefly, B. tabaci (Gennadius) Biotype "B"], was investigated on collard (Brassica oleracea L. variety acephala) during spring 1998 and 1999 in the Lower Rio Grande Valley of Texas. Yield loss caused by whitefly was determined by using insecticides to suppress whitefly populations to a low level. Although B. argentifolii populations of adults and immatures fluctuated greatly from April to June during the two seasons, the relative values were similar. Adult whiteflies first appeared on the plants in early April, increased rapidly within the month, peaked in May, and declined at the end of the season in early or mid-June. Whitefly eggs appeared on plants soon after adults were found, but high numbers of eggs were observed on foliage until late May 1998 and mid- and late May 1999. Nymphs and pupae increased slowly before June 1998 and increased early in May 1999. Whitefly population levels appeared to be positively associated with the availability and the growth of host plants until plant maturation, afterward being negatively related with plant quality in the late season. Temperature, rainfall, and natural enemies were not key factors in regulating population dynamics during the two seasons. Collard plants with heavy infestations of whiteflies were unmarketable because of the damage caused by honeydew and sooty mold on the foliage. Application of a combination of fenpropathrin (Danitol) and acephate (Orthene) not only significantly reduced the whitefly infestation levels but also reduced plant foliar damage, resulting in marketable foliage with six to seven times greater yield and higher quality compared with the untreated plants.

  13. 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

  14. Noise Analysis of the Northern Mississippi Embayment

    NASA Astrophysics Data System (ADS)

    Oldham, H. R.; DeShon, H. R.; Langston, C. A.; Horton, S.

    2014-12-01

    The Northern Embayment Lithosphere Experiment (NELE) is an EarthScope experiment designed to examine tectonic processes and lithospheric structure in the northern Mississippi embayment. The embayment is an intracontinental sedimentary basin filled with up to 1.5 km of unconsolidated Upper Cretaceous and younger sediments. The seismic experiment consists of four consecutive six-month deployments (September 2011 - October 2013) of broadband stations deployed to densify the Transportable Array (TA) grid and a single two-year deployment (July 2013 - June 2015) of 51 broadband seismometers along three linear profiles with an average station spacing of 20 km. Like the TA, the six-month stations were sampled at 40 Hz while the two-year stations are sampled at 100 Hz. To examine station quality and noise levels at each station, we have calculated probability density functions of power spectral densities (PDFPSDs) on all three components and compared to theoretical noise models. We use these calculations to examine how the noise profile changes across the embayment as a function of sediment thickness, sensor type, and installation technique. Preliminary observations on the 98 TA and 11 six-month NELE stations show that inside the embayment noise levels at periods between ~0.3 - 1.0 seconds (1 - 3 Hz) exceed the theoretical high noise model, and that many stations inside the embayment show a bifurcated signal at the same periods. Potential causes for the bifurcation, such as anthropogenic noise, local earthquakes, sediment variation and reverberations, and sensor/installation effects, will be discussed. Features observed in the noise catalog for all TA and NELE stations will be presented.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

    The total number and number of types of mesohabitats were larger during low flows compared to intermediate flows, and larger during intermediate flows compared to high flows. Decreases in streamflow typically led to increases in channel complexity in terms of the number of different types and total number of mesohabitats present. The total wetted area increased and the number of mesohabitat types generally decreased as streamflow increased. At all four sites, the smallest depths and velocities were generally measured during low flow and the largest depths and velocities at high flow. Specific conductance was relatively consistent between the Contrabando and Santa Elena sites, the two most upstream sites. Specific conductance decreased appreciably between the Santa Elena site and the Rio Grande Village, and decreased slightly between the Rio Grande Village site and the Stillwell Crossing site. Specific-conductance values within and among mesohabitat types at a given site were relatively consistent. The pH values measured within and among mesohabitat types also were relatively consistent at all four sites. Median dissolved oxygen concentrations were relatively consistent between the Contrabando and Santa Elena sites (8.34 and 8.54 milligrams per liter [mg/L], respectively) but decreased along the stretch of river between the Santa Elena and Rio Grande Village sites to 7.31 mg/L, possibly because of small dissolved oxygen concentrations associated with contributions from springs between the Santa Elena and Rio Grande Village sites. Dissolved oxygen concentrations increased substantially between the Rio Grande Village and Stillwell Crossing sites to 10.06 mg/L. Mesohabitat water temperatures were generally highest in mesohabitats co

  2. 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...

  3. 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

  4. 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.

  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. 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

  8. 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

  9. 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.

  10. 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

  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. PMID:27293626

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

    PubMed Central

    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. PMID:27293626

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; occurrence and distribution of selected pesticides and nutrients at selected surface-water sites in the Mesilla Valley, 1994-95

    USGS Publications Warehouse

    Healy, D.F.

    1996-01-01

    The Rio Grande Valley study unit of the U.S. Geological Survey National Water-Quality Assessment Program conducted a two-phase synoptic study of the occurrence and distribution of pesticides and nutrients in the surface water of the Mesilla Valley, New Mexico and Texas. Phase one, conducted in April-May 1994 during the high-flow irrigation season, consisted of a 6-week time- series sampling event during which 17 water-column samples were collected at 3 main-stem sites on the Rio Grande and a synoptic irrigation-run sampling event during which 19 water-column samples were collected at 7 main-stem sites, 10 drain sites, and 2 sites at the discharges of wastewater-treatment plants. Three samples are included in both the time-series and irrigation-run events. Phase two, conducted in January 1995 during the low-flow non-irrigation season, consisted of a non-irrigation synoptic sampling event during which 18 water-column samples were collected at seven main-stem sites, nine drain sites, and two sites at the discharges of wastewater-treatment plants and a bed- material sampling event during which 6 bed-material samples were collected at six sites near the mouths of drains that discharge to the Rio Grande. The 51 water-column samples were analyzed for 78 pesticides and metabolites and 8 nutrients along with other constituents. The six bed-material samples were analyzed for 21 pesticides and metabolites, gross polychlorinated biphenyls, and gross polychlorinated naphthalenes. The presence of dissolved pesticides in the surface water of the Mesilla Valley is erratic. A total of 100 detections of 17 different pesticides were detected in 44 of the water-column samples. As many as 38 percent of these detections may be attributed to pesticide use upstream from the valley or to nonagricultural pesticide use within the valley. There were 29 detections of 10 different pesticides in 17 samples during the irrigation run and 41 detections of 13 pesticides in 16 samples during the non

  18. 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.

  19. Nearshore sandbar rotation at single-barred embayed beaches

    NASA Astrophysics Data System (ADS)

    Blossier, B.; Bryan, K. R.; Daly, C. J.; Winter, C.

    2016-04-01

    The location of a shore-parallel nearshore sandbar derived from 7 years of video imagery data at the single-barred embayed Tairua Beach (NZ) is investigated to assess the contribution of barline rotation to the overall morphodynamics of sandbars in embayed environments and to characterize the process of rotation in relation to external conditions. Rotation induces cross-shore barline variations at the embayment extremities on the order of magnitude of those induced by alongshore uniform cross-shore migration of the bar. Two semiempirical models have been developed to relate the barline cross-shore migration and rotation to external wave forcing conditions. The rotation model is directly derived from the cross-shore migration model. Therefore, its formulation advocates for a primary role of cross-shore processes in the rotation of sandbars at embayed beaches. The orientation evolves toward an equilibrium angle directly related to the alongshore wave energy gradient due to two different mechanisms. Either the bar extremities migrate in opposite directions with no overall cross-shore bar migration (pivotal rotation) or the rotation relates to an overall migration of the barline which is not uniform along the beach (migration-driven rotation). Migration and rotation characteristic response times are similar, ranging from 10 to 30 days for mild and energetic wave conditions and above 200 days during very calm conditions or when the bar is located far offshore.

  20. 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.

  1. 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.

  2. 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.

  3. Salinity variations and chemical compositions of waters in the Frio Formation, Texas Gulf Coast. Annual report

    SciTech Connect

    Morton, R.A.; Garrett, C.M. Jr.; Posey, J.S.; Han, J.H.; Jirik, L.A.

    1981-11-01

    Waters produced from sandstone reservoirs of the deep Frio Formation exhibit spatial variations in chemical composition that roughly coincide with the major tectonic elements (Houston and Rio Grande Embayments, San Marcos Arch) and corresponding depositional systems (Houston and Norias deltas, Greta-Carancahua barrier/strandplain system) that were respectively active along the upper, lower, and middle Texas Coast during Frio deposition. Within an area, salinities are usually depth dependent, and primary trends closely correspond to pore pressure gradients and thermal gradients. Where data are available (mainly in Brazoria County) the increases in TDS and calcium with depth coincide with the zone of albitization, smectite-illite transition, and calcite decrease in shales. Waters have fairly uniform salinities when produced from the same sandstone reservoir within a fault block or adjacent fault blocks with minor displacement. In contrast, stratigraphically equivalent sandstones separated by faults with large displacement usually yield waters with substantially different salinities owing to the markedly different thermal and pressure gradients across the faults that act as barriers to fluid movement.

  4. 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.…

  5. Substance Abuse in the Rio Grande Valley.

    ERIC Educational Resources Information Center

    Zavaleta, Anthony N.

    1979-01-01

    In the Mexican American barrios of Texas' Lower Rio Grande Valley, existence is complicated by the interactive forces of culture, society, and economy. These three factors act in unison to create an etiology of alcohol and drug use and abuse which is poorly understood by persons outside the barrio's grasp. (Author/NQ)

  6. Youth Voice and the Llano Grande Center

    ERIC Educational Resources Information Center

    Guajardo, Francisco; Perez, Delia; Guajardo, Miguel A.; Davila, Eric; Ozuna, Juan; Saenz, Maribel; Casaperalta, Nadia

    2006-01-01

    The Llano Grande Center is a non-profit education and community development organization founded in the mid-1990s by youth and teachers out of a public high school classroom in a rural South Texas (USA) community. The Center was created, in large part, to cultivate youth voices as important elements of curriculum development and teacher training…

  7. Grand Canyon

    Atmospheric Science Data Center

    2014-05-15

    ... Monument on the right. Meteor Crater appears as a small dark depression with a brighter rim, and is just visible along the upper right-hand ... Grand Canyon location:  United States region:  Western United States Order:  ...

  8. 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.

  9. Significant reserve additions from oligocene Hackberry Sands utilizing 3-D seismic, upper Texas and Louisiana Gulf Coast

    SciTech Connect

    Zamboras, R.L.

    1995-10-01

    The Oligocene Hackberry sands of the Hackberry Embayment represent a complex and elusive exploration target. 3-D seismic evaluation along the headward erosional limits of the embayment provides a reconstructive framework of tectonic and sedimentation patterns which facilitate hydrocarbon exploration. The 3-D seismic along the Orange County, Texas portion of the Oligocene Hackberry trend indicates: (1) similarities of Hackberry structural and depositional setting to that of the underlying Eocene Yegua Formation; (2) four distinct cyclical sedimentation episodes associated with basin floor slump faulting: (3) the usefulness of seismic attributes as direct hydrocarbon indicators, and (4) the potential for significant oil and gas reserves additions in a mature trend. The Hackberry embayment represents a microcosm of the basin structural and depositional processes. Utilizing 3-D seismic to lower risk and finding cost will renew interest in trends such as the Hackberry of the Upper Texas-Louisiana Gulf Coast.

  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. Two-dimensional water quality modeling of Town Creek embayment on Guntersville Reservoir

    SciTech Connect

    Bender, M.D.; Shiao, Ming C.; Hauser, G.E. . Engineering Lab.); Butkus, S.R. . Water Quality Dept.)

    1990-09-01

    TVA investigated water quality of Town Creek embayment using a branched two-dimensional model of Guntersville Reservoir. Simulation results were compared in terms of algal biomass, nutrient concentrations, and volume of embayment with depleted dissolved oxygen. Stratification and flushing play a significant role in the embayment water quality. Storms introduce large loadings of organics, nutrients, and suspended solids. Dissolved oxygen depletion is most severe after storms followed by low flow that fails to flush the embayment. Embayment water quality responses to potential animal waste and erosion controls were explored. Modeling indicated animal waste controls were much more cost-effective than erosion controls. Erosion controls will decrease embayment suspended solids and thereby increase algal biomass due to greater light penetration. 29 refs., 16 figs., 4 tabs.

  12. 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

  13. 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…

  14. 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.

  15. Modes of embayed beach dynamics: analysis reveals emergent timescales

    NASA Astrophysics Data System (ADS)

    Murray, K. T.; Murray, A.; Limber, P. W.; Ells, K. D.

    2013-12-01

    Embayed beaches, or beaches positioned between rocky headlands, exhibit morphologic changes over many length and time scales. Beach sediment is transported as a result of the day-to-day wave forcing, causing patterns of erosion and accretion. We use the Rocky Coastline Evolution Model (RCEM) to investigate how patterns of shoreline change depend on wave climate (the distribution of wave-approach angles) and beach characteristics. Measuring changes in beach width through time allows us to track the evolution of the shape of the beach and the movement of sand within it. By using Principle Component Analysis (PCA), these changes can be categorized into modes, where the first few modes explain the majority of the variation in the time series. We analyze these modes and how they vary as a function of wave climate and headland/bay aspect ratio. In the purposefully simple RCEM, sediment transport is wave-driven and affected by wave shadowing behind the headlands. The rock elements in our model experiments (including the headlands) are fixed and unerodable so that this analysis can focus purely on sand dynamics between the headlands, without a sand contribution from the headlands or cliffs behind the beach. The wave climate is characterized by dictating the percentage of offshore waves arriving from the left and the percentage of waves arriving from high angles (very oblique to the coastline orientation). A high-angle dominated wave climate tends to amplify coastline perturbations, whereas a lower-angle wave climate is diffusive. By changing the headland/bay aspect ratio and wave climate, we can perform PCA analysis of generalized embayed beaches with differing anatomy and wave climate forcings. Previous work using PCA analysis of embayed beaches focused on specific locations and shorter timescales (<30 years; Short and Trembanis, 2004). By using the RCEM, we can more broadly characterize beach dynamics over longer timescales. The first two PCA modes, which explain a

  16. 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

  17. 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%.

  18. 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%.

  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. 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. PMID:25882229

  1. 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.

  2. 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.

  3. Mathematical modeling of stormwater pollution in a tidal embayment

    SciTech Connect

    Najjar, K.F.

    1989-01-01

    It has been recognized for many years that stormwater runoff provides a transport mechanism for non-point pollutants into the nation's waterways. As more watershed areas continue to urbanize, greater increases in pollutant loadings will continue to impact the water quality of the receiving water bodies. In many instances, the pollutant impact exceeds the assimilative capacity of the receiving water. To estimate the potential impacts of stormwater pollution, mathematical models are constructed. In this dissertation, mathematical models have been constructed to estimate the non-point pollutant loadings from an urbanizing area as well as to model the assimilative capacity of the receiving tidal embayment system. The models are capable of simulating the hydrologic aspects as well as the water quality cycles of the system as a function of urbanization. In determining the response of the receiving water system to stormwater loadings, the change in receiving water quality is modeled spatially as well as temporally. The overall model is composed of three subsystem models: a stormwater model, a hydrodynamic tidal model, and a receiving water quality model. Construction of the stormwater model is based on STORM (Storage, Treatment, Overflow, Runoff Model) by the US Army Corps of Engineers. A ground water component to the model has been added to adjust the model for application to the study area, Lakes Bay, New Jersey. The tidal model is developed from a pseudo two-dimensional approach. The methodology utilizes the link-node concept to simulate the embayment system. Solutions to equations of motion and continuity are solved using a finite difference method. The receiving water quality model is a two-dimensional time variable water quality model which is based in a finite segment approach.

  4. 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.

  5. 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.

  6. 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

  7. 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...

  8. 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

  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. 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.

  11. 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.

  12. 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.

  13. 46 CFR 7.105 - Marquesas Keys, FL to Rio Grande, TX.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the seaward limits of the territorial sea (as defined in 33 CFR 2.22(a)(1)) to Rio Grande, Texas at... 46 Shipping 1 2011-10-01 2011-10-01 false Marquesas Keys, FL to Rio Grande, TX. 7.105 Section 7... LINES Gulf Coast § 7.105 Marquesas Keys, FL to Rio Grande, TX. A line drawn from Marquesas Keys,...

  14. 46 CFR 7.105 - Marquesas Keys, FL to Rio Grande, TX.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the seaward limits of the territorial sea (as defined in 33 CFR 2.22(a)(1)) to Rio Grande, Texas at... 46 Shipping 1 2010-10-01 2010-10-01 false Marquesas Keys, FL to Rio Grande, TX. 7.105 Section 7... LINES Gulf Coast § 7.105 Marquesas Keys, FL to Rio Grande, TX. A line drawn from Marquesas Keys,...

  15. 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.

  16. Late Quaternary depositional history of the Albemarle Embayment, NC

    SciTech Connect

    Riggs, S.R.; Klingman, C.R.; Wyrick, R.A. . Dept. of Geology)

    1993-03-01

    The depositional history of Albemarle Embayment documents deep fluvial incisement by the Roanoke River system during glacial episodes and subsequent infilling by fluvial-estuarine-barrier island sediment sequences during interglacial transgressions. Unraveling the Holocene time slice will help reconstruct complex Quaternary records of multiple incisement and backfilling. A network of drill holes, vibracores, and seismic data suggest a four-phase infill history over the last 12,000 years. (1) Lower Roanoke River: (a) Bedload-charged, braided fluvial systems deposited basal sequences of sand and gravel prior to [approximately]5,000 BP. (b) Aggradational, swamp-forest floodplains developed [approximately]5,000 BP and bound the modern incised channels characterized by minimal bedload sedimentation. (2) Albemarle sound: (a) In the central basin, the basal channel sand sequence is overlain by an open estuarine, highly interlaminated sand and mud sequence that accumulated between [approximately]12,000 BP and [approximately]2,000 BP. (b) Depositional patterns within this unit suggest multiple oscillations of Holocene sea level that caused channel reincisement and subsequent backfilling. (c) Present estuarine marsh sedimentation began in protected coastal areas [approximately]5,000 BP. (3) Outer banks: (a) Barrier islands first influenced sedimentation in the area after [approximately]5,000 BP producing a semi-enclosed Albemarle Sound. (b) Deposition within the central basin shifted to uniform organic-rich muds that grade eastward into overwash and inlet sands. (4) Modern man: (a) colonial development within the drainage basins in the early 1700's AD produced a wedge of orange mud in inner Albemarle Sound. (b) Dam construction in the 1950's terminated orange mud deposition and the central basin reverted to organic-rich mud sedimentation.

  17. 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...

  18. 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

  19. 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.

  20. 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...

  1. 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...

  2. The 1968 Edcouch-Elsa High School Walkout: Chicano Student Activism in a South Texas Community

    ERIC Educational Resources Information Center

    Barrera, James B.

    2004-01-01

    A nonviolent school boycott by 192 Chicanola students in 1968 at Edcouch-Elsa high school in the Rio Grande Valley region of Deep South Texas is examined. This walkout was the first major Chicano student protest in South Texas, and was a product of the 1960s Chicano movement.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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 ...

  9. 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...

  10. 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…

  11. 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...

  12. 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, ...

  13. The crustal structure and sedimentation of the Weddell Sea embayment: implications for Gondwana reconstructions

    NASA Astrophysics Data System (ADS)

    King, E. C.

    2000-12-01

    The Weddell Sea embayment is central to reconstructions of the West Antarctic region of Gondwana. Some reconstructions represent this area as a pre-break-up component, the Filchner block, defined by the present 2000 m isobath and coastline but take no account of crustal extension and sedimentary progradation of the continental margin since break-up. Seismic refraction shows a wide, deep sedimentary basin beneath the central part of the embayment, indicating extensive rifting and stretching of continental crust during the break-up of Gondwana. This may have increased the width of the block by about 300 km. Potential field data suggest extensive progradation of sediments on the Weddell Sea continental margin. This may have moved the margin seaward between 200 and 400 km. Taken together, these modifications in the dimensions of the pre-break-up Filchner block represent between one half and one third the area of the present Weddell Sea embayment. The presence of extensive rifting is indicative that hot, thin crust was present during break-up providing further evidence that several closely spaced mantle plumes (or a single 'megaplume') impinged on the Weddell Sea sector of Gondwana in the early Jurassic. The lithospheric stretching in the embayment provided a mechanism for the rotation of the Ellsworth Mountains region during the early stages of Gondwana break-up commensurate with the paleomagnetic data.

  14. 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

  15. Growth of Mexican-American Children in South Texas.

    ERIC Educational Resources Information Center

    Guinn, Bobby; Crofts, Alfred

    Height, weight, and triceps skinfold were measured in 1,680 Mexican American children, 10 through 14 years of age, from the Lower Rio Grande Valley (LRGV) region of Texas. Study sample measurements were compared to those gathered in 1972 involving LRGV Mexican American children as well as National Center for Health Statistics (NCHS) reference data…

  16. Volcanically embayed craters on Venus: testing the catastrophic and equilibrium resurfacing models

    NASA Astrophysics Data System (ADS)

    Ivanov, M. A.; Head, J. W.

    2015-02-01

    Two major types of volcanic units, older regional plains and younger lobate plains, make up ~50% of the surface of Venus and represent different epochs of volcanism. The abundance of impact craters partially embayed from the exterior by each of these two types of units permits the testing of the key points of the model of equilibrium resurfacing. The proportion of craters embayed by the older regional plains is ~3%, which requires the typical size of a volcanic resurfacing event to be ~2700 km (~25° of angular diameter) in the framework of the equilibrium model. These event dimensions are inconsistent with the quasi-random spatial distribution of the craters. The proportion of craters embayed by younger lobate plains is 33%, which can be achieved if the characteristic size of the resurfacing event is less than ~160 km (~1.5° of angular diameter). Events of this size do not disturb the character of the spatial distribution of craters. We conclude that the style of volcanic resurfacing on Venus has changed significantly during its observable portion of the geologic history. During the global volcanic regime when regional plains were emplaced, volcanism acted in large regions and the process of formation of regional plains was more intensive than accumulation of impact craters. This led to the very small proportion of embayed craters (~3%). Later, during the network-rifting and volcanism regime (emplacement of lobate plains), volcanic sources were localized at distinctive centers, the net volcanic intensity decreased and became comparable to the rate of accumulation of craters, which resulted in much larger percentage (33%) of craters embayed by lobate plains.

  17. 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.

  18. 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.

  19. 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.

  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. 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

  3. 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

  4. 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...

  5. 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.

  6. 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…

  7. 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, "Timothy Griffith, Master…

  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. Geomorphology evolution of semi-enclosed embayment in response to human activities

    NASA Astrophysics Data System (ADS)

    Wang, Aijun; Zheng, Binxin; Ye, Xiang; Fang, Jianyong; Wang, Liang

    2016-04-01

    Coastal embayments, as an important type of coastal system, are undergoing a heavy influence by strong human activities. Tongan Bay is a typical semi-enclosed embayment adjacent to Xiamen Island, southeast China. Due to construction of the Gaoji Seawall, the Tongan Bay have occurred a heavy accretion from 1950s', and the hydrodynamic processes were changed obviously, and the fine fraction of the sediment increased. Since 2000, the Tongan Bay was experienced a series of complicated rearrangement, and hydrodynamic processes were changed again, and associated suspended sediment and bedload transport patterns were also altered, and then the new sediment distribution pattern and geomorphology structure were established correspondingly. The evolution of geomorphology in Tongan Bay is experiencing the adjustment from naturally developed pattern to artificial geomorphology types. After the complicated rearrangement, it will be fashioned into a set of new geomorphology pattern which is the net effects of physical hydrodynamic processes and human activities.

  10. 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.

  11. 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.

  12. 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.

  13. Freshwater flow into a coastal embayment: Groundwater and surface water inputs

    SciTech Connect

    Millham, N.P.; Howes, B.L.

    1994-12-01

    Freshwater discharge to a shallow coastal embayment was measured with two upland hydrologic and three embayment physical methods for 2 yr. Parallel measurements from the five methods ranged from 3,900 ({plus_minus}630) to 9,400 ({plus_minus}3,400) m{sup 3} d{sup {minus}1}, and four of the methods showed close agreement and averaged 4,800 ({plus_minus}670) m{sup 3} d{sup {minus}1}. The most precise estimate of discharge was from a chloride balance, while the best understanding of the rate and pattern of groundwater flow was from a Darcian streamtube approach. Groundwater dominated the freshwater budget, accounting for >95% of the total annual input, and was partitioned almost equally between direct seepage to embayment waters and seepage to a stream with final discharge via surface flow. Freshwater inputs decreased rapidly toward the mouth of the estuary and >80% entered into the upper half. The lack of fixed watershed boundaries resulted in large errors in both the location and area of the topographically defined watershed when compared to a watershed defined by water-table mapping. Seasonal variations were found in both the boundaries of the watershed (8%) and in groundwater discharge (6-fold) in response to changing water-table gradients due to recharge. Hydrologic alterations of the upland through the import of water and the increased recharge from impermeable surfaces led to an apparent increase in the total freshwater discharge to the embayment of nearly 50% over {open_quotes}natural{close_quotes}levels. 48 refs., 9 figs., 7 tabs.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Read Across Texas! 2002 Texas Reading Club Manual.

    ERIC Educational Resources Information Center

    Edgmon, Missy; Ferate-Soto, Paolo; Foley, Lelana; Hager, Tina; Heard, Adriana; Ingham, Donna; Lopez, Nohemi; McMahon, Dorothy; Meyer, Sally; Parrish, Leila; Rodriguez-Gibbs, Josefina; Moreyra-Torres, Maricela; Travis, Gayle; Welch, Willy

    The goal of the Texas Reading Club is to encourage the children of Texas to become library users and lifelong readers. This manual was created for the 2002 Texas Reading Club, a program of the Texas State Library and Archives Commission. The theme, "Read Across Texas!" invites children to explore the history, geography, and culture of Texas…

  3. 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.

  4. 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

  5. Temporal slip rate variability in the Lower Rhine Embayment, Northwest Europe

    NASA Astrophysics Data System (ADS)

    Gold, Ryan; Kuebler, Simon; Friedrich, Anke

    2016-04-01

    Low strain regions may be characterized by long periods of seismic quiescence, punctuated by periods of clustered earthquake activity. This type of non-periodic recurrence behavior challenges accurate seismic hazard analysis. The Lower Rhine Embayment in the German-Belgium-Netherland border region presents a unique opportunity to characterize the long-term record of faulting to evaluate the periodicity of earthquake occurrence in a low strain region. The Lower Rhine Embayment is covered by a high-resolution record of Quaternary terraces associated with the Rhine and Maas (Meuse) Rivers and their tributaries. These terraces are cut by numerous NW-trending faults and record cumulative displacements that exceed 100 m in numerous locations. In this study, we exploit this rich record of faulted fluvial terraces and find convincing evidence for temporally varying rates of Quaternary fault movement across the Lower Rhine Embayment. First, we document a significant increase in vertical fault slip rates since 700 ka, compared to the average slip rate since the start of the Quaternary using the top and base of the Main Terrace, respectively. Increases in slip rate exceed 500% along many of the faults, including the Swist/Erft, Stockheim, Viersen, Sandgewand, and Kirspenich fault systems. This increase in fault slip rate corresponds to a regional period of increased tectonic uplift of the Rhenish Massif, increased volcanism in Eifel, and incision of the Rhine River. In a second and related analysis, we synthesize terrace offset and age information from the Feldbiss fault system along the western boundary of the Lower Rhine Embayment, which transects a flight of Quaternary terraces associated with the Mass river. This analysis reveals evidence for secular variation in slip rate. In particular, we identify two periods of higher slip rate (800-400 ka and 130-100 ka), where fault slip rate exceeds the longer-term average slip rate of 0.04-0.05 mm/yr by as much as a factor of two

  6. 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

  7. 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

  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. 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...

  10. 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.

  11. 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).

  12. 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)

  13. Texas Heart Institute

    MedlinePlus

    ... 2016 Resources Texas Heart Institute Journal Scientific Publications Library & Learning Resources Resources for Physicians Fellowships & Residencies School of Perfusion Technology Please contact our Webmaster with ...

  14. 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

  15. Measurements and consequences of retention in a side embayment in a tidal river

    NASA Astrophysics Data System (ADS)

    Carr, M. L.; Rehmann, C. R.; Stoeckel, J. A.; Padilla, D. K.; Schneider, D. W.

    2004-08-01

    Embayments and tidal flow can affect the population structure of organisms, such as the zebra mussel ( Dreissena polymorpha), that have a planktonic larval phase. To examine the potential retention of larvae in embayments in tidal rivers and predict the effect of embayments on transport in the river, a field experiment was conducted and a quasi one-dimensional model was developed. Dye was injected into North Tivoli Bay, which is adjacent to the tidal portion of the Hudson River, at the start of a flood tide, and measurements of concentration, stage, and velocity over 1.5 tidal cycles were used in a mass balance to estimate the fraction of dye mass in the bay. After the first ebb, 27% of the dye remained in the bay, and during the following flood the dye that returned increased the mass in the bay to 42% of the injection mass. The field measurements were used to calibrate a quasi one-dimensional model consisting of a series of well-mixed cells with a well-mixed bay adjacent to one of the river cells. The model predicts that a small fraction of larvae would be retained in the bay by the time larvae were competent to settle, but self-recruitment may be possible due to large numbers of larvae. If enough larvae are initially produced, recruitment in the river near the spawning site is possible because the small net southward flow typical of the spawning season provides little downstream transport of the peak of the dye cloud.

  16. Understanding the Long-Term Deformation in the Mississippi Embayment: the Mississippi River Seismic Survey

    NASA Astrophysics Data System (ADS)

    Magnani, M.; McIntosh, K.; Waldron, B.; Mitchell, L.; Saustrup, S.; Towle, M.

    2008-12-01

    The Central US hosts one of the most active intraplate seismic areas in the world, the New Madrid seismic zone (NMSZ). Here the high level of historic and instrumental seismicity clashes with the subdued topography of the Mississippi embayment, minimal geodetic vectors and a puzzling lack of substantial deformation in the post Late-Cretaceous sediments. To explain this apparent paradox it has been proposed that the seismicity in the NMSZ is either 1) very young (at least in its present form), 2) episodic, or 3) migrates throughout a broad region. In order to test these hypotheses and to understand how the deformation is partitioned within the Mississippi embayment, we collected a 300 km-long high-resolution seismic reflection profile along the Mississippi river, from Helena, Arkansas to Caruthersville, Missouri. The profile images a portion of the embayment outside the area of influence of the NMSZ in a region where evidence has been mounting of a seismic source, predating the NMSZ, for which no corresponding structure has yet been identified. The seismic survey exploited the advantages of marine acqui9sition (time effective, low cost) using a 245/245 cm3 (15/15 in3) mini-GI airgun fired at 13.790MPa (2000 psi), a 24-channel 75 m-long active streamer, with 3.125 m group and 12 m nominal shot interval. The high quality data image the Cretaceous and younger sedimentary section, from the top of the Paleozoic unconformity to the Quaternary deposits. Preliminary interpretation of the dataset confirms the general deepening of the Paleozoic basement from ~800 ms at Caruthersville, to ~1 s at the southern end of Crowley's Ridge. In addition, the data reveal prominent recent deformation coincident with the Blytheville arch, the Eastern Reelfoot Rift margin and the White river Fault zone, accommodated by folding and faulting that extend from the top of the Paleozoic through the sedimentary section, and that involves the Quaternary deposits.

  17. 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.

  18. 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.

  19. 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.

  20. Eulerian and Lagrangian Measurements of Water Flow and Residence Time in a Fringing Coral Reef Embayment

    NASA Astrophysics Data System (ADS)

    Storlazzi, C. D.; Messina, A. M.; Cheriton, O. M.; Biggs, T. W.

    2014-12-01

    Hydrodynamic processes on coral reefs are important for nutrient cycling, larval dispersal, temperature variability, and understanding the impacts of terrestrial sediment, nutrients, and contaminants from adjacent impaired watersheds on coral reef ecosystems. Our goal was to understand the spatial and temporal variability in flow velocities and the associated residence time of water in the fringing coral reef flat-lined embayment of Faga'alu, on the island of Tutuila in American Samoa. To accomplish this, data from three bottom-mounted acoustic current profilers and 102 individual Lagrangian ocean surface current drifter deployments (5 drifters x 21 deployments) were combined with meteorologic data and numerical wave model results. These data and model results, collected over nine days, made it possible to evaluate the relative contribution of tidal, wind, and wave forcing on the flow patterns. The high number of drifter deployments made it possible for the velocity data to be binned into 100 m x 100 m grid cells and the resulting residence times computed for the different sets of forcing conditions. Cumulative progressive vectors calculated from the acoustic current profilers closely matched the tracks from concurrently deployed surface current drifters, showing the applicability of this hybrid Lagrangian-Eulerian measurement scheme to understand flow patterns in this geomorphically complex embayment. The bay-wide man current speeds (residence times) varied from 1-37 cm/s (2.78-0.08 hr), 1-36 cm/s (2.78-0.08 hr), and 5-64 cm/s (0.56-0.04 hr) under tidal, wind, and wave forcing, respectively; the highest speeds (shortest residence times) were measured on the outer reef flat closest to where waves were breaking on the reef crest and were slowest (longest) over the inner reef flat close to shore and deep in the embayment.

  1. 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.

  2. 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.

  3. The New Britain trench and 149° embayment, Western Solomon Sea

    NASA Astrophysics Data System (ADS)

    Tiffin, D. L.; Davies, H. L.; Honza, E.; Lock, J.; Okuda, Y.

    1987-09-01

    The western New Britain Trench contains relatively thin sediment fill in the east, compared to the west where a sequence of thick turbidites is ponded behind a basement high in the trench axis, The trench trends toward Huon Gulf, but intersects the Trobriand Trench at an acute angle at the 149° Embayment, where both trenches end. Seismic structure west of the trench is incoherent, related to incipient collision of the Indian-Australia Plate and the South Bismarck Plate. The collision suture is marked by the Markham Canyon, continuous in its upper reaches with the Ramu-Markham Fault Zone on shore.

  4. How does a tidal embayment morphodynamically react on sea level rise?

    NASA Astrophysics Data System (ADS)

    van der Wegen, Mick

    2010-05-01

    Conditions for (assumed) equilibrium in tidal embayments have been studied extensively in the past years with morphodynamic 1D models (Van Dongeren and De Vriend, 1994; Schuttelaars and de Swart, 1996, 2000; Lanzoni and Seminara, 2002) and 2D models (Hibma et al. [2003], Van der Wegen and Roelvink [2008]) Van der Wegen et al 2008). The current research addresses the impact of sea level rise on tidal embayments. Although effects of sea level rise may only become apparent after decades, the character of the embayment can change considerably. Examples are the (dis)appearance or re-allocation of intertidal flats, increased tidal resonance, shift from sediment export to import, deepening of channel area and other related (ecological) parameters. The research applies a 2D morphodynamic model (Delft3D) in an idealized environment. The model is based on the 2 D shallow water equations, the Engelund -Hansen transport formula and includes bed slope effects, drying and flooding procedures and an advanced morphodynamic update scheme (Roelvink 2006). The initial condition of the bathymetry is generated by 3000 years of morphodynamic calculations in a 80 km long and 2.5 km wide rectangular tidal embayment under constant M2 tidal forcing conditions (Van der Wegen and Roelvink [2008]). After this period sea level rise gradually developing towards a rate of 0.4 m/century is added to the boundary conditions. Model results describe development towards less intertidal area and a transition from an exporting system to a importing system. Model results are evaluated in terms of M2, M4 and M6 tidal constituents as well as against Vs/Vc (shoal volume over channel volume) versus a/h (amplitude over water depth) relationship as proposed by Friedrichs and Aubrey (1988). Although the model describes morphodynamic development in a strongly idealized environment the results can provide an excellent tool to systematically study the impact of sea level rise in tidal embayments as well as the time

  5. 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.

  6. Grand alliance HDTV

    NASA Astrophysics Data System (ADS)

    Petajan, Eric D.

    1995-12-01

    Terrestrial broadcast television in the United States has remained essentially unchanged in the last fifty years except for the addition of color and stereo sound. Today, personal computers are addressing the need for random access of high resolution images and CD quality audio. Furthermore, advances in digital video compression and digital communication technology have cleared the way toward offering high resolution video and audio services to consumers using traditional analog communications channels. In 1987, the U.S. Federal Communications Commission (FCC) chartered an advisory committee to recommend an advanced television system for the United States. From 1990 to 1992, the Advanced Television Test Center tested four all-digital systems, one analog High Definition Television (HDTV) system, and one enhancement NTSC system using broadcast and cable television environment simulators. The formation of the HDTV Grand Alliance in May of 1993 resulted from the withdrawal of the only analog HDTV system from the competition and a stalemate between the other four all- digital systems. The HDTV Grand Alliance system is composed of the best components from previously competing digital systems demonstrated to the FCC. Moving Pictures Experts Group (MPEG-2) syntax is used with novel encoding techniques to deliver a set of video scanning formats for a variety of applications. This paper describes the important features and concepts embodied in the HDTV Grand Alliance system.

  7. 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...

  8. Evidence of Ancient Rifts Beneath Texas

    NASA Astrophysics Data System (ADS)

    Irie, K.; Velasco, A. A.

    2011-12-01

    Continental rifts are defined as geological features where Earth's lithosphere is pulled away by surface expansion of the Earth. Their physiographic features include linear rift valleys associated with active volcanism. Many rifts fail to split a continent and ancient rifts that failed to split can be found by using seismic waves to image these ancient structures. Using seismic data collected by EarthScope USArray stations in Texas, we calculate teleseismic receiver functions and utilized surface wave dispersion curves to simultaneously invert for the velocity structure beneath each seismic station. With the calculated receiver functions, we generate maps to show preliminary 3-D crust/upper mantle boundary structure, the velocity ratio of P and S waves, and the S-wave velocity structure. We expect to characterize the ancient rift zones that exist in Texas and compare these results with the Rio Grande Rift in New Mexico. The goal for this comparison is to determine whether Rio Grande rift is still active or doomed to be another failed rift.

  9. Columbia Glacier, Alaska recent ice loss and its relationship to seasonal terminal embayments, thinning and glacial flow

    USGS Publications Warehouse

    Sikonia, W.G.; Post, Austin

    1980-01-01

    In 1974 the U.S. Geological Survey began an intensive investigation of the stability of Columbia Glacier, a calving tidewater galcier terminating in Columbia Bay, near Valdez, Alaska. Aerial photographs taken in 1957 and a sequence of photographs taken at about 2-month intervals since 1976, when analyzed photogrammetrically, provided detailed data on changes in Columbia Glacier 's thickness, flow rate, and terminal position. Annual embayments in the glacier 's terminus form during the summer-autumn season in most years; the size of embayments appears to be related to (1) the thickness of the glacier, and (2) the position and nature of subglacial freshwater discharge. Embayments have apparently increased in size in recent years; the largest embayments yet observed formed in 1975, 1976, 1977, and 1978. From April 1, 1977, to April 1, 1978, the total volume of ice calved was about 1.0 cubic kilometer. By January 1979 the glacier front had retreated from Heather Island. Glacier flow varies seasonally and synchronously in the lower 17 kilometers of the glacier; large accelerations occur near the terminus in response to embayment formation. Daily speed within 5 kilometers of the terminus increased from about 1.9 meters per day between 1963 and 1968 to about 2.7 meters per day between 1977 and 1978. In the lowest 15 kilometers, the glacier surface was lowered about 9 meters between 1957 and 1974, and about 13 meters between 1974 and 1978. Columbia Glacier is being reduced in mass due, in part, to recent losses caused by large embayments forming annually. If such reduction continues it will result in a drastic retreat. (USGS)

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

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

    PubMed

    Colman, John A; Masterson, John 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.

  18. The western margin of the Rio Grande rift in northern New Mexico: An aborted boundary?

    SciTech Connect

    Baldridge, W.S. Ferguson, J.F.; Barile, L.W.; Wang, Bin

    1994-12-01

    The northwestern margin of the Espanola basin, part of the Rio Grande rift in northern New Mexico, is characterized by a zone >17 km wide of oblique-slip faults that off-set upper Paleozoic and Mesozoic strata of the eastern Colorado Plateau from Eocene and younger sedimentary rocks of the rift. Along this margin, a reasonably complete section of pre- and synrift Tertiary sediments is exposed. Combined interpretations of seismic reflection, seismic refraction, gravity, and geologic data acquired along a profile perpendicular to this boundary define the geometry of faulting, possible rotation of sedimentary units, and stratigraphy of rift fill. Vertical separation on the westernmost major fault, assumed to be the bounding fault between the rift and the Colorado Plateau, is <500 m; separation on other faults in the zone is <200 m. Thus the northwestern part of the Espanola basin ({open_quotes}Abiquiu embayment{close_quotes}) is a shallow platform rather than a deep rift basin. The embayment is separated from the main Espanola basin by the east-northeast-striking Embudo transfer fault, which appears to act as the northern bounding fault of the main basin. 42 refs., 10 figs., 3 tabs.

  19. Furthering Medical Education in Texas.

    PubMed

    Varma, Surendra K; Jennings, John

    2016-02-01

    Medical education in Texas is moving in the right direction. The Texas Medical Association has been a major partner in advancing medical education initiatives. This special symposium issue on medical education examines residency training costs, the Next Accreditation System, graduate medical education in rural Texas, Texas' physician workforce needs, the current state of education reform, and efforts to retain medical graduates in Texas. PMID:26859372

  20. 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...

  1. 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.

  2. 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.

  3. NARSTO Texas Final Report

    Atmospheric Science Data Center

    2013-03-06

    Final Report for the Texas PM2.5 Sampling and Analysis Study (March 11, 1997, through March 12, 1998) ... files: Section 1: Introduction and Section 2: Sampling Network (PDF) Section 3: Data Base Structure (PDF) ...

  4. 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

  5. Mexico, New Mexico and Texas as seen from the Apollo 6 unmanned spacecraft

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Mexico, New Mexico and Texas are photographed from the Apollo 6 (Spacecraft 020/Saturn 502) unmanned space mission during its 2nd orbit of the Earth. Seen in this photograph are Deming, Palomas, Las Cruces, El Paso, Florida Mountains, East and West Portrillo Mountains, San Andres Mountains, Franklin Mountains, and Juarez Mountains and the Rio Grande River.

  6. Risk-based residential HLB/ACP survey for California, Texas and Arizona

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recent discoveries of HLB in the Los Angeles Basin and the Rio Grande Valley of Texas underscore the imminent danger of HLB spread in these two States and the urgent need for highly sensitive survey methods for early detection of new residential infections of HLB combined with rapid intervention...

  7. 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

  8. Ground-water quality data from the northern Mississippi embayment; Arkansas, Missouri, Kentucky, Tennessee, and Mississippi

    USGS Publications Warehouse

    Brahana, J.V.; Mesko, T.O.; Busby, J.F.; Kraemer, T.F.

    1985-01-01

    Groundwater quality data were collected from 42 selected wells in the McNairy-Nacatoch-Ripley and the lower Wilcox aquifers of the northern Mississippi embayment. The study is part of the Gulf Coast Regional Aquifer System Analysis (GC RASA) study; the data will be used for geochemical modeling of mineral saturation and mass transfer in the McNairy-Nacatoch-Ripley aquifer. The report contains two figures showing the location of sampling sites for each of the two aquifers, six tables of data which contain (1) well descriptions and (2) concentrations of major constituents, trace constituents, dissolved gases, stable and unstable isotopes of low mass (C, H, O, and S), and unstable isotopes of high mass (Rn, Ra, and U), and a brief documentation of the methods used for sample collection and analysis. (USGS)

  9. Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013

    NASA Astrophysics Data System (ADS)

    Mouginot, J.; Rignot, E.; Scheuchl, B.

    2014-03-01

    We combine measurements of ice velocity from Landsat feature tracking and satellite radar interferometry, and ice thickness from existing compilations to document 41 years of mass flux from the Amundsen Sea Embayment (ASE) of West Antarctica. The total ice discharge has increased by 77% since 1973. Half of the increase occurred between 2003 and 2009. Grounding-line ice speeds of Pine Island Glacier stabilized between 2009 and 2013, following a decade of rapid acceleration, but that acceleration reached far inland and occurred at a rate faster than predicted by advective processes. Flow speeds across Thwaites Glacier increased rapidly after 2006, following a decade of near-stability, leading to a 33% increase in flux between 2006 and 2013. Haynes, Smith, Pope, and Kohler Glaciers all accelerated during the entire study period. The sustained increase in ice discharge is a possible indicator of the development of a marine ice sheet instability in this part of Antarctica.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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... associated ancillary facilities in Montgomery County, Texas. Specifically, Texas Eastern proposes to...

  20. 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.

  1. 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.

  2. 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.

  3. Grand slam on cancer.

    PubMed

    Gartrell, Nanette

    2014-01-01

    A winner of 59 Grand Slam championships including a record 9 Wimbledon singles titles, Martina Navratilova is the most successful woman tennis player of the modern era. Martina was inducted into the International Tennis Hall of Fame, named "Tour Player of the Year" seven times by the Women's Tennis Association, declared "Female Athlete of the Year" by the Associated Press, and ranked one of the "Top Forty Athletes of All-Time" by Sports Illustrated. Equally accomplished off the court, Martina is an author, philanthropist, TV commentator, and activist who has dedicated her life to educating people about prejudice and stereotypes. After coming out as a lesbian in 1981, Martina became a tireless advocate of equal rights for lesbian, gay, bisexual, and transgender (LGBT) people, and she has contributed generously to the LGBT community. Martina is the author of seven books, including most recently Shape Your Self: My 6-Step Diet and Fitness Plan to Achieve the Best Shape of your Life, an inspiring guide to healthy living and personal fitness. Martina was diagnosed with breast cancer in 2010. PMID:24400624

  4. Grand slam on cancer.

    PubMed

    Gartrell, Nanette

    2014-01-01

    A winner of 59 Grand Slam championships including a record 9 Wimbledon singles titles, Martina Navratilova is the most successful woman tennis player of the modern era. Martina was inducted into the International Tennis Hall of Fame, named "Tour Player of the Year" seven times by the Women's Tennis Association, declared "Female Athlete of the Year" by the Associated Press, and ranked one of the "Top Forty Athletes of All-Time" by Sports Illustrated. Equally accomplished off the court, Martina is an author, philanthropist, TV commentator, and activist who has dedicated her life to educating people about prejudice and stereotypes. After coming out as a lesbian in 1981, Martina became a tireless advocate of equal rights for lesbian, gay, bisexual, and transgender (LGBT) people, and she has contributed generously to the LGBT community. Martina is the author of seven books, including most recently Shape Your Self: My 6-Step Diet and Fitness Plan to Achieve the Best Shape of your Life, an inspiring guide to healthy living and personal fitness. Martina was diagnosed with breast cancer in 2010.

  5. Transforming Developmental Education in Texas

    ERIC Educational Resources Information Center

    Journal of Developmental Education, 2014

    2014-01-01

    In recent years, with support from the Texas Legislature, the Texas Higher Education Coordinating Board has funded various developmental education initiatives, including research and evaluation efforts, to help Texas public institutions of higher education provide more effective programs and services to underprepared students. Based on evaluation…

  6. The Texas Ranger of Testing.

    ERIC Educational Resources Information Center

    Zlatos, Bill

    1996-01-01

    Texas takes test security seriously. Joe Lucio, the Texas Ranger of testing, investigates security breaches of the Texas Assessment of Academic Skills--a mandatory, high-stakes examination. Students cheat mainly on the test required for graduation. Educators cheat by helping test-takers. Lucio's low-key, persistent investigative style usually…

  7. Texas Almanac, 2002-2003.

    ERIC Educational Resources Information Center

    Ramos, Mary G., Ed.

    The 61st edition of the "Texas Almanac" has a reputation as the definitive source for Texas information since 1857. It contains details of the Census 2000 official population count, including statewide, county and town counts, plus an analysis of the numbers by experts at Texas's State Data Center. It includes information about politics,…

  8. 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.

  9. 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.

  10. 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.

  11. Structure of the southern Rio Grande rift from gravity interpretation

    NASA Technical Reports Server (NTRS)

    Daggett, P. H.; Keller, G. R.; Wen, C.-L.; Morgan, P.

    1986-01-01

    Regional Bouguer gravity anomalies in southern New Mexico have been analyzed by two-dimensional wave number filtering and poly-nomial trend surface analysis of the observed gravity field. A prominent, regional oval-shaped positive gravity anomaly was found to be associated with the southern Rio Grande rift. Computer modeling of three regional gravity profiles suggests that this anomaly is due to crustal thinning beneath the southern Rio Grande rift. These models indicate a 25 to 26-km minimum crustal thickness within the rift and suggest that the rift is underlain by a broad zone of anomalously low-density upper mantle. The southern terminus of the anomalous zone is approximately 50 km southwest of El Paso, Texas. A thinning of the rifted crust of 2-3 km relative to the adjacent Basin and Range province indicates an extension of about 9 percent during the formation of the modern southern Rio Grande rift. This extension estimate is consistent with estimates from other data sources. The crustal thinning and anomalous mantle is thought to result from magmatic activity related to surface volcanism and high heat flow in this area.

  12. Helminths of the ocelot from southern Texas.

    PubMed

    Pence, Danny B; Tewes, Michael E; Laack, Linda L

    2003-07-01

    In the USA, the ocelot (Leopardus pardalis) is a highly endangered felid found only in a few remaining vestiges of native thornshrub brushland in the Lower Rio Grande Valley (LRGV) of extreme southern Texas. From 1987-1998, carcasses of 15 adult ocelots that died of vehicular accidents or natural causes were examined for helminths. All cats had 1-8 (mean = 3) helminth species. All were infected with 1-101 (mean +/- SE = 32 +/- 7) Toxascaris leonina. Other helminths from these ocelots were Alaria marcianae, Brachylaima sp., Mesocestoides lineatus, Taenia rileyi, Oncicola canis, Dirofilaria immitis, Physaloptera rara, Ancylostoma tubaeformae, Cylicospirura chevreuxi, Vogeloides felis, and Metathelazia californica. Additionally, two cats had scarring of the aorta with lesions typical of those caused by Spriocerca lupi, although larval nematodes were not seen. A clinal variation in size of nearly three orders of magnitude was noted in the diplostomatid trematodes in the small intestine of one adult male ocelot. Despite the differences in size, all specimens appeared morphologically identical and were regarded as A. marcianae. Helminth prevalences and abundances, including those of potentially pathogenic species like D. immitis, were low. Although a single heartworm infection may have contributed to the death of one ocelot, helminth infections in general seemed to be of no great consequence to this endangered ocelot population. The helminth fauna of ocelots in the LRGV is reflective of that from wild felids in general; all have been reported previously from the bobcat (Lynx rufus) and mountain lion (Puma concolor) elsewhere in Texas. PMID:14567231

  13. 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.

  14. 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

  15. 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

  16. More Evidence for Young Tectonism Along the Saline River Fault Zone, Southern Mississippi Embayment

    NASA Astrophysics Data System (ADS)

    Cox, R. T.; Harris, J. B.; Hill, A. A.; Forman, S. L.; Gardner, C.; Csontos, R.

    2004-12-01

    Within the southern Mississippi embayment the 315-striking Saline River fault zone (SRFZ) was recently recognized from linear river segments, aligned epicenters, fault and fold exposures, sand blows, seismic reflection profiles, and trench investigations. In our latest work, shallow S-wave reflection profiles were acquired across the SRFZ within a sand blow field in Holocene alluvium at the southeastern limit of the mapped SRFZ. Along the central part of the SRFZ our field surveys of linear river segments subparallel to the SRFZ reveal that these segments are associated with faulting, fracturing, and folding of Eocene, late Pleistocene, and Holocene strata. In addition, we used logs of coal exploration holes to map shallow Eocene structure across the central SRFZ. In the SE of our study region, two S-wave reflection profiles (parallel and overlapping) were acquired along a 0.6 km N-S transect of the fault zone in NE Ashley County, AR. They reveal the SRFZ has a flower structure geometry with both positive and negative elements. The Eocene/Quaternary contact is clearly seen at 0.3 s (30 to 40 m depth). Several faults cut through the Quaternary section, and Quaternary and Eocene strata are folded harmonically. A fault in the overlap zone can be shown to strike 289 deg. New luminescence (IRSL) dates constrain a significant sand blow episode near this locality to between 7690 and 5725 yrs BP and a later significant episode to younger than 6845 yrs BP, consistent with previous results of middle to late Holocene sand venting here. In the central portion of the SRFZ, previous investigations of a linear river segment revealed a faulted anticline deforming alluvium younger than 720 years old. Our latest river surveys reveal that other linear river segments are associated with fractures and folds in Eocene substrate and young alluvium. Some oblique structures suggest a subsidiary strike-slip array. Shallow subsurface structure in Eocene strata mapped from coal exploration

  17. 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.

  18. 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 Heritage," gives a…

  19. 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…

  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. 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 the…

  2. 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 administrators. (MLH)

  3. 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…

  4. Trouble at Texas Southern

    ERIC Educational Resources Information Center

    Asquith, Christina

    2006-01-01

    On the night of December 4, 2004, a Texas Southern University (TSU) student named Ashley Sloan was gunned down near campus, struck in the temple by a bullet after leaving a party with her friends. The murder prompted an outpouring of accusations concerning poor campus security. For many Houstonians, the shooting raised old fears of the…

  5. 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…

  6. Texas-Oklahoma

    Atmospheric Science Data Center

    2014-05-15

    article title:  Texas-Oklahoma Border     ... important resources for farming, ranching, public drinking water, hydroelectric power, and recreation. Both originate in New Mexico and ... NASA's Goddard Space Flight Center, Greenbelt, MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science ...

  7. 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...

  8. 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 development of a…

  9. Wind powering America - Texas

    SciTech Connect

    O'Dell, K.

    2000-04-13

    This fact sheet contains a description of the wind energy resources in the state of Texas and the state's efforts to develop wind energy production, green power, and net metering programs. The fact sheet also includes a list of contacts for those interested in obtaining more information.

  10. 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

  11. Catalogue of Texas spiders.

    PubMed

    Dean, David Allen

    2016-01-01

    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

  12. Water Marketing as a Reallocative Institution in Texas

    NASA Astrophysics Data System (ADS)

    Chang, Chan; Griffin, Ronald C.

    1992-03-01

    Policy selection for guiding the allocation of water resources has long been debated among economists and policymakers. Economists have been prone to recommend water marketing on theoretical grounds, but the appraisal of realistic opportunities for employing market institutions requires analysis of actual markets. Twenty years of market activity in the Lower Rio Grande Valley of Texas are reviewed along with the historical development of water law in Texas and procedural requirements for transferring water rights. Developed data indicate active water marketing practices with significant volumes of agricultural water having been sold to municipalities. For transactions involving representative cities, estimated municipal benefits from water marketing are determined to far exceed the agricultural costs of the transfer. Attention to the unique circumstances of this region is required prior to extending results to other areas.

  13. 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.

  14. Glacial/interglacial ice-stream stability in the Weddell Sea embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Hein, Andrew S.; Fogwill, Christopher J.; Sugden, David E.; Xu, Sheng

    2011-07-01

    The resilience of the Antarctic Ice Sheet and its effect on global sea level depends on the dynamics of ice streams. Antarctic ice streams are known to be responsive to changes at the ocean interface and, as expected, most have thinned in response to ocean warming and sea-level rise since the Last Glacial Maximum (LGM). Here we provide direct and unexpected evidence that points toward the glacial/interglacial stability of the Slessor and Recovery glaciers, ice streams of the East Antarctic Ice Sheet (EAIS) which merge with the West Antarctic Ice Sheet (WAIS) to form the Filchner Ice Shelf in the Weddell Sea embayment. Cosmogenic-nuclide measurements in the Shackleton Range suggest that the Slessor and Recovery ice streams were not significantly thicker than today during the LGM. We hypothesise that the glaciers did not thicken because the grounding line was not able to migrate seaward beyond the deep Thiel/Crary Trough beneath the Filchner Ice Shelf immediately offshore. This discovery reveals how a topographic threshold can affect the dynamics of ice streams. It also reduces uncertainties on the thickness, extent and volume of the Antarctic Ice Sheet in a large but unknown sector of the Antarctic Ice Sheet; it constrains the potential sea-level rise from Antarctica; it helps explain observed anomalies in glacio-isostatic adjustment; above all it suggests that the behaviour of the Atlantic-facing Weddell Sea sector of the WAIS contrasts with that of the Pacific-facing Ross and Amundsen Sea sectors.

  15. Molecular characterization of potential microcystin-producing cyanobacteria in Lake Ontario embayments and nearshore waters.

    PubMed

    Hotto, A M; Satchwell, M F; Boyer, G L

    2007-07-01

    The distribution and genotypic variation of potential microcystin (MC) producers along the southern and eastern shores of Lake Ontario in 2001 and 2003 were examined using a suite of PCR primers. Cyanobacterial, Microcystis sp., and Microcystis-specific toxin primer sets identified shoreline distribution of cyanobacterial DNA (in 97% of the stations) and MC synthetase genes (in 50% of the stations). Sequence analysis of a partial mcyA amplicon targeting Microcystis, Anabaena, and Planktothrix species indicated that the Microcystis sp. genotype was the dominant MC genotype present and revealed a novel Microcystis-like sequence containing a 6-bp insert. Analysis of the same samples with genus-specific mcyE primers confirmed that the Microcystis sp. genotype was the dominant potential MC producer. Genotype compositions within embayments were relatively homogenous compared to those for shoreline and tributary samples. MC concentrations along the shoreline exhibited both temporal and spatial differences as evidenced by the protein phosphatase inhibition assay, at times exceeding the World Health Organization guideline value for drinking water of 1.0 microg MC-LReq liter(-1). MC genotypes are widespread along the New York State shoreline of Lake Ontario, appear to originate nearshore, and can be carried through the lake via wind and surface water current patterns.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Facies Analysis of Fahliyan Formation in North Dezful Embayment, Southwest Iran: Implications for Porosity Distribution

    NASA Astrophysics Data System (ADS)

    Sabouhi, M.; Jahani, D.; Taati Qurayem, F.; Aminzadeh, A.

    2009-04-01

    Fahliyan Formation (Neocomian) is one of the important hydrocarbon reservoirs of khami group in south west of Iran. This Formation has 332m thickness in type section and mainly consist of carbonate rocks. In this study, the Fahliyan Formation was investigated in subsurface section of AZN#B Well in the north Dezful Embayment (with281m thickness). Lower boundary of Fahliyan Formation with Garau Formation is continuous and the upper contact with Gadvan formation is conformable According to this study 13 carbonate microfacies and one shaily facies were recognized which are grouped into four facies associations(micro facies group). These facies associations present platform to basin depositional setting and are nominated as : A (Tidal-flat), B (Lagoon), C (Bar) and D (Open marine). Based on available data set including cutting samples, thin sections and well log analysis, it seems the Fahliyan Formation was deposited in a Carbonate shelf setting and the studied profile indicates the shallowest part of the platform. Secondary porosities due to dolomitization and Stylolitization played an important role in increasing reservoir quality of the formation. Other types of porosities occupied by later cementations and had no contribution in reservoir quality.

  2. Geomorphic evidence of possible tectonic activity in the Mississippi embayment of southeast Missouri

    SciTech Connect

    Steckel, P.J.

    1993-03-01

    Several distinct topographic and geomorphic features in the Mississippi Embayment of southeast Missouri may provide direct and indirect evidence of tectonic influence on surface processes. First, the Pascola bulge is an extremely subtle feature, which probably trends northwest from about Caruthersville to northeast of Kennett and may or may not be associated with the Pascola Arch. The Pascola bulge may be responsible for an abrupt change in both the direction and meander pattern of the natural channel of the Little river near Wardell; a bifurcation of the natural channel of the Little river west of Wardell; the closing off of a natural, navigable waterway between the Mississippi and St. Francis rivers (in the early 1800s); and, at least partly, the extremely inefficient Caruthersville Bend of the Mississippi River. Second, the Canalou nickpoint is an abrupt and distinct change in slope that coincides with both a series of northwest-trending surface lineaments and a southeast projection of the Black fault, located in the Paleozoic rock of the Ozark Uplift. The Canalou nickpoint may suggest a structural feature in the area west of Sikeston. Finally, a subtle yet distinctly irregular surface topography and the near obliteration of topographic expression of the natural channel of the Little River suggest that sunklands may have occurred in areas southeast of Kennett and from near Hornersville south to at least the Missouri-Arkansas state line.

  3. 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.

  4. 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...

  5. 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…

  6. 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…

  7. "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 "ganas" formation. The…

  8. 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.

  9. 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.

  10. 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.

  11. San Antonio, Texas, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This sharp, cloud free view of San Antonio, Texas (29.5N, 98.5W) illustrates the classic pattern of western cities. The city has a late nineteenth century Anglo grid pattern overlaid onto an earlier, less regular Hispanic settlement. A well marked central business district having streets laid out north/south and east/west is surrounded by blocks of suburban homes and small businesses set between the older colonial radial transportation routes.

  12. Human lead absorption -- Texas.

    PubMed

    1997-09-19

    In December 1971, the City-County Health Department in El Paso, Texas, discovered that an ore smelter in El Paso was discharging large quantities of lead and other metallic wastes into the air. Between 1969 and 1971, this smelter had released 1,116 tons of lead, 560 tons of zinc, 12 tons of cadmium, and 1.2 tons of arsenic into the atmosphere through its stacks.

  13. Libraries in Texas: MedlinePlus

    MedlinePlus

    ... this page: https://medlineplus.gov/libraries/texas.html Libraries in Texas To use the sharing features on ... Amarillo Texas Tech University Health Sciences Center Harrington Library of the Health Sciences 1400 Wallace Boulevard Amarillo, ...

  14. Thunderstorm, Texas Gulf Coast, USA

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This thunderstorm along the Texas Gulf Coast (29.0N, 95.0W), USA is seen as the trailing edge of a large cloud mass formed along the leading edge of a spring frontal system stretching northwest to southeast across the Texas Gulf Coast. This system brought extensive severe weather and flooding to parts of Texas and surrounding states. Muddy water discharging from coastal streams can be seen in the shallow Gulf of Mexico as far south as Lavaca Bay.

  15. 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.

  16. Large-Ensemble Modeling of Past Variations in West Antarctic Embayments

    NASA Astrophysics Data System (ADS)

    Pollard, D.; Deconto, R. M.

    2014-12-01

    Recent observations of thinning and retreat of the Pine Island and Thwaites Glaciers identify this sector of West Antarctica as particularly vulnerable to future climate change. To date, most future modeling of these glaciers has beenvalidated using recent and modern observations. As an alternate approach,we apply a hybrid 3-D ice sheet-shelf model to the last deglacial retreat in this sector, making use of geologic data of ice extents from ~20,000 years BP to present, both for the Amundsen Sea sector and also for the Ross and Weddellembayments.Following recent ice-sheet studies, we use Large-Ensemble statistical techniques, performing sets of ~500 to 1000 runs with varying model parameters. The model is run for the last 20 kyrs on 5 to 20-km grids spanning West Antarctica, with lateral boundary conditions from a prior continental-scale simulation. An objective score for each run is calculated using reconstructed past grounding lines, shelf extents, relative sea levels, and modern conditions. Runs are extended into the future (few millennia) with simple atmospheric and oceanic forcing. The goal is to produce calibrated probabilistic envelopes of model parameter ranges and simulated ice retreat.Preliminary results are presented for Large Ensembles with (i) Latin HyperCube sampling in high-dimensional parameter space, and (ii) dense sampling with a lower number of parameters. We focus on optimal parameter differencesbetween the 3 embayments, validation with other paleo data, contribution to meltwater pulses ~14 to 12 ka, and future projections. Most reasonable parameter combinations produce drastic future retreat into the interior Pine Island and Thwaites basins within ~2000 years, adding ~2 m to global sea-level rise.

  17. 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.

  18. 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.

  19. Evaluation of four global reanalysis products using in situ observations in the Amundsen Sea Embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Jones, R. W.; Renfrew, I. A.; Orr, A.; Webber, B. G. M.; Holland, D. M.; Lazzara, M. A.

    2016-06-01

    The glaciers within the Amundsen Sea Embayment (ASE), West Antarctica, are amongst the most rapidly retreating in Antarctica. Meteorological reanalysis products are widely used to help understand and simulate the processes causing this retreat. Here we provide an evaluation against observations of four of the latest global reanalysis products within the ASE region—the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-I), Japanese 55-year Reanalysis (JRA-55), Climate Forecast System Reanalysis (CFSR), and Modern Era Retrospective-Analysis for Research and Applications (MERRA). The observations comprise data from four automatic weather stations (AWSs), three research vessel cruises, and a new set of 38 radiosondes all within the period 2009-2014. All four reanalyses produce 2 m temperature fields that are colder than AWS observations, with the biases varying from approximately -1.8°C (ERA-I) to -6.8°C (MERRA). Over the Amundsen Sea, spatially averaged summertime biases are between -0.4°C (JRA-55) and -2.1°C (MERRA) with notably larger cold biases close to the continent (up to -6°C) in all reanalyses. All four reanalyses underestimate near-surface wind speed at high wind speeds (>15 m s-1) and exhibit dry biases and relatively large root-mean-square errors (RMSE) in specific humidity. A comparison to the radiosonde soundings shows that the cold, dry bias at the surface extends into the lower troposphere; here ERA-I and CFSR reanalyses provide the most accurate profiles. The reanalyses generally contain larger temperature and humidity biases, (and RMSE) when a temperature inversion is observed, and contain larger wind speed biases (~2 to 3 m s-1), when a low-level jet is observed.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Methane and nitrous oxide emissions from a subtropical coastal embayment (Moreton Bay, Australia).

    PubMed

    Musenze, Ronald S; Werner, Ursula; Grinham, Alistair; Udy, James; Yuan, Zhiguo

    2015-03-01

    Surface water methane (CH4) and nitrous oxide (N2O) concentrations and fluxes were investigated in two subtropical coastal embayments (Bramble Bay and Deception Bay, which are part of the greater Moreton Bay, Australia). Measurements were done at 23 stations in seven campaigns covering different seasons during 2010-2012. Water-air fluxes were estimated using the Thin Boundary Layer approach with a combination of wind and currents-based models for the estimation of the gas transfer velocities. The two bays were strong sources of both CH4 and N2O with no significant differences in the degree of saturation of both gases between them during all measurement campaigns. Both CH4 and N2O concentrations had strong temporal but minimal spatial variability in both bays. During the seven seasons, CH4 varied between 500% and 4000% saturation while N2O varied between 128 and 255% in the two bays. Average seasonal CH4 fluxes for the two bays varied between 0.5±0.2 and 6.0±1.5 mg CH4/(m2·day) while N2O varied between 0.4±0.1 and 1.6±0.6 mg N2O/(m2·day). Weighted emissions (t CO2-e) were 63%-90% N2O dominated implying that a reduction in N2O inputs and/or nitrogen availability in the bays may significantly reduce the bays' greenhouse gas (GHG) budget. Emissions data for tropical and subtropical systems is still scarce. This work found subtropical bays to be significant aquatic sources of both CH4 and N2O and puts the estimated fluxes into the global context with measurements done from other climatic regions. PMID:25766016

  5. Designing a Virtual Grand Tour

    ERIC Educational Resources Information Center

    Hansen, Per Skafte

    2004-01-01

    The Virtual Grand Tour (VGT) is a paradigm for integrating a presentation of an overview of a larger subject with the possibility of launching at any time an exploratory study of a given sub-topic. The name derives from the paradigm's emulation of those 18th-century travels intended to educate (especially) young, affluent British men; today, with…

  6. Giving a grand rounds presentation.

    PubMed

    Morrison, Laura J; Portenoy, Russell

    2010-12-01

    Giving a Grand Rounds presentation provides the hospice and palliative medicine subspecialist with the occasion to participate in a time-honored and respected event. It remains an opportunity to promote the discipline, support institutional culture change, and favorably influence the attitudes, knowledge, skills, and performance of colleagues. For those pursuing academic careers, it also is a chance to establish academic currency and develop teaching and presentation skills. In most academic settings, the format of Grand Rounds has shifted over time from a patient and problem-based discussion to a didactic, topic-focused lecture. A body of literature questions the value of this shift toward a more passive learner. Limited evidence prevents a definitive answer but many advocate for the integration of more interactive methods to improve the effectiveness of Grand Rounds. This article provides a flexible framework to guide those preparing to give a Grand Rounds and those teaching and supporting others to do so. To do this well, adult learning principles must be thoughtfully incorporated into a presentation style and method appropriate to the venue. The approach emphasizes learner-centeredness, interactive strategies, and evaluation. Room for creativity exists at every step and can add enjoyment and challenge along the way. PMID:21155643

  7. 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)

  8. 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.

  9. Hydrogeology of Webb County, Texas

    USGS Publications Warehouse

    Lambert, Rebecca B.

    2004-01-01

    Introduction: Webb 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

  10. Alongshore variability in beach planform, grain-size distribution and foredune height of an embayed beach: Shoalwater Bay, Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Weymer, B. A.; Houser, C.; Giardino, R.

    2012-12-01

    Headland-bay beaches (HBB) are common beach-types found throughout the coastlines of the world. Morphodynamics of these structurally-controlled beaches are primarily governed by geological inheritance, wave climate, tidal range and grain-size distribution, which ultimately influence sediment transport across the beach-dune system. For embayed beaches, the degree of curvature (i.e., indentation ratio) has significant implications for littoral cell circulation, which mediates both cross-shore and alongshore sediment transport. This study investigated the morphodynamic controls on longshore and cross-shore sediment transport for a macro-tidal, embayed beach in central Queensland, Australia. Freshwater Beach is a 10 km long embayed beach located in the Shoalwater Bay Training Area, ~50 km north of Yeppoon. Freshwater Beach exhibits an asymmetrical planform which is characterized by a curved "shadow zone" (adjacent to the headland), transitioning to a straight tangential segment extending to the north. The beach is subjected to a mean tidal range of 6 m and prevailing onshore-directed winds and swell from the southeast. A total of 12 topographic profiles at ~1 km spacing were taken along the entire length of the beach to characterize variation in beach slope and foredune height. Sediment samples were collected across each transect for detailed grain-size and geochemical (XRD/XRF and SEM) analysis. Additionally, ground-based LiDAR surveys were conducted along the topographic profiles and for comparison with aerial-based LiDAR surveys. Preliminary results from topographic profiles show that the largest foredunes are located in the central portion of the beach, contrary to most embayed beaches where the largest dunes are typically located downdrift of the headland. Along the exposed section, the foredunes become large (~15 m high) and are hypothesized to be supplied by onshore welded bars that act as a sediment source for the foredunes to grow. Presently the alongshore and

  11. 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.

  12. 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…

  13. CBTE: The Ayes of Texas

    ERIC Educational Resources Information Center

    Houston, W. Robert; Howsam, Robert B.

    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. This is an account of developments in Texas by two major proponents of CBTE. (Author/JF)

  14. 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…

  15. 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 higher…

  16. Tech Prep Consortia in Texas.

    ERIC Educational Resources Information Center

    Opp, Ronald D.

    The Tech Prep (TP) program is designed to provide a seamless transition for students between the high school, community college, and four-year college levels so that students can make an easier transition from school to work. In Texas, TP has developed differently from the programs of other states. Texas policy makers created a tri-agency…

  17. Grand rip and grand bang/crunch cosmological singularities

    NASA Astrophysics Data System (ADS)

    Fernández-Jambrina, L.

    2014-09-01

    The present accelerated expansion of the Universe has enriched the list of possible scenarios for its fate, singular or not. In this paper a unifying framework for analyzing such behaviors is proposed, based on generalized power and asymptotic expansions of the barotropic index w, or equivalently of the deceleration parameter q, in terms of the time coordinate. Besides well-known singular and nonsingular future behaviors, other types of strong singularities appear around the phantom divide in flat models, with features similar to those of big rip or big bang/crunch, which we have dubbed "grand rip" and "grand bang/crunch," respectively, since energy density and pressure diverge faster than t-2 in coordinate time. In addition to this, the scale factor does not admit convergent generalized power series around these singularities with a finite number of terms with negative powers.

  18. 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.

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. Economic impacts of federal policy responses to drought in the Rio Grande Basin

    NASA Astrophysics Data System (ADS)

    Ward, Frank A.; Hurd, Brian H.; Rahmani, Tarik; Gollehon, Noel

    2006-03-01

    Significant growth in the Rio Grande Basin's demand for water has stressed the region's scarce water supply. This paper presents an analysis of the impacts of severe and sustained drought and of minimum in-stream flow requirements to support endangered species in the Rio Grande watershed. These impacts are investigated by modeling the physical and institutional constraints within the Rio Grande Basin and by identifying the hydrologic and economic responses of all major water users. Water supplies, which include all major tributaries, interbasin transfers, and hydrologically connected groundwater, are represented in a yearly time step. A nonlinear programming model is developed to maximize economic benefits subject to hydrologic and institutional constraints. Results indicate that drought produces considerable impacts on both agriculture and municipal and industrial (MI) uses in the Rio Grande watershed. In-stream flow requirements to support endangered species' habitat produce the largest impacts on agricultural water users in New Mexico and Texas. Hydrologic and economic impacts are more pronounced when in-stream flow requirements dictate larger quantities of water for endangered species' habitat. Higher in-stream flow requirements for endangered species in central New Mexico cause considerable losses to New Mexico agriculture above Elephant Butte Reservoir and to MI users in Albuquerque, New Mexico. Those same in-stream flow requirements reduce drought damages to New Mexico agriculture below Elephant Butte Reservoir and reduce the severity of drought damages to MI users in El Paso, Texas. Results provide a framework for formulating federal policy responses to drought in the Rio Grande Basin.

  7. 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

  8. Intracontinental rift comparisons: Baikal and Rio Grande Rift Systems

    NASA Astrophysics Data System (ADS)

    Lipman, P. W.; Logatchev, N. A.; Zorin, Y. A.; Chapman, C. E.; Kovalenko, V.; Morgan, P.

    Both the Baikal rift in Siberia and the Rio Grande rift in New Mexico, Colorado and Texas are major intracontinental extensional structures of Cenozoic age that affect regions about 1500 km long and several hundred km wide (Figures 1, 2). In the summer of 1988 these rifts were visited by study groups of U.S. and Soviet geoscientists during cooperative field workshops sponsored by the Soviet Academy of Sciences, U.S. National Academy of Sciences, and U.S. Geological Survey.In the Rio Grande region, we spent 2 weeks examining rift features between El Paso, Tex., and Denver, Colo. Particular emphasis was on the sedimentary record of rift evolution, widespread volcanic activity from inception of rifting to the present, geophysical expression of rift features, and relations between rifting and the larger-scale evolution of the North American Cordillera. In the Baikal region, which presents formidable logistic problems for a workshop, we travelled by bus, truck, helicopter, and ship to examine young seismotectonic features, rift-related basalt, and bounding structures of the Siberian craton that influenced rift development (Figure 3).

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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…

  15. Landscape evolution in tidal embayments: modeling the interplay of erosion, sedimentation, and vegetation dynamics

    NASA Astrophysics Data System (ADS)

    D'Alpaos, A.; Lanzoni, S.; Marani, M.; Rinaldo, A.

    2006-12-01

    Modeling the long-term landscape evolution of tidal embayments requires a holistic eco-geomorphological approach to incorporate the description of the delicate balance and strong feedbacks characterizing hydrodinamic and sediment transport processes on the one hand, and ecological dynamics on the other. In order to address issues of conservation of these delicate systems and predict their future fate we have set up a process-based eco-morphodynamic model which conceptualizes the chief landforming processes operating on the intertwined, long-term evolution of marsh platforms and tidal networks cutting through them. Such a model is aimed at improving our understanding of the main processes shaping the geomorphological and biological characters of the tidal landscape. Based on observational evidence indicating the existence of different time scales governing the various landscape-forming processes, the model decouples the initial rapid network incision from its subsequent slower elaboration and from the eco-morphological evolution of intertidal areas, governed by sediment erosion and deposition and crucially affected by the presence of vegetation. This allows us to investigate the response of tidal morphologies to different scenarios of sediment supply, colonization by halophytes and changing sea level. Different morphological evolutionary regimes are shown to depend on marsh ecology. Marsh accretion rates, enhanced by vegetation growth, and the related platform elevations are found to decrease with distance from the creek, measured along suitably defined flow paths. The negative feedback between surface elevation and its inorganic accretion rate is reinforced by the relation between plant productivity and soil elevation in Spartina-dominated marshes, whereas counteracted by positive feedbacks in marshes populated by a variety of vegetation species. When evolving under constant sea level, unvegetated and Spartina-dominated marshes asymptotically tend to mean high

  16. 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

  17. 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

  18. Hydrogeologic framework of the shallow aquifers in the Ikom-Mamfe Embayment, Nigeria using an integrated approach

    NASA Astrophysics Data System (ADS)

    Edet, Aniekan; Okereke, C. S.

    2014-04-01

    A detailed hydrogeological investigation was carried out in the Ikom-Mamfe Embayment of Nigeria using lineaments, geological, geoelectrical, and hydraulic parameters. The objective was to assess aquifer framework and resource potential of the area. The study was carried out because the aquifers are of particular importance as they are more or less the only source of water supply available for the rural population. In addition, expanding communities will trigger increase in water demand that will translate to more dependence on groundwater. The study identified four major hydrostratigraphic units: Mamfe (oldest), Ezillo, Amaseri and intrusives (youngest). A comprehensive investigation of the basin revealed its lateral and vertical dimensions and hydrogeological characteristics. Moreover, study of lineaments, aquifer parameters, water level fluctuations confirmed the heterogeneity of the aquifers and their potentials to rural water supply. Water rock interactions, mainly silicate weathering, explain the groundwater compositions which are Ca-HCO3, Ca-HCO3-Cl and Ca-Na-HCO3. The water quality is good for domestic and agricultural uses. However, in terms of vulnerability of the aquifers to pollution, 80% of the Ikom-Mamfe Embayment has been classified as medium to high vulnerability.

  19. 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…

  20. 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...

  1. 77 FR 58025 - Texas Regulatory Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-19

    ... 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 of 1977 (SMCRA or the Act). Texas proposed revisions to its regulations regarding annual permit...

  2. 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…

  3. 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

  4. 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

  5. U and Sr Isotope Tracers of Agricultural Salinity Sources to the Lower Rio Grande River

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Szynkiewicz, A.; Jin, L.; McIntosh, J. C.

    2014-12-01

    Elevated salinity of the lower Rio Grande River deteriorates water quality and limits domestic and agricultural water use. Both natural and anthropogenic processes contribute salts in the Rio Grande. Previous studies have focused on natural salt contributions with less emphasis on anthropogenic sources of salinity in the Rio Grande. Using (234U/238U) activity ratios (UAR), 87Sr/86Sr isotope ratios, and major element concentrations, we aim to trace and quantify the salt loads in the Lower Rio Grande watershed which is greatly impacted by agricultural activities. Between 2009 and 2010, we sampled the Rio Grande stretch and irrigation return flows between the Elephant Butte Reservoir, New Mexico and El Paso, Texas. Furthermore, we monitored in monthly intervals the temporal changes of chemical and isotopic compositions of the Rio Grande at Canutillo, Tx. Our results show higher U and Sr fluxes in the Rio Grande during the irrigation season as compared to the non-irrigation season. The UAR (1.62 to 2.13) and 87Sr/86Sr ratios (0.7099 to 0.7138) were higher in the non-irrigation season compared to the irrigation season (UAR: 1.69 to 1.77; 87Sr/86Sr: 0.7100 to 0.7106). These variations of UAR and 87Sr/86Sr ratios imply multiple sources of U and Sr in the Rio Grande. In contrast, the agricultural return flows show a narrow range of UAR (1.31 to 1.37) and 87Sr/86Sr ratios (0.7091 to 0.7099) in the studied seasons. This is consistent with salinity contributions from agricultural sources. Rio Grande at Canutillo shows low UAR (1.62 to 1.77) and 87Sr/86Sr ratios (0.7104 to 0.7105) during the irrigation season as compared to the non-irrigation season (UAR: 2.04 to 2.24; 87Sr/86Sr: 0.7105 to 0.7109). The low U and Sr signature at Canutillo during the irrigation season is close to that of the agricultural return flows, indicative of agricultural salinity sources. These results provide useful elemental and isotopic constraints for future mass balance calculations of salinity

  6. 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.

  7. 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.

  8. 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...

  9. Radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin

    SciTech Connect

    Booher, J.L.; Fresquez, P.R.; Carter, L.F.; Gallaher, B.M.; Mullen, M.A.

    1998-02-01

    In 1992-93, Los Alamos National Laboratory collaborated with the U.S. Geological Survey in an effort to characterize radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin from Colorado to Texas. Bed sediment was sampled from 18 locations for cesium ({sup 137}Cs), tritium ({sup 3}H), strontium ({sup 90}Sr), plutonium ({sup 238}Pu and {sup 239}Pu), americium ({sup 241}Am), total uranium ({sup tot}U) and alpha, beta, and gamma activity. Fish tissue was sampled from 12 locations for {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu and {sup tot}U.

  10. 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.

  11. 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

  12. 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.

  13. Grand unification: quo vadis domine

    SciTech Connect

    Senjanovic, G.

    1985-01-01

    The present theoretical and experimental situation with grand unification is summarized. The issues of proton decay and the Weinberg angle are addressed, going through the predictions of both the standard SU(5) theory and its supersymmetric extension. The SO(10) theory, which provides a minimal one family model, is then studied. The gravitational characteristics of domain walls and strings are then discussed. It is argued that there is a need to go beyond SO(10) in order to incorporate a unified picture of families. This leads to the prediction of mirror fermions, whose physics is analyzed. 31 refs. (LEW)

  14. ""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 "colonias" in…

  15. Upper Texas Gulf Coast, USA

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The upper Texas Gulf Coast (29.0N, 95.5W), though mostly cloud covered in this view, is still readily identifiable because of the distinctive features of the Texas Gulf Coast. Galveston Island, Galveston Bay and the coastal prairie are in the clear. Most of the city of Houston is cloud covered but the Gulf Freeeway connecting Houston and Galveston can be traced for most of it's route.

  16. Upper Texas Gulf Coast, USA

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The Upper Texas Gulf Coast (29.0N, 95.5W) is clearly represented in this view from space. The area covered stretches almost 300 miles from Aransas Pass, on the Texas coast in the south to Cameron, Louisiana in the north. The sharp detail of both the natural and cultural features throughout the scene is especially evident in the Houston area where highways, major streets, airport runways and even some neighborhood lanes can be easily seen.

  17. 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.

  18. Standing stock and production rate of phytoplankton and a red tide outbreak in a heavily eutrophic embayment, Dokai Bay, Japan.

    PubMed

    Tada, K; Morishita, M; Hamada, K; Montani, S; Yamada, M

    2001-11-01

    The seasonal variation of phytoplankton biomass and primary productivity in a heavily eutrophic embayment, Dokai Bay, Japan, was determined. Dokai Bay was characterized by high phytoplankton biomass and productivity during summer and low phytoplankton biomass and productivity during other seasons. The results suggested that phytoplankton growth was limited by only irradiance and water temperature under the high nutrient concentrations available for phytoplankton growth in the entire year. Moreover, in spite of sufficient nutrient for phytoplankton growth in the entire year, a red tide occurred only in the summer period in this bay. Our results suggested that a red tide occurred by the high phytoplankton growth rate in the summer season, but in other periods surface phytoplankton was flushed out of the bay before forming the red tide, because phytoplankton growth rate was low and could not form the red tide due to low irradiance and low water temperature.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. The Texas Supernova Search

    NASA Astrophysics Data System (ADS)

    Quimby, Robert

    2006-12-01

    Supernovae (SNe) are popular tools to explore the cosmological expansion of the Universe owing to their bright peak magnitudes and reasonably high rates; however, even the relatively homogeneous Type Ia supernovae are not perfect standard candles intrinsically. Their absolute peak brightness must be established by corrections that have been largely empirical. Hundreds of SNe are now found every year, shrinking the statistical errors in the cosmological terms, but most of these distant discoveries do little to further the physical understanding of SNe, which may illuminate unknown systematics. This talk will describe recent results from the The Texas Supernova Search, a campaign designed to discover not the most SNe nor the most distant SNe, but instead to amass a small collection of well-observed nearby SNe with detailed, multi-epoch spectral observations beginning at the earliest possible phases. For the past two years, we have pointed ROTSE-IIIb's 1.85 x 1.85 degree field of view at nearby galaxy clusters and searched thousands of galaxies, covering hundreds of square degrees on the sky, for supernovae. With ToO time on the neighboring 9.2m Hobby-Eberly Telescope, we have captured SNe spectra at some of the earliest phases ever. I will discuss the implications of these data on the physics of SNe explosions, including the propagation of the burning front and the progenitors of Type Ia supernovae.

  4. 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.

  5. 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

  6. 75 FR 68398 - Texas, Oklahoma & Eastern Railroad, LLC-Acquisition and Operation Exemption-Texas, Oklahoma...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-05

    ... Surface Transportation Board Texas, Oklahoma & Eastern Railroad, LLC--Acquisition and Operation Exemption--Texas, Oklahoma & Eastern Railroad Company Texas, Oklahoma & Eastern Railroad, LLC (TOE), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to acquire from Texas,...

  7. 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

  8. Grand challenges for biological engineering

    PubMed Central

    Yoon, Jeong-Yeol; Riley, Mark R

    2009-01-01

    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. PMID:19772647

  9. 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...

  10. 27 CFR 9.156 - Diablo Grande.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Diablo Grande. 9.156... Diablo Grande. (a) Name. The name of the viticultural area described in this section is “Diablo Grande”. (b) Approved maps. The appropriate maps for determining the boundary of the Diablo...

  11. 27 CFR 9.156 - Diablo Grande.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Diablo Grande. 9.156... Diablo Grande. (a) Name. The name of the viticultural area described in this section is “Diablo Grande”. (b) Approved maps. The appropriate maps for determining the boundary of the Diablo...

  12. 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.

  13. Organic priority pollutants in nearshore fish from 14 Lake Michigan tributaries and embayments, 1983

    SciTech Connect

    Camanzo, J.; Rice, C.P.; Jude, D.J.; Rossmann, R.

    1987-01-01

    Composite, nearshore, whole fish samples of selected species, collected in fall 1983 from 13 Lake Michigan tributaries and Grand Traverse Bay, were analyzed for a wide range of pesticides and priority pollutants using gas chromatography-mass spectrometry. This study was carried out to identify existing source areas for known and previously unrecognized toxic substances. The authors strategy was to analyze those resident fish with the highest likely levels of contaminant. All fish analyzed exceeded the 2 mg/kg FDA action levels for PCBs, while 50% of the samples exceeded the DDTr IJC objective of 1 mg/kg. St. Joseph River common carp (Cyprinus carpio) carried the heaviest contaminant burden of all fish examined for PCBs (27.6 mg/kg), DDTr (10.2 kg/mg), and toxaphene (3.3 mg/kg); chlordane levels (0.85 mg/kg) were second highest to those in Kalamazoo River common carp (0.87 mg/kg). Concentrations of PCBs, toxaphene, DDT, DDE, and other pesticides were higher in bottom-feeding fish, such as common carp, than in top predators, e.g., northern pike (Esox lucius). Bottom feeders are relatively fatty fish, and live and feed near contaminated sediments, which increases their potential to bioaccumulate fat-soluble contaminants. Pesticides were also present in elevated concentrations in fish from sites with higher industrial and agricultural development. 31 references, 1 figure, 4 tables.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

    1980-12-01

    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. Relativistic astrophysics - The view from Texas in Baltimore /Review/

    NASA Technical Reports Server (NTRS)

    Trimble, V. L.; Maran, S. P.

    1981-01-01

    Recent observational and theoretical work presented at the Tenth Texas Symposium on Relativistic Astrophysics held in Baltimore, Maryland from December 15-19, 1980, is outlined. Areas covered include the theoretical foundations of relativistic astrophysics in general relativity, quantum gravitational theory and the association of grand unification with astronomical and cosmological issues, the cosmic microwave, X-ray, gamma-ray, UV, cosmic ray and gravitational wave backgrounds, the current expansion rate and average mass-energy density of the universe, and mechanisms of galaxy formation. Also discussed are the characteristics of active galaxies and clusters emitting in the gamma-ray and X-ray regions, and compact objects formed from supernova explosions, including pulsars, X-ray-emitting neutron stars, Sco X-1 and SS 433, gamma-ray sources, and X-ray and gamma-ray bursters.

  17. 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…

  18. 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…

  19. Master Plan for Texas Higher Education 1990.

    ERIC Educational Resources Information Center

    Texas Higher Education Coordinating Board, Austin.

    This 5-year plan for Texas higher education, designed to present a "road-map" for all participants in Texas higher education to use in their fulfillment of the higher education mission as established by the Texas Charter for Public Higher Education, is organized around six principles established by the charter. Following an overview on Texas…

  20. 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:…

  1. Administrative Expenditures in Texas Public Universities, 1996.

    ERIC Educational Resources Information Center

    Texas Higher Education Coordinating Board, Austin.

    This document presents text and graphs to provide an overview of administrative expenditures in institutions of higher education in Texas. Administrative expenditure indicators at Texas public senior universities are compared with each other, with national averages, and with averages of the 10 states nearest Texas in population. In constant…

  2. 21 CFR 808.93 - Texas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Texas. 808.93 Section 808.93 Food and Drugs FOOD... 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...

  3. 21 CFR 808.93 - Texas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Texas. 808.93 Section 808.93 Food and Drugs FOOD... 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...

  4. 21 CFR 808.93 - Texas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Texas. 808.93 Section 808.93 Food and Drugs FOOD... 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...

  5. 21 CFR 808.93 - Texas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Texas. 808.93 Section 808.93 Food and Drugs FOOD... 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, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Texas. 808.93 Section 808.93 Food and Drugs FOOD... 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. 76 FR 15358 - Texas Disaster #TX-00371

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ... ADMINISTRATION Texas Disaster TX-00371 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 03/14/2011. Incident: Texas Panhandle Wildfires. Incident Period: 02/27/2011 through 02/28/2011. Effective Date:...

  8. 75 FR 48384 - Texas Disaster #TX-00361

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-10

    ... ADMINISTRATION Texas Disaster TX-00361 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Texas (FEMA-1931-DR... Counties (Economic Injury Loans Only): Texas: Brooks, Crockett, Dimmit Duval, Edwards, Kenedy, Kinney...

  9. 77 FR 6620 - Texas Disaster #TX-00385

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... ADMINISTRATION Texas Disaster TX-00385 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 01/30/2012... adversely affected by the disaster: Primary Counties: Harris. Contiguous Counties: Texas: Brazoria,...

  10. 76 FR 28841 - Texas Disaster # TX-00376

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... ADMINISTRATION Disaster Declaration 12564 and 12565 Texas Disaster TX-00376 AGENCY: U.S. Small Business... State of Texas dated 05/09/2011. Incident: Wichita County Complex Wildfires. Incident Period: 04/15/2011.... Contiguous Counties: Texas: Archer, Baylor, Clay, Wilbarger, Oklahoma: Cotton, Tillman. The Interest...

  11. 75 FR 1421 - Texas Disaster # TX-00354

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

    ... ADMINISTRATION Texas Disaster TX-00354 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 01/04/2010... the disaster: Primary Counties: Angelina. Contiguous Counties: Texas: Cherokee, Houston,...

  12. 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... adversely affected by the disaster: Primary Counties: Grimes. Contiguous Counties: Texas: Brazos,...

  13. 76 FR 58329 - Texas Disaster #TX-00381

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... ADMINISTRATION [Disaster Declaration 12815 and 12816 Texas Disaster TX-00381 AGENCY: U.S. Small Business... the State of Texas (FEMA-4029-DR), dated 09/09/2011. Incident: Wildfires. Incident Period: 08/30/2011... Loans Only): Texas: Caldwell, Fayette, Lee, Travis, Williamson. The Interest Rates are: ] Percent...

  14. 76 FR 24555 - Texas Disaster #TX-00375

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... ADMINISTRATION Texas Disaster TX-00375 AGENCY: Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Texas. Dated 04/26/2011. Incident... adversely affected by the disaster: Primary Counties: Jeff Davis. Contiguous Counties: Texas,...

  15. 78 FR 27468 - Texas Disaster # TX-00401

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... ADMINISTRATION Texas Disaster TX-00401 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 May 2, 2013... adversely affected by the disaster: Primary Counties: Mclennan. Contiguous Counties: Texas: Bell;...

  16. 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 resources…

  17. 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…

  18. 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…

  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. 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

  1. Grand Junction Resource Area, Resource Management Plan, Grand Junction, Colorado

    SciTech Connect

    Not Available

    1985-03-01

    Implementation of a resource management plan is proposed for the 2.0-million-acre Grand Junction Planning Area, located in west-central Colorado. Under the preferred alternative, existing withdrawals from mineral location on 124,442 acres would continue and an additional 154,067 acres would be withdrawn. Approximately 14,100 acres would be identified as unsuitable for further coal leasing. Approximately 624,701 acres would be open to oil and gas leasing without stipulations; 685,603 acres would be open to oil and gas leasing with stipulations; and 149,087 acres would be closed to oil and gas leasing. Air quality enhancement, soil stabilization, and watershed protection would be emphasized. Habitats of major wildlife species and of threatened and endangered plants and animals would be actively managed, but no new livestock management actions would be implemented. The wild horse herd would be allowed to expand from 65 to 120 animals. Paleontological sites and 11,685 archaeological sites would be protected. Approximately 1319 acres of commercial forest land would be identified as suitable for management, and 2800 cords of fuel wood would be offered for sale annually. The three existing developed recreation sites would be maintained, and the Mud Springs site would be expanded to accommodate more group use.

  2. 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)…

  3. 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.

  4. Quantifying Saline Groundwater Discharge to the Rio Grande using 87Sr/86Sr and [Ca]/[Sr] Ratios

    NASA Astrophysics Data System (ADS)

    Hogan, J. F.; Phillips, F. M.; Mills, S. K.; Ruiz, J.; Chesley, J. T.

    2002-12-01

    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. We have conducted winter and summer synoptic sampling of the Rio Grande from the headwaters in Colorado to south of El Paso, Texas. The total dissolved solids content (TDS) of the Rio Grande increases from less than 50 mg/L in headwater regions of Colorado to greater than 2000 mg/L south of El Paso, Texas. Increases in salinity are not a simple function of distance downriver, but rather occur in a series of steps. Many of these increases are located at the lower end of sedimentary basins leading to the hypothesis that they are the result of discharge of deep, saline, groundwaters. Of particular interest is the Albuquerque and Socorro basins where, in three distinct steps, the TDS of the river doubles from ~ 150 mg/L to ~ 300 mg/L. With little change in river discharge for this reach, this represents a significant increase in the solute burden of the river. We have used 87Sr/86Sr and [Ca]/[Sr] ratios to "fingerprint" and quantify saline groundwater discharge. The Rio Grande entering the Albuquerque basin has an 87Sr/86Sr ratio of 0.7096and a [Ca]/[Sr] ratio of 80. These values are consistent with a mixture of atmospheric deposition and weathering of basalt rock found upstream. Traveling through the Albuquerque and Socorro basin the Rio Grande shifts to a 87Sr/86Sr ratio of 0.7102 and a [Ca]/[Sr] ratio of 30, values which are consistent with saline groundwater discharge. Mixing relationships indicate only two solute sources are required, and that a total saline groundwater discharge rate of ~ 50 cfs is sufficient to explain the observed salinity increases.

  5. Assessment of physicians' information needs in five Texas counties.

    PubMed Central

    Bowden, V M; Kromer, M E; Tobia, R C

    1994-01-01

    In 1990, a questionnaire was mailed to all physicians in four counties in the lower Rio Grande Valley of Texas and to a random sample of physicians in Bexar County, Texas (San Antonio). Two hundred and eighty of 573 Valley physicians (48.9%) and 162 of 273 Bexar County physicians (59.3%) responded to the survey, for an overall response rate of 52.2%. The two groups were compared primarily to determine differences between physicians who have access to established medical libraries and physicians who practice in remote areas without local access to medical information. Demographic variables, professional practice characteristics, and patient characteristics were compared. Information resource use, particularly reasons for use and non-use of MEDLINE, was explored. Questions also were asked about the availability of various types of information technology. The results indicated that differences in the health care profile did not affect the information usage of the physicians but that differences did exist between the two groups in the use of MEDLINE and libraries. There was no statistically significant difference in either group's rating of experience with using databases, with more than 40% in each group rating themselves as not at all experienced. PMID:8004024

  6. Fracture enhancement based on artificial ants and fuzzy c-means clustering (FCMC) in Dezful Embayment of Iran

    NASA Astrophysics Data System (ADS)

    Nasseri, Aynur; Jafar Mohammadzadeh, Mohammad; Hashem Tabatabaei Raeisi, S.

    2015-04-01

    This paper deals with the application of the ant colony algorithm (AC) to a seismic dataset from Dezful Embayment in the southwest region of Iran. The objective of the approach is to generate an accurate representation of faults and discontinuities to assist in pertinent matters such as well planning and field optimization. The AC analyzed all spatial discontinuities in the seismic attributes from which features were extracted. True fault information from the attributes was detected by many artificial ants, whereas noise and the remains of the reflectors were eliminated. Furthermore, the fracture enhancement procedure was conducted by three steps on seismic data of the area. In the first step several attributes such as chaos, variance/coherence and dip deviation were taken into account; the resulting maps indicate high-resolution contrast for the variance attribute. Subsequently, the enhancement of spatial discontinuities was performed and finally elimination of the noise and remains of non-faulting events was carried out by simulating the behavior of ant colonies. After considering stepwise attribute optimization, focusing on chaos and variance in particular, an attribute fusion was generated and used in the ant colony algorithm. The resulting map displayed the highest performance in feature detection along the main structural feature trend, confined to a NW-SE direction. Thus, the optimized attribute fusion might be used with greater confidence to map the structural feature network with more accuracy and resolution. In order to assess the performance of the AC in feature detection, and cross validate the reliability of the method used, fuzzy c-means clustering (FCMC) was employed for the same dataset. Comparing the maps illustrates the effectiveness and preference of the AC approach due to its high resolution contrast for structural feature detection compared to the FCMC method. Accordingly, 3D planes of discontinuity determined spatial distribution of fractures

  7. 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

  8. Aeromagnetic and gravity imaging of subglacial geology beneath major ice streams flowing in the Weddell Sea Embayment

    NASA Astrophysics Data System (ADS)

    Ferraccioli, Fausto; King, Owen; Jordan, Tom; Ross, Neil; Bingham, Rob; Rippin, David; LeBrocq, Anne; Siegert, Martin; Smith, Andy; Hindmarsh, Richard

    2014-05-01

    Extensive airborne geophysical research has helped unveil subglacial geology beneath the West Antarctic Ice Sheet (WAIS) in particular over the Ross Sea Embayment. Three key geological controls on the onset and maintenance of fast glacial flow for the WAIS have emerged including the presence of widespread subglacial sediments deposited within deep rift basins, thinner drapes of marine sediments within the low lying topography of the West Antarctic Rift System (WARS) and high geothermal heat flux associated with Cenozoic rift-related magmatism. Here, we compile a suite of new and vintage aerogeophysical observations over the catchments of several major ice streams flowing into the Weddell Sea Embayment to examine their large-scale geological setting and assess the role of regional geological controls on subglacial topography and WAIS flow regimes. Specifically, we examine the subglacial geology beneath the catchments of the Institute and Moeller ice streams, the Rutford ice stream and the Evans ice stream using a combination of airborne radar, aeromagnetic and airborne gravity imaging. We show that the Moeller ice stream is underlain by the largest strike-slip fault system recognised so far along the tectonic boundary between East and West Antarctica. This fault system controls the location of a set of en-echelon subglacial basins that steer enhanced flow inland. We find no evidence, however, for deep sedimentary basins along this fault system, suggesting that subglacial sediments are not necessarily a geological template for the onset of fast flow. However, the newly identified Robin Subglacial Basin that underlies the fast flowing coastal region of the Institute ice stream contains 1-3 km of sedimentary infill and remarkably smooth bedrock topography. Enhanced flow in the tributaries of the Institute ice stream that cut through the Ellsworth Mountains are controlled by major basement faults likely active in Cambrian and Permian times and perhaps reactivated during

  9. 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

  10. 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.

  11. A new imminent grand minimum?

    NASA Astrophysics Data System (ADS)

    Cionco, Rodolfo G.; Compagnucci, Rosa H.

    2012-07-01

    The planetary hypothesis of solar cycle is an old idea by which the planetary gravity acting on the Sun might have a non-negligible effect on the solar magnetic cycle. The advance of this hypothesis is based on phenomenological correlations between dynamical parameters of the Sun's movement around the barycenter of the Solar System and sunspots time series. In addition, several authors have proposed, using different methodologies that the first Grand Minima (GM) event of the new millennium is coming or has already begun. We present new fully three dimensional N-body simulations of the solar inertial motion (SIM) around the barycentre of the solar system in order to perform a phenomenological comparison between relevant SIM dynamical parameters and the occurrences of the last GM events (i.e., Maunder and Dalton). Our fundamental result is that the Sun acceleration decomposed in a co-orbital reference system shows a very particular behaviour that is common to Maunder minimum, Dalton minimum and the maximum of cycle 22 (around 1990), before the present prolonged minimum. We discuss our results in terms of a dynamical characterization of GM with relation to Sun dynamics and possible implications for a new GM event.

  12. 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.

  13. 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…

  14. 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)

  15. 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.…

  16. Texas Adult Education Curriculum Guide.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Extension Instruction and Materials Center.

    This guide was created to provide Texas adult educators with a state-of-the-art resource for practical information about adult education materials and methods for their own growth and that of their students. The guide is organized in four parts. Part I provides preparatory information on the following topics: related resources; characteristics of…

  17. Don't NOx Texas

    SciTech Connect

    Mathis, J.D.; Lachowicz, Y.

    2005-07-01

    Modifications to boiler combustion systems allow Fayette Power Projects units 1 and 2 to meet new NOx emissions limits east of La Grange in Eastern Texas. The article describes modifications executed by Alstom in 2004 which attained an overall reduction in NOx emissions of almost 69%. 4 figs., 1 tab., 1 photo.

  18. "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…

  19. Texas Higher Education in Transition.

    ERIC Educational Resources Information Center

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

    The status of higher education in Texas is examined in this major report of changes in higher education over the past decade. Information on enrollment, cost, financial aid, job opportunities, and facilities in higher education institutions is given for private higher education, professional higher education, community colleges, and state colleges…

  20. 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 of…

  1. 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.

  2. 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

  3. Wil Wheaton and the Grand Entrance

    NASA Video Gallery

    As NASA prepares for Curiosity rover landing on Mars, Wil Wheaton shares this thrilling story of NASA's hardest planetary science mission to date. The video titled, "Grand Entrance," guides viewers...

  4. William Shatner and the Grand Entrance

    NASA Video Gallery

    As NASA prepares for Curiosity rover landing on Mars, William Shatner shares this thrilling story of NASA's hardest planetary science mission to date. The video titled, "Grand Entrance," guides vie...

  5. Wintertime meteorology of the Grand Canyon region

    SciTech Connect

    Whiteman, C.D.

    1992-09-01

    The Grand Canyon region of the American Southwest is an interesting region meteorologically, but because of its isolated location, the lack of major population centers in the region, and the high cost of meteorological field experiments, it has historically received little observational attention. In recent years, however, attention has been directed to episodes of visibility degradation in many of the US National parks, and two recent field studies focused on this visibility problem have greatly increased the meteorological data available for the Grand Canyon region. The most recent and comprehensive of these studies is the Navajo Generating Station Winter Visibility Study of 1989--90. This study investigated the sources of visibility degradation in Grand Canyon National Park and the meteorological mechanisms leading to low visibility episodes. In this paper we present analyses of this rich data set to gain a better understanding of the key wintertime meteorological features of the Grand Canyon region.

  6. Grand rounds: what is the point?

    PubMed

    Martin, Markus

    2005-05-01

    INTRODUCTION The chalkboards are no longer only chalkboards but are PowerPoint presentations. Textbooks are rarely texts but rather CDs to be downloaded at a reader's discretion; and classrooms are almost optional. Still the university hospital environment reflects a belief in the pedagogic effectiveness of the 19th century medical wisdom by encouraging and maintaining grand rounds. What makes the grand rounds is debatable. The large crowds, which historically attended to hear and to feast on a specialist's pearls of wisdom, have been replaced by sparse crowds often inattentive and in a rush to be elsewhere. This survey was designed to assess the status of the grand round in Canada. We contacted the 16 medical schools via e-mail and asked either the chairperson or the obs-gyn grand round coordinator to respond to a 2-page questionnaire. The Association of professors of Obstetrics and Gynecology (APOG) assisted in diffusing and collecting the data. PMID:16100647

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Low-frequency Acoustic/Seismic Coupling in Deep Sediments: Skyquakes Look Like Earthquakes in the Mississippi Embayment (Invited)

    NASA Astrophysics Data System (ADS)

    Langston, C. A.

    2010-12-01

    Space Shuttle Discovery passed over the southern Mississippi River valley on November 7, 2007, and again on April 20, 2010, creating audible sonic booms that were recorded by seismic stations and infrasound sensors in the area. The seismoacoustic interaction of the infrasound N-wave with the deep, unconsolidated sediments of the Mississippi embayment created large 1-3 sec period fundamental and higher mode surface waves that were precursory to the atmospheric acoustic wave arrival at many stations. Seismoacoustic coupling was facilitated by the very low S and P wave velocity structure of the sediments, the relatively uniform regional extent of sedimentary strata, and the relatively high horizontal phase velocity of the N-wave as it interacted with the Earth's surface within 20 km of the trajectory ground track. These unusual data are used to infer the physical properties of the sediments to depths of approximately a kilometer. Analysis of the particle motion of the acoustic wave arrival gives additional information on the near-surface site response of individual stations for the upper 10's of meters. The complexity and duration of seismic signals from these large sonic boom sources are similar in character to shallow earthquakes and explosions within nearby seismic zones and provide useful information that can be used in wave propagation and site response studies for evaluating local earthquake shaking hazards.

  16. Cambrian palaeomagnetic data confirm a Natal Embayment location for the Ellsworth-Whitmore Mountains, Antarctica, in Gondwana reconstructions

    NASA Astrophysics Data System (ADS)

    Randall, Darren E.; Mac Niocaill, Conall

    2004-04-01

    The Ellsworth-Whitmore Mountains (EWM) are one of five terranes that form West Antarctica. Constraining the positions of these terranes in pre-break up Gondwana is crucial to understanding the history of the palaeo-Pacific Gondwana margin. We report the results of a detailed palaeomagnetic investigation of the EWM, which comprises some 150 sites in six formations, ranging in age from Cambrian to Permian. Five of the studied units yield only viscous remnant magnetizations of recent age, or unstable natural remanent magnetizations. The remaining unit, the mid-late Cambrian Frazier Ridge Formation, yielded stable magnetizations at 16 of 35 sites. This component passes a fold test at the 95 per cent confidence level, indicating that it pre-dates Permian deformation, and we argue that it is of primary origin. The resulting palaeopole (9°N 293°E A95= 5.1°) is in good agreement with two previously published palaeopoles from similarly aged rocks in the EWM. Collectively these data indicate that the EWM were located in the Natal Embayment prior to Gondwana break-up, and underwent 90° of anticlockwise rotation during break-up. All three studies, however, yield inclinations that are slightly too shallow when compared with coeval Gondwana reference poles.

  17. New Cambrian paleomagnetic data reaffirm a Natal Embayment position for the Ellsworth-Whitmore Mountains in Gondwana reconstructions.

    NASA Astrophysics Data System (ADS)

    Mac Niocaill, C.; Randall, D.; Curtis, M.

    2003-04-01

    The Ellsworth-Whitmore Mountains (EWM) are one of five allochtonous terranes that form West Antarctica. Constraining the positions of these terranes in pre-break up Gondwana is crucial to understanding the history of the Paleo-Pacific Gonwana margin. We report the results of a detailed paleomagnetic investigation of the EWM, which comprises some 150 sites in six Formations, ranging in age from Cambrian to Permian. Five of the studied units yield only viscous remnant magnetisations of recent age, or unstable NRMs. The remaining unit, the mid-late Cambrian Frazier Ridge Formation, yielded stable magnetisations at 16 of 35 sites. This component passes a fold test at 95% confidence, indicating that it pre-dates Permian deformation, and we argue that it is of primary origin. The resulting paleople (9°N 293°E A95=5.1°) is in good agreement with two previously published paleopoles from similarly aged rocks in the EWM, and collectively they indicate that the EWM were located in the Natal Embayment rpior to Gondwana break up, and underwent 90° of anticlockwise rotation during break-up. All three studies, however, yield inclinations that are slightly too shallow when compared with coeval Gondwana reference poles.

  18. 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... Uniontown Compressor Station located in Fayette County, Pennsylvania. Texas Eastern states that there...

  19. 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... enable Texas Eastern to provide up to 112,000 dekatherms per day (Dth/d) of firm lateral...

  20. 76 FR 7833 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on January 25, 2011, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas... Gas Act (NGA) for its proposed TEAM 2012 Project. Specifically, Texas Eastern requests:...

  1. 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... proposed TEAM 2012 Project. Specifically, Texas Eastern's original application is amended to reduce...

  2. 76 FR 18210 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application On March 15, 2011, Texas Eastern Transmission Corporation (Texas Eastern), 5400 Westheimer Court, Houston, Texas 77056-5310... & Certificates, Texas Eastern Transmission, LP, P.O. Box 1642, Houston, TX 77251-1642, at (713) 627-4488...

  3. Prevalence of certain antibodies to selected disease-causing agents in wild turkeys in Texas.

    PubMed

    Hensley, T S; Cain, J R

    1979-01-01

    In Texas in 1976 and 1977, Rio Grande turkeys (Meleagris gallopavo intermedia) from seven counties and Eastern turkeys (M. g. silvestris) from one county were tested for antibodies to selected poultry pathogens. Standardized serological tests disclosed reactors to Salmonella pullorum (2.4%), S. typhimurium (2.3%), and Mycoplasma gallisepticum (4.8%). There were no reactors to Newcastle disease virus or Chlamydia psittaci. Prevalence of M. gallisepticum antibody in wild turkeys was significantly higher for counties with commercial turkey operations than for counties lacking domestic turkeys, whereas the incidence of S. pullorum and S. typhimurium did not differ significantly.

  4. 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 partially cloudy 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

  5. 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 southwest. Note the trash racks at the entrance to the penstocks. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  6. 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

    ... 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 zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  7. 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

    ... 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 zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  8. 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

    ... 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 zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  9. 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

    ... 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 zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  10. Depositional systems distribution of the lower Oligocene Vicksburg Formation, TX

    SciTech Connect

    Coleman, J.; Galloway, W.E. )

    1990-05-01

    The lower Oligocene Vicksburg Formation of Texas is situated between the upper Eocene Jackson Group and the upper Oligocene Frio Formation. The paleogeography of the Texas Gulf coastal plain during the early Oligocene is typical of a progradational passive continental margin. However, a detailed regional depositional systems analysis of stratigraphic units, such as the Vicksburg, within a mature petroleum basin can yield results beneficial in both exploration and development. Stratigraphic plays are determined from the distribution of depositional systems, and reservoir characteristics are heavily influenced by conditions of sedimentation. Two primary depocenters (and exploration fairways) of the Texas Vicksburg were the Houston Embayment and the Rio Grande Embayment; they were separated by a deep-rooted structural nose in central Texas: the San Marcos arch. Within the embayments, deltaic depositional systems merged along strike with barrier/strand plain systems. Updip, fluvial systems traversed coastal plain units. On the seaward edge of the paralic systems, sand and mud deposits prograded across, and built up over, the relict Jackson shelf and shelf margin. Contemporaneous growth faulting controlled deltaic depositional patterns in the Rio Grande Embayment and, to a lesser degree, in the Houston Embayment. A barrier/strand plain system within an interdeltaic coastal bight extended across the northern flank of the San Marcos arch. Several minor wave-dominated delta complexes were interspersed within this regional setting. The southern flank of the arch was influenced by the fluvial systems of the Rio Grande Embayment that established another wave-dominated delta. Deposition of the Vicksburg progradational paralic sediments was initiated seaward of the Jackson coastal position. A brief, minor transgression interrupted the progradational pattern during middle Vicksburg deposition.

  11. Different Views of the Grand Canyon

    NASA Astrophysics Data System (ADS)

    Elders, Wilfred A.

    Each year the spectacular scenery of the Grand Canyon of Arizona awes its more than 4,000,000 visitors. Just as its enormous scale dwarfs our human sense of space, its geology also dwarfs our human sense of time. Perhaps here, more than anywhere else on the planet, we can experience a sense of ``Deep Time.'' The colorful rocks exposed in the vertical walls of the canyon display a span of 1.8 billion years of Earth's history [Beus and Morales, 2003]. But wait! There is a different view! According to Vail [2003], this time span is only 6,000 years and the Grand Canyon and its rocks are a record of the Biblical 6 days of creation and Noah's flood. During a visit to Grand Canyon, in August 2003, I learned that Vail's book, Grand Canyon: A Different View, is being sold within the National Park. The author and compiler of Grand Canyon: A Different View is a Colorado River guide who is well acquainted with the Grand Canyon at river level. He has produced a book with an attractive layout and beautiful photographs. The book is remarkable because it has 23 co-authors, all male, who comprise a veritable ``Who's Who'' in creationism. For example, Henry Morris and John Whitcomb, the authors of the seminal young Earth creationist text, The Genesis Flood [Whitcomb and Morris, 1961], each contribute a brief introduction. Each chapter of Grand Canyon: A Different View begins with an overview by Vail, followed by brief comments by several contributors that ``have been peer reviewed to ensure a consistent and Biblical perspective.'' This perspective is strict Biblical literalism.

  12. Texas innovates production data retrieval

    SciTech Connect

    Schieck, D.E.; Cisco, S.L.

    1998-10-26

    The Railroad Commission of Texas now offers an Internet web-based system that provides access to Texas oil and gas production data in an interactive query format. With this system, both the public and state agency personnel can access and customize the available information. The ACTI (Advanced Computational Technology Initiative) data base contains well production information that is a crucial component for evaluating the feasibility of many exploration, acquisition, and operation decisions. The RRC has always provided public access to oil and gas production data and related well information, but access mechanisms were limited because the data resided in multiple storage formats, including paper, microforms, and mainframe data bases. For both internal and external users, the ACTI production query system eliminates time-consuming research with paper and film-based records and costly special programming requests. Internet-based access to RRC production data is increasing daily, and ACTI is the most popular information available on RRC`s web site.

  13. 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.

  14. Houston/Galveston, Texas, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In this view of Houston/Galveston, Texas, USA (29.5N, 95.5W), heavy spring rains emphasize the several bodies of water in the area. Even though partially cloud covered, the progressive nature of the Houston highway and freeway system can easily be observed in this highly detailed view. To the south, the NASA, Clear Lake area just off of Galveston Bay can easily be seen. In the center, is the downtown business district.

  15. Houston/Galveston, Texas, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In this view of Houston/Galveston, Texas, USA (29.5N, 95.5W), heavy spring rains emphasize the several bodies of water in the area. The progressive nature of the Houston highway and freeway system can easily be observed in this highly detailed view. Houston Intercontiental Airport can be seen to the north and to the south, the NASA, Clear Lake area just off of Galveston Bay can easily be seen. In the center, is the downtown business district.

  16. 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.

  17. 76 FR 7187 - East Texas Electric Cooperative, Inc., Texas; Notice of Availability of Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ... Energy Regulatory Commission East Texas Electric Cooperative, Inc., Texas; Notice of Availability of... reviewed East Texas Electric Cooperative, Inc.'s (the Cooperative's) application for license for the Lake...'' link. Enter the docket number excluding the last three digits in the docket number field to access...

  18. 2000 Comprehensive Biennial Report on Texas Public Schools. A Report to the 77th Texas Legislature.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This comprehensive report on Texas schools indicates that more than 80 percent of students pass the Texas Assessment of Academic Skills (TASS) test, and students continue to show impressive gains on math and reading tests. Chapter 1, "Student Performance," provides data on student performance on the Spring 2000 Texas Assessment of Academic Skills…

  19. Lifeomics leads the age of grand discoveries.

    PubMed

    He, Fuchu

    2013-03-01

    When our knowledge of a field accumulates to a certain level, we are bound to see the rise of one or more great scientists. They will make a series of grand discoveries/breakthroughs and push the discipline into an 'age of grand discoveries'. Mathematics, geography, physics and chemistry have all experienced their ages of grand discoveries; and in life sciences, the age of grand discoveries has appeared countless times since the 16th century. Thanks to the ever-changing development of molecular biology over the past 50 years, contemporary life science is once again approaching its breaking point and the trigger for this is most likely to be 'lifeomics'. At the end of the 20th century, genomics wrote out the 'script of life'; proteomics decoded the script; and RNAomics, glycomics and metabolomics came into bloom. These 'omics', with their unique epistemology and methodology, quickly became the thrust of life sciences, pushing the discipline to new high. Lifeomics, which encompasses all omics, has taken shape and is now signalling the dawn of a new era, the age of grand discoveries.

  20. External view of the DARPA Grand Challenge

    NASA Astrophysics Data System (ADS)

    Frederick, Philip A.; Kania, Robert; Teems, Justin; Del Rose, Mike

    2006-05-01

    The 2005 DARPA Grand Challenge (DCG) was a 'Huge Leap Forward for Robotics R&D' according to the DARPA Grand Challenge tracking website. Similar to the transatlantic flight competition that spurred commercial flights all over the world, the Grand Challenge was a step forward in the area of navigation for unmanned ground vehicles. However, questions like 'What are the important technologies brought forth by the Grand Challenge?' and 'How can these technologies assist our soldiers in the field?' need to be addressed. This paper will look at the 2005 DARPA Grand Challenge from the perspective of individuals involved in some of the Army's unmanned ground vehicle programs. Information will be presented contrasting this year's competition to the one held in 2004. Details of the enabling technologies from many of the competitors will be discussed along with problems they encountered at the National Qualification Event (NQE) and on Race Day. Finally, thoughts will be presented on how these technologies may be harvested in commercial and DOD research and development for current and future systems.

  1. Grand challenges in modeling and simulation

    NASA Astrophysics Data System (ADS)

    Gordon, Steven C.

    2002-07-01

    Few argue with the need for modeling and simulation (M&S) to better or more completely represent current and expected military operations. The challenge is to decide where to make specific improvements in M&S representation and functionality within time, funding, technology, and research limitations. So, it is natural to select key areas - Grand Challenges - for a significant evolution in M&S where a major effort of many at considerable cost is needed to deal with the critical issues ahead. This paper selects three proposed and related Grand Challenges. First, M&S Depiction of Information and Effects-Based Operations, as a Grand Challenge, will assist in creating sufficiently realistic battlespaces for M&S users. Second, M&S Support to Crisis Response and Military Operations, as a Grand Challenge, is a key area that will help the Department of Defense meet transformation goals. Third, Effective Development of Future Simulations, as a Grand Challenge, will set the standards by which future M&S improvements and new M&S programs will be acquired to ensure needed simulations are delivered on time and at desired cost.

  2. Origin of grand minima in sunspot cycles.

    PubMed

    Choudhuri, Arnab Rai; Karak, Bidya Binay

    2012-10-26

    One of the most striking aspects of the 11-year sunspot cycle is that there have been times in the past when some cycles went missing, a most well-known example of this being the Maunder minimum during 1645-1715. Analyses of cosmogenic isotopes ((14)C and (10)Be) indicated that there were about 27 grand minima in the last 11,000 yrs, implying that about 2.7% of the solar cycles had conditions appropriate for forcing the Sun into grand minima. We address the question of how grand minima are produced and specifically calculate the frequency of occurrence of grand minima from a theoretical dynamo model. We assume that fluctuations in the poloidal field generation mechanism and in the meridional circulation produce irregularities of sunspot cycles. Taking these fluctuations to be Gaussian and estimating the values of important parameters from the data of the last 28 solar cycles, we show from our flux transport dynamo model that about 1-4% of the sunspot cycles may have conditions suitable for inducing grand minima. PMID:23215173

  3. Quantifying Salinization of the Upper-Middle Rio Grande Using a Basin-Scale Water and Chloride Mass Balance Model

    NASA Astrophysics Data System (ADS)

    Mills, S. K.; Phillips, F. M.; Hogan, J. F.; Hendrickx, J. M.

    2002-12-01

    The Rio Grande is clearly undergoing salinization, manifested by a 50-fold increase in total dissolved solids content between its headwaters in Colorado and the U.S.-Mexico border. To elucidate the causes of this salinization, we conducted an eight-day synoptic sampling campaign in August 2001. This sampling included the river, its major tributaries, and major irrigation drain inflows. Along 1200 km between the river headwaters in Colorado and Fort Quitman, Texas, we collected 110 water samples with an average interval of ~10 km between sampling locales. In the laboratory, samples were analyzed for major constituents including chloride, as well as for bromide and the 36Cl/Cl ratio. Isotopic fingerprinting using the 36Cl/Cl ratio indicates that meteoric waters and deep sedimentary brines respectively account for most of the water and most of the salt inflow to the Rio Grande. The meteoric end member has a 36Cl/Cl ratio of 1100 and a Cl/Br ratio of 30; the brine end member has a 36Cl/Cl ratio of 35 and a Cl/Br ratio of 1150. Using these end member chemistries with USGS stream flow gauging data, we constructed a water- and salt- instantaneous mass balance model of the Rio Grande for the eight-day sampling interval. This model indicates that most water losses from the Rio Grande are due to evaporation from Elephant Butte reservoir, open water evaporation from irrigation ditches, and evapotranspiration of riparian and ditch-bank vegetation. The model also emphasizes the significance of salt input due to deep brine discharge to the river, particularly at the downstream ends of local sedimentary basins of the Rio Grande rift. The Rio Grande receives a smaller amount of salt from saline drains near El Paso, which may be acquiring salt from deep brine discharge as they cross over faults or other structural fluid conduits.

  4. Dissolved noble gases and stable isotopes as tracers of preferential fluid flow along faults in the Lower Rhine Embayment, Germany

    NASA Astrophysics Data System (ADS)

    Gumm, L. P.; Bense, V. F.; Dennis, P. F.; Hiscock, K. M.; Cremer, N.; Simon, S.

    2016-02-01

    Groundwater in shallow unconsolidated sedimentary aquifers close to the Bornheim fault in the Lower Rhine Embayment (LRE), Germany, has relatively low δ2H and δ18O values in comparison to regional modern groundwater recharge, and 4He concentrations up to 1.7 × 10-4 cm3 (STP) g-1 ± 2.2 % which is approximately four orders of magnitude higher than expected due to solubility equilibrium with the atmosphere. Groundwater age dating based on estimated in situ production and terrigenic flux of helium provides a groundwater residence time of ˜107 years. Although fluid exchange between the deep basal aquifer system and the upper aquifer layers is generally impeded by confining clay layers and lignite, this study's geochemical data suggest, for the first time, that deep circulating fluids penetrate shallow aquifers in the locality of fault zones, implying that sub-vertical fluid flow occurs along faults in the LRE. However, large hydraulic-head gradients observed across many faults suggest that they act as barriers to lateral groundwater flow. Therefore, the geochemical data reported here also substantiate a conduit-barrier model of fault-zone hydrogeology in unconsolidated sedimentary deposits, as well as corroborating the concept that faults in unconsolidated aquifer systems can act as loci for hydraulic connectivity between deep and shallow aquifers. The implications of fluid flow along faults in sedimentary basins worldwide are far reaching and of particular concern for carbon capture and storage (CCS) programmes, impacts of deep shale gas recovery for shallow groundwater aquifers, and nuclear waste storage sites where fault zones could act as potential leakage pathways for hazardous fluids.

  5. Fish abundances in shoreline habitats and submerged aquatic vegetation in a tidal freshwater embayment of the Potomac River.

    PubMed

    Kraus, Richard T; Jones, R Christian

    2012-05-01

    Submerged aquatic vegetation (SAV) is considered an important habitat for juvenile and small forage fish species, but many long-term recruitment surveys do not effectively monitor fish communities in SAV. To better understand the impact of recent large increases of SAV on the fish community in tidal freshwater reaches of the Potomac River, we compared traditional seine sampling from shore with drop ring sampling of SAV beds (primarily Hydrilla) in a shallow water (depths, <1.5 m) embayment, Gunston Cove. To accomplish this, we developed species-specific catch efficiency values for the seine gear and calculated area-based density in both shoreline and SAV habitats in late summer of three different years (2007, 2008, and 2009). For the dominant species (Fundulus diaphanus, Lepomis macrochirus, Etheostoma olmstedi, Morone americana, Lepomis gibbosus, and Fundulus heteroclitus), density was nearly always higher in SAV, but overall, species richness was highest in shoreline habitats sampled with seines. Although historical monitoring of fish in Gunston Cove (and throughout Chesapeake Bay) is based upon seine sampling (and trawl sampling in deeper areas), the high densities of fish and larger areal extent of SAV indicated that complementary sampling of SAV habitats would produce more accurate trends in abundances of common species. Because drop ring samples cover much less area than seines and may miss rare species, a combination of methods that includes seine sampling is needed for biodiversity assessment. The resurgence of SAV in tidal freshwater signifies improving water quality, and methods we evaluated here support improved inferences about population trends and fish community structure as indicators of ecosystem condition. PMID:21713468

  6. Holocene landscape and land-use change under human impact. Examples from Central Europe (Lower Rhine Embayment)

    NASA Astrophysics Data System (ADS)

    Lehmkuhl, Frank; Protze, Jens; Gerlach, Renate

    2015-04-01

    In the Lower Rhine Embayment (LRE), as in other parts of Central Europe, several main periods of colluvial deposition (mainly Metal Ages, Roman time, Medieval time) and four main periods of alluvial and overbank deposition in the floodplains (Early Holocene, Metal Ages, partially Roman time, Medieval, Early Modern time) can be divided. The summary of colluvial sedimentation can be shown by using interdisciplinary methods, consisting of sedimentological, geochemical and archaeological methods. This allowed reconstructing a detailed land-use history. To clarify the origin of the colluvial deposits loess-sequences also have been studied geochemically and were compared to loess- and loess-like deposits from adjacent areas, such as the Northern Eifel Mountains or the Middle Rhine. The results clearly show that only the combination of methods of natural sciences and the humanities allow optimal processing of these complex findings. To sum up these results the following cycles cause by human activities can be found in the LRE: 8 periods with soil formation (P = pedogenesis), followed by a phase with mainly stable land surfaces but some rill / gully erosion (R) and succeeded by intensive erosion and colluviation (E) caused by mainly sheet floods in an more open landscape. Especially during the Metal Ages and High Middle Ages erosion is clearly detectable. In the woodlands strong deforestation took place especially due to the production of charcoal and firewood as well as grazing activities. In addition, the development of mining and related industries in the 15th to 16th centuries and further increase in 19th century produced a strong contamination of floodplain deposits. Different periods of an increasing grassland since Medieval time cause by socio-economic effects that results in a reduction of soil erosion can be distinguished.

  7. Late Miocene paleoenvironment of the Lambert Graben embayment, East Antarctica, evident from: Mollusc paleontology, sedimentology and geochemistry

    NASA Astrophysics Data System (ADS)

    Whitehead, Jason M.; Ehrmann, Werner; Harwood, David M.; Hillenbrand, Claus-Dieter; Quilty, Patrick G.; Hart, Charles; Taviani, Marco; Thorn, Vanessa; McMinn, Andrew

    2006-04-01

    The Upper Miocene (10.7-9.0 Ma) Battye Glacier Formation was deposited ˜250 km inland from the modern Amery Ice Shelf edge in Prydz Bay, East Antarctica. The composition of clay minerals distinguishes a Lower Member, which reflects regional erosion of Precambrian metamorphic basement, from an Upper Member, which records increased erosion of local Permian-Triassic Amery Group strata. The Upper Member was deposited in an ice-proximal environment akin to the modern fjords of East Greenland, with substantial diamict deposition resulting from melting iceberg discharge. The Lower Member was deposited in an ice-distal environment and included the accumulation of the fossil-bearing McLeod Beds. The McLeod Beds contain much siliceous biogenic sediment (≤ 15% opal), which is rare to absent in the predominantly hemipelagic mud of modern East Greenland fjords. The McLeod Beds also contain largely monospecific in situ Hiatella sp. mollusc assemblages suggestive of environmental stress, potentially caused by low salinity melt-water and a high input of terrigenous sediment, which excluded most other benthic taxa. Geochemical results from primary aragonite in Hiatella shells imply large freshwater input into the marine environment during mollusc growth, causing low δ18O, Na, Mg and high Fe values. The present study indicates that iceberg melt-water influence entering the marine environment was greater during the Late Miocene than today around Antarctica, and documents the paleoenvironment associated with a discrete period of ice margin retreat and marine incursion into the Lambert embayment.

  8. Grand and Semigrand Canonical Basin-Hopping

    PubMed Central

    2015-01-01

    We introduce grand and semigrand canonical global optimization approaches using basin-hopping with an acceptance criterion based on the local contribution of each potential energy minimum to the (semi)grand potential. The method is tested using local harmonic vibrational densities of states for atomic clusters as a function of temperature and chemical potential. The predicted global minima switch from dissociated states to clusters for larger values of the chemical potential and lower temperatures, in agreement with the predictions of a model fitted to heat capacity data for selected clusters. Semigrand canonical optimization allows us to identify particularly stable compositions in multicomponent nanoalloys as a function of increasing temperature, whereas the grand canonical potential can produce a useful survey of favorable structures as a byproduct of the global optimization search. PMID:26669731

  9. Rio Grande sediment study -- Supply and transport

    SciTech Connect

    Diniz, E.; Eidson, D.; Bourgeois, M.

    1995-12-31

    The 1992 New Mexico State Legislature directed the Interstate Stream Commission (ISC) to study the feasibility of clearing and deepening the channel of the Rio Grande between Albuquerque and Elephant Butte to improve water conveyance and water conservation. The ISC requested the US Army Corps of Engineers-Albuquerque District (COE) to undertake this study under the Planning Assistance to States Program. The study was divided into two phases. Phase 1 consisted of an analysis of the sediment contribution to the Rio grande from the tributaries and an evaluation of the existing US Geological Survey (USGS) sediment gage data. Phase 2 will be an analysis, through the use of an HEC-6, Scour and Deposition in Rivers and Reservoirs, computer model, to determine the long-term performance of any Rio Grande channel improvements. This narrative presents the Phase 1 methods and results.

  10. 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.

  11. Research Furthers Conservation of Grand Canyon Sandbars

    USGS Publications Warehouse

    Melis, Theodore S.; Topping, David J.; Rubin, David M.; Wright, Scott A.

    2007-01-01

    Grand Canyon National Park lies approximately 25 km (15 mi) down-river from Glen Canyon Dam, which was built on the Colorado River just south of the Arizona-Utah border in Glen Canyon National Recreation Area. Before the dam began to regulate the Colorado River in 1963, the river carried such large quantities of red sediment, for which the Southwest is famous, that the Spanish named the river the Rio Colorado, or 'red river'. Today, the Colorado River usually runs clear below Glen Canyon Dam because the dam nearly eliminates the main-channel sand supply. The daily and seasonal flows of the river were also altered by the dam. These changes have disrupted the sedimentary processes that create and maintain Grand Canyon sandbars. Throughout Grand Canyon, sandbars create habitat for native plants and animals, supply camping beaches for river runners and hikers, and provide sediment needed to protect archaeological resources from weathering and erosion. Maintenance of sandbars in the Colorado River ecosystem, the river corridor that stretches from the dam to the western boundary of Grand Canyon National Park, is a goal of the Glen Canyon Dam Adaptive Management Program. The program is a federally authorized initiative to ensure that the mandates of the Grand Canyon Protection Act of 1992 are met through advances in information and resource management. The U.S. Geological Survey's Grand Canyon Monitoring and Research Center has responsibility for scientific monitoring and research efforts for the program. Extensive research and monitoring during the past decade have resulted in the identification of possible alternatives for operating Glen Canyon Dam that hold new potential for the conservation of sand resources.

  12. Fish Assemblages Associated with Natural and Anthropogenically-Modified Habitats in a Marine Embayment: Comparison of Baited Videos and Opera-House Traps

    PubMed Central

    Wakefield, Corey B.; Lewis, Paul D.; Coutts, Teresa B.; Fairclough, David V.; Langlois, Timothy J.

    2013-01-01

    Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment. PMID:23555847

  13. Distribution of (223)Ra and (224)Ra in the Bo Sea embayment in Tianjin and its implication of submarine groundwater discharge.

    PubMed

    Liu, Lingling; Yi, Lixin; Cheng, Xiaoqing; Tang, Guoqiang

    2015-12-01

    Submarine groundwater discharge (SGD) is now recognized as an important pathway between land and sea. In this study, in order to analyze the distribution of naturally occurring short-lived radium isotopes and the relative SGD effect in Bo Sea embayment, (223)Ra and (224)Ra were measured in three parts of the embayment with the radium-delayed coincidence counting (RaDeCC) system. Subsequently, the mixing process was studied by the calculation of diffusion coefficients (Kx and Kz) and advection velocities (Vx and Vz) based on the 2D advection-diffusion model. Additionally, the apparent residence ages and SGD flux were quantified based on the (224)Ra and (223)Ra activities. The results showed that the Ra activities exponentially decreased with the distance offshore, and both the Kx and Vx took the order of northern part > southern part > middle part. In vertical direction, there was the maximum value of Vz and minimum Kz in middle part and the maximum Kz and minimum Vz in southern part. The average ages for the northern, middle and southern parts were 4.28, 7.38 and 3.73 days, respectively. The final SGD flux yielded by (224)Ra was 0.09, 0.01 and 0.03 m d(-1) in the northern, middle and southern parts, respectively. The SGD flux yielded by (223)Ra was 0.08, 0.01 and 0.03 m d(-1) in northern, middle and southern parts, respectively. The result indicates that there is the fastest exchange rate and the biggest SGD flux in the southern part in Bo Sea embayment.

  14. Distribution of (223)Ra and (224)Ra in the Bo Sea embayment in Tianjin and its implication of submarine groundwater discharge.

    PubMed

    Liu, Lingling; Yi, Lixin; Cheng, Xiaoqing; Tang, Guoqiang

    2015-12-01

    Submarine groundwater discharge (SGD) is now recognized as an important pathway between land and sea. In this study, in order to analyze the distribution of naturally occurring short-lived radium isotopes and the relative SGD effect in Bo Sea embayment, (223)Ra and (224)Ra were measured in three parts of the embayment with the radium-delayed coincidence counting (RaDeCC) system. Subsequently, the mixing process was studied by the calculation of diffusion coefficients (Kx and Kz) and advection velocities (Vx and Vz) based on the 2D advection-diffusion model. Additionally, the apparent residence ages and SGD flux were quantified based on the (224)Ra and (223)Ra activities. The results showed that the Ra activities exponentially decreased with the distance offshore, and both the Kx and Vx took the order of northern part > southern part > middle part. In vertical direction, there was the maximum value of Vz and minimum Kz in middle part and the maximum Kz and minimum Vz in southern part. The average ages for the northern, middle and southern parts were 4.28, 7.38 and 3.73 days, respectively. The final SGD flux yielded by (224)Ra was 0.09, 0.01 and 0.03 m d(-1) in the northern, middle and southern parts, respectively. The SGD flux yielded by (223)Ra was 0.08, 0.01 and 0.03 m d(-1) in northern, middle and southern parts, respectively. The result indicates that there is the fastest exchange rate and the biggest SGD flux in the southern part in Bo Sea embayment. PMID:26318773

  15. Crustal structure of the Southeast Georgia embayment-Carolina trough: Preliminary results of a composite seismic image of a continental suture ( ) and a volcanic passive margin

    SciTech Connect

    Austin, J.A. Jr.; Stoffa, P.L.; Phillips, J.D. ); Oh, Jinyong ); Sawyer, D.S. ); Purdy, G.M.; Reiter, E. ); Makris, J. )

    1990-10-01

    New deep-penetration multichannel seismic reflection data, combined with refraction results and magnetics modeling, support a hypothesis that the Carolina trough is a Mesozoic volcanic passive margin exhibiting a seaward-dipping wedge and associated underplating. The structure of Carolina platform continental crust is consistent with the late Paleozoic continental collision that produced the Appalachians, but imbrication has had no obvious effect on shallower structures produced by Mesozoic extension and volcanism. The origin of prominent magnetic anomalies crossing the Southeast Georgia embayment can be explained by processes attending Mesozoic separation of Africa and North America, and is not related to a Paleozoic continental suture, as previously postulated.

  16. The crustal structure and tectonic development of the continental margin of the Amundsen Sea Embayment, West Antarctica: implications from geophysical data

    NASA Astrophysics Data System (ADS)

    Kalberg, Thomas; Gohl, Karsten

    2014-07-01

    The Amundsen Sea Embayment of West Antarctica represents a key component in the tectonic history of Antarctic-New Zealand continental breakup. The region played a major role in the plate-kinematic development of the southern Pacific from the inferred collision of the Hikurangi Plateau with the Gondwana subduction margin at approximately 110-100 Ma to the evolution of the West Antarctic Rift System. However, little is known about the crustal architecture and the tectonic processes creating the embayment. During two `RV Polarstern' expeditions in 2006 and 2010 a large geophysical data set was collected consisting of seismic-refraction and reflection data, ship-borne gravity and helicopter-borne magnetic measurements. Two P-wave velocity-depth models based on forward traveltime modelling of nine ocean bottom hydrophone recordings provide an insight into the lithospheric structure beneath the Amundsen Sea Embayment. Seismic-reflection data image the sedimentary architecture and the top-of-basement. The seismic data provide constraints for 2-D gravity modelling, which supports and complements P-wave modelling. Our final model shows 10-14-km-thick stretched continental crust at the continental rise that thickens to as much as 28 km beneath the inner shelf. The homogenous crustal architecture of the continental rise, including horst and graben structures are interpreted as indicating that wide-mode rifting affected the entire region. We observe a high-velocity layer of variable thickness beneath the margin and related it, contrary to other `normal volcanic type margins', to a proposed magma flow along the base of the crust from beneath eastern Marie Byrd Land-West Antarctica to the Marie Byrd Seamount province. Furthermore, we discuss the possibility of upper mantle serpentinization by seawater penetration at the Marie Byrd Seamount province. Hints of seaward-dipping reflectors indicate some degree of volcanism in the area after break-up. A set of gravity anomaly data

  17. 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…

  18. 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…

  19. 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…

  20. Subgroup Achievement and Gap Trends: Texas, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Texas for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Texas showed across-the-board gains--improvements in reading and math at the basic, proficient, and advanced levels for all racial/ethnic subgroups, low-income students, and…

  1. 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.…

  2. School Finance Policy Issues in Texas.

    ERIC Educational Resources Information Center

    Sparkman, William E.; Carpenter, Clint

    Just 1 day before a court-imposed deadline of June 1, 1993, Texas Governor Ann Richards signed into law Senate Bill 7 (S.B. 7), the newest version of the Texas school finance system. This paper describes the state's new school finance system with regard to the following: (1) its constitutionality; (2) the provision of a system that equalizes…

  3. Summary of Student Financial Aid in Texas.

    ERIC Educational Resources Information Center

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

    Data on student financial aid in Texas are presented. Tables cover financial aid resources for students in Texas postsecondary institutions by program for 1982-1983, 1984-1985 and 1985-1986. For 17 state aid programs and 6 federal programs, the amount of funding is indicated for the state as a whole and for the following categories of colleges:…

  4. 50 CFR 32.63 - Texas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Texas. 32.63 Section 32.63 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM HUNTING AND FISHING Refuge-Specific Regulations for Hunting and Fishing § 32.63 Texas. The following refuge units have...

  5. 50 CFR 32.63 - Texas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Texas. 32.63 Section 32.63 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM HUNTING AND FISHING Refuge-Specific Regulations for Hunting and Fishing § 32.63 Texas. The following refuge units have...

  6. 50 CFR 32.63 - Texas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Texas. 32.63 Section 32.63 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM HUNTING AND FISHING Refuge-Specific Regulations for Hunting and Fishing § 32.63 Texas. The following refuge units have...

  7. 50 CFR 32.63 - Texas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Texas. 32.63 Section 32.63 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM HUNTING AND FISHING Refuge-Specific Regulations for Hunting and Fishing § 32.63 Texas. The following refuge units have...

  8. 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 Lone Star…

  9. 76 FR 35260 - Texas Disaster # TX-00375

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-16

    ... ADMINISTRATION Texas Disaster TX-00375 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Administrative declaration of a disaster for the State of TEXAS dated 04/26... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  10. 78 FR 39822 - Texas Disaster #TX-00409

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... ADMINISTRATION Texas Disaster TX-00409 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 06/25/2013... CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409 3rd Street...

  11. 75 FR 70763 - Texas Disaster #TX-00363

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... ADMINISTRATION Texas Disaster TX-00363 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 11/09/2010... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  12. 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,…

  13. 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…

  14. 77 FR 24756 - Texas Disaster #TX-00387

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... ADMINISTRATION Texas Disaster TX-00387 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 04/17/2012... adversely affected by the disaster: Primary Counties: Dallas, Kaufman, Tarrant. Contiguous Counties:...

  15. 75 FR 48384 - Texas Disaster #TX-00362

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-10

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Texas Disaster TX-00362 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This... State of TEXAS (FEMA-1931- DR), dated 08/03/2010. Incident: Hurricane Alex. Incident Period:...

  16. 40 CFR 81.429 - Texas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 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...

  17. 40 CFR 81.429 - Texas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 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...

  18. 78 FR 33464 - Texas Disaster #TX-00405

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... ADMINISTRATION Texas Disaster TX-00405 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 05/29/2013... adversely affected by the disaster: Primary Counties: Ellis, Hood, Johnson. Contiguous Counties:...

  19. 75 FR 62437 - Texas Disaster #TX-00364

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-08

    ... ADMINISTRATION Texas Disaster TX-00364 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 09/29/2010... determined to be adversely affected by the disaster: Primary Counties: Nueces, Contiguous Counties:...

  20. Overview: Texas College and Career Readiness Standards

    ERIC Educational Resources Information Center

    Texas Higher Education Coordinating Board, 2009

    2009-01-01

    The Texas College and Career Readiness Standards define what students should know and be able to accomplish in order to succeed in entry-level college courses or skilled workforce opportunities upon graduation from high school. This paper answers the following questions: (1) Who developed the Texas College and Career Readiness Standards?; (2) What…