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Sample records for cruz river patagonia

  1. Santa Cruz River Options

    EPA Science Inventory

    This presentation summarizes qualitative research insights gained during development of a nonmarket valuation survey for changes to the Santa Cruz River in Southern Arizona. Qualitative research provides an important avenue for understanding how the public interprets valuation s...

  2. Streamflow in the upper Santa Cruz River basin, Santa Cruz and Pima Counties, Arizona

    USGS Publications Warehouse

    Condes de la Torre, Alberto

    1970-01-01

    Streamflow records obtained in the upper Santa Cruz River basin of southern Arizona, United States, and northern Sonora, Mexico, have been analyzed to aid in the appraisal of the surface-water resources of the area. Records are available for 15 sites, and the length of record ranges from 60 years for the gaging station on the Santa .Cruz River at Tucson to 6 years for Pantano Wash near Vail. The analysis provides information on flow duration, low-flow frequency magnitude, flood-volume frequency and magnitude, and storage requirements to maintain selected draft rates. Flood-peak information collected from the gaging stations has been projected on a regional basis from which estimates of flood magnitude and frequency may be made for any site in the basin. Most streams in the 3,503-square-mile basin are ephemeral. Ground water sustains low flows only at Santa Cruz River near Nogales, Sonoita Creek near Patagonia, and Pantano Wash near Vail. Elsewhere, flow occurs only in direct response to precipitation. The median number of days per year in which there is no flow ranges from 4 at Sonoita Creek near Patagonia to 335 at Rillito Creek near Tomson. The streamflow is extremely variable from year to year, and annual flows have a coefficient of variation close to or exceeding unity at most stations. Although the amount of flow in the basin is small most of the time, the area is subject to floods. Most floods result from high-intensity precipitation caused by thunderstorms during the period ,July to September. Occasionally, when snowfall at the lower altitudes is followed by rain, winter floods produce large volumes of flow.

  3. Geologic map of the Patagonia Mountains, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Graybeal, Frederick T.; Moyer, Lorre A.; Vikre, Peter; Dunlap, Pamela; Wallis, John C.

    2015-01-01

    Several spatial databases provide data for the geologic map of the Patagonia Mountains in Arizona. The data can be viewed and queried in ArcGIS 10, a geographic information system; a geologic map is also available in PDF format. All products are available online only.

  4. USEPA Santa Cruz River Public Survey Research

    EPA Science Inventory

    The USEPA Office of Research and Development, Western Ecology Division is investigating how urban households value different possibilities for the Santa Cruz River in southern Arizona. A random sample of households in the Phoenix and Tucson areas are being asked to provide their ...

  5. Public Values Related to the Santa Cruz River

    EPA Science Inventory

    The Santa Cruz Basin is a focus geography for EPA Southwestern ecosystem services research, and the focal resource is water. The goal of one component of the Santa Cruz effort is to characterize the ways in which basin residents value the river, and environmental resources relate...

  6. Priority River Metrics for Urban Residents of the Santa Cruz River Watershed

    EPA Science Inventory

    Indicator selection is a persistent question in river and stream assessment and management. We employ qualitative research techniques to identify features of rivers and streams important to urban residents recruited from the general public in the Santa Cruz watershed. Interviews ...

  7. Processing and interpretation of aeromagnetic data for the Santa Cruz Basin - Patagonia Mountains area, south-central Arizona

    USGS Publications Warehouse

    Phillips, Jeffrey D.

    2002-01-01

    In 1997, the U.S. Geological Survey (USGS) contracted with Sial Geosciences Inc. for a detailed aeromagnetic survey of the Santa Cruz basin and Patagonia Mountains area of south-central Arizona. The contractor's Operational Report is included as an Appendix in this report. This section describes the data processing performed by the USGS on the digital aeromagnetic data received from the contractor. This processing was required in order to remove flight line noise, estimate the depths to the magnetic sources, and estimate the locations of the magnetic contacts. Three methods were used for estimating source depths and contact locations: the horizontal gradient method, the analytic signal method, and the local wavenumber method. The depth estimates resulting from each method are compared, and the contact locations are combined into an interpretative map showing the dip direction for some contacts.

  8. U-Pb geochronology of the Santa Cruz Formation (early Miocene) at the Río Bote and Río Santa Cruz (southernmost Patagonia, Argentina): Implications for the correlation of fossil vertebrate localities

    NASA Astrophysics Data System (ADS)

    Cuitiño, José I.; Fernicola, Juan Carlos; Kohn, Matthew J.; Trayler, Robin; Naipauer, Maximiliano; Bargo, M. Susana; Kay, Richard F.; Vizcaíno, Sergio F.

    2016-10-01

    The early Miocene Santa Cruz Formation (SCF) in southern Patagonia hosts the Santacrucian South American Land Mammal Age (SALMA), whose age is known mainly from exposures along the Atlantic coast. Zircon U-Pb ages were obtained from intercalated tuffs from four inland sections of the SCF: 17.36 ± 0.63 Ma for the westernmost Río Bote locality, and 17.04 ± 0.55 Ma-16.32 ± 0.62 Ma for central Río Santa Cruz localities. All ages agree with the bounding age of underlying marine units and with equivalent strata in coastal exposures. New ages and available sedimentation rates imply time spans for each section of ∼18.2 to 17.36 Ma for Río Bote and 17.45-15.63 Ma for central Río Santa Cruz (Burdigalian). These estimates support the view that deposition of the SCF began at western localities ∼1 Ma earlier than at eastern localities, and that the central Río Santa Cruz localities expose the youngest SCF in southern Santa Cruz Province. Associated vertebrate faunas are consistent with our geochronologic synthesis, showing older (Notohippidian) taxa in western localities and younger (Santacrucian) taxa in central localities. The Notohippidian fauna (19.0-18.0 Ma) of the western localities is synchronous with Pinturan faunas (19.0-18.0 Ma), but older than Santacrucian faunas of the Río Santa Cruz (17.2-15.6 Ma) and coastal localities (18.0-16.2 Ma). The Santacrucian faunas of the central Río Santa Cruz localities temporally overlap Colloncuran (15.7 Ma), Friasian (16.5 Ma), and eastern Santacrucian faunas.

  9. Tucson's Santa Cruz River and the Arroyo Legacy

    NASA Astrophysics Data System (ADS)

    Betancourt, Julio Luis

    1990-01-01

    Between 1865 and 1915, arroyos developed in the southwestern United States across diverse hydrological, ecological and cultural settings. That they developed simultaneously has encouraged the search for a common cause --some phenomenon that was equally widespread and synchronous. There are few southwestern streams for which we have even a qualitative understanding of timelines and processes involved in initiation and extension of historic arroyos. Tucson's Santa Cruz River, often cited in the arroyo literature, offers a unique opportunity to chronicle the arroyo legacy and evaluate its causes. The present study reconstructs both the physical and cultural circumstances of channel entrenchment along the Santa Cruz River. Primary data include newspaper accounts, notes and plants of General Land Office surveys, eyewitness accounts, legal depositions, and repeat photography. On the Santa Cruz River, arroyo initiation and extension happened during relatively wet decades associated with frequent warm episodes in the tropical Pacific (El Nino conditions). Intensified El Nino activity during the period 1864-1891 may be symptomatic of long-term climatic change, perhaps indicative of global warming and destabilization of Pacific climate at the end of the Little Ice Age. During this period all but one of the years registering more than three days with rain exceeding 2.54 cm (1 in) in Tucson were El Nino events. The one exception was the summer of 1890, when the central equatorial Pacific was relatively cold but when prevailing low-surface pressures and low -level winds nevertheless steered tropical moisture from the west coast of Mexico into southern Arizona. In the twentieth century, catastrophic channel widening was caused by floods during El Nino events in 1905, 1915, 1977 and 1983. The Santa Cruz River arroyo formed when climatic conditions heightened the probabilities for occurrence of large floods in southern Arizona. Inadequate engineering of ditches that resulted in

  10. Regional geochemical studies in the Patagonia Mountains, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Chaffee, M.A.; Hill, R.H.; Sutley, S.J.; Watterson, J.R.

    1981-01-01

    The Patagonia Mountains in southern Arizona contain the deeply buried porphyry copper system at Red Mountain as well as a number of other base- and precious-metal mines and prospects. The range contains complex Basin and Range geology with units ranging in age from Precambrian to Holocene. Rock types present include igneous intrusive and extrusive units as well as sedimentary and metamorphic units, most of which have been tectonically disturbed. A total of 264 stream-sediment samples were collected and analyzed for 32 elements. Geochemical maps for Sb, Ag, Pb, Te, B, Mn, Au, Zn, Cu (total), Cu (cold-extractable), and Mo, as well as for Cu (cold-extractable)/Cu (total) and Fe/Mn, are presented. Anomaly patterns for these elements generally occur over the Red Mountain deposit and (or) along a north-northwest trend parallel to the major Harshaw Creek Fault. Much of the entire area sampled contains widespread anomalies for Pb, Te, and Cu; the other elements are only locally anomalous. Various plots of ratios of Cu (cold-extractable) to Cu (total) did not produce any new information not readily apparent on either one of the two copper maps. A plot of ratios of Fe to Mn delineated many areas of pyrite mineralization. Several of these areas may represent the pyritic halos around deeply buried porphyry copper systems. The best ore guide for the Red Mountain porphyry system is the coincidence of positive anomalies of Mo, Pb, and Te and a negative anomaly of Mn. Other areas with anomalies of the same suite of elements are present within the Patagonia Mountains. It is concluded that geochemical sampling, even in a highly contaminated area, can be useful in delineating major geologic features, such as porphyry copper belts and major faults. Multielement geochemical surveys on a regional scale can effectively locate large, deeply buried, zoned mineral systems such as that at Red Mountain. Plots of element ratios, where adequately understood, can provide geochemical information

  11. Channel change on the Santa Cruz River, Pima County, Arizona, 1936-86

    USGS Publications Warehouse

    Parker, J.T.

    1993-01-01

    The Santa Cruz River, an ephemeral river that drains 8,581 square miles in southeastern Arizona, has a long history of channel instability. Since the late 19th century, lateral channel erosion has caused extensive property damage, particularly in Pima County. During the flood of 1983, about $100 million damage was caused in the Tucson area alone; most damage resulted from bank erosion on the Santa Cruz River and its tributaries. The nature, magni- tude, location, and frequency of channel change on the Santa Cruz River were highly variable in time and space from 1936 through 1986 along a 70-mile reach in Pima County, Arizona. Four mechanisms of lateral channel change--channel migration, avulsion and meander cutoff, channel widening, and arroyo widening--were identified on the Santa Cruz River. The dominant mechanism in a reach depends on channel morphology and flood magnitude. The dominant vertical change has been degradation. The timing and magnitude of channel change at a particular location are controlled primarily by hydroclimatic factors such as magnitude, duration, intensity, and frequency of precipitation and floods. The location of channel change and its magnitude in response to a given discharge are controlled largely by topographic, geologic, hydraulic, and artificial factors. Although much of the present morphology of the Santa Cruz River is the result of recent large floods, a direct link between hydroclimatic con- ditions and channel change is not always evident because resistance of the channel to erosion varies with time. (USGS)

  12. Paleoenvironmental reconstruction of the coastal Monte Léon and Santa Cruz formations (Early Miocene) at Rincón del Buque, Southern Patagonia: A revisited locality

    NASA Astrophysics Data System (ADS)

    Raigemborn, M. Sol; Matheos, Sergio D.; Krapovickas, Verónica; Vizcaíno, Sergio F.; Bargo, M. Susana; Kay, Richard F.; Fernicola, Juan C.; Zapata, Luciano

    2015-07-01

    Sedimentological, ichnological and paleontological analyses of the Early Miocene uppermost Monte León Formation and the lower part of the Santa Cruz Formation were carried out in Rincón del Buque (RDB), a fossiliferous locality north of Río Coyle in Santa Cruz Province, Patagonia, Argentina. This locality is of special importance because it contains the basal contact between the Monte Léon (MLF) and the Santa Cruz (SCF) formations and because it preserves a rich fossil assemblage of marine invertebrates and marine trace fossils, and terrestrial vertebrates and plants, which has not been extensively studied. A ˜90 m-thick section of the MLF and the SCF that crops out at RDB was selected for this study. Eleven facies associations (FA) are described, which are, from base to top: subtidal-intertidal deposits with Crassotrea orbignyi and bioturbation of the Skolithos-Cruziana ichnofacies (FA1); tidal creek deposits with terrestrial fossil mammals and Ophiomorpha isp. burrows (FA2); tidal flat deposits with Glossifungites ichnofacies (FA3); deposits of tidal channels (FA4) and tidal sand flats (FA5) both with and impoverish Skolithos ichnofacies associated; marsh deposits (FA6); tidal point bar deposits recording a depauperate mixture of both the Skolithos and Cruziana ichnofacies (FA7); fluvial channel deposits (FA8); fluvial point bar deposits (FA9); floodplain deposits (FA10); and pyroclastic and volcaniclastic deposits of the floodplain where terrestrial fossil mammal remains occur (FA11). The transition of the MLF-SCF at RDB reflects a changing depositional environment from the outer part of an estuary (FA1) through the central (FA2-6) to inner part of a tide-dominated estuary (FA7). Finally a fluvial system occurs with single channels of relatively low energy and low sinuosity enclosed by a broad, low-energy floodplain dominated by partially edaphized ash-fall, sheet-flood, and overbank deposits (FA8-11). Pyroclastic and volcaniclastic materials throughout the

  13. Channel change on the Santa Cruz River, Pima County, Arizona, 1936-86

    USGS Publications Warehouse

    Parker, John T.

    1995-01-01

    The Santa Cruz River in southeastern Arizona has a long history of channel instability. Since the late 19th century, lateral channel erosion has caused extensive property damage, particularly in Pima County. The dominant mechanism of channel change in a reach depends on channel morphology and flood magnitude. The timing and magnitude of channel change are controlled primarily by hydroclimatic factors. The location of change is controlled largely by topographic, geologic, hydraulic, and artificial factors.

  14. Reconnaissance of alluvial fans as potential sources of gravel aggregate, Santa Cruz River valley, Southeast Arizona

    USGS Publications Warehouse

    Lindsey, David A.; Melick, Roger

    2002-01-01

    This investigation was conducted to provide information on the aggregate potential of alluvial fan sediments in the Santa Cruz River valley. Pebble lithology, roundness, and particle size were determined in the field, and structures and textures of alluvial fan sediments were photographed and described. Additional measurements of particle size on digital photographs were made on a computer screen. Digital elevation models were acquired and compiled for viewing the areal extent of selected fans. Alluvial fan gravel in the Santa Cruz River valley reflects the lithology of its source. Gravel derived from granitic and gneissic terrane of the Tortolita, Santa Catalina, and Rincon Mountains weathers to grus and is generally inferior for use as aggregate. Gravel derived from the Tucson, Sierrita, and Tumacacori Mountains is composed mostly of angular particles of volcanic rock, much of it felsic in composition. This angular volcanic gravel should be suitable for use in asphalt but may require treatment for alkali-silica reaction prior to use in concrete. Gravel derived from the Santa Rita Mountains is of mixed plutonic (mostly granitic rocks), volcanic (mostly felsic rocks), and sedimentary (sandstone and carbonate rock) composition. The sedimentary component tends to make gravel derived from the Santa Rita Mountains slightly more rounded than other fan gravel. The coarsest (pebble, cobble, and boulder) gravel is found near the heads (proximal part) of alluvial fans. At the foot (distal part) of alluvial fans, most gravel is pebble-sized and interbedded with sand and silt. Some of the coarsest gravel was observed near the head of the Madera Canyon, Montosa Canyon, and Esperanza Wash fans. The large Cienega Creek fan, located immediately south and southeast of Tucson, consists entirely of distal-fan pebble gravel, sand, and silt.

  15. Climatic variability and flood frequency of the Santa Cruz River, Pima County, Arizona

    USGS Publications Warehouse

    Webb, Robert H.; Betancourt, Julio L.

    1992-01-01

    Past estimates of the 100-year flood for the Santa Cruz River at Tucson, Arizona, range from 572 to 2,780 cubic meters per second. An apparent increase in flood magnitude during the past two decades raises concern that the annual flood series is nonstationary in time. The apparent increase is accompanied by more annual floods occurring in fall and winter and fewer in summer. This greater mixture of storm types that produce annual flood peaks is caused by a higher frequency of meridional flow in the upper-air circulation and increased variance of ocean-atmosphere conditions in the tropical Pacific Ocean. Estimation of flood frequency on the Santa Cruz River is complicated because climate affects the magnitude and frequency of storms that cause floods. Mean discharge does not change significantly, but the variance and skew coefficient of the distribution of annual floods change with time. The 100-year flood during El Niffo-Southern Oscillation conditions is 1,300 cubic meters per second, more than double the value for other years. The increase is mostly caused by an increase in recurvature of dissipating tropical cyclones into the Southwestern United States during El Niffo-Southern Oscillation conditions. Flood frequency based on hydroclimatology was determined by combining populations of floods caused by monsoonal storms, frontal systems, and dissipating tropical cyclones. For 1930-59, annual flood frequency is dominated by monsoonal floods, and the estimated 100-year flood is 323 cubic meters per second. For 1960-86, annual flood frequency at recurrence intervals of greater than 10 years is dominated by floods caused by dissipating tropical cyclones, and the estimated 100-year flood is 1,660 cubic meters per second. For design purposes, 1,660 cubic meters per second might be an appropriate value for the 100-year flood at Tucson, assuming that climatic conditions during 1960-86 are representative of conditions expected in the immediate future.

  16. Channel-changing processes on the Santa Cruz River, Pima County, Arizona, 1936-86

    USGS Publications Warehouse

    Parker, John T.C.; ,

    1990-01-01

    Lateral channel change on the mainly ephemeral Santa Cruz River, Pima County, Arizona, causes damage and has spawned costly efforts to control bank erosion. Aerial photographs, historical data, and field observations are used to document the history of channel change since 1936. Variability in the nature and degree of channel change over time and space is shown. Three major channel change processes are: (1) migration by bank erosion during meander migration or initiation; (2) avulsion by overbank flooding and flood plain incision; (3) widening by erosion of low, cohesionless banks during floods and arroyo widening by undercutting and mass wasting of deeply incised vertical walls. The first process generally is a product of low to moderate flows or waning high flows; the others result mainly from higher flows, though sensitive arroyo walls may erode during relatively low flows. Channel morphology, bank resistance, and hydrology are factors determining the dominant channel-changing process on a particular reach of the river. Present river morphology reflects high flows since the 1960's.

  17. Influence of the Nogales International Wastewater Treatment Plant on surface water in the Santa Cruz River and local aquifers

    NASA Astrophysics Data System (ADS)

    LaBrie, H. M.; Brusseau, M. L.; Huth, H.

    2015-12-01

    As water resources become limited in Arizona due to drought and excessive use of ground water, treated wastewater effluent is becoming essential in creating natural ecosystems and recharging the decreasing groundwater supplies. Therefore, future water supplies are heavily dependent of the flow (quantity) and quality of the treated effluent. The Nogales International Wastewater Treatment Plant (NIWTP) releases treated wastewater from both Nogales, Arizona and Nogales, Sonora, Mexico into the Santa Cruz River. This released effluent not only has the potential to impact surface water, but also groundwater supplies in Southern Arizona. In the recent past, the NIWTP has had reoccurring issues with elevated levels of cadmium, in addition to other, more infrequent, releases of high amounts of other metals. The industrial demographic of the region, as well as limited water quality regulations in Mexico makes the NIWTP and its treated effluent an important area of study. In addition, outdated infrastructure can potentially lead to damaging environmental impacts, as well as human health concerns. The Santa Cruz River has been monitored and studied in the past, but in recent years, there has been a halt in research regarding the state of the river. Data from existing water quality databases and recent sampling reports are used to address research questions regarding the state of the Santa Cruz River. These questions include: 1) How will change in flow eventually impact surface water and future groundwater supplies 2) What factors influence this flow (such as extreme flooding and drought) 3) What is the impact of effluent on surface water quality 4) Can changes in surface water quality impact groundwater quality 5) How do soil characteristics and surface flow impact the transport of released contaminants Although outreach to stakeholders across the border and updated infrastructure has improved the quality of water in the river, there are many areas to improve upon as the

  18. Push moraines in the upper valley of Santa Cruz river, southwest Argentina. Structural analysis and relationship with Late Pleistocene paleoclimate

    NASA Astrophysics Data System (ADS)

    Goyanes, Gabriel; Massabie, Armando

    2015-01-01

    The upper cliff of the Santa Cruz River was used to assess the proglacial environments of the Argentino Glacier outlet of Late Pleistocene age. These cliffs show glaciolacustrine, fluvioglacial and till deposits, where only the first one are deformed. Glacial landforms in the area and these structures suggest that the ice mass advanced, topographically controlled, towards the east from the Patagonian Ice Sheet pushing up the proglacial sediments. The spatial arrangement of thrusts and overturned folds, the drumlins-flutes moraine directions and the end moraines shape, allow inferring the dynamic and the Argentino glacier profile. Detailed analyses of the glaciotectonic structures indicate that these have two origins: load in the north with stress transfer to the southeast, and push from the west. Through the analysis of deformed sediments, their thickness and their sedimentary and structural features, three zones of deformations were recognized. Each of these zones was associated to glacial advances because of changes of the regional climate conditions.

  19. Epilithic algae distribution along a chemical gradient in a naturally acidic river, Río Agrio (Patagonia, Argentina).

    PubMed

    Baffico, Gustavo D

    2010-04-01

    The epilithic algae distribution along a pH gradient and the relationship between the chemical gradient and biomass development were studied in Río Agrio, a naturally acidic river located in Patagonia (Argentina). The epilithic community was monitored during the summer of three consecutive years in sites located above and below the entrance of tributaries. The epilithic community showed differences between sites based on the chemical composition of the water and the precipitates that appear on the streambed of the river. The lowest biomass, diversity, and number of species were found at the most extreme part of the river in terms of pH (ca. 2) and element concentrations. Euglena mutabilis was the dominant species in this section of the river. As pH increased (ca. 3), the community changed to be dominated by filamentous green algae (Ulothrix spp., Mougeotia sp., Klebsormidium sp.) showing luxuriant growths in terms of biomass. With the inflow of a neutral tributary, the pH of Río Agrio increased above 3, and the precipitates of orange-red iron hydroxides appeared. The algal community was not affected by these precipitates or the low P concentrations, along the next 30 km of river downstream from this site. The apparent physical stress that the precipitates impose on algae is in fact a dynamic reservoir of P because diel cycle of Fe could be promoting precipitation and redissolution processes that binds and releases P from these precipitates. Where the pH increased above 6, precipitates of aluminum hydroxides appeared. At this site, the epilithic biomass and density decreased, some algae species changed, but the diversity and the number of species in general remained consistent with the upstream values. The physical stress of the Al precipitates on the algae is added to the chemical stress that represents the sequestering of P in these precipitates that are not redissolved, resulting P a limiting nutrient for algae growth.

  20. Meltwater palaeohydrology of the Baker River basin (Chile/Argentina) during Late Pleistocene deglaciation of the Northern Patagonia Icefield

    NASA Astrophysics Data System (ADS)

    Thorndycraft, Varyl; Bendle, Jacob; Benito, Gerardo; Sancho, Carlos; Palmer, Adrian; Rodríguez, Xavier

    2016-04-01

    The Late Pleistocene deglaciation of the Northern Patagonia Icefield (NPI) was characterised by rapid ice sheet thinning and retreat, and the development of large proglacial lake systems characterised by continental scale drainage reversals. In this region, research has focused primarily on the identification of former ice-limits (e.g. moraine ridges) for geochronological analyses, with little attention given to the meltwater palaeohydrology of major river valleys. The Baker River catchment drains the majority of the eastern ice shed of the NPI, with a basin area of 29,000 km2 that includes the large transboundary lakes of General Carrera/Buenos Aires and Cochrane/Puerreydón. The Baker River valley is aligned north to south, crossing the east-west valleys of the main NPI outflow glaciers, and thus represents an important aspect of regional Late Pleistocene palaeogeography. The Baker River valley therefore has the potential to refine regional models of deglaciation through better understanding of relationships between glacier dynamics, ice dammed lakes and meltwater pathways. Here we present geomorphological mapping from the Atlantic-Pacific drainage divide (over 150 km east of the Cordillera) to the lower Baker valley, in order to reconstruct Late Pleistocene palaeohydrology. We provide new mapping of palaeolake shoreline elevations and evidence for glacial lake outburst flood (GLOF) pathways that require a re-evaluation of the currently accepted palaeogeographic models. For example, the palaeohydrological evidence does not support existing models of a unified Buenos Aires/Puerreydón mega-lake at ca. 400m elevation. We propose a relative chronology of palaeohydrological events that help refine the published moraine chronology derived from cosmogenic nuclide exposure dating. Controls on Late Pleistocene meltwater palaeohydrology of the Baker catchment are discussed, including the interplay of glacial processes and regional tectonics, in particular, dynamic

  1. The distribution and extent of heavy metal accumulation in song sparrows along Arizona's upper Santa Cruz River

    USGS Publications Warehouse

    Lester, Michael B.; van Riper, Charles

    2014-01-01

    Heavy metals are persistent environmental contaminants, and transport of metals into the environment poses a threat to ecosystems, as plants and wildlife are susceptible to long-term exposure, bioaccumulation, and potential toxicity. We investigated the distribution and cascading extent of heavy metal accumulation in southwestern song sparrows (Melospiza melodia fallax), a resident riparian bird species that occurs along the US/Mexico border in Arizona’s upper Santa Cruz River watershed. This study had three goals: (1) quantify the degree of heavy metal accumulation in sparrows and determine the distributional patterns among study sites, (2) compare concentrations of metals found in this study to those found in studies performed prior to a 2009 international wastewater facility upgrade, and (3) assess the condition of song sparrows among sites with differing potential levels of exposure. We examined five study sites along with a reference site that reflect different potential sources of contamination. Body mass residuals and leukocyte counts were used to assess sparrow condition. Birds at our study sites typically had higher metal concentrations than birds at the reference site. Copper, mercury, nickel, and selenium in song sparrows did exceed background levels, although most metals were below background concentrations determined from previous studies. Song sparrows generally showed lower heavy metal concentrations compared to studies conducted prior to the 2009 wastewater facility upgrade. We found no cascading effects as a result of metal exposure.

  2. Allochthonous subsidies of organic matter across a lake-river-fjord landscape in the Chilean Patagonia: Implications for marine zooplankton in inner fjord areas

    NASA Astrophysics Data System (ADS)

    Vargas, Cristian A.; Martinez, Rodrigo A.; San Martin, Valeska; Aguayo, Mauricio; Silva, Nelson; Torres, Rodrigo

    2011-03-01

    Ecosystems can act as both sources and sinks of allochthonous nutrients and organic matter. In this sense, fjord ecosystems are a typical interface and buffer zone between freshwater systems, glaciated continents, and the coastal ocean. In order to evaluate the potential sources and composition of organic matter across fjord ecosystems, we characterized particulate organic matter along a lake-river-fjord corridor in the Chilean Patagonia using stable isotope (δ 13C) and lipid (fatty acid composition) biomarker analyses. Furthermore, estimates of zooplankton carbon ingestion rates and measurements of δ 13C and δ 15N in zooplankton (copepods) were used to evaluate the implications of allochthonous subsidies for copepods inhabiting inner fjord areas. Our results showed that riverine freshwater flows contributed an important amount of dissolved silicon but, scarce nitrate and phosphate to the brackish surface layer of the fjord ecosystem. Isotopic signatures of particulate organic matter from lakes and rivers were distinct from their counterparts in oceanic influenced stations. Terrestrial allochthonous sources could support around 68-86% of the particulate organic carbon in the river plume and glacier melting areas, whereas fatty acid concentrations were maximal in the surface waters of the Pascua and Baker river plumes. Estimates of carbon ingestion rates and δ 13C in copepods from the river plume areas indicated that terrestrial carbon could account for a significant percentage of the copepod body carbon (20-50%) during periods of food limitation. Particulate organic matter from the Pascua River showed a greater allochthonous contribution of terrigenous/vascular plant sources. Rivers may provide fjord ecosystems with allochthonous contributions from different sources because of the distinct vegetation coverage and land use along each river's watershed. These observations have significant implications for the management of local riverine areas in the context of

  3. 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.

  4. Reconstructing streamflow variation of the Baker River from tree-rings in Northern Patagonia since 1765

    NASA Astrophysics Data System (ADS)

    Lara, Antonio; Bahamondez, Alejandra; González-Reyes, Alvaro; Muñoz, Ariel A.; Cuq, Emilio; Ruiz-Gómez, Carolina

    2015-10-01

    The understanding of the long-term variation of large rivers streamflow with a high economic and social relevance is necessary in order to improve the planning and management of water resources in different regions of the world. The Baker River has the highest mean discharge of those draining both slopes of the Andes South of 20°S and it is among the six rivers with the highest mean streamflow in the Pacific domain of South America (1100 m3 s-1 at its outlet). It drains an international basin of 29,000 km2 shared by Chile and Argentina and has a high ecologic and economic value including conservation, tourism, recreational fishing, and projected hydropower. This study reconstructs the austral summer - early fall (January-April) streamflow for the Baker River from Nothofagus pumilio tree-rings for the period 1765-2004. Summer streamflow represents 45.2% of the annual discharge. The regression model for the period (1961-2004) explains 54% of the variance of the Baker River streamflow (R2adj = 0.54). The most significant temporal pattern in the record is the sustained decline since the 1980s (τ = -0.633, p = 1.0144 ∗ 10-5 for the 1985-2004 period), which is unprecedented since 1765. The Correlation of the Baker streamflow with the November-April observed Southern Annular Mode (SAM) is significant (1961-2004, r = -0.55, p < 0.001). The Baker record is also correlated with the available SAM tree-ring reconstruction based on other species when both series are filtered with a 25-year spline and detrended (1765-2004, r = -0.41, p < 0.01), emphasizing SAM as the main climatic forcing of the Baker streamflow. Three of the five summers with the highest streamflow in the entire reconstructed record occurred after the 1950s (1977, 1958 and 1959). The causes of this high streamflow events are not yet clear and cannot be associated with the reported recent increase in the frequency of glacial-lake outburst floods (GLOFs). The decreasing trend in the observed and reconstructed

  5. Changing levels of heavy metal accumulation in birds at Tumacacori National Historic Park along the Upper Santa Cruz River Watershed in southern Arizona

    USGS Publications Warehouse

    Van Riper, Charles; Lester, Michael B.

    2016-01-01

    National Parks and other protected areas can be influenced by contamination from outside their boundaries. This is particularly true of smaller parks and those in riparian ecosystems, a habitat that in arid environments provides critical habitat for breeding, migratory, and wintering birds. Animals living in contaminated areas are susceptible to adverse health effects as a result of long-term exposure and bioaccumulation of heavy metals. We investigated the distribution and cascading extent of heavy metal accumulation in Song Sparrows (Melospiza melodia) at Tumacacori National Historic Park (TUMA) along the upper Santa Cruz River watershed in southern Arizona. This study had three goals: (1) quantify the concentrations and distributional patterns of heavy metals in blood and feathers of Song Sparrows at Tumacacori National Historic Park, (2) quantify hematocrit values, body conditions (that is, residual body mass), and immune conditions of Song Sparrows in the park (3) compare our findings with prior studies at the park to assess the extent of heavy metal accumulation in birds at downstream sites after the 2009 wastewater treatment plant upgrade, and (4) quantify concentrations and distributional patterns of heavy metals in blood and feathers of Song Sparrows among six study sites throughout the upper Santa Cruz River watershed. This study design would allow us to more accurately assess song sparrow condition and blood parameters among sites with differing potential sources of contamination exposure, and how each location could have contributed to heavy metal levels of birds in the park.

  6. Sources and distribution of aliphatic and polyaromatic hydrocarbons in sediments from the Neuquen River, Argentine Patagonia.

    PubMed

    Monza, Liliana B; Loewy, Ruth M; Savini, Mónica C; Pechen de d'Angelo, Ana M

    2013-01-01

    Spatial distribution and probable sources of aliphatic and polyaromatic hydrocarbons (AHs, PAHs) were investigated in surface sediments collected along the bank of the Neuquen River, Argentina. Total concentrations of aliphatic hydrocarbons ranged between 0.41 and 125 μg/g dw. Six stations presented low values of resolved aliphatic hydrocarbons and the n-alkane distribution indexes applied suggested a clear biogenic source. These values can be considered the baseline levels of aliphatic hydrocarbons for the river sediments. This constitutes important information for the assessment of future impacts since a strong impulse in the exploitation of shale gas and shale oil in these zones is nowadays undergoing. For the other 11 stations, a mixture of aliphatic hydrocarbons of petrogenic and biogenic origin was observed. The spatial distribution reflects local inputs of these pollutants with a significant increase in concentrations in the lower course, where two major cities are located. The highest values of total aliphatic hydrocarbons were found in this sector which, in turn, was the only one where individual PAHs were detected.

  7. Avulsion at a drift-dominated mesotidal estuary: The Chubut River outlet, Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Isla, Federico; Espinosa, Marcela; Rubio, Belén; Escandell, Alejandra; Gerpe, Marcela; Miglioranza, Karina; Rey, Daniel; Vilas, Federico

    2015-10-01

    The Chubut River flows from the Andes to the Atlantic Ocean, and is interrupted by a single dam built at the middle valley. The lower valley is dominated by the aggradation of an alluvial plain induced by a complex of spits that enclosed the inlet in the last 5000 years. The river has reduced its flow because the blocking of the upper basin by terminal moraines during the Upper Pleistocene. At least the last two marine transgressions have flooded this estuary, and contributed to the aggradation during regressions. The area is of particular interest in regard to irrigation channels practiced since the XIX century. Today, the mean monthly flow is less than 10 m3/s although peaks of 95 m3/s have been recorded in Gaiman in July 2001. The dynamics of the estuary is dominated by waves (wave-dominated estuary) as tidal effects attenuate in less than 5 km. Three vibracores were collected within this floodplain: (a) at Gaiman, an area without any effect of the sea (35 km from the coast); (b) at Trelew, at the former avulsion plain of the river (18 km from the coast); and (c) at Playa Magagna, a saltmarsh located 0.4 km from the beach. At the Gaiman core (1.54 m long) fresh-water epiphytic diatoms dominate (Epithemia sorex, Cocconeis placentula, Ulnaria ulna) suggesting the aggradation of an alluvial plain. The Trelew core (2.19 m long) was collected from a deltaic plain. It was composed by fine sand with organic matter at the base that evolved into silty layers to the top. Several unconformities and laminae with heavy minerals were detected by their geochemical composition analysed by micro X-ray fluorescence (Itrax XRF core scanner). Fine-sand laminated layers were perfectly detected by their high content in S and Cl. On the other hand, mud layers presented lower content in Mg and Al with increments in Ca and V. The core from the marsh area (1.67 m long) was analysed in terms of the diatom evolution in order to detect Holocene sea-level and salinity effects. The sand flats

  8. PBDEs, PCBs and organochlorine pesticides distribution in edible fish from Negro River basin, Argentinean Patagonia.

    PubMed

    Ondarza, P M; Gonzalez, M; Fillmann, G; Miglioranza, K S B

    2014-01-01

    DDTs, endosulfans, HCHs, chlordanes, PCBs and PBDEs levels were determined in different tissues of patagonian silverside (Odontesthes hatcheri) from the Upper (UV), Middle (MV) and Lower (LV) valleys of the Negro River, Argentina. Results showed a direct relation between pollutant levels in fish and land uses along the basin. All tissues showed decreasing levels from headwaters (UV) to downstream (LV). A significant predominance of organochlorine pesticides (306-3,449 ng g(-1) lipid) followed by ΣPCBs (65-3,102 ng g(-1) lipid) and ΣPBDEs (22-870 ng g(-1) lipid) was observed in all tissues and valleys, suggesting agriculture as the main source of pollutants in this basin. Pesticides were dominated by DDTs (90% pp'-DDE) followed by endosulfan (α->β->sulfate), γ-HCH and γ-chlordane showing the prevalence of legacy compounds. Endosulfan levels point out the current use of technical endosulfan in the surrounding areas. The highest PCBs and PBDEs concentrations observed in fish from UV were associated to hydroelectric power plants and industries established upstream. PCB fingerprint presented a prevailing contribution of hexa-CBs (66 ± 7%) and penta-CBs (27 ± 9%), with a similar composition to Aroclor 1254-1260. The predominance of BDE-47 (69 ± 17%) among PBDEs, followed by BDE-100 and BDE-99, suggests possible debromination processes. These results were similar to worldwide trends found in fishes and environmental compartments. PCBs levels in silverside muscles along the Negro River exceeded the maximum limits for safe consumption, suggesting a possible human health risk related to silverside ingest. Therefore, a continued long-term monitoring of organic contaminants in fishes is needed in order to assess the potential risk for human health.

  9. Aquatic habitat modifications in La Plata River basin, Patagonia and associated marine areas.

    PubMed

    Mugetti, Ana Cristina; Calcagno, Alberto Tomás; Brieva, Carlos Alberto; Giangiobbe, María Silvia; Pagani, Andrea; Gonzalez, Silvia

    2004-02-01

    This paper describes the environmental characteristics and situation of aquatic habitats and communities in southern continental and maritime areas of southeastern South America (Patagonian Shelf GIWA Subregion), resulting from an overall assessment carried out within the framework of a GIWA project, mostly on the basis of publicly available data. The main focus of the analysis was on the current situation of transboundary water resources and anthropogenic impacts. In the inland waters, habitat and community modifications result, principally, from dams and reservoirs built in the main watercourses for hydroelectric power generation and other uses. The transformation of lotic environments into lentic ones have affected habitats and altered biotic communities. In the La Plata River basin, invasive exotic species have displaced native ones. Habitats in the ocean have been degraded, as their biodiversity becomes affected by overfishing and pollution. This article includes a discussion on the causal chain and the policy options elaborated for the Coastal Ecosystem of Buenos Aires province and the Argentinean-Uruguayan Common Fishing Zone, where fishing resources are shared by both countries.

  10. Natural and anthropogenic factors affecting the structure of the benthic macroinvertebrate community in an effluent-dominated reach of the Santa Cruz River, AZ

    USGS Publications Warehouse

    Boyle, T.P.; Fraleigh, H.D.

    2003-01-01

    This study provides an assessment of the ecological conditions of a 46-km effluent-dominated stream section of the Santa Cruz River in the vicinity of the International Waste Water Treatment Plant, Nogales, AZ. We associated changes in the structure of the macroinvertebrate community to natural and anthropogenic chemical and physical variables using multivariate analysis. The analysis shows that biological criteria for effluent-dominated streams can be established using macroinvertebrate community attributes only with an understanding of the contribution of three classes of variables on the community structure: (1) low flow hydrological discharge as affected by groundwater withdrawals, treatment plant discharge, and subsurface geomorphology; (2) chemical composition of the treatment plant discharge and natural dilution; and (3) naturally produced floods resulting from seasonality of precipitation. ?? 2003 Elsevier Science Ltd. All rights reserved.

  11. Processes of Terrace Formation on the Piedmont of the Santa Cruz River Valley During Quaternary Time, Green Valley-Tubac Area, Southeastern Arizona

    USGS Publications Warehouse

    Lindsey, David A.; Van Gosen, Bradley S.

    2010-01-01

    In this report we describe a series of stepped Quaternary terraces on some piedmont tributaries of the Santa Cruz River valley in southeastern Arizona. These terraces began to form in early Pleistocene time, after major basin-and-range faulting ceased, with lateral planation of basin fill and deposition of thin fans of alluvium. At the end of this cycle of erosion and deposition, tributaries of the Santa Cruz River began the process of dissection and terrace formation that continues to the present. Vertical cutting alternated with periods of equilibrium, during which streams cut laterally and left thin deposits of channel fill. The distribution of terraces was mapped and compiled with adjacent mapping to produce a regional picture of piedmont stream history in the middle part of the Santa Cruz River valley. For selected tributaries, the thickness of terrace fill was measured, particle size and lithology of gravel were determined, and sedimentary features were photographed and described. Mapping of terrace stratigraphy revealed that on two tributaries, Madera Canyon Wash and Montosa Canyon Wash, stream piracy has played an important role in piedmont landscape development. On two other tributaries, Cottonwood Canyon Wash and Josephine Canyon Wash, rapid downcutting preempted piracy. Two types of terraces are recognized: erosional and depositional. Gravel in thin erosional terraces has Trask sorting coefficients and sedimentary structures typical of streamflood deposits, replete with bar-and-swale surface topography on young terraces. Erosional-terrace fill represents the channel fill of the stream that cuts the terrace; the thickness of the fill indicates the depth of channel scour. In contrast to erosional terraces, depositional terraces show evidence of repeated deposition and net aggradation, as indicated by their thickness (as much as 20+ m) and weakly bedded structure. Depositional terraces are common below mountain-front canyon mouths where streams drop their

  12. High Performance Computing-based Assessment of the Impacts of Climate Change on the Santa Cruz and San Pedro River Basin at Very High Resolution

    NASA Astrophysics Data System (ADS)

    Robles-Morua, A.; Vivoni, E. R.; Rivera-Fernandez, E. R.; Dominguez, F.; Meixner, T.

    2012-12-01

    Assessing the impact of climate change on large river basins in the southwestern United States is important given the natural water scarcity in the region. The bimodal distribution of annual precipitation also presents a challenge as differential climate impacts during the winter and summer seasons are not currently well understood. In this work, we focus on the hydrological consequences of climate change in the Santa Cruz and San Pedro river basins along the Arizona-Sonora border at high spatiotemporal resolutions (~100 m and ~1 hour). These river systems support rich ecological communities along riparian corridors that provide habitat to migratory birds and support recreational and economic activities. Determining the climate impacts on riparian communities involves assessing how river flows and groundwater recharge will change with altered temperature and precipitation regimes. In this study, we use a distributed hydrologic model, known as the TIN-based Real-time Integrated Basin Simulator (tRIBS), to generate simulated hydrological fields under historical (1991-2000) and climate change (2031-2040) scenarios obtained from an application of the Weather Research and Forecast (WRF) model. Using the distributed model, we transform the meteorological scenarios from WRF at 10-km, hourly resolution into predictions of the annual water budget, seasonal land surface fluxes and individual hydrographs of flood and recharge events. For this contribution, we selected two full years in the historical period and in the future scenario that represent wet and dry conditions for each decade. Given the size of the two basins, we rely on a high performance computing platform and a parallel domain discretization using sub-basin partitioning with higher resolutions maintained at experimental catchments in each river basin. Model simulations utilize best-available data across the Arizona-Sonora border on topography, land cover and soils obtained from analysis of remotely

  13. Distribution and extent of heavy metal accumulation in Song Sparrows (Melospiza melodia), upper Santa Cruz River watershed, southern Arizona, 2011-12

    USGS Publications Warehouse

    Lester, Michael B.; van Riper, Charles

    2014-01-01

    Riparian ecosystems in arid environments provide critical habitat for breeding, migratory, and wintering birds, yet are often at risk of contamination by heavy metals. Birds and other animals living in contaminated areas are susceptible to adverse health effects as a result of long-term exposure and bioaccumulation of heavy metals. We investigated the distribution and cascading extent of heavy metal accumulation in Song Sparrows (Melospiza melodia) in Arizona’s upper Santa Cruz River watershed. This study had three goals: (1) quantify the degree of heavy metal accumulation in sparrows and determine the distributional patterns among study sites, (2) compare concentrations of metals found in this study to those found in studies performed prior to the 2009 international wastewater treatment plant upgrade, and (3) assess sparrow condition among sites with differing potential sources of contamination exposure. We examined six study sites that reflected different potential sources of contamination. Hematocrit values, body mass residuals, and leukocyte counts were used to assess sparrow condition. Cadmium, copper, mercury, nickel, and selenium exceeded background concentrations at some sites, but generally were lower than or similar to concentrations found in earlier studies performed prior to the 2009 international wastewater treatment plant upgrade. Concentrations were higher in recaptured birds in 2012 than in 2011 for 7 metals in feathers and 14 metals in blood, suggesting possible bioaccumulation. We found no cascading effects as a result of heavy metal exposure, but did find that heavy metal concentrations were reduced following the 2009 international wastewater treatment plant upgrade.

  14. Intra and Inter-Population Morphological Variation of Shape and Size of the Chilean Magnificent Beetle, Ceroglossus chilensis in the Baker River Basin, Chilean Patagonia

    PubMed Central

    Benítez, Hugo A.; Briones, Raúl; Jerez, Viviane

    2011-01-01

    The alteration of habitat generates different degrees of stress in insects. It has been suggested that the degrees of phenotypic disturbances reflect the ability of an individual to overcome the effects of stress. The Baker River Basin in the Aysén Region, Chilean Patagonia has a very fragmented landscape, due to the destruction of the native forest and the use of land for agriculture and animal husbandry. This alteration should generate different degrees of disturbances in the insect communities, whose effects may be quantified by geometric morphometric tools. We analyzed morphological differences in 244 males and 133 females of the the Chilean magnificent beetle, Ceroglossus chilensis (Eschscholtz) (Coleoptera: Carabidae) collected in January, 2007, in mixed forests of Nothofagus dombeyi Mirbel (Ørsted) (Fagales: Nothofagaceae) and N. nitida Hofmus and in Second-growth forest of N. pumilio (Poepp. & Endl.) Krasser. Males were generally wider in the pronotum, while females had wider abdominal sternites. Although there were significant differences in shape and size between mature forests and second-growth forest, these were less significant among the sites within each type of vegetal formation. Individuals had more shape variations in the mature forest. We suggest that differences in shape are due at least in part to the isolation of the habitat. The differences found between sexes raises the question of how morphological variations and sexual dimorphism may be affected spatially by natural selection. PMID:21870986

  15. Additional information for Leptoglossus impictus (Stål 1859) (Hemiptera: Heteroptera: Coreidae: Coreinae: Anisoscelini) from Patagonia, Argentina.

    PubMed

    Diez, Fernando; Espindola, Milton Ruiz; Cornelis, Marcela; Coscarón, María Del Carmen

    2016-01-25

    The Patagonian subregion belongs to the Andean region, and is comprised of two provinces: Central Patagonia and Subandean Patagonia. It extends from central Mendoza, widening through Neuquén, Río Negro, Chubut, and Santa Cruz, to northern Tierra del Fuego, and reaches Chile (Morrone 2006). The knowledge of terrestrial Heteroptera in this region is poor and is limited to a few contributions (e.g. Berg 1979, Breddin 1898, Pennington 1920, Faúndez & Carvajal 2011, Faundez 2015).

  16. Using High Resolution Satellite Precipitation fields to Assess the Impacts of Climate Change on the Santa Cruz and San Pedro River Basins

    NASA Astrophysics Data System (ADS)

    Robles-Morua, A.; Vivoni, E.; Rivera-Fernandez, E. R.; Dominguez, F.; Meixner, T.

    2013-05-01

    Hydrologic modeling using high spatiotemporal resolution satellite precipitation products in the southwestern United States and northwest Mexico is important given the sparse nature of available rain gauges. In addition, the bimodal distribution of annual precipitation also presents a challenge as differential climate impacts during the winter and summer seasons are not currently well understood. In this work, we focus on hydrological comparisons using rainfall forcing from a satellite-based product, downscaled GCM precipitation estimates and available ground observations. The simulations are being conducted in the Santa Cruz and San Pedro river basins along the Arizona-Sonora border at high spatiotemporal resolutions (~100 m and ~1 hour). We use a distributed hydrologic model, known as the TIN-based Real-time Integrated Basin Simulator (tRIBS), to generate simulated hydrological fields under historical (1991-2000) and climate change (2031-2040) scenarios obtained from an application of the Weather Research and Forecast (WRF) model. Using the distributed model, we transform the meteorological scenarios at 10-km, hourly resolution into predictions of the annual water budget, seasonal land surface fluxes and individual hydrographs of flood and recharge events. We compare the model outputs and rainfall fields of the WRF products against the forcing from the North American Land Data Assimilation System (NLDAS) and available ground observations from the National Climatic Data Center (NCDC) and Arizona Meteorological Network (AZMET). For this contribution, we selected two full years in the historical period and in the future scenario that represent wet and dry conditions for each decade. Given the size of the two basins, we rely on a high performance computing platform and a parallel domain discretization with higher resolutions maintained at experimental catchments in each river basin. Model simulations utilize best-available data across the Arizona-Sonora border on

  17. River runoff and regional climate of a small glaciated catchment area in the Andes in southernmost Patagonia, Chile

    NASA Astrophysics Data System (ADS)

    Schneider, C.; Moritz, M.; Kilian, R.

    2003-04-01

    The river runoff from a small partly glaciated catchment area in southernmost Patagonian Andes in Chile is measured to analyse the influence of regional precipitation and climate dependent glacier ablation on runoff. The first data from March to September 2002 were compared to climate data recorded at an automatic weather station in the area. The poster presents the first detailed hydrometeorological investigation from this part of the Andes. The investigation area is located at 53°S in southernmost South America exactly east of the main divide of the mountain range of the Andes at 72.5°W. The catchment area of about 15 km2 comprises parts of the Gran Campo Nevado Ice Cap reaching up to 1500 m asl, and the outlet glacier Glaciar Lengua which ends at a proglacial lake at 100 m asl. The Gran Campo Nevado Ice Cap is the major ice mass between the Southern Patagonian Ice field in the north and the Strait of Magallan to the South. Climate in the area is characterised by whole-year round cool and super-humid conditions with a mean annual air temperature of 5,6°C at sea level and an annual precipitation sum of approximately 7,000 mm. The Río Lengua itself meets approximately 3.5 km downstreams from the proglacial lake into the fjord system of Canal Garjado which is a branch of Seno Skyring. A continuous hourly record of water levels in the river was obtained from two digital water depth sensors. Runoff was calibrated against river level by measuring runoff at different times with the tracer method of salt dilution and with velocity measurements employing a hydrometric vane. Mean runoff was computed to about 3 m3/s with peak flows exceeding 10 m3/s. Ablation on the glacier was estimated using the degree-day method with a degree-day factor that has been calibrated previously using data from a temporal energy balance weather station on Glacíar Lengua. The correlation between runoff and air temperature and precipitation returned significant correlation coefficients of rt

  18. Two new species of Neotyphloceras (Siphonaptera: Ctenophthalmidae) from Argentinean Patagonia.

    PubMed

    Sanchez, Juliana; Lareschi, Marcela

    2014-03-27

    Two new species of Neotyphloceras Rothschild, parasites of sigmodontine rodents from Argentinean Patagonia, are described and illustrated: N. crackensis n. sp. and N. pardinasi n. sp. These species are compared with their morphologically closest relatives. Males are characterized by the shape of the upper lobe of the fixed process of clasper; the shape and chaetotaxy of the distal arm of sternum IX and by the shape of the crochet of the aedeagus; females by the contour of the distal margin of sternum VII. Neotyphloceras pardinasi n. sp. is reported from western Chubut Province, while N. crackensis n. sp. is known from the eastern regions of Chubut and Santa Cruz Provinces. With these reports, the geographical distribution of Neotyphloceras is extended to eastern Patagonia. A key to the species and subspecies of Neotyphloceras is provided.

  19. Simulation of climate change in San Francisco Bay Basins, California: Case studies in the Russian River Valley and Santa Cruz Mountains

    USGS Publications Warehouse

    Flint, Lorraine E.; Flint, Alan L.

    2012-01-01

    As a result of ongoing changes in climate, hydrologic and ecologic effects are being seen across the western United States. A regional study of how climate change affects water resources and habitats in the San Francisco Bay area relied on historical climate data and future projections of climate, which were downscaled to fine spatial scales for application to a regional water-balance model. Changes in climate, potential evapotranspiration, recharge, runoff, and climatic water deficit were modeled for the Bay Area. In addition, detailed studies in the Russian River Valley and Santa Cruz Mountains, which are on the northern and southern extremes of the Bay Area, respectively, were carried out in collaboration with local water agencies. Resource managers depend on science-based projections to inform planning exercises that result in competent adaptation to ongoing and future changes in water supply and environmental conditions. Results indicated large spatial variability in climate change and the hydrologic response across the region; although there is warming under all projections, potential change in precipitation by the end of the 21st century differed according to model. Hydrologic models predicted reduced early and late wet season runoff for the end of the century for both wetter and drier future climate projections, which could result in an extended dry season. In fact, summers are projected to be longer and drier in the future than in the past regardless of precipitation trends. While water supply could be subject to increased variability (that is, reduced reliability) due to greater variability in precipitation, water demand is likely to steadily increase because of increased evapotranspiration rates and climatic water deficit during the extended summers. Extended dry season conditions and the potential for drought, combined with unprecedented increases in precipitation, could serve as additional stressors on water quality and habitat. By focusing on the

  20. Geochronology of type Santacrucian (Middle Tertiary) Land Mammal Age, Patagonia, Argentina

    SciTech Connect

    Marshall, L.G.; Drake, R.E.; Curtis, G.H.; Butler, R.F.; Flanagan, K.M.; Naeser, C.W.

    1986-07-01

    Mammal-bearing lacustrine and tuffaceous sediments from three localities of the Santa Cruz Formation, type fauna of the Santacrucian Land Mammal Age, in Patagonia, southern Argentina, are calibrated by radioisotope dating with the aid of magnetostratigraphy. The strata range from about 17.6 Ma to perhaps 16.0 Ma, and are thus of late-early Miocene age. The Santacrucian Land Mammal Age ranges from about 18.0 Ma to about 15.0 Ma.

  1. Tectonic events reflected by palaeocurrents, zircon geochronology, and palaeobotany in the Sierra Baguales of Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Gutiérrez, Nestor M.; Le Roux, Jacobus P.; Vásquez, Ana; Carreño, Catalina; Pedroza, Viviana; Araos, José; Oyarzún, José Luis; Pablo Pino, J.; Rivera, Huber A.; Hinojosa, L. F.

    2017-01-01

    The Sierra Baguales, situated north of the Torres Del Paine National Park in the Magallanes region of southern Chile, shows a well-exposed stratigraphic sequence ranging from the Late Cretaceous to late Pliocene, which presents a unique opportunity to study the evolution of sedimentological styles and trends, palaeoclimate changes, and tectonic events during this period. The depositional environment changed from a continental slope and shelf during the Cenomanian-Campanian (Tres Pasos Formation) to deltaic between the Campanian-Maastrichtian (Dorotea Formation) and estuarine in the Lutetian-Bartonian (Man Aike Formation). During the Rupelian, a continental environment with meandering rivers and overbank marshes was established (Río Leona Formation). This area was flooded in the early Burdigalian (Estancia 25 de Mayo Formation) during the Patagonian Transgression, but emerged again during the late Burdigalian (Santa Cruz Formation). Measured palaeocurrent directions in this Mesozoic-Cenozoic succession indicate source areas situated between the northeast and east-southeast during the Late Cretaceous, east-southeast during the middle Eocene, and southwest during the early Oligocene to early Miocene. This is confirmed by detrital zircon age populations in the different units, which can be linked to probable sources of similar ages in these areas. The east-southeastern provenance is here identified as the Antarctic Peninsula or its northeastern extension, which is postulated to have been attached to Fuegian Patagonia during the Eocene. The southwestern and western sources were exhumed during gradual uplift of the Southern Patagonian Andes, coinciding with a change from marine to continental conditions in the Magallanes-Austral Basin, as well as a decrease in mean annual temperature and precipitation indicated by fossil leaves in the Río Leona Formation. The rain shadow to the east of the Andes thus started to develop here during the late Eocene-early Oligocene ( 34

  2. Patagonia Glacier, Chile

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This ASTER images was acquired on May 2, 2000 over the North Patagonia Ice Sheet, Chile near latitude 47 degrees south, longitude 73 degrees west. The image covers 36 x 30 km. The false color composite displays vegetation in red. The image dramatically shows a single large glacier, covered with crevasses. A semi-circular terminal moraine indicates that the glacier was once more extensive than at present. ASTER data are being acquired over hundreds of glaciers worldwide to measure their changes over time. Since glaciers are sensitive indicators of warming or cooling, this program can provide global data set critical to understand climate change.

    This image is located at 46.5 degrees south latitude and 73.9 degrees west longitude.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud

  3. Anaglyph, Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This view of northern Patagonia, at Los Menucos, Argentina shows remnants of relatively young volcanoes built upon an eroded plain of much older and contorted volcanic, granitic, and sedimentary rocks. The large, dark 'butterfly' pattern is a single volcano that has been deeply eroded. Large holes on the volcano's flanks indicate that they may have collapsed soon after eruption, as fluid molten rock drained out from under its cooled and solidified outer shell. At the upper left, a more recent eruption occurred and produced a small volcanic cone and a long stream of lava, which flowed down a gully. At the top of the image, volcanic intrusions permeated the older rocks resulting in a chain of small dark volcanic peaks.

    At the top center of the image, two halves of a light ellipse pattern are offset from each other. This feature is an old igneous intrusion that has been split by a right-lateral fault. The apparent offset is about 6.6 kilometers (4 miles). Tonal and topographic discontinuities reveal the fault trace as it extends across the image to the lower left. However, young unbroken basalt flows show that the fault has not been active recently.

    This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar Topography Mission, then producing the two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic mapper image used here was provided to the SRTM project by the United

  4. Stereo Pair, Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This view of northern Patagonia, at Los Menucos, Argentina shows remnants of relatively young volcanoes built upon an eroded plain of much older and contorted volcanic, granitic, and sedimentary rocks. The large purple, brown, and green 'butterfly' pattern is a single volcano that has been deeply eroded. Large holes on the volcano's flanks indicate that they may have collapsed soon after eruption, as fluid molten rock drained out from under its cooled and solidified outer shell. At the upper left, a more recent eruption occurred and produced a small volcanic cone and a long stream of lava, which flowed down a gully. At the top of the image, volcanic intrusions permeated the older rocks resulting in a chain of small dark volcanic peaks. At the top center of the image, two halves of a tan ellipse pattern are offset from each other. This feature is an old igneous intrusion that has been split by a right-lateral fault. The apparent offset is about 6.6 kilometers (4 miles). Color, tonal, and topographic discontinuities reveal the fault trace as it extends across the image to the lower left. However, young unbroken basalt flows show that the fault has not been active recently.

    This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with an enhanced Landsat 7satellite color image. The topography data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive

  5. Stereo Pair: Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This view of northern Patagonia, near El Cain, Argentina shows complexly eroded volcanic terrain, with basalt mesas, sinkholes, landslide debris, playas, and relatively few integrated drainage channels. Surrounding this site (but also extending far to the east) is a broad plateau capped by basalt, the Meseta de Somuncura. Here, near the western edge of the plateau, erosion has broken through the basalt cap in a variety of ways. On the mesas, water-filled sinkholes (lower left) are most likely the result of the collapse of old lava tubes. Along the edges of the mesas (several locations) the basalt seems to be sliding away from the plateau in a series of slices. Water erosion by overland flow is also evident, particularly in canyons where vegetation blankets the drainage channels (green patterns, bottom of image). However, overland water flow does not extend very far at any location. This entire site drains to local playas, some of which are seen here (blue). While the water can reach the playas and then evaporate, what becomes of the eroded rock debris? Wind might excavate some of the finer eroded debris, but the fate of much of the missing bedrock remains mysterious.

    This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with an enhanced Landsat 7 satellite color image. The topography data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The

  6. Anaglyph: Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This view of northern Patagonia, near El Cain, Argentina shows complexly eroded volcanic terrain, with basalt mesas, sinkholes, landslide debris, playas, and relatively few integrated drainage channels. Surrounding this site (but also extending far to the east) is a broad plateau capped by basalt, the Meseta de Somuncura. Here, near the western edge of the plateau, erosion has broken through the basalt cap in a variety of ways. On the mesas, water-filled sinkholes (lower left) are most likely the result of the collapse of old lava tubes. Along the edges of the mesas (several locations) the basalt seems to be sliding away from the plateau in a series of slices. Water erosion by overland flow is also evident, particularly in canyons where vegetation blankets the drainage channels (bright patterns, bottom of image). However, overland water flow does not extend very far at any location. This entire site drains to local playas, some of which are seen here (dark lakes with bright shores). While the water can reach the playas and then evaporate, what becomes of the eroded rock debris? Wind might excavate some of the finer eroded debris, but the fate of much of the missing bedrock remains mysterious.

    This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar Topography Mission, then producing the two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was

  7. Patagonia: A paleozoic continent adrift?

    NASA Astrophysics Data System (ADS)

    Ramos, Victor A.

    2008-11-01

    The evolution of Patagonia as an independent and exotic microcontinent from the rest of South America was a recurrent hypothesis since the XIX century, reaching notoriety during the discussion times of continental drift theory. The arrival of plate tectonics triggered different hypotheses, some of them with fixist interpretations that consider Patagonia as an autochthonous part of Gondwana, and others more mobilistic that postulate an allochthonous origin. After several decades, although some consensus exists among those hypotheses that postulate its allochthony, there is no agreement in its boundaries, subduction, accretion, and final amalgamation times to the Gondwana supercontinent. In this review the different magmatic belts are analyzed, their deformation and metamorphism, the associated sedimentary basins, as well as the existing geochronologic controls. Aware that important uncertainties still remain, a new model is proposed with two magmatic arcs: a western belt that was active from the Devonian to the mid Carboniferous, and a northern one partially coeval that led to the collision of Patagonia against the southwestern margin of Gondwana in the Lower Permian. It is hypothesized that the termination of the western magmatic arc activity was linked to the collision of the Antarctic Peninsula and associated terranes. The reconstruction of the plate tectonic history of Patagonia during the Paleozoic shows the existence of several episodes of fragmentation and rifting, convergence and accretion, renewed periods of rifting and reaccretion to the Gondwana margin. Those processes were intrinsic to the formation of Terra Australis orogen, controlled by the absolute motion of the Gondwana supercontinent and guided by successive global plate reorganizations.

  8. Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina)

    PubMed Central

    Pastor de Ward, Catalina; Lo Russo, Virginia; Villares, Gabriela; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2015-01-01

    Abstract The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia. In total 10,030 specimens of free-living marine nematodes belonging to 2 classes, 9 orders, 35 families, 78 genera and 125 species were collected. The San Julián city site presented a very high species richness. PMID:25878534

  9. 33 CFR 80.1138 - Santa Cruz Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Santa Cruz Harbor, CA. 80.1138... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1138 Santa Cruz Harbor, CA. A line drawn from the seaward extremity of the Santa Cruz Harbor East Breakwater to Santa Cruz Harbor West...

  10. Bedrock morphology and structure, upper Santa Cruz Basin, south-central Arizona, with transient electromagnetic survey data

    USGS Publications Warehouse

    Bultman, Mark W.; Page, William R.

    2016-10-31

    The upper Santa Cruz Basin is an important groundwater basin containing the regional aquifer for the city of Nogales, Arizona. This report provides data and interpretations of data aimed at better understanding the bedrock morphology and structure of the upper Santa Cruz Basin study area which encompasses the Rio Rico and Nogales 1:24,000-scale U.S. Geological Survey quadrangles. Data used in this report include the Arizona Aeromagnetic and Gravity Maps and Data referred to here as the 1996 Patagonia Aeromagnetic survey, Bouguer gravity anomaly data, and conductivity-depth transforms (CDTs) from the 1998 Santa Cruz transient electromagnetic survey (whose data are included in appendixes 1 and 2 of this report).Analyses based on magnetic gradients worked well to identify the range-front faults along the Mt. Benedict horst block, the location of possibly fault-controlled canyons to the west of Mt. Benedict, the edges of buried lava flows, and numerous other concealed faults and contacts. Applying the 1996 Patagonia aeromagnetic survey data using the horizontal gradient method produced results that were most closely correlated with the observed geology.The 1996 Patagonia aeromagnetic survey was used to estimate depth to bedrock in the upper Santa Cruz Basin study area. Three different depth estimation methods were applied to the data: Euler deconvolution, horizontal gradient magnitude, and analytic signal. The final depth to bedrock map was produced by choosing the maximum depth from each of the three methods at a given location and combining all maximum depths. In locations of rocks with a known reversed natural remanent magnetic field, gravity based depth estimates from Gettings and Houser (1997) were used.The depth to bedrock map was supported by modeling aeromagnetic anomaly data along six profiles. These cross sectional models demonstrated that by using the depth to bedrock map generated in this study, known and concealed faults, measured and estimated magnetic

  11. Shaded relief, color as height Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This topographic image of Patagonia, Argentina shows a spectacular landscape formed by volcanoes, rivers, and wind. The area is located just east of the narrow range of the Andes Mountains, about 100 kilometers (62 miles) east of the border with Chile. Interesting features include basalt-capped mesas with sinkholes (lower center), arcuate ridges of windblown beach sands downwind from a salty desert lake (upper center), young volcanic cones(right), and at least one case of what geologists call 'inverted relief'. This happens when lava flows down a valley in soft material and then the soft material is eroded away leaving the former valley as a ridge of lava. These ridges can be seen on the slopes of the volcano in the upper right. Geologists will use SRTM topographic data to study the interaction of volcanic, climatic and erosional processes.

    This shaded relief image was generated using topographic data from the Shuttle Radar Topography Mission. A computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. On flatter surfaces, the pattern of light and shadows can reveal subtle features in the terrain. Colors show the elevation as measured by SRTM. Colors range from blue at the lowest elevations to white at the highest elevations. This image contains about 1100 meters(3600 feet) of total relief. White speckles on the face of some of the mountains are holes in the data caused by steep terrain. These will be filled using coverage from an intersecting pass.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added

  12. Marine reptiles from the Late Cretaceous of northern Patagonia

    NASA Astrophysics Data System (ADS)

    Gasparini, Z.; Casadio, S.; Fernández, M.; Salgado, L.

    2001-04-01

    During the Campanian-Maastrichtian, Patagonia was flooded by the Atlantic and reduced to an archipelago. Several localities of northern Patagonia have yielded marine reptiles. Analysis of several assemblages suggests that the diversity and abundance of pelagic marine reptiles in northern Patagonia was higher by the end of the Cretaceous than previously thought. Several plesiosaurids, including Aristonectes parvidens and the polycotylid Sulcusuchus, and the first remains of mosasaurinae have been found. The Cretaceous marine reptile record from South America is scanty. Nevertheless, materials described here suggest that Tethyan and Weddelian forms converged in northern Patagonia, as seen with invertebrates.

  13. Hydrographic data from the GEF Patagonia cruises

    NASA Astrophysics Data System (ADS)

    Charo, M.; Piola, A. R.

    2014-06-01

    The hydrographic data reported here were collected within the framework of the Coastal Contamination, Prevention and Marine Management Project (Global Environment Facility (GEF) Patagonia), which was part of the scientific agenda of the United Nations Development Program (UNDP). The project goal was to strengthen efforts to improve sustainable management of marine biodiversity and reduce pollution of the Patagonia marine environment. The observational component of the project included three multidisciplinary oceanographic cruises designed to improve the knowledge base regarding the marine environment and to determine the seasonal variability of physical, biological and chemical properties of highly productive regions in the southwest South Atlantic continental shelf. The cruises were carried out on board R/V ARA Puerto Deseado, in October 2005 and March and September 2006. On each cruise, hydrographic stations were occupied along cross-shelf sections spanning the shelf from nearshore to the western boundary currents between 38° and 55° S. This paper reports the quasi-continuous vertical profiles (conductivity-temperature-depth (CTD) profiles) and underway surface temperature and salinity data collected during the GEF Patagonia cruises. These data sets are available at the National Oceanographic Data Center, NOAA, US, doi:10.7289/V5RN35S0.

  14. Hydrographic data from the GEF Patagonia cruises

    NASA Astrophysics Data System (ADS)

    Charo, M.; Piola, A. R.

    2014-02-01

    The hydrographic data reported here were collected within the framework of the Coastal Contamination, Prevention and Marine Management project (GEF Patagonia), which was part of the scientific agenda of the United Nations Development Program (UNDP). The project goal was to strengthen efforts to improve sustainable management of marine biodiversity and reduce pollution of the Patagonia marine environment. The observational component of the project included three multi-disciplinary oceanographic cruises designed to improve the knowledge base of the marine environment and to determine the seasonal variability of physical, biological and chemical properties of highly productive regions in the southwest South Atlantic continental shelf. The cruises were carried out on board R/V Ara Puerto Deseado, in October 2005 and March and September 2006. In each cruise, hydrographic stations were occupied along cross-shelf sections spanning the shelf from near-shore to the western boundary currents between 38° and 55° S. This paper reports the quasi-continuous vertical profiles (CTD) and underway surface temperature and salinity data collected during the GEF Patagonia cruises. These data sets are available at the National Oceanographic Data Center, NOAA. US, doi:10.7289/V5RN35S0.

  15. Organic carbon in glacial fjords of Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Pantoja, Silvio; Gutiérrez, Marcelo; Tapia, Fabián; Abarzúa, Leslie; Daneri, Giovanni; Reid, Brian; Díez, Beatriz

    2016-04-01

    The Southern Ice Field in Chilean Patagonia is the largest (13,000 km2) temperate ice mass in the Southern hemisphere, yearly transporting ca. 40 km3 of freshwater to fjords. This volume of fresh and cold water likely affects adjacent marine ecosystems by changing circulation, productivity, food web dynamics, and the abundance and distribution of planktonic and benthic organisms. We hypothesize that freshwater-driven availability of inorganic nutrient and transport of organic and inorganic suspended matter, as well as microbes, become a controlling factor for productivity in the fjord associated with the Baker river and Jorge Montt glacier. Both appear to be sources of silicic acid, but not of nitrate and particulate organic carbon, especially during summer, when surface PAR and glacier thawing are maximal. In contrast to Baker River, the Jorge Montt glacier is also a source of dissolved organic carbon towards a proglacial fjord and the Baker Channel, indicating that a thorough chemical description of sources (tidewater glacier and glacial river) is needed. Nitrate in fiord waters reaches ca. 15 μM at 25 m depth with no evidence of mixing up during summer. Stable isotope composition of particulate organic nitrogen reaches values as low as 3 per mil in low-salinity waters near both glacier and river. Nitrogen fixation could be depleting δ15N in organic matter, as suggested by the detection at surface waters of nif H genes belonging to diazotrophs near the Montt glacier. As diazotrophs have also been detected in other cold marine waters (e.g. Baltic Sea, Arctic Ocean) as well as glaciers and polar terrestrial waters, there is certainly a potential for both marine and freshwater microbes to contribute and have a significant impact on the Patagonian N and C budgets. Assessing the impact of freshwater on C and N fluxes and the microbial community structure in Patagonian waters will allow understanding future scenarios of rapid glacier melting. This research was funded

  16. Across the southern Andes on fin: glacial refugia, drainage reversals and a secondary contact zone revealed by the phylogeographical signal of Galaxias platei in Patagonia.

    PubMed

    Zemlak, Tyler S; Habit, Evelyn M; Walde, Sandra J; Battini, Miguel A; Adams, Emily D M; Ruzzante, Daniel E

    2008-12-01

    We employed DNA sequence variation at two mitochondrial (control region, COI) regions from 212 individuals of Galaxias platei (Pisces, Galaxiidae) collected throughout Patagonia (25 lakes/rivers) to examine how Andean orogeny and the climatic cycles throughout the Quaternary affected the genetic diversity and phylogeography of this species. Phylogenetic analyses revealed four deep genealogical lineages which likely represent the initial division of G. platei into eastern and western lineages by Andean uplift, followed by further subdivision of each lineage into separate glacial refugia by repeated Pleistocene glacial cycles. West of the Andes, refugia were likely restricted to the northern region of Patagonia with small relicts in the south, whereas eastern refugia appear to have been much larger and widespread, consisting of separate northern and southern regions that collectively spanned most of Argentinean Patagonia. The retreat of glacial ice following the last glacial maximum allowed re-colonization of central Chile from nonlocal refugia from the north and east, representing a region of secondary contact between all four glacial lineages. Northwestern glacial relicts likely followed pro-glacial lakes into central Chilean Patagonia, whereas catastrophic changes in drainage direction (Atlantic --> Pacific) for several eastern palaeolakes were the likely avenues for invasions from the east. These mechanisms, combined with evidence for recent, rapid and widespread population growth could explain the extensive contemporary distribution of G. platei throughout Patagonia.

  17. Geochemistry of soils from the San Rafael Valley, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Folger, Helen W.; Gray, Floyd

    2013-01-01

    This study was conducted to determine whether surficial geochemical methods can be used to identify subsurface mineraldeposits covered by alluvium derived from surrounding areas. The geochemical investigation focused on an anomalous geo-physical magnetic high located in the San Rafael Valley in Santa Cruz County, Arizona. The magnetic high, inferred to be asso-ciated with a buried granite intrusion, occurs beneath Quaternary alluvial and terrace deposits. Soil samples were collected at a depth of 10 to 30 centimeters below land surface along transects that traverse the inferred granite. The samples were analyzed by inductively coupled plasma-mass spectrometry and by the partial-leach Mobile Metal Ion™ method. Principal component and factor analyses showed a strong correlation between the soils and source rocks hosting base-metal replacement deposits in the Harshaw and Patagonia Mining Districts. Factor analysis also indicated areas of high metal concentrations associated with the Meadow Valley Flat. Although no definitive geochemical signature was identified for the inferred granite, concentrations otungsten and iron in the surrounding area were slightly elevated.

  18. Effects of climate change and population growth on the transboundary Santa Cruz aquifer

    USGS Publications Warehouse

    Scott, Christopher A.; Megdal, Sharon; Oroz, Lucas Antonio; Callegary, James; Vandervoet, Prescott

    2012-01-01

    The USA and Mexico have initiated comprehensive assessment of 4 of the 18 aquifers underlying their 3000 km border. Binational management of groundwater is not currently proposed. University and agency researchers plus USA and Mexican federal, state, and local agency staff have collaboratively identified key challenges facing the Santa Cruz River Valley Aquifer located between the states of Arizona and Sonora. The aquifer is subject to recharge variability, which is compounded by climate change, and is experiencing growing urban demand for groundwater. In this paper, we briefly review past, current, and projected pressures on Santa Cruz groundwater. We undertake first-order approximation of the relative magnitude of climate change and human demand drivers on the Santa Cruz water balance. Global circulation model output for emissions scenarios A1B, B1, and A2 present mixed trends, with annual precipitation projected to vary by ±20% over the 21st century. Results of our analysis indicate that urban water use will experience greater percentage change than climate-induced recharge (which remains the largest single component of the water balance). In the Mexican portion of the Santa Cruz, up to half of future total water demand will need to be met from non-aquifer sources. In the absence of water importation and with agricultural water use and rights increasingly appropriated for urban demand, wastewater is increasingly seen as a resource to meet urban demand. We consider decision making on both sides of the border and conclude by identifying short- and longer-term opportunities for further binational collaboration on transboundary aquifer assessment.

  19. Parasites in stranded cetaceans of Patagonia.

    PubMed

    Berón-Vera, Bárbara; Crespo, Enrique A; Raga, Juan A

    2008-08-01

    There is an increasing interest in parasites of marine mammals of Argentina. Here, we examined several poorly known cetaceans, i.e., 2 spectacled porpoises and 1 Burmeister's porpoise (Phocoenidae), and 1 Gray's beaked whale and 1 Cuvier's beaked whale (Ziphidae); we also updated the parasite information for 1 sperm whale (Physeteridae). These hosts strand only occasionally. We found Anisakis simplex s.l. in 2 spectacled porpoises and the Burmeister's porpoise, and recorded its distribution among the stomach chambers. Anisakis physeteris infected the sperm whale; Corynosoma cetaceum occurred in the duodenal ampulla of the Burmeister's porpoise; Corynosoma australe was found in the posterior-most region of the intestine of 1 spectacled porpoise, while another one had Tetrabothrius sp. in the anal crypts; Corynosoma bullosum and Corynosoma sp. were found in the sperm whale. The only digenean found was Pholeter gastrophilus in the Burmeister's porpoise. Merocercoids of Phyllobothrium delphini were present in the blubber of 1 spectacled porpoise, the sperm whale, and the Gray's beaked whale, while Scolex pleuronectis infected the Gray's beaked whale and 1 spectacled porpoise. No parasites were recovered from the Cuvier's beaked whale. Poor parasite-species assemblages are consistent in marine mammals of Patagonia. Given the conservation status of these hosts, the limited parasitological information gathered is valuable for conservation or management of these hosts in Patagonia.

  20. Outburst floods of glacial lakes in Patagonia: is there an increasing trend?

    NASA Astrophysics Data System (ADS)

    Casassa, Gino; Wendt, Jens; Wendt, Anja; López, Paulina; Schuler, Thomas; Maas, Hans-Gerd; Carrasco, Jorge; Rivera, Andrés.

    2010-05-01

    Glaciers in Patagonia are temperate and many of them are receding at an accelerated rate, with a consequent enlargement of glacial lakes. We will review the occurrence of Glacial Lake Outburst Floods (GLOFs) recorded during the last century in Patagonia (Northern and Southern Patagonia icefields), and analyse them in view of the general warming of 0.5°C affecting the region during the last 40 years. Special attention will be devoted to Lake Cachet 2 (47°12' S, 73°15' W, 422 m a.s.l.) which has experienced 6 GLOF events during the last 2 years: April 6-7 2008, October 7-8 2008, 21-22 December 2008, 5 March 2009, 16 September 2009 and 5-6 January 2010. Lake Cachet 2 has an area of 4 km2, located on the eastern margin of the Northern Patagonia Icefield, being dammed on its southern margin by Colonia Glacier. Prior to the April 2008 event there had been no historical record of catastrophic flooding of this lake. Each event resulted in a flood wave of which travelled down Colonia River to the confluence with Baker River in a period of less than 48 hours, where it reached peak flows of approximately 2,000 m3/s. Here we present airborne and ground explorations carried out in the period 2008-2009 which confirm that the Lake Cachet 2 floods drain through an englacial tunnel under Colonia Glacier for a distance of 8 km, emerging at the front of the glacier. We propose that the lake started draining in 2008 as a result of the weakening of the ice dam produced by long-term thinning of Colonia Glacier. Measurements of the empty lake bed were performed with the CECS airborne laser scanner onboard a helicopter, which show that the maximum water volume of the lake is 200 x 106 m3. Modelling of the flood events has been carried out based on the subglacial flood model of Clarke (2003), showing that a semi-circular subglacial tunnel attaining a maximum dimension of 15 m can evacuate Lake Cachet 2 in approximately 48 hours, with peak flows on the order of 4000 m3/s. Preliminary

  1. Reconnaissance Report for Navigation Improvements (Reduction of Shoaling) at Santa Cruz Harbor Santa Cruz County, California

    DTIC Science & Technology

    1992-05-01

    HARBOR, IT WAS STATED IN THAT RECONNAISSANCE REPORT SIX YEARS AGO THAT, "THE WORK REMAINING TO BE - 4 - I ACCOMPLISHED CONSISTS OF CONSTRUCTING THE SAND...Department of Earth Sciences Santa Cruz, CA 95064 Water Resources Center, UC Davis 2102 Wickson Hall University of California Davis, CA 95616 I Water ...a slope array located southwest of the harbor in just over 20 feet of water , up to 60,000 yards per year of sand is potentially transported in a

  2. Variation resources at UC Santa Cruz.

    PubMed

    Thomas, Daryl J; Trumbower, Heather; Kern, Andrew D; Rhead, Brooke L; Kuhn, Robert M; Haussler, David; Kent, W James

    2007-01-01

    The variation resources within the University of California Santa Cruz Genome Browser include polymorphism data drawn from public collections and analyses of these data, along with their display in the context of other genomic annotations. Primary data from dbSNP is included for many organisms, with added information including genomic alleles and orthologous alleles for closely related organisms. Display filtering and coloring is available by variant type, functional class or other annotations. Annotation of potential errors is highlighted and a genomic alignment of the variant's flanking sequence is displayed. HapMap allele frequencies and linkage disequilibrium (LD) are available for each HapMap population, along with non-human primate alleles. The browsing and analysis tools, downloadable data files and links to documentation and other information can be found at http://genome.ucsc.edu/.

  3. 27 CFR 9.31 - Santa Cruz Mountains.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...—Santa Cruz County”; (7) “Franklin Point Quadrangle, California”; (8) “Half Moon Bay Quadrangle... 400-foot contour line intersect (Half Moon Bay Quadrangle), the boundary line follows Highway...

  4. 27 CFR 9.31 - Santa Cruz Mountains.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...—Santa Cruz County”; (7) “Franklin Point Quadrangle, California”; (8) “Half Moon Bay Quadrangle... 400-foot contour line intersect (Half Moon Bay Quadrangle), the boundary line follows Highway...

  5. 27 CFR 9.31 - Santa Cruz Mountains.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...—Santa Cruz County”; (7) “Franklin Point Quadrangle, California”; (8) “Half Moon Bay Quadrangle... 400-foot contour line intersect (Half Moon Bay Quadrangle), the boundary line follows Highway...

  6. 27 CFR 9.31 - Santa Cruz Mountains.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...—Santa Cruz County”; (7) “Franklin Point Quadrangle, California”; (8) “Half Moon Bay Quadrangle... 400-foot contour line intersect (Half Moon Bay Quadrangle), the boundary line follows Highway...

  7. Thermal structure of proglacial lakes in Patagonia

    NASA Astrophysics Data System (ADS)

    Sugiyama, Shin; Minowa, Masahiro; Sakakibara, Daiki; Skvarca, Pedro; Sawagaki, Takanobu; Ohashi, Yoshihiko; Naito, Nozomu; Chikita, Kazuhisa

    2016-12-01

    Calving glaciers are rapidly retreating in many regions under the influence of ice-water interactions at the glacier front. In contrast to the numerous researches conducted on fjords in front of tidewater glaciers, very few studies have been reported on lakes in which freshwater calving glaciers terminate. To better understand ice-water interactions at the front of freshwater calving glaciers, we measured lakewater temperature, turbidity, and bathymetry near Glaciar Perito Moreno, Upsala, and Viedma, large calving glaciers of the Southern Patagonia Icefield. The thermal structures of these lakes were significantly different from those reported in glacial fjords. There was no indication of upwelling subglacial meltwater; instead, turbid and cold glacial water discharge filled the region near the lake bottom. This was because water density was controlled by suspended sediment concentrations rather than by water temperature. Near-surface wind-driven circulation reaches a depth of 180 m, forming a relatively warm isothermal layer (mean temperature of 5-6°C at Perito Moreno, 3-4°C at Upsala, and 6-7°C at Viedma), which should convey heat energy to the ice-water interface. However, the deeper part of the glacier front is in contact with stratified cold water, implying a limited amount of melting there. In the lake in front of Glaciar Viedma, the region deeper than 120 m was filled entirely with turbid and very cold water at pressure melting temperature. Our results revealed a previously unexplored thermal structure of proglacial lakes in Patagonia, suggesting its importance in the subaqueous melting of freshwater calving glaciers.

  8. Simulation of ground-water flow and potential land subsidence, upper Santa Cruz Basin, Arizona

    USGS Publications Warehouse

    Hanson, R.T.; Benedict, J.F.

    1994-01-01

    A numerical ground-water flow model of the upper Santa Cruz basin in Pinal, Pima, and Santa Cruz Counties was developed to evaluate predevelopment conditions in 1940, ground-water withdrawals for 1940-86, and potential water-level declines and land subsidence for 1987-2024. Simulations of steady-state ground-water conditions indicate 12,900 acre-feet of ground-water inflow, 15,260 acre-feet of outflow, 53,000 acre-feet of pre- development pumpage, 29,840 acre-feet of mountain- front recharge, and 34,020 acre-feet of streamflow infiltration in 1940. Simulations of transient ground-water conditions indicate a total of 6.6 million acre-feet of net pumpage and 3.4 million acre-feet of water removed from aquifer storage for 1941-86. A difference of 1.2 million acre-feet between estimated and net pumpage is attributed to increased recharge from irrigation return flow, mine return flow, and infiltration of sewage effluent. Estimated natural recharge represents 40 percent of pumpage for 1966-86 and averaged 63,860 acre-feet per year for 1940-57 and 76,250 acre-feet per year for 1958-86. The increase in recharge after 1958 was coincident with above- average winter streamflow in the Santa Cruz River for 1959-86. Increased recharge after 1958 and decreased pumpage after 1975 contributed to decreased water-level declines or to recoveries after 1977 in wells near the Santa Cruz River and its tributaries. The results of projection simu- lations indicate that a maximum potential subsi- dence for 1987-2024 ranges from 1.2 feet for an inelastic specific storage of .0001 ft to 12 feet for an inelastic specific storage of .0015 ft. The simulations were made on the basis of pumpage and recharge rates from 1986 and by using a preconso- lidation-stress threshold of 100 feet. A permanent reduction in acquitard storage can range from 1 to 12 percent of the potential loss of 3.9 million acre-feet in aquifer-system storage for 1987-2024.

  9. Proterozoic SCLM domains beneath Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Mundl, Andrea; Ntaflos, Theodoros; Ackerman, Lukas; Bizimis, Michael; Bjerg, Ernesto

    2014-05-01

    Alkali basalt hosted mantle xenoliths from 3 different areas in South Patagonia were studied with regard to their petrography and chemical, as well as their Re-Os and Lu-Hf isotopic compositions. The Pali Aike Volcanic Field (PAVF) located in the very south of Patagonia comprises sample localities Salsa, El Ruido and Potrok Aike. About 300 km north, in the western part of Patagonia, samples were collected at Tres Lagos and further north-east, within and at the edge of the Deseado massif, are sample localities Gobernador Gregores and Don Camilo, respectively. The collected sample suite comprises sp-lherzolites, sp-harzburgites, one sp-dunite and exclusively within PAVF also sp-gt-lherzolites and sp-gt-harzburgites. Textures are mostly protogranular with very few samples showing weak foliation. Whole rock Al2O3 and CaO contents range from 0.63 to 3.54 wt.% and 0.24 to 3.44 wt.%, respectively and exhibit a linear correlation with MgO ranging from 39.2 to 49 wt.%. The more refractory peridotites are represented by samples from the PAVF while samples from the Deseado massif are generally more fertile. Indications for the formation age of SCLM domains can be provided using the Re-Os isotopic system. A suite of 24 modally unmetasomatised sp-lherzolites and sp-harzburgites analyzed for Re-Os isotopic composition reveals Neo- to Paleoproterozoic rhenium depletion ages. Don Camilo and Gobernador Gregores lherzolites indicate a SCLM formation in Mesoproterozoic times (0.9 to 1.3 Ga). Tres Lagos harzburgites reveal slightly older formation ages with a max. TRD of 1.7 Ga. Samples from within the PAVF vary more strongly in 187Os/188Os ratios with Neo- to late Paleoproterozoic TRDs. 3 refractory samples indicate an at least 2.4 Ga old formation age of the SCLM domain underneath PAVF. Hf isotopic data combined with the information obtained from Os isotopic analyses provide new information on potential metasomatic overprints and their probable timing. Negative to low positive

  10. A new genus and species of Planopinae (Xenarthra: Tardigrada) from the Miocene of Santa Cruz Province, Argentina.

    PubMed

    Carlini, Alfredo A; Brandoni, Diego; Dal Molin, Carlos N

    2013-01-01

    Prepoplanops boleadorensis, a new genus and species of Planopinae (Xenarthra, Tardigrada), is described herein. The new taxon is based on a nearly complete specimen recovered from the Cerro Boleadoras Formation (Miocene, Rio Zeballos Group), in northwestern Santa Cruz Province, Argentina. The shape and length of the predentary region of the skull and the length of the diastema of Prepoplanops boleadorensis differ from those present in the species of Planops. The posterolateral opening of the mandibular canal and the position of the posterior margin of the mandibular symphysis differ from those of species of Prepotherium. In addition, Prepoplanops boleadorensis differs from Planops martini in the size of the humeral tuberosities, the development of the deltoid crest, the position of the distal margin of the humeral trochlea, the shape and position of the olecranon, the development of the femoral epicondyles, and the shape of the medial margins of the patellar trochlea and medial condyle. On the other hand, it differs from Prepotherium potens in the shape of the medial margin of the medial condyle. The recognition of Prepoplanops boleadorensis increases the diversity of Planopinae for the Miocene of Patagonia, Argentina.

  11. Glaciers in Patagonia: Controversy and prospects

    NASA Astrophysics Data System (ADS)

    Kargel, J. S.; Alho, P.; Buytaert, W.; Célleri, R.; Cogley, J. G.; Dussaillant, A.; Guido, Z.; Haeberli, W.; Harrison, S.; Leonard, G.; Maxwell, A.; Meier, C.; Poveda, G.; Reid, B.; Reynolds, J.; Rodríguez, C. A. Portocarrero; Romero, H.; Schneider, J.

    2012-05-01

    Lately, glaciers have been subjects of unceasing controversy. Current debate about planned hydroelectric facilities—a US7- to 10-billion megaproject—in a pristine glacierized area of Patagonia, Chile [Romero Toledo et al., 2009; Vince, 2010], has raised anew the matter of how glaciologists and global change experts can contribute their knowledge to civic debates on important issues. There has been greater respect for science in this controversy than in some previous debates over projects that pertain to glaciers, although valid economic motivations again could trump science and drive a solution to the energy supply problem before the associated safety and environmental problems are understood. The connection between glaciers and climate change—both anthropogenic and natural—is fundamental to glaciology and to glaciers' practical importance for water and hydropower resources, agriculture, tourism, mining, natural hazards, ecosystem conservation, and sea level [Buytaert et al., 2010; Glasser et al., 2011]. The conflict between conservation and development can be sharper in glacierized regions than almost anywhere else. Glaciers occur in spectacular natural landscapes, but they also supply prodigious exploitable meltwater.

  12. Scale-dependent analysis of an otter-crustacean system in Argentinean Patagonia

    NASA Astrophysics Data System (ADS)

    Cassini, Marcelo H.; Fasola, Laura; Chehébar, Claudio; MacDonald, David W.

    2009-05-01

    The Southern river otter or ‘huillin’, Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin’s distribution using a scale-dependent analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north-south regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and marine coasts, and of crustaceans using surveys in the water, undigested remains in mink ( Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of population distribution serves as a method for identifying key environmental factors for species for which the use of long-term demographies is unfeasible.

  13. The Border Environmental Health Initiative: Investigation of the Transboundary Santa Cruz Watershed

    NASA Astrophysics Data System (ADS)

    Norman, L. M.; Callegary, J. B.; van Riper, C.; Gray, F.; Paretti, N.; Villarreal, M.

    2009-12-01

    In the borderland region of the desert southwest, human health and the ecosystems upon which humans rely largely depend on the quality, quantity, and distribution of water resources. In the Santa Cruz River Watershed (SCW), located in the Arizona and Sonora, Mexico border region, surface water is scarce and unreliable, and, during much of the year, is composed of effluent from the local wastewater treatment plant. This makes groundwater the preferred and, consequently, primary source for industrial, agricultural, and domestic use. USGS scientists are using an integrative approach, incorporating the expertise of the Geography, Water, Biology, and Geology disciplines to identify risks to water resources in the SCW, and the potential for impacts to riparian ecosystems and ultimately, human health. This includes tracking organic and inorganic contaminants and their effects from sources to sinks in sediment, water, plants, and animals. Existing ground- and surface-water models will be used and modified to assess contaminant and sediment transport. Water quality, sediment, aquatic macro invertebrates, aquatic plants (macrophytes), algae, riparian grasses, fish, and birds will be sampled at five locations along the Santa Cruz River. Field sampling data will be obtained at sites that coincide with historical sampling programs. Site locations include (i.) the Santa Cruz River headwaters (which should be unaffected by downstream contaminant sources), (ii.) a tributary routed through an abandoned mining district, (iii.) a binational tributary that flows though highly urbanized areas, (iv.) effluent from the local wastewater treatment plant, and (v.) the downstream confluence of the first four sources. The Soil and Water Assessment Tool (SWAT) model will be used in combination with field data to identify key sources of contaminants, contributing areas, and transport modes to track their movement to surface waters. These data will be used together to test relationships between

  14. Rivers

    USGS Publications Warehouse

    Leopold, Luna Bergere

    1962-01-01

    Rivers are both the means and the routes by which the products of continental weathering are carried to the oceans of the world. Except in the most arid areas more water falls as precipitation than is lost by evaporation and transpiration from the land surface to the atmosphere. Thus there is an excess of water, which must flow to the ocean. Rivers, then, are the routes by which this excess water flows to the ultimate base level. The excess of precipitation over evaporation and transpiration provides the flow of rivers and springs, recharges ground-water storage, and is the supply from which man draws water for his needs.

  15. Late Holocene environmental changes in a mesotidal estuary from Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Espinosa, Marcela; Escandell, Alejandra; Velez Agudelo, Camilo

    2016-04-01

    Two sediment records from the lower valley of Negro River, Patagonia, Argentina (41°01´S; 62°47'W) spanning for the last 2000 cal yrs BP were analyzed according to diatoms and sediments contents. The river originates at the junction of the Neuquén and the Limay Rivers, Northern Patagonia, and discharges more than 1000 m3/s to the South Atlantic Ocean. Mesotidal conditions dominate at the inlet (2.95 m) affecting the lower valley (about 20 km) where salinity decreases drastically in the last 2 km. Fossil diatom assemblages and grain size were studied from two cores located at 1.5 km (Villarino site) and 12 km (Criadero site) from the inlet. Samples for modern diatom analyses were collected from the littoral zone at eleven sites along the river. Physical and chemical variables were quantified representing the maximum heterogeneity along the aquatic environment. Turbidity, salinity, conductivity, pH and temperature data were obtained in situ during summer and winter. In addition, a surface sediment sample was taken for grain size analysis and organic matter content, and water samples were taken to analyze nutrients and major ions following standard methods. The diatom content of modern sediment samples were studied in order to achieve ecological information useful as modern analogous for Patagonian rivers. Diatom zones were characterized by constrained incremental sum of squares cluster analysis (single linkage, Euclidean distance) in the fossil sequences. Fossil and modern diatom assemblages were compared with Detrended Correspondence Analysis (DCA). A total of 77 samples (modern and fossils) were analyzed and more than 200 taxa were identified. Diatom assemblages showed distinct abundance patterns in relation to salinity with a shift from communities dominated by marine/brackish taxa in lower sites to communities dominated by freshwater taxa in the middle and upper course of the river. The record of Criadero core (12 km from the inlet) began 2000 cal yrs BP with

  16. Earthquake site response in Santa Cruz, California

    USGS Publications Warehouse

    Carver, D.; Hartzell, S.H.

    1996-01-01

    Aftershocks of the 1989 Loma Prieta, California, earthquake are used to estimate site response in a 12-km2 area centered on downtown Santa Cruz. A total of 258 S-wave records from 36 aftershocks recorded at 33 sites are used in a linear inversion for site-response spectra. The inversion scheme takes advantage of the redundancy of the large data set for which several aftershocks are recorded at each site. The scheme decomposes the observed spectra into source, path, and site terms. The path term is specified before the inversion. The undetermined degree of freedom in the decomposition into source and site spectra is removed by specifying the site-response factor to be approximately 1.0 at two sites on crystalline bedrock. The S-wave site responses correlate well with the surficial geology and observed damage pattern of the mainshock. The site-response spectra of the floodplain sites, which include the heavily damaged downtown area, exhibit significant peaks. The largest peaks are between 1 and 4 Hz. Five floodplain sites have amplification factors of 10 or greater. Most of the floodplain site-response spectra also have a smaller secondary peak between 6 and 8 Hz. Residential areas built on marine terraces above the flood-plain experienced much less severe damage. Site-response spectra for these areas also have their largest peaks between 1 and 4 Hz, but the amplification is generally below 6. Several of these sites also have a secondary peak between 6 and 8 Hz. The response peaks seen at nearly all sites between 1 and 4 Hz are probably caused by the natural resonance of the sedimentary rock column. The higher amplifications at floodplain sites may be caused by surface waves generated at the basin margins. The secondary peak between 6 and 8 Hz at many sites may be a harmonic of the 1- to 4-Hz peaks. We used waveforms from a seven-station approximately linear array located on the floodplain to calculate the apparent velocity and azimuth of propagation of coherent

  17. 75 FR 44806 - Ellicott Slough National Wildlife Refuge, Santa Cruz County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... Fish and Wildlife Service Ellicott Slough National Wildlife Refuge, Santa Cruz County, CA AGENCY: Fish... Refuge, located in Santa Cruz County, California, consists of three noncontiguous units within and... Santa Cruz long-toed salamander by supporting 2 of the 20 known breeding populations of the...

  18. South american geochronology: radiometric time scale for middle to late tertiary mammal-bearing horizons in patagonia.

    PubMed

    Marshall, L G; Pascual, R; Curtis, G H; Drake, R E

    1977-03-25

    Radiometric (potassium-argon) age determinations for basalts and tuffs associated with middle to late Tertiary mammal-bearing horizons in Patagonia, southern Argentina, permit refinement of boundaries and hiatuses between beds of Deseadan (early Oligocene) through Friasian (middle to late Miocene) age. At two localities beds of Deseadan age are overlain by basalts, which gave dates of 33.6 and 35.4 million years ago; 34.0 million years ago is tentatively accepted as a terminal date for known Deseadan. At several localities beds of Colhuehuapian age are underlain by basalts, which gave dates ranging from 28.8 to 24.3 million years ago; 25.0 million years is tentatively taken as a basal age for known Colhuehuapian. The paleontological hiatus between known Deseadan and known Colhuehuapian is thus in the order of 9.0 million years. Two tuffs from the Santa Cruz Formation (Santacrucian) gave ages of 21.7 and 18.5 million years. Plagioclase and biotite concentrates of an ignimbrite from the Collón Curá Formation (Friasian) gave ages ranging from 15.4 to 14.0 million years.

  19. Uplift of quaternary shorelines in eastern Patagonia: Darwin revisited

    NASA Astrophysics Data System (ADS)

    Pedoja, Kevin; Regard, Vincent; Husson, Laurent; Martinod, Joseph; Guillaume, Benjamin; Fucks, Enrique; Iglesias, Maximiliano; Weill, Pierre

    2011-04-01

    During his journey on the Beagle, Darwin observed the uniformity in the elevation of coastal Eastern Patagonia along more than 2000 km. More than one century later, the sequences of Quaternary shorelines of eastern Patagonia have been described and their deposits dated but not yet interpreted in terms of geodynamics. Consequently, we i) mapped the repartition of the Quaternary coastal sequences in Argentinean Patagonia, ii) secured accurate altitudes of shoreline angles associated with erosional morphologies (i.e. marine terraces and notches), iii) took into account previous chrono-stratigraphical interpretations in order to calculate mean uplift rates since ~ 440 ka (MIS 11) and proposed age ranges for the higher and older features (up to ~ 180 m), and iv) focused on the Last Interglacial Maximum terrace (MIS 5e) as the best constrained marine terrace (in terms of age and altitude) in order to use it as a tectonic benchmark to quantify uplift rates along the entire passive margin of Eastern South America. Our results show that the eastern Patagonia uplift is constant through time and twice the uplift of the rest of the South American margin. We suggest that the enhanced uplift along the eastern Patagonian coast that interested Darwin during his journey around South America on the Beagle could originate from the subduction of the Chile ridge and the associated dynamic uplift.

  20. Perspective view of shaded relief, color as height, Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This perspective view of Patagonia, Argentina shows a spectacular landscape formed by volcanoes, rivers, and wind. The area is located just east of the narrow range of the Andes Mountains, about 100 kilometers (62 miles) east of the border with Chile. Interesting features include basalt-capped mesas (top) and young volcanic cones (left foreground). Geologists will use SRTM topographic data to study the interaction of volcanic, climatic and erosional processes.

    This shaded relief perspective view was generated using topographic data from the Shuttle Radar Topography Mission. A computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. On flatter surfaces, the pattern of light and shadows can reveal subtle features in the terrain. Colors show the elevation as measured by SRTM. Colors range from blue at the lowest elevations to white at the highest elevations. This image contains about 1100 meters (3600 feet) of total relief. To emphasize subtle differences in topography, the relief is exaggerated by a factor of 5.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI)space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC

  1. Seafloor off Lighthouse Point Park, Santa Cruz, California

    USGS Publications Warehouse

    Storlazzi, Curt D.; Golden, Nadine E.; Gibbons, Helen

    2013-01-01

    The seafloor off Lighthouse Point Park, Santa Cruz, California, is extremely varied, with sandy flats, boulder fields, faults, and complex bedrock ridges. These ridges support rich marine ecosystems; some of them form the "reefs" that produce world-class surf breaks. Colors indicate seafloor depth, from red-orange (about 2 meters or 7 feet) to magenta (25 meters or 82 feet).

  2. Seafloor off Natural Bridges State Beach, Santa Cruz, California

    USGS Publications Warehouse

    Storlazzi, Curt D.; Golden, Nadine E.; Gibbons, Helen

    2013-01-01

    The seafloor off Natural Bridges State Beach, Santa Cruz, California, is extremely varied, with sandy flats, boulder fields, faults, and complex bedrock ridges. These ridges support rich marine ecosystems; some of them form the "reefs" that produce world-class surf breaks. Colors indicate seafloor depth, from red-orange (about 2 meters or 7 feet) to magenta (25 meters or 82 feet).

  3. Seafloor off Pleasure Point, Santa Cruz County, California

    USGS Publications Warehouse

    Storlazzi, Curt D.; Golden, Nadine E.; Gibbons, Helen

    2013-01-01

    The seafloor off Pleasure Point, Santa Cruz County, California, is extremely varied, with sandy flats, boulder fields, faults, and complex bedrock ridges. These ridges support rich marine ecosystems; some of them form the "reefs" that produce world-class surf breaks. Colors indicate seafloor depth, from red-orange (about 2 meters or 7 feet) to magenta (25 meters or 82 feet)

  4. Temporal variability of mineral aerosol in the South Patagonia

    NASA Astrophysics Data System (ADS)

    Qu, Zihan; Losno, Rémi; Journet, Émilie; Salvado, Jacobo; Bulnes, Daniela; Monna, Fabrice; Quisefit, Jean-Paul; Heimburger, Alexie; Ristori, Pablo; Quel, Eduardo Jaime; Balkanski, Yves

    2015-04-01

    Patagonia (South America) is a major atmospheric mineral dust source in the South Hemisphere. The input of Patagonian dust plays a critical role in the biogeochemistry of Southern Ocean. From November 2011 to August 2014, aerosol samples were continuously collected on a weekly basis in Río Gallegos (69.32° W, 51.60° S), by the south Patagonia east coast. This three-year measurement is the first long term time series of mineral dust concentrations obtained in the sub-Antarctic region. Backward trajectories by HYSPLIT model showed that up to 90% of air mass arrived at Río Gallegos originated from the west side (between NNW and SSW) of sampling site. Amounts of Al, Si and Fe were determined by XRF analysis. The compositions of the three elements remained stable during the three years samplings. Weekly dust concentrations measured in South Patagonia varied from 0.08 to 3.67 μg.m-3 and reveals a strong seasonal variation pattern. Average winter dust concentrations could decrease down to five times lower than in other seasons. Higher wind speeds unexpectedly did not result in higher dust concentrations. However, variations of the temperature and the air relative humidity well correlated with the dust concentration variation. This suggests that surface soil moisture changes are the primary regulating factor of dust concentration variation in Patagonia. Land frozen effect was potentially another factor resulting low level of dust concentration in winter. These results permit the improvement of atmospheric dust modelling in the South Hemisphere. This work is in SOLAS scope, and is supported by French project 'Dust From Patagonia' (CNRS-INSU, LEFE/CHAT) and France-Argentina cooperation program 'ASAR' (ECOS-Sud).

  5. Metasomatic processes within the fertile lithospheric Mantle beneath Don Camilo, Santa Cruz, Argentina

    NASA Astrophysics Data System (ADS)

    Ntaflos, Th.; Mundl, A.; Bjerg, E. A.; Tschegg, C.; Kosler, J.

    2009-04-01

    formed from residual melts. In contrast, clinopyroxene from mantle dunites enriched LREE (10 x PM) and LILE suggesting that the metasomatic agent was fluid-rich silicate melt. Calculated equilibrium P-T conditions cover a wide range from 800 to 1100 °C. Considering the crustal thickness in the area being around 35 km, a pressure between 12 and 17 kbar could be assumed as reasonable, indicating that these xenoliths were extracted from shallow depths of 40 to 60 km. Model calculations have shown that the lithospheric Mantle beneath Don Camilo, in Santa Cruz province is fertile and that spinel peridotites experienced low degrees of partial melting (2-8% batch melting in the spinel peridotite field). The metasomatic agent was a fluid-rich silicate melt of alkalibasaltic composition, presumably similar to this, which affected the Cerro Clark xenoliths north of Don Camilo locality. Don Camilo mantle xenoliths, like Tres Lagos, Cerro Redondo and Gobernador Gregores, does not show evidence for interaction of the lithospheric Mantle in southern Patagonia with subduction related components.

  6. Geochemistry of Isla Santa Cruz, Galapagos Archipelago, Ecuador

    NASA Astrophysics Data System (ADS)

    Wilson, E. L.; Schwartz, D. M.; Van Kirk, R.; Harpp, K.

    2012-12-01

    The geochemistry of Galapagos volcanoes extends to more depleted signatures than most hotspots, and do not appear to follow a classical tholeiitic to alkalic evolutionary sequence (i.e., Hawaiian Islands). Thus far, no such predictable sequence has been identified for Galapagos volcanoes. Isla Santa Cruz is one of the oldest volcanoes in the archipelago. Bow (1979) identified 3 volcanic stages: the Platform Series, the Shield Series, and the Shield-Modifying stage. The Platform Series defines a liquid line of descent that differs from the one shared by the Shield and Shield-Modifying units, which are genetically related to each other. Within the Shield and Shield-Modifying lavas, K2O/TiO2 ratios reveal three distinct compositional sub-groups: 1) a MORB-like, low-K suite (<0.10); 2) a tholeiitic suite (0.10-0.25); and 3) an alkaline suite (>0.25). These 3 sub-groups are geographically distributed across the island; the low-K suite is only in the north, whereas the alkaline suite constitutes the center highlands and the tholeiitic suite is on the eastern and northern flanks. Variations in La/Sm and Sm/Yb indicate that the magmas supplying the Shield and Shield-Modifying units were generated over a wide range of melting conditions: the alkaline suite melts were generated at the greatest depths and from the smallest melt fraction of the three suites, whereas the low-K suite originates from shallower, greater extents of melting; the tholeiitic lavas were generated at depths intermediate between the other 2 sub-groups. None of the lavas from Santa Cruz resemble material erupted at Fernandina volcano, the presumed center of the plume; radiogenic isotope ratios from previous research indicate that all Santa Cruz lavas are significantly more depleted than western Galapagos lavas. The ~1.2 Ma Platform Series is the most enriched of the Santa Cruz units. The Shield and Shield-Modifying lavas are all shifted towards more depleted signatures, approaching those of MORB, in terms

  7. A Water Resources Management Model to Evaluate Climate Change Impacts in North-Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Bucciarelli, L. F.; Losano, F. T.; Marizza, M.; Cello, P.; Forni, L.; Young, C. A.; Girardin, L. O.; Nadal, G.; Lallana, F.; Godoy, S.; Vallejos, R.

    2014-12-01

    Most recently developed climate scenarios indicate a potential future increase in water stress in the region of Comahue, located in the North-Patagonia, Argentina. This region covers about 140,000 km2 where the Limay River and the Neuquén River converge into the Negro River, constituting the largest integrated basins in Argentina providing various uses of water resources: a) hydropower generation, contributing 15% of the national electricity market; b) fruit-horticultural products for local markets and export; c) human and industrial water supply; d) mining and oil exploitation, including Vaca Muerta, second world largest reserves of shale gas and fourth world largest reserves of shale-oil. The span of multiple jurisdictions and the convergence of various uses of water resources are a challenge for integrated understanding of economically and politically driven resource use activities on the natural system. The impacts of climate change on the system could lead to water resource conflicts between the different political actors and stakeholders. This paper presents the results of a hydrological simulation of the Limay river and Neuquén river basins using WEAP (Water Evaluation and Planning) considering the operation of artificial reservoirs located downstream at a monthly time step. This study aims to support policy makers via integrated tools for water-energy planning under climate uncertainties, and to facilitate the formulation of water policy-related actions for future water stress adaptation. The value of the integrated resource use model is that it can support local policy makers understand the implications of resource use trade-offs under a changing climate: 1) water availability to meet future growing demand for irrigated areas; 2) water supply for hydropower production; 3) increasing demand of water for mining and extraction of unconventional oil; 4) potential resource use conflicts and impacts on vulnerable populations.

  8. Multi-gauge Calibration for modeling the Semi-Arid Santa Cruz Watershed in Arizona-Mexico Border Area Using SWAT

    USGS Publications Warehouse

    Niraula, Rewati; Norman, Laura A.; Meixner, Thomas; Callegary, James B.

    2012-01-01

    In most watershed-modeling studies, flow is calibrated at one monitoring site, usually at the watershed outlet. Like many arid and semi-arid watersheds, the main reach of the Santa Cruz watershed, located on the Arizona-Mexico border, is discontinuous for most of the year except during large flood events, and therefore the flow characteristics at the outlet do not represent the entire watershed. Calibration is required at multiple locations along the Santa Cruz River to improve model reliability. The objective of this study was to best portray surface water flow in this semiarid watershed and evaluate the effect of multi-gage calibration on flow predictions. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated at seven monitoring stations, which improved model performance and increased the reliability of flow, in the Santa Cruz watershed. The most sensitive parameters to affect flow were found to be curve number (CN2), soil evaporation and compensation coefficient (ESCO), threshold water depth in shallow aquifer for return flow to occur (GWQMN), base flow alpha factor (Alpha_Bf), and effective hydraulic conductivity of the soil layer (Ch_K2). In comparison, when the model was established with a single calibration at the watershed outlet, flow predictions at other monitoring gages were inaccurate. This study emphasizes the importance of multi-gage calibration to develop a reliable watershed model in arid and semiarid environments. The developed model, with further calibration of water quality parameters will be an integral part of the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM), an online decision support tool, to assess the impacts of climate change and urban growth in the Santa Cruz watershed.

  9. Mycobacterium fortuitum Cruz from the tropical fish Hyphessobrycon innesi

    USGS Publications Warehouse

    Ross, A.J.; Brancato, F.P.

    1959-01-01

    Mycobacterium fortuitum, a rapid-growing, acid-fast bacillus, isolated from a cold abscess of human origin was described by Cruz (1938). Gordon and Smith (1955), in a taxonomic study embracing a group of acid-fast bacteria capable of relatively rapid growth on ordinary media, classified a number of cultures in their collection as M. fortuitum Cruz. In this group were strains isolated from human beings, cattle, soil, and cold-blooded animals including marine fishes. The present study was undertaken to determine the identity of a rapid-growing, acid-fast bacillus isolated at the New York Aquarium from lesions present in a population of freshwater tropical fishes commonly known as the Neon Tetra (Hyphessobrycon innesi). The symptomatology and pathology of this disease have been described by Nigrelli (1953).

  10. Soil chemistry and mineralogy of the Santa Cruz coastal terraces

    USGS Publications Warehouse

    Pinney, Colin; Aniku, Jacob; Burke, Raymond; Harden, Jennifer; Singer, Michael; Munster, Jennie

    2002-01-01

    Marine terraces in the central coast of California provide an opportunity to study a soil chronosequence in which similar materials (beach deposits) have been weathered under similar slope, climatic, and vegetation conditions during the Quaternary. The terraces between Santa Cruz and Año Nuevo, California, have been studied for decades and are thought to be one of the best example of marine terraces in California {Lawson (1893), Wilson (1907); Branner and others (1909), Rode (1930) Page and Holmes (1945), Alexander (1953), Bradley (1956, 1957, 1958, and 1965), Bradley and Addicott (1968), Clark (1966 and 1970), Jahns and Hamilton (1971), Lajoie and others (1972), Bradley and Griggs (1976). Hanks and others (1986), Aniku (1986), Fine and others (1988), Anderson (1990 and 1994), and Rosenbloom and Anderson (1994).} Here we report morphological, chemical, physical, and mineralogical data for the soils that were formed in deposits on the Santa Cruz marine terraces in order to examine soil characteristics as a function of increasing terrace age.

  11. The impact of Chilean migration on employment in Patagonia.

    PubMed

    Cariola Sanz, L

    1989-06-01

    This paper discusses the employment situation of Chilean migrant workers, their impact on labor markets in Patagonia, Argentina, and the government's past and projected responses to this phenomenon. In 1980, Chilean inhabitants of patagonia comprised 11% of the area's population. Chilean migration to patagonia was closely linked to economic activities that began to flourish in the 20th century, such as livestock raising, fruit and vegetable cultivation, and mining for coal and petroleum. No Chilean migrants work in a wide range of sectors. In Patagonia's southern provinces availability and ability to withstand rigorous climate conditions are the main factors which account for the prevalence of Chilean manpower. Chilean migrants do not in general displace local manpower. Legislation and the permeability of the border ensure that most workers enter the country as tourists. Clandestine migration is not an issue. Illegal migrants have provoked negative reactions for several reasons: 1) they comprise a marginal population without formal citizenship; 2) being employed as clandestine workers, they pay no social security, nor do their employers; 3) being illegal, they are obliged to accept lower wages and inferior working conditions which creates unfair competition within labor markets; and 4) as a result of these conditions, xenophobic and endophobic attitudes in relations with Argentine nationalists are reinforced. The government has attempted to solve these problems through various measures. Beginning in 1934, most foreigners entered Argentina with a tourist visa, becoming illegal when they stayed beyond authorized limits. Several measures over the years provided amnesty to illegal migrants. Currently, the law promotes immigration, monitors the admission of foreigners to the country and stipulates their rights and obligations. The law lists 115 articles on immigration promotion and on regulation of the movements of foreigners. Because of the present economic crisis in

  12. Late Quaternary slip on the Santa Cruz Island fault, California

    USGS Publications Warehouse

    Pinter, N.; Lueddecke, S.B.; Keller, E.A.; Simmons, K.R.

    1998-01-01

    The style, timing, and pattern of slip on the Santa Cruz Island fault were investigated by trenching the fault and by analysis of offset late Quaternary landforms. A trench excavated across the fault at Christi Beach, on the western coast of the island, exposed deformation of latest Pleistocene to Holocene sediments and pre-Quaternary rocks, recording repeated large-magnitude rupture events. The most recent earthquake at this site occurred ca. 5 ka. Coastal terraces preserved on western Santa Cruz Island have been dated using the uranium-series technique and by extrapolation using terrace elevations and the eustatic record. Offset of terraces and other landforms indicates that the Santa Cruz Island fault is predominantly left lateral, having a horizontal slip rate of not more than 1.1 mm/yr and probably about 0.8 mm/yr. The fault also has a smaller reverse component, slipping at a rate of between 0.1 and 0.2 mm/yr. Combined with measurements of slip per event, this information suggests a long-term average recurrence interval of at least 2.7 k.y. and probably 4-5 k.y., and average earthquake magnitudes of Mw 7.2-7.5. Sense of slip, recurrence interval, and earthquake magnitudes calculated here for the Santa Cruz Island fault are very similar to recent results for other faults along the southern margin of the western Transverse Range, including the Malibu Coast fault, the Santa Monica fault, the Hollywood fault, and the Raymond fault, supporting the contention that these faults constitute a continuous and linked fault system, which is characterized by large but relatively infrequent earthquakes.

  13. Urbanisation of yellow fever in Santa Cruz, Bolivia.

    PubMed

    Van der Stuyft, P; Gianella, A; Pirard, M; Cespedes, J; Lora, J; Peredo, C; Pelegrino, J L; Vorndam, V; Boelaert, M

    1999-05-08

    Until recently, urban yellow fever had not been reported from the Americas since 1954, but jungle yellow fever increasingly affects forest dwellers in Bolivia, Brazil, Colombia, Ecuador, and Peru. The reinvasion by Aedes aegypti of cities in the Americas now threatens to urbanize yellow fever. After yellow fever infection was identified in a resident of Santa Cruz, Bolivia, in December 1997, all subsequent suspected cases were investigated. Active surveillance of yellow fever was introduced in the Santa Cruz area, with hospitals and selected urban and rural health centers reporting all suspected cases. Patients were serologically screened for yellow fever, dengue, hepatitis A and B, and leptospirosis; clinical and epidemiological data were collected from patients' records and through interviews; and a population-based serosurvey was conducted in the neighborhood of one case. Between December 1997 and June 1998, symptomatic yellow fever infection was confirmed in 6 residents of Santa Cruz, of whom 5 died. 5 lived in the southern sector of the city. 2 cases did not leave the city during their incubation period, and 1 had visited only an area in which sylvatic transmission was deemed impossible. Of the 281 people covered in the serosurvey, 16 (6%) were positive for IgM antibody to yellow fever. Among 5 people for whom that result could not be explained by recent vaccination, there were 2 pairs of neighbors. This instance of urban yellow fever transmission was limited in both time and space.

  14. Historical review of clinical vaccine studies at Oswaldo Cruz Institute and Oswaldo Cruz Foundation - technological development issues

    PubMed Central

    Martins, Reinaldo de Menezes; Possas, Cristina de Albuquerque; Homma, Akira

    2015-01-01

    This paper presents, from the perspective of technological development and production, the results of an investigation examining 61 clinical studies with vaccines conducted in Brazil between 1938-2013, with the participation of the Oswaldo Cruz Institute (IOC) and the Oswaldo Cruz Foundation (Fiocruz). These studies have been identified and reviewed according to criteria, such as the kind of vaccine (viral, bacterial, parasitic), their rationale, design and methodological strategies. The results indicate that IOC and Fiocruz have accumulated along this time significant knowledge and experience for the performance of studies in all clinical phases and are prepared for the development of new vaccines products and processes. We recommend national policy strategies to overcome existing regulatory and financing constraints. PMID:25742271

  15. Diatom diversity and paleoenvironmental changes in Laguna Potrok Aike, Patagonia: the ~ 50 kyr PASADO sediment record

    NASA Astrophysics Data System (ADS)

    Recasens, C.; Ariztegui, D.; Maidana, N. I.

    2012-12-01

    Laguna Potrok Aike is a maar lake located in the southernmost Argentinean Patagonia, in the province of Santa Cruz. Being one of the few permanent lakes in the area, it provides an exceptional and continuous sedimentary record. The sediment cores from Laguna Potrok Aike, obtained in the framework of the ICDP-sponsored project PASADO (Potrok Aike Maar Lake Sediment Archive Drilling Program), were sampled for diatom analysis in order to reconstruct a continuous history of hydrological and climatic changes since the Late Pleistocene. Diatoms are widely used to characterize and often quantify the impact of past environmental changes in aquatic systems. We use variations in diatom concentration and in their dominant assemblages, combined with other proxies, to track these changes. Diatom assemblages were analyzed on the composite core 5022-2CP with a multi-centennial time resolution. The total composite profile length of 106.09 mcd (meters composite depth) was reduced to 45.80 m cd-ec (event-corrected composite profile) of pelagic deposits once gaps, reworked sections, and tephra deposits were removed. This continuous deposit spans the last ca. 51.2 cal. ka BP. Previous diatomological analysis from the core catcher samples of core 5022-1D, allowed us to determine the dominant diatom assemblages in this lake and select the sections where higher temporal resolution was needed. Over 200 species, varieties and forms were identified in the sediment record, including numerous endemic species and others which can be new to science. Among these, a new species has been described: Cymbella gravida sp. nov. Recasens and Maidana. The quantitative analysis of the sediment record reveals diatom abundances reaching 460 million valves per gram of dry sediment, with substantial fluctuations through time. Variations in the abundance and species distribution point toward lake level variations, changes in nutrient input or even periods of ice-cover in the lake. The top meters of the record

  16. Paleoparasitological finding of eggs of nematodes in rodent coprolites dated at the early Holocene from the archaeological site Cerro Casa de Piedra 7, Santa Cruz, Argentina.

    PubMed

    Sardella, N H; Fugassa, M H

    2011-12-01

    The aim of the present study was to examine the parasite remains present in rodent coprolites collected from the archaeological site Cerro Casa de Piedra 7 (CCP7), located in the Perito Moreno National Park (47°57'S, 72°05'W), Santa Cruz Province, Argentina. Eight coprolites obtained from the layer 17, dated at 10,620 ± 40 to 9,390 ± 40 yr B.P., were examined for parasites. Feces were processed whole, rehydrated, homogenized, subjected to spontaneous sedimentation, and examined via light microscopy. Eggs of parasites were measured and photographed. Seven of 8 coprolites possessed 199 eggs of 2, probably new, species of nematodes, including 43 eggs of Heteroxynema sp. Hall, 1916 (Cavioxyura sp. Quentin, 1975) (Oxyurida, Heteroxynematidae), and 156 eggs of Trichuris sp. Roederer, 1761 (Trichinellida, Trichuridae). Heteroxynema sp. is cited for the first time from ancient material worldwide. The finding of Trichuris spp. in both rodents and other host samples from the area under study is indicative of the stability of the biological and environmental conditions for this nematode genus to establish in the Patagonian Early Holocene. The rodent host was assigned to an unknown species of Caviomorpha (Hystricognathi) that lived during the Pleistocenic transition in Patagonia.

  17. Relationship between Bajo Pobre and Chon Aike formations (Deseado Massif, Patagonia, Argentina):a melt inclusions study

    NASA Astrophysics Data System (ADS)

    Busà, T.; Bellieni, G.; Fernandez, R.; Hecheveste, H.; Piccirillo, E. M.

    2003-04-01

    The Deseado Massif covers the centre-east of the Santa Cruz Province, in the extra-Andean Patagonia. Although the Deseado Massif is mainly composed of silicic volcanic rocks (Chon Aike Formation, CA; 151.5 ±0.5 - 177.8 ±0.4 Ma), mafic and intermediate volcanites (Bajo Pobre Formation, BP; 152.7 ±0.5 and 164 ±0.3 Ma) outcrop largely in the central part of the Massif. In this paper quarz-trapped melt inclusions (rhyolitic in composition) from selected samples of the BP and the CA are analysed. On the basis of major elements content, for BP the sequence from andesite (BP whole rock) to ryholite (trapped as inclusions in quartz) can be modelled by simple fractional crystallisation of ortho- and clinopyroxene, plagioclase, quartz and apatite. As regards trace elements, a good calculated/measured ratio (around 1 ±0.2) is obtained assuming only a relatively high apatite fractionation. Since the apatite fractionation amount is not acceptable for major elements, the evolution of BP Formation cannot be modelled by a simple process of fractional crystallisation, and a contamination process probably occurred. The sequence from BP to CA cannot be modelled by fractional crystallisation. 30% batch melting of BP andesite (BP whole rock) produces a magma from which the CA ryholites (trapped as inclusions in quartz) can be obtained by Rayleigh fractional crystallisation of ortho- and clinopyroxene, plagioclase, magnetite, quartz, apatite and small amounts of zircon and minor allanite. Since the latter one was not observed in the analysed sample, a contamination process during magma evolution cannot be completely excluded. Finally, on the basis of the different trace elements concentration (Nb anomaly, different content in LILE, B/Be and B/Nb), it is possible to suppose that, at the time of the BP and CA emplacement, a changing in the tectonic setting, from subduction to a lithospheric extension, was active.

  18. Origin and evolution of the Laguna Potrok Aike maar (Southern Patagonia, Argentina) as revealed by seismic data

    NASA Astrophysics Data System (ADS)

    Gebhardt, C.; de Batist, M. A.; Niessen, F.; Anselmetti, F.; Ariztegui, D.; Haberzettl, T.; Ohlendorf, C.; Zolitschka, B.

    2009-12-01

    Seismic reflection and refraction data provide insights into the sedimentary infill and the underlying volcanic structure of Laguna Potrok Aike, a maar lake situated in the Pali Aike Volcanic Field, Southern Patagonia. The lake has a diameter of ~3.5 km, a maximum water depth of ~100 m and a presumed age of ~770 ka. Its sedimentary regime is influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Multiproxy environmental reconstructions of the last 16 ka document that this terminal lake is highly sensitive to climate change. Laguna Potrok Aike has recently become a major focus of the International Continental Scientific Drilling Program and was drilled down to 100 m below lake floor in late 2008 within the PASADO project. The sediments are likely to contain a continental record spanning the last ca. 80 kyrs unique in the South American realm. Seismic reflection data show relatively undisturbed, stratified lacustrine sediments at least in the upper ~100 m of the sedimentary infill but are obscured possibly by gas and/or coarser material in larger areas. A model calculated from seismic refraction data reveals a funnel-shaped structure embedded in the sandstone rocks of the surrounding Santa Cruz Formation. This funnel structure is filled by lacustrine sediments of up to 370 m in thickness. These can be separated into two distinct subunits with low acoustic velocities of 1500-1800 m s-1 in the upper subunit pointing at unconsolidated lacustrine muds, and enhanced velocities of 2000-2350 m s-1 in the lower subunit. Below these lacustrine sediments, a unit of probably volcanoclastic origin is observed (>2400 m s-1). This sedimentary succession is well comparable to other well-studied sequences (e.g. Messel and Baruth maars, Germany), confirming phreatomagmatic maar explosions as the origin of Laguna Potrok Aike.

  19. Space Radar Image of Santa Cruz Island, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This space radar image shows the rugged topography of Santa Cruz Island, part of the Channel Islands National Park in the Pacific Ocean off the coast of Santa Barbara and Ventura, Calif. Santa Cruz, the largest island of the national park, is host to hundreds of species of plants, animals and birds, at least eight of which are known nowhere else in the world. The island is bisected by the Santa Cruz Island fault, which appears as a prominent line running from the upper left to the lower right in this image. The fault is part of the Transverse Range fault system, which extends eastward from this area across Los Angeles to near Palm Springs, Calif. Color variations in this image are related to the different types of vegetation and soils at the surface. For example, grass-covered coastal lowlands appear gold, while chaparral and other scrub areas appear pink and blue. The image is 35 kilometers by 32 kilometers (22 miles by 20 miles) and is centered at 33.8 degrees north latitude, 119.6 degrees west longitude. North is toward upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is C-band, horizontally transmitted and vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 10, 1994, onboard the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

  20. Prevalence of Diabetes on Santa Cruz Island in Galapagos Archipelago

    PubMed Central

    Chowdhury, Tahseen

    2015-01-01

    This was an observational study offering a screening program for diabetes in a health clinic in Puerto Ayora town on Santa Cruz Island to determine the prevalence of this disorder and identify those at risk. A 1-month screening program was undertaken. Of 141 patients screened, 85% of men and 83% of women were overweight or obese; 16 (11%) had suspected undiagnosed diabetes and 22 (16%) were at high risk of developing diabetes. This is the first reported study of glucose intolerance prevalence in Galapagos. Urgent education and prevention programs are required to address this public health problem. PMID:26086607

  1. High plant diversity in Eocene South America: evidence from Patagonia.

    PubMed

    Wilf, Peter; Cúneo, N Rubén; Johnson, Kirk R; Hicks, Jason F; Wing, Scott L; Obradovich, John D

    2003-04-04

    Tropical South America has the highest plant diversity of any region today, but this richness is usually characterized as a geologically recent development (Neogene or Pleistocene). From caldera-lake beds exposed at Laguna del Hunco in Patagonia, Argentina, paleolatitude approximately 47 degrees S, we report 102 leaf species. Radioisotopic and paleomagnetic analyses indicate that the flora was deposited 52 million years ago, the time of the early Eocene climatic optimum, when tropical plant taxa and warm, equable climates reached middle latitudes of both hemispheres. Adjusted for sample size, observed richness exceeds that of any other Eocene leaf flora, supporting an ancient history of high plant diversity in warm areas of South America.

  2. High plant diversity in Eocene South America: Evidence from Patagonia

    USGS Publications Warehouse

    Wilf, P.; Cuneo, N.R.; Johnson, K.R.; Hicks, J.F.; Wing, S.L.; Obradovich, J.D.

    2003-01-01

    Tropical South America has the highest plant diversity of any region today, but this richness is usually characterized as a geologically recent development (Neogene or Pleistocene). From caldera-lake beds exposed at Laguna del Hunco in Patagonia, Argentina, paleolatitude ~47oS, we report 102 leaf species. Radioisotopic and paleomagnetic analyses indicate that the flora was deposited 52 million years ago, the time of the early Eocene climatic optimum, when tropical plant taxa and warm, equable climates reached middle latitudes of both hemispheres. Adjusted for sample size, observed richness exceeds that of any other Eocene leaf flora, supporting an ancient history of high plant diversity in warm areas of South America.

  3. Origin and evolution of the Laguna Potrok Aike maar (Patagonia, Argentina)

    NASA Astrophysics Data System (ADS)

    Gebhardt, A. C.; de Batist, M.; Niessen, F.; Anselmetti, F. S.; Ariztegui, D.; Ohlendorf, C.; Zolitschka, B.

    2009-04-01

    Laguna Potrok Aike, a maar lake in southern-most Patagonia, is located at about 110 m a.s.l. in the Pliocene to late Quaternary Pali Aike Volcanic Field (Santa Cruz, southern Patagonia, Argentina) at about 52°S and 70°W, some 20 km north of the Strait of Magellan and approximately 90 km west of the city of Rio Gallegos. The lake is almost circular and bowl-shaped with a 100 m deep, flat plain in its central part and an approximate diameter of 3.5 km. Steep slopes separate the central plain from the lake shoulder at about 35 m water depth. At present, strong winds permanently mix the entire water column. The closed lake basin contains a sub saline water body and has only episodic inflows with the most important episodic tributary situated on the western shore. Discharge is restricted to major snowmelt events. Laguna Potrok Aike is presently located at the boundary between the Southern Hemispheric Westerlies and the Antarctic Polar Front. The sedimentary regime is thus influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Previous studies demonstrated that closed lakes in southern South America are sensitive to variations in the evaporation/precipitation ratio and have experienced drastic lake level changes in the past causing for example the desiccation of the 75 m deep Lago Cardiel during the Late Glacial. Multiproxy environmental reconstruction of the last 16 ka documents that Laguna Potrok Aike is highly sensitive to climate change. Based on an Ar/Ar age determination, the phreatomagmatic tephra that is assumed to relate to the Potrok Aike maar eruption was formed around 770 ka. Thus Laguna Potrok Aike sediments contain almost 0.8 million years of climate history spanning several past glacial-interglacial cycles making it a unique archive for non-tropical and non-polar regions of the Southern Hemisphere. In particular, variations of

  4. Detailed interpretation of aeromagnetic data from the Patagonia Mountains area, southeastern Arizona

    USGS Publications Warehouse

    Bultman, Mark W.

    2015-01-01

    Euler deconvolution depth estimates derived from aeromagnetic data with a structural index of 0 show that mapped faults on the northern margin of the Patagonia Mountains generally agree with the depth estimates in the new geologic model. The deconvolution depth estimates also show that the concealed Patagonia Fault southwest of the Patagonia Mountains is more complex than recent geologic mapping represents. Additionally, Euler deconvolution depth estimates with a structural index of 2 locate many potential intrusive bodies that might be associated with known and unknown mineralization.

  5. [Don Rodolfo Armas Cruz: physician, professor and teacher].

    PubMed

    1996-05-01

    The present issue of Revista Médica de Chile contains tributes to the late Profesor Rodolfo Armas Cruz prepared by the Editors and, by invitation by two of his closest disciples and collaborators. With the decease of Professor Dr Rodolfo Armas Cruz on November 26, 1995, disappeared a representative of a medical generation, whose unique work transformed national medical tasks, lending prestige to Chilean medicine. His peers recognized in him as a distinguished master and his work was so vast that is difficult to underscore a particular aspect. Over and above his books and scientific reports, remains the testimony of hundreds of his disciples distributed along Chile that, marked by his teachings trying to follow his path. The honors, awards and titles never separated him from an austere way of life, dedicated to work besides the ill, his students and his beloved Medical Service at the San Juan de Dios Hospital. His transcendental name and work, incorporated to the history of Chilean medicine, will be an example for actual and future medical generations.

  6. 77 FR 49862 - Santa Cruz and Monterey Bay Railway Company-Acquisition and Operation Exemption-Union Pacific...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Surface Transportation Board Santa Cruz and Monterey Bay Railway Company--Acquisition and Operation Exemption--Union Pacific Railroad Company Santa Cruz and Monterey Bay Railway Company (SCMB), a noncarrier...). The Line, known as the Santa Cruz Branch, extends from milepost 0.433 at the east boundary of...

  7. 77 FR 49863 - Iowa Pacific Holdings, LLC and Permian Basin Railways-Continuance in Control Exemption-Santa Cruz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Control Exemption--Santa Cruz and Monterey Bay Railway Company Iowa Pacific Holdings, LLC, and Permian....2(d)(2) to continue in control of Santa Cruz and Monterey Bay Railway Company (SCMB) upon SCMB's... Pacific Railroad Company (UP). The Line, known as the Santa Cruz Branch, extends from milepost 0.433...

  8. 77 FR 49862 - Santa Cruz and Monterey Bay Railway Company-Assignment of Lease Exemption-Union Pacific Railroad...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Surface Transportation Board Santa Cruz and Monterey Bay Railway Company--Assignment of Lease Exemption--Union Pacific Railroad Company and Sierra Northern Railway Santa Cruz and Monterey Bay Railway Company...) owned by Union Pacific Railroad Company (UP). The Line, known as the Santa Cruz Branch, extends...

  9. 76 FR 6154 - Notice of Realty Action: Modified Competitive Bid Sale of Public Lands in Santa Cruz County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... Lands in Santa Cruz County, CA AGENCY: Bureau of Land Management, Interior. ACTION: Notice of realty... public land consisting of approximately 12.55 acres in Santa Cruz County, California, for not less than..., 2, and 9. The area described contains 12.55 acres, more or less, in Santa Cruz County. The...

  10. Niche Segregation between Wild and Domestic Herbivores in Chilean Patagonia

    PubMed Central

    Iranzo, Esperanza C.; Traba, Juan; Acebes, Pablo; González, Benito A.; Mata, Cristina; Estades, Cristián F.; Malo, Juan E.

    2013-01-01

    Competition arises when two co-occuring species share a limiting resource. Potential for competition is higher when species have coexisted for a short time, as it is the case for herbivores and livestock introduced in natural systems. Sheep, introduced in the late 19th century in Patagonia, bear a great resemblance in size and diet to the guanaco, the main native herbivore in Patagonia. In such circumstances, it could be expected that the two species compete and one of them could be displaced. We investigated spatial overlap and habitat selection by coexisting sheep and guanaco in winter and in summer. Additionally, we studied habitat selection of the guanaco in a control situation free from sheep, both in summer and winter. We also determined overlap between species in areas with different intensity of use (named preferred and marginal areas) in order to further detect the potential level of competition in the case of overlapping. Guanaco and sheep showed significantly different habitat preferences through all seasons, in spite of their spatial overlap at landscape scale. Additionally, the habitat used by guanaco was similar regardless of the presence or absence of livestock, which further indicates that sheep is not displacing guanaco where they coexist. These results suggest that habitat segregation between guanaco and sheep is due to a differential habitat selection and not to a competitive displacement process. Therefore, the potential for competition is considered low, contrary to what has been previously observed, although this could be a density-dependent result. PMID:23555656

  11. Late cretaceous aquatic plant world in Patagonia, Argentina.

    PubMed

    Cúneo, N Rubén; Gandolfo, María A; Zamaloa, María C; Hermsen, Elizabeth

    2014-01-01

    In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

  12. Late Cretaceous Aquatic Plant World in Patagonia, Argentina

    PubMed Central

    Cúneo, N. Rubén; Gandolfo, María A.; Zamaloa, María C.; Hermsen, Elizabeth

    2014-01-01

    In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America. PMID:25148081

  13. The Border Environmental Health Initiative-investigating the transboundary Santa Cruz watershed

    USGS Publications Warehouse

    Norman, Laura M.; Callegary, James; van Riper, Charles; Gray, Floyd

    2010-01-01

    In 2004 the U.S. Geological Survey (USGS) launched the Border Environmental Health Initiative (BEHI), a major project encompassing the entire U.S.-Mexico border region. In 2009, a study of the Santa Cruz River Watershed (SCW), located in the border region of Arizona and Sonora, Mexico, was initiated as part of the BEHI. In this borderland region of the desert Southwest, human health and the ecosystems on which humans rely depend critically on limited water resources. Surface water is scarce during much of the year, and groundwater is the primary source for industrial, agricultural, and domestic use. In order to identify risks to water resources in the SCW, and the potential consequences to riparian ecosystems and ultimately human health, the USGS is using an interdisciplinary and integrative approach that incorporates the expertise of geographers, hydrologists, biologists, and geologists to track organic and inorganic contaminants and their effects from sources to sinks in sediment, water, plants, and animals. Existing groundwater and surface-water models are being used and modified to assess contaminant and sediment transport.

  14. Fe-Ni Micrometorites from Upper Jurassic Cañadon Asfalto Fm., Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Matteini, M.; Hauser, N.; Cabaleri, N.; Silva Nieto, D.; Cuadros, F. A.; Reyes, S.

    2014-09-01

    Microspherules from an upper Jurassic sediments from Patagonia, show mineralogical, geochemical and textural features very similar to those reported for I-type micrometeorites whereas some spherules are interpreted as typical G-type micrometeorites.

  15. Loma Prieta earthquake, October 17, 1989, Santa Cruz County, California

    SciTech Connect

    McNutt, S.

    1990-01-01

    On Tuesday, October 17, 1989 at 5:04 p.m. Pacific Daylight Time, a magnitude 7.1 earthquake occurred on the San Andreas fault 10 miles northeast of Santa Cruz. This earthquake was the largest earthquake to occur in the San Francisco Bay area since 1906, and the largest anywhere in California since 1952. The earthquake was responsible for 67 deaths and about 7 billion dollars worth of damage, making it the biggest dollar loss natural disaster in United States history. This article describes the seismological features of the earthquake, and briefly outlines a number of other geologic observations made during study of the earthquake, its aftershocks, and its effects. Much of the information in this article was provided by the U.S. Geological Survey (USGS).

  16. Gastrointestinal helminths of Commerson's dolphins Cephalorhynchus commersonii from central Patagonia and Tierra del Fuego.

    PubMed

    Berón-Vera, B; Pedraza, S N; Raga, J A; Gil de Pertierra, A; Crespo, E A; Alonso, M K; Goodall RNP

    2001-12-05

    The stomachs and intestines of 9 Commerson's dolphins incidentally caught in trawl nets in central Patagonia and 23 stranded on beaches in Tierra del Fuego were surveyed for helminth parasites. A total of 267 individuals belonging to 4 species of parasites (1 nematode, 3 digeneans) were found in the dolphins from the first area: Anisakis sp. (larvae type 1 = A. simplex), Braunina cordiformis, Hadwenius sp. and Pholeter gastrophilus. In the Tierra del Fuego dolphins, 142 specimens belonging to 3 species (2 nematodes, 1 digenean, 1 cestode) were found: A. simplex, Hadwenius sp. and Strobilocephalus triangularis. Only 2 of the helminth species were shared in the 2 study areas, A. simplex and Hadwenius sp., and both were more common in central Patagonia. Among the species, A. simplex was most prevalent and abundant in both study areas. In Tierra del Fuego, adults of A. simplex appeared in only 1 host. Hadwenius sp., P. gastrophilus and S. triangularis are new host records for Commerson's dolphin. Species diversity and species richness were low in both study areas. Helminth communities were more diverse in central Patagonia (t = 1.97, df = 258, p < 0.05) and species richness was higher in central Patagonia (S = 4). No differences in diversity were observed between females and males of central Patagonia (t = 1.97, df = 139, p < 0.05) and between females of central Patagonia and Tierra del Fuego. The results may suggest some differences in habitat use, diet and sex between Commerson's dolphin populations in the 2 study areas.

  17. Airborne laser altimetry survey of Glaciar Tyndall, Patagonia

    NASA Astrophysics Data System (ADS)

    Keller, Kristian; Casassa, Gino; Rivera, Andrés; Forsberg, Rene; Gundestrup, Niels

    2007-10-01

    The first airborne laser altimetry measurements of a glacier in South America are presented. Data were collected in November of 2001 over Glaciar Tyndall, Torres del Paine National Park, Chilean Patagonia, onboard a Twin Otter airplane of the Chilean Air Force. A laser scanner with a rotating polygon-mirror system together with an Inertial Navigation System (INS) were fixed to the floor of the aircraft, and used in combination with two dual-frequency GPS receivers. Together, the laser-INS-GPS system had a nominal accuracy of 30 cm after data processing. On November 23rd, a total of 235 km were flown over the ablation area of Glaciar Tyndall, with 5 longitudinal tracks with a mean swath width of 300 m, which results in a point spacing of approximately 2 m both along and across track. A digital elevation model (DEM) generated using the laser altimetry data was compared with a DEM produced from a 1975 map (1:50,000 scale — Instituto Geográfico Militar (IGM), Chile). A mean thinning of - 3.1 ± 1.0 m a - 1 was calculated for the ablation area of Glaciar Tyndall, with a maximum value of - 7.7 ± 1.0 m a - 1 at the calving front at 50 m a.s.l. and minimum values of between - 1.0 and - 2.0 ± 1.0 m a - 1 at altitudes close to the equilibrium line altitude (900 m a.s.l.). The thinning rates derived from the airborne survey were similar to the results obtained by means of ground survey carried out at ˜ 600 m of altitude on Glaciar Tyndall between 1975 and 2002, yielding a mean thinning of - 3.2 m a - 1 [Raymond, C., Neumann, T.A., Rignot, E., Echelmeyer, K.A., Rivera, A., Casassa, G., 2005. Retreat of Tyndall Glacier, Patagonia, over the last half century. Journal of Glaciology 173 (51), 239-247.]. A good agreement was also found between ice elevation changes measured with laser data and previous results obtained with Shuttle Radar Topography Mission (SRTM) data. We conclude that airborne laser altimetry is an effective means for accurately detecting glacier elevation

  18. Study of UV cloud modification factors in Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Wolfram, Elian A.; Orte, Facundo; Salvador, Jacobo; Quiroga, Jonathan; D'Elia, Raúl; Antón, Manuel; Alados-Arboledas, Lucas; Quel, Eduardo

    2017-02-01

    Anthropogenic perturbation of the ozone layer has induced change in the amount of UV radiation that reaches the Earth's surface, mainly through the Antarctic ozone hole, making the ozone and ultraviolet (UV) radiation two important issues in the study of Earth atmosphere in the scientific community. Also the clouds have been identified as the main modulator of UV amount in short time scales and produce the main source of uncertainty in the projection of surface UV level as consequence of projected ozone recovery. While clouds can decrease direct radiation, they can produce an increase in the diffuse component, and as consequence the surface UV radiation may be higher than an equivalent clear sky scenario for several minutes. In particular this situation can be important when low ozone column and partially cloud cover skies happen simultaneously. These situations happen frequently in southern Patagonia, where the CEILAP Lidar Division has established the Atmospheric Observatory of Southern Patagonia, an atmospheric remote sensing site near the city of Río Gallegos (51°55'S, 69°14'W). In this paper, the impact of clouds over the UV radiation is investigated by the use of ground based measurements from the passive remote sensing instruments operating at this site, mainly of broad and moderate narrow band filter radiometers. We analyzed the UV Index obtained from a multiband filter radiometer GUV-541 (UVI) [Biospherical Inc.] installed in the Observatorio Atmosférico de la Patagonia Austral, Río Gallegos, since 2005. Cloud modification factors (CMF, ratio between the measured UV radiation in a cloudy sky and the simulated radiation under cloud-free conditions) are evaluated for the study site. The database used in this work covers the period 2005-2012 for spring and summer seasons, when the ozone hole can affect these subpolar regions. CMF higher than 1 are found during spring and summer time, when lower total ozone columns, higher solar elevations and high cloud

  19. Le site paléo-indien de Piedra Museo (Patagonie). Sa contribution au débat sur le premier peuplement du continent américainThe palaeo-indian site of Piedra Museo (Patagonia). Its contribution to the debate on the peopling of the Americas.

    NASA Astrophysics Data System (ADS)

    Ramirez Rozzi, Fernando V.; d'Errico, Francesco; Zarate, Marcelo

    2000-08-01

    The Piedra Museo site (Santa Cruz, Argentina), excavated over the past nine years has yielded a rich archaeological record, which contributes to the discussion on the first peopling of the Americas. We present here a new study of the site, based on an analysis of the stratigraphy, spatial distribution of archaeological remains, bone taphonomy, and discussion of new AMS- 14C dates. We conclude that remains of extinct species with cut-marks from the lower levels are contemporaneous of stone tools and cores from the same levels. This demonstrates that humans were present in the southern part of Patagonia around 10 300 and 11 100 years BP and suggests that hunting of large mammals was a part of their subsistence strategies.

  20. [Diagnosis of caseous lymphadenitis in sheep from Patagonia].

    PubMed

    Estevao Belchior, S; Gallardo, A; Abalos, A; Díaz, Y; Alvarez, L; Callejo, R; Prieto, M; Jodor, N; Jensen, O

    2007-01-01

    Caseous lymphadenitis (CLA) is a chronic bacterial, infectious and contagious disease caused by Corynebacterium pseudotuberculosis. It affects sheep and results in abscesses of the lymph nodes in subcutaneous tissue, as well as in internal organs such as lungs, liver and kidneys. Differential diagnosis of the disease is based on the isolation and biochemical identification of the etiological agent. The purpose of this study was to characterize the bacteria isolated from typical CLA lesions in sheep from Patagonia, Argentina, at metabolic and genetic levels. Macroscopic observations show a fibrous membrane containing caseous necrotic tissue. Histopathological analysis shows an eosinophilic necrotic area surrounded by epitheloid cells and polymorphonuclear infiltration. Other analyses performed such as microscopic observations, in vitro culture, biochemical tests and 16s rDNA sequencing confirmed diagnosis of caseous lymphadenitis due to C. pseudotuberculosis.

  1. Splendid and Seldom Isolated: The Paleobiogeography of Patagonia

    NASA Astrophysics Data System (ADS)

    Wilf, Peter; Cúneo, N. Rubén; Escapa, Ignacio H.; Pol, Diego; Woodburne, Michael O.

    2013-05-01

    The idea that South America was an island continent over most of the Cenozoic, during which its unusual mammalian faunas evolved in isolation, is outstandingly influential in biogeography. Although large numbers of recent fossil discoveries and related advances require that the original isolation concept be significantly modified, it is still repeated in much current literature. The persistence of the idea inspired us to present here an integrated paleobiogeographic account of mammals, reptiles, and plants from the Jurassic to the Paleogene of Patagonia, which has by far the richest fossil record on the continent. All three groups show distribution patterns that are broadly consistent with South America's long separation history, first from Laurasia by the Late Jurassic, then from Africa and India-Madagascar during the late Early Cretaceous, and finally from Antarctica and Australia during the early-middle Eocene, after which “isolation” finally commenced. We highlight areas of promising future research and provide an updated view of South American isolation.

  2. Magnetostratigraphy of continental glacial deposits in southernmost Patagonia

    NASA Astrophysics Data System (ADS)

    Griffing, C. Y.; Barendregt, R. W.; Clague, J. J.; Roberts, N. J.; Corbella, H.; Ercolano, B.; Rabassa, J.

    2012-12-01

    Southernmost Patagonia has well preserved records of continental and alpine glaciations. It is the only region in the Southern Hemisphere outside Antarctica where large Pleistocene ice sheets developed, thus it offers a unique opportunity to enhance understanding of global climate variability. Previous research on the glacial history of Patagonia is largely based on geomorphology, with limited study of stratigraphy and relatively few absolute ages. Consequently, the number, ages, and geographic extent of individual glaciations are not well understood. Geomorphic evidence of multiple Quaternary glaciations is widespread in the region and includes moraines, erratics, drumlin fields, and outwash plains. Exposures of glacial sediments are common along the Atlantic coast, the Strait of Magellan, meltwater channels, and in gravel pits. Most of the glacial deposits are beyond the range of radiocarbon dating. K-Ar and Ar-Ar dating have been used to determine the ages of basalt flows interlayered with till and outwash in the southern Andes to the west and in the Rio Gallegos valley near the Atlantic coast. These absolute ages suggest that glaciation in Patagonia began in the late Miocene and that the Pleistocene Patagonian ice sheet may have decreased in size with each successive advance. We conducted a paleomagnetic study of glacial sediments to further constrain the timing of continental glaciations. The sediments are stably magnetized, providing clear directional data from which polarity can be determined. Most sediments in the area are normally magnetized, but some sediments near the outer limit of glaciation, within areas covered by the Patagonian ice sheet during the Great Patagonian Glaciation (GPG), are reversely magnetized. Recent field work indicates that drift of the GPG comprises deposits of several glaciations. Our paleomagnetic results suggest that the first continental glaciation(s) in the region occurred during the Matuyama Reversed Chron (2.6 - 0.78 Ma) and

  3. A late Jurassic pterosaur (Reptilia, Pterodactyloidea) from northwestern Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Codorniú, Laura; Gasparini, Zulma; Paulina-Carabajal, Ariana

    2006-03-01

    A small to medium-sized pterodactyloid pterosaur (wingspan approximately 1.10 m) from the Upper Jurassic (middle-late Tithonian) marine deposits of the Vaca Muerta Formation of Patagonia (Los Catutos area, central Neuquén Province, Argentina) is reported. The specimen lacks the skull but constitutes a nearly complete postcranial skeleton, which includes cervical and dorsal vertebrae; a few thoracic ribs; both pectoral girdles; the left pelvic girdle; a proximal right wing (humerus, ulna, and radius) and metacarpal IV; a left wing that lacks only wing phalanx four; and both hindlimbs, the right one without the foot. Ontogenetic features suggest that the new fossil corresponds to a relatively mature individual, probably a subadult. Observed characters support its assignment to the Archaeopteroactyloidea, a basal clade within the Pterodactyloidea. This specimen is the second pterosaur from Los Catutos and the most complete Jurassic pterosaur so far known from South America.

  4. Phytoseiid mites (Acari: Phytoseiidae) from Patagonia and Tierra del Fuego.

    PubMed

    Ferragut, Francisco; Navia, Denise

    2015-07-28

    Predatory phytoseiid mites have been intensively studied and surveyed in the last decades because of their economic importance as biocontrol agents of agricultural pests. However, many regions of the world remain unexplored and the diversity of the family worldwide is still fragmentary. Up to date no phytoseiid species have been collected in the southernmost part of the Earth down to latitude 45º S. In this study Phytoseiidae were sampled from native vegetation in southern Argentina and Chile in the regions of Patagonia and Tierra del Fuego Island. Thirteen species were collected, five of which were previously described and eight, Chileseius australis n. sp., Neoseiulus mapuche n. sp., Typhlodromips valdivianus n. sp., T. fissuratus n. sp., Amblyseius grandiporus n. sp., A. caliginosus n. sp., Typhlodromus (Anthoseius) anomalos n. sp. and Metaseiulus parabrevicollis n. sp. are proposed as new to science and are described and diagnosed.

  5. Reptile and rodent parasites in raptor pellets in an archaeological context: the case of Epullán Chica (northwestern Patagonia, Argentina)

    NASA Astrophysics Data System (ADS)

    Beltrame, María Ornela; Fernández, Fernando Julián; Sardella, Norma Haydeé

    2015-07-01

    Paleoparasitology is the study of parasite remains from archaeological and paleontological sites. Raptor pellets can be used as source for paleoparasitological information in archaeological sites. However, this zooarchaeological material has been scarcely studied. Epullán Chica (ECh) is an archaeological site in northwestern Patagonia. This cave yielded remains from more than 2000 years before present. The aim of this paper was to study the parasite remains found in owl pellets from the archaeological site ECh, and to discuss the paleoparasitological findings in an archaeological context. Twenty two raptor pellets were examined for parasites. The pellets were whole processed by rehydration in a 0.5% water solution of trisodium phosphate, followed by homogenization, filtered and processed by spontaneous sedimentation. Eight out of 22 bird pellets examined were positive for parasites from reptiles and rodents. Representatives of 12 parasite taxa were recorded; nine of this parasitic species were reported for the first time from ancient samples from Patagonia. This is the first time that pellets give evidences of ancient reptile parasites from archaeological contexts. It is noteworthy that Late Holocene hunter-gatherers of the upper Limay River basin, could have been exposed to some of these zoonotic parasites. Future paleoparasitological studies on owl pellets may reflect even more the parasitological diversity of all micromammal and reptile species presents in ancient times.

  6. Oceanographic Processes in Chilean Fjords of Patagonia: From small to large-scale studies

    NASA Astrophysics Data System (ADS)

    Iriarte, José L.; Pantoja, Silvio; Daneri, Giovanni

    2014-12-01

    Subantarctic ecosystems, such as the inner shelf of southern Chile (41-55°S), are characterized by a complex system of fjords, channels, gulf, estuaries, bays, and are affected by physical regimes that may strongly modulate biological productivity. Rhythms and rates of primary production in these highly fluctuating fjord environments depend to a large extent on the timing and magnitude of nutrient supply and light availability for primary producers. In such complex fjord systems, the interaction between oceanic waters and freshwater from multiple sources (e.g., rivers, surface and groundwater runoff, snow/glacier melting, and precipitation) produces strong vertical and horizontal gradients in salinity, density, organic and inorganic nutrient ratios and light availability (Pickard, 1971; Dávila et al., 2002; Silva and Palma 2006; Jacob et al., 2014). The vertical structure of the water column (stratified/mixed), modulated by the seasonal and inter-annual changes of the pycnocline may affect biomass and composition of pelagic and benthic assemblages, and ultimately spatial and temporal patterns of carbon fluxes (the 'Biological Pump'), and biogeochemical balances in this large region. In addition, the region is particularly vulnerable to climate change and anthropogenic influences (Iriarte et al., 2010). Remote and large-scale climatic-oceanographic phenomena (e.g., ENSO and Southern Annular Mode) and global climate trends may alter freshwater discharge of large rivers such as the Puelo and Palena, as has also been suggested for the Baker River located between Patagonian Ice fields and other northern fjords shown by paleo-oceanographic (Sepúlveda et al., 2009; Rebolledo et al., 2011) and dendrochronological studies (Lara et al., 2008). Although changes in climate are expected to alter the regional atmospheric forcing such as the West Wind Drift (Quintana and Aceituno, 2012; Garreaud et al., 2013) and the local ocean circulation in this region, including the

  7. The origin of oriented lakes in the Andean foreland, Parque Nacional Torres del Paine (Chilean Patagonia)

    NASA Astrophysics Data System (ADS)

    Gonzales, Joseph; Aydin, Atilla

    2008-05-01

    The Parque Nacional Torres Del Paine and surrounding area in the Magallanes foreland basin in Chilean Patagonia is the site for numerous lakes fed by glaciers and rivers in the Andean highlands to the west. The lakes are elongate and have conspicuously systematic orientations. We hypothesize that the origin of the oriented lakes lies in the fault system, composed of a right-lateral strike-slip fault set oriented 58° from north, a left-lateral strike-slip set oriented 87°, and a thrust fault set oriented 167°, that exists within the underlying rocks. To test this hypothesis quantitatively, we determined the shape and orientation of the lakes by fitting each lake with an ellipse of appropriate aspect ratio, and later with multiple ellipses consistent with the composite geometry of some lakes. We then examined the faults in the area in terms of their kinematics, orientation and distribution. The distribution of lake orientations showed three distinct groups which appear to correspond to the three main fault groups. For lakes fitted with multiple ellipses, the difference in means between the right-lateral, left-lateral, and thrust faults and their corresponding groups of lakes are 3.05°, 1.57°, and 5.17°. Using a Kolmogorov-Smirnov (K-S) statistical test to compare the orientations of faults with respect to the lakes suggests that there is not a strongly significant difference between the fault orientations and the corresponding lake groups. These results indicate that the faults have a profound control on the orientation, shape, and distribution of the lakes. We attribute this to faults and their damage zones being weaker and therefore prone to a faster rate of erosion, and to stress perturbations associated with discontinuous faults resulting in localized high density fracturing and surface subsidence. These results have implications for lake and drainage system morphologies in other foreland basins along the Andes and other similar settings.

  8. Geochemistry of surface sediments from the fjords of Northern Chilean Patagonia (44-47°S): Spatial variability and implications for paleoclimate reconstructions

    NASA Astrophysics Data System (ADS)

    Bertrand, Sébastien; Hughen, Konrad A.; Sepúlveda, Julio; Pantoja, Silvio

    2012-01-01

    The Patagonian fjords have a clear potential to provide high-resolution sedimentary and geochemical records of past climate and environmental change in the Southern Andes. To improve our ability to interpret these proxy records, we investigated the processes that control fjord sediment inorganic geochemistry through a geochemical, mineralogical and sedimentological analysis of surface sediment samples from the fjords of Northern Chilean Patagonia. A simple Terrestrial Index based on measurements of salinity and Fraction of Terrestrial Carbon was used to estimate the terrestrial input/river discharge at each site. Our results demonstrate that, under the cold climate conditions of Patagonia, chemical weathering is weak and the inorganic geochemical composition of the fjord sediments is primarily controlled by hydrodynamic mineralogical sorting, i.e., the intensity of river discharge. Our results suggest that the distribution of Fe, Ti and Zr in surface sediments is controlled by their association with heavy and/or coarse minerals, whereas Al is independent of hydrodynamic processes. The elemental ratios Fe/Al, Ti/Al and Zr/Al are therefore well suited for estimating changes in the energy of terrestrial sediment supply into the fjords through time. Zr/Al is particularly sensitive in proximal environments, while Fe/Al is most useful in the outer fjords and on the continental margin. In the most proximal environments, however, Fe/Al is inversely related to hydrodynamic conditions. Caution should therefore be exercised when interpreting Fe/Al ratios in terms of past river discharge. The application of these proxies to long sediment cores from Quitralco fjord and Golfo Elefantes validates our interpretations. Our results also emphasize the need to measure Al-based elemental ratios at high precision, which can be achieved using simultaneous acquisition ICP-AES technology. This study therefore constitutes a strong basis for the interpretation of sedimentary records from the

  9. Source process for the 2013 Santa Cruz Islands earthquake

    NASA Astrophysics Data System (ADS)

    Park, Eun Hee; Park, Sun-Cheon; Lee, Jun-Whan

    2015-04-01

    Many places in the world have experienced damage from tsunami. Most tsunamis are induced by large earthquakes that occur under the sea along the trench. Therefore understanding the characteristics of large earthquakes is important to evaluate tsunami hazard as well as earthquake damage. In order to understand the characteristics of large tsunamigenic earthquakes, in this study we analyzed the source process of the 2013 Santa Cruz earthquake (M8.0) on Feb. 6, 2013. According to the U.S. Geological Survey (USGS), 56 earthquakes with magnitudes greater than 5.5 occurred in Jan. 27 - March 8, 2013. Among them, eleven events happened for a week before the mainshock and the maximum magnitude was 6.4. A large aftershock with magnitude of 7.1 occurred immediately after the mainshock, about 10 minutes later. Including this event, the 2013 Santa Cruz event seems to be followed by two large aftershocks of M~7. The length of spatial distribution of aftershocks in 30 days was about 200 km. And this value of the length was used for rough estimation of the fault length during the waveform inversion process. We carried out teleseismic body-wave inversion to obtain the slip distribution of the 2013 earthquake. Teleseismic P waveform data from 19 stations in the epicentral distance between 30° and 90° were used and band-pass filter at 0.005 - 1.0 Hz was applied. And focal depth was assumed to be 28.7 km, according the USGS catalog. And the initial value of source time window was assumed as 120 seconds by the duration of high-frequency energy radiation. According to our inversion results, the fault plane seems the northwesterly striking (strike = 291) and shallowly dipping (dip = 24) fault plane. Large slip area was seen near the hypocenter. Rupture velocity was obtained to be 2.0 km/s. And moment magnitude of 7.9 and maximum dislocation of 1.4 m had the smallest variance between the observed and synthetic waveforms. These values were smaller than the result of previous study. To

  10. Lithospheric Mantle heterogeneities beneath northern Santa Cruz province, Argentina

    NASA Astrophysics Data System (ADS)

    Mundl, Andrea; Ntaflos, Theodoros; Bjerg, Ernesto

    2013-04-01

    Mantle xenoliths from Don Camilo, an area located on the North margin of the Deseado Masiff in Patagonia, comprise spinel bearing lherzolites, harburgites and dunites, wehrlites, clinopyroxenites and gabbros. The most common rock type in our collection is spinel-lherzolite followed by dunites. Harzurgites, wehrlites and gabbros are less widespread. Spinel-lherzolites and harzburgites have protogranular textures whereas dunites have equigranular to equigranular tabular textures. There are two kinds of dunites: mantle dunites and cumulate dunites. The olivine mg# in the mantle dunites vary within a narrow range, from 90.5 to 91.5 and the NiO content from 0.39 to 0.42 wt%, whereas in the cumulate dunites the mg# ranges from 87 to 90.5 and the NiO content from 0.22 to 0.40 wt%. Both types of dunites contain fine grained interstitial diopside. Hydrous phases, besides one sample that contains amphibole, were so far not found. The spinel peridotites have whole rock REE abundances depleted in LREE [(La/Yb)N=0.34-0.85)] and the dunitesare LREE enriched [(La/Yb)N=3.49]. LA-ICP-MS analyses of cpx show that a number of the studied spinel peridotite xenoliths experienced cryptic metasomatism. Three groups of xenoliths have been recognized according to REE and other incompatible trace element patterns in cpx: group I has depleted LREE abundances, group II is highly enriched in LREE (La=20-30 x C1) and group 3 has moderate LREE enrichments. The core of some clinopyroxenes in group II has depleted LREE similar to those in group I, apparently representing relictic cores not affected by metasomatism. In addition the metasomatized clinopyroxenes are significantly enriched in Sr, Th and U. Evidently, the metasomatic agent was a H2O-rich fluid (high LREE, Sr, Th and U). Clinopyroxene Sr and Nd isotopic ratios vary largely from 0.702671 to 0.705788 and from 0.51229 to 0.513251 respectively. Mantle and cumulate dunites have experienced modal metasomatism. In both types of dunites the

  11. Introduction and Establishment of Pissodes castaneus (Coleoptera: Curculionidae) in the Andean Patagonia of Argentina.

    PubMed

    Pereyra, V A; Gomez, C A; La Manna, L; Roux, G; Lanteri, A A; Vallejos, N C; Marvaldi, A E

    2016-02-01

    The pine weevils that occur in plantations of Pinus spp. in Andean Patagonia of Argentina belong to the species Pissodes castaneus (De Geer), a Eurasian endemic species, according to the identification based on molecular and morphological characters. Sequences of the mitochondrial Cytochrome oxidase subunit I and nuclear genes (28 S rDNA and ITS2) were obtained for individuals of 13 afforestations, covering the entire distribution area of the established populations in the Andean Patagonia of Argentina. Sequence comparison with representative species of the genus (European, North American, and Chinese species) shows that Patagonian specimens are conspecific to those of P. castaneus sequenced from Europe. Phylogenetic analyses indicate that all terminals from Patagonia form a monophyletic unit without evident subclades, eliminating the possibility of existence of more than one species of Pissodes Germar in this area, including cryptic ones. Moreover, the very low genetic divergence between the Patagonian populations suggests that it is plausible that P. castaneus was introduced into Patagonia from just one location. Mitochondrial DNA analysis shows that Patagonian terminals group together with a French haplotype and are clearly separated from other P. castaneus individuals represented in our sample, and reveal that established populations in Andean Patagonia originated via a limited introduction.

  12. Women of Apelo Cruz. Organizing for change: the Philippines.

    PubMed

    Bolido, L

    1995-01-01

    In the Philippines, the Apelo Women's Health Association (AWHA) was organized in 1991 to help economically depressed women take control of their lives, their health, and their fertility. One woman being helped by AWHA is 17-year-old Vilma, who was married and separated at 13, became a bar girl at 14, miscarried at 15, bore a son at 16, and had an abortion. Because of AWHA, Vilma is now using oral contraceptives and insisting that her customers use condoms. AWHA was set up by GABRIELA (the General Assembly Binding Women for Reforms, Integrity, Equality, Leadership, and Action) to replace the free, occasional medical care formerly available in the slum area of Apelo Cruz, in Pasay City. The free medical care fostered dependency instead of self-reliance among the women. AWHA, therefore, is a health cooperative which requires members to pay a minimal amount for services. AWHA also runs monthly educational activities to inform women of their rights, duties, and responsibilities. It provides a forum for the women in the neighborhood to speak their minds freely. The women are also grateful for the ability to control their fertility through the use of contraception.

  13. Monitoring Domoic Acid production by Solid Phase Adsorption Toxin Tracking off the Santa Cruz Municipal Warf, Santa Cruz, California

    NASA Astrophysics Data System (ADS)

    Nolan, M.; Ziccarelli, L.; Kudela, R. M.

    2013-12-01

    Certain species of the diatom genus Pseudo-nitzschia are producers of the neurotoxin, domoic acid (DA). DA is known to cause amnesic shellfish poisoning also known as domoic acid poisoning, which can lead to permanent brain damage in humans and marine mammals. DA accumulates at higher trophic levels, generally due to consumption of toxic cells or through trophic transfer, and can potentially cause death of both humans and marine wildlife. The Santa Cruz Municipal Warf experiences periodic rises in DA concentrations, which can reach toxic levels in shellfish, fish, and other marine organisms. While these increases in toxicity often occur during Pseudo-nitzschia blooms, several periods of elevated DA have occurred when diatom abundance is restricted and/or dominated by non-toxic species, and there is increasing evidence that DA dissolved in seawater may be prevalent. One theory suggests that senescent or dead Pseudo-nitzschia cells sink to the benthos while retaining their toxin and are buried in sediment following the death of a bloom. Therefore, DA may accumulate in the benthos, where it is eventually released during storms or wave and tide conditions that disturb the sediment. We sampled DA in situ using Solid Phase Adsorption Toxin Tracking (SPATT) bags SPATT uses a synthetic resin to capture dissolved DA, allowing for the determination of integrated DA concentrations at known time intervals. The alternative method is mussel biotoxin monitoring, but it is less accurate due to uncertainties in the time of DA accumulation within the mussel, and the lack of uptake of dissolved DA by the mussel. We deployed and collected SPATT off the Santa Cruz Municipal Wharf at multiple depths beginning in February 2013. We expect to see increasing DA following the death of a harmful algal bloom. Under pre-bloom conditions, little to no DA has been detected in mussels or surface SPATT, but DA from SPATT is frequently observed at depth, suggesting that the sediment is exposed to

  14. Cryptococcus species (Tremellales) from glacial biomes in the southern (Patagonia) and northern (Svalbard) hemispheres.

    PubMed

    de Garcia, Virginia; Zalar, Polona; Brizzio, Silvia; Gunde-Cimerman, Nina; van Broock, María

    2012-11-01

    Cryptococcus species (Basidiomycota) were isolated as the predominant yeast from glacial biomes of both Patagonia (Argentina) and the Svalbard archipelago (Norway). For a selected group of Cryptococcus belonging to Tremellales, assimilative profile, production of extracellular hydrolytic enzymes and ribosomal DNA internal transcribed spacer and large subunit (D1/D2) sequences were analysed. Cryptococcus victoriae, which was originally described from Antarctica, was the most frequently found species at both locations. High variability within the species was observed and described at the genotypic and phenotypic levels, two newly described species were found in both Patagonia and Svalbard: Cryptococcus fonsecae and Cryptococcus psychrotolerans. Two other new species were found only in Patagonia: Cryptococcus frias and Cryptococcus tronadorensis. Three additional new taxa were found, but they are not named as they were only represented by single isolates.

  15. Functional groups and activities of bacteria in a highly acidic volcanic mountain stream and lake in Patagonia, Argentina.

    PubMed

    Wendt-Potthoff, Katrin; Koschorreck, M

    2002-01-01

    Acidic volcanic waters are naturally occurring extreme habitats that are subject of worldwide geochemical research but have been little investigated with respect to their biology. To fill this gap, the microbial ecology of a volcanic acidic river (pH approximately equal to 0-1.6), Rio Agrio, and the recipient lake Caviahue in Patagonia, Argentina, was studied. Water and sediment samples were investigated for Fe(II), Fe(III), methane, bacterial abundances, biomass, and activities (oxygen consumption, iron oxidation and reduction). The extremely acidic river showed a strong gradient of microbial life with increasing values downstream and few signs of life near the source. Only sulfide-oxidizing and fermentative bacteria could be cultured from the upper part of Rio Agrio. However, in the lower part of the system, microbial biomass and oxygen penetration and consumption in the sediment were comparable to non-extreme aquatic habitats. To characterize similarities and differences of chemically similar natural and man-made acidic waters, our findings were compared to those from acidic mining lakes in Germany. In the lower part of the river and the lake, numbers of iron and sulfur bacteria and total biomass in sediments were comparable to those known from acidic mining lakes. Bacterial abundance in water samples was also very similar for both types of acidic water (around 10(5) mL(-1)). In contrast, Fe(II) oxidation and Fe(III) reduction potentials appeared to be lower despite higher biogenic oxygen consumption and higher photosynthetic activity at the sediment-water interface. Surprisingly, methanogenesis was detected in the presence of high sulfate concentrations in the profundal sediment of Lake Caviahue. In addition to supplementing microbiological knowledge on acidic volcanic waters, our study provides a new view of these extreme sites in the general context of aquatic habitats.

  16. Modern and subrecent spatial distribution and characteristics of sediment infill controlled by internal depositional dynamics, Laguna Potrok Aike (southern Patagonia, Argentina)

    NASA Astrophysics Data System (ADS)

    Kastner, S.; Ohlendorf, C.; Haberzettl, T.; Lücke, A.; Maidana, N. I.; Mayr, C.; Schäbitz, F.; Zolitschka, B.

    2009-04-01

    . Nonetheless, these homogenous patterns indicate distinct variations over time as several tributaries and the north-eastern outflow become influencing variables of the sediment distribution. Acknowledgements We are much obliged to Eva Hering (University of Cologne) for providing pollen data of her diploma thesis and to Thomas Chwalek (University of Munich) for providing isotope data of his bachelor thesis. References Haberzettl, T. et al. (2005). Climatically induced lake level changes during the last two millennia as reflected in sediments of Laguna Potrok Aike, southern Patagonia (Santa Cruz, Argentina). Journal of Paleolimnology 33: 283-302. Haberzettl, T. et al. (2007). Lateglacial and Holocene wet-dry cycles in southern Patagonia: chronology, sedimentology and geochemistry of a lacustrine record from Laguna Potrok Aike, Argentina. The Holocene, 17: 297-310. Mayr, C. et al. (2009). Isotopic and geochemical fingerprints of environmental changes during the last 16,000 years on lacustrine organic matter from Laguna Potrok Aike (southern Patagonia, Argentina). Journal of Paleolimnology. doi: 10.1007/s10933-008-9249-8). Wille, M. et al. (2007). Vegetation and climate dynamics in southern South America: The microfossil record of Laguna Potrok Aike, Santa Cruz, Argentina. Review of Palaeobotany and Palynology 146: 234-246.

  17. Towards a sediment budget for the Santa Cruz shelf

    USGS Publications Warehouse

    Eittreim, S.L.; Xu, J. P.; Noble, M.; Edwards, B.D.

    2002-01-01

    A conceptual model is presented for the northern Monterey Bay continental shelf in which coarse sediment moves southward along the coast in the littoral zone while fine sediment moves to the north by advection and diffusion along the midshelf. Data from measurements and estimates of various sediment sources and sinks show that the midshelf mudbelt is the dominant sink for fine-grained sediment introduced into Monterey Bay. The principal sources of the fine sediment are the three rivers that enter Monterey Bay: the San Lorenzo, Pajaro and Salinas rivers. Accumulation rates in the midshelf mudbelt are high relative to documented yields of rivers and cliff erosion, and also are high relative to other documented mud accumulations of the west coast continental shelves. ?? 2002 Elsevier Science B.V. All rights reserved.

  18. Digital soils survey map of the Patagonia Mountains, Arizona

    USGS Publications Warehouse

    Norman, Laura; Wissler, Craig; Guertin, D. Phillip; Gray, Floyd

    2002-01-01

    The ‘Soil Survey of Santa Cruz and Parts of Cochise and Pima Counties, Arizona,' a product of the USDA’s Soil Conservation Service and the Forest Service in cooperation with the Arizona Agricultural Experiment Station, released in 1979, was created according to the site conditions in 1971, when soil scientists identified soils types on aerial photographs. The scale at which these maps were published is 1:20,000. These soil maps were automated for incorporation into the hydrologic modeling within a GIS. The aerial photos onto which the soils units were drawn had not been orthoganalized, and contained distortion. A total of 15 maps composed the study area. These maps were scanned into TIFF format using an 8-bit black and white drum scanner at 100 dpi. The images were imported into ERDAS IMAGINE and the white borders were removed through subset decollaring processes. Five CD-ROM’s containing Digital Orthophoto Quarter Quads (DOQQ’s) were used to register and rectify the scanned soils maps. Polygonal data was then attributed according to the datasets.

  19. 75 FR 52969 - Final Environmental Impact Statement; Prisoners Harbor Wetland Restoration, Santa Cruz Island...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... National Park Service Final Environmental Impact Statement; Prisoners Harbor Wetland Restoration, Santa... coastal wetland on Santa Cruz Island, Channel Islands National Park. The requisite no-action ``wait period... restoration of palustrine wetlands and deepwater habitat at Prisoners Harbor, as well as remove a...

  20. The De-Genderization of Knowledge Production: The Case of Sor Juana Ines de la Cruz.

    ERIC Educational Resources Information Center

    Salazar, Norma

    1994-01-01

    All societies have official knowledge. Life of Sor Juana Ines de la Cruz, 17th-century nun and literary genius, illustrates who discovers knowledge is more important than what knowledge is promulgated. Real issue was not what Sor Juana wrote but whether nun or woman should engage in producing and publishing knowledge. Her efforts have inspired…

  1. A Historical Perspective on the University of California, Santa Cruz 1965-2005

    ERIC Educational Resources Information Center

    Rogers, Lynda M.

    2011-01-01

    Purpose: The purpose of this study was to trace the organizational history of the University of California Santa Cruz from its inception in 1965 to its 40th anniversary in 2005. The study investigated the original vision of small residential colleges as modeled after the Oxford University plan. The study chronicled the critical turning points of…

  2. Special Education Management System Project Document. 2. Santa Cruz BCP Observation Booklet.

    ERIC Educational Resources Information Center

    Santa Cruz County Superintendent of Schools, CA.

    Presented in booklet and chart form is the Behavioral Characteristics Progression (BCP), part of the Santa Cruz Special Education Management Project, consisting of 2400 observable traits grouped into 50 behavioral strands. The BCP is seen to be a nonstandardized criterion referenced tool which replaces conventional age and disability labels with…

  3. Holistically Evaluating the Impact of Water and Land Use Management in the Santa Cruz Watershed

    EPA Science Inventory

    Governments, tribal leaders and citizens within the Santa Cruz watershed (United States, Mexico, the Tohono O'odham and the Pascua Yaqui Tribes) face environmental and economic issues of ensuring people have access to clean water and sanitation while vital ecosystems are protect...

  4. Metasomatism in the lithospheric mantle beneath southern Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Kolosova-Satlberger, Olesya; Ntaflos, Theodoros; Bjerg, Ernesto

    2014-05-01

    Mantle xenoliths from Gobernador Gregores, southern Patagonia are spinel- lherzolites, harzburgites and wherlites. A large number of the studied xenoliths have experienced cryptic and modal metasomatism. The xenoliths are mainly coarse-grained with prevalent protogranular texture but equigranular tabular and mosaic textures are present as well. Xenoliths that have undergone modal metasomatism bear hydrous phases such as amphibole, phlogopite ± apatite and melt pockets. The latter are of particular interest because of their unusually large size (up to 1 cm in diameter) and freshness. They consist of second generation olivine, clinopyroxene and spinel ± relict amphibole ± sulfides that are surrounded by a yellowish vesicular glass matrix. The melt pockets are found in amphibole- and/or phlogopite-bearing wehrlites and harzburgites as well as anhydrous lherzolites. Subhedral primary olivines enclosed by melt pockets show in the BSE images a dark grey margin up to 80 microns thick attributed to the reaction of the primatry olivine with melt. Fine grained spinel inclusions are always associated with the dark grey margin, indicating that they belong to the secong generation assemblage. There are considerable differences between first and second generation minerals found in melt pockets. While primary olivine has Fo-contents that range from 88.0 to 93.3, second generation olivines in melt pockets vary from Fo89.3 to Fo94.4. Both primary and second generation cpx are diopsides with the latter systematically enriched in TiO2. The glasses that occur in melt pockets or propagate intergranular have compositions varying from trachyandesite to phonolite. The variable composition of the glass could be attributed to host basalt infiltration and decompressional melting of amphiboles. Some of the studied xenoliths show melt propagation of two compositional different glasses crosscutting primary generation minerals and finally mixing with each other. Microprobe analyses suggest

  5. Paleomagnetism of the late Cenozoic basalts from northern Patagonia

    NASA Astrophysics Data System (ADS)

    Mena, Mabel; Ré, Guillermo H.; Haller, Miguel J.; Singer, Silvia E.; Vilas, Juan F.

    2006-10-01

    Late Cenozoic volcanic rocks outcrop in the northern Patagonia Extrandina. Lava flows, characterized as olivine and alkaline basalts, belong to intraplate volcanism. We report paleomagnetic and rock-magnetic studies carried out on Late Cenozoic basalts belonging to the Cráter, Mojón and Moreniyeu Formations. The paleomagnetic sampling comprised 75 sites in lava flows and dikes from the Cráter Formation, three sites in a lava flow from the Mojón Formation and three sites in a lava flow from the Moreniyeu Formation. Alternating field (AF) and thermal detailed demagnetization techniques were used. Most of the samples have a viscous component. The AF procedure was more effective than thermal demagnetization in destroying viscous components and in defining the characteristic remanent magnetizations. Demagnetization curves and rock-magnetic studies suggest that the main remanence carrier is Ti-poor magnetite. Radiometric K-Ar ages were performed on these basalts. The radiometric ages are 0.8±0.1 Ma from outcrops located at Cerro Fermín and 1.9±0.4 Ma from outcrops at Cerro Negro, both at the Cráter Formation. These ages suggest an early-middle Pleistocene age for the lava flows from Cerro Fermín, and a late Pliocene to early Pleistocene age for the Cerro Negro lava flows. Based on the magnetic polarity temporal scale, the Cerro Fermín lava flows have registered the beginning of the Brunhes Chron, while the Cerro Negro basalts could have been extruded during the Olduvai Subchron. The K-Ar radiometric age of the Moreniyeu Formation (1.6±0.2 Ma) suggests an early Pleistocene age for this lava flow. The reverse polarity of its virtual geomagnetic poles (VGPs) is in agreement with the predominant one during the Matuyama Chron and suggests that the Moreniyeu Formation constitutes another volcanic event clearly separate from those of the Cráter Formation. The K-Ar radiometric age of the Mojón Formation (3.3±0.4 Ma) locates it in the middle Pliocene. The VGP

  6. Last millenium environmental changes in Lake Bertrand sediments, Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Sacré, V.; Fagel, N.; Schmidt, S.; Alvarez, D.; Araneda, A.; Urrutia, R.

    2012-04-01

    Our study focuses on a multiproxy analysis of sedimentary records from Lago Bertrand (area 50 km2; 227 masl; 46°55'S 72°50'W). Three cores were retrieved during fieldtrips in 2009 and 2011 with an Uwitec gravity corer. One core was collected in the main lake (LBt09, 102 cm) and two others in a lateral extension (LBb11-A, 162 cm and LBb11-B, 156 cm). Data 210Pb and 137Cs give average sedimentation rates of 2 mm/yr for the upper core section from the main lake, allowing a decennial resolution. Our aim is to document the climatic variability during the last millennium in Northern Patagonia and its impact on the environment. Lago Bertrand is separated from a pro-glacial lake (Lago Plomo) by a morainic barrier. The sediments of this lake are mainly composed of clayed silts and very few sandy silts. In the cores from the Eastern branch of Lago Bertrand, X-ray radiographies and magnetic susceptibility profiles evidence well-defined pluri-millimetric laminations with organic-rich layers, especially in the central core section. In the main lake, X-ray radiographies show diffuse pluri-millimetric laminations while magnetic susceptibility profiles do not confirm it. The sediments of the main lake appear more homogeneous with less organic-rich layers. They are characterized by low C/N ratio (10), supporting an important aquatic productivity; high inorganic content (90-95% of the bulk sediment); two peaks in the biological silica profile; and abundant diatoms (50-100 µm). According to the age model, the changes in aquatic productivity occurred between 1700 and 1850 AD. The cores from the Eastern branch of Lago Bertrand are under investigation to confirm the extension of the sedimentological changes observed in the main lake. The main sedimentological change observed in Lago Bertrand occurs during an interval equivalent to a part of the Little Ice Age. A similar biogenic silica-rich layer was also recorded in another relatively distant lake (Lago Thompson at 45°30'S, 72°47

  7. The role of nitrification in silicate hydrolysis in soils near Santa Cruz, CA

    NASA Astrophysics Data System (ADS)

    Kyker-Snowman, E.; White, A.; Lawrence, C. R.; Schulz, M. S.

    2013-12-01

    In some ecosystems, nitrification (microbial conversion of ammonium to nitrate) may supplant carbonic acid as a source of acidity and drive silicate weathering. Recent studies have explored the impact that ammonium fertilizer addition to soils has on weathering of various mineral types (Pacheco et al. 2013) and demonstrated directly that ammonium addition to soils can increase carbonate weathering (Gandois et al. 2011). Some evidence points to a role for nitrification in silicate weathering at a series of coastal grassland terraces near Santa Cruz, CA. Weathering rates in these soils have been estimated using the byproducts of silicate hydrolysis (Cl--adjusted Na+ and other cations). If carbonic acid from dissolved CO2 is the source of acidity in silicate hydrolysis, bicarbonate should balance the cations produced during weathering. However, in the Santa Cruz soils nitrate is the dominant anion balancing cation concentrations. High concentrations of CO2 (>1%) at depths greater than 1m may provide additional support for nitrification-based silicate hydrolysis at Santa Cruz. We evaluate the role of nitrification in silicate weathering for soils from the Santa Cruz Marine Terrace Chronosequence using a column ammonium-addition experiment and a basic weathering model. The column experiment uses ammonium inputs in excess of natural inputs and measures weathering products in eluted fluids over time. The model incorporates more realistic estimates of ammonium input and explores whether the observed concentrations of cations, nitrate and CO2 seen at Santa Cruz can be explained by nitrification-driven acidity or if other inputs need to be considered. Gandois, L, Perrin, A-S, and Probst, A. 2011. Impact of nitrogenous fertiliser-induced proton release on cultivated soils with contrasting carbonate contents: A column experiment. Geochimica et Cosmochimica Acta 75 pp. 1185-1198. Pacheco, F, Landim, P, and Szocs, T. 2013. Anthropogenic impacts on mineral weathering: A

  8. The dynamics of fine-grain sediment dredged from Santa Cruz Harbor

    USGS Publications Warehouse

    Storlazzi, Curt D.; Conaway, Christopher H.; Presto, M. Katherine; Logan, Joshua B.; Cronin, Katherine; van Ormondt, Maarten; Lescinski, Jamie; Harden, E. Lynne; Lacy, Jessica R.; Tonnon, Pieter K.

    2011-01-01

    In the fall and early winter of 2009, a demonstration project was done at Santa Cruz Harbor, California, to determine if 450 m3/day of predominantly (71 percent) mud-sized sediment could be dredged from the inner portion of the harbor and discharged to the coastal ocean without significant impacts to the beach and inner shelf. During the project, more than 7600 m3 of sediment (~5400 m3 of fine-grain material) was dredged during 17 days and discharged approximately 60 m offshore of the harbor at a depth of 2 m on the inner shelf. The U.S. Geological Survey's Pacific Coastal and Marine Science Center was funded by the U.S. Army Corps of Engineers and the Santa Cruz Port District to do an integrated mapping and process study to investigate the fate of the mud-sized sediment dredged from the inner portion of Santa Cruz Harbor and to determine if any of the fine-grain material settled out on the shoreline and/or inner shelf during the fall and early winter of 2009. This was done by collecting highresolution oceanographic and sediment geochemical measurements along the shoreline and on the continental shelf of northern Monterey Bay to monitor the fine-grain sediment dredged from Santa Cruz Harbor and discharged onto the inner shelf. These in place measurements, in conjunction with beach, water column, and seabed surveys, were used as boundary and calibration information for a three-dimensional numerical circulation and sediment dynamics model to better understand the fate of the fine-grain sediment dredged from Santa Cruz Harbor and the potential consequences of disposing this type of material on the beach and on the northern Monterey Bay continental shelf.

  9. Preliminary report on geology and ground water of the Pajaro Valley area, Santa Cruz and Monterey counties, California

    USGS Publications Warehouse

    Muir, K.S.

    1972-01-01

    The Pajaro Valley area, California, covering about 120 square miles, extends from the southern part of Santa Cruz County to several miles south of the county line into Monterey County. It borders the Pacific Ocean on the west and the Santa Cruz Mountains on the east. The city of Watsonville is the largest center of population. Deposits that range in age from Pliocene to Holocene make up the ground-water reservoir. These include, from oldest to youngest, the Purisima Formation, Aromas Red Sands of Allen (1946), terrace deposits, alluvium, and dune sand. These deposits underlie an area of about 80 square miles and have a maximum thickness of about 4,000 feet. The alluvium yields most of the water pumped from wells in the area. Pre-Pliocene rocks underlie and form the boundaries of the ground-water reservoir. These rocks contain ground water in fractures and in sandstone beds. However, they are not an important source of ground water. There is close continuity between the geology of the Pajaro Valley area and that of the Soquel-Aptos area, which is contiguous on the north. Ground water in the Pajaro Valley area is derived from three sources: (1) Precipitation within the Pajaro Valley area that reaches the ground-water body by direct infiltration or by seepage from streams, (2) seepage from the Pajaro River as it crosses the Pajaro Valley carrying runoff which originates upstream from the valley, and (3) precipitation in the Soquel-Aptos area that infiltrates and then moves southeastward at depth into the Pajaro Valley area. Ground water in most wells in the Pajaro Valley area occurs under confined (artesian) conditions; the only exception is ground water in the upper, near-surface part of the alluvium and that in the dune sand. It moves south from the north part of the area and southwest away from the San Andreas fault toward and out under Monterey Bay. In the south part of the area, ground-water movement is almost due west. The San Andreas fault probably is the only

  10. Mosasaurs (Reptilia) from the late Maastrichtian (Late Cretaceous) of northern Patagonia (Río Negro, Argentina)

    NASA Astrophysics Data System (ADS)

    Fernández, Marta; Martin, James; Casadío, Silvio

    2008-03-01

    A diverse assemblage of mosasaurs was recently recovered from the Jagüel Formation (late Maastrichtian) exposed at three localities of northern Patagonia (Río Negro, Argentina). Four taxa (three mosasaurines and a plioplatecarpine) have been identified, and three of these marine reptiles can be identified at lower taxonomic levels: Mosasaurus sp. aff. M. hoffmanni, Plioplatecarpus sp., and Prognathodon sp. These occurrences are significant because they represent the first diagnostic material at generic level exhumed from Patagonia and include one of the youngest mosasaurs found worldwide. One of the specimens described herein was found only 1.5 m below the Cretaceous/Tertiary boundary. Only mosasaurs from Antarctica found within a meter of the boundary are known to occur higher in the geologic section.

  11. SRTM Anaglyph: Meseta de Somuncura, Patagonia, Argentina (Near Los Menucos)

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Meseta de Somuncura is a semi-arid basalt plateau in northern Patagonia. This view of the northwestern part of the plateau, near Los Menucos, Argentina, shows numerous depressions where the upper basalt layers are missing or collapsed. Collapse occurs above voids in the underlying rock. These voids might have been caused by lava tubes carrying away molten lava from under the cooled and solidified surface of a lava flow. Alternatively, voids might result when ground water dissolves carbonate (limestone) or evaporite (salt) deposits that the lava may be covering.

    Many of the depressions have salty lakes. Light wind streaks downwind (eastward) from the lakes show that salt crystals blow off the lake beds during dry times. Some eroded sand and silt debris from the basalt must also blow downwind, but the degree to which wind plays a role in the erosion of the depressions is not clear.

    This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar Topography Mission, then producing the two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, South Dakota.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11

  12. SRTM Stereo Pair: Meseta de Somuncura, Patagonia, Argentina

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Meseta de Somuncura is a semi-arid basalt plateau in northern Patagonia. This view of the northwestern part of the plateau, near Los Menucos, Argentina, shows numerous depressions where the upper basalt layers are missing or collapsed. Collapse occurs above voids in the underlying rock. These voids might have been caused by lava tubes carrying away molten lava from under the cooled and solidified surface of a lava flow. Alternatively, voids might result when ground water dissolves carbonate (limestone) or evaporite (salt) deposits that the lava may be covering.

    Many of the depressions have salty lakes. Light wind streaks downwind (eastward) from the lakes show that salt crystals blow off the lake beds during dry times. Some eroded sand and silt debris from the basalt must also blow downwind, but the degree to which wind plays a role in the erosion of the depressions is not clear.

    This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with an enhanced Landsat 7satellite color image. The topography data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

    Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, South Dakota.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission

  13. Holocene sediment accumulation rates in fjords and bays of Chilean Patagonia and the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Wellner, J. S.; Anderson, J. B.; Milliken, K.; Fernandez, R.; Michalchuk, B.; Boyd, B.

    2007-12-01

    Beginning in 2005 and ending in May of 2007, we completed a series of four research cruises in the fjords and bays of Chilean Patagonia and the Antarctic Peninsula aimed, in part, at determining the style and rate of Holocene sediment accumulation in a range of glacial settings. Our original hypothesis stated that rates of glacial erosion are a function of sliding speed, and are therefore expected to diminish sharply as basal temperatures drop below the melting point. To test this hypothesis, we measured sediment accumulation in tidewater glacier fjords ranging from fast-moving temperate glaciers in Patagonia to slower moving polar glaciers on the Antarctic Peninsula. Four fjords were surveyed in Patagonia ranging from San Rafael fjord in the Northern Patagonia ice field to Marinelli fjord in Tierra del Fuego. The cruises to the Antarctic Peninsula included two SHALDRIL legs during which drill cores recovered 108 m and 80 m of Holocene sediment in Maxwell Bay, South Shetland Islands, and the Firth of Tay in the northwestern Weddell Sea, respectively. An additional nine fjords across the northern peninsula were surveyed with kasten and jumbo piston cores. To date, we have completed nearly 100 radiocarbon dates from fossil carbonate material, both shells and foraminifera, extracted from the sediment cores obtained in these fjords. Our initial results highlight the complexity of the controls on sediment yields and the extreme variability in sediment accumulation amongst fjords. While climate may be the first order control on glacier erosion rates and sediment transport to bays and fjords, several other factors must significantly influence these processes and may mask the broader signal. Our ongoing work with this newly acquired comprehensive dataset is examining additional controls including drainage basin size, precipitation gradient, altitude of the glaciers, and glacial substrate.

  14. U-Th and 10Be constraints on sediment recycling in proglacial settings, Lago Buenos Aires, Patagonia

    NASA Astrophysics Data System (ADS)

    Cogez, Antoine; Herman, Frédéric; Pelt, Eric; Norton, Kevin; Darvill, Christopher; Christl, Marcus; Morvan, Gilles; Reuschlé, Thierry; Chabaux, François

    2016-04-01

    The sedimentary cycle includes the formation by erosion of rocks, transport and deposition. While erosion and deposition can be documented, the history of sediments between the time it is extracted from the rocks and ultimately deposited into basins remains a major challenge. However, the mechanism of transfer and alteration of the sediments during transport plays a key role in the evolution of basins, feedbacks between erosion and climate, and glacial-interglacial variability of sediment transport and weathering. This is particularly true in proglacial settings because large overdeepenings, in particular, are potential sediment traps for which the efficiency at evacuating those sediments is largely unknown. The Lago Buenos Aires moraines in Patagonia are particularly interesting because they are imbricated from the older in the outer part to the younger in the inner part of the system. We sampled fine grained sediments from these moraines and measured U-Th isotopes in the 4-50 μm silicate fraction. Deposition ages were refined using 10Be exposure ages. We show first that the comminution ages model can be improved by measuring also Th isotopes, from which weathering rates can be deduced. Moreover we show from our data that there is a time lag of 300 kyr on average between erosion and deposition in the moraine. This could be attributed to the long residence time of sediments in the lake overdeepening. This conclusion raises perspectives about the transport times and dynamic of the sediments during a whole sedimentary cycle, and the subsequent effect on weathering. This conclusion could also contradict some assumptions commonly made for our erosion rates/sediment fluxes reconstructions based on river sediments analysis, in recently deglaciated catchments.

  15. Assessment of Argentinean Patagonia pollution: PBDEs, OCPs and PCBs in different matrices from the Río Negro basin.

    PubMed

    Miglioranza, Karina S B; Gonzalez, Mariana; Ondarza, Paola M; Shimabukuro, Valeria M; Isla, Federico I; Fillmann, Gilberto; Aizpún, Julia E; Moreno, Víctor J

    2013-05-01

    This work reports the occurrence and distribution of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in soil, sediment, suspended particle matter (SPM), streamwater and macrophytes, along the Río Negro basin, Argentinean Patagonia. The clear predominance of OCPs among all matrices indicates the impact of agriculture on the watershed. The highest levels were found for pp'-DDE which represented up to 95% in agricultural soils (42.0-1.27x10(3) ng/g d.w) from the Upper Valley (upstream), where long and historical intensive fruit cultures have been settled and represent a hot spot of legacy pesticides for the environment. The insecticide endosulfan, currently in use, was also found in all matrices. Levels ranged between 0.3 and 708.0 ng/g d.w, being the highest concentrations those of SPM from the Middle Valley, just before the delta area, where pesticides would be retained leading to lower concentrations as was observed downstream. PCB (#153, 138, 110, 101) and PBDE (BDE-47) levels were directly related with the presence of hydroelectric power plants, dams and dumping sites, mainly settled in the Upper Valley (0.8 ng/g and 15.1 ng/g d.w for PBDEs and PCBs, respectively). Although there was a decreasing gradient of these pollutant concentrations through the river flow, downstream urban areas enhanced PCB concentrations in the aquatic environment. More efforts and monitoring programs are highly required to control and reduce soil erosion in order to prevent the availability of forbidden pollutants in the environment.

  16. [Survival capacity of Corynebacterium pseudotuberculosis biovar ovis in different soil types from Chubut, Argentine Patagonia].

    PubMed

    Alvarez, Laura; William, Aillin; Castro, Isabel; Valenzuela, Fernanda; Estevao Belchior, Silvia

    Corynebacterium pseudotuberculosis is transmitted among sheep in Argentine Patagonia causing pseudotuberculosis. The bacterium penetrates the skin or mucous membrane wounds, infecting the superficial lymph nodes and viscera. When surface abscesses are cut during shearing, they drain their purulent contents and contaminate tools and the soil. The objective of this work was to evaluate the survival capacity of C. pseudotuberculosis over time, in soils from the extra-Andean Patagonia region. Five types of superficial soils were collected from different areas in Chubut province (extra-Andean Patagonia), having distinctive physicochemical properties including organic matter content (very high to nonexistent), pH (neutral to strongly alkaline), electrical conductivity (saline to non-saline) and texture (sandy, clayey, silty loam). Different aliquots of each type of soil were inoculated with C. pseudotuberculosis PAT10 strain isolated from a Patagonian sheep, and were stored at room temperature. The number of surviving bacteria was determined at various times. Sixty percent (60%) of the inoculated C. pseudotuberculosis population survived for 80 to 210 days in soils with moderate to high organic matter content respectively. Silty soils favored bacterial survival, whereas the variables pH and salinity had no effect on survival.

  17. Pomacea canaliculata (Mollusca, Gastropoda) in Patagonia: potential role of climatic change in its dispersion and settlement.

    PubMed

    Darrigran, G; Damborenea, C; Tambussi, A

    2011-02-01

    Pomacea canaliculata (Lamarck, 1822) (Mollusca Gastropoda) shows a large native distribution range in South America, reaching as far south as 37º S (Buenos Aires, Argentina). This species was deliberately introduced into Southeast Asia around 1980 and subsequently underwent a rapid intentional or accidental dispersal into many countries in the region. It was also introduced into North and Central America and Hawaii. In this contribution we record the presence of P. canaliculata in Patagonia, assessing the possible influence of climatic change in the new establishment of this species there. Three samplings (between September 2004 and April 2005) were carried out at 38º 58' 20.2" S-68º 11' 27.3" W. In the sampling we found two adult specimens of P. canaliculata and numerous egg clutches. Pomacea canaliculata is naturally distributed in the Plata and Amazon Basins. The southern boundary of this species has been established as the isotherms of 14 ºC and 16 ºC in Buenos Aires province, and precipitations of 900 to 600 mm/year. This study also analysed variations in annual temperature and precipitation in Patagonia. Average temperatures show an increase over the years, although not constantly. Important modifications in precipitation regime in northern Patagonia, triggered by global climatic changes, could be beneficial for the settlement of populations of P. canaliculata in this new area, where precipitation increased enough to reach values similar to those in the southernmost area of distribution of this species.

  18. Cretaceous/Paleogene floral turnover in Patagonia: drop in diversity, low extinction, and a Classopollis spike.

    PubMed

    Barreda, Viviana D; Cúneo, Nestor R; Wilf, Peter; Currano, Ellen D; Scasso, Roberto A; Brinkhuis, Henk

    2012-01-01

    Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of nearly all plant groups across the K/Pg interval. Minimum diversity occurs during the earliest Danian, but only a few palynomorphs show true extinctions. The low extinction rate is similar to previous observations from New Zealand. The differing responses between the Southern and Northern hemispheres could be related to the attenuation of damage with increased distance from the impact site, to hemispheric differences in extinction severity, or to both effects. Legacy effects of the terminal Cretaceous event also provide a plausible, partial explanation for the fact that Paleocene and Eocene macrofloras from Patagonia are among the most diverse known globally. Also of great interest, earliest Danian assemblages are dominated by the gymnosperm palynomorphs Classopollis of the extinct Mesozoic conifer family Cheirolepidiaceae. The expansion of Classopollis after the boundary in Patagonia is another example of typically Mesozoic plant lineages surviving into the Cenozoic in southern Gondwanan areas, and this greatly supports previous hypotheses of high latitude southern regions as biodiversity refugia during the end-Cretaceous global crisis.

  19. Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike

    PubMed Central

    Barreda, Viviana D.; Cúneo, Nestor R.; Wilf, Peter; Currano, Ellen D.; Scasso, Roberto A.; Brinkhuis, Henk

    2012-01-01

    Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of nearly all plant groups across the K/Pg interval. Minimum diversity occurs during the earliest Danian, but only a few palynomorphs show true extinctions. The low extinction rate is similar to previous observations from New Zealand. The differing responses between the Southern and Northern hemispheres could be related to the attenuation of damage with increased distance from the impact site, to hemispheric differences in extinction severity, or to both effects. Legacy effects of the terminal Cretaceous event also provide a plausible, partial explanation for the fact that Paleocene and Eocene macrofloras from Patagonia are among the most diverse known globally. Also of great interest, earliest Danian assemblages are dominated by the gymnosperm palynomorphs Classopollis of the extinct Mesozoic conifer family Cheirolepidiaceae. The expansion of Classopollis after the boundary in Patagonia is another example of typically Mesozoic plant lineages surviving into the Cenozoic in southern Gondwanan areas, and this greatly supports previous hypotheses of high latitude southern regions as biodiversity refugia during the end-Cretaceous global crisis. PMID:23285049

  20. Diplodon shells from Northwest Patagonia as continental proxy archives: Oxygen isotopic results and sclerochronological analyses

    NASA Astrophysics Data System (ADS)

    Soldati, A. L.; Beierlein, L.; Jacob, D. E.

    2009-04-01

    Freshwater mussels of the genus Diplodon (Bivalvia, Hyriidae) are the most abundant bivalve (today and in the past) in freshwater bodies at both sides of the South-Andean Cordillera. There are about 25 different Diplodon genera in Argentina and Chile that could be assigned almost completely to the species Diplodon chilensis (Gray, 1828) and two subspecies: D. ch. chilensis and D. ch. patagonicus; this latter species is found in Argentina between Mendoza (32˚ 52' S; 68˚ 51' W) and Chubut (45˚ 51' S; 67˚ 28' W), including the lakes and rivers of the target area, the Nahuel Huapi National Park (Castellanos, 1960). Despite their wide geographic distribution, Diplodon species have only rarely been used as climate archives in the southern hemisphere. Kaandorp et al. (2005) demonstrated for Diplodon longulus (Conrad 1874) collected from the Peruvian Amazonas that oxygen isotopic patterns in the shells could be used in order to reconstruct the precipitation regime and dry/wet seasonal of the monsoonal system in Amazonia. Although this study demonstrated the potential of Diplodon in climatological and ecological reconstructions in the southern hemisphere, as of yet, no systematic study of Diplodon as a multi-proxy archive has been undertaken for the Patagonian region. In this work we present sclerochronological analyses supported by ^18Oshell in recent mussel of Diplodon chilensis patagonicus (D'Orbigny, 1835) collected at Laguna El Trébol (42°S-71°W, Patagonia Argentina), one of the best studied water bodies in the region for paleoclimate analysis. Water temperature was measured every six hours for one year using a temperature sensor (Starmon mini®) placed at 5m depth in the lake, close to a mussel bank. Additionally, ^18Owater was measured monthly for the same time range.g^18Oshell values obtained by micro-milling at high spatial resolution in the growth increments of three Diplodon shells were compared to these records, and to air temperature and

  1. [A critical appraisal of an institutional journal: Memórias do Instituto Oswaldo Cruz].

    PubMed

    de Lemos, A A

    1993-01-01

    The journal Memórias do Instituto Oswaldo Cruz, founded and maintained over the course of many years for the exclusive publication of research results from one single institution, has undergone changes over the last decade which have resulted in an open journal. Conditions leading to the journal's founding and the excellent role it has played in the dissemination of knowledge produced by the Instituto Oswaldo Cruz are examined. The fact that it has differed from journals published by scientific societies does not diminish its importance. The present option to give this journal an international slant, with possibilities for competing on the foreign market, and which would be facilitated by the preference given to papers written in English, raises some questions about the role of Brazilian specialized journals within the framework of our scientific development.

  2. Population size of island loggerhead shrikes on Santa Rosa and Santa Cruz Islands

    USGS Publications Warehouse

    Stanley, Thomas R.; Teel, Susan; Hall, Linnea S.; Dye, Linda C.; Laughrin, Lyndal L.

    2012-01-01

    Island loggerhead shrikes (Lanius ludovicianus anthonyi) are an endemic, genetically distinct subspecies of loggerhead shrike on California's Santa Rosa, Santa Cruz, and Santa Catalina Islands (USA). This subspecies is listed as a Species of Special Concern by the California Department of Fish and Game and has been petitioned for federal listing under the Endangered Species Act. The combination of suspected low numbers and the possibility of federal listing, prompted us to undertake a study to rigorously estimate the number of remaining individuals on Santa Rosa and Santa Cruz Islands. During the 2009 and 2010 breeding seasons, we surveyed sample units on Santa Rosa and Santa Cruz Islands using a double-observer method with independent observers to estimate joint detection probabilities (p), where we selected units under a stratified random sampling design. We estimated shrike abundance to be 169 in 2009 (p = 0.476) and 240 in 2010 (p = 0.825) for Santa Rosa Island, and 35 in 2009 (p = 0.816) and 42 in 2010 (p = 0.710) for Santa Cruz Island. These numbers, especially for Santa Rosa Island, are higher than previously reported but nevertheless are still low. Rapid vegetation change on both islands due to recent removal of nonnative herbivores may threaten the habitat and status of this subspecies and, therefore, we suggest that intensive demographic and habitat use research be initiated immediately to obtain additional information vital for the management of this subspecies. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  3. Field-trip guide to the geology of the Lexington Reservoir and Loma Prieta areas in the Santa Cruz Mountains, Santa Clara and Santa Cruz counties, California

    USGS Publications Warehouse

    Stoffer, Philip W.; Messina, Paula

    2002-01-01

    This guide contains a road log and five stop descriptions for a field trip in the southern Santa Cruz Mountains. The trip officially begins at the boat dock parking area on Alma Bridge Road near the dam of Lexington Reservoir. Stop 1 involves a walk up the Limekiln Trail to examine a large landslide in serpentinite that frequently takes out the trail. Stop 2 is at Miller Point picnic area along the shore of the reservoir where exposures of massive, fractured graywacke sandstone are capped with terrace gravel deposits. Stop 3 is along Highland Way in the Santa Cruz Mountains where large landslides have occasionally force the closure of the road. Stop 4A-C are several closely spaced outcrop areas along Loma Prieta Avenue and Summit-Mt. Madonna Road in the Loma Prieta summit area. A walk to scenic vista points provide opportunity to discuss the evolution of regional landscape along the crest of the Sierra Azul. In addition, a variety of rock types are exposed in the Stop 4 area along a series of road cuts, including Cretaceous age conglomerate, turbidites (consisting of interbedded sandstone and shale), and fossiliferous mudstone. Stop 5 involves returning to the boat dock parking area to examine geology and the placement of the Lexington Dam in the Los Gatos Creek canyon.

  4. Evidence for latest Pleistocene to Holocene movement on the Santa Cruz Island fault, California

    SciTech Connect

    Pinter, N.; Sorlien, C. )

    1991-09-01

    Timing of the latest movement on the Santa Cruz Island fault, a dramatic physiographic feature of the southern boundary of the California Transverse Ranges, is demonstrated to be latest Pleistocene to Holocene in age. Faulting of dated terrace gravels confirms that the most recent rupture on the fault is no older than 11.78 {plus minus}0.1 ka. This represents an order of magnitude increase over the recency suggested by previous work and requires proportional increases in estimates of the minimum slip rate and seismic hazard posed by the fault. Uplifted latest Pleistocene to Holocene fill terraces are consistent with models of high rates of uplift and high sediment supply. Numerical solution of the interaction of sea-level rise with uplift at the west end of Santa Cruz Island predicts that the youngest strata in the faulted terrace sequence are about 6.1 ka. Reevaluation of high-resolution seismic sections just west of the island supports the latest Pleistocene to Holocene timing of the most recent rupture on the fault. The Santa Cruz Island fault apparently represents an active seismogenic element of southern California, the recent and high rate of activity of which have not been previously recognized.

  5. Hantavirus Pulmonary Syndrome in Santa Cruz, Bolivia: Outbreak Investigation and Antibody Prevalence Study

    PubMed Central

    Montgomery, Joel M.; Blair, Patrick J.; Carroll, Darin S.; Mills, James N.; Gianella, Alberto; Iihoshi, Naomi; Briggiler, Ana M.; Felices, Vidal; Salazar, Milagros; Olson, James G.; Glabman, Raisa A.; Bausch, Daniel G.

    2012-01-01

    We report the results of an investigation of a small outbreak of hantavirus pulmonary syndrome in 2002 in the Department of Santa Cruz, Bolivia, where the disease had not previously been reported. Two cases were initially reported. The first case was a physician infected with Laguna Negra virus during a weekend visit to his ranch. Four other persons living on the ranch were IgM antibody-positive, two of whom were symptomatic for mild hantavirus pulmonary syndrome. The second case was a migrant sugarcane worker. Although no sample remained to determine the specific infecting hantavirus, a virus 90% homologous with Río Mamoré virus was previously found in small-eared pygmy rice rats (Oligoryzomys microtis) trapped in the area. An antibody prevalence study conducted in the region as part of the outbreak investigation showed 45 (9.1%) of 494 persons to be IgG positive, illustrating that hantavirus infection is common in Santa Cruz Department. Precipitation in the months preceding the outbreak was particularly heavy in comparison to other years, suggesting a possible climatic or ecological influence on rodent populations and risk of hantavirus transmission to humans. Hantavirus infection appears to be common in the Santa Cruz Department, but more comprehensive surveillance and field studies are needed to fully understand the epidemiology and risk to humans. PMID:23094116

  6. Hantavirus pulmonary syndrome in Santa Cruz, Bolivia: outbreak investigation and antibody prevalence study.

    PubMed

    Montgomery, Joel M; Blair, Patrick J; Carroll, Darin S; Mills, James N; Gianella, Alberto; Iihoshi, Naomi; Briggiler, Ana M; Felices, Vidal; Salazar, Milagros; Olson, James G; Glabman, Raisa A; Bausch, Daniel G

    2012-01-01

    We report the results of an investigation of a small outbreak of hantavirus pulmonary syndrome in 2002 in the Department of Santa Cruz, Bolivia, where the disease had not previously been reported. Two cases were initially reported. The first case was a physician infected with Laguna Negra virus during a weekend visit to his ranch. Four other persons living on the ranch were IgM antibody-positive, two of whom were symptomatic for mild hantavirus pulmonary syndrome. The second case was a migrant sugarcane worker. Although no sample remained to determine the specific infecting hantavirus, a virus 90% homologous with Río Mamoré virus was previously found in small-eared pygmy rice rats (Oligoryzomys microtis) trapped in the area. An antibody prevalence study conducted in the region as part of the outbreak investigation showed 45 (9.1%) of 494 persons to be IgG positive, illustrating that hantavirus infection is common in Santa Cruz Department. Precipitation in the months preceding the outbreak was particularly heavy in comparison to other years, suggesting a possible climatic or ecological influence on rodent populations and risk of hantavirus transmission to humans. Hantavirus infection appears to be common in the Santa Cruz Department, but more comprehensive surveillance and field studies are needed to fully understand the epidemiology and risk to humans.

  7. Estimating the population size of island loggerhead shrikes on Santa Rosa and Santa Cruz Islands, USA

    USGS Publications Warehouse

    Stanley, Thomas R.; Teel, Susan; Hall, Linnea S.; Dye, Linda C.; Laughrin, Lyndal L.

    2012-01-01

    Island loggerhead shrikes (Lanius ludovicianus anthonyi) are an endemic, genetically distinct subspecies of loggerhead shrike on California’s Santa Rosa and Santa Cruz Islands. This subspecies is listed as a Species of Special Concern by the California Department of Fish and Game and has been petitioned for federal listing under the Endangered Species Act. Because of suspected low numbers and the possibility of federal listing, there was an urgent need to rigorously estimate the number of remaining individuals on the Islands. In 2009 and 2010, biologists from the U.S. Geological Survey and the National Park Service surveyed sample units on Santa Rosa and Santa Cruz Islands using a double-observer method with independent observers, where units were selected under a stratified random sampling design. Shrike abundance was estimated to be 169 in 2009 and 240 in 2010 for Santa Rosa Island, and 35 in 2009 and 42 in 2010 for Santa Cruz Island. These numbers, especially for Santa Rosa Island, are higher than previously reported but nevertheless are still low. Rapid vegetation change on both islands due to recent removal of non-native herbivores may threaten the habitat and status of this subspecies. In view of this circumstance and the still-low numbers of shrikes, additional intensive demographic and habitat-use studies are critical for obtaining information vital for the perpetuation of this subspecies.

  8. A large and complete Jurassic geothermal field at Claudia, Deseado Massif, Santa Cruz, Argentina

    NASA Astrophysics Data System (ADS)

    Guido, Diego M.; Campbell, Kathleen A.

    2014-04-01

    Late Jurassic geothermal deposits at Claudia, Argentinean Patagonia, are among the largest (40 km2) and most varied in the Deseado Massif, a 60,000 km2 volcanic province hosting precious metals (Au, Ag) mineralization generated during diffuse back arc spreading and opening of the South Atlantic Ocean. Both siliceous sinter and travertine occur in the same stratigraphic sequence. Deposits range from those interpreted as fluvially reworked hydrothermal silica gels, to extensive apron terraces, to a clustering of high-temperature subaerial vent mounds. Paleoenvironmentally diagnostic textures of sinters include wavy laminated, bubble mat and nodular fabrics, and for travertines comprise fossil terracette rims, wavy laminated, bubble mat, spherulitic, oncoidal, and peloidal fabrics. Of special note is the presence of relatively large (to 25 cm high), inferred subaqueous "Conophyton" structures in travertines, which serve as analogs for some Precambrian stromatolites and imply the presence of relatively deep pools maintained by voluminous spring discharges. The Claudia geothermal field is geographically and geologically linked to the Cerro Vanguardia epithermal project (total resource of ~ 7.8 million ounces Au equivalent) via proximity, similar veins, and structural linkages, making it an especially large and relevant prospect for the region. The combined Claudia-Cerro Vanguardia hydrothermal system likely represents a fortuitous alignment of focused fluid flow and structure conducive to forming a giant epithermal ore deposit, with respect to size, ore concentration and potentially duration, in the Late Jurassic of Patagonia.

  9. Detecting allocyclic signals in volcaniclastic fluvial successions: Facies, architecture and stacking pattern from the Cretaceous of central Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Umazano, Aldo M.; Bellosi, Eduardo S.; Visconti, Graciela; Melchor, Ricardo N.

    2012-12-01

    The Castillo Formation and the overlying lower member of the Bajo Barreal Formation (Cretaceous) are the principal hydrocarbon-producing units of the San Jorge Basin, Patagonia, Argentina. They are mainly composed of sandstone lenses interbedded with finer-grained, tuffaceous, sheet-like strata. Both units record fluvial systems influenced by voluminous pyroclastic influx via ash-falls mainly from a western source. These fluvial systems drained from the west toward a non-marine depocenter located in the eastern part of the basin. The units were studied in the Sierra de San Bernardo, a NNW-SSE oriented fold and thrust belt located in the western sector of the basin. The objectives of this study were: (i) to assess the influence of allocyclic factors on fluvial dynamics and sedimentation, and (ii) to determine the possible link between changes in tephra reworking and configuration of channel belts. The methodology included facies and architectural analyses, as well as determination of the stacking pattern of the channel deposits. The Castillo Formation represents permanent single-channel rivers with channel-margin bars. Floodplains were commonly constructed from aqueous reworking of pyroclastic substrates (sheet-floods, debris-flows and shallow lacustrine sedimentation) and, to a lesser extent, by preservation of ash-fall deposits. The lower member of the Bajo Barreal Formation generally records braided fluvial channel belts with a more variable water discharge and, in one locality, single-channeled rivers. Constructive processes of the floodplains were similar to the underlying Castillo Formation, although other types of deposits were detected in lower proportions including hyperconcentrated flows and crevasse-splays. The different pyroclastic sediment supply between both units explains the general evolution of the fluvial systems. The stacking patterns, which are a response to base-level changes, are probably associated with the common tectonic activity recorded in

  10. A promising location in Patagonia for paleoclimate and paleoenvironmental reconstructions revealed by a shallow firn core from Monte San Valentín (Northern Patagonia Icefield, Chile)

    NASA Astrophysics Data System (ADS)

    Vimeux, FrançOise; de Angelis, Martine; Ginot, Patrick; Magand, Olivier; Casassa, Gino; Pouyaud, Bernard; Falourd, Sonia; Johnsen, Sigfus

    2008-08-01

    The study of past climate variability from ice core investigations has been largely developed both in polar areas over the past decades and, more recently, in tropical regions, specifically along the South American Andes between 0° and 20°S. However a large gap still remains at mid-latitudes in the Southern Hemisphere. In this framework, a 15.3-m long shallow firn core has been extracted in March 2005 from the summit plateau of Monte San Valentín (3747 m, 46°35'S, 73°19'W) in the Northern Patagonia Icefield to test its potential for paleoclimate and paleoenvironmental reconstructions. The firn temperature is -11.9°C at 10-m depth allowing to expect well preserved both chemical and isotopic signals, unperturbed by water percolation. The dating of the core, on the basis of a multi-proxy approach combining annual layer counting and radionuclide measurements, shows that past environment and climate can be reconstructed back to the mid-1960s. A mean annual snow accumulation rate of 36 ± 3 cm year-1 (i.e., 19 ± 2 g cm-2 year-1) is inferred, with a snow density varying between 0.35 and 0.6 g cm-3, which is much lower than accumulation rates previously reported in Patagonia at lower elevations. Here, we present and discuss high-resolution profiles of the isotopic composition of the snow and selected chemical markers. These data provide original information on environmental conditions prevailing over Southern Patagonia in terms of air masses trajectories and origins and biogeochemical reservoirs. Our main conclusion is that the San Valentín site is not only influenced by air masses originating from the southern Pacific and directly transported by the prevailing west winds but also by inputs from South American continental sources from the E-NE, sometimes mixed with circumpolar aged air masses, the relative influence of these two very distinct source areas changing at the interannual timescale. Thus this site should offer a wealth of information regarding (South

  11. Physical data of soil profiles formed on late Quaternary marine terraces near Santa Cruz, California

    USGS Publications Warehouse

    Munster, Jennie; Harden, Jennifer W.

    2002-01-01

    The marine terraces in and around Santa Cruz, California, represent a set of well-preserved terraces formed as a product of geology, sea level, and climate. A marine terrace begins as a wave cut platform. Eustatic sea level changes, seacliff erosion, and tectonic uplift work together to generate marine terraces. "When a wave-cut platform is raised (due to tectonic activity) above sea level and cliffed by wave action it becomes a marine terrace" (Bradley, 1957, p. 424). During glacial periods, eustatic sea level is estimated to have dropped by 150 meters (Fairbanks, 1989). Cliff retreat measured from aerial photographs between 1930 and 1980 vary from 0.0 to 0.2 m yr–1 (Best and Griggs, 1991). Estimates of uplift rates along the Santa Cruz coastline vary from 0.10 to 0.48 m kyr–1 (Bradley and Griggs, 1976; Weber and others, 1999). Uplift mechanisms include coseismic uplift associated both with a reverse component of slip on the steeply SW dipping Loma Prieta fault in the restraining bend of the San Andreas Fault and a small component of reverse slip on the steeply SE dipping San Gregorio fault (Anderson and Menking 1994). Previous work studying physical properties on these terraces include Pinney and others (in press) and Aniku (1986) and Bowman and Estrada (1980). Sedimentary deposits of the marine terraces are a mixture of terrestrial and marine sediments but generally consist of a sheet of marine deposits overlying the old platform and a wedge of nonmarine deposits banked against the old sea cliff (Bradley, 1957). Bedrock underlying the terraces in the Santa Cruz area is generally either Santa Margarita Sandstone or Santa Cruz Mudstone. The Santa Margarita Sandstone represents an upper Miocene, transgressive, tidally dominated marine-shelf deposit with crossbedded sets of sand and gravel and horizontally stratified and bioturbated invertebrate-fossils beds (Phillips, 1990). The siliceous Santa Cruz Mudstone, of late Miocene age, conformably overlies the Santa

  12. Geomorphical and Geochronological Constrains of the Last Glacial Period in Southern Patagonia, Southern South America

    NASA Astrophysics Data System (ADS)

    García, J.; Hall, B. L.; Kaplan, M. R.; Vega, R. M.; Binnie, S. A.; Hein, A.; Gómez, G. N.; Ferrada, J. J.

    2013-12-01

    Despite the outer limits of the former Patagonian ice sheet (PIS, ~38-55S) having been extensively mapped, it remains unknown if the Patagonian glaciers fluctuated synchronously or asynchronously during the last glacial period. Previous work has revealed asynchronous spatiotemporal ice dynamics along the eastern and western ice-margins at the end of the last glaciation but it is not well understood if the northern and southern parts of the PIS reached concurrent maximum glaciation during the last glacial cycle. The Patagonian Andes is the only landmass involving the southern westerly wind belt latitudinal range, which is thought to have played a key role in past glacial and climate changes. Therefore, reconstructing southern Andes glacier history constitutes a key element for understanding the cause of glaciations in Patagonia and the role of the westerlies in climate change. Here, we discuss paleoglaciological and paleoclimatological implications of new 10Be and 14C data obtained from moraines and strategically selected mires in two contiguous glacially molded basins of south Patagonia (48-55S): Torres del Paine (51S) and Última Esperanza (52S). In this region, we focused our 10Be cosmogenic-dating efforts in the previously undated outer moraines deposited (supposedly) during the last glacial cycle. In order to crosscheck cosmogenic data we collected boulders embedded in moraines and cobbles from the main glaciofluvial plains grading from the outermost moraines. Geomorphic and cosmogenic dating affords evidence for glacial maximum conditions occurring between 40-50 ka (ka = thousand of years before present) in southern Patagonia, which is different from other chronologies within southern South America. We obtained 14C basal ages from sites located within moraine depressions and on former paleolake shorelines and thus these may provide key data on deglaciation and debated regional paleolake history.

  13. Extensive MIS 3 glaciation in southernmost Patagonia revealed by cosmogenic nuclide dating of outwash sediments

    NASA Astrophysics Data System (ADS)

    Darvill, Christopher M.; Bentley, Michael J.; Stokes, Chris R.; Hein, Andrew S.; Rodés, Ángel

    2015-11-01

    The timing and extent of former glacial advances can demonstrate leads and lags during periods of climatic change and their forcing, but this requires robust glacial chronologies. In parts of southernmost Patagonia, dating pre-global Last Glacial Maximum (gLGM) ice limits has proven difficult due to post-deposition processes affecting the build-up of cosmogenic nuclides in moraine boulders. Here we provide ages for the Río Cullen and San Sebastián glacial limits of the former Bahía Inútil-San Sebastián (BI-SSb) ice lobe on Tierra del Fuego (53-54°S), previously hypothesised to represent advances during Marine Isotope Stages (MIS) 12 and 10, respectively. Our approach uses cosmogenic 10Be and 26Al exposure dating, but targets glacial outwash associated with these limits and uses depth-profiles and surface cobble samples, thereby accounting for surface deflation and inheritance. The data reveal that the limits formed more recently than previously thought, giving ages of 45.6 ka (+139.9/-14.3) for the Río Cullen, and 30.1 ka (+45.6/-23.1) for the San Sebastián limits. These dates indicate extensive glaciation in southern Patagonia during MIS 3, prior to the well-constrained, but much less extensive MIS 2 (gLGM) limit. This suggests the pattern of ice advances in the region was different to northern Patagonia, with the terrestrial limits relating to the last glacial cycle, rather than progressively less extensive glaciations over hundreds of thousands of years. However, the dates are consistent with MIS 3 glaciation elsewhere in the southern mid-latitudes, and the combination of cooler summers and warmer winters with increased precipitation, may have caused extensive glaciation prior to the gLGM.

  14. Paleoenvironmental setting and description of an estuarine oyster reef in the Eocene of Patagonia, southern Argentina

    NASA Astrophysics Data System (ADS)

    Raising, Martín Rodríguez; Casadío, Silvio; Pearson, Nadine; Mángano, Gabriela; Buatois, Luis; Griffin, Miguel

    2014-12-01

    A middle Eocene Crassostrea sp. reef near Río Turbio, southwestern Patagonia (Argentina), represents the earliest record of an oyster reef associated with estuarine facies in the southern hemisphere, and also one of the few known worldwide occurring in Paleogene rocks. The reef grew in an outer estuary environment subject to periodic changes in salinity and may have reached a maturing phase. The Río Turbio reef - by its dimensions, geometry, and substrate lithology- would have been located in a tidal channel convergence area. This reef provides new evidence suggesting that estuaries served as refuges for Crassostrea populations allowing them to disperse into fully marine environments many times throughout the Cenozoic.

  15. Magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

    USGS Publications Warehouse

    Rodriguez, Brian D.; Sampson, Jay A.

    2010-01-01

    The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size and resistivity of the mineralized area beneath overburden, a regional east-west magnetotelluric sounding profile was acquired. This is a data release report of the magnetotelluric sounding data collected along the east-west profile; no interpretation of the data is included.

  16. Audio-magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

    USGS Publications Warehouse

    Sampson, Jay A.; Rodriguez, Brian D.

    2010-01-01

    The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size, resistivity, and skin depth of the polarizable mineral deposit concealed beneath thick overburden, a regional east-west audio-magnetotelluric sounding profile was acquired. The purpose of this report is to release the audio-magnetotelluric sounding data collected along that east-west profile. No interpretation of the data is included.

  17. Rime Mushrooms - Extreme Rime Ice Buildup on Mountain Summits of Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Whiteman, C. D.

    2015-12-01

    The Southern Patagonian Andes are known among mountain climbers for a meteorological phenomenon that occurs there but is unknown in many other mountain areas. The phenomenon is the buildup of rime ice in large bulbous or mushroom-shaped accretions on the windward side of projecting mountain summits, ridges and exposed near-vertical rock faces. These "ice mushrooms" have never been investigated scientifically. This talk will introduce the audience to ice mushrooms, describe where they are found, consider the meteorological factors leading to their formation, and illustrate how they are negotiated by mountain climbers using photographs and descriptions from Southern Patagonia.

  18. Hematology and serum chemistry of the island spotted skunk on Santa Cruz Island.

    PubMed

    Crooks, Kevin R; Garcelon, D K; Scott, Cheryl A; Wilcox, Jeffery T; Timm, Steven F; Van Vuren, Dirk H

    2003-04-01

    We determined serum biochemistry and hematologic values for island spotted skunks (Spilogale gracilis amphiala) on Santa Cruz Island (California, USA). Samples were collected from island spotted skunks chemically restrained with ketamine hydrochloride and acepromazine in August 1999 (dry season) and from skunks manually restrained in August 2000 (dry season) and January 2001 (wet season). One parameter, glucose, significantly differed with season, with higher levels during the wet season. Serum chemistry and hematologic profiles suggest that method of restraint (manual or chemical), as well as other methodologic details, may influence blood characteristics in the island spotted skunk.

  19. Geohydrologic Framework of Recharge and Seawater Intrusion in the Pajaro Valley, Santa Cruz and Monterey Counties, California

    USGS Publications Warehouse

    Hanson, Randall T.

    2003-01-01

    Pajaro Valley is a coastal watershed of 160 square miles located along Monterey Bay north of Elkhorn Slough and south of the city of Santa Cruz. The valley has been predominantly developed for agriculture since the late 1800s. In 1984 the Pajaro Valley Water Management Agency (PVWMA) was formed and was delegated with the responsibility of the management of the water resources within the Pajaro Valley by the State of California. About 84 percent of the water is used for agriculture and 16 percent is used for industrial and municipal water supply; almost all of the demand is supplied by ground water. Ground-water pumpage varies with seasonal and climatic periods. The alluvial aquifers are composed of Quaternary- and Tertiary-aged sediments that are layered marine and terrestrial coarse-grained deposits separated by extensive fine-grained deposits that potentially restrict vertical movement of ground water and seawater intrusion in the coastal subareas. The coarse-grained deposits, which persist over large areas, control pumpage and related seawater intrusion. The Aromas Sand crops out throughout the north and central parts of the PVWMA area and offshore on the continental shelf and in Monterey submarine canyon. Because many of the wells in the coastal and inland subregions are screened at depths of 200 to 400 feet below land surface, a direct avenue is provided for seawater intrusion through the coarse-grained deposits of the shallower alluvium and Aromas Sand. Geophysical logs from monitoring wells indicate discrete zones of saline water that are related to pumpage and seawater intrusion in the aquifers of the shallower alluvium and upper Aromas Sand in the upper-aquifer system and to deeper saline waters in the lower Aromas Sand within the lower-aquifer system. The precipitation data indicate that there were at least nine dry and nine wet periods that range from 2 to 19 years during the period of record, 1880?1997. The ground-water pumpage, runoff, streamflow and

  20. The Odonata (Insecta) of Patagonia: a synopsis of their current status with illustrated keys for their identification.

    PubMed

    Muzón, Javier; Pessacq, Pablo; Lozano, Federico

    2014-03-31

    Patagonia is a vast landmass with a distinctive environmental and biotic heterogeneity. Its Odonata biodiversity is the best known of South America, and it is composed of 36 species, of which more than 50% are endemic. We summarize the main taxonomic, distributional and biological information including illustrated keys for adults and known larvae, and distributional maps.

  1. Eastern Andean environmental and climate synthesis for the last 2000 years BP from terrestrial pollen and charcoal records of Patagonia

    NASA Astrophysics Data System (ADS)

    Sottile, G. D.; Echeverria, M. E.; Mancini, M. V.; Bianchi, M. M.; Marcos, M. A.; Bamonte, F. P.

    2015-06-01

    The Southern Hemisphere Westerly Winds (SWW) constitute an important zonal circulation system that dominates the dynamics of Southern Hemisphere mid-latitude climate. Little is known about climatic changes in the Southern South America in comparison to the Northern Hemisphere due to the low density of proxy records, and adequate chronology and sampling resolution to address environmental changes of the last 2000 years. Since 2009, new pollen and charcoal records from bog and lakes in northern and southern Patagonia at the east side of the Andes have been published with an adequate calibration of pollen assemblages related to modern vegetation and ecological behaviour. In this work we improve the chronological control of some eastern Andean previously published sequences and integrate pollen and charcoal dataset available east of the Andes to interpret possible environmental and SWW variability at centennial time scales. Through the analysis of modern and past hydric balance dynamics we compare these scenarios with other western Andean SWW sensitive proxy records for the last 2000 years. Due to the distinct precipitation regimes that exist between Northern (40-45° S) and Southern Patagonia (48-52° S) pollen sites locations, shifts on latitudinal and strength of the SWW results in large changes on hydric availability on forest and steppe communities. Therefore, we can interpret fossil pollen dataset as changes on paleohydric balance at every single site by the construction of paleohydric indices and comparison to charcoal records during the last 2000 cal yrs BP. Our composite pollen-based Northern and Southern Patagonia indices can be interpreted as changes in latitudinal variation and intensity of the SWW respectively. Dataset integration suggest poleward SWW between 2000 and 750 cal yrs BP and northward-weaker SWW during the Little Ice Age (750-200 cal yrs BP). These SWW variations are synchronous to Patagonian fire activity major shifts. We found an in phase

  2. Saccharomyces eubayanus and Saccharomyces uvarum associated with the fermentation of Araucaria araucana seeds in Patagonia.

    PubMed

    Rodríguez, M Eugenia; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Lopes, Christian A

    2014-09-01

    Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined.

  3. Episodic Jurassic to Lower Cretaceous intraplate compression in Central Patagonia during Gondwana breakup

    NASA Astrophysics Data System (ADS)

    Navarrete, César; Gianni, Guido; Echaurren, Andrés; Kingler, Federico Lince; Folguera, Andrés

    2016-12-01

    From Lower Jurassic to Lower Cretaceous, several intraplate compression events affected discrete sectors of Central Patagonia, under a general context of crustal extension associated with Gondwana breakup. This was demonstrated by means of 2D and 3D seismic and borehole data, which show partial inversion of Lower and Middle Jurassic extensional structures of the Chubut and Cañadón Asfalto basins, during the earliest stages of breakup. A comparison with surrounding areas in Patagonia, where similar Jurassic intraplate compression was described, allowed the discrimination of three discrete pulses of subtle compression (C1: ∼188-185 Ma; C2: ∼170-163; C3: ∼157-136? Ma). Interestingly, episodic intraplate compressional events are closely followed by high flux magmatic events linked to the westward expansion of the Karoo-Ferrar thermal anomaly, which impacted on the lithosphere of southwest Gondwana in Lower Jurassic. In addition, we determined the approximate direction of the main compressive strain (σ1) compatible with other Jurassic intraplate belts of South America. These observations led us to propose a linkage between a thermo mechanically weakened continental crust due to LIPs activity, changes in plate motions and ridge-push forces generated by the opening of the Weddell Sea, in order to explain intraplate shortening, interrupted while Karoo LIPs magmatic invigoration took place.

  4. Wildland-Urban Interface Fires and Socioeconomic Conditions: A Case Study of a Northwestern Patagonia City

    NASA Astrophysics Data System (ADS)

    de Torres Curth, Monica; Biscayart, Carolina; Ghermandi, Luciana; Pfister, Gabriela

    2012-04-01

    In many regions of the world, fires are primarily of anthropogenic origin. In northwestern Patagonia, the number of fires is not correlated with meteorological variables, but is concentrated in urban areas. This study was conducted in the wildland-urban interface (WUI) area of San Carlos de Bariloche (Patagonia, Argentina), within the Nahuel Huapi National Park. WUI fires are particularly problematic because, besides people and goods, they represent a danger to protected areas. We studied the relationship between fire records and socioeconomic indicators within the WUI of San Carlos de Bariloche. We conducted a Multiple Correspondence Factorial Analysis and an Ascendant Hierarchical Classification of the city neighborhoods. The results show that the neighborhoods in Bariloche can be divided into three classes: High Socioeconomic Fire Risk neighborhoods, including neighborhoods with the highest fire rates, where people have low instruction level, high levels of unsatisfied basic needs and high unemployment levels; Low Socioeconomic Fire Risk neighborhoods, that groups neighborhoods which present the opposite characterization, and Moderate Socioeconomic Fire Risk neighborhoods, which are more heterogeneous. Once neighborhoods were classified, a Socioeconomic Fire Risk map was generated, supplementing the existing WUI Fire Danger map. Our results emphasize the relevance of socioeconomic variables to fire policies.

  5. Wildland-urban interface fires and socioeconomic conditions: a case study of a northwestern Patagonia city.

    PubMed

    de Torres Curth, Monica; Biscayart, Carolina; Ghermandi, Luciana; Pfister, Gabriela

    2012-04-01

    In many regions of the world, fires are primarily of anthropogenic origin. In northwestern Patagonia, the number of fires is not correlated with meteorological variables, but is concentrated in urban areas. This study was conducted in the wildland-urban interface (WUI) area of San Carlos de Bariloche (Patagonia, Argentina), within the Nahuel Huapi National Park. WUI fires are particularly problematic because, besides people and goods, they represent a danger to protected areas. We studied the relationship between fire records and socioeconomic indicators within the WUI of San Carlos de Bariloche. We conducted a Multiple Correspondence Factorial Analysis and an Ascendant Hierarchical Classification of the city neighborhoods. The results show that the neighborhoods in Bariloche can be divided into three classes: High Socioeconomic Fire Risk neighborhoods, including neighborhoods with the highest fire rates, where people have low instruction level, high levels of unsatisfied basic needs and high unemployment levels; Low Socioeconomic Fire Risk neighborhoods, that groups neighborhoods which present the opposite characterization, and Moderate Socioeconomic Fire Risk neighborhoods, which are more heterogeneous. Once neighborhoods were classified, a Socioeconomic Fire Risk map was generated, supplementing the existing WUI Fire Danger map. Our results emphasize the relevance of socioeconomic variables to fire policies.

  6. Molecular evidence for a novel encapsulated genotype of Trichinella from Patagonia, Argentina.

    PubMed

    Krivokapich, Silvio J; Prous, Cinthia L Gonzalez; Gatti, Graciana M; Confalonieri, Viviana; Molina, Viviana; Matarasso, Hugo; Guarnera, Eduardo

    2008-10-01

    At present, Trichinella spiralis is the only species of this genus reported from South America. Herein, we detail a molecular analysis of a new encapsulated isolate of muscle larvae of Trichinella, found in a mountain lion (Puma concolor) coming from the Patagonia, Argentina. We studied three DNA regions previously probed to be useful for the identification of all eleven recognized Trichinella genotypes: expansion segment 5 (ES5), cytochrome c-oxidase subunit I (COI) and 5S ribosomal DNA intergenic spacer region (5S ISR). BLAST searches with these DNA sequences showed that the mitochondrial and nuclear ribosomal regions most closely resemble other Trichinella sequences available in GenBank. However, they did not exactly match any of the eleven recognized genotypes. The phylogenetic analysis from COI and 5S ISR sequences showed that the mountain lion isolate is grouped with encapsulated members, in concordance with morphological data. Furthermore, this new isolate was located at the base of the encapsulated genotypes, signifying that it is an old genotype that could have emerged earliest in this group. These data strongly suggest that this isolate from the Patagonia represents the twelfth genotype (T12) described in the genus Trichinella. Nevertheless, further studies are necessary to adequately establish this isolate as a unique genotype.

  7. Last glacial maximum environments in northwestern Patagonia revealed by fossil small mammals

    NASA Astrophysics Data System (ADS)

    Tammone, Mauro N.; Hajduk, Adan; Arias, Pablo; Teta, Pablo; Lacey, Eileen A.; Pardiñas, Ulyses F. J.

    2014-07-01

    Comparisons of historical and modern assemblages of mammals can yield important insights into patterns and processes of environmental change. Here, we present the first analyses of small mammal assemblages present in northern Patagonia during the last glacial maximum (LGM). Using remains obtained from owl pellets excavated from an archeological cave site (Arroyo Corral I, levels VII-V, carbon dates of 22,400-21,530 cal yr BP), we generate estimates of the minimum number of individuals for all species detected; these estimates, in turn are used to determine relative species abundances. Comparisons of these data with similar analyses of small mammal remains obtained from a second archeological site (ACoII, levels IV-V, carbon dates of 10,010-9220 cal yr BP) as well as from modern owl pellets reveal pronounced changes in relative species abundance since the LGM. In particular, Euneomys chinchilloides and Ctenomys sociabilis - the predominant species during the LGM - declined markedly, suggesting a change from open, bare habitat punctuated by patches of wet meadows and shrubs to the more densely vegetated mosaic of ecotone habitats found in this region today. These data provide important new insights into the environmental changes that have occurred in northern Patagonia over the last 20,000 years.

  8. Benthic methylmercury production in lacustrine ecosystems of Nahuel Huapi National Park, Patagonia, Argentina

    USGS Publications Warehouse

    Ribeiro, Guevara S.; Catan, S.P.; Marvin-DiPasquale, M.

    2009-01-01

    Seasonal trends of benthic methylmercury (methyl-Hg) production were examined in both littoral and open water sites of three lakes (Escondido, Moreno, and Morenito) in the North Andean Patagonia region of Argentina. Potentials of methyl-Hg production were measured by amending sediment samples with inorganic 197Hg(II), incubating for either 24 and 32 h at room temperature, and subsequently assaying the radiolabelled organomercury produced. Seasonal variations of benthic methyl-Hg production were studied but no significant correlation was observed. Lake littoral sites exhibited up to two fold higher methyl-Hg production potentials in most cases. Sediment from lakes Moreno and Morenito generally exhibited much lower (up to 10 fold) methyl-Hg production potentials than those from Lake Escondido, possibly due to differences in particulate and dissolved organic matter quantity and quality, which is higher in Lake Escondido and primarily allochthonous, whereas in lakes Moreno and Morenito is primarily autochthonous. This study represents the first to directly examine benthic microbial Hg(II)-methylation in aquatic ecosystems of Patagonia. ?? 2009 Elsevier Ltd. All rights reserved.

  9. California State Waters Map Series—Offshore of Santa Cruz, California

    USGS Publications Warehouse

    Cochrane, Guy R.; Dartnell, Peter; Johnson, Samuel Y.; Erdey, Mercedes D.; Golden, Nadine E.; Greene, H. Gary; Dieter, Bryan E.; Hartwell, Stephen R.; Ritchie, Andrew C.; Finlayson, David P.; Endris, Charles A.; Watt, Janet T.; Davenport, Clifton W.; Sliter, Ray W.; Maier, Katherine L.; Krigsman, Lisa M.; Cochrane, Guy R.; Cochran, Susan A.

    2016-03-24

    IntroductionIn 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow subsurface geology.The Offshore of Santa Cruz map area is located in central California, on the Pacific Coast about 98 km south of San Francisco. The city of Santa Cruz (population, about 63,000), the largest incorporated city in the map area and the county seat of Santa Cruz County, lies on uplifted marine terraces between the shoreline and the northwest-trending Santa Cruz Mountains, part of California’s Coast Ranges. All of California’s State Waters in the map area is part of the Monterey Bay National Marine Sanctuary.The map area is cut by an offshore section of the San Gregorio Fault Zone, and it lies about 20 kilometers southwest of the San Andreas Fault Zone. Regional folding and uplift along the coast has been attributed to a westward bend in the San Andreas Fault Zone and to right-lateral movement along the San Gregorio Fault Zone. Most of the coastal zone is characterized by low, rocky cliffs and sparse, small pocket beaches backed by low, terraced hills. Point Santa Cruz, which forms the north edge of Monterey Bay, provides protection for the beaches in the easternmost part of the map area by sheltering them from the predominantly northwesterly waves.The shelf in the map area is underlain by variable amounts (0 to 25 m) of

  10. Evaluation of ground-water monitoring network, Santa Cruz County, California

    USGS Publications Warehouse

    Blankenbaker, G.G.; Farrar, Christopher D.

    1981-01-01

    The Santa Cruz County Flood Control and Water Conservation District seeks to improve the existing network of observation wells to monitor water levels and ground-water quality in the Pajaro Valley subarea and the Aptos-Soquel, San Lorenzo, and Santa Cruz Coastal subbasins in California. The proposed network , consisting of 92 wells, is designed to monitor changes in storage and quality of ground water resulting from climatic changes and management-induced stresses. In the proposed network , water levels in all wells would be measured semiannually, in April and September, and monthly in a few key wells. The water-level measurements would provide data that could be used to determine changes in ground-water storage. In addition to the currently monitored characteristics--temperature, specific conductance, pH, and chloride ion concentration--inclusion of annual sampling and analysis for major ions and nutrients is proposed. The network would also include sampling and analysis for trace elements once every 4 years. More frequent analyses are proposed in areas where water-quality problems are known to exist or where potential water-quality problems are recognized. Analyses for major ions, nutrients, and trace elements are included in the proposed network to provide baseline data for monitoring long-term changes in water quality and to detect any unexpected changes in quality. (USGS)

  11. Biologic origin of iron nodules in a marine terrace chronosequence, Santa Cruz, California

    USGS Publications Warehouse

    Schulz, M.S.; Vivit, D.; Schulz, C.; Fitzpatrick, J.; White, A.

    2010-01-01

    The distribution, chemistry, and morphology of Fe nodules were studied in a marine terrace soil chronosequence northwest of Santa Cruz, California. The Fe nodules are found at depths <1 m on all terraces. The nodules consisted of soil mineral grains cemented by Fe oxides. The nodules varied in size from 0.5 to 25 mm in diameter. Nodules did not occur in the underlying regolith. The Fe-oxide mineralogy of the nodules was typically goethite; however, a subset of nodules consisted of maghemite. There was a slight transformation to hematite with time. The abundance of soil Fe nodules increased with terrace age on the five terraces studied (aged 65,000-226,000 yr). Scanning electron microscopy (SEM) revealed Fe-oxide-containing fungal hyphae throughout the nodules, including organic structures incorporating fine-grained Fe oxides. The fine-grained nature of the Fe oxides was substantiated by M??ssbauer spectroscopy. Our microscopic observations led to the hypothesis that the nodules in the Santa Cruz terrace soils are precipitated by fungi, perhaps as a strategy to sequester primary mineral grains for nutrient extraction. The fungal structures are fixed by the seasonal wetting and dry cycles and rounded through bioturbation. The organic structures are compacted by the degradation of fungal C with time. ?? Soil Science Society of America. All rights reserved.

  12. Configuration of Miocene Basins Along the Santa Cruz-Catalina Ridge, California Continental Borderland

    NASA Astrophysics Data System (ADS)

    Stoller, A. R.; Legg, M.; Malone, D. H.

    2015-12-01

    Miocene basins associated with the oblique rifting of the Inner Continental Borderland offshore Southern California are preserved along the flanks of the transpressional Santa Cruz-Catalina Ridge. Using 184 lines of two-dimensional seismic data including high resolution records from Oregon State University and deep penetration data from Western Geco archived in USGS/NAMSS, we were able to map the configuration of the Miocene basin along the flanks of the northern core complex on the Santa Cruz-Catalina Ridge. There are distinct early and middle Miocene basins along the flanks of the ridge, which we are using to try to define the initial configuration of the Inner Borderland Rift. Along the hinge, between the uplifted ridge and the sub-horizontal basement in the Santa Monica Basin, lies the thickest part of the sequence. Pliocene to Recent sediments lap on to the tilted and uplifted Miocene basin sequences and constrain timing of uplift when transpression commenced. Segmentation and other distinctive character of the basin along the ridge flank may be correlated with similar features in the Miocene basin on the conjugate margin of the rift. Our working model for oblique rifting in the Borderland resembles of the Gulf of California, where right-stepping echelon transform faults link left-stepping extensional basins. The objective of our project is to reconstruct the configuration of the middle Miocene rift and to further our quest to understand the rifting process and tectonic evolution of the Pacific-North American plate boundary.

  13. Genetic Status and Timing of a Weevil Introduction to Santa Cruz Island, Galápagos

    PubMed Central

    2014-01-01

    Successful invasive species can overcome or circumvent the potential genetic loss caused by an introduction bottleneck through a rapid population expansion and admixture from multiple introductions. We explore the genetic makeup and the timing of a species introduction to Santa Cruz Island in the Galápagos archipelago. We investigate the presence of processes that can maintain genetic diversity in populations of the broad-nosed weevil Galapaganus howdenae howdenae. Analyses of combined genotypes for 8 microsatellite loci showed evidence of past population size reductions through moment and likelihood-based estimators. No evidence of admixture through multiple introductions was found, but substantial current population sizes (N0 298, 95% credible limits 50–2300), genetic diversity comparable with long-established endemics (Mean number of alleles = 3.875), and lack of genetic structure across the introduced range (F ST = 0.01359) could suggest that foundations are in place for populations to rapidly recover any loss of genetic variability. The time estimates for the introduction into Santa Cruz support an accidental transfer during the colonization period (1832–1959) predating the spurt in human population growth. Our evaluation of the genetic status of G. h. howdenae suggests potential for population growth in addition to our field observations of a concurrent expansion in range and feeding preferences towards protected areas and endemic host plants. PMID:24399746

  14. Methanotrophy under Versatile Conditions in the Water Column of the Ferruginous Meromictic Lake La Cruz (Spain)

    PubMed Central

    Oswald, Kirsten; Jegge, Corinne; Tischer, Jana; Berg, Jasmine; Brand, Andreas; Miracle, María R.; Soria, Xavier; Vicente, Eduardo; Lehmann, Moritz F.; Zopfi, Jakob; Schubert, Carsten J.

    2016-01-01

    Lakes represent a considerable natural source of methane to the atmosphere compared to their small global surface area. Methanotrophs in sediments and in the water column largely control methane fluxes from these systems, yet the diversity, electron accepting capacity, and nutrient requirements of these microorganisms have only been partially identified. Here, we investigated the role of electron acceptors alternative to oxygen and sulfate in microbial methane oxidation at the oxycline and in anoxic waters of the ferruginous meromictic Lake La Cruz, Spain. Active methane turnover in a zone extending well below the oxycline was evidenced by stable carbon isotope-based rate measurements. We observed a strong methane oxidation potential throughout the anoxic water column, which did not vary substantially from that at the oxic/anoxic interface. Both in the redox-transition and anoxic zones, only aerobic methane-oxidizing bacteria (MOB) were detected by fluorescence in situ hybridization and sequencing techniques, suggesting a close coupling of cryptic photosynthetic oxygen production and aerobic methane turnover. Additions of nitrate, nitrite and to a lesser degree iron and manganese oxides also stimulated bacterial methane consumption. We could not confirm a direct link between the reduction of these compounds and methane oxidation and we cannot exclude the contribution of unknown anaerobic methanotrophs. Nevertheless, our findings from Lake La Cruz support recent laboratory evidence that aerobic methanotrophs may be able to utilize alternative terminal electron acceptors under oxygen limitation. PMID:27891115

  15. The Solomon Islands tsunami of 6 February 2013 field survey in the Santa Cruz Islands

    NASA Astrophysics Data System (ADS)

    Fritz, H. M.; Papantoniou, A.; Biukoto, L.; Albert, G.

    2013-12-01

    On February 6, 2013 at 01:12:27 UTC (local time: UTC+11), a magnitude Mw 8.0 earthquake occurred 70 km to the west of Ndendo Island (Santa Cruz Island) in the Solomon Islands. The under-thrusting earthquake near a 90° bend, where the Australian plate subducts beneath the Pacific plate generated a locally focused tsunami in the Coral Sea and the South Pacific Ocean. The tsunami claimed the lives of 10 people and injured 15, destroyed 588 houses and partially damaged 478 houses, affecting 4,509 people in 1,066 households corresponding to an estimated 37% of the population of Santa Cruz Island. A multi-disciplinary international tsunami survey team (ITST) was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment and coral boulder depositions, land level changes, damage patterns at various scales, performance of the man-made infrastructure and impact on the natural environment. The 19 to 23 February 2013 ITST covered 30 locations on 4 Islands: Ndendo (Santa Cruz), Tomotu Noi (Lord Howe), Nea Tomotu (Trevanion, Malo) and Tinakula. The reconnaissance completely circling Ndendo and Tinakula logged 240 km by small boat and additionally covered 20 km of Ndendo's hard hit western coastline by vehicle. The collected survey data includes more than 80 tsunami runup and flow depth measurements. The tsunami impact peaked at Manoputi on Ndendo's densely populated west coast with maximum tsunami height exceeding 11 m and local flow depths above ground exceeding 7 m. A fast tide-like positive amplitude of 1 m was recorded at Lata wharf inside Graciosa Bay on Ndendo Island and misleadingly reported in the media as representative tsunami height. The stark contrast between the field observations on exposed coastlines and the Lata tide gauge recording highlights the importance of rapid tsunami reconnaissance surveys. Inundation distance and damage more than 500 m inland were recorded at Lata airport on Ndendo Island. Landslides were

  16. 78 FR 35951 - Proposed Low-Effect Habitat Conservation Plan for the City of Santa Cruz Graham Hill Water...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ... Graham Hill Water Treatment Plant, Santa Cruz County, California AGENCY: Fish and Wildlife Service... existing Graham Hill Water Treatment Plant, construction of new facilities, which have the potential for... system, the applicant operates the Graham Hill Water Treatment Plant. The Graham Hill Water...

  17. High-resolution topographic, bathymetric, and oceanographic data for the Pleasure Point Area, Santa Cruz County, California: 2005-2007

    USGS Publications Warehouse

    Storlazzi, Curt D.; Barnard, Patrick L.; Collins, Brian D.; Finlayson, David P.; Golden, Nadine E.; Hatcher, Gerry A.; Kayen, Robert E.; Ruggiero, Peter

    2007-01-01

    The County of Santa Cruz Department of Public Works and the County of Santa Cruz Redevelopment Agency requested the U.S. Geological Survey (USGS) Western Coastal and Marine Geology Team (WCMG) to provide baseline geologic and oceanographic information on the coast and inner shelf at Pleasure Point, Santa Cruz County, California. The rationale for this proposed work is a need to better understand the environmental consequences of a proposed bluff stabilization project on the beach, the nearshore and the surf at Pleasure Point, Santa Cruz County, California. To meet these information needs, the USGS-WCMG Team collected baseline scientific information on the morphology and waves at Pleasure Point. This study provided high-resolution topography of the coastal bluffs and bathymetry of the inner shelf off East Cliff Drive between 32nd Avenue and 41st Avenue. The spatial and temporal variation in waves and their breaking patterns at the study site were documented. Although this project did not actively investigate the impacts of the proposed bluff stabilization project, these data provide the baseline information required for future studies directed toward predicting the impacts of stabilization on the sea cliffs, beach and nearshore sediment profiles, natural rock reef structures, and offshore habitats and resources. They also provide a basis for calculating potential changes to wave transformations into the shore at Pleasure Point.

  18. List of the type-specimens of Reduviidae (Hemiptera: Heteroptera) in the Triatomines Collection of the Oswaldo Cruz Institute, Brazil.

    PubMed

    Rodrigues, Juliana Mourão Dos Santos; Moreira, Felipe Ferraz Figueiredo; Cordeiro, Isabelle Da Rocha Silva; De Almeida, Magaly Dolsan; Jurberg, José

    2015-03-19

    The Triatomines Collection of the Oswaldo Cruz Institute (CTIOC) holds 90 holotypes, seven syntypes, and 619 paratypes of the family Reduviidae, distributed in 44 genera and nine subfamilies: Chryxinae, Emesinae, Hammacerinae, Harpactorinae, Peiratinae, Reduviinae, Stenopodainae, Triatominae, and Vesciinae. A detailed list containing nomenclatural, taxonomic, and locality information about all these types is herein presented for the first time.

  19. Map showing locations of damaging landslides in Santa Cruz County, California, resulting from 1997-98 El Nino rainstorms

    USGS Publications Warehouse

    Baum, Rex L.; Schuster, Robert L.; Godt, Jonathan W.

    1999-01-01

    Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $14.5 million in damages were assessed in Santa Cruz County.

  20. Complex palaeosol ichnofabrics from Late Jurassic-Early Cretaceous volcaniclastic successions of Central Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Bedatou, Emilio; Melchor, Ricardo N.; Genise, Jorge F.

    2009-06-01

    Late Jurassic-Early Cretaceous volcaniclastic continental deposits from central Patagonia, Argentina were analyzed for an integral characterization of palaeosol ichnofabrics. These units contain complex continental ichnofabrics that were also recorded in other late Jurassic-late Miocene extended volcaniclastic successions from Patagonia. According to a recently proposed method, ichnofabric, pedofabric and original bedding of selected intervals were measured separately in order to determinate the degree in which the deposits are affected by soil features besides the ichnofabrics. Four recurrent ichnofabrics were recognized in studied palaeosols: the Loloichnus, large Taenidium- Beaconites, diffuse boxwork, and Dagnichnus ichnofabrics. The Loloichnus ichnofabric is characterized by sub-vertical Loloichnusbaqueroensis and subordinate, similarly arrenged large Taenidiumbarretti and Beaconitescoronus.L.baqueroensis is a crayfish dwelling structure while large T.barretti and B.coronus are assigned to locomotion of the same organisms. Root traces are additional components of this ichnofabric. The large Taenidium- Beaconites ichnofabric is formed by large, irregular and curved T.barretti and B.coronus and by L.baqueroensis in low proportion. This ichnofabric is also assigned to crayfish activity. The diffuse boxwork ichnofabric is characterized by a pervasive and intricate three-dimensional boxwork of burrows; occasionally joined to subspherical chambers (possible Castrichnus). The diffuse boxwork is interpreted as an earthworm burrow system and the associated chambers are probably for aestivation. Rare and scattered discrete trace fossils in this ichnofabric include L.baqueroensis, T.barretti and B.coronus. The Dagnichnus ichnofabric is formed by Dagnichnustitoi, root traces and, subordinately, Loloichnusbaqueroensis, Cellicalichnusmeniscatus and tangled groups of meniscate burrows. D.titoi and C.meniscatus has been interpreted as crayfish breeding structures and the

  1. Assessment of benthic changes during 20 years of monitoring the Mexican Salina Cruz Bay.

    PubMed

    González-Macías, C; Schifter, I; Lluch-Cota, D B; Méndez-Rodríguez, L; Hernández-Vázquez, S

    2009-02-01

    In this work a non-parametric multivariate analysis was used to assess the impact of metals and organic compounds in the macro infaunal component of the mollusks benthic community using surface sediment data from several monitoring programs collected over 20 years in Salina Cruz Bay, Mexico. The data for benthic mollusks community characteristics (richness, abundance and diversity) were linked to multivariate environmental patterns, using the Alternating Conditional Expectations method to correlate the biological measurements of the mollusk community with the physicochemical properties of water and sediments. Mollusks community variation is related to environmental characteristics as well as lead content. Surface deposit feeders are increasing their relative density, while subsurface deposit feeders are decreasing with respect to time, these last are expected to be more related with sediment and more affected then by its quality. However gastropods with predatory carnivore as well as chemosymbiotic deposit feeder bivalves have maintained their relative densities along time.

  2. Blaming Machismo: How the Social Imaginary is Failing Men with HIV in Santa Cruz, Bolivia.

    PubMed

    Heckert, Carina

    2017-01-01

    Drawing from an ethnography of HIV care in Santa Cruz, Bolivia, in this article I explore how the social imaginary surrounding gender relations shapes men's experiences of seeking care for and living with HIV. Popular understandings of gender relations, which draw heavily on the machismo concept, intersect with a global health master narrative that frames women as victims in the AIDS epidemic in a way that generates a strong sentiment of blaming machismo within local HIV/AIDS-related services. Statements such as, "it's because of machismo" are used to explain away epidemiological trends. Participant observation in the context of HIV care, coupled with illness narrative interviews, illuminate how blaming machismo shapes men's experiences of care and the ways that they feel excluded from various forms of support. Thus, the illness experiences of men with HIV problematize the machismo concept and how it is drawn upon in the context of care.

  3. Bacterial community profiles before, during, and after Pseudo-nitzschia bloom events in Santa Cruz, CA.

    NASA Astrophysics Data System (ADS)

    Mehic, S.; Sison-Mangus, M. P.; Jiang, S.; Kudela, R. M.

    2014-12-01

    Pseudo-nitzschia blooms are known to occur in coastal environments, sometimes leading to the production of the neurotoxin domoic acid. Various environmental factors (nutrients, temperature, pH, UV radiation etc.) have been implicated in the promotion and demise of these blooms but it is currently unknown if bacteria also plays a role in this ecological phenomenon. Studies suggest that bacteria have a profound effect on Pseudo-nitzschia physiology and toxin production, which influences its dominance in coastal environment. Here, we investigate the microbial assemblages before, during and after toxic and nontoxic Pseudo-nitzschia blooms to determine the patterns of bacterial succession in these events. Bacterial community profiles were determined weekly at the Santa Cruz Wharf using next generation sequencing and analyzed together with domoic acid levels, nutrients, temperature and phytoplankton structure. Bacterial structures and environmental trends will be correlated with the bloom events and will be subsequently discussed.

  4. Lamniform Shark Teeth from the Late Cretaceous of Southernmost South America (Santa Cruz Province, Argentina)

    PubMed Central

    Schroeter, Elena R.; Egerton, Victoria M.; Ibiricu, Lucio M.; Lacovara, Kenneth J.

    2014-01-01

    Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphological features with the genus Archaeolamna, including a developed neck that maintains a relatively consistent width along the base of the crown, the small sample size and incomplete nature of these specimens precludes definitive taxonomic assignment. Regardless, the discovery of selachian teeth unique from those previously described for the region broadens the known diversity of Late Cretaceous South American sharks. Additionally, the discovery of the teeth in fluvial sandstone may indicate a euryhaline paleobiology in the lamniform taxon or taxa represented by this tooth assemblage. PMID:25141301

  5. Insights from analyzing and modelling cascading multi-lake outburst flood events in the Santa Cruz Valley (Cordillera Blanca, Perú)

    NASA Astrophysics Data System (ADS)

    Emmer, Adam; Mergili, Martin; Juřicová, Anna; Cochachin, Alejo; Huggel, Christian

    2016-04-01

    Since the end of Little Ice Age, the Cordillera Blanca of Perú has experienced tens of lake outburst floods (LOFs), resulting in the loss of thousands of lives and significant material damages. Most commonly involving glacial lakes, such events are often directly or indirectly related to glacier retreat. Here we analyze an event on 8th February 2012 involving four lakes and affecting two valleys (Santa Cruz and Artizón) in the northern part of the Cordillera Blanca. Using the combination of field data, satellite images, digital elevation model (DEM) and GIS-based modelling approaches, the main objectives are: (i) to better understand complex multi-lake outburst flood and related foregoing and induced geomorphological processes; and (ii) to evaluate and discuss the suitability, potentials and limitations of the r.avaflow model for modelling such complex process chains. Analyzing field geomorphological evidence and remotely-sensed images, we reconstruct the event as follows: a landslide from the recently deglaciated left lateral moraine of Lake Artizón Alto (4 639 m a.s.l.), characterized by steep slopes and a height of more than 200 m produced a displacement wave which overtopped the bedrock dam of the lake. The resulting flood wave breached the dam of the downstream moraine-/landslide-dammed Lake Artizón Bajo (4 477 m a.s.l.), decreasing the lake level by 10 m and releasing 3 x 105 m3 of water. Significant amounts of material were eroded from the steeper parts of the Artizón Valley (mean slope >15°) and deposited further downstream in the flatter part of the Santa Cruz Valley (mean slope <2°; confluence of the two valleys at 3 985 m a.s.l.). The flood affected two debris cone-dammed lakes (Jatuncocha and Ichiccocha) in the Santa Cruz Valley. Some minor damages to the dam of Lake Jatuncocha were documented. Geomprohological evidence of the event was observed more than 20 km downstream from Lake Artizón Alto. The described multi-LOF event was employed as a

  6. Evaluation of toxicity of polluted marine sediments from Bahia Salina Cruz, Mexico.

    PubMed

    Gonzalez-Lozano, Maria Cristina; Mendez-Rodriguez, Lia C; Maeda-Martinez, Alejandro M; Murugan, Gopal; Vazquez-Botello, Alfonso

    2010-01-01

    Bahia Salina Cruz, Oaxaca, Mexico is a major center of oil and refined product distribution on the Mexican Pacific coast. From the start of oil industry operations in 1979, negative effects from discharges of treated effluents in the bay have been a constant concern for local communities. We analyzed 28 surface sediment samples obtained in June, 2002 to evaluate the level of toxicity in the littoral zone, port-harbor, and La Ventosa estuary in Bahia Salina Cruz. The extractable organic matter concentration was high (1,213 to 7,505 micro g g(-1)) in 5 of 7 stations from the port and harbor, whereas it was low in 12 of 16 stations in the littoral zone (36 to 98 micro g g(-1)). The total aromatic hydrocarbon concentration was highest (57 to 142 micro g g(-1)) in the port and harbor compared to the La Ventosa estuary and the littoral zone. Among the heavy metals analyzed, cadmium exceeded the effects range-low values associated with adverse biological effects. The geo-accumulation index of sediments was moderate to strong contamination at 5 stations in the nonlittoral and 6 stations in the littoral zone. The enrichment of lead, zinc, and cadmium at 5 stations from the littoral, port, and harbor suggest that these metals are of anthropogenic origin. Bioassay tests of elutriates of sediments on nauplii of Artemia franciscana and Artemia sp. showed that the port and harbor were more toxic than the La Ventosa estuary and the coastal zone. The Microtox test (Vibrio fischeri) did not show a similar response with the solid phase of the sediments. The results of this study indicate that the high levels of organic content and metals in the sediments of port-harbor and the La Ventosa estuary are mainly caused by anthropogenic activities.

  7. Geochemistry of oil from Santa Cruz basin, Bolivia: case study of migration-fractionation

    SciTech Connect

    Illich, H.A.; Haney, F.R.; Mendoza, M.

    1981-11-01

    Geochemical studies provide important data relevant to the origin of the oils in the Santa Cruz basin, Bolivia. Production from this basin occurs from rocks of Devonian, Carboniferous, Cretaceous, and Tertiary ages. The productive structures are usually undisturbed by major faulting. The Devonian sediments are composed of sandstones and dark marine shales. The post-Devonian rocks are generally oxidized and probably nonmarine. The Tertiary and Cretaceous reservoirs usually contain the highest API/sup 0/ gravity oils. Comparison of geochemical data (N/sub 5/-N/sub 10/ molecular weight range) shows that the oils are very similar; however, systematic compositional trends occur as a function of API/sup 0/ gravity. These trends are interpreted from gross structural group data. Isoparaffins and cycloparaffins increase in relative abundance, while normal paraffins and aromatics decrease with increasing API/sup 0/ gravity. A model is proposed that rationalizes these compositional trends by a mechanism of accommodation in water. The model requires enrichment of hydrocarbons of intermediate solubility, partial exclusion of hydrocarbons of low solubility, and retention in solution of the more soluble hydrocarbons. Processes such as thermal fractionation and biodegradation fail to account satisfactorily for the observed compositional trends. The compositional interrelationships of the oils coupled with the geologic framework suggest that these oils have a common source, most probably the Devonian. Differences between the oils are attributed to fractionation occurring during migration. Exploration risk for areas such as the Santa Cruz basin can be substantially reduced by use of the knowledge derived from petroleum geochemistry.

  8. Cretaceous Small Scavengers: Feeding Traces in Tetrapod Bones from Patagonia, Argentina

    PubMed Central

    de Valais, Silvina; Apesteguía, Sebastián; Garrido, Alberto C.

    2012-01-01

    Ecological relationships among fossil vertebrate groups are interpreted based on evidence of modification features and paleopathologies on fossil bones. Here we describe an ichnological assemblage composed of trace fossils on reptile bones, mainly sphenodontids, crocodyliforms and maniraptoran theropods. They all come from La Buitrera, an early Late Cretaceous locality in the Candeleros Formation of northwestern Patagonia, Argentina. This locality is significant because of the abundance of small to medium-sized vertebrates. The abundant ichnological record includes traces on bones, most of them attributable to tetrapods. These latter traces include tooth marks that provde evidence of feeding activities made during the sub-aerial exposure of tetrapod carcasses. Other traces are attributable to arthropods or roots. The totality of evidence provides an uncommon insight into paleoecological aspects of a Late Cretaceous southern ecosystem. PMID:22253800

  9. Cretaceous small scavengers: feeding traces in tetrapod bones from Patagonia, Argentina.

    PubMed

    de Valais, Silvina; Apesteguía, Sebastián; Garrido, Alberto C

    2012-01-01

    Ecological relationships among fossil vertebrate groups are interpreted based on evidence of modification features and paleopathologies on fossil bones. Here we describe an ichnological assemblage composed of trace fossils on reptile bones, mainly sphenodontids, crocodyliforms and maniraptoran theropods. They all come from La Buitrera, an early Late Cretaceous locality in the Candeleros Formation of northwestern Patagonia, Argentina. This locality is significant because of the abundance of small to medium-sized vertebrates. The abundant ichnological record includes traces on bones, most of them attributable to tetrapods. These latter traces include tooth marks that provde evidence of feeding activities made during the sub-aerial exposure of tetrapod carcasses. Other traces are attributable to arthropods or roots. The totality of evidence provides an uncommon insight into paleoecological aspects of a Late Cretaceous southern ecosystem.

  10. Alien Invasions and the Game of Hide and Seek in Patagonia

    PubMed Central

    Lindegren, Martin; Vigliano, Pablo; Nilsson, P. Anders

    2012-01-01

    The introduction, establishment and spread of alien species is a major threat to biodiversity and the provision of ecosystem services for human wellbeing. In order to reduce further loss of biodiversity and maintain productive and sustainable ecosystems, understanding the ecological mechanisms underlying species invasions and avoiding potentially harmful effects on native communities is urgently needed, but largely lacking. We here demonstrate, by means of hydroacoustics and advanced spatial modelling, how native fish species as a result of previous exposure to native predators may successfully respond to invasive novel predators through a complicated game of hide and seek, minimizing spatio-temporal overlap with predators, and potentially facilitating coexistence between native prey species (Galaxiids) and introduced novel predators (Salmonids) in a deep Andean lake, Patagonia. PMID:23071496

  11. Vegetation dynamics and disturbance regimes in northern Patagonia, Argentina: The roles of humans and climate variation

    SciTech Connect

    Veblen, T.T.; Kitzberger, T.; Villalba, R. )

    1993-06-01

    In northern Patagonia (c. 40[degrees] S.), we examined the roles of human activities and climate variation in the modification of disturbance regimes and vegetation dynamics along a gradient from Andean rainforest to the Patagonian steppe. Human-set fires and introduced herbivores (livestock and deer) have had dramatic impacts on the vegetation, the nature of which varies according to position along the macro-scale gradient. For example, European settlement resulted in increased fire frequency in the wet forest district whereas near the steppe fire frequency declined. Climate variability also has had important influences through the alteration of fire regimes and by directly influencing tree mortality and regeneration. The nature and consequences of the influences of climate variation are also distinct for different portions of the macro-scale environmental gradient.

  12. New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods

    NASA Astrophysics Data System (ADS)

    Canale, Juan I.; Scanferla, Carlos A.; Agnolin, Federico L.; Novas, Fernando E.

    2009-03-01

    A nearly complete skeleton of the new abelisaurid Skorpiovenator bustingorryi is reported here. The holotype was found in Late Cenomanian-Early Turonian outcrops of NW Patagonia, Argentina. This new taxon is deeply nested within a new clade of South American abelisaurids, named Brachyrostra. Within brachyrostrans, the skull shortening and hyperossification of the skull roof appear to be correlated with a progressive enclosure of the orbit, a set of features possibly related to shock-absorbing capabilities. Moreover, the development of horn-like structures and differential cranial thickening appear to be convergently acquired within Abelisauridae. Based on the similarities between Skorpiovenator and carcharodontosaurid tooth morphology, we suggest that isolated teeth originally referred as post-Cenomanian Carcharodontosauridae most probably belong to abelisaurids.

  13. Bonitasaura salgadoi gen. et sp. nov.: a beaked sauropod from the Late Cretaceous of Patagonia

    NASA Astrophysics Data System (ADS)

    Apesteguía, Sebastián

    2004-10-01

    Ornithischian and theropod dinosaurs were morphologically diverse during the Cretaceous. In contrast, sauropods were relatively more conservative. The anatomy of Bonitasaura salgadoi, a new 9-m titanosaurian sauropod from Upper Cretaceous beds of Patagonia, suggests that sauropod anatomical diversity would have included unexpected items. Its unusual, rectangular lower jaw possesses narrow, anteriorly restricted teeth and shows evidence of a sharp keratinous sheath over the non-dentigerous region that probably worked to guillotine plant material. This discovery definitely demonstrates that titanosaurs acquired a mandibular configuration similar to that of some basal diplodocoids, as had already been suggested by the lower jaw of the controversial genus Antarctosaurus. This oral configuration, plus the beak-like structure and the skull shape, resemble some traits more commonly seen in Laurasian ornithischians, mostly unexpressed in southern continents. A high sauropod morphological diversity seems to be in agreement with the poorly represented ornithischian clades of the southern hemisphere.

  14. New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods.

    PubMed

    Canale, Juan I; Scanferla, Carlos A; Agnolin, Federico L; Novas, Fernando E

    2009-03-01

    A nearly complete skeleton of the new abelisaurid Skorpiovenator bustingorryi is reported here. The holotype was found in Late Cenomanian-Early Turonian outcrops of NW Patagonia, Argentina. This new taxon is deeply nested within a new clade of South American abelisaurids, named Brachyrostra. Within brachyrostrans, the skull shortening and hyperossification of the skull roof appear to be correlated with a progressive enclosure of the orbit, a set of features possibly related to shock-absorbing capabilities. Moreover, the development of horn-like structures and differential cranial thickening appear to be convergently acquired within Abelisauridae. Based on the similarities between Skorpiovenator and carcharodontosaurid tooth morphology, we suggest that isolated teeth originally referred as post-Cenomanian Carcharodontosauridae most probably belong to abelisaurids.

  15. A gigantic, exceptionally complete titanosaurian sauropod dinosaur from southern Patagonia, Argentina.

    PubMed

    Lacovara, Kenneth J; Lamanna, Matthew C; Ibiricu, Lucio M; Poole, Jason C; Schroeter, Elena R; Ullmann, Paul V; Voegele, Kristyn K; Boles, Zachary M; Carter, Aja M; Fowler, Emma K; Egerton, Victoria M; Moyer, Alison E; Coughenour, Christopher L; Schein, Jason P; Harris, Jerald D; Martínez, Rubén D; Novas, Fernando E

    2014-09-04

    Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death.

  16. Cystobasidiomycetes yeasts from Patagonia (Argentina): description of Rhodotorula meli sp. nov. from glacial meltwater.

    PubMed

    Libkind, Diego; Sampaio, José Paulo; van Broock, Maria

    2010-09-01

    A basidiomycetous yeast, strain CRUB 1032(T), which formed salmon-pink colonies, was isolated from glacial meltwater in Patagonia, Argentina. Morphological, physiological and biochemical characterization indicated that this strain belonged to the genus Rhodotorula. Molecular taxonomic analysis based on the 26S rDNA D1/D2 domain and internal transcribed spacer region sequences showed that strain CRUB 1032(T) represents an undescribed yeast species, for which the name Rhodotorula meli sp. nov. is proposed (type strain is CRUB 1032(T)=CBS 10797(T)=JCM 15319(T)). Phylogenetic analysis showed that Rhodotorula lamellibrachii was the closest known species, which, together with R. meli, formed a separate cluster related to the Sakaguchia clade within the Cystobasidiomycetes. Additional Patagonian yeast isolates of the class Cystobasidiomycetes are also investigated in the present work.

  17. A new late Cenozoic species of Abertella (Echinoidea: Clypeasteroida) from Patagonia.

    PubMed

    Kroh, Andreas; Mooi, Rich; Del Río, Claudia; Neumann, Christian

    2013-01-22

    A new species of abertellid sand dollar, Abertella miskellyi n. sp., is described from the Miocene Camarones Formation of Patagonia, southern Argentina. The new taxon corroborates the existence of the genus in South America, given that Abertella is most common in the southeastern USA and the eastern coast of Central America. It is characterized by a unique basicoronal circle, in which the interambulacral basicoronal plates are very heterogeneous in size (small in interambulacrum 5, largest in interambulacra 2 and 3). Additionally, it features disjunct oral interambulacra involving two ambulacral plates in some of the interambulacra rather than one, thus being the most disjunct of all known species of Abertella. A key to the species of the genus is provided.

  18. Linked canopy, climate, and faunal change in the Cenozoic of Patagonia.

    PubMed

    Dunn, Regan E; Strömberg, Caroline A E; Madden, Richard H; Kohn, Matthew J; Carlini, Alfredo A

    2015-01-16

    Vegetation structure is a key determinant of ecosystems and ecosystem function, but paleoecological techniques to quantify it are lacking. We present a method for reconstructing leaf area index (LAI) based on light-dependent morphology of leaf epidermal cells and phytoliths derived from them. Using this proxy, we reconstruct LAI for the Cenozoic (49 million to 11 million years ago) of middle-latitude Patagonia. Our record shows that dense forests opened up by the late Eocene; open forests and shrubland habitats then fluctuated, with a brief middle-Miocene regreening period. Furthermore, endemic herbivorous mammals show accelerated tooth crown height evolution during open, yet relatively grass-free, shrubland habitat intervals. Our Patagonian LAI record provides a high-resolution, sensitive tool with which to dissect terrestrial ecosystem response to changing Southern Ocean conditions during the Cenozoic.

  19. Notocotylus biomphalariae n. sp. (Digenea: Notocotylidae)from Biomphalaria peregrina (Gastropoda: Pulmonata) in Patagonia, Argentina.

    PubMed

    Flores, Verónica; Brugni, Norma

    2005-07-01

    A new species of Notocotylus was found parasiting a freshwater pulmonate snail, Biomphalaria peregrina. Naturally infected snails were collected from two temporary ponds in the Nahuel Huapí National Park in Patagonia. The characteristics of the larval stages are presented. Experimental adults were recovered from the intestinal caeca of ducks and chicks. Adults of Notocotylus biomphalariae n. sp. exhibit an aspinose tegument, two lateral rows of 11 ventral glands and a median row of four, a uterus with 12-16 coils of which 2-4 are previtelline, a metraterm equivalent in size to 65-68% of the cirrus-sac length, a previtelline field which extends to the middle of the body, a lobed testis and a genital pore closely posterior to the intestinal bifurcation. The rediae have one to three cercariae. The cercariae, when shed, are trioculate and have a long tail; they encyst in the environment and become infective 12 days after encystment.

  20. Marine pollution effects on the southern surf crab Ovalipes trimaculatus (Crustacea: Brachyura: Polybiidae) in Patagonia Argentina.

    PubMed

    Lezcano, Aníbal Hernán; Rojas Quiroga, María Laura; Liberoff, Ana Laura; Van der Molen, Silvina

    2015-02-28

    We compared the carapace shape and thickness as well as the energy density of Ovalipes trimaculatus inhabiting areas comprising a gradient of marine pollution: high, moderate and undetected, in the Nuevo gulf (Patagonia Argentina). The carapace shape was evaluated by means of individual asymmetry scores (=fluctuating asymmetry) whereas the carapace thickness was assessed by measuring the carapace dry weight. The energy density was analyzed through its negative relationship with water content in muscle tissue. The individual asymmetry scores as well as the percentage of water content in muscle tissue were proportional to the marine pollution gradient, whereas the carapaces thickness did not differ among sampling sites. Our results are consistent with previous findings and demonstrate the direct effect of marine pollution on other taxa different from gastropods, cephalopods and polyplacophora and add to long-standing concerns about detrimental effects caused by marine pollution on the benthic community of the Nuevo gulf.

  1. Lack of founding Amerindian mitochondrial DNA lineages in extinct aborigines from Tierra del Fuego-Patagonia.

    PubMed

    Lalueza, C; Pérez-Pérez, A; Prats, E; Cornudella, L; Turbón, D

    1997-01-01

    Ancient DNA from bones and teeth of 60 individuals from four extinct human populations from Tierra del Fuego-Patagonia (Selknam, Yamana, Kaweskar and Aonikenk) has been extracted and the mitochondrial DNA (mtDNA) amplified by using the polymerase chain reaction. High-resolution analysis of endonuclease restriction site variation in the mtDNA and sequencing of its hypervariable non-coding control region, revealed complete absence of two of the four primary mitochondrial haplotype groups present in contemporary Amerinds, namely A and B. In contrast, haplogroups C and D were found in all but one sample with frequencies of approximately 38% and 60%. These results, together with the decreasing incidence of group A in more southerly latitudes in the American continent and the absence of cluster B above 55 degrees North in America and Asia, argue that the first settlers entering America 21000-14000 years ago already lacked both mtDNA lineages.

  2. Lower Cretaceous anoxic conditions IN the Austral basin, south-western Gondwana, Patagonia Argentina

    NASA Astrophysics Data System (ADS)

    Richiano, Sebastián

    2014-10-01

    The reconstruction of palaeo-oxygenation levels in marine deposits from the Cretaceous has obtained a huge interest all around the world in recent years. This fascinating topic is here pointed out for the first time in the Austral Basin using the information provided by the black shales of the Río Mayer Formation, Patagonia, Argentina. The combination of sedimentology, ichnology and geochemistry (TOC, Ce anomaly and MnO content) allow the identification of three major intervals respecting the oxygen content. During the Berriasian and early Valanginian anoxic conditions prevail in the outer shelf. After that, between the late Valanginian and Hauterivian dysoxic palaeoenvironments were developed. Finally, a more oxygenated palaeoenvironment occurred since Aptian associated with a progradation of a proximal deltaic system. The identification of anoxic conditions is of much interest for the hydrocarbon research in this stratigraphical unit, which represents the most significant source rock of the Austral Basin.

  3. Contribution of the Patagonia Icefields of South America to sea level rise.

    PubMed

    Rignot, Eric; Rivera, Andrés; Casassa, Gino

    2003-10-17

    Digital elevation models of the Northern and Southern Patagonia Icefields of South America generated from the 2000 Shuttle Radar Topography Mission were compared with earlier cartography to estimate the volume change of the largest 63 glaciers. During the period 1968/1975-2000, these glaciers lost ice at a rate equivalent to a sea level rise of 0.042 +/- 0.002 millimeters per year. In the more recent years 1995-2000, average ice thinning rates have more than doubled to an equivalent sea level rise of 0.105 +/- 0.011 millimeters per year. The glaciers are thinning more quickly than can be explained by warmer air temperatures and decreased precipitation, and their contribution to sea level per unit area is larger than that of Alaska glaciers.

  4. Map Showing Seacliff Response to Climatic and Seismic Events, Seabright Beach, Santa Cruz County, California

    USGS Publications Warehouse

    Hapke, Cheryl J.; Richmond, Bruce M.; D'Iorio, Mimi M.

    2002-01-01

    Introduction The coastal cliffs along much of the central California coast are actively retreating. Large storms and periodic earthquakes are responsible for most of the documented sea cliff slope failures. Long-term average erosion rates calculated for this section of coast do not provide the spatial or temporal data resolution necessary to identify the processes responsible for retreat of the sea cliffs where episodic retreat threatens homes and community infrastructure. Research suggests that more erosion occurs along the California coast over a short time scale, during periods of severe storms or seismic activity, than occurs during decades of normal weather or seismic quiescence. This is the third map in a series of maps prepared to document the processes of short-term sea cliff retreat through the identification of slope failure styles, spatial variability of failures, and temporal variation in retreat amounts in an area that has been identified as an erosion hotspot. This map presents sea cliff failure and retreat data from the Seabright Beach section, California, which is located on the east side of Santa Cruz along the northern Monterey Bay coast. The data presented in this map series provide high-resolution spatial and temporal information on the location, amount, and processes of sea cliff retreat in Santa Cruz, California. These data show the response of the sea cliffs to both large magnitude earthquakes and severe climatic events such as El Ni?os; this information may prove useful in predicting the future response of the cliffs to events of similar magnitude. The map data can also be incorporated into Global Information System (GIS) for use by researchers and community planners. During this study we developed a method for investigating short-term processes of sea cliff evolution using rectified photographic stereo models. This method allows us to document the linear extent of cliff failures, the spatial and temporal relationship between failures, and

  5. Respiratory Function in Voluntary Participating Patagonia Sea Lions (Otaria flavescens) in Sternal Recumbency

    PubMed Central

    Fahlman, Andreas; Madigan, Johnny

    2016-01-01

    We measured esophageal pressures (n = 4), respiratory flow rates (n = 5), and expired O2 and CO2 (n = 4) in five adult Patagonia sea lions (Otaria flavescens, body mass range 94.3–286.0 kg) during voluntary breaths while laying down out of water. The data were used to estimate the dynamic specific lung compliance (sCL), the O2 consumption rate (V˙O2) and CO2 production rates (V˙CO2) during rest. Our results indicate that the resting tidal volume in Patagonia sea lions is approximately 47–73% of the estimated total lung capacity. The esophageal pressures indicated that expiration is passive during voluntary breaths. The average sCL of sea lions was 0.41 ± 0.11 cmH2O−1, which is similar to those measured in anesthetized sea lions and awake cetaceans, and significantly higher as compared to humans (0.08 cmH2O−1). The average estimated V˙O2 and V˙CO2 using breath-by-breath respirometry were 1.023 ± 0.327 L O2 min−1 (range: 0.695–1.514 L O2 min−1) and 0.777 ± 0.318 L CO2 min−1, (range: 0.510–1.235 L CO2 min−1), respectively, which is similar to previously published metabolic measurements from California and Steller sea lions using conventional flow-through respirometry. Our data provide end-tidal gas composition and offer novel data for respiratory physiology in pinnipeds, which may be important for clinical medicine and conservation efforts. PMID:27899896

  6. Respiratory Function in Voluntary Participating Patagonia Sea Lions (Otaria flavescens) in Sternal Recumbency.

    PubMed

    Fahlman, Andreas; Madigan, Johnny

    2016-01-01

    We measured esophageal pressures (n = 4), respiratory flow rates (n = 5), and expired O2 and CO2 (n = 4) in five adult Patagonia sea lions (Otaria flavescens, body mass range 94.3-286.0 kg) during voluntary breaths while laying down out of water. The data were used to estimate the dynamic specific lung compliance (sCL), the O2 consumption rate ([Formula: see text]O2) and CO2 production rates ([Formula: see text]CO2) during rest. Our results indicate that the resting tidal volume in Patagonia sea lions is approximately 47-73% of the estimated total lung capacity. The esophageal pressures indicated that expiration is passive during voluntary breaths. The average sCL of sea lions was 0.41 ± 0.11 cmH2O(-1), which is similar to those measured in anesthetized sea lions and awake cetaceans, and significantly higher as compared to humans (0.08 cmH2O(-1)). The average estimated [Formula: see text]O2 and [Formula: see text]CO2 using breath-by-breath respirometry were 1.023 ± 0.327 L O2 min(-1) (range: 0.695-1.514 L O2 min(-1)) and 0.777 ± 0.318 L CO2 min(-1), (range: 0.510-1.235 L CO2 min(-1)), respectively, which is similar to previously published metabolic measurements from California and Steller sea lions using conventional flow-through respirometry. Our data provide end-tidal gas composition and offer novel data for respiratory physiology in pinnipeds, which may be important for clinical medicine and conservation efforts.

  7. Cultural Transmission of Traditional Knowledge in two populations of North-western Patagonia

    PubMed Central

    Eyssartier, Cecilia; Ladio, Ana H; Lozada, Mariana

    2008-01-01

    Background In the present study we have investigated the cultural transmission of two types of traditional plant knowledge in two communities of North-western Patagonia, Argentina. In the Pilcaniyeu community, we studied the transmission of traditional knowledge related to horticultural practices in home-gardens, greenhouses and gardens; while in the community of Cuyin Manzano, we studied wild plant gathering customs. Methods Ethnobotanical fieldwork was conducted by means of semi-structured interviews, in which we investigated which plants are used, at what life history phase was learned, modes of transmission and who the principal transmitters were in childhood and adulthood. In both communities, each of this three aspects related to cultural transmission were categorized and the frequencies of each category were obtained. The total number of species recorded in each community was also calculated. Frequencies were analyzed with the Chi-square test of independence. Results and discussion In both communities, transmission of traditional plant knowledge begins at an early age, as a family custom, in which women play a predominant role. Wild plant use and horticultural knowledge continue to be learned during adulthood. This was particularly registered associated with horticultural learning, which receives greater influence from extension agents who are introducing new practices and technology. This outside influence, which implies novelty, could imply syncretism but also traditional knowledge loss. Conclusion Given the remarkable acculturation processes occurring at present in rural communities of Northwestern Patagonia, it might be of vital importance to document traditional knowledge of ancient practices. Moreover, it could be interesting to share our results with both populations in order to encourage participatory activities within the communities which could enhance traditional knowledge horizontal transmission, particularly among elder adults and youngsters

  8. Fire affects size and shape of Fabiana imbricata Shurblands in northwestern Patagonia

    NASA Astrophysics Data System (ADS)

    Oddi, Facundo; Ghermandi, Luciana

    2010-05-01

    Fire is a major environmental ecological agent acting in the landscape configuration and a factor that models vegetation in Mediterranean environments. Fire impacts differently in the landscape due to the intrinsic heterogeneity of the environments and the characteristics associated with each fire event. After fire, density of patches may be increased and the size of them may be reduced because fire generates areas of different successional stages. Landscape ecology seems to be the ideal theoretical approach to study the fire impact in fire prone environments. Landscape ecology has been greatly favoured by a significant progress in the last years of geographic information technologies (GIT) (remote sensing, GIS, GPS). The study area of this work is the San Ramon ranch (22,000 ha) located in Northwester Patagonia in the ecotone between the sub Antarctic forest in the West and the Patagonian steppe in the East. We studied sectors of the ranch with different fire recurrence in the last 40 years and we mapped Fabiana imbricata shrubland with GPS. This specie is a native shrub characteristic of Northwester Patagonia grasslands and its dynamic is not very known. Shrublands compete for the space with palatable grasses that are used for forage and livestock production, the main economic resource of the region. We analysed the mapped patches with GIS software, and we assessed landscape metrics to determine differences between sites with different fire recurrence. In the future we foresee the integrated use of satellite imagery with different resolution to add to GIS other important spatial variables (topography, hydrography, aspect, soil) to develop models that can explain landscape metrics, spatial configuration and the potential shrub invasion in the grassland.

  9. The tectonographic development of Patagonia and its relevance to hydrocarbon exploration

    SciTech Connect

    Light, M.P.R.; Urien, C.M.; Maslanyj, M.P.; Keeley, M.L.; Hoggs, S.L.

    1993-02-01

    Patagonia accreted successively from the southwest onto the southern margin of the Proterozoic Plata Craton and Brazilian Guapore Shield between the Late Proterozoic and Early Devonian. The thrust-like stacking of terranes onto the southern termination of the Pelotas Terrane is considered to have developed a pervasive northwest to north-trending fabric. During the Permo-Triassic the northwest to north-trending fabric of the Patagonian Plate was re-activated by dextral strike-slip movement causing extension. The deformation was caused by oblique subduction and accretion of the madre Dos Dios to Pichidangui Terranes along its western margin. To the northeast the more competent shield underwent compression (Ventania-Gond-wanide Folding) and extension occurred parallel to the axis of the embryo South Atlantic, where a shallow sea transgressed. Ridge on its western side, now preserved on the facing shelf margins of Argentina and Namibia. In the Late Triassic-Lower Jurassic, the Malvinas and Microplate was situated south of the Transkei (South Africa) and an intracratonic basin separated it from two sutures formed at the margin of the Argentine Shelf and along the axis of the West Malvinas Basin. Subduction/arc activity on the west flank of this intracratonic basin, in association with trench pull is believed to have initiated Late Triassic-Early Jurassic strike slip extension and volcanicity in Patagonia. This exploited the pervasive northwest and north-trending Paleozoic fabric. By the Mid-Jurassic the Malvinas Microplate had docked with the eastern margin of the Patagonian Shelf and was undergoing clockwise rotation between the Malvinas-Agulhas and Burwood Bank-Scotia Ridge dextral strike-slip systems. Rifting had now progressed southwestwards to the Pacific and north eastwards to the Colorado and Outeniqua Basins.

  10. Nutritional status and obesity in children and young adults with disabilities in Punta Arenas, Patagonia, Chile.

    PubMed

    Vélez, Juan C; Fitzpatrick, Annette L; Barbosa, Clara I; Díaz, Mauricio; Urzua, Miyochi; Andrade, Asterio H

    2008-12-01

    Childhood obesity is reaching epidemic proportions throughout the world; however, little is known on the nutritional status of children with disabilities. To address this issue, medical records of 748 children aged 18 years or younger receiving physical therapy during 2004-2005 at a privately sponsored free rehabilitation clinic in Punta Arenas, Patagonia, Chile were abstracted. Data included demographic, clinical, and anthropometric information recorded at the first visit. As a comparison, height and weight were also collected in 215 children attending local schools. Nutritional status was calculated as body mass index (above 6 years of age) or evaluated by growth curves (6 years of age or below) as undernourished, normal, overweight, obese, or morbidly obese. Logistic regression was used to determine risk factors for obesity in these children. Overall, a significant difference in nutritional status between disabled and non-disabled children was found (P<0.001). Children with disabilities had a higher prevalence of both below and above normal weight than non-disabled children. Risk factors for obesity included increasing age and living with a grandparent independent of other socioeconomic factors. Compared with normal children, risk of obesity was doubled for those with developmental delays [odds ratio (OR): 1.96; 95% confidence interval (CI): 1.16-3.34] and neurological disorders (OR: 2.58, 95% CI: 1.26-5.29), whereas individuals with cerebral palsy were less than half as likely to be obese than non-disabled children (OR: 0.46, 95% CI: 0.20-1.03). We conclude that overnutrition continues to be a problem for both disabled and non-disabled children in Patagonia. Programs to increase physical activity and improve nutrition are needed in this isolated part of the world.

  11. Luminescence dating of glacial advances at Lago Buenos Aires (∼46 °S), Patagonia

    NASA Astrophysics Data System (ADS)

    Smedley, R. K.; Glasser, N. F.; Duller, G. A. T.

    2016-02-01

    Understanding the timing of past glacial advances in Patagonia is of global climatic importance because of the insight this can provide into the influence on glacier behaviour of changes in temperature and precipitation related to the Southern Westerlies. In this paper we present new luminescence ages determined using single grains of K-feldspar from proglacial outwash sediments that were deposited by the Patagonian Ice Sheet around Lago Buenos Aires (∼46 °S), east of the contemporary Northern Patagonian Icefield. The new luminescence ages indicate that major outwash accumulations formed around ∼110 ± 20 ka to 140 ± 20 ka and that these correspond to the Moreno I and II moraine ridges, which were previously dated using cosmogenic isotope dating to 150 ± 30 ka. Luminescence dating at Lago Buenos Aires has also identified outwash sediments that were deposited during glacial advances ∼30.8 ± 5.7 ka and ∼34.0 ± 6.1 ka (MIS 3) that are not recorded in the moraine record. Younger outwash accumulations were then deposited between ∼14.7 ± 2.1 and 26.2 ± 1.6 ka which correspond to the Fenix I - V moraine ridges. The combined chronology suggests that glacial advances occurred ∼110 ± 20 ka to 150 ± 30 ka (MIS 6), ∼30.8 ± 5.7 ka to ∼34.0 ± 6.1 ka (MIS 3), and ∼14.7 ± 2.1 to 26.2 ± 1.6 ka (MIS 2) at Lago Buenos Aires. Overall luminescence dating using single grains of K-feldspar has excellent potential to contribute towards the ever-increasing geochronological dataset constraining the timings of glacial advances in Patagonia.

  12. Stable oxygen isotopes (delta18(O)) in Austrocedrus chilensis tree rings reflect climate variability in northwestern Patagonia, Argentina.

    PubMed

    Roig, F A; Siegwolf, R; Boninsegna, J A

    2006-11-01

    The stable oxygen isotope (delta (18)O) composition of Austrocedrus chilensis (D. Don) Endl. (Cupressaceae) tree rings potentially provide retrospective views of changes in environment and climate in the semi-arid lands of Patagonia. We report the development of the first annually resolved delta (18)O tree-ring chronology obtained from natural forests of the foothills of the northwestern Patagonian Andes. The isotope record spans between 1890 and 1994 AD. We explore the probable links between this record and the climate of the region. Air temperatures during summer conditions are significantly, but not strongly, inversely correlated with annual delta (18)O values from Austrocedrus tree rings. The strongest correlations are between the southern oscillation index (SOI) and the tree rings. The existence of millennial-age Austrocedrus trees in northern Patagonia provides interesting possibilities for examining these climate-related isotopic signals over most of the last 1,000 years.

  13. Detection of Salmonella enterica in Magellanic penguins (Spheniscus magellanicus) of Chilean Patagonia: evidences of inter-species transmission.

    PubMed

    Dougnac, C; Pardo, C; Meza, K; Arredondo, C; Blank, O; Abalos, P; Vidal, R; Fernandez, A; Fredes, F; Retamal, P

    2015-04-01

    Patagonia in southern South America is among the few world regions where direct human impact is still limited but progressively increasing, mainly represented by tourism, farming, fishing and mining activities. The sanitary condition of Patagonian wildlife is unknown, in spite of being critical for the assessment of anthropogenic effects there. The aim of this study was the characterization of Salmonella enterica strains isolated from wild colonies of Magellanic penguins (Spheniscus magellanicus) located in Magdalena Island and Otway Sound, in Chilean Patagonia. Eight isolates of Salmonella were found, belonging to Agona and Enteritidis serotypes, with an infection rate of 0·38%. Resistance to ampicillin, cefotaxime, ceftiofur and tetracycline antimicrobials were detected, and some of these strains showed genotypic similarity with Salmonella strains isolated from humans and gulls, suggesting inter-species transmission cycles and strengthening the role of penguins as sanitary sentinels in the Patagonian ecosystem.

  14. Invasive salmonids and lake order interact in the decline of puye grande Galaxias platei in western Patagonia lakes.

    PubMed

    Correa, Cristian; Hendry, Andrew P

    2012-04-01

    Salmonid fishes, native to the northern hemisphere, have become naturalized in many austral countries and appear linked to the decline of native fishes, particularly galaxiids. However, a lack of baseline information and the potential for confounding anthropogenic stressors have led to uncertainty regarding the association between salmonid invasions and galaxiid declines, especially in lakes, as these have been much less studied than streams. We surveyed 25 lakes in the Aysén region of Chilean Patagonia, including both uninvaded and salmonid-invaded lakes. Abundance indices (AI) of Galaxias platei and salmonids (Salmo trutta and Oncorhynchus mykiss) were calculated using capture-per-unit-effort data from gillnets, minnow traps, and electrofishing. We also measured additional environmental variables, including deforestation, lake morphometrics, altitude, and hydrological position (i.e., lake order). An information-theoretic approach to explaining the AI of G. platei revealed that by far the strongest effect was a negative association with the AI of salmonids. Lake order was also important, and using structural equation modeling, we show that this is an indirect effect naturally constraining the salmonid invasion success in Patagonia. Supporting this conclusion, an analysis of an independent data set from 106 mountain lakes in western Canada showed that introduced salmonids are indeed less successful in low-order lakes. Reproductive failure due to insufficient spawning habitat and harsh environmental conditions could be the cause of these limits to salmonid success. The existence of this effect in Chilean Patagonia suggests that low-order lakes are likely to provide natural ecological refugia for G. platei. Finally, pristine, high-order lakes should be actively protected as these have become rare and irreplaceable unspoiled references of the most diverse, natural lake ecosystems in Patagonia.

  15. Does Nature and Persistence of Substrate at a Mesohabitat Scale Matter for Chironomidae Assemblages? a Study of Two Perennial Mountain Streams in Patagonia, Argentina

    PubMed Central

    Epele, Luis Beltrán; Miserendino, María Laura; Brand, Cecilia

    2012-01-01

    Chironomid substrate—specific associations regarding the nature (organic—inorganic) and stability (stable—unstable) of different habitats were investigated at two low order Patagonian streams, during high and low water periods. Nant y Fall and Glyn rivers were visited twice (October 2007 and March 2008) and seven different habitat types were identified. A total of 60 samples were collected using a Surber sampler (0.09 m -2 and 250 µm) and a set of 23 environmental descriptors including physicochemical parameters and different fractions of particulate organic matter were assessed. 35 Chironomidae taxa were recorded with Orthocladiinae (20), Chironominae (7), and Podonominae (4) being the most well—represented subfamilies. Paratrichocladius sp. 1, Parapsectrocladius sp. 2, Parametriocnemus sp. 1, Pseudochironomus sp., and Rheotanytarsus sp. were the most abundant taxa. According to the relative preference index, at least 14 taxa showed strong affinity for a particular substrate. The structurally complex macrophyte Myriophyllum quitense supported 11 taxa compared with only five taxa found on the less complex Isoetes savatieri. Generally, stable substrates (boulders, cobbles, and rooted plants) supported significantly higher chironomids richness, abundance, and diversity than unstable ones (gravel—sand). Canonical correspondence analysis revealed that detritus (leaves, seeds, and biomass), macrophyte biomass, and secondarily hydraulic variables had high explanatory power on chironomids species composition and structure. This work suggests that more complex substrates showing persistence in the temporal dimension supported a diverse array of chironomids, meaning that the maintenance of natural habitat heterogeneity is essential for the community. Land—use practices having significant effects on ecological stream attributes such as increased turbidity, sediment deposition, and runoff patterns will alter assemblages. Understanding environmental associations

  16. Geomagnetic field for the past 5 Myr recorded in lava flows from British Columbia, Patagonia, and Mexico

    NASA Astrophysics Data System (ADS)

    Mejia, Victoria

    2005-11-01

    Paleosecular variation (PSV) and time averaged field (TAF) results recorded in lava flows younger than 5 million years are presented. The targeted areas of studies are several volcanic fields from British Columbia (mainly the Silverthrone, Garibaldi, and Wells Park volcanic fields), Southern Patagonia (the Pali-Aike volcanic field and Meseta Viscachas lavas), and Mexico (the Trans-Mexican volcanic belt and several volcanic areas in San Luis Potosi). The purpose of this investigation was to obtain high quality paleomagetic data suitable to test the presence or absence of permanent non dipolar components of the field that have been interpreted from studies carried out with less rigor. The mean directions in the areas of British Columbia and Patagonia (roughly at 50° N and 50° S latitude) coincide with the expected geocentric axial dipole (GAD) at these areas. The presence of a quadrupolar component of the field is difficult to discard because it is expected to produce only about 1° shallower inclinations. The mean direction in the area of Mexico coincides with a GAD plus a 5% quadrupole. The VGP scatter in the three areas of study coincides with Model G. The asymmetry between the northern and southern hemisphere of the present magnetic field and particularly the 20° inclination anomaly relative to GAD in Patagonia, are not observed in the paleomagnetic data obtained, implying that the present field configuration is relatively recent. The results confirm that axial components prevail in the time-averaged field.

  17. First paleoparasitological record of digenean eggs from a native deer from Patagonia Argentina (Cueva Parque Diana archaeological site).

    PubMed

    María Ornela, Beltrame; Eleonor, Tietze; Alberto Enrique, Pérez; Norma Haydeé, Sardella

    2017-02-15

    Eggs representative of a digenean species were found in coprolites belonged to an endemic deer from Patagonia. Samples were collected from the archaeological site named "Cueva Parque Diana". This site is a cave located at the Lanín National Park, Neuquén Province, Argentina. The coprolites were dated from 2370±70 to 580±60 years B.P. The eggs were ellipsoidal, operculated, yellowish and thin-shelled. Measurements (n=65) ranged from 120.0 to 142.5 (133.2±6.53) μm long and 62.5 to 87.5 (72.6±6.15) μm wide. Eggs were well-preserved and were identified as belonged to Class Trematoda, Subclass Digenea, similar to those of Fasciola hepatica or with another species not identified at present from Patagonia. This is the first report of digenean eggs from ancient deer worldwide. The present study confirms the presence of representatives of digenean species in endemic deer from Patagonia in ancient times and the presence of a trematode disease prior to the arrival of European cattle.

  18. The Usefulness of Edible and Medicinal Fabaceae in Argentine and Chilean Patagonia: Environmental Availability and Other Sources of Supply

    PubMed Central

    Molares, Soledad; Ladio, Ana

    2012-01-01

    Fabaceae is of great ethnobotanical importance in indigenous and urban communities throughout the world. This work presents a revision of the use of Fabaceae as a food and/or medicinal resource in Argentine-Chilean Patagonia. It is based on a bibliographical analysis of 27 ethnobotanical sources and catalogues of regional flora. Approximately 234 wild species grow in Patagonia, mainly (60%) in arid environments, whilst the remainder belong to Sub-Antarctic forest. It was found that 12.8% (30 species), mainly woody, conspicuous plants, are collected for food or medicines. Most of the species used grow in arid environments. Cultivation and purchase/barter enrich the Fabaceae offer, bringing it up to a total of 63 species. The richness of native and exotic species, and the existence of multiple strategies for obtaining these plants, indicates hybridization of knowledge and practices. Only 22% of the total species used are mentioned in bothcontexts of food and medicine, reflecting low-use complementation. This study suggests a significant ecological appearance and a high level of availability in shops and exchange networks in Patagonia, highlighting the need to consider the full set of environmental and socioeconomic factors in research related to the use and cultural importance of plants in regional contexts. PMID:22194774

  19. River meanders

    USGS Publications Warehouse

    Leopold, Luna Bergere; Langbein, Walter Basil

    1966-01-01

    The striking geometric regularity of a winding river is no accident. Meanders appear to be the form in which a river does the least work in turning; hence they are the most probable form a river can take

  20. Large-scale mapping of landslides in the epicentral area Loma Prieta earthquake of October 17, 1989, Santa Cruz County

    SciTech Connect

    Spittler, T.E.; Sydnor, R.H.; Manson, M.W.; Levine, P.; McKittrick, M.M.

    1990-01-01

    The Loma Prieta earthquake of October 17, 1989 triggered landslides throughout the Santa Cruz Mountains in central California. The California Department of Conservation, Division of Mines and Geology (DMG) responded to a request for assistance from the County of Santa Cruz, Office of Emergency Services to evaluate the geologic hazard from major reactivated large landslides. DMG prepared a set of geologic maps showing the landslide features that resulted from the October 17 earthquake. The principal purpose of large-scale mapping of these landslides is: (1) to provide county officials with regional landslide information that can be used for timely recovery of damaged areas; (2) to identify disturbed ground which is potentially vulnerable to landslide movement during winter rains; (3) to provide county planning officials with timely geologic information that will be used for effective land-use decisions; (4) to document regional landslide features that may not otherwise be available for individual site reconstruction permits and for future development.

  1. Geologic map of the Rio Rico and Nogales 7.5’ quadrangles, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Page, William R.; Menges, Christopher M.; Gray, Floyd; Berry, Margaret E.; Bultman, Mark W.; Cosca, Michael A.; VanSistine, D. Paco

    2016-04-15

    The objectives of our mapping were to define the geologic framework for the Nogales area and the upper Santa Cruz basin to support ongoing multidisciplinary projects. This new work will improve understanding of the Nogales Formation to more fully assess its groundwater resource potential. We significantly revised the Miocene Nogales Formation based on geologic mapping combined with new geochronologic, geophysical, and petrographic studies. 

  2. Challenges and Perspectives for Tertiary Level Hospitals in Bolivia: The case of Santa Cruz de La Sierra Department.

    PubMed

    Medici, André

    2015-01-01

    Current legislation transferred public tertiary hospitals in Bolivia from the Municipalities to the Regional Level. However, the Regional Governments are experiencing technical and financial constraints to reform infrastructure, modernize equipment and introduce reforms to allow better governance, management and sustainability of these hospitals. This articles summarizes the recent experience of the Government of Santa Cruz de la Sierra in Bolivia where five tertiary hospitals and blood bank (most of them in precarious working conditions) has been transferred in 2012 from the Municipal Government of Santa Cruz (the capital) to the Regional Government of Santa Cruz. To face the challenges, the Regional Government of Santa Cruz implement several improvements, such as contract new clinical and administrative personal, increases hospital budgetary autonomy, outsource hospitals' auxiliary services, take measures to eliminate waiting lists and make several new investments to modernize and equip the hospitals. The World Bank was contracted to evaluated the future financial sustainability of these investments and to advice the Government to propose changes to increase the hospitals' management performance. The article describes the remaining challenges in these hospitals and the proposals from the World Bank Study. In the area of quality of care, the main challenge is to improve client satisfaction and continuous outcomes monitoring and evaluation according quality standards. In the area of financing, the challenge is how to assure the sustainability of these hospitals with the current level of health financing and the insufficient financial transfers from the National Government. In the area of Governance, reforms to streamline and simplify internal processes need to be introduced in order to establish mechanisms to increase transparency and accountability, allowing the hospital to have a good administration and adequate participation of the main actors in the guidance of

  3. Scientific collections, tropical medicine and the development of entomology in Brazil: the contribution of Instituto Oswaldo Cruz.

    PubMed

    Sá, M Romero

    2008-12-01

    The entomological collection of the Institute Oswaldo Cruz is one of the most representative of neotropical insects, comprising a diverse variety of specimens of distinct taxonomic groups, including those not linked to research in tropical medicine. The present work retraces the history of the collection and reports on its main actors and their professional relationships, emphasizing the peculiarity of such an important collection still being housed in a medical research institution.

  4. Noble gas composition of subcontinental lithospheric mantle: An extensively degassed reservoir beneath Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Jalowitzki, Tiago; Sumino, Hirochika; Conceição, Rommulo V.; Orihashi, Yuji; Nagao, Keisuke; Bertotto, Gustavo W.; Balbinot, Eduardo; Schilling, Manuel E.; Gervasoni, Fernanda

    2016-09-01

    Patagonia, in the Southern Andes, is one of the few locations where interactions between the oceanic and continental lithosphere can be studied due to subduction of an active spreading ridge beneath the continent. In order to characterize the noble gas composition of Patagonian subcontinental lithospheric mantle (SCLM), we present the first noble gas data alongside new lithophile (Sr-Nd-Pb) isotopic data for mantle xenoliths from Pali-Aike Volcanic Field and Gobernador Gregores, Southern Patagonia. Based on noble gas isotopic compositions, Pali-Aike mantle xenoliths represent intrinsic SCLM with higher (U + Th + K)/(3He, 22Ne, 36Ar) ratios than the mid-ocean ridge basalt (MORB) source. This reservoir shows slightly radiogenic helium (3He/4He = 6.84-6.90 RA), coupled with a strongly nucleogenic neon signature (mantle source 21Ne/22Ne = 0.085-0.094). The 40Ar/36Ar ratios vary from a near-atmospheric ratio of 510 up to 17700, with mantle source 40Ar/36Ar between 31100-6800+9400 and 54000-9600+14200. In addition, the 3He/22Ne ratios for the local SCLM endmember, at 12.03 ± 0.15 to 13.66 ± 0.37, are higher than depleted MORBs, at 3He/22Ne = 8.31-9.75. Although asthenospheric mantle upwelling through the Patagonian slab window would result in a MORB-like metasomatism after collision of the South Chile Ridge with the Chile trench ca. 14 Ma, this mantle reservoir could have remained unhomogenized after rapid passage and northward migration of the Chile Triple Junction. The mantle endmember xenon isotopic ratios of Pali-Aike mantle xenoliths, which is first defined for any SCLM-derived samples, show values indistinguishable from the MORB source (129Xe/132Xe =1.0833-0.0053+0.0216 and 136Xe/132Xe =0.3761-0.0034+0.0246). The noble gas component observed in Gobernador Gregores mantle xenoliths is characterized by isotopic compositions in the MORB range in terms of helium (3He/4He = 7.17-7.37 RA), but with slightly nucleogenic neon (mantle source 21Ne/22Ne = 0.065-0.079). We

  5. Late Holocene environmental changes recorded in the sediments of Lago Thompson, Northern Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Fagel, Nathalie; Nuttin, Laurence; Bertrand, Sébastien; Borgniet, Geoffrey; Schmidt, Sabine; Araneda, Alberto; Torrejon, Fernando; Urrutia, Roberto

    2010-05-01

    We investigate the sedimentary record of Lago Thompson, a small lake (area 1.1 km2, watershed ~8 km2) located at an elevation of 750 masl in Northern Chilean Patagonia (45.38 °S, 71.47°W). At Present, the climate conditions around the lake are relatively dry, with annual precipitation averaging 500 mm. The goal of this study is to evaluate the natural climate variability over the Last Millennium in Northern Chilean Patagonia and its impact on the environment. The coring site was selected after a bathymetric survey using an echo-sounder. Several short cores were retrieved in 2008 using an Uwitec gravity corer: the length of the cores ranges between 124 and 132 cm. The preliminary age model is based on 4 AMS radiocarbon ages measured on bulk sediment and organic macro-remains. The radiocarbon ages demonstrate that the sediment cores cover the last 850 to 950 years. This sediment record, which is characterized by accumulation rates ranging between 1 and 3 mm/yr, can therefore be studied at decennial to centennial resolution. To reconstruct past changes in climate and the environment, we conducted a multiproxy study combining sedimentological, mineralogical and geochemical analyses (LOI 105, 550 and 950°C, biogenic silica content, magnetic susceptibility, tephrostratigraphy, bulk organic geochemistry, bulk mineralogy by X-ray diffraction, and inorganic geochemistry by ITRAX core scanner and ICP-AES). Visual descriptions and X-ray radiographies demonstrate that the sediment record is relatively undisturbed. The sediment is composed of light brown organic-rich clayey material. The lower part of the core (below 75 cm) is finely laminated whereas the upper part is more homogeneous. Magnetic susceptibility values highlight two tephra layers that represent explosive eruptions of volcanoes from the southern volcanic zone of Chile (Hudson, Cay, or Macá volcanoes). The biogenic silica content of the sediment retrieved in Lago Thompson is high (40 to 80%), and probably

  6. The last millenia sedimentary record of Lake Esponja, Northern Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Fagel, Nathalie; Araneda, Alberto; Alvarez, Denisse; Perfetti-Bolaño, Alessandra; Billy, Isabelle; Martinez, Philippe; Schmidt, Sabine; Urrutia, Roberto

    2016-04-01

    We evaluate the climate and environmental variability of Northern Chilean Patagonia during the Last Millennia, using a multi-proxy analysis of a sediment core from Lago Esponja (45°09'S, 72°08'W). The lake is located in the region of Aysen del General Carlos Ibanez del Campo, in NW Patagonia. The study focuses on a multiproxy analysis of sedimentary records. The longest core (150 cm long) was collected in 2014 at 40 m depth. The sediment, which is composed of light brown organic-rich clayey silt, was analyzed for sedimentology (grain size, magnetic susceptibility organic matter and biogenic silica content), mineralogy (X-ray diffraction) and geochemistry (elemental and isotopic analyses of C and N, XRF core-scaner at 1 mm resolution). The radiocarbon ages, measured on 3 macro-remains, demonstrate that the core covers the last 6.700 years. The sedimentation rate ranges between 0.1 mm/yr in the lower section (100-150 cm) and 0.4 mm/yr in the upper meter. Visual descriptions and Scopix radiographies show that the sediment record is finely laminated except a massive decimetric coarser and darker layer corresponding to a tephra (estimated age 700AD±50). Magnetic susceptibility (confirmed by scopix radiographies) highlights the presence of 8 additional millimetric tephra layers. The biogenic silica content of the sediment is low (mean 5%). Diatom assemblage is dominated by benthic and acidophilous species, with high saprobic values. None marked changes were observed regarding the dynamic of the lake. The high organic matter content (mean 15%) and its high C/N ratio (12.7) throughout the core indicate inputs of allochtonous and terrestrial organic matter. Such parameters present high sediment variability also marked by changes in the chemical composition. The laminations reflect changes in the allochtonous sedimentary inputs, with high terrestrial inputs during wetter conditions in relation with the Westerlies. The sedimentary records of Lago Esponja will be compared

  7. Fire history in western Patagonia from paired tree-ring fire-scar and charcoal records

    NASA Astrophysics Data System (ADS)

    Holz, A.; Haberle, S.; Veblen, T. T.; de Pol-Holz, R.; Southon, J.

    2012-03-01

    Fire history reconstructions are typically based on tree ages and tree-ring fire scars or on charcoal in sedimentary records from lakes or bogs, but rarely on both. In this study of fire history in western Patagonia (47-48° S) in southern South America (SSA) we compared three sedimentary charcoal records collected in bogs with tree-ring fire-scar data collected at 13 nearby sample sites. We examined the temporal and spatial correspondence between the two fire proxies and also compared them to published charcoal records from distant sites in SSA, and with published proxy reconstructions of regional climate variability and large-scale climate modes. Two of our three charcoal records record fire activity for the last 4 ka yr and one for the last 11 ka yr. For the last ca. 400 yr, charcoal accumulation peaks tend to coincide with high fire activity in the tree-ring fire scar records, but the charcoal records failed to detect some of the fire activity recorded by tree rings. Potentially, this discrepancy reflects low-severity fires that burn in herbaceous and other fine fuels without depositing charcoal in the sedimentary record. Periods of high fire activity tended to be synchronous across sample areas, across proxy types, and with proxy records of regional climatic variability as well as major climate drivers. Fire activity throughout the Holocene in western Patagonia has responded to regional climate variation affecting a broad region of southern South America that is teleconnected to both tropical- and high-latitude climate drivers-El Niño-Southern Oscillation and the Southern Annular Mode. An early Holocene peak in fire activity pre-dates any known human presence in our study area, and consequently implicates lightning as the ignition source. In contrast, the increased fire activity during the 20th century, which was concomitantly recorded by charcoal from all the sampled bogs and at all fire-scar sample sites, is attributed to human-set fires and is outside the

  8. Back arc basalts from Patagonia: sediment input in a distal subduction domain

    NASA Astrophysics Data System (ADS)

    Hesse, A.; Mandeville, C.; Varekamp, J. C.

    2007-12-01

    Cinder cones and lava flows from the Loncopue graben in N Patagonia (37 S) were sampled over a 180 km N-S transect. These mainly basaltic and trachybasaltic lava flows carry olivine with Cr-Al-rich spinel inclusions, while some more evolved flows carry clinopyroxene and plagioclase. Most of these rocks have between 5-8 percent MgO, and show highly variable K and LIL trace element concentrations. The rocks have up to 180 ppm Ni and 250 ppm Cr. Relative trace element abundance diagrams show negative Ta-Nb anomalies in most rocks, although their depths vary strongly. The REE patterns show LREE enrichment and most rocks have no Eu anomalies, indicating the absence of significant plagioclase fractionation. The basalts have constant U/Th values (~0.25) that are similar to those found in the nearby Copahue-Caviahue arc volcanics. Microprobe analyses of the main phases show olivine with Mg # of 80-87 and up to 2600 ppm Ni. Simulations with the Melts-pMelts programs and application of mineral-melt geothermometers suggest that most olivine phenocrysts crystallized at ~8-10 kbar pressure at temperatures of 1170-1220 oC and with 1-3 percent H2O in the melt. The Sr isotope compositions of 9 samples show a range from 0.7033 - 0.7043, which are negatively correlated with Nd isotope ratios (0.51273- 0.51292). Surprisingly, the most MgO-rich basalt has the most radiogenic Sr isotope ratio. The Pb isotope ratios, well outside the DMM range, correlate very poorly with either Sr isotope ratios or in Pb-Pb isotope graphs. The lack of correlation between degree of evolution and Sr isotope ratios as well as the primitive nature of the rocks and crystals suggest that crustal assimilation was not a major process impacting the composition of these small magma volumes. Incompatible trace element patterns of several samples resemble those of detrital sediment samples from the Pacific, which together with the isotopic data suggest that these magmas may carry a subducted sediment component

  9. Late Holocene Lacustrine Records of Climate and Vegetation Change From Southern Patagonia, Chile

    NASA Astrophysics Data System (ADS)

    Moy, C. M.; Francois, J.; Moreno, P.; Villa Martinez, R.; Dunbar, R. B.

    2004-12-01

    The westerly wind field is one of the most prominent atmospheric circulation features in the Southern Hemisphere, having a major impact on the climate of Chile and hydrographic conditions in the Southern Ocean. The latitudinal position and strength of the westerlies directly influences the amount and isotopic composition of precipitation that falls in southern Chile. Although instrumental records provide information on how the westerlies have varied over the recent past there is still an incomplete understanding of how the strength and latitudinal position of the southern westerlies have changed during the Holocene and how the wind field has varied at millennial to sub-decadal timescales. In this study we relate changes in the westerly winds to changes in water balance as recorded in closed-basin lakes. Sediment cores were obtained from Laguna Guanacos in Parque Nacional Torres del Paine (51° S, 72° W) during the austral summer of 2004 and sampled at 1-2cm intervals for pollen, charcoal, and stable isotope analysis. Laguna Guanacos is a small closed-basin lake situated in the core of westerly wind belt and is therefore sensitive to fluctuations in the strength and position of the westerlies. The sediment cores obtained from the lake reveal high concentrations of organic mater ( ˜20%) and biogenic carbonate, which is rare in Chilean Patagonia. AMS radiocarbon dates on the organic and carbonate fractions indicate that the record spans the last ˜14,000 calendar years and modern dates from core tops suggest little influence by old or dead carbon sources. Pollen analysis on the late Holocene portion of the record reveals a significant expansion of the Nothofagus forest since ˜3500 cal yr BP, suggesting an overall increase in precipitation during this interval. Millennial- and centennial-scale fluctuations in bulk carbonate content and forest and steppe pollen are superimposed upon this pattern, providing a view of a highly dynamic westerly wind regime and forest

  10. Macrohabitat of Sonora Chub (Gila ditaenia) in Sycamore Creek, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Carpenter, Jeanette; Maughan, O. Eugene

    1993-01-01

    Physical characteristics and persistence of macrohabitat used by different life stages of Sonora chub (Gila ditaenia) were determined by repeatedly measuring distinct reaches in Sycamore Creek, Santa Cruz County, Arizona, in 1990 and 1991. At the beginning of summer drought, habitats occupied by adult Sonora chub were deeper and larger than areas with only immature fish and unoccupied areas. The medians of maximum depth were 47.0 cm (1990) and 39.7 cm (1991) for habitats with adults, 21.3 cm (1990) and 22.9 cm (1991) for habitats with only immature fish, and 14.6 cm (1990) and 19.7 cm (1991) for unoccupied areas. At the end of summer drought, adults occupied habitats that were deeper and larger, and the percent decrease in area and depth was less than areas containing only immature fish or no fish. The medians of percent decrease in maximum depth were 13% (1990) and 21% (1991) for habitats with adults, 48% (1990) and 41% (1991) for habitats with only immature fish, and 42% (1990) and 33% (1991) for unoccupied areas. By the end of summer drought, habitats with only immature fish were not physically different from unoccupied areas. Loss of total surface area was highest in reaches that contained only immature fish or no fish (range = 36% to 94%). Most Sonora chub lost from evaporating surface waters were immature fish. Ephemeral and unoccupied areas had higher percentages of floating cover and coarser substrates than persistent, occupied areas.

  11. The Santa Cruz - Tarija Province of Central South America: Los Monos - Machareti(!) Petroleum System

    USGS Publications Warehouse

    Lindquist, Sandra J.

    1999-01-01

    The Los Monos - Machareti(!) total petroleum system is in the Santa Cruz - Tarija Province of Bolivia, Argentina and Paraguay. Province history is that of a Paleozoic, intracratonic, siliciclastic rift basin that evolved into a Miocene (Andean) foreland fold and thrust belt. Existing fields are typified by alternating reservoir and seal rocks in post-Ordovician sandstones and shales on anticlines. Thick Devonian and Silurian shale source rocks, depositionally and erosionally confined to this province, at a minimum have generated 4.1 BBOE known ultimate recoverable reserves (as of 1995, 77% gas, 15% condensate, 8% oil) into dominantly Carboniferous reservoirs with average 20% porosity and 156 md permeability. Major detachment surfaces within the source rocks contributed to the thin-skinned and laterally continuous nature of the deformation. Tertiary foreland burial adequate for significant source maturation coincided with the formation of compressional traps. Further hydrocarbon discovery in the fold and thrust belt is expected. In the foreland basin, higher thermal gradients and variable burial history - combined with the presence of unconformity and onlap wedges - create potential there for stratigraphic traps and pre-Andean, block-fault and forced-fold traps.

  12. History of views on the relative positions of Antarctica and South America: A 100-year tango between Patagonia and the Antarctic Peninsula

    USGS Publications Warehouse

    Miller, H.

    2007-01-01

    Discussion of continental drift around Antarctica began nearly 100 years ago. While the Gondwana connections of Antarctica to Africa and Australia have been well defined for decades, the relative pre-drift positions of the Antarctic Peninsula and Patagonia continue to be subjects of controversy. Certainly older figures, which showed a paleo-position of the Peninsula crossing over continental crust of the Falkland Plateau or even South Africa or Patagonia, are out of consideration now. But contradictory opinions remain over the relative paleo-position of the Peninsula as a more or less straight prolongation of the Patagonian Andes, versus a position parallel to Patagonia along the Pacific coast. Geological reasons are found for both opinions, but geophysical observations on the adjacent ocean floors, particularly the evolution of the Weddell Sea crust, speak for the last-mentioned reconstruction.

  13. A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs.

    PubMed

    Pol, Diego; Rauhut, Oliver W M

    2012-08-22

    Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known. Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements. The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates.

  14. Genomic patterns of diversity and divergence of two introduced salmonid species in Patagonia, South America.

    PubMed

    Narum, Shawn R; Gallardo, Pablo; Correa, Cristian; Matala, Amanda; Hasselman, Daniel; Sutherland, Ben J G; Bernatchez, Louis

    2017-04-01

    Invasive species have become widespread in aquatic environments throughout the world, yet there are few studies that have examined genomic variation of multiple introduced species in newly colonized environments. In this study, we contrast genomic variation in two salmonid species (anadromous Chinook Salmon, Oncorhynchus tshawytscha, 11,579 SNPs and resident Brook Charr Salvelinus fontinalis, 13,522 SNPs) with differing invasion success after introduction to new environments in South America relative to populations from their native range in North America. Estimates of genetic diversity were not significantly different between introduced and source populations for either species, indicative of propagule pressure that has been shown to maintain diversity in founding populations relative to their native range. Introduced populations also demonstrated higher connectivity and gene flow than those in their native range. Evidence for candidate loci under divergent selection was observed, but was limited to specific introduced populations and was not widely evident. Patterns of genomic variation were consistent with general dispersal potential of each species and therefore also the notion that life history variation may contribute to both invasion success and subsequent genetic structure of these two salmonids in Patagonia.

  15. Radar remote sensing of wind-driven land degradation processes in northeastern Patagonia.

    PubMed

    del Valle, H F; Blanco, P D; Metternicht, G I; Zinck, J A

    2010-01-01

    Wind-driven land degradation negatively impacts on rangeland production and infrastructure in the Valdes Peninsula, northeastern Patagonia. The Valdes Peninsula has the most noticeable dunefields of the Patagonian drylands. Wind erosion has been assessed at different scales in this region, but often with limited data. In general, terrain features caused by wind activity are better discriminated by active microwaves than by sensors operating in the visible and infrared regions of the electromagnetic spectrum. This paper aims to analyze wind-driven land degradation processes that control the radar backscatter observed in different sources of radar imagery. We used subsets derived from SIR-C, ERS-1 and 2, ENVISAT ASAR, RADARSAT-1, and ALOS PALSAR data. The visibility of aeolian features on radar images is mostly a function of wavelength, polarization, and incidence angle. Stabilized sand deposits are clearly observed in radar images, with defined edges but also signals of ongoing wind erosion. One of the most conspicuous features corresponds to old track sand dunes, a mixture of active and inactive barchanoid ridges and parabolic dunes. This is a clear example of deactivation of migrating dunes under the influence of vegetation. The L-band data reveal details of these sand ridges, whereas the C-band data only allow detecting a few of the larger tracks. The results of this study enable us to make recommendations about the utility of some radar sensor configurations for wind-driven land degradation reconnaissance in mid-latitude regions.

  16. A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids.

    PubMed

    Pol, Diego; Rauhut, Oliver W M; Becerra, Marcos

    2011-05-01

    Heterodontosauridae is a morphologically divergent group of dinosaurs that has recently been interpreted as one of the most basal clades of Ornithischia. Heterodontosaurid remains were previously known from the Early Jurassic of southern Africa, but recent discoveries and studies have significantly increased the geographical and temporal range for this clade. Here, we report a new ornithischian dinosaur from the Middle Jurassic Cañadón Asfalto Formation in central Patagonia, Argentina. This new taxon, Manidens condorensis gen. et sp. nov., includes well-preserved craniomandibular and postcranial remains and represents the only diagnostic ornithischian specimen yet discovered in the Jurassic of South America so far. Derived features of its anatomy indicate that Manidens belongs to Heterodontosauridae, as the sister taxon of Heterodontosaurus and other South African heterodontosaurids. The presence of posterior dentary teeth with high crowns but lacking extensive wear facets in Manidens suggests that this form represents an intermediate stage in the development of the remarkable adaptations to herbivory described for Heterodontosaurus. The dentition of Manidens condorensis also has autapomorphies, such as asymmetrically arranged denticles in posterior teeth and a mesially projected denticle in the posteriormost teeth. At an estimated total length of 60-75 cm, Manidens furthermore confirms the small size of basal heterodontosaurids.

  17. A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs

    PubMed Central

    Pol, Diego; Rauhut, Oliver W. M.

    2012-01-01

    Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known. Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements. The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates. PMID:22628475

  18. Bacterial composition of microbial mats in hot springs in Northern Patagonia: variations with seasons and temperature.

    PubMed

    Mackenzie, Roy; Pedrós-Alió, Carlos; Díez, Beatriz

    2013-01-01

    Seasonal shifts in bacterial diversity of microbial mats were analyzed in three hot springs (39-68 °C) of Patagonia, using culture-independent methods. Three major bacterial groups were detected in all springs: Phyla Cyanobacteria and Bacteroidetes, and Order Thermales. Proteobacteria, Acidobacteria and Green Non-Sulfur Bacteria were also detected in small amounts and only in some samples. Thermophilic filamentous heterocyst-containing Mastigocladus were dominant Cyanobacteria in Porcelana Hot Spring and Geyser, and Calothrix in Cahuelmó, followed by the filamentous non-heterocyst Leptolyngbya and Oscillatoria. Bacteroidetes were detected in a wide temperature range and their relative abundance increased with decreasing temperature in almost all samples. Two Meiothermus populations with different temperature optima were found. Overall, fingerprinting analysis with universal bacterial primers showed high similarities within each hot spring despite differences in temperature. On the other hand, Cahuelmó Hot Spring showed a lower resemblance among samples. Porcelana Hot Spring and Porcelana Geyser were rather similar to each other, possibly due to a common geological substrate given their geographic proximity. This was even more evident with specific cyanobacterial primers. The different geological substrate and the seawater influence in Cahuelmó might have caused the differences in the microbial community structure with the other two hot springs.

  19. An Assessment of Oil Pollution in the Coastal Zone of Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Commendatore, Marta Graciela; Esteves, José Luis

    2007-11-01

    The Patagonian coast is considered a relatively pristine environment. However, studies conducted along coastal Patagonia have showed hydrocarbon pollution mostly concentrated at ports that have fishing, oil loading, general merchant, and/or tourist activities. A high value of total aliphatic hydrocarbons (TAH) was found at the Rawson fishing port (741 μg/g dw). In other ports with and without petroleum-related activities, hydrocarbon values were approximately 100 μg/g dw. The highest values for TAH and total aromatic hydrocarbons (TArH) were found in Faro Aristizábal, north of San Jorge gulf (1304 and 737 μg/g dw, respectively). This is very likely the result of petroleum-related activities at the Comodoro Rivadavia, Caleta Cordova, and Caleta Olivia ports located within this gulf. In other coastal areas away from potential anthropogenic sources, hydrocarbon values were less than 2 and 3 μg/g dw for TAH and TArH, respectively. This review of published and unpublished information suggests that ports are important oil pollution sources in the Patagonian coast. More detailed studies are needed to evaluate the area affected by port activities, to understand the mechanisms of hydrocarbon distribution in surrounding environments, and to assess bioaccumulation in marine organisms. Despite that some regulations exist to control oil pollution derived from port and docked vessel activities, new and stricter management guidelines should be implemented.

  20. Muscular reconstruction and functional morphology of the forelimb of early Miocene sloths (Xenarthra, Folivora) of Patagonia.

    PubMed

    Toledo, Néstor; Bargo, M Susana; Vizcaíno, Sergio F

    2013-02-01

    Early Miocene sloths are represented by a diversity of forms ranging from 38 to 95 kg, being registered mainly from Santacrucian Age deposits in southern-most shores of Patagonia, Argentina. Their postcranial skeleton differs markedly in shape from those of their closest living relatives (arboreal forms of less than 10 kg), Bradypus and Choloepus. In order to gain insight on functional properties of the Santacrucian sloths forelimb, musculature was reconstructed and a comparative, qualitative morphofunctional analysis was performed, allowing proposing hypotheses about biological role of the limb in substrate preferences, and locomotor strategies. The anatomy of the forelimb of Santacrucian sloths resembles more closely extant anteaters such as Tamandua and Myrmecophaga, due to the robustness of the elements, development of features related to attachment of ligaments and muscles, and conservative, pentadactylous, and strong-clawed manus. The reconstructed forelimb musculature was very well developed and resembles that of extant Pilosa (especially anteaters), although retaining the basic muscular configuration of generalized mammals. This musculature allowed application of powerful forces, especially in adduction of the forelimb, flexion and extension of the antebrachium, and manual prehension. These functional properties are congruent with both climbing and digging activities, and provide support for proposed Santacrucian sloths as good climbing mammals, possibly arboreal or semiarboreal, being also capable diggers. Their climbing strategies were limited, thus these forms relied mainly on great muscular strength and curved claws of the manus to move cautiously on branches.

  1. Analysis of admixture and genetic structure of two Native American groups of Southern Argentinean Patagonia.

    PubMed

    Sala, Andrea; Corach, Daniel

    2014-03-01

    Argentinean Patagonia is inhabited by people that live principally in urban areas and by small isolated groups of individuals that belong to indigenous aboriginal groups; this territory exhibits the lowest population density of the country. Mapuche and Tehuelche (Mapudungun linguistic branch), are the only extant Native American groups that inhabit the Argentinean Patagonian provinces of Río Negro and Chubut. Fifteen autosomal STRs, 17 Y-STRs, mtDNA full length control region sequence and two sets of Y and mtDNA-coding region SNPs were analyzed in a set of 434 unrelated individuals. The sample set included two aboriginal groups, a group of individuals whose family name included Native American linguistic root and urban samples from Chubut, Río Negro and Buenos Aires provinces of Argentina. Specific Y Amerindian haplogroup Q1 was found in 87.5% in Mapuche and 58.82% in Tehuelche, while the Amerindian mtDNA haplogroups were present in all the aboriginal sample contributors investigated. Admixture analysis performed by means of autosomal and Y-STRs showed the highest degree of admixture in individuals carrying Mapuche surnames, followed by urban populations, and finally by isolated Native American populations as less degree of admixture. The study provided novel genetic information about the Mapuche and Tehuelche people and allowed us to establish a genetic correlation among individuals with Mapudungun surnames that demonstrates not only a linguistic but also a genetic relationship to the isolated aboriginal communities, representing a suitable proxy indicator for assessing genealogical background.

  2. Origin of the DUPAL anomaly in mantle xenoliths of Patagonia (Argentina) and geodynamic consequences

    NASA Astrophysics Data System (ADS)

    Mazzucchelli, Maurizio; Cipriani, Anna; Hémond, Christophe; Zanetti, Alberto; Bertotto, Gustavo Walter; Cingolani, Carlos Alberto

    2016-04-01

    The sub-continental lithospheric mantle of South America has been known for some time to carry the DUPAL isotope anomaly as seen in volcanics from the Paraná volcanic province. However, this has not allowed discriminating whether the DUPAL anomaly is a primary feature of the mantle source or acquired during the upwelling and emplacement of the primary magmas. We discovered mantle xenoliths from the Tres Lagos location in Patagonia that carry evidence of percolation by metasomatic melts that imparted the DUPAL isotope anomaly signature. We discuss a model that requires four isotope components (LCC, EM2, HIMU and DM) to account for the Sr, Nd and Pb isotope variability of our samples. We propose that upwelling of hot astenosphere during the Miocene could have triggered the melting of the LCC and EM2 components carrying the DUPAL anomaly, previously entrained in the subcontinental mantle by subduction. These ascending melts would have then metasomatised the local SCLM characterised by DMM and HIMU geochemical affinity generating the hybrid DUPAL-bearing mantle sampled by the Tres Lagos xenoliths.

  3. Nuisance Ecology: Do Scavenging Condors Exact Foraging Costs on Pumas in Patagonia?

    PubMed Central

    Elbroch, L. Mark; Wittmer, Heiko U.

    2013-01-01

    Predation risk describes the energetic cost an animal suffers when making a trade off between maximizing energy intake and minimizing threats to its survival. We tested whether Andean condors (Vultur gryphus) influenced the foraging behaviors of a top predator in Patagonia, the puma (Puma concolor), in ways comparable to direct risks of predation for prey to address three questions: 1) Do condors exact a foraging cost on pumas?; 2) If so, do pumas exhibit behaviors indicative of these risks?; and 3) Do pumas display predictable behaviors associated with prey species foraging in risky environments? Using GPS location data, we located 433 kill sites of 9 pumas and quantified their kill rates. Based upon time pumas spent at a carcass, we quantified handling time. Pumas abandoned >10% of edible meat at 133 of 266 large carcasses after a single night, and did so most often in open grasslands where their carcasses were easily detected by condors. Our data suggested that condors exacted foraging costs on pumas by significantly decreasing puma handling times at carcasses, and that pumas increased their kill rates by 50% relative to those reported for North America to compensate for these losses. Finally, we determined that the relative risks of detection and associated harassment by condors, rather than prey densities, explained puma “giving up times” (GUTs) across structurally variable risk classes in the study area, and that, like many prey species, pumas disproportionately hunted in high-risk, high-resource reward areas. PMID:23301093

  4. Latest Pleistocene and Holocene glacial events in the Colonia valley, Northern Patagonia Icefield, southern Chile

    USGS Publications Warehouse

    Nimick, David A.; Mcgrath, Daniel; Mahan, Shannon; Friesen, Beverly A.; Leidich, Jonathan

    2016-01-01

    The Northern Patagonia Icefield (NPI) is the primary glaciated terrain worldwide at its latitude (46.5–47.5°S), and constraining its glacial history provides unique information for reconstructing Southern Hemisphere paleoclimate. The Colonia Glacier is the largest outlet glacier draining the eastern NPI. Ages were determined using dendrochronology, lichenometry, radiocarbon, cosmogenic 10Be and optically stimulated luminescence. Dated moraines in the Colonia valley defined advances at 13.2 ± 0.95, 11.0 ± 0.47 and 4.96 ± 0.21 ka, with the last being the first constraint on the onset of Neoglaciation for the eastern NPI from a directly dated landform. Dating in the tributary Cachet valley, which contains an ice-dammed lake during periods of Colonia Glacier expansion, defined an advance at ca. 2.95 ± 0.21 ka, periods of advancement at 810 ± 49 cal a BP and 245 ± 13 cal a BP, and retreat during the intervening periods. Recent Colonia Glacier thinning, which began in the late 1800s, opened a lower-elevation outlet channel for Lago Cachet Dos in ca. 1960. Our data provide the most comprehensive set of Latest Pleistocene and Holocene ages for a single NPI outlet glacier and expand previously developed NPI glacial chronologies.

  5. Mercury and selenium in the food web of Lake Nahuel Huapi, Patagonia, Argentina.

    PubMed

    Arcagni, Marina; Rizzo, Andrea; Juncos, Romina; Pavlin, Majda; Campbell, Linda M; Arribére, María A; Horvat, Milena; Ribeiro Guevara, Sergio

    2017-01-01

    Despite located far from point sources of Hg pollution, high concentrations were recorded in plankton from the deep oligotrophic Lake Nahuel Huapi, located in North Patagonia. Native and introduced top predator fish with differing feeding habits are a valuable economic resource to the region. Hence, Hg and Se trophic interactions and pathways to these fish were assessed in the food web of this lake at three sites, using stable nitrogen and carbon isotopes. As expected based on the high THg in plankton, mercury did not biomagnify in the food web of Lake Nahuel Huapi, as most of the THg in plankton is in the inorganic form. As was observed in other aquatic systems, Se did not biomagnify either. When trophic pathways to top predator fish were analyzed, they showed that THg biomagnified in the food chains of native fish but biodiluted in the food chains of introduced salmonids. A more benthic diet, typical of native fish, resulted in higher [THg] bioaccumulation than a more pelagic or mixed diet, as in the case of introduced fish. Se:THg molar ratios were higher than 1 in all the fish species, indicating that Se might be offering a natural protection against Hg toxicity.

  6. Ancient parasites from endemic deer from "CUEVA PARQUE DIANA" archeological site, Patagonia, Argentina.

    PubMed

    Beltrame, María Ornela; Tietze, Eleonor; Pérez, Alberto Enrique; Bellusci, Agustín; Sardella, Norma Haydée

    2017-03-24

    The narrow Andean-Patagonian temperate rainforest strip in the west of southern South America is inhabited by two endemic species of cervids, the southern pudu (Pudu puda) and the huemul (Hippocamelus bisulcus), both cataloged as near threatened and threatened species, respectively. One of the possible causes of their declined number is the susceptibility to livestock diseases. Significant zooarchaeological records of both deer have been found throughout the Holocene from Patagonia. The present contribution reports the first paleoparasitological results obtained from coprolites of endemic deer from the archeological site "Cueva Parque Diana," Neuquén Province, Argentina, and discusses the possible diseases found in ancient times. Thirty-four coprolites were fully processed, rehydrated, homogenized, sieved, subjected to spontaneous sedimentation, and examined by light microscopy. Thirty samples contained parasite remains. The presence of diverse parasitic diseases such as trematodioses, metastrongylosis, trichuriosis, strongylida gastroenteritis, dioctophymosis, and coccidiosis which could cause diseases in deer previous to the arrival of European livestock and the presence of zoonotic diseases in the hunters-gatherers and fishermen are discussed.

  7. Gamma irradiation as a phytosanitary treatment for fresh pome fruits produced in Patagonia

    NASA Astrophysics Data System (ADS)

    Pérez, J.; Lires, C.; Horak, C.; Pawlak, E.; Docters, A.; Kairiyama, E.

    2009-07-01

    Argentina produces 1.8 million tons/year of apples ( Malus domestica L.) and pears ( Pyrus communis L.) in the Patagonia region. Cydia pomonella, codling moth, and Grapholita molesta, Oriental fruit moth, ( Lepidoptera: Tortricidae) are quarantine pests in pome fruits. Irradiation is a promising phytosanitary treatment because a dose of 200 Gy completely prevents pest adult emergence. A pilot irradiation process of commercially packaged 'Red Delicious' apples and 'Packham's Triumph' pears was performed in an irradiation facility with a Cobalt 60 source. Quality analyses were carried out at 0, 2, 4, 6 and 8 months of storage (1 °C, RH 99%) to evaluate fruit tolerance at 200, 400 and 800 Gy. Irradiation at 200 and 400 Gy had no undesirable effects on fruit quality (pulp firmness, external colour, soluble solids content (SSC), titratable acidity (TA) and sensory evaluations). Irradiation of 'Red Delicious' apples and 'Packham's Triumph' pears can be applied as a commercial quarantine treatment with a minimum absorbed dose of 200 Gy (to control codling moth and Oriental fruit moth) and <800 Gy (according to quality results).

  8. The Domuyo volcanic system: An enormous geothermal resource in Argentine Patagonia

    NASA Astrophysics Data System (ADS)

    Chiodini, Giovanni; Liccioli, Caterina; Vaselli, Orlando; Calabrese, Sergio; Tassi, Franco; Caliro, Stefano; Caselli, Alberto; Agusto, Mariano; D'Alessandro, Walter

    2014-03-01

    A geochemical survey of the main thermal waters discharging in the southwestern part of the Domuyo volcanic complex (Argentina), where the latest volcanic activity dates to 0.11 Ma, has highlighted the extraordinarily high heat loss from this remote site in Patagonia. The thermal water discharges are mostly Na-Cl in composition and have TDS values up to 3.78 g L- 1 (El Humazo). A simple hydrogeochemical approach shows that 1,100 to 1,300 kg s- 1 of boiling waters, which have been affected by shallow steam separation, flow into the main drainage of the area (Rio Varvarco). A dramatic increase of the most conservative species such as Na, Cl and Li from the Rio Varvarco from upstream to downstream was observed and related solely to the contribution of hydrothermal fluids. The equilibrium temperatures of the discharging thermal fluids, calculated on the basis of the Na-K-Mg geothermometer, are between 190 °C and 230 °C. If we refer to a liquid originally at 220 °C (enthalpy = 944 J g- 1), the thermal energy release can be estimated as high as 1.1 ± 0.2 GW, a value that is much higher than the natural release of heat in other important geothermal fields worldwide, e.g., Mutnovsky (Russia), Wairakei (New Zealand) and Lassen Peak (USA). This value is the second highest measured advective heat flux from any hydrothermal system on Earth after Yellowstone.

  9. Environmental effects on grass-endophyte associations in the harsh conditions of south Patagonia.

    PubMed

    Novas, M Victoria; Collantes, Marta; Cabral, Daniel

    2007-07-01

    Cool-season grasses are frequently infected by Neotyphodium endophytes and this association is often considered as a mutualistic symbiosis. We examined the incidence of Neotyphodium in populations of Bromus setifolius, Phleum alpinum and Poa spiciformis, native and wide-spread grasses from south Patagonia, Argentina. The incidence of 36 populations of Bromus setifolius was studied in association with climatic and soil variables. 31 populations of Ph. alpinum were sampled in five different plant communities. Seventeen populations of P. spiciformis were sampled in three different plant communities. The association between incidence and climatic variables in Ph. alpinum and between incidence and soil fertility in P. spiciformis was investigated. In B. setifolius endophyte incidence was positively correlated with annual average rainfall contrary to the results found in Ph. alpinum. All the populations of P. spiciformis were infected by endophytes and the incidence was associated with plant community. The Neotyphodium-grass interaction is variable in natural populations, supporting the increasing evidence that the Neotyphodium-host interaction depends, in many cases, on the environmental conditions. Field observations suggest that in detrimental low growth conditions the association is not favoured, leading to a decrease in the endophyte frequency of infection or even to the complete loss of the association.

  10. Large Cretaceous sphenodontian from Patagonia provides insight into lepidosaur evolution in Gondwana.

    PubMed

    Apesteguía, Sebastián; Novas, Fernando E

    2003-10-09

    Sphenodontian reptiles successfully radiated during Triassic and Jurassic times, but were driven almost to extinction during the Cretaceous period. The sparse Early Cretaceous record of sphenodontians has been interpreted as reflecting the decline of the group in favour of lizards, their suspected ecological successors. However, recent discoveries in Late Cretaceous beds in Patagonia partially modify this interpretation. Numerous skeletons of a new sphenodontian, Priosphenodon avelasi gen. et sp. nov., were collected from a single locality in the Cenomanian-Turonian Candeleros Formation, where it is more abundant than any other tetrapod group recorded in the quarry (for example, Crocodyliformes, Serpentes, Dinosauria and Mammalia). Adult specimens of Priosphenodon reached one metre in length, larger than any previously known terrestrial sphenodontian. Here we propose, using available evidence, that sphenodontians were not a minor component of the Cretaceous terrestrial ecosystems of South America, and that their ecological replacement by squamates was delayed until the early Tertiary. The new discovery helps to bridge the considerable gap in the fossil record (around 120 million years) that separates the Early Cretaceous sphenodontians from their living relatives (Sphenodon).

  11. A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids.

    PubMed

    Novas, Fernando E; de Valais, Silvina; Vickers-Rich, Pat; Rich, Tom

    2005-05-01

    The Cretaceous Carcharodontosauridae is the latest clade of carnosaurs, including the largest predatory dinosaurs yet recorded. Albeit spectacular for their size, the skeletal anatomy of these theropods remains poorly-known, and their diversity was until recently restricted to two Cenomanian species: the highly derived Giganotosaurus carolinii, from southern South America, and the incompletely known Carcharodontosaurus saharicus, from northern Africa. Here we describe an older and basal member of the group, Tyrannotitan chubutensis gen. et sp. nov., from Aptian strata of Patagonia, Argentina. The new taxon gives new insights into the systematics and evolution of carcharodontosaurids and offers a better understanding of the evolution of Southern theropod faunas. We suggest that carcharodontosaurids radiated in Gondwana sharing with spinosaurids the role of top-predators until their extinction in Cenomanian-Turonian times. During this interval, the diplodocoid sauropods and giant titanosaurians went extinct (probably as part of a global-scale crisis), and the smaller abelisaurid theropods took dominance, reigning until the end of the Cretaceous. Electronic Supplementary Material is available.

  12. Shell shape variation in the Nassariid Buccinanops globulosus in northern Patagonia

    NASA Astrophysics Data System (ADS)

    Avaca, María Soledad; Narvarte, Maite; Martín, Pablo; van der Molen, Silvina

    2013-09-01

    Morphological variation among natural populations is a phenomenon commonly observed in marine invertebrates and well studied, particularly, in shelled gastropods. The nassariid Buccinanops globulosus is interesting to study shell shape variation because it exhibits strong interpopulation differences in life history features, including maximum size, fecundity and growth rate. In this study, we examined the pattern of variation in size and shell shape among populations and between sexes of B. globulosus (Bahía San Antonio 40°29'S 63°01'W, Playa Villarino 40°45'S 64°40'W and Bahía Nueva 42°46'S 65°02'W). In particular, we used geometric morphometric techniques to test: (1) whether the two components of shell morphology (size and shape) are independent and (2) whether shape differences between sexes are consistently found among populations, regardless of their body sizes. Our results show shell shape variation between the populations of B. globulosus of northern Patagonia. Intra-specific shell shape variation is affected by body size, indicating allometry. Regardless of the size differences, individuals from Playa Villarino have high-spired shells, and shorter apertures and wider columellar area than individuals from the other populations. Also, sex-related shape differences were consistently found at each population, thus suggesting a common sexual dimorphism in shell morphology for this species. The functional significance of the variability found is discussed in terms of the flexibility of developmental programmes for morphology as well as the evolution of phenotypic plasticity.

  13. Physiological characterization of Saccharomyces uvarum and Saccharomyces eubayanus from Patagonia and their potential for cidermaking.

    PubMed

    González Flores, Melisa; Rodríguez, María Eugenia; Oteiza, Juan Martín; Barbagelata, Raúl Jorge; Lopes, Christian Ariel

    2017-03-01

    A diversity of yeast strains belonging to the cryotolerant fermentative species S. uvarum and S. eubayanus have been recovered from natural habitats and traditional fermentations in North Patagonia. The aim of this work was to evaluate the most relevant physiological features in a set of Patagonian strains belonging to S. uvarum and S. eubayanus, in order to analyze their potentiality to be used as starter cultures for cidermaking elaborated at low temperature. We evidenced that S. uvarum strains isolated from natural habitats (Araucaria araucana bark) showed similar physiological features to S. eubayanus strains obtained from the same habitat, and different from S. uvarum strains from fermentative environments (apple chichas). We also confirm the capacity of S. uvarum to produce high glycerol levels, low acetic acid and elevated production of the higher alcohol 2-phenylethanol and 2-phenylethyl acetate and demonstrated similar properties in S. eubayanus. Finally, we evidenced for the first time the antagonistic activity of S. eubayanus and selected three strains (two S. uvarum and one S. eubayanus) bearing the best combination of features to be used as a starter culture in cidermaking.

  14. Saccharomyces uvarum is responsible for the traditional fermentation of apple chicha in Patagonia.

    PubMed

    Rodríguez, Maria E; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Querol, Amparo; Lopes, Christian A

    2017-01-01

    Apple chicha is a fresh low alcoholic beverage elaborated by aboriginal communities of Andean Patagonia (Argentina and Chile). In the present work, we identified the yeast microbiota associated with this fermentation, and characterized genetically those belonging to the genus Saccharomyces. Both Saccharomyces cerevisiae and S. uvarum were found in the analyzed fermentations. Phylogenetic and population structure analyses based on genes sequence analysis were carried out for both S. cerevisiae and S. uvarum strains obtained in this study and a set of additional strains from diverse origins. The results demonstrate that S. cerevisiae strains from apple chicha belong to the big group of wine/European strains of this species, while S. uvarum strains were included in the Holartic population of this species. Additionally, some S. uvarum strains from chichas evidenced as an admixture of both pure Holartic and pure South American populations. Our results suggest that Holartic strains could have been introduced in South America together with the domestication of apple trees by Mapuche communities. This Holartic population suffered admixis with the naturally present South American population of this species, originating strains bearing genetic features from the two populations, detectable in both chichas and natural habitats.

  15. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean

    PubMed Central

    Glasser, Neil F.; Jansson, Krister N.; Duller, Geoffrey A. T.; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-01-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface “hosing” to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate. PMID:26869235

  16. In Vitro Antimicrobial Activity of Embothrium coccineum Used as Traditional Medicine in Patagonia against Multiresistant Bacteria.

    PubMed

    Canales, Nicole; Montenegro, Iván; Párraga, Mario; Olguín, Yusser; Godoy, Patricio; Werner, Enrique; Madrid, Alejandro

    2016-10-31

    Embothrium coccineum J.R. Forst. & G. Forst is an evergreen tree that has been used as a folk remedy for the treatment of neuralgia, tooth pains, wound healing, and glandular conditions, as well as an antiseptic agent against bacterial infection. The antibacterial activities of sequential extracts (hexane, dichloromethane, ethyl acetate, and ethanol) from the leaves of E. coccineum were evaluated by means of the micro-dilution assay against six (Escherichia coli; Klebsiella pneumoniae; Proteus mirabilis; Pseudomonas aeruginosa; Staphylococcus aureus and Streptococcus pyogenes) multiresistant bacteria strains. Ethyl acetate extract showed the best spectra of antibacterial activity against all tested bacteria, and was analyzed by gas chromatography-mass spectrometry (GC-MS) for its composition. The results of the present work provide useful baseline information for the potential development and use of nanoparticles and/or nanofibers doped with extracts of E. coccineum in the fight against multiresistant bacteria, which would allow the validation of the traditional use of E. coccineum by native peoples of Patagonia as an antimicrobial agent in the biomedical Field.

  17. An assessment of oil pollution in the coastal zone of patagonia, Argentina.

    PubMed

    Commendatore, Marta Graciela; Esteves, José Luis

    2007-11-01

    The Patagonian coast is considered a relatively pristine environment. However, studies conducted along coastal Patagonia have showed hydrocarbon pollution mostly concentrated at ports that have fishing, oil loading, general merchant, and/or tourist activities. A high value of total aliphatic hydrocarbons (TAH) was found at the Rawson fishing port (741 microg/g dw). In other ports with and without petroleum-related activities, hydrocarbon values were approximately 100 microg/g dw. The highest values for TAH and total aromatic hydrocarbons (TArH) were found in Faro Aristizábal, north of San Jorge gulf (1304 and 737 microg/g dw, respectively). This is very likely the result of petroleum-related activities at the Comodoro Rivadavia, Caleta Cordova, and Caleta Olivia ports located within this gulf. In other coastal areas away from potential anthropogenic sources, hydrocarbon values were less than 2 and 3 microg/g dw for TAH and TArH, respectively. This review of published and unpublished information suggests that ports are important oil pollution sources in the Patagonian coast. More detailed studies are needed to evaluate the area affected by port activities, to understand the mechanisms of hydrocarbon distribution in surrounding environments, and to assess bioaccumulation in marine organisms. Despite that some regulations exist to control oil pollution derived from port and docked vessel activities, new and stricter management guidelines should be implemented.

  18. Stomach nematodes of three sympatric species of anatid birds off the coast of Patagonia.

    PubMed

    Agüero, M L; Gilardoni, C; Cremonte, F; Diaz, J I

    2016-11-01

    The present study focuses on the nematode community in the stomachs of three sympatric anatid bird species from the Central Patagonian coast, Argentina. The bird species include the Chubut steamer duck, Tachyeres leucocephalus, the crested duck, Lophonetta specularioides, and the black-necked swan, Cygnus melancoryphus. Up to 138 nematodes representing five species were recovered from 10 of the 13 ducks examined, with an overall prevalence of 77% and a mean intensity of 13.8. Nematodes isolated from the gizzard were Streptocara formosensis and Sciadiocara legendrei (Acuariidae) in T. leucocephalus, and Epomidiostomum vogelsangi (Amidostomatidae) in C. melancoryphus, whereas Echinuria uncinata (Acuariidae) and Tetrameres (Petrowimeres) fissispina (Tetrameriidae) were found in the proventiculus of L. specularioides. In particular, S. legendrei was registered for the first time in South America and T. leucocephalus, whereas T. fissispina represents a new record in Argentina and L. specularioides. Moreover, E. vogelsangi and E. uncinata were isolated in Patagonia for the first time. The birds studied herein are sympatric in their distribution, and two of them are syntopic breeders; however, they were infected with different parasite species. This situation could be partially due to their diet or their seasonal movements, or a combination of both. Despite the low number of hosts examined, this work enhances our knowledge about parasites from a frequently occurring group of birds on the Patagonian coast, a subject that has not been studied extensively in South America.

  19. Discovery of a short-necked sauropod dinosaur from the Late Jurassic period of Patagonia.

    PubMed

    Rauhut, Oliver W M; Remes, Kristian; Fechner, Regina; Cladera, Gerardo; Puerta, Pablo

    2005-06-02

    Sauropod dinosaurs are one of the most conspicuous groups of Mesozoic terrestrial vertebrates. They show general trends towards an overall increase in size and elongation of the neck, by means of considerable elongation of the length of individual vertebrae and a cervical vertebra count that, in some cases, increases to 19 (ref. 1). The long neck is a particular hallmark of sauropod dinosaurs and is usually regarded as a key feeding adaptation. Here we describe a new dicraeosaurid sauropod, from the latest Jurassic period of Patagonia, that has a particularly short neck. With a neck that is about 40% shorter than in other known dicraeosaurs, this taxon demonstrates a trend opposite to that seen in most sauropods and indicates that the ecology of dicraeosaurids might have differed considerably from that of other sauropods. The new taxon indicates that there was a rapid radiation and dispersal of dicraeosaurids in the Late Jurassic of the Southern Hemisphere, after the separation of Gondwana from the northern continents by the late Middle Jurassic.

  20. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean.

    PubMed

    Glasser, Neil F; Jansson, Krister N; Duller, Geoffrey A T; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-02-12

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface "hosing" to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate.

  1. Echinostomatid larval stages in Lymnaea viatrix (Gastropoda: Pulmonata) from southwest Patagonia, Argentina.

    PubMed

    Prepelitchi, Lucila; de Núñez, Margarita Ostrowski

    2007-04-01

    The partial life cycle of an echinostomatid found in Lymnaea viatrix from Patagonia, Argentina, was experimentally clarified. Emerging cercariae were exposed to laboratory-reared specimens of Biomphalaria sp. Metacercariae obtained from both naturally and experimentally infected snails were force-fed to chicks. Specimens recovered from the chicks belong to Echinoparyphium sp. on the basis of morphological features. The studied species possesses 43 collar spines arranged in 4-4-27-4-4 at all stages, a cercariae with over 100 small corpuscles in the excretory system, a cercariae tail without finfolds, and a metacercariae with a thin cyst wall. The present species cannot be assigned to Echinoparyphium megacirrus despite their morphological similarity because of differences in the habitats of L. viatrix and the intermediate hosts of E. megacirrus, namely Chilina dombeiana, Diplodon chilensis, and Temnocephala chilensis. More information on some life cycle stages and on the ecology of the intermediate hosts is needed to clarify the taxonomic status of the parasite. This study represents the first detailed description of parasites other than Fasciola hepatica in L. viatrix from Argentina.

  2. Nuisance ecology: do scavenging condors exact foraging costs on pumas in Patagonia?

    PubMed

    Elbroch, L Mark; Wittmer, Heiko U

    2013-01-01

    Predation risk describes the energetic cost an animal suffers when making a trade off between maximizing energy intake and minimizing threats to its survival. We tested whether Andean condors (Vultur gryphus) influenced the foraging behaviors of a top predator in Patagonia, the puma (Puma concolor), in ways comparable to direct risks of predation for prey to address three questions: 1) Do condors exact a foraging cost on pumas?; 2) If so, do pumas exhibit behaviors indicative of these risks?; and 3) Do pumas display predictable behaviors associated with prey species foraging in risky environments? Using GPS location data, we located 433 kill sites of 9 pumas and quantified their kill rates. Based upon time pumas spent at a carcass, we quantified handling time. Pumas abandoned >10% of edible meat at 133 of 266 large carcasses after a single night, and did so most often in open grasslands where their carcasses were easily detected by condors. Our data suggested that condors exacted foraging costs on pumas by significantly decreasing puma handling times at carcasses, and that pumas increased their kill rates by 50% relative to those reported for North America to compensate for these losses. Finally, we determined that the relative risks of detection and associated harassment by condors, rather than prey densities, explained puma "giving up times" (GUTs) across structurally variable risk classes in the study area, and that, like many prey species, pumas disproportionately hunted in high-risk, high-resource reward areas.

  3. Characterization and degradation process of sludge profiles inside a facultative pond (Patagonia, Argentina).

    PubMed

    Faleschini, M; Esteves, J L

    2011-01-01

    To investigate the characteristics and degradation process in sludge profile, three sampling sessions were made in three different places inside the primary facultative pond of Puerto Madryn city, which was located in a region with a temperate climate in coastal Patagonia (Argentina). The sludge showed an extremely negative redox potential (between -441 and -282 mV) and elevated water content and organic matter concentration, ranging from 83.3 to 97.1% for porosity and from 22.5 to 64.4% for organic matter. The surface layer at the Outlet station during the summer showed the greatest concentration of pigments, reaching a maximum value of 10.6 mg/g for chlorophyll-a and 40.9 mg/g for phaeophytin, and a fast diminution with sediment depth. The important concentration of pigment in the surface layer, coincident with phytoplankton bloom in the water column, could support the importance of nitrogen removal via uptake and organic sedimentation in the water column. In warm months the degradation rate was clear, as reflected in a decrease in sediment layer, and even part of the clay bottom was captured inside an 8 cm core sample, registering extremely low concentrations of pigments, carbohydrates, proteins and lipids. The season and the degree of treatment have an influence on sludge characteristics and the organic matter degradation process.

  4. A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids

    NASA Astrophysics Data System (ADS)

    Pol, Diego; Rauhut, Oliver W. M.; Becerra, Marcos

    2011-05-01

    Heterodontosauridae is a morphologically divergent group of dinosaurs that has recently been interpreted as one of the most basal clades of Ornithischia. Heterodontosaurid remains were previously known from the Early Jurassic of southern Africa, but recent discoveries and studies have significantly increased the geographical and temporal range for this clade. Here, we report a new ornithischian dinosaur from the Middle Jurassic Cañadón Asfalto Formation in central Patagonia, Argentina. This new taxon, Manidens condorensis gen. et sp. nov., includes well-preserved craniomandibular and postcranial remains and represents the only diagnostic ornithischian specimen yet discovered in the Jurassic of South America so far. Derived features of its anatomy indicate that Manidens belongs to Heterodontosauridae, as the sister taxon of Heterodontosaurus and other South African heterodontosaurids. The presence of posterior dentary teeth with high crowns but lacking extensive wear facets in Manidens suggests that this form represents an intermediate stage in the development of the remarkable adaptations to herbivory described for Heterodontosaurus. The dentition of Manidens condorensis also has autapomorphies, such as asymmetrically arranged denticles in posterior teeth and a mesially projected denticle in the posteriormost teeth. At an estimated total length of 60-75 cm, Manidens furthermore confirms the small size of basal heterodontosaurids.

  5. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Glasser, Neil F.; Jansson, Krister N.; Duller, Geoffrey A. T.; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-02-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface “hosing” to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate.

  6. New species of dictyostelids from Patagonia and Tierra del Fuego, Argentina.

    PubMed

    Vadell, Eduardo M; Cavender, James C; Romeralo, Maria; Edwards, Sally M; Stephenson, Steven L; Baldauf, Sandra L

    2011-01-01

    In late Jan and early Feb 2005 samples for isolation of dictyostelid cellular slime molds (dictyostelids) were collected in five different provinces and from six national parks (all located 39-55°S) in Patagonia and Tierra del Fuego, Argentina. Southern beech (Nothofagus) forests represented the primary vegetation type investigated, but some samples were obtained from Patagonian steppe, alpine meadows, Valdivian temperate rainforests and coniferous forests dominated by Araucaria, Austrocedrus and Fitzroya. Among the dictyostelids isolated from the samples we collected were seven species new to science. These species (Dictyostelium austroandinum, D. chordatum, D. fasciculoideum, D. gargantuum, D. leptosomopsis, D. valdivianum and Polysphondylium patagonicum) are described herein on the basis of both morphology and molecular (SSU rDNA) data. One of the new species, D. gargantuum, is one of the largest representatives of the group reported to date. Another unusual species, D. chordatum, produces long interwoven sorocarps that do not appear to respond to a spacing gas similar to the condition first noted in D. implicatum.

  7. Microbial Life in a Fjord: Metagenomic Analysis of a Microbial Mat in Chilean Patagonia

    PubMed Central

    Ugalde, Juan A.; Gallardo, Maria J.; Belmar, Camila; Muñoz, Práxedes; Ruiz-Tagle, Nathaly; Ferrada-Fuentes, Sandra; Espinoza, Carola; Allen, Eric E.; Gallardo, Victor A.

    2013-01-01

    The current study describes the taxonomic and functional composition of metagenomic sequences obtained from a filamentous microbial mat isolated from the Comau fjord, located in the northernmost part of the Chilean Patagonia. The taxonomic composition of the microbial community showed a high proportion of members of the Gammaproteobacteria, including a high number of sequences that were recruited to the genomes of Moritella marina MP-1 and Colwelliapsycherythraea 34H, suggesting the presence of populations related to these two psychrophilic bacterial species. Functional analysis of the community indicated a high proportion of genes coding for the transport and metabolism of amino acids, as well as in energy production. Among the energy production functions, we found protein-coding genes for sulfate and nitrate reduction, both processes associated with Gammaproteobacteria-related sequences. This report provides the first examination of the taxonomic composition and genetic diversity associated with these conspicuous microbial mat communities and provides a framework for future microbial studies in the Comau fjord. PMID:24015199

  8. Malvinas-slope water intrusions on the northern Patagonia continental shelf

    NASA Astrophysics Data System (ADS)

    Piola, A. R.; Martínez Avellaneda, N.; Guerrero, R. A.; Jardón, F. P.; Palma, E. D.; Romero, S. I.

    2010-03-01

    The Patagonia continental shelf located off southeastern South America is bounded offshore by the Malvinas Current, which extends northward from northern Drake Passage (~55° S) to nearly 38° S. The transition between relatively warm-fresh shelf waters and Subantarctic Waters from the western boundary current is characterized by a thermohaline front extending nearly 2500 km. We use satellite derived sea surface temperature, and chlorophyll-a data combined with hydrographic and surface drifter data to document the intrusions of slope waters onto the continental shelf near 41° S. These intrusions create vertically coherent localized negative temperature and positive salinity anomalies extending onshore about 150 km from the shelf break. The region is associated with a center of action of the first mode of non-seasonal sea surface temperature variability and also relatively high chlorophyll-a variability, suggesting that the intrusions are important in promoting the local development of phytoplankton. The generation of slope water penetrations at this location may be triggered by the inshore excursion of the 100 m isobath, which appears to steer the Malvinas Current waters over the outer shelf.

  9. Malvinas-slope water intrusions on the northern Patagonia continental shelf

    NASA Astrophysics Data System (ADS)

    Piola, A. R.; Avellaneda, N. M.; Guerrero, R. A.; Jardón, F. P.; Palma, E. D.; Romero, S. I.

    2009-12-01

    The Patagonia continental shelf located off southeastern South America is bounded offshore by the Malvinas Current, which extends northward from northern Drake Passage (~55° S) to nearly 38° S. The transition between relatively warm-fresh shelf waters and Subantarctic Waters from the western boundary current is characterized by a thermohaline front extending nearly 2500 km. We use satellite derived sea surface temperature, and chlorophyll-a data combined with hydrographic and surface drifter data to document the intrusions of slope waters onto the continental shelf near 41° S. These intrusions create vertically coherent localized negative temperature and positive salinity anomalies extending onshore about 150 km from the shelf break. The region is associated with a center of action of the first mode of non-seasonal sea surface temperature variability and also relatively high chlorophyll-a variability, suggesting that the intrusions are important in promoting the local development of phytoplankton. The generation of slope water penetrations at this location may be triggered by the inshore excursion of the 100 m isobath, which appears to steer the Malvinas Current waters over the outer shelf.

  10. Zero methane emission bogs: extreme rhizosphere oxygenation by cushion plants in Patagonia.

    PubMed

    Fritz, Christian; Pancotto, Veronica A; Elzenga, Josephus T M; Visser, Eric J W; Grootjans, Ab P; Pol, Arjan; Iturraspe, Rodolfo; Roelofs, Jan G M; Smolders, Alfons J P

    2011-04-01

    • Vascular wetland plants may substantially increase methane emissions by producing root exudates and easily degradable litter, and by providing a low-resistance diffusion pathway via their aerenchyma. However, model studies have indicated that vascular plants can reduce methane emission when soil oxygen demand is exceeded by oxygen released from roots. Here, we tested whether these conditions occur in bogs dominated by cushion plants. • Root-methane interactions were studied by comparing methane emissions, stock and oxygen availability in depth profiles below lawns of either cushion plants or Sphagnum mosses in Patagonia. • Cushion plants, Astelia pumila and Donatia fascicularis, formed extensive root systems up to 120 cm in depth. The cold soil (< 10°C) and highly decomposed peat resulted in low microbial activity and oxygen consumption. In cushion plant lawns, high soil oxygen coincided with high root densities, but methane emissions were absent. In Sphagnum lawns, methane emissions were substantial. High methane concentrations were only found in soils without cushion plant roots. • This first methane study in Patagonian bog vegetation reveals lower emissions than expected. We conclude that cushion plants are capable of reducing methane emission on an ecosystem scale by thorough soil and methane oxidation.

  11. Trace elements deposition in the Tierra del Fuego region (south Patagonia) by using lichen transplants after the Puyehue-Cordón Caulle (north Patagonia) volcanic eruption in 2011.

    PubMed

    Conti, Marcelo Enrique; Jasan, Raquel; Finoia, Maria Grazia; Iavicoli, Ivo; Plá, Rita

    2016-04-01

    Lichen Usnea barbata transplants were tested as a biomonitor of atmospheric deposition in an apparently pristine environment that is Tierra del Fuego region (Patagonia, Argentina). The present survey is connected with the volcanic eruption that started in north Patagonia on June 4, 2011 from the Puyehue-Cordón Caulle volcano, Chile (north Patagonia, at 1700 km of distance of our sampling sites). Lichens were collected in September 2011 (one month of exposure) and September 2012 (1 year of exposure) in 27 sites covering the northern region of the province where trees are not present. The atmospheric deposition of 27 elements by using Neutron Activation Analysis (NAA) was determined in the collected samples. The first aim of the study was to evaluate the influence of the volcanic eruption on the regional atmospheric deposition comparing our results with baseline data we determined in U. barbata in 2006 in the same sites. The second aim was to test possible patterns of bioaccumulation between the two sampling campaigns after the volcanic eruption. With respect to 2006 baseline levels, we found significant higher levels for As, Ba, Co, Cr, Cs, Na, Sb and U in lichens collected after 1 month of exposure (first sampling campaign--2011). Between the two sampling campaigns (2011-2012) after the eruption, lichens reflected the natural contamination by volcanic ashes with significantly higher median levels of Br, Cr, Fe, K, Na, Sc, and Se. Results confirmed the very good aptitude of U. barbata to reflect the levels of elements in the environment at global scale and to reflect the volcanic emissions at distant places. Volcanic eruptions cause the emission in the atmosphere of elevated levels of particulate matter. In this regard, our findings demonstrate the importance to evaluate the metal composition of the particles to avoid possible health effects.

  12. Map Showing Seacliff Response to Climatic and Seismic Events, Seacliff State Beach, Santa Cruz County, California

    USGS Publications Warehouse

    Hapke, Cheryl J.; Richmond, Bruce M.; D'Iorio, Mimi M.

    2002-01-01

    INTRODUCTION The coastal cliffs along much of the central California coast are actively retreating. Large storms and periodic earthquakes are responsible for most of the documented seacliff slope failures. Long-term average erosion rates calculated for this section of coast (Moore and others, 1999) do not provide the spatial or temporal data resolution necessary to identify the processes responsible for retreat of the seacliffs, where episodic retreat threatens homes and community infrastructure. Research suggests that more erosion occurs along the California coast over a short time scale, during periods of severe storms or seismic activity, than occurs during decades of normal weather or seismic quiescence (Griggs and Scholar, 1998; Griggs, 1994; Plant and Griggs, 1990; Griggs and Johnson, 1979 and 1983; Kuhn and Shepard, 1979). This is the second map in a series of maps documenting the processes of short-term seacliff retreat through the identification of slope failure styles, spatial variability of failures, and temporal variation in retreat amounts in an area that has been identified as an erosion hotspot (Moore and others, 1999; Griggs and Savoy, 1985). This map presents seacliff failure and retreat data from Seacliff State Beach, California, which is located seven kilometers east of Santa Cruz (fig. 1) along the northern Monterey Bay coast. The data presented in this map series provide high-resolution spatial and temporal information on the location, amount, and processes of seacliff retreat in Santa Cruz, California. These data show the response of the seacliffs to both large magnitude earthquakes and severe climatic events such as El Ni?os; this information may prove useful in predicting the future response of the cliffs to events of similar magnitude. The map data can also be incorporated into Global Information System (GIS) for use by researchers and community planners. Four sets of vertical aerial photographs (Oct. 18, 1989; Jan. 27, 1998; Feb. 9, 1998

  13. Map Showing Seacliff Response to Climatic and Seismic Events, Depot Hill, Santa Cruz County, California

    USGS Publications Warehouse

    Hapke, Cheryl J.; Richmond, Bruce M.; D'Iorio, Mimi M.

    2002-01-01

    INTRODUCTION The coastal cliffs along much of the central California coast are actively retreating. Large storms and periodic earthquakes are responsible for most of the documented seacliff slope failures. Long-term average erosion rates calculated for this section of coast (Moore and others, 1999) do not provide the spatial or temporal data resolution necessary to identify the processes responsible for retreat of the seacliffs, where episodic retreat threatens homes and community infrastructure. Research suggests that more erosion occurs along the California coast over a short time scale, during periods of severe storms or seismic activity, than occurs during decades of normal weather or seismic quiescence (Griggs and Scholar, 1998; Griggs, 1994; Plant and Griggs, 1990; Griggs and Johnson, 1979 and 1983; Kuhn and Shepard, 1979). This is the first map in a series of maps documenting the processes of short-term seacliff retreat through the identification of slope failure styles, spatial variability of failures, and temporal variation in retreat amounts in an area that has been identified as an erosion hotspot (Moore and others, 1999; Griggs and Savoy, 1985). This map presents seacliff failure and retreat data from Depot Hill, California, which is located five kilometers east of Santa Cruz (fig.1) near the town of Capitola, along the northern Monterey Bay coast. The data presented in this map series provide high-resolution spatial and temporal information on the location, amount, and processes of seacliff retreat in Santa Cruz, California. These data show the response of the seacliffs to both large magnitude earthquakes and severe climatic events such as El NiOos; this information may prove useful in predicting the future response of the cliffs to events of similar magnitude. The map data can also be incorporated into Global Information System (GIS) for use by researchers and community planners. Four sets of vertical aerial photographs (Oct. 18, 1989; Jan. 27, 1998

  14. Sedimentary paleoenvironments of fossil platyrrhine localities, Miocene Pinturas Formation, Santa Cruz Province, Argentina

    USGS Publications Warehouse

    Bown, T.M.

    1990-01-01

    The Pinturas Formation is a pyroclastic and epiclastic aeolian deposit of Miocene age lying discordantly upon Jurassic rocks in the elevated Andean precordillera of northwest Santa Cruz Province, Argentina. The history of development of the Pinturas Formation was significantly affected by the gradual, though sporadic, draping of this aeolian sediment across a profound, slowly filling paleotopography. The Pinturas depositional cycle consisted of: (1) minor aeolian deposition followed by soil formation, and (2) major aeolian deposition followed by intervals of regional erosion. Fluvial action seems to have been almost wholly confined to intraformational erosion, and two significant intraformational erosional unconformities divide the Pinturas Formation into three sequences. The lower sequence is dominated by pyroclastic mudrocks upon which were formed very mature, probably mollic, paleosols; the middle sequence is composed largely of epiclastic sand occurring as barchanoid paleodunes; and the upper sequence consists of massive, poorly bedded pyroclastic mudrocks. Many Pinturas lacunae were reconstructed on the basis of locally preserved strata, and a novel method of holostrome reconstruction using relative paleosol maturities places Pinturas sedimentation in a more accurate temporal light. It also indicates: (1) that the Pinturas sediment accumulation rate increased with time; (2) that regional erosive intervals are correlated directly with major influxes of pyroclastic material; and (3) that the introduction of the Pinturas platyrrhine primates occurred in the sequence:Carlocebus carmenensis, C. intermedius andSoriacebus ameghinorum. Soriacebus adrianae. Pinturas paleosols appear to have formed under moist conditions, and both mature and immature varieties yield a host of ichnofossils. These include the burrows and nests of bees, scarabeid beetles, termites, and at least two different kinds of colonial rodents, in addition to rhizoliths and the calcified boles and

  15. Nine endangered taxa, one recovering ecosystem: Identifying common ground for recovery on Santa Cruz Island, California

    USGS Publications Warehouse

    McEachern, A. Kathryn; Wilken, Dieter H.

    2011-01-01

    It is not uncommon to have several rare and listed taxa occupying habitats in one landscape or management area where conservation amounts to defense against the possibility of further loss. It is uncommon and extremely exciting, however, to have several listed taxa occupying one island that is managed cooperatively for conservation and recovery. On Santa Cruz Island, the largest of the northern California island group in the Santa Barbara Channel, we have a golden opportunity to marry ecological knowledge and institutional "good will" in a field test of holistic rare plant conservation. Here, the last feral livestock have been removed, active weed control is underway, and management is focused on understanding and demonstrating system response to conservation management. Yet funding limitations still exist and we need to plan the most fiscally conservative and marketable approach to rare plant restoration. We still experience the tension between desirable quick results and the ecological pace of system recovery. Therefore, our research has focused on identifying fundamental constraints on species recovery at individual, demographic, habitat, and ecosystem levels, and then developing suites of actions that might be taken across taxa and landscapes. At the same time, we seek a performance middle ground that balances an institutional need for quick demonstration of hands-on positive results with a contrasting approach that allows ecosystem recovery to facilitate species recovery in the long term. We find that constraints vary across breeding systems, life-histories, and island locations. We take a hybrid approach in which we identify several actions that we can take now to enhance population size or habitat occupancy for some taxa by active restoration, while allowing others to recover at the pace of ecosystem change. We make our recommendations on the basis of data we have collected over the last decade, so that management is firmly grounded in ecological observation.

  16. Source of the 6 February 2013 Mw 8.0 Santa Cruz Islands Tsunami.

    NASA Astrophysics Data System (ADS)

    Romano, F.; Molinari, I.; Lorito, S.; Piatanesi, A.

    2014-12-01

    On February 6, 2013 a Mw8.0 interplate earthquake occurred in the Santa Cruz Islands region. The epicenter is located near a complex section of the Australia-Pacific plate boundary, where a short segment of dominantly strike-slip plate motion links the Solomon Trench to the New Hebrides Trench. In this region, the Australia plate subducts beneath the Pacific plate with a convergence rate of ~9cm/yr. This earthquake generated a tsunami that struck the city of Lata and several villages located on the Nendo island with tsunami height exceeding 11m (Fritz et al.,2014). The tsunami has been distinctly recorded by 5 DART buoys in the Pacific Ocean and by some tide-gauges at Solomon Islands, Fiji Islands, and New Caledonia. In this work we retrieve the source of the tsunami by inverting the signals recorded by both DART buoys and tide-gauges, and using an earthquake fault model that accounts for the variability of the subduction plate geometry. We compare and discuss our tsunamigenic slip model with previous coseismic slip models obtained by teleseismic data (Hayes et al.,2013) and telesismic data constrained by tsunami records (Lay et al.,2013). Our preferred tsunami source (maximum slip value of ~10m) is located southeast from the hypocenter and the slip direction is in agreement with the convergence direction that becomes progressively more oblique in the NW segment. We find a tsunami source roughly consistent to a possible source of low frequency radiation (http://www.iris.edu/spud/backprojection) and/or to the region of aseismic slip argued by Hayes et al. (2013). However, we do not find significantly tsunamigenic slip in the region of seismic high frequency radiation around the hypocenter.

  17. Evolution of Dengue Disease and Entomological Monitoring in Santa Cruz, Bolivia 2002 – 2008

    PubMed Central

    Brémond, Philippe; Roca, Yelin; Brenière, Simone Frédérique; Walter, Annie; Barja-Simon, Zaira; Fernández, Roberto Torres; Vargas, Jorge

    2015-01-01

    Background In the context of a rapid increase of dengue cases in the Americas, a monitoring system based on systematic serological control (IgM) of patients consulting for suspected dengue was developed in Bolivia at the end of the 1990s. In the most affected city of Santa Cruz, this system was complemented by an entomological surveillance program based on periodical search for immature stages of Aedes aegypti in dwelling water-holding containers. Here, we analyze these data and describe dengue patterns over 6 years (2002–2008), highlighting the spatial distribution of patients and vectors. Methodology /Principal Findings Data mining concerned six annual epidemic cycles (2002–2008), with continuous serological and clinical results and entomological data from 16 surveys, examined at the scales of 36 urban areas and four concentric areas covering the entire city. Annual incidence varied from 0.28‰ to 0.95‰; overall incidence was higher in women and adults, and dengue dynamics followed successive periods of high (January–June) and low (July–December) transmission. Lower numbers of cases from the city center to the periphery were observed, poorly related to the more homogeneous and permanent distribution of A. aegypti. "Plant pots" were a major vector source in the city center, and "Tires" and "Odds and ends" beyond the second ring of the city. Conclusions/Significance Over the years, the increasing trend of dengue cases has been highlighted as well as its widespread distribution over the entire city, but an underestimation of the number of cases is strongly suspected. Contrary to popular belief, the city center appears more affected than the periphery, and dengue is not particularly related to waste. Interestingly, the clinical diagnosis of dengue by physicians improved over the years, whatever the gender, age and residential area of suspected cases. PMID:25706631

  18. Misperceiving Bullshit as Profound Is Associated with Favorable Views of Cruz, Rubio, Trump and Conservatism.

    PubMed

    Pfattheicher, Stefan; Schindler, Simon

    2016-01-01

    The present research investigates the associations between holding favorable views of potential Democratic or Republican candidates for the US presidency 2016 and seeing profoundness in bullshit statements. In this contribution, bullshit is used as a technical term which is defined as communicative expression that lacks content, logic, or truth from the perspective of natural science. We used the Bullshit Receptivity scale (BSR) to measure seeing profoundness in bullshit statements. The BSR scale contains statements that have a correct syntactic structure and seem to be sound and meaningful on first reading but are actually vacuous. Participants (N = 196; obtained via Amazon Mechanical Turk) rated the profoundness of bullshit statements (using the BSR) and provided favorability ratings of three Democratic (Hillary Clinton, Martin O'Malley, and Bernie Sanders) and three Republican candidates for US president (Ted Cruz, Marco Rubio, and Donald Trump). Participants also completed a measure of political liberalism/conservatism. Results revealed that favorable views of all three Republican candidates were positively related to judging bullshit statements as profound. The smallest correlation was found for Donald Trump. Although we observe a positive association between bullshit and support for the three Democrat candidates, this relationship is both substantively small and statistically insignificant. The general measure of political liberalism/conservatism was also related to judging bullshit statements as profound in that individuals who were more politically conservative had a higher tendency to see profoundness in bullshit statements. Of note, these results were not due to a general tendency among conservatives to see profoundness in everything: Favorable views of Republican candidates and conservatism were not significantly related to profoundness ratings of mundane statements. In contrast, this was the case for Hillary Clinton and Martin O'Malley. Overall, small

  19. The Purisima Formation at Capitola Beach, Santa Cruz County, CA: A Deeper Examination of Pliocene Fossils

    NASA Astrophysics Data System (ADS)

    White, L. D.; Brooks, K.; Chen, R.; Chen, T.; James, T.; Gonzales, J.; Schumaker, D.; Williams, D.

    2005-12-01

    Fossil samples from the Pliocene Purisima Formation at Capitola Beach in Santa Cruz County, CA were collected in July-August 2005. The Purisima Formation composes the bulk of the cliffs exposed at Capitola Beach and a rich assemblage of well-preserved fossils occur in gray to brown sandstone and siltstone. Erosion of the cliff face averages 0.3 meter/year and fresh cliff falls in the winter and spring months of 2005 provided an excellent opportunity to resample the Capitola Beach section of the Purisima Formation previously documented by Perry (1988). Organisms were identified from information in Perry (1988) and were compared with collections at the California Academy of Sciences. The most abundant fossils found are from the phylum Mollusca, classes Bivalvia and Gastropoda. Abundant bivalve taxa are: Anadara trilineata, Clinocardium meekianum, Macoma sp., Protothaca staleyi, and Tresus pajaroanus. Also common are the gastropods, Calyptraea fastigata, Crepdiula princeps, Mitrella gausapata, Nassarius grammatus, Nassarius californianus, Natica clausa, and Olivella pedroana. Less common invertebrate fossils are from the phylum Echinodermata ( Dendraster sp., the extinct fossil sand dollar) and from the phylum Arthropoda ( Crustacea), crab fragments ( Cancer) and barnacles ( Balanus). Because numerous fossils are concentrated as fragments in shell beds, Norris (1986) and Perry (1988) believe many were redeposited as storm beds during strong current events that promoted rapid burial. In contrast, whale and other vertebrate bones are common in certain horizons and their presence may be related to the conditions that promoted phosphate mineralization, such as episodes of low sedimentation rates and prolonged exposure on the seafloor (Föllmi and Garrison, 1991). The bone beds, together with the rich infaunal and epifaunal invertebrate assemblages, represent a community of invertebrate organisms that thrived in a shallow marine sea during the Pliocene epoch, approximately

  20. Native plant recovery in study plots after fennel (Foeniculum vulgare) control on Santa Cruz Island

    USGS Publications Warehouse

    Power, Paula; Stanley, Thomas R.; Cowan, Clark; Robertson, James R.

    2014-01-01

    Santa Cruz Island is the largest of the California Channel Islands and supports a diverse and unique flora which includes 9 federally listed species. Sheep, cattle, and pigs, introduced to the island in the mid-1800s, disturbed the soil, browsed native vegetation, and facilitated the spread of exotic invasive plants. Recent removal of introduced herbivores on the island led to the release of invasive fennel (Foeniculum vulgare), which expanded to become the dominant vegetation in some areas and has impeded the recovery of some native plant communities. In 2007, Channel Islands National Park initiated a program to control fennel using triclopyr on the eastern 10% of the island. We established replicate paired plots (seeded and nonseeded) at Scorpion Anchorage and Smugglers Cove, where notably dense fennel infestations (>10% cover) occurred, to evaluate the effectiveness of native seed augmentation following fennel removal. Five years after fennel removal, vegetative cover increased as litter and bare ground cover decreased significantly (P < 0.0001) on both plot types. Vegetation cover of both native and other (nonfennel) exotic species increased at Scorpion Anchorage in both seeded and nonseeded plots. At Smugglers Cove, exotic cover decreased significantly (P = 0.0001) as native cover comprised of Eriogonum arborescensand Leptosyne gigantea increased significantly (P < 0.0001) in seeded plots only. Nonseeded plots at Smugglers Cove were dominated by exotic annual grasses, primarily Avena barbata. The data indicate that seeding with appropriate native seed is a critical step in restoration following fennel control in areas where the native seed bank is depauperate.

  1. Integrated assessment of air pollution using observations and modelling in Santa Cruz de Tenerife (Canary Islands).

    PubMed

    Baldasano, José M; Soret, Albert; Guevara, Marc; Martínez, Francesc; Gassó, Santiago

    2014-03-01

    The present study aims to analyse the atmospheric dynamics of the Santa Cruz de Tenerife region (Tenerife, Canary Islands). This area is defined by the presence of anthropogenic emissions (from a refinery, a port and road traffic) and by very specific meteorological and orographic conditions-it is a coastal area with a complex topography in which there is an interaction of regional atmospheric dynamics and a low thermal inversion layer. These factors lead to specific atmospheric pollution episodes, particularly in relation to SO2 and PM10. We applied a methodology to study these dynamics based on two complementary approaches: 1) the analysis of the observations from the air quality network stations and 2) simulation of atmospheric dynamics using the WRF-ARW/HERMESv2/CMAQ/BSC-DREAM8b and WRF-ARW/HYSPLIT modelling systems with a high spatial resolution (1×1 km(2)). The results of our study show that the refinery plume plays an important role in the maximum SO2 observed levels. The area of maximum impact of the refinery is confined to a radius of 3 km around this installation. A cluster analysis performed for the period: 1998-2011 identified six synoptic situations as predominant in the area. The episodes of air pollution by SO2 occur mainly in those with more limited dispersive conditions, such as the northeastern recirculation, the northwestern recirculation and the western advection, which represent 33.70%, 11.23% and 18.63% of the meteorological situations affecting the study area in the year 2011, respectively. In the case of particulate matter, Saharan dust intrusions result in episodes with high levels of PM10 that may exceed the daily limit value in all measurement station; these episodes occur when the synoptic situation is from the east (3.29% of the situations during the year 2011).

  2. Misperceiving Bullshit as Profound Is Associated with Favorable Views of Cruz, Rubio, Trump and Conservatism

    PubMed Central

    Pfattheicher, Stefan; Schindler, Simon

    2016-01-01

    The present research investigates the associations between holding favorable views of potential Democratic or Republican candidates for the US presidency 2016 and seeing profoundness in bullshit statements. In this contribution, bullshit is used as a technical term which is defined as communicative expression that lacks content, logic, or truth from the perspective of natural science. We used the Bullshit Receptivity scale (BSR) to measure seeing profoundness in bullshit statements. The BSR scale contains statements that have a correct syntactic structure and seem to be sound and meaningful on first reading but are actually vacuous. Participants (N = 196; obtained via Amazon Mechanical Turk) rated the profoundness of bullshit statements (using the BSR) and provided favorability ratings of three Democratic (Hillary Clinton, Martin O’Malley, and Bernie Sanders) and three Republican candidates for US president (Ted Cruz, Marco Rubio, and Donald Trump). Participants also completed a measure of political liberalism/conservatism. Results revealed that favorable views of all three Republican candidates were positively related to judging bullshit statements as profound. The smallest correlation was found for Donald Trump. Although we observe a positive association between bullshit and support for the three Democrat candidates, this relationship is both substantively small and statistically insignificant. The general measure of political liberalism/conservatism was also related to judging bullshit statements as profound in that individuals who were more politically conservative had a higher tendency to see profoundness in bullshit statements. Of note, these results were not due to a general tendency among conservatives to see profoundness in everything: Favorable views of Republican candidates and conservatism were not significantly related to profoundness ratings of mundane statements. In contrast, this was the case for Hillary Clinton and Martin O’Malley. Overall

  3. Phylogeography of the armadillo Chaetophractus villosus (Dasypodidae Xenarthra): post-glacial range expansion from Pampas to Patagonia (Argentina).

    PubMed

    Poljak, Sebastián; Confalonieri, Viviana; Fasanella, Mariana; Gabrielli, Magalí; Lizarralde, Marta Susana

    2010-04-01

    We report a phylogeographic study of Chaetophractus villosus populations in Argentina. Control Region (CR) sequences (484 bp) were obtained for 76 C. villosus from 20 locations across the species whole distribution range. Seventeen new haplotypes were identified. The highest genetic variation and the earliest fossils were found in the Pampean Region, thus appearing as the most probable area of origin of the species. A general pattern of Contiguous Range Expansion (CRE) was revealed by Nested Clade Analysis (NCA) supported by mismatch analysis and Fu's test. The Pampean Region would have been the pre-expansion area, while Patagonia would have been the main dispersal route of contiguous expansion, possibly after the Pleistocenic glaciations.

  4. Charles River

    EPA Pesticide Factsheets

    Information on the efforts of the US EPA, the Commonwealth of Massachusetts, the municipalities within the Charles River Watershed and nongovernmental organizations to improve the water quality of the Charles River.

  5. Amazon River

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mouth of the Amazon River     View ... of the world's mightiest rivers. This image of the Amazon's mouth was captured by the Multi-angle Imaging SpectroRadiometer (MISR) ... available at JPL September 8, 2000 - Mouth of the mighty Amazon River. project:  MISR ...

  6. Geochemical and isotopic characterization of mantle xenoliths from the back arc region of north Patagonia

    NASA Astrophysics Data System (ADS)

    Mundl, Andrea; Ntaflos, Theodoros; Lukás, Ackerman; Bizimis, Michael; Bjerg, Ernesto; Hauzenberger, Christoph

    2015-04-01

    Mantle xenoliths brought to the surface by alkali basalts in north Patagonia, Argentina, were studied for their geochemical and isotopic compositions. Samples were collected at four different outcrops within the North Patagonian Massif in Rio Negro Province. The studied sample suite from Comallo (COM), Puesto Diaz (PD), Cerro Chenque (CH) and Prahuaniyeu (PRA) comprises anhydrous spinel-harzburgites, spinel-dunites, as well as one PRA spinel-garnet-lherzolite. Bulk rock Al2O3 and CaO compositions of the studied samples lie within a narrow range of 0.68 to 1.31 wt. % and 0.36 to 1.25 wt. %, respectively. Al2O3 and CaO decrease with increasing MgO ranging from 44.7 to 48.0 wt. %. The single spinel-garnet lherzolite has a more fertile composition with CaO, Al2O3 and MgO of 2.78 wt. %, 2.35 wt. % and 42.2 wt. %, respectively. With the exception of the PRA region, the studied mantle xenoliths represent an overall highly depleted lithospheric mantle underneath northern Patagonia (up to 25% melt extraction). The rock forming minerals show concentrations typical for depleted peridotites with mg# that range from 0.91 to 0.92 for olivine and orthopyroxene and mg# from 0.91 to 0.95 for clinopyroxene. Variably elevated clinopyroxene trace element compositions in all studied north Patagonian mantle samples indicate reactions with a chromatographically fractionated melt after the initial melt depletion event. A percolating melt reacts with a strongly depleted mantle peridotite as it propagates through the wall rock and subsequently changes its composition. These melt-rock reactions lead to a compositionally evolving melt and variably altered mantle sections, which is strongly reflected in primitive mantle normalized clinopyroxene trace element patterns. Bulk rock and mineral compositions, on the other hand, suggest that this melt percolation event has not significantly affected major element systematics. Contrary, isotope and HSE systematics also indicate melt-rock reactions. In

  7. Detrital zircon geochronology and provenance of the Chubut Group in the northeast of Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Navarro, Edgardo L.; Astini, Ricardo A.; Belousova, Elena; Guler, M. Verónica; Gehrels, George

    2015-11-01

    The Chubut Group constitutes the most widespread sedimentary unit in NE Patagonia, characterized by variable-energy fluvial deposits. U-Pb analysis of detrital zircons from two sections of the Chubut Group constraint the age of the oldest sedimentary rocks in the northeast of the Somuncurá - Cañadón Asfalto Basin. In the Cañadón Williams area, at San Jorge section, 20 km NW of Telsen locality, dating of 56 detrital zircons from a medium to coarse sandstone indicated a maximum depositional age of 109 ± 1 Ma (n = 4). These sandstones were interpreted to represent shallow channels, associated with a lacustrine system. In the Telsen locality, a laser ablation analysis of 115 detrital zircons from a medium to coarse-grained sandstone, from fluvial channel facies, yielded a maximum depositional age of ca. 106 ± 1 Ma (n = 8). Both ages are consistent with volcanic events of the Barremian to Albian age in the central Patagonian Andes Region. Cathodoluminescence images of zircons from the San Jorge sample suggest an igneous origin, which is further supported by Th/U values above 0.5 in most of the grains. The distribution of the statistical modes of the main age populations of detrital zircons for the two samples [182, 185 and 189 Ma for Telsen sample (T2S) and 181 ± 1 Ma for San Jorge sample (SJS)] matches the age of the volcanic Marifil Formation. The rocks of the Marifil Formation of these ages are exposed NE to SE of the study area. The abundance of zircons of similar Jurassic ages (n = 52 for SJS and n = 105 for T2S) and the external morphology of the zircons in the sample SJS, implies a close proximity of the source area. Suggestion that the Marifil Formation was the main provenance source is also supported by northeast-southeasterly paleocurrents measured at the San Jorge and Telsen sections.

  8. The phylogenetic position of poroid Hymenochaetaceae (Hymenochaetales, Basidiomycota) from Patagonia, Argentina.

    PubMed

    Rajchenberg, Mario; Pildain, María Belén; Bianchinotti, María V; Barroetaveña, Carolina

    2015-01-01

    Six poroid Hymenochaetaceae from Patagonia, Argentina, were studied phylogenetically with nuc rDNA internal transcribed spacer (ITS) and partial 28S rDNA sequences, together with morphological data. Two new genera and a new species are introduced as well as two new combinations proposed. Arambarria destruens gen. et sp. nov. is proposed for a taxon fruiting on fallen or standing, dead Diostea juncea and Lomatia hirsuta and previously recorded erroneously as Inocutis jamaicensis; it is distinguished by annual, effused to effused-reflexed basidiomes forming pilei, a monomitic hyphal system, thick-walled and yellowish basidiospores (brownish chestnut in potassium hydroxide solution), lack of a granular core in the context and lack of setoid elements. Nothophellinus gen. nov. is proposed to accommodate Phellinus andinopatagonicus, the main white wood-rotting polypore of standing Nothofagus pumilio and also an important wood-decayer of other Nothofagus species from southern Argentina and Chile. It is morphologically similar to Phellopilus (type species P. nigrolimitatus) but differs by lacking setae. The new combinations Pseudoinonotus crustosus and Phellinopsis andina are proposed for Inonotus crustosus and Phellinus andinus, respectively. Phellinus livescens, which decays the sapwood of several standing Nothofagus species, is closely related to Phellinus uncisetus, a Neotropical species related to Fomitiporia; for the time being P. livescens is retained in Phellinus sensu lato. An unidentified taxon responsible for a white heart-rot in living Austrocedrus chilensis grouped with Phellinus caryophyllii and Fulvifomes inermis, but its generic affinities remain ambiguous. Transmission electron microscopy studies confirm this unidentified taxon has an imperforate parenthesome, which is typical of the Hymenochaetaceae.

  9. Litter and soil properties are not altered by invasive deer browsing in forests of NW Patagonia

    NASA Astrophysics Data System (ADS)

    Relva, María Andrea; Castán, Elisa; Mazzarino, María Julia

    2014-01-01

    It is largely accepted that large mammalian herbivores can indirectly influence ecosystem properties by changing the quantity and quality of litter inputs to soil through selective browsing on plant communities. However, idiosyncratic effects (positive, neutral and negative) have been found for different vegetation types, herbivory and soil properties. In this study we tested whether browsing by exotic deer introduced into Patagonian forests 90 years ago alters physical, chemical and biological soil properties and litter quantity and quality. As in many terrestrial ecosystems, N is the main nutrient that limits plant growth in Patagonia. Consequently, any disturbance that alters the N cycle, such as changes in the type or intensity of herbivory, is expected to affect these forest ecosystems. We compared soil and total litter from inside and outside five 7-yr old exclosures located on Isla Victoria, Parque Nacional Nahuel Huapi, Argentina. Despite introduced deer has significantly affected the composition, abundance and structure of the understory vegetation, we found no differences between browsed and unbrowsed areas in the physical (bulk density, moisture), chemical (pH, base cations, organic C and total N) and biological (potential microbial respiration and net N mineralization) soil properties. This could be attributable to the high capacity of volcanic soils to stabilize organic matter, buffering disturbance-induced changes. However, the quantity and quality (C, N and C/N ratio) of total litter were also not different between browsed and unbrowsed areas. Although non-significant differences were found between treatments in both compartments, litter and soil, most variables showed a slight trend toward higher values in unbrowsed areas. This suggests that 7 years of browsing exclusion would be not enough to detect changes induced by browsing, particularly in highly stable volcanic soils.

  10. An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina

    PubMed Central

    Apesteguía, Sebastián; Smith, Nathan D.; Juárez Valieri, Rubén; Makovicky, Peter J.

    2016-01-01

    Background Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit. Methodology/ Principal Findings A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton. Conclusions/ Significance Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa. PMID:27410683

  11. Environmental Niche Overlap between Common and Dusky Dolphins in North Patagonia, Argentina

    PubMed Central

    Svendsen, Guillermo Martín; Romero, María Alejandra; Williams, Gabriela Noemí; Gagliardini, Domingo Antonio; Crespo, Enrique Alberto; Dans, Silvana Laura; González, Raúl Alberto

    2015-01-01

    Research on the ecology of sympatric dolphins has increased worldwide in recent decades. However, many dolphin associations such as that between common dolphins (Delphinus delphis) and dusky dolphins (Lagenorhynchus obscurus) are poorly understood. The present study was conducted in the San Matías Gulf (SMG) ecosystem (North Patagonia, Argentina) where a high diet overlap among both species was found. The main objective of the present work was to explore the niche overlap of common and dusky dolphins in the habitat and temporal dimensions. The specific aims were (a) to evaluate the habitat use strategies of both species through a comparison of their group attributes (social composition, size and activity), and (b) to evaluate their habitat preferences and habitat overlap through Environmental Niche modeling considering two oceanographic seasons. To accomplish these aims, we used a historic database of opportunistic and systematic records collected from 1983 to 2011. Common and dusky dolphins exhibited similar patterns of group size (from less than 10 to more than 100 individuals), activity (both species use the area to feed, nurse, and copulate), and composition (adults, juveniles, and mothers with calves were observed for both species). Also, both species were observed travelling and feeding in mixed-species groups. Specific overlap indices were higher for common dolphins than for dusky dolphins, but all indices were low, suggesting that they are mainly segregated in the habitat dimension. In the case of common dolphins, the best habitats were located in the northwest of the gulf far from the coast. In the warm season they prefer areas with temperate sea surface and in the cold season they prefer areas with relatively high variability of sea surface temperature. Meanwhile, dusky dolphins prefer areas with steep slopes close to the coast in the southwestern sector of the gulf in both seasons. PMID:26091542

  12. Mountain frozen grounds as small amplitude thermal proxy in southern continental Patagonia

    NASA Astrophysics Data System (ADS)

    Ruiz, Sebastian; Beriain, Eneko; Izagirre, Eñaut; Bockheim, James; Pedro, Cid-Agüero

    2015-04-01

    Frozen grounds are an important element of the cryosphere, covering between a 20-25% of the global area. Frozen grounds are becoming a relevant object of research in the southern hemisphere, being most studies focused mainly on Antarctica. With the exception of seasonally frozen grounds, perennially frozen ground is found in continental South America, for example, in high altitude terrains from 4.600m a.s.l. in central Chile. However, scarce or not information regarding permafrost on Southern Patagonia has been reported. One of the aims of this study was to establish mountain permafrost existence at 1.200m in the southern limit of the Southern Patagonian Ice-Field, a geographically active area surrounded by different kinds of glaciers on fast retreat. The area of study presents several features of past cryogenic activity such as undefined polygonal grounds with a thick clast border and sandy-loam interior. A scarce vegetal cover is limited to lichen and moss communities. The analyzed soil does not represent a thermal barrier that may avoid heat wave dynamic along the ground profile. There was neither significant snow-cover during winter nor a vegetation layer enough to consider as insulation for the analyzed ground. Oscillations above 0°C were evidenced down to 1.8m depth during winter of 2014, ruling out the existence of permafrost at that lower limit. Year round thermal dynamic down to 1.8m in the ground profile is presented as one result of the monitoring. Small amplitude temperature fluctuations were registered upon monitoring. These minimal amplitudes were stable throughout several months and as such serve as an interesting proxy for recent and long-term climatic thermal fluctuation. The influence of winds coming from nearby glaciers highly affects near-surface amplitude. This interaction was studied. The present work is part of an ongoing monitoring network along South America that intends to fill the gap between tropical Andes and the Antarctic Peninsula.

  13. Environmental Niche Overlap between Common and Dusky Dolphins in North Patagonia, Argentina.

    PubMed

    Svendsen, Guillermo Martín; Romero, María Alejandra; Williams, Gabriela Noemí; Gagliardini, Domingo Antonio; Crespo, Enrique Alberto; Dans, Silvana Laura; González, Raúl Alberto

    2015-01-01

    Research on the ecology of sympatric dolphins has increased worldwide in recent decades. However, many dolphin associations such as that between common dolphins (Delphinus delphis) and dusky dolphins (Lagenorhynchus obscurus) are poorly understood. The present study was conducted in the San Matías Gulf (SMG) ecosystem (North Patagonia, Argentina) where a high diet overlap among both species was found. The main objective of the present work was to explore the niche overlap of common and dusky dolphins in the habitat and temporal dimensions. The specific aims were (a) to evaluate the habitat use strategies of both species through a comparison of their group attributes (social composition, size and activity), and (b) to evaluate their habitat preferences and habitat overlap through Environmental Niche modeling considering two oceanographic seasons. To accomplish these aims, we used a historic database of opportunistic and systematic records collected from 1983 to 2011. Common and dusky dolphins exhibited similar patterns of group size (from less than 10 to more than 100 individuals), activity (both species use the area to feed, nurse, and copulate), and composition (adults, juveniles, and mothers with calves were observed for both species). Also, both species were observed travelling and feeding in mixed-species groups. Specific overlap indices were higher for common dolphins than for dusky dolphins, but all indices were low, suggesting that they are mainly segregated in the habitat dimension. In the case of common dolphins, the best habitats were located in the northwest of the gulf far from the coast. In the warm season they prefer areas with temperate sea surface and in the cold season they prefer areas with relatively high variability of sea surface temperature. Meanwhile, dusky dolphins prefer areas with steep slopes close to the coast in the southwestern sector of the gulf in both seasons.

  14. Centennial and millennial-scale hydroclimate changes in northwestern Patagonia since 16,000 yr BP

    NASA Astrophysics Data System (ADS)

    Moreno, Patricio I.; Videla, Javiera

    2016-10-01

    We examine hydroclimate changes at centennial/millennial timescales since 16,000 yr BP in northwestern Patagonia based on the pollen and charcoal record from Lago El Salto, a small closed-basin lake located in the Chilean Lake District (41°38‧48.02″S, 73° 5‧48.42″W). We observe cold/wet conditions between 14,500-16,000 yr BP, followed by further cooling with increased precipitation until 13,000 yr BP, enhanced precipitation seasonality and/or variability between 11,600-13,000 yr BP, and an extended warm-and-dry interval between 7600 and 11,300 yr BP with peak paleofire activity. Colder-and-wetter than present conditions and muted paleofire activity prevail between 5300 and 7600 yr BP, followed by alternating cold/wet and centennial-scale warm/dry phases starting at 5300 yr BP with three conspicuous megadroughts since 2500 yr BP. The most recent megadrought occurred during the Medieval Climate Anomaly. We identify a cold reversal that spans the Antarctic Cold Reversal (ACR) and the Younger Dryas (YD) chrons with stronger-than-present westerly influence during the former and enhanced variability during the latter. These results extend the northern limit of strong cooling and increase in precipitation during the ACR and the southern limit of influence of strong hydrologic variations during the YD in terrestrial environments, suggesting an overlap in the spheres of influence of processes originating from southern and northern polar latitudes. An extended warm southern westerly wind (SWW)-minimum interval is evident between 7600 and 11,300 yr BP, followed by a rapid shift to cool-moist conditions between 5300 and 7600 yr BP brought by a mid-Holocene SWW maximum. Since then we observe centennial-scale hydroclimate variability, which has driven biodiversity and fire-regime shifts of evergreen temperate rainforests.

  15. Biomarkers of environmental stress in gills of ribbed mussel Aulacomya atra atra (Nuevo Gulf, Northern Patagonia).

    PubMed

    Giarratano, Erica; Gil, Mónica N; Malanga, Gabriela

    2014-09-01

    In this study, we assessed in gills of native ribbed mussels Aulacomya atra atra from three sites within Nuevo Gulf (Northern Patagonia) several biomarkers such as reactive oxygen species (ROS), lipid radicals (LR), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and metallothionein (MT). Furthermore, concentrations of main trace metals (Fe, Al, Zn, Cu, Cd and Pb) were quantified in mussel tissue. Results showed significant induction of SOD, GST, MT and MDA, as well as, higher concentration of Fe, Al and Cd in winter than in summer. The high MDA content measured in mussels from Folías Wreck seemed to be caused by the very high levels of Fe that would come from the corrosion of the vessel. Mussels from the control site Punta Cuevas presented the lowest levels of Cd and the highest of Al in winter. Despite positive correlations were found between Al and GST and MT, no spatial differentiation was detected in those biomarkers. On the other hand, MT was only related to Al been most likely influenced by environmental variables than by the trace metals. It has to be highlighted that the relationship detected among water temperature, nutrients and antioxidant responses in gills is probably related to the fact that this tissue is in direct contact with water and it is sensitive to its fluctuations. Taking into account that mussel gill is a tissue actively proliferating and the first target of contaminants present in water, so that changes in its antioxidant system can provide an earlier warning signal than in other tissues.

  16. Iridium, platinum and rhodium baseline concentration in lichens from Tierra del Fuego (South Patagonia, Argentina).

    PubMed

    Pino, Anna; Alimonti, Alessandro; Conti, Marcelo Enrique; Bocca, Beatrice

    2010-10-06

    Lichen samples of Usnea barbata were used as possible biomonitors of the atmospheric background level of iridium (Ir), platinum (Pt) and rhodium (Rh) in the remote region of Tierra del Fuego (South Patagonia, Argentina). Lichens were collected in 2006 at 53 sites covering 7 different areas of the region (24 transplanted lichens of the northern region and 29 native lichen samples of the central-southern region). A microwave acidic digestion procedure was used to mineralize the samples and a sector field inductively coupled plasma mass spectrometry method was developed to quantify the elements. The study of the influence of interferences on analyte signals and a quality control procedure were carried out. The analytical protocol was further applied to evaluate Ir, Pt and Rh bioaccumulation in lichens. The detection limits obtained were 0.010 ng g⁻¹, 0.013 ng g⁻¹ and 0.030 ng g⁻¹ for Ir, Pt and Rh, respectively. Recoveries at different fortification levels were between 96.3% and 106% and precision was 3.3% on average. The metals concentration (as dry weight) spanned the following ranges: Ir, <0.010-1.011 ng g⁻¹; Pt, 0.016-2.734 ng g⁻¹; and Rh, 0.063-1.298 ng g⁻¹. Data on 7 areas were similar suggesting that no specific source, for example traffic or anthropogenic activity, influenced directly the metal concentrations in Tierra del Fuego. Values detected are more likely influenced by the long-range atmospheric transport of these pollutants and, in comparison with densely populated areas in the world, they can represent the baseline for low impacted areas.

  17. Data report for seismic refraction surveys conducted from 1980 to 1982 in the Livermore Valley and the Santa Cruz Mountains, California

    USGS Publications Warehouse

    Williams, Angela J.; Brocher, Thomas M.; Mooney, Walter D.; Boken, Annette

    1999-01-01

    We provide documentation for two seismic refraction profiles acquired by the U.S. Geological Survey in the San Francisco Bay area between 1980 and 1982 in Livermore Valley and the Santa Cruz Mountains. We also include the waveforms and travel times from five aftershocks of the April 1980 Livermore earthquake that were recorded on temporary seismic stations and that have not been published. Although seismic refraction profiles from the 1980 Livermore study have been published, none of the other data for this experiment, including shot times and locations, receiver locations, data quality, and travel times, have been reported. Similarly, such data from the 1981 to 1982 seismic refraction survey in the Santa Cruz Mountains included here have not been published. The first-arrival travel times from these profiles are reported in the hope that they can be used for three-dimensional velocity models in the San Francisco Bay area, particularly for the Livermore Valley and Santa Cruz Mountains.

  18. Draft Whole-Genome Sequence of Sphingobium sp. 22B, a Polycyclic Aromatic Hydrocarbon–Degrading Bacterium from Semiarid Patagonia, Argentina

    PubMed Central

    Macchi, M.; Morelli, I. S.; Coppotelli, B. M.

    2016-01-01

    Sphingobium sp. 22B is a polycyclic aromatic hydrocarbon–degrading strain isolated from Patagonia, Argentina, with capabilities to withstand the environmental factors of that semiarid region. The draft genome shows the presence of genes related with responses to carbon starvation and drying environmental conditions. PMID:27257204

  19. Draft Whole-Genome Sequence of Sphingobium sp. 22B, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from Semiarid Patagonia, Argentina.

    PubMed

    Madueño, L; Macchi, M; Morelli, I S; Coppotelli, B M

    2016-06-02

    Sphingobium sp. 22B is a polycyclic aromatic hydrocarbon-degrading strain isolated from Patagonia, Argentina, with capabilities to withstand the environmental factors of that semiarid region. The draft genome shows the presence of genes related with responses to carbon starvation and drying environmental conditions.

  20. Hb Wilde and Hb Patagonia: two novel elongated beta-globin variants causing dominant beta-thalassemia.

    PubMed

    Scheps, Karen G; Hasenahuer, Marcia A; Parisi, Gustavo; Fornasari, María S; Pennesi, Sandra P; Erramouspe, Beatriz; Basack, Felisa N; Veber, Ernesto S; Aversa, Luis; Elena, Graciela; Varela, Viviana

    2015-06-01

    We describe here the molecular and hematological characteristics of novel frameshift mutations in exon 2 of the HBB gene (in heterozygous state) found in two Argentinean pediatric patients with dominant β-thalassemia-like features. In Hb Wilde, HBB:c.270_273delTGAG(p.Glu90Cysfs*67), we detected the deletion of the third base of the codon 89 (T) and the codon 90 (GAG), whereas in Hb Patagonia, HBB:c.296_297dupGT(p.Asp99Trpfs*59), the frameshift mutation was due to a duplication of a 'GT' dinucleotide after the second base of codon 98 (GTG). The Hb Patagonia and Hb Wilde mutations would result in elongated β-globin chains with modified C-terminal sequences and a total of 155 and 157 amino acids residues, respectively. Based on bioinformatics and structural analysis, as well as protein modeling, we predict that the elongated β-globins would affect the formation of the αβ dimers and their stability, which would further support the mechanism for the observed clinical features in both patients.

  1. Associative nitrogen fixation in nodules of the conifer Lepidothamnus fonkii (Podocarpaceae) inhabiting ombrotrophic bogs in southern Patagonia

    PubMed Central

    Borken, Werner; Horn, Marcus A.; Geimer, Stefan; Aguilar, Nelson A. Bahamonde; Knorr, Klaus-Holger

    2016-01-01

    Biological N2 fixation (BNF) in the rhizosphere of Podocarpaceae is currently attributed to unspecific diazotrophs with negligible impact on N acquisition. Here, we report specific and high associative BNF in dead cells of root nodules of Lepidothamnus fonkii distributed in ombrotrophic peatlands of Patagonia. BNF of nodulated roots, intact plants of L. fonkii and rhizospheric peat was assessed by 15N2 and acetylene reduction. Diazotrophs were identified by electron microscopy, analysis of nitrogenase encoding genes (nifH) and transcripts, and 16S rRNA. Nitrogenase encoding nifH transcripts from root nodules point to Beijerinckiaceae (Rhizobiales), known as free-living diazotrophs. Electron microscopy and 16S rRNA analysis likewise identified active Beijerinckiaceae in outer dead cells of root nodules. NifH transcripts from the rhizopshere peat revealed diverse active diazotrophs including Beijerinckiaceae. Both methods revealed high activity of nitrogenase rates in cut roots of L. fonkii (2.5 μmol N g−1 d.w. d−1 based on 15N2 assay; 2.4 μmol C2H4 g−1 d.w. d−1 based on acetylene reduction assay). The data suggest that (i) nodules recruit diazotrophic Beijerinckiaceae from peat, (ii) dead nodule cells provide an exclusive habitat for Beijerinckiaceae, and (iii) BNF in L. fonkii is one potent pathway to overcome N deficiency in ombrotrophic peatlands of Patagonia. PMID:27976730

  2. Associative nitrogen fixation in nodules of the conifer Lepidothamnus fonkii (Podocarpaceae) inhabiting ombrotrophic bogs in southern Patagonia

    NASA Astrophysics Data System (ADS)

    Borken, Werner; Horn, Marcus A.; Geimer, Stefan; Aguilar, Nelson A. Bahamonde; Knorr, Klaus-Holger

    2016-12-01

    Biological N2 fixation (BNF) in the rhizosphere of Podocarpaceae is currently attributed to unspecific diazotrophs with negligible impact on N acquisition. Here, we report specific and high associative BNF in dead cells of root nodules of Lepidothamnus fonkii distributed in ombrotrophic peatlands of Patagonia. BNF of nodulated roots, intact plants of L. fonkii and rhizospheric peat was assessed by 15N2 and acetylene reduction. Diazotrophs were identified by electron microscopy, analysis of nitrogenase encoding genes (nifH) and transcripts, and 16S rRNA. Nitrogenase encoding nifH transcripts from root nodules point to Beijerinckiaceae (Rhizobiales), known as free-living diazotrophs. Electron microscopy and 16S rRNA analysis likewise identified active Beijerinckiaceae in outer dead cells of root nodules. NifH transcripts from the rhizopshere peat revealed diverse active diazotrophs including Beijerinckiaceae. Both methods revealed high activity of nitrogenase rates in cut roots of L. fonkii (2.5 μmol N g‑1 d.w. d‑1 based on 15N2 assay; 2.4 μmol C2H4 g‑1 d.w. d‑1 based on acetylene reduction assay). The data suggest that (i) nodules recruit diazotrophic Beijerinckiaceae from peat, (ii) dead nodule cells provide an exclusive habitat for Beijerinckiaceae, and (iii) BNF in L. fonkii is one potent pathway to overcome N deficiency in ombrotrophic peatlands of Patagonia.

  3. Southern Annular Mode-like changes in southwestern Patagonia at centennial timescales over the last three millennia.

    PubMed

    Moreno, Patricio I; Vilanova, I; Villa-Martínez, R; Garreaud, R D; Rojas, M; De Pol-Holz, R

    2014-07-10

    Late twentieth-century instrumental records reveal a persistent southward shift of the Southern Westerly Winds during austral summer and autumn associated with a positive trend of the Southern Annular Mode (SAM) and contemporaneous with glacial recession, steady increases in atmospheric temperatures and CO2 concentrations at a global scale. However, despite the clear importance of the SAM in the modern/future climate, very little is known regarding its behaviour during pre-Industrial times. Here we present a stratigraphic record from Lago Cipreses (51°S), southwestern Patagonia, that reveals recurrent ~200-year long dry/warm phases over the last three millennia, which we interpret as positive SAM-like states. These correspond in timing with the Industrial revolution, the Mediaeval Climate Anomaly, the Roman and Late Bronze Age Warm Periods and alternate with cold/wet multi-centennial phases in European palaeoclimate records. We conclude that SAM-like changes at centennial timescales in southwestern Patagonia represent in-phase interhemispheric coupling of palaeoclimate over the last 3,000 years through atmospheric teleconnections.

  4. Net accumulation rates derived from ice core stable isotope records of Pío XI glacier, Southern Patagonia Icefield

    NASA Astrophysics Data System (ADS)

    Schwikowski, M.; Schläppi, M.; Santibañez, P.; Rivera, A.; Casassa, G.

    2012-12-01

    Pío XI, the largest glacier of the Southern Patagonia Icefield, reached its neoglacial maximum extent in 1994 and is one of the few glaciers in that area which is not retreating. In view of the recent warming it is important to understand glacier responses to climate changes. Due to its remoteness and the harsh conditions in Patagonia, no systematic mass balance studies have been performed. In this study we derived net accumulation rates for the period 2000 to 2006 from a 50 m (33.2 4 m weq) ice core collected in the accumulation area of Pío XI (2600 m a.s.l., 49°16´40´´ S, 73°21´14´´ W). Borehole temperatures indicate near temperate ice, but the average melt percent is only 16% ± 14%. Records of stable isotopes are well preserved and were used for identification of annual layers. Net accumulation rates range from 3.4 to 7.1 water equivalent (m weq) with an average of 5.8 m weq, comparable to precipitation amounts at the Chilean coast, but not as high as expected for the Icefield. Ice core stable isotope data correlate well with upper air temperatures and may be used as temperature proxy.

  5. The Ground-Dwelling Arthropod Community of Península Valdés in Patagonia, Argentina

    PubMed Central

    Cheli, Germán H.; Corley, J. C.; Bruzzone, O.; del Brío, M.; Martínez, F.; Román, N. Martínez; Ríos, I.

    2010-01-01

    This is the first study based on a planned and intensive sampling effort that describes the community composition and structure of the ground-dwelling arthropod assemblage of Península Valdés (Patagonia). It was carried out using pitfall traps, opened for two weeks during the summers of 2005, 2006 and 2007. A total of 28, 111 individuals were caught. Ants (Hymenoptera: Formicidae) dominated this community, followed by beetles (Coleoptera) and spiders (Araneae). The most abundant species were Pheidole bergi Mayr (Hymenoptera: Formicidae) and Blapstinus punctulatus Solier (Coleoptera: Tenebrionidae). Two new species were very recently described as new based on specimens collected during this study: Valdesiana curiosa Carpintero, Dellapé & Cheli (Hemiptera, Miridae) and Anomaloptera patagonica Dellapé & Cheli (Hemiptera, Oxycarenidae). The order Coleoptera was the most diverse taxa. The distribution of abundance data was best described by the logarithmic series model both at the family and species levels, suggesting that ecological relationships in this community could be controlled by a few factors. The community was dominated by predators from a trophic perspective. This suggests that predation acts as an important factor driving the distribution and abundances of surface-dwelling arthropods in this habitat and as such serves as a key element in understanding desert, above-ground community structure. These findings may also be useful for management and conservation purposes in arid Patagonia. PMID:20572783

  6. Liver fluke (Fasciola hepatica) naturally infecting introduced European brown hare (Lepus europaeus) in northern Patagonia: phenotype, prevalence and potential risk.

    PubMed

    Cuervo, Pablo F; Cataldo, Sophia Di; Fantozzi, M Cecilia; Deis, Erika; Isenrath, Gabriela Diaz; Viberti, Gabriela; Artigas, Patricio; Peixoto, Raquel; Valero, M Adela; Sierra, Roberto Mera Y; Mas-Coma, Santiago

    2015-09-01

    Fascioliasis has recently been included in the WHO list of Neglected Zoonotic Diseases. Besides being a major veterinary health problem, fascioliasis has large underdeveloping effects on the human communities affected. Though scarcely considered in fascioliasis epidemiology, it is well recognized that both native and introduced wildlife species may play a significant role as reservoirs of the disease. The objectives are to study the morphological characteristics of Fasciola hepatica adults and eggs in a population of Lepus europaeus, to assess liver fluke prevalence, and to analyze the potential reservoir role of the European brown hare in northern Patagonia, Argentina, where fascioliasis is endemic. Measures of F. hepatica found in L. europaeus from northern Patagonia demonstrate that the liver fluke is able to fully develop in wild hares and to shed normal eggs through their faeces. Egg shedding to the environment is close to the lower limit obtained for pigs, a domestic animal whose epidemiological importance in endemic areas has already been highlighted. The former, combined with the high prevalence found (14.28%), suggest an even more important role in the transmission cycle than previously considered. The results obtained do not only remark the extraordinary plasticity and adaptability of this trematode species to different host species, but also highlight the role of the European brown hare, and other NIS, as reservoirs capable for parasite spillback to domestic and native cycle, representing a potentially important, but hitherto neglected, cause of disease emergence.

  7. Determination of source process and the tsunami simulation of the 2013 Santa Cruz earthquake

    NASA Astrophysics Data System (ADS)

    Park, S. C.; Lee, J. W.; Park, E.; Kim, S.

    2014-12-01

    In order to understand the characteristics of large tsunamigenic earthquakes, we analyzed the earthquake source process of the 2013 Santa Cruz earthquake and simulated the following tsunami. We first estimated the fault length of about 200 km using 3-day aftershock distribution and the source duration of about 110 seconds using the duration of high-frequency energy radiation (Hara, 2007). Moment magnitude was estimated to be 8.0 using the formula of Hara (2007). From the results of 200 km of fault length and 110 seconds of source duration, we used the initial value of rupture velocity as 1.8 km/s for teleseismic waveform inversions. Teleseismic body wave inversion was carried out using the inversion package by Kikuchi and Kanamori (1991). Teleseismic P waveform data from 14 stations were used and band-pass filter of 0.005 ~ 1 Hz was applied. Our best-fit solution indicated that the earthquake occurred on the northwesterly striking (strike = 305) and shallowly dipping (dip = 13) fault plane. Focal depth was determined to be 23 km indicating shallow event. Moment magnitude of 7.8 was obtained showing somewhat smaller than the result obtained above and that of previous study (Lay et al., 2013). Large slip area was seen around the hypocenter. Using the slip distribution obtained by teleseismic waveform inversion, we calculated the surface deformations using formulas of Okada (1985) assuming as the initial change of sea water by tsunami. Then tsunami simulation was carred out using Conell Multi-grid Coupled Tsunami Model (COMCOT) code and 1 min-grid topographic data for water depth from the General Bathymetric Chart of the Ocenas (GEBCO). According to the tsunami simulation, most of tsunami waves propagated to the directions of southwest and northeast which are perpendicular to the fault strike. DART buoy data were used to verify our simulation. In the presentation, we will discuss more details on the results of source process and tsunami simulation and compare them

  8. Biotechnical performance of vegetal species in slope conservation in Cruz Alta, RS, Brazil

    NASA Astrophysics Data System (ADS)

    Prates Bisso, Fernando; Durlo, Miguel

    2016-04-01

    The aim of this work was the evaluation of biotechnical performance of different vegetal species growth in the slope soil conservation and reforest (revegetate). The study was performed with oxic soil talus, in Cruz Alta - RS, Brazil (28°23'28.14" S and 53°22'25.61" W) and began in January 2010. The sow treatments employed were: 1) cuttings of Ateleia glazioveana; 2) cuttings of Pyrostegia venusta; 3) seedlings of Baccharis trimera; 4) Seedlings of Cynodom plectostachyus; 5) blank, no sow. The evaluated parameters were: plant survival ratio (%); vegetal covered percentage; natural revegetation (plants/m2); the slope soil level reduction (cm); and water and soil runoff. C. plectostachyus and B. trimera afforded considerable higher survival (92% and 78.5%, respectively) and vegetation cover of the slope (99.6% and 82.9%) than other species. The natural revegetation showed an increase according to the ground above the slope (146.9 plants/m2) compared with the slope ramp (22.1 plants/m2). Moreover, C. plectostachyus, A. glazioveana, P. venusta, B. trimera and C. plectostachyus treatments showed 34.9, 28.6, 23.0 and 21.0 plants/m2, respectively, when compared with the blank (2.5 plants/m2) in the slope ramp region. Furthermore, the sow line regions gave 91.2 plants/m2) whereas the regions among lines afforded 8.6 plants/m2. Additionally, C. plectostachyus showed soil average drawdown profile decrease of 12.8 mm after 360 days after planting, and A. glazioveana reached 16.9 mm after 540 days according to the blank (34.0 mm). Considering the period of 60 to 360 days, it was observed significant differences in the soil loss estimative and reduction percentage compared to blank were: Blank 127.9 ton/ha/year; A. glazioveana, 117.9 ton/ha/year (-8%); P. venusta, 116.3 ton/ha/year (-9%); B. trimera, 106.7 ton/ha/year (-17%); and C. plectostachyus, 73.2 ton/ha/year (-43%). Thus, C. plectostachyus showed the best survival and vegetal coverage producing significant reduction of

  9. Hydrodynamic properties of the basal aquifer of Santa Cruz Island using seismic refraction, Galapagos - Ecuador

    NASA Astrophysics Data System (ADS)

    Loaiza, S.; Fortin, J.; Adelinet, M.; Guéguen, Y.; Violette, S.

    2012-04-01

    Santa Cruz Island is the most inhabited of the Galapagos archipelago, Ecuador. It faces important water resource problems which might lead to a major impact on their unique and pristine ecosystem, Endangered World Heritage list (2007). The scarcity of geological and hydrological data combined with the difficulty of access for field measurements lead to a poor understanding of the island hydrogeology. The Island is formed by series of thick fractured basaltic lava flows dissected by faults. The low-lying, extensive "basal" aquifer is the unique groundwater body identified on the island. This basal aquifer is subjected to sea-water intrusion, which has been mapped from electrical resistivity imaging with an airborne electromagnetic SkyTEM survey (D'Ozouville et al. 2008). In order to better understand the hydrodynamic properties of the basal aquifer, we acquired, in summer 2011, geophysical data based on seismic refraction. The experiment was conducted on three study sites located at different altitudes above the see level (Beagle site altitude +7m , Mirador +20m, and Villacis +393m). The P-wave refraction data were obtained using 24 geophones (1 component) and an acquisition system Daklink III. A hammer was used as an energy source. This source was the most environmentally friendly source that could be obtained and used in the Galapagos Island. Geophone spacing for the spreads was 1.2 or 5 m depending on the site. From our geophysical data, we could identify the different geological layers that constitute this basal aquifer and to estimate the thickness of these layers. We could as well clearly see the water level in the aquifer. More interesting, we found a P-wave velocity of ~1600 m/s in the dry fractured basalt lava flow, and a P-wave velocity of ~2700 m/s in the water saturated fractured basalt lava flow. The same velocity values were obtained in the different sites. This tends to show that the elastic properties of the aquifer are homogeneous and isotropic (at

  10. Animal-based remedies as complementary medicines in Santa Cruz do Capibaribe, Brazil

    PubMed Central

    Alves, Rômulo RN; Lima, Helenice N; Tavares, Marília C; Souto, Wedson MS; Barboza, Raynner RD; Vasconcellos, Alexandre

    2008-01-01

    Background The use of animal products in healing is an ancient and widespread cross-cultural practice. In northeastern Brazil, especially in the semi-arid region, animals and plants are widely used in traditional medicine and play significant roles in healing practices. Zootherapies form an integral part of these cultures, and information about animals is passed from generation to generation through oral folklore. Nevertheless, studies on medicinal animals are still scarce in northeastern Brazil, especially when compared to those focusing on medicinal plants. This paper examines the use and commercialization of animals for medicinal purposes in Brazil's semi-arid caatinga region. Methods Data was obtained through field surveys conducted in the public markets in the city of Santa Cruz do Capibaribe, Pernambuco State, Brazil. We interviewed 16 merchants (9 men and 7 women) who provided information regarding folk remedies based on animal products. Results A total of 37 animal species (29 families), distributed among 7 taxonomic categories were found to be used to treat 51 different ailments. The most frequently cited treatments focused on the respiratory system, and were mainly related to problems with asthma. Zootherapeutic products are prescribed as single drugs or are mixed with other ingredients. Mixtures may include several to many more valuable medicinal animals added to other larger doses of more common medicinal animals and plants. The uses of certain medicinal animals are associated with popular local beliefs known as 'simpatias'. We identified 2 medicinal species (Struthio camelus and Nasutitermes macrocephalus) not previously documented for Brazil. The use of animals as remedies in the area surveyed is associated with socio economic and cultural factors. Some of the medicinal animal species encountered in this study are included in lists of endangered species. Conclusion Our results demonstrate that a large variety of animals are used in traditional

  11. Potential for Large Transpressional Earthquakes along the Santa Cruz-Catalina Ridge, California Continental Borderland

    NASA Astrophysics Data System (ADS)

    Legg, M.; Kohler, M. D.; Weeraratne, D. S.; Castillo, C. M.

    2015-12-01

    Transpressional fault systems comprise networks of high-angle strike-slip and more gently-dipping oblique-slip faults. Large oblique-slip earthquakes may involve complex ruptures of multiple faults with both strike-slip and dip-slip. Geophysical data including high-resolution multibeam bathymetry maps, multichannel seismic reflection (MCS) profiles, and relocated seismicity catalogs enable detailed mapping of the 3-D structure of seismogenic fault systems offshore in the California Continental Borderland. Seafloor morphology along the San Clemente fault system displays numerous features associated with active strike-slip faulting including scarps, linear ridges and valleys, and offset channels. Detailed maps of the seafloor faulting have been produced along more than 400 km of the fault zone. Interpretation of fault geometry has been extended to shallow crustal depths using 2-D MCS profiles and to seismogenic depths using catalogs of relocated southern California seismicity. We examine the 3-D fault character along the transpressional Santa Cruz-Catalina Ridge (SCCR) section of the fault system to investigate the potential for large earthquakes involving multi-fault ruptures. The 1981 Santa Barbara Island (M6.0) earthquake was a right-slip event on a vertical fault zone along the northeast flank of the SCCR. Aftershock hypocenters define at least three sub-parallel high-angle fault surfaces that lie beneath a hillside valley. Mainshock rupture for this moderate earthquake appears to have been bilateral, initiating at a small discontinuity in the fault geometry (~5-km pressure ridge) near Kidney Bank. The rupture terminated to the southeast at a significant releasing step-over or bend and to the northeast within a small (~10-km) restraining bend. An aftershock cluster occurred beyond the southeast asperity along the East San Clemente fault. Active transpression is manifest by reverse-slip earthquakes located in the region adjacent to the principal displacement zone

  12. Rock-magnetic proxies of wind intensity and dust since 51,200 cal BP from lacustrine sediments of Laguna Potrok Aike, southeastern Patagonia

    NASA Astrophysics Data System (ADS)

    Lisé-Pronovost, Agathe; St-Onge, Guillaume; Gogorza, Claudia; Haberzettl, Torsten; Jouve, Guillaume; Francus, Pierre; Ohlendorf, Christian; Gebhardt, Catalina; Zolitschka, Bernd

    2015-02-01

    The sedimentary archive from Laguna Potrok Aike is the only continuous record reaching back to the last Glacial period in continental southeastern Patagonia. Located in the path of the Southern Hemisphere westerly winds and in the source region of dust deposited in Antarctica during Glacial periods, southern Patagonia is a vantage point to reconstruct past changes in aeolian activity. Here we use high-resolution rock-magnetic and physical grain size data from site 2 of the International Continental scientific Drilling Program (ICDP) Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO) in order to develop magnetic proxies of dust and wind intensity at 52°S since 51,200 cal BP. Rock-magnetic analysis indicates the magnetic mineral assemblage is dominated by detrital magnetite. Based on the estimated flux of magnetite to the lake and comparison with distal dust records from the Southern Ocean and Antarctica, kLF is interpreted as a dust indicator in the dust source of southern Patagonia at the millennial time scale, when ferrimagnetic grain size and coercivity influence are minimal. Comparison to physical grain-size data indicates that the median destructive field of isothermal remanent magnetization (MDFIRM) mostly reflects medium to coarse magnetite bearing silts typically transported by winds for short-term suspension. Comparison with wind-intensity proxies from the Southern Hemisphere during the last Glacial period and with regional records from Patagonia since the last deglaciation including marine, lacustrine and peat bog sediments as well as speleothems reveals similar variability with MDFIRM up to the centennial time scale. MDFIRM is interpreted as a wind-intensity proxy independent of moisture changes for southeastern Patagonia, with stronger winds capable of transporting coarser magnetite bearing silts to the lake.

  13. A Sedimentological Multi-Proxy Study of Late Holocene Climate Change in Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Hutchinson, E. C.; Leroy, S. L.; Dunbar, R. B.

    2014-12-01

    The southern hemisphere westerlies force and respond to circulation and heat exchange with the Southern Ocean, which in turn plays a large role in global climate change. Southern Patagonia is the only significant land mass in the path of the southern westerlies, so it is an ideal location to examine variability of this wind system and its relation to regional and global climate. Precipitation and wind strength exhibit a strong positive correlation, and we take advantage of this relationship to use a paleoclimate archive to probe past changes in the wind field. We examined a 3.6m long sediment core from Lago Sarmiento (51.06˚S, 72.91˚W) in Torres del Paine National Park, Chile, for indicators of past environmental change. Here we present a high resolution, multi-proxy record of regional paleoclimate that includes physical, biological, and chemical data sets. We measured magnetic susceptibility, weight percent organic carbon and nitrogen, δ13C of bulk sediment, and weight percent carbonate of the core. These results provide information about precipitation, relative wind strength, volcanic activity, and biological productivity in and around Lago Sarmiento over the past 4,000 years. Our age model for the core is based in part on tephrochronology. We identified three tephras, or volcanic ashes, in the core at 68-71, 110-112, and 284-286cm that are supported visually and with magnetic susceptibility measurements. Analysis of the C:N ratio of the Lago Sarmiento core demonstrates a long-term increase in the deposition of terrestrial organic matter in Lago Sarmiento over time, perhaps indicating a change from grassland to woodland due to increased precipitation. The largest excursions in the C:N ratio occur at 20, 53, 139-140, 225-226, and 252cm. The average δ13C of organic carbon is -24.81‰, and large decreases occur at 9, 45, 180, 245-246, and 252-253cm, which could indicate overturning events in the lake. The average weight percent carbonate is 18%, with large

  14. Sediment records of highly variable mercury inputs to mountain lakes in Patagonia during the past millennium

    NASA Astrophysics Data System (ADS)

    Ribeiro Guevara, S.; Meili, M.; Rizzo, A.; Daga, R.; Arribére, M.

    2010-04-01

    High Hg levels in the pristine lacustrine ecosystems of the Nahuel Huapi National Park, a protected zone situated in the Andes of Northern Patagonia, Argentina, have initiated further investigations on Hg cycling and source identification. Here we report Hg records in sedimentary sequences to identify atmospheric sources during the past millennium. In addition to global transport and deposition, a potential atmospheric Hg source to be considered is the local emissions associated with volcanic activity, because the Park is situated in the Southern Volcanic Zone. Two sediment cores were extracted from Lake Tonček, a small, high-altitude system reflecting mainly direct inputs associated with atmospheric contributions, and Lake Moreno Oeste, a much larger and deeper lake having an extended watershed covered mostly by native forest. The sedimentary sequences were dated based on both 210Pb and 137Cs profiles. In addition, tephra layers were identified and geochemically characterized for chronological application and to investigate any association of volcanic eruptions with Hg records. Hg concentrations in sediments were measured along with 32 other elements, as well as organic matter, subfossil chironomids, and biogenic silica. Observed background Hg concentrations, determined from the sequence domains with lower values, ranged from 50 to 100 ng g-1 dry weight (DW), whereas the surficial layers reached 200 to 500 ng g-1 DW. In addition to this traditional pattern, however, two deep domains in both sequences showed dramatically increased Hg levels reaching 400 to 650 ng g-1 DW; the upper dated to the 18th to 19th centuries, and the lower around the 13th century. These concentrations are not only elevated in the present profiles but also many-fold above the background values determined in other fresh water sediments, as were also the Hg fluxes, reaching 120 to 150 μg m-2 y-1 in Lake Tonček . No correlation was observed between Hg concentrations and the contents of

  15. Sediment records of highly variable mercury inputs to mountain lakes in Patagonia during the past millennium

    NASA Astrophysics Data System (ADS)

    Ribeiro Guevara, S.; Meili, M.; Rizzo, A.; Daga, R.; Arribére, M.

    2009-12-01

    High Hg levels in the pristine lacustrine ecosystems of the Nahuel Huapi National Park, a protected zone situated in the Andes of Northern Patagonia, Argentina, have initiated further investigations on Hg cycling and source identification. Here we report Hg records in sedimentary sequences aiming at identifying atmospheric sources during the past millennium. In addition to global transport and deposition, a potential atmospheric Hg source to be considered is the local emissions associated with volcanic activity, considering that the Park is situated in the Southern Volcanic Zone. Two sediment cores were extracted from Lake Tonček, a small, high-altitude system reflecting mainly direct inputs associated with atmospheric contributions, and Lake Moreno Oeste, a much larger and deeper lake having an extended watershed covered mostly by native forest. The sedimentary sequences were dated based on both 210Pb and 137Cs profiles. In addition, tephra layers were identified and geochemically characterized for chronological application and to investigate any association of volcanic eruptions with Hg records. Hg concentrations in sediments were measured along with 32 other elements, as well as organic matter, fossil chironomids, and biogenic silica. Observed background Hg concentrations, determined from the sequence domains with lower values, ranged from 50 to 100 ng g-1 DW (dry weight), whereas the surficial layers reached 200 to 500 ng g-1 DW. In addition to this traditional pattern, however, two deep domains in both sequences showed dramatically increased Hg levels reaching 400 to 650 ng g-1 DW; the upper dated to the 18th to 19th centuries, and the lower around the 13th century. These concentrations are not only elevated in the present profiles but also many-fold above the background values determined in other fresh water sediments, as were also the Hg fluxes, reaching 120 to 150 μg m-2 y-1 in Lake Tonček. No correlation was observed between Hg concentrations and the

  16. Novel aromatic ring-hydroxylating dioxygenase genes from coastal marine sediments of Patagonia

    PubMed Central

    Lozada, Mariana; Riva Mercadal, Juan P; Guerrero, Leandro D; Di Marzio, Walter D; Ferrero, Marcela A; Dionisi, Hebe M

    2008-01-01

    Background Polycyclic aromatic hydrocarbons (PAHs), widespread pollutants in the marine environment, can produce adverse effects in marine organisms and can be transferred to humans through seafood. Our knowledge of PAH-degrading bacterial populations in the marine environment is still very limited, and mainly originates from studies of cultured bacteria. In this work, genes coding catabolic enzymes from PAH-biodegradation pathways were characterized in coastal sediments of Patagonia with different levels of PAH contamination. Results Genes encoding for the catalytic alpha subunit of aromatic ring-hydroxylating dioxygenases (ARHDs) were amplified from intertidal sediment samples using two different primer sets. Products were cloned and screened by restriction fragment length polymorphism analysis. Clones representing each restriction pattern were selected in each library for sequencing. A total of 500 clones were screened in 9 gene libraries, and 193 clones were sequenced. Libraries contained one to five different ARHD gene types, and this number was correlated with the number of PAHs found in the samples above the quantification limit (r = 0.834, p < 0.05). Overall, eight different ARHD gene types were detected in the sediments. In five of them, their deduced amino acid sequences formed deeply rooted branches with previously described ARHD peptide sequences, exhibiting less than 70% identity to them. They contain consensus sequences of the Rieske type [2Fe-2S] cluster binding site, suggesting that these gene fragments encode for ARHDs. On the other hand, three gene types were closely related to previously described ARHDs: archetypical nahAc-like genes, phnAc-like genes as identified in Alcaligenes faecalis AFK2, and phnA1-like genes from marine PAH-degraders from the genus Cycloclasticus. Conclusion These results show the presence of hitherto unidentified ARHD genes in this sub-Antarctic marine environment exposed to anthropogenic contamination. This information

  17. A new peat bog testate amoeba transfer function and quantitative palaeohydrological reconstructions from southern Patagonia

    NASA Astrophysics Data System (ADS)

    van Bellen, S.; Mauquoy, D.; Payne, R.; Roland, T. P.; Hughes, P. D.; Daley, T. J.; Street-Perrot, F. A.; Loader, N.

    2013-12-01

    Testate amoebae have been used extensively as proxies for environmental change and palaeoclimate reconstructions in European and North American peatlands. The presence of these micro-organisms in surface samples is generally significantly linked to the local water table depth (WTD) and preservation of the amoeba shells downcore allows for millennial length water table reconstructions. Peat bog archive records in southern Patagonia are increasingly the focus of palaeoecological research due to the possibility of detecting changes in the Southern Westerlies. These Sphagnum magellanicum-dominated peat bogs are characterised by a wide range of water table depths, from wet hollows to high hummocks (>100 cm above the water table). Here we present the first transfer function for this region along with ~2k-year palaeorecords from local peat bogs. A modern dataset (155 samples) was sampled along transects from five bogs in 2012 and 2013. Measurements of WTD, pH and conductivity were taken for all samples. The transfer function model was based on the 2012 dataset, while the 2013 samples served as an independent test set to validate the model. Besides the standard leave-one-out cross-validation, we applied leave-one-site-out and leave-one transect-out cross-validation, which are effective means of verifying the degree of clustering in the dataset. To ensure that the environmental gradient had been evenly sampled we quantified the root-mean-squared error of prediction (RMSEP) individually for segments of this gradient. Ordinations showed a clear hydrological gradient in amoeba assemblages, with the dominant Assulina muscorum at the dry end and Amphitrema wrightianum and Difflugia globulosa at the wet end. Canonical correspondence analysis showed that WTD was the most important environmental variable, accounting for 18% of the variance in amoeba assemblages. A weighted averaging-partial least squares model showed best performance in cross-validation, using the 2013 data as an

  18. Ice elevation and areal changes of glaciers from the Northern Patagonia Icefield, Chile

    NASA Astrophysics Data System (ADS)

    Rivera, Andrés; Benham, Toby; Casassa, Gino; Bamber, Jonathan; Dowdeswell, Julian A.

    2007-10-01

    High thinning rates (up to - 4.0 ± 0.97 m a - 1 ) have been measured at Campo de Hielo Patagónico Norte (CHN) or Northern Patagonia Icefield, Chile between 1975 and 2001. Results have been obtained by comparing a Digital Elevation Model (DEM) derived from regular cartography compiled by Instituto Geográfico Militar of Chile (IGM) based upon 1974/1975 aerial photographs and a DEM generated from Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) satellite images acquired in September 2001. A complete cloud-free Landsat ETM+ satellite image mosaic acquired in March 2001 was used to update the available glacier inventory of the CHN, including all glaciers larger than 0.5 km 2 (48 new glaciers). A new delineation of ice divides was also performed over the accumulation areas of glaciers sharing the high plateau where the existing regular cartography exhibits poor coverage of topographic information. This updated glacier inventory produced a total ice area for 2001 of 3953 km 2, which represents a decrease of 3.4 ± 1.5% (140 ± 61 km 2 of ice) with respect to the total ice area of the CHN in 1979 calculated from a Landsat MSS satellite image. Almost 62% of the total area change between 1979 and 2001 took place in glaciers located at the western margin of the CHN, where the maximum area loss was experienced by Glaciar San Quintín with 33 km 2. At the southern margin, Glaciar Steffen underwent the largest ice-area loss (12 km 2 or 2.6% of the 1979 area), whilst at the eastern margin the greatest area loss took place in Glaciares Nef (7.9 km 2, 5.7% of the 1979 area) and Colonia (9.1 km 2, 2.7% of the 1979 area). At the northern margin of the CHN the lower debris-covered ablation area of Glaciar Grosse collapsed into a new freshwater lake formed during the late 1990s. The areal changes measured at the CHN are much larger than previously estimated due to the inclusion of changes experienced in the accumulation areas. The CHN as a whole is

  19. The Solomon Islands Tsunami of 6 February 2013 in the Santa Cruz Islands: Field Survey and Modeling

    NASA Astrophysics Data System (ADS)

    Fritz, Hermann M.; Papantoniou, Antonios; Biukoto, Litea; Albert, Gilly; Wei, Yong

    2014-05-01

    On February 6, 2013 at 01:12:27 UTC (local time: UTC+11), a magnitude Mw 8.0 earthquake occurred 70 km to the west of Ndendo Island (Santa Cruz Island) in the Solomon Islands. The under-thrusting earthquake near a 90° bend, where the Australian plate subducts beneath the Pacific plate generated a locally focused tsunami in the Coral Sea and the South Pacific Ocean. The tsunami claimed the lives of 10 people and injured 15, destroyed 588 houses and partially damaged 478 houses, affecting 4,509 people in 1,066 households corresponding to an estimated 37% of the population of Santa Cruz Island. A multi-disciplinary international tsunami survey team (ITST) was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment and coral boulder depositions, land level changes, damage patterns at various scales, performance of the man-made infrastructure and impact on the natural environment. The 19 to 23 February 2013 ITST covered 30 locations on 4 Islands: Ndendo (Santa Cruz), Tomotu Noi (Lord Howe), Nea Tomotu (Trevanion, Malo) and Tinakula. The reconnaissance completely circling Ndendo and Tinakula logged 240 km by small boat and additionally covered 20 km of Ndendo's hard hit western coastline by vehicle. The collected survey data includes more than 80 tsunami runup and flow depth measurements. The tsunami impact peaked at Manoputi on Ndendo's densely populated west coast with maximum tsunami height exceeding 11 m and local flow depths above ground exceeding 7 m. A fast tide-like positive amplitude of 1 m was recorded at Lata wharf inside Graciosa Bay on Ndendo Island and misleadingly reported in the media as representative tsunami height. The stark contrast between the field observations on exposed coastlines and the Lata tide gauge recording highlights the importance of rapid tsunami reconnaissance surveys. Inundation distance and damage more than 500 m inland were recorded at Lata airport on Ndendo Island. Landslides were

  20. A Combined Observational and Modeling Approach to Study Modern Dust Transport from the Patagonia Desert to East Antarctica

    NASA Technical Reports Server (NTRS)

    Gasso, S.; Stein, A.; Marino, F.; Castellano, E.; Udisti, R.; Ceratto, J.

    2010-01-01

    The understanding of present atmospheric transport processes from Southern Hemisphere (SH) landmasses to Antarctica can improve the interpretation of stratigraphic data in Antarctic ice cores. In addition, long range transport can deliver key nutrients normally not available to marine ecosystems in the Southern Ocean and may trigger or enhance primary productivity. However, there is a dearth of observational based studies of dust transport in the SH. This work aims to improve current understanding of dust transport in the SH by showing a characterization of two dust events originating in the Patagonia desert (south end of South America). The approach is based on a combined and complementary use of satellite retrievals (detectors MISR, MODIS, GLAS ,POLDER, OMI,), transport model simulation (HYSPLIT) and surface observations near the sources and aerosol measurements in Antarctica (Neumayer and Concordia sites). Satellite imagery and visibility observations confirm dust emission in a stretch of dry lakes along the coast of the Tierra del Fuego (TdF) island (approx.54deg S) and from the shores of the Colihue Huapi lake in Central Patagonia (approx.46deg S) in February 2005. Model simulations initialized by these observations reproduce the timing of an observed increase in dust concentration at the Concordia Station and some of the observed increases in atmospheric aerosol absorption (here used as a dust proxy) in the Neumayer station. The TdF sources were the largest contributors of dust at both sites. The transit times from TdF to the Neumayer and Concordia sites are 6-7 and 9-10 days respectively. Lidar observations and model outputs coincide in placing most of the dust cloud in the boundary layer and suggest significant de- position over the ocean immediately downwind. Boundary layer dust was detected as far as 1800 km from the source and approx.800 km north of the South Georgia Island over the central sub-Antarctic Atlantic Ocean. Although the analysis suggests the

  1. Hydrogeologic investigations of the Miocene Nogales Formation in the Nogales Area, Upper Santa Cruz Basin, Arizona

    USGS Publications Warehouse

    Page, William R.; Gray, Floyd; Bultman, Mark W.; Menges, Christopher M.

    2016-07-28

    and mixed-layer clay. X-ray diffraction analyses verified clinoptilolite as the only zeolite in Nogales Formation samples; they also verified the presence of smectite and illite clay and some kaolinite. Samples which contain greater amounts of clinoptilolite and lesser amounts of smectite have high porosity and SHC in narrow ranges. However, samples with abundant smectite and lesser amounts of clinoptilolite span the entire ranges of porosity and SHC for the formation.All members of the Nogales Formation are fractured and faulted as a result of Tertiary Basin and Range extensional deformation, which was broadly contemporaneous with deposition of the formation. These structures may have significant influence on groundwater flow in the upper Santa Cruz basin because, although many of the sediments in the formation have characteristics indicating they may be productive aquifers based only on porous-media flow, fracturing in these sediments may further enhance permeability and groundwater flow in these basin-fill aquifers by orders of magnitude.

  2. Digital Compilation of "Preliminary Map of Landslide Deposits in Santa Cruz County, California, By Cooper-Clark and Associates, 1975": A Digital Map Database

    USGS Publications Warehouse

    Report by Roberts, Sebastian; Barron, Andrew D.; Preface by Brabb, Earl E.; Pike, Richard J.

    1998-01-01

    A 1:62,500-scale black-and-white map identifying some 2,000 landslides of various types in Santa Cruz County, California, has been converted to a digital-map database that can be acquired from the U.S. Geological Survey over the Internet or on magnetic tape.

  3. [List of the type species of Ceratopogonidae (Diptera, Nematocera) deposited in the Entomological Collection of Instituto Oswaldo Cruz, Rio de Janeiro, Brazil].

    PubMed

    Felippe-Bauer, M; Oliveira Sd, S

    2001-11-01

    A list of all type specimens of the Family Ceratopogonidae, present in the Entomological Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil is presented. This list includes the genera Bahiahelea, Culicoides, Dasyhelea, Downeshelea, Forcipomyia, Leptoconops, Mallochohelea, Monohelea, Neobezzia, Palpomyia and Sphaerohelea.

  4. Field Surveys of Rare Plants on Santa Cruz Island, California, 2003-2006: Historical Records and Current Distributions

    USGS Publications Warehouse

    McEachern, A. Kathryn; Chess, Katherine A.; Niessen, Ken

    2010-01-01

    Santa Cruz Island is the largest of the northern Channel Islands located off the coast of California. It is owned and managed as a conservation reserve by The Nature Conservancy and the Channel Islands National Park. The island is home to nine plant taxa listed in 1997 as threatened or endangered under the federal Endangered Species Act, because of declines related to nearly 150 years of ranching on the island. Feral livestock were removed from the island as a major conservation step, which was part of a program completed in early 2007 with the eradication of pigs and turkeys. For the first time in more than a century, the rare plants of Santa Cruz Island have a chance to recover in the wild. This study provides survey information and living plant materials needed for recovery management of the listed taxa. We developed a database containing information about historical collections of the nine taxa and used it to plan a survey strategy. Our objectives were to relocate as many of the previously known populations as possible, with emphasis on documenting sites not visited in several decades, sites that were poorly documented in the historical record, and sites spanning the range of environmental conditions inhabited by the taxa. From 2003 through 2006, we searched for and found 39 populations of the taxa, indicating that nearly 80 percent of the populations known earlier in the 1900s still existed. Most populations are small and isolated, occupying native-dominated habitat patches in a highly fragmented and invaded landscape; they are still at risk of declining through population losses. Most are not expanding beyond the edges of their habitat patches. However, most taxa appeared to have good seed production and a range of size classes in populations, indicating a good capacity for plant recruitment and population growth in these restricted sites. For these taxa, seed collection and outplanting might be a good strategy to increase numbers of populations for species

  5. The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California

    SciTech Connect

    Maher, K.; Steefel, C. I.; White, A.F.; Stonestrom, D.A.

    2009-02-25

    In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka marine terrace chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized (White et al., 2008, GCA) and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisser and [2006] or the aluminum inhibition model proposed by Oelkers et al. [1994], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Observed maximum clay abundances in the argillic horizons occur at the depth and time where the reaction fronts of the primary minerals overlap. The modeling indicates that the argillic horizon at Santa Cruz can be explained almost entirely by weathering of primary minerals and in situ clay precipitation accompanied by undersaturation of kaolinite at the top of the profile. The rate constant for kaolinite precipitation was also determined based on model simulations of mineral abundances and dissolved Al, SiO{sub 2}(aq) and pH in pore waters. Changes in the rate of kaolinite precipitation or the flow rate do not affect the gradient of the primary mineral weathering profiles, but instead control the rate of propagation of the primary mineral weathering fronts and thus total

  6. River restoration

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen; Angermeier, Paul L.; Bledsoe, Brian; Kondolf, G. Mathias; Macdonnell, Larry; Merritt, David M.; Palmer, Margaret A.; Poff, N. Leroy; Tarboton, David

    2005-10-01

    River restoration is at the forefront of applied hydrologic science. However, many river restoration projects are conducted with minimal scientific context. We propose two themes around which a research agenda to advance the scientific basis for river restoration can be built. First, because natural variability is an inherent feature of all river systems, we hypothesize that restoration of process is more likely to succeed than restoration aimed at a fixed end point. Second, because physical, chemical, and biological processes are interconnected in complex ways across watersheds and across timescales, we hypothesize that restoration projects are more likely to be successful in achieving goals if undertaken in the context of entire watersheds. To achieve restoration objectives, the science of river restoration must include (1) an explicit recognition of the known complexities and uncertainties, (2) continued development of a theoretical framework that enables us to identify generalities among river systems and to ask relevant questions, (3) enhancing the science and use of restoration monitoring by measuring the most effective set of variables at the correct scales of measurement, (4) linking science and implementation, and (5) developing methods of restoration that are effective within existing constraints. Key limitations to river restoration include a lack of scientific knowledge of watershed-scale process dynamics, institutional structures that are poorly suited to large-scale adaptive management, and a lack of political support to reestablish delivery of the ecosystem amenities lost through river degradation. This paper outlines an approach for addressing these shortcomings.

  7. Mississippi River

    Atmospheric Science Data Center

    2014-05-15

    article title:  Mississippi River Flooding during Spring 2001   ... 794 x 390 South TIFF: 1024 x 724 The Mississippi River, from its source at Lake Itasca Minnesota to the Gulf of ... lower valley occurred in 1927 and the largest in the upper Mississippi in 1993. In April 2001 another flooding event in the upper ...

  8. Results of chemical and stable isotopic analyses of water samples collected in the Patagonia Mountains, southern Arizona

    USGS Publications Warehouse

    Wanty, Richard B.; Shanks, Wayne C.; Lamothe, Paul; Meier, A.L.; Lichte, Fred; Briggs, Paul H.; Berger, Byron R.

    2001-01-01

    Water samples were collected in the Patagonia Mountains in February, 1997. Most of the samples were collected from portals of abandoned mines, or from stream drainages immediately downstream from abandoned mines. Most of the samples have low pH ( 1000 mg/L). Anion composition of the water samples is dominated by sulfate, while cation compositions range from calcium-dominated to mixed calcium-magnesium or calcium-sodium-dominated waters. Metals such as iron, manganese, copper, zinc, and aluminum contribute a significant portion (>10%) of the cation content to the water samples. Because of the low pH?s, protons contribute up to several percent of the cation character of the waters in some of the samples. The data are presented in tabular and graphical formats, with descriptions of data quality and brief descriptions of results.

  9. A new species of Ascocotyle (Trematoda: Heterophyidae) from the South American sea lion, Otaria flavescens, off Patagonia, Argentina.

    PubMed

    Hernández-Orts, Jesús Servando; Montero, Francisco Esteban; Crespo, Enrique Alberto; García, Néstor Aníbal; Raga, Juan Antonio; Aznar, Francisco Javier

    2012-08-01

    We describe a new heterophyid species, Ascocotyle (Ascocotyle) patagoniensis n. sp., based on specimens collected from the intestines of the South American sea lion Otaria flavescens from Patagonia (Argentina). Ascocotyle (A.) patagoniensis n. sp. is distinguished from the other species of the subgenus by the number of circumoral spines, which are arranged in 2 rows of 18 to 23. The new species also differs from the other species in having a gonotyl without papillae. The specimens exhibited the widest seminal receptacle described for a species of this subgenus. Species of the subgenus Ascocotyle usually infect fish-eating birds or mammals in freshwater or brackish habitats. Ascocotyle (A.) patagoniensis n. sp. is the first species of the subgenus described from a marine mammal. However, no metacercariae of Ascocotyle spp. were found in 542 marine teleosts from 20 species collected in the same locality. The life cycle of the marine species from the Ascocotyle -complex infecting pinnipeds remains elusive.

  10. Using glacial morphology to constrain the impact of the Chile active spreading ridge subduction in Central Patagonia

    NASA Astrophysics Data System (ADS)

    Scalabrino, B.; Ritz, J. F.; Lagabrielle, Y.

    2009-04-01

    The Central Patagonian Cordillera is a unique laboratory to study interaction between oceanic and continental lithospheres during the subduction of an active spreading ridge beneath a continent. The subduction of the South Chile spreading Ridge, which separates the Nazca plate from the Antarctic plate, started ca. 15-14 Ma at the southern tip of Patagonia (55°S latitude). The northwards migration of the Chile Triple Junction induces the subduction of several segments especially around 46°S latitude. There, three segments subducted at ca. 6, 3 and 0.3 Ma, leading to the formation of a large asthenospheric slab-window beneath Central Patagonia. Contemporaneously, the Central Patagonia reliefs are undergoing major glacial events since at least 7 Ma. These events are evidenced to the east of the Central Patagonian morphotectonic front within perched relict surfaces. Inset in these perched glacial surfaces are found mid-Pleistocene glacial valleys, as the Lake General Carrera-Buenos Aires amphitheatre (LGCBA), which formed between 1.1 Ma and 16 ka. We used the relationships between the glacial valleys and the volcanism associated with the asthenospheric slab-window to better constraints the structural evolution of the Patagonian Cordillera related to the subduction of the Chili active spreading Ridge. The present work focused within two well-preserved perched flat surfaces named Meseta del Lago Buenos Aires and Meseta del Cerro Galera: (i) The meseta del Lago Buenos Aires defines a plateau made of interbedded units of tills and lavas dated between 12 Ma and 3 Ma. The top surface of the meseta, ˜2000 meters high is dated at 3 Ma, and is shaped by four NE-SW trending glacial lobes characterized with kettles, lineations and moraines. The glacial valleys are beheaded westwards and define perched valleys 200 to 400 meters higher than the western Cordillera. This suggests recent vertical movement along N160 extensive/transtensive corridor located between the morphotectonic

  11. High-resolution paleomagnetic records from Laguna Potrok Aike (Patagonia, Argentina) for the last 16,000 years

    NASA Astrophysics Data System (ADS)

    Gogorza, Claudia S. G.; Irurzun, MaríA. A.; Sinito, Ana M.; Lisé-Pronovost, Agathe; St-Onge, Guillaume; Haberzettl, Torsten; Ohlendorf, Christian; Kastner, Stephanie; Zolitschka, Bernd

    2012-02-01

    Holocene and Late-glacial records documenting variations in direction and intensity of the geomagnetic field during the last 16,000 cal. BP are presented for Southern Patagonia. This continuous high-resolution terrestrial record from Laguna Potrok Aike (51°58'S, 70°23'W) was recovered within the SALSA (South Argentinean Lake Sediment Archives and modeling) project. Mineral magnetic measurements indicate that pseudo single-domain magnetite is the major carrier of the remanence allowing the reliable determination of stable natural remanent magnetization inclinations and declinations from alternating field demagnetization and principal component analysis. Paleomagnetic secular variation records reveal most of the familiar features of declination and inclination that have previously been reported in other records from South Argentina but conspicuous centennial-scale differences are also observed. The results illustrate the potential of paleosecular variations records for dating sedimentary sequences in southern South America.

  12. Revision of Plumarius Philippi 1873 (Hymenoptera: Chrysidoidea, Plumariidae) from Argentina north of Patagonia, with description of eighteen new species.

    PubMed

    Diez, Patricia A; Roig-Alsina, Arturo

    2016-04-07

    Twenty six species of Plumarius from Argentina north of Patagonia are revised. Eighteen new species: Plumarius politus sp. nov., P. sarophorus sp. nov., P. globulosus sp. nov., P. angulatus sp. nov., P. noa sp. nov., P. divergens sp. nov., P. malaris sp. nov., P. gracilior sp. nov., P. riojanus sp. nov., P. exophthalmus sp. nov., P. planatus sp. nov., P. albinervis sp. nov., P. truncatus sp. nov., P. mikrommatus sp. nov., P. obscurus sp. nov., P. gracilis sp. nov., P. fidalgoi sp. nov., and P. ocellulatus sp. nov. are described and illustrated. A new record for known species as well as a key to 26 known species in the region is given. A redescription of P. tumidulus Papp, 2000, which is the first record of the family Plumariidae from Uruguay, is done.

  13. Epidemiological studies on intestinal helminth parasites of the patagonian grey fox (Pseudalopex griseus) in Tierra del Fuego, Patagonia Argentina.

    PubMed

    Zanini, Fabián; Laferrara, Miguel; Bitsch, Matías; Pérez, Héctor; Elissondo, Maria Celina

    2006-03-31

    The present work was performed to study the intestinal helminths of the patagonian grey fox (Pseudalopex griseus) and to obtain information about its possible role in the sylvatic life cycle of Echinococcu granulosus in Tierra del Fuego, Patagonia Argentina. Eighty-one foxes were captured and subject to post-mortem analysis. Thirty-one foxes (38.3%) harboured helminths. A total of six helminth species were recovered. Only one adult of E. granulosus was found in the studied samples. The current study is the first report of the intestinal helminths of the patagonian grey fox in Tierra del Fuego, Argentina and showed that this specie is probably not an important reservoir host for E. granulosus.

  14. Horticultural and gathering practices complement each other: a case study in a rural population of Northwestern Patagonia.

    PubMed

    Eyssartier, Cecilia; Ladio, Ana H; Lozada, Mariana

    2011-01-01

    We investigated gathering and cultivating practices and how they complement each other in a rural population of Northwestern Patagonia. We analyzed plant diversity, species similarity, biogeographic origin, and plant use by means of semi-structured interviews and field visits. Pichi Leufu inhabitants used 173 species: 138 cultivated plants, mainly for edible purposes, and 45 wild species principally for medicinal use. Most cultivated species were exotic (91.3%), whereas gathered plants were both native and exotic. While locals maintained vegetable gardens, the adoption of greenhouses improved conditions for certain crops. The integration of novel practices with ancestral knowledge suggests resilient processes in this community, probably reflected in the dynamics of current horticultural and gathering practices, which complement each other.

  15. [The creation of the first anesthesiology service in Spain (Hospital de la Santa Cruz y San Pablo, Barcelona 1941)].

    PubMed

    Unzueta, M C; Hervás, C; Villar Landeira, J M

    2002-03-01

    On the sixtieth anniversary of the founding of the first Spanish anesthesia department, we review factors that led to its creation and its early development. Hospital de la Santa Cruz y San Pablo in Barcelona was the place where the service was established for several reasons. The first was the growing need for anesthesia to be administered by specialized physicians able to handle problems developing during and after surgery. The second was the presence of a prestigious surgeon, Dr. Juan Soler Juliá, who perceived the need, alongside the only physician in Spain who was completely dedicated to anesthesiology, Dr. José Miguel Martínez. Finally, the fact that professional anesthesiology allowed a physician to earn a decent income triggered interest in the specialty among physicians.

  16. Nearshore disposal of fine-grained sediment in a high-energy environment: Santa Cruz Harbor case study

    USGS Publications Warehouse

    Cronin, Katherine; van Ormondt, Maarten; Storlazzi, Curt D.; Presto, Katherine; Tonnon, Pieter K.; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

    2011-01-01

    Current regulations in California prohibit the disposal of more than 20% fine-grained sediment in the coastal zone; this threshold is currently being investigated to determine if this environmental regulation can be improved upon. A field monitoring and numerical modeling experiment took place late 2 009 to determine the fate of fine-grained dredge disposal material from Santa Cruz Harbor, California, U.S.A. A multi-nested, hydrodynamic-sediment transport modeling approach was used to simulate the direction and dispersal of the dredge plume. Result s show that the direction and dispersal of the plume was influenced by the wave  climate, a large proportion of which moved in a easterly direction during wave events. Therefore it is vitally important to accurately simulate the tides, waves, currents, temperature and salinity when modeling the dispersal of the fine-grained dredge plume. 

  17. Maps showing ground-water conditions in the lower Santa Cruz area, Pinal, Pima, and Maricopa Counties, Arizona, 1977

    USGS Publications Warehouse

    Konieczki, A.D.; English, C.S.

    1979-01-01

    The lower Santa Cruz area includes about 5,400 square miles in south-central Arizona and is the second largest agricultural area in the State. The area depends mainly on ground water for irrigation, and in 1976 about 966,000 acre-feet of ground water was pumped from the area. As a result of the large-scale long-term withdrawal of ground water, water levels have declined , and the direction of ground-water flow has changed. Since 1923 , declines of nearly 500 feet have occurred near Stanfield. Information shown on the maps (scale 1:125,000) includes depth to water, altitude of the water level, specific conductance, fluoride concentration, change in water level (1923-77), and land use. Hydrographs of the water level in selected wells and a table of historical pumpage also are included. (Woodard-USGS)

  18. The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California

    USGS Publications Warehouse

    Maher, K.; Steefel, Carl; White, A.F.; Stonestrom, D.A.

    2009-01-01

    In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation, and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka Marine Terrace Chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized [White A. F., Schulz M. S., Vivit D. V., Blum A., Stonestrom D. A. and Anderson S. P. (2008) Chemical weathering of a Marine Terrace Chronosequence, Santa Cruz, California. I: interpreting the long-term controls on chemical weathering based on spatial and temporal element and mineral distributions. Geochim. Cosmochim. Acta 72 (1), 36-68] and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisserand [Hellmann R. and Tisserand D. (2006) Dissolution kinetics as a function of the Gibbs free energy of reaction: An experimental study based on albite feldspar. Geochim. Cosmochim. Acta 70 (2), 364-383] or the aluminum inhibition model proposed by Oelkers et al. [Oelkers E. H., Schott J. and Devidal J. L. (1994) The effect of aluminum, pH, and chemical affinity on the rates of aluminosilicate dissolution reactions. Geochim. Cosmochim. Acta 58 (9), 2011-2024], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Additionally, observed maximum clay abundances in the argillic horizons occur at

  19. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae) from Cerro Fatal on Santa Cruz Island

    PubMed Central

    Chiari, Ylenia; Garrick, Ryan C.; Russello, Michael A.; Benavides, Edgar; Watkins-Colwell, Gregory J.; Glaberman, Scott; Tapia, Washington; Gibbs, James P.; Cayot, Linda J.; Caccone, Adalgisa

    2015-01-01

    The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises. PMID:26488886

  20. Field-trip guide to the southeastern foothills of the Santa Cruz Mountains in Santa Clara County, California

    USGS Publications Warehouse

    Stoffer, Philip W.; Messina, Paula

    2002-01-01

    This field trip is an introduction to the geology of the southeastern foothills of the Santa Cruz Mountains in southern Santa Clara County. Seven stops include four short hikes to access rock exposures and views of the foothills east of Loma Prieta Peak between Gilroy and San José. Field-trip destinations highlight the dominant rock types of the "Franciscan assemblage" including outcrops of serpentinite, basalt, limestone, ribbon chert, graywacke sandstone, and shale. General discussions include how the rocks formed, and how tectonism and stream erosion have changed the landscape through time. All field trip stops are on public land; most are near reservoir dams of the Santa Clara Valley Water District. In addition, stops include examination of an Ohlone Indian heritage site and the New Almaden Mining Museum.

  1. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae) from Cerro Fatal on Santa Cruz Island.

    PubMed

    Poulakakis, Nikos; Edwards, Danielle L; Chiari, Ylenia; Garrick, Ryan C; Russello, Michael A; Benavides, Edgar; Watkins-Colwell, Gregory J; Glaberman, Scott; Tapia, Washington; Gibbs, James P; Cayot, Linda J; Caccone, Adalgisa

    2015-01-01

    The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises.

  2. Late Cretaceous-early Eocene counterclockwise rotation of the Fueguian Andes and evolution of the Patagonia-Antarctic Peninsula system

    NASA Astrophysics Data System (ADS)

    Poblete, F.; Roperch, P.; Arriagada, C.; Ruffet, G.; Ramírez de Arellano, C.; Hervé, F.; Poujol, M.

    2016-02-01

    The southernmost Andes of Patagonia and Tierra del Fuego present a prominent arc-shaped structure: the Patagonian Bend. Whether the bending is a primary curvature or an orocline is still matter of controversy. New paleomagnetic data have been obtained south of the Beagle Channel in 39 out of 61 sites. They have been drilled in Late Jurassic and Early Cretaceous sediments and interbedded volcanics and in mid-Cretaceous to Eocene intrusives of the Fuegian Batholith. The anisotropy of magnetic susceptibility was measured at each site and the influence of magnetic fabric on the characteristic remanent magnetizations (ChRM) in plutonic rocks was corrected using inverse tensors of anisotropy of remanent magnetizations. Normal polarity secondary magnetizations with west-directed declination were obtained in the sediments and they did not pass the fold test. These characteristic directions are similar to those recorded by mid Cretaceous intrusives suggesting a remagnetization event during the normal Cretaceous superchron and describe a large (> 90°) counterclockwise rotation. Late Cretaceous to Eocene rocks of the Fueguian Batholith, record decreasing counterclockwise rotations of 45° to 30°. These paleomagnetic results are interpreted as evidence of a large counterclockwise rotation of the Fueguian Andes related to the closure of the Rocas Verdes Basin and the formation of the Darwin Cordillera during the Late Cretaceous and Paleocene. The tectonic evolution of the Patagonian Bend can thus be described as the formation of a progressive arc from an oroclinal stage during the closure of the Rocas Verdes basin to a mainly primary arc during the final stages of deformation of the Magallanes fold and thrust belt. Plate reconstructions show that the Antarctic Peninsula would have formed a continuous margin with Patagonia between the Early Cretaceous and the Eocene, and acted as a non-rotational rigid block facilitating the development of the Patagonian Bend.

  3. The sedimentology and dynamics of crater-affiliated wind streaks in western Arabia Terra, Mars and Patagonia, Argentina

    USGS Publications Warehouse

    Rodriguez, J.A.P.; Tanaka, K.L.; Yamamoto, A.; Berman, D.C.; Zimbelman, J.R.; Kargel, J.S.; Sasaki, S.; Jinguo, Y.; Miyamoto, H.

    2010-01-01

    Wind streaks comprise recent aeolian deposits that have been extensively documented on Venus, Earth and Mars. Martian wind streaks are among the most abundant surface features on the planet and commonly extend from the downwind margins of impact craters. Previous studies of wind streaks emerging from crater interior deposits suggested that the mode of emplacement was primarily related to the deposition of silt-sized particles as these settled from plumes. We have performed geologic investigations of two wind streaks clusters; one situated in western Arabia Terra, a region in the northern hemisphere of Mars, and another in an analogous terrestrial site located in southern Patagonia, Argentina, where occurrences of wind streaks emanate from playas within maar craters. In both these regions we have identified bedforms in sedimentary deposits on crater floors, along wind-facing interior crater margins, and along wind streaks. These observations indicate that these deposits contain sand-sized particles and that sediment migration has occurred via saltation from crater interior deposits to wind streaks. In Arabia Terra and in Patagonia wind streaks initiate from crater floors that contain lithic and evaporitic sedimentary deposits, suggesting that the composition of wind streak source materials has played an important role in development. Spatial and topographic analyses suggest that regional clustering of wind streaks in the studied regions directly correlates to the areal density of craters with interior deposits, the degree of proximity of these deposits, and the craters' rim-to-floor depths. In addition, some (but not all) wind streaks within the studied clusters have propagated at comparable yearly (Earth years) rates. Extensive saltation is inferred to have been involved in its propagation based on the studied terrestrial wind streak that shows ripples and dunes on its surface and the Martian counterpart changes orientation toward the downslope direction where it

  4. Dog overpopulation and burden of exposure to canine distemper virus and other pathogens on Santa Cruz Island, Galapagos.

    PubMed

    Diaz, Nicole M; Mendez, Gabriella S; Grijalva, C Jaime; Walden, Heather S; Cruz, Marilyn; Aragon, Eduardo; Hernandez, Jorge A

    2016-01-01

    Dog overpopulation and diseases are hazards to native island species and humans on the Galapagos. Vaccination and importation of dogs are prohibited on the Galapagos. Risk management of these hazards requires the use of science-based risk assessment and risk communication. The objectives of the study reported here were (i) to estimate the human:dog ratio and (ii) the prevalence of and identify exposure factors associated with positive antibody titers to canine distemper virus (CDV) and other pathogens, as well as infection with intestinal parasites in owned dogs on Santa Cruz Island, Galapagos in September 2014. The observed human:dog ratio was 6.148:1 which extrapolates to 2503 dogs (two times more than a recent dog count conducted by Galapagos Biosecurity Agency in March 2014). The proportion of spayed female dogs (50%) was higher, compared to neutered male dogs (30%) (p=0.04). Prevalence of dogs with positive antibody titers to CDV was 36% (95% CI=26, 46%), to canine parvovirus was 89% (95% CI=82, 95%), and to canine adenovirus was 40% (95% CI=30, 51%). The frequency of seropositive dogs to CDV was lower in urban dogs (26%), compared to rural dogs (53%) (p<0.05). A positive interaction effect between rural residence and spay/neuter status on seropositivity to CDV was observed, which we discuss in this report. Because vaccination is prohibited, the dog population on Santa Cruz is susceptible to an outbreak of CDV (particularly among urban dogs) with potential spill over to marine mammals. Dog's age (1-2 or 3-14 years old, compared to younger dogs), and residence (rural, urban) were associated with positive antibody titers to parvovirus, adenovirus, Ehrlichia spp., or Anaplasma spp., as well as infection with Ancylostoma spp., an intestinal parasite in dogs that can be transmitted to humans, particularly children. These results provide the most comprehensive assessment of dog overpopulation and exposure to CDV and other pathogens on the Galapagos to date.

  5. Are Vegetative Reproduction Capacities the Cause of Widespread Invasion of Eurasian Salicaceae in Patagonian River Landscapes?

    PubMed Central

    Thomas, Lisa K.; Tölle, Lena; Ziegenhagen, Birgit; Leyer, Ilona

    2012-01-01

    In recent decades, invasive willows and poplars (Salicaceae) have built dense floodplain forests along most of the rivers in Patagonia, Argentina. These invasion processes may affect Salix humboldtiana as the only native floodplain tree species in this region. It is assumed, that the property to reproduce vegetatively can play an important role in the establishment of invasive species in their new range. Thus, in order to contribute to a better understanding of willow and poplar invasions in riparian systems and to assess the potential impacts on S. humboldtiana the vegetative reproduction capacities of native and invasive Salicaceae were analysed. In a greenhouse experiment, we studied cutting survival and growth performance of the three most dominant invasive Salicaceae of the Patagonian Río Negro region (two Salix hybrids and Populus spec.), as well as S. humboldtiana, taking into account three different moisture and two different soil conditions. In a subsequent experiment, the shoot and root biomass of cuttings from the former experiment were removed and the bare cuttings were replanted to test their ability to re-sprout. The two invasive willow hybrids performed much better than S. humboldtiana and Populus spec. under all treatment combinations and tended to re-sprout more successfully after repeated biomass loss. Taking into account the ecology of vegetative and generative recruits of floodplain willows, the results indicate that the more vigorous vegetative reproduction capacity can be a crucial property for the success of invasive willow hybrids in Patagonia being a potential threat for S. humboldtiana. PMID:23226531

  6. High potential of nitrogen fixation in pristine, ombrotrophic bogs in Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Knorr, Klaus-Holger; Horn, Marcus A.; Bahamonde Aguilar, Nelson A.; Borken, Werner

    2015-04-01

    Nitrogen (N) input in pristine peatlands occurs via natural input of inorganic N through atmospheric deposition or biological dinitrogen (N2) fixation. However, N2 fixation is to date mostly attributed to bacteria and algae associated to Sphagnum and its contribution to plant productivity and peat buildup has been often underestimated in previous studies. Based on net N storage, exceptionally low N deposition, and high abundance of vascular plants at pristine peatlands in Southern Patagonia, we hypothesized that there must be a high potential of non-symbiotic N2 fixation not limited to the occurrence of Sphagnum. To this end, we chose two ombrotrophic bogs with spots that are dominated either by Sphagnum or by vascular, cushion-forming plants and sampled peat from different depths for incubation with 15N2 to determine N2 fixation potentials. Moreover, we analyzed 15N2 fixation by a nodule-forming, endemic conifer inhabiting the peatlands. Results from 15N2 uptake were compared to the conventional approach to study N2 fixation by the acetylene reduction assay (ARA). Using 15N2 as a tracer, high non-symbiotic N2 fixation rates of 0.3-1.4 μmol N g-1 d-1 were found down to 50 cm under micro-oxic conditions (2 vol.%) in samples from both plots either covered by Sphagnum magellanicum or by vascular cushion plants. Peat N concentrations suggested a higher potential of non-symbiotic N2 fixation under cushion plants, likely because of the availability of easily decomposable organic compounds as substrates and oxic conditions in the rhizosphere. In the Sphagnum plots, high N2 fixation below 10 cm depth would rather reflect a potential fixation that may switch on during periods of low water levels when oxygen penetrates deeper into the peat. 15N natural abundance of live Sphagnum from 0-10 cm pointed to N uptake solely from atmospheric deposition and non-symbiotic N2 fixation. 15N signatures of peat from the cushion plant plots indicated additional N supply from N

  7. Recent acceleration of ice loss in the Northern Patagonia Icefield based on an updated decennial evolution

    NASA Astrophysics Data System (ADS)

    López, P.; Casassa, G.

    2011-12-01

    Ice elevation changes of the Northern Patagonia Icefield (NPI) were analyzed by comparing three Digital Elevation Models (DEM) corresponding to 1975 (constructed based on topographic maps), the SRTM DEM of 2000 yr and a SPOT 5 DEM of 2005. In addition, the glacier length fluctuations and the surface area evolution between 2001 and 2011 of 25 glaciers of the NPI were studied: the information extracted from the Landsat ETM+ satellite image of 11 March 2001 was compared to the measurements performed based on the Landsat ETM+ satellite image of 19 February 2011. From a global point of view, the majority of the studied glaciers thinned, retreated and lost surface between 2001 and 2011, only few glaciers (Leones, Nef, Pared Sur and Soler) located on the eastern side of the NPI have been stable. Glaciers located on the western side of the NPI suffered a stronger wasting compared to the glaciers located on the eastern side. Overall, over the ablation areas of the NPI (below 1150 m a.s.l.) a more rapid thinning of 2.6 m yr-1 occurred between 2000 and 2005 yr compared to the period 1975-2000, in which a mean thinning of 1.7 m yr-1 was measured for the same zones of the NPI. For the whole period (1975-2005) the most important thinning of the ablation areas has been estimated for HPN-1 Glacier (4.4 m yr-1) followed by Benito (3.4 m yr-1), Fraenkel (2.4 m yr-1), Gualas (2.1 m yr-1) and Acodado glaciers, all of them located on the western side of the NPI. Between 2001 and 2011, a noteworthy retreat of 1.9 km was experienced by Gualas Glacier and by Reichert Glacier with 1.6 km, both located on the north-western side of the NPI. On the south-western side of the NPI, during the same decennia, Steffen Glacier experienced a remarkable retreat of 1.6 km as well. During the 2001-2011 period, Steffen Glacier more than doubled its rate of retreat (compared to the 1979-2001 period) and experienced the disintegration of its main front as well as a lateral tongue that retreated 3.1 km. The

  8. Depositional Environments of Late Danian Plant Localities: Chubut Provice, Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Comer, E.; Slingerland, R. L.; Wilf, P.

    2010-12-01

    Diverse, well-preserved macroflora are observed within Cretaceous and Paleocene sediments of Chubut Province, Patagonia, Argentina. These macroflora are the most well preserved early Paleocene flora from Gondwana and add new insight into the diversity and environments of that epoch. Two major sites of fossil preservation, Palacio de los Loros and Parque Provincial Ormachea, sit near the top of the Late Danian (65.5-61.7 Ma) Salamanca Formation. Understanding the depositional history of the Salamanca is important in characterizing paleoenvironments in which these flora lived and relating these Patagonian macroflora to concurrent Paleocene flora within the Gondwanan supercontinent. During a two week field season, twenty stratigraphic sections were measured along the outcrop belt at Palacio de los Loros and Ormachea Park as well as two minor sites; Las Flores, and Rancho Grande. Photo mosaics, laser ranger data, and stratigraphic columns were merged with elevated geologic maps and imported into Fledermaus to generate a 3-D visualization of facies relationships. Rock samples were also collected and will be thin sectioned and analyzed for petrography and grain size. The Salamanca Fm. consists of 7 facies, listed here in stratigraphically ascending order: 1)Transgressive sands, 2)Wispy-bedded claystone, 3)Banco Verde, 4)White Cross bedded sandstone, 5)Accretion set siltstone, 6)Transitional silty claystone and 7)Banco Negro. Based on these facies, the Salamanca Fm. is interpreted as a marine-shelf to brackish, tide-dominated, estuarine deposit. The base of the Salamanca Fm. rests on an unconformity representing a marine flooding surface and lower sections of the Salamanca, facies 1 and 2, contain abundant glauconite and fossils indicative of a marine shelf environment. These facies give way upwards to bi-directional trough cross bedded sandstones interspersed with flaser bedded sandy siltstones (facies 3 and 4) indicating a less marine estuary with strong flow regimes

  9. Palynological analysis of camelid coprolites: seasonality in the use of the site Cerro Casa de Piedra 7 (Santa Cruz, Argentina)

    NASA Astrophysics Data System (ADS)

    Velázquez, Nadia Jimena; Burry, Lidia Susana; Fugassa, Martín Horacio; Civalero, María Teresa; Aschero, Carlos Alberto

    2014-01-01

    Palynological, palaeoparasitological and paleobotanical studies of coprolites found in archaeological sites from Perito Moreno National Park (47°57‧S72°05‧W) yielded information on diet, palaeoenvironment and health. These studies allowed adding evidence to the reconstruction of life history of the hunter-gatherers that inhabited Patagonia during the Holocene. We examined the season of the year when camelid Lama guanicoe coprolites (5400 ± 64 yr 14C BP to 9640 ± 190 yr 14C BP) were deposited at Cerro Casa de Piedra 7 (site CCP7). The study used palynological evidence and comparison with pollen spectra of modern feces collected during summer, fall, winter and spring of 2010. The dominant types were: pollen of Nothofagus, Empetrum rubrum, Asteraceae subfam. Asteroideae, Nassauvia, Caryophyllaceae and Poaceae; fern spores; remains of Eimeria macusaniensis; and plant remains of Poaceae, Festuca pallescens, Stipa speciosa, Armeria maritima, Gaultheria mucronata and E. rubrum. Pollen spectra of modern and fossil feces were used for multivariate analysis. Coprolites associated to fall and winter modern feces. These results and those obtained from pollen concentration values and the presence of pollen types indicators of seasonality, allowed the determination of summer, fall and winter coprolites. However, caution must be taken with the seasonality results of coprolites dated earlier than 9000 years BP since the environmental conditions differed from now. The site was probably a camelid shelter during the unfavorable seasons.

  10. River Times.

    ERIC Educational Resources Information Center

    Auldridge, Teresa; And Others

    The James River is one of the most precious resources of Virginia. It was the site of the first permanent English settlement in the New World; the power of the water at the Fall Zone was a major factor in the development of Richmond; and the river served as a primary transportation route to the West via the Kanawha Canal. Both the water itself and…

  11. Comparative study of two tsunamigenic earthquakes in the Solomon Islands: 2015 Mw 7.0 normal-fault and 2013 Santa Cruz Mw 8.0 megathrust earthquakes

    NASA Astrophysics Data System (ADS)

    Heidarzadeh, Mohammad; Harada, Tomoya; Satake, Kenji; Ishibe, Takeo; Gusman, Aditya Riadi

    2016-05-01

    The July 2015 Mw 7.0 Solomon Islands tsunamigenic earthquake occurred ~40 km north of the February 2013 Mw 8.0 Santa Cruz earthquake. The proximity of the two epicenters provided unique opportunities for a comparative study of their source mechanisms and tsunami generation. The 2013 earthquake was an interplate event having a thrust focal mechanism at a depth of 30 km while the 2015 event was a normal-fault earthquake occurring at a shallow depth of 10 km in the overriding Pacific Plate. A combined use of tsunami and teleseismic data from the 2015 event revealed the north dipping fault plane and a rupture velocity of 3.6 km/s. Stress transfer analysis revealed that the 2015 earthquake occurred in a region with increased Coulomb stress following the 2013 earthquake. Spectral deconvolution, assuming the 2015 tsunami as empirical Green's function, indicated the source periods of the 2013 Santa Cruz tsunami as 10 and 22 min.

  12. Soils of the coastal area of Santa Fé and Santa Cruz islands (Galápagos). Their micromorphology, mineralogy and genesis compared.

    NASA Astrophysics Data System (ADS)

    Stoops, Georges; Dumon, Mathijs; Van Ranst, Eric

    2015-04-01

    Santa Fé is a small island situated about 15 km SW of Santa Cruz and has a similar petrographic composition. The centre of Santa Cruz reaches up to 950 m a.s.l., Santa Fé is nowhere higher that 255 m. Even in the dry season the high mountain region of Santa Cruz profits therefore of an almost continuous drizzly rain (garrúa) resulting from the cooling of the rising moist air. The dry coastal zones are covered by sparse Opuntia vegetation. In the coastal soils a double to open spaced porphyric c/f related distribution pattern prevails. The micromass is greyish to yellowish brown on Santa Fé, reddish on Santa Cruz. The b-fabric is weakly granostriated, rarely calcitic crystallitic. The coarse material is restricted to fresh grains of plagioclase > iddingsite > augite > rare olivine, and some fresh basalt fragments. Remnants of illuvial clay coatings are more common on Santa Cruz. Only on Santa Fé hard, yellowish nodules (up to 700 µm) with a strongly mosaic speckled b-fabric and first order grey interference colours occur; their nature and genesis is a point of discussion. X-ray diffraction revealed the clay fraction of these soils to be comparable: poorly crystalline 2:1 phyllosilicates with broad irregular 001 reflections swelling to 1.8 nm after glycolation and collapsing to 1.0 nm after K-saturation and heating. Poorly crystalline kaolinite reflections are more prominent on Santa Cruz, whereas mica-like components (1.00 nm reflections) are restricted to Santa Fé. The presence of unweathered coarse material in an abundant micromass of alteration clay indicates a disequilibrium, and points to a transport of the fine material, in solid phase (colluvium) and/or as solution rather than an in situ weathering. Comparing the total chemical composition (corrected for LOI) of the coastal soils of Santa Cruz and Santa Fé with the average rock composition of both islands, one notes in the soils an increase in Al, Fe, Ti and K, and a loss of Mg, Ca and Na. On Santa F

  13. Measuring the impacts of natural amenities and the US-Mexico Border, on housing values in the Santa Cruz Watershed, using spatially-weighted hedonic modeling

    USGS Publications Warehouse

    Amaya, Gladys; Norman, Laura M.; Frisvold, George

    2011-01-01

    This presentation will provide a synopsis of the quality of life and hedonics literature review used to develop this research agenda. Variables relevant for local environmental management, having significant effects on property values, will be discussed. The final results obtained from this study can be used determine the benefits of preserving or developing land binationally and will be uploaded to the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM), an online Ecosystem Services tool, being created to promote sustainable development in the Borderlands.

  14. Type material of Platyhelminthes (Monogenoidea) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016.

    PubMed

    Lopes, Daniela A; Mainenti, Adriana; Sanches, Magda; Knoff, Marcelo; Gomes, Delir Corrêa

    2016-01-01

    A catalogue of type material of monogenoids deposited in the Helminthological Collection of the Oswaldo Cruz Institute, FIOCRUZ (CHIOC), between 1979 and 2016, is presented, given that the last list of types was produced in 1979. The monogenoid collection comprises type lots for 203 species, distributed across 14 families and 68 genera. Specific names are listed systematically, followed by type host, infection site, type locality, specimens with the collection numbers and references. The classification and the nomenclature of the species have been updated.

  15. Causes of mortality of wild birds submitted to the Charles Darwin Research Station, Santa Cruz, Galapagos, Ecuador from 2002-2004.

    PubMed

    Gottdenker, Nicole L; Walsh, Timothy; Jiménez-Uzcátegui, Gustavo; Betancourt, Franklin; Cruz, Marilyn; Soos, Catherine; Miller, R Eric; Parker, Patricia G

    2008-10-01

    Necropsy findings were reviewed from wild birds submitted to the Charles Darwin Research Station, Santa Cruz Island, Galápagos Archipelago between 2004 and 2006. One hundred and ninety cases from 27 different species were submitted, and 178 of these cases were evaluated grossly or histologically. Trauma and trauma-related deaths (n=141) dominated necropsy submissions. Infectious causes of avian mortality included myiasis due to Philornis sp. (n=6), avian pox (n=1), and schistosomosis (n=1).

  16. Panmixia supports divergence with gene flow in Darwin's small ground finch, Geospiza fuliginosa, on Santa Cruz, Galápagos Islands.

    PubMed

    Galligan, Toby H; Donnellan, Stephen C; Sulloway, Frank J; Fitch, Alison J; Bertozzi, Terry; Kleindorfer, Sonia

    2012-05-01

    The divergence-with-gene-flow model of speciation has a strong theoretical basis with a growing number of plausible examples in nature, but remains hotly debated. Darwin's finches of the Galápagos Archipelago have played an important role in our understanding of speciation processes. Recent studies suggest that this group may also provide insights into speciation via divergence with gene flow. On the island of Santa Cruz, recent studies found evidence for adaptive divergence in Darwin's small ground finch, Geospiza fuliginosa, between ecologically contrasting arid and humid zones. Despite the short geographical distance between these zones, strong disruptive selection during low rainfall periods is expected to generate and maintain adaptive divergence. Conversely, during high rainfall periods, when disruptive selection is predicted to be weakened, population divergence in adaptive traits is expected to break down. Because periods of low and high rainfall irregularly alternate, the geographical pattern of adaptive divergence can be assumed to break down and, importantly, regenerate in situ. Here, we use microsatellite allele frequency data to assess the genetic population structure of G. fuliginosa on Santa Cruz. We sample 21 sites and four ecological zones across the island. We reject hypotheses of population substructure linked to ecological and geographical differences among sites in favour of a single panmictic population. Panmixia implies high levels of gene flow within Santa Cruz, which favours selection over genetic drift as a valid process generating phenotypic divergence in G. fuliginosa on Santa Cruz. We discuss how our findings may support classic adaptation, phenotypic plasticity, matching habitat choice or any combination of these three processes.

  17. Carbon and nitrogen isotope composition of core catcher samples from the ICDP deep drilling at Laguna Potrok Aike (Patagonia, Argentina)

    NASA Astrophysics Data System (ADS)

    Luecke, Andreas; Wissel, Holger; Mayr*, Christoph; Oehlerich, Markus; Ohlendorf, Christian; Zolitschka, Bernd; Pasado Science Team

    2010-05-01

    The ICDP project PASADO aims to develop a detailed paleoclimatic record for the southern part of the South American continent from sediments of Laguna Potrok Aike (51°58'S, 70°23'W), situated in the Patagonian steppe east of the Andean cordillera and north of the Street of Magellan. The precursor project SALSA recovered the Holocene and Late Glacial sediment infill of Laguna Potrok Aike and developed the environmental history of the semi-arid Patagonian steppe by a consequent interdisciplinary multi-proxy approach (e.g. Haberzettl et al., 2007). From September to November 2008 the ICDP deep drilling took place and successfully recovered in total 510 m of sediments from two sites resulting in a composite depth of 106 m for the selected main study Site 2. A preliminary age model places the record within the last 50.000 years. During the drilling campaign, the core catcher content of each drilled core run (3 m) was taken as separate sample to be shared and distributed between involved laboratories long before the main sampling party. A total of 70 core catcher samples describe the sediments of Site 2 and will form the base for more detailed investigations on the palaeoclimatic history of Patagonia. We here report on the organic carbon and nitrogen isotope composition of bulk sediment and plant debris of the core catcher samples. Similar investigations were performed for Holocene and Late Glacial sediments of Laguna Potrok Aike revealing insights into the organic matter dynamics of the lake and its catchment as well as into climatically induced hydrological variations with related lake level fluctuations (Mayr et al., 2009). The carbon and nitrogen content of the core catcher fine sediment fraction (<200 µm) is low to very low (around 1 % and 0.1 %, respectively) and requires particular attention in isotope analysis. The carbon isotope composition shows comparably little variation around a value of -26.0 per mil. The positive values of the Holocene and the Late

  18. Hydrogeologic Framework of the Upper Santa Cruz Basin (Arizona and Sonora) using Well Logs, Geologic Mapping, Gravity, Magnetics, and Electromagnetics

    NASA Astrophysics Data System (ADS)

    Callegary, J. B.; Page, W. R.; Megdal, S.; Gray, F.; Scott, C. A.; Berry, M.; Rangel, M.; Oroz Ramos, L.; Menges, C. M.; Jones, A.

    2011-12-01

    In 2006, the U.S. Congress passed the U.S.-Mexico Transboundary Aquifer Assessment Act which provides a framework for study of aquifers shared by the United States and Mexico. The aquifer of the Upper Santa Cruz Basin was chosen as one of four priority aquifers for several reasons, including water scarcity, a population greater than 300,000, groundwater as the sole source of water for human use, and a riparian corridor that is of regional significance for migratory birds and other animals. Several new mines are also being proposed for this area which may affect water quality and availability. To date, a number of studies have been carried out by a binational team composed of the U.S. Geological Survey, the Mexican National Water Commission, and the Universities of Arizona and Sonora. Construction of a cross-border hydrogeologic framework model of the basin between Amado, Arizona and its southern boundary in Sonora is currently a high priority. The relatively narrow Santa Cruz valley is a structural basin that did not experience the same degree of late Cenozoic lateral extension and consequent deepening as found in other basin-and-range alluvial basins, such as the Tucson basin, where basin depth exceeds 3000 meters. This implies that storage may be much less than that found in other basin-and-range aquifers. To investigate the geometry of the basin and facies changes within the alluvium, a database of over one thousand well logs has been developed, geologic mapping and transient electromagnetic (TEM) surveys have been carried out, and information from previous electromagnetic, magnetic, and gravity studies is being incorporated into the hydrogeologic framework. Initial geophysical surveys and analyses have focused on the portion of the basin west of Nogales, Arizona, because it supplies approximately 50% of that city's water. Previous gravity and magnetic modeling indicate that this area is a narrow, fault-controlled half graben. Preliminary modeling of airborne

  19. Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina.

    PubMed

    Hernández-Orts, J S; Montero, F E; Juan-García, A; García, N A; Crespo, E A; Raga, J A; Aznar, F J

    2013-09-01

    We report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, from northern Patagonia, Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllobothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s., Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi and Corynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. and P. chasmagnathi represent new host records. A total of 1516 helminth specimens were collected from fur seals. Gravid individuals were represented by three species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosoma australe was the most prevalent and abundant parasite in both hosts, accounting for >90% of all specimens. Sea lions and furs seals from northern Patagonia harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation of species richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of

  20. The Last Transition From Extreme Glacial to Extreme Interglacial Climate in NW Patagonia: Regional and Global Implications

    NASA Astrophysics Data System (ADS)

    Moreno, P. I.

    2004-12-01

    The study of interhemispheric climate linkages during and since the last ice age has benefited from the recent development of high-resolution ice core and marine records from the mid- and high latitudes of the Southern Hemisphere. Few paleoclimate records from terrestrial environments in these regions, however, have the temporal continuity, time resolution, and adequate chronologic control to allow a detailed examination of the timing, rates, direction, and phasing of climate change at millennial timescales. Stratigraphic, palynologic, and charcoal records from small, high-sediment accumulating lakes in the Chilean Lake District (41ºS) afford useful data for examining the interval between the LGM to the early Holocene (25-8 ka, ka=cal kyr BP). Millennial-scale changes in glacier extent and vegetation patterns within this interval match key events both in the Northern Hemisphere and Antarctic records, in particular the EPICA Dome C data, highlighting the role of an atmosphere-based conduit for the global propagation of abrupt climate changes. The onset of the last termination in NW Patagonia is marked by glacial collapse and the expansion of rainforest trees at 17.7 ka. An apparent antiphase relationship among the polar hemispheres between 17.7-14.7 ka, might reflect the hemispheric-scale effects of a quasi-total shut down of Atlantic Meridional Overturning circulation driven by Heinrich event 1. Extreme glacial and interglacial modes in the position/strength of the westerlies at multi-millennial timescales in the southern westerlies accompany important shifts in the abundance and composition of rainforest communities during the last termination and the early Holocene. At millennial timescales, this interval is characterised by successive warming pulses interrupted by a generalized reversal in trend with cooling events starting at 14.7 and 13.4 ka. Fires between 12.9-11.5 ka, i.e. Younger Dryas Chron (YDC), led to the expansion of opportunistic rainforest species

  1. Chemical and petrological heterogenity of lithospheric mantle beneath N Patagonia (Argentina) - case study of Cerro Chenque xenoliths.

    NASA Astrophysics Data System (ADS)

    Kozdrowska, Dominika; Matusiak-Małek, Magdalena; Ntaflos, Theodoros; Puziewicz, Jacek; Bjerg, Ernesto

    2015-04-01

    Mantle-xenoliths-bearing, back-arc Pliocene - Quaternary alkali basalts occur in N Patagonia, Argentina (Bjerg et al., 2005, J. of S. Am. Sci.). The Cerro Chenque (Rio Negro province) trachybasaltic lavas carry small (up to 10 cm in diameter) xenoliths of anhydrous, spinel bearing harzburgites, dunites and less abundant clino- , orthopyroxenites, websterites. The xenolith suite comprises also gabbros and norites, which are not discussed in this study. All the phases forming xenoliths are rich in Mg (Fo=90.5-93.5%; mg#Opx=0.90-0.94; mg#Cpx=0.91-0.95). Composition of spinel is extremely variable (mg#=0.65-0.85; cr#=0.00-0.70). Three types (A, B, C) of REE patterns occur in clinopyroxene and orthopyroxene: (1) type A (harzburgites and orthopyroxenites) is U-shaped in both the pyroxenes, REE contents vary significantly (e.g. La=~0.5 primitive mantle values (PM), ~5 PM, and ~50PM); (2) type B (dunites and harzburgites) clinopyroxene has flat HREE and is continuously enriched in LREE up to 10x PM, orthopyroxene is U-shaped; (3) type C (harzburgites) clinopyroxene is convex upward, La=5-7PM), orthopyroxene is continuously depleted in LREE. Clinopyroxene of all the types is poor in Ti, while normalized content of other trace elements is strongly variable. Trace element compositions of Cerro Chenque xenolithc clinopyroxene cover whole compositional range of mantle-derived clinopyroxene from Rio Negro province presented by Bjerg et al., 2005 (op.cit.). In xenoliths where clino- and orthopyroxene are in equilibrium, the calculated temperatures are always around 1000°C (Brey and Köhler,1990, JoP). No spinel-clinopyroxene symplectites suggesting peridotite provenance from garnet stability field were observed. Strong variations in rock-type and chemical composition of minerals forming Cerro Chenque xenoliths suggest complicated structure of upper mantle beneath N Patagonia. At present stage of study we suggest that Earth's lithospheric mantle in this region: - suffered from

  2. CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)

    NASA Astrophysics Data System (ADS)

    Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica

    2015-04-01

    South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum

  3. Petrogenesis of spinel peridotite suite xenoliths from northern Santa Cruz province, Argentina; implication for the Patagonian Lithospheric Mantle

    NASA Astrophysics Data System (ADS)

    Ntaflos, Theodoros; Mundl, Andrea; Bjerg, Ernesto; Tschegg, Cornelius; Kosler, Jan

    2010-05-01

    Mantle xenoliths from Don Camilo, an area located on the North margin of the Deseado Masiff in Patagonia, comprise spinel bearing lherzolites, harburgites and dunites, wehrlites, clinopyroxenites and gabbros. The most common rock type in our collection is spinel-lherzolite followed by dunites. Harzurgites, wehrlites and gabbros are less widespread. Spinel-lherzolites and harzburgites have protogranular textures whereas dunites have equigranular to equigranular tabular textures. There are two kinds of dunites: mantle dunites and cumulate dunites. The olivine mg# in the mantle dunites vary within a narrow range, from 90.5 to 91.5 and the NiO content from 0.39 to 0.42 wt%, whereas in the cumulate dunites the mg# ranges from 87 to 90.5 and the NiO content from 0.22 to 0.40 wt%. Both types of dunites contain fine grained interstitial diopside. Hydrous phases, besides one sample that contains amphibole, were so far not found. The spinel peridotites have whole rock REE abundances depleted in LREE [(La/Yb)N=0.34-0.85)] and the dunites are LREE enriched [(La/Yb)N=3.49]. LA-ICP-MS analyses of cpx show that a number of the studied spinel peridotite xenoliths experienced cryptic metasomatism. Three groups of xenoliths have been recognized according to REE and other incompatible trace element patterns in cpx: group I has depleted LREE abundances, group II is highly enriched in LREE (20-30 x PM) and group 3 has moderate LREE enrichments. The core of some clinopyroxenes in group II has depleted LREE similar to those in group I, apparently representing relictic cores not affected by metasomatism. In addition the metasomatized clinopyroxenes are significantly enriched in Sr, Th and U. Evidently, the metasomatic agent was a H2O-rich fluid (high LREE, Sr, Th and U). Clinopyroxene Sr and Nd isotopic ratios vary largely from 0.702671 to 0.705788 and from 0.51229 to 0.513251 respectively. Mantle and cumulate dunites have experienced modal metasomatism. In both types of dunites the

  4. Triggered aseismic slip adjacent to the 6 February 2013 Mw 8.0 Santa Cruz Islands megathrust earthquake

    NASA Astrophysics Data System (ADS)

    Hayes, Gavin P.; Furlong, Kevin P.; Benz, Harley M.; Herman, Matthew W.

    2014-02-01

    Aseismic or slow slip events have been observed in many subduction zones, but whether they affect the occurrence of earthquakes or result from stress changes caused by nearby events is unclear. In an area lacking direct geodetic observations, inferences can be made from seismological studies of co-seismic slip, associated stress changes and the spatiotemporal nature of aftershocks. These observations indicate that the February 2013 Mw 8.0 Santa Cruz Islands earthquake may have triggered slow or aseismic slip on an adjacent section of the subduction thrust over the following hours to days. This aseismic event was equivalent to Mw 7.6, significantly larger than any earthquakes in the aftershock sequence. The aseismic slip was situated within the seismogenic portion of the subduction interface, and must have occurred to the south of the main seismic slip and most aftershocks in order to promote right-lateral faulting in the upper plate, the dominant deformation style of the aftershock sequence. This plate boundary segment can support either stable sliding (aseismic) or stick-slip (seismic) deformation in response to different driving conditions. The complete lack of aftershocks on the thrust interface implies this pair of megathrust slip episodes (seismic and aseismic) released a substantial portion of the stored strain on the northernmost section of the Vanuatu subduction zone.

  5. A multitemporal (1979-2009) land-use/land-cover dataset of the binational Santa Cruz Watershed

    USGS Publications Warehouse

    2011-01-01

    Trends derived from multitemporal land-cover data can be used to make informed land management decisions and to help managers model future change scenarios. We developed a multitemporal land-use/land-cover dataset for the binational Santa Cruz watershed of southern Arizona, United States, and northern Sonora, Mexico by creating a series of land-cover maps at decadal intervals (1979, 1989, 1999, and 2009) using Landsat Multispectral Scanner and Thematic Mapper data and a classification and regression tree classifier. The classification model exploited phenological changes of different land-cover spectral signatures through the use of biseasonal imagery collected during the (dry) early summer and (wet) late summer following rains from the North American monsoon. Landsat images were corrected to remove atmospheric influences, and the data were converted from raw digital numbers to surface reflectance values. The 14-class land-cover classification scheme is based on the 2001 National Land Cover Database with a focus on "Developed" land-use classes and riverine "Forest" and "Wetlands" cover classes required for specific watershed models. The classification procedure included the creation of several image-derived and topographic variables, including digital elevation model derivatives, image variance, and multitemporal Kauth-Thomas transformations. The accuracy of the land-cover maps was assessed using a random-stratified sampling design, reference aerial photography, and digital imagery. This showed high accuracy results, with kappa values (the statistical measure of agreement between map and reference data) ranging from 0.80 to 0.85.

  6. late Pleistocene and Holocene pollen record from Laguna de las Trancas, northern coastal Santa Cruz County, California

    USGS Publications Warehouse

    Adam, David P.; Byrne, Roger; Luther, Edgar

    1981-01-01

    A 2.1-m core from Laguna de las Trancas, a marsh atop a landslide in northern Santa Cruz County, California, has yielded a pollen record for the period between about 30,000 B. P. and roughly 5000 B. P. Three pollen zones are recognized. The earliest is characterized by high frequencies of pine pollen and is correlated with a mid-Wisconsinan interstade of the mid-continent. The middle zone contains high frequencies of both pine and fir (Abies, probably A. grandis) pollen and is correlated with the last full glacial interval (upper Wisconsinan). The upper zone is dominated by redwood (Sequoia) pollen and represents latest Pleistocene to middle Holocene. The past few thousand years are not represented in the core. The pollen evidence indicates that during the full glacial period the mean annual temperature at the site was about 2°C to 3°C lower than it is today. We attribute this small difference to the stabilizing effect of marine upwelling on the temperature regime in the immediate vicinity of the coast. Precipitation may have been about 20 percent higher as a result of longer winter wet seasons.

  7. Triggered aseismic slip adjacent to the 6 February 2013 Mw 8.0 Santa Cruz Islands megathrust earthquake

    USGS Publications Warehouse

    Hayes, Gavin P.; Furlong, Kevin P.; Benz, Harley M.; Herman, Matthew W.

    2014-01-01

    Aseismic or slow slip events have been observed in many subduction zones, but whether they affect the occurrence of earthquakes or result from stress changes caused by nearby events is unclear. In an area lacking direct geodetic observations, inferences can be made from seismological studies of co-seismic slip, associated stress changes and the spatiotemporal nature of aftershocks. These observations indicate that the February 2013 Mw 8.0 Santa Cruz Islands earthquake may have triggered slow or aseismic slip on an adjacent section of the subduction thrust over the following hours to days. This aseismic event was equivalent to Mw 7.6, significantly larger than any earthquakes in the aftershock sequence. The aseismic slip was situated within the seismogenic portion of the subduction interface, and must have occurred to the south of the main seismic slip and most aftershocks in order to promote right-lateral faulting in the upper plate, the dominant deformation style of the aftershock sequence. This plate boundary segment can support either stable sliding (aseismic) or stick-slip (seismic) deformation in response to different driving conditions. The complete lack of aftershocks on the thrust interface implies this pair of megathrust slip episodes (seismic and aseismic) released a substantial portion of the stored strain on the northernmost section of the Vanuatu subduction zone.

  8. Slip history of the La Cruz fault: Development of a late Miocene transform in response to increased rift obliquity in the northern Gulf of California

    NASA Astrophysics Data System (ADS)

    Bennett, Scott E. K.; Oskin, Michael E.; Iriondo, Alexander; Kunk, Michael J.

    2016-12-01

    The Gulf of California rift has accommodated oblique divergence of the Pacific and North America plates in northwestern México since Miocene time. Due to its infancy, its rifted margins preserve a rare onshore record of early continental break-up processes and an opportunity to investigate the role of rift obliquity in strain localization. We map rift-related structures and syn-tectonic basins on southern Isla Tiburón, a proximal onshore exposure of the rifted North America margin. We integrate analysis and geochronology of syn-tectonic sedimentary basins and mapping of crosscutting relationships to characterize the style and timing of fault activity. On southern Isla Tiburón, an early phase of extension initiated between 19-17 Ma and 12.2 Ma. Subsequently, these normal faults and related basins were cut by the La Cruz strike-slip fault and buried by deposits of the La Cruz basin, an elongate, fault-controlled trough coextensive with the La Cruz fault. Crosscutting relationships show that the NW-striking La Cruz fault accrued 5 ± 2 km of dextral slip 8-4 Ma. The La Cruz fault and parallel Tiburón transform were kinematically linked to detachment faulting that accommodated latest Miocene to Pliocene oblique opening of the offshore Upper Tiburón pull-apart basin. The onset of strike-slip faulting on Isla Tiburón was synchronous with the 8-6 Ma onset of transform faulting and basin formation along > 1000 km of the reconstructed Pacific-North America plate boundary. This transition coincides with the commencement of a clockwise azimuthal shift in Pacific-North America relative plate motion that increased the obliquity of the Gulf of California rift and formed the Gulf of California shear zone. The record from the proto-Gulf of California illustrates how highly oblique rift geometries, where transform faults are kinematically linked to pull-apart basins, enhance the ability of continental lithosphere to rupture and, ultimately, hasten the formation of new oceanic

  9. Hydrologic and geomorphic changes resulting from episodic glacial lake outburst floods: Rio Colonia, Patagonia, Chile

    NASA Astrophysics Data System (ADS)

    Jacquet, J.; McCoy, S. W.; McGrath, D.; Nimick, D. A.; Fahey, M.; O'kuinghttons, J.; Friesen, B. A.; Leidich, J.

    2017-01-01

    Glacial lake outburst floods (GLOFs) are a prominent but poorly understood cryospheric hazard in a warming climate. We quantify the hydrologic and geomorphic response to 21 episodic GLOFs that began in April 2008 using multitemporal satellite imagery and field observations. Peak discharge exiting the source lake became progressively muted downstream. At 40-60 km downstream, where the floods entered and traveled down the main stem Rio Baker, peak discharges were generally < 2000 m3 s-1, although these flows were still >1-2 times the peak annual discharge of this system, Chile's largest river by volume. As such, caution must be applied to empirical relationships relating lake volume to peak discharge, as the latter is dependent on where this observation is made along the flood path. The GLOFs and subsequent periods of free drainage resulted in > 40 m of incision, the net removal of 25 × 106 m3 of sediment from the source lake basin, and a nonsteady channel configuration downstream. These results demonstrate that GLOFs sourced from low-order tributaries can produce significant floods on major main stem rivers, in addition to significantly altering sediment dynamics.

  10. Population genetic structure and historical population dynamics of the South American sea lion, Otaria flavescens, in north-central Patagonia.

    PubMed

    Túnez, Juan I; Cappozzo, Humberto L; Nardelli, Maximiliano; Cassini, Marcelo H

    2010-08-01

    The north-central Patagonian coast is the sea lions most abundant area in Argentina. As occurs along the entire Atlantic coast, the distribution of breeding colonies at this smaller geographical scale is also patchy, showing at least three areas with breeding activity. We study the genetic structure and historical population dynamics of the species in five colonies in this area, analysing a 508 base-pair segment of the D-loop control region. Otaria flavescens showed 10 haplotypes with 12 polymorphic sites. The genealogical relationship between haplotypes revealed a shallow pattern of phylogeographic structure. The analysis of molecular variance showed significant differences between colonies, however, pairwise comparisons only indicate significant differences between a pair of colonies belonging to different breeding areas. The pattern of haplotype differentiation and the mismatch distribution analysis suggest a possible bottleneck that would have occurred 64,000 years ago, followed by a demographic expansion of the three southernmost colonies. Thus, the historical population dynamics of O. flavescens in north-central Patagonia appears to be closely related with the dynamics of the Late Pleistocene glaciations.

  11. Redescription of Antarctophthirus microchir (Anoplura: Echinophthiriidae) from the South American sea lion, Otaria flavescens, from Patagonia, Argentina.

    PubMed

    Leonardi, M Soledad; Crespo, Enrique A; Raga, Juan Antonio; Fernández, Mercedes

    2009-10-01

    Antarctophthirus microchir was originally described from Phocarctos hookeri on the basis of 1 female and 1 male only. We redescribe adults and describe, for the first time, the 3 nymphal stages from specimens collected from Otaria flavescens from Patagonia, using light and scanning electron microscopy. The present material can be distinguished from other Antarctophthirus species by the presence of a fringe of setae on the back of the head, only present in Antarctophthirus trichechi and Antarctophthirus callorhini. However, A. trichechi also possess a prominent proboscis with large hooks, and A. callorhini presents less abundant and nonuniform abdominal scales in shape and size. Other differential features of A. microchir are the pattern of ovoid and uniform scales and longitudinal grooves in the surface of spines. Nymphal stage 1 differs from 2 and 3 mainly by the absence of scales and thorax without ventral spines or hairs. Nymphal stages 2 and 3 may be distinguished by the disposition of the occipital apophyses. Antarctophthirus microchir has been reported from 5 sea lion species from both hemispheres. Considering the conservative morphology, and ecological and evolutionary features of sucking lice, we raise the question of whether A. microchir from different sea lion hosts may represent a complex of cryptic species.

  12. Persistence of a Mesozoic, non-therian mammalian lineage (Gondwanatheria) in the mid-Paleogene of Patagonia.

    PubMed

    Goin, Francisco J; Tejedor, Marcelo F; Chornogubsky, Laura; López, Guillermo M; Gelfo, Javier N; Bond, Mariano; Woodburne, Michael O; Gurovich, Yamila; Reguero, Marcelo

    2012-06-01

    We describe two isolated molariforms recovered from early-middle Eocene (early Lutetian) levels of northwestern Patagonia, Argentina. Comparisons with major lineages of therian and non-therian mammals lead us to refer them to a new genus and species of Gondwanatheria (Allotheria). There is a single root supporting each tooth that is very short, wide, rounded, and covered by cementum; the steep sidewalls, lack of a neck between the crown and root, and the heavily worn stage in both molariforms suggest that they were of a protohypsodont type. Both teeth are strongly worn at their centers, all along their length, with the labial edge less worn than the lingual; they show strong transverse crests that alternate with lingual grooves. The protohypsodont aspect of the teeth, as well as the strong, transverse crests, are suggestive of sudamericid affinities; on the other hand, the thin enamel layer and the occlusal pattern formed by the crests and grooves shows more similarities to molariform teeth of the Ferugliotheriidae. The new taxon adds evidence regarding the (1) extensive radiation of the Gondwanatheria throughout the Southern Hemisphere, (2) persistence of several lineages well after the Cretaceous/Paleogene boundary, and (3) early evolution of hypsodont types among South American herbivorous mammals.

  13. Bacillus patagoniensis sp. nov., a novel alkalitolerant bacterium from the rhizosphere of Atriplex lampa in Patagonia, Argentina.

    PubMed

    Olivera, Nelda; Siñeriz, Faustino; Breccia, Javier D

    2005-01-01

    A Gram-positive, rod-shaped, spore-forming bacterium (PAT 05T) was isolated from the rhizosphere of the perennial shrub Atriplex lampa in north-eastern Patagonia, Argentina. Its overall biochemical and physiological characteristics indicated that this strain should be placed in the alkaliphilic Bacillus group. Strain PAT 05T grew at pH 7-10 (optimum pH 8), but not at pH 6. Its DNA G+C content was 39.7 mol%. Sequence analysis of the 16S rRNA gene of PAT 05T revealed the closest match (99.6 % similarity) with Bacillus sp. DSM 8714. The highest level of DNA-DNA relatedness (88.6 %) was also found with this strain. On the basis of 16S rRNA gene sequence similarity and phylogenetic analysis, G+C content and DNA-DNA hybridization data, strain PAT 05T is related at the species level to Bacillus sp. DSM 8714, a member of a group referred as phenon 4a by Nielsen et al. [Nielsen, P., Fritze, D. & Priest, F. G. (1995). Microbiology 141, 1745-1761], which still lacks taxonomic standing. These results support the proposal of strain PAT 05T (=DSM 16117T=ATCC BAA-965T) as the type strain of Bacillus patagoniensis sp. nov.

  14. Muscular reconstruction and functional morphology of the hind limb of santacrucian (Early Miocene) sloths (Xenarthra, Folivora) of Patagonia.

    PubMed

    Toledo, Néstor; Bargo, M Susana; Vizcaíno, Sergio F

    2015-05-01

    This article presents a morphofunctional analysis of the hind limb of Santacrucian (Early Miocene) sloths from southernmost Patagonia (Argentina). These fossil sloths were mid sized to large animals, ranging from 40 to 120 kg, and their postcranial skeleton was markedly different in shape compared with that of extant tree sloths, which vary from 2 to 10 kg. The functional anatomy of the hind limb of Santacrucian sloths was compared with that of living xenarthrans (tree sloths, anteaters, and armadillos), which involved reconstruction of the hind limb musculature and comparative and qualitative morphofunctional analyses, and hypotheses on the biological role of the hind limb in terms of preferences in substrate, posture, and strategies of locomotion were formulated. The hind limb of Santacrucian sloths bears strong resemblances to that of living South American anteaters in stoutness of skeletal elements, form of the characteristics related to muscular and ligamentous attachments, and conservative, pentadactylous strong-clawed pes. The musculature was very well developed, allowing powerful forces, principally in entire limb adduction, crus flexion and extension, pes extension, and toe prehension. These functional features, together with those of the forelimb, are congruent with climbing behavior, and support the hypothesis that Santacrucian sloths were good but slow climbing mammals. However, their climbing strategies were limited, owing principally to their comparatively large body size, and they relied to a large extent on their powerful musculature and curved manual and pedal unguals for both moving and standing on the arboreal supports.

  15. New records of late Holocene tephras from Lake Futalaufquen (42.8°S), northern Patagonia

    NASA Astrophysics Data System (ADS)

    Daga, Romina; Ribeiro Guevara, Sergio; Arribére, María

    2016-03-01

    In regions with limited knowledge of the historical volcanic record, like remote areas in the Andean Southern Volcanic Zone, the definition of reliable age-depth models for lake sequences represents a valuable tool for tephra layers dating. In Lake Futalaufquen (42.8°S), Northern Patagonia, a short sedimentary sequence was extracted after the AD 2008 Chaitén eruption with the purpose to analyze the records of volcanic eruptions at these poorly studied latitudes. The sequence was dated by 210Pb, 137Cs, and 14C techniques. Five tephras were identified for the last 1600 years, restricted to the last 5 centuries. Sedimentology, morphology, and geochemical properties allowed the characterization of the tephras and their correlation with tephras recently identified proximal to the sources, mainly from Chaitén and Huequi volcanoes, and Michinmahuida accessory cones, representing the first distal records reported of these tephras. Furthermore, tephras modeled ages obtained by the sequence age-depth model shrink the ages for the volcanic events, like a potential cycle of activity from Michinmauida accessory cones during AD 1530 ± 55, one eruption from Huequi volcano at AD 1695 ± 50, and a possible recent eruption from Chaitén at AD 1775 ± 40. Additionally, the work contributes to improve the regional volcanic records knowledge, basic for volcanic hazard assessment.

  16. Status of the names of some hydroid species (Cnidaria, Hydrozoa), described from the Atlantic coast of Patagonia.

    PubMed

    Miranda, Thaís P; Cunha, Amanda F; Marques, Antonio C

    2016-09-29

    Thirty new species of benthic leptothecate hydroids were described and named from Patagonia in a 1991 PhD dissertation by Mohamed El Beshbeeshy. Although constituting nomina nuda under provisions of the International Code of Zoological Nomenclature (ICZN), the names of some species were used in several scientific publications between 1991 and 2011. In 2011, the dissertation of El Beshbeeshy was published in accordance with Article 8 of the ICZN. Several species-group names appearing in that work nevertheless fail to fully comply with certain articles of the code. The goal of this contribution is to review the nomenclatural availability of the names of those 30 new taxa, and to clearly establish the current status of El Beshbeeshy's material. Two of them were made available in 1999 as part of studies other than those of El Beshbeeshy, and correct authorship and date is here noted. Twenty-one of the nomina nuda were made available in a work published by El Beshbeeshy in 2011, although some constitute junior synonyms. Six of the new species-group names appearing in both the 1991 and 2011 works, established following a literature review of Patagonian species, were proposed without re-description, or designation of name-bearing types, or locations of such types. Most of them do not meet criteria of availability and remain nomina nuda. The status of each is discussed to avoid additional nomenclatural errors and continued taxonomic confusion.

  17. The flooding of the San Matías Gulf: The Northern Patagonia sea-level curve

    NASA Astrophysics Data System (ADS)

    Isla, Federico Ignacio

    2013-12-01

    Northern Patagonia is characterised by tectonic depressions below present sea level. Some of them are today flooded by the sea; others remain emerged although they are at altitudes of - 50 m (Bajo del Gualicho), - 35 m (Salinas Grandes) and - 7 m (Salina La Piedra). San Matías Gulf also was such an emerged depression below contemporary mean sea level during the Late Pleistocene. It flooded between 11,500 and 11,000 years ago, when the sea level surpassed the sill of the gulf (today 50 m below mean sea level) during postglacial sea-level rise. In those days, shrublands extended on the slopes of the tectonic depression. In-situ pieces of woods dredged from the bottom of the gulf at depths of 70 m gave a conventional age of 11,310 ± 150 years BP. We used the wood, together with dated shells from the continental shelf, and shells and organic matter dated from the San Blas, Negro and Chubut coastal plains to construct a sea-level curve. Sea level rise surpassed the present level somewhat before 6000 years BP, reaching a maximum stand of + 6 m. It has since gently diminished towards present sea level.

  18. Differential use of the Argentine shelf by wintering adults and juveniles southern giant petrels, Macronectes giganteus, from Patagonia

    NASA Astrophysics Data System (ADS)

    Blanco, Gabriela S.; Quintana, Flavio

    2014-08-01

    To study habitat use and at-sea movements of southern giant petrels (SGP) during non-breeding period, we deployed 15 satellite transmitters (six adults, nine juveniles) at Isla Arce and Isla Gran Robredo colonies in Patagonia, Argentina. Birds were instrumented during 81.4 ± 37 days. Adult birds used 74% of the Argentine shelf concentrating mainly at the shelf break, middle shelf waters, and the surroundings of the colony. After fledging, juveniles spread to the Argentine, Uruguayan and Brazilian shelves within the South Atlantic. Adults alternated at-sea excursions (12 ± 5 days) with periods at the colony of 3 ± 0.3 days. Contrarily, juveniles moved first to the shelf break and then traveled northwards reaching the south of Brazil. There was some spatial overlap between age classes, but only during the first 30 days after juveniles had fledged; thereafter there was not overlap between the areas used by both age classes. The Argentine shelf is widely used by different species offering a suitable environment for foraging; this may be why adults SGP from Patagonian colonies spend all year-round within the Argentine shelf. The identification of used areas of non-breeding SGP fills a gap in the species knowledge contributing not only to the preservation the species, but also to the management of marine areas globally recognized as important for many other Procellariiformes.

  19. Modeling volcanic ash resuspension - application to the 14-18 October 2011 outbreak episode in Central Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Folch, A.; Mingari, L.; Osores, M. S.; Collini, E.

    2013-09-01

    Volcanic fallout deposits from the June 2011 Cordón Caulle eruption in Central Patagonia were remobilized in several occasions months after their emplacement. In particular, during 14-18 October 2011, an intense outbreak episode generated huge volcanic clouds that were dispersed across Argentina, causing multiple impacts in the environment, affecting the air quality and disrupting airports. Fine ash particles in volcanic fallout deposits can be resuspended under favourable meteorological conditions, particularly during strong wind episodes in arid environments having low soil moisture and poor vegetation coverage. In opposition to eruption-formed ash clouds, modeling of resuspension-formed ash clouds has received little attention. In consequence, there are no emission schemes specially developed and calibrated for volcanic ash, and no operational product exists to model and forecast the formation and dispersal of resuspension ash clouds. Here we implement three dust emission schemes of increasing complexity in the FALL3D tephra dispersal model and use the 14-18 October 2011 outbreak episode as a model test case. We calibrate the emission schemes and validate the results of the coupled WRF-ARW/FALL3D modeling system using satellite imagery and measurements of visibility (a quantity related to total suspended particle concentration at surface) and particulate matter (PM10) concentration at several meteorological and air quality stations sparse across Argentina and Uruguay. Our final goal is to test the capability of the modeling system to become, in the near future, an operational forecast product for volcanic ash resuspension events.

  20. Utility of high-altitude infrared spectral data in mineral exploration: Application to Northern Patagonia Mountains, Arizona

    USGS Publications Warehouse

    Berger, B.R.; King, T.V.V.; Morath, L.C.; Phillips, J.D.

    2003-01-01

    Synoptic views of hydrothermal alteration assemblages are of considerable utility in regional-scale minerals exploration. Recent advances in data acquisition and analysis technologies have greatly enhanced the usefulness of remotely sensed imaging spectroscopy for reliable alteration mineral assemblages mapping. Using NASA's Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, this study mapped large areas of advanced argillic and phyllic-argillic alteration assemblages in the southeastern Santa Rita and northern Patagonia mountains, Arizona. Two concealed porphyry copper deposits have been identified during past exploration, the Red Mountain and Sunnyside deposits, and related published hydrothermal alteration zoning studies allow the comparison of the results obtained from AVIRIS data to the more traditional field mapping approaches. The AVIRIS mapping compares favorably with field-based studies. An analysis of iron-bearing oxide minerals above a concealed supergene chalcocite deposit at Red Mountain also indicates that remotely sensed data can be of value in the interpretation of leached caps above porphyry copper deposits. In conjunction with other types of geophysical data, AVIRIS mineral maps can be used to discriminate different exploration targets within a region.

  1. Gelidivirgula Patagoniensis Gen. Nov., Sp. Nov., A Novel Psychrotolerant, Sporeforming Anaerobe Isolated from Magellanic Penguin Guano in Patagonia, Chile

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.; Marsic, Damien; Whitman, William B.; Tang, Jane; Krader, Paul

    2003-01-01

    A novel obligately anaerobic, psychrotrophic bacterium, strain PPP2(sup T), was isolated from guano of the Magellanic penguin (Spheniscus magellanicus) in Patagonia, Chile. The Gram-positive, sporeforming, straight rods with sizes 0.6-0.9 x 3.0-5.0 microns, are motile by peritrichous flagella. Growth was observed to occur within the pH range 6.0-9.5 (optimum pH x), and temperature range 2-28 C (optimum 20 C). The novel isolate does not require NaCl for growth, but is halotolerant and growth was observed between 0 and 7 % NaCl (w/v) with optimum at 0.5 % (w/v). The new isolate is a catalase negative chemoorganohetherotroph with fermentative metabolism and uses as substrates: peptone, Bacto-tryptone, Casamino acids, and yeast extract. The major metabolic products are: acetate, butyrate, ethanol, and hydrogen is a minor gas product.. Strain PPP2 was sensitive to ampicillin, tetracycline, chloramphenicol, rifampin, kanamycin, and gentamycin. The G+C content of the DNA is 43.6 mol%. On the basis of 16S rDNA gene sequences and phenotypic characteristics, it is proposed that the strain PPP2(sup T) (= ATCC BAA-755(sup T) = JSM ...(sup T)) is assigned to the new genus Gelidivirgula gen. nov., as a representative of the new species, Gelidivirgula patagonensis sp. nov.

  2. Neighborhood effects on seed dispersal by frugivores: testing theory with a mistletoe-marsupial system in Patagonia.

    PubMed

    Morales, Juan Manuel; Rivarola, María Daniela; Amico, Guillermo; Carlo, Tomás A

    2012-04-01

    The outcome of the dispersal process in zoochorous plants is largely determined by the behavior of frugivorous animals. Recent simulation studies have found that fruit removal rates and mean dispersal distances are strongly affected by fruiting plant neighborhoods. We empirically tested the effects of conspecific fruiting plant neighborhoods, crop sizes, and plant accessibility on fruit removal rates and seed dispersal distances of a mistletoe species exclusively dispersed by an arboreal marsupial in Northern Patagonia. Moreover, in this study, we overcome technical limitations in the empirical estimation of seed dispersal by using a novel 15N stable isotope enrichment technique together with Bayesian mixing models that allowed us to identify dispersed seeds from focal plants without the need of extensive genotyping. We found that, as predicted by theory, plants in denser neighborhoods had greater fruit removal and shorter mean dispersal distances than more isolated plants. Furthermore, the probability of dispersing seeds farther away decreased with neighborhood density. Larger crop sizes resulted in larger fruit removal rates and smaller probabilities of longer distance dispersal. The interplay between frugivore behavioral decisions and the spatial distribution of plants could have important consequences for plant spatial dynamics.

  3. Echoes of a distant time: effects of historical processes on contemporary genetic patterns in Galaxias platei in Patagonia.

    PubMed

    Vera-Escalona, Iván; Habit, Evelyn; Ruzzante, Daniel E

    2015-08-01

    Interpreting the genetic structure of a metapopulation as the outcome of gene flow over a variety of timescales is essential for the proper understanding of how changes in landscape affect biological connectivity. Here we contrast historical and contemporary connectivity in two metapopulations of the freshwater fish Galaxias platei in northern and southernmost Patagonia where paleolakes existed during the Holocene and Pleistocene, respectively. Contemporary gene flow was mostly high and asymmetrical in the northern system while extremely reduced in the southernmost system. Historical migration patterns were high and symmetric in the northern system and high and largely asymmetric in the southern system. Both systems showed a moderate structure with a clear pattern of isolation by distance (IBD). Effective population sizes were smaller in populations with low contemporary gene flow. An approximate Bayesian computation (ABC) approach suggests a late Holocene colonization of the lakes in the northern system and recent divergence of the populations from refugial populations from east and west of the Andes. For the southern system, the ABC approach reveals that some of the extant G. platei populations most likely derive from an ancestral population inhabiting a large Pleistocene paleolake while the rest derive from a higher-altitude lake. Our results suggest that neither historical nor contemporary processes individually fully explain the observed structure and geneflow patterns and both are necessary for a proper understanding of the factors that affect diversity and its distribution. Our study highlights the importance of a temporal perspective on connectivity to analyse the diversity of spatially complex metapopulations.

  4. Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

    PubMed

    Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

    2016-09-01

    Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

  5. The glacial geomorphology of the Lago Buenos Aires and Lago Puerreydón ice lobes, Central Patagonia

    NASA Astrophysics Data System (ADS)

    Bendle, Jacob; Thorndycraft, Varyl; Palmer, Adrian

    2016-04-01

    Patagonia is ideally located for reconstructions of late Quaternary ice-climate interaction(s) in the Southern Hemisphere mid-latitudes, yet many questions remain concerning post-LGM ice sheet retreat dynamics across the region. While modern-day glaciation is restricted to three small icefields (the North and South Patagonian and Cordillera Darwin icefields), during the Quaternary, and at the LGM, episodes of significant ice advance culminated in an expansive Patagonian ice sheet (PIS) centered over the southern Andes, for which a long and well-preserved landform record exists. Previous mapping in the region has either aimed to achieve regional coverage, necessarily omitting more subtle/complex features suggestive of certain ice-marginal processes, or has focused on the identification of palaeo-ice limits (e.g. moraine ridges) for geochronological applications, with little attention given to other (e.g. glaciofluvial, glaciolacustrine) features that are significant for understanding post-LGM ice sheet retreat dynamics. This poster presents a comprehensive and highly detailed (<30m spatial resolution) map of the glacial geomorphology of the Lago Buenos Aires (46.4°S) and Lago Puerreydón (47.2°S) ice lobes, major outlet glaciers of the central sector of the former PIS. The map allows refined reconstructions of glacial and, in particular, deglacial ice-marginal processes, and will underpin further analysis on the retreat history of the palaeo-ice lobes using high-resolution lithostratigraphic (varve) analyses.

  6. Early formation of gnammas (weathering pits) in a recently glaciated area of Torres del Paine, southern Patagonia (Chile)

    NASA Astrophysics Data System (ADS)

    Domínguez-Villar, David

    2006-06-01

    Incipient gnammas (weathering pits) were identified and measured in the Francés Valley of Torres del Paine, southern Patagonia. The gnammas were located on the granite blocks of a lateral moraine deposited during a Late Holocene neoglacial advance. The gnammas were measured for maximum and minimum depth, length, and width in addition to other observations. Based on these measurements, the surface area and the volume of the gnammas were calculated. Most of the gnammas have < 1 L of rock volume eroded, and the maximum depth is always < 10 cm. The gnammas do not develop erosional spillways. A high correlation exists between maximum and minimum depths, indicating these values are not completely independent. Thus, the depth ratio has been used to characterize the gnammas for discrete locations. The gnammas from Francés Valley belong to a unique normal population and a δ-value based on the depth ratio was defined to represent this population. The δ of Francés Valley is 1.33 ± 0.07, comparable with the lowest values of other stations around the globe. I suggest that the δ-value could be used as an indicator of gnamma evolution.

  7. Niger River

    Atmospheric Science Data Center

    2013-04-15

    ... third largest river in Africa, the Niger, forms an inland delta in central Mali. This Multi-angle Imaging SpectroRadiometer (MISR) image ... the region as it appears after the rainy season, when the delta is flooded. The image covers an area measuring about 400 kilometers x 450 ...

  8. Mississippi River

    Atmospheric Science Data Center

    2014-05-15

    ... to melt and the Wapsipinicon River was 52 centimeters above flood stage at De Witt, Iowa (between Clinton and Davenport). By mid-April ... slightly below the level reached in the record-setting flood of 1993. MISR was built and is managed by NASA's Jet Propulsion ...

  9. 75 FR 4340 - Plan Revision for the Coronado National Forest, Cochise, Graham, Pima, Pinal, and Santa Cruz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... management direction for fire, caves, cultural resources, roads, and trails, and adding direction for the... also make new special area recommendations for wilderness, wild and scenic rivers, research natural... habitat conservation, fire ecology, hazardous fuels reduction, and current ecological threats,...

  10. Richness of plant-insect associations in Eocene Patagonia: a legacy for South American biodiversity.

    PubMed

    Wilf, Peter; Labandeira, Conrad C; Johnson, Kirk R; Cúneo, N Rubén

    2005-06-21

    South America has some of the most diverse floras and insect faunas that are known, but its Cenozoic fossil record of insects and insect herbivory is sparse. We quantified insect feeding on 3,599 leaves from the speciose Laguna del Hunco flora (Chubut, Argentina), which dates to the early Eocene climatic optimum (52 million years ago) and compared the results with three well preserved, rich, and identically analyzed early- and middle-Eocene floras from the following sites in North America: Republic, WA; Green River, UT; and Sourdough, WY. We found significantly more damage diversity at Laguna del Hunco than in the North American floras, whether measured on bulk collections or on individual plant species, for both damage morphotypes and feeding groups. An ancient history of rich, specialized plant-insect associations on diverse plant lineages in warm climates may be a major factor contributing to the current biodiversity of South America.

  11. 33 CFR 162.90 - White River, Arkansas Post Canal, Arkansas River, and Verdigris River between Mississippi River...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Arkansas River, and Verdigris River between Mississippi River, Ark., and Catoosa, Okla.; use... White River, Arkansas Post Canal, Arkansas River, and Verdigris River between Mississippi River, Ark... apply to: (1) Waterways. White River between Mississippi River and Arkansas Post Canal, Ark.;...

  12. A new genus and species of isanthid sea anemone (Cnidaria: Anthozoa: Actiniaria) from Chilean Patagonia, Anthoparactis fossii n. gen. et sp

    NASA Astrophysics Data System (ADS)

    Häussermann, Verena; Rodríguez, Estefanía

    2014-09-01

    We describe a new genus and species of sea anemone from Chilean Patagonia. Anthoparactis fossii n. gen. et sp. adds another acontiate genus and species to the family Isanthidae Carlgren, 1938. Anthoparactis n. gen. differs from the other isanthid genera in having the same number of mesenteries distally and proximally, acontia with basitrichs only, and a column with verrucae distally. Anthoparactis fossii n. sp. differs from the most similar species, Isoparactis fionae Lauretta et al., 2013, in the number of cycles of mesenteries and tentacles, structures of the column, colour pattern of the oral disc, cnidae, and geographical distribution. Isanthidae now includes seven genera and 11 species.

  13. Analysis of methods to determine storage capacity of, and sedimentation in, Loch Lomond Reservoir, Santa Cruz County, California, 2009

    USGS Publications Warehouse

    McPherson, Kelly R.; Freeman, Lawrence A.; Flint, Lorraine E.

    2011-01-01

    In 2009, the U.S. Geological Survey, in cooperation with the City of Santa Cruz, conducted bathymetric and topographic surveys to determine the water storage capacity of, and the loss of capacity owing to sedimentation in, Loch Lomond Reservoir in Santa Cruz County, California. The topographic survey was done as a supplement to the bathymetric survey to obtain information about temporal changes in the upper reach of the reservoir where the water is shallow or the reservoir may be dry, as well as to obtain information about shoreline changes throughout the reservoir. Results of a combined bathymetric and topographic survey using a new, state-of-the-art method with advanced instrument technology indicate that the maximum storage capacity of the reservoir at the spillway altitude of 577.5 feet (National Geodetic Vertical Datum of 1929) was 8,646 ±85 acre-feet in March 2009, with a confidence level of 99 percent. This new method is a combination of bathymetric scanning using multibeam-sidescan sonar, and topographic surveying using laser scanning (LiDAR), which produced a 1.64-foot-resolution grid with altitudes to 0.3-foot resolution and an estimate of total water storage capacity at a 99-percent confidence level. Because the volume of sedimentation in a reservoir is considered equal to the decrease in water-storage capacity, sedimentation in Loch Lomond Reservoir was determined by estimating the change in storage capacity by comparing the reservoir bed surface defined in the March 2009 survey with a revision of the reservoir bed surface determined in a previous investigation in November 1998. This revised reservoir-bed surface was defined by combining altitude data from the 1998 survey with new data collected during the current (2009) investigation to fill gaps in the 1998 data. Limitations that determine the accuracy of estimates of changes in the volume of sedimentation from that estimated in each of the four previous investigations (1960, 1971, 1982, and 1998

  14. Use of remotely sensed imagery to map Sudden Oak Death (Phytophthora ramorum) in the Santa Cruz Mountains

    NASA Astrophysics Data System (ADS)

    Gillis, Trinka

    This project sought a method to map Sudden Oak Death distribution in the Santa Cruz Mountains of California, a coastal mountain range and one of the locations where this disease was first observed. The project researched a method to identify forest affected by SOD using 30 m multi-spectral Landsat satellite imagery to classify tree mortality at the canopy-level throughout the study area, and applied that method to a time series of data to show pattern of spread. A successful methodology would be of interest to scientists trying to identify areas which escaped disease contagion, environmentalists attempting to quantify damage, and land managers evaluating the health of their forests. The more we can learn about the disease, the more chance we have to prevent further spread and damage to existing wild lands. The primary data source for this research was springtime Landsat Climate Data Record surface reflectance data. Non-forest areas were masked out using data produced by the National Land Cover Database and supplemental land cover classification from the Landsat 2011 Climate Data Record image. Areas with other known causes of tree death, as identified by Fire and Resource Assessment Program fire perimeter polygons, and US Department of Agriculture Forest Health Monitoring Program Aerial Detection Survey polygons, were also masked out. Within the remaining forested study area, manually-created points were classified based on the land cover contained by the corresponding Landsat 2011 pixel. These were used to extract value ranges from the Landsat bands and calculated vegetation indices. The range and index which best differentiated healthy from dead trees, SWIR/NIR, was applied to each Landsat scene in the time series to map tree mortality. Results Validation Points, classified using Google Earth high-resolution aerial imagery, were created to evaluate the accuracy of the mapping methodology for the 2011 data.

  15. Investigating tree mortality at multiple spatial and temporal scales in the Bishop pine forest on Santa Cruz Island, California

    NASA Astrophysics Data System (ADS)

    Baguskas, S. A.; Bookhagen, B.; Peterson, S. H.; Asner, G. P.

    2010-12-01

    The rate of tree mortality has increased across the western United States in recent decades, and many studies attribute the cause to water stress induced by regional warming. To date, the geographical scope of study regions affected by widespread tree mortality in the American West has largely been limited to continental, montane climates. Much less is known about mortality events in other climatic regions, such as coastal forests. The relatively unvarying nature of the coastal, maritime climate has traditionally been assumed to buffer these forests from large climate variations; however, we have observed rapid tree mortality in this region which suggests coastal forests may be as susceptible to drought-induced mortality as inland forest locations. Santa Cruz Island (SCI), one of the California Channel Islands, harbors numerous relict and endemic plant species, including Bishop pine (Pinus muricata). Following extreme drought in southern California in two of the last three years (2007-2009), widespread mortality of Bishop pines has become evident. Bishop pine populations are restricted to the fog belt of coastal California and northern Baja California; therefore, a major reduction of existing populations on SCI would greatly reduce the distribution of the species as a whole. The focus of my research is to investigate the mechanisms underlying spatial and temporal patterns of Bishop pine mortality on SCI. I used remote sensing techniques to characterize spatiotemporal patterns of tree mortality and I have performed ground-data collection to validate remote-sensing results. Remote sensing in combination with field verification is a valuable tool to understand the spatiotemporal pattern of tree mortality and is a necessary step to help elucidate potential environmental and biological controls on tree mortality.

  16. Rabies-vaccination coverage and profiles of the owned-dog population in Santa Cruz de la Sierra, Bolivia.

    PubMed

    Suzuki, K; Pereira, J A C; Frías, L A; López, R; Mutinelli, L E; Pons, E R

    2008-05-01

    The Bolivian government issued a regulation for rabies control in November 2005, owing to increasing the prevalence of dog and human rabies cases in recent years. An assessment of rabies-vaccination coverage and other factors that might influence the success of the on-going vaccination campaign was needed. The objective of this study was to investigate dog rabies vaccination coverage and risk factors associated with dogs being unvaccinated against rabies, and profiles of the owned-dog population in Santa Cruz de la Sierra, Bolivia, where dog rabies was endemic. Mainly due to logistical reasons, the WHO's expanded programme on immunization cluster-survey method was used. The 390 households were included in the study. Information about dog population and management characteristics was obtained for 542 dogs from 301 households. On average, households had 1.4 dogs and 1.8 dogs per dog-owning household (median = 1). The human-to-dog ratio was 4.6 : 1. During the last 1 year prior to the study, of the 539 dogs aged >or=1 month, 463 (85%; 95% CI 79-91; design effect 3.6) were classified as vaccinated. Amongst the study dogs, dogs aged 1-11 months were the higher risk of dogs not being vaccinated (OR = 8.2; 95% CI 4.3-15.6; P < 0.01). Almost two-thirds of the study dogs were allowed to roam freely throughout the day or in part. Community education efforts should address the importance of dog ownership and movement restriction, and the need to vaccinate young dogs.

  17. Earthquake Recurrence and Deformation in the Last Four Events on the Santa Cruz Mountains Section of the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Streig, A. R.; Dawson, T. E.; Weldon, R. J.

    2012-12-01

    Paleoseismic investigations at the Hazel Dell site on the Santa Cruz Mountains section (SAS) of the San Andreas fault has yielded evidence of four earthquakes. We present evidence of the 1906 surface rupture (E1), and 3 earlier events, including new evidence for two 1800's earthquakes. Evidence for the penultimate event, E2, is expressed as upward fault terminations within a massive sand infilling a topographic low. This sand infilled a depression formed by the pre-penultimate earthquake, E3. We identified axe-cut wood stratigraphically below the pre-penultimate earthquake horizon, which suggests that surface rupturing earthquakes E2 and E3 occurred after deposition of the cut wood stratigraphic unit. Lumber harvesting began in the area around 1832, and new radiocarbon dates sampled from redwood growth rings demonstrate that earthquakes E2 and E3 are historical. E4 occurred between A.D. 1651 and 1497. These new event data for the SAS suggest more frequent surface rupturing earthquakes within historical time than previously recognized. The data require at least two modes of behavior in strain release on the SAS through time. One mode of strain release, is through large multi-segment earthquakes; the 1906 event was a large multi-segment earthquake that dominates the moment budget of the fault. During the period prior to 1906, analysis of the historic record suggests that the SAS was characterized by a second mode of moderate seismicity, with six M≥ 6 earthquakes between 1838 and 1890 (Bakun, 1999), all located along the southern half of the segment near the Hazel Dell study area. The two 1800's earthquakes identified in this study support this second mode of moderate seismicity on the SAS.

  18. Density and reproduction of the Queen Conch EUSTROMBUS gigas (Mesogastropoda: Strombidae) at Cabo Cruz, Desembarco del Granma National Park, Cuba.

    PubMed

    Cala, Yuself R; de Jesús-Navarrete, Alberto; Ocaña, Frank A; Oliva-Rivera, José

    2013-06-01

    The queen conch Eustrombus gigas is an important fisheries resource in the Caribbean region. In Cuba Island the studies about this resource are very scarce and particularly in the Southeastern regions of the country. With the aim to get important fishery information about this gastropod, adult Queen Conch density and frequency of reproductive activity were evaluated in Cabo Cruz, Cuba, during 2009-2010. Data from three seasons were obtained (rainy, dry and cold fronts periods) from three different areas: Farito, Guafe and Laguna. The highest density was observed in cold fronts season (468.5 ind./ha) and the lowest occurred during the dry season (268.5 ind./ha). The highest density was reported at Laguna (520.4 ind./ha) and the lowest at Farito (290.9ind./ha). In total, 158 reproductive events were observed. The highest frequency was reported in rainy season (36%), followed by dry (9%) and cold fronts (5%) seasons. Reproductive behavior (mating and egg laying) was related to temperature and photoperiod. Reproductive activity was observed during the whole year, which suggests the existence of an important Queen Conch reserve in the Southeastern region of Cuba and an apparently self-sufficient population for recruitment. From our results we may conclude that, the population's sustainable exploitation is viable if the following management measures are observed: functional zoning within the area, rotation of fishing areas and a closed season. We recommend that the Laguna site should be protected as a reproduction zone and banned for fishing activities.

  19. Using dye tracing to establish groundwater flow paths in a limestone marble aquifer, University of California, Santa Cruz, California

    SciTech Connect

    Hayes, J.; Bertschinger, V. ); Aley, T. )

    1993-04-01

    Areas underlain by karst aquifers are characterized by soluble rock with sinkholes, caves, and a complex underground drainage network. Groundwater issues such as flow direction, well pumping impacts, spring recharge areas, and potential contamination transport routes are greatly complicated by the unique structure of karst aquifers. Standard aquifer analysis techniques cannot be applied unless the structure of the karst aquifer is understood. Water soluble fluorescent dyes are a powerful tool for mapping the irregular subsurface connections and flow paths in karst aquifers. Mapping the subsurface connections allows reasonable estimates of the hydrologic behavior of the aquifer. Two different fluorescent dyes were injected at two points in a limestone karst aquifer system beneath the University of California, Santa Cruz campus. Flow paths in the marble were thought to be closely tied to easily recognized geomorphic alignments of sinkholes associated with fault and fracture zones. The dye tests revealed unexpected and highly complex interconnections. These complex flow paths only partially corresponded to previous surface mapping and aerial photo analysis of fracture systems. Several interfingering but hydrologically unconnected flow paths evidently exist within the cavernous aquifer. For example, dye did not appear at some discharge springs close to the dye injection points, but did appear at more distant springs. This study shows how a dye tracing study in a small, well-defined limestone body can shed light on a variety of environmental and hydrological issues, including potential well pumping impact areas, wellhead protection and recharge areas, parking lot runoff injection to aquifers, and drainage routes from hazardous materials storage areas.

  20. Controls on volatile content and distribution in the continental upper mantle of Southern Gondwana (Patagonia & W. Antarctica)

    NASA Astrophysics Data System (ADS)

    Rooks, Eve; Gibson, Sally; Petrone, Chiara; Leat, Phillip

    2015-04-01

    Water content is known to affect many physical and chemical properties of the upper mantle, including melting temperature and viscosity. Water is hosted by hydrous phases, such as amphibole and phlogopite, and also by more dominant, nominally-anhydrous mantle minerals (e.g. olivine and pyroxene). The latter have the potential to incorporate hundreds of ppm of water in point defects, and may explain geophysical observations such as seismic and conductivity anomalies in the upper mantle [1]. However, the significance of the reported concentrations of H2O in nominally anhydrous minerals in mantle xenoliths is still a subject of debate primarily due to the effects of post-entrainment loss [1,2]. Unlike H2O and Li, F is less susceptible to post entrainment loss and can potentially be used to constrain the source of volatiles. We present high-precision SIMS analyses of H2O, Li and F in mantle xenoliths hosted by recently-erupted (5-10 Ka) alkali basalts from south Patagonia and the Antarctic Peninsula. These two regions formed part of the southern margin of the Gondwana supercontinent, prior to break-up, and were located above long-lived subduction zones for at least 200 M.yr., making them highly-appropriate to investigating long term evolution of the sub-continental lithospheric mantle in this setting. The xenoliths are well characterised peridotites, sourced from the off-craton spinel- and spinel-garnet facies lithospheric mantle (40-80 km). Samples are relatively dry: H2O contents of olivine span 0-49 ppm, orthopyroxene 150-235 ppm and clinopyroxene 100-395 ppm. West Antarctic samples are more hydrated than Patagonian samples, on average. These H2O concentrations fall within the global measured range for off-craton mantle minerals [4]. We attribute low H2O concentrations in olivine to diffusive loss, either by exchange with the host magma, shallow level degassing or during cooling [2]. F shows less variability than H2O and is most highly concentrated in clinopyroxenes

  1. Earthquake travel time tomography of the southern Santa Cruz Mountains: Control of fault rupture by lithological heterogeneity of the San Andreas fault zone

    SciTech Connect

    Foxall, W.; Michelini, A.; McEvilly, T.V.

    1993-10-10

    The 1989 Loma Prieta earthquake occurred along the stretch of the San Andreas fault zone within the southern Santa Cruz Mountains that last failed as a major earthquake in 1906. The southeastern end of the 1989 rupture marks the transition from stable, aseismic slip on the central creeping section of the San Andreas fault to unstable failure on the locked 1906 segment. The authors investigate this transition and the rupture characteristics of the 1989 earthquake using a 3-D P wave velocity model of the southern Santa Cruz Mountains section of the fault zone. The model images a large anomalous high-velocity body at midcrustal depths within the rupture zone of the 1989 earthquake that the available evidence suggests might have gabbroic or other mafic composition. On the basis of the relationship of the lithological features interpreted from the velocity model to the seismicity and surface creep the authors propose a model in which the high-velocity body is primarily responsible for the transition from stable to unstable fault slip at Pajaro Gap. The active plane of the San Andreas fault cuts throughout the body. The fault system attempts to circumvent this barrier by transferring slip to secondary faults, including splay faults that have propagated along the frictionally favorable contact between the high-velocity rock mass and Franciscan country rocks. However, the near arrest of the stable sliding causes stress to concentrate within the body, and the high-strength, unstable contact within it evolves from a barrier to the asperity that failed in the 1989 earthquake. The general features of the 1989 rupture predicted by this asperity model agree with several rupture histories computed for the earthquake. The model implies that as proposed by other workers, the Loma Prieta earthquake did not involve a repeat of the 1906 slip, which has an important bearing on earthquake recurrence estimates for the Santa Cruz Mountains segment of the fault. 114 refs., 11 figs.

  2. Multi-stemmed trees of Nothofagus pumilio second-growth forest in Patagonia are formed by highly related individuals

    PubMed Central

    Till-Bottraud, Irène; Fajardo, Alex; Rioux, Delphine

    2012-01-01

    Background and Aims Multi-stemmed trees (tree clusters) in Nothofagus pumilio, a dominant tree species in Patagonia, are very uncommon and are restricted to the edge of second-growth forests following human-provoked fires. No vegetative reproduction has been reported so far. The genetic structure of multi-stemmed trees of this species was investigated and it was hypothesized that genets within a cluster were more closely related than average in the population. Methods Fifteen clusters (composed of at least three purported stems) and 15 single trees were sampled at the edge of a second-growth forest and genotyped using two amplified fragment length polymorphism (AFLP) primer pairs. We obtained 119 polymorphic markers that allowed clonality to be determined, together with sibship structure and relatedness among samples. Key Results Clonality was detected in seven clusters but all clusters had at least two different genotypes. Full sibs were found exclusively within clusters and in all clusters. Within a cluster, stems that were not identified as full sibs were often half sibs. Relatedness values for the full sibs and half sibs were higher than the theoretical values of 0·5 and 0·25 but the relatedness between clusters was very low. Conclusions Tree clusters that are merged at the edge of the second-growth forest of N. pumilio are composed of stems of the same genotype and of other genotypes that are highly related (but not always). It is suggested that this peculiar genetic structure results from a combination of several causes, including selection for merging of related individuals. PMID:22782238

  3. Exploring the Diversity and Antimicrobial Potential of Marine Actinobacteria from the Comau Fjord in Northern Patagonia, Chile

    PubMed Central

    Undabarrena, Agustina; Beltrametti, Fabrizio; Claverías, Fernanda P.; González, Myriam; Moore, Edward R. B.; Seeger, Michael; Cámara, Beatriz

    2016-01-01

    Bioprospecting natural products in marine bacteria from fjord environments are attractive due to their unique geographical features. Although, Actinobacteria are well known for producing a myriad of bioactive compounds, investigations regarding fjord-derived marine Actinobacteria are scarce. In this study, the diversity and biotechnological potential of Actinobacteria isolated from marine sediments within the Comau fjord, in Northern Chilean Patagonia, were assessed by culture-based approaches. The 16S rRNA gene sequences revealed that members phylogenetically related to the Micrococcaceae, Dermabacteraceae, Brevibacteriaceae, Corynebacteriaceae, Microbacteriaceae, Dietziaceae, Nocardiaceae, and Streptomycetaceae families were present at the Comau fjord. A high diversity of cultivable Actinobacteria (10 genera) was retrieved by using only five different isolation media. Four isolates belonging to Arthrobacter, Brevibacterium, Corynebacterium and Kocuria genera showed 16S rRNA gene identity <98.7% suggesting that they are novel species. Physiological features such as salt tolerance, artificial sea water requirement, growth temperature, pigmentation and antimicrobial activity were evaluated. Arthrobacter, Brachybacterium, Curtobacterium, Rhodococcus, and Streptomyces isolates showed strong inhibition against both Gram-negative Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica and Gram-positive Staphylococcus aureus, Listeria monocytogenes. Antimicrobial activities in Brachybacterium, Curtobacterium, and Rhodococcus have been scarcely reported, suggesting that non-mycelial strains are a suitable source of bioactive compounds. In addition, all strains bear at least one of the biosynthetic genes coding for NRPS (91%), PKS I (18%), and PKS II (73%). Our results indicate that the Comau fjord is a promising source of novel Actinobacteria with biotechnological potential for producing biologically active compounds. PMID:27486455

  4. Trichococcus Patagoniensis sp. nov., a Facultative Anaerobe that grows at -5 C, Isolated from Penguin Guano in Chilean Patagonia

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.; Bej, Asim K.; Marsic, Damien; Whitman, William B.; Krader, Paul E.; Tang, Jane

    2006-01-01

    A novel, extremely psychrotolerant, facultative anaerobe, strain PmagGl(sup T), was isolated from guano of Magellanic penguins (Spheniscus magellanicus) collected in Chilean Patagonia. Gram-variable, motile cocci with a diameter of 1.3-2.0 micrometers were observed singularly or in pairs, short chains and irregular conglomerates. Growth occurred within the pH range 6.0-10.0, with optimum growth at pH 8.5. The temperature range for growth of the novel isolate was from -5 to 35 C, with optimum growth at 28-30 C. Strain PmagG1(sup T) did not require NaCl, as growth was observed in the presence of 0-6.5% NaCl with optimum growth at 0.5% (w/v). Strain PmagGl(sup T) was a catalase-negative chemo-organoheterotroph that used sugars and some organic acids as substrates. The metabolic end products were lactate, formate, acetate, ethanol and Con. Strain PmagG1(sup T) was sensitive to ampicillin, tetracycline, chloramphenicol, rifampicin, kanamycin and gentamicin. The G+C content of its genomic DNA was 45.8 mol%. 16S rRNA gene sequence analysis showed 100 % similarity of strain PmagG1(sup T) with Trichococcus collinsii ATCC BAA-296(sup T), but DNA-DNA hybridization between them demonstrated relatedness values of less than 45 plus or minus 1%. Another phylogenetically closely related species, Trichococcus pasteurii, showed 99.85 % similarity by 16s rRNA sequencing and DNA-DNA hybridization showed relatedness values of 47 plus or minus 1.5%. Based on genotypic and phenotypic characteristics, the novel species Trichococcus patagoniensis sp. nov. is proposed, with strain PmagG1(sup T) (=ATCC BAA-756(sup T)=JCM 12176(sup T)=CIP 108035(sup T)) as the type strain.

  5. Evaluation of neophobia and its potential impact upon predator control techniques: a study on two sympatric foxes in southern Patagonia.

    PubMed

    Travaini, Alejandro; Vassallo, Aldo Iván; García, Germán Oscar; Echeverría, Alejandra Isabel; Zapata, Sonia Cristina; Nielsen, Sigrid

    2013-01-01

    An alternative approach to increase the efficiency of predator control and selectivity is to consider the natural behavioural repertoire of the target species and how such behaviours may increase their vulnerability. Neophobia, or the hesitancy to approach a novel food item, object, or place, is an important factor influencing the investigative behaviour of animals, and its incorporation to predator control techniques may help to reduce losses of livestock to predators. In this study, we simultaneously evaluated the existence and intensity of neophobic responses in two sympatric fox species, the Culpeo (Pseudalopex culpaeus) and the Grey (P. griseus) foxes in southern Patagonia, Argentina. For this purpose, we used bait stations to compare fox behavioural responses in the absence (pre-treatment), presence (treatment) and removal (post-treatment) of a novel stimulus, which consisted of an orange PVC-traffic cone. Both fox species showed a neophobic response: bait-station visitation rates decreased (P=0.005 and P=0.048, for Culpeo and Grey foxes, respectively) in the presence of the novel object. The intensity of the response differed between species being higher for Culpeo foxes (approximately 80% of reduction in visitation rate during treatment for Culpeo foxes vs. 10% for Grey foxes). However, the bait-station visitation pattern after novel object removal indicated that animals probably increased exploration of the station. The high level of neophobia achieved by the Culpeo fox, together with an increase in post-treatment site exploration, suggests that behavioural manipulations (reduction of neophobia and its consequent increase in risk taking) could improve selective and efficient fox control in rural areas where livestock production is a major economic activity.

  6. Modeling volcanic ash resuspension - application to the 14-18 October 2011 outbreak episode in central Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Folch, A.; Mingari, L.; Osores, M. S.; Collini, E.

    2014-01-01

    Volcanic fallout deposits from the June 2011 Cordón Caulle eruption on central Patagonia were remobilized in several occasions months after their emplacement. In particular, during 14-18 October 2011, an intense outbreak episode generated widespread volcanic clouds that were dispersed across Argentina, causing multiple impacts in the environment, affecting the air quality and disrupting airports. Fine ash particles in volcanic fallout deposits can be resuspended under favorable meteorological conditions, particularly during strong wind episodes in arid environments with low soil moisture and poor vegetation coverage. As opposed to eruption-formed ash clouds, modeling of resuspension-formed ash clouds has received little attention. In consequence, there are no emission schemes specially developed and calibrated for resuspended volcanic ash, and few operational products exists to model and forecast the formation and dispersal of resuspension ash clouds. Here we implement three dust emission schemes of increasing complexity in the FALL3D tephra dispersal model and use the 14-18 October 2011 outbreak episode as a model test case. We calibrate the emission schemes and validate the results of the coupled WRF-ARW (Weather Research and Forecasting - Advanced Research WRF)/FALL3D modeling system using satellite imagery and measurements of visibility (a quantity related to total suspended particle concentration at the surface) and particulate matter (PM10) concentration at several meteorological and air quality stations located at Argentina and Uruguay. Our final goal is to test the capability of the modeling system to become, in the near future, an operational forecast product for volcanic ash resuspension events.

  7. Vulnerability to climate warming of Liolaemus pictus (Squamata, Liolaemidae), a lizard from the cold temperate climate in Patagonia, Argentina.

    PubMed

    Kubisch, Erika Leticia; Fernández, Jimena Beatriz; Ibargüengoytía, Nora Ruth

    2016-02-01

    The vulnerability of populations and species to global warming depends not only on the environmental temperatures, but also on the behavioral and physiological abilities to respond to these changes. In this sense, the knowledge of an organism's sensitivity to temperature variation is essential to predict potential responses to climate warming. In particular, it is interesting to know how close species are to their thermal limits in nature and whether physiological plasticity is a potential short-term response to warming climates. We exposed Liolaemus pictus lizards, from northern Patagonia, to either 21 or 31 °C for 30 days to compare the effects of these treatments on thermal sensitivity in 1 and 0.2 m runs, preferred body temperature (T pref), panting threshold (T pant), and critical minimum temperature (CTMin). Furthermore, we measured the availability of thermal microenvironments (operative temperatures; T e) to measure how close L. pictus is, in nature, to its optimal locomotor performance (T o) and thermal limits. L. pictus showed limited physiological plasticity, since the acclimation temperature (21 and 31 °C) did not affect the locomotor performance nor did it affect T pref, the T pant, or the CTMin. The mean T e was close to T o and was 17 °C lower than the CTMax. The results suggest that L. pictus, in a climate change scenario, could be vulnerable to the predicted temperature increment, as this species currently lives in an environment with temperatures close to their highest locomotor temperature threshold, and because they showed limited acclimation capacity to adjust to new thermal conditions by physiological plasticity. Nevertheless, L. pictus can run at 80 % or faster of its maximum speed across a wide range of temperatures near T o, an ability which would attenuate the impact of global warming.

  8. Source and trophic transfer of mercury in plankton from an ultraoligotrophic lacustrine system (Lake Nahuel Huapi, North Patagonia).

    PubMed

    Rizzo, Andrea; Arcagni, Marina; Campbell, Linda; Koron, Neža; Pavlin, Majda; Arribére, María A; Horvat, Milena; Guevara, Sergio Ribeiro

    2014-09-01

    The incorporation and trophic transfer of total and methyl mercury (THg, MeHg) were examined in three size classes of plankton (10-53, 53-200, and >200 μm size range) and a small planktivorous fish, Galaxias maculatus, from the large multi-branched Lake Nahuel Huapi (North Patagonia, Argentina). Three sites representing a large range of lake benthic-pelagic structures (based on depth and shoreline characteristics) and precipitation regimes were sampled. Nitrogen and carbon stable isotopes (δ(15)N, δ(13)C) were analyzed to assess Hg trophodynamics. Selenium concentrations were determined together with THg in order to consider its potential effect on Hg trophodynamics. High THg concentrations (0.1-255 µg g(-1) dry weight (DW)) were measured in plankton, largely in inorganic form (MeHg: 3-29 ng g(-1) DW, 0.02-7% of THg, in the two larger size classes). A trend of increasing THg concentrations, varying in two to three orders of magnitude, with decreasing plankton size was associated with precipitation measured prior to each sampling event. Passive adsorption of dissolved Hg(2+) from wet deposition and runoff is considered to be the principal Hg uptake mechanism at the base of the pelagic food web. Despite the initially high THg uptake in the smaller plankton classes, the transfer to G. maculatus, and consequently to the entire food web, is likely limited due to low proportion of MeHg to THg in plankton. Furthermore, evidence of G. maculatus with benthic feeding habits having higher impact on MeHg trophic transfer compared to the same species with more pelagic (e.g., zooplankton) feeding habits, was observed. Although there is a high THg uptake in plankton, limited amounts are incorporated in the entire food web from the pelagic compartment.

  9. Comparative study of the female gametogenic cycle in three populations of Buccinanops globulosus (Caenogastropoda: Nassariidae) from Patagonia

    NASA Astrophysics Data System (ADS)

    Avaca, María Soledad; Martín, Pablo; van der Molen, Silvina; Narvarte, Maite

    2015-03-01

    The populations of Buccinanops globulosus from three different sites of northern Patagonia were compared in the female reproductive cycle over a 2-year study period (September 2006-August 2008). These populations differed in demographic and life-history traits (sex ratios, size frequency distributions, growth rates and fecundity). Also, two of these populations show imposex-affected females (Bahía San Antonio, BSA and Bahía Nueva, BN), whereas the other (Playa Villarino, PV) is imposex-free and constitutes a commercial fishery ground for this species. The gametogenic activity of this species has not been studied earlier. Females showed the same gonadal stages in the three populations; however, there were differences in the female size at which each gonadal stage occurred. Monthly variation in gonadal stages and in oocyte size indicated that females of B. globulosus showed a seasonal gametogenic pattern without the occurrence of a resting period. Evacuation of mature oocytes (up to 252.5 µm) occurred mainly from September to December (austral spring) in BSA and PV and from December to March (austral summer) in BN. Gonad maturation and the presence of females carrying egg capsules in the field coincided with changes in water surface temperature and a longer day length. Our results indicate that the occurrence of imposex in the populations studied apparently does not affect the gametogenic activity in females. This study provides further insights into the reproductive biology of B. globulosus. The identification of population variation in reproductive traits should lead to more effective management of the species.

  10. Climate-driven terrestrial inputs in ultraoligotrophic mountain streams of Andean Patagonia revealed through chromophoric and fluorescent dissolved organic matter.

    PubMed

    Garcia, Roberto D; Reissig, Mariana; Queimaliños, Claudia P; Garcia, Patricia E; Dieguez, Maria C

    2015-07-15

    Fluvial networks transport a substantial fraction of the terrestrial production, contributing to the global carbon cycle and being shaped by hydrologic, natural and anthropogenic factors. In this investigation, four Andean Patagonian oligotrophic streams connecting a forested catchment (~125km(2)) and draining to a double-basin large and deep lake (Lake Moreno complex, Northwestern Patagonia), were surveyed to analyze the dynamics of the allochthonous subsidy. The results of a 30month survey showed that the catchment supplies nutrients and dissolved organic matter (DOM) to the streams. The eruption of the Puyehue-Cordón Caulle at the beginning of the study overlapped with seasonal precipitation events. The largest terrestrial input was timed with precipitation which increased particulate materials, nutrients and DOM through enhanced runoff. Baseline suspended solids and nutrients were very low in all the streams (suspended solids: ~1mg/L; total nitrogen: ~0.02mg/L; total phosphorus: ~5μg/L), increasing several fold with runoff. Baseline dissolved organic carbon concentrations (DOC) ranged between 0.15 and 1mg/L peaking up to three-fold. Chromophoric and fluorescent analyses characterized the DOM as of large molecular weight and high aromaticity. Parallel factor modeling (PARAFAC) of DOM fluorescence matrices revealed three components of terrestrial origin, with certain degree of microbial processing: C1 and C2 (terrestrial humic-like compounds) and C3 (protein-like and pigment derived compounds). Seasonal changes in MOD quality represent different breakdown stages of the allochthonous DOM. Our survey allowed us to record and discuss the effects of the Puyehue-Cordón Caulle eruption, showing that due to the high slopes, high current and discharge of the streams the volcanic material was rapidly exported to the Moreno Lake complex. Overall, this survey underscores the magnitude and timing of the allochthonous input revealing the terrestrial subsidy to food webs in

  11. The Bajada del Diablo astrobleme-strewn field, central Patagonia Argentina: Extending the exploration to surrounding areas

    NASA Astrophysics Data System (ADS)

    Acevedo, R. D.; Rabassa, J.; Ponce, J. F.; Martínez, O.; Orgeira, M. J.; Prezzi, C.; Corbella, H.; González-Guillot, M.; Rocca, M.; Subías, I.; Vásquez, C.

    2012-10-01

    The Bajada del Diablo astrobleme-strewn field is a huge domain of enigmatic circular structures located in central Patagonia. Three more localities are herein described, adding to the first area studied so far. Taking into consideration the four areas, a single, blurred crater dispersion ellipse has been identified. The four sectors now have been investigated, mapped, and georreferenced. Their circular structures, with a total of 185 (some of which are partially obliterated by erosion or sediment accumulation), were identified by remote sensing techniques, but many have been evaluated in situ and interpreted as impact craters. Moreover, two of the structures have been surveyed in detail in the field using a total station instrument. In addition to the previously known occurrence of circular structures on the Eruptive Complex Quiñelaf (Miocene basalts), the Pampa Sastre Fm. (Pliocene conglomerates), and of the Pleistocene pediment gravels and sands, and the geomorphological inferences that have suggested the extra-terrestrial origin of this event, we should now add that the recurrent absence of the cited Pliocene stratigraphic unit at the bottom of the craters is found in the pediment gravel and sands. Its removal has been interpreted as directly related to the impact, according to the magnetometric record of existing magnetic anomalies. Other preliminary observations on the collected samples (glass, breccias, and, most relevant, Fe-Ni-bearing spherules picked up within the impact zones) are herein discussed. Two hypotheses have been put forward about the nature of the possible impacting object that formed these astroblemes which, fragmented into hundreds of pieces, hit the surface of the Earth most likely in middle Pleistocene times. One of these hypotheses is related to the impact of a disintegrated asteroid of the rubble pile type, whereas a second hypothesis refers to the collision of a split comet with the Earth surface. The latter hypothesis is favoured since

  12. Bioindication of volatile elements emission by the Puyehue-Cordón Caulle (North Patagonia) volcanic event in 2011.

    PubMed

    Bubach, Débora; Pérez Catán, Soledad; Arribére, María; Guevara, Sergio Ribeiro

    2012-07-01

    The emission of volatile pollutants from the volcanic eruption of the Puyehue-Cordón Caulle complex (North Patagonia Andean Range) that started in June 4th, 2011, was investigated by bioindication means with the epyphytic fruticose lichen Usnea sp. The elemental composition of pooled samples made up with 10 lichen thalli were analysed by Instrumental Neutron Activation Analysis. Eleven sampling sites were selected within the impacted region at different distance from the volcanic source. Five sites were selected as they were already sampled in a previous study prior to the eruption. Two other new sampling sites were selected from outside the impacted zone to provide non-impacted baseline sites. The elements associated with the lichen incorporation of particulate matter (PM) of geological origin were identified by linear correlation with a geochemical tracer (Sm concentrations). The elements associated with PM uptake were Ce, Eu, Fe, Hf, La, Lu, Na, Nd, Sb, Sc, Se, Ta, Tb, Th, U, and Yb. Arsenic and Cs concentrations showed contributions exceeding the PM fraction in sites near the volcanic centre, also higher than the baseline concentrations, which could be associated with permanent emissions from the geothermal system of the Puyehue-Cordón Caulle complex. The lichen concentrations of Ba, Ca, Co, Hg, K, Rb, Sr, and Zn were not associated with the PM, not showing higher concentrations in the sites nearby the volcanic source or respect to the baseline values either. Therefore, there is no indication of the emission of volatile forms of these elements in the lichen records. The lichen records only identified Br volatile emissions associated with the Puyehue-Cordón Caulle complex eruption in 2011.

  13. Exploring the Diversity and Antimicrobial Potential of Marine Actinobacteria from the Comau Fjord in Northern Patagonia, Chile.

    PubMed

    Undabarrena, Agustina; Beltrametti, Fabrizio; Claverías, Fernanda P; González, Myriam; Moore, Edward R B; Seeger, Michael; Cámara, Beatriz

    2016-01-01

    Bioprospecting natural products in marine bacteria from fjord environments are attractive due to their unique geographical features. Although, Actinobacteria are well known for producing a myriad of bioactive compounds, investigations regarding fjord-derived marine Actinobacteria are scarce. In this study, the diversity and biotechnological potential of Actinobacteria isolated from marine sediments within the Comau fjord, in Northern Chilean Patagonia, were assessed by culture-based approaches. The 16S rRNA gene sequences revealed that members phylogenetically related to the Micrococcaceae, Dermabacteraceae, Brevibacteriaceae, Corynebacteriaceae, Microbacteriaceae, Dietziaceae, Nocardiaceae, and Streptomycetaceae families were present at the Comau fjord. A high diversity of cultivable Actinobacteria (10 genera) was retrieved by using only five different isolation media. Four isolates belonging to Arthrobacter, Brevibacterium, Corynebacterium and Kocuria genera showed 16S rRNA gene identity <98.7% suggesting that they are novel species. Physiological features such as salt tolerance, artificial sea water requirement, growth temperature, pigmentation and antimicrobial activity were evaluated. Arthrobacter, Brachybacterium, Curtobacterium, Rhodococcus, and Streptomyces isolates showed strong inhibition against both Gram-negative Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica and Gram-positive Staphylococcus aureus, Listeria monocytogenes. Antimicrobial activities in Brachybacterium, Curtobacterium, and Rhodococcus have been scarcely reported, suggesting that non-mycelial strains are a suitable source of bioactive compounds. In addition, all strains bear at least one of the biosynthetic genes coding for NRPS (91%), PKS I (18%), and PKS II (73%). Our results indicate that the Comau fjord is a promising source of novel Actinobacteria with biotechnological potential for producing biologically active compounds.

  14. Atmospheric background trace elements deposition in Tierra del Fuego region (Patagonia, Argentina), using transplanted Usnea barbata lichens.

    PubMed

    Conti, Marcelo Enrique; Finoia, Maria Grazia; Bocca, Beatrice; Mele, Giustino; Alimonti, Alessandro; Pino, Anna

    2012-01-01

    Lichen, Usnea barbata, transplants taken from Tierra del Fuego (south Patagonia, Argentina) were tested as potential biomonitors of atmospheric airborne deposition in an apparently pristine environment. In 2005, lichens were sampled in a reference site (n = 31) and transplanted in the northern Region of Tierra del Fuego. After, respectively, 1 month and 1 year of exposure, we collected them. The aim of the study was to determine the bioaccumulation of 26 elements in order to evaluate the background levels in the selected area. Samples were analyzed by the sector field inductively coupled plasma mass spectrometry. Discriminant analysis on principal component analysis factors was applied in order to explore the relationship among the different elements as far as time and spatial variation in transplants regards. The analysis was tested by Monte Carlo test based on 999 replicates. The most important contamination source resulted to be the atmospheric soil particle deposition. Furthermore, the results were compared with those obtained from the lichens collected in central and southern Tierra del Fuego. This study confirms the ability of U. barbata to reflect the background levels of the 26 elements in that environment. Compared with other background sites in the world, we did confirm that Tierra del Fuego lichens have a low content of the studied elements. Tierra del Fuego turned out not to be a pristine environment as supposed, but it can be considered as a reference basal ecosystem for useful comparisons among different geographical areas. These findings can be very relevant and useful for environmental conservation programs.

  15. Fire responses to postglacial climate change and human impact in northern Patagonia (41–43°S)

    PubMed Central

    Iglesias, Virginia; Whitlock, Cathy

    2014-01-01

    Forest/steppe boundaries are among the most dynamic ecosystems on Earth and are highly vulnerable to changes in climate and land use. In this study we examine the postglacial history of the Patagonian forest/steppe ecotone (41–43°S) to better understand its sensitivity to past variations in climate, disturbance, and human activity before European colonization. We present regional trends in vegetation and biomass burning, as detected by generalized additive models fitted to seven pollen and charcoal records, and compare the results with other paleoenvironmental data, as well as archeological and ecological information to (i) estimate postglacial fire trends at regional scales, (ii) assess the evolution of climate–vegetation–fire linkages over the last 18,000 calibrated (cal) years B.P., and (iii) evaluate the role of humans in altering pre-European landscapes and fire regimes. Pollen and charcoal data indicate that biomass burning was relatively low during warm/dry steppe-dominated landscapes in the late glacial/Early Holocene transition and increased as more humid conditions favored forest development after ca. 10,000 cal years B.P. Postglacial fire activity was thus limited by fuel availability associated with sparse vegetation cover rather than by suitable climate conditions. In contrast to extensive burning by European settlers, variations in indigenous population densities were not associated with fluctuations in regional or watershed-scale fire occurrence, suggesting that climate–vegetation–fire linkages in northern Patagonia evolved with minimal or very localized human influences before European settlement. PMID:25489077

  16. Structure and Velocities of the Northeastern Santa Cruz Mountains and the Western Santa Clara Valley, California, from the SCSI-LR Seismic Survey

    USGS Publications Warehouse

    Catchings, R.D.; Goldman, M.R.; Gandhok, G.

    2006-01-01

    Introduction: The Santa Clara Valley is located in the southern San Francisco Bay area of California and generally includes the area south of the San Francisco Bay between the Santa Cruz Mountains on the southwest and the Diablo Ranges on the northeast. The area has a population of approximately 1.7 million including the city of San Jose, numerous smaller cities, and much of the high-technology manufacturing and research area commonly referred to as the Silicon Valley. Major active strands of the San Andreas Fault system bound the Santa Clara Valley, including the San Andreas fault to the southwest and the Hayward and Calaveras faults to the northeast; related faults likely underlie the alluvium of the valley. This report focuses on subsurface structures of the western Santa Clara Valley and the northeastern Santa Cruz Mountains and their potential effects on earthquake hazards and ground-water resource management in the area. Earthquake hazards and ground-water resources in the Santa Clara Valley are important considerations to California and the Nation because of the valley's preeminence as a major technical and industrial center, proximity to major earthquakes faults, and large population. To assess the earthquake hazards of the Santa Clara Valley better, the U.S. Geological Survey (USGS) has undertaken a program to evaluate potential earthquake sources and potential effects of strong ground shaking within the valley. As part of that program, and to better assess water resources of the valley, the USGS and the Santa Clara Valley Water District (SCVWD) began conducting collaborative studies to characterize the faults, stratigraphy, and structures beneath the alluvial cover of the Santa Clara Valley in the year 2000. Such geologic features are important to both agencies because they directly influence the availability and management of groundwater resources in the valley, and they affect the severity and distribution of strong shaking from local or regional

  17. Type material of Platyhelminthes (Monogenoidea) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016

    PubMed Central

    Lopes, Daniela A.; Mainenti, Adriana; Sanches, Magda; Knoff, Marcelo; Gomes, Delir Corrêa

    2016-01-01

    Abstract A catalogue of type material of monogenoids deposited in the Helminthological Collection of the Oswaldo Cruz Institute, FIOCRUZ (CHIOC), between 1979 and 2016, is presented, given that the last list of types was produced in 1979. The monogenoid collection comprises type lots for 203 species, distributed across 14 families and 68 genera. Specific names are listed systematically, followed by type host, infection site, type locality, specimens with the collection numbers and references. The classification and the nomenclature of the species have been updated. PMID:27667946

  18. Preliminary geochemical data on shallow marine mollusc from middle Pleistocene-Holocene beach ridges in the gulf of S. Jorge (Patagonia, Argentina)

    NASA Astrophysics Data System (ADS)

    Consoloni, Ilaria; Zanchetta, Giovanni; Aguirre, Marina L.; Baneschi, Ilaria; Boretto, Gabriella M.; Dallai, Luigi; D'Orazio, Massimo; Fallick, Anthony E.; Isola, Ilaria; Pappalardo Adriano Ribolini, Marta

    2010-05-01

    The Patagonia coast comprised between ca 45° S and 43° S preserves a spectacular succession of Quaternary raised beach deposits mostly composed by gravelly beach-ridge successions containing abundant storm accumulations of mollusc remains. Currently, this coastal area is interested by the competing action of the warm Brazilian current from north and the Falkland (Malvinas) current from the south, and roughly it corresponds to the boundary of the Magellanean and Argentinean zooprovinces. Although paleontological studies have been conducted in the recent past (e.g. Aguirre, 2003) there are not practically geochemical studies on these natural archives to infer local paleoceanographic and paleoclimate changes. Preliminary geochemical studies (petrography, stable isotopes, trace elements) on the aragonitic shell Prototaqua antiqua collected in various localities spanning from Holocene to Middle Pleistocene (MIS 9 to MIS 1, e.g. Schellmann and Radke, 2000) successions indicate that this species is relatively well preserved and can be used for the reconstruction of the past coastal oceanographic changes in the area. Aguirre, M.L., 2003. Late Pleistocene and Holocene palaeoenvironments in Golfo San Jorge, Patagonia: molluscan evidence. Marine Geology 194, 3-30. Schellmann, G., Radtke, U., 2000. ESR dating of stratigraphically well-constrained marine terraces along the Patagonian Atlantic coast (Argentina). Quaternary International 68/71, 261-273.

  19. Role of wild plant foods among late Holocene hunter-gatherers from Central and North Patagonia (South America): an approach from dental evidence.

    PubMed

    Bernal, Valeria; Novellino, Paula; Gonzalez, Paula N; Perez, S Ivan

    2007-08-01

    This study evaluates the role of plant foods in the subsistence of hunter-gatherers that inhabited the Central East, Northwest, and Northeast Patagonia (Argentina) during the late Holocene (ca. 3,000-500 years BP). The goal of the present study is to assess the temporal variation of dental caries ratio and wear rate in skeletal samples to ascertain if the biological information supports the dietary shift toward greater consumption of wild plant foods around 1,500 years BP, suggested by other types of evidence. The authors registered caries, antemortem and postmortem tooth loss, and tooth wear from eight samples belonging to hunter-gatherers from Patagonia for which chronological sequences from early late Holocene (ca. 3,000-1,500 years BP) up to final late Holocene (ca. 1,500-500 years BP) are available. The results indicate that caries percentages in Patagonian samples fall within the range established for hunter-gatherers but there are significant geographical differences. In addition, caries ratio does not change significantly through time, so the amount of carbohydrates consumed seems to have remained fairly constant since 3,000 years BP. In contrast, there is a marked temporal trend toward the reduction of wear rates in the three areas, suggesting a faster rate in early late Holocene than in final late Holocene. These results would reflect a change to less hard and/or abrasive diets in the final late Holocene, probably owing to differences in food processing methods employed.

  20. Paleomagnetism of Jurassic and Cretaceous rocks in central Patagonia: a key to constrain the timing of rotations during the breakup of southwestern Gondwana?

    NASA Astrophysics Data System (ADS)

    Geuna, Silvana E.; Somoza, Rubén; Vizán, Haroldo; Figari, Eduardo G.; Rinaldi, Carlos A.

    2000-08-01

    A paleomagnetic study in Jurassic and Cretaceous rocks from the Cañadón Asfalto basin, central Patagonia, indicates the occurrence of about 25-30° clockwise rotation in Upper Jurassic-lowermost Cretaceous rocks, whereas the overlying mid-Cretaceous rocks do not show evidence of rotation. This constrains the tectonic rotation to be related to a major regional unconformity in Patagonia, which in turn seems to be close in time with the early opening of the South Atlantic Ocean. The sense and probably the timing of this rotation are similar to those of other paleomagnetically detected rotations in different areas of southwestern Gondwana, suggesting a possible relationship between these and major tectonic processes related with fragmentation of the supercontinent. On the other hand, the mid-Cretaceous rocks in the region yield a paleopole located at Lat. 87° South, Long. 159° East, A95=3.8°. This pole position is consistent with coeval high-quality paleopoles of other plates when transferred to South American coordinates, implying it is an accurate determination of the Aptian (circa 116 Ma) geomagnetic field in South America.

  1. Nitrogen cycling and N2O production in the water column of the ferruginous meromictic Lake La Cruz (Spain)

    NASA Astrophysics Data System (ADS)

    Tischer, Jana; Zopfi, Jakob; Frame, Caitlin H.; Jegge, Corinne; Kirsten, Oswald; Andreas, Brand; Miracle, Maria R.; Vicente, Eduardo; Lehmann, Moritz F.

    2016-04-01

    Ferruginous meromictic lakes are rare systems, considered potential modern analogues for an ancient Archean ferruginous Ocean. They may therefore represent valuable model ecosystems to study biogeochemical processes of early Earth history, in particular, the interaction between the iron (Fe) and other element cycles such as the complex nitrogen (N) cycle. In context of its exceptional water chemistry, we studied the N-cycling in the meromictic, ferruginous Lake La Cruz in the Central Iberian Ranges in Spain, combining i) general water column chemistry and detailed N speciation ii) stable isotope composition and intramolecular 15N distributions (site preference) of dissolved N2O and iii) 15N-isotope label incubation experiments, to identify and quantify biotic and abiotic N2O and N2 production pathways. Nitrification was identified as the main N2O production mechanism in the oxic zone, based on the N2O concentration profile and the isomeric composition of N2O (site preference = 24.7) at the depth of maximum concentration relative to the surface water. A second N2O peak of 23 nmol/L was observed within the chemocline, and relatively low values for the δ15N-N2O (-1.1) and a site preference of 16.1‰ with respect to the oxic water column suggest that here incomplete (nitrifier) denitrification is the dominant N2O production pathway. However, based on the bulk dual N-versus-O isotope signature, other production mechanisms cannot be excluded at this point. Within the anoxic water column, N2O is consumed quantitiatively to N2, consistent with 15N-NO3- incubation experiments, showing denitrification (and anammox) activity below the redox transition zone. The overlap of Fe and N-species (N2O, NO2-) in the water column is small, therefore abiotic N2O production is most likely negligible. The planned analysis of the NO3- and NH4+ isotopic signatures will provide further insight into the origin of N2O. Additionally, molecular biological analyses will provide information on

  2. Effects of environmental amenities and locational disamenities on home values in the Santa Cruz watershed: a hedonic analysis using census data

    USGS Publications Warehouse

    Arora, Gaurav; Frisvold, George; Norman, Laura

    2014-01-01

    For this study, we used the hedonic pricing method to measure the effects of natural amenities on home prices in the U.S-side of the Santa Cruz Watershed. We employed multivariate spatial regression techniques to estimate how difference factors affect median home values in 613 census block groups of the 2000 Census, accounting for spatial autocorrelation, spatial lags, and/or spatial heterogeneity in the data. Diagnostic tests suggest that failure to account for the hedonic model can be classified as (1) physical features of the housing stock, (2) neighborhood characteristics, and (3) environmental attributes. Census data was combined with GIS data for vegetation and land cover, land administration, measures of species richness and open space, and proximity to amenities and disamenities. Census block groups close to the US-Mexico border of airports/air bases were negative. Results suggest that policies to maintain biodiversity and open space provide economic benefits to homeowners, reflected in higher home values. Future research will quantify the marginal effects of regression explanatory variables on home values to assess their economic and policy significant. These marginal effects will be used as input indicators to discern potential economic impacts of various scenarios in the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM). Future research will also expand this effort into the Mexican-portion of the watershed.

  3. Geochemical characterization of tarballs on beaches along the California coast. Part I - Shallow seepage impacting the Santa Barbara Channel Islands, Santa Cruz, Santa Rosa and San Miguel

    USGS Publications Warehouse

    Hostettler, F.D.; Rosenbauer, R.J.; Lorenson, T.D.; Dougherty, J.

    2004-01-01

    Tarballs are common along the southern California coastline. This study investigates tarballs from beaches along this coastline, with a focus on Santa Cruz, Santa Rosa, and San Miquel Islands in the Santa Barbara Channel. The tarballs were fingerprinted using biomarker and stable carbon isotope parameters, and then grouped according to genetic similarities. The data show that the tarballs are of natural and not anthropogenic origin and that all originate from source rock within the Miocene Monterey Formation via shallow seeps offshore. Sterane biomarker parameters were found to vary widely in the sample set. Biodegradation, especially of the regular steranes, is the primary process impacting the biomarker distributions in a large group of samples. The most common tarball occurrences appear to come from offshore seepage near the west end of Santa Cruz Island. Another major group most likely was transported north from near Santa Monica Bay. Several individual occurrences of some of these tarball groups also were found on beaches as far north as Pt. Reyes and as far south as San Diego, indicating significant long-distance dispersal by ocean currents. This study begins a library of tarball fingerprints to be used as a database to help distinguish between natural and anthropogenic tar occurrences all along the California coast, and to compare shallow seepage with future samples of deeper production oils from the same area.

  4. Sedimentology and paleoenvironments of the Las Chacritas carbonate paleolake, Cañadón Asfalto Formation (Jurassic), Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Cabaleri, Nora G.; Benavente, Cecilia A.

    2013-02-01

    The Las Chacritas Member is the lower part of the Cañadón Asfalto Formation (Jurassic). The unit is a completely continental limestone succession with volcanic contributions that were deposited during the development of the Cañadón Asfalto Rift Basin (Chubut province, Patagonia, Argentina). A detailed sedimentological analysis was performed in the Fossati depocenter to determine the paleoenvironments that developed in the context of this rift. The Las Chacritas Member represents a carbonate paleolake system with ramp-shaped margins associated with wetlands that were eventually affected by subaerial exposure and pedogenesis. This process is represented by three main subenvironments: a) a lacustrine setting sensu stricto (lacustrine limestone facies association), represented by Mudstones/Wackestones containing porifera spicules (F1), Intraclastic packstones (F6) and Tabular stromatolites (F10) in which deposition and diagenesis were entirely subaqueous; b) a palustrine setting (palustrine limestone facies association) containing Microbial Mudstones (F2), Intraclastic sandy packstone with ostracode remains (F3), Oncolitic packstone (F5), Brecciated limestone (F7) and Nodular-Mottled limestone (F8) representing shallow marginal areas affected by groundwater fluctuations and minor subaerial exposure; and c) a pedogenic paleoenvironment (pedogenic limestone facies association) including Intraclastic limestone (F4) and Packstones containing Microcodium (F9) facies displaying the major features of subaerial exposure, pedogenic diagenesis and the development of paleosols. The fluvial-palustrine-lacustrine succession shows a general shallow upward trend in which contraction-expansion cycles are represented (delimited by exposure and surface erosion). The variations in the successive formations reflect the responses to fluctuations in a combination of two major controls, the tectonic and local climatic variables. The predominance of the palustrine facies associations was

  5. Diverse subaerial and sublacustrine hot spring settings of the Cerro Negro epithermal system (Jurassic, Deseado Massif), Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Guido, Diego M.; Campbell, Kathleen A.

    2012-06-01

    The Late Jurassic (~ 150 Ma) Cerro Negro volcanic-epithermal-geothermal system (~ 15 km2 area), Deseado Massif, Patagonia, Argentina, includes two inferred volcanic emission centers characterized by rhyolitic domes linked along NW-SE regional faults that are associated with deeper level Au/Ag mineralization to the NW, and with shallow epithermal quartz veins and mainly travertine surface hot spring manifestations to the SE. Some travertines are silica-replaced, and siliceous and mixed silica-carbonate geothermal deposits also are found. Five hot spring-related facies associations were mapped in detail, which show morphological and textural similarities to Pleistocene-Recent geothermal deposits at Yellowstone National Park (U.S.A.), the Kenya Rift Valley, and elsewhere. They are interpreted to represent subaerial travertine fissure ridge/mound deposits (low-flow spring discharge) and apron terraces (high-flow spring discharge), as well as mixed silica-carbonate lake margin and shallow lake terrace vent-conduit tubes, stromatolitic mounds, and volcano-shaped cones. The nearly 200 mapped fossil vent-associated deposits at Cerro Negro are on a geographical and numerical scale comparable with subaerial and sublacustrine hydrothermal vents at Mammoth Hot Springs, and affiliated with Yellowstone Lake, respectively. Overall, the Cerro Negro geothermal system yields paleoenvironmentally significant textural details of variable quality, owing to both the differential preservation potential of particular subaerial versus subaqueous facies, as well as to the timing and extent of carbonate diagenesis and silica replacement of some deposits. For example, the western fault associated with the Eureka epithermal quartz vein facilitated early silicification of the travertine deposits in the SE volcanic emission center, thereby preserving high-quality, microbial macro- and micro-textures of this silica-replaced "pseudosinter." Cerro Negro provides an opportunity to reconstruct

  6. Postfire encroachment of Fabiana imbricata is real? Assessing changes of shrubland occupation during 40 years in NW Patagonia steppe

    NASA Astrophysics Data System (ADS)

    Lasaponara, Rosa; Oddi, Facundo; Ghermandi, Luciana

    2014-05-01

    Landscapes are dynamic in space and time, being spatio-temporal processes of particular interest for landscape ecology. In particular, grasslands can change their structure through the expansion of shrubs in the landscape matrix. Shrub encroachment affect biodiversity as well as forage availability that is the key component of the productive use of rangelands. However, despite its recognition as a global problem, knowledge on the rates, dynamics and encroachment patterns is even scarce. For example, although it is generally accepted that fire control shrub encroachment, certain shrubby species could be favored by the occurrence of fire. In northwestern Patagonian steppe, Fabiana imbricata form large monospecific shrublands that are part of the landscape mosaic and its dynamics of regeneration is strongly related to fire. This long-lived shrub (≡ 150 years) is a typical seeder that is killed by fire and recruits seedlings almost exclusively in post-fire, establishing even-age patches. Our objective was to determine whether F. imbricata shrublands have expanded during the last 40 years in a landscape fire prone. The study area corresponds to San Ramon ranch (22,000 ha) located in northwestern Patagonia steppe, Argentina (latitude -41° 04'; longitude -70° 51'). Two distribution maps of the species were made that corresponds to the study area in 1968 and 2011. The 1968 map was elaborated from the digitalization of aerial photographs (1:45000) while the 2011 map was produced with very high resolution satellite images, current aerial photographs and GPS field data. Both maps were loaded into a GIS environment, in which landscape metrics at patch and class level were determined and then compared. From remote sensing and dendroecological techniques, we know that the study area was almost entirely affected by fires during the study period. Therefore, the comparison of both maps allows us to know post-fire changes in the shrublands spatial configuration at the landscape

  7. First evidence of Dinophysistoxin-1 ester and carcinogenic polycyclic aromatic hydrocarbons in smoked bivalves collected in the Patagonia fjords.

    PubMed

    García, Carlos; González, Viviana; Cornejo, Carlos; Palma-Fleming, Hernán; Lagos, Néstor

    2004-02-01

    Diarrhetic shellfish poisoning (DSP) is a gastrointestinal disease caused by fat-soluble polyether toxins produced by dinoflagellates and accumulated in shellfish. Up to the present, only four fat-soluble polyethers have been known as diarrhetic shellfish toxins. Among them,*** Okadaic acid, Dinophysistoxin-1, Dinophysistoxin-2 and Dinophysistoxin-3. Outbreaks associated with DSP have occurred in the Chilean Patagonia fjords since 1970. Native people, who live in small communities close to the southern fjords, smoke fresh shellfish. During this popular smoking procedure, they impregnate the shellfish with polycyclic aromatic hydrocarbons, as incomplete combustion products, which are potent carcinogenic compounds, this product is sold in local markets without phycotoxins analysis or inclusion in any monitoring program. The present paper shows, DSP phycotoxins quantitation, using high performance liquid chromatography with fluorescent and mass spectrometric detection and the measurements of polycyclic aromatic hydrocarbons by gas chromatography with mass detection, in smoked shellfish samples. The presence of Dinophysistoxin-3, the Dinophysistoxin-1 ester (7-O-acyl-derivatives of dinophysistoxin-1), was assessed in all shellfish samples analyzed. The 7-OH in Dinophysistoxin-1 was esterified with palmitic fatty acid. The shellfish meat contains seven polycyclic aromatic hydrocarbons, among them fluoranthene, phenanthrene, anthracene, pyrene and benzo[a]pyrene. The gas chromatography-mass spectrometry analysis showed four of the six most frequent carcinogenic polycyclic aromatic hydrocarbons reported. The content of benzo[a]pyrene in the Razor Clam and Ribbed Mussel were 78.61 and 4.94 ng/g of shellfish dry weight, respectively. In both cases the benzo[a]pyrene amounts were greater than the acceptable tolerance limits of 1 microg/kg of sample. The Razor Clam samples also show amount further above the maximum label regulated by FAO/WHO (10 microg/kg). The presence of

  8. Crustal segments in the North Patagonian Massif, Patagonia: An integrated perspective based on Sm-Nd isotope systematics

    NASA Astrophysics Data System (ADS)

    Martínez Dopico, Carmen I.; López de Luchi, Mónica G.; Rapalini, Augusto E.; Kleinhanns, Ilka C.

    2011-03-01

    New insights on the Paleozoic evolution of the continental crust in the North Patagonian Massif are presented based on the analysis of Sm-Nd systematics. New evidence is presented to constrain tectonic models for the origin of Patagonia and its relations with the South American crustal blocks. Geologic, isotopic and tectonic characterization of the North Patagonian Massif and comparison of the Nd parameters lead us to conclude that: (1) The North Patagonian Massif is a crustal block with bulk crustal average ages between 2.1 and 1.6 Ga TDM (Nd) and (2) At least three metamorphic episodes could be identified in the Paleozoic rocks of the North Patagonian Massif. In the northeastern corner, Famatinian metamorphism is widely identified. However field and petrographic evidence indicate a Middle to Late Cambrian metamorphism pre-dating the emplacement of the ca. 475 Ma granitoids. In the southwestern area, are apparent 425-420 Ma (?) and 380-360 Ma metamorphic peaks. The latter episode might have resulted from the collision of the Antonia terrane; and (3) Early Paleozoic magmatism in the northeastern area is coeval with the Famatinian arc. Nd isotopic compositions reveal that Ordovician magmatism was associated with attenuated crust. On the southwestern border, the first magmatic recycling record is Devonian. Nd data shows a step by step melting of different levels of the continental crust in the Late Palaeozoic. Between 330 and 295 Ma magmatism was likely the product of a crustal source with an average 1.5 Ga TDM (Nd). Widespread magmatism represented by the 295-260 Ma granitoids involved a lower crustal mafic source, and continued with massive shallower-acid plutono volcanic complexes which might have recycled an upper crustal segment of the Proterozoic continental basement, resulting in a more felsic crust until the Triassic. (4) Sm-Nd parameters and detrital zircon age patterns of Early Paleozoic (meta)-sedimentary rocks from the North Patagonian Massif and those

  9. High Resolution Mapping of an Alleged Chemical Weapons Dump Site in the Santa Cruz Basin, offshore California

    NASA Astrophysics Data System (ADS)

    Brewer, P. G.; Peltzer, E. T.; Walz, P. M.; Caress, D. W.; Thomas, H. J.

    2013-12-01

    Nautical charts record seven locations off the coast of California labeled as 'Chemical Munitions Dumping Area, Disused' that together cover some 12,000 km2 of sea floor. However only one such chemical munitions site is officially documented and no record exists of any chemical munitions disposed of at other locations, thus creating confusion. We have executed a one day AUV mapping survey of a corner of one such site in the Santa Cruz Basin, south of Port Hueneme, to examine and investigate the debris field. The region is covered with soft sediment and the overlying water is very low in oxygen at ~10 μmol/kg. The processed 110 kHz sidescan data revealed some 754 targets in 25.6 km2 for an average of 29 targets per km2. This was followed by two ROV dives to investigate the targets identified. We found but one false positives among the over 40 targets visited, and found items ranging from two distinct lines of unmarked or labeled and now empty barrels, two target drones, and much miscellaneous debris including 4-packs of cat food cans and a large ships mast over 30m in length. There was zero evidence of chemical weapons materiel as expected given the lack of official records. Almost all of the targets were covered in dense and colorful assemblages of invertebrates: sponges, anemones, and crabs. Where barrels were sufficiently open for full visual inspection, the interior sea floor appeared to have become fully anoxic and was covered in white and yellow bacterial mat. The area chosen for our survey (centered at 33.76 deg N 119.56 deg W) was across the north western boundary of the marked site, and represents only ~ 10% percent of the designated area. Our expectation, that human nature would drive the disposal activities to the nearest corner of the chosen area rather than the center of the field appears to have been confirmed. Objects were found both within and outside of the boundary of the dump site. We have not surveyed the full marked area but there appears to be

  10. Time-domain electromagnetic signatures of polymetallic vein deposits in Cottonwood Canyon area, Santa Cruz County, Arizona

    USGS Publications Warehouse

    Bultman, Mark W.

    2002-01-01

    This report tests the usefulness of airborne time-domain electromagnetic (TEM) data on three mineral-resource-related issues: (1) to test whether known mineral deposits at or near the surface display any signal in the TEM data; 2) determine whether TEM data can be used to locate bedrock concealed by basin fill; and (3) if the exposed mineral deposits display a signal in the TEM data, to determine if whether deposits are recognizable at depth in outcropping bedrock or in bedrock concealed beneath basin fill. Because Earth's total-intensity magnetic field data are also acquired with the TEM data, these data are included in the analysis. The Cottonwood Canyon area in Santa Cruz County, Arizona, contains several polymetallic vein deposits, including those of the Tyndall, Salero, and Wrightson mining districts, all of which have had significant mineral production. Polymetallic vein deposits, which generally consist of veins of disseminated metallic minerals, commonly exhibit a response to electrical geophysical methods. Also, on the basis of other studies, the conditions that produced the polymetallic vein mineralization in the region are believed to extend offshore into the bedrock concealed by basin fill. The polymetallic vein deposits of the Cottonwood Canyon area all display a geophysical signature in the TEM data. These deposits occur in bedrock that has, in general, a very low resistivity. The polymetallic vein deposits are associated with high-conductivity regions that extend from deep in the bedrock to the surface. These high-conductivity regions can be quite narrow (100 m) or quite wide (1 km); most are relatively narrow. Every known mineral deposit or prospect is associated with a high-conductivity feature. High-conductivity regions can also occur without an association with known mineral deposits. Airborne TEM data appear to be able to locate the basin fill/bedrock contact beneath basin fill. The basin fill (both dry and saturated) is generally more

  11. Developing an Ecosystem Services online Decision Support Tool to Assess the Impacts of Climate Change and Urban Growth in the Santa Cruz Watershed; Where We Live, Work, and Play

    EPA Science Inventory

    Processes through which ecosystems provide goods or benefit people can be referred to as "ecosystems services”, which may be quantified to clarify decision-making, with techniques including cost-benefit analysis. We are developing an online decision support tool, the Santa Cruz W...

  12. Paleoseismic investigations in the Santa Cruz mountains, California: Implications for recurrence of large-magnitude earthquakes on the San Andreas fault

    USGS Publications Warehouse

    Schwartz, D.P.; Pantosti, D.; Okumura, K.; Powers, T.J.; Hamilton, J.C.

    1998-01-01

    Trenching, microgeomorphic mapping, and tree ring analysis provide information on timing of paleoearthquakes and behavior of the San Andreas fault in the Santa Cruz mountains. At the Grizzly Flat site alluvial units dated at 1640-1659 A.D., 1679-1894 A.D., 1668-1893 A.D., and the present ground surface are displaced by a single event. This was the 1906 surface rupture. Combined trench dates and tree ring analysis suggest that the penultimate event occurred in the mid-1600s, possibly in an interval as narrow as 1632-1659 A.D. There is no direct evidence in the trenches for the 1838 or 1865 earthquakes, which have been proposed as occurring on this part of the fault zone. In a minimum time of about 340 years only one large surface faulting event (1906) occurred at Grizzly Flat, in contrast to previous recurrence estimates of 95-110 years for the Santa Cruz mountains segment. Comparison with dates of the penultimate San Andreas earthquake at sites north of San Francisco suggests that the San Andreas fault between Point Arena and the Santa Cruz mountains may have failed either as a sequence of closely timed earthquakes on adjacent segments or as a single long rupture similar in length to the 1906 rupture around the mid-1600s. The 1906 coseismic geodetic slip and the late Holocene geologic slip rate on the San Francisco peninsula and southward are about 50-70% and 70% of their values north of San Francisco, respectively. The slip gradient along the 1906 rupture section of the San Andreas reflects partitioning of plate boundary slip onto the San Gregorio, Sargent, and other faults south of the Golden Gate. If a mid-1600s event ruptured the same section of the fault that failed in 1906, it supports the concept that long strike-slip faults can contain master rupture segments that repeat in both length and slip distribution. Recognition of a persistent slip rate gradient along the northern San Andreas fault and the concept of a master segment remove the requirement that

  13. The Interplay Between Deformation and Volcanism on Santa Cruz Island, Galápagos: A Multidisciplinary Study Using Structural, Geophysical, and Geochronological Analyses of Faults and Lavas

    NASA Astrophysics Data System (ADS)

    Schwartz, D. M.; Harpp, K. S.; Mittelstaedt, E. L.

    2014-12-01

    Santa Cruz Island is one of the oldest volcanoes in the Galápagos Archipelago; little is known about its history or its evolutionary relationship to the younger western shield volcanoes. Of particular note, the island's northern and southern flanks are deformed by a series of major normal faults of unknown origin. Using an array of multidisciplinary tools, including field mapping, GPS, gravity, Ar-Ar and geochronology, and 3He exposure dating, we construct a structural and volcanic history of Santa Cruz. The Ar-Ar ages reveal that since ~1.5 Ma, the island has experienced two phases of volcanism, separated by ~0.4 My. The first occurred from 1620 ± 15 to 1160 ± 35 ka (1σ); the second lasted from 699 ± 45 to 74 ± 19 ka. Volcanism during the second phase was focused along an E-W trending summit vent system, from which all <200 ka lavas were deposited on the southern flank. Structural observations suggest that the island has experienced two major faulting episodes. North flank faults formed after 1160 ± 35 ka, whereas the southern faults were initiated between 416 ± 18 and 27 ± 16 ka. Gravity results indicate two E-W trending, intrusive complexes; one is centered north of the island's summit and the other is beneath the southern flank. When integrated, our data are consistent with a model wherein the northern faults are associated with regional uplift occurring after 1.1 Ma and before 0.78 Ma (paleomag.; Bow, 1979). This deformation event may be related to the formation of the summit vent system and the initiation of the second phase of volcanism. The second volcanism phase is coincident with the formation of the southern faults. Southward spreading along the island's southern flank accommodated extension initiated by intrusions, which ceased with volcanism at ~20 ka. The extended volcanic activity characteristic of Santa Cruz and of other older Galapagos Islands may be the result of rejuvenated volcanism linked to regional uplift event(s); it may also

  14. First fossil record of Discocephalinae (Insecta, Pentatomidae): a new genus from the middle Eocene of Río Pichileufú, Patagonia, Argentina

    PubMed Central

    Petrulevičius, Julián F.; Popov, Yuri A.

    2014-01-01

    Abstract A new genus and species of Discocephalini, Acanthocephalonotum martinsnetoi gen. n. et sp. n. is described from Río Pichileufú, middle Eocene of Patagonia, Argentina at palaeolatitude ~ 46°S. The new species is the first fossil representative of the Discocephalinae. This taxon is extant in equatorial to subtropical America, and some species reach warm temperate latitudes (Buenos Aires province). The new genus is distinguished from the other genera of Discocephalini by the combination of these characters: interocular width greater than head length; head massive and quadrangular with the anterior margin almost straight; juga touching each other; labrum thick and curved; triangular ante-ocular process extending beyond the eye; broad spine-like antero-lateral process of the pronotum; pronotum explanate and bean shaped; scutellum triangular with a circular tongue reaching the anterior side of abdominal segment 7; and wings well developed with membrane just surpassing end of abdomen. PMID:25061387

  15. Rock-magnetic signature of precipitation and extreme runoff events in south-eastern Patagonia since 51,200 cal BP from the sediments of Laguna Potrok Aike

    NASA Astrophysics Data System (ADS)

    Lisé-Pronovost, A.; St-Onge, G.; Gogorza, C.; Jouve, G.; Francus, P.; Zolitschka, B.

    2014-08-01

    A 106-m long sediment sequence from the maar lake Laguna Potrok Aike in southern Patagonia was recovered in the framework of the International Continental Scientific Drilling Program (ICDP) Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO). About half of the sedimentary sequence is composed of mass movement deposits (MMDs) and the event-corrected record reaches back to 51,200 cal BP. Here we present a high-resolution rock-magnetic study revealing two sedimentary facies associated with MMDs and characterized by two different types of spurious gyroremanent magnetization (GRM) acquired during static alternating field demagnetization. The first rock-magnetic signature is detected in MMDs composed of reworked sand and tephra material. The signature consists of GRM acquired during demagnetization of the natural remanent magnetization (NRM) and other rock-magnetic properties typical of iron sulfides such as greigite. We interpret these intervals as authigenic formation of iron sulfides in suboxic conditions within the MMD. The second rock-magnetic signature consists of a series of 10 short intervals located on the top of MMDs characterized by GRM acquisition during demagnetization of the isothermal remanent magnetization (IRM). Based on geological, limnological, stratigraphic and climatic evidence these layers are interpreted as reflecting pedogenic hematite and/or goethite brought to the lake by runoff events related to precipitation and permafrost melt. The pedogenic iron minerals mobilized from the catchment most likely settled out of suspension on top of MMDs after a rapid remobilization event. The series of runoff events corresponds to periods of increased lacustrine productivity in Laguna Potrok Aike and are coeval within the limit of the chronology to warm periods of the Last Glacial as recorded in Antarctica, the deglaciation in the mid-latitudes of the Southern Hemisphere and enhanced precipitation during the Early Holocene in southeastern

  16. Reconstruction of a glacial lake outburst flood (GLOF) in the Engaño Valley, Chilean Patagonia: Lessons for GLOF risk management.

    PubMed

    Anacona, Pablo Iribarren; Mackintosh, Andrew; Norton, Kevin

    2015-09-15

    Floods from moraine-dammed lake failures can have long standing effects not only on riverine landscapes but also on mountain communities due to the high intensity (i.e. great depth and high velocities) and damaging capacity of glacial lake outburst floods (GLOFs). GLOFs may increase in frequency as glaciers retreat and new lakes develop and there is an urgent need to better understand GLOF dynamics and the measures required to reduce their negative outcomes. In Patagonia at least 16 moraine-dammed lakes have failed in historic time, however, data about GLOF dynamics and impacts in this region are limited. We reconstruct a GLOF that affected a small village in Chilean Patagonia in March 1977, by semi structured interviews, interpretation of satellite images and 2D hydraulic modelling. This provides insight into the GLOF dynamics and the planning issues that led to socioeconomic consequences, which included village relocation. Modelling shows that the water released by the GLOF was in the order of 12-13 × 10(6)m(3) and the flood lasted for about 10h, reaching a maximum depth of ~1.5m in Bahía Murta Viejo, ~ 26 km from the failed lake. The lake had characteristics in common with failed lakes worldwide (e.g. the lake was in contact with a retreating glacier and was dammed by a narrow-steep moraine). The absence of land-use planning and the unawareness of the GLOF hazard contributed to the village flooding. The Río Engaño GLOF illustrates how small-scale and short-distance migration is a reasonable coping strategy in response to a natural hazard that may increase in frequency as atmospheric temperature rises and glaciers retreat.

  17. Succession of Ground-Dwelling Beetle Assemblages After Fire in Three Habitat Types in the Andean Forest of NW Patagonia, Argentina

    PubMed Central

    Sasal, Yamila; Raffaele, Estela; Farji-Brener, Alejandro G.

    2010-01-01

    Wildfires are one of the major disturbances in the dynamics of forests and shrublands. However, little is known about their effects on insect communities that contribute to faunal biodiversity and play key roles in the ecosystem's dynamics. An intense and widespread fire occurred in 1999 in the Nahuel Huapi National Park in the Andean forest in northern Patagonia, Argentina. This fire affected adjacent, but different, habitat types. After the fire, beetle abundance, species richness and assemblage composition were compared among three habitats that were structurally different before the fire. These habitats were: 1) evergreen forest dominated by Nothofagus dombeyi (Mirb.) Oerst. (Fagales: Nothofagaceae), 2) a mixed forest of the evergreen conifer Austrocedrus chilensis (D. Don) Pic. Serm. and Bizzarri (Pinales: Cupressaceae) and N. dombeyi and 3) a shrubland with a diverse community of shrub species. The relationship between beetle diversity and vegetation structure was investigated over three consecutive years. Ground beetles were collected by pitfall traps, and plant species richness, vegetation cover, and height were measured. Beetle communities varied more over years between habitats during the early regeneration after fire. There was a shift in beetle assemblage composition with time after the fire in all habitat types, probably due to similar colonization rates and microclimatic conditions. Therefore, beetle succession was more influenced by recolonization and survivorship, accompanied by climatic conditions and recovery rate of plant communities over time, than it was influenced by pre-fire habitat conditions. These results suggest that in NW Patagonia, wildfire can have a substantial, short-term impact on beetle abundance and species composition. The pre-fire conditions of each habitat type determined the structure of post-fire communities of plants but not beetle assemblages. Wildfires produce simplification and homogenization of habitat types, and this

  18. Production of sulfur gases and carbon dioxide by synthetic weathering of crushed drill cores from the Santa Cruz porphyry copper deposit near Casa Grande, Pinal County, Arizona

    USGS Publications Warehouse

    Hinkle, M.E.; Ryder, J.L.; Sutley, S.J.; Botinelly, T.

    1990-01-01

    Samples of ground drill cores from the southern part of the Santa Cruz porphyry copper deposit, Casa Grande, Arizona, were oxidized in simulated weathering experiments. The samples were also separated into various mineral fractions and analyzed for contents of metals and sulfide minerals. The principal sulfide mineral present was pyrite. Gases produced in the weathering experiments were measured by gas chromatography. Carbon dioxide, oxygen, carbonyl sulfide, sulfur dioxide and carbon disulfide were found in the gases; no hydrogen sulfide, organic sulfides, or mercaptans were detected. Oxygen concentration was very important for production of the volatiles measured; in general, oxygen concentration was more important to gas production than were metallic element content, sulfide mineral content, or mineral fraction (oxide or sulfide) of the sample. The various volatile species also appeared to be interactive; some of the volatiles measured may have been formed through gas reactions. ?? 1990.

  19. Report of the USGS Coastal and Marine Geology Modeling Workshop, Pacific Marine Science Center, Santa Cruz, CA, March 22-23, 2005

    USGS Publications Warehouse

    Sherwood, Christopher R.

    2006-01-01

    A U.S. Geological Survey (USGS) Coastal and Marine Geology (CMG) Modeling Workshop was held to discuss the general topic of coastal modeling, defined broadly to include circulation, waves, sediment transport, water quality, ecology, sediment diagenesis, morphology change, and coastal evolution, on scales ranging from seconds and a few centimeters (individual ripples) to centuries (coastal evolution) and thousands of kilometers (tsunami propagation). The workshop was convened at the suggestion of CMG Program Management to improve communication among modelers and model users, assess modeling-related activities being conducted at the three centers (Florida Integrated Science Center, FISC; Pacific Marine Science Center; PMSC; and Woods Hole Science Center; WHSC), and develop goals, strategies, and plans for future modeling activities. The workshop represents a step toward developing a five-year strategic plan, and was timed to provide input for the FY06 prospectus. The workshop was held at the USGS Pacific Marine Science Center in Santa Cruz on March 22-23, 2005.

  20. Swath Bathymetry Surveys of the Monterey Bay Area from Point Ano Nuevo to Moss Landing, San Mateo, Santa Cruz, and Monterey Counties, California

    USGS Publications Warehouse

    Ritchie, Andrew C.; Finlayson, David P.; Logan, Joshua B.

    2010-01-01

    This report describes swath bathymetry and backscatter data acquired by the U.S. Geological Survey on the continental shelf within the Monterey Bay National Marine Sanctuary between Point A?o Nuevo and Moss Landing, in San Mateo, Santa Cruz, and Monterey Counties, Calif. The survey was done for the California Seafloor Mapping Program (CSMP), in field activities S-7-09-MB and S-10-09-MB, by the Western Coastal and Marine Geology (WCMG) Team of the U.S. Geological Survey (USGS). The data were aquired in two seperate surveys: (1) between August 13, 2009 and September 3, 2009, personnel from WCMG completed field activity S-7-09-MB, from Point A?o Nuevo south to Table Rock, as well as a block west of Soquel Canyon; (2) between October 12 and December 16, 2009, WCMG conducted field activity S-10-09-MB, surveying between Table Rock and Moss Landing.