Science.gov

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. 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

  16. 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) ...

  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. 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.

  20. 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

  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. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

  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. 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.

  12. 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.

  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. 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.

  16. 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.

  17. 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

  18. 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...

  19. 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...

  20. 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...

  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. 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.

  8. 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...

  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 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

  12. 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

  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. 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,...

  4. 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…

  5. 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…

  6. 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…

  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. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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...

  15. 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.

  16. 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.

  17. 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

  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. 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.

  5. 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...

  6. 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...

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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.

  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. 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

  6. 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.

  7. 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

  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. 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.

  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. 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

  18. 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

  19. 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

  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. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  6. [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

  7. 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

  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. 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)

  13. 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

  14. 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

  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. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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.

  2. 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

  3. 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

  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. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  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. 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

  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. 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…

  3. 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 ...

  4. 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...

  5. 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...

  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. 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

  16. 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...

  17. 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...

  18. 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

  19. 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.

  20. 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

  1. 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

  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. 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.

  10. [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