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Sample records for atacama desert chile

  1. Palaeoindian occupation of the Atacama Desert, northern Chile

    Science.gov (United States)

    Grosjean, Martin; Núñez, Lautaro; Cartajena, Isabel

    2005-10-01

    Palaeoindian occupation of the Atacama Desert in northern Chile has been found between 12 600 and 10 200 cal. yr BP. The new site at Salar Punta Negra (24°28S/60°53W/2976 m) includes about 1000 classifiable, mostly unifacial artefacts and, uniquely, three different diagnostic types of early projectile points. Two of the Lateglacial/early Holocene projectile types have wide distribution and are known from different geographical areas in South America: the Palaeoindian Fell fish-tail point mainly from the southern cone of South America, and the triangular Tuina points typical of the Puna of the south-central Andes in northern Chile and northwestern Argentina. In addition, we found a third type, a stemmed point typical for the Salar Punta Negra. Filling a large geographical gap of Fell occupation, the site at Salar Punta Negra provides evidence for generally much higher mobility and diversity of early cultures, and supports an Andean-Pacific route for early human exploration of South America to the south through the desert at intermediate altitudes. Contemporaneous high-amplitude climatic changes were fundamental preconditions to provide adequate environments and habitats, and to make Palaeoindian hunting-gathering occupation possible in the Atacama Desert.

  2. Perennial stream discharge in the hyperarid Atacama Desert of northern Chile during the latest Pleistocene

    OpenAIRE

    Nester, Peter L.; Gayó, Eugenia; Latorre, Claudio; Jordan, Teresa E.; Blanco, Nicolás

    2007-01-01

    A large fraction of the vital groundwater in the Atacama Desert of northern Chile is likely composed of “fossil” or “ancient” reserves that receive little or no recharge in today's hyperarid climate. Here, we present evidence for latest Pleistocene perennial streamflow in canyons from the hyperarid core of the Atacama Desert in northern Chile. Fluvial terraces in the Pampa del Tamarugal (PdT) basin (21°S) contain widespread fossil wood, in situ roots, and well preserved leaf litter deposits i...

  3. Microbial Colonization of the Salt Deposits in the Driest Place of the Atacama Desert (Chile)

    Science.gov (United States)

    Stivaletta, Nunzia; Barbieri, Roberto; Billi, Daniela

    2012-06-01

    The Atacama Desert (Chile), one of the most arid places on Earth, shows hostile conditions for the development of epilithic microbial communities. In this study, we report the association of cyanobacteria ( Chroococcidiopsis sp.) and bacteria belonging to Actinobacteria and Beta-Gammaproteobacteria and Firmicutes phyla inhabiting the near surface of salt (halite) deposits of the Salar Grande Basin, Atacama Desert (Chile). The halite deposits were investigated by using optical, confocal and field emission scanning electron microscopes, whereas culture-independent molecular techniques, 16S rDNA clone library, alongside RFLP analysis and 16S rRNA gene sequencing were applied to investigate the bacterial diversity. These microbial communities are an example of life that has adapted to extreme environmental conditions caused by dryness, high irradiation, and metal concentrations. Their adaptation is, therefore, important in the investigation of the environmental conditions that might be expected for life outside of Earth.

  4. VEGETATIVE GROWTH AND EARLY PRODUCTION OF SIX OLIVE CULTIVARS, IN SOUTHERN ATACAMA DESERT, CHILE

    OpenAIRE

    Freddy MORA; TAPIA, Francisco; Carlos Alberto; Elias Nunes

    2007-01-01

    Tree survival, early fruit production, vegetative growth and alternate bearing were examined in six different olive cultivars (Barnea, Biancolilla, Coratina, Empeltre, Koroneiki and Leccino) under intensive agronomic conditions i southern Atacama Desert, in the Coquimbo Region of Chile. The cultivars were evaluated over four successive years and had a high survival rate (93%) confi rming their potential for these dry-lands. Fruit production (recorded over the growing seasons 2002-2003), veget...

  5. Impact of Empire Expansion on Household Diet: The Inka in Northern Chile's Atacama Desert

    OpenAIRE

    Vinton, Sheila Dorsey; Perry, Linda; Reinhard, Karl J.; Santoro, Calogero M.; Teixeira-Santos, Isabel

    2009-01-01

    The impact of expanding civilization on the health of American indigenous societies has long been studied. Most studies have focused on infections and malnutrition that occurred when less complex societies were incorporated into more complex civilizations. The details of dietary change, however, have rarely been explored. Using the analysis of starch residues recovered from coprolites, here we evaluate the dietary adaptations of indigenous farmers in northern Chile's Atacama Desert during the...

  6. Bacterial community structure in the hyperarid core of the Atacama Desert, Chile

    Science.gov (United States)

    Drees, Kevin P.; Neilson, Julia W.; Betancourt, Julio L.; Quade, Jay; Henderson, David A.; Pryor, Barry M.; Maier, Raina M.

    2006-01-01

    Soils from the hyperarid Atacama Desert of northern Chile were sampled along an east-west elevational transect (23.75 to 24.70 degrees S) through the driest sector to compare the relative structure of bacterial communities. Analysis of denaturing gradient gel electrophoresis (DGGE) profiles from each of the samples revealed that microbial communities from the extreme hyperarid core of the desert clustered separately from all of the remaining communities. Bands sequenced from DGGE profiles of two samples taken at a 22-month interval from this core region revealed the presence of similar populations dominated by bacteria from the Gemmatimonadetes and Planctomycetes phyla.

  7. VEGETATIVE GROWTH AND EARLY PRODUCTION OF SIX OLIVE CULTIVARS, IN SOUTHERN ATACAMA DESERT, CHILE

    Directory of Open Access Journals (Sweden)

    Freddy MORA

    2007-12-01

    Full Text Available Tree survival, early fruit production, vegetative growth and alternate bearing were examined in six different olive cultivars (Barnea, Biancolilla, Coratina, Empeltre, Koroneiki and Leccino under intensive agronomic conditions i southern Atacama Desert, in the Coquimbo Region of Chile. The cultivars were evaluated over four successive years and had a high survival rate (93% confi rming their potential for these dry-lands. Fruit production (recorded over the growing seasons 2002-2003, vegetative growth (2000-2003 and alternate bearing differed signifi cantly among cultivars. Olive selection in intensively managed planting at the southern part of the Atacama Desert depends on matching specifi c cultivars to sites on which they perform the best.

  8. Biodiversity of soil cyanobacteria in the hyper-arid Atacama Desert, Chile.

    Science.gov (United States)

    Patzelt, Dominik J; Hodač, Ladislav; Friedl, Thomas; Pietrasiak, Nicole; Johansen, Jeffrey R

    2014-08-01

    The cyanobacterial diversity of soils of the Atacama Desert (Chile) was investigated using 16S rRNA gene cloning/sequencing directly from soil samples and 16S rRNA gene sequencing from unialgal cultures. Within the hyper-arid Atacama Desert, one of the driest parts of the world, 10 sites with differing altitude and distance to the shore were sampled along a total air-line distance (from south to north) of ~1,100 km. Filamentous cyanobacteria belonging to Nostocophycideae and Synechococcophycideae were present. Oscillatoriophycideae exhibited the highest species richness among the subclasses of cyanobacteria, and included mostly filamentous species along with some coccoids (e.g., Chroococcidiopsis). Thirty species-level phylotypes could be recognized using a cut-off of 99% 16S rRNA sequence similarity within the 22 genera defined at 97% 16S rRNA sequence similarity. Eight of the 30 taxa could be detected by both clonal and culture sequences. Five taxa were observed only in cultures, whereas the cloning approach revealed 17 additional taxa, which might be in the collection but unsequenced, hard-to-cultivate, or entirely unculturable species using standard cultivation media. The Atacama Desert soils have a high diversity of phylotypes, among which are likely both new genera and new species awaiting characterization and description. PMID:26988453

  9. A new freshwater snail (Caenogastropoda: Cochliopidae) from the Atacama Desert, northern Chile.

    Science.gov (United States)

    Collado, Gonzalo A

    2015-01-01

    In the family Cochliopidae, Heleobia Stimpson, 1865 is the most speciose genus in South America, with about 90 species (Hershler & Thompson 1992; Cazzaniga 2011). A recent molecular and morphological analysis performed in northern Chile (Atacama Desert) showed that the previously undescribed springsnails from Aguada de Chorrillos belong to Heleobia (Collado et al. 2013). In this study I formally describe this new species. Although this paper does not treat morphology in detail, the anatomical characters, in combination with the previously published molecular data provides a strong basis for recognizing this population as a distinct species. PMID:25781755

  10. Distribution of prokaryotic genetic diversity in athalassohaline lakes of the Atacama Desert, Northern Chile.

    Science.gov (United States)

    Demergasso, Cecilia; Casamayor, Emilio O; Chong, Guillermo; Galleguillos, Pedro; Escudero, Lorena; Pedrós-Alió, Carlos

    2004-04-01

    Athalassohaline lakes are inland saline aquatic environments with ionic proportions quite different from the dissolved salts in seawater. Prokaryotes inhabiting athalassohaline environments are poorly known and very few of such places have been surveyed for microbial diversity studies around the world. We analyzed the planktonic bacterial and archaeal assemblages inhabiting several of these evaporitic basins in a remote and vast area in northern Chile by PCR-denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rRNA gene fragments. Most systems were springs and athalassohaline ponds in different saltflats of the Atacama Desert region, including Salar de Llamará (in the Central Depression), Salar de Atacama (in the Pre-Andean Depression) and Salar de Ascotán (in the Altiplano). Overall, we analyzed more than 25 samples from 19 different environments with strong gradients of altitude, qualitative ionic compositions and UV influence. Between 4 and 25 well-defined DGGE bands were detected for Bacteria in each sample, whereas Archaea ranged between 1 and 5. Predominant DGGE bands (defined by intensity and frequency of appearance) were excised from the gel and sequenced. Bacterial assemblages were dominated by the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum and a few Proteobacteria. There was a tendency for increasing contribution of CFB with higher salinities and altitude. Thus, CFB accounted for the major fraction of band intensity in the Ascotán samples and for lower percentages in Atacama and Llamará. When the distribution of particular CFB sequences was examined, there were several relatives of Psychroflexus torquis substituting each other as salinity changed in Ascotán. Another set of CFB sequences, very distantly related to Cytophaga marinovorus, was abundant in both Llamará and Atacama at salinities lower than 7%. Archaeal assemblages were dominated by uncultured haloarchaea distantly related to cultured strains mostly obtained from

  11. Photovoltaic performance and LCoE comparison at the coastal zone of the Atacama Desert, Chile

    International Nuclear Information System (INIS)

    Highlights: • Two PV technologies installed at the coastal zone of Atacama Desert were studied. • The energy yield improved up to 16% after cleaning. • The monthly performance ratio was determined and analyzed for a 21 month period. • The dust accumulated on modules produced a fall of the monthly performance ratio. • The Levelized Cost of Energy (LCoE) was calculated for a dirty and clean condition. - Abstract: Two photovoltaic technologies are compared with regard to the energy yield, performance ratio and their levelized cost of energy. Plants based on amorphous/microcrystalline silicon tandem thin films and multicrystalline silicon solar cells installed at the coastal zone of the Atacama Desert, Chile, were monitored for 21 months. This region can be one of the most suitable places for the use of solar energy due to the high solar radiation levels. However, the coastal desert climate may influence the performance of photovoltaic systems. The global tilted solar irradiation reached mean values of 8.6 kW h/m2 day in summer and 6 kW h/m2 day in winter demonstrating the high irradiation available. It came out that the performance ratio is influenced by the dust accumulation and the temperature associated to this place. The performance ratio of thin films decreased due to the dust accumulation at a rate from −4.2 to −3.7%/month for decreasing temperature and from −4.8 to −4.4%/month for increasing temperature. For multicrystalline silicon modules, the degradation rates were −2.4 to −1.8%/month for decreasing temperature, and −6.2 to −3.7%/month for increasing temperature. It was concluded that the electricity costs were 14.48 cents€/kW h and 15.65 cents€/kW h for thin film and mc-Si, respectively. Thus, the thin films had more benefit after cleaning than multicrystalline modules

  12. Molecular analysis of a 11 700-year-old rodent midden from the Atacama Desert, Chile

    Science.gov (United States)

    Kuch, M.; Rohland, N.; Betancourt, J.L.; Latorre, C.; Steppan, S.; Poinar, H.N.

    2002-01-01

    DNA was extracted from an 11 700-year-old rodent midden from the Atacama Desert, Chile and the chloroplast and animal mitochondrial DNA (mtDNA) gene sequences were analysed to investigate the floral environment surrounding the midden, and the identity of the midden agent. The plant sequences, together with the macroscopic identifications, suggest the presence of 13 plant families and three orders that no longer exist today at the midden locality, and thus point to a much more diverse and humid climate 11 700 years ago. The mtDNA sequences suggest the presence of at least four different vertebrates, which have been putatively identified as a camelid (vicuna), two rodents (Phyllotis and Abrocoma), and a cardinal bird (Passeriformes). To identify the midden agent, DNA was extracted from pooled faecal pellets, three small overlapping fragments of the mitochondrial cytochrome b gene were amplified and multiple clones were sequenced. These results were analysed along with complete cytochrome b sequences for several modern Phyllotis species to place the midden sequence phylogenetically. The results identified the midden agent as belonging to an ancestral P. limatus. Today, P. limatus is not found at the midden locality but it can be found 100 km to the north, indicating at least a small range shift. The more extensive sampling of modern Phyllotis reinforces the suggestion that P. limatus is recently derived from a peripheral isolate.

  13. Bacterial Diversity within the Extreme Arid Atacama Desert Soils of the Yungay Region, Chile

    Science.gov (United States)

    Connon, S. A.; Lester, E. D.; Shafaat, H. S.; Obenhuber, D. C.; Ponce, A.

    2006-12-01

    Surface and subsurface soil samples analyzed for this study were collected from the hyper-arid Yungay region of the Atacama Desert, Chile. This is the first report of microbial diversity from DNA extracted directly from these extremely desiccated soils. Our data shows that 94% of the 16S rRNA genes cloned from these soils belong to the Actinobacteria phylum. A 24-hour time course series showed a diurnal water activity (aw) cycle that peaked at 0.52 in the early predawn hours, and ranged from 0.08 0.01 during the day. All measured water activity values were below the level required for microbial growth or enzyme activity. Total organic carbon (TOC) levels in this region were just above the limits of detection and ranged from 220 660 μg/g of soil. Phospholipid fatty acid (PLFA) levels indicated cellular biomass ranging from 2 ×105 to 7 ×106 cell equivalents per gram of soil. The culturable counts were low with most samples showing no growth on standard plates of R2A medium; the highest single count was 47 colony forming units (CFU) per gram.

  14. Impact of empire expansion on household diet: the Inka in Northern Chile's Atacama Desert.

    Directory of Open Access Journals (Sweden)

    Sheila Dorsey Vinton

    Full Text Available The impact of expanding civilization on the health of American indigenous societies has long been studied. Most studies have focused on infections and malnutrition that occurred when less complex societies were incorporated into more complex civilizations. The details of dietary change, however, have rarely been explored. Using the analysis of starch residues recovered from coprolites, here we evaluate the dietary adaptations of indigenous farmers in northern Chile's Atacama Desert during the time that the Inka Empire incorporated these communities into their economic system. This system has been described as "complementarity" because it involves interaction and trade in goods produced at different Andean elevations. We find that as local farming societies adapted to this new asymmetric system, a portion of their labor had to be given up to the Inka elite through a corvée tax system for maize production. In return, the Inka system of complementarity introduced previously rare foods from the Andean highlands into local economies. These changes caused a disruption of traditional communities as they instituted a state-level economic system on local farmers. Combined with previously published infection information for the same populations under Inka rule, the data suggest that there may have been a dual health impact from disruption of nutrition and introduction of crowd disease.

  15. Impact of empire expansion on household diet: the Inka in Northern Chile's Atacama Desert.

    Science.gov (United States)

    Vinton, Sheila Dorsey; Perry, Linda; Reinhard, Karl J; Santoro, Calogero M; Teixeira-Santos, Isabel

    2009-01-01

    The impact of expanding civilization on the health of American indigenous societies has long been studied. Most studies have focused on infections and malnutrition that occurred when less complex societies were incorporated into more complex civilizations. The details of dietary change, however, have rarely been explored. Using the analysis of starch residues recovered from coprolites, here we evaluate the dietary adaptations of indigenous farmers in northern Chile's Atacama Desert during the time that the Inka Empire incorporated these communities into their economic system. This system has been described as "complementarity" because it involves interaction and trade in goods produced at different Andean elevations. We find that as local farming societies adapted to this new asymmetric system, a portion of their labor had to be given up to the Inka elite through a corvée tax system for maize production. In return, the Inka system of complementarity introduced previously rare foods from the Andean highlands into local economies. These changes caused a disruption of traditional communities as they instituted a state-level economic system on local farmers. Combined with previously published infection information for the same populations under Inka rule, the data suggest that there may have been a dual health impact from disruption of nutrition and introduction of crowd disease. PMID:19956668

  16. A 22,000-year record of monsoonal precipitation from northern Chile's Atacama Desert

    Science.gov (United States)

    Betancourt, J.L.; Latorre, C.; Rech, J.A.; Quade, Jay; Rylander, K.A.

    2000-01-01

    Fossil rodent middens and wetland deposits from the central Atacama Desert (22° to 24°S) indicate increasing summer precipitation, grass cover, and groundwater levels from 16.2 to 10.5 calendar kiloyears before present (ky B.P.). Higher elevation shrubs and summer-flowering grasses expanded downslope across what is now the edge of Absolute Desert, a broad expanse now largely devoid of rainfall and vegetation. Paradoxically, this pluvial period coincided with the summer insolation minimum and reduced adiabatic heating over the central Andes. Summer precipitation over the central Andes and central Atacama may depend on remote teleconnections between seasonal insolation forcing in both hemispheres, the Asian monsoon, and Pacific sea surface temperature gradients. A less pronounced episode of higher groundwater levels in the central Atacama from 8 to 3 ky B.P. conflicts with an extreme lowstand of Lake Titicaca, indicating either different climatic forcing or different response times and sensitivities to climatic change.

  17. Thermal biology of the fossorial rodent Ctenomys fulvus from the Atacama desert, northern Chile.

    Science.gov (United States)

    Cortés; Miranda; Rosenmann; Rau

    2000-12-01

    The Andean tuco-tuco, Ctenomys fulvus (Rodentia: Ctenomyidae) inhabits one of the most arid regions of the world, the Salar de Atacama, Northeast of Antofagasta, Chile (23 degrees 17'06"S, 68 degrees 05'43"W; 2.240 m.a.s.l). We found that a stable microclimate in burrows, a low evaporative water loss (EWL), and a diet of roots (59% water content) are the main factors that permit the survival of this fossorial species in harsh desert conditions. Large circadian variation in T(a) was observed above ground. Daily DeltaT(a) (T(a) max - T(a) min) = 37.9+/-0.2 degrees C in summer and in winter. In contrast, circadian variation of T(a) inside the burrows was only 5.8+/-0.5 degrees C in the same seasons. Relative humidity (RH) was 1.9-3.1% during the day, increasing to maximum values of 27% at night and early morning. Inside the burrows RH was higher and quite stable, ranging between 53.1 and 65%, independent of the time of day and season. EWL, measured between 10 and 25 degrees C, was low (1.26 mg/g h), and a moderate increase of 13-20% was observed at higher temperatures. The low EWL may prevent dehydration. However, because of the low heat loss capability, animals became hyperthermic (0.8-1.6 degrees C) in dry air at T(a)=30-35 degrees C. As T(a) during afternoon normally exceeded 35 degrees C, the microclimate of burrows provided the only way to avoid the lethal effects of hyperthermia. PMID:10880865

  18. Discovery and microbial content of the driest site of the hyperarid Atacama Desert, Chile.

    Science.gov (United States)

    Azua-Bustos, Armando; Caro-Lara, Luis; Vicuña, Rafael

    2015-06-01

    The Atacama Desert is the driest and oldest desert on Earth. Eleven years ago, the Yungay region was established as the driest site of this hyperarid desert and also close to the dry limit for life on Earth. Since then, much has been published about the extraordinary characteristics of this site and its pertinence as a Mars analogue model. However, as a result of a more systematic search in the Atacama here, we describe a new site, María Elena South (MES), which is much drier than Yungay. The mean atmospheric relative humidity (RH) at MES was 17.3%, with the RH of its soils remaining at a constant 14% at the depth of 1 m, a value that matches the lowest RH measurements taken by the Mars Science Laboratory at Gale Crater. Remarkably, we found a number of viable bacterial species in the soil profile at MES using a combination of molecular dependent and independent methods, unveiling the presence of life in the driest place on the Atacama Desert reported to date. PMID:25545388

  19. The Tale of Hyper-arid Pedogenesis-Two Comparing Sites in the Atacama Desert, Chile

    Science.gov (United States)

    Wang, F.; Seo, J.; Bowen, B.; Ochoa, R.; Michalski, G.

    2010-12-01

    The hyper-arid core of the Atacama Desert, Chile contains Mars-like soils that have extremely low levels of microorganisms and organic materials but high concentrations of unusual salts, providing an excellent terrestrial analog to Martian surface. This study presents two comparing sites: a 4 m-high incised paleosol at Chug-Chug field site and a 2 m-deep mining trench in the Baquedano region, to investigate pedogenic development in hyper-arid regions by performing geochemical and stable oxygen isotopic analysis on the whole set of profile samples collected at 4~5 cm vertical resolution. Geochemical data shows that both of these two sites are rich in chloride, nitrate and sulfate anions as well as sodium and calcium cations with molar ratios of Ca2+/SO42- and Na+/(NO3-+Cl-) close to 1, suggesting the common minerals are soda niter (NaNO3), halite (NaCl), gypsum (CaSO42H2O) and anhydrite (CaSO4). Significant Δ17O anomalies (17.0-20.4‰) are both observed in the NO3- salts from the two sites, indicating nitrate is mainly originated from the photochemically produced nitric acid in the atmosphere and pedogenic development may be dominated by the simple accumulation of atmospheric derived particles in a layer like fashion due to hyper-aridity. The average NO3-/Cl- molar ratio of 0.89 in the Baquedano site is lower than that of 1.13 in the Chug-Chug site, probably because the Baquedano site is closer to the ocean and submicron aerosols in clean marine air have lower NO3-/Cl- ratio than in preanthroprogenic continental aerosols. However, small aqueous activities like decadal rainfall and daily fog events may punctuate the accumulation and have a large influence on the evolution of saline minerals. For example, the most soluble ions, NO3-, Cl-, and Na+, are mostly conservative with depth, but their high concentration peaks are both observed at a depth of ~2 m in both sites, which can be due to the accumulation of atmospheric salts without leaching in an extremely dry

  20. Draft Genome Sequence of Hymenobacter sp. Strain AT01-02, Isolated from a Surface Soil Sample in the Atacama Desert, Chile

    DEFF Research Database (Denmark)

    Hansen, Anders Cai Holm; Paulino-Lima, Ivan Glaucio; Fujishima, Kosuke;

    2016-01-01

    Here, we report the 5.09-Mb draft genome sequence of Hymenobacter sp. strain AT01-02, which was isolated from a surface soil sample in the Atacama Desert, Chile. The isolate is extremely resistant to UV-C radiation and is able to accumulate high intracellular levels of Mn/Fe....

  1. Draft Genome Sequence of Hymenobacter sp. Strain AT01-02, Isolated from a Surface Soil Sample in the Atacama Desert, Chile

    OpenAIRE

    Hansen, Anders Cai Holm; Paulino-Lima, Ivan Glaucio; Fujishima, Kosuke; Rothschild, Lynn Justine; Jensen, Peter Ruhdal

    2016-01-01

    Here, we report the 5.09-Mb draft genome sequence of Hymenobacter sp. strain AT01-02, which was isolated from a surface soil sample in the Atacama Desert, Chile. The isolate is extremely resistant to UV-C radiation and is able to accumulate high intracellular levels of Mn/Fe.

  2. Draft Genome Sequence of Hymenobacter sp. Strain AT01-02, Isolated from a Surface Soil Sample in the Atacama Desert, Chile.

    Science.gov (United States)

    Holm Hansen, Anders Cai; Paulino-Lima, Ivan Glaucio; Fujishima, Kosuke; Rothschild, Lynn Justine; Jensen, Peter Ruhdal

    2016-01-01

    Here, we report the 5.09-Mb draft genome sequence of Hymenobacter sp. strain AT01-02, which was isolated from a surface soil sample in the Atacama Desert, Chile. The isolate is extremely resistant to UV-C radiation and is able to accumulate high intracellular levels of Mn/Fe. PMID:26868392

  3. 800,000-Year Record of Plate Boundary Earthquakes in the Atacama Desert, Northern Chile

    Science.gov (United States)

    Baker, A. M.; Owen, L. A.; Rech, J.; Allmendinger, R. W.

    2010-12-01

    Coseismic cracks preserved in the hyper-arid Atacama Desert of Northern Chile provide a unique record of the seismic history of the modern Andean forearc, which has generated the largest earthquakes on earth. Loveless et al. (2009) mapped more than 50,000 cracks on satellite imagery and, based on boundary element modeling, suggested that they indicate repeated rupture of approximately the same segment. But, what is the time frame of the repeated rupture and what is the long-term strain rate of the forearc due to this process? West of Salar Grande, five overlapping fan surfaces contain different densities of coseismic cracks, allowing for such an assessment. The fan surfaces are highly indurated with gypsum and salt, resulting in excellent preservation of these brittle features. All surfaces are underlain by a tuff ~4 m.y. old. Older surfaces consistently have more and larger cracks than younger surfaces. Locally, cracks cutting across multiple surfaces have distinctly different widths and morphologies. Density is the number of cracks present per given length and total opening is the sum of the widths along that same length. Both crack density and total opening on each surface show a positive relationship to relative age, supporting the previously anecdotal evidence for reactivation of cracks through time with multiple events. Fresh, centimeter-scale cracks are also present on all surfaces, further supporting that these features record a history rather than a singular event. Three of the five fan surfaces have sufficiently large quartz clasts for exposure dating using 10Be and 26Al, providing absolute ages to use in calculating strain rate due to cracking. The oldest surface is 800±100 ky old. Samples from active channels constrain inheritance of cosmogenic nuclides, and nuclide ratios suggest no significant burial. Strain rates calculated from total opening and surface age range from 1.3x10^-15s^-1 to 2.4x10^-15s^-1 across the three surfaces. For comparison, we

  4. Room temperature 57Fe Moessbauer spectroscopy of ordinary chondrites from the Atacama Desert (Chile): constraining the weathering processes on desert meteorites

    International Nuclear Information System (INIS)

    We report the results of a study on the weathering products of 21 meteorites found in the Atacama Desert (Chile) using room temperature 57Fe Moessbauer spectroscopy (MS). The meteorites are weathered ordinary chondrites (OCs) with unknown terrestrial ages and include the three chemical groups (H, L, and LL). We obtained the percentage of all the Fe-bearing phases for the primary minerals: olivine, pyroxene, troilite and Fe-Ni metal, and for the ferric alteration products (composed of the paramagnetic Fe3+ component and the magnetically ordered Fe3+ components) which gives the percentage of oxidation of the samples. From the Moessbauer absorption areas of these oxides, the terrestrial oxidation of the Atacama OC was found in the range from ∼5% to ∼60%. The amount of silicates as well as the opaques decreases at a constant rate with increasing oxidation level.

  5. Soils at the hyperarid margin: The isotopic composition of soil carbonate from the Atacama Desert, Northern Chile

    Science.gov (United States)

    Quade, Jay; Rech, Jason A.; Latorre, Claudio; Betancourt, Julio L.; Gleeson, Erin; Kalin, Mary T.K.

    2007-01-01

    We evaluate the impact of exceptionally sparse plant cover (0–20%) and rainfall (2–114 mm/yr) on the stable carbon and oxygen composition of soil carbonate along elevation transects in what is among the driest places on the planet, the Atacama Desert in northern Chile. δ13C and δ18O values of carbonates from the Atacama are the highest of any desert in the world. δ13C (VPDB) values from soil carbonate range from -8.2% at the wettest sites to +7.9% at the driest. We measured plant composition and modeled respiration rates required to form these carbonate isotopic values using a modified version of the soil diffusion model of [Cerling (1984) Earth Planet. Sci. Lett.71, 229–240], in which we assumed an exponential form of the soil CO2 production function, and relatively shallow (20–30 cm) average production depths. Overall, we find that respiration rates are the main predictor of the δ13C value of soil carbonate in the Atacama, whereas the fraction C3 to C4 biomass at individual sites has a subordinate influence. The high average δ13C value (+4.1%) of carbonate from the driest study sites indicates it formed&mdahs;perhaps abiotically—in the presence of pure atmospheric CO2. δ18O (VPDB) values from soil carbonate range from -5.9% at the wettest sites to +7.3% at the driest and show much less regular variation with elevation change than δ13C values. δ18O values for soil carbonate predicted from local temperature and δ18O values of rainfall values suggest that extreme (>80% in some cases) soil dewatering by evaporation occurs at most sites prior to carbonate formation. The effects of evaporation compromise the use of δ18O values from ancient soil carbonate to reconstruct paleoelevation in such arid settings.

  6. Dry Acid Deposition and Accumulation on the Surface of Mars and in the Atacama Desert, Chile

    Science.gov (United States)

    Quinn, R. C.; Zent, A. P.; Ehrenfruend, P.; Taylor, C. L.; McKay, C. P.; Garry, J. R. C.

    2005-01-01

    It has been discovered recently that soils from certain regions of the Chilean Atacama Desert have some characteristics that are similar to the surface materials tested by the Viking Landers. Navarro-Gonzalez et al. demonstrated that the quantity and diversity of heterotrophic bacteria increase as a function of local water availability in the Atacama, and that for some soil samples collected in the driest regions, no culturable bacteria could be isolated. Additionally, Navarro-Gonzalez et al. reported that pyrolysis-GCMS analysis of soils collected from these regions revealed extremely low levels of organic matter. Although the mechanism resulting in the low level of organics in these regions was not established by Navarro-Gonzalez, the condition of organic-depleted, near-sterile soil offers an interesting Earth analog of the martian surface material, as the Viking Gas Exchange (GEx) experiment and Labeled Release (LR) experiment were unable to demonstrate the presence of culturable bacteria, and the Viking pyrolysis- GCMS was unable to detect organic compounds.

  7. Ancient and Modern Salars of the Atacama Desert, Chile: A Terrestrial Analog for Evaporite Formation on Mars

    Science.gov (United States)

    Jungers, M. C.; Amundson, R.; Heimsath, A. M.; Christensen, P. R.; Edwards, C. S.

    2010-12-01

    The hyperarid (Atacama Desert of northern Chile is a widely accepted terrestrial analog for the surface of Mars. Sulfate and chloride deposits are present in uncommonly high abundances throughout the Atacama. The formation and preservation of these evaporite deposits are a direct result of the arid-hyperarid climate of the region from the Triassic to the present. Mars, too, is known for a long history of aridity. Remotely sensed data from THEMIS, TES, and analyses conducted during Mars landing missions have revealed the presence of sulfate and chloride deposits covering some portions of Mars’ surface. We synthesize remotely sensed (ASTER) data from the Atacama with field observations and sample analyses by laboratory thermal spectroscopy and portable XRF to inform how best to interpret signatures of sulfate and chloride deposits on Mars. We focus on two salars, one ancient (Salar de Llamara) and one modern (Salar de Atacama), to better understand how evaporites’ spectral and geochemical signatures may evolve through time. The oldest deposits of the Salar de Llamara are Miocene in age, while the Salar de Atacama continues to develop today. Compositionally, both salars’ surfaces are dominated by sulfate (gypsum and anhydrite) and chloride (halite) deposits. We selected sample sites according to compositional boundaries inferred from decorrelation stretches of thermal infrared (TIR) ASTER bands supplemented by previous field reconnaissance. We collected surface samples along transects from the core of the salars to their shorelines, intersecting zones ranging from predominantly sulfate or chloride to near equal mixtures of each composition. This transect approach to sampling allowed us to collect samples that incorporated a range of both geochemical compositions and processes fundamental to the spatial and temporal evolution of evaporite deposits. Preliminary results show promise in refining our ability to identify sulfates and chlorides using lab spectra, and

  8. Paleowetlands and regional climate change in the central Atacama Desert, northern Chile

    Science.gov (United States)

    Quade, Jay; Rech, Jason A.; Betancourt, Julio L.; Latorre, Claudio; Quade, Barbra; Rylander, Kate Aasen; Fisher, Timothy

    2008-05-01

    Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during two periods: 15,900 to ~ 13,800 and 12,700 to ~ 9700 cal yr BP. Dense concentrations of lithic artifacts testify to the presence of paleoindians around the wetlands late in the second wet phase (11,000?-9700 cal yr BP). Water tables dropped below the surface before 15,900 and since 8100 cal yr BP, and briefly between ~ 13,800 and 12,700 cal yr BP. This temporal pattern is repeated, with some slight differences, in rodent middens from the study area, in both paleowetland and rodent midden deposits north and south of the study area, and in lake level fluctuations on the adjacent Bolivian Altiplano. The regional synchroneity of these changes points to a strengthening of the South American Monsoon — which we term the "Central Andean Pluvial Event" — in two distinct intervals (15,900-13,800 and 12,700-9700 cal yr BP), probably induced by steepened SST gradients across the tropical Pacific (i.e., La Niña-like conditions).

  9. Life at the hyperarid margin: novel bacterial diversity in arid soils of the Atacama Desert, Chile

    Science.gov (United States)

    Neilson, Julia W.; Quade, Jay; Ortiz, Marianyoly; Nelson, William M.; Legatzki, Antje; Tian, Fei; LaComb, Michelle; Betancourt, Julio L.; Wing, Rod A.; Soderlund, Carol A.; Maier, Raina M.

    2012-01-01

    Nearly half the earth's surface is occupied by dryland ecosystems, regions susceptible to reduced states of biological productivity caused by climate fluctuations. Of these regions, arid zones located at the interface between vegetated semiarid regions and biologically unproductive hyperarid zones are considered most vulnerable. The objective of this study was to conduct a deep diversity analysis of bacterial communities in unvegetated arid soils of the Atacama Desert, to characterize community structure and infer the functional potential of these communities based on observed phylogenetic associations. A 454-pyrotag analysis was conducted of three unvegetated arid sites located at the hyperarid-arid margin. The analysis revealed communities with unique bacterial diversity marked by high abundances of novel Actinobacteria and Chloroflexi and low levels of Acidobacteria and Proteobacteria, phyla that are dominant in many biomes. A 16S rRNA gene library of one site revealed the presence of clones with phylogenetic associations to chemoautotrophic taxa able to obtain energy through oxidation of nitrite, carbon monoxide, iron, or sulfur. Thus, soils at the hyperarid margin were found to harbor a wealth of novel bacteria and to support potentially viable communities with phylogenetic associations to non-phototrophic primary producers and bacteria capable of biogeochemical cycling.

  10. Paleowetlands and regional climate change in the central Atacama Desert, northern Chile

    Science.gov (United States)

    Quade, Jay; Rech, Jason A.; Betancourt, Julio L.; Latorre, Claudio; Quade, Barbra; Rylander, Kate Aasen; Fisher, Timothy

    2008-01-01

    Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during two periods: 15,900 to ~ 13,800 and 12,700 to ~ 9700 cal yr BP. Dense concentrations of lithic artifacts testify to the presence of paleoindians around the wetlands late in the second wet phase (11,000?–9700 cal yr BP). Water tables dropped below the surface before 15,900 and since 8100 cal yr BP, and briefly between ~ 13,800 and 12,700 cal yr BP. This temporal pattern is repeated, with some slight differences, in rodent middens from the study area, in both paleowetland and rodent midden deposits north and south of the study area, and in lake level fluctuations on the adjacent Bolivian Altiplano. The regional synchroneity of these changes points to a strengthening of the South American Monsoon — which we term the "Central Andean Pluvial Event" — in two distinct intervals (15,900–13,800 and 12,700–9700 cal yr BP), probably induced by steepened SST gradients across the tropical Pacific (i.e., La Niña-like conditions).

  11. Urinary arsenic speciation profile in ethnic group of the Atacama desert (Chile) exposed to variable arsenic levels in drinking water.

    Science.gov (United States)

    Yáñez, Jorge; Mansilla, Héctor D; Santander, I Paola; Fierro, Vladimir; Cornejo, Lorena; Barnes, Ramón M; Amarasiriwardena, Dulasiri

    2015-01-01

    Ethnic groups from the Atacama Desert (known as Atacameños) have been exposed to natural arsenic pollution for over 5000 years. This work presents an integral study that characterizes arsenic species in water used for human consumption. It also describes the metabolism and arsenic elimination through urine in a chronically exposed population in northern Chile. In this region, water contained total arsenic concentrations up to 1250 μg L(-1), which was almost exclusively As(V). It is also important that this water was ingested directly from natural water sources without any treatment. The ingested arsenic was extensively methylated. In urine 93% of the arsenic was found as methylated arsenic species, such as monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)]. The original ingested inorganic species [As(V)], represent less than 1% of the total urinary arsenic. Methylation activity among individuals can be assessed by measuring primary [inorganic As/methylated As] and secondary methylation [MMA/DMA] indexes. Both methylation indexes were 0.06, indicating a high biological converting capability of As(V) into MMA and then MMA into DMA, compared with the control population and other arsenic exposed populations previously reported. PMID:25438126

  12. Metal mobilization by iron- and sulfur-oxidizing bacteria in a multiple extreme mine tailings in the Atacama Desert, Chile.

    Science.gov (United States)

    Korehi, H; Blöthe, M; Sitnikova, M A; Dold, B; Schippers, A

    2013-03-01

    The marine shore sulfidic mine tailings dump at the Chañaral Bay in the Atacama Desert, northern Chile, is characterized by extreme acidity, high salinity, and high heavy metals concentrations. Due to pyrite oxidation, metals (especially copper) are mobilized under acidic conditions and transported toward the tailings surface and precipitate as secondary minerals (Dold, Environ. Sci. Technol. 2006, 40, 752-758.). Depth profiles of total cell counts in this almost organic-carbon free multiple extreme environment showed variable numbers with up to 10(8) cells g(-1) dry weight for 50 samples at four sites. Real-time PCR quantification and bacterial 16S rRNA gene diversity analysis via clone libraries revealed a dominance of Bacteria over Archaea and the frequent occurrence of the acidophilic iron(II)- and sulfur-oxidizing and iron(III)-reducing genera Acidithiobacillus, Alicyclobacillus, and Sulfobacillus. Acidophilic chemolithoautotrophic iron(II)-oxidizing bacteria were also frequently found via most-probable-number (MPN) cultivation. Halotolerant iron(II)-oxidizers in enrichment cultures were active at NaCl concentrations up to 1 M. Maximal microcalorimetrically determined pyrite oxidation rates coincided with maxima of the pyrite content, total cell counts, and MPN of iron(II)-oxidizers. These findings indicate that microbial pyrite oxidation and metal mobilization preferentially occur in distinct tailings layers at high salinity. Microorganisms for biomining with seawater salt concentrations obviously exist in nature. PMID:23373853

  13. Investigation into mummies from the Atacama Desert, Chile: Did they suffer from arsenic poisoning?

    International Nuclear Information System (INIS)

    Full text: the foothills of the Andes. Despite its hostility, people have lived here for thousands of years, manifested by the discovery of mummies which are from Pre-Columbian times and can be as old as 1500 years. In addition, the water of the few oasis and rivers of this region can be highly contaminated by arsenic, which originates from geogenic sources. The work presented here aims on the question whether the people that lived in this region were exposed to arsenic in their drinking water. Arsenic is known for its acute toxicity when administered in high doses, but also its carcinogenic impact even in very low doses, and the WHO standard for maximum As concentration in drinking water was recently reduced to 10 μg/L. Arsenic exposure in people can be monitored in keratogenous material like hair, nails and skin. In addition, arsenic speciation in these tissues can be used to determine whether the As was metabolised in the body, enabling the differentiation from ingestion of As versus external contamination by either As present in the soil or any cosmetic/preservative treatment of the body prior or after death. The Atacama people traditionally buried their dead in shallow graves in the high regions of the altiplano, and the dry and cold climate set on a natural mummification, which leads to the fact that a huge amount of well preserved mummified remains can be found in the desert. Here, we investigate hair, skin and fingernail samples of up to 10 Mummies dated to approx. 500 years of age, for arsenic concentration and speciation of As, focusing on the determination whether these people may have suffered from As exposure through drinking water. Water sources around the find spots of the mummies were investigated for As concentration, and significant variations can be found for different water sources. In addition to arsenic speciation analysis using XANES and HPLC-ICPMS, stable isotope analysis was performed for C,N,O and H, revealing the source of food these

  14. Hydrogeochemistry and stable isotopes of ground and surface waters from two adjacent closed basins, Atacama Desert, northern Chile

    Science.gov (United States)

    Alpers, C.N.; Whittemore, D.O.

    1990-01-01

    The geochemistry and stable isotopes of groundwaters, surface waters, and precipitation indicate different sources of some dissolved constituents, but a common source of recharge and other constituents in two adjacent closed basins in the Atacama Desert region of northern Chile (24??15???-24??45???S). Waters from artesian wells, trenches, and ephemeral streams in the Punta Negra Basin are characterized by concentrations of Na>Ca>Mg and Cl ???SO4, with TDS Mg ??? Ca and SO4 > Cl, with TDS also Mg ??? Ca and SO4 > Cl, but with TDS up to 40 g/l. The deep mine waters have pH between 3.2 and 3.9, and are high in dissolved CO2 (??13 C = -4.8%PDB), indicating probable interaction with oxidizing sulfides. The deep mine waters have ??18O values of ???-1.8%.compared with values < -3.5??? for other Hamburgo Basin waters; thus the mine waters may represent a mixture of meteoric waters with deeper "metamorphic" waters, which had interacted with rocks and exchanged oxygen isotopes at elevated temperatures. Alternatively, the deep mine waters may represent fossil meteoric waters which evolved isotopically along an evaporative trend starting from values quite depleted in ??18O and ??Dd relative to either precipitation or shallow groundwaters. High I/Br ratios in the Hamburgo Basin waters and La Escondida mine waters are consistent with regionally high I in surficial deposits in the Atacama Desert region and may represent dissolution of a wind-blown evaporite component. Rain and snow collected during June 1984, indicate systematic ??18O and ??D fractionation with increasing elevation between 3150 and 4180 m a.s.l. (-0.21??.??18O and -1.7??.??D per 100 m). Excluding the deep mine waters from La Escondida, the waters from the Hamburgo and Punta Negra Basins have similar ??D and ??18O values and together show a distinct evaporative trend (??D = 5.0 ??18O - 20.2). Snowmelt from the central Andes Cordillera to the east is the most likely source of recharge to both basins. Some of the

  15. Spatial and temporal constraints on regional-scale groundwater flow in the Pampa del Tamarugal Basin, Atacama Desert, Chile

    Science.gov (United States)

    Jayne, Richard S.; Pollyea, Ryan M.; Dodd, Justin P.; Olson, Elizabeth J.; Swanson, Susan K.

    2016-08-01

    Aquifers within the Pampa del Tamarugal Basin (Atacama Desert, northern Chile) are the sole source of water for the coastal city of Iquique and the economically important mining industry. Despite this, the regional groundwater system remains poorly understood. Although it is widely accepted that aquifer recharge originates as precipitation in the Altiplano and Andean Cordillera to the east, there remains debate on whether recharge is driven primarily by near-surface groundwater flow in response to periodic flood events or by basal groundwater flux through deep-seated basin fractures. In addressing this debate, the present study quantifies spatial and temporal variability in regional-scale groundwater flow paths at 20.5°S latitude by combining a two-dimensional model of groundwater and heat flow with field observations and δ18O isotope values in surface water and groundwater. Results suggest that both previously proposed aquifer recharge mechanisms are likely influencing aquifers within the Pampa del Tamarugal Basin; however, each mechanism is operating on different spatial and temporal scales. Storm-driven flood events in the Altiplano readily transmit groundwater to the eastern Pampa del Tamarugal Basin through near-surface groundwater flow on short time scales, e.g., 100-101 years, but these effects are likely isolated to aquifers in the eastern third of the basin. In addition, this study illustrates a physical mechanism for groundwater originating in the eastern highlands to recharge aquifers and salars in the western Pampa del Tamarugal Basin over timescales of 104-105 years.

  16. Paleomagnetism and tectonics of the southern Atacama Desert (25-28 degrees S), northern Chile

    OpenAIRE

    Arriagada, C.; Roperch, Pierrick; Mpodozis, C.; Fernandez, R

    2006-01-01

    We report paleomagnetic results for 131 sites from the modern forearc of northern Chile (25 degrees S and 28 degrees S). Remanent magnetization in volcanic and intrusive rocks is mostly primary, while a secondary magnetization is observed in sedimentary rocks. Comparison of locality-mean directions with expected paleomagnetic directions indicates vertical axis rotations from -7.3 degrees +/- 21.6 degrees counterclockwise to 52.7 degrees +/- 17 degrees clockwise. Jurassic to Early Cretaceous r...

  17. Multiple Sulfate Isotopic Evidence on the Formation of Oxide Copper Ore at Spence, Atacama Desert, Northern Chile

    Science.gov (United States)

    Sun, T.; Bao, H.; Reich, M.; Palacios, C.

    2007-12-01

    In the Atacama Desert of northern Chile, one of the world's richest metallogenic provinces, porphyry copper deposits are characterized by the unique occurrence of atacamite in their oxidized zones. The origin and formation of the oxide zone of these copper deposits is, however, controversial. It was proposed that Cl-rich deep formation water pumping-up events along faults by earthquakes, after onset of the hyperaridity, were required (Cameron et al., 2007). Their model would imply that supplies of saline deep formation water from fractures to the surface should have left behind a homogeneous or fracture-controlled salt profile from surface down to the oxide zone. While no excluding the deep formation water model in other deposit, here we propose that, in our sampling region, the alternative saline source, which is critical for atacamite formation, could be locally evaporated groundwater, Cl-rich salts leached from arid surface by meteoric water, or brines from eastern salar basins at a time when the climate in northern Chile was changing from arid to hyperarid. At this climate transition, arid- requiring minerals such as atacamite in the oxide zone were formed and, more importantly, preserved upon evaporation beneath the surface alluvial deposits. Since salt accumulation at the surface remain active during hyperarid condition, our model would predict that water-soluble salt profile from surface to the oxide zone should have a characteristic pattern: salts with an atmospheric component on the surface gradually transitioning to salts of the oxide ore zone on the bottom and a mixing zone in between. To test these two alternative models, we focus on sulfate salts, one of the common water-soluble salts in arid environments. An added advantage is that sulfate accumulated on desert surface has a secondary atmospheric component that bears a unique triple oxygen isotope signature, easily distinguishable from sulfate formed by the oxidation of sulfide minerals at the oxide

  18. Bacterial Composition and Quantitation in the Yungay Region of the Atacama Desert, Chile

    Science.gov (United States)

    Fletcher, Lauren; Conley, Catharine A.; Ishkhanova, Galina; Kovacs, Gregory; Jordan, Jeanne; Cullings, Ken; Gomez-Silva, Benito; McKay, Christopher

    2006-01-01

    Voyager would have produced similar negative results if tested in the Yungay region (Navarro-Gonzales et al, 2003). However, the number of bacteria present per gr'am in the Yungay sands is not well-established, being below the detection limit of culture methods. For the past several years, this group has been analyzing Yungay sands by quantitative Polymerase Chain Reaction (qPCR), both in the lab and in the field, to establish protocols for counting bacteria. We use primers that detect a broad range of bacterial taxa, including both proteobacteria and firmicutes. Optimization of DNA extraction and qPCR analysis is critical for accurate counts. Comparison of qPCR results with PhosphoLipid Fatty Acid (PLFA)-analysis and other counting methods indicates that there are detectable bacteria in sand obtained from the upper few centimeters of the desert surface.

  19. Eroding and Inflating the Atacama Desert, Chile: Insights Through Cosmogenic 10-Be, 26-Al and 21-Ne

    Science.gov (United States)

    Heimsath, A. M.; Jungers, M. C.; Amundson, R.; Balco, G.; Shuster, D. L.

    2010-12-01

    Enigmas of the Atacama Desert are as abundant as the hypotheses formulated to explain them. This fascinating and extreme landscape attracts scientists from disparate disciplines, spawning remarkable insights into the connections between climate, tectonics, biota and landscape evolution. Recent work explores such connections on timescales ranging from millions to thousands of years. Both the timing of the onset of hyperaridity in the Atacama and its relationship to the uplift of the Andes are especially well-debated topics. Similarly enigmatic, but less widely studied, are the connections between the timing of hyperaridity and the surface morphology of the region. Specifically, the extent, nature, and timing of formation for the extensive salars across the Atacama are undeniably linked to the climate history of the region. Adjacent to the extensive salars are landscapes that appear to be shaped by processes more typically associated with temperate landscapes: rilling and gullying, extensive terrace deposition, steep fault scarps, landslide deposits, and extensive fan and paleosurface deposits. Our primary goal in this project is to establish chronologies and rates for the surface processes driving landscape evolution for two field regions in the Atacama. To achieve this goal we are also testing and expanding upon the burial dating methodology (Balco and Shuster, 2009) that couples the stable cosmogenic nuclide, 21Ne, with the radiogenic nuclides, 10Be and 26Al. Here we present new results from remarkably different field settings from the north-central Atacama. The southern region, inland from Antofagasta, is relatively well studied to determine how the onset of hyperaridity impacted water-driven processes. The northern region, north of the Rio Loa and Calama, differs most notably by the enormous basin fills of salt (e.g. Salar de Llamara and Salar Grande) and evidence of more extensive recently active salars. Across both regions we use in 10Be, 26Al, and 21Ne to

  20. Shoreline dating of the former Quillagua-Llamara Lake, N-Chile - Implications of global teleconnections to the hydrology of the Atacama Desert

    Science.gov (United States)

    Ritter, Benedikt; Dunai, Tibor; Stuart, Finlay; Wennrich, Volker; Melles, Martin

    2016-04-01

    Cosmogenic nuclide exposure dating of ancient lake-level shoreline terraces of the Quillagua-Llamara Lake in the central Atacama Desert (N-Chile) provides new insights in the paleohydrology of the driest desert on earth. The lake developed from a paleo-exohereic drainage system in the Central Depression, before it opened towards the Pacific and an endohereic drainage system became established due to incision by the Rio Loa. The duration of the lake stages was long enough to cut erosive shoreline terraces into exposed islands. These shoreline features are preserved due to 250 m uplift of islands (Cerro Soledad, Cerro Mogote). Exposure dating of the shorelines reveals the existence of pluvial lake stages in the Atacama Desert during parts of the Late Pliocene and several Pleistocene interglacials (MIS 7, 9, 11, possibly 31, 87-93). These interglacials at least partly coincide with episodes of strong sea-ice retreat or even collapse of the West Antarctic Ice Sheet. This correlation is traced back to dramatic changes in the oceanographic and atmospheric circulation system in the Equatorial-SE Pacific with implications for global climate. A strong reduction in West Antarctic sea ice, followed by a weakening of the Peru-Chile Current and reduced supply of cold water, may have enabled expansion of the Pacific Warm Pool and thus increased sea-surface temperatures along the west coast of South America. These long-lasting, El Niño-like conditions may have in turn decreased the temperature inversion and enabled moisture transport towards the western Andean flanks. Our findings are compatible with evidence from the ANDRILL 1B record from the Ross Sea, Antarctica, and warm-water faunal assemblages on marine shoreline terraces from northern Chile. Furthermore, the exposure ages of the pluvial lake stages narrow the maximum incision age the of Rio Loa canyon and break through the Coastal Cordillera, and imply rock uplift rates of isolated islands in the Central Depression in the

  1. Multi-annual climate in Parque Nacional Pan de Azúcar, Atacama Desert, Chile Clima multianual en el Parque Nacional Pan de Azúcar, Desierto de Atacama, Chile

    Directory of Open Access Journals (Sweden)

    MATTHEW V. THOMPSON

    2003-06-01

    Full Text Available The lomas formations of the Peruvian and Atacama deserts are characterized by both climatic and floristic spatial heterogeneity, as well as non-contiguous pockets of relatively distinct flora. We examined two distinct types of communities in Parque Nacional Pan de Azúcar in Chile, the low-elevation arroyo and bajada community, and the high-elevation fog-zone community. We determined the distribution with elevation of the dominant perennial plant species in a single arroyo community, as well as the distribution of associated climatic characteristics. Climatic conditions (including air temperature, relative humidity, and wind speed and direction were recorded from June, 1999, to March, 2001, for the arroyo, as well as for a medium-elevation inland site with little vegetation, and a high-elevation fog-zone site with copious vegetation. The fog layer, or camanchaca, derived from the marine inversion layer ubiquitous to the Peruvian and Atacama deserts was found to be more persistent, though weaker, during the summer months and somewhat more condensed and shallower in the winter months, with uncharacteristically dry air and high temperatures occurring at and above 400 m elevation during the late fall and early winter of 2000. The reduction or increase in the maximum elevation of the camanchaca or a change in the rainfall regime of the park may have broad implications for the distribution or even presence of certain species in Parque Nacional Pan de Azúcar. Vegetation patterns appear to be strongly dependent on inversion layer development, and perhaps on its subsidence during the winter. A number of species prevalent at low-elevation sites may have little advantage at a high-elevation foggy site, whereas the consistently high humidity at low elevations would be a boon to any desert plant accustomed to low precipitation. If we are to successfully assess the effects of changes in southern Pacific weather patterns, it will become necessary to more

  2. Biotechnological Applications Derived from Microorganisms of the Atacama Desert

    OpenAIRE

    2014-01-01

    The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications deriv...

  3. Isotopic evidence for the source of Ca and S in soil gypsum, anhydrite and calcite in the Atacama Desert, Chile

    Science.gov (United States)

    Rech, Jason A.; Quade, Jay; Hart, William S.

    The origin of pedogenic salts in the Atacama Desert has long been debated. Possible salt sources include in situ weathering at the soil site, local sources such as aerosols from the adjacent Pacific Ocean or salt-encrusted playas (salars), and extra-local atmospheric dust. To identify the origin of Ca and S in Atacama soil salts, we determined δ 34S and 87Sr/ 86Sr values of soil gypsum/anhydrite and 87Sr/ 86Sr values of soil calcite along three east-west trending transects. Our results demonstrate the strong influence of marine aerosols on soil gypsum/anhydrite development in areas where marine fog penetrates inland. Results from an east-west transect located along a breach in the Coastal Cordillera show that most soils within 90 km of the coast, and below 1300 m in elevation, are influenced by marine aerosols and that soils within 50 km, and below 800 m in elevation, receive >50% of Ca and S from marine aerosols (δ 34S values > 14‰ and 87Sr/ 86Sr values >0.7083). In areas where the Coastal Cordillera is >1200 m in elevation, however, coastal fog cannot penetrate inland and the contribution of marine aerosols to soils is greatly reduced. Most pedogenic salts from inland soils have δ 34S values between +5.0 to +8.0‰ and 87Sr/ 86Sr ratios between 0.7070 and 0.7076. These values are similar to average δ 34S and 87Sr/ 86Sr values of salts from local streams, lakes, and salars (+5.4 ±2‰ δ 34S and 0.70749 ± 0.00045 87Sr/ 86Sr) in the Andes and Atacama, suggesting extensive eolian reworking of salar salts onto the surrounding landscape. Ultimately, salar salts are precipitated from evaporated ground water, which has acquired its dissolved solutes from water-rock interactions (both high and low-temperature) along flowpaths from recharge areas in the Andes. Therefore, the main source for Ca and S in gypsum/anhydrite in non-coastal soils is indirect and involves bedrock alteration, not surficially on the hyperarid landscape, but in the subsurface by ground water

  4. Isotopic evidence for divergent diets and mobility patterns in the Atacama Desert, northern Chile, during the Late Intermediate Period (AD 900-1450).

    Science.gov (United States)

    Santana-Sagredo, Francisca; Lee-Thorp, Julia A; Schulting, Rick; Uribe, Mauricio

    2015-03-01

    The decline of the Tiwanaku state saw the emergence of two new cultures-Pica-Tarapacá and Atacama-during the Late Intermediate Period in northern Chile. Archeological evidence suggests that both groups practised maize agriculture and pastoralism, but that their interaction zones differed significantly. Marine resources are common at Pica-Tarapacá sites, even those far from coast, while Atacama sites in the desert oases and precordilleran area seem to have directed their networks towards the highlands. Here we apply stable carbon, nitrogen, and oxygen isotope analysis on human bone and enamel to test dietary patterns and residential mobility at two sites, Pica 8 and Quitor 6, representing the Pica-Tarapacá and Atacama cultures, respectively. Our results show that diet at the two sites indeed differed: significant but variable consumption of marine resources and maize is indicated at Pica 8, despite being an inland site, while diet at Quitor 6 was based mainly on terrestrial resources. The use of seabird guano and llama dung as fertilizers and extreme aridity may have contributed to the high nitrogen isotope values observed in Pica 8 humans. The δ(18) O values in Pica 8 individuals are generally lower than for Quitor in spite of its greater distance from the Andes. All three isotopes suggest the presence of at least five nonlocals in the 30 measured at Pica 8. This evidence for human mobility is consistent with the high levels of trade and interaction observed in the archeological record, and begins to quantify the degree of movement of specific individuals. PMID:25385676

  5. The Solar Spectrum in the Atacama Desert.

    Science.gov (United States)

    Cordero, R R; Damiani, A; Seckmeyer, G; Jorquera, J; Caballero, M; Rowe, P; Ferrer, J; Mubarak, R; Carrasco, J; Rondanelli, R; Matus, M; Laroze, D

    2016-01-01

    The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0-5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Izaña Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons. PMID:26932150

  6. The Solar Spectrum in the Atacama Desert

    Science.gov (United States)

    Cordero, R. R.; Damiani, A.; Seckmeyer, G.; Jorquera, J.; Caballero, M.; Rowe, P.; Ferrer, J.; Mubarak, R.; Carrasco, J.; Rondanelli, R.; Matus, M.; Laroze, D.

    2016-03-01

    The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0-5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Izaña Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons.

  7. Distribution of scytonemin in endolithic microbial communities from halite crusts in the hyperarid zone of the Atacama Desert, Chile.

    Science.gov (United States)

    Vítek, Petr; Jehlička, Jan; Ascaso, Carmen; Mašek, Vlastimil; Gómez-Silva, Benito; Olivares, Héctor; Wierzchos, Jacek

    2014-11-01

    Scytonemin, a UV-screening molecule produced by certain Cyanobacteria to protect against harmful UV radiation, was studied in endolithic cyanobacterial colonies in the halite crust from one of the driest places on Earth - the hyperarid zone of the Atacama Desert. The distribution of the pigment within the evaporitic crust was studied in detail by various independent analytical methods: Raman spectroscopy (including Raman imaging); advanced microscopic observations (fluorescence microscopy, confocal laser scanning microscopy, low-temperature scanning electron microscopy); and spectrophotometric analyses. The differences in scytonemin biosynthesis were mapped within the colonized interior layers, which can be divided into scytonemin-rich and scytonemin-poor zones. A 532 nm laser for excitation proved to be an ideal excitation source with which to observe the relative content of scytonemin within a particular cell aggregate, as well as between different cell aggregates; based on the scytonemin/carotenoid Raman signal intensity ratio of selected corroborative bands for these two compounds. Significantly, scytonemin was found to accumulate within a decayed biomass in the surface portions of the halite crust. These were found to be highly enriched in both the absolute scytonemin content (as documented by UV/VIS spectrophotometry) and its content relative to other pigments associated with the cyanobacterial cells (e.g. carotenoids and chlorophyll). PMID:25056905

  8. Cloud optical depth from total and UV solar irradiance measurements at two sites of the Atacama Desert in Chile

    Science.gov (United States)

    Luccini, Eduardo; Rivas, Miguel; Rojas, Elisa

    2016-06-01

    The visible cloud optical depth (COD) for overcast stratocumulus was estimated at Arica (18.47°S, 70.31°W, 20 m above sea level (asl)) and Poconchile (18.45°S, 70.07°W, 560 m asl), northernmost Chilean sites distant about 30 km in the Atacama Desert, during morning hours for days in which cloudiness dissipates giving cloudless afternoons, from 10 min averaged measurements of total shortwave solar irradiance (ToSI) and ultraviolet solar irradiance (UVSI) during the period 2002-2005. One-dimensional radiative transfer model calculations were made to establish a theoretical relationship between the visible COD, the cloud effective transmittance in both ToSI (CETTo) and UVSI (CETUV), and the solar zenith angle (SZA). It is used to estimate COD from the previously measured CET by Luccini et al. (2011). Measurements in both ToSI and UVSI broadband ranges showed to be reliable to determine the visible COD within this frame. Overcast COD at the coastal site of Arica (typical COD ~ 15) is slightly larger than at the inland site of Poconchile (typical COD ~ 11). Maximum sensitivity of the retrieved CODs was found to variations in the cloud droplet effective radius, surface albedo and aerosol optical depth in both ranges, and in the total ozone column additionally in UVSI. The obtained CODs are linearly related but are higher compared with those from two other parametric methods using the same data. A simple rational expression of CET as a function of COD enables to estimate a mean (spectral and regional) surface albedo in each range that is in turn applicable to fit appropriately the ratio CETTo/CETUV. Instantaneous overpass MODIS-Terra satellite COD at 660 nm show a good agreement with simultaneous (within ± 5 min) ground-derived COD at both sites.

  9. The Solar Spectrum in the Atacama Desert

    OpenAIRE

    R.R Cordero; Damiani, A.; G. Seckmeyer; Jorquera, J.; Caballero, M; Rowe, P.; Ferrer, J; Mubarak, R.; Carrasco, J.; R. Rondanelli; Matus, M.; Laroze, D.

    2016-01-01

    The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from ...

  10. Molecular preservation in halite- and perchlorate-rich hypersaline subsurface deposits in the Salar Grande basin (Atacama Desert, Chile): Implications for the search for molecular biomarkers on Mars

    Science.gov (United States)

    FernáNdez-Remolar, D. C.; Chong-DíAz, G.; RuíZ-Bermejo, M.; Harir, M.; Schmitt-Kopplin, P.; Tziotis, D.; Gómez-OrtíZ, D.; GarcíA-Villadangos, M.; MartíN-Redondo, M. P.; Gómez, F.; RodríGuez-Manfredi, J. A.; Moreno-Paz, M.; de Diego-Castilla, G.; EcheverríA, A.; Urtuvia, V. N.; Blanco, Y.; Rivas, L.; Izawa, M. R. M.; Banerjee, N. R.; Demergasso, C.; Parro, V.

    2013-06-01

    Similarities between the Atacama Desert (Chile) and Mars include extreme aridity, highly oxidizing chemistry, and intense ultraviolet radiation that promoted the photochemical production of perchlorates and nitrates. Concentration of these ions under hyperarid conditions led to the formation of nitrate- and perchlorate-bearing deposits in ephemeral lakes, followed by later deposition of chlorides and sulfates. At some locations, such as the Salar Grande, hypersaline deposits have remained unaltered for millions of years. We conducted a drilling campaign in deposits of the Salar to characterize the preservation state of biological molecules. A 5 m deep discontinuous core was recovered and subjected to multitechnique analysis including the antibody microarray-based biosensor LDChip300 and the SOLID (Signs Of Life Detector) instrument, complemented by geophysical, mineralogical, geochemical, and molecular analysis. We identified two units based on the mineralogy: the upper one, from the surface to ~320 cm depth characterized by a predominance of halite and anhydrite, and the lower one, from 320 to 520 cm, with a drop in halite and anhydrite and an enrichment in nitrate and perchlorate. Organic compounds including biomolecules were detected in association with the different depositional and mineralogical units, demonstrating the high capacity for molecular preservation. Hypersaline environments preserve biomolecules over geologically significant timescales; therefore, salt-bearing materials should be high-priority targets for the search for evidence of life on Mars.

  11. Macaria mirthae Vargas et al (Lepidoptera: Geometridae): Confirmation of the Use of an Invasive Host Plant in the Northern Atacama Desert of Chile Based on DNA Barcodes.

    Science.gov (United States)

    Rivera-Cabello, D; Huanca-Mamani, W; Vargas, H A

    2015-08-01

    Macaria mirthae Vargas et al (Lepidoptera: Geometridae) is a geometrid moth native to the northern Atacama Desert of Chile. Its oligophagous larvae are associated with native hosts of the plant family Fabaceae, the most important of which is Acacia macracantha. The invasive tree Leucaena leucocephala (Fabaceae) was recently recorded as a host plant for M. mirthae based on morphology. The taxonomic status of larvae collected on A. macracantha and L. leucocephala was assessed using sequences of the DNA barcode fragment of the cytochrome c oxidase subunit I (COI) gene. Genetic divergence between samples from the host plants was found to be 0%-0.8% (Kimura 2-parameter model). Neighbor-joining and maximum likelihood analyses were also performed, including additional barcode sequences of Neotropical geometrid moths from GenBank and BOLD databases. Sequences of the larvae from both host plants clustered in a single clade with high statistical support in both analyses. Based on these results, it is concluded that M. mirthae has effectively expanded its host range and its larvae are currently feeding on the exotic tree L. leucocephala. Additionally, the importance of this new host association in a highly disturbed habitat is briefly discussed in terms of the field biology of this native geometrid moth. PMID:26174961

  12. Stable isotopic composition of soil calcite (O, C) and gypsum (S) overlying Cu deposits in the Atacama Desert, Chile: Implications for mineral exploration, salt sources, and paleoenvironmental reconstruction

    International Nuclear Information System (INIS)

    Highlights: ► We collected soils overlying two porphyry copper deposits and a pampa, Atacama Desert, Chile. ► δ18O for calcite over fracture zones at the Spence deposit suggests involvement of earthquake-induced groundwater. ► S isotopes in gypsum at Spence also indicates involvement of groundwater, consistent with elevated Cu, Se, I. ► At Gaby Sur and Tamarugal, S isotopes cannot distinguish sulfur of porphyry from redeposited sulfate from interior salars. ► The three sites studied have had different histories of salt accumulation and display variable influence of groundwater. - Abstract: Soils overlying two porphyry Cu deposits (Spence, Gaby Sur) and the Pampa del Tamarugal, Atacama Desert, Northern Chile were collected in order to investigate the extent to which saline groundwaters influence “soil” chemistry in regions with thick Miocene and younger sediment cover. Soil carbonate (calcite) was analyzed for C and O isotopes and pedogenic gypsum for S isotopes. Soil calcite is present in all soils at the Spence deposit, but increases volumetrically above two fracture zones that cut the Miocene gravels, including gravels that overlie the deposit. The C isotope composition of carbonate from the soils overlying fracture zones is indistinguishable from pedogenic carbonate elsewhere at the Spence deposit; all δ13CVPDB values fall within a narrow range (1.40–4.23‰), consistent with the carbonate having formed in equilibrium with atmospheric CO2. However, δ18OVPDB for carbonate over both fracture zones is statistically different from carbonate elsewhere (average δ18OVPDB = 0.82‰ vs. −2.23‰, respectively), suggesting involvement of groundwater in their formation. The composition of soils at the Tamarugal anomaly has been most strongly affected by earthquake-related surface flooding and evaporation of groundwater; δ13CVPDB values (−4.28‰ to −2.04‰) are interpreted to be a mixture of dissolved inorganic C (DIC) from groundwater and

  13. Microbial colonisation of chasmoendolithic habitats in the hyper-arid zone of the Atacama Desert

    OpenAIRE

    Diruggiero, J.; J. Wierzchos; C. K. Robinson; Souterre, T.; J. Ravel; Artieda, O.; V. Souza-Egipsy; C. Ascaso

    2013-01-01

    Efforts in searching for microbial life in the driest part of Atacama Desert, Chile, revealed a small number of lithic habitats that can be considered as environmental refuges for life. In this study, we describe for the first time chasmoendolithic colonisation of fissures and cracks of rhyolite-gypsum and calcite rocks collected in the hyper-arid zone of the desert. The use of high-throughput sequencing revealed that the Atacama rock communities comprised a few dominant phylotypes and a numb...

  14. Intelligent Rover Execution for Detecting Life in the Atacama Desert

    Science.gov (United States)

    Baskaran, Vijayakumar; Muscettola, Nicola; Rijsman, David; Plaunt, Chris; Fry, Chuck

    2006-01-01

    On-board supervisory execution is crucial for the deployment of more capable and autonomous remote explorers. Planetary science is considering robotic explorers operating for long periods of time without ground supervision while interacting with a changing and often hostile environment. Effective and robust operations require on-board supervisory control with a high level of awareness of the principles of functioning of the environment and of the numerous internal subsystems that need to be coordinated. We describe an on-board rover executive that was deployed on a rover as past of the "Limits of Life in the Atacama Desert (LITA)" field campaign sponsored by the NASA ASTEP program. The executive was built using the Intelligent Distributed Execution Architecture (IDEA), an execution framework that uses model-based and plan-based supervisory control of its fundamental computational paradigm. We present the results of the third field experiment conducted in the Atacama desert (Chile) in August - October 2005.

  15. Late Quaternary history of the Atacama Desert

    Science.gov (United States)

    Latorre, Claudio; Betancourt, Julio L.; Rech, Jason A.; Quade, Jay; Holmgren, Camille; Placzek, Christa; Maldonado, Antonio; Vuille, Mathias; Rylander, Kate A.

    2005-01-01

    Of the major subtropical deserts found in the Southern Hemisphere, the Atacama Desert is the driest. Throughout the Quaternary, the most pervasive climatic influence on the desert has been millennial-scale changes in the frequency and seasonality of the scant rainfall, and associated shifts in plant and animal distributions with elevation along the eastern margin of the desert. Over the past six years, we have mapped modern vegetation gradients and developed a number of palaeoenvironmental records, including vegetation histories from fossil rodent middens, groundwater levels from wetland (spring) deposits, and lake levels from shoreline evidence, along a 1200-kilometre transect (16–26°S) in the Atacama Desert. A strength of this palaeoclimate transect has been the ability to apply the same methodologies across broad elevational, latitudinal, climatic, vegetation and hydrological gradients. We are using this transect to reconstruct the histories of key components of the South American tropical (summer) and extratropical (winter) rainfall belts, precisely at those elevations where average annual rainfall wanes to zero. The focus has been on the transition from sparse, shrubby vegetation (known as the prepuna) into absolute desert, an expansive hyperarid terrain that extends from just above the coastal fog zone (approximately 800 metres) to more than 3500 metres in the most arid sectors in the southern Atacama.

  16. Paleohydrologic evolution and geochemical dynamics of cumulative supergene metal enrichment at La Escondida, Atacama Desert, northern Chile

    Science.gov (United States)

    Alpers, C.N.; Brimhall, G.H.

    1989-01-01

    Quantitative limonite mapping within the leached capping of the porphyry copper deposit at La Escondida, Chile, permits reconstruction of the paleohydrologic and chemical evolution of a well-developed supergene ore-forming system. The mineralogy, textures, and relative abundance of supergene limonite minerals (hematite, goethite, and jarosite) are used to reconstruct the former ratio of pyrite to chalcocite and the preoxidation copper grade based on empirical limonite sulfide correlations. Evidence for cumulative downward enrichment in vertical profiles through leached capping allows quantitative analysis of chemical mass balance in dynamic supergene systems. Slopes of linear regressions for profiles of reconstructed enriched copper grades vs. depth indicate lateral fluxes into or out of a given vertical profile. -from Authors

  17. A review of the non-bulimulid terrestrial Mollusca from the Region of Atacama, northern Chile

    OpenAIRE

    Juan Francisco Araya; Ricardo Catalán

    2014-01-01

    Abstract Terrestrial mollusca are sparsely studied in Chile and, for the first time, a formal record of the diversity of land snails in northern Chile is reported. Coastal and desertic areas in the Region of Atacama, in the border of the Atacama desert and the Pacific Ocean, were surveyed with the aim to describe the presence and distribution of this poorly known fauna. Of the fourteen species recorded, the geographic distribution records for nine species are extended, and some taxa are recor...

  18. ENSO effects on primary productivity in Southern Atacama desert

    OpenAIRE

    Squeo, F. A.; Tracol, Y.; López, D.; J. R. Gutiérrez; A. M. Cordova; Ehleringer, J. R.

    2006-01-01

    In the winter-rain southern Atacama Desert of the Coquimbo Region of Chile, El Niño - Southern Oscillation (ENSO) events modulate primary productivity. In this region, there are important changes in water availability between La Niña (dry) and El Niño (rainy) years. Using inter-annual comparisons of LANDSAT images from 30° to 31° S latitude, we observed changes in primary productivity between dry and rainy years at the regional level. There were also s...

  19. Assessing water stress of desert vegetation using remote sensing : the case of the Tamarugo forest in the Atacama Desert (Northern Chile)

    NARCIS (Netherlands)

    Chávez Oyanadel, R.O.

    2014-01-01

    Water stress assessment of natural vegetation plays a key role in water management of desert ecosystems. It allows scientists and managers to relate water extraction rates to changes in vegetation water condition, and consequently to define safe water extraction rates for maintaining a healthy ecosy

  20. Assessing water stress of desert vegetation using remote sensing : the case of the Tamarugo forest in the Atacama Desert (Northern Chile)

    OpenAIRE

    Chávez Oyanadel, R.O.

    2014-01-01

    Water stress assessment of natural vegetation plays a key role in water management of desert ecosystems. It allows scientists and managers to relate water extraction rates to changes in vegetation water condition, and consequently to define safe water extraction rates for maintaining a healthy ecosystem. Previous research has shown that optical remote sensing constitutes a powerful tool for assessing vegetation water stress due to its capability of quantitatively estimating important paramete...

  1. Biotechnological Applications Derived from Microorganisms of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    Armando Azua-Bustos

    2014-01-01

    Full Text Available The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development.

  2. Draft Genome Sequence of a Bacillus Bacterium from the Atacama Desert Wetlands Metagenome

    OpenAIRE

    Vilo, Claudia; Galetovic, Alexandra; Araya, Jorge E.; Gómez-Silva, Benito; Dong, Qunfeng

    2015-01-01

    We report here the draft genome sequence of a Bacillus bacterium isolated from the microflora of Nostoc colonies grown at the Andean wetlands in northern Chile. We consider this genome sequence to be a molecular tool for exploring microbial relationships and adaptation strategies to the prevailing extreme conditions at the Atacama Desert.

  3. Draft Genome Sequence of a Bacillus Bacterium from the Atacama Desert Wetlands Metagenome.

    Science.gov (United States)

    Vilo, Claudia; Galetovic, Alexandra; Araya, Jorge E; Gómez-Silva, Benito; Dong, Qunfeng

    2015-01-01

    We report here the draft genome sequence of a Bacillus bacterium isolated from the microflora of Nostoc colonies grown at the Andean wetlands in northern Chile. We consider this genome sequence to be a molecular tool for exploring microbial relationships and adaptation strategies to the prevailing extreme conditions at the Atacama Desert. PMID:26294639

  4. In situ metabolism in halite endolithic microbial communities of the hyperarid Atacama Desert

    OpenAIRE

    Davila, Alfonso F.; Ian eHawes; Jonathan eGarcía Araya; Diego R Gelsinger; Jocelyne eDiRuggiero; Carmen eAscaso; Anne eOsano; Jacek eWierzchos

    2015-01-01

    The Atacama Desert of northern Chile is one of the driest regions on Earth, with areas that exclude plants and where soils have extremely low microbial biomass. However, in the driest parts of the desert there are microorganisms that colonize the interior of halite nodules in fossil continental evaporites, where they are sustained by condensation of atmospheric water triggered by the salt substrate. Using a combination of in situ observations of variable chlorophyll fluorescence and controlle...

  5. Bioremediation of contaminated mixtures of desert mining soil and sawdust with fuel oil by aerated in-vessel composting in the Atacama Region (Chile)

    International Nuclear Information System (INIS)

    Since early 1900s, with the beginning of mining operations and especially in the last decade, small, although repetitive spills of fuel oil had occurred frequently in the Chilean mining desert industry during reparation and maintenance of machinery, as well as casual accidents. Normally, soils and sawdust had been used as cheap readily available sorbent materials of spills of fuel oil, consisting of complex mixtures of aliphatic and aromatic hydrocarbons. Chilean legislation considers these fuel oil contaminated mixtures of soil and sawdust as hazardous wastes, and thus they must be contained. It remains unknown whether it would be feasible to clean-up Chilean desert soils with high salinity and metal content, historically polluted with different commercial fuel oil, and contained during years. Thus, this study evaluated the feasibility of aerated in-vessel composting at a laboratory scale as a bioremediation technology to clean-up contaminated desert mining soils (fuel concentration > 50,000 mg kg-1) and sawdust (fuel concentration > 225,000 mg kg-1) in the Atacama Region. The composting reactors were operated using five soil to sawdust ratios (S:SD, 1:0, 3:1, 1:1, 1:3, 0:1, on a dry weight basis) under mesophilic temperatures (30-40 deg. C), constant moisture content (MC, 50%) and continuous aeration (16 l min-1) during 56 days. Fuel oil concentration and physico-chemical changes in the composting reactors were monitored following standard procedures. The highest (59%) and the lowest (35%) contaminant removals were observed in the contaminated sawdust and contaminated soil reactors after 56 days of treatment, respectively. The S:SD ratio, time of treatment and interaction between both factors had a significant effect (p < 0.050) on the contaminant removal. The results of this research indicate that bioremediation of an aged contaminated mixture of desert mining soil and sawdust with fuel oil is feasible. This study recommends a S:SD ratio 1:3 and a correct

  6. Use of a novel rover-mounted fluorescence imager and fluorescent probes to detect biological material in the Atacama Desert in daylight

    OpenAIRE

    Weinstein, S; Pane, D.; Warren-Rhodes, K.; Cockell, C; Ernst, L. A.; Minkley, E.; Fisher, G.; Emani, S.; Wettergreen, D. S.; Wagner, M.; Cabrol, J. N.; Waggoner, A S

    2005-01-01

    We deployed our fluorescence imaging system which detects fluorescence signals from sparse microorganisms and biofilms on Carnegie Mellon University’s autonomous rover Zoë. The results of the 2004 Atacama Desert field season, in Chile, are discussed.

  7. Perchlorate levels in soil and waters from the Atacama Desert.

    Science.gov (United States)

    Calderón, R; Palma, P; Parker, D; Molina, M; Godoy, F A; Escudey, M

    2014-02-01

    Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 μg/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 μg/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 μg/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 μg/L) for drinking. PMID:24165784

  8. Novel water source for endolithic life in the hyperarid core of the Atacama Desert

    OpenAIRE

    Wierzchos, J.; Davila, A. F.; I. M. Sánchez-Almazo; Hajnos, M.; R. Swieboda; Ascaso, C.

    2012-01-01

    The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most life-limited place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here, we show tha...

  9. Fungi associated with rocks of the Atacama Desert: taxonomy, distribution, diversity, ecology and bioprospection for bioactive compounds

    Science.gov (United States)

    This study assessed the diversity of fungi living in rocks from different altitudes in the Atacama Desert, Chile. Eighty-one fungal isolates obtained were identified as 21 species of 12 genera from Ascomycota using molecular techniques. Cladosporium halotolerans, Penicillium chrysogenum and Penicill...

  10. Calcium Sulfate in Atacama Desert Basalt: A Possible Analog for Bright Material in Adirondack Basalt, Gusev Crater

    Science.gov (United States)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    The Atacama Desert in northern Chile is one of the driest deserts on Earth (calcium sulfate (Ca-SO4) which was later confirmed by SEM/EDS analysis. This work examines the Ca-SO4 of Atacama basalt in an effort to provide insight into the possible nature of the bright material in the Adirondack basalt of Gusev Crater. The objectives of this work are to (i) discuss variations in Ca-SO4 crystal morphology in the vesicles and (ii) examine the Ca-SO4 interaction(s) with the basalt interior.

  11. Development of Ground and Remotely Based Evaporation Measurements at the Salar de Atacama, Northern Chile

    Science.gov (United States)

    Kampf, S. K.; Tyler, S. W.; Menz, S. F.; Muñoz, J. F.; Astete, C. O.

    2001-12-01

    Evaporation represents an important component of the water budget in desert playa lakes, and accurate spatial and temporal assessment of evaporation rates has the potential to greatly improve the accuracy of hydrologic models in such environments. To this end, evaporation at the Salar de Atacama, a large playa in the Atacama Desert of northern Chile, has been examined at a variety of spatial and temporal scales. Previous investigators have measured evaporation from the Salar using lysimeters and Bowen Ratio stations and have found that actual evaporation rates in much of the playa are extremely low (Salar are presented along with an assessment of the ability of ASTER imagery to provide accurate measurements of evaporation rates in playa environments.

  12. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave

    Science.gov (United States)

    Azua-Bustos, A.; Gonzalez-Silva, C.; Mancilla, R.A.; Salas, L.; Palma, R.E.; Wynne, J.J.; McKay, C.P.; Vicuna, R.

    2009-01-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert. ?? Springer Science + Business Media, LLC 2009.

  13. Salt deliquescence drives photosynthesis in the hyperarid Atacama Desert.

    Science.gov (United States)

    Davila, Alfonso F; Hawes, Ian; Ascaso, Carmen; Wierzchos, Jacek

    2013-08-01

    Endolithic cyanobacteria are found in halite nodules in the hyperarid core of the Atacama Desert. Using Pulse Amplitude Modulated Fluorometry, we show here that photosynthetic systems of these cyanobacteria become active when the relative humidity rises above 70% and the salt becomes wet by way of deliquescence. This is the first evidence of active metabolism in the hyperarid core of the Atacama, and supports the view of a microbial community sustained by deliquescence. Our results expand the water activity envelope of life on Earth. PMID:23864573

  14. Dynamics within geyser conduits, and sensitivity to environmental perturbations: Insights from a periodic geyser in the El Tatio geyser field, Atacama Desert, Chile

    Science.gov (United States)

    Munoz-Saez, Carolina; Manga, Michael; Hurwitz, Shaul; Rudolph, Maxwell L.; Namiki, Atsuko; Wang, Chi-Yuen

    2015-02-01

    Despite more than 200 years of scientific study, the internal dynamics of geyser systems remain poorly characterized. As a consequence, there remain fundamental questions about what processes initiate and terminate eruptions, and where eruptions begin. Over a one-week period in October 2012, we collected down-hole measurements of pressure and temperature in the conduit of an exceptionally regular geyser (132 s/cycle) located in the Chilean desert. We identified four stages in the geyser cycle: (1) recharge of water into the conduit after an eruption, driven by the pressure difference between water in the conduit and in a deeper reservoir; (2) a pre-eruptive stage that follows the recharge and is dominated by addition of steam from below; (3) the eruption, which occurs by rapid boiling of a large mass of water at the top of the water column, and decompression that propagates boiling conditions downward; and (4) a relaxation stage during which pressure and temperature decrease until conditions preceding the recharge stage are restored. Eruptions are triggered by the episodic addition of steam coming from depth, suggesting that the dynamics of the eruptions are dominated by geometrical and thermodynamic complexities in the conduit and reservoir. Further evidence favoring the dominance of internal processes in controlling periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).

  15. Dynamics within geyser conduits, and sensitivity to environmental perturbations: insights from a periodic geyser in the El Tatio Geyser Field, Atacama Desert, Chile

    Science.gov (United States)

    Munoz-Saez, Carolina; Manga, Michael; Hurwitz, Shaul; Rudolph, Maxwell L.; Namiki, Atsuko; Wang, Chi-Yuen

    2015-01-01

    Despite more than 200 years of scientific study, the internal dynamics of geyser systems remain poorly characterized. As a consequence, there remain fundamental questions about what processes initiate and terminate eruptions, and where eruptions begin. Over a one-week period in October 2012, we collected down-hole measurements of pressure and temperature in the conduit of an exceptionally regular geyser (132 s/cycle) located in the Chilean desert. We identified four stages in the geyser cycle: (1) recharge of water into the conduit after an eruption, driven by the pressure difference between water in the conduit and in a deeper reservoir; (2) a pre-eruptive stage that follows the recharge and is dominated by addition of steam from below; (3) the eruption, which occurs by rapid boiling of a large mass of water at the top of the water column, and decompression that propagates boiling conditions downward; (4) a relaxation stage during which pressure and temperature decrease until conditions preceding the recharge stage are restored. Eruptions are triggered by the episodic addition of steam coming from depth, suggesting that the dynamics of the eruptions are dominated by geometrical and thermodynamic complexities in the conduit and reservoir. Further evidence favoring the dominance of internal processes in controlling periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).

  16. A review of the non-bulimulid terrestrial Mollusca from the Region of Atacama, northern Chile

    Directory of Open Access Journals (Sweden)

    Juan Francisco Araya

    2014-04-01

    Full Text Available Terrestrial mollusca are sparsely studied in Chile and, for the first time, a formal record of the diversity of land snails in northern Chile is reported. Coastal and desertic areas in the Region of Atacama, in the border of the Atacama desert and the Pacific Ocean, were surveyed with the aim to describe the presence and distribution of this poorly known fauna. Of the fourteen species recorded, the geographic distribution records for nine species are extended, and some taxa are recorded for the first time since their original descriptions. All, except one, of the fourteen terrestrial molluscan species occurring in the area are endemic to Chile; they are all terrestrial species, most of them have a restricted geographic distribution, and none of them is currently protected by law. The results reveal that the region of Atacama has one of the most diverse terrestrial snail biodiversity in Chile, ranking only after the Juan Fernandez Archipelago. Distribution records of all the studied species and a taxonomic key are also provided.

  17. Ignimbrite textural properties as determinants of endolithic colonization patterns from hyper-arid Atacama Desert.

    Science.gov (United States)

    Cámara, Beatriz; Suzuki, Shino; Nealson, Kenneth H; Wierzchos, Jacek; Ascaso, Carmen; Artieda, Octavio; de Los Ríos, Asunción

    2014-09-01

    This study explores the photosynthetic microbial colonization of rhyolitic ignimbrites in Lomas de Tilocalar, a hyper-arid region of the Atacama Desert, Chile. Colonization appeared in the form of a green layer a few millimeters beneath the ignimbrite surface. Some ignimbrite rocks revealed two distinct micromorphological areas of identical mineralogical and chemical composition but different textural properties. According to texture, colonization patterns varied in terms of the extension and depth of colonization. The diversity of photosynthetic microorganisms was assessed by denaturing gradient gel electrophoresis (DGGE) of the 23S rRNA gene and by generating clone libraries of the 16S rRNA gene. We observed a low diversity of photosynthetic microorganisms colonizing the ignimbrite microhabitat. Most rRNA gene sequences recovered greatly resembled those of Chroococcidiopsis hypolith clones from arid deserts. These results point to highly restrictive conditions of the hyper-arid Atacama Desert conditioning the diversity of cyanobacteria, and suggest that microbial colonization and composition patterns might be determined by the microscale physico-chemical properties of the ignimbrite rocks [Int Microbiol 2014; 17(4):235-247]. PMID:26421739

  18. In situ metabolism in halite endolithic microbial communities of the hyperarid Atacama Desert.

    Science.gov (United States)

    Davila, Alfonso F; Hawes, Ian; Araya, Jonathan G; Gelsinger, Diego R; DiRuggiero, Jocelyne; Ascaso, Carmen; Osano, Anne; Wierzchos, Jacek

    2015-01-01

    The Atacama Desert of northern Chile is one of the driest regions on Earth, with areas that exclude plants and where soils have extremely low microbial biomass. However, in the driest parts of the desert there are microorganisms that colonize the interior of halite nodules in fossil continental evaporites, where they are sustained by condensation of atmospheric water triggered by the salt substrate. Using a combination of in situ observations of variable chlorophyll fluorescence and controlled laboratory experiments, we show that this endolithic community is capable of carbon fixation both through oxygenic photosynthesis and potentially ammonia oxidation. We also present evidence that photosynthetic activity is finely tuned to moisture availability and solar insolation and can be sustained for days, and perhaps longer, after a wetting event. This is the first demonstration of in situ active metabolism in the hyperarid core of the Atacama Desert, and it provides the basis for proposing a self-contained, endolithic community that relies exclusively on non-rainfall sources of water. Our results contribute to an increasing body of evidence that even in hyperarid environments active metabolism, adaptation, and growth can occur in highly specialized microhabitats. PMID:26500612

  19. In situ metabolism in halite endolithic microbial communities of the hyperarid Atacama Desert

    Directory of Open Access Journals (Sweden)

    Alfonso F Davila

    2015-10-01

    Full Text Available The Atacama Desert of northern Chile is one of the driest regions on Earth, with areas that exclude plants and where soils have extremely low microbial biomass. However, in the driest parts of the desert there are microorganisms that colonize the interior of halite nodules in fossil continental evaporites, where they are sustained by condensation of atmospheric water triggered by the salt substrate. Using a combination of in situ observations of variable chlorophyll fluorescence and controlled laboratory experiments, we show that this endolithic community is capable of carbon fixation both through oxygenic photosynthesis and potentially ammonia oxidation. We also present evidence that photosynthetic activity is finely tuned to moisture availability and solar insolation and can be sustained for days, and perhaps longer, after a wetting event. This is the first demonstration of in situ active metabolism in the hyperarid core of the Atacama Desert, and it provides the basis for proposing a self-contained, endolithic community that relies exclusively on non-rainfall sources of water. Our results contribute to an increasing body of evidence that even in hyperarid environments active metabolism, adaptation and growth can occur in highly specialized microhabitats.

  20. Fog deposition to a Tillandsia carpet in the Atacama Desert

    Directory of Open Access Journals (Sweden)

    P. Osses

    2009-09-01

    Full Text Available In the Atacama Desert, one of the driest places on earth, fog deposition plays an important role for the water balance and for the survival of vulnerable ecosystems. The eddy covariance method, previously applied for the quantification of fog deposition to forests in various parts of the world, was used for the first time to measure deposition of fog water to a desert. In this exploratory study we estimate the amount of water available for the ecosystem by deposition and determine the relevant processes driving fog deposition. This is especially important for the species Tillandsia landbecki living in coastal Atacama at the limit of plant existence with fog and dew being the only sources of water. Between 31 July and 19 August 2008 approximately 2.5 L m−2 of water were made available through deposition. Whole-year deposition was estimated as 25 L m−2. Turbulent upward fluxes occurred several times during the evenings and are explained by the formation of radiation fog. In connection with that, underestimates of the deposition are assumed. More detailed studies covering various seasons and all parameters and fluxes contributing to the local energy balance are suggested. This will help to further develop understanding about the processes of (i deposition of water to the desert, and (ii intensification of advection fog through additional formation of radiation fog.

  1. Robot Science Autonomy in the Atacama Desert and Beyond

    Science.gov (United States)

    Thompson, David R.; Wettergreen, David S.

    2013-01-01

    Science-guided autonomy augments rovers with reasoning to make observations and take actions related to the objectives of scientific exploration. When rovers can directly interpret instrument measurements then scientific goals can inform and adapt ongoing navigation decisions. These autonomous explorers will make better scientific observations and collect massive, accurate datasets. In current astrobiology studies in the Atacama Desert we are applying algorithms for science autonomy to choose effective observations and measurements. Rovers are able to decide when and where to take follow-up actions that deepen scientific understanding. These techniques apply to planetary rovers, which we can illustrate with algorithms now used by Mars rovers and by discussing future missions.

  2. Microbial colonisation of chasmoendolithic habitats in the hyper-arid zone of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    J. DiRuggiero

    2013-04-01

    Full Text Available Efforts in searching for microbial life in the driest part of Atacama Desert, Chile, revealed a small number of lithic habitats that can be considered as environmental refuges for life. In this study, we describe for the first time chasmoendolithic colonisation of fissures and cracks of rhyolite-gypsum and calcite rocks collected in the hyper-arid zone of the desert. The use of high-throughput sequencing revealed that the Atacama rock communities comprised a few dominant phylotypes and a number of less abundant taxa representing the majority of the total community diversity. The chasmoendolithic communities were dominated by Chroococcidiopsis species cyanobacteria and supported a number of heterotrophic bacterial lineages. Micro-climate data and geomorphic analysis of the mineral substrates suggested higher water availability in the calcite rocks in the form of enhanced water retention in the complex network of cracks and fissures of these rocks as well as increased occurrence of liquid water in the form of dewfall. These characteristics were associated with a diverse community of phototrophic and heterotrophic bacteria in the calcite chasmoendolithic ecosystem. This study is another example of the diversity of adaptive strategies at the limit for life and illustrates that rock colonisation is controlled by a complex set of factors.

  3. Microbial colonization of chasmoendolithic habitats in the hyper-arid zone of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    J. DiRuggiero

    2012-11-01

    Full Text Available Efforts in searching for microbial life in the driest part of Atacama Desert, Chile, revealed a small number of lithic habitats that can be considered as environmental refuges for life. In this study, we describe for the first time chasmoendolithic colonization of fissures and cracks of rhyolite-gypsum and calcite rocks collected in the hyper-arid zone of the desert. The use of high-throughput sequencing revealed that the Atacama rock communities comprised a few dominant phylotypes and a number of less abundant taxa representing the majority of the total community diversity. The chasmoendolithic communities were dominated by Chroococcidiopsis species cyanobacteria and supported a number of novel heterotrophic bacteria. Micro-climate data and geomorphic analysis of the mineral substrates suggested higher water availability in the calcite rocks in the form of enhanced water retention in the complex network of cracks and fissures of these rocks as well as increased occurrence of liquid water in the form of dewfall. These characteristics were associated with a diverse community of phototrophic and heterotrophic bacteria in the calcite chasmoendolithic ecosystem. This study is another example of the diversity of adaptive strategies at the limit for life and illustrates that rock colonization is controlled by a complex set of factors.

  4. Archipelago of endolithic microbial life in the hyper arid core of the Atacama Desert

    OpenAIRE

    Wierzchos, Jacek; Davila, Alfonso F.; Diruggiero, J.; Ríos, Asunción de los; Valea, Sergio; Cámara Gallego, Beatriz; Artieda, Octavio; Speranza, Mariela; Robinson, Courtney K; Souterre, T.; Souza Egipsy, Virginia; Ascaso, Carmen

    2012-01-01

    The hyper-arid core of the Atacama Desert is considered the driest and most life-limited place on Earth. As such, this desert is an ideal environment to study the survival and biological adaptation strategies of microorganisms to this extremely dry environment. The extreme aridity of the Atacama Desert allows us to address questions such as the potential for life in extraterrestrial environments such as the surface of Mars. Our results over the last six years of searching for micr...

  5. Genetic Characterization of Old Grapevines collected in Oases of the Atacama Desert Caracterización Genética de Vides Antiguas colectadas en Oasis del Desierto de Atacama

    OpenAIRE

    Ingrid Poblete; Manuel Pinto; María Teresa de Andrés; Patricio Hinrichsen

    2011-01-01

    Old grapevine (Vitis vinifera L.) accessions are a source of genes that could be rescued for use per se or in modern breeding programs. The first step in this rescuing is collecting and characterizing the germplasm from a particular region. This study presents the genetic characterization of 21 grapevine accessions collected from the Atacama Desert in the far North of Chile. Characterization was based on 12 microsatellites (Simple Sequence Repeats, or SSRs) supplemented with Amplified Fragmen...

  6. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    Science.gov (United States)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  7. Biodegradation of Tributyltin (TBT) by Extremophile Bacteria from Atacama Desert and Speciation of Tin By-products.

    Science.gov (United States)

    Yáñez, Jorge; Riffo, Paula; Santander, Paola; Mansilla, Héctor D; Mondaca, María Angélica; Campos, Víctor; Amarasiriwardena, Dulasiri

    2015-07-01

    Biodegradation of tributyltin (TBT) by four tin resistant Gram negative bacteria isolated from extremely contaminated river sediments in the Atacama Desert in Chile was studied. Moraxella osloensis showed the greatest resistance and degradation capability of TBT, producing less toxic by-products, such as dibutyltin (DBT) and inorganic tin. In 7 days, approximately 80 % of TBT degradation was achieved, generating close to 20 % of DBT as degradation product. The degradation rate constant (k) was 0.022 [day(-1)] and TBT half-life (t1/2) in culture was 4.3 days. Debutylation is stated a probable mechanism of TBT degradation. PMID:25975619

  8. Atmospheric water uptake by an atacama desert shrub.

    Science.gov (United States)

    Mooney, H A; Gulmon, S L; Ehleringer, J; Rundel, P W

    1980-08-01

    Nolana mollis, a succulent-leaved shrub of the extreme coastal desert of Chile, has the capacity to condense water on its leaves out of unsaturated atmospheres, Metabolic energy would have to be expended to move this water either from the leaf surface directly to the mesophyll or, when dripped to the soil, from there into the roots. Because of the unusual aridity of its habitat and of the utilization of water-use-efficient metabolism by Nolana, at least during certain periods, such an energy expenditure could be effective. PMID:17821192

  9. Novel water source for endolithic life in the hyperarid core of the Atacama Desert

    Science.gov (United States)

    Wierzchos, J.; Davila, A. F.; Sánchez-Almazo, I. M.; Hajnos, M.; Swieboda, R.; Ascaso, C.

    2012-06-01

    The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most life-limited place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here, we show that halite endoliths obtain liquid water through spontaneous capillary condensation at relative humidity (RH) much lower than the deliquescence RH of NaCl. We describe how this condensation could occur inside nano-pores smaller than 100 nm, in a newly characterized halite phase that is intimately associated with the endolithic aggregates. This nano-porous phase helps retain liquid water for long periods of time by preventing its evaporation even in conditions of utmost dryness. Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet.

  10. Novel water source for endolithic life in the hyperarid core of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    J. Wierzchos

    2012-03-01

    Full Text Available The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most abiotic place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here we show that halite endoliths obtain liquid water through spontaneous capillary condensation at relative humidity (RH much lower than the deliquescence RH of NaCl. We describe how this condensation occurs inside nano-pores smaller than 100 nm, in a newly identified halite phase that is intimately associated with the endolithic aggregates. This nano-porous phase helps retain liquid water for long periods of time by preventing its evaporation even in conditions of utmost dryness. Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet.

  11. Novel water source for endolithic life in the hyperarid core of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    J. Wierzchos

    2012-06-01

    Full Text Available The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most life-limited place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here, we show that halite endoliths obtain liquid water through spontaneous capillary condensation at relative humidity (RH much lower than the deliquescence RH of NaCl. We describe how this condensation could occur inside nano-pores smaller than 100 nm, in a newly characterized halite phase that is intimately associated with the endolithic aggregates. This nano-porous phase helps retain liquid water for long periods of time by preventing its evaporation even in conditions of utmost dryness. Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet.

  12. Pollen analyses from a 50 000-yr rodent midden series in the southern Atacama Desert (25° 300' S)

    Science.gov (United States)

    Maldonado, Antonio; Betancourt, Julio L.; Latorre, Claudio; Villagran, Carolina

    2005-01-01

    Precipitation in northern Chile is controlled by two great wind belts—the southern westerlies over the southern Atacama and points south (>24° S) and the tropical easterlies over the northern and central Atacama Desert (16–24° S). At the intersection of these summer and winter rainfall regimes, respectively, is a Mars-like landscape consisting of expansive surfaces devoid of vegetation (i.e. absolute desert) except in canyons that originate high enough to experience runoff once every few years. Pollen assemblages from 39 fossil rodent middens in one of these canyons, Quebrada del Chaco (25° 30' S), were used to infer the history of vegetation and precipitation at three elevations (2670–800 m; 3100–3200 m; 3450–3500 m) over the past 50 000 years. When compared to modern conditions and fossil records to the north and south, the pollen evidence indicates more winter precipitation at >52, 40–33, 24–17 k cal.yrBP, more precipitation in both seasons at 17–14 k cal. yr BP, and more summer precipitation from 14–11 k cal. yr BP. Younger middens are scarce at Quebrada del Chaco, and the few Holocene samples indicate hyperarid conditions comparable to today. The only exception is a pollen assemblage that indicates a brief but significant interlude of increased winter precipitation in the last millennium.

  13. Coatings on Atacama Desert Basalt: A Possible Analog for Coatings on Gusev Plains Basalt

    Science.gov (United States)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    Surface coatings on Gusev Plains basalt have been observed and may contain hematite and nanophase Fe-oxides along with enrichments in P, S, Cl, and K relative to the underlying rock. The Gusev coatings may be derived from the dissolution of adhering soil and/or parent rock along with the addition of S and Cl from outside sources. Transient water for dissolution could be sourced from melting snow during periods of high obliquity, acid fog, and/or ground water (Haskin et al., 2005). Coatings on basalt in the hyper-arid (less than 2mm y(sup -1)) Atacama Desert may assist in understanding the chemistry, mineralogy and formation mechanisms of the Gusev basalt coatings. The Atacama Desert climate is proposed to be analogous to a paleo-Mars climate that was characterized by limited aqueous activity when the Gusev coatings could have formed. The objectives of this work are to (i) determine the chemical nature and extent of surface coatings on Atacama Desert basalt, and (ii) assess coating formation mechanisms in the Atacama Desert. Preliminary backscattered electron imaging of Atacama basalt thin-sections indicated that the coatings are as thick as 20 m. The boundary between the coating and the basalt labradorite, ilmenite, and augite grains was abrupt indicating that the basalt minerals underwent no chemical dissolution. The Atacama coatings have been added to the basalt instead of being derived from basalt chemical weathering. Semi-quantitative energy dispersive spectroscopy shows the coatings to be chemically homogeneous. The coating is depleted in Ca (0.9 wt% CaO) and enriched in K (1.3 wt.% K2O) and Si (69.1 wt.% SiO2) relative to the augite and labradorite grains. A dust source enriched in Si (e.g., poorly crystalline silica) and K and depleted in Ca appears to have been added to the basalt surface. Unlike the Gusev coatings, no P, S, and Cl enrichment was observed. However, Fe (3.2 wt.% FeO) was present in the Atacama coatings suggesting the present of Fe

  14. APECS - The Atacama Pathfinder Experiment Control System

    OpenAIRE

    Muders, D.; Hafok, H.; Wyrowski, F.; Polehampton, E.; Belloche, A.; Koenig, C.; Schaaf, R.; Schuller, F.; Hatchell, J.; Tak, F. v. d.

    2006-01-01

    APECS is the distributed control system of the new Atacama Pathfinder EXperiment (APEX) telescope located on the Llano de Chajnantor at an altitude of 5107 m in the Atacama desert in northern Chile. APECS is based on Atacama Large Millimeter Array (ALMA) software and employs a modern, object-oriented design using the Common Object Request Broker Architecture (CORBA) as the middleware. New generic device interfaces simplify adding instruments to the control system. The Python based observer co...

  15. How much Carbon is Stored in Deserts? AN Approach for the Chilean Atacama Desert Using LANDSAT-8 Products

    Science.gov (United States)

    Hernández, H. J.; Acuña, T.; Reyes, P.; Torres, M.; Figueroa, E.

    2016-06-01

    The Atacama Desert in northern Chile is known as the driest place on Earth, with an average rainfall of about 15 mm per year. Despite these conditions, it contains a rich variety of flora with hundreds of species characterised by their extraordinary ability to adapt to this extreme environment. These biotic components have a direct link to important ecosystem services, especially those related to carbon storage and sequestration. No quantitative assessment is currently available for these services and the role of the desert in this matter remains unclear. We propose an approach to estimate above-ground biomass (AGB) using Landsat-8 data, which we tested in the Taparacá region, located in the northern section of the desert. To calibrate and validate the models, we used field data from 86 plots and several spectral indexes (NDVI, EVI and SAVI) obtained from the provisional Landsat-8 Surface-reflectance products. We applied randomised branch sampling and allometry principles (non-destructive methods) to collect biomass samples for all plant biological types: wetlands, steppes, shrubs and trees. All samples were dried in an oven until they reached constant weight and the final values were used to extrapolate dry matter content (AGB) to each plot in terms of kg m-2. We used all available scenes from September 2014 to August 2015 to calculate the maximum, minimum and average value for each index in each pixel within this period. For modeling, we used the method based on classification and regression trees called random forest (RF), available in the statistical software R-Project. The explained variance obtained by the RF algorithm was around 80-85%, and it improved when a wetland vector layer was used as the predictive factor in the model to reach the range 85-90%. The mean error was 1.45 kg m-2 of dry matter. The best model was obtained using the maximum and mean values of SAVI and EVI indexes. We were able to estimate total biomass storage of around 8 million tons

  16. Comparative analysis of the microbial communities inhabiting halite evaporites of the Atacama Desert

    OpenAIRE

    Ríos, Asunción de los; Valea, Sergio; Ascaso, Carmen; Davila, Alfonso F.; Kastovsky, Jan; McKay, Christopher P.; Wierzchos, Jacek

    2010-01-01

    Molecular biology and microscopy techniques were used to characterize the microbial communities inside halide evaporites from different parts of th Atacama Desert. Denaturing gradient fel eletrophoresis (DGGE) analysis revealed that the evaporite rocks harbor communities predominantly made up of cyanobacteria, along with heterotrophic bacteria an archae...

  17. Timing of wet episodes in Atacama Desert over the last 15 ka. The Groundwater Discharge Deposits (GWD) from Domeyko Range at 25°S.

    Science.gov (United States)

    Sáez, Alberto; Godfrey, Linda V.; Herrera, Christian; Chong, Guillermo; Pueyo, Juan J.

    2016-08-01

    A chronologically robust reconstruction of timing and dynamics of millennial time scale wet episodes encompassing the entire Atacama Desert during the last 15 ka has been constructed. To accomplish this, a new composite paleoclimatic record from Groundwater Discharge Deposits (GWD) in the Sierra de Varas (Domeyko Range, southern Atacama in Chile at 25°S) has been compiled and compared with other published paleohydrologic records from the Atacama region. In Sierra de Varas (SV), three millennial timescale wet climate phases have been characterized: around 14.5 ka cal BP, 12.2-9.8 ka cal BP, and 4.7 ka cal BP to the present day. These wet phases are interpreted from intervals of GWD facies formed during periods when the springs were active. GWD facies include: (1) black organic peat, rooted mudstones and sandstones formed in local wetland environments, and (2) gypsum-carbonate rich layers formed by interstitial growth. GWD intervals alternate with gravelly alluvial material deposited during arid phases. A trend towards less humid conditions during the Late Holocene wet episode characterizes GWD sedimentary series in Sierra the Varas, suggesting the onset of a dry episode over the last few centuries. Around 0.7 ka BP a very short wet episode is recorded in the central part of the desert suggesting this was the time of maximum humidity for the entire late Holocene wet period. A brief arid phase occurred between 1.5 and 2.0 ka BP indicated by the absence of GWD in the Domeyko Range. The paleoclimatic reconstruction encompassing the entire Atacama region shows that both the intensity and occurrence of wetter conditions were governed mainly by the distance to the source of moisture, and secondarily by the elevation of the sites. In the northern Atacama (16-20°S), four wet phases fed by N-NE summer monsoon precipitations have been proposed: Tauca phase (18-14 ka cal BP) and Coipasa phase (13-10 ka cal BP) during the Late Glacial, followed by Early Holocene and Late

  18. Alto Patache fog oasis in the Atacama Desert: Geographical basis for a sustainable development program

    Science.gov (United States)

    Calderón, M.; Cereceda, P.; Larrain, H.; Osses, P.; Pérez, L.; Ibáñez, M.

    2010-07-01

    Alto Patache coastal fog oasis is a protected area located south of Iquique, Northern Chile, being presently in charge of the Atacama Desert Center (ADC) research group of the Pontificia Universidad Católica de Chile, since 1997. On 2007, the Chilean Government bestowed a piece of land stretch covering 1,114 hectares to ADC scientific group for scientific research, ecosystem protection and environmental education. This oasis has been recently studied from different points of view: climate, biogeography, fog collection, geomorphology, soil survey and land use planning, plant distribution, conservation and archaeology. During 2009, a study of the geographical basis to elaborate a general management plan was undertaken to collect information to fulfill our planned out objectives. Through this study, georreferenciated strategic information was compiled to evaluate future actions conducting to a sustainable development within the protected area. This information was translated into thematic maps showing the spatial distribution of variables like: climate, geology, geomorphology, soils, vegetation, fauna, archaeological sites and management zones. The methodology used is the analysis of satellite imagery, using GPS by creating a cartographic Data Base incorporated in GIS. Results show that the area starts at the littoral plain, ranging from 500 m to 2.000 m, being continued in parts by a piedmont intercepted by a very abrupt mega-cliff, or hectares of climbing sand dunes leading to a short high plateau limited by a soft hilly area to the East. Two soil types are characteristic: Entisols (Torriorthent) covering the coastal beach sediments, and Aridisols along the cliff and adjacent hills. Vegetation consists not only of a very rich lichen cover, but also of endangered vascular species associations constituting a very fragile sub-tropical coastal desert community, such as Eulychnia, Cumulopuntia, Eriosyce cacti, and Lycium - Nolana- Ephedra communities. Fog oasis

  19. Numerical taxonomy of moderately halophilic gram-positive cocci isolated from the Salar de Atacama (Chile).

    Science.gov (United States)

    Valderrama, M J; Prado, B; del Moral, A; Ríos, R; Ramos-Cormenzana, A; Campos, V

    1991-06-01

    A taxonomic study has been carried out on 22 strains of moderately halophilic motile cocci isolated from the Salar de Atacama (Chile). The 112 phenotypic tests were analyzed by numerical taxonomy using SSM coefficient and the unweighted pair group method of association (UPGMA). At the 67% similarity level, two phenons were obtained: phenon A included 11 strains and phenon B, 11 strains too, whereas the six reference strains did not cluster within these two phenons. These results suggest that moderately halophilic cocci with different phenotypic characteristics from previously described species can be isolated from the hypersaline habitat Salar de Atacama. PMID:1867776

  20. The Bulimulidae (Mollusca: Pulmonata) from the Región de Atacama, northern Chile.

    Science.gov (United States)

    Araya, Juan Francisco

    2015-01-01

    The bulimulid genus Bostryx Troschel, 1847 is the most species-rich genus of land snails found in Chile, with the majority of its species found only in the northern part of the country, usually in arid coastal zones. This genus has been sparsely studied in Chile and there is little information on their distribution, diversity or ecology. Here, for the first time, a formal analysis of the diversity of bulimulids in the Región de Atacama, northern Chile, is reported. Of the seventeen species recorded for the area, most of them were efectively found in the field collections and one record was based on literature. Five taxa are described as new: Bostryx ancavilorum sp. nov., Bostryx breurei sp. nov., Bostryx calderaensis sp. nov., Bostryx ireneae sp. nov. and Bostryx valdovinosi sp. nov., and the known geographic distribution of seven species is extended. Results reveal that the Región de Atacama is the richest region in terrestrial snails in Chile, after the Juan Fernández Archipelago. All of the terrestrial molluscan species occurring in the area are endemic to Chile, most of them with restricted geographic distributions along the coastal zones, and none of them are currently protected by law. Further sampling in northern Chile will probably reveal more snail species to be discovered and described. PMID:26587346

  1. Deep seismic structure of the Atacama basin, northern Chile

    Science.gov (United States)

    Schurr, B.; Rietbrock, A.

    2004-06-01

    The Atacama basin is a prominent morphological anomaly in the Central Andean forearc. 3D seismic structure beneath the depression and its surroundings has been determined from local earthquake tomography. Depth maps of P-wave velocity and attenuation (1/Qp) through the lithosphere reveal a rheologically strong (high Qp and vp) lithospheric block beneath the basin, surrounded by weak regions (low Qp and vp) beneath Pre- and Western Cordilleras. The anomalous lithospheric structure appears to bar hot asthenospheric mantle from penetrating trenchward, and hence causes the volcanic front to be deflected by the Salar de Atacama basin. The cold block may also influence the thermal structure of the subducted slab causing reduced Benioff seismicity and less hydration of mantle rocks evident from reduced vp/vs ratios. Seismic data are hard to reconcile with extension and lithospheric thinning as a mechanism for subsidence of the basin. Instead, high strength of the Atacama lithospheric block may contribute to basin formation by focussing deformation and uplift along the block's weak edges.

  2. Endolithic Cyanobacteria in Halite Rocks from the Hyperarid Core of the Atacama Desert

    Science.gov (United States)

    Wierzchos, Jacek; Ascaso, Carmen; McKay, Christopher P.

    2006-06-01

    In the driest parts of the Atacama Desert there are no visible life forms on soil or rock surfaces. The soil in this region contains only minute traces of bacteria distributed in patches, and conditions are too dry for cyanobacteria that live under translucent stones. Here we show that halite evaporite rocks from the driest part of the Atacama Desert are colonized by cyanobacteria. This colonization takes place just a few millimeters beneath the rock surface, occupying spaces among salt crystals. Our work reveals that these communities are composed of extremely resistant Chroococcidiopsis morphospecies of cyanobacteria and associated heterotrophic bacteria. This newly discovered endolithic environment is an extremely dry and, at the same time, saline microbial habitat. Photosynthetic microorganisms within dry evaporite rocks could be an important and previously unrecognized target for the search for life within our Solar System.

  3. Extreme environments as potential drivers of convergent evolution by exaptation: the Atacama Desert Coastal Range case

    OpenAIRE

    Azua-Bustos, Armando; González-Silva, Carlos; Arenas-Fajardo, Cristián; Vicuña, Rafael

    2012-01-01

    We have recently discovered a variety of unrelated phototrophic microorganisms (two microalgae and one cyanobacteria) in specialized terrestrial habitats at The Coastal Range of the Atacama Desert. Interestingly, morphological and molecular evidence suggest that these three species are all recent colonists that came from aquatic habitats. The first case is Cyanidiales inhabiting coastal caves. Cyanidiales are microalgae that are commonly found in warm acid springs, but have also been recently...

  4. Desarrollo territorial y turismo en San Pedro de Atacama [Chile

    OpenAIRE

    Gutiérrez Valdivia, Blanca Alexandra

    2010-01-01

    En los últimos diez años, San pedro de Atacama ha experimentado un fuerte crecimiento del sector turístico, como también un explosivo auge de emigración hacia la comuna debido a una fuerte oferta y demanda del sector turístico. Esta situación se enmarca dentro de una falta de planificación sostenible que responda a las problemáticas sociales, culturales y ambientales que se han desarrollado en la comuna.

  5. Distribution and Diversity of Organic and Biological Signatures in Soils From the Atacama Desert

    Science.gov (United States)

    Sharma, Aditi

    2005-01-01

    The Atacama Desert is amongst the driest places on Earth. It is considered to be a suitable analog for the Martian surface in which to conduct studies of life and life detection. Soil samples were collected in June 2005 from the Atacama Desert and analyzed in the lab for amino acid content. HPLC was the primary tool used to analyze samples. The amino acids of interest are aspartic acid, serine, glutamic acid, glycine, and alanine. D and L isomers of each amino acid (except for glycine) were separated through HPLC. The purpose of this study is to find correlations between location of the sample collection sites and amino acid content as well as D/L isomer ratios in order to formulate theories of how different types of environments may affect the abundance and distribution of life forms. Initial analysis of data shows a general lack of or slight correlation between location and amino acid content. Some data appears to contradict the hypothesis that harsher environments would have lower amino acid content than less harsh environments. Further analysis of data is needed to come up with a more conclusive report of the distribution of amino acids in the Atacama Desert.

  6. Mars Redox Chemistry: Atacama Desert Soils as a Terrestrial Analog

    Science.gov (United States)

    Quinn, R. C.; Grunthaner, F. J.; Taylor, C. L.; Zent, A. P.

    2003-01-01

    The motivation for this work is to perform quantitative site characterizations of soil chemical processes to allow further development and field validation of the Mars Oxidant Instrument (MOI). The MOI is an in situ survey instrument designed to establish the presence of reactive chemical species in the martian soil, dust, or atmosphere, and to provide detailed reaction model system measurements to enable comprehensive Earthbased study. Functioning as a survey instrument, MOI tests the broad range of hypotheses explaining the reactivity of the martian surface material that have been put forth since the Viking experiments. This work is currently being carried out under the NASA ASTEP funded AstroBioLab (Jeffery Bada, PI). A second objective is to use Atacama field and Viking data to perform comparative studies, with the goal of furthering the understanding of the formation mechanisms and properties of martian oxidants.

  7. Evolutionary lag times and recent origin of the biota of an ancient desert (Atacama-Sechura).

    Science.gov (United States)

    Guerrero, Pablo C; Rosas, Marcelo; Arroyo, Mary T K; Wiens, John J

    2013-07-01

    The assembly of regional biotas and organismal responses to anthropogenic climate change both depend on the capacity of organisms to adapt to novel ecological conditions. Here we demonstrate the concept of evolutionary lag time, the time between when a climatic regime or habitat develops in a region and when it is colonized by a given clade. We analyzed the time of colonization of four clades (three plant genera and one lizard genus) into the Atacama-Sechura Desert of South America, one of Earth's driest and oldest deserts. We reconstructed time-calibrated phylogenies for each clade and analyzed the timing of shifts in climatic distributions and biogeography and compared these estimates to independent geological estimates of the time of origin of these deserts. Chaetanthera and Malesherbia (plants) and Liolaemus (animal) invaded arid regions of the Atacama-Sechura Desert in the last 10 million years, some 20 million years after the initial onset of aridity in the region. There are also major lag times between when these clades colonized the region and when they invaded arid habitats within the region (typically 4-14 million years). Similarly, hyperarid climates developed ∼8 million years ago, but the most diverse plant clade in these habitats (Nolana) only colonized them ∼2 million years ago. Similar evolutionary lag times may occur in other organisms and habitats, but these results are important in suggesting that many lineages may require very long time scales to adapt to modern desertification and climatic change. PMID:23798420

  8. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert.

    Science.gov (United States)

    Wierzchos, Jacek; DiRuggiero, Jocelyne; Vítek, Petr; Artieda, Octavio; Souza-Egipsy, Virginia; Škaloud, Pavel; Tisza, Michel; Davila, Alfonso F; Vílchez, Carlos; Garbayo, Inés; Ascaso, Carmen

    2015-01-01

    The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits-conceptually called "rock's habitable architecture." Additionally, self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another level of adaptation

  9. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    Jacek eWierzchos

    2015-09-01

    Full Text Available The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits – conceptually called rock’s habitable architecture. Additionally self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another

  10. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

    Science.gov (United States)

    Wierzchos, Jacek; DiRuggiero, Jocelyne; Vítek, Petr; Artieda, Octavio; Souza-Egipsy, Virginia; Škaloud, Pavel; Tisza, Michel; Davila, Alfonso F.; Vílchez, Carlos; Garbayo, Inés; Ascaso, Carmen

    2015-01-01

    The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits—conceptually called “rock's habitable architecture.” Additionally, self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another level of

  11. Extreme environments as potential drivers of convergent evolution by exaptation: the Atacama Desert Coastal Range case.

    Directory of Open Access Journals (Sweden)

    ArmandoAzua-Bustos

    2012-12-01

    Full Text Available We have recently discovered a variety of unrelated phototrophic microorganisms (two microalgae and one cyanobacteria in specialized terrestrial habitats at The Coastal Range of the Atacama Desert. Interestingly, morphological and molecular evidence suggest that these three species are all recent colonists that came from aquatic habitats. The first case is Cyanidiales inhabiting coastal caves. Cyanidiales are microalgae that are commonly found in warm acid springs, but have also been recently discovered as cave flora in Italy. The case is Dunaliella biofilms colonizing spider webs in coastal caves; Dunaliella are microalgae typically found in hypersaline habitats. The third case is Chroococcidiopsis, a genus of Cyanobacteria commonly found in deserts around the world that has also been described in warm springs. Thus, we show that the traits found in the closest ancestors of the aforementioned species (which inhabited other unrelated extreme environments seem to be now useful for the described species in their current subaerial habitats, and may likely correspond to cases of exaptations. Altogether, the Coastal Range of the Atacama Desert may be considered as a place where key steps on the colonization of land by phototrophic organisms seem to be being repeated by convergent evolution of extant microalgae and Cyanobacteria.

  12. Miocene-Quaternary structural evolution of the Uyuni-Atacama region, Andes of Chile and Bolivia

    OpenAIRE

    Tibaldi, A.; Università degli Studi di Milano-Bicocca; Corazzato, C.; Università degli Studi di Milano-Bicocca; Rovida, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia

    2008-01-01

    We describe the Miocene-Quaternary geological-structural evolution of the region between the Salar de Uyuni and de Atacama, Andes of Chile and Bolivia. We recognised four main tectonic events based on fold geometry, fault kinematics and stratigraphic data. The oldest event, of Miocene age, is characterized by folding and reverse faulting of the sedimentary successions with an E-W direction of shortening in the northern part of the studied area and a WNW-ESE shortening in the southern part. Th...

  13. ALMA (Atacama Large Millimetre/ Submillimetre Array)

    OpenAIRE

    Barcons, Xavier

    2010-01-01

    ALMA is a large sub/millimetre observatory in construction phase (Atacama desert, Chile). When finished it will be the world’s largest interferometer for millimetre and submillimetre wavelengths. Three sites: 1)Array Operations Site (AOS), llano de Chajnantor (5100 m). 2)Operations Support Facility (OSF), near San Pedro de Atacama (2900m). 3)Santiago Central Office (SCO). First large ground-based “global” scientific infrastructure.

  14. Com sobreviuen els microorganismes fotosintètics al desert d'Atacama?

    OpenAIRE

    Roldán, Mònica

    2014-01-01

    Amb un índex d'aridesa del 0,0005, el desert d'Atacama (Xile) és el lloc més sec de la Terra. Investigadors del Servei de Microscòpia de la UAB i del Museu Nacional de Ciències Naturals de Madrid han publicat un estudi en el qual es demostren les diferents estratègies que els microorganismes fotosintètics han desenvolupat en aquest ambient d'extrema sequedat per sobreviure a l'interior de les halites, roques compostes de sal comuna (NaCl), on han de fer front a condicions de salinitat extrema...

  15. Oral health in prehistoric San Pedro de Atacama oases, Northern Chile.

    Science.gov (United States)

    Oliveira, R E; Neves, W A

    2015-12-01

    After almost 2000 years of local development, including limited trading with neighboring ethnic groups, the societies that occupied the oases of San Pedro de Atacama, Northern Chile, became part of the trade web of the Tiwanaku empire, between 500 and 1000 CE. Archaeological evidence tends to support the idea that the period under the influence of the altiplano (high plane) empire was very affluent. Here we investigate the possibility that this affluence had a positive impact on the health status of the Atacameneans, using the oral health as an indirect indicator of quality of life. Dental decay, dental abscess, dental wear, linear enamel hypoplasia, periodontal disease and dental calculus were analyzed on 371 skeletons from 12 sites from San Pedro de Atacama oases. We believe that if, indeed, there were better biological conditions during the altiplano influence, this could have been caused by the access to a more diversified food intake promoted by the intensification of the trading network established by Tiwanaku in the central-south Andes, of which San Pedro de Atacama became an important node. PMID:26253130

  16. Origen de las arenas dunares de la región de Copiapó, Desierto de Atacama, Chile

    Directory of Open Access Journals (Sweden)

    Roland Paskoff

    2003-12-01

    Full Text Available Las extensas dunas de la región de Copiapó presentan formas vivas, pero son dunas remanentes ya que su fuente de abastecimiento en arena fresca está agotada. Según algunos autores, sus arenas habrían provenido por deflación de los depósitos de playa de las amplias terrazas marinas solevantadas que caracterizan la franja costera entre el río Copiapó y Caldera. Antecedentes sedimentológicos no confirman esta interpretación y sugieren un origen fluvial para las arenas. Éstas podrían provenir de formaciones detríticas acumuladas en el Neógeno cerca de sus desembocaduras por el río Copiapó y las quebradas situadas inmediatamente al norteOrigin of sand dunes in the Copiapó region, Atacama Desert, Chile. Extensive areas of active dunes are found in the Copiapó region. However, their sand supply is presently depleted. It has been proposed that deflated uplifted marine terraces of the coastal belt between the Copiapó River and Caldera were the source of the dune sand. Such a hypothesis is not supported by sedimentologic data, which suggest a fluvial origin for the aeolian sands. They could be related to Neogene alluvial accumulations built up at the mouth of the Copiapó River and the ephemeral streams located to the north of it

  17. Remote Sensing-Based Detection and Spatial Pattern Analysis for Geo-Ecological Niche Modeling of Tillandsia SPP. In the Atacama, Chile

    Science.gov (United States)

    Wolf, N.; Siegmund, A.; del Río, C.; Osses, P.; García, J. L.

    2016-06-01

    In the coastal Atacama Desert in Northern Chile plant growth is constrained to so-called `fog oases' dominated by monospecific stands of the genus Tillandsia. Adapted to the hyperarid environmental conditions, these plants specialize on the foliar uptake of fog as main water and nutrient source. It is this characteristic that leads to distinctive macro- and micro-scale distribution patterns, reflecting complex geo-ecological gradients, mainly affected by the spatiotemporal occurrence of coastal fog respectively the South Pacific Stratocumulus clouds reaching inlands. The current work employs remote sensing, machine learning and spatial pattern/GIS analysis techniques to acquire detailed information on the presence and state of Tillandsia spp. in the Tarapacá region as a base to better understand the bioclimatic and topographic constraints determining the distribution patterns of Tillandsia spp. Spatial and spectral predictors extracted from WorldView-3 satellite data are used to map present Tillandsia vegetation in the Tarapaca region. Regression models on Vegetation Cover Fraction (VCF) are generated combining satellite-based as well as topographic variables and using aggregated high spatial resolution information on vegetation cover derived from UAV flight campaigns as a reference. The results are a first step towards mapping and modelling the topographic as well as bioclimatic factors explaining the spatial distribution patterns of Tillandsia fog oases in the Atacama, Chile.

  18. REMOTE SENSING-BASED DETECTION AND SPATIAL PATTERN ANALYSIS FOR GEO-ECOLOGICAL NICHE MODELING OF TILLANDSIA SPP. IN THE ATACAMA, CHILE

    Directory of Open Access Journals (Sweden)

    N. Wolf

    2016-06-01

    Full Text Available In the coastal Atacama Desert in Northern Chile plant growth is constrained to so-called ‘fog oases’ dominated by monospecific stands of the genus Tillandsia. Adapted to the hyperarid environmental conditions, these plants specialize on the foliar uptake of fog as main water and nutrient source. It is this characteristic that leads to distinctive macro- and micro-scale distribution patterns, reflecting complex geo-ecological gradients, mainly affected by the spatiotemporal occurrence of coastal fog respectively the South Pacific Stratocumulus clouds reaching inlands. The current work employs remote sensing, machine learning and spatial pattern/GIS analysis techniques to acquire detailed information on the presence and state of Tillandsia spp. in the Tarapacá region as a base to better understand the bioclimatic and topographic constraints determining the distribution patterns of Tillandsia spp. Spatial and spectral predictors extracted from WorldView-3 satellite data are used to map present Tillandsia vegetation in the Tarapaca region. Regression models on Vegetation Cover Fraction (VCF are generated combining satellite-based as well as topographic variables and using aggregated high spatial resolution information on vegetation cover derived from UAV flight campaigns as a reference. The results are a first step towards mapping and modelling the topographic as well as bioclimatic factors explaining the spatial distribution patterns of Tillandsia fog oases in the Atacama, Chile.

  19. Infecção por Enterobius vermicularis em populações agro-pastoris pré-colombianas de San Pedro de Atacama, Chile Enterobius vermicularis infection in pre-Columbian population from San Pedro de Atacama, Chile

    OpenAIRE

    Luiz Fernando Ferreira; Adauto Araujo; Ulisses Confalonieri; Lautaro Nuñez

    1989-01-01

    Enterobius vermicularis eggs were found in human coprolites collected from the archaeological site of San Pedro de Atacama, North of Chile, in occupational layers dated from 1,000 BC. Agricultures and herding were begining at this period of time in this region of South America. The paleoparasitological data amplifies the knowledge about the distribution of human oxyuriasis in Pre-Columbian America.

  20. The shallow-water chitons (Mollusca, Polyplacophora of Caldera, Region of Atacama, northern Chile

    Directory of Open Access Journals (Sweden)

    Juan Francisco Araya

    2015-03-01

    Full Text Available The Molluscan species of the northern littoral of Chile have been sparsely studied. This work reviews for the first time the diversity of polyplacophoran molluscs around the port of Caldera, in the Region of Atacama (26°45’49”S; 70°45’17”W to 27°20’23”S; 70°56’46”W, northern Chile. Eleven species were found in this study: Acanthopleura echinata (Barnes, 1824; Callistochiton pulchellus (Gray, 1828; Calloplax vivipara (Plate, 1899, Chaetopleura peruviana (Lamarck, 1819; Chiton cumingsii Frembly, 1827; Chiton granosus Frembly, 1827; Chiton magnificus Deshayes, 1827; Enoplochiton niger (Barnes, 1824, Radsia barnesii (Gray, 1828, Tonicia atrata (G. B. Sowerby II, 1840 and Tonicia chilensis (Frembly, 1827. All of the species occurring in the area have distributions in the southeastern Pacific Ocean, from Ecuador to central Chile, and three of them are species endemic to the Chilean coasts (Calloplax vivipara, Radsia barnesii, and Tonicia atrata. This diversity of species is comparable to that of better surveyed faunas of central and southern Chile or Patagonia. Of the eleven species recorded, the geographic distribution records for Callistochiton pulchellus, Radsia barnesii and Tonicia atrata are extended, and Calloplax vivipara is found alive again after 40 years, filling a gap in its known distribution. Illustrations of living specimens in their habitat, distribution records and a taxonomic key for all the studied taxa are also provided.

  1. Bacterial Diversity in Microbial Mats and Sediments from the Atacama Desert.

    Science.gov (United States)

    Rasuk, Maria Cecilia; Fernández, Ana Beatriz; Kurth, Daniel; Contreras, Manuel; Novoa, Fernando; Poiré, Daniel; Farías, María Eugenia

    2016-01-01

    The Atacama Desert has extreme environmental conditions that allow the development of unique microbial communities. The present paper reports the bacterial diversity of microbial mats and sediments and its mineralogical components. Some physicochemical conditions of the water surrounding these ecosystems have also been studied trying to determine their influence on the diversity of these communities. In that way, mats and sediments distributed among different hypersaline lakes located in salt flats of the Atacama Desert were subjected to massive parallel sequencing of the V4 region of the 16S rRNA genes of Bacteria. A higher diversity in sediment than in mat samples have been found. Lakes that harbor microbial mats have higher salinity than lakes where mats are absent. Proteobacteria and/or Bacteroidetes are the major phyla represented in all samples. An interesting item is the finding of a low proportion or absence of Cyanobacteria sequences in the ecosystems studied, suggesting the possibility that other groups may be playing an essential role as primary producers in these extreme environments. Additionally, the large proportion of 16S rRNA gene sequences that could not be classified at the level of phylum indicates potential new phyla present in these ecosystems. PMID:26224164

  2. Contrasting Imaginaries: The Atacama Desert Perceived from the Region and Observed from the Nation

    Directory of Open Access Journals (Sweden)

    González Pizarro, José Antonio

    2009-12-01

    Full Text Available The author draws on Cornelius Castoriadis’ categories to examine the social imaginaries on the Atacama Desert from the 16th to the 20th centuries. He emphasizes the manner in which different imaginaries came to be constructed historically over time to the point of bringing about a contrast between the imaginary of the country —centered on adversity, sterility and desolation, thereby projecting a textual negativity about Atacama— and that of the region, full of varying symbolisms signifying challenge, occupation and the potentiality of nature. The latter imaginary strengthened the empathy of the northern literature toward the human epic of peopling the desert.

    Basándose en las categorías de Cornelius Castoriadis, el autor examina los imaginarios sociales sobre el desierto de Atacama desde el siglo XVI hasta el XX. Pone de relieve cómo se fueron construyendo en la historia los distintos imaginarios para situarse en la contraposición entre el establecido en la nación chilena —centrado en los elementos de adversidad, esterilidad y lo inhóspito, todo lo cual proyectó una negatividad textual— y el construido en la región, repleto de variados simbolismos en torno al desafío, la ocupación y la potencialidad de la naturaleza, que afianzó la empatía de la literatura nortina con la épica humana del asentamiento en el desierto.

  3. Butterflies of the high altitude Atacama Desert: habitat use and conservation

    OpenAIRE

    Emma eDespland

    2014-01-01

    The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 500 m asl (prepuna, puna and Andean steppe habitats) as well as in high and low altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, be...

  4. Butterflies of the high-altitude Atacama Desert: habitat use and conservation

    OpenAIRE

    Despland, Emma

    2014-01-01

    The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 5000 m asl (prepuna, puna and Andean steppe habitats) as well as in high and low-altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, be...

  5. Chroococcidiopsis sp. strain AAB1, a new model from the Atacama desert for the understanding of extreme UV tolerance in an astrobiological context

    Energy Technology Data Exchange (ETDEWEB)

    Azua-Bustos, A.; Arenas, C. [Pontificia Universidad Catolica de Chile, Santiago (Chile); Paulino-Lima, I G. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Galante, D. [Universidade de Sao Paulo (USP), SP (Brazil)

    2012-07-01

    Full text: The Atacama Desert in northern Chile is the driest and oldest desert on Earth. In a recently published report [Azua-Bustos, 2011] we showed that along its Coastal Range, fog can support hypolithic colonization rates of 80From these hypolithic communities we were able to obtain a previously unknown strain of Chroococcidiopsis which we characterized by morphological and molecular means. Due to the extreme tolerance of cyanobacteria of this genus to UV, and since the Atacama Desert has constantly high UV radiation levels all year long, we propose this strain as a pertinent model for understanding the limits UV tolerance for life as we know it. We have measured the viability of the isolate by using the DEAD/LIVE BacLight kit which allows the detection of dead cells by measuring the loss of integrity of the plasma membrane, and found that it remains almost unchanged with control cultures when desiccated. In addition, desiccated samples readily start new cultures. Transmission electron microscopy (TEM) of desiccated samples show no evident changes compared with controls. Pigments extracts from desiccated samples show a decrease in photosynthetic pigments like Chlorophyll-a, measured by fluorescence spectra and by tissue layer chromatography. Desiccated samples also synthesize sucrose, an intracellular compatible solute known to play a role in desiccation tolerance. As desiccation and extreme UV tolerance are thought to share similar metabolic routes [Rebecchi, 2007], we expect that our isolate (as suggested by preliminary experiments performed with our strain at LNLS in 2010) should be extremely tolerant to UV radiation. Future work include exposition of monolayers of our strain using the VUV line, and the determination of its comparative tolerance levels with a Chroococcidiopsis strain (N76) isolated from the Mojave Desert which we also have in culture. The experiments will consist of different exposition times in order to achieve increasing UV accumulation

  6. Chroococcidiopsis sp. strain AAB1, a new model from the Atacama desert for the understanding of extreme UV tolerance in an astrobiological context

    International Nuclear Information System (INIS)

    Full text: The Atacama Desert in northern Chile is the driest and oldest desert on Earth. In a recently published report [Azua-Bustos, 2011] we showed that along its Coastal Range, fog can support hypolithic colonization rates of 80From these hypolithic communities we were able to obtain a previously unknown strain of Chroococcidiopsis which we characterized by morphological and molecular means. Due to the extreme tolerance of cyanobacteria of this genus to UV, and since the Atacama Desert has constantly high UV radiation levels all year long, we propose this strain as a pertinent model for understanding the limits UV tolerance for life as we know it. We have measured the viability of the isolate by using the DEAD/LIVE BacLight kit which allows the detection of dead cells by measuring the loss of integrity of the plasma membrane, and found that it remains almost unchanged with control cultures when desiccated. In addition, desiccated samples readily start new cultures. Transmission electron microscopy (TEM) of desiccated samples show no evident changes compared with controls. Pigments extracts from desiccated samples show a decrease in photosynthetic pigments like Chlorophyll-a, measured by fluorescence spectra and by tissue layer chromatography. Desiccated samples also synthesize sucrose, an intracellular compatible solute known to play a role in desiccation tolerance. As desiccation and extreme UV tolerance are thought to share similar metabolic routes [Rebecchi, 2007], we expect that our isolate (as suggested by preliminary experiments performed with our strain at LNLS in 2010) should be extremely tolerant to UV radiation. Future work include exposition of monolayers of our strain using the VUV line, and the determination of its comparative tolerance levels with a Chroococcidiopsis strain (N76) isolated from the Mojave Desert which we also have in culture. The experiments will consist of different exposition times in order to achieve increasing UV accumulation

  7. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

    Czech Academy of Sciences Publication Activity Database

    Wierzchos, J.; DiRuggiero, J.; Vítek, Petr; Artieda, O.; Souza-Egipsy, V.; Škaloud, P.; Tisza, M.; Davilla, A. F.; Vilchez, C.; Garbayo, I.; Ascaso, C.

    2015-01-01

    Roč. 6, č. 934 (2015), s. 1-17. ISSN 1664-302X R&D Projects: GA MŠk EE2.3.20.0246 Institutional support: RVO:67179843 Keywords : Atacama Desert * carotenoids * endolithic chlorophototrophs * extreme environment * gypsum * scytonemin Subject RIV: DD - Geochemistry Impact factor: 3.989, year: 2014

  8. Hydrogeology of the lacustrine system of the eastern margin of the Salar the Atacama (Chile); Hidrogeologia del sistema lagunar del margen este del Salar de Atacama (Chile)

    Energy Technology Data Exchange (ETDEWEB)

    Salas, J.; Guimera, J.; Cornella, O.; Aravena, R.; Guzman, E.; Tore, C.; von Igel, W.; Moreno, R.

    2010-07-01

    A hydrogeological conceptual model of the Eastern margin of the Salar de Atacama (Chile) is proposed taking into account climatic, geological, geomorphological, piezometric, chemical and isotopic data. The study establishes the processes that explain the hydrochemical evolution of waters from salty groundwater in the alluvial aquifer located in eastern part of basin until brines at the saline aquifer of the Salar. The main processes associated with this hydrochemical evolution are evaporation and mixing, but water-crust interaction in the discharge areas of the alluvial aquifer associated with the saline wedge also modifies groundwater composition, and plays a role in the dynamics of the evaporitic crusts in the Salar. The existence of low permeability materials near the surface explains the existence of the permanent surface water bodies in the study area. Based on the data collected in the study three different mechanisms are proposed regarding the main sources of water to the lagoons: (1) discharge of saline groundwater from the detrital and volcanic aquifers of the E margin, (2) discharge of surface waters associated to the N area (Burro Muerto channel), and (3) a combination of both previous mechanisms. (Author).

  9. Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr

    Science.gov (United States)

    Gayo, E. M.; Latorre, C.; Santoro, C. M.; Maldonado, A.; de Pol-Holz, R.

    2012-02-01

    Paleoclimate reconstructions reveal that Earth system has experienced sub-millennial scale climate changes over the past two millennia in response to internal/external forcing. Although sub-millennial hydroclimate fluctuations have been detected in the central Andes during this interval, the timing, magnitude, extent and direction of change of these events remain poorly defined. Here, we present a reconstruction of hydroclimate variations on the Pacific slope of the central Andes based on exceptionally well-preserved plant macrofossils and associated archaeological remains from a hyperarid drainage (Quebrada Maní, ∼21° S, 1000 m a.s.l.) in the Atacama Desert. During the late Holocene, riparian ecosystems and farming social groups flourished in the hyperarid Atacama core as surface water availability increased throughout this presently sterile landscape. Twenty-six radiocarbon dates indicate that these events occurred between 1050-680, 1615-1350 and 2500-2040 cal yr BP. Regional comparisons with rodent middens and other records suggest that these events were synchronous with pluvial stages detected at higher-elevations in the central Andes over the last 2500 yr. These hydroclimate changes also coincide with periods of pronounced SST gradients in the Tropical Pacific (La Niña-like mode), conditions that are conducive to significantly increased rainfall in the central Andean highlands and flood events in the low-elevation watersheds at inter-annual timescales. Our findings indicate that the positive anomalies in the hyperarid Atacama over the past 2500 yr represent a regional response of the central Andean climate system to changes in the global hydrological cycle at centennial timescales. Furthermore, our results provide support for the role of tropical Pacific sea surface temperature gradient changes as the primary mechanism responsible for climate fluctuations in the central Andes. Finally, our results constitute independent evidence for comprehending the

  10. Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 years

    Science.gov (United States)

    Gayo, E. M.; Latorre, C.; Santoro, C. M.; Maldonado, A.; de Pol-Holz, R.

    2011-10-01

    Paleoclimate reconstructions reveal that Earth system has experienced sub-millennial scale climate changes over the past two millennia in response to internal/external forcing. Although sub-millennial hydroclimate fluctuations have been detected in the central Andes during this interval, the timing, magnitude, extent and direction of change of these events remain poorly defined. Here, we present a reconstruction of hydroclimate variations on the Pacific slope of the central Andes based on exceptionally well-preserved plant macrofossils and associated archaeological remains from a hyperarid drainage (Quebrada Maní, ~21° S, 1000 m a.s.l.) in the Atacama Desert. During the late Holocene, riparian ecosystems and farming social groups flourished in the hyperarid Atacama core as surface water availability increased throughout this presently sterile landscape. Twenty-six radiocarbon dates indicate that these events occurred between 1050-680, 1615-1350 and 2500-2040 cal yr BP. Regional comparisons with rodent middens and other records suggest that these events were synchronous with pluvial stages detected at higher-elevations in the central Andes over the last 2500 years. These hydroclimate changes also coincide with periods of pronounced SST gradients in the Tropical Pacific (La Niña-like mode), conditions that are conducive to significantly increased rainfall in the central Andean highlands and flood events in the low-elevation watersheds at inter-annual timescales. Our findings indicate that the positive anomalies in the hyperarid Atacama over the past 2500 years represent a regional response of the central Andean climate system to changes in the global hydrological cycle at centennial timescales. Furthermore, our results provide support for the role of tropical Pacific sea surface temperature gradient changes as the primary mechanism responsible for climate fluctuations in the central Andes. Finally, our results constitute independent evidence for comprehending the

  11. Cenozoic evolution of the northwestern Salar de Atacama Basin, northern Chile

    Science.gov (United States)

    Pananont, P.; Mpodozis, C.; Blanco, N.; Jordan, T. E.; Brown, L. D.

    2004-12-01

    Since 90 Ma, the nonmarine Salar de Atacama Basin has been the largest, deepest, and most persistent sedimentary basin of northern Chile. Integration of 200 km of two-dimensional seismic reflection data with surface geological data clarifies Oligocene and Neogene evolution of the northern part of the basin. A normal fault with 6 ± 1 km of vertical separation controlled the western boundary of the basin during the accumulation of the Oligocene-lower Miocene Paciencia Group. The combination of this structure, a similar one in the Calama Basin, and regional structural data suggests that localized extension played an important role within a tectonic environment dominated by margin-perpendicular compression and margin-parallel strike-slip deformation. Seismic data substantiate the surface interpretation that much of the Cordillera de la Sal ridge resulted from diapiric flow of the Paciencia Group. Diapiric flow initiated during the late early Miocene or middle Miocene, associated with a deep reverse fault.

  12. Taxonomic study of extreme halophilic archaea isolated from the "Salar de Atacama", Chile.

    Science.gov (United States)

    Lizama, C; Monteoliva-Sánchez, M; Prado, B; Ramos-Cormenzana, A; Weckesser, J; Campos, V

    2001-11-01

    A large number of halophilic bacteria were isolated in 1984-1992 from the Atacama Saltern (North of Chile). For this study 82 strains of extreme halophilic archaea were selected. The characterization was performed by using the phenotypic characters including morphological, physiological, biochemical, nutritional and antimicrobial susceptibility test. The results, together with those from reference strains, were subjected to numerical analysis, using the Simple Matching (S(SM)) coefficient and clustered by the unweighted pair group method of association (UPGMA). Fifteen phena were obtained at an 70% similarity level. The results obtained reveal a high diversity among the halophilic archaea isolated. Representative strains from the phena were chosen to determine their DNA base composition and the percentage of DNA-DNA similarity compared to reference strains. The 16S rRNA studies showed that some of these strains constitutes a new taxa of extreme halophilic archaea. PMID:11822685

  13. Constraining carbon sources and cycling of endolithic microbial communities in the Atacama Desert

    Science.gov (United States)

    Ziolkowski, L. A.; Slater, G. F.; Davila, A.; Wierzchos, J.

    2010-12-01

    The Atacama Desert, one of the driest places on Earth, is considered a suitable analog for the extremely arid, oxidizing conditions on the surface of Mars. Recent observations suggest the presence of evaporitic deposits on the surface of Mars, such as those found in the Atacama. Halites in the Atacama have been shown to be hygroscopic and are colonized by photosynthetic microbes. While there is considerable evidence for the decrease in abundance and diversity of microbes closer to the hyper-arid core of the Atacama, experimental studies have thus far have yet to estimate the sources of carbon to these communities and the rate at which they cycle. To address these questions, we characterized the isotopic composition (13C and 14C) microbial community biomarkers from four distinct sites in the Atacama. Sites ranged from halites in the hyper-arid core (Yungay, Salar Grande) to volcanic rock and gypsum near the Monturaqui Crater. Our analysis of the phospholipids fatty acids (PLFA) and glycolipid fatty acid (GLFA) methyl esters of the endoliths agreed with previous studies: the abundance and diversity of microbes decreases approaching the hyper-arid core. The total PLFA and GLFA concentrations were lower at Yungay than Salar Grande and higher in the gypsum and volcanic rock samples. Changes in the mole percentage distribution of the PLFA and GLFA illustrated that the endolithic communities inhabiting the volcanic rock and gypsum were more complex than those inhabiting the halites. ∂13C of both PLFA and GLFA showed that non-halite lipids were less depleted in 13C than halite-lipids. This suggested a difference in carbon source or cycling. The 14C content of PLFA and GLFA varied by up to 250 per mil. Endolith PLFA and GLFA from the gypsum had radiocarbon signatures comparable to the modern atmosphere, which suggests that the predominant source of carbon to the system is the modern atmosphere and that lipids are cycling rapidly in this system. However, at the other three

  14. Chaxapeptin, a Lasso Peptide from Extremotolerant Streptomyces leeuwenhoekii Strain C58 from the Hyperarid Atacama Desert.

    Science.gov (United States)

    Elsayed, Somayah S; Trusch, Franziska; Deng, Hai; Raab, Andrea; Prokes, Ivan; Busarakam, Kanungnid; Asenjo, Juan A; Andrews, Barbara A; van West, Pieter; Bull, Alan T; Goodfellow, Michael; Yi, Yu; Ebel, Rainer; Jaspars, Marcel; Rateb, Mostafa E

    2015-10-16

    Lasso peptides are ribosomally synthesized and post-translationally modified peptides (RiPPs) that possess a unique "lariat knot" structural motif. Genome mining-targeted discovery of new natural products from microbes obtained from extreme environments has led to the identification of a gene cluster directing the biosynthesis of a new lasso peptide, designated as chaxapeptin 1, in the genome of Streptomyces leeuwenhoekii strain C58 isolated from the Atacama Desert. Subsequently, 1 was isolated and characterized using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance methods. The lasso nature of 1 was confirmed by calculating its nuclear Overhauser effect restraint-based solution structure. Chaxapeptin 1 displayed a significant inhibitory activity in a cell invasion assay with human lung cancer cell line A549. PMID:26402731

  15. Miniaturized Raman instrumentation detects carotenoids in Mars-analogue rocks from the Mojave and Atacama deserts.

    Science.gov (United States)

    Vítek, P; Jehlička, J; Edwards, H G M; Hutchinson, I; Ascaso, C; Wierzchos, J

    2014-12-13

    This study is primarily focused on proving the potential of miniaturized Raman systems to detect any biomolecular and mineral signal in natural geobiological samples that are relevant for future application of the technique within astrobiologically aimed missions on Mars. A series of evaporites of varying composition and origin from two extremely dry deserts were studied, namely Atacama and Mojave. The samples represent both dry evaporitic deposits and recent evaporitic efflorescences from hypersaline brines. The samples comprise halite and different types of sulfates and carbonates. The samples were analysed in two different ways: (i) directly as untreated rocks and (ii) as homogenized powders. Two excitation wavelengths of miniaturized Raman spectrometers were compared: 532 and 785 nm. The potential to detect carotenoids as biomarkers on Mars compared with the potential detection of carbonaceous matter using miniaturized instrumentation is discussed. PMID:25368344

  16. A new cecidogenous species of Eugnosta Hübner (Lepidoptera: Tortricidae) associated with Baccharis salicifolia (Asteraceae) in the northern Chilean Atacama Desert: Life-history description and phylogenetic inferences.

    Science.gov (United States)

    Vargas, Héctor A; Pollo, Pietro; Basilio, Daniel S; Gonçalves, Gislene L; Moreira, Gilson R P

    2015-01-01

    Eugnosta Hübner, 1825 (Lepidoptera, Tortricidae, Tortricinae, Cochylini, Cochylina) is reported for the first time in Chile. Male and female adults, the pupa, the last-instar larva, and galls of Eugnosta azapaensis Vargas & Moreira, sp. n., are described and illustrated from the Azapa Valley in the northern Atacama Desert. The larvae induce fusiform galls on shoots of the shrub Baccharis salicifolia (Ruiz & Pav.) Pers. (Asteraceae). An assessment of phylogenetic relationships of E. azapaensis with two congeneric species based on mitochondrial DNA is provided. PMID:25781249

  17. Microbial characterization of microbial ecosystems associated to evaporites domes of gypsum in Salar de Llamara in Atacama desert.

    Science.gov (United States)

    Rasuk, Maria Cecilia; Kurth, Daniel; Flores, Maria Regina; Contreras, Manuel; Novoa, Fernando; Poire, Daniel; Farias, Maria Eugenia

    2014-10-01

    The Central Andes in northern Chile contains a large number of closed basins whose central depression is occupied by saline lakes and salt crusts (salars). One of these basins is Salar de Llamara (850 m a.s.l.), where large domed structures of seemingly evaporitic origin forming domes can be found. In this work, we performed a detailed microbial characterization of these domes. Mineralogical studies revealed gypsum (CaSO(4)) as a major component. Microbial communities associated to these structures were analysed by 454 16S rDNA amplicon sequencing and compared between winter and summer seasons. Bacteroidetes Proteobacteria and Planctomycetes remained as the main phylogenetic groups, an increased diversity was found in winter. Comparison of the upper air-exposed part and the lower water-submerged part of the domes in both seasons showed little variation in the upper zone, showing a predominance of Chromatiales (Gammaproteobacteria), Rhodospirillales (Alphaproteobacteria), and Sphingobacteriales (Bacteroidetes). However, the submerged part showed marked differences between seasons, being dominated by Proteobacteria (Alpha and Gamma) and Verrucomicrobia in summer, but with more diverse phyla found in winter. Even though not abundant by sequence, Cyanobacteria were visually identified by scanning electron microscopy (SEM), which also revealed the presence of diatoms. Photosynthetic pigments were detected by high-performance liquid chromatography, being more diverse on the upper photosynthetic layer. Finally, the system was compared with other endoevaporite, mats microbialite and Stromatolites microbial ecosystems, showing higher similitude with evaporitic ecosystems from Atacama and Guerrero Negro. This environment is of special interest for extremophile studies because microbial life develops associated to minerals in the driest desert all over the world. Nevertheless, it is endangered by mining activity associated to copper and lithium extraction; thus, its

  18. Raman imaging in geomicrobiology: endolithic phototrophic microorganisms in gypsum from the extreme sun irradiation area in the Atacama Desert.

    Science.gov (United States)

    Vítek, Petr; Ascaso, Carmen; Artieda, Octavio; Wierzchos, Jacek

    2016-06-01

    The Raman imaging method was successfully applied for mapping the distribution of biomolecules (e.g., pigments) associated with cryptoendolithic and hypoendolithic microorganisms, as well as the inorganic host mineral matrix that forms the habitat for the biota. To the best of our knowledge, this is the first comprehensive study in the field of geomicrobiology based on this technique. The studied microbial ecosystem was located nearly 3000 m above sea level within the driest desert on Earth, the Atacama in Chile. Enhancement of carotenoid Raman signal intensity close to the surface was registered at different areas of endolithic colonization dominated by algae, with cyanobacteria present as well. This is interpreted as an adaptation mechanism to the excessive solar irradiation. On the other hand, cyanobacteria synthesize scytonemin as a passive UV-screening pigment (found at both the hypoendolithic and cryptoendolithic positions). The distribution of the scytonemin Raman signal was mapped simultaneously with the surrounding mineral matrix. Thus, mapping was done of the phototrophic microorganisms in their original microhabitat together with the host rock environment. Important information which was resolved from the Raman imaging dataset of the host rock is about the hydration state of Ca-sulfate, demonstrated on the presence of gypsum (CaSO4·2H2O) and the absence of both anhydrite (CaSO4) and bassanite (CaSO4·1/2H2O). Obtaining combined "in situ" simultaneous information from the geological matrix (inorganic) together with the microbial biomolecules (organic) is discussed and concluded as an important advantage of this technique. We discuss how selection of the laser wavelength (785 and 514.5-nm) influences the Raman imaging results. PMID:27055886

  19. Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile

    Science.gov (United States)

    Fernandez, Ana B.; Rasuk, Maria C.; Visscher, Pieter T.; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G.; Patterson, Molly M.; Ventosa, Antonio; Farias, Maria E.

    2016-01-01

    We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity. PMID:27597845

  20. Phylogenetic Profiling and Diversity of Bacterial Communities in the Death Valley, an Extreme Habitat in the Atacama Desert.

    Science.gov (United States)

    Piubeli, Francine; de Lourdes Moreno, María; Kishi, Luciano Takeshi; Henrique-Silva, Flavio; García, María Teresa; Mellado, Encarnación

    2015-12-01

    The Atacama Desert, one of the driest deserts in the world, represents a unique extreme environmental ecosystem to explore the bacterial diversity as it is considered to be at the dry limit for life. A 16S rRNA gene (spanning the hyper variable V3 region) library was constructed from an alkaline sample of unvegetated soil at the hyperarid margin in the Atacama Desert. A total of 244 clone sequences were used for MOTHUR analysis, which revealed 20 unique phylotypes or operational taxonomic units (OTUs). V3 region amplicons of the 16S rRNA were suitable for distinguishing the bacterial community to the genus and specie level. We found that all OTUs were affiliated with taxa representative of the Firmicutes phylum. The extremely high abundance of Firmicutes indicated that most bacteria in the soil were spore-forming survivors. In this study we detected a narrower diversity as compared to other ecological studies performed in other areas of the Atacama Desert. The reported genera were Oceanobacillus (representing the 69.5 % of the clones sequenced), Bacillus, Thalassobacillus and Virgibacillus. The present work shows physical and chemical parameters have a prominent impact on the microbial community structure. It constitutes an example of the communities adapted to live in extreme conditions caused by dryness and metal concentrations . PMID:26543264

  1. Aqueducts and geoglyphs : the response of Ancient Nasca to water shortages in the desert of Atacama (Peru)

    Science.gov (United States)

    Masini, Nicola; Lasaponara, Rosa

    2016-04-01

    The desert of Atacama is a plateau in South America, covering a 1,000-kilometre strip of land on the Pacific coast, west of the Andes mountains, between Chile and Peru. Due to the confluence of a cold ocean current (the Humboldt Current) along with other climatic factors, connected to the particular topography and geomorphology of the region, Atacama desert is one of the most arid areas of the world. In particular, in Nasca region (Southern Peru) the lack of water was (and still is) due to the following causes: (i) the scarce pluvial precipitations and the (ii) high infiltration capacity, and the consequent yearly significant reduction of the surface water (Schreiber & Lancho Rojas 2009). Over the millennia long periods of drought occurred and frequently the lack of water was persistent for several decades. Despite the arid and extreme nature of the environment, this region was populated by important civilizations, such as Paracas and Nasca, which flourished in the Early Intermediate period (200 BCE-500 AD) (Silvermann & Proulx 2002). In particular the Nasca civilization is well-known for its refined and colourful pottery, characterized by a rich icononographic repertory, and, above all, by the huge and mysterious geoglyphs drawn on the arid plateaus of the Rio Grande de Nasca Basin. In order to practice agriculture, the Nasca developed adequate strategies to cope with hostile environmental factors and water scarcity, building a very efficient aqueduct system. They were aided by the fact that underground water was likely enough close to the surface and accessible by constructing wells and underground aqueducts, known with quechua name of puquios (Schreiber & Lancho Rojas 2009; Lasaponara & Masini 2012a; 2012b) The effectiveness of the techniques of hydraulic engineering depended on the climate and the weather events that sometimes underwent drastic changes, as results of the cyclical phenomenon of El Niño Southern Oscillation (commonly called ENSO). Hence the

  2. Infecção por Enterobius vermicularis em populações agro-pastoris pré-colombianas de San Pedro de Atacama, Chile Enterobius vermicularis infection in pre-Columbian population from San Pedro de Atacama, Chile

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Ferreira

    1989-01-01

    Full Text Available Enterobius vermicularis eggs were found in human coprolites collected from the archaeological site of San Pedro de Atacama, North of Chile, in occupational layers dated from 1,000 BC. Agricultures and herding were begining at this period of time in this region of South America. The paleoparasitological data amplifies the knowledge about the distribution of human oxyuriasis in Pre-Columbian America.

  3. Phytostabilization of arsenic in soils with plants of the genus Atriplex established in situ in the Atacama Desert.

    Science.gov (United States)

    Fernández, Yasna Tapia; Diaz, O; Acuña, E; Casanova, M; Salazar, O; Masaguer, A

    2016-04-01

    In the ChiuChiu village (Atacama Desert, Chile), there is a high concentration of arsenic (As) in the soil due to natural causes related to the presence of volcanoes and geothermal activity. To compare the levels of As and the growth parameters among plants of the same genus, three species of plants were established in situ: Atriplex atacamensis (native of Chile), Atriplex halimus, and Atriplex nummularia. These soils have an As concentration of 131.2 ± 10.4 mg kg(-1), a pH of 8.6 ± 0.1, and an electrical conductivity of 7.06 ± 2.37 dS m(-1). Cuttings of Atriplex were transplanted and maintained for 5 months with periodic irrigation and without the addition of fertilizers. The sequential extraction of As indicated that the metalloid in these soils has a high bioavailability (38 %), which is attributed to the alkaline pH, low organic matter and Fe oxide content, and sandy texture. At day 90 of the assay, the As concentrations in the leaves of A. halimus (4.53 ± 1.14 mg kg(-1)) and A. nummularia (3.85 ± 0.64 mg kg(-1)) were significantly higher than that in A. atacamensis (2.46 ± 1.82 mg kg(-1)). However, the three species accumulated higher levels of As in their roots, indicating a phytostabilization capacity. At the end of the assay, A. halimus and A. nummularia generated 30 % more biomass than A. atacamensis without significant differences in the As levels in the leaves. Despite the difficult conditions in these soils, the establishment of plants of the genus Atriplex is a recommended strategy to generate a vegetative cover that prevents the metalloid from spreading in this arid area through the soil or by wind. PMID:27000320

  4. Application of PIXE to the characterization of vitreous dacites from archaeolgical sites in the Atacama region in northern Chile

    International Nuclear Information System (INIS)

    Geochemical characterization studies using PIXE were carried out on 21 vitreous dacite artifacts from early formative archaeological sites in the Atacama region, in northern Chile, and on 13 samples taken from two potential volcanic sources located within the region. Performing statistical analyses it was possible to obtain elemental concentration patterns for the archaeological samples of this material and match some of these artifacts with the geological source samples

  5. Application of PIXE to the characterization of vitreous dacites from archaeolgical sites in the Atacama region in northern Chile

    Energy Technology Data Exchange (ETDEWEB)

    Morales, J.R.; Cancino, S. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago 1 (Chile); Miranda, P. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago 1 (Chile)], E-mail: pjmirand@gmail.com; Dinator, M.I. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago 1 (Chile); Seelenfreund, A. [Universidad Academia de Humanismo Cristiano, Condell 343, Providencia, Santiago (Chile)

    2007-11-15

    Geochemical characterization studies using PIXE were carried out on 21 vitreous dacite artifacts from early formative archaeological sites in the Atacama region, in northern Chile, and on 13 samples taken from two potential volcanic sources located within the region. Performing statistical analyses it was possible to obtain elemental concentration patterns for the archaeological samples of this material and match some of these artifacts with the geological source samples.

  6. Measurements of Diurnal Variations of Upper Stratospheric ClO with a Ground-based Millimeter-wave Radiometer at Atacama, Chile

    Science.gov (United States)

    Kuwahara, T.; Mizuno, A.; Nagahama, T.; Maezawa, H.; Toriyama, N.; Kojima, Y.

    2010-12-01

    We present the first results of measuring the stratospheric chlorine monoxide (ClO) with a ground-based millimeter-wave radiometer at Atacama highland (23S, 68W, Alt. 4800 m), Chile. The chlorine chemistry plays an essential role in the ozone depletion in the upper stratosphere, and ClO is a key molecule for better understandings of the chlorines chemistry and the ozone recovery processes. However, measurements of the ClO distribution in the upper stratosphere are still limited at present because the ClO spectrum can be measured only in millimeter-wave region and its intensity is considerably weak. Therefore, we had newly installed a ground-based millimeter-wave radiometer equipped with a high sensitivity receiver at Atacama highland, Chile in 2004, and started monitoring the vertical profiles of the stratospheric ClO in 2008. Atacama highland is in a desert area of the northern part of Chile, being one of the most suitable places for millimeter-wave observations. Our instrument equips a superconducting (SIS) mixer receiver whose noise temperature is 170 K in double sideband at 204 GHz and a digital FFT spectrometer covering 1 GHz bandwidth with 70 kHz frequency resolution. We had continuously observed ClO spectra in 204 GHz band every 2 minutes from December 2009 to January 2010, and had obtained 11466 spectra. Vertical profiles of ClO in the upper stratosphere were retrieved from the spectra integrated every 2 hours in local time (LT) taken during 4 and 16 December. From these data, we have clearly detected a diurnal variation of ClO at 40 km. Comparing ClO mixing ratio obtained with our radiometer with those of AURA/MLS taken over our site at 12:00 - 15:00 LT, we had confirmed that they are consistent in range of errors. In this presentation, we will show the details of the diurnal variations of upper stratospheric ClO and comparisons among our results, AURA/MLS and JEM/SMILES.

  7. Evaporation and land surface energy budget at the Salar de Atacama, Northern Chile

    Science.gov (United States)

    Kampf, Stephanie K.; Tyler, Scott W.; Ortiz, Cristián A.; Muñoz, José F.; Adkins, Paula L.

    2005-08-01

    Playa systems are driven by evaporation processes, yet the mechanisms by which evaporation occurs through playa salt crusts are still poorly understood. In this study we examine playa evaporation as it relates to land surface energy fluxes, salt crust characteristics, groundwater and climate at the Salar de Atacama, a 3000 km 2 playa in northern Chile containing a uniquely broad range of salt crust types. Land surface energy budget measurements were taken at eight representative sites on this playa during winter (August 2001) and summer (January 2002) seasons. Measured values of net all-wave radiation were highest at vegetated and rough halite crust sites and lowest over smooth, highly reflective salt crusts. Over most of the Salar de Atacama, net radiation was dissipated by means of soil and sensible heat fluxes. Dry salt crusts tended to heat and cool very quickly, whereas soil heating and cooling occurred more gradually at wetter vegetated sites. Sensible heating was strongly linked to wind patterns, with highest sensible heat fluxes occurring on summer days with strong afternoon winds. Very little energy available at the land surface was used to evaporate water. Eddy covariance measurements could only constrain evaporation rates to within 0.1 mm d -1, and some measured evaporation rates were less than this margin of uncertainty. Evaporation rates ranged from 0.1 to 1.1 mm d -1 in smooth salt crusts around the margin of the salar and from 0.4 to 2.8 mm d -1 in vegetated areas. No evaporation was detected from the rugged halite salt crust that covers the interior of the salar, though the depth to groundwater is less than 1 m in this area. These crusts therefore represent a previously unrecorded end member condition in which the salt crusts form a practically impermeable barrier to evaporation.

  8. Validation of a Clostridium Endospore Viability Assay and Analysis of Greenland Ices and Atacama Desert Soils▿ †

    OpenAIRE

    Yang, Wan-Wan; Ponce, Adrian

    2011-01-01

    A microscopy-based endospore viability assay (micro-EVA) capable of enumerating germinable Clostridium endospores (GCEs) in less than 30 min has been validated and employed to determine GCE concentrations in Greenland ices and Atacama Desert soils. Inoculation onto agarose doped with Tb3+ and d-alanine triggers Clostridium spore germination and the concomitant release of ∼108 molecules of dipicolinic acid (DPA) per endospore, which, under pulsed UV excitation, enables enumeration of resultant...

  9. Evaporation in the Atacama Desert: An empirical study of spatio-temporal variations and their causes

    Science.gov (United States)

    Houston, John

    2006-11-01

    SummaryThe Atacama Desert is hyper-arid, and areas where adequate moisture exists for evaporation are spatially highly restricted. Nevertheless, water resources exist and their evaluation requires knowledge of this elusive but important component of the hydrological cycle. Evaporation may occur in four typical areas: rivers and associated riparian zones, localized springs, large playas and extensive areas of bare soil after infrequent precipitation events. Transpiration is locally possible where moisture is sufficiently close to the surface to allow phreatophytes or scarce grass cover to grow, but virtually no information is available for quantification. Pan evaporation data from 11 stations for the period 1977-1991 is analyzed and complemented by analysis of an evaporation study conducted in the Salar de Atacama during 1987/1988. The results show that pan evaporation, and hence maximum potential evaporation may be considered largely a function of maximum temperature and elevation as well as density of the evaporating fluid. Actual evaporation is limited by available moisture and diminishes rapidly as the level of soil moisture saturation drops below the soil surface, extinguishing at ca. 2 m depth. Evaporation is greatest during the summer, but at higher elevations convective cloudiness develops during January and February reducing evaporating rates at a time when significant precipitation may occur. Inter-annual variations in pan evaporation are considerable and weakly correlated with ENSO, but variations in actual evaporation are damped by comparison. Regression equations are developed which have widespread applicability and may be used to estimate evaporation in areas where no site-specific data exists.

  10. Ignimbrite as a substrate for endolithic life in the hyper-arid Atacama Desert: Implications for the search for life on Mars

    Science.gov (United States)

    Wierzchos, Jacek; Davila, Alfonso F.; Artieda, Octavio; Cámara-Gallego, Beatriz; de los Ríos, Asunción; Nealson, Kenneth H.; Valea, Sergio; Teresa García-González, M.; Ascaso, Carmen

    2013-06-01

    The hyper-arid core of the Atacama Desert in Chile is considered the driest and most life-limited place on Earth, with few habitats capable of sustaining an active microbial ecosystem. As such, it is one of the best terrestrial analogues of the extreme arid conditions on Mars, and an ideal environment to explore survival and biological adaptation strategies as the environment becomes increasingly dry. Here we show that weakly welded rhyolitic ignimbrites in this desert are abundantly colonized by endolithic cyanobacteria and associated heterotrophic bacteria. We propose that the porous ignimbrite interior provides protection from damaging UV radiation and excessive levels of visible light. Rock porosity also favors cell hydration through water retention after scarce rainfall events, even when the surrounding environment remains stubbornly dry. This is the first known example of an endolithic microbial community colonizing ignimbrite rocks in an extremely dry environment. The existence of a habitat capable of supporting abundant phototrophic and heterotrophic communities in an environment that precludes most life forms suggests that, if similar deposits are found on Mars, these should be considered important targets in the search for life. Indeed, ignimbrite rocks have been tentatively identified in Gale Crater, the landing site of the Mars Science Laboratory (MSL) mission and could be directly analyzed by its rover Curiosity.

  11. Rodent middens reveal episodic, long-distance plant colonizations across the hyperarid Atacama Desert over the last 34,000 years

    Science.gov (United States)

    Diaz, Francisca P.; Latorre, Claudio; Maldonado, Antonio; Quade, Jay; Betancourt, Julio L.

    2012-01-01

    Aim To document the impact of late Quaternary pluvial events on plant movements between the coast and the Andes across the Atacama Desert, northern Chile. Location Sites are located along the lower and upper fringes of absolute desert (1100–2800 m a.s.l.), between the western slope of the Andes and the Coastal Ranges of northern Chile (24–26° S). Methods We collected and individually radiocarbon dated 21 rodent middens. Plant macrofossils (fruits, seeds, flowers and leaves) were identified and pollen content analysed. Midden assemblages afford brief snapshots of local plant communities that existed within the rodents' limited foraging range during the several years to decades that it took the midden to accumulate. These assemblages were then compared with modern floras to determine the presence of extralocal species and species provenance. Results Five middens span the last glacial period (34–21 ka) and three middens are from the last glacial–interglacial transition (19–11 ka). The remaining 13 middens span the last 7000 years. Coastal hyperarid sites exhibit low taxonomic richness in middens at 19.3, 1.1, 1.0, 0.9, 0.5 ka and a modern sample. Middens are also dominated by the same plants that occur today. In contrast, middens dated to 28.1, 21.3, 17.3, 3.7 and 0.5 ka contain more species, including Andean extralocals. Precordillera middens (c. 2700 m) show a prominent increase in plant macrofossil richness, along with the appearance of Andean extralocals and sedges at 34.5 and 18.9 ka. Six younger middens dated to 6.1–0.1 ka are similar to the modern local vegetation. Main conclusions Increased species richness and Andean extralocal plants occurred along the current lower fringes of absolute desert during the last glacial–interglacial transition and late Holocene. The absence of soil carbonates indicates the persistence of absolute desert throughout the Quaternary. Colonization by Andean plants could have been accomplished through long-distance seed

  12. Biomineralization of carbonates by Marinococcus albus and Marinococcus halophilus isolated from the Salar de Atacama (Chile).

    Science.gov (United States)

    Rivadeneyra, M A; Delgado, G; Soriano, M; Ramos-Cormenzana, A; Delgado, R

    1999-07-01

    We studied the precipitation of carbonates in 17 strains of moderately halophilic, Gram-positive cocci belonging to two species: Marinococcus halophilus and Marinococcus albus, isolated from the Salar de Atacama (Chile). They were cultivated in solid and liquid laboratory media for 42 days at salt concentrations (wt/vol) of 3%, 7.5%, 15%, and 20%. The bioliths precipitated were studied by X-ray diffraction and scanning electron microscopy. M. halophilus formed crystals at each of the salt concentrations, with a maximum number of strains capable of precipitating carbonates at 7.5% and 15% salt concentrations. M. albus did not precipitate at 20% and showed a maximum at 7.5%. This behavior is similar to that of other gram-positive bacteria and differs from that found in gram-negative bacteria. The bioliths precipitated were spherical, generally isolated, with a size of 10-100 microm, varying with salinity. They were of magnesium calcite (CO3 Ca1-x Mgx) with Mg content increasing with increasing salinity and Mg/Ca molar ratio of the culture medium. These results demonstrate the active role played by M. halophilus and M. albus in the precipitation of carbonates. PMID:10387118

  13. Hydrogeology of the lacustrine system of the eastern margin of the Salar the Atacama (Chile)

    International Nuclear Information System (INIS)

    A hydrogeological conceptual model of the Eastern margin of the Salar de Atacama (Chile) is proposed taking into account climatic, geological, geomorphological, piezometric, chemical and isotopic data. The study establishes the processes that explain the hydrochemical evolution of waters from salty groundwater in the alluvial aquifer located in eastern part of basin until brines at the saline aquifer of the Salar. The main processes associated with this hydrochemical evolution are evaporation and mixing, but water-crust interaction in the discharge areas of the alluvial aquifer associated with the saline wedge also modifies groundwater composition, and plays a role in the dynamics of the evaporitic crusts in the Salar. The existence of low permeability materials near the surface explains the existence of the permanent surface water bodies in the study area. Based on the data collected in the study three different mechanisms are proposed regarding the main sources of water to the lagoons: (1) discharge of saline groundwater from the detrital and volcanic aquifers of the E margin, (2) discharge of surface waters associated to the N area (Burro Muerto channel), and (3) a combination of both previous mechanisms. (Author).

  14. Fluorescent fingerprints of endolithic phototrophic cyanobacteria living within halite rocks in the Atacama Desert.

    Science.gov (United States)

    Roldán, M; Ascaso, C; Wierzchos, J

    2014-05-01

    Halite deposits from the hyperarid zone of the Atacama Desert reveal the presence of endolithic microbial colonization dominated by cyanobacteria associated with heterotrophic bacteria and archaea. Using the λ-scan confocal laser scanning microscopy (CLSM) option, this study examines the autofluorescence emission spectra produced by single cyanobacterial cells found inside halite rocks and by their photosynthetic pigments. Photosynthetic pigments could be identified according to the shapes of the emission spectra and wavelengths of fluorescence peaks. According to their fluorescence fingerprints, three groups of cyanobacterial cells were identified within this natural extreme microhabitat: (i) cells producing a single fluorescence peak corresponding to the emission range of phycobiliproteins and chlorophyll a, (ii) cells producing two fluorescence peaks within the red and green signal ranges, and (iii) cells emitting only low-intensity fluorescence within the nonspecific green fluorescence signal range. Photosynthetic pigment fingerprints emerged as indicators of the preservation state or viability of the cells. These observations were supported by a cell plasma membrane integrity test based on Sytox Green DNA staining and by transmission electron microscopy ultrastructural observations of cyanobacterial cells. PMID:24610843

  15. Evidence for nonallopatric speciation among closely related sympatric Heliotropium species in the Atacama Desert.

    Science.gov (United States)

    Luebert, Federico; Jacobs, Pit; Hilger, Hartmut H; Muller, Ludo A H

    2014-02-01

    The genetic structure of populations of closely related, sympatric species may hold the signature of the geographical mode of the speciation process. In fully allopatric speciation, it is expected that genetic differentiation between species is homogeneously distributed across the genome. In nonallopatric speciation, the genomes may remain undifferentiated to a large extent. In this article, we analyzed the genetic structure of five sympatric species from the plant genus Heliotropium in the Atacama Desert. We used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of these species and evaluate their genetic differentiation as well as the number of loci subject to positive selection using divergence outlier analysis (DOA). The five species form distinguishable groups in the genetic space, with zones of overlap, indicating that they are possibly not completely isolated. Among-species differentiation accounts for 35% of the total genetic differentiation (F ST = 0.35), and F ST between species pairs is positively correlated with phylogenetic distance. DOA suggests that few loci are subject to positive selection, which is in line with a scenario of nonallopatric speciation. These results support the idea that sympatric species of Heliotropium sect. Cochranea are under an ongoing speciation process, characterized by a fluctuation of population ranges in response to pulses of arid and humid periods during Quaternary times. PMID:24558582

  16. Fluorescent Fingerprints of Endolithic Phototrophic Cyanobacteria Living within Halite Rocks in the Atacama Desert

    Science.gov (United States)

    Ascaso, C.; Wierzchos, J.

    2014-01-01

    Halite deposits from the hyperarid zone of the Atacama Desert reveal the presence of endolithic microbial colonization dominated by cyanobacteria associated with heterotrophic bacteria and archaea. Using the λ-scan confocal laser scanning microscopy (CLSM) option, this study examines the autofluorescence emission spectra produced by single cyanobacterial cells found inside halite rocks and by their photosynthetic pigments. Photosynthetic pigments could be identified according to the shapes of the emission spectra and wavelengths of fluorescence peaks. According to their fluorescence fingerprints, three groups of cyanobacterial cells were identified within this natural extreme microhabitat: (i) cells producing a single fluorescence peak corresponding to the emission range of phycobiliproteins and chlorophyll a, (ii) cells producing two fluorescence peaks within the red and green signal ranges, and (iii) cells emitting only low-intensity fluorescence within the nonspecific green fluorescence signal range. Photosynthetic pigment fingerprints emerged as indicators of the preservation state or viability of the cells. These observations were supported by a cell plasma membrane integrity test based on Sytox Green DNA staining and by transmission electron microscopy ultrastructural observations of cyanobacterial cells. PMID:24610843

  17. Facilitation of endolithic microbial survival in the hyperarid core of the Atacama Desert by mineral deliquescence

    Science.gov (United States)

    Davila, Alfonso F.; Gómez-Silva, Benito; de Los Rios, Asunción; Ascaso, Carmen; Olivares, Hector; McKay, Christopher P.; Wierzchos, Jacek

    2008-03-01

    The hyperarid core of the Atacama Desert is considered the dry limit for life on Earth. Soils in this region have very low abundance of heterotrophic bacteria and are practically barren of photosynthetic microorganisms because of the extreme dry conditions (≤2 mm a-1 rainfall). However, relatively abundant endolithic communities of cyanobacteria (Chroococcidiopsis) occur within halite crusts in paleolake evaporitic deposits. By means of continuous monitoring of the microclimate conditions (temperature, relative humidity, water vapor density, wetness, and photosynthetically active radiation) inside and around the halite crusts, we demonstrate here that water vapor condenses within the pore space of the halite at relative humidity (RH) levels that otherwise hinder the occurrence of liquid water in the surrounding environment. Water condensation occurs at RH >75%, which corresponds to the deliquescence point of halite. We have estimated a total of 57 deliquescence events (i.e., water condensation) within the halite crusts, as opposed to only 1 liquid water event outside. These wet events resulted in a total of 213.8 h of potential photosynthetic activity for the endolithic microorganisms versus only 6 h for organisms outside the halite crusts. Halite crusts may therefore represent the last available niche for photosynthetic activity in extreme arid environments on Earth.

  18. Mechanisms for Planetary Spherules Formation and Alteration: Salar Grande, Chile -- An Example of Volcanic/Aqueous Processes Interactions

    Science.gov (United States)

    Ukstins Peate, I.; Cabrol, N. A.; Grin, E. A.; French, R.; Dressing, C.; Franklin, T.; Parsons, K.; Piatek, J. L.; Chong, G.

    2009-03-01

    Silica nodules and hematite spherules are observed at Salar Grande and Monturaqui, Atacama Desert, Chile. The Planetary Spherules Project investigates formation, deposition and alteration processes as analogs to Gusev Crater and Meridiani, Mars.

  19. EVIDENCIA DE TEMPRANAS MANIFESTACIONES RUPESTRES EN LA COSTA DEL DESIERTO DE ATACAMA (25° S (Evidence of Early Rock Art on the Coast of the Atacama Desert (25° S

    Directory of Open Access Journals (Sweden)

    José Castelleti

    2015-10-01

    Full Text Available Los análisis llevados a cabo sobre pictografías rupestres de la comuna de Taltal, en la costa del desierto de Atacama en Chile, tradicionalmente descritas como «estilo El Médano», han permitido datarlas por AMS en 7882 ± 160 A. P. (7022-6509 a. C. 68 %, 7172-6412 a. C. 95 %, hacia el traslape Arcaico Temprano/Medio; información corroborada con la datación arqueomagnética llevada a cabo sobre muestras del mismo panel radiocarbónicamente fechado, la cual arroja rangos de 9132-9065 a. C., 6492-6426 a. C. y 5203-5114 a. C. (65 % de confianza. Las peculiaridades tecnoeconómicas que evidencian la conformación de la mezcla de las pinturas rupestres, permiten interpretar para la zona el desarrollo de un notable nodo ocupacional arcaico, plenamente adaptado al bioclima costero; conformado por grupos humanos que, si bien diferenciados localmente, también reprodujeron una identidad común centrada en la simbología del color rojo obtenido de la hematita, arcillas y, probablemente también, de arbustos locales como el churco, parte crucial en la materialización de metáforas de animales y escenas marinas socialmente compartidas y en la semantización del espacio. ENGLISH: AMS dating of cave art located in the Taltal district, on the coast of the Atacama desert in Chile, produced dates of 7882 ± 160 BP (7022-6509 BC 68%, 7172-6412 BC 95%, placing it in the Early/Middle Archaic period. This finding is further supported by archaeomagnetic dates on samples from the same panel, which produced three time intervals all consistent with the AMS dates: 9132-9065 BC, 6492-6426 BC, and 5203-5114 BC (65% confidence. Techno-economic analysis of the cave paintings suggests the Taltal area was an important Archaic settlement cluster, inhabited by different groups who were fully adapted to the coastal bioregion and who shared a common symbolic identity. The color red, produced from hematite, clays, and probably local shrubs such as churco, played a crucial

  20. El género Cymatoceras (Nautilida) en el Cretácico Inferior de la Cuenca de Atacama, norte de Chile The genus Cymatoceras (Nautilida) in the Lower Cretaceous of the Atacama Basin, northern Chile

    OpenAIRE

    Marcela Cichowolski; Francisco A. Mourgues; Ernesto Pérez d'A

    2004-01-01

    Se describen restos fragmentarios de nautílidos del género Cymatoceras Hyatt, provenientes de estratos barremianos de la Cuenca de Atacama, norte de Chile. Los especímenes corresponden a dos taxones: Cymatoceras sp. del Barremiano tardío alto, cuya preservación es deficiente, aunque su tipo de ornamentación, con costillas gruesas y un seno ventral muy marcado, es sólo conocida, hasta el momento, en este taxón y Cymatoceras cf. perstriatum (Steuer), del Barremiano tardío. El material chileno e...

  1. MEDIR, AMOJONAR, REPARTIR: TERRITORIALIDADES Y PRÁCTICAS DEMARCATORIAS EN EL CAMINO INCAICO DE ATACAMA (II REGIÓN, CHILE) MEASURING, POSTING, ALLOCATION: TERRITORIALITY AND DEMARCATION PRACTICES ALONG THE ATACAMA INKA ROAD (II REGION, CHILE)

    OpenAIRE

    Cecilia Sanhueza Tohá

    2004-01-01

    A partir del registro arqueológico de los caminos incaicos de la antigua región de Atacama (II Región, Chile), se desarrolla un análisis etnohistórico interpretativo de los denominados hitos, mojones o topus, identificados como un rasgo característico de la vialidad estatal. Desde los antecedentes aportados por la literatura colonial y los vocabularios indígenas, se incursiona en los contenidos semánticos asociados a este tipo de estructuras, estableciendo que estos aparentes señalizadores de...

  2. Interactions between basement and cover during the evolution of the Salar de Atacama Basin, northern Chile

    Directory of Open Access Journals (Sweden)

    Nelson Muñoz

    2002-07-01

    Full Text Available ABSTRACT A reinterpretation of the structural style on the eastern Cordillera Domeyko and the adjacent Salar de Atacama Basin reveals the existence of west-dipping, high-angle, thrust-faults extending below the Cordillera Domeyko and Cordón de Lila, resulting from inversion of Cretaceous extensional faults, that transferred west-ward their displacement into the cover, generating fault-propagation and detachment folds. The most conspicuous of these structures is the Cordillera de la Sal. Contractional structures in the Cordillera Domeyko involved a Paleozoic crystalline, volcanic, and sedimentary, uplifted basement. Seismic reflection sections and available surface geology allows to study the interactions between development of the thick-skinned basement structures, sedimentation within the basin, and the thin-skinned deformation in the sedimentary cover. Geometry of the units in the basin continuously modified. Anticline growth above basement thrust-faults locally controlled syn-thrusting sequences, and generated progressive unconformities. Stratigraphic architecture in the basin seems to have been mainly controlled by tectonic activity. Tectonism generated accommodation space, altered base levels, and controlled source areas. The stratigraphy and geometry of the basin deposits resulted mainly from the succession of the following events: local extensional subsidence during the Early to Late Cretaceous, uplift of the Cordillera Domeyko during the latest Cretaceous to Miocene, uplift of the Puna, and subsidence probably caused by flexural response of the lithosphere during thrust-sheet loading, and sediment accumulationRESUMEN Interacciones entre el basamento y la cobertura durante la evolución de la Cuenca del Salar de Atacama, norte de Chile. La reinterpretación del estilo estructural del borde oriental de la Cordillera Domeyko y de la adyacente cuenca del Salar de Atacama, basada en el análisis de la geología de superficie y de perfiles s

  3. Miocene-Quaternary structural evolution of the Uyuni-Atacama region, Andes of Chile and Bolivia

    Science.gov (United States)

    Tibaldi, A.; Corazzato, C.; Rovida, A.

    2009-06-01

    We describe the Miocene-Quaternary geological-structural evolution of the region between the Salar de Uyuni and de Atacama, Andes of Chile and Bolivia. We recognized four main tectonic events based on fold geometry, fault kinematics and stratigraphic data. The oldest event, of Miocene age, is characterized by folding and reverse faulting of the sedimentary successions with an E-W direction of shortening in the northern part of the studied area and a WNW-ESE shortening in the southern part. The following two events, of Pliocene age, are characterized by lower shortening amounts; they occurred first by reverse faulting with a NW-SE-trending greatest principal stress ( σ1, computed with striated fault planes) and a vertical least principal stress ( σ3), followed by pervasive strike-slip faulting with the same NW-SE-trending σ1 and a horizontal NE-SW σ3. The fourth event, dating to the late Pliocene-Quaternary is characterized by normal faulting: the σ3 still trends NE-SW, whereas the intermediate principal stress σ2 exchanged with σ1. Volcanism accompanied both the contractional, transcurrent and extensional tectonic phases. The Mio-Pliocene compression appears directly linked to a rapid convergence and an apparently important coupling between the continental and oceanic plates. The E-W to WNW-ESE direction of shortening of the Miocene structures and the NW-SE σ1 of the Pliocene structures seem to be more linked to an intra-Andean re-orientation of structures following the WNW-directed absolute motion of the South-American Plate. The extensional deformations can be interpreted as related to gravity forces affecting the highest parts of the volcanic belt in a sort of asymmetrical (SW-ward) collapse of the belt.

  4. Complete genome sequence of Microbacterium sp. CGR1, bacterium tolerant to wide abiotic conditions isolated from the Atacama Desert.

    Science.gov (United States)

    Mandakovic, Dinka; Cabrera, Pablo; Pulgar, Rodrigo; Maldonado, Jonathan; Aravena, Pamela; Latorre, Mauricio; Cambiazo, Verónica; González, Mauricio

    2015-12-20

    Microbacterium sp. CGR1 (RGM2230) is an isolate from the Atacama Desert that displays a wide pH, salinity and temperature tolerance. This strain exhibits riboflavin overproducer features and traits for developing an environmental arsenic biosensor. Here, we report the complete genome sequence of this strain, which represents the first genome of the genus Microbacterium sequenced and assembled in a single contig. The genome contains 3,634,864bp, 3299 protein-coding genes, 45 tRNAs, six copies of 5S-16S-23S rRNA and a high genome average GC-content of 68.04%. PMID:26521698

  5. Oxalate formation under the hyperarid conditions of the Atacama desert as a mineral marker to provide clues to the source of organic carbon on Mars

    Science.gov (United States)

    Cheng, Z. Y.; Fernández-Remolar, D. C.; Izawa, M. R. M.; Applin, D. M.; Chong Díaz, M.; Fernandez-Sampedro, M. T.; García-Villadangos, M.; Huang, T.; Xiao, L.; Parro, V.

    2016-06-01

    In this study, we report the detection and characterization of the organic minerals weddellite (CaC2O4 · 2H2O) and whewellite (CaC2O4 · H2O) in the hyperarid, Mars-like conditions of the Salar Grande, Atacama desert, Chile. Weddellite and whewellite are commonly of biological origin on Earth and have great potential for preserving records of carbon geochemistry and possible biological activity on Mars if they are present there. Weddellite and whewellite have been found as secondary minerals occurring inside the lower detrital unit that fills the Salar Grande basin. The extremely low solubility of most oxalate minerals inhibits detection of oxalate by ion chromatography (IC). Crystalline oxalates, including weddellite and whewellite, were detected by X-ray diffraction (XRD). The association of weddellite with surface biota and its presence among subsurface detrital materials suggest the potential of a biological origin for Salar Grande weddellite and whewellite. In this regard, biological activity is uniquely capable of concentrating oxalates at levels detectable by XRD. The complementary detection of oxalate-bearing phases through IC in the upper halite-rich unit suggests the presence of a soluble oxalate phase in the basin that is not detected by XRD. The formation, transport, and concentration of oxalate in the Salar Grande may provide a geochemical analogue for oxalate-bearing minerals recently suggested to exist on Mars.

  6. Aqueducts and geoglyphs : the response of Ancient Nasca to water shortages in the desert of Atacama (Peru)

    Science.gov (United States)

    Masini, Nicola; Lasaponara, Rosa

    2016-04-01

    The desert of Atacama is a plateau in South America, covering a 1,000-kilometre strip of land on the Pacific coast, west of the Andes mountains, between Chile and Peru. Due to the confluence of a cold ocean current (the Humboldt Current) along with other climatic factors, connected to the particular topography and geomorphology of the region, Atacama desert is one of the most arid areas of the world. In particular, in Nasca region (Southern Peru) the lack of water was (and still is) due to the following causes: (i) the scarce pluvial precipitations and the (ii) high infiltration capacity, and the consequent yearly significant reduction of the surface water (Schreiber & Lancho Rojas 2009). Over the millennia long periods of drought occurred and frequently the lack of water was persistent for several decades. Despite the arid and extreme nature of the environment, this region was populated by important civilizations, such as Paracas and Nasca, which flourished in the Early Intermediate period (200 BCE-500 AD) (Silvermann & Proulx 2002). In particular the Nasca civilization is well-known for its refined and colourful pottery, characterized by a rich icononographic repertory, and, above all, by the huge and mysterious geoglyphs drawn on the arid plateaus of the Rio Grande de Nasca Basin. In order to practice agriculture, the Nasca developed adequate strategies to cope with hostile environmental factors and water scarcity, building a very efficient aqueduct system. They were aided by the fact that underground water was likely enough close to the surface and accessible by constructing wells and underground aqueducts, known with quechua name of puquios (Schreiber & Lancho Rojas 2009; Lasaponara & Masini 2012a; 2012b) The effectiveness of the techniques of hydraulic engineering depended on the climate and the weather events that sometimes underwent drastic changes, as results of the cyclical phenomenon of El Niño Southern Oscillation (commonly called ENSO). Hence the

  7. Butterflies of the high altitude Atacama Desert: habitat use and conservation

    Directory of Open Access Journals (Sweden)

    Emma eDespland

    2014-09-01

    Full Text Available The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 500 m asl (prepuna, puna and Andean steppe habitats as well as in high and low altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life-history strategies and relationships with host plants.

  8. Butterflies of the high-altitude Atacama Desert: habitat use and conservation.

    Science.gov (United States)

    Despland, Emma

    2014-01-01

    The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 5000 m asl (prepuna, puna and Andean steppe habitats) as well as in high and low-altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life history strategies and relationships with host plants. PMID:25309583

  9. Weathering and solute transport to the Salar de Atacama, northern Chile

    Science.gov (United States)

    Hynek, S. A.; Munk, L. A.; Boutt, D. F.

    2013-12-01

    The Salar de Atacama is situated in a tectonic basin on the Tropic of Capricorn, adjacent to the Central Andean Volcanic Zone in hyper-arid northern Chile. This basin has been hydrographically closed for most, if not all, of the Cenozoic. Since the late Miocene, chemical sediment (primarily halite, but also sulphate) and Na-Cl brines have accumulated. The volume of these deposits provides a constraint on long term average solute fluxes. We have undertaken an extensive multiple isotope study of surface and shallow groundwater in the basin to constrain processes and pathways affecting solute fluxes to the basin. By comparing these inflow waters to brackish waters and brines, we are able to place constraints on modern weathering with the ultimate goal of comparing it to longer term fluxes estimated from the geologic record. The volcanic arc and extensive large volume silicic magma chambers provide potential sources of solutes to the basin which are not a direct result of surficial weathering (hydrothermal waters/magmatic brines). For most freshwater, this possibility is ruled out. Oxygen and hydrogen isotopes in water provide no strong evidence for high temperature water-rock interaction. Further, the isotopic composition of helium dissolved in groundwater demonstrates that most groundwater carries an atmospheric signal (air saturated water), though some evidence for the influence of magmatic brines is found in shallow groundwater with high concentrations of helium-3, methane, and carbon dioxide. The strontium isotopic composition of waters and brines exhibits geographic variation that is related to at least four sources; 1) weathering of Andean volcanic arc along the eastern margin of the basin (87/86 ratios ~0.708), 2) thermal waters sourced in the northern headwaters of the Río San Pedro and 3) high calcium weathering fluxes from the Cordón de Lila on the southern margin of the basin, both of which have more radiogenic 87/86 ratios than the Andean volcanic arc

  10. Shallow water heterobranch sea slugs (Gastropoda: Heterobranchia) from the Región de Atacama, northern Chile.

    Science.gov (United States)

    Araya, Juan Francisco; Valdés, Ángel

    2016-01-01

    The coast of northern Chile has been sparsely studied in regards to its invertebrate fauna, with just a few works reviewing the distribution of local mollusks. This work presents a survey of the shallow water heterobranch sea slugs currently occurring around the port of Caldera (27 °S), in the Región de Atacama, northern Chile. Eight species of sea slugs were found in this study: Aplysiopsis cf. brattstroemi (Marcus, 1959), Baptodoris peruviana (d'Orbigny, 1837), Diaulula variolata (d'Orbigny, 1837), Doris fontainii d'Orbigny, 1837, Onchidella marginata (Couthouy in Gould, 1852), Phidiana lottini (Lesson, 1831), Tyrinna delicata (Abraham, 1877) and the new species Berthella schroedli sp. nov., described herein. All of the species found in the area are endemic to South America, having distributions in the southeastern Pacific and South Atlantic Oceans, from Ancash, Perú to Peninsula Valdés, Argentina, and two of them represent species which are endemic to the Chilean coasts (Aplysiopsis cf. brattstroemi and Berthella schroedli). The finding of a previously undescribed species emphasizes the need of further surveys, particularly in subtidal and deeper waters, in order to improve the knowledge on this neglected fauna in Atacama. PMID:27168975

  11. Shallow water heterobranch sea slugs (Gastropoda: Heterobranchia) from the Región de Atacama, northern Chile

    Science.gov (United States)

    Valdés, Ángel

    2016-01-01

    The coast of northern Chile has been sparsely studied in regards to its invertebrate fauna, with just a few works reviewing the distribution of local mollusks. This work presents a survey of the shallow water heterobranch sea slugs currently occurring around the port of Caldera (27 °S), in the Región de Atacama, northern Chile. Eight species of sea slugs were found in this study: Aplysiopsis cf. brattstroemi (Marcus, 1959), Baptodoris peruviana (d’Orbigny, 1837), Diaulula variolata (d’Orbigny, 1837), Doris fontainii d’Orbigny, 1837, Onchidella marginata (Couthouy in Gould, 1852), Phidiana lottini (Lesson, 1831), Tyrinna delicata (Abraham, 1877) and the new species Berthella schroedli sp. nov., described herein. All of the species found in the area are endemic to South America, having distributions in the southeastern Pacific and South Atlantic Oceans, from Ancash, Perú to Peninsula Valdés, Argentina, and two of them represent species which are endemic to the Chilean coasts (Aplysiopsis cf. brattstroemi and Berthella schroedli). The finding of a previously undescribed species emphasizes the need of further surveys, particularly in subtidal and deeper waters, in order to improve the knowledge on this neglected fauna in Atacama.

  12. Fungi associated with rocks of the Atacama Desert: taxonomy, distribution, diversity, ecology and bioprospection for bioactive compounds.

    Science.gov (United States)

    Gonçalves, Vívian N; Cantrell, Charles L; Wedge, David E; Ferreira, Mariana C; Soares, Marco Aurélio; Jacob, Melissa R; Oliveira, Fabio S; Galante, Douglas; Rodrigues, Fabio; Alves, Tânia M A; Zani, Carlos L; Junior, Policarpo A S; Murta, Silvane; Romanha, Alvaro J; Barbosa, Emerson C; Kroon, Erna G; Oliveira, Jaquelline G; Gomez-Silva, Benito; Galetovic, Alexandra; Rosa, Carlos A; Rosa, Luiz H

    2016-01-01

    This study assessed the diversity of cultivable rock-associated fungi from Atacama Desert. A total of 81 fungal isolates obtained were identified as 29 Ascomycota taxa by sequencing different regions of DNA. Cladosporium halotolerans, Penicillium chrysogenum and Penicillium cf. citrinum were the most frequent species, which occur at least in four different altitudes. The diversity and similarity indices ranged in the fungal communities across the latitudinal gradient. The Fisher-α index displayed the higher values for the fungal communities obtained from the siltstone and fine matrix of pyroclastic rocks with finer grain size, which are more degraded. A total of 23 fungal extracts displayed activity against the different targets screened. The extract of P. chrysogenum afforded the compounds α-linolenic acid and ergosterol endoperoxide, which were active against Cryptococcus neoformans and methicillin-resistance Staphylococcus aureus respectively. Our study represents the first report of a new habitat of fungi associated with rocks of the Atacama Desert and indicated the presence of interesting fungal community, including species related with saprobes, parasite/pathogen and mycotoxigenic taxa. The geological characteristics of the rocks, associated with the presence of rich resident/resilient fungal communities suggests that the rocks may provide a favourable microenvironment fungal colonization, survival and dispersal in extreme conditions. PMID:26235221

  13. Application of artificial neural networks as a tool for moisture prediction in microbially colonized halite in the Atacama Desert

    Science.gov (United States)

    Wierzchos, K.; Cancilla, J. C.; Torrecilla, J. S.; Díaz-Rodríguez, P.; Davila, A. F.; Ascaso, C.; Nienow, J.; McKay, C. P.; Wierzchos, J.

    2015-06-01

    The Atacama Desert is the driest and one of the most life-limiting places on Earth. Despite the extreme conditions, microbial endolithic communities have been found inside halite rocks. The presence of these microbial communities is possible due to the hygroscopic properties of evaporitic rocks composed of sodium chloride. It is important to elucidate every possible water source in such a hyperarid environment. Therefore, in the present study, an artificial neural network (ANN) based model has been designed to predict the presence of liquid water on the surface of halite pinnacles. The model predicts the moisture formation using two basic meteorological variables, air temperature, and air relative humidity. ANNs have been successfully employed for the first time as a tool for predicting the appearance of liquid water, a key factor for the endolithic microbial communities living in the driest part of the Atacama Desert. The model developed is able to correctly predict the formation of water on the surface of the halite pinnacles 83% of the cases. We anticipate the future application of this model as an important tool for the prediction of the water availability and therefore potential habitability of lithic substrates in extreme environments on Earth and perhaps elsewhere.

  14. The Optical/Infrared Astronomical Quality of High Atacama Sites. I. Preliminary Results of Optical Seeing

    OpenAIRE

    Giovanelli, Riccardo; Darling, Jeremy; Sarazin, Marc; Yu, Jennifer; Harvey, Paul; Henderson, Charles; Hoffman, William; Keller, Luke; Barry, Don; Cordes, James; Eikenberry, Stephen; Gull, George; Harrington, Joseph; Smith, J D; Stacey, Gordon

    2001-01-01

    The region surrounding the Llano de Chajnantor, a high altitude plateau in the Atacama Desert in northern Chile, has caught the attention of the astronomical community for its potential as an observatory site. Combining high elevation and extremely low atmospheric water content, the Llano has been chosen as the future site of the Atacama Large Millimeter Array. We have initiated a campaign to investigate the astronomical potential of the region in the optical/infrared. Here, we report on an a...

  15. Long-term denudation rates from the Central Andes (Chile estimated from a Digital Elevation Model using the Black Top Hat function and Inverse Distance Weighting: implications for the Neogene climate of the Atacama Desert Tasas de denudación de largo tiempo en los Andes Centrales, Chile, estimadas a partir de un modelo digital de elevación usando la función 'Top Hat' por cierre y la interpolación ponderada por el inverso de la distancia: implicancias del clima Neógeno del Desierto de Atacama

    Directory of Open Access Journals (Sweden)

    Rodrigo Riquelme

    2008-01-01

    Full Text Available A methodology for determining long-term denudation rates from morphologic markers in a Digital Elevation Model (DEM is checked by a comparative study of two drainage basins in the PrecordiUera of the Central Andes. In both cases the initial configuration of an incised pediment surface has been restored by using two different methods: the Black Top Hat (BTH function and the Inverse Distance Weighting (IDW interpolation. Where vertical incision and hillslope erosion are recorded, the IDW appears to be the most adequate to reconstitute the pediment surfaces. Conversely, where only vertical incision is observed, the BTH describes more precisely the former pediment surfaces and it is easier to solve. By subtracting the DEM from the reconstructed marker we calculated an eroded volume, and estimated its uncertainty by considering Root Mean Square Error (RMSE and DEM grid error. For the last ~10 Myr we obtained long-term denudation rates of 7.33±1.6 m/Myr in the San Andrés drainage basin and 13.59±1.9 m/Myr in the El Salado drainage basin. These estimations are largely in agreement with other reported estimates of long-term denudation rates in the Atacama Desert. Comparison with long-term denudation rates reported in a wide range of climatic regimes suggests that our estimates cannot be explained by the current rainfall in the PrecordiUera. However they could be explained by a rainfall similar to that reported 40 km to the east in the Puna. This suggests that during the time span concerned the geomorphologic evolution of the study area, this evolution is dominated by an orographically controlled rainfall pattern. The preserved pediment surface and the small long term denudation rates determined in this study also indicate that the PrecordiUera was never reached by humid tropical air masses and precipitation as currently observed in the Altiplano during the summer monthsUna metodología para determinar tasas de denudación de largo tiempo a partir de

  16. A small, new gerbil-mouse Eligmodontia (Rodentia: Cricetidae) from dunes at the coasts and deserts of north-central Chile: molecular, chromosomic, and morphological analyses.

    Science.gov (United States)

    Spotorno, Angel E; Zuleta, Carlos; Walker, Laura I; Manriquez, German; Valladares, Pablo; Marin, Juan C

    2013-01-01

    A small, new species of gerbil rodents of the genus Eligmodontia from the southwestern dunes of the Atacama Desert in northern Chile is described; the genus had not been reported for this western lowland region. Our description is based on cytogenetic and molecular data, as well as cranial and external morphology. In order to support this hypothesis, we studied 27 specimens captured in Playa Los Choros (Coquimbo) and Copiapó (Atacama), comparing them with samples of all the extant species of the genus. Nineteen individuals consistently showed 2N=50, FN=48, with telocentric chromosomes and G-bands identical to those of the geographically northeastern E. hirtipes; these two groups were geographically separated by E. puerulus (2N = 34, FN = 48). The phylogenetic analysis of 56 Eligmodontia cytochrome-b gene sequences yielded a maximum-likelihood phylogenetic tree where the new species formed a divergent and well-supported clade within the genus, which was also confirmed by unweighted parsimony, minimum evolution, and Bayesian analyses. The new species has K2P genetic distances of 12.8% from the geographically distant E. hirtipes, and 10.3% from E. puerulus. Axes 1 and 2 of Principal Component Analysis based on 12 body and skull measurements clearly separated the new species, the latter having a smaller head+body length (70.6 +/- 3.4 mm, n = 17) and lower weight (11.9 +/- 1.9 g, n = 20). We provide strong evidence to recognize a distinct new western lineage within Eligmodontia genus, Eligmodontia dunaris sp. nov., for which we give a complete taxonomic description and a hypothetical biogeographic scenario. The new species should be considered endangered, due to its level of endemism, its low population numbers (which can be occasionally increased after a blooming desert) and its fragile dry habitat patchily distributed near the Atacama Desert. PMID:25250459

  17. Genetic Characterization of Old Grapevines collected in Oases of the Atacama Desert Caracterización Genética de Vides Antiguas colectadas en Oasis del Desierto de Atacama

    Directory of Open Access Journals (Sweden)

    Ingrid Poblete

    2011-09-01

    Full Text Available Old grapevine (Vitis vinifera L. accessions are a source of genes that could be rescued for use per se or in modern breeding programs. The first step in this rescuing is collecting and characterizing the germplasm from a particular region. This study presents the genetic characterization of 21 grapevine accessions collected from the Atacama Desert in the far North of Chile. Characterization was based on 12 microsatellites (Simple Sequence Repeats, or SSRs supplemented with Amplified Fragment Length Polymorphic (AFLP markers. Most of the collected accessions produced red berries and shared the genetic characteristics of the cv. País, an old genotype found throughout America. However, among those red-berried accessions, one showed a severe abortive phenotype (22S7, and another (6S4 differed from ‘País’ in one allele. Both could be examples of somatic mutations, even though no variations in their AFLP patterns were found. On the other hand, the only accession with red berries that exhibited genetic characteristics different from those of ‘País’ (5CN corresponded to ‘Gros Colman’, a supposedly Georgian genotype introduced to this region by the mid-20th century. Greater genetic diversity was detected among the white and pink accessions, which were classified into five clades based on their SSR allelic patterns. Of these genotypes, 11Si was identified as ‘Emperatriz’ or ‘Red Seedless’, an Argentinean variety; accessions 16H1 and 17H2 corresponded to a product of crossing ‘País’ and ‘Muscat of Alexandria’; and, finally, accession 20S5 was identified as ‘Ahmeur bou Ahmeur’, an Algerian genotype harboring pink berries. Two seeded genotypes harboring small and large white berries were not identified as known varieties. The possible use of these accessions for breeding to enhance survival in the harsh environment of the Atacama Desert is discussed.Las accesiones de vid (Vitis vinifera L. de antigua data son una fuente de

  18. Spatial characterization of land surface energy fluxes and uncertainty estimation at the Salar de Atacama, Northern Chile

    Science.gov (United States)

    Kampf, Stephanie K.; Tyler, Scott W.

    2006-02-01

    We use Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) data to estimate spatial energy flux and evaporation distributions at the Salar de Atacama, a playa in Northern Chile. Our approach incorporates ASTER surface kinetic temperature, emissivity, and reflectance data, ground-based meteorological measurements, and empirical parameters. Energy flux distributions are estimated using either spatially constant or spatially distributed values of model parameters, with spatially distributed parameters assigned separately to each land cover category in an image classification. We test the sensitivity of energy budget calculations to state variable and parameter values by conducting Monte Carlo simulations for regions with ground energy budget measurements. Results show that assigning spatially distributed model parameters via land cover classifications yields significant improvements to ground and sensible heat flux predictions. Latent heat fluxes cannot, however, be predicted with sufficient accuracy to allow estimation of area-integrated evaporative moisture loss at this low-evaporation playa.

  19. Issues of affinity: exploring population structure in the Middle and Regional Developments Periods of San Pedro de Atacama, Chile.

    Science.gov (United States)

    Torres-Rouff, Christina; Knudson, Kelly J; Hubbe, Mark

    2013-11-01

    The Middle Period (AD 400-1000) in northern Chile's Atacama oases is characterized by an increase in social complexity and regional interaction, much of which was organized around the power and impact of the Tiwanaku polity. Despite the strong cultural influence of Tiwanaku and numerous other groups evident in interactions with Atacameños, the role of immigration into the oases during this period is unclear. While archaeological and bioarchaeological research in the region has shown no evidence that clearly indicates large groups of foreign immigrants, the contemporary increase in interregional exchange networks connecting the oases to other parts of the Andes suggests residential mobility and the possibility that movement of people both into and out of the oases accompanied these foreign influences. Here, we analyze biodistance through cranial non-metric traits in a skeletal sample from prehistoric San Pedro de Atacama to elucidate the extent of foreign influence in the oases and discuss its implications. We analyzed 715 individuals from the Middle Period (AD 400-1000) and later Regional Developments Period (AD 1000-1450), and found greater phenotypic differences between Middle Period cemeteries than among cemeteries in the subsequent period. We argue that this greater diversity extends beyond the relationship between the oases and the renowned Tiwanaku polity and reflects the role of the oases and its different ayllus as a node and way station for the Middle Period's myriad interregional networks. PMID:24104607

  20. NUEVO REGISTRO DE CHINCHILLA CHINCHILLA (RODENTIA, CHINCHILLIDAE) PARA LA REGIÓN DE ATACAMA, CHILE. IMPLICANCIAS PARA SU ESTADO DE CONSERVACIÓN

    OpenAIRE

    Pablo Valladares F.; Martín Espinosa; Mauricio Torres; Eric Diaz; Nicolai Zeller; Jorge de La Riva; Moisés Grimberg; Ángel Spotorno

    2012-01-01

    Reportamos un nuevo registro de Chinchilla chinchilla para la Región de Atacama, Chile. Se basa en ejemplares fotografiados por cámaras de movimiento en el Parque Nacional Nevado Tres Cruces y sus alrededores y por restos óseos y de fecas encontrados en laderas de cerros, ya sea con pendiente abrupta o con rodados, ambas formaciones con cuevas de mediano tamaño. No existen reportes científicos para esta especie en la Región de Atacama en los últimos cincuenta años. Se analiza el estado de con...

  1. Late Cenozoic geomorphologic signal of Andean forearc deformation and tilting associated with the uplift and climate changes of the Southern Atacama Desert (26 degrees S-28 degrees S)

    OpenAIRE

    Riquelme, R.; Hérail, Gérard; Martinod, J.; Charrier, R.; Darrozes, J

    2007-01-01

    We analyze remarkable examples of the large (similar to 10,000 km(2)) and local-scale (similar to 100 km(2)) landscape forms related to Late Cenozoic geomorphologic evolution of the Andean forearc region in the Southern Atacama Desert. We also consider the continental sedimentary deposits, so-called "Atacama Gravels", which are related to the degradation of the landscape during the Neogene. Our analysis integrates 1:50,000 field cartography, Landsat TM images observations, similar to 1:1000 s...

  2. Interactions between basement and cover during the evolution of the Salar de Atacama Basin, northern Chile

    OpenAIRE

    Nelson Muñoz; Reynaldo Charrier; Teresa Jordan

    2002-01-01

    ABSTRACT A reinterpretation of the structural style on the eastern Cordillera Domeyko and the adjacent Salar de Atacama Basin reveals the existence of west-dipping, high-angle, thrust-faults extending below the Cordillera Domeyko and Cordón de Lila, resulting from inversion of Cretaceous extensional faults, that transferred west-ward their displacement into the cover, generating fault-propagation and detachment folds. The most conspicuous of these structures is the Cordillera de la Sal. Contr...

  3. The Atacama Large Millimeter/submillimeter Array: Overview & status

    OpenAIRE

    Beasley, A. J.; Murowinski, R.; Tarenghi, M.

    2006-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA will be situated on a high-altitude site at 5000 m elevation which provides excellent atmospheric transmission over the instrument wavelength range of 0.3 to 3 mm. ALMA will be comprised of two key observing components: an array of up to sixty-four 12-m diameter antennas arranged in a multiple configurations ranging in size from 0.15 to ~...

  4. Characterization of land surface energy fluxes at the Salar de Atacama, Northern Chile using ASTER image classification

    Science.gov (United States)

    Kampf, S. K.; Tyler, S. W.

    2003-12-01

    Models of land surface energy fluxes often use remotely sensed data to derive surface temperature, albedo, and emissivity, important parameters in energy budget calculations. The ability to determine the spatial distribution of these parameters can lead to improved estimations of the spatial variability of land surface energy fluxes. However, other parameters used in energy flux calculations such as aerodynamic resistance are not directly linked to quantities commonly derived from remotely sensed data. If images can be accurately classified into separate land cover types, empirically determined values of unknown parameters can then be assigned separately to each land cover classification. This study examines several techniques of determining the spatial distribution of land surface energy fluxes at the Salar de Atacama, a large playa in northern Chile. Fluxes are calculated using Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) Level 2 surface kinetic temperature, surface emissivity, and surface reflectance data in conjunction with ground-based meteorological measurements. Energy fluxes are calculated initially by applying a single value of aerodynamic resistance to the entire image area. Subsequently, the ASTER scene is classified into distinct land cover types, and land surface roughness is characterized using the ratio of ASTER band 3N (nadir-viewing) to band 3B (back-viewing). Separate values of aerodynamic resistance are then assigned to each land cover type, and energy fluxes over the entire Salar de Atacama are calculated using these spatially distributed aerodynamic resistance values. Results of both energy flux calculation techniques are evaluated at several sites on the playa using ground-based energy flux measurements.

  5. UV-resistant yeasts isolated from a high-altitude volcanic area on the Atacama Desert as eukaryotic models for astrobiology

    OpenAIRE

    Pulschen, André A; Rodrigues, Fabio; Duarte, Rubens T D; Araujo, Gabriel G; Santiago, Iara F; Paulino-Lima, Ivan G.; Carlos A Rosa; Massuo J. Kato; Pellizari, Vivian H.; Galante, Douglas

    2015-01-01

    The Sairecabur volcano (5971 m), in the Atacama Desert, is a high-altitude extreme environment with high daily temperature variations, acidic soils, intense UV radiation, and low availability of water. Four different species of yeasts were isolated from this region using oligotrophic media, identified and characterized for their tolerance to extreme conditions. rRNA sequencing revealed high identity (>98%) to Cryptococcus friedmannii, Exophiala sp., Holtermanniella watticus, and Rhodosporidiu...

  6. The Miniaturized Raman System and Detection of Traces of Life in Halite from the Atacama Desert: Some Considerations for the Search for Life Signatures on Mars

    OpenAIRE

    Vítek, Petr; Jehlicka, J.; H. G. M. Edwards; Hutchinson, Ian; Ascaso, Carmen; Wierzchos, Jacek

    2012-01-01

    Raman spectroscopy is being adopted as a nondestructive instrumentation for the robotic exploration of Mars to search for traces of life in the geological record. Here, miniaturized Raman spectrometers of two different types equipped with 532 and 785 nm lasers for excitation, respectively, were compared for the detection of microbial biomarkers in natural halite from the hyperarid region of the Atacama Desert. Measurements were performed directly on the rock as well as on the homogenized, pow...

  7. Cenozoic subsurface stratigraphy and structure of the Salar de Atacama Basin, northern Chile

    Science.gov (United States)

    Jordan, T. E.; Mpodozis, C.; Muñoz, N.; Blanco, N.; Pananont, P.; Gardeweg, M.

    2007-02-01

    Sequence mapping of industry seismic lines and their correlation to exposed stratigraphic formations enable a description of the evolution of the nonmarine Salar de Atacama Basin. This major tectonic basin, located in the present-day forearc of the northern Chilean Andes, was first defined topographically by late Cretaceous inversion of the Jurassic-early Cretaceous extensional Tarapacá backarc Basin. Inversion led to both the uplift of the Cordillera de Domeyko and subsidence of the Salar de Atacama Basin along its eastern flank. The basin evolved from a continental backarc in the Cretaceous and Paleogene to a forearc tectonic setting during the Neogene. The principal causes of basin-scale tectonic subsidence include late Cretaceous and earliest Paleocene shortening and Oligocene-early Miocene localized extension. The basin was not completely filled by late Cretaceous (Purilactis Group, sequence G) and Paleocene (sequence H) strata, and its empty space persisted through the Cenozoic. Eocene deformation caused long-wavelength rotation of a deeply weathered surface, generating an erosional unconformity across which coarse clastic strata accumulated (sequence J). Oligocene-early Miocene normal faulting, perhaps in a transtensional environment, repositioned the western basin margin and localized hangingwall subsidence, leading to the accumulation of thousands of meters of evaporitic strata (sequence K, Paciencia Group). By the close of the early Miocene, shortening resumed, first uplifting the intrabasinal Cordillera de la Sal and later generating Pliocene blind reverse faults within the topographically lowest part of the basin. Unequal deposition and tilting across the nascent Cordillera de la Sal induced diapirism of the Paciencia Group halite. In combination, inherited accommodation space and new tectonic subsidence, plus local salt-withdrawal subsidence, shaped the distribution of Upper Miocene-Recent ignimbrites, evaporites, and clastics (sequence M and Vilama

  8. Interpersonal violence in prehistoric San Pedro de Atacama, Chile: behavioral implications of environmental stress.

    Science.gov (United States)

    Torres-Rouff, Christina; Costa Junqueira, María Antonietta

    2006-05-01

    The prehistoric population of San Pedro de Atacama lived through periods marked by prosperity and interregional interaction, as well as times of severe drought, social stress, and widespread poverty. A sample of 682 crania was analyzed for evidence of cranial trauma in order to assess changing patterns of interpersonal violence during the occupation of the oasis. It was hypothesized that the level of traumatic injuries in this population would parallel some of the changes seen in the archaeological record. Low fracture rates would be expected in periods of affluence and environmental stability, while periods characterized by environmental extremes and state collapse would yield elevated rates of aggression. This analysis found that rates of trauma escalated from 5.1% (5/99) in the earliest period, to 10.9% (10/92) in the Middle Horizon (AD 600-950). Although it may reflect problems related to increasing population density in the oasis, this increase is surprising, given that the early period witnessed the shift to permanent settlements, and the middle period was one of prosperity and plentiful resource availability. Trauma rates peaked at 35.6% (16/45) in an early Late Intermediate period (AD 950-1400) cemetery, with other Late Intermediate cemeteries demonstrating similarly high rates of traumatic injury. The elevated trauma rates during this period correlate with major droughts, the concentration of settlements on the oasis' east side, fortified structures, and material poverty, all reflected in the archaeological record. As the Late Intermediate waned and environmental conditions improved, trauma concomitantly decreased (7.0%), and remained low throughout the Inka occupation (AD 1400-1532). This indicates that while the Atacama was not peaceful, violence became commonplace only during periods of great social change and resource stress. PMID:16353221

  9. Early performance of Olea europaea cv. Arbequina, Picual and Frantoio in the southern Atacama Desert

    Directory of Open Access Journals (Sweden)

    Freddy Mora

    2008-01-01

    Full Text Available The cultivars Arbequina, Picual and Frantoio of Olea europaea are cultivated in severalMediterranean countries. In 1999, these cultivars were planted at three locations in the region of Coquimbo,an arid, Mediterranean-like area in Chile. A generalized linear modeling approach was used in view of thenon-normal distribution of the agronomic data sets. Fruit yield (harvests of 2002-2003, precocity (2002 andtree survival (after four growing seasons differed significantly between the cultivars. Arbequina and Picualhad a positive effect on the yield. Picual was the earliest cultivar at two sites. The survival rate of Frantoio washigh at the three sites (90-100%, as opposed to Picual (56-83%. The approach of Generalized Linear Modelswas particularly useful where the assumption of normality was not satisfied. The selection of cultivars ispromising in this arid region of Chile, while the success will depend on the selection of well-adapted genotypesto a particular location.

  10. Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea.

    Science.gov (United States)

    Pyenson, Nicholas D; Gutstein, Carolina S; Parham, James F; Le Roux, Jacobus P; Chavarría, Catalina Carreño; Little, Holly; Metallo, Adam; Rossi, Vincent; Valenzuela-Toro, Ana M; Velez-Juarbe, Jorge; Santelli, Cara M; Rogers, David Rubilar; Cozzuol, Mario A; Suárez, Mario E

    2014-04-22

    Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities. PMID:24573855

  11. Ground-based millimeter-wave observation of stratospheric ClO over Atacama, Chile in the midlatitude Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    T. Kuwahara

    2012-02-01

    Full Text Available We have performed ground-based measurements of stratospheric chlorine monoxide (ClO during the summer in 2009 over the Atacama highland, Chile, a new observing site in the mid-latitude region in the Southern Hemisphere by using a millimeter-wave spectroscopic radiometer. The radiometer equipped with a superconducting receiver and a digital Fourier spectrometer is developed by Nagoya University, and the new system provides us high sensitivity and stable performance to measure the very weak ClO lines. The receiver noise temperature of the superconducting receiver is 170 K in DSB. To reveal the diurnal variation of ClO, we retrieved the vertical mixing ratio profiles by the weighted-damped least squares algorithm applied for the spectral data at 203 GHz obtained between 5 and 16 December 2009. The total error on the retrieval is estimated to be 20% to 30% in an altitude range from 40 to 50 km. The amplitude of the diurnal variation is ±33, ±33, and ±36% at 40, 45, and 50 km, respectively. The time variation curve is basically similar to the previous diurnal variation observed in the northern mid-latitude region but there is a tendency that the increasing rate after the sunrise becomes smaller as the altitude increases.

  12. Paleoenvironmental records from newly recovered sediment cores at the southeast margin of the Salar de Atacama, Chile

    Science.gov (United States)

    Boutt, D. F.; Munk, L. A.; Hynek, S. A.; Corenthal, L.; Huff, H. A.

    2014-12-01

    A suite of new cores recovered from recent boreholes in the southeastern margin of the Salar de Atacama, Chile span a modern environmental gradient from distal alluvial fans, groundwater discharge marshes, sulfate-rich playas, saline lagoons, and the halite nucleus of the salar. These same environments are preserved as stratigraphic records of environmental change in the cores. Cores from the salar nucleus are dominated by halite, and similarly alluvial cores provide a poor paleoenvironmental record. However, the cores from the transition zone between the salar margin and the halite nucleus document alluvial, lagoonal, and evaporite environments. Cores near the halite nucleus record inter-bedded carbonate, gypsum, and halite. Finely laminated carbonates inter-bedded with cm-thick halite beds are a target for U-series geochronology. Cores near modern lagoons contain 2-6 m thick diatomites in addition to microbially-mediated carbonate, organic-rich mud, and minor alluvium. The uppermost 20 cm of diatomite deposits are commonly rooted with vascular plant material which is being processed for 14C geochronology. Ignimbrite and tephra deposits are also encountered and will provide important chronological control. The presence and absence of the 3.5-4.0 Ma Tucucaro ignimbrite in various cores documents a complex pattern of subsidence near the salar margin, some areas have accumulated little sediment since its deposition while in other areas the cores likely record only late Pleistocene deposition. Preliminary interpretations of the stratigraphic records within a paleohydrologic context are tenable. The specific control on this paleohydrologic record is likely to be a combination of increased inflow due to wetter climates and migration of the freshwater/brine interface which underlies the margins of the Salar de Atacama. Stratigraphic variations in the lithium content of evaporite minerals is being explored as a potential indicator of water balance. Lithium concentrations

  13. INDIGENOUS MOBILIZATIONS AND ENVIRONMENTAL PROTESTS IN THE SALAR DE ATACAMA (NORTHERN CHILE)

    OpenAIRE

    Paola Bolados García; Guillaume Boccara

    2015-01-01

    Después del retorno a la democracia en Chile -a fines del siglo pasado-, se inicia un proceso de reconocimiento formal de los pueblos originarios a través de una política indígena y multicultural. No obstante, esta coincidió con el avance y la consolidación del modelo neoliberal impuesto durante el régimen militar a mediados de la década de 1970, el cual continuó privatizando recursos naturales concentrados en territorios indígenas. En este trabajo mostramos como este neoliberalismo multicult...

  14. Solving the Mystery of the Atacama Nitrate Deposits: The Use of Stable Oxygen Isotope Analysis and Geochemistry

    OpenAIRE

    Ji-Hye Seo

    2011-01-01

    The Atacama Desert, Chile, one of the oldest and driest deserts on Earth, is unique because it contains the largest known nitrate deposits in the world. The origin of these nitrate deposits has been a mystery since their discovery in the 1800s. There are two possible sources of natural nitrate: microbiological processes and photochemical reactions. The majority of material on Earth follows mass-dependent fractionation between stable oxygen isotopes with the abundance of 17Ο (denoted by δ) as ...

  15. INDIGENOUS MOBILIZATIONS AND ENVIRONMENTAL PROTESTS IN THE SALAR DE ATACAMA (NORTHERN CHILE

    Directory of Open Access Journals (Sweden)

    Paola Bolados García

    2015-06-01

    Full Text Available Después del retorno a la democracia en Chile -a fines del siglo pasado-, se inicia un proceso de reconocimiento formal de los pueblos originarios a través de una política indígena y multicultural. No obstante, esta coincidió con el avance y la consolidación del modelo neoliberal impuesto durante el régimen militar a mediados de la década de 1970, el cual continuó privatizando recursos naturales concentrados en territorios indígenas. En este trabajo mostramos como este neoliberalismo multicultural desplegado en un contexto de nuevas privatizaciones, fue contestado y resistido por las poblaciones indígenas atacameñas en el norte de Chile a mediados de la primera década del nuevo siglo, poniendo en crisis las relaciones con el estado y las empresas -principalmente mineras y turísticas-, presentes en su territorio. Nos centramos en las luchas emprendidas por las comunidades atacameñas a mediados del 2000 y sus intentos por recuperar los recursos naturales y culturales mercantilizados bajo un discurso de derechos indígenas y ambientales propagado por los gobiernos socialistas de Ricardo Lagos (2000-2006 y Michelle Bachelet (2006-2010.

  16. The Atacama Large Millimeter/submillimeter Array

    CERN Document Server

    Wootten, Alwyn

    2009-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA is situated on a dry site at 5000 m elevation, allowing excellent atmospheric transmission over the instrument wavelength range of 0.3 to 10 mm. ALMA will consist of two arrays of high-precision antennas. One, of up to 64 12-m diameter antennas, is reconfigurable in multiple patterns ranging in size from 150 meters up to ~15 km. A second array is comprised of a set of four 12-m and twelve 7-m antennas operating in one of two closely packed configurations ~50 m in diameter. The instrument will provide both interferometric and total-power astronomical information on atomic, molecular and ionized gas and dust in the solar system, our Galaxy, and the nearby to high-redshift universe. In this paper we outline the scientific drivers, technical challenges and planned progress of ALMA.

  17. Soil Formation and Transport Processes on Hillslopes along a Precipitation Gradient in the Atacama Desert, Chile

    OpenAIRE

    Owen, Justine J.

    2009-01-01

    The climate-dependency of the rates and types of soil formation processes on level landforms has been recognized and documented for decades. In contrast, methods for quantifying rates of soil formation and transport on hillslopes have only recently been developed and the results suggest that these rates are independent of climate. One explanation for this discrepancy is that hillslopes and their soil mantles are dynamic systems affected by local and regional tectonic effects. Tectonics can ch...

  18. Isotope hydrology investigation, area of the Salar de Llamara, Atacama Desert, Chile

    International Nuclear Information System (INIS)

    Different applications of environmental isotopes (18O and 2H) in relation with the hydrogeology of a Northern Chilean basin are presented. The investigation was centered specially in the isotopic characterization of springs and rivers, evaporation processes in river, the generation of the floods, infiltration processes in the alluvium fans, and the origin and movement of the groundwater. (author). 5 refs, 12 figs

  19. Arsenic resistant bacteria isolated from arsenic contaminated river in the Atacama Desert (Chile).

    Science.gov (United States)

    Escalante, G; Campos, V L; Valenzuela, C; Yañez, J; Zaror, C; Mondaca, M A

    2009-11-01

    In this study, arsenic resistant bacteria were isolated from sediments of an arsenic contaminated river. Arsenic tolerance of bacteria isolated was carried out by serial dilution on agar plate. Redox abilities were investigated using KMnO4. arsC and aox genes were detected by PCR and RT-PCR, respectively. Bacterial populations were identified by RapID system. Forty nine bacterial strains were isolated, of these, 55 % corresponded to the reducing bacteria, 4% to oxidizing bacteria, 8% presented both activities and in 33% of the bacteria none activity was detected. arsC gene was detected in 11 strains and aox genes were not detected. The activity of arsenic transforming microorganisms in river sediment has significant implications for the behavior of the metalloid. PMID:19779656

  20. Upper crustal fault reactivation and the potential of triggered earthquakes on the Atacama Fault System, N-Chile

    Science.gov (United States)

    Victor, Pia; Ewiak, Oktawian; Thomas, Ziegenhagen; Monika, Sobiesiak; Bernd, Schurr; Gabriel, Gonzalez; Onno, Oncken

    2016-04-01

    The Atacama Fault System (AFS) is an active trench-parallel fault system, located in the forearc of N-Chile directly above the subduction zone interface. Due to its well-exposed position in the hyper arid forearc of N-Chile it is the perfect target to investigate the interaction between the deformation cycle in the overriding forearc and the subduction zone seismic cycle of the underlying megathrust. Although the AFS and large parts of the upper crust are devoid of any noteworthy seismicity, at least three M=7 earthquakes in the past 10 ky have been documented in the paleoseismological record, demonstrating the potential of large events in the future. We apply a two-fold approach to explore fault activation and reactivation patterns through time and to investigate the triggering potential of upper crustal faults. 1) A new methodology using high-resolution topographic data allows us to investigate the number of past earthquakes for any given segment of the fault system as well as the amount of vertical displacement of the last increment. This provides us with a detailed dataset of past earthquake rupture of upper plate faults which is potentially linked to large subduction zone earthquakes. 2) The IPOC Creepmeter array (http://www.ipoc-network.org/index.php/observatory/creepmeter.html) provides us with high-resolution time series of fault displacement accumulation for 11 stations along the 4 most active branches of the AFS. This array monitors the displacement across the fault with 2 samples/min with a resolution of 1μm. Collocated seismometers record the seismicity at two of the creepmeters, whereas the regional seismicity is provided by the IPOC Seismological Networks. Continuous time series of the creepmeter stations since 2009 show that the shallow segments of the fault do not creep permanently. Instead the accumulation of permanent deformation occurs by triggered slip caused by local or remote earthquakes. The 2014 Mw=8.2 Pisagua Earthquake, located close to

  1. Geyser eruption intervals and interactions: Examples from El Tatio, Atacama, Chile

    Science.gov (United States)

    Munoz-Saez, Carolina; Namiki, Atsuko; Manga, Michael

    2015-11-01

    We compare and contrast data collected in 2012 and 2014 from the El Tatio geyser field, Chile. We identify geyser systems that evolve over time, including changes in the interval between eruptions, development of new thermal features, and interactions between geysers. We study three different cases: (a) an isolated geyser, which is periodic and has nearly identical eruptions every cycle; (b) a geyser and coupled noneruptive pool, where the geyser has nonregular cycles and several preplay eruptions before the main eruption; and (c) two geysers and a mud volcano, which have nonregular cycles and are all interacting. Though geysers erupt with different styles, we recognize some common features: the conduit recharges with liquid during the quiescent period, bubbles enter the conduit before eruptions, and eruptions occur when water boils in the upper part of the conduit. The episodic addition of heat may govern the periodicity, while the depth where heat is added dictates the eruption style: conduits with deeper heat input are more likely to show preplay or minor eruptions. The interactions between thermal features can be explained by pressure transmission in subsurface permeable layers between geyser conduits.

  2. Critical pathways of change in fruit export regions at desert margin (Chile)

    DEFF Research Database (Denmark)

    Frederiksen, Peter

    The purpose is to elucidate how critical pathways function in a fruit export region at the desert margin in Chile. The region was investigated at the system level as an open land system with managed fruit plantations in a geographically complex valley. Data collection procedures included total...... field surveys, semi-structured interviews, and library investigations. The main result is that no single variable could explain the pathways. Pathways were found to be explained by the functioning of the regional dynamic system. Pathways were found to vary in type, cause, relation and space-time. Global...

  3. Egg laying site selection by a host plant specialist leaf miner moth at two intra-plant levels in the northern Chilean Atacama Desert

    Directory of Open Access Journals (Sweden)

    José Storey-Palma

    2014-09-01

    Full Text Available Egg laying site selection by a host plant specialist leaf miner moth at two intra-plant levels in the northern Chilean Atacama Desert. The spatial distribution of the immature stages of the leaf miner Angelabella tecomae Vargas & Parra, 2005 was determined at two intra-plant levels (shoot and leaflet on the shrub Tecoma fulva fulva (Cav. D. Don (Bignoniaceae in the Azapa valley, northern Chilean Atacama Desert. An aggregated spatial pattern was detected for all the immature stages along the shoot, with an age dependent relative position: eggs and first instar larvae were clumped at apex; second, third and fourth instar larvae were mostly found at intermediate positions; meanwhile the spinning larva and pupa were clumped at basis. This pattern suggests that the females select new, actively growing leaflets for egg laying. At the leaflet level, the immature stages were found more frequently at underside. Furthermore, survivorship was higher for larvae from underside mines. All these results highlight the importance of an accurate selection of egg laying site in the life history of this highly specialized leaf miner. By contrast, eventual wrong choices in the egg laying site selection may be associated with diminished larval survivorship. The importance of the continuous availability of new plant tissue in this highly human modified arid environment is discussed in relation with the observed patterns.

  4. UV-resistant yeasts isolated from a high-altitude volcanic area on the Atacama Desert as eukaryotic models for astrobiology.

    Science.gov (United States)

    Pulschen, André A; Rodrigues, Fabio; Duarte, Rubens T D; Araujo, Gabriel G; Santiago, Iara F; Paulino-Lima, Ivan G; Rosa, Carlos A; Kato, Massuo J; Pellizari, Vivian H; Galante, Douglas

    2015-08-01

    The Sairecabur volcano (5971 m), in the Atacama Desert, is a high-altitude extreme environment with high daily temperature variations, acidic soils, intense UV radiation, and low availability of water. Four different species of yeasts were isolated from this region using oligotrophic media, identified and characterized for their tolerance to extreme conditions. rRNA sequencing revealed high identity (>98%) to Cryptococcus friedmannii, Exophiala sp., Holtermanniella watticus, and Rhodosporidium toruloides. To our knowledge, this is the first report of these yeasts in the Atacama Desert. All isolates showed high resistance to UV-C, UV-B and environmental-UV radiation, capacity to grow at moderate saline media (0.75-2.25 mol/L NaCl) and at moderate to cold temperatures, being C. friedmannii and H. watticus able to grow in temperatures down to -6.5°C. The presence of pigments, analyzed by Raman spectroscopy, correlated with UV resistance in some cases, but there is evidence that, on the natural environment, other molecular mechanisms may be as important as pigmentation, which has implications for the search of spectroscopic biosignatures on planetary surfaces. Due to the extreme tolerances of the isolated yeasts, these organisms represent interesting eukaryotic models for astrobiological purposes. PMID:26147800

  5. Microbial colonization of Ca-sulfate crusts in the hyperarid core of the Atacama Desert: implications for the search for life on Mars.

    Science.gov (United States)

    Wierzchos, J; Cámara, B; de Los Ríos, A; Davila, A F; Sánchez Almazo, I M; Artieda, O; Wierzchos, K; Gómez-Silva, B; McKay, C; Ascaso, C

    2011-01-01

    The scarcity of liquid water in the hyperarid core of the Atacama Desert makes this region one of the most challenging environments for life on Earth. The low numbers of microbial cells in the soils suggest that within the Atacama Desert lies the dry limit for life on our planet. Here, we show that the Ca-sulfate crusts of this hyperarid core are the habitats of lithobiontic micro-organisms. This microporous, translucent substrate is colonized by epilithic lichens, as well as endolithic free-living algae, fungal hyphae, cyanobacteria and non photosynthetic bacteria. We also report a novel type of endolithic community, "hypoendoliths", colonizing the undermost layer of the crusts. The colonization of gypsum crusts within the hyperarid core appears to be controlled by the moisture regime. Our data shows that the threshold for colonization is crossed within the dry core, with abundant colonization in gypsum crusts at one study site, while crusts at a drier site are virtually devoid of life. We show that the cumulative time in 1 year of relative humidity (RH) above 60% is the best parameter to explain the difference in colonization between both sites. This is supported by controlled humidity experiments, where we show that colonies of endolithic cyanobacteria in the Ca-sulfate crust undergo imbibition process at RH >60%. Assuming that life once arose on Mars, it is conceivable that Martian micro-organisms sought refuge in similar isolated evaporite microenvironments during their last struggle for life as their planet turned arid. PMID:20726901

  6. Chile.

    Science.gov (United States)

    1988-09-01

    Chile is a long (2650 miles), narrow (250 miles at widest point) country sandwiched between the Andes mountains and the Pacific. The northern desert is rich in copper and nitrates; the temperate middle region is agricultural and supports the major cities, including Santiago, the capital, and the port of Valparaiso; and the southern region is a cold and damp area of forests, grasslands, lakes, and fjords. The country is divided into 12 administrative regions. Chile's population of 12.5 million are mainly of Spanish or Indian descent or mestizos. Literacy is 92.3%, and the national language is Spanish. Infant mortality is 18.1/1000, and life expectancy is 68.2 years. 82% of the people are urban, and most are Roman Catholics. Chile was settled by the Spanish in 1541 and attached to the Viceroyalty of Peru. Independence was won in 1818 under the leadership of Bernardo O'Higgins. In the 1880s Chile extended its sovereignty over the Strait of Magellan in the south and areas of southern Peru and Bolivia in the north. An officially parliamentary government, elected by universal suffrage, drifted into oligarchy and finally into a military dictatorship under Carlos Ibanez in 1924. Constitutional government was restored in 1932. The Christian Democratic government of Eduardo Frei (1964-70) inaugurated major reforms, including land redistribution, education, and far-reaching social and economic policies. A Marxist government under Salvador Allende lasted from 1970 to 1973 when the present military government of General Pinochet Ugarte took power, overthrew Allende, abolished the Congress, and banned political parties. It has moved the country in the direction of a free market economy but at the cost of systematic violations of human rights. A new constitution was promulgated in 1981, and congressional elections have been scheduled for October, 1989. A "National Accord for Transition to Full Democracy" was mediated by the Catholic Church in 1985. The social reforms of the

  7. Microbial diversity and the presence of algae in halite endolithic communities are correlated to atmospheric moisture in the hyper-arid zone of the Atacama Desert.

    Science.gov (United States)

    Robinson, Courtney K; Wierzchos, Jacek; Black, Celeste; Crits-Christoph, Alexander; Ma, Bing; Ravel, Jacques; Ascaso, Carmen; Artieda, Octavio; Valea, Sergio; Roldán, Mònica; Gómez-Silva, Benito; DiRuggiero, Jocelyne

    2015-02-01

    The Atacama Desert is one of the oldest and driest deserts in the world, and its hyper-arid core is described as 'the most barren region imaginable'. We used a combination of high-throughput sequencing and microscopy methods to characterize the endolithic microbial assemblages of halite pinnacles (salt rocks) collected in several hyper-arid areas of the desert. We found communities dominated by archaea that relied on a single phylotype of Halothece cyanobacteria for primary production. A few other phylotypes of salt-adapted bacteria and archaea, including Salinibacter, Halorhabdus, and Halococcus were major components of the halite communities, indicating specific adaptations to the unique halite environments. Multivariate statistical analyses of diversity metrics clearly separated the halite communities from that of the surrounding soil in the Yungay area. These analyses also revealed distribution patterns of halite communities correlated with atmospheric moisture. Microbial endolithic communities from halites exposed to coastal fogs and high relative humidity were more diverse; their archaeal and bacterial assemblages were accompanied by a novel algae related to oceanic picoplankton of the Mamiellales. In contrast, we did not find any algae in the Yungay pinnacles, suggesting that the environmental conditions in this habitat might be too extreme for eukaryotic photosynthetic life. PMID:24372972

  8. Biogeographic diversification in Nolana (Solanaceae), a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

    Institute of Scientific and Technical Information of China (English)

    Michael O. DILLON; Tieyao TU; Lei XIE; Victor QUIPUSCOA SILVESTRE; Jun WEN

    2009-01-01

    The present paper reconstructs the biogeographic diversification for Nolana L.f. (Solanaceae), a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete "islands" unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.

  9. Modestobacter caceresii sp. nov., novel actinobacteria with an insight into their adaptive mechanisms for survival in extreme hyper-arid Atacama Desert soils.

    Science.gov (United States)

    Busarakam, Kanungnid; Bull, Alan T; Trujillo, Martha E; Riesco, Raul; Sangal, Vartul; van Wezel, Gilles P; Goodfellow, Michael

    2016-06-01

    A polyphasic study was designed to determine the taxonomic provenance of three Modestobacter strains isolated from an extreme hyper-arid Atacama Desert soil. The strains, isolates KNN 45-1a, KNN 45-2b(T) and KNN 45-3b, were shown to have chemotaxonomic and morphological properties in line with their classification in the genus Modestobacter. The isolates had identical 16S rRNA gene sequences and formed a branch in the Modestobacter gene tree that was most closely related to the type strain of Modestobacter marinus (99.6% similarity). All three isolates were distinguished readily from Modestobacter type strains by a broad range of phenotypic properties, by qualitative and quantitative differences in fatty acid profiles and by BOX fingerprint patterns. The whole genome sequence of isolate KNN 45-2b(T) showed 89.3% average nucleotide identity, 90.1% (SD: 10.97%) average amino acid identity and a digital DNA-DNA hybridization value of 42.4±3.1 against the genome sequence of M. marinus DSM 45201(T), values consistent with its assignment to a separate species. On the basis of all of these data, it is proposed that the isolates be assigned to the genus Modestobacter as Modestobacter caceresii sp. nov. with isolate KNN 45-2b(T) (CECT 9023(T)=DSM 101691(T)) as the type strain. Analysis of the whole-genome sequence of M. caceresii KNN 45-2b(T), with 4683 open reading frames and a genome size of ∽4.96Mb, revealed the presence of genes and gene-clusters that encode for properties relevant to its adaptability to harsh environmental conditions prevalent in extreme hyper arid Atacama Desert soils. PMID:27108251

  10. The secret formula of Coke. In Peru and Chile, mining companies may help the solar industry achieve a breakthrough; Das Geheimrezept von Coca-Cola. In Peru und Chile koennten ausgerechnet Bergbaukonzerne der Solarbranche zum Durchbruch verhelfen

    Energy Technology Data Exchange (ETDEWEB)

    Rosell, Alejandro Diego; Siemer, Jochen

    2012-01-15

    Peru and Chile are among the countries with the highest insolation values of the world, but there are hardly any photovoltaic systems. This may change soon; for power supply to mining operations in the Atacama desert, solar power can compete directly with fossil energy sources. Opinions differ, however, as to whether competition can start in the near future or at once.

  11. Object-based analysis of 8-bands Worldview2 imagery for assessing health condition of desert trees

    NARCIS (Netherlands)

    Chávez Oyanadel, R.O.; Clevers, J.G.P.W.

    2012-01-01

    High spatial resolution panchromatic and multispectral WorldView2 images were used to assess the health condition of Tamarugo (Prosopis tamarugo Phil.) trees in the hyperarid Atacama desert in Northern Chile. Tamarugo is a very valuable species for biodiversity conservation due to its endemic charac

  12. Late Mesozoic to Paleogene stratigraphy of the Salar de Atacama Basin, Antofagasta, Northern Chile: Implications for the tectonic evolution of the Central Andes

    Science.gov (United States)

    Mpodozis, Constantino; Arriagada, César; Basso, Matilde; Roperch, Pierrick; Cobbold, Peter; Reich, Martin

    2005-04-01

    The Salar de Atacama basin, the largest "pre-Andean" basin in Northern Chile, was formed in the early Late Cretaceous as a consequence of the tectonic closure and inversion of the Jurassic-Early Cretaceous Tarapacá back arc basin. Inversion led to uplift of the Cordillera de Domeyko (CD), a thick-skinned basement range bounded by a system of reverse faults and blind thrusts with alternating vergence along strike. The almost 6000-m-thick, upper Cretaceous to lower Paleocene sequences (Purilactis Group) infilling the Salar de Atacama basin reflects rapid local subsidence to the east of the CD. Its oldest outcropping unit (Tonel Formation) comprises more than 1000 m of continental red sandstones and evaporites, which began to accumulate as syntectonic growth strata during the initial stages of CD uplift. Tonel strata are capped by almost 3000 m of sandstones and conglomerates of western provenance, representing the sedimentary response to renewed pulses of tectonic shortening, which were deposited in alluvial fan, fluvial and eolian settings together with minor lacustrine mudstone (Purilactis Formation). These are covered by 500 m of coarse, proximal alluvial fan conglomerates (Barros Arana Formation). The top of the Purilactis Group consists of Maastrichtian-Danian alkaline lava and minor welded tuffs and red beds (Cerro Totola Formation: 70-64 Ma K/Ar) deposited during an interval of tectonic quiescence when the El Molino-Yacoraite Late Cretaceous sea covered large tracts of the nearby Altiplano-Puna domain. Limestones interbedded with the Totola volcanics indicate that this marine incursion advanced westwards to reach the eastern CD slope. CD shortening in the Late Cretaceous was accompanied by volcanism and continental sedimentation in fault bounded basins associated to strike slip along the north Chilean magmatic arc to the west of the CD domain, indicating that oblique plate convergence prevailed during the Late Cretaceous. Oblique convergence seems to have

  13. Evaluation of the hydrogeological interconnection between the Salar de Maricunga and the Piedra Pomez basins, Atacama Region, Chile; An isotope and geochemical approach

    International Nuclear Information System (INIS)

    Groundwater is the main water source for the mining industry in the Altiplano of northern Chile. Groundwater also plays a significant role as a water source for lagoons, wetlands and salares, which are important ecosystems for animal life and vegetation communities that exist in this arid region. The rational use and protection of the groundwater resource requires a good understanding of the aquifer systems. One of the key components in the assessment of water resources in Northern Chile, is the hydrogeological interconnection between basins. During the last three years, as part of a major hydrogeological project, Sernageomin has been working in the Altiplano of the Atacama region (Iriarte et al., 1998; Iriarte, 1999; Venegas et al., 2000; Santibanez, in prep.). This study included the evaluation of the geometry and groundwater potential of the aquifers and the chemical characterization of the surface and groundwater. Part of this study has focused on the Salar de Maricunga and the Campo de Piedra Pomez basins, due to an increasing demand for groundwater resources in this area by the mining industry. This paper discusses the use of isotope and geochemical tools that were used to evaluate the hydrogeological interconnection between the Salar de Maricunga and the Piedra Pomez basins. The geological and hydrogeological framework of this work is discussed in detail by Iriarte (1999) (au)

  14. A new species of Ornithodoros (Acari: Argasidae) from desert areas of northern Chile.

    Science.gov (United States)

    Muñoz-Leal, Sebastián; Venzal, José M; González-Acuña, Daniel; Nava, Santiago; Lopes, Marcos G; Martins, Thiago F; Figueroa, Cecilia; Fernández, Nicolás; Labruna, Marcelo B

    2016-07-01

    Ornithodoros atacamensis n. sp. is described from larvae collected on the lizard Liolaemus bisignatus and from free-living adults collected in desert areas from the Pan de Azúcar and Llanos de Challe National Parks, in Northern Chile. Additionally, unengorged larvae were obtained from fertilized females, which laid eggs in the laboratory. Morphological and mitochondrial 16S rDNA sequence analyses were performed in order to compare this new soft tick species with other congeneric Neotropical representatives. Larvae of O. atacamensis are morphologically closely related to Ornithodoros talaje sensu stricto, Ornithodoros puertoricensis, Ornithodoros rioplatensis, Ornithodoros guaporensis and Ornithodoros hasei, all belonging to the O. talaje species group. The larval diagnostic characters for this species are a combination of a large pyriform dorsal plate with a length of approximately 300μm, 17 pairs of dorsal setae with five central pairs, hypostome with apex pointed and dental formula 2/2 in most rows, 3/3 apically, and capsule of the Haller's organ oval in shape without reticulations. Phylogenetic analyses inferred from the mitochondrial 16S rRNA gene and a Principal Component Analysis based on morphometric characters provide additional support to the description of O. atacamensis as an independent lineage within the genus clustering within the O. talaje species group. PMID:27132517

  15. A Microbial Oasis in the Hypersaline Atacama Subsurface Discovered by a Life Detector Chip: Implications for the Search for Life on Mars

    OpenAIRE

    Parro, Victor; de Diego-Castilla, Graciela; Moreno-Paz, Mercedes; Blanco, Yolanda; Cruz-Gil, Patricia; Rodríguez-Manfredi, José A.; Fernández-Remolar, David; Gómez, Felipe; Manuel J. Gómez; Luis A Rivas; Demergasso, Cecilia; Echeverría, Alex; Urtuvia, Viviana N.; Ruiz-Bermejo, Marta; García-Villadangos, Miriam

    2011-01-01

    The Atacama Desert has long been considered a good Mars analogue for testing instrumentation for planetary exploration, but very few data (if any) have been reported about the geomicrobiology of its salt-rich subsurface. We performed a Mars analogue drilling campaign next to the Salar Grande (Atacama, Chile) in July 2009, and several cores and powder samples from up to 5 m deep were analyzed in situ with LDChip300 (a Life Detector Chip containing 300 antibodies). Here, we show the discovery o...

  16. Ground-based millimeter-wave observation of stratospheric ClO over Atacama, Chile in the mid-latitude Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    T. Kuwahara

    2012-11-01

    Full Text Available We have performed ground-based measurements of stratospheric chlorine monoxide (ClO during the summer in 2009 over the Atacama highland, Chile, a new observing site in the mid-latitude region in the Southern Hemisphere, by using a millimeter-wave spectroscopic radiometer. The radiometer, equipped with a superconducting receiver and a digital Fourier spectrometer, was developed by Nagoya University, and the new observing system provides us high sensitivity and stable performance to measure the very weak ClO lines. The receiver noise temperature of the superconducting receiver is 170 K in DSB. To reveal the diurnal variation of ClO, we retrieved the vertical mixing ratio profiles by the weighted-damped least-squares algorithm applied for the spectral data at 203 GHz obtained between 5 and 16 December 2009. The total error on the retrieval is estimated to be 20% to 30% in an altitude range from 40 km to 50 km. The amplitude of the diurnal variation is estimated as 33% of the daytime average at 40 km. The observed time variation shows a pattern similar to that of the previous works observed in the northern mid-latitude region.

  17. Antifungal activity of extracts from Atacama Desert fungi againstParacoccidioides brasiliensis and identification ofAspergillus felis as a promising source of natural bioactive compounds

    Directory of Open Access Journals (Sweden)

    Graziele Mendes

    2016-03-01

    Full Text Available Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5 of the extracts showed minimum inhibitory concentration (MIC values≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero. This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

  18. Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds.

    Science.gov (United States)

    Mendes, Graziele; Gonçalves, Vívian N; Souza-Fagundes, Elaine M; Kohlhoff, Markus; Rosa, Carlos A; Zani, Carlos L; Cota, Betania B; Rosa, Luiz H; Johann, Susana

    2016-03-01

    Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity. PMID:27008375

  19. María Elena: el fin de una experiencia urbana: Un estudio de caso en el desierto de Atacama, Chile

    Directory of Open Access Journals (Sweden)

    JUAN CARLOS RODRÍGUEZ TORRENT

    2009-08-01

    Full Text Available En el presente trabajo se plantea la relación entre la ciudad salitrera de María Elena (II Región, diseñada de acuerdo a propuestas utópicas en un territorio privado, y el cambio de las relaciones laborales entre la Compañía SQM y los trabajadores a partir del predominio de un nuevo modelo de acumulación cuyos ejes están dados por la competitividad, la producción de calidad y la globalización. La ciudad fue creada para que hombres y mujeres construyeran sus proyectos de vida en medio del Desierto de Atacama, ofreciéndoles todas las garantías y la infraestructura para que ello fuese así en los marcos de una política de pleno empleo, de modo de contener a la población en un medio inhóspito, cumplir los objetivos productivos y fortalecer una identidad coherente y cohesionada, lo que a partir de nuevas decisiones estratégicas es substituido por un modelo de flexibilidad laboral, lo que anula su definición primigenia y el interés colectivo para comenzar a dar paso a un campamento minero.In this paper we look into the relationship between the nitrate town of Maria Elena (in Region II - designed on Utopian principals as a private project - and the changing labor relations between the SQM Company and the workers as a result of the predominance of a new accumulation model guided by competitiveness, quality production and globalization. The town was created so that men and women could establish their livelihoods in the Atacama Desert, with guarantees and infrastructure based on a full employment policy. This was in order to anchor the population in this inhospitable environment, to meet production objectives and to strengthen a coherent and cohesive identity. New strategic decisions led to this model being replaced by one based on labour flexibilization, deleting its original intention and collective interest to give way to a mining camp.

  20. Investigating multiple fault rupture at the Salar del Carmen segment of the Atacama Fault System (northern Chile): Fault scarp morphology and knickpoint analysis

    Science.gov (United States)

    Ewiak, Oktawian; Victor, Pia; Oncken, Onno

    2015-02-01

    This study presents a new geomorphological approach to investigate the past activity and potential seismic hazard of upper crustal faults at the Salar del Carmen segment of the Atacama Fault System in the northern Chile forearc. Our contribution is based on the analysis of a large set of topographic profiles and allows extrapolating fault analysis from a few selected locations to distances of kilometers along strike of the fault. We detected subtle changes in the fault scarp geometry which may represent the number of paleoearthquakes experienced by the structure and extracted the cumulative and last incremental displacement along strike of the investigated scarps. We also tested the potential of knickpoints in channels crossing the fault scarps as markers for repeated fault rupture and proxies for seismic displacement. The number of paleoearthquakes derived from our analysis is 2-3, well in agreement with recent paleoseismological investigations, which suggest 2-3 earthquakes (Mw = 6.5-6.7) at the studied segments. Knickpoints record the number of events for about 55% of the analyzed profile pairs. Only few knickpoints represent the full seismic displacement, while most retain only a fraction of the displacement. The along-strike displacement distributions suggest fault growth from the center toward the tips and linkage of individual ruptures. Our approach also improves the estimation of paleomagnitudes in case of multiple fault rupture by allowing to quantify the last increment of displacement separately. Paleomagnitudes calculated from total segment length and the last increment of displacement (Mw = 6.5-7.1) are in agreement with paleoseismological results.

  1. Fast Detection of Phenolic Compounds in Extracts of Easter Pears (Pyrus communis) from the Atacama Desert by Ultrahigh-Performance Liquid Chromatography and Mass Spectrometry (UHPLC–Q/Orbitrap/MS/MS)

    OpenAIRE

    Simirgiotis, Mario J.; Cristina Quispe; Jorge Bórquez; Carlos Areche; Beatriz Sepúlveda

    2016-01-01

    A small Chilean variety of pears growing in the town of Toconao, an oasis located at the northeastern edge of the Salar de Atacama, northern Chile, was studied by means of modern PDA and high resolution mass spectral data (UHPLC-PDA-HESI-orbitrap-MS/MS). In addition, the antioxidant features of the fruits were compared with the varieties Packhman’s Triumph and Abate Fetel and correlated with the presence of phenolic compounds. The non-pigmented phenolics were fingerprinted and related to the ...

  2. Phylogeny of Nolana (Solanaceae) of the Atacama and Peruvian deserts inferred from sequences of four plastid markers and the nuclear LEAFY second intron.

    Science.gov (United States)

    Tu, Tieyao; Dillon, Michael O; Sun, Hang; Wen, Jun

    2008-11-01

    The phylogeny of Nolana (Solanaceae), a genus primarily distributed in the coastal Atacama and Peruvian deserts with a few species in the Andes and one species endemic to the Galápagos Islands, was reconstructed using sequences of four plastid regions (ndhF, psbA-trnH, rps16-trnK and trnC-psbM) and the nuclear LEAFY second intron. The monophyly of Nolana was strongly supported by all molecular data. The LEAFY data suggested that the Chilean species, including Nolana sessiliflora, the N. acuminata group and at least some members of the Alona group, are basally diverged, supporting the Chilean origin of the genus. Three well-supported clades in the LEAFY tree were corroborated by the SINE (short interspersed elements) or SINE-like insertions. Taxa from Peru are grouped roughly into two clades. Nolana galapagensis from the Galápagos Island is most likely to have derived from a Peruvian ancestor. The monophyly of the morphologically well-diagnosed Nolana acuminata group (N. acuminata, N. baccata, N. paradoxa, N. parviflora, N. pterocarpa, N. rupicola and N. elegans) was supported by both plastid and LEAFY data. Incongruence between the plastid and the LEAFY data was detected concerning primarily the positions of N. sessiliflora, N. galapagensis, taxa of the Alona group and the two Peruvian clades. Such incongruence may be due to reticulate evolution or in some cases lineage sorting of plastid DNA. Incongruence between our previous GBSSI trees and the plastid-LEAFY trees was also detected concerning two well-supported major clades in the GBSSI tree. Duplication of the GBSSI gene may have contributed to this incongruence. PMID:18722540

  3. Habitar el desierto: Transición Energética y Transformación del Proyecto Habitacional Colectivo en la Ecología del desierto de Atacama, Chile.

    OpenAIRE

    Guerra Ramírez, José Norberto

    2003-01-01

    DE TESIS DOCTORALEsta investigación, surge por la necesidad de incluir los sistemas de acondicionamiento ambiental natural y el diseño energético pasivo en el proyecto arquitectónico en la ecología del desierto de Atacama, Chile. Por ello, la finalidad es describir y desvelar las causas de la involución del proceso de transición energética y de transformación ambiental realizada por los usuarios de las viviendas del conjunto habitacional Salar del Carmen; ubicado en la ciudad de Antofagasta. ...

  4. Peces Chimaeriformes (Chondrichthyes, Holocephali del Neógeno de la Formación Bahía Inglesa (Región de Atacama, Chile Chimaeroid fishes (Chondrichthyes, Holocephali from the Neogene of Bahía Inglesa Formation (Atacama, Chile

    Directory of Open Access Journals (Sweden)

    Mario E. Suárez

    2004-07-01

    Full Text Available Se describen los primeros restos fósiles de peces condrictios holocéfalos para el Neógeno de la Formación Bahía Inglesa, Atacama, Chile. El material comprende una placa dental palatina y un mandibular que fueron recolectados al sureste de Caldera desde niveles fosilíferos asignados al Mioceno Medio-Mioceno tardío. Rasgos morfológicos característicos y comparaciones con otras placas de quimeras callorrínquidas, actuales y fósiles, permiten designar el material como Callorhinchus sp.The first record of Neogene holocephalan chondrichthyans fishes from the Bahía Inglesa Formation is documented. The new material is Middle Miocene-Late Miocene in age and comprises two dental plates coming from fossiliferous beds located to the southeast of southern Caldera. Based on its characteristic features and comparison with living and other fossil callorhynchids the plates are assigned to Callorhinchus sp.

  5. Spectroscopic Results from the Life in the Atacama (LITA) Project 2004 Field Season

    Science.gov (United States)

    Piatek, J. L.; Moersch, J. E.; Wyatt, M.; Rampey, M.; Cabrol, N. A.; Wettergreen, D. S.; Whittaker, R.; Grin, E. A.; Diaz, G. Chong

    2005-01-01

    Introduction: The Life in the Atacama (LITA) project includes rover field tests designed to look for life in the arid environment of the Atacama Desert (Chile). Field instruments were chosen to help remote observers identify potential habitats and the presence of life in these habitats, and included two spectrometers for help in identifying the mineralogy of the field sites. Two field trials were undertaken during the 2004 field season. The remote science team had no prior knowledge of the local geology, and relied entirely on orbital images and rover-acquired data to make interpretations. Each field trial lasted approximately one week: the sites for these trials were in different locations, and are designated "Site B" and "Site C."

  6. Nuevos datos cinemáticos para la Falla Sierra Castillo en Quebrada del Carrizo, Precordillera de la Región de Atacama, Chile

    Directory of Open Access Journals (Sweden)

    Hans Niemeyer

    1999-12-01

    Full Text Available Se estudió la Falla Sierra Castillo y sus estructuras mesoscópicas conexas en Quebrada del Carrizo y sus alrededores, donde al este yuxtapone terrenos triásicos y paleozoicos, con terrenos bajocianos al oeste. en dicha falla juega el papel de falla maestra respecto de sus estructuras conexas. Se infiere que sus movimientos eoceno-oligocenos estuvieron dominados por 'stresses' transpresivos con transcurrencia sinistral. Esta inferencia surge del estudio de estructuras S-C en rocas de falla, y en la vergencia de un pliegue de arrastre, directamente observados sobre la traza de la falla. Sus estructuras conexas son compatibles con dicho sentido de movimiento y están formadas por fallas inversas, pliegues ptigmáticos, grietas de tensión, clivaje; además de vetas y fallas subverticales en posición T (tensión y R (Riedel. Se determinaron las direcciones y sentidos del transporte tectónico sobre la base de la cinemática de fallas inversas y la intersección de éstas con el clivaje. Se deduce una rotación de 65° en el sentido horario de la dirección de acortamiento, desde un rumbo oeste hasta uno nor-noroeste. Por otro lado, se consideró la alternativa que las rocas hayan rotado en sentido antihorario, conservándose constante la dirección de acortamientoNew kinematic data from the Sierra Castillo Fault at Quebrada del Carrizo, Precordillera of Atacama Region, Chile. The Sierra Castillo Fault and its associated mesoscopic structures were studied at Quebrada del Carrizo. Here the fault juxtaposes Triassic and Paleozoic rocks on the east with Bajocian rocks on the west. The Sierra Castillo Fault serves as a master fault of its associated mesoscopic structures. It is inferred that a sinistral traspression occurred along it during the Eocene-Oligocene. This inference is based on S-C structures and a drag fold directly observed on the trace of the fault. This deduction is also based on other associated structures such as reverse faults

  7. Monitoring seismic and silent faulting along the Atacama Fault System and its relation to the subduction zone seismic cycle: A Creepmeter Study in N-CHile

    Science.gov (United States)

    Victor, Pia; Ziegenhagen, Thomas; Bach, Christoph; Walter, Thomas; Oncken, Onno

    2010-05-01

    The relationship between crustal forearc faults and subduction zone processes is little understood and therefore the modern seismogenic capacity of these faults cannot be determined. The Atacama Fault System (AFS) is the dominant trench parallel fault in N-Chile with an along strike extent of 1000km. In order to characterize the mode of deformation accumulation and its spatio-temporal distribution, we are continuously monitoring displacement accumulation along active fault branches with a recently installed Creepmeter array. All the installed Creepmeters use 12 mm thick Invar-rod as length standard buried up to 0.7 m depth to reduce the signal to noise ratio, and measure the length standard change across a fault on outcrop scale. The currently deployed 9 sites are designed for displacement detection in the range of 0.001 - 50 mm/yr with a sampling rate of 1/min. The monitored fault branches have been chosen such that 3 Creepmeter sites are located in the Iquique seismic gap of the subduction zone, 5 instruments are located in the segment that recently ruptured in the 2007 Tocopilla earthquake, whereof 2 are located on the Mejillones Peninsula and one is located in the Antofagasta segment that last ruptured in the 1995 Antofagasta Earthquake. This enables us to compare the mode of strain accumulation in different stages of the subduction zone seismic cycle. The first datasets (> 1 yr) show that the instruments both in the Antofagasta and Tocopilla segments display a continuous creep signal equivalent to extensional displacement across the fault zone superimposed by sudden displacement events related to subduction zone earthquakes. The sum of both amounts to 0.02 mm/y - 0.1 mm/y of displacement which is less than predicted by the geological long-term observation. The data from the Chomache Fault located in the Iquique segment shows only a creep signal for the first year after installation with an average extensional displacement rate of 0.05 mm/y. No sudden

  8. The contribution of remotely triggered displacement events to the long-term strain accumulation along the Atacama Fault System, N-Chile

    Science.gov (United States)

    Victor, P.; Schurr, B.; Sobiesiak, M.; Ewiak, O.; Oncken, O.

    2012-12-01

    The Atacama Fault System (AFS) in N-Chile is an active trench-parallel fault system, located above approximately the down-dip end of coupling of the north Chilean subduction zone. The average long-term displacement rate for the last 100 000 - 10 000 years ranges between 0.2 and 0.3 mm/yr as determined by various methods and authors. The mode of displacement accumulation through time for this type of fault is not well understood. Surface ruptures along individual segments of the main fault scarp unambiguously reveal that the AFS has seismically ruptured several times during its past, but recurrence intervals are at least one order of magnitude longer than the megathrust earthquake cycle of the underlying subduction interface. Nevertheless these trench parallel fault systems bear a potential of unexpected large seismic ruptures as demonstrated by prominent examples like the Kobe Earthquak in 1995 and Denali Earthquake in 2002. The aim of this study is to quantify the relative proportion of aseismic and seismic slip through time and to investigate the impact of subduction zone earthquakes on the slip behavior of the AFS. Since 2008 we continuously monitor four active fault segments of the AFS with an array of 11 creepmeter stations, two of them co-located with Broadband seismometers. The displacement across the fault is continuously monitored with 2 samples/min with a resolution of 1μm. The displacement time series reveals that no continuous creep can be detected for 10 of the 11 stations. Instead we observe sudden displacement events correlated in time with far field megathrust earthquakes or local earthquakes on the plate interface or in the overriding crust. The most prominent event recorded on the creepmeters was the Mw=8.8 Maule earthquake in 2010 located 1500km to 1800km away from the creepmeter array. All of the stations showed a triggered sudden displacement event 6-8 min after the main shock. Correlation with seismological data from a nearby IPOC station

  9. Water Relations and Foliar Isotopic Composition of Prosopis tamarugo Phil., an Endemic Tree of the Atacama Desert Growing at Three Levels of Water Table Depth.

    Science.gov (United States)

    Garrido, Marco; Silva, Paola; Acevedo, Edmundo

    2016-01-01

    Prosopis tamarugo Phil. is a strict phreatophyte tree species endemic to the "Pampa del Tamarugal", Atacama Desert. The extraction of water for various uses has increased the depth of the water table in the Pampa aquifers threatening its conservation. This study aimed to determine the effect of the groundwater table depth on the water relations of P. tamarugo and to present thresholds of groundwater depth (GWD) that can be used in the groundwater management of the P. tamarugo ecosystem. Three levels of GWD, 11.2 ± 0.3 m, 10.3 ± 0.3 m, and 7.1 ± 0.1 m, (the last GWD being our reference) were selected and groups of four individuals per GWD were studied in the months of January and July of the years 2011 through 2014. When the water table depth exceeded 10 m, P. tamarugo had lower pre-dawn and mid-day water potential but no differences were observed in minimum leaf stomatal resistance when compared to the condition of 7.1 m GWD; the leaf tissue increased its δ(13)C and δ(18)O composition. Furthermore, a smaller green canopy fraction of the trees and increased foliage loss in winter with increasing water table depth was observed. The differences observed in the physiological behavior of P. tamarugo trees, attributable to the ground water depth; show that increasing the depth of the water table from 7 to 11 m significantly affects the water status of P. tamarugo. The results indicate that P. tamarugo has an anisohydric stomatal behavior and that given a reduction in water supply it regulates the water demand via foliage loss. The growth and leaf physiological activities are highly sensitive to GWD. The foliage loss appears to prevent the trees from reaching water potentials leading to complete loss of hydraulic functionality by cavitation. The balance achieved between water supply and demand was reflected in the low variation of the water potential and of the variables related to gas exchange over time for a given GWD. This acclimation capacity of P. tamarugo after

  10. Thermal and Evolved Gas Analysis (TEGA) of hyperarid soils doped with microorganisms from the Atacama Desert in southern Peru (Pampas de la Joya): Implications for the Phoenix Mission

    Science.gov (United States)

    Valdivia-Silva, Julio E.; Navarro-Gonzalez, Rafael; McKay, Chris

    less arid soils. Organic C in the form of CO2 (ion 44 m/z) for microorganisms evolved between 326±19.5° C showing characteristic patterns for each one. Others ions such as 41, 78 and 91 m/z were found too. Interestingly, the release of CO2 increased and ions previously found disappeared, demonstrating a high-oxidant activity in the soil matrix when it is subjected to temperature. Samples of soil pre-treated show CO2 evolved up to 650° C suggesting thermal decomposition of carbonates. Finally in hyperarid soils, ion 44 began its release to 330±30° C while the less arid soils to 245±45° C. These results indicate that some organics (mixed with soils) are oxidized to CO2, and that carbonates present in hyperarid soils also decompose into CO2. The nature of oxidant(s) present in the soils from Pampas de La Joya is still unknown. Key words: Thermal analysis, TEGA, Atacama desert, La Joya desert, hyperarid soils.

  11. First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae in the coastal valleys of northern Chile

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2014-03-01

    Full Text Available First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae in the coastal valleys of northern Chile. The trees Haplorhus peruviana Engl. and Schinus molle L. (Anacardiaceae are mentioned as the first host plant records for the little known native moth Iridopsis hausmanni Vargas, 2007 (Lepidoptera, Geometridae, Ennominae in the coastal valleys of the northern Chilean Atacama Desert. This is also the first record of Anacardiaceae as host plant for a Neotropical species of Iridopsis Warren, 1894.

  12. First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae) in the coastal valleys of northern Chile

    OpenAIRE

    2014-01-01

    First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae) in the coastal valleys of northern Chile. The trees Haplorhus peruviana Engl. and Schinus molle L. (Anacardiaceae) are mentioned as the first host plant records for the little known native moth Iridopsis hausmanni Vargas, 2007 (Lepidoptera, Geometridae, Ennominae) in the coastal valleys of the northern Chilean Atacama Desert. This is also the first record of Anacardiaceae as host plant for a Neotropical species...

  13. Chile.

    Science.gov (United States)

    1992-05-01

    The background notes on Chile provide a statistical summary of the population, geography, government, and the economy, and more descriptive text on the history, population, government, economy, defense, and foreign relations. In brief, Chile has 13.3 million Spanish Indian (Mestizos), European, and Indian inhabitants and an annual growth rate of 1.6%. 96% are literate. Infant mortality is 18/1000. 34% of the population are involved in industry and commerce, 30% in services, 19% in agriculture and forestry and fishing, 7% in construction, and 2% in mining. The major city is Santiago. The government, which gained independence in 1810, is a republic with executive, legislative, and judicial branches. There are 12 regions. There are 6 major political parties. Suffrage is universal at 18 years. Gross domestic product (GDP) is $29.2 billion. The annual growth rate is 5% and inflation is 19%. Copper, timber, fish, iron ore, nitrates, precious metals, and molybdenum are its natural resources. Agricultural products are 9% of GDP and include wheat, potatoes, corn, sugar beets, onions, beans, fruits, and livestock. Industry is 21% of GDP and includes mineral refining, metal manufacturing, food and fish processing, paper and wood products, and finished textiles. $8.3 billion is the value of exports and $7 billion of imports. Export markets are in Japan, the US, Germany, Brazil, and the United Kingdom. Chile received $3.5 billion in economic aid between 1949-85, but little in recent years. 83% live in urban centers, principally around Santiago. Congressional representation is made on the basis of elections by a unique binomial majority system. Principal government officials are identified. Chile has a diversified free market economy and is almost self-sufficient in food production. The US is a primary trading partner. 49% of Chile's exports are minerals. Chile maintains diplomatic relations with 70 countries, however, relations are strained with Argentina and Bolivia. Relations

  14. Atacama perchlorate as an agricultural contaminant in groundwater: Isotopic and chronologic evidence from Long Island, New York

    Science.gov (United States)

    Böhlke, J.K.; Hatzinger, P.B.; Sturchio, N.C.; Gu, B.; Abbene, I.; Mroczkowski, S.J.

    2009-01-01

    Perchlorate (ClO4-) is a common groundwater constituent with both synthetic and natural sources. A potentially important source of ClO4- is past agricultural application of ClO4--bearing natural NO3- fertilizer imported from the Atacama Desert, Chile, but evidence for this hasbeenlargely circumstantial. Here we report ClO4- stable isotope data (??37Cl, ??18O, and ??17O), along with other supporting chemical and isotopic environmental tracer data, to document groundwater ClO4- contamination sources and history in parts of Long Island, New York. Sampled groundwaters were oxic and ClO4- apparently was not affected by biodegradation within the aquifers. Synthetic ClO4- was indicated by the isotopic method in groundwater near a fireworks disposal site at a former missile base. Atacama ClO4- was indicated in agricultural and urbanizing areas in groundwaters with apparent ages >20 years. In an agricultural area, ClO4- concentrations and ClO4-/NO3- ratios increased withgroundwaterage, possiblybecauseof decreasing application rates of Atacama NO3- fertilizers and/or decreasing ClO4- concentrations in Atacama NO 3- fertilizers in recent years. Because ClO 4-/NO3- ratios of Atacama NO 3- fertilizers imported in the past (???2 ?? 10-3 mol mol-1) were much higher than the ClO 4-/NO3- ratio of recommended drinking-water limits (7 ?? 10-5 mol mol-1 in New York), ClO4- could exceed drinkingwater limits even where NO3- does not, and where Atacama NO3- was only a minor source of N. Groundwater ClO4- with distinctive isotopic composition was a sensitive indicator of past Atacama NO3- fertilizer use on Long Island and may be common in other areas that received NO3- fertilizers from the late 19th century through the 20th century. ?? 2009 American Chemical Society.

  15. El Qhapaqñan entre Atacama y Lípez The Qhapaqñan between Atacama and Lípez

    Directory of Open Access Journals (Sweden)

    Axel E. Nielsen

    2006-12-01

    Full Text Available Este trabajo describe tramos de dos ramales del Qhapaqñan que comunican el desierto de Atacama (Región de Antofagasta, Chile con el Altiplano de Lípez (Departamento Potosí, Bolivia. El primero de ellos, que se extiende entre Licancabur y Laguna Chojllas, formaba parte de una vía que vinculaba el nodo inkaico de San Pedro de Atacama con los valles chichas y la Puna argentina. El segundo ingresa a Bolivia por el Portezuelo del Inca procedente de la cuenca del río Salado y se dirige directamente hacia la zona de Chiguana-Colcha K, que parece haber operado como eje del dominio Inka sobre el Altiplano de Lípez. Partiendo de estos datos, se discuten aspectos relacionados con la circulación de bienes, el aprovisionamiento de los contingentes en tránsito y las prácticas rituales asociadas a los pasos montañosos que atraviesa el camino.This paper describes segments of two branches of the Inka road that communicate the Atacama Desert (Antofagasta Region, Chile and the Lípez Altiplano (Department of Potosi, Bolivia. The first, which extends between Licancabur and Laguna Chojllas, was part of a road that connected the Inka node of San Pedro de Atacama with the Chicha Valleys and the Argentine Puna. The second enters Bolivia through Portezuelo del Inca, coming from the Salado River basin, and heads directly toward Chiguana-Colcha K, an area that apparently served as the axis of Inka rule in the Lipez Altiplano. On the basis of these data, we discuss issues related to the circulation of goods, the supply of groups using the tampu system, and the ritual practices associated with the mountain passes along the road.

  16. Chile.

    Science.gov (United States)

    1986-04-01

    In 1985, Chile's population stood at 12 million, with an annual growth rate of 1.7%. 1984's infant mortality rate was 20/1000 live births and life expectancy was 67 years. The literacy rate was 94%. Of the work force of 3,841,000 in 1985, 15.9% were engaged in agriculture, forestry, and fishing; 31.3% were employed in industry and commerce; 38.6% were in the service sector; 8.7% worked in mining; and 4.4% were employed in construction. Chile's military junta is scheduled to be replaced by an elected legislature in 1990. The GDP was US $19.2 billion in 1984, with an annual real growth rate of 6.3%, and per capita GDP stood at US$1590. Inflation averages 23%. Industry comprises 21% of the GDP. Longterm prospects for the Chilean economy are influenced by a high debt service ratio, very low domestic savings and investment, the prospect of little or no increase in copper prices, and continuing problems in the domestic financial sector. In 1985-88, under the International Monetary Fund macroeconomic program, Chile will strive for moderate economic growth while managing its external debt servicing burden. PMID:12178144

  17. La desregulación de las cooperativas eléctricas no concesionarias en chile: san pedro de atacama como paradigma de referencia

    OpenAIRE

    Ascencio Otárola, Marco Felipe

    2016-01-01

    Este trabajo afrontará el contexto general del sistema eléctrico y su incidencia en casos excepcionales, particularmente con empresas no concesionaras de distribución, poniendo énfasis en un caso referencial de carácter rural, la Cooperativa Eléctrica de San Pedro de Atacama y su desenvolvimiento normativo y fáctico frente a la desregulación

  18. Simultaneous seeing measurements at Atacama

    Science.gov (United States)

    Uraguchi, Fumihiro; Motohara, Kentaro; Doi, Mamoru; Takato, Naruhisa; Miyashita, Akihiko; Tanabe, Toshihiko; Oyabu, Shinki; Soyano, Takao

    2004-10-01

    Institute of Astronomy, University of Tokyo is now planning to build a 6.5-m optical-infrared telescope in Atacama, Chile. This project is called "Univ. Tokyo Atacama Observatory (TAO)", and the site evaluation is now under way. As a part of this evaluation process, we started an investigation to compare the astronomical seeing at Atacama with that at Mauna Kea. Here, we report preliminary results of seeing measurements at several sites in Atacama, carried out on October 2003. In order to separate the temporal and site-to-site variation of the seeing, we used two sets of Differential Image Motion Monitors (DIMMs), each of which has two pairs of 7.4 cm sub-apertures with 20.5 cm separation. Three sites were investigated; the point near the TAO weather station (4,950m), the summit of Cello Chico (5,150m) and the point at 5,430m altitude on Cello Toco. Simultaneous measurements were carried out for three half nights out of four half nights measurements. Although the amount of our data is very limited, the results suggest following: 1) Seeing becomes better and more stable as time passing to midnight (eg. From 0."7 to 0."4 at V-band). 2) Higher altitude sites show better seeing than lower altitude sites.

  19. Sources, sinks and long-term cycling of iodine in the hyperarid Atacama continental margin

    Science.gov (United States)

    Álvarez, Fernanda; Reich, Martin; Pérez-Fodich, Alida; Snyder, Glen; Muramatsu, Yasuyuki; Vargas, Gabriel; Fehn, Udo

    2015-07-01

    The Atacama region in northern Chile hosts the driest desert on Earth and is the world's premier iodine production province. The origin of iodine enrichment in Atacama is controversial and fundamentally different processes have been invoked over the years that involve marine, eolian and more recently deep sedimentary fluid and groundwater sources. As a result of the very limited geochemical iodine data in Atacama and the western South American margin, the origin of iodine enrichment in this region still remains elusive. In this study, we present a comprehensive survey of iodine concentrations and isotopic ratios (129I/I) of different reservoirs in the Atacama Desert of northern Chile, including nitrate soils, supergene copper deposits, marine sedimentary rocks, geothermal fluids, groundwater and meteoric water. Nitrate soils along the eastern slope of the Coastal Cordillera are found to have mean iodine concentrations of at least three orders of magnitude higher than the mean crustal abundances of ∼0.12 ppm, with a mean concentration of ∼700 ppm. Soils above giant copper deposits in the Central Depression are also highly enriched in iodine (100's of ppm range), and Cu-iodide and iodate minerals occur in the supergene enrichment zones of some of these deposits. Further east in the Precordillera, Jurassic sedimentary shales and limestones show above-background iodine concentrations, the latter averaging ∼50 ppm in the southern portion of the study area. The highest iodine concentrations in fluids were measured in groundwater below nitrate soils in the Coastal Range (∼3.5-10 ppm) and in geothermal waters (1-3 ppm) along the volcanic arc. Although highly variable, the iodine isotopic ratios (129I/I) of Jurassic marine sedimentary rocks (∼300-600 × 10-15), nitrate soils (∼150-1500 × 10-15) and waters (∼215 × 10-15) are consistently low (factors has played an unforeseen role in transporting and accumulating iodine and other soluble components in the

  20. Source apportionment of PM10 and PM2.5 in a desert region in northern Chile

    International Nuclear Information System (INIS)

    Estimating contributions of anthropogenic sources to ambient particulate matter (PM) in desert regions is a challenging issue because wind erosion contributions are ubiquitous, significant and difficult to quantify by using source-oriented, dispersion models. A receptor modeling analysis has been applied to ambient PM10 and PM2.5 measured in an industrial zone ∼ 20 km SE of Antofagasta (23.63°S, 70.39°W), a midsize coastal city in northern Chile; the monitoring site is within a desert region that extends from northern Chile to southern Perú. Integrated 24-hour ambient samples of PM10 and PM2.5 were taken with Harvard Impactors; samples were analyzed by X Ray Fluorescence, ionic chromatography (NO3− and SO4=), atomic absorption (Na+, K+) and thermal optical transmission for elemental and organic carbon determination. Receptor modeling was carried out using Positive Matrix Factorization (US EPA Version 3.0); sources were identified by looking at specific tracers, tracer ratios, local winds and wind trajectories computed from NOAA's HYSPLIT model. For the PM2.5 fraction, six contributions were found — cement plant, 33.7 ± 1.3%; soil dust, 22.4 ± 1.6%; sulfates, 17.8 ± 1.7%; mineral stockpiles and brine plant, 12.4 ± 1.2%; Antofagasta, 8.5 ± 1.3% and copper smelter, 5.3 ± 0.8%. For the PM10 fraction five sources were identified — cement plant, 38.2 ± 1.5%; soil dust, 31.2 ± 2.3%; mineral stockpiles and brine plant, 12.7 ± 1.7%; copper smelter, 11.5 ± 1.6% and marine aerosol, 6.5 ± 2.4%. Therefore local sources contribute to ambient PM concentrations more than distant sources (Antofagasta, marine aerosol) do. Soil dust is enriched with deposition of marine aerosol and calcium, sulfates and heavy metals from surrounding industrial activities. The mean contribution of suspended soil dust to PM10 is 50 μg/m3 and the peak daily value is 104 μg/m3. For the PM2.5 fraction, suspended soil dust contributes with an average of 9.3 μg/m3 and a peak daily

  1. Fast Detection of Phenolic Compounds in Extracts of Easter Pears (Pyrus communis from the Atacama Desert by Ultrahigh-Performance Liquid Chromatography and Mass Spectrometry (UHPLC–Q/Orbitrap/MS/MS

    Directory of Open Access Journals (Sweden)

    Mario J. Simirgiotis

    2016-01-01

    Full Text Available A small Chilean variety of pears growing in the town of Toconao, an oasis located at the northeastern edge of the Salar de Atacama, northern Chile, was studied by means of modern PDA and high resolution mass spectral data (UHPLC-PDA-HESI-orbitrap-MS/MS. In addition, the antioxidant features of the fruits were compared with the varieties Packhman’s Triumph and Abate Fetel and correlated with the presence of phenolic compounds. The non-pigmented phenolics were fingerprinted and related to the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP, the superoxide anion scavenging activity assay (SA, and total content of phenolics and flavonoids measured by spectroscopic methods. The machine allowed a fast separation of 15 min employing a flow rate of 1 mL per minute and could accurately identify 25 compounds, including several isorhamnetin derivatives and phenolic acids, present in the peel and pulps of this Chilean variety for the first time. The compounds were monitored using a wavelength range of 210–800 nm. The native small Chilean pear showed the highest antioxidant activity measured as the bleaching of the DPPH radical, the ferric reducing antioxidant power and superoxide anion scavenging activity (8.61 ± 0.65 μg/mL, 712.63 ± 12.12 micromols trolox equivalents (μmol/TE/100 g FW, and 82.89% ± 2.52% at 100 μg/mL, respectively.

  2. Fast Detection of Phenolic Compounds in Extracts of Easter Pears (Pyrus communis) from the Atacama Desert by Ultrahigh-Performance Liquid Chromatography and Mass Spectrometry (UHPLC-Q/Orbitrap/MS/MS).

    Science.gov (United States)

    Simirgiotis, Mario J; Quispe, Cristina; Bórquez, Jorge; Areche, Carlos; Sepúlveda, Beatriz

    2016-01-01

    A small Chilean variety of pears growing in the town of Toconao, an oasis located at the northeastern edge of the Salar de Atacama, northern Chile, was studied by means of modern PDA and high resolution mass spectral data (UHPLC-PDA-HESI-orbitrap-MS/MS). In addition, the antioxidant features of the fruits were compared with the varieties Packhman's Triumph and Abate Fetel and correlated with the presence of phenolic compounds. The non-pigmented phenolics were fingerprinted and related to the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics and flavonoids measured by spectroscopic methods. The machine allowed a fast separation of 15 min employing a flow rate of 1 mL per minute and could accurately identify 25 compounds, including several isorhamnetin derivatives and phenolic acids, present in the peel and pulps of this Chilean variety for the first time. The compounds were monitored using a wavelength range of 210-800 nm. The native small Chilean pear showed the highest antioxidant activity measured as the bleaching of the DPPH radical, the ferric reducing antioxidant power and superoxide anion scavenging activity (8.61 ± 0.65 μg/mL, 712.63 ± 12.12 micromols trolox equivalents (μmol/TE)/100 g FW, and 82.89% ± 2.52% at 100 μg/mL, respectively). PMID:26784158

  3. Desert Pathfinder at Work

    Science.gov (United States)

    2005-09-01

    The Atacama Pathfinder Experiment (APEX) project celebrates the inauguration of its outstanding 12-m telescope, located on the 5100m high Chajnantor plateau in the Atacama Desert (Chile). The APEX telescope, designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range, passed successfully its Science Verification phase in July, and since then is performing regular science observations. This new front-line facility provides access to the "Cold Universe" with unprecedented sensitivity and image quality. After months of careful efforts to set up the telescope to work at the best possible technical level, those involved in the project are looking with satisfaction at the fruit of their labour: APEX is not only fully operational, it has already provided important scientific results. "The superb sensitivity of our detectors together with the excellence of the site allow fantastic observations that would not be possible with any other telescope in the world," said Karl Menten, Director of the group for Millimeter and Sub-Millimeter Astronomy at the Max-Planck-Institute for Radio Astronomy (MPIfR) and Principal Investigator of the APEX project. ESO PR Photo 30/05 ESO PR Photo 30/05 Sub-Millimetre Image of a Stellar Cradle [Preview - JPEG: 400 x 627 pix - 200k] [Normal - JPEG: 800 x 1254 pix - 503k] [Full Res - JPEG: 1539 x 2413 pix - 1.3M] Caption: ESO PR Photo 30/05 is an image of the giant molecular cloud G327 taken with APEX. More than 5000 spectra were taken in the J=3-2 line of the carbon monoxide molecule (CO), one of the best tracers of molecular clouds, in which star formation takes place. The bright peak in the north of the cloud is an evolved star forming region, where the gas is heated by a cluster of new stars. The most interesting region in the image is totally inconspicuous in CO: the G327 hot core, as seen in methanol contours. It is a truly exceptional source, and is one of the richest sources of emission from complex organic molecules in the

  4. Climate Change in Deserts and the Role of CO2

    International Nuclear Information System (INIS)

    Impressive climate changes between the glaciers of the Alps and the deserts of the Namib (Namibia), the Atacama (Chile) and the Thar (Pakistan) since the last 500 000 years raise the question whether they have been caused by the up and down of the atmospheric CO2. If so, can the global CO2 policy prevent the inundation of the densely populated coast strips around the world or does it favor the wealth of the rich countries in the middle latitudes penalizing the poor people living in the arid belt. Desert research has answers because these areas react particularly sensitive to climatic changes but suffers from the shortage of material suitable for accurate dating. However, numerical dating is indispensable for a success. The results and consequences of our own research, including also rare but relevant papers of others, will be discussed. (author)

  5. EL IMAGINARIO PEDAGÓGICO EN LAS ESCUELAS SALITRERAS DEL DESIERTO DE ATACAMA

    Directory of Open Access Journals (Sweden)

    JOSÉ ANTONIO GONZÁLEZ

    2011-05-01

    Full Text Available RESUMEN El artículo analiza el funcionamiento del sistema escolar durante el ciclo salitrero en el desierto de Atacama, destacando las escuelas, las bibliotecas, el profesorado, el alumnado y las relaciones entre los normalistas y las empresas salitreras. Palabras claves: Escuelas, Oficinas salitreras, Desierto de Atacama, Antofagasta. ABSTRACT This paper analyzes the school system operation during the nitrate mine cycle in the Atacama Desert, pointing out schools, libraries, teachers, students and relations between primary school teachers and nitrate companies. Key words: Schools, Nitrate mines, Atacama Desert, Antofagasta.

  6. Los componentes de la variación intramuestral en la población prehistórica de San Pedro de Atacama, Chile

    Directory of Open Access Journals (Sweden)

    Varela, Héctor Hugo

    1996-01-01

    Full Text Available Se presenta una síntesis de una serie de experiencias realizadas con el fin de analizar el efecto del dimorfismo sexual, la variación etaria, la deformación artificial y la variación cronológica sobre la morfología craneana de la población prehistórica de San Pedro de Atacama. La muestra está constituída por 120 cráneos de ambos sexos, de edades adulto, maduro y senil, deformados y no deformados artificialmente, pertenecientes a cementerios que cubren cuatro fases culturales del Periodo Agroalfarero (500aC-1500dC. Los ejemplares masculinos presentaron valores medios mayores que los femeninos en la mayoría de las variables analizadas. La influencia de los restantes factores se manifestó en un tercio de las medidas craneométricas. Entre las clases adulto y maduro se comprobó un incremento significativo de los promedios. El efecto de la deformación artificial se destaca principalmente por alteraciones en el crecimiento de la bóveda y, en menor medida, en la cara y en la base del cráneo. Un hallazgo de importancia lo constituye la existencia de variación cronológica indicando cambios en la estructura de la población en el período estudiado.

  7. Dual origins of epigenetic hydrothermal Ba and Pb-Zn deposits in the Chanarcillo group, Atacama Region, Chile: An example in the Quebrada Galena

    International Nuclear Information System (INIS)

    In the Lower Cretaceous Chanarcillo Group, in the Atacama Region, structurally-controlled vein, disseminated and stratiform base metal mineralization is mainly associated with the intrusive and metasomatic activity of the Cretaceous magmatic arc (Chilean Iron Belt). A distinct group of epigenetic base metal stratiform deposits, involving moderate temperature fluids in part associated with hydrocarbons, is best explained by basinal-scale processes (Cisternas et al., 1999; Lieben et al., 1999). In this study, a dual origin, with more or less prominent involvement of Cretaceous magmatism, has been evidenced for carbonate-hosted Pb-Zn±Ag and Ba deposits and occurrences in the Chanarcillo Group. In the Quebrada Galena (28o05'S, 70o30'W) the presence, within a few kilometers, of such different Ba and Pb-Zn ore occurrence types provides an opportunity to study the relative timing and the possible genetic links between the different mineralizing processes. With this purpose, we firstly describe two deposits with the most contrasting characteristics, the Maria Cristina Zn-Pb-(Ba) skarn deposit, and the Mamina stratiform barite deposit. In a second step, Ba and Pb-Zn deposits and occurrences with intermediate characteristics could help to unravel the relations between these oreforming systems. Fluid inclusions microthermometry, and sulfur and strontium isotopes are used to provide further insight into the nature of ore-forming fluids and source of ore-forming elements, and 40Ar/39Ar dating to constrain the age of the Zn-Pb skarn mineralization (au)

  8. A DRONE FLIGHT OVER PARANAL, CHILE

    CERN Document Server

    2016-01-01

    Aerial clip (shot using a drone and a Go pro) describing ESO's astronomical observatory facilities in the Atacama desert, Northern Chile. Locations covered by the drone flight include Cerro Paranal, with the Residencia (external and internal views) and the Very Large Telescope facility on Cerro Paranal, from above and with a peek into Unit Telescope 1 and its 8,2 m diameter mirror; final image on Cerro Armazones, the site chosen for building ESO's next telescope, the E-ELT (European Extremely Large Telescope). With a 39-metre main mirror, it will be the largest optical/near-infrared telescope in the world. The Argentinian Codillera with the Llullaillaco volcano are visible in the background.

  9. Licancabur Volcano, Bolivia and life in the Atacama: Environmental physics and analogies to Mars

    Science.gov (United States)

    Hock, Andrew Nelson

    Although there is no perfect environmental analog to Mars on Earth, quantitative study of relevant terrestrial field sites can serve as the basis for physical models and technology development to aid future exploration. This dissertation describes original field and laboratory research on two terrestrial analog sites: Licancabur Volcano, Bolivia, and the Atacama Desert, Chile. Atop Licancabur, at an elevation of nearly 6,000 meters above sea level, sits the highest volcanic lake on Earth. Prior to this work, little was known about the lake, its waters, the role of volcanism or its potential relationship to locales on Mars. In the first part of this work, I describe observations of the lake resulting from several years of field study, including data on meteorological conditions and solar irradiance. These and other measurements provide the basis for (1) the first quantitative mass and energy balance model of the lake, and (2) the first determination of the altitude effect on solar visible and ultraviolet flux from the high altitude summit. Under the observed conditions, model results indicate: lake waters are primarily meteoric in origin and evaporating rapidly; volcanic input is not required to explain observations of lake water temperature or year-end model results. Nearby, Chile's Atacama Desert is known to be one of the driest, most inhospitable environments on Earth. There, environmental similarities to Mars provide an apt testing ground for new astrobiological exploration technologies. In the latter part of this work, I present results from my work with the Life In The Atacama (LITA) Mars rover field experiment. In particular, I report on the development of a new data analysis tool named the LITA Data Scoring System (DSS). Subject to the user-defined constraints, the DSS was used to facilitate targeting, analysis and mapping of rover science results relevant to potential habitability and evidence for life at three desert field sites. Although experimental in

  10. Chile's energy

    Energy Technology Data Exchange (ETDEWEB)

    1988-11-18

    In recent years, a new emphasis has been placed on increasing solid fuel availability in Chile, to reach the northern mining operations where demand for power is soaring. The south of the country is well served by hydroelectric power plants (2.3 million kW). The coal industry has doubled its capacity to cope with increased copper production - the Tocopilla power plant at the Chuquicamata copper mine has been converted from oil to coal - and there has been a major investment programme in the steel industry. In 1986, 1.4 million tons of coal was mined, mostly from the Provinces of Concepcion and Arauco, the remainder from Valdivia. Since then, 70 million US dollars has been invested by COCAR SA in the Pecket deposit near Punta Arenas. Coal from Pecket should cost around 26 dollars/t compared with 60 dollars/t for underground coal. It should support an expanded coal market in Chile and may also be able to compete in the Brazilian and Argentine markets. Reserves are estimated at over 200 Mt. Petroleum reserves in Tierra del Fuego are nearly exhausted; seismic surveys in the Atacama desert are promising.

  11. Characterization of bacterial diversity associated with microbial mats, gypsum evaporites and carbonate microbialites in thalassic wetlands: Tebenquiche and La Brava, Salar de Atacama, Chile.

    Science.gov (United States)

    Farías, M E; Contreras, M; Rasuk, M C; Kurth, D; Flores, M R; Poiré, D G; Novoa, F; Visscher, P T

    2014-03-01

    In this paper, we report the presence of sedimentary microbial ecosystems in wetlands of the Salar de Atacama. These laminated systems, which bind, trap and precipitate mineral include: microbial mats at Laguna Tebenquiche and Laguna La Brava, gypsum domes at Tebenquiche and carbonate microbialites at La Brava. Microbial diversity and key biogeochemical characteristics of both lakes (La Brava and Tebenquiche) and their various microbial ecosystems (non-lithifying mats, flat and domal microbialites) were determined. The composition and abundance of minerals ranged from trapped and bound halite in organic-rich non-lithifying mats to aragonite-dominated lithified flat microbialites and gypsum in lithified domal structures. Pyrosequencing of the V4 region of the 16s rDNA gene showed that Proteobacteria comprised a major phylum in all of the microbial ecosystems studied, with a marked lower abundance in the non-lithifying mats. A higher proportion of Bacteroidetes was present in Tebenquiche sediments compared to La Brava samples. The concentration of pigments, particularly that of Chlorophyll a, was higher in the Tebenquiche than in La Brava. Pigments typically associated with anoxygenic phototrophic bacteria were present in lower amounts. Organic-rich, non-lithifying microbial mats frequently formed snake-like, bulbous structures due to gas accumulation underneath the mat. We hypothesize that the lithified microbialites might have developed from these snake-like microbial mats following mineral precipitation in the surface layer, producing domes with endoevaporitic communities in Tebenquiche and carbonate platforms in La Brava. Whereas the potential role of microbes in carbonate platforms is well established, the contribution of endoevaporitic microbes to formation of gypsum domes needs further investigation. PMID:24442191

  12. CONCENTRACIÓN DE MINERALES DE TITANIO CONTENIDOS EN LAS ARENAS DE PLAYAS DE LA REGIÓN DE ATACAMA - CHILE

    Directory of Open Access Journals (Sweden)

    Luis Valderrama Campusano

    2008-07-01

    Full Text Available El presente trabajo tiene como fin caracterizar y concentrar minerales de titanio contenidos en las arenas de playas de la Región de Atacama. El análisis mineralógico indicó que los principales constituyentes son cuarzo, feldespato, ilmenita, titanita, rutilo y trazas de circonita, monacita y wolframita. Los análisis químicos indican que la ley de TiO2 es de 2,3% y 3,15% para las arenas de Huasco y Caldera, respectivamente. Al retirar el material sobre 0,300 mm, se produce una preconcentración, aumentando las leyes de TiO2 a 5,33% para Huasco y 6,48% para Caldera. Las pruebas de concentración gravitacional fueron realizadas en una mesa Wilfley, y fueron estudiados diferentes ángulos de inclinación de la mesa, para la concentración primaria (2,5°; 3,0°; 3,5º y 4,0° y la limpieza (5,0°; 5,5; 6,0° y 6,5° respectivamente. Los mejores resultados fueron obtenidos usando un ángulo de inclinación de 3,0° para la concentración primaria y 6,0° para limpiar el concentrado. Con estos resultados se diseñó un circuito para las arenas de Huasco, lográndose un concentrado final con una ley de 46,0% de TiO2 y una recuperación de 21,2%, y para Caldera, se obtuvo un concentrado final de 51,3% TiO2 con una recuperación de 17,4%.

  13. Detectors for the Atacama B-mode Search experiment

    Science.gov (United States)

    Appel, John William

    Inflation is the leading theory for explaining the initial conditions that brought about our homogeneous and isotropic Universe. It predicts the presence of gravitational waves in the early Universe, which implant a characteristic B-mode polarization pattern on the Cosmic Microwave Background (CMB). The Atacama B-mode Search (ABS) experiment is a polarimeter observing from Cerro Toco (located in the Atacama desert of Chile at an altitude of 5190 m), searching for the yet undetected B-mode signal. ABS carries 480 superconducting Transition Edge Sensor (TES) Bolometers that couple 150 GHz radiation via planar Ortho-Mode Transducers (OMTs) mounted at the output of corrugated feedhorns. The feedhorn beam is projected onto the sky through crossed Dragonian reflectors, a set of reflective and absorptive filters, and a rotating Half Wave Plate (HWP) that modulates any polarized sky signal at 10.2 Hz. The bolometers are cooled to 300 mK by a He3-He4 adsorption fridge system backed by pulse tubes. The reflectors are located within the 4 K cavity of the cryostat, while the HWP is mounted on frictionless air bearings above the cryostat window. This thesis discusses the development and construction of the ABS detector focal plane, and presents results of its performance in the field through August 2012. The ABS detector array sensitivity of 31 μKs 1/2, together with the experiment's unique set of systematic controls, and expected multi-year integration time, could detect a B-mode signal with tensor to scalar ratio r ˜ 0.1.

  14. EL IMAGINARIO PEDAGÓGICO EN LAS ESCUELAS SALITRERAS DEL DESIERTO DE ATACAMA

    OpenAIRE

    JOSÉ ANTONIO GONZÁLEZ

    2011-01-01

    RESUMEN El artículo analiza el funcionamiento del sistema escolar durante el ciclo salitrero en el desierto de Atacama, destacando las escuelas, las bibliotecas, el profesorado, el alumnado y las relaciones entre los normalistas y las empresas salitreras. Palabras claves: Escuelas, Oficinas salitreras, Desierto de Atacama, Antofagasta. ABSTRACT This paper analyzes the school system operation during the nitrate mine cycle in the Atacama Desert, pointing out schools, libraries, teachers, studen...

  15. Description of a very dense meteorite collection area in western Atacama: Insight into the long-term composition of the meteorite flux to Earth

    Science.gov (United States)

    Hutzler, Aurore; Gattacceca, JéRôMe; Rochette, Pierre; Braucher, RéGis; Carro, Bertrand; Christensen, Eric J.; Cournede, CéCile; Gounelle, Matthieu; Laridhi Ouazaa, Nejia; Martinez, Rodrigo; Valenzuela, Millarca; Warner, Michael; Bourles, Didier

    2016-03-01

    We describe the geological, morphological, and climatic settings of two new meteorite collections from Atacama (Chile). The "El Médano collection" was recovered by systematic on-foot search in El Médano and Caleta el Cobre dense collection areas and is composed of 213 meteorites before pairing, 142 after pairing. The "private collection" has been recovered by car by three private hunters and consists of 213 meteorites. Similar to other hot desert finds, and contrary to the falls and Antarctica finds, both collections show an overabundance of H chondrites. A recovery density can be calculated only for the El Médano collection and gives 251 and 168 meteorites larger than 10 g km-2, before and after pairing, respectively. It is by far the densest collection area described in hot deserts. The Atacama Desert is known to have been hyperarid for a long period of time and, based on cosmic-ray exposure ages on the order of 1-10 Ma, to have been stable over a period of time of several million years. Such a high meteorite concentration might be explained invoking either a yet unclear concentration mechanism (possibly related to downslope creeping) or a previously underestimated meteorite flux in previous studies or an average terrestrial age over 2 Myr. This last hypothesis is supported by the high weathering grade of meteorites and by the common terrestrial fragmentation (with fragments scattered over a few meters) of recovered meteorites.

  16. Solar Observations with the Atacama Large Millimeter/submillimeter Array (ALMA)

    Science.gov (United States)

    Kobelski, A.; ALMA Solar Development Team

    2016-04-01

    The Atacama Large Millimeter/Submillimeter Array (ALMA) is a joint North American, European, and East Asian project that opens the mm-sub mm wavelength part of the electromagnetic spectrum for general astrophysical exploration, providing high-resolution imaging in frequency bands currently ranging from 84 GHz to 950 GHz (300 microns to 3 mm). It is located in the Atacama desert in northern Chile at an elevation of 5000 m. Despite being a general purpose instrument, provisions have been made to enable solar observations with ALMA. Radiation emitted at ALMA wavelengths originates mostly from the chromosphere, which plays an important role in the transport of matter and energy, and the in heating the outer layers of the solar atmosphere. Despite decades of research, the solar chromosphere remains a significant challenge: both to observe, owing to the complicated formation mechanisms of currently available diagnostics; and to understand, as a result of the complex nature of the structure and dynamics of the chromosphere. ALMA has the potential to change the scene substantially as it serves as a nearly linear thermometer at high spatial and temporal resolution, enabling us to study the complex interaction of magnetic fields and shock waves and yet-to-be-discovered dynamical processes. Moreover, ALMA will play an important role in the study of energetic emissions associated with solar flares at sub-THz frequencies.

  17. The Atacama B-Mode Search: CMB Polarimetry with Transition-Edge-Sensor Bolometers

    CERN Document Server

    Essinger-Hileman, T; Beall, J A; Cho, H M; Fowler, J; Halpern, M; Hasselfield, M; Irwin, K D; Marriage, T A; Niemack, M D; Page, L; Parker, L P; Pufu, S; Staggs, S T; Stryzak, O; Visnjic, C; Yoon, K W; Zhao, Y

    2010-01-01

    The Atacama B-mode Search (ABS) experiment is a 145 GHz polarimeter designed to measure the B-mode polarization of the Cosmic Microwave Background (CMB) at large angular scales. The ABS instrument will ship to the Atacama Desert of Chile fully tested and ready to observe in 2010. ABS will image large-angular-scale CMB polarization anisotropies onto a focal plane of 240 feedhorn-coupled, transition-edge sensor (TES) polarimeters, using a cryogenic crossed-Dragone design. The ABS detectors, which are fabricated at NIST, use orthomode transducers to couple orthogonal polarizations of incoming radiation onto separate TES bolometers. The incoming radiation is modulated by an ambient-temperature half-wave plate in front of the vacuum window at an aperture stop. Preliminary detector characterization indicates that the ABS detectors can achieve a sensitivity of 300 $\\mu K \\sqrt{s}$ in the field. This paper describes the ABS optical design and detector readout scheme, including feedhorn design and performance, magneti...

  18. Characterizing Atacama B-mode Search Detectors with a Half-Wave Plate

    CERN Document Server

    Simon, S M; Campusano, L E; Choi, S K; Crowley, K T; Essinger-Hileman, T; Gallardo, P; Ho, S P; Kusaka, A; Nati, F; Palma, G A; Page, L A; Raghunathan, S; Staggs, S T

    2015-01-01

    The Atacama B-Mode Search (ABS) instrument is a cryogenic ($\\sim$10 K) crossed-Dragone telescope located at an elevation of 5190 m in the Atacama Desert in Chile that observed for three seasons between February 2012 and October 2014. ABS observed the Cosmic Microwave Background (CMB) at large angular scales ($40<\\ell<500$) to limit the B-mode polarization spectrum around the primordial B-mode peak from inflationary gravity waves at $\\ell \\sim100$. The ABS focal plane consists of 480 transition-edge sensor (TES) bolometers. They are coupled to orthogonal polarizations from a planar ortho-mode transducer (OMT) and observe at 145 GHz. ABS employs an ambient-temperature, rapidly rotating half-wave plate (HWP) to mitigate systematic effects and move the signal band away from atmospheric $1/f$ noise, allowing for the recovery of large angular scales. We discuss how the signal at the second harmonic of the HWP rotation frequency can be used for data selection and for monitoring the detector responsivities.

  19. Diversidad y patrones de distribución geográfica de insectos coleópteros en ecosistemas desérticos de la región de Antofagasta, Chile Diversity and geographic distribution patterns of coleopteran insects in desert ecosystems of the Antofagasta region, Chile

    Directory of Open Access Journals (Sweden)

    VIVIANE JEREZ

    2000-03-01

    their distribution ranges are given. The possible biogeographic relationships which could exist between the different described ecosystems of the region were analyzed. In this analysis, a coleopteran species inventory was elaborated based upon the literature, collected material from museums, and observations from field work. The spatial distribution of the taxa was established in relation to 11 described ecosystems for the Region and the endemic areas were determined using a biogeographic parsimony analysis. The taxonomic composition of Coleoptera is comprised of 21 families, 86 genera, and 167 species, with Tenebrionidae as the most diverse having 23 genera and 78 species. The Subdesertic steppe of the puna (57 sp., Coastal desert of Tocopilla (50 sp., Desert of Atacama saltflat (35 sp., Coastal desert of Taltal (32 sp., Aluvian Desert (22 sp., and the Shrubery steppe (17 sp. are the ecosystems that present the most diversification. However, the Coastal desert of Tocopilla (72%, Coastal desert of Taltal (62.5%, Subdesertic steppe of the puna (55.8%, Desert of Atacama saltflat (51.4%, Shrubery steppe (47%, and the Aluvian desert (36.3% have the highest percentages of endemism. Three areas of endemism are defined for the Region of Antofagasta, which correspond to three ecosystems distributed in an altitudinal gradient: Coastal desert, Aluvian desert, and Tropical zone

  20. The Presence and Distribution of Salts as a Palaeoprecipitation Proxy in Atacama Soils

    Science.gov (United States)

    McKay, Lucy; Claire, Mark

    2016-04-01

    The Atacama Desert in northern Chile (17 to 27° S) is the driest and oldest warm desert on Earth and contains unique abundances of atmospherically-derived salts such as nitrate and perchlorate (Ewing et al., 2006; Jackson et al., 2015). Near-surface accumulation of extremely soluble salts indicates a scarcity of long-term precipitation-driven leaching from Atacama soils. The prolonged absence of substantial precipitation has enabled nitrate and perchlorate to accumulate for millions of years to measurable levels, while interacting with occasional rainfall to move vertically through the soil profile. We investigate the near-surface presence and distribution of atmospherically-generated soluble salts at Earth's most arid extreme, aiming to quantify Atacama palaeoprecipitation during the Quaternary. Previous field and modelling studies have revealed a strong correlation between the depth of peak nitrate and past precipitation events in the U.S. desert southwest (Walvoord et al., 2003; Marion et al., 2008). We extend these studies to regions of much lower rainfall, and report the largest ever near-surface concentrations of nitrate and perchlorate in Earth's soils. We present salt distribution profiles from soil pits in six localities, spanning ~1000 km of the south-to-north (27° to 24° S) natural rainfall and ecosystem function gradient that spans the arid to hyperarid transition (from 20 to 100 mg/kg at 120 cm depth, with an astonishing 22 mg/kg at the surface. In comparison, perchlorate peaks at ~4 mg/kg at 90 cm depth in our Yungay soil profile. Given that perchlorate is the most soluble naturally-existing salt, "km40" and "PONR" indicate a complete lack of recent precipitation and are candidates for the driest place on Earth. We use the numerical model of Marion et al. (2008) to quantitatively constrain the maximum rainfall distributions and event frequencies that are permitted by our measured profiles. Our Atacama soil profiles exhibit vertical variation in

  1. Oxygen-17 anomaly in soil nitrate: A new precipitation proxy for desert landscapes

    Science.gov (United States)

    Wang, Fan; Ge, Wensheng; Luo, Hao; Seo, Ji-Hye; Michalski, Greg

    2016-03-01

    The nitrogen cycle in desert soil ecosystems is particularly sensitive to changes in precipitation, even of relatively small magnitude and short duration, because it is already under water stress. This suggests that desert soils may have preserved past evidence of small variations in continental precipitation. We have measured nitrate (NO3-) concentrations in soils from the Atacama (Chile), Kumtag (China), Mojave (US), and Thar (India) deserts, and stable nitrogen and oxygen isotope (15N, 17O, and 18O) abundances of the soil NO3-. 17O anomalies (Δ17O), the deviations from the mass-independent isotopic fractionation, were detected in soil NO3- from almost all sites of these four deserts. There was a strong negative correlation between the mean annual precipitation (MAP) and soil NO3- Δ17O values (Δ soil 17O NO3). This MAP- Δ soil 17O NO3 correlation advocated Δ soil 17O NO3 as a new precipitation proxy and was then used to assess precipitation changes in southwestern US at the Pliocene-Pleistocene boundary, in South America during the Miocene, and the Sahara Desert in the past 10 kyr using NO3- Δ17O in paleosols or ancient aquifers. Global and the US maps of surface Δ soil 17O NO3 were also projected with available MAP datasets based on the MAP- Δ soil 17O NO3 model.

  2. Source apportionment of PM{sub 10} and PM{sub 2.5} in a desert region in northern Chile

    Energy Technology Data Exchange (ETDEWEB)

    Jorquera, Héctor, E-mail: jorquera@ing.puc.cl; Barraza, Francisco

    2013-02-01

    Estimating contributions of anthropogenic sources to ambient particulate matter (PM) in desert regions is a challenging issue because wind erosion contributions are ubiquitous, significant and difficult to quantify by using source-oriented, dispersion models. A receptor modeling analysis has been applied to ambient PM{sub 10} and PM{sub 2.5} measured in an industrial zone ∼ 20 km SE of Antofagasta (23.63°S, 70.39°W), a midsize coastal city in northern Chile; the monitoring site is within a desert region that extends from northern Chile to southern Perú. Integrated 24-hour ambient samples of PM{sub 10} and PM{sub 2.5} were taken with Harvard Impactors; samples were analyzed by X Ray Fluorescence, ionic chromatography (NO{sub 3}{sup −} and SO{sub 4}{sup =}), atomic absorption (Na{sup +}, K{sup +}) and thermal optical transmission for elemental and organic carbon determination. Receptor modeling was carried out using Positive Matrix Factorization (US EPA Version 3.0); sources were identified by looking at specific tracers, tracer ratios, local winds and wind trajectories computed from NOAA's HYSPLIT model. For the PM{sub 2.5} fraction, six contributions were found — cement plant, 33.7 ± 1.3%; soil dust, 22.4 ± 1.6%; sulfates, 17.8 ± 1.7%; mineral stockpiles and brine plant, 12.4 ± 1.2%; Antofagasta, 8.5 ± 1.3% and copper smelter, 5.3 ± 0.8%. For the PM{sub 10} fraction five sources were identified — cement plant, 38.2 ± 1.5%; soil dust, 31.2 ± 2.3%; mineral stockpiles and brine plant, 12.7 ± 1.7%; copper smelter, 11.5 ± 1.6% and marine aerosol, 6.5 ± 2.4%. Therefore local sources contribute to ambient PM concentrations more than distant sources (Antofagasta, marine aerosol) do. Soil dust is enriched with deposition of marine aerosol and calcium, sulfates and heavy metals from surrounding industrial activities. The mean contribution of suspended soil dust to PM{sub 10} is 50 μg/m{sup 3} and the peak daily value is 104 μg/m{sup 3}. For the

  3. Subsistencia y utilización de recursos faunísticos en economías de caza-recolección de la puna de Atacama, norte de Chile

    Directory of Open Access Journals (Sweden)

    Olaff Olmos Figueroa

    1983-06-01

    Full Text Available Se evalúan dos muestras cuantitativas de restos orgánicos provenientesde los campamentos precerámicos tardíos Tulán-52 y Puripica-1, ubicados enla Puna de Atacama, cronológicamente datddos entre los 2.100-2.300 años a.c.,valorizando las evidencias óseas como indicadores de proceso en función deprocedimientos de captura, hábitos de consumo y distribución estratigrafica. De esta información se infiere [as condiciones y el carácter de la adaptactón a zonas áridas y semiáridas de poblaciones que ocuparon los ambientes de laPuna y el Salar de Atacama durante el Periodo Arcaico Tardío.           

  4. Atacama Compact Array Antennas

    OpenAIRE

    Saito, Masao; Inatani, Junji; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high...

  5. The Optical/Infrared Astronomical Quality of High Atacama Sites. I. Preliminary Results of Optical Seeing

    Science.gov (United States)

    Giovanelli, Riccardo; Darling, Jeremy; Sarazin, Marc; Yu, Jennifer; Harvey, Paul; Henderson, Charles; Hoffman, William; Keller, Luke; Barry, Don; Cordes, James; Eikenberry, Stephen; Gull, George; Harrington, Joseph; Smith, J. D.; Stacey, Gordon; Swain, Mark

    2001-07-01

    The region surrounding the Llano de Chajnantor, a high-altitude plateau in the Atacama Desert in northern Chile, has caught the attention of the astronomical community for its potential as an observatory site. Combining high elevation and extremely low atmospheric water content, the Llano has been chosen as the future site of the Atacama Large Millimeter Array. We have initiated a campaign to investigate the astronomical potential of the region in the optical/infrared. Here we report on an aspect of our campaign aimed at establishing a seeing benchmark to be used as a reference for future activities in the region. After a brief description of the region and its climate, we describe the results of an astronomical seeing campaign, carried out with a Differential Image Motion Monitor that operates at 0.5 μm wavelength. The seeing at the Llano altitude of 5000 m, measured over 7 nights in 1998 May, yielded a median FWHM of 1.1". However, the seeing decreased to 0.7" at a modest 100 m gain above the plateau (Cerro Chico), as measured over 38 nights spread between 1998 July and 2000 October. Neither of these represents the best seeing expected in the region; the set of measurements provides a reference base for simultaneous dual runs at Cerro Chico and at other sites of interest in the region, currently underway. A comparison between simultaneous measurements at Cerro Chico and Cerro Paranal indicates that the seeing at Cerro Chico is about 12% better than that at Paranal. The percentage of optically photometric nights in the Chajnantor region is about 60%, while that of nights useful for astronomical work is near 80%.

  6. Segmentación, cinemática y cronología relativa de la deformación tardía de la Falla Salar del Carmen, Sistema de Fallas de Atacama, (23°40'S, norte de Chile

    Directory of Open Access Journals (Sweden)

    Gabriel González

    2003-12-01

    Full Text Available La Falla Salar del Carmen es una de las estructuras principales del Sistema de Fallas de Atacama, que se ubica al este de Antofagasta en el borde oriental de Sierra del Ancla. El evento de deformación más reciente a lo largo de esta falla dio origen a la formación de siete segmentos de falla de orientación submeridiana, cuya longitud promedio es de 8 km. Los segmentos muestran un escalonamiento lateral izquierdo, cuyos extremos están ligados por fallas de transferencia. La deformación formó escarpes de 0,2 a 9 m de altura en depósitos aluviales pliocénicos. Los escarpes más antiguos están caracterizados por un talud de detritos, en tanto que en los más jóvenes se conserva aún la cara libre. El proceso de formación de escarpes estuvo controlado por deslizamientos normales a lo largo de fallas subverticales. El estado de deformación está dado por un eje de extensión buzante 33° en la dirección N90E y una dirección de acortamiento buzante 56&° en la dirección N87W. La estimación de la edad mediante datación morfológica de escarpes, indica que las fallas no serían más antiguas que el Pleistoceno tardío (Segmentation, kinematics and relative chronology of the late deformation of Salar del Carmen Fault, Atacama Fault System (23°40'S, northern Chile. The Salar del Carmen Fault is the most important strand of the Atacama Fault System exposed along the eastern border of the Sierra del Ancla. The younger slip event along this fault forms seven consecutive 8 km long north-south striking fault segments that cut Pliocene alluvial fans. The segments show a left stepping geometry, whose terminal parts are linked by transfer faults. The scarps were formed by east-down-dip-parallel slip along subvertical fault planes. The strain state is characterized by a N90E trending and 33° plunging extensional axis a N87W trending and 56° plunging shortening axis. Ruptures along the fault form 0.2-9 m high fault scarps. Older scarps are

  7. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  8. The Atacama Cosmology Telescope

    OpenAIRE

    Kosowsky, Arthur

    2004-01-01

    The Atacama Cosmology Telescope (ACT) project is described. This multi-institution collaboration aims to produce arcminute-resolution and micro-Kelvin sensitivity maps of the microwave background temperature over 200 square degrees of the sky in three frequency bands. We give a brief overview of the scientific motivations for such a map, followed by a design outline of our six-meter custom telescope, an overview of our proposed bolometer array detector technology, and site considerations and ...

  9. Observations of rapid-fire event tremor at Lascar volcano, Chile

    Directory of Open Access Journals (Sweden)

    H. Rademacher

    1996-06-01

    Full Text Available During the Proyecto de Investigaciòn Sismològica de la Cordillera Occidental (PISCO '94 in the Atacama desert of Northern Chile, a continuously recording broadband seismic station was installed to the NW of the currently active volcano, Lascar. For the month of April, 1994, an additional network of three, short period, three-component stations was deployed around the volcano to help discriminate its seismic signals from other local seismicity. During the deployment, the volcanic activity at Lascar appeared to be limited mainly to the emission of steam and SO2. Tremor from Lascar is a random, «rapid-fire» series of events with a wide range of amplitudes and a quasi-fractal structure. The tremor is generated by an ensemble of independent elementary sources clustered in the volcanic edifice. In the short-term, the excitation of the sources fluctuates strongly, while the long-term power spectrum is very stationary.

  10. ALMA communication backbone in Chile goes optical

    Science.gov (United States)

    Filippi, G.; Ibsen, J.; Jaque, Sandra; Liello, F.; Navarro, C.

    2014-07-01

    High-bandwidth communication has become a key factor for scientific installations as Observatories. This paper describes the technical, organizational, and operational goals and the level of completion of the ALMA Optical Link Project. The project focus is the creation and operation of an effective and sustainable communication infrastructure to connect the ALMA Observatory, located in the Atacama Desert, in the Northern region of Chile, with the point of presence in ANTOFAGASTA, about 400km away, of the EVALSO infrastructure, and from there to the Central Office in the Chilean capital, Santiago. This new infrastructure that will be operated in behalf of ALMA by REUNA, the Chilean National Research and Education Network, will use state of the art technologies, like dark fiber from newly built cables and DWDM transmission, allowing extending the reach of high capacity communication to the remote region where the Observatory is located. When completed, the end-to-end Gigabit-per-second (Gbps) capable link will provide ALMA with a modern, effective, robust, communication infrastructure capable to cope with present and future demands, like those coming from fast growing data transfer to rapid response mode, from remote monitoring and engineering to virtual presence.

  11. Searching for Life with Rovers: Exploration Methods & Science Results from the 2004 Field Campaign of the "Life in the Atacama" Project and Applications to Future Mars Missions

    Science.gov (United States)

    Cabrol, N. A.a; Wettergreen, D. S.; Whittaker, R.; Grin, E. A.; Moersch, J.; Diaz, G. Chong; Cockell, C.; Coppin, P.; Dohm, J. M.; Fisher, G.

    2005-01-01

    The Life In The Atacama (LITA) project develops and field tests a long-range, solarpowered, automated rover platform (Zo ) and a science payload assembled to search for microbial life in the Atacama desert. Life is barely detectable over most of the driest desert on Earth. Its unique geological, climatic, and biological evolution have created a unique training site for designing and testing exploration strategies and life detection methods for the robotic search for life on Mars.

  12. Astronomy Outreach Activities in Chile: IYA 2009 and Beyond

    Science.gov (United States)

    Vogt, N.; Evans, M.; Aranda, J.; Gotta, V.; Monsalves, A.; Puebla, E.

    2012-08-01

    In Chile, one of the developing countries in Latin-America, there are large social differences that persist between the richest and the poorest citizens. On the other hand, Chile has the advantage of a special and unique resource, the incomparably clear and dry skies in the desert of Atacama in the north of the country. This advantage is being exploited by the installation of large and powerful international observatories. However, the Chilean people's perception of this resource and the corresponding advantages for their country are still underdeveloped and rather poor. Therefore, we have been conducting successful outreach activities at all levels during the past few years, with special highlights during the International Year of Astronomy 2009, including participation of our undergraduate physics and astronomy students, the local media like newspapers, radio, and TV stations, talks and workshops in schools, popular talks for the general public, exhibitions, contests, and other multi-media efforts. We briefly describe these activities and outline the difference between our situation and that existing in developed countries like the USA.

  13. Subsistencia y utilización de recursos faunísticos en economías de caza-recolección de la puna de Atacama, norte de Chile

    OpenAIRE

    Olaff Olmos Figueroa

    1983-01-01

    Se evalúan dos muestras cuantitativas de restos orgánicos provenientesde los campamentos precerámicos tardíos Tulán-52 y Puripica-1, ubicados enla Puna de Atacama, cronológicamente datddos entre los 2.100-2.300 años a.c.,valorizando las evidencias óseas como indicadores de proceso en función deprocedimientos de captura, hábitos de consumo y distribución estratigrafica. De esta información se infiere [as condiciones y el carácter de la adaptactón a zonas áridas y semiáridas de poblaciones que...

  14. El Qhapaqñan entre Atacama y Lípez The Qhapaqñan between Atacama and Lípez

    OpenAIRE

    Nielsen, Axel E.; José Berenguer; Cecilia Sanhueza

    2006-01-01

    Este trabajo describe tramos de dos ramales del Qhapaqñan que comunican el desierto de Atacama (Región de Antofagasta, Chile) con el Altiplano de Lípez (Departamento Potosí, Bolivia). El primero de ellos, que se extiende entre Licancabur y Laguna Chojllas, formaba parte de una vía que vinculaba el nodo inkaico de San Pedro de Atacama con los valles chichas y la Puna argentina. El segundo ingresa a Bolivia por el Portezuelo del Inca procedente de la cuenca del río Salado y se dirige directamen...

  15. Atmospheric origins of perchlorate on Mars and in the Atacama

    Science.gov (United States)

    Catling, D. C.; Claire, M. W.; Zahnle, K. J.; Quinn, R. C.; Clark, B. C.; Hecht, M. H.; Kounaves, S.

    2010-01-01

    Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products. With this analogy, we propose that the arid environment on Mars may have given rise to perchlorate through the action of atmospheric oxidants. A variety of hypothetical pathways can be proposed including photochemical reactions, electrostatic discharge, and gas-solid reactions. Because perchlorate-rich deposits in the Atacama desert are closest in abundance to perchlorate measured at NASA's Phoenix Lander site, we made a preliminary study of the means to produce Atacama perchlorate to help shed light on the origin of Martian perchlorate. We investigated gas phase pathways using a 1-D photochemical model. We found that perchlorate can be produced in sufficient quantities to explain the abundance of perchlorate in the Atacama from a proposed gas phase oxidation of chlorine volatiles to perchloric acid. The feasibility of gas phase production for the Atacama provides justification for future investigations of gas phase photochemistry as a possible source for Martian perchlorate.

  16. Unique communities of anoxygenic phototrophic bacteria in saline lakes of Salar de Atacama (Chile): evidence for a new phylogenetic lineage of phototrophic Gammaproteobacteria from pufLM gene analyses.

    Science.gov (United States)

    Thiel, Vera; Tank, Marcus; Neulinger, Sven C; Gehrmann, Linda; Dorador, Cristina; Imhoff, Johannes F

    2010-12-01

    Phototrophic bacteria are important primary producers of salt lakes in the Salar de Atacama and at times form visible mass developments within and on top of the lake sediments. The communities of phototrophic bacteria from two of these lakes were characterized by molecular genetic approaches using key genes for the biosynthesis of the photosynthetic apparatus in phototrophic purple bacteria (pufLM) and in green sulfur bacteria (fmoA). Terminal restriction fragment length polymorphism of the pufLM genes indicated high variability of the community composition between the two lakes and subsamples thereof. The communities were characterized by the dominance of a novel, so far undescribed lineage of pufLM containing bacteria and the presence of representatives related to known halophilic Chromatiaceae and Ectothiorhodospiraceae. In addition, the presence of BChl b-containing anoxygenic phototrophic bacteria and of aerobic anoxygenic bacteria was indicated. Green sulfur bacteria were not detected in the environmental samples, although a bacterium related to Prosthecochloris indicum was identified in an enrichment culture. This is the first comprehensive description of phototrophic bacterial communities in a salt lake of South America made possible only due to the application of the functional pufLM genes. PMID:20868378

  17. Assessing the performance of hybrid CSP+PV plants in northern Chile

    Science.gov (United States)

    Starke, Allan; Cardemil, José M.; Escobar, Rodrigo; Colle, Sergio

    2016-05-01

    The electricity systems in Chile are characterized by a variable hourly demand in the central grid and an almost constant demand in the northern grid, which require different operation strategies for solar power plants depending on their location. Hybridizing a CSP plant with a PV plant can increase the whole plant capacity factor by allowing thermal energy to be stored while the PV plant is in production and thus help to achieve a fully dispatchable solar electricity production system. A thermal and economic analysis of hybrid CSP+PV plants is conducted considering a range of plant capacities based on a parabolic trough plant with the addition of a PV plant for the environmental conditions of Crucero in Northern Chile, which is a hotspot for solar energy development in the country. The study considers a parametric analysis and optimization of the storage and power block sizes for the CSP plant in terms of the levelized cost of energy (LCOE) for varying PV plant nominal capacity. The annual production of the plants are calculated by using the Transient System Simulation program (TRNSYS), which uses a new component library developed for that purpose. The results show good agreement with other software packages as well as with actual data from currently operating CSP plants. The adopted approach helps the proper assessment of the integration of different technologies, since it uses the well-kwon modular structure of the TRNSYS. Regarding the potential for the hybrid solar-solar plants in the Atacama Desert, the high level of irradiation available in Chile can provide a competitive electricity cost, allowing to investors the access to PPA contracts with mining companies in northern Chile. Additionally, the optimization analysis shows that the northern regions of Chile present an outstanding potential for the deployment of such projects.

  18. The Atacama Cosmology Telescope: The Receiver and Instrumentation

    Science.gov (United States)

    Swetz, D. S.; Ade, P. A. R.; Amiri, M.; Appel, J. W.; Burger, B.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Hincks, A. D.; Irwin, K. D.; Jarosik, N.; Kaul, M.; Klein, J.; Marsden, D.; Thornton, R.; Mauskopf, P.; Niemack, M. D.; Page, L. A.; Parker, L.

    2010-01-01

    The Atacama Cosmology Telescope was designed to measure small-scale anisotropies in the Cosmic Microwave Background and detect galaxy clusters through the Sunyaev-Zel'dovich effect. The instrument is located on Cerro Taco in the Atacama Desert, at an altitude of 5190 meters. A six-met.er off-axis Gregorian telescope feeds a new type of cryogenic receiver, the Millimeter Bolometer Array Camera. The receiver features three WOO-element arrays of transition-edge sensor bolometers for observations at 148 GHz, 218 GHz, and 277 GHz. Each detector array is fed by free space mm-wave optics. Each frequency band has a field of view of approximately 22' x 26'. The telescope was commissioned in 2007 and has completed its third year of operations. We discuss the major components of the telescope, camera, and related systems, and summarize the instrument performance.

  19. Tibet's Ali: Asia's Atacama?

    Science.gov (United States)

    Ye, Quan-Zhi; Su, Meng; Li, Hong; Zhang, Xinmin

    2016-03-01

    The Ngari (Ali) prefecture of Tibet, one of the highest areas in the world, has recently emerged as a promising site for future astronomical observation. Here, we use 31 yr of reanalysis data from the Climate Forecast System Reanalysis to examine the astroclimatology of Ngari, using the recently-erected Ali Observatory at Shiquanhe (5047 m above mean sea level) as the representative site. We find the percentage of photometric night, median atmospheric seeing and median precipitable water vapour of the Shiquanhe site to be 57 per cent, 0.8 arcsec and 2.5 mm, comparable some of the world's best astronomical observatories. Additional calculation supports the Shiquanhe region as one of the better sites for astronomical observations over the Tibetan Plateau. Based on the studies taken at comparable environment at Atacama, extraordinary observing condition may be possible at the few vehicle-accessible 6000 m heights in the Shiquanhe region. Such possibility should be thoroughly investigated in future.

  20. The Atacama Large Millimeter Array (ALMA)

    Science.gov (United States)

    1999-06-01

    The Atacama Large Millimeter Array (ALMA) is the new name [2] for a giant millimeter-wavelength telescope project. As described in the accompanying joint press release by ESO and the U.S. National Science Foundation , the present design and development phase is now a Europe-U.S. collaboration, and may soon include Japan. ALMA may become the largest ground-based astronomy project of the next decade after VLT/VLTI, and one of the major new facilities for world astronomy. ALMA will make it possible to study the origins of galaxies, stars and planets. As presently envisaged, ALMA will be comprised of up to 64 12-meter diameter antennas distributed over an area 10 km across. ESO PR Photo 24a/99 shows an artist's concept of a portion of the array in a compact configuration. ESO PR Video Clip 03/99 illustrates how all the antennas will move in unison to point to a single astronomical object and follow it as it traverses the sky. In this way the combined telescope will produce astronomical images of great sharpness and sensitivity [3]. An exceptional site For such observations to be possible the atmosphere above the telescope must be transparent at millimeter and submillimeter wavelengths. This requires a site that is high and dry, and a high plateau in the Atacama desert of Chile, probably the world's driest, is ideal - the next best thing to outer space for these observations. ESO PR Photo 24b/99 shows the location of the chosen site at Chajnantor, at 5000 meters altitude and 60 kilometers east of the village of San Pedro de Atacama, as seen from the Space Shuttle during a servicing mission of the Hubble Space Telescope. ESO PR Photo 24c/99 and ESO PR Photo 24d/99 show a satellite image of the immediate vicinity and the site marked on a map of northern Chile. ALMA will be the highest continuously operated observatory in the world. The stark nature of this extreme site is well illustrated by the panoramic view in ESO PR Photo 24e/99. High sensitivity and sharp images ALMA

  1. Eventos El Niño y episodios lluviosos en el desierto de Atacama: el registro de los últimos dos siglos

    Directory of Open Access Journals (Sweden)

    1995-01-01

    Niño influya directamente sobre la magnitud de las precipitaciones. EL NIÑO EVENTS AND RAINFALL EPISODES IN THE ATACAMA DESERT: THE RECORD OF THE LAST TWO CENTURIES. Along the Pacific coast of South America, El Niño events are characterized by rainfall excesses in northern Peru and in central Chile, while the Altiplano of southern Peru and Bolivia experiment dramatic droughts. In northern Chile rainfall are particularly scarce, and up to now the rainy episodes were not viewed as closely related to El Niño events. In this paper are compiled available data (instrumental record and anecdotic information on rainfall from the Atacama Desert and, more generally from the area extending from Arequipa to Coquimbo, during the last two centuries. The analysis of the gathered data shows that most of the rainy episodes registered in the Norte Grande (Atacama Desert are coeval with El Niño events, although no direct relationship was found between the intensity of the individual El Niño events and the amount of precipitation.

  2. ANIR : Atacama Near-Infrared Camera for the 1.0-m miniTAO Telescope

    OpenAIRE

    Konishi, Masahiro; Motohara, Kentaro; Tateuchi, Ken; TAKAHASHI, Hidenori; Kitagawa, Yutaro; Kato, Natsuko; Sako, Shigeyuki; Uchimoto, Yuka K.; Toshikawa, Koji; Ohsawa, Ryou; Yamamuro, Tomoyasu; Asano, Kentaro; Ita, Yoshifusa; Kamizuka, Takafumi; Komugi, Shinya

    2015-01-01

    We have developed a near-infrared camera called ANIR (Atacama Near-InfraRed camera) for the University of Tokyo Atacama Observatory 1.0m telescope (miniTAO) installed at the summit of Cerro Chajnantor (5640 m above sea level) in northern Chile. The camera provides a field of view of 5'.1 $\\times$ 5'.1 with a spatial resolution of 0".298 /pixel in the wavelength range of 0.95 to 2.4 $\\mu$m. Taking advantage of the dry site, the camera is capable of hydrogen Paschen-$\\alpha$ (Pa$\\alpha$, $\\lamb...

  3. Tibet's Ali: Asia's Atacama?

    CERN Document Server

    Ye, Quan-Zhi; Li, Hong; Zhang, Xinmin

    2015-01-01

    The Ngari (Ali) prefecture of Tibet, one of the highest areas in the world, has recently emerged as a promising site for future astronomical observation. Here we use 31 years of reanalysis data from the Climate Forecast System Reanalysis (CFSR) to examine the astroclimatology of Ngari, using the recently-erected Ali Observatory at Shiquanhe (5~047~m above mean sea level) as the representative site. We find the percentage of photometric night, median atmospheric seeing and median precipitable water vapor (PWV) of the Shiquanhe site to be $57\\%$, $0.8"$ and 2.5~mm, comparable some of the world's best astronomical observatories. Additional calculation supports the Shiquanhe region as one of the better sites for astronomical observations over the Tibetan Plateau. Based on the studies taken at comparable environment at Atacama, extraordinary observing condition may be possible at the few vehicle-accessible 6~000~m heights in the Shiquanhe region. Such possibility should be thoroughly investigated in future.

  4. First record of folivory on a newly documented host plant for the little known geometrid moth Eupithecia yubitzae Vargas & Parra (Lepidoptera, Geometridae in northern Chile

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2015-06-01

    Full Text Available The native tree Schinus molle (Anacardiacae is reported for the first time as a host plant for larvae of the little known geometrid moth Eupithecia yubitzae Vargas & Parra (Lepidoptera, Geometridae in the Atacama Desert of northern Chile, based on morphology and DNA barcodes. This discovery importantly expands the host range of E. yubitzae, as previous records were restricted to Fabaceae trees. Larvae were previously known as florivorous, while these were found to be folivorous on S. molle. Furthermore, host-associated cryptic larval polychromatism was detected, as larvae collected on S. molle were found to be mostly pale green, contrasting with the dark yellow ground color of the larvae typically collected on fabaceous host plants.

  5. Long-term denudation rates from the Central Andes (Chile) estimated from a digital elevation model using the black top hat function and inverse distance weighting : implications for the neogene climate of the Atacama Desert

    OpenAIRE

    Riquelme, R.; Darrozes, J; Maire, E.; Hérail, Gérard; J. C. Soula

    2008-01-01

    A methodology for determining long-term denudation rates from morphologic markers in a Digital Elevation Model (DEM) is checked by a comparative study of two drainage basins in the Precordillera of the Central Andes. In both cases the initial configuration of an incised pediment surface has been restored by using two different methods: the Black Top Hat (BTH) function and the Inverse Distance Weighting (IDW) interpolation. Where vertical incision and hillslope erosion are recorded, the 1DW ap...

  6. Partitioning geochemistry of arsenic and antimony, El Tatio Geyser Field, Chile

    International Nuclear Information System (INIS)

    The abundance of As and Sb in aqueous, mineral and biological reservoirs was examined at El Tatio Geyser Field, a unique hydrothermal basin located in the Atacama Desert region of Chile. Here the concentration of total As and Sb in hydrothermal springs and discharge streams are the highest reported for a natural surface water, and the geyser basin represents a significant source of toxic elements for downstream users across Region II, Chile. The geyser waters are near neutral Na:Cl type with ∼0.45 and 0.021 mmol L-1 total As and Sb, respectively, primarily in the reduced (III) redox state at the discharge with progressive oxidation downstream. The ferric oxyhydroxides associated with the microbial mats and some mineral precipitates accumulate substantial As that was identified as arsenate by XAS analysis (>10 wt% in the mats). This As is easily mobilized by anion exchange or mild dissolution of the HFO, and the ubiquitous microbial mats represent a significant reservoir of As in this system. Antimony, in contrast, is not associated with the mineral ferric oxides or the biomats, but is substantially enriched in the silica matrix of the geyserite precipitates, up to 2 wt% as Sb2O3. Understanding the mobility and partitioning behavior of these metalloids is critical for understanding their eventual impact on regional water management.

  7. Partitioning geochemistry of arsenic and antimony, El Tatio Geyser Field, Chile

    Energy Technology Data Exchange (ETDEWEB)

    Landrum, J.T. [Department of Geological Sciences, The University of Texas, Austin, TX 78759 (United States); Bennett, P.C., E-mail: pbennett@mail.utexas.edu [Department of Geological Sciences, University of Texas, Austin, TX 78759 (United States); Engel, A.S. [Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803 (United States); Alsina, M.A.; Pasten, P.A. [Departamento de Ingenieria Hidraulica y Ambiental, Pontificia Universidad Catolica de Chile, Santiago (Chile); Milliken, K. [Department of Geological Sciences, University of Texas, Austin, TX 78759 (United States)

    2009-04-15

    The abundance of As and Sb in aqueous, mineral and biological reservoirs was examined at El Tatio Geyser Field, a unique hydrothermal basin located in the Atacama Desert region of Chile. Here the concentration of total As and Sb in hydrothermal springs and discharge streams are the highest reported for a natural surface water, and the geyser basin represents a significant source of toxic elements for downstream users across Region II, Chile. The geyser waters are near neutral Na:Cl type with {approx}0.45 and 0.021 mmol L{sup -1} total As and Sb, respectively, primarily in the reduced (III) redox state at the discharge with progressive oxidation downstream. The ferric oxyhydroxides associated with the microbial mats and some mineral precipitates accumulate substantial As that was identified as arsenate by XAS analysis (>10 wt% in the mats). This As is easily mobilized by anion exchange or mild dissolution of the HFO, and the ubiquitous microbial mats represent a significant reservoir of As in this system. Antimony, in contrast, is not associated with the mineral ferric oxides or the biomats, but is substantially enriched in the silica matrix of the geyserite precipitates, up to 2 wt% as Sb{sub 2}O{sub 3}. Understanding the mobility and partitioning behavior of these metalloids is critical for understanding their eventual impact on regional water management.

  8. A microbial oasis in the hypersaline Atacama subsurface discovered by a life detector chip: implications for the search for life on Mars.

    Science.gov (United States)

    Parro, Victor; de Diego-Castilla, Graciela; Moreno-Paz, Mercedes; Blanco, Yolanda; Cruz-Gil, Patricia; Rodríguez-Manfredi, José A; Fernández-Remolar, David; Gómez, Felipe; Gómez, Manuel J; Rivas, Luis A; Demergasso, Cecilia; Echeverría, Alex; Urtuvia, Viviana N; Ruiz-Bermejo, Marta; García-Villadangos, Miriam; Postigo, Marina; Sánchez-Román, Mónica; Chong-Díaz, Guillermo; Gómez-Elvira, Javier

    2011-12-01

    The Atacama Desert has long been considered a good Mars analogue for testing instrumentation for planetary exploration, but very few data (if any) have been reported about the geomicrobiology of its salt-rich subsurface. We performed a Mars analogue drilling campaign next to the Salar Grande (Atacama, Chile) in July 2009, and several cores and powder samples from up to 5 m deep were analyzed in situ with LDChip300 (a Life Detector Chip containing 300 antibodies). Here, we show the discovery of a hypersaline subsurface microbial habitat associated with halite-, nitrate-, and perchlorate-containing salts at 2 m deep. LDChip300 detected bacteria, archaea, and other biological material (DNA, exopolysaccharides, some peptides) from the analysis of less than 0.5 g of ground core sample. The results were supported by oligonucleotide microarray hybridization in the field and finally confirmed by molecular phylogenetic analysis and direct visualization of microbial cells bound to halite crystals in the laboratory. Geochemical analyses revealed a habitat with abundant hygroscopic salts like halite (up to 260 g kg(-1)) and perchlorate (41.13 μg g(-1) maximum), which allow deliquescence events at low relative humidity. Thin liquid water films would permit microbes to proliferate by using detected organic acids like acetate (19.14 μg g(-1)) or formate (76.06 μg g(-1)) as electron donors, and sulfate (15875 μg g(-1)), nitrate (13490 μg g(-1)), or perchlorate as acceptors. Our results correlate with the discovery of similar hygroscopic salts and possible deliquescence processes on Mars, and open new search strategies for subsurface martian biota. The performance demonstrated by our LDChip300 validates this technology for planetary exploration, particularly for the search for life on Mars. PMID:22149750

  9. Astronomers Break Ground on Atacama Large Millimeter Array (ALMA) - World's Largest Millimeter Wavelength Telescope

    Science.gov (United States)

    2003-11-01

    Scientists and dignitaries from Europe, North America and Chile are breaking ground today (Thursday, November 6, 2003) on what will be the world's largest, most sensitive radio telescope operating at millimeter wavelengths . ALMA - the "Atacama Large Millimeter Array" - will be a single instrument composed of 64 high-precision antennas located in the II Region of Chile, in the District of San Pedro de Atacama, at the Chajnantor altiplano, 5,000 metres above sea level. ALMA 's primary function will be to observe and image with unprecedented clarity the enigmatic cold regions of the Universe, which are optically dark, yet shine brightly in the millimetre portion of the electromagnetic spectrum. The Atacama Large Millimeter Array (ALMA) is an international astronomy facility. ALMA is an equal partnership between Europe and North America, in cooperation with the Republic of Chile, and is funded in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Europe by the European Southern Observatory (ESO) and Spain. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO. " ALMA will be a giant leap forward for our studies of this relatively little explored spectral window towards the Universe" , said Dr. Catherine Cesarsky , Director General of ESO. "With ESO leading the European part of this ambitious and forward-looking project, the impact of ALMA will be felt in wide circles on our continent. Together with our partners in North America and Chile, we are all looking forward to the truly outstanding opportunities that will be offered by ALMA , also to young scientists and engineers" . " The U.S. National Science Foundation joins today with our North American partner, Canada, and with the European Southern Observatory, Spain, and Chile to prepare

  10. Hippidion saldiasi Roth, 1899 (Mammalia, Perissodactyla en el Pleistoceno tardío de Calama, norte de Chile Late Pleistocene Hippidion saldiasi Roth, 1899 (Mammalia, Perissodactyla from Calama, northern Chile

    Directory of Open Access Journals (Sweden)

    MARÍA TERESA ALBERDI

    2007-06-01

    Full Text Available Se describen restos del género Hippidion procedentes de la zona del desierto de Atacama (Calama, Segunda Región de Chile. El conjunto analizado corresponde a un esqueleto bastante completo proveniente del yacimiento Betecsa 1, así como escasas unidades del yacimiento Kamac Mayu. En ambos sitios se identifica H. saldiasi. A partir de dos dataciones radiométricas por AMS del ejemplar estudiado, los restos se sitúan estratigráficamente en el Pleistoceno Superior (21.070 ± 100 AP y 21.380 ± 100 14C AP. Se infieren datos ambientales y de dieta a partir de análisis de isótopos estables en los restos de Hippidion saldiasi del sitio Betecsa 1 cuyo valor de δ13C en hueso fue de -15,45 y el valor en esmalte de dientes fue de -16,68, sugiriendo una alimentación con pastos C3. El cráneo recuperado es el primero conocido de esta especieThis paper describes the Hippidion bones recovered from the Atacama Desert (Calama, Second Region of Chile. The analyzed assemblage corresponds to a nearly complete skeleton from Betecsa 1 site and more poorly preserved remains from Kamac Mayu site. In both H. saldiasi is identified. Two 14C radiometric determinations indicate late Pleistocene age for these remains (21,070 ± 100 BP and 21,380 ± 100 BP. Environmental and diet inferences from stable isotope analysis are also presented. The δ13C value from Betecsa 1 horses (-15.45 from bone sample and -16.68 from enamel sample suggest a dietary adaptation exclusively C3 feeders. This is the first skull and associated skeleton recovered of this species

  11. Eso's Situation in Chile

    Science.gov (United States)

    1995-02-01

    ESO, the European Southern Observatory, in reply to questions raised by the international media, as well as an ongoing debate about the so-called "Paranal case" in Chilean newspapers, would like to make a number of related observations concerning its status and continued operation in that country [1]. THE ESO OBSERVATORY SITES IN CHILE The European Southern Observatory, an international organisation established and supported by eight European countries, has been operating more than 30 years in the Republic of Chile. Here ESO maintains one of the world's prime astronomical observatories on the La Silla mountain in the southern part of the Atacama desert. This location is in the Fourth Chilean Region, some 600 km north of Santiago de Chile. In order to protect the La Silla site against dust and light pollution from possible future mining industries, roads and settlements, ESO early acquired the territory around this site. It totals about 825 sq. km and has effectively contributed to the preservation of its continued, excellent "astronomical" quality. Each year, more than 500 astronomers from European countries, Chile and elsewhere profit from this when they come to La Silla to observe with one or more of the 15 telescopes now located there. In 1987, the ESO Council [2] decided to embark upon one of the most prestigious and technologically advanced projects ever conceived in astronomy, the Very Large Telescope (VLT). It will consist of four interconnected 8.2-metre telescopes and will become the largest optical telescope in the world when it is ready. It is safe to predict that many exciting discoveries will be made with this instrument, and it will undoubtedly play a very important role in our exploration of the distant universe and its many mysteries during the coming decades. THE VLT AND PARANAL In order to find the best site for the VLT, ESO performed a thorough investigation of many possible mountain tops, both near La Silla and in Northern Chile. They showed

  12. Robotic Technologies for Surveying Habitats and Seeking Evidence of Life: Results from the 2004 Field Experiments of the "Life in the Atacama" Project

    Science.gov (United States)

    Wettergreen, D.; Cabrol, N.; Whittaker, W.; Diaz, G. Chong; Calderon, F.; Heys, S.; Jonak, D.; Lueders, A.; Moersch, J.; Pane, D.

    2005-01-01

    The Chilean Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. Evidence suggests that the interior of the Atacama is lifeless, yet where the desert meets the Pacific coastal range dessication-tolerant microorganisms are known to exist. The gradient of biodiversity and habitats in the Atacama's subregions remain unexplored and are the focus of the Life in the Atacama project. Our field investigation attempts to bring further scientific understanding of the Atacama as a habitat for life through the creation of robotic astrobiology. This involves capabilities for autonomously traversing hundreds of kilometers while deploying sensors to survey the varying geologic and biologic properties of the environment, Fig. 1. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain in search of the habitats in which life can survive, or may have in the past.

  13. Accumulation of impact markers in desert wetlands and implications for the Younger Dryas impact hypothesis

    Science.gov (United States)

    Pigati, Jeffrey S.; Latorre, Claudio; Rech, Jason A.; Betancourt, Julio L.; Martinez, Katherine E.; Budahn, James R.

    2012-01-01

    The Younger Dryas impact hypothesis contends that an extraterrestrial object exploded over North America at 12.9 ka, initiating the Younger Dryas cold event, the extinction of many North American megafauna, and the demise of the Clovis archeological culture. Although the exact nature and location of the proposed impact or explosion remain unclear, alleged evidence for the fallout comes from multiple sites across North America and a site in Belgium. At 6 of the 10 original sites (excluding the Carolina Bays), elevated concentrations of various "impact markers" were found in association with black mats that date to the onset of the Younger Dryas. Black mats are common features in paleowetland deposits and typically represent shallow marsh environments. In this study, we investigated black mats ranging in age from approximately 6 to more than 40 ka in the southwestern United States and the Atacama Desert of northern Chile. At 10 of 13 sites, we found elevated concentrations of iridium in bulk and magnetic sediments, magnetic spherules, and/or titanomagnetite grains within or at the base of black mats, regardless of their age or location, suggesting that elevated concentrations of these markers arise from processes common to wetland systems, and not a catastrophic extraterrestrial impact event.

  14. OVERVIEW OF THE ATACAMA COSMOLOGY TELESCOPE: RECEIVER, INSTRUMENTATION, AND TELESCOPE SYSTEMS

    International Nuclear Information System (INIS)

    The Atacama Cosmology Telescope was designed to measure small-scale anisotropies in the cosmic microwave background and detect galaxy clusters through the Sunyaev-Zel'dovich effect. The instrument is located on Cerro Toco in the Atacama Desert, at an altitude of 5190 m. A 6 m off-axis Gregorian telescope feeds a new type of cryogenic receiver, the Millimeter Bolometer Array Camera. The receiver features three 1000-element arrays of transition-edge sensor bolometers for observations at 148 GHz, 218 GHz, and 277 GHz. Each detector array is fed by free space millimeter-wave optics. Each frequency band has a field of view of approximately 22' x 26'. The telescope was commissioned in 2007 and has completed its third year of operations. We discuss the major components of the telescope, camera, and related systems, and summarize the instrument performance.

  15. Isotope hydrology in northern Chile

    International Nuclear Information System (INIS)

    Environmental isotope analyses were done on samples from aquifers in the Pampa del Tamarugal and the Salar de Atacama drainage basin in northern Chile. In the Pampa it is possible to delineate individual groundwater bodies on the basis of their 18O and deuterium contents and, in some cases, to relate these to specific recharge areas. A marked displacement from the meteoric water line indicates that river recharge is an important mechanism for groundwater renewal. Groundwater ages appear high at distance from the Andes and much of the water found in the Pampa may have to be treated as a non-renewable resource. The groundwaters, springs and rivers of the Salar de Atacama drainage basin vary between -6.09 and -8.06%. No difference between the different waters can be recognized and an evaporative isotope enrichment indicates that also here river recharge is an important process. Some groundwaters adjacent to the Salar are very salty but 18O and deuterium data show that these waters are not refluxed brines but simply salty freshwater. The 14C contents in groundwaters and springs are very low but their delta13C values are high. It is concluded that this is probably due to the uptake of volcanic CO2. 14C age dating is thus not possible unless the delta13C values of all possible carbon sources can be defined and the geochemical evolution of the groundwaters is better understood. (author)

  16. Segmentación, cinemática y cronología relativa de la deformación tardía de la Falla Salar del Carmen, Sistema de Fallas de Atacama, (23°40'S), norte de Chile

    OpenAIRE

    Gabriel González; Daniel Carrizo

    2003-01-01

    La Falla Salar del Carmen es una de las estructuras principales del Sistema de Fallas de Atacama, que se ubica al este de Antofagasta en el borde oriental de Sierra del Ancla. El evento de deformación más reciente a lo largo de esta falla dio origen a la formación de siete segmentos de falla de orientación submeridiana, cuya longitud promedio es de 8 km. Los segmentos muestran un escalonamiento lateral izquierdo, cuyos extremos están ligados por fallas de transferencia. La deformación formó e...

  17. Late Pleistocene glaciations of the arid subtropical Andes and new results from the Chajnantor Plateau, northern Chile

    Science.gov (United States)

    Ward, Dylan J.; Cesta, Jason M.; Galewsky, Joseph; Sagredo, Esteban

    2015-11-01

    The spatiotemporal pattern of glaciation along the Andes Mountains is an important proxy record reflecting the varying influence of global and regional circulation features on South American climate. However, the timing and extent of glaciation in key parts of the orogen, particularly the deglaciated arid Andes, are poorly constrained. We present new cosmogenic 10Be and 36Cl exposure ages for glacial features on and near the Chajnantor Plateau (23 °S). The new dates, although scattered due to cosmogenic inheritance, imply that the most recent extensive glacial occupation ended before or during the global Last Glacial Maximum (LGM). We discuss this new record in the context of published glacial chronologies from glacial features in Peru, Bolivia, and northern Chile rescaled using the latest cosmogenic 10Be production rate calibration for the tropical Andes. The results imply regionally synchronous moraine stabilization ca. 25-40 ka, 15-17 ka, and 12-14 ka, with the youngest of these moraines absent in records south of ˜20 °S, including in our new Chajnantor area chronology. This spatial pattern implicates easterly moisture in generating sufficient snowfall to glaciate the driest parts of the Andes, while allowing a role for westerly moisture, possibly modulated by the migration of the Southern Westerly Wind belt, in the regions near and south of the Atacama Desert.

  18. Atacama Compact Array Correlator for Atacama Large Millimeter/submillimeter Array

    OpenAIRE

    Okumura, Sachiko K.; Chikada, Yoshihiro; Kamazaki, Takeshi; Okuda, Takeshi; Kurono, Yasutaka; Iguchi, Satoru

    2011-01-01

    We have developed a FX-architecture digital spectro-correlator, Atacama Compact Array Correlator for the Atacama Large Millimeter/submillimeter Array. The ACA Correlator processes four pairs of dual polarization signals, whose bandwidth is 2 GHz, from up to sixteen antennas, and calculates auto- and cross-correlation spectra including cross-polarization in all combinations of sixteen antennas. We report the detailed design of the correlator and the verification results of the correlator hardw...

  19. EL NORTE GRANDE DE CHILE: LA DEFINICIÓN HISTÓRICA DE SUS LÍMITES, ZONAS Y LÍNEAS DE FRONTERAS, Y LA IMPORTANCIA DE LAS CIUDADES COMO GEOSÍMBOLOS FRONTERIZOS

    Directory of Open Access Journals (Sweden)

    SERGIO GONZÁLEZ

    2011-05-01

    Full Text Available Resumen Este artículo analiza el desarrollo histórico del Norte Grande de Chile durante el siglo diecinueve y el primer tercio del siglo veinte, con sus diversas zonas de fronteras y límites fronterizos respectivos, donde ciertos geosímbolos han tenido un papel muy relevante como demarcadores. Sin embargo, considera la urbanización de la frontera como un proceso clave en la reproducción social y cultural del estado-nación. Destaca en ese proceso de urbanización del Norte Grande de Chile, la importancia del desierto de Atacama y de algunas ciudades como geosímbolos, analiza los casos de Antofagasta, Iquique y Arica. También discute teóricamente la diferencia entre límite fronterizo y línea de frontera, al primer concepto lo asocia a una problemática propia del siglo diecinueve y veinte, donde la frontera es un rígido demarcador de la otredad y, el segundo concepto, lo asocia al fenómeno de la globalización y a la posibilidad de construir en las fronteras urbanizadas alianzas estratégicas y regiones asociativas transfronterizas. Conceptos clave: zonas de fronteras, límites fronterizos, líneas de frontera, geosímbolos, transfrontera. Abstract This article analyzes the historical development of the Big North of Chile during the 19th century and the first third of the 20th century, with its own various border areas and frontier boundaries, where certain geosymbols have had a very relevant role demarcating. However, it considers the urbanization of the frontier as a key process in the social and cultural reproduction of the nation-state. It emphasizes in that process of urbanization of the Big North of Chile, the importance of the Atacama Desert and some cities as geosymbols, it analyzes the cases of Antofagasta, Iquique and Arica. It also theoretically discusses the difference between the frontier boundary and border line, it associates the first concept with problematic issues typical of the 19th and 20th centuries, where the

  20. The giant coastal landslides of Northern Chile: Tectonic and climate interactions on a classic convergent plate margin

    Science.gov (United States)

    Mather, Anne E.; Hartley, Adrian J.; Griffiths, James S.

    2014-02-01

    Documented for the first time are an extensive suite of late Neogene giant terrestrial coastal landslides along the classic convergent margin of western South America (18° to 24° south). These are remarkable in terms of their unusual abundance and atypical setting, such failures previously being linked with oceanic volcanic edifices or over-steepened glaciated coastlines. Located within the hyper-arid Coastal Cordillera of the Atacama Desert of Northern Chile we report the presence of more than 60 individual large-scale landslides with individual volumes up to 9 km3 developed over a horizontal coastline distance of some 650 km. These landslides were emplaced as a combination of rock avalanches and multiple rotational failures. The majority terminated directly into the Pacific - likely generating significant tsunami hazard to the Chilean and south Peruvian coastline in a region which is today considered to be part of a notorious seismic gap. The proliferation and scale of these Late Neogene giant landslides in this actively uplifting, hyperarid terrain suggests they are the main geomorphic agent for relief reduction, probably triggered by megathrust earthquakes and potentially providing a unique palaeoseismic archive. The temporal and spatial distribution of these giant landslides corresponds with a period of surface steepening of the forearc wedge in the Central Andes and south to north differential uplift associated with factors such as aseismic ridge subduction. The resulting surface gradient increases, combined with the persistent climatic aridity of the region, have served to limit effective relief-reducing geomorphic processes in this oversteepened terrain to large-scale landsliding. The phenomena documented here geospatially link previously recognised large-scale slope failures from the off-shore environment and higher altitude areas of the Andean forearc, suggesting that large-scale landsliding is capable of transferring sediment on a regional scale to the

  1. Detecting leaf pulvinar movements on NDVI time series of desert trees: a new approach for water stress detection.

    Directory of Open Access Journals (Sweden)

    Roberto O Chávez

    Full Text Available Heliotropic leaf movement or leaf 'solar tracking' occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI, should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern Chile, we studied seasonal and diurnal variations of MODIS and Landsat NDVI time series of plantation stands of the endemic species Prosopis tamarugo Phil., subject to different levels of groundwater depletion. As solar irradiation increased during the day and also during the summer, the paraheliotropic leaves of Tamarugo moved to an erectophile position (parallel to the sun rays making the NDVI signal to drop. This way, Tamarugo stands with no water stress showed a positive NDVI difference between morning and midday (ΔNDVI mo-mi and between winter and summer (ΔNDVI W-S. In this paper, we showed that the ΔNDVI mo-mi of Tamarugo stands can be detected using MODIS Terra and Aqua images, and the ΔNDVI W-S using Landsat or MODIS Terra images. Because pulvinar movement is triggered by changes in cell turgor, the effects of water stress caused by groundwater depletion can be assessed and monitored using ΔNDVI mo-mi and ΔNDVI W-S. For an 11-year time series without rainfall events, Landsat ΔNDVI W-S of Tamarugo stands showed a positive linear relationship with cumulative groundwater depletion. We conclude that both ΔNDVI mo-mi and ΔNDVI W-S have potential to detect early water stress of paraheliotropic vegetation.

  2. Systematics of Natural Perchlorate in Precipitation, Soils, and Plants at the Amargosa Desert Research Site, Nye County, Nevada

    Science.gov (United States)

    Andraski, B. J.; Stonestrom, D. A.; Jackson, W. A.; Rajagopalan, S.; Taylor, E. M.

    2007-12-01

    Naturally occurring perchlorate is known to be associated with nitrate deposits of the hyperarid Atacama Desert in Chile, and recent large-scale sampling has identified a substantial reservoir (up to 1 kg/ha) of natural perchlorate in diverse unsaturated zones of the arid and semiarid Southwestern United States (Rao et al., 2007, ES&T, DOI: 10.1021/es062853i). The objective of the Amargosa Desert work is to develop a better understanding of the deposition, accumulation, and biological cycling of perchlorate in arid environments. Occurrence of perchlorate was evaluated by sampling shallow soil profiles up to 3 m in depth at four different locations and at two different time periods, and by sampling dominant plant species growing near the subsurface profiles. Deposition of perchlorate was evaluated by analyzing both bulk deposition (precipitation plus dry fall, collected under oil) collected on site and wet deposition samples collected by the National Atmospheric Deposition program at a nearby site. Soil samples and atmospheric-deposition samples were tested for both perchlorate (ClO4- ) and major anions. Perchlorate concentrations (0.2-20 µg/kg) were variable with depth in soil profiles and generally correlated most highly with chloride (Cl-) and nitrate (NO3-), although the intensity of these relations differed among profiles. Plant concentrations were generally above 1 mg/kg, suggesting ClO4- accumulation. Concentrations of ClO4- were generally much greater in total deposition than wet deposition samples, indicating a substantial dryfall component of meteoric deposition. This presentation will present the mass distribution and variability of perchlorate in bulk deposition, soils, and plants. Reasons for observed relations between subsurface concentrations of perchlorate and other anions will be explored.

  3. Detecting leaf pulvinar movements on NDVI time series of desert trees: A new approach for water stress detection

    OpenAIRE

    Chávez Oyanadel, R.O.; Clevers, J G P W; Verbesselt, J.; Naulin, P.; M. Herold

    2014-01-01

    Heliotropic leaf movement or leaf ‘solar tracking’ occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI), should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern...

  4. Detecting Leaf Pulvinar Movements on NDVI Time Series of Desert Trees: A New Approach for Water Stress Detection

    OpenAIRE

    2014-01-01

    Heliotropic leaf movement or leaf ‘solar tracking’ occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI), should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern...

  5. Assessing water stress of desert Tamarugo trees using in situ data and very high spatial resolution remote sensing

    NARCIS (Netherlands)

    Chávez Oyanadel, R.O.; Clevers, J.G.P.W.; Herold, M.; Acevedo, E.; Ortiz, M.

    2013-01-01

    The hyper-arid Atacama Desert is one of the most extreme environments for life and only few species have evolved to survive its aridness. One such species is the tree Prosopis tamarugo Phil. Because Tamarugo completely depends on groundwater, it is being threatened by the high water demand from the

  6. Occurrence of arsenic species in algae and freshwater plants of an extreme arid region in northern Chile, the Loa River Basin.

    Science.gov (United States)

    Pell, Albert; Márquez, Anna; López-Sánchez, José Fermín; Rubio, Roser; Barbero, Mercedes; Stegen, Susana; Queirolo, Fabrizio; Díaz-Palma, Paula

    2013-01-01

    This study reports data on arsenic speciation in two green algae species (Cladophora sp. and Chara sp.) and in five aquatic plants (Azolla sp., Myriophyllum aquaticum, Phylloscirpus cf. desserticola, Potamogeton pectinatus, Ruppia filifolia and Zannichellia palustris) from the Loa River Basin in the Atacama Desert (northern Chile). Arsenic content was measured by Mass spectrometry coupled with Inductively Coupled Plasma (ICP-MS), after acidic digestion. Liquid chromatography coupled to ICP-MS was used for arsenic speciation, using both anionic and cationic chromatographic exchange systems. Inorganic arsenic compounds were the main arsenic species measured in all samples. The main arsenic species in the extracts of freshwater algae and plants were arsenite and arsenate, whereas glycerol-arsenosugar (gly-sug), dimethylarsinic acid (DMA) and methylarsonic acid (MA) were present only as minor constituents. Of the samples studied, algae species accumulated more arsenic than aquatic plants. Total arsenic content ranged from 182 to 11100 and from 20 to 248 mg As kg(-1) (d.w.) in algae and freshwater plants, respectively. In comparison with As concentration in water samples, there was hyper-accumulation (>0.1% d.w.) in Cladophora sp. PMID:22981629

  7. Environmental controls on methanogen viability in the hydrothermal waters of the El Tatio geyser field, Chile.

    Science.gov (United States)

    Franks, M. A.; Bennett, P. C.; Omelon, C.; Engel, A. S.

    2007-12-01

    At the El Tatio geyser field, a unique hydrothermal site located in the Andes Mountains in Chile, methanogenic archaea were found in only two of the hundreds of hydrothermal features. Reported here is an investigation into the environmental and geochemical controls on the distribution of methanogenic archaea. Located in the hyper- arid Atacama Desert, El Tatio waters are characterized by high salinity (95-175mM), Na-Cl type waters and circum-neutral pH (6.5-7), with very low inorganic carbon (0.1-0.5 mM TIC), but very high concentrations of As and Sb (300-700 uM As, 10-30uM Sb). Extensive bacterial mats thrive in most of the shallow run-off streams originating from hydrothermal features. In order to determine geochemical controls on methanogen populations, major and trace elements, including As and Sb speciation and concentrations, were determined using IC and HPLC-ICP-MS methods. The structure of microbial communities was analyzed using MPN enumeration of methanogens, culturing, and phylogenetic analysis using molecular techniques. Here, as in many hydrothermal regions, temperature and geochemical gradients influence the microbial ecology. Results from MPN enumeration indicate methanogen populations are dominated by H2-utilizing (carbonate reducing) archaea at both of the sites, with some acetate-oxidizing archaea present. These sites contain comparatively high DIC concentrations; however, it is unclear whether this is a control or a product of methanogenic archaea. Water quality analyses also show a strong correlation between antimony concentrations and the presence of methanogens; methanogenic archaea being present only at sites with 17 uM Sb concentrations or less.

  8. Listening carefully: unique observations of harmonic tremor at Lascar volcano, Chile

    Directory of Open Access Journals (Sweden)

    M. Hellweg

    1999-06-01

    Full Text Available During the deployment of Proyecto de Investigación Sismológica de la Cordillera Occidental 94 (PISCO'94 in the Atacama Desert of Northern Chile, a broadband seismic station and a network of three short-period three-component stations were installed around the active volcano Lascar. The resulting data set includes a sequence of harmonic tremor with a fundamental at about 0.63 Hz and up to 30 overtones lasting 18 h. Power spectra and spectrograms of Lascar's harmonic tremor from the various stations demonstrate that the frequencies recorded cannot be explained as path effects, and must therefore be attributed to mechanisms at or near the source. The polarization of the wavefield cannot simply be explained as the propagation of any of the classical types of seismic waves, thus we apply new methods to the data to investigate the narrowband signals of the harmonic peaks. While the amplitude characteristics of these signals cannot be correlated across the network, frequency characteristics of the harmonic wavefield are consistent across stations and components. The tremor's fundamental frequency changes at the same time at all stations, indicating that such changes must be caused at the source. In addition, a change in the frequency of the fundamental, f1, is reflected exactly in the frequencies of the overtones, nf1 and peak-broadening in the power spectrum is the result of shifts in the fundamental frequency. It is therefore unlikely that the overtones are produced as resonances. This spectral behavior indicates rather that the source is some resonance at a single frequency within the magma, magma/gas or gas parts of the volcano whose amplitude exceeds the range for which the assumptions of linear acoustics are valid.

  9. Caso exitoso eficiencia energética: Hotel Explora: San Pedro de Atacama

    OpenAIRE

    Banco Interamericano de Desarrollo (BID); Fundación Chile

    2012-01-01

    Este documento presenta el caso exitoso de mejora de la eficiencia energética en el Hotel Explora en San Pedro de Atacama. La empresa, mediante los aportes del BID-FOMIN - a través del "Programa de promoción de oportunidades de energías limpias" - ejecutado por Fundación Chile, logró ahorros anuales de 60 millones, un retorno de la inversión de 1 a 3 años, y un ahorro de emisiones de CO2 de 140 toneladas al año. En el documento se explican los pormenores financieros y técnicos del proyecto....

  10. Science with the Atacama Large Millimeter Array A New Era for Astrophysics

    CERN Document Server

    Bachiller, Rafael

    2008-01-01

    Currently under construction in the Andean Altiplano, Northern Chile, the Atacama Large Millimeter Array (ALMA) is the most ambitious astronomy facility under construction. ALMA is a radio interferometer composed of 54 antennas of 12 m diameter, and twelve 7 m antennas with about 6600 square meters of total collecting area. Initially covering the most interesting spectral wavelength ranges from 3 to 0.3 mm, ALMA will be a revolutionary telescope aimed to unveil the details of star and planet formation and to provide astronomy with the first exhaustive view of the dark and youngest objects of the Universe. This book describes the enormous capabilities of ALMA, the state of the project, and most notably the scientific prospects with such a unique facility. The book includes comprehensive reviews and recent results on most hot topics of modern Astronomy (the formation and evolution of galaxies, the physics and chemistry of the interstellar medium, and the processes of star and planet formation) with prospects to...

  11. The First Multichroic Polarimeter Array on the Atacama Cosmology Telescope: Characterization and Performance

    Science.gov (United States)

    Ho, S. P.; Pappas, C. G.; Austermann, J.; Beall, J. A.; Becker, D.; Choi, S. K.; Datta, R.; Duff, S. M.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Henderson, S. W.; Hilton, G. C.; Hubmayr, J.; Koopman, B. J.; Lanen, J. V.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Niraula, P.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Ward, J. T.; Wollack, E. J.; Vavagiakis, E. M.

    2016-03-01

    The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive receiver for the 6-m Atacama Cosmology Telescope (ACT) and measures the small angular scale polarization anisotropies in the cosmic microwave background (CMB). The full focal plane is composed of three detector arrays, containing over 3000 transition edge sensors (TES detectors) in total. The first two detector arrays, observing at 146 GHz, were deployed in 2013 and 2014, respectively. The third and final array is composed of multichroic pixels sensitive to both 90 and 146 GHz and saw first light in February 2015. Fabricated at NIST, this dichroic array consists of 255 pixels, with a total of 1020 polarization sensitive bolometers and is coupled to the telescope with a monolithic array of broad-band silicon feedhorns. The detectors are read out using time-division SQUID multiplexing and cooled by a dilution refrigerator at 110 mK. We present an overview of the assembly and characterization of this multichroic array in the lab, and the initial detector performance in Chile. The detector array has a TES detector electrical yield of 85 %, a total array sensitivity of less than 10 \\upmu K√{s} , and detector time constants and saturation powers suitable for ACT CMB observations.

  12. ANIR : Atacama Near-Infrared Camera for the 1.0-m miniTAO Telescope

    CERN Document Server

    Konishi, Masahiro; Tateuchi, Ken; Takahashi, Hidenori; Kitagawa, Yutaro; Kato, Natsuko; Sako, Shigeyuki; Uchimoto, Yuka K; Toshikawa, Koji; Ohsawa, Ryou; Yamamuro, Tomoyasu; Asano, Kentaro; Ita, Yoshifusa; Kamizuka, Takafumi; Komugi, Shinya; Koshida, Shintaro; Manabe, Sho; Matsunaga, Noriyuki; Minezaki, Takeo; Morokuma, Tomoki; Nakashima, Asami; Takagi, Toshinobu; Tanabé, Toshihiko; Uchiyama, Mizuho; Aoki, Tsutomu; Doi, Mamoru; Handa, Toshihiro; Kato, Daisuke; Kawara, Kimiaki; Kohno, Kotaro; Miyata, Takashi; Nakamura, Tomohiko; Okada, Kazushi; Soyano, Takao; Tamura, Yoichi; Tanaka, Masuo; Tarusawa, Ken'ichi; Yoshii, Yuzuru

    2015-01-01

    We have developed a near-infrared camera called ANIR (Atacama Near-InfraRed camera) for the University of Tokyo Atacama Observatory 1.0m telescope (miniTAO) installed at the summit of Cerro Chajnantor (5640 m above sea level) in northern Chile. The camera provides a field of view of 5'.1 $\\times$ 5'.1 with a spatial resolution of 0".298 /pixel in the wavelength range of 0.95 to 2.4 $\\mu$m. Taking advantage of the dry site, the camera is capable of hydrogen Paschen-$\\alpha$ (Pa$\\alpha$, $\\lambda=$1.8751 $\\mu$m in air) narrow-band imaging observations, at which wavelength ground-based observations have been quite difficult due to deep atmospheric absorption mainly from water vapor. We have been successfully obtaining Pa$\\alpha$ images of Galactic objects and nearby galaxies since the first-light observation in 2009 with ANIR. The throughputs at the narrow-band filters ($N1875$, $N191$) including the atmospheric absorption show larger dispersion (~10%) than those at broad-band filters (a few %), indicating that ...

  13. Desert Cyanobacteria under simulated space and Martian conditions

    Science.gov (United States)

    Billi, D.; Ghelardini, P.; Onofri, S.; Cockell, C. S.; Rabbow, E.; Horneck, G.

    2008-09-01

    The environment in space and on planets such as Mars, can be lethal to living organisms and high levels of tolerance to desiccation, cold and radiation are needed for survival: rock-inhabiting cyanobacteria belonging to the genus Chroococcidiopsis can fulfil these requirements [1]. These cyanobacteria constantly appear in the most extreme and dry habitats on Earth, including the McMurdo Dry Valleys (Antarctica) and the Atacama Desert (Chile), which are considered the closest terrestrial analogs of two Mars environmental extremes: cold and aridity. In their natural environment, these cyanobacteria occupy the last refuges for life inside porous rocks or at the stone-soil interfaces, where they survive in a dry, dormant state for prolonged periods. How desert strains of Chroococcidiopsis can dry without dying is only partially understood, even though experimental evidences support the existence of an interplay between mechanisms to avoid (or limit) DNA damage and repair it: i) desert strains of Chroococcidiopsis mend genome fragmentation induced by ionizing radiation [2]; ii) desiccation-survivors protect their genome from complete fragmentation; iii) in the dry state they show a survival to an unattenuated Martian UV flux greater than that of Bacillus subtilis spores [3], and even though they die following atmospheric entry after having orbited the Earth for 16 days [4], they survive to simulated shock pressures up to 10 GPa [5]. Recently additional experiments were carried out at the German Aerospace Center (DLR) of Cologne (Germany) in order to identify suitable biomarkers to investigate the survival of Chroococcidiopsis cells present in lichen-dominated communities, in view of their direct and long term space exposition on the International Space Station (ISS) in the framework of the LIchens and Fungi Experiments (LIFE, EXPOSEEuTEF, ESA). Multilayers of dried cells of strains CCMEE 134 (Beacon Valley, Antarctica), and CCMEE 123 (costal desert, Chile ), shielded by

  14. Parque Astron\\'omico de Atacama: An ideal site for millimeter, sub-millimeter, and mid-infrared astronomy

    CERN Document Server

    Bustos, Ricardo; Otárola, Angel; Nagar, Neil

    2014-01-01

    The area of Chajnantor, at more than 5000 meters altitude in northern Chile, offers unique atmospheric and operational conditions which arguably make it the best site in the world for millimeter, sub-millimeter, and mid-infrared observatories. Long-term monitoring of the precipitable water vapor (PWV) column on the Chajnantor plateau has shown its extreme dryness with annual median values of 1.1 mm. Simultaneous measurements of PWV on the Chajnantor plateau (5050 m) and on Cerro Chajnantor (5612 m) show that the latter is around 36% lower under normal atmospheric conditions and up to 80% lower than the plateau in the presence of temperature inversion layers. Recently, the Government of Chile has consolidated the creation of the Parque Astron\\'omico de Atacama (Atacama Astronomical Park), an initiative of the Chilean Commission for Science and Technology (CONICYT). This new Parque offers an opportunity for national and international projects to settle within its boundaries, gain access to an extremely dry site...

  15. Parque Astronómico de Atacama: An Ideal Site for Millimeter, Submillimeter, and Mid-Infrared Astronomy

    Science.gov (United States)

    Bustos, R.; Rubio, M.; Otárola, A.; Nagar, N.

    2014-12-01

    The area of Chajnantor, at more than 5000 m altitude in northern Chile, offers unique atmospheric and operational conditions which arguably make it the best site in the world for millimeter, submillimeter, and mid-infrared observatories. Long-term monitoring of the precipitable water vapor (PWV) column on the Chajnantor plateau has shown its extreme dryness with annual median values of 1.1 mm. Simultaneous measurements of PWV on the Chajnantor plateau (5050 m) and on Cerro Chajnantor (5612 m) show that the latter is around 36% lower under normal atmospheric conditions and up to 80% lower than the plateau in the presence of temperature inversion layers. Recently, the Government of Chile has consolidated the creation of the Parque Astronómico de Atacama (Atacama Astronomical Park), an initiative of the Chilean Commission for Science and Technology (CONICYT). This new park offers an opportunity for national and international projects to settle within its boundaries, gain access to an extremely dry site that is suitable for observations over a broad spectral range, especially in the millimeter to mid-infrared wavelengths, and benefit from operational and logistical support within a secure legal framework.

  16. Paleoenvironmental change in central Chile as inferred from OSL dating of ancient coastal sand dunes

    Science.gov (United States)

    Andrade, Belisario; Garcia, Juan L.; Lüthgens, Christopher; Fiebig, Markus

    2013-04-01

    To present day, the climatic and geographic expression of glacials and interglacials in the semiarid coast of central Chile remains unclear. The lack of well dated paleoclimatic records has up to now precluded firm conclusions whether maximum glacials evident in the Andes mountain range probably coincide with wetter (e.g., pluvials) or drier conditions at the coast. The natural region locally known as "Norte Chico" represents a transitional semiarid area between the extreme Atacama Desert to the North and the wetter, Mediterranean-like type of climate, to the South. In this semiarid region of Chile several generations of eolian sand dunes, some of them separated by paleosoils, have been preserved. In addition to the occurrence of paleosoils, thick debris flow deposits in some places overly ancient dune bodies, likely indicating significant environmental changes during the formation of these archives. However, the exact timing of these processes within the mid to late Pleistocene and Holocene is still unclear. A key aspect is that some of the ancient dunes are recently hanging above rocky coastlines, where no supply of sand exists today, likely implying their formation during a lower than present, probably glacio-eustatically induced sea level. The location of the research area in a key mid-latitude region of the eastern Pacific in combination with the preserved landform record offers a chance to reconstruct climatic shifts during the Quaternary by studying the variability of morphogenetic conditions throughout time, in order to promote knowledge about possible forcing factors driving climatic variability. Within this pilot study, samples for optically stimulated luminescence (OSL) dating were taken from three different stratigraphic sections that denote a complex environmental variability as indicated by paleosoils and debris flow units intercalated in ancient sand dunes. First dating results inferred from OSL measurements using a post-IR IRSL (pIRIR) protocol for

  17. Miracles in a Desert

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    People find new ways to harness the Ulan Buh Desert Going into the heart of the Ulan Buh Desert in north China’s Inner Mongolia Autonomous Region, one will be astonished by a large stretch of water.

  18. The Atacama Large Millimeter/submillimeter Array: A New Window on the Universe

    Science.gov (United States)

    Beasley, Anthony J.

    2013-06-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is the largest ground-based global astronomy endeavor in history. Composed of 66 high-precision antennas located on an excellent site at 5000m+ elevation on the Chajnantor plateau in northern Chile, ALMA is delivering the astronomy community orders of magnitude improvements in millimeter-wavelength sensitivity, frequency coverage, resolution, imaging, and spectral capabilities, impacting most fields of astrophysics and opening multiple new scientific frontiers. ALMA’s capabilities span wavelengths from 9.6 to 0.3 mm (31-950 GHz), a key part of the electromagnetic spectrum for observing the first stars and galaxies, directly imaging planetary formation, and studying the energy output from supermassive black holes in starburst galaxies. ALMA’s inauguration on 13 March 2013 marked the Project’s transition to operation as a fully-fledged Observatory. This session will review ALMA’s origins and history, current technical capabilities, and describe its primary scientific goals. Innovative aspects of its design, construction, operation, and governance will be highlighted, including the key roles of the North American ALMA Science Center at the National Radio Astronomy Observatory in Charlottesville, Virginia and the Joint ALMA Observatory in Chile. Development of the state-of-the-art technologies that are enabling the highest impact science will be described. Science operations were initiated 30 September 2011, and research results will be presented from both the Cycle 0 and Cycle 1 Early Science opportunities. This session will conclude with the vision for the Development Program that will maintain ALMA’s capabilities at the forefront of modern astronomy. ALMA is a partnership of North America, Europe, and East Asia in cooperation with the Republic of Chile. ALMA is funded in North America by the U.S. National Science Foundation, in cooperation with the National Research Council of Canada, and the National

  19. Solar Simulations for the Atacama Large Millimeter Observatory Network

    OpenAIRE

    Wedemeyer, Sven; Bastian, Tim; Brajsa, Roman; Barta, Miroslav; Shimojo, Masumi

    2015-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) will be a valuable tool for observing the chromosphere of our Sun at (sub-)millimeter wavelengths at high spatial, temporal and spectral resolution and as such has great potential to address long-standing scientific questions in solar physics. In order to make the best use of this scientific opportunity, the Solar Simulations for the Atacama Large Millimeter Observatory Network has been initiated. A key goal of this international collabo...

  20. Modified Desert Cooler (MDC

    Directory of Open Access Journals (Sweden)

    CHANDRAKANT B. KOTHARE,

    2011-04-01

    Full Text Available “Modified Desert Cooler (MDC” as the name suggest that it is the modification of the conventional cooler. It is the Air Conditioner cum refrigerator for people who cannot afford costly equipments like air conditioner, refrigerator and other such appliances. It cools the air more than the conventional Desert cooler. The modified desert cooler is developed for providing better cooling effect than conventional desert cooler. It also provides cold-pure water for drinking purpose comparatively at low cost than Refrigerator with the help of modifies Matka attached with it. It also decreased moisture content of the air coming through desert cooler upto someextent. The MDC consists of a desert cooler with storage box, two concentric simple small size earthen pot known as modify Matka, a purifier, humidity controller and connecting tubes or pipes. Storage box provided in the desert cooler can be used to store regular food items, vegetables, fruits etc.

  1. Digital Spectro-Correlator System for the Atacama Compact Array of the Atacama Large Millimeter/submillimeter Array

    OpenAIRE

    Kamazaki, T.; Okumura, S. K.; Chikada, Y.; Okuda, T; Kurono, Y.; Iguchi, S.; Mitsuishi, S.; Murakami, Y.; Nishimuta, N.; Mita, H.; Sano, R.

    2011-01-01

    We have developed an FX-architecture digital spectro-correlator for the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array. The correlator is able to simultaneously process four pairs of dual polarization signals with the bandwidth of 2 GHz, which are received by up to sixteen antennas. It can calculate auto- and cross-correlation spectra including cross-polarization in all combinations of all the antennas, and output correlation spectra with flexible spectral con...

  2. A drone flight over ESO’s experimental sites in Chile

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    Paola Catapano, a member of CERN’s Communication Group, and Mike Struik, a member of the TE Department, were invited to visit ESO’s experimental sites – the ALMA observatory and the Very Large Telescope in Paranal, Chile. Enjoy some of the beautiful images they sent to the Bulletin.   Image courtesy Paola Catapano and Mike Struik. The 66 radio astronomy antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) observatory at 5,000 m altitude on the Chajnantor highland in Chile. The ALMA array specialises in the cold, invisible Universe, catching radiation from millimetre and submillimetre radiowaves night and day. ALMA is an international partnership between the European Southern Observatory (ESO), the US National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan, together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile.   Image cour...

  3. Measurement of SO2 and BrO at Lastarria, Lascar, and Salar de Atacama

    Science.gov (United States)

    Dinger, Florian; Osorio, Matias; Gliß, Jonas; Lübcke, Peter; Bobrowski, Nicole; Platt, Ulich; Frins, Erna; Wagner, Thomas

    2015-04-01

    In November 2014 the 12th CCVG (Commission of the Chemistry of Volcanic Gases) gas workshop took place in Northern Chile. Subject of the field trips were Lastarria (25°10' S, 68°30' W) and Lascar (23°22' S, 67°43' W), both stratovolcanoes with a height of 5700 and 5600 a.s.l., respectively. One of the goals was to investigate the SO2 and BrO emissions of these volcanoes by remote-sensing using Multi-AXial Differential Optical Absorption Spectroscopy (MAX-DOAS). The used 'mini MAX-DOAS' instrument measures scattered solar UV radiation recording spectra within a wavelength range of 294-437 nm and with a spectral resolution of 0.9 nm. The instrument took spectra sequentially at various elevation angles scanning the sky from horizon to zenith. The scanning geometry was adapted to each measurement location. At Lastarria volcano we observed SO2 slant column densities (SCDs) in the order of 1018 molecules/cm2 and BrO SCDs up to 5 - 1013 molecules/cm2. At Lascar volcano we observed SO2 SCDs up to 4 - 1017 molecules/cm2 but no significant BrO absorption features (in a preliminary evaluation). We will present SO2 fluxes and upper detection limits of BrO, and present maxima BrO/SO2 ratios of Lastarria and Lascar. Those ratios will be compared to BrO/SO2 ratios of other - previously studied - Andean volcanoes (e.g. Villarica). Furthermore, we measured the SO2 and BrO SCDs above the Salar de Atacama (23°30' S, 68°15' W), a salt pan with an area of 3000 km2. Spectra were taken in a direction where the Salar de Atacama has an extension of about 50 km and no other obvious emission sources were contributing to the SO2 and BrO absorption signals. At the Salar de Atacama we observed SO2 SCDs up to 2 - 1017 molecules/cm2 and BrO SCDs of up to 7 - 1013 molecules/cm2.

  4. Examining the life history of an individual from Solcor 3, San Pedro de Atacama: Combining bioarchaeology and archaeological chemistry

    International Nuclear Information System (INIS)

    Detailed life history information using multiple lines of evidence including the identification of geographic origins, health, and body use indicators, can be used to elucidate the complex process of acculturation in the San Pedro de Atacama oases of northern Chile during the Middle Horizon. This paper presents the results of bioarchaeological and archaeological chemical analyses of the skeletal remains of an adult male (tomb 50, catalog number 1948) from the cemetery of Solcor 3 (ca. AD 500-900). Strontium isotope ratios in human tooth enamel reveal information about where a person lived during their childhood, when enamel was being formed. Individual 1948 showed strontium isotope ratios decidedly outside the range of the local San Pedro de Atacama strontium isotope signature. Given these data implying that individual 1948 was originally from elsewhere, an examination of his health status, social role, and mortuary context provides insight into the treatment of foreigners in San Pedro de Atacama. Our data support the argument that individual 1948's foreign birth did not hinder his later assimilation into Atacameno society. He was buried in a local cemetery with a typical mortuary assemblage for a male of this time and no strong evidence of possible foreign origin. Skeletal indicators of diet and activity patterns do not distinguish individual 1948 from the local population, suggesting that his lifestyle was similar to that of other Atacamenos. Therefore, our analyses suggest that individual 1948's acculturation into Atacameno society during his adult life was nearly complete and he retained little to no indication of his probable foreign birth

  5. Salar de Atacama basin: A record of compressional tectonics in the central Andes since the mid-Cretaceous

    Science.gov (United States)

    Arriagada, Cesar; Cobbold, Peter R.; Roperch, Pierrick

    2006-02-01

    The Salar de Atacama basin lies in the inner fore arc of northern Chile. Topographically and structurally, it is a first-order feature of the central Andes. The sedimentary fill of the basin constrains the timing and extent of crustal deformation since the mid-Cretaceous. We have studied good exposures along the western edge of the basin and have correlated them with seismic reflection sections and data from an exploration well. Throughout most of its history, the basin developed in a foreland setting, during periods of thin-skinned and thick-skinned thrusting. Growth strata provide evidence for coeval sedimentation and thrust motions during mid-Cretaceous, Paleogene, and Neogene times. Pre-Neogene deformation was significant in the basin and in surounding areas of the early central Andes. Models that attempt to explain the current thickness of the central Andes should consider Late Cretaceous and Paleogene shortening, as well as the more obvious Neogene and Quaternary shortening.

  6. La tesis de título de Guillermo Ulriksen Becker (1952): Bases para la Planeación Regional del Norte Chico: Provincias de Atacama y Coquimbo. /Graduation Project (Thesis) of the architect William Ulriksen Becker (1952): Basis for Region Planning of the “Norte Chico”: Atacama and Coquimbo provinces.

    OpenAIRE

    Pávez Reyes, María Isabel

    2008-01-01

    Se presenta la tesis de título en planeamiento regional de Guillermo Ulriksen Becker (n.1905 – m. 1979) presentada en 1953 en la, entonces, “Facultad de Arquitectura” de la Universidad de Chile: Bases para la Planeación Regional del Norte Chico: Provincias de Atacama y Coquimb. Este estudio que constituye no sólo una radiografía del estado del desarrollo del Norte Chico hace cincuenta y cinco años, sino que también un señalamiento del potencial posible de desarrollar en la perspectiva del lar...

  7. Thermal Performance of Traditional and New Concept Houses in the Ancient Village of San Pedro De Atacama and Surroundings

    Directory of Open Access Journals (Sweden)

    Massimo Palme

    2014-05-01

    Full Text Available Earth, wood and others traditional materials are still used in house constructions in many regions of the world, especially in the Andes. San Pedro de Atacama, for example, is a small town where earth blocks (adobes and rammed earth (tapial are important ways to construct, an art passed on through generations. Energy properties of earth are very interesting: thermal conductivity is low; heat storage capacity is high; color is variable and can be used to absorb or to reject solar radiation. However, nowadays the government social dwelling service is proposing a different type of construction, which does not maintain any relation with the tradition. This paper presents simulation studies and monitoring of four different San Pedro houses, constructed by using different techniques and materials. Results can be used to discuss the thermal performance needed in desert climate and the reliability of social dwelling service houses, under construction at this time in the town.

  8. Tapetes microbianos del Salar de Llamará, norte de Chile Microbial mats from the Llamará salt flat, northern Chile

    OpenAIRE

    CECILIA DEMERGASSO; GUILLERMO CHONG; PEDRO GALLEGUILLOS; LORENA ESCUDERO; MAIRA MARTíNEZ-ALONSO; ISABEL ESTEVE

    2003-01-01

    Se estudiaron las comunidades estratificadas de microorganismos fotosintéticos que se encuentran en el Salar de Llamará ubicado en el desierto de Atacama, norte de Chile, mediante métodos microscópicos y espectrofotométricos. El espesor de la zona fótica de los tapetes descritos varió entre 8 y 30 mm lo cual podría atribuirse a la granulometría y la composición mineralógica de los sedimentos. Se diferencian tres tipos de tapetes. El primero con una única capa pigmentada de color verde; el seg...

  9. U-series dating of co-seismic gypsum and submarine paleoseismology of active faults in Northern Chile (23°S)

    Science.gov (United States)

    Vargas, Gabriel; Palacios, Carlos; Reich, Martin; Luo, Shangde; Shen, Chuan-Chou; González, Gabriel; Wu, Yi-Chen

    2011-01-01

    The convergence of the Nazca and South American plates along the subduction margin of the central Andes results in large subduction earthquakes and tectonic activity along major fault systems. Despite its relevance, the paleoseismic record of this region is scarce, hampering our understanding about the relationship between the Andes building and earthquake occurrence. In this study, we used the U-series disequilibrium method to obtain absolute ages of paleoearthquake events associated with normal displacements along the active Mejillones and Salar del Carmen faults in the Coastal Range of the Atacama Desert of northern Chile. The 230Th- 234U disequilibrium ages in co-seismic gypsum salts sampled along the fault traces together with marine evidences indicate that earthquakes occurred at ca. 29.7 ± 1.7 ka, 11 ± 4 ka and 2.4 ± 0.8 ka. When coupled with paleoseismic marine and radiocarbon ( 14C) records in the nearby Mejillones Bay evidencing large dislocations along the Mejillones Fault, the geochronological dataset presented here is consistent with the notion that gypsum salts formed during large earthquakes as a result of co-seismic dilatancy pumping of saline waters along the major faults. Based on maximum observed cumulative vertical offsets in the studied faults, this phenomena could have occurred episodically at a rate in the order of 1:40 to 1:50 with respect to the very large subduction earthquakes during the latest Pleistocene-Holocene period. The results presented here reveal that the U-series disequilibrium method can be successfully applied to date the gypsum salts deposited along faults during seismic events, and therefore directly constrain the age of large paleoearthquakes in hyperarid and seismically active zones.

  10. A 22,000 14C year BP sediment and pollen record of climate change from Laguna Miscanti (23°S), northern Chile

    Science.gov (United States)

    Grosjean, M.; van Leeuwen, J. F. N.; van der Knaap, W. O.; Geyh, M. A.; Ammann, B.; Tanner, W.; Messerli, B.; Núñez, L. A.; Valero-Garcés, B. L.; Veit, H.

    2001-02-01

    Lake sediments and pollen, spores and algae from the high-elevation endorheic Laguna Miscanti (22°45'S, 67°45'W, 4140 m a.s.l., 13.5 km 2 water surface, 10 m deep) in the Atacama Desert of northern Chile provide information about abrupt and high amplitude changes in effective moisture. Although the lack of terrestrial organic macrofossils and the presence of a significant 14C reservoir effect make radiocarbon dating of lake sediments very difficult, we propose the following palaeoenvironmental history. An initial shallow freshwater lake (ca. 22,000 14C years BP) disappeared during the extremely dry conditions of the Last Glacial Maximum (LGM; 18,000 14C years BP). That section is devoid of pollen. The late-glacial lake transgression started around 12,000 14C years BP, peaked in two phases between ca. 11,000 and <9000 14C years BP, and terminated around 8000 14C years BP. Effective moisture increased more than three times compared to modern conditions (˜200 mm precipitation), and a relatively dense terrestrial vegetation was established. Very shallow hypersaline lacustrine conditions prevailed during the mid-Holocene until ca. 3600 14C years BP. However, numerous drying and wetting cycles suggest frequent changes in moisture, maybe even individual storms during the mid-Holocene. After several humid spells, modern conditions were reached at ca. 3000 14C years BP. Comparison between limnogeological data and pollen of terrestrial plants suggest century-scale response lags. Relatively constant concentrations of long-distance transported pollen from lowlands east of the Andes suggest similar atmospheric circulation patterns (mainly tropical summer rainfall) throughout the entire period of time. These findings compare favorably with other regional paleoenvironmental data.

  11. Solar Simulations for the Atacama Large Millimeter Observatory Network

    CERN Document Server

    Wedemeyer, Sven; Brajsa, Roman; Barta, Miroslav; Shimojo, Masumi

    2015-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) will be a valuable tool for observing the chromosphere of our Sun at (sub-)millimeter wavelengths at high spatial, temporal and spectral resolution and as such has great potential to address long-standing scientific questions in solar physics. In order to make the best use of this scientific opportunity, the Solar Simulations for the Atacama Large Millimeter Observatory Network has been initiated. A key goal of this international collaboration is to support the preparation and interpretation of future observations of the Sun with ALMA.

  12. Changes in the soil C cycle at the arid-hyperarid transition in the Atacama Desert

    Science.gov (United States)

    Ewing, S.A.; Macalady, J.L.; Warren-Rhodes, K.; McKay, C.P.; Amundson, Ronald

    2008-01-01

    We examined soil organic C (OC) turnover and transport across the rainfall transition from a biotic, arid site to a largely abiotic, hyperarid site. With this transition, OC concentrations decrease, and C cycling slows precipitously, both in surface horizons and below ground. The concentration and isotopic character of soil OC across this transition reflect decreasing rates of inputs, decomposition, and downward transport. OC concentrations in the arid soil increase slightly with depth in the upper meter, but are generally low and variable (???0.05%; total inventory of 1.82 kg m-2); OC-??14C values decrease from modern (+7???) to very 14C-depleted (-966???) with depth; and OC-??13C values are variable (-23.7??? to -14.1???). Using a transport model, we show that these trends reflect relatively rapid cycling in the upper few centimeters, and spatially variable preservation of belowground OC from root inputs, possibly during a previous, wetter climate supporting higher soil OC concentrations. In the driest soil, the OC inventory is the lowest among the sites (0.19 kg m-2), and radiocarbon values are 14C-depleted (-365??? to -696???) but show no trend with depth, indicating belowground OC inputs and long OC residence times throughout the upper meter (104 y). A distinct depth trend in ??13C values and OC/ON values within the upper 40 cm at the driest site may reflect photochemical alteration of organic matter at the soil surface, combined with limited subsurface decomposition and downward transport. We argue that while root inputs are preserved at the wetter sites, C cycling in the most hyperarid soil occurs through infrequent, rapid dissolved transport of highly photodegraded organic matter during rare rain events, each followed by a pulse of decomposition and subsequent prolonged drought. These belowground inputs are likely a primary control on the character, activity, and depth distribution of small microbial populations. While the lack of water is the dominant control on C cycling, very low C/N ratios of organic matter suggest that when rainfall occurs, hyperarid soils are effectively C limited. The preservation of fossil root fragments in the sediment beneath the driest soil indicates that wetter climate conditions preceded formation of this soil, and that vadose zone microbial activity has been extremely limited for the past 2 My. Copyright 2008 by the American Geophysical Union.

  13. Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr

    OpenAIRE

    Gayo, E. M; C. Latorre; C. M. Santoro; A Maldonado; R. De Pol-Holz

    2012-01-01

    Paleoclimate reconstructions reveal that Earth system has experienced sub-millennial scale climate changes over the past two millennia in response to internal/external forcing. Although sub-millennial hydroclimate fluctuations have been detected in the central Andes during this interval, the timing, magnitude, extent and direction of change of these events remain poorly defined. Here, we present a reconstruction of hydroclimate variations on the Pacific slope of the central Andes based on exc...

  14. Fundacion Chile Incubator : Chile Case Study

    OpenAIRE

    World Bank

    2014-01-01

    Foundation Chile was created in 1976 as a nonprofit governed jointly by the Chilean government and a large American conglomerate. It proactively introduces technology innovations and develops companies in target industries including agribusiness, marine resources, forestry, environment and chemical metrology, human capital, and information and communication technologies. Among its successe...

  15. First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile

    OpenAIRE

    Felipe Méndez-Abarca; Enrique A. Mundaca; Héctor A. Vargas

    2012-01-01

    First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile. Some aspects about the nesting biology of the potter wasp Hypodynerus andeus (Packard, 1869) are reported for the first time. Observations were carried out at the Azapa valley, coastal desert of northern Chile. A total of sixty nests were collected and examined, each composed by 1-14 cells, most of them found attached to concrete lamp posts. The only pre...

  16. Sensors for Desert Surveillance

    Directory of Open Access Journals (Sweden)

    B. S. Chauhan

    2005-10-01

    Full Text Available Various types of sensors-visible, passive night vision, infrared, synthetic aperture radar, etc can be used for desert surveillance. The surveillance capability of these sensors depends to a large extent, on various atmospheric effects, viz., absorption, scattering, aerosol, turbulence, and optical mirage. In this paper, effects of various atmospheric phenomena on the transmission of signals, merits and demerits of different means of surveillance under desert environmental conditions are discussed. Advanced surveillance techniques, ie, multisensor fusion, multi and hyperspectral imaging, having special significance for desert surveillance, have also been discussed.

  17. The Atacama Cosmology Telescope Project: A Progress Report

    OpenAIRE

    Kosowsky, Arthur; Collaboration, for the ACT

    2006-01-01

    The Atacama Cosmology Telescope is a project to map the microwave background radiation at arcminute angular resolution and high sensitivity in three frequency bands over substantial sky areas. Cosmological signals driving such an experiment are reviewed, and current progress in hardware construction is summarized. Complementary astronomical observations in other wavebands are also discussed.

  18. Site testing for the VLT in Northern Chile

    Science.gov (United States)

    Woltjer, L.

    The European Southern Observatory (ESO) will need sites for three telescopes. The telescopes considered include the 3.5 m New Technology Telescope to be completed in 1987, the 15 m Swedish-ESO mm/submm telescope, and the Very Large Telescope (VLT). The first two telescopes will probably be placed on La Silla. However, because of humidity considerations, a later transfer of the 15 m mm/submm telescope to a drier site appears possible. The main reason for conducting a new site survey is related to the VLT. Possible areas for establishing an observatory in the Southern Hemisphere are examined, taking into account Northern Chile. Attention is given to an area south of Antofagasta, mountains west of the Salar de Punta Negra, mountains between San Pedro de Atacama and El Tatio, mountains east of La Silla, problems regarding the observation of faint objects, water vapor content, and difficulties due to wind.

  19. Copper Bioleaching in Chile

    OpenAIRE

    Juan Carlos Gentina; Fernando Acevedo

    2016-01-01

    Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

  20. Marine Energy in Chile

    OpenAIRE

    Antonio Levy

    2012-01-01

    This is the first issue of a new series dedicated to deliver concise information on energy innovation published by the Energy Innovation Center at the IDB. This issue offers a primer on the potential for marine energy in Chile. The ocean is increasingly recognized as a viable source of renewable energy, and Chile, with its long coastline, powerful waves and tidal currents, has captured the attention of marine energy proponents. While harvesting this source of energy would increase sustainabil...

  1. Centro de Aymaras y visitantes en el Salar del Huasco, Chile

    OpenAIRE

    SOLA RUBIO, RAQUEL

    2015-01-01

    El proyecto se sitúa en el Salar del Huasco, en el Desierto de Atacama, provincia de Iquique (Región de Tarapacá), en el norte de Chile. El proyecto se divide en dos grandes partes: el Ayllu o poblado aymara, donde se ubica el programa destinado a las comunidades locales, y la Ramada o casa de huéspedes, que concentra el programa destinado a centro de visitantes para potenciar el turismo cultural. Se pretende construir un nodo de apoyo dentro de la red de asentamientos indígenas. El cent...

  2. ACTPol: Overview of a next-generation polarization-sensitive CMB observatory in Chile

    Science.gov (United States)

    McMahon, Jeff

    2013-04-01

    ACTPol is a new polarization sensitive receiver on the six-meter Atacama Cosmology Telescope which is surveying the Chilean sky and will produce deep maps of the polarization, temperature, and lensing of the Cosmic Microwave Background (CMB) in two frequency bands centered near 90 and 150 GHz. These measurements will improve constraints on inflation, neutrino properties, curvature, the primordial helium abundance, and dark energy. Cross correlating the ACTPol maps with optical surveys accessible from Chile will significantly amplify these constraints. In this talk I provide an overview of the project inclduing discussions of the instrument, science goals, and status of ACTPol.

  3. Contenido de metales en Cancer polyodon (Crustacea: Decapoda) en un sistema de bahías del norte de Chile (27°S) Metal contents in Cancer polyodon (Crustacea: Decapoda) in a bay system of northern Chile (27°S)

    OpenAIRE

    Alexis Castillo; Jorge Valdés

    2011-01-01

    El contenido de Zn, Cu, Cd, Pb, Fe, Al y Ni fue analizado en tejido muscular de Cancer polyodon en las bahías de Caldera, Calderilla, Inglesa y Salada (Atacama, Chile). Los resultados fueron comparados con estudios similares desarrollados por otros autores y la normativa de carácter nacional e internacional relacionada con el contenido de metales pesados en crustáceos para consumo humano. El orden de abundancia de los metales analizados en C. polyodon fue Cd

  4. Panamericanismo y arbitraje en conflictos de límites: la participación de estados unidos en la definición de la frontera argentino-chilena en la puna de atacama (1899)

    OpenAIRE

    Perla Zusman; María Cristina Hevilla

    2013-01-01

    Hacia finales del siglo XIX, el proyecto panamericanista implicó una serie de estrategias políticas, económicas y culturales destinadas a aumentar la influencia de Estados Unidos en Latinoamérica. En ese contexto, los países del Cono Sur comenzaron a aceptar el arbitraje de presidentes o delegados norteamericanos en los conflictos de límites territoriales. Este trabajo analiza la participación del país del norte en el diferendo de Argentina y Chile por la Puna de Atacama (1899). A través ...

  5. [Domestic violence in Chile].

    Science.gov (United States)

    León, Tomás; Grez, Marcela; Prato, Juan Andrés; Torres, Rafael; Ruiz, Sergio

    2014-08-01

    According to recent surveys, there is a high prevalence of domestic violence (DV) in Chile. A systematic review was conducted in PubMed, Scielo, and Lilacs with the MesH terms "Chile", "Mental Health", "Health", "Domestic Violence", to explore the impact of DV on health in Chile. Eleven studies fulfilled the inclusion criteria. Two studies were prospective, exploring the influence of DV on maternal-infant health. Nine studies explored the influence of DV on mental health in adults. DV was associated with deranged mental health indicators specially anxiety and depressive symptoms and suicidal ideation. Similar results were observed among mothers who were victims of violence and their children. It is concluded that DV is a complex phenomenon with serious effects on health. However the number of studies on the subject is low and new follow up studies are required. Predictive models for DV and effective preventive measures are urgently needed. PMID:25424674

  6. Copper Bioleaching in Chile

    Directory of Open Access Journals (Sweden)

    Juan Carlos Gentina

    2016-03-01

    Full Text Available Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first commercial operation in the world exclusively via bioleaching copper sulfides. Nowadays, all bioleaching operations run in the country contribute to an estimated 10% of total copper production. This article presents antecedents that have contributed to the development of copper bioleaching in Chile.

  7. Multi-temporal remote sensing analysis of salars in El Loa Province, Chile: Implications for water resource management

    Science.gov (United States)

    Markovich, K.; Pierce, S. A.

    2011-12-01

    Salar de Ascotán and Salar de Carcote are internally drained, evaporative basins located in the Atacama Desert, 200 km northeast of Antofogasta in Region II, Chile. The two salars are part of a regional groundwater system that recharges in the adjacent uplands to the east and terminates in the regional topographic low at Salar de Uyuni, Bolivia. This regional groundwater system is discharged locally as spring-fed perennial surface water that flows across the salar surface and either evaporates, or reinfiltrates, in lagoon-like environments. This perennial surface water supports diverse flora and fauna in the salar basins, including flamingo, vicuña, and the endemic fish species Orestias ascotanensis. Mining projects in the region began pumping the groundwater system in the Ascotán basin in the mid-1990's, leading to concern about the preservation of spring-fed surface flows. While hydrologic and ecologic monitoring efforts have been coordinated, data collection is limited to in-situ measurements and antecedent records precede extraction by approximately six months. Remote sensing can provide a means for large scale monitoring of the salars, as well as providing additional historical data to support environmental management of the systems. This comparative study utilizes satellite imagery to detect changes in surface water extent in the two salars and evaluate the results for possible correlation with climatic and/or anthropogenic factors. Landsat TM and ETM+ images from the time period of 1986-2011 are analyzed for surface water extent, and geographic information technologies are used to integrate the remotely sensed data with in-situ measurements. Early results indicate that surface water extent on the salar surface has diminished from 1986 and present day conditions. The decrease is most pronounced in the Ascotán basin, suggesting a possible correlation to anthropogenic influences. Also, the rate of decrease in surface water presence is most elevated in the

  8. Diversity of Bacteroidetes in high-altitude saline evaporitic basins in northern Chile

    Science.gov (United States)

    Dorador, Cristina; Meneses, Daniela; Urtuvia, Viviana; Demergasso, Cecilia; Vila, Irma; Witzel, Karl-Paul; Imhoff, Johannes F.

    2009-06-01

    The phylum Bacteroidetes represents one of the most abundant bacterial groups of marine and freshwater bacterioplankton. We investigated the diversity of Bacteroidetes in water and sediment samples from three evaporitic basins located in the highlands of northern Chile. We used both 16S rRNA gene clone libraries created with targeted Bacteroidetes-specific primers and separation of specifically amplified gene fragments by denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed a reduced richness of these organisms in samples from Salar de Huasco (two to four DGGE bands) increasing in Salar de Ascotán (two to seven DGGE bands) and Laguna Tebenquiche at Salar de Atacama (four to eight DGGE bands). Cluster analysis (WPGMA) of DGGE bands showed that bands from Salar de Huasco and Salar de Ascotán grouped together and samples from Salar de Atacama formed separate clusters in water and sediment samples, reflecting different Bacteroidetes communities between sites. Most of the sequences analyzed belonged to the family Flavobacteriaceae and clustered with the genera Psychroflexus, Gillisia, Maribacter, Muricauda, Flavobacterium, and Salegentibacter. The most abundant phylotype was highly related to Psychroflexus spp. and was recovered from all three study sites. The similarity of the analyzed sequences with their closest relatives in GenBank was typically Culture efforts will be necessary to get a better description of the diversity of this group in saline evaporitic basins of northern Chile.

  9. Large slope instabilities in Northern Chile and Southern Peru

    Science.gov (United States)

    Crosta, Giovanni B.; Hermanns, Reginald L.; Valbuzzi, Elena; Frattini, Paolo; Valagussa, Andrea

    2014-05-01

    Deep canyon incision into Tertiary paleosurfaces and large slope instabilities along the canyon flanks characterize the landscape of western slope of the Andes of northern Chile and South Peru. This area belongs to the Coastal Escarpment and Precordillera and is formed by coarse-grained clastic and volcanoclastic formations. The area is characterized by intense seismicity and long-term hyperaridity (Atacama Desert). Landslides along the canyon flanks affect volumes generally up to 1 km3 and locally evolved in large rock avalanches. We prepared a landslide inventory covering an area of about 30,000 km2, extending from Iquique (Chile) to the South and Tacna (Peru) to the North. A total of 606 landslides have been mapped in the area by use of satellite images and direct field surveys, prevalently including large phenomena. The landslides range from 1 10-3 km2 to 464 km2 (Lluta landslide). The total landslide area, inclusive of the landslide scarp and of the deposit, amounts to about 2,130 km2 (about 7% of the area). The mega landslides can be classified as large block slides that can evolve in large rock avalanches (e.g. Minimini landslide). Their initiation seems to be strongly associated to the presence of secondary faults and large fractures transversal to the slope. These landslides show evidence suggesting a re-incision by the main canyon network. This seems particularly true for the Lluta collapse where the main 'landslide' mass is masked or deleted by the successive erosion. Other landslides have been mapped along the Coastal Escarpment and some of the major tectonic escarpments with an E-W trend. We examined area-frequency distributions of landslides by developing logarithmically binned, non-cumulative size frequency distributions that report frequency density as a function of landslide planar area A. The size frequency distribution presents a strong undersampling for smaller landslides, due to the extremely old age of the inventory. For landslides larger than

  10. Infrastructure Concessions in Chile

    OpenAIRE

    Gómez-Lobo, Andrés; Hinojosa, Sergio

    2000-01-01

    To increase investment in infrastructure, in the early 1990s Chiles government introduced private capital into the transport infrastructure sector, covering roads and highways, bridges, tunnels, and airports. The chosen mechanism: a concession scheme through which private firms would finance and build a given project and then operate the infrastructure for a set of number of years, recover...

  11. The Geology of Chile

    OpenAIRE

    Cabrera, Lluís; Calafat, A.; Gimeno, D.; Liesa, M.; Proenza, J.; Sàbat, F.; Sáez, Alberto; Santanach, Pere

    2008-01-01

    6 páginas.-- Book review of "The Geology of Chile", by Teresa Moreno and Wes Gibbons (eds.) (2007). Geological Society. London (United Kingdom). 414 pages, 286 figures including maps, charts and pictures; 27, 5 x 21 cm, ISBN 978-1- 86239-219-9 (hardback) and ISBN 978-1-86239-220-5 (softback).

  12. Chile's Madam President

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    After becoming the first female to win a presidential election in the socially conservative country, Chilean President-elect Michelle Bachelet created history again when unveiling a cabinet that was absolutely gender-balanced on January 30. Following similar breakthroughs of women politicians in Liberia and Germany, what happened in Chile is considered another case of women gaining power worldwide.

  13. Tapetes microbianos del Salar de Llamará, norte de Chile Microbial mats from the Llamará salt flat, northern Chile

    Directory of Open Access Journals (Sweden)

    CECILIA DEMERGASSO

    2003-09-01

    incluyendo cocos y bacilos no identificados. En todos los tapetes muestreados en el Salar se encontraron bacterias reductoras de sulfato.Stratified photosynthetic microbial mats are described from the Salar de Llamará, a salt flat basin located in the Atacama desert of northern Chile. Microscopic and spectrophotometric techniques were used. The thickness of the photic zone of these communities spans 8 to 30 mm. This is probably due to the grain size and mineralogical composition of associated sediments. Three different types of mats were recognized. A first one was characterized by a green pigmented layer; a second with orange and green coloured layers, and the third with orange and green layers and an additional purple layer. At one sampling site, no pigmented layers were present. Sediments underlying the mats were white, but in one site, black coloured sediments were observed; this dark colour is probably the result of iron sulphide precipitation. Predominant microorganisms in the orange pigmented layers were diatoms and unicellular cyanobacteria, mainly from the Cyanothece and Synechococcus groups. Filamentous cyanobacteria Microleus sp. and Oscillatoria sp. were the most abundant in the green layer. When interstitial brines reached salinities between 12 and 33 %, no diatoms were observed, and the coccoidal cyanobacteria from the Synechococcus, Cyanothece and Gloeocapsa groups and genus Gloeobacter predominated over filamentous Cyanobacteria in the green layer. The purple layer was built primarily of anoxygenic phototrophic bacteria similar to cells of the genera Chromatium and Thiocapsa. Absorption spectra revealed that chlorophyll a is the most abundant pigment in most of analyzed samples. Integrated values of chlorophyll a and bacteriochlorophyll a reached values of up to 230 and 144 mg m-2 along all of the pigmented zone, respectively. Abundant non-photosynthetic microorganisms were found in the mats, including unidentified cocci and bacilli. Sulphate reducing

  14. Data characteristics and preliminary results from the atacama b-mode search (ABS)

    Science.gov (United States)

    Visnjic, Catherine

    The Atacama B-Mode Search (ABS) is a 145 GHz polarimeter located at a high altitude site on Cerro Toco, in the Andes of northern Chile. Having deployed in early 2012, it is currently in its second year of operation, observing the polarization of the Cosmic Microwave Background (CMB). It seeks to probe the as yet undetected odd-parity B-modes of the polarization, which would have been created by the primordial gravitational wave background (GWB) predicted by theories of inflation. The magnitude of the B-mode signal is characterized by the tensor-to-scalar ratio, r. ABS features 60 cm cryogenic reflectors in the crossed-Dragone configuration, and a warm, continuously rotating sapphire half-wave plate to modulate the polarization of incoming radiation. The focal plane consists of 480 antenna-coupled transition edge sensor bolometers, arranged in orthogonal pairs for polarization sensitivity, and coupled to feedhorns in a hexagonal array. In this thesis we describe the ABS instrument in the state in which it is now operating, outline the first season of observations, and characterize the data obtained. Focusing on observations of the primary CMB field during a one month reference period, we detail the algorithms currently used to select the data suitable for making maps. This is the first pass at data cuts and provides a conservative estimate for the sensitivity of ABS to the polarization modes in the sky. We project that with one year total observation time of the primary CMB field, ABS should be able to detect the B-mode signal at roughly the level of r = 0.03.

  15. Active faulting in northern Chile: ramp stacking and lateral decoupling along a subduction plate boundary?

    Science.gov (United States)

    Armijo, Rolando; Thiele, Ricardo

    1990-04-01

    Two large features parallel to the coastline of northern Chile have long been suspected to be the sites of young or active deformation: (1) The 700-km long Coastal Scarp, with average height (above sea level) of about 1000 m; (2) The Atacama Fault zone, that stretches linearly for about 1100 km at an average distance of 30-50 km from the coastline. New field observations combined with extensive analysis of aerial photographs demonstrate that both the Coastal Scarp and the Atacama Fault are zones of Quaternary and current fault activity. Little-degraded surface breaks observed in the field indicate that these fault zones have recently generated large earthquakes ( M = 7-8). Normal fault offsets observed in marine terraces in the Coastal Scarp (at Mejillones Peninsula) require tectonic extension roughly orthogonal to the compressional plate boundary. Strike-slip offsets of drainage observed along the Salar del Carmen and Cerro Moreno faults (Atacama Fault system) imply left-lateral displacements nearly parallel to the plate boundary. The left-lateral movement observed along the Atacama Fault zone may be a local consequence of E-W extension along the Coastal Scarp. But if also found everywhere along strike, left-lateral decoupling along the Atacama Fault zone would be in contradiction with the right lateral component of Nazca-South America motion predicted by models of present plate kinematics. Clockwise rotation with left-lateral slicing of the Andean orogen south of the Arica bend is one way to resolve this contradiction. The Coastal Scarp and the Atacama Fault zone are the most prominent features with clear traces of activity within the leading edge of continental South America. The great length and parallelism of these features with the subduction zone suggest that they may interact with the subduction interface at depth. We interpret the Coastal Scarp to be a west-dipping normal fault or flexure and propose that it is located over an east-dipping ramp stack at

  16. GOPHERUS AGASSIZII (Desert Tortoise)

    International Nuclear Information System (INIS)

    GOPHERLTS AGAISSIZII (Desert Tortoise). Predation. A variety of predators, most notably coyotes (Canis Iatrans) and Common Ravens (Corvis corau) have been reported to prey on hatchling desert tortoises (Emst et al. 1994). Turtles of the United States and Canada (Smithsonian Institution Press, Washington, D.C. 578 pp.). Here, we report an observation of a hatchling tortoise, fitted with a radiotransmitter, that was preyed upon by native fire ants (Solenopsis sp.) in the eastern Mojave Desert at Yucca Mountain, Nevada (36 degrees 50 minutes N, 116 degree 25 minutes E). On 8/27/94, tortoise No.9315 (carapace length = 45 mm, age = 5 d) was found alive with eyes, chin, and parts of the head and legs being eaten by ants. The tortoise was alive, but lethargic, and responded little when touched. Eight of 74 other radiomarked hatchlings monitored at Yucca Mountain during 1992-1994 were found dead with fire ants on their carcass 3-7 days after the hatchlings emerged from their nests. It is not known whether those tortoises were killed by ants or were being scavenged when found. While imported fire ants (S. invicta) have long been known to kill hatchling gopher tortoises (G. polyphemus; Mount 1981. J. Alabama Acad. Sci. 52: 71-78), native fire ants have previously not been implicated as predators of desert tortoises. However, only 1 of 75 (or at worst 9 of 75) was killed by fire ants, suggesting that although fire ants do kill hatchlings, they were not important predators on desert tortoises during this study. Tortoise specimens were deposited at the University of California at Berkeley

  17. New Phycitiplex Porter (Hymenoptera, Ichneumonidae) from Subandean Desert in northwest Argentina

    OpenAIRE

    Charles C. Porter

    2009-01-01

    Six new species of Phycitiplex (P. obscurior, P. tricinctus, P. unicinctus, P. peralta, P. trichroma, and P. lepidus) are described from material taken by Malaise trap in a humid ravine at Santa Vera Cruz in the Subandean Desert (Monte) of La Rioja Province (Argentina). These are keyed along with several closely related described species. Except for P. eremnus from central Chile, this genus is known only from the semiarid Chaco and Subandean biogeographic provinces in the northern half of Arg...

  18. Estacionalidad de las muertes en la puna de Atacama

    Directory of Open Access Journals (Sweden)

    Bejarano, Ignacio

    2001-01-01

    Full Text Available En distintas culturas y geografías la mortalidad se distribuye de acuerdo a un patrón estacional variable según las poblaciones. El objetivo de este trabajo fue analizar la estacionalidad de las muertes en un medio ambiente extremo como lo es la Puna de Atacama (PA. Los datos de defunciones (1890-1950 corresponden a dos localidades de la PA: Susques y San Pedro de Atacama. En el análisis se consideraron, por sexo, tres grupos de edad: a prerreproductiva (0-15 años (PRE, reproductiva (16-44 años (REP y postreproductiva (<45 años (POS. Se calculo el coeficiente de estacionalidad de Henry y para identificar estadísticamente variaciones estacionales se aplicó una prueba de homogeneidad. Se utilizó la prueba de Edwards para detectar ciclos armónicos en la distribución de muertes. Independientemente de la edad y el sexo se observó un patron estacional diferencial significativo que responde a un modelo de variación armónica simple, los coeficientes de Henry mas altos se presentaron en verano e invierno. Cuando se analiza la estacionalidad por grupo de edad y sexo el patrón previamente descripto se mantiene sólo en las edades REP y POS y en el sexo masculino. Este estudio proporciona un indicio del comportamiento de la estacionalidad de las muertes en la Puna de Atacama. Sin embargo no difiere del observado en poblaciones contemporáneas de países desarrollados, por lo que se concluye que el patrón observado no sería consecuencia directa de las condiciones climáticas, culturales, etc. de este ambiente extremo.

  19. A review of the Hexactinellida (Porifera) of Chile, with the first record of Caulophacus Schulze, 1885 (Lyssacinosida: Rossellidae) from the Southeastern Pacific Ocean.

    Science.gov (United States)

    Reiswig, Henry M; Araya, Juan Francisco

    2014-01-01

    All records of the 15 hexactinellid sponge species known to occur off Chile are reviewed, including the first record in the Southeastern Pacific of the genus Caulophacus Schulze, 1885, with the new species Caulophacus chilense sp. n. collected as bycatch in the deep water fisheries of the Patagonian toothfish Dissostichus eleginoides Smitt, 1898 off Caldera (27ºS), Region of Atacama, northern Chile. All Chilean hexactinellid species occur in bathyal to abyssal depths (from 256 up to 4142 m); nine of them are reported for the Sala y Gomez and Nazca Ridges, with one species each in the Juan Fernandez Archipelago and Easter Island. The Chilean hexactinellid fauna is still largely unknown, consisting of only 2.5 % of the known hexactinellid extant species. Further studies and deep water sampling are essential to assess their ecology and distribution, particularly in northern Chile. PMID:25544276

  20. Spent Fuel in Chile

    International Nuclear Information System (INIS)

    The government has made a complete and serious study of many different aspects and possible road maps for nuclear electric power with strong emphasis on safety and energy independence. In the study, the chapter of SFM has not been a relevant issue at this early stage due to the fact that it has been left for later implementation stage. This paper deals with the options Chile might consider in managing its Spent Fuel taking into account foreign experience and factors related to safety, economics, public acceptance and possible novel approaches in spent fuel treatment. The country’s distinctiveness and past experience in this area taking into account that Chile has two research reactors which will have an influence in the design of the Spent Fuel option. (author)

  1. Waste management in Chile

    International Nuclear Information System (INIS)

    The main radioactive waste management issues to be faced by the Chilean Nuclear Energy Commission (CCHEN) are discussed herein. Research reactor spent fuel management is the most outstanding challenge at the beginning of the 21st century. Interim storage appears to be the most promising alternative, allowing fuel safekeeping until a definitive step is taken. The situation regarding radioactive waste resulting from radioisotope applications in Chile will not undergo considerable change in the near future. Low and intermediate level radioactive waste management is being safely performed followed by interim storage of conditioned wastes. The strategy in the radioactive waste management plan, to be described as well, is meant to ensure the safe storage of radioactive wastes produced in Chile. (author)

  2. First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile Primeiras observações sobre a biologia da nidificação de Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) no vale de Azapa, norte do Chile

    OpenAIRE

    Felipe Méndez-Abarca; Enrique A. Mundaca; Héctor A. Vargas

    2012-01-01

    First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile. Some aspects about the nesting biology of the potter wasp Hypodynerus andeus (Packard, 1869) are reported for the first time. Observations were carried out at the Azapa valley, coastal desert of northern Chile. A total of sixty nests were collected and examined, each composed by 1-14 cells, most of them found attached to concrete lamp posts. The only pre...

  3. A new species of Eccopsis Zeller (Lepidoptera, Tortricidae from the coastal valleys of northern Chile, with the first continental record of E. galapagana Razowski & Landry

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2011-06-01

    Full Text Available A new species of Eccopsis Zeller (Lepidoptera, Tortricidae from the coastal valleys of northern Chile, with the first continental record of E. galapagana Razowski & Landry. Eccopsis Zeller, 1852 is reported for the first time from Chile. Eccopsis razowskii Vargas, n. sp. is described and illustrated based on specimens reared from larvae collected on native Acacia macracantha Willd. (Fabaceae in the coastal valleys of the northern Chilean desert. Eccopsis galapagana Razowski & Landry, 2008, previously known only from the Galapagos Islands, Ecuador, is recorded for the first time from continental South America. Larvae of the latter were collected in northern Chile feeding on Prosopis alba Griseb (Fabaceae.

  4. Stabilization of Desert Surfaces and Accumulation of Dust Under Biological Soil Crusts

    Science.gov (United States)

    Finstad, K. M.; Mcnicol, G.; Pfeiffer, M.; Amundson, R.

    2014-12-01

    Biological soil crusts (BSC) are known to play a critical role in the stabilization of desert surfaces by helping to protect sediment from wind and water erosion and aiding in the trapping of airborne particles. The crusts are often composed of cyanobacteria, algae, and fungi, and occupy the upper few cm of a soil. Due to their high tolerance of desiccation and ability to utilize fog and dew sources, BSC are able to exist in environments that may otherwise be too dry for vascular plants. In the hyperarid Atacama Desert, decades or more between measurable precipitation events has created a landscape devoid of macroscopic life. While precipitation is rare, coastal fog occurs regularly and microbial communities capable of utilizing fog and dew water are able to persist. Here we found cyanobacteria and lichen living in association with a thin sulfate and dust crust (~2 cm) covering the surface of 'dust plateaus'. Topographically the region is highly irregular and part of a largely erosional landscape. We hypothesized that these flat-topped plateaus are accretionary features that have been able to maintain dust accumulation for thousands of years as a result of the surface crusts. To test this hypothesis we conducted radiocarbon analysis of crusts and soil profiles at two sites approximately 30 km apart, one in a high fog zone and another in lower fog frequency zone. The radiocarbon analysis shows that sediment has been accumulating in the 'plateaus' for the past 15,000 years and that biological activity and rates of C cycling in the crust increase with increasing fog frequency and intensity. The ages of organic material in the dust decrease monotonically with decreasing soil thickness, suggestive of progressive upward growth by dust accumulation. Our data indicate that the BSC are capable of surviving in hyperarid the Atacama Desert, a Mars analogue, through the utilization of fog water, and that their presence can leave a visible geomorphic imprint on the landscape.

  5. Primary Medical Care in Chile

    DEFF Research Database (Denmark)

    Scarpaci, Joseph L.

    Primary medical care in Chile: accessibility under military rule [Front Cover] [Front Matter] [Title Page] Contents Tables Figures Preface Chapter 1: Introduction Chapter 2: The Restructuring of Medical Care Financing in Chile Chapter 3: Inflation and Medical Care Accessibility Chapter 4: Help......-Seeking Behavior of the Urban Poor Chapter 5: Spatial Organization and Medical Care Accessibility Chapter 6: Conclusion...

  6. Chile rural electrification cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Flowers, L. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-01

    The author describes a joint program to use renewables for rural electrification projects in Chile. The initial focus was in a limited part of the country, involving wind mapping, pilot project planning, training, and development of methodologies for comparative evaluations of resources. To this point three wind hybrid systems have been installed in one region, as a part of the regional private utility, and three additional projects are being designed. Additional resource assessment and training is ongoing. The author points out the difficulties in working with utilities, the importance of signed documentation, and the need to look at these programs as long term because of the time involved in introducing such new technologies.

  7. Biomasa en Chile

    OpenAIRE

    Nilsson Cifuentes, Gabriel; Rodríguez Monroy, Carlos

    2012-01-01

    El artículo presenta el desarrollo de la biomasa en Chile, dentro del complejo marco energético existente en el país, el cual, aún no logra potenciar e incentivar el desarrollo de energías renovables y depende fuertemente de los combustibles fósiles, acrecentando el riesgo latente de sufrir una crisis energética, en el mediano plazo, producto de la paulatina incorporación de nuevas centrales generadoras de energías, que satisfagan la creciente demanda energética pronosticada. Este ar...

  8. Physiological adaptation in desert birds

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  9. Chile: Transantiago recargado Chile: Transantiago Reloaded

    Directory of Open Access Journals (Sweden)

    RODRIGO MARDONES Z

    2008-01-01

    Full Text Available El 2007 fue el segundo año del gobierno de Michelle Bachelet. Se trató de un año sin elecciones; con un buen desempeño económico, a pesar de una inflación creciente en los últimos meses; y marcado por la discusión sobre escándalos de corrupción. Sin embargo, lo que más afectó al Gobierno fue la desastrosa puesta en marcha de la reforma al sistema de transporte público de la capital: Transantiago. Este puso un velo sobre los importantes avances en materias previsionales y educacionales, cuestionando no sólo la capacidad ejecutiva del Gobierno, sino que profundizando un flanco de indisciplina al interior de la coalición oficialista (Concertación; síntoma de su desgaste después de 17 años ocupando la Presidencia de Chile.The year 2007 was the second in Michelle Bachelet’s presidencial term. It was a year free of elections, exhibiting a fairly good economic performance, despite the high rate of inflation shown during the last months. Public discussion on corruption escandals was frequent; however, the most important issue was the disestrous beginning of the reform on the public transportation system of the country’s capital: Transantiago. This has placed a veil over the important achievements on the pension system and education, questioning not only the government’s capacity, but also opening and edge of indiscipline within the ruling coalition (Concertación, which is a symtom of its erosion after 17 years in the presidential office.

  10. 27 CFR 9.154 - Chiles Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chiles Valley. 9.154... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley.” (b) Approved maps. The appropriate maps for determining the boundary of the Chiles...

  11. Hidatidosis humana en Chile. Seroprevalencia y estimación del número de personas infectadas Human Hydatidosis in Chile. Seroprevalence and an estimate of the number of infected people

    OpenAIRE

    Hugo Schenone; María del Carmen Contreras; Patricia Salinas; Lea Sandoval; Tirza Saavedra; Antonio Rojas

    1999-01-01

    Chile is located in the southwestern border of South America. The country is 4,329 km long and 96-342 wide. From north to south it is divided into five marked different biogeographical zones: deserts, steppes, bushes, forests (cattle raising) and austral (sheep raising). Population (June1999) 15,017,760 (14.6% rural). Human hydatidosis is endemic in Chile. According to Ministry of Health information about 320 cases are registered each year. In order to find out the likely prevalence of human ...

  12. The Atacama Cosmology Telescope: cross correlation with Planck maps

    International Nuclear Information System (INIS)

    We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACT × Planck cross-spectra. We use these cross-correlations to measure the calibration of the ACT data at 148 and 218 GHz relative to Planck, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments

  13. The Atacama Cosmology Telescope: cross correlation with Planck maps

    Energy Technology Data Exchange (ETDEWEB)

    Louis, Thibaut; Calabrese, Erminia; Dunkley, Joanna; Næss, Sigurd [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Addison, Graeme E.; Hincks, Adam D. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Hasselfield, Matthew; Hlozek, Renée [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Bond, J. Richard; Hajian, Amir [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [Argonne National Laboratory, 9700 S. Cass Ave., Lemont, IL 60439 (United States); Devlin, Mark J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.A (United States); Dünner, Rolando; Infante, Leopoldo [Departamento de Astronomía y Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Gralla, Megan; Marriage, Tobias A. [Dept. of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Huffenberger, Kevin [Department of Physics, Florida State University, Keen Physics Building, 77 Chieftan Way, Tallahassee, Florida (United States); Kosowsky, Arthur [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban, 4041 (South Africa); Niemack, Michael D., E-mail: Thibaut.Louis@astro.ox.ac.uk [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); and others

    2014-07-01

    We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACT × Planck cross-spectra. We use these cross-correlations to measure the calibration of the ACT data at 148 and 218 GHz relative to Planck, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments.

  14. The Atacama Cosmology Telescope: Cross Correlation with Planck maps

    CERN Document Server

    Louis, Thibaut; Hasselfield, Matthew; Bond, J Richard; Calabrese, Erminia; Das, Sudeep; Devlin, Mark J; Dunkley, Joanna; Dünner, Rolando; Gralla, Megan; Hajian, Amir; Hincks, Adam D; Hlozek, Renée; Huffenberger, Kevin; Infante, Leopoldo; Kosowsky, Arthur; Marriage, Tobias A; Moodley, Kavilan; Næss, Sigurd; Niemack, Michael D; Nolta, Michael R; Page, Lyman A; Partridge, Bruce; Sehgal, Neelima; Sievers, Jonathan L; Spergel, David N; Staggs, Suzanne T; Walter, Benjamin Z; Wollack, Edward J

    2014-01-01

    We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACTxPlanck cross-spectra. We use these cross-correlations to calibrate the ACT data at 148 and 218 GHz, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments.

  15. Design and development status of the University of Tokyo Atacama Observatory 6.5m telescope

    Science.gov (United States)

    Morokuma, Tomoki; Aoki, Tsutomu; Doi, Mamoru; Handa, Toshihiro; Kamizuka, Takafumi; Kato, Natsuko; Kawara, Kimiaki; Kohno, Kotaro; Konishi, Masahiro; Koshida, Shintaro; Minezaki, Takeo; Miyata, Takashi; Motohara, Kentaro; Sako, Shigeyuki; Soyano, Takao; Takahashi, Hidenori; Tamura, Yoichi; Tanabe, Toshihiko; Tanaka, Masuo; Tarusawa, Ken'ichi; Yoshii, Yuzuru

    2014-07-01

    We here summarize the design and the current fabrication status for the University of Tokyo Atacama Observatory (TAO) 6.5-m telescope. The TAO telescope is operated at one of the best sites for infrared observations, at the summit of Co. Chajnantor in Chile, and is optimized for infrared observations. The telescope mount, mirrors, and mirror support systems are now at the final design phase. The mechanical and optical designs are done by following and referring to those of the Magellan telescopes, MMT, and Large Binocular Telescope. The final focal ratio is 12.2. The field-of-view is as wide as 25 arcmin in diameter and the plate scale is 2.75 arcsec mm-1. The F/1.25 light-weighted borosilicate (Ohara E6) honeycomb primary mirror is adopted and being fabricated by the Steward Observatory Mirror Laboratory. The primary mirror is supported by 104 loadspreaders bonded to the back surface of the mirror and 6 adjustable hardpoints. The mirror is actively controlled by adjusting the actuator forces based on the realtime wavefront measurement. The actuators are optimized for operation at high altitude of the site, 5640-m above the sea level, by considering the low temperature and low air pressure. The mirror is held in the primary mirror cell which is used as a part of the vacuum chamber when the mirror surface is aluminized without being detached from the cell. The pupil is set at the secondary mirror to minimize infrared radiation into instruments. The telescope has two Nasmyth foci for near-infrared and mid-infrared facility instruments (SWIMS and MIMIZUKU, respectively) and one folded-Caseggrain focus for carry-in instruments. At each focus, autoguider and wavefront measurement systems are attached to achieve seeing-limited image quality. The telescope mount is designed as a tripod-disk type alt-azimuth mount. Both the azimuthal and elevation axes are supported by and run on the hydrostatic bearings. Friction drives are selected for these axis drives. The telescope

  16. Status of the Pi of the Sky telescopes in Spain and Chile

    Science.gov (United States)

    Majcher, A.; Batsch, T.; Castro-Tirado, A. J.; Ćwiek, A.; Czyrkowski, H.; Ćwiok, M.; DÄ browski, R.; Jelínek, M.; Kasprowicz, G.; Małek, K.; Mankiewicz, L.; Nawrocki, K.; Obara, Ł.; Opiela, R.; Piotrowski, L. W.; Siudek, M.; Sokołowski, M.; Wawrzaszek, R.; Wrochna, G.; Zaremba, M.; Żarnecki, A. F.

    2015-09-01

    "Pi of the Sky" is a system of wide field of view robotic telescopes, which search for short timescale astrophysical phenomena, especially for prompt optical GRB emission. The system was designed for autonomous operation, monitoring a large fraction of the sky with 12m-13m range and time resolution of the order of 1 - 10 seconds. For now there are two working "Pi of the Sky" observatories: in San Pedro de Atacama (Chile) and near Mazagón in Southern Spain. In this paper we report on the status of the project, as well as recent observation of asteroid 2004BL86, which passed the Earth in late January 2015, DG CVn outburst in 2014, satellites observations and our future plans.

  17. El Niño southern oscillation and its effect on fog oases along the Peruvian and Chilean coastal deserts

    OpenAIRE

    Manrique Paredes, Rosa Soledad

    2011-01-01

    Fog oases, locally named Lomas, are distributed in a fragmented way along the western coast of Chile and Peru (South America) between ~6°S and 30°S following an altitudinal gradient determined by a fog layer. This fragmentation has been attributed to the hyper aridity of the desert. However, periodically climatic events influence the ‘normal seasonality’ of this ecosystem through a higher than average water input that triggers plant responses (e.g. primary productivity and phen...

  18. La tesis de título de Guillermo Ulriksen Becker (1952: Bases para la Planeación Regional del Norte Chico: Provincias de Atacama y Coquimbo. /Graduation Project (Thesis of the architect William Ulriksen Becker (1952: Basis for Region Planning of the “Norte Chico”: Atacama and Coquimbo provinces.

    Directory of Open Access Journals (Sweden)

    Pávez Reyes, María Isabel

    2008-06-01

    Full Text Available Se presenta la tesis de título en planeamiento regional de Guillermo Ulriksen Becker (n.1905 – m. 1979 presentada en 1953 en la, entonces, “Facultad de Arquitectura” de la Universidad de Chile: Bases para la Planeación Regional del Norte Chico: Provincias de Atacama y Coquimb. Este estudio que constituye no sólo una radiografía del estado del desarrollo del Norte Chico hace cincuenta y cinco años, sino que también un señalamiento del potencial posible de desarrollar en la perspectiva del largo plazo, y de los aspectos negativos que se van sucediendo o pudieran suceder atentando contra dicho potencial./This work presents the graduation project of Guillermo Ulriksen (1905-1979. That thesis was presented to get the title of architect in the then called "Facultad de Arquitectura" of the Universidad de Chile, and it shows a complete scan of the development of the "Norte Chico", 55 years ago, indicating its potentials in a long term basis.

  19. Invited article: millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument.

    Science.gov (United States)

    Schwan, D; Ade, P A R; Basu, K; Bender, A N; Bertoldi, F; Cho, H-M; Chon, G; Clarke, John; Dobbs, M; Ferrusca, D; Güsten, R; Halverson, N W; Holzapfel, W L; Horellou, C; Johansson, D; Johnson, B R; Kennedy, J; Kermish, Z; Kneissl, R; Lanting, T; Lee, A T; Lueker, M; Mehl, J; Menten, K M; Muders, D; Pacaud, F; Plagge, T; Reichardt, C L; Richards, P L; Schaaf, R; Schilke, P; Sommer, M W; Spieler, H; Tucker, C; Weiss, A; Westbrook, B; Zahn, O

    2011-09-01

    The Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument is a millimeter-wave cryogenic receiver designed to observe galaxy clusters via the Sunyaev-Zel'dovich effect from the 12 m APEX telescope on the Atacama plateau in Chile. The receiver contains a focal plane of 280 superconducting transition-edge sensor (TES) bolometers instrumented with a frequency-domain multiplexed readout system. The bolometers are cooled to 280 mK via a three-stage helium sorption refrigerator and a mechanical pulse-tube cooler. Three warm mirrors, two 4 K lenses, and a horn array couple the TES bolometers to the telescope. APEX-SZ observes in a single frequency band at 150 GHz with 1' angular resolution and a 22' field-of-view, all well suited for cluster mapping. The APEX-SZ receiver has played a key role in the introduction of several new technologies including TES bolometers, the frequency-domain multiplexed readout, and the use of a pulse-tube cooler with bolometers. As a result of these new technologies, the instrument has a higher instantaneous sensitivity and covers a larger field-of-view than earlier generations of Sunyaev-Zel'dovich instruments. The TES bolometers have a median sensitivity of 890 μK(CMB)√s (NEy of 3.5 × 10(-4) √s). We have also demonstrated upgraded detectors with improved sensitivity of 530 μK(CMB)√s (NEy of 2.2 × 10(-4) √s). Since its commissioning in April 2007, APEX-SZ has been used to map 48 clusters. We describe the design of the receiver and its performance when installed on the APEX telescope. PMID:21974566

  20. Karst evolution in the Cordillera de la Sal (Atacama, Chili)

    Science.gov (United States)

    de Waele, J.; Forti, P.; Picotti, V.; Zini, L.; Cucchi, F.; Brook, G.

    2009-04-01

    Rock salt composed of halite is at least three orders of magnitude more soluble than limestone. Because of this very high solubility rock salt rarely crops out extensively at the surface and is readily dissolved leaving insoluble residue (mainly clays and marls). Rock salt can only survive at the surface where climate is extremely arid and normally displays a large set of typical solution morphologies similar to those developed on limestone. Solution of rock salt also leads to the formation of underground caves several km long. Close to the village of San Pedro de Atacama, North of the Salar de Atacama basin, there is an important NNE-SSW trending elongated anticlinal ridge composed of Oligo-Miocene evaporitic rocks known under the name Cordillera de la Sal. The thick salt beds of this ridge, even in this hyperarid climate (mean annual rainfall is below 20 mm/y and there may be no rain for several years), have been karstified by occasional rains and have a well developed surface karst geomorphology with extremely sharp rillenkarren often isolating salt pinnacles of up to 15 m in height. During the past 10 years interesting salt caves have been discovered in these halite beds and a detailed morphological study has been carried out both at the surface and in the most important caves with the aim of understanding the mechanisms responsible for their formation and evolution. Sixteen wood and bone fragments from the ceilings of caves and from diamictons in passages have been AMS radiocarbon dated, allowing us to determine when the cave systems formed and when the major sediment units were emplaced. In fact, cave formation appears to have been very rapid, with development of huge cave passages in salt (more than 10 m wide and 30 m high) in less than 2,000 years. Moreover, detailed surveys of cave morphology (e.g. meanders, erosion benches) and sediments (diamictons) suggest that the caves were formed by short-lived flash floods, probably produced by single extreme

  1. Mate desertion in the snail kite

    Science.gov (United States)

    Beissinger, S.R.; Snyder, N.F.R.

    1988-01-01

    Mate desertion during the breeding cycle was documented at 28 of 36 (78%) snail kite, Rostrhamus sociabilis nests in Florida between 1979 and 1983. Offspring mortality occurred at only one deserted nest, however. Parents that were deserted by their mates continued to care for their young until independence (3?5 additional weeks) and provided snails at a rate similar to that of both parents combined before desertion. Males and females deserted with nearly equal frequency, except in 1982 when more females deserted. No desertion occurred during drought years, whereas desertion occurred at nearly every nest during favourable conditions. The occurrence of mate desertion was generally related to indirect measures of snail abundance: foraging range, snail delivery rates to the young and growth rates. Small broods were deserted more frequently by females than by males and tended to be deserted earlier than large ones. After desertion, deserters had the opportunity to re-mate and nest again since breeding seasons were commonly lengthy, but whether they did so was impossible to determine conclusively in most cases. The deserted bird sometimes incurred increased energetic costs and lost breeding opportunities during periods of monoparental care.

  2. Raman imaging in geomicrobiology: endolithic phototrophic microorganisms in gypsum from the extreme sun irradiation area in the Atacama Desert

    Czech Academy of Sciences Publication Activity Database

    Vítek, Petr; Ascao, C.; Artieda, O.; Wierzchos, J.

    2016-01-01

    Roč. 408, č. 15 (2016), s. 4083-4092. ISSN 1618-2642 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : hyperspectral imaging * carotenoids * astrobiology * photosynthesis * adaptation strategy * Mars Subject RIV: EE - Microbiology, Virology Impact factor: 3.436, year: 2014

  3. The fruit fly programme in Chile

    International Nuclear Information System (INIS)

    Full text: country. In fact, no species of the genera Ceratitis, Bactrocera, Anastrepha, Dacus and Toxotrypana exist in the country. This programme uses the Fruit fly National Detection System, which includes detection of the pest by trapping and fruit sampling in different areas located between the I and XI Regions of the country. This system is approved by the Chilean trade partners on the basis of the fruit fly-free recognition. For the Chilean fresh fruit exports, this is an important advantage, because there is no need to apply quarantine treatments or any other restriction measure. Chile has also a huge fruit industry, whose export revenues last season reached USD 1,900 million. This fact has permitted to undertake continuously a big effort to maintain that phytosanitary condition. Since Chile is the only fruit-fly free Latin American country, it has to face a continuous biological pressure of fruit flies, mainly C. capitata, to invade its territory. But the country has also some important advantages to prevent flies migrating due to its natural isolation. These natural barriers are the Los Andes ranges in the east, thousands of kilometers of desert in the north, the Pacific Ocean in the west and finally an extremely cold, sub polar climate in the south. This isolation has led to the NPPO officials to believe that the passive spread, through smuggling and hidden fruit in passenger's baggage, to be the most likely source of fruit fly entries. Because of that, Chile has a very strict quarantine system with border control stations at every point of entry. The only exception to the mentioned isolation is Arica Province on the border with Peru. There, SAG applies an area-wide preventative approach through the rearing and release of sterile insects, as well as bait spraying in the border area, which is mainly desert, but has some 'green spots' that allow the fly to alight for resting and feeding. Additionally, through bi-national agreements, common activities are

  4. Cretaceous to Paleogene geology of the Salar de Atacama basin, northern Chile : a reappraisal of the Purilactis Group stratigraphy

    OpenAIRE

    Mpodozis, C.; Arriagada, C.; Roperch, Pierrick

    1999-01-01

    De nouvelles données stratigraphiques, géochronologiques, structurales et paléomagnétiques acquises lors de l'étude de la bordure orientale de la Cordillère de Domeyko à la latitude du Salar d'Atacma nous permettent de préciser la stratigraphie du Groupe Purilactis. Celui-ci comprend une succession de 7 séquences sédimentaires et volcaniques. L'observation de la polarité normale dans les unités inférieures du Groupe Purilactis suggère un âge crétacé moyen pour ces unités. Les noveaux âges rad...

  5. Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea

    OpenAIRE

    Pyenson, Nicholas D.; Gutstein, Carolina S.; Parham, James F.; Le Roux, Jacobus P.; Chavarría, Catalina Carreño; Little, Holly; Metallo, Adam; Rossi, Vincent; Valenzuela-Toro, Ana M.; Velez-Juarbe, Jorge; Cara M. Santelli; Rogers, David Rubilar; Cozzuol, Mario A.; Mario E Suárez

    2014-01-01

    Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur ...

  6. Far Sidelobes Measurement of the Atacama Cosmology Telescope

    Science.gov (United States)

    Duenner, Rolando; Gallardo, Patricio; Wollack, Ed; Henriquez, Fernando; Jerez-Hanckes, Carlos

    2012-01-01

    The Atacama Cosmology Telescope (ACT) is a 6m telescope designed to map the Cosmic Microwave Background (CMB) simultaneously at 145GHz, 220 GHz and 280 GHz. Its off-axis Gregorian design is intended to minimize and control the off-axis sidelobe response, which is critical for scientific purposes. The expected sidelobe level for this kind of design is less than -50 dB and can be challenging to measure. Here we present a measurement of the 145 GHz far sidelobes of ACT done on the near-field of the telescope. We used a 1 mW microwave source placed 13 meters away from the telescope and a chopper wheel to produce a varying signal that could be detected by the camera for different orientations of the telescope. The source feed was designed to produce a wide beam profile. Given that the coupling is expected to be dominated by diffraction over the telescope shielding structure, when combined with a measurements of the main beam far field response, these measurement can be used to validate elements of optical design and constrain the level of spurious coupling at large angles. Our results show that the diffractive coupling beyond the ground screen is consistently below -75 dB, satisfying the design expectations.

  7. The Atacama Cosmology Telescope: CMB Polarization at $200<\\ell<9000$

    CERN Document Server

    Naess, Sigurd; McMahon, Jeff; Niemack, Michael D; Addison, Graeme E; Ade, Peter A R; Allison, Rupert; Amiri, Mandana; Baker, Andrew; Battaglia, Nick; Beall, James A; de Bernardis, Francesco; Bond, J Richard; Britton, Joe; Calabrese, Erminia; Cho, Hsiao-mei; Coughlin, Kevin; Crichton, Devin; Das, Sudeep; Datta, Rahul; Devlin, Mark J; Dicker, Simon R; Dunkley, Joanna; Dünner, Rolando; Fowler, Joseph W; Fox, Anna E; Gallardo, Patricio; Grace, Emily; Gralla, Megan; Hajian, Amir; Halpern, Mark; Henderson, Shawn; Hill, J Colin; Hilton, Gene C; Hilton, Matt; Hincks, Adam D; Hlozek, Renée; Ho, Patty; Hubmayr, Johannes; Huffenberger, Kevin M; Hughes, John P; Infante, Leopoldo; Irwin, Kent; Jackson, Rebecca; Klein, Jeff; Koopman, Brian; Kosowsky, Arthur; Li, Dale; Louis, Thibaut; Lungu, Marius; Madhavacheril, Mathew; Marriage, Tobias A; Maurin, Loïc; Menanteau, Felipe; Moodley, Kavilan; Munson, Charles; Newburgh, Laura; Nibarger, John; Nolta, Michael R; Page, Lyman A; Pappas, Christine; Partridge, Bruce; Rojas, Felipe; Schmitt, Benjamin; Sehgal, Neelima; Sherwin, Blake D; Sievers, Jon; Simon, Sara; Spergel, David N; Staggs, Suzanne T; Switzer, Eric R; Thornton, Robert; Trac, Hy; Tucker, Carole; Van Engelen, Alexander; Ward, Jon; Wollack, Edward J

    2014-01-01

    We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with the Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months of observing. Four regions of sky covering a total of 270 square degrees were mapped with an angular resolution of $1.3'$. The map noise levels in the four regions are between 11 and 17 $\\mu$K-arcmin. We present TT, TE, EE, TB, EB, and BB power spectra from three of these regions. The observed E-mode polarization power spectrum, displaying six acoustic peaks in the range $200<\\ell<3000$, is an excellent fit to the prediction of the best-fit cosmological models from WMAP9+ACT and Planck data. The polarization power spectrum, which mainly reflects primordial plasma velocity perturbations, provides an independent determination of cosmological parameters consistent with those based on the temperature power spectrum, which results mostly from primordial density perturbations. We find that without masking any point sou...

  8. Survey strategy optimization for the Atacama Cosmology Telescope

    CERN Document Server

    De Bernardis, F; Hasselfield, M; Alonso, D; Bond, J R; Calabrese, E; Choi, S K; Crowley, K T; Devlin, M; Dunkley, J; Gallardo, P A; Henderson, S W; Hilton, M; Hlozek, R; Ho, S P; Huffenberger, K; Koopman, B J; Kosowsky, A; Louis, T; Madhavacheril, M S; McMahon, J; Naess, S; Nati, F; Newburgh, L; Niemack, M D; Page, L A; Salatino, M; Schillaci, A; Schmitt, B L; Sehgal, N; Sievers, J L; Simon, S M; Spergel, D N; Staggs, S T; van Engelen, A; Vavagiakis, E M; Wollack, E J

    2016-01-01

    In recent years there have been significant improvements in the sensitivity and the angular resolution of the instruments dedicated to the observation of the Cosmic Microwave Background (CMB). ACTPol is the first polarization receiver for the Atacama Cosmology Telescope (ACT) and is observing the CMB sky with arcmin resolution over about 2000 sq. deg. Its upgrade, Advanced ACTPol (AdvACT), will observe the CMB in five frequency bands and over a larger area of the sky. We describe the optimization and implementation of the ACTPol and AdvACT surveys. The selection of the observed fields is driven mainly by the science goals, that is, small angular scale CMB measurements, B-mode measurements and cross-correlation studies. For the ACTPol survey we have observed patches of the southern galactic sky with low galactic foreground emissions which were also chosen to maximize the overlap with several galaxy surveys to allow unique cross-correlation studies. A wider field in the northern galactic cap ensured significant...

  9. The Atacama Cosmology Telescope: The polarization-sensitive ACTPol instrument

    CERN Document Server

    Thornton, R J; Aiola, S; Angile, F E; Amiri, M; Beall, J A; Becker, D T; Cho, H-M; Choi, S K; Corlies, P; Coughlin, K P; Datta, R; Devlin, M J; Dicker, S R; Dunner, R; Fowler, J W; Fox, A E; Gallardo, P A; Gao, J; Grace, E; Halpern, M; Hasselfield, M; Henderson, S W; Hilton, G C; Hincks, A D; Ho, S P; Hubmayr, J; Irwin, K D; Klein, J; Koopman, B; Li, Dale; Louis, T; Lungu, M; Maurin, L; McMahon, J; Munson, C D; Naess, S; Nati, F; Newburgh, L; Nibarger, J; Niemack, M D; Niraula, P; Nolta, M R; Page, L A; Pappas, C G; Schillaci, A; Schmitt, B L; Sehgal, N; Sievers, J L; Simon, S M; Staggs, S T; Tucker, C; Uehara, M; van Lanen, J; Ward, J T; Wollack, E J

    2016-01-01

    The Atacama Cosmology Telescope (ACT) is designed to make high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3 degree field of view, 100 mK cryogenics with continuous cooling, and meta material anti-reflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev-Zel'dovich and kinetic Sunyaev-Zel'dovich signals, and CMB lensing due to large scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the f...

  10. The Atacama Cosmology Telescope: Data Characterization and Map Making

    CERN Document Server

    Dünner, Rolando; Marriage, Tobias A; Sievers, Jon; Acquaviva, Viviana; Addison, Graeme E; Ade, Peter A R; Aguirre, Paula; Amiri, Mandana; Appel, John William; Barrientos, L Felipe; Battistelli, Elia S; Bond, J Richard; Brown, Ben; Burger, Bryce; Calabarese, Erminia; Chervenak, Jay; Das, Sudeep; Devlin, Mark J; Dicker, Simon R; Doriese, W Bertrand; Dunkley, Joanna; Essinger-Hileman, Thomas; Fisher, Ryan P; Gralla, Megan B; Fowler, Joseph W; Hajian, Amir; Halpern, Mark; Hernández-Monteagudo, Carlos; Hilton, Gene C; Hilton, Matt; Hincks, Adam D; Hlozek, Renée; Huffenberger, Kevin M; Hughes, David H; Hughes, John P; Infante, Leopoldo; Irwin, Kent D; Juin, Jean Baptiste; Kaul, Madhuri; Klein, Jeff; Kosowsky, Arthur; Lau, Judy M; Limon, Michele; Lin, Yen-Ting; Louis, Thibaut; Lupton, Robert H; Marsden, Danica; Martocci, Krista; Mauskopf, Phil; Menanteau, Felipe; Moodley, Kavilan; Moseley, Harvey; Netterfield, Calvin B; Niemack, Michael D; Nolta, Michael R; Page, Lyman A; Parker, Lucas; Partridge, Bruce; Quintana, Hernán; Reid, Beth; Sehgal, Neelima; Sherwin, Blake D; Spergel, David N; Staggs, Suzanne T; Swetz, Daniel S; Switzer, Eric R; Thornton, Robert; Trac, Hy; Tucker, Carole; Warne, Ryan; Wilson, Grant; Wollack, Ed; Zhao, Yue

    2012-01-01

    We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hours of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hours of observation. From these, 1085 hours were devoted to a 850 deg^2 stripe (11.2 hours by 9.1 deg) centered on a declination of -52.7 deg, while 175 hours were devoted to a 280 deg^2 stripe (4.5 hours by 4.8 deg) centered at the celestial equator. We discuss sources of statistical and systematic noise, calibration, telescope pointing, and data selection. Out of 1260 survey hours and 1024 detectors per array, 816 hours and 593 effective detectors remain after data selection for this frequency band, yielding a 38% survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-o...

  11. E-ELT Site Chosen - World's Biggest Eye on the Sky to be Located on Armazones, Chile

    Science.gov (United States)

    2010-04-01

    On 26 April 2010, the ESO Council selected Cerro Armazones as the baseline site for the planned 42-metre European Extremely Large Telescope (E-ELT). Cerro Armazones is a mountain at an altitude of 3060 metres in the central part of Chile's Atacama Desert, some 130 kilometres south of the town of Antofagasta and about 20 kilometres from Cerro Paranal, home of ESO's Very Large Telescope. "This is an important milestone that allows us to finalise the baseline design of this very ambitious project, which will vastly advance astronomical knowledge," says Tim de Zeeuw, ESO's Director General. "I thank the site selection team for the tremendous work they have done over the past few years." ESO's next step is to build a European extremely large optical/infrared telescope (E-ELT) with a primary mirror 42 metres in diameter. The E-ELT will be "the world's biggest eye on the sky" - the only such telescope in the world. ESO is drawing up detailed construction plans together with the community. The E-ELT will address many of the most pressing unsolved questions in astronomy, and may, eventually, revolutionise our perception of the Universe, much as Galileo's telescope did 400 years ago. The final go-ahead for construction is expected at the end of 2010, with the start of operations planned for 2018. The decision on the E-ELT site was taken by the ESO Council, which is the governing body of the Organisation composed of representatives of ESO's fourteen Member States, and is based on an extensive comparative meteorological investigation, which lasted several years. The majority of the data collected during the site selection campaigns will be made public in the course of the year 2010. Various factors needed to be considered in the site selection process. Obviously the "astronomical quality" of the atmosphere, for instance, the number of clear nights, the amount of water vapour, and the "stability" of the atmosphere (also known as seeing) played a crucial role. But other

  12. Novelty and spatio-temporal heterogeneity in the bacterial diversity of hypersaline Lake Tebenquiche (Salar de Atacama).

    Science.gov (United States)

    Demergasso, Cecilia; Escudero, Lorena; Casamayor, Emilio O; Chong, Guillermo; Balagué, Vanessa; Pedrós-Alió, Carlos

    2008-07-01

    Lake Tebenquiche is one of the largest saline water bodies in the Salar de Atacama at 2,500 m above sea level in northeastern Chile. Bacteria inhabiting there have to deal with extreme changes in salinity, temperature and UV dose (i.e., high environmental dissimilarity in the physical landscape). We analyzed the bacterioplankton structure of this lake by 16S rRNA gene analyses along a spatio-temporal survey. The bacterial assemblage within the lake was quite heterogeneous both in space and time. Salinity changed both in space and time ranging between 1 and 30% (w/v), and total abundances of planktonic prokaryotes in the different sampling points within the lake ranged between two and nine times 10(6) cells mL(-1). Community composition changed accordingly to the particular salinity of each point as depicted by genetic fingerprinting analyses (denaturing gradient gel electrophoresis), showing a high level of variation in species composition from place to place (beta-diversity). Three selected sites were analyzed in more detail by clone libraries. We observed a predominance of Bacteroidetes (about one third of the clones) and Gammaproteobacteria (another third) with respect to all the other bacterial groups. The diversity of Bacteroidetes sequences was large and showed a remarkable degree of novelty. Bacteroidetes formed at least four clusters with no cultured relatives in databases and rather distantly related to any known 16S rRNA sequence. Within this phylum, a rich and diverse presence of Salinibacter relatives was found in the saltiest part of the lake. Lake Tebenquiche included several novel microorganisms of environmental importance and appeared as a large unexplored reservoir of unknown bacteria. PMID:18347752

  13. Desert and desertification in Iran

    Science.gov (United States)

    Bahrami, M.

    2009-04-01

    One of the greatest environmental concerns in Iran as in other arid and semiarid countries is the transformation of once productive, or marginally productive, land to deteriorated land and soil unable to support plants and animals. Because the land becomes barren and dry, the process is described as desertification, which occurs as a sequence of events. The area of deserts in Iran is about 340,000 Km2 (less than one fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40 % of which is active sand dunes. Most of features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases. The deserts of Iran are generally classified in the subtropical, warm, arid and semiarid group, but the effect and presence of some geographical and geoclimatical factors such as height, vicinity to Indian Ocean and so on do some changes in climatic conditions and geographical features causing some local and regional differences in them. Geographically, two groups of deserts have been known in Iran: (1) Coastal deserts which, like a ribbon with variable width, stretch from extreme southeast to extreme southwest, at the north parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. This causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering to that of physical. (2) internal deserts, which rest in central, eastern and southeastern plateau of the country and in independent and semi dependent depressions. This situation, which is due to the surrounding high mountains, blocks humidity entry and causes the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert

  14. Extensional Basins in a Convergent Margin: Oligocene-Early Miocene Salar de Atacama and Calama basins, Central Andes

    Science.gov (United States)

    Jordan, T. E.; Mpodozis, C.; Blanco, N.; Pananont, P.; Dávila, F.

    2004-12-01

    The Salar de Atacama Basin (SdAB) is the largest and most persistent sedimentary basin of northern Chile, accumulating nonmarine sediment from Cretaceous to modern times. Its northwestern neighbor, the Calama, was a Cenozoic basin. Although SdAB was in the backarc zone early in the Andean orogeny, both are now forearc basins. Others demonstrated that the basins overlie anomalously cold, strong, and dense crust and lithosphere. We focus on an extensional Oligocene basin stage. Interpretation of the basin-controlling faults is based on seismic reflection studies supported by field relations. The SdAB is limited to the west by the NNE-trending, steeply east-dipping, Paciencia Fault (PF). The PF experienced 5-7 km of down-to-the-east offset during the Oligocene-early Miocene. Syntectonic strata, an arid succession of siliciclastics and evaporites, are asymmetric, with thicknesses of 5000 m and abundant halite adjacent to the PF, and of 1000 m with fine detrital clastic strata 25 km farther east. Relations in conglomeratic growth strata that overlap the PF also demonstrate normal displacement during sediment accumulation. Seismic data reveal that a buried normal fault with 1-1.5 km down-to-the-east displacement limits the western margin of the Oligocene-Miocene Calama siliciclastic basin fill. Regionally, Oligocene-early Miocene margin-parallel strike-slip deformation dominated northwest of the basins, contributing sinistral offset (West Fissure Fault) to the northern segment of the long-lived Domeyko Fault System. The new SdAB and Calama data reveal that a 20,000 km2 domain of extensional basins existed within the dominantly strike-slip region. Even if PF and the fault in the Calama Basin were transtensional, the proportion of extension to strike-slip displacement is much greater in these basins than elsewhere in northern Chile. Further study is required to understand what combination of factors caused this kinematic distinction as well as delayed the onset of CVZ

  15. complejidad en Chile

    Directory of Open Access Journals (Sweden)

    Miguel Alejandro Bustamante-Ubilla

    2015-01-01

    Full Text Available El presente estudio tiene por objetivo caracterizar el clima organizacional al interior de 2 hospitales dealta complejidad de Chile, determinando las dimensiones más y menos influyentes. Para su desarrollose aplicó un cuestionario que consta de 71 variables agrupadas en 14 dimensiones a una muestra de561 funcionarios. La interpretación de los resultados se realizó a través del análisis del valor prome-dio estandarizado y su confiabilidad ratificada mediante el alfa de Cronbach. A partir de lo anterior, sedeterminó que las dimensiones que influyen por encima del promedio fueron: identidad, motivaciónlaboral y responsabilidad; en tanto que las dimensiones que muestran un nivel de impacto por debajodel promedio resultaron ser: equipo y distribución de personas y material, administración del conflictoy comunicación.© 2015 Universidad ICESI. Publicado por Elsevier España, S.L.U. Este es un artículo Open Access bajo lalicencia CC BY (http://creativecommons.org/licenses/by/4.0/.

  16. The Ordovician Quebrada Grande Formation, Cordón de Lila (Antofagasta Region, northern Chile): stratigraphicand paleogeographic significance La Formación QuebradaGrande, del Ordovícico, Cordón de Lila (Región de Antofagasta, norte de Chile): significado estratigráfico y paleogeográfico

    OpenAIRE

    Javier González; Hans Niemeyer; Juan L. Benedetto; Edsel D Brussa

    2007-01-01

    The Cordón de Lila is located immediately to the south of the Salar de Atacama, in northern Chile. The geology of the Cordón de Lila is characterized by extensive outcrops of Early Paleozoic volcanic and sedimentary rocks (Cordón de Lila Igneous and Sedimentary Complex; CISL) that form the 'Arco magmático occidental' (AMO) which is intruded by a multiple suite of Middle Ordovician to Lower Silurian granitoids. In this contribution we report the results of a sedimentological and paleontologica...

  17. Severidad de caries y pérdida de dientes de una población pre-Hispánica del norte de Chile Caries severity and tooth loss in an ancient pre-Columbian culture in the north of Chile

    OpenAIRE

    I Urzúa Araya; R Cabello Ibacache; G. Rodríguez Martínez; S Gallardo Cortes; Sánchez González, J.; Hubbe, M.

    2012-01-01

    El conocer la historia natural de las patologías bucales sin intervenciones modernas, permite comparar el desarrollo de éstas con los datos actuales. Este estudio tiene como objetivo conocer la severidad de caries dental y de pérdida de dientes en una muestra de restos humanos de la cultura Atacameña (500 DC) en San Pedro de Atacama en el norte de Chile. Se estudiaron 139 restos humanos, en cada uno de ellos se realizó un examen clínico, consignado la información en una ficha individual donde...

  18. PARASITOS DE LOS ANIMALES DOMESTICOS EN CHILE

    OpenAIRE

    HECTOR ALCAINO; TEXIA GORMAN

    1999-01-01

    PARASITES OF DOMESTIC ANIMALS IN CHILE An up-to-date list of the parasites that have been identified in horses, cattle, sheep, goats, llamas, alpacas, pigs, dogs, cats, rabbits, chickens and pigeons in Chile, according to the studies performed at the University of Chile and other Universities and Institutes.

  19. China and Chile Signing Free Trade Agreement

    Institute of Scientific and Technical Information of China (English)

    Shen; Danyang

    2005-01-01

      Mr. Bo Xilai, Minister of Commerce of China, and Mr.Walker, Foreign Minister of Chile, signed the China-Chile FTA on behalf of their respective government on November 18, 2005. Chinese President Hu Jintao and Chile President Lagos attended the signing ceremony, according to a press release on the website of Network Center of MOFCOM.……

  20. China and Chile Signing Free Trade Agreement

    Institute of Scientific and Technical Information of China (English)

    Shen Danyang

    2005-01-01

    @@ Mr. Bo Xilai, Minister of Commerce of China, and Mr.Walker, Foreign Minister of Chile, signed the China-Chile FTA on behalf of their respective government on November 18, 2005. Chinese President Hu Jintao and Chile President Lagos attended the signing ceremony, according to a press release on the website of Network Center of MOFCOM.

  1. PARASITOS DE LOS ANIMALES DOMESTICOS EN CHILE

    Directory of Open Access Journals (Sweden)

    HECTOR ALCAINO

    1999-01-01

    Full Text Available PARASITES OF DOMESTIC ANIMALS IN CHILE An up-to-date list of the parasites that have been identified in horses, cattle, sheep, goats, llamas, alpacas, pigs, dogs, cats, rabbits, chickens and pigeons in Chile, according to the studies performed at the University of Chile and other Universities and Institutes.

  2. International Uranium Resources Evaluation Project (IUREP) national favourability studies: Chile

    International Nuclear Information System (INIS)

    Chile has an area of 740,760 square kilometers. The capital is Santiago. The country is 4,183 km. long and ranges from 22.5 to about 354 km. in width. Its chief topographic features para]lei each other - the Coastal Range, Andes Mountains and Central Valley. The Coastal Range rises to 2,130 meters in the north, but averages from 610 to 700 meters high generally. The range plunges into the Pacific Ocean far south of Valparaiso and reappears in the southern archipelagic islands. The Andes extend along nearly the entire length of Chile and contain 100 volcanoes. Andean peaks range mostly from 3,000 to 6,700 meters in elevation. In southern Chile the Andes are lower, and contain about a dozen major lakes. The mountains disappear in Chilean Patagonia, but reappear at Cape Horn. The Central Valley lies between the Coastal Range and the Andes, being best defined in the midland region as a 64 to 72 km sloping plain. It is the Chilean heartland with three-quarters of the country's population. Salt basins are found over much of northern Chile in the very arid desert, while the region south of the Gulf of Reloncavi consists of unpopulated islands, fjords, channels and heavily forested mountains. The Strait of Magellan, the Tierra del Fuego archipelago and a flat grassland area make up the extreme southern end of the country. Much of Chile is subject to flash floods, earthquakes, volcanic eruptions, landslides and avalanches. In September 1976 the Comision Chilena de Energia Nuclear (CCEN) was given exclusive rights to negotiate contracts with private companies for the exploration, development and mining of uranium and other radioactive minerals. The new law provides the CCEN with considerable flexibility in the terms of the contracts. Pre-964 owners of uranium deposits may reach agreements with foreign companies to mine the uranium, but since 1964 all uranium has belonged to the state. Uranium produced in the country can only be exported after Chile's needs have been met. The

  3. Stone structures in the Syrian Desert

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    An arid land, known as the Syrian Desert, is covering a large part of the Middle East. In the past, this harsh environment, characterized by huge lava fields, the "harraat", was considered as a barrier between Levant and Mesopotamia. When we observe this desert from space, we discover that it is crossed by some stone structures, the "desert kites", which were the Neolithic traps for the game. Several stone circles are visible too, as many Stonehenge sites dispersed in the desert landscape.

  4. Labelled water in desert survival patterns

    International Nuclear Information System (INIS)

    Tritiated water (3HOH) was used as a tracer to explain, at least in part, the survival of some plants and animals in the Namib Desert. Special attention is given to grass (Stipagrostis sabulicola), a variety of beetles, small desert mammals and the desert ostrich. The potential of doubly-labelled water (3HH18O and 2HH18O) in desert research is briefly mentioned

  5. Phytoremediation for Oily Desert Soils

    Science.gov (United States)

    Radwan, Samir

    This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

  6. Mirror illumination and spillover measurements of the Atacama Cosmology Telescope

    Science.gov (United States)

    Gallardo, Patricio; Dünner, Rolando; Wollack, Edward; Henriquez, Fernando; Jerez-Hanckes, Carlos

    2012-09-01

    The Atacama Cosmology Telescope (ACT) is a 6 m telescope designed to map the Cosmic Microwave Background (CMB) simultaneously at 145 GHz, 220 GHz and 280GHz. The receiver in ACT, the Millimeter Bolometer Array Camera, features 1000 TES bolometers in each band. The detector performance depends critically on the total optical loading, requiring the spillover contributions from the optics to be minimal. This inspired the use of a cold Lyot stop to limit the illumination of the primary and the use of guard rings surrounding the primary and secondary reflectors. Here, we present a direct measurement of the illumination aperture for both reflectors and of the attenuation level outside the main optical path. We used a 145 GHz, 1mW source and a chopper wheel to produce a time-varying signal with a broad beam profile. We sampled the response of the camera for different locations of the source, placed in front and beside the primary and secondary mirrors. The aperture of the primary was measured to be 5.72 ± 0.17m in diameter (95 ± 3% of its geometrical size), while the aperture of the secondary yielded 2 ± 0.12m in diameter. Both apertures are consistent with the optical design. Comparing to previous measurements of the beam solid angle from planet observations, we estimate an optical efficiency of 72.3 ± 4.8%. We found that the attenuation outside the primary aperture was -16 ± 2 dB, which is below the theoretical expectations, and -22 ± 1 dB outside the secondary aperture, which is consistent with simulations. These results motivated the extension of the baffles surrounding the secondary mirror, with the following reduction in detector optical loading from 2.24pW to 1.88 pW.

  7. The Atacama Cosmology Telescope: Data Characterization and Map Making

    Science.gov (United States)

    Duenner, Rolando; Hasselfield, Matthew; Marriage, Tobias A.; Sievers, Jon; Acquaviva, Viviana; Addison, Graeme E.; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John William; Barrientos, L. Felipe; Battistelli, Elia S.; Bond, J. Richard; Brown, Ben; Burger, Bryce; Chervenak, Jay; Calabrese, Erminia; Das, Sudeep; Devlin, Mark J.; Dicker, Simon R.; Doriese, W. Bertrand; Dunkley, Joanna; Essinger-Hileman, Thomas; Moseley, Harvey; Wollack, Ed

    2012-01-01

    We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% or the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 142h of data (11 TB for the 148 GHz band only), with a daily average of 10.5 h of observation. From these, 108.5 h were devoted to 850 sq deg stripe (11.2 h by 9 deg.1) centered on a declination of -52 deg.7, while 175 h were devoted to a 280 square deg stripe (4.5 h by 4 deg.8) centered at the celestial equator. We discuss sources of statistical and systematic noise, calibration, telescope pointing and data selection. Out of 1260 survey hours and 1024 detectors per array, 816 h and 593 effective detectors remain after data selection for this frequency band, yielding a 38 % survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-ordered data stream (TOD), is 32 muK square root of s in CMB units. Atmospheric brightness fluctuations constitute the main contaminant in the data and dominate the detector and noise covariance at low frequencies in the TOD. The maps were made by solving the lease squares problem using the Preconditioned Conjugate Gradient method, incorporating the details of the detector and noise correlations. Cross-correlation with WMAP sky maps as well as analysis from simulations reveal the our maps are unbiased at l > 300. This paper accompanies the public release of the 148 GHz southern stripe maps from 2008. The techniques described here will be applied to future maps and data releases.

  8. Mirror Illumination and Spillover Measurements of the Atacama Cosmology Telescope

    Science.gov (United States)

    Gallardo, Patricio; Dunner, Rolando; Wollack, Ed; Jerez-Hanckes, Carlos

    2012-01-01

    The Atacama Cosmology Telescope (ACT) is a 6 m telescope designed to map the Cosmic Microwave Background (CMB) simultaneously at 145 GHz, 220GHz and 280GHz, The receiver in ACT, the Millimeter Bolometer Array Camera, features 1000 TES bolometers in each band, The detector performance depends critically on the total optical loading, requiring the spmover contributions from the optics to be minimal. This inspired the use of a cold Lyot stop to limit the illumination of the primary and the use of guard rings surrounding the primary and secondary reflectors. Here, we present a direct measurement of the illumination aperture for both reflectors and of the attenuation level outside the main optical path. We used a 145 GHz, 1 m W source and a chopper wheel to produce a time-varying signal with a broad heam proflle, We sampled the response of the camera for different locations of the source, placed in front and beside the primary and secondary mirrors. The aperture of the primary was measured to be 5,72 plus or minus 0,17m in diameter (95 plus or minus 3% of its geometrical size), while the aperture of the secondary yielded 2 plus or minus 0.12m in diameter. Both apertures are consistent with the optical design. Comparing to previous measurements of the beam solid angle from planet observations, we estimate an optical efficiency of 72.3 plus or minus 4,8%. We found that the attenuation outside the primary aperture was -16 plus or minus 2dB, which is below the theoretical expectations, and -22 plus or minus 1 dB outside the secondary aperture, which is consistent with simulations. These results motivated the extension of the baffles surrounding the secondary mirror, with the following reduction in detector optical loading from 2,24 pW to 188pW.

  9. THE ATACAMA COSMOLOGY TELESCOPE: DATA CHARACTERIZATION AND MAPMAKING

    Energy Technology Data Exchange (ETDEWEB)

    Duenner, Rolando; Aguirre, Paula; Barrientos, L. Felipe [Departamento de Astronomia y Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Hasselfield, Matthew; Amiri, Mandana; Battistelli, Elia S.; Burger, Bryce [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Marriage, Tobias A.; Acquaviva, Viviana; Das, Sudeep [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Sievers, Jon; Appel, John William [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Addison, Graeme E.; Calabrese, Erminia [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Ade, Peter A. R. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Bond, J. Richard [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Brown, Ben [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Chervenak, Jay [Code 553/665, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Devlin, Mark J.; Dicker, Simon R. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); and others

    2013-01-01

    We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hr of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hr of observation. From these, 1085 hr were devoted to an 850 deg{sup 2} stripe (11.2 hr by 9. Degree-Sign 1) centered on a declination of -52. Degree-Sign 7, while 175 hr were devoted to a 280 deg{sup 2} stripe (4.5 hr by 4. Degree-Sign 8) centered at the celestial equator. The remaining 163 hr correspond to calibration runs. We discuss sources of statistical and systematic noise, calibration, telescope pointing, and data selection. For the 148 GHz band, out of 1260 survey hours and 1024 detectors in the array, 816 hr and 593 effective detectors remain after data selection, yielding a 38% survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-ordered data stream (TOD), is 32 {mu}K{radical}s in cosmic microwave background units. Atmospheric brightness fluctuations constitute the main contaminant in the data and dominate the detector noise covariance at low frequencies in the TOD. The maps were made by solving the least-squares problem using the Preconditioned Conjugate Gradient method, incorporating the details of the detector and noise correlations. Simulations, as well as cross-correlations with Wilkinson Microwave Anisotropy Probe sky maps on large angular scales, reveal that our maps are unbiased at multipoles l > 300. This paper accompanies the public release of the 148 GHz southern stripe maps from 2008. The techniques described here will be applied to future maps and data releases.

  10. THE ATACAMA COSMOLOGY TELESCOPE: DATA CHARACTERIZATION AND MAPMAKING

    International Nuclear Information System (INIS)

    We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hr of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hr of observation. From these, 1085 hr were devoted to an 850 deg2 stripe (11.2 hr by 9.°1) centered on a declination of –52.°7, while 175 hr were devoted to a 280 deg2 stripe (4.5 hr by 4.°8) centered at the celestial equator. The remaining 163 hr correspond to calibration runs. We discuss sources of statistical and systematic noise, calibration, telescope pointing, and data selection. For the 148 GHz band, out of 1260 survey hours and 1024 detectors in the array, 816 hr and 593 effective detectors remain after data selection, yielding a 38% survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-ordered data stream (TOD), is 32 μK√s in cosmic microwave background units. Atmospheric brightness fluctuations constitute the main contaminant in the data and dominate the detector noise covariance at low frequencies in the TOD. The maps were made by solving the least-squares problem using the Preconditioned Conjugate Gradient method, incorporating the details of the detector and noise correlations. Simulations, as well as cross-correlations with Wilkinson Microwave Anisotropy Probe sky maps on large angular scales, reveal that our maps are unbiased at multipoles l > 300. This paper accompanies the public release of the 148 GHz southern stripe maps from 2008. The techniques described here will be applied to future maps and data releases.

  11. Recording of ocean-climate changes during the last 2,000 years in a hypoxic marine environment off northern Chile (23°S Registro de cambios océano-climáticos durante los últimos 2000 años en un ambiente marino hipóxico en el norte de Chile (23°S

    Directory of Open Access Journals (Sweden)

    LUC ORTLIEB

    2000-06-01

    Full Text Available Atmosphere-ocean interactions are particularly strong along the Chile-Peru coast and largely account for the extreme aridity of the Atacama Desert. Near the center of the driest part of this coastal desert, we found that the embayment Bahía Mejillones constitutes an unusually favorable setting for the formation and subsequent preservation of a sedimentary record of the successive oceanographic conditions of the last few thousand years. This work deals with relative abundance of various bio-indicators, including fish scales, foraminifers and phytoplankton, with a centimetre-scale resolution, in several gravity cores taken from 80 to 120 m depth, in a low-oxygen environment. We use this information to document ocean-climate changes at decadal to centennial time scales in the region. Radiocarbon dating on the bulk organic-rich sediment provides the chronological framework for the observed paleoceanographic changes. We interpret that an episode of relatively warmer water, with a stratified water column and enhanced anoxic ( 0.3 ml l-1 O2 conditions at the bottom of the water column, may correspond to the Little Ice Age (16th to mid-19th centuries. During the first millennium of our era, two thin sedimentary layers which present similarities with the bed assigned to the warm episode are interpreted as possible remnants of very strong, or " mega " El Niño events. The study confirms that Bahía Mejillones sediments did record ocean-climate changes with a very high time-resolution, and thus deserve a closer attention to investigate the ocean-atmosphere interactions over the last few thousand yearsLas interacciones océano-atmósfera son particularmente fuertes a lo largo de la costa de Chile y Perú y explican en gran parte la extrema aridez del desierto de Atacama. Cerca del sector más seco del desierto costero, hemos encontrado que la bahía semi-cerrada de Bahía Mejillones constituye un sitio particularmente favorable para la formación y

  12. Physical and Geochemical Controls on the Structure and Function of Microbial Mat Communities at El Tatio Geyser Field, Chile

    Science.gov (United States)

    Myers, K. D.; Omelon, C. R.; Bennett, P.

    2013-12-01

    Cyanobacteria are important primary producers that form the basis of most hot spring microbial mat communities in waters between 30-73°C. Primary producers shape microbial mat communities by fixing the dissolved inorganic carbon (DIC) pool to organic carbon and providing nutrients for diverse microorganisms that perform a broad range of biogeochemical transformations. This study compares the microbial community structure and net primary productivity of cyanobacterially-based and non-cyanobacterially based microbial mats collected from the El Tatio Geyser Field, a high elevation geyser complex in the Andes Mountains in Region II, Chile. In addition to extreme conditions imparted by high elevation and its location in the Atacama Desert, El Tatio has a suite of extreme geochemical stressors for life, including high arsenic as As(III) and As(V) (0.4-0.6 mM). El Tatio also has unusually low concentrations of DIC in some streams (0.1-0.3 mM), low enough to severely limit primary production in microbial mats. In contrast to other geothermal sites around the world where microbial diversity is controlled primarily by temperature, observations of unusual patterns in microbial mat composition in low-DIC streams at El Tatio suggest alternate controls their distribution. For instance, we observe less biomass in low-DIC streams compared to nearby high DIC streams, and less biomass in high temperature regions of low-DIC streams, compared to low-temperature locations that are dominated by cyanobacteria. To further investigate these patterns, a field assay was conducted to compare carbon assimilation, the relative importance of photo- and chemoautotrophy, and bacterial 16S rRNA sequence abundance at two distinct sites along a low-DIC stream. Water temperature at the upstream site measured 60°C, is dominated by high As(III), and is composed of sparse, red-colored mat material, whereas the downstream site measured a water temperature of 40°C, is dominated by high As(V), and is

  13. Physicochemical and Biological Zonation of High Temperature Silica and Arsenic-Rich Streams at El Tatio Geyser Field, Chile

    Science.gov (United States)

    Myers, K. D.; Engel, A. S.; Omelon, C. R.; Bennett, P.

    2012-12-01

    El Tatio Geyser Field is a geothermal complex comprised of three main basins in the northern Atacama Desert (Region II), Chile. Located at 4400 m elevation in the Andes Mountains it experiences intense solar radiation and a UV flux 33% higher than at Yellowstone National Park (Wyoming). Local boiling point is 86°C, and geothermal waters are Na-Ca-Cl type with circumneutral pH, high dissolved silica, and high dissolved arsenic concentrations (30-50 ppm). Most thermal features contain scant dissolved inorganic carbon (DIC as CO2(aq) + HCO3- + CO3-2). There is a conspicuous lack of microbial mat development in temperature zones where thick mats are seen at other geothermal sites. This investigation focused on understanding the physicochemical controls on microbial diversity that lead to microbial mat colonization and development within specific thermal regions of the geothermal features. Temperature surveys were done at three geothermal features where microbial mats and water chemistry were sampled, and a high-resolution thermal survey was conducted at one geyser orifice through the discharge channel where chemistry and mineralogy have been characterized, and microbial diversity was evaluated from 16S rRNA gene sequences. At the main study geyser, the stream is 0.25 m wide near its source, and for the first 20 m, the discharge stream is constrained by a solid silica bank with a mineralized channel bottom and no obvious microbial mat development. Temperatures decrease from ~86°C to ~67°C. In this zone sparse filaments were observed on rare sediments below the water surface consisting of ~80% Thermus spp. with rare uncultured Chloroflexus spp. and Candidate Division OP1 sequences. At 12 m, visible red-orange mat development starts on the sides of the channel where bulk water temperature is 67°C. Photosynthetic Chloroflexus spp. dominate red-orange filaments that form the first conspicuous mats (between 43-88% of the 16S rRNA sequences from different samples), with

  14. Escalas de producción en economías mineras: El caso de Chile en su dimensión regional

    Directory of Open Access Journals (Sweden)

    Nathaly Rivera

    2014-09-01

    Full Text Available Una proporción importante de la producción de cobre en Chile está geográficamente concentrada en dos regiones: Antofagasta y Atacama. A pesar de la evolución positiva del precio del cobre, el ingreso promedio de estas localidades ha presentado variaciones. Así, durante periodos de incrementos en el precio del cobre el ingreso promedio de Atacama ha aumentado, mientras que lo mismo no ha ocurrido en Antofagasta· Este trabajo analiza esta diferencia a partir del rol de las escalas de producción en el sector minero. Utilizando un análisis de sensibilidad para un modelo insumo-producto desagregado, se calculan encadenamientos y multiplicadores por escalas de producción a nivel regional. Esta estrategia permite identificar y cuantificar el impacto de cada escala de producción, confirmando efectos heterogéneos de la minería sobre la producción e ingreso local, aspectos que adquieren especial relevancia al analizarse la política minera actual en Chile.

  15. The biomethane potential in Chile

    International Nuclear Information System (INIS)

    Within the last decade natural gas gained considerable importance in Chile. The contribution of natural gas within the energy system will increase in the future by predicted 3.6% annually until the year 2015. Due to limited resources within its own country, the energy system of Chile depends on natural gas imports preferential from Argentina. Therefore, the aim of several stakeholders from policy and industry is to reduce the share of imported primary energy within the overall energy system. In order to reach this goal, the use of domestic resources and particularly the utilisation of biomass as one of the most important renewable sources of energy in Chile could play an important role. Against this background, the goal of this paper is the analysis of the technical potentials of biomethane as a substitute for natural gas. For the production of biomethane the anaerobic or bio-chemical (i.e. Biogas) as well as the thermo-chemical conversion pathways (i.e. Bio-SNG) are considered. The results of this analysis show that biomass converted to biomethane is a promising energy provision option for Chile and it contributes to the reduction of greenhouse gas emissions

  16. Corporate Governance Country Assessment : Chile

    OpenAIRE

    World Bank

    2003-01-01

    Chile's equity market is fairly large and successful. The market capitalization of the 249 listed firms represented 89 percent of GDP at year-end, 2001. Corporate ownership is concentrated and pyramid structures are common. Business groups/conglomerates are the predominant corporate form. Institutional investors, especially pension funds, are active equity investors. The Securities Market ...

  17. Socialisme i Chile efter Pinochet

    DEFF Research Database (Denmark)

    Cristoffanini, Pablo Rolando

    2008-01-01

    Chile bliver ofte præsenteret som et paradigme for resten af det latinamerikanske kontinent: Et land med høj økonomisk vækst og politisk stabilitet. Landet har endda haft to socialistiske præsidenter siden 2000, den sidste den første kvindelige præsident. Succeshistorien har en bagside: De social...

  18. Fold and thrust belt structures and strike-slip faulting at the SE margin of the Salar de Atacama basin, Chilean Andes

    Science.gov (United States)

    Kuhn, Dirk

    2002-07-01

    A tectonic reinterpretation is reported for the southeastern margin of the Salar de Atacama basin of northern Chile. Detailed structural mapping revealed the presence of an east vergent thin-skinned fold and thrust belt affecting Oligocene-Miocene Paciencia Group rocks and the overlying Plio-Pleistocene volcanic rocks. Along-strike segmentation of the main fold implies local foreland influence on footwall ramp geometry leading to local thrust sheet rotation. To the east the adjacent western slope of the Western Cordillera displays two different structural domains, probably controlled by preexisting basement structures. The southern domain comprises two N-S oriented sigmoidal belts of linear arranged pressure ridges, indicating left-lateral transpression. In contrast, the northern domain is characterized by east vergent fold and thrust belt structures and reactivated NW-SE striking sinistral strike-slip faults, governing clockwise block rotations. An indenter-driven deformation model is proposed to explain sinistral transpression and clockwise block rotations around vertical axes. This variant of a small-block rotation mechanism is discussed in the context of oroclinal bending of the central Andes, emphasizing the significance of ancient structures in controlling rotations.

  19. Acuicultura Insostenible en Chile (Unsustainable aquaculture in Chile

    Directory of Open Access Journals (Sweden)

    Sommer, Marcos

    2009-03-01

    Full Text Available ResumenLa acuicultura en Chile sólo será alternativa a la pesca si se consigue llevar su producción a parámetros de sostenibilidad, no solamente económica sino, fundamentalmente, ambiental. Con un esfuerzo dirigido hacia medidas legislativas y de control, e investigación aplicada, podríamos acercarnos a una acuicultura ambientalmente sostenible.

  20. Reestablecimiento de Choromytilus chorus (Molina, 1782 (Bivalvia: Mytilidae en el norte de Chile Reestablishment of Choromytilus chorus (Molina, 1782 (Bivalvia: Mytilidae in northern Chile

    Directory of Open Access Journals (Sweden)

    Miguel Avendaño

    2011-07-01

    Full Text Available Hasta fines del siglo pasado no existían registros de la presencia de Choromytilus chorus al norte de los 23°S, pese a antecedentes que señalaban su existencia en épocas pasadas. Ciertos cambios relacionados con las masas de agua costeras de esta zona, habrían generado la ausencia o escasez que presentaba el entorno costero actual. Sin embargo, hace una década atrás, su presencia en el norte de Chile, comienza a tener connotación pesquera. En el presente trabajo se confirma su reestablecimiento en las regiones de Antofagasta y Tarapacá, mediante prospecciones realizadas en seis lugares donde se registró su presencia, así como mediante la captación de semilla en colectores suspendidos. Se indica interacción con Aulacomya ater, a la cual ha desplazado a estratos más profundos, mientras que su reestablecimiento, iniciado en las regiones de Atacama y Antofagasta, y que se amplió posteriormente a la región de Tarapacá; permite postular la hipótesis que la dinámica de estos bancos, respondería a una estructura de metapoblación, dado el sistema de corrientes y vientos que predominan en la zona norte, permitiendo la advección larval de poblaciones existentes en la región de Coquimbo.Despite indications of its presence in past ages, until the end of the last century, no records showed Choromytilus chorus north of 23°S. Certain changes related to coastal water masses in the zone could be responsible for the present lack or scarcity of this species in the coastal area. However, a decade ago, this species appeared in northern Chile in the context of fisheries. This study confirms the re-establishment of C. chorus in the Antofagasta and Tarapaca regions through surveys at six sites where the species had been registered and spat collection using suspended collectors. This species has interacted with Aulacomya ater, displacing it towards deeper habitats. The re-establishment of C. chorus began in the Atacama and Antofagasta regions and

  1. Sobre la presencia de Paraptenodytes y Palaeospheniscus (Aves: Sphenisciformes en la Formación Bahía Inglesa, Chile On the precense of Paraptenodytes y Palaeospheniscus (Aves: Sphenisciformes on the Bahia Inglesa Formation, Chile

    Directory of Open Access Journals (Sweden)

    MARTÍN F CHÁVEZ

    2007-06-01

    Full Text Available El presente comentario fue motivado por el artículo de Acosta-Hospitaleche & Canto (2005 y de la observación directa de algunos especímenes de Spheniscidae previamente reportados para la Formación Bahía Inglesa, en la región de Atacama, Chile. La falta de caracteres morfológicos que permitan la diferenciación con el género Spheniscus y de restos diagnósticos asociados, descartan la asignación de materiales craneales a Palaeospheniscus. Igualmente no es posible corroborar la asignación de especímenes a Paraptenodytes, sugiriéndose el uso de Spheniscidae indet. aff. Paraptenodytes para un tarsometatarso aislado. Se sugiere también el uso de Spheniscus spp. para los especímenes previamente referidos a S. cf. chilensis y S. aff. humboldti. De este modo, el número de pingüinos registrados en la formación se reduce de nueve a sieteThe present comment was motivated by the article by Acosta-Hospitaleche & Canto (2005, and from the direct observation of some specimens of Sphenicidae previously reported for the Bahia Inglesa Formation, in the Atacama region, Chile. The lack of morphological characters that they allow the differentiation with the genus Spheniscus and of associate diagnostic remains discard the assignment of cranial materials to Palaeospheniscus. Equally it is not possible to corroborate the assignment of specimens to Paraptenodytes, being suggested the use of Spheniscidae indet. aff. Paraptenodytes for an isolated tarsometatarsus. It is also suggested the use of Spheniscus spp. for the specimens previously referred to S. cf. chilensis and S. aff. humboldti. This way, the number of penguins registered in the formation decreases from nine to seven

  2. Personajes fuera de lugar: antropomorfos tardíos en el arte rupestre del norte semiárido de Chile Images out of place: late period antropomorphous figures in the rock art of central Chile

    Directory of Open Access Journals (Sweden)

    Andrés Troncoso

    2011-07-01

    Full Text Available Los personajes con vestimenta son una de las representaciones rupestres más conocidas del noroeste argentino y el norte de Chile, y su presencia en ambas áreas es un indicador de la importante dinámica de interacción ocurrida durante el período Tardío entre ambos espacios. Una variedad de estos personajes son los antropomorfos con cuerpos de lados cóncavos (sensu Montt 2005, los que en ocasiones se representan asociados a escutiformes santamarianos. Si bien se ha planteado que su distribución meridional por la vertiente andina occidental no traspasa el área de San Pedro de Atacama (Montt 2005, en este trabajo presentamos tres diseños antropomorfos con cuerpo de lados cóncavos reconocidos en el arte rupestre del valle de Illapel (30° LS, Provincia del Choapa, Norte Semiárido de Chile. En particular, se establece un análisis formal de estos diseños y se los compara con aquellos reconocidos en zonas más septentrionales, para luego discutir su cronología y evaluar las implicancias de su presencia en espacios tan alejados a su área de distribución original, registro que se asocia, en la región, a la circulación de diseños establecida por el Tawantinsuyu.Anthropomorphous figures with clothing stand out among the most frequent representations in the rock art of Northwestern Argentina and Northern Chile. Their ubiquity in both areas has been considered as an indicator of the dynamics of interregional interaction during late prehistory. Antropomorphous with concave sides (sensu Montt 2005 are but one expression of these popular type of representations, and at least in some cases are associated with "shield-man" of the Santa María style. Even though it has been stated previously that for the western Cordillera de los Andes the southernmost dispersion of this type of anthropomorphous figure is the San Pedro de Atacama area (Montt 2005, in this paper we present three such figures recently recorded in the rock art of the Illapel valley

  3. [The epidemiological transition in Chile].

    Science.gov (United States)

    Albalá, C; Vio, F; Robledo, A; Icaza, G

    1993-12-01

    Aiming to describe the place that Chile has in the epidemiological transition, a descriptive study of the changes in demographic and epidemiological profiles of the country during the last 30 years is presented. The important decrease in general and child mortality rates, that has lead to an increase in life expectancy and ageing of the population, is emphasized. A 82% reduction in the proportion of deaths among less than one year old children and a 62% increase in mortality among people 65 years or older is observed. In agreement with these changes, non transmissible chronic diseases appear as the principal cause of mortality (65% of all deaths). However, regarding morbidity, an increase in digestive infectious and sexually transmitted diseases and a decrease in immuno-preventable diseases, excepting measles, is noted. It is concluded that, according to mortality, Chile is in a post transition stage, but there is persistence of some infectious diseases, typical of a pre-transition stage. PMID:8085073

  4. A new species of Eccopsis Zeller (Lepidoptera, Tortricidae from the coastal valleys of northern Chile, with the first continental record of E. galapagana Razowski & Landry

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2011-06-01

    Full Text Available A new species of Eccopsis Zeller (Lepidoptera, Tortricidae from the coastal valleys of northern Chile, with the first continental record of E. galapagana Razowski & Landry. Eccopsis Zeller, 1852 is reported for the first time from Chile. Eccopsis razowskii Vargas, n. sp. is described and illustrated based on specimens reared from larvae collected on native Acacia macracantha Willd. (Fabaceae in the coastal valleys of the northern Chilean desert. Eccopsis galapagana Razowski & Landry, 2008, previously known only from the Galapagos Islands, Ecuador, is recorded for the first time from continental South America. Larvae of the latter were collected in northern Chile feeding on Prosopis alba Griseb (Fabaceae.Uma nova espécie de Eccopsis Zeller (Lepidoptera, Tortricidae dos valles litorais do norte do Chile, e o primeiro registro continental de E. galapagana Razowski & Landry. Eccopsis Zeller (Lepidoptera, Tortricidae é registrado pela primeira vez para o Chile. Eccopsis razowskii Vargas, n. sp. é descrita e ilustrada com base em espécimes criados de larvas colectadas em Acacia macracantha Willd. (Fabaceae nos vales litorais do deserto do norte do Chile. Eccopsis galapagana Razowski & Landry, 2008, conhecida previamente das Ilhas Galápados, Equador, é registrada pela primeira vez para SulAmérica continental. Suas larvas foram coletadas em Prosopis alba Griseb (Fabaceae.

  5. Miedo y represionpolitica en Chile

    OpenAIRE

    Amado M. Padilla; Lillian Comas Díaz

    1987-01-01

    This paper describes a human rights fact-finding mission to Chile concerned with the use of psychological techniques employed in offlcia- Uy sactioned torture and repressíon, Meetings and interviews were conducted with representatives of many organízatíons working with víctima of governrnental repression including the Chílean Psychological Assocíation. Fear and repression wene found to be widespread among all socioeconomic segments of the population. Physical and psychologic...

  6. Mineralogía y evolución de las salmueras madres en el yacimiento de nitratos Pedro de Valdivia, Antofagasta, Chile

    Directory of Open Access Journals (Sweden)

    Juan J. Pueyo

    1998-07-01

    disposición rellenando fisuras (y porosidades, la casi ausencia de crecimientos desplazativos (configurando nódulos o enterolitos y de otras estructuras características de las evaporitas.ABSTRACT Mineralogy and parental brine evolution in the Pedro de Valdivia nitrate deposit, Antofagasta,Chile.The Chilean nitrate deposits have been formed by a complex paragenesis of saline minerals that infill the porosity and open spaces of different country rocks. The study of the mineral infilling sequences in the rock porosities at the Pedro de Valdivia deposit has enabled to gain information about the evolution of the parental brines of the saline (nitrate bearing paragenesis. This evolution is revealed by the precipitation of a sequence of progressively more soluble minerals: silicates (zeolites; calcite; Ca-, Na-, (K- and Mg-sulphates; Na- and KMg-nitrate-sulphates; nitratine; and small amounts of iodates, Na- and KMg-iodate-sulphates, chromates, borates and perchlorates. Two specific trends have been distinguished in the general sequence. A Na- trend characterised by the association glauberite-darapskite-(hectorfloresite, and a K-Mg-Na- trend related to bloedite-polyhalite-humberstonite-niter-(fuenzalidaite. Parental brines of the deposit were Oligocene-Miocene (but older that 6 Ma the age of the mineralisation. The main physiographic features were similar to the recent ones in this period, the climate being more humid. The genesis of the parental brines of the Chilean nitrate deposits is assumed to include thermal processes and recycling by leaching of previous salts formed in the arid environment of the Atacama Desert. Evaporation has also been involved in their genesis. It is the only mechanism effective enough to saturate the brines in very soluble minerals. Nevertheless, the nitrate ores cannot be considered as true evaporites owing to their arrangement infilling veins (and porosities and the almost complete absence of displacive growths (as nodules or enterolithes and

  7. Classification of thermophilic actinobacteria isolated from arid desert soils, including the description of Amycolatopsis deserti sp. nov.

    Science.gov (United States)

    Busarakam, Kanungnid; Brown, Ros; Bull, Alan T; Tan, Geok Yuan Annie; Zucchi, Tiago D; da Silva, Leonardo José; de Souza, Wallace Rafael; Goodfellow, Michael

    2016-02-01

    The taxonomic position of 26 filamentous actinobacteria isolated from a hyper-arid Atacama Desert soil and 2 from an arid Australian composite soil was established using a polyphasic approach. All of the isolates gave the diagnostic amplification product using 16S rRNA oligonucleotide primers specific for the genus Amycolatopsis. Representative isolates had chemotaxonomic and morphological properties typical of members of the genus Amycolatopsis. 16S rRNA gene analyses showed that all of the isolates belong to the Amycolatopsis methanolica 16S rRNA gene clade. The Atacama Desert isolates were assigned to one or other of two recognised species, namely Amycolatopsis ruanii and Amycolatopsis thermalba, based on 16S rRNA gene sequence, DNA:DNA relatedness and phenotypic data; emended descriptions are given for these species. In contrast, the two strains from the arid Australian composite soil, isolates GY024(T) and GY142, formed a distinct branch at the periphery of the A. methanolica 16S rRNA phyletic line, a taxon that was supported by all of the tree-making algorithms and by a 100 % bootstrap value. These strains shared a high degree of DNA:DNA relatedness and have many phenotypic properties in common, some of which distinguished them from all of the constituent species classified in the A. methanolica 16S rRNA clade. Isolates GY024(T) and GY142 merit recognition as a new species within the A. methanolica group of thermophilic strains. The name proposed for the new species is Amycolatopsis deserti sp. nov.; the type strain is GY024(T) (=NCIMB 14972(T) = NRRL B-65266(T)). PMID:26809280

  8. {U}/{Pb} geochronology and significance of Late Permian ignimbrites in Northern Chile

    Science.gov (United States)

    Breitkreuz, Christoph; Van Schmus, W. R.

    1996-11-01

    {U}/{Pb} zircon ages of four ignimbrite samples from a Late Paleozoic volcaniclastic succession in northern Chile are presented. The 2 km thick succession consists of the Peine Fm. and the overlying Cas Fm., which crop out at the eastern margin of the Salar de Atacama near the village of Peine. One sample was collected from the oldest ignimbrite of the succession (Lower Member of the Peine Fm.); the other three samples were collected from the Middle Member of the Cas Fm. and its assumed equivalents. The {206Pb }/{238U } ages of all samples overlap within their analytical uncertainties, which results in a best estimate of 248 ± 3 Ma (Late Permian: Harland, 1990) for deposition of the entire succession. The age for the stratigraphically older sample is statistically indistinguishable from the other three samples, so that the depositional interval could have been less than 1 million years; maximum errors in the data allow that the Peine and Cas Fms. could have formed during a time span of 6 Ma. The data provide tight constraints on the age of these units, part of which formed in the Lanquir Caldera Complex. They also have implications for the stratigraphy and paleoclimatic models of the Southern Central Andes during the Late Permian. Although the zircon fractions analyzed here document Late Permian ages, they show varying amounts of inheritance of early Paleoproterozoic (to Late Archean?) zircons and also indicate the incorporation of ca. 2.5 Ga initial common lead to varying degrees. This and results from other studies in the area lead us to infer the existence, at least during the Paleozoic, of Precam-brian basement located below the Salar de Atacama area.

  9. Network topology of the desert rose

    Directory of Open Access Journals (Sweden)

    Sigmund Mongstad Hope

    2015-09-01

    Full Text Available Desert roses are gypsum crystals that consist of intersecting disks. We determine their geometrical structure using computer assisted tomography. By mapping the geometrical structure onto a graph, the topology of the desert rose is analyzed and compared to a model based on diffusion limited aggregation. By comparing the topology, we find that the model gets a number of the features of the real desert rose right, whereas others do not fit so well.

  10. Network topology of the desert rose

    Science.gov (United States)

    Hope, Sigmund; Kundu, Sumanta; Roy, Chandreyee; Manna, Subhrangshu; Hansen, Alex

    2015-09-01

    Desert roses are gypsum crystals that consist of intersecting disks. We determine their geometrical structure using computer assisted tomography. By mapping the geometrical structure onto a graph, the topology of the desert rose is analyzed and compared to a model based on diffusion limited aggregation. By comparing the topology, we find that the model gets a number of the features of the real desert rose right, whereas others do not fit so well.

  11. Sistema de salud de Chile The health system of Chile

    OpenAIRE

    Víctor Becerril-Montekio; Juan de Dios Reyes; Annick Manuel

    2011-01-01

    En este trabajo se describe el sistema de salud de Chile, incluyendo su estructura, financiamiento, beneficiarios y recursos físicos, materiales y humanos de los que dispone. Este sistema está compuesto por dos sectores, público y privado. El sector público está formado por todos los organismos que constituyen el Sistema Nacional de Servicios de Salud y cubre aproximadamente a 70% de la población, incluyendo a los pobres del campo y las ciudades, la clase media baja y los jubilados, así como ...

  12. Chile : Household Risk Management and Social Protection

    OpenAIRE

    World Bank, (WB)

    2004-01-01

    This report is part of the World Bank's advisory and analytical assistance to the Government of Chile. The report examines whether Chile has a social protection "system" - broadly defined to include policy interventions, public institutions, and the regulation of private institutions that lower the welfare costs of adverse shocks to income from job loss and extended unemployment, health ep...

  13. Earthquake engineering research program in Chile

    Science.gov (United States)

    Saragoni, G. R.

    1982-01-01

    Earthquake engineering research in Chile has been carried out for more than 30 years. Systematic research is done at the university of Chile in Santiago. Other universities such as the Catholic University, university of Concepcion, and the Federico Santa Maria Technical University have begun to teach and conduct research in earthquake engineering in recent years. 

  14. Fog Collection and Sustainable Architecture in Atacama Coast

    Science.gov (United States)

    Suau, C.

    2010-07-01

    It is imperative to integrate renewable energy and climate into zero-carbon buildings in arid lands, particularly when it is reinforced by natural and social science-based innovation in natural and built environs. The aim is twofold: On one hand, to establish potential natural and urban habitats and their yields required in different scales of intervention and, on another hand, augment rate and yield of fog collection used for drinking and irrigation in chosen locations. The purpose of this study is to integrate zero-carbon energy, landscape and sustainable architecture as a whole and thus envision potential inhabitation through self-sufficient space-frame configurations along the coast of Tarapacá Region in Chile. In a sequential way, this study distinguishes three scales of interventions: A. Territorial scale. It consists of rural and natural zones along the shore of Tarapacá Region: Fog oases, creeks or corridors. The strategic allocation of large fog collectors can bring local agriculture back and thus stop rural emigration; and also repair existing fragile ecosystems in several fog oases by harvesting and distributing mainly crop water. B. Local scale. The space-frame fog collectors are allocated in Alto Patache (fog oasis) and Iquique city (low-income sprawl of Alto Hospicio). These artefacts can supply both water and electricity to small communities through forestation, sustainable micro-agriculture and complementary electrification. C. Domestic scale. It consists of the design of autonomous housing configuration based in polygonal space-frames. This inhabitable unit is modular, deployable and lightweight; with an adjustable polyvalent membrane which performs as water repellent skin (facing South and SW winds) and shading device facing Equator. In addition, a domestic wind turbine is installed within the structural frame to provide autonomous electrification. Water collector, filtering (purification) and irrigation network is designed with available

  15. SSALMON - The Solar Simulations for the Atacama Large Millimeter Observatory Network

    CERN Document Server

    Wedemeyera, S; Brajsa, R; Barta, M; Hudson, H; Fleishman, G; Loukitcheva, M; Fleck, B; Kontar, E; De Pontieu, B; Tiwari, S; Kato, Y; Soler, R; Yagoubov, P; Black, J H; Antolin, P; Gunar, S; Labrosse, N; Benz, A O; Nindos, A; Steffen, M; Scullion, E; Doyle, J G; Zaqarashvili, T; Hanslmeier, A; Nakariakov, V M; Heinzel, P; Ayres, T; Karlicky, M

    2015-01-01

    The Solar Simulations for the Atacama Large Millimeter Observatory Network (SSALMON) was initiated in 2014 in connection with two ALMA development studies. The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful new tool, which can also observe the Sun at high spatial, temporal, and spectral resolution. The international SSALMONetwork aims at coordinating the further development of solar observing modes for ALMA and at promoting scientific opportunities for solar physics with particular focus on numerical simulations, which can provide important constraints for the observing modes and can aid the interpretation of future observations. The radiation detected by ALMA originates mostly in the solar chromosphere - a complex and dynamic layer between the photosphere and corona, which plays an important role in the transport of energy and matter and the heating of the outer layers of the solar atmosphere. Potential targets include active regions, prominences, quiet Sun regions, flares. Here, we give a...

  16. First remarks on the nesting biology of Hypodynerus andeus (Packard (Hymenoptera, Vespidae, Eumeninae in the Azapa valley, northern Chile

    Directory of Open Access Journals (Sweden)

    Felipe Méndez-Abarca

    2012-06-01

    Full Text Available First remarks on the nesting biology of Hypodynerus andeus (Packard (Hymenoptera, Vespidae, Eumeninae in the Azapa valley, northern Chile. Some aspects about the nesting biology of the potter wasp Hypodynerus andeus (Packard, 1869 are reported for the first time. Observations were carried out at the Azapa valley, coastal desert of northern Chile. A total of sixty nests were collected and examined, each composed by 1-14 cells, most of them found attached to concrete lamp posts. The only preys recorded in the cells were Geometridae (Lepidoptera caterpillars and the presence of the parasitoid Anthrax sp. (Diptera, Bombyliidae was also recorded. A number of arthropods belonging to different groups, mainly spiders, were found occupying empty nests.

  17. New species of the spider genera Aysenia and Aysenoides from Chile and Argentina: description and phylogenetic relationships (Araneae: Anyphaenidae, Amaurobioidinae).

    Science.gov (United States)

    Laborda, Alvaro; Ramírez, Martín J; Pizarro-Araya, Jaime

    2013-01-01

    New spider species of the genera Aysenia Tullgren and Aysenoides Ramírez are described and their phylogenetic relationships discussed. The new species Aysenia paposo, from the coastal desert in northern Chile is sister to Aysenia araucana Ramírez. The diagnosis of Aysenia araucana is updated and new somatic variability is reported for the species. We present new records for other species of Aysenia and Aysenoides. The new species Aysenoides simoi, from temperate forests in Chile and adjacent Argentina is sister to Aysenoides nahuel. The phylogenetic analysis confirmed the monophyly of both genera. The support values of the genera are relatively high, but some internal branches show low support values. The genus Aysenia is supported by three synapomorphies, two of these from leg spination and one from the male genitalia. Aysenoides is supported by three synapomorphies from male and female genitalia. PMID:25277558

  18. Sistema de salud de Chile

    OpenAIRE

    Víctor Becerril-Montekio; Juan de Dios Reyes; Annick Manuel

    2011-01-01

    En este trabajo se describe el sistema de salud de Chile, incluyendo su estructura, financiamiento, beneficiarios y recursos físicos, materiales y humanos de los que dispone. Este sistema está compuesto por dos sectores, público y privado. El sector público está formado por todos los organismos que constituyen el Sistema Nacional de Servicios de Salud y cubre aproximadamente a 70% de la población, incluyendo a los pobres del campo y las ciudades, la clase media baja y los jubilados, así como ...

  19. The biological factors influence on the conversion of mineral components of Extremely Arid Desert Soils (Kazakhstan)

    Science.gov (United States)

    Kutovaya, Olga; Vasilenko, Elena; Lebedeva, Marina; Tkhakakhova, Azida

    2013-04-01

    Extremely arid soils of stony deserts (hamadas) along the southern periphery of the Ili Depression are considered to be analogous to extremely arid soils of Mongolia, also named as "ultra-arid primitive gray-brown soils." In general, the morphology of extremely arid soils of hamadas in the Ili Depression is similar to that of the soils of stony deserts in other parts of the world, including the Gobi, Atacama, and Tarim deserts. The diagnostics of the active communities of microorganisms were performed according to the method of Rybalkina-Kononenko. The exact identification of the living forms of microorganisms to the species level is not always possible with the use of this method. However, it allows us to study the physiological role of the microorganisms and their ecological functions, including the relationships with the soil matrix and other organisms. In particular, it is possible to estimate the contribution of the microorganisms to the transformation of mineral soil components. The obtained materials allow us to conclude that the extremely arid desert soils are characterized by the very high biological activity during short periods of the increased soil moistening after rare and strong rains. The diversity of living forms is very considerable; both prokaryotes (cyanobacteria, actinomycetes, and iron bacteria) and protists (green algae, diatoms, and dinoflagellates) are developed in the soil. Thus, during a short period after the rains, these microorganisms pass from the stage of anabiosis to the stage of active growth and reproduction. Then, upon drying of the soil, the biotic activity of the soil slows down and, finally, terminates. The organisms remain in the state of anabiosis until the next rain. During the period of active growth, the microorganisms compose a specific consortium of different species and exert a profound impact on the soil properties. They participate in the transformation of the soil minerals with the formation of amorphous substances

  20. The Atacama Cosmology Telescope: Beam Measurements and the Microwave Brightness Temperatures of Uranus and Saturn

    OpenAIRE

    Hasselfield, Matthew; Moodley, Kavilan; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dünner, Rolando; Fowler, Joseph W.; Gallardo, Patricio; Gralla, Megan B.; Hajian, Amir; Halpern, Mark; Hincks, Adam D.; Marriage, Tobias A.; Marsden, Danica

    2013-01-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilo-pixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty, to derive window functions relevant for angular power spect...

  1. Strategies of desert locust control

    International Nuclear Information System (INIS)

    Full text: The desert locust can infest an area from Mauritania to India and roughly from the Mediterranean to the Equator. Plagues with many swarms of adults and very many bands of hoppers are separated by recessions when most of the locusts are scattered and confined to the arid central belt. Widespread and heavy rain in the recession area may lead to outbreak breeding with 'patches' of hoppers. This may be followed by an upsurge during which successful breeding occurs in areas to which the adults of successive generations migrate. Further population increases leads to a plague. In spite of recent studies, the value of the damage caused by the desert locust is not known and it is not clear whether the control costs balance the prevented damage. But the impact on individual farmers may be devastating. Local crop protection is not feasible and financial compensation is difficult. However, the main importance of the desert locust is 'political' since swarms are dramatic and also migrate between countries. The current strategy is to prevent plagues by control of the outbreak or the early upsurge despite the lack of field evidence that this is effective and theoretical studies that suggest it is not. Moreover, several brief plagues have occurred. The adherence to a preventative strategy, the irregular occurrence of plagues and the fact that even during a plague many countries will escape has led to plague crisis management. During plagues aid, usually in the form of pesticide and aircraft, has been supplied by donors with no adequate assessment of the need or of the capacity of the recipient country to use what is supplied. Much pesticide has remained after plagues, creating a difficult disposal problem. Research and development has concentrated on survey data processing and forecasting with GIS, improved survey and application techniques with GPS, barrier applications with new persistent pesticides, use of mycopesticides and IGRs, and environmental monitoring. The

  2. EL RACISMO AMBIENTAL EN CHILE

    Directory of Open Access Journals (Sweden)

    MATÍAS MEZA-LOPEHANDÍA

    2011-06-01

    Full Text Available El problema de la desigualdad en Chile ha sido abordado desde diferentes puntos de vista como la cuestión de la distribución de la riqueza o el acceso a los derechos sociales. Es este trabajo se observa el mismo problema pero desde la perspectiva recientemente esbozada por los movimientos sociales: la del racismo ambiental o la desigual distribución de los deshechos del desarrollo y el consumo. De esta manera se revisan sucintamente los principales conflictos que han surgido en el último tiempo a lo largo del país entre empresas públicas y privadas y comunidades locales y originarias. Así mismo se examinan las formas de organización que estas últimas han asumido y el estado actual de articulación entre ellas. De la revisión de la situación se concluye que estamos ante el surgimiento de un actor de nuevo tipo, que surge de las contradicciones del Chile neoliberal y que se diferencia del movimiento ecologista por vincular sus reivindicaciones a la defensa del territorio y al derecho a la autodeterminación de los pueblos.

  3. Miedo y represionpolitica en Chile

    Directory of Open Access Journals (Sweden)

    Amado M. Padilla

    1987-01-01

    Full Text Available This paper describes a human rights fact-finding mission to Chile concerned with the use of psychological techniques employed in offlcia- Uy sactioned torture and repressíon, Meetings and interviews were conducted with representatives of many organízatíons working with víctima of governrnental repression including the Chílean Psychological Assocíation. Fear and repression wene found to be widespread among all socioeconomic segments of the population. Physical and psychological abuses directed at individuals are díscussed, Psychological techníques used in the control of social groups such as intimidation, control of information, and community destabilization are also described. It is concluded that violations of human rigths are a reality in Chile. Ways to support the work of Chilean psychologists must be sought sínce the damaging eonsequences of officially sanctioned repressíon are wid.espread, and resources are minimal.

  4. President of Chile at CERN

    CERN Multimedia

    2007-01-01

    The President of Chile, Michelle Bachelet, in the ATLAS cavern with, from left to right, Peter Jenni, ATLAS Spokesman, Vivian Heyl, CONICYT President, and Robert Aymar, CERN Director-General. Robert Aymar, CERN Director-General, and Vivian Heyl, CONICYT President, signing a cooperation agreement between CERN and Chile’s Comisión Nacional de Investigación Científica y Tecnológica (CONICYT).The President of Chile, Michelle Bachelet, paid a visit to CERN during her three-day tour of Switzerland. The charismatic Michelle Bachelet and her large delegation were greeted by the CERN Director-General and then taken to see the ATLAS experiment and the LHC. She also took time to meet the Chilean community working at CERN, comprising several physicists in the Theory Group and the ATLAS experiment. The meeting was followed by the signing of a cooperation agreement between CERN and Chile’s Comisión Nacional de Investigación Científi...

  5. VizieR Online Data Catalog: V960 Mon light curves (Hackstein+, 2015)

    Science.gov (United States)

    Hackstein, M.; Haas, M.; Kospal, A.; Hambsch, F.-J.; Chini, R.; Abraham, P.; Moor, A.; Pozo Nunez, F.; Ramolla, M.; Westhues, C.; Kaderhandt, L.; Fein, C.; Barr Dominguez, A.; Hodapp, K.-W.

    2015-10-01

    Photometric light curves for V960Mon (2MASS J06593158-0405277) from different telescopes at multiple wavelengths between September 2009 to June 2015. This comprises optical observations from Universitaetssternwarte Bochum (USB) in Chile as part of the Bochum Galatic Disk Survey (GDS, 2015AN....336..590H), Konkoly Observatory in Hungary, and the Remote Observatory Atacama Desert (ROAD) in Chile, as well as near-infrared data from USB. (1 data file).

  6. Deserts

    DEFF Research Database (Denmark)

    Graulund, Rune

    2016-01-01

    examines: •Key debates within the field, including postcolonial studies, gender, sexuality and visual culture •Historical and cultural contexts, tracing the evolution of travel writing across time and over cultures •Different styles, modes and themes of travel writing, from pilgrimage to tourism •Imagined......As many places around the world confront issues of globalization, migration and postcoloniality, travel writing has become a serious genre of study, reflecting some of the greatest concerns of our time. Encompassing forms as diverse as field journals, investigative reports, guidebooks, memoirs......, comic sketches and lyrical reveries; travel writing is now a crucial focus for discussion across many subjects within the humanities and social sciences. An ideal starting point for beginners, but also offering new perspectives for those familiar with the field, The Routledge Companion to Travel Writing...

  7. Vertical stress transfer after large subduction zone earthquakes: 2007 Tocopilla /North Chile case study

    Science.gov (United States)

    Eggert, S.; Sobiesiak, M.; Victor, P.

    2011-12-01

    Large interplate subduction zone earthquakes occur on fault planes within the seismogenic interface which, in the case of Northern Chile, usually start to break at the down dip end of the coupled interface, propagating towards the trench. Although the rupture is a horizontally oriented process, some vertical connectivity between the interface and the upper crust should be expected. We study two clusters of aftershock seismicity from the Mw 7.7, 2007, Tocopilla earthquake in Northern Chile Both clusters seem to align along vertical profiles in the upper crust above the main shock rupture plane. The first cluster has a rather dissipative character at the up-dip limit of the rupture plane in the off-shore area around the Peninsula of Mejillones. It developed in the early stage of the aftershock sequence. The second cluster lies above the pronounced aftershock sequence of a secondary large Mw 6.9 slab-push event on 16th of December 2007. This type of compressional event can occur after large thrust earthquakes. A comparison of the epicentral distribution of the crustal events belonging to the aftershock sequence suggests a possible relation to the Cerro Fortuna Fault in the Coastal Cordillera which is a subsidiary fault strand of the major Atacama Fault Zone. We compute the Coulomb stress change on the respective faults of both clusters analyzed to see where slip is promoted or inhibited due to the slip on the subduction interface. We then combine these results with the spatial and temporal aftershock distribution, focal mechanism solutions, b-value mappings and geological evidences to understand the process behind the ascending seismicity clusters and their relation to the main shock of the major Tocopilla event.

  8. [New Liolaemus (Iguania: Liolaemidae) with a new morphological character from the border between Argentina and Chile].

    Science.gov (United States)

    Abdala, Cristian Simón; Paz, Marcos Maximiliano; Semhan, Romina Valeria

    2013-12-01

    Liolaemus belongs to the Eulaemus subgenus, that is included in the Liolaemus montanus group or section, and is distributed in Argentina, Bolivia, Chile and Peru. The species members of this clade inhabit arid and high altitude environments, usually above 2800 m, and have a strong tendency to herbivory and a viviparous reproductive type. In a herpetological expedition to the Salta Province highlands, Argentina, in April 2012, we collected individuals of this new species for their description. The specimens were collected with loop, slaughtered by anesthesia and deposited in the herpetological collection of Fundación Miguel Lillo in Tucuman (FML). To characterize this new taxon, we analyzed 144 external morphological characters, referring primarily to lepidosis, color pattern, and body proportions, comparing with data from 66 constituent species of the L. montanus group (45 taxa from collection specimens and 21 from literature). Description of the colors in life was made in the field and based on photographs taken during the capture. The species described in this work inhabits a very narrow mountain range area in Salta Province (Argentina), and the Atacama Region (Chile), always above the 3600 m. This new taxon shows characteristics of lepidosis and color patterns clearly different from the other species members of the L. montanus group: the maximum snout-vent length is 72.9 mm; shows 74-96 scales around midbody, 89-104 dorsal scales between the occiput and hind limbs, 92-109 ventrals, precloacal pores are evident in both, males and females, and supernumerary pores in males. Also, the presence of postcloacal pores stands out as unique among all Liolaemus. This is a new character, not only for the genus, but also to all Reptilia, becoming a morphological discovery of great importance, since in reptiles only precloacal and femoral pores are known. Based on our field observations, this new Liolaemus is related to rocky environments, which are used as refuge by this

  9. Slow and Steady Drop of the Atacama Water Table from ~15 Ma Constrained by (U-Th)/He Dating of Hematite

    Science.gov (United States)

    Cooper, F. J.; Adams, B. A.; Blundy, J. D.; Farley, K. A.; McKeon, R. E.; Ruggiero, A.

    2015-12-01

    The western margin of the Central Andes in northern Chile and southern Peru has an arid climate that is thought to have persisted for at least 15 Ma [1-3]. The onset of aridity has been linked to uplift of the Andes, which blocked moisture from the Amazon, creating a rain shadow [e.g. 1]. However, the timing of this uplift and its potential effect on regional climate is poorly understood, with uplift estimates ranging from slow and steady since ≥25 Ma to recent and rapid between ˜10 and 6 Ma [4 & refs therein]. A direct consequence of both tectonic uplift and climate desiccation is the downward migration of the water table [e.g. 5, 6]. Therefore, the timing and rate of water table drop can help to discern between uplift and aridity models. Here, we directly track the temporal downward migration of the Atacama water table using (U-Th)/He dating of hematite [7]. The hematite (Fe2O3) formed by reaction of oxygenated groundwater with ferrous-bearing minerals above the redox interface [e.g. 8]. Thus, the depth of hematite precipitation as a function of time can be used to constrain the relative movement of the water table. Nine samples were collected in drill core from an active mine in northern Chile, providing precise depth profiles through the top few 100 m beneath the surface. Our results imply a slow and steady lowering of the water table from ~15 Ma to the present day at a rate of ~11 m/Ma. This change at ~15 Ma reflects onset of river incision due to either an increase in climate aridity or an increase in rock uplift rate along the western Andean margin. Whatever the cause, the steady rate of lowering of the water table implied by our data suggests that the driver has been constant over the last ~15 Ma. [1] Alpers & Brimhall (1988), GSAB 100, 1640-1656. [2] Hartley (2003), J. Geol. Soc. London 160, 7-10. [3] Rech et al. (2006), Geology 34, 761-764. [4] Barnes & Ehlers (2009), Earth-Sci. Rev. 97, 117-144. [5] Coates (1990), GSA Spec. Pap. 252, 341-356. [6

  10. Chile: los mapuches y el Bicentenario Chile: Mapuches e do Bicentenario Chile: Mapuche and the Bicentennial

    Directory of Open Access Journals (Sweden)

    José Bengoa

    2011-12-01

    Full Text Available El Bicentenario de la República de Chile se conmemoró en el mes de septiembre del año 2010. Además de marcar un importante hito histórico, coincidió con un cambio político en el Gobierno del país, el que pasó de la Concertación de Partidos por la Democracia a la Alianza de partidos formada por la derecha chilena. Se cumplieron por tanto 20 años desde que en el año 1990 cambiara el Gobierno militar presidido por el general Pinochet. Ese largo tiempo, dos décadas, coincide con un período de políticas que el Estado ha implementado hacia los Pueblos Indígenas. El Proyecto “Conmemoraciones y Memorias Subalternas” ha realizado durante el año 2010 un conjunto de investigaciones de terreno y documentales tendientes a comprender del modo más objetivo y científico lo ocurrido en el período y por tanto la situación actual de las sociedades mapuches en sus complejas relaciones con la chilena.O Bicentenario da República do Chile comemorou-se no mês de Setembro do ano 2010. Junto com transformar-se num marco histórico, coincidiu com uma mudança política no Governo do país, que passou da Concertação de Partidos pela Democracia (centro-esquerda à Aliança de partidos formada pela direita chilena. Cumpriram-se por tanto 20 anos desde que em 1990 mudasse o Governo militar presidido pelo general Pinochet. Esse longo tempo, duas décadas, coincide com um período de políticas que o Estado implementou para com os Povos Indígenas. O Projeto “Comemorações e Memórias Subalternas” realizou durante o ano 2010 um conjunto de pesquisas de campo e documentais tendentes a compreender do modo mais objetivo e científico o ocorrido no período e, por tanto, a situação atual das sociedades mapuches em suas complexas relações com a chilena.The conmeration of the 200 years of the Independence of Chile was in September 2010. This year was also the political change from the Concertación de Partidos por la Democracia to the right

  11. Primer registro de cráneos asignados a Palaeospheniscus (Aves, Spheniscidae procedentes de la Formación Bahía Inglesa (Mioceno Medio-tardío, Chile First record of skulls assigned to Palaeospheniscus (Aves, Spheniscidae from the Bahía Inglesa formation (middle-late Miocene, Chile

    Directory of Open Access Journals (Sweden)

    CAROLINA ACOSTA HOSPITALECHE

    2005-09-01

    Full Text Available Los cráneos de los Spheniscidae (como los de todas las aves, aunque escasos en el registro paleontológico, muestran importantes caracteres a nivel taxonómico. Hasta el momento se conocían solo seis cráneos en todo el mundo: Paraptenodytes antarctica y una nueva especie de Spheniscidae procedentes de las formaciones Gaiman (Mioceno temprano y Puerto Madryn (Mioceno tardío de Argentina, respectivamente; Spheniscus megaramphus y 3S. urbinai de la formación Pisco (Mioceno tardío de Perú, Marplesornis novaezealandiae del Plioceno de Nueva Zelanda y un resto de Sphenicidae cf Spheniscus procedente de la formación Bahía Inglesa (Mioceno medio-tardío. De esta última unidad provienen cinco restos craneanos recientemente descubiertos en la localidad de Caldera (Región de Atacama, Chile, los cuales fueron descritos y asignados preliminarmente a Palaeospheniscus. Estos materiales constituyen el primer registro de cráneos para la especie y significan un importante aporte al conocimiento de la avifauna fósil de Chile y en particular de la formación Bahía InglesaAlthough the skulls of the Spheniscidae are unusual in the paleontologic record, they show important features useful in the systematics of the group, as well as in the rest of the birds. Until now, fossil occurrences were restricted to six skulls: Paraptenodytes antarctica and one new species from the Gaiman formation (Early Miocene and Puerto Madryn formation (late Miocene of Argentina, respectively; Spheniscus megaramphus and S. urbinai from the Pisco Formation (Late Miocene, Perú; Marplesornis novaezealandiae from New Zealand (Pliocene; and Spheniscidae cf. Spheniscus from the Bahía Inglesa Formation (Middle-Late Miocene, Chile. Five new materials have been exhumed from this last unit. These skulls, which come from the Caldera locality (Region of Atacama, Chile, have been preliminarily assigned to Palaeospheniscus (Aves, Spheniscidae, constituting the first skulls described for

  12. Rural childhoods in Egypt's desert lands

    OpenAIRE

    Adriansen, Hanne Kristine

    2007-01-01

    Based on fieldwork in Egypt’s desert lands, this paper discusses rural childhoods in an area experiencing rapid social and cultural change. Since 1987, the Egyptian Government has made new villages in the desert as a means to increase agricultural production and solving problems of unemployment. Many settlers move to the Mubarak villages in order to give their children a good start in life. The desert villages are associated with a type of ‘rural idyll’. The process of settling in the de...

  13. Rural childhoods in Egypt's desert lands

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    Based on fieldwork in Egypt’s desert lands, this paper discusses rural childhoods in an area experiencing rapid social and cultural change. Since 1987, the Egyptian Government has made new villages in the desert as a means to increase agricultural production and solving problems of unemployment......’s new roles impact upon the children’s lives. The social contexts shaping the desert childhoods are in some ways more similar to contexts in ‘developed’ countries than in other parts of rural Egypt. The paper ends up by contrasting ideas of rural childhoods in Egypt with those found in ‘developed...

  14. Microphytic crusts: 'topsoil' of the desert

    Science.gov (United States)

    Belnap, Jayne

    1990-01-01

    Deserts throughout the world are the home of microphytic, or cryptogamic, crusts. These crusts are dominated by cyanobacteria, previously called blue-green algae, and also include lichens, mosses, green algae, microfungi and bacteria. They are critical components of desert ecosystems, significantly modifying the surfaces on which they occur. In the cold deserts of the Colorado Plateau (including parts of Utah, Arizona, Colorado, and New Mexico), these crusts are extraordinarily well-developed, and may represent 70-80% of the living ground cover.

  15. Village microgrids: The Chile project

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, E.I.

    1997-12-01

    This paper describes a village application in Chile. The objective was to demonstrate the technical, economic and institutional viability of renewable energy for rural electrification, as well as to allow local partners to gain experience with hybrid/renewable technology, resource assessment, system siting and operation. A micro-grid system is viewed as a small village system, up to 1200 kWh/day load with a 50 kW peak load. It can consist of components of wind, photovoltaic, batteries, and conventional generators. It is usually associated with a single generator source, and uses batteries to cover light day time loads. This paper looks at the experiences learned from this project with regard to all of the facets of planning and installing this project.

  16. Desert Dust and Monsoon Rain

    Science.gov (United States)

    Lau, William K. M.; Kim, Kyu-Myong

    2014-01-01

    For centuries, inhabitants of the Indian subcontinent have know that heavy dust events brought on by strong winds occur frequently in the pre-monsoon season, before the onset of heavy rain. Yet scientists have never seriously considered the possibility that natural dust can affect monsoon rainfall. Up to now, most studies of the impacts of aerosols on Indian monsoon rainfall have focused on anthropogenic aerosols in the context of climate change. However, a few recent studies have show that aerosols from antropogenic and natural sources over the Indian subcontinent may affect the transition from break to active monsoon phases on short timescales of days to weeks. Writing in Nature Geoscience, Vinoj and colleagues describe how they have shown that desert dust aerosols over the Arabian Sea and West Asia can strenghten the summer monsoon over the Indial subcontinent in a matter of days.

  17. 1960 Puerto Montt, Valdivia, Chile Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On May 22, 1960, a Mw 9.5 earthquake, the largest earthquake ever instrumentally recorded, occurred in southern Chile. The series of earthquakes that followed...

  18. Report on the ESO Chile Science Days

    Science.gov (United States)

    West, Michael

    2008-03-01

    Science Days in Santiago are an annual gathering of ESO's geographically dispersed team in Chile to learn more about each other's research, to celebrate scientific achievements of the past year and to encourage new collaborations.

  19. Surface Observations from Punta Arenas, Chile

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface Observations from Punta Arenas, in extreme southern Chile. WMO station ID 85934. Period of record 1896-1954. The original forms were scanned at the Museo...

  20. Biomonitoring air pollution in Chile

    International Nuclear Information System (INIS)

    Full text: Chile, in general, and Santiago, its capital city, in particular, has serious air pollution problems mainly in winter time when the pollutants could reach dangerous levels which might be detrimental to older people and children. A project was undertaken within the framework of a Co-ordinated Research Programme (CRP) supported by the International Atomic Energy Agency (IAEA) to carry out a long term study on atmospheric air pollution in Chile using biomonitors. The present paper describes the activities carried out within this CRP. The lichens, collected in clean areas (native forests), were transplanted to selected sites in Santiago and exposed during three and six months. At a second stage, samples of Tillandsia recurvata were collected in the Metropolitan Area. All samples were carefully cleaned, using only clean plastic materials, milled at liquid nitrogen temperature, freeze dried, re-homogenized and stored at low temperature until analysis. The samples were mainly analysed by INAA, RNAA SS-AAS and ASV. As part of the routine QA/QC programme, analytical laboratories involved in the project participated in intercomparison runs organized by the IAEA for the determination of trace and minor elements in two lichens samples. From the data and its subsequent mapping over the area under study, it was possible to identify places exposed to higher amounts of some elements. Of interest are also the correlations between several elements, perhaps indicating a given source of pollutants. The results indicate the usefulness of biomonitoring air pollution using lichens and Tillandsias, which, jointly with multielemental analytical techniques, such as NAA, open the possibility to study extensive areas without the infrastructure needed for conventional APM sample collection and at reduced costs. (author)

  1. The Mojave Desert: A Martian Analog Site for Future Astrobiology Themed Missions

    Science.gov (United States)

    Salas, E.; Abbey, W.; Bhartia, R.; Beegle, L. W.

    2011-01-01

    Astrobiological interest in Mars is highlighted by evidence that Mars was once warm enough to have liquid water present on its surface long enough to create geologic formations that could only exist in the presense of extended fluvial periods. These periods existed at the same time life on Earth arose. If life began on Mars as well during this period, it is reasonable to assume it may have adapted to the subsurface as environments at the surface changed into the inhospitable state we find today. If the next series of Mars missions (Mars Science Laboratory, the ExoMars Trace Gas Orbiter proposed for launch in 2016, and potential near surface sample return) fail to discover either extinct or extant life on Mars, a subsurface mission would be necessary to attempt to "close the book" on the existence of martian life. Mars is much colder and drier than Earth, with a very low pressure CO2 environment and no obvious habitats. Terrestrial regions with limited precipitation, and hence reduced active biota, are some of the best martian low to mid latitude analogs to be found on Earth, be they the Antarctic dry valleys, the Atacama or Mojave Deserts. The Mojave Desert/Death Valley region is considered a Mars analog site by the Terrestrial Analogs Panel of the NSF-sponsored decadal survey; a field guide was even developed and a workshop was held on its applicability as a Mars analog. This region has received a great deal of attention due to its accessibility and the variety of landforms and processes observed relevant to martian studies.

  2. Desert dust satellite retrieval intercomparison

    Directory of Open Access Journals (Sweden)

    E. Carboni

    2012-01-01

    Full Text Available This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR, polarisation measurements (POLDER, single-view approaches using solar wavelengths (OMI, MODIS, and the thermal infrared spectral region (SEVIRI, AIRS. Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as assumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  3. Hemophilia in Chile, 1996-2006

    OpenAIRE

    Mario Donoso Scroppo

    2013-01-01

    This article describes the process that Chile underwent from 1996 to 2006, which is the dawn of a period of planned and systematic organization that begins to solve the severe health problems that afflict patients with hemophilia. The article reports a general overview of the situation of hemophilia in Chile in that period – up to 2006 - , including the lack of reliable data, treatment options, training of specialists on the topic and healthcare system responses. The article then goes on to d...

  4. Enterprise Surveys : Chile Country Profile 2010

    OpenAIRE

    World Bank; International Finance Corporation

    2011-01-01

    The Country Profile for Chile is based on data from the Enterprise Surveys conducted by the World Bank. The benchmarks include the averages for the group of countries in Latin America & Caribbean and the Chile income group. The enterprise surveys focus on the many factors that shape the decisions of firms to invest. These factors can be accommodating or constraining and play an important r...

  5. Chile ushers in new hydro era

    International Nuclear Information System (INIS)

    The planned construction of two hydroelectric power plants at Peuchen and Mampil, will help to meet Chile's growing electricity demand. Securing finance for the project has been straight forward thanks to the optimal hydrological conditions, rivers with a very strong flow providing a large head of water over short distance. Hydropower plays a central role in Chile's generating capacity providing 70% of total energy consumption. Thus, the future of these projects will be highly successful, it is argued. (UK)

  6. Desigualdad geográfica en Chile

    OpenAIRE

    Agostini, Claudio A.; Brown, Philip H.

    2007-01-01

    Despite success in reducing poverty over the last twenty years, inequality in Chile has remained virtually unchanged, making Chile one of the least equal countries in the world. High levels of inequality have been shown to hamper further reductions in poverty as well as economic growth and local inequality has been shown to affect such outcomes as violence and health. The study of inequality at the local level is thus crucial for understanding the economic well-being of a country. Local measu...

  7. Trade and Integration Sector Note: Chile

    OpenAIRE

    Mauricio Mesquita Moreira

    2006-01-01

    This Trade and Integration Sector Note addresses a few different factors for trade in Chile: export diversification, trade and regional disparities, preferential agreements, trade and transport costs. The final section looks beyond the conventional tariff and non tariff-barriers to trade, and focuses on the role of transport costs. Given Chile's low tariff and non-tariff barriers and its network of trade agreements, the reduction of non-conventional trade costs are bound to offer the best ret...

  8. The New Critical Reading of Desert Places

    Institute of Scientific and Technical Information of China (English)

    BING Zhao-yu

    2013-01-01

    From the perspective of new criticism, this article attempts at a profound study of Robert Frost’s Desert Places so as to better understand the value, reveal the meaning and enjoy the charm of this works.

  9. Proposed Desert Pupfish Preserve : Supplemental LARC Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains supplements to a previous report on the desert pupfish preserve proposal. The attachments are titled: “Vertebrate Animals and Vascular...

  10. Vegetation - Central Mojave Desert [ds166

    Data.gov (United States)

    California Department of Resources — The Department of Defense and the other desert managers are developing and organizing scientific information needed to better manage the natural resources of the...

  11. Desert National Wildlife Range Wilderness study summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a summary of a wilderness study done of the Desert National Wildlife Range pursuant to the Wilderness Act of 1964. It provides information as to...

  12. MARS DESERT RESEARCH STATION: CREW 138

    OpenAIRE

    Roman-Gonzalez, Avid; Saab, Bechara; Berger, Jay; hoyt, johanna; Urquhart, Jimmy; guined, jamie

    2015-01-01

    Crew 138 was comprised of a team of highly-skilled professionals with varied backgrounds who were selected by the Mars Society to undertake a two-week interdisciplinary expedition at the Mars Desert Research Station near Hanksville, Utah. The Crew's activities ranged in scope from preparing operational handbooks and checklists for the Mars Desert Research Station, performing hardware and logistical evaluations for future research at MDRS, an analysis of Google Earth as a tool for geological f...

  13. Physiological Conjunction of Allelochemicals and Desert Plants

    OpenAIRE

    Yosef Friedjung, Avital; Choudhary, Sikander Pal; Dudai, Nativ; Rachmilevitch, Shimon

    2013-01-01

    Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from...

  14. Self-propelled Desert Workover Rig

    Institute of Scientific and Technical Information of China (English)

    Liu Xin; Xie Pengming; Shi Bing

    1996-01-01

    @@ The Taklimakan Desert in the Taxim Basin of western China is the second largest desert in the world. Its relative elevation is 100- 150 m, somewhere 200-300 m. The annual amount of precipitation is 25 mm to 40 mm in most area and less than 15 mm in the east area. the annual amount of evaporation is usually between 2 100 mm and 3 400 mm.

  15. Cost of m{sup 2} installed of hot water to pave in cities of the desert of Atacama; Costo del m{sup 2} instalado de agua caliente solar en ciudades del desierto de Atacama

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, W. W.; Galleguillos, V. R.; Echevarria, A. J.

    2008-07-01

    In this work were registered the domiciliary solar hot water of flat plate collectors for innovating projects that rationalize their use in Antofagasta, 300000 habitants; 23,5 degree S: 70.1 degree W. Average solar radiation in the city is about of 20 MJ/m{sup 2}fay. The medium temperature of water by day on the city is 17 degree centigrade. Annual average of the relative humidity is approximately 70%m the precipitations in the city are extremely low about 1 mm and the sea breeze is around 2.5 m/s, which comes from of the ocean pacific in SW direction. Our study informs that to heat 100 liters of water up to 40 degree centigrade, it is necessary 1 m{sup 2} of solar collector to US$ 700, the m{sup 2} installed. The city has 61 of these facilities in hospitals, school, high school and housings. Our study informs of a total of 700 m{sup 2} of solar collector and 33400 available of hot water liters. (Author)

  16. Processes of lithium chlorides purification from Salar de Atacama concentrated brines

    International Nuclear Information System (INIS)

    The results of research carried out to obtain lithium chloride, as a suitable electrolyte for the production of high purity lithium metal are presented. Concentrated lithium chloride brines from Salar de Atacama have been used as starting materials. The studied process requires the reduction of the boron content in the brines to levels below 5 ppm, followed by a crystallization process to obtain a crystallized lithium chloride. The elimination of the magnesium chloride co-crystallized with the lithium chloride, is achieved by a complementary washing step and the lixiviation of the impure LiCl crystals with ethanol. (author)

  17. Estrategias readaptativas en Atacama: la arriería mulera colonial1

    OpenAIRE

    T., Cecilia Sanhueza

    2014-01-01

    Introducción La arriería indígena comenzó a desarrollarse en Atacama durante la segunda mitad del siglo xvi y parece haber adquirido, tempranamente, un papel de importancia para la población local entre las alternativas de participación en los mercados coloniales y como medio de acceso a metálico o circulante. El tráfico de productos regionales –principalmente marinos– hacia los centros urbanos y mineros altiplánicos, ha sido descrito por los cronistas como una de las principales actividades ...

  18. The Atacama Cosmology Telescope: Evidence for Dark Energy from the CMB Alone

    CERN Document Server

    Sherwin, Blake D; Das, Sudeep; Appel, John W; Bond, J Richard; Carvalho, C Sofia; Devlin, Mark J; Dunner, Rolando; Essinger-Hileman, Thomas; Fowler, Joseph W; Hajian, Amir; Halpern, Mark; Hasselfield, Matthew; Hincks, Adam D; Hlozek, Renee; Hughes, John P; Irwin, Kent D; Klein, Jeff; Kosowsky, Arthur; Marriage, Tobias A; Marsden, Danica; Moodley, Kavilan; Menanteau, Felipe; Niemack, Michael D; Nolta, Michael R; Page, Lyman A; Parker, Lucas; Reese, Erik D; Schmitt, Benjamin L; Sehgal, Neelima; Sievers, Jon; Spergel, David N; Staggs, Suzanne T; Swetz, Daniel S; Switzer, Eric R; Thornton, Robert; Visnjic, Katerina; Wollack, Ed

    2011-01-01

    For the first time, measurements of the cosmic microwave background radiation (CMB) alone favor cosmologies with $w=-1$ dark energy over models without dark energy at a 3.2-sigma level. We demonstrate this by combining the CMB lensing deflection power spectrum from the Atacama Cosmology Telescope with temperature and polarization power spectra from the Wilkinson Microwave Anisotropy Probe. The lensing data break the geometric degeneracy of different cosmological models with similar CMB temperature power spectra. Our CMB-only measurement of the dark energy density $\\Omega_\\Lambda$ confirms other measurements from supernovae, galaxy clusters and baryon acoustic oscillations, and demonstrates the power of CMB lensing as a new cosmological tool.

  19. The Atacama Cosmology Telescope: Calibration with the Wilkinson Microwave Anisotropy Probe Using Cross-Correlations

    Science.gov (United States)

    Hajian, Amir; Acquaviva, Viviana; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John William; Barrientos, L. Felipe; Battistelli, Elia S.; Bond, John R.; Brown, Ben; Burger, Bryce; Chervenak, Jay; Das, Sudeep; Devlin, Mark J.; Dicker, Simon R.; Bertrand Doriese, W.; Dunkley, Joanna; Dunner, Rolando; Essinger-Hileman, Thomas; Fisher, Ryan P.; Fowler, Joseph W.; Halpern, Mark; Hasselfield, Matthew; Moseley, Harvey; Wollack, Ed

    2011-01-01

    We present a new calibration method based on cross-correlations with the Wilkinson Microwave Anisotropy Probe (WMAP) and apply it to data from the Atacama Cosmology Telescope (ACT). ACT's observing strategy and mapmaking procedure allows an unbiased reconstruction of the modes in the maps over a wide range of multipoles. By directly matching the ACT maps to WMAP observations in the multipole range of 400 cosmological parameters estimated from the ACT power spectra. We also present a combined map based on ACT and WMAP data that has a high signal-to-noise ratio over a wide range of multipoles.

  20. The Genus Austroleptis from South Chile and Patagonia (Diptera, Rhagionidae)

    OpenAIRE

    NAGATOMI, Akira; NAGATOMI, Hisako; ナガトミ, アキラ; ナガトミ, ヒサコ; 永冨, 昭; 永冨, 尚子

    1988-01-01

    The genus Austroleptis from South Chile and Patagonia is revised and three new species are added. So, there are eight known species, five of which are from South Chile and Patagonia and three from Australia and Tasmania.

  1. Regulated electricity retailing in Chile

    Energy Technology Data Exchange (ETDEWEB)

    Galetovic, Alexander, E-mail: alexander@galetovic.cl [Facultad de Ciencias Economicas y Empresariales, Universidad de los Andes, Santiago, Chile. Av. San Carlos de Apoquindo 2200, Las Condes, Santiago (Chile); Munoz, Cristian M., E-mail: cmunozm@aes.com [AES Gener and Departamento de Ingenieria Electrica, Universidad Catolica de Chile (Chile)

    2011-10-15

    While some countries have unbundled distribution and retailing, skeptics argue that the physical attributes of electricity make retailers redundant. Instead, it is claimed that passive pass through of wholesale prices plus regulated charges for transmission and distribution suffice for customers to benefit from competitive generation markets. We review the Chilean experience with regulated retailing and pass through of wholesale prices. We argue that when energy wholesale prices are volatile and prices are stabilized, distortions emerge. Regulated retailers gain little by mitigating or correcting them. On the contrary, sometimes price distortions increase their profits. We estimate the cost of three distortions that neither regulated retailers nor the regulator have shown any interest in correcting. - Highlights: > We review Chile's experience with regulated electricity retailing. > Distortions emerge when energy wholesale prices are volatile and prices stabilized. > Regulated retailers gain little by mitigating or correcting distortions. > Sometimes price distortions increase retailers' profits. > We estimate the cost of three distortions, which retailers have not corrected.

  2. Regulated electricity retailing in Chile

    International Nuclear Information System (INIS)

    While some countries have unbundled distribution and retailing, skeptics argue that the physical attributes of electricity make retailers redundant. Instead, it is claimed that passive pass through of wholesale prices plus regulated charges for transmission and distribution suffice for customers to benefit from competitive generation markets. We review the Chilean experience with regulated retailing and pass through of wholesale prices. We argue that when energy wholesale prices are volatile and prices are stabilized, distortions emerge. Regulated retailers gain little by mitigating or correcting them. On the contrary, sometimes price distortions increase their profits. We estimate the cost of three distortions that neither regulated retailers nor the regulator have shown any interest in correcting. - Highlights: → We review Chile's experience with regulated electricity retailing. → Distortions emerge when energy wholesale prices are volatile and prices stabilized. → Regulated retailers gain little by mitigating or correcting distortions. → Sometimes price distortions increase retailers' profits. → We estimate the cost of three distortions, which retailers have not corrected.

  3. EL LIDERAZGO ÉTNICO EN ATACAMA, ALTOS DE ARICA, TACNA Y TARATA (SIGLO XVIII

    Directory of Open Access Journals (Sweden)

    Jorge Hidalgo Lehuedé

    2004-09-01

    Full Text Available En este artículo realizamos un análisis comparado de las dinámicas y transformaciones que experimentó el liderazgo étnico de los cacicazgos de Atacama, Codpa, Altos de Arica, Tacna y Tarata, durante el siglo XVIII. Sostenemos, además, que las dinámicas del liderazgo étnico se ajustaron, más que a proyectos comunitarios, a estrategias familiares. Estas últimas debieron enfrentarse a condiciones sociales de posibilidad en las que se entremezclaron las limitaciones, las demandas y las oportunidades que les ofrecía el campo social colonialIn this article we will realice a comparative analysis of the dynamic and transformations that experienced the ethnic leadership of the Atacama, Codpa, Tacna and Tarata chiefdom, during 18th century. We support, beside, that the ethnic leadership dynamics adjusted more to a family strategy than a communitary project. This family strategy should face a social conditions of possibilities, just a mixture of limitation, demands and opportunities that the colonial society offer them

  4. The Atacama Cosmology Telescope: The LABOCA/ACT Survey of Clusters at All Redshifts

    CERN Document Server

    Lindner, Robert R; Baker, Andrew J; Bond, J Richard; Crichton, Devin; Devlin, Mark J; Essinger-Hileman, Thomas; Hilton, Matt; Hincks, Adam D; Huffenberger, Kevin M; Hughes, John P; Infante, Leopoldo; Lima, Marcos; Marriage, Tobias A; Menanteau, Felipe; Niemack, Michael D; Page, Lyman A; Schmitt, Benjamin L; Sehgal, Neelima; Sievers, J L; Sifón, Cristóbal; Staggs, Suzanne T; Swetz, Daniel; Weiß, Axel; Wollack, Edward J

    2014-01-01

    We present a multi-wavelength analysis of eleven Sunyaev Zel'dovich effect (SZE)-selected galaxy clusters (ten with new data) from the Atacama Cosmology Telescope (ACT) southern survey. We have obtained new imaging from the Large APEX Bolometer Camera (345GHz; LABOCA) on the Atacama Pathfinder EXperiment (APEX) telescope, the Australia Telescope Compact Array (2.1GHz; ATCA), and the Spectral and Photometric Imaging Receiver (250, 350, and $500\\,\\rm\\mu m$; SPIRE) on the Herschel Space Observatory. Spatially-resolved 345GHz SZE increments with integrated S/N > 5 are found in six clusters. We compute 2.1GHz number counts as a function of cluster-centric radius and find significant enhancements in the counts of bright sources at projected radii $\\theta < \\theta_{2500}$. By extrapolating in frequency, we predict that the combined signals from 2.1GHz-selected radio sources and 345GHz-selected SMGs contaminate the 148GHz SZE decrement signal by ~5% and the 345GHz SZE increment by ~18%. After removing radio source...

  5. Radioactive wastes management development in Chile

    International Nuclear Information System (INIS)

    A Facility for immobilizing and conditioning of radioactive wastes generated in Chile, has recently started in operation. It is a Radioactive Wastes Treatment Plant, RWTP, whose owner is Comision Chilena de Energia Nuclear, CCHEN. A Storgement Building of Conditioned Wastes accomplishes the facility for medium and low level activity wastes. The Project has been carried with participation of chilean professionals at CCHEN and Technical Assistance of International Atomic Energy Agency, IAEA. Processes developed are volume reduction by compaction; immobilization by cementation and conditioning. Equipment has been selected to process radioactive wastes into a 200 liters drum, in which wastes are definitively conditioned, avoiding exposition and contamination risks. The Plant has capacity to treat low and medium activity radioactive wastes produced in Chile due to Reactor Experimental No. 1 operation, and annex Laboratories in Nuclear Research Centers, as also those produced by users of nuclear techniques in Industries, Hospitals, Research Centers and Universities, in the whole country. With the infrastructure developed in Chile, a centralization of Radioactive Wastes Management activities is achieved. A data base system helps to control and register radioactive wastes arising in Chile. Generation of radioactive wastes in Chile, has found solution for the present production and that of near future

  6. How government can support protection of “dark skies” as a public policy: the experience of Chile

    Science.gov (United States)

    Rodriguez, Gabriel

    2015-08-01

    For more than fifty years Chile has been the host of world-leading optical and radio astronomical observatories because of the exceptional atmospheric conditions and the existence of isolated areas in the northern desert regions. As of today, Chile, through agreements with foreign governments and international research institutions around the world concentrates almost 30% of the total radio and optical observation capabilities of the planet, scattered in different sites. With the new projects already planned or in construction, the country will be the host of almost 70% of the total world-wide observational facilities by 2021-2022Since the beginning of the astronomical research activities in Chile, the government has played an increasing role in attracting and facilitating the installation of these projects. The presentation shows how the relationship between the government and international consortia has evolved with special reference to designing policies to protect “dark skies” and to manage the relationship between the observations sites, the local productive activities to be developed in the same areas, mainly mining and energy, and the relationship with local communities and aboriginal populations and traditions. Special reference will be made to recent initiatives connected with World Heritage program of UNESCO, new laws and regulations and public awareness and education.

  7. Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile

    Directory of Open Access Journals (Sweden)

    Didier BAZILE

    2014-12-01

    Full Text Available Chile, isolated by a hyper-arid desert in the north, the Andes Range to the east and the Pacific and Antarctic waters (west and south, has a highly endemic flora. This hotspot of biodiversity is in danger not only due to increasing desertification, but also because human activities can diminish agrobiodiversity. Quinoa (Chenopodium quinoa Willd. is an Andean species producing highly nutritious grains, which almost disappeared from Chile during the Spanish colonization. Today less than 300 small-scale and highly isolated farmers still grow it as a rain-fed crop. This review describes the biogeographical-social context of quinoa in Chile, and its high genetic diversity as a product of a long domestication process, resulting in numerous local landraces whose conservation and use for breeding improved varieties is of paramount importance. We suggest the term “lighthouse crop” to emphasize its contribution to small scale ecological and bio diverse agriculture, particularly in stressful environments, to promote a healthier nutrition and more equitable markets in the world. Furthermore this crop and its exceptional nutritional properties were invoked by the United Nations Food and Agriculture Organization (FAO to promote its use worldwide, and to declare 2013 the International Year of Quinoa.

  8. 7 CFR 319.56-38 - Citrus from Chile.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata Blanco), and tangerines (Citrus reticulata Blanco) may be imported into the United States from Chile,...

  9. Pingüinos fósiles (Pygoscelis calderensis sp. nov. en la Formación Bahía Inglesa (Mioceno Medio-Plioceno, Chile Fossil penguins (Pygoscelis calderensis sp. nov. in the Bahía Inglesa Formation (Middle Miocene-Pliocene, Chile

    Directory of Open Access Journals (Sweden)

    Carolina Acosta Hospitaleche

    2006-07-01

    Full Text Available Se describen tres nuevos cráneos de pingüinos (Spheniscidae, asignados a Pygoscelis calderensis sp. nov., procedentes de la Formación Bahía Inglesa del Mioceno Medio-Plioceno, ubicada al sur de la localidad de Caldera, en la costa de la III Región de Atacama, Chile (27°00'S, 70°45'W a 28°00', 71°00'W. Este hallazgo permite ampliar la distribución cronológica y geográfica del género, previamente conocido desde el Plioceno Tardío de Nueva Zelanda, y constituye la mención más septentrional del mismo. Este registro, sumado a otras evidencias faunísticas, indica la existencia de períodos o corrientes oceánicas frías durante el NeógenoThree new penguin skulls (Spheniscidae, assigned to the new species Pygoscelis calderensis sp. nov. from the Bahía Inglesa Formation of Middle Miocene-Pliocene age located south of Caldera on the coast of the III Región de Atacama, Chile (27°00'S, 70°45'W to 28°00', 71°00'W, are described. This finding broadens the geographic and chronologic distribution of the genus, constituting its most northern record. Before the present work, the genus was known from the Late Pliocene of New Zealand. This record, together with other faunistic evidences, suggests the existence of periods or cold oceanic currents during the Neogene

  10. [The Great European Georg Friedrich Nicolai: physician and pacifist. Berlin, Germany, 1874 - Santiago, Chile, 1964].

    Science.gov (United States)

    Cabello C, Felipe

    2013-04-01

    Georg Friedrich Nicolai (1874-1964) was a German physician and physiologist whose pacifism during the First World War led him in 1914 to cosign with W. J. Foerster, A. Einstein and O. Bueck a "Manifesto to the Europeans" against the entry of Germany into the war and the invasion of Belgium. As a result of this appeal and his strong pacifism, Nicolai lost his positions as cardiologist to the German royal family, professor at the University of Berlin and chief of laboratory at the Charite hospital also in Berlin, and was sent as a garrison physician in Graundenz, in today's Poland. There he began to write his book, The Biology of War. It managed to avoid censorship and was published in Leipzig in 1916. He was court-martialed in Danzig in 1916 but escaped to Denmark. Nicolai was reinstated to his faculty positions by the Weimar Republic after the war but was subsequently forced to emigrate from Germany to South America by the pressure of right wing student groups who accused him of being a deserter and a traitor. From 1922 to 1932 Nicolai lived in Argentina, and from 1932 until his death in 1964, in Chile. In this later country Nicolai was professor in the University of Chile and interacted with members of the Chilean intelligentsia, including the poets Vicente Huidobro, Gonzalo Rojas and Pablo Neruda. Through his friendship with Chilean psychiatrist Agustin Tellez, Nicolai influenced the development of phenomenological psychiatric school in Chile. The Chilean novelist Fernando Alegria compared him favorably with Robert J. Oppenheimer and Linus Pauling. PMID:23900377

  11. Desert Amplification in a Warming Climate.

    Science.gov (United States)

    Zhou, Liming

    2016-01-01

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950-2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor. PMID:27538725

  12. Biodiversity of nematode assemblages from deep-sea sediments of the Atacama Slope and Trench (South Pacific Ocean)

    Science.gov (United States)

    Gambi, C.; Vanreusel, A.; Danovaro, R.

    2003-01-01

    Nematode assemblages were investigated (in terms of size spectra, sex ratio, Shannon diversity, trophic structure and diversity, rarefaction statistics, maturity index, taxonomic diversity and taxonomic distinctness) at bathyal and hadal depths (from 1050 to 7800 m) in the deepest trench of the South Pacific Ocean: the Trench of Atacama. This area, characterised by very high concentrations of nutritionally-rich organic matter also at 7800-m depth, displayed characteristics typical of eutrophic systems and revealed high nematode densities (>6000 ind. 10 cm -2). Nematode assemblages from the Atacama Trench displayed a different composition than at bathyal depths. At bathyal depths 95 genera and 119 species were found (Comesomatidae, Cyatholaimidae, Microlaimidae, Desmodoridae and Xyalidae being dominant), whereas in the Atacama Trench only 29 genera and 37 species were encountered (dominated by Monhysteridae, Chromadoridae, Microlaimidae, Oxystominidae and Xyalidae). The genus Monhystera (24.4%) strongly dominated at hadal depths and Neochromadora, and Trileptium were observed only in the Atacama Trench, but not at bathyal depths. A reduction of the mean nematode size (by ca. 67%) was observed between bathyal and hadal depths. Since food availability was not a limiting factor in the Atacama Trench sediments, other causes are likely to be responsible for the reduction of nematode species richness and body size. The presence of a restricted number of families and genera in the Atacama Trench might indicate that hadal sediments limited nematode colonisation. Most of the genera reaching very high densities in Trench sediments (e.g., Monhystera) are opportunistic and were responsible for the significant decrease of the maturity index. The dominance of opportunists, which are known to be characterised by small sizes, might have contributed to the reduced nematode size at hadal depths. Shannon diversity and species richness decreased in hadal water depth and this pattern

  13. Income Inequality in Chile: 1990-2006

    OpenAIRE

    Alain Hourton

    2012-01-01

    The entrance of Chile to the Organization for the Economic Cooperation and Development, as the first South American country and second after Mexico in Latin America, sets a landmark in the development path that since the beginning of the 1990s decade has seemed to lead this country to a privileged position in the region. Given the reforms taken by the military regime in the 1980s, Chile is one of the most market-oriented countries in Latin America, with Free Trade Agreements and Economical Pa...

  14. Plant ecology of the Namib desert

    Directory of Open Access Journals (Sweden)

    P. Van Damme

    1991-01-01

    Full Text Available The Namib desert is reportedly the oldest desert in the world. It consists of a number of very distinct ecosystems, six of which are dealt with in this text. Among them are the sand dune, the dry river bed and the domed inselbergs vegetation. The importance of fog water absorption for the Namib flora is discussed. Two important and noteworthy endemic plant species, i.e. Welwitschia mirabilis and Acanthosicyos horrida are treated extensively, because of their great interest for plant physiology and ethnobotany, resp. Special attention is given to the importance of the CAM photosynthetic system for Namib desert plant survival. Where possible the ethnobotanic importance of the species is discussed.

  15. Ecological stability of Tarim Desert Highway shelterbelt

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhibin; XU Xinwen; LEI Jiaqiang; LI Shengyu

    2006-01-01

    The Tarim Desert Highway shelterbelt,located in hinterland of Taklimakan Desert, is irrigated by underground saline water, with three to thirty gram per litter mineral degrees. The sustainability and stability are affected by multifarious stress.The structural and functional characteristics of shelterbelt are studied to probe into correlation between environment and shelterbelt. On basis, decision analysis is applied to study ecological stability of the Tarim Desert Highway shelterbelt, to screen out limited factors, to establish general index system, and to evaluate the stability of the shelterbelt nowadays.Finally, the concept of ecological stability is utilized to manage the artificial ecosystem. The results show that the artificial ecosystem is relatively flimsy, whose stability can be increased by adjusting stand structure and improving the nutrient cycle.

  16. Ungaretti and the Invention of the Desert

    OpenAIRE

    Daniel del Percio

    2015-01-01

    The desert is the land of the Profets and its void delimits a space of infinity possibilites. The presence of this space in the italian poetry is considerable. For Giuseppe Ungaretti, a man who was born in the city of Alexandria, in Egypt, the infance was a space delimited by two deserts: the sand and the sea. Both conform in the poet a vision of time and space that the young Ungaretti will discover in the Bergson’s and Nietzsche’s philosophy and as poetry in the most pure italian tradition: ...

  17. Jojoba could stop the desert creep

    Energy Technology Data Exchange (ETDEWEB)

    1982-03-25

    The Sahara desert is estimated to be expanding at a rate of 5km a year. The Sudanese government is experimenting with jojoba in six different regions as the bush has the potential to stop this ''desert creep''. The plant, a native to Mexico, is long known for its resistance to drought and for the versatile liquid wax that can be extracted from its seeds. It is estimated that one hectare of mature plants could produce 3000 kg of oil, currently selling at $50 per litre, and so earn valuable foreign currency.

  18. Calibration of vector navigation in desert ants.

    OpenAIRE

    Collett, M; Collett, T. S.; Wehner, R

    1999-01-01

    Desert ants (Cataglyphis sp.) monitor their position relative to the nest using a form of dead reckoning [1] [2] [3] known as path integration (PI) [4]. They do this with a sun compass and an odometer to update an accumulator that records their current position [1]. Ants can use PI to return to the nest [2] [3]. Here, we report that desert ants, like honeybees [5] and hamsters [6], can also use PI to approach a previously visited food source. To navigate to a goal using only PI information, a...

  19. Chen Yadan Braves the Lop Desert

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    BOARDING the airplane to Urumuqi on October 29, 1997, Chen Yadan felt incredibly excited. She was finally about to embark on the Lop Desert journey she had planned for ten years. The artist was adventuring into the desert, not only to sketch its special charm with her pencils, but to follow the footsteps that her father left behind 60 years ago. She was yearning to experience the formidable struggle taken by the old generation of scientists. Chen Yadan’s father, Chen Zongqi, had been the deputy director of the

  20. Hallazgo de Ehrlichia canis en Chile, informe preliminar Ehrlichia canis in Chile; preliminary report

    Directory of Open Access Journals (Sweden)

    J. LÓPEZ

    1999-01-01

    Full Text Available Se describe el primer caso de Ehrlichiosis canina detectado en Chile, causado por la rickettsia Ehrlichia canis y transmitida por el vector Rhipicephalus sanguineus. El diagnóstico clínico fue confirmado en Alemania por Inmunofluorescencia Indirecta (IFATThe first case of canine ehrlichiosis detected in Chile is described. It is caused by the rickettsia Ehrlichia canis and carried by the vektor Rhipicephalus sanguineus. The clinical diagnosis was confirmed in Germany using the Immunofluorescent Antibody Test (IFA