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Sample records for area southern mexico

  1. Stratigraphic assessment of the Arcelia Teloloapan area, southern Mexico: implications for southern Mexico's post-Neocomian tectonic evolution

    NASA Astrophysics Data System (ADS)

    Cabral-Cano, E.; Lang, H. R.; Harrison, C. G. A.

    2000-10-01

    Stratigraphic assessment of the "Tierra Caliente Metamorphic Complex" (TCMC) between Arcelia and Teloloapan in southern Mexico, based on photo interpretation of Landsat Thematic Mapper images and field mapping at the 1:100,000 scale, tests different tectonic evolution scenarios that bear directly on the evolution of the southern North American plate margin. The regional geology, emphasizing the stratigraphy of a portion of the TCMC within the area between Arcelia and Teloloapan is presented. Stratigraphic relationships with units in adjacent areas are also described. The base of the stratigraphic section is a chlorite grade metamorphic sequence that includes the Taxco Schist, the Roca Verde Taxco Viejo Formation, and the Almoloya Phyllite Formation. These metamorphic units, as thick as 2.7 km, are covered disconformably by a sedimentary sequence, 2.9 km thick, composed of the Cretaceous marine Pochote, Morelos, and Mexcala Formations, as well as undifferentiated Tertiary continental red beds and volcanic rocks. The geology may be explained as the evolution of Mesozoic volcanic and sedimentary environments developed upon attenuated continental crust. Our results do not support accretion of the Guerrero terrane during Laramide (Late Cretaceous-Paleogene) time.

  2. Microbiological and chemical characterization of hydrothermal fluids at Tortugas Mountain Geothermal Area, southern New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Schulze-Makuch, Dirk; Kennedy, John F.

    2000-06-01

    The Tortugas Mountain Geothermal Area is part of the larger hydrothermal system of the Rio Grande Rift, southern New Mexico, USA. Chemical and microbial parameters indicate that the sampled hydrothermal water derives from a mixture zone of deep, anaerobic water with meteoric water from an adjacent alluvial, non-thermal groundwater flow system. A microbial phospholipid fatty acid (PLFA) analysis indicates that biomass and diversity of hydrothermal groundwater are very low, whereas hydrothermal surface water is diverse and bacteria are in a rapid growth phase. A nucleic acid (DNA) analysis of the hydrothermal groundwater resulted in the identification of one eubacterium and two Archaea (archaebacteria); the eubacterium and one Archaea were previously unknown. The one Archaea that could be related to a known species is an extreme halophilic methanomicrobacterium. The presence of the halophilic Archaea and the other Archaea species supports the hypothesis of the Tortugas Mountain Geothermal Area being the discharge area of deep circulating groundwater within a bedrock-hosted regional groundwater flow system.

  3. Bionomics of adult Anopheles pseudopunctipennis (Diptera: Culicidae) in the Tapachula foothills area of southern Mexico.

    PubMed

    Fernandez-Salas, I; Rodriguez, M H; Roberts, D R; Rodriguez, M C; Wirtz, R A

    1994-09-01

    Field studies on the bionomics of adult Anopheles pseudopunctipennis Theobald were conducted to assess its relative importance as a primary vector of vivax malaria in southern Mexico. In four malaria endemic villages in a foothill region near Tapachula, Mexico, population densities of A. pseudopunctipennis increased during the dry seasons of 1990 and 1991. The pattern of nocturnal host-seeking activity indoors was unimodal with a late night peak at 0100 hours enhancing its vectorial significance, because it occurred when most residents were asleep and fully exposed to the anophelines. Comparisons of trapping methods showed that a horse-baited trap was more effective than human landing catches or UV light traps. Pit shelters, on the other hand, were more effective than indoor and natural shelter resting collections. Results of enzyme-linked immunosorbent assays performed on wild-caught A. pseudopunctipennis specimens documented the presence of natural infections with the VK210 and new VK247 circumsporozoite polymorphs of P. vivax. These findings verify the importance of A. pseudopunctipennis as a major vector of vivax malaria at higher elevations and extend the geographical range of the VK247 P. vivax polymorph in Mexico. PMID:7966168

  4. Evolution and hydrocarbon potential of offshore Pinar Del Rio area, Southern Gulf of Mexico

    SciTech Connect

    Tenreyro-Perez, R.; Lopez-Rivera, J.G.; Fernandez-Carmona, J.; Lopez-Quintero, J.O.

    1996-09-01

    The evolution of Southeast Gulf of Mexico comprises three main periods: pre-orogenic, syn-orogenic and post-orogenic. During pre-orogenic time, from Lower Jurassic to Campanian, the stages are the rift of Pangaea and the thermal subsidence (or drift). In drift stage two domains interacted in the space; the carbonate platforms (Bahamas, Yucatan, Organos and others), and the deepwater basins. These fluctuations were dictated by the differential subsidence and horizontal displacements of basement blocks as well as by the eustatic movements of the ocean. The Organos platform, for example, was entirely drowned since Upper Jurassic and the sedimentation continued in deepwater environment. The collision between Great Antilles Volcanic Arc and the continental margins since Upper Cretaceous modeled the Cuban orogen. Here, the southern facies thrusted over the northern section with simultaneous strike-slip movements. The interaction suddenly ceased in Eocene. The source rock levels are considerably more frequent in the deepwater domain than in the platforms. The Lower and Upper Jurassic as well as Lower and Middle Cretaceous horizons contain very high levels of organic matter. The offshore seismic shows the transition from the thrusted belt to the foreland basin with a typical triangle zone configuration. Reservoirs are expected in the Cretaceous section covered by seals conformed by early foreland basin sediments of Upper Cretaceous-Paleocene age. Foothill structures has a great potential for hydrocarbon exploration.

  5. Remote sensing and GIS applied in the definition and zonification of the protected coastal areas in the southern Gulf of Mexico

    SciTech Connect

    Lomeli, D.Z.; Aponte, A.G.; Yanez-Arancibia, A.

    1997-06-01

    The state of Campeche, Mexico is located in the southern part of the Gulf of Mexico. At present Campeche state has two protected areas in its coastal zone: the Terminos Lagoon Area which was declared as a Protected of Flora and Fauna Zone and the Petenes Region which was declared as Special Protected Zone of Flora and Fauna. Considering ecological, socioeconomic and normative criteria along with Landsat-TM satellite images and aerial photographs analyses, overlays of thematic cartography and land surveys, it was defined the borders and ecological zonification of the two protected areas. The ecological zonification includes two zones: Nucleus Zone (restricted protected area) and Buffer Zone (conservation and multiple use area).

  6. Analyses of water and dredged material from selected southern Louisiana waterways and selected areas in the Gulf of Mexico, 1976-78

    USGS Publications Warehouse

    Stallworth, Geraldine R.; Jordan, Helen F.

    1980-01-01

    The U.S. Geological Survey was requested by the U.S. Army Corps of Engineers to provide water-quality data to evaluate the potential environmental effects of (1) dredging activities in selected navigable waterways of southern Louisiana and (2) the disposal of dredged material at selected areas in the Gulf of Mexico. Areas studied from September 1976 to May 1978 included five ocean disposal sites in the Gulf of Mexico, in addition to the following waterways: Baptiste, Collette Bayou, Mississippi River at Head of Passes and Southwest Pass, Mississippi River at Tiger Pass, Bayou Black, Intracoastal Waterway (Port Allen to Morgan City), and Calcasieu River and Ship Channel. Samples were analyzed for selected chemical, physical, and biological constituents. (USGS)

  7. Anopheles albimanus (Diptera: Culicidae) host selection patterns in three ecological areas of the coastal plains of Chiapas, southern Mexico.

    PubMed

    Loyola, E G; González-Cerón, L; Rodríguez, M H; Arredondo-Jiménez, J I; Bennett, S; Bown, D N

    1993-05-01

    The host-feeding patterns of Anopheles albimanus Wiedemann were described and the effect of host availability on these patterns was assessed in three different ecological areas of coastal Chiapas, Mexico. Resting mosquitoes were collected indoors and outdoors during rainy seasons. A 20% sample of blood-fed mosquitoes was tested to determine the source of the blood meal using an ELISA. The unweighted human blood index (HBI) of An. albimanus in the three areas ranged from 0.11 to 0.21. This mosquito species fed more frequently on bovines than on any other host, but the forage ratio indicated that there was also a high preference for equines. Some females tended to rest or complete their gonotrophic cycle indoors after feeding on animals, but females also fed on man and rested outdoors. Host availability and ecological conditions appeared to be responsible for differences observed in the HBI among areas. PMID:8510111

  8. Comparative age and growth of common snook Centropomus undecimalis (Pisces: Centropomidae) from coastal and riverine areas in Southern Mexico.

    PubMed

    Perera-Garcia, Martha A; Mendoza-Carranza, Manuel; Contreras-Sánchez, Wilfrido; Ferrara, Allyse; Huerta-Ortiz, Maricela; Hernández-Gómez, Raúl E

    2013-06-01

    Common snook Centropomus unidecimalis is an important commercial and fishery species in Southern Mexico, however the high exploitation rates have resulted in a strong reduction of its abundances. Since, the information about its population structure is scarce, the objective of the present research was to determine and compare the age structure in four important fishery sites. For this, age and growth of common snook were determined from specimens collected monthly, from July 2006 to March 2008, from two coastal (Barra Bosque and Barra San Pedro) and two riverine (San Pedro and Tres Brazos) commercial fishery sites in Tabasco, Mexico. Age was determined using sectioned saggitae otoliths and data analyzed by von Bertalanffy and Levenberg-Marquardt among others. Estimated ages ranged from 2 to 17 years. Monthly patterns of marginal increment formation and the percentage of otoliths with opaque rings on the outer edge demonstrated that a single annulus was formed each year. The von Bertalanffy parameters were calculated for males and females using linear adjustment and the non-linear method of Levenberg-Marquardt. The von Bertalanffy growth equations were FLt = 109.21(1-e-0.2(t+0.57)) for Barra Bosque, FLt = 94.56(1-e-027(t+0.485)) for Barra San Pedro, FLt = 97.15(1-e 0.17(t + 1.32)) for San Pedro and FLt = 83.77(1-e-026(t + 0.49)) for Tres Brazos. According to (Hotelling's T2, p < 0.05) test growth was significantly greater for females than for males. Based on the Chen test, von Bertalanffy growth curves were different among the study sites (RSS, p < 0.05). Based on the observed differences in growth parameters among sampling sites (coastal and riverine environments) future research need to be conducted on migration and population genetics, in order to delineate the stock structure of this population and support management programs. PMID:23885591

  9. Dynamics of population densities and vegetation associations of Anopheles albimanus larvae in a coastal area of southern Chiapas, Mexico.

    PubMed

    Rodríguez, A D; Rodríguez, M H; Meza, R A; Hernández, J E; Rejmankova, E; Savage, H M; Roberts, D R; Pope, K O; Legters, L

    1993-03-01

    Spatial and seasonal variations on Anopheles albimanus larval densities and their plant associations were investigated in larval habitats in southern Mexico between April 1989 and May 1990. Thirty-four plant groups were dominant in larval habitats. Dense larval populations were associated with 3 genera of plants, Cynodon, Echinocloa and Fimbristylis and no larvae were found in habitats with Salvinia and Rhizophora. Low significant positive or negative associations were documented with the other 12 plant genera. Larval habitats were classified according to the morphology of their dominant plants. Higher larval densities were observed in the groups characterized by relatively short emergent vegetation. The distribution of habitat-types within 5 identified vegetation units showed a significantly dependent relationship. For the entire study period, highest larval densities were detected in flooded pasture/grassland vegetation units. For all vegetation units, higher larval densities were found when the dominant plant type covered between 25-50% of the breeding site. The integration of data from habitat-types into vegetation units did not result in loss of information. PMID:8468574

  10. Stray dogs as reservoirs of the zoonotic agents Leptospira interrogans, Trypanosoma cruzi, and Aspergillus spp. in an urban area of Chiapas in southern Mexico.

    PubMed

    Jimenez-Coello, Matilde; Ortega-Pacheco, Antonio; Guzman-Marin, Eugenia; Guiris-Andrade, Dario M; Martinez-Figueroa, Laura; Acosta-Viana, Karla Y

    2010-03-01

    This investigation determined the presence and prevalence of the zoonotic agents Leptospira interrogans, Trypanosoma cruzi, and Aspergillus spp. in the stray dog population (a total of 224 stray dogs) in an urban area of Southern Mexico. Blood serum samples were taken from all dogs, and root hair samples were taken from dogs with skin lesions and partial alopecia. IgG antibodies for L. interrogans from 10 serovars were detected using the microscopic agglutination test. Immunofluorescence antibody test and Western blot assay were used for serologic diagnosis of T. cruzi. The Sabouraud medium was used to isolate Aspergillus spp. Prevalence of L. interrogans was 4.9%, which was determined by identifying only serovars Pyrogenes, which accounted for 3.6%, and Tarassovi, which constituted 1.3%, with titers from 1:100 to 1:800. Additionally, T. cruzi antibodies were detected in 4.5% of the dogs. Skin lesions were found in 43% of the dogs (98/224), and 35 cultures were positive for Aspergillus spp. (35.7%, p < 0.05, 95% confidence interval 2.45-3.67), identified as A. niger (82.8%), A. flavus (14.3%), and A. terreus (2.9%). This study demonstrates the presence of certain zoonotic agents (bacteria, protozoa, and fungi) in stray dogs living within the studied area. Dogs play an important role in the transmission of diseases that are potentially harmful to humans. Although the prevalence of canine leptospirosis and trypanosomiasis is not high in Southern Mexico compared with other tropical regions of Mexico, the presence of these zoonotic agents in the stray dog population demonstrates that the stray dog population in this region is a significant reservoir and potential source of infection in humans. Special care should be taken when handling stray dogs that exhibit skin lesions with partial alopecia, since a pathological Aspergillus sp. fungus may be present. PMID:19514808

  11. Tuberculosis Treatment Completion Rates in Southern New Mexico Colonias.

    PubMed

    Holden, Maria Arroyo; Huttlinger, Kathleen; Schultz, Pamela; Mullins, Iris; Forster-Cox, Sue

    2016-04-01

    TB medication completion treatment rates for active TB patients living in impoverished US-Mexico border communities called colonias in southern New Mexico counties are unknown. It might be suspected that residents of colonias have lower completion rates than those living in incorporated and medically more accessible areas. A retrospective record review of closed TB case records from 1993 to 2010 of southern New Mexico border counties, was conducted using a modified version of the New Mexico Department of Health Tuberculosis Targeted Health Assessment/History form (Appendix 1). Study findings reveal that despite their unincorporated status, poorer living conditions and questionable legal status, colonia TB patients had a higher medication completion rate than their non-colonia counterparts. A robust New Mexico TB treatment program contributed to high completion rates with death being the number-one reason for treatment non-completion in both colonia and non-colonias. PMID:25929762

  12. Gonotrophic cycle and survivorship of Anopheles vestitipennis (Diptera: Culicidae) in two different ecological areas of southern Mexico.

    PubMed

    Arredondo-Jiménez, J I; Rodríguez, M H; Washino, R K

    1998-11-01

    The duration of the gonotrophic cycle and survivorship of Anopheles vestitipennis Dyar & Knab was estimated in 2 malarious areas of Chiapas, Mexico: the Lacandon Forest and the Pacific Ocean Coastal Plain. Blood-engorged females held in an outdoor cage required 2.75 d for egg maturation, and 3.75 d for the duration of the gonotrophic cycle. Duration of the gonotrophic cycle also was estimated by parous-nulliparous dynamics for 20 consecutive days and autocorrelation time-series analysis, and by mark-recapture techniques. These methods depicted differences between the Lacandon Forest (3-d cycle) and the Coastal Plain (2-3 d cycles). Daily survival rates were estimated vertically and were generally higher in the Lacandon Forest (0.68) than in the Coastal Plain (0.45-0.58). The probability of mosquitoes surviving the sporogonic cycle was 10-100 times greater in the Lacandon Forest. The pregravid rate was 8.2%, and 29.3% of females with primary follicles beyond Christophers' stage III had traces of red blood in the gut. The 1st statistic indicated that 8.2% of females required > 1 blood meal for initial egg development, the 2nd statistic indicated that 29.3% of females take > 1 blood meal during a gonotrophic cycle. In summary, the enhanced vectorial role of this species is explained partially by high longevity and multiple blood-feeding habits. PMID:9835683

  13. Smoke from Fires in Southern Mexico

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 2, 2002, numerous fires in southern Mexico sent smoke drifting northward over the Gulf of Mexico. These views from the Multi-angle Imaging SpectroRadiometer illustrate the smoke extent over parts of the Gulf and the southern Mexican states of Tabasco, Campeche and Chiapas. At the same time, dozens of other fires were also burning in the Yucatan Peninsula and across Central America. A similar situation occurred in May and June of 1998, when Central American fires resulted in air quality warnings for several U.S. States.

    The image on the left is a natural color view acquired by MISR's vertical-viewing (nadir) camera. Smoke is visible, but sunglint in some ocean areas makes detection difficult. The middle image, on the other hand, is a natural color view acquired by MISR's 70-degree backward-viewing camera; its oblique view angle simultaneously suppresses sunglint and enhances the smoke. A map of aerosol optical depth, a measurement of the abundance of atmospheric particulates, is provided on the right. This quantity is retrieved using an automated computer algorithm that takes advantage of MISR's multi-angle capability. Areas where no retrieval occurred are shown in black.

    The images each represent an area of about 380 kilometers x 1550 kilometers and were captured during Terra orbit 12616.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  14. Rain Rate Statistics in Southern New Mexico

    NASA Technical Reports Server (NTRS)

    Paulic, Frank J., Jr.; Horan, Stephen

    1997-01-01

    The methodology used in determining empirical rain-rate distributions for Southern New Mexico in the vicinity of White Sands APT site is discussed. The hardware and the software developed to extract rain rate from the rain accumulation data collected at White Sands APT site are described. The accuracy of Crane's Global Model for rain rate predictions is analyzed.

  15. Geochronology, structural evolution of the Tierra Colorada area, and tectonic implications for southern Mexico and Chortís block connections

    NASA Astrophysics Data System (ADS)

    Solari, L. A.; Torres de Leon, R.; Hernandez Pineda, G.; Sole', J.; Solis Pichardo, G.; Hernandez Treviño, T.

    2006-05-01

    The Tierra Colorada area is considered the best exposure of the northern limit between the Xolapa Complex and the Paleozoic-Precambrian Mixteca and Zapotecan terranes of southern Mexico. Geochemistry (major, trace, and REE) and geochronology on deformed granitoids in Tierra Colorada area show evidence of subduction-related magmatism during Mesozoic and Cenozoic. El Pozuelo granite, dated at 129 Ma (concordant U-Pb single-zircon age) is a foliated body, with local porphyric facies. Foliation is penetrative and characterized by oriented micas and stretched quartz. Geochemically it shows a metaluminous character, with arc-related trace and REE patterns. Because it cuts across high-grade gneisses of the Xolapa Complex, its intrusion postdates the second phase of metamorphism in the Xolapa Complex (> 130 Ma), which generated the orthogneisses-migmatites sequence. El Salitre granite (55 Ma, Rb-Sr 4 point isochron) is a foliated peraluminous body with a pronounced negative Zr anomaly. The protomylonitic Las PiÑas granite (54 +/- 6 Ma, U-Pb lower intercept) is characterized by ductile fabric, recognized by cinematic indicators such as mica fish, and indicates a top-to-the NNW sense of shear, dated at 50 +/- 1 Ma and 45.3 +/- 2 Ma (K-Ar on Bt, and Rb-Sr Bt-WR isochron, respectively), ages that indicate the time of ductile deformation along La Venta shear zone, as N-dipping detachment under low greenschist facies conditions. El Salitre and Las PiÑas granites are linked because of their similar HREE patterns. The Tierra Colorada, Xaltianguis and San Juan del Reparo granites, with calcalkaline subduction-related geochemistry, lack of penetrative deformation, and their ages of 30-34 Ma (U-Pb on zircons) constitute the last recognized granitic pulse in this area, post-dating the S-verging thrust of the Morelos limestones on top of sheared granites and volcanics. Together with previously published ages of magmatism in the studied area, we demonstrate here that calcalkaline

  16. Final report to DOE [Global guardianship initiative in southern Mexico

    SciTech Connect

    2000-07-01

    The objective of this project is to establish models for community renewable energy deployment as a strategy for protected area management and an alternative to grid extension in developing countries in Latin America and Asia. Working together with the Nature Conservancy, the Center for Resource Solutions chose Southern Mexico and its 10 protected areas to launch this program. DOE funds supported Phase One activities: establishment of an advisory committee and selection of six to ten communities for renewable energy plans.

  17. Naturally acidic surface and ground waters draining porphyry-related mineralized areas of the Southern Rocky Mountains, Colorado and New Mexico

    USGS Publications Warehouse

    Verplanck, P.L.; Nordstrom, D.K.; Bove, D.J.; Plumlee, G.S.; Runkel, R.L.

    2009-01-01

    Acidic, metal-rich waters produced by the oxidative weathering and resulting leaching of major and trace elements from pyritic rocks can adversely affect water quality in receiving streams and riparian ecosystems. Five study areas in the southern Rocky Mountains with naturally acidic waters associated with porphyry mineralization were studied to document variations in water chemistry and processes that control the chemical variations. Study areas include the Upper Animas River watershed, East Alpine Gulch, Mount Emmons, and Handcart Gulch in Colorado and the Red River in New Mexico. Although host-rock lithologies in all these areas range from Precambrian gneisses to Cretaceous sedimentary units to Tertiary volcanic complexes, the mineralization is Tertiary in age and associated with intermediate to felsic composition, porphyritic plutons. Pyrite is ubiquitous, ranging from ???1 to >5 vol.%. Springs and headwater streams have pH values as low as 2.6, SO4 up to 3700 mg/L and high dissolved metal concentrations (for example: Fe up to 400 mg/L; Cu up to 3.5 mg/L; and Zn up to 14.4 mg/L). Intensity of hydrothermal alteration and presence of sulfides are the primary controls of water chemistry of these naturally acidic waters. Subbasins underlain by intensely hydrothermally altered lithologies are poorly vegetated and quite susceptible to storm-induced surface runoff. Within the Red River study area, results from a storm runoff study documented downstream changes in river chemistry: pH decreased from 7.80 to 4.83, alkalinity decreased from 49.4 to <1 mg/L, SO4 increased from 162 to 314 mg/L, dissolved Fe increased from to 0.011 to 0.596 mg/L, and dissolved Zn increased from 0.056 to 0.607 mg/L. Compared to mine drainage in the same study areas, the chemistry of naturally acidic waters tends to overlap but not reach the extreme concentrations of metals and acidity as some mine waters. The chemistry of waters draining these mineralized but unmined areas can be used to

  18. 75 FR 30772 - Southern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... Forest Service Southern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Southern New Mexico Resource Advisory Committee will meet in Socorro, New Mexico. The committee is meeting as authorized under the Secure Rural Schools and Community...

  19. 75 FR 69916 - Southern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... Forest Service Southern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Southern New Mexico Resource Advisory Committee (RAC) will meet in Socorro, New Mexico. The committee is meeting as authorized under the Secure Rural Schools and...

  20. 76 FR 46722 - Southern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-03

    ... Forest Service Southern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Southern New Mexico Resource Advisory Committee will meet in Socorro, New Mexico. The committee is authorized under the Secure Rural Schools and Community Self-Determination...

  1. 75 FR 39655 - Southern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... Forest Service Southern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Southern New Mexico Resource Advisory Committee (RAC) will meet in Socorro, New Mexico. The committee is meeting as authorized under the Secure Rural Schools and...

  2. 77 FR 49776 - Southern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Forest Service Southern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Southern New Mexico Resource Advisory Committee will meet in Socorro, New Mexico. The purpose of the committee is to improve collaborative relationships and to provide advice...

  3. 76 FR 16603 - Southern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-24

    ... Forest Service Southern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Southern New Mexico Resource Advisory Committee (RAC) will meet in Socorro, New Mexico. The committee is meeting as authorized under the Secure Rural Schools and...

  4. Tectonic Significance of Cretaceous to Tertiary Magmatic and Structural Evolution of the Northern Portion of the Xolapa Complex, Tierra Colorada-Acapulco Area, Southern Mexico

    NASA Astrophysics Data System (ADS)

    Torres de Leon, R.; Perez, R.; Solari, L.; Hernandez, G.; Sole, J.; Solis, G.; Hernandez, T.

    2007-05-01

    middle Cretaceous. The stable conditions during deposition of the Morelos Formation may have resulted from a combination of back-arc extension and development of a passive margin during the Middle Cretaceous, which postdated the accretion of an exotic block, either the Guerrero terrane or the Chortís block. Following the Laramide Orogeny in southern Mexico (roughly during the Late Cretaceous) the Paleocene to Miocene tectonic evolution is represented by an alternation of magmatic pulses with contractile and extensional events, which are the result of a combination of several factors such as the geometry of the subducted slab, convergence rate, stress transmission between subducting and overlying plate, as well as to the rate of subduction erosion.

  5. Burnt Area Mapping in Mexico

    NASA Astrophysics Data System (ADS)

    Cruz Lopez, M.; López Saldaña, G.

    2013-05-01

    The Fire Early Warning System was implemented in 2012 as a follow up of the wildfire identification started in 1999. The system has three components: the early warning, monitoring and assessment. The latter stage has as a main objective to provide as soon as possible, sensible information to the Mexican Forestry National Commission, additionally this data is the base of a long term vegetation monitoring. The burnt area identification is based on the Moderate Resolution Imaging Spectroradiometer (MODIS) data that is received in the Direct Readout station, the algorithm uses daily surface reflectance produced operationally. The core of the algorithm is the pre- and post-fire surface reflectance inter-comparison, in order to flag a pixel as burnt, several conditions have to be true; fuel must be available before the fire, a significant change in the Normalized Burt Ratio (NBR) must exists and a temporal persistency of the change is finally assess. There are different thresholds for the aforementioned conditions based on the land cover in Mexico. The algorithm is applied only in selected pixels that fulfill strict criteria, e.g., 100% cloud free, not contaminated by aerosols and with a view zenith angle lower that 45o. Furthermore, a downscaling was applied to enhance the spatial resolution, 500m to 250m, of the 2.1μm shortwave infrared band using the spectral information of the red band at 250m, the SWIR is useful to identified burnt areas as was used to compute the NBR. This paper presents the foundation and first results of the burnt area algorithm towards an operational implementation as part of the Fire Early Warning System in Mexico.

  6. Lower Mississippian trilobites from southern New Mexico

    USGS Publications Warehouse

    Brezinski, D.K.

    2000-01-01

    Twenty-three species of trilobites are recognized in the lower Mississippian Caballero and Lake Valley Formations of southern New Mexico. Species exhibit a segregation into shelf and off-shelf faunas, and can be subdivided into three distinct stratigraphic faunas. Species found in the Caballero Formation are similar to those found in the Chouteau Formation of Missouri. A second fauna, comprising species found in the Alamogordo, Nunn, and Tierra Blanca Members of the Lake Valley Formation, is correlated with the Fern Glen and Burlington Formations of Missouri. The third fauna found in the Arcente and Dona Aha Members of the Lake Valley Formation is correlated with the Warsaw and Salem Formations of the United States midcontinent region. Named species from the Kinderhookian Caballero Formation include: Dixiphopyge armata (Vogdes, 1891), Comptonaspis swallowi (Shumard, 1855), Brachymetopus indianwellsensis new species, Ameropiltonia perplexa new species, Griffithidella caballeroensis new species, and Kollarcephalus granatai new genus and new species. Named species from the Lake Valley Formation include: Pudoproetus fernglenensis (Weller, 1909), Breviphillipsia semiteretis Hessler, 1963, Griffithidella doris (Hall 1860), Phillibole planucauda (Brezinski, 1998), Piltonia carlakertisae new species, Australosutura llanoensis Brezinski, 1998, Thigriffides triangulatus new species, Thigriffides? alamogordoensis new species, Namuropyge newmexicoensis new species, Nunnaspis stitti new genus and new species, Hesslerides arcentensis new genus and new species, as well as an unnamed species of Proetides Hessler, 1962, Namuropyge Brezinski, 1988, and Thigriffides Hessler, 1965.

  7. Paleomagnetism of the Cretaceous Morelos and Mezcala Formations, southern Mexico

    NASA Astrophysics Data System (ADS)

    Molina Garza, Roberto S.; Böhnel, Harald N.; Hernández, Teodoro

    2003-01-01

    A paleomagnetic study of platform-facies carbonate rocks of the mid-Cretaceous Morelos Formation and deep-water carbonate rocks of the overlying Upper Cretaceous Mezcala Formation, sampled at Zopilote canyon, in Guerrero State, southern Mexico, indicates that their characteristic magnetization was acquired contemporaneously with folding of these rocks during the Late Cretaceous Laramide orogeny. The remanence carrier is interpreted to be magnetite, although other mineral phases of high coercivity carry recent secondary overprints. The overall mean is of Dec=323.1° and Inc=36.5° ( k=162.7; α95=2.7°; N=18 sites; 64% unfolding). Comparison with the North America reference direction indicates that this area has experienced a small, yet statistically significant, counterclockwise direction of 19.2±4.0°. Similar rotations are documented in other localities from southern Mexico; rotations are linked to mid-Tertiary deformation associated with the left-lateral strike-slip fault system that accommodated motion of the Chortis and Xolapa blocks.

  8. Laramide block uplifts and complementary basins in southern New Mexico

    SciTech Connect

    Mack, G.H.; Seager, W.R.

    1988-01-01

    During the Laramide orogeny the foreland area of south-central and southwestern New Mexico was broken into several major, basement-cored, block uplifts and complementary basins. Geometry of the structures is similar in overall style to the Wind River and Owl Creek uplifts and Wind River basin of Wyoming. The southern New Mexico uplifts trend uniformly northwesterly and are asymmetric: they have narrow thrust- or reverse-faulted northeastern margins and much broader, gently dipping southwestern flanks. The sense of tectonic transport is toward the northeast with few exceptions. Complementary basins are filled with as much as 2100 m (6800 ft) of synorogenic and postorogenic clastic strata. The postorogenic strata, essentially of Eocene age, overlap and partly bury the uplifts, and the strata record erosional unroofing of the uplifts, locally down the Precambrian. In southwestern New Mexico, uplift-boundary thrust and reverse faults probably have an important component of right- and/or left-lateral slip. Complex structure along these faults, including low-angle thrust faulting, may be a product of convergent wrench faulting.

  9. Area Handbook for Mexico. First Edition.

    ERIC Educational Resources Information Center

    Ryan, John Morris; And Others

    This volume on Mexico is one of a series of handbooks prepared by the Foreign Area Studies (FAS) of the American University. It is designed to be useful to military and other personnel who need a convenient compilation of basic facts about the social, economic, political, and military institutions and practices of Mexico. The emphasis is on…

  10. Evidence of incipient forest transition in Southern Mexico.

    PubMed

    Vaca, Raúl Abel; Golicher, Duncan John; Cayuela, Luis; Hewson, Jenny; Steininger, Marc

    2012-01-01

    Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing

  11. Evidence of Incipient Forest Transition in Southern Mexico

    PubMed Central

    Vaca, Raúl Abel; Golicher, Duncan John; Cayuela, Luis; Hewson, Jenny; Steininger, Marc

    2012-01-01

    Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990–2000 period to 0.67% in the 2000–2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing

  12. 40 CFR 81.99 - New Mexico Southern Border Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false New Mexico Southern Border Intrastate... Designation of Air Quality Control Regions § 81.99 New Mexico Southern Border Intrastate Air Quality Control Region. The Arizona-New Mexico Southern Border Interstate Air Quality Control Region has been renamed...

  13. 40 CFR 81.99 - New Mexico Southern Border Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false New Mexico Southern Border Intrastate... Designation of Air Quality Control Regions § 81.99 New Mexico Southern Border Intrastate Air Quality Control Region. The Arizona-New Mexico Southern Border Interstate Air Quality Control Region has been renamed...

  14. 40 CFR 81.99 - New Mexico Southern Border Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false New Mexico Southern Border Intrastate... Designation of Air Quality Control Regions § 81.99 New Mexico Southern Border Intrastate Air Quality Control Region. The Arizona-New Mexico Southern Border Interstate Air Quality Control Region has been renamed...

  15. 40 CFR 81.99 - New Mexico Southern Border Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false New Mexico Southern Border Intrastate... Designation of Air Quality Control Regions § 81.99 New Mexico Southern Border Intrastate Air Quality Control Region. The Arizona-New Mexico Southern Border Interstate Air Quality Control Region has been renamed...

  16. 40 CFR 81.99 - New Mexico Southern Border Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false New Mexico Southern Border Intrastate... Designation of Air Quality Control Regions § 81.99 New Mexico Southern Border Intrastate Air Quality Control Region. The Arizona-New Mexico Southern Border Interstate Air Quality Control Region has been renamed...

  17. Upper Mantle Discontinuities Underneath Central and Southern Mexico

    NASA Astrophysics Data System (ADS)

    Perez-Campos, X.; Clayton, R. W.

    2011-12-01

    Central and southern Mexico are affected by the subduction of Cocos plate beneath North American plate. The MesoAmerican Subduction Experiment (MASE) and the Veracruz-Oaxaca (VEOX) project have mapped the geometry of the Cocos slab. It is characterized in central Mexico by a shallow horizontal geometry up to ~300 km from the trench, then it dives steeply (70°) into the mantle, to its apparent end at 500 km depth. In contrast, some 400 km to the south, the slab subducts smoothly, with a dip angle of ~26° to a depth of 150 km. We use receiver functions from teleseismic events, recorded at stations from MASE, VEOX, and the Servicio Sismológico Nacional (SSN, Mexican National Seismological Service) to map the upper mantle discontinuities and properties of the transition zone in central and southern Mexico. We also use data from the Mapping the Rivera Subduction Zone (MARS) Experiment to get a complete picture of the subduction regime in central Mexico and compare the mantle transition zone in a slab tear regime. The 410 discontinuity shows significant variation in topography in central Mexico, particularly where the slab is expected to reach such depth. The 660 discontinuity shows a smoother topography, indicating that the slab does not penetrate this far down. The results will be compared with a ridge regime in the Gulf of California.

  18. Results of a Two-Year Pink Bollworm Survey in the Southern Plains of Texas and New Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton producing areas in the Southern Plains Region of Texas and New Mexico were surveyed using delta sticky traps baited with gossyplure, the sex pheromone for pink bollworm (PBW). Non-cotton producing areas south of these areas were also surveyed for moths potentially moving into the El Paso/Tra...

  19. GUADALUPE ESCARPMENT WILDERNESS STUDY AREA, NEW MEXICO.

    USGS Publications Warehouse

    Hayes, Philip T.; Thompson, John R.

    1984-01-01

    A mineral-resource survey of the Guadalupe Escarpment Wilderness Study Area in New Mexico indicates little possibility for the occurrence of metallic mineral resources. The area is underlain by thousands of feet of sedimentary rock that could contain either stratigraphic or structural oil and (or) gas traps. The oil and gas resource potential is assessed to be probable, but cannot be conclusively known before several exploratory holes have been drilled in the area.

  20. Analysis of gravity data in Central Valleys, Oaxaca, southern, Mexico

    NASA Astrophysics Data System (ADS)

    Gonzalez, T.; Ferrusquia, I.

    2015-12-01

    The region known as Central Valleys is located in the state of Oaxaca, southern, Mexico (16.3o- 17.7 o N Lat. and 96 o - 97 o W Long.) In its central portion is settled the capital of the state. There are very few published detailed geological studies.. Geomorphological and geological features, indicates that Central Valleys and surrounding mountains conform a graben structure. Its shape is an inverted Y, centred on Oaxaca City. The study area was covered by a detailed gravity survey with a homogenous distribution of stations. The Bouguer gravity map is dominated by a large gravity low, oriented NW-SE. In order to know the characteristics of anomalies observed gravity, data transformations were used. The use of spectral methods has increased in recent years, especially for the estimation of the depth of the source. Analysis of the gravity data sheds light on the regional depth of the Graben basement and the spatial distribution of the volcanic rocks

  1. Venezuelan Equine Encephalitis Virus, Southern Mexico

    PubMed Central

    Estrada-Franco, José G.; Navarro-Lopez, Roberto; Freier, Jerome E.; Cordova, Dionicio; Clements, Tamara; Moncayo, Abelardo; Kang, Wenli; Gomez-Hernandez, Carlos; Rodriguez-Dominguez, Gabriela; Ludwig, George V.

    2004-01-01

    Equine epizootics of Venezuelan equine encephalitis (VEE) occurred in the southern Mexican states of Chiapas in 1993 and Oaxaca in 1996. To assess the impact of continuing circulation of VEE virus (VEEV) on human and animal populations, serologic and viral isolation studies were conducted in 2000 to 2001 in Chiapas State. Human serosurveys and risk analyses indicated that long-term endemic transmission of VEEV occurred among villages with seroprevalence levels of 18% to 75% and that medical personnel had a high risk for VEEV exposure. Seroprevalence in wild animals suggested cotton rats as possible reservoir hosts in the region. Virus isolations from sentinel animals and genetic characterizations of these strains indicated continuing circulation of a subtype IE genotype, which was isolated from equines during the recent VEE outbreaks. These data indicate long-term enzootic and endemic VEEV circulation in the region and continued risk for disease in equines and humans. PMID:15663847

  2. Analyses of native water, bottom material, elutriate samples, and dredged material from selected southern Louisiana waterways and selected areas in the Gulf of Mexico, 1979-81

    USGS Publications Warehouse

    Lurry, Dee L.

    1983-01-01

    The U.S. Geological Survey was requested by the U.S. Army Corps of Engineers, New Orleans District, to provide water-quality data to evaluate environmental effects of dredging activities in selected reaches of the Calcasieu River in southwestern Louisiana. Samples were collected from the upper and lower Calcasieu River between January 1980 and March 1981. Thirty-three samples (22 native-water and 11 effluent) were collected from eleven dredging sites. In addition, a series of elutriate studies were conducted between July 1979 and July 1981 to determine water quality as a basis for assessing possible environmental effects of proposed dredging activities in the following areas: Grand Bayou and Martins Canal near Happy Jack, unnamed bayou near Port Sulphur, Grand Bayou and Pipeline Canal near Port Sulphur and Bayou des Plantins near Empire; Mississippi River Gulf Outlet and Inner Harbor Navigation Canal; Southwest Pass; Barataria Bay; Atchafalaya Bay at Eugene Island; Calcasieu Ship Channel. Samples of native water and samples of bottom material were collected from 22 different sites and elutriate (mixtures of native water and bottom material) samples were prepared and analyzed. Four proposed ocean-disposal sites were sampled for bottom material only. Samples were analyzed for selected chemical and biological constituents and physical properties. (USGS)

  3. CABALLO AND POLVADERA ROADLESS AREAS, NEW MEXICO.

    USGS Publications Warehouse

    Manley, Kim; Lane, Michael

    1984-01-01

    A mineral-resource survey has been conducted for the Caballo and Polvadera Roadless Areas, Los Alamos and Rio Arriba Counties, New Mexico. The rocks in the study areas are chiefly volcanic with minor volcaniclastic sedimentary rocks. There is little promise for the occurrence of mineral or fossil fuel resources in the areas. There has been no mining activity within the roadless areas and chemical analyses of stream-sediment samples show no significant anomalous concentrations of metals. There has been some interest in geothermal resources near the Polvadera Roadless Area and a KGRA (Known Geothermal Resource Area) extends into the southwestern corner of the area. This area has been classified as having probable geothermal-resource potential.

  4. BLACK RANGE PRIMITIVE AREA, NEW MEXICO.

    USGS Publications Warehouse

    Ericksen, George E.; Leland, George R.

    1984-01-01

    A study of the Black Range Primitive Area, New Mexico indicated that the area had little promise for the occurrence of mineral resources. A few miles north of the area, a unit of rhyolite in the otherwise barren volcanic rocks of the Mogollon-Datil volcanic field contains local concentrations of the tin mineral cassiterite, and streams draining outcrop areas of this rhyolite within the primitive area may contain very small cassiterite placer deposits. None were observed in this study and no resource potential was identified. Paleozoic sedimentary rocks and Precambrian granitic and metamorphic rocks exposed just east and south of the primitive area contain small polymetallic deposits with varying amounts of silver, lead, zinc, copper, and gold. These same rocks lie beneath the volcanic cover within the primitive area and are likely to contain similar deposits, but no resource potential was identified.

  5. Innate host selection in Anopheles vestitipennis from southern Mexico.

    PubMed

    Ullo, Armando; Arredondo-Jiménez, Juan I; Rodríguez, Mario H; Fernández-Salas, Ildefonso; González-Cerón, Lilia

    2004-12-01

    We assessed the degree of host specificity of the purported anthropophilic and zoophilic populations of Anopheles vestitipennis. A series of experiments were conducted in an experimental hut with 3 compartments lined with nylon netting. A central release compartment and 2 side compartments were each baited with equivalent surface area of human and animal baits. Wild An. vestitipennis collected on each host, as well as corresponding F1 mosquitoes, were released in the central compartment. Overall, 22% (166/748) of all mosquitoes collected on humans were recaptured in the human compartment, whereas 23% of mosquitoes originally collected on animals were recaptured in this compartment. Experiments with F1 females resulted in 59% human selection rates, a 2.6 times increase compared with wild anthropophilic females, while a 1.2 times decrease in human selection rates (from 24% to 20%) was observed in F1 of wild zoophilic females. Host selection experiments in the Lacandón Forest revealed the same trend. These findings suggested that the complex mode of inheritance that resulted in female mosquitoes showing a stronger tendency to return to their preferred host was obscured by the nature of the method of collection, i.e., wild parental females selecting a host either innately or opportunistically, the majority of which were likely innately attracted. This was revealed by F1 females, of which, when given the choice to select a host, a higher proportion opted for the preferred one. The results presented here are in accordance with other studies that identified a subpopulation of An. vestitipennis in southern Mexico with higher anthropophily. PMID:15669372

  6. Jaguar taxonomy and genetic diversity for southern Arizona, United States, and Sonora, Mexico

    USGS Publications Warehouse

    Culver, Melanie; Hein, Alexander Ochoa

    2016-01-01

    Executive SummaryThe jaguar is the largest Neotropical felid and the only extant representative of the genus Panthera in the Americas. In recorded history, the jaguars range has extended from the Southern United States, throughout Mexico, to Central and South America, and they occupy a wide variety of habitats. A previous jaguar genetic study found high historical levels of gene flow among jaguar populations over broad areas but did not include any samples of jaguar from the States of Arizona, United States, or Sonora, Mexico. Arizona and Sonora have been part of the historical distribution of jaguars; however, poaching and habitat fragmentation have limited their distribution until they were declared extinct in the United States and endangered in Sonora. Therefore, a need was apparent to have this northernmost (Arizona/Sonora) jaguar population included in an overall jaguar molecular taxonomy and genetic diversity analyses. In this study, we used molecular genetic markers to examine diversity and taxonomy for jaguars in the Northwestern Jaguar Recovery Unit (NJRU; Sonora, Sinaloa, and Jalisco, Mexico; and southern Arizona and New Mexico, United States) relative to jaguars in other parts of the jaguar range (Central and South America). The objectives of this study were to:Collect opportunistic jaguar samples (hide, blood, hair, saliva, and scat), from historical and current individuals, that originated in NJRU areas of Arizona, New Mexico, and Sonora;Use these samples to assess molecular taxonomy of NJRU jaguars compared to data from a previous study of jaguars rangewide; andDevelop suggestions for conservation of NJRU jaguars based on the results.

  7. Southern New Mexico low temperature geothermal resource economic analysis

    SciTech Connect

    Fischer, C.L.; Whittier, J.; Witcher, J.C.; Schoenmackers, R.

    1990-08-01

    This report presents an overview of geothermal resource development for three-low temperature (i.e, <200{degree}F) sites in southern New Mexico: the Lower Animas Valley, the Las Cruces East Mesa, and Truth or Consequences. This report is intended to provide potential geothermal developers with detailed information on each site for planning and decision making purposes. Included in the overview for each site is both a full site characterization and an economic analysis of development costs associated with the construction and operation of both geothermal and fresh water systems at each of the three locations. The economic analysis focuses on providing utility services to a commercial greenhouse because greenhouse operations are among the most likely candidates for use of the resource base. 9 tabs., 8 figs.

  8. Fire Regimes and Forest Structure in the Mountains of Northwestern Mexico and Southern California

    NASA Astrophysics Data System (ADS)

    Stephens, S. L.

    2004-12-01

    In contrast to a few isolated forests in northern Mexico, most forests in the western Untied States have been significantly modified by fire suppression, harvesting, and livestock grazing. The culmination of these past management activities has produced over 20 million ha of US forests with high fire hazards and many of these areas are in need of restoration. Understanding reference conditions is challenging because we have few intact forests functioning under the continuing influence of climate variation, insects, diseases, and frequent fires. This presentation summarizes information from reference sites in northwestern Mexico and contrasts it to current forest structure and fire regimes in southern California forests. Heterogeneity is common in the intact forests of northwestern Mexico. Restoration targets across similar forests in the United States and elsewhere should incorporate variation and not manage for average characteristics at the stand level, replicated for all stands across very large spatial scales. Conservation of the forests in the northwester Mexico is critical because it is the last landscape-scale, old-growth mixed conifer forest in western North America with a relatively intact frequent fire regime.

  9. Lateral Variations of Lg Coda Q in Southern Mexico

    NASA Astrophysics Data System (ADS)

    Yamamoto, J.; Quintanar, L.; Herrmann, R. B.; Fuentes, C.

    Broad band digital three-component data recorded at UNM, a GEOSCOPE station, were used to estimate Lg coda Q for 34 medium size (3.9 <=mb<= 6.3) earthquakes with travel paths laying in different geological provinces of southern Mexico in an effort to establish the possible existence of geological structures acting as wave guides and/or travel paths of low attenuation between the Pacific coast and the Valley of Mexico. The stacked spectral ratio method proposed by XIE and NUTTLI (1988) was chosen for computing the coda Q. The variation range of Q0 (Q at 1Hz) and the frequency dependence parameter η estimates averaged on the frequency interval of 0.5 to 2Hz for the regions and the three components considered are: i) Guerrero region 173 <=Q0<= 182 and 0.6 <=Q0<= 0.7, ii) Oaxaca region 183 <=Q0<= 198 and 0.6 <=Q0<= 0.8, iii) Michoacan-Jalisco region 187 <=Q0<= 204 and 0.7 <=Q0<= 0.8 and iv) eastern portion of the Transmexican Volcanic Belt (TMVB) 313 <=Q0<= 335 and η = 0.9. The results show a very high coda Q for the TMVB as compared to other regions of southern Mexico. This unexpected result is difficult to reconcile with the geophysical characteristics of the TMVB, e.g., low seismicity, high volcanic activity and high heat flow typical of a highly attenuating (low Q) region. Visual inspection of seismograms indicates that for earthquakes with seismic waves traveling along the TMVB, the amplitude decay of Lg coda is anomalously slow as compared to other earthquakes in southern Mexico. Thus, it seems that the high Q value found does not entirely reflect the attenuation characteristics of the TMVB but it is probably contaminated by a wave-guide effect. This phenomenon produces an enhancement in the time duration of the Lg wave trains travelling along this geological structure. This result is important to establish the role played by the transmission medium in the extremely long duration of ground motion observed during the September 19, 1985 Michoacan earthquake. The

  10. Dryland agriculture in Mexico and the U.S. Southern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Following the "Dryland" monograph editors standardized chapter format, we describe the US southern Great Plains and northern Mexico dryland production regional boundaries and various climatic factors including: precipitation, evaporation, temperature, and water deficit. Dryland soil management, eros...

  11. Subduction erosion processes with application to southern Mexico

    NASA Astrophysics Data System (ADS)

    Keppie, Duncan Fraser

    Finite-element numerical models of ocean-continent subduction are used to investigate the roles of crustal frictional strength, subduction angle, and convergence rate in subduction erosion processes. These models exhibit two distinct modes of subduction erosion: (1) slow and steady, removing small blocks of material continually, and (2) fast and non-steady, removing a large forearc block in a single event. The slow mode, called edge-weakening subduction erosion, is enhanced by steeper subduction angles but acts to shallow the subduction angle at crustal depths. The fast mode, called internal-weakening subduction erosion, is enhanced by shallow subduction angles but acts to steepen the subduction angle at crustal depths. The two modes may alternate cyclically in nature and may account, in part, for the variation in subduction angle observed at the modern western American subduction zones. The slow, edge-weakening subduction erosion mode correlates well to subduction erosion processes widely reported for natural subduction zones. The fast, internal-weakening subduction erosion mode has previously been described only for subduction zones involving continental lithosphere on the lower plate. The removal of a 150--250 km wide forearc block from southern Mexico between 27--25 Ma and 21--19 Ma may be a first type example of internal-weakening subduction erosion at an ocean-continent subduction zone. The numerical models showing internal-weakening subduction erosion and the geological record of southern Mexico share the following geological features synchronous with forearc removal: (1) rapid trench migration rates approaching orthogonal plate convergence rates, (2) a step-wise shift in the locus of arc magmatism towards the upper plate, (3) forearc subsidence at the new margin of the upper plate, (4) a zone of crustal unroofing within the upper plate's new forearc region, and (5) a zone of subduction-antithetic thrust-sense shearing inboard of the crustal unroofing. These

  12. Influence of plant abundance on nectar feeding by Aedes aegypti (Diptera: Culicidae) in southern Mexico.

    PubMed

    Martinez-Ibarra, J A; Rodriguez, M H; Arredondo-Jimenez, J I; Yuval, B

    1997-11-01

    The availability of flowering plants affected the sugar feeding rates of female Aedes aegypti (L.) in 4 areas of a small city in southern Mexico. The proportion of mosquitoes containing sugar varied from 8 to 21% in 4 areas in direct relation to blooming plant abundance. Human density was similar in the 4 areas (range, 3.9-5.4 per house), whereas the number of flowering plants per house increased on the outskirts (range, 3.1-5.4 plants per house). Equal proportions of sugar positive females were nulliparous or parous, indicating similar sugar feeding at any age. In addition, nearly 60% of positive females were at the Christophers stage II, indicating a greater need for flight fuel during the early stages of egg development. We conclude that Ae. aegypti feeds frequently on nectar and that this activity is modulated by nectar availability. PMID:9439110

  13. Rise and Demise of a Southern Laramide Hinterland Plateau, US-Mexico Border Region

    NASA Astrophysics Data System (ADS)

    Lawton, T. F.; Clinkscales, C. A.; Jennings, G. R.

    2011-12-01

    -west normal faults are occupied by regionally widespread granitic and rhyolitic dikes ranging 34-27 Ma, yet the Oligocene volcaniclastic rocks are cut by the faults, indicating that the fault system was active during earliest-early late Oligocene magmatism. From the newly assembled data, we infer the presence of a high-standing plateau along the US-Mexico border that was backed by a magmatic arc in northern Mexico. The plateau was supported by lithosphere thickened during backarc contraction, which began in the interval 97-75 Ma. Although the depositional elevation of the Laramide lakes is not yet known, rivers flowed northward from the hinterland plateau toward the Uinta Basin as early as 80 Ma and corroborate the existence of a southern source area. The plateau was thus a long-lived feature with a longevity of as much as 40-50 m.y. It collapsed during Paleogene N-S extension triggered by some combination of thermal weakening by Oligocene magmatism, gravitational failure, and/or retrograde motion of the Farallon slab. The southern Laramide plateau was evidently linked both geographically and temporally to the Cordilleran hinterland plateau ("Nevadaplano") of Nevada and western Utah and thus constituted an important component of the greater Laramide orogen.

  14. Methods for estimating streamflow at mountain fronts in southern New Mexico

    USGS Publications Warehouse

    Waltemeyer, S.D.

    1994-01-01

    The infiltration of streamflow is potential recharge to alluvial-basin aquifers at or near mountain fronts in southern New Mexico. Data for 13 streamflow-gaging stations were used to determine a relation between mean annual stream- flow and basin and climatic conditions. Regression analysis was used to develop an equation that can be used to estimate mean annual streamflow on the basis of drainage areas and mean annual precipi- tation. The average standard error of estimate for this equation is 46 percent. Regression analysis also was used to develop an equation to estimate mean annual streamflow on the basis of active- channel width. Measurements of the width of active channels were determined for 6 of the 13 gaging stations. The average standard error of estimate for this relation is 29 percent. Stream- flow estimates made using a regression equation based on channel geometry are considered more reliable than estimates made from an equation based on regional relations of basin and climatic conditions. The sample size used to develop these relations was small, however, and the reported standard error of estimate may not represent that of the entire population. Active-channel-width measurements were made at 23 ungaged sites along the Rio Grande upstream from Elephant Butte Reservoir. Data for additional sites would be needed for a more comprehensive assessment of mean annual streamflow in southern New Mexico.

  15. Transition on the Geometry of the Cocos Plate in Central-Southern Mexico.

    NASA Astrophysics Data System (ADS)

    Rodríguez-Domínguez, M. Á.; Perez-Campos, X.; Valencia-Cabrera, D.; Clayton, R. W.; Cordoba-Montiel, F.; Valdes-Gonzales, C. M.; Brudzinski, M. R.; Cabral-Cano, E.; Arciniega-Ceballos, A.

    2014-12-01

    The tectonic setting, produced by the interaction between the Cocos and North American plates, follows complex geometries along the Pacific coast. Previous studies in central Mexico showed that the slab dips nearly horizontally before steeply subducting into the continental mantle; in contrast, in southern Mexico, the slabs dips under the continental plate at a constant angle. Receiver functions from four seismic networks: GECO (Geometry of Cocos), SSN (Servicio Sismológico Nacional), OxNet (Oaxaca Network) and UV (Universidad Veracruzana) are used to study the crustal structure underneath the stations, and image the subducting Cocos plate in order to define the geometry and the transition angle in central-southern Mexico.

  16. Petroleum hydrocarbons, fluorescent aromatic compounds in fish bile and organochlorine pesticides from areas surrounding the spill of the Kab121 well, in the Southern Gulf of Mexico: a case study.

    PubMed

    Gold-Bouchot, G; Ceja-Moreno, V; Chan-Cocom, E; Zapata-Perez, O

    2014-01-01

    In October 2007, a light crude oil spill took place in the off shore Kab121 oil well, 32 km north of the mouth of the Grijalva River, Tabasco, Mexico. In order to estimate the possible effects of oil spill on the biota in the area surrounding the spilled well, the level of different fractions of petroleum hydrocarbons were measured in fish, as well as the concentration of some chlorinated hydrocarbons and PCBs. The organisms examined were cat fish (Ariopsis felis), in addition fluorescent aromatic compounds in bile, the contaminants above mentioned and their relationship with cyotochrome P-450 and Ethoxyresorufin-O-deethylase, Glutathion-S-Transferase and catalase activities in liver were determined. The concentration of most pollutants were low, except PAHs. Spatial distribution of these compounds, as well as most biomarkers, reflected the highest exposure of fish to pollutants in the area adjacent to well, as well as in the proximity of rivers. The profile of exposure to this environment was chronic in nature and not temporary. PMID:24579530

  17. BUNK ROBINSON PEAK AND WHITMIRE CANYON ROADLESS AREAS, NEW MEXICO AND ARIZONA.

    USGS Publications Warehouse

    Hayes, Philip T.; Brown, S. Don

    1984-01-01

    The Bunk Robinson Peak and the Whitmire Canyon Roadless Areas straddle the Arizona-New Mexico State line in the southern Peloncillo Mountains. A mineral-resource survey identified a 1-sq-mi area of probable resource potential for molybdenum, bismuth, lead, zinc, and precious metals in the northwest part of the Bunk Robinson Peak roadless Area. This appraisal is based on the presence of hydrothermally altered rock and geochemical anomalies. Small deposits of perlite could be present locally, but none were seen. The possibility that resources of oil and (or) gas underlie the area is deemed to be very slight.

  18. Survey of heritable endosymbionts in southern Mexico populations of the fruit fly species Anastrepha striata and A. ludens.

    PubMed

    Martínez, Humberto; Toledo, Jorge; Liedo, Pablo; Mateos, Mariana

    2012-12-01

    Heritable endosymbiotic bacteria associated with insects are ubiquitous and taxonomically diverse. Many of these endosymbionts influence the fitness of their hosts and/or manipulate their host reproduction. Exploiting the effects of endosymbionts on hosts for pest control is a growing research area, but requires knowledge of endosymbionts associated with the target pest population. In this study, we used molecular methods to screen southern Mexico populations of two species of tephritid fruit fly pests, Anastrepha ludens and A. striata, for heritable bacteria. The only heritable endosymbiont found was Wolbachia in A. striata. Based on multilocus sequence typing and phylogenetic analyses, this Wolbachia strain is new and belongs to the Wolbachia supergroup B. Wolbachia strains previously reported in members of the genus Anastrepha in South America belong to supergroup A. We discuss the potential implications for pest control of the presence of a different Wolbachia strain in southern Mexico. PMID:22961037

  19. Trypanosoma cruzi Circulating in the Southern Region of the State of Mexico (Zumpahuacan) Are Pathogenic: A Dog Model

    PubMed Central

    Barbabosa-Pliego, Alberto; Díaz-Albiter, Hector M.; Ochoa-García, Laucel; Aparicio-Burgos, Esteban; López-Heydeck, Sandra M.; Velásquez-Ordoñez, Valente; Fajardo-Muñoz, Raul C.; Díaz-González, Sandra; De Oca-Jimenez, Roberto Montes; Barbosa-Mireles, Marco; Guzmán-Bracho, Carmen; Estrada-Franco, Jose G.; Garg, Nisha Jain; Vázquez-Chagoyán, Juan C.

    2009-01-01

    Here we describe clinical and pathologic evidence of Chagas disease caused in dogs by circulating Trypanosoma cruzi from a newly recognized endemic area in Mexico. We show that the Zumpahuacan isolate, although less virulent than the Sylvio-X10 reference strain that caused acute myocarditis and death, was pathogenic in dogs. Dogs infected with the Zumpahuacan isolate exhibited electrocardiographic alterations, left- and right-ventricle dilation, and hydropericardium. Histologically, diffused perimysial and endomysial lymphoplasmacytic cell infiltration, cardiomyocyte necrosis, and amastigote nests were noted in Zumpahuacan-infected dogs. These findings suggest that the risk of T. cruzi infection and Chagas disease is present in the State of Mexico, and further research is needed to identify the T. cruzi bio-types circulating in southern State of Mexico. PMID:19706902

  20. Correlation of upper Triassic strata between southern Colorado Plateau and southern High Plains, New Mexico

    SciTech Connect

    Lucas, S.G. )

    1989-09-01

    Almost 600 m of Upper Triassic strata are exposed in the Hagan basin. They pertain to the basal Agua Zarca member of the Chinle Formation (as much as 80 m), overlain by about 500 m of mud-rock-dominated red beds of the Petrified Forest Member of the Chinle Formation. The top of the Triassic section here is the 5.5-24 m-thick Correo Sandstone Bed of Chinle Formation, which is disconformably overlain by the medial silty member of the Middle Jurassic Entrada Sandstone. At Lamy, approximately 370 m of Upper Triassic strata represent the westernmost outcrops of the Triassic section typical of the Tucumcari basin. This Triassic section consists of about 140 m of Santa Rosa Formation (divisible into three members) overlain by a mud-rock-dominated section (Chinle Formation) split by a medial sandy interval, the Cuervo member (Trujillo Formation of the Palo Duro basin). The youngest Triassic strata near Lamy are rhythmically bedded sediments of the Redonda Member. Based on lithologic similarity, stratigraphic position, and limited paleontological data, the central New Mexico Upper Triassic strata support for the following correlations (from west to east): (1) Shinarump = Agua Zarca = Santa Rosa; (2) lower Petrified Forest = lower shale member of the Chinle = Tecovas; (3) Sonsela = Poleo = Cuervo = Trujillo; (4) upper Petrified Forest = upper shale member of the Chinle; and (5) Owl Rock = Redonda = Correo. These correlations reflect homotaxis of sedimentary cycles across a broad region of the southern Western Interior during the Late Triassic.

  1. Fore-arc Counterclockwise Rotation In Southern Mexico: Implications For The NA-CA-CO Triple Junction

    NASA Astrophysics Data System (ADS)

    Andreani, L.; Le Pichon, X.; Rangin, C.; Martinez-Reyes, J.

    2007-12-01

    Numerous studies, mainly based on structural and paleomagnetic data, consider the Southern Mexico as a crustal block (Southern Mexico Block, SMB) uncoupled from the North American plate with a southeast motion with respect to North America accommodated by extension through the central Trans-Mexican Volcanic Belt (TMVB). On the other hand, the accommodation of this motion on the southeastward boundary, especially at the Cocos/Caribbean/North American triple junction is still debated. The boundary between the SMB and the North American plate is constituted by three connected zones of deformation: (1) left-lateral transtension across the central TMVB, (2) left-lateral strike-slip faulting along the eastern TMVB and Veracruz area and (3) reverse and left- lateral strike-slip faulting in the Chiapas area. We show that these three active deformation zones accommodate a couterclockwise rotation of the SMB with respect to the North American plate. We specially discuss the Quaternary motion of the SMB with respect to the surrounding plates near the Cocos/Caribbean/North American triple junction. The model we propose predicts a Quaternary couterclockwise rotation of 0.45 deg/Ma with a pole located at 24.2N and 91.8W. Finally we discuss the geodynamic implications of this counterclockwise rotation. The Southern Mexico Block motion is generally assumed to be the result of slip partitioning at the trench. However the obliquity of the subduction is too small to explain slip partitioning. The motion could be facilitated by the high thermal gradient and gravitational collapse that affects central Mexico or by partial coupling with the eastward motion of the Caribbean plate.

  2. 7 CFR 319.8-11 - From approved areas of Mexico.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false From approved areas of Mexico. 319.8-11 Section 319.8... Conditions for the Entry of Cotton and Covers from Mexico § 319.8-11 From approved areas of Mexico. (a) Entry... in, and which were produced and handled only in approved areas of Mexico 5 may be authorized...

  3. 7 CFR 319.8-11 - From approved areas of Mexico.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false From approved areas of Mexico. 319.8-11 Section 319.8... Conditions for the Entry of Cotton and Covers from Mexico § 319.8-11 From approved areas of Mexico. (a) Entry... in, and which were produced and handled only in approved areas of Mexico 5 may be authorized...

  4. 7 CFR 319.8-11 - From approved areas of Mexico.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false From approved areas of Mexico. 319.8-11 Section 319.8... Conditions for the Entry of Cotton and Covers from Mexico § 319.8-11 From approved areas of Mexico. (a) Entry... in, and which were produced and handled only in approved areas of Mexico 4 may be authorized...

  5. 7 CFR 319.8-11 - From approved areas of Mexico.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false From approved areas of Mexico. 319.8-11 Section 319.8... Conditions for the Entry of Cotton and Covers from Mexico § 319.8-11 From approved areas of Mexico. (a) Entry... in, and which were produced and handled only in approved areas of Mexico 5 may be authorized...

  6. 7 CFR 319.8-11 - From approved areas of Mexico.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false From approved areas of Mexico. 319.8-11 Section 319.8... Conditions for the Entry of Cotton and Covers from Mexico § 319.8-11 From approved areas of Mexico. (a) Entry... in, and which were produced and handled only in approved areas of Mexico 5 may be authorized...

  7. Habitat features and predictive habitat modeling for the Colorado chipmunk in southern New Mexico

    USGS Publications Warehouse

    Rivieccio, M.; Thompson, B.C.; Gould, W.R.; Boykin, K.G.

    2003-01-01

    Two subspecies of Colorado chipmunk (state threatened and federal species of concern) occur in southern New Mexico: Tamias quadrivittatus australis in the Organ Mountains and T. q. oscuraensis in the Oscura Mountains. We developed a GIS model of potentially suitable habitat based on vegetation and elevation features, evaluated site classifications of the GIS model, and determined vegetation and terrain features associated with chipmunk occurrence. We compared GIS model classifications with actual vegetation and elevation features measured at 37 sites. At 60 sites we measured 18 habitat variables regarding slope, aspect, tree species, shrub species, and ground cover. We used logistic regression to analyze habitat variables associated with chipmunk presence/absence. All (100%) 37 sample sites (28 predicted suitable, 9 predicted unsuitable) were classified correctly by the GIS model regarding elevation and vegetation. For 28 sites predicted suitable by the GIS model, 18 sites (64%) appeared visually suitable based on habitat variables selected from logistic regression analyses, of which 10 sites (36%) were specifically predicted as suitable habitat via logistic regression. We detected chipmunks at 70% of sites deemed suitable via the logistic regression models. Shrub cover, tree density, plant proximity, presence of logs, and presence of rock outcrop were retained in the logistic model for the Oscura Mountains; litter, shrub cover, and grass cover were retained in the logistic model for the Organ Mountains. Evaluation of predictive models illustrates the need for multi-stage analyses to best judge performance. Microhabitat analyses indicate prospective needs for different management strategies between the subspecies. Sensitivities of each population of the Colorado chipmunk to natural and prescribed fire suggest that partial burnings of areas inhabited by Colorado chipmunks in southern New Mexico may be beneficial. These partial burnings may later help avoid a fire

  8. Examining the Obstacles and Possible Solutions for Improving Science Education in Southern Mexico

    ERIC Educational Resources Information Center

    Cisneros-Cohernour, Edith Juliana; Avila, Maria Teresa Lopez; Lara, Mario Baas

    2005-01-01

    The purpose of this qualitative study was to obtain a better understanding of the obstacles and possible solutions for improving science education in Southern Mexico. It provides information about the challenges faced by teachers and school administrators, and possible alternatives for improving the quality of teaching after ten years of a…

  9. 47 CFR 22.950 - Provision of service in the Gulf of Mexico Service Area (GMSA)

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Provision of service in the Gulf of Mexico... service in the Gulf of Mexico Service Area (GMSA) The GMSA has been divided into two areas for licensing purposes, the Gulf of Mexico Exclusive Zone (GMEZ) and the Gulf of Mexico Coastal Zone (GMCZ). This...

  10. 47 CFR 22.950 - Provision of service in the Gulf of Mexico Service Area (GMSA)

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Provision of service in the Gulf of Mexico... service in the Gulf of Mexico Service Area (GMSA) The GMSA has been divided into two areas for licensing purposes, the Gulf of Mexico Exclusive Zone (GMEZ) and the Gulf of Mexico Coastal Zone (GMCZ). This......

  11. 47 CFR 22.950 - Provision of service in the Gulf of Mexico Service Area (GMSA)

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Provision of service in the Gulf of Mexico... service in the Gulf of Mexico Service Area (GMSA) The GMSA has been divided into two areas for licensing purposes, the Gulf of Mexico Exclusive Zone (GMEZ) and the Gulf of Mexico Coastal Zone (GMCZ). This......

  12. 47 CFR 22.950 - Provision of service in the Gulf of Mexico Service Area (GMSA)

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Provision of service in the Gulf of Mexico... service in the Gulf of Mexico Service Area (GMSA) The GMSA has been divided into two areas for licensing purposes, the Gulf of Mexico Exclusive Zone (GMEZ) and the Gulf of Mexico Coastal Zone (GMCZ). This......

  13. 47 CFR 22.950 - Provision of service in the Gulf of Mexico Service Area (GMSA)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Provision of service in the Gulf of Mexico... service in the Gulf of Mexico Service Area (GMSA) The GMSA has been divided into two areas for licensing purposes, the Gulf of Mexico Exclusive Zone (GMEZ) and the Gulf of Mexico Coastal Zone (GMCZ). This...

  14. LITTLE DOG AND PUP CANYONS ROADLESS AREA, NEW MEXICO.

    USGS Publications Warehouse

    Hayes, Philip T.; Bigsby, Philip R.

    1984-01-01

    The Little Dog and Pup Canyons Roadless Area comprises about 41 sq mi along the precipitous west escarpment of the Guadalupe Mountains in southeastern New Mexico. On the basis of a mineral survey area is considered to have a portable potential for oil and (or) gas resources and little likelihood for the occurrence of other mineral or energy resources. Only the drilling of exploratory holes in or near the roadless area could conclusively determine its resource potential for oil and (or) gas.

  15. Mexico Fires

    Atmospheric Science Data Center

    2013-04-18

    article title:  Smoke from Fires in Southern Mexico     View Larger Image ... southern Mexico sent smoke drifting northward over the Gulf of Mexico. These views from the Multi-angle Imaging SpectroRadiometer (MISR) ...

  16. Landscape surrounding human settlements and Anopheles albimanus (Diptera: Culicidae) abundance in Southern Chiapas, Mexico.

    PubMed

    Rodriguez, A D; Rodriguez, M H; Hernandez, J E; Dister, S W; Beck, L R; Rejmankova, E; Roberts, D R

    1996-01-01

    Landscape characteristics that may influence important components of the Anopheles albimanus Wiedemann life cycle, including potential breeding sites, suitable diurnal resting sites, and possible sources of blood meals, were analyzed at 14 villages in a malarious area of southern Mexico. An. albimanus adults were collected weekly in each village using UV-light traps between July 1991 and August 1992. Based on rainfall, the study was divided into 6 seasonal periods. Villages were considered to have high mosquito abundance when >5 mosquitoes per trap per night were collected during any 1 of the 6 seasonal periods. The extension and frequency of 11 land cover types surrounding villages were determined using aerial photographs and subsequently verified through field surveys. Elevation was the main landscape feature that separated villages with low and high mosquito abundance. All villages with high mosquito abundance were below 25 m. Transitional and mangrove land cover types were found only in the high mosquito abundance group. Flooded areas as potential breeding sites and potential adult resting sites in unmanaged pastures were significantly more frequent in areas surrounding villages with high mosquito abundance. No significant differences in density of cattle and horses were found among village groups. Overall, surrounding breeding sites located at low elevations in flooded unmanaged pastures seemed to be the most important determinants of An. albimanus adult abundance in the villages. PMID:8906903

  17. Biological characteristics of geographically isolated populations of Meccus mazzottii (Hemiptera: Reduviidae) in southern Mexico.

    PubMed

    Martínez-Ibarra, J A; Nogueda-Torres, B; Vargas-Llamas, V; García-Benavides, G; Bustos-Saldaña, R; Villagrán, M E; de Diego-Cabrera, J A; Tapia-González, J M

    2014-01-01

    Chagas disease, caused by Trypanosoma cruzi Chagas, is one of the most epidemiologically important vector-borne zoonoses in Mexico. Among the 32 reported triatomine species from Mexico, Meccus mazzottii (Usinger) (Hemiptera: Reduviidae) is one of the most important vectors of T. cruzi in the southern part of the country. Variability among populations of triatomines has been recorded for several species (Meccus longipennis (Usinger) and Meccus pallidipennis (Stal)) that are closely related to M. mazzottii, showing an apparent influence of local environmental conditions on the biology of each population, which could modify the impact of vector control measurements. Therefore, this study sought to compare the biological features of populations of M. mazzottii from two geographically far apart areas that have similar environmental characteristics and to compare populations from close geographical areas that have different environmental characteristics. The mean longevity, percentages of mortality of nymphs, the total mean number of bloodmeals to molt (considered instar by instar), the mean number of eggs laid by females, and the percentage of hatched eggs were similar between the two localities that are geographically far apart but have similar environmental characteristics. On the other hand, important differences were noticed when a comparison was carried out on the two localities with similar environmental conditions with respect to that locality with different conditions, independent of geographic distance. Most of the studied parameters led us to conclude that the three studied populations are very highly influenced by local environmental conditions. The results of this study indicate the importance of studying the biological characteristics of local populations of triatomines to carry out specific control measurements, instead of using standard ones that could fail if they are not adapted to the target population. PMID:25502028

  18. Ordovician and Late Paleozoic Early Mesozoic tectonothermal history of the La Noria area, northern Acatlán Complex, southern Mexico: Record of convergence in the Rheic and paleo-Pacific Oceans

    NASA Astrophysics Data System (ADS)

    Hinojosa-Prieto, H. R.; Nance, R. D.; Keppie, J. D.; Dostal, J. V.; Ortega-Rivera, A.; Lee, J. K. W.

    2008-12-01

    The La Noria area lies in the northern part of the polydeformed Acatlán Complex, (southern Mexican Mixteca terrane), and the rocks record the following sequence of events: (i) Early-Middle Ordovician deposition of the volcaniclastic El Epazote and Las Calaveras units; (ii) late Middle Ordovician intrusion of the 467 ± 16 Ma megacrystic, peraluminous, rift-related granitoids; (iii) late Devonian, D 1, greenschist facies deformation; (iv) intrusion of the Los Malpasos leucogranite and associated minor intrusions; (v) Middle Mississippian, D 2, dextral N-S deformation also under greenschist facies metamorphic conditions; and (vi) undated D 3 kink band development. U-Pb LA-ICPMS detrital zircon ages: (a) the El Epazote unit yielded: a mean 206Pb/ 238U age from the youngest five concordant 206Pb/ 238Pb age of 488 ± 10 Ma, with other age peaks at ca. 506, ca. 1077, and ca. 1779 Ma and a few concordant Neoproterozoic ages: and (b) the Las Calaveras unit yielded a mean 206Pb/ 238U age from the sixteen youngest detrital zircons of 466 ± 10 Ma with other population age peaks ca. 1111, and ca. 1753 Ma. These data imply that granitoid intrusion was roughly synchronous with deposition of some of the host rocks. Whereas sources for most of the detrital zircons may be found in either the Acatlán and Oaxacan complexes, Laurentia or Gondwana, a Neoproterozoic source is most likely in Amazonia. The rocks record three low-grade deformational episodes: (i) D 1 produced a weak compositional banding and/or schistosity (S 1) under greenschist facies conditions; (ii) D 2, also occurred under greenschist facies conditions, and developed tight to isoclinal folds (F 2) in S 1 and an axial planar spaced-cleavage (S 2) that is co-planar with S 1; and (iii) D 3 produced reverse and conjugate kink bands (F 3) that deform the S 1/S 2 composite foliation. The leucogranite and related dikes that intrude the complex record only the latter two deformational events. Ca. 330 Ma 40Ar/ 39Ar

  19. CHAMA RIVER CANYON WILDERNESS AND CONTIGUOUS ROADLESS AREA, NEW MEXICO.

    USGS Publications Warehouse

    Ridgley, Jennie L.; Light, Thomas D.

    1984-01-01

    Results of mineral surveys indicate that the Chama River Canyon Wilderness and contiguous roadless area in new Mexico have a probable mineral-resource potential for copper with associated uranium and silver. Gypsum occurs throughout the area, exposed in the canyon walls. Further study of the wilderness should concentrate on exploratory drilling to test the oil and gas potential of Pennsylvanian strata and evaluate vanadium anomalies in the Todilto as a prospecting guide for locating uranium.

  20. Irrigation water quality in southern Mexico City based on bacterial and heavy metal analyses

    NASA Astrophysics Data System (ADS)

    Solís, C.; Sandoval, J.; Pérez-Vega, H.; Mazari-Hiriart, M.

    2006-08-01

    Xochimilco is located in southern Mexico City and represents the reminiscence of the pre-Columbian farming system, the "chinampa" agriculture. "Chinampas" are island plots surrounded by a canal network. At present the area is densely urbanized and populated, with various contaminant sources contributing to the water quality degradation. The canal system is recharged by a combination of treated-untreated wastewater, and precipitation during the rainy season. Over 40 agricultural species, including vegetables, cereals and flowers, are produced in the "chinampas". In order to characterize the quality of Xochimilcos' water used for irrigation, spatial and temporal contaminant indicators such as microorganisms and heavy metals were investigated. Bacterial indicators (fecal coliforms, fecal enterococcus) were analyzed by standard analytical procedures, and heavy metals (such as Fe, Cu, Zn and Pb) were analyzed by particle induced X-ray emission (PIXE). The more contaminated sites coincide with the heavily populated areas. Seasonal variation of contaminants was observed, with the higher bacterial counts and heavy metal concentrations reported during the rainy season.

  1. Environmental forcing of the Campeche cold-water coral province, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Hebbeln, D.; Wienberg, C.; Wintersteller, P.; Freiwald, A.; Becker, M.; Beuck, L.; Dullo, C.; Eberli, G. P.; Glogowski, S.; Matos, L.; Forster, N.; Reyes-Bonilla, H.; Taviani, M.; MSM 20-4 shipboard scientific party, the

    2013-11-01

    With an extension of >40 km2 the recently discovered Campeche cold-water coral province located at the northeastern rim of the Campeche Bank in the southern Gulf of Mexico belongs to the largest coherent cold-water coral areas discovered so far. The Campeche province consists of numerous 20 to 40 m high coral ridges that are developed in intermediate water depths of 500 to 600 m. The ridges are colonized by a vivid cold-water coral ecosystem that covers the upper flanks and summits. The rich coral community is dominated by the framework-building scleractinia Enallopsammia profunda and Lophelia pertusa while the associated benthic megafauna shows a rather scarce occurrence. The recent environmental setting is characterized by a high surface water production caused by a local upwelling center and a dynamic bottom water regime comprising vigorous bottom currents, internal waves and strong density contrasts, which all together provide optimal conditions for the growth of cold-water corals. The strong hydrodynamics - potentially supported by the diel vertical migration of zooplankton in the Campeche area - drive the delivering of food particles to the corals. The Campeche cold-water coral province is, thus, an excellent example highlighting the importance of the hydrographic setting in securing the food supply for the development of large and vivid cold-water coral ecosystems.

  2. Environmental forcing of the Campeche cold-water coral province, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Hebbeln, D.; Wienberg, C.; Wintersteller, P.; Freiwald, A.; Becker, M.; Beuck, L.; Dullo, C.; Eberli, G. P.; Glogowski, S.; Matos, L.; Forster, N.; Reyes-Bonilla, H.; Taviani, M.

    2014-04-01

    With an extension of > 40 km2 the recently discovered Campeche cold-water coral province located at the northeastern rim of the Campeche Bank in the southern Gulf of Mexico belongs to the largest coherent cold-water coral areas discovered so far. The Campeche province consists of numerous 20-40 m-high elongated coral mounds that are developed in intermediate water depths of 500 to 600 m. The mounds are colonized by a vivid cold-water coral ecosystem that covers the upper flanks and summits. The rich coral community is dominated by the framework-building Scleractinia Enallopsammia profunda and Lophelia pertusa, while the associated benthic megafauna shows a rather scarce occurrence. The recent environmental setting is characterized by a high surface water production caused by a local upwelling center and a dynamic bottom-water regime comprising vigorous bottom currents, obvious temporal variability, and strong density contrasts, which all together provide optimal conditions for the growth of cold-water corals. This setting - potentially supported by the diel vertical migration of zooplankton in the Campeche area - controls the delivering of food particles to the corals. The Campeche cold-water coral province is, thus, an excellent example highlighting the importance of the oceanographic setting in securing the food supply for the development of large and vivid cold-water coral ecosystems.

  3. Richness, infestation and specificity of spinturnicid mites (Acari: Spinturnicidae) on bats in southern Oaxaca, Mexico.

    PubMed

    Colín-Martínez, Helisama; García-Estrada, Carlos

    2016-10-01

    Studies of mites on bats in the Mexican state Oaxaca are scarce. Our objective was therefore to evaluate the richness, infestation, and specificity of spinturnicid mites on bats in southern Oaxaca, Mexico. Bats were monthly captured from April 2010 to February 2011, in four sites using four mist-nets; also, we visited natural (crevices) and artificial roosts (tunnel). Of each bat we account the number of spinturnicid mites, considering the area of the body where they were collected. Mites were preserved in 70 % ethanol and later they were mounted on microscope slides in Hoyer's medium. We captured bats of 15 species, of which eight species were infested. We recorded seven spinturnicid mites: five of the genus Periglischrus, one of the genus Cameronieta, and one of the genus Mesoperiglischrus. Periglischrus caligus, P. iheringi, and Periglischrus sp. are new records on Artibeus lituratus, Glossophaga soricina, and G. commissarisi, respectively. More infested bat species were Artibeus jamaicensis (93.8 %), A. lituratus (88.9 %), G. commissarisi and Sturnira parvidens (both 66.7 %). Prevalence of A. jamaicensis and A. lituratus was significantly higher than most other bat species. Although prevalence percentage was high, mean and median intensity were low. Spinturnicid mites were recorded in particular areas of a bat's body; therefore, they could be an additional tool for the taxonomic identification of bats. PMID:27431824

  4. Biological variation in two Anopheles vestitipennis populations with different feeding preferences in southern Mexico.

    PubMed

    Ulloa, Armando; Rodríguez, Mario H; Arredondo-Jimenez, Juan I; Fernandez-Salas, Ildefonso

    2005-12-01

    The lengths of gonotrophic cycle and egg development and survival rate were studied in Anopheles vestitipennis collected in horse and human-baited traps in southern Mexico. The gonotrophic cycle duration was estimated using cross-correlation analysis, whereas the survival rate was assessed using a vertical method. Daily changes of parity rates gave significant correlation indices at 3 and 4 days in the zoophilic and anthropophilic populations, respectively. The minimum time required to develop mature eggs after blood feeding was 54 and 60 h, and the survival rate was 0.93 and 0.88 in zoophilic and anthropophilic female mosquito populations, respectively. These biological differences provide additional support for the existence of subpopulations with distinctive feeding preferences within An. vestitipennis in southern Mexico. PMID:16506558

  5. Paleomagnetic study of the Cretaceous Morelos Formation, Guerrero State, southern Mexico

    NASA Astrophysics Data System (ADS)

    Urrutia-fucugauchi, J.

    1988-03-01

    Paleomagnetic results are reported for a ~ 30 m thick limestone section of the Albian-Cenomanian Morelos Formation, Guerrero State, in southern Mexico (-17.75 °N, 99.50° W). Seventy-two specimens from 35 samples were subjected to detailed alternating field (AF) or thermal demagnetizations. Most specimens were stable and presented a single magnetization component remaining after removal of low-coercivity, low-blocking temperature components. End-point and vector analyses give a mean direction and pole position after structural correction (dip ~ 14°) of D = 332.7°, I = 46.8°, k = 215, α95 = 4° and 63° N, 198° E ( dp = 3, dm = 5), respectively. The pole position agrees with mid-Cretaceous poles reported for cratonic North America, suggesting that the area was already keeping a similar latitudinal position relative to the North American craton by mid-Cretaceous time. Most samples present normal polarity, as expected within the Cretaceous normal interval, but four samples from a single bed present intermediate and reverse polarity, suggesting the occurrence of a reverse event during the late Albian-earliest Cenomanian.

  6. Risk factors for Plasmodium vivax infection in the Lacandon forest, southern Mexico.

    PubMed

    Danis-Lozano, R; Rodriguez, M H; Gonzalez-Ceron, L; Hernandez-Avila, M

    1999-06-01

    A study was conducted to characterize the risk of Plasmodium vivax infection in the Lacandon forest, southern Mexico. Blood samples and questionnaire data were collected in 1992. Malaria cases (n = 137) were identified by the presence of symptoms and a positive thick blood smear. The control group included individuals with negative antibody titres and no history of malaria (n = 4994). From 7628 individuals studied, 1006 had anti-P. vivax antibodies. Seroprevalence increased with age. Risk factors associated with infection included: place of birth outside the village of residence (odds ratio, OR 11.67; 95% CI 5.21-26.11); no use of medical services (OR 4.69, 95% CI 3.01-7.29), never using bed-nets (OR 3.98, 95 % CI 1.23-12.86) and poor knowledge of malaria transmission, prevention and treatment (OR 2.30, 95 % CI 1.30-4.07). Health education represents the best recommendation for controlling the disease in the area. PMID:10459651

  7. Risk factors for Plasmodium vivax infection in the Lacandon forest, southern Mexico.

    PubMed Central

    Danis-Lozano, R.; Rodriguez, M. H.; Gonzalez-Ceron, L.; Hernandez-Avila, M.

    1999-01-01

    A study was conducted to characterize the risk of Plasmodium vivax infection in the Lacandon forest, southern Mexico. Blood samples and questionnaire data were collected in 1992. Malaria cases (n = 137) were identified by the presence of symptoms and a positive thick blood smear. The control group included individuals with negative antibody titres and no history of malaria (n = 4994). From 7628 individuals studied, 1006 had anti-P. vivax antibodies. Seroprevalence increased with age. Risk factors associated with infection included: place of birth outside the village of residence (odds ratio, OR 11.67; 95% CI 5.21-26.11); no use of medical services (OR 4.69, 95% CI 3.01-7.29), never using bed-nets (OR 3.98, 95 % CI 1.23-12.86) and poor knowledge of malaria transmission, prevention and treatment (OR 2.30, 95 % CI 1.30-4.07). Health education represents the best recommendation for controlling the disease in the area. PMID:10459651

  8. First record of Bison antiquus from the Late Pleistocene of southern Mexico

    NASA Astrophysics Data System (ADS)

    Jiménez-Hidalgo, Eduardo; Cabrera-Pérez, Lucía; MacFadden, Bruce J.; Guerrero-Arenas, Rosalía

    2013-03-01

    In Mexico, just 54% of the reported Pleistocene Bison material has been identified to species. Current paleontological research in northwestern Oaxaca, southern Mexico, has allowed collection of several specimens of Bison antiquus that are part of the Viko Vijin Local Fauna. B. antiquus had a very wide geographic distribution, from lowlands to mountainous landscapes of North and Central America. The B. antiquus record from southern Mexico links their former records from central Mexico and middle Central America and confirms this wide geographic distribution. The univariate mesowear score of the B. antiquus specimens from Oaxaca is in the lower extreme of grazers and the upper end of mixed-feeders, suggesting that they had a less abrasive diet than the modern plains Bison, as has been observed in other samples of this species from diverse parts of North America. The presence of B. antiquus in the Viko Vijin L. F. constrains the age of this fossil assemblage within a range from 60 Ka to 11.7 Ka.

  9. The ecology of trachoma: an epidemiological study in southern Mexico

    PubMed Central

    Taylor, Hugh R.; Velasco, Francisco M.; Sommer, Alfred

    1985-01-01

    A total of 1097 people in two communities in Chiapas, Mexico, were examined for trachoma, and information was obtained about personal and family hygiene. Trachoma was hyperendemic; approximately 25% of those under 10 years old were found to have significant inflammatory trachoma and almost 100% of those aged over 40 years had cicatricial trachoma, although the prevalence of trachoma differed significantly between the two communities. Risk factor analysis was performed by contingency table analysis and χ2 testing. The most important parameter associated with the occurrence and severity of inflammatory trachoma in children was the frequency of face washing. Children who washed their faces 7 or more times per week had significantly less trachoma than those who washed less often (χ22df = 28.7; P < 0.001). This effect was independent of age, use of clean water and soap, or use of clothes to dry the face. Children who washed infrequently and who used clothes to dry the face or clean the nose were more at risk for trachoma. No parameters of family hygiene or socioeconomic status correlated with the amount of trachoma in a family. These data confirm and quantify for the first time the long-held belief that trachoma is associated with poor personal hygiene and suggest potentially effective and efficient intervention strategies. PMID:3876172

  10. Occurrence of glyphosate in water bodies derived from intensive agriculture in a tropical region of southern Mexico.

    PubMed

    Ruiz-Toledo, Jovani; Castro, Ricardo; Rivero-Pérez, Norma; Bello-Mendoza, Ricardo; Sánchez, Daniel

    2014-09-01

    Glyphosate is an agrochemical widely used to control weeds. However, glyphosate spreads to water bodies by spray-drift, run-off and leaching, potentially causing detrimental effects on non-target biota. There is no information on the occurrence of this herbicide in water bodies near crop fields in Mexico, although it is the most commonly used pesticide in this country. To fill this gap, we quantified glyphosate in water bodies from twenty-three locations, including natural protected areas and agricultural areas in southern Mexico, during the dry and the rainy seasons. We expected (1) higher concentrations during the dry season due to reduced dilution by precipitation and, (2) absence of glyphosate in the protected areas. In agreement with our expectation, concentration of glyphosate was higher during the dry season (up to 36.7 μg/L). Nonetheless, glyphosate was detected in all samples-including natural protected areas. These results emphasize the need for an evaluation of the impact of glyphosate on native species as well as regulate its use. PMID:25011503

  11. Valley fill in the Roswell-Artesia area, New Mexico

    USGS Publications Warehouse

    Lyford, Forest P.

    1973-01-01

    Drill samples from 225 water and oil wells in an area 70 miles long and 20 miles wide in the Roswell-Artesia area, southeastern New Mexico were examined. A thickness map and a saturated thickness map of the valley-fill sediments were constructed. Maximum depth of valley fill is about 300 feet in large closed depressions near Roswell, Hagerman, and Artesia. The depressions were formed by the solution of carbonates and evaporites that underlie the fill. Maximum saturated thickness is about 250 feet in depressions near Hagerman and Artesia and about 300 feet in a depression near Roswell.

  12. Late Quaternary paleosols and climate change in southern New Mexico

    SciTech Connect

    Monger, H.C. . Agronomy Dept.); Cole, D.R. ); Gish, J.W. )

    1992-01-01

    A climate change toward more arid conditions in the southwest US has been postulated for a period around 7 ka. In southern NM, deposition of the youngest generation of alluvial fans surrounding arid mountains began around 7 ka based on radiocarbon dates of charcoal. The deposition of these fans has been interpreted as evidence for aridity because plant cover would have declined, thus making the landscape more susceptible to erosion and sedimentation. Isotopes of pedogenic calcite and pollen content in well-preserved paleosols associated with alluvial fans provide additional evidence for testing the aridity hypothesis. Buried paleosols, ranging from 23,070 [+-] 190 to 9,070 [+-] 70 yr BP, contain pedogenic calcite that is isotopically heavier in carbon than calcite in soils younger than 7 ka. The buried paleosols have a mean delta C-13 values of [minus]2.2 [+-] 0.8 [per thousand] (PDP). In contrast, soils younger than 7 ka have a man delta C-13 value of [minus]7.8 [+-] 1.3 [per thousand]. The higher delta C-13 values in buried paleosols may reflect the presence of abundant C[sub 4] grasses, similar to the present vegetation in the southern High Plains, which would have curtailed erosion. Pollen analysis reveals that buried paleosols contain more grass pollen than soils younger than 7 ka, which contain high proportions of desertscrub pollen taxa. delta O-18 values of pedogenic calcite are similar for the buried paleosols ([minus]5.2 [+-] 0.3 [per thousand] PDB) and soils younger than 7 ka ([minus]5.1 [+-] 0.6 [per thousand]). These values indicate a relatively constant mean annual temperature of approximately 14C, which prevailed throughout late Pleistocene and Holocene time.

  13. HELLS HOLE ROADLESS AREA, ARIZONA AND NEW MEXICO.

    USGS Publications Warehouse

    Ratte, James C.; Briggs, John P.

    1984-01-01

    The Hells Hole Roadless Area encompasses about 50 sq mi along the Arizona-New Mexico State line. The area was studied and the southeastern part was determined to have a probable mineral-resource potential for the discovery of base- or precious-metal deposits related to igneous intrusions of middle to late Tertiary age. There also is a probable resource potential for porphyry copper mineralization of Laramide age beneath the Tertiary volcanic rocks that cover the area. There is little promise for the occurrence of energy resources in the area. Additional geochemical and petrological studies of the rocks of the Hells Hole volcanic center and modeling of geophysical anomalies are necessary to adequately appraise the mineral-resource potential of the area.

  14. Large-scale environmental influences on the benthic macroinfauna of the southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Hernández-Arana, Hector A.; Rowden, Ashley A.; Attrill, Martin J.; Warwick, Richard M.; Gold-Bouchot, Gerardo

    2003-12-01

    The influence of large-scale natural disturbance from winter storms ('northers') and river runoff on the macrobenthic community structure of the southern Gulf of Mexico was investigated in both carbonate and transitional carbonate-terrigenous sedimentary environments. Samples of the infauna were obtained in three seasons from 13 stations from two 250 km transects along 80-170 and 20-50 m water depth. Samples after the northers season had the lowest total number of families and individuals, 114 and 2940, respectively, compared to the dry and rainy seasons with 129 and 132 families and 11580 and 15266 individuals, respectively. Spatial patterns of macroinfauna composition varied across and along the shelf as a response to sedimentary environments and depth. Coarser sediments from the carbonate area harboured the highest mean densities per station with 500-24,000 individuals m -2 and 108-122 families in total, compared to the transitional sediment with 500-8200 individuals m -2 and 56-74 families across the three seasons. Univariate and multivariate statistical techniques demonstrated that low densities and number of taxa were associated with winter storms, but storm influence was dependent on depth and sediment type. Multiple linear regression analysis and BIOENV analysis indicated that sediment mean grain size, percentage of clay and organic matter best explained the macroinfauna spatial patterns, although BIOENV indicated that depth has an overriding role. An increase in densities of opportunistic taxa (numerous polychaetes of small sizes) was observed four months after the 'northers' and this was more evident in the area of carbonate sediment. Additionally a combined disturbance from northers and river runoff is suspected to be responsible for a naturally impoverished macroinfauna community in the transitional sedimentary environment.

  15. 33 CFR 334.763 - Naval Support Activity Panama City; Gulf of Mexico; restricted area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... City; Gulf of Mexico; restricted area. 334.763 Section 334.763 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.763 Naval Support Activity Panama City; Gulf of Mexico; restricted area. (a) The area. The area...

  16. 33 CFR 334.763 - Naval Support Activity Panama City; Gulf of Mexico; restricted area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... City; Gulf of Mexico; restricted area. 334.763 Section 334.763 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.763 Naval Support Activity Panama City; Gulf of Mexico; restricted area. (a) The area. The area...

  17. 33 CFR 334.763 - Naval Support Activity Panama City; Gulf of Mexico; restricted area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... City; Gulf of Mexico; restricted area. 334.763 Section 334.763 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.763 Naval Support Activity Panama City; Gulf of Mexico; restricted area. (a) The area. The area...

  18. Seismicity and Stress in the Southern Jalisco Block, Mexico.

    NASA Astrophysics Data System (ADS)

    Sánchez, J. J.; Núñez-Cornũ, F. J.

    2008-12-01

    Fault plane solutions for a group of 41 earthquakes with Mw magnitudes between 4.9 and 8.0, detected between November 1980 and May 2007, were extracted from the CMT catalog and used to investigate possible spatial and temporal variations of stress in the south part of the Jalisco Block. Using rigorous statistical tests we decide on the quality and variability of the earthquake source mechanisms and with the use of FMSI and LSIB stress tensor inversion techniques and cumulative misfit analysis find, at the 95% confidence level or more, significantly different regions and periods of stress regime. An important difference in seismicity and stress between the southern and northern regions of the Jalisco Block is highlighted by the regular occurrence of earthquakes to the south, in stark contrast with the scarcity of seismicity with Mw > 4.9 north of 19.36°N, a region that is illuminated with smaller earthquakes when local temporal or permanent deployments of seismographs are used, as noted by previous studies. We conclude that the region located near the coordinates 105°W and 18.43°N appears as a particularly diffuse zone affected by various stress styles and that the period following the great Mw 8.0 earthquake on October 9, 1995 appears as a short-lived change in stress induced by the great shock.

  19. Massive asphalt deposits, oil seepage, and gas venting support abundant chemosynthetic communities at the Campeche Knolls, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Sahling, Heiko; Borowski, Christian; Escobar-Briones, Elva; Gaytán-Caballero, Adriana; Hsu, Chieh-Wei; Loher, Markus; MacDonald, Ian; Marcon, Yann; Pape, Thomas; Römer, Miriam; Rubin-Blum, Maxim; Schubotz, Florence; Smrzka, Daniel; Wegener, Gunter; Bohrmann, Gerhard

    2016-08-01

    Hydrocarbon seepage is a widespread process at the continental margins of the Gulf of Mexico. We used a multidisciplinary approach, including multibeam mapping and visual seafloor observations with different underwater vehicles to study the extent and character of complex hydrocarbon seepage in the Bay of Campeche, southern Gulf of Mexico. Our observations showed that seafloor asphalt deposits previously only known from the Chapopote Knoll also occur at numerous other knolls and ridges in water depths from 1230 to 3150 m. In particular the deeper sites (Chapopopte and Mictlan knolls) were characterized by asphalt deposits accompanied by extrusion of liquid oil in form of whips or sheets, and in some places (Tsanyao Yang, Mictlan, and Chapopote knolls) by gas emission and the presence of gas hydrates in addition. Molecular and stable carbon isotopic compositions of gaseous hydrocarbons suggest their primarily thermogenic origin. Relatively fresh asphalt structures were settled by chemosynthetic communities including bacterial mats and vestimentiferan tube worms, whereas older flows appeared largely inert and devoid of corals and anemones at the deep sites. The gas hydrates at Tsanyao Yang and Mictlan Knolls were covered by a 5-to-10 cm-thick reaction zone composed of authigenic carbonates, detritus, and microbial mats, and were densely colonized by 1-2 m-long tube worms, bivalves, snails, and shrimps. This study increased knowledge on the occurrences and dimensions of asphalt fields and associated gas hydrates at the Campeche Knolls. The extent of all discovered seepage structure areas indicates that emission of complex hydrocarbons is a widespread, thus important feature of the southern Gulf of Mexico.

  20. Subduction of the Tehuantepec oceanic fracture zone and the relationship with a seismic gap in southern Mexico

    NASA Astrophysics Data System (ADS)

    Constantin Manea, Vlad; Manea, Marina; Taras, Gerya; Valenzuela, Raul W.

    2016-04-01

    It is accepted that key constraints on the size and recurrence time of large subduction earthquakes originate from the degree of locking between the subducting and overriding plates. Since the interseismic locking degree is influenced by the rheological properties of crustal and mantle rocks, any variations along strike will result in significant changes in seismic behavior due to a change in frictional stability. Additionally, recent seismic studies show that the subduction of hydrothermally altered oceanic fracture zones induces strong pore-fluid pressure variations that control the degree of interseismic locking. The Mexico Subduction Zone (MSZ) is characterized by major along-strike changes in subduction geometry, as well as important structural variations of the incoming oceanic plate. One of the main tectonic features of the Cocos plate is the Tehuantepec fracture zone (FZ) that is currently subducting beneath southern Mexico. The analysis of seismicity revealed that the area around where Tehuantepec fracture zone is currently subducting is conspicuously quiet and considered a seismic gap. Here, no significant quake (Ms ≥ 7.0) has occurred in more than 100 years, and the origin of Tehuantepec Seismic Gap (TSG) has not been elucidated yet. Based on the dimensions of the Tehuantepec gap (125 km length and 80 km width), an earthquake of Mw = 8.0 may be possible. This study aims to shed some light on the relationship between the TSG with the subduction of Tehuantepec oceanic fracture zone. Previous studies show that the uppermost oceanic lithosphere beneath the Tehuantepec FZ is partially serpentinized due to seawater infiltrations along faults. Using high-resolution three-dimensional coupled petrological-thermomechanical numerical simulations specifically tailored for the subduction of the Tehuantepec FZ at MSZ we show that the weakened serpentinized fracture zone is partially scraped out in the forearc region because of its low strength and positive buoyancy

  1. Playa basin development, southern High Plains, Texas and New Mexico

    SciTech Connect

    Gustavson, T.C. ); Holliday, V.T. )

    1992-01-01

    More than 20,000 playa basins have formed on fine-grained eolian sediments of the Quaternary Blackwater Draw and Tertiary Ogallala Formations on the High Plains of TX and NM. Numerous hypotheses have been proposed for the development of playa basins: (1) subsidence due to dissolution of underlying Permian bedded salt, (2) dissolution of soil carbonate and piping of clastic sediment into the subsurface, (3) animal activity, and (4) deflation. Evidence of eolian processes includes lee dunes and straightened shorelines on the eastern and southern margins of many playas. Lee dunes, which occur on the eastern side of ca 15% of playa basins and contain sediment deflated from adjacent playas, are cresentic to oval in plain view and typically account for 15--40% of the volume of the playa basin. Quaternary fossil biotas and buried calcic soils indicate that grasslands and semi-arid to aid climatic conditions prevailed as these basins formed. Evidence of fluviolacustrine processes in playa basins includes centripetal drainage leading to fan deltas at playa margins and preserved deltaic and lacustrine sediments. Playa basins expanded as fluvial processes eroded basin slopes and carried sediment to the basin floor where, during periods of minimal vegetation cover, loose sediment was removed by deflation. Other processes that played secondary roles in the development of certain playa basins include subsidence induced by dissolution of deeply buried Permian salt, dissolution of soil carbonate and piping, and animal activity. Two small lake basins in Gray County, TX, occur above strata affected by dissolution-induced subsidence. Dissolution of soil carbonate was observed in exposures and cores of strata underlying playa basins. Cattle, and in the past vast numbers of migrating buffalo, destroy soil crusts in dry playas, making these sediments more susceptible to deflation, and carry sediment out of flooded playas on their hooves.

  2. Climatological Variability in Southern Mexico: the case of the Oaxaca Pacific Coastal Basins

    NASA Astrophysics Data System (ADS)

    Perez, N.; Kretzschmar, T.; Munoz-Arriola, F.; Cavazos, T.

    2010-12-01

    The precipitation regime of the southern coast of Mexico, particularly in Oaxaca, is characterized by a marked seasonal pattern, where most precipitation occurs during the summer with a bimodal distribution. The precipitation regime begins at the end of May, with two maxima, one in June and another between September and October. The minimum, between July and August is called the Mid Summer Drought (MSD). Periodic events, such as hurricanes, tropical storms and droughts occur in the region and cause considerable economical losses of one of the poorest states in Mexico. This study investigates the spatial and temporal variability in the annual and summer rainfall patterns in the Río Verde basin and two nearby coastal Oaxaca basins, Colotepec and Tonameca Rivers. The study evaluates local and global processes that may affect the climatic variability of these two basins. Locally, for example, climate regions are separated by physiographic effects and by response to phenomena such as ENSO and tropical cyclones. Also, it is important to notice that the warm pool of the eastern tropical Pacific is close to these basins and may have a strong influence on the rainfall patterns. At global scale, the behavior of precipitation during the ENSO and PDO positive and negative phases is analyzed. Obtained data from the Mexican Meteorological Agency (Servicio Meteorológico Nacional), database from the CLICOM system and from the National Water Commission. We analyzed 120 climatological stations with daily precipitation data. A quality control protocol was adopted, and stations with less than 70% of complete and correct data were discarded. A threshold of 4 standard deviations above the climatological mean was used to indentify daily outliers. Histogram analyses, a comparison with neighboring stations, and checks of the events were used to determine the validity of the outliers. The period of major continuity was 1961 to 1984. The study area is subdivided in regions using an PCA

  3. Miocene mollusks from the Simojovel area in Chiapas, southwestern Mexico

    NASA Astrophysics Data System (ADS)

    del Carmen Perrilliat, María; Vega, Francisco J.; Coutiño, Marco A.

    2010-11-01

    The fauna of gastropods and bivalves from the amber-bearing lithostratigraphic units of the Simojovel area, Chiapas is reported, including the description of two new species and one subspecies: Turbinella maya new species, Melongena corona tzeltal new subspecies and Agladrillia ( Eumetadrillia) vermeiji new species. Stratigraphic affinities of the previously described species suggest an Early Miocene age for the Mazantic Shale, and a Middle Miocene age for the overlying Balumtum Sandstone. One specimen of gastropod, with a relatively large piece of amber attached to the adapertural part of the shell is representative for an Early Miocene age and estuarine paleoenvironmental interpretation for the Mazantic Shale. Mollusca, Miocene, Chiapas, Amber, Mexico.

  4. Episodic tremor and slip along the Rivera and Cocos subduction zones of southern Mexico

    NASA Astrophysics Data System (ADS)

    Schlanser, K. M.; Brudzinski, M. R.; Kelly, N. J.; Grand, S. P.; Cabral-Cano, E.; Demets, C.; Kristen Schlanser, Mike Brudzinski, Nicholas Kelly, Steve Grand, Enrique Cabral-Cano, Alajendra Arciniega-Caballos, Oscar Diaz-Molina, Charles Demets

    2010-12-01

    The southern coast of Mexico is marked by active subduction of the Rivera and Cocos plates, producing frequent megathrust earthquakes with a 50-100 year recurrence. The variable convergence rate, subduction angle, and trench-to-coast distance affects the distribution of the seismogenic and transition zone, making an ideal study area for characterizing the relationship between earthquakes, nonvolcanic tremor (NVT) and slow slip events. Previous studies have shown that slow slip occurs in several areas across southern Mexico and may extend up-dip into the seismogenic zone, while NVT has been predominantly down-dip of these slow slip events in the Oaxaca and Guerrero regions. In Oaxaca, NVT is both more frequent, shorter in duration, and located further inland than the GPS-detected slow-slip, which in turn, is associated with a zone of ultra-slow velocity interpreted to represent high pore fluid pressure. This zone of slow-slip corresponds to approximately 350-450°C, with megathrust earthquakes, microseismicity, and long-term coupling occurring immediately up-dip from it. Initial NVT studies were based on a grid of stations in Oaxaca (OXNET) and a dense north-south line in Guerrero (MASE), but new OXNET instruments in eastern Guerrero and a deployment in the western states of Jalisco, Colima, and Michoacán (MARS) offer an opportunity to broaden understanding of these processes across the subduction zone. Using a semi-automated process identifying prominent energy bursts in envelope waveforms of this new data, analyst-refined relative arrival times are inverted for source locations using a 1-D velocity model. Previous results found NVT between the 40-50 km slab depth contours in western Oaxaca, with locations closer to the 30 km contour as the slab steepens in the east and locations primarily near the 60 km contours in central Guerrero as the slab shallows. Our analysis of new data in eastern Guerrero confirms a contiguous trend extends between the two previous

  5. Lithological and Petrographic Analyses of Carbonates and Sandstones From the Southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Garcia-Avendaño, A.; Urrutia-Fucugauchi, J.

    2012-04-01

    We present results of sedimentological and petrological studies of drill cores from the Bay of Campeche in the southern Gulf of Mexico. Based on reports on drill cores obtained from oil exploratory wells in the Cantarell Complex located 80 kilometres offshore in the Bay of Campeche and studies related to regional geology composite simplified stratigraphic columns for offshore Campeche region have been constructed up to depths of approximately 5000 m. The stratigraphic column is formed by a thick sediment sequence of Middle Jurassic age (evaporites, Callovian), Late Jurassic (terrigenous, calcareous clays and calcareous layers), Lower Cretaceous (carbonates), Upper Cretaceous-Paleogene (calcareous breccias), Paleogene-Neogene (terrigenous-carbonates intercalations) and Quaternary (terrigenous). The core samples studied come from wells in the Sihil and Akal fields in Cantarell. Analysis of reports on lithological descriptions indicates that these wells sample dolomitized sedimentary breccias from the Upper Cretaceous-Paleocene and fine-grained sandstones from the Late Jurassic Tithonian, respectively. Based on results of petrographic studies, the texture, cementing material and porosity of the units have been documented. The thin sections for carbonates were classified based on their texture according to Dunham (1962) for carbonate rocks, classified according to their components using the ternary diagrams of Folk (1974). Percentages refer to the data presented in tables, which were obtained by point-counting technique (with a total 250). Photomicrographs of scanning electron microscope (SEM) provide magnification for easy documentation of crystalline arrangements and description of micro-porous for different types of carbonates such as dolomite, in addition to the morphology of authigenic clays. Results of these studies and previous works in the area permit characterization of diagenetic processes of the carbonate sediments in the Campeche Bay, and provide

  6. Seismic Noise Studies of Urbanized Areas at Puerto Vallarta Mexico

    NASA Astrophysics Data System (ADS)

    Lara Huerta, K. C.; Escudero, C. R.; Gomez, A.; Madrigal, L.

    2014-12-01

    The application of seismic noise techniques in urbanized environment becomes a valuable tool to obtain information that is critical in areas exposed to earthquakes. Damage distribution during large earthquakes is frequently conditioned by site effects, in this way we determine site effect using ambient noise measurements in the area of Puerto Vallarta, Mexico. We focus our microtremor measurements to the estimation of a subsoil structure. To perform this we use three different techniques H/V spectral ratios, array measurements of microtremors applying the SPAC and F-k techniques. This work discusses the results that were obtained applying these techniques to the urbanized areas of Puerto Vallarta city. We present a series of maps showing the result as well as analyzed its application to risk assessment.

  7. 33 CFR 334.763 - Naval Support Activity Panama City; Gulf of Mexico; restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Naval Support Activity Panama City; Gulf of Mexico; restricted area. 334.763 Section 334.763 Navigation and Navigable Waters CORPS OF....763 Naval Support Activity Panama City; Gulf of Mexico; restricted area. (a) The area. The area...

  8. mtDNA and Y-chromosome polymorphisms in four Native American populations from southern Mexico

    SciTech Connect

    Torroni, A.; Chen, Yu.S.; Lott, M.T.; Wallace, D.C. ); Semino, O.; Santachiara-Beneceretti, A.S. ); Scott, C.R. ); Winter, M. )

    1994-02-01

    mtDNA sequence variation was examined in 60 Native Americans (Mixtecs from the Alta, Mixtecs from the Baja, Valley Zapotecs, and Highland Mixe) from southern Mexico by PCR amplification and high-resolution restriction endonuclease analysis. Four groups of mtDNA haplotypes (haplogroups A,B,C, and D) characterize Amerind populations. The comparison of their mtDNA variation with that observed in other populations from Mexico and Central America permits a clear distinction among the different Middle American tribes and raises questions about some of their linguistic affiliations. The males of these population samples were also analyzed for Y-chromosome RFLPs with the probes 49a, 49f, and 12f2. This analysis suggests that certain Y-chromosome haplotypes were brought from Asia during the colonization of the Americas, and a differential gene flow was introduced into Native American populations from European males and females. 31 refs., 4 figs., 5 tabs.

  9. Hydrogeochemical data for thermal and nonthermal waters and gases of the Valles Caldera- southern Jemez Mountains region, New Mexico

    SciTech Connect

    Shevenell, L.; Goff, F.; Vuataz, F.; Trujillo, P.E. Jr.; Counce, D.; Janik, C.J.; Evans, W.

    1987-03-01

    This report presents field, chemical, gas, and isotopic data for thermal and nonthermal waters of the southern Jemez Mountains, New Mexico. This region includes all thermal and mineral waters associated with Valles Caldera and many of those located near the Nacimiento Uplift, north of San Ysidro. Waters of the region can be categorized into five general types: (1) surface and near-surface meteoric waters; (2) acid-sulfate waters at Sulphur Springs (Valles Caldera); (3) thermal meteoric waters in the ring fracture zone (Valles Caldera); (4) deep geothermal waters of the Baca geothermal field and derivative waters in the Soda Dam and Jemez Springs area (Valles Caldera); and (5) mineralized waters near San Ysidro. Some waters display chemical and isotopic characteristics intermediate between the types listed. Data in this report will help in interpreting the geothermal potential of the Jemez Mountains region and will provide background for investigating problems in hydrology, structural geology, hydrothermal alterations, and hydrothermal solution chemistry.

  10. Current (2004-07) Conditions and Changes in Ground-Water Levels from Predevelopment to 2007, Southern High Plains Aquifer, East-Central New Mexico-Curry County, Portales, and Causey Lingo Underground Water Basins

    USGS Publications Warehouse

    Tillery, Anne

    2008-01-01

    The Southern High Plains aquifer is the principal aquifer in Curry and Roosevelt Counties, N. Mex., and primary source of water in southeastern New Mexico. Successful water-supply planning for New Mexico's Southern High Plains requires knowledge of the current aquifer conditions and a context to estimate future trends given current aquifer-management policy. This report provides a summary of the current (2007) water-level status of the Southern High Plains aquifer in New Mexico, including a basis for estimating future trends by comparison with historical conditions. This report includes estimates of the extent of ground-water level declines in the Curry County, Portales, and Causey-Lingo Ground-water Management Area parts of the High Plains Aquifer in eastern New Mexico since predevelopment. Maps representing 2007 water levels, water-level declines, aquifer saturated thickness, and depth to water accompanied by hydrographs from representative wells for the Southern High Plains aquifer in the Curry County, Portales, and Causey Lingo Underground Water Basins were prepared in cooperation with the New Mexico Office of the State Engineer. The results of this mapping show the water level declined as much as 175 feet in the study area at rates as high as 1.76 feet per year.

  11. GPS constraints on the Mw = 7.5 Ometepec earthquake sequence, southern Mexico: coseismic and post-seismic deformation

    NASA Astrophysics Data System (ADS)

    Graham, Shannon E.; DeMets, Charles; Cabral-Cano, Enrique; Kostoglodov, Vladimir; Walpersdorf, Andrea; Cotte, Nathalie; Brudzinski, Michael; McCaffrey, Robert; Salazar-Tlaczani, Luis

    2014-10-01

    We use continuous GPS measurements from 31 stations in southern Mexico to model coseismic slip and post-seismic deformation from the 2012 March 20 Mw = 7.5 Ometepec earthquake, the first large thrust earthquake to occur below central Mexico during the modern GPS era. Coseismic offsets ranging from ˜280 mm near the epicentre to 5 mm or less at sites far from the epicentre are fit best by a rupture focused between ˜15 and 35 km depth, consistent with an independent seismological estimate. The corresponding geodetic moment of 1.4 × 1020 N·m is within 10 per cent of two independent seismic estimates. Transient post-seismic motion recorded by GPS sites as far as 300 km from the rupture has a different horizontal deformation gradient and opposite sense of vertical motion than do the coseismic offsets. A forward model of viscoelastic relaxation as a result of our new coseismic slip solution incorrectly predicts uplift in areas where post-seismic subsidence was recorded and indicates that viscoelastic deformation was no more than a few per cent of the measured post-seismic deformation. The deformation within 6 months of the earthquake was thus strongly dominated by fault afterslip. The post-seismic GPS time-series are well fit as logarithmically decaying fault afterslip on an area of the subduction interface up to 10 times larger than the earthquake rupture zone, extending as far as 220 km inland. Afterslip had a cumulative geodetic moment of 2.0 × 1020 N·m, ˜40 per cent larger than the Ometepec earthquake. Tests for the shallow and deep limits for the afterslip require that it included much of the earthquake rupture zone as well as regions of the subduction interface where slow slip events and non-volcanic tremor have been recorded and areas even farther downdip on the flat interface. Widespread afterslip below much of central Mexico suggests that most of the nearly flat subduction interface in this region is conditionally stable and thus contributes measurable

  12. GPS Constraints on the Mw=7.5 Ometepec Earthquake Sequence, Southern Mexico: Coseismic and Postseismic Deformation

    NASA Astrophysics Data System (ADS)

    Graham, S. E.; DeMets, C.; Cabral, E.; Kostoglodov, V.; Walpersdorf, A.; Cotte, N.; Brudzinski, M. R.; McCaffrey, R.; Salazar-Tlaczani, L.

    2014-12-01

    We use continuous GPS measurements from 31 stations in southern Mexico to model coseismic slip and postseismic deformation from the 20 March 2012 Mw=7.5 Ometepec earthquake, the first large thrust earthquake to occur below central Mexico during the modern GPS era. Coseismic offsets ranging from ~280 mm near the epicenter to 5 mm or less at sites far from the epicenter are fit best by a rupture focused between ~15 km and 35 km depth, consistent with an independent seismological estimate. Transient postseismic motion recorded by GPS sites as far as 300 km from the rupture has a different horizontal deformation gradient and opposite sense of vertical motion than do the coseismic offsets. A forward model of viscoelastic relaxation as a result of our new coseismic slip solution incorrectly predicts uplift in areas where postseismic subsidence was recorded and indicates that viscoelastic deformation was no more than a few percent of the measured postseismic deformation. The deformation within six months of the earthquake was thus strongly dominated by fault afterslip. The postseismic GPS time series are well fit as logarithmically decaying fault afterslip on an area of the subduction interface up to 10 times larger than the earthquake rupture zone, extending as far as 220 km inland. Afterslip had a cumulative geodetic moment of 2.0×1020 N·m, ~40% larger than the Ometepec earthquake. Tests for the shallow and deep limits for the afterslip require that it included much of the earthquake rupture zone as well as regions of the subduction interface where slow slip events and non-volcanic tremor have been recorded and areas even farther downdip on the flat interface. We examine whether aftershocks accommodated a significant fraction of the shallow postseismic slip, but find that the energy released by aftershocks accounted for no more than 10% of the postseismic moment release at any depth. Widespread afterslip below much of central Mexico suggests that most of the nearly

  13. El Niño-southern oscillation effect on a fire regime in northeastern Mexico has changed over time.

    PubMed

    Yocom, Larissa L; Fulé, Peter Z; Brown, Peter M; Cerano, Julian; Villanueva-Díaz, José; Falk, Donald A; Cornejo-Oviedo, Eladio

    2010-06-01

    The El Niño Southern Oscillation (ENSO) is a climate-forcing mechanism that has been shown to affect precipitation and the occurrence of wildfires in many parts of the world. In the southern United States and northern Mexico, warm events (El Niño) are associated with moist winter conditions and fewer fires, while cool events (La Niñia) tend to favor dry winters and more fires. We tested this relationship in a region of northeastern Mexico by characterizing the historical fire regime and climatic influences: Fire regimes were reconstructed from fire-scar samples collected from 100 trees in three high-elevation sites on Peña Nevada in southern Nuevo Le6n. The sites were approximately 25 ha each, and the site centers were approximately 1 km apart. The earliest recorded fire occurred in 1521 and the time period we used for analysis was 1645-1929. The sites were characterized by frequent surface fires before the 1920s. In the three sites, mean fire intervals ranged from 8.6 to 9.6 years (all fires) and 11.9 to 18.6 years (fires that scarred > or = 25% of recording trees). The per-tree mean fire return interval was 17 years, and all three sites burned in the same year seven times between 1774 and 1929. After 1929, fires were nearly eliminated in all sites, likely due to human causes. We found a temporal change in the association between ENSO events and fires; before the 1830s La Niña events were significantly associated with fire years, while after the 1830s this association was not significant. In 1998, when the most severe El Niño event of the past century occurred, the three sites experienced severe, stand-replacing fires that killed many trees that had survived multiple surface fires in the past. Prior to the 1830s, fires tended to occur during dry La Niña years, but since then both La Niña and El Niño have been associated with dry years in this region, especially during the last three decades. This result suggests that ENSO effects have changed over time in

  14. CHAMA-SOUTHERN SAN JUAN MOUNTAINS WILDERNESS STUDY AREA, COLORADO.

    USGS Publications Warehouse

    Brock, Maurice R.; Lindquist, Alec E.

    1984-01-01

    A mineral survey of the Chama-southern San Juan Mountains Wilderness study area in Colorado revealed demonstrated coal resources in an area of substantiated coal resource potential and areas of probable resource potential for petroleum and metals including molydenum, copper, zinc, lead, and silver. The coal deposit that underlies the northwestern part of the study area at its westernmost extension requires further study for a more accurate determination of the coal resources that underlie the area. Drilling also is required to determine depth, magnitude, and tenor of the postulated porphyry deposit containing copper and molybdenum in the northernmost part of the study area. Geophysical surveys and detailed geologic mapping in advance of drilling are needed in the areas delineated as having potential for oil and gas resources.

  15. Seismic structure along transitions from flat to normal subduction: central Mexico, southern Peru, and southwest Japan

    NASA Astrophysics Data System (ADS)

    Dougherty, Sara L.

    The fine-scale seismic structure of the central Mexico, southern Peru, and southwest Japan subduction zones is studied using intraslab earthquakes recorded by temporary and permanent regional seismic arrays. The morphology of the transition from flat to normal subduction is explored in central Mexico and southern Peru, while in southwest Japan the spatial coincidence of a thin ultra-slow velocity layer (USL) atop the flat slab with locations of slow slip events (SSEs) is explored. This USL is also observed in central Mexico and southern Peru, where its lateral extent is used as one constraint on the nature of the flat-to-normal transitions. In western central Mexico, I find an edge to this USL which is coincident with the western boundary of the projected Orozco Fracture Zone (OFZ) region. Forward modeling of the 2D structure of the subducted Cocos plate using a finite-difference algorithm provides constraints on the velocity and geometry of the slab's seismic structure in this region and confirms the location of the USL edge. I propose that the Cocos slab is currently fragmenting into a North Cocos plate and a South Cocos plate along the projection of the OFZ, by a process analogous to that which occurred when the Rivera plate separated from the proto-Cocos plate 10 Ma. In eastern central Mexico, observations of a sharp transition in slab dip near the abrupt end of the Trans Mexican Volcanic Belt (TMVB) suggest a possible slab tear located within the subducted South Cocos plate. The eastern lateral extent of the USL is found to be coincident with these features and with the western boundary of a zone of decreased seismicity, indicating a change in structure which I interpret as evidence of a possible tear. Analysis of intraslab seismicity patterns and focal mechanism orientations and faulting types provides further support for a possible tear in the South Cocos slab. This potential tear, together with the tear along the projection of the OFZ to the northwest

  16. Kinematics and age of Early Tertiary trench parallel volcano-tectonic lineaments in southern Mexico: Tectonic implications

    NASA Astrophysics Data System (ADS)

    Martini, M.; Ferrari, L.; Lopez Martinez, M.; Cerca Martinez, M.; Serrano Duran, L.

    2007-05-01

    We present new geological, structural, and geochronological data that constrain the timing and geometry of Early Tertiary strike slip deformation in southwestern Mexico and its relation with the concurrent magmatic activity. Geologic mapping in Guerrero and Michoacan States documented two regional WNW trending volcano-tectonic lineaments sub parallel to the present trench. The southernmost lineament runs for ~140 km from San Miguel Totolapan area (NW Guerrero) to Sanchiqueo (SE Michoacan), and passes through Ciudad Altamirano. Its southeastern part is marked by the alignment of at least eleven silicic to intermediate major domes as well as by the course of the Balsas River. The northwestern part of the lineament is characterized by ductile left lateral shear zones in Early Tertiary plutonic rocks observed in the Rio Chiquito valley. Domes near Ciudad Altamirano are unaffected by ductile shearing and yielded a ~42 Ma 40Ar/39Ar age, setting a minimum age for this deformation. The northern volcano-tectonic lineament runs for ~190 km between the areas of Huitzuco in northern Guerrero and the southern part of the Tzitzio fold in eastern Michoacan. The Huautla, Tilzapotla, Taxco, La Goleta and Nanchititla silicic centers (all in the range 37-34 Ma) are emplaced along this lineament, which continues to the WNW trough a mafic dike swarm exposed north of Tiquicheo (37-35 Ma) and the Purungueo subvolcanic body (~42 Ma). These rocks, unaffected by ductile shearing, give a minimum age of deformation similar to the southern Totolapan-Sanquicheo lineament. Post ~42 Ma deformation is essentially brittle and is characterized by several left lateral and right lateral transcurrent faults with typical Riedel patterns. Other trench-parallel left lateral shear zones active in pre-Oligocene times were recently reported in western Oaxaca. The recognizing of Early Tertiary trench-parallel and left-lateral ductile shearing in internal areas of southern Mexico suggest a field of widely

  17. Mexico.

    ERIC Educational Resources Information Center

    Semaan, Leslie

    The text explores Mexico's history, geography, art, religion, and lifestyles in the context of its complex economy. The text focuses on Mexico's economy and reasons for its current situation. Part I of this teaching unit includes: Teacher Overview, Why Study Mexico, Mexico Fact Sheet, Map of Mexico, the Land and Climate, History, Government,…

  18. Effectiveness of protected areas in mitigating fire within their boundaries: case study of Chiapas, Mexico.

    PubMed

    Román-Cuesta, María Rosa; Martínez-Vilalta, Jordi

    2006-08-01

    Since the severe 1982-1983 El Niño drought, recurrent burning has been reported inside tropical protected areas (TPAs). Despite the key role of fire in habitat degradation, little is known about the effectiveness of TPAs in mitigating fire incidence and burned areas. We used a GPS fire database (1995-2005) (n=3590 forest fires) obtained from the National Forest Commission to compare fire incidence (number of fires) and burned areas inside TPAs and their surrounding adjacent buffer areas in Southern Mexico (Chiapas). Burned areas inside parks ranged from 2% (Palenque) to 45% (Lagunas de Montebello) of a park's area, and the amount burned was influenced by two severe El Niño events (1998 and 2003). These two years together resulted in 67% and 46% of the total area burned in TPAs and buffers, respectively during the period under analysis. Larger burned areas in TPAs than in their buffers were exclusively related to the extent of natural habitats (flammable area excluding agrarian and pasture lands). Higher fuel loads together with access and extinction difficulties were likely behind this trend. A higher incidence of fire in TPAs than in their buffers was exclusively related to anthropogenic factors such as higher road densities and agrarian extensions. Our results suggest that TPAs are failing to mitigate fire impacts, with both fire incidence and total burned areas being significantly higher in the reserves than in adjacent buffer areas. Management plans should consider those factors that facilitate fires in TPAs: anthropogenic origin of fires, sensitivity of TPAs to El Niñio-droughts, large fuel loads and fuel continuity inside parks, and limited financial resources. Consideration of these factors favors lines of action such as alternatives to the use of fire (e.g., mucuna-maize system), climatic prediction to follow the evolution of El Niño, fuel management strategies that favor extinction practices, and the strengthening of local communities and ecotourism

  19. 33 CFR 334.720 - Gulf of Mexico, south from Choctawhatchee Bay; Missile test area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Gulf of Mexico, south from... the Gulf of Mexico south from Choctawhatchee Bay within an area described as follows: Beginning at a..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.720 Gulf...

  20. 33 CFR 334.720 - Gulf of Mexico, south from Choctawhatchee Bay; Missile test area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Gulf of Mexico, south from... the Gulf of Mexico south from Choctawhatchee Bay within an area described as follows: Beginning at a..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.720 Gulf...

  1. 33 CFR 334.720 - Gulf of Mexico, south from Choctawhatchee Bay; Missile test area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Gulf of Mexico, south from... the Gulf of Mexico south from Choctawhatchee Bay within an area described as follows: Beginning at a..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.720 Gulf...

  2. Cenomanian-Turonian facies succession in the Guerrero-Morelos Basin, Southern Mexico

    NASA Astrophysics Data System (ADS)

    Aguilera-Franco, Noemí; Hernández Romano, Ulises

    2004-09-01

    The Cenomanian-Turonian succession of southern Mexico is characterized by an abrupt change from shallow marine to pelagic facies. The drowning of the platform coincides with the widely documented Cenomanian-Turonian Oceanic Anoxic Event (CTOAE). A proper understanding of the drowning event and the effects of the OAE requires, as an essential first step, the construction of a detailed stratigraphic framework. This has been achieved and utilizes sedimentological data as well as a combination of benthic and planktonic biostratigraphic schemes. Deposition of the Cenomanian-Turonian sedimentary rocks of the Guerrero-Morelos basin was controlled by tectonic and oceanographic factors resulting in depositional environments ranging from a semi-restricted shelf, ramp, pelagic and prodelta deposits. Facies analysis indicates that shallow marine limestones of the Morelos Formation (lower-upper Cenomanian) were deposited in intertidal-shallow supratidal and subtidal environments in a semi-restricted shelf. Peloidal-bioclastic packstone-wackestones with minor grainstones are the predominant texture of these rocks. Abundant large benthic foraminifers, calcareous algae (dasycladacean) and mollusks (gastropods and rudists) characterize the fossil assemblage. The Cuautla Formation (uppermost Cenomanian-Turonian) represents sedimentation on a low-energy, wave-dominated, carbonate ramp. The inner ramp accumulated bioclastic banks and shoals composed of peloidal-benthic foraminifer-grainstone, calcareous red and green algae, rudists and minor solitary corals. The middle ramp is represented by nodular packstones with a diverse assemblage of echinoderms, green and red algae, bryozoan, rudists, solitary corals, roveacrinids, calcisphaerulids, and non-keeled planktonic foraminifers. The outer ramp is dominated by argillaceous wackestone-packstone characterized by calcisphaerulids, roveacrinids, and non-keeled planktonic foraminifers. An increase in terrigenous-clastic material towards the

  3. Educating "Barbaros": Educational Policies on the Latin American Frontiers between Colonies and Independent Republics (Araucania, Southern Chile/Sonora, Mexico)

    ERIC Educational Resources Information Center

    Holck, Lasse; Saiz, Monika Contreras

    2010-01-01

    This article compares the methods and means employed by the state to enforce the education of (semi-)autonomous indigenous groups in southern Chile and northwestern Mexico (Sonora), border regions in the Latin American periphery, covering the transition from colonial times to the consolidation of independent republics until the middle of the…

  4. Survey of Political Participation, Employment, and Demographic Characteristics of Eleven Counties in Southern New Mexico. Volume II.

    ERIC Educational Resources Information Center

    New Mexico State Advisory Committee to the U.S. Commission on Civil Rights, Santa Fe.

    The report briefly outlines the population characteristics, public employment and political representation status of the Dona Ana, Grant, Hidalgo, Luna, Otero, and Sierra counties in southern New Mexico for a 10-year period. The three sections of each profile focus on the city government, largest city in that county, and school district…

  5. Survey of Political Participation, Employment and Demographic Characteristics of Eleven Counties in Southern New Mexico. Volume I.

    ERIC Educational Resources Information Center

    New Mexico State Advisory Committee to the U.S. Commission on Civil Rights, Santa Fe.

    The report briefly outlines the population characteristics, public employment and political representation status of the Chaves, Curry, Eddy, Lea, and Roosevelt counties in southern New Mexico for a 10-year period. The three sections of each profile focus on the county government, largest city in that county, and school district encompassing that…

  6. Tracing the lateral movement of sediments through a shrubland environment using fallout radionuclides, Jornada Basin, Southern New Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Semi-arid grassland and savanna communities in many parts of the world have been displaced by woody shrubs. In the Jornada Basin of southern New Mexico, the displacement of perennial grasslands is well documented beginning in 1858. As shrubs invade semi-arid perennial grasslands, the length, number,...

  7. A micrometeorological data base for the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Salcido, A.; Celada-Murillo, A. T.; Villegas-Martínez, R.; Salas-Oviedo, H.; Sozzi, R.; Georgiadis, T.

    2003-05-01

    In order to overcome the lack of the surface micrometeorological data required for air quality studies in the Mexico City Metropolitan Area (MCMA), a long-term micrometeorological campaign was carried out in this area along the 2001-year. Three micrometeorological surface stations were installed at sites located at north, north-east, and south sectors of the MCMA. Each station was equipped with a 3D ultrasonic turbulence sensor and with conventional meteorological sensors for temperature, relative humidity, pressure, global radiation, net radiation, and rain. The sampling rates were 10 Hz for the ultrasonic sensor, and 1 Hz for the conventional sensors. One-hour averages were calculated for all the meteorological parameters and for the turbulence parameters such as friction velocity, scale temperature, Monin-Obukhov length, sensible heat flux and turbulent kinetic energy, among others. A simple micrometeorological database was prepared and mounted on a free access Internet page to furnish a specialized tool to the local Authorities to be utilized in health prevention and pollution regulation applications.

  8. Hydrology of Area 62, Northern Great Plains and Rocky Mountain Coal Provinces, New Mexico and Arizona

    USGS Publications Warehouse

    Roybal, F.E.; Wells, J.G.; Gold, R.L.; Flager, J.V.

    1984-01-01

    This report summarizes available hydrologic data for Area 62 and will aid leasing decisions, and the preparation and appraisal of environmental impact studies and mine-permit applications. Area 62 is located at the southern end of the Rocky Mountain Coal Province in parts of New Mexico and Arizona and includes approximately 9,500 square miles. Surface mining alters, at least temporarily, the environment; if the areas are unreclaimed, there can be long-term environmental consequences. The land-ownership pattern in Area 62 is complicated. The checkerboard pattern created by several types of ownership makes effective management of these lands difficult. The climate generally is semiarid with average annual precipitation ranging from 10 to 20 inches. Pinons, junipers, and grasslands cover most of the area, and much of it is used for grazing by livestock. Soils vary with landscape, differing from flood plains and hillslopes to mountain slopes. The major structural features of this area were largely developed during middle Tertiary time. The main structural features are the southern San Juan Basin and the Mogollon slope. Coal-bearing rocks are present in four Cretaceous rock units of the Mesaverde Group: the Gallup Sandstone, the Dileo Coal Member, and the Gibson Coal Member of the Crevasse Canyon Formation, and the Cleary Coal Member of the Menefee Formation. Area 62 is drained by Black Creek, the Puerco River, the Zuni River, Carrizo Wash-Largo Creek, and the Rio San Jose. Only at the headwaters of the Zuni River is the flow perennial. The streamflow-gaging station network consists of 25 stations operated for a variety of needs. Streamflow changes throughout the year with variation related directly to rainfall and snowmelt. Base flow in Area 62 is zero indicating no significant ground-water discharge. Mountainous areas contribute the highest mean annual runoff of 1.0 inch. Very few water-quality data are available for the surface-water stations. Of the nine surface

  9. Dispersal of Male Aedes aegypti in a Coastal Village in Southern Mexico

    PubMed Central

    Valerio, Laura; Facchinelli, Luca; Ramsey, Janine M.; Scott, Thomas W.

    2012-01-01

    Most Aedes aegypti dispersal studies have focused on females because of their central role in dengue virus transmission. Only a few mark-release-recapture (MRR) studies provided insights into male Ae. aegypti dispersal. To fill this knowledge gap, we conducted five male Ae. aegypti MRR experiments in a coastal village in southern Mexico. Small and large male cohorts were marked with fluorescent dusts, released outside buildings, and recaptures were carried out by using backpack aspirators. Recapture rates ranged between 0.35% and 6.55% and median distance traveled was 12–166 meters. A statistically significant difference in median distance traveled with large males dispersing farther than small ones was detected only in one experiment (MRR5: U = 3.5, P < 0.01). Male dispersal data will be useful for constructing and estimating parameter values and validating models that will be used to plan the most effective release strategies for genetically modified male Ae. aegypti. PMID:22492152

  10. Preliminary Analysis of AVIRIS Data for Tectonostratigraphic Assessment of Northern Guerrero State, Southern Mexico

    NASA Technical Reports Server (NTRS)

    Lang, Harold R.; Cabral-Cano, Enrique

    1996-01-01

    The tectonostratigraphic evolution of the southern margin of the North America Plate in Mexico is still in debate. Recent explanations assert Laramide age (Campanian-Eocene) accretion of far-travelled oceanic terranes. In 1989, we began an effort to bring new data to this debate through field mapping, incorporating Landsat Thematic Mapper and digital elevation data, along a 30 km by 250 km, east-west geologic transect of northern Guerrero State. Covering the region from Huetamo, Michoacan, to Papalutla, Guerrero (between latitude 18-19 deg N and longitude 101-99 deg W), our mapping results show that no stratigraphic incompatibilities suggesting terrane accretion exist in the region. In November 1994, AVIRIS data were acquired along the geologic transect in order to refine our stratigraphic assessment. One objective of this hyperspectral survey was to improve mapping of limestone, dolostone and gypsum-bearing facies of the Morelos Formation which record rudist carbonate platform environments during mid-Cretaceous time.

  11. Organochlorine pesticides and PCBs in air of southern Mexico (2002-2004)

    NASA Astrophysics Data System (ADS)

    Alegria, Henry A.; Wong, Fiona; Jantunen, Liisa M.; Bidleman, Terry F.; Figueroa, Miguel Salvador; Bouchot, Gerardo Gold; Moreno, Victor Ceja; Waliszewski, Stefan M.; Infanzon, Raul

    Air samples were collected in southern Mexico in 2002-2004 to determine the extent of contamination with organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). The ΣDDTs ranged from 239 to 2360 pg m -3. Other prominent OC pesticides were endosulfans, toxaphene and lindane. Pesticides detected in lower concentrations include chlordanes, dieldrin, and heptachlor. Proportions of DDT compounds suggested fresh use of DDT in some locations and a mix of fresh and aged residues at others. Ratios of trans-chlordane/ cis-chlordane were consistent with fresh chlordane usage or emission of residues from former termiticide applications. The ΣPCBs was relatively low at all sites. Concentrations of OC pesticides measured with passive samplers agreed well with those measured using high-volume samplers. Air back trajectory analysis suggests a complex pattern of regional atmospheric transport.

  12. Dispersal of male Aedes aegypti in a coastal village in southern Mexico.

    PubMed

    Valerio, Laura; Facchinelli, Luca; Ramsey, Janine M; Bond, J Guillermo; Scott, Thomas W

    2012-04-01

    Most Aedes aegypti dispersal studies have focused on females because of their central role in dengue virus transmission. Only a few mark-release-recapture (MRR) studies provided insights into male Ae. aegypti dispersal. To fill this knowledge gap, we conducted five male Ae. aegypti MRR experiments in a coastal village in southern Mexico. Small and large male cohorts were marked with fluorescent dusts, released outside buildings, and recaptures were carried out by using backpack aspirators. Recapture rates ranged between 0.35% and 6.55% and median distance traveled was 12-166 meters. A statistically significant difference in median distance traveled with large males dispersing farther than small ones was detected only in one experiment (MRR5: U = 3.5, P < 0.01). Male dispersal data will be useful for constructing and estimating parameter values and validating models that will be used to plan the most effective release strategies for genetically modified male Ae. aegypti. PMID:22492152

  13. 77 FR 59223 - Extension of Post-Sale Evaluation Period for Consolidated Central Gulf of Mexico Planning Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ... of Mexico Planning Area Lease Sale 216/222 AGENCY: Bureau of Ocean Energy Management (BOEM), Interior..., 2012, the post-sale evaluation period for Consolidated Central Gulf of Mexico Planning Area Lease...

  14. Organchlorine content and shell thickness in brown booby (Sula leucogaster) eggs in the Gulf of California and the southern Pacific coast of Mexico.

    PubMed

    Mellink, Eric; Riojas-López, Mónica E; Luévano-Esparza, Jaime

    2009-07-01

    We determined egg concentrations of organochlorines and thickness of eggshells from brown boobies at eight colonies ranging from the northern Gulf of California to southern Mexico. The only common residue was that of DDE, which was found in almost all eggs. DDE content apparently reflected pre-1990 DDT use in nearby agricultural areas and, at one site, intensive mosquito control for high-end tourism development. There were no inter-colony differences in eggshell thickness, and variation in this variable likely reflected individual bird characteristics and/or individual feeding source. This variable was not a good proxy to DDE exposure of brown boobies, under current DDE levels in the brown booby trophic chain. In the northern Gulf of California, eggshell thickness has recovered to pre-DDT conditions. Our data indicate that the Gulf of California and southwestern coast of Mexico have a healthy near-shore marine environment, as far as organochlorines are concerned. PMID:19356832

  15. Seismic Anisotropy and Mantle Flow Driven by the Cocos Slab Under Southern Mexico

    NASA Astrophysics Data System (ADS)

    Bernal-López, Leslie A.; Garibaldi, Berenice R.; León Soto, Gerardo; Valenzuela, Raúl W.; Escudero, Christian R.

    2015-12-01

    Shear wave splitting measurements were made using SKS and SKKS waves recorded by the Meso-American Subduction Experiment, which was deployed in southern Mexico starting at the coast of the Pacific Ocean and running north toward the Gulf of Mexico. In this segment of the Middle America Trench the oceanic Cocos plate subducts under the continental North American plate. The active volcanic arc is located at the southern end of the Trans-Mexican Volcanic Belt. Unlike most subduction zones, however, the volcanic arc is not subparallel to the trench. In the fore-arc, between the trench and the Trans-Mexican Volcanic Belt, the Cocos slab subducts subhorizontally. Beneath the volcanic belt, however, the slab dives steeply into the mantle. A marked difference in the orientation of the fast polarization directions is observed between the fore-arc and the back-arc. In the fore-arc the fast axes determined using SKS phases are oriented NE-SW, in the same direction as the relative motion between the Cocos and North American plates, and are approximately perpendicular to the trench. Physical conditions in the subslab mantle are consistent with the existence of A-type olivine and consequently entrained mantle flow is inferred. Strong coupling between the slab and the surrounding mantle is observed. In the back-arc SKS fast polarization directions are oriented N-S and are perpendicular to the strike of the slab. Given the high temperatures in the mantle wedge tip, the development of A-type, or similar, olivine fabric throughout the mantle wedge is expected. The orientation of the fast axes is consistent with corner flow in the mantle wedge.

  16. mtDNA and Y-chromosome polymorphisms in four Native American populations from southern Mexico.

    PubMed Central

    Torroni, A.; Chen, Y. S.; Semino, O.; Santachiara-Beneceretti, A. S.; Scott, C. R.; Lott, M. T.; Winter, M.; Wallace, D. C.

    1994-01-01

    mtDNA sequence variation was examined in 60 Native Americans (Mixtecs from the Alta, Mixtecs from the Baja, Valley Zapotecs, and Highland Mixe) from southern Mexico by PCR amplification and high-resolution restriction endonuclease analysis. Four groups of mtDNA haplotypes (haplogroups A, B, C, and D) characterize Amerind populations, but only three (haplogroups A, B, and C) were observed in these Mexican populations. The comparison of their mtDNA variation with that observed in other populations from Mexico and Central America permits a clear distinction among the different Middle American tribes and raises questions about some of their linguistic affiliations. The males of these population samples were also analyzed for Y-chromosome RFLPs with the probes 49a, 49f, and 12f2. This analysis suggests that certain Y-chromosome haplotypes were brought from Asia during the colonization of the Americas, and a differential gene flow was introduced into Native American populations from European males and females. Images Figure 4 PMID:8304347

  17. Alaska Humans Factors Safety Study: The Southern Coastal Area

    NASA Technical Reports Server (NTRS)

    Chappell, Sheryl L.; Reynard, William (Technical Monitor)

    1995-01-01

    At the request of the Alaska Air Carriers Association, researchers from the NASA Aviation Safety Reporting System, at NASA Ames Research Center, conducted a study on aspects of safety in Alaskan Part 135 air taxi operations. An interview form on human factors safety issues was created by a representative team from the FAA-Alaska, NTSB-Alaska, NASA-ASRS, and representatives of the Alaska Air Carriers Association which was subsequently used in the interviews of pilots and managers. Because of the climate and operational differences, the study was broken into two geographical areas, the southern coastal areas and the northern portion of the state. This presentation addresses the southern coastal areas, specifically: Anchorage, Dillingham, King Salmon, Kodiak, Cold Bay, Juneau, and Ketchikan. The interview questions dealt with many of the potential pressures on pilots and managers associated with the daily air taxi operations in Alaska. The impact of the environmental factors such as the lack of available communication, navigation and weather information systems was evaluated. The results of this study will be used by government and industry working in Alaska. These findings will contribute important information on specific Alaska safety issues for eventual incorporation into training materials and policies that will help to assure the safe conduct of air taxi flights in Alaska.

  18. Emissions inventory for the Mexico City Metropolitan Area

    SciTech Connect

    Figueroa, V.H.P.; Renteria, J.S.; Hernandez, C.G.

    1996-12-31

    The emissions inventory bears a broad relationship to the energy balance, reflecting the dependence of the emissions with reference to the use of energy. Actually the consumption of gasoline and diesel fuel in the transport sector represents collectively, the greatest comparative expense of energy and the major contributor of the ozone precursor pollutants HC, NO{sub x} and CO, relative to the total volume of emissions in the Mexico City Metropolitan Area (MCMA). Also, the industrial sector introduces significant emissions of SO{sub 2} and NO{sub x} due to its energy consumption of fuel oils and natural gas. In contrast, the great majority of suspended particulate in the MCMA emanate from degradation processes of surface soil along the periphery of the urban zone. To the federal and local authorities charged with the design of strategies for prevention and control of atmospheric pollution, the emissions inventory is a strategic tool that reflects the relative intensity of the various emitters to the load capacity of the atmosphere. A comprehensive inventory was compiled for 1995, categorizing the emissions generated by four sectors: industry, services, transport and surface soils and vegetation, considering the following pollutants: TSP, SO{sub 2}, NO{sub x}, HC and CO. The combined pollutant emissions are 4,009,628 tons/year of which 3% are generated by the industry, 10% by the services sector, 75% by the transport sector, and 12% by surface soils and vegetation.

  19. Areas of localized organochlorine contamination in Arizona and New Mexico

    USGS Publications Warehouse

    Fleming, W.J.; Cain, B.W.

    1985-01-01

    Wings from mallard ducks harvested in 1980 in Arizona, Arkansas, Louisiana, and New Mexico were pooled into county aggregates and analyzed for organochlorine pesticides and PCB's. Organochlorine concentrations in duck wings were compared among counties comprising major river drainages within each state. DDE concentrations in the wings of mallards collected from the Verde River and the lower portion of the Gila River drainages in Arizona ranged up to 6 ppm (wet weight basis), which was 17 times higher than the 1979 Pacific Flyway average. DDE at these high levels may be hazardous to wildlife. In combination with other published data, our findings indicate a serious DDT problem in portions of the Verde River and Gila River drainages. High levels of heptachlor (up to 1.7 ppm) and PCB's (3.7 ppm, 61 times the 1979 Central Flyway average) were found in mallard wings from the upper Rio Grande and Pecos River drainages, respectively. We did not detect areas of heavy local organochlorine pesticide or PCB contamination in Arkansas and Louisiana.

  20. Bollgard cotton and resistance of tobacco budworm (Lepidoptera: Noctuidae) to conventional insecticides in southern Tamaulipas, Mexico.

    PubMed

    Terán-Vargas, A P; Rodríguez, J C; Blanco, C A; Martínez-Carrillo, J L; Cibrián-Tovar, J; Sánchez-Arroyo, H; Rodríguez-del-Bosque, L A; Stanley, D

    2005-12-01

    Insecticide susceptibility in tobacco budworm, Heliothis virescens (F.) (Lepidoptera: Noctuidae), was determined for 8 yr (1991-2001) with larvae sampled from cotton in southern Tamaulipas, Mexico. Before 1996, when Bollgard cotton expressing the Cry1A(c) delta-endotoxin was introduced into the region, two important patterns were documented. The first was economically significant increases in resistance to certain insecticide groups. The second was occurrence of virtually complete control failures in the field during 1994 and 1995. The largest resistance changes were recorded for the type II pyrethroids cypermethrin and deltamethrin. These products are the most widely used products in the region. Resistance ratios for these products increased up to > 100-fold from 1991 to 1995. After 1996, the resistance levels declined. These findings did not occur with other products of scant use (e.g., permethrin, profenofos, and endosulfan) or low tobacco budworm efficacy coupled to a high use pattern (e.g., methyl parathion). This clear trend toward reversal of resistance to type II pyrethroids can be understood, in part, with respect to two factors: 1) the high adoption rate of transgenic cotton in the region, from 31.2% in the beginning (1996) to approximately 90% in 1998; this has considerably curbed the use of synthetic insecticides, with the attending loss of selection pressure on this pest; and 2) the potential immigration to the region of susceptible tobacco budworms from cultivated and wild suitable hosts as well as from transgenic cotton might have influenced the pest population as a whole. The influence of transgenic cotton on southern Tamaulipas can be more clearly seen by the drastic reduction of insecticide use to control this important pest. Now tobacco budworms in this region are susceptible to type II pyrethroids. Two effective and fundamentally different pest management tools are now available to cotton growers in southern Tamaulipas: transgenic cotton

  1. Phylogenetic relationships of leopard frogs (Rana pipiens complex) from an isolated coastal mountain range in southern Sonora, Mexico.

    PubMed

    Pfeiler, E; Markow, T A

    2008-10-01

    Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup, or Scurrilirana clade, of the R. pipiens group, and are most closely related to Rana magnaocularis from Nayarit, Mexico. We also provide further evidence that Rana magnaocularis and R. yavapaiensis are close relatives. PMID:18625327

  2. Is It Working? Lysimeter Monitoring in the Southern Willamette Valley Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  3. Gravity and Magnetic Survey of the Oaxaca-Juarez Terrane Boundary (Oaxaca Fault), Southern Mexico: Evidence for three Half Grabens

    NASA Astrophysics Data System (ADS)

    Campos-Enriquez, J. O.; Belmonte-Jimenez, S. I.; Ortega-Gutierrez, F.; Keppie-Moorhouse, J. D.; Martinez-Silva, J.; Martinez-Serrano, R.

    2007-05-01

    A geophysical survey of the Oaxaca Fault boundary between the Oaxaca (Oaxaquia) (Zapoteco) and Juarez (Cuicateco) terranes along the Etla and Zaachila valleys area, southern Mexico shows a series of NW-SE Bouguer and magnetic anomalies with stronger gradients towards the east. The basement from the Oaxaca terrane has a high density (2.8 gr/cm3 ) and magnetic susceptibility of up to 0.0051 cgs units, which contrast with the Juarez basement that has a lower density (2.67 gr/cm3) and a higher magnetic susceptibility (values ranging between 0.0025 to 0.0045 cgs units). The magnetic susceptibility is similar south of the Donaji fault. Interpretation of six combined gravity and magnetic NE-SW profiles perpendicular to the valleys indicates the presence of a composite depression comprising three N-S sub-basins with the Etla and Zachila sub-basins located at the northern and southern portions, respectively, separated by a third sub-basin relatively displaced westwards. They are bounded on the east by the steeply W-dipping Oaxaca master fault, and on the west by the gently E-dipping Huitzo-Zimatlan fault. Two interpretations are suggested for the southward continuation of the Oaxaca Fault: 1) it continues southwards at depth with the same strike. Together the Bouguer and total field magnetic anomalies suggest that the Oaxaca fault is continuous from Etla via Oaxaca City and Ocotlán de Morelos probably to Miahuatlán de Porfirio Díaz, and 2) it continues with the same strike but is displaced eastwards ~20 km along a sinistral transfer fault, which forms the northern boundary of the Zaachila sub-basin.

  4. 33 CFR 334.720 - Gulf of Mexico, south from Choctawhatchee Bay; guided missiles test operations area, Headquarters...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Gulf of Mexico, south from... Mexico, south from Choctawhatchee Bay; guided missiles test operations area, Headquarters Air Proving... Mexico south from Choctawhatchee Bay within an area described as follows: Beginning at a point...

  5. 33 CFR 334.720 - Gulf of Mexico, south from Choctawhatchee Bay; guided missiles test operations area, Headquarters...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico, south from... Mexico, south from Choctawhatchee Bay; guided missiles test operations area, Headquarters Air Proving... Mexico south from Choctawhatchee Bay within an area described as follows: Beginning at a point...

  6. Utilizing NASA Earth Observations to detect factors contributing to hypoxic events in the southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Chapman, R.; Johansen, A.; Mitchell, Å. R.; Caraballo Álvarez, I. O.; Taggart, M.; Smith, B.

    2015-12-01

    Monitoring and analyzing harmful algal blooms (HABs) and hypoxic events in the southern coastal areas of the Gulf of Mexico (GoM) is important for watershed management and mitigation of environmental degradation. This study uncovered trends and dynamic characteristics of chlorophyll-a (Chl) concentration, sea surface temperature (SST), colored dissolved organic matter index (CDOM), and photosynthetically available radiation (PAR); as evident in 8-day standard mapped image (SMI) products from the MODIS instrument on the Aqua platform from 2002-2015 using Clark Labs TerrSet Earth Trends Modeler (ETM). Predicted dissolved oxygen images were classified using a Multi-Layer Perceptron regression approach with in-situ data from the northern GoM. Additionally, sediment and nutrient loading values of the Grijalva-Usumacinta watershed were modeled using the ArcGIS Soil and Water Assessment Tool (SWAT). Lastly, A Turbidity Index was generated using Landsat 8 Operational Land Imager (OLI) scenes for 2014-2015. Results, tools, and products will assist local environmental and health authorities in revising water quality standards and mitigating the impacts of future HABs and hypoxic events in the region. This project uses NASA's earth observations as a viable alternative to studying a region with no in-situ data.

  7. ETHNICITY AND INCOME IMPACT ON BMI AND STATURE OF SCHOOL CHILDREN LIVING IN URBAN SOUTHERN MEXICO.

    PubMed

    Mendez, Nina; Barrera-Pérez, The Late Mario; Palma-Solis, Marco; Zavala-Castro, Jorge; Dickinson, Federico; Azcorra, Hugo; Prelip, Michael

    2016-03-01

    Obesity affects quality of life and increases the risk of morbidity and mortality. Mexico, a middle-income country, has a high prevalence of overweight and obesity among urban children. Merida is the most populated and growing city in southern Mexico with a mixed Mayan and non-Maya population. Local urbanization and access to industrialized foods have impacted the eating habits and physical activity of children, increasing the risk of overweight and obesity. This study aimed to contribute to the existing literature on the global prevalence of overweight and obesity and examined the association of parental income, ethnicity and nutritional status with body mass index (BMI) and height in primary school children in Merida. The heights and weights of 3243 children aged 6-12 from sixteen randomly selected schools in the city were collected between April and December 2012. Multinomial logistic regression models were used to examine differences in the prevalence of BMI and height categories (based on WHO reference values) by ethnicity and income levels. Of the total students, 1648 (50.9%) were overweight or obese. Stunting was found in 227 children (7%), while 755 (23.3%) were defined as having short stature. Combined stunting and overweight/obesity was found in 301 students (9.3%) and twelve (0.4%) were classified as stunted and of low weight. Having two Mayan surnames was inversely associated with having adequate height (OR=0.69, p<0.05) and the presence of two Maya surnames in children increased the odds of short stature and stunting. Children from lower income families had twice the odds of being stunted and obese. Overweight, obesity and short stature were frequent among the studied children. A significant proportion of Meridan children could face an increased risk of developing cardiovascular disease and its associated negative economic and social outcomes unless healthier habits are adopted. Action is needed to reduce the prevalence of obesity among southern

  8. Organochlorine pesticides in soils and air of southern Mexico: Chemical profiles and potential for soil emissions

    NASA Astrophysics Data System (ADS)

    Wong, Fiona; Alegria, Henry A.; Jantunen, Liisa M.; Bidleman, Terry F.; Salvador-Figueroa, Miguel; Gold-Bouchot, Gerardo; Ceja-Moreno, Victor; Waliszewski, Stefan M.; Infanzon, Raul

    The extent of organochlorine pesticides (OCs) contamination in southern Mexico was investigated in this study. Biweekly air samplings were carried out in two sites in the state of Chiapas (during 2002-2003), and one in each state of Veracruz and Tabasco (during 2003-2004). Corresponding to the air sampling locations, soil samples were also collected to gauge the soil-air exchange of OCs in the region. ∑DDTs in soils ranged from 0.057 to 360 ng g -1 whereas those in air ranged from 240 to 2400 pg m -3. DDT and metabolite DDE were expressed as fractional values, FDDTe = p, p'-DDT/( p, p'-DDT + p, p'-DDE) and FDDTo = p,p'-DDT/( p,p'-DDT + o,p'-DDT). FDDTe in soils ranged from 0.30 to 0.69 while those in air ranged from 0.45 to 0.84. FDDTe in air at a farm in Chiapas (0.84) was closer to that of technical DDT (0.95) which is suggestive of fresh DDT input. Enantiomer fractions (EF) of o,p'-DDT in air were racemic at all locations (0.500-0.504). However, nonracemic o,p'-DDT was seen in the soils (EFs = 0.456-0.647). Fugacities of OCs in soil ( fs) and air ( fa) were calculated, and the fugacity fraction, ff = fs/( fs + fa) of DDTs ranged from 0.013 to 0.97 which indicated a mix of net deposition ( ff < 0.5) and volatilization ( ff > 0.5) from soil among the sites. It is suggested that DDTs in Mexico air are due to a combination of ongoing regional usage and re-emission of old DDT residues from soils. Total toxaphene in soils ranged from 0.066 to 69 ng g -1 while levels in air ranged from 6.2 to 230 pg m -3. Chromatographic profiles of toxaphenes in both air and soil showed depletion of Parlar congeners 39 and 42. Fugacity fractions of toxaphene were within the equilibrium range or above the upper equilibrium threshold boundary. These findings suggested that soil emission of old residues is the main source of toxaphenes to the atmosphere. Results from this study provide baseline data for establishing a long-term OC monitoring program in Mexico.

  9. SPLASH: A Southern Parkes Large Area Survey in Hydroxyl

    NASA Astrophysics Data System (ADS)

    Dawson, Joanne; Caswell, James; Gomez, Jose F.; Mcclure-Griffiths, Naomi; Lo, Nadia; Jones, Paul; Dickey, John; Cunningham, Maria; Green, James; Carretti, Ettore; Ellingsen, Simon; Walsh, Andrew; Purcell, Cormac; Breen, Shari; Hennebelle, Patrick; Imai, Hiroshi; Lowe, Vicki; Gibson, Steven; Brown, Courtney; Krishnan, Vasaant

    2014-04-01

    The OH 18 cm lines are powerful and versatile probes of diffuse molecular gas, that trace a largely unstudied component of the Galactic ISM. SPLASH (the Southern Parkes Large Area Survey in Hydroxyl) is a large, unbiased and fully-sampled survey of OH emission, absorption and masers in the Galactic Plane that will achieve sensitivities an order of magnitude better than previous work. The survey is answering critical questions on the global distribution of diffuse OH, the degree to which it traces ‘hidden’ material caught between the regimes probed by traditional tracers of the neutral ISM, and its role as a probe of molecular cloud formation. As a blind survey for all four ground-state transitions, SPLASH is also detecting many new OH masers, facilitating a broad range of astrophysical studies. This proposal requests 250 hours to complete Phase 1 of the SPLASH project, which is mapping 152 square degrees in the inner Galactic Plane, including the Galactic Centre.

  10. Spinosad: a biorational mosquito larvicide for use in car tires in southern Mexico

    PubMed Central

    2012-01-01

    Background Car tires are important habitats for mosquito development because of the high density populations they can harbor and their presence in urban settings. Water in experimental tires was treated with one of three insecticides or an untreated control. Aquatic invertebrates were sampled at weekly intervals. Eggs, larval and pupal samples were laboratory-reared to estimate seasonal fluctuations in Aedes aegypti and Ae. albopictus abundance. Results Spinosad treatments at 1 or 5 ppm (mg a.i./liter) provided 6–8 weeks of effective control of Ae. aegypti, Ae. albopictus, Culex quinquefasiatus and Cx. coronator larvae, both in the dry season and the rainy season when mosquito populations increased markedly in southern Mexico. Spinosad continued to provide partial control of larvae for several weeks after initial recolonization of treated tires. The larvicidal performance of VectoBac 12AS (Bacillus thuringiensis var. israelensis) was relatively poor with one week of complete control of Aedes spp. larvae and no discernible control of Culex spp., whereas the duration of larvicidal activity of 1% temephos mineral-based granules was intermediate between those of VectoBac and spinosad treatments. Populations of chironomids, ostracods and Toxorhynchites theobaldi were generally reduced in spinosad and temephos treatments, but were similar in control and VectoBac treatments. Conclusion The present study is the first to report spinosad as an effective larvicide against Cx. coronator, which is currently invading the southern United States. These results substantiate the use of spinosad as a highly effective mosquito larvicide, even in habitats such as unused car tires that can represent prolific sources of adult mosquitoes. PMID:22608138

  11. Availability of ground water in the Gallup area, New Mexico

    USGS Publications Warehouse

    West, Samuel Wilson

    1961-01-01

    -bearing properties of the Westwater Canyon member and the Dakota sandstone are ill defined, because few wells in the area tap either of them exclusively. The specific capacity of wells that tap the Westwater Canyon member, the Dakota sandstone, or both ranges from 0.02 to 2.3 gpm per foot of drawdown. Water in this aquifer generally contains less that 1,000 ppm (parts per million) of dissolved solids. The concentration of sodium and bicarbonate typically is high, and the concentration of sulfate is high locally. The Gallup sandstone is the principal aquifer in the immediate vicinity of, and to the north and south of, Gallup. It yields as much as 260 gpm of water to wells; the specific capacity of wells that tap the Gallup sandstone ranges from 0.08 to 4.7 gpm per foot of drawdown. In general, the water in the Gal]up sandstone is potable, although in places it yields water high in iron, sulfate, and dissolved solids; the concentration of dissolved solids generally is less than 1,000 ppm. Because the yields of all the formations tested at Gallup are small, the town needs a better source of water. The San Juan River discharges annually a larger volume of water than is available from any other source in northwestern New Mexico. Gallup has applied for 15,000 acre-feet of San Juan River water a year, an average of 13,400,000 gpd (gallons per day). This water would be expensive, because about 50 miles of pipeline would be required to transport the water, and it would have to be liked about 1,000 feet over a high ridge north of town. Despite the expense involved, at this time the San Juan River seems to offer the most secure long-term supply of water for the Gallup area.

  12. The 29 July 2014 (Mw 6.4) Southern Veracruz, Mexico Earthquake: Scenary Previous to Its Occurrence.

    NASA Astrophysics Data System (ADS)

    Yamamoto, J.

    2014-12-01

    On 29 July 2014 (10:46 UTC) a magnitude 6.4 (Mw) earthquake occurred at the southern Veracruz, Mexico region. The epicenter was preliminary located at 17.70° N and 95.63° W. It was a normal fault event with the slip on a fault that trend NNW and a focus approximately 117 km below the surface of the Gulf of Mexico costal plane. The earthquake was widely felt through centro and southern Mexico. In Oaxaca City 133 km to the south a person die of a hearth attack. No damages were reported. Most prominent moderate-sized earthquakes occurring in the southern Veracruz region since 1959 has been concentrated along two well defined seismic belts. One belt runs off the coast following nearly its contour. Here the earthquakes are shallow depth and mostly show a reverse fault mechanism. This belt of seismicity begins at the Los Tuxtlas volcanic field. Another seismic belt is located inland 70 km to the west. Here most earthquakes are of intermediate-depth (108-154 km) focus and normal faulting mechanism. The July 2014 earthquake is located near to this second seismic belt. In the present paper we discuss, within the regional geotectonic framework, the location and some aspects of the rupture process of the July 2014 earthquake.

  13. Geodetic surveys across the Messina Straits (southern Italy) seismogenetic area

    NASA Astrophysics Data System (ADS)

    Anzidei, M.; Baldi, P.; Bonini, C.; Casula, G.; Gandolfi, S.; Riguzzi, F.

    1998-01-01

    The Messina Straits, southern Italy, unfortunately became famous after the occurrence of the great earthquake of December 28, 1908, Ms = 7.5, that caused thousands of deaths and severe destruction over a wide area along the Sicilian and Calabrian coasts. After that time many geophysical and geological studies were performed to evaluate the seismic characteristics of the 1908 earthquake, the seismic risk and the geological evolution of this region in the framework of Mediterranean geodynamics. In 1970, a geodetic network was set up across the Straits and was repeatedly measured with terrestrial techniques until 1980, showing a northward displacement of the Sicilian sites with respect to the Calabrian ones, between 1970 and 1971. In 1987, the old terrestrial network was surveyed again for the first time by the GPS technique, improving the accuracy of the coordinate determinations. Finally, in 1994, a wider network was established and surveyed again to collect additional GPS observations from a larger area across the Straits. In this paper, an analysis of the results obtained from the two GPS surveys with respect to those achieved by the terrestrial surveys (from 1970 to 1980) is given. This analysis shows there has not been significant crustal horizontal deformation across the Straits in the last 15 years. Although this crustal tectonic 'quiescence' corresponds to a low seismic activity level in the Straits area, terrestrial and GPS geodetic results would agree with Straits geophysical models excluding any aseismic deformations acting perpendicular to the Straits axis.

  14. Large-area dry bean yield prediction modeling in Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Given the importance of dry bean in Mexico, crop yield predictions before harvest are valuable for authorities of the agricultural sector, in order to define support for producers. The aim of this study was to develop an empirical model to estimate the yield of dry bean at the regional level prior t...

  15. Cross-shelf and vertical structure of ichthyoplankton assemblages in continental shelf waters of the Southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Espinosa-Fuentes, M. L.; Flores-Coto, C.

    2004-02-01

    The horizontal and vertical variation of ichthyoplankton assemblages in continental shelf waters of the Southern Gulf of Mexico was studied during an annual cycle (1994-1995) at 22 stations distributed across four transects located off the main fluvio-lagoon systems of the area. Samples were collected from five levels of the water column, from the surface to a depth of 105 m. The Bray-Curtis Dissimilarity Index identified five assemblages: Coastal, Inner Neritic, Outer Neritic, Oceanic and a Transition Group. The main species of each assemblage reflected the habitat, season, and spawning area of adult organisms. The Coastal Assemblage occupied the uppermost water column levels of the most nearshore stations. The Oceanic Assemblage was restricted to the deepest samplings of the stations of the outer shelf and the Neritic Assemblages were located on the continental shelf between the Coastal and Oceanic Assemblages, embracing all the sampling levels in some periods. Variation in composition, location and abundance of larvae in each assemblage was determined by a series of physical processes that act at different temporal and spatial scales, especially the mixing process generated by the wind stress and continental water discharges acting at a mesoscale that influences the distribution of the assemblages along the whole continental shelf as well as a fine scale affecting the composition and vertical distribution of organisms in a more reduced area of just tens of meters in the water column. Canonical Correspondence Analysis revealed that the depth of the sample, the potential energy, and the temperature generated the greatest variability in the system. Vertical and horizontal salinity gradients play a determinant role in delimiting the Coastal and Neritic Assemblages.

  16. Acquired transmission-blocking immunity to Plasmodium vivax in a population of southern coastal Mexico.

    PubMed

    Ramsey, J M; Salinas, E; Rodríguez, M H

    1996-05-01

    Naturally acquired transmission-blocking immunity to Plasmodium vivax was studied in three groups of patients from the southern coast of Mexico: primary cases (Group A, 61% of the study population), secondary cases with the prior infection seven or more months earlier (Group B, 23%), and secondary cases with the previous malaria experience within six months of the present study (Group C, 16%). Anopheles albimanus mosquitoes were fed with patients' infected blood cells in the presence of autologous or control serum, with or without heat-inactivation. Patients from all three groups had transmission-blocking immunity, although the quality and quantity of this blocking activity was significantly higher in the two secondary patient groups (B and C). Only primary malaria cases produced transmission-enhancing activity (23% of the cases), which was dependent on heat-labile serum components. The levels of patient group transmission-blocking immunity and mosquito infectivity were used to calculate the probabilities of a mosquito becoming infective after taking a blood meal from a P. vivax-infected patient from any one of the three groups. This probability was 0.025, with Group A patients providing the major source of these infections (92% risk from Group A and 4% risk for Groups B and C). PMID:8644898

  17. Intradomicillary pre- and postfeeding behavior of Anopheles pseudopunctipennis of southern Mexico: implications for malaria control.

    PubMed

    Casas, M; Bown, D N; Rodríguez, M H

    1994-09-01

    The intradomicillary pre- and postfeed resting behavior of Anopheles pseudopunctipennis was studied in an experimental house in southern Mexico. During resting periods (both pre-/postfeed) mosquitos had greater contact (landings) with the inner roof than with the walls and other surfaces. A comparison of mean landing frequency and overall resting time (pre-/postfeed) showed that a greater periodic and prolonged contact occurred prefeed, probably as a result of disturbed activity associated with host movements. Pre-/postfeed resting patterns on walls were limited to a 0.6-0.5-m-wide band, nearly 1 m from the floor, and to a narrower band on the roof, 0.3-0.2 m wide, approximately 2.3 m from the floor, respectively. We calculated that with a band width of 0.8 m on the walls and another band 0.8 m wide on the roof, 87.2% of the mosquitoes had at least one contact with either the wall, the roof, or with both surfaces, along with an overall mean resting time (pre-/postfeed) of 8.1 min/landing. These findings suggest that a high potential for control can be achieved by spraying preferred wall and roof resting sites in this region where the intradomicillary application of residual insecticide is the primary malaria control measure. PMID:7807076

  18. Gonotrophic cycle and survivorship of Anopheles pseudopunctipennis (Diptera: Culicidae) in the Tapachula foothills of southern Mexico.

    PubMed

    Fernandez-Salas, I; Rodriguez, M H; Roberts, D R

    1994-05-01

    Mark-release-recapture experiments were conducted to determine the length of the gonotrophic cycle and survivorship of Anopheles pseudopunctipennis Theobald in the Tapachula foothills of southern Mexico. Separate trials with wild-caught females were conducted in the early and late dry season to examine intraseasonal differences. The gonotrophic cycle of insectary-reared, nulliparous females was estimated during the late dry season. A total of 5.4-5.7% of marked females was recaptured. A 3-d gonotrophic cycle was characteristic of wild-caught females, whereas a 4-d gonotrophic cycle was characteristic for insectary-reared females. Engorged, wild-caught females completed oogenesis in approximately 60 h under field conditions. Blood digestion in 23.5% of 2,221 and 21.9% of 1,195 engorged, wild-caught females held in the insectary was not accompanied by egg development. Dissections of these females showed that nearly 85% were nulliparous and presumably pregravid. These statistics plus other field data were used to determine that 60% of all nulliparous entered a pregravid condition. The body size and wing length of gravids was significantly larger than pregravids. Daily survival estimates of 0.875 and 0.884 were calculated for field-collected females during the early and late dry season, respectively. PMID:8057307

  19. The acoustic repertoire of bottlenose dolphins (Tursiops truncatus) from the southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Bazua-Duran, Carmen

    2005-04-01

    Bottlenose dolphins live in a variety of habitats of the world's oceans using their acoustic repertoire to communicate and inspect their environment. This work investigates the acoustic repertoire of bottlenose dolphins that inhabit a coastal lagoon of the southern Gulf of Mexico, the Laguna de Terminos and how it may relate to the dolphins' general behavioral state and herd size, and to the general characteristics of the habitat, such as visibility, depth, and sea state. Preliminary results show that bottlenose dolphins produce by far more clicks than whistles in all behavioral states (feeding, resting, social, and travel) and herd sizes, which may correlate with the decreased visibility and shallow depth of the Laguna de Terminos. Additionally, silence was found during all behavioral states, but very seldom in herds of large size. These preliminary results suggest that bottlenose dolphins are choosing when and where to produce their phonations. Therefore, more detailed studies are needed to understand how these animals are using their acoustic sense to communicate and inspect their environment. [Work supported by CONACyT-Gobierno Edo. de Campeche and PAPIIT, UNAM.

  20. Cyanobacteria associated with Anopheles albimanus (Diptera: Culicidae) larval habitats in southern Mexico.

    PubMed

    Vázquez-Martínez, M Guadalupe; Rodríguez, Mario H; Arredondo-Jiménez, Juan I; Méndez-Sanchez, José D; Bond-Compeán, J Guillermo; Cold-Morgan, Michelle

    2002-11-01

    Cyanobacteria associated with Anopheles albimanus Wiedemann larval habitats from southern Chiapas, Mexico, were isolated and identified from water samples and larval midguts using selective medium BG-11. Larval breeding sites were classified according to their hydrology and dominant vegetation. Cyanobacteria isolated in water samples were recorded and analyzed according to hydrological and vegetation habitat breeding types, and mosquito larval abundance. In total, 19 cyanobacteria species were isolated from water samples. Overall, the most frequently isolated cyanobacterial taxa were Phormidium sp., Oscillatoria sp., Aphanocapsa cf. littoralis, Lyngbya lutea, P. animalis, and Anabaena cf. spiroides. Cyanobacteria were especially abundant in estuaries, irrigation canals, river margins and mangrove lagoons, and more cyanobacteria were isolated from Brachiaria mutica, Ceratophyllum demersum, and Hymenachne amplexicaulis habitats. Cyanobacteria were found in habitats with low to high An. albimanus larval abundance, but Aphanocapsa cf. littoralis was associated with habitats of low larval abundance. No correlation was found between water chemistry parameters and the presence of cyanobacteria, however, water temperature (29.2-29.4 degrees C) and phosphate concentration (79.8-136.5 ppb) were associated with medium and high mosquito larvae abundance. In An. albimanus larval midguts, only six species of cyanobacteria were isolated, the majority being from the most abundant cyanobacteria in water samples. PMID:12495179

  1. Maize diversity associated with social origin and environmental variation in Southern Mexico.

    PubMed

    Orozco-Ramírez, Q; Ross-Ibarra, J; Santacruz-Varela, A; Brush, S

    2016-05-01

    While prevailing theories of crop evolution suggest that crop diversity and cultural diversity should be linked, empirical evidence for such a link remains inconclusive. In particular, few studies have investigated such patterns on a local scale. Here, we address this issue by examining the determinants of maize diversity in a local region of high cultural and biological richness in Southern Mexico. We collected maize samples from villages at low and middle elevations in two adjacent municipalities of differing ethnicity: Mixtec or Chatino. Although morphological traits show few patterns of population structure, we see clear genetic differentiation among villages, with municipality explaining a larger proportion of the differentiation than altitude. Consistent with an important role of social origin in patterning seed exchange, metapopulation model-based estimates of differentiation match the genetic data within village and ethnically distinct municipalities, but underestimate differentiation when all four villages are taken together. Our research provides insights about the importance of social origin in structuring maize diversity at the local scale. PMID:26905463

  2. Localized seismic anisotropy associated with long-term slow-slip events beneath southern Mexico

    NASA Astrophysics Data System (ADS)

    Song, Teh-Ru Alex; Kim, YoungHee

    2012-05-01

    Slow slip events (SSEs) are recently discovered in the transition zone downdip of the locked zone where megathrust earthquakes repeatedly occur at subduction zone interface. Structural changes from the locked zone to the transition zone and the nature of in situ deformation in the transition zone, however, remain unclear. We model teleseismic converted P-to-S waves to investigate seismic structural transition and anisotropy associated with shear deformation near the deep locked zone and the transition zone beneath southern Mexico. The deep locked zone appears to be consistent with normal oceanic crust velocity. In the transition zone, we find that seismic anisotropy larger than 5% is associated with the ultra-slow velocity layer (USL) near the top of the subducted oceanic crust. The foliation plane is plunging 20 ± 10 degrees steeper than the plate interface, and it is consistent with crystallographic preferred orientation developed in S-C mylonites. We suggest that long-term SSEs likely coincide with a near-lithostatic semiductile talc-rich shear zone.

  3. Differentiation and concordance in smallholder land use strategies in southern Mexico's conservation frontier

    PubMed Central

    Roy Chowdhury, Rinku

    2010-01-01

    Forest cover transitions in the developing tropics are conditioned by agricultural change. The expansion, intensification, and diversification of agricultural land uses are tied to regional economic/environmental regimes and decisions of local farming households. Land change science and agrarian systems research share an interest in the drivers of household strategies, land use impacts, and typologies of those land uses/drivers. This study derives a typology of farming households in southern Mexico based on emergent patterns in their land use combinations and analyzes their household and policy drivers. The results reveal broadly diversified household land use portfolios as well as three emergent clusters of farmstead production orientation: (i) extensive subsistence-oriented conservationists, (ii), dual extensive-intensive farmers, and (iii) nonextensive diversified land users. Household membership in these clusters is uneven and strongly related to tenancy, land endowments, wage labor, and policy subsidies. Although most households are following a nonextensive agricultural strategy incorporating off-farm incomes, the likelihood of a regional forest transition remains debatable because of the disproportionate deforestation impacts of the less common strategies. Conservation development policies in the region need to accommodate diverse smallholder farming rationales, increase off-farm opportunities, and target sustainable development with the assistance of community conservation leaders. PMID:20339082

  4. IMPACT OF CIGARETTE SMOKING ON RATES AND CLINICAL PROGNOSIS OF PULMONARY TUBERCULOSIS IN SOUTHERN MEXICO

    PubMed Central

    Bonacci, Robert A.; Cruz-Hervert, Luis Pablo; García-García, Lourdes; Reynales-Shigematsu, Luz Myriam; Ferreyra-Reyes, Leticia; Bobadilla-del-Valle, Miriam; Canizales-Quintero, Sergio; Ferreira-Guerrero, Elizabeth; Báez-Saldaña, Renata; Téllez-Vázquez, Norma; Mongua-Rodríguez, Norma; Montero-Campos, Rogelio; Delgado-Sánchez, Guadalupe; Martínez-Gamboa, Rosa Areli; Cano-Arellano, Bulmaro; Sifuentes-Osornio, José; de León, Alfredo Ponce

    2012-01-01

    Objectives To examine the relationship between cigarette smoking and incidence and mortality rates of pulmonary tuberculosis (TB) and treatment outcomes. Materials From 1995-2010, we analyzed data from 1062 patients with TB and from 2001-2004, 2951 contacts in Southern Mexico. Patients with acid-fast bacilli or Mycobacterium tuberculosis in sputum samples underwent epidemiological, clinical and mycobacteriological evaluation and received treatment by the local DOTS program. Results Consumers of 1-10 (LS) or 11 or more (HS) cigarettes per day incidence (1.75 and 11.79) and mortality (HS,17.74) smoker-nonsmoker rate ratios were significantly higher for smokers. Smoker population was more likely to experience unfavorable treatment outcomes (HS, adjusted OR 2.36) and retreatment (LS and HS, adjusted hazard ratio (HR) 2.14 and 2.37). Contacts that smoked had a higher probability of developing active TB (HR 2.38) during follow up. Conclusions Results indicate the need of incorporating smoking prevention and cessation, especially among men, into international TB control strategies. PMID:22982014

  5. Adakitic-like volcanism in Southern Mexico and subduction of the Tehuantepec Ridge

    NASA Astrophysics Data System (ADS)

    Manea, M.; Manea, V. C.

    2007-05-01

    The origin of El Chichón volcano is poorly understood, and our attempt in this study is to demonstrate that Tehuantepec Ridge, a major tectonic discontinuity on the Cocos plate, plays a key role in the slab dehydration budget and therefore in partial melting of the mantle beneath El Chichón. Using marine magnetic anomalies we show that the upper mantle beneath TR undergo partial serpentinization, a 5-7 km thick serpentinized root extending along TR and below the oceanic crust. Another key aspect of the magnetic anomaly over southern México is a long-wavelength (~150 km) high amplitude (~500 nT) magnetic anomaly located between the trench and the coast. Using a 2D joint magnetic-gravity forward model, constrained by the subduction P-T structure, slab geometry and seismicity, we find a highly magnetic and low-density source located at 40-130 km depth. We interpret this result as a serpentinized mantle wedge by fluids expelled from the subducting Cocos plate beneath southern Mexico. Such a deep hydrated mantle requires a low temperature wedge (T<600° C) because serpentine is stable below this temperature and also the magnetic properties are preserved for temperature less than the Currie point for magnetite (~580° C). This result explains the lack of volcanism in southern México where the slab depth is ~ 100 km. Using phase diagrams for sediments, basalt and peridotite, and the subduction P-T structure beneath El Chichón we find that sediments and basalt dehydrate ~ 50% at depths corresponding with the location of serpentinized mantle wedge, whereas the serpentinized root beneath TR strongly dehydrates (60-80%) at higher depths (170-180 km) comparable with the slab depth beneath El Chichón. We conclude that this strong deserpentinization pulse of mantle lithosphere beneath TR at great depths triggers arc melting, explaining the unusual location and probably the adakitic signature of El Chichón.

  6. Identification of sensitive parameters of a tropical forest in Southern Mexico to improve the understanding of C-band radar images

    NASA Astrophysics Data System (ADS)

    Monsivais-Huertero, A.; Jimenez-Escalona, J. C.; Ramos, J.; Zempoaltecatl-Ramirez, E.

    2013-05-01

    Forest areas cover the 32% of the Mexican territory. Due to their geographical location, Mexico presents heterogeneous climatic and topographic conditions. The country is divided into two different regions: an arid /semiarid zone (North) and a tropical/temperate zone (South). Due to the effects of climate change, Mexico has been affected in two ways. In the North, there has been a desertification of regions as result of the absence of rainfall and a low rate of soil moisture. On the other hand, in the South, there has been an increase in the intensity of rainfall causing serious flooding. Another effect is the excessive deforestation in Southern Mexico. The FAO has determined that Mexico could present one of the highest losses of forest areas mainly in temperate and subtropical ecosystems. The Biosphere Reserve of Calakmul is the protected area with the largest surface of tropical forest in Mexico. The Biosphere Reserve of Calakmul is located in the state of Campeche that the flora and fauna are being affected. The type of vegetation located in the reserve of Calakmul Biosphere is rainforest with high spatial density and highly heterogeneous due to multiple plant species and the impact of human activities in the area. The satellite remote sensing techniques becomes a very useful tool to monitor the area because a large area can be covered. To understand the radar images, the identification of sensitive parameters governing the radar signal is necessary. With the launch of the satellites Radarsat-2, ASAR-Envisat and ALOSPalSAR, significant progress has been done in the interpretation of satellite radar images. Directly applying physical models becomes a problem due to the large number of input parameters in the models, together with the difficulty in measuring these parameters in the field. The models developed so far have been applied and validated for homogeneous forests with low or average spatial density of trees. This is why it is recommended in a comprehensive

  7. Net Exchange Ecossistem in Subtropical Agriculture Area in Southern Brazil

    NASA Astrophysics Data System (ADS)

    Roberti, D. R.; Diaz, M.; Webler, G.; Fiorin, J.; de Moraes, O. L. L.; Teichrieb, C.; Amado, T.

    2015-12-01

    Southern Brazil contribute to 38% of Brazilian grain production. In contrast with the rest of the country, the south has a wet, subtropical climate that permits two annual harvests (double cropping system). The soybean and/or maize (summer) and black oat and/or wheat (winter) succession is widely used by farmers in plateau areas. In river natural lowlands, the cultivation of flooded irrigated rice is common. Changes in the land use affect the carbon, water and energy balance, and crop management practices, such as fertilization, water management, harvest and crop residues have influence in carbon exchange between the crop field and the atmosphere. This study quantifies the net exchange ecosystem (NEE) between the atmosphere and the crop cultivations in this wide region of Brazil from 2010 to 2014. We use data from two micrometeorological sites: Cruz Alta, with crop rotation and Cachoeira do Sul, with rice paddy. The carbon flux was analyzed using the eddy covariance method and gap filling procedures. The annual integration of data carbon demonstrates that the agroecosystems in southern Brazil is a acting as an light atmospheric CO2 sink. However, the NEE emissions that occurred in the fallow periods contributed negatively for such annual accumulation. To reduce this loss of CO2, farmers could cultivate plants in fallow periods, because there are favorable weather conditions for growing plants year round. Additionally, other management practices can increase the influx of C, including the production of more dry matter with cover crops by improving management and the immediate harvesting of crop after physiological maturity to reduce the period between maturation and harvest.

  8. 33 CFR 334.763 - Naval Support Activity Panama City; Gulf of Mexico; restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Naval Support Activity Panama....763 Naval Support Activity Panama City; Gulf of Mexico; restricted area. (a) The area. The area is... enforced by the Commanding Officer, Naval Support Activity, Panama City Florida, and such agencies as...

  9. SEDIMENT HAZARD ASSESSMENT FOR NEAR-COASTAL AREAS OF THE GULF OF MEXICO

    EPA Science Inventory

    Sediment contamination is a major problem in many coastal areas in the U.S. and has emerged as an important ecological issue for several geographic areas. Sediment chemical and biological quality is unknown in many areas of the Gulf of Mexico. To provide some information on this ...

  10. Potentiometric surfaces, summer 2013 and winter 2015, and select hydrographs for the Southern High Plains aquifer, Cannon Air Force Base, Curry County, New Mexico

    USGS Publications Warehouse

    Collison, Jake

    2016-01-01

    Cannon Air Force Base (Cannon AFB) is located in the High Plains physiographic region of east-central New Mexico, about 5 miles west of Clovis, New Mexico. The area surrounding Cannon AFB is primarily used for agriculture, including irrigated cropland and dairies. The Southern High Plains aquifer is the principal source of water for Cannon AFB, for the nearby town of Clovis, and for local agriculture and dairies. The Southern High Plains aquifer in the vicinity of Cannon AFB consists of three subsurface geological formations: the Chinle Formation of Triassic age, the Ogallala Formation of Tertiary age, and the Blackwater Draw Formation of Quaternary age. The Ogallala Formation is the main water-yielding formation of the Southern High Plains aquifer. Groundwater-supplied, center-pivot irrigation dominates pumping from the Southern High Plains aquifer in the area surrounding Cannon AFB, where the irrigation season typically extends from early March through October. The U.S. Geological Survey has been monitoring groundwater levels in the vicinity of Cannon AFB since 1954 and has developed general potentiometric-surface maps that show groundwater flow from northwest to southeast in the study area. While previous potentiometric-surface maps show the general direction of groundwater flow, a denser well network is needed to show details of groundwater flow at a local scale. Groundwater levels were measured in 93 wells during summer 2013 and 100 wells during winter 2015.The summer and winter potentiometric-surface maps display the presence of what is interpreted to be a groundwater trough trending from the northwest to the southeast through the study area. This groundwater trough may be the hydraulic expression of a Tertiary-age paleochannel. Groundwater north of the trough flows in a southerly direction into the trough, and groundwater south of the trough flows in an easterly direction into the trough.During the 18-month period between summer 2013 and winter 2015, changes

  11. Wisconsinan-Holocene seismic stratigraphy of the Keathley Canyon Area and vicinity, northwestern Gulf of Mexico

    SciTech Connect

    Lee, Gwang Hoon; Bryant, W.R.; Watkins, J.S. )

    1991-03-01

    The lower continental slope of the northwestern Gulf of Mexico is characterized by a hummocky topography with shallow salt masses interspersed by numerous salt-withdrawal basins containing thick Plio-Pleistocene and older sediments. Analysis of over 7500 km of multichannel seismic reflection data from the Keathley Canyon Area and vicinity defined the Wisconsinan-Holocene sequence and its seismic facies. In interbasinal areas and in the southern part of the study area where salt is shallow, the Wisconsinan-Holocene sequence consists mainly of low-amplitude (LA) facies underlain by strong basal-reflection (SBR) facies. The LA facies occasionally show subtle onlaps against SBR facies and grade upward into a draping pattern. Onlapping LA facies are interpreted to be a lowstand systems tract deposited by widespread low-energy turbidity currents. Draping LA facies at the top may consist of hemipelagic or pelagic sediments. The SBR facies are interpreted to consist of condensed sections formed during sea-level rises and highstands. Within basins, moderate-to-high amplitude-continuous (MHC) and hummocky-to-chaotic (HC) facies occur below LA facies. The MHC facies show a pattern of flat-lying or gently dipping reflections that onlap SBR facies. Onlapping MHC facies often grade upward into a conformable pattern and are obscured by transition into LA facies. The MHC facies are interpreted as alternating coarse- and fine-grained turbidites deposited during sea-level falls and/or lowstands. The HC facies occur commonly associated with MHC facies. The HC facies may represent slope fans formed by mass-transport processes or gravity flows during sea-level falls and/or lowstands.

  12. The Asphalt Ecosystem of the Southern Gulf of Mexico: Results from F/S METEOR Cruise M114

    NASA Astrophysics Data System (ADS)

    MacDonald, I. R.; Sahling, H.; Bohrmann, G.; Schubotz, F.

    2015-12-01

    Asphalt volcanism in the deep ocean can generate substantial areas of hard substratum and hydrocarbon fluxes that support chemosynthetic communities. The process was first described in the southern Gulf of Mexico following the discovery in 2003 of Chapopote, a knoll at 3200m depth that includes large asphalt flows. F/S METEOR returned to the region in February and March, 2015 to quantify the extent and characteristics of Chapopote and other asphalt-hosting knolls using the SEAL AUV, QUEST ROV, shipborne acoustics, and autonomous instrument landers. Preliminary findings have greatly expanded the number of confirmed asphalt volcanoes, as well as sites where seepage was detected as gas flares in the water column. The morphology of asphalt flows, which was investigated using large-scale photo-mosaicking techniques, indicated that they form with a complex interplay of gravity flows, buoyant uplift, and chemical weathering. Geochemical analysis of asphalt samples is underway to investigate the ages of material and the time-constants of alterations after exposure at the seafloor. Rapid gas hydrate formation had generated massive seafloor deposits at several sites. Notably, gas hydrate mounds had been colonized by aggregations of 2m long tubeworms that extended over areas approaching 1000 sq m in some cases. The biological community comprised an abundant assemblage in which the caridean shrimp Alvinocaris muricola and the squat lobsters Munidopsis geyeri and M. exuta were numerically dominant. Chemosynthetic fauna were primarily the tubeworm Escarpia laminate, observed on asphalt surfaces and gas hydrate substrate and the mussel Bathymodiolus heckarae, observed around active gas vents. Prospects for oil and gas development in the region raise questions regarding appropriate measures for safeguarding lush chemosynthetic communities.

  13. 77 FR 29682 - Gulf of Mexico, Outer Continental Shelf, Central Planning Area, Oil and Gas Lease Sale 216/222

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ... Bureau of Ocean Energy Management Gulf of Mexico, Outer Continental Shelf, Central Planning Area, Oil and...) for Gulf of Mexico (GOM), Outer Continental Shelf (OCS) Oil and Gas Lease Sale: 2012 Central Planning... of the continental shelf boundary between the United States and Mexico. The CPA lease sale...

  14. Age of menarche in Oaxaca, Mexico, schoolgirls, with comparative data for other areas of Mexico.

    PubMed

    Malina, R M; Chumlea, C; Stepick, C D; Lopez, F G

    1977-11-01

    Status quo menarcheal information was collected for a mixed urban colonia and rural sample of 315 girls in the Valley of Oaxaca, Mexico. Comparative status quo data for girls from four major urban centres in Mexico, and for a rural sample were also analysed. Median age at menarche (estimated by probit analysis) for Oaxaca girls was 14.27 +/- 0.20 years, about 0.5 year later than that for the rural sample from Tampico-Altamira, Tamaulipas (13.79 +/- 0.20 years), and approximately 1.5 years later than that for girls from the four urban centres in Mexico (12.55 +/- 0.10, 12.61 +/- 0.08, 12.75 +/- 0.10, 12.76 +/- 0.07 years). The timing of menarche in Oaxaca girls is similar to that for rural Mayans in Guatemala. Ages at menarche for urban Mexican girls are somewhat lower than those for girls of North-west European ancestry and of North American girls of European ancestry. PMID:596820

  15. Impact of environmental manipulation for Anopheles pseudopunctipennis Theobald control on aquatic insect communities in southern Mexico.

    PubMed

    Bond, J G; Quiroz-Martínez, H; Rojas, J C; Valle, J; Ulloa, A; Williams, T

    2007-06-01

    Extraction of filamentous algae from river pools is highly effective for the control of Anophelespseudopunctipennis in southern Mexico. We determined the magnitude of changes to the aquatic insect community following single annual perturbations performed over two years. In 2001, algae were manually removed from all the pools in a 3 km long section of the River Coatán, Mexico, while an adjacent section was left as an untreated control. In 2002, the treatments of both zones were switched and algal extraction was repeated. The abundance of An. pseudopunctipennis larvae + pupae was dramatically reduced by this treatment and remained depressed for two to three months. A total of 11,922 aquatic insects from ten orders, 40 families, and 95 genera were collected in monthly samples taken over five months of each year. Algal extraction did not reduce the overall abundance of aquatic insects in river pools, but a greater abundance and a greater richness of taxa were observed in 2002 compared to the previous year. This was associated with reduced precipitation and river discharge in 2002 compared to 2001. Shannon diversity index values were significantly depressed following algal extraction for a period of three months, in both years, before returning to values similar to those of the control zone. However, differences between years were greater than differences between treatments within a particular year. When insects were classified by functional feeding group (FFG), no significant differences were detected in FFG densities between extraction and control zones over time in either year of the study. Similarly, percent model affinity index values were classified as "not impacted" by the extraction process. Discriminant function analysis identified two orders of insects (Diptera and Odonata), water temperature, dissolved oxygen and conductivity, and river volume (depth, width, and discharge) as being of significant value in defining control and treatment groups in both years

  16. Topographic control of the cyclonic circulation in the southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Perez-Brunius, P.; García-Carrillo, P.; Dubranna, J.; Candela, J.; Sheinbaum, J.

    2011-12-01

    Until recently, the Bay of Campeche was the most undersampled area of the Gulf of Mexico. Three years of mooring and drifter observations of the upper-layer velocity field have greatly improved our understanding of the dynamics in this region. They show that the mean cyclonic circulation, previously reported in the literature, is a persistent feature that extends down to 800-1000m. The gyre's size and location appear determined by the particular configuration of the isobaths in the region, which consists of a deep basin to the west, and a shallower, gently sloping submarine fan to the east. Data suggest that the flow is equivalent barotropic, and that potential vorticity conservation explains the gyre's topographic control. Preliminary results indicate that the interaction of the gyre with Loop Current eddies and wind-stress curl variations can also be explained by this hypothesis.

  17. Mexico

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of Mexico was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. In areal extent, Mexico is the third largest country on the continent of North America (not counting Greenland, which is a province of Denmark), comprised of almost 2 million square kilometers (756,000 square miles) of land. Home to roughly 100 million people, Mexico is second only to the United States in population, making it the world's largest Spanish-speaking nation. To the north, Mexico shares its border with the United States-a line that runs some 3,100 kilometers (1,900 miles) east to west. About half of this border is defined by the Rio Grande River, which runs southeast to the Gulf of Mexico (partially obscured by clouds in this image) and marks the dividing line between Texas and Mexico. Toward the upper left (northwest) corner of this image is the Baja California peninsula, which provides the western land boundary for the Gulf of California. Toward the northwestern side of the Mexican mainland, you can see the Sierra Madre Occidental Mountains (brownish pixels) running southeast toward Lake Chapala and the city of Guadalajara. About 400 km (250 miles) east and slightly south of Lake Chapala is the capital, Mexico City. Extending northward from Mexico City is the Sierra Madre Oriental Mountains, the irregular line of brownish pixels that seem to frame the western edges of the bright white cumulus clouds in this image. Between these two large mountain ranges is a large, relatively dry highland region. To the south, Mexico shares borders with Guatemala and Belize, both of which are located south of Mexico's Yucatan Peninsula. Image courtesy Reto Stockli, Brian Montgomery, and Robert Simmon, based on data from the MODIS Science Team

  18. SPLASH: A Southern Parkes Large Area Survey in Hydroxyl

    NASA Astrophysics Data System (ADS)

    Dawson, Joanne; Caswell, James; Gomez, Jose F.; Mcclure-Griffiths, Naomi; Lo, Nadia; Jones, Paul; Dickey, John; Cunningham, Maria; Green, James; Carretti, Ettore; Ellingsen, Simon; Walsh, Andrew; Purcell, Cormac; Breen, Shari; Hennebelle, Patrick; Imai, Hiroshi; Lowe, Vicki; Gibson, Steven; Jones, Courtney; Krishnan, Vasaant

    2013-10-01

    The OH 18 cm lines are powerful and versatile probes of diffuse molecular gas, that may trace a largely unstudied component of the Galactic ISM. SPLASH (the Southern Parkes Large Area Survey in Hydroxyl) is a large, unbiased and fully-sampled survey of OH emission, absorption and masers in the Galactic Plane that will achieve sensitivities an order of magnitude better than previous work. The survey will answer critical questions on the global distribution of diffuse OH, the degree to which it traces ‘hidden’ material caught between the regimes probed by traditional tracers of the neutral ISM, and its role as a probe of molecular cloud formation. As a blind survey for all four ground-state transitions, SPLASH will also detect many new OH masers, facilitating a broad range of astrophysical studies. This proposal requests 670 hours spread over two semesters to complete Phase 1 of the SPLASH project, which will map 152 square degrees in the inner Galactic Plane, including the Galactic Centre. Following the ongoing success of the project, we request that its pre-graded status be renewed for a final two semesters.

  19. Bovine mastitis in selected areas of southern Ethiopia.

    PubMed

    Dego, O Kerro; Tareke, F

    2003-06-01

    A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian. were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.21%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples. Staphylococcus accounted for 39.2%. Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area. PMID:12797409

  20. Late Pleistocene-Holocene alluvial stratigraphy of southern Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    Antinao, José Luis; McDonald, Eric; Rhodes, Edward J.; Brown, Nathan; Barrera, Wendy; Gosse, John C.; Zimmermann, Susan

    2016-08-01

    A late Pleistocene to Holocene alluvial stratigraphy has been established for the basins of La Paz and San José del Cabo, in the southern tip of the Baja California peninsula, Mexico. Six discrete alluvial units (Qt1 through Qt6) were differentiated across the region using a combination of geomorphologic mapping, sedimentological analysis, and soil development. These criteria were supported using radiocarbon, optically stimulated luminescence and cosmogenic depth-profile geochronology. Major aggradation started shortly after ∼70 ka (Qt2), and buildup of the main depositional units ended at ∼10 ka (Qt4). After deposition of Qt4, increasing regional incision of older units and the progressive development of a channelized alluvial landscape coincide with deposition of Qt5 and Qt6 units in a second, incisional phase. All units consist of multiple 1-3 m thick alluvial packages deposited as upper-flow stage beds that represent individual storms. Main aggradational units (Qt2-Qt4) occurred across broad (>2 km) channels in the form of sheetflood deposition while incisional stage deposits are confined to channels of ∼0.5-2 km width. Continuous deposition inside the thicker (>10 m) pre-Qt5 units is demonstrated by closely spaced dates in vertical profiles. In a few places, disconformities between these major units are nevertheless evident and indicated by partly eroded buried soils. The described units feature sedimentological traits similar to historical deposits formed by large tropical cyclone events, but also include characteristics of upper-regime flow sedimentation not shown by historical sediments, like long (>10 m) wavelength antidunes and transverse ribs. We interpret the whole sequence as indicating discrete periods during the late Pleistocene and Holocene when climatic conditions allowed larger and more frequent tropical cyclone events than those observed historically. These discrete periods are associated with times when insolation at the tropics was

  1. Paleomagnetism of the latest Cretaceous-Paleocene intrusive suite of the Mezcala district, southern Mexico

    NASA Astrophysics Data System (ADS)

    Molina Garza, Roberto S.; Valdivia, Luis Alva

    2006-10-01

    Paleomagnetic data from three plutons of the latest Cretaceous to early Tertiary Mezcala intrusive suite, of the Mezcala mining district in northern Guerrero State, in southern Mexico, are characterized by well-defined near univectorial magnetizations of both normal and reverse polarities. The magnetizations reside primarily in a ferromagnetic cubic phase (magnetite or maghemite) and partly in hematite. Within-site dispersion is relatively small, but between-site dispersion is not. The overall mean for 9 selected sites is of D=318.5° and I=47.1° (k=18.5; α95=12.3°), and is discordant with respect to the reference direction for North America. The discordance may be explained by tilt down-to-the-northeast of the structural block that contains the intrusive suite of about 40° about a NW-SE trending axis, or perhaps more likely and based on additional geological evidence, by a combination of ˜20° of counterclockwise rotation about a vertical axis and a smaller amount of tilt. Vertical-axis-rotation is supported by paleomagnetic data from nearby localities, whereas a small magnitude of tilt is supported by geological field relations. This result is consistent with the hypothesis that Laramide structures of the Guerrero-Morelos platform were reactivated by a younger deformation event, and that there is a deformation event superimposed that involves lateral slip. The contrasting orientation of NW-SE trending structures within the Mezcala mining district affecting the plutons, and N-S trending Laramide structures, suggests that the discordant paleomagnetic directions are best explained by a combination of tilt and rotation.

  2. Assessing Colorectal Cancer Screening Behaviors and Knowledge among At-Risk Hispanics in Southern New Mexico*

    PubMed Central

    Sanchez, Janeth I.; Palacios, Rebecca; Thompson, Beti; Martinez, Vanessa; O’Connell, Mary A.

    2014-01-01

    Purpose Colorectal cancer (CRC) mortality rates in New Mexico (NM) continue to be higher than national rates. Hispanic CRC mortality rates in NM surpass those of overall Hispanics in the US. This study was designed to characterize and understand factors contributing to low CRC screening rates in this border region. Methods A CRC Knowledge Assessment Survey (KAS) was administered in either English or Spanish to 247 individuals attending community events throughout southern NM. A subset of these individuals completed an online CRC risk assessment survey managed by the National Cancer Institute (NCI). Data analysis tested for significant differences in knowledge, physician-patient CRC interactions, CRC risk level perception, and screening rates across diverse ethnic and age groups. Results Both CRC knowledge and physician-patient CRC interactions were positively associated with participant screening history. Significant age and ethnic differences for CRC knowledge, physician-patient CRC interactions, and screening history in the NM border sample were also seen. Age-eligible Hispanics (50+) as well as those less than 50 years of age had lower CRC knowledge and were less likely to engage in physician-patient CRC interactions than non-Hispanic Whites (NHWs). The age-eligible Hispanics also reported lower CRC screening rates than their NHW counterparts. Conclusions Low CRC knowledge and limited physician-patient CRC interactions appear to contribute to low screening rates in this NM population. Expanding education and outreach efforts for this border population are essential to promote early CRC detection and thereby decrease overall CRC mortality rates. PMID:25621179

  3. Petroleum degradation and associated microbial signatures at the Chapopote asphalt volcano, Southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Schubotz, Florence; Lipp, Julius S.; Elvert, Marcus; Kasten, Sabine; Mollar, Xavier Prieto; Zabel, Matthias; Bohrmann, Gerhard; Hinrichs, Kai-Uwe

    2011-08-01

    At the Chapopote Knoll in the Southern Gulf of Mexico, deposits of asphalt provide the substrate for a prolific cold seep ecosystem extensively colonized by chemosynthetic communities. This study investigates microbial life and associated biological processes within the asphalts and surrounding oil-impregnated sediments by analysis of intact polar membrane lipids (IPLs), petroleum hydrocarbons and stable carbon isotopic compositions (δ 13C) of hydrocarbon gases. Asphalt samples are lightly to heavily biodegraded suggesting that petroleum-derived hydrocarbons serve as substrates for the chemosynthetic communities. Accordingly, detection of bacterial diester and diether phospholipids in asphalt samples containing finely dispersed gas hydrate suggests the presence of hydrocarbon-degrading bacteria. Biological methanogenesis contributes a substantial fraction to the methane captured as hydrate in the shallow asphalt deposits evidenced by significant depletion in 13C relative to background thermogenic methane. In sediments, petroleum migrating from the subsurface stimulates both methanogenesis and methanotrophy at a sulfate-methane transition zone 6-7 m below the seafloor. In this zone, microbial IPLs are dominated by archaeal phosphohydroxyarchaeols and archaeal diglycosidic diethers and tetraethers. Bacterial IPLs dominate surface sediments that are impregnated by severely biodegraded oil. In the sulfate-reduction zone, diagnostic IPLs indicate that sulfate-reducing bacteria (SRB) play an important role in petroleum degradation. A diverse mixture of phosphohydroxyarchaeols and mixed phospho- and diglycosidic archaeal tetraethers in shallow oil-impregnated sediments point to the presence of anaerobic methane-oxidizing ANME-2 and ANME-1 archaea, respectively, or methanogens. Archaeal IPLs increase in relative abundance with increasing sediment depth and decreasing sulfate concentrations, accompanied by a shift of archaeol-based to tetraether-based archaeal IPLs. The

  4. Soaring migratory birds avoid wind farm in the Isthmus of Tehuantepec, southern Mexico.

    PubMed

    Villegas-Patraca, Rafael; Cabrera-Cruz, Sergio A; Herrera-Alsina, Leonel

    2014-01-01

    The number of wind farms operating in the Isthmus of Tehuantepec, southern Mexico, has rapidly increased in recent years; yet, this region serves as a major migration route for various soaring birds, including Turkey Vultures (Cathartes aura) and Swainson's Hawks (Buteo swainsoni). We analyzed the flight trajectories of soaring migrant birds passing the La Venta II wind farm during the two migratory seasons of 2011, to determine whether an avoidance pattern existed or not. We recorded three polar coordinates for the flight path of migrating soaring birds that were detected using marine radar, plotted the flight trajectories and estimated the number of trajectories that intersected the polygon defined by the wind turbines of La Venta II. Finally, we estimated the actual number of intersections per kilometer and compared this value with the null distributions obtained by running 10,000 simulations of our datasets. The observed number of intersections per kilometer fell within or beyond the lower end of the null distributions in the five models proposed for the fall season and in three of the four models proposed for the spring season. Flight trajectories had a non-random distribution around La Venta II, suggesting a strong avoidance pattern during fall and a possible avoidance pattern during spring. We suggest that a nearby ridgeline plays an important role in this pattern, an issue that may be incorporated into strategies to minimize the potential negative impacts of future wind farms on soaring birds. Studies evaluating these issues in the Isthmus of Tehuantepec have not been previously published; hence this work contributes important baseline information about the movement patterns of soaring birds and its relationship to wind farms in the region. PMID:24647442

  5. [Growth and mortality of the mollusk Pteria sterna in wild banks of Southern Baja California, Mexico].

    PubMed

    Wright-López, Humberto; Holguín-Quiñones, Oscar; Arreguín-Sánchez, Francisco; Roque-Villada, Irene

    2009-09-01

    The Gulf of California nacre shell Pteria sterna is an important marine resource in Mexico, and the main species for "half" and round pearl production in the American continent. Wild spat can only be extracted legally for research or culture activities. This study calculates growth and mortality parameters for wild stocks in the eastern coast of Southern Baja California. Height's data (353 dorso-ventral measurements) were taken from 1997 to 1999 at Santa Rosalia, Mulegé and Loreto Bay coast. The maximum length was estimated at 130.35 mm (124.22-136.48 mm, p>0.95). The length frequency data were set in a "virtual year". Seasonal von Bertalanffy growth parameters were calculated in the ELEFAN I routine, the values are: L(infinity) = 156.02 mm, k = 0.48 year(-1), t0 = -0.216 years, C = 0.43, WP = 0.73. and t(s) = 0.5. The growth performance index was phi' = 4.068. The total mortality was calculated from length-converted catch curve Z = 3.34 year(-1). The length-weight relationship was fixed for the equation W = 0.000756 * L(i)(2.7075) (r2 = 0.90, n = 233). The growth parameters values in experimental repopulation conditions are quite different, in contrast with the growth estimated in wild stocks oysters. The value of total mortality is similar to the estimations for Pinctada fucata populations from the Red Sea and P. radiata from the Mediterranean Sea. PMID:19928461

  6. Soaring Migratory Birds Avoid Wind Farm in the Isthmus of Tehuantepec, Southern Mexico

    PubMed Central

    Villegas-Patraca, Rafael; Cabrera-Cruz, Sergio A.; Herrera-Alsina, Leonel

    2014-01-01

    The number of wind farms operating in the Isthmus of Tehuantepec, southern Mexico, has rapidly increased in recent years; yet, this region serves as a major migration route for various soaring birds, including Turkey Vultures (Cathartes aura) and Swainson's Hawks (Buteo swainsoni). We analyzed the flight trajectories of soaring migrant birds passing the La Venta II wind farm during the two migratory seasons of 2011, to determine whether an avoidance pattern existed or not. We recorded three polar coordinates for the flight path of migrating soaring birds that were detected using marine radar, plotted the flight trajectories and estimated the number of trajectories that intersected the polygon defined by the wind turbines of La Venta II. Finally, we estimated the actual number of intersections per kilometer and compared this value with the null distributions obtained by running 10,000 simulations of our datasets. The observed number of intersections per kilometer fell within or beyond the lower end of the null distributions in the five models proposed for the fall season and in three of the four models proposed for the spring season. Flight trajectories had a non-random distribution around La Venta II, suggesting a strong avoidance pattern during fall and a possible avoidance pattern during spring. We suggest that a nearby ridgeline plays an important role in this pattern, an issue that may be incorporated into strategies to minimize the potential negative impacts of future wind farms on soaring birds. Studies evaluating these issues in the Isthmus of Tehuantepec have not been previously published; hence this work contributes important baseline information about the movement patterns of soaring birds and its relationship to wind farms in the region. PMID:24647442

  7. Mexico.

    PubMed

    1988-02-01

    Focus in this discussion of Mexico is on the following: geography; the people; history; political conditions; the economy; foreign relations; and relations between the US and Mexico. As of July 1987, the population of Mexico numbered 81.9 million with an estimated annual growth rate of 2.09%. 60% of the population is Indian-Spanish (mestizo), 30% American Indian, 9% white, and 1% other. Mexico is the most populous Spanish-speaking country in the world and the 2nd most populous country in Latin America. Education is decentralized and expanded. Mexico's topography ranges from low desert plains and jungle-like coastal strips to high plateaus and rugged mountains. Hernan Cortes conquered Mexico in 1919-21 and founded a Spanish colony that lasted for almost 300 years. Independence from Spain was proclaimed by Father Miguel Hidalgo on September 16, 1810; the republic was established on December 6, 1822. Mexico's constitution of 1917 provides for a federal republic with a separation of powers into independent executive, legislative, and judicial branches of government. Significant political themes of the administration of President Miguel de la Madrid Hurtado, who began his 6-year term in 1982, have been restructuring the economy, liberalizing trade practices, decentralizing government services, and eliminating corruption among public servants. In 1987, estimates put the real growth of the Mexican economy at 1.5%; the gross domestic product (GDP) had shrunk by 3.5% in 1986. Yet, on the positive side, Mexico's international reserves increased to record levels in 1987 (to about $15 billion), and its current account surplus reached more than $3 billion. Mexico has made considerable progress in moving to restructure its economy. It has substantially reduced impediments to international trade and has moved to reduce the number of parastatal firms. 1987 was the 2nd consecutive year in which Mexico recorded triple-digit inflation; inflation reached 158.8%. Other problems include

  8. 33 CFR 166.200 - Shipping safety fairways and anchorage areas, Gulf of Mexico.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Mexico. (a) Purpose. Fairways and anchorage areas as described in this section are established to control...°28′00″ 84°21′30″ (51) Charlotte Anchorage. The area within rhumb lines joining points at: Latitude... Navigation or danger markings must be installed as required by 33 CFR Subchapter C. (c) Special...

  9. 33 CFR 166.200 - Shipping safety fairways and anchorage areas, Gulf of Mexico.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Mexico. (a) Purpose. Fairways and anchorage areas as described in this section are established to control...°28′00″ 84°21′30″ (51) Charlotte Anchorage. The area within rhumb lines joining points at: Latitude... Navigation or danger markings must be installed as required by 33 CFR Subchapter C. (c) Special...

  10. 33 CFR 166.200 - Shipping safety fairways and anchorage areas, Gulf of Mexico.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Mexico. (a) Purpose. Fairways and anchorage areas as described in this section are established to control...°28′00″ 84°21′30″ (51) Charlotte Anchorage. The area within rhumb lines joining points at: Latitude... Navigation or danger markings must be installed as required by 33 CFR Subchapter C. (c) Special...

  11. 33 CFR 166.200 - Shipping safety fairways and anchorage areas, Gulf of Mexico.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Mexico. (a) Purpose. Fairways and anchorage areas as described in this section are established to control...°28′00″ 84°21′30″ (51) Charlotte Anchorage. The area within rhumb lines joining points at: Latitude... Navigation or danger markings must be installed as required by 33 CFR Subchapter C. (c) Special...

  12. Devonian-Ordovician Magmatism in Chiapas Massif, Southern Maya Block, Mexico

    NASA Astrophysics Data System (ADS)

    Pompa-Mera, V.; Schaaf, P.; Weber, B.; Solis-Pichardo, G.; Hernandez-Trevino, T.; Ortega-Gutierrez, F.

    2008-12-01

    The Chiapas Massif (CM) is located in SE Mexico and extends over an area of more than 20,000 Km2 parallel to the Pacific coast between the Isthmus of Tehuantepec and the Guatemalan border. It constitutes the largest batholitic complex in Mexico and belongs to the Maya Block. The CM is predominantly formed by igneous, metaigneous and metasedimentary rocks. In the central CM several magmatic and metamorphic events have been identified in igneous rocks between Late Permian and Triassic times (220-240 Ma), together with a Jurassic tectonothermal event. Recent geochronological studies have been focused on granitic rocks from the central-southeastern CM and from this area, single grain zircon ages were also obtained from metasedimentary rocks. The results suggest that the basement rocks of the eastern CM and the Maya Block underwent several tectonothermal events since Ordovician and Devonian times. In this work, we present new data of magmatic and metamorphic rocks from the easternmost part of CM which confirms this hypothesis. Additionally, we present a semi-detailed geological map of this area showing some field relationship between the different units. We identified a new basal sequence significantly older than the Santa Rosa Formation, which has been considered up to now as forming the major underlying sequence of the CM, as well as the occurrence of several magmatic events in the Maya Block and in rocks from surrounding areas. The petrological, geochemical and geochronological features of these rocks show continuous crust recycling, the occurrence of within-plate magmatism in some parts with inherited Greenvillian and Archaean zircon grains as well as the occurrence of arc magmatism previous to accretion, deformation and terrane separation of the crustal blocks. Our new geochronological results obtained from the south easternmost part of the CM include a Rb-Sr biotite-muscovite age of 392+/-9 Ma and an Ar-Ar muscovite age of 406+/- 4 Ma from a tectonized granitic

  13. Geohydrology and water resources of the Papago Farms-Great Plain area, Papago Indian Reservation, Arizona, and the upper Rio Sonoyta area, Sonora, Mexico

    USGS Publications Warehouse

    Hollett, K.J.

    1983-01-01

    The Papago Farms-Great Plain and upper Rio Sonoyta study area includes about 490 square miles in south-central Arizona and north-central Sonora, Mexico. In the study area 23,700 acre-feet of ground water from the basin-fill deposits was used to irrigate more than 5,000 acres in 1981. Surface water is not a reliable source for irrigation or public supply. Ground water enters the area as underflow from the north and east and as recharge from the montains, moves through basin-margin sediments , around the basin-center clays, and exits the area to the west beneath the Rio Sonoyta. Ground-water withdrawals in the upper Rio Sonoyta area do not appear to have an effect on water levels in the Papago Farms-Great Plain area. Depth to water ranges from 500 feet near the southern boundary to 150 feet in the center of study area. About 10 million acre-feet of recoverable ground water is stored in the upper 400 feet of the aquifer. Storage is being depleted at a rate of 19,000 acre-feet per year. The ground water is a sodium and bicarbonate type and has an anomalously high content of arsenic and fluoride. (USGS)

  14. The impact of antecedent fire area on burned area in southern California coastal ecosystems.

    PubMed

    Price, Owen F; Bradstock, Ross A; Keeley, Jon E; Syphard, Alexandra D

    2012-12-30

    Frequent wildfire disasters in southern California highlight the need for risk reduction strategies for the region, of which fuel reduction via prescribed burning is one option. However, there is no consensus about the effectiveness of prescribed fire in reducing the area of wildfire. Here, we use 29 years of historical fire mapping to quantify the relationship between annual wildfire area and antecedent fire area in predominantly shrub and grassland fuels in seven southern California counties, controlling for annual variation in weather patterns. This method has been used elsewhere to measure leverage: the reduction in wildfire area resulting from one unit of prescribed fire treatment. We found little evidence for a leverage effect (leverage = zero). Specifically our results showed no evidence that wildfire area was negatively influenced by previous fires, and only weak relationships with weather variables rainfall and Santa Ana wind occurrences, which were variables included to control for inter-annual variation. We conclude that this is because only 2% of the vegetation burns each year and so wildfires rarely encounter burned patches and chaparral shrublands can carry a fire within 1 or 2 years after previous fire. Prescribed burning is unlikely to have much influence on fire regimes in this area, though targeted treatment at the urban interface may be effective at providing defensible space for protecting assets. These results fit an emerging global model of fire leverage which position California at the bottom end of a continuum, with tropical savannas at the top (leverage = 1: direct replacement of wildfire by prescribed fire) and Australian eucalypt forests in the middle (leverage ~ 0.25). PMID:23064248

  15. Black howler monkey (Alouatta pigra) activity, foraging and seed dispersal patterns in shaded cocoa plantations versus rainforest in southern Mexico.

    PubMed

    Zárate, Diego A; Andresen, Ellen; Estrada, Alejandro; Serio-Silva, Juan Carlos

    2014-09-01

    Recent evidence has shown that primates worldwide use agroecosystems as temporary or permanent habitats. Detailed information on how these primates are using these systems is scant, and yet their role as seed dispersers is often implied. The main objective of this study was to compare the activity, foraging patterns and seed dispersal role of black howler monkeys (Alouatta pigra) inhabiting shaded cocoa plantations and rainforest in southern Chiapas, Mexico. We gathered data on three monkey groups living in shaded cocoa plantations and three groups living in rainforest, using focal sampling, and collecting fecal samples. General activity and foraging patterns were similar in both habitats, with the exception that monkeys in the cocoa habitat spent more time feeding on petioles. Monkeys in shaded cocoa plantations dispersed 51,369 seeds (4% were seeds ≥3 mm width) of 16 plant species. Monkeys in the rainforest dispersed 6,536 seeds (78% were seeds ≥3 mm width) of 13 plant species. Our data suggest that the difference between habitats in the proportion of large versus small seeds dispersed reflects differences in fruit species abundance and availability in cocoa versus forest. Mean seed dispersal distances were statistically similar in both habitats (cocoa = 149 m, forest = 86 m). We conclude that the studied cocoa plantations provide all elements necessary to constitute a long-term permanent habitat for black howler monkeys. In turn, howler monkeys living in these plantations are able to maintain their functional role as seed dispersers for those native tree and liana species present within their areas of activities. PMID:24668557

  16. Southern Cordilleran Basaltic Andesite suite, southern Chihuahua, Mexico: A link between Tertiary continental arc and flood basalt magmatism in the North America

    SciTech Connect

    Cameron, K. L.; Nimz, G. J.; Kuentz, D.; Niemeyer, S.; Gunn, S.

    1989-06-10

    Mid-Cenozoic orogenic andesites and ignimbrites of western Mexico, southwestern New Mexico, and Arizona are commonly capped by basaltic andesites, most from 29--20 Ma. We refer to these mafic lavas as the Southern Cordilleran Basaltic Andesite (SCORBA) suite, and they may constitute the most extensive Cenozoic basaltic suite in North America. The SCORBA suite has trace element and isotopic characteristics of orogenic (arc) rocks (i.g., Ba/Nb/gt/40), and silica content (53--56% SiO/sub 2/) like the Grande Ronde Basalt, which represents about 80% of the volume of the Columbia River Group. Geochemical and isotopic data are presented on SCORBA lavas and rare mafic lavas (PRE-SCORBA) interlayered with older ignimbrites from a 700-km-long NE-SW transect of southern Chihuahua, Mexico. SCORBA and PRE-SCORBA lavas with relatively low K/P (/lt/7) and differing Ba/Nd (50 versus 18) have similar isotopic compositions, arguing against their isotopic signatures being controlled by crustal assimilation. Along the entire length of the transect, the basaltic rocks have /var epsilon//sub Nd/ and /sup 87/Sr//sup 86/Sr near bulk Earth and /sup 206/Pb//sup 204/Pb and /sup 207/Pb//sup 204/Pb ratios that lie along a 1.7 Ga pseudoisochron. The Pb isotopic variation is geographically controlled, becoming more radiogenic from east to west, reflecting mixing in mantle source regions. The eastern mantle source has low/sup 206/Pb//sup 204/Pb and is a mixture of an enriched, enriched-mantle-like (EMI) component with one or more depleted components, which could include an intraplate component with relatively high Nb/Y (/gt/0.8).

  17. 33 CFR 165.840 - Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South of New Orleans, LA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Limited Access Areas Eighth Coast Guard District § 165.840 Regulated Navigation Area, Gulf of Mexico... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South of New Orleans, LA. 165.840 Section 165.840...

  18. 33 CFR 165.840 - Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South of New Orleans, LA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Limited Access Areas Eighth Coast Guard District § 165.840 Regulated Navigation Area, Gulf of Mexico... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South of New Orleans, LA. 165.840 Section 165.840...

  19. The potential of fruit trees to enhance converted habitats for migrating birds in southern Mexico

    USGS Publications Warehouse

    Foster, M.S.

    2007-01-01

    Migration routes used by Nearctic migrant birds can cover great distances; they also differ among species, within species, and between years and seasons. As a result, migration routes for an entire migratory avifauna can encompass broad geographic areas, making it impossible to protect continuous stretches of habitat sufficient to connect the wintering and breeding grounds for most species. Consequently, ways to enhance habitats converted for human use (i.e. for pasture, crop cultivation, human settlement) as stopover sites for migrants are especially important. Shelterbelts around pastures and fields, if planted with species targeted to support migrant (and resident) bird species that naturally occupy mature forest habitats and that are at least partially frugivorous, could be a powerful enhancement tool for such species, if the birds will enter the converted areas to feed. I tested this approach for Nearctic migrant birds during the spring migration through an area in Chiapas, Mexico. Mature forest tree species whose fruits are eaten by birds were surveyed. Based on life form, crop size and fruit characteristics, I selected three tree species for study: Cymbopetalum mayanum (Annonaceae), Bursera simaruba (Burseraceae) and Trophis racemosa (Moraceae). I compared the use of fruits of these species by migrants and residents in forest with their use of the fruits of isolated individuals of the same species in pasture and cropland. All three plant species were useful for enhancing converted habitats for forest-occupying spring migrants, although species differed in the degree to which they entered disturbed areas to feed on the fruits. These tree species could probably enhance habitats for migrants at sites throughout the natural geographic ranges of the plants; in other geographic areas for other target bird groups, other tree species might be more appropriate.

  20. Guayape-Papalutla fault system: A continuous Cretaceous structure from southern Mexico to the Chortís block? Tectonic implications

    NASA Astrophysics Data System (ADS)

    Silva-Romo, G.

    2008-01-01

    Recent papers have opened the debate over whether the Chortísblock was located off the coast of southern Mexico or in a moreoutboard position, and this led me to explore whether correlationswith older structures could be established to determine theevolution of the southwest corner of the North America plate.In this paper I hypothesize that the Papalutla fault of Mexicoand the Guayape fault system of Honduras, both considered tobe terrane boundaries, were roughly continuous in the Cretaceous,extending from southern Mexico to the Chortís block.They influenced Early Cretaceous clastic sedimentation of theZicapa Formation on the Guerrero-Morelos Platform (southernMexico) and the Tepemechin Formation of the Central Chortísterrane (Honduras). The units accumulated in fault-bounded basinsassociated with left-lateral slip. The basins developed in theCentral Chortís terrane and Guerrero-Morelos Platform.Both geological entities appear to represent a continuous Cretaceousgeologic province characterized by a trangression that occurredearlier in Honduras than in southern Mexico. This nonrotationalhypothesis for the location of the Chortís block adjacentto southern Mexico during the Cretaceous is consistent withnortheastward displacement of the Caribbean plate during Cretaceoustime and implies 1500 km of Chortís block displacementduring the Cenozoic.

  1. Spawning aggregations of three protogynous groupers in the southern Gulf of Mexico.

    PubMed

    Tuz-Sulub, A; Brulé, T

    2015-01-01

    Spawning aggregations of red hind Epinephelus guttatus, tiger grouper Mycteroperca tigris and yellowfin grouper Mycteroperca venenosa were identified at two coral-reef systems: Arrecife Alacranes (emergent bank reef) and Bajos del Norte (submerged bank reef) on the continental shelf of the Yucatan Peninsula (Campeche Bank), Mexico. At both reefs, E. guttatus forms large spawning aggregations between February and March. At Bajos del Norte, M. tigris reproduces in a small, low-density aggregation in May, while M. venenosa aggregates at high densities for spawning between March and May. Multi-species use of an aggregation site by E. guttatus and M. venenosa was observed at Bajos del Norte. The identified spawning aggregations are apparently stable in location over time, and all three species were commonly observed to spawn within 1 week following the full moon. Development and survival of the larvae spawned in these aggregations are probably aided by a seasonal (spring-summer) upwelling in the north-east Campeche Bank. A permanent area closure at Bajos del Norte, currently outside any specific fisheries management area or regulations, would provide protection needed for the spawning aggregations of these three species. PMID:25557429

  2. Sedimentology and paleoecology of an Eocene Oligocene alluvial lacustrine arid system, Southern Mexico

    NASA Astrophysics Data System (ADS)

    Beraldi-Campesi, Hugo; Cevallos-Ferriz, Sergio R. S.; Centeno-García, Elena; Arenas-Abad, Concepción; Fernández, Luis Pedro

    2006-10-01

    A depositional model of the Eocene-Oligocene Coatzingo Formation in Tepexi de Rodríguez (Puebla, Mexico) is proposed, based on facies analysis of one of the best-preserved sections, the Axamilpa Section. The sedimentary evolution is interpreted as the retrogradation of an alluvial system, followed by the progressive expansion of an alkaline lake system, with deltaic, palustrine, and evaporitic environments. The analysis suggests a change towards more arid conditions with time. Fossils from this region, such as fossil tracks of artiodactyls, aquatic birds and cat-like mammals, suggest that these animals traversed the area, ostracods populated the lake waters, and plants grew on incipient soils and riparian environments many times throughout the history of the basin. The inferred habitat for some fossil plants coincides with the sedimentological interpretation of an arid to semiarid climate for that epoch. This combined sedimentological-paleontological study of the Axamilpa Section provides an environmental context in which fossils can be placed and brings into attention important biotic episodes, like bird and camelid migrations or the origin of endemic but extinct plants in this area.

  3. Mexico.

    PubMed

    1984-09-01

    Although Mexico has serious economic and population growth problems, the country is making progress toward solving both of these problems. Mexico has a population of 77.7 million and a population density of 102 persons/square mile. The country has a birth rate of 32/1000, a death rate of 6/1000, and an annual growth rate of 2.6%. The estimated infant mortality rate is 55/1000. The median age of the population is 17.4. Mexico City, with a population of 15 million, is the 3rd largest city in the world, and by 1995, it is expected to be the largest city in the world, with a projected population of 25.2 million. The government vigorously promotes family planning, and the annual population growth rate slowed down from a high of 3.2% in 1970-75 to the current rate of 2.6%. Mexico hopes to achieve replacement level fertility by the year 2000. Other government policies promote income equality, agricultural development, and regional equalization of population growth. In 1982 Mexico's per capita income was US$2270, exports totaled US$21 billion, and imports totaled US$15 billion. By 1976, Mexico's international debt was US$30.2 billion, and inflation was rampant. Recently, the newly elected president, Miguel de la Madrid of the Partido Revolucionario Institutional, obtained a grant of US$39 million from the International Monetary Fund and removed price controls. These efforts should help stabilize Mexico's economy. The country will also need to expand its exports and increase its cultivatable acreage. PMID:12339665

  4. Late Cretaceous shortening and early Tertiary shearing in the central Sierra Madre del Sur, southern Mexico: Insights into the evolution of the Caribbean-North American plate interaction

    NASA Astrophysics Data System (ADS)

    Cerca, Mariano; Ferrari, Luca; López-MartíNez, Margarita; Martiny, Barbara; Iriondo, Alexander

    2007-06-01

    A wide region in the central part of the Sierra Madre del Sur (SMS), southern Mexico, records two deformational phases between the Late Cretaceous and early Tertiary. The first is a progressive approximately E-W shortening phase that spans from the Coniacian to earliest Paleocene and involves deformation of Cretaceous marine sedimentary units. The second phase corresponds to Paleocene to early Eocene deformation that also affects continental sediments and is characterized by gentle folding and counterclockwise rotation of previous shortening structures associated with strike-slip faulting. Here we present geologic, geochronologic, and structural data of two key areas of the Sierra Madre del Sur, the Guerrero-Morelos Platform (GMP), and the Huajuapan-Tamazulapan area in western Oaxaca to describe the geometry, kinematics, and timing of the Late Cretaceous and early Tertiary deformation. Two regional magmatic episodes constrain the deformational history: (1) the first between the Maastrichtian and the Paleocene (68-57 Ma) documents the end of Late Cretaceous shortening in the GMP; and (2) the second between the late Eocene and early Oligocene (37-29 Ma) has a more regional distribution. The time and space analysis of deformation and magmatism in southern Mexico led us to exclude flat subduction or collision of the Guerrero terrane to the west as the cause for Late Cretaceous shortening in the GMP. Considering the similarity in the time and style of deformation with that of the northern Chortis block, we favor an interpretation in which the tectonic evolution of the central and eastern SMS is the result of progressive interaction of the Caribbean plate with the southernmost edge of North America since the Late Cretaceous.

  5. Anelastic attenuation structure of the southern Aegean subduction area

    NASA Astrophysics Data System (ADS)

    Ventouzi, Chrisanthi; Papazachos, Constantinos; Papaioannou, Christos; Hatzidimitriou, Panagiotis

    2014-05-01

    The study of the anelastic attenuation structure plays a very important role for seismic wave propagation and provides not only valuable constraints for the Earth's interior (temperature, relative viscosity, slab dehydration and melt transport) but also significant information for the simulation of strong ground motions. In order to investigate the attenuation structure of the broader Southern Aegean subduction area, acceleration spectra of intermediate depth earthquakes produced from data provided by two local networks which operated in the area were used. More specifically, we employed data from approximately 400 intermediate-depth earthquakes, as these were recorded from the EGELADOS seismic monitoring project which consisted of 65 land stations and 24 OBS recorders and operated during 2005-2007, as well as data from the earlier installed CYCNET local network, which operated during 2002-2005. A frequency-independent path attenuation operator t* was computed for both P and S arrivals for each waveform, using amplitude spectra generated by the recorded data of the aforementioned networks. Initially, estimated P and S traveltimes were examined and modeled as a function of epicentral distance for different groups of focal depths, using data from the CYCNET network in order to obtain the expected arrival information when original arrival times were not available. Two approaches to assess the spectral-decay were adopted for t* determination. Initially, an automated approach was used, where t* was automatically calculated from the slope of the acceleration spectrum, assuming an ω2 source model for frequencies above the corner frequency, fc. Estimation of t* was performed in the frequency band of 0.2 to 25 Hz, using only spectra with a signal-to-noise ratio larger than 3 for a frequency range of at least 4Hz for P-waves and 1Hz for S-waves, respectively. In the second approach, the selection of the linearly-decaying part of the spectra where t* was calculated, was

  6. Geophysical Interpretations of the Southern Espanola Basin, New Mexico, That Contribute to Understanding Its Hydrogeologic Framework

    USGS Publications Warehouse

    Grauch, V.J.S.; Phillips, Jeffrey D.; Koning, Daniel J.; Johnson, Peggy S.; Bankey, Viki

    2009-01-01

    The southern Espanola basin consists of a westward- and northward-thickening wedge of rift fill, composed primarily of Santa Fe Group sediments, that serves as an important aquifer for the city of Santa Fe and surrounding areas. Detailed aeromagnetic surveys were flown to better understand ground-water resources in this aquifer. This report presents a synthesis of these data with gravity data and other constraints. The interpretations were accomplished using qualitative interpretation, state-of-art data analysis techniques, and two- and three-dimensional modeling. The results depict the presence of and depth to many geologic features that have hydrogeologic significance, including shallow faults, different types of igneous units, and basement rocks. The results are presented as map interpretations, geophysical profile models, and a digital surface that represents the base and thickness of Santa Fe Group sediments, as well as vector files of some volcanic features and faults.

  7. Residues of organochlorine pesticides in soils from the southern Sonora, Mexico.

    PubMed

    Cantu-Soto, E U; Meza-Montenegro, Maria Mercedes; Valenzuela-Quintanar, A I; Félix-Fuentes, A; Grajeda-Cota, P; Balderas-Cortes, J J; Osorio-Rosas, C L; Acuña-García, G; Aguilar-Apodaca, M G

    2011-11-01

    Although, the Yaqui and Mayo valleys are the most important agricultural areas in Sonora, there is only limited data of the pesticides residue in soils in these valleys. This study measured the organochlorine pesticides (OCPs) in 234 soil samples (residential and agricultural) from 24 communities. The global results (mean, range) indicated that benzene hexachloride (19.2, ND-938.5 μg g(-1)), endrin (6.6, ND-377.3 μg g(-1)) and DDTs (36.45, ND-679.7 μg g(-1)) were the dominant contaminants. Soil is one of the most important routes of exposure to OCPs in the population of southern Sonora and this study can be used to establish background levels of OCPs. PMID:21761173

  8. Effects of uranium development on erosion and associated sedimentation in southern San Juan Basin, New Mexico

    USGS Publications Warehouse

    Cooley, Maurice E.

    1979-01-01

    A reconnaissance was made of some of the effects of uranium development on erosion and associated sedimentation in the southern San Juan Basin, where uranium development is concentrated. In general, the effects of exploration on erosion are minor, although erosion may be accelerated by the building of access roads, by activities at the drilling sites, and by close concentration of drilling sites. Areas where the greatest effects on erosion and sedimentation from mining and milling operations have occurred are: (1) in the immediate vicinity of mines and mills, (2) near waste piles, and (3) in stream channels where modifications, such as changes in depth have been caused by discharge of excess mine and mill water. Collapse of tailings piles could result in localized but excessive erosion and sedimentation.

  9. Intradomiciliary behavior of Anopheles albimanus on the coastal plain of southern Mexico: implications for malaria control.

    PubMed

    Bown, D N; Rodriguez, M H; Arredondo-Jimenez, J I; Loyola, E G; Rodriguez, M C

    1993-09-01

    The postfeeding indoor resting behavior of Anopheles albimanus in experimental houses in southern México was investigated by using a mark-recapture procedure. The majority of mosquitoes rested inside houses after taking a blood meal indoors. There was a higher landing frequency on interior surfaces other than walls and roofs; however, mosquitoes rested for longer periods on these 2 surfaces. Successive landings on walls after short flights showed that mosquitoes gradually increased their mean landing height from 1.0 to 1.4 m. Similarly, mosquitoes resting at the base of inner roofs had a successive landing height range of about 0.5 m. Based on these observations and the potential for reduction of nearly 50% in the quantity of insecticide used and the time needed to apply it, village-scale studies involving the selective spraying of a 1-m-wide swath of insecticide on walls and on roofs are recommended in this area. PMID:8245943

  10. Biomonitoring of metal in children living in a mine tailings zone in Southern Mexico: A pilot study.

    PubMed

    Moreno, María Elena; Acosta-Saavedra, Leonor C; Meza-Figueroa, Diana; Vera, Eunice; Cebrian, Mariano E; Ostrosky-Wegman, Patricia; Calderon-Aranda, Emma S

    2010-07-01

    Accumulation of metals in soil represents a health risk for individuals living near mining areas, especially for children who have a higher susceptibility to metal related diseases. The Taxco mining district in Southern Mexico was one of the largest Mexican metal producers of silver and gold, among other metals. The aim of this pilot study was to evaluate metal exposure on children aged 6-11 years living in and around the Taxco mine tailings zone. Lead in blood (PbB) was measured by graphite furnace atomic absorption spectrophotometry (AAS). Urine arsenic (AsU) was measured by hydride generation AAS, urinary Hg (HgU) by flow injection cold vapor atomic absorption, and urinary concentration of other metals such as chromium (Cr), nickel (Ni), cadmium (Cd), barium (Ba), cobalt (Co), copper (Cu), zinc (Zn), manganese (Mn), molybdenum (Mo), strontium (Sr), and iron (Fe) were determined by inductively coupled plasma optical emission spectrometry. Fifty samples were analyzed for PbB, AsU, and HgU, and 35 samples for the other metals. The mean concentration+/-SD for each metal was: PbB, 9.4+/-3.3 microg/dL; NiU, 75.4+/-30.7 microg/L; BaU, 18.4+/-4.1 microg/L; MnU, 5.2+/-0.7 microg/L; CuU, 29.6+/-6.8 microg/L; AsU, 16.5+/-8.3 microg/L; HgU, 0.7+/-0.86 microg/L; CdU, 4.7+/-2.7 microg/L; CrU, 15.1+/-4.45 microg/L; CoU, 18.3+/-9.7 microg/L; SrU, 49.2+/-30.7 microg/L; ZnU, 628.4+/-438.9 microg/L; FeU, 30.5+/-17.7 microg/L; and MoU, 52.1+/-29.3 microg/L. Results of this exploratory study show that children residing in the mining area of Taxco were environmentally exposed to several metals and a high percentage of these children had levels of Ni, Ba, Mn, Cr, Co, Cd, As, Hg, and Pb above reference values. Thus, further studies are needed to assess the effects of simultaneous exposure to toxic metals in children residing in mining areas. PMID:20418157

  11. Determining Deep Basin Structure of the Hueco and southern Mesilla Bolsons, West Texas, Southern New Mexico and Northern Chihuahua Using Nonseismic Geophysical Techniques

    NASA Astrophysics Data System (ADS)

    Doser, D. I.; Avila, V.; Budhathoki, P.; Marrufo, S.; Montana, C. J.; Kaip, G.; Moncada, M.; Dena Ornelas, O.

    2012-12-01

    The Hueco and southern Mesilla bolsons are the primary groundwater source for much of the El Paso/Ciudad Juarez metropolitan region of over 1 million residents. The bolsons lie at the point where the strike of the southern Rio Grande rift changes from north-south to northwest-southeast, likely due to its interaction with pre-existing Mesozoic and Paleozoic structures. Tectonic activity continues with recent (< 750,000 years) movement along basin bounding and low level (M<4) seismicity. Over the past 4 years we have been using a conjunction of microgravity, magnetic, water well logs and electrical resistivity studies to image the complex structure of these basins within a heavily urbanized environment. These studies suggest the presence of several northwest-southeast striking cross faults within the southern Mesilla Bolson as well as an extensive subsurface andesite body related to the Cristo Rey laccolith. Intrabasin faults in the Hueco Bolson appear to cut the basin into at least 3 smaller subbasins and to control the boundary between fresh and saline water within the aquifer system beneath El Paso. We are also able to trace the East Franklins Mountain fault (last movement < 15,000 ya) at least 15 km south of the U.S.-Mexico border.

  12. Hydrogeochemical processes in ground water in a tropical karst environment of Southern Mexico

    NASA Astrophysics Data System (ADS)

    Mota, Sandra; Escolero, Oscar

    2015-04-01

    The karstic aquifers are of a great strategic importance in many regions along the world. These aquifers belong to carbonated formations which have been affected by fissuration and dissolution (karstification) processes. The specific organization of the flows in this type of aquifer determines the methodologies to be used in its exploration, although much still unknown about the processes occurring in tropical environments. This research has the overall aim to identify the hydrogeochemical processes affecting groundwater in the Rio Grande Basin of Comitan, in the state of Chiapas, Mexico. In the Rio Grande Basin are delimited 54 sub-basins having an area of 6126.67 km2. The geology of the area is characterized by lithology dominated by Mesozoic sedimentary rocks of the Lower Cretaceous series, clastic and carbonate rocks limestone-dolomite type are the oldest. Another lithological association present in the area is limestone-shale. Consistent with the previous unit, a deposit of sediments consisting of shale, sandstone and limestone occurs. On these previous formations layers of siltstone and sandstone with interbedded limestone were deposited. Deep and shallow wells used to supply water to the population, were used to establish a monitoring network aimed at identifying the types of groundwater and the processes occurring in the karstic aquifer. For the development of this work was carried out sampling September 2014, where 50 sites used for groundwater extraction were sampled, of which 20 are deep wells and 30 shallow wells. The physicochemical parameters were measured in the field, while the chemical constituents were analyzed in the laboratory. The data obtained were drawn diagrams to identify hydrogeochemical facies of groundwater sampled, and contour maps of chemical content and some measured parameters. Likewise, the field data have been interpreted with the help of hydrogeochemical models to identify the processes that may be changing water quality in the

  13. Examining ash fall sequences in calk-alkaline subduction related volcanism, southern New Mexico

    NASA Astrophysics Data System (ADS)

    Rentz, S. P.; Michelfelder, G.; Salings, E. E.; Sikes, E. R.

    2015-12-01

    The Mogollon-Datil volcanic field (MDVF) is a 40-20 ma cluster of caldera activity in southern New Mexico tied to the subduction of oceanic lithosphere beneath the North American continental plate. The calk-alkaline magmatism of the three calderas in this field (Mogollon, Bursum, and Gila Cliff Dwellings) produced several voluminous regionally dispersed ash flow tuffs. This study will specifically examine the volcanic rocks: Cooney Formation (a compositionally zoned rhyolitic to quartz latite ash flow tuff containing quartz>k-feldspar>plagioclase>biotite, and pumice and lithic fragments. Rb ranges from 213-317ppm, Sr from 104-108ppm, and 87Sr/86Srm from 0.71326-0.71534), Davis Canyon Tuff (a phenocryst poor, high-silica rhyolite ash flow tuff containing sanidine>quartz>sodic plagioclase. Rb ranges from 214-230ppm, Sr from 42.2-63.2ppm, and 87Sr/86Srm from 0.71383-0.71464), and the Shelley Peak Tuff (a compositionally zoned, crystal-rich rhyolite tuff containing sodic plagioclase>minor sanidine>biotite>cpx. Rb ranges from 154-213ppm, Sr from 105-245ppm, and 87Sr/86Srm from 0.70944-0.7112) to further elucidate their petrogenic origins, attempt to determine if they may be of the same magmatic source, and yield data that could help model processes that would generate magma of these particular compositions. This study will examine compositional variation between the Davis Canyon, Shelley Peak and Cooney Tuffs and help with understanding the magma plumbing system during each eruption. More specifically, we will evaluate possible crustal components of these units, along with looking for geochemical signatures of arc or rift related magmatism. We will compare previous geochronology results (K-Ar and U-Pb fission track) and whole rock major and trace element geochemistry to data obtained via 40Ar/39Ar and U/Pb dates and new whole rock Sr, Nd and Pb isotopic ratios.

  14. Mixed gas hydrate structures at the Chapopote Knoll, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Klapp, Stephan A.; Murshed, M. Mangir; Pape, Thomas; Klein, Helmut; Bohrmann, Gerhard; Brewer, Peter G.; Kuhs, Werner F.

    2010-10-01

    In underwater hydrocarbon seepage environments, gas hydrates are considered to play a significant role as shallow gas reservoirs and buffers for light hydrocarbon expulsion. Here we report on mixed hydrate structures from the Chapopote Knoll in the southern Gulf of Mexico and discuss several options on how a mixture of structure I (sI) and structure II (sII) gas hydrate may occur in nature. Locally resolving microscopic methods are needed to characterize the coexistence of different hydrate structures at geological hydrate deposits; we used Raman spectroscopy, X-ray diffraction, and gas chromatography for our investigations. Gas hydrates were found within the matrix and pores of the asphalts extruded at the seafloor. Two of the three hydrate pieces investigated comprised only sI, formed mostly from methane. In contrast, one piece comprised an intimate mixture of both sI and sII with sII representing ca. 25 wt.% and sI ca. 75 wt.% of the hydrate present. The two structures were closely associated within individual grain agglomerates. The crystallites of sII were significantly larger than of sI, suggesting differences in the nucleation density or different crystallite ages. The structural coexistence may be a result of one or more processes: i) de-mixing into two hydrate structures during the growth from the gas phase, which provides an additional degree of freedom for lowering the free energy in the system; ii) fractionated crystallization with a subsequently changing molecular composition; iii) crystallization from separated gas bubbles with different hydrocarbon compositions and water; and iv) partial transformation from sII to sI after hydrate nucleation, ceasing when a thermodynamically stable state was reached. The presented work will affect future assessments of natural hydrate deposits at thermogenic hydrocarbon systems, as it shows that both hydrate types I and II can be present at a certain geological site, and may provide a lingering strength to the system

  15. [Specific bacterial diversity in bats of different food guilds in Southern sierra Oaxaca, Mexico].

    PubMed

    Galicia, Mónica Marcela; Buenrostro, Alejandra; García, Jesús

    2014-12-01

    Specific bacterial diversity in bats of different food guilds in Southern sierra Oaxaca, Mexico. Bats have different ecologic roles in variable ecosystems that have been already described. They have been linked to several zoonoses, however little is known about the relationship between bat microbiota and their diet, and studies on the bacterial ecology of the microbiota in bats are limited. To contribute with the description of this important interaction between microbiota and host, the aim of this work was to characterize the composition and bacterial diversity in the oral and anal regions of 10 species of bats, in relation to food guild. For this monthly samplings were conducted using four mist nets (19:00-24:00h) from February to October 2012; nets were reviewed every 45 minutes. Each captured organism was sampled in the oral and anal cavities with sterile swabs; these were placed in pre-enrichment media and stored at 4°C. Bacterial samples were studied which through selective media, chromogenic and biochemical tests. We obtained samples from 502 frugivorous, 29 hematophagous and 11 nectivorous bats. We found a total of 26 bacterial species, with the predominant phylum Proteobacteria and the family Enterobacteriaceae. Statistically significant differences were observed between oral and anal microhabitats: frugivorous (t = -3.516, g.1 = 14.761, p = 0.003), hematophagous (t = -3.320, g.l = 19.262, p = 0.003), and nectivorous (t = -2.497, g.l = 11.933, p = 0.026), and in some guilds [frugivorous and nectivorous in the anal region (t = 2.274, g.l = 29.660, p = 0.030), hematophagous and nectivorous anal region (t = 2.077, g.l = 29.904, p = 0.049)]. It was also shown that there is bacteria specificity in some guilds such as nectivorous and frugivorous with Bacillus cereus, B. sp. X. sp., as well as, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, S. epidermis, Aeromonas hydrophyla in hematophagous. Bacterial presence can be explained by the type

  16. Palaeomagnetic study of the Xitle-Pedregal de San Angel lava flow, southern Basin of Mexico

    NASA Astrophysics Data System (ADS)

    Urrutia-Fucugauchi, J.

    1996-10-01

    A detailed study of the ˜ 2000 years old Xitle-Pedregal de San Angel volcanic field in the southern Basin of Mexico was undertaken to assess the reliability of the palaeomagnetic record as derived from fresh well-preserved and exposed lava flows. The Xitle vent is on the slope of the Ajusco volcano, which results in a topographic difference of over 800 m in less than 12 km of horizontal distance. Most sites present a mean direction, with a small within-site dispersion, around the dipolar direction for the locality, but some sites, particularly in the basin sector of flat relief away from the vent, show shallow inclinations. Anisotropy of magnetic susceptibility (AMS) shows normal 'flow' fabrics with horizontal foliation planes and small anisotropy degree. AMS lineations correlate with observed flow directions. The magnetic properties vary systematically across flow units, but directions do not show a consistent pattern. Secular variation effects do not apparently contribute to the shallow inclinations or directional scatter. Some lava structures like pressure crests and blocky fronts give shallow inclinations and scattered directions, respectively. The resulting overall mean direction is well defined and close to the dipolar direction ( B = 26, Dec = 359.8°, Inc = 32.8°, k = 167, α95 = 2.2°), but this excludes two apparent directional groups. The mean direction for one group, with B = 19, Dec = 359.0°, Inc = 35.1°, k = 247, α95 = 2.1°, may be the representative estimate for the field. Shallow inclinations are considered anomalous and associated to a characteristic specific to given sectors of lava flows. Palaeointensity determinations have been obtained for six samples from five sites by using the Thellier and Shaw methods. Results agree well with previous studies, however, the standard deviation calculated for the mean value remains high after incorporation of the new data. Mean palaeointensity based on five new determinations and eight early data is N

  17. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1987

    SciTech Connect

    Wiman, W.D.

    1988-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1987 showed significant increases in seismic acquisition in Belize, Bolivia, Brazil, Costa Rica, Guatemala, Mexico, Paraguay, and Peru, and a decrease in Chile and Venezuela. Exploratory drilling increased in most major producing countries but was accompanied by a decline in development drilling. Most of the increase could be attributed to private companies fulfilling obligations under risk contracts; however, state oil companies in Bolivia, Chile, and Colombia showed significant increased activity, with only Mexico showing a decrease. Colombia again had a dramatic increase in production (29% from 1986). Noteworthy discoveries were made in Bolivia (Villamontes-1); Brazil, in the Solimoes basin (1-RUC-1-AM); Chile (Rio Honda-1); Colombia, in the Llanos basin (Austral-1, La Reforma-1, Libertad Norte-1, Cravo Este-1, and Cano Yarumal-1), in the Upper Magdalena basin (Toldado-1 and Los Mangos-1); Ecuador (Frontera-1, a joint-exploration venture with Colombia); Mexico, in the Chiapas-Tabasco region (Guacho-1 and Iridi-1), in the Frontera Norte area (Huatempo-1); Peru, in the Madre de Dios basin (Armihuari-4X); Trinidad (West East Queen's Beach-1); and Venezuela (Musipan-1X). Brazil's upper Amazon (Solimoes basin) discovery, Colombia's Upper Magdalena basin discoveries Toldado-1 and Los Mangos-1, Mexico's Chiapas-Tabasco discoveries, Peru's confirmation of the giant Cashiriari discovery of 1986, and Venezuela's success in Monagas state were the highlights of 1987. 5 figs., 8 tabs.

  18. Stratigraphy, geochemistry and tectonic significance of the Oligocene magmatic rocks of western Oaxaca, southern Mexico

    USGS Publications Warehouse

    Martiny, B.; Martinez-Serrano, R. G.; Moran-Zenteno, D. J.; MacIas-Romo, C.; Ayuso, R.A.

    2000-01-01

    the volcanic rocks, from 0.7042 to 0.7046 and 0 +2.6. The range of these isotope ratios and those reported for the basement rocks in this region suggest a relatively low degree of old crustal involvement for most of the studied rocks. The Pb isotopic compositions of the Tertiary magmatic rocks also show a narrow range [(206Pb/204Pb) = 18.67-18.75; (207Pb/204Pb) = 15.59-15.62; (208Pb/204Pb) = 38.44-38.59], suggesting a similar source region for the volcanic and plutonic rocks. Trace elements and isotopic compositions suggest a mantle source in the subcontinental lithosphere that has been enriched by a subduction component. General tectonic features in this region indicate a more active rate of transtensional deformation for the inland volcanic region than along the coastal margin during the main events of Oligocene magmatism. The lower degree of differentiation of the inland volcanic sequences, particularly the upper unit of the northern sector, compared to the plutons of the coastal margin, suggests that the differentiation of the Tertiary magmas in southern Mexico was controlled to a great extent by the characteristics of the different strain domains. (C) 2000 Elsevier Science B.V. All rights reserved.

  19. Eruptive Style and Geochronology of the Initial Fases of Monogenetic Vulcanism of Southern Basis of Mexico

    NASA Astrophysics Data System (ADS)

    Jaimes, M. D.; Martin, A.; Layer, P. W.

    2013-05-01

    Monogenetic vulcanism in the central part of Mexico includes the Chichinautzin Monogenetic Volcanic Field, located at the front of the Transmexican Volcanic Belt (TMVB), 300 km from the Mesoamerican trench. At least 220 volcanoes formed during the Pleistocene and Holocene. Most are scoria cones with associated lava flows, small shield volcanoes and lava domes; and cover an área of 2400 km2 (Martin Del Pozzo, 1982; Wallace and Carmichael, 1999; Velasco-Tapia and Verma, 2001; Velasco-Tapia, 2003). Previous studies in the area (paleomagnetic, geomorphologic, vulcanologic and radiometric) indicate that volcanism is less than 0.79 Ma (Bloomfield, 1973; Mooser et al., 1974; Herrero and Pal, 1978; Martin Del Pozzo et al., 1997; Siebe et al., 2004a). Our field studies include mapping and sampling of 50 lava flows associated with scoria cones, phreatomagmatic structures (2), lava flows without cones (2) and lava domes (5). Geomorphologic analyses, whole rock chemical analyse (FRX), petrographic and geochronologic (Ar-Ar) were carried out. We identified three zones with different eruptive styles: strombolian and violent strombolian to the north and south; and phreatomagmatic style only in the north. Samples are basaltic andesites to dacites. Geochronologic data is consistent with some of the relative ages according to the geomorphologic data and corresponds to three age groups.

  20. Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru

    NASA Astrophysics Data System (ADS)

    Brizuela, B.; Armigliato, A.; Tinti, S.

    2014-07-01

    Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that occurred on 2 September 1992 off Nicaragua, with run-up measured in the range of 5-10 m in several places along the Nicaraguan coast. The aim of this paper is to assess the tsunami hazard on the Pacific coast of this extended region, and to this purpose a hybrid probabilistic-deterministic analysis is performed, that is adequate for tsunamis generated by earthquakes. More specifically, the probabilistic approach is used to compute the Gutenberg-Richter coefficients of the main seismic tsunamigenic zones of the area and to estimate the annual rate of occurrence of tsunamigenic earthquakes and their corresponding return period. The output of the probabilistic part of the method is taken as input by the deterministic part, which is applied to calculate the tsunami run-up distribution along the coast.

  1. Estimation of the time of seroconversion to the New Jersey serotype of vesicular stomatitis virus in sentinel cattle of dairy herds located at high and low elevations in southern Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To estimate time to seroconversion to vesicular stomatitis 1 New Jersey virus (VSNJV) in sentinel cattle in southern Mexico, ninety-two sentinel cattle in four free-ranging dairy herds at high- (=500 mts) and low-elevation (<500 mts) locations in southern Mexico were studied. A prospective cohort s...

  2. SEDIMENT HABITAT ASSESSMENT FOR TARGETED NEAR-COASTAL AREAS OF THE GULF OF MEXICO: A SUMMARY

    EPA Science Inventory

    Lewis, Michael A. In press. Sediment Habitat Assessment for Targeted Near-Coastal Areas of the Gulf of Mexico: A Summary. In: Estuarine Indicators Workshop Proceedings. CRC Press, Boca Raton, FL. 25 p. (ERL,GB 1201).

    Sediment chemical and biological quality is summarized ...

  3. An Ethnographic Study of Special Education Services in a Rural Area of Mexico.

    ERIC Educational Resources Information Center

    Argus-Calvo, Beverley; And Others

    1996-01-01

    Overviews the current status of special education programs in Mexico in general and in Ciudad Juarez (Chihuahua) and surrounding rural areas. Two special education administrators employed in the Ciudad Juarez school system discuss problems associated with teacher training and lack of administrative support, and the importance of parental and…

  4. EVALUATION OF ENVIRONMENTAL HAZARD ASSESSMENT PROCEDURES FOR NEAR-COASTAL AREAS OF THE GULF OF MEXICO

    EPA Science Inventory

    Lewis, Michael A. In press. Evaluation of Environmental Hazard Assessment Procedures for Near-Coastal Areas of the Gulf of Mexico (Abstract). To be presented at the Annual Meeting of the the Australasian Society of Ecotoxicology, July 2004, Gold Coast, Australia. 1 p. (ERL,GB R98...

  5. TREATED WASTEWATER AS A SOURCE OF SEDIMENT CONTAMINATION IN GULF OF MEXICO NEAR-COASTAL AREAS

    EPA Science Inventory

    The primary objective of this baseline survey was to provide some needed perspective on the magnitude of sediment contamination associated with wastewater outfalls discharged to Gulf of Mexico near-coastal areas. The chemical quality and toxicities of whole sediments and pore wa...

  6. 33 CFR 166.200 - Shipping safety fairways and anchorage areas, Gulf of Mexico.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Navigation or danger markings must be installed as required by 33 CFR Subchapter C. (c) Special Conditions...: For Federal Register citations affecting § 166.200, see the List of CFR Sections Affected, which... anchorage areas, Gulf of Mexico. 166.200 Section 166.200 Navigation and Navigable Waters COAST...

  7. The Ambrosia Lake project archaeological investigations of three small sites associated with the southern Chacoan outlier of Kin Nizhoni, McKinley County, New Mexico

    SciTech Connect

    Cullington, B.J.; Hammack, L.C.; Baugh, T.G.

    1990-03-15

    During the fall of 1987, Complete Archaeological Service Associates conducted mitigative excavations at three sites (LA50363, LA50364, and LA50371) in McKinley County, New Mexico. These sites are adjacent to the Phillips/United Nuclear Inactive Uranium Mill and Tailings site at Ambrosia Lake, New Mexico. The primary deposition at each of these sites appears to be related to a Pueblo II or Bonito Phase occupation. Temporal placement is based primarily on the cross dating of ceramics and archaeomagnetic determinations when possible. No tree-ring or radiocarbon samples are available from these sites. These Ambrosia Lake sites indicate that this area was occupied primarily by Pueblo II people who may have had close social, economic, and ceremonial ties with the people living at the nuclear community of Lower Nizhoni about 3 km south-southeast. The later component at LA50364 indicates a Pueblo III occupation by people who may have had similar ties to the people of the Kin Nizhoni nuclear community. The Ambrosia Lake sites, then, provide important information on the structure of subnuclear communities within the southern Chaco periphery.

  8. Atlantic Ocean modulated hydroclimate of the subtropical northeastern Mexico since the last glacial maximum and comparison with the southern US

    NASA Astrophysics Data System (ADS)

    Roy, Priyadarsi D.; Rivero-Navarrete, Axel; Sánchez-Zavala, José L.; Beramendi-Orosco, Laura E.; Muthu-Sankar, Gowrappan; Lozano-Santacruz, Rufino

    2016-01-01

    Proxy records generated from chemical composition and radiocarbon dating of a sediment sequence collected from the El Potosi Basin provide information about variable hydroclimate of the subtropical northeastern Mexico since the last glacial maximum (LGM). Minimal amounts of runoff and more carbonate deposition during >19 ka represent the LGM. The deglaciation was wetter compared to the LGM and enhanced runoff during ˜ 19- 12 ka transported more Ti-bearing clastics from a relatively humid watershed. Over the deglaciation, the basin received more runoff during the Bølling-Allerød compared to the Heinrich Stadial 1 and Younger Dryas. Reduction in the amount of runoff during ˜ 10- 1 ka and deposition of unweathered Si-bearing clastics during ˜ 4- 1 ka suggest that the Holocene was drier compared to the deglaciation. Hydroclimates of the northeastern Mexico and southern US were synchronous during the LGM as well as deglaciation. Change from the drier LGM to wetter Bølling-Allerød occurred as the Gulf of Mexico became warmer and the region received more summer precipitation. However, the dissimilarities observed in regional hydroclimates of the Holocene need further evaluation.

  9. COLUMBINE-HONDO WILDERNESS STUDY AREA AND WHEELER PEAK WILDERNESS, NEW MEXICO.

    USGS Publications Warehouse

    Ludington, Steve; Brown, S. Don

    1984-01-01

    The Columbine-Hondo Wilderness Study Area and the Wheeler Peak Wilderness, near Taos, New Mexico, were studied. Two areas within the study area and wilderness have substantiated mineral-resource potential for molybdenum and are surrounded by an area of probable molybdenum potential. A small area on the north side of the Columbine-Hondo Wilderness Study Area also has probable molybdenum potential; this area is peripheral to the Red River mining area, which includes the Questa mine. Two other areas within the study area and wilderness have probable mineral-resource potential for copper, lead, and zinc, and four areas have probable mineral-resource potential for gold and silver, as well as base metals.

  10. Development of a high-resolution binational vegetation map of the Santa Cruz River riparian corridor and surrounding watershed, southern Arizona and northern Sonora, Mexico

    USGS Publications Warehouse

    Wallace, Cynthia S.A.; Villarreal, Miguel L.; Norman, Laura M.

    2011-01-01

    This report summarizes the development of a binational vegetation map developed for the Santa Cruz Watershed, which straddles the southern border of Arizona and the northern border of Sonora, Mexico. The map was created as an environmental input to the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM) that is being created by the U.S. Geological Survey for the watershed. The SCWEPM is a map-based multicriteria evaluation tool that allows stakeholders to explore tradeoffs between valued ecosystem services at multiple scales within a participatory decision-making process. Maps related to vegetation type and are needed for use in modeling wildlife habitat and other ecosystem services. Although detailed vegetation maps existed for the U.S. side of the border, there was a lack of consistent data for the Santa Cruz Watershed in Mexico. We produced a binational vegetation classification of the Santa Cruz River riparian habitat and watershed vegetation based on NatureServe Terrestrial Ecological Systems (TES) units using Classification And Regression Tree (CART) modeling. Environmental layers used as predictor data were derived from a seasonal set of Landsat Thematic Mapper (TM) images (spring, summer, and fall) and from a 30-meter digital-elevation-model (DEM) grid. Because both sources of environmental data are seamless across the international border, they are particularly suited to this binational modeling effort. Training data were compiled from existing field data for the riparian corridor and data collected by the NM-GAP (New Mexico Gap Analysis Project) team for the original Southwest Regional Gap Analysis Project (SWReGAP) modeling effort. Additional training data were collected from core areas of the SWReGAP classification itself, allowing the extrapolation of the SWReGAP mapping into the Mexican portion of the watershed without collecting additional training data.

  11. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1983

    SciTech Connect

    Tappmeyer, D.M.

    1984-10-01

    Petroleum exploration in the region was generally less in 1983 than in 1982. Brazil, Colombia, Ecuador, and Barbados increased crude production, whereas Argentina, Bolivia, Brazil, Colombia, Ecuador, Mexico, and Trinidad-Tobago reported increases in gas production. Although drilling activities remained low compared to past years, significant oil discoveries were reported in Colombia, Mexico, and Brazil. In Colombia, Cano Limon field is reported to be the largest field found in the Llanos region. In Brazil, important oil discoveries were made offshore in the Para, Potiquas, and Ampos basins. In Mexico, discoveries were reported in the Cerro Azul, Poza Rica (Chicontepec, Villahermosa, and Tabasco) areas onshore and in the Bay of Campeche offshore. In Argentina, discoveries were made in the San Jorge basin and the Noreste Tarija basin. 10 figures, 11 tables.

  12. Southern Sclerotium blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sclerotium rolfsii attacks a wide range of plants throughout the world. It is most severe in tropical and subtropical areas. Southern Sclerotium blight is of major concern in the eastern, southeastern, and southwestern United States and in Mexico. Although severe losses are reported annually in pe...

  13. Preliminary study of the acid deposition in the Tijuana Area (Mexico)

    SciTech Connect

    Bravo, H.; Sosa, R.; Torres, R. )

    1988-01-01

    Transboundary air pollution is of widespread international concern. Tijuana, Mexico, and San Diego, California, form one of the fastest growing border communities in the world. Projections place the current population of three million residents at nearly five million by the year 2000. Although the two cities are divided by an international border they share a common air base. Tijuana and southern portions of San Diego County are particularly affected by the exchange of air flow through the Tijuana River Canyon. The development of an air pollution acid rain monitoring and sampling program across the border, particularly in Tijuana is imperative because of a planned new Tijuana industrial city, large numbers of existing industries without adequate emission controls, and thousands of vehicles generated pollutants on both sides of the border. The first steps toward an acid rain study along the mexican border began in 1985, with a project between the National Council of Science and Technology - (CONACYT) and the Center of the Atmospheric Sciences of the University of Mexico (CCA, UNAM). The goal of this project is to obtain acid rain data from five sites along the border. One of these sites is Tijuana, B.C., Mexico. The data obtained are reported in the paper.

  14. DISSOLVED METHANE IN THE SILLS AREA, GULF OF CALIFORNIA, MEXICO

    EPA Science Inventory

    The northern part of the Gulf of California is physically separated from the rest of the Gulf by a series of sills and islands. Its waters are highly productive as several water masses interact with each other at the sills. One of the characteristics in the area is the presence o...

  15. Mexico.

    PubMed

    1993-01-01

    The background notes on Mexico provide text and recent statistical information on the geography, population, government, economy, and foreign relations, specifically the North American Free Trade Agreement with US. The 1992 population is estimated at 89 million of which 60% are mestizo (Indian-Spanish), 30% are American Indian, 9% are Caucasian, and 1% are other. 90% are Roman Catholic. There are 8 years of compulsory education. Infant mortality is 30/1000 live births. Life expectancy for males is 68 years and 76 years for females. The labor force is comprised of 30% in services, 24% in agriculture and fishing, 19% in manufacturing, 13% in commerce, 7% in construction, 4% in transportation and communication, and .4% in mining. There are 31 states and a federal district. Gross domestic product (GDP) per capita was $3200 in 1991. Military expenditures were .5% of GDP in 1991. The average inflation rate is 19%. Mexico City with 20 million is the largest urban center in the world. In recent years, the economy has been restructured with market oriented reforms; the result has been a growth of GDP of 3.6% in 1991 from 2% in 1987. Dependence on oil exports has decreased. There has been privatization and deregulation of state-owned companies. Subsidies to inefficient companies have been stopped. Tariff rates were reduced. The financial debt has been reduced and turned into a surplus of .8% in 1992. Mexico's foreign debt has been reduced from its high in 1987 of $107 billion. Agricultural reforms have been ongoing for 50 years. Land was redistributed, but standards of living and productivity have improved only slightly. Rural land tenure regulations have been changed, and other economic reforms are expected. Mexico engages in ad hoc international groups and is selective about membership in international organizations. PMID:12178052

  16. Nereis alacranensis, a new species of polychaete (Annelida, Nereididae) from Alacranes Reef, southern Gulf of Mexico, with a key to Nereis from the Grand Caribbean.

    PubMed

    Ramírez Hernández, Adriana; Hernández-Alcántara, Pablo; Solís-Weiss, Vivianne

    2015-01-01

    A new species of polychaete, Nereis alacranensis n. sp., was found in dead coral rocks in the intertidal zone of Alacranes reef, southern Gulf of Mexico. N. alacranensis n. sp. can be included in a group of nereidids characterized by the absence of paragnaths in areas I and V of the pharynx, the presence of cones in a single row or absent in areas VII-VIII, and short blades in notopodial homogomph falcigers. The new species can be separated from the other species of the group by the presence of 3-7 cones in area VI and 7 cones arranged in a row in areas VII-VIII, finely dentate blades in notopodial homogomph falcigers, but most of all, by the presence of an unusual brown coarse arc shaped plate on the external ventral region of the peristomium. This structure has not yet been reported, at least in this genus. A taxonomic key of the species of Nereis recorded from the Grand Caribbean region is included. PMID:26623850

  17. Active Extensional Faulting at the Southern Half-Graben Belt of the Tepic-Zacoalco Rift, Western Mexico

    NASA Astrophysics Data System (ADS)

    Rosas-Elguera, J.; Ferrari, L.; Delgado, M.; Uribe, A.; Valdivia, L.; Castillo, R.

    2003-12-01

    In the past decade much debate has centered upon the kinematics and the mechanism of continental deformation in western Mexico and the motion of the Jalisco block relative to North America. Two distinct models have been proposed. The first one suggest a NW-motion of the Jalisco block that would implies a right-lateral faulting along the Tepic-Zacoalco rift (TZR). More recently others authors have documented a N-NE extensional tectonics active since late Miocene and suggested that the continental boundaries of the Jalisco block, are older structures reactivated by plate boundary forces. Studies on the crustal seismicity and the kinematics of Quaternary faults provide another constraint on the direction of motion between the Jalisco block and North America. On November 4, 5, 6, and 7, 1995, one month after the October 09, 1995, Manzanillo earthquake (Mw = 8.0), a swarm of small events was felt in the Amatlan de Ca¤as half-graben and recorded by the regional seismic network of Comision Federal de Electricidad. The coda magnitude of the largest event was Mc = 2.5-3.6 and the events were located depth ranging from 6 to 10 km. This seismic activity provoked that people from Pie de la Cuesta and Yerbabuena villages were evacuated. After that a seismic station equipped with an analogic seismograph MEQ-800 at Pie de la Cuesta was installed for three months. During the same time, October, 1995, some houses distributed along a WNW trend in Ameca city underwent severe damages, they are. The digital elevations model of the Ameca city suggest that several structures tectonics are shorter than 2 km are present in the area. The present direction of motion of the Rivera plate relative to North America plate along Middle America Trench has been estimated between N19° E to N48° E (e.g. Bandy et al., 1996). During the October 09, 1995, subduction-related earthquake (Mw = 8.0) a GPS network recorded a SW motion of the Jalisco block which could be associated to an elastic deformation

  18. Palaeomagnetism of the upper volcanic supergroup, southern part of the Sierra Madre Occidental, Mexico

    NASA Astrophysics Data System (ADS)

    Perrin, M.; Alva-Valdivia, L. M.; Lopez-Martinez, M.; Rosas-Elguera, J.; Benammi, M.; Gonzalez-Rangel, J. A.; Camps, P.

    2013-06-01

    Ash flow tuffs, or ignimbrites have been recently proposed to be a good material for palaeointensity determination. In this paper, we present a multidisciplinary study, combining geochronology, petrology, rock magnetism and palaeomagnetism, carried out on Oligocene to Early Miocene ignimbrites and related flows from the southern part of the Sierra Madre Occidental. Two new 40Ar/39Ar ages were determined for ignimbrites; 20.4 ± 0.2 Ma (the youngest age obtained so far in this area) and 29.2 ± 0.5 Ma. Density measurements, as a proxy for welding, proved to be extremely useful to estimate the emplacement temperature and the origin of the magnetizations carried by the ignimbrites. After alternating field and thermal demagnetizations, the mean palaeomagnetic pole (Lat = 66.8°N; Long = 180.5°E; Kappa = 142; A95 = 6.3°), calculated for the period 28-31 Ma, is in close agreement with our only Miocene determination. Comparison with the North America Synthetic Apparent Polar Path indicates a net counter-clockwise vertical axis rotation of about 10 ± 4° compared to stable North America, which occurred likely during the last extensional episode in the Late Miocene (ca. 12-9 Ma). Palaeointensity estimates, obtained with the Thellier-Coe method, are mainly questionable and should not be used for global interpretation. Therefore, these ignimbrites are not a viable material for reliable palaeointensity determinations.

  19. Current Knowledge of Leishmania Vectors in Mexico: How Geographic Distributions of Species Relate to Transmission Areas

    PubMed Central

    González, Camila; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; Becker-Fauser, Ingeborg; Martínez-Meyer, Enrique; Peterson, A. Townsend; Sánchez-Cordero, Víctor

    2011-01-01

    Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological niches of nine sand fly species and projected niches to estimate potential distributions by using known occurrences, environmental coverages, and the algorithms GARP and Maxent. All vector species were distributed in areas with known recurrent transmission, except for Lu. diabolica, which appeared to be related only to areas of occasional transmission in northern Mexico. The distribution of Lu. o. olmeca does not overlap with all reported cutaneous leishmaniasis cases, suggesting that Lu. cruciata and Lu. shannoni are likely also involved as primary vectors in those areas. Our study provides useful information of potential risk areas of leishmaniasis transmission in Mexico. PMID:22049037

  20. 33 CFR 334.290 - Elizabeth River, Southern Branch, Va., naval restricted areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Va., naval restricted areas. 334.290 Section 334.290 Navigation and Navigable Waters CORPS OF....290 Elizabeth River, Southern Branch, Va., naval restricted areas. (a) The areas—(1) St. Helena Annex Area. Beginning at a point at St. Helena Annex of the Norfolk Naval Shipyard, on the eastern shore...

  1. 33 CFR 334.290 - Elizabeth River, Southern Branch, Va., naval restricted areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Va., naval restricted areas. 334.290 Section 334.290 Navigation and Navigable Waters CORPS OF....290 Elizabeth River, Southern Branch, Va., naval restricted areas. (a) The areas—(1) St. Helena Annex Area. Beginning at a point at St. Helena Annex of the Norfolk Naval Shipyard, on the eastern shore...

  2. Silvopastoral systems of the Chol Mayan ethnic group in southern Mexico: Strategies with a traditional basis.

    PubMed

    Pignataro, Ana Genoveva; Levy Tacher, Samuel Israel; Aguirre Rivera, Juan Rogelio; Nahed Toral, José; González Espinosa, Mario; Rendón Carmona, Nelson

    2016-10-01

    Silvopastoral systems combine trees and/or shrubs with grazing cattle. In the municipality of Salto de Agua, Chiapas, Mexico, some indigenous communities have developed silvopastoral systems based on their traditional knowledge regarding use of local natural resources. Through analysis of classification based on the composition of tree vegetation, two groups of grazing units were identified in the study area. Different attributes of tree and herbaceous vegetation, as well as of agricultural management and production, were compared between the two groups. Results indicate that at least two strategies of silvopastoral management exist. The first - LTD - is characterized by an average density of 22 adult trees ha(-1) in grazing units with an average surface area of 22.4 ha. The second - HTD - has an average of 54.4 trees ha(-1) in grazing units with an average surface area of 12.2 ha. Average richness per grazing unit for the LTD strategy was 7.2 species, and for HTD strategy it was 12.7 species. Average basal area for LTD was 1.7 m2 ha(-1), and for HTD 3.8 m2 ha(-1). Finally, the average level of fixed carbon for LTD was 2.12 mg ha(-1), and for HTD 4.89 mg ha(-1). For all variables, there was a significant difference between the two strategies. In addition, both strategies differ in prairie management. In the HTD strategy, growers spare their preferred spontaneously growing tree species by clearing around them. Many of these species, particularly those harvested for timber, belong to the original vegetation. In these prairies, average coverage of native grasses (60.8 ± 7.85) was significantly greater than in the LTD strategy (38.4 ± 11.32), and neither fertilizers nor fire are used to maintain or improve the pastures; by contrast, in HTD prairies, introduced grasses, principally Cynodon plectostachyus, have a higher average coverage (43.4 ± 13.75) than in the LTD prairies (17.08 ± 9.02). Regardless of the differences in composition of tree and

  3. An Exploratory Study of Internal Migration and Substance Use Among an Indigenous Community in Southern Mexico.

    PubMed

    Pinedo, Miguel; Sim, D Eastern Kang; Giacinto, Rebeca Espinoza; Luisa Zuñiga, Maria

    2016-01-01

    The primary aim of this study was to explore the association between internal migration experience within Mexico and lifetime substance use among a sample of 442 indigenous persons from Yucatan, Mexico. Adjusting for potential confounding, correlates of lifetime substance use were assessed among participants with and without internal migration experience. Internal migration to a tourist destination was independently associated with higher odds (adjusted odds ratio: 2.1; 95% confidence interval: 1.3-3.4) of reporting lifetime substance use. Findings suggest that environmental contexts of internal migration may be of importance in shaping vulnerability to substance use. PMID:26605952

  4. 75 FR 69122 - Outer Continental Shelf (OCS), Western and Central Planning Areas, Gulf of Mexico (GOM) Oil and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-10

    ... Central Planning Areas, Gulf of Mexico (GOM) Oil and Gas Lease Sales for the 2007-2012 5-Year OCS Program...) Lease Sale 222 in the 2007-2012 5-Year OCS Program. The proposed sales are in the Gulf of Mexico's WPA... 2012, before the end of the 2007-2012 5-Year OCS Program. A SEIS is deemed appropriate to...

  5. 78 FR 14116 - Gulf of Mexico (GOM), Outer Continental Shelf (OCS), Eastern Planning Area (EPA) Lease Sale 225...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-04

    ... Bureau of Ocean Energy Management Gulf of Mexico (GOM), Outer Continental Shelf (OCS), Eastern Planning Area (EPA) Lease Sale 225 and 226, Oil and Gas Lease Sales AGENCY: Bureau of Ocean Energy Management... Bureau of Ocean Energy Management, Gulf of Mexico OCS Region, Public Information Office (GM 250I),...

  6. Four new species of Cymatodera Gray from central and southern Mexico (Coleoptera, Cleridae, Tillinae)

    PubMed Central

    Burke, Alan F.; Rifkind, Jacques; Zolnerowich, Gregory

    2015-01-01

    Abstract Four new species of Cymatodera are described from Mexico: Cymatodera tortuosa Burke & Rifkind, sp. n. from Hidalgo and Tamaulipas; Cymatodera ortegae Burke, sp. n. from Colima, Jalisco and Michoacan; Cymatodera gerstmeieri Burke & Rifkind, sp. n. from Chiapas; and Cymatodera mixteca Burke & Rifkind, sp. n. from Puebla and Guerrero. Male genitalia and other characters of taxonomic value are illustrated. PMID:26257571

  7. A Community of Practice among Educators, Researchers and Scientists for Improving Science Teaching in Southern Mexico

    ERIC Educational Resources Information Center

    Cisneros-Cohernour, Edith J.; Lopez-Avila, Maria T.; Barrera-Bustillos, Maria E.

    2007-01-01

    This paper presents findings of a project aimed to improve the quality of science education in Southeast Mexico by the creation of a community of practice among scientists, researchers and teachers, involved in the design, implementation and evaluation of a professional development program for mathematics, chemistry, biology and physics secondary…

  8. Detrital provenance of the Grenvillian Oaxacan Complex, southern Mexico: a zircon perspective

    NASA Astrophysics Data System (ADS)

    Solari, Luigi A.; Ortega-Gutiérrez, Fernando; Elías-Herrera, Mariano; Ortega-Obregón, Carlos; Macías-Romo, Consuelo; Reyes-Salas, Margarita

    2014-07-01

    The Oaxacan Complex is the largest exposure of Grenvillian-age rocks in Mexico, constituting the backbone of the Oaxaquia microcontinent. Whereas the main rock-forming events were previously established at 1,150-1,200 Ma (charnockite-syenite-gabbros), 1,020 Ma (AMCG suite), 990 Ma (granulite-facies metamorphism), and ca. 970 Ma post-tectonic pegmatites, no data are yet available to establish provenance links with other Grenville-age terranes. In this work, we studied detrital zircons belonging to 12 samples, all metamorphosed under granulite facies but variably affected by retrogression. Laser ablation inductively coupled plasma mass spectrometry U-Pb geochronology was employed on selected zircons to determine their crystallization age and geochemistry. The results of the analysis of about 100 crystals per sample show that the studied zircons range between ca. 940 and 1,400 Ma, with only three samples having zircons between 1,400 and 1,600 Ma, and only one showing older zircons up to ca. 1,775 Ma. Whereas some of the slightly discordant (1-5 %) zircons in several samples show ages younger than the granulite metamorphism (probably as a result of Pb loss), and thus a disturbed geochemical pattern (abnormal enrichment in LREE, decreasing HREE), a few metamorphic zircons show flat and depleted HREE patterns, contrasting with the igneous pattern of older zircons (positive Ce anomaly, negative Eu anomaly, enriched HREE pattern). The main distributions observed using the kernel density estimator diagrams fall in the range 975-995 Ma (six samples), 1,100 Ma (four samples) and 1,120-1,170 Ma (six samples). Only the southernmost sample shows a marked peak at ca. 1,400 Ma. The application of the Kolmogorov-Smirnov (K-S) statistical test to the studied samples and particularly the comparison of obtained P values yield interesting similarities. Overall, two sample groups show internal similarities, i.e., they may belong to the same source area, whereas only one sample is

  9. [Acceptability of medroxyprogesterone acetate in rural areas of Mexico].

    PubMed

    Velasco Murillo, V; Cervantes Bustamante, A; Correu Azcona, S; García López, E

    1981-03-01

    361 retrospective surveys were carried out among users of medroxyprogesterone acetate (MPA) given in a trimestral regimen of 150 mg/dose in rural areas of 3 Mexican states. Gynecology-obstetric antecedents, previous experience with oral contraceptives (OCs), effects of injections on the menstrual cycle, causes of method suspension, and opinion concerning administration of medication were analyzed. 78.6% of the patients were multigravidae with 4 or more pregnancies; 39.1% were former users of OCs, and 23.4% had stopped taking them because of side effects. The side effects of MPA on the menstrual cycle were: amenorrhea (19.8%); hemorrhage/cycle of 10-30 days in 14.7%; and hemorrhage/cycle of 30 or more days in 11.6%. Only 14.7% of users stopped the injections and of these, 80.3% did so due to menstrual cycle disorders. 99.7% of the users thought the method was comfortable as a family planning procedure. (author's) PMID:6459270

  10. Temperature anomaly in the volcano Popocatepetl area, Mexico

    NASA Astrophysics Data System (ADS)

    Kotsarenko, A.; Grimalsky, V.; Yutsis, V.; Lavana Cardenas, J. C.; Chavez, O.; Sojo-Amezquita, A., Sr.

    2014-12-01

    Anomaly changes in the diurnal behavior of the temperature measured in the near-surface soil (30-40 cm) in Tlamacas monitoring site, volcano Popocatepetl area, are presented. Results of statistical analysis show 2 essential changes for the temperature characteristics observed during 2007-2009 and 2013-2014 monitoring periods: 1.) Minimum and maximum of the diurnal temperature have moved approximately to the 14 LT and to midnight, 24 LT, respectively (Fig 1., c). Under the "normal" condition, the absolute minimum of daily temperature is observed during sunrise (about 7 LT) for the atmosphere measurements and with certain time lag (about 9 LT, Fig.1,b) for the measurements in soil (depending on the depth), and absolute temperature maximum is observed in time when Solar radiation is not enough to provide heating of the atmosphere (about 16 LT) or the Earth surface (about 17 LT, Fig.1,b). Dispersion of the residual temperature (24-hours running trend of the temperature substituted) is 6 times lower for the period of monitoring 2013-2014 (Fig.1, g and h) in comparison with a period 2007-2009 (Fig.1, e and f). In other words, a temperature variation between the maximum and minimum during the day became 6 times lower that it was before.

  11. Potash ore reserves in the proposed Waste Isolation Pilot Plant area, Eddy County, southeastern New Mexico

    USGS Publications Warehouse

    John, Charles B.; Cheeseman, R.J.; Lorenz, J.C.; Millgate, M.L.

    1978-01-01

    The proposed Waste Isolation Pilot Plant (WIPP) area includes about 18,960 acres in Tps. 22 and 23 S., Rs. 30 and 31 E., New Mexico Principal Meridian, Eddy County, southeastern New Mexico. It is located within the Carlsbad Mining District about 25 miles east of Carlsbad. The WIPP area is immediately south of the Capitan Limestone subcrop, which formed the northern margin of the Delaware basin in Permian time. During Late Permian (Ochoan) time, gypsum, anhydrite, and halite were deposited in the seas of the Delaware basin to form the Castile Formation. These deposits have a maximum thickness of about 2,000 feet and grade upward into the more argillaceous beds of the Salado Formation. The Salado Formation contains abundant sulfate minerals, notably anhydrite and polyhalite. The potash ore minerals, langbeinite and sylvite, occur in the upper part of the Salado Formation in the McNutt potash zone, a local name applied to a potassium-rich zone.

  12. Geothermal data for 95 thermal and nonthermal waters of the Valles Caldera - southern Jemez Mountains region, New Mexico

    SciTech Connect

    Goff, F.; McCormick, Trujillo, P.E. Jr.; Counce, D.; Grigsby, C.O.

    1982-05-01

    Field, chemical, and isotopic data for 95 thermal and nonthermal waters of the southern Jemez Mountains, New Mexico are presented. This region includes all thermal and mineral waters associated with Valles Caldera and many of those located near the Nacimiento Uplift, near San Ysidro. Waters of the region can be categorized into five general types: (1) surface and near surface meteoric waters; (2) acid-sulfate waters (Valles Caldera); (3) thermal meteoric waters (Valles Caldera); (4) deep geothermal and derivative waters (Valles Caldera); and (5) mineralized waters near San Ysidro. Some waters display chemical and isotopic characteristics intermediate between the types listed. The object of the data is to help interpret geothermal potential of the Jemez Mountains region and to provide background data for investigating problems in hydrology, structural geology, hydrothermal alterations, and hydrothermal solution chemistry.

  13. Small scale field trials of Bacillus sphaericus (strain 2362) against anopheline and culicine mosquito larvae in southern Mexico.

    PubMed

    Arredondo-Jiménez, J I; López, T; Rodríguez, M H; Bown, D N

    1990-06-01

    Experimental breeding sites simulating natural conditions were used to evaluate the efficacy of 2 formulations of Bacillus sphaericus (strain 2362) against Anopheles albimanus and culicine (mostly Culex coronator and Cx. quinquefasciatus) mosquito larvae of southern Mexico. Three doses of each formulation were used in a first field trial: 2, 3 and 4 g/m2 (granular) or 2, 3 and 4 ml/m2 (liquid); and in a second field trial: 0.125, 0.24 and 0.5 g/m2 (granular) or 0.125, 0.25 and 0.5 ml/m2 (liquid). The optimum concentrations of each formulation for effective control of larval populations over periods of 3-4 months were 0.125 ml/m2 of liquid product for Culex spp. and 2 g/m2 of granular product for An. albimanus (ca. 70% mean reduction). PMID:2370538

  14. Susceptibility of three laboratory strains of Anopheles albimanus (Diptera: Culicidae) to coindigenous Plasmodium vivax circumsporozoite protein phenotypes in southern Mexico.

    PubMed

    Gonzalez-Ceron, L; Rodriguez, M H; Santillan, F V; Hernandez, J E; Wirtz, R A

    2000-05-01

    The susceptibility to two coindigenous Plasmodium vivax Grassi & Feletti phenotypes VK210 and VK247 of three colonized Anopheles albimanus Wiedemann strains (white-striped, green and brown) from southern Mexico was investigated. Mosquitoes of the three strains were simultaneously fed with P. vivax-infected patient blood and examined 1 wk later for the presence of oocysts. The circumsporozoite protein phenotype type (VK210 and VK247) was determined by immunoflorescence of salivary gland sporozoites using monoclonal antibodies. The proportions of specimens infected and the number of oocyst per mosquito indicated that all mosquito strains were more susceptible to the phenotype VK210 than to VK247, but the white-striped strain was more susceptible to both parasite phenotypes than the other two strains. PMID:15535573

  15. Mineral resources of the Petaca Pinta wilderness study area, Cibola County, New Mexico

    SciTech Connect

    Maxwell, C.H.; Nowlan, G.A.; Bankey, V.; Hannigan, B.J.

    1989-01-01

    This paper discusses the Petaca Pinta Wilderness Study Area in west-central New Mexico (11,688 acres) which is a small mesa with near-vertical 300-ft cliffs of Jurassic-age and Cretaceous-age sandstone overlying Triassic-age shale that forms steep slopes. This study area contains no identified metallic mineral resources but has inferred subeconomic resources of sandstone and sand. This study area has a low resource potential for undiscovered deposits of metals, including uranium, and has a moderate resource potential for the occurrence of oil and gas.

  16. Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico

    USGS Publications Warehouse

    Abbott, P.O.; Geldon, Arthur L.; Cain, Doug; Hall, Alan P.; Edelmann, Patrick

    1983-01-01

    Area 61 is located on the Colorado-New Mexico boundary in Huerfano and Las Animas Counties, Colorado, and Colfax County, New Mexico, and includes the Raton Mesa coal region. The 5 ,900-square-mile area is an asymmetrical structural trough bounded by the Rocky Mountains on the west and the Great Plains on the east. The area is drained by the Huerfano, Apishapa, Purgatoire, and Canadian Rivers (and their tributaries), all tributary to the Arkansas River. The principal coal-bearing formations are the Vermejo Formation of Late Cretaceous age and the Raton Formation of Late Cretaceous and Paleocene age. Much of the coal in the area is of coking quality, important to the metallurgical industry. Topographic relief in the area is greater than 8,700 feet, and this influences the climate which in turn affects the runoff pattern of area streams. Summer thunderstorms often result in flash floods. Virtually all geologic units in the region yield water. Depth to ground water ranges from land surface to 400 feet. Surface and ground water in the area contain mostly bicarbonate and sulfate ions; locally in the ground water, chloride ions predominate. Potential hydrologic problems associated with surface coal mining in the area are water-quality degradation, water-table decline, and increased erosion and sedimentation.

  17. Haliotrematoides spp. (Monogenoidea: Dactylogyridae) infecting the gills of grunts (Perciformes: Haemulidae) from the southern coast of Quintana Roo, Mexico.

    PubMed

    Mendoza-Franco, Edgar F; Reyes-Lizama, C; González-Solís, D

    2009-12-01

    One previously described species, Haliotrema striatohamus Zhukov, 1981, found off the coast of Cuba and Campeche (Gulf of Mexico), is redescribed and transferred to Haliotrematoides Kritsky, Yang and Sun, 2009, as Haliotrematoides striatohamus ( Zhukov, 1981) n. comb. This transfer is based on the study of new specimens of this species found in the gill lamellae of grunts, i.e., Haemulon aurolineatum Cuvier, Haemulon plumierii (Lacepède), and Haemulon sciurus (Shaw) (Haemulidae), all from the southern coast of Quintana Roo, Mexico. In addition, another previously described species, Haliotrema brevispirocirrus Zhukov, 1981 from Haemulon striatum (Linnaeus) from Havana, Cuba, is also transferred to Haliotrematoides based on the comparative morphology of its original description. Data are provided for prevalence and mean intensity as well as for the morphologic and biometric variability of H. striatohamus from different hosts. The new replacement of H. striatohamus ( Zhukov, 1981) n. comb. and H. brevispirocirrus (Zhukov, 1981) n. comb. infecting these taxa represents the first known species of Haliotrematoides on these fishes and new geographical records for these dactylogyrid monogenoids. PMID:19463040

  18. Bacterial symbionts of Bathymodiolus mussels and Escarpia tubeworms from Chapopote, an asphalt seep in the Southern Gulf of Mexico.

    PubMed

    Raggi, L; Schubotz, F; Hinrichs, K-U; Dubilier, N; Petersen, J M

    2013-07-01

    Chemosynthetic life was recently discovered at Chapopote, an asphalt hydrocarbon seep in the southern Gulf of Mexico. Preliminary morphological analyses indicated that one tubeworm and two mussel species colonize Chapopote. Our molecular analyses identified the tubeworm as Escarpia sp., and the mussels as Bathymodiolus heckerae and B. brooksi. Comparative 16S rRNA analysis and FISH showed that all three species harbour intracellular sulfur-oxidizing symbionts highly similar or identical to those found in the same host species from northern Gulf of Mexico (nGoM). The mussels also harbour methane-oxidizing symbionts, and these shared highly similar to identical 16S rRNA sequences to their nGoM conspecifics. We discovered a novel symbiont in B. heckerae, which is closely related to hydrocarbon-degrading bacteria of the genus Cycloclasticus. In B. heckerae, we found key genes for the use of aromatic compounds, and its stable carbon isotope values were consistently higher than B. brooksi, indicating that the novel symbiont might use isotopically heavy aromatic hydrocarbons from the asphalt seep. This discovery is particularly intriguing because until now only methane and reduced sulfur compounds have been shown to power cold-seep chemosynthetic symbioses. The abundant hydrocarbons available at Chapopote would provide these mussel symbioses with a rich source of nutrition. PMID:23279012

  19. Geochemical and geochronological study of the non-granitic pegmatite body "La Panchita", Oaxaca state, Southern Mexico

    NASA Astrophysics Data System (ADS)

    Shchepetilnikova, Valentina; Solé, Jesús; Solari, Luigi; Abdullin, Fanis

    2014-05-01

    The La Panchita pegmatite body intrudes a >10 m thick pyroxenite dike that in turn is cutting the central portion of ~1Ga Oaxacan Complex rocks, Southern Mexico. The Oaxacan Complex is the largest exposure in Mexico of Neoproterozoic basement rocks metamorphosed up to the granulite facies during the Grenville orogeny. This Complex has multiple intrusions of pegmatite bodies along its extension, some mineralogically simple, some complex. As for the mineralogy, the La Panchita pegmatite is distinct from other pegmatites of the Oaxacan Complex. It contains unusual minerals for a pegmatite, like scapolite and calcite, and it is a non-granitic pegmatite, as suggested before. This work presents preliminary geochemical and geochronological results of this pegmatite body and a discussion about its possible origin. The geochronological study shows that the time of emplacement of this pegmatite is 981.4 ± 7.4 Ma and it is post-tectonic with respect to the granulite facies metamorphic event of the Oaxacan Complex. The geochemical study shows that the pegmatite La Panchita formed during the evolution of an anorogenic magmatic source of carbonatitic-alkaline composition related to a post-Grenvillian rifting event. Medium to low-temperature thermochronometers (K-Ar, fission track and U-Th-He) from this pegmatite are under progress and the results will be given at the meeting.

  20. Agent-based modeling of deforestation in southern Yucatan, Mexico, and reforestation in the Midwest United States.

    PubMed

    Manson, Steven M; Evans, Tom

    2007-12-26

    We combine mixed-methods research with integrated agent-based modeling to understand land change and economic decision making in the United States and Mexico. This work demonstrates how sustainability science benefits from combining integrated agent-based modeling (which blends methods from the social, ecological, and information sciences) and mixed-methods research (which interleaves multiple approaches ranging from qualitative field research to quantitative laboratory experiments and interpretation of remotely sensed imagery). We test assumptions of utility-maximizing behavior in household-level landscape management in south-central Indiana, linking parcel data, land cover derived from aerial photography, and findings from laboratory experiments. We examine the role of uncertainty and limited information, preferences, differential demographic attributes, and past experience and future time horizons. We also use evolutionary programming to represent bounded rationality in agriculturalist households in the southern Yucatán of Mexico. This approach captures realistic rule of thumb strategies while identifying social and environmental factors in a manner similar to econometric models. These case studies highlight the role of computational models of decision making in land-change contexts and advance our understanding of decision making in general. PMID:18093928

  1. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley's Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  2. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley’s Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 to address the occurrence of high groundw...

  3. Construction of a remotely sensed area sampling frame for Southern Brazil

    NASA Technical Reports Server (NTRS)

    Fecso, R.; Gardner, W.; Hale, B.; Johnson, V.; Pavlasek, S. (Principal Investigator)

    1982-01-01

    A remotely sensed area sampling frame was constructed for selected areas in Southern Brazil. The sampling unit information was stored in digital form in a latitudinal/longitudinal characterized population. Computerized sampling procedures were developed which allow for flexibility in sample unit specifications and sampling designs.

  4. Coexisting sea-based and land-based sources of contamination by PAHs in the continental shelf sediments of Coatzacoalcos River discharge area (Gulf of Mexico).

    PubMed

    Ruiz-Fernández, Ana Carolina; Portela, Julián Mauricio Betancourt; Sericano, José Luis; Sanchez-Cabeza, Joan-Albert; Espinosa, Luisa Fernanda; Cardoso-Mohedano, José Gilberto; Pérez-Bernal, Libia Hascibe; Tinoco, Jesús Antonio Garay

    2016-02-01

    The oldest refinery and the major petrochemical complexes of Mexico are located in the lower reach of the Coatzacoalcos River, considered the most polluted coastal area of Mexico. A (210)Pb-dated sediment core, from the continental shelf of the Coatzacoalcos River, was studied to assess the contamination impact by the oil industry in the southern Gulf of Mexico. The sedimentary record showed the prevalence of petrogenic PAHs between 1950s and 1970s, a period during which waste discharges from the oil industry were not regulated. Later on, sediments exhibited higher contents of pyrogenic PAHs, attributed to the incineration of petrochemical industry wastes and recurrent wildfires in open dumpsites at the nearby swamps. The total concentration of the 16 EPA-priority PAHs indicated low levels of contamination (<100 ng g(-1)), except a peak value (>1000 ng g(-1)) during the late 1970s, most likely due to the major oil spill produced by the blowout of the Ixtoc-I offshore oil rig in deep waters of the southwestern Gulf of Mexico. Most of the PAH congeners did not show defined temporal trends but, according to a Factor Analysis, apparently have a common origin, probably waste released from the nearby oil industry. The only exceptions were the pyrogenic benzo(b)fluoranthene and benzo(a)pyrene, and the biogenic perylene, that showed increasing concentration trends with time, which we attributed to erosional input of contaminated soil from the catchment area. Our study confirmed chronic oil contamination in the Coatzacoalcos River coastal area from land based sources for more than 60 years (since 1950s). PMID:26397475

  5. 75 FR 17156 - Gulf of Mexico, Outer Continental Shelf, Western Planning Area, Oil and Gas Lease Sale 215 (2010...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-05

    ... Minerals Management Service Gulf of Mexico, Outer Continental Shelf, Western Planning Area, Oil and Gas Lease Sale 215 (2010) Environmental Assessment AGENCY: Minerals Management Service, Interior. ACTION: Notice of availability of an environmental assessment. SUMMARY: The Minerals Management Service (MMS)...

  6. Occurrence of Cryptosporidium and Giardia in Wild Ducks along the Rio Grande River Valley in Southern New Mexico

    PubMed Central

    Kuhn, Ryan C.; Rock, Channah M.; Oshima, Kevin H.

    2002-01-01

    Fecal samples were taken from wild ducks on the lower Rio Grande River around Las Cruces, N. Mex., from September 2000 to January 2001. Giardia cysts and Cryptosporidium oocysts were purified from 69 samples by sucrose enrichment followed by cesium chloride (CsCl) gradient centrifugation and were viewed via fluorescent-antibody (FA) staining. For some samples, recovered cysts and oocysts were further screened via PCR to determine the presence of Giardia lamblia and Crytosporidium parvum. The results of this study indicate that 49% of the ducks were carriers of Cryptosporidium, and the Cryptosporidium oocyst concentrations ranged from 0 to 2,182 oocysts per g of feces (mean ± standard deviation, 47.53 ± 270.3 oocysts per g); also, 28% of the ducks were positive for Giardia, and the Giardia cyst concentrations ranged from 0 to 29,293 cysts per g of feces (mean ± standard deviation, 436 ± 3,525.4 cysts per g). Of the 69 samples, only 14 had (oo)cyst concentrations that were above the PCR detection limit. Samples did test positive for Cryptosporidium sp. However, C. parvum and G. lamblia were not detected in any of the 14 samples tested by PCR. Ducks on their southern migration through southern New Mexico were positive for Cryptosporidium and Giardia as determined by FA staining, but C. parvum and G. lamblia were not detected. PMID:11772622

  7. Occurrence of Cryptosporidium and Giardia in wild ducks along the Rio Grande River valley in southern New Mexico.

    PubMed

    Kuhn, Ryan C; Rock, Channah M; Oshima, Kevin H

    2002-01-01

    Fecal samples were taken from wild ducks on the lower Rio Grande River around Las Cruces, N. Mex., from September 2000 to January 2001. Giardia cysts and Cryptosporidium oocysts were purified from 69 samples by sucrose enrichment followed by cesium chloride (CsCl) gradient centrifugation and were viewed via fluorescent-antibody (FA) staining. For some samples, recovered cysts and oocysts were further screened via PCR to determine the presence of Giardia lamblia and Crytosporidium parvum. The results of this study indicate that 49% of the ducks were carriers of Cryptosporidium, and the Cryptosporidium oocyst concentrations ranged from 0 to 2,182 oocysts per g of feces (mean +/- standard deviation, 47.53 +/- 270.3 oocysts per g); also, 28% of the ducks were positive for Giardia, and the Giardia cyst concentrations ranged from 0 to 29,293 cysts per g of feces (mean +/- standard deviation, 436 +/- 3,525.4 cysts per g). Of the 69 samples, only 14 had (oo)cyst concentrations that were above the PCR detection limit. Samples did test positive for Cryptosporidium sp. However, C. parvum and G. lamblia were not detected in any of the 14 samples tested by PCR. Ducks on their southern migration through southern New Mexico were positive for Cryptosporidium and Giardia as determined by FA staining, but C. parvum and G. lamblia were not detected. PMID:11772622

  8. Coastal circulation off southern Tamaulipas and northern Veracruz, western Gulf of Mexico, during winter 2012-2013

    NASA Astrophysics Data System (ADS)

    Rivas, David

    2015-04-01

    Four months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during winter 2012-2013 provides velocity, temperature, and salinity series in a region where apparently no in-situ measurements have been formally reported. The measurements show numerous events of intense alongshore velocities with magnitudes typically exceeding 80 cm/s, associated with intensified winds associated with the cold fronts invading the western Gulf during fall-winter, via coastal-trapped motions coming from northern locations. These motions must induce a coastal jet that modulates the regional along-shelf transports. This notion is corroborated by an analytical coastal-trapped wave (CTW) model which explains most of the variability of the sea level and the alongshore barotropic velocity observed in the mooring. Several near-inertial signals exceeding 50 cm/s are also observed at the surface levels. These high-frequency (HF) signals occur several hours before the intensified currents induced by the winds. Comparison between HF series of water velocity and wind suggests a direct influence of the winds affecting the NW Gulf (northern Tamaulipas/southern Texas) about 6-9 hours before the occurrence of the HF currents at the mooring. These near-inertial events induce a vigorous mixing of the local riverine discharge.

  9. 77 FR 40380 - Outer Continental Shelf, Gulf of Mexico, Oil and Gas Lease Sales, Western Planning Area Lease...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-09

    ... Bureau of Ocean Energy Management Outer Continental Shelf, Gulf of Mexico, Oil and Gas Lease Sales, Western Planning Area Lease Sale 233 and Central Planning Area Lease Sale 231 AGENCY: Bureau of Ocean... proposed Western Planning Area (WPA) Lease Sale 233 and Central Planning Area (CPA) Lease Sale 231...

  10. Gasoline distribution cycle and vapor emissions in Mexico City metropolitan area

    SciTech Connect

    Molina, M.M.; Secora, I.S.; Gallegos, J.R.M.; Grapain, V.M.G.; Villegas, F.M.R.; Flores, L.A.M.

    1997-12-31

    Ozone in the main air pollutant in Mexico City Metropolitan Area (MCMA). This kind of pollution is induced by the emissions of nitrogen oxides and hydrocarbons. According to Official Statistics National Air Pollution Quality Standard is exceeded over 300 days a year. Volatile hydrocarbons are generated in the cycle of storage transport and distribution of fuel (Gasoline Distribution Cycle). Above 17 millions of liters are handled daily in MCMA. Evaporative emission control is a complex task involving: floating roof tanks and vapor recovery units installation at bulk terminals and implementation of Phase 1 and Phase 2 vapor recovery systems at service stations. Since 1990, IMP has been involved in researching vapor emissions associated to gasoline storage and distribution cycle. Besides, the authors evaluate several technologies for bulk terminals and service stations. In this job, the authors present the results of an evaluation according to Mexican Official Standard of 500 vehicles. The gasoline vapors are trapped during refueling of cars and they are conduced to an equipment that includes an activated charcoal canister in order to adsorb them. Another Activated charcoal canister adsorbs ambient air as a reference. Experimental results showed that refueling hydrocarbon emissions are between 0.4 and 1.2 grams per liter with averages of 0.79 and 0.88 grams per liter according with two different gasoline types. These results were applied to Mexico City Vehicular fleet for the gasoline distribution cycle in order to obtain a total volatile hydrocarbon emission in Mexico City Metropolitan Area.

  11. Continuous measurement of carbon black in a densely populated area of Mexico City

    NASA Astrophysics Data System (ADS)

    Peralta, Oscar; Ortinez, Abraham; Castro, Telma; Espinosa, Maria; Saavedra, Isabel; Alvarez, Harry; Basaldud, Roberto; Paramo, Víctor; Martínez, Amparo

    2015-04-01

    The black carbon (BC) is a byproduct of burning fossil fuels and is an important short-lived climate forcer because it absorbs solar radiation altering the Earth's radiative budget and climate. It is also an atmospheric pollutant that promotes reactions of other compounds in the atmosphere. Despite its importance for health and climate, in Mexico there are very few studies on ambient concentrations of BC in urban areas and virtually no information of continuous measurements over long periods (more than a month of measurements). So, in order to develop more efficient local and regional mitigation strategies and policies that allow reducing ambient concentrations of BC, it is necessary to know BC seasonal evolution, contribution to radiative budget and impacts on health. This study shows continuous measurements (from July 2013 to July 2014) of BC to perform an analysis of seasonal variations. The selected monitoring site is located at Iztapalapa, a densely populated area with high traffic on the southeastern part of Mexico City. BC concentrations were obtained by two aethalometers (Magee Scientific Company, models AET31 and AET42) placed 15 meters above the ground. The aethalometers operate in the wavelength range of 370-950 nm and use a standard value of mass absorption coefficient MAC = 10.8 m2/g to calculate BC environmental concentration. To correct the aethalometers readings to the conditions of Mexico City, it was employed MAC = to 6.7 m2/g, which was determined for PM2.5 with a carbon analyzer (UIC, Inc.) and represents the mass absorption coefficient of soot emitted in Mexico City. The average value of the corrected concentration of BC in Mexico City during the period from July 2013 to July 2014 was 5.39 ± 1.89 μg/m3 (1.6 higher than readings recorded by aethalometers), which is greater than that measured in Shanghai in 2014 (annual average 2.33 μg/m3) and those reported for some U.S. cities; the value implies a potential danger to the health of

  12. Continuous measurement of carbon black in a densely populated area of Mexico City

    NASA Astrophysics Data System (ADS)

    Peralta, O.; Ortinez, A.; Castro, T.; Espinoza, M. D. L. L.; Saavedra, I.; Carabali-Sandoval, G. A., Sr.; Páramo, V. H.; Gavilán, A.; Martínez-Arroyo, A.

    2014-12-01

    The black carbon (BC) is a byproduct of burning fossil fuels and is an important short-lived climate forcer because it absorbs solar radiation altering the Earth's radiative budget and climate. It is also an atmospheric pollutant that promotes reactions of other compounds in the atmosphere. Despite its importance for health and climate, in Mexico there are very few studies on ambient concentrations of BC in urban areas and virtually no information of continuous measurements over long periods (more than a month of measurements). So, in order to develop more efficient local and regional mitigation strategies and policies that allow reducing ambient concentrations of BC, it is necessary to know BC seasonal evolution, contribution to radiative budget and impacts on health. This study shows continuous measurements (from July 2013 to July 2014) of BC to perform an analysis of seasonal variations. The selected monitoring site is located at Iztapalapa, a densely populated area with high traffic on the southeastern part of Mexico City. BC concentrations were obtained by two aethalometers (Magee Scientific Company, models AET31 and AET42) placed 15 meters above the ground. The aethalometers operate in the wavelength range of 370-950 nm and use a standard value of mass absorption coefficient MAC = 10.8 m2/g to calculate BC environmental concentration. To correct the aethalometers readings to the conditions of Mexico City, it was employed MAC = to 6.7 m2/g, which was determined for PM2.5 with a carbon analyzer (UIC, Inc.) and represents the mass absorption coefficient of soot emitted in Mexico City. The average value of the corrected concentration of BC in Mexico City during the period from July 2013 to July 2014 was 5.39 ± 1.89 μg/m3 (1.6 higher than readings recorded by aethalometers), which is greater than that measured in Shanghai in 2014 (annual average 2.33 μg/m3) and those reported for some U.S. cities; the value implies a potential danger to the health of

  13. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1986

    SciTech Connect

    Wiman, W.D.

    1987-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1986 was considerably reduced compared to 1985. Brazil, Colombia, Ecuador, Guatemala, and Venezuela had increased oil production, with Colombia showing a dramatic 71% increase attributed mainly to bringing on-stream the pipeline connecting Occidental-Shell-Ecopetrol's Cano Limon complex to the port of Covenas. Significant discoveries were reported from Argentina in the Olmedo, Oran, and San Jorge basins; Brazil in the offshore Campos and Amazon basins; Colombia in the Llanos basin; Ecuador in the Oriente basin; Mexico in the Bay of Campeche; Peru in the Ucayali basin; and Venezuela in the Eastern Venezuela basin. Eastern Venezuela's Furrial discovery is reported to have recoverable reserves of more than 1 million bbl of oil, and Shell's Ucayali basin discovery is reported to hold more than 7 tcf of gas. 7 figures, 10 tables.

  14. Hydrologic Evaluation of the Jungo Area, Southern Desert Valley, Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.

    2010-01-01

    RecologyTM, the primary San Francisco waste-disposal entity, is proposing to develop a Class 1 landfill near Jungo, Nevada. The proposal calls for the landfill to receive by rail about 20,000 tons of waste per week for up to 50 years. On September 22, 2009, the Interior Appropriation (S.A. 2494) was amended to require the U.S. Geological Survey to evaluate the proposed Jungo landfill site for: (1) potential water-quality impacts on nearby surface-water resources, including Rye Patch Reservoir and the Humboldt River; (2) potential impacts on municipal water resources of Winnemucca, Nevada; (3) locations and altitudes of aquifers; (4) how long it will take waste seepage from the site to contaminate local aquifers; and (5) the direction and distance that contaminated groundwater would travel at 95 and 190 years. This evaluation was based on review of existing data and information. Desert Valley is tributary to the Black Rock Desert via the Quinn River in northern Desert Valley. The Humboldt River and Rye Patch Reservoir would not be affected by surface releases from the proposed Jungo landfill site because they are in the Humboldt basin. Winnemucca, on the Humboldt River, is 30 miles east of the Jungo landfill site and in the Humboldt basin. Groundwater-flow directions indicate that subsurface flow near the proposed Jungo landfill site is toward the south-southwest. Therefore, municipal water resources of Winnemucca would not be affected by surface or subsurface releases from the proposed Jungo landfill site. Basin-fill aquifers underlie the 680-square-mile valley floor in Desert Valley. Altitudes around the proposed Jungo landfill site range from 4,162 to 4,175 feet. Depth to groundwater is fairly shallow in southern Desert Valley and is about 60 feet below land surface at the proposed Jungo landfill site. A groundwater divide exists about 7 miles north of the proposed Jungo landfill site. Groundwater north of the divide flows north towards the Quinn River. South of

  15. Common coastal foraging areas for loggerheads in the Gulf of Mexico: Opportunities for marine conservation

    USGS Publications Warehouse

    Hart, Kristen M.; Lamont, Margaret M.; Fujisaki, Ikuko; Tucker, Anton D.; Carthy, Raymond R.

    2012-01-01

    Designing conservation strategies that protect wide-ranging marine species is a significant challenge, but integrating regional telemetry datasets and synthesizing modeled movements and behavior offer promise for uncovering distinct at-sea areas that are important habitats for imperiled marine species. Movement paths of 10 satellite-tracked female loggerheads (Caretta caretta) from three separate subpopulations in the Gulf of Mexico, USA, revealed migration to discrete foraging sites in two common areas at-sea in 2008, 2009, and 2010. Foraging sites were 102–904 km away from nesting and tagging sites, and located off southwest Florida and the northern Yucatan Peninsula, Mexico. Within 3–35 days, turtles migrated to foraging sites where they all displayed high site fidelity over time. Core-use foraging areas were 13.0–335.2 km2 in size, in water <50 m deep, within a mean distance to nearest coastline of 58.5 km, and in areas of relatively high net primary productivity. The existence of shared regional foraging sites highlights an opportunity for marine conservation strategies to protect important at-sea habitats for these imperiled marine turtles, in both USA and international waters. Until now, knowledge of important at-sea foraging areas for adult loggerheads in the Gulf of Mexico has been limited. To better understand the spatial distribution of marine turtles that have complex life-histories, we propose further integration of disparate tracking data-sets at the oceanic scale along with modeling of movements to identify critical at-sea foraging habitats where individuals may be resident during non-nesting periods.

  16. Pink bollworm trapping in the Southern Plains of Texas and New Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study identified several cotton fields in southern Midland County, TX on which large numbers of pink bollworm (PBW) moths were caught. No other large concentrations of PBW were found in the region. Winds with the capability of moving moths long distances occurred during the 2010 study. Wind ...

  17. Karstification at Beskonak dam site and reservoir area, southern Turkey

    SciTech Connect

    Degirmenci, M.

    1993-10-01

    Beskonak dam and hydroelectric power plant are planned to be constructed on the Koepruecay river, 40 km east of the Antalya city. In the dam site and reservoir area, Koepruecay Conglomerates of Miocene age and the Beskonak Formation (sandstone-claystone) alternating with each other crop out vertically. Koepruecay conglomerates, with the components of limestone fragments and carbonate texture, are karstic and permeable, whereas the Beskonak Formation is impermeable. At the northern edge of the reservoir area, the Olukkoeprue karst springs discharge at a minimum of 30 m{sup 3}/s. These springs discharge mainly through vertical and subvertical joint systems. Intensive superficial karstification developed along the joint systems and the terrane reveals columns of rocks, called {open_quotes}fairy chimneys.{close_quotes} Olukkoeprue springs represent the discharge point for a large and continuous system of underground solution cavities. In the Koepruecay basin, there are numerous karstic features within the conglomerates. Within the reservoir area, Kurukoeprue cave, with a length of 530 m, is an example of these caves developed within the conglomerates. In some parts of the reservoir area, where the groundwater level is lower than the surface-river elevation, a highly developed karstification zone is present within the fluctuation range of groundwater between depths of 40 and 50 m. The above-mentioned Kurukoeprue cave is an active cave developed in the dam site and its vicinity. The solution conduits developed along the system of mostly vertical fractures and joints are interconnected, thus giving rise to a three-dimensional conduit network. On the other hand, a majority of these conduits have clay and calcite filling materials. Karstification in the dam site varies with depths exponentially. Data suggest that karstification has a vertical extention as deep as -220 m. 4 refs., 9 figs.

  18. Water quality, streamflow conditions, and annual flow-duration curves for streams of the San Juan–Chama Project, southern Colorado and northern New Mexico, 1935-2010

    USGS Publications Warehouse

    Falk, Sarah E.; Anderholm, Scott K.; Hafich, Katya A.

    2013-01-01

    The Albuquerque–Bernalillo County Water Utility Authority supplements the municipal water supply for the Albuquerque metropolitan area, in central New Mexico, with water diverted from the Rio Grande. Water diverted from the Rio Grande for municipal use is derived from the San Juan–Chama Project, which delivers water from streams in the southern San Juan Mountains in the Colorado River Basin in southern Colorado to the Rio Chama watershed and the Rio Grande Basin in northern New Mexico. The U.S. Geological Survey, in cooperation with Albuquerque–Bernalillo County Water Utility Authority, has compiled historical streamflow and water-quality data and collected new water-quality data to characterize the water quality and streamflow conditions and annual flow variability, as characterized by annual flow-duration curves, of streams of the San Juan–Chama Project. Nonparametric statistical methods were applied to calculate annual and monthly summary statistics of streamflow, trends in streamflow conditions were evaluated with the Mann–Kendall trend test, and annual variation in streamflow conditions was evaluated with annual flow-duration curves. The study area is located in northern New Mexico and southern Colorado and includes the Rio Blanco, Little Navajo River, and Navajo River, tributaries of the San Juan River in the Colorado River Basin located in the southern San Juan Mountains, and Willow Creek and Horse Lake Creek, tributaries of the Rio Chama in the Rio Grande Basin. The quality of water in the streams in the study area generally varied by watershed on the basis of the underlying geology and the volume and source of the streamflow. Water from the Rio Blanco and Little Navajo River watersheds, primarily underlain by volcanic deposits, volcaniclastic sediments and landslide deposits derived from these materials, was compositionally similar and had low specific-conductance values relative to the other streams in the study area. Water from the Navajo River

  19. Plasmodium vivax sporozoite rates from Anopheles albimanus in southern Chiapas, Mexico.

    PubMed

    Ramsey, J M; Salinas, E; Bown, D N; Rodriguez, M H

    1994-06-01

    Anopheles albimanus mosquitoes were collected from August 1984 to November 1987 on intra- and peridomicile human bait in Rancheria El Gancho, Chiapas, Mexico. The mosquitoes were desiccated and stored in silicon chambers from 3 mo to 3 yr post-collection prior to being assayed using a direct enzyme-linked immunosorbent assay to detect Plasmodium vivax predominant-type sporozoite protein. Peridomicile-collected mosquitoes had a 10-fold higher sporozoite rate than those collected indoors, but only the latter correlate significantly with the seasonal human parasite index. Mosquito sporozoite burden was also significantly higher in the peridomicile-collected population. PMID:8195955

  20. Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico

    USGS Publications Warehouse

    Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain-Iverson, Autumn R.; Peña, Jaime; Burchfield, Patrick M.; Gamez, Daniel Gomez; Ortiz, Jaime

    2013-01-01

    For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their "final" foraging sites. We identified new foraging "hotspots" where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species.

  1. Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico

    PubMed Central

    Shaver, Donna J; Hart, Kristen M; Fujisaki, Ikuko; Rubio, Cynthia; Sartain, Autumn R; Peña, Jaime; Burchfield, Patrick M; Gamez, Daniel Gomez; Ortiz, Jaime

    2013-01-01

    For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their “final” foraging sites. We identified new foraging “hotspots” where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species. PMID:23919146

  2. Environmental implications on the oxygenation of gasoline with ethanol in the metropolitan area of Mexico City.

    PubMed

    Schifter, I; Vera, M; Díaz, L; Guzmán, E; Ramos, F; López-Salinas, E

    2001-05-15

    Motor vehicle emission tests were performed on 12 in-use light duty vehicles, made up of the most representative emission control technologies in Mexico City: no catalyst, oxidative catalyst, and three way catalyst. Exhaust regulated (CO, NOx, and hydrocarbons) and toxic (benzene, formaldehyde, acetaldehyde, and 1,3-butadiene) emissions were evaluated for MTBE (5 vol %)- and ethanol (3, 6, and 10 vol %)-gasoline blends. The most significant overall emissions variations derived from the use of 6 vol % ethanol (relative to a 5% MTBE base gasoline) were 16% decrease in CO, 28% reduction in formaldehyde, and 80% increase in acetaldehyde emissions. A 26% reduction in CO emissions from the oldest fleet (< MY 1991, without catalytic converter), which represents about 44% of the in-use light duty vehicles in Mexico city, can be attained when using 6 vol% ethanol-gasoline, without significant variation in hydrocarbons and NOx emissions, when compared with a 5% vol MTBE-gasoline. On the basis of the emissions results, an estimation of the change in the motor vehicle emissions of the metropolitan area of Mexico city was calculated for the year 2010 if ethanol were to be used instead of MTBE, and the outcome was a considerable decrease in all regulated and toxic emissions, despite the growing motor vehicle population. PMID:11393966

  3. Understanding haze pollution over the southern Hebei area of China using the CMAQ model

    NASA Astrophysics Data System (ADS)

    Wang, Litao; Xu, Jing; Yang, Jing; Zhao, Xiujuan; Wei, Wei; Cheng, Dandan; Pan, Xuemei; Su, Jie

    2012-09-01

    Haze has been one of the major air pollution problems in Chinese cities, and the southern Hebei area has attracted particular attention because of its high frequency of haze weather and the rapid deterioration in visibility in recent years. This study is aimed at understanding the characteristics and sources of the serious haze pollution in the southern Hebei area using the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality Model (CMAQ). The haze frequencies in the cities of southern Hebei, including Shijiazhuang, Xingtai, and five other urban centers in the surrounding regions, are analyzed for a ten-year period from 2001 to 2010, which shows a very similar and clear seasonal variation. The contributions of the local and regional anthropogenic emissions to the concentration of fine particulate matter (PM2.5, particles with an aerodiameter of less than or equal to 2.5 μm) and the light extinction coefficient (Bext) are estimated by conducting simulations of seven scenarios. The results show that approximately 65% of the PM2.5 in Shijiazhuang and Xingtai originated from the local emissions of the southern Hebei area, followed by Shanxi Province and the northern area of Hebei (13.8% and 7.3% to Shijiazhuang and 10.4% and 5.2% to Xingtai, respectively). The contributions of the emissions from the local area, Shanxi Province and the northern Hebei area to Bext are approximately 59.4%, 13.8% and 6.8% for Shijiazhuang and 58.2%, 10.1% and 5.0% for Xingtai, respectively. Moreover, an analysis of a typical pollution episode indicates that the contributions from the Shandong and Henan provinces are also significant. Further investigations are still required because of the complexity of the haze pollution over the southern Hebei area.

  4. 77 FR 51568 - Outer Continental Shelf, Gulf of Mexico, Oil and Gas Lease Sales, Western Planning Area Lease...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ... and Central Planning Area (CPA) Lease Sale 231 (WPA/CPA Supplemental EIS) (77 FR 40380). Due to a BOEM... Bureau of Ocean Energy Management Outer Continental Shelf, Gulf of Mexico, Oil and Gas Lease Sales, Western Planning Area Lease Sale 233 and Central Planning Area Lease Sale 231 AGENCY: Bureau of...

  5. 33 CFR 334.660 - Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. 334.660 Section 334... Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. (a) The restricted area. A...

  6. 33 CFR 334.660 - Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. 334.660 Section 334... Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. (a) The restricted area. A...

  7. 33 CFR 334.660 - Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. 334.660 Section 334... Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. (a) The restricted area. A...

  8. 33 CFR 334.660 - Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. 334.660 Section 334... Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. (a) The restricted area. A...

  9. 33 CFR 334.660 - Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Gulf of Mexico and Apalachicola Bay south of Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. 334.660 Section 334... Apalachicola, Fla., Drone Recovery Area, Tyndall Air Force Base, Fla. (a) The restricted area. A...

  10. Ozone in remote areas of the Southern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Korfmacher, John L.

    2014-01-01

    Ozone (O3) data are sparse for remote, non-urban mountain areas of the western U.S. Ozone was monitored 2007-2011 at high elevation sites in national forests in Colorado and northeastern Utah using a portable battery-powered O3 monitor. The data suggest that many of these remote locations already have O3 concentrations that would contribute to exceedance of the current National Ambient Air Quality Standard (NAAQS) for O3 and most could exceed a proposed more stringent secondary standard. There were significant year-to-year differences in O3 concentration. Ozone was primarily in the mid-concentration range, rarely exceeding 100 ppb or dropping below 30 ppb. The small diel changes in concentration indicate mixing ratios of NOx, VOCs, and O3 that favor stable O3 concentrations. The large number of mid-level O3 concentrations contributed to high W126 O3 values, the metric proposed as a possible new secondary standard. Higher O3 concentrations in springtime and at night suggest that stratospheric intrusion may be contributing to ambient O3 at these sites. Highest nighttime O3 concentrations occurred at the highest elevations, while daytime O3 concentrations did not have a relationship with elevation. These factors favor O3 concentrations at many of our remote locations that may exceed the O3 NAAQS, and suggest that exceedances are likely to occur at other western rural locations.

  11. Assessing sedimentation rates at Usumacinta and Grijalva river basin (Southern Mexico) using OSL and suspended sediment load analysis: A study from the Maya Classic Period

    NASA Astrophysics Data System (ADS)

    Munoz-Salinas, E.; Castillo, M.; Sanderson, D.; Kinnaird, T.; Cruz-Zaragoza, E.

    2013-12-01

    Studying sedimentation rates on floodplains is key to understanding environmental changes occurred through time in river basins. The Usumacinta and Grijalva rivers flow most of their travel through the southern part of Mexico, forming a large river basin, crossing the states of Chiapas and Tabasco. The Usumacinta-Grijalva River Basin is within the 10 major rivers of North America, having a basin area of ~112 550 km2. We use the OSL technique for dating two sediment profiles and for obtaining luminescence signals in several sediment profiles located in the streambanks of the main trunk of the Usumacinta and Grijalva rivers. We also use mean annual values of suspended sediment load spanning ~50 years to calculate the sedimentation rates. Our OSL dating results start from the 4th Century, when the Maya Civilization was at its peak during the Classic Period. Sedimentation rates show a notable increase at the end of the 19th Century. The increase of the sedimentation rates seems to be related to changes in land uses in the Sierra Madre de Chiapas and Altos de Chiapas, based on deforestation and land clearing for developing new agrarian and pastoral activities. We conclude that the major environmental change in the basin of the Usumacinta and Grijalva Rivers since the Maya Classic Period was generated since the last Century as a result of an intense anthropogenic disturbance of mountain rain forest in Chiapas.

  12. Assessing morphological, climatic and structural factors controlling water discharge and sediment load of rivers flowing from the Sierra Madre de Chiapas to the Pacific Coast (Southern Mexico)

    NASA Astrophysics Data System (ADS)

    Munoz-Salinas, E.; Castillo, M.

    2014-12-01

    The Sierra Madre de Chiapas (SMC) is a steep mountain range located in the south-western part of Mexico with elevations higher than 2000 m. The SMC is ~30 km off the Pacific Coast and it is oriented parallel to the coast. The annual rainfall exceeds 6 m and most of this takes place during summer season when low-pressure systems and cyclones are frequent. The rivers in SMC incise into the granite and transport large volumes of sediment. Even though rivers can be regarded as bedrock bedrock channels these suddenly change to alluvial-type rivers when these flow in the coastal plain which is ~10 km from the headwater of rivers. There are not data available of the sediment yield of rivers, however, the well-broad coastal plain and the wide continental shelf suggest that the sediment transport from the mountain area to the lowlands is significantly high. Here we assess the main morphological, climatic and structural factors controlling water discharge and sediment load of the rivers flowing from the SMC to the Pacific Coast by means of (1) topographical analysis on a high-resolution DEM, (2) grain-size and OSL analysis on sediment extracted from the riverbed of the main rivers and (3) time-series analysis from the available data of sediment discharge and sediment load. Our results indicate that the river incision and sediment transport is particularly high at the southern sector of the SMC where the topographic and climatic factors promote higher erosion rates.

  13. A suggested local regions in the Southern Gulf of Mexico using a diatom database (1979-2002) and oceanic hidrographic features.

    PubMed

    Licea, Sergio; Zamudio, Ma E; Moreno-Ruiz, J L; Luna, R

    2011-07-01

    A diatom data-base of 255 species obtained from 14 oceanographic cruises (14801 entries of 647 sampling sites) together with the analysis of oceanic features were used to establish four local regions in the southern Gulf of Mexico. In addition, common species for each region were designated. This study is based on the application of cluster analysis and the species frequency data. Material for this undertaking consisted of water and net samples obtained between June 1979 and December 2002. Results show that the most frequent species (> 40%) were: Asterionellopsis glacialis, Bacteriastrum delicatulum, B. hyalinum, Chaetoceros affinis, C. coarctatus, C. compresus, C. curvisetus, C. danicus, C. decipiens, C. diversus, C. lorenzianus, C. pelagicus, C. peruvianus, Coscinodiscus radiatus, Cylindrotheca closterium, Guinardia flaccida, Hemiaulus hauckii, H. membranaceus, H. sinensis, Leptocylindrus danicus, Neocalyptrella robusta, Nitzschia bicapitata, Pleurosigma diverse-striatum, Proboscia alata, Pseudo-nitzschia pungens, Pseudosolenia calcar-avis, Rhizosolenia imbricata, R. setigera, Skeletonema costatum, Thalassionema bacillare, T frauenfeldii, T nitzschioides and Thalassiosira eccentrica. The species composition for each region and season are discussed. Itis concluded that sampling site assemblages are related to oceanographic conditions. A total list of species composition is given, forty-seven species taxa being new records for this area. PMID:22315823

  14. Processed Thematic Mapper Satellite Imagery for Selected Areas within the U.S.-Mexico Borderlands

    USGS Publications Warehouse

    Dohrenwend, John C.; Gray, Floyd; Miller, Robert J.

    2000-01-01

    The study is summarized in the Adobe Acrobat Portable Document Format (PDF) file OF00-309.PDF. This publication also contain satellite full-scene images of selected areas along the U.S.-Mexico border. These images are presented as high-resolution images in jpeg format (IMAGES). The folder LOCATIONS in contains TIFF images showing exact positions of easily-identified reference locations for each of the Landsat TM scenes located at least partly within the U.S. A reference location table (BDRLOCS.DOC in MS Word format) lists the latitude and longitude of each reference location with a nominal precision of 0.001 minute of arc

  15. Differential susceptibilities of Anopheles albimanus and Anopheles pseudopunctipennis to infections with coindigenous Plasmodium vivax variants VK210 and VK247 in southern Mexico.

    PubMed

    Gonzalez-Ceron, L; Rodriguez, M H; Nettel, J C; Villarreal, C; Kain, K C; Hernandez, J E

    1999-01-01

    The susceptibilities to coindigenous Plasmodium vivax of colonized Anopheles albimanus and Anopheles pseudopunctipennis from southern Mexico were investigated by simultaneous feeding with infected blood obtained from patients. The genes encoding circumsporozoite protein variant types (VK210 and VK247) in blood samples were determined by PCR and oligonucleotide probe hybridization. A. albimanus was more susceptible to VK210, and A. pseudopunctipennis was more susceptible to VK247. PMID:9864243

  16. Geochemical map of the Guadalupe Escarpment Wilderness Study Area, Eddy County, New Mexico

    USGS Publications Warehouse

    Light, T.D.; Domenico, J.A.; Smith, S.M.

    1985-01-01

    The Guadalupe Escarpment Wilderness Study Area encompasses approximately 21,300 acres along Guadalupe Ridge in the southern end of the Guadalupe Mountains about 35 miles southwest of Carlsbad, N. Mex. (fig. 1). The area trends northeasterly, is bounded on the south by the Texas State line and the northern boundary of Guadalupe Mountains National Park. The study area is bounded on the northeast by Carlsbad Caverns National Park. The area comprises several narrow, gently sloping mesas bounded by deeply incised canyons. Elevations range from 7,413 feet on Camp Wilderness Ridge to approximately 4,875 feet at Franks Spring. A rough jeep road along the northwest boundary of the study area can be reached by U.S. Forest Service roads from the northwest. The southeastern part of the study area can be approached via unimproved ranch roads leading off U.S. Highway 62-180.

  17. Preliminary analysis of gravity and aeromagnetic surveys of the Timber Mountain Area, southern Nevada

    SciTech Connect

    Kane, M.F.; Webring, M.W.; Bhattacharyya, B.K.

    1981-12-31

    Recent (1977 to 1978) gravity and aeromagnetic surveys of the Timber Mountain region, southern Nevada, have revealed new details of subsurface structure and lithology. The data strongly suggest that deformation caused by volcanic events has been accommodated along straight-line faults combining in such a fashion as to given a curvilinear appearance to regional structure. The magnetic data suggest that rock units in the central graben and along the southeast margin of Timber Mountain may have been altered, perhaps thermally, from their original state. The gravity data indicate that the south part of the Timber Mountain is underlain by relatively dense rock possibly intrusive rock, like that which crops out along its southeast side. The gravity data also suggest that the Silent Canyon caldera may extend considerably south of its presently indicated southern limit and may underlie much of the area of Timber Mountain. The moat areas appear to be more rectangular or triangular than annular in shape. The southern part of Timber Mountain caldera is separated from the Yucca Mountain area to the south by a triangular horst. The structural relations of the rock units making up the horst are complex. Several linear terrain features in the southern part of the caldera area are closely aligned with geophysical features, implying that the terrain features are fault-controlled.

  18. Submicron organic aerosol in Tijuana, Mexico, from local and Southern California sources during the CalMex campaign

    NASA Astrophysics Data System (ADS)

    Takahama, S.; Johnson, A.; Guzman Morales, J.; Russell, L. M.; Duran, R.; Rodriguez, G.; Zheng, J.; Zhang, R.; Toom-Sauntry, D.; Leaitch, W. R.

    2013-05-01

    The CalMex campaign was conducted from May 15 to June 30 of 2010 to study the properties and sources of air pollution in Tijuana, Mexico. In this study, submicron organic aerosol mass (OM) composition measured by Fourier Transform Infrared Spectroscopy (FTIR), Aerosol Chemical Speciation Monitor (ACSM), and X-ray spectromicroscopy are combined with statistical analysis and measurements of other atmospheric constituents. The average (±one standard deviation) OM concentration was 3.3 ± 1.7 μg m-3. A large source of submicron aerosol mass at this location was determined to be vehicular sources, which contributed approximately 40% to the submicron OM; largely during weekday mornings. The O/C ratio estimated from ACSM measurements was 0.64 ± 0.19; diurnal variations in this value and the more oxygenated fraction of OM as determined from Positive Matrix Factorization and classification analyses suggest the high degree of oxygenation originates from aged OM, rather than locally-produced secondary organic aerosol. A large contribution of this oxygenated aerosol to Tijuana from various source classes was observed; some fraction of this aerosol mass may be associated with non-refractory components, such as dust or BC. Backtrajectory simulations using the HYSPLIT model suggest that the mean wind vector consistently originated from the northwest region, over the Pacific Ocean and near the Southern California coast, which suggests that the origin of much of the oxygenated organic aerosol observed in Tijuana (as much as 60% of OM) may have been the Southern California Air Basin. The marine aerosol contribution to OM during the period was on average 23 ± 24%, though its contribution varied over synoptic rather than diurnal timescales. BB aerosol contributed 20 ± 20% of the OM during the campaign period, with notable BB events occurring during several weekend evenings.

  19. Distribution pattern of picoplankton carbon biomass linked to mesoscale dynamics in the southern gulf of Mexico during winter conditions

    NASA Astrophysics Data System (ADS)

    Linacre, Lorena; Lara-Lara, Rubén; Camacho-Ibar, Víctor; Herguera, Juan Carlos; Bazán-Guzmán, Carmen; Ferreira-Bartrina, Vicente

    2015-12-01

    In order to characterize the carbon biomass spatial distribution of autotrophic and heterotrophic picoplankton populations linked to mesoscale dynamics, an investigation over an extensive open-ocean region of the southern Gulf of Mexico (GM) was conducted. Seawater samples from the mixed layer were collected during wintertime (February-March 2013). Picoplankton populations were counted and sorted using flow cytometry analyses. Carbon biomass was assessed based on in situ cell abundances and conversion factors from the literature. Approximately 46% of the total picoplankton biomass was composed of three autotrophic populations (Prochlorococcus, Synechococcus, and pico-eukaryotes), while 54% consisted of heterotrophic bacteria populations. Prochlorococcus spp. was the most abundant pico-primary producer (>80%), and accounted for more than 60% of the total pico-autotrophic biomass. The distribution patterns of picoplankton biomass were strongly associated with the mesoscale dynamics that modulated the hydrographic conditions of the surface mixed layer. The main features of the carbon distribution pattern were: (1) the deepening of picoplankton biomass to layers closer to the nitracline base in anticyclonic eddies; (2) the shoaling of picoplankton biomass in cyclonic eddies, constraining the autoprokaryote biomasses to the upper layers, as well as accumulating the pico-eukaryote biomass in the cold core of the eddies; and (3) the increase of heterotrophic bacteria biomass in frontal regions between counter-paired anticyclonic and cyclonic eddies. Factors related to nutrient preferences and light conditions may as well have contributed to the distribution pattern of the microbial populations. The findings reveal the great influence of the mesoscale dynamics on the distribution of picoplankton populations within the mixed layer. Moreover, the significance of microbial components (especially Prochlorococcus) in the southern GM during winter conditions was revealed

  20. Crustal Structure of Southern Baja California Peninsula, Mexico, and its Margins

    NASA Astrophysics Data System (ADS)

    Gonzalez, A.; Robles-Vazquez, L. N.; Requena-Gonzalez, N. A.; Fletcher, J.; Lizarralde, D.; Kent, G.; Harding, A.; Holbrook, S.; Umhoefer, P.; Axen, G.

    2007-05-01

    Data from 6 deep 2D multichannel seismic (MCS) lines, 1 wide-angle seismic transect and gravity were used to investigate the crustal structure and stratigraphy of the southern Baja California peninsula and its margins. An array of air guns was used as seismic source shooting each 50 m. Each signal was recorded during 16 s by a 6 km long streamer with 480 channels and a spacing of 12.5 m. Seismic waves were also recorded by Ocean Bottom Seismometers (OBS) in the Pacific and the Gulf of California and by portable seismic instruments onshore southern Baja California. MCS data were conventionally processed, to obtain post-stack time-migrated seismic sections. We used a direct method for the interpretation of the wide-angle data, including ray tracing and travel times calculation. In addition to the gravity data recorded onboard, satellite and land public domain data were also used in the gravity modeling. The combined MCS, wide-angle and gravity transect between the Magdalena microplate to the center of Farallon basin in the Gulf of California, crossing the southern Baja California Peninsula to the north of La Paz, allows to verify the existence of the Magdalena microplate under Baja California. We have also confirmed an extensional component of the Tosco-Abreojos fault zone and we have calculated crustal thicknesses. We have also observed the continuation to the south of the Santa Margarita detachment. The MCS seismic sections show a number of fault scarps, submarine canyons and grabens and horsts associated to normal faults offshore southern Baja California peninsula. The normal displacement observed in the Tosco-Abreojos fault zone and some basins in the continental platform, as well as the presence of faulted acoustic basement blocks, evidence that not all extension was accommodated by the Gulf Extensional Province during the middle to late Miocene. Part of the extension was (and is) accommodated in the Baja California Pacific margin. This confirms the observations

  1. Southern Cordilleran basaltic andesite suite, southern Chihuahua, Mexico: A link between Tertiary continental arc and flood basalt magmatism in North America

    NASA Astrophysics Data System (ADS)

    Cameron, K. L.; Nimz, G. J.; Kuentz, D.; Niemeyer, S.; Gunn, S.

    1989-06-01

    Mid-Cenozoic orogenic andesites and ignimbrites of western Mexico, southwestern New Mexico, and Arizona are commonly capped by basaltic andesites, most from 29-20 Ma. We refer to these mafic lavas as the Southern Cordilleran Basaltic Andesite (SCORBA) suite, and they may constitute the most extensive Cenozoic basaltic suite in North America. The SCORBA suite has trace element and isotopic characteristics of orogenic (arc) rocks (e.g., Ba/Nb>40), and silica content (53-56% SiO2) like the Grande Ronde Basalt, which represents about 80% of the volume of the Columbia River Group. Geochemical and isotopic data are presented on SCORBA lavas and rare mafic lavas (PRE-SCORBA) interlayered with older ignimbrites from a 700-km-long NE-SW transect of southern Chihuahua, Mexico. SCORBA and PRE-SCORBA lavas with relatively low K/P (<7) and differing Ba/Nb (50 versus 18) have similar isotopic compositions, arguing against their isotopic signatures being controlled by crustal assimilation. Along the entire length of the transect, the basaltic rocks have ɛNd and 87Sr/86Sr near bulk Earth and 206Pb/204Pb and 207Pb/204Pb ratios that lie along a 1.7 Ga pseudoisochron. The Pb isotopic variation is geographically controlled, becoming more radiogenic from east to west, reflecting mixing in mantle source regions. The eastern mantle source has low 206Pb/204Pb and is a mixture of an enriched, enriched-mantle-like (EMI) component with one or more depleted components, which could include an intraplate component with relatively high Nb/Y (>0.8). The western mantle source contains less of the intraplate component and is more oceanic in character. Overprinting both the eastern and western sources is a Cenozoic subduction component that is responsible for the western radiogenic Pb, and this component fades out inland to the east. This transect crosses the inferred position of the Mojave-Sonora megashear, previously proposed to be a major lithospheric boundary, separating Proterozoic basement to

  2. A new species of bunchgrass lizard (Squamata: Phrynosomatidae) from the southern sky islands of the Sierra Madre Occidental, Mexico.

    PubMed

    Grummer, Jared A; Bryson, Robert W

    2014-01-01

    A new species of bunchgrass lizard in the Sceloporus scalaris group is described from the southern portion of the Sierra Madre Occidental in Mexico. The new species, Sceloporus aurantius sp. nov., was previously confused with S. brownorum but differs from this and all but one species within the S. scalaris group by a lack of blue belly patches in males. It shares with S. chaneyi an absence of blue belly patches, but differs from this species in size, number of dorsal scales, number of scales around midbody, and presence of an un-patterned morph. The new species further differs from S. chaneyi, and all other species in the S. scalaris species group, by unique phylogenetic position revealed through species delimitation based on multi-locus nuclear DNA. Principal component analyses of 24 traditional morphological characters used to describe previous S. scalaris group taxa indicate that these characters may be of limited use to delineate species in this species group. However, male lateral and ventral coloration may still be an important character for diagnosing species. PMID:24869877

  3. Comparison of two carbonate mound sequences in the Lower Ordovician El Paso Formation, west Texas and southern New Mexico

    SciTech Connect

    Clemons, R.E.

    1985-01-01

    The El Paso Formations consists of four members, in ascending order: Hitt Canyon, Jose McKelligon and Padre. Mounds in the McKelligon Member exposed in the southern Franklin Mountains were described by Toomey (1970). Most of these mounds are small but one large one is 5.8 m thick and about 13.7 m long in outcrop. The mound rock is chiefly bioclastic wackestone with minor packstone and boundstone. The varied fauna contains echinoderms, sponges and spicules, gastropods, trilobites, digitate algae, Nuia, Girvanella, Pulchrilamina, Calathium, and minor brachiopods and cephalopods. Intraclastic, bioclastic grainstone fills channels cut in the mounds. Similar, but smaller and less spectacular mounds occur in the McKelligon Member in the Florida, Big Hatchet, and Caballo Mountains, Lone Mountain, Cooke's Range, and elsewhere in southwestern New Mexico. A second type of mound is common in the upper part of the Hitt Canyon Member in the Cooke's Range, Red Hills, Caballo and Big Hatchet Mountains. These mounds also are typically small but one in the Red Hills is 13.7 m thick and about 30 m long in outcrop. The mound complex is about 75-80% SH-C and LLH-C stromatolite boundstone and bioclastic wackestone. The remaining 20-25% is bioclastic packstone and grainstone between the SH-C stromatolites and filling channels cut in the mound complex. The limited fauna contains small fragments of echinoderms, gastropods, trilobites, spicules, and Nuia.

  4. Mercury Concentrations in Pacific Angel Sharks (Squatina californica) and Prey Fishes from Southern Gulf of California, Mexico.

    PubMed

    Escobar-Sánchez, O; Ruelas-Inzunza, J; Moreno-Sánchez, X G; Romo-Piñera, A K; Frías-Espericueta, M G

    2016-01-01

    Concentrations of mercury (Hg) were quantified in muscle tissues of the Pacific angel shark, Squatina californica sampled from Southern Gulf of California, Mexico, considering total length, sex, diet and the dietary risk assessment. High Hg levels are typically associated with carnivorous fishes, however S. californica showed low Hg concentrations (<1.0 µg g(-1)) in muscle (0.24 ± 0.27 µg g(-1) wet weight; n = 94). No effect of sex, total length and weight on Hg concentrations were observed in the shark (p > 0.05). Hg concentrations were highest in the darkedge mishipman: Porichthys analis (0.14 ± 0.08 µg g(-1)) and red-eye round herring Etrumeus teres (0.13 ± 0.05 µg g(-1)) relative to other prey species, which could suggest that Hg concentrations in S. californica were influenced by these species. Given the relatively low concentration of Hg across age-classes and sex, consumption of S. californica's muscle tissue poses limited risk to humans. PMID:26644027

  5. Seismicity in the Raton Basin of Southern Colorado and Northern New Mexico, USA, as Recorded by a Local Array

    NASA Astrophysics Data System (ADS)

    Macartney, H.

    2013-12-01

    Microseismic events (southern Colorado and northern New Mexico, USA, over a period of 18 months following the occurrence of a 5.3 magnitude event near Trinidad CO in August, 2011. Micro-seismicity was observed in the region, concentrated in six clusters at depths of 6-12 km below the surface, deep in the basement, and 4-10 km below zones used for fluid disposal from an overlying coalbed methane natural gas field. Clusters are separated from disposal zones by large aseismic intervals. The clusters are mixed in character; both planar and elongate amorphous swarms, some continually active and some as short-lived bursts, with larger initial events tending to occur deeper and smaller after-shocks propagating upward and away from the nucleating events. Magnitudes range between 0 and 3, with the vast majority being less than 1.5M. Most of the clusters have no disposal wells above and no seismic activity was correlated with changes in fluid disposal. No seismicity was detected from hydraulic fracturing operations.

  6. Near-coastal ocean variability off southern Tamaulipas - northern Veracruz, western Gulf of Mexico, during spring-summer 2013

    NASA Astrophysics Data System (ADS)

    Rivas, David

    2016-04-01

    Six months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during spring-summer 2013 provides velocity, temperature, salinity, sea level, and dissolved oxygen series in a region which ocean dynamics is still poorly understood. As shown in a preceding analysis of this region's winter circulation for winter 2012-2013, coastal trapped motions associated with the regional invasion of synoptic cold fronts modulate the local variability; this pattern remains in the spring 2013, when even more intense events of alongshore flow (>50 cm/s) are observed. This intensified flow is associated with a significant decrease in the dissolved oxygen, most probably related to an influence of hypoxic waters coming from the northern Gulf. In late spring-mid summer, the wind pattern corresponds to persistent southeasterly winds that favor the occurrence of a local upwelling, which maintains a local thermal reduction (>3 degrees Celsius) and is associated with a persistent northward flow (>30 cm/s). The late summer was characterized by a significant tropical-cyclone activity, when a depression, a storm, and a hurricane affected the western Gulf. These tropical systems caused an intense precipitation and hence an important intensification of the local riverine discharge, and the winds enhanced the mixing of such riverine waters, via mostly kinetic stirring and Ekman pumping.

  7. Regional photochemical air quality modeling in the Mexico-US border area

    SciTech Connect

    Mendoza, A.; Russell, A.G.; Mejia, G.M.

    1998-12-31

    The Mexico-United States border area has become an increasingly important region due to its commercial, industrial and urban growth. As a result, environmental concerns have risen. Treaties like the North American Free Trade Agreement (NAFTA) have further motivated the development of environmental impact assessment in the area. Of particular concern are air quality, and how the activities on both sides of the border contribute to its degradation. This paper presents results of applying a three-dimensional photochemical airshed model to study air pollution dynamics along the Mexico-United States border. In addition, studies were conducted to assess how size resolution impacts the model performance. The model performed within acceptable statistic limits using 12.5 x 12.5 km{sup 2} grid cells, and the benefits using finer grids were limited. Results were further used to assess the influence of grid-cell size on the modeling of control strategies, where coarser grids lead to significant loss of information.

  8. Ignimbrite Flare-up in the North-Central Sierra Madre del Sur, Southern Mexico: a Continuation of the Sierra Madre Occidental Ignimbrite Province?

    NASA Astrophysics Data System (ADS)

    Moran-Zenteno, D. J.; Alba-Aldave, L.; Gonzalez-Torres, E. A.; Martiny, B.; Bravo-Diaz, B. A.; Sohn, E.

    2007-05-01

    The north-central Sierra Madre del Sur, immediately south of the Trans Mexican Volcanic Belt, is made up of a series of Eocene silicic volcanic centers distributed along a WNW trending 300 km long belt from Valle de Bravo to Huautla (98°50'-100°30'W longitude). This belt constitutes an inland arc near parallel to, and coeval with, the coastal batholitic belt of southern Mexico. It includes at least 9 exhumed volcanic edifices that display diverse caldera styles controlled by regional fracture zones and rheological contrasts in the host rocks. Initiation of the volcanism ranges from 37 Ma in the west to 32 Ma in the east, and extinction of magmatism was nearly simultaneous in the eastern half of the belt. Southwest of the silicic volcanic belt, andesitic volcanism is slightly younger (33-29 Ma) and the combined effect of post-Eocene uplift and erosion removed most of the extracaldera facies. The remnants of the silicic volcanic cover extend over an area of ~3000 km2. Reactivated fracture zones related to the volcanic activity include NW to W- trending faults that reveal a transition from left lateral to right lateral slip as result of a change in the stress field during the last stages of silicic volcanism. These and other groups of N-S to NNW trending faults accommodated the collapse structures and were the sites of emplacement of massive pyroclastic dikes. Immediately north of the Trans Mexican Volcanic Belt, ignimbrites and related rocks of the Mesa Central and southern Sierra Madre Occidental are slightly younger and display a westward 30 to ~15 Ma migration pattern accompanied by E-W regional extension. These patterns have been attributed to the roll back of the subducted slab, which caused the ascent of asthenospheric mantle and probably triggered ignimbrite flare-up. The distinct tectonic and geochronologic patterns of the arc volcanic rocks in the northern Sierra Madre del Sur and the southern Sierra Madre Occidental-Mesa Central suggests two slab segments

  9. Dinosaur Footprints in Lower Cretaceous Beds in San Juan Raya, Southern Mexico and the Paleoenvironmental Implications

    NASA Astrophysics Data System (ADS)

    Aceves, D.

    2008-12-01

    Dinosaur footprints were traced at San Juan Raya, an important site in Mexico, a world fossil site. This site is found at South-west of the State of Puebla, within the Biosphere Reserve of Tehuacan-Cuitcatlán, to the southwest of the Tehuacan valley. These footprints were recorded by tracing them on transparent paper at Barranca Agua Nueva, at point 18°18.56´N 97°37´W. Using Jacob´s staff a stratigraphic register was generated from 50 m ascending and descending in stratigraphically direction from the bed where footprints were founded. Bivalbes, nerineas, shell fragments, and trigonias were founded in this sequence as well as cross bedding of clays and fine grain sand, some which display ripples. Fifty two footprints were recorded and five different tracks identified, observing two different sizes. The tracks of dinosaur footprints present the common Teropode ichnites. The succession where dinosaur footprints have been found, are interpreted as a peritidal environment. This investigation contributes to an eco-tourism project of San Juan Raya.

  10. Metals in the caudal scutes of Morelet's crocodile (Crocodylus moreletii) from the southern Gulf of Mexico.

    PubMed

    Trillanes, C E; Pérez-Jiménez, J C; Rosíles-Martínez, R; González-Jáuregui, M

    2014-10-01

    Caudal scutes were collected from 92 Morelet's crocodiles (Crocodylus moreletii) between May and August 2012, in three Wildlife Management and Use Units (UMAs, from its name in Spanish) and three wild sites in Campeche, Mexico. The UMAs are intensive, with an ex situ approach to manage crocodiles in captivity. The concentrations of arsenic, mercury, lead, nickel, cadmium and chromium were analyzed in each sample. As and Pb were detected in all samples, Hg in 86 and Ni in 74. The metal concentrations estimated were higher than most of the concentrations reported for skin, tail tip and caudal scutes in other crocodilians around the world. The concentration of As, Pb and Ni was significantly greater in the free-ranging groups than in the captive groups in UMAs (p < 0.05). Negative linear relationship was estimated between the snout-vent length and the concentration of Pb (in five groups) and Ni (in three groups). In this region C. moreletii is exposed to metals contamination and more studies are necessary to establish if represents a risk to their populations. PMID:25134925

  11. Time-lapse seismic study of levees in southern New Mexico

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Stimac, N.; Ballard, R.F., Jr.; Dunbar, J. Joseph; Smullen, S. Steve

    2006-01-01

    The primary objective of this work was to measure changes in compressional- (Vp) and shear-wave (Vs) velocities in an earthen levee during a ponding experiment designed to simulate flood conditions on the Rio Grande in south New Mexico. Although similar to such experiment, performed an year earlier on the Rio Grande in south Texas, the levee seismic response results are different. This work was similar to previous Preliminary testing at three levee sites, all within a 1 km radius and each with unique physical, EM, and core characteristics, was completed and a single low-conductivity, highly fractured site was selected for investigation. Several different types of seismic data were recorded. Seismic data analysis techniques appraised included P-refraction tomography and Rayleigh surface-wave analysis using multichannel analysis of surface waves (MASW). P-wave velocity change (decrease) was rapid and isolated to one section within the pool confines, which already had anomalously high velocity most likely related to burrowing animals modification of the levee structure. S-wave velocity change was gradual and could be observed along the whole width of the pond within and below the levee. The results within the levee sand core were consistent with the observations of sand S-wave velocity changed due to saturation. ?? 2005 Society of Exploration Geophysicists.

  12. Nitric oxide emission from arid grassland and shrubland ecosystems in southern New Mexico

    SciTech Connect

    Hartley, A.E.; Schlesinger, W.H. )

    1993-06-01

    Soil nitrogen losses are characteristic of the transition from semi-arid grassland to arid shrubland in the southwestern United States. Nitrogen gas emission from soil microbial activity contributes to the long-term reduction of soil fertility associated with desertification. We investigated nitric Oxide (NO) emission from arid soils in the Jornada Experimental Range, near Las Cruces, New Mexico. During the dry season, mean NO fluxes from coarse-textured soils in a Boutelcua grassland and a Larrea shrubland were similar (0.12 and 0.15 ng NO-N cm[sup [minus]2] hr[sup [minus]1], respectively), and higher than flexes from fine-textured soils in a Flourensia shrubland (0.02 ng NO-N cm[sup [minus]2] hr[sup [minus]1]). In a wetting experiment, mean NO fluxes were higher under shrub canopies of Larrea and Flourensia, reflecting the accumulation of soil organic matter under shrubs in islands of fertility. In the Larrea shrubland, mean NO fluxes were ten times higher under shrubs than between shrubs (12.9 vs. 1.29 ng NO-N cm[sup [minus]2] hr[sup [minus]1]).

  13. Host selection and gonotrophic cycle length of Anopheles punctimacula in southern Mexico.

    PubMed

    Ulloa, Armando; Gonzalez-Cerón, Lilia; Rodríguez, Mario H

    2006-12-01

    The host preference, survival rates, and length of the gonotrophic cycle of Anopheles punctimacula was investigated in southern México. Mosquitoes were collected in 15-day separate experiments during the rainy and dry seasons. Daily changes in the parous-nulliparous ratio were recorded and the gonotrophic cycle length was estimated by a time series analysis. Anopheles punctimacula was most abundant during the dry season and preferred animals to humans. The daily survival rate in mosquitoes collected in animal traps was 0.96 (parity rate = 0.86; gonotrophic cycle = 4 days). The length of gonotrophic cycle of 4 days was estimated on the base of a high correlation coefficient value appearing every 4 days. The minimum time estimated for developing mature eggs after blood feeding was 72 h. The proportion of mosquitoes living enough to transmit Plasmodium vivax malaria during the dry season was 0.35. PMID:17304932

  14. 76 FR 7228 - Outer Continental Shelf (OCS), Western and Central Planning Areas of the Gulf of Mexico (GOM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ... Leasing Program: 2012-2017 (See FR Vol. 75, No. 63, Page 16828, April 2, 2010). BOEMRE is combining... Central Planning Areas of the Gulf of Mexico (GOM), Oil and Gas Lease Sales for 2012-2017 AGENCY: Bureau...- 2017 oil and gas leasing proposals in the Western and Central Planning Areas of the GOM, off the...

  15. 75 FR 70023 - Outer Continental Shelf (OCS), Western and Central Planning Areas, Gulf of Mexico (GOM) Oil and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... clerical errors in a Notice that published in the Federal Register on November 10, 2010 (75 FR 69122). 1... Central Planning Areas, Gulf of Mexico (GOM) Oil and Gas Lease Sales for the 2007-2012 5-Year OCS Program... Planning Area (CPA) lease sales in the 2007-2012 5-Year OCS Program. The proposed sales are in the Gulf...

  16. Geology and mineral and energy resources, Roswell Resource Area, New Mexico; an interactive computer presentation

    USGS Publications Warehouse

    Tidball, Ronald R.; Bartsch-Winkler, S. B.

    1995-01-01

    This Compact Disc-Read Only Memory (CD-ROM) contains a program illustrating the geology and mineral and energy resources of the Roswell Resource Area, an administrative unit of the U.S. Bureau of Land Management in east-central New Mexico. The program enables the user to access information on the geology, geochemistry, geophysics, mining history, metallic and industrial mineral commodities, hydrocarbons, and assessments of the area. The program was created with the display software, SuperCard, version 1.5, by Aldus. The program will run only on a Macintosh personal computer. This CD-ROM was produced in accordance with Macintosh HFS standards. The program was developed on a Macintosh II-series computer with system 7.0.1. The program is a compiled, executable form that is nonproprietary and does not require the presence of the SuperCard software.

  17. Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

    USGS Publications Warehouse

    Page, W.R.; Harris, A.G.; Poole, F.G.; Repetski, J.E.

    2003-01-01

    New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest. Published by Elsevier Ltd.

  18. Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

    NASA Astrophysics Data System (ADS)

    Page, William R.; Harris, Anita G.; Poole, Forrest G.; Repetski, John E.

    2003-12-01

    New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest.

  19. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1985

    SciTech Connect

    Wiman, W.D.

    1986-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1985 was concentrated in proven petroleum provinces. Successful exploration and development efforts were most intense in Colombia and Venezuela, where activity centered around the Cano Limon field area. Initial production of 30,000 BOPD from Cano Limon started in December, raising Colombia again to the ranks of an exporting nation. Another significant discovery in Colombia was San Francisco field in the Upper Magdalena basin. Argentina reported significant discoveries by YPF in the Northwest Cretaceous and Neuquen basins and by Total offshore Tierra del Fuego. Brazil continued to discover major reserves in the offshore Campos basin in ever-increasing water depths. At year end, Venezuela was drilling Furrial-1 in eastern Venezuela. The well is reported to be the outstanding discovery of 1985, if not of the last 2 decades. 4 figures, 7 tables.

  20. Modeling the Spatial Pattern of Wildfire Ignition and Burned Area in Southern Californian Mediterranean Ecosystems

    NASA Astrophysics Data System (ADS)

    Faivre, N.; Jin, Y.; Goulden, M.; Randerson, J. T.

    2013-12-01

    Wildfire ignition requires a combination of an ignition source and suitable weather and fuel conditions. Models of fire occurrence and burned area provide a good understanding of the physical and climatic factors that constrain and promote fire spread and recurrence, but information on how humans influence ignition patterns and burned area is still lacking at a scale compatible with integrated fire management. We first investigated the relative importance of the physical, climatic, and human factors regulating ignition probability across Southern California. A 30-year exploratory analysis of one-way relationships indicated that distance to roads, distance to housing, and topographic slope were the major determinants of ignition occurrence and frequency. A logistic regression model explained 70% of spatial variability in ignition occurrence (presence or absence of an ignition in each 3 km grid cell) whereas a Poisson-type regression model explained 45% of the spatial variability in ignition frequency in national forests across Southern California. Predicted ignition probability was a key indicator of the spatial variability of burned area, explaining approximately 9% of the variance for Santa Ana fires and 21% of the variance for non-Santa Ana fires across Southern California. In a second step we combined the previous ignition modeling framework with other data sources to model the spatial distribution of burned area. Preliminary results showed that average wind speed alone explained approximately 30% of the spatial variation in burned area from Santa Ana fires. Further integration of the effects of fuel continuity, moisture, and accumulation and their interaction with wind speed and direction improved our spatial assessment of burned area risk in Southern California. Our results may have implications for strategic fire management in the region.

  1. Cadmium in the Coastal Upwelling Area Adjacent to the California Mexico Border

    NASA Astrophysics Data System (ADS)

    Segovia-Zavala, J. A.; Delgadillo-Hinojosa, F.; Alvarez-Borrego, S.

    1998-04-01

    Cadmium concentrations ([Cd]) were measured in samples from the water column of the coastal upwelling zone adjacent to the California - Mexico border. Temperature and nutrient distributions showed an intense upwelling event during our sampling. Lowest [Cd] were found at locations offshore (50 km) (0·03-0·058 nM), whereas the maximum concentrations were found inshore (0·14-0·166 nM). Both nutrients and [Cd] were enriched in coastal waters. Our inshore [Cd] values are about 25% of those reported for waters off central California. This is possibly due to the intrusion of oligotrophic waters from the eastern edge of the North Pacific Central Gyre to the Southern California Bight. Multivariate analysis indicates that high [Cd]s were associated with high phytoplankton biomass, nutrients and low temperature. Our data present no evidence of a [Cd] gradient due to the San Diego and Tijuana sewage discharges, which indicates that they maintain a very local effect.

  2. Holocene relative sea-level changes in the inner Bredefjord area, southern Greenland

    NASA Astrophysics Data System (ADS)

    Sparrenbom, Charlotte J.; Bennike, Ole; Fredh, Daniel; Randsalu-Wendrup, Linda; Zwartz, Dan; Ljung, Karl; Björck, Svante; Lambeck, Kurt

    2013-06-01

    In this paper we present new relative sea-level data from southern Greenland, a key area for understanding the Greenland Ice Sheet (GIS) response to climate change. Within fourteen lakes and marine lagoons from the inner part of Bredefjord (Nordre Sermilik) in southern Greenland, isolations revealed by stratigraphic and palaeoecological analyses are dated and relative sea levels reconstructed. Due to coastal emergence caused by the GIS retreat within the area, the relative sea-level fell rapidly in the early Holocene between at least c. 9600 and c. 7300 cal. yrs BP attaining a rate of 2 cm per year between 9600 and 8000 cal. yrs BP. Spatial variability in relative sea-level changes is show for southern Greenland from a comparison with the Nanortalik and the Qaqortoq areas. The regression occurred about 2000 years later in the inner Bredefjord area, compared to the Nanortalik area, and about 1000 years later compared to the Qaqortoq area. This is a consequence of earlier deglaciation in areas located at the outer coast. Between c. 8000 cal. yrs BP and the present day, relative sea level was lower than today. The lowest relative sea level in the Inner Bredefjord area of between -5.4 and -15 m a.h.a.t. (above highest astronomical tide) was reached between 7000 and 1000 cal. yrs BP. The neoglacial readvance together with the collapse of the Laurentide peripheral bulge is probably responsible for the transgression in the Inner Bredefjord area, as has been indicated from the nearby sites Qaqortoq and Nanortalik. Our relative sea-level reconstructions showing spatial variability within southern Greenland have implications for Glacial Isostatic Adjustment (GIA) modelling and the understanding of the GIS ice sheet dynamics. The early Holocene regression is consistent with the recession of the southern sector of the GIS from the shelf edge at c. 22 000 cal. yrs BP, reaching inland of the present day outer coast by c. 12 000 cal. yrs BP, and its present margin by c. 10 500

  3. [[Characterization of the potential geographical distribution area of parrot species in Yucatan Peninsula, Mexico].

    PubMed

    Plasencia Vázquez, Alexis Herminio; Escalona Segura, Griselda

    2014-12-01

    Psittacidae family is one of the most endangered groups in Mexico, since many of their habitats are disappearing. In this research, we characterized the land cover of the potential geographical distribu- tion area of eight extant parrot species within the Yucatan Peninsula. We used the Maximum Entropy algorithm (MaxEnt) and species historical records. To externally validate the models, we used presence and absence records from field observations (2010-2012). To characterize the distribution area, we used the vegetation and land use maps of INEGI Series IV (2007-2010). The models showed a good performance, according to the values of the area under the curve (AUC), which ranged between 0.88-0.95 with the training data and between 0.82-0.91 with test data. We located most of the species in sites where the models predicted their presence. In the Peninsula, over 76% of the parrots' potential geographical distribution area is forested, except for Amazona oratrix. The subhumid tropical forest is the best represented, and the livestock for land use. The most affected species within the Peninsula are: Amazona farinosa and A. oratrix. The Calakmul Biosphere Reserve is the most important area for parrots' protection in the Peninsula. Knowing the characteristics of distribution areas is an essential part in the establishment of parrots' conservation strategies. PMID:25720184

  4. The Cantarell Breccia System, Southern Gulf Of Mexico: Structural Evolution And Support For An Origin Relarted To The Chixculub Meteorite Impact

    NASA Astrophysics Data System (ADS)

    Ricoy, V.

    2003-04-01

    The Upper Cretaceous within the Campeche Basin, southern Gulf of Mexico hosts a world class petroleum system. Cantarell is the most important reservoir that consists of a complex brecciated carbonate reservoir deposited at or around the Cretaceous-Tertiary boundary. Previous sedimentological studies suggests that the Upper Cretaceous Carbonate breccias found in the Cantarell oilfield system and through the Bay of Campeche, were the result of a catastrophic shelf collapse event triggered by the Chixculub meteorite impact. This work presents new evidence from structural and stratigraphic interpretation of 3D seismic and 2D lines which gives light to features that support the platform collapse model. The reservoir consists of thick (up to 300 m), heterogeneous, monomyctic and polymictic breccias developed at the K-T boundary, and widely distributed throughout the Campeche Basin. The timing, internal architecture, widespread deposition and distance to the platform margin source (over 30 kms) of the breccia unit, combined with a contorted irregular seismic reflector near the base of the Cretaceous carbonate platform, suggests that the geological processes accountable for the emplacement of the breccias relates to the massive catastrophic collapse of the Cretaceous platform as a result of the Chixculub meteorite impact. Structural interpretation of the 3D seismic data, together with well stratigraphic markers unraveled a complex Oligocene-Miocene structural deformation history of the Cantarell field, which resulted in several discrete reservoir blocks partitioned by a complex array of thrusts, normal and reverse faults. It is proposed that the structural deformation of the area controlled to a large extent the distribution of the reservoir properties found in the Cantarell area. This idea is tested using the structural model matched against the well log porosity data.

  5. Lower Devonian tentaculite bed in the Satun area, southern peninsular Thailand

    NASA Astrophysics Data System (ADS)

    Agematsu, Sachiko; Sashida, Katsuo; Salyapongse, Sirot; Sardsud, Apsorn

    2006-05-01

    A Lower Devonian (Emsian) tentaculite fauna including Nowakia acuaria [Richer, R., 1854. Thüringische Tentaculiten. Zeitschr. Deutsch. Geol. Gesellsch. 6, 275-290] occurs in black shale in the basal part of a siliciclastic sequence exposed north of Satun, southern peninsular Thailand. Similar tentaculite beds with Nowakia have been reported from several areas in the Fang, Sri Sawat, and Trang areas of Thailand, the Langkawi Islands and the Mahang-Baling areas of Malaysia. The depositional environments in which the tentaculite-bearing black shale accumulated extended from modern northern Thailand to northwestern Malaysia during the Early Devonian (Emsian).

  6. Assessment of new vehicles emissions certification standards in the metropolitan area of Mexico City.

    PubMed

    Schifter, I; Díaz, L; López-Salinas, E

    2006-03-01

    Light duty gasoline vehicles account for most of CO hydrocarbons and NOx emissions at the Metropolitan Area of Mexico City (MAMC). In order to ameliorate air pollution from the beginning of 2001, Tier 1 emission standards became mandatory for all new model year sold in the country. Car manufacturers in Mexico do not guarantee the performance of their exhaust emissions systems for a given mileage. The purpose of this study was to assess whether the Tier 1 vehicles will stand the certification values for at least 162000 km with the regular fuel available at the MAMC. Mileage accumulation and deterioration show that certified carbon monoxide emissions will stand for the useful life of the vehicles but in the case of non-methane hydrocarbons will be shorter by 40%, and nitrogen oxides emissions above the standard will be reached at one third of the accumulated kilometers. The effect of gasoline sulfur content, on the current in use Tier 1 vehicles of the MAMC and the impact on the emissions inventory in year 2010 showed that 31000 extra tons of NOx could be added to the inventory caused by the failure of the vehicles to control this pollutant at the useful life of vehicles. PMID:16570219

  7. Quantifying the Benefits of Transportation Controls in the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Rojas-Bracho, L.; Fernández-Bremauntz, A.; Zuk, M.; Garibay, V.; Iniestra, R.; Franco, P.

    2004-12-01

    Similar to most large cities, the transportation sector in the Mexico City Metropolitan Area (MCMA) constitutes the largest source of air pollution emissions, which result in significant impacts on human health. Although the majority of MCMA residents use public transportation, the share of trips in private vehicles is rising and these vehicles have become the largest contributor to mobile emissions. To reduce these emissions, there is an urgent need to improve the current fleet, improve the quality of fuels, and modify the paradigm of private car use, by providing clean, safe, efficient and comfortable public transportation options. Here we present the potential human health benefits of a set of five mobile source control measures that span public and private transportation options: Taxi fleet renovation, Hybrid buses, Metro Expansion, and the introduction of low sulfur gasoline and Tier II vehicles. We also discuss the methodology and preliminary results of the analysis of the implementation of the project for a Bus Rapid Transit system in Mexico City, in terms of its impacts on personal exposures, emissions, and public health.

  8. Characteristics of Urban Natural Areas Influencing Winter Bird Use in Southern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Smith, Paul G. R.

    2007-03-01

    Characteristics of urban natural areas and surrounding landscapes were identified that best explain winter bird use for 28 urban natural areas in southern Ontario, Canada. The research confirms for winter birds the importance of area (size) and natural vegetation, rather than managed, horticultural parkland, within urban natural areas as well as percent urban land use and natural habitat in surrounding landscapes. Alien bird density and percent ground feeding species increased with percent surrounding urban land use. Higher percent forest cover was associated with higher percentages of forest, bark feeding, small (<20 g) and insectivorous species. Natural area size (ha) was related to higher species richness, lower evenness and higher percentages of insectivorous, forest interior, area-sensitive, upper canopy, bark feeding, and non-resident species. Higher number of habitat types within natural areas and percent natural habitat in surrounding landscapes were also associated with higher species richness. Common, resident bird species dominated small areas (<6.5 ha), while less common non-residents increased with area, indicative of a nested distribution. Areas at least 6.5 ha and more generally >20 ha start to support some area-sensitive species. Areas similar to rural forests had >25% insectivores, >25% forest interior species, >25% small species, and <5% alien species. Indicator species separated urban natural areas from rural habitats and ordination placed urban natural areas along a gradient between urban development and undisturbed, rural forests. More attention is needed on issues of winter bird conservation in urban landscapes.

  9. Preliminary Source Characterization and Tsunami Modeling of Submarine Landslides along the Yucatan Shelf/Campeche Escarpment, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Chaytor, J. D.; Geist, E. L.; Paull, C. K.; Caress, D. W.; Gwiazda, R.; Fucugauchi, J. U.; Rebolledo-Vieyra, M.

    2014-12-01

    Using high-resolution multibeam bathymetry recently collected by the R/V Falkor, we evaluated the morphology, size, and tsunami-generating potential of a number of large, previously unknown, submarine landslides that excavated sections of the submerged Yucatan Shelf/carbonate platform above the Campeche Escarpment. Landslide evacuations appear to be primarily restricted to the later Cenozoic sections of the margin, removing pelagic sediments deposited above the Cretaceous shallow water carbonates exposed along the face of the escarpment. The largest landslides have evacuated areas of the shelf between 130 and 1,100 km2, possibly removing as much as 70 km3 of material in a single event. Based on the morphology of the evacuated areas, the primary mode of failure appears to be translational and retrogressive, with slide thickness primarily stratigraphically controlled. Displaced material appears to be present within some of the evacuation zones, but because sediments from the Mississippi Fan onlap the base of the Campeche Escarpment, mass-transport deposits from individual landslides have not been identified and therefore run-outs are poorly constrained. The evacuation zones are used to specify the initial conditions for tsunami modeling. Both regional, Gulf of Mexico and near-field simulations are performed to determine the severity and wave-height distribution for six slide scenarios. Preliminary results indicate that the location of maximum wave heights associated with the slide scenarios depend on the direction on down-slope slide movement, although there are significant refraction effects during basin-wide propagation. There is also significant energy dissipation during cross-shelf propagation, with wider shelves lessening the severity of tsunami runup compared to runup at coastal locations adjacent to narrower shelves. Future tsunami hazard assessments in the Gulf of Mexico should account for these large, newly discovered submarine landslides.

  10. Aedes aegypti pupal/demographic surveys in southern Mexico: consistency and practicality.

    PubMed

    Arredondo-Jiménez, J I; Valdez-Delgado, K M

    2006-04-01

    In interventions aimed at the control of the immature stages of Aedes aegypti (L.), the principal vector of the dengue viruses, attempts are often made to treat or manage all larval habitats in households. When there are resource-constraints, however, a concentration of effort on the types of container that produce the most pupae may be required. Identification of these 'key' container types requires surveys of the immature stages and particularly - since these give the best estimates of the numbers of adults produced - of the numbers of pupae in local containers. Although there has been no clearly defined or standardized protocol for the sampling of Ae. aegypti pupae for many years, a methodology for 'pupal/demographic' surveys, which may allow the risk of dengue outbreaks in a given setting to be estimated, has been recently described. The consistency and practicality of using such surveys has now been investigated in three cities in the Mexican state of Chiapas, Mexico. Using a combination of 'quadrat'- and transect-sampling methods, 600 houses in each city were each sampled twice. Containers within each study household were searched for pupae and larvae. Although 107,297 containers, belonging to 26 categories, were observed, only 16,032 were found to contain water and 96% and 92% of these 'wet' containers contained no pupae and no third- or fourth-instar larvae, respectively. Although the random 'quadrat' sampling gave similar results to sampling along transects, there were statistically significant differences in the numbers of pupae according to container type and locality. The most important containers for pupal production were found to be large cement wash basins, which were present in almost every household investigated and from which 84% (10,257/12,271) of all pupae were collected. A focus on this class of container could serve as the basis of a targeted intervention strategy. When traditional Stegomyia indices were calculated they appeared to be

  11. Zonification of Areas Susceptible to Slope Instability in the State of Colima, Mexico

    NASA Astrophysics Data System (ADS)

    Ramirez-Ruiz, J. J.

    2015-12-01

    The Topography of the State of Colima in combination with the tectonic and geographic situation originates vulnerability to the slope instability in the Occidental part of Mexico. This problematic increase in rain Season ( May to November) due to the presence of hurricanes that can produce a great precipitations in a short time period. Likewise the seismicity present in this area due to the tectonic interaction of the tectonic plates (Cocos subducting to the Northamerica) contribute to increase this phenomenology. Here we present the results of zonification using a methodology to estimate the susceptibility areas and a procedure to estimate the probability of occurrent of this phenomena originated by precipitation and seismicity. By zonification of areas we consider topographic, morphologic and geologic factors to determine the category of the areas. . For the risk we consider the Susceptibiliy, Precipitation and Seismicity as will be described here. We consider the Precipitation return period of 2, 5, 10, 50 and 100 years to estimate the risk of slope instability in the State of Colima. We observe that risk increase on this area considering the precipitation return periods of 25, 50 and 100 years and it will be accelerated by the occurrence of seismicity specially by magnitude great than 7 as it occurs at least one time each 5 years.

  12. Ground-Water Hydrology and Water Quality of the Southern High Plains Aquifer, Cannon Air Force Base, Curry County, New Mexico, 1994-2005

    USGS Publications Warehouse

    Langman, Jeff B.; Falk, Sarah E.; Gebhardt, Fredrick E.; Blanchard, Paul J.

    2006-01-01

    In cooperation with the U.S. Air Force, the U.S. Geological Survey has collected hydrologic data about the Southern High Plains aquifer at Cannon Air Force Base in east-central New Mexico since 1994. Under the guidance of the State of New Mexico, ground-water quality of the aquifer has been analyzed as part of annual monitoring at regulated sites at the base. This report provides a summary and interpretation of all available hydrologic data collected by the U.S. Geological Survey for Cannon Air Force Base environmental managers for the regulated sites of Landfill 5 and the Sewage Lagoons between 1994 and 2005. Cannon Air Force Base is in the Southern High Plains physiographic region, and saturated deposits of the Ogallala Formation underlying the base are within the western boundary of the Southern High Plains aquifer. The general direction of ground-water flow in the Southern High Plains aquifer at Cannon Air Force Base is from northwest to southeast. In 1962, ground water predominantly flowed northwest to southeast with minimal change in direction. Ground-water altitudes declined from 1962 to 1997, and a pronounced water-level recession (area of receding water level) developed northwest of the base, altering flow direction in this area. The recession northwest of the base and the subsequent change in direction of ground-water flow are indicative of local ground-water withdrawals upgradient from Cannon Air Force Base. Historical water levels in wells within a 3-mile radius of Cannon Air Force Base declined in 52 of 56 wells for various periods of record between 1962 and 2004. Forty-three of the wells indicated strong linear decreases with time, and the largest decline was 91.80 feet, an average annual decline of about 2.13 feet per year. Water levels in monitoring wells at Cannon Air Force Base reflected the regional decline; water levels declined for all wells with periods of record greater than 1 year, and the decreases were strongly linear. From 1994 to 2005

  13. The Berriasian-Valanginian (Early Cretaceous) boundary transition at Santa Catarina Ticuá, Oaxaca state, southern Mexico: Ammonites, bivalves, calpionellids and their paleobiogeographic significance

    NASA Astrophysics Data System (ADS)

    Zell, Patrick; Stinnesbeck, Wolfgang; Beckmann, Seija; Adatte, Thierry; Hering, Fabio

    2015-10-01

    Ammonites, bivalves and calpionellids of the late Berriasian-early Valanginian from southern Mexico are poorly known; those here described are from the Sabinal Formation at Santa Catarina Ticuá, Oaxaca state. Samples were collected and analyzed bed-by-bed. Ammonite assemblages correlate to the West Mediterranean late Berriasian Subthurmannia boissieri and early Valanginian Thurmanniceras pertransiens and Neocomites neocomiensiformis zones and contain taxa, which are majorly endemic, although a few European species are also identified. The bivalve Arctotis cretacea (Felix, 1891) is common in several horizons throughout the section. Calpionellids are present in the upper part of the Santa Catarina Ticuá section and are indicative of the middle Berriasian Remaniella cadischiana Subzone, the late Berriasian Calpionellopsis Zone (including the Calpionellopsis simplex and Cs. oblonga subzones) and the early Valanginian Calpionellites darderi Subzone. Our data indicate that biogeographic correlation of faunal and environmental changes is possible across the Berriasian-Valanginian boundary between southern Mexico and faunal realms of the southwestern Gulf of Mexico and the western Tethys, and thus throughout the western hemisphere.

  14. Floods of December 1982 to May 1983 in the central and southern Mississippi River and the Gulf of Mexico basins

    USGS Publications Warehouse

    Stone, Roy B.; Bingham, Roy H.

    1991-01-01

    Widespread flooding occurred in December 1982 and in spring 1983 in the central and southern Mississippi River basin. The first series of storms, December 2-7, caused severe flooding along many streams in Illinois, Missouri, and Arkansas. Much of the three-State area experienced recordbreaking 24-hour rainfall amounts that caused some streams to exceed previously known flood heights and discharges; in many cases the recurrence interval of peak discharges exceeded 100 years. The second series of storms, December 24-29, caused severe flooding in Louisiana and moderate flooding in Mississippi. Peak discharges on some streams exceeded the 100-year recurrence interval. Damages exceeded $200 million and 25 persons died as a result of the December storms. Western Tennessee was on the fringes of both storms and received only minor flooding. During April 4-8, 1983, as much as 17 inches of rain fell in parts of southern Mississippi and southeastern Louisiana. In some areas, 24-hour amounts exceeded 5 inches, causing peak discharges to exceed the recurrence interval of 100 years at 20 streamflow gaging stations. In May 1983 heavy and intense rains caused major flooding in the Big Black River and Pearl River basins in Mississippi.

  15. The risk of enteric diseases in young children and environmental indicators in sentinel areas of Mexico City.

    PubMed

    Cifuentes, Enrique; Mazari-Hiriart, Marisa; Carneiro, Fernando; Bianchi, Flavia; Gonzalez, Dolores

    2002-03-01

    The overall objective of this study is to promote the development of environmental health indicators in Mexico City. Specific examples focused on water quality, household characteristics e.g., sanitation and risk of enteric diseases. A geographic information system (GIS) was used in order to identify eligible wells and their surrounding homesteads (0.5 km around each well). A pilot study was conducted during the rainy season (1999), and a total of 1, 250 eligible households were visited on a random sample basis; only those having children under 5 years of age were interviewed. Data on diarrheal disease (i.e. occurrence in the previous two weeks) were obtained from 950 children, and their guardians provided information on their water supply, sanitation and socioeconomic variables. A total of 320 water samples were obtained from 40 wells, and tested for Total coliforms (TC/100 ml), Fecal coliforms (FC/100 ml). Escherichia coli (EC) and Fecal streptococci (FS). Bacterial indicators were detected in 40% of the wells in the western zone and in 32% of the southern zone (p = 0.01). The rate of diarrheal diseases was higher for children from the southern areas than in the west (OR = 1.7 and 95% CI: 0.99, 2.86). The final analysis showed a higher risk of diarrhea in children from rented homes than those living in owned dwellings (OR = 1.7 and 95% Cl: 1.04, 2.77): the risk was also highest for children living in houses with poor sanitation facilities (e.g., latrine) than those connected to a sewerage (OR = 1.7 and 95% Cl: 1.00, 2.93). Children from households perceiving unpleasant taste of water showed a higher risk than those without complaints (OR = 2.2 and 95% Cl: 1.28, 3.75). Linkages between environmental factors and health risk were created from spatially distributed information, and the proposed environmental health indicator (EHI) summarized the most significant predictors of diarrheal diseases. This baseline information may contribute to further environmental health

  16. Oil and gas developments in South America, Central America, Caribbean Area, and Mexico in 1984

    SciTech Connect

    Tappmeyer, D.M.

    1985-10-01

    For the 25 countries described in the region, exploration activity continued to be centered in proven petroleum provinces in 1984. Exploration activity increased in Brazil, Colombia, and Venezuela. Important, successful exploration efforts continued in areas around Cano Limon field in Colombia, and Guafita and La Victoria fields in Venezuela. Notable discoveries in South America included the 42-461X San Martin Cretaceous discovery by Shell in the Ucayali basin in Peru, the significant oil and gas discovery at Palmar Largo ES-1 by YPF in Argentina, and the first offshore gas discovery, the Pecten 1-SPS-20 wildcat in the Santo basin in Brazil. Oil production increased in Barbados, Brazil, Colombia, Ecuador, Mexico, Peru, Trinidad and Tobago, and Venezuela. A notable increase (40%) in oil production occurred in Brazil. Gas production increased in Argentina, Barbados, Colombia, Peru, and Trinidad and Tobago.

  17. Oil and gas developments in South Africa, Central America, Caribbean Area, and Mexico in 1984

    SciTech Connect

    Tappmeyer, D.M.

    1985-10-01

    For the 25 countries described in the region, exploration activity continued to be centered in proven petroleum provinces in 1984. Exploration activity increased in Brazil, Colombia, and Venezuela. Important, successful exploration efforts continued in areas around Cano Limon field in Colombia, and Guafita and La Victoria fields in Venezuela. Notable discoveries in South America included the 42-46-1X San Martin Cretaceous discovery by Shell in the Ucayali basin in Peru, the significant oil and gas discovery at Palmar Largo ES-1 by YPF in Argentina, and the first offshore gas discovery, the Pecten 1-SPS-20 wildcat in the Santo basin in Brazil. Oil production increased in Barbados, Brazil, Colombia, Ecuador, Mexico, Peru, Trinidad and Tobago, and Venezuela. A notable increase (40%) in oil production occurred in Brazil. Gas production increased in Argentina, Barbados, Colombia, Peru, and Trinidad and Tobago. 8 figures, 8 tables.

  18. Oil and gas developments in South America, Central America, Caribbean Area, and Mexico in 1982

    SciTech Connect

    Deal, C.S.

    1983-10-01

    Petroleum developments in the region in 1982 had a more varied pattern than in 1981 when all aspects were upbeat with varying degrees of increases. In 1982, Brazil, Mexico, and Guatemala had striking increases in oil production; Bolivia, Chile, and Colombia had moderate increases; and Argentina, Trinidad, and Venezuela reported declines. In exploration, Argentina reported several additional offshore Tierra del Fuego discoveries in the Cretaceous Springhill and 2 more encouraging gas discoveries in the Noroeste basin. Bolivia reported an oil discovery from Silurian rocks more generally considered a gas objective. Brazil extended and confirmed the Western Amazonas gas area with 2 discoveries. Colombia added 2 more spectacular oil discoveries in the Llanos basin to follow up 2 similar finds in 1981. Several countries reported that discoveries have increased the national reserves of hydrocarbons. Considering the social, political, and economic problems in several countries, along with the worldwide depression and petroleum surplus, developments in the region have been on the whole favorable.

  19. Geology and ground water of the Red Lake area, Navajo Indian Reservation, Arizona and New Mexico

    USGS Publications Warehouse

    Akers, J.P.; McClymonds, N.E.; Harshbarger, John William

    1962-01-01

    The Red Lake area in the Navajo Indian Reservation, Arizona and New Mexico, was studied by the U.S. Geological Survey to determine if 1 mgd (mil- lion gallons per day) of water could be obtained for the requirements of a proposed sawmill. Geologic mapping and stratigraphic studies indicated three favorable areas where ground water may be developed. Test holes were drilled under contract in the areas, and pumping tests indicate that 500,000 gpd (gal- lons per day) is available from alluvium along Tohdildonih Wash near Frog Rock, 100,000 gpd is available from the Shinarump member of the Chinle forma- tion and the De Chelly sandstone near Red Lake, and 800,000 gpd is available from alluvium and cinder beds in lapiUi tuff in Buell Park, an eroded diatreme. The diatreme at Buell Park is about 2% miles in diameter. It was formed by several explosions in which lapilli tuff and cinders were erupted. These materials, together with later basaltic intrusive and extrusive rock, now fill the diatreme. The tuff and cinders are water bearing, 'and they receive re- charge from rainwater and snowmelt moving through overlying alluvium and from storage in the De Chelly sandstone which encloses the east half of the diatreme. The quality of water from all areas is suitable for domestic use. However, special treatment may be necessary to make the water suitable for pulp processing.

  20. Characteristics of the Bab al Mandab-Northern Afar area of the southern Red Sea

    SciTech Connect

    Allen, R.B. ); Sikander, A.H. ); Abouzakhm, A.G.

    1991-08-01

    The southern Red Sea and adjacent Afar area represent an enigmatic portion of the Red Sea/Gulf of Aden basin system. Although the topographic rift shoulders of the Red Sea and Gulf of Aden can be traced through this elbow, and appear to suggest that a similar width for the zone of extension is maintained across the region, the character of the floor of the rift zone changes. The distinctive character of the southern Red Sea-Afar area results in part from a topographically elevated region, possibly associated with the Red Sea-Gulf of Aden-East African rift triple junction. In addition, however, seismic data from offshore Ethiopia suggests that the distinctive character is due a complex pattern of rifting. The central axial trough of the Red Sea decreases in depth to the south toward the strait of Bab al Mandab, suggesting that rifting is dying out southward. Farther to the west at the same latitude, a major but narrow half-graben can be seen on seismic in the Gulf of Zula, bounded to the east by a large west-dipping normal fault. This structure continues south into the Danakil Depression of the Afar area. Between these two en echelon rift trends, the Danakil Alps form a long-lived high. Seismic data from the southern Red Sea of Ethiopia show southward thinning and pinch-out of the Miocene syn-rift evaporite sequence onto the northern Danakil block. Thus, it appears that the Danakil block has largely escaped Red Sea extension and subsidence. Instead, it forms a large unextended terrain located between overlapping en echelon rift trends, and may represent an accommodation zone structure associated with offset in the rift axis of the southern Red Sea.

  1. Space treatments of insecticide for control of dengue virus vector Aedes aegypti in southern Mexico. I. Baseline penetration trials in open field and houses.

    PubMed

    Arrendondo-Jimenez, Juan I; Rivero, Norma E

    2006-06-01

    We studied the efficacy of space ultra-low volume treatments of 3 insecticides for the control of the dengue virus vector Aedes aegypti in southern Mexico. Insecticides tested were permethrin (Aqua-Reslin Super), d-phenothrin (Anvil), and cyfluthrin (Solfac), applied at rates of 10.87, 7.68, and 2 g/ha, respectively, by using London Fog, HP910-PHXL, or Micro-Gen pumps mounted on vehicles. Studies included 1) open field penetration tests and 2) house penetration tests. Open field tests indicated that Anvil and Solfac were more effective than Aqua-Reslin Super. In house tests, Anvil yielded the highest mosquito mortalities (>/=88%) of the three insecticides in the front porch, living room, bedroom, and backyard. Therefore, Anvil proved to be better than other insecticides evaluated to control Ae. aegypti in Chiapas, Mexico. PMID:17019777

  2. Sintacs Aquifer Vulnerability in the Definition of the Natural Protected Area Los Chorros Del Varal, Los Reyes, Michoacan, Mexico

    NASA Astrophysics Data System (ADS)

    Silva, J.; Ramiro, R.; Estrada, F.; Ochoa, S.

    2006-12-01

    In Michoacan State, Mexico, the use of aquifer vulnerability assessment is been incorporated in the regional policies of aquifer protection. A hydrogeological evaluation and aquifer vulnerability assessment using the SINTACS method was done in the natural protected area, NPA, Los Chorros del Varal in Michoacan State, Central Mexico. This place is a discharge area. An spectacular spring is feeding a stream. The predominant rocks are volcanic. By means of the SINTACS method a contamination risk zoning was obtained. The research permitted the expansion of the protection area of Los Chorros del Varal: a surrounding area to avoid anthropogenic impacts. This NPA is the preferential recharge area of the regional aquifer. This aquifer is the main water supply source for more than 200,000 inhabitants. A high to medium vulnerability was calculated. These vulnerable parts must be protected impeding risky projects such as dumps or industries producing wastewaters. Low values were obtained in clayey environments and also in volcanic rocks with scarce fracturing.

  3. Hazard analysis in active landslide areas in the State of Veracruz, Mexico

    NASA Astrophysics Data System (ADS)

    Wilde, Martina; Morales Barrera, Wendy V.; Rodriguez Elizarrarás, Sergio R.; Solleiro Rebolledo, Elizabeth; Sedov, Sergey; Terhorst, Birgit

    2016-04-01

    The year 2013 was characterized by strong storms and hurricanes like the Hurricanes Barbara and Ingrid and the tropical storms Barry and Fernand, which occurred between June and November affecting especially the coastal regions of Mexico. First of all, the State of Veracruz experienced a series of intense rainfalls and as consequences of these events over 780 landslides were registered. More than 45000 people suffered from evacuations. Located on the coast of the Gulf of Mexico, Veracruz has a wide range of altitude differences. The area with the highest elevations reaches from 5675 m.a.s.l. (Pico de Orizaba, the highest mountain of Mexico) to approximately 3000 m.a.s.l. and is characterized by steep slopes and V-shaped valleys. The mountains are part of the Sierra Madre Oriental and the Trans-Mexican Volcanic Belt. Plateaus and rounded hills are typical for the intermediate zones (3000 - 500 m.a.s.l.). The lowest zone (from 500 m.a.s.l. to sea level) is defined by moderate slopes, large rivers and coastal plain areas. The geology shows a variety and complexity of sedimentary and volcanic rocks. The sedimentary formations comprise claystones, siltstones, sandstones and calcareous rocks. Plateaus of basalts and andesites and deposits of ignimbrites are representative for this area. Even though Veracruz is a region highly endangered by landslides, currently there are no susceptibility maps or any other relevant information with high spatial resolution. Because of the lack of high definite information about the landslide hazards in this area, detailed investigations about the conditions (geology, geomorphology, thresholds, etc.) are indispensable. A doctoral grant from the German Academic Exchange Service (DAAD) allowed to carry out investigations in areas affected by large landslides in the year 2013. The selected study sites comprise damaged infrastructures and settlements. With a multi-methodological and interdisciplinary approach different processes and types of

  4. Genetic structure of Plasmodium vivax using the merozoite surface protein 1 icb5-6 fragment reveals new hybrid haplotypes in southern Mexico

    PubMed Central

    2014-01-01

    Background Plasmodium vivax is a protozoan parasite with an extensive worldwide distribution, being highly prevalent in Asia as well as in Mesoamerica and South America. In southern Mexico, P. vivax transmission has been endemic and recent studies suggest that these parasites have unique biological and genetic features. The msp1 gene has shown high rate of nucleotide substitutions, deletions, insertions, and its mosaic structure reveals frequent events of recombination, maybe between highly divergent parasite isolates. Methods The nucleotide sequence variation in the polymorphic icb5-6 fragment of the msp1 gene of Mexican and worldwide isolates was analysed. To understand how genotype diversity arises, disperses and persists in Mexico, the genetic structure and genealogical relationships of local isolates were examined. To identify new sequence hybrids and their evolutionary relationships with other P. vivax isolates circulating worldwide two haplotype networks were constructed questioning that two portions of the icb5-6 have different evolutionary history. Results Twelve new msp1 icb5-6 haplotypes of P. vivax from Mexico were identified. These nucleotide sequences show mosaic structure comprising three partially conserved and two variable subfragments and resulted into five different sequence types. The variable subfragment sV1 has undergone recombination events and resulted in hybrid sequences and the haplotype network allocated the Mexican haplotypes to three lineages, corresponding to the Sal I and Belem types, and other more divergent group. In contrast, the network from icb5-6 fragment but not sV1 revealed that the Mexican haplotypes belong to two separate lineages, none of which are closely related to Sal I or Belem sequences. Conclusions These results suggest that the new hybrid haplotypes from southern Mexico were the result of at least three different recombination events. These rearrangements likely resulted from the recombination between haplotypes of

  5. Development of the Permian-Triassic sequence in the basin Fringe area, southern Netherlands

    SciTech Connect

    Geluk, M.; Van Doorn, D.; Plomp, A.; Duin, E. )

    1993-09-01

    Geological studies in the fringe area of the southern Permian basin led to new insights in the distribution and development of the Permian-Triassic sequence. During the Permian, the fringe area formed a platform, attached to the London-Brabant Massif, while during the Triassic it is characterized by strongly subsiding half grabens. In the southern Netherlands, Rotliegende sandstones and conglomerates have a much wider distribution than previously recognized. The Rotliegende deposits are capped by claystones and carbonates of the Upper Permian Zechstein. In the offshore, an important feeder system of clastics from the London-Brabant Massif was active during deposition of the Rotliegende and the Zechstein. In course of time, the location of major sandstone deposition shifted westward. Deposition of the Triassic Buntsandstein was controlled by the development of a large feeder system, which transported clastics from the Vosges northward, through the Roer Valley Graben and West netherlands Basin into the Off Holland Low. This system was responsible for the deposition of the economically important sheet sandstones of the Volpriehausen, Detfurth, Hardegsen, and Solling formations. A regional unconformity occurs below the Solling Formation. The sandstones are capped by claystones, evaporites, and sandstones of the Rot Formation. During deposition of the Muschelkalk, the differences in subsidence decreased and shallow marine sediments are interbedded with evaporites. Several unconformities occur within the Keuper. In the previous half grabens in the southern Netherlands, the Keuper is incomplete, which may be indicative for a possible reversal of the tectonic movements during this period.

  6. 50 CFR Figure 1 to Subpart G of... - Boundaries of the Statistical Reporting Area in the Southern Ocean

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 11 2012-10-01 2012-10-01 false Boundaries of the Statistical Reporting Area in the Southern Ocean 1 Figure 1 to Subpart G of Part 300 Wildlife and Fisheries INTERNATIONAL... in the Southern Ocean EC01JY91.072...

  7. 50 CFR Figure 1 to Subpart G of... - Boundaries of the Statistical Reporting Area in the Southern Ocean

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 11 2014-10-01 2014-10-01 false Boundaries of the Statistical Reporting Area in the Southern Ocean 1 Figure 1 to Subpart G of Part 300 Wildlife and Fisheries INTERNATIONAL... in the Southern Ocean EC01JY91.072...

  8. 50 CFR Figure 1 to Subpart G of... - Boundaries of the Statistical Reporting Area in the Southern Ocean

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Boundaries of the Statistical Reporting Area in the Southern Ocean 1 Figure 1 to Subpart G of Part 300 Wildlife and Fisheries INTERNATIONAL... in the Southern Ocean EC01JY91.072...

  9. Phylogeographic characteristics of vesicular stomatitis New Jersey viruses circulating in Mexico from 2005 to 2011 and their relationship to epidemics in the United States.

    PubMed

    Velazquez-Salinas, Lauro; Pauszek, Steven J; Zarate, Selene; Basurto-Alcantara, Francisco J; Verdugo-Rodriguez, Antonio; Perez, Andres M; Rodriguez, Luis L

    2014-01-20

    We analyzed the phylogenetic and time-space relationships (phylodynamics) of 181 isolates of vesicular stomatitis New Jersey virus (VSNJV) causing disease in Mexico and the United States (US) from 2005 through 2012. We detail the emergence of a genetic lineage in southern Mexico causing outbreaks in central Mexico spreading into northern Mexico and eventually into the US. That emerging lineage showed higher nucleotide sequence identity (99.5%) than that observed for multiple lineages circulating concurrently in southern Mexico (96.8%). Additionally, we identified 58 isolates from Mexico that, unlike previous isolates from Mexico, grouped with northern Central America clade II viruses. This study provides the first direct evidence for the emergence and northward migration of a specific VSNJV genetic lineage from endemic areas in Mexico causing VS outbreaks in the US. In addition we document the emergence of a Central American VSNJV genetic lineage moving northward and causing outbreaks in central Mexico. PMID:24418533

  10. The checkerboard area health system: delivering comprehensive care in a remote region of New Mexico.

    PubMed

    Reid, R A; Bartlett, E E; Kozoll, R

    1982-01-01

    A comprehensive health center is defined as the synergistic coupling of a medical and administrative structure designed to provide inpatient, outpatient, and public health services. While health centers have been widely established in other countries, only limited implementation has occurred in rural areas of the United States. The successful implementation of the health center concept in a sparsely populated area of northwestern New Mexico, which is predominately inhabited by Navajo Indians and Spanish Americans, is descriptively analyzed. The physical environment and the socioeconomic characteristics of the catchment area residents are related to dominant conditions in underdeveloped countries. The evolution of the delivery system with its network of satellite clinics staffed by mid-level primary care providers is documented. The funding and provision of a wide range of preventive and curative health services supported by communication, transportation, outreach, education, public health, and administration components are described. Several problems thought to impede the application of the health center concept to other regions in the United States are identified and discussed relative to this New Mexican experience. Innovative and persevering systems designers who are strongly committed to delivering a balance between preventive and curative services are considered to be absolutely necessary for successful implementation of the health center concept in the United States. PMID:10255577

  11. Soil mercury levels in the area surrounding the Cerro Prieto geothermal complex, MEXICO.

    PubMed

    Pastrana-Corral, M A; Wakida, F T; García-Flores, E; Rodriguez-Mendivil, D D; Quiñonez-Plaza, A; Piñon-Colin, T D J

    2016-08-01

    Even though geothermal energy is a renewable energy source that is seen as cost-effective and environmentally friendly, emissions from geothermal plants can impact air, soil, and water in the vicinity of geothermal power plants. The Cerro Prieto geothermal complex is located 30 km southeast of the city of Mexicali in the Mexican state of Baja California. Its installed electricity generation capacity is 720 MW, being the largest geothermal complex in Mexico. The objective of this study was to evaluate whether the emissions generated by the geothermal complex have increased the soil mercury concentration in the surrounding areas. Fifty-four surface soil samples were collected from the perimeter up to an approximate distance of 7660 m from the complex. Additionally, four soil depth profiles were performed in the vicinity of the complex. Mercury concentration in 69 % of the samples was higher than the mercury concentration found at the baseline sites. The mercury concentration ranged from 0.01 to 0.26 mg/kg. Our results show that the activities of the geothermal complex have led to an accumulation of mercury in the soil of the surrounding area. More studies are needed to determine the risk to human health and the ecosystems in the study area. PMID:27418073

  12. 77 FR 40081 - Gulf of Mexico, Outer Continental Shelf (OCS), Western Planning Area (WPA) and Central Planning...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... Bureau of Ocean Energy Management Gulf of Mexico, Outer Continental Shelf (OCS), Western Planning Area... Energy Management (BOEM), Interior. ACTION: Notice of availability (NOA) of the Multisale Final...-ROM copy of the Multisale FEIS, you may contact the Bureau of Ocean Energy Management, Gulf of...

  13. Parameterization of ALMANAC crop simulation model for non-irrigated dry bean in semi-arid temperate areas in Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simulation models can be used to make management decisions when properly parameterized. This study aimed to parameterize the ALMANAC (Agricultural Land Management Alternatives with Numerical Assessment Criteria) crop simulation model for dry bean in the semi-arid temperate areas of Mexico. The par...

  14. Alcohol and Drug Use, Abuse, and Dependence in Urban Areas and Colonias of the Texas-Mexico Border

    ERIC Educational Resources Information Center

    Wallisch, Lynn S.; Spence, Richard T.

    2006-01-01

    This study describes the prevalence of alcohol and drug use, abuse, and dependence among adults on the Texas-Mexico border in 2002-2003. The findings are based on survey responses from a random sample of 1,200 adults living in households in three communities: El Paso, a densely populated city in west Texas; the less dense urbanized areas of the…

  15. Late Cretaceous-Oligocene magmatic record in southern Mexico: The case for a temporal slab window along the evolving Caribbean-North America-Farallon triple boundary

    NASA Astrophysics Data System (ADS)

    Ferrari, Luca; Bergomi, Maria; Martini, Michelangelo; Tunesi, Annalisa; Orozco-Esquivel, Teresa; López-Martínez, Margarita

    2014-09-01

    Continental magmatism in southern Mexico is expected to record the eastward displacement of the Farallon-North America-Caribbean triple junction. However, a trench-transversal belt of magmatism in the central western Guerrero State does not fit into a regular pattern of arc migration and reorientation following the formation of the WSW trending Acapulco trench in the Cenozoic. We revised the magmatic pattern of southern Mexico using an updated database and new laser ablation inductively coupled plasma-mass spectrometry sensitive high-resolution ion microprobe, Ar-Ar ages, and geochemical and geologic data for the coastal part of the anomalous Guerrero belt. Our data reveal a persistent magmatic activity between ~75 and 35 Ma, with a changing character at the Paleocene-Eocene boundary (circa 56 Ma). Late Cretaceous-Paleocene granitoids have an adakitic signature imprinted by stable garnet in the source and show no plagioclase fractionation, indicative of wet and oxidized magmas. Eocene rocks consist of an almost bimodal suite of plutonic bodies covered by a succession of mafic lavas. Granitic plutons show plagioclase fractionation and flat middle rare earth element-heavy rare earth element; gabbros have a tholeiitic character, indicative of dryer and more reduced magmas. They appear later and were emplaced at shallow depth in an extensional sedimentary basin. We interpret the magmatic record of the Guerrero belt as the response to two concurrent processes: (1) a temporal window in the Farallon slab induced by the concurrent subduction along the two noncollinear trench segments of southern Mexico (WNW trending) and of the Chortís block (NNW trending) and (2) a scissor-like transtensional rifting associated to counterclockwise rotation and eastward motion of the Chortís block.

  16. Exploratory Investigation of Concentrations of Total Gaseous Mercury in the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Hernandez, S.; de La Rosa, D. A.; Márquez, C.; Solórzano, G.; Martínez, A.

    2004-12-01

    Total Gaseous Mercury (TGM) in ambient air at several locations within Mexico Valley Metropolitan Area (Zona Metropolitana del Valle de México, ZMVM, in Spanish) was measured during the Fall of 2002 and the first quarter of 2003. Among these locations were Tecamachalco (19°26'N; 99°13'W), San Agustín (19°31'N; 99°01'W), Xalostoc (19°31'N; 99°04'W) and Iztapalapa (19°21'N; 99°04'W). San Agustín and Xalostoc border the State of Mexico. Iztapalapa contains CENICA's monitoring station, and Mercury was one of the parameters measured here during the MCMA-2003 field campaign of the atmospheric chemistry taking place in ZMVM in April of 2003. This last site was used to monitor Mercury during three different seasons. The reported concentrations of Mercury vapor were measured continuously using cold vapor Atomic Fluorescence Spectroscopy (Tekran 2537A analyzer), with a detection limit of 0.10 ng·m-3 and a monitoring frequency of five minutes. The average TGM concentrations reported were 13.42, 10.22, 8.46 and 34.2 ng·m-3 for Iztapalapa in the months of September, October and November of 2002 and April of 2003 during the MCMA-2003 field campaign, respectively. For Tecamachalco, a concentration of 49.67 ng·m-3 was reported in January, 11.3 ng·m-3, for San Agustín in February and 31.99 ng·m-3 for Xalostoc in March of 2003.The daily maximums, 24 hourly average, for the same periods are 223.5, 78.2, 31.4 and 503.75 ng·m-3 for Iztapalapa, 118.62 ng·m-3 for Tecamachalco, 83.4 ng·m-3 for San Agustín and 261.2 ng·m-3 for Xalostoc. According to Ontario's air quality standards, the threshold value for mercury vapor in ambient air is 2 mg·m-3 on a 30 day average (Mercury situation in Canada, Report # 2, Environment Canada, May 2002). According to these criteria, then, the data reported for Mexico City are within the allowed limits for ambient air, but still 22 times higher than those reported as background concentrations at pristine locations (de la Rosa D

  17. Formation of semivolatile inorganic aerosols in the mexico city metropolitan area during the milagro campaign

    NASA Astrophysics Data System (ADS)

    Karydis, V. A.; Tsimpidi, A. P.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2011-08-01

    One of the most challenging tasks for chemical transport models (CTMs) is the prediction of the formation and partitioning of the major semi-volatile inorganic aerosol components (nitrate, chloride, ammonium) between the gas and particulate phases. In this work the PMCAMx-2008 CTM, which includes the recently developed aerosol thermodynamic model ISORROPIA-II, is applied in the Mexico City Metropolitan Area in order to simulate the formation of the major inorganic aerosol components. The main sources of SO2 (such as the Miguel Hidalgo Refinery and the Francisco Perez Rios Power Plant) in the Mexico City Metropolitan Area (MCMA) are located in Tula, resulting in high predicted PM1 sulfate concentrations (over 25 μg m-3) in that area. The average predicted PM1 nitrate concentrations are up to 3 μg m-3 (with maxima up to 11 μg m-3) in and around the urban center, mostly produced from local photochemistry. The presence of calcium coming from the Tolteca area (7 μg m-3) as well as the rest of the mineral cations (1 μg m-3 potassium, 1 μg m-3 magnesium, 2 μg m-3 sodium, and 3 μg m-3 calcium) from the Texcoco Lake resulted in the formation of a significant amount of aerosol nitrate in the coarse mode with concentrations up to 3 μg m-3 over these areas. PM1-10 chloride is also high and its concentration exceeds 2 μg m-3 in Texcoco Lake. PM ammonium concentrations peak at the center of Mexico City (2 μg m-3) and the Tula vicinity (2.5 μg m-3). The performance of the model for the major inorganic PM components (sulfate, ammonium, nitrate, chloride, sodium, calcium, and magnesium) is encouraging. At T0, the average measured values of PM1 sulfate, nitrate, ammonium, and chloride are 3.6 μg m-3, 3.6 μg m-3, 2.1 μg m-3, and 0.35 μg m-3 respectively. The corresponding predicted values are 3.7 μg m-3, 2.8 μg m-3, 1.7 μg m-3, and 0.25 μg m-3. Additional improvements are possible by (i) using a day-dependent emission inventory, (ii) improving the performance of

  18. Longitudinal Study of Microbial Diversity and Seasonality in the Mexico City Metropolitan Area Water Supply System

    PubMed Central

    Mazari-Hiriart, Marisa; López-Vidal, Yolanda; Ponce-de-León, Sergio; Calva, Juan José; Rojo-Callejas, Francisco; Castillo-Rojas, Gonzalo

    2005-01-01

    In the Mexico City metropolitan area (MCMA), 70% of the water for 18 million inhabitants is derived from the Basin of Mexico regional aquifer. To provide an overview of the quality of the groundwater, a longitudinal study was conducted, in which 30 sites were randomly selected from 1,575 registered extraction wells. Samples were taken before and after chlorine disinfection during both the rainy and dry seasons (2000-2001). Microbiological parameters (total coliforms, fecal coliforms, streptococci, and Vibrio spp.), the presence of Helicobacter pylori, and physicochemical parameters, including the amount of trihalomethanes (THMs), were determined. Although microorganisms and inorganic and organic compounds were evident, they did not exceed current permissible limits. Chlorine levels were low, and the bacterial counts were not affected by chlorine disinfection. Eighty-four bacterial species from nine genera normally associated with fecal contamination were identified in water samples. H. pylori was detected in at least 10% of the studied samples. About 40% of the samples surpassed the THM concentration allowed by Mexican and U.S. regulations, with levels of chloroform being high. The quality of the water distributed to the MCMA varied between the rainy and dry seasons, with higher levels of pH, nitrates, chloroform, bromodichloromethane, total organic carbon, and fecal streptococci during the dry season. This study showed that the groundwater distribution system is susceptible to contamination and that there is a need for a strict, year-round disinfection strategy to ensure adequate drinking-water quality. This situation in one of the world's megacities may reflect what is happening in large urban centers in developing countries which rely on a groundwater supply. PMID:16151096

  19. Selective and conventional house-spraying of DDT and bendiocarb against Anopheles pseudopunctipennis in southern Mexico.

    PubMed

    Casas, M; Torres, J L; Bown, D N; Rodríguez, M H; Arredondo-Jiménez, J I

    1998-12-01

    Indoor feeding behaviors and mortalities of Anopheles pseudopunctipennis females were evaluated following contact with selective (bands covering mosquitoes' preferred resting areas) and full applications of DDT and bendiocarb on indoor sprayable surfaces. The DDT residues provoked strong avoidance behavior. To a lesser degree, mosquitoes were also repelled by bendiocarb-sprayed surfaces. Because of strong irritancy/repellency, unfed mosquitoes were driven outdoors in proportionally higher numbers. The resting time on selectively or fully DDT-sprayed huts was greatly reduced in comparison to bendiocarb-sprayed huts. Although unfed mosquitoes tended to rest on non-DDT-sprayed surfaces in the selectively treated hut, the man-biting rate was similar with both types of treatments. Unfed mosquitoes were repelled less from selectively bendiocarb-treated surfaces. Similar reductions in postfed resting times were observed on all surfaces suggesting that once fed, mosquitoes rested on sprayed surfaces for shorter intervals of time. Engorged mosquitoes had normal resting behavior (pre- and postspray) within the range of preferred resting heights in both DDT- and bendiocarb-sprayed huts, but the proportion of mosquitoes fed in the DDT-treated huts was lower. Selective spraying of walls was as effective as spraying the complete walls with both insecticides, but DDT was more effective in reducing mosquito-human contact. These studies show that by more effectively targeting vector behavior, a cost-effective alternative to traditional control techniques can be achieved. PMID:10084135

  20. Assessment of tsunami hazard for the American Pacific coast from southern Mexico to northern Peru

    NASA Astrophysics Data System (ADS)

    Brizuela, B.; Armigliato, A.; Tinti, S.

    2013-06-01

    Central America has been struck by at least 49 tsunamis between 1539 and 1996. As many as 37 of these events occurred at the Pacific Coast, and 31 were generated by earthquakes. Some of the events have been destructive, but despite this, tsunamis are an underrated hazard in Central America: people are not aware that they are at risk and even recent tsunami events have been forgotten. Recent studies, following the destructive tsunami occurred in Nicaragua in 1992, have revealed that Central America is a moderately tsunamigenic zone that is mainly affected by tsunamis triggered by earthquakes, especially at the Pacific coast where the Middle American Trench runs parallel to the coast. In this study, a statistical first and then a deterministic analysis for the Pacific coast of Central America has been carried out. The statistical approach aims to estimate the Gutenberg-Richter coefficients of the main seismic tsunamigenic regions of the area in order to assess the annual rate of occurrence of tsunamigenic earthquakes and their corresponding return period. A deterministic approach is then used to compute the tsunami run-up distribution along the coast corresponding to a given annual rate of occurrence of tsunamigenic earthquakes.

  1. Vertical segregation of holoplanktonic molluscs in the epipelagic layer, southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Sanvicente-Añorve, L.; Lemus-Santana, E.; Flores-Coto, C.; Alatorre-Mendieta, M.

    2013-06-01

    The small-scale vertical distribution of five genera of holoplanktonic molluscs inhabiting the upper oceanic layer (0-105 m) was analysed to test whether evident distribution patterns could be attributed to habitat partitioning. Zooplankton samples were taken over neritic waters during the day and night using a 505-μm multiple closing net at five levels (0-6, 6-12, 12-18, 45-55 and 95-105 m) of the water column. Flowmeters were placed in each net to estimate the amount of filtered water. From the 55,654 identifiable specimens of holoplanktonic molluscs, only 6.2 % were in juvenile stage, and Cavolinia, Diacavolinia, Diacria, Oxygyrus and Clio were the most abundant genera. Adults of these genera comprised 3 % of the total abundance. The abundance data were examined using a spatial segregation index, and its significance was tested with null model methods based on Monte Carlo randomizations. Results indicated that adults showed a much more overlapped distribution in the water column than the in the earlier stages. Indeed, juveniles of Cavolinia, Diacavolinia and Oxygyrus were mainly found in the 0-18-m layer, whereas Diacria and Clio were recorded in the 45-105-m stratum. Null model arguments revealed a significant vertical segregation among them. Potential ecological factors involve preferential spawning areas of adults, avoidance of competition for feeding and spatial resources, use of visual capabilities in searching prey, brood protection and avoidance of strong turbulence conditions.

  2. Formation of semivolatile inorganic aerosols in the Mexico City Metropolitan Area during the MILAGRO campaign

    NASA Astrophysics Data System (ADS)

    Karydis, V. A.; Tsimpidi, A. P.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2011-12-01

    One of the most challenging tasks for chemical transport models (CTMs) is the prediction of the formation and partitioning of the major semi-volatile inorganic aerosol components (nitrate, chloride, ammonium) between the gas and particulate phases. In this work the PMCAMx-2008 CTM, which includes the recently developed aerosol thermodynamic model ISORROPIA-II, is applied in the Mexico City Metropolitan Area in order to simulate the formation of the major inorganic aerosol components. The main sources of SO2 (such as the Miguel Hidalgo Refinery and the Francisco Perez Rios Power Plant) in the Mexico City Metropolitan Area (MCMA) are located in Tula, resulting in high predicted PM1 (particulate matter with diameter less than 1 μm) sulfate concentrations (over 25 μg m-3) in that area. The average predicted PM1 nitrate concentrations are up to 3 μg m-3 (with maxima up to 11 μg m-3) in and around the urban center, mostly produced from local photochemistry. The presence of calcium coming from the Tolteca area (7 μg m-3) as well as the rest of the mineral cations (1 μg m-3 potassium, 1 μg m-3 magnesium, 2 μg m-3 sodium, and 3 μg m-3 calcium) from the Texcoco Lake resulted in the formation of a significant amount of aerosol nitrate in the coarse mode with concentrations up to 3 μg m-3 over these areas. PM1-10 (particulate matter with diameter between 1 and 10 μm) chloride is also high and its concentration exceeds 2 μg m-3 in Texcoco Lake. PM1 ammonium concentrations peak at the center of Mexico City (2 μg m-3) and the Tula vicinity (2.5 μg m-3). The performance of the model for the major inorganic PM components (sulfate, ammonium, nitrate, chloride, sodium, calcium, and magnesium) is encouraging. At the T0 measurement site, located in the Mexico City urban center, the average measured values of PM1 sulfate, nitrate, ammonium, and chloride are 3.5 μg m-3, 3.5 μg m-3, 2.1 μg m-3, and 0.36 μg m-3, respectively. The corresponding predicted values are 3.7

  3. Current (2004-07) Conditions and Changes in Ground-Water Levels from Predevelopment to 2007, Southern High Plains Aquifer, Southeast New Mexico-Lea County Underground Water Basin

    USGS Publications Warehouse

    Tillery, Anne

    2008-01-01

    The Southern High Plains aquifer is the principal aquifer and primary source of water in southeastern New Mexico. The Lea County portion of the aquifer covers approximately the northern two thirds of the 4,393-square-mile county. Successful water-supply planning for New Mexico's Southern High Plains requires knowledge of the current aquifer conditions and a context from which to estimate future trends given current aquifer-management policy. Maps representing water-level declines, current (2007) water levels, aquifer saturated thickness, and depth to water accompanied by hydrographs from representative wells for the Southern High Plains aquifer in the Lea County Underground Water Basin were prepared in cooperation with the New Mexico Office of the State Engineer. Results of this mapping effort show the water level has declined as much as 97 feet in the Lea County Underground Water Basin from predevelopment (1914-54) to 2007 with rates as high as 0.88 feet per year.

  4. Salt deposits in Los Medanos area, Eddy and Lea counties, New Mexico

    USGS Publications Warehouse

    Jones, C.L.; with sections on Ground water hydrology, Cooley, Maurice E.; and Surficial Geology, Bachman, George Odell

    1973-01-01

    The salt deposits of Los Medanos area, in Eddy and Lea Counties, southeastern New Mexico, are being considered for possible use as a receptacle for radioactive wastes in a pilot-plant repository. The salt deposits of the area. are in three evaporite formations: the Castile, Salado, and Rustler Formations, in ascending order. The three formations are dominantly anhydrite and rock salt, but some gypsum, potassium ores, carbonate rock, and fine-grained clastic rocks are present. They have combined thicknesses of slightly more than 4,000 feet, of which roughly one-half belongs to the Salado. Both the Castile and the Rustler are-richer in anhydrite-and poorer in rock salt-than the Salado, and they provide this salt-rich formation with considerable Protection from any fluids which might be present in underlying or overlying rocks. The Salado Formation contains many thick seams of rock salt at moderate depths below the surface. The rock salt has a substantial cover of well-consolidated rocks, and it is very little deformed structurally. Certain geological details essential for Waste-storage purposes are unknown or poorly known, and additional study involving drilling is required to identify seams of rock salt suitable for storage purposes and to establish critical details of their chemistry, stratigraphy, and structure.

  5. Description of piezometers installed in the Duranes well field area, Albuquerque, New Mexico

    USGS Publications Warehouse

    Thorn, C.R.

    1998-01-01

    Since 1993, the aquifer system in the Middle Rio Grande Basin, and particularly in the Albuquerque area, has been the focus of studies to further define the extent of the most productive parts of the aquifer and to gain a better understanding of ground-water/surface-water interactions. Twenty-one piezometers were installed during January and February 1997 at five sites in the Duranes well field area in Albuquerque, New Mexico, to allow for concentrated collection of hydraulic-head data. This concentrated collection of shallow hydraulic-head data may lead to a better understanding of the effects of ground-water production on the Rio Grande near a City of Albuquerque well field. Each piezometer was installed in a hole augered by a rig using hollow-stem auger flights. All piezometers are constructed of flush-joint polyvinyl chloride casing with 5-foot polyvinyl chloride screens. The uppermost 2 feet of the piezometer casing is covered by a steel casing with a locking lid. Driller's logs and geophysical logs were collected from the deepest hole and piezometer, respectively, at each site. This report describes the piezometers installed and presents initial water- level data for all piezometers.

  6. Environmental geochemistry for surface and subsurface waters in the Pajarito Plateau and outlying areas, New Mexico

    SciTech Connect

    Blake, W.D.; Goff, F.; Adams, A.I.; Counce, D.

    1995-05-01

    This report provides background information on waters in the Los Alamos and Santa Fe regions of northern New Mexico. Specifically, the presented data include major element, trace element, and isotope analyses of 130 water samples from 94 different springs, wells, and water bodies in the area. The region considered in this study extends from the western edge of the Valles Caldera to as far east as Santa Fe Lake. For each sample, the presented analysis includes fourteen different major elements, twenty-six trace elements, up to five stable isotopes, and tritium. In addition, this data base contains certain characteristics of the water that are calculated from the aforementioned raw data, including the water`s maximum and minimum residence times, as found from tritium levels assuming no contamination, the water`s recharge elevation, as found from stable isotopes, and the charge balance of the water. The data in this report are meant to provide background information for investigations in groundwater hydrology and geochemistry, and for environmental projects. For the latter projects, the presented information would be useful for determining the presence of contamination it any one location by enabling one to compare potential contaminant levels to the background levels presented here. Likely locations of interest are those possibly effected by anthropogenic activities, including locations in and around Los Alamos National Laboratory, White Rock Canyon, and developed areas in the Rio Grande Valley.

  7. The Natural Background Gamma Radiation Exposure in the Metropolitan Area of the Valley of Mexico.

    NASA Astrophysics Data System (ADS)

    Jones, Mary Feild

    Measurements of the natural background radiation have been made at numerous places throughout the world. Very little work in this field has been done in developing countries. In Mexico the natural radiation to which the population is exposed has not been assessed. This dissertation represents a pioneer study in this environmental area. The radiation exposure which occupants within buildings receive as a result of naturally occurring radionuclides present in construction materials is the principal focus. Data were collected between August 1979 and November 1980. Continuous monitoring was done with TLDs placed on site for periods of 3 to 6 months. The instrumentation used for "real-time" measurements was a portable NaI (Tl) scintillation detector. In addition, radiometric measurements were performed on construction materials commonly used in Mexican homes. Based on TLD readings taken within 75 dwellings, the typical indoor exposure for a resident of the study area is 9.2 (mu)Rh('-1). The average reading of the 152 indoor scintillometer surveys was 9.5 (mu)Rh('-1), the outdoor reading 7.5 (mu)Rh('-1). Results of one-way and multi-way analyses of the exposure data to determine the effect due to building materials type, geologic subsoil, age of dwelling, and elevation are also presented. The results of 152 indoor scintillometer surveys are described.

  8. New Magnetic and Geochemical Results on Topsoils of the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Martínez-Pichar, E.; Soler-Arechalde, A. M.; Morton, O.; Hernandez, E.; Lozano-Santa-Cruz, R.; Gonzalez, G.; Beramendi, L.; Urrutia-Fucugauchi, J. H.

    2008-05-01

    The Metropolitan Area of Mexico city is a region well known for intense industrial and commercial activity. The potential sources of the heavy metal pollutants are assumed to be petroleum processing, production of iron material, manufacturing, coal combustion, commercial and automobile exhaust. New samples were collected from industrial, roadside, residential and public parks in the urban areas around the city and added to two previous field campaigns (2003 and 2005). Localities selected for the study represent, presumably, different heavy metal pollution levels and sources. At each sampling point, the top 2 cm layer of the soil profile was collected with a stainless steel trowel and stored in a plastic bag. The elements Fe, Cu and Zn concentrations were determined by EDXRF (Philips PW1400 apparatus) on bulk- sample pressed, boric-acid backed pellets. Metal concentrations of Pb, Ni, Cr, and V were analyzed by ICP-MS with a VG Elemental PQ3 instrument. Magnetic mineralogy in bulk soil samples was investigated by low-field susceptibility using a Kappabridge KLY2. Remanent magnetizations (ARM and IRM) and Hysteresis loops of micro samples had been carried out at room temperature. Bivariate analysis on different ratios of magnetic parameters was employed to characterize the pollution sources.

  9. Radiocarbon ages of lacustrine deposits in volcanic sequences of the Lomas Coloradas area, Socorro Island, Mexico

    NASA Technical Reports Server (NTRS)

    Farmer, J. D.; Farmer, M. C.; Berger, R.

    1993-01-01

    Extensive eruptions of alkalic basalt from low-elevation fissures and vents on the southern flank of the dormant volcano, Cerro Evermann, accompanied the most recent phase of volcanic activity on Socorro Island, and created the Lomas Coloradas, a broad, gently sloping terrain comprising the southern part of the island. We obtained 14C ages of 4690 +/- 270 BP (5000-5700 cal BP) and 5040 +/- 460 BP (5300-6300 cal BP) from lacustrine deposits that occur within volcanic sequences of the lower Lomas Coloradas. Apparently, the sediments accumulated within a topographic depression between two scoria cones shortly after they formed. The lacrustine environment was destroyed when the cones were breached by headward erosion of adjacent stream drainages. This was followed by the eruption of a thin basaltic flow from fissures near the base of the northernmost cone. The flow moved downslope for a short distance and into the drainages that presently bound the study area on the east and west. The flow postdates development of the present drainage system and may be very recent. Our 14C data, along with historical accounts of volcanic activity over the last century, including submarine eruptions that occurred a few km west of Socorro in early 1993, underscore the high risk for explosive volcanism in this region and the need for a detailed volcanic hazards plan and seismic monitoring.

  10. Radiocarbon ages of lacustrine deposits in volcanic sequences of the Lomas Coloradas area, Socorro Island, Mexico

    SciTech Connect

    Farmer, J.D. ); Farmer, M.C. . Dept. of Geography and Anthropology); Berger, R. . Depts. of Geography and Anthropology and Institute of Geophysics and Planetary Sciences)

    1993-01-01

    Extensive eruptions of alkalic basalt from low-elevation fissures and vents on the southern flank of the dormant volcano, Cerro Evermann, accompanied the most recent phase of volcanic activity on Socorro Island, and created the Lomas Coloradas, a broad, gently sloping terrain comprising the southern part of the island. The authors obtained [sup 14]C ages of 4690 [plus minus] 270 Bp (5000-5700 cal Bp) and 5040 [plus minus] 460 Bp (53090-6300 cal Bp) from lacustrine deposits that occur within volcanic sequences of the lower Lonas Coloradas. Apparently, the sediments accumulated within a topographic depression between two scoria cones shortly after they formed. The lacustrine environment was destroyed when the cones were breached by headward erosion of adjacent stream drainages. This was followed by the eruption of a thin basaltic flow from fissures near the base of the northernmost cone. The flow moved downslope for a short distance and into the drainages that presently bound the study area on the east and west. The flow postdates development of the present drainage system and may be very recent. These [sup 14]C data, along with historical accounts of volcanic activity over the last century, including submarine eruptions that occurred a few km west of Socorro in early 1993, underscore the high risk for explosive volcanism in the region and the need for a detailed volcanic hazards plan and seismic monitoring.

  11. Radiocarbon ages of lacustrine deposits in volcanic sequences of the Lomas Coloradas area, Socorro Island, Mexico.

    PubMed

    Farmer, J D; Farmer, M C; Berger, R

    1993-01-01

    Extensive eruptions of alkalic basalt from low-elevation fissures and vents on the southern flank of the dormant volcano, Cerro Evermann, accompanied the most recent phase of volcanic activity on Socorro Island, and created the Lomas Coloradas, a broad, gently sloping terrain comprising the southern part of the island. We obtained 14C ages of 4690 +/- 270 BP (5000-5700 cal BP) and 5040 +/- 460 BP (5300-6300 cal BP) from lacustrine deposits that occur within volcanic sequences of the lower Lomas Coloradas. Apparently, the sediments accumulated within a topographic depression between two scoria cones shortly after they formed. The lacrustine environment was destroyed when the cones were breached by headward erosion of adjacent stream drainages. This was followed by the eruption of a thin basaltic flow from fissures near the base of the northernmost cone. The flow moved downslope for a short distance and into the drainages that presently bound the study area on the east and west. The flow postdates development of the present drainage system and may be very recent. Our 14C data, along with historical accounts of volcanic activity over the last century, including submarine eruptions that occurred a few km west of Socorro in early 1993, underscore the high risk for explosive volcanism in this region and the need for a detailed volcanic hazards plan and seismic monitoring. PMID:11539414

  12. Land-use change, deforestation, and peasant farm systems: A case study of Mexico's Southern Yucatan Peninsular Region

    NASA Astrophysics Data System (ADS)

    Vance, Colin James

    This dissertation develops spatially explicit econometric models by linking Thematic Mapper (TM) satellite imagery with household survey data to test behavioral propositions of semi-subsistence farmers in the Southern Yucatan Peninsular Region (SYPR) of Mexico. Covering 22,000 km2, this agricultural frontier contains one of the largest and oldest expanses of tropical forests in the Americas outside of Amazonia. Over the past 30 years, the SYPR has undergone significant land-use change largely owing to the construction of a highway through the region's center in 1967. These landscape dynamics are modeled by exploiting a spatial database linking a time series of TM imagery with socio-economic and geo-referenced land-use data collected from a random sample of 188 farm households. The dissertation moves beyond the existing literature on deforestation in three principal respects. Theoretically, the study develops a non-separable model of land-use that relaxes the assumption of profit maximization almost exclusively invoked in studies of the deforestation issue. The model is derived from a utility-maximizing framework that explicitly incorporates the interdependency of the household's production and consumption choices as these affect the allocation of resources. Methodologically, the study assembles a spatial database that couples satellite imagery with household-level socio-economic data. The field survey protocol recorded geo-referenced land-use data through the use of a geographic positioning system and the creation of sketch maps detailing the location of different uses observed within individual plots. Empirically, the study estimates spatially explicit econometric models of land-use change using switching regressions and duration analysis. A distinguishing feature of these models is that they link the dependent and independent variables at the level of the decision unit, the land manager, thereby capturing spatial and temporal heterogeneity that is otherwise

  13. Shallow structure of the Chichinautzin Range, southern Mexico basin, central Trans-Mexican Volcanic Belt. A gravity and seismic study

    NASA Astrophysics Data System (ADS)

    Campos-Enriquez, J. O.; Lermo-Samaniego, J. F.; Antahyua-Vera, Y. T.; Chavacan, M.; Ramón, V. M.; Hernández-García; Pita, C.

    2013-12-01

    Chichinautzin Range (ChR) closes to the S the Mexico Basin (MB). Initially based on height differences between MB and the to-he S-located Morelos Plataform (MP) , a major S-dipping fault was proposed. Depths differences to the limestone basement beneath MB and MP respectively supported its existence. This assumed fault was named La Pera. Earlier studies reported the existence of several faults affecting the ChR. New studies were focused to analyze the cinematic and dynamic character of faults to the W of ChR (Tenango Fault System) and of southern Sierra de la Cruces Range. Also based on a gravity study (Campos-Enríquez et al., 2000), the existence of a major N-dipping fault was inferred to delimit the MB to the S (i.e., delimiting the ChR to the N). Our study is based on gravity modelling, and local seismicity analysis. Accordingly, Mezosoic sandstones above metamorphic rocks constitute the basement underlying ChR. This structural high is faulted to the N and S. To the N, fault blocks displace the basement to larger depths (2-4 km). To the S the basement is shallower. The faults of the gravity model correlate with all reported faults, which collectively are refferred to as Aztlan Fault System. Two N-S MT profiles confirm the model. Several of these faults are associated with seismic activity with a N-S extension and a left-lateral component. The seismic event were located at depths of 7-15 km (i.e. the brittle crust). The system can be traced from the Nevado de Tolca volcano up to the Popocatépetl volcano and even further eastwards. The system is about 200 km long, 30-40 km wide, tectonically active. It enabled the fast emplacement of the ChR volcanic rocs. A flower-type structure was inferred to the S of ChR, further south, the profile is cut by faults belonging either to the Taxco-San Miguel de Allende Fault System or to the Chapala-Oaxaca Fault System. This profile shows how the transpressive tectonics, to the S, accomodates, with the N-S extension affecting

  14. Gulf of Mexico Region - Highlighting Low-Lying Areas Derived from USGS Digital Elevation Data

    USGS Publications Warehouse

    Kosovich, John J.

    2008-01-01

    In support of U.S. Geological Survey (USGS) disaster preparedness efforts, this map depicts a color shaded relief representation of the area surrounding the Gulf of Mexico. The first 30 feet of relief above mean sea level are displayed as brightly colored 5-foot elevation bands, which highlight low-elevation areas at a coarse spatial resolution. Standard USGS National Elevation Dataset (NED) 1 arc-second (nominally 30-meter) digital elevation model (DEM) data are the basis for the map, which is designed to be used at a broad scale and for informational purposes only. The NED data were derived from the original 1:24,000-scale USGS topographic map bare-earth contours, which were converted into gridded quadrangle-based DEM tiles at a constant post spacing (grid cell size) of either 30 meters (data before the mid-1990s data) or 10 meters (mid-1990s and later data). These individual-quadrangle DEMs were then converted to spherical coordinates (latitude/longitude decimal degrees) and edge-matched to ensure seamlessness. Approximately one-half of the area shown on this map has DEM source data at a 30-meter resolution, with the remaining half consisting of 10-meter contour-derived DEM data or higher-resolution LIDAR data. Areas below sea level typically are surrounded by levees or some other type of flood-control structures. State and county boundary, hydrography, city, and road layers were modified from USGS National Atlas data downloaded in 2003. The NED data were downloaded in 2005.

  15. A revised Litostragraphic Framework for the Southern Yucca Mountain Area, Nye County, Nevada

    SciTech Connect

    R.W. Spengler; F.M. Byers; R.P. Dickerson

    2006-03-24

    An informal, revised lithostratigraphic framework for the southern Yucca Mountain area, Nevada has been developed to accommodate new information derived from subsurface investigations of the Nye County Early Warning Drilling Program. Lithologies penetrated by recently drilled boreholes at locations between Stagecoach Road and Highway 95 in southern Nye County include Quaternary and Pliocene alluvium and alluvial breccia, Miocene pyroclastic flow deposits and intercalated lacustrine siltstone and claystone sequences, early Miocene to Oligocene pre-volcanic sedimentary rocks, and Paleozoic strata. Of the 37 boreholes currently drilled, 21 boreholes have sufficient depth, spatial distribution, or traceable pyroclastic flow, pyroclastic fall, and reworked tuff deposits to aid in the lateral correlation of lithostrata. Medial and distal parts of regional pyroclastic flow deposits of Miocene age can be correlated with the Timber Mountain, Paintbrush, Crater Flat, and Tram Ridge Groups. Rocks intercalated between these regional pyroclastic flow deposits are substantially thicker than in the central part of Yucca Mountain, particularly near the downthrown side of major faults and along the southern extent of exposures at Yucca Mountain.

  16. A revised lithostratigraphic framework for the southern Yucca Mountain area, Nye County, Nevada

    USGS Publications Warehouse

    Spengler, R.W.; Byers, F.M.; Dickerson, R.P.

    2006-01-01

    An informal, revised lithostratigraphic framework for the southern Yucca Mountain area, Nevada has been developed to accommodate new information derived from subsurface investigations of the Nye County Early Warning Drilling Program. Lithologies penetrated by recently drilled boreholes at locations between Stagecoach Road and Highway 95 in southern Nye County include Quaternary and Pliocene alluvium and alluvial breccia, Miocene pyroclastic flow deposits, Miocene intercalated lacustrine siltstone and claystone sequences, early Miocene to Oligocene pre-volcanic sedimentary rocks, and Paleozoic strata. Of the 37 boreholes currently drilled, 21 boreholes have sufficient depth, spatial distribution, or traceable pyroclastic flow, pyroclastic fall, and reworked tuff deposits to aid in the lateral correlation of lithostrata. Medial and distal parts of regional pyroclastic flow deposits of Miocene age can be correlated with the Timber Mountain, Paintbrush, Crater Flat, and Tram Ridge Groups. Rocks intercalated between these regional pyroclastic flow deposits are substantially thicker than in the central part of Yucca Mountain, particularly near the downthrown side of major faults and along the southern extent of exposures at Yucca Mountain.

  17. SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl - first science from the pilot region

    NASA Astrophysics Data System (ADS)

    Dawson, J. R.; Walsh, A. J.; Jones, P. A.; Breen, S. L.; Cunningham, M. R.; Lowe, V.; Jones, C.; Purcell, C.; Caswell, J. L.; Carretti, E.; McClure-Griffiths, N. M.; Ellingsen, S. P.; Green, J. A.; Gómez, J. F.; Krishnan, V.; Dickey, J. M.; Imai, H.; Gibson, S. J.; Hennebelle, P.; Lo, N.; Hayakawa, T.; Fukui, Y.; Mizuno, A.

    2014-04-01

    The Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) is a sensitive, unbiased, and fully sampled survey of the southern Galactic plane and Galactic Centre in all four ground-state transitions of the hydroxyl (OH) radical. The survey provides a deep census of 1612-, 1665-, 1667-, and 1720-MHz OH absorption and emission from the Galactic interstellar medium, and is also an unbiased search for maser sources in these transitions. We present here first results from the SPLASH pilot region, which covers Galactic longitudes 334° to 344° and latitudes ±2°. Diffuse OH is widely detected in all four transitions, with optical depths that are always small (averaged over the Parkes beam), and with departures from local thermodynamic equilibrium common even in the 1665- and 1667-MHz main lines. To a 3σ sensitivity of ˜30 mK, we find no evidence of OH envelopes extending beyond the CO-bright regions of molecular cloud complexes, and conclude that the similarity of the OH excitation temperature and the level of the continuum background is at least partly responsible for this. We detect masers and maser candidates in all four transitions, approximately 50 per cent of which are new detections. This implies that SPLASH will produce a substantial increase in the known population of ground-state OH masers in the southern Galactic plane.

  18. Ionian marine terraces of southern Italy: Insights into the Quaternary tectonic evolution of the area

    NASA Astrophysics Data System (ADS)

    Caputo, R.; Bianca, M.; D'Onofrio, R.

    2010-08-01

    New detailed morphotectonic analyses of a well exposed flight of marine terraces along the Ionian coast of southern Italy has been carried out. The area represents a key transect for investigating the middle-late Quaternary evolution of the Southern Apennines chain-foredeep-foreland geodynamic system. A major result of the research is the reconstruction of a virtually complete 3D geometry of the marine surfaces along a coastal sector of ca. 70 km, which (1) documents the occurrence of 18 paleo-shorelines and (2) provides evidence for a strong regional uplift affecting the investigated area. Following a systematic critical review of literature relating to geochronological data, integrated with a morphogenetic model based on the interaction between tectonic uplift and eustatic sea level changes, the different terraces are correlated to as many highstand sea level peaks, dating the highest/oldest terrace to ca. 600 ka (MIS 15). The vertical and horizontal distribution of the terraces show a general convergence of the paleo-shorelines toward NNE, which indicates a decreasing trend in differential uplift in that direction ranging from almost 2 mm/a in the southwestern sector to about 0.2 mm/a in the northeastern sector. Detailed mapping and 3D reconstruction also emphasize the partitioning of the area into three distinct sectors characterized by different tilting rates. This behavior is likely caused by the combined role and activity of three major tectonic structures working at different scales and rates including (1) the reactivation of an out-of-sequence thrust, (2) sliding along the basal detachment of the external Apennines wedge and (3) a lithospheric-scale duplexing (crustal or deeper). As a major conclusion, within the external sector of the Southern Apennines chain and its foredeep, regional shortening and a contractional tectonic regime persisted throughout the whole Quaternary and it is probably still active.

  19. Acid deposition sensitivity map of the Southern Appalachian Assessment area; Virginia, North Carolina, South Carolina, Tennessee, Georgia, and Alabama

    USGS Publications Warehouse

    Pepper, John D.; Grosz, Andrew E.; Kress, Thomas H.; Collins, Thomas K.; Kappesser, Gary B.; Huber, Cindy M.; Webb, James R.

    1995-01-01

    Project Summary: The following digital product represents the Acid Deposition Sensitivity of the Southern Appalachian Assessment Area. Areas having various susceptibilities to acid deposition from air pollution are designated on a three tier ranking in the region of the Southern Appalachian Assessment (SAA). The assessment is being conducted by Federal agencies that are members of the Southern Appalachian Man and Biosphere (SAMAB) Cooperative. Sensitivities to acid deposition, ranked high, medium, and low are assigned on the basis of bedrock compositions and their associated soils, and their capacities to neutralize acid precipitation.

  20. The deglacial retreat of the Laurentide Ice Sheet's southern margin: Meltwater provenance insights from the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Williams, C.; Brown, E. A.; Hastings, D. W.; Lowell, T. V.; Shiller, A. M.; Shevenell, A.; Flower, B. P.

    2012-12-01

    Northern Gulf of Mexico (GOM) sediments document abrupt millennial-scale variability that may be linked to Laurentide Ice Sheet (LIS) melting and significant changes in Atlantic Meridional Overturning Circulation (AMOC) during the last deglaciation and Holocene (24-7 ka). To investigate the deglacial response of the southern margin of the LIS, the impact of meltwater on the GOM, and the influence of GOM meltwater events on the AMOC, we undertook a multi-proxy (foraminiferal δ18O, Mg/Ca, and Ba/Ca) geochemical study of a high-resolution (45 cm/kyr) sedimentary sequence from core MD02-2550, recovered from Orca Basin (2248 m water depth) in the GOM. Paired G. ruber (white and pink, separately) δ18O and Mg/Ca analyses allow us to use Mg/Ca paleothermometry to remove the temperature component of the δ18O signal, leaving behind a record of seawater δ18O (δ18Osw). After correcting the δ18Osw record for global ice volume, the resulting GOM δ18Oivc-sw record is primarily influenced by LIS meltwater. To assess how meltwater pulses influenced GOM salinity during deglaciation, we paired our δ18Oivc-sw record with a foraminiferal Ba/Ca record that reflects river discharge-induced salinity changes. Mississippi River Ba concentrations are elevated relative to GOM seawater (400 vs. 85 nM) and modern seawater Ba/Ca (Ba/Casw) exhibits a linear relationship with salinity (>20 psu). Because foraminiferal Ba/Ca exhibits a predictable relationship to Ba/Casw, it may be used to calculate changes in salinity arising from deglacial variations in Mississippi River discharge. A complicating factor for Ba/Ca-based salinity interpretations is that Ba concentrations vary spatially throughout the Mississippi River watershed. For example, modern Missouri and Upper Mississippi River Ba concentrations (633 and 436 nM, respectively) are higher than that of the Ohio River (253 nM). Thus, GOM Ba/Ca variability could reflect changes in total Mississippi River input and/or shifts in the dominant

  1. Oribatid mites (Acari, Oribatida) of plain area of the Southern European Russia.

    PubMed

    Lebedeva, Natalia V; Poltavskaya, Marina P

    2013-01-01

    The paper is devoted to the fauna of oribatid mites (Acari: Oribatida) mostly of a plain area of the Southern European Russia. The most updated taxonomic list of oribatid mite taxa compiled from the original authors' data collected after sam- pling soil, nests and plumage of birds, as well as published sources is presented. It includes 256 species of oribatid mites belonging to 72 families. Twenty species and one family of oribatid mites are recorded for the first time at the research territory. The abundance of mites in the soil is also provided for selected species. PMID:26240900

  2. A/M Area Groundwater Corrective Action Southern Sector Remediation Technology Alternatives Evaluation

    SciTech Connect

    Looney, B.B.; Phifer, M.A.

    1994-06-30

    Several technologies for clean up of solvents such as trichloroethylene, from groundwater were examined to determine the most reasonable strategy for the southern Sector in A/M Area of Savannah River Site. The most promising options identified were: pump and treat technology, airlift recirculation technology, and bioremediation technology. These options range from baseline/traditional methods to more innovative technologies. The traditional methods would be straightforward to implement, while the innovative methods have the potential to improve efficiency and reduce long term costs.

  3. Spatial Distribution of Taenia solium Porcine Cysticercosis within a Rural Area of Mexico

    PubMed Central

    Morales, Julio; Martínez, José Juan; Rosetti, Marcos; Fleury, Agnes; Maza, Victor; Hernandez, Marisela; Villalobos, Nelly; Fragoso, Gladis; de Aluja, Aline S.; Larralde, Carlos; Sciutto, Edda

    2008-01-01

    Cysticercosis is caused by Taenia solium, a parasitic disease that affects humans and rurally bred pigs in developing countries. The cysticercus may localize in the central nervous system of the human, causing neurocysticercosis, the most severe and frequent form of the disease. There appears to be an association between the prevalence of porcine cysticercosis and domestic pigs that wander freely and have access to human feces. In order to assess whether the risk of cysticercosis infection is clustered or widely dispersed in a limited rural area, a spatial analysis of rural porcine cysticercosis was applied to 13 villages of the Sierra de Huautla in Central Mexico. Clustering of cases in specific households would indicate tapeworm carriers in the vicinity, whereas their dispersal would suggest that the ambulatory habits of both humans and pigs contribute to the spread of cysticercosis. A total of 562 pigs were included in this study (August–December 2003). A global positioning system was employed in order to plot the geographic distribution of both cysticercotic pigs and risk factors for infection within the villages. Prevalence of pig tongue cysticercosis varied significantly in sampled villages (p = 0.003), ranging from 0% to 33.3% and averaging 13.3%. Pigs were clustered in households, but no differences in the clustering of cysticercotic and healthy pigs were found. In contrast, the presence of pigs roaming freely and drinking stagnant water correlated significantly with porcine cysticercosis (p = 0.07), as did the absence of latrines (p = 0.0008). High prevalence of porcine cysticercosis proves that transmission is still quite common in rural Mexico. The lack of significant differentiation in the geographical clustering of healthy and cysticercotic pigs weakens the argument that focal factors (e.g., household location of putative tapeworm carriers) play an important role in increasing the risk of cysticercosis transmission in pigs. Instead, it

  4. Application of integrated remote sensing and GIS technologies to geoenvironmental issues in far west Texas and southern New Mexico

    NASA Astrophysics Data System (ADS)

    Perez, Adriana Evangelina

    The primary goal of this dissertation was to utilize a geographic information system (GIS) to better understand geological, geophysical, forestry and environmental issues in the west Texas-New Mexico region. Studies such as these are especially important in the border region where economic limitations are usually a factor in studying and solving some of these problems. The availability of satellite imagery through the Pan-American Center for Earth and Environmental Studies (PACES), data from the Geospatial Center and the collaboration with the United States Department of Agriculture (USDA) and National Forest entities (Guadalupe and Lincoln Ranger Districts) enhance the value of our investigation. Research was conducted in two distinct areas: Cloudcroft-Ruidoso, New Mexico, and the Salt Flat basin of southwest Texas (Figure 1). The dissertation will be presented as a set of independent chapters. Chapter 1. A GIS and remote sensing investigation of the effects of interactions of terrain, soil, and other physiographic factors on the Pine Community of Lincoln National Park in the Sacramento Mountains of Southwest New Mexico. This study utilized GIS and remote sensing to better understand the dynamics of White Pine Blister Rust (WPBR) infestation in the white pine community of the Sacramento Mountains of southwest New Mexico. Both field spectral sampling of the needles and imagery analysis were incorporated to better understand the infestation, progression and vulnerability of the forest to this and other diseases. A major contribution of this study was to construct a GIS database, which was utilized to analyze USDA, elevation, satellite imagery, geological, and hydrological data to produce a hazard-rating map. The GIS environment also allowed for a 3-D perspective on the data, which was very useful in spatial visualization. Chapter 2. An integrated study of the basin structure of the Salt Flat basin. In this study we utilized, gravity and magnetic data, satellite

  5. The Ambrosia Lake project archaeological investigations of three small sites associated with the southern Chacoan outlier of Kin Nizhoni, McKinley County, New Mexico. [Uranium Mill Tailings Remedial Action (UMTRA) Project

    SciTech Connect

    Cullington, B.J.; Hammack, L.C.; Baugh, T.G. )

    1990-03-15

    During the fall of 1987, Complete Archaeological Service Associates conducted mitigative excavations at three sites (LA50363, LA50364, and LA50371) in McKinley County, New Mexico. These sites are adjacent to the Phillips/United Nuclear Inactive Uranium Mill and Tailings site at Ambrosia Lake, New Mexico. The primary deposition at each of these sites appears to be related to a Pueblo II or Bonito Phase occupation. Temporal placement is based primarily on the cross dating of ceramics and archaeomagnetic determinations when possible. No tree-ring or radiocarbon samples are available from these sites. These Ambrosia Lake sites indicate that this area was occupied primarily by Pueblo II people who may have had close social, economic, and ceremonial ties with the people living at the nuclear community of Lower Nizhoni about 3 km south-southeast. The later component at LA50364 indicates a Pueblo III occupation by people who may have had similar ties to the people of the Kin Nizhoni nuclear community. The Ambrosia Lake sites, then, provide important information on the structure of subnuclear communities within the southern Chaco periphery.

  6. A new genus and species of philometrid (Nematoda) from the subcutaneous tissue of the crevalle jack, Caranx hippos (Osteichthyes), from the southern Gulf of Mexico.

    PubMed

    Moravec, Frantisek; Montoya-Mendoza, Jesús; Salgado-Maldonado, Guillermo

    2008-12-01

    A new genus and species of nematode, Caranginema americanum n. gen., n. sp. (Philometridae), are described from gravid, subgravid, and nongravid female specimens collected from the subcutaneous tissue of the fish (crevalle jack) Caranx hippos (Carangidae, Perciformes) from the coral reef El Cabezo, southern Gulf of Mexico, Mexico. Caranginema, assigned to the Philometrinae, differs from other genera of this subfamily mainly in the presence of 2 conspicuous parallel cordons on either side, extending along nearly the entire body length and demarcating narrow smooth lateral fields and in having the remaining body surface with numerous ornamentations forming irregularly scattered, transversely elongated narrow cuticular molds. The new species is characterized mainly by the presence of 3 large, sclerotized esophageal teeth protruded out of the mouth, the number and arrangement of cephalic papillae (8 papillae in 4 pairs of external circle and 4 single papillae of internal circle), the length and structure of the esophagus, and by the body length of gravid and subgravid females (267 and 258 mm, respectively). Caranginema americanum is the seventh philometrid species reported from marine and brackish water fishes in Mexico. PMID:18576858

  7. The last two centuries of lead pollution in the southern Gulf of Mexico recorded in the annual bands of the scleractinian coral Orbicella faveolata.

    PubMed

    Horta-Puga, Guillermo; Carriquiry, José D

    2014-05-01

    Lead (Pb) pollution history (1855-2001 A.D.) of the southern Gulf of Mexico (SGM) was reconstructed from the geochemical record contained in the annual bands of the hermatypic coral Orbicella faveolata from the Veracruz Reef System, Mexico. Pb concentrations ranged from 5.5 μg/g in 1889-23.6 μg/g in 1992, with an average of 10.0 ± 4.1 μg/g. These high concentrations are evidence of a highly polluted environment. High statistical correlations were observed between the annual Pb coral time-series and both, the production of alkyl-lead gasoline in Mexico during the second half of the twentieth century (r = 0.86, p < 0.001), and the industrial production of lead in North America for the 1900-1940 years period (r = 0.73, p < 0.001). Hence, this research provides evidence that these two processes generated Pb-rich aerosols that were atmospherically transported, increasing the environmental levels of Pb in the SGM. PMID:24509657

  8. Spatial distribution and development of soils in tropical karst areas from the Peninsula of Yucatan, Mexico

    NASA Astrophysics Data System (ADS)

    Bautista, Francisco; Palacio-Aponte, Gerardo; Quintana, Patricia; Zinck, Joseph Alfred

    2011-12-01

    Better understanding of soil formation requires knowing the spatial distribution of the soils that allows constructing models of soil sequences in multiple directions along various types of gradients. This approach was applied to comprehend the soil formation from the soil distribution in the tropical karst areas of the Peninsula of Yucatan, Mexico. For soil mapping, a two-step methodology was followed. First, a geomorphic analysis was performed; subsequently, 382 soil profiles were reclassified and integrated into a geopedologic map. Additional soil survey was carried out in areas where soil information was lacking (123 soil profiles). Satellite images were used to identify flooded areas. After conducting numerous field verifications and analyses, landforms and soils were combined to make a soilscape map. Based on field observations and the soilscape map, soil development was analyzed on soil sequences. Four geomorphic environments were identified, karstic plains and hills with Leptosols, Cambisols, Luvisols, and Vertisols; coastal plains with Arenosols, Regosols, Solonchacks, and Histosols; fluvio-paludal plains with Gleysols, Histosols, Leptosols and Solonchacks; and tectono-karstic plains and hills with Leptosols, Cambisols, Luvisols, and Vertisols. Relevant soil forming factors in the Peninsula of Yucatan include time of emersion of the limestone platforms, climate, rock type, and macro- and micro-relief. Other factors such as groundwater level, fractures, also have an influence on soil formation. Karst development can be considered as a complex soil and relief forming factor. Terra Rossa soils as Leptosols, Cambisols, Luvisols, Nitisols and Vertisols in the Peninsula of Yucatan may be polygenic. In some cases, the theory of residual origin fits better the data than the theory of allochthonous origin; in other cases, it is the other way around.

  9. Sources, trends and regional impacts of fine particulate matter in southern Mississippi valley: significance of emissions from sources in the Gulf of Mexico coast

    NASA Astrophysics Data System (ADS)

    Chalbot, M.-C.; McElroy, B.; Kavouras, I. G.

    2013-04-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in the southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources, and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mineral/road dust, accounting for more than 90% of measured PM2.5 (particles with aerodynamic diameter less than 2.5 μm) mass. The declining trend of PM2.5 mass (0.4 μg m-3 per year) was related to lower levels of SO42- (0.2 μg m-3 per year) due to SO2 reductions from point and mobile sources. The slower decline for NO3- particles (0.1 μg m-3 per year) was attributed to the increasing NH3 emissions in the Midwest. The annual variation of biomass burning particles was associated with fires in the southeast and northwest US. Of the four regions within 500 km from the receptor site, the Gulf Coast and the southeast US accounted cumulatively for more than 65% of PM2.5 mass, nitrate, sulphate and biomass burning aerosol. Overall, more than 50% of PM2.5 and its components originated from sources outside the state. Sources within the Gulf Coast and western Gulf of Mexico include 65% of the busiest ports in the US, intense marine traffic within 400 km of the coast burning rich in S diesel, and a large number of offshore oil and natural gas platforms and many refineries. This approach allowed for the quantitative assessment of the impacts of transport from regions representing diverse mixtures of sources and weather conditions for different types of particles. The findings of this effort demonstrated the influences of emission controls on SO2 and NOx on PM2.5 mass, the potential effect of events (i.e. fires) sensitive to climate change phenomena on air pollution and the potential of offshore activities

  10. Sources, trends and regional impacts of fine particulate matter in southern Mississippi Valley: significance of emissions from sources in the Gulf of Mexico coast

    NASA Astrophysics Data System (ADS)

    Chalbot, M.-C.; McElroy, B.; Kavouras, I. G.

    2013-01-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mineral/road dust, accounting for more than 90% of measured PM2.5 mass. The declining trend of PM2.5 mass (0.4 μg m-3 yr-1) was related to lower levels of SO42- (0.2 μg m-3 yr-1) due to SO2 reductions from point and mobile sources. The slower decline for NO3- particles (0.1 μg m-3 yr-1) was attributed to the spatial variability of NH3 in Midwest. The annual variation of biomass burning particles was associated with wildland fires in southeast and northwest US that are sensitive to climate changes. The four regions within 500 km from the receptor site, the Gulf Coast and southeast US accounted cumulatively for more than 65% of PM2.5 mass, nitrate, sulphate and biomass burning aerosol. Overall, more than 50% of PM2.5 and its sources originated from sources outside the state. Sources within the Gulf Coast and western Gulf of Mexico include 65% of the busiest ports in the US, intense marine traffic within 400 km of the coast burning rich in S diesel, and a large number of offshore oil and natural gas platforms and many refineries along the coast. This approach allowed for quantitatively assessing the impacts of transport from regions representing diverse mixtures of sources and weather conditions for different types of particles. The findings of this effort demonstrated the influences of emission controls on SO2 and NOx on PM2.5 mass, the potential effect of events (i.e. fires) sensitive to climate change phenomena on air pollution and the potential of offshore activities and shipping emissions to

  11. A hierarchical classification of benthic biodiversity and assessment of protected areas in the Southern Ocean.

    PubMed

    Douglass, Lucinda L; Turner, Joel; Grantham, Hedley S; Kaiser, Stefanie; Constable, Andrew; Nicoll, Rob; Raymond, Ben; Post, Alexandra; Brandt, Angelika; Beaver, Daniel

    2014-01-01

    An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Important to this undertaking is knowledge of the distribution of benthic assemblages. Here, our aim is to identify the areas where benthic marine assemblages are likely to differ from each other in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 28 types of geomorphic features of the seabed, 562 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of existing MPAs. We found that 12 ecoregions are not represented in MPAs and that no ecoregion has their full range of environmental types represented in MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 8 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 107 spatially restricted environmental types, which should be considered for inclusion in future MPAs. Detailed supplementary data including a spatial dataset are provided. PMID:25032993

  12. A Hierarchical Classification of Benthic Biodiversity and Assessment of Protected Areas in the Southern Ocean

    PubMed Central

    Douglass, Lucinda L.; Turner, Joel; Grantham, Hedley S.; Kaiser, Stefanie; Constable, Andrew; Nicoll, Rob; Raymond, Ben; Post, Alexandra; Brandt, Angelika; Beaver, Daniel

    2014-01-01

    An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Important to this undertaking is knowledge of the distribution of benthic assemblages. Here, our aim is to identify the areas where benthic marine assemblages are likely to differ from each other in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 28 types of geomorphic features of the seabed, 562 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of existing MPAs. We found that 12 ecoregions are not represented in MPAs and that no ecoregion has their full range of environmental types represented in MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 8 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 107 spatially restricted environmental types, which should be considered for inclusion in future MPAs. Detailed supplementary data including a spatial dataset are provided. PMID:25032993

  13. Temporal and spatial constraints on the evolution of a Rio Grande rift sub-basin, Guadalupe Mountain area, northern New Mexico

    NASA Astrophysics Data System (ADS)

    Thompson, R. A.; Turner, K. J.; Cosca, M. A.; Drenth, B.; Hudson, M. R.; Lee, J.

    2013-12-01

    The Taos Plateau volcanic field (TPVF) in the southern San Luis Valley of northern New Mexico is the most voluminous of the predominantly basaltic Neogene (6-1 Ma) volcanic fields of the Rio Grande rift. Volcanic deposits of the TPVF are intercalated with alluvial deposits of the Santa Fe Group and compose the N-S-trending San Luis Basin, the largest basin of the northern rift (13,500 km2 in area). Pliocene volcanic rocks of the Guadalupe Mountain area of northern New Mexico are underlain by the southern end of one of the larger sub-basins of the San Luis Valley, the Sunshine sub-basin (~ 450 km2 in area) juxtaposed against the down-to-west frontal fault of the Precambrian-cored Sangre de Cristo Range. The sub-basin plunges northward and extends to near the Colorado-New Mexico border. The western margin (~15 km west of the Sangre de Cristo fault) is constrained by outcrops of Oligocene to Miocene volcanic rocks of the Latir volcanic field, interpreted here as a broad pre-Pliocene intra-rift platform underlying much of the northern TPVF. The southern sub-basin border is derived, in part, from modeling of gravity and aeromagnetic data and is interpreted as a subsurface extension of this intra-rift platform that extends southeastward to nearly the Sangre de Cristo range front. Broadly coincident with this subsurface basement high is the northwest-trending, curvilinear terminus of the down-to-northeast Red River fault zone. South of the gravity high, basin-fill alluvium and ~3.84 Ma Servilleta basalt lava flows thicken along a poorly exposed, down-to-south, basin-bounding fault of the northern Taos graben, the largest of the San Luis Valley sub-basins. The uppermost, western sub-basin fill is exposed along steep canyon walls near the confluence of the Rio Grande and the Red River. Unconformity-bound, lava flow packages are intercalated with paleo Red River fan alluvium and define six eruptive sequences in the Guadalupe Mountain area: (1) Guadalupe Mtn. lavas (dacite ~5

  14. Evaluation of the vehicle inspection/maintenance program in the Metropolitan Area of Mexico City.

    PubMed

    Schifter, I; Díaz, L; Vera, M; Guzmán, E; Durán, J; Ramos, F; López-Salinas, E

    2003-01-01

    The Inspection/Maintenance Program in the Metropolitan Area of Mexico City (MAMC) mandates a test every 6 months for all gasoline motor vehicles as one of the strategies to decrease emissions of vehicular pollutants. FTP-75 and ASM procedures were performed in our facilities to a fleet of 108 in-use motor vehicles before and after the approval of the I/M mandatory test When our laboratory-simulated ASM data were compared with those of the official certificate, a large difference was observed between them. On the other hand, audits at the test-only centers indicate poor maintenance of the analytical instruments and dynamometers. On the basis of our FTP results, an estimation of the emissions change for the MAMC fleet shows a net 4% decrease in CO emissions, while total hydrocarbons and NOx increased 9 and 8%, respectively. Our results indicate that the I/M system in the MAMC lacks the technical capability and investment to ensure that software and hardware are properly maintained, calibrated, and upgraded. Sometimes limited attention is paid to ensure adequate training of inspectors, auditors, and quality control staff. PMID:12542311

  15. [Bullying in the metropolitan area of Guadalajara, Mexico: prevalence and associated factors].

    PubMed

    Vega López, María Guadalupe; González Pérez, Guillermo Julián; Valle Barbosa, María Ana; Flores Villavicencio, María Elena; Vega López, Agustín

    2013-08-01

    This paper seeks to determine the prevalence of victims of school bullying among youth enrolled in public secondary schools in the metropolitan area of Guadalajara, Mexico and to identify the factors associated with being a victim of bullying in the period 2009-2011. An analytic cross-sectional study was carried out. A multistage probability sampling was designed for the public secondary schools, in which 1,706 students between 11 and 16 years old were studied. A questionnare with four sections was applied in order to identify victims of bullying. A logistic regression model was then used to measure the association between the factors analyzed and being a victim of bullying. The prevalence of school bullying was 17.6% (95% CI 15.8; 19.5). Personal factors, such as the feeling of not being accepted by peers or not spending much time with friends, were the factors with the strongest statistically significant association with being a victim of bullying. PMID:23989625

  16. Atmospheric Oxidation in the Mexico City Metropolitan Area (MCMA) during April 2003

    SciTech Connect

    Shirley, T.; Brune, W. H.; Ren, Xinrong; Mao, J.; Lesher, R.; Cardenas, B.; Volkamer, Rainer M.; Molina, Luisa; Molina, Mario J.; Lamb, Brian K.; Velasco, E.; Jobson, B Tom T.; Alexander, M. Lizabeth

    2006-07-07

    The Mexico City Metropolitan Area (MCMA) study in April 2003 provided a unique opportunity to examine atmospheric oxidation in a megacity that has more pollution than US and European cities. Most atmospheric constituents that are important for atmospheric oxidation, including the free radicals hydroxyl (OH) and hydroperoxyl (HO2), were measured. OH typically reached 7x106 cm-3, comparable to amounts observed in US cities, but HO2 reached 40 pptv in the early afternoon, substantially more than observed in most US cities. A steady-state chemistry model was able to simulate the measured OH and HO2 to within well within measurement and model errors bars except for nighttime, when measured OH was 5 times modeled and measured HO2 was 2.5 times modeled, and during morning rush hour, when measured HO2 was ~5 times modeled. We observed similar comparisons in US cities. The agreement between the measured and calculated OH reactivity to within uncertainties indicates that the volatile organic compounds important for atmospheric oxidation are known. The high calculated instantaneous ozone production rate from HO2 measurements is consistent with the high ozone levels typically observed in MCMA.

  17. Oil and gas developments in South America, Central America, Carribbean area, and Mexico in 1981

    SciTech Connect

    Deal, C.S.

    1982-11-01

    Petroleum developments in 1981 continued in the pattern of recent years of increasing exploration and exploitation in response to the second catastrophic surge in crude oil prices thrust on the world economy in 1979. Production of crude oil increased in Argentina, Brazil, Chile, Colombia, Guatemala, and Mexico, whereas Venezuela, Trinidad, Peru, and Bolivia experienced declines. Exploratory surveys, exploratory drilling, and development drilling all increased in most of the countries reporting. Significant successful exploratory drilling is reported for several countries. In Argentina, the producing zone of the Austral basin has been extended farther offshore, and is reportedly productive in what is apparently the upper Malvinas basin. In Brazil, extensions to several producing areas are reported in the Campos basin. Also, the Jurua gas province of western Amazonas reportedly had an encouraging extension. Colombia had several discoveries in the Magdalena basins, but the 2 Llanos discoveries are considered much more significant. For a variety of reasons, several countries have undertaken or are undertaking changes in laws and regulations to attract foreign companies into exploration risk ventures. In some countries, exploitation ventures are also offered.

  18. Geoid determination in the coastal areas of the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Song, HongZhi

    Coastal areas of the Gulf of Mexico are important for many reasons. This part of the United States provides vital coastal habitats for many marine species; the area has seen-ever increasing human settlement along the coast, ever increasing infrastructure for marine transportation of the nation's imports and exports through Gulf ports, and ever increasing recreational users of coastal resources. These important uses associated with the Gulf coast are subject to dynamic environmental and physical changes including: coastal erosion (Gulf-wide rates of 25 square miles per year), tropical storm surges, coastal subsidence, and global sea level rise. Coastal land subsidence is a major component of relative sea level rise along the coast of the Gulf of Mexico. These dynamic coastal changes should be evident in changes to the geoid along the coast. The geoid is the equipotential gravity surface of the earth, which the best fits the global mean sea level. The geoid is not only been seen as the most natural shape of the Earth, but also it serves as the reference surface for most of the height systems. By using satellites (GRACE mission) scientists have been able to measure the large scale geoid for the Earth. A small scale geoid model is required to monitor local events such as flooding, for example, flooding created by storm surges from hurricanes such as Katrina (2005), Rita (2005), and Ike (2008). The overall purpose of this study is to evaluate the accuracy of the local coastal geoid. The more precise geoid will enable to improve coastal flooding predictions, and will enable more cost effective and accurate measurement of coastal topography using global navigation satellite systems (GNSS). The main objective of this study is to devise mathematical models and computational methods to achieve the best possible precision for evaluation of the geoid in the coastal areas of the Gulf of Mexico. More specifically, the numerical objectives of this study are 1) to obtain a

  19. Processing of soot in an urban environment: case study from the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Johnson, K. S.; Zuberi, B.; Molina, L. T.; Molina, M. J.; Iedema, M. J.; Cowin, J. P.; Gaspar, D. J.; Wang, C.; Laskin, A.

    2005-08-01

    Chemical composition, size, and mixing state of atmospheric particles are critical in determining their effects on the environment. There is growing evidence that soot aerosols play a particularly important role in both climate and human health, but still relatively little is known of their physical and chemical nature. In addition, the atmospheric residence times and removal mechanisms for soot are neither well understood nor adequately represented in regional and global climate models. To investigate the effect of locality and residence time on properties of soot and mixing state in a polluted urban environment, particles of diameter 0.2-2.0 µm were collected in the Mexico City Metropolitan Area (MCMA) during the MCMA-2003 field campaign from various sites within the city. Individual particle analysis by different electron microscopy methods coupled with energy dispersed X-ray spectroscopy, and secondary ionization mass spectrometry show that freshly-emitted soot particles become rapidly processed in the MCMA. Whereas fresh particulate emissions from mixed-traffic are almost entirely carbonaceous, consisting of soot aggregates with liquid coatings suggestive of unburned lubricating oil and water, ambient soot particles which have been processed for less than a few hours are heavily internally mixed, primarily with ammonium sulfate. Single particle analysis suggests that this mixing occurs through several mechanisms that require further investigation. In light of previously published results, the internally-mixed nature of processed soot particles is expected to affect heterogeneous chemistry on the soot

  20. Processing of soot in an urban environment: case study from the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Johnson, K. S.; Zuberi, B.; Molina, L. T.; Molina, M. J.; Iedema, M. J.; Cowin, J. P.; Gaspar, D. J.; Wang, C.; Laskin, A.

    2005-11-01

    Chemical composition, size, and mixing state of atmospheric particles are critical in determining their effects on the environment. There is growing evidence that soot aerosols play a particularly important role in both climate and human health, but still relatively little is known of their physical and chemical nature. In addition, the atmospheric residence times and removal mechanisms for soot are neither well understood nor adequately represented in regional and global climate models. To investigate the effect of locality and residence time on properties of soot and mixing state in a polluted urban environment, particles of diameter 0.2-2.0 μm were collected in the Mexico City Metropolitan Area (MCMA) during the MCMA-2003 Field Campaign from various sites within the city. Individual particle analysis by different electron microscopy methods coupled with energy dispersed x-ray spectroscopy, and secondary ionization mass spectrometry show that freshly-emitted soot particles become rapidly processed in the MCMA. Whereas fresh particulate emissions from mixed-traffic are almost entirely carbonaceous, consisting of soot aggregates with liquid coatings suggestive of unburned lubricating oil and water, ambient soot particles which have been processed for less than a few hours are heavily internally mixed, primarily with ammonium sulfate. Single particle analysis suggests that this mixing occurs through several mechanisms that require further investigation. In light of previously published results, the internally-mixed nature of processed soot particles is expected to affect heterogeneous chemistry on the soot surface, including interaction with water during wet-removal.

  1. Comprehensive baseline environmental audit of former underground test areas in Colorado, Nevada, and New Mexico

    SciTech Connect

    Not Available

    1994-05-01

    This report documents the results of the Comprehensive Baseline Environmental Audit of Former Underground Test Areas (FUTAS) in the States of Colorado, Nevada, and New Mexico. DOE and contractor systems for management of environmental protection activities on the Nevada Test Site (NTS) were not within the scope of the audit. The audit was conducted May 16-May 26, 1994, by the Office of Environmental Audit (EH-24). DOE 5482.1 B, {open_quotes}Environment, Safety, and Health Appraisal Program{close_quotes}, establishes the mission of EH-24, which is to provide comprehensive, independent oversight of Department-wide environmental programs on behalf of the Secretary of Energy. The ultimate goal of EH-24 is to enhance environmental protection and minimize risk to public health and the environment. EH-24 accomplishes its mission using systematic and periodic evaluations of DOE`s environmental programs within line organizations and supplemental activities that strengthen self-assessment and oversight functions within program, field, and contractor organizations. These evaluations function as a vehicle through which the Secretary and program managers are apprised of the status and vulnerabilities of Departmental environmental activities and environmental management systems. Several types of evaluations are conducted, including: (1) comprehensive baseline environmental audits; (2) routine environmental audits; (3) environmental management assessments; and (4) special issue reviews.

  2. Investigation of OxProduction Rates in the Mexico City Metropolitan Area during MILAGRO

    NASA Astrophysics Data System (ADS)

    Dusanter, S.; Molina, L. T.; Stevens, P. S.

    2009-12-01

    Understanding the oxidative capacity of the atmosphere and the formation of secondary pollutants are important issues in atmospheric chemistry. For instance, the photochemical production of tropospheric ozone (O3) is of particular interest due to its detrimental effects on both human health and agricultural ecosystems. A detailed characterization of tropospheric O3 production rates will help in the development of effective control strategies. The 2006 Mexico City Metropolitan Area field campaign (MCMA-2006) was one of four components of MILAGRO (Megacity Initiative: Local And Global Research Observations) intended to collect information on the impact of megacity emissions on local, regional and global scales. In this presentation, rates of production of Ox (Ox = O3 + NO2) species during MCMA-2006 at the supersite T0 (Instituto Mexicano del Petroleo) will be presented using different approaches based on measured and modeled concentrations of ROx (OH + HO2 + RO2) radicals. In addition, we will examine both the reactivity of OH and the contribution of specific peroxy radicals to the oxidation rate of NO to estimate the contribution of groups of VOCs (alkanes, alkenes, aromatics, oxygenated and biogenic VOCs) to the total production rate of Ox species.

  3. Characteristics of PM2.5 in rural areas of southern Jiangsu Province, China.

    PubMed

    Zhou, Zhen-feng; Liu, Kang; Wang, Xiao-rong; Huang, Shi-hong

    2005-01-01

    To understand pollution level and possible sources of atmospheric fine particulates in rural areas of southern Jiangsu Province of China, samples of PM2.5 were collected and analyzed in Xueyan Town and Taihu Lake Station over three seasons from July 2002 to January 2003. The mass concentrations of PM2.5 and 14 principal component elements were obtained. The results showed that pollution of PM2.5 was serious and the concentration levels of S, Zn, Pb and As were similar to city. There are different seasonal distribution laws of pollutant elements in PM2.5 between two sampling sites, probably due to contribution of local sources, medium or long distance transportation of fine particulates and complicated meteorological conditions. The enrichment levels of S, Zn, Pb, As, K were high, reflecting the influence of anthropogenic activities. Particularly enrichment level of S was much higher in summer, which was probably related to meteorological condition. The result of principal components analysis showed major sources of PM2.5 included crustal resuspension, coal burning, metal processing industry or waste incineration, vehicular emission, which suggests anthropogenic activities is of important influence on PM2.5 in rural areas of southern Jiangsu Province. PMID:16465890

  4. Groundwater Modeling for the Southern Sector of A/M Area

    SciTech Connect

    HARRIS, MARYK.

    2001-11-01

    A plume of TCE contamination in the Southern Sector of A/M Area appears to have resulted from a former release at the A-014 outfall. A numerical groundwater flow and transport modeling analysis is described that addresses this plume, the existing remedial actions, and potential future remedial actions. The numerical flow and transport model is based on an understanding of the site that is formed in part by a recent analysis of hydrostratigraphic, head, and chemical data and by a recent groundwater flow modeling analysis that covers a wider area. The numerical model is calibrated to match observed water level measurements within acceptable criteria. The model is also qualitatively calibrated against the observed/inferred shape of the Southern Sector TCE plume. Though the calibration to the observed TCE plume is not perfect, the model is acceptable for comparing various remedial alternatives. Model simulations indicate that the existing remedial wells, which have been in operation near the A-014 outfall for over ten years, have been effective at removing much of the TCE plume mass. These wells should continue to be effective if operated. The model that is developed and used here can be used in the future to compare remedial alternatives and can be used as a tool to help optimize the operation of various remedial systems. The model may be improved in the future by recalibration following a revised interpretation of the source and/or the TCE plume.

  5. The tectonic puzzle of the Messina area (Southern Italy): Insights from new seismic reflection data

    PubMed Central

    Doglioni, Carlo; Ligi, Marco; Scrocca, Davide; Bigi, Sabina; Bortoluzzi, Giovanni; Carminati, Eugenio; Cuffaro, Marco; D'Oriano, Filippo; Forleo, Vittoria; Muccini, Filippo; Riguzzi, Federica

    2012-01-01

    The Messina Strait, that separates peninsular Italy from Sicily, is one of the most seismically active areas of the Mediterranean. The structure and seismotectonic setting of the region are poorly understood, although the area is highly populated and important infrastructures are planned there. New seismic reflection data have identified a number of faults, as well as a crustal scale NE-trending anticline few km north of the strait. These features are interpreted as due to active right-lateral transpression along the north-eastern Sicilian offshore, coexisting with extensional and right-lateral transtensional tectonics in the southern Messina Strait. This complex tectonic network appears to be controlled by independent and overlapping tectonic settings, due to the presence of a diffuse transfer zone between the SE-ward retreating Calabria subduction zone relative to slab advance in the western Sicilian side. PMID:23240075

  6. The tectonic puzzle of the Messina area (Southern Italy): insights from new seismic reflection data.

    PubMed

    Doglioni, Carlo; Ligi, Marco; Scrocca, Davide; Bigi, Sabina; Bortoluzzi, Giovanni; Carminati, Eugenio; Cuffaro, Marco; D'Oriano, Filippo; Forleo, Vittoria; Muccini, Filippo; Riguzzi, Federica

    2012-01-01

    The Messina Strait, that separates peninsular Italy from Sicily, is one of the most seismically active areas of the Mediterranean. The structure and seismotectonic setting of the region are poorly understood, although the area is highly populated and important infrastructures are planned there. New seismic reflection data have identified a number of faults, as well as a crustal scale NE-trending anticline few km north of the strait. These features are interpreted as due to active right-lateral transpression along the north-eastern Sicilian offshore, coexisting with extensional and right-lateral transtensional tectonics in the southern Messina Strait. This complex tectonic network appears to be controlled by independent and overlapping tectonic settings, due to the presence of a diffuse transfer zone between the SE-ward retreating Calabria subduction zone relative to slab advance in the western Sicilian side. PMID:23240075

  7. Background ozone in the southern Europe and Mediterranean area: influence of the transport processes.

    PubMed

    Cristofanelli, Paolo; Bonasoni, Paolo

    2009-05-01

    The troposphere is subject to continuous inputs, production and removal processes of ozone and its precursors from natural processes and human activities acting together within a very complex system. In order to assess the behaviour of background ozone in the Mediterranean area, a description of trends, seasonal and diurnal behaviours of free tropospheric ozone is provided. In the Mediterranean area and southern Europe the background tropospheric ozone concentration appears significantly affected by three main air mass transport processes: (i) transport of polluted air masses on regional and long-range scales, (ii) downward transport of stratospheric air masses, and (iii) transport of mineral dust from the Sahara desert. In this review of the literature of the last two decades, we present an overview of these phenomena, mainly monitored at high baseline mountain stations representative of background atmospheric conditions. PMID:18977575

  8. Ground-water hydrology and water quality of the southern high plains aquifer, Melrose Air Force Range, Cannon Air Force Base, Curry and Roosevelt Counties, New Mexico, 2002-03

    USGS Publications Warehouse

    Langman, Jeff B.; Gebhardt, Fredrick E.; Falk, Sarah E.

    2004-01-01

    In cooperation with the U.S. Air Force, the U.S. Geological Survey characterized the ground-water hydrology and water quality at Melrose Air Force Range in east-central New Mexico. The purpose of the study was to provide baseline data to Cannon Air Force Base resource managers to make informed decisions concerning actions that may affect the ground-water system. Five periods of water-level measurements and four periods of water-quality sample collection were completed at Melrose Air Force Range during 2002 and 2003. The water-level measurements and water-quality samples were collected from a 29-well monitoring network that included wells in the Impact Area and leased lands of Melrose Air Force Range managed by Cannon Air Force Base personnel. The purpose of this report is to provide a broad overview of ground-water flow and ground-water quality in the Southern High Plains aquifer in the Ogallala Formation at Melrose Air Force Range. Results of the ground-water characterization of the Southern High Plains aquifer indicated a local flow system in the unconfined aquifer flowing northeastward from a topographic high, the Mesa (located in the southwestern part of the Range), toward a regional flow system in the unconfined aquifer that flows southeastward through the Portales Valley. Ground water was less than 55 years old across the Range; ground water was younger (less than 25 years) near the Mesa and ephemeral channels and older (25 years to 55 years) in the Portales Valley. Results of water-quality analysis indicated three areas of different water types: near the Mesa and ephemeral channels, in the Impact Area of the Range, and in the Portales Valley. Within the Southern High Plains aquifer, a sodium/chloride-dominated ground water was found in the center of the Impact Area of the Range with water-quality characteristics similar to ground water from the underlying Chinle Formation. This sodium/chloride-dominated ground water of the unconfined aquifer in the Impact

  9. Vehicle Traffic as a Source of Particulate Polycyclic Aromatic Hydrocarbon Exposure in the Mexico City Metropolitan Area

    PubMed Central

    MARR, LINSEY C.; GROGAN, LISA A.; WÖHRNSCHIMMEL, HENRY; MOLINA, LUISAT.; MOLINA, MARIO J.; SMITH, THOMAS J.; GARSHICK, ERIC

    2005-01-01

    Surface properties of aerosols in the Mexico City metropolitan area have been measured in a variety of exposure scenarios related to vehicle emissions in 2002, using continuous, real-time instruments. The objective of these experiments is to describe ambient and occupational particulate polycyclic aromatic hydrocarbon (PAH) concentrations associated with vehicular traffic and facilities using diesel vehicles. Median total particulate PAH concentrations along Mexico City’s roadways range from 60 to 910 ng m−3, averaged over a minimum of 1 h. These levels are approximately 5 times higher than concentrations measured in the United States and among the highest measured ambient values reported in the literature. The ratio of particulate PAH concentration to aerosol active surface area is much higher along roadways and in other areas of fresh vehicle emissions, compared to ratios measured at sites influenced more by aged emissions or noncombustion sources. For particles freshly emitted by vehicles, PAH and elemental carbon (EC) concentrations are correlated because they both originate during the combustion process. Comparison of PAH versus EC and active surface area concentrations at different locations suggests that surface PAH concentrations may diminish with particle aging. These results indicate that exposure to vehicle-related PAH emissions on Mexico City’s roadways may present an important public health risk. PMID:15180054

  10. Active surveillance for acute flaccid paralysis in poliomyelitis high-risk areas in southern China.

    PubMed Central

    Chiba, Y.; Hikita, K.; Matuba, T.; Chosa, T.; Kyogoku, S.; Yu, J.; Wang, Z.

    2001-01-01

    OBJECTIVE: On 29 October 2000 poliomyelitis was officially declared to have been eradicated from the Western Pacific Region. This article describes the results of surveillance for cases of acute flaccid paralysis (AFP) in China during the final phase of the eradication effort. METHODS: We conducted hospital-based active surveillance in high-risk areas for poliomyelitis in 5 provinces of southern-China (Sichuan, Yunnan, Guizhou, Guangxi and Jiangxi) between 1995 and 1997 to determine the adequacy of reporting and laboratory diagnosis of cases of AFP. FINDINGS: A total of 1069 AFP cases occurring since 1993 were identified in 311 hospital visits. Less than 50% of AFP cases occurring in 1993 and 1994 had been reported by AFP surveillance, and laboratory diagnosis had been carried out on only a small proportion of these. However, improved cooperation between hospital sectors increased the rate of case reporting and laboratory diagnosis to 85% and 78%, respectively, in 1997. Despite this overall improvement, these two indicators were approximately 10-20% lower in Yunnan Province. Epidemiological analysis revealed that cases of clinical poliomyelitis accounted for as much as one-third of all AFP in 1993 and that some of these cases were clustered. Clusters were rarely observed after 1994. Active surveillance in the China-Myanmar border areas of Yunnan over 1995-96 detected 9 cross-border cases of clinical poliomyelitis, including 2 of wild poliomyelitis. Import of poliomyelitis was thus considered to have occurred frequently until 1996 in this border area of Yunnan. These data were important for the outbreak response immunization carried out in 1996 in the border prefectures of Yunnan. CONCLUSION: Our investigation confirmed a high level of AFP surveillance in poliomyelitis high-risk areas of the five provinces and provided valuable information on the interruption of wild poliovirus circulation in southern China that will be of use to countries in other regions that have

  11. Vertical distribution of soil organic carbon in limestone Mediterranean mountains areas, southern Spain

    NASA Astrophysics Data System (ADS)

    Gil, Juan; Jordan, Antonio; Martínez-Zavala, Lorena; Parras-Alcántara, Luis; Lozano-García, Beatriz

    2015-04-01

    Normally, soil organic carbon (SOC) investigations are related to fertility and/or soil quality so refer to surface horizon. In other cases, soil control sections or soil horizons are used to study soil carbon pool, especially in forest areas. In this line, in order to provide quantitative data of organic carbon in soils and sediments in relation to depth, the organic carbon vertical distribution was studied in selected areas of southern Spain. Significant variations in depth of organic carbon may be related with different vegetation and/or land use changes, so it can be used to select sampling points for studying these changes through pollen analysis. For this study, ten sinkholes in hard limestone Mediterranean mountains areas of southern Spain have been selected following scientific interest criteria and/or minimal human influence. Soil and sediment samples extraction was carried out using tensile steel drills up to four meters in deep driven by an electric striking hammer. Once extracted the soil columns, soil control sections are taken every 5 cm, obtaining 470 samples in the ten sinkholes selected and making four replications for each soil control section. The soil and sediments exploration in different sinkholes highlights the karst heterogeneity formations, especially in terms of its depth. Thus, it was possible to take samples of varying depth, ranging between 1 and 5 m, being the limiting factor the hard pan forming which can be soil nature (petrocalcic horizon) or lithological nature (hard limestone). SOC in every sampling point varied between 2.5 and 16.7 g kg-1. In general, SOC concentrations decreases progressively in depth, although in some sampling point 10 g kg-1 were obtained at 200 cm in depths. On the other hand, it had been observed significant increases at 100 cm in deep, sometimes repeating at high deep, which could be related to ancient sedimentary past or with edaphogenic processes past. Definitely more comprehensive studies could shed new

  12. The epidemiology of Entamoeba histolytica in a rural and an urban area of Mexico. A pilot survey II.

    PubMed

    Sargeaunt, P G; Williams, J E; Bhojnani, R; Campos, J E; Gomez, A

    1982-01-01

    Stocks of intestinal amoebae grown in monoxenic culture, were compared against each other and against those previously reported from Mexico City. These were isolated from subjects in San Cristobal de las Casas, Chiapas (rural area) and hospital patients in Merida, Yucatan (urban area). Electrophoretic patterns of the four enzymes: glucose phosphate isomerase (GPI), phosphoglucomutase (PGM), L-malate: NADP+ oxido-reductase (oxalacetate-decarboxylating) (ME) and hexokinase (HK) demonstrated the presence of five groups (zymodemes) of Entamoeba histolytica already described from Mexico City, together with two new zymodemes, one of which gave a recognizable pathogenic pattern, whilst the other gave a contradictory pattern. Zymodemes of Entamoeba coli, Entamoeba hartmanni, Iodamoeba buetschlii and Dientamoeba fragilis, previously described were also isolated. One new zymodeme of D. fragilis was demonstrated. PMID:6285556

  13. 78 FR 36571 - Extension of Post-Sale Evaluation Period for Central Gulf of Mexico Planning Area Lease Sale 227

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ...This notice extends through July 18, 2013, the post-sale evaluation period for Central Gulf of Mexico Planning Area Lease Sale 227. BOEM will complete the evaluation process for all bids received in this sale by July 18, 2013. This action is necessary due to resource limitations resulting from sequestration. BOEM is unable to pay overtime to expedite the bid review process, including the......

  14. 77 FR 29683 - Outer Continental Shelf (OCS) Consolidated Central Gulf of Mexico Planning Area Sale; 216/222

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ...On Wednesday, June 20, 2012, BOEM will open and publicly announce bids received for the blocks offered in Central Gulf of Mexico Planning Area (CPA) Sale 216/222, in accordance with provisions of the OCS Lands Act (OCSLA) (43 U.S.C. 1331-1356, as amended) and the regulations issued thereunder (30 CFR part 556). The CPA Sale 216/222 Package contains information essential to potential bidders,......

  15. Triggered Fault Slip in Southern California Associated with the 2010 Sierra El Mayor-Cucapah, Baja California, Mexico, Earthquake

    NASA Astrophysics Data System (ADS)

    Rymer, M. J.; Treiman, J. A.; Kendrick, K. J.; Lienkaemper, J. J.; Wei, M.; Weldon, R. J.; Bilham, R. G.; Fielding, E. J.

    2010-12-01

    Surface fracturing (triggered slip) occurred in the central Salton Trough and to the southwest, in the Yuha Desert area—all in association with the 4 April 2010 (M7.2) El Mayor-Cucapah earthquake and its aftershocks. Triggered slip in the central Salton Trough occurred on the ‘frequent movers’: the southern San Andreas, Coyote Creek, Superstition Hills, and Imperial Faults, all of which have slipped in previous moderate to large, local and regional earthquakes in the past five decades. Other faults in the central Salton Trough that also slipped in 2010 include the Wienert Fault (southeastern section of the Superstition Hills Fault), the Kalin Fault (in the Brawley Seismic Zone), and the Brawley Fault Zone; triggered slip had not been reported on these faults in the past. Geologic measures of slip on faults in the central Salton Trough ranged from 1 to 18 mm, and everywhere was located where previous primary (tectonic) or triggered slip has occurred. Triggered slip in the Yuha Desert area occurred along at least two dozen faults, only some of which were known before the 4 April 2010 El Mayor-Cucapah earthquake. From east to northwest, slip occurred in seven general areas; 1) in the Northern Centinela Fault Zone (newly named), 2) along unnamed faults south of Pinto Wash, 3) along the Yuha Fault (newly named), 4) along both east and west branches of the Laguna Salada Fault, 5) along the Yuha Well Fault Zone (newly revised name), 6) along the Ocotillo Fault (newly named), and 7) along the southeastern-most section of the Elsinore Fault. Faults that slipped in the Yuha Desert area include northwest-trending right-lateral faults, northeast-trending left-lateral faults, and north-south faults, some of which had dominantly vertical slip. Triggered slip along the Ocotillo and Elsinore Faults occurred only in association with the 14 June 2010 (M5.7) aftershock, which also initiated slip along other faults near the town of Ocotillo. Triggered slip on faults in the Yuha

  16. Fluvial systems response to rift margin tectonics: Makhtesh Ramon area, southern Israel

    NASA Astrophysics Data System (ADS)

    Ben-David, Ram; Eyal, Yehuda; Zilberman, Ezra; Bowman, Dan

    2002-06-01

    The geomorphic evolution of Makhtesh Ramon, a feather-shaped erosional valley, and the Nahal Neqarot drainage system to the south occurred largely in response to tectonic activity along the Dead Sea Rift and its western shoulder. Remnants of Miocene clastic sediments (Hazeva Formation) deposited on an erosional peneplain that formed over this area during the Oligocene epoch provide a datum plane for reconstructing subsequent fluvial evolution. These clastic remnants are presently located on the shoulders of Makhtesh Ramon at various elevations. The peneplain truncating the Makhtesh Ramon block has been tilted 0.7% northeastward since the Pliocene epoch (post-Hazeva Formation), whereas that of the Neqarot syncline, south of the Ramon, has been tilted 1.2%. The elliptical exposure of friable Lower Cretaceous sandstone, exposed in the core of the truncated Ramon structure, governed the development of a new ENE directed (riftward) drainage system through capture of streams that previously drained toward the Mediterranean Sea to the northwest. Incised fluvial gaps in the southern rim of Makhtesh Ramon and alluvial fan relicts within Makhtesh Ramon attest to original drainage into the Makhtesh from the south. Remnants of the Plio-Pleistocene Arava Conglomerate on the eastern end of the Neqarot syncline contain clasts from rocks exposed within Makhtesh Ramon, also indicating that streams flowed into the Makhtesh from the southern Neqarot block through the western gaps, then turning eastward and exiting the Makhtesh via the next (Sha'ar-Ramon) gap to the east. Further down-faulting of the Neqarot block during Mid-Late Pleistocene time led to westward retreat of the Neqarot valley and capture of the last stream flowing northward into the Ramon, leaving the modern Makhtesh Ramon isolated from the southern drainage system.

  17. Why is the central area of the Alburni Mts in southern Italy so full of caves?

    NASA Astrophysics Data System (ADS)

    Cafaro, Simona; Gueguen, Erwan; Parise, Mario; Schiattarella, Marcello

    2016-04-01

    The Alburni Mts represent one of the most important karst area of southern Italy, with about 250 registered caves. Located in the southern Apennines, they constitute an impressive carbonate massif within the Mesozoic-Cenozoic Campania-Lucania platform. The study area is located inside the National Park of Cilento, Vallo di Diano and Alburni, and is bounded by two major rivers: the Calore and Tanagro rivers. This area has been repeatedly affected during Pleistocene by the activity of a regional, partly blind, NW-SE-striking fault system responsible for several huge earthquakes. The massif is limited to the north by an important normal fault zone (Alburni Line), whereas towards the E-SE it is bounded by a complex fault system linking the Alburni Mts to the Maddalena Mts across the Auletta basin and the Vallo di Diano valley. The entire massif is structured by NW-SE trending transtensional faults delimiting half-graben basins, and offset also by NE-SW trending faults. In particular, structural and geomorphological data have shown that the central area of the calcareous ridge is characterized by a relative structural low rhombic-shaped in planimetric view. Approximately 180 karst caves of the known 250, including some of the most significant from a speleological viewpoint, are located in this area. Is this simply due to repeated exploration activity in the last 25 years in this specific sector or might it be related to geological matter? New morphometric and structural data suggest that a relevant transversal structure, consisting of a complex NE-SW fault system, responsible for the genesis of the downthrown area in the central sector of the flat-topped ridge, was able to create the tectonic framework for the development of a great number of karst caves which present peculiar features and hydrological behaviour due to such structural controls. In this contribution we present and discuss these data, aimed at contributing to increase the knowledge on an area of sure

  18. Effect of the El Nino/southern oscillation on Gulf of Mexico, winter, frontal-wave cyclones: 1960-1989. (Volumes I and II)

    SciTech Connect

    Manty, R.E.

    1993-01-01

    Seasonal counts of frontal-wave cyclones forming over the Gulf of Mexico and its coastal plain show more storms in the five El Nino winters and fewer storms in the eight La Nina winters, from 1960 to 1989, significant at the .01 level by a rank sum test. This is corroborated by two results. First, during the same period, the frequency of frontal-overrunning weather conditions in the region, indicative of storms, was higher in El Nino winters and lower in La Nina winters. Second, 100 years of precipitation and temperature records show wetter, cooler El Nino winters and drier, warmer La Nina winters at gulf-region land stations and climatic divisions. A threefold explanation, based on National Meteorological Center, upper-air data, is offered for the greater frequency of gulf-region cyclogenesis during El Nino winters between 1960 and 1989. (1) The winter, mean, 250-mb jet over the southern US is intensified by 5 to 10 ms[sup [minus]1] and displaced southward between 110[degrees] and 75[degrees]W by an average of 200 to 285 km during the five El Nino winters. This implies stronger and more frequent episodes of jet-associated, upper-level troughing and divergence over the region, reinforcing surface, frontal-wave cyclones. (2) In the five El Nino winters between 1963 and 1989, seasonal average heights and temperatures of the 850-, 700-, 500-, and 200-mb surfaces are lower over the region than they are in non-El Nino winters. This implies more-common presence of cold, low-pressure troughs at upper levels, reinforcing surface cyclones. (3) A 10[degrees] eastward shift, at sea level, of the western edge of the Bermuda high during the eight El Nino winters, changes normally due-easterly trades in the northwestern Caribbean Sea to slightly south of east, allowing greater advection of moisture and heat into the gulf from the tropics, preconditioning the area for development of surface cyclones. Only winter season shows all three conditions and an increase in cyclogenesis.

  19. Geochemistry of low-grade clastic rocks in the Acatlán Complex of southern Mexico: Evidence for local provenance in felsic-intermediate igneous rocks

    NASA Astrophysics Data System (ADS)

    Dostal, Jaroslav; Keppie, J. D.

    2009-12-01

    Geochemical data of sedimentary basins have been used to determine their plate tectonic setting. Here we test geochemical data for paired psammite-pelite samples from two greywacke packages that underlie 60% of the Paleozoic Acatlán Complex of southern Mexico: one an Ordovician rift-passive margin suite and the other a Carboniferous active margin suite. Both units consist of low-grade, polydeformed psammites and pelites associated with rare tholeiitic flows and dikes. Analyses of paired psammite-pelite samples from a number of different units in the eastern part of the Acatlán Complex indicate that they all have a similar geochemistry with their major components dependent on the proportion of sand and clay. The chemical index of alteration yielded values between 55 and 70 recording a moderate degree of weathering of plagioclase to illite/kaolinite in the source area. The REE patterns suggest provenance in felsic-intermediate igneous rocks, and the wide range of TiO 2-Zr ratios indicates that this was followed by extensive sorting. The mantle-normalized trace element patterns of the psammites generally display positive Zr and Hf anomalies reflecting elevated concentration of zircon in these rocks. Detrital zircon ages from some of these units show that the major source for these clastic rocks probably lay in the adjacent Mesoproterozoic Oaxacan Complex and in the Neoproterozoic basement underlying the Acatlán Complex and/or the Yucatan Peninsula. Geological parameters point to a rift-passive margin setting for the Ordovician rocks and an active, subduction-related margin for the Carboniferous units. However, the commonly used tectonic discrimination, bi- to tri-variant diagrams cannot readily distinguish between the two suites on geochemical grounds. Their geochemistry probably reflects the general felsic-intermediate compositions of the rocks in the Precambrian source regions, rather than the contemporaneous tectonic setting. Future work involving a more

  20. Faulting, volcanism, and basin development along the western margin of the southern San Luis Basin segment of the Rio Grande rift, New Mexico and Colorado

    NASA Astrophysics Data System (ADS)

    Turner, K. J.; Thompson, R. A.; Cosca, M. A.; Drenth, B.; Lee, J.; Budahn, J. R.

    2011-12-01

    The San Luis Basin segment of the northern Rio Grande rift, straddling the Colorado-New Mexico border, is an asymmetrical graben where the major basin-bounding fault is on the east side. In contrast, the west side is a basin-directed dip slope surface cut by north to northwest trending faults with predominantly down-to-southwest displacement. Around 26 Ma, initial rift-related faulting formed broad, shallow basins coincident with basaltic volcanism of the Hinsdale Formation. Later episodes of rifting produced deep and narrow sub-basins generally along the eastern boundary. Basin-fill deposits along the western margin are generally thin. However, in the northern Tusas Mountains, gravity data identifies a small, yet deep, sub-basin that may contain 750 m of basin-filling Los Pinos Formation based on thickness projections derived from mapping. The Los Pinos Formation is overlain by early rift-related Hinsdale Formation basalt flows indicating this sub-basin formed as part of early rifting; the sub-basin may be a southern extension of the Monte Vista graben to the north. The stratigraphic section along the western boundary includes Precambrian basement up to volcanic rocks of the Taos Plateau volcanic field (~5-2Ma). Dips on the early-rift Miocene to Oligocene Hinsdale Formation lavas (3-5 degrees) reflect the cumulative eastward tilting corresponding to continued basin subsidence. Shallower dips (1-2 degrees) on early Pliocene volcanic rocks suggest continued subsidence up to about 3 Ma, or younger. Down-to-southwest faults accommodating eastward tilting are mostly in areas west of Pliocene volcanic rocks; individual faults offset Hinsdale Formation and older rocks by up to 200 m. The few observed faults in the Pliocene volcanic rocks have minor offset. Numerous volcanic vents are in close proximity to the faults along the western boundary. Volcanoes are commonly low to medium relief shield volcanoes with basaltic andesite composition capped by late stage cinder cones

  1. Development and Application of Environmental Quality of Life Scale among People Residing near Three Types of Industrial Areas, Southern Thailand

    ERIC Educational Resources Information Center

    Sopsuk, Jirawan; Chongsuvivatwong, Virasakdi; Sornsrivichai, Vorasith; Hasuwanakit, Supat

    2013-01-01

    To compare QOL among rural people living in three different industrial areas and one non-industrial area in southern Thailand. A questionnaire based on the WHOQOL-BREF with environmental assessment was initially developed. After consultation with experts and pilot study, it was tested to check internal reliability and further modified as…

  2. The Labor Force Characteristics of Women in Low-Income Rural Areas of the South. Southern Cooperative Series Bulletin 116.

    ERIC Educational Resources Information Center

    Terry, Geraldine B.; Bertrand, Alvin L.

    Selected data from the Southern Regional S-44 Project entitled "Factors in the Adjustment of Families and Individuals in Low-Income Rural Areas" were analyzed to determine the work patterns of women in low-income rural areas. Objectives of the study were to describe the labor force experience of women, to report the attitudes of employed women…

  3. Geological sources of fluoride and acceptable intake of fluoride in an endemic fluorosis area, southern Iran.

    PubMed

    Battaleb-Looie, Sedigheh; Moore, Farid; Jacks, Gunnar; Ketabdari, Mohammad Reza

    2012-10-01

    The present study is the first attempt to put forward possible source(s) of fluoride in the Dashtestan area, Bushehr Province, southern Iran. In response to reports on the high incidence of dental fluorosis, 35 surface and groundwater samples were collected and analysed for fluoride. The results indicate that dissolved fluoride in the study area is above the maximum permissible limit recommended by the World Health Organization (WHO). An additional 35 soil and rock samples were also collected and analysed for fluoride, and rock samples were subjected to petrographic investigations and X-ray diffraction. The results of these analyses show that the most likely source for fluoride in the groundwater is from clay minerals (chlorite) and micas (muscovite, sericite, and biotite) in the soils and rocks in the area. We also note that due to the high average temperatures all year round and excessive water consumption in the area, the optimum fluoride dose level should be lower than that recommended by the WHO. PMID:22426705

  4. Remote sensing study of emissions from motor vehicles in the Metropolitan Area of Mexico City.

    PubMed

    Schifter, I; Díaz, L; Durán, J; Guzmán, E; Chávez, O; López-Salinas, E

    2003-01-15

    Remote sensing was employed for the first time to measure nitric oxide (NO) levels of on-road light-duty motor vehicles of the Metropolitan Area of Mexico City (MAMC). The sensor placed at 12 different sites also measured the concentration of CO2, CO, and total hydrocarbons (THC) in the exhaust emissions. A database was compiled containing 122 800 readings, of which 84 650 (69%) records were valid emissions measurements. CO, HC, and NO valid readings were 68.9, 63.4, and 62.9%, respectively, of the total attempted measurements. Furthermore, 42 822 vehicles were number-plate-matched to model year with the information provided by the Inspection/Maintenance Program. The mean emissions of total valid readings for CO, HC, and NO were determined to be 1.31 vol %, 440 ppm (propane), and 914 ppm, respectively. In 1991 and 1994, remote sensing measurements of CO and HC tailpipe emissions were performed in the MAMC in five different locations (30 000 valid readings). Large drops in both pollutants were observed for the intervening years, but sufficient vehicle information was not available at that time to fully explain the observed trends. Compared with those reports, our results point out to a steady decrease in CO and HC exhaust emissions with vehicle model year. The fleet emissions measured exhibit a gamma-distribution, with 10% of the most polluting fleet studied being responsible for 45%, 25%, and 29% of the CO, HC, and NO emissions, respectively. NO emissions in taxis are the highest among the vintage of vehicles, a matter of concern since according to the distance traveled per year, they represent 22% of the total activity in the MAMC. PMID:12564914

  5. Levels of dichlorodiphenyltrichloroethane and deltamethrin in humans and environmental samples in malarious areas of Mexico.

    PubMed

    Yáñez, Leticia; Ortiz-Pérez, Deogracias; Batres, Lilia E; Borja-Aburto, Víctor H; Díaz-Barriga, Fernando

    2002-03-01

    Mexico used dichlorodiphenyltrichloroethane (DDT) to control malaria until 1999, when it was replaced with deltamethrin for mosquito control. Thus, we performed environmental and exposure assessments to DDT and deltamethrin in the states of Chiapas and Oaxaca. In Chiapas, samples were obtained at the time when DDT was being used in the malaria control program, while in Oaxaca, samples were collected 2 years after the final spraying of DDT and 2 days after deltamethrin application. Mean concentrations of DDT and Dichlorodiphenyldichloroethylene (DDE), as measured in whole blood, were 67.8 and 86.7 microg/L for children living in Chiapas and 27.1 and 60.8 microg/L for adults, respectively. As expected, DDT levels were lower 2 years after the final application in Oaxaca (20.4 and 13.2 microg/L for children and adults, respectively). Sprayers in Chiapas had the highest levels of exposure, with 165.5 and 188.4 microg/L of DDT and DDE, respectively. Women living in Chiapas and Oaxaca also had significantly higher blood levels of DDT and DDE than those women living in areas where less DDT had been used. Deltamethrin exposure was assessed only in children living in Oaxaca; 50% of the exposed group had urinary levels of 3-phenoxybenzoic acid above the limit of detection (LOD) and 6% had levels above 25 microg/L (five times the LOD), with a negative trend with age (r=-0.33). In Chiapas we found higher DDT and DDE levels in soil than in Oaxaca. In the latter location, large amounts of DDT and DDE were found in sediment samples and deltamethrin was detected in indoor soil samples. Considering the environmental data, the blood level results can be explained by soil/dust ingestion, human milk ingestion, and consumption of fish and other contaminated foods. PMID:12051795

  6. Aerosol Simulation in the Mexico City Metropolitan Area during MCMA2003 using CMAQ/Models3

    NASA Astrophysics Data System (ADS)

    Bei, N.; Zavala, M.; Lei, W.; de Foy, B.; Molina, L.

    2007-12-01

    CMAQ/Models3 has been employed to simulate the aerosol distribution and variation during the period from 13 to 16 April 2003 over the Mexico City Metropolitan Area as part of MCMA-2003 campaign. The meteorological fields are simulated using MM5, with three one-way nested grids with horizontal resolutions of 36, 12 and 3 km and 23 sigma levels in the vertical. MM5 3DVAR system has also been incorporated into the meteorological simulations. Chemical initial and boundary conditions are interpolated from the MOZART output. The SAPRC emission inventory is developed based on the official emission inventory for MCMA in 2004. The simulated mass concentrations of different aerosol compositions, such as elemental carbon (EC), primary organic aerosol (POA), secondary organic aerosol (SOA), nitrate, ammonium, and sulfate have been compared to the measurements taken at the National Center for Environmental Research and Training (Centro Nacional de Investigacion y Capacitacion Ambiental, CENICA) super-site. Hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA) are used as observations of POA and SOA, respectively in this study. The preliminary model results show that the temporal evolutions of EC and POA are reasonable compared with measurements. The peak time of EC and POA are basically reproduced, thus validating the emission inventory and its processing through CMAQ/Models3. But the magnitude of EC and POA are underestimated over the entire episode. The modeled nitrate and ammonium concentrations are overestimated on most of the days. There is 1-2 hour difference between the simulated peak time of nitrate and ammonium aerosols compared to observations at CENICA. The simulated mass concentrations of SOA and sulfate are significantly underestimated. The reasons of the discrepancy between simulations and measurements are due to the uncertainties existing in the emission inventory, meteorological fields, and as well as aerosol formation mechanism in the case

  7. Processing of Soot in an Urban Environment: Case Study from the Mexico City Metropolitan Area

    SciTech Connect

    Johnson, Kirsten S.; Zuberi, Bilal M.; Molina, Luisa; Molina, Mario J.; Iedema, Martin J.; Cowin, James P.; Gaspar, Daniel J.; Wang, Chong M.; Laskin, Alexander

    2005-11-14

    Chemical composition, size, and mixing state of atmospheric particles are critical in determining their e ffects on the environment. There is growing evidence that soot aerosols play a particularly important role in both climate and human health, but still relatively little is known of their physical and chemical nature. In addition, the atmo- 5 spheric residence times and removal mechanisms for soot are neither well understood nor adequately represented in regional and global climate models. To investigate the effect of locality and residence time on properties of soot and mixing state in a polluted urban environment, particles of diameter 0.2–2.0 µm were collected in the Mexico City Metropolitan Area (MCMA) during the MCMA-2003 field campaign from various sites 10 within the city. Individual particle analysis by di fferent electron microscopy methods coupled with energy dispersed X-ray spectroscopy, and secondary ionization mass spectrometry show that freshly-emitted soot particles become rapidly processed in the MCMA. Whereas fresh particulate emissions from mixed-tra ffic are almost entirely carbonaceous, consisting of soot aggregates with liquid coatings suggestive of unburned 15 lubricating oil and water, ambient soot particles which have been processed for less than a few hours are heavily internally mixed, primarily with ammonium sulfate. Single particle analysis suggests that this mixing occurs through several mechanisms that require further investigation. In light of previously published results, the internally-mixed nature of processed soot particles is expected to a ffect heterogeneous chemistry on 20 the soot surface, including interaction with water during wet-removal.

  8. Timber resource statistics for the San Joaquin and southern resource areas of California. Forest Service resource bulletin

    SciTech Connect

    Waddell, K.L.; Bassett, P.M.

    1997-05-01

    This report is a summary of timber resource statistics for the San Joaquin and Southern Resource Areas of California. Data were collected as part of a statewide multiresource inventory. The inventory sampled private and public lands except reserved areas and National Forests. The National Forest System provided data from regional inventories of some areas. Area information for parks and other reserves was obtained directly from the organizations managing these areas. Statistical tables summarize all ownerships and provide estimates of land area, timber volume, growth, mortality, and harvest. Estimates of periodic change of timberland area and timber volume are presented for all ownerships outside National Forests.

  9. An evaluation of Landsat 3 RBV imagery for an area of complex terrain in Southern Italy

    NASA Technical Reports Server (NTRS)

    Townshend, J. R. G.; Williams, D. F.; Justice, C. D.

    1979-01-01

    Return Beam Videcon imagery from Landsat 3 was obtained in August, 1978 for part of Southern Italy in the regions of Basilicata and Apulia. The resolution of this imagery for medium contrast objects is approximately 40 meters and is shown to provide significant information concerning land cover and fluvial morphometry. Because of the wide spectral band width which is sensed (0.505-0.750 microns) by the RBV cameras, discrimination is only possible for spectrally distinct cover types, especially oak woodland. Fluvial morphometry can be readily described using the imagery. Because of the intense dissection of the area, the lowest order streams cannot be consistently mapped, but the rank order of the measured values of properties such as drainage density and link frequency for different lithologies corresponds closely to the actual ranking.

  10. A preliminary evaluation of ERTS-1 images on the volcanic areas of Southern Italy

    NASA Technical Reports Server (NTRS)

    Cassinis, R.; Lechi, G. M.

    1973-01-01

    The test site selected for the investigation covers nearly all the regions of active and quiescent volcanism in southern Italy, i.e. the eastern part of the island of Sicily, the Aeolian Islands and the area of Naples. The three active European volcanoes (Etna, Stromboli and Vesuvius) are included. The investigation is in the frame of a program for the surveillance of active volcanoes by geophysical (including remote sensing thermal methods) and geochemical methods. By the multispectral analysis of ERTS-1 data it is intended to study the spectral behavior of the volcanic materials as well as the major geological lineaments with special reference to those associated with the volcanic region. Secondary objectives are also the determination of the hydrographic network seasonal behavior and the relationship between the vegetation cover and the different type of soils and rocks.

  11. Forest classes and tree cover gradient: tick habitat in encroached areas of southern Norway.

    PubMed

    Vanwambeke, S O; Van Doninck, J; Artois, J; Davidson, R K; Meyfroidt, P; Jore, S

    2016-03-01

    Forest, in particular deciduous forest, is a key element in determining areas with a high probability of tick presence. The way forest is generally monitored may be ill suited to some landscapes where Ixodes ricinus is found, as forest is usually characterised using crisp land cover classes. However, tree vegetation can be found outside of forests and continuous gradations of tree density can be found in a variety of landscapes. In this paper we investigate the probability of tick presence in southern Norway using landscape description based both on land cover classes and continuous data describing the tree cover fraction. Both perspectives on the landscape are significant in the logistic model, indicating that the usual approach based solely on land cover classes may not be comprehensive enough in capturing tick habitat, and characterising the landscape with variables focused on single specific elements may be insufficient. PMID:26692382

  12. Analysis of pseudocolor transformations of ERTS-1 images of Southern California area. [geological faults and lineaments

    NASA Technical Reports Server (NTRS)

    Merifield, P. M. (Principal Investigator); Lamar, D. L.; Stratton, R. H.; Lamar, J. V.; Gazley, C., Jr.

    1974-01-01

    The author has identified the following significant results. Representative faults and lineaments, natural features on the Mojave Desert, and cultural features of the southern California area were studied on ERTS-1 images. The relative appearances of the features were compared on a band 4 and 5 subtraction image, its pseudocolor transformation, and pseudocolor images of bands 4, 5, and 7. Selected features were also evaluated in a test given students at the University of California, Los Angeles. Observations and the test revealed no significant improvement in the ability to detect and locate faults and lineaments on the pseudocolor transformations. With the exception of dry lake surfaces, no enhancement of the features studied was observed on the bands 4 and 5 subtraction images. Geologic and geographic features characterized by minor tonal differences on relatively flat surfaces were enhanced on some of the pseudocolor images.

  13. Late Quaternary geomorphology and soils in Crater Flat, Yucca mountain area, southern Nevada

    SciTech Connect

    Peterson, F.F.; Bell, J.W.; Ramelli, A.R.; Dorn, R.I.; Ku, T.L.

    1995-04-01

    Crater Flat is an alluvium-filled structural basin on the west side of Yucca Mountain, Nevada, which is under consideration for a high-level nuclear waste repository. North-trending, late Quaternary faults offset alluvium in Crater Flat both along the canyons of the western flanks of Yucca Mountain and out on the piedmont slope. We believe the initial lack of young offsets at Yucca Mountain was in part due to unrecognized late Quaternary stratigraphy. We hypothesize that alluviation in the Yucca Mountain region was more active during the late Quaternary than previously thought. Several techniques were tried to test this hypothesis. Results are compared with previous soils and surface-exposure dating studies, and correlated to stratigraphy of other late Quaternary units in the southern Nevada, Death Valley, and Mojave Desert areas, and provide new stratigraphic data relevant to understanding climatic-alluvial processes in the Basin and Range Province during the late Quaternary. 76 refs., 7 figs., 6 tabs.

  14. Potential field studies of the central San Luis Basin and San Juan Mountains, Colorado and New Mexico, and southern and western Afghanistan

    NASA Astrophysics Data System (ADS)

    Drenth, Benjamin John

    This dissertation includes three separate chapters, each demonstrating the interpretive utility of potential field (gravity and magnetic) geophysical datasets at various scales and in various geologic environments. The locations of these studies are the central San Luis Basin of Colorado and New Mexico, the San Juan Mountains of southwestern Colorado, and southern and western Afghanistan. The San Luis Basin is the northernmost of the major basins that make up the Rio Grande rift, and interpretation of gravity and aeromagnetic data reveals patterns of rifting, rift-sediment thicknesses, distribution of pre-rift volcanic and sedimentary rocks, and distribution of syn-rift volcanic rocks. Syn-rift Santa Fe Group sediments have a maximum thickness of ˜2 km in the Sanchez graben near the eastern margin of the basin along the central Sangre de Cristo fault zone. Under the Costilla Plains, thickness of these sediments is estimated to reach ˜1.3 km. The Santa Fe Group sediments also reach a thickness of nearly 1 km within the Monte Vista graben near the western basin margin along the San Juan Mountains. A narrow, north-south-trending structural high beneath San Pedro Mesa separates the graben from the structural depression beneath the Costilla Plains. Aeromagnetic anomalies are interpreted to mainly reflect variations of remanent magnetic polarity and burial depth of the 5.3-3.7 Ma Servilleta basalt of the Taos Plateau volcanic field. Magnetic-source depth estimates indicate patterns of subsidence following eruption of the basalt and show that the Sanchez graben has been the site of maximum subsidence. One of the largest and most pronounced gravity lows in North America lies over the rugged San Juan Mountains in southwestern Colorado. A buried, low-density silicic batholith related to an Oligocene volcanic field coincident with the San Juan Mountains has been the accepted interpretation of the source of the gravity low since the 1970s. However, this interpretation was

  15. Transpressional regime in southern Arabian Shield: Insights from Wadi Yiba Area, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Hamimi, Zakaria; El-Shafei, Mohamed; Kattu, Ghazi; Matsah, Mohammed

    2013-10-01

    Detailed field-structural mapping of Neoproterozoic basement rocks exposed in the Wadi Yiba area, southern Arabian Shield, Saudi Arabia illustrates an important episode of late Neoproterozoic transpression in the southern part of the Arabian-Nubian Shield (ANS). This area is dominated by five main basement lithologies: gneisses, metavolcanics, Ablah Group (meta-clastic and marble units) and syn- and post-tectonic granitoids. These rocks were affected by three phases of deformation (D1-D3). D1 formed tight to isoclinal and intrafolial folds (F1), penetrative foliation (S1), and mineral lineation (L1), which resulted from early E-W (to ENE-WSW) shortening. D2 deformation overprinted D1 structures and was dominated by transpression and top-to-the-W (-WSW) thrusting as shortening progressed. Stretching lineation trajectories, S-C foliations, asymmetric shear fabrics and related mylonitic foliation, and flat-ramp and duplex geometries further indicate the inferred transport direction. The N- to NNW-orientation of both “in-sequence piggy-back thrusts” and axial planes of minor and major F2 thrust-related overturned folds also indicates the same D2 compressional stress trajectories. The Wadi Yiba Shear Zone (WYSZ) formed during D2 deformation. It is one of several N-S trending brittle-ductile Late Neoproterozoic shear zones in the southern part of the ANS. Shear sense indicators reveal that shearing during D2 regional-scale transpression was dextral and is consistent with the mega-scale sigmoidal patterns recognized on Landsat images. The shearing led to the formation of the WYSZ and consequent F2 shear zone-related folds, as well as other unmappable shear zones in the deformed rocks. Emplacement of the syn-tectonic granitoids is likely to have occurred during D2 transpression and occupied space created during thrust propagation. D1 and D2 structures are locally overprinted by mesoscopic- to macroscopic-scale D3 structures (F3 folds, and L3 crenulation lineations and

  16. Description of piezometers installed in the middle Rio Grande basin area, 1997-99, central New Mexico

    USGS Publications Warehouse

    Bartolino, J.R.; Rankin, D.R.

    2000-01-01

    Since 1993, the Santa Fe Group aquifer system in the Middle Rio Grande Basin, and particularly in the Albuquerque area, has been the focus of studies to further define the extent of the most productive parts of the aquifer and to gain a better understanding of how ground- water levels are changing over time. The U.S. Geological Survey, in cooperation with the New Mexico Office of the State Engineer, installed nine piezometers during 1998-99 at five sites in and near the margin of the Middle Rio Grande Basin in central New Mexico. In addition, the New Mexico Office of the State Engineer installed another nine piezometers at three sites during 1997. These piezometers allow for collection of ground-water-level data in areas for which little information is available. Most of the piezometers were constructed of 2.5-inch-diameter flush-joint polyvinyl chloride (PVC) schedule 80 casing with 10-foot stainless steel screens; the shallow piezometer at the Tome site has a 40-foot screen, and the single piezometers at the Dome Road and Phoenix Road sites have steel casing with welded joints and a 10- and a 20-foot screen, respectively. Steel casing with a locking lid covers the uppermost 2 feet of the piezometer casing. Drillers' logs and petrophysical logs were collected from the deepest borehole at each site.

  17. Temporal variation and impact of wood smoke pollution on a residential area in southern Germany

    NASA Astrophysics Data System (ADS)

    Bari, Md. Aynul; Baumbach, Guenter; Kuch, Bertram; Scheffknecht, Guenter

    2010-10-01

    This paper is a continuation of our previous publication (Bari, M.A., Baumbach, G., Kuch, B., Scheffknecht, G., 2009. Wood smoke as a source of particle-phase organic compounds in residential areas. Atmospheric Environment 43, 4722-4732) and describes a detailed characterisation of different particle-phase wood smoke tracer compounds in order to find out the impact of wood-fired heating on ambient PM 10 pollution in a residential area near Stuttgart in southern Germany. The results from previous flue gas measurements help distinguishing different tracer compounds in ambient PM 10 samples. In the residential area, significant amounts of hardwood markers (syringaldehyde, acetosyringone, propionylsyringol, sinapylaldehyde) and low concentrations of softwood markers (vanillin, acetovanillone, coniferyldehyde, dehydroabietic acid, retene) were found in the ambient air. The general wood combustion markers Levoglucosan, mannosan and galactosan were detected in high concentrations in all particle-phase PM 10 samples. To find out the size distribution of ambient particles, cascade impactor measurements were carried out. It was found that more than 70% of particulate matter was in the particle diameter of less than 1 μm. Using emission ratio of levoglucosan to PM 10, it can be demonstrated that during winter months 59% of ambient PM 10 pollution could be attributed to residential wood-fired heating.

  18. Paleomagnetism, rock magnetism and opaque mineralogy of iron ore deposits from southern Mexico and their implications for quantitative modelling of magnetometric data

    SciTech Connect

    Alva-Valdivia, L.M.; Fucugauchi, Urrutia, J.; Bohnel, H.; Moran Zenteno, D.J. )

    1990-06-01

    Paleomagnetism, Rock Magnetism and Opaque Mineralogy of Iron Ore Deposits from Southern Mexico and Their Implications for Quantitative Modelling of Magnetometric Data. The tectonic history of the Pacific continental margin is critical for understanding their mineral deposits. The margin presents intrusive and volcanic activity characteristic of magmatic arcs of subduction zones, which are genetically related with deposits of Cu, Fe, Mo, Au, and Ag. Although the tectonic history has been complex, involving oblique plate subduction, lateral movements, accretion of magmatic arcs and oceanic plateaux, and lateral displacements of major blocks, the mineral deposits are spatially distributed along elongated belts that roughly follow the margin. The authors have conducted paleomagnetic, rock magnetic, and petrological studies of the iron ore deposits to investigate genesis, magnetic mineralogy, stratigraphic relationships, metamorphism, and applications on quantitative modelling of magnetometric data. The remanent magnetization and susceptibility data are necessary for interpretation of magnetic anomalies. The results permit a comparison of the mineral deposits along the continental margin.

  19. [The focal control of malaria. Focal treatment using chemoprophylaxis and home insecticide spraying for the control of malaria in southern Mexico].

    PubMed

    Rodríguez López, M H; Loyola Elizondo, E G; Betanzos Reyes, A F; Villarreal Treviño, C; Bown, D N

    1994-01-01

    The efficacy of a focal control strategy for malaria was evaluated against a conventional scheme carried out in two groups of villages in the Soconusco, southern Chiapas, Mexico. Focal control consisted on the prophylactic administration of antimalarial drugs to people who had experienced malaria episodes two years previous to the study. Homes of these malaria patients were also sprayed indoors with DDT. The traditional strategy consisted on the treatment of all patients with antimalarial drugs as well as indoor spraying with DDT of all houses in the villages. Results from the focal control demonstrated similar efficacy as compared to conventional. However, in terms of cost, focal control was four fold more economical. Focal control had an additional advantage of incorporating community participation within the control operations. PMID:7607360

  20. Mineral resource potential map of the lower San Francisco Wilderness study area and contiguous roadless area, Greenlee County, Arizona and Catron and Grant Counties, New Mexico

    USGS Publications Warehouse

    Ratte, James C.; Hassemer, Jerry R.; Martin, Ronny A.; Lane, Michael

    1982-01-01

    The Lower San Francisco Wilderness Study Area consists of a narrow strip 1-2 mi (2-3 km) wide between the rims of the San Francisco River canyon. The wilderness study area has a moderately high potential for geothermal resources, a low to moderate potential for base metal or precious metal resources in middle to upper Tertiary volcanic rocks, essentially no oil, gas, or coal potential, and a largely unassessable potential for metal deposits related to Laramide igneous intrusions in pre-Tertiary or lower Tertiary rocks that underlie the area. The contiguous roadless area, which borders the New Mexico half of the wilderness study area, mainly on the north side of the San Francisco River, has a low to moderate potential for molybdenum or copper deposits related to intrusive igneous rocks in the core of a volcano of dacitic composition at Goat Basin.

  1. Obstacle-related contourites in the El Arraiche area, southern Gulf of Cádiz.

    NASA Astrophysics Data System (ADS)

    Vandorpe, T.; Van Rooij, D.; Martins, I.; Hebbeln, D.

    2014-12-01

    The El Arraiche area is situated in the southern part of the Gulf of Cádiz, roughly between 35° and 35°45' north and 6°30' and 7°15' west. This area contains mud volcanoes, cold-water coral (CWC) mounds, contourite drifts and tectonic ridges (Fig. 1). CWC mounds are present both on top and at the foot of the Pen Duick Escarpment (Van Rooij et al., 2011; Vandorpe et al., 2014), but recent multibeam and seismic data indicate the ubiquitous presence of small mounds both buried and on the seafloor (Fig.1). Information regarding the environmental conditions in which these ecosystems thrived can be derived from the nearby contourite systems, as they contain an oceanographic as well as a climatic imprint. In this area, all of the topographic features interfere with the contourite deposits. The Quaternary Pen Duick drift for example displays pinch-out due to the uplifting Pen Duick Escarpment (Fig. 1), a Christmas-tree structure due to the outflow of mud from the nearby Gemini Mud Volcano and CWC mounds are present in certain parts of the moat (Vandorpe et al., 2014). Increased bottom currents are observed at the foot of the Pen Duick Escarpment, Renard ridge and Vernadsky ridge (up to 10 cm/s). As mounded drift deposits start occurring after the Mid-Pleistocene Revolution in the Pen Duick drift, enhanced bottom currents may be present from then onwards. The presence of (modified) Antarctic Intermediate Water (AAIW) is inferred (Vandorpe et al. (2014) and references therein) and likely contributes to the formation of the Pen Duick drift, while Mediterranean Outflow Water is only present at greater water depths (from 900 meter onwards). The formation of the other drift systems is the subject of ongoing research. Van Rooij, D., Blamart, D., De Mol, L., Mienis, F., Pirlet, H., Wehrmann, L.M., Barbieri, R., Maignien, L., Templer, S.P., de Haas, H., Hebbeln, D., Frank, N., Larmagnat, S., Stadnitskaia, A., Stivaletta, N., van Weering, T., Zhang, Y., Hamoumi, N., Cnudde, V

  2. CO2 Fluxes and Concentrations in a Residential Area in the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Weissert, L. F.; Salmond, J. A.; Turnbull, J. C.; Schwendenmann, L.

    2014-12-01

    While cities are generally major sources of anthropogenic carbon dioxide (CO2) emissions, recent research has shown that parts of urban areas may also act as CO2 sinks due to CO2 uptake by vegetation. However, currently available results are related to a large degree of uncertainty due to the limitations of the applied methods and the limited number of studies available from urban areas, particularly from the southern hemisphere. In this study, we explore the potential of eddy covariance and tracer measurements (13C and 14C isotopes of CO2) to quantify and partition CO2 fluxes and concentrations in a residential urban area in Auckland, New Zealand. Based on preliminary results from autumn and winter (March to July 2014) the residential area is a small source of CO2 (0.11 mol CO2 m-2 day-1). CO2 fluxes and concentrations follow a distinct diurnal cycle with a morning peak between 7:00 and 9:00 (max: 0.25 mol CO2 m-2 day-1/412 ppm) and midday low with negative CO2 fluxes (min: -0.17 mol CO2 m-2 day-1/392 ppm) between 10:00 and 15:00 local time, likely due to photosynthetic CO2 uptake by local vegetation. Soil CO2 efflux may explain that CO2 concentrations increase and remain high (401 ppm) throughout the night. Mean diurnal winter δ13C values are in anti-phase with CO2 concentrations and vary between -9.0 - -9.7‰. The depletion of δ13C compared to clean atmospheric air (-8.2‰) is likely a result of local CO2 sources dominated by gasoline combustion (appr. 60%) during daytime. A sector analysis (based on prevailing wind) of CO2 fluxes and concentrations indicates lower CO2 fluxes and concentrations from the vegetation-dominated sector, further demonstrating the influence of vegetation on local CO2 concentrations. These results provide an insight into the temporal and spatial variability CO2 fluxes/concentrations and potential CO2 sinks and sources from a city in the southern hemisphere and add valuable information to the global database of urban CO2 fluxes.

  3. Exploring for hydrocarbons in geothermally and hydrothermally complex areas -- a southern Nevada example

    SciTech Connect

    Harris, A.G.; Repetski, J.E.; Grow, J.A.

    1995-06-01

    Time-based isograd maps using conodont color alteration indices (CAI) have been compiled and interpreted for a large area in southern Nevada that includes Yucca Mountain, the Nevada Test Site, and the Nellis Air Force Bombing and Gunnery Range. These maps were produced to evaluate the controversy about possible important mineral and (or) energy resources near Yucca Mountain, the potential burial site for high-level nuclear waste. The hydrocarbon potential of the Yucca Mountain area has been likened to that of the Railroad and Pine Valley areas, 200 km to the northeast where 35 million barrels of oil have been produced from Paleozoic and lower Tertiary strata. In 1991, two companies with no previous drilling experience in Nevada drilled three oil exploration wells within 20 km of Yucca Mountain and within or close to the Timber Mountain caldera system. No shows of oil or gas were found in these wells. The deepest well was drilled to 5,000 feet and penetrated 2,200 feet of upper Tertiary valley-fill deposits and volcanic rocks overlying an overturned sequence of Upper Cambrian and Lower Ordovician rocks having conodonts with CAI values of 5. Our new conodont sampling, however, has targeted some thermally favorable areas for hydrocarbons east of Yucca mountain, but their maturation history suggests that the potential for oil is substantially lower than in the Railroad and Pine Valley areas. Cambrian through Triassic rocks in the vicinity of Yucca Mountain have experienced temperatures too high for oil to be preserved, except for a narrow zone (20 x 100 km) northeast of Yucca Mountain, where Mississippian through Triassic rocks are just within the upper limit of the oil generating window. Most of this zone, however, lies on Federal lands that are, for now, inaccessible for a variety of security and environmental reasons.

  4. Geochronology and geochemistry of late Cenozoic basalts from the Leiqiong area, southern China

    NASA Astrophysics Data System (ADS)

    Ho, Kung-suan; Chen, Ju-chin; Juang, Wen-shing

    2000-06-01

    The Leiqiong area, which includes the Leizhou Peninsula and the northern part of the Hainan Island, is the largest province of exposed basalts in southern China. Ar-Ar and K-Ar dating indicates that incipient volcanism in the Leiqiong area may have taken place in late Oligocene time and gradually increased in tempo toward the Miocene and Pliocene Epoch. Volcanic activities were most extensive during Pleistocene, and declined and ended in Holocene. Based on radiometric age dating and geographic distribution, Pliocene and Quaternary volcanism in Hainan Island can be grouped into two stages and six eruptive regions. The early volcanism is dominated by flood type fissure eruption of quartz tholeiites and olivine tholeiites whereas the later phase is dominated by central type eruption of alkali olivine basalts and olivine tholeiites. The systematic decrease of MgO, ΣFeO and TiO 2 with increasing SiO 2 content for basalts from Hainan Island indicates that fractional crystallization of olivine, clinopyroxene and Ti-bearing opaques may have occurred during magmatic evolution. From coexisting Fe-Ti oxide minerals, it is estimated that the equilibrium temperatures range from 895-986°C and oxygen fugacities range from 10 -13.4 to 10 -10.7 atmospheres in the basaltic magmas. The incompatible element ratios and the chondrite-normalized REE patterns of basalts from the Leiqiong area are generally similar to OIB. The Nb/U ratios (less than 37) in most of the tholeiitic rocks and the negative Nb anomaly observed in the spidergram of some basalts indicated that the influence of a paleo-subduction zone derived component can not be excluded in considering the genesis of the basalts from the Leiqiong area. The tholeiites in the Leiqiong area may have mixed with a more enriched lithospheric mantle component as well as undergone relatively larger percentages of partial melting than the alkali basalts.

  5. Regional deformation analysis in the Sannio-Matese area (Southern Apennines, Italy) by GPS surveys

    NASA Astrophysics Data System (ADS)

    Obrizzo, Francesco; Sepe, Vincenzo; Brandi, Giuseppe; D'Alessandro, Andrea; de Martino, Prospero; Dolce, Mario; Tammaro, Umberto; Pingue, Folco

    2010-05-01

    The central-southern Apennines and the Calabrian arc are among the most actively deforming zones of the Mediterranean basin connected with the motion of Africa and Aegean-Anatolian systems with respect to Eurasia. The tectonic stress, caused in this area by the convergence of the confining blocks, is elastically accumulated and periodically released along crustal discontinuities (faults) during earthquakes. A detailed knowledge of the ongoing crustal strain rates is fundamental to constrain geodynamical models of the Italian peninsula and to understand the characteristics of the active tectonic stress release. Given the low deformation rates in the Central Mediterranean area, only a long-term monitoring can yield the necessary data set to model and understand the ongoing tectonic processes. The Matese carbonatic massive occupies a surface of beyond 1000 km2 between the Campania Apennine northernmost part while Monti del Sannio, consisting primarily of quaternary deposits. It is located to the East of massive and represent the area of Apennine chain which degrades to East towards the Bradanica foredeep and it's delimited, in its complex, from Volturno, Biferno, Tammaro and Calore rivers. The area was interested in historical events by several destructive earthquakes with an Intensity I greater or equal than IX MCS (1456, 1688, 1702, 1732, 1805, 1962), besides by seismic sequences of low energy (1885, 1903, 1905, 1990, 1992, 1997). The first studies surveying the area started from 1990-2000 with the definition of geodetic networks, covering all or part of the massive Matese, with the aim of the evaluation of seismogenic sources responsible for the seismicity of the area. A preliminary study from the geological and structural point of view was focused on the area extending among Benevento, Campobasso, Caserta, Isernia and L'Aquila provinces, in order to accurately define the sites in which the vertices of the network could be installed. After a careful inspection of

  6. Atmospheric variability and its relationship with winter precipitation over Mexico and Southern USA in the 21st Century from CORDEX RegCM4 simulations

    NASA Astrophysics Data System (ADS)

    Fuentes-Franco, Ramon; Pavia, Edgar; Giorgi, Filippo; Graef, Federico; Coppola, Erika

    2014-05-01

    We study the relationship between atmospheric variability modes (MAVs) obtained from empirical orthogonal functions of 500 hPa geopotential height anomalies and winter precipitation over Mexico and Southern USA. The annual cycle and interanual variability of precipitation from four RegCM4 present-period simulations using different configurations are evaluated as prior step to analyse future projections for the 21st century. The model ability to reproduce the MAVs is also assessed by comparing with ERA-Interim reanalysis. The dominant MAV in the projections is an inhomogeneous atmospheric expansion which induces a future change in the atmospheric circulation by favoring inland advecion of oceanic humidity, and therefore increasing precipitation over the Northwest of Mexico and Southwest USA. The second AVM represents a dipole of zonal expansion-compression which apparently modulates interannual precipitation variability in our region of study. This second mode is actually accountable for the occurrence of very wet and very dry winters in this region; and therefore the increase of the interanual varibility of this MAV is responsable for the projected increase in interannual variability of winter precipitation.

  7. Old and juvenile source of Paleozoic and Mesozoic basaltic magmas in the Acatlán and Ayú complexes, Southern Mexico: Nd isotopic constraints

    NASA Astrophysics Data System (ADS)

    Keppie, J. Duncan; Dostal, Jaroslav; Shellnutt, J. Gregory

    2016-06-01

    The Neoproterozoic-Paleozoic Acatlán Complex and the Mesozoic Ayú Complex of southern Mexico consist of clastic rocks and rift-related igneous rocks inferred to have originated along a rifted passive margin in southwestern Mexico, either in an inactive (Neoproterozoic-Ordovician) or an active (Devonian-Carboniferous and Triassic-Early Jurassic) tectonic setting. The latter formed on the inner margin of a backarc basin. These passive margin rocks were partly underthrust beneath the Acatlán Complex, into which they were subsequently extruded: extrusion was synchronous with the backarc basin development. Thus, (i) the Neoproterozoic-Ordovician rocks underwent underthrusting, high-pressure metamorphism, and extrusion during the Late Devonian-Carboniferous (365-330 Ma); (ii) the Carboniferous rocks underwent underthrusting, amphibolite facies metamorphism, and extrusion during the Permian and Triassic; and (iii) the Triassic-Lower Jurassic rocks underwent underthrusting, amphibolite facies metamorphism, and extrusion during the Jurassic. Nd isotopic data from tholeiitic mafic rocks on either side of the HP extrusion zone reveal that both were underlain by similar peri-Rodinian subcontinental lithospheric mantle in the Neoproterozoic-Ordovician, which was supplemented in the Devonian-Carboniferous and Triassic-Early Jurassic by a juvenile depleted mantle source. The alternation of underthrusting and backarc rifting accompanied by extrusion may be related to flattening and steepening of the Beniof zone, respectively.

  8. Deep-water bivalve mollusks collected during the TALUD XV cruise off the west coast of the southern Baja California Peninsula, Mexico

    PubMed Central

    Valentich-Scott, Paul; Suárez-Mozo, Nancy Yolimar

    2016-01-01

    Abstract Background During the TALUD XV research cruise off the southern part of the Baja California Peninsula, Mexico, samples of macro-invertebrates obtained in the deep-sea (296–2136 m) revealed a rich fauna of bivalves (17 species belonging to 10 families). The number of species per station varied from one to five. The richest families were Nuculidae, Nuculanidae, Neilonellidae, Limidae, and Cuspidariidae. Solemyidae, Lucinidae, Poromyidae, Verticordiidae, and Pectinidae were each represented by a single species. Some species groups need a thorough revision and were tentatively identified (Nuculana cf. hamata, Limatula cf. saturna). New information Significant new distribution information is provided for two species, both recorded for the first time from off western Mexico: Ennucula panamina with an extension of its known distribution over 20° of latitude north and Jupiteria callimene with an extension of 16° 42' of latitude to the north. One species (Ennucula taeniolata) is reported in shallower depth and one in deeper water (Acesta sphoni). New records are provided for an additional nine species. Environmental and habitat conditions are given for the first time for many of the bivalve species. PMID:27346956

  9. Influence of climate variability and urban areas on the flood events in Bari (Apulia, southern Italy)

    NASA Astrophysics Data System (ADS)

    Lonigro, Teresa; Polemio, Maurizio

    2014-05-01

    The Damaging Hydrogeological Events (DHEs) can be defined as the occurrence of one or more simultaneous phenomena, such as droughts, windstorms, heat waves, landslides, floods and secondary floods (i.e. rapid accumulation or pounding of surface water with very low flow velocity), causing damages. They represent a serious problem, especially in DHE-prone areas with growing urbanization, where the infiltration capability is limited by buildings and where the vulnerability is higher than other areas. The paper proposes a methodology, based on both historical and time series approaches, used for describing the influence of climatic variability and urban development on the number of phenomena observed. The historical approach is finalised to collect phenomenon historical data, very important for the comprehension of the evolution of a study area. Phenomenon historical data is useful for expanding the historical period of investigation in order to assess the occurrence trend of DHEs. The historical analysis of DHEs can support decision making and land-use planning, ultimately reducing natural risks. The time series approach includes the collection and the statistical analysis of climatic data (monthly rainfall, wet days, rainfall intensity, and temperature), useful to characterise the climate variations and trends and to roughly assess the effects of these trends on river discharge and on the triggering of landslides. The time series approach is completed by tools to analyse simultaneously all data types. The study of land use variations, with a special emphasis on the urban areas, is important to understand how the modifications occurred in the territory, especially in terms of vulnerability, could influence the occurrence of DHEs. The methodology can be applied simultaneously to floods and landslides and was tested considering the municipality of Bari (southern Italy), particularly affected by flood events. Since the climate trend (decreasing trend of rainfall and

  10. Assessment of heavy metal contamination in soils around Manali industrial area, Chennai, Southern India

    NASA Astrophysics Data System (ADS)

    Krishna, A. K.; Govil, P. K.

    2008-06-01

    The concentrations of heavy metals (As, Ba, Co, Cr, Cu, Ni, Mo, Pb, Sr, V and Zn) were studied in soils to understand metal contamination due to industrialization and urbanization around Manali industrial area in Chennai, Southern India. This area is affected by the industrial activity and saturated by industries like petrochemicals, refineries, and fertilizers generating hazardous wastes. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Soil samples were collected from the industrial area of Manali from the top 10-cm-layer of the soil. Soil samples were analyzed for heavy metals by using Philips MagiX PRO-2440 Wavelength dispersive X-ray fluorescence spectrometry. The data revealed elevated concentrations of Chromium (149.8-418.0 mg/kg), Copper (22.4-372.0 mg/kg), Nickel (11.8-78.8 mg/kg), Zinc (63.5-213.6 mg/kg) and Molybdenum (2.3-15.3 mg/kg). The concentrations of other elements were similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high-EFs for some heavy metals obtained in the soil samples show that there is a considerable heavy metal pollution, which could be correlated with the industries in the area. Contamination sites pose significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems. In this perspective there is need for a safe dumping of waste disposal in order to minimize environmental pollution.

  11. Exposure of children to air pollution in the industrial zone of Metropolitan Area of Mexico City

    NASA Astrophysics Data System (ADS)

    Mugica-Alvarez, Violeta; Quintanilla-Vega, Betsabé; De Vizcaya-Ruiz, Andrea; Alvarado-Cruz, Isabel

    2016-04-01

    An air quality monitoring in three schools located in the most important industrial zone at the Northeast of the Metropolitan Area of Mexico City (MAMC) was conducted in order to determine the exposure of children to toxics contained in PM10. Particles were analyzed for metals, polycyclic aromatic hydrocarbons (PAH), organic and elemental carbon by ICP-AES, GC-MS and TOT (Sunset lab) respectively. Average concentration of PM10 was 108.4±11.6 μg/m3. Most abundant metals were Fe, Zn and Pb with concentrations ranged by 1.1-5.4 μg/m3, 0.3-2 μg/m3, and 0.18-0.63 μg/m3 respectively; the sum of the seventeen PAHs varied from 1.4 to 3.3 ng/m3 where most abundant PAH were indene[1,2,3-c,d]pyrene, benzo[b]fluoranthene, benzo[a]anthracene, chrysene, and benzo[a]pyrene. The sum of the seven carcinogenic PAH contributed in average with the 48% of the total mixture. Carcinogenic potential of PAH were obtained using toxic equivalent factors determined by Nisbet and La Goy which varied from 0.3 to 0.6 ng/ m3 of benzo[a]pyrene equivalent (BAPeq), this value is lower than the standard proposed for the European Community of 1 ng/ m3, but higher than the standard from the United Kingdom of 0.25 ng/ m3. Principal component analysis for source apportionment showed that vehicular and industrial emissions are the main sources of PM in the zone. In general, the concentrations of particles as well as concentration of metals and PAHs are lower than concentrations measured six year before, showing that the established measures have improved the air quality. Nevertheless these PM10 concentrations exceeded frequently the Mexican Standard and children are especially susceptible due to the higher risk to develop diseases if the exposure occurs at early age.

  12. Evaluation of a Three-Dimensional Chemical Transport Model (PMCAMx) in the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Tsimpidi, A. P.; Karydis, V. A.; Zavala, M.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2007-05-01

    Atmospheric aerosols have adverse effects on human health, contribute to the visibility reduction and influence the energy balance of the planet. A three-dimensional chemical transport model (PMCAMx) (Gaydos et al., 2007) is used to simulate the particular matter (PM) mass composition distribution in the Mexico City Metropolitan Area (MCMA). PMCAMx uses the framework of CAMx (ENVIRON, 2002) modelling the processes of horizontal and vertical advection, horizontal and vertical dispersion, wet and dry deposition, and gas-phase chemistry. In addition to the above, PMCAMx includes three detailed aerosol modules: inorganic aerosol growth (Gaydos et al., 2003; Koo et al., 2003a), aqueous-phase chemistry (Fahey and Pandis, 2001), and secondary organic aerosol formation and growth (Koo et al., 2004). The aerosol thermodynamic model ISORROPIA has been improved as it now simulates explicitly the chemistry of Ca, Mg, and K salts and is linked to PMCAMx. The hybrid approach (Koo et al., 2003b) for modelling aerosol dynamics is applied in order to accurately simulate the inorganic components in coarse mode. This approach assumes that the smallest particles are in equilibrium while the condensation/evaporation equation is solved for the larger ones. The new CMU organic aerosol model, which is based on the splitting of the organic aerosol volatility range in discrete bins, is also used. The model predictions are evaluated against the PM and vapour concentration measurements from the MCMA-2003 Campaign (Molina et al., 2007). References Gaydos, T., Pinder, R., Koo, B., Fahey, Κ., Yarwood, G., and Pandis, S. N., (2007). Development and application of a three-dimensional Chemical Transport Model, PMCAMx. Atmospheric Environment, in press. ENVIRON (2002). User's guide to the comprehensive air quality model with extensions (CAMx). Version 3.10. Report prepared by ENVIRON International corporation, Novato, CA Gaydos, T., Koo, B., and Pandis, S. N., (2003). Development and application of

  13. Risk of Giardia intestinalis infection in children from an artificially recharged groundwater area in Mexico City.

    PubMed

    Cifuentes, Enrique; Suárez, Leticia; Espinosa, Martha; Juárez-Figueroa, Luis; Martínez-Palomo, Adolfo

    2004-07-01

    The objective of this study was to assess the risk of infection with Giardia intestinalis in children living in an area with artificial groundwater recharge and potable water reuse in Mexico City. Eligible wells and surrounding homesteads were defined by using a geographic information system. Five wells were tested for G. intestinalis cysts per 400 liters of water. A total of 750 eligible households were visited during two cross-sectional surveys. Stool samples were provided by 986 children in the rainy season study and 928 children during the dry season survey for parasitologic tests. Their guardians provided information on water, sanitation, hygiene, and socioeconomic variables. The prevalence rates of G. intestinalis infection were 9.4% in the rainy season and 4.4% in the dry season. Higher rates of infection were observed in older individuals (9.5% and 10.6%) and girls had a lower risk of infection than boys (odds ratio [OR] =0.55, 95% confidence interval [CI] = 0.34, 0.88 in the rainy season and OR = 0.47, 95% CI = 0.25, 0.90 in the dry season). During the wet season survey, a health risk was detected among those storing water in unprotected receptacles (OR = 4.00, 4.69, and 5.34 for those using uncovered jars, cisterns or tanks, and buckets, respectively), and bathing outside the dwelling, i.e., using a tap (OR = 1.93, 95% CI = 1.10, 3.39). A health risk was also detected among children from households with unsafe food hygiene practices (OR =2.41, 95% CI =1.10, 5.30) and those with no hand-washing habits (OR = 2.27, 95% CI = 1.00, 5.20). Groundwater reserves are at risk of fecal pollution, as indicated by the presence of G. intestinalis cysts. However, the endemic pattern of intestinal infection reflects low standards of personal hygiene and unsafe drinking water storage and food-related practices at household level. Prevention activities must address health education and environmental protection policies. PMID:15238691

  14. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    SciTech Connect

    Apel, E.; Springston, S.; Karl, T.; Emmons, L.; Flocke, F.; Hills, A. J.; Madronich, S.; Lee-Taylor, J.; Fried, A.; Weibring, P.; Walega, J.; Richter, D., Tie, X.; Mauldin, L.; Campos, T.; Sive, B.; Kleinman, L.; Springston, S., Zaveri, R.; deGouw, J.; Zheng, J.; Zhang, R.; Rudolph, J.; Junkermann, W.; Riemer, D. D.

    2009-11-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on 18 March and the NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the 19 March plume and to help interpret the OH

  15. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    SciTech Connect

    Apel, Eric; Emmons, L.; Karl, Thomas G.; Flocke, Frank M.; Hills, A. J.; Madronich, Sasha; Lee-Taylor, J.; Fried, Alan; Weibring, P.; Walega, J.; Richter, Dirk; Tie, X.; Mauldin, L.; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Sive, B.; Kleinman, Lawrence I.; Springston, S.; Zaveri, Rahul A.; Ortega, John V.; Voss, Paul B.; Blake, D. R.; Baker, Angela K.; Warneke, Carsten; Welsh-Bon, Daniel; de Gouw, Joost A.; Zheng, J.; Zhang, Renyi; Rudolph, Jochen; Junkermann, W.; Riemer, D.

    2010-01-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on March 18 and the NCAR C130 one day later on March 19. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the March 19 plume and to help interpret the OH

  16. Geohydrology and water resources of the Papago Farms--Great Plain area, Papago Indian Reservation, Arizona, and the upper Rio Sonoyta area, Sonora, Mexico

    USGS Publications Warehouse

    Hollett, Kenneth J.

    1985-01-01

    The Papago Farms-Great Plain and upper Rio Sonoyta study area includes about 490 square miles in south-central Arizona and north-central Sonora, Mexico. The area is characterized by a broad, deep, sediment-filled basin bounded by low, jagged fault-block mountains. The climate is arid to semiarid. The climate and abundant ground water provide favorable conditions for irrigated agriculture. Annual precipitation averages 5 to 8 inches per year on the desert floor. Runoff, which occurs as intermittent streamflow and sheetflow, is too short lived and too laden with suspended sediment to be a reliable source for irrigation or public supply. Nearly all the water used to irrigate more than 5,000 cultivated acres in the study area is withdrawn from the unconsolidated to partly consolidated basin fill. The ground water occurs in the deposits under unconfined (water-table) conditions with a saturated thickness that ranges from zero along the mountain fronts to more than 8,000 feet in the center of the basin. The amount of recoverable ground water in storage to a depth of 400 feet below the 1978-80 water table is estimated to be about 10 million acre-feet. Depths to water range from about 500 feet near the southern boundary of the study area to about 150 feet in the center of the study area. Ground water enters the area principally as underflow beneath the San Simon and Chukut Kuk Washes and as recharge along the mountain fronts. On the basis of model results, annual inflow to the ground-water system is estimated to be about 4,390 acre-feet. Ground water moves through the study area along paths that encircle a virtually impermeable unit in the basin center, termed 'the lakebed-clay deposits,' and moves westward to an outflow point beneath the Rio Sonoyta south of Cerro La Nariz. Rates of water movement range from less than I foot per year in clays to about 160 feet per year in well-sorted, coarse stream-channel deposits. Transmissivities along the basin margins range from 10

  17. BOREAS HYD-9 Hourly and Daily Rainfall Maps for the Southern Study Area

    NASA Technical Reports Server (NTRS)

    Eley, F. Joe; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Krauss, Terry S.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-9 team collected data on precipitation and streamflow over portions of the Northern Study Area (NSA) and Southern Study Area (SSA). This data set contains Cartesian maps of rain accumulation for one-hour and daily periods during the summer of 1994 over the SSA only (not the full view of the radar). A parallel set of one-hour maps for the whole radar view has been prepared and is available upon request from the HYD-09 personnel. An incidental benefit of the areal selection was the elimination of some of the less accurate data, because for various reasons the radar rain estimates degrade considerably outside a range of about 100 km. The data are available in tabular ASCII files. The HYD-09 hourly and daily radar rainfall maps for the SSA are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  18. Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil

    PubMed Central

    2009-01-01

    As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European. PMID:21637465

  19. Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil.

    PubMed

    Collet, Thais; Cristino, Alexandre Santos; Quiroga, Carlos Fernando Prada; Soares, Ademilson Espencer Egea; Del Lama, Marco Antônio

    2009-10-01

    As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European. PMID:21637465

  20. Microzooplankton community associated with phytoplankton blooms in the naturally iron-fertilized Kerguelen area (Southern Ocean).

    PubMed

    Christaki, Urania; Georges, Clément; Genitsaris, Savvas; Monchy, Sébastien

    2015-07-01

    The spatial and temporal community composition of microzooplankton (dinoflagellates and ciliates) was assessed in the Kerguelen area (Southern Ocean) during the KEOPS2 cruise in early spring (October-November) 2011. This naturally iron-fertilized region was characterized by a complex mesoscale circulation resulting in a patchy distribution of phytoplankton blooms. Collectively, 97 morphospecies of dinoflagellates and ciliates belonging to 41 genera were identified by microscopy, and 202 Alveolata-related OTUs (operational taxonomical units) were retrieved with tag-pyrosequencing. Microscopy and pyrosequencing data were in accordance, in that diatom-consuming dinoflagellates were the most enhanced taxa in the blooms. Dinoflagellates also showed significant positive relationships with phytoplankton pigments, while no major differences were found in the ciliate abundances inside and outside the blooms. Cluster analysis showed clear differences in the phytoplankton and microzooplankton community structures between the iron-fertilized and HNLC (high nutrient low chlorophyll) waters, and between the blooms, concerning their location and the fertilization mechanisms. These results were combined with the rates of primary production and mesozooplankton consumption determined for the study area. The potential role of dinoflagellates and ciliates as phytoplankton consumers and as prey for mesozooplankton was then evaluated. Overall, heterotrophic dinoflagellates were probably the most important group of phytoplankton grazers, and a potential food source for copepods. PMID:26099964

  1. Petroleum systems of the Southeast Tertiary basins and Marbella area, Southeast Mexico

    SciTech Connect

    Fuentes, F. |

    1996-08-01

    This study was done in an area where insufficient organic-rich rocks were available for a reliable oil-source rock correlation. However, oil-rock correlations, molecular characteristics of key horizons, paleofacies maps, maturation and potential migration pathways suggest the Tithonian as a major source rock. Moreover, there is good evidence of high quality source rocks in Oxfordian, Kimmeridgian, Middle-Upper Cretaceous and Paleogene (mainly in the Eocene). Plays were identified in Upper Jurassic oolitic sequences, Early-Middle Cretaceus carbonate platform rocks and breccias, Late Cretaceous basinal fracture carbonates, Paleogene carbonates and breccias, Early-Middle Miocene mounds and submarine fans and isolated carbonate platform sediments and Miocene-Recent turbidites. Seal rocks are shaly carbonates and anhydrites from Tithonian, basinal carbonates and anhydrites from Middle-Upper Cretaceous, basinal carbonates and marls from Upper Cretaceous and Paleogene shales, and bathyal shales from Early Miocene-Recent. The first phase of oil migration from upper Jurassic-Early Cretaceous source rocks occurred in the Early-Middle Cretaceous. In the Upper Cretaceous the Chortis block collided with Chiapas, and as a result mild folding and some hydrocarbons were emplaced to the structural highs. The main phase of structuration and folding of the Sierra de Chiapas started in the Miocene, resulting in well-defined structural traps. Finally, in Plio-Pleistocene the Chortis block was separated, the major compressional period finished and the southern portion of Sierra de Chiapas was raised isostatically. As a result of major subsidence, salt withdrawal and increased burial depth, conditions were created for the generation of liquid hydrocarbons from the Paleogene shales.

  2. Postwildfire preliminary debris flow hazard assessment for the area burned by the 2011 Las Conchas Fire in north-central New Mexico

    USGS Publications Warehouse

    Tillery, Anne C.; Darr, Michael J.; Cannon, Susan H.; Michael, John A.

    2011-01-01

    The Las Conchas Fire during the summer of 2011 was the largest in recorded history for the state of New Mexico, burning 634 square kilometers in the Jemez Mountains of north-central New Mexico. The burned landscape is now at risk of damage from postwildfire erosion, such as that caused by debris flows and flash floods. This report presents a preliminary hazard assessment of the debris-flow potential from 321 basins burned by the Las Conchas Fire. A pair of empirical hazard-assessment models developed using data from recently burned basins throughout the intermountain western United States was used to estimate the probability of debris-flow occurrence and volume of debris flows at the outlets of selected drainage basins within the burned area. The models incorporate measures of burn severity, topography, soils, and storm rainfall to estimate the probability and volume of debris flows following the fire. In response to a design storm of 28.0 millimeters of rain in 30 minutes (10-year recurrence interval), the probabilities of debris flows estimated for basins burned by the Las Conchas Fire were greater than 80 percent for two-thirds (67 percent) of the modeled basins. Basins with a high (greater than 80 percent) probability of debris-flow occurrence were concentrated in tributaries to Santa Clara and Rio del Oso Canyons in the northeastern part of the burned area; some steep areas in the Valles Caldera National Preserve, Los Alamos, and Guaje Canyons in the east-central part of the burned area; tributaries to Peralta, Colle, Bland, and Cochiti canyons in the southwestern part of the burned area; and tributaries to Frijoles, Alamo, and Capulin Canyons in the southeastern part of the burned area (within Bandelier National Monument). Estimated debris-flow volumes ranged from 400 cubic meters to greater than 72,000 cubic meters. The largest volumes (greater than 40,000 cubic meters) were estimated for basins in Santa Clara, Los Alamos, and Water Canyons, and for two

  3. Susceptibility of three laboratory strains of Anopheles albimanus (Diptera: Culicidae) to coindigenous Plasmodium vivax in southern Mexico.

    PubMed

    Chan, A S; Rodríguez, M H; Torres, J A; Rodríguez, M del C; Villarreal, C

    1994-05-01

    Three morphologically different pupal phenotypes (green, striped, brown) were selected from a parent strain of Anopheles albimanus Wiedemann collected from the Suchiate region in the state of Chiapas, Mexico. Significant differences in susceptibility to coindigenous Plasmodium vivax Grassi & Feletti were observed when striped was compared with the parent colony as well as with brown and with green phenotypes. Differences in susceptibility were not significant between the other phenotypes and the parent colony. PMID:8057314

  4. Air quality assessment in the periurban area of Mexico Megacity during dry hot season in 2011 and 2012

    NASA Astrophysics Data System (ADS)

    Garcia-Reynoso, Agustin; Santos Garcia-Yee, Jose; Barrera-Huertas, Hugo; Gerardo Ruiz-Suárez, Luis

    2016-04-01

    Air quality is a human health threat not only in urbanized areas, it also affects the surrounding zones. Interaction between urban and rural areas can be evaluated by measurements and using models for regional areas that includes in its domain the peri-urban regions. The use of monitoring sites in remote areas is useful however it is not possible to cover all the region the use of models can provide valuable information about the source and fate of the pollution and its transformation. In order to evaluate the influence of the Mexico Megacity in the air quality of the region, two field campaigns were performed during the dry hot season during 2011 and 2012. Meterological and pollutant measurements were made during February and march 2011, in three sites towards the south east of Mexico Megacity, and from march to April 2012 towards the west after the Popocatepetl-Iztaccihuatl mountain range. Air quality modeling were performed by using the National Emissions Inventory 2008 during the studied periods, a comparison between measurements and the air quality model was performed. This type of studies can offer information about the pollutant distribution, the meteorological conditions and the exactness of emissions inventories. The latest can be useful for emissions inventory developers and policy makers.

  5. Multibeam mapping of selected areas of the outer continental shelf, northwestern Gulf of Mexico; data, images, and GIS

    USGS Publications Warehouse

    Gardner, James V.; Beaudoin, Jonathan D.; Hughes-Clarke, John E.; Dartnell, Peter

    2002-01-01

    Following the publication of high-resolution (5-meter spatial resolution) multibeam echosounder (MBES) images of the Flower Garden Banks National Marine Sanctuary area of the northwestern Gulf of Mexico (Gardner et al., 1998), the Flower Garden Banks National Marine Sanctuary (FGBNMS) and the Minerals Management Service (MMS) have been interested in additional MBES data in the area. A coalition of FGBNMS, MMS, and the U.S. Geological Survey (USGS) was formed to map additional areas of interest in the northwestern Gulf of Mexico (fig. 1) in 2002. FGBNMS chose the survey areas, and the USGS chose the MBES. MMS and FGBNMS funded the mapping, and the USGS organized the ship and multibeam systems through a cooperative agreement between the USGS and the University of New Brunswick. The objective of the cruise was to map 12 regions of interest to MMS and the FGBNMS, including Alderdice, Sonnier, Geyer, Bright, Rankin (1 and 2), Jakkula, McNeil, Bouma, McGrail, Rezak, and Sidner Banks.

  6. Steps Towards the Implementation of a Tsunami Detection, Warning, Mitigation and Preparedness Program for Southwestern Coastal Areas of Mexico

    NASA Astrophysics Data System (ADS)

    Farreras, Salvador; Ortiz, Modesto; Gonzalez, Juan I.

    2007-03-01

    The highly vulnerable Pacific southwest coast of Mexico has been repeatedly affected by local, regional and remote source tsunamis. Mexico presently has no national tsunami warning system in operation. The implementation of key elements of a National Program on Tsunami Detection, Monitoring, Warning and Mitigation is in progress. For local and regional events detection and monitoring, a prototype of a robust and low cost high frequency sea-level tsunami gauge, sampling every minute and equipped with 24 hours real time transmission to the Internet, was developed and is currently in operation. Statistics allow identification of low, medium and extreme hazard categories of arriving tsunamis. These categories are used as prototypes for computer simulations of coastal flooding. A finite-difference numerical model with linear wave theory for the deep ocean propagation, and shallow water nonlinear one for the near shore and interaction with the coast, and non-fixed boundaries for flooding and recession at the coast, is used. For prevention purposes, tsunami inundation maps for several coastal communities, are being produced in this way. The case of the heavily industrialized port of Lázaro Cárdenas, located on the sand shoals of a river delta, is illustrated; including a detailed vulnerability assessment study. For public education on preparedness and awareness, printed material for children and adults has been developed and published. It is intended to extend future coverage of this program to the Mexican Caribbean and Gulf of Mexico coastal areas.

  7. Munsell color analysis of Landsat color-ratio-composite images of limonitic areas in southwest New Mexico

    NASA Technical Reports Server (NTRS)

    Kruse, F. A.

    1985-01-01

    The causes of color variations in the green areas on Landsat 4/5-4/6-6/7 (red-blue-green) color-ratio-composite (CRC) images, defined as limonitic areas, were investigated by analyzing the CRC images of the Lordsburg, New Mexico area. The red-blue-green additive color system was mathematically transformed into the cylindrical Munsell color coordinates (hue, saturation, and value), and selected areas were digitally analyzed for color variation. The obtained precise color characteristics were then correlated with properties of surface material. The amount of limonite (L) visible to the sensor was found to be the primary cause of the observed color differences. The visible L is, is turn, affected by the amount of L on the material's surface and by within-pixel mixing of limonitic and nonlimonitic materials. The secondary cause of variation was vegetation density, which shifted CRC hues towards yellow-green, decreased saturation, and increased value.

  8. A spatially comprehensive, hydrometeorological data set for Mexico, the U.S., and Southern Canada 1950–2013

    PubMed Central

    Livneh, Ben; Bohn, Theodore J.; Pierce, David W.; Munoz-Arriola, Francisco; Nijssen, Bart; Vose, Russell; Cayan, Daniel R.; Brekke, Levi

    2015-01-01

    A data set of observed daily precipitation, maximum and minimum temperature, gridded to a 1/16° (~6 km) resolution, is described that spans the entire country of Mexico, the conterminous U.S. (CONUS), and regions of Canada south of 53° N for the period 1950–2013. The dataset improves previous products in spatial extent, orographic precipitation adjustment over Mexico and parts of Canada, and reduction of transboundary discontinuities. The impacts of adjusting gridded precipitation for orographic effects are quantified by scaling precipitation to an elevation-aware 1981–2010 precipitation climatology in Mexico and Canada. Differences are evaluated in terms of total precipitation as well as by hydrologic quantities simulated with a land surface model. Overall, orographic correction impacts total precipitation by up to 50% in mountainous regions outside CONUS. Hydrologic fluxes show sensitivities of similar magnitude, with discharge more sensitive than evapotranspiration and soil moisture. Because of the consistent gridding methodology, the current product reduces transboundary discontinuities as compared with a commonly used reanalysis product, making it suitable for estimating large-scale hydrometeorologic phenomena. PMID:26306206

  9. Hydrogeology of the Quitobaquito Springs and La Abra Plain area, Organ Pipe Cactus National Monument, Arizona, and Sonora, Mexico

    USGS Publications Warehouse

    Carruth, R.L.

    1996-01-01

    Quitobaquito Springs, in Organ Pipe Cactus National Monument near the south end of the northwestward-trending Quitobaquito Hills, are less than 0.25 mile north of the international boundary between the United States and Mexico. The National Park Service is concerned that the natural flow from Quitobaquito Springs might be reduced by ground-water withdrawals in the adjacent State of Sonora, Mexico. Quitobaquito and other nearby springs flow from a highly fractured granite that forms the Quitobaquito Hills. Fractures in the granitic intrusive rocks provide conduits for ground water to flow from an alluvial flow system along Aguajita Wash to a line of springs on the southwest side of Quitobaquito Hills. The chemical composition of water from all the springs is similar. Carbon-14 analysis of water from Quitobaquito Springs indicates that the spring water probably is between 500 and several thousand years old. Discharge at Quitobaquito Springs averaged 28 gallons per minute and ranged from 15 to 40 gallons per minute for 1981-92. Rainfall at two gages in the area of recharge to the northeast of Quitobaquito Hills averaged 6.6 inches per year during the 11-year monitoring program ending in September 1992. The lack of correlation between spring discharge and local rainfall indicates that local annual recharge may be small relative to the total quantity of ground water in storage. Surface-geophysical data indicate that a thin alluvial aquifer overlies the shallow crystalline rocks northeast of Quitobaquito Hills along Aguajita Wash. Results of the study indicate that the ground-water flow system along Aguajita Wash provides a source of water to the springs and may be hydraulically connected to the ground-water system that is pumped for agricultural purposes in Mexico. The altitude and low permeability of the granite bedrock near the international boundary, however, may provide a barrier to and (or) delay the effect of a northwestward propagation of water- level declines

  10. In situ measurements of speciated atmospheric mercury and the identification of source regions in the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Rutter, A. P.; Snyder, D. C.; Stone, E. A.; Schauer, J. J.; Gonzalez-Abraham, R.; Molina, L. T.; Márquez, C.; Cárdenas, B.; de Foy, B.

    2009-01-01

    In order to expand the currently limited understanding of atmospheric mercury source-receptor relationships in the Mexico City Metropolitan Area, real time measurements of atmospheric mercury were made at a downtown urban site, and a rural site on the outskirts of Mexico City, during March 2006. Numerous short-lived increases in particulate mercury (PHg) and reactive gaseous mercury (RGM) concentrations were observed at the urban site during the 17 day study, and less frequent increases in gaseous elemental mercury (GEM) concentrations were measured at both the urban and rural sites. The episodic increases observed were attributed to plume impacts from industrial point source emissions in and around Mexico City. Average concentrations and standard deviations measured during the study were as follows: i) urban site; PHg=187±300 pg m-3, RGM=62±64 pg m-3, GEM=7.2±4.8 ng m-3, and; ii) rural site; GEM=5.0±2.8 ng m-3. Several source regions of atmospheric mercury to the urban and rural sites were determined using Concentration Field Analysis, in which atmospheric mercury measurements were combined with back trajectory data to determine source regions. Only some source regions correlated to mercury emission sources listed in the Federal Pollutant Release and Transfer Register, leaving the rest unaccounted for. Contributions of anthropogenic mercury point sources in and around Mexico City to concentration averages measured at the urban site during the study were estimated to be: 93±3% of reactive mercury (PHg and RGM), and; 81±0.4% of GEM. Point source contributions to GEM measured at the rural site were 72±1%. GEM and reactive mercury (PHg+RGM) were not found to correlate with biomass burning at either of the measurement sites.

  11. In situ measurements of speciated atmospheric mercury and the identification of source regions in the Mexico City Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Rutter, A. P.; Snyder, D. C.; Stone, E. A.; Schauer, J. J.; Gonzalez-Abraham, R.; Molina, L. T.; Márquez, C.; Cárdenas, B.; de Foy, B.

    2008-07-01

    In order to expand the currently limited understanding of atmospheric mercury source-receptor relationships in the Mexico City Metropolitan Area, real time measurements of atmospheric mercury were made at a downtown urban site, and a rural site on the outskirts of Mexico City, during March, 2006. Numerous short-lived increases in particulate mercury (PHg) and reactive gaseous mercury (RGM) concentrations were observed at the urban site during the 17 day study, and less frequent increases in gaseous elemental mercury (GEM) concentrations were measured at both the urban and rural sites. The episodic increases observed were attributed to plume impacts from industrial point source emissions in and around Mexico City. Average concentrations and standard deviations measured during the study were as follows: i) Urban site: PHg=187±300 pg m-3, RGM=62±64 pg m-3, GEM=7.2±4.8 ng m-3. ii) Rural site: GEM=5.0±2.8 ng m-3. Several source regions of atmospheric mercury to the urban and rural sites were determined using Concentration Field Analysis, in which atmospheric mercury measurements were combined with back trajectory data to determine source regions. Only some source regions correlated to mercury emission sources listed in the Federal Pollutant Release and Transfer Register, leaving the rest unaccounted for. Contributions of anthropogenic mercury point sources in and around Mexico City to concentration averages measured at the urban site during the study were estimated to be: 93±3% of reactive mercury (PHg and RGM), and; 81±0.4% of GEM. Point source contributions to GEM measured at the rural site were 72±1%. GEM and reactive mercury (PHg and RGM) were not found to correlate with biomass burning at either of the measurement sites.

  12. Fluxes of deep CO 2 in the volcanic areas of central-southern Italy

    NASA Astrophysics Data System (ADS)

    Gambardella, Barbara; Cardellini, Carlo; Chiodini, Giovanni; Frondini, Francesco; Marini, Luigi; Ottonello, Giulio; Vetuschi Zuccolini, Marino

    2004-08-01

    Both the shallow (organic-derived) and deep (mantellic-magmatic-metamorphic) fluxes of CO 2 [ ΦCO 2, mass time -1] and specific fluxes of CO 2 [ ϕCO 2 mass time -1 surface -1] dissolving in the shallow groundwaters of the volcanic areas of Amiata, Vulsini-Vico-Sabatini, Albani, Roccamonfina, Vesuvio, Vulture, and Etna were evaluated by partitioning the composed population of total dissolved inorganic carbon in two individual populations and subsequent subtraction of local background population. The flux of deep CO 2 released from the geothermal fields of Piancastagnaio (Amiata), Torre Alfina, Latera, Marta, Bracciano south, Cesano, and Mofete and from the Overall Northern Latium Hydrothermal Reservoir were also evaluated by means of the total surface heat flux and the enthalpy and CO 2 molality of the single liquid phase circulating in each geothermal reservoir. These data suggest that the ϕCO 2 released to the atmosphere varies from 9.5×10 6 to 3.0×10 6 mol year -1 km -2, over the geothermal fields of Bracciano south and Cesano, respectively, and that a total ΦCO 2 of 3.8×10 8 mol year -1 is cumulatively released from the geothermal fields of Torre Alfina, Latera and Cesano extending over an area of only 66 km 2. In addition, a flux of ˜2.2×10 11 to 3.8×10 11 mol year -1 of gaseous CO 2 entering the atmosphere is obtained for the entire anomalous area of central Italy, extending from the Tyrrhenian coastline to the Apennine chain (45,000 km 2). Thus terrestrial CO 2 emission in central-southern Italy appears to be a significant carbon source.

  13. HIV Incidence and Spatial Clustering in a Rural Area of Southern Mozambique

    PubMed Central

    González, Raquel; Augusto, Orvalho J.; Munguambe, Khátia; Pierrat, Charlotte; Pedro, Elpidia N.; Sacoor, Charfudin; De Lazzari, Elisa; Aponte, John J.; Macete, Eusébio; Alonso, Pedro L.; Menendez, Clara; Naniche, Denise

    2015-01-01

    Background Monitoring the HIV epidemic in a defined population is critical for planning treatment and preventive strategies. This is especially important in sub-Saharan Africa, which harbours the highest burden of the disease. Objective To estimate HIV incidence in adults aged 18-47 years old and to investigate spatial variations of HIV prevalence in Manhiça, a semi-rural area of southern Mozambique. Methods Two cross-sectional community-based surveys were conducted in 2010 and 2012 to determine HIV prevalence. Individual participants were randomly selected from the demographic surveillance system in place in the area and voluntary HIV counselling and testing was offered at the household level. HIV incidence was calculated using prevalence estimates from the two sero-surveys. Each participant’s household was geocoded using a global information system. The Spatial Scan Statistics programme was used to identify areas with disproportionate excess in HIV prevalence. Results A total of 1511 adults were tested. The estimated HIV prevalence in the community was 39.9% in 2010 and 39.7% in 2012. The overall HIV incidence was 3.6 new infections per 100 person-years at risk (PYAR) [95CI 1.56; 7.88], assuming stable epidemic conditions, and tended to be higher in women (4.9/100 PYAR [95CI 1.74; 11.85]) than in men (3.2/PYAR [95CI 1.36; 9.92]). One cluster with significant excess HIV prevalence was identified at the same geographic location in both surveys. This cluster had an HIV prevalence of 79.0% in 2010 and 52.3% in 2012. Conclusions The findings of these first individually-randomised community-HIV sero-surveys conducted in Mozambique reinforce the need to combine HIV incidence estimates and research on micro geographical infection patterns to guide and consolidate effective prevention strategies. PMID:26147473

  14. 76 FR 22749 - Camden & Southern Railroad, Inc.-Lease and Operation Exemption-Camden Area Industrial Development...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... & Russellville R.R., Ouachita R.R., & Camden & S. R.R., 76 FR 21797-98 (Apr. 18, 2011). The transaction is... Industrial Development Corporation Camden & Southern Railroad, Inc. (C&S), a noncarrier, has filed a verified... Area Industrial Development Corporation (CAIDC), located at Zone JH482, Yard 06, opposite milepost...

  15. 50 CFR Figure 2 to Subpart E of... - Southern Southeast Alaska Rural and Non-Rural Areas

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Southern Southeast Alaska Rural and Non-Rural Areas 2 Figure 2 to Subpart E of Part 300 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS Pacific Halibut Fisheries Pt. 300, Subpt. E, Fig. 2 Figure...

  16. 50 CFR Figure 2 to Subpart E of... - Southern Southeast Alaska Rural and Non-Rural Areas

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Southern Southeast Alaska Rural and Non-Rural Areas 2 Figure 2 to Subpart E of Part 300 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS Pacific Halibut Fisheries Pt. 300, Subpt. E, Fig. 2 Figure...

  17. Distribution and potential significance of a gull fecal marker in urban coastal and riverine areas of southern Ontario, Canada

    EPA Science Inventory

    To better understand the distribution of gull fecal contamination in urban areas of southern Ontario, we used a gull-targeted PCR assay against 1309 water samples collected from 15 urban coastal and riverine locations during 2007. Approximately, 58 % of the water samples tested w...

  18. 50 CFR Figure 1 to Subpart G of... - Boundaries of the Statistical Reporting Area in the Southern Ocean

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Boundaries of the Statistical Reporting Area in the Southern Ocean 1 Figure 1 to Subpart G of Part 300 Wildlife and Fisheries INTERNATIONAL.... 300, Subpt. G, Fig. 1 Figure 1 to Subpart G of Part 300—Boundaries of the Statistical Reporting...

  19. 50 CFR Figure 1 to Subpart G of... - Boundaries of the Statistical Reporting Area in the Southern Ocean

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Boundaries of the Statistical Reporting Area in the Southern Ocean 1 Figure 1 to Subpart G of Part 300 Wildlife and Fisheries INTERNATIONAL.... 300, Subpt. G, Fig. 1 Figure 1 to Subpart G of Part 300—Boundaries of the Statistical Reporting...

  20. Capture Zone Analyses of Two Airlift Recirculation Wells in the Southern Sector of A/M Area

    SciTech Connect

    Aleman, S.E.

    1999-09-14

    This report documents a series of capture zone analyses performed to access the expected overall performance of two (of the twelve) vertical airlift recirculation wells (ARWs) (specifically, SSR-011 and SRR-012) located in the Southern Sector of A/M Area.

  1. Assessment of the sustainability of dual-purpose farms by the IDEA method in the subtropical area of central Mexico.

    PubMed

    Salas-Reyes, Isela Guadalupe; Arriaga-Jordán, Carlos Manuel; Rebollar-Rebollar, Samuel; García-Martínez, Anastacio; Albarrán-Portillo, Benito

    2015-08-01

    The objective of this study was to assess the sustainability of 10 dual-purpose cattle farms in a subtropical area of central Mexico. The IDEA method (Indicateurs de Durabilité des Exploitations Agricoles) was applied, which includes the agroecological, socio-territorial and economic scales (scores from 0 to 100 points per scale). A sample of 47 farms from a total of 91 registered in the local livestock growers association was analysed with principal component analysis and cluster analysis. From results, 10 farms were selected for the in-depth study herein reported, being the selection criterion continuous milk production throughout the year. Farms had a score of 88 and 86 points for the agroecological scale in the rainy and dry seasons. In the socio-territorial scale, scores were 73 points for both seasons, being the component of employment and services the strongest. Scores for the economic scale were 64 and 56 points for the rainy and dry seasons, respectively, when no economic cost for family labour is charged, which decreases to 59 and 45 points when an opportunity cost for family labour is considered. Dual-purpose farms in the subtropical area of central Mexico have a medium sustainability, with the economic scale being the limiting factor, and an area of opportunity. PMID:25958175

  2. Current conceptual model of groundwater flow and contaminant transport at Sandia National Laboratories/New Mexico Technical Area V.

    SciTech Connect

    Orr, Brennon R.; Dettmers, Dana L.

    2004-04-01

    The New Mexico Environment Department (NMED) requires a Corrective Measures Evaluation to evaluate potential remedial alternatives for contaminants of concern (COCs) in groundwater at Sandia National Laboratories New Mexico (SNUNM) Technical Area (TA)-V. These COCs consist of trichloroethene, tetrachloroethene, and nitrate. This document presents the current conceptual model of groundwater flow and transport at TA-V that will provide the basis for a technically defensible evaluation. Characterization is defined by nine requirement areas that were identified in the NMED Compliance Order on Consent. These characterization requirement areas consist of geohydrologic characteristics that control the subsurface distribution and transport of contaminants. This conceptual model document summarizes the regional geohydrologic setting of SNUNM TA-V. The document also presents a summary of site-specific geohydrologic data and integrates these data into the current conceptual model of flow and contaminant transport. This summary includes characterization of the local geologic framework; characterization of hydrologic conditions at TA-V, including recharge, hydraulics of vadose-zone and aquifer flow, and the aquifer field of flow as it pertains to downgradient receptors. The summary also discusses characterization of contaminant transport in the subsurface, including discussion about source term inventory, release, and contaminant distribution and transport in the vadose zone and aquifer.

  3. Early Mesozoic reconstructions, tectonics and paleogeography of Caribbean-Gulf of Mexico-Atlantic area

    SciTech Connect

    Wiener, R.W.; Norton, I.O.

    1985-01-01

    Five plate reconstructions with paleogeography show the evolution of the Gulf of Mexico-Caribbean-Atlantic from Late Triassic through Late Jurassic time. The reconstructions are constrained by oceanic geophysical data, by the distribution of Paleozoic tectonic belts and early Mesozoic sedimentary and igneous rocks, and by restoration of post-Jurassic faulting. Late Triassic rifting formed grabens in which continental sediments and tholeiitic volcanics accumulated. Overlying salt was deposited from ingression of Tethyan waters into circum-Atlantic grabens. Oceanic crust formed in the Atlantic about 165 m.y. ago, followed by a spreading-center jump about 160 m.y. ago. The NA/SA-Africa plate boundary was a zone of intracontinental faulting from the left-lateral Bahama fracture zone to a zone of normal and strike-slip faulting in the Gulf, to the left-lateral Mojave-Sonora megashear. Sea-floor spread in began in the proto-Caribbean in the middle Jurassic, while only rifting occurred in the Gulf of Mexico, where the Louann salt was deposited from Pacific waters. In the late Jurassic, steepening of the Pacific subduction zone resulted ion back-arc extension in Mexico. At the same time, sea-floor spreading began in the Gulf of Mexico, resulting in marine transgression. In the late Oxfordian, spreading center reorganization occurred in the Gulf. Movement ceased on the Mojave-Sonora megashear and began on the Salina Cruz right-lateral fault. In latest Jurassic spreading ceased in the Gulf, but continued in the proto-Caribbean.

  4. Metamorphism and gold mineralization of the Kenticha Katawicha area: Adola belt, southern Ethiopia

    NASA Astrophysics Data System (ADS)

    Tsige, Lulu

    2006-05-01

    I present geological and mineral chemistry results aiming at understanding the relationship between metamorphism and gold mineralization in the N-trending Neoproterozoic Kenticha-Katawicha area in the Adola belt of southern Ethiopia. The Kenticha-Katawicha area comprises low-grade metamorphic rocks including pelitic schists, marble, graphite schists and Fe-Mn quartzites (Kenticha marine metasedimentary rocks) and serpentinites and talc-tremolite-chlorite schists with podiform chromites (Kenticha ophiolite). Lenses of high-grade amphibolite schist are also locally present within the Kenticha-Katawicha area. These rocks are sandwiched between high-grade para- and ortho-gneisses, migmatites, schists and amphibolites. Post-orogenic granites intrude the metamorphic sequences. Mineral assemblages and textural data obtained from the high-grade rocks indicate that the dominant metamorphic condition is of upper amphibolite facies. Garnet-biotite (garnet-core-matrix-biotite) and amphibole-plagioclase geothermometry gave estimates for peak metamorphic temperatures of 630-650 °C and pressure of 7 kbar for the high-grade rocks. On the other hand, the low-grade rocks recrystallized in the greenschist facies conditions. The estimated peak T- P values for the high-grade rocks suggest a burial to ˜25 km depth and a clockwise P- T path is deduced from mineral thermometry and the textural and paragenetic relations. This combined with the geochemistry of the magmatic rocks and clockwise P- T is consistent with a collision setting in which rocks of the calc-alkaline, volcanic-arc, and oceanic fragments are assembled. In the study area, gold occurs in quartz veins and veinlets in lenses of biotite schists within ultramafic rocks that are confined to shear zones. Fluid inclusion studies of gold quartz veins and veinlets indicate a H 2O- and CO 2-rich fluid with low salinity (<5 wt% NaCl equivalent). The gold mineralization in the area is post-peak regional metamorphism and is

  5. Relation between Oceanographic parameters and Optical properties in 5 coastal areas of Southern Italy

    NASA Astrophysics Data System (ADS)

    Campanelli, Alessandra; Braga, Federica; Betti, Mattia; Cavalli, Rosa Maria; Grilli, Federica; Pascucci, Simone; Marini, Mauro

    2014-05-01

    In the framework of the CLAM-PHYM (Coasts-and-Lake-Assessment-and-Monitoring-by-Prisma-Hyperspectral-Mission) project it was carried out an oceanographic cruise (27/08-13/09/2010) along the coasts of southern Italy in order to analyze the physical, biochemical and optical properties of some coastal areas. The sampling areas are: the Gulf of Taranto, the Policoro area, the Cetraro Bay, the Gulf of Augusta and the Gulf of Gela. CTD profiles and reflectance measurements of the sea surface and along the water column with portable field spectroradiometers were collected. Water samples were also collected for the analysis of nutrients, chlorophyll-a and CDOM. These optically active substances interact with solar radiation along the water column through absorption and scattering phenomena. The collected data were analyzed to identify the relationship between the bio-optical concentrations of optically-active-substances and the surface reflectance spectra measured in situ; this relation, if reversed, can be used to map the concentrations of optically-active-substances from hyperspectral-satellite-data. Results stress high biological activity in the Gulf of Taranto and in the Gulf of Gela showing the highest values of chlorophyll-a and aCDOM440. These areas are characterized by the presence of important industrial and port sites. The Gela's gulf, where we found the highest concentrations of chlorophyll a and CDOM, is also characterized by the runoff of the Salso river increasing the biological activity. The correlations found in the Gulf of Taranto between Kd, chlorophyll a and aCDOM440 indicate that the high concentrations of CDOM are primarily due to phytoplankton rather than from terrestrial source. The Gulf of Taranto shows the best site among those investigated where to identify bio-optical relationships between the concentrations of optically active substances and the surface reflectance spectra measured in situ. The preliminary results encourage the combined use of

  6. An oilspill risk analysis for the eastern Gulf of Mexico (proposed sale 65) Outer Continental Shelf lease area

    USGS Publications Warehouse

    Wyant, Timothy; Slack, James R.

    1978-01-01

    An oilspill risk analysis was conducted to determine the relative environmental hazards of developing oil in different regions of the Eastern Gulf of Mexico Outer Continental Shelf lease area. The study analyzed the probability of spill occurrence, likely paths of the spills, and locations in space and time of such objects as recreational and biological resources likely to be vulnerable. These results combined to yield estimates of the overall oilspill risk associated with development of the proposed lease area. This risk is compared to the existing oilspill risk from existing leases in the area. The analysis implicitly includes estimates of weathering rates and slick dispersion and an indication of the possible mitigating effects of cleanups.

  7. Sandfly (Diptera: Psychodidae: Phlebotominae) species diversity in an urban area of the municipality of Tapachula, Chiapas, Mexico

    PubMed Central

    Pacheco, Oscar Fernando Mikery; León, Julio Cesar Rojas; Rebollar-Téllez, Eduardo Alfonso; Vera, Alfredo Castillo

    2015-01-01

    Monitoring phlebotomine sandflies in urban areas is key for epidemiological studies in susceptible populations. This paper describes sandfly fauna that were present in an urban area of the municipality of Tapachula, Chiapas, Mexico, and were captured with Shannon and CDC light traps. During February and March of 2014, 1,442 sandflies were captured, specifically Lutzomyia cruciata (Coquillet) (98.8%), Lutzomyia cayennensis cayennensis (Floch and Abonnenc) (0.8%), Lutzomyia chiapanensis (Dampf) (0.3%) and Lutzomyia atulapai (De León) (0.1%). Lu. cruciata was the most abundant and the most frequently trapped species. This is the first record of its remarkable ability to adapt to urban green areas. The three other species trapped represent new records of geographic distribution for the study region. These results indicate the need to establish measures for reducing both human contact with this vector and the risk of possible sites of infection. PMID:25742275

  8. Using Landsat 5 TM Data to Identify and Map Areas of Mangrove in Tulum, Quintana Roo, Mexico

    NASA Astrophysics Data System (ADS)

    Meachum, Samuel Standish

    Mangroves are recognized worldwide as a major ecosystem that provides significant ecosystem services. They are threatened due to rising pressures from human overpopulation and economic development. The Caribbean Coast of Mexico's Yucatan Peninsula contains mangrove habitat that have been negatively impacted by the development of the region's tourist industry. However, little research has been done to map and quantify the extent of mangrove in the region. This study used remote sensing techniques to identify mangrove in the Municipality of Tulum located in Quintana Roo, and to produce an accurate vector based thematic map that inventories these areas. Anatomical differences were analyzed and related to high-resolution field spectral data for each mangrove species. A vector map of mangrove habitat, including areas of inland mangrove, was produced with an overall accuracy of 88%. The 19,262 ha. of mangrove identified by this study represents a 140% increase in area over previous studies.

  9. Acceptability of Hypothetical Microbicides among Women in Sex Establishments in Rural Areas in Southern China

    PubMed Central

    Wang, Yu; Liao, Su-Su; Weeks, Margaret R.; Jiang, Jing-Mei; Abbott, Maryann; Zhou, Yue-Jiao; He, Bin; Liu, Wei; Mosack, Katie E.

    2010-01-01

    Objectives and Goal The objectives of this study were to measure the potential acceptability of a hypothetical microbicide among women in sex establishments in rural areas of Southern China, and demographic, behavioral and social context factors likely to affect microbicide acceptability. Study Design This was a cross-sectional survey, using a quota sampling, among 300 women from sex establishments in three rural towns. An interviewer-administered standardized questionnaire was used to measure the acceptability score of hypothetical microbicides’ characteristics, as well as sexual relationships and behaviors, and other contextual factors. Results Findings showed a generally positive response to microbicides, indicated by an acceptability index score of 2.89 (SD, 0.56, scale of 1–4) in the overall sample. Multivariate analysis shows the acceptability score varied significantly by study sites, type of sex-work establishments, marital status, sex partner type, vaginal product experience, locus of control by partners and locus of control by chance. Conclusions Microbicides may be acceptable among sex workers in rural settings in China; however, contextual factors should be carefully considered in education and promotion of microbicides in the future. PMID:17767093

  10. An experimental study of a minette from the Milk River area, southern Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Funk, Sean P.; Luth, Robert W.

    2012-12-01

    Buhlmann et al. (Can J Earth Sci 37: 1629-1650, 2000) studied the minettes and xenoliths from the Milk River area of southern Alberta, Canada. Based on previous work, they hypothesized that the minettes were derived from a source containing phlogopite + clinopyroxene ± olivine, at pressures ≥1.7 GPa. To test this hypothesis, liquidus experiments were performed on a primitive minette between 1.33 and 2.21 GPa and between 1,300 and 1,400 °C to constrain the mineralogy of its source region. We found a multiple saturation point along the liquidus at 1.77 GPa and 1,350 °C, where the liquid coexists with orthopyroxene and olivine. Neither phlogopite nor clinopyroxene were found to be liquidus phases, which is inconsistent with Buhlmann et al.'s hypothesis. We suggest that our minette is not primary, but had re-equilibrated with harzburgitic mantle subsequent to formation. In such a scenario, partial melting of a veined source containing mica and clinopyroxene occurred at or near the base of the Wyoming craton (~200 km). Minimal heating or the introduction of hydrous fluids into the source would be required to induce partial melting. Rapid ascent rates, coupled with slow cooling rates, of the "primary minette magma" would preserve the high temperature observed in our experiments. At ~58 km, our "primary minette magma" likely stalled and re-equilibrated with the harzburgite surroundings.

  11. Deforestation and Forest Management in Southern Ethiopia: Investigations in the Chencha and Arbaminch Areas

    NASA Astrophysics Data System (ADS)

    Assefa, Engdawork; Bork, Hans-Rudolf

    2014-02-01

    Long-term human impacts are considered to be the prime cause of unsustainable forest exploitation in Ethiopia. Yet there exist well-established systems and a wealth of local experience in maintaining and managing forests. This study explores the trends and driving forces of deforestation plus traditional practices regarding sustainable forest use and management in the Chencha and Arbaminch areas, Southern Ethiopia. Satellite image analysis (images from 1972, 1984 and 2006) combined with field surveys were used to detect and map changes in forest cover. Household interviews and group discussions with experienced and knowledgeable persons were also employed. The results show a 23 % decline in forest cover between 1972 and 2006 with the most significant change from 1986 to 2006. Change was greatest in the lowlands and remarkable episodic forest changes also occurred, suggesting nonlinear spatial and temporal forest cover dynamics. According to farmers, the main driver of deforestation is agricultural land expansion in response to local population increases and a decline in agricultural production. Growing local and regional fuel wood demand is another chief cause. Despite these issues, remarkable relicts of natural forests remain and trees on farmland, around homesteads and on fields in every village are basic elements of farm activities and social systems. This demonstrates the effect of cumulative traditional knowledge and long-term local experience with forest management and preservation. Therefore, these practices should be promoted and advanced through the integration of local knowledge and forest management practices in the design and implementation of sustainable environmental planning and management.

  12. Performance assessment of separate and combined sewer systems in metropolitan areas in Southern China.

    PubMed

    Li, Tian; Zhang, Wei; Feng, Cang; Shen, Jun

    2014-01-01

    To assess the performance of urban drainage systems in metropolitan areas in southern China, 12 urban drainage systems, including nine separate sewer systems (SSSs) and three combined sewer systems (CSSs) were monitored from 2008 to 2012 in Shanghai and Hefei. Illicit connection rates of SSS were determined. The results indicate that serious illicit connections exist for most SSSs. Annual volume balance for two SSSs with serious illicit connection was assessed with a hydraulic model to determine the dry weather overflow volume. Although interception facilities have been implemented in SSSs, for some systems with serious illicit connections, a considerable volume of dry weather overflow still existed. Combined with monitoring of dry/wet weather flow quality, the pollutant load caused by wet/dry weather overflow was quantified. The results revealed that there was no obvious advantage of having SSSs over CSSs in terms of pollutant control. The serious pollution caused by illicit connections and insufficient management occurs in many cities in China. The performance assessment of separate and CSSs in Shanghai and Hefei provides important lessons and practical experience that can be applied to the construction and management of urban drainage system in China as well as other developing countries. PMID:24473315

  13. Assessment of anthropogenic inputs in the surface waters of the southern coastal area of Sfax during spring (Tunisia, Southern Mediterranean Sea).

    PubMed

    Drira, Zaher; Kmiha-Megdiche, Salma; Sahnoun, Houda; Hammami, Ahmed; Allouche, Noureddine; Tedetti, Marc; Ayadi, Habib

    2016-03-15

    The coastal marine area of Sfax (Tunisia), which is well-known for its high productivity and fisheries, is also subjected to anthropogenic inputs from diverse industrial, urban and agriculture activities. We investigated the spatial distribution of physical, chemical and biogeochemical parameters in the surface waters of the southern coastal area of Sfax. Pertinent tracers of anthropogenic inputs were identified. Twenty stations were sampled during March 2013 in the vicinity of the coastal areas reserved for waste discharge. Phosphogypsum wastes dumped close to the beaches were the main source of PO4(3-), Cl(-) and SO4(2-) in seawater. The high content in total polyphenolic compounds was due to the olive oil treatment waste water released from margins. These inorganic and organic inputs in the surface waters were associated with elevated COD. The BOD5/COD (<0.5) and COD/BOD5 (>3) ratios highlighted a chemical pollution with organic load of a low biodegradability. PMID:26837269

  14. [Habitat use of Williamson's Mouse-deer (Tragulus williamsoni) in Mengla area, southern Yunnan].

    PubMed

    Cao, Ming; Zhou, Wei; Bai, Bing; Zhang, Qin; Wang, Bin; Chen, Min-Yong

    2010-06-01

    Combining line-transect method and sampling method, the geographic coordinates of footprint links for Williamson's Mouse-deer (Tragulus williamsoni) were collected in Mengman and Longmen regions of Mengla area, southern Yunnan, from June to December 2007. A distribution pattern map of the mouse-deer was produced by GIS software. Eleven ecological factors were measured in collected and available samples. The results indicated that the mouse-deer preferred valleys along banks of rivers or streams in low altitude, and were mainly distributed in Sanchahe of Mengman region and Darongshu of Longmen region. Comparing nominal factors between collected and available samples, the results showed that the mouse-deer tended to inhabit middle and lower slopes and favored the plant species of Ficus hirtal, Baccaurea samiflora, Alpinia kwangsiensis and Phrynium capitatum. These plants occur along banks of rivers or streams, one of the important reasons affecting distribution of the mouse-deer populations. Comparing quantitative factors between collected and available samples, the results showed that four factors including tall tree coverage, shrub coverage and herb coverage, and distance to water, were significantly different. These four factors were key in discriminating collected and available samples and main factors affecting the habitat use of the mouse-deer. The dense shrub with taller trees could form good shady condition for the mouse-deer, and greatly strengthen their security. Due to their preference for areas near water, there were more flourishing tall trees and dense shrubs at valleys in low altitude, which was one of important reasons affecting the distribution of the mouse-deer populations massing in valleys in low altitude. PMID:20672420

  15. 3D Strucutural Geological Model of the Alpi Mt. Area (Southern Italy)

    NASA Astrophysics Data System (ADS)

    La Bruna, Vincenzo; Lamarche, Juliette; Viseur, Sophie; Agosta, Fabrizio; Prosser, Giacomo

    2016-04-01

    The study area is located in the inner portion of the southern Apennines fold-and-thrust belt. The Alpi Mt. is the only portion of the Apulian domain cropping in this sector. In fact, it is considered as a structural analogue of the Val d'Agri and Tempa Rossa reservoirs (Basilicata). The Alpi Mt. tectonic unit is composed of two main cronostratigraphic intervals, represented by a 2000m-thick Mesozoic carbonate succession and a Messinian mixed carbonate-terrigenous succession. The Messinian interval is made up of a Lower Messinian sedimentary cycle, wich form a paraconformity with the underlying Mesozoic carbonates, and an Upper Messinian cycle characterized by a marked unconformity at the bottom. This study aims to better understand the role exerted by the precontractional tectonic structures during the Messinian interval, wich are responsible for the development of the sedimentary angular unconformity. To reach this goal, a 3D structural geological model was build up by using the Gocad(R) software. The construction of the 3D model was gained through the integration of several results related to geological field mapping, well log analysis and seismic reflection data. Focusing on the Upper Messinian sedimentary horizon, in order to achieve the true geometry and kinematics of the high-angle extensional faults that bound the sedimentary depocenters, the model was restored through vertical line methodology. This process allows to obtain more information about location, geometry, and sedimentary depocenter orientations. Furthermore, the 3D structural model brings some important results from the 3D fault analysis that are represented by attitude, geometry and dimensional parameters of the fault network that affect the study area.

  16. Detailed seismicity analysis revealing the dynamics of the southern Dead Sea area

    NASA Astrophysics Data System (ADS)

    Braeuer, B.; Asch, G.; Hofstetter, R.; Haberland, Ch.; Jaser, D.; El-Kelani, R.; Weber, M.

    2014-10-01

    Within the framework of the international DESIRE (DEad Sea Integrated REsearch) project, a dense temporary local seismological network was operated in the southern Dead Sea area. During 18 recording months, 648 events were detected. Based on an already published tomography study clustering, focal mechanisms, statistics and the distribution of the microseismicity in relation to the velocity models from the tomography are analysed. The determined b value of 0.74 leads to a relatively high risk of large earthquakes compared to the moderate microseismic activity. The distribution of the seismicity indicates an asymmetric basin with a vertical strike-slip fault forming the eastern boundary of the basin, and an inclined western boundary, made up of strike-slip and normal faults. Furthermore, significant differences between the area north and south of the Bokek fault were observed. South of the Bokek fault, the western boundary is inactive while the entire seismicity occurs on the eastern boundary and below the basin-fill sediments. The largest events occurred here, and their focal mechanisms represent the northwards transform motion of the Arabian plate along the Dead Sea Transform. The vertical extension of the spatial and temporal cluster from February 2007 is interpreted as being related to the locking of the region around the Bokek fault. North of the Bokek fault similar seismic activity occurs on both boundaries most notably within the basin-fill sediments, displaying mainly small events with strike-slip mechanism and normal faulting in EW direction. Therefore, we suggest that the Bokek fault forms the border between the single transform fault and the pull-apart basin with two active border faults.

  17. [Effect of environmental factors and fishing effort allocation on catch of the Spotted Eagle Ray Aetobatus narinari (Rajiformes: Myliobatidae) in Southern Gulf of Mexico].

    PubMed

    Cuevas, Elizabeth; Pérez, Juan Carlos; Méndez, Iván

    2013-09-01

    Aetobatus narinari represents a fisheries target in Southern Gulf of Mexico, and it is currently considered a Near Threatened species by the IUCN red list. The information available of this batoid fish includes some biological and fishery aspects; nevertheless, little is known about the factors influencing on fishing operations and catches. In order to evaluate the effect of environmental factors and the fishing effort allocation by vessels on the target fishery of A. narinari in this area, a daily basis sampling was carried out on four small-scale vessels, from January to July 2009 (the entire fishing season), in two fishing localities (Campeche and Seybaplaya). A total of 896 rays were recorded from 280 fishing trips. A General Linear Model was used to predict the factors effect on the probability that fishing operations occurred, and on the probability for captures of at least one or three or five rays per vessel-trip. The probability that fishing operations occurred off Campeche was predicted by the lunar cycle, with the highest probability in the new moon period (66%) and a probability smaller than 35% for the other periods. The probability that fishing operations occurred off Seybaplaya was predicted by wind velocity, with higher probabilities at low wind velocity than at high wind velocity, and a 50% probability of fishing operations at 12-15 km/h. Catch rates off Seybaplaya were predicted by the vessel's factor (the effect of fishing effort allocation), the North wind season and sea surface temperature. The probability for captures of at least one and three rays per vessel-trip was predicted by the vessel's factor and the North wind season. One vessel had higher catch probability (83% for at least one ray and 43% for at least three rays) than the others (69 and 70% for at least one ray and 26% for at least three rays), and during the North wind season the catch probability was higher (96% for at least one ray and 72% for at least three rays) than out of

  18. Factors associated with the prevalence of Perkinsus marinus in Crassostrea virginica from the southern Gulf of Mexico.

    PubMed

    Gullian-Klanian, M; Herrera-Silveira, J A; Rodríguez-Canul, R; Aguirre-Macedo, L

    2008-05-01

    The protozoan Perkinsus marinus is considered the most important pathogen of the eastern oyster Crassostrea virginica, causing high mortality in natural and farmed oysters on the Atlantic coast of the US. In Mexico, no serious P. marinus epizootic has been reported. This study describes the current state of P. marinus prevalence in Terminos Lagoon (Mexico) associated with environmental factors including salinity, temperature, ammonium, nitrate, nitrite, silica, and phosphorus. In addition, the association of physiological (hemocyte density, protein concentration) and immunological (lysozyme, agglutination) parameters with the infection were studied. The prevalence was significantly different among seasons with mean values of 70, 23, and 7% in the dry (February to May), rainy (June to September) and north-wind (October to January) seasons, respectively. Only light infection intensity (Mackin scale value < 1) was observed. Prevalence of P. marinus was associated with seasonal salinity, phosphorus, and silica variations. Comparisons of oyster health demonstrates that the rainy and north-wind seasons are stressful periods. Redundancy analysis showed that only 34% of the variation in seasonal P. marinus prevalence was explained by protein concentration (21%), lysozyme (12%), and agglutination (1%). Overall, the data suggest that freshwater input associated with high nutrient concentrations during the rainy and north-wind seasons has a strong negative effect on P. marinus prevalence and also influences the oysters' physiology. It is probable that this seasonal stress was responsible for the absence of an epizootic event in Terminos Lagoon. PMID:18590000

  19. Final report for "Characterization of Fine Particulate Matter (PM) and secondary PM Precursor Gases in the Mexico City Metropolitan Area"

    SciTech Connect

    Prof. Jose-Luis Jimenez

    2009-05-18

    The objectives of this funded project were (a) to further analyze the data collected by our group and collaborators in Mexico City during the MCMA-2003 field campaign, with the goal of further our understanding of aerosol sources and processes; and (b) to deploy several advanced instruments, including the newly developed high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and thermal-denuder (TD), during the MILAGRO/MAX-Mex/MCMA-2006 field campaign, and to analyze those data (together with the 2003 data) to provide additional insights on the formation and transformation of aerosols in the Mexico City area. These goals were addressed in collaboration with our project partners, MIT/Molina Center, and Aerodyne Research. Overall this project was very successful, resulting on 22+ journal papers including six “highly cited papers” and three papers that are the most cited in their respective journals (out of several thousand papers) since the year in which they were published. Multiple discoveries, such as the the underestimation of SOA in urban areas even for short photochemical ages, the demonstration that urban POA is of similar or higher volatility than urban SOA, and the first analysis of organic aerosol elemental composition in real-time have been recently published. Several dozen presentations at major US and international conferences and seminars also acknowledged this grant.

  20. Spring land temperature anomalies in northwestern US and the summer drought over Southern Plains and adjacent areas

    NASA Astrophysics Data System (ADS)

    Xue, Yongkang; Oaida, Catalina M.; Diallo, Ismaila; Neelin, J. David; Li, Suosuo; De Sales, Fernando; Gu, Yu; Robinson, David A.; Vasic, Ratko; Yi, Lan

    2016-04-01

    Recurrent drought and associated heatwave episodes are important features of the US climate. Many studies have examined the connection between ocean surface temperature changes and conterminous US droughts. However, remote effects of large-scale land surface temperature variability, over shorter but still considerable distances, on US regional droughts have been largely ignored. The present study combines two types of evidence to address these effects: climate observations and model simulations. Our analysis of observational data shows that springtime land temperature in northwest US is significantly correlated with summer rainfall and surface temperature changes in the US Southern Plains and its adjacent areas. Our model simulations of the 2011 Southern Plains drought using a general circulation model and a regional climate model confirm the observed relationship between land temperature anomaly and drought, and suggest that the long-distance effect of land temperature changes in the northwest US on Southern Plains droughts is probably as large as the more familiar effects of ocean surface temperatures and atmospheric internal variability. We conclude that the cool 2011 springtime climate conditions in the northwest US increased the probability of summer drought and abnormal heat in the Southern Plains. The present study suggests a strong potential for more skillful intra-seasonal predictions of US Southern Plains droughts when such facts as ones presented here are considered.