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Sample records for site nuussuaq peninsula

  1. Nuussuaq basin of west Greenland: Subsidence and structural inversion in an Albian - early Tertiary pull-apart basin

    SciTech Connect

    Tankard, A. ); Ng, T. ) Renner, T. )

    1996-01-01

    The western margin of Greenland consists of a complex of linked extensional basins which formed during opening of Labrador Sea and Baffin Bay in Albian - early Tertiary time. The Nuussuaq basin, which straddles Nuussuaq peninsula and Disko Island, is onshore. Its sedimentary succession is generally hidden beneath a cover of early Tertiary extrusives. Slim-hole exploration drilling has been based on an integrated basin analysis and magnetotelluric data acquisition. Nuussuaq basin developed at a left-lateral releasing stepover at the end of the Ungava fault, an interplate strike-slip fault zone. SW-directed extension was accommodated by several transfer faults which compartmented the Nuussuaq basin. Although the principal depocenter is only 1500 km[sup 2] in area, interpretation of the magnetotelluric: data shows basin depths greater than 10 km. Persistent overpressuring and the low resistivity lower basin fill are believed to be typical of a young basin which has subsided rapidly. The Cretaceous - lower Tertiary succession is indicative of a restricted, underfilled basin. In contrast, the mid-Paleocene paleogeography was controlled by dextral slip along the basement strike-slip fault zones, broadscale structural inversion of the earlier extensional faults, and widespread volcanism. Catastrophic crestal collapse of inversion anticlines is reflected in sudden incision and rapid filling of a suite of paleovalleys. In Paleocene time, the Nuussuag basin was generally overfilled and dominated by terrestrial depositional systems. Oil seeps are associated with crestal collapse and fracturing of inversion structures. Biomarkers suggest a source rock of Paleocene age.

  2. Nuussuaq basin of west Greenland: Subsidence and structural inversion in an Albian - early Tertiary pull-apart basin

    SciTech Connect

    Tankard, A.; Ng, T. Renner, T.

    1996-12-31

    The western margin of Greenland consists of a complex of linked extensional basins which formed during opening of Labrador Sea and Baffin Bay in Albian - early Tertiary time. The Nuussuaq basin, which straddles Nuussuaq peninsula and Disko Island, is onshore. Its sedimentary succession is generally hidden beneath a cover of early Tertiary extrusives. Slim-hole exploration drilling has been based on an integrated basin analysis and magnetotelluric data acquisition. Nuussuaq basin developed at a left-lateral releasing stepover at the end of the Ungava fault, an interplate strike-slip fault zone. SW-directed extension was accommodated by several transfer faults which compartmented the Nuussuaq basin. Although the principal depocenter is only 1500 km{sup 2} in area, interpretation of the magnetotelluric: data shows basin depths greater than 10 km. Persistent overpressuring and the low resistivity lower basin fill are believed to be typical of a young basin which has subsided rapidly. The Cretaceous - lower Tertiary succession is indicative of a restricted, underfilled basin. In contrast, the mid-Paleocene paleogeography was controlled by dextral slip along the basement strike-slip fault zones, broadscale structural inversion of the earlier extensional faults, and widespread volcanism. Catastrophic crestal collapse of inversion anticlines is reflected in sudden incision and rapid filling of a suite of paleovalleys. In Paleocene time, the Nuussuag basin was generally overfilled and dominated by terrestrial depositional systems. Oil seeps are associated with crestal collapse and fracturing of inversion structures. Biomarkers suggest a source rock of Paleocene age.

  3. Bruce Plateau, Antarctic Peninsula: Ice-Core Site Characterization

    NASA Astrophysics Data System (ADS)

    Pettit, E. C.; Scambos, T. A.; Bauer, R. J.; Mosley-Thompson, E. S.; Truffer, M.; Blair, B.

    2010-12-01

    The Bruce Plateau is a broad, gently-undulating ice plateau spanning the divide of the Antarctic Peninsula near 66°S. The western side is the catchment area for the glaciers of numerous inlet fjords such as Andvord Bay, Beascochea Bay, and Barilari Bay. The eastern side is the catchment area for the glaciers of the southern Larsen B Ice Shelf and northern Larsen C Ice Shelf. Because it is the catchment for the Larsen B, the Bruce Plateau was chosen as a site to drill an ice core for paleoclimate studies. We present the results of a site characterization study of a 10 km × 10 km area near the ridge crest. We mapped surface topography using the LVIS (Laser Vegetation Imaging Sensor) instrument collected as part of NASA’s Ice Bridge program and extended these data using ground-based kinematic GPS profiles. We mapped bedrock topography through a 5 MHz Radio Echo Sounding (RES) survey. A weather station augmented with firn temperature sensors and C/A code GPS was installed at the ice-core site in February 2010 and was active for 5 months. We measured the spatial accumulation rate pattern and internal structure of the ice to 400 m with a 25 MHz RES survey near the ice-core site. The RES-mapped relative accumulation pattern was tied to measurements at the weather station, a temporary stake network, and data from the ice core. The surface topography data show that the crest of the ice divide ranges from 1980 to 2020 m above the ellipsoid, with surfaces sloping at 0.047 to the northeast (Leppard Glacier catchment) and approximately 0.04 to the southwest (Atlee Glacier). The bedrock topography consists of two hills of a few hundred meters relief, with deeper troughs under the regions leading to both Leppard and Atlee Glaciers. Ice thickness ranges from 200 m above the hills to more than 700 m deep in the troughs, as determined by a 5 MHz RES system. To the west of the hills, bedrock slopes gently downward, while surface elevation increases to the crest. This suggests

  4. Byers Peninsula: A reference site for coastal, terrestrial and limnetic ecosystem studies in maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Quesada, A.; Camacho, A.; Rochera, C.; Velázquez, D.

    2009-11-01

    This article describes the development of an international and multidisciplinary project funded by the Spanish Polar Programme on Byers Peninsula (Livingston Island, South Shetlands). The project adopted Byers Peninsula as an international reference site for coastal and terrestrial (including inland waters) research within the framework of the International Polar Year initiative. Over 30 scientists from 12 countries and 26 institutions participated in the field work, and many others participated in the processing of the samples. The main themes investigated were: Holocene changes in climate, using both lacustrine sediment cores and palaeo-nests of penguins; limnology of the lakes, ponds, rivers and wetlands; microbiology of microbial mats, ecology of microbial food webs and viral effects on aquatic ecosystems; ornithology, with investigations on a Gentoo penguin rookery ( Pygoscelis papua) as well as the flying ornithofauna; biocomplexity and life cycles of species from different taxonomic groups; analysis of a complete watershed unit from a landscape perspective; and human impacts, specifically the effect of trampling on soil characteristics and biota. Byers Peninsula offers many features as an international reference site given it is one of the largest ice-free areas in the Antarctic Peninsula region, it has a variety of different landscape units, and it hosts diverse aquatic ecosystems. Moreover, the Byers Peninsula is a hotspot for Antarctic biodiversity, and because of its high level of environmental protection, it has been very little affected by human activities. Finally, the proximity to the Spanish polar installations on Livingston Island and the experience derived from previous expeditions to the site make it logistically feasible as a site for ongoing monitoring and research.

  5. Proposed Mars Surveyor 2001 Landing Site at 'Ibishead Peninsula', Southern Elysium Planitia

    NASA Technical Reports Server (NTRS)

    Parker, T. J.; Rice, J. W., Jr.

    1999-01-01

    Our objective is to propose a landing site that the Mars Surveyor 2001 Lander and Curie Rover could go to on Mars that should meet the safety requirements of the spacecraft landing system and optimize surface operations (chiefly driven by power and communications requirements). This site lies between 1.5-3.5 deg S latitude, 195-198 deg W longitude, along a sharp albedo contact between the low-viscosity flow units of southern Elysium Planitia and the eroded highlands margin east of Aeolis Mensae. A relatively-bright "peninsula-like" protrusion of the eroded highlands into the south Elysium plains in this area reminds us of the head of an Ibis, and so we nickname this site "Ibishead Peninsula". This site is designed to be situated as close to a diversity of geologic units within view of the lander instruments. Based on our experience with the visibility of horizon details from the Mars Pathfinder and Viking landing sites, we stipulate that for horizon features to be resolved suitably for detailed study from the lander, they must be no more than several kilometers distant. This is so that diversity can be placed in a geologic context in a region that we feel has some exciting science potential. This objective is different from the Mars Pathfinder requirement to land at a site with a maximum chance for containing a diversity of rocks within a few tens of meters of the lander, which resulted in the selection of a "grab bag" site.

  6. Investigations of fungal diversity in wooden structures and soils at historic sites on the Antarctic Peninsula.

    PubMed

    Arenz, Brett E; Blanchette, Robert A

    2009-01-01

    Investigations of microbial diversity in Antarctic are important to begin to understand ecosystem functioning and decomposition processes. This study documents fungi at 9 historic sites on the Antarctic Peninsula collected from wooden structures, other organic materials, and soils during a joint National Science Foundation and British Antarctic Survey expedition in 2007. Many of these sites had wooden structures built by the British during the World War II Operation Tabarin, but others visited included the American "East Base" on Stonington Island and the Swedish hut on Snow Hill Island. Fungi were cultured on several different media and pure cultures were obtained and identified by DNA sequencing of the internal transcribed spacer region. Cadophora species previously found to attack historic wooden structures on Ross Island, Antarctica, were found at all but 1 location sampled in the Peninsula region. Fungi causing decay in the historic wooden structures and artifacts and those causing mold problems inside the structures are of great concern, and conservation efforts are urgently needed to help preserve these important polar heritage structures. The results presented also expand our knowledge on the identity of fungi present throughout the Antarctic Peninsula region and provide insights into the organisms responsible for decomposition and nutrient recycling.

  7. Impact of medium-distance pollution sources in a Galician suburban site (NW Iberian peninsula).

    PubMed

    Gómez-Carracedo, M P; Andrade, J M; Ballabio, D; Prada-Rodríguez, D; Muniategui-Lorenzo, S; Consonni, V; Piñeiro-Iglesias, M; López-Mahía, P

    2015-04-15

    This work studies airborne quality in a geographical area that has not been investigated broadly: a suburban site nearby A Coruña (Galicia, NW Iberian Peninsula). In contrast to major Spanish cities, the site has Atlantic characteristics: rainy, scarce calm weather and infrequent prolonged sunny periods. The relationships between several gaseous pollutants (NO, NO2, NOx, CO, O3, PM10, PM2.5 and PM1) and their temporal trends (daily, monthly and seasonal) were evaluated. The aim was to unravel whether medium- and long-distance sources were impacting upon the site. Univariate studies focused on factorizing the pollutants according to a codifying factor (wind direction, hour of the day, season and month). Multivariate studies (Varimax-rotated factorial analysis) were done separately on both weekdays and weekends. The intensity of the daily maxima for NO, NO2, NOx and CO was lower during the weekends, with O3 behaving opposite. PM average values agreed with previous historical reports for a rural background station relatively close to the site and they decreased daily between 11:00 and 19:00 h, likely because of the marine breeze. With moderate wind speeds the pollutants were associated to medium-distance pollution sources, mainly the city of A Coruña and a combination of industrial pollution sources (a power plant, a solid waste incinerator and a regional airport).

  8. Impact of medium-distance pollution sources in a Galician suburban site (NW Iberian peninsula).

    PubMed

    Gómez-Carracedo, M P; Andrade, J M; Ballabio, D; Prada-Rodríguez, D; Muniategui-Lorenzo, S; Consonni, V; Piñeiro-Iglesias, M; López-Mahía, P

    2015-04-15

    This work studies airborne quality in a geographical area that has not been investigated broadly: a suburban site nearby A Coruña (Galicia, NW Iberian Peninsula). In contrast to major Spanish cities, the site has Atlantic characteristics: rainy, scarce calm weather and infrequent prolonged sunny periods. The relationships between several gaseous pollutants (NO, NO2, NOx, CO, O3, PM10, PM2.5 and PM1) and their temporal trends (daily, monthly and seasonal) were evaluated. The aim was to unravel whether medium- and long-distance sources were impacting upon the site. Univariate studies focused on factorizing the pollutants according to a codifying factor (wind direction, hour of the day, season and month). Multivariate studies (Varimax-rotated factorial analysis) were done separately on both weekdays and weekends. The intensity of the daily maxima for NO, NO2, NOx and CO was lower during the weekends, with O3 behaving opposite. PM average values agreed with previous historical reports for a rural background station relatively close to the site and they decreased daily between 11:00 and 19:00 h, likely because of the marine breeze. With moderate wind speeds the pollutants were associated to medium-distance pollution sources, mainly the city of A Coruña and a combination of industrial pollution sources (a power plant, a solid waste incinerator and a regional airport). PMID:25616227

  9. New Neanderthal remains from Mani peninsula, Southern Greece: the Kalamakia Middle Paleolithic cave site.

    PubMed

    Harvati, Katerina; Darlas, Andreas; Bailey, Shara E; Rein, Thomas R; El Zaatari, Sireen; Fiorenza, Luca; Kullmer, Ottmar; Psathi, Eleni

    2013-06-01

    The Kalamakia cave, a Middle Paleolithic site on the western coast of the Mani peninsula, Greece, was excavated in 1993-2006 by an interdisciplinary team from the Ephoreia of Paleoanthropology and Speleology (Greek Ministry of Culture) and the Muséum national d'Histoire naturelle (Paris). The site is dated to between ca. 100,000 and >39,000 years BP (Before Present) and has yielded Mousterian lithics, a rich fauna, and human remains from several layers. The latter include 10 isolated teeth, a cranial fragment and three postcranial elements. The remains represent at least eight individuals, two of them subadults, and show both carnivore and anthropogenic modifications. They can be identified as Neanderthal on the basis of diagnostic morphology on most specimens. A diet similar to that of Neanderthals from mixed habitat is suggested by our analysis of dental wear (occlusal fingerprint analysis) and microwear (occlusal texture microwear analysis), in agreement with the faunal and palynological analyses of the site. These new fossils significantly expand the Neanderthal sample known from Greece. Together with the human specimens from Lakonis and Apidima, the Kalamakia human remains add to the growing evidence of a strong Neanderthal presence in the Mani region during the Late Pleistocene. PMID:23490263

  10. Thermal regime of active layer at two lithologically contrasting sites on James Ross Island, Antarctic Peninsula.

    NASA Astrophysics Data System (ADS)

    Hrbáček, Filip; Nývlt, Daniel; Láska, Kamil

    2016-04-01

    Antarctic Peninsula region (AP) represents one of the most rapidly warming parts of our planet in the last 50 years. Despite increasing research activities along both western and eastern sides of AP in last decades, there is still a lot of gaps in our knowledge relating to permafrost, active layer and its thermal and physical properties. This study brings new results of active layer monitoring on James Ross Island, which is the largest island in northern AP. Its northern part, Ulu Peninsula, is the largest ice-free area (more than 200 km2) in the region. Due its large area, we focused this study on sites located in different lithologies, which would affect local thermal regime of active layer. Study site (1) at Abernethy Flats area (41 m a.s.l.) lies ~7 km from northern coast. Lithologically is formed by disintegrated Cretaceous calcareous sandstones and siltstones of the Santa Marta Formation. Study site (2) is located at the northern slopes of Berry Hill (56 m a.s.l.), about 0.4 km from northern coastline. Lithology is composed of muddy to intermediate diamictites, tuffaceous siltstones to fine grained sandstones of the Mendel Formation. Data of air temperature at 2 meters above ground and the active layer temperatures at 75 cm deep profiles were obtained from both sites in period 1 January 2012 to 31 December 2014. Small differences were found when comparing mean air temperatures and active temperatures at 5 and 75 cm depth in the period 2012-2014. While the mean air temperatures varied between -7.7 °C and -7.0 °C, the mean ground temperatures fluctuated between -6.6 °C and -6.1 °C at 5 cm and -6.9 °C and -6.0 °C at 75 cm at Abernethy Flats and Berry Hill slopes respectively. Even though ground temperature differences along the profiles weren't pronounced during thawing seasons, the maximum active layer thickness was significantly larger at Berry Hill slopes (80 to 82 cm) than at Abernethy Flats (52 to 64 cm). We assume this differences are affected by

  11. The Punta Lucero Quarry site (Zierbena, Bizkaia): a window into the Middle Pleistocene in the Northern Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Gómez-Olivencia, Asier; Sala, Nohemi; Arceredillo, Diego; García, Nuria; Martínez-Pillado, Virginia; Rios-Garaizar, Joseba; Garate, Diego; Solar, Gonzalo; Libano, Iñaki

    2015-08-01

    The period between the end of the Early Pleistocene and the mid-Middle Pleistocene (roughly between 1.0 and 0.4 Ma BP) is of great interest in Western Europe. It witnessed several climatic oscillations and changes in the fauna, the demise of a hominin species and the appearance of another, along with important cultural and technological changes. Thus, the few available sites with these chronologies is vital to the understanding of the tempo and mode of these changes. Middle Pleistocene sites in the Northern Iberian Peninsula are very rare. Here we present the study of the site found at the Punta Lucero Quarry (Biscay province, Northern Iberian Peninsula), which includes for the first time the complete collection from the site. The fossil association from this site includes several ungulates, such as a Megacerine deer, Cervus elaphus, large bovids (likely both Bos primigenius and Bison sp. are present), Stephanorhinus sp., and carnivores, such as Homotherium latidens, Panthera gombaszoegensis, Canis mosbachensis and Vulpes sp. This association is typical of a middle Middle Pleistocene chronology and would be the oldest macro-mammal site in the Eastern Cantabrian region. This site would likely correspond to a chronology after Mode 1 technological complex and before the arrival of Mode 2 technology in this region. Thus, it offers a glimpse into the paleoecological conditions slightly prior to or contemporaneous with the first Acheulian makers in the northern fringe of the Iberian Peninsula.

  12. Site Fidelity in Space Use by Spider Monkeys (Ateles geoffroyi) in the Yucatan Peninsula, Mexico

    PubMed Central

    Ramos-Fernandez, Gabriel; Smith Aguilar, Sandra E.; Schaffner, Colleen M.; Vick, Laura G.; Aureli, Filippo

    2013-01-01

    Animal home ranges may vary little in their size and location in the short term but nevertheless show more variability in the long term. We evaluated the degree of site fidelity of two groups of spider monkeys (Ateles geoffroyi) over a 10- and 13-year period, respectively, in the northeastern Yucatan peninsula, Mexico. We used the Local Convex Hull method to estimate yearly home ranges and core areas (defined as the 60% probability contour) for the two groups. Home ranges varied from 7.7 to 49.6 ha and core areas varied from 3.1 to 9.2 ha. We evaluated the degree of site fidelity by quantifying the number of years in which different areas were used as either home ranges or core areas. Large tracts were used only as home ranges and only for a few years, whereas small areas were used as either core area or home range for the duration of the study. The sum of the yearly core areas coincided partially with the yearly home ranges, indicating that home ranges contain areas used intermittently. Home ranges, and especially core areas, contained a higher proportion of mature forest than the larger study site as a whole. Across years and only in one group, the size of core areas was positively correlated with the proportion of adult males in the group, while the size of home ranges was positively correlated with both the proportion of males and the number of tree species included in the diet. Our findings suggest that spider monkey home ranges are the result of a combination of long-term site fidelity and year-to-year use variation to enable exploration of new resources. PMID:23675427

  13. Site fidelity in space use by spider monkeys (Ateles geoffroyi) in the Yucatan peninsula, Mexico.

    PubMed

    Ramos-Fernandez, Gabriel; Smith Aguilar, Sandra E; Schaffner, Colleen M; Vick, Laura G; Aureli, Filippo

    2013-01-01

    Animal home ranges may vary little in their size and location in the short term but nevertheless show more variability in the long term. We evaluated the degree of site fidelity of two groups of spider monkeys (Ateles geoffroyi) over a 10- and 13-year period, respectively, in the northeastern Yucatan peninsula, Mexico. We used the Local Convex Hull method to estimate yearly home ranges and core areas (defined as the 60% probability contour) for the two groups. Home ranges varied from 7.7 to 49.6 ha and core areas varied from 3.1 to 9.2 ha. We evaluated the degree of site fidelity by quantifying the number of years in which different areas were used as either home ranges or core areas. Large tracts were used only as home ranges and only for a few years, whereas small areas were used as either core area or home range for the duration of the study. The sum of the yearly core areas coincided partially with the yearly home ranges, indicating that home ranges contain areas used intermittently. Home ranges, and especially core areas, contained a higher proportion of mature forest than the larger study site as a whole. Across years and only in one group, the size of core areas was positively correlated with the proportion of adult males in the group, while the size of home ranges was positively correlated with both the proportion of males and the number of tree species included in the diet. Our findings suggest that spider monkey home ranges are the result of a combination of long-term site fidelity and year-to-year use variation to enable exploration of new resources.

  14. Comprehensive paleoseismic geological studies in a key site in southwestern Kola Peninsula (Northeast of the Fennoscandian Shield)

    NASA Astrophysics Data System (ADS)

    Nikolaeva, S. B.; Nikonov, A. A.; Shvarev, S. V.; Rodkin, M. V.

    2016-07-01

    This paper considers the results of detailed paleoseismic and geological investigations in a key site in the wall of the Imandra Lake depression (Kola Peninsula Region, Northeast of the Fennoscandian Shield). Study of different groups of paleoseismic deformations developed in the fault zone and the application of new methods and techniques made it possible to identify a large seismotectonic zone characterized by great earthquakes at the end of the Late Glacial and in the Holocene. The investigation data are indicative of the necessity to estimate the seismic potential in the Kola Atomic plant area in a different way.

  15. CO 2 metasomatism in a basalt-hosted petroleum reservoir, Nuussuaq, West Greenland

    NASA Astrophysics Data System (ADS)

    Rogers, Karyn L.; Neuhoff, Philip S.; Pedersen, Asger K.; Bird, Dennis K.

    2006-11-01

    Extensive subaerial exposures of a basalt-hosted petroleum reservoir around Marraat Killiit on Nuussuaq, West Greenland, provide an unparalleled opportunity to investigate water-rock-hydrocarbon interactions in an unconventional petroleum system. Exposed sections in this locality include picritic and olivine-phyric basalts, with both subaerial and subaqueous textures that initially had significant primary porosity in the form of gas vesicles, scorias, and interclast voids within hyaloclastites. Alteration of these low-silica, high-magnesium basalts formed regionally-extensive, silica-deficient zeolite-facies mineral assemblages that dominantly consist of mixed-layer chlorite/smectite clays, thomsonite, natrolite, gonnardite, analcime and chabazite. In the study area, faulting and fracturing allowed petroleum migration from sediments into the overlying basalts. Migration of petroleum and the associated brine led to the pseudomorphic replacement of zeolite and clay mineral assemblages by carbonates (siderite, magnesite, dolomite and calcite) and quartz. Carbonates associated with petroleum migration are rich in Mg and Fe, reflecting the interaction of a CO 2-rich fluid with a picritic basalt and associated Fe- and Mg-rich smectites. Only late stage carbonates are calcium-rich, the result of depletion of aqueous magnesium and iron following precipitation of magnesite-siderite solid solutions. Values of δ13C vPDB and δ18O vSMOW of carbonates at Marraat form two distinct groups: (1) paragenetically early dolomite veins and magnesite-siderite replacement of low-grade metamorphic minerals that have δ18O vSMOW between 12.6 and 20‰ and δ13C vPDB in the approximate range of 0 ± 5‰, and (2) late stage calcite veins that are lighter in 18O ( δ18O vSMOW between 6.4 and 8.7‰) and have a restricted range of δ13C vPDB that is near zero. Comparison with isotopic properties of carbonates from petroleum reservoirs worldwide and carbonates formed from meteoric water in

  16. Annual survival and site fidelity of Steller's eiders molting along the Alaska Peninsula

    USGS Publications Warehouse

    Flint, P.L.; Petersen, M.R.; Dau, C.P.; Hines, J.E.; Nichols, J.D.

    2000-01-01

    Populations of Steller's eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (??SE) were 0.899 ?? 0.032 for females and 0.765 ?? 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

  17. Annual survival and site fidelity of Stellar's Eiders molting along the Alaska Peninsula

    USGS Publications Warehouse

    Flint, P.L.; Petersen, M.R.; Dau, C.P.; Hines, J.E.; Nichols, J.D.

    2000-01-01

    Populations of Steller?s eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (?SE) were 0.899 ? 0.032 for females and 0.765 ? 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

  18. Alluvial systems as archives for environmental change at a Hominid site with Oldowan archaeological occurrences: the Homa Peninsula, southwestern Kenya

    NASA Astrophysics Data System (ADS)

    Vincent, Thomas; Whitfield, Elizabeth; Kirby, Jason; Hunt, Christopher; Bishop, Laura; Plummer, Thomas; Ditchfield, Peter

    2016-04-01

    The Homa Peninsula, southwestern Kenya, preserves fossiliferous sedimentary sequences dating to the Plio-Pleistocene. Evidence of hominids inhabiting an open grassland setting and utilising Oldowan tools has been reported here, as well as some of the oldest known traces of hominin activity. Reconstructions of the palaeoenvironment have suggested that alluvial and lake marginal environments on a grassy plain, between wooded slopes and a permanent water body might be plausible. However, these interpretations are based only on field sedimentological analyses and stable isotope analysis at a single site on the peninsula (Kanjera South). It is the aim of this study to utilise a multiproxy approach to develop our understanding of the palaeoenvironmental characteristics here. Sediments will also be characterized at a new site (Nyayanga) through field analyses, as well as through analyses of particle size, siliceous microfossils (diatoms, phytoliths and sponge spicules), pollen and stable isotopes. By utilizing this approach, new insights into the palaeoecology, palaeohydromorphology and palaeoclimate of the locale may be revealed, expanding the limited data available to palaeoanthropological studies of Oldowan occurrences in east Africa. Efforts to refine palaeoenvironmental reconstructions of Kanjera South through particle size analysis have shown that sediments in the lower beds of the sequence are characterised by poor sorting, a bimodal distribution and sand/silty-sand grade material. This suggests rapid deposition and/or a variable hydrological regime and may represent the role of relatively unconfined ephemeral channels in the transportation and deposition of sediments. Fluvial reworking of aeolian sediments, most likely during unconfined flood events may also have occurred.

  19. Application of radium isotopes to determine crustal residence times of hydrothermal fluids from two sites on the Reykjanes Peninsula, Iceland

    NASA Astrophysics Data System (ADS)

    Kadko, David; Gronvold, Karl; Butterfield, David

    2007-12-01

    Radium isotopes were used to determine the crustal residence times of hydrothermal fluids from two geothermal wells (Svartsengi and Reykjanes) from the Reykjanes Peninsula, Iceland. The availability of rock samples from the subsurface (to depths of 2400 m) allowed direct comparison of the radium isotopic characteristics of the fluids with those of the rocks within the high temperature and pressure reaction zone. The 226Ra activity of the Svartsengi fluid was ˜one-fourth of the Reykjanes fluid and the 228Ra/ 226Ra ratio of the Svartsengi fluid was ˜twice that of Reykjanes. The fluid isotopic characteristics were relatively stable for both sites over the 6 years (2000-2006) of the study. It was determined, using a model that predicts the evolution of the fluid 228Ra/ 226Ra ratio with time, that both sites had fluid residence times, from the onset of high temperature water-rock reaction, of less than 5 years. Measurement of the short-lived 224Ra and 223Ra allowed estimation of the recoil input parameter used in the model. The derived timescale is consistent with results from similar studies of fluids from submarine systems, and has implications for the use of terrestrial systems in Iceland as an exploited energy resource.

  20. ALERTES-SC3 Early Warning System prototype for South Iberian Peninsula: on-site approach.

    NASA Astrophysics Data System (ADS)

    Pazos, Antonio; Lopez de Mesa, Mireya; Gallego Carrasco, Javier; Martín Davila, José; Rioja del Rio, Carlos; Morgado, Arturo; Vera, Angel; Ciberia, Angel; Cabieces, Roberto; Strollo, Angelo; Hanka, Winfried; Carranza, Marta

    2016-04-01

    In recent years several Earthquake Early Warning Systems (EEWS) have been developed for different parts of the world. The area between SW Cape St. Vicente and the Strait of Gibraltar is one of the most seismically active zones in the Ibero-Maghrebian region, with predominantly moderate and superficial seismicity, but also big events with associated tsunamis are well documented in the area, like the 1755 Lisbon earthquake. In the frame of the ALERT-ES (2011-2013) and ALERTES-RIM (2014-2016) Spanish projects, the ALERTES-SC3 EEWS, regional approach, prototype has been developed at the Royal Spanish Navy Observatory (ROA) and is being tested in near real time for south Iberia. This prototype, based on the SeisComP3 software package, is largely based on algorithms derived from the analysis of the first seconds of the P wave records. Calculation of several parameters are carried out, mainly the characteristic period (τc) and the displacement peak (Pd), but also the velocity peak (Pv), the maximum period (τPmáx), among others. In order to warm the areas closest to the hypocentre, places located inside the "blind zone", a on-site EEWS has also been developed by ROA and integrated in the ALERTES-SC3 prototype. From the on-site approach, a warm level is declared from one station as a function of the estimated characteristic period (τc) and the displacement Peak (Pd), although the earthquake location and therefore the lead time available remains unknown. This on-site EEWS is being tested in several Western Mediterranean net (WM) stations as ARNO (Arenosillo, Huelva,Spain) or CHAS (Chafarinas island, North Africa, Spain). Also an on-site low cost station is being developed based in low cost accelerometers. In this work the current state of the on-site EEWS developed, its integration in the ALERTES-SC3 EEWS system and the low cost seismic stations are shown.

  1. Study on the Application of Probabilistic Tsunami Hazard Analysis for the Nuclear Power Plant Site in Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Rhee, H. M.; Kim, M.; Sheen, D. H.; Choi, I. K.

    2014-12-01

    The necessity of study on the tsunami hazard assessment for Nuclear Power Plant (NPP) site was suggested since the event of Fukushima in 2011 had been occurred. It has being emphasized because all of the NPPs in Korean Peninsula are located in coastal region. The tsunami hazard is regarded as the annual exceedance probability for the wave heights. The methodology for analysis of tsunami hazard is based on the seismic hazard analysis. The seismic hazard analysis had been performed by using both deterministic and probabilistic method. Recently, the probabilistic method had been received more attention than the deterministic method because the uncertainties of hazard analysis could be considered by using the logic tree approach. In this study, the probabilistic tsunami hazard analysis for Uljin NPP site was performed by using the information of fault sources which was published by Atomic Energy Society of Japan (AESJ). The wave parameter is the most different parameter with seismic hazard. It could be estimated from the results of tsunami propagation analysis. The TSUNAMI_ver1.0 which was developed by Japan nuclear energy safety organization (JNES), was used for the tsunami simulation. The 80 cases tsunami simulations were performed and then the wave parameters were estimated. For reducing the sensitivity which was encouraged by location of sampling point, the wave parameters were estimated from group of sampling points.The probability density function on the tsunami height was computed by using the recurrence intervals and the wave parameters. And then the exceedance probability distribution was calculated from the probability density function. The tsunami hazards for the sampling groups were calculated. The fractile curves which were shown the uncertainties of input parameters were estimated from the hazards by using the round-robin algorithm. In general, tsunami hazard analysis is focused on the maximum wave heights. But the minimum wave height should be considered

  2. Atmospheric behaviors of polycyclic aromatic hydrocarbons at a Japanese remote background site, Noto peninsula, from 2004 to 2014

    NASA Astrophysics Data System (ADS)

    Tang, Ning; Hakamata, Mariko; Sato, Kousuke; Okada, Yumi; Yang, Xiaoyang; Tatematsu, Michiya; Toriba, Akira; Kameda, Takayuki; Hayakawa, Kazuichi

    2015-11-01

    Total suspended particulates were collected at a Japanese remote background site (Noto Air Monitoring Station; NAMS) on the Noto Peninsula from September 2004 to June 2014. Nine polycyclic aromatic hydrocarbons (PAHs) in the particulates (fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene and indeno[1,2,3-cd]pyrene) were determined by HPLC with fluorescence detection. The mean total concentrations of the nine PAHs in the cold season (November to May for the years 2004-2014) was 670 pg m-3 (range 37-4100 pg m-3). The mean total concentration in the warm season (June to October for the same period) was 170 pg m-3 (range 31-960 pg m-3). The atmospheric PAH level at NAMS decreased in recent years, although no significant change was found in the warm season. An analysis of meteorological conditions showed that the atmospheric PAHs at NAMS were long range transported from Northeast China in the cold seasons and were contributed to by Japanese domestic sources in the warm seasons. Lower concentration ratios of reactive PAHs to their isomers at NAMS also supported these results. Activities associated with the Beijing Olympic and Paralympic Games in 2008 and reconstruction after the 2007 Noto Hanto earthquake may have contributed to the yearly variations of atmospheric PAH levels at NAMS during the period 2007-2009. Source control measures implemented by the Chinese and Japanese governments appear to have been effective in decreasing the atmospheric PAH levels at NAMS in recent years.

  3. Data Report: A Search for Deposits of the Late Pliocene Impact of the Eltanin Asteroid in Rise Sediments from the Antarctic Peninsula, Site 1096

    NASA Technical Reports Server (NTRS)

    Kyte, Frank T.

    2003-01-01

    Concentrations of Ir have been measured in 87 sediment samples from Ocean Drilling Program Site 1096 in search of evidence of fallout from the impact of the Eltanin asteroid, which occurred at 2.15 Ma, approx. 1300 km northwest of the site. An additional six samples were measured from a unique sand layer and adjacent sediments that are dated at approx. 1.6 Ma. These 93 sediment samples are all silts and muds that were deposited on a continental rise drift of the Antarctic Peninsula. No evidence of the Eltanin impact deposit was found in this study.

  4. Horizontal and vertical distribution of euphausiid species on the Western Antarctic Peninsula U.S. GLOBEC Southern Ocean study site

    NASA Astrophysics Data System (ADS)

    Wiebe, Peter H.; Ashjian, Carin J.; Lawson, Gareth L.; Piñones, Andrea; Copley, Nancy J.

    2011-07-01

    The Western Antarctic Peninsula (WAP) is a site of high krill abundance and a likely source region for krill populations found to the north and east of the area. The U.S. GLOBEC Southern Ocean program studied factors that contribute to the overwintering success of krill in the region of Marguerite Bay, WAP. A MOCNESS net system was used to sample the vertical distribution and abundance of zooplankton relative to physical features (hydrography and circulation) during four broad-scale survey cruises in the fall and winter of 2001 and 2002. Four species were found throughout the study area on all four cruises: Euphausia superba, Euphausia crystallorophias, Euphausia triacantha, and Thysanoessa macrura. The species had significantly different horizontal and vertical distributions. Both E. superba and T. macrura were broadly distributed throughout the area, but the central 50% of their vertical distributions were distinct with E. superba most abundant in the upper 100 m in the coldest, freshest water (average temperature and salinity: -1.13 °C; 33.80) and T. macrura occurring between 100 and 250 m (at 0.01 °C; 34.228). E. crystallorophias had a more coastal distribution and was usually found deeper in slightly warmer and saltier water (-0.44 °C; 33.9982) than E. superba and either overlapped or was above T. macrura in depth. E. triacantha was much rarer and sporadically distributed in the study area and was found substantially deeper (center of distribution about 300 m) in the warmest saltiest water (1.40 °C; 34.65) than the other three euphausiid species. Larval distributions for E. superba indicated that at least some proportion of the populations resulted from reproduction and development on the continental shelf, and not solely from offshore reproduction and transport onto the shelf. A neutral particle tracking model was used to gain insight into the relative importance of shelf versus off-shelf origins for the larvae. The results suggest that a combination of

  5. A study of a possible early reindeer domestication site on the Iamal peninsula (Russia) using geoarchaeological methods and lipid biomarkers.

    NASA Astrophysics Data System (ADS)

    Harrault, Loic; Milek, Karen; Dawson, Lorna; Anderson, David

    2016-04-01

    In past centuries, indigenous hunters in Northern Eurasia shifted from being hunters to being herders of reindeer. Even at low human population densities, large reindeer herds can alter the landscape and leave long-term biochemical signatures in the soil. Although indigenous social-ecological systems have been thought to be resilient in space and time, most are considered to be at risk due to climate and socio-economic changes related to anthropogenic activities. This situation calls for a long-term perspective to place human-animal relations in their respective contexts. As an ancient livelihood still practiced across vast areas of Northern Eurasia, reindeer herding is a nexus for feedbacks between humans, animals and environment. The Iarte site, on the Iuribei River in the central part of the Iamal peninsula is thought to be an important site of reindeer domestication dating back to the 12th century due to the enormous quantities of butchered reindeer bones found in recent excavations. The large amount of buried reindeer bones found at the settlement suggests that herds should have stood near the site despite the lack of any architectural remains of corrals or pens. The history of a possible early relation to domesticate reindeer can be described with geoarchaeological methods, including lipid biomarkers, which can indicate the presence of past human and animal activities. Among lipid biomarkers, faecal markers such as stanols and bile acids have already been used in archaeological contexts to identify and distinguish between different species because they are persistent over time and can have a species specific profile. Near the Iarte settlement, we conducted a soil survey and sampling programme and combined geoarchaeological measurements (including electrical conductivity, magnetic susceptibility and elemental analysis) with lipid analysis of soil samples, to identify the potential presence of standing reindeer herds. The different soil layers have been

  6. Light absorption and morphological properties of soot-containing aerosols observed at an East Asian outflow site, Noto Peninsula, Japan

    NASA Astrophysics Data System (ADS)

    Ueda, S.; Nakayama, T.; Taketani, F.; Adachi, K.; Matsuki, A.; Iwamoto, Y.; Sadanaga, Y.; Matsumi, Y.

    2015-09-01

    The coating of black carbon (BC) with inorganic salts and organic compounds can enhance the magnitude of light absorption by BC. To elucidate the enhancement of light absorption of aged BC particles and its relation to the mixing state and morphology of individual particles, we conducted observations of particles at an Asian outflow site in Noto Peninsula, Japan, in the spring of 2013. Absorption and scattering coefficients at 405, 532, and 781 nm and mass concentrations/mixing states of refractory-BC in PM2.5 were measured using a three-wavelength photoacoustic soot spectrometer and a single-particle soot photometer (SP2), respectively, after passage through a heater maintained at 300 or 400 °C or a bypass line maintained at room temperature (25 °C). The average enhancement of BC light absorption due to coating was estimated by comparing absorption coefficients at 781 nm for particles that with and without passing through the heater and was found to be 22-23 %. The largest enhancements (> 30 %) were observed under high absorption coefficient conditions when the air mass was long-range transported from urban areas in China. Aerosol samples were also analyzed using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer. The morphological features and mixing states of soot-containing particles of four samples collected during the high absorption coefficient events were analyzed by comparing microphotographs before and after the evaporation of beam-sensitive materials by irradiation with a high density electron beam. The majority of the soot in all samples was found as mixed particles with spherical sulfate or as clusters of sulfate spherules. For samples showing high enhancement (> 30 %) of BC light absorption, TEM showed that the internally mixed soot-containing particles tended to have a more spherical shape and to be embedded into the sulfate. The SP2 measurements also suggested that the proportion of thickly-coated soot was

  7. Light absorption and morphological properties of soot-containing aerosols observed at an East Asian outflow site, Noto Peninsula, Japan

    NASA Astrophysics Data System (ADS)

    Ueda, Sayako; Nakayama, Tomoki; Taketani, Fumikazu; Adachi, Kouji; Matsuki, Atsushi; Iwamoto, Yoko; Sadanaga, Yasuhiro; Matsumi, Yutaka

    2016-03-01

    The coating of black carbon (BC) with inorganic salts and organic compounds can enhance the magnitude of light absorption by BC. To elucidate the enhancement of light absorption of aged BC particles and its relation to the mixing state and morphology of individual particles, we conducted observations of particles at an Asian outflow site in Noto Peninsula, Japan, in the spring of 2013. Absorption and scattering coefficients at 405, 532, and 781 nm and mass concentrations/mixing states of refractory BC in PM2.5 were measured using a three-wavelength photoacoustic soot spectrometer and a single-particle soot photometer (SP2), respectively, after passage through a thermodenuder (TD) maintained at 300 or 400 °C or a bypass line maintained at room temperature (25 °C). The average enhancement factor of BC light absorption due to coating was estimated by comparing absorption coefficients at 781 nm for particles that with and without passing through the TD at 300 °C and was found to be 1.22. The largest enhancements (> 1.30) were observed under high absorption coefficient periods when the air mass was long-range transported from urban areas in China. Aerosol samples were also analyzed using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer. The morphological features and mixing states of soot-containing particles of four samples collected during the high absorption events were analyzed by comparing microphotographs before and after the evaporation of beam-sensitive materials by irradiation with a high-density electron beam. The majority of the soot in all samples was found as mixed particles with sulfate-containing spherules or as clusters of such spherules. For samples showing high enhancement (> 1.30) of BC light absorption, the TEM showed that the internally mixed soot-containing particles tended to have a more spherical shape and to be thickly coated. The SP2 measurements also suggested that the proportion of thickly coated

  8. Multiple site study of recent atmospheric metal (Pb, Zn and Cu) deposition in the NW Iberian Peninsula using peat cores.

    PubMed

    Olid, Carolina; Garcia-Orellana, Jordi; Martínez-Cortizas, Antonio; Masqué, Pere; Peiteado-Varela, Eva; Sanchez-Cabeza, Joan-Albert

    2010-10-15

    In order to estimate atmospheric metal deposition in Southern Europe since the beginning of the Industrial Period (~1850 AD), concentration profiles of Pb, Zn and Cu were determined in four (210)Pb-dated peat cores from ombrotrophic bogs in Serra do Xistral (Galicia, NW Iberian Peninsula). Maximum metal concentrations varied by a factor of 1.8 for Pb and Zn (70 to 128μgg(-1) and 128 to 231μgg(-1), respectively) and 3.5 for Cu (11 to 37μgg(-1)). The cumulative metal inventories of each core varied by a factor of 3 for all analysed metals (132 to 329μgcm(-2) for Pb, 198 to 625μgcm(-2) for Zn and 22 to 69μgcm(-2) for Cu), suggesting differences in net accumulation rates among peatlands. Although results suggest that mean deposition rates vary within the studied area, the enhanced (210)Pb accumulation and the interpretation of the inventory ratios ((210)Pb/Pb, Zn/Pb and Cu/Pb) in two bogs indicated that either a record perturbation or post-depositional redistribution effects must be considered. After correction, Pb, Zn and Cu profiles showed increasing concentrations and atmospheric fluxes since the mid-XX(th) century to maximum values in the second half of the XX(th) century. For Pb, maximum fluxes were observed in 1955-1962 and ranged from 16 to 22mgm(-2)yr(-1) (mean of 18±1mgm(-2)yr(-1)), two orders of magnitude higher than in the pre-industrial period. Peaks in Pb fluxes in Serra do Xistral before the period of maximum consumption of leaded petrol in Europe (1970s-1980s) suggest the dominance of local pollutant sources in the area (i.e. coal mining and burning). More recent peaks were observed for Zn and Cu, with fluxes ranging from 32 to 52mgm(-2)yr(-1) in 1989-1996, and from 4 to 9mgm(-2)yr(-1) in 1994-2001, respectively. Our results underline the importance of multi-core studies to assess both the integrity and reliability of peat records, and the degree of homogeneity in bog accumulation. We show the usefulness of using the excess (210)Pb inventory to

  9. Analysis of aerosol scattering properties measured by a nephelometer at a coastal-rural site in the Atlantic southwest of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    López, Juan F.; Cachorro, Victoria E.; de Frutos, Angel M.

    2015-09-01

    Aerosol hemispherical scattering and the backscattering coefficients, σsp, σbsc, have been measured using a 3-wavelength (450, 550 and 700 nm) integrating nephelometer over two years (January 2006-May 2008) in the coastal area of the Gulf of Cádiz, in the southwest of the Iberian Peninsula. These coefficients have been carefully analyzed starting with the impact of corrections on the measurements of σsp: i.e., drift calibration constants do not modify the mean value in our data series. However, the selection of dry data (with RH less than 50%) modifies substantially the number of data and the resulting mean value of σsp is now 14% lower, which is compensated when the angular truncation correction is applied. The characterization and features of σsp, σbsc, and the derived parameters αsp (alpha Ångström exponent) and b (the backscatter ratio) has been analyzed, as annual, seasonal and diurnal evolution. A general statistic based on hourly data gives mean values and standard deviation of σsp (500 nm)=48±38 Mm-1 with a median of 38 Mm-1, and σbsc (500 nm)=5.6±3.8 Mm-1 with a median of 4.6 Mm-1. Thus, these values show moderate-low values but with a large range of variation considering the existing measured values over the Iberian Peninsula. The median value of σsp (500 nm) is an indicator that events of high aerosol burden are frequent presenting a substantial influence on the daily averages. The alpha Ångström exponent, αsp, derived from the pairs 450/700 nm gives a mean value 1.35±0.54 with a median of 1.47 and with the most frequent value of 1.7, thus indicating the prevalence of medium size particles but with a significant influence of fine particles. The b ratio has the same value for mean and median, 0.12±0.02, showing a decrease with increasing values of σsp. Annual and daily cycles have been also analyzed showing the complex behaviour of the optical properties at this coastal site where cold and warn periods show very different

  10. Climate and environments during Marine Isotope Stage 11 in the central Iberian Peninsula: the herpetofaunal assemblage from the Acheulean site of Áridos-1, Madrid

    NASA Astrophysics Data System (ADS)

    Blain, Hugues-Alexandre; Santonja, Manuel; Pérez-González, Alfredo; Panera, Joaquin; Rubio-Jara, Susana

    2014-06-01

    The interglacial episodes of the Quaternary Period are currently the focus of a great deal of attention within the scientific community, primarily because they can help us to understand how the climate of the current interglacial may have evolved without human intervention and to assess the impact of these climate changes on ecological systems. In the central Iberian Peninsula, the archaeological site of Áridos-1 (Arganda, Madrid), with numeric dates of 379.7 ± 45 ka obtained by AAR for the upper part of the sedimentological unit of Arganda I, in combination with the evolved state of the small mammals, has been chronologically attributed to Marine Isotope Stage (MIS) 11. Given the diversified faunal assemblages delivered by the 1976 excavations, Áridos-1 is probably one of the best terrestrial candidates for an understanding of the climatic and environmental conditions that prevailed in central Spain during the MIS 11 interglacial. In consequence, the fossil amphibians and squamate reptiles stored in the collections of the Museo Arqueológico Nacional of Madrid have been newly described and quantified in order to apply the mutual climatic range and habitat weighting methods for estimating quantitative data. The Mediterranean climate is shown to have been warmer and wetter than today in central Spain during MIS 11, with the mean annual temperature 1.7 °C higher and mean annual precipitation 223.9 mm higher than at present. The monthly climatic reconstruction shows differences in the distribution of precipitation over the course of the year, with more abundant precipitation during the winter months, at the beginning of spring and at the end of fall (from October to March) and less precipitation than today during the summer months and at the end of spring (from May to August), suggesting stronger rainfall seasonality between winter and summer than currently occurs. Such climate reconstruction is consistent with other European MIS 11 paleoclimatic records. The

  11. The Yucatan Peninsula

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This MODIS true-color image of the Yucatan Peninsula was acquired from data captured on October 6, 2001. The Peninsula is comprised of several Mexican states, including Yucatan in the north, Quintana Roo to the east, and Campeche to the west. Mexico also shares the Yucatan Peninsula with the countries of Belize and Guatamala, located to the south of these states. Phytoplankton show up as blue-green swirls off the western coast of Yucatan, in the center of the image, mixed in with sediment and other organic matter. Off the eastern coast of the Peninsula, running north and south along the right side of he image, the region's barrier reef is visible. Second only to Australia's Great Barrier Reef in size, the reef spans 180 miles from the northern tip of the Peninsula south into the Gulf of Honduras, and houses over 35 different species of reef-building corals.

  12. A paleomagnetic study of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Poblete, F.; Arriagada, C.; Roperch, P.

    2009-05-01

    In the Paleozoic, South America, South Africa and Antarctica were part of Gondwana. The Weddell Sea began to form at about 146 Ma, after rifting between the Antarctic Peninsula and southernmost South America. Much uncertainty still exists about the geometrical fit and subsequent drift history between Patagonia and Antarctica. Geophysical and geological data which describe the tectonic history are sparsely distributed and often of poor quality. During the last two years we have collected more than 1000 paleomagnetic samples from 70 sites at several localities (King George Island, Robert Island, Yankee Bay, Half Moon Island, Byers Peninsula and Snow Island) from the South Shetland Islands and Anderson Island in the northern tip of Antarctic Peninsula. Our main objective was to provide first-order constraints on latitudinal displacements and the amount of tectonic rotations as an essential test of published tectonic models. Paleomagnetic results were obtained from 50 sites. All samples from sites in volcanic and intrusive rocks have well-defined univectorial magnetizations. Unfortunately, all sites in late Paleozoic sediments have been remagnetized and the magnetizations are often unstable upon thermal demagnetization. Cretaceous and Cenozoic units display very little apparent polar wander. Results from intrusive rocks of expected Jurassic age do not confirm the expected relative rotation betwen the Antarctic Peninsula and East Antarctica. Further radiometric dating are needed to confirm the age of these units.

  13. Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Temperate and green in the summer, the Kamchatka Peninsula in northeastern Russia freezes over completely in the winter. This true-color image of the Kamchatka Peninsula was acquired on December 12, 2001, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. The peninsula is surrounded by the Sea of Okhotsk to the west and by the Bering Sea to the east. The ice and snow highlight the stunning valleys and tall peaks of the Sredinnyy Khrebet, which is the volcanic mountain range running down the center of the peninsula. The mountains along the range reach heights of over 3500 meters (11,484 feet). Many of the volcanoes are still active, and ash and volcanic rock has turned the snow a dark gray on the eastern side of the range. The light blue latticework of ridges, valleys, and alluvial fans extending from the center of the range were likely carved out by past and present glaciers and by run-off from spring snowmelt. The small island that extends off of the tip of the peninsula is Ostrov Paramushir (Paramushir Island). Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  14. Ambient levels of volatile organic compounds and criteria pollutants in the most industrialized area of central Iberian Peninsula: intercomparison with an urban site.

    PubMed

    Villanueva, Florentina; Notario, Alberto; Tapia, Araceli; Albaladejo, José; Cabañas, Beatriz; Martínez, Ernesto

    2016-01-01

    This work presents observations of volatile organic compounds (VOCs), including carbonyls, particulate matter 2.5 (PM2.5) (included in the most recent ambient air quality standards because of its harmful effect on health), PM10 and other important pollutants, CO, SO2, NOx and ozone, over the most industrialized area in the central Iberian Peninsula. Nearly two years of data obtained through a mobile laboratory are used for this purpose. Different concentration ratios and correlations were calculated to assess the effect of the anthropogenic or biogenic processes on the observed VOC levels. The diurnal profile for SO2 is different in Puertollano and it does not coincide with the maxima of the other primary pollutants such as benzene, toluene and xylenes (BTX), CO and NO. This behaviour could be attributed to the fact that SO2 mainly comes from industrial activities. However, an impact of the industry on air quality was detected not only by the results obtained for SO2, but also by the toluene/benzene, T/B, ratio (7.5). Finally, correlations between meteorological conditions and pollution distribution have been considered; also, the analysis of the back trajectories together with Spearman correlation coefficients have been carried out to understand the origin and pathway in some events with unusual high pollutant values. PMID:26508360

  15. Evaluation of hot dry rock exploration techniques in the Atlantic Coastal Plain: a test site on the Delmarva Peninsula of Maryland and Virginia

    SciTech Connect

    Not Available

    1981-04-01

    Detailed investigation of a potential Hot Dry Rock (HDR) energy extraction site in the area of Crisfield, Maryland, and Wallops Island, Virginia, (referred to as the Cris-Wall site) was carried out to evaluate HDR exploration techniques in the Atlantic Coastal Plain province. The findings favor the HDR exploration program that is outlined for locating a deep test hole in an area with presumed HDR potential (higher than normal heat flow). Six potential sites for extracting HDR energy have been identified within the Cris-Wall area. Each site is thought to have temperatures at the basement rock surface in excess of 75/sup 0/C and to be at least 1 km away from the nearest fault.

  16. Gulf of Aqaba, Sinai Peninsula

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Gulf of Aqaba separates the Sinai peninsula from Saudi Arabia in this scene of the Middle East (29.0N, 34.5E) showing the geomorphology and geology of this region including portions of Egypt, Israel, Jordon and Saudi Arabia. A small portion of the Gulf of Suez can be seen on the opposite side of the Sinai peninsula.

  17. Aniakchak Crater, Alaska Peninsula

    USGS Publications Warehouse

    Smith, Walter R.

    1925-01-01

    The discovery of a gigantic crater northwest of Aniakchak Bay (see fig. 11) closes what had been thought to be a wide gap in the extensive series of volcanoes occurring at irregular intervals for nearly 600 miles along the axial line of the Alaska Peninsula and the Aleutian Islands. In this belt there are more active and recently active volcanoes than in all the rest of North America. Exclusive of those on the west side of Cook Inlet, which, however, belong to the same group, this belt contains at least 42 active or well-preserved volcanoes and about half as many mountains suspected or reported to be volcanoes. The locations of some of these mountains and the hot springs on the Alaska Peninsula and the Aleutian Islands are shown on a map prepared by G. A. Waring. Attention has been called to these volcanoes for nearly two centuries, but a record of their activity since the discovery of Alaska is far from being complete, and an adequate description of them as a group has never been written. Owing to their recent activity or unusual scenic beauty, some of the best known of the group are Mounts Katmai, Bogoslof, and Shishaldin, but there are many other beautiful and interesting cones and craters.

  18. Anaglyph, Yucatan Peninsula, Mexico

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This anaglyph (stereoscopic view) of Mexico's Yucatan Peninsula was generated entirely from Shuttle Radar Topography Mission (SRTM) data, and shows a subtle but distinctive indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary extinction, the event 65 million years ago that marked the demise of the dinosaurs as well as the majority of life then on Earth. The crater's rim is marked by a shallow semicircular depression arcing about an offshore center point in the upper left of the picture. (The arcing depression is just above the blue line, when viewed with the naked eye.) This depression, or trough, only about 3 to 5 meters (10 - 15 feet) deep and about 5 kilometers (3 miles) wide, was likely caused by collapse of limestone caverns preferentially above the crater rim, resulting in an arcing chain of sinkholes. The limestone that covers most of the Yucatan Peninsula post-dates the impact crater. However, the crater pattern apparently controls the subsidence pattern just enough to show through.

    This anaglyph was created by deriving a shaded relief image from the SRTM data, draping it back over the SRTM elevation model, and then generating two differing perspectives, one for each eye. Illumination is from the north (top). When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. The total relief (range of elevations) across this entire image is less than 300 meters (1000 feet).

    Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM

  19. Petroleum geology of Arabian Peninsula

    SciTech Connect

    Billo, S.M.

    1982-05-01

    Petroleum activities in the Arabian Peninsula show new trends in the 1980s. Petroleum exploration is intensified and huge discoveries are anticipated. A giant Jurassic gas field along the coast of the Arabian Gulf discovered recently tops 150 tcf, the largest single reserve ever. Other giant oil fields in the area are undergoing expansion in development and productivity. Today, the Peninsula, with a total area that surpasses one million square miles, produces and exports more oil and gas and has greater reserves than any other area in the world. The excellent reservoir rocks are located in the Jurassic and Cretaceous formations between the Arabian Shield and the Tethyan Seaway. They represent porous and permeable marine cyclical beds sealed by impervious shales and anhydrites. Reservoir sedimentology was affected by 2 orogenies during late Cretaceous and Pliocene time portrayed by the Cratonic area to the southwest and the orthogeosynclinal area to the northeast. The eastern part was little deformed by these movements.

  20. Fires in Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Numerous thermal anomalies were detected on the Kamchatka Peninsula in northeastern Russia in late June and early July by the Moderate Resolution Imaging Spectroradiometer (MODIS). Some of the anomalies (red dots) were fires, but at least one was the result of ongoing volcanic activity at one of the Peninsula's numerous active volcanoes. The erupting volcano, called Sheveluch, can be seen most clearly in the image from July 8, 2002. It is located in the upper right quadrant of the image, and appears as a grayish circular patch amid the surrounding green vegetation. In its center is a red dot indicating that MODIS detected a thermal signature coming from the restless volcano. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  1. Sunglint and Florida Peninsula, USA

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Gulf coast and the Florida peninsula (30.0N, 81.5W) seen in sunglint. The lakes of central Florida are highlighted in reflected light in this scene. The view extends up along the Georgia and South Carolina Coast and clouds cast shadows in the sunglint. The sunglint off the east coast also highlights shears in the Atlantic related to the Gulf Stream. To the south, Andros Island and the Grand Bahama Bank are visible.

  2. 77 FR 53168 - Olympic Peninsula Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-31

    ... Forest Service Olympic Peninsula Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Olympic Peninsula Resource Advisory Committee will meet in Olympia, WA. The...: The following business will be conducted: The Olympic Peninsula Resource Advisory Committee...

  3. [The Arabian Peninsula: demographic surprises].

    PubMed

    Courbage, Y

    1994-01-01

    A review of current demographic trends in the countries of the Arabian Peninsula is presented, based on a number of recent surveys of child health carried out in the early 1990s. Considerable diversity is noted among the countries examined in both demographic trends and levels of socioeconomic development. However, the status of women appears to be more advanced throughout the region than in most other Muslim countries, which could indicate that a reduction in fertility is probable. The author notes a general decline in oil revenues, accompanied by a decline in fertility, throughout the region.

  4. Zoonoses in the Arabian Peninsula

    PubMed Central

    Wernery, Ulrich

    2014-01-01

    The human population is rising and will soon reach 9 billion people. In parallel, the demand for animal protein is increasing and with it is the threat of zoonotic diseases. We must therefore be on our guard. The close association of people with animals promotes the opportunity for zoonotic infections and real danger may arise when animals are imported with no health background. Therefore, it is essential to implement strict import controls, and establish efficient quarantine facilities. Many viral, bacterial, and zoonotic diseases have been diagnosed on the Arabian Peninsula, either by isolating the pathogens or through serological surveys. Most of them are briefly discussed in this paper. PMID:25491209

  5. The Spatial Coherence of Interannual Temperature Variations in the Antarctic Peninsula

    NASA Technical Reports Server (NTRS)

    King, John C.; Comiso, Josefino C.; Koblinsky, Chester J. (Technical Monitor)

    2002-01-01

    Over 50 years of observations from climate stations on the west coast of the Antarctic Peninsula show that this is a region of extreme interannual variability in near-surface temperatures. The region has also experienced more rapid warming than any other part of the Southern Hemisphere. In this paper we use a new dataset of satellite-derived surface temperatures to define the extent of the region of extreme variability more clearly than was possible using the sparse station data. The region in which satellite surface temperatures correlate strongly with west Peninsula station temperatures is found to be quite small and is largely confined to the seas just west of the Peninsula, with a northward and eastward extension into the Scotia Sea and a southward extension onto the western slopes of Palmer Land. Correlation of Peninsula surface temperatures with surface temperatures over the rest of continental Antarctica is poor confirming that the west Peninsula is in a different climate regime. The analysis has been used to identify sites where ice core proxy records might be representative of variations on the west coast of the Peninsula. Of the five existing core sites examined, only one is likely to provide a representative record for the west coast.

  6. Iberian Peninsula and Balearic Island Bathynellacea (Crustacea, Syncarida) database

    PubMed Central

    Camacho, Ana I.; Dorda, Beatriz A.; Rey, Isabel

    2014-01-01

    Abstract This is the first published database of Bathynellacea. It includes all data of bathynellids (Crustacea, Bathynellacea) collected in the last 64 years (1949 to 2013) on the Iberian Peninsula and Balearic Island. The samples come from groundwater (caves, springs, wells and hyporrheic habitat associated rivers) from both sampling campaigns and occasional sampling conducted throughout the Iberian Peninsula and Balearic Islands. The dataset lists occurrence data of bathynellids distribution, sampling sites (with localities, county and geographic coordinates), taxonomic information (from family to species level) and sampling sources (collector and sampling dates) for all records. The descriptions of new species and species identifications have been carried out by an expert taxonomist (AIC) with 25 years experience in the bathynellids studies (see references). Many of the sampling sites are type localities of endemic species from Iberian Peninsula. The dataset includes 409 samples record corresponding to two families, 12 genera and 58 species, 42 of them formally described plus 16 taxa unpublished and 47 samples in study. All species known from the study area are included, which nearly sum up a quarter of species of Bathynellacea known in the world (250 species). PMID:24693212

  7. Heavy Metal Contamination in the Taimyr Peninsula, Siberian Arctic

    SciTech Connect

    Allen-Gil, Susan M.; Ford, Jesse; Lasorsa, Brenda K.; Monetti, Matthew; Vlasova, Tamara; Landers, Dixon H.

    2003-01-01

    The Taimyr Peninsula is directly north of the world's largest heavy metal smelting complex (Norilsk, Russia). Despite this proximity, there has been little research to examine the extent of contamination of the Taimyr Peninsula. We analyzed heavy metal concentrations in lichen (Cetraria cucullata), moss (Hylocomium splendens), soils, lake sediment, freshwater fish (Salvelinus alpinus, Lota lota, and Coregonus spp.) and collared lemming (Dicrostonyx torquatus) from 13 sites between 30 and 300 km from Norilsk. Element concentrations were low in both C. cucullata and H. splendens, although concentrations of Al, Fe, Cu, Ni, and Pb were significantly higher than those in Arctic Alaska, probably due to natural differences in the geochemical environments. Inorganic surface soils had significantly higher concentrations of Cd, Zn, Pb, and Mg than inorganic soils at depth, although a lake sediment core from the eastern Taimyr Peninsula indicated no recent enrichment by atmospherically transported elements. Tissue concentrations of heavy metals in fish and lemming were not elevated relative to other Arctic sites. Our results show that the impact of the Norilsk smelting complex is primarily localized rather than regional, and does not extend northward beyond 100 km.

  8. Iberian Peninsula and Balearic Island Bathynellacea (Crustacea, Syncarida) database.

    PubMed

    Camacho, Ana I; Dorda, Beatriz A; Rey, Isabel

    2014-01-01

    This is the first published database of Bathynellacea. It includes all data of bathynellids (Crustacea, Bathynellacea) collected in the last 64 years (1949 to 2013) on the Iberian Peninsula and Balearic Island. The samples come from groundwater (caves, springs, wells and hyporrheic habitat associated rivers) from both sampling campaigns and occasional sampling conducted throughout the Iberian Peninsula and Balearic Islands. The dataset lists occurrence data of bathynellids distribution, sampling sites (with localities, county and geographic coordinates), taxonomic information (from family to species level) and sampling sources (collector and sampling dates) for all records. The descriptions of new species and species identifications have been carried out by an expert taxonomist (AIC) with 25 years experience in the bathynellids studies (see references). Many of the sampling sites are type localities of endemic species from Iberian Peninsula. The dataset includes 409 samples record corresponding to two families, 12 genera and 58 species, 42 of them formally described plus 16 taxa unpublished and 47 samples in study. All species known from the study area are included, which nearly sum up a quarter of species of Bathynellacea known in the world (250 species). PMID:24693212

  9. Increasing waterfowl nesting success on islands and peninsulas

    USGS Publications Warehouse

    Lokemoen, J.T.

    1993-01-01

    Waterfowl that nest in uplands in the prairie pothole region have had low recruitment rates in recent decades, primarily because of predation. The loss of breeding waterfowl and their progeny has generated interest in management techniques that safeguard incubating hens and their eggs. Developing islands and peninsulas for nesting waterfowl has potential because these sites are naturally attractive to breeding ducks and geese. In fact, dense nesting colonies of ducks developed on some islands when successful females and a portion of their female progeny returned in subsequent years.Managers have successfully duplicated the beneficial attributes of islands by developing various nesting habitats that are protected by water barriers. This chapter addresses the management of existing islands, the creation of new islands, and the modification of peninsulas into islands to increase nesting success in waterfowl.

  10. Korean peninsula: A northeast Asian security concern. Individual study project

    SciTech Connect

    Blackburn, N.G.

    1993-03-22

    North and South Korea have not responded to the New World Order-that Communism is dead and the Cold War Era is over. When the Berlin Wall collapsed and Germany became one nation, Korea emerged as the only divided country remaining in the world. Today, the Korean Peninsula remains divided by ideology, mutual mistrust of national leadership, the 155-mile DMZ, US military presence, conflicting approaches to national reunification, and the North Korean nuclear issue. Thus, the traditional Cold War animosities and political, economic, military paradigms remain entrenched in a divided Korean peninsula. The US Intelligence Community has identified an extensive nuclear center at Yongbyon, 50 miles north of Pyongyang, North Korea's capital, which appears to be a nuclear reactor and reprocessing site. The threat of a nuclear-armed North Korea is a serious regional security concern that will not be taken lightly by such countries as Japan, China, Russia, South Korea, and the United States.

  11. New evidence of early Neanderthal disappearance in the Iberian Peninsula.

    PubMed

    Galván, Bertila; Hernández, Cristo M; Mallol, Carolina; Mercier, Norbert; Sistiaga, Ainara; Soler, Vicente

    2014-10-01

    The timing of the end of the Middle Palaeolithic and the disappearance of Neanderthals continue to be strongly debated. Current chronometric evidence from different European sites pushes the end of the Middle Palaeolithic throughout the continent back to around 42 thousand years ago (ka). This has called into question some of the dates from the Iberian Peninsula, previously considered as one of the last refuge zones of the Neanderthals. Evidence of Neanderthal occupation in Iberia after 42 ka is now very scarce and open to debate on chronological and technological grounds. Here we report thermoluminescence (TL) and optically stimulated luminescence (OSL) dates from El Salt, a Middle Palaeolithic site in Alicante, Spain, the archaeological sequence of which shows a transition from recurrent to sporadic human occupation culminating in the abandonment of the site. The new dates place this sequence within MIS 3, between ca. 60 and 45 ka. An abrupt sedimentary change towards the top of the sequence suggests a strong aridification episode coinciding with the last Neanderthal occupation of the site. These results are in agreement with current chronometric data from other sites in the Iberian Peninsula and point towards possible breakdown and disappearance of the Neanderthal local population around the time of the Heinrich 5 event. Iberian sites with recent dates (<40 ka) attributed to the Middle Palaeolithic should be revised in the light of these data.

  12. New evidence of early Neanderthal disappearance in the Iberian Peninsula.

    PubMed

    Galván, Bertila; Hernández, Cristo M; Mallol, Carolina; Mercier, Norbert; Sistiaga, Ainara; Soler, Vicente

    2014-10-01

    The timing of the end of the Middle Palaeolithic and the disappearance of Neanderthals continue to be strongly debated. Current chronometric evidence from different European sites pushes the end of the Middle Palaeolithic throughout the continent back to around 42 thousand years ago (ka). This has called into question some of the dates from the Iberian Peninsula, previously considered as one of the last refuge zones of the Neanderthals. Evidence of Neanderthal occupation in Iberia after 42 ka is now very scarce and open to debate on chronological and technological grounds. Here we report thermoluminescence (TL) and optically stimulated luminescence (OSL) dates from El Salt, a Middle Palaeolithic site in Alicante, Spain, the archaeological sequence of which shows a transition from recurrent to sporadic human occupation culminating in the abandonment of the site. The new dates place this sequence within MIS 3, between ca. 60 and 45 ka. An abrupt sedimentary change towards the top of the sequence suggests a strong aridification episode coinciding with the last Neanderthal occupation of the site. These results are in agreement with current chronometric data from other sites in the Iberian Peninsula and point towards possible breakdown and disappearance of the Neanderthal local population around the time of the Heinrich 5 event. Iberian sites with recent dates (<40 ka) attributed to the Middle Palaeolithic should be revised in the light of these data. PMID:25016565

  13. Geyser Valley on the Kamchatka Peninsula

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On June 2, a devastating mudslide in the world-renowned Geyser Valley on the Kamchatka Peninsula virtually obliterated the natural wonder, forcing the emergency evacuation of visitors and national park personnel. The site, which is the Kamchatka Peninsula's main tourist attraction, consists of some 200 thermal pools created by the area's intense volcanic activity, including about 90 geysers covering an area of four square kilometers (2.5 square miles). It is one of only five sites in the world where the impressive eruptions of steam and boiling-hot water can be found. According to witnesses, a powerful mudslide 1.5 kilometers (one mile) long and 200 meters (600 feet) wide buried more than two-thirds of the valley beneath tens of meters of snow, dirt, trees and boulders (right image), and created a temporary lake submerging more geysers.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is

  14. Arabian peninsula: zone of ferment

    SciTech Connect

    Stookey, R.W.

    1984-01-01

    The Arabian Peninsula is an area which must be approached in terms of its own values and traditions. The different states, however, present difficulties for even the most well-informed policymaker because the region is not homogeneous. Some of the states are tenuous congeries of tribal and sectarian communities that do not necessarily share the aims of the ruling group. The authors of these six essays consider (1) the economic position of the states, (2) how oil exports affect the economies of the exporting states, (3) how traditional tribal and religious societies react to change, (4) whether their social values are conducive to modernization, and (5) what factors lead to the development of dissent, and how they affect the expression of dissent. Separate abstracts were prepared for two of the essays selected for the Energy Data Base (EDB) and Energy Abstracts for Policy Analysis (EAPA). 23 tables.

  15. Environmental geophysics, offshore Bush River Peninsula, Aberdeen Proving Ground, Maryland

    SciTech Connect

    Miller, S.F.; Kuecher, G.J.; Davies, B.E.

    1995-11-01

    Geophysical studies in shallow waters adjacent to the Bush River Peninsula, Edgewood Area of Aberdeen Proving Ground, Maryland, have delineated the extent of waste disposal sites and established a hydrogeologic framework, which may control contaminant transport offshore. These studies indicate that during the Pleistocene Epoch, alternating stands of high and low sea levels resulted in a complex pattern of shallow channel-fill deposits around the Bush River Peninsula. Ground-penetrating radar studies reveal paleochannels greater than 50 ft deep. Some of the paleochannels are also imaged with marine seismic reflection. Conductivity highs measured with the EM-31 are also indicative of paleochannels. This paleochannel depositional system is environmentally significant because it may control the shallow groundwater flow regime beneath the peninsula. Magnetic, conductivity, and side-scan sonar anomalies outline anthropogenic anomalies in the study area. On the basis of geophysical data, underwater anthropogenic materials do exist in some isolated areas, but large-scale offshore dumping has not occurred in the area studied.

  16. Tropical Depression Alex hits Yucatan Peninsula

    NASA Video Gallery

    NASA's TRMM spacecraft observed this view of Tropical Depression Alex on June 27, 2010 at 2214 UTC (6:14 PM EST). Tropical depression Alex was near the western coast of Mexico's Yucatan Peninsula. ...

  17. QUANTITATIVE PALEOCLIMATE RECONSTRUCTIONS FROM THE MELVILLE PENINSULA, NUNAVUT, CANADA

    NASA Astrophysics Data System (ADS)

    Adams, J. K.; Finkelstein, S. A.

    2009-12-01

    Arctic regions have heightened sensitivity to climatic changes, however regional scale differences exist in the magnitude and timing of response to climatic changes. Modern and paleoclimate data indicate spatial variability in Arctic climates due to local variations in topography, sea ice persistence, or proximity to the coast. Melville Peninsula in the east-central Canadian Arctic is in a modern transitional climate area, with a relatively continental climate to the west and a more maritime climate to the east. Thus, shifting climates may particularly influence the region, and may have affected Thule migration during the past millennium. The presence of Thule archaeological sites and a transitional climate make the Melville Peninsula an area of high importance for paleoclimate reconstructions. Lake sediment cores from two adjacent lakes in the Sarcpa Lake region in the interior Melville Peninsula (68°33’N and 88°17’W, 220 m a.s.l.) were analyzed for diatom assemblages. Diatoms (microscopic algae) were well preserved in these cores and thus, could be used to track paleoclimatic changes. Unofficially named SP02 and SP04, the lakes are 3 and 2.5 ha, respectively. Chronologies were constructed using 210Pb activity and AMS radiocarbon dates. All dates are presented as calendar years before AD 1950. Diatoms appear in SP02 5,900 yrs BP; coupled with high magnetic susceptibility and lower LOI550 in sediment older than 5,900 yrs BP, the appearance of diatoms at this time confirms earlier suggestions of a persistent ice cap on the Peninsula until 6,500 yrs BP. Diatom assemblages are dominated by Fragilarioid species, particularly Staurosira construens var. venter and Staurosirella pinnata. Peak diatom concentration and LOI550 between 4,200 yrs BP and 2,900 yrs BP may indicate the Holocene Thermal Maximum (HTM) on Melville Peninsula. Timing of the HTM on the Peninsula is similar to that from the Baffin Island region to the east. High ratios of Staurosirella pinnata

  18. Shaded Relief, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This topographic image shows the western side of the volcanically active Kamchatka Peninsula, Russia. The data are from the first C-band mapping swath of the Shuttle Radar Topography Mission (SRTM). On the left side are four rivers, which flow northwest to the Sea of Okhotsk. These rivers are, from the south to north, Tigil, Amanina, Voyampolka, and Zhilovaya. The broad, flat floodplains of the rivers are shown in blue. These rivers are important spawning grounds for salmon. In the right side of the image is the Sredinnyy Khrebet, the volcanic mountain range that makes up the 3spine2 of the peninsula. The cluster of hills to the lower right is a field of small dormant volcanoes. High resolution SRTM topographic data will be used by geologists to study how volcanoes form and understand the hazards posed by future eruptions.

    This shaded relief image was generated using topographic data from the Shuttle Radar Topography Mission. A computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. On flatter surfaces, the pattern of light and shadows can reveal subtle features in the terrain. Colors show the elevation as measured by SRTM. Colors range from blue at the lowest elevations to white at the highest elevations. This image contains about 2300 meters (7500 feet) of total relief. Shaded relief maps are commonly used in applications such as geologic mapping and land use planning.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and

  19. Perspective View, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This perspective view shows the western side of the volcanically active Kamchatka Peninsula, Russia. The data are from the first C-band mapping swath of the Shuttle Radar Topography Mission (SRTM). In the foreground is the broad, flat floodplain of the Amanina River, shown in blue. In background of the image is the Sredinnyy Khrebet, the volcanic mountain range that makes up the 3spine2 of the peninsula. The cluster of hills in the upper right is a field of small dormant volcanoes. High resolution SRTM topographic data will be used by geologists to study how volcanoes form and understand the hazards posed by future eruptions.

    This shaded relief perspective view was generated using topographic data from the Shuttle Radar Topography Mission. A computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. On flatter surfaces, the pattern of light and shadows can reveal subtle features in the terrain. Colors show the elevation as measured by SRTM. Colors range from blue at the lowest elevations to white at the highest elevations. This image contains about 2300 meters (7500 feet) of total relief. To emphasize subtle differences in topography, the relief is exaggerated by a factor of 5.

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

  20. Sredinnyy Khrebet, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Kamchatka Peninsula in eastern Russia is shown in this scene created from a preliminary elevation model derived from the first data collected during the Shuttle Radar Topography Mission (SRTM) on February 12, 2000. Sredinnyy Khrebet, the mountain range that makes up the spine of the peninsula, is a chain of active volcanic peaks. Pleistocene and recent glaciers have carved the broad valleys and jagged ridges that are common here. The relative youth of the volcanism is revealed by the topography as infilling and smoothing of the otherwise rugged terrain by lava, ash, and pyroclastic flows, particularly surrounding the high peaks in the south central part of the image. Elevations here range from near sea level up to 2,618 meters (8,590 feet). Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow, red, and magenta, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space

  1. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary s

  2. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary sedimentary and volcanic rocks and Quaternary deposits.

  3. Geodiversity assessment of the Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Torab, Magdy; Farghaly, Enas

    2015-04-01

    The Sinai Peninsula is a triangular plateau lies in NE corner of Egypt, its head in the south at Ras Mohammed and its other sides between the Gulf of Aqaba and Gulf of Suez and the triangle base on the Mediterranean Sea. Sinai Peninsula is the most attractive region from the geological, geomorphological and environmental stand points of view because it displays a variety of simple and complex structural and landforms, (Abu Al-Izz,1971). In general, Sinai Peninsula reflects all geologic column of Egypt. Geomorphologically, Sinai Peninsula comprises many geomorphologic units such as mountains blocks, cliffs, isolated hills, wadies, hogbacks, questas, sand ridges, muddy and marshy lands, lakes and shorelines. This paper aims to define and measure geodiversity assessment index of the Sinai Peninsula as the quantitative variety of geological, topographical, geomorphological, hydrological and soil features. Some geodiversity indices maps for the above features produced for Sinai Peninsula were based on the methodology presented by (Pereira et al, 2012), it depends upon calculate of some geodiversity elements for overlay grid of the study area, which divided topographic, geological maps of the Sinai Peninsula with scale 1:500000 and satellite image (landsat 8, 27th October 2014, 12 bands, 30m). It divided into 743 squares (10x10 km), and some partial geodiversity indices such as geological, topographical, geomorphological, hydrological and soil indices were calculated by counting the number of each element inside each square, then the overall geodiversity index map produced by calculate the total number of all indices inside each square, the geodiversity index map were classified into some gradual categories by using isolines: very low, low, medium, high and very high.

  4. Shiveluch Volcano, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2001-01-01

    On the night of June 4, 2001, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) captured this thermal image of the erupting Shiveluch volcano. Located on Russia's Kamchatka Peninsula, Shiveluch rises to an altitude of 2,447 meters (8,028 feet). The active lava dome complex is seen as a bright (hot) area on the summit of the volcano. To the southwest, a second hot area is either a debris avalanche or hot ash deposit. Trailing to the west is a 25-kilometer (15-mile) ash plume, seen as a cold 'cloud' streaming from the summit. At least 60 large eruptions have occurred here during the last 10,000 years; the largest historical eruptions were in 1854 and 1964.

    Because Kamchatka is located along the major aircraft routes between North America/Europe and Asia, this area is constantly monitored for potential ash hazards to aircraft. The area is part of the 'Ring of Fire,' a string of volcanoes that encircles the Pacific Ocean.

    The lower image is the same as the upper, except it has been color-coded: red is hot, light greens to dark green are progressively colder, and gray/black are the coldest areas.

    The image is located at 56.7 degrees north latitude, 161.3 degrees east longitude.

    ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

  5. The history of Antarctic Peninsula glaciation

    USGS Publications Warehouse

    Barker, Peter F.

    2007-01-01

    As Co-Chief Scientist on DSDP Leg 35 in 1974, Cam Craddock (1930-2006) produced the first useful information on Cenozoic Antarctic Peninsula glaciation - an early middle Miocene (15-17 Ma) apparent glacial onset. Subsequent work, onshore and offshore, has greatly extended our knowledge but that early conclusion stands today. Cenozoic Antarctic Peninsula palaeoclimate as presently known is broadly consistent with global palaeoclimate proxies. Initial glacial onset was within the Eocene-Oligocene boundary interval (although earlier, short-lived glaciations have been proposed, from indirect measurements) and the peninsula probably became deglaciated in the earliest Miocene (ca. 24 Ma). The renewed middle Miocene glaciation probably continued to the present and, for the last 9 Myr at least, has persisted through glacial (orbital) cycles, with grounded ice advance to the shelf edge during maxima. Although orbital cyclicity affected earlier AP palaeoclimate also, the level of glaciation through a complete cycle is uncertain.

  6. Antarctic Peninsula Tidewater Glacier Dynamics

    NASA Astrophysics Data System (ADS)

    Pettit, E. C.; Scambos, T. A.; Haran, T. M.; Wellner, J. S.; Domack, E. W.; Vernet, M.

    2015-12-01

    The northern Antarctic Peninsula (nAP, north of 66°S) is a north-south trending mountain range extending transverse across the prevailing westerly winds of the Southern Ocean resulting in an extreme west-to-east precipitation gradient. Snowfall on the west side of the AP is one to two orders of magnitude higher than the east side. This gradient drives short, steep, fast-flowing glaciers into narrow fjords on the west side, while longer lower-sloping glaciers flow down the east side into broader fjord valleys. This pattern in ice dynamics affects ice-ocean interaction on timescales of decades to centuries, and shapes the subglacial topography and submarine bathymetry on timescales of glacial cycles. In our study, we calculate ice flux for the western and eastern nAP using a drainage model that incorporates the modern ice surface topography, the RACMO-2 precipitation estimate, and recent estimates of ice thinning. Our results, coupled with observed rates of ice velocity from InSAR (I. Joughin, personal communication) and Landsat 8 -derived flow rates (this study), provide an estimate of ice thickness and fjord depth in grounded-ice areas for the largest outlet glaciers. East-side glaciers either still terminate in or have recently terminated in ice shelves. Sedimentary evidence from the inner fjords of the western glaciers indicates they had ice shelves during LIA time, and may still have transient floating ice tongues (tabular berg calvings are observed). Although direct oceanographic evidence is limited, the high accumulation rate and rapid ice flux implies cold basal ice for the western nAP glaciers and therefore weak subglacial discharge relative to eastern nAP glaciers and or other tidewater fjord systems such as in Alaska. Finally, despite lower accumulation rates on the east side, the large elongate drainage basins result in a greater ice flux funneled through fewer deeper glaciers. Due to the relation between ice flux and erosion, these east-side glaciers

  7. Mitochondrial DNA structure in the Arabian Peninsula

    PubMed Central

    2008-01-01

    Background Two potential migratory routes followed by modern humans to colonize Eurasia from Africa have been proposed. These are the two natural passageways that connect both continents: the northern route through the Sinai Peninsula and the southern route across the Bab al Mandab strait. Recent archaeological and genetic evidence have favored a unique southern coastal route. Under this scenario, the study of the population genetic structure of the Arabian Peninsula, the first step out of Africa, to search for primary genetic links between Africa and Eurasia, is crucial. The haploid and maternally inherited mitochondrial DNA (mtDNA) molecule has been the most used genetic marker to identify and to relate lineages with clear geographic origins, as the African Ls and the Eurasian M and N that have a common root with the Africans L3. Results To assess the role of the Arabian Peninsula in the southern route, we genetically analyzed 553 Saudi Arabs using partial (546) and complete mtDNA (7) sequencing, and compared the lineages obtained with those present in Africa, the Near East, central, east and southeast Asia and Australasia. The results showed that the Arabian Peninsula has received substantial gene flow from Africa (20%), detected by the presence of L, M1 and U6 lineages; that an 18% of the Arabian Peninsula lineages have a clear eastern provenance, mainly represented by U lineages; but also by Indian M lineages and rare M links with Central Asia, Indonesia and even Australia. However, the bulk (62%) of the Arabian lineages has a Northern source. Conclusion Although there is evidence of Neolithic and more recent expansions in the Arabian Peninsula, mainly detected by (preHV)1 and J1b lineages, the lack of primitive autochthonous M and N sequences, suggests that this area has been more a receptor of human migrations, including historic ones, from Africa, India, Indonesia and even Australia, than a demographic expansion center along the proposed southern coastal

  8. 76 FR 27003 - Olympic Peninsula Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Olympic Peninsula Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Olympic Peninsula Resource Advisory Committee will meet in...

  9. 27 CFR 9.40 - Leelanau Peninsula.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.40 Leelanau Peninsula. (a) Name. The name of the viticultural area described in this section is “Leelanau... viticultural area are four U.S.G.S. maps. They are entitled: (1) “Empire Quadrangle, Michigan,” 15...

  10. 27 CFR 9.40 - Leelanau Peninsula.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.40 Leelanau Peninsula. (a) Name. The name of the viticultural area described in this section is “Leelanau... viticultural area are four U.S.G.S. maps. They are entitled: (1) “Empire Quadrangle, Michigan,” 15...

  11. 27 CFR 9.40 - Leelanau Peninsula.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.40 Leelanau Peninsula. (a) Name. The name of the viticultural area described in this section is “Leelanau... viticultural area are four U.S.G.S. maps. They are entitled: (1) “Empire Quadrangle, Michigan,” 15...

  12. 27 CFR 9.40 - Leelanau Peninsula.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.40 Leelanau Peninsula. (a) Name. The name of the viticultural area described in this section is “Leelanau... viticultural area are four U.S.G.S. maps. They are entitled: (1) “Empire Quadrangle, Michigan,” 15...

  13. 27 CFR 9.40 - Leelanau Peninsula.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.40 Leelanau Peninsula. (a) Name. The name of the viticultural area described in this section is “Leelanau... viticultural area are four U.S.G.S. maps. They are entitled: (1) “Empire Quadrangle, Michigan,” 15...

  14. Orthobunyavirus Antibodies in Humans, Yucatan Peninsula, Mexico

    PubMed Central

    Saiyasombat, Rungrat; Talavera-Aguilar, Lourdes G.; Garcia-Rejon, Julian E.; Farfan-Ale, Jose A.; Machain-Williams, Carlos; Loroño-Pino, Maria A.

    2012-01-01

    We performed a serologic investigation to determine whether orthobunyaviruses commonly infect humans in the Yucatan Peninsula of Mexico. Orthobunyavirus-specific antibodies were detected by plaque reduction neutralization test in 146 (18%) of 823 persons tested. Further studies are needed to determine health risks for humans from this potentially deadly group of viruses. PMID:23017592

  15. The Peninsula Academies. Third Yearly Interim Report.

    ERIC Educational Resources Information Center

    Reynolds, Dorothy F.

    The performance of the Peninsula Academies of Electronics and Computer Technology was assessed for the program's third year of operation in two host schools in the Sequoia Union High School District. Data were collected for approximately 190 Academy students and for a comparison group of non-Academy students. Academies students missed fewer days…

  16. Paleogene sequence on the Alaska Peninsula

    SciTech Connect

    Detterman, R.L.

    1985-04-01

    Paleogene strata are exposed nearly the entire length of the Alaska Peninsula. They include continental and marine volcaniclastic rocks and a thick volcanic sequence. The strata are divided into the Tolstoi, Stepovak, Meshik, and Belkofski (in part) Formations in the southern part of the peninsula, and into the nonmarine clastic West Foreland Formation and the Hemlock Conglomerate in the northern part. The Tolstoi Formation (Paleocene and Eocene), 670-1380 m thick, consists mainly of continental quartz- and chert-rich sandstone and conglomerate, siltstone, and coal. Volcanic clasts and tuffaceous detritus increase in abundance upward. Neritic strata are present as interbeds in the type area. The formation overlies, with a major unconformity, strata ranging in age from Late Jurassic to Late Cretaceous. Partly coeval strata at the north end of the peninsula (West Foreland Formation) are mainly volcanic sandstone and conglomerate. The Stepovak Formation, 1800-2000 m thick, represents two contrasting depositional environments - a lower dark siltstone and sandstone turbidite, about 975 m thick, and a shallow neritic sandstone and siltstone, rich in volcanic material, about 1000 m thick. Locally, the upper part is deltaic sandstone, siltstone, and coal. An abundant metafauna of Eocene and Oligocene age is found in the neritic deposits. A thick coeval volcanic unit, the Meshik Formation, is present in the central part of the peninsula. Andesitic to basaltic lava, breccia, tuff, and lahars, as much as 1500 m thick, have been K-Ar dated at 27-38 m.y. Similar rocks with interbedded sediment at the end of the peninsula are included with the Belkofski Formation.

  17. Helium and mercury in the central Seward Peninsula

    SciTech Connect

    Wescott, E.; Ruscetta, C.A.; Foley, D.

    1981-05-01

    The central Seward Peninsula, Alaska, has one Known Geothermal Resource Area (KGRA) at Pilgrim Springs, and has recent volcanic flows, fault systems, topographic and tectonic features which can be explained by a rift model. As part of a geothermal reconnaissance of the area we used helium and mercury concentrations in soil as indicators of geothermal resources. The largest helium concentrations were found in the vicinity of the Pilgrims Springs KGRA, and indicate prime drilling sites. Five profile lines were run across the suspected rift system. Significant helium anomalies were found on several of the traverses, where future exploration might be concentrated. Mercury values showed a great range of variability on the traverses, and seem unreliable as geothermal indicators except in the vicinity of the Pilgrim Springs. Permafrost at the surface resulting in variations in sampling depth may contribute to the mercury variations.

  18. Statistical Analysis of Iberian Peninsula Megaliths Orientations

    NASA Astrophysics Data System (ADS)

    González-García, A. C.

    2009-08-01

    Megalithic monuments have been intensively surveyed and studied from the archaeoastronomical point of view in the past decades. We have orientation measurements for over one thousand megalithic burial monuments in the Iberian Peninsula, from several different periods. These data, however, lack a sound understanding. A way to classify and start to understand such orientations is by means of statistical analysis of the data. A first attempt is done with simple statistical variables and a mere comparison between the different areas. In order to minimise the subjectivity in the process a further more complicated analysis is performed. Some interesting results linking the orientation and the geographical location will be presented. Finally I will present some models comparing the orientation of the megaliths in the Iberian Peninsula with the rising of the sun and the moon at several times of the year.

  19. A Late Holocene Slip Rate Of The North Anatolian Fault, Hersek Peninsula, Izmit Bay, Turkey

    NASA Astrophysics Data System (ADS)

    Kozaci, O.; Altunel, E.; Clahan, K.; Yonlu, O.; Sundermann, S. T.; Lettis, W. R.; Turner, J.; Altekruse, J.; Gumus, I.; Lindvall, S. C.

    2010-12-01

    The Hersek Peninsula has been a strategic site for at least the last two millennia as a result of its location. It extends into Izmit Bay and creates a shortcut for the historical Bagdad Road, an important section of the spice route, between Istanbul (Constantinople) and Iznik (Nicaea). It also controls the entrance of Izmit Bay to Izmit (Nicomedia). Civilizations have been investing in this location by building harbors, fortifications, baths, roads, bridges, aqueducts, and temples. The remnants of these historical structures record evidence for past destruction of both anthropogenic and tectonic origin. From an active tectonics point of view, the Hersek Peninsula is a key locality for understanding seismic hazard in the Marmara Region. It is the last place that the North Anatolian fault can be studied on land before it enters the Marmara Sea and it has experienced strong ground shaking most recently during the M7.4 Izmit earthquake in 1999. Paleoseismic trenching as well as archeoseismologic investigations were recently performed on the Hersek Peninsula for regional and site specific seismic hazard characterization. Our paleoseismic trenches north of the Hersek Lagoon provided fault exposures confirming the location of the North Anatolian fault on the peninsula. Detailed mapping of a 6th century A.D. Byzantine aqueduct offset 14 ± 1 meters along the projection of this fault trace revealed a minimum late Holocene slip rate of 13.6 +1/-3.5 mm yr-1. Rapid fan deposition and subsidence on the delta plain across the Hersek Peninsula has resulted in the relatively recent deposition of several meters of relatively young alluvium and nearshore tidal deposits. Nearly 2 km of trench exposures revealed these deposits were continuous and contain only minor evidence of ground shaking in the form of secondary liquefaction deposits and ground fractures. The lack of primary ground surface rupture evidence in these approximately 300-year-old sediments strongly suggests that the

  20. [[Characterization of the potential geographical distribution area of parrot species in Yucatan Peninsula, Mexico].

    PubMed

    Plasencia Vázquez, Alexis Herminio; Escalona Segura, Griselda

    2014-12-01

    Psittacidae family is one of the most endangered groups in Mexico, since many of their habitats are disappearing. In this research, we characterized the land cover of the potential geographical distribu- tion area of eight extant parrot species within the Yucatan Peninsula. We used the Maximum Entropy algorithm (MaxEnt) and species historical records. To externally validate the models, we used presence and absence records from field observations (2010-2012). To characterize the distribution area, we used the vegetation and land use maps of INEGI Series IV (2007-2010). The models showed a good performance, according to the values of the area under the curve (AUC), which ranged between 0.88-0.95 with the training data and between 0.82-0.91 with test data. We located most of the species in sites where the models predicted their presence. In the Peninsula, over 76% of the parrots' potential geographical distribution area is forested, except for Amazona oratrix. The subhumid tropical forest is the best represented, and the livestock for land use. The most affected species within the Peninsula are: Amazona farinosa and A. oratrix. The Calakmul Biosphere Reserve is the most important area for parrots' protection in the Peninsula. Knowing the characteristics of distribution areas is an essential part in the establishment of parrots' conservation strategies.

  1. Tectonic map of the Arabian Peninsula

    USGS Publications Warehouse

    Brown, Glen F.

    1972-01-01

    This tectonic map of the Arabian peninsula, prepared for the Audi Arabian Ministry of Petroleum and Mineral Resource, is the first of a series of peninsular maps that attempt to show regional features. Much recent information resulting from detailed geologic mapping notably within the Arabian craton, from geophysical surveys, both airborne and oceanographic in adjacent seas, from deep exploratory drilling, and from photography from the Gemini and Apollo space programs, has been used in the tectonic evaluation.

  2. Qatar Peninsula, United Arab Emirates, Persian Gulf

    NASA Technical Reports Server (NTRS)

    1983-01-01

    In this view of the Qatar Peninsula, United Arab Emirates, Persian Gulf, (25.0N, 51.0E) a large oil spill, seen as a large dark toned mass in the water covers much of the surface of the western Persian Gulf. Qatar is one of several of the oil rich United Arab Emirate states. Oil spills and oil pollution of the environment are common occurrances associated with oil tanker loading operations.

  3. Ground-water conditions and quality in the western part of Kenai Peninsula, southcentral Alaska

    USGS Publications Warehouse

    Glass, R.L.

    1996-01-01

    The western part of Kenai Peninsula in southcentral Alaska is bounded by Cook Inlet and the Kenai Mountains. Ground water is the predominant source of water for commercial, industrial, and domestic uses on the peninsula. Mean daily water use in an oil, gas, and chemical processing area north of Kenai is more than 3.5 million gallons. Unconsolidated sediments of glacial and fluvial origin are the most productive aquifers. In the upper (northwestern) peninsula, almost all water used is withdrawn from unconsolidated sediments, which may be as thick as 750 feet. In the lower peninsula, unconsolidated sediments are thinner and are absent on many hills. Water supplies in the lower peninsula are obtained from unconsolidated sediments and bedrock, and a public-water supply in parts of Homer is obtained from Bridge Creek. Throughout the peninsula, ground-water flow occurs primarily as localized flow controlled by permeability of aquifer materials and surface topography. The concentration of constituents analyzed in water from 312 wells indicated that the chemical quality of ground water for human consumption varies from marginal to excellent. Even though the median concentration of dissolved solids is low (152 milligrams per liter), much of the ground water on the peninsula does not meet water-quality regulations for public drinking water established by the U.S. Environmental Protection Agency (USEPA). About 8 percent of wells sampled yielded water having concentrations of dissolved arsenic that exceeded the USEPA primary maximum contaminant level of 50 micrograms per liter. Concentrations of dissolved arsenic were as great as 94 micrograms per liter. Forty-six percent of wells sampled yielded water having concentrations of dissolved iron greater than the USEPA secondary maximum contaminant level of 300 micrograms per liter. Unconsolidated sediments generally yield water having calcium, magnesium, and bicarbonate as its predominant ions. In some areas, ground water at

  4. Pleistocene leopards in the Iberian Peninsula: New evidence from palaeontological and archaeological contexts in the Mediterranean region

    NASA Astrophysics Data System (ADS)

    Sanchis, Alfred; Tormo, Carmen; Sauqué, Víctor; Sanchis, Vicent; Díaz, Rebeca; Ribera, Agustí; Villaverde, Valentín

    2015-09-01

    This study analyses the fossil record of leopards in the Iberian Peninsula. According to the systematic and morphometric features of new remains, identified mainly in Late Pleistocene palaeontological and archaeological sites of the Mediterranean region, they can be attributed to Panthera pardus Linnaeus 1758. The findings include the most complete leopard skeleton from the Iberian Peninsula and one of the most complete in Europe, found in a chasm (Avenc de Joan Guitón) south of Valencia. The new citations and published data are used to establish the leopard's distribution in the Iberian Peninsula, showing its maximum development during the Late Pleistocene. Some references suggest that the species survived for longer here (Lateglacial-Early Holocene) than in other parts of Europe. Finally, the contexts of appearance and origin of leopard remains are described and the processes of interaction with prehistoric human groups are assessed.

  5. Vegetation biomass change of the Bosoh Peninsula

    NASA Astrophysics Data System (ADS)

    Iwashita, K.; Asaka, T.; Nishikawa, H.; Kondoh, T.; Tahara, T.

    Since the 2001 eruption, the volcanic fumes from the Oyama of Miyakejima Island, located approximately 200 km southwest from the mainland of Japan, have affected the vegetation health and biomass of the Tokyo metropolitan area. In this study, we evaluated the potential for measuring/mapping relative forest damage/recovery in forests in the Bosoh Peninsula, Chiba Prefecture, Japan, using LANDSAT Enhanced Thematic Mapper data and ASTER Level-1B data. The simple ratio which is derived from the near-infrared and red reflective response was found to correlate well with ground-based measurements of forest damage caused by continuous SO2 contained in the volcanic fumes. Accumulated data by the synchronized field campaign observation of the Japanese cedar field spectra and by satellite analysis indicates the following interesting features: (1) regional differences of SO2 levels in the forestal area can be estimated by the simple spectrum ratio of the near-infrared and red bands of multispectral satellite data; (2) time-series images using the simple ratios indicated the location of still damaged and recovered forests between the 2001 eruption and 2003; (3) if the vegetations under study are homogeneous single-species with a similar leaf area index and a similar age, the simple ratio was useful to evaluate vegetation damage or recovery among individual forests throughout many of the forests in the Bosoh Peninsula; (4) the damage level of the Tokyo Bay side was found to be consistently higher than the Pacific Ocean side of the peninsula. This obvious difference is likely caused, not only by SO2 from Miyakejima Island, but also by long term and chronic discharged gas from heavy industrial complexes.

  6. Marine pelagic ecosystems: the west Antarctic Peninsula.

    PubMed

    Ducklow, Hugh W; Baker, Karen; Martinson, Douglas G; Quetin, Langdon B; Ross, Robin M; Smith, Raymond C; Stammerjohn, Sharon E; Vernet, Maria; Fraser, William

    2007-01-29

    The marine ecosystem of the West Antarctic Peninsula (WAP) extends from the Bellingshausen Sea to the northern tip of the peninsula and from the mostly glaciated coast across the continental shelf to the shelf break in the west. The glacially sculpted coastline along the peninsula is highly convoluted and characterized by deep embayments that are often interconnected by channels that facilitate transport of heat and nutrients into the shelf domain. The ecosystem is divided into three subregions, the continental slope, shelf and coastal regions, each with unique ocean dynamics, water mass and biological distributions. The WAP shelf lies within the Antarctic Sea Ice Zone (SIZ) and like other SIZs, the WAP system is very productive, supporting large stocks of marine mammals, birds and the Antarctic krill, Euphausia superba. Ecosystem dynamics is dominated by the seasonal and interannual variation in sea ice extent and retreat. The Antarctic Peninsula is one among the most rapidly warming regions on Earth, having experienced a 2 degrees C increase in the annual mean temperature and a 6 degrees C rise in the mean winter temperature since 1950. Delivery of heat from the Antarctic Circumpolar Current has increased significantly in the past decade, sufficient to drive to a 0.6 degrees C warming of the upper 300 m of shelf water. In the past 50 years and continuing in the twenty-first century, the warm, moist maritime climate of the northern WAP has been migrating south, displacing the once dominant cold, dry continental Antarctic climate and causing multi-level responses in the marine ecosystem. Ecosystem responses to the regional warming include increased heat transport, decreased sea ice extent and duration, local declines in icedependent Adélie penguins, increase in ice-tolerant gentoo and chinstrap penguins, alterations in phytoplankton and zooplankton community composition and changes in krill recruitment, abundance and availability to predators. The climate

  7. Marine pelagic ecosystems: the West Antarctic Peninsula

    PubMed Central

    Ducklow, Hugh W; Baker, Karen; Martinson, Douglas G; Quetin, Langdon B; Ross, Robin M; Smith, Raymond C; Stammerjohn, Sharon E; Vernet, Maria; Fraser, William

    2006-01-01

    The marine ecosystem of the West Antarctic Peninsula (WAP) extends from the Bellingshausen Sea to the northern tip of the peninsula and from the mostly glaciated coast across the continental shelf to the shelf break in the west. The glacially sculpted coastline along the peninsula is highly convoluted and characterized by deep embayments that are often interconnected by channels that facilitate transport of heat and nutrients into the shelf domain. The ecosystem is divided into three subregions, the continental slope, shelf and coastal regions, each with unique ocean dynamics, water mass and biological distributions. The WAP shelf lies within the Antarctic Sea Ice Zone (SIZ) and like other SIZs, the WAP system is very productive, supporting large stocks of marine mammals, birds and the Antarctic krill, Euphausia superba. Ecosystem dynamics is dominated by the seasonal and interannual variation in sea ice extent and retreat. The Antarctic Peninsula is one among the most rapidly warming regions on Earth, having experienced a 2°C increase in the annual mean temperature and a 6°C rise in the mean winter temperature since 1950. Delivery of heat from the Antarctic Circumpolar Current has increased significantly in the past decade, sufficient to drive to a 0.6°C warming of the upper 300 m of shelf water. In the past 50 years and continuing in the twenty-first century, the warm, moist maritime climate of the northern WAP has been migrating south, displacing the once dominant cold, dry continental Antarctic climate and causing multi-level responses in the marine ecosystem. Ecosystem responses to the regional warming include increased heat transport, decreased sea ice extent and duration, local declines in ice-dependent Adélie penguins, increase in ice-tolerant gentoo and chinstrap penguins, alterations in phytoplankton and zooplankton community composition and changes in krill recruitment, abundance and availability to predators. The climate/ecological gradients

  8. Spatial distribution and characteristics of permafrost in Hurd Peninsula, Livingston Island, Maritime Antarctic

    NASA Astrophysics Data System (ADS)

    Vieira, G.; Ramos, M.; Trindade, A.; Gruber, S.; Hauck, C.; Mora, C.; Batista, V.; Neves, M.; Pimpirev, C.; Kenderova, R.

    2009-04-01

    The Antarctic Peninsula is one of Earth's regions experiencing a faster increase on temperatures, with Mean Annual Air Temperatures (MAAT) rising ca. 2.5 °C in the last 50 years. The northerly location of the Antarctic Peninsula in respect to the Antarctic and its oceanic setting originate a milder and moister climate than in the Antarctic continent. The Northern Antarctic Peninsula is roughly located between the isotherms of MAAT of -1 °C to -8 °C at sea-level and therefore the northern tip and especially the South Shetlands are close to the limits of permafrost occurrence. If the observed warming trend is to continue in the near future, the region might suffer widespread permafrost degradation. Research on the permafrost environment of Hurd Peninsula has been taking place with systematical measurements by our group since January 2000 and currently we are able to provide a good overview of the spatial distribution and characteristics of permafrost terrain in Hurd Peninsula. Our research is based on shallow boreholes (<2m) with a time series of 8 years (30 and 275m asl) and on a series of boreholes with 1 year data: a 25m borehole in Reina Sofia Peak (275m), a 15m borehole in the vicinity of Reina Sofia Peak near Hurd Glacier (269m), a 5m borehole at the CALM-S near Ohridski Station (136m) and a 4m borehole at Papagalo (147m). Other shallow boreholes (1.5m) are being monitored at Incinerador point (25m) and Collado Ramos (115m). In 2006 Electrical Tomography Resistivity and refraction seismic profiles have been performed, providing us with a good overview of the general conditions of the permafrost terrain in the area. Air temperatures are measured at different sites accounting for altitude since a few years and during 3 summer campaigns the radiation balance was monitored continuously at two sites. Detailed geomorphological mapping of periglacial features has been conducted at a scale 1:5,000 providing important information about the geomorphological dynamics

  9. Climatic record of the Iberian peninsula from lake Moncortes' sediments

    NASA Astrophysics Data System (ADS)

    Cao, Min; Huguet, Carme; Rull, Valenti; Valero, Blas; Rosell-Mele, Antoni

    2014-05-01

    Climatic record of the Iberian peninsula from lake Moncortes' sediments Min Cao1, Carme Huguet1, Valenti Rull2, Blas L. Valero-Garces3, Antoni Rosell-Melé1,4 1Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Catalonia, Spain; 2Institut de Botanic de Barcelona (CSIC), Passeig del Migdia s/n, 08038, Barcelona, Spain, 3 Instituto Pirenaico de Ecologıa (CSIC), Avda. Montañana 1005, 50059 Zaragoza, Spain, 4Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Catalonia, Spain. The continuing buildup of industrial greenhouse gases in the atmosphere and concomitant increase in global temperatures has made much of the world's society aware that decades to centuries of environmental change lie ahead, and that these will have profound economic, political and societal impacts. The Iberian Peninsula lies in the boundary between tropical and subtropical climates and seems to amplify the climatic signals form the northern hemisphere through both atmospheric and water circulation feedbacks, making it an ideal site to monitor Northern hemisphere climate changes. This extreme sensitivity to climatic changes also makes the Iberian Peninsula extremely vulnerable to future climate changes. This is why understanding sensitivity to climate change and the consequences it will have on both climate and the hydrological cycle is key to implement preventive measures. The aim of our study is to come up with a high resolution quantitative reconstruction of climate variability (temperature, production and precipitation) in the Iberian Peninsula from lake sediments. We also want to establish the relation between those changes and the ones observed in both ice cores from Greenland and paleotemperature records from marine sediments of the continental Iberian margin. For these reasons we sampled a core in Moncortes (42.3N, 0.99E), a lake of karstic origin with an average depth of 25m and an area of 0

  10. Distribution of recoveries of Steller's Eiders banded on the lower Alaska Peninsula, Alaska

    USGS Publications Warehouse

    Dau, C.P.; Flint, P.L.; Petersen, M.R.

    2000-01-01

    Molting adult Steller's Eiders (Polysticta stelleri) were banded at Izembek Lagoon (1961-1998) and Nelson Lagoon (1995-1997) along the lower Alaska Peninsula to determine breeding distribution and movements. Of 52,985 Steller's Eiders banded, 347 were recovered. The overall low recovery rate may not be indicative of harvest levels but may be due to low reporting rates of bands. Almost all recoveries during summer were from Russia and recovery rates did not differ between sexes. We found no evidence that Steller's Eiders molting in specific locations were more likely to be recovered in specific geographic locations in Russia. Our recoveries suggest that Steller's Eiders molting along the Alaska Peninsula were from Russian breeding sites and from remnant breeding populations in Alaska.

  11. Seismic Hazard Assessment for the Baku City and Absheron Peninsula, Azerbaijan

    SciTech Connect

    Babayev, Gulam R.

    2006-03-23

    This paper deals with the seismic hazard assessment for Baku and the Absheron peninsula. The assessment is based on the information on the features of earthquake ground motion excitation, seismic wave propagation (attenuation), and site effect. I analyze active faults, seismicity, soil and rock properties, geological cross-sections, the borehole data of measured shear-wave velocity, lithology, amplification factor of each geological unit, geomorphology, topography, and basic rock and surface ground motions. To estimate peak ground acceleration (PGA) at the surface, PGA at the basic rock is multiplied by the amplification parameter of each surface layers. Quaternary soft deposits, representing a high risk due to increasing PGA values at surface, are studied in detail. For a near-zone target earthquake PGA values are compared to intensity at MSK-64 scale for the Absheron peninsula. The amplification factor for the Baku city is assessed and provides estimations for a level of a seismic motion and seismic intensity of the studied area.

  12. Military confidence building on the Korean Peninsula: possible first steps toward cooperation

    SciTech Connect

    Vannoni, M.

    1997-05-01

    The Korean Peninsula is one of the world`s most tense military confrontational sites. Nearly 2 million North Korean, South Korean, and U.S. troops face each other along the 255-km long military demarcation line. Confidence building measures (CBMs), particularly military ones, that address the security needs of both countries could decrease the danger of conflict and help create an environment where a peace regime might be negotiated. In spite of the present high level of mutual distrust, steps can still be taken to prepare for future development and implementation of CBMs. This paper defines some simple and specific first steps toward CBMs that might be useful on the Korean Peninsula.

  13. HEAVY METAL CONTAMINATION IN THE TAIMYR PENINSULA, SIBERIAN ARCTIC

    EPA Science Inventory

    The Taimyr Peninsula is directly north of the world's largest heavy metal smelting complex (Norilsk, Russia). Despite this proximity, there has been little research to examine the extent of contamination of the Taimyr Peninsula, primarily because of the remoteness of this area. W...

  14. Foraminifera from the Northern Olympic Peninsula, Washington

    USGS Publications Warehouse

    Rau, Weldon W.

    1964-01-01

    Foraminifera from a Tertiary sequence that crops out on the northern part of the Olympic Peninsula, Wash., show stratigraphic and ecologic significance. Forty-two species that are important both to correlations and to ecologic interpretations are illustrated and systematically discussed. The Foraminifera indicate that some of the rocks may be as old as early Eocene. The oldest rocks are tentatively referred to the Penutian stage of Mallory. Other parts of the sequence are referred to the Ulatisian and Narizian stages of Mallory, the Refugian stage of Schenck and Kieinpell, and the Zemorrian and Saucesian stages of Kleinpell. Several short periods of shallow, sheltered sea conditions are suggested by the Foraminifera from several parts of the stratigraphic sequence, but Foraminifera from most of the rocks suggest relatively deep, open-sea conditions. With the exception of shallow, warm-water conditions in rocks of probable middle Eocene age, the Foraminifera suggest that cool-to-cold water temperatures, regardless of depth, prevailed during the deposition of most of the rocks of Tertiary age in the northern Olympic Peninsula.

  15. STS-42 Earth observation of Kamchatka Peninsula

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-42 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, with an electronic still camera (ESC) is of Kamchatka Peninsula in Russia. Mid-afternoon sun projects long shadows from volcanoes on the Kamchatka Peninsula. This flat-topped volcano with the sharp summit crater is Tobachinsky, over 3,085 kilometers high. Its last major eruption was in 1975 and 1976, but it has been very active since the middle of the Sixteenth Century. The shadows cast by the low sunlight brings out the dramatic relief of the volcano as well as the smaller morphologic features. Electronic still photography is a relatively new technology that enables a camera to electronically capture and digitize an image with resolution approaching film quality. The digital images from STS-42 were stored on a disk and brought home with the flight crewmembers for processing. ESC was developed by the JSC Man-Systems Division and this mission's application of it is part of a continuing evolutionary development le

  16. STS-42 Earth observation of Kamchatka Peninsula

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-42 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, with an electronic still camera (ESC) is of Kamchatka Peninsula in Russia. Mid-afternoon sun projects long shadows from volcanoes on the Kamchatka Peninsula. This flat-topped volcano with the sharp summit crater is Tobachinsky, over 3,085 kilometers high. Its last major eruption was in 1975 and 1976, but it has been very active since the middle of the Sixteenth Century. The shadows cast by the low sunlight brings out the dramatic relief of the volcano as well as the smaller morphologic features. For example, the small hills in the foreground and behind the central volcano are cinder cones, approximately only 200 meters high. Note the sharp triangular shadow from the conical volcano at right. Electronic still photography is a relatively new technology that enables a camera to electronically capture and digitize an image with resolution approaching film quality. The digital images from STS-42 were stored on a disk

  17. The climatology of dust aerosol over the arabian peninsula

    NASA Astrophysics Data System (ADS)

    Shalaby, A.; Rappenglueck, B.; Eltahir, E. A. B.

    2015-01-01

    Dust storms are considered to be a natural hazard over the Arabian Peninsula, since they occur all year round with maximum intensity and frequency in Spring and Summer. The Regional Climate Model version 4 (RegCM4) has been used to study the climatology of atmospheric dust over the Arabian Peninsula from 1999 to 2012. This relatively long simulation period samples the meteorological conditions that determine the climatology of mineral dust aerosols over the Arabian Peninsula. The modeled Aerosol Optical Depth (AOD) has been compared against ground-based observations of three Aerosol Robotic Network (AERONET) stations that are distributed over the Arabian Peninsula and daily space based observations from the Multi-angle Imaging SpectroRadiometer (MISR), the Moderate resolution Imaging SpectroRadimeter (MODIS) and Ozone Monitoring Instrument (OMI). The large scale atmospheric circulation and the land surface response that lead to dust uplifting have been analyzed. While the modeled AOD shows that the dust season extends from March to August with two pronounced maxima, one over the northern Arabian Peninsula in March with AOD equal to 0.4 and one over the southern Arabian Peninsula in July with AOD equal to 0.7, the observations show that the dust season extends from April to August with two pronounced maxima, one over the northern Arabian Peninsula in April with AOD equal to 0.5 and one over the southern Arabian Peninsula in July with AOD equal to 0.5. In spring a high pressure dominates the Arabian Peninsula and is responsible for advecting dust from southern and western part of the Arabian Peninsula to northern and eastern part of the Peninsula. Also, fast developed cyclones in northern Arabian Peninsula are responsible for producing strong dust storms over Iraq and Kuwait. However, in summer the main driver of the surface dust emission is the strong northerly wind ("Shamal") that transport dust from the northern Arabian Peninsula toward south parallel to the

  18. Recent Crustal Deformations In Kii Peninsula, Southwest Japan Derived From Dense GPS Observations: Interplate Coupling And 2004 Earthquake Sequence SE Off Kii Peninsula

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Onoue, K.; Ohya, F.; Hoso, Y.; Sato, K.; Segawa, K.; Fujita, Y.

    2004-12-01

    Kii peninsula, southwest Japan is located close to the Nankai trough and suffers from the subduction of the Philippine Sea plate. Deeper part of the source region of interplate earthquakes, such as 1946 Nankai is beneath this peninsula. Therefore it is important to reveal detailed crustal deformations in this area for the purpose of understanding of generation process of interplate earthquakes and long-term forecast of their occurrence. We established 10 GPS observation sites filling the gaps of the GEONET operated by GSI along two lines nearly parallel to the relative motion between the Philippine Sea and Amurian plates. Resultant average spacing is 5~10km. We have repeated the campaign survey of this traverse using dual-frequency receivers since March 2001. So far, we have collected data from 4 campaigns done every March and can discuss displacement/velocity field during the recent 3 years. We calculate coordinates of our campaign sites with GSI_fs permanent sites in ITRF2000. We use the GIPSY/OASIS II software with JPL precise ephemeredes in the analysis. Velocity of each site is calculated referring to the first campaign and converted to the relative velocity to the Amurian plate using the Euler vector by Heki et al. (1999). Velocities derived from 2001 and 2002 campaigns are about 20mm/yr in the middle part of Kii peninsula and 35mm/yr at its southern tip, respectively, relative to the Amurian plate. Their directions are WNW. The gradient is almost linear up to 33.8N and there is no significant change in gradient in northern part. Velocities along the eastern line are a little smaller than those on the western line. We apply a model with multiple fault segments to this velocity field and estimate their slip deficit rates. We adopt the 9 segments around Kii peninsula from the fault model of Sagiya and Thatcher (1999). Estimated slip deficit rates are as large as 70 mm/yr that is slightly larger than the relative plate motion. If we add deeper extension to the

  19. Sinai Peninsula, Shaded Relief and Colored Height

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Sinai Peninsula, located between Africa and Asia, is a result of those two continents pulling apart from each other. Earth's crust is cracking, stretching, and lowering along the two northern branches of the Red Sea, namely the Gulf of Suez, seen here on the west (left), and the Gulf of Aqaba, seen to the east (right). This color-coded shaded relief image shows the triangular nature of the peninsula, with the coast of the Mediterranean Sea forming the northern side of the triangle. The Suez Canal can be seen as the narrow vertical blue line in the upper left connecting the Red Sea to the Mediterranean.

    The peninsula is divided into three distinct parts; the northern region consisting chiefly of sandstone, plains and hills, the central area dominated by the Tih Plateau, and the mountainous southern region where towering peaks abound. Much of the Sinai is deeply dissected by river valleys, or wadis, that eroded during an earlier geologic period and break the surface of the plateau into a series of detached massifs with a few scattered oases.

    Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.

    Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot

  20. Airborne pollen trends in the Iberian Peninsula.

    PubMed

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants.

  1. Tropospheric ozone variability over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Kulkarni, Pavan S.; Bortoli, D.; Salgado, R.; Antón, M.; Costa, M. J.; Silva, A. M.

    2011-01-01

    To study tropospheric ozone variability over the Iberian Peninsula (IP), NASA Langley TOR data have been analyzed for the 1979-2005 period. The maximum tropospheric ozone concentration over the entire IP was found in June (˜41 DU) and a minimum in December (˜29 DU). However the maximum tropospheric ozone concentration was found over West Atlantic Coast (WAC) (˜44 DU), followed by Mediterranean Coast (MC) (˜42 DU), North Atlantic Coast (NAC) (˜41 DU), Central Iberian Peninsula (CIP) (˜40 DU) and Pyrenees Mountain Range (PMR) (˜39 DU) during June-July. The high concentration of tropospheric ozone in July over the Atlantic Ocean near IP is due to the presence of Azores anticyclone and related photochemistry and dynamics, and affects the observed higher tropospheric ozone concentration over WAC zone. Strong seasonal cycle in tropospheric ozone concentration has been observed with large variation over NAC (˜49%), followed by WAC (˜48%) and MC (˜41%) compared to CIP and PMR (˜38%) zones. When the data are compared over the IP for the two periods (1979-1993 and 1997-2005), a systematic increase in the number of months with higher tropospheric ozone concentration has been observed during the second period with respect to the first. These increases are almost 8% to 24% over NAC, 6% to 17% over WAC, 5% to 24% over CIP, 6% to 23% over MC and 13% to 18% over PMR, zones. It has been observed that topography, climatology and population density distribution plays a crucial role in the variability of tropospheric ozone concentration over the IP.

  2. Eruption of Shiveluch Volcano, Kamchatka Peninsula

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On March 29, 2007, the Shiveluch Volcano on the Russian Federation's Kamchatka Peninsula erupted. According to the Alaska Volcano Observatory the volcano underwent an explosive eruption between 01:50 and 2:30 UTC, sending an ash cloud skyward roughly 9,750 meters (32,000 feet), based on visual estimates. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard NASA's Aqua satellite took this picture at 02:00 UTC on March 29. The top image shows the volcano and its surroundings. The bottom image shows a close-up view of the volcano at 250 meters per pixel. Satellites often capture images of volcanic ash plumes, but usually as the plumes are blowing away. Plumes have been observed blowing away from Shiveluch before. This image, however, is different. At the time the Aqua satellite passed overhead, the eruption was recent enough (and the air was apparently still enough) that the ash cloud still hovered above the summit. In this image, the bulbous cloud casts its shadow northward over the icy landscape. Volcanic ash eruptions inject particles into Earth's atmosphere. Substantial eruptions of light-reflecting particles can reduce temperatures and even affect atmospheric circulation. Large eruptions impact climate patterns for years. A massive eruption of the Tambora Volcano in Indonesia in 1815, for instance, earned 1816 the nickname 'the year without a summer.' Shiveluch is a stratovolcano--a steep-sloped volcano composed of alternating layers of solidified ash, hardened lava, and volcanic rocks. One of Kamchatka's largest volcanoes, it sports a summit reaching 3,283 meters (10,771 feet). Shiveluch is also one of the peninsula's most active volcanoes, with an estimated 60 substantial eruptions in the past 10,000 years.

  3. Population model for Alaska Peninsula sea otters. Final report

    SciTech Connect

    Eberhardt, L.L.; Siniff, D.B.

    1988-12-31

    This study was conducted to provide a basis for assessing risks of oil spills to sea otter populations along the Alaska Peninsula. The principal efforts were devoted to analyzing the available data on population dynamics. Curves characterizing survivorship and reproduction for sea otters were devised and fitted to several data sets. A detailed review was conducted of methods of assessing population dynamics data, and several new techniques (e.g., bootstrapping) were applied to available data. A simplified model for use with Alaska Peninsula sea otter populations was devised and implemented in a 'spreadsheet' format. Various aspects of model development and data on population size in Alaska Peninsula areas were reviewed.

  4. Geomorphic status of regulated rivers in the Iberian Peninsula.

    PubMed

    Lobera, G; Besné, P; Vericat, D; López-Tarazón, J A; Tena, A; Aristi, I; Díez, J R; Ibisate, A; Larrañaga, A; Elosegi, A; Batalla, R J

    2015-03-01

    River regulation by dams modifies flow regimes, interrupts the transfer of sediment through channel networks, and alters downstream bed dynamics, altogether affecting channel form and processes. So far, most studies on the geomorphic impacts of dams are restricted to single rivers, or even single river stretches. In this paper we analyse the geomorphic status of 74 river sites distributed across four large basins in the Iberian Peninsula (i.e. 47 sites located downstream of dams). For this purpose, we combine field data with hydrological data available from water agencies, and analyse historical (1970) and current aerial photographs. In particular, we have developed a Geomorphic Status (GS) index that allows us to assess the physical structure of a given channel reach and its change through time. The GS encompasses a determination of changes in sedimentary units, sediment availability, bar stability and channel flow capacity. Sites are statistically grouped in four clusters based on contrasted physical and climate characteristics. Results emphasise that regulation changes river's flow regime with a generalized reduction of the magnitude and frequency of floods (thus flow competence). This, in addition to the decrease downstream sediment supply, results in the loss of active bars as they are encroached by vegetation, to the point that only reaches with little or no regulation maintain exposed sedimentary deposits. The GS of regulated river reaches is negatively correlated with magnitude of the impoundment (regulation). Heavily impacted reaches present channel stabilization and, in contrast to the hydrological response, the distance and number of tributaries do not reverse the geomorphic impact of the dams. Stabilization limits river dynamics and may contribute to the environmental degradation of the fluvial ecosystem. Overall, results describe the degree of geomorphological alteration experienced by representative Iberian rivers mostly because of regulation

  5. Geomorphic status of regulated rivers in the Iberian Peninsula.

    PubMed

    Lobera, G; Besné, P; Vericat, D; López-Tarazón, J A; Tena, A; Aristi, I; Díez, J R; Ibisate, A; Larrañaga, A; Elosegi, A; Batalla, R J

    2015-03-01

    River regulation by dams modifies flow regimes, interrupts the transfer of sediment through channel networks, and alters downstream bed dynamics, altogether affecting channel form and processes. So far, most studies on the geomorphic impacts of dams are restricted to single rivers, or even single river stretches. In this paper we analyse the geomorphic status of 74 river sites distributed across four large basins in the Iberian Peninsula (i.e. 47 sites located downstream of dams). For this purpose, we combine field data with hydrological data available from water agencies, and analyse historical (1970) and current aerial photographs. In particular, we have developed a Geomorphic Status (GS) index that allows us to assess the physical structure of a given channel reach and its change through time. The GS encompasses a determination of changes in sedimentary units, sediment availability, bar stability and channel flow capacity. Sites are statistically grouped in four clusters based on contrasted physical and climate characteristics. Results emphasise that regulation changes river's flow regime with a generalized reduction of the magnitude and frequency of floods (thus flow competence). This, in addition to the decrease downstream sediment supply, results in the loss of active bars as they are encroached by vegetation, to the point that only reaches with little or no regulation maintain exposed sedimentary deposits. The GS of regulated river reaches is negatively correlated with magnitude of the impoundment (regulation). Heavily impacted reaches present channel stabilization and, in contrast to the hydrological response, the distance and number of tributaries do not reverse the geomorphic impact of the dams. Stabilization limits river dynamics and may contribute to the environmental degradation of the fluvial ecosystem. Overall, results describe the degree of geomorphological alteration experienced by representative Iberian rivers mostly because of regulation

  6. Fluid Overpressure and Connections to Seismicity, Cascadia Tertiary Accretionary Prism, Olympic Peninsula

    NASA Astrophysics Data System (ADS)

    Rotman, H.; Mattinson, C. G.

    2010-12-01

    Metamorphic dehydration reactions and fluid movement in accretionary prisms have been linked to the recently discovered episodic tremor and slip (ETS) earthquake events along subduction zones, but prior studies lack the detail to effectively test the hypothesis that fluid flow triggers ETS events. I conducted field work along a 52.5 km transect on the Olympic Peninsula metasedimentary accretionary prism of the Cascadia subduction zone, and collected approximately 40 representative samples of sandstone and mudrock that were buried to 6-15 km. This depth range intersects the 10-50 km depth range of ETS events. My objectives are to quantify the water flow recorded in rocks of the Olympic Peninsula via petrographic, whole rock, and isotopic analyses to test the prediction that water release increases at ~10 km depth, creating fluid overpressure needed to trigger seismicity. I calculated that on the Olympic Peninsula 1 km3 of 50% sandstone and 50% mudrock loses ~105 kg H2O/yr during burial from 6-14 km depth, comparable to the values expected from large-scale fluid budget models. Quartz veins that compose 0.5-1% of the Obstruction Peak site (~14 km burial depth) are important records of fluid flow quantity and origin. δ18O values of +11.8‰ to +15.2‰ indicate that vein H2O originated from metamorphic reactions. Flow recorded by 1 km3 of rock containing 0.5-1% quartz veins is >106 kg H2O/yr, comparable to the values 2 × 107 to 2 × 108 kg H2O/yr modeled at compositionally similar subduction zones to produce fluid overpressure conditions. I observed fibrous quartz veins, which also indicate fluid overpressure conditions were reached and support my H2O flow estimates. Therefore, Olympic Peninsula rocks at depths of ~10-14 km record dehydration and fluid overpressure large enough to trigger subduction zone seismicity.

  7. Data Collection in the Arabian Peninsula for Nuclear Explosion Monitoring

    SciTech Connect

    Rodgers, A; Tkalcic, H; Al-Amri, A M S

    2003-07-11

    We report results from the second year of our project (ROA0101-35) to collect seismic event and waveform data recorded in and around the Arabian Peninsula. This effort involves several elements. We have a temporary broadband seismic station operating near the IMS primary array site (PS38) in central Saudi Arabia. We recently installed two temporary broadband stations in the United Arab Emirates (funded by NNSA NA-24 Office of Non-Proliferation & International Security). We are working with King Abdulaziz city for Science and Technology to collect and analyze data from the Saudi National Seismic Network, that consist of 37 digital three-component stations (26 broadband and 11 short-period). We are collaborating with Kuwait Institute for Scientific Research (KISR) to analyze data from their 8 station national seismic network. We participated in the Workshop on Reference Events odnear the Dead Sea Rift held in Paris, France in October 2002. In this paper we present results of these efforts including integration of the raw data into LLNL's Seismic Research Database and preliminary analysis of event locations and source parameters and inference of earth structure.

  8. Heat flow through the sea bottom around the Yucatan Peninsula

    SciTech Connect

    Khutorskoy, M.D.; Kononov, V.I.; Polyak, B.G. ); Fernandez, R. ); Matveev, V.G.; Rot, A.A. )

    1990-02-10

    Heat flow studies were conducted in January-February 1987, off the Atlantic Coast of Mexico on board the R/V Akademik Nikolai Strakhov. Two areas were surveyed, one transecting the Salt Dome Province and the Campeche Canyon, in the Gulf of Mexico, and the other, on the eastern flank of the Yucatan Peninsula. Conductive heat flow through the bottom sediments was determined as the product of vertical temperature gradient and in situ thermal conductivity, measured with a thermal probe using a multithermistor array and real-time processing capabilities. Forward two-dimensional modeling allows one to estimate heat flow variations at both sites from local disturbances and to obtain average heat flow values of 51 mW/m{sup 2} for the transect within the Gulf of Mexico and 38 and 69 mW/m{sup 2} for two basins within the Yucatan area. Sea bottom relief has a predominant effect over other environmental factors in the scatter of heat flow determination in the Gulf of Mexico.

  9. Shaded Relief with Height as Color, Yucatan Peninsula, Mexico

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This shaded relief image of Mexico's Yucatan Peninsula show a subtle, but unmistakable, indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary Extinction, the event 65 million years ago that marked the sudden extinction of the dinosaurs as well as the majority of life then on Earth.

    Most of the peninsula is visible here, along with the island of Cozumel off the east coast. The Yucatan is a plateau composed mostly of limestone and is an area of very low relief with elevations varying by less than a few hundred meters (about 500 feet.) In this computer-enhanced image the topography has been greatly exaggerated to highlight a semicircular trough, the darker green arcing line at the upper left corner of the peninsula. This trough is only about 3 to 5 meters (10 to 15 feet) deep and is about 5 km. wide (3 miles), so subtle that if you walked across it you probably would not notice it, and is a surface expression of the crater's outer boundary. Scientists believe the impact, which was centered just off the coast in the Caribbean, altered the subsurface rocks such that the overlying limestone sediments, which formed later and erode very easily, would preferentially erode on the vicinity of the crater rim. This formed the trough as well as numerous sinkholes (called cenotes) which are visible as small circular depressions.

    Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwestern slopes appear bright and southeastern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.

    For a smaller, annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site] (Large

  10. Palaeomagnetic constraints from granodioritic plutons (Jiaodong Peninsula): New insights on Late Mesozoic continental extension in Eastern Asia

    NASA Astrophysics Data System (ADS)

    Charles, Nicolas; Chen, Yan; Augier, Romain; Gumiaux, Charles; Lin, Wei; Faure, Michel; Monié, Patrick; Choulet, Flavien; Wu, Fuyuan; Zhu, Rixiang; Wang, Qingchen

    2011-08-01

    Mechanism and kinematics of the Late Mesozoic continental extension event of Eastern Asia are still debated. In order to better constrain its evolution, two granodioritic plutons of the Jiaodong Peninsula have been chosen as targets for a time-constrained palaeomagnetic study. Indeed, plutons are devoid of visible deformation, did not experience rotation along horizontal axis and are precisely dated by U/Pb and 40Ar/ 39Ar methods. Multidomain (MD) magnetite has been identified as the principal magnetic remanent carrier. The interpolation of existing and new U/Pb and 40Ar/ 39Ar ages revealed that characteristic remanent magnetisation was acquired in a narrow range of 116 ± 2 Ma. Twenty out of 27 sites present stable magnetic directions calculated from high-temperature or high-coercive components. The observations of the solo normal magnetic polarity for this palaeomagnetic collection and of the magnetic remanent age consistent with the Cretaceous Normal Superchron (CNS) argue that the characteristic magnetic remanence may be considered as primary. Detailed field observations of the intrusive relationship between the plutons and country rocks and Anisotropy of Magnetic Susceptibility (AMS) study reveal the absence of the subsequent deformation of plutons, or rigid rotation of plutons along a horizontal axis. Two palaeomagnetic poles have been therefore calculated from these plutons. Among 12 out 15 Cretaceous palaeomagnetic poles, including the two new poles provided by this study, from the Jiaodong Peninsula and on both sides of Tan-Lu and Muping-Jimo faults are statistically consistent. As a result, the Jiaodong Peninsula behaved as a rigid block as internal deformation appears negligible. The remaining three derived poles are probably due to the secular variation or/and the vicinity of fault zones near of the palaeomagnetic sampling site. Thus, they can not be applied to the peninsula-scaled tectonics. Comparison of these time-constrained Cretaceous

  11. Regional differences of column aerosol parameters in western Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Obregón, M. A.; Pereira, S.; Wagner, F.; Serrano, A.; Cancillo, M. L.; Silva, A. M.

    2012-12-01

    This study presents a characterization of aerosols columnar properties measured at three different AERONET sites in the western part of the Iberian Peninsula, namely Évora and Cabo da Roca, in Portugal, and Cáceres, in Spain, during the period from 2005 to 2010. AERONET level 2.0 products have been analyzed. The comparison of these three stations has great interest because it has not been conducted yet and it allows to characterize the aerosols of a wide region in western Iberian Peninsula by a long-term analysis of their aerosol properties. In addition, it allows analyzing the possible differences in these properties between the three sites located at different distances from the coast. The results show differences between the aerosol optical depth at 440 and 1020 nm at the three stations, being the mean values in Cabo da Roca at 1020 and 440 nm (0.08 and 0.16) slightly higher than in the other two stations (Évora: 0.06 and 0.15; Cáceres: 0.05 and 0.14). Greater differences among the three stations are found for the Ångström exponent values. Thus, Cáceres shows the highest mean value (1.33), followed by Évora (1.14) and, finally, by Cabo da Roca (1.00) which exhibits the smallest median α values due to the presence of coarse sea salt particles and high atmospheric humidity. These values are consistent with the values of volume size distribution, exhibiting a greater value of large particles at Cabo da Roca. The mean values of the single scattering albedo (ω) have been also analyzed, obtaining higher results as the coast is approached: Cabo da Roca: ω (440) = 0.95; ω (1020) = 0.96, Évora: ω (440) = 0.93; ω (1020) = 0.95 and Cáceres: ω (440) = 0.88; ω (1020) = 0.83. The differences between the three stations are explained in terms of the distance to the coast and to the occasional arrival of diverse air masses transporting different aerosol types to each station. One classification method proposed for the study region has been applied to multi

  12. 3-D Perspective Kamchatka Peninsula Russia

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This perspective view shows the western side of the volcanically active Kamchatka Peninsula in eastern Russia. The image was generated using the first data collected during the Shuttle Radar Topography Mission (SRTM). In the foreground is the Sea of Okhotsk. Inland from the coast, vegetated floodplains and low relief hills rise toward snow capped peaks. The topographic effects on snow and vegetation distribution are very clear in this near-horizontal view. Forming the skyline is the Sredinnyy Khrebet, the volcanic mountain range that makes up the spine of the peninsula. High resolution SRTM topographic data will be used by geologists to study how volcanoes form and to understand the hazards posed by future eruptions. This image was generated using topographic data from SRTM and an enhanced true-color image from the Landsat 7 satellite. This image contains about 2,400 meters (7,880 feet) of total relief. The topographic expression was enhanced by adding artificial shading as calculated from the SRTM elevation model. The Landsat data was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota. SRTM, launched on February 11, 2000, used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. To collect the 3-D SRTM data, engineers added a 60- meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. SRTM collected three dimensional measurements of nearly 80 percent of the Earth's surface. SRTM is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. Size: 33.3 km (20.6 miles) wide x 136 km (84 miles) coast to skyline. Location: 58.3 deg. North lat., 160 deg. East long. Orientation: Easterly view, 2 degrees

  13. Shaded Relief Color Wrapped, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This shaded relief topographic image shows the western side of the volcanically active Kamchatka Peninsula, Russia. The data are from the first C-band mapping swath of the Shuttle Radar Topography Mission (SRTM). On the left side are five rivers, which flow northwest to the Sea of Okhotsk. These rivers are, from the south to north, Tigil, Amanina, Voyampolka, Zhilovaya, and Kakhtana. The broad, flat floodplains of the rivers are shown in yellow. These rivers are important spawning grounds for salmon. In the right side of the image is the Sredinnyy Khrebet, the volcanic mountain range that makes up the 3spine2 of the peninsula. The cluster of hills to the lower right is a field of small dormant volcanoes. High resolution SRTM topographic data will be used by geologists to study how volcanoes form and understand the hazards posed by future eruptions.

    This image was generated using topographic data from the Shuttle Radar Topography Mission. Colors show the elevation as measured by SRTM. Each cycle of colors (from red through green back to red) represents an equal amount of elevation difference (400 meters, or 1300 feet)similar to contour lines on a standard topographic map. This image contains about 2300 meters (7500 feet) of total relief. For the shading, a computer-generated artificial light source illuminates the elevation data to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. Shaded relief maps are commonly used in applications such as geologic mapping and land use planning.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast

  14. 3-D Perspective View, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This perspective view shows the western side of the volcanically active Kamchatka Peninsula in eastern Russia. The image was generated using the first data collected during the Shuttle Radar Topography Mission (SRTM). In the foreground is the Sea of Okhotsk. Inland from the coast, vegetated floodplains and low relief hills rise toward snow capped peaks. The topographic effects on snow and vegetation distribution are very clear in this near-horizontal view. Forming the skyline is the Sredinnyy Khrebet, the volcanic mountain range that makes up the spine of the peninsula. High resolution SRTM topographic data will be used by geologists to study how volcanoes form and to understand the hazards posed by future eruptions.

    This image was generated using topographic data from SRTM and an enhanced true-color image from the Landsat 7 satellite. This image contains about 2,400 meters (7,880 feet) of total relief. The topographic expression was enhanced by adding artificial shading as calculated from the SRTM elevation model. The Landsat data was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

    SRTM, launched on February 11, 2000, used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar(SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. To collect the 3-D SRTM data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. SRTM collected three-dimensional measurements of nearly 80 percent of the Earth's surface. SRTM is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, D.C.

    Size: 33.3 km (20.6 miles) wide x

  15. SRTM Anaglyph: Sredinnyy Khrebet, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Kamchatka Peninsula in eastern Russia is shown in this scene created from a preliminary elevation model derived from the first data collected during the Shuttle Radar Topography Mission (SRTM) on February 12, 2000. Sredinnyy Khrebet, the mountain range that makes up the spine of the peninsula, is a chain of active volcanic peaks. Pleistocene and recent glaciers have carved the broad valleys and jagged ridges that are common here. The relative youth of the volcanism is revealed by the topography as infilling and smoothing of the otherwise rugged terrain by lava, ash, and pyroclastic flows, particularly surrounding the high peaks in the south central part of the image. Elevations here range from near sea level up to 2,618 meters (8,590 feet).

    This anaglyph was produced by first shading a preliminary SRTM elevation model. The stereoscopic effect was then created by generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by

  16. An intersection model for estimating sea otter mortality along the Kenai Peninsula

    USGS Publications Warehouse

    Bodkin, J.L.; Udevitz, M.S.; Loughlin, T.R.

    1994-01-01

    We developed an intersection model to integrate parameters estimated from three distinct data sets that resulted from the Exxon Valdez oil spill: (1) the distribution, amount, and movements of spilled oil; (2) the distribution and abundance of sea otters along the Kenai Peninsula; and (3) the estimates of site-specific sea otter mortality relative to oil exposure from otters captured for rehabilitation and from collected carcasses. In this chapter, we describe the data sets and provide examples of how they can be used in the model to generate acute loss estimates. We also examine the assumptions required for the model and provide suggestions for improving and applying the model.

  17. Evidence for Bombus occidentalis (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho

    PubMed Central

    Rhoades, Paul R.; Koch, Jonathan B.; Waits, Lisette P.; Strange, James P.; Eigenbrode, Sanford D.

    2016-01-01

    Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range. PMID:26856817

  18. Evidence for Bombus occidentalis (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho.

    PubMed

    Rhoades, Paul R; Koch, Jonathan B; Waits, Lisette P; Strange, James P; Eigenbrode, Sanford D

    2016-01-01

    Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range.

  19. Evidence for Bombus occidentalis (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho.

    PubMed

    Rhoades, Paul R; Koch, Jonathan B; Waits, Lisette P; Strange, James P; Eigenbrode, Sanford D

    2016-01-01

    Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range. PMID:26856817

  20. Microbiology of Kamchatka Peninsula Hot Springs

    NASA Astrophysics Data System (ADS)

    Bonch-Osmolovsk, E.

    2005-12-01

    Hot springs of Uzon Caldera, Geyser Valley, Moutnovsky Volcano (Kamchatka Peninsula) served as the sources of isolation of numerous thermophilic prokaryotes, many of them representing new taxa. Among new isolates there were hyperthermophilic archaea - neutrophilic or acidophilic anaerobic organotrophs, able to use a wide range of polymeric organic substrates. Bacterial isolates were in majority represented by moderate thermophiles - organotrophs and lithoautotrophs. Latter group consisted of anaerobes oxidizing molecular hydrogen in the course of sulfate, sulfur or iron reduction, and of anaerobic CO-oxidizing, hydrogen-producing bacteria. Some of new isolates represented deep phylogenetic lineages in Bacteria domain. Microbial activity in Kamchatka hot springs was studied by means of radioisotopic tracing. The rates of methanogenesis, acetogenesis, inorganic carbon assimilation, acetate oxidation were determined in three different hot springs with pH ranging from 3.0 to 8.5 and water temeperature being in the range from 55 to 85oC. The results indicated the presence and activity of novel metabolic groups of thermophilic prokaryotes that so far have not been known in laboratory cultures.

  1. Trichinella pseudospiralis in the Iberian peninsula.

    PubMed

    Zamora, M J; Alvarez, M; Olmedo, J; Blanco, M C; Pozio, E

    2015-06-15

    Nematode worms of the genus Trichinella are zoonotic parasites circulating in most continents, including Europe. In Spain, Trichinella spiralis and Trichinella britovi are highly prevalent in wildlife but seldom in domestic pigs. In Portugal, only T. britovi was documented in wild carnivores. In the period 2006-2013 in Spain, 384 (0.0001%) pigs and 1399 (0.20%) wild boars (Sus scrofa) were positive for Trichinella spp. larvae, which were identified as T. spiralis or T. britovi. In 2014, Trichinella pseudospiralis larvae were isolated from a wild boar hunted in the Gerona province, Cataluña region, North-East of Spain, near the border to France. This is the first report of T. pseudospiralis in the Iberian peninsula, which suggests a broad distribution area of this zoonotic nematode in Europe. Since larvae of this Trichinella species do not encapsulate in the host muscles, they can be detected only by artificial digestion of muscle samples. T. pseudospiralis is the only Trichinella species infecting both mammals and birds. Birds can spread this pathogen over great distances including islands triggering new foci of infections in areas previously considered at low risk for this pathogen.

  2. Environmental geophysics at the Southern Bush River Peninsula, Aberdeen Proving Ground, Maryland

    SciTech Connect

    Davies, B.E.; Miller, S.F.; McGinnis, L.D.

    1995-05-01

    Geophysical studies have been conducted at five sites in the southern Bush River Peninsula in the Edgewood Area of Aberdeen Proving Ground, Maryland. The goals of the studies were to identify areas containing buried metallic objects and to provide diagnostic signatures of the hydrogeologic framework of the site. These studies indicate that, during the Pleistocene Epoch, alternating stands of high and low sea level resulted in a complex pattern of channel-fill deposits. Paleochannels of various sizes and orientations have been mapped throughout the study area by means of ground-penetrating radar and EM-31 techniques. The EM-31 paleochannel signatures are represented onshore either by conductivity highs or lows, depending on the depths and facies of the fill sequences. A companion study shows the features as conductivity highs where they extend offshore. This erosional and depositional system is environmentally significant because of the role it plays in the shallow groundwater flow regime beneath the site. Magnetic and electromagnetic anomalies outline surficial and buried debris throughout the areas surveyed. On the basis of geophysical measurements, large-scale (i.e., tens of feet) landfilling has not been found in the southern Bush River Peninsula, though smaller-scale dumping of metallic debris and/or munitions cannot be ruled out.

  3. A Study of the San Andreas Slip Rate on the San Francisco Peninsula, California

    NASA Astrophysics Data System (ADS)

    Feigelson, L. M.; Prentice, C.; Grove, K.; Caskey, J.; Ritz, J. F.; Leslie, S.

    2008-12-01

    The most recent large earthquake on the San Andreas Fault (SAF) along the San Francisco Peninsula was the great San Francisco earthquake of April 18, 1906, when a Mw= 7.8 event ruptured 435-470 km of the northern SAF. The slip rate for this segment of the SAF is incompletely known but is important for clarifying seismic hazard in this highly urbanized region. A previous study south of our site has found an average slip rate of 17±4 mm/yr for the late Holocene on the San Francisco Peninsula segment of the SAF. North of the Golden Gate, the SAF joins the San Gregorio Fault with an estimated slip rate of 6 mm/yr. A trench study north of where the two faults join has produced an average late Holocene slip rate of 24±3 mm/yr. To refine slip-rate estimates for the peninsula segment of the SAF, we excavated a trench across the fault where we located an abandoned channel between the San Andreas and Lower Crystal Springs reservoirs. This abandoned channel marks the time when a new channel cut across the SAF; the new channel has since been offset in a right-lateral sense about 20 m. The measured amount of offset and the age of the youngest fluvial sediments in the abandoned channel will yield a slip rate for the San Francisco Peninsula segment of the SAF. We excavated a trench across the abandoned channel and logged the exposed sediments. Our investigation revealed channel-fill alluvium incised and filled by probable debris flow sediments, and a wide fault zone in bedrock, west of the channel deposits. The most prominent fault is probably the strand that moved in 1906. We completed a total-station survey to more precisely measure the offset stream, and to confirm that the fault exposed in the trench aligns with a fence that is known to have been offset 2.8m during the 1906 earthquake. We interpret the debris flow sediments to represent the last phase of deposition prior to abandonment of the old channel. We collected samples for radiocarbon dating, optically stimulated

  4. Cenozoic epeirogeny of the Arabian Peninsula from drainage modeling

    NASA Astrophysics Data System (ADS)

    Wilson, J. W. P.; Roberts, G. G.; Hoggard, M. J.; White, N. J.

    2014-10-01

    is generally accepted that the Arabian Peninsula has been uplifted by subcrustal processes. Positive residual depth anomalies from oceanic crust in the Red Sea and in the Gulf of Aden suggest that a region surrounding this peninsula is dynamically supported. Admittance calculations, surface wave tomography studies, and receiver function analyses all imply that regional topography is generated and maintained by some combination of mantle convective circulation and lithospheric thickness changes. Despite these significant advances, the spatial and temporal uplift rate history of the Arabian Peninsula is not well known. Here we show that a regional uplift rate history can be obtained by jointly inverting 225 longitudinal river profiles that drain this peninsula. Our strategy assumes that shapes of individual river profiles are controlled by uplift rate history and moderated by erosional processes. We used local measurements of incision rate to calibrate the relevant erosional parameters. In our inverse algorithm, uplift rate is permitted to vary smoothly as a function of space and time but upstream drainage area remains invariant. We also assume that knickzone migration is not lithologically controlled. Implications of these important assumptions have been investigated. Our results suggest that the Arabian Peninsula underwent two phases of asymmetric uplift during the last 20-30 Ma at rates of 0.05-0.1 mm a-1. The southwestern flank of the peninsula has been uplifted by 1.5-2.5 km. Regional stratigraphic constraints, the age and composition of volcanism, paleosol formation, incised peneplains, emergent marine terraces, and thermochronometric measurements corroborate our calculated patterns of uplift. Progressive development of three domal swells along the western margin of the peninsula is consistent with localized upwelling of hot asthenospheric mantle.

  5. Ground-water availability on the Kitsap Peninsula, Washington

    USGS Publications Warehouse

    Hansen, Arnold J.; Bolke, E.L.

    1980-01-01

    Unconsolidated deposits on the Kitsap Peninsula, Wash., are of glacial and interglacial origin. These deposits were divided into three units based on lithology and hydraulic properties. Two of the three units are composed of layers of sand and gravel , and silt and clay. The third unit consists of silt and clay and in most places separates the other two units. Water-bearing strata in the upper unit are fairly continuous and average 15 feet in thickness. The lower water-bearing strata are not believed to be as continuous as those in the upper unit, but yield larger quantities of water to wells. The silt-and-clay unit averages 70 feet in thickness, occurs generally near sea level, and is not known to contain major water-bearing deposits. The average annual ground-water recharge to streams on the Kitsap Peninsula was estimated to be 17 times the 1975 annual ground-water pumpage for the peninsula. Some, but an unknown amount, of this water is available for increased withdrawal by wells. Increased withdrawals cause decreased streamflow, declining water levels, and increased seawater contamination. There appears to be no widespread seawater contamination of wells in the study area. Local areas where chloride concentrations from wells exceed 25 milligrams per liter are near the southern part of the Longbranch Peninsula, Horsehead Bay, Point Evans, Sinclair Inlet, Eagle Harbor, Fletcher Bay, the northern end of Bainbridge Island, and the northern tip of the Kitsap Peninsula. (USGS)

  6. Winter precipitation variability over Korean Peninsula associated with ENSO

    NASA Astrophysics Data System (ADS)

    Son, Hye-Young; Park, Jong-Yeon; Kug, Jong-Seong; Yoo, Jinho; Kim, Cheol-Hee

    2014-06-01

    In this study, winter precipitation variability associated with the El Niño-Southern Oscillation (ENSO) over the Korean Peninsula was investigated using a 5-pentad running mean data because significant correlation pattern cannot be revealed using seasonal-mean data. It was found a considerably significant positive correlation between Niño3 sea-surface temperature and precipitation during early winter (from Mid-November to early-December), when the correlation coefficient is close to 0.8 in early-December; the correlation is distinctively weakened during late winter. It is demonstrated that such sudden intraseasonal change in relation to ENSO is associated with the presence of anticyclonic flow over the Kuroshio extension region (Kuroshio anticyclone). In early winter, there is strong southerly wind over the Korean Peninsula, which is induced by the Philippine Sea anticyclone and Kuroshio anticyclone. However, in January, although the Philippine Sea anticyclone develops further, the Kuroshio anticyclone suddenly disappears; as a result, the impact of ENSO is considerably weakened over the Korean Peninsula. These results indicate that the Kuroshio anticyclone during El Niño peak phase plays a critical role by strongly affecting Northeast Asia climate, including the Korean Peninsula. In addition, it is also found that there are distinctive interdecadal changes of the relationship between ENSO and precipitation over the Korean Peninsula. In particular, the strong correlation in early winter is clearer in the recent 30 years than that in the previous period of 1950-1979.

  7. Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

    USGS Publications Warehouse

    Back, W.; Lesser, J.M.

    1981-01-01

    Two critical objectives of water management in the Yucatan are: (1) to develop regional groundwater supplies for an expanding population and tourism based on the Mayan archeological sites and excellent beaches; and (2) to control groundwater pollution in a chemically sensitive system made vulnerable by geologic conditions. The Yucatan peninsula is a coastal plain underlain by permeable limestone and has an annual rainfall of more than 1000 mm. Such a setting should provide abundant supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that decrease the amount of available fresh water. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed by extensive use of groundwater. The religion was water-oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supplies by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution resulting from the use of a sewage disposal well adjacent to each supply well. The modern phase of water management began in 1959 when the Secretari??a de Recursos Hidra??ulicos (S.R.H.) was charged with the responsibility for both scientific investigations and development programmes for water-supply and sewage-disposal systems for cities, villages and islands. ?? 1981.

  8. Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

    NASA Astrophysics Data System (ADS)

    Back, W.; Lesser, J. M.

    1981-05-01

    Two critical objectives of water management in the Yucatan are: (1) to develop regional groundwater supplies for an expanding population and tourism based on the Mayan archeological sites and excellent beaches; and (2) to control groundwater pollution in a chemically sensitive system made vulnerable by geologic conditions. The Yucatan peninsula is a coastal plain underlain by permeable limestone and has an annual rainfall of more than 1000 mm. Such a setting should provide abundant supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that decrease the amount of available fresh water. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed by extensive use of groundwater. The religion was water-oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supplies by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution resulting from the use of a sewage disposal well adjacent to each supply well. The modern phase of water management began in 1959 when the Secretaría de Recursos Hidráulicos (S.R.H.) was charged with the responsibility for both scientific investigations and development programmes for water-supply and sewage-disposal systems for cities, villages and islands.

  9. Nitrate in the Columbia Aquifer, central Delmarva Peninsula, Maryland

    USGS Publications Warehouse

    Bachman, L.J.

    1984-01-01

    A study of nitrate in water from 604 wells tapping the Columbia aquifer on the Delmarva Peninsula in eastern Maryland describes the factors that affect nitrate variability. Samples were collected from 196 randomly selected wells and analyzed for nitrogen species. Many were also analyzed for major ions. In addition, results of 313 nitrate analyses were randomly selected from county health department files. About 95 analyses of water samples collected from 1945 to 1978 were also evaluated. The frequency distribution of the nitrate analyses is bimodal, with 25 percent of the sample ranging from 0 to about 0.42 milligrams per liter (mg/L) nitrate as nitrogen (N), and the median is about 0.1 mg/L; the rest ranges from 0.42 to 58 mg/L, and the median is about 5.9 mg/L. The overall median nitrate concentration is about 3.5 mg/L as N. Over half of the samples had nitrate concentrations of 3 mg/L as N or higher, indicating that the water in the aquifer has been affected by human activity. Nitrate-nitrogen concentrations exceeded the water-quality standard of 10 mg/L in 15 percent of the samples established by the U.S. Environmental Protection Agency. The major factors affecting nitrate concentration are the presence of a nitrogen source, hydrogeological conditions, and the soil drainage. Sites with poorly drained soils may have a lower nitrate concentration either because the soils block the entrance of nitrate into the aquifer or because the aquifer under a poorly drained soil is associated with a chemical environment that promotes denitrification. (USGS)

  10. Groundwater temperature transients on the Armutlu peninsula, eastern Marmara region

    NASA Astrophysics Data System (ADS)

    Woith, Heiko; Caka, Deniz; Seyis, Cemil; Italiano, Francesco; Celik, Cengiz; Wang, Rongjiang; Baris, Serif

    2016-04-01

    Since many years MAM and GFZ in co-operation with Kocaeli University (KU) operate fluid monitoring stations around the Sea of Marmara. In the frame of MARsite (MARsite has received funding from the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 308417) these networks were jointly evaluated for the first time. The on-land fluid monitoring networks continuously monitor the following parameters: soil radon (21 sites), temperature and conductivity of thermal springs (9 sites) operated by MAM covering the whole Marmara region; fluid pressure and water level/temperature (8 sites) within ARNET operated by GFZ/KU. ARNET is a combined seismological/hydrogeological monitoring network covering the Armutlu peninsula located SE of Istanbul. Additional to the geothermal wells and springs - our main target to detect transients of potentially seismo-tectonic origin - three shallow groundwater wells (tenth of meters deep) are being operated to identify and quantify seasonal variations, and meteorological influences like rainfall and snowmelt. But it turned out that these shallow aquifer systems showed very stable conditions with very small annual temperature amplitudes (0.2 - 0.3°C). One of these shallow monitoring wells is located just south of Lake Iznik (in the village of Sölöz) very close to the southern branch of the North Anatolian Fault Zone. Water level showed a steady decreasing trend since June 2012. This trend resulted in a data gap starting in January 2014, when the water level dropped below the sensor position. After adjusting the sensor position, positive spikes in the borehole temperature were recorded in June and August 2014, and again in 2015. The spikes are characterised by a sharp temperature increase followed by a decay lasting several days until the pre-event temperature was reached again. Since the spikes occurred on two independent logger systems, and since they lasted several days, a

  11. Ocean Drilling Program Leg 178 (Antarctic Peninsula): Sedimentology of glacially influenced continental margin topsets and foresets

    USGS Publications Warehouse

    Eyles, N.; Daniels, J.; Osterman, L.E.; Januszczak, N.

    2001-01-01

    Ocean Drilling Program Leg 178 (February-April 1998) drilled two sites (Sites 1097 and 1103) on the outer Antarctic Peninsula Pacific continental shelf. Recovered strata are no older than late Miocene or early Pliocene (<4.6 Ma). Recovery at shallow depths in loosely consolidated and iceberg-turbated bouldery sediment was poor but improved with increasing depth and consolidation to allow description of lithofacies and biofacies and interpretation of depositional environment. Site 1097 lies on the outer shelf within Marguerite Trough which is a major outlet for ice expanding seaward from the Antarctic Peninsula and reached a maximum depth drilled of 436.6 m below the sea floor (mbsf). Seismic stratigraphic data show flat-lying upper strata resting on strata that dip gently seaward. Uppermost strata, to a depth of 150 mbsf, were poorly recovered, but data suggest they consist of diamictites containing reworked and abraded marine microfauna. This interval is interpreted as having been deposited largely as till produced by subglacial cannibalization of marine sediments (deformation till) recording ice sheet expansion across the shelf. Underlying gently dipping strata show massive, stratified and graded diamictite facies with common bioturbation and slump stuctures that are interbedded with laminated and massive mudstones with dropstones. The succession contains a well-preserved in situ marine microfauna typical of open marine and proglacial marine environments. The lower gently dipping succession at Site 1097 is interpreted as a complex of sediment gravity flows formed of poorly sorted glacial debris. Site 1103 was drilled in that part of the continental margin that shows uppermost flat-lying continental shelf topsets overlying steeper dipping slope foresets seaward of a structural mid-shelf high. Drilling reached a depth of 363 mbsf with good recovery in steeply dipping continental slope foreset strata. Foreset strata are dominated by massive and chaotically

  12. Volcanic Facies of the Lower Jurassic Talkeetna Formation, Iniskin Peninsula to Tuxedni Bay, Alaska Peninsula

    NASA Astrophysics Data System (ADS)

    Bull, K. F.

    2015-12-01

    The Lower Jurassic Talkeetna Formation (Jtk), a >1,000-km-long belt of vol­canic facies within the accreted intra-oceanic Talkeetna Arc has been characterized within the Talkeetna Mountains, but on the Alaska Peninsula Jtk facies have not previously been described in detail. Here we describe facies of the Jtk stretching from the Iniskin Peninsula to Tuxedni Bay. On the Iniskin Peninsula, a high concentration and great thickness of mafic to intermediate lavas, associated autobreccias and hyaloclastites, fluidal-clast breccias and possible pillows are suggestive of one or more submarine effusive eruption centers. Also volumetrically significant are non-stratified polymictic volcaniclastic breccia facies. Minor facies include thinly bedded volcaniclastic sandstone to pebble breccia-conglomerate facies, some of which are shard- and pumice-bearing pyroclastic deposits preserved in thinly bedded deposits, indicative of episodes of explosive volcanism and the eruption-fed nature of some of the deposits. North of Chinitna Bay, coherent facies tend to be thin and relatively small in volume. Volcaniclastic facies provide evidence of subaerial-fluvial deposition, and pyroclastic activity. Thinly bedded, laterally continuous beds locally exhibit cross-laminations, channel fills, normal grading and lenticular beds, and contain plant fossils. Within this sequence is a 10-m-thick pumice breccia containing fossilized logs, underlain by a thin, weakly laminated, pumice- and lithic-bearing volcaniclastic siltstone to sandstone. The log-bearing pumice breccia and the lithic-bearing laminated basal unit represent pyroclastic density current (PDC) facies deposited in a subaerial or possibly shallow aqueous environment. Underlying the PDC deposit are several 30-cm-thick maroon and olive green volcaniclastic fine-grained sandstone and siltstone beds containing channel fills, cross-beds and lenticular beds. Marbles exposed in the contact zone between the intrusions of Alaska

  13. Alaska peninsula stable isotope and radioisotope chemistry: a study in temporal and adaptive diversity.

    PubMed

    Coltrain, Joan Brenner

    2010-12-01

    Purified bone collagen from a small suite of human remains recovered at three sites on the Alaska Peninsula (Port Moller, Brooks River, and Mink Island) were analyzed for stable carbon and nitrogen isotope chemistry and were accelerator radiocarbon dated. Because samples sizes were small and faunal isotope chemistry lacking, results should be considered preliminary. However, these data indicate that each locality was represented by a somewhat different suite of subsistence strategies and covered a distinct temporal span. Port Moller burials (n = 7) from the Hot Springs site date to a calibrated 2σ range of 3547-1388 BP. Although marine foods clearly made the greatest contribution to these diets, individuals were not as heavily reliant on high-trophic-level marine taxa as eastern Aleutian groups to the west, given their intake of salmon and evidence of caribou hunting. Brooks River burials (n = 9) expressed an inland foraging focus with significant reliance on caribou and spawning salmon and covered a calibrated 2σ range of 1484-381 BP. In contrast, individuals from Mink Island (n = 7), dating to cal. 666-292 BP, were heavily reliant on high-trophic-level marine prey similar to but not as enriched isotopically as the Aleut, perhaps a consequence of limited access to caribou and greater reliance on invertebrates. This pattern suggests that prehistoric economic strategies on the Alaska Peninsula were diverse, characterized by fine-tuned adaptations to local ecological settings, perhaps mediated by ethnic factors and territorial and social pressures.

  14. Rhizobium anhuiense as the predominant microsymbionts of Lathyrus maritimus along the Shandong Peninsula seashore line.

    PubMed

    Li, Yan; Wang, En Tao; Liu, Yajing; Li, Xiangyue; Yu, Bing; Ren, Chenggang; Liu, Wei; Li, Yunzhao; Xie, Zhihong

    2016-09-01

    Beach pea [Lathyrus maritimus Bigelow, or Lathyrus japonicus subsp. maritimus (L.) P.W. Ball] is a wild legume distributed on the seashore line, and the rhizobia nodulating with this plant have been reported only rarely. In order to reveal the diversity of beach pea rhizobia on the seashore line of Shandong Peninsula, China, a total of 124 bacterial strains were isolated from the root nodules of beach pea plants collected from five sites. All the isolates were divided into five recA types after screening by recA gene sequence analysis and they consisted of Rhizobium anhuiense covering 122 symbiotic isolates in three recA types, as well as two single isolates Rhizobium sp. and Rhizobium lusitanum representing distinct recA types. The recA genotype III of R. anhuiense (103 isolates) represented by strain YIC11270 was dominant at all five sampling sites. Identical symbiotic genes (nodC and nifH) were detected in the three recA genotypes of R. anhuiense isolates that were closely related to those of the pea and faba rhizobia. This study clarified that R. anhuiense was the main symbiont for beach pea rhizobia on the seashore line of Shandong Peninsula. The low level genetic diversity of beach pea rhizobia revealed by both MLSA and the symbiotic genes might be related to the strong selection pressure produced by the saline-alkaline environment and the host plants. PMID:27480059

  15. Composition and microstructure of Roman metallic artefacts of Southwestern Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Valério, P.; Voráčová, E.; Silva, R. J. C.; Araújo, M. F.; Soares, A. M. M.; Arruda, A. M.; Pereira, C.

    2015-10-01

    The Roman invasion introduces new alloys and metallurgical practices in Iberian Peninsula. The southwestern end of this region has many evidences of connections with the Roman World, but there are no studies about the manufacture and use of copper-based artefacts during this period. Therefore, a set of about 20 ornaments, tools and small attachments recovered at the Roman sites of Monte Molião and Cidade das Rosas was studied by an analytical approach combining micro-EDXRF, optical microscopy, SEM-EDS and Vickers microhardness testing. The artefact composition shows a good correlation with function, namely pure copper for nails and rivets, low-tin bronze (2-6 wt% Sn) for basic tools, high-tin bronze (14 wt% Sn) for fibulae and high-lead bronze (19 wt% Pb) for a decorated jug handle. The manufacture also depends on function because most artefacts were subjected to thermomechanical processing, except the ornaments that would not benefit from post-casting work. Brass and gunmetal were only present in the site with a later chronology. A metallurgy visibly ruled by economical, aesthetical and technological concerns reinforces the evidences about the total integration of Southwestern Iberian Peninsula in the Roman World, but further studies will be essential to determine the evolution of copper-based alloys in Lusitania under Roman influence.

  16. Paleomagnetism of Silver Island, Keweenaw Peninsula, Michigan: Additional Support (?) for the Primary Curvature of the MCR

    NASA Astrophysics Data System (ADS)

    Diehl, J. F.; Durant, A. J.; Schepke, C.

    2009-05-01

    Silver Island lies between Eagle Harbor and Copper Harbor on the NW coastline of the Keweenaw Peninsula, Michigan. The island consists of a series of basaltic lava flows which dip to the north-northwest (356°) at an angle of approximately 38°. These flows constitute part of the Lake Shore Traps (LST), a series of interbedded lava flows within the Copper Harbor Conglomerate (CHC). The LST represent the youngest eruptive material associated with the 1.1 Ga Mid-Continent Rift (MCR). The most recent paleomagnetic study (now 15 years old) on the Lakeshore Traps (LST) defined three distinct directional clusters. Each cluster of directions corresponded to a different stratigraphic package of the LST within the CHC and all have extremely low between-site dispersion (s ˜ 4°) suggesting rather rapid emplacement of the LST packages. Consequently, each cluster has its own unique direction of magnetization. Since the lower two LST packages crop out along the coast line of the Peninsula with different structural trends, an opportunity was presented to test the conclusions of Hnat et al. (2006) that the curvature of the MCR was primary. To that end nine lava flows were sampled on Silver Island and their mean direction compared to the equivalent mean from lava flows sampled by Diehl and Haig (1994) from the tip of the Keweenaw Peninsula (upper lava flows of the Middle LST) which have an entirely different structural trend. Characteristic directions of magnetization of the Silver Island lava flows were isolated either using alternating field, thermal or a combination of both. The mean direction of magnetization for the nine sites is: D = 277.7°, I = 46.9°, α95 = 3.0°, k = 292.5. The mean direction recalculated from the Diehl and Haig study is: D = 277.8°, I = 40.6°, α95 = 2.9°, k = 315.7. Although the declinations of the two means are identical, interestingly the two means are statistically distinct at the 95% confidence level. Fold tests were inconclusive. Nevertheless

  17. Paleomagnetism of early Tertiary Alaska Peninsula rocks and implications for docking of peninsular terrane

    SciTech Connect

    Whitney, J.W.; Levinson, R.A.; Van Alstine, D.R.

    1985-04-01

    In order to refine the tectonic history of the peninsular terrane, Alaska, 22 sites (averaging 10 samples/site) in Paleogene Tertiary volcanic and sedimentary formations were sampled in the vicinity of Chignik, on the Pacific side of the Alaska Peninsula. Ten of the sites were drilled in the early Oligocene Meshik volcanics, ranging from andesite to basalt, and the other twelve sites were drilled in the late Eocene Tolstoi Formation sediments. Nine of the volcanic sites yielded stable R and/or N characteristic magnetization. Virtually no fine-grained, interbedded sediments occur with the Meshik volcanics at the sample sites, thus making reliable paleohorizontal determinations difficult. Although flow attitudes were tentatively used, it became rapidly apparent that problems of initial dip were insurmountable. As a result, all volcanic sites were considered unreliable for determining a meaningful paleomagnetic inclination. Upon thermal demagnetization, five of the sedimentary sites were judged stable. The mode of the paleomagnetic direction was calculated, D/I = 349.8/75.3(..beta..95 = 8.5), indicating no significant rotation. Uncertainties in structural corrections, however, may render only the inclination meaningful, which, from McFadden statistics yields, I = 75.9, ..cap alpha..95 = 7.9, corresponding to a paleolatitude of 63.3/sup 0/. This paleolatitude agrees with the expected value for the North American craton at 40 m.y. B.P., implying that the peninsular terrane had docked at at least that time.

  18. Tectonic, Climatic, and Cryospheric Evolution of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-06-01

    For millennia, Antarctica has been a frozen continent, a land of ice and snow where complex life persists rather than thrives. But Antarctica has not always been this way. Millions of years ago the southern continent was teeming with life. Changing oceans and a plummeting atmospheric carbon dioxide concentration drove a dramatic evolution of the Antarctic continent. To provide a record of these ancient climatic shifts, the 2005-2006 SHALDRIL drilling program collected sediment cores from the bed of the iceberg-filled seas off the Antarctic Peninsula. In the AGU book Tectonic, Climatic, and Cryospheric Evolution of the Antarctic Peninsula, editors John B. Anderson and Julia S. Wellner draw on the findings garnered from SHALDRIL to explore the changing Antarctic Peninsula. In this interview, Eos talks to John B. Anderson.

  19. Pteropods and climate off the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Loeb, Valerie J.; Santora, Jarrod A.

    2013-09-01

    Shelled (thecosome) and naked (gymnosome) pteropods are regular, at times abundant, members of Southern Ocean zooplankton assemblages. Regionally, shelled species can play a major role in food webs and carbon cycling. Because of their aragonite shells thecosome pteropods may be vulnerable to the impacts of ocean acidification; without shells they cannot survive and their demise would have major implications for food webs and carbon cycling in the Southern Ocean. Additionally, pteropod species in the southwest Atlantic sector of the Southern Ocean inhabit a region of rapid warming and climate change, the impacts of which are predicted to be observed as poleward distribution shifts. Here we provide baseline information on intraseasonal, interannual and longer scale variability of pteropod populations off the Antarctic Peninsula between 1994 and 2009. Concentrations of the 4 dominant taxa, Limacina helicina antarctica f. antarctica, Clio pyramidata f. sulcata, Spongiobranchaea australis and Clione limacina antarctica, are similar to those monitored during the 1928-1935 Discovery Investigations and reflect generally low values but with episodic interannual abundance peaks that, except for C. pyr. sulcata, are related to basin-scale climate forcing associated with the El Niño-Southern Oscillation (ENSO) climate mode. Significant abundance increases of L. helicina and S. australis after 1998 were associated with a climate regime shift that initiated a period dominated by cool La Niña conditions and increased nearshore influence of the Antarctic Circumpolar Current (ACC). This background information is essential to assess potential future changes in pteropod species distribution and abundance associated with ocean warming and acidification. construct maps of pteropod spatial frequency and mean abundance to assess their oceanographic associations; quantify pteropod abundance anomalies for comparing intraseasonal and interannual variability relative to m-3 environmental

  20. Anaglyph with Landsat Overlay, Kamchatka Peninsula, Russia

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This 3-D anaglyph shows an area on the western side of the volcanically active Kamchatka Peninsula, Russia. Red-blue glasses are required to see the 3-D effect. The topographic data are from the first C-band mapping swath of the Shuttle Radar Topography Mission (SRTM). Images from the optical Landsat satellite are overlain on the SRTM topography data. The meandering channel of the Tigil River is seen along the bottom of the image, at the base of steep cliffs. In the middle left of the image, a terrace indicates recent uplift of the terrain and downcutting by the river. High resolution SRTM topographic data will be used by geologists and hydrologists to study the interplay of tectonic uplift and erosion.

    This anaglyph was generated using topographic data from the Shuttle Radar Topography Mission to create two differing perspectives of a single image, one perspective for each eye. Each point in the image is shifted slightly, depending on its elevation. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. The United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota, provided the Landsat data, which are overlain on the topography.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA

  1. Interactions Between Islamic and Christian Traditions in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    González-García, A. César; Belmonte, Juan Antonio

    Pre-Romanesque churches in the Iberian Peninsula include a number of constructions from the fourth-fifth to the eleventh century when the first Romanesque churches appeared in the north of Spain. This period of time coincided with the Muslim invasion of the Peninsula. An important number of churches and mosques were built with prescriptions for the orientation, which possibly included astronomical observations. Investigations show that both groups of monuments reacted by avoiding the areas of theoretical influence of the other religion while trying to obey their own orientation rules.

  2. Water Quality in the Delmarva Peninsula, Delaware, Maryland, and Virginia, 1999-2001

    USGS Publications Warehouse

    Denver, Judith M.; Ator, Scott W.; Debrewer, Linda M.; Ferrari, Matthew J.; Barbaro, Jeffrey R.; Hancock, Tracy C.; Brayton, Michael J.; Nardi, Mark R.

    2004-01-01

    This report contains the major findings of a 1999-2001 assessment of water quality in the Delmarva Peninsula. It is one of a series of reports by the National Water-Quality Assessment (NAWQA) Program that present major findings in 51 major river basins and aquifer systems across the Nation. In these reports, water quality is assessed at many scales?from local ground-water flow paths to regional ground-water networks and in surface water?and is discussed in terms of local, State, and regional issues. Conditions in the Delmarva Peninsula are compared to conditions found elsewhere and to selected national benchmarks, such as those for drinking-water quality and the protection of aquatic organisms. This report is intended for individuals working with water-resource issues in Federal, State, or local agencies; universities; public interest groups; or in the private sector. The information will be useful in addressing a number of current issues, such as the effects of agricultural and urban land use on water quality, human health, drinking water, source-water protection, hypoxia and excessive growth of algae and plants, pesticide registration, and monitoring and sampling strategies. This report is also for individuals who wish to know more about the quality of streams and ground water in areas near where they live, and how that water quality compares to the quality of water in other areas across the Nation. Other products describing water-quality conditions in the Delmarva Peninsula are available. Detailed technical information, data and analyses, methodology, models, graphs, and maps that support the findings presented in this report can be accessed from http://md.water.usgs.gov/delmarva. Other reports in this series and data collected from other basins can be accessed from the national NAWQA Web site (http://water.usgs.gov/nawqa).

  3. Geology and timing of mineralization at the Cangshang gold deposit, north-western Jiaodong Peninsula, China

    USGS Publications Warehouse

    Zhang, X.; Cawood, Peter A.; Wilde, S.A.; Liu, R.; Song, H.; Li, W.; Snee, L.W.

    2003-01-01

    The Cangshang gold deposit of the northwestern Jiaodong Peninsula contains reserves of greater than 50 tonnes (t) and is developed by the largest open pit gold mine in China. This deposit is a Jiaojia-style (i.e. disseminated-and-veinlet) deposit. It is controlled by the San-Cang fault zone, which trends ???040?? and dips 40-75??SE at the mine site. The main (no. 1) orebody lies between a hanging wall of Precambrian metamorphic rocks (mainly amphibolite) of the Fenzishan Group and a footwall composed of the Mesozoic Linglong granitoid. The ore zone is mainly composed of pyritized, sericitized and silicified granitoid, which has undergone variable degrees of cataclasis. SHRIMP U-Pb dating of zircon indicates that the protolith of the hanging wall amphibolite was formed at 2530 ?? 17 Ma and underwent metamorphism at 1852 ?? 37 Ma. The footwall granodiorite has been dated at 166 ?? 4 Ma, whereas zircons from the ore zone yield a younger age of 154 ?? 5 Ma. Cathodoluminescence images of zircons from the granodiorite and ore zone show oscillatory zonation indicative of an igneous origin for both and the ages of these zircons, therefore, are all interpreted to be representative of magmatic crystallization. Dating of sericite by 40Ar-39Ar has been used to directly determine the timing of formation of the Cangshang deposit, providing the first time absolute age on formation of the Jiaojia-style gold deposits. The well-defined age of 121.3 ?? 0.2 Ma provides the precise timing of gold mineralization at the Cangshang deposit. This age is consistent with those of Linglong-style (vein type) gold mineralization, also from the north-western Jiaodong Peninsula, at between 126 and 120 Ma. Therefore, our work indicates that both styles of gold deposits in the Jiaodong Peninsula were formed during the same mineralization event.

  4. Paleoclimate and Paleoenvironmental Reconstructions on the North Kola Peninsula during the Past 2000 Years According Pollen Data

    NASA Astrophysics Data System (ADS)

    Nosevich, Ekaterina; Sapelko, Tatjana; Anisimov, Mikhail

    2014-05-01

    Pollen data and radiocarbon data have enabled to reconstruct the periods of vegetation that depended on the climate changes. Records from different types of deposits allow to receive more information and to make paleoclimate reconstructions. Lake and bog sediments are the best sources for palaeoreconstruction. Palaeoclimatic changes, tectonic and coastline movement during Late Holocene caused vegetation changes on the North Kola Peninsula. Our data from pollen records from different sites on the north coast of the Kola Peninsula covers the Late Holocene about last 2000 years. We studied different types of sediment cores in the area between 69° N and 70° N, 31°12' E and 35° E. We have studied peat deposits, small lake sediments and archaeological site on the Bolshoy Oleniy Island in Kola fjord, Barents Sea, and peat bog deposits in the Teriberka area. All the cores are studied by different methods where the core was pollen analysis. It has allowed tracking the periods of vegetation history in the tundra zone. Pollen reconstructions are confirmed by radiocarbon data. Our data was compared with other researches and we made correlations between pollen records from different lake deposits. Modern vegetation presents south tundra type of associations. Teriberka area is unique: almost existing types of tundra landscapes are presented here in small territory, including "typical tundra" with subshrubs formations. For paleoclimate reconstructions we have studied surface samples by pollen analysis. Samples were collected in 3 regions of Kola Peninsula. Samples have been taken on the Sredniy and Rybachiy Peninsulas (Murman region) in the south tundra with rich associations and boreal species of herbs. In the Olenegorsk region we selected vegetation associations not damaged by human and we collected surface samples on the border of forest tundra and northern taiga. In Apatity region we studied pollen records in North taiga landscapes. This data characterize regional and

  5. Trends of Rural Tropospheric Ozone at the Northwest of the Iberian Peninsula

    PubMed Central

    Saavedra, S.; Rodríguez, A.; Souto, J. A.; Casares, J. J.; Bermúdez, J. L.; Soto, B.

    2012-01-01

    Tropospheric ozone levels around urban and suburban areas at Europe and North America had increased during 80's–90's, until the application of NOx reduction strategies. However, as it was expected, this ozone depletion was not proportional to the emissions reduction. On the other hand, rural ozone levels show different trends, with peaks reduction and average increments; this different evolution could be explained by either emission changes or climate variability in a region. In this work, trends of tropospheric ozone episodes at rural sites in the northwest of the Iberian Peninsula were analyzed and compared to others observed in different regions of the Atlantic European coast. Special interest was focused on the air quality sites characterization, in order to guarantee their rural character in terms of air quality. Both episodic local meteorological and air quality measurements along five years were considered, in order to study possible meteorological influences in ozone levels, different to other European Atlantic regions. PMID:22649298

  6. 46 CFR 7.165 - Kenai Peninsula, AK to Kodiak Island, AK.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Kenai Peninsula, AK to Kodiak Island, AK. 7.165 Section... BOUNDARY LINES Alaska § 7.165 Kenai Peninsula, AK to Kodiak Island, AK. (a) A line drawn from the southernmost extremity of Kenai Peninsula at longitude 151°44.0′ W. to East Amatuli Island Light; thence to...

  7. 46 CFR 7.165 - Kenai Peninsula, AK to Kodiak Island, AK.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Kenai Peninsula, AK to Kodiak Island, AK. 7.165 Section... BOUNDARY LINES Alaska § 7.165 Kenai Peninsula, AK to Kodiak Island, AK. (a) A line drawn from the southernmost extremity of Kenai Peninsula at longitude 151°44.0′ W. to East Amatuli Island Light; thence to...

  8. 46 CFR 7.165 - Kenai Peninsula, AK to Kodiak Island, AK.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Kenai Peninsula, AK to Kodiak Island, AK. 7.165 Section... BOUNDARY LINES Alaska § 7.165 Kenai Peninsula, AK to Kodiak Island, AK. (a) A line drawn from the southernmost extremity of Kenai Peninsula at longitude 151°44.0′ W. to East Amatuli Island Light; thence to...

  9. 46 CFR 7.165 - Kenai Peninsula, AK to Kodiak Island, AK.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Kenai Peninsula, AK to Kodiak Island, AK. 7.165 Section... BOUNDARY LINES Alaska § 7.165 Kenai Peninsula, AK to Kodiak Island, AK. (a) A line drawn from the southernmost extremity of Kenai Peninsula at longitude 151°44.0′ W. to East Amatuli Island Light; thence to...

  10. 46 CFR 7.165 - Kenai Peninsula, AK to Kodiak Island, AK.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Kenai Peninsula, AK to Kodiak Island, AK. 7.165 Section... BOUNDARY LINES Alaska § 7.165 Kenai Peninsula, AK to Kodiak Island, AK. (a) A line drawn from the southernmost extremity of Kenai Peninsula at longitude 151°44.0′ W. to East Amatuli Island Light; thence to...

  11. Probabilistic seismic hazard analysis for Sumatra, Indonesia and across the Southern Malaysian Peninsula

    USGS Publications Warehouse

    Petersen, M.D.; Dewey, J.; Hartzell, S.; Mueller, C.; Harmsen, S.; Frankel, A.D.; Rukstales, K.

    2004-01-01

    The ground motion hazard for Sumatra and the Malaysian peninsula is calculated in a probabilistic framework, using procedures developed for the US National Seismic Hazard Maps. We constructed regional earthquake source models and used standard published and modified attenuation equations to calculate peak ground acceleration at 2% and 10% probability of exceedance in 50 years for rock site conditions. We developed or modified earthquake catalogs and declustered these catalogs to include only independent earthquakes. The resulting catalogs were used to define four source zones that characterize earthquakes in four tectonic environments: subduction zone interface earthquakes, subduction zone deep intraslab earthquakes, strike-slip transform earthquakes, and intraplate earthquakes. The recurrence rates and sizes of historical earthquakes on known faults and across zones were also determined from this modified catalog. In addition to the source zones, our seismic source model considers two major faults that are known historically to generate large earthquakes: the Sumatran subduction zone and the Sumatran transform fault. Several published studies were used to describe earthquakes along these faults during historical and pre-historical time, as well as to identify segmentation models of faults. Peak horizontal ground accelerations were calculated using ground motion prediction relations that were developed from seismic data obtained from the crustal interplate environment, crustal intraplate environment, along the subduction zone interface, and from deep intraslab earthquakes. Most of these relations, however, have not been developed for large distances that are needed for calculating the hazard across the Malaysian peninsula, and none were developed for earthquake ground motions generated in an interplate tectonic environment that are propagated into an intraplate tectonic environment. For the interplate and intraplate crustal earthquakes, we have applied ground

  12. 27 CFR 9.114 - Old Mission Peninsula.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.114 Old Mission Peninsula. (a) Name. The name of the viticultural area described in this section is “Old... Mission Peninsula” viticultural area are 2 U.S.G.S. Quadrangle (15 Minute Series) maps, scaled at...

  13. 27 CFR 9.114 - Old Mission Peninsula.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.114 Old Mission Peninsula. (a) Name. The name of the viticultural area described in this section is “Old... Mission Peninsula” viticultural area are 2 U.S.G.S. Quadrangle (15 Minute Series) maps, scaled at...

  14. 27 CFR 9.114 - Old Mission Peninsula.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.114 Old Mission Peninsula. (a) Name. The name of the viticultural area described in this section is “Old... Mission Peninsula” viticultural area are 2 U.S.G.S. Quadrangle (15 Minute Series) maps, scaled at...

  15. 27 CFR 9.114 - Old Mission Peninsula.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.114 Old Mission Peninsula. (a) Name. The name of the viticultural area described in this section is “Old... Mission Peninsula” viticultural area are 2 U.S.G.S. Quadrangle (15 Minute Series) maps, scaled at...

  16. 27 CFR 9.114 - Old Mission Peninsula.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.114 Old Mission Peninsula. (a) Name. The name of the viticultural area described in this section is “Old... Mission Peninsula” viticultural area are 2 U.S.G.S. Quadrangle (15 Minute Series) maps, scaled at...

  17. 48. Photocopy of photograph (from Reflections, Peninsula Transportation District Commission, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. Photocopy of photograph (from Reflections, Peninsula Transportation District Commission, 1985. Original three CRT buses in 1928. *FOR Photocopy of photograph (from the Charles H. Taylor Memorial Library), photographer unknown. Trolley car No. 315 shown April 25, 1929 at the Trolley Barn. SEE FIELD NOTES - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  18. 46. Photocopy of photograph (Pentran file), (from Alexander Brown's Peninsula's ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. Photocopy of photograph (Pentran file), (from Alexander Brown's Peninsula's Last Street Cars, Daily Press, January 15, 1956) photographer unknown. The first streetcar (with dignitaries) to make the run from Newport News to a new housing development named Hilton Village in September 1918. - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  19. A Sketch of Language History in the Korean Peninsula

    PubMed Central

    Lee, Sean

    2015-01-01

    Among 7100 languages spoken on Earth, the Koreanic language is the 13th largest, with about 77 million speakers in and around the Korean Peninsula. In comparison to other languages of similar size, however, surprisingly little is known about the evolution of the Koreanic language. This is mainly due to two reasons. The first reason is that the genealogical relationship of the Koreanic to other neighboring languages remains uncertain, and thus inference from the linguistic comparative method provides only provisional evidence. The second reason is that, as the ancestral Koreanic speakers lacked their own writing system until around 500 years ago, there are scant historical materials to peer into the past, except for those preserved in Sinitic characters that we have no straightforward way of interpreting. Here I attempt to overcome these disadvantages and shed some light on the linguistic history of the Korean Peninsula, by analyzing the internal variation of the Koreanic language with methods adopted from evolutionary biology. The preliminary results presented here suggest that the evolutionary history of the Koreanic language is characterized by a weak hierarchical structure, and intensive gene/culture flows within the Korean Peninsula seem to have promoted linguistic homogeneity among the Koreanic variants. Despite the gene/culture flows, however, there are still three detectable linguistic barriers in the Korean Peninsula that appear to have been shaped by geographical features such as mountains, elevated areas, and ocean. I discuss these findings in an inclusive manner to lay the groundwork for future studies. PMID:26024377

  20. Phosphorus leaching from agricultural soils of the Delmarva Peninsula, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaching of phosphorus (P) mobilizes edaphic and applied sources of P and is a primary pathway of concern in agricultural soils of the Delmarva Peninsula, which defines the eastern boundary of the eutrophic Chesapeake Bay. We evaluated P leaching before and after poultry litter application from inta...

  1. Drought variability and change across the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Coll, J. R.; Aguilar, E.; Ashcroft, L.

    2016-09-01

    Drought variability and change was assessed across the Iberian Peninsula over more than 100 years expanding through the twentieth century and the first decade of the twenty-first century. Daily temperature and precipitation data from 24 Iberian time series were quality controlled and homogenized to create the Monthly Iberian Temperature and Precipitation Series (MITPS) for the period 1906-2010. The Standardized Precipitation Index (SPI), driven only by precipitation, and the Standardized Precipitation Evapotranspiration Index (SPEI), based on the difference between the precipitation and the reference evapotranspiration (ET0), were computed at annual and seasonal scale to describe the evolution of droughts across time. The results confirmed that a clear temperature increase has occurred over the entire Iberian Peninsula at the annual and seasonal scale, but no significant changes in precipitation accumulated amounts were found. Similar drought variability was provided by the SPI and SPEI, although the SPEI showed greater drought severity and larger surface area affected by drought than SPI from 1980s to 2010 due to the increase in atmospheric evaporative demand caused by increased temperatures. Moreover, a clear drying trend was found by the SPEI for most of the Iberian Peninsula at annual scale and also for spring and summer, although the SPI did not experience significant changes in drought conditions. From the drying trend identified for most of the Iberian Peninsula along the twentieth century, an increase in drought conditions can also be expected for this region in the twenty-first century according to future climate change projections and scenarios.

  2. A sketch of language history in the Korean Peninsula.

    PubMed

    Lee, Sean

    2015-01-01

    Among 7100 languages spoken on Earth, the Koreanic language is the 13th largest, with about 77 million speakers in and around the Korean Peninsula. In comparison to other languages of similar size, however, surprisingly little is known about the evolution of the Koreanic language. This is mainly due to two reasons. The first reason is that the genealogical relationship of the Koreanic to other neighboring languages remains uncertain, and thus inference from the linguistic comparative method provides only provisional evidence. The second reason is that, as the ancestral Koreanic speakers lacked their own writing system until around 500 years ago, there are scant historical materials to peer into the past, except for those preserved in Sinitic characters that we have no straightforward way of interpreting. Here I attempt to overcome these disadvantages and shed some light on the linguistic history of the Korean Peninsula, by analyzing the internal variation of the Koreanic language with methods adopted from evolutionary biology. The preliminary results presented here suggest that the evolutionary history of the Koreanic language is characterized by a weak hierarchical structure, and intensive gene/culture flows within the Korean Peninsula seem to have promoted linguistic homogeneity among the Koreanic variants. Despite the gene/culture flows, however, there are still three detectable linguistic barriers in the Korean Peninsula that appear to have been shaped by geographical features such as mountains, elevated areas, and ocean. I discuss these findings in an inclusive manner to lay the groundwork for future studies.

  3. Pumas and Prepositions: Training Nature Guides in the Yucatan Peninsula.

    ERIC Educational Resources Information Center

    Brown, Cynthia

    2000-01-01

    In the Yucatan Peninsula (Mexico), the 10-week Nature Guide Training Program integrates English immersion with natural history and environmental interpretation to train rural adults as nature guides and conservation leaders. Most graduates have found work as ecotourism guides or in conservation-related activities, and many have provided English…

  4. Stable isotopes and Antarctic moss banks: Plants and soil microbes respond to recent warming on the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Royles, Jessica; Amesbury, Matthew; Ogée, Jérôme; Wingate, Lisa; Convey, Peter; Hodgson, Dominic; Griffiths, Howard; Leng, Melanie; Charman, Dan

    2014-05-01

    The Antarctic Peninsula is one of the most rapidly warming regions on Earth, with air temperature increases of as much as 3°C recorded since the 1950s. However, the longer-term context of this change is limited and existing records, largely relying on ice core data, are not suitably located to be able to trace the spatial signature of change over time. We are working on a project exploiting stable isotope records preserved in moss peat banks spanning 10 degrees of latitude along the Antarctic Peninsula as an archive of late Holocene climate variability. Here we present a unique time series of past moss growth and soil microbial activity that has been produced from a 150 year old moss bank at Lazarev Bay, Alexander Island (69°S), a site at the southern limit of significant plant growth in the Antarctic Peninsula region. These moss banks are ideal archives for palaeoclimate research as they are well-preserved by freezing, generally monospecific, easily dated by radiocarbon techniques, and have sufficiently high accumulation rates to permit decadal resolution. We use accumulation rates, cellulose δ13C and fossil testate amoebae to show that growth rates, assimilation and microbial productivity rose rapidly in the 1960s, consistent with temperature change, although recently may have stalled, concurrent with other evidence. The increase in biological activity is unprecedented in the last 150 years. Along with work completed on Signy Island (60°S), in the South Orkney Islands, in which we used carbon isotope evidence to show recent climate-related enhancement of CO2 assimilation and peat accumulation rates in Antarctica, the observed relationships between moss growth, microbial activity and climate suggests that moss bank records have the potential to test the regional expression of temperature variability shown by instrumental data on the Antarctic Peninsula over centennial to millennial timescales, by providing long-term records of summer growth conditions

  5. A refinement of the emission data for Kola Peninsula based on inverse dispersion modelling

    NASA Astrophysics Data System (ADS)

    Prank, M.; Sofiev, M.; Denier van der Gon, H. A. C.; Kaasik, M.; Ruuskanen, T. M.; Kukkonen, J.

    2010-06-01

    The study reviews the emission estimates of sulphur oxides (SOx) and primary particulate matter (PM) from the major industrial sources of Kola Peninsula. Analysis of the disagreements between the existing emission inventories for the Kola region combined with forward and inverse ensemble dispersion modelling, analysis of observation time-series and model-measurement comparison showed that the emission of the Nikel non-ferrous metallurgy plant was missing from the EMEP inventory, as well as from some others, being in some cases misplaced or mis-attributed to other sources of the region. A more consistent inventory of the anthropogenic emissions of SOx and PM has been compiled for the peninsula, compared with the existing estimates and verified by means of dispersion modelling. In particular, the SILAM model simulations for 2003 and 2006 with the revised emission data showed much lower bias - up to 6 times for the most-affected sites - for SO2 with regard to the measured concentrations of 8 Finnish and Norwegian observational stations in the region. Temporal correlation improved moderately (10-20%) but homogeneously over Lapland. The study demonstrates the value of a combined usage of forward and inverse ensemble modelling for source apportionment in case of limited observational data.

  6. Surface ozone levels in the forest and vegetation areas of the Biga Peninsula, Turkey.

    PubMed

    Sari, Deniz; İncecik, Selahattin; Ozkurt, Nesimi

    2016-11-15

    Spatial and temporal variability of surface ozone in the rural, mountainous and suburban sites of Biga Peninsula, at the northwest of Turkey which is about 300km southwest of Istanbul was investigated using passive samplers and continuous analyzers. A total 10 passive samplers and two continuous analyzers were used between 1.1.2013 and 31.12.2014. OX levels in the study region were examined to understand NOx dependent or independent contribution to ozone. The influences of the meteorological parameters on ozone levels were also examined by wind speed and ambient temperature. The results clearly show that mountainous areas have higher cumulative exposure to ozone than suburban locations. In order to understand the long range transport sources contributing to the high ozone levels in the region backward trajectories were computed using HYSPLIT model and then clustering of trajectories are performed. The results clearly show the characteristics of pollutant transport from north to Biga Peninsula. Additionally, AOT40 (Accumulated hourly O3 concentrations Over a Threshold of 40ppb) cumulative index was calculated using daytime hourly measurements. The results indicate that the ozone values in the study area are much higher than the critical levels for forest and vegetation based on EU Directive 2008/50/EC. PMID:27474990

  7. Distribution of perfluorinated compounds in Yellow-legged gull eggs (Larus michahellis) from the Iberian Peninsula.

    PubMed

    Vicente, Joana; Bertolero, Albert; Meyer, Johan; Viana, Paula; Lacorte, Silvia

    2012-02-01

    This study is aimed to evaluate the presence and distribution of Perfluorinated Compounds (PFCs) in Yellow-legged gull eggs (Larus michahellis) collected from 8 National or Natural Parks from the Iberian Peninsula. In each colony, 12 eggs were randomly collected and pooled from 3 areas of the colony and analyzed using liquid-solid extraction and liquid chromatography coupled to tandem mass spectrometry. Perfluorooctanate sulfonate (PFOS) was the only compound detected in the eggs and its presence was higher in the colonies situated in NE Iberian Peninsula due to the more industrial and mass urbanization in this area compared to the SW Mediterranean or Atlantic colonies. Accordingly, the Medes site, followed by the Ebro Delta and Columbretes, all situated in the NW Mediterranean coast, contained the highest PFOS levels (40.5-54.0ng/g-ww). In all other colonies, PFOS was detected at levels of 10.1-18.6ng/g-ww. Egg shell biometry was studied and it was found that the presence of PFOS did not affect the development of the egg.

  8. Characteristics of microseismicity in the southeastern area of the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Park, J.; Kang, T.; Lee, J. M.; Kim, W.; Jo, B.; Chung, T.

    2012-12-01

    Characteristics of microseismicity occurred in the southeastern part of the Korean Peninsula are investigated. High-resolution data obtained from a dense temporary seismic network were analyzed with aid of data from the permanent seismograph networks which are administered by several organizations. A hundred of events with magnitude below 3.0 have been observed in the region during about one-year observation. Many of events are clustered in several localized regions and almost all of those events are observed at day time. This implies that those events might be related to the human activity at a limited location such as stone-mining site although we could not confirm our conjecture with eye investigations. The rest of events can be classified into natural earthquakes. Although they show a scattered pattern apparently, some of events are suspected to be related to the neotectonic geological features in the region based on distribution of both the hypocenter and origin time. Focal mechanisms of these events reflect an influence of the regional stress with no noticeable discrepancy from the rest of the Korean Peninsula. The longer observation using the dense temporary seismic network would be highly informative to confirm the relationship between the present seismicity and the neotectonic surface faults of the region. Thus the long-time seismic observations in a region is imperative to reduce uncertainties in seismic hazard assessment in the region.

  9. [Microbial Processes and Genesis of Methane Gas Jets in the Coastal Areas of the Crimea Peninsula].

    PubMed

    Malakhova, T V; Kanapatskii, T A; Egorov, V N; Malakhova, L V; Artemov, Yu G; Evtushenko, D B; Gulin, S B; Pimenov, N V

    2015-01-01

    Hydroasoustic techniques were used for detection and mapping of gas jet areas in the coastal regions of the Crimean peninsula. Gas seep areas in the bays Laspi, Khersones, and Kazach'ya were chosen for detailed microbiological investigation. The first type of gas jets, observed in the Laspi Bay, was probably associated with discarge of deep thermogenic methane along the faults. Methane isotopic composition was char- acterized by Δ13C of -35.3 degrees. While elevated rates of aerobic methane oxidation were revealed in the sandy sediments adjacent to the methane release site, no evidence of bacterial mats was found. The second type of gas emission, observed in the Khersones Bay, was accompanied by formation of bacterial biofilms of the "Thiodendron" microbial community type, predominated by filamentous, spirochete-like organisms, in the areas of gas seepage. The isotopic composition of methane was there considerably lower (-60.4 degrees), indicating a considerable contribution of modern microbial methane to the gas bubbles discharged in this bay. Activity of the third type of gas emission, the seeps of the Kazach'ya Bay, probably depended directly on modern microbial processes of organic matter degradation in the upper sediment layers. The rates of sulfate reduction and methanogenesis were 260 and 34 μmol dm(-3) day(-1), respectively. Our results indicate different mechanisms responsible for formation of methane jets in the Laspi Bay and in the coastal areas of the Heracles Peninsula, where the bays Kazach'ya and Khersones are located.

  10. Elemental content of lichens of the Point Reyes Peninsula, northern California

    USGS Publications Warehouse

    Bennett, J.P.; Benson, S.

    2005-01-01

    The Point Reyes peninsula in northern California is about 45 km northwest of San Francisco and occasionally receives air masses from the city contributing to haze and lowered visibility. Although gaseous pollutants are not a problem, fine particulates containing carbon and other elements are measurable at the park. In this study, five lichen species were sampled along a 40-km linear transect from southeast to northwest from the town of Bolinas at the southern end of the peninsula. Elevated levels of Na and S and the Na/S ratio at localities nearer the ocean confirmed there is a definite marine aerosol influence on lichen elemental content. Elevated potassium and mercury concentrations were also found at high elevation sites that intercept fog. However, arsenic and lead were found to decrease with distance from Bolinas along the transect, suggesting these two elements originate in the fine particulate haze that enters the park from San Francisco. Concentrations of elements were not at enriched levels for other lichen species. A possible local influence of roads on element content needs further study.

  11. Emmons Lake Volcanic Center, Alaska Peninsula: Source of the Late Wisconsin Dawson tephra, Yukon Territory, Canada

    USGS Publications Warehouse

    Mangan, M.T.; Waythomas, C.F.; Miller, T.P.; Trusdell, F.A.

    2003-01-01

    The Emmons Lake Volcanic Center on the Alaska Peninsula of southwestern Alaska is the site of at least two rhyolitic caldera-forming eruptions (C1 and C2) of late Quaternary age that are possibly the largest of the numerous caldera-forming eruptions known in the Aleutian arc. The deposits produced by these eruptions are widespread (eruptive volumes of >50 km3 each), and their association with Quaternary glacial and eolian deposits on the Alaska Peninsula and elsewhere in Alaska and northwestern Canada enhances the likelihood of establishing geochronological control on Quaternary stratigraphic records in this region. The pyroclastic deposits associated with the second caldera-forming eruption (C2) consist of loose, granular, airfall and pumice-flow deposits that extend for tens of kilometres beyond Emmons Lake caldera, reaching both the Bering Sea and Pacific Ocean coastlines north and south of the caldera. Geochronological and compositional data on C2 deposits indicate a correlation with the Dawson tephra, a 24 000 14C BP (27 000 calibrated years BP), widespread bed of silicic ash found in loess deposits in west-central Yukon Territory, Canada. The correlation clearly establishes the Dawson tephra as the time-stratigraphic marker of the last glacial maximum.

  12. [Microbial Processes and Genesis of Methane Gas Jets in the Coastal Areas of the Crimea Peninsula].

    PubMed

    Malakhova, T V; Kanapatskii, T A; Egorov, V N; Malakhova, L V; Artemov, Yu G; Evtushenko, D B; Gulin, S B; Pimenov, N V

    2015-01-01

    Hydroasoustic techniques were used for detection and mapping of gas jet areas in the coastal regions of the Crimean peninsula. Gas seep areas in the bays Laspi, Khersones, and Kazach'ya were chosen for detailed microbiological investigation. The first type of gas jets, observed in the Laspi Bay, was probably associated with discarge of deep thermogenic methane along the faults. Methane isotopic composition was char- acterized by Δ13C of -35.3 degrees. While elevated rates of aerobic methane oxidation were revealed in the sandy sediments adjacent to the methane release site, no evidence of bacterial mats was found. The second type of gas emission, observed in the Khersones Bay, was accompanied by formation of bacterial biofilms of the "Thiodendron" microbial community type, predominated by filamentous, spirochete-like organisms, in the areas of gas seepage. The isotopic composition of methane was there considerably lower (-60.4 degrees), indicating a considerable contribution of modern microbial methane to the gas bubbles discharged in this bay. Activity of the third type of gas emission, the seeps of the Kazach'ya Bay, probably depended directly on modern microbial processes of organic matter degradation in the upper sediment layers. The rates of sulfate reduction and methanogenesis were 260 and 34 μmol dm(-3) day(-1), respectively. Our results indicate different mechanisms responsible for formation of methane jets in the Laspi Bay and in the coastal areas of the Heracles Peninsula, where the bays Kazach'ya and Khersones are located. PMID:26964364

  13. Surface ozone levels in the forest and vegetation areas of the Biga Peninsula, Turkey.

    PubMed

    Sari, Deniz; İncecik, Selahattin; Ozkurt, Nesimi

    2016-11-15

    Spatial and temporal variability of surface ozone in the rural, mountainous and suburban sites of Biga Peninsula, at the northwest of Turkey which is about 300km southwest of Istanbul was investigated using passive samplers and continuous analyzers. A total 10 passive samplers and two continuous analyzers were used between 1.1.2013 and 31.12.2014. OX levels in the study region were examined to understand NOx dependent or independent contribution to ozone. The influences of the meteorological parameters on ozone levels were also examined by wind speed and ambient temperature. The results clearly show that mountainous areas have higher cumulative exposure to ozone than suburban locations. In order to understand the long range transport sources contributing to the high ozone levels in the region backward trajectories were computed using HYSPLIT model and then clustering of trajectories are performed. The results clearly show the characteristics of pollutant transport from north to Biga Peninsula. Additionally, AOT40 (Accumulated hourly O3 concentrations Over a Threshold of 40ppb) cumulative index was calculated using daytime hourly measurements. The results indicate that the ozone values in the study area are much higher than the critical levels for forest and vegetation based on EU Directive 2008/50/EC.

  14. Untangling Antarctic Peninsula deglaciation with dense GPS records

    NASA Astrophysics Data System (ADS)

    Wolstencroft, Martin; Whitehouse, Pippa; Bentley, Mike; King, Matt; Nield, Grace

    2014-05-01

    The Holocene glacial history of the Antarctic Peninsula region is relatively poorly understood but can provide an insight into the evolution of ice sheets during deglaciation. Knowledge of deglacial load changes in the Antarctic Peninsula is also required to correct observations from the GRACE satellite mission for the contribution of Glacial Isostatic Adjustment (GIA) to changes in Earth's gravity field. The uncertainties in this correction propagate into estimates of the Antarctic Ice Sheet contribution to modern global sea-level rise, a question of high importance. We present a study of Antarctic Peninsula ice history based on a comparison of measurements of modern land surface motion with high resolution forward models of GIA. Global Positioning System (GPS) data were collected from Austral summer 2010-2014 in the Southern Antarctic Peninsula; the network remains in place. The models apply a range of ice histories to a spherical Earth with a visco-elastic rheology and produce predictions of present-day GIA. The GPS data were then used to discriminate between competing ice load histories, which consist of both published histories and modifications on published histories. Models of GIA produce uplift maxima with different magnitudes and spatial extent depending on input parameters. Significant uncertainty in the modelled GIA arises from the assumed structure of the solid Earth, which is poorly constrained. To understand how this uncertainty impacts the interpretation of the GPS data, we tested a plausible range of values for lithospheric thicknesses and mantle viscosity. The results of the data-model comparison provide an evaluation of the spatial and temporal sensitivity of regionally dense GPS records to deglaciation on the Antarctic Peninsula.

  15. Drought variability and change across the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Coll, Joan Ramon; Aguilar, Enric

    2015-04-01

    Drought variability and change is assessed in this study across the Iberian Peninsula along the 20th century and the first decade of the 21st century using state of the art drought indices: the Sc-PDSI, the SPI and the SPEI. Daily temperature and precipitation data from 24 time-series regularly spread over Iberian Peninsula are quality controlled and also homogenized in a monthly scale to create the Monthly Iberian Temperature and Precipitation Series (MITPS) for the period 1906-2010. The Sc-PDSI, the 12-month SPI and 12-month SPEI are computed on a monthly basis using the newly MITPS dataset to identify dry and wet conditions across time. Precipitation data is only required to compute SPI, but potential evapotranspiration (PET) is also needed to perform the Sc-PDSI and SPEI, which is estimated using the Tornthwaite's method. The analysis conducted in this study confirms that drought conditions are worsening for most of the Iberian Peninsula across time strongly induced by global warming especially during the last three decades. All drought indices have found a drying trend in the Pyrenees, Ebro basin, central Iberia and in the south and south-eastern area while a wetting trend is identified in the western and in the north-western region. Future projections also indicate a clear increase in hydrological drought conditions along the 21st century, thus, water saving and the application of effective water management strategies will be crucial to minimize the impact of hydrological droughts over the Iberian Peninsula into the near future. KEY WORDS: Drought, climate change, Iberian Peninsula, drought indices.

  16. Quantification of subaerial and episodic subglacial erosion rates on high latitude upland plateaus: Cumberland Peninsula, Baffin Island, Arctic Canada

    NASA Astrophysics Data System (ADS)

    Margreth, Annina; Gosse, John C.; Dyke, Arthur S.

    2016-02-01

    Long-term rates of subaerial and episodic subglacial erosion by predominately cold-based ice cover are determined for tors on weathered plateaus on Cumberland Peninsula. By measuring terrestrial cosmogenic nuclide concentrations in differentially weathered surfaces on a given tor, we reconstruct the complex exposure and erosion history involving recurring cold-based ice cover. The style and rate of subaerial and subglacial erosion at multiple tor sites on Cumberland Peninsula are assessed with a Monte Carlo approach that computes plausible exposure histories based on a proxy record of global ice volume. Constant subaerial erosion rates by weathering are low (<2 mm ka-1), corroborated by nuclide concentrations measured on two tors located on coastal ridge crests that have likely never been glaciated. Summit plateaus intermittently covered by cold-based ice throughout the Quaternary have experienced episodic subglacial erosion by plucking of fractured bedrock with rates between 1 and 16 mm ka-1. Variation of episodic erosion rates is associated with topographic position of the sampled tors and bedrock fracture density. Most of the tors were last glacially plucked in pre-ultimate glaciations, not during the Wisconsinan glaciation. Furthermore, the new approach provides evidence for the extent of ice coverage during the late Wisconsinan, which is significant if no erratics are available for exposure dating. Despite late Pleistocene intervals of ice cover and glacial plucking, tor-studded landscapes of Cumberland Peninsula are of considerable antiquity.

  17. Wildlife uses and hunting patterns in rural communities of the Yucatan Peninsula, Mexico

    PubMed Central

    2012-01-01

    Background Subsistence hunting is a traditional practice providing food and many other goods for households in the Yucatan Peninsula, southeast Mexico. Economic, demographic, and cultural change in this region drive wildlife habitat loss and local extinctions. Improving our understanding about current practices of wildlife use may support better management strategies for conserving game species and their habitat. We aimed to evaluate if wildlife use remained relevant for the subsistence of rural residents of the Yucatan Peninsula, as well as if local hunting practices were related to environmental, geographical, and cultural factors. Methods Fieldwork was done between March 2010 and March 2011. Information was obtained through conversations, interviews, and participant observation. Record forms allowed recording animals hunted, biomass extracted, distance intervals to hunting sites, habitat types and seasonality of wildlife harvests. Data were analyzed using one-way Analysis of Variance, and Generalized Linear Models. Results Forty-six terrestrial vertebrate species were used for obtaining food, medicine, tools, adornments, pets, ritual objects, and for sale and mitigating damage. We recorded 968 animals taken in 664 successful hunting events. The Great Curassow, Ocellated Turkey, paca, white-tailed deer, and collared peccary were the top harvested species, providing 80.7% of biomass (10,190 kg). The numbers of animals hunted and biomass extracted declined as hunting distances increased from villages. Average per capita consumption was 4.65 ± 2.7 kg/person/year. Hunting frequencies were similar in forested and agricultural areas. Discussion Wildlife use, hunting patterns, and technologies observed in our study sites were similar to those recorded in previous studies for rural Mayan and mestizo communities in the Yucatan Peninsula and other Neotropical sites. The most heavily hunted species were those providing more products and by-products for residents. Large

  18. Continental shelf benthos off Otago Peninsula, New Zealand

    NASA Astrophysics Data System (ADS)

    Probert, P. Keith; Wilson, John B.

    1984-09-01

    Benthic macrofauna of the continental shelf off Otago Peninsula, south-eastern New Zealand (45°51'S, 170°52'E) was surveyed by dredge sampling during 1973-1975. Numerical classification (Canberra metric coefficient and flexible sorting) was used to produce site groups and species groups, and three major benthic communities were recognised: a shallow-water (14-25 m) fauna inhabiting well-sorted fine sand, a mid-shelf fauna (concentrated in the depth range 50-76 m) associated with sediments containing the greatest proportions of gravel and siltclay, and a predominantly sand-bottom fauna occurring mainly on the outer shelf (87-150 m). All station groups were dominated numerically by polychaetes (mean of 36·6-56% of individuals) with Mollusca (13·8-25%) or Crustacea (12·1-19·4%) the next most abundant group. The inshore sand fauna was the most distinct, characteristic elements being the trochid gastropod Antisolarium egenum, an amphipod of the genus Hippomedon and dense patches of the spionid polychaete Spiophanes bombyx. Diagnostic species of the mid-shelf mixed sediments were Lepidonotus jacksoni, Psammolyce antipoda, Lumbrineris brevicirra and Phyllamphicteis foliata (Polychaeta), Terenochiton otagoensis, Micrelenchus caelatus caelatus, Maoricolpus roseus roseus and Zegalerus tenuis (Mollusca), Ampelisca chiltoni (Amphipoda) and Amphipholis squamata (Ophiuroidea). Outer shelf sand stations were faunally less distinct, but among the more characteristic species were Euthalenessa fimbriata, Sigalion sp. and Euchone sp. (Polychaeta) and Gari stangeri (Bivalvia). Several abundant species were widely distributed among station groups, notably Nephtys macroura, Lumbrineris magalhaensis, Phyllochaetopterus socialis and Owenia fusiformis (Polychaeta) and Nucula nitidula and Tawera spissa (Bivalvia). Free-living lunulitiform Bryozoa of the genus Otionella were a characteristic component of inner and outer shelf sand faunas, and their inshore penetration probably marks

  19. Pan American Airways/Naval Air Transport Service/destroyer base site showing brick ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pan American Airways/Naval Air Transport Service/destroyer base site showing brick and concrete paving of patio, and circular planters. View facing east. - U.S. Naval Base, Pearl Harbor, Pearl City Peninsula, Pearl City, Honolulu County, HI

  20. Pan American Airways/Naval Air Transport Service/destroyer base site showing stone ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pan American Airways/Naval Air Transport Service/destroyer base site showing stone wall around patio. View facing east-southeast. - U.S. Naval Base, Pearl Harbor, Pearl City Peninsula, Pearl City, Honolulu County, HI

  1. Evolution of subsidence styles in forearc basin: example from Cretaceous of southern Vizcaino Peninsula, Baja California, Mexico

    SciTech Connect

    Busby-Spera, C.J.; Boles, J.R.

    1986-04-01

    Late Jurassic to Early Cretaceous arc magmatism is represented by volcaniclastic rocks of the Eugenia Formation in the northern Vizcaino Peninsula and by the metamorphosed Cedros-San Andres volcanoplutonic complex, with a dismembered ophiolitic basement, in the southern peninsula. The Vizcaino Peninsula became the site of forearc sedimentation by the Aptian-Albian (late Early Cretaceous), when arc magmatism moved abruptly eastward to the present-day Peninsular Range. On the southern Vizcaino Peninsula, a conformable stratigraphic section, complicated by later faulting, records a gradual transition from a ridged forearc, broken by basement uplifts and grabens (the Aptian-Albian Asunction Formation), to a broadly subsiding, deep marine forearc basin (the Cenomanian Valle Formation). The basal contact of the Asunction formation has irregular relief caused by brecciated basement rocks and talus accumulated along fault zones. An upward-fining sequence several hundred meters thick records abrupt uplift and gradual denudation of adjacent metamorphic basement. Contemporaneous andesite arc volcanism to the east supplied ash and fresh volcanic detritus to the grabens. Angular sand to boulder-size detritus of the Asunction Formation was derived locally, and includes basic to intermediate meta-igneous rock fragments, with epidote, actinolite, and chlorite, as well as serpentine. Abundant calcareous fossils are commonly unbroken, suggesting local sources for these as well. Angular to subrounded, sand to cobble-sized, intermediate to mafic volcanic rock fragments were derived from a more distant island arc to the east, which occasionally provided intermediate to felsic tuffs to the basin. This source is probably represented by the Aptian-Albian Alisitos Group, which forms much of the western wall of the Late Cretaceous Peninsular Range batholith.

  2. Paleoseismic Study on the Peninsula Section of the San Andreas Fault South of Crystal Springs Reservoir, San Mateo County, California

    NASA Astrophysics Data System (ADS)

    Zachariasen, J. A.; Prentice, C. S.; Kozaci, O.; Sickler, R. R.; Baldwin, J. N.; Sanquini, A.; Knudsen, K. L.

    2010-12-01

    The Peninsula section of the San Andreas Fault is a significant hazard for the San Francisco Bay area, but little is known about the timing of earthquakes on this section of the fault prior to the great earthquake of April 18, 1906. An earthquake in 1838 resulted in strong shaking on the San Francisco Peninsula. Estimates of the magnitude of the 1838 earthquake vary from 6.8 to 7.4, based on historical accounts, and most workers have assumed that this event occurred on the San Andreas Fault. However, paleoseismic excavations across the fault near San Andreas Lake failed to provide evidence that the 1838 earthquake was associated with surface rupture on the Peninsula section of the San Andreas Fault (Prentice et al., 2008, 2009). Earlier work at the Filoli Estate, south of Crystal Springs Reservoirs, by Hall et al. (1999) suggested that both the 1838 and 1906 earthquakes ruptured the Peninsula section, based on the projected offsets of buried stream channels that crossed the fault. While this interpretation is permissible, the data also allow alternative interpretations that do not require surface rupture in 1838. We used LiDAR images produced from data collected by the GeoEarthScope project to search for promising paleoseismic sites along the Peninsula section of the San Andreas Fault. At a site about 1.2 km southeast of Crystal Springs Reservoir, we excavated two trenches across the fault and exposed fluvial gravel and overbank deposits cut by two distinct generations of faults. The younger set of faults break nearly to the ground surface, and we interpret these to represent 1906 surface faulting that has been buried post-1906 sediments. The older faults terminate below a colluvial wedge derived from one of the fluvial gravel deposits. The scarp-derived colluvium overlies a faulted fine-grained overbank deposit that in turn rests on the channel gravel, and represents the ground surface at the time of the older earthquake. The scarp-derived colluvium is overlain by

  3. Hurricane Ike Deposits on the Bolivar Peninsula, Galveston Bay, Texas

    NASA Technical Reports Server (NTRS)

    Evans, Cynthia A.; Wilkinson, M. J.; Eppler, Dean

    2011-01-01

    In September 2008, Hurricane Ike made landfall on Galveston Bay, close to the NASA Johnson Space Center (JSC). The storm flooded much of the area with a storm surge ranging from 11 -20 feet. The Bolivar peninsula, the southeastern coast of Galveston Bay, experienced the brunt of the surge. Several agencies collected excellent imagery baselines before the storm and complementary data a few days afterward that helped define the impacts of the storm. In April of 2011, a team of scientists and astronauts from JSC conducted field mapping exercises along the Bolivar Peninsula, the section of the Galveston Bay coast most impacted by the storm. Astronauts routinely observe and document coastal changes from orbit aboard the International Space Station. As part of their basic Earth Science training, scientists at the Johnson Space Center take astronauts out for field mapping exercises so that they can better recognize and understand features and processes that they will later observe from the International Space Station. Using pre -storm baseline images of the Bolivar Peninsula near Rollover Pass and Gilchrist (NOAA/Google Earth Imagery and USGS aerial imagery and lidar data), the astronauts mapped current coastline positions at defined locations, and related their findings to specific coastal characteristics, including channel, jetties, and other developments. In addition to mapping, we dug trenches along both the Gulf of Mexico coast as well as the Galveston Bay coast of the Bolivar peninsula to determine the depth of the scouring from the storm on the Gulf side, and the amount of deposition of the storm surge deposits on the Bay side of the peninsula. The storm signature was easy to identify by sharp sediment transitions and, in the case of storm deposits, a layer of storm debris (roof shingles, PVC pipes, etc) and black, organic rich layers containing buried sea grasses in areas that were marshes before the storm. The amount of deposition was generally about 20 -25 cm

  4. Hurricane Ike Deposits on the Bolivar Peninsula, Galveston Bay, Texas

    NASA Astrophysics Data System (ADS)

    Evans, C. A.; Wilkinson, M. J.; Eppler, D.

    2011-12-01

    In September 2008, Hurricane Ike made landfall on Galveston Bay, close to the NASA Johnson Space Center (JSC). The storm flooded much of the area with a storm surge ranging from 11-20 feet. The Bolivar peninsula, the southeastern coast of Galveston Bay, experienced the brunt of the surge. Several agencies collected excellent imagery baselines before the storm and complementary data a few days afterward that helped define the impacts of the storm. In April of 2011, a team of scientists and astronauts from JSC conducted field mapping exercises along the Bolivar Peninsula, the section of the Galveston Bay coast most impacted by the storm. Astronauts routinely observe and document coastal changes from orbit aboard the International Space Station. As part of their basic Earth Science training, scientists at the Johnson Space Center take astronauts out for field mapping exercises so that they can better recognize and understand features and processes that they will later observe from the International Space Station. Using pre-storm baseline images of the Bolivar Peninsula near Rollover Pass and Gilchrist (NOAA/Google Earth Imagery and USGS aerial imagery and lidar data), the astronauts mapped current coastline positions at defined locations, and related their findings to specific coastal characteristics, including channel, jetties, and other developments. In addition to mapping, we dug trenches along both the Gulf of Mexico coast as well as the Galveston Bay coast of the Bolivar peninsula to determine the depth of the scouring from the storm on the Gulf side, and the amount of deposition of the storm surge deposits on the Bay side of the peninsula. The storm signature was easy to identify by sharp sediment transitions and, in the case of storm deposits, a layer of storm debris (roof shingles, PVC pipes, etc) and black, organic rich layers containing buried sea grasses in areas that were marshes before the storm. The amount of deposition was generally about 20-25 cm; the

  5. Antarctic Peninsula Ice Sheet evolution during the Cenozoic Era

    NASA Astrophysics Data System (ADS)

    Davies, Bethan J.; Hambrey, Michael J.; Smellie, John L.; Carrivick, Jonathan L.; Glasser, Neil F.

    2012-01-01

    The Antarctic Peninsula region is currently undergoing rapid environmental change, resulting in the thinning, acceleration and recession of glaciers and the sequential collapse of ice shelves. It is important to view these changes in the context of long-term palaeoenvironmental complexity and to understand the key processes controlling ice sheet growth and recession. In addition, numerical ice sheet models require detailed geological data for tuning and testing. Therefore, this paper systematically and holistically reviews published geological evidence for Antarctic Peninsula Ice Sheet variability for each key locality throughout the Cenozoic, and brings together the prevailing consensus of the extent, character and behaviour of the glaciations of the Antarctic Peninsula region. Major contributions include a downloadable database of 186 terrestrial and marine calibrated dates; an original reconstruction of the LGM ice sheet; and a new series of isochrones detailing ice sheet retreat following the LGM. Glaciation of Antarctica was initiated around the Eocene/Oligocene transition in East Antarctica. Palaeogene records of Antarctic Peninsula glaciation are primarily restricted to King George Island, where glacigenic sediments provide a record of early East Antarctic glaciations, but with modification of far-travelled erratics by local South Shetland Island ice caps. Evidence for Neogene glaciation is derived primarily from King George Island and James Ross Island, where glaciovolcanic strata indicate that ice thicknesses reached 500-850 m during glacials. This suggests that the Antarctic Peninsula Ice Sheet draped, rather than drowned, the topography. Marine geophysical investigations indicate multiple ice sheet advances during this time. Seismic profiling of continental shelf-slope deposits indicates up to ten large advances of the Antarctic Peninsula Ice Sheet during the Early Pleistocene, when the ice sheet was dominated by 40 kyr cycles. Glacials became more

  6. High shrew diversity on Alaska's Seward Peninsula: Community assembly and environmental change

    USGS Publications Warehouse

    Hope, Andrew G.

    2012-01-01

    In September 2010, 6 species of shrews (genus: Sorex) were collected at a single locality on the Seward Peninsula of Alaska. Such high sympatric diversity within a single mammalian genus is seldom realized. This phenomenon at high latitudes highlights complex Arctic community dynamics that reflect significant turnover through time as a consequence of environmental change. Each of these shrew species occupies a broad geographic distribution collectively spanning the entire Holarctic, although the study site lies within Eastern Beringia, near the periphery of all individual ranges. A review of published genetic evidence reflects a depauperate shrew community within ice-free Beringia through the last glaciation, and recent assembly of current diversity during the Holocene.

  7. LARISSA: Benthic Foraminiferal Analysis from Barilari Bay, western Antarctic Peninsula margin

    NASA Astrophysics Data System (ADS)

    Matulaitis, I.; Ishman, S. E.; Leventer, A.; Brachfeld, S. A.; Jeong, S.; Domack, E. W.

    2011-12-01

    The LARISSA (LARsen Ice Shelf System, Antarctica) Project is an interdisciplinary project funded by the US National Science Foundation bringing together marine and Quaternary geology, cryosphere, ocean and marine ecology. The goal of LARISSA is to use the Larsen Ice Shelf System to study climate change effects on ice shelf systems and the oceanic and ecological responses to ice shelf collapse. This study focuses on jumbo piston core (JPC) 127 collected during cruise NBP 10-01. The 8.5 meter core was recovered from Barilari Bay (65.917°S 64.700°W) on the western side of the Antarctic Peninsula. The core site at the outer edge of the bay is of particular interest due to its location between the inner fjord high deposition rate sites and the more distal middle shelf sites, its exposure to open ocean circulation within the bay, and its proximity to the ice core site drilled on the Bruce Plateau during the LARISSA project. The abundance of calcareous taxa throughout the core makes it a target for isotopic studies. The recovered section was sampled for a variety of proxy measurements with samples collected for benthic foraminiferal analysis at 10 cm intervals. Correlation of the magnetic susceptibility data, as well as a peak in the diatom Eucampia antarctica from JPC 127 and other core records from the western Antarctic Peninsula indicate recovery of at least mid-Holocene through recent. Foraminiferal analyses resulted in the identification of 92 species of foraminifera. Three of the abundant species are indicators of specific water masses. Bulimina aculeata is indicative of the warmer, less saline Circumpolar Deep Water (CDW). Marked high abundance of Bulimina aculeata in the uppermost 600 cm indicates incursions of CDW onto the continental shelf and into Barilari Bay. This period of increased Bulimina aculeata abundance is also seen in other cores taken around the peninsula such as kasten core (KC) 11 in the Hugo Island Trough and in the Palmer Deep. Fursenkoina is

  8. Magnetic Properties of Quaternary Deposits, Kenai Peninsula, Alaska -- Implications for Aeromagnetic Anomalies of Upper Cook Inlet

    USGS Publications Warehouse

    Saltus, R.W.; Haeussler, P.J.

    2004-01-01

    We measured magnetic susceptibilities of exposed Quaternary deposits on several beach cliffs and river banks on the Kenai Peninsula near Soldotna, Alaska. Data, descriptions, and photos from nine sites are included in this report. The mean susceptibility for Quaternary materials in this region is approximately 2.5 x 10-3 SI units. This is sufficiently magnetic to produce subtle aeromagnetic anomalies such as those observed to correlate with topographic features in the region of the measurements. The highest susceptibilities measured (greater than 20 x 10-3 SI units) may help, at least in part, to explain moderate amplitude aeromagnetic anomalies observed elsewhere in Cook Inlet, particularly those relating to structures showing Quaternary movement. Comparison of measured beach cliff susceptibility and susceptibility predicted from idealized formulas and two-dimensional cliff models suggests that measured susceptibilies underestimate true bulk susceptibility by 20 percent to 50 percent in this region.

  9. Modelling Chemical Patterns of Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Ratola, Nuno; Jiménez-Guerrero, Pedro

    2013-04-01

    Semi-volatile organic compounds (SVOCs) such as PBDEs, PCBs, organochlorine pesticides (OCPs) or PAHs, are widespread and generated in a multitude of anthropogenic (and natural for PAHs) processes and although they are found in the environment at low concentrations, possess an extraordinary carcinogenic capacity (Baussant et al., 2001) and high ecotoxicity due to their persistence in different matrices (air, soil, water, living organisms). In particular, PAHs are originated by combustion processes or release from fossil fuels and can be transported in the atmosphere over long distances in gaseous or particulate matter (Baek et al., 1991). The establishment of strategies for sampling and chemical transport modelling of SVOCs in the atmosphere aiming the definition and validation of the spatial, temporal and chemical transport patterns of contaminants can be achieved by an integrated system of third-generation models that represent the current state of knowledge in air quality modelling and experimental data collected in field campaigns. This has implications in the fields of meteorology, atmospheric chemistry and even climate change. In this case, an extensive database already obtained on levels of atmospheric PAHs from biomonitoring schemes in the Iberian Peninsula fuelled the establishment of the first models of behaviour for PAHs. The modelling system WRF+CHIMERE was implemented with high spatial and temporal resolution to the Iberian Peninsula in this first task (9 km for the Iberian Peninsula, 3 km to Portugal, 1 hour), using PAHs atmospheric levels collected over a year-long sampling scheme comprising 4 campaigns (one per season) in over 30 sites. Daily information on meteorological parameters such as air temperature, humidity, rainfall or wind speed and direction was collected from the weather stations closest to the sampling sites. Diagnosis and forecasts of these meteorological variables using MM5 or WRF were used to feed a chemistry transport model

  10. Distribution of Radioactive Materials in the Absheron Peninsula, Azerbaijan - 13567

    SciTech Connect

    Vandergraaf, Tjalle T.; Mamedov, Gudrat G.; Ramazanov, Mahammadali A.; Badalov, Vatan H.; Naghiyev, Jalal A.; Mehdiyeva, Afat A.

    2013-07-01

    The Absheron Peninsula forms the extreme Eastern part of Azerbaijan and juts into the Caspian Sea. The region has a long history of oil and gas exploration, transport, and processing and includes a number of abandoned chemical plants that were used in the separation of iodine from formation waters. As a result of lax environmental standards during the Soviet era, the industrial activity has led to serious contamination from oils residues, heavy metals and naturally occurring radioactive materials (NORM). Radiometric surveys performed over a wide range of the Absheron Peninsula showed generally low NORM concentrations. However, radiation levels two to three orders of magnitude above background levels were detected at two abandoned iodine separation plants near the capital city, Baku. These elevated radiation levels are mainly due to Ra-226 and U-238 with lower contributions from Ra-228 and U-235. (authors)

  11. Crustal structure beneath the Indochina peninsula from teleseismic receiver functions

    NASA Astrophysics Data System (ADS)

    Bai, Ling; Tian, Xiaobo; Ritsema, Jeroen

    2010-12-01

    We analyze teleseismic receiver functions to determine the crustal structure beneath the Indochina peninsula which is located immediately south-east of the eastern Himalayan syntaxis basin. We found that the Indochina peninsula is characterized by a thin (˜31 km) crust with a low Vp/Vs ratio (˜1.68). The intra-lower crustal low-velocity zone (LVZ) is observed beneath the northwestern part of our study region. We hypothesize that it is an extension of the lower crustal LVZ observed beneath the southeastern Tibet and the South China block and that it terminates at the Dien Bien Phu Fault (DBPF). A LVZ observed in the upper crust beneath southeast of the DBPF indicates that the crust is ductile and earthquakes are rare.

  12. [Populational chromosomal polymorphism the Asian forest mouse Apodemus peninsulae].

    PubMed

    Bekasova, T S; Vorontsov, N N

    1975-01-01

    29 individuals of Apodemus peninsulae, an Asian forest mouse from the Suputin State Nature Reserve (Maritime Territory) were studied karyologically. Diploid chromosome sets of the animals studied contained from 48 to 52 chromosomes. The difference in the diploid chromosome numbers is caused by the presence in some individuals of supernumerary metacentric chromosomes (up to 4). The set is always represented by 48 acrocentric chromosomes, gradually decreasing in size. The supernumerary metacentric chromosomes vary in size from medium-sized to the smallest in the set. The character of intrapopulational chromosome polymorphism of continental and island populations of Apodemus peninsulae is discussed. Attempts are made to explain the polymorphism with respect to supernumerary chromosomes as the result of some viral diseases.

  13. The subgenus Andrena (Micrandrena) (Hymenoptera: Andrenidae) in the Iberian Peninsula.

    PubMed

    Dardón, María José; Torres, Félix; Ornosa, Concepción

    2014-10-13

    This work presents the results obtained after a revision of the current species of the subgenus Andrena (Micrandrena) Ashmead, 1899 that appear in the Iberian Peninsula. It provides a key to the species, diagnosis, biological data, and comments about the 19 species and 5 subspecies. Additionally, it includes a redescription of five species because their original descriptions were inadequate. Newly reported for the Iberian Peninsula are Andrena floricola Eversmann, 1852 and Andrena strohmella Stöckhert, 1928. This study is the first contribution to resolve certain taxonomic problems in the subgenus Andrena (Micrandrena); however, the use of additional tools like morphometric and molecular characters are recommended in the future to confirm the taxonomic status of Andrena spreta Pérez, 1895. 

  14. The relative influence of ENSO and SAM on Antarctic Peninsula climate

    NASA Astrophysics Data System (ADS)

    Clem, Kyle R.; Renwick, James A.; McGregor, James; Fogt, Ryan L.

    2016-08-01

    Recent warming of the Antarctic Peninsula during austral autumn, winter, and spring has been linked to sea surface temperature (SST) trends in the tropical Pacific and tropical Atlantic, while warming of the northeast Peninsula during summer has been linked to a strengthening of westerly winds traversing the Peninsula associated with a positive trend in the Southern Annular Mode (SAM). Here we demonstrate that circulation changes associated with the SAM dominate interannual temperature variability across the entire Antarctic Peninsula during both summer and autumn, while relationships with tropical Pacific SST variability associated with the El Niño-Southern Oscillation (ENSO) are strongest and statistically significant primarily during winter and spring only. We find the ENSO-Peninsula temperature relationship during autumn to be weak on interannual time scales and regional circulation anomalies associated with the SAM more important for interannual temperature variability across the Peninsula during autumn. Consistent with previous studies, western Peninsula temperatures during autumn, winter, and spring are closely tied to changes in the Amundsen Sea Low (ASL) and associated meridional wind anomalies. The interannual variability of ASL depth is most strongly correlated with the SAM index during autumn, while the ENSO relationship is strongest during winter and spring. Investigation of western and northeast Peninsula temperatures separately reveals that interannual variability of northeast Peninsula temperatures is primarily sensitive to zonal wind anomalies crossing the Peninsula and resultant leeside adiabatic warming rather than to meridional wind anomalies, which is closely tied to variability in the zonal portion of the SAM pattern.

  15. Evaluation Of Elastic Strain Accumulation In The Southern Indian Peninsula By GPS-Geodesy

    NASA Astrophysics Data System (ADS)

    Narayanababu, R.; Ec, M.; Tummala, C.

    2004-12-01

    The computed elastic strain accumulation in the southern Indian peninsula from the GPS derived velocity fields of the global network of GPS stations, in and around the Indian plate which includes Maitri, Indian Antarctic Station, show a significant departure from rigid plate behaviour in a manner consistent with the mapped intra plate stress field, observations of deformations and seismicity in the region. Our results of intraplate strain accumulation within Antarctica Plate covering three sites MAIT, CAS1 and DAV1 are 1.8x10-9yr-1, 1.6x10-9yr-1 and 1.1x10-9yr-1, respectively. Similarly, the estimates of interplate strain accumulation between Antarctica and other plates Somalia (SEY1), Africa (HARO), Australia (YAR1), and diffuse plate boundary between India and Australia (COCO) are found to be 1.1x10-9yr-1, 1.0x10-10yr-1, 1.27x10-8yr-1 and 1.18x10-8yr-1, respectively. These estimates are in good agreement with the earlier studies on estimation of global strain rate. The combined GPS and seismic analysis confirm the emergence of diffuse plate boundary between India and Australia and relates to the late Miocene Himalayan uplift. The calculated stress field in the West of the Indian Peninsula has a roughly N-S directed tensional and E-W oriented compressional character and the velocity vectors of all other sites throw a significant insight into the plausible causes of the strain accumulation processes in the Indian Ocean and the northward movement of Indian plate.

  16. Ground-water flow and water quality in the sand aquifer of Long Beach Peninsula, Washington

    USGS Publications Warehouse

    Thomas, B.E.

    1995-01-01

    This report describes a study that was undertaken to improve the understanding of ground-water flow and water quality in the coastal sand aquifer of the Long Beach Peninsula of southwestern Washington. Data collected for the study include monthly water levels at 103 wells and 28 surface-water sites during 1992, and water-quality samples from about 40 wells and 13 surface-water sites in February and July 1992. Ground water generally flows at right angles to a ground-water divide along the spine of the low-lying peninsula. Historical water-level data indicate that there was no long-term decline in the water table from 1974 to 1992. The water quality of shallow ground water was generally good with a few local problems. Natural concentrations of dissolved iron were higher than 0.3 milligrams per liter in about one-third of the samples. The dissolved-solids concentrations were generally low, with a range of 56 to 218 milligrams per liter. No appreciable amount of seawater has intruded into the sand aquifer, chloride concentrations were low, with a maximum of 52 milligrams per liter. Agricultural activities do not appear to have significantly affected the quality of ground water. Concentrations of nutrients were low in the cranberry-growing areas, and selected pesticides were not found above the analytical detection limits. Septic systems probably caused an increase in the concentration of nitrate from medians of less than 0.05 milligrams per liter in areas of low population density to 0.74 milligrams per liter in areas of high density.

  17. Prokaryotic Community in Lacustrine Sediments of Byers Peninsula (Livingston Island, Maritime Antarctica).

    PubMed

    Gugliandolo, Concetta; Michaud, Luigi; Lo Giudice, Angelina; Lentini, Valeria; Rochera, Carlos; Camacho, Antonio; Maugeri, Teresa Luciana

    2016-02-01

    Byers Peninsula (Livingston Island, Antarctica), the largest seasonally ice-free region of the Maritime Antarctica, holds a large number of lakes, ponds, and streams. The prokaryotic structure and bacterial diversity in sediment samples collected during the 2008-2009 austral summer from five inland lakes, two coastal lakes, and an estuarine site were analyzed by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) and 16S rRNA 454 tag pyrosequencing techniques, respectively. Differently from inland lakes, which range around the oligotrophic status, coastal lakes are eutrophic environments, enriched by nutrient inputs from marine animals. Although the prokaryotic abundances (estimated as DAPI stained cells) in sediment samples were quite similar among inland and coastal lakes, Bacteria always far dominated over Archaea. Despite the phylogenetic analysis indicated that most of sequences were affiliated to a few taxonomic groups, mainly referred to Proteobacteria, Bacteroidetes, and Actinobacteria, their relative abundances greatly differed from each site. Differences in bacterial composition showed that lacustrine sediments were more phyla rich than the estuarine sediment. Proteobacterial classes in lacustrine samples were dominated by Betaproteobacteria (followed by Alphaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria), while in the estuarine sample, they were mainly related to Gammaproteobacteria (followed by Deltaproteobacteria, Epsilonproteobacteria, Alphaproteobacteria, and Betaproteobacteria). Higher number of sequences of Alphaproteobacteria, Cyanobacteria, Verrucomicrobia, and Planctomycetes were observed in sediments of inland lakes compared to those of coastal lakes, whereas Chloroflexi were relatively more abundant in the sediments of coastal eutrophic lakes. As demonstrated by the great number of dominant bacterial genera, bacterial diversity was higher in the sediments of inland lakes than that in coastal lakes

  18. Spatial and temporal variability of periglaciation of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Oliva, M.; Serrano, E.; Gómez-Ortiz, A.; González-Amuchastegui, M. J.; Nieuwendam, A.; Palacios, D.; Pérez-Alberti, A.; Pellitero-Ondicol, R.; Ruiz-Fernández, J.; Valcárcel, M.; Vieira, G.; Antoniades, D.

    2016-04-01

    Active periglacial processes are currently marginal in the Iberian Peninsula, spatially limited to the highest mountain ranges. However, a wide variety of periglacial deposits and landforms are distributed in low and mid-altitude environments, which shows evidence of past periods of enhanced periglacial activity. The purpose of this paper is to summarize the present knowledge of past periglacial activity in the Iberian Peninsula. The chronological framework takes four main stages into account: the last glaciation, deglaciation, Holocene and present-day processes. This study focuses on the highest massifs (Pyrenees, Cantabrian Range, NW ranges, Central Range, Iberian Range, Sierra Nevada) as well as other lower elevation environments, namely the central Iberian Meseta. During the last glaciation the periglacial belt extended to much lower altitudes than today, reaching current sea level in the NW corner of the Iberian Peninsula. A wide range of geomorphological landforms and sedimentary records is indicative of very active periglacial processes during that phase, in some cases related to permafrost conditions (i.e., block streams, rock glaciers). Most of the inactive landforms and deposits in low and mid-elevations in Iberia are also related to this phase. The massive deglaciation of the Iberian massifs was caused by a gradual increase in temperatures. The deglaciation phase was only interrupted by a short period with colder conditions (the Younger Dryas) that reactivated periglacial processes in the formerly glaciated cirques of the highest lands, specifically with the widespread development of rock glaciers. During the Holocene, periglacial processes have been only active in the highest ranges, shifting in altitude according to temperature regimes and moisture conditions. The Little Ice Age saw the reactivation of periglacial activity in lower elevations than today. Currently, periglacial processes are only active in elevations exceeding 2500 m in the southern

  19. Fossils from bore holes on the Eastern Shore Peninsula, Virginia

    USGS Publications Warehouse

    Todd, Ruth; Gardner, Julia A.; Sohn, I.G.

    1955-01-01

    This report lists Foraminifera, Mollusca, and Ostracoda in five bore holes that penetrated a maximum of 445 feet of section in sediments of Pleistocene and Miocene age, and discusses the paleoecologic and stratigraphic significance of the fossils. It includes the contents of references 6, 16, and 18 of Virginia Division of Geology Mineral Resources Circular No. 2, dealing with the geology and groundwater resources of the Eastern Shore peninsula.

  20. Holocene records of geomagnetic field behavior from a north-south transect along the western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Brachfeld, S. A.; Shah, D. P.; St-Onge, M.; St-Onge, G.

    2013-12-01

    Geochronology is inherently difficult when working with Antarctic margin sediments. Radiocarbon dating and oxygen isotope stratigraphy are challenging or impossible in sites with poor preservation of biogenic calcite. Radiocarbon dating of the acid insoluble organic matter (AIOM) is further complicated by organically lean sediment and the presence of reworked organic carbon or detrital carbon from sedimentary rocks. These complications limit the ability to interpret a paleoclimate record. Geomagnetic paleointensity dating is a proven 'tuning' technique that has been successfully applied in several studies around the Antarctic margin. However, the reference curves to which these sites were tuned were constructed primarily from Northern Hemisphere data. Here we present paleomagnetic secular variation (PSV) and relative paleointensity (RPI) data from three Antarctic Peninsula sites that possess independent chronologies and which have moderate to ultra-high sedimentation rates (40 - 700 cm/ka). Maxwell Bay, located in the volcanic South Shetland Islands, is an ultra-high-resolution site with strongly magnetic sediments from which the Shallow Drilling (SHALDRIL) program recovered a 108-m record spanning the last 14 ka. Outer Barilari Bay and Hugo Island Trough, which lie to the South along the western Antarctic Peninsula, are moderate resolution sites with a high proportion of biogenic silica. Maxwell Bay and Bariliari Bay are unique in that they possess homogenous sediment and uniform magnetic mineral assemblages, while also preserving biogenic calcite, a rare combination on the Antarctic margin. All three sites preserve strong, stable remanent magnetizations with an easily isolated characteristic component and MAD values generally < 2°, with the exception of turbidites, intervals with abundant dropstones, and biosiliceous ooze intervals. Inclination values fluctuate between the present-day value at the cores sites (-58°) and the geomagnetic axial dipole inclination

  1. [Public access defibrillation in the Sorrento Peninsula].

    PubMed

    Santomauro, Maurizio; Giordano, Raffaele; Poli, Vincenzo; Iaccarino, Vincenzo; Palagiano, Francesco; Matarazzo, Luigi; Langella, Giuseppina; Riganti, Carla; Vosa, Carlo

    2012-10-01

    Early cardiac defibrillation is the only effective therapy to stop ventricular fibrillation or pulseless ventricular tachycardia. It is still considered the gold standard for the treatment of ventricular tachycardia/fibrillation, and is the only intervention capable of improving survival in cardiac arrest survivors. Timing of intervention, however, is crucial because after only 10 min success rates are very low (0-2%). Unfortunately, adequate relief cannot always be provided within the necessary time. The purpose of the public access defibrillation project in Sorrento was to create fixed and mobile first aid with automated external defibrillators in combination with the local 118 emergency system. With the involvement of pharmacies, bathing establishments and schools, 31 equally distant sites for public access defibrillation were made available. This organization was supplemented by mobile units on the cars of the Municipal Police and Civil Protection, and on patrol boats in the harbor.

  2. Earthquake induced landslide hazard field observatory in the Avcilar peninsula

    NASA Astrophysics Data System (ADS)

    Bigarre, Pascal; Coccia, Stella; Theoleyre, Fiona; Ergintav, Semih; Özel, Oguz; Yalçinkaya, Esref; Lenti, Luca; Martino, Salvatore; Gamba, Paolo; Zucca, Francesco; Moro, Marco

    2015-04-01

    Earthquake-triggered landslides have an increasing disastrous impact in seismic regions due to the fast growing urbanization and infrastructures. Just considering disasters from the last fifteen years, among which the 1999 Chi-Chi earthquake, the 2008 Wenchuan earthquake, and the 2011 Tohoku earthquake, these events generated tens of thousands of coseismic landslides. Those resulted in amazing death toll and considerable damages, affecting the regional landscape including its hydrological main features. Despite a strong impetus in research during past decades, knowledge on those geohazards is still fragmentary, while databases of high quality observational data are lacking. These phenomena call for further collaborative researches aiming eventually to enhance preparedness and crisis management. The MARSITE project gathers research groups in a comprehensive monitoring activity developed in the Sea of Marmara Region, one of the most densely populated parts of Europe and rated at high seismic risk level since the 1999 Izmit and Duzce devastating earthquakes. Besides the seismic threat, landslides in Turkey and in this region constitute an important source of loss. The 6th Work Package of MARSITE project gathers 9 research groups to study earthquake-induced landslides focusing on two sub-regional areas of high interest among which the Cekmece-Avcilar peninsula, located westwards of Istanbul, as a highly urbanized concentrated landslide prone area, showing high susceptibility to both rainfalls while affected by very significant seismic site effects. A multidisciplinary research program based on pre-existing studies has been designed with objectives and tasks linked to constrain and tackle progressively some challenging issues related to data integration, modeling, monitoring and mapping technologies. Since the start of the project, progress has been marked on several important points as follows. The photogeological interpretation and analysis of ENVISAT-ERS DIn

  3. Coastal-Change and Glaciological Maps of the Antarctic Peninsula

    USGS Publications Warehouse

    Ferrigno, Jane G.; Williams, Richard S.; Thomson, Janet W.

    2002-01-01

    In 2000, the Glacier Studies Project (GSP) of the U.S. Geological Survey (USGS) and the Mapping and Geographic Information Centre (MAGIC) of the British Antarctic Survey (BAS) began a formal cooperative 3-year endeavor to prepare three maps of the Antarctic Peninsula region. The maps will be based on a large variety of cartographic, aerial photograph, satellite image, and ancillary historical datasets archived at each institution. The maps will document dynamic changes on the peninsula during the past 50 years. The three maps are part of a planned 24-map series (I-2600) being published by the USGS in both paper and digital format (see USGS Fact Sheet FS-050-98 at http://pubs.usgs.gov/factsheet/fs50-98/); the maps are of the Trinity Peninsula area (I-2600-A), the Larsen Ice Shelf area (I-2600-B), and the Palmer Land area (I-2600-C). The 1:1,000,000-scale maps will encompass an area 1,800 kilometers (km) long and with an average width of 400 km (range of 200 to 600 km wide); the area is between lats 60? and 76? S. and longs 52? and 80? W. Each of the three maps will include an interpretive booklet that analyzes documented historical changes in the fronts of the ice shelves and termini of the outlet glaciers.

  4. Mapping the HLA diversity of the Iberian Peninsula.

    PubMed

    Romòn, Iñigo; Montes, Carmen; Ligeiro, Dario; Trindade, Hélder; Sanchez-Mazas, Alicia; Nunes, José Manuel; Buhler, Stéphane

    2016-10-01

    The polymorphism of HLA genes can be used to reconstruct human peopling history. However, this huge diversity impairs successful matching in stem cell transplantation, a situation which has led to the recruitment of millions of donors worldwide. In parallel to the increase of recruitment, registries are progressively relying on information from population genetics to optimize their donor pools in terms of HLA variability. In this study, the HLA data of 65,000 Spanish bone marrow donors were analyzed together with 60,000 Portuguese individuals to provide a comprehensive HLA genetic map of the Iberian Peninsula. The frequencies of many alleles were shown to vary continuously across the Peninsula, either increasing or decreasing from the Mediterranean coast to the Atlantic domain or from the Strait of Gibraltar to the Pyrenees and Bay of Biscay. Similar patterns were observed for several haplotypes. In addition, within some regions neighboring provinces share a close genetic similarity. These results outline the genetic landscape of the Iberian Peninsula, and confirm that the analysis of the HLA polymorphism may reveal relevant signatures of past demographic events even when data from donor registries are used. This conclusion stimulates future developments of the Spanish registry, presented here for the first time. PMID:27377016

  5. Variation of seismic source parameters around the southern Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Rhee, H. M.; Sheen, D. H.; Kang, T. S.

    2014-12-01

    In this study, we determined seismic source parameters from 557 events with ML≥1.6 that occurred in the southern part of the Korean Peninsula from 2001 to 2013. A total of 7,267 S-wave trains on three-component seismograms recorded at broadband seismic stations were used for measuring the corner frequency, Brune stress drop and moment magnitude by using the iterative method of Jo and Baag (2001) based on the methods of Snoke (1987) and Andrews (1986). The SNR were calculated for each seismogram to exclude the possible contamination of the records by noise and/or instrumental malfunctioning. For the stable correction of attenuation, we tested several Q factors from the previous studies on those for the Korean Peninsula and found Kim (2007) gave the best result. In this study, as shown by Shi et al. (1998), the stress drop tended to decrease with decreasing seismic moment from the magnitude 3.5. Although there was large scatter in stress drop, however, the stress drops seemed to be constant for the larger events and the average stress drop was estimated to around 45.5 bar. It is interesting that there was a variation in stress drops depending on earthquake location: stress drops of the earthquakes occurred in the East Sea (Japan Sea) and the southwestern part of North Korea were relatively lower than those for the events occurred at other region in the southern Korean Peninsula.

  6. Preliminary assessment of aridity conditions in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Andrade, C.; Corte-Real, J. A.

    2016-06-01

    Aridity is one of the key elements characterizing the climate of a region, having a severe impact on human activities. Aiming at assessing aridity conditions in the Iberian Peninsula, the spatial distribution of the UNEP aridity index is analyzed during the period 1901-2012. Gridded precipitation and potential evapotranspiration datasets are used on a monthly basis. Results show that the southern half of Iberia is particularly vulnerable to water stress and hence to desertification processes. In particular, the UNEP aridity index reveals an increase and northward extension of the semi-arid regime in the Iberian Peninsula between 1901 and 2012. More than 50% of the north and western territory have experienced humid/sub-humid conditions, while the other regions underwent semi-arid settings. Results also reveal that climate was subjected to spatial and temporal variabilities with an overall statistically significant (at a 95% confidence level) trend to aridification in the south-easternmost and central regions. The remaining territory of the Iberian Peninsula does not reveal statistically significant trends.

  7. Glacial Geomorphic Characteristics of the Antarctic Peninsula Fjords

    NASA Astrophysics Data System (ADS)

    Wellner, J. S.; Munoz, Y. P.; Mead, K. A.; Hardin, L. A.

    2011-12-01

    A distinctive suite of subglacial geomorphic features, representing the grounding of an ice sheet and its subsequent retreat, has been well documented for many parts of the Antarctic continental shelf. Geomorphic features include meltwater channels, drumlins, mega-scale glacial lineations, and gullies cut into the upper slope. Many of these same features occur in more recently deglaciated fjords, but at different scales and in different combinations. We have surveyed twelve fjords on the Antarctic Peninsula, from the Graham Land Coast to Hope Bay as well as on Anvers Island and in the South Shetland Islands. Surveys include multibeam swath bathymetry, CHIRP 3.5 kHz seismic, and sediment cores. Recently, we have reprocessed much of the multibeam data using new software allowing higher-resolution imagery. Unlike on the outer continental shelf of the Antarctic Peninsula, where there is a relatively simple suite of geomorphic features and a uniform retreat history, the fjords on the inner shelf show a complex geomorphic pattern representing somewhat unique glacial retreat histories for each fjord. Several fjords have distinctive grounding zone wedge deposits, and some fjords have such wedges in multiple locations, representing multiple pauses in the retreat history, or a stepped retreat of the ice. Drumlins and mega-scale glacial lineations are present in the fjords, but extend for kms rather than the tens of kms that are typical of the outer shelf. If drumlins are interpreted to indicate acceleration of grounded ice, as they are on the outer shelf, then there must have been multiple zones of acceleration across the flow path of the ice as drumlin sets occur in multiple zones in a single flow path. The inner parts of many fjords along the coast of the peninsula are characterized by features interpreted as erosional meltwater channels, although such features are not common in fjords in the islands off the peninsula, despite the similar scale of the fjords themselves

  8. Status and distribution of the Kittlitz's Murrelet Brachyramphus brevirostris along the Alaska Peninsula and Kodiak and Aleutian Islands, Alaska

    USGS Publications Warehouse

    Madison, Erica N.; Piatt, John F.; Arimitsu, Mayumi L.; Romano, Marc D.; van Pelt, Thomas I.; Nelson, S. Kim; Williams, Jeffrey C.; DeGange, Anthony R.

    2011-01-01

    The Kittlitz's Murrelet Brachyramphus brevirostris is adapted for life in glacial-marine ecosystems, being concentrated in the belt of glaciated fjords in the northern Gulf of Alaska from Glacier Bay to Cook Inlet. Most of the remaining birds are scattered along coasts of the Alaska Peninsula and Aleutian Islands, where they reside in protected bays and inlets, often in proximity to remnant glaciers or recently deglaciated landscapes. We summarize existing information on Kittlitz's Murrelet in this mainly unglaciated region, extending from Kodiak Island in the east to the Near Islands in the west. From recent surveys, we estimated that ~2400 Kittlitz's Murrelets were found in several large embayments along the Alaska Peninsula, where adjacent ice fields feed silt-laden water into the bays. On Kodiak Island, where only remnants of ice remain today, observations of Kittlitz's Murrelets at sea were uncommon. The species has been observed historically around the entire Kodiak Archipelago, however, and dozens of nest sites were found in recent years. We found Kittlitz's Murrelets at only a few islands in the Aleutian chain, notably those with long complex shorelines, high mountains and remnant glaciers. The largest population (~1600 birds) of Kittlitz's Murrelet outside the Gulf of Alaska was found at Unalaska Island, which also supports the greatest concentration of glacial ice in the Aleutian Islands. Significant populations were found at Atka (~1100 birds), Attu (~800) and Adak (~200) islands. Smaller numbers have been reported from Unimak, Umnak, Amlia, Kanaga, Tanaga, Kiska islands, and Agattu Island, where dozens of nest sites have been located in recent years. Most of those islands have not been thoroughly surveyed, and significant pockets of Kittlitz's Murrelets may yet be discovered. Our estimate of ~6000 Kittlitz's Murrelets along the Alaska Peninsula and Aleutian Islands is also likely to be conservative because of the survey protocols we employed (i.e. early

  9. Slab window migration and terrane accretion preserved by low-temperature thermochronology of a magmatic arc, northern Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Guenthner, William R.; Barbeau, David L.; Reiners, Peter W.; Thomson, Stuart N.

    2010-03-01

    Existing paleogeographic reconstructions indicate that the northern Antarctic Peninsula was central to several Mesozoic and Cenozoic tectonic events that have implications for ocean circulation and continental margin evolution. To evaluate the exhumational record of these processes, we collected new samples and measured fission track and (U-Th)/He cooling ages of apatite and zircon from 13 Jurassic and Cretaceous granitoids in western Graham Land between the northern tip of the peninsula and the Antarctic Circle. Apatite He data reveal distinct ages and systematic age patterns north and south of Anvers Island, near the midpoint of the study area: To the south, apatite He ages range from 16 to 8 Ma and young northward, whereas to the north they range between 65 and 24 Ma (with one exception at 11 Ma) and young southward. Thermal histories inferred from the ages and closure temperatures of multiple thermochronometers in single samples indicate distinct histories for northern and southern Graham Land. Northern sites reveal a Late Cretaceous pulse of rapid cooling (>7°C/Myr) followed by very slow cooling (˜1°C/Myr) to the Recent, whereas southern sites record either a pulse of rapid mid-Miocene cooling (˜8°C/Myr) or steady and moderate cooling (˜3°C/Myr) from the Late Cretaceous to the Recent. We interpret the Late Cretaceous rapid cooling in the northern part of the study area as a possible manifestation of terrane accretion associated with the Palmer Land event. We interpret the systematic spatial trends in apatite He ages and contrasting thermal histories along the peninsula as recording progressive Late Cenozoic northward opening of a slab window south of Anvers Island. This is consistent with a time transgressive pulse of ˜2-3 km of rock uplift and exhumation in the upper plate following ridge-trench collision, cessation of subduction, and opening of the slab window, presumably caused by increased asthenospheric upwelling beneath the overriding plate.

  10. Soils and landforms from Fildes Peninsula and Ardley Island, Maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Michel, Roberto F. M.; Schaefer, Carlos E. G. R.; López-Martínez, Jerónimo; Simas, Felipe N. B.; Haus, Nick W.; Serrano, Enrique; Bockheim, James G.

    2014-11-01

    Fildes Peninsula (F.P.) and Ardley Island (A.I.) are among the first ice-free areas in Maritime Antarctica. Since the last glacial retreat in this part of Antarctica (8000 to 5000 years BP), the landscape in these areas evolved under paraglacial to periglacial conditions, with pedogenesis marked by cryogenic processes. We carried out a detailed soil and geomorphology survey, with full morphological and analytical description for both areas; forty-eight soil profiles representing different landforms were sampled, analyzed and classified according to the U.S. Soil Taxonomy and the World Reference Base for Soil Resources (WRB). Soils are mostly turbic, moderately developed, with podzolization and strong phosphatization (chemical weathering of rock minerals and formation of amorphous Al and Fe minerals) in former ornithogenic sites while in areas with poor vegetation show typical features of cryogenic weathering. Nivation, solifluction, cryoturbation, frost weathering, ablation and surface erosion are widespread. The most represented landform system by surface in Fildes Peninsula is the periglacial one, and 15 different periglacial landforms types have been identified and mapped. These features occupy about 30% of the land surface, in which patterned ground and stone fields are the most common landforms. Other significant landforms as protalus lobes, rock glaciers or debris lobes indicate the extensive presence of permafrost. Soil variability was high, in terms of morphological, physical and chemical properties, due to varying lithic contributions and mixing of different rocks, as well as to different degrees of faunal influence. Three soil taxonomy orders were identified, whereas thirty four individual pedons were differentiated. Fildes Peninsula experiences a south-north gradient from periglacial to paraglacial conditions, and apparently younger soils and landforms are located close to the Collins Glacier. Arenosols/Entisols and Cryosols/Gelisols (frequently

  11. Comparison of multi-proxy data with past1000 model output over the Terminal Classic Period (800-1000 A.D.) on the Yucatan Peninsula.

    NASA Astrophysics Data System (ADS)

    Van Pelt, S.; Kohfeld, K. E.; Allen, D. M.

    2015-12-01

    The decline of the Mayan Civilization is thought to be caused by a series of droughts that affected the Yucatan Peninsula during the Terminal Classic Period (T.C.P.) 800-1000 AD. The goals of this study are two-fold: (a) to compare paleo-model simulations of the past 1000 years with a compilation of multiple proxies of changes in moisture conditions for the Yucatan Peninsula during the T.C.P. and (b) to use this comparison to inform the modeling of groundwater recharge in this region, with a focus on generating the daily climate data series needed as input to a groundwater recharge model. To achieve the first objective, we compiled a dataset of 5 proxies from seven locations across the Yucatan Peninsula, to be compared with temperature and precipitation output from the Community Climate System Model Version 4 (CCSM4), which is part of the Coupled Model Intercomparison Project Phase 5 (CMIP5) past1000 experiment. The proxy dataset includes oxygen isotopes from speleothems and gastropod/ostrocod shells (11 records); and sediment density, mineralogy, and magnetic susceptibility records from lake sediment cores (3 records). The proxy dataset is supplemented by a compilation of reconstructed temperatures using pollen and tree ring records for North America (archived in the PAGES2k global network data). Our preliminary analysis suggests that many of these datasets show evidence of drier and warmer climate on the Yucatan Peninsula around the T.C.P. when compared to modern conditions, although the amplitude and timing of individual warming and drying events varies between sites. This comparison with modeled output will ultimately be used to inform backward shift factors that will be input to a stochastic weather generator. These shift factors will be based on monthly changes in temperature and precipitation and applied to a modern daily climate time series for the Yucatan Peninsula to produce a daily climate time series for the T.C.P.

  12. An annotated checklist of the Chilopoda and Diplopoda (Myriapoda) of the Abrau Peninsula, northwestern Caucasus, Russia

    PubMed Central

    Semenyuk, Irina I.; Tuf, Ivan H.

    2016-01-01

    Abstract Background The Abrau Peninsula is located in northwestern Caucasus between the cities of Novorossiysk and Anapa, Krasnodar Province, Russia. This paper contains an annotated checklist of the Chilopoda and Diplopoda inhabiting the Abrau Peninsula. New information The fauna of the Abrau Peninsula comprises 17 centipede (4 orders) and 16 millipede (6 orders) species. Henia taurica, hitherto known only from the Crimea, has now been reported from several localities in the studied region. The study also reveals two possibly new millipede species. Statistical analyses showed that habitat preferences of myriapod species within the Abrau Peninsula are caused by species geographic distribution pattern and microbiotope preferences. PMID:27346949

  13. Quantitative distribution and functional groups of intertidal macrofaunal assemblages in Fildes Peninsula, King George Island, South Shetland Islands, Southern Ocean.

    PubMed

    Liu, Xiaoshou; Wang, Lu; Li, Shuai; Huo, Yuanzi; He, Peimin; Zhang, Zhinan

    2015-10-15

    To evaluate spatial distribution pattern of intertidal macrofauna, quantitative investigation was performed in January to February, 2013 around Fildes Peninsula, King George Island, South Shetland Islands. A total of 34 species were identified, which were dominated by Mollusca, Annelida and Arthropoda. CLUSTER analysis showed that macrofaunal assemblages at sand-bottom sites belonged to one group, which was dominated by Lumbricillus sp. and Kidderia subquadrata. Macrofaunal assemblages at gravel-bottom sites were divided into three groups while Nacella concinna was the dominant species at most sites. The highest values of biomass and Shannon-Wiener diversity index were found in gravel sediment and the highest value of abundance was in sand sediment of eastern coast. In terms of functional group, detritivorous and planktophagous groups had the highest values of abundance and biomass, respectively. Correlation analysis showed that macrofaunal abundance and biomass had significant positive correlations with contents of sediment chlorophyll a, phaeophorbide and organic matter.

  14. Human activities impact on mountain river channels (case study of Kamchatka peninsula rivers)

    NASA Astrophysics Data System (ADS)

    Ermakova, Aleksandra S.

    2010-05-01

    Human-induced driving factors along with natural environmental changes greatly impact on fluvial regime of rivers. On mountain and semi-mountain territories these processes are developed in the most complicated manner due to man-made activities diversity throughout river basins. Besides these processes are significantly enhanced because of the disastrous natural processes (like volcanic and mud-flow activity) frequent occurrences in mountainous regions. On of the most striking example on the matter is Kamchatka peninsula which is located at the North-West part of Russian Federation. This paper contributes to the study of human activities impact on fluvial systems in this volcanic mountain region. Human effects on rivers directly alter channel morphology and deformations, dynamics of water and sediment movement, aquatic communities or indirectly affect streams by altering the movement of water and sediment into the channel. In case study of Kamchatka peninsula human activities affect fluvial systems through engineering works including construction of bridges, dams and channel diversions and placer mining. These processes are characterized by spatial heterogeneity because of irregular population distribution. Due to specific natural conditions of the peninsula the most populated areas are the valleys of big rivers (rivers Kamchatka, Avacha, Bistraya (Bolshaya), etc) within piedmont and plain regions. These rivers are characterized by very unstable channels. Both with man-made activities this determines wide range of fluvial system changes. Firstly bridges construction leads to island and logjam formation directly near their piers and intensification of channels patterns shifts. Furthermore rivers of the peninsula are distinguished for high water flow velocities and water rate. Incorrect bridge constructions both with significant channel deformations lead to the destructions of the bridges themselves due to intensive bank erosion. Secondly, intensive water flow

  15. Variability on the Hypoxic Conditions in the Northwestern Region of the Baja California Peninsula

    NASA Astrophysics Data System (ADS)

    Bustos-Serrano, H.

    2015-12-01

    The NW region of the Baja California peninsula in México is dominated by the California Current System (CCS). Dissolved oxygen (DO) is a key variable in water bodies because it is considered as a health in biological processes. Hypoxic conditions (DO 60 to 120 μmol kg-1) occur naturally in large areas of the ocean. In the Eastern Pacific, the DO can be altered by eutrophication, derived from anthropogenic activity, especially in shallow and enclosed seas. Fluctuations in the conditions of hypoxia zones may have significant ecological and economic impact. It is of interest in assessing whether hypoxic conditions in the vicinity of Bahia de Todos Santos (BTS) and Coronado Islands in México are altered by anthropogenic activity (Figs. 1 and 2 respectively). For the present study, we worked with data collected from oceanographic expeditions during the period October 2010 to June 2015. The DO was determined using a CTD (SBE Model 25) and by sea water collection with hydrographic bottles using a modification of the Winkler method. The signs of hypoxia are evident in the area near BTS and in the vicinity of Coronado´s Islands, mainly on locations between the Todos Santos Islands and the peninsula of Punta Banda, which shows that the hypoxic zone begins to occur in shallow water between 50-200 m depth. This particular area corresponds to the point where the Mexican Navy determined as a site for dredging materials from the ports of Ensenada and El Sauzal, it is possible that the anthropogenic activity alters the natural conditions of hypoxia in the area to enlarge. In June 2012 for the first time in that region we obtained sediment samples below 700 m depth, which are mixed terrigenous clastic and oceanic sediments.

  16. Forest response to increasing typhoon activity on the Korean peninsula: evidence from oak tree-rings.

    PubMed

    Altman, Jan; Doležal, Jiří; Cerný, Tomáš; Song, Jong-Suk

    2013-02-01

    The globally observed trend of changing intensity of tropical cyclones over the past few decades emphasizes the need for a better understanding of the effects of such disturbance events in natural and inhabited areas. On the Korean Peninsula, typhoon intensity has increased over the past 100 years as evidenced by instrumental data recorded from 1904 until present. We examined how the increase in three weather characteristics (maximum hourly and daily precipitation, and maximum wind speed) during the typhoon activity affected old-growth oak forests. Quercus mongolica is a dominant species in the Korean mountains and the growth releases from 220 individuals from three sites along a latitudinal gradient (33-38°N) of decreasing typhoon activity were studied. Growth releases indicate tree-stand disturbance and improved light conditions for surviving trees. The trends in release events corresponded to spatiotemporal gradients in maximum wind speed and precipitation. A high positive correlation was found between the maximum values of typhoon characteristics and the proportion of trees showing release. A higher proportion of disturbed trees was found in the middle and southern parts of the Korean peninsula where typhoons are most intense. This shows that the releases are associated with typhoons and also indicates the differential impact of typhoons on the forests. Finally, we present a record of the changing proportion of trees showing release based on tree-rings for the period 1770-1979. The reconstruction revealed no trend during the period 1770-1879, while the rate of forest disturbances increased rapidly from 1880 to 1979. Our results suggest that if typhoon intensity rises, as is projected by some climatic models, the number of forest disturbance events will increase thus altering the disturbance regime and ecosystem processes.

  17. Soil-landform-plant communities relationships of a periglacial landscape at Potter Peninsula, Maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Poelking, E. L.; Schaefer, C. E. R.; Fernandes Filho, E. I.; de Andrade, A. M.; Spielmann, A. A.

    2014-08-01

    Integrated studies on the interplay between soils, periglacial geomorphology and plant communities are crucial for the understanding of climate change effects on terrestrial ecosystems of Maritime Antarctica, one of the most sensitive areas to global warming. Knowledge on physical environmental factors that influence plant communities can greatly benefit studies on monitoring climate change in Maritime Antarctica, where new ice-free areas are being constantly exposed, allowing plant growth and organic carbon inputs. The relationship between topography, plant communities and soils was investigated in Potter Peninsula, King George Island, Maritime Antarctica. We mapped the occurrence and distribution of plant communities and identified soil-landform-vegetation relationships. The vegetation map was obtained by classification of a Quickbird image, coupled with detailed landform and characterization of 18 soil profiles. The sub-formations were identified and classified, and we also determined the total elemental composition of lichens, mosses and grasses. Plant communities at Potter Peninsula occupy 23% of the ice-free area, at different landscape positions, showing decreasing diversity and biomass from the coastal zone to inland areas where sub-desert conditions prevail. There is a clear dependency between landform and vegetated soils. Soils with greater moisture or poorly drained, and acid to neutral pH, are favourable for mosses subformations. Saline, organic-matter rich ornithogenic soils of former penguin rookeries have greater biomass and diversity, with mixed associations of mosses and grasses, while stable felseenmeers and flat rocky cryoplanation surfaces are the preferred sites for Usnea and Himantormia lugubris lichens, at the highest surface. Lichens subformations cover the largest vegetated area, showing varying associations with mosses.

  18. Subglacial morphology and glacial evolution of the Palmer deep outlet system, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Domack, Eugene; Amblàs, David; Gilbert, Robert; Brachfeld, Stefanie; Camerlenghi, Angelo; Rebesco, Michele; Canals, Miquel; Urgeles, Roger

    2006-04-01

    The Palmer Deep is an erosional, inner-shelf trough located at the convergence of ice flow from three distinct accumulation centers. It served as a funnel for ice flow out across the continental shelf of the Antarctic Peninsula. Swath mapping of 1440 km 2 of seafloor in and adjacent to the Palmer Deep basin defines a large paleo-ice stream that flowed 230 km across the Antarctic Peninsula continental shelf during the Last Glacial Maximum (MIS-2). The unique perspective and detail of the Palmer Deep physiography allow us to recognize several phases of erosion and deposition in the outlet basin. These events are uniquely constrained by two ODP drill cores (sites 1099 and 1098) that together recovered over 150 m of latest Pleistocene and Holocene sediment. We divide this region of the continental shelf into three zones based upon mega- to meso-scale bathymetric features and emphasize that all three were part of one glacial outlet during the most recent period of glaciation. These zones include from inner shelf to outer shelf: the Palmer Deep basin, the Palmer Deep Outlet Sill and the Hugo Island Trough. Specific seafloor features associated with these zones include: relict terraces, sub-glacial lake deltas, channels and levees, debris slopes, spindle and out bed forms, mega-scale glacial lineations, morainal banks, and bank breach points. The origin of many of these features can be linked to the development of a sub-glacial lake basin within the Palmer Deep during or prior to MIS-2, its subsequent drainage, and recession of the Palmer Deep ice stream system. This sub-glacial lake system is reconstructed at the head of a major paleo-ice stream.

  19. Preliminary Geochemical and Rock Magnetic Study of a Stalagmite From Quintana Roo, Northeastern Yucatan Peninsula

    NASA Astrophysics Data System (ADS)

    Urrutia-Fucugauchi, J.; Perez-Cruz, L.; Zhao, X.; Rebolledo-Vieyra, M.; Rodriguez, A.

    2012-04-01

    We present the preliminary results of geochemical, stable isotopes and rock magnetic studies of a stalagmite from a cave in eastern Quintana Roo, northern Yucatan peninsula. In the past years, there has been increased interest in understanding the paleoclimatic and paleoenvironmental evolution of the Yucatan peninsula and northern Central America, investigating the relationships between climate variations and the development of the Maya civilization. In particular, the variations in regional precipitation and occurrence of several drought periods, which might have been related to the collapse of the Classic Maya period. Stable isotope data on speleothems from different sites in Yucatan and Central America have provided evidence on changes in precipitation, which have affected the Maya region. The stalagmite is ~47 cm long and about 4-5 cm wide at its base. It was collected from the Hilariós Well cave in Tulum, Quintana Roo. Magnetic susceptibility and geochemical analyses have been completed as part of the initial characterization of the stalagmite, with measurements taken every centimeter. Geochemical analyses have been carried out for x-ray fluorescence, with a Niton XRF analyzer. Magnetic susceptibility was determined with a Bartington MS2 instrument using the high resolution surface probe. Additional rock magnetic analyses include magnetic hysteresis loops and isothermal remanent magnetization (IRM) acquisition, and saturation IRM demagnetization, which have been measured with a MicroMag instrument. Hysteresis loops are diamagnetic, with small varying low-coercivity ferromagnetic components. The elemental compositions of major oxides and trace elements vary with depth. Calcium is the major element and displays a pattern of small amplitude fluctuations with a trend to lower values at the bottom, which are also shown in other elements such as barium. Silica and elements such as titanium and strontium are positively correlated and show an apparent cyclic pattern

  20. Soil-landform-plant-community relationships of a periglacial landscape on Potter Peninsula, maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Poelking, E. L.; Schaefer, C. E. R.; Fernandes Filho, E. I.; de Andrade, A. M.; Spielmann, A. A.

    2015-05-01

    Integrated studies on the interplay between soils, periglacial geomorphology and plant communities are crucial for the understanding of climate change effects on terrestrial ecosystems of maritime Antarctica, one of the most sensitive areas to global warming. Knowledge on physical environmental factors that influence plant communities can greatly benefit studies on the monitoring of climate change in maritime Antarctica, where new ice-free areas are being constantly exposed, allowing plant growth and organic carbon inputs. The relationship between topography, plant communities and soils was investigated on Potter Peninsula, King George Island, maritime Antarctica. We mapped the occurrence and distribution of plant communities and identified soil-landform-vegetation relationships. The vegetation map was obtained by classification of a QuickBird image, coupled with detailed landform and characterization of 18 soil profiles. The sub-formations were identified and classified, and we also determined the total elemental composition of lichens, mosses and grasses. Plant communities on Potter Peninsula occupy 23% of the ice-free area, at different landscape positions, showing decreasing diversity and biomass from the coastal zone to inland areas where sub-desert conditions prevail. There is a clear dependency between landform and vegetated soils. Soils that have greater moisture or are poorly drained, and with acid to neutral pH, are favourable for moss sub-formations. Saline, organic-matter-rich ornithogenic soils of former penguin rookeries have greater biomass and diversity, with mixed associations of mosses and grasses, while stable felsenmeers and flat rocky cryoplanation surfaces are the preferred sites for Usnea and Himantormia lugubris lichens at the highest surface. Lichens sub-formations cover the largest vegetated area, showing varying associations with mosses.

  1. Dust Optical Properties Over North Africa and Arabian Peninsula Derived from the AERONET Dataset

    NASA Technical Reports Server (NTRS)

    Kim, D.; Chin, M.; Yu, H.; Eck, T. F.; Sinyuk, A.; Smirnov, A.; Holben, B. N.

    2011-01-01

    Dust optical properties over North Africa and the Arabian Peninsula are extracted from the quality assured multi-year datasets obtained at 14 sites of the Aerosol Robotic Network (AERONET). We select the data with (a) large aerosol optical depth (AOD >= 0.4 at 440 nm) and (b) small Angstrom exponent (A(sub ext)<= 0.2) for retaining high accuracy and reducing interference of non-dust aerosols. The result indicates that the major fraction of high aerosol optical depth days are dominated by dust over these sites even though it varies depending on location and time. We have found that the annual mean and standard deviation of single scattering albedo, asymmetry parameter, real refractive index, and imaginary refractive index for Saharan and Arabian desert dust is 0.944 +/- 0.005, 0.752 +/- 0.014, 1.498 +/- 0.032, and 0.0024 +/- 0.0034 at 550 nm wavelength, respectively. Dust aerosol selected by this method is less absorbing than the previously reported values over these sites. The weaker absorption of dust from this study is consistent with the studies using remote sensing techniques from satellite. These results can help to constrain uncertainties in estimating global dust shortwave radiative forcing.

  2. Compliance with Wetland Mitigation Standards in the Upper Peninsula of Michigan, USA

    NASA Astrophysics Data System (ADS)

    Kozich, Andrew T.; Halvorsen, Kathleen E.

    2012-07-01

    The United States has lost about half its wetland acreage since European settlement, and the effectiveness of current wetland mitigation policies is often questioned. In most states, federal wetland laws are overseen by the U.S. Army Corps of Engineers, but Michigan administers these laws through the state's Department of Environmental Quality (MDEQ). Our research provides insight into the effectiveness of the state's implementation of these laws. We examined wetland mitigation permit files issued in Michigan's Upper Peninsula between 2003 and 2006 to assess compliance with key MDEQ policies. Forty-six percent of files were out of compliance with monitoring report requirements, and forty-nine percent lacked required conservation easement documents. We also conducted site assessments of select compensatory wetland projects to determine compliance with MDEQ invasive plant species performance standards. Fifty-five percent were out of compliance. We found no relationship between invasive species noncompliance and past site monitoring, age of mitigation site, or proximity to roads. However, we found wetland restoration projects far more likely to be compliant with performance standards than wetland creation projects. We suggest policy changes and agency actions that could increase compliance with wetland restoration and mitigation goals.

  3. Compliance with wetland mitigation standards in the upper peninsula of Michigan, USA.

    PubMed

    Kozich, Andrew T; Halvorsen, Kathleen E

    2012-07-01

    The United States has lost about half its wetland acreage since European settlement, and the effectiveness of current wetland mitigation policies is often questioned. In most states, federal wetland laws are overseen by the U.S. Army Corps of Engineers, but Michigan administers these laws through the state's Department of Environmental Quality (MDEQ). Our research provides insight into the effectiveness of the state's implementation of these laws. We examined wetland mitigation permit files issued in Michigan's Upper Peninsula between 2003 and 2006 to assess compliance with key MDEQ policies. Forty-six percent of files were out of compliance with monitoring report requirements, and forty-nine percent lacked required conservation easement documents. We also conducted site assessments of select compensatory wetland projects to determine compliance with MDEQ invasive plant species performance standards. Fifty-five percent were out of compliance. We found no relationship between invasive species noncompliance and past site monitoring, age of mitigation site, or proximity to roads. However, we found wetland restoration projects far more likely to be compliant with performance standards than wetland creation projects. We suggest policy changes and agency actions that could increase compliance with wetland restoration and mitigation goals. PMID:22543680

  4. Cenozoic evolution of the Antarctic Peninsula continental margin

    SciTech Connect

    Anderson, J.B. )

    1990-05-01

    Cenozoic evolution of the Antarctic Peninsula continental margin has involved a series of ridge (Aluk Ridge)-trench collisions between the Pacific and Antarctic plates. Subduction occurred episodically between segments of the Pacific plate that are bounded by major fracture zones. The age of ridge-trench collisions decreases from south to north along the margin. The very northern part of the margin, between the Hero and Shackleton fracture zones, has the last surviving Aluk-Antarctic spreading ridge segments and the only remaining trench topography. The sedimentary cover on the northern margin is relatively thin generally less than 1.5 km, thus providing a unique setting in which to examine margin evolution using high resolution seismic methods. Over 5,000 km of high resolution (water gun) seismic profiles were acquired from the Antarctic Peninsula margin during four cruises to the region. The margin is divided into discrete fracture-zone-bounded segments; each segment displays different styles of development. Highly tectonized active margin sequences have been buried beneath a seaward-thickening sediment wedge that represents the passive stage of margin development Ice caps, which have existed in the Antarctic Peninsula region since at least the late Oligocene, have advanced onto the continental shelf on numerous occasions, eroding hundreds of meters into the shelf and depositing a thick sequence of deposits characterized by till tongues and glacial troughs. Glacial erosion has been the main factor responsible for overdeepening of the shelf; isostasy is of secondary importance. As the shelf was lowered by glacial erosion, it was able to accommodate thicker and more unstable marine ice sheets. The shelf also became a vast reservoir for cold, saline shelf water, one of the key ingredients of Antarctic bottom water.

  5. Spatiotemporal variations in the surface velocities of Antarctic Peninsula glaciers

    NASA Astrophysics Data System (ADS)

    Chen, J.; Ke, C. Q.; Shao, Z. D.

    2014-11-01

    Velocity is an important parameter for the estimation of glacier mass balance, which directly signals the response of glaciers to climate change. Antarctic ice sheet movement and the associated spatiotemporal velocity variations are of great significance to global sea level rise. In this study, we estimate Antarctic Peninsula glacier velocities using the co-registration of optically sensed images and correlation (hereafter referred to as COSI-Corr) based on moderate-resolution imaging spectroradiometer Level 1B data (hereafter referred to as MODIS L1B). The results show that the glaciers of Graham Land and the Larsen Ice Shelf have substantially different velocity features. The Graham Land glaciers primarily flow from the peninsula ridge towards the Weddell Sea and Bellingshausen Sea on the east and west sides, respectively. There are very large velocity variations among the different ice streams, with a minimum of < 20 m a-1 and a maximum of 1500 m a-1 (with an average of 100-150 m a-1). Over the period 2000-2012, the glaciers of Graham Land accelerated in the south but slowed down in the north. In contrast, the Larsen Ice Shelf flows in a relatively uniform direction, mainly towards the northeast into the Weddell Sea. Its average velocity is 750-800 m a-1 and the maximum is > 1500 m a-1. During the period 2000-2012, the Larsen Ice Shelf experienced significant acceleration. The use of COSI-Corr based on MODIS L1B data is suitable for glacier velocity monitoring on the Antarctic Peninsula over long time series and large spatial scales. This method is clearly advantageous for analysing macro-scale spatiotemporal variations in glacier movement.

  6. Permian Tethyan Fusulinina from the Kenai Peninsula, Alaska

    USGS Publications Warehouse

    Stevens, C.H.; Davydov, V.I.; Bradley, D.

    1997-01-01

    Two samples from a large, allochthonous limestone block in the McHugh Complex of the Chugach terrane on the Kenai Peninsula, Alaska, contain species of 12 genera of Permian Fusulinina including Abadehella, Kahlerina, Pseudokahlerina?, Nankinella, Codonofusiella, Dunbarula, Parafusulina?, Chusenella, Verbeekina, Pseudodoliolina, Metadoliolina?, Sumatrina?, and Yabeina, as well as several other foraminiferans and one alga. The assemblage of fusulinids is characteristically Tethyan, belonging to the Yabeina archaica zone of early Midian (late Wordian) age. Similar faunas are known from the Pamirs, Transcaucasia, and Japan, as well as from allochthonous terranes in British Columbia, northwestern Washington, and Koryakia in eastern Siberia.

  7. Late Cenozoic stress field distribution in Biga Peninsula, NW Turkey

    NASA Astrophysics Data System (ADS)

    Ozden, S.; Bekler, T.; Tutkun, S. Z.; Kurcer, A.; Ates, O.; Bekler, F. N.; Kalafat, D.

    2009-04-01

    Biga Peninsula is a seismically active region both in instrumental and historical period in NW Turkey. In this part, middle and southern branches of North Anatolian Fault are represented by Etili, Can-Biga, Yenice-Gonen, Manyas-Danisment, Lapseki, Sinekci, Terzialan, Dogruca, Uluabat, Edincik, Pazarkoy-Hamdibey-Kalkim, Edremit, Yigitler, Sarikoy-Inova, Troia and Karabiga Faults. All of these faults are responsible of the seismic activity in Biga Peninsula. Historical earthquakes happened in 29, 155, 170, 543, 620, 1440, 1737, 1855, 1865 and 1875. Furthermore, as for instrumental period, Saros Gulf-Murefte earthquakes (M:7.3 and M:6.3) in 1912, Erdek Gulf (M:6.4) and Can-Biga (M:6.3) in 1935, Edremit Gulf-Ayvaci k (M:6.8) in 1944, Yenice-Gonen (M:7.2) in 1953, Gonen (M:5.8) in 1964, Edremit-Baki rcay (M:5.5) in 1971, Biga (M:5.8) in 1983, Kusgolu-Manyas (M:5.2) and Bandirma (M:5.0) in 2006. In this study, we determined the Late Cenozoic stress field distribution and present-day tectonic regimes both fault-slip data (by 253 fault planes) and earthquake focal mechanism solutions (by 58 earthquakes) were investigated by the inversion methods. The results indicate that a transtensional stress regime is dominant with a NW-SE to WNW-ESE directed compression (1) and NE-SW to ENE-WSW directed extension (3), which yielded a NE-SW, ENE-WSW and also E-W trending strike-slip faulting faults with a normal component. While a transtensional tectonic regime has an active component in Biga Peninsula, a local and consistent transpressional tectonic regime were determined along an E-W trending narrow zone in the northern part of the Biga Peninsula also. The tectonic regime and stress field is resulted from interactions both continental collision of Eurasian/Anatolian/Arabian plate in the east and subduction processes (roll back and/or slab-pull) of the African plate along the Cyprus and Hellenic arc in the Mediterranean region.

  8. Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula.

    PubMed

    Koo, Kyung Ah; Kong, Woo-Seok; Nibbelink, Nathan P; Hopkinson, Charles S; Lee, Joon Ho

    2015-01-01

    Climate change has caused shifts in species' ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine

  9. Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula

    PubMed Central

    Koo, Kyung Ah; Kong, Woo-Seok; Nibbelink, Nathan P.; Hopkinson, Charles S.; Lee, Joon Ho

    2015-01-01

    Climate change has caused shifts in species’ ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine

  10. Monitoring of Landslides using Repeated Kinematics GPS Observables in Sevketiye Town, Biga Peninsula, Çanakkale, NW Turkey

    NASA Astrophysics Data System (ADS)

    Cuneyt Erenoglu, Ramazan; Akcay, Ozgun; Karaca, Zeki; Erenoglu, Oya; Sengul Uluocak, Ebru; Yucel, Mehmet Ali

    2014-05-01

    Landslide is one of the most important natural events, and is also a result of earth's crust movements. Landslides generally result in the outward and downward movement of slope-forming materials consisting soil, rock, artificial fill and etc. Moreover, possible earthquakes are one of the main reasons of triggering landslides in active areas seismically. There have been many studies based on the Global Positioning System (GPS) observables to compute the three dimensional positioning of established sites, and to model landslides precisely. We can monitor landslide with GPS using continuous data collection or the type of campaign surveying. While continuous data collection provide a millimetre-level of accuracy, the accuracy decreases with the shorter sessions, e.g. campaign surveying, due to possible sources of error. The area, located west of the Çanakkale, has been studied to identify the landslide susceptibility and geology. Çanakkale, NW Turkey, is located on the territory of the Biga Peninsula and the Gallipoli Peninsula. The section of remaining at the west of the line from the Gulf of Edremit to the Gulf of Erdek is called Biga Peninsula, and it covers an area of approximately 10 thousand km². In the Biga Peninsula, the main morphological units are at the western, northern and southern of coastal plains, and on their behind the hills, plateaus and mountainous areas of the inland. But at the middle areas, it is often possible to find the tectonic depressions sandwiched between the masses plateau and mountainous. In general, moving down the slope of a rock, soil or debris can be defined as landslides that are ranks second in terms of caused losses after earthquakes in Turkey. Landslides, harm to urbanization as well as loss of lives and economic losses. Moreover they adversely affects to agricultural, forest areas and the quality of the rivers. For example, the gas pipeline connecting Turkey and Greece, which will provide gas to the Southern Europe passes

  11. New Paleoseismological Finding on the Yenice Gönen Fault; Biga Peninsula, NW Turkey

    NASA Astrophysics Data System (ADS)

    Kürçer, Akın; Özalp, Selim; Özdemir, Ersin; Sönmez, Özgül; Duman, Tamer Y.

    2014-05-01

    The North Anatolian Fault System (NAFS) is one of the major intra-continental transform faults in the Eastern Mediterranean region. It is an active dextral strike-slip fault zone extends more than 1500 km-long forming northern boundary of the Anatolian microplate. East of Marmara Sea it divides into the northern and southern strands running towards the northern Aegean sea. The southern strand of the NAFS is consists of several fault segments, which trend NE-SW in the Biga Peninsula. Yenice-Gönen Fault (YGF) is one of the main fault segment of the NAFS in Biga Peninsula. It is about 70 km long and generated destructive earthquake (Mw=7.2) of 18th March, 1953. In this study, paleoseismological investigations were performed on the YGF. It is composed of fault sections separated from each other by releasing and/or restraining bends or step-overs. The lengths of the fault sections vary from 5 to 19 km. The whole length of the YGF ruptured with maximum dextral slip of 4.0 m measured on the surface rupture nearby Yenice Town. The amount of slips decrees both NE and SW from Yenice town indicating bilateral rupture propagation. There is no clear consistency between the previously suggested epicentre location and the slip distributions. According to the slip observations, the epicentre of the 1953 event locates to the near east of the Yenice. In order to understand paleoseismic history of the YGF, three cross trenches were excavated on the 1953 surface rupture. Two of them are on the distal part of an alluvial fan at Seyvan village and one of them is on the flood plain of the Yenice River at Çakır village. 1953 surface rupture is characterized by an evident of linear fresh fault scarp around Seyvan. Fault scarps are obvious with an uplifted of 1.2 m southern block. Dextral slip of 2.5 meter associated with the last event was measured along the rupture near the Seyvan trench site. Although active river erosion, the rupture trace can be easily followed in the field at the

  12. ABCGheritage project - promoting geotourism in northern Finland, northern Norway and the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Pihlaja, Jouni; Johansson, Peter; Lauri, Laura S.

    2014-05-01

    Nature tourism has been a growing business sector in the Barents area during the recent decades. With the purpose to develop nature tourism in a sustainable way, a cooperation project ABCGheritage - Arctic Biological, Cultural and Geological Heritage has been carried out. Project has received partial funding from the EU Kolarctic ENPI program. In the geoheritage part of the project the main activities were aimed to develop pro-environmental ways of geotourism in the area. The three main participants in the geoheritage part of the project are the Geological Survey of Finland, Northern Finland Office, the Geological Institute of the Kola Science Centre of the Russian Academy of Sciences and Bioforsk Soil and Environment from northeastern Norway. The duration of the project is 2012-2014 and most of the work has already been completed even if most of the results are not published yet. Totally ten different tasks have been implemented in the geological part of the project. The largest task has been the preparation of a geological outdoor map and guide book of the Khibiny Tundra locating in the central part of the Kola Peninsula. In Finland already 11 such maps have been published, and the experiences gained during their production have been used in this project, too. Geological heritage trails to the Khibiny Tundra have also been created and they will be drawn on the map. The second concrete result is the Barents Tour for Geotourist -guide, which will be published as a guide book, web pages and an exhibition. The route comprises ca 35 best geological demonstration sites along the circle route from northern Finland to northeastern Norway, from there to Kola Peninsula and then back to Finland. Information of the route will be available for all interested travelers. In addition to the geological outdoor map of the Khibiny Tundra and "Barents Tour for Geotourists"-guide, the primary outputs of the project are the geological nature trails on the field, geological

  13. 76 FR 24457 - Kenai Peninsula-Anchorage Borough Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... agency #0;statements of organization and functions are examples of documents #0;appearing in this section...; ] DEPARTMENT OF AGRICULTURE Forest Service Kenai Peninsula--Anchorage Borough Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Kenai Peninsula--Anchorage...

  14. 46 CFR 7.170 - Alaska Peninsula, AK to Aleutian Islands, AK.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Alaska Peninsula, AK to Aleutian Islands, AK. 7.170... BOUNDARY LINES Alaska § 7.170 Alaska Peninsula, AK to Aleutian Islands, AK. (a) A line drawn from the southernmost extremity of Cape Kumlium to the westernmost extremity of Nakchamik Island; thence to...

  15. 46 CFR 7.170 - Alaska Peninsula, AK to Aleutian Islands, AK.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Alaska Peninsula, AK to Aleutian Islands, AK. 7.170... BOUNDARY LINES Alaska § 7.170 Alaska Peninsula, AK to Aleutian Islands, AK. (a) A line drawn from the southernmost extremity of Cape Kumlium to the westernmost extremity of Nakchamik Island; thence to...

  16. 46 CFR 7.170 - Alaska Peninsula, AK to Aleutian Islands, AK.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Alaska Peninsula, AK to Aleutian Islands, AK. 7.170... BOUNDARY LINES Alaska § 7.170 Alaska Peninsula, AK to Aleutian Islands, AK. (a) A line drawn from the southernmost extremity of Cape Kumlium to the westernmost extremity of Nakchamik Island; thence to...

  17. 46 CFR 7.170 - Alaska Peninsula, AK to Aleutian Islands, AK.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Alaska Peninsula, AK to Aleutian Islands, AK. 7.170... BOUNDARY LINES Alaska § 7.170 Alaska Peninsula, AK to Aleutian Islands, AK. (a) A line drawn from the southernmost extremity of Cape Kumlium to the westernmost extremity of Nakchamik Island; thence to...

  18. 46 CFR 7.170 - Alaska Peninsula, AK to Aleutian Islands, AK.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Alaska Peninsula, AK to Aleutian Islands, AK. 7.170... BOUNDARY LINES Alaska § 7.170 Alaska Peninsula, AK to Aleutian Islands, AK. (a) A line drawn from the southernmost extremity of Cape Kumlium to the westernmost extremity of Nakchamik Island; thence to...

  19. Mission and modern citrus species diversity of Baja California Peninsula cases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spring-fed mission oases of the Baja California peninsula, Mexico, hold several species, varieties and unique hybrids of heritage citrus, which may represent valuable genetic resources. Citrus species first arrived to the peninsula with the Jesuit missionaries (1697-1768), and new varieties were...

  20. Digital data for the geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    USGS Publications Warehouse

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    1999-01-01

    These digital databases are the result of the compilation and reinterpretation of published and unpublished 1:250,000- and 1:63,360-scale mapping. The map area covers approximately 62,000 sq km (23,000 sq mi) in land area and encompasses much of 13 1:250,000-scale quadrangles on the Alaska Peninsula in southwestern Alaska. The compilation was done as part of the U.S. Geological Survey's Alaska Mineral Resource Assessment project (AMRAP), whose goal was create and assemble geologic, geochemical, geophysical, and other data in order to perform mineral resource assessments on a quadrangle, regional or statewide basis. The digital data here was created to assist in the completion of a regional mineral resource assessment of the Alaska Peninsula. Mapping on the Alaska Peninsula under AMRAP began in 1977 in the Chignik and Sutwik Island 1:250,000 quadrangles (Detterman and others, 1981). Continued mapping in the Ugashik, bristol bay, and northwestern Karluk quadrangles (Detterman and others, 1987) began in 1979, followed by the Mount Katmai, eastern Naknek, and northwestern Afognak quadrangles (Riehle and others, 1987; Riehle and others, 1993), the Port Moller, Stepovak bay, and Simeonof Island quadrangles (Wilson and others, 1995) beginning in 1983. Work in the Cold bay and False Pass quadrangles (Wilson and others, 1992 [Superceded by Wilson and others 1997, but not incorporated herein]) began in 1986. The reliability of the geologic mapping is variable, based, in part, on the field time spent in each area of the map, the available support, and the quality of the existing base maps. In addition, our developing understanding of the geology of the Alaska Peninsula required revision of earlier maps, such as the Chignik and Sutwik Island quadrangles map (Detterman and others, 1981) to reflect this new knowledge. We have revised the stratigraphic nomenclature (Detterman and others, 1996) and our assignment of unit names to some rocks has been changed. All geologic maps on

  1. Transboundary transport and deposition of Hg emission from springtime biomass burning in the Indo-China Peninsula

    NASA Astrophysics Data System (ADS)

    Wang, Xun; Zhang, Hui; Lin, Che-Jen; Fu, Xuewu; Zhang, Yiping; Feng, Xinbin

    2015-09-01

    Biomass burning from the Indo-China Peninsula region is an important source of atmospheric mercury (Hg). We isolated 18 unique transport events over 2 years using observations of Hg and CO at a high-altitude background site in southwestern China (Mount Ailao Observatory Station) to assess the transport and impact of Hg emissions from biomass burning. The quantity of Hg emission and the source regions were determined using ΔTGM/ΔCO slopes coupled with backward trajectory analysis and CO emission inventories. The slopes of ΔTGM/ΔCO appeared to be a useful chemical indicator for source identification. Industrial emission sources exhibited slopes in the range of 5.1-61.0 × 10-7 (parts per trillion by volume, pptv/pptv), in contrast to a slope of 2.0-6.0 × 10-7 for typical biomass burning. Transboundary transport of Hg from biomass burning led to episodically elevated atmospheric Hg concentrations during springtime. Hg emissions from biomass burning in the Indo-China Peninsula region from 2001 to 2008 were estimated to be 11.4 ± 2.1 Mg yr-1, equivalent to 40% of annual anthropogenic emissions in the region. In addition, Hg emissions from biomass burning contained a substantial fraction of particulate bound Hg (PBM). Assuming that PBM readily deposits locally (within 50 km), the local Hg deposition caused by the PBM was estimated to be 2.2 ± 0.4 Mg yr-1, up to 1 order of magnitude higher than the PBM deposition caused by anthropogenic emissions during springtime in the region. The strong springtime emissions potentially pose a threat to the ecosystems of the Indo-China Peninsula and southwest China.

  2. Modeling dynamics of tundra plant communities on the Yamal Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Yu, Q.; Epstein, H. E.; Walker, D. A.

    2010-12-01

    Multiple environmental drivers, including climate, soil conditions and herbivory, affect arctic tundra vegetation dynamics. These factors may have been evaluated individually in the past; however, their interactions contribute to more complicated tundra plant community dynamics and may represent a substantial source of uncertainty in predicting tundra ecosystem properties in the changing Arctic. This study investigates the effects of soils, grazing, and climate change on tundra plant communities at the plant functional type (PFT) level, based on previous integrated modeling research at the ecosystem level. The study area encompasses the Yamal Peninsula, northwestern Siberia, where soil and biomass data were collected along the Yamal Arctic Transect (YAT), to drive a nutrient-based tundra vegetation model (ArcVeg) and to validate the simulation results. We analyzed plant functional type biomass and net primary productivity (NPP), and found that with higher temperatures (+2°C mean growing season temperature), most plant functional types responded positively with increased biomass and NPP, while grazing suppressed such responses in both high and low soil organic nitrogen (SON) sites. The magnitudes of the responses to warming depended on SON and grazing intensity. Relatively, there were greater responses of biomass and NPP in low SON sites compared to high SON sites. Moss biomass (in contrast to other plant types) declined 34% with warming in the low SON site and 28% in the high SON site in subzone E (the most southern tundra subzone). Increases in Low Arctic shrub biomass with warming were 61% in the high SON site in subzone E and 96% in the low SON site. Decrease in moss biomass due to warming was mitigated about 2% by high grazing frequency (maximum of 25% of biomass removal every two years) in the high SON site in subzone E, with an opposite effect in the low SON site. High grazing frequency caused greater relative increases in total shrub biomass for both low

  3. The M0:mb Discriminant in the Arabian Peninsula

    NASA Astrophysics Data System (ADS)

    Maggi, A.; Priestley, K.

    2001-05-01

    We develop M0:mb relationships for the eastern Arabian peninsula using regional waveform data. We use recordings of earthquakes in the Zagros mountains of southern Iran by the permanent broad band station at RAYN and the 1995--1997 Passcal deployment in the surrounding region. We follow a similar procedure to Priestley and Patton (1997). We obtain seismic moments by applying the Bolt and Herraiz (1983) method, which uses the amplitude decay of the Lg phase, calibrated by the using Harvard CMT moments of the larger events. We establish the regional magnitude scales mb(P_n) and mb(L_g) by determining the attenuation rates of Pn and Lg waves, calibrating the mb(P_n) against the teleseismic mb, and applying the Nuttli (1973) method to determine mb from Lg waves. Preliminary results show that the calibration curve for M0( CMT) against M0(L_g) for the Arabian peninsula is approximately parallel to that for central Asia, but offset by an extra 0.25~mu. We also find that M0 vs mb values for Arabia plot consistently above those for central Asia by 0.25~mu.

  4. Cirques upon the Kamchatka Peninsula: palaeoglacial and palaeoclimatic inferences

    NASA Astrophysics Data System (ADS)

    Barr, Iestyn; Spagnolo, Matteo

    2013-04-01

    The morphometry of more than 3,500 cirques upon the Kamchatka Peninsula, Eastern Russia, has been analysed. Volumetric analysis suggests that these cirques have developed rather isometrically—growing equally in all dimensions. The cirques show a very strong N bias in their azimuth, likely resulting from aspect-related variations in insolation. The strength of this N bias is considered to indicate that former glaciation was often 'marginal', and mainly of cirque-type. This assertion is supported by the fact that S and SE-facing cirques are the highest in the dataset, suggesting that glacier-cover was rarely sufficient to allow S and SE-facing glaciers to develop at low altitudes. The strength of these azimuth-related variations in cirque altitude is thought to reflect comparatively cloud-free conditions during former periods of glaciation. These characteristics, of marginal glaciation and comparatively cloud-free conditions, are considered to reflect the region's former aridity, at the global Last Glacial Maximum, and during earlier periods of ice advance. There is published evidence to suggest extensive glaciation of the Kamchatka Peninsula at times during the Late Quaternary, yet the cirque data appears to suggest that such phases were comparatively short-lived, and that smaller cirque-type glaciers were generally more characteristic of the period.

  5. Neogene paleoenvironments and tectonics of the Hongchun Peninsula, southern Taiwan

    SciTech Connect

    Chang, S. . Taiwan Petroleum Exploration Div.); Vondra, C.F. . Geological Atmospheric Sciences)

    1993-03-01

    Recent investigations in the Hongchun Peninsula in southern Taiwan provide new evidence concerning the paleoenvironmental and tectonic interpretation of the structurally complex Neogene sediments exposed there. The deposits of the peninsula have been divided into four distinct fault-bounded sequences each displaying a different lithology and style of structural development. The Mutanchi formation consists of feldspathic quartz arenites derived from a granitic provenance to the north that were deposited in a forearc basin. The lower part of the Mutanchi is dominated by thick proximal turbidities and interbedded highly contorted shales of submarine fan origin. These grade upward into shallow marine feldpathic quartz arenites and shales. The Shiman Formation consists of tuffaceous lithic arenites (proximal turbidities) and diamicites (debris flow deposits) with gravel-sized metamorphic and volcanic clasts in the lower part and interbedded lithic arenites and shales in the upper part. Although of contrasting lithology to the Mutanchi, the lower part of the Shiman Formation was also deposited on a submarine fan in a forearc tectonic setting while the upper part was deposited on a shallow marine shelf. The Kentin Formation is composed entirely of thick light green mudstones with contorted slump structures. Locally it contains very large exotic blocks (olistoliths) of variable lithology and is interpreted to be a melange -- the Kentin Melange. The above four fault-bounded units represent a forearc basin-accretionary wedge complex that developed during the late Neogene as a result of convergent interaction between the South China and Philippine plates.

  6. Beryllium deposits of the western Seward Peninsula, Alaska

    USGS Publications Warehouse

    Sainsbury, C.L.

    1963-01-01

    Deposits of beryllium ore in the Lost River area of the western Seward Peninsula, Alaska, consist of replacement veins, pipes, and stringer lodes is limestone in a zone about 7 miles long and 2 to 3 miles wide which is faulted and intruded by dikes and stocks. The ores are remarkably alike and typically consist of the following minerals, in percent: fluorite, 45-65; diaspore, 5-10; tourmaline, 0-10; chrysoberyl, 3-10; white mica, 0-5; small amounts of hematite, sulfide minerals, manganese oxide, other beryllium minerals; and traces of minerals not yet identified. The ores generally are cut by late veinlets which are of the same mineralogy as the groundmass ore, or which consist of fluorite, white mica, and euclase. The ores are fine grained, and many of the individual mineral grains, except fluorite, are less than 1 mm in size. The beryllium content of bulk samples of ore ranges from 0.11 to 0.54 percent (0.31 to 1.50 percent BeO). High-grade nodules, composed principally of chrysoberyl, diaspore, fluorite, and mica, contain as much as 6 percent BeO. Geochemical reconnaissance has disclosed other areas of anomalous beryllium in stream sediments elsewhere on the Seward Peninsula, generally around biotite granites that have them associated with tin deposits; additional exploration probably will disclose other deposits.

  7. Distribution and characteristic of PAHs in snow of Fildes Peninsula.

    PubMed

    Na, Guangshui; Liu, Chunyang; Wang, Zhen; Ge, Linke; Ma, Xindong; Yao, Ziwei

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) investigation in different matrices has been reported largely, whereas reports on snow samples were limited. Snow, as the main matrix in the polar region, has an important study meaning. PAHs in snow samples were analyzed to investigate the distribution and contamination status of them in the Antarctic, as well as to provide some references for global migration of PAHs. Snow samples collected in Fildes Peninsula were enriched and separated by solid-phase membrane disks and eluted by methylene dichloride, then quantified by gas chromatography/mass spectrometry. All types of PAHs were detected except for Benzo(a)pyrene. Principal component analysis method was applied to characterize them. Three factors (Naphthalene, Fluorene and Phenanthrene) accounted for 60.57%, 21.61% and 9.80%, respectively. The results showed that the major PAHs sources maybe the atmospheric transportation, and the combustion of fuel in Fildes Peninsula. The comparison of concentration and types of PAHs between accumulated snow and fresh snow showed that the main compound concentrations in accumulated snow samples were higher than those in fresh ones. The risk assessment indicated that the amount of PAHs in the snow samples would not lead to ecological risk.

  8. Geographic distribution of the chytrid pathogen Batrachochytrium dendrobatidis among mountain amphibians along the Italian peninsula.

    PubMed

    Zampiglia, Mauro; Canestrelli, Daniele; Chiocchio, Andrea; Nascetti, Giuseppe

    2013-11-25

    The amphibian chytrid pathogen Batrachochytrium dendrobatidis (Bd) is considered a major cause of amphibian population declines, particularly in montane areas. Here, we investigated the presence and distribution of Bd among populations of 3 mid- to high-altitude species spanning the entire Italian peninsula (486 individuals from 39 sites overall): the stream frog Rana italica, the fire salamander Salamandra salamandra gigliolii, and the alpine newt Mesotriton alpestris apuanus. We found Bd in all of the analyzed species. Despite the widespread distribution of the pathogen, its overall prevalence (6, 9 and 19%, respectively) was lower than previously reported for the endangered Apennine yellow-bellied toad Bombina pachypus (62.5%). Moreover, several populations of the species studied here were not infected, even at sites where Bd has been detected in other host species. When coupled with the lack of evidence for Bd-related mortalities in these species in peninsular Italy, these results suggest that mechanisms of resistance and/or tolerance are protecting populations of these species from the pathogenic activity of Bd. Nevertheless, in light of the dynamic pattern of Bd-host interactions reported in other studies, of Bd-related mortalities in at least 1 study species (S. s. salamandra) in other areas, and the ongoing climate changes in montane environments, we suggest that the occurrence of Bd should be considered a potential threat to the long-term persistence of these species, and urge the implementation of monitoring and conservation plans. PMID:24270024

  9. Geographic distribution of the chytrid pathogen Batrachochytrium dendrobatidis among mountain amphibians along the Italian peninsula.

    PubMed

    Zampiglia, Mauro; Canestrelli, Daniele; Chiocchio, Andrea; Nascetti, Giuseppe

    2013-11-25

    The amphibian chytrid pathogen Batrachochytrium dendrobatidis (Bd) is considered a major cause of amphibian population declines, particularly in montane areas. Here, we investigated the presence and distribution of Bd among populations of 3 mid- to high-altitude species spanning the entire Italian peninsula (486 individuals from 39 sites overall): the stream frog Rana italica, the fire salamander Salamandra salamandra gigliolii, and the alpine newt Mesotriton alpestris apuanus. We found Bd in all of the analyzed species. Despite the widespread distribution of the pathogen, its overall prevalence (6, 9 and 19%, respectively) was lower than previously reported for the endangered Apennine yellow-bellied toad Bombina pachypus (62.5%). Moreover, several populations of the species studied here were not infected, even at sites where Bd has been detected in other host species. When coupled with the lack of evidence for Bd-related mortalities in these species in peninsular Italy, these results suggest that mechanisms of resistance and/or tolerance are protecting populations of these species from the pathogenic activity of Bd. Nevertheless, in light of the dynamic pattern of Bd-host interactions reported in other studies, of Bd-related mortalities in at least 1 study species (S. s. salamandra) in other areas, and the ongoing climate changes in montane environments, we suggest that the occurrence of Bd should be considered a potential threat to the long-term persistence of these species, and urge the implementation of monitoring and conservation plans.

  10. What shapes edaphic communities in mineral and ornithogenic soils of Cierva Point, Antarctic Peninsula?

    NASA Astrophysics Data System (ADS)

    Mataloni, G.; Garraza, G. González; Bölter, M.; Convey, P.; Fermani, P.

    2010-08-01

    Three mineral soil and four ornithogenic soil sites were sampled during summer 2006 at Cierva Point (Antarctic Peninsula) to study their bacterial, microalgal and faunal communities in relation to abiotic and biotic features. Soil moisture, pH, conductivity, organic matter and nutrient contents were consistently lower and more homogeneous in mineral soils. Ornithogenic soils supported larger and more variable bacterial abundances than mineral ones. Algal communities from mineral soils were more diverse than those from ornithogenic soils, although chlorophyll- a concentrations were significantly higher in the latter. This parameter and bacterial abundance were correlated with nutrient and organic matter contents. The meiofauna obtained from mineral soils was homogeneous, with one nematode species dominating all samples. The fauna of ornithogenic soils varied widely in composition and abundance. Tardigrades and rotifers dominated the meiofauna at eutrophic O2, where they supported a large population of the predatory nematode Coomansus gerlachei. At site O3, high bacterial abundance was consistent with high densities of the bacterivorous nematodes Plectus spp. This study provides evidence that Antarctic soils are complex and diverse systems, and suggests that biotic interactions (e.g. competition and predation) may have a stronger and more direct influence on community variability in space and time than previously thought.

  11. Assessing trace element contamination in Fildes Peninsula (King George Island) and Ardley Island, Antarctic.

    PubMed

    Amaro, Eduardo; Padeiro, Ana; Mão de Ferro, André; Mota, Ana Maria; Leppe, Marcelo; Verkulich, Sergey; Hughes, Kevin A; Peter, Hans-Ulrich; Canário, João

    2015-08-15

    King George Island, situated in the South Shetland Islands archipelago, is one of the most visited sites in Antarctica. This has contributed to a high density of scientific stations and shelters in the region, especially in Fildes Peninsula. In order to evaluate the natural and anthropogenic sources of trace elements (As, Cd, Cu, Zn, Pb and Hg) soil and moss samples were collected from different sites in January 2013. In general, the results revealed homogeneous concentrations (μgg(-)(1)) for each element in the majority of collected samples (As: 3.8±1.4; Cd: 0.4±0.9; Cu: 34±4; Zn: 115±13; Pb: 20±5; Hg; 0.011±0.009). However, some samples in specific areas of Fildes Bay showed the existence of local anthropogenic activities that have contributed to the enrichment of contaminants in soils and moss samples that correlated to one another (e.g. Pb: 1101μgg(-)(1)). Human presence is linked to examples of contamination and environmental perturbation, making essential the implementation of this type of study in order to understand and protect unique places in Antarctica. PMID:25982820

  12. Assessing trace element contamination in Fildes Peninsula (King George Island) and Ardley Island, Antarctic.

    PubMed

    Amaro, Eduardo; Padeiro, Ana; Mão de Ferro, André; Mota, Ana Maria; Leppe, Marcelo; Verkulich, Sergey; Hughes, Kevin A; Peter, Hans-Ulrich; Canário, João

    2015-08-15

    King George Island, situated in the South Shetland Islands archipelago, is one of the most visited sites in Antarctica. This has contributed to a high density of scientific stations and shelters in the region, especially in Fildes Peninsula. In order to evaluate the natural and anthropogenic sources of trace elements (As, Cd, Cu, Zn, Pb and Hg) soil and moss samples were collected from different sites in January 2013. In general, the results revealed homogeneous concentrations (μgg(-)(1)) for each element in the majority of collected samples (As: 3.8±1.4; Cd: 0.4±0.9; Cu: 34±4; Zn: 115±13; Pb: 20±5; Hg; 0.011±0.009). However, some samples in specific areas of Fildes Bay showed the existence of local anthropogenic activities that have contributed to the enrichment of contaminants in soils and moss samples that correlated to one another (e.g. Pb: 1101μgg(-)(1)). Human presence is linked to examples of contamination and environmental perturbation, making essential the implementation of this type of study in order to understand and protect unique places in Antarctica.

  13. Trends in photochemical smog in the Cape Peninsula and the implications for health.

    PubMed

    Bailie, R S; Ehrlich, R I; Truluck, T F

    1994-11-01

    There has been growing public concern over reports of increasing air pollution in the Cape Peninsula. Attention has been focused on the 'brown haze' and on photochemical smog. Because of deficiencies in the monitoring equipment, information on trends in photochemical smog levels over the past decade is limited. Trends in oxides of nitrogen, one of the main precursors of photochemical smog, and therefore an indicator of the potential for its formation, were examined for the period 1984-1993. Meaningful data for determining trends were available from only a single site. Increases in mean monthly levels, peak hourly levels and the number of times guidelines were exceeded were demonstrated. Given the dynamics of formation of photochemical smog and the particular role of motor vehicles, it is argued that the trends measured at this site are probably an underestimate of the trends in other parts of the Cape Town metropolitan area. Some of the precursors of photochemical smog, notably nitrogen dioxide, and some of its components, notably ozone, have been shown to be detrimental to respiratory health at levels close to, or below, current recommended guidelines. A continuing increase in these pollutants will therefore result in more respiratory illness, particularly among susceptible groups. This calls for an upgrading of monitoring of air pollution in Cape Town and for appropriate steps to prevent its further increase.

  14. Benthic infauna variability in relation to environmental factors and organic pollutants in tropical coastal lagoons from the northern Yucatan Peninsula.

    PubMed

    Kuk-Dzul, J Gabriel; Gold-Bouchot, G; Ardisson, P-L

    2012-12-01

    We examine the abundance and species composition variability of benthic infauna from tropical coastal lagoons in relation to environmental factors and organic pollutants. Sediment samples were collected at 40 sites in four lagoons in the northern Yucatan Peninsula. A total of 7985 individuals belonging to 173 species were sampled. While the eastern lagoons were dominated by polychaetes, the western ones were dominated by crustaceans. Overall, polychaetes had the highest abundance (48%), followed by crustaceans (42%). According to canonical correspondence analysis, species attributes were correlated with water salinity, pH and temperature, but also with sediment pentachlorobenzene, trichlorobenzene, and low molecular weight polycyclic aromatic hydrocarbons. Some pollutants exceeded sediment quality guidelines, representing a potential environmental risk to benthic infauna. Together, environmental factors and pollutants explained 52% of the variance in abundance and species composition among sites.

  15. Simulating the effects of soil organic nitrogen and grazing on arctic tundra vegetation dynamics on the Yamal Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Yu, Qin; Epstein, Howard; Walker, Donald

    2009-10-01

    Sustainability of tundra vegetation under changing climate on the Yamal Peninsula, northwestern Siberia, home to the world's largest area of reindeer husbandry, is of crucial importance to the local native community. An integrated investigation is needed for better understanding of the effects of soils, climate change and grazing on tundra vegetation in the Yamal region. In this study we applied a nutrient-based plant community model—ArcVeg—to evaluate how two factors (soil organic nitrogen (SON) levels and grazing) interact to affect tundra responses to climate warming across a latitudinal climatic gradient on the Yamal Peninsula. Model simulations were driven by field-collected soil data and expected grazing patterns along the Yamal Arctic Transect (YAT), within bioclimate subzones C (high arctic), D (northern low arctic) and E (southern low arctic). Plant biomass and NPP (net primary productivity) were significantly increased with warmer bioclimate subzones, greater soil nutrient levels and temporal climate warming, while they declined with higher grazing frequency. Temporal climate warming of 2 °C caused an increase of 665 g m-2 in total biomass at the high SON site in subzone E, but only 298 g m-2 at the low SON site. When grazing frequency was also increased, total biomass increased by only 369 g m-2 at the high SON site in contrast to 184 g m-2 at the low SON site in subzone E. Our results suggest that high SON can support greater plant biomass and plant responses to climate warming, while low SON and grazing may limit plant response to climate change. In addition to the first order factors (SON, bioclimate subzones, grazing and temporal climate warming), interactions among these significantly affect plant biomass and productivity in the arctic tundra and should not be ignored in regional scale studies.

  16. Multichannel Seismic Investigations of Sediment Drifts off West Antarctica and the Antarctic Peninsula: Preliminary Results from Research Cruise JR298

    NASA Astrophysics Data System (ADS)

    Larter, R. D.; Graham, A. G. C.; Hernandez-Molina, J.; Channell, J. E. T.; Hillenbrand, C. D.; Hogan, K. A.; Uenzelmann-Neben, G.; Gohl, K.; Rebesco, M.; Hodell, D. A.

    2015-12-01

    The West Antarctic Ice Sheet (WAIS) and Antarctic Peninsula Ice Sheet (APIS) have exhibited significant changes over recent decades but there is still great uncertainty about how rapidly and how far they will retreat in a warmer climate. For example, it remains unclear whether or not the marine-based WAIS "collapsed" during the last interglacial period, resulting in a global sea-level rise contribution of more than 3 m. Previous studies, including Ocean Drilling Program (ODP) Leg 178, have shown that sediment drifts on the continental rise west of the Antarctic Peninsula contain a rich high-resolution archive of Antarctic margin paleoceanography and APIS history that extends back to at least the Late Miocene. The potential of existing ODP cores from the drifts is, however, compromised by the fact that composite sections are incomplete and lack of precise chronological control. A new drilling proposal (732-Full2) has been scientifically approved and is with the JOIDES Resolution Facilities Board of the International Ocean Discovery Program for scheduling. The main aims of the proposal are to obtain continuous, high-resolution records from sites on sediment drifts off both the Antarctic Peninsula and West Antarctica (southern Bellingshausen Sea) and to achieve good chronological control on them using a range of techniques. We present preliminary results from a recent site survey investigation cruise on RRS James Clark Ross (JR298) that obtained high-resolution multichannel seismic reflection data over the proposed sites and adjacent working areas. The new data provide a basis for interpretation of (i) sedimentary processes that operated during the development of the drifts, and (ii) links between depositional systems on the continental rise, paleo-ice-sheet dynamics and paleoceanographic processes. Through further analyses of seismic and other geophysical data, in combination with marine sediment cores retrieved from the proposed sites, we aim to provide insight into

  17. Segmentation of Hypocenters and 3-D Velocity Structure around the Kii Peninsula Revealed by Onshore and Offshore Seismic Observations

    NASA Astrophysics Data System (ADS)

    Akuhara, T.; Mochizuki, K.; Nakahigashi, K.; Yamada, T.; Shinohara, M.; Sakai, S.; Kanazawa, T.; Uehira, K.; Shimizu, H.

    2013-12-01

    The Philippine Sea Plate subducts beneath the Eurasian Plate at a rate of ~4 cm/year along the Nankai Trough, southwest of Japan. Around the Kii Peninsula, the rupture boundary of the historical Tonankai and Nankai large earthquakes is located, and previous researches have revealed along-strike segmentation of hypocenters [Mochizuki et al., 2010], P-wave anisotropy [Ishise et al., 2009], low frequency earthquake (LFE) distribution [e.g., Obara, 2010] and subduction depth of the Philippine Sea (PHS) Plate, or there may exist a split in the PHS Plate [Ide et al., 2010]. To investigate such segmentation, in our previous work we determined 3-D velocity structure and hypocenters using P- and S-wave arrival times of earthquakes recorded by both ocean bottom seismometers (OBSs) that were deployed from 2003 to 2007 and on-land stations [Akuhara et al., 2013]. As a result, it was discovered that Vp/Vs ratio is also segmented within the oceanic crust and at the bottom of the overriding plate, which coincides with the LFE distribution: segment A is located along the Kii Channel, segment B around the western Kii Peninsula, and segment C around the eastern Kii Peninsula. In segment B, Vp/Vs ratio is low within the oceanic crust and LFE cluster characterized by an anomalously small amount of cumulative slip, compared to the other LFE clusters around the Kii Peninsula, is located [Obara, 2010]. The difference of Vp/Vs ratio and LFE activity among segments were interpreted as difference of pore fluid pressure. In fact, similar segmentation can be seen in hypocenters: Segment A with concentrated seismicity in the oceanic mantle, segment B with that in the oceanic crust, and segment C with little seismicity. To derive characteristic patterns of the hypocenters, we conducted a cluster analysis of earthquakes based on waveform similarity represented by cross-correlation coefficients (CCs) [e.g., Cattaneo, 1999], in which we took varying structural site effects among the OBS stations

  18. Expanding Ice Sheets on the Antarctic Peninsula during the Plio/Pleistocene Recorded in Continental Rise Sediment Drifts

    NASA Astrophysics Data System (ADS)

    Cowan, E. A.; Hillenbrand, C.

    2007-12-01

    Sediment drifts on the continental rise west of the Antarctic Peninsula are located within 125 km from the continental shelf edge, the main contributor of terrigenous sediment during both glacial and interglacial periods. The composition of drift deposits continuously recorded changes in ice sheet volume and thermal regime as well as sea surface temperatures (SSTs) and sea ice extent. The coarse-grained terrigenous sediment (pebbles and coarse sand), a proxy for iceberg-rafted debris (IRD), was analyzed in sediments spanning the last 3.1 m.y. at Ocean Drilling Program (ODP) Sites 1101 and 1096. IRD is deposited in both glacial intervals, dominated by fine-grained laminated mud and interglacial units consisting of bioturbated muds enriched in biogenic components. Contents of biogenic opal, which reflect diatom abundance, are relatively high from 3.1-2.2 Ma. Calcareous nannofossils are present within interglacial sediments from 2.2-0.76 Ma. Both findings suggest warm SSTs and limited sea ice over the drifts during interglacial periods before the Late Pleistocene. Quartz grains picked from the IRD fraction and imaged with a scanning electron microscope (SEM) show an abrupt change in surface microtextures at 1.35 Ma. During the Late Pliocene to Early Pleistocene, many quartz grains are completely weathered and only a few show signs of crushing and abrasion, indicating that glaciers were too small to inundate the Antarctic Peninsula topography. Debris shed from mountain peaks was transported supraglacially or englacially allowing weathered grains to pass unmodified through the glaciers. Glaciers expanded in size during glacial periods from 1.35-0.76 Ma. The IRD accumulation during those periods was very high and diverse dropstone lithologies document supply from sources throughout the Antarctica Peninsula. Conditions that spawned the large polar ice sheet identified at the Last Glacial Maximum have been present on the Antarctic Peninsula during glacial periods since

  19. Earthquake Swarm in Armutlu Peninsula, Eastern Marmara Region, Turkey

    NASA Astrophysics Data System (ADS)

    Yavuz, Evrim; Çaka, Deniz; Tunç, Berna; Serkan Irmak, T.; Woith, Heiko; Cesca, Simone; Lühr, Birger-Gottfried; Barış, Şerif

    2015-04-01

    The most active fault system of Turkey is North Anatolian Fault Zone and caused two large earthquakes in 1999. These two earthquakes affected the eastern Marmara region destructively. Unbroken part of the North Anatolian Fault Zone crosses north of Armutlu Peninsula on east-west direction. This branch has been also located quite close to Istanbul known as a megacity with its high population, economic and social aspects. A new cluster of microseismic activity occurred in the direct vicinity southeastern of the Yalova Termal area. Activity started on August 2, 2014 with a series of micro events, and then on August 3, 2014 a local magnitude is 4.1 event occurred, more than 1000 in the followed until August 31, 2014. Thus we call this tentatively a swarm-like activity. Therefore, investigation of the micro-earthquake activity of the Armutlu Peninsula has become important to understand the relationship between the occurrence of micro-earthquakes and the tectonic structure of the region. For these reasons, Armutlu Network (ARNET), installed end of 2005 and equipped with currently 27 active seismic stations operating by Kocaeli University Earth and Space Sciences Research Center (ESSRC) and Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum (GFZ), is a very dense network tool able to record even micro-earthquakes in this region. In the 30 days period of August 02 to 31, 2014 Kandilli Observatory and Earthquake Research Institute (KOERI) announced 120 local earthquakes ranging magnitudes between 0.7 and 4.1, but ARNET provided more than 1000 earthquakes for analyzes at the same time period. In this study, earthquakes of the swarm area and vicinity regions determined by ARNET were investigated. The focal mechanism of the August 03, 2014 22:22:42 (GMT) earthquake with local magnitude (Ml) 4.0 is obtained by the moment tensor solution. According to the solution, it discriminates a normal faulting with dextral component. The obtained focal mechanism solution is

  20. Temporal variations in (134)Cs and (137)Cs concentrations in seawater along the Shimokita Peninsula and the northern Sanriku coast in northeastern Japan, one year after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Kofuji, Hisaki; Inoue, Mutsuo

    2013-10-01

    Ninety-six seawater samples were collected between May 2011 and March 2012 at 6 sites along the Shimokita Peninsula and the northern Sanriku coast, 250-450 km north of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP). Cesium-134 and (137)Cs concentrations were determined by low-background γ-spectrometry. During May-June 2011, (134)Cs and (137)Cs concentrations in surface waters decreased from 1.0-2.8 to 0.7-1.5 mBq/L and from 2.1-3.9 to 1.9-3.0 mBq/L, respectively. These decreases were due to diffusion and advection in the ocean after atmospheric input of the FDNPP-derived radionuclides. However, in July-August 2011, the concentrations of both radionuclides in the water samples collected on the Pacific side of the Shimokita Peninsula and the northern Sanriku coast exhibited 30-50-fold increases (∼40 mBq/L for (134)Cs and ∼50 mBq/L for (137)Cs) over concentrations observed at these sampling sites in June 2011 in contrast to the gradual decreases in the concentrations on the Tsugaru Strait side of the Shimokita Peninsula. These results suggest that radiocesium-contaminated waters offshore in the Pacific Ocean were transported to coastal regions along the Pacific side of the Shimokita Peninsula and the northern Sanriku coast by ocean currents.

  1. The return to the Iberian Peninsula: first Quaternary record of Muscardinus and a palaeogeographical overview of the genus in Europe

    NASA Astrophysics Data System (ADS)

    Garcia-Ibaibarriaga, Naroa; Arrizabalaga, Álvaro; Iriarte-Chiapusso, María-José; Rofes, Juan; Murelaga, Xabier

    2015-07-01

    Although the earliest record of the genus Muscardinus dates from the Middle Miocene in Spain, no mention has been reported since the Lower Pliocene in the Iberian Peninsula. In this paper, Quaternary fossil remains of a hazel dormouse (Muscardinus avellanarius) are described, for the first time, in the Iberian Peninsula. These remains constitute the south-westernmost record of the genus in the Eurasian continent during the Late Pleistocene. The fossils, one first upper molar (M1) and two second upper molars (M2), come from Lezetxiki II Cave, an early Late Pleistocene site in northern Spain. The presence of the hazel dormouse agrees with the abundance of rodent species indicative of woodland, suggesting mild climatic conditions and a landscape formed by deciduous forest. This assemblage has been arguably assigned to warm and humid conditions related to an interstadial period in MIS 5. We also present an overview of the palaeogeography of the genus in Europe. The identification of this dormouse reinforces the idea of biological corridors between western Iberia and the rest of Europe during the Pleistocene.

  2. Late Holocene tephrochronology of the northern Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Björck, Svante; Sandgren, Per; Zale, Rolf

    1991-11-01

    Andesitic and basaltic andesitic tephra layers are abundant in Holocene deposits from the Antarctic Peninsula. Visually discernible tephra horizons occur in three lakes on Livingston Island. Tephra in two other lakes and in a moss bank on Elephant Island, with very low ash concentrations, were detected magnetically. Deception Island is the most likely volcanic source for the tephra. With direct 14C dating, age/depth curves, and cross-correlations at least 14 tephra horizons dating to between ca. 4700 and 250 yr B.P. were identified and now form the basis for a preliminary regional tephrochronology that will be a valuable dating tool for investigating the Holocene climatic history of Antarctica.

  3. Preliminary Geomorphic Map of the Kitsap Peninsula, Washington

    USGS Publications Warehouse

    Haugerud, Ralph A.

    2009-01-01

    The Kitsap Peninsula, in the center of the Puget Lowland of Washington State, has been glaciated repeatedly during the last 2 million years. This geologic history is significant to our understanding of crustal deformation, ground- and surface-water resources, the distribution of fishes, and other topics. Recent high-resolution lidar (LIght Detection And Ranging; also known as airborne laser swath mapping, or ALSM) topographic surveys of much of the Puget Lowland provide a more accurate depiction of the morphology of this forested landscape than has previously been available. More accurate morphology promises more accurate mapping of unconsolidated deposits and a more detailed earth history, particularly in this low-relief forested region where outcrops are not abundant and many deposits are similar in composition. In order to clarify the chain of observation and inference that proceeds from morphology to geologic map, this map describes the distribution of morphologic units - the 2-dimensional surfaces that bound near-surface deposits.

  4. Ocean forcing of glacier retreat in the western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Cook, A. J.; Holland, P. R.; Meredith, M. P.; Murray, T.; Luckman, A.; Vaughan, D. G.

    2016-07-01

    In recent decades, hundreds of glaciers draining the Antarctic Peninsula (63° to 70°S) have undergone systematic and progressive change. These changes are widely attributed to rapid increases in regional surface air temperature, but it is now clear that this cannot be the sole driver. Here, we identify a strong correspondence between mid-depth ocean temperatures and glacier-front changes along the ~1000-kilometer western coastline. In the south, glaciers that terminate in warm Circumpolar Deep Water have undergone considerable retreat, whereas those in the far northwest, which terminate in cooler waters, have not. Furthermore, a mid-ocean warming since the 1990s in the south is coincident with widespread acceleration of glacier retreat. We conclude that changes in ocean-induced melting are the primary cause of retreat for glaciers in this region.

  5. Leishmania spp. Epidemiology of Canine Leishmaniasis in the Yucatan Peninsula

    PubMed Central

    López-Céspedes, A.; Longoni, S. S.; Sauri-Arceo, C. H.; Sánchez-Moreno, M.; Rodríguez-Vivas, R. I.; Escobedo-Ortegón, F. J.; Barrera-Pérez, M. A.; Bolio-González, M. E.; Marín, C.

    2012-01-01

    Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high. PMID:22927792

  6. Ocean forcing of glacier retreat in the western Antarctic Peninsula.

    PubMed

    Cook, A J; Holland, P R; Meredith, M P; Murray, T; Luckman, A; Vaughan, D G

    2016-07-15

    In recent decades, hundreds of glaciers draining the Antarctic Peninsula (63° to 70°S) have undergone systematic and progressive change. These changes are widely attributed to rapid increases in regional surface air temperature, but it is now clear that this cannot be the sole driver. Here, we identify a strong correspondence between mid-depth ocean temperatures and glacier-front changes along the ~1000-kilometer western coastline. In the south, glaciers that terminate in warm Circumpolar Deep Water have undergone considerable retreat, whereas those in the far northwest, which terminate in cooler waters, have not. Furthermore, a mid-ocean warming since the 1990s in the south is coincident with widespread acceleration of glacier retreat. We conclude that changes in ocean-induced melting are the primary cause of retreat for glaciers in this region. PMID:27418507

  7. SEISMIC DATA FOR NUCLEAR EXPLOSION MONITORING IN THE ARABIAN PENINSULA

    SciTech Connect

    Rodgers, A; Al-Amri, A

    2004-07-08

    We report results from the third and final year of our project (ROA0101-35) to collect seismic event and waveform data recorded in and around the Arabian Peninsula. This effort involves several elements. We are working with King Abdulaziz City for Science and Technology to collect data from the Saudi National Seismic Network, that consists of 38 digital three-component stations (27 broadband and 11 short-period). We have an ongoing collaboration with the Kuwait Institute for Scientific Research, which runs the eight station Kuwait National Seismic Network. We installed two temporary broadband stations in the United Arab Emirates (funded by NNSA NA-24 Office of Non-Proliferation & International Security). In this paper we present a summary of data collected under these efforts including integration of the raw data into LLNL's Seismic Research Database and preliminary analysis of souce parameters and earth structure.

  8. Evidence for temperate conditions along the Antarctic peninsula during the Early Tertiary

    SciTech Connect

    Zinsmeister, W.J.

    1985-01-01

    Several investigators based on deep sea glacial marine sediments from the southern oceans and volcanic sequences in West Antarctica have suggested extreme glacial conditions existed around Antarctica during the early Tertiary. Their data suggest ice sheets with ice shelves greater than those today were present on Antarctica by the late Eocene. If these data are correct, conditions during the Eocene along the Peninsula were similar to those that exist today. Late Eocene faunas and floras from Seymour Island indicate that conditions along the Peninsula were temperature. No paleontologic or geologic evidence have been obtained from Seymour Island (64/degree/18'S) to support the existence of glacial conditions along the northern part of the Peninsula during the early Tertiary. The presence of large quantities of fossil wood and plant debris in the upper Eocene sediments on Seymour Island indicates the presence of dense forests on the Peninsula during the Eocene. The discovery of marsupial and land birds remains on Seymour Island also indicate the presence of abundant terrestrial life on the Peninsula. The occurrence of an abundant marine life on Seymour Island supports the existence of temperate conditions along the Peninsula. Similarities of the Eocene faunas and floras with present day biotas from Tasmania, New Zealand and southern South America indicate that conditions along the Antarctic Peninsula during the late Eocene were comparable to present day mid latitudes of the southern hemisphere.

  9. Phosphorus leaching from agricultural soils of the delmarva peninsula, USA.

    PubMed

    Kleinman, Peter J A; Church, Clinton; Saporito, Lou S; McGrath, Josh M; Reiter, Mark S; Allen, Arthur L; Tingle, Shawn; Binford, Greg D; Han, Kun; Joern, Brad C

    2015-03-01

    Leaching of phosphorus (P) mobilizes edaphic and applied sources of P and is a primary pathway of concern in agricultural soils of the Delmarva Peninsula, which defines the eastern boundary of the eutrophic Chesapeake Bay. We evaluated P leaching before and after poultry litter application from intact soil columns (30 cm diameter × 50 cm depth) obtained from low- and high-P members of four dominant Delmarva Peninsula soils. Surface soil textures ranged from fine sand to silt loam, and Mehlich-3 soil P ranged from 64 to 628 mg kg. Irrigation of soil columns before litter application pointed to surface soil P controls on dissolved P in leachate (with soil P sorption saturation providing a stronger relationship than Mehlich-3 P); however, strong relationships between P in the subsoil (45-50 cm) and leachate P concentrations were also observed ( = 0.61-0.73). After poultry litter application (4.5 Mg ha), leachate P concentrations and loads increased significantly for the finest-textured soils, consistent with observations that well-structured soils have the greatest propensity to transmit applied P. Phosphorus derived from poultry litter appeared to contribute 41 and 76% of total P loss in leachate from the two soils with the finest textures. Results point to soil P, including P sorption saturation, as a sound metric of P loss potential in leachate when manure is not an acute source of P but highlight the need to factor in macropore transport potential to predict leaching losses from applied P sources. PMID:26023971

  10. Long-term persistence of subduction earthquake segment boundaries - evidence from Mejillones Peninsula, N-Chile

    NASA Astrophysics Data System (ADS)

    Victor, P.; Sobiesiak, M.; Nielsen, S.; Glodny, J.; Oncken, O.

    2010-12-01

    The Mejillones Peninsula in N-Chile is a strong anomaly in coastline morphology along the Chilean convergent margin. The location of the Peninsula coincides with the northern limit of the 1995 Mw=8.0 Antofagasta earthquake and the southern limit of the 2007 Mw=7.8 Tocopilla earthquake and, probably, also with the southern limit of the 1877 Mw=8.5 Iquique earthquake. Although it is tempting to recognise the Mejillones Peninsula as the surface expression of a major segment boundary for large subduction earthquakes, so far evidence for its stability over multiple seismic cycles is lacking. We introduce a detailed analysis of the aftershock sequences in combination with new age data of the surface uplift evolution since the late Pliocene to test the hypothesis whether earthquake rupture propagation is limited at the latitude of Mejillones Peninsula since a longer time period. If the Peninsula really is linked to a persistent segment boundary, then the surface deformation of the Peninsula in fact holds the record about a deep-seated mechanism revealing the interaction between the subduction process and near-surface deformation. In our study we present new chronostratigraphic and structural data that allow reconstructing the evolution of the Peninsula at the surface and correlation of the latter with seismic cycle deformation on the interface. We investigated sets of paleo-strandlines preserved in beach ridges and uplifted cliffs to reconstruct the uplift history of the Peninsula. Our results show that the central graben area on the Peninsula started uplifting above sea level as an anticlinal hinge zone prior to 400 ky ago, most probably 790 ky ago. The resulting E-W trending hinge exactly overlies the limit between the rupture planes of the Antofagasta and Tocopilla earthquakes. By correlating the uplift data with the slip distribution of the Antofagasta and Tocopilla earthquakes, we demonstrate that deformation and uplift is focussed during the postseismic and

  11. Paleoseismic Studies of the Peninsula San Andreas Fault near Crystal Springs Reservoir, Woodside, California

    NASA Astrophysics Data System (ADS)

    Prentice, C. S.; Zachariasen, J. A.; Kozaci, O.; Clahan, K.; Sickler, R. R.; Rosa, C. M.; Hassett, W.; Feigelson, L.; Haproff, P. J.; DeLong, S.; Perkins, A.; Brooks, B. A.; Delano, J.; Baldwin, J. N.

    2013-12-01

    The Peninsula section of the San Andreas Fault (SAFP) is within 10 km of downtown San Francisco, making it among the most significant contributors to seismic hazard in the San Francisco Bay area. However, the history of earthquakes along this fault is poorly known. The most recent ground-rupturing earthquake occurred in 1906, but the ages of earlier earthquakes associated with surface rupture on this fault segment remain uncertain. Most researchers assume that the historically documented earthquake in 1838 occurred on the SAFP, but no definitive evidence of surface rupture at that time has been found. South of Crystal Springs Reservoir, the San Andreas Fault zone is expressed as a prominent fault scarp that is cut back in several locations by recent fluvial processes. At our Crystal Springs South (CSS) trench site, the fault is expressed as a low scarp with no other surface expression to suggest additional young fault traces. Excavations at this site revealed two distinct sets of faults, a younger set of faults that extend nearly to the modern ground surface that we assume represent the 1906 surface rupture, and an older set of faults that terminate lower in the stratigraphic section and are overlain by a scarp-derived colluvial deposit. Radiocarbon dating constrains the age of this older earthquake to 830-930 Cal. years BP. We determined that a buried channel deposit that dates to 790-960 Cal. years BP is displaced approximately 6-7m across both sets of faults. The closest 1906 offset measurement was made about 11 km northwest of this site, and is about 2.9m. Therefore our measurement of 6-7m of offset on the buried channel deposit at the CSS site could represent slip from 1906 and only one previous event comparable in size to the 1906 earthquake. The surprisingly old age of the earlier earthquake raises concerns that one or both of the event horizons exposed at the CSS site could represent multiple earthquakes. We therefore excavated an exploratory trench about 0

  12. Permafrost degradation after the 2002 wildfire in Kougarok, Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Iwahana, G.; Harada, K.; Uchida, M.; Kondo, M.; Saito, K.; Narita, K.; Kushida, K.; Hinzman, L. D.; Fukuda, M.; Tsuyuzaki, S.

    2014-12-01

    Geomorphological and thermo-hydrological changes after wildfire were investigated here to clarify the rates of permafrost degradation and impacts on the surrounding environment. Study sites are located in Kougarok on the central Seward Peninsula of northwestern Alaska. This area is classified as zones of either continuous and discontinuous permafrost. In 2002, wildfire burned a large area of this region. We selected an intact area and a burned area as research sites located close to one another and divided by a road. The surface organic layer was either combusted or reduced in thickness during the fire. It is assumed that the vegetation cover and subsurface conditions were similar between both sites before the fire. General vegetation at unburned sites was shrub-tussock tundra with more than 30 % evergreen shrubs, about 30 % deciduous shrubs and about 20 % sedges. Our studies of aerial photography and high-resolution satellite images showed that surface subsidence due to thermokarst developed differentially within some of the burned and vehicle-disturbed areas, exposing the polygonal reliefs on the surface. Within burned areas absent the thermokarst polygonal reliefs, soil moisture was higher at burned areas than unburned, and the active layer thickness was about 1.5-2.0 times deeper at the burned area during the initial stage of the study (2005-2007). In the following years, however, the difference in active layer thickness decreased, and thickness for the burned area seemed to be recovering to pre-fire status. Geophysical surveys demonstrated that there had been no detectable difference in the depth of the permafrost base between the burned and unburned areas. On the other hand, at the burned site with thermokarst polygonal reliefs, we confirmed using differential GPS that the polygonal reliefs actually coincides with depression lines along the subsurface ice wedge network. Near-surface unfrozen and frozen soil cores down to 1.6 m depth were sampled at seven and

  13. SHRIMP U-Pb dating and geochemistry of the Cretaceous plutonic rocks in the Korean Peninsula: A new tectonic model of the Cretaceous Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Kim, Sung Won; Kwon, Sanghoon; Park, Seung-Ik; Lee, Changyeol; Cho, Deung-Lyong; Lee, Hong-Jin; Ko, Kyoungtae; Kim, Sook Ju

    2016-10-01

    The Cretaceous tectonomagmatism of the Korean Peninsula was examined based on geochemical and geochronological data of the Cretaceous plutonic rocks, along with distribution of volcano-sedimentary nonmarine N- to NE-trending fault bounded sedimentary basins. We conducted sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages and whole-rock geochemical compositions of 21 Cretaceous plutonic rocks, together with previously published data, from the central to southern Korean Peninsula. Four age groups of plutonic rocks were identified: Group I (ca. 119-106 Ma) in the northern to central area, Group II (ca. 99-87 Ma) in the central southern area, Group III (ca. 85-82 Ma) in the central to southern area, and Group IV (ca. 76-67 Ma) in the southernmost area. These results indicate a sporadic trenchward-younging trend of the Cretaceous magmatism in the Korean Peninsula. The Group I, II, and III rocks are dominated by high-K calc-alkaline I-type rocks with rift-related A-type granitoids. In contrast, the Group IV rocks are high-K calc-alkaline I-type plutonic rocks with no A-type rocks. The geochemical signatures of the entire groups indicated LREEs (light rare earth elements) enrichments and negative Nb, Ta, and Ti anomalies, indicating normal arc magmatism. A new tectonic model of the Cretaceous Korean Peninsula was proposed based on temporal and spatial distribution of the Cretaceous plutons represented by four age groups; 1) magmatic quiescence throughout the Korean Peninsula from ca. 160 to 120 Ma, 2) intrusions of the I- and A-type granitoids in the northern and central Korean Peninsula (Group I plutonic rocks from ca. 120 to 100 Ma) resulted from the partial melting of the lower continental crust due to the rollback of the Izanagi plate expressed as the conversion from flat-lying subduction to normal subduction. The Gyeongsang nonmarine sedimentary rift basin in the Korean Peninsula and adakite magmatism preserved in the present-day Japanese Islands

  14. [Imposex in Voluta musica (Caenogastropoda: Volutidae) from Northeastern Peninsula de Araya, Venezuela].

    PubMed

    Peralta, Ana Carolina; Miloslavich, Patricia; Bigatti, Gregorio

    2014-06-01

    Voluta musica is a dioecious marine gastropod endemic of the South Caribbean. Tributyltin (TBT) and copper (Cu) are potential inducers of imposex, an endocrine disorder by which females develop a penis and/or vas deferens. The goal of this work was to determine the imposex incidence in V. musica populations from Northeastern Peninsula de Araya. For this, we selected three sites (Isla Caribe, Isla Lobos and Bajo Cuspe) and made monthly samplings of 15 snails in each site, during one year, and determined: (1) sizes; (2) sex and imposex incidence and (3) the Relative Penis Length Index (RPLI). We also performed histological analysis of the gonads, and measured TBT and Cu concentrations in sediments from the studied localities. Our results showed that the total number of sampled females affected by imposex was 24.5% at Isla Caribe, 12% at Isla Lobos, and none at Bajo Cuspe. In sediments, Cu was detected mostly in Isla Lobos. The female gonads with imposex did not show any development of male cells in any of the sampled sites. The higher percentage of females with imposex matched with the higher boat traffic locality, and higher TBT level (Isla Caribe). No esterilization was evident in this work, nevertheless, the presence of TBT and Cu in the sediments and females with imposex were considered as a potential threat to V. musica populations in this region. In Venezuela there is no control over this particular issue, possibly because of the lack of information and research in this topic, but certainly, this information will be useful in biodiversity conservation policies.

  15. Paleoseismic Studies of the Peninsula San Andreas Fault at the Filoli Estate, Woodside, California

    NASA Astrophysics Data System (ADS)

    Prentice, C. S.; Clahan, K.; Sickler, R. R.; Salin, A.; DeLong, S. B.; McDermott, R.; Pickering, A.; Baldwin, J. N.

    2014-12-01

    The Peninsula section of the San Andreas Fault (SAFP) is within 10 km of downtown San Francisco, making it among the most significant sources of seismic hazard in the San Francisco Bay area. However, the history of earthquakes along this fault segment is poorly known. The most recent ground-rupturing earthquake occurred in 1906, but the dates of earlier surface-rupturing earthquakes on this segment remain uncertain. Earlier work at the Crystal Springs South trench site showed that a ground-rupturing paleo-earthquake occurred 830-930 Cal. yr BP, but poor stratigraphic resolution hampered our ability to determine whether or not earthquakes occurred between then and 1906. We combined existing airborne LiDAR data with newly-collected terrestrial laser scanner data to create a high-resolution digital elevation model that we used to guide the locations of two trenches at a new site near Scarp Creek on the Filoli Estate, about 0.5km to the southeast along the fault. The new trenches exposed a stratigraphic section of faulted fluvial, overbank, and lacustrine deposits overlying a massive colluvial deposit. Our preliminary results show evidence for at least three surface ruptures, including the 1906 earthquake, since deposition of the colluvial material. Preliminary radiocarbon analyses show that these three earthquakes occurred during the last 900 years. We expect that radiocarbon analyses of samples of the abundant organic material exposed in the trenches will constrain more closely the ages of the prehistoric events. In addition, we anticipate that additional work at this site will provide an opportunity to test our earlier results and will provide additional data to better constrain the timing of pre-1906 surface ruptures on the SAFP.

  16. [Imposex in Voluta musica (Caenogastropoda: Volutidae) from Northeastern Peninsula de Araya, Venezuela].

    PubMed

    Peralta, Ana Carolina; Miloslavich, Patricia; Bigatti, Gregorio

    2014-06-01

    Voluta musica is a dioecious marine gastropod endemic of the South Caribbean. Tributyltin (TBT) and copper (Cu) are potential inducers of imposex, an endocrine disorder by which females develop a penis and/or vas deferens. The goal of this work was to determine the imposex incidence in V. musica populations from Northeastern Peninsula de Araya. For this, we selected three sites (Isla Caribe, Isla Lobos and Bajo Cuspe) and made monthly samplings of 15 snails in each site, during one year, and determined: (1) sizes; (2) sex and imposex incidence and (3) the Relative Penis Length Index (RPLI). We also performed histological analysis of the gonads, and measured TBT and Cu concentrations in sediments from the studied localities. Our results showed that the total number of sampled females affected by imposex was 24.5% at Isla Caribe, 12% at Isla Lobos, and none at Bajo Cuspe. In sediments, Cu was detected mostly in Isla Lobos. The female gonads with imposex did not show any development of male cells in any of the sampled sites. The higher percentage of females with imposex matched with the higher boat traffic locality, and higher TBT level (Isla Caribe). No esterilization was evident in this work, nevertheless, the presence of TBT and Cu in the sediments and females with imposex were considered as a potential threat to V. musica populations in this region. In Venezuela there is no control over this particular issue, possibly because of the lack of information and research in this topic, but certainly, this information will be useful in biodiversity conservation policies. PMID:25102636

  17. Analysis of Glacial Change in the Northern Antarctic Peninsula Region Using Photogrammetry

    NASA Astrophysics Data System (ADS)

    Vargas, W.; Arkle, J.; Devillier, K.; Neely, N.; Velasco, A. A.

    2009-05-01

    Clearly and robustly documenting global climate change over this past century remains a key goal for researchers. Polar regions are an ideal place to study change, since they are particularly sensitive to temperature changes. As part of an International Polar Year (IPY) grant called IPY-ROAM (Research and Educational Opportunities in Antarctica for Minorities), faculty at the University of Texas at El Paso (UTEP) took 29 underrepresented minority students and teachers on a research expedition to Antarctica over winter break 2007. One goal of the program was to document glacial change along the Antarctic Peninsula over the past century using photogrammetry, a technique that uses photos to make accurate geographic measurements. Prior to embarkation, we gathered historic photos of glaciers along our travel route. During the expedition, new photos were taken within the old photo sites, where we made Global Positioning System (GPS) readings and accurately measurement angles to the geographic features. The geographic features (including top and bottom of a glacier) were then mapped onto a Geographical Information Systems (GIS) that allowed us to determine location, scale and distance to these features on the photos. With the angle and distance, the height difference between the old and current photo of the glacier was calculated using basic trigonometric functions. In one case, we determined a 14 m reduction in glacier height from 1934 to 2007. Future work will include analysis from more glaciers in the region, and to determine if there is a correlation between glacier retreat and climate change. ROAM/index.html

  18. The impact of sea surface temperature on winter wheat in Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Capa-Morocho, Mirian; Rodríguez-Fonseca, Belen; Ruiz-Ramos, Margarita

    2016-04-01

    Climate variability is the main driver of changes in crops yield, especially for rainfed production systems. This is also the case of Iberian Peninsula (IP) (Capa-Morocho et al., 2014), where wheat yields are strongly dependent on seasonal rainfall amount and temporal distribution of rainfall during the growing season. Previous works have shown that large-scale oceanic patterns have a significant impact on precipitation over IP (Rodriguez-Fonseca and de Castro, 2002; Rodríguez-Fonseca et al., 2006). The existence of some predictability of precipitation has encouraged us to analyze the possible predictability of the wheat yield in the IP using sea surface temperature (SST) anomalies as predictor. For this purpose, a crop model site specific calibrated for the Northeast of IP and several reanalysis climate datasets have been used to obtain long time series of attainable wheat yield and relate their variability with SST anomalies. The results show that wheat yield anomalies are associated with changes in the Tropical Pacific (El Niño) and Atlantic (TNA) SST. For these events, the regional associated atmospheric pattern resembles the NAO, which also influences directly on the maximum temperatures and precipitation experienced by the crop during flowering and grain filling. Results from this study could have important implications for predictability issues in agricultural planning and management, such as insurance coverage, changes in sowing dates and choice of species and varieties.

  19. The application of cooperative monitoring techniques to a conceptual limited deployment zone in the Korean peninsula

    SciTech Connect

    Vannoni, M.; Duggan, R.

    1996-10-01

    The Korean peninsula is the site of a tense military confrontation. Relations between North and South Korea improved during the early 1990`s but the process is now frozen. Confidence building measures, particularly military ones, that address the security needs of both countries would decrease the danger of conflict and help create an environment for direct negotiations. The Korean Institute for Defense Analysis (KIDA) analyzed current security conditions and options. Their scenario includes a conceptual agreement to establish Limited Force Deployment Zones (LDZ) along the current demilitarized zone (DMZ) to increase mutual security. The Cooperative Monitoring Center (CMC) of Sandia National Laboratories, in collaboration with KIDA, developed a strategy, with examples, for cooperatively monitoring the agreement. A cooperative monitoring regime requires consideration of the agreement`s terms, the geographic, logistic, military, and political factors of the Korean environment, and the capability of technology to monitor the terms. This paper assesses the applicability of cooperative monitoring to Korea, describes the monitoring strategy for the Korean enhanced DMZ scenario, and describes the applicable technologies and procedures.

  20. Holocene evolution of Dahab coastline - Gulf of Aqaba, Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Magdy, Torab

    2016-04-01

    Dahab was a little Bedouin-village in Sinai Peninsula at the mid-western coast of Gulf of Aqaba approx. 90 km north of Sharm-el-Sheikh City and it means "gold" in Arabic language. But in the past 20 years ago it becomes one of the most tourist sites in Egypt. The basement complex is composed mostly of biotiteaplite-granite, mica-aplitegranite, granodiorite, quartzdiorite, alaskite, and diorite. Based on correlation with similar igneous in the most southern part of Sinai and the Red Sea area. Wadi Dahab composed of igneous and metamorphic rocks and the coastline is formed of the fragments of its rocks, mixed with fragments of coral reef and fluvial deposits of Wadi Dahab. The morphology of Dahab coastline is characterized by hooked marine spit, which composed of fluvial sediments carried by marine current from wadi Dahab mouth, this spit encloses shallow lagoon, but the active deposition on the lagoon bottom will evaluate it into saline marsh. This paper dealing with the evolution of Dahab spit and lagoon during the Holocene in addition to the recent time for last 100 years, and it impacts of the future management of the coast area. The coastline mapping during the period of study depends upon GIS technique for data were collected during field measuring by using total station, aerial photo and satellite image interpretation as well as soil sample dating. Suggested geomorphological evolution of Dahab area during the Holocene depending upon geomorphic investigation of the sedimentological process into 6 stages.

  1. Block Volume Estimation from the Discontinuity Spacing Measurements of Mesozoic Limestone Quarries, Karaburun Peninsula, Turkey

    PubMed Central

    Elci, Hakan; Turk, Necdet

    2014-01-01

    Block volumes are generally estimated by analyzing the discontinuity spacing measurements obtained either from the scan lines placed over the rock exposures or the borehole cores. Discontinuity spacing measurements made at the Mesozoic limestone quarries in Karaburun Peninsula were used to estimate the average block volumes that could be produced from them using the suggested methods in the literature. The Block Quality Designation (BQD) ratio method proposed by the authors has been found to have given in the same order of the rock block volume to the volumetric joint count (Jv) method. Moreover, dimensions of the 2378 blocks produced between the years of 2009 and 2011 in the working quarries have been recorded. Assuming, that each block surfaces is a discontinuity, the mean block volume (Vb), the mean volumetric joint count (Jvb) and the mean block shape factor of the blocks are determined and compared with the estimated mean in situ block volumes (Vin) and volumetric joint count (Jvi) values estimated from the in situ discontinuity measurements. The established relations are presented as a chart to be used in practice for estimating the mean volume of blocks that can be obtained from a quarry site by analyzing the rock mass discontinuity spacing measurements. PMID:24696642

  2. Flavivirus isolations from mosquitoes collected from western Cape York Peninsula, Australia, 1999-2000.

    PubMed

    Johansen, Cheryl A; Nisbet, Debra J; Zborowski, Paul; van den Hurk, Andrew F; Ritchie, Scott A; Mackenzie, John S

    2003-12-01

    After the 1st appearance of Japanese encephalitis virus (JE) on mainland Australia in 1998, a study was undertaken to investigate whether JE had become established in enzootic transmission cycles on western Cape York Peninsula. Adult mosquitoes were collected during the late wet season from Kowanyama and Pormpuraaw in April 1999, and Pormpuraaw and Barr's Yard in April 2000. Despite processing 269,270 mosquitoes for virus isolation, no isolates of JE were obtained. However, other flaviviruses comprising Murray Valley encephalitis virus, Kunjin virus, Alfuy virus, and Kokobera virus (KOK) were isolated. Isolates of the alphaviruses Ross River virus, Barmah Forest virus (BF), and Sindbis virus (SIN) also were obtained. The majority (88%) of isolates were from members of the Culex sitiens subgroup. Single isolates of KOK, BF, and SIN were obtained from Ochlerotatus vigilax, Oc. normanensis, and Anopheles bancroftii, respectively. The isolations of flaviviruses during the late wet season indicate that conditions were suitable for flavivirus activity in the area. No evidence was found to suggest that JE has become established in enzootic transmission cycles on western Cape York, although study sites and field trips were limited. PMID:14710742

  3. First record of Mesopithecus (Cercopithecidae, Colobinae) from the Miocene of the Iberian Peninsula.

    PubMed

    Alba, David M; Montoya, Plini; Pina, Marta; Rook, Lorenzo; Abella, Juan; Morales, Jorge; Delson, Eric

    2015-11-01

    We report dental remains of the extinct colobine monkey Mesopithecus from the Turolian (MN13, Late Miocene, ca. 6.23 Ma) locality of Venta del Moro (Valencia, Spain). They include most of the deciduous dentition and the unerupted germs of the first molars of a single infantile individual, as well as two lower left lateral incisors from two additional individuals. On the basis of morphometric comparisons, mainly based on the M1s, these remains are attributed to the Late Miocene species Mesopithecus pentelicus. They represent a significant addition to the knowledge of the deciduous dentition of this taxon, much less well-known than the permanent dentition. Although this genus was widely distributed from the Late Miocene through the Pliocene across Europe, southwestern Asia, Pakistan, and China, until now its occurence in the Late Miocene of the Iberian Peninsula had not been documented conclusively. Hence, the reported remains considerably enlarge southwestwards the known geographic distribution of Mesopithecus. The presence of this genus at Venta del Moro must be understood within the framework of the significant faunal turnover that took place in European faunas during the latest Turolian (the second Messinian mammalian dispersal), which is further documented at this locality by the occurrence of other eastern immigrants. At the same time, the presence of M. pentelicus at this site agrees well with previous paleoenvironmental and sedimentological evidence, indicating a lacustrine depositional environment with strong hydrologic seasonality. PMID:26553814

  4. Block volume estimation from the discontinuity spacing measurements of mesozoic limestone quarries, Karaburun Peninsula, Turkey.

    PubMed

    Elci, Hakan; Turk, Necdet

    2014-01-01

    Block volumes are generally estimated by analyzing the discontinuity spacing measurements obtained either from the scan lines placed over the rock exposures or the borehole cores. Discontinuity spacing measurements made at the Mesozoic limestone quarries in Karaburun Peninsula were used to estimate the average block volumes that could be produced from them using the suggested methods in the literature. The Block Quality Designation (BQD) ratio method proposed by the authors has been found to have given in the same order of the rock block volume to the volumetric joint count (J(v)) method. Moreover, dimensions of the 2378 blocks produced between the years of 2009 and 2011 in the working quarries have been recorded. Assuming, that each block surfaces is a discontinuity, the mean block volume (V(b)), the mean volumetric joint count (J(vb)) and the mean block shape factor of the blocks are determined and compared with the estimated mean in situ block volumes (V(in)) and volumetric joint count (J(vi)) values estimated from the in situ discontinuity measurements. The established relations are presented as a chart to be used in practice for estimating the mean volume of blocks that can be obtained from a quarry site by analyzing the rock mass discontinuity spacing measurements. PMID:24696642

  5. In situ measurements of chlorinated hydrocarbons in the water column off the Palos Verdes Peninsula, California

    SciTech Connect

    Zeng, E.Y.; Yu, C.C.; Tran, K.

    1999-02-01

    Spatial distributions of DDT and its primary metabolites (DDTs) and polychlorinated biphenyls (PCBs) in the water column off the Palos Verdes Peninsula, CA, were measured in the winter and summer of 1997 using an in situ sampling method. The concentrations of DDTs ranged from 0.6 to 15.8 ng/L, while those of PCBs ranged from 0.06 to 15.8 ng/L, while those of PCBs ranged from 0.06 to 1.14 ng/L at eight sampling stations. The spatial distribution patterns of DDTs and PCBs as well as the DDT/PCB concentration ratio in the water column were similar to those found in the sediment, and the vertical profiles of DDTs and PCBs at both sampling seasons exponentially decreased with increasing distance from the sea floor. In addition, the partitioning characteristics of DDTs and selected PCB congeners indicated a tendency of mobilization from sediment to water. All of these findings strongly suggest that contaminated sediments are a main source of DDT and PCB inputs to the water column surrounding the study site.

  6. High resolution reconstruction of monthly autumn and winter precipitation of Iberian Peninsula for last 150 years.

    NASA Astrophysics Data System (ADS)

    Cortesi, N.; Trigo, R.; González-Hidalgo, J. C.; Ramos, A.

    2012-04-01

    Precipitation over Iberian Peninsula (IP) presents large values of interannual variability and large spatial contrasts between wet mountainous regions in the north and dry regions in the southern plains. Unlike other European regions, IP was poorly monitored for precipitation during 19th century. Here we present a new approach to fill this gap. A set of 26 atmospheric circulation weather types (Trigo R.M. and DaCamara C.C., 2000) derived from a recent SLP dataset, the EMULATE (European and North Atlantic daily to multidecadal climate variability) Project, was used to reconstruct Iberian monthly precipitation from October to March during 1851-1947. Principal Component Regression Analysis was chosen to develop monthly precipitation reconstruction back to 1851 and calibrated over 1948-2003 period for 3030 monthly precipitation series of high-density homogenized MOPREDAS (Monthly Precipitation Database for Spain and Portugal) database. Validation was conducted over 1920-1947 at 15 key site locations. Results show high model performance for selected months, with a mean coefficient of variation (CV) around 0.6 during validation period. Lower CV values were achieved in western area of IP. Trigo, R. M., and DaCamara, C.C., 2000: "Circulation weather types and their impact on the precipitation regime in Portugal". Int. J. Climatol., 20, 1559-1581.

  7. Holocene glacier fluctuations inferred from lacustrine sediment, Emerald Lake, Kenai Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    LaBrecque, Taylor S.; Kaufman, Darrell S.

    2016-01-01

    Physical and biological characteristics of lacustrine sediment from Emerald Lake were used to reconstruct the Holocene glacier history of Grewingk Glacier, southern Alaska. Emerald Lake is an ice-marginal threshold lake, receiving glaciofluvial sediment when Grewingk Glacier overtops the topographic divide that separates it from the lake. Sub-bottom acoustical profiles were used to locate core sites to maximize both the length and resolution of the sedimentary sequence recovered in the 4-m-long cores. The age model for the composite sequence is based on 13 14C ages and a 210Pb profile. A sharp transition from the basal inorganic mud to organic-rich mud at 11.4 ± 0.2 ka marks the initial retreat of Grewingk Glacier below the divide of Emerald Lake. The overlaying organic-rich mud is interrupted by stony mud that records a re-advance between 10.7 ± 0.2 and 9.8 ± 0.2 ka. The glacier did not spill meltwater into the lake again until the Little Ice Age, consistent with previously documented Little Ice Ages advances on the Kenai Peninsula. The retreat of Grewingk Glacier at 11.4 ka took place as temperature increased following the Younger Dryas, and the subsequent re-advance corresponds with a climate reversal beginning around 11 ka across southern Alaska.

  8. Foraging habitats of southern elephant seals, Mirounga leonina, from the Northern Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Muelbert, Monica M. C.; de Souza, Ronald B.; Lewis, Mirtha N.; Hindell, Mark A.

    2013-04-01

    Elephant Island (EI) is uniquely placed to provide southern elephant seals (SES) breeding there with potential access to foraging grounds in the Weddell Sea, the frontal zones of the South Atlantic Ocean, the Patagonian shelf and the Western Antarctic Peninsula (WAP). Quantifying where seals from EI forage therefore provides insights into the types of important habitats available, and which are of particular importance to elephant seals. Twenty nine SES (5 sub-adult males—SAM and 24 adult females—AF) were equipped with SMRU CTD-SLDRs during the post-breeding (PB 2008, 2009) and post-moulting (PM 2007, 2008, 2009, 2010) trips to sea. There were striking intra-annual and inter-sex differences in foraging areas, with most of the PB females remaining within 150 km of EI. One PB AF travelled down the WAP as did 16 out of the 20 PM females and foraged near the winter ice-edge. Most PM sub-adult males remained close to EI, in areas similar to those used by adult females several months earlier, although one SAM spent the early part of the winter foraging on the Patagonian Shelf. The waters of the Northern Antarctic Peninsula (NAP) contain abundant resources to support the majority of the Islands' SES for the summer and early winter, such that the animals from this population have shorter migrations than those from most other populations. Sub-adult males and PB females are certainly taking advantage of these resources. However, PM females did not remain there over the winter months, instead they used the same waters at the ice-edge in the southern WAP that females from both King George Island and South Georgia used. Females made more benthic dives than sub-adult males—again this contrasts with other sites where SAMs do more benthic diving. Unlike most other populations studied to date EI is a relatively southerly breeding colony located on the Antarctic continental shelf. EI seals are using shelf habitats more than other SES populations but some individuals still

  9. Transport pathway and depocenter of anthropogenic heavy metals off the Shandong Peninsula, China

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Liu, Jian; Pei, Shaofeng; Gao, Maosheng; Kong, Xianghuai

    2016-10-01

    Surface sediment grain size as well as the spatial distribution, sources and geochemical baseline levels of heavy metals in the south Shandong Peninsula clinoform were analyzed to determine the transport pathway and main depocenter of anthropogenic heavy metals off the peninsula. Results showed that the surface sediments were primarily silt-sized components, and the fine grain matter mainly originated from the Yellow River and rivers around Laizhou Bay. Heavy metals Cu, Pb, Zn, Cr, and Cd were predominantly from natural sources and their spatial distributions were controlled by grain size; conversely, anthropogenic As (concentration above geochemical baseline level 10.9 mg/kg) was principally derived from human activities, and its transportation from the Yellow River and Laizhou Bay was controlled by the Shandong Coastal Current off the Shandong Peninsula. Furthermore, the anthropogenic As was deposited in three main areas, that is, the Yellow River estuary, Laizhou Bay, and south Shandong Peninsula clinoform.

  10. Crustal Deformation Measurements Using Repeat-pass JERS 1 SAR Interferometry Near the Izu Peninsula, Japan

    NASA Technical Reports Server (NTRS)

    Fujiwara, Satoshi; Rosen, Paul A.; Tobita, Mikio; Murakami, Makoto

    1997-01-01

    We have examined the precision of interferometric SAR measurements of surface deformation of the Earth using 24-cm wavelength data acqured by the Japanese Earth Resources Satellite 1 (JERS 1) spacecraft, over the Izu Peninsula, Japan.

  11. Application of Space Technology to Discovery of Ancient Desert Trade Routes in the Southern Arabian Peninsula

    NASA Technical Reports Server (NTRS)

    Blom, Ronald; Crippen, Robert; Hedges, George; Zarins, Juris

    1997-01-01

    Over the last decade, an unusual combination of historical research, traditional archaeology, and application of space technolgy has demonstrated the existence of trans-desert trade routes in the sourthern Arabian peninsula.

  12. Hematology and serum chemistries of nestling bald eagles (Haliaeetus leucocephalus) in the lower peninsula of MI, USA.

    PubMed

    Bowerman, W W; Stickle, J E; Giesy, J P

    2000-11-01

    Hematology constituents and serum biochemistries were determined in blood collected from 55 nestling bald eagles (Haliaeetus leucocephalus) from nest sites within the lower peninsula of Michigan in 1992. Hematological values were comparable to published ranges for birds for all but eosinophils, which were greater than normal. Serum chemistry values were similar to those of other birds for all but six parameters, uric acid, cholesterol, alkaline phosphatase, total protein, globulin, and urea nitrogen, which were greater and glucose which was less. Samples of blood collected from wild bald eagles can be used for hematologic parameters and serum chemistry. It is important for other studies of endangered species to obtain baseline data from healthy, wild animals in their natural environment, and for comparison of animals living in environments of greater exposure to those living in areas of lesser exposure to xenobiotics. We caution that arrangements for rapid analysis be done in advance of sample collection.

  13. Increased Precipitation over the Yucatan Peninsula Inferred from the Spatial and Temporal Distribution of Late Holocene Foram Assemblages

    NASA Astrophysics Data System (ADS)

    Rachmallu, M.; Broach, K.; Paytan, A.; Street, J. H.

    2014-12-01

    As global climate warms, IPCC predictions suggest dry and seasonally dry regions will become dryer, increasing stress on water resources by growing urban populations (e.g. Southern California; Yucatan, Mexico). This study aims to reconstruct paleohydrologic trends during the late Holocene using foraminifera assemblages in Yucatan, Mexico to determine drought susceptibility in a region affected by migration of the Intertropical Convergence Zone (ITCZ). The ITCZ affects precipitation over the Yucatan Peninsula, potentially decreasing groundwater infiltration and thus reducing discharge in submarine springs at the peninsula margins. The field site Celestun Lagoon near Merida, Yucatan, Mexico, is dominated by spring and groundwater inputs at the northern terminus and opens to the Gulf of Mexico at the southern end resulting in a strong salinity gradient dependent on freshwater influx. We analyzed the foram assemblage in the top 6 cm of a set of 7 cores collected along a lagoonal transect (from the mouth to the head) and plotted the relative abundances of Ammonia beccarii, Elphidium sp., Quinqueloculina sp., and the ostracod Hemicyprideis cf. nichuptensis against site location. A. beccarii abundance increases from 40% near the head to 70% near the middle of the lagoon before dropping to <10% toward the saline lagoon mouth (high abundance in brackish salinity). Quinqueloculina sp. increases from 0% at the upper lagoon to nearly 40% near the mouth showing an opposite trend along the same transect. Elphidium sp. showed no clear trend (abundance range 10-28% throughout), and lowest H. nichuptensis abundance occurred at the middle of the lagoon (10%) increasing to the north and south (up to 60%). The inversely correlated spatial distribution between A. beccarii and Quinqueloculina sp. occurs vertically in an upper lagoon long core from 125-96 cm below sediment-water interface (14C age dates 3968-2820 ka), implying a decreasing salinity over ~1000 yrs and increased

  14. Polygonal tundra geomorphological change in response to warming alters future CO2 and CH4 flux on the Barrow Peninsula.

    PubMed

    Lara, Mark J; McGuire, A David; Euskirchen, Eugenie S; Tweedie, Craig E; Hinkel, Kenneth M; Skurikhin, Alexei N; Romanovsky, Vladimir E; Grosse, Guido; Bolton, W Robert; Genet, Helene

    2015-04-01

    The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate, and extreme scenarios of thermokarst pit formation (10%, 30%, and 50%) reported for Alaskan arctic tundra sites. We developed a 30 × 30 m resolution tundra geomorphology map (overall accuracy:75%; Kappa:0.69) for our ~1800 km² study area composed of ten classes; drained slope, high center polygon, flat-center polygon, low center polygon, coalescent low center polygon, polygon trough, meadow, ponds, rivers, and lakes, to determine their spatial distribution across the Barrow Peninsula. Land-atmosphere CO2 and CH4 flux data were collected for the summers of 2006-2010 at eighty-two sites near Barrow, across the mapped classes. The developed geomorphic map was used for the regional assessment of carbon flux. Results indicate (i) at present during peak growing season on the Barrow Peninsula, CO2 uptake occurs at -902.3 10(6) gC-CO2 day(-1) (uncertainty using 95% CI is between -438.3 and -1366 10(6) gC-CO2 day(-1)) and CH4 flux at 28.9 10(6) gC-CH4 day(-1) (uncertainty using 95% CI is between 12.9 and 44.9 10(6) gC-CH4 day(-1)), (ii) one century of future landscape change associated with the thaw-lake cycle only slightly alter CO2 and CH4 exchange, while (iii) moderate increases in thermokarst pits would strengthen both CO2 uptake (-166.9 10(6) gC-CO2 day(-1)) and CH4 flux (2.8 10(6) gC-CH4 day(-1)) with geomorphic change from low

  15. Polygonal tundra geomorphological change in response to warming alters future CO2 and CH4 flux on the Barrow Peninsula.

    PubMed

    Lara, Mark J; McGuire, A David; Euskirchen, Eugenie S; Tweedie, Craig E; Hinkel, Kenneth M; Skurikhin, Alexei N; Romanovsky, Vladimir E; Grosse, Guido; Bolton, W Robert; Genet, Helene

    2015-04-01

    The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate, and extreme scenarios of thermokarst pit formation (10%, 30%, and 50%) reported for Alaskan arctic tundra sites. We developed a 30 × 30 m resolution tundra geomorphology map (overall accuracy:75%; Kappa:0.69) for our ~1800 km² study area composed of ten classes; drained slope, high center polygon, flat-center polygon, low center polygon, coalescent low center polygon, polygon trough, meadow, ponds, rivers, and lakes, to determine their spatial distribution across the Barrow Peninsula. Land-atmosphere CO2 and CH4 flux data were collected for the summers of 2006-2010 at eighty-two sites near Barrow, across the mapped classes. The developed geomorphic map was used for the regional assessment of carbon flux. Results indicate (i) at present during peak growing season on the Barrow Peninsula, CO2 uptake occurs at -902.3 10(6) gC-CO2 day(-1) (uncertainty using 95% CI is between -438.3 and -1366 10(6) gC-CO2 day(-1)) and CH4 flux at 28.9 10(6) gC-CH4 day(-1) (uncertainty using 95% CI is between 12.9 and 44.9 10(6) gC-CH4 day(-1)), (ii) one century of future landscape change associated with the thaw-lake cycle only slightly alter CO2 and CH4 exchange, while (iii) moderate increases in thermokarst pits would strengthen both CO2 uptake (-166.9 10(6) gC-CO2 day(-1)) and CH4 flux (2.8 10(6) gC-CH4 day(-1)) with geomorphic change from low

  16. An assessment of heat stress in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Rasilla Álvarez, D.; Fernandez García, F.

    2010-09-01

    The analysis of human comfort requires the inclusion of additional parameters to air temperature, such as wind, humidity or radiation, especially in areas like the Iberian Peninsula, where the summer thermal differences between the marine surfaces and the continent promotes local circulations capable to modify locally the characteristics of the air masses. A variety of bioclimatic indices that relate atmospheric conditions to human sensations have been developed so far, being the Physiological Equivalent Temperature (PET, Matzarakis et al, 1999) one of the most popular. Several objectives have guided this research. First, a basic climatology of PET over the Iberian Peninsula has been elaborated. Secondly, the main modes of spatial and temporal variability in the apparent temperature field have been obtained. Aditionally, the role of the regional atmospheric circulation and local surface variables in the spatial and temporal variability of PET has been analyzed through a synoptic climatological approach. The data used have been 3 hourly synop reports from stations located in the Iberian Peninsula, Southern France and Northern Africa (Morocco and Argelia), for the period 1971-2007. 850 hPa geopotential heights, retrieved from NCEP Reanalysis web server (http://www.esrl.noaa.gov/psd/data/reanalysis/reanalysis.shtml) were used to devise a circulation pattern catalogue, obtained following a well-known procedure that combines Principal Component Analysis (PCA) for reduction purposes and clustering (Ward plus K-means) to define the types. Additional gridded variables, like 850 u/v wind components and 850 relative humidity fields were also used to obtain composites of the synoptic patterns. The methodology followed comprised several steps. Initially, 3 hourly values of PET corresponding to selected stations was calculated with RayMan. The 12 UTC values were subsequently submitted to a regionalization using a Rotated Principal Component Analysis. The frequency of occurrence

  17. Recent Antarctic Peninsula warming relative to Holocene climate and ice-shelf history.

    PubMed

    Mulvaney, Robert; Abram, Nerilie J; Hindmarsh, Richard C A; Arrowsmith, Carol; Fleet, Louise; Triest, Jack; Sime, Louise C; Alemany, Olivier; Foord, Susan

    2012-09-01

    Rapid warming over the past 50 years on the Antarctic Peninsula is associated with the collapse of a number of ice shelves and accelerating glacier mass loss. In contrast, warming has been comparatively modest over West Antarctica and significant changes have not been observed over most of East Antarctica, suggesting that the ice-core palaeoclimate records available from these areas may not be representative of the climate history of the Antarctic Peninsula. Here we show that the Antarctic Peninsula experienced an early-Holocene warm period followed by stable temperatures, from about 9,200 to 2,500 years ago, that were similar to modern-day levels. Our temperature estimates are based on an ice-core record of deuterium variations from James Ross Island, off the northeastern tip of the Antarctic Peninsula. We find that the late-Holocene development of ice shelves near James Ross Island was coincident with pronounced cooling from 2,500 to 600 years ago. This cooling was part of a millennial-scale climate excursion with opposing anomalies on the eastern and western sides of the Antarctic Peninsula. Although warming of the northeastern Antarctic Peninsula began around 600 years ago, the high rate of warming over the past century is unusual (but not unprecedented) in the context of natural climate variability over the past two millennia. The connection shown here between past temperature and ice-shelf stability suggests that warming for several centuries rendered ice shelves on the northeastern Antarctic Peninsula vulnerable to collapse. Continued warming to temperatures that now exceed the stable conditions of most of the Holocene epoch is likely to cause ice-shelf instability to encroach farther southward along the Antarctic Peninsula.

  18. Holocene tephrochronology of the Cold Bay area, southwest Alaska Peninsula

    USGS Publications Warehouse

    Carson, E.C.; Fournelle, J.H.; Miller, T.P.; Mickelson, D.M.

    2002-01-01

    The major-element glass geochemistry of 92 tephra samples from the southwest Alaska Peninsula provides the basis for establishing a Holocene tephrochronology for the region. Electron microprobe analysis has been combined with field descriptions of samples, stratigraphic relationships between tephra samples and sample localities, and glass shard micro-morphology to correlate these sampled distal tephra units throughout the area of Cold Bay and adjacent Morzhovoi Bay. Radiocarbon dating provides age constraints on correlated horizons. Previous research had clearly delineated only one horizon in the region, the so-called 'Funk/Fisher' ash, dating to between 8425 ?? 350 and 9130 ?? 140 14C yr BP. In addition to constraining the bimodal andesitic and dacitic glass chemistry of that horizon, this study has recognized six additional tephra layers in the area. Two horizons pre-date the Funk/Fisher ash and four are younger than it. A tephra containing dacitic and andesitic components was identified in the vicinity of Morzhovoi Bay, with a minimum age of 9300 ?? 80 14C yr BP and a maximum age of 10,200 ?? 75 14C yr BP. A rhyolitic horizon composed of cm-sized, rounded pumice clasts was identified in the vicinity of Cold Bay; it has been correlated to the ca 9500 BP eruption of Roundtop volcano on Unimak Island. The four younger tephra beds date to between 6070 ?? 340 and 3600 ?? 140 14C yr BP. The oldest of the four is rhyodacitic, followed by a mixed rhyodacitic-andesitic horizon, another rhyodacitic horizon, and finally an andesitic layer. Comparison of all the correlated horizons to proximal samples collected on Unimak Island provides conclusive geochemical evidence that the ca 9100 BP Caldera-forming eruption of Fisher volcano is the source of the Funk/Fisher ash. Correlation between the rhyodacitic tephra horizons and proximal samples from Fisher volcano suggests that Fisher Caldera is the source of one of the rhyodacitic tephra horizons that post-dates the Funk

  19. Stand structure and dynamics of sand pine differ between the Florida panhandle and peninsula

    USGS Publications Warehouse

    Drewa, P.B.; Platt, W.J.; Kwit, C.; Doyle, T.W.

    2008-01-01

    Size and age structures of stand populations of numerous tree species exhibit uneven or reverse J-distributions that can persist after non-catastrophic disturbance, especially windstorms. Among disjunct populations of conspecific trees, alternative distributions are also possible and may be attributed to more localized variation in disturbance. Regional differences in structure and demography among disjunct populations of sand pine (Pinus clausa (Chapm. ex Engelm.) Vasey ex Sarg.) in the Florida panhandle and peninsula may result from variation in hurricane regimes associated with each of these populations. We measured size, age, and growth rates of trees from panhandle and peninsula populations and then compiled size and age class distributions. We also characterized hurricanes in both regions over the past century. Size and age structures of panhandle populations were unevenly distributed and exhibited continuous recruitment; peninsula populations were evenly sized and aged and exhibited only periodic recruitment. Since hurricane regimes were similar between regions, historical fire regimes may have been responsible for regional differences in structure of sand pine populations. We hypothesize that fires were locally nonexistent in coastal panhandle populations, while periodic high intensity fires occurred in peninsula populations over the past century. Such differences in local fire regimes could have resulted in the absence of hurricane effects in the peninsula. Increased intensity of hurricanes in the panhandle and current fire suppression patterns in the peninsula may shift characteristics of sand pine stands in both regions. ?? 2007 Springer Science+Business Media B.V.

  20. Preliminary geothermal evaluation of the Mokapu Peninsula on the Island of Oahu, Hawaii

    SciTech Connect

    Not Available

    1981-08-01

    Preliminary geological, geochemical, and geophysical field surveys have been conducted on Mokapu Peninsula on the island of Oahu in an effort to determine whether sufficient indications of geothermal potential exist within or adjacent to the peninsula to justify further, more detailed, exploratory efforts. An evaluation of existing geologic data as well as recently completed mapping on Mokapu indicate that the peninsula is located on the edge of or immediately adjacent to the inferred caldera of Koolau volcano. Geochemical surveys conducted within and around the Mokapu Peninsula included mercury and radon ground gas surveys as well as a limited evaluation of groundwater chemistry. Groundwater sampling on Mokapu Peninsula was severely restricted due to the absence of wells within the study area and thus water chemistry analyses were limited to the Nuupia fish ponds. Schlumberger resistivity soundings were completed in three locations on the peninsula: KVS1, in the northeast quadrant within the Ulupau crater, KVS2 in the northwest quadrant along the main jet runway, and KVS3 in the southeast along Mokapu Road. KVS1 encountered a relatively high resistivity to a depth of approximately 20 meters below sea level which was underlain by a basement resistivity of about 2 to 3 ohm meters. KVS2 and KVS3 detected similar resistivities of 2 to 3 ohm meters at much shallower depths (approximately equivalent to local sea level) below a thin, moderately resistive layer having an impedance ranging from 15 to 118 ohm meters.

  1. Development of a diagnosis index of tropical cyclones affecting the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Won; Cha, Yumi

    2016-06-01

    This study has developed the index for diagnosis on possibility that tropical cyclones (TCs) affect Korean Peninsula. This index is closely related to the strength of the western North Pacific subtropical high (WNPSH), which is calculated as a difference in meridional wind between at the highest correlation area (around Korean Peninsula) and at the lowest correlation area (sea southeast of Japan) through a correlation analysis between TC frequency that affects Korean Peninsula and 500 hPa meridional wind. In low frequency years that selected from Korea affecting TC index, anomalous northeasterly is strengthened from Korea to the South China Sea because the center of anomalous anticyclonic circulation is located to northwest of Korean Peninsula. Thus, TCs tend to move westward from the sea east of the Philippines to the mainland China. On the other hand, in high frequency years, anomalous southwesterly serves as steering flow that more TCs move toward Korean Peninsula because the center of anomalous anticyclonic circulation is located to sea east of Japan. Consequently, this study suggests that if this index is calculated using real time 500 hPa meridional winds that forecasted by dynamic models during the movement of TCs, the possibility that TCs approach Korean Peninsula can be diagnosed in real time.

  2. Assemblages of micronektonic fishes and invertebrates in a gradient of regional warming along the Western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Parker, Melanie L.; Fraser, William R.; Ashford, Julian; Patarnello, Tomaso; Zane, Lorenzo; Torres, Joseph J.

    2015-12-01

    Micronektonic fishes and invertebrates were sampled with 32 midwater trawls at nine sites along the Western Antarctic Peninsula (WAP) in the austral fall (March-April) of 2010. Study sites were located within four hypothesized hydrographic regions: near Joinville Island in Region I, at Croker Passage, near Anvers Island, and near Renaud Island in Region II, within Marguerite Bay and the Marguerite Trough in Region III, and near Charcot Island in Region IV. A total of 62 taxa representing 12 taxonomic groups of pelagic invertebrates and 9 families of fish were captured, but assemblages were dominated by only a few species. The most numerically abundant taxa were the euphausiids, Thysanoessa macrura, Euphausia superba, and E. crystallorophias, combining to contribute nearly 79% of the total catch. Biomass dominants included E. superba, which contributed more than 44% of the total catch, the notothenioid Pleuragramma antarctica, and the salp, Salpa thompsoni. A comparison of total catches among sites revealed that the largest volumetric abundances and biomasses were captured at the Marguerite Bay site. Cluster analysis of abundance data identified distinct multispecies assemblages at Joinville Island in Region I, Croker Passage in Region II, Marguerite Bay in Region III, and Charcot Island in Region IV. A fifth distinct assemblage included samples from sites near Anvers and Renaud Island in Region II, and from the Marguerite Trough in Region III. Assemblages at Joinville Island and Croker Passage were both dominated by E. superba and S. thompsoni, but hydrographic conditions at Joinville Island favored a neritic assemblage, underscored by substantial numbers of P. antarctica. The assemblage at Croker Passage was more oceanic in nature with major inputs from the myctophid, Electrona antarctica and the hyperiid amphipod, Themisto gaudichaudii. Marguerite Bay and Charcot Island were well-mixed assemblages with strong representation by both neritic and oceanic fauna. The

  3. Active layer thermal monitoring at Fildes Peninsula, King George Island, Maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Michel, R. F. M.; Schaefer, C. E. G. R.; Simas, F. N. B.; Francelino M., R.; Fernandes-Filho, E. I.; Lyra, G. B.; Bockheim, J. G.

    2014-07-01

    International attention to the climate change phenomena has grown in the last decade; the active layer and permafrost are of great importance in understanding processes and future trends due to their role in energy flux regulation. The objective of the this paper is to present active layer temperature data for one CALM-S site located at Fildes Peninsula, King George Island, Maritime Antarctica over an fifth seven month period (2008-2012). The monitoring site was installed during the summer of 2008 and consists of thermistors (accuracy of ± 0.2 °C), arranged vertically with probes at different depths, recording data at hourly intervals in a~high capacity data logger. A series of statistical analysis were performed to describe the soil temperature time series, including a linear fit in order to identify global trend and a series of autoregressive integrated moving average (ARIMA) models were tested in order to define the best fit for the data. The controls of weather on the thermal regime of the active layer have been identified, providing insights about the influence of climate chance over the permafrost. The active layer thermal regime in the studied period was typical of periglacial environment, with extreme variation at the surface during summer resulting in frequent freeze and thaw cycles. The active layer thickness (ALT) over the studied period showed variability related to different annual weather conditions, reaching a maximum of 117.5 cm in 2009. The ARIMA model was considered appropriate to treat the dataset, enabling more conclusive analysis and predictions when longer data sets are available. Despite the variability when comparing temperature readings and active layer thickness over the studied period, no warming trend was detected.

  4. Active-layer thermal monitoring on the Fildes Peninsula, King George Island, maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Michel, R. F. M.; Schaefer, C. E. G. R.; Simas, F. M. B.; Francelino, M. R.; Fernandes-Filho, E. I.; Lyra, G. B.; Bockheim, J. G.

    2014-12-01

    International attention to climate change phenomena has grown in the last decade; the active layer and permafrost are of great importance in understanding processes and future trends due to their role in energy flux regulation. The objective of this paper is to present active-layer temperature data for one Circumpolar Active Layer Monitoring South hemisphere (CALM-S) site located on the Fildes Peninsula, King George Island, maritime Antarctica over an 57-month period (2008-2012). The monitoring site was installed during the summer of 2008 and consists of thermistors (accuracy of ±0.2 °C), arranged vertically with probes at different depths, recording data at hourly intervals in a high-capacity data logger. A series of statistical analyses was performed to describe the soil temperature time series, including a linear fit in order to identify global trends, and a series of autoregressive integrated moving average (ARIMA) models was tested in order to define the best fit for the data. The affects of weather on the thermal regime of the active layer have been identified, providing insights into the influence of climate change on permafrost. The active-layer thermal regime in the studied period was typical of periglacial environments, with extreme variation in surface during the summer resulting in frequent freeze and thaw cycles. The active-layer thickness (ALT) over the studied period shows a degree of variability related to different annual weather conditions, reaching a maximum of 117.5 cm in 2009. The ARIMA model could describe the data adequately and is an important tool for more conclusive analysis and predictions when longer data sets are available. Despite the variability when comparing temperature readings and ACT over the studied period, no trend can be identified.

  5. Geomorphological and geochemistry changes in permafrost after the 2002 tundra wildfire in Kougarok, Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Iwahana, Go; Harada, Koichiro; Uchida, Masao; Tsuyuzaki, Shiro; Saito, Kazuyuki; Narita, Kenji; Kushida, Keiji; Hinzman, Larry D.

    2016-09-01

    Geomorphological and thermohydrological changes to tundra, caused by a wildfire in 2002 on the central Seward Peninsula of Alaska, were investigated as a case study for understanding the response from ice-rich permafrost terrain to surface disturbance. Frozen and unfrozen soil samples were collected at burned and unburned areas, and then water isotope geochemistry and cryostratigraphy of the active layer and near-surface permafrost were analyzed to investigate past hydrological and freeze/thaw conditions and how this information could be recorded within the permafrost. The development of thermokarst subsidence due to ice wedge melting after the fire was clear from analyses of historical submeter-resolution remote sensing imagery, long-term monitoring of thermohydrological conditions within the active layer, in situ surveys of microrelief, and geochemical signals recorded in the near-surface permafrost. The resulting polygonal relief coincided with depression lines along an underground ice wedge network, and cumulative subsidence to 2013 was estimated as at least 10.1 to 12.1 cm (0.9-1.1 cm/year 11 year average). Profiles of water geochemistry in the ground indicated mixing or replenishment of older permafrost water with newer meteoric water, as a consequence of the increase in active layer thickness due to wildfire or past thaw event. Our geocryological analysis of cores suggests that permafrost could be used to reconstruct the permafrost degradation history for the study site. Distinct hydrogen and oxygen isotopic compositions above the Global Meteoric Water Line were found for water from these sites where permafrost degradation with geomorphological change and prolonged surface inundation were suggested.

  6. Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

    PubMed

    Roa-Fuentes, Lilia L; Templer, Pamela H; Campo, Julio

    2015-10-01

    Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

  7. Feasibility study concerning remediation and rehabilitation of industrial polluted lands on the Absheron Peninsula, Republic of Azerbaijan

    NASA Astrophysics Data System (ADS)

    Pivin, Majorie; Helsen, Stefan; Cuyvers, Lars

    2014-05-01

    ECOREM is carrying out a feasibility study focused on the remediation and rehabilitation of industrial polluted lands, located on the Absheron Peninsula (Republic of Azerbaijan), on behalf of the State Oil Company of Azerbaijan Republic (SOCAR). The objective of this study is to support SOCAR with specific technologies and capacity building for environmental remediation works on various sectors of the Peninsula. As an independent consultancy company, ECOREM provides sustainable and quality advice, seeking the balance to the interests of the client and the environment in the broadest sense of the word. Within this study, it is important to underline that extraction activities in the country have been going on for more than a century. Given that the age of the environmental problems is equal to the history of the oil production, it is nearly impossible to point out the responsibilities of the various companies or to define the exact activities that occurred on a particular location. From the data gathered so far, more than 3600 ha of oil contaminated area are known in Baku and the Absheron Peninsula. Within this feasibility study, ECOREM will advice SOCAR on suitable and best available remediation technologies to apply on prior contaminated areas. According to the Environmental Policy of the Company, SOCAR would like to act in priority on the numerous contaminated lands of the Absheron Peninsula. Through the exploitation of the extensive GIS database provided by SOCAR, the oil contaminated sites will be examined in details in order to determine the most sensitive areas, on which remediation works or monitoring should be implemented in priority. To locate these sites, ECOREM will provide SOCAR with technical support in order to conduct risk analysis, remediation and monitoring of soil and/or groundwater oil pollutions. According to these results, practical solutions will be proposed concerning the possible reuse and management of contaminated soils and hazardous

  8. Methylmercury monitoring study in Karakuwacho peninsula area in Japan.

    PubMed

    Yan, Junxia; Inoue, Kayoko; Asakawa, Akihiro; Harada, Kouji H; Watanabe, Takao; Hachiya, Noriyuki; Koizumi, Akio

    2014-07-01

    Methylmercury (MeHg) is a worldwide concern owing to its adverse health effects. To explore MeHg exposure burdens and the potential contributing factors in different subpopulations in a peninsula area (Karakuwacho) in Japan, a cross-sectional survey was performed. This study included 189 individuals from 102 families. The geometric means of total hair mercury (THg) were 5.74, 3.78 and 2.37 μg/g for adult males, females and children, respectively, of which 56.5 %, 30.9 % and 12.9 % had hair THg exceeding 5 μg/g, respectively. Tuna and mackerel were the common fish species that were positively correlated with hair THg levels in different subpopulations (standardized coefficient ranged from 0.20 to 0.58, p < 0.05). Frequent consumption of these fish species and a large amount of fish intake are likely major contributors of MeHg exposure in this area. Local-scale risk evaluation and risk communication should be highlighted in future studies.

  9. [Microbiological analysis of cryopegs from the Varandei Peninsula, Barents Sea].

    PubMed

    Pecheritsyna, S A; Shcherbakova, V A; Kholodov, A L; Akimov, V N; Abashina, T N; Suzina, N E; Rivkina, E M

    2007-01-01

    The paper deals with the microbiological characterization of water-saturated horizons in permafrost soils (cryopegs) found on the Varandei Peninsula (Barents Sea coast), 4-20 m deep. The total quantity of bacteria in the water of cryopegs was 3.5 x 10(8) cells/ml. The population of cultivated aerobic heterotrophic bacteria was 3-4 x 10(7) cells/ml and the number of anaerobic heterotrophic bacteria varied from 10(2) to 10(5) cells/ml depending on cultivation temperature and salinity. Sulfate-reducing bacteria and methanogenic archaea were found as hundreds and tens of cells per ml of water, respectively. A pure culture of a sulfate-reducing strain B15 was isolated from borehole 21 and characterized. Phylogenetic analysis has shown that the new bacterium is a member of the genus Desulfovibrio with Desulfovibrio mexicanus as its closest relative (96.5% similarity). However, the significant phenotypic differences suggest that strain B15 is a new species of sulfate-reducing bacteria. PMID:18069331

  10. Methylmercury monitoring study in Karakuwacho peninsula area in Japan.

    PubMed

    Yan, Junxia; Inoue, Kayoko; Asakawa, Akihiro; Harada, Kouji H; Watanabe, Takao; Hachiya, Noriyuki; Koizumi, Akio

    2014-07-01

    Methylmercury (MeHg) is a worldwide concern owing to its adverse health effects. To explore MeHg exposure burdens and the potential contributing factors in different subpopulations in a peninsula area (Karakuwacho) in Japan, a cross-sectional survey was performed. This study included 189 individuals from 102 families. The geometric means of total hair mercury (THg) were 5.74, 3.78 and 2.37 μg/g for adult males, females and children, respectively, of which 56.5 %, 30.9 % and 12.9 % had hair THg exceeding 5 μg/g, respectively. Tuna and mackerel were the common fish species that were positively correlated with hair THg levels in different subpopulations (standardized coefficient ranged from 0.20 to 0.58, p < 0.05). Frequent consumption of these fish species and a large amount of fish intake are likely major contributors of MeHg exposure in this area. Local-scale risk evaluation and risk communication should be highlighted in future studies. PMID:24599146

  11. Seismic hazard of the Iberian Peninsula: evaluation with kernel functions

    NASA Astrophysics Data System (ADS)

    Crespo, M. J.; Martínez, F.; Martí, J.

    2014-05-01

    The seismic hazard of the Iberian Peninsula is analysed using a nonparametric methodology based on statistical kernel functions; the activity rate is derived from the catalogue data, both its spatial dependence (without a seismogenic zonation) and its magnitude dependence (without using Gutenberg-Richter's relationship). The catalogue is that of the Instituto Geográfico Nacional, supplemented with other catalogues around the periphery; the quantification of events has been homogenised and spatially or temporally interrelated events have been suppressed to assume a Poisson process. The activity rate is determined by the kernel function, the bandwidth and the effective periods. The resulting rate is compared with that produced using Gutenberg-Richter statistics and a zoned approach. Three attenuation relationships have been employed, one for deep sources and two for shallower events, depending on whether their magnitude was above or below 5. The results are presented as seismic hazard maps for different spectral frequencies and for return periods of 475 and 2475 yr, which allows constructing uniform hazard spectra.

  12. Seismic hazards of the Iberian Peninsula - evaluation with kernel functions

    NASA Astrophysics Data System (ADS)

    Crespo, M. J.; Martínez, F.; Martí, J.

    2013-08-01

    The seismic hazard of the Iberian Peninsula is analysed using a nonparametric methodology based on statistical kernel functions; the activity rate is derived from the catalogue data, both its spatial dependence (without a seismogenetic zonation) and its magnitude dependence (without using Gutenberg-Richter's law). The catalogue is that of the Instituto Geográfico Nacional, supplemented with other catalogues around the periphery; the quantification of events has been homogenised and spatially or temporally interrelated events have been suppressed to assume a Poisson process. The activity rate is determined by the kernel function, the bandwidth and the effective periods. The resulting rate is compared with that produced using Gutenberg-Richter statistics and a zoned approach. Three attenuation laws have been employed, one for deep sources and two for shallower events, depending on whether their magnitude was above or below 5. The results are presented as seismic hazard maps for different spectral frequencies and for return periods of 475 and 2475 yr, which allows constructing uniform hazard spectra.

  13. Birds of the Northcentral Alaska Peninsula, 1976-1980

    USGS Publications Warehouse

    Gill, Jr.; Petersen, M.R.; Jorgensen, P.D.

    1981-01-01

    Between spring 1976 and fall 1980 we studied the occurrence, abundance, and habitat use of birds over a 2000 square km segment of the northcentral Alaska Peninsula. During this period observers were present 473 days and obtained records for all seasons. A total of 125 species was recorded; 63% (79 of 125) were water-associated. The breeding avifauna was found to be a mixture of Panboreal (49%), North American (34%), and Aleutican (17%) species. The Aleutican group was dominant in terms of biomass and numbers of individuals during the nonbreeding period. Forty-two species were confirmed breeding in the area and another 19 were suspected of breeding. The majority of birds occurred as migrants; 14 species were considered permanent residents and an additional 20 were winter residents. ... The area is a principal late summer and fall molting and staging area for several species of arctic and subarctic nesting waders and seaducks and emperor geese .... From late September through mid-October the density of water birds over the entire littoral and nearshore area approached 1000 birds square km. This density was exceeded many fold for certain species on particular segments of habitats in the area.

  14. Stratigraphy and paleogeography of the Cretaceous in Arabian Peninsula

    SciTech Connect

    Alsharhan, A.S.; Nairn, A.E.M.

    1986-05-01

    The Cretaceous of the Arabian Peninsula is divided into three major units by regional unconformities: Lower Cretaceous Thamama Group (Berriasian-middle Aptian), middle Cretaceous Wasia Group (Albian-Turonian), and Upper Cretaceous Aruma Group (Coniacian-Maestrichtian). The profusion of named stratigraphic units in the area reflects not only the lithologic variation resulting from facies changes, but also terminologies adopted by different companies. The authors provide a stratigraphic nomenclature defining standard type sections and indicate synonymies, which follow the recommendation of 10th Geological Liaison Meeting and hence are acceptable to operators in the area. The sedimentologic history of the area was presented in a series of paleogeographic maps, which they relate to the regional tectonic framework. The maps show a predominantly carbonate shelf ramp bordering a land area to the north and west. The principal change in depositional environment occurs during the Upper Cretaceous, as a result of tectonic activity. Less significant changes are attributed to eustatic sea level fluctuations, on which tilting caused by tectonic movement may be superposed during the Lower and middle Cretaceous. The major producing horizons lie below the regional unconformities; secondary porosity in the shelf reefal buildups was developed during subaerial exposure in the Shuaiba Formation (early-middle Aptian), in the Mishrif Formation (late Cenomanian), and in the Simsima Formation (Maestrichtian).

  15. [Mycobiota of soil and anthropogenic substrates of the Yamal Peninsula].

    PubMed

    Vlasov, D Yu; Abakumov, E V; Tomashunas, V M; Krylenkov, V A; Zelenskaya, M S

    2014-01-01

    There are presented results of mycological examination of samples of soil and anthropogenic substrates, collected on the Yamal Peninsula. 40 species of micromycetes have been identified. The obtained results indicate to the qualitative difference in the complexes of micromycetes from soil and anthropogenic substrates in the examined area. On anthropogenic substrates dark-colored fungi were dominated Predominant group were known destructors of different materials and commensal human pathogens also. In soil samples from different depths species of the genus Penicillium and fungi of the genus Fusarium dominated clearly, that is quite typical for tundra soils. There is noted a general downward trend in species diversity and abundance of micromycetes with the increasing of the depth of the soil and the frozen ground. In the surface layer of soil there may occur species capable to move to man-made materials. The data obtained shows the feasibility of using the structure of complexes of micromycetes as an indicator index of anthropogenic impact on Arctic ecosystems.

  16. Recent increase in Antarctic Peninsula ice core uranium concentrations

    NASA Astrophysics Data System (ADS)

    Potocki, Mariusz; Mayewski, Paul A.; Kurbatov, Andrei V.; Simões, Jefferson C.; Dixon, Daniel A.; Goodwin, Ian; Carleton, Andrew M.; Handley, Michael J.; Jaña, Ricardo; Korotkikh, Elena V.

    2016-09-01

    Understanding the distribution of airborne uranium is important because it can result in both chemical and radiological toxicity. Ice cores offer the most robust reconstruction of past atmospheric levels of toxic substances. Here we present the first sub-annually dated, continuously sampled ice core documenting change in U levels in the Southern Hemisphere. The ice core was recovered from the Detroit Plateau, northern Antarctic Peninsula, in 2007 by a joint Brazilian-Chilean-US team. It displays a significant increase in U concentration that coincides with reported mining activities in the Southern Hemisphere, notably Australia. Raw U concentrations in the Detroit Plateau ice core increased by as much as 102 between the 1980s and 2000s accompanied by increased variability in recent years. Decadal mean U concentrations increased by a factor of ∼3 from 1980 to 2007, reaching a mean of 205 pg/L from 2000 to 2007. The fact that other terrestrial source dust elements such as Ce, La, Pr, and Ti do not show a similar increase and that the increased U concentrations are enriched above natural crustal levels, supports an anthropogenic source for the U as opposed to a change in atmospheric circulation.

  17. Pumice deposits in the Alaska Peninsula-Cook Inlet region

    USGS Publications Warehouse

    Moxham, R.M.

    1952-01-01

    Three principal areas of pumice deposition have been found in the Alaska Peninsula-Cook Inlet region: Katmai National Monument, Augustine Island, and the Veniaminof-Aniakchak area. Vast quantities of pumice were deposited in Katmai National Monument resulting from the eruption of Mt. Katmai and related volcanic action in 1912. The principal deposits in the coastal areas of the Monument occur in the valley of the Katmai River and in the Amalik Bay-Kukak Bay area. Several areas of pumice deposition have been found on the south and west sides of Augustine Island, located 200 miles southwest of Anchorage. Mining was carried on by the Alaska Katmalite Corporation during the period 1946-1949, but no production has taken place since that time. Pumice deposits found in the Aniakchak-Veniaminof area have probably been derived from three principal sources: Aniakchak Crater, Mt. Veniaminof and Purple Crater. The limited data available indicate the deposits of chief interest occur in the valley of the Aniakchak River and in areas adjacent to Chignik Bay.

  18. Infectious diseases in the Arabian Peninsula and Egypt.

    PubMed

    Shibl, A; Senok, A; Memish, Z

    2012-11-01

    Infectious diseases are important causes of morbidity and mortality globally. Epidemiologically, differences in the patterns of infectious diseases and antimicrobial resistance exist across diverse geographical regions. In this review on infectious diseases in the Arabian Peninsula and Egypt, the epidemiology of tuberculosis, malaria and human immunodeficiency virus (HIV) infections will be addressed. The challenges of the hepatitis C epidemic in Egypt and the epidemiology of this infection across the region will be reviewed. In recent years, we have seen dengue endemicity become established, with major outbreaks in parts of the region. Emerging data also indicate that, across the region, there is an increasing burden of antibiotic resistance, with endemicity in healthcare settings and dissemination into the community. New challenges include the emergence of the Alkhurma haemorrhagic fever virus in Saudi Arabia. The annual Hajj pilgrimage in Saudi Arabia serves as a model for the control of infectious disease in mass gatherings. As most of these countries constantly experience a uniquely dynamic population influx in the form of expatriate workers, tourists, or pilgrims, concerted regional and international collaboration to address these public health concerns in a region that lies at the crossroads for the global spread of infectious pathogens is imperative.

  19. Ozone minihole observation over the Balkan Peninsula in March 2005

    NASA Astrophysics Data System (ADS)

    Werner, R.; Valev, D.; Atanasov, A.; Kostadinov, I.; Petkov, B.; Giovanelli, G.; Stebel, K.; Petritoli, A.; Palazzi, E.

    Areas with dimensions of 1000 km -- 3000 km in which the total ozone content TOC decreases fast are called ozone miniholes They are generated mainly dynamically in two ways either by poor ozone airmass transport from the tropics to higher latitudes by planetary wave activity or they are connected with strong adiabatic uplifting of the tropopause height An ozone minihole generated by the second mechanism was observed over the Balkan Peninsula on 19 21 March 2005 In the middle of March the polar vortex was strongly disturbed by Rossby waves reaching up to the lower stratosphere Warming episodes over a geographical area covering the Barent Sea and the Polar Sea north from Central Siberia displaced a polar vortex fragment extremely southwards However the vorticity was weak and the stratospheric temperatures did not reach low values providing conditions for ozone chemical destruction via heterogenic reactions At the same time a Rossby wave ridge was located below the European polar fragment In the period from 13 to 19 March the thermal tropopause over Sofia was uplifting almost by 3 1 km Ozone distributions observed by the SCIAMACHY instrument on 18-21 March show an fast TOC decrease westwards from Ireland which was moving eastwards during the next days increasing the area in which the ozone content decreased On 20 21 March low ozone content was observed above the Stara Zagora 42 N 25 E ground-based station by means of the GASCOD instrument using DOAS technique The TOMS Earth probe instrument

  20. Simulating the effects of soil organic nitrogen and grazing on arctic tundra vegetation dynamics on the Yamal Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Yu, Q.; Epstein, H. E.; Walker, D. A.

    2009-12-01

    Sustainability of tundra vegetation under changing climate on the Yamal Peninsula, northwestern Siberia, home to the world’s largest area of reindeer husbandry, is of crucial importance to the local native community. An integrated investigation is needed for better understanding of the effects of soils, climate change and grazing on tundra vegetation in the Yamal region. In this study we applied a nutrient-based plant community model (ArcVeg) to evaluate how two factors (soil organic nitrogen [SON] levels and grazing) interact to affect tundra responses to climate warming across a latitudinal climatic gradient on the Yamal Peninsula. Model simulations were driven by field-collected soil data and expected grazing patterns along the Yamal Arctic Transect (YAT), within bioclimate subzones C (High Arctic), D (northern Low Arctic) and E (southern Low Arctic). Plant biomass and NPP (net primary productivity) were significantly increased with warmer bioclimate subzones, greater soil nutrient levels and temporal climate warming, while they declined with higher grazing frequency. Temporal climate warming of 2 °C caused an increase of 665 g/m2 in total biomass at the high SON site in subzone E, while only 298 g/m2 in the low SON site. When grazing frequency was also increased, total biomass increased by only 369 g/m2 in the high SON site in contrast to 184 g/m2 in the low SON site in subzone E. When comparing low grazing to high grazing effects on soil organic nitrogen pools over time (Figure 1), higher grazing frequency led to either slower SON accumulation rates or more rapid SON depletion rates. Warming accentuated these differences caused by grazing, suggesting the interaction between grazing and warming may yield greater differences in SON levels across sites. Our results suggest that low SON and grazing may limit plant response to climate change. Interactions among bioclimate subzones, soils, grazing and warming significantly affect plant biomass and productivity in

  1. Saharan versus local influence on atmospheric aerosol deposition in the southern Iberian Peninsula: Significance for N and P inputs

    NASA Astrophysics Data System (ADS)

    Morales-Baquero, Rafael; Pérez-Martínez, Carmen

    2016-03-01

    A novel methodology was used to evaluate the contribution of Saharan dust to the atmospheric deposition of particulate material (PM), total phosphorus (TP), and total nitrogen (TN) in the southeastern Iberian Peninsula. Dry and wet aerosol depositions were measured weekly during two 1 year periods at one site and simultaneously during spring-summer of the same years at two other sites (intersite distance of ~ 40 km). Statistical relationships among depositions at the different sites permitted differentiation of Saharan dust inputs from locally derived dust. PM and TP depositions were synchronous among the three study sites; the synchrony was elevated during periods of Saharan intrusions (evaluated by air mass retrotrajectories analyses), but no temporal correlation was observed during periods without Saharan intrusions. According to analysis of variance results, PM and TP depositions were both significantly affected by Saharan intrusions. During weeks with Saharan intrusions, PM deposition increased around 85% above background levels, with no differences among the three sites, while TP deposition increased by 1.1 µmol TP m-2 d-1, i.e., 29% to 81% above background levels depending on the site. There were no correlations or differences in TN deposition among sites or as a function of Saharan intrusion periods. The annual contribution of PM and TP from Saharan dust was 75 kg ha-1 and 0.07 kg P ha-1, respectively, which can be considered a genuine input for the ecosystems in this area. This novel approach is likely to be valid in any area in the world under atmospheric deposition of long-range transported material.

  2. Inventory Survey of Geodiversity Elements in a Regional Territory: Applied to the Biga Peninsula, Northwestern Turkey

    NASA Astrophysics Data System (ADS)

    Sedat Çetiner, Ziya; Ertekin, Can; Filiz, Nurdan

    2016-04-01

    Representative geodiversity elements such as minerals, rocks, fossils, landforms, etc are key components in order to obtain data for the pursuit of geo-research. The scientific worth of geodiversity is not only related to how the geosphere works but also is connected with the conservation of earth materials for present and future geo-knowledge and geoscience milieu. Hence, the nonrenewable nature of geodiversity elements in the human time scale is taken into account for the conservation of natural diversity or simply geo-conservation. Geodiversity as an abiotic element ascribes to in situ or ex situ features both of which maintain scientific value and are used by various societies such as in teaching, tourism, etc. Ex situ elements are known as fossils, minerals and rocks found in museum collections on the other hand in situ features are known as geosites for which there are certain sub-categories such as geomorphological (landform), hydrogeological, paleontological, structural, stratigraphic sequence and lithological. Due to the plethora of geological data dispersed among geodiversity elements, the first crucial step is to execute an inventory solid study. The scope of this study is to survey geodiversity features of potential natural sites distributed the entire sectors of the Biga Peninsula of Northwestern Turkey. In the territory, there are 37 natural sites with their own data set. This data describing their boundaries and administrative features were acquired from Directorate General for Preservation of Natural Heritage. Then, site boundaries, regional published geological maps, surface hydrologic and anthropic attributes were overlaid conceiving as a single unit. Before initiating the inventory survey, the criteria scale were established for geoscience value and geo-tourism potential. In these two frames, geodiversity elements were labeled and tabulated by their representativeness, integrity, rarity, scientific knowledge, scenery, interpretative potential and

  3. A palaeoenvironmental reconstruction of c. 2 million year old Oldowan archaeological occurrences on the Homa Peninsula, southwestern Kenya: a multiproxy approach

    NASA Astrophysics Data System (ADS)

    Vincent, Thomas; Whitfield, Elizabeth; Kirby, Jason; Hunt, Christopher; Bishop, Laura; Plummer, Thomas; Ditchfield, Peter

    2016-04-01

    The Homa Peninsula, situated on the Winam Gulf of Lake Victoria, has yielded traces of hominin activity going back to at least ˜2ma BP. The best known site on the peninsula, Kanjera South, boasts large stone artefact and zooarchaeological assemblages preserved in three beds (from oldest to youngest: KS-1 to KS-3). Previous studies have used field sedimentological analyses, as well as stable isotope analysis of pedogenic carbonates to better understand the depositional and environmental contexts of hominin activities. These suggest that sediments were deposited in alluvial and lake marginal environments on a grassy plain, between wooded slopes and a permanent water body. The aim of this study is to refine previous palaeoenvironmental reconstructions of Kanjera South with the aid of particle size analysis, whilst also offering insights into the palaeoenvironment of other archaeological sites on the Homa Peninsula through a multiproxy approach. The project aims to include analyses of particle size, stable-isotopes, pollen and siliceous microfossils (phytoliths, diatoms and sponge spicules). Preliminary results of particle size and phytolith analyses have refined interpretations of the depositional environment at Kanjera South for beds KS1-3. Poor sorting, a bimodal distribution and sand/silty-sand grade material characterise the sediments. The characteristics suggest rapid deposition and/or a variable energy regime. A varying flow regime in relatively unconfined ephemeral channels might explain the transportation and deposition of sediments. Fluvial reworking of aeolian sediments, most likely during unconfined flood events may also have occurred. Phytoliths from the same beds showed grassland indicating Pooideae, as well as some Bambusoideae and woodland indicating phytoliths; this supports previous work.

  4. Evolution of the Antarctic Peninsula lithosphere: Evidence from Mesozoic mafic rocks

    NASA Astrophysics Data System (ADS)

    Riley, T. R.; Curtis, M. L.; Flowerdew, M. J.; Whitehouse, M. J.

    2016-02-01

    New geochronology from a thick (> 800 m) basaltic succession along the eastern margin of the Antarctic Peninsula confirm a Middle Jurassic age (178 ± 1 Ma). This marginally postdates the adjacent Ferrar large igneous province of the Transantarctic Mountains and predates the extensive silicic volcanism of the Mapple Formation (~ 170 Ma) of the Antarctic Peninsula. The geochemistry of other rare, but broadly contemporaneous, basaltic successions of the Antarctic Peninsula, along with Cretaceous-age mafic dykes, are used to interpret the influences of lithospheric and asthenospheric mantle sources during the Mesozoic. Two significant high magmatic addition rate events occurred along the Antarctic Peninsula continental margin at 170 and 110 Ma and can be correlated to events along the South American Cordillera. These 'flare-up' events are characterised by extensive silicic (mostly ignimbrite) volcanism of the Chon Aike Province (V2 event: 170 Ma) and significant granitoid batholith emplacement of the Lassiter Coast intrusive suite (110 Ma). The 170 Ma event is exposed across large parts of the northern Antarctic Peninsula, whilst the 110 Ma event is more widespread across the southern Antarctic Peninsula. The basaltic volcanism described here precedes the 'flare-up' event at 170 Ma and has geochemical characteristics that indicate a thickened lithosphere prevailed. A major dyke swarm that followed the 170 Ma event indicates that extensive lithospheric thinning had occurred, which allowed the ascent of depleted mafic melts. The thinning was the direct result of widespread lower crustal/upper lithospheric melting associated with the silicic volcanism. In the southern Antarctic Peninsula, the lithosphere remained over thickened until the emplacement of the major batholiths of the Lassiter Coast intrusive suite at 110 Ma and was then immediately followed by the emplacement of more asthenosphere-like melts indicating extensive lithospheric thinning.

  5. Population increase in Kirtland's warbler and summer range expansion to Wisconsin and Michigan's Upper Peninsula, USA

    USGS Publications Warehouse

    Probst, J.R.; Donner, D.M.; Bocetti, C.I.; Sjogren, S.

    2003-01-01

    The threatened Kirtland's warbler Dendroica kirtlandii breeds in stands of young jack pine Pinus banksiana growing on well-drained soils in Michigan, USA. We summarize information documenting the range expansion of Kirtland's warbler due to increased habitat management in the core breeding range in the Lower Peninsula of Michigan during 1990?2000. We collected records and conducted searches for the species in Michigan's Upper Peninsula and Wisconsin over 1978?2000. During that time 25 males were found in Wisconsin and 90 males in the Upper Peninsula. We documented colonization of Michigan's Upper Peninsula by six ringed males from the Lower Peninsula of Michigan. Four ringed birds also moved back to the core breeding range, including two males that made two-way movements between the core breeding range and the Upper Peninsula. Thirty-seven females were observed with males from 1995 to 2000, all in Michigan. Nesting activities were noted for 25 pairs and at least nine nests fledged young. One male ringed as a fledgling returned to breed in two subsequent years. After a 19-year period of population stability, the Kirtland's warbler population increased four-fold during 1990?2000, most likely in response to a tripling in habitat area. This increase in sightings and documented breeding may be related to habitat availability in Michigan's Upper Peninsula and to saturation of habitat in the main breeding range. The increase in extra-limital records during 1995?1999 corresponds to the time when the population went from the minimum to the maximum projected population densities, and a decline in natural wildfire habitat was just offset by new managed habitat for the Kirtland's warbler.

  6. Long-term persistence of subduction earthquake segment boundaries: Evidence from Mejillones Peninsula, northern Chile

    NASA Astrophysics Data System (ADS)

    Victor, P.; Sobiesiak, M.; Glodny, J.; Nielsen, S. N.; Oncken, O.

    2011-02-01

    The Mejillones Peninsula in northern Chile has been recognized as the surface expression of a segment boundary for large subduction zone earthquakes. The sharp contact between the rupture planes of two instrumentally recorded earthquakes, the Mw = 8.0 Antofagasta (1995) and the Mw = 7.7 Tocopilla (2007) events, is located beneath the central part of Mejillones Peninsula. We present new chronostratigraphic and structural data that allow reconstructing the evolution of the Peninsula at the surface and correlation of the latter with seismic cycle deformation on the plate interface. Uplift commenced after 3.4 Myr, as recorded in the western highland. The central graben area on the Peninsula started uplifting above sea level as an anticlinal hinge zone prior to 400 kyr ago, most probably 790 kyr ago. The resulting E-W trending hinge exactly overlies the limit between the rupture planes of the Antofagasta and Tocopilla earthquakes. By correlating the uplift data with the slip distribution of the above earthquakes, we demonstrate that deformation and uplift is focused during the postseismic and interseismic periods of the megathrust seismic cycle with coseismic deformation opposed to the long-term motion. Additionally, the slip deficit beneath the Peninsula accumulating between events is probably largely recovered by creep. Hence we suggest that Mejillones Peninsula owes its existence to the lateral variation of the propensity for unstable slip at the interface. Since the latter is a material property, the long-term spatial stability of the Peninsula as a barrier to rupture propagation since at least the middle Pleistocene is a necessary consequence.

  7. Wavefield Inversion of Surface Waves for Delineating Seismic Structure in Saline Permafrost: A Case History from the Barrow Peninsula, AK

    NASA Astrophysics Data System (ADS)

    Dou, S.; Dreger, D. S.; Peterson, J.; Ulrich, C.; Dafflon, B.; Hubbard, S. S.; Ajo Franklin, J. B.

    2014-12-01

    Seismic investigations of permafrost are essential in cold-region applications including static corrections for seismic exploration and site characterization for infrastructure development. Surface-wave methods are advantageous because their applicability does not require regular velocity gradients. But distinct challenges also exist: The irregular velocity variations in permafrost, combined with the marked velocity contrasts between frozen and unfrozen ground, often yield complicated dispersion spectra in which higher-order and leaky modes are dominant. Owing to the difficulties in retrieving dispersion curves from such spectra, dispersion-curved-based inversion methods become inapplicable. Here we present a case study of using wavefield inversion of surface waves to infer the permafrost structure on the Barrow Peninsula of the Alaskan Arctic Coastal Plain. In May of 2014, we conducted an active multichannel surface-wave survey along a 4300-m (2.7-mi) NE-SW trending transect that extended from the coastal to the interior areas of the peninsula. We acquired surface-wave supergathers—each covering a distance of 147 meters—from four nearly equidistantly distributed subsections of the transect. The dispersion spectra show dominant higher-order and leaky modes, as well as inversely dispersive trends (i.e., phase velocities increase with increasing frequencies). Preliminary results reveal a "sandwich" velocity structure, in which a pronounced low-velocity layer (with S-wave velocity reductions up to ~45%-60%; tens of meters thick; overlain by 3-4 m of high-velocity strata) is embedded within high-velocity strata, and the low-velocity layer itself contains irregular velocity gradients. Considering the low ground temperatures of -10 °C to -8 °C, this low-velocity feature is likely to be an embedded saline layer that is only partially frozen due to freezing-point depression of dissolved salts. Because saline permafrost is particularly sensitive to thermal

  8. Assessing methods for developing crop forecasting in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Ines, A. V. M.; Capa Morocho, M. I.; Baethgen, W.; Rodriguez-Fonseca, B.; Han, E.; Ruiz Ramos, M.

    2015-12-01

    Seasonal climate prediction may allow predicting crop yield to reduce the vulnerability of agricultural production to climate variability and its extremes. It has been already demonstrated that seasonal climate predictions at European (or Iberian) scale from ensembles of global coupled climate models have some skill (Palmer et al., 2004). The limited predictability that exhibits the atmosphere in mid-latitudes, and therefore de Iberian Peninsula (PI), can be managed by a probabilistic approach based in terciles. This study presents an application for the IP of two methods for linking tercile-based seasonal climate forecasts with crop models to improve crop predictability. Two methods were evaluated and applied for disaggregating seasonal rainfall forecasts into daily weather realizations: 1) a stochastic weather generator and 2) a forecast tercile resampler. Both methods were evaluated in a case study where the impacts of two seasonal rainfall forecasts (wet and dry forecast for 1998 and 2015 respectively) on rainfed wheat yield and irrigation requirements of maize in IP were analyzed. Simulated wheat yield and irrigation requirements of maize were computed with the crop models CERES-wheat and CERES-maize which are included in Decision Support System for Agrotechnology Transfer (DSSAT v.4.5, Hoogenboom et al., 2010). Simulations were run at several locations in Spain where the crop model was calibrated and validated with independent field data. These methodologies would allow quantifying the benefits and risks of a seasonal climate forecast to potential users as farmers, agroindustry and insurance companies in the IP. Therefore, we would be able to establish early warning systems and to design crop management adaptation strategies that take advantage of favorable conditions or reduce the effect of adverse ones. ReferencesPalmer, T. et al., 2004. Development of a European multimodel ensemble system for seasonal-to-interannual prediction (DEMETER). Bulletin of the

  9. Pesticides in shallow groundwater in the Delmarva Peninsula

    USGS Publications Warehouse

    Koterba, M.T.; Banks, W.S.L.; Shedlock, R.J.

    1993-01-01

    A regional study of the areal and depth distribution of pesticides in shallow groundwater in the Delmarva Peninsula of Delaware, Maryland, and Virginia was done to (i) relate the pesticides detected to landscape and shallow subsurface features, and (ii) evaluate aquifer vulnerability and the potential contamination of drinking-water supplies. Water samples collected at 100 wells from 1988 to 1990 were analyzed for concentrations of 36 pesticides, four metabolites, and other constituents. The most commonly detected residues were atrazine, cyanazine, simazine, alachlor, metolachlor, and dicamba. Concentrations were low; few exceeded 3 ??g L-1. Most detections correlate with the intensive use of these herbicides in three widely distributed and commonly rotated crops-corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and small grain-particularly if grown in well- drained soils. Most detections occurred in samples collected from shallow wells screened within 10 m of the overlying water table. The shallow depth distribution of most residues is consistent with their suspected history of use (ca. 20 yr), and patterns in shallow groundwater flow in the surficial aquifer in the study area. The areal and depth distributions of detectable residues in groundwater did not correlate with a vulnerability index, nor any of the component scores developed to estimate that index using the DRASTIC method. The shallow depth of most detections also indicates why few samples from water-supply wells in this study had measurable concentrations of pesticides; most supply wells are deeper than 10 m below the water table. The low number of contaminated samples from supply wells implies that deep groundwater currently (1992) used for drinking generally does not contain detectable pesticide residues.

  10. Heterogeneous structure of the lithosphere of the Taimyr Peninsula

    NASA Astrophysics Data System (ADS)

    Litvinova, Tamara; Petrova, Alevtina

    2016-04-01

    Magnetic anomalies of the lower crust is well manifested in the satellite measurements and their reductions for the heights H = 100 and 400 km. Currently, however, a great interest is the area of negative magnetic anomalies, allocated to the same heights. They are confined to a special permeable zones of the crust and lithosphere, having increased geothermal activity and are associated with a variety of minerals. In digital magnetic anomalies and gravity anomalies circumpolar map of the Arctic Ocean (Total) was built geomagnetic and density sections along latitudinal and longitudinal cross sections of negative magnetic anomalies (n = 100 km). In the Taimyr Peninsula they capture the largest Fadyukudinsko Kotuiskaya-ring structure. In the north-central Siberia Fadyukudinsko Kotuiskaya ring structure is the "hub" articulation largest geoblocks (Anabar, Kureisko-Tunguska and North Kara). It is manifested in the gravity and magnetic field is also a ring structure. With Fadyukudinsko Kotui-ring structure formation associated injectors and high-carbonate metasomatic rocks tectonites controlling uranium and thorium-uranium-fluorite-barite-rare earth mineralization (VF Proskurnin, et al. 2010). It hypabyssal front of the hot spots. Fadyukudinsko-Kotuiskaya structure is defined posletrappovoe place in the north of the Eurasian plate, responding to a hot spot or a spot lower mantle plumes Triassic [Kravchenko SM, Hain VE 1996 Sazonov AM, Zvyagin EA, Leontiev SI et al., 2010]. Latitude and longitude revealed Profile permeable zones of low magnetic properties and density, confined to a weakened layer in the middle crust. Negative satellite magnetic anomalies (n = 100 km) at depths of 20 - 25-30 km weakly magnetic lens revealed a low density. The upper crust they overlap and dense magnetic rocks. At the bottom of the crust, these lenses are underlain by layers of dense and magnetic structures.

  11. Focal mechanisms of recent earthquakes in the Southern Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Park, Jong-Chan; Kim, Woohan; Chung, Tae Woong; Baag, Chang-Eob; Ree, Jin-Han

    2007-06-01

    We evaluate the stress field in and around the southern Korean Peninsula with focal mechanism solutions, using the data collected from 71 earthquakes (ML = 1.9-5.2) between 1999 and 2004. For this, the hypocentres were relocated and well-constrained fault plane solutions were obtained from the data set of 1270 clear P-wave polarities and 46 SH/P amplitude ratios. The focal mechanism solutions indicate that the prevailing faulting types in South Korea are strike-slip-dominant-oblique-slip faultings with minor reverse-slip component. The maximum principal stresses (σ1) estimated from fault-slip inversion analysis of the focal mechanism solutions show a similar orientation with E-W trend (269° -275°) and low-angle plunge (10° -25°) for all tectonic provinces in South Korea, consistent with the E-W trending maximum horizontal stress (σHmax) of the Amurian microplate reported from in situ stress measurements and earthquake focal mechanisms. The directions of the intermediate (σ2) and minimum (σ3) principal stresses of the Gyeongsang Basin are, however, about 90 deg off from those of the other tectonic provinces on a common σ2-σ3 plane, suggesting a permutation of σ2 and σ3. Our results incorporated with those from the kinematic studies of the Quaternary faults imply that NNW- to NE-striking faults (dextral strike-slip or oblique-slip with a reverse-slip component) are highly likely to generate earthquakes in South Korea.

  12. A high resolution regional paleoclimate experiment over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Gomez-Navarro, J. J.; Montavez, J. P.; Jerez, S.; Jimenez-Guerrero, P.; Garcia-Valero, J. A.; Gonzalez-Rouco, J. F.

    2009-04-01

    During the last years the use of paleoclimate simulations with models of different complexity has become an usual tool in paleoclimate studies. Progress in understanding climate variability leans on simulation and reconstruction efforts. Exercises blending both approaches present a great potential for answering questions relevant for both the simulation and reconstruction of past climate, and depend on the specific peculiarities of proxies and methods involved in climate reconstructions, as well as on the realism and limitations of model simulations. Most of paleoclimate integrations available in the literature covering the last millennium have been performed with relative rough resolution which does not allow to analyze regional climate features that can be of interest in the context of proxies evidence. In this work we present a new high resolution (30 km) regional climate simulation over the Iberian Peninsula of the last five centuries and two extensions to the future for the A2 and B2 SRES scenarios. The regional simulations were performed with a climate version of the MM5 model coupled to the Noah LSM. The driving conditions used follow the Erik1 experiment, performed with the ECHO-G global circulation model. The results indicate that the seasonal modes of variation for near surface air temperature and precipitation obtained within the regional paleoclimate experiment are consistent with the obtained using the observational databases and equivalent to regional climate integrations driven by reanalysis data. On the other hand, the main modes of variation show strong signals in historical periods such as the Maunder and Dalton Minimum. Finally, some preliminary comparisons between the global and the regional model against tree ring temperature reconstructions are also reported in this contribution.

  13. Sand dunes on the central Delmarva Peninsula, Maryland and Delaware

    USGS Publications Warehouse

    Denny, Charles Storrow; Owens, James Patrick

    1979-01-01

    Inconspicuous ancient sand dunes are present in parts of the central Delmarva Peninsula, Maryland and Delaware. Many dunes are roughly V-shaped, built by northwest winds, especially on the east sides of some of the large rivers. On the uplands, the form and spacing of the dunes are variable. A surficial blanket composed mainly of medium and fine-grained sand-the Parsonsburg Sand-forms both the ancient dunes and the broad plains between the dunes. The sand that forms the dunes is massive and intensely burrowed in the upper part; traces of horizontal or slightly inclined bedding appear near the base. Quartz is the dominant mineral constituent of the sand. Microline is abundant in the very fine to fine sand fraction. The heavy-mineral assemblages (high zircon, tourmaline, rutile) are more mature than in most of the possible source rocks. The most abundant minerals in the clay-sized fraction are dioctahedral vermiculite, kaolinite, illite, montmorillonite, and gibbsite. The first four minerals are common in deposits of late Wisconsin and Holocene age. The gibbsite may be detrital, coming from weathered rocks of Tertiary age. The soil profile in the dune sand is weakly to moderately developed. At or near the base of the Parsonsburg Sand are peaty beds that range in age from about 30,000 to about 13,000 radiocarbon years B.P. Microfloral assemblages in the peaty beds suggest that the dunes on the uplands formed in a spruce parkland during the late Wisconsin glacial maximum. The river dunes may also be of late Wisconsin age, but could be Holocene.

  14. Climate change enhances primary production in the western Antarctic Peninsula.

    PubMed

    Moreau, Sébastien; Mostajir, Behzad; Bélanger, Simon; Schloss, Irene R; Vancoppenolle, Martin; Demers, Serge; Ferreyra, Gustavo A

    2015-06-01

    Intense regional warming was observed in the western Antarctic Peninsula (WAP) over the last 50 years. Here, we investigate the impact of climate change on primary production (PP) in this highly productive region. This study is based on temporal data series of ozone thickness (1972-2010), sea ice concentration (1978-2010), sea-surface temperature (1990-2010), incident irradiance (1988-2010) and satellite-derived chlorophyll a concentration (Chl-a, 1997-2010) for the coastal WAP. In addition, we apply a photosynthesis/photoinhibition spectral model to satellite-derived data (1997-2010) to compute PP and examine the separate impacts of environmental forcings. Since 1978, sea ice retreat has been occurring earlier in the season (in March in 1978 and in late October during the 2000s) while the ozone hole is present in early spring (i.e. August to November) since the early 1990s, increasing the intensity of ultraviolet-B radiation (UVBR, 280-320 nm). The WAP waters have also warmed over 1990-2010. The modelled PP rates are in the lower range of previously reported PP rates in the WAP. The annual open water PP in the study area increased from 1997 to 2010 (from 0.73 to 1.03 Tg C yr(-1) ) concomitantly with the increase in the production season length. The coincidence between the earlier sea ice retreat and the presence of the ozone hole increased the exposure to incoming radiation (UVBR, UVAR and PAR) and, thus, increased photoinhibition during austral spring (September to November) in the study area (from 0.014 to 0.025 Tg C yr(-1) ). This increase in photoinhibition was minor compared to the overall increase in PP, however. Climate change hence had an overall positive impact on PP in the WAP waters. PMID:25626857

  15. Field observations on hydrodynamic and coastal geomorphic processes off Harilaid Peninsula (Baltic Sea) in winter and spring 2006 2007

    NASA Astrophysics Data System (ADS)

    Suursaar, Ü.; Jaagus, J.; Kont, A.; Rivis, R.; Tõnisson, H.

    2008-10-01

    Investigations of multi-layer current regime, variations in sea level and wave parameters using a bottom-mounted RDCP ( Recording Doppler Current Profiler) during 20 December 2006-23 May 2007 were integrated with surveys on changes of shorelines and contours of beach ridges at nearby Harilaid Peninsula (Saaremaa Island). A W-storm with a maximum average wind speed of 23 m s -1 occurred on 14-15 January with an accompanying sea level rise of at least 100 cm and a significant wave height of 3.2 m at the 14 m deep RDCP mooring site. It appeared that in practically tideless Estonian coastal waters, Doppler-based "vertical velocity" measurements reflect mainly site-dependent equilibrium between resuspension and sedimentation. The mooring site, 1.5 km off the Kelba Spit of Harilaid, was located in the accumulation zone, where downward fluxes dominated and fine sand settled. As a result of storms in January and April, the distal part of the accumulative gravel spit advanced by 50 m, whereas a 30-50 m retreat of the shoreline in the western and northern parts occurred at Cape Kiipsaare. The location of the beach ridges shows that the development of the spit occurs through relatively short-period but infrequent storm events, roughly 2-3 times each decade.

  16. Impact of the variability of the seasonal snow cover on the ground surface regimes in Hurd Peninsula (Livingston Island, Antarctic)

    NASA Astrophysics Data System (ADS)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2014-05-01

    Seasonally snow cover has a great impact on the thermal regime of the active layer and permafrost. Ground temperatures over a year are strongly affected by the timing, duration, thickness, structure and physical and thermal properties of snow cover. The purpose of this communication is to characterize the shallow ground thermal regimes, with special reference to the understanding of the influence snow cover in permafrost spatial distribution, in the ice-free areas of the north western part of Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". We have analyzed and ground temperatures as well as snow thickness data in four sites distributed along an altitudinal transect in Hurd Peninsula from 2007 to 2013: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). At each study site, data loggers were installed for the monitoring of air temperatures (at 1.5 m high), ground temperatures (5, 20 and 40 cm depth) and for snow depth (2, 5, 10, 20, 40, 80 and 160 cm) at 4-hour intervals. The winter data suggests the existence of three types of seasonal stages regarding the ground surface thermal regime and the thickness of snow cover: (a) shallow snow cover with intense ground temperatures oscillations; (b) thick snow cover and low variations of soil temperatures; and (c) stability of ground temperatures. Ground thermal conditions are also conditioned by a strong variability. Winter data indicates that Nuevo Incinerador site experiences more often thicker snow cover with higher ground temperatures and absence of ground temperatures oscillations. Collado Ramos and Ohridski show frequent variations of snow cover thickness, alternating between shallow snow cover with high ground temperature fluctuation and thick snow cover and low ground temperature fluctuation. Reina Sofia in all the years has thick snow cover with little variations in soil

  17. Last Neanderthals and first Anatomically Modern Humans in the NW Iberian Peninsula: Climatic and environmental conditions inferred from the Cova Eirós small-vertebrate assemblage during MIS 3

    NASA Astrophysics Data System (ADS)

    Rey-Rodríguez, Iván; López-García, Juan-Manuel; Bennàsar, Maria; Bañuls-Cardona, Sandra; Blain, Hugues-Alexandre; Blanco-Lapaz, Ángel; Rodríguez-Álvarez, Xosé-Pedro; de Lombera-Hermida, Arturo; Díaz-Rodríguez, Mikel; Ameijenda-Iglesias, Alicia; Agustí, Jordi; Fábregas-Valcarce, Ramón

    2016-11-01

    Cova Eirós is emerging as a reference site in the northwestern Iberian Peninsula for the study of the development of the last Neanderthal populations and the first populations of Anatomically Modern Humans (AMH) in MIS 3. Cova Eirós is an archaeological site (with Middle and Upper Palaeolithic levels) located in Cancelo, Triacastela (Lugo, northwestern Iberian Peninsula), which has been systematically excavated from 2008 onwards. The small-vertebrate assemblage analysed came from the archaeo-palaeontological field seasons that took place from 2009 to 2014. At least 18 small-vertebrate taxa have been identified: 1 frog (Rana temporaria), 1 snake (Vipera sp.), 4 insectivores (Sorex minutus, Sorex sp., Talpa cf. occidentalis and Erinaceus europaeus), 4 chiropters (Myotis myotis/blythii, cf. Miniopterus sp., Myotis sp. and Rhinolophus ferrumequinum) and 8 rodents (Apodemus sylvaticus, Arvicola amphibius, Arvicola sapidus, Chionomys nivalis, Microtus (Terricola) lusitanicus, Microtus agrestis, Microtus arvalis and Microtus oeconomus). Using the Habitat Weighting method to reconstruct the palaeoenvironment, we reconstruct a landscape for MIS 3 characterized by open woodland formations. The Mutual Ecogeographic Range (MER) method and the Bioclimatic Model (BM) used for the palaeoclimatic reconstruction show lower temperatures and higher precipitation than at present in the region. Our results from Cova Eirós are compared with the data obtained from several other sites in the Iberian Peninsula; it can be said that Neanderthals and AMH were well adapted to the territory that they occupied, as well as to the surrounding environment and the climatic conditions prevalent in the unstable context of MIS 3 in the Iberian Peninsula.

  18. Solar vs. Tidal Forcing of Centennial to Decadal Scale Variability in Marine Sedimentary Records from the Western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Kirkwood, G.; Domack, E.; Brachfeld, S.

    2004-12-01

    Prior studies on Holocene marine sediments from the Antarctic Peninsula, including ODP Site 1098 and USAP N. B. Palmer jumbo piston cores have revealed pronounced multi-century scale variations within a number of paleoenvironmental proxies. In order to fully understand the exact timing of this signal an ultra-high resolution jumbo piston core from the Schollaert Drift was correlated with the well-known Palmer Deep record. A precise and accurate radiocarbon chronology is now available from the former site that utilizes in-situ mollusks, rather than bulk organic matter. The resulting time series spans the last 5000 years over the 20 m length of core NBP99-03 JPC28 and the surface stratigraphy of kasten core NBP01-07 KC8. The corrected and calibrated ages (with an applied reservoir correction of 1170 years) of 10 mollusks dated by the National Ocean Sciences Accelerator Mass Spectrometry Facility and the University of Arizona TAMS facility were used to construct an age-depth profile for JPC28 and KC8. A linear trend (R2 value of 0.993) of the age-depth profile was used to extrapolate the constant time interval between magnetic susceptibility measurements, which were analyzed every 1 cm. Dominant periods in the upper 10 m of the time series were identified using the Arand Spectral Analysis Package (Howell, 2001). This analysis revealed a single pronounced maxima at 160 years, which is inconsistent with the dominant periods found in time series of climate proxies from other sites on the western side of the Antarctic Peninsula. In particular, periods of 200 and 400 years, which are dominant in the Palmer Deep site (Warner and Domack, 2002), are not present in the Schollaert Drift. The spectral peaks derived from the two records are significantly different at the 95% confidence level. The cycles in the Palmer Deep record have been associated with solar variability, where as the 160 year cycle in the Schollaert Drift is close to a 180 year cycle in tidal forces (Keeling

  19. Relative diffusion and dispersion at the Antarctic Peninsula: observations of pairs and triplets of drifters

    NASA Astrophysics Data System (ADS)

    Bandet, Marion D.; Thompson, Andrew F.; Heywood, Karen J.; Thorpe, Sally E.

    2010-05-01

    Forty surface drifters were deployed in 2007 at the tip of the Antarctic Peninsula as part of the ADELIE research project to map the near surface currents around the tip of the Antarctic Peninsula and to determine the role of these currents in the retention or dispersion of krill. Here we use the ADELIE drifters, together with 55 historical drifters that pass close to the Antarctic Peninsula, to evaluate the strength of advection and diffusion in this region. Relative eddy dispersion and diffusivities have been calculated using drifter pairs and triplets. The relative eddy diffusivity along and across isobaths is presented for various areas around the peninsula based on current paths and data availability. Combined together, the ADELIE and historical drifters provide a data set of up to 148 pairs for which we use a maximum initial separation varying between 15 and 60 km and a temporal resolution of 30 days. The triplets, although limited in number, allow the anisotropy of the diffusivity to be quantified. They provide insight into the stretching and straining deformations of krill or tracer patches. The results are compared with a previous analysis of the same data set using single drifters (Thompson et al. 2009, J. Phys. Oceanogr.). Data from ARGO floats deployed in the region will also be used to bring additional information about the flow structure in the vicinity of the Antarctic Peninsula.

  20. Receiver Function Analysis using Ocean-bottom Seismometer Records around the Kii Peninsula, Southwestern Japan

    NASA Astrophysics Data System (ADS)

    Akuhara, T.; Mochizuki, K.

    2014-12-01

    Recent progress on receiver function (RF) analysis has provided us with new insight about the subsurface structure. The method is now gradually being more applied to records of ocean-bottom seismometers (OBSs). In the present study, we conducted RF analysis using OBS records at 32 observation sites around the Kii Peninsula, southwestern Japan, from 2003 to 2007 (Mochizuki et al., 2010, GRL). We addressed problems concerning water reverberations. We first checked the effects of water reverberations on the OBS vertical component records by calculating vertical P-wave RFs (Langston and Hammer, 2001, BSSA), where the OBS vertical component records were deconvolved by stacked traces of on-land records as source functions. The resultant RFs showed strong peaks corresponding to the water reverberations. Referring to these RFs, we constructed inverse filters to remove the effects of water reverberations from the vertical component records, which were assumed to be represented by two parameters, a two-way travel time within the water layer, and a reflection coefficient at the seafloor. We then calculated radial RFs using the filtered, reverberation-free, vertical component records of OBS data as source functions. The resultant RFs showed that some phases at later times became clearer than those obtained by an ordinary method. From the comparison with a previous tomography model (Akuhara et al., 2013, GRL), we identified phases originating from the oceanic Moho, which delineates the relationship between the depth of earthquakes and the oceanic Moho: seaward intraslab seismicity is high within the oceanic crust while the landward seismicity is high within the oceanic mantle. This character may be relevant to the dehydration process.

  1. Magnetostratigraphic Dating of Paleogene Sediments in the Seymour Island (Antarctic Peninsula): A Preliminary Chronostratigraphy

    NASA Astrophysics Data System (ADS)

    Beamud, E.; Montes, M. J.; Santillana, S.; Nozal, F.; Marenssi, S.

    2015-12-01

    Seymour Island is located at 64 º S, close to the northeastern tip of the Antarctic Peninsula. This glacier-free island contains the southernmost exposures of the K/Pg boundary and it has the most complete record of the Paleogene in Antarctica. The base of the Paleogene is represented by the Early Paleocene shallow marine shelf deposits of the Marambio Group; which are unconformably overlain by the Late Paleocene to Late Eocene Seymour Island Group. The Marambio Group is divided into the quartz-rich silty sandstones and mudstones of the López de Bertodano Fm and the mudstones to quartz-rich sandstones of the Sobral Fm. The overlaying Seymour Island Group records the erosion and filling of incised valleys. This group is made up by the Cross Valley-Wiman, La Meseta and the uppermost new Submeseta Formations. Main regressive periods are evidenced by the erosional unconformities and their related time gaps at the base of these three Formations. The La Meseta and Submeseta Formations are composed by poorly consolidated marine sandstones and siltstones deposited in a shallow coastal (possibly estuarine) environment. Several biostratigraphic and isotopic studies have been conducted in the Seymour Island due to its extremely rich fossil record, and the age of the López de Bertodano Fm has been recently refined by magnetostratigraphy. However, the overlying Paleogene formations lack a reliable absolute continuous dating. To solve this problem, a composite magnetostratigraphic section spanning more than 1300 m from the K/Pg boundary up to the top of the Submeseta Fm was conducted, with an average sampling resolution of 3 m per site. Although many samples yielded weak results, a local magnetostratigraphy was obtained which has been correlated to the GPTS. The new derived ages range from Danian (~ 66 Ma) up to Priabonian (~ 34 Ma). These results have been integrated with previous litho-, bio- and isotopic data to build a new Paleogene chronostratigraphy for the Seymour

  2. An 8700 Year Record of Holocene Climate Variability from the Yucatan Peninsula

    NASA Astrophysics Data System (ADS)

    Wahl, D.; Byrne, R.; Anderson, L.

    2013-12-01

    Our understanding of Holocene climate change in the Maya lowlands of Central America has improved significantly during the last several decades thanks to the development of proxy climate records from lake cores and speleothems. One important finding is that longer-term climate changes (i.e., millennial scale) were driven primarily by precessional forcing; less clear, however, are the causes of abrupt shifts and higher frequency (centennial to decadal) change recognized in many Holocene climate reconstructions. The mechanisms driving climate change on these time scales have been difficult to identify in the region, in part because the Yucatan peninsula is influenced by climatic conditions linked to both the tropical Atlantic and Pacific oceans. Additional complications arise from the development of dense human populations following the initial introduction of agriculture ~5000 cal yr BP, which had significant impact on the environment as a whole. Here we present the results of analyses (stable isotope, pollen, magnetic susceptibility, and physical properties) of a 7.25 m sediment core from Lago Puerto Arturo, a closed basin lake in the northern Peten, Guatemala. An age-depth model, based on 6 AMS radiocarbon determinations and created using CLAM, indicates the record extends to 8700 cal yr BP. Proxy data suggest that, similar to other low latitude sites, millennial scale climate at Lago Puerto Arturo was driven by changes in insolation. Higher frequency variability is associated with El Niño/Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) dynamics, reflecting latitudinal shifts in the Intertropical Convergence Zone in both the tropical North Atlantic and North Pacific. Solar forcing may also play a role in short-term climate change. The pollen and isotope records show that the entire period of prehispanic settlement and agricultural activity, i.e. ~5000-1000 cal yr B.P., was characterized by relatively dry conditions compared to before or after.

  3. Mosquitoes associated with ditch-plugged and control tidal salt marshes on the Delmarva Peninsula.

    PubMed

    Leisnham, Paul T; Sandoval-Mohapatra, Sarah

    2011-08-01

    A study was conducted during the summer of 2009 (from July to September) to characterize mosquito communities among different habitats in five historically ditched tidal salt marshes and three adjacent wooded areas in the E.A. Vaughn Wetland Management Area on the Maryland Delmarva Peninsula, USA. Study marshes are characteristic of Atlantic coastal salt marshes that had undergone grid ditching from the 1930s to 1950s. In the autumn of 2008 (October and November) ditches were plugged near their outlets in two ('experimental') marshes with the aim to restore their natural tidal hydrology. The three other marshes were not plugged. Marshes were sampled from July to September in 2009 by using standard dip count method. A total of 2,457 mosquito larvae representing six species were collected on 15.4% (86/557) of all sample occasions and 399 adults representing four mosquito species were collected from landing counts. Aedes sollicitans, Anopheles bradleyi and Culex salinarius were the most common species collected in larval habitats, and Ae. sollicitans was the most common adult collected. Wooded habitats had more total mosquitoes, were also more frequently occupied by mosquitoes and had higher densities of mosquitoes than marsh habitats. Almost all larvae collected from marshes were from one experimental and one control site. The majority of larvae at the control site were Ae. sollicitans in marsh pannes while Cx. salinarius, An. bradleyi, Ae. cantator, and Ae. sollicitans were collected in high numbers from ditches at the experimental site. We found a difference in the proportion of marsh pannes occupied by Ae. sollicitans but not total mosquitoes sampled 4-5 days after spring tide events than on other occasions. Salinity measures of 42 larval habitats showed lower median salinity in mosquito-occupied habitats (11.5 ppt) than unoccupied habitats (20.1 ppt), and in habitats in wooded areas followed by ditches and pannes in marsh areas. The results of this study suggest

  4. Mosquitoes Associated with Ditch-Plugged and Control Tidal Salt Marshes on the Delmarva Peninsula

    PubMed Central

    Leisnham, Paul T.; Sandoval-Mohapatra, Sarah

    2011-01-01

    A study was conducted during the summer of 2009 (from July to September) to characterize mosquito communities among different habitats in five historically ditched tidal salt marshes and three adjacent wooded areas in the E.A. Vaughn Wetland Management Area on the Maryland Delmarva Peninsula, USA. Study marshes are characteristic of Atlantic coastal salt marshes that had undergone grid ditching from the 1930s to 1950s. In the autumn of 2008 (October and November) ditches were plugged near their outlets in two (‘experimental’) marshes with the aim to restore their natural tidal hydrology. The three other marshes were not plugged. Marshes were sampled from July to September in 2009 by using standard dip count method. A total of 2,457 mosquito larvae representing six species were collected on 15.4% (86/557) of all sample occasions and 399 adults representing four mosquito species were collected from landing counts. Aedes sollicitans, Anopheles bradleyi and Culex salinarius were the most common species collected in larval habitats, and Ae. sollicitans was the most common adult collected. Wooded habitats had more total mosquitoes, were also more frequently occupied by mosquitoes and had higher densities of mosquitoes than marsh habitats. Almost all larvae collected from marshes were from one experimental and one control site. The majority of larvae at the control site were Ae. sollicitans in marsh pannes while Cx. salinarius, An. bradleyi, Ae. cantator, and Ae. sollicitans were collected in high numbers from ditches at the experimental site. We found a difference in the proportion of marsh pannes occupied by Ae. sollicitans but not total mosquitoes sampled 4–5 days after spring tide events than on other occasions. Salinity measures of 42 larval habitats showed lower median salinity in mosquito-occupied habitats (11.5 ppt) than unoccupied habitats (20.1 ppt), and in habitats in wooded areas followed by ditches and pannes in marsh areas. The results of this study

  5. Spatial extension of the reconstruction of 1874 Santa Tecla's flash floods in Catalonia (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Lluís Ruiz-Bellet, Josep; Carles Balasch, Josep; Tuset, Jordi; Barriendos, Mariano; Mazón, Jordi; Pino, David

    2014-05-01

    In September 23 1874, a sudden and severe rainstorm caused multiple flash floods in many small catchments (up to 200 km2) in the Southern half of Catalonia (NE Iberian Peninsula). These floods resulted in 575 fatalities and in a huge destruction of dwellings, roads, bridges, canals and crops and, thus, rank among the heaviest events in Catalonia since 1500. The damages were so great that the economic effects of the floods lasted several years. Many flood mark plaques scattered across the affected area remember the date and keep a record of the maximum height reached by the water. This information enables the hydraulic calculation of the peak flow of the flood at the site of the flood mark; so far, this reconstructed peak flow has been calculated in seven sites: Mont-roig and Agramunt on the Sió River, Cervera and Tàrrega on the Ondara River, Vallfogona, Ciutadilla and Guimerà on the Corb River. Moreover, it has been possible to estimate the rainfall from the reconstructed hydrographs. The results agree with the destructive force of the floods: a specific flow of 10 m3•s-1•km-2 in Cervera, an approximate return period of 250 years in Tàrrega, and 150 mm of rain in nine hours in the Ondara catchment, for example. There are many other flood marks that have not been used yet: Granyena on the Vallmajor River, Arbeca on the Turull Torrent, Espluga and Montblanc on the Francolí River, and Vendrell on the Bisbal Torrent. The reconstructed peak flows and rainfalls in these sites will give more insight into the big picture, that is, the temporal and spatial distribution of the meteorological and hydrological factors that produced the fatal event. Our final objective is to compare this regional picture with the even bigger one obtained from the analysis of the synoptic meteorological situation in the days immediately prior to the floods. A secondary objective is to compare this flood with a more recent one, such as the one occurred in September 1962 near Barcelona

  6. Radioactive impact of Fukushima accident on the Iberian Peninsula: evolution and plume previous pathway.

    PubMed

    Lozano, R L; Hernández-Ceballos, M A; Adame, J A; Casas-Ruíz, M; Sorribas, M; San Miguel, E G; Bolívar, J P

    2011-10-01

    High activity concentrations of several man-made radionuclides (such as (131)I, (132)I, (132)Te, (134)Cs and (137)Cs) have been detected along the Iberian Peninsula from March 28th to April 7th 2011. The analysis of back-trajectories of air masses allowed us to demonstrate that the levels of manmade radionuclide activity concentrations in the southwest of the Iberian Peninsula come from the accident produced in the nuclear power plant of Fukushima. The pathway followed by the radioactive plume from Fukushima into Huelva (southwest of the Iberian Peninsula) was deduced through back-trajectories analysis, and this fact was also verified by the activity concentrations measured of those radionuclides reported in places crossed by this radioactive cloud. In fact, activity concentrations reported by E.P.A., and by IAEA, in several places of Japan, Pacific Ocean and United States of America are according to the expected ones from the air mass trajectory arriving at Huelva province.

  7. Spatial climate dynamics in the Iberian Peninsula since 15 000 yr BP

    NASA Astrophysics Data System (ADS)

    Tarroso, Pedro; Carrión, José; Dorado-Valiño, Miriam; Queiroz, Paula; Santos, Luisa; Valdeolmillos-Rodríguez, Ana; Célio Alves, Paulo; Brito, José Carlos; Cheddadi, Rachid

    2016-05-01

    Climate changes in the Iberian Peninsula since the Last Glacial Maximum are associated with distributional shifts of major Mediterranean and European temperate species. The dynamic relationship between climate and species in the past may be retrieved from the fossil records available in the Iberian Peninsula. We have used an extensive set of pollen records to reconstruct spatial layers (1 kyr interval) of January minimum temperature, July maximum temperature, and annual precipitation over the time period between 15 and 3 ka. A functional principal component analysis was used to summarise the spatial evolution of climate in areas that share similar climate trends. When compared between them, the identified four areas show different climate trends over the studied period and are coherent with the existence of multiple refugial areas within the Iberian Peninsula.

  8. Distribution of the sibling species of Anopheles farauti in the Cape York Peninsula, northern Queensland, Australia.

    PubMed

    Sweeney, A W; Cooper, R D; Frances, S P

    1990-09-01

    The sibling species of Anopheles farauti s.l. were collected in larval and adult surveys from 34 localities on Cape York Peninsula and were identified by isoenzyme electrophoresis. The most common species near the coast was An. farauti 1 which was often found breeding within 100 m of the sea in either brackish or freshwater habitats. Larvae of the other 2 species were not found in brackish water which accords with previous laboratory observations of their lower salinity tolerance. Anopheles farauti 2 appears to have the widest distribution of the 3 sibling species on Cape York Peninsula as it was common in both coastal and inland localities. Anopheles farauti 3 was rarely found near the coast. In one locality at Lockhart River near the east coast of the peninsula larvae of the 3 species were found together in a small muddy creek. PMID:2230771

  9. Improving simulation of El Niño Impacts on summer cropping systems of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Capa-Morocho, Mirian; Ruiz-Ramos, Margarita; Rodríguez-Fonseca, Belén

    2013-04-01

    El Niño event is a main driver of seasonal climate variability that greatly impacts agriculture and regional economies (Legler et al., 1999). The relationships found between El Niño and yield can be helpful to anticipate yield anomalies (higher or lower than usual) what can help us to adapt crop systems in advance: insurance coverage, changes in sowing dates, choice of species and varieties, as well as changes in the management of fertilization and irrigation and the establishment of an early warning system. In a previous work, we found that the ENSO affects maize yield differently depending on the location in the Iberian Peninsula (Capa et al., 2012), using observed data series for periods ranging from 22 to 46 years. The specific objective of this work is 1) to confirm these results using a longer time series from re-analysis data; 2) to evaluate the yield simulations done with re-analysis regarding observed crops yields and simulations obtained with observed climate data; and 3) to use re-analysis climate data to help to explain the mechanism of the influence of El Niño. Crop yield was simulated with the ecophysiological crop model CERES-maize, included in DSSAT v.4.5 (Decision Support System for Agrotechnology Transfer). To simulate maize yields, re-analysis daily data of radiation, maximum and minimum temperature and precipitation were used. The re-analysis climate data were obtained from NCEP/NCAR 40-year reanalysis project (NOAA National Center for Environmental Prediction) and ECMWF Data server (European Centre for Medium-Range Weather Forecasts: ERA 40 and ERA Interim). Simulations were made on three locations where site- specific calibrations were done and validated with independent field data: Lugo (northwestern), Getafe (centre) and Albacete (southeastern Spain). Re-analysis data confirm the preliminary results obtained with observed data (AEMET): El Niño phenomenon affects irrigated maize depending on the location in the Iberian Peninsula. Also

  10. Recent observed climate change over the Arabian Peninsula

    NASA Astrophysics Data System (ADS)

    Alsarmi, Said; Washington, Richard

    2011-06-01

    We have examined trends in temperature and precipitation parameters for the Arabian Peninsula (AP) during the last 2 to 3 decades. The data set has been carefully quality controlled and checked for homogeneity. Although of low density (21 stations) and relatively short time period, a clear picture of climate change in the region has emerged. The general pattern of the AP mean annual temperature trend is one of warming, with 14 of 21 stations show statistically significant warming at 0.05 level and most at 0.001 level and only one (Seeb) showing statistically significant cooling. The highest statistically significant mean annual warming trends are found in Oman (Sur = 1.03°C decade-1) and Emirates (Dubai = 0.81°C decade-1). The season of maximum warming in mean temperature is March to April. The highest monthly mean temperature trend in the AP occurs in Sur in May (1.47°C decade-1). There is a broad statistically significant increase in mean annual maximum temperature in AP in 12 out of 21 stations, with the highest trends in central and eastern/southeastern AP. Only SW AP and the Gulf of Oman do not show warming. The highest monthly maximum temperature trend in the AP occurs in Bahrain in March (2.27°C decade-1). The second highest significant warming trends are reported in Doha in February (1.54°C decade-1). For minimum temperature, 16 out of 21 stations show statistically significant warming trends, with the highest annual trends observed in the Emirates (Dubai = 1.24°C decade-1), northwest Oman (Sohar = 1.17°C decade-1) and Qatar (Doha = 1.13°C decade-1). The highest monthly minimum temperature warming rate occurred in October. Both Dubai and Kuwait reported the highest significant rate of 2.00°C decade-1. The general mean annual diurnal temperature range trend is negative in the AP, with six out of 21 stations show statistically significant negative trends while three stations show statistically significant positive trends. Trends in mean annual

  11. Kamchatka Peninsula, Russia 3-D Perspective with Landsat Overlay

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This three-dimensional perspective view, looking up the Tigil River, shows the western side of the volcanically active Kamchatka Peninsula, Russia. The image shows that the Tigil River has eroded down from a higher and differing landscape and now flows through, rather than around the large green-colored bedrock ridge in the foreground. The older surface was likely composed of volcanic ash and debris from eruptions of nearby volcanoes. The green tones indicate that denser vegetation grows on south facing sunlit slopes at the northern latitudes. High resolution SRTM elevation data will be used by geologists to study how rivers shape the landscape, and by ecologists to study the influence of topography on ecosystems.

    This image shows how data collected by the Shuttle Radar Topography Mission (SRTM) can be used to enhance other satellite images. Color and natural shading are provided by a Landsat 7 image acquired on January 31, 2000. Terrain perspective and shading were derived from SRTM elevation data acquired on February 12, 2000. Topography is exaggerated by about six times vertically. The United States Geological Survey's Earth Resources Observations Systems (EROS) DataCenter, Sioux Falls, South Dakota, provided the Landsat data.

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

  12. Dynamics of the Iberian Peninsula Coastal Low-Level Jet

    NASA Astrophysics Data System (ADS)

    Semedo, Alvaro; Rijo, Nádia; Miranda, Pedro; Lima, Daniela C. A.; Cardoso, Rita; Soares, Pedro

    2016-04-01

    Coastal low-level jets (CLLJ) are important mesoscale phenomena of some regional coastal climates. They are characterized by a coast-parallel flow which has a wind speed maxima within the first few hundred meters above sea level (usually below 1000 m, and most of the times around 500 m), encapsulated within the marine atmospheric boundary layer (MABL). Coastal jets have a larger scale synoptic forcing behind them: a high pressure system over the ocean and a thermal low inland. The regions where CLLJ occur coincide with cold equator-ward eastern boundary currents in the mid-latitudes (with an exception of the coast of Oman in the Arabian Sea), where the contrast between the cold ocean and the warm land in the summer is highest. As a response of CLLJ occurrences a positive feedback mechanism is triggered: the coast-parallel wind induces upwelling currents at the coast, reducing the sea surface temperature, which in turn increase the thermal (pressure) gradient at the coast, leading to higher wind speeds. The Iberian Peninsula Coastal Jet (IPCJ) is an example of a CLLJ, developed mostly during the summer season due to the effect of the semi-present Azores high-pressure system in the North Atlantic and of a thermal low pressure system inland. This synoptic pattern drives a seasonal (western) coast parallel wind, often called the Nortada (northerly wind), where the IPCJ develops. A detailed analysis of the IPCJ structure and dynamics will be presented, trough the analysis of two case studies off the west coast of Portugal. The case studies are simulated using the WRF mesoscale model, at 9 and 3 km horizontal resolution, forced by the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis. The MABL structure off the west coast of Iberia, the interaction of the flow with the two main west Iberia capes (Finisterre and Roca), and the consequences on the cloud cover and wind speed up- and down-wind of the capes will be analysed.

  13. The Nature of the Moho Beneath the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Carbonell, R.; Díaz, J.; Brown, D.; Palomeras, I.; Ayarza, P.; Afonso, J. C.; Simancas, F.; Pérez-Estaún, A.; Gallart, J.

    2009-04-01

    The Mohorovičić discontinuity (Moho) was defined by Andrija Mohorovičić in 1910 on the basis of an interpretation of regional earthquake records in Eastern Europe as a relatively abrupt increase in P-wave seismic velocities. The Moho is observed/detected world wide. It is the most important boundary within the Earth's lithosphere. The high resolution subsurface geophysical images have demonstrated that the crust-mantle boundary is a far more complex structure that the initial seismological definition established. The purpose of this contribution is to bring together some of the findings related to the crust-mantle transition beneath the Iberian peninsula and to synthesize these results into a perspective that has global implications. For the last three decades an extensive acquisition of varieties of geophysical and geological data has been carried out. These data include controlled-source seismic (refraction and reflection), natural source seismic, and regional geology. In NW Iberia an analog of the continental crust-mantle transition is exposed within the Paleozoic Cabo Ortegal Complex and can be used for comparison and model building. This provides a unique view into the nature of the crust-mantle transition. From the multi-seismic data the character of the Moho is highly variable, in some areas there are no reflections visible in the normal incidence (e.g. ESCI-BETICS-1), in others reflections are prominent single events (e.g. IBERSEIS) and in still others complex geometric features are observed (ESCI-NORTE). There are also time (depth) differences between the wide-angle and the normal incidence seismic Moho's. Laboratory measurements of P- and S-wave velocities reflect an overall increase from middle to lower crustal velocities in the felsic gneisses and intermediate-to-mafic granulites to mantle velocities in the eclogites and ultramafic rocks. The surface outcrops of Cabo Ortegal complex suggests that the seismic Moho is reached at the contact between

  14. Springtime ice motion in the western Antarctic Peninsula region

    NASA Astrophysics Data System (ADS)

    Geiger, Cathleen A.; Perovich, Donald K.

    2008-02-01

    Oscillatory motion of sea-ice is examined using two ice-drifting buoys separated by 1° latitude near 66°S during the winter to spring transition in the Marguerite Bay region west of the Antarctic Peninsula. The buoys' motions exhibit spectrally distinct periods (12.87±0.04 and 13.03±0.04 h, respectively) despite highly correlated motion between them ( r2 is 0.62 and 0.81 for u and v, respectively). The periods shift with latitude and nearly match the local inertial periods (13.00 and 13.10 h, respectively). The oscillations are further examined with respect to the kinematics involved in the breakup process of sea-ice. These include hourly resolved manifestations of circular trajectories, semi-circular oscillations with compressed trajectory cusps, and "accordion-like" compressions along straight-line trajectories. Oscillations are found in all trajectory types over the lifetime of both buoys (several months). Traditional circular and semi-circular oscillations are particularly prominent during two episodes, one of which is preceded by strong wind events and a substantial decrease in ice thickness and concentration. These episodes combine with seasonally warming temperatures to break up and melt the sea-ice cover. We discuss potential relationships between the degradation of the ice pack during spring breakup and the increase in energy at near-inertial frequencies including the appearance of a non-linear cascade of energy within the ice from the low frequencies (commensurate with storms and fortnightly tides) to semi-diurnal frequencies. We further comment on the implications this type of high-frequency motion has on local biological ecosystems. Specifically, we find that sea-ice semi-diurnal oscillations are at their peak during the final decay of sea-ice just before springtime primary productivity begins. Hence, the oscillatory motion of sea-ice not only serves as an effective mixing agent within the ice-ocean mixed layer, but also serves as an effective

  15. Assessment of the Climate Vulnerabilities of the Arabian Peninsula

    NASA Astrophysics Data System (ADS)

    Alharbi, T.; Sultan, M.; Ahmed, M.; Chouinard, K.

    2014-12-01

    The Arabian Peninsula (AP), like many places around the world, is apparently witnessing the impacts (amount, patterns, and frequency of precipitation) of global warming. Precipitation over the AP is largely controlled by two main wind regimes, the winter (October to March) northerlies or northwesterlies, hereafter referred to as westerlies, and the summer (April to September) monsoonal wind regimes. The global monthly Climate Prediction Centers (CPC) Merged Analysis of Precipitation (CMAP) data (spatial resolution: 2.5° × 2.5°; temporal resolution: monthly; operational period: January 1979 to November 2011) was used to investigate the nature and magnitude of precipitation variations over the AP throughout 1979 - 2010. Trends in CMAP-derived precipitation patterns were examined over the winter and summer seasons throughout Periods I (1979-1995) and II (1996-2010). Reversals in precipitation patterns were observed in Periods I and II, where areas witnessing an increase in precipitation in Period I showed a decrease in precipitation throughout Period II, and vice versa for the remaining areas. Our findings suggest: (1) an increase in precipitation during Period I over the southeastern and southwestern coastal areas of AP (e.g., Muscat, Sanaa, and Jeddah) that is probably related to the intensification of the monsoons at the expense of the westerlies, (2) an increase in precipitation during Period II over the northwestern and southeastern of AP (e.g., northwestern Saudi Arabia, Empty Quarter, western and southwestern Oman, and eastern Yemen) is here attributed to intensification of the westerlies, and 3) the general similarity of annual trend patterns to the summer trend (Period I) and to winter trend (Period II) suggest that the annual trends are largely controlled by monsoonal wind regimes in Period I and by the westerlies in Period II. Outputs (i.e., precipitation) of climatic models (CCSM4.0) over the AP are being extracted (for upcoming 100 years) , downscaled

  16. Neotectonics and fluvial geomorphology of the Northern Sinai Peninsula

    NASA Astrophysics Data System (ADS)

    Kusky, T.; El-Baz, F.

    2000-08-01

    Large anticlinal ridges of Jurassic-Tertiary limestone in the northern Sinai Peninsula are part of the Syrian Arc Fold Belt, parts of which have been active intermittently from Late Cretaceous through the present. Recent uplift of the Syrian Arc Fold Belt is supported by quantitative indices of active tectonics including low values of mountain front sinuosity and, by recent seismicity, extending southwest past Cairo into the Fayoum Depression. The northern Sinai Desert has a climate similar to that of the adjacent part of the eastern Sahara. Sand sheets and dune fields cover its northwestern part, which is a depression extending from the Suez Canal to Wadi El-Arish. Numerous dry channels of palaeorivers and streams lead into this depression, where several temporary palaeolakes and flood overbank deposits have been identified. Some of the temporary pluvial palaeolakes developed behind natural dams formed by folds of the Syrian Arc, whereas others filled deeply-eroded fault traces. Migration of sand dunes may have blocked some channels, but the location of the dunes seems to be controlled by Recent uplift of parts of the fold belt, with the dunes residing in synclinal depressions and adjacent to fault scarps. The palaeolakes are correlated more with structures than with active dune fields. Wadi El-Arish abandoned a channel west of its present-day course, perhaps because of recent growth and uplift of the Gebel Halal Fold. This abandonment was synchronous with down-cutting of a gorge through Gebel Halal, which follows conjugate faults formed during uplift of an anticline. The presence of standing water during wetter climates in the past is supported by silt deposits and archaeological evidence of previous human habitation. The newly identified lake margin and fluvial sediments could be important targets for studying early-modern human and Neanderthal activities. In the eastern Sahara, cycles of pluvial periods that date back 320,000 years appear to correspond to

  17. Linking seasonal climate forecasts with crop models in Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Capa, Mirian; Ines, Amor; Baethgen, Walter; Rodriguez-Fonseca, Belen; Han, Eunjin; Ruiz-Ramos, Margarita

    2015-04-01

    Translating seasonal climate forecasts into agricultural production forecasts could help to establish early warning systems and to design crop management adaptation strategies that take advantage of favorable conditions or reduce the effect of adverse conditions. In this study, we use seasonal rainfall forecasts and crop models to improve predictability of wheat yield in the Iberian Peninsula (IP). Additionally, we estimate economic margins and production risks associated with extreme scenarios of seasonal rainfall forecast. This study evaluates two methods for disaggregating seasonal climate forecasts into daily weather data: 1) a stochastic weather generator (CondWG), and 2) a forecast tercile resampler (FResampler). Both methods were used to generate 100 (with FResampler) and 110 (with CondWG) weather series/sequences for three scenarios of seasonal rainfall forecasts. Simulated wheat yield is computed with the crop model CERES-wheat (Ritchie and Otter, 1985), which is included in Decision Support System for Agrotechnology Transfer (DSSAT v.4.5, Hoogenboom et al., 2010). Simulations were run at two locations in northeastern Spain where the crop model was calibrated and validated with independent field data. Once simulated yields were obtained, an assessment of farmer's gross margin for different seasonal climate forecasts was accomplished to estimate production risks under different climate scenarios. This methodology allows farmers to assess the benefits and risks of a seasonal weather forecast in IP prior to the crop growing season. The results of this study may have important implications on both, public (agricultural planning) and private (decision support to farmers, insurance companies) sectors. Acknowledgements Research by M. Capa-Morocho has been partly supported by a PICATA predoctoral fellowship of the Moncloa Campus of International Excellence (UCM-UPM) and MULCLIVAR project (CGL2012-38923-C02-02) References Hoogenboom, G. et al., 2010. The Decision

  18. Recent trends of extreme temperature indices for the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Fonseca, D.; Carvalho, M. J.; Marta-Almeida, M.; Melo-Gonçalves, P.; Rocha, A.

    2016-08-01

    Climate change and extreme climate events have a significant impact on societies and ecosystems. As a result, climate change projections, especially related with extreme temperature events, have gained increasing importance due to their impacts on the well-being of the population and ecosystems. However, most studies in the field are based on coarse global climate models (GCMs). In this study, we perform a high resolution downscaling simulation to evaluate recent trends of extreme temperature indices. The model used was Weather Research and Forecast (WRF) forced by MPI-ESM-LR, which has been shown to be one of the more robust models to simulate European climate. The domain used in the simulations includes the Iberian Peninsula and the simulation covers the 1986-2005 period (i.e. recent past). In order to study extreme temperature events, trends were computed using the Theil-Sen method for a set of temperature indexes defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). For this, daily values of minimum and maximum temperatures were used. The trends of the indexes were computed for annual and seasonal values and the Mann-Kendall Trend test was used to evaluate their statistical significance. In order to validate the results, a second simulation, in which WRF was forced by ERA-Interim, was performed. The results suggest an increase in the number of warm days and warm nights, especially during summer and negative trends for cold nights and cold days for the summer and spring. For the winter, contrary to the expected, the results suggest an increase in cold days and cold nights (warming hiatus). This behavior is supported by the WRF simulation forced by ERA-Interim for the autumn days, pointing to an extension of the warming hiatus phenomenon to the remaining seasons. These results should be used with caution since the period used to calculate the trends may not be long enough for this purpose. However, the general sign of trends are similar for

  19. Regionalisation of precipitation for the Iberian Peninsula and climate change

    NASA Astrophysics Data System (ADS)

    Parracho, A. C.; Melo-Gonçalves, P.; Rocha, A.

    2016-08-01

    Temporal variability of precipitation over the Iberian Peninsula (IP) has high spatial gradients. Therefore, statistics of the temporal behaviour of precipitation and derived quantities over the IP must be estimated taking into account these spatial gradients. Some statistics can be displayed over a map. However there are statistics, such as Probability Density Functions at each location of the IP, that are impossible to display in a map. Because of this, it is mandatory to reduce the number of degrees of freedom which, in this case, consists of a reduction of the time series representative of the IP domain. In this work, we present a spatial partition of the IP region into areas of similar precipitation. For that, an observed dataset of daily-total precipitation for the years between 1951 and 2003 was used. The land-only high resolution data was obtained on a regular grid with 0.2° resolution in the IP domain. This data was subjected to a k-means Cluster Analysis in order to divide the IP into K regions. The clustering was performed using the squared Euclidean distance. Four clusters of IP grid points, defining 4 IP regions, were identified. The grid points in each region share the same time-varying behaviour which is different from region to region. The annual precipitation discriminates the following regions: (1) north Iberia, (2) a large region extending from the centre to the Mediterranean shores of the IP, (3) a large region ranging from the centre to the western and southwestern shores of the Iberia, and (4) northwest Iberia. The regions obtained for the four seasons of the year are similar. These results are consistent with the thermodynamic characteristics described in the available literature. These Iberian regions were used to assess climate change of seasonal precipitation from the multi-model ensemble of the fifteen simulations provided by the European project ENSEMBLES. Probability Density Functions of annual- and seasonal-total precipitation

  20. 75 FR 2920 - In the Matter of the Designation of al-Qa'ida in the Arabian Peninsula (AQAP), Also Known as al...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ... al-Qa'ida Organization in the Arabian Peninsula (AQAP), Also Known as al-Qa'ida in Yemen (AQY), Also... Organization in the Arabian Peninsula (AQAP), also known as al-Qa'ida in Yemen (AQY), also known as...

  1. Detection of surface and subsurface conditions in permafrost area after wildfire by using satellite images, Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Harada, K.; Narita, K.; Saito, K.; Iwahana, G.; Sawada, Y.; Fukuda, M.

    2013-12-01

    In 1971 and 2002, large tundra fires burned a wide area that is underlain by discontinuous permafrost near the Kougarok River on the Seward Peninsula in western Alaska. Both fires destroyed the vegetation and altered the ground surface thermal conditions. The objective of this study is to understand the characteristics of the post-fire variations in the distribution and condition of the permafrost and of the changes attributed to the wildfire in the thermal and water conditions in the active layer. Especially, we tried to detect thaw depth, surface and subsurface conditions by using satellite images. Summer field observations were conducted at both burned and unburned sites in the area beginning in 2005. The average thaw depth at the burned sites in 2012 was 30% deeper than the depths at the unburned sites. The differences in thaw depth have decreased over time. Boring surveys up to a depth of 2 m conducted in 2012 confirm the presence of massive ice at both sites, which implies the possibility of thermokarst development caused by the thawing of the permafrost after wildfires. The visible satellite image for the burned site detected white-colored areas, corresponding to Clamagrostis canadensis growing areas, surrounded by green-colored areas. The thaw depth at the white-colored areas was deeper by 60% than at the surrounding burned areas. The surface roughness values were also high at these white-colored areas. There was a significant difference in the normalized difference vegetation index (NDVI) between the white-colored areas and the other areas. Thus, satellite images of areas after wildfires may help detect low NDVI areas that have a deeper thaw depth with the possibility of thermokarst development.

  2. Evaluation's Contribution to the Success of a Silicon Valley School/Industry Partnership: The Peninsula Academies Evaluation.

    ERIC Educational Resources Information Center

    Jung, Steven M.; And Others

    In an effort to encourage the participation of educationally disadvantaged youth in the Silicon Valley's high technology employment boom, the Peninsula Academies program was established utilizing a triad-partnership arrangement among the Sequoia Union High School District, high technology employers in the area, and the Stanford Mid-Peninsula Urban…

  3. 50 CFR Figure 6 to Subpart E of... - Alaska Peninsula and Aleutian Islands Rural and Non-Rural Areas

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Alaska Peninsula and Aleutian Islands Rural and Non-Rural Areas 6 Figure 6 to Subpart E of Part 300 Wildlife and Fisheries INTERNATIONAL..., Subpt. E, Fig. 6 Figure 6 to Subpart E of Part 300—Alaska Peninsula and Aleutian Islands Rural and...

  4. 75 FR 26986 - Notice of Intent To Prepare an Amendment to the Kobuk-Seward Peninsula Resource Management Plan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... Bureau of Land Management Notice of Intent To Prepare an Amendment to the Kobuk-Seward Peninsula Resource Management Plan for the Squirrel River Special Recreation Management Area, Alaska AGENCY: Bureau of Land... Field Office intends to amend the Kobuk-Seward Peninsula Resource Management Plan (KSP/RMP) to...

  5. 75 FR 71107 - Upper Peninsula Power Company; UP Hydro; Notice of Application for Transfer of License, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... Energy Regulatory Commission Upper Peninsula Power Company; UP Hydro; Notice of Application for Transfer..., Upper Peninsula Power Company (transferor) and UP Hydro (transferee) filed an application for transfer... under http://www.ferc.gov/docs-filing/efiling.asp . Commenters can submit brief comments up to...

  6. Presence of the leech Placobdella costata in the south of the Iberian Peninsula.

    PubMed

    Romero, David; Duarte, Jesús; Narváez-Ledesma, Lucía; Farfán, Miguel Angel; Real, Raimundo

    2014-06-01

    Placobdella costata is a leech specific to freshwater turtle Emys orbicularis. Both genera are native to North America and have co-evolved and undergone dispersion through the Palearctic. The leech is present throughout the Mediterranean area, always associated with E. orbicularis. Their only known presence in the Iberian Peninsula is in the north and center of the peninsula. Here we present the first description of the leech in southern Spain (Andalusia) in association with a small fragmented population of fresh-water turtles in which E. orbicularis and Mauremys leprosa coexist. Unusually, the leech was found attached to the carapace of a male M. leprosa.

  7. An outbreak of type E botulism among common loons (Gavia immer) in Michigan's Upper Peninsula

    USGS Publications Warehouse

    Brand, Christopher J.; Schmitt, Stephen; Duncan, Ruth M.; Cooley, Thomas M.

    1988-01-01

    An epizootic of type E botulism (Clostridium botulinum) occurred among common loons (Gavia immer) along the Lake Michigan shore of Michigan's Upper Peninsula (USA) during October and November 1983. An estimated 592 dead loons washed ashore along the Garden Peninsula. Type E botulinal toxin was demonstrated in blood samples and stomach contents of dead loons, and in samples of three species of dead fish found on the Lake Michigan shore. We suspect that loons acquired botulism by ingesting sick or dead fish containing type E toxin.

  8. GPS and GIS-Based Data Collection and Image Mapping in the Antarctic Peninsula

    USGS Publications Warehouse

    Sanchez, Richard D.

    1999-01-01

    High-resolution satellite images combined with the rapidly evolving global positioning system (GPS) and geographic information system (GIS) technology may offer a quick and effective way to gather information in Antarctica. GPS- and GIS-based data collection systems are used in this project to determine their applicability for gathering ground truthing data in the Antarctic Peninsula. These baseline data will be used in a later study to examine changes in penguin habitats resulting in part from regional climate warming. The research application in this study yields important information on the usefulness and limits of data capture and high-resolution images for mapping in the Antarctic Peninsula.

  9. Presence of the leech Placobdella costata in the south of the Iberian Peninsula.

    PubMed

    Romero, David; Duarte, Jesús; Narváez-Ledesma, Lucía; Farfán, Miguel Angel; Real, Raimundo

    2014-06-01

    Placobdella costata is a leech specific to freshwater turtle Emys orbicularis. Both genera are native to North America and have co-evolved and undergone dispersion through the Palearctic. The leech is present throughout the Mediterranean area, always associated with E. orbicularis. Their only known presence in the Iberian Peninsula is in the north and center of the peninsula. Here we present the first description of the leech in southern Spain (Andalusia) in association with a small fragmented population of fresh-water turtles in which E. orbicularis and Mauremys leprosa coexist. Unusually, the leech was found attached to the carapace of a male M. leprosa. PMID:24827095

  10. Forest statistics for Michigan`s northern lower peninsula unit, 1993. Forest Service research bulletin

    SciTech Connect

    Leatherberry, E.C.

    1994-10-30

    Michigan`s Northern Lower Peninsula Unit (fig. 1) is comprised of 33 counties. This region of the State is rich with resources that support a network of social, economic, and ecological processes that are forest dependent. The forest resource of the Unit presently supports an industry that operates on a sustaining basis. In 1990 nearly half of Michigan`s saw-log production--297 million board feet--was harvest in the Unit. The forests of the Northern Lower Peninsula are vital to the region. The forest contains a variety of both deciduous and coniferous forest species, which results in regionally unique ecosystems that contribute to biodiversity.

  11. Evaluation of high-resolution MetUM and AMPS forecasts of near-surface meteorological variables over Larsen C ice shelf and northern Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Orr, Andrew; Kirchgaessner, Amelie; King, John; Weeks, Mark; Gadian, Alan; Kuipers Munneke, Peter; van den Broeke, Michiel; Steffen, Konrad

    2016-04-01

    High-resolution weather forecasts are an important tool for understanding the detailed patterns of surface melt on the Larsen C ice shelf (LCIS), Antarctic Peninsula. We investigate the skill of UK Met Office Unified Model (MetUM) and Antarctic Mesoscale Prediction System (AMPS) forecasts with horizontal grid spacing of 4-5 km for a 1 month period during January-February 2011 by comparing near-surface model output to automatic weather station measurements at 5 sites on the LCIS and 3 on the northern Antarctic Peninsula. Forecasts for the range 12-24 h showed a fairly homogeneous performance over the LCIS. The 2 m temperature simulated by AMPS has a correlation with observations of 0.5-0.6 and a systematic cold bias of around -1 degrees centigrade. By comparison, the MetUM had a higher correlation and was less negatively biased. The simulated surface pressure has a correlation of 0.99 and small biases in both models. AMPS yielded better results than the MetUM for 10 m wind speed, being able to capture particularly well synoptically-driven high wind speeds which the MetUM systematically underestimated. Both models struggle to simulate the 10 m wind direction when the wind conditions are highly variable. The simulation of specific humidity by both models was poor. Both models showed a general reduction in performance over the northern Antarctic Peninsula compared to the LCIS. Extending the analysis to consider the 12-36 h forecast range demonstrated a relatively weak dependence of model skill to the length of the forecast. The study focuses particularly on the representation of foehn wind events, which are an important contributor to surface melt over the LCIS, by examining additional ~1 km scale forecasts using the MetUM.

  12. U‒Pb age of detrital zircons from Upper Precambrian deposits of the Sredni and Rybachi peninsulas (northern margin of the Kola Peninsula)

    NASA Astrophysics Data System (ADS)

    Mikhailenko, Yu. V.; Soboleva, A. A.; Hourigan, J. K.

    2016-09-01

    The first U‒Pb dates are obtained for detrital zircons from Upper Precambrian deposits of the Sredni (Zemlepakhtinskaya and Kuyakan formations) and Rybachi (Lonskii Formation) peninsulas. The spectra of ages of detrital zircons in sandstone samples from the Zemlepakhtinskaya and Kuyakan formations are similar to a significant extent to each other, which implies the dominant role of the same provenances. Most zircon grains are the Paleoproterozoic and Mesoproterozoic in age; some of them are characterized by Mesoarchean and Neoarchean ages. Zircons dated back to 1.0‒2.0 Ga with maxima at approximately 1.8, 1.5, 1.3, and 1.1 Ga are the most abundant. The youngest zircon grains are the Mesoproterozoic in age: 1050 ± 21Ma (i.e., close to the Mesoproterozoic‒Neoproterozoic boundary) and 1028 ± 21 Ma from the Zemlepakhtinskaya and Kuyakan formations, respectively. The distribution spectrum of ages obtained for zircons from sandstones of the Lonskii Formation significantly differs from that characteristic of zircons from sandstones of the Zemlepakhtinskaya and Kuyakan formations. The zircon population from the Lonskii Formation is dominated by detrital zircons with Neoarchean and Paleoproterozoic ages (2.8‒1.6 Ga); Paleoarchean and Mesoarchean grains are scarce. Their age maxima are registered at levels of approximately 2.7 and 1.8 Ga. The minimum age obtained for zircons from sandstones of the Lonskii Formation (1349 ± 35 Ma) allows the Rybachi block to be considered as being older as compared with the Sredni bock. Crystalline complexes of the Baltic Shield served as a main provenance for the Upper Precambrian deposits of the peninsulas under consideration. The dates obtained for detrital zircons from the Upper Precambrian deposits of the Sredni and Rybachi peninsulas are compared with similar data on the Upper Precambrian sequences of the Timan and Varanger Peninsula areas to reveal differences and similarities in the distribution of ages.

  13. An 40Ar/39Ar geochronology on a mid-Eocene igneous event on the Barton and Weaver peninsulas: Implications for the dynamic setting of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Zheng, Xiang-Shen; Lee, Jong I. K.; Choe, Won Hie; Evans, Noreen; Zhu, Ri-Xiang

    2009-12-01

    The genesis of basaltic to andesitic lavas, mafic dikes, and granitoid plutons composing the subaerial cover on the Barton and Weaver peninsulas, Antarctica, is related to arc formation and subduction processes. Precise dating of these polar rocks using conventional 40Ar/39Ar techniques is compromised by the high degree of alteration (with loss on ignition as high as 8%). In order to minimize the alteration effects we have followed a sample preparation process that includes repeated acid leaching, acetone washing, and hand picking, followed by an overnight bake at 250°C. After this procedure, groundmass samples can yield accurate age plateaus consisting of 70%-100% of the total 39Ark released using high-resolution heating schedules. The different rock types studied on the Barton and Weaver peninsulas yielded almost coeval ages, suggesting a giant igneous event in the Weaver and Barton peninsulas at 44.5 Ma. A compilation of newly published ages indicate that this event took place throughout the whole South Shetland Islands, suggesting a dynamic incident occurred at this stage during the arc evolution history. We related this igneous event to a mantle delamination mechanism during Eocene times. The delamination process began at ˜52 Ma, and the resultant upwelling of asthenosphere baffled the subduction of Phoenix plate, causing an abrupt decrease in convergence rate. Then multiple magmatic sources were triggered, resulting in a culminating igneous activity during 50-40 Ma with a peak at ˜45 Ma along the archipelago. The delamination also caused the extension regime indicated by the dike swarm, plugs and sills all over the archipelago, and the uplift of Smith metamorphic complex and Livingston Island. Delamination process may have finished at some time during 40-30 Ma, leaving a weak igneous activity at that stage and thereafter. The convergence rate then recovered gradually, as indicated by the magnetic anomaly identifications. This model is supported by seismic

  14. Seasonality of blue and fin whale calls and the influence of sea ice in the Western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Širović, Ana; Hildebrand, John A.; Wiggins, Sean M.; McDonald, Mark A.; Moore, Sue E.; Thiele, Deborah

    2004-08-01

    The calling seasonality of blue ( Balaenoptera musculus) and fin ( B. physalus) whales was assessed using acoustic data recorded on seven autonomous acoustic recording packages (ARPs) deployed from March 2001 to February 2003 in the Western Antarctic Peninsula. Automatic detection and acoustic power analysis methods were used for determining presence and absence of whale calls. Blue whale calls were detected year round, on average 177 days per year, with peak calling in March and April, and a secondary peak in October and November. Lowest calling rates occurred between June and September, and in December. Fin whale calling rates were seasonal with calls detected between February and June (on average 51 days/year), and peak calling in May. Sea ice formed a month later and retreated a month earlier in 2001 than in 2002 over all recording sites. During the entire deployment period, detected calls of both species of whales showed negative correlation with sea ice concentrations at all sites, suggesting an absence of blue and fin whales in areas covered with sea ice. A conservative density estimate of calling whales from the acoustic data yields 0.43 calling blue whales per 1000 n mi 2 and 1.30 calling fin whales per 1000 n mi 2, which is about one-third higher than the density of blue whales and approximately equal to the density of fin whales estimated from the visual surveys.

  15. A case of bilateral macrodontia of mandibular second premolars from a Chalcolithic context in the Iberian Peninsula.

    PubMed

    López-Onaindia, Diego; Otxoa de Amezaga, Amaia; Subirà, M Eulàlia

    2015-01-01

    Isolated macrodontia, consisting of the gigantism of a single tooth, is an extremely rare condition. Only 16 cases of isolated macrodontia of mandibular second premolars have been reported to date. Although the aetiology of this phenomenon remains unknown, many authors have related it to the control of the apoptotic process, leading to the patterning and size of dental cusps. There is not a clear genetic inheritance pattern since only two of those 16 cases correspond to close relatives. To our knowledge, there have been no reports of isolated macrodontia of mandibular second premolars in archaeological remains. Cova del Pantà de Foix site is a Chalcolithic sepulchral cave situated in the North-East of the Iberian Peninsula in which the remains of at least 30 individuals were recovered. Most of these individuals show several signs of environmental stressors. The current study presents the first case of isolated bilateral macrodontia of mandibular premolars from an archaeological context, corresponding to a young male individual discovered in this site. This condition could be the last consequence of environmental factors epigenetically affecting apoptosis processes in early tooth development and a possible genetic predisposition to show a shape-deviation in the dentition. PMID:26133014

  16. Geospatial variability of soil CO2-C exchange in the main terrestrial ecosystems of Keller Peninsula, Maritime Antarctica.

    PubMed

    Thomazini, A; Francelino, M R; Pereira, A B; Schünemann, A L; Mendonça, E S; Almeida, P H A; Schaefer, C E G R

    2016-08-15

    Soils and vegetation play an important role in the carbon exchange in Maritime Antarctica but little is known on the spatial variability of carbon processes in Antarctic terrestrial environments. The objective of the current study was to investigate (i) the soil development and (ii) spatial variability of ecosystem respiration (ER), net ecosystem CO2 exchange (NEE), gross primary production (GPP), soil temperature (ST) and soil moisture (SM) under four distinct vegetation types and a bare soil in Keller Peninsula, King George Island, Maritime Antarctica, as follows: site 1: moss-turf community; site 2: moss-carpet community; site 3: phanerogamic antarctic community; site 4: moss-carpet community (predominantly colonized by Sanionia uncinata); site 5: bare soil. Soils were sampled at different layers. A regular 40-point (5×8 m) grid, with a minimum separation distance of 1m, was installed at each site to quantify the spatial variability of carbon exchange, soil moisture and temperature. Vegetation characteristics showed closer relation with soil development across the studied sites. ER reached 2.26μmolCO2m(-2)s(-1) in site 3, where ST was higher (7.53°C). A greater sink effect was revealed in site 4 (net uptake of 1.54μmolCO2m(-2)s(-1)) associated with higher SM (0.32m(3)m(-3)). Spherical models were fitted to describe all experimental semivariograms. Results indicate that ST and SM are directly related to the spatial variability of CO2 exchange. Heterogeneous vegetation patches showed smaller range values. Overall, poorly drained terrestrial ecosystems act as CO2 sink. Conversely, where ER is more pronounced, they are associated with intense soil carbon mineralization. The formations of new ice-free areas, depending on the local soil drainage condition, have an important effect on CO2 exchange. With increasing ice/snow melting, and resulting widespread waterlogging, increasing CO2 sink in terrestrial ecosystems is expected for Maritime Antarctica. PMID:27110991

  17. Pan American Airways/Naval Air Transport Service/destroyer base site at the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pan American Airways/Naval Air Transport Service/destroyer base site at the east side showing walkway and building foundation. View facing west-northwest. - U.S. Naval Base, Pearl Harbor, Pearl City Peninsula, Pearl City, Honolulu County, HI

  18. 50 CFR 300.103 - Procedure for according protection to CCAMLR Ecosystem Monitoring Program Sites.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... change is a violation of this subpart and voids the application or permit, as applicable. Title 15 CFR... listed at 45 CFR part 670 subparts G and H. (2) The following sites have been identified as CEMP... Shirreff peninsula north of the glacier ice tongue margin, and most of the San Telmo Island group. For...

  19. 50 CFR 300.103 - Procedure for according protection to CCAMLR Ecosystem Monitoring Program Sites.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... change is a violation of this subpart and voids the application or permit, as applicable. Title 15 CFR... listed at 45 CFR part 670 subparts G and H. (2) The following sites have been identified as CEMP... Shirreff peninsula north of the glacier ice tongue margin, and most of the San Telmo Island group. For...

  20. 50 CFR 300.103 - Procedure for according protection to CCAMLR Ecosystem Monitoring Program Sites.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... change is a violation of this subpart and voids the application or permit, as applicable. Title 15 CFR... listed at 45 CFR part 670 subparts G and H. (2) The following sites have been identified as CEMP... Shirreff peninsula north of the glacier ice tongue margin, and most of the San Telmo Island group. For...

  1. 50 CFR 300.103 - Procedure for according protection to CCAMLR Ecosystem Monitoring Program Sites.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... change is a violation of this subpart and voids the application or permit, as applicable. Title 15 CFR... listed at 45 CFR part 670 subparts G and H. (2) The following sites have been identified as CEMP... Shirreff peninsula north of the glacier ice tongue margin, and most of the San Telmo Island group. For...

  2. 50 CFR 300.103 - Procedure for according protection to CCAMLR Ecosystem Monitoring Program Sites.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... change is a violation of this subpart and voids the application or permit, as applicable. Title 15 CFR... listed at 45 CFR part 670 subparts G and H. (2) The following sites have been identified as CEMP... Shirreff peninsula north of the glacier ice tongue margin, and most of the San Telmo Island group. For...

  3. Lateglacial and Holocene climate, disturbance and permafrost peatland dynamics on the Seward Peninsula, western Alaska

    NASA Astrophysics Data System (ADS)

    Hunt, Stephanie; Yu, Zicheng; Jones, Miriam

    2013-03-01

    Northern peatlands have accumulated large carbon (C) stocks, acting as a long-term atmospheric C sink since the last deglaciation. How these C-rich ecosystems will respond to future climate change, however, is still poorly understood. Furthermore, many northern peatlands exist in regions underlain by permafrost, adding to the challenge of projecting C balance under changing climate and permafrost dynamics. In this study, we used a paleoecological approach to examine the effect of past climates and local disturbances on vegetation and C accumulation at a peatland complex on the southern Seward Peninsula, Alaska over the past ˜15 ka (1 ka = 1000 cal yr BP). We analyzed two cores about 30 m apart, NL10-1 (from a permafrost peat plateau) and NL10-2 (from an adjacent thermokarst collapse-scar bog), for peat organic matter (OM), C accumulation rates, macrofossil, pollen and grain size analysis. A wet rich fen occurred during the initial stages of peatland development at the thermokarst site (NL10-2). The presence of tree pollen from Picea spp. and Larix laricinia at 13.5-12.1 ka indicates a warm regional climate, corresponding with the well-documented Bølling-Allerød warm period. A cold and dry climate interval at 12.1-11.1 ka is indicated by the disappearance of tree pollen and increase in Poaceae pollen and an increase in woody material, likely representing a local expression of the Younger Dryas (YD) event. Following the YD, the warm Holocene Thermal Maximum (HTM) is characterized by the presence of Populus pollen, while the presence of Sphagnum spp. and increased C accumulation rates suggest high peatland productivity under a warm climate. Toward the end of the HTM and throughout the mid-Holocene a wet climate-induced several major flooding disturbance events at 10 ka, 8.1 ka, 6 ka, 5.4 ka and 4.7 ka, as evidenced by decreases in OM, and increases in coarse sand abundance and aquatic fossils (algae Chara and water fleas Daphnia). The initial peatland at permafrost

  4. Genesis of a zoned granite stock, Seward Peninsula, Alaska

    USGS Publications Warehouse

    Hudson, Travis

    1977-01-01

    A composite epizonal stock of biotite granite has intruded a diverse assemblage of metamorphic rocks in the Serpentine Hot Springs area of north-central Seward Peninsula, Alaska. The metamorphic rocks include amphibolite-facies orthogneiss and paragneiss, greenschist-facies fine-grained siliceous and graphitic metasediments, and a variety of carbonate rocks. Lithologic units within the metamorphic terrane trend generally north-northeast and dip moderately toward the southeast. Thrust faults locally juxtapose lithologic units in the metamorphic assemblage, and normal faults displace both the metamorphic rocks and some parts of the granite stock. The gneisses and graphitic metasediments are believed to be late Precambrian in age, but the carbonate rocks are in part Paleozoic. Dating by the potassium-argon method indicates that the granite stock is Late Cretaceous. The stock has sharp discordant contacts, beyond which is a well-developed thermal aureole with rocks of hornblende hornfels facies. The average mode of the granite is 29 percent plagioclase, 31 percent quartz, 36 percent K-feldspar, and 4 percent biotite. Accessory minerals include apatite, magnetite, sphene, allanite, and zircon. Late-stage or deuteric minerals include muscovite, fluorite, tourmaline, quartz, and albite. The stock is a zoned complex containing rocks with several textural facies that are present in four partly concentric zones. Zone 1 is a discontinuous border unit, containing fine- to coarse-grained biotite granite, that grades inward into zone 2. Zone 2 consists of porphyritic biotite granite with oriented phenocrysts of pinkish-gray microcline in a coarse-grained equigranular groundmass of plagioclase, quartz, and biotite. It is in sharp, concordant to discordant contact with rocks of zone 3. Zone 3 consists of seriate-textured biotite granite that has been intruded by bodies of porphyritic biotite granite containing phenocrysts of plagioclase, K-feldspar, quartz, and biotite in an

  5. Perspective View, Landsat Overlay, Salalah, Oman, Southern Arabian Peninsula

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This perspective view includes the city of Salalah, the second largest city in Oman. The city is located on the broad, generally bright coastal plain and includes areas of green irrigated crops. This view was generated from a Landsat image draped over a preliminary elevation model produced by the Shuttle Radar Topography Mission (SRTM). The edges of the dataset are to the upper right, left, and lower left. The Arabian Sea (lower right) is represented by the blue false-colored area. Vertical exaggeration of topography is 3X.

    This scene illustrates how topography determines local climate and, in turn, where people live. The Arabian Peninsula is very arid. However, the steep escarpment of the Qara Mountains wrings moisture from the summer monsoons allowing for growth of natural vegetation (green along the mountain fronts and in the canyons), and soil development (dark brown areas), as well as cultural development of the coastal plain. The monsoons also provide moisture for Frankincense trees growing on the desert (north) side of the mountains. In ancient times, incense derived from the sap of the Frankincense tree was the basis for an extremely lucrative trade.

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

    Elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar(SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was

  6. Coastal and Oceanic SST variability along the western Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Santos, F.; Gómez Gesteira, M.; Decastro, M.; Álvarez, I.

    2010-09-01

    Trends in coastal and oceanic Sea Surface Temperature (SST) were analyzed along the western Iberian Peninsula for the period 1900-2008. SST data were obtained from the UK Meteorological Office, Hadley Centre (http://badc.nerc.ac.uk/data/hadisst). Nodes were distributed on a 1°x1° grid with monthly periodicity. Twelve points were considered from 37°N to 43°N, six at coastal locations (9°W) and six at oceanic locations (14°W). SST has undergone several periods of warming and cooling during the last century. In particularly, two warming periods (from 1900 to 1955 and from 1970 to 2008), and one cooling period (from 1955 to 1975). In addition, the increment of SST (ΔSST) has been calculated as the SST difference between coastal and ocean locations at the same latitude. This parameter has been used by some authors to characterize the upwelling (Nykjaer & VanCamp, 1994). In the inter-annual evolution of the average of ΔSST: two of increase (from 1920 to 1950 and from 1980 to 2008) and one of decrease (from 1950 to 1980). The same study was carried out seasonally. Three seasons were selected according to the periods of high, moderate or low ΔSST: November-February (NDJF); March-June (MAMJ) and July-October (JASO). The greatest differences between coast and ocean were observed during JASO and lowest ones during MAMJ. Negative values were detected during the whole year being more negative from July to September coinciding with the upwelling season (Alvarez et al., 2005). The seasonal ΔSST shows the same increase and decrease cycles as the annual ΔSST evolution. SST patterns showed that warming and cooling trends were less intense near coast than in the ocean. The possible causes of this behavior were analyzed. If the mechanism described by Bakun (1990) and McGregor et al., (2007) is assumed, coastal upwelling is revealed as the main cause of this behavior. On the contrary, when upwelling index evolution is calculated from wind data, coastal upwelling is not

  7. Three Storm Surge Events during Late Holocene in Shelly Gravel Sediments of the most Southern Coast of Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Yang, Dong Yoon

    2015-04-01

    Super Typhoon Haiyan which occurred in November, 2013 left as many as 5,200 people dead and destroyed towns across the Philippines. However, because of rapid climate change, we cannot disregard such a super typhoon strike probability in Korean Peninsula. If we can detect the frequency and periodicity of paleo-geohazards recorded in sediments, the extreme geohazards can be predicted and its damage can be somewhat mitigated. The geology, geochemistry and mineralogy of the island sediments ahead of Yeongjeon coast, Haenam-gun, the most southern part, Korean peninsula were investigated. Shells from the three shelly gravel layers were used for 14C age dating and cube samples were collected at 5-10cm intervals for measuring the magnetic susceptibility, grain size distribution and geochemical analyses at the study site. Granitic gneiss clasts of debris flow mixed with the weathered tuffaceous materials on the eroded face of tuff rock. The sediments of Pleistocene were also eroded almost horizontally and unconformably covered by late Holocene shelly gravel deposits characterized by some kind of shells and unsorted sub-rounded or rounded gravels to pebbles. The horizontal erosion face is 2.2m in elevation and the current erosion face of beach was observed at 1.2m in elevation. This indicates that the former erosion face would have been formed at higher sea level than those of latter one by the similar mechanism of current erosion in the study site. Three shelly gravel layers overlie the erosion face from 2.2m to 2.9m in elevation. The reflected water energy caused by stronger storm would have been needed for delivering gravels and cobbles to the erosion face. Three shell layers dated as 3200 yr BP, 1900 yr BP, and 1700 yr BP, respectively. Four sedimentary units, from unit 1 to 4 in ascending order, are distinguished on the basis of sedimentary textures, shell contents, grain size distribution and vertical color variations. The sand ratios in the grain size distribution

  8. Draft Genome Sequences of Two Xanthomonas euvesicatoria Strains from the Balkan Peninsula

    PubMed Central

    Vancheva, Taca; Lefeuvre, Pierre; Bogatzevska, Nevena; Moncheva, Penka

    2015-01-01

    We report the draft genome sequences of two Xanthomonas euvesicatoria strains from the Balkan Peninsula, which were isolated from symptomatic pepper plants. The availability of these genome sequences will facilitate the development of modern genotyping assays for X. euvesicatoria strains and to define targets for resistance breeding. PMID:25657284

  9. Estimation of Water Availability Considering Climate Change in the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Yoo, S.; Lee, D. K.; Hanasaki, N.

    2015-12-01

    The hydrological cycle is directly affected by climate and human intervention. Climate change is expected to affect hydrology and water resources. In Korean Peninsula, the rainfall pattern is seasonally concentrated, causing temporal and spatial variations in water availability. Many previous studies have investigated that the Korean Peninsula region is vulnerable to changes in water availability with changing climate, but a majority of the studies have focused on natural river discharge. However, the present-day hydrological cycle is not natural, but is affected by human activity, such as the water demands of agriculture, the industrial and domestic sector, and reservoir operations. In this study, water availability considering the impacts of human activity and climate change in the Korean Peninsula region is assessed in terms of water supply and demand. To assess present and future water availability, the integrated water resources model H08, which has six sub-modules to address land surfaces, river routing, crop growth, environmental flow requirements, and anthropogenic water withdrawal (Hanasaki et al., 2008), was applied to simulate historical and future hydrological processes based on climate scenarios. The model was calibrated and validated based on observed river discharge data. The simulation results show the temporal and spatial variations of water availability in the Korean Peninsula region. Results of this research could be used for spatial planning, taking into account the water availability.

  10. Connection between autumn Sea Surface Temperature and winter precipitation in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Fernández-González, Sergio; Pereira, Susana C.; Castro, Amaya; Rocha, Alfredo; Fraile, Roberto

    2014-10-01

    The oceanic influence on winter precipitation in the Iberian Peninsula has been evidenced in numerous scientific papers. Large-scale forecasting models generally use variables such as Sea Surface Temperature (SST), soil moisture and ice cover, but they are not very accurate yet. Using observational data, this paper analyzes the influence of North Atlantic and Mediterranean SST on winter precipitation in the Iberian Peninsula between October 1951 and September 2011. First, trends of both data sets have been calculated to study their behavior during the past six decades, showing an overall increase of SST and a substantial decrease in winter precipitation in the Iberian Peninsula, except in eastern and south-eastern regions. Then, connection patterns between autumn Sea Surface Temperature Anomalies and winter precipitation have been studied to identify ocean regions that may be used as potential predictors of winter precipitation. After applying a Principal Component Analysis to cluster the information provided by the 1431 measuring points of a SST grid with a small number of variables, the Principal Components extracted were introduced into a Multiple Linear Regression algorithm in order to obtain an estimation of winter precipitation in each river basin. The validation process has shown that the algorithm explains nearly 50% of inter-annual variability of winter precipitation in the basins of the Iberian Peninsula with a strongly oceanic influence; this percentage is somewhat lower in the Mediterranean regions.

  11. Geology of the Prince William Sound and Kenai Peninsula region, Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Hults, Chad P.

    2012-01-01

    The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world’s largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska and Aleutian Ranges and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper River delta. Structurally, the map area is cut by a number of major faults and postulated faults, the most important of which are the Border Ranges, Contact, and Bruin Bay Fault systems. The rocks of the map area belong to the Southern Margin composite terrane, a Tertiary and Cretaceous or older subduction-related accretionary complex, and the Alaska Peninsula terrane. Mesozoic rocks between these two terranes have been variously assigned to the Peninsular or the Hidden terranes. The oldest rocks in the map area are blocks of Paleozoic age within the mélange of the McHugh Complex; however, the protolith age of the greenschist and blueschist within the Border Ranges Fault zone is not known. Extensive glacial deposits mantle the Kenai Peninsula and the lowlands on the west side of Cook Inlet and are locally found elsewhere in the map area. This map was compiled from existing mapping, without generalization, and new or revised data was added where available.

  12. Erythemal ultraviolet irradiation trends in the Iberian Peninsula from 1950 to 2011

    NASA Astrophysics Data System (ADS)

    Román, R.; Bilbao, J.; de Miguel, A.

    2014-06-01

    Erythemal ultraviolet (UVER) irradiation was reconstructed at nine Spanish locations, with series starting around 1950 in at least five places. Each series was checked by applying homogeneity tests in order to discard non-homogeneous series. Available series were used to create an averaged Iberian Peninsula UVER series. Results indicate that annual UVER irradiation in the Iberian Peninsula increased by 155 J m-2 (6.5%) between 1950 and 2011 due to a decrease observed in atmospheric ozone rather than changes in aerosol and clouds. Annual UVER irradiation increased by 135 J m-2 (5.6%) between 1985 and 2011, mainly due to changes in aerosol and clouds. UVER irradiation over the open human body (UVERob) was calculated by multiplying daily UVER irradiation by the daily open body fraction, a function of air temperature. Annual UVERob increased by 12.5 % between 1950 and 2011 in the Iberian Peninsula, half of the increase being caused by temperature changes, and the other half by ozone changes. Annual UVERob in the Iberian Peninsula increased by a total of 10.1% between 1985 and 2011, with 20.7%, 35.1% and 44.2% of this increase being caused by changes in ozone, aerosol and clouds, and temperature, respectively.

  13. Late holocene fluctuations in the front of the Muller Ice Shelf, Antarctic Peninsula

    SciTech Connect

    Domack, E.W. ); Stein, A.B. )

    1993-01-01

    Ice shelves are important environmental indicators along the antarctic Peninsula. This study investigates the fluctuation of the Muller Ice Shelf by collecting and analysing surface sediment samples, piston cores, and kasten cores close to the present calving line. 3 refs., 3 figs.

  14. Genesis of peat-bog soils in the northern taiga spruce forests of the Kola Peninsula

    SciTech Connect

    Nikonov, V.V.

    1981-01-01

    The characteristics of soil formation processes in the Peat-Bog soils of waterlogged spruce phytocenoses on the Kola Peninsula are investigated. It is found that the ash composition of the peat layer is determined primarily by the composition of the buried plant residues. The effect of the chemical composition of water feeding the peat bogs is determined. (Refs. 7).

  15. A Survey of Music Education in the Primary Schools of South Africa's Cape Peninsula

    ERIC Educational Resources Information Center

    Herbst, Anri; Wet, Jacques de; Rijsdijk, Susan

    2005-01-01

    We investigated the state of music education in government primary schools in the Cape Peninsula (Western Cape Province, South Africa) as perceived by the general class teacher. Since the first democratic elections in South Africa (1994), the entire primary and secondary school education system has changed drastically in terms of content, and…

  16. Chlorinated hydrocarbons in lichen and moss samples from the Antarctic Peninsula

    SciTech Connect

    Bacci, E.; Calamari, D.; Gaggi, C.; Fanelli, R.; Focardi, S.; Morosini, M.

    1986-01-01

    The concentrations of some chlorinated hydrocarbon residues (HCB, HCH isomers, p,p'DDT and DDE, PCB cogeners) in lichen and moss samples from the Antarctic Peninsula are reported and compared with available data from other parts of the world. The use of these materials as indicators of tropospheric contamination levels in Antarctica is discussed.

  17. Acremonium camtosporum isolated as an endophyte of Bursera simaruba from Yucatan Peninsula, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bursera simaruba (Burseraceae) is a frequent and co-dominant tree of tropical sub-caducifolious forest in the Yucatan Peninsula. This species is important ecologically because it can grow in poor, clay or sandy, saline soils. The Mayan communities use this plant medicinally for its analgesic, antimy...

  18. Tropical cyclone rainfall structure affecting indochina peninsula and lower mekong river basin (LMB)

    NASA Astrophysics Data System (ADS)

    CHHIN, Rattana; Joko Trilaksono, Nurjanna; Wahyu Hadi, Tri

    2016-08-01

    Indochina Peninsula is located in between Bay of Bengal (BoB) and South-China Sea (SCS). This region is affected frequently from Tropical Cyclones (TCs) formed in North Indian Ocean (NIO), South-China Sea (SCS), and North West Pacific Ocean (NWP). This research analyzed the structure of the rainfall over Indochina Peninsula and its relationships with TCs from the aforementioned sources. Principle Component Analysis (PCA) was performed to investigate the dominant rainfall area produced from those TCs. Spatial and Temporal structures of rainfall from the TCs is analyzed to understand their propagation. The results show that the dominant TC rainfall area covers Central Vietnam which contributed around 25% to total rainfall in the region. However, the contribution of this TC rainfall over LMB is likely less than 20% where Laos's territory receives highest contribution (20%). Furthermore, from the three source areas, TCs formed in SCS produce the highest rain rate when they develop into typhoon intensity stage of Joint Typhoon Warning Center (JTWC)’s scale. The average duration of TC rainfall over Indochina Peninsula is 81.28 hours, and over LMB is 66.22 hours. Thus, same as other regions in the Indochina Peninsula, LMB is affected by TC rainfall with considerable scales both spatially and temporally that may lead to significant hydrometeorological hazards.

  19. Diptera of forensic importance in the Iberian Peninsula: larval identification key.

    PubMed

    Velásquez, Y; Magaña, C; Martínez-Sánchez, A; Rojo, S

    2010-09-01

    A revision of the species and families of sarcosaprophagous flies (Diptera: Calliphoridae, Sarcophagidae, Muscidae, Fanniidae, Drosophilidae, Phoridae, Piophilidae and Stratiomyidae) suitable for forensic purposes in the Iberian Peninsula is presented. Morphological characteristics that allow the accurate identification of third instars of the species present in the Iberian Peninsula are described and presented in the form of a diagnostic key. For larval Calliphoridae, characteristics such as the spines of the body segments were useful for the genus Calliphora whereas features of the anal segment and the cephalopharyngeal skeleton were useful for larvae of Lucilia. Identification of three Chrysominae species present in the Iberian Peninsula is included. For larval Sarcophagidae, characters such as the arrangement and shape of spiracular openings, structures of the anal segment and the cephalopharyngeal skeleton were used for the first time. A new record of Sarcophaga cultellata Pandellé, from a human corpse, is also included as well as recent incursions into the European cadaveric entomofauna such as Synthesiomyia nudiseta (van der Wulp) and Hermetia illucens (Linnaeus). This work provides useful new information that could be applied to forensic investigations in the Iberian Peninsula and in southern Europe.

  20. Spectral distribution of gravity wave momentum fluxes over the Antarctic Peninsula from Concordiasi superpressure balloon data

    NASA Astrophysics Data System (ADS)

    Walterscheid, R. L.; Gelinas, L. J.; Mechoso, C. R.; Schubert, G.

    2016-07-01

    Gravity waves generated by flow over the steep topography of the Antarctic Peninsula transport significant amounts of zonal and meridional momentum into the stratosphere. Quantitative determination of this transport has been carried out for wave periods of 1 h or greater using data from a previous Antarctic superpressure balloon campaign in austral spring 2005 (VORCORE). The present study uses data from the later Concordiasi campaign (2010) to extend the momentum flux determination to shorter periods. Maps of the vertical fluxes of meridional and zonal momentum are presented for periods down to 12 min. We find that the momentum fluxes for periods below 1 h are comparable to those at longer periods, despite larger variances at longer periods. The momentum fluxes in the vicinity of the peninsula provide a significant zonal acceleration of the lower stratosphere, confirming a conclusion from the VORCORE data. The geographical distribution of fluxes around the peninsula has peaks both leeward and windward of the main terrain features. Numerical simulations suggest that the separate peaks may be related to wave transience caused by unsteady winds over the peninsula. Momentum fluxes comprise a main distribution maximizing at moderate flux values and a secondary distribution maximizing at high values exhibiting a high degree of intermittency. The high flux events account for the largest part of the average flux and suggest that drag parameterizations should take them into account. It is found that waves generated by the jet stream are also a significant source of momentum flux.

  1. Suez Canal, Gulf of Suez, Sinai Peninsula, Egypt, as seen from the Apollo 7

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Suez Canal, Gulf of Suez, Sinai Peninsula, United Arab Republic (Egypt), Mediterranean Sea, as seen from the Apollo 7 spacecraft during its 13th revolution of the earth. Photographed from an altitude of 126 nautical miles, at ground elapsed time of 19 hours and 42 minutes.

  2. Cretaceous deposits and flora of the Muravyov-Amurskii Peninsula (Amur Bay, sea of Japan)

    NASA Astrophysics Data System (ADS)

    Volynets, E. B.

    2015-05-01

    The Cretaceous sections and plant macrofossils are investigated in detail near Vladivostok on the Muravyov-Amurskii Peninsula of southern Primorye. It is established that the Ussuri and Lipovtsy formations in the reference section of the Markovskii Peninsula rest with unconformity upon Upper Triassic strata. The continuous Cretaceous succession is revealed in the Peschanka River area of the northern Muravyov-Amurskii Peninsula, where plant remains were first sampled from the lower and upper parts of the Korkino Group, which are determined to be the late Albian-late Cenmanian in age. The taxonomic composition of floral assemblages from the Ussuri, Lipovtsy, and Galenki formations is widened owing to additional finds of plant remains. The Korkino Group received floral characteristics for the first time. The Cretaceous flora of the peninsula is represented by 126 taxa. It is established that ferns and conifers are dominant elements of the Ussuri floral assemblage, while the Lipovtsy Assemblage is dominated by ferns, conifers, and cycadphytes. In addition, the latter assemblage is characterized by the highest taxonomic diversity. The Galenki Assemblage is marked by the first appearance of rare flowering plants against the background of dominant ferns and conifers. The Korkino floral assemblage is subdivided into two subassemblages dominated by different groups: conifers in the early and flowering plants in the late.

  3. Genetic differentiation of octopuses from different habitats near the Korean Peninsula and eastern China based on analysis of the mDNA cytochrome C oxidase 1 gene.

    PubMed

    Kang, J-H; Park, J-Y; Choi, T-J

    2012-11-21

    Distributed along the coastal waters of Korea and China, Octopus minor is found in various habitats, including the mud flats in the southern and western coasts of the Korean Peninsula and the rocky areas around Jeju Island; however, the genetic relationships among the different populations are unknown and have not been studied. We compared 630-nucleotide sequences of the CO1 gene from O. minor specimens collected from five regions around the Korean Peninsula and three regions from eastern China in order to determine population structure and genetic relationships. Based on the sequences at 12 polymorphic sites in this region, 11 haplotypes were identified from 85 specimens. Individuals from Jeju Island had unique haplotypes, including two haplotypes not found in the other populations. Nucleotide and haplotype diversity for all populations ranged from 0.03-0.37 and 0.20-0.64, respectively. Pairwise F(ST) values indicated significant genetic differences in populations from Korea and China. An UPGMA dendrogram showed separation of the eight populations into three clusters; one included only the Jeju population, another included the rest of the Korean populations and some from Dalian, China; a third cluster consisted of two other populations from China. We conclude that there are discrete genetic differences in O. minor from the different habitats, suggesting that the populations should be considered as management units in the ongoing recovery program.

  4. An illustrated key to the soft-bottom caprellids (Crustacea: Amphipoda) of the Iberian Peninsula and remarks to their ecological distribution along the Andalusian coast

    NASA Astrophysics Data System (ADS)

    Guerra-García, José M.; Navarro-Barranco, Carlos; Corzo, Juan; Cobos-Muñoz, Vanessa; García-Adiego, Emilio M.; Giménez, Francisco Sempere; García-Gómez, J. Carlos

    2013-06-01

    The soft-bottom caprellids of the Iberian Peninsula are revised. Nineteen species have been reported so far, 42 % being endemic to the Mediterranean Sea. The lateral view of all of them is provided, together with an illustrated key for all the species. An ecological study was also conducted during 2007-2010 along the Andalusian coast to explore the relationships of caprellids with abiotic data. A total of 90 stations (0-40 m deep) were sampled and 40 contained caprellids. Along the Atlantic, caprellids were present in only 20 % of the stations, while along the Mediterranean coast, caprellids were present in the 75 % of the sampling sites. Furthermore, the abundance of caprellids was also higher in the Mediterranean coast. The dominant species was Pseudolirius kroyeri (present in 24 stations and showing the highest abundances with 1,780 ind/m2), followed by Phtisica marina (22 stations) and Pariambus typicus (11 stations). According to CCA and BIO-ENV, sediment type, P, pH and oxygen were the parameters that better explained the distribution of caprellids. Although the three dominant species were found in all types of sediment, the univariate approach showed that P. kroyeri was significantly more abundant in fine sediments (silt-clay and very fine sands) than in gross sediments (coarse and very coarse sands). The majority of studies dealing with caprellids from the Iberian Peninsula have been focused on shallow waters and further efforts are needed to explore biodiversity of deeper areas.

  5. Genetic differentiation of octopuses from different habitats near the Korean Peninsula and eastern China based on analysis of the mDNA cytochrome C oxidase 1 gene.

    PubMed

    Kang, J-H; Park, J-Y; Choi, T-J

    2012-01-01

    Distributed along the coastal waters of Korea and China, Octopus minor is found in various habitats, including the mud flats in the southern and western coasts of the Korean Peninsula and the rocky areas around Jeju Island; however, the genetic relationships among the different populations are unknown and have not been studied. We compared 630-nucleotide sequences of the CO1 gene from O. minor specimens collected from five regions around the Korean Peninsula and three regions from eastern China in order to determine population structure and genetic relationships. Based on the sequences at 12 polymorphic sites in this region, 11 haplotypes were identified from 85 specimens. Individuals from Jeju Island had unique haplotypes, including two haplotypes not found in the other populations. Nucleotide and haplotype diversity for all populations ranged from 0.03-0.37 and 0.20-0.64, respectively. Pairwise F(ST) values indicated significant genetic differences in populations from Korea and China. An UPGMA dendrogram showed separation of the eight populations into three clusters; one included only the Jeju population, another included the rest of the Korean populations and some from Dalian, China; a third cluster consisted of two other populations from China. We conclude that there are discrete genetic differences in O. minor from the different habitats, suggesting that the populations should be considered as management units in the ongoing recovery program. PMID:23212336

  6. Assessment of Darkling Beetle Fauna after Implementation of an Environmental Restoration Program in the Southern Iberian Peninsula Affected by the Aznalcóllar Toxic Spill

    PubMed Central

    Cárdenas, Ana M.; Bujalance, José L.; Hidalgo, Juan M.

    2011-01-01

    This study is part of the Follow up Restoration Program of animal communities that colonize the Guadiamar River Basin. In 1998, the area was affected by a release of toxic sludge after the retention walls of the Aznalcóllar Mines (southern Iberian Peninsula) broke. The main objective of this study was to assess the current state of the population of Tenebrionidae, one of the most representative groups of edaphic Coleoptera inhabiting the Guadiamar River Basin. This paper analyses the progress made by the darkling beetle community six years after the disaster occurred and the Restoration Program was implemented. The study is based on faunistic data from systematic sampling carried out for six years to monitor plots distributed across the damaged area. To make an overall assessment of the tenebrionid fauna in relation to adjacent areas qualitative and quantitative ecological indices were applied, and temporal follow up and biogeographical comparisons were also made. The results indicate that, on the whole, tenebrionid fauna was somewhat affected by the Aznalcóllar Mine spill, and that a greater loss of fauna was detected closer to the accident site. The analysis of the temporal population dynamic suggests that the most affected zones are undergoing a process of re-colonization. However, this process varies widely by species and has not yet reached the expected levels of a non-affected river basin in the southern Iberian Peninsula. PMID:21864152

  7. Advective pathways near the tip of the Antarctic Peninsula: Trends, variability and ecosystem implications

    NASA Astrophysics Data System (ADS)

    Renner, Angelika H. H.; Thorpe, Sally E.; Heywood, Karen J.; Murphy, Eugene J.; Watkins, Jon L.; Meredith, Michael P.

    2012-05-01

    Pathways and rates of ocean flow near the Antarctic Peninsula are strongly affected by frontal features, forcings from the atmosphere and the cryosphere. In the surface mixed layer, the currents advect material from the northwestern Weddell Sea on the eastern side of the Peninsula around the tip of the Peninsula to its western side and into the Scotia Sea, connecting populations of Antarctic krill (Euphausia superba) and supporting the ecosystem of the region. Modelling of subsurface drifters using a particle tracking algorithm forced by the velocity fields of a coupled sea ice-ocean model (ORCA025-LIM2) allows analysis of the seasonal and interannual variability of drifter pathways over 43 years. The results show robust and persistent connections from the Weddell Sea both to the west into the Bellingshausen Sea and across the Scotia Sea towards South Georgia, reproducing well the observations. The fate of the drifters is sensitive to their deployment location, in addition to other factors. From the shelf of the eastern Antarctic Peninsula, the majority enter the Bransfield Strait and subsequently the Bellingshausen Sea. When originating further offshore over the deeper Weddell Sea, drifters are more likely to cross the South Scotia Ridge and reach South Georgia. However, the wind field east and southeast of Elephant Island, close to the tip of the Peninsula, is crucial for the drifter trajectories and is highly influenced by the Southern Annular Mode (SAM). Increased advection and short travel times to South Georgia, and reduced advection to the western Antarctic Peninsula can be linked to strong westerlies, a signature of the positive phase of the SAM. The converse is true for the negative phase. Strong westerlies and shifts of ocean fronts near the tip of the Peninsula that are potentially associated with both the SAM and the El Niño-Southern Oscillation restrict the connection from the Weddell Sea to the west, and drifters then predominantly follow the open

  8. Links between Synoptic Weather Types and Extreme Wet Events in the Arabian Peninsula (1960-2100)

    NASA Astrophysics Data System (ADS)

    Kenawy, Ahmed; McCabe, Matthew; Stenchikov, Georgiy; Raj, Jerry

    2014-05-01

    In this work, an automated version of the Lamb weather type classification scheme was applied to classify daily weather types in the Arabian Peninsula. The output catalogue included ten basic weather types, which describe the direction and vorticity of airflow in the peninsula (i.e., cyclonic, anticyclonic and directional). These large-scale patterns were first defined for the observed climate (1960-2013), allowing for an assessment of the spatial and temporal variations in circulation-rainfall relationships over the peninsula using rainfall data from 209 weather observatories. The same methodology was then applied to assess how the defined weather types will be presented in future climate simulations (under RCP45 and RCP85 emission scenarios) and to explore their probable dependency with rainfall characteristics. In this regard, daily simulated SLP derived from an ensemble of 12 climate models within the CMIP5 project were used for two future time-slices (2035-2060 and 2075-2100). Our findings indicate that the cyclonic (C) type represented the most frequent classification with 69.2% of days, followed by SE directional flows (21%). It was also found that the main circulation features influencing winter (spring) rainfall across the peninsula are the strong influence of the anticyclonic (easterly and southeasterly) air masses. Generally, the role of airflows originating from the Indian Ocean is larger than those of the Mediterranean and the Red Seas. The trend results of defined weather types show that the cyclonic (anticyclonic) conditions tend to decrease (increase). This picture is likely to continue during the 21st century. The only exception corresponds to the summer season. Here, understanding the association between atmospheric circulation patterns and rainfall in the Arabian Peninsula can be important for the understanding of climatic variability and thus developing circulation-based downscaling methods in this region.

  9. Homogenization dynamics and introduction routes of invasive freshwater fish in the Iberian Peninsula.

    PubMed

    Clavero, Miguel; García-Berthou, Emili

    2006-12-01

    Nonnative invasive species are one of the main global threats to biodiversity. The understanding of the traits characterizing successful invaders and invasion-prone ecosystems is increasing, but our predictive ability is still limited. Quantitative information on biotic homogenization and particularly its temporal dynamics is even scarcer. We used freshwater fish distribution data in the Iberian Peninsula in four periods (before human intervention, 1991, 1995, and 2001) to assess the temporal dynamics of biotic homogenization among river basins. The percentage of introduced species among fish faunas has increased in recent times (from 41.8% in 1991 to 52.5% in 2001), leading to a clear increase in the similarity of community composition among basins. The mean Jaccard's index increase (a measure of biotic homogenization) from the pristine situation to the present (17.1%) was similar to that for Californian fish but higher than for other studies. However, biotic homogenization was found to be a temporally dynamic process, with finer temporal grain analyses detecting transient stages of biotic differentiation. Introduced species assemblages were spatially structured along a latitudinal gradient in the Iberian Peninsula, with species related to sport fishing being characteristic of northern basins. Although the comparison of fish distributions in the Iberian Peninsula and France showed significant and generalized biotic homogenization, nonnative assemblages of northeastern Iberian basins were more similar to those of France than to those of the rest of the Iberian Peninsula, indicating a main introduction route. Species introduced to the Iberian Peninsula tended to be mainly piscivores or widely introduced species that previously had been introduced to France. Our results indicate that the simultaneous analysis of the spatial distribution of introduced assemblages (excluding native species that reflect other biogeographical patterns) and their specific traits can be an

  10. Habitat Selection and Foraging Behavior of Southern Elephant Seals in the Western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Huckstadt, L.; Costa, D. P.; McDonald, B. I.; Tremblay, Y.; Crocker, D. E.; Goebel, M. E.; Fedak, M. E.

    2006-12-01

    We examined the foraging behavior of 18 southern elephant seals foraging over two seasons in the Western Antarctic Peninsula. The foraging behavior and habitat utilization of 7 females in 2005 and 12 in 2006 were followed using satellite linked Satellite Relay Data Loggers that measured diving behavior as well collected salinity and temperature profiles as the animals dove. Animals were tagged after the annual molt during February at Cape Shirreff Livngston Island, South Shetland Islands. There was significant interannual variation in the regions of the Southern Ocean used by seals from Livingston Island. In 2005 of the 7 animals tagged one foraged 4700 km due west of the Antarctic Peninsula going as far as 150 W. The remaining females headed south along the Western Antarctic Peninsula bypassing Marguerite Bay moving south along Alexander Island. Three of these animals continued to forage in the pack ice as it developed. On their return trip all females swam past Livingston Island, continuing on to South Georgia Island where they apparently bred in the austral spring. One animal returned to Cape Shirreff to molt and her tag was recovered. During 2006 animals initially followed a similar migratory pattern going south along the Antarctic Peninsula, but unlike 2005 where the majority of the animals remained in the immediate vicinity of the Western Antarctic Peninsula, most of the animals in 2006 moved well to the west foraging as far as the Amundsen Sea. We compared the area restricted search (focal foraging areas) areas of these animals using a newly developed fractal landscape technique that identifies and quantifies areas of intensive search. The fractal analysis of area restricted search shows that the area, distance and coverage (Fractal D) searched were not different between years, while the time spent in the search areas was higher in 2005. Further analysis will examine how the physical properties of the water column as determined from the CTD data derived from

  11. Structural geology and tectonics of the Orville Coast region, southern Antarctic Peninsula, Antarctica

    SciTech Connect

    Kellogg, K.S.; Rowley, P.D.

    1989-01-01

    The oldest rocks in the Orville Coast of the southern Antarctic Peninsula and in adjacent parts of eastern Ellsworth Land belong to a Middle and Late Jurassic calc-alkalic magmatic arc that developed along the axial part of the peninsula. The main exposed product of the magmatism, which developed in response to eastward subduction beneath the Pacific margin of the peninsula, is mostly andesitic to dacitic volcanic rocks of the Mount Poster Formation. The Latady and Mount Poster Formations were strongly folded during Late Jurassic and (or) Early Cretaceous time during the Palmer Land deformational event. Fold axes are parallel to the prominent bend or orocline in the southern Antarctic Peninsula, and vergence is to the south or southeast. Thrust faults with apparently small displacement dip to the north or northwest in the Hauberg and Wilkins Mountains. Renewed arc magmatism, resulting in emplacement of gabbroic to granitic plutons of the Lassiter Coast Intrusive Suite, began before 115 Ma, sometime after folding ceased, and continued for at least 15 m.y. Dikes of similar composition to the plutonic rocks and anastomosing, randomly oriented, hydrothermal quartz veins were intruded during late stages of plutonism; copper mineralization associated with the late hydrothermal activity took place in the Sky-Hi Nunataks and Merrick Mountains. Small-displacement, predominantly right-lateral strike-slip faults, oriented about N. 70{degree}W., are probably satellitic to the right-lateral Ellsworth fault system. Drag along the Ellsworth fault system may account for clockwise-rotated paleomagnetic directions from Lower Cretaceous intrusive rocks in the Sweeney and Hauberg Mountains of the Orville Coast. The southern peninsula underwent deep erosion and peneplantation in the Late Cretaceous and early Tertiary, followed by gradual arching and rifting.

  12. Aerosol Optical Depth over Arabian Peninsula: a Validation of ECHAM5-HAM against Ground-Based and Satellite Data

    NASA Astrophysics Data System (ADS)

    Zawad, Faisal Al; Mamdouh, Khoder; Almazroui, Mansour; Alghamdi, Mansour

    2016-04-01

    This research validates aerosol optical depth (AOD) of the global climate - aerosol model (ECHAM5-HAM) for the period 2005 - 2011 over Arabian Peninsula. The ECHAM5-HAM AOD is evaluated at mid visible wavelength (550 nm) against AOD observation at three AERONET ground-base stations, and against satellite AOD measurements carried out by MODIS (Moderate Resolution Imaging Spectroradiometer). Average AOD monthly data for the period 2005 - 2011 is extracted from the model ECHAM5-HAM and compared to three AERONET stations located over Arabian Peninsula representing western (Hada Al-Sham), central (Solar Village) and eastern (Kuwait) regions. In addition, semillar comparison to MODIS AOD were carried out over all and over six sub-regions of Arabian Peninsula. The model overestimates the Angstrom Exponent by 0.69 and underestimate AOD by -0.15, but the model AOD is in a good correlation with observation (0.66) over Arabian Peninsula. This makes the model capable of predicting successfully the aerosol annual cycle over Arabian Peninsula. The ECHAM5-HAM model overestimates the Angstom Exponent and underestimates AOD over Arabian Peninsula, but it correlates well with observation. This implys that the model can be improved for regions dominated by dust, and can be effective in studying the various aspects of aerosol interactions in the atmosphere including investigating the direct and indirect enfluence of aerosols on the climate of Arabian Peninsula.

  13. Interseismic stress accumulation at the locked zone of Nankai Trough seismogenic fault off Kii Peninsula

    NASA Astrophysics Data System (ADS)

    Kinoshita, M.; Tobin, H. J.

    2011-12-01

    Since 2007, we accomplished drilling, coring and downhole measurements at 13 sites across the Nankai accretionary complex off Kii peninsula using D/V Chikyu. Although the deepest hole is well above the seismogenic fault zone, we found that the stress regime is quite variable across the accretionary prism, and their mechanism is still in discussion. An important source for such stress variation is the tectonic loading. In order to assess how much stress can possibly be accumulated around the locked zone during one seismic cycle, we conducted a simple 2D plain-strain steady-state elastic model using the finite-element method. We fixed the geometry of plate interface and prohibited a horizontal displacement at one side (above the plate interface) 200km landward from the trench. Along the plate interface except the locked zone, we allowed free slip only along the fault. The locked zone is defined at 30-100 km landward of the trench, and is assumed as 100% locked (no differential movement). The movement of downgoing lithosphere is given at the landward side boundary 200 km landward of the trench. Since we deal with the total stress accumulation within one seismic cycle, a displacement of 5 m was given as a slab pull. Young's modulus in the Kumano forearc basin (1 km thick) is set as 4 GPa taken from sonic log data at Site C0009, whereas that in the underlying domain is set at 50 GPa which would be too high for the accretionary sediment. In that case, estimated stress would be lower than provided below. Most of the tectonic stress due to 5m of plate convergence is concentrated near the downdip edge of the locked zone. The principal compressional and shear stress on the fault is larger than 5 MPa and 2 MPa, respectively. They roughly agree with the stress drop during the M8 events. These stresses along the fault, however, gradually decrease seaward to zero level. Tectonic compressional stress near the updip edge is much smaller than near downdip. At Site C0002, it is

  14. Radioecologycal study of {sup 239/240}Pu in Bangka Island and Muria Peninsula: Determination of {sup 239/240}Pu in marine sediment and seawater as part of baseline data collecting for sitting of candidates of first Indonesia NPP

    SciTech Connect

    Suseno, Heny; Wisnubroto, Djarot S.

    2014-03-24

    Radioisotope Pu-239/240 are alpha emitting nuclides important indicators of radioactive contamination of the marine environment. Global fallout is the main source of plutonium in the marine environment. There are very limited study on {sup 239/240}Pu in Indonesia coastal environments. The data of this radioisotopes is needed for baseline data of nuclear power plant (NPP) site candidates both in Bangka Island and Muria Peninsula. Bottom sediments play an important role in radioecological studies of the marine environment because a large proportion of radioactive substances entering the sea is adsorbed over time onto suspended particulate matter and deposited in sediments. Plutonium is particle reactive and deposited in marine sediment. Radioisotope {sup 239/240}Pu was determinated by alpha spectrometry after radiochemical procedure that was performed in both water and marine sediment from Bangka Island and Muria Peninsula. The sediment baseline of concentration {sup 239/240}Pu in Bangka Island and Muria Peninsula were range from 0.013 to 0.021 Bq.kg{sup −1} and 0.018 to 0.024 Bq.kg{sup −1} respectively. The water baseline concentration this isotope were range from 2.73 to 4.05 mBq.m{sup −3} and 2.98 to 4.50 mBq.m{sup −3}.

  15. Spectral Characteristics of Vegetation Functional Traits across a Range of Thaw Gradients on Alaska's Seward Peninsula

    NASA Astrophysics Data System (ADS)

    Goswami, S.; Hayes, D. J.; Sloan, V. L.; Liebig, J. A.; Norby, R. J.; Wullschleger, S. D.

    2014-12-01

    The Arctic and Boreal regions are warming rapidly, leading to the thawing of the underlying permafrost and associated changes in vegetation structure and composition. The thawing of ice-rich permafrost drives land surface dynamics called thermokarst, characterized by a variety of geomorphic surface features across high latitude landscapes. The development of these thermokarst or thermo-erosional features depends on factors such as local permafrost conditions, hydrology, geomorphology, vegetation, and climate, but their degree of dependence are not well understood across scales. The structure, functions and traits of the vegetation can work as effective indicators of these landscape changes. Our ability to characterize these vegetation characteristics across a wide range of thaw gradients at the local scale could help us to better understand the dependency as well as the impacts of thermokarst processes on them. This will also help us to develop capabilities to quantify these characteristics and dependencies from local to regional scales by using remote sensing and ecosystem modeling techniques. During the months of June - July of 2013 and 2014, we conducted field surveys at various sites across the central Seward Peninsula in Alaska covering a range of thaw gradients to collect data for vegetation functional traits, ancillary data and also hyperspectral data in the 400-2500 nm range using a field spectrometer. Data were collected from plots established along 50 m transects to capture transitional states of these thaw features from the upland zone, transition zone, and thaw lake basins as well as in polygonal features. Here we discuss the characteristics of vegetation functional traits and how they relate to the ground-based spectral measurements. Some of these findings could be scaled up using airborne and satellite remote sensing data. The findings from this study can improve our understanding of disturbance patterns and their feedbacks to local scale plant and

  16. Landscape-scale habitat selection by fishers translocated to the Olympic Peninsula of Washington

    USGS Publications Warehouse

    Lewis, Jeffrey C.; Jenkins, Kurt J.; Happe, Patricia J.; Manson, David J.; McCalmon, Marc

    2016-01-01

    The fisher was extirpated from much of the Pacific Northwestern United States during the mid- to late-1900s and is now proposed for federal listing as a threatened species in all or part of its west coast range. Following the translocation of 90 fishers from central British Columbia, Canada, to the Olympic Peninsula of Washington State from 2008 to 2010, we investigated the landscape-scale habitat selection of reintroduced fishers across a broad range of forest ages and disturbance histories, providing the first information on habitat relationships of newly reintroduced fishers in coastal coniferous forests in the Pacific Northwest. We developed 17 a priori models to evaluate several habitat-selection hypotheses based on premises of habitat models used to forecast habitat suitability for the reintroduced population. Further, we hypothesized that female fishers, because of their smaller body size than males, greater vulnerability to predation, and specific reproductive requirements, would be more selective than males for mid- to late-seral forest communities, where complex forest structural elements provide secure foraging, resting, and denning sites. We assessed 11 forest structure and landscape characteristics within the home range core-areas used by 19 females and 12 males and within randomly placed pseudo core areas that represented available habitats. We used case-controlled logistic regression to compare the characteristics of used and pseudo core areas and to assess selection by male and female fishers. Females were more selective of core area placement than males. Fifteen of 19 females (79%) and 5 of 12 males (42%) selected core areas within federal lands that encompassed primarily forests with an overstory of mid-sized or large trees. Male fishers exhibited only weak selection for core areas dominated by forests with an overstory of small trees, primarily on land managed for timber production or at high elevations. The amount of natural open area best

  17. Developmental History of an Intriguing Peat-Forming Community Along the West Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Loisel, J.; Yu, Z.; Beilman, D.; Kaiser, K.

    2014-12-01

    Permafrost peatbanks along the West Antarctic Peninsula (WAP) have become valuable high-resolution archives for late-Holocene climatic conditions recently. We recently observed and studied a few water-saturated peatlands that had formed in rocky depressions near Vernadsky Station and in mainland Antarctica (~ 65°S, 64°W). Remarkably, we seem to be the very first ones to analyze these systems for environmental reconstructions. The similarity between these peatlands and fens from the lower latitudes is striking, and the rarity of these systems along the WAP is intriguing. We present a high-resolution, multi-proxy record of ecosystem development and paleoenvironmental conditions for Rasmussen peatland. The ecosystem is ~100 m2 in size and is characterized by a shallow water table depth at 7 cm below the surface. Surface vegetation is dominated by Calliergon spp., a wet-adapted moss found along the WAP. The studied moss deposit is 50 cm thick and has a high organic matter content (> 90% dry weight). Plant macrofossil analysis reveals that the peatland was initially a wet Sanionia spp. carpet and that a sharp transition to Calliergon spp. occurred about half way through the deposit. A distinct layer of highly decomposed organic matter was observed from 32 to 40 cm and could indicate a period of slowed peat formation, potentially due to dry conditions (enhanced peat decay) or perennial snow cover (limited plant growth). Biochemical decomposition indicators such as carbohydrate yields, acid:aldehyde ratios of lignin phenols, and hydroxyproline yields are being determined to better understand the extent of peat decay that has occurred at this site throughout its development, particularly to further address the nature of the observed stratigraphic changes. Preliminary results indicate that carbohydrate yields of the bottom half of the core are about 1/3 smaller than those of the top half, indicating substantial carbon loss due to decomposition. Overall, these peatlands

  18. Geomorphological characteristics of Yedoma terrains in the northern part of Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Stephani, E.; Dillon, M.; Fortier, D.; Jorgenson, T.; Kanevskiy, M. Z.; Shur, Y.

    2009-12-01

    Yedoma (Ice Complex) is a Late Pleistocene periglacial formation of syngenetic permafrost with large ice wedges. These extremely ice-rich stratigraphic sequences have been widely observed and studied in northern Siberia. However, very few studies have focused on Yedoma terrain in Northern America. Occurrence of Yedoma landscape has a great significance for paleoenvironmental reconstructions because the regions where Yedoma can be observed remained unglaciated during the late Pleistocene. Understanding the dynamics of Yedoma landscape and the geotechnical properties of this permafrost unit is necessary for modeling the evolution of the periglacial landscape in the context of climate change. Degradation of Yedoma terrain triggers several geomorphological processes such as thaw settlement due to deepening of the active layer, development of thermokarst lakes, thermo-erosion gullies, and active layer detachment slides. Degradation of yedoma terrain also releases greenhouse gases (e.g. methane, CO2), water from melting ice, and various types of mineral and organic sediments which need to be accounted for in climate warming scenarios. Yedoma terrains in their contemporary state can be identified by the presence of typical geomorphological features such as erosional remnants with specific shape, baidjarakhs (ground mounds formed as a result of wedge-ice thawing), abundance of thermokarst lakes, drained lakes basins, low-gradient streams and erosion-thermokarst valleys (alas valleys) with occasional pingos. We have studied and characterized in the field the metrics of two Yedoma sites at the northern part of Seward Peninsula. Geomorphic sub-units such as drained lake basins and Yedoma remnants have been characterized in detail via optical leveling surveys. Bathymetry of thermokarst lakes was measured by lake-based sonar and GPS surveys. Drilling was conducted in several locations along the survey transects. The cores retrieved were described in the field in terms of

  19. Deposition, Diagenetic, or Bacterial Origin of Magnetite in Sediment Drifts From the Western Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Dulgar, S. E.; Brachfeld, S.; Ishman, S.; Ferré, E. C.

    2007-05-01

    A 607 meter sediment core from the western Antarctic Peninsula was collected during Ocean Drilling Program (ODP) Leg 178 at Site 1096. An abrupt shift, first recognized during the construction of the geomagnetic reversal stratigraphy, is observed in the magnetic mineral assemblage in core 1096A at 18 meters below seafloor (mbsf). This magnetic shift led us to question the fidelity of the geomagnetic reversal record. We evaluated the magnetic mineral assemblage using rock magnetic and electron microscopy techniques. Magnetic susceptibility showed variable concentration of magnetic material with depth, but not an abrupt change in concentration at 18 mbsf. Hysteresis data reveal a grain size shift at 18 mbsf. Magnetic particle size measurements show that with increasing depth the magnetic grain size increases. One possible explanation for the grain size shift is the presence of bacterial magnetite above 18 mbsf. However, TEM analysis did not conclusively prove the presence of magnetosomes. TEM images show grains in the 20-60 nm size range, but these grains were not in chains and they do not have the typical morphologies associated with bacterial magnetite. It is possible that these ultra fine grains are authigenic. Dissolution of these ultra fine magnetic particles could cause the grain size shift, with the smaller grains dissolving below18 mbsf. Temperature dependent FORC analyses are in progress to further characterize the particle size distribution above and below 18 mbsf. Curie temperature analyses indicate that magnetite is present above and below 18 mbsf. A magnetic iron sulfide with a Curie temperature of 350° C is present above 18 mbsf. X-ray microanalysis results agree with Curie temperature analyses, and show the presence of both Ti-poor iron oxides and iron sulfides in the magnetic extract. The presence of magnetic iron sulfides above 18 mbsf suggests iron-sulfur diagenesis is occurring with pyrrhotite preserved above 18 mbsf, and non-magnetic pyrite

  20. Diagnostic modeling of dimethylsulfide production in coastal water west of the Antarctic Peninsula

    NASA Technical Reports Server (NTRS)

    Hermann, Maria; Najjar, Raymond G.; Neeley, Aimee R.; Vila-Costa, Maria; Dacey, John W. H.; DiTullio, Giacomo, R.; Kieber, David J.; Kiene, Ronald P.; Matrai, Patricia A.; Simo, Rafel; Vernet, Maria

    2012-01-01

    The rate of gross biological dimethylsulfide (DMS) production at two coastal sites west of the Antarctic Peninsula, off Anvers Island, near Palmer Station, was estimated using a diagnostic approach that combined field measurements from 1 January 2006 through 1 March 2006 and a one-dimensional physical model of ocean mixing. The average DMS production rate in the upper water column (0-60 m) was estimated to be 3.1 +/- 0.6 nM/d at station B (closer to shore) and 2.7 +/- 0.6 nM/d1 at station E (further from shore). The estimated DMS replacement time was on the order of 1 d at both stations. DMS production was greater in the mixed layer than it was below the mixed layer. The average DMS production normalized to chlorophyll was 0.5 +/- nM/d)/(mg cubic m) at station B and 0.7 +/- 0.2 (nM/d)/(mg/cubic m3) at station E. When the diagnosed production rates were normalized to the observed concentrations of total dimethylsulfoniopropionate (DMSPt, the biogenic precursor of DMS), we found a remarkable similarity between our estimates at stations B and E (0.06 +/- 0.02 and 0.04 +/- 0.01 (nM DMS / d1)/(nM DMSP), respectively) and the results obtained in a previous study from a contrasting biogeochemical environment in the North Atlantic subtropical gyre (0.047 =/- 0.006 and 0.087 +/- 0.014 (nM DMS d1)/(nM DMSP) in a cyclonic and anticyclonic eddy, respectively).We propose that gross biological DMS production normalized to DMSPt might be relatively independent of the biogeochemical environment, and place our average estimate at 0.06 +/- 0.01 (nM DMS / d)/(nM DMSPt). The significance of this finding is that it can provide a means to use DMSPt measurements to extrapolate gross biological DMS production, which is extremely difficult to measure experimentally under realistic in situ conditions.

  1. Hydrological conditions determine branched glycerol dialkyl glycerol tetraether distributions in soils of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Huguet, Carme; Menges, Johanna; Fietz, Susanne; Sachse, Dirk; Rosell-Melé, Antoni

    2013-04-01

    Temperature is one of the key environmental factors driving climate change, but past continental temperature records are constrained by the few proxies that can be applied in these environments. The MBT-CBT proxy is based on the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGTs), bacterial membrane lipids in soils1.Since the degree of cyclisation of the GDGTs (CBT) was found to corellate to soil pH, while tindex degree of methylation (MBT) corellates to mean annual temperature and soil pH. a combination of these two indices allows the estimation of mean annual temperature (MAT). However, it has been suggested, that other factors such as the hydrological conditions can also influence the MBT2, although it has never been testet directly. To asses the effect of hydrological conditions on the MBT-CBT a set of 25 soil samples of the Iberian Peninsula covering a temperature range from 10-18°C and a wide range of hydrological regimes was analysed (405 mm to 1455 mm per year) . We found that CBT was significantly correlated to soil pH confirming it even at a regional scale as a robust proxy for soil pH. The MBT was also shown to relate to soil pH, but the the expected relation between MBT and MAT could not be established. In fact, the correlation between MBT and MAT was inverse to the one expected according to previous studies and presented large scatter (R2=0,2). Consequently the MAT estimation using the MBT-CBT proxy leads to an underestimation of MAT, which is most prominent at the dryest sites and reaches up to 24°C. Instead we found a significant correlation between MBT and annual mean precipitation as well as the Aridity Index (AI)3, a parameter quantifying water availability in soils. This suggests that in dry environments or under moisture shortage the influence of the degree of methylation of branched GDGTs is not coupled to temperature but to the degree of water availability. 1. Weijers, J.W.H. et al. 2007. GCA. 71, 703-713. 2. Peterse, F

  2. Constraints on in situ stress across the shallow megasplay fault offshore the Kii Peninsula, SW Japan from borehole breakouts

    NASA Astrophysics Data System (ADS)

    Olcott, K. A.; Saffer, D. M.

    2012-12-01

    The orientation and magnitude of stress in active tectonic settings, and in the vicinity of active faults, are important toward understanding faulting and earthquake mechanics. In areas where boreholes have been drilled, stress magnitude can be quantified by combining observations of compressional borehole breakout (BO) widths with estimates or measurements of unconfined compressive rock strength (UCS). Here, we estimate stress at Integrated Ocean Drilling Program (IODP) Sites C0004 and Site C0010, drilled into the accretionary prism offshore the Kii Peninsula, SW Japan, as part of the IODP NanTroSEIZE project. These sites penetrated the shallow portion of the megasplay fault, a major out of sequence thrust fault that cuts the accretionary prism and branches from the master décollement ~55 km from the trench. Drilling at Site C0004 included logging while drilling (LWD) and coring to a total depth (TD) of ~399 m. Drilling at Site C0010, located ~3.5 km along strike, included LWD to a TD of 555 mbsf. The megasplay fault is marked by a 60-m wide fractured zone at Site C0004, whereas at Site C0010 it is defined by a sharp contact between the overriding thrust wedge and footwall sediments. At Site C0010, the hole was temporarily suspended for 3 days due to weather conditions, and ~70 m of the hanging wall and the upper portion of the footwall were relogged after re-entry and prior to continued drilling. We measure BO width from LWD resistivity-at-the-bit (RAB) images, and estimate a range of UCS values from existing experimentally-derived relations between P-wave velocity (Vp) and UCS. Under the assumption that stresses at the edge of BO are in equilibrium with the rock strength, we quantify far field horizontal stresses SHmax and Shmin as a function of depth at each drillsite. Our results indicate that stresses at both Site C0004 and Site C0010 define a thrust-faulting regime, in both the hanging wall and footwall of the fault. This implies that stress is not

  3. Population structure and range expansion: the case of the invasive gastropod Cyclope neritea in northwest Iberian Peninsula.

    PubMed

    Couceiro, Lucía; López, Lúa; Ruiz, José Miguel; Barreiro, Rodolfo

    2012-09-01

    Biotic invasions have a reputation for unpredictable behavior. Here, we report how slight changes in human activity responsible for the introduction and range expansion of a non-native mollusk have led to detectable differences in the genetics of the invasion. Cyclope neritea is a non-predatory gastropod introduced to 2 areas of the European Atlantic: the northwest Iberian Peninsula (NWIP) and the French Atlantic coast (FAC). Shellfish seabed farming is intense in both areas but focuses on different commercial species. Using mitochondrial gene sequences, the lower genetic diversity recorded along the NWIP suggests a more homogeneous range of source populations than in the FAC. Unlike FAC, genetic diversity and haplotype composition in the NWIP correlate with the date of first occurrence of C. neritea at each site rather than with geographical location. Although this pattern evokes the genetic signature expected under a serial-founder colonization model from a single initial enclave, a comparison with samples from potential source populations suggests that the NWIP probably experienced several independent reintroductions. The jump dispersal pattern of C. neritea in the NWIP, together with the observation that populations established in the same year are genetically undifferentiated, point to human transport as the most plausible explanation for the current range expansion. Despite evidence for human-mediated dispersal, C. neritea managed to develop a seemingly non-random genetic pattern in the NWIP. It is suggested that caution must be exerted when interpreting genetic patterns in invaders.

  4. Autumn migration and wintering areas of Peregrine Falcons Falco peregrinus nesting on the Kola Peninsula, northern Russia

    USGS Publications Warehouse

    Ganusevich, S.A.; Maechtle, T.L.; Seegar, W.S.; Yates, M.A.; McGrady, M.J.; Fuller, M.; Schueck, L.; Dayton, J.; Henny, C.J.

    2004-01-01

    Four female Peregrine Falcons Falco peregrinus breeding on the Kola Peninsula, Russia, were fitted with satellite-received transmitters in 1994. Their breeding home ranges averaged 1175 (sd = ??714) km2, and overlapped considerably. All left their breeding grounds in September and migrated generally south-west along the Baltic Sea. The mean travel rate for three falcons was 190 km/day. Two Falcons wintered on the coasts of France and in southern Spain, which were, respectively, 2909 and 4262 km from their breeding sites. Data on migration routes suggested that Falcons took a near-direct route to the wintering areas. No prolonged stopovers were apparent. The 90% minimum convex polygon winter range of a bird that migrated to Spain encompassed 213 km2 (n = 54). The area of the 50% minimum convex polygon was 21.5 km2 (n = 29). Data from this study agree with others from North America that show that Falcons breeding in a single area do not necessarily follow the same migratory path southward and do not necessarily use the same wintering grounds.

  5. Acrostichum, a Pioneering Fern of Floodplain Areas from the Late Oligocene Sariñena Formation of the Iberian Peninsula

    PubMed Central

    Ferrer, Javier; Diez, José B.

    2016-01-01

    Acrostichum is considered today an opportunistic fern in disturbed areas, which indicates the first stages of colonisation of such zones. However, in the fossil record, Acrostichum appears related to fluvio-lacustrine environments, freshwater marshes and mangrove deposits. We report here for first time fossil evidence of Acrostichum that reveals a pioneering behaviour of this fern in the colonisation of perturbed communities in Europe, which corroborates previous assumptions about the paleobiology of Acrostichum. Plant remains were collected from the Chattian (late Oligocene) La Val fossil site (Estadilla, Huesca, northeastern Spain) belonging to the Sariñena Formation, which mainly embraces crevasse splays, levees and floodplain deposits. Evidence shows that Acrostichum grew within the levee’s vegetal community or close to/on the river banks as well as on floodplain areas and closer to/on the shores of ephemeral ponds. But most importantly, the observed co-existence of Equisetum and Acrostichum remains in the same beds indicates that such strata represent short-lived inundated terrains, e.g., floodplains where the water table was temporarily stagnant. Evidence shows wetland environments dominated by pioneering taxa, implying a pioneering role for Acrostichum during the late Oligocene in the Iberian Peninsula. PMID:27631099

  6. Acrostichum, a Pioneering Fern of Floodplain Areas from the Late Oligocene Sariñena Formation of the Iberian Peninsula.

    PubMed

    Moreno-Domínguez, Rafael; Cascales-Miñana, Borja; Ferrer, Javier; Diez, José B

    2016-01-01

    Acrostichum is considered today an opportunistic fern in disturbed areas, which indicates the first stages of colonisation of such zones. However, in the fossil record, Acrostichum appears related to fluvio-lacustrine environments, freshwater marshes and mangrove deposits. We report here for first time fossil evidence of Acrostichum that reveals a pioneering behaviour of this fern in the colonisation of perturbed communities in Europe, which corroborates previous assumptions about the paleobiology of Acrostichum. Plant remains were collected from the Chattian (late Oligocene) La Val fossil site (Estadilla, Huesca, northeastern Spain) belonging to the Sariñena Formation, which mainly embraces crevasse splays, levees and floodplain deposits. Evidence shows that Acrostichum grew within the levee's vegetal community or close to/on the river banks as well as on floodplain areas and closer to/on the shores of ephemeral ponds. But most importantly, the observed co-existence of Equisetum and Acrostichum remains in the same beds indicates that such strata represent short-lived inundated terrains, e.g., floodplains where the water table was temporarily stagnant. Evidence shows wetland environments dominated by pioneering taxa, implying a pioneering role for Acrostichum during the late Oligocene in the Iberian Peninsula. PMID:27631099

  7. Environmental impact assessment of the mining and concentration activities in the Kola Peninsula, Russia by multidate remote sensing.

    PubMed

    Rigina, Olga

    2002-04-01

    On the Kola Peninsula, the mining and concentration industry exerts anthropogenic impact on the environment. Tailing dumps cause airborne pollution through dusting, and waterborne pollution due to direct dumping and accidental releases. The objectives were: (1) to analyse multidate satellite images for 1964-1996 to assess the environmental pollution from the mining and concentration activity in the Kola in temporal perspective; (2) to evaluate remote sensing methods for integrated environmental impact assessment. The area of mining and industrial sites steadily expands and amounted to 94 km2 in 1996. The polluted water surface amounted to at least 150 km2 through dumping in 1978 and to 106 km2 in 1986 due to dusting. Thus, the impact from the mining and concentration activity should be reconsidered as more significant than it was officially anticipated. In the past the main mechanism of pollution was direct dumping into the lakes. Currently and in future, airborne pollution after dusting storms will dominate. The effective recultivation of the tailing dumps will be a long-term process. For effective assessment of impacts from the mining and concentration industry, remote sensing methods should be complemented by in-situ measurements, fieldwork, and mathematical modelling. PMID:15900663

  8. Heavy carbon travertine related to methane generation: A case study of the Big Tarkhan cold spring, Kerch Peninsula, Crimea

    NASA Astrophysics Data System (ADS)

    Kokh, Svetlana N.; Shnyukov, Yevgeny F.; Sokol, Ella V.; Novikova, Sofya A.; Kozmenko, Olga A.; Semenova, Dina V.; Rybak, Elena N.

    2015-07-01

    The Big Tarkhan cold spring is located within the Bulganak zone of mud volcanism in the northern Kerch Peninsula (Crimea). The spring waters mainly have Cl-HCO3-Na-Ca chemistry and temperatures from 18 to 23 °C. Active travertine deposition at the site produces abundant calcite and minor amounts of siderite, halite, tincalconite, trona, gaylussite, northupite and amorphous iron hydroxides. Calcite contains the impurities of 0.26-2.16 wt.% MgO, up to 0.87 wt.% FeO, 0.15-0.73 wt.% SrO, 0.28-0.98 BaO, up to 0.43 wt.% MnO, and 0.09-0.60 Na2O. Active travertines are depleted in REE (ΣREE = 2.6-4.8 ppm) compared to the inactive ones. The Kerch travertine calcite shows unusual carbon and oxygen isotope compositions (+ 8.1 ÷ + 12.5‰ VPDB δ13C and + 10.1 ÷ + 12.9‰ VPDB δ18O). Their isotopic and trace element signatures (including REE patterns) suggest their relation to basinal waters and origin from the organic-rich clayey Maikop Fm., which is the principal source rock of the area. The Big Tarkhan travertine deposits are associated with thermogenic methane production.

  9. Hydrologic landscapes on the Delmarva Peninsula - Part 2: Estimates of base-flow nitrogen load to Chesapeake Bay

    USGS Publications Warehouse

    Joseph, Bachman L.; Phillips, P.J.

    1996-01-01

    Base-flow samples were collected from 47 sampling sites for four seasons from 1990-91 on the Delmarva Peninsula in Delaware and Maryland to relate stream chemistry to a "hydrologic landscape" and season. Two hydrologic landscapes were determined: (1) a well-drained landscape, characterized by a combination of a low percentage of forest cover, a low percentage of poorly drained soil, and elevated channel slope; and (2) poorly drained landscape, characterized by a combination of an elevated percentage of forest cover, an elevated percentage of poorly drained soil, and low channel slope. Concentrations of nitrogen were significantly related to the hydrologic landscape. Nitrogen concentrations tended to be higher in well-drained landscapes than in poorly drained ones. The highest instantaneous nitrogen yields occurred in well-drained landscapes during the winter. These yields were extrapolated over the part of the study area draining to Chesapeake Bay in order to provide a rough estimate of nitrogen load from base flow to the Bay and its estuarine tributaries. This estimate was compared to an estimate made by extrapolating from an existing long-term monitoring station. The load estimate from the stream survey data was 5 ?? 106 kg of N per year, which was about four times the estimate made from the existing long-term monitoring station. The stream-survey estimate of base flow represents about 40 percent of the total nitrogen load that enters the Bay and estuarine tributaries from all sources in the study area.

  10. The role of organic ligands in iron cycling and primary productivity in the Antarctic Peninsula: A modeling study

    NASA Astrophysics Data System (ADS)

    Jiang, Mingshun; Barbeau, Katherine A.; Selph, Karen E.; Measures, Christopher I.; Buck, Kristen N.; Azam, Farooq; Greg Mitchell, B.; Zhou, Meng

    2013-06-01

    Iron (Fe) is the limiting nutrient for primary productivity in the Southern Ocean, with much of the dissolved iron (dFe) bound to organic ligands or colloids. A Fe model for the Southern Ocean (SOFe) is developed to understand the role of bacteria and organic ligands in controlling Fe cycling and productivity. The model resolves the classical food web and microbial loop, including three types of nutrients (N, Si, Fe) and two types of Fe ligands. Simulations of the zero-dimensional (0-D) model are calibrated with detailed results of shipboard grow-out incubation experiments conducted with Antarctic Peninsula phytoplankton communities during winter 2006 to provide the best estimate of key biological parameters. Then a one-dimensional (1-D) model is developed by coupling the biological model with the Regional Oceanic Modeling System (ROMS) for a site on the Antarctic Peninsula shelf, and the model parameters are further calibrated with data collected from two surveys (summer 2004 and winter 2006) in the area. The results of the numerical simulations agree reasonably well with observations. An analysis of the 1-D model results suggests that bacteria and organic ligands may play an important role in Fe cycling, which can be categorized into a relatively fast mode within the euphotic zone dominated by photo-reactions (summer d Fe residence time about 600 days) and complexation and a slow mode below with most of the dFe biologically complexed (summer dFe residence time >10 years). The dFe removal from the euphotic zone is dominated by colloidal formation and further aggregations with additional contribution from biological uptake, and an increase of organic ligands would reduce Fe export. The decrease of Fe removal rate over depth is due to the continuous dissolution and remineralization of particulate Fe. A number of sensitivity experiments are carried out for both 0-D and 1-D models to understand the importance of photo-reactive processes in primary productivity

  11. A quantitative analysis of grid nudging effect on each process of PM2.5 production in the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Jeon, Wonbae; Choi, Yunsoo; Lee, Hwa Woon; Lee, Soon-Hwan; Yoo, Jung-Woo; Park, Jaehyeong; Lee, Hyo-Jung

    2015-12-01

    This study investigated the effect of assimilated meteorological fields on simulated PM2.5 concentrations in the Korean Peninsula. Two different CMAQ simulations were conducted using base WRF run (BASE) and grid-nudged WRF run (GNG) which included a simple data assimilation method for the time period of April, 2009. The simulated PM2.5 and PM10 concentrations were compared with corresponding observations. The BASE PM2.5 concentrations were significantly underestimated at Anmyeondo (AMD) and six Air Quality Monitoring Station (AQMS) sites in Korea, but GNG showed improved agreement with in-situ measurements due to the effect of grid nudging. The grid nudging effect was dominant under the PBL height and it appeared more clearly under the unstable synoptic condition (April 5-8) than stable condition (April 9-13). Additional quantitative analysis was conducted using the Integrated Process Rate (IPR) in the CMAQ model to investigate the effect of varied meteorological fields on each PM2.5 production and destruction processes. The PM2.5 production rate by aerosol process in GNG was shown to be higher than that of BASE, especially near the source region (e.g., Eastern China). The increased temperature and decreased wind speed by grid nudging effect led to increase of aerosol production rates especially during the nighttime. The change of aerosol production rates were mainly caused by increased sulfate (SO42-) and nitrate (NO3-) production rates in the day and nighttime respectively. Also, GNG provides higher PM2.5 transport rates than BASE over the whole domain. The amount of PM2.5 scavenged by wet deposition process in GNG was smaller than that of BASE over the Yellow Sea, reflecting the decreased water vapor mixing ratio by grid nudging. Thus, it resulted in the increase of simulated PM2.5 concentrations. The results indicated that understanding the effects of grid nudging on PM2.5 concentrations is crucial to enhance the performance of PM2.5 modeling

  12. Geochemical survey of medium temperature geothermal resources from the Baja California Peninsula and Sonora, México

    NASA Astrophysics Data System (ADS)

    Barragán R, R. M.; Birkle, P.; Portugal M, E.; Arellano G, V. M.; Alvarez R, J.

    2001-09-01

    Waters from hot springs and deep wells from Cerritos in the northern Baja California Peninsula and deep wells from the Riı´to zone (Sonora state) were studied in order to classify medium temperature geothermal resources to be exploited in NW-Mexico. Geochemical characteristics of San Felipe and Punta Estrella coastal springs indicate the mixing of seawater and meteoric components with secondary leaching of evaporates. Reservoir temperatures for both zones were estimated up to 225°C. Mixing of high portions of seawater (>80 wt%) with local waters could be the origin for the Puertecitos coastal spring, with a reservoir temperature estimation of 195°C. The El Coloradito coastal spring is composed of meteoric water with a reservoir temperature of 127°C. The formation of thermal manifestations along the Baja California coast could be related to the heating up of convecting seawater along extensional tectonic structures, as observed for submarine hydrothermal vents at the Gulf of California and along the East Pacific Rise. Volcanic steam-heated waters with a reservoir temperature of 135°C were found at the Valle Chico inland springs from the Baja California Peninsula. Deep fluids from the Riı´to zone originated by evaporation of infiltrated waters with similar characteristics to those located in the Mexicali Valley. Reservoir temperature of 192 and 126°C are estimated for the Riı´to deep wells ER-1B (ER) and R-1, respectively. The Riı´to artesian wells M-1, M-2 and M-4 indicate reservoir temperatures from 109 to 118°C. Isotopic data define the artesian wells as typical surface water or shallow groundwater from the Mexicali Valley. The Cerritos deep fluids of the Mexicali Valley show a close chemical and isotopic relationship to the adjacent Cerro Prieto reservoir fluids suggesting a similar origin and a possible connection of both aquifer systems. Conductive cooling of Cerro Prieto discharge fluids could originate the cooler Cerritos system (130

  13. Geophysical evidence for Quaternary deformation within the offshore San Andreas Fault System, Point Reyes Peninsula, California

    NASA Astrophysics Data System (ADS)

    Stozek, B.

    2010-12-01

    Our previous work studying the rate and style of uplift of marine terraces on the Point Reyes Peninsula indicates the peninsula has been undergoing differential uplift due to interacting fault geometries in the offshore zone. To better understand offshore fault interactions, recently collected mini-sparker seismic reflection data acquired by the USGS and multi-beam bathymetric data acquired by California State University at Monterey Bay within the 3-mile (5 km) limit offshore of the Point Reyes Peninsula, are being used to reinterpret the tectono-stratigraphic framework of the San Andreas fault (SAF) system. Eight offshore Shell exploratory well logs that provide seismic velocity and paleontologic data are being used in conjunction with industry multichannel (deep-penetration) seismic reflection profiles to provide age control and extend the analyses beyond 3 mile limit of the high-resolution data. Isopach and structure maps of key stratigraphic intervals were generated to show how the stratigraphic units are influenced by fault interactions. These datasets allow for new interpretations of the offshore Neogene stratigraphy and the evolution of the Point Reyes fault, an offshore component of the SAF system. Observations of Quaternary sedimentary sequences in the high-resolution mini-sparker dataset provide evidence of localized areas of subsidence and uplift within the offshore SAF system. For example, the most recent angular unconformity above the Point Reyes fault deepens to the north where the fault bends from an east-west to a more northerly orientation. Stratigraphic horizons in the offshore zone are correlated with the same geologic units exposed on the Point Reyes Peninsula. Both unconformity-bounded sedimentary sequences mapped on reflection profiles in the offshore and marine terraces that have been uplifted on the peninsula are tied to sea-level fluctuations. Our new interpretation of the Point Reyes fault zone will be incorporated into a kinematic fault

  14. Morphotectonic Index Analysis as an Indicator of Neotectonic Segmentation of the Nicoya Peninsula, Costa Rica

    NASA Astrophysics Data System (ADS)

    Morrish, S.; Marshall, J. S.

    2013-12-01

    The Nicoya Peninsula lies within the Costa Rican forearc where the Cocos plate subducts under the Caribbean plate at ~8.5 cm/yr. Rapid plate convergence produces frequent large earthquakes (~50yr recurrence interval) and pronounced crustal deformation (0.1-2.0m/ky uplift). Seven uplifted segments have been identified in previous studies using broad geomorphic surfaces (Hare & Gardner 1984) and late Quaternary marine terraces (Marshall et al. 2010). These surfaces suggest long term net uplift and segmentation of the peninsula in response to contrasting domains of subducting seafloor (EPR, CNS-1, CNS-2). In this study, newer 10m contour digital topographic data (CENIGA- Terra Project) will be used to characterize and delineate this segmentation using morphotectonic analysis of drainage basins and correlation of fluvial terrace/ geomorphic surface elevations. The peninsula has six primary watersheds which drain into the Pacific Ocean; the Río Andamojo, Río Tabaco, Río Nosara, Río Ora, Río Bongo, and Río Ario which range in area from 200 km2 to 350 km2. The trunk rivers follow major lineaments that define morphotectonic segment boundaries and in turn their drainage basins are bisected by them. Morphometric analysis of the lower (1st and 2nd) order drainage basins will provide insight into segmented tectonic uplift and deformation by comparing values of drainage basin asymmetry, stream length gradient, and hypsometry with respect to margin segmentation and subducting seafloor domain. A general geomorphic analysis will be conducted alongside the morphometric analysis to map previously recognized (Morrish et al. 2010) but poorly characterized late Quaternary fluvial terraces. Stream capture and drainage divide migration are common processes throughout the peninsula in response to the ongoing deformation. Identification and characterization of basin piracy throughout the peninsula will provide insight into the history of landscape evolution in response to

  15. Pathway of the Fukushima radioactive plume for reaching the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Lozano, R.; Hernández-Ceballos, M. A.; Adame, J. A.; Casas-Ruíz, M.; Sorribas, M.; San Miguel, E. G.; Bolívar, J. P.

    2012-04-01

    Activity concentrations of several man-made radionuclides (such as 131I, 132I, 132Te, 134Cs and 137Cs) were detected along the Iberian Peninsula from March 28th to April 7th 2011, including the sampling stations, "El Carmen", located at the Campus of the University of Huelva (37.28° N, 6.91° W) (Southwest Spain). The highest activity concentrations of fission products were obtained on 28th March. After this date, the activity concentrations decreased and remained approximately constant during the following days until reaching values below detection limits. The study of the air masses by the computation of backward trajectories using the HYSPLIT model allowed to demonstrate that these radionuclide activity concentrations were derived of the atmospheric radionuclide releases from the accident produced in the nuclear power plant of Fukushima (Japan), occurred on March 11th, 2011, after an earthquake happened in the Pacific Ocean (9 degrees on the Richter Scale). Hourly Kinematic 3D-backward trajectories with a duration of eight days and at three different heights were calculated at 500 m, 1000 m and 1500 m over Huelva city (37.28° N, 6.91° W) from 26th March to 6th April, and at Washington DC (38.89° N, 77.02° W) from 18th to 29th March to check the connection between the air flows from the Pacific Ocean, east coast of North America, where activity concentrations were previously measured by E.P.A, and Iberian Peninsula. By connecting the results obtained, a wind corridor from the Bering Sea to the Iberian Peninsula was observed in 27th-29th March, coinciding with the maximum of concentrations measured in the south-western Iberian Peninsula. After these days, the progressive change in the dynamics of air masses over the east coast of North America tended to break this wind channelling, despite the continuous arrival of westerly flow over the southwest of the Iberian Peninsula. This change happened in the same dates that a progressive decreasing in the

  16. Characteristics of storms that contribute to extreme precipitation events over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Trigo, Ricardo; Ramos, Alexandre M.; Ordoñez, Paulina; Liberato, Margarida L. R.; Trigo, Isabel F.

    2014-05-01

    Floods correspond to one of the most deadly natural disasters in the Iberian Peninsula during the last century. Quite often these floods are associated to intense low pressure systems with an Atlantic origin. In recent years a number of episodes have been evaluated on a case-by-case approach, with a clear focus on extreme events, thus lacking a systematic assessment. In this study we focus on the characteristics of storms for the extended winter season (October to March) that are responsible for the most extreme rainfall events over large areas of the Iberian Peninsula. An objective method for ranking daily precipitation events during the extended winter is used based on the most comprehensive database of high resolution (0.2º latitude by 0.2º longitude) gridded daily precipitation dataset available for the Iberian Peninsula. The magnitude of an event is obtained after considering the total area affected as well as its intensity in every grid point (taking into account the daily normalised departure from climatology). Different precipitation rankings are studied considering the entire Iberian Peninsula, Portugal and also the six largest river basins in the Iberian Peninsula (Duero, Ebro, Tagus, Minho, Guadiana and Guadalquivir). Using an objective cyclone detecting and tracking scheme [Trigo, 2006] the storm track and characteristics of the cyclones were obtained using the ERA-Interim reanalyses for the 1979-2008 period. The spatial distribution of extratropical cyclone positions when the precipitation extremes occur will be analysed over the considered sub-domains (Iberia, Portugal, major river basins). In addition, we distinguish the different cyclone characteristics (lifetime, direction, minimum pressure, position, velocity, vorticity and radius) with significant impacts in precipitation over the different domains in the Iberian Peninsula. This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa

  17. Ecological risk assessments and context-dependence analysis of heavy metal contamination in the sediments of mangrove swamp in Leizhou Peninsula, China.

    PubMed

    Liu, Jing; Ma, Keming; Qu, Laiye

    2015-11-15

    Sediments in eight types of mangroves were sampled in the Leizhou Peninsula. Heavy metals were analyzed to investigate the effects on metal distribution of mangrove communities, to evaluate contamination levels, identify sources and relationships between the two. Results showed that mangrove communities have effects on most heavy metal distributions in sediments, especially in the sediment with shrub communities of Aegiceras corniculatum where the contents of many metals are highest. As, Cr and Ni were identified as metal pollutants of primary concern, while Cd was of no concern. Zn, Pb, As mainly originated from anthropogenic source while the other metals are geogenic. Heavy metal distributions were affected by the independent and joint effects of landscape and sediment context; landscape context explains more variations in heavy metals than does sediment physicochemical variables. Total sulfur, total phosphorus and total potassium in sediment, and the existence of paddy field and forest land within 2000m around the sampling sites are significant variables also.

  18. Ecological risk assessments and context-dependence analysis of heavy metal contamination in the sediments of mangrove swamp in Leizhou Peninsula, China.

    PubMed

    Liu, Jing; Ma, Keming; Qu, Laiye

    2015-11-15

    Sediments in eight types of mangroves were sampled in the Leizhou Peninsula. Heavy metals were analyzed to investigate the effects on metal distribution of mangrove communities, to evaluate contamination levels, identify sources and relationships between the two. Results showed that mangrove communities have effects on most heavy metal distributions in sediments, especially in the sediment with shrub communities of Aegiceras corniculatum where the contents of many metals are highest. As, Cr and Ni were identified as metal pollutants of primary concern, while Cd was of no concern. Zn, Pb, As mainly originated from anthropogenic source while the other metals are geogenic. Heavy metal distributions were affected by the independent and joint effects of landscape and sediment context; landscape context explains more variations in heavy metals than does sediment physicochemical variables. Total sulfur, total phosphorus and total potassium in sediment, and the existence of paddy field and forest land within 2000m around the sampling sites are significant variables also. PMID:26365500

  19. Millennial δ18O oscillations from a replicated Holocene speleothem record from Iberian Peninsula and hemispherical teleconecctions affecting the water cycle

    NASA Astrophysics Data System (ADS)

    Domínguez-Villar, David; Wang, Xianfeng; Krklec, Kristina; Cheng, Hai; Edwards, R. Lawrence

    2016-04-01

    We present a speleothem δ18O record from Kaite Cave in northern Iberian Peninsula covering the last 9.7 ka BP. The record is constructed from four different stalagmites that replicate each other. The age model is based on 63 U-Th dates and over 4500 laminae providing a robust time frame for the record. The δ18O record has characteristic millennial oscillations through the Holocene with periodicity around 2 ka during the Late Holocene and around 1 ka during the Early Holocene. Causes of the millennial δ18O variability are not dominated by the amount of rainfall or atmospheric temperature and other controls of the water cycle are more relevant. The aquifer at this site filters any seasonal bias and speleothems records the inter-annual δ18O variability in precipitation. On the other hand, moisture source analysis at this site shows that significant amount of precipitation is from recycled moisture (continental origin). A variable proportion of this parameter is capable to impact significantly past values of δ18O in precipitation. Thus, we interpret the millennial oscillations of the δ18O record as changes in the hydrological cycle resulting from variable percentages of the recycled precipitation over the Iberian Peninsula. We found that variable amount of recycled precipitation in Iberian Peninsula is related to the location of the Iceland Low pressure cell, although does not correlate with NAO index. Correlation of Kaite δ18O record during the Holocene with other representative records suggests that millennial oscillations are caused by variability of the Gulf Stream/North Atlantic Current that affects atmospheric pressure fields in the North Atlantic. Further correlation of Kaite δ18O record along the world supports that the recorded millennial oscillations of the water cycle are related to persistent variability on the tropical North Atlantic. Only during periods of major sea-ice variability in high-latitudes of the North Atlantic, the later region replaces

  20. Description of three new troglobiontic species of Cybaeodes (Araneae, Liocranidae) endemic to the Iberian Peninsula.

    PubMed

    Ribera, Carles; De Mas, Eva

    2015-01-01

    Three new troglobiontic species of the spider genus Cybaeodes Simon endemic to caves in the southeastern Iberian Peninsula are described and illustrated: Cybaeodes indalo sp. n. from Almería, C. dosaguas sp. n. from València and C. magnus sp. n. from Alacant. The new species confirm the presence of Cybaeodes on the Iberian Peninsula and its wide distribution throughout the Western Mediterranean including Algeria, Tunisia, Italy, France, Spain and the islands of Sardinia, Sicily and Mallorca. A record of C. liocraninus (Simon), from an Iberian cave was probably based on misidentified specimens of C. magnus sp. n. C. liocraninus is known only from Algeria and should be removed from lists of the Iberian fauna. In addition, the three new species are clear candidates for protection: they have highly restricted ranges and show a high degree of adaptation to the subterranean environment. PMID:26249078

  1. Strategy for the meteorological and environmental airborne observations over the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Lee, Chulkyu; Chang, Ki-Ho; Jung, Jae-Won; Cha, Joo-Wan; Choi, Young-Jean; Kim, Kyungsik

    2011-01-01

    Aircraft campaigns for the meteorological and environmental research have been conducted in regional and global scales. The aircraft is increasingly considered as one of the best platforms to get the atmospheric three-dimensional information, especially over sea. We discuss the airborne observation plan and payloads designed for the aircraft campaigns over the Korean Peninsula. The main goals of the campaigns are to (i) conduct precipitation (snow) enhancement experiments with observations of the microphysical properties of clouds, dominantly in winter, (ii) monitor the severe weather generally in summer, (iii) characterize the climate change composition and the outflow of pollution from the Asian continent of the troposphere over the Korean Peninsula generally in spring or fall, and (iv) validate satellite and ground-based remote measurements of tropospheric composition generally in spring or fall.

  2. Electromagnetic sounding of the Kola Peninsula with a powerful extremely low frequency source

    NASA Astrophysics Data System (ADS)

    Velikhov, E. P.; Grigoriev, V. F.; Zhdanov, M. S.; Korotayev, S. M.; Kruglyakov, M. S.; Orekhova, D. A.; Popova, I. V.; Tereschenko, E. D.; Schors, Y. G.

    2011-05-01

    Experiment on electromagnetic sounding of the Kola Peninsula using unique mobile measuring complex of the low-frequency sounding was conducted, allowing to investigate a geoelectric section with a depth of several kilometers on distances up to 100 km from the stationary transmitting aerial. Excess on the order of amplitudes of the vertical component above the horizontal at all frequencies of sounding was registered in a number of points of measurements. This feature managed to be explained quantitatively by circulation of current on regional faults with the closure of current through the sea—before unknown galvanic coastal effect. Interpretation of the results of modeling and neural network solving of inverse problem essentially specifies the fault tectonics of the central part of the Kola Peninsula. Anomaly remote from the observation profile was found out—local pinch of a crustal conductive layer consisting of graphitized rocks and associated with the zone of overthrust.

  3. Description of three new troglobiontic species of Cybaeodes (Araneae, Liocranidae) endemic to the Iberian Peninsula.

    PubMed

    Ribera, Carles; De Mas, Eva

    2015-01-01

    Three new troglobiontic species of the spider genus Cybaeodes Simon endemic to caves in the southeastern Iberian Peninsula are described and illustrated: Cybaeodes indalo sp. n. from Almería, C. dosaguas sp. n. from València and C. magnus sp. n. from Alacant. The new species confirm the presence of Cybaeodes on the Iberian Peninsula and its wide distribution throughout the Western Mediterranean including Algeria, Tunisia, Italy, France, Spain and the islands of Sardinia, Sicily and Mallorca. A record of C. liocraninus (Simon), from an Iberian cave was probably based on misidentified specimens of C. magnus sp. n. C. liocraninus is known only from Algeria and should be removed from lists of the Iberian fauna. In addition, the three new species are clear candidates for protection: they have highly restricted ranges and show a high degree of adaptation to the subterranean environment.

  4. How unique is the tiger beetle fauna (Coleoptera, Cicindelidae) of the Balkan Peninsula?

    PubMed Central

    Jaskuła, Radomir

    2011-01-01

    Abstract The tiger beetle fauna of the Balkan Peninsula is one of the richest in Europe and includes 19 species or 41% of the European tiger beetle fauna. Assembled by their biogeographical origins, the Balkan tiger beetle species fall into 14 different groups that include, Mediterranean, Middle Oriental, Central Asiatic, Euro-Siberian, South and East European, Pannonian-Sarmatian, West Palaearctic, Turano-European and Afrotropico Indo-Mediterranean species. The Mediterranean Sclerophyl and the Pontian Steppe are the Balkan biogeographical provinces with the highest species richness, while the Balkan Highlands has the lowest Cicindelidae diversity. Most species are restricted to single habitat types in lowland areas of the Balkan Peninsula and only Calomera aulica aulica and Calomera littoralis nemoralis occur in respectively 3 and 4 different types of habitat. About 60% of all Balkan Cicindelidae species are found in habitats potentially endangered by human activity. PMID:21738429

  5. Genetic diversity and distinctiveness of the proboscis monkeys (Nasalis larvatus) of the Klias Peninsula, Sabah, Malaysia.

    PubMed

    Munshi-South, Jason; Bernard, Henry

    2011-01-01

    In this study, we sequenced a partial segment of the mitochondrial control region from 21 proboscis monkeys of the Klias peninsula, the last large population remaining on the west coast of Sabah, Malaysia. Our results showed that this population retains substantial genetic variation, and subpopulations from different river systems in the central and southern portions of the Klias share multiple haplotypes. We also compared our data with previously generated sequences from 2 eastern populations of proboscis monkeys in Sabah and found little evidence of regional genetic structure. Based on these results, we argue that conservation efforts should focus on restoring connectivity between central and southern Klias peninsula proboscis monkeys and discuss future analyses needed to better understand the mitochondrial structure of proboscis monkeys in Sabah. PMID:21414965

  6. Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula.

    PubMed

    Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

    2015-02-28

    In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2-7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula.

  7. Geological structures and fault distributions in the Sagami Trough offshore Boso Peninsula

    NASA Astrophysics Data System (ADS)

    Misawa, A.; Ashi, J.; Tokuyama, H.

    2011-12-01

    Around the Boso Peninsula, central Japan, the Philippine Sea Plate (PHS) is subducting beneath the Honshu Island along the Sagami Trough and the Pacific Plate is subducting beneath the PHS plate and the Honshu Island along the Japan Trench. The area offshore Boso Peninsula has very complicated geological histories by the influence of highly oblique convergence of the PHS plate and collision of the Izu-Bonin Arc since 15Ma. The geologic body of this region is composed of the accretionary prism, some part of which is exposed in the Miura and the southern Boso Peninsulas. The geologic body of the offshore Boso Peninsula is also considered as the accretionary prism. Moreover, this area is accompanied with the seismogenic zone in which the large-scale earthquakes such as the 1703 Genroku and 1923 Taisho Kanto earthquakes repeatedly occurred. Additionally, the tsunami and crustal movements also occurred together with earthquakes in this area. Although tsunami generation suggested seafloor crustal movements, the distributions of active faults as well as deep structure near the plate boundary have not been yet well understood by previous studies (ex. Nakamura et al., 1987, EPSL; Kimura et al., 2009, Tectonophysics). The objective of this study is to elucidate the submarine structure and distribution of active faults offshore Boso Peninsula in the Sagami Trough using various kinds of data sets as the bathymetric map, IZANAGI side-scan imagery, and Multi-channel seismic (MCS) reflection profiles. These data sets were acquired by JAMSTEC, Japan Coast Guard and Ocean Research Institute (now Atmosphere and Ocean Research Institute), Univ. Tokyo, respectively. In the area offshore Boso Peninsula, geomorhological lineaments were recognized in high accuracy bathymetric map and side-scan sonar imagery. These lineaments are interpreted to be continuous fault scarp morphologies. Along the Katsuura canyon, an approximately 125 km-length lineament was identified. This lineament is

  8. Monterey peninsula water supply project supplemental draft environmental impact report/statement II. Volume 1

    SciTech Connect

    Not Available

    1993-03-12

    The Monterey Peninsula Water Management District (MPWMD) has examined 5 alternatives with the basic project purpose of providing a municipal water supply to the Monterey Peninsula that would provide adequate drought protection for existing residents and meet the long term water supply needs of planned growth. The overall project purpose is to provide adequate instream flow to protect the public trust resources of the Carmel River. The 5 alternatives studied are; a 24,000 AF New Los Padres Reservoir, either alone or combined with a 3 MGD desalination plant; a 15,000 AF Canada Reservoir and 3 MGD Desalination Plant; a 7 MGD desalination Plant; and No project.... Water supply, Dams, Section 404 permits.

  9. Monterey peninsula water supply project supplemental draft environment impact report/statement II. Volume 2

    SciTech Connect

    Not Available

    1993-03-12

    The Monterey Peninsula Water Management District (MPWMD) has examined 5 alternatives with the basic project purpose of providing a municipal water supply to the Monterey Peninsula that would provide adequate drought protection for existing residents and meet the long term water supply needs of planned growth. The overall project purpose is to provide adequate instream flow to protect the public trust resources of the Carmel River. The 5 alternatives studied are; a 24,000 AF New Los Padres Reservoir, either alone or combined with a 3 MGD desalination plant; a 15,000 AF Canada Reservoir and 3 MGD Desalination Plant; a 7 MGD desalination Plant; and No project.... Water supply, Dams, Section 404 permits.

  10. Monterey peninsula water supply project supplemental draft environment impact report/statement II. Appendices

    SciTech Connect

    Not Available

    1993-03-12

    The Monterey Peninsula Water Management District (MPWMD) has examined 5 alternatives with the basic project purpose of providing a municipal water supply to the Monterey Peninsula that would provide adequate drought protection for existing residents and meet the long term water supply needs of planned growth. The overall project purpose is to provide adequate instream flow to protect the public trust resources of the Carmel River. The 5 alternatives studied are: a 24,000 AF New Los Padres Reservoir, either alone or combined with a 3 MGD desalination plant; a 15,000 AF Canada Reservoir and 3 MGD Desalination Plant; a 7 MGD desalination Plant; and No project.... Water supply, Dams, Section 404 permits.

  11. Acceleration and spatial rheology of Larsen C Ice Shelf, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Khazendar, A.; Rignot, E.; Larour, E.

    2011-05-01

    The disintegration of several Antarctic Peninsula ice shelves has focused attention on the state of the Larsen C Ice Shelf. Here, we use satellite observations to map ice shelf speed from the years 2000, 2006 and 2008 and apply inverse modeling to examine the spatial pattern of ice-shelf stiffness. Results show that the northern half of the ice shelf has been accelerating since 2000, speeding up by 15% between 2000 and 2006 alone. The distribution of ice stiffness exhibits large spatial variations that we link to tributary glacier flow and fractures. Our results reveal that ice down-flow from promontories is consistently softer, with the exception of Churchill Peninsula where we infer a stabilizing role for marine ice. We conclude that although Larsen C is not facing imminent collapse, it is undergoing significant change in the form of flow acceleration that is spatially related to thinning and fracture.

  12. A diverse assemblage of fossil hardwood from the Upper Tertiary (Miocene?) of the Arauco Peninsula, Chile

    NASA Astrophysics Data System (ADS)

    Schöning, Meike; Bandel, Klaus

    2004-09-01

    Silicified woods of 10 dicotyledonous tree families of probably Miocene age from the Arauco Peninsula, central Chile are described and classified according to their anatomy. The diversity is surprisingly high, in that of the 19 samples analyzed, virtually every one could belong to a different species of tree or shrub. Almost all species document a damp climate, and most have related species living in the central zone of modern Chile. The samples were collected in a narrow zone on Punta El Fraile, west of the town of Arauco. The following families are based on woods from the Arauco Peninsula: Anacardiaceae, Boraginaceae, Euphorbiaceae, Fagaceae, Lauraceae, Leguminosae, Monimiaceae, the first report of fossil Myristicaceae, Myrtaceae, and Proteaceae. Their diagenetic history is connected to tuffaceous material and calcareous concretions.

  13. [Diagnostic Criteria for Amyotrophic Lateral Sclerosis/Parkinsonism-Dementia Complex in the Kii Peninsula, Japan].

    PubMed

    Kokubo, Yasumasa

    2015-07-01

    The diagnostic criteria for amyotrophic lateral sclerosis/parkinsonism-dementia complex in the Kii peninsula of Japan (Kii ALS/PDC) have been proposed. Muro disease has been considered an endemic neurodegenerative disease in the southern part of the Kii peninsula. Recent intensive and comprehensive research has revealed it to be a complex and genetically heterogeneous disease. At present, there are four subtypes of Muro disease: sporadic amyotrophic lateral sclerosis (ALS), Kii ALS/PDC with tauopathy, ALS with C9orf72 gene mutation, and ALS with optineurin gene mutation. The present criteria are applicable to only one of these subtypes, Kii ALS/PDC with tauopathy, which is quite similar to ALS/PDC in Guam.

  14. [Distribution of Ecteinascidia turbinata (Ascidiacea: Perophoridae) in mangroves of the Yucatán Peninsula, Mexico].

    PubMed

    Carballo, J L

    2000-01-01

    The ascidian Ecteinascidia turbinata synthesizes some of the most promising substances against solid-type tumors, but the only available source are the natural populations of this tunicate, which is reared or collected in different parts of the world. A total of 33 locations were sampled in the Gulf of Mexico and the Yucatan Peninsula. The tunicate was not found in Veracruz, Tabasco and Campeche, but it was well established on mangrove roots in the Yucatan Peninsula where we estimated densities more or less equal to one colony and an average production of 115 g of biomass per lineal meter of mangrove coastline in one location (Río Lagartos). Sustainable management appears to be possible.

  15. Climatological classification of five sectors in the Iberian Peninsula using columnar (AOD, α) and surface (PM10, PM2.5) aerosol data supported by air mass apportioning

    NASA Astrophysics Data System (ADS)

    Cachorro, Victoria; Mateos, David; Toledano, Carlos; Burgos, Maria A.; Bennouna, Yasmine; Torres, Benjamín; Fuertes, David; González, Ramiro; Guirado, Carmen; Román, Roberto; Velasco-Merino, Cristian; Marcos, Alberto; Calle, Abel; de Frutos, Angel M.

    2015-04-01

    The study of atmospheric aerosol over the Iberian Peninsula (IP) under a climatologic perspective is an interesting and meaningful aim due to the wide variety of conditions (geographical position, air masses, topography, among others) which cause a complex role of the distribution of aerosol properties. In the deeply investigation on the annual cycle and time evolution of the particulate matter lower than 10 µm (PM10, surface) and aerosol optical depth (AOD, columnar) in a large number of sites covering the period 2000-2013, five sectors can be distinguished in the IP. Both set of data belong to EMEP and AERONET networks respectively, as representative of aerosol air quality and climate studies, are complementary elements for a global aerosol research. The prevalence of fine-coarse particles is also analyzed over each sector. Seasonal bimodality of the PM10 annual cycle with a strong North-South gradient is observed in most sites, but this is only reported in the AOD climatology for the southern IP. The northern coast is clearly governed by the Atlantic Ocean influence, while the northeastern area is modulated by the Mediterranean Sea. The southern area, very close to the African continent, presents a large influence of desert dust intrusions. However, the southern Atlantic and Mediterranean coast present discrepancies and two sectors have been defined in this area. Finally, the center of the Peninsula is a mix of conditions, with north-south and east-west gradients of different magnitude. Overall, there is a relationship between PM10 and AOD with a proportional factor varying from 20 to 90, depending on the sector. The particular characteristic of PM10-AOD annual cycle of each geographical sector can be understood by the different climatology of the air mass origins observed at 500 and 1500 m (a.s.l.) and its apportioning to PM10 and AOD, respectively.

  16. Hosts of the exotic ornate kangaroo tick, Amblyomma triguttatum triguttatum Koch, on southern Yorke Peninsula, South Australia.

    PubMed

    Waudby, Helen P; Petit, Sophie; Dixon, Bruce; Andrews, Ross H

    2007-10-01

    Amblyomma triguttatum triguttatum is assumed to be endemic to south-western Western Australia (including Barrow Island), Queensland (excluding Cape York Peninsula), and New South Wales, south to Dubbo and Barham. The species has been recorded on a range of mammalian hosts including macropods and domestic animals. In Queensland, A. triguttatum triguttatum is implicated in the epidemiology of Q fever. In 2000, the species was detected on southern Yorke Peninsula in South Australia. We aimed to identify A. triguttatum triguttatum's hosts through trapping, sampling of carcasses, and opportunistic capture of vertebrates on Yorke Peninsula. A. triguttatum triguttatum was removed from black rats (Rattus rattus), wild rabbits (Oryctolagus cuniculus), western grey kangaroos (Macropus fuliginosus), Tammar wallabies (M. eugenii eugenii), domesticated cats and dogs, and humans. Before this study, A. triguttatum triguttatum had not been found on black rats or rabbits in the wild. This research has implications for the management of wildlife, livestock, and visitors on Yorke Peninsula. The potential for A. triguttatum triguttatum to spread to other areas of Yorke Peninsula and South Australia is considerable, as visitors (tourists) to southern Yorke Peninsula report the presence of ticks both on themselves and among camping equipment on arriving home.

  17. Ground-water-quality assessment of the Delmarva Peninsula, Delaware, Maryland, and Virginia; project description

    USGS Publications Warehouse

    Bachman, L.J.; Shedlock, R.J.; Phillips, P.J.

    1987-01-01

    In April 1986, the U.S. Geological Survey began a pilot program to assess the quality of the Nation 's surface water and groundwater resources. This National Water-Quality Assessment (NAWQA) program is designed to acquire and interpret information about a wide range of water quality issues. Three groundwater pilot projects have been started, including the project on the Delmarva Peninsula, which covers eastern Maryland and Virginia and most of Delaware. The objectives of the Delmarva project are to: (1) investigate regional groundwater quality on the Delmarva Peninsula, emphasizing a description of the occurrence of trace elements and manmade organic compounds; (2) relate groundwater quality to land use and geohydrologic conditions; and (3) provide a general description of the location, nature, and possible causes of selected water quality problems prevalent in the study area. The shallow aquifer system and the deeper aquifers used for public water supply will be addressed. The shallow aquifer system in the Delmarva Peninsula consists of permeable unconsolidated sand and gravel. Flow systems are localized and small-scale. Farming is common on the peninsula, and the migration of agricultural chemicals to the groundwater system is a local water quality concern. To assess the water quality of the groundwater resources, a regional survey for a wide range of constituents will be conducted in all of the pilot projects to provide a representative sample of groundwater analyses for a national assessment of groundwater quality. Results of this survey may be used as a baseline to monitor future water quality trends. (Lantz-PTT)

  18. Upper-crust Tomographic Structure of the Southern Korea Peninsula from Local Earthquakes

    NASA Astrophysics Data System (ADS)

    Kim, K. H.; Park, J. H.; Kang, S. Y.

    2015-12-01

    We derived the three dimensional P wave velocity model for the uppermost 14 km of crust in the southern Korea peninsula using travel-time data from local earthquakes which are recorded by two nation-wide seismic networks operated by Korea Meteorological Administration and Korea Institute of Geoscience and Mineral Resources. Earthquakes in the study occurred between 2001 and 2014. 19,935 P wave arrivals from 747 earthquakes observed by 184 seismic stations are selected for the 3-D tomographic inversion. In order to secure best possible data for tomography inversion, we applied a strict criteria during the selection of earthquakes and travel-times. The study area is parameterized by 10km×10km×4km grid for velocity inversion and 1km×1km×1km grid for travel time calculations. Checkerboard resolution test are used to demonstrate the ray coverage and the resolution for the given station-event configurations. The results indicate P-wave velocity model at shallow depths less than 2 km are not properly resolved mainly due to the insufficient ray coverage. The model at deeper depths greater than 14 km also suffered by lack of ray coverage. Thus, we limit our interpretations of the preliminary P wave velocity model to areas that are illuminated by enough rays. P wave velocity model indicates there are significant lateral velocity variations across the southern Korea peninsula. Most distinguished feature in the velocity model is the higher velocity anomaly beneath the southeastern Korea peninsula. The anomaly regions is distinguished by well-defined tectonic boundary. At 8 km depth, lower velocity anomaly is observed in Gyeonggi massif and high-mountain regions in the southern Korea peninsula. The 3-D velocity model is compared with geophysical and geological observations.

  19. An Anvilian (early pleistocene) marine fauna from western Seward Peninsula, Alaska

    USGS Publications Warehouse

    Hopkins, D.M.; Rowland, R.W.; Echols, R.E.; Valentine, P.C.

    1974-01-01

    Cover sediments of the York Terrace exposed near the California River, western Seward Peninsula, Alaska, yield mollusks, ostracodes, and foraminifera that lived during the Anvilian transgression of early Pleistocene age. The fossiliferous sediments lie at the inner edge of the York Terrace, a deformed wave-cut platform that extends eastward from Bering Strait along much of the southern coast of Seward Peninsula. The seaward margin is truncated by the little-deformed Lost River Terrace, carved during the Pelukian (Sangamonian) transgression. The early Pleistocene sediments seem to have been deposited between the first and second of four glaciations for which evidence can be found in the California River area. The California River fauna includes several extinct species and several species now confined to areas as remote as the northwestern Pacific and north Atlantic. The fauna probably lived in water temperatures much like those of the present time but deeper water on the Bering Shelf is suggested. The presence of an early Pleistocene fauna at the inner edge of the York Terrace at California River shows that the terrace was largely carved before and during early Pleistocene time. However, a marine fauna apparently of middle Pleistocene age is found on the York Terrace near Cassiterite Peak, and this seems to indicate that the terrace remained low until middle Pleistocene time. Uplift of the York Terrace probably was accompanied by uplift of Bering Strait. The strait may have been deeper, and there may have been no land bridge between the Seward Peninsula of Alaksa and the Chukotka Peninsula of Siberia during most of early and middle Pleistocene time. ?? 1974.

  20. Geological and Petrological Characteristics of Oligocene Magmatic Rocks in The Biga Peninsula, NW Turkey

    NASA Astrophysics Data System (ADS)

    Erenoglu, Oya

    2016-04-01

    Oligocene magmatic activity in the Biga Peninsula (NW-Anatolia) produced widespread volcano-plutonic complexes. The study region, where in north of the Evciler village in the middle of Biga Peninsula includes these igneous assemblages. In this study, the petrographic and geochemical characteristics of igneous rocks in the region were investigated as well as the geological locations. The magmatic rocks are classified as 6 different units using their lithostratigraphical properties. The volcanism in the region starts with basaltic andesite lava including basalt dykes in the Lower Oligocene. In the Upper Oligocene, the evolved magma by crustal contamination produced commonly dacitic and andesitic lavas. The volcanism continued with andesitic lavas which had significant alterations in the region during this period. Evciler pluton including granite and granodiorite composition with shallow intrusive, was located with the related volcanism at the same time. The volcanic products, i.e. andesitic and trachydacitic lavas, was completed in the interval between Upper Oligocene and Lower Miocene. The post-collisional Oligocene sequence is associated with calc-alkaline composition and it has middle, high-K. Trace and rare earth elements (REE) diagrams show the enrichment in both large-ion lithophile elements (LILE) and light rare earth elements (LREE) with respect to the high field strength elements (HFSE), and a significant increment in heavy rare earth element consumption (HREE). The features of major, trace and rare earth elements of plutonic and volcanic rocks and the compositional variations of Oligocene volcanic group indicate increasing amounts of partial melting, crustal contamination and/or assimilation. The Oligocene post-collisional volcanism in Biga Peninsula points out the lithospheric mantle source enriched by subduction which controlled by slab break-off and lithospheric delamination. Acknowledgement. This study was supported by Canakkale Onsekiz Mart University

  1. Penguin eggshell membranes reflect homogeneity of mercury in the marine food web surrounding the Antarctic Peninsula.

    PubMed

    Brasso, Rebecka L; Polito, Michael J; Lynch, Heather J; Naveen, R; Emslie, Steven D

    2012-11-15

    Remote regions such as the Antarctic have become increasingly important for investigations into far-reaching anthropogenic impacts on the environment, most recently in regard to the global mercury cycle. Spatial patterns of mercury availability in four regions of the Antarctic Peninsula were investigated using three species of sympatrically breeding Pygoscelis penguins as biomonitors. Eggshells with intact membranes from Adélie, Gentoo, and Chinstrap penguins were collected at 24 breeding colonies in the South Orkney Islands, South Shetland Islands, eastern Antarctic Peninsula, and western Antarctic Peninsula during the 2006/2007 austral summer. In addition, we compared eggshell membrane mercury concentrations with eggshell stable isotope values (δ(15)N and δ(13)C) to determine if species-specific trophic or foraging habitat preferences influenced female mercury exposure prior to breeding. With few exceptions, mercury concentrations were found to be fairly homogeneous throughout the Antarctic Peninsula suggesting little spatial variation in the risk of exposure to dietary mercury in this food web. Mercury concentrations in Gentoo and Adélie penguins were similar while Chinstrap penguins tended to have higher eggshell membrane mercury concentrations than their congeners. However, inter and intra-specific differences in eggshell membrane mercury concentration were not related to eggshell δ(15)N or δ(13)C values, a likely result of all three species foraging at similar trophic positions. The lack of regional-scale differences in mercury availability in this marine ecosystem may be a reflection of generally uniform atmospheric deposition and upwelling of regionally homogeneous deep water rather than from geographically distinct point sources.

  2. Three-dimensional upper crustal velocity structure beneath San Francisco Peninsula, California

    USGS Publications Warehouse

    Parsons, T.; Zoback, M.L.

    1997-01-01

    This paper presents new seismic data from, and crustal models of the San Francisco Peninsula. In much of central California the San Andreas fault juxtaposes the Cretaceous granitic Salinian terrane on its west and the Late Mesozoic/Early Tertiary Franciscan Complex on its east. On San Francisco Peninsula, however, the present-day San Andreas fault is completely within a Franciscan terrane, and the Pilarcitos fault, located southwest of the San Andreas, marks the Salinian-Franciscan boundary. This circumstance has evoked two different explanations: either the Pilarcitos is a thrust fault that has pushed Franciscan rocks over Salinian rocks or the Pilarcitos is a transform fault that has accommodated significant right-lateral slip. In an effort to better resolve the subsurface structure of the peninsula faults, we established a temporary network of 31 seismographs arrayed across the San Andreas fault and the subparallel Pilarcitos fault at ???1-2 km spacings. These instruments were deployed during the first 6 months of 1995 and recorded local earthquakes, air gun sources set off in San Francisco Bay, and explosive sources. Travel times from these sources were used to augment earthquake arrival times recorded by the Northern California Seismic Network and were inverted for three-dimensional velocity structure. Results show lateral velocity changes at depth (???0.5-7 km) that correlate with downward vertical projections of the surface traces of the San Andreas and Pilarcitos faults. We thus interpret the faults as high-angle to vertical features (constrained to a 70??-110?? dip range). From this we conclude that the Pilarcitos fault is probably an important strike-slip fault that accommodated much of the right-lateral plate boundary strain on the peninsula prior to the initiation of the modern-day San Andreas fault in this region sometime after about 3.0 m.y. ago.

  3. First record of Hermetia illucens (Diptera: Stratiomyidae) on human corpses in Iberian Peninsula.

    PubMed

    Martínez-Sánchez, Anabel; Magaña, Concepción; Saloña, Marta; Rojo, Santos

    2011-03-20

    This article presents the first record of Hermetia illucens larvae on a human corpse in Spain (the second case report in Europe). Prepupae of H. illucens, and other insects, were recovered from the dead body of a 72-year-old man in an advanced stage of decomposition. The body was located in Reus (NE Spain), in October 1998. This article provides additional biological data on experimental studies and an update on the geographic distribution of this species in the Iberian Peninsula.

  4. Holocene Southern Ocean surface temperature variability west of the Antarctic Peninsula.

    PubMed

    Shevenell, A E; Ingalls, A E; Domack, E W; Kelly, C

    2011-02-10

    The disintegration of ice shelves, reduced sea-ice and glacier extent, and shifting ecological zones observed around Antarctica highlight the impact of recent atmospheric and oceanic warming on the cryosphere. Observations and models suggest that oceanic and atmospheric temperature variations at Antarctica's margins affect global cryosphere stability, ocean circulation, sea levels and carbon cycling. In particular, recent climate changes on the Antarctic Peninsula have been dramatic, yet the Holocene climate variability of this region is largely unknown, limiting our ability to evaluate ongoing changes within the context of historical variability and underlying forcing mechanisms. Here we show that surface ocean temperatures at the continental margin of the western Antarctic Peninsula cooled by 3-4 °C over the past 12,000 years, tracking the Holocene decline of local (65° S) spring insolation. Our results, based on TEX(86) sea surface temperature (SST) proxy evidence from a marine sediment core, indicate the importance of regional summer duration as a driver of Antarctic seasonal sea-ice fluctuations. On millennial timescales, abrupt SST fluctuations of 2-4 °C coincide with globally recognized climate variability. Similarities between our SSTs, Southern Hemisphere westerly wind reconstructions and El Niño/Southern Oscillation variability indicate that present climate teleconnections between the tropical Pacific Ocean and the western Antarctic Peninsula strengthened late in the Holocene epoch. We conclude that during the Holocene, Southern Ocean temperatures at the western Antarctic Peninsula margin were tied to changes in the position of the westerlies, which have a critical role in global carbon cycling.

  5. The ant genus Carebara Westwood in the Arabian Peninsula (Hymenoptera, Formicidae)

    PubMed Central

    Sharaf, Mostafa R.; Aldawood, Abdulrahman S.

    2013-01-01

    Abstract The ant genus Carebara of the Arabian Peninsula is revised. Carebara abuhurayri Sharaf & Aldawood, 2011 is synonymized under Carebara arabica Collingwood & van Harten, 2001. Carebara arabica is redescribed and a Neotype is fixed based on a specimen collected from southwestern Kingdom of Saudi Arabia. A new species, C. fayrouzae sp. n. is described from Saudi Arabia based on queens, major and minor workers. Keys to major and minor workers of the two Arabian Carebara species are given. PMID:24363580

  6. Spatial Distribution of Dorylaimid and Mononchid Nematodes from Southeast Iberian Peninsula: Chorological Relationships among Species

    PubMed Central

    Liébanas, G.; Peña-Santiago, R.; Real, R.; Márquez, A. L.

    2002-01-01

    The spatial distribution of 138 Dorylaimid and Mononchid species collected in a natural area from the Southeast Iberian Peninsula was studied. A chorological classification was used to examine distribution patterns shared by groups of species. Eighty species were classified into 14 collective and 16 individual chorotypes. The geographical projections of several collective chorotypes are illustrated along with their corresponding distribution maps. The importance of this analysis to nematological study is briefly discussed. PMID:19265962

  7. The Polyploid Series of the Achillea millefolium Aggregate in the Iberian Peninsula Investigated Using Microsatellites

    PubMed Central

    López-Vinyallonga, Sara; Soriano, Ignasi; Susanna, Alfonso; Montserra, Josep Maria; Roquet, Cristina; Garcia-Jacas, Núria

    2015-01-01

    The Achillea millefolium aggregate is one of the most diverse polyploid complexes of the Northern hemisphere and has its western Eurasian boundary in the Iberian Peninsula. Four ploidy levels have been detected in A. millefolium, three of which have already been found in Iberia (diploid, hexaploid and octoploid), and a fourth (tetraploid) reported during the preparation of this paper. We collected a sample from 26 Iberian populations comprising all ploidy levels, and we used microsatellite markers analyzed as dominant in view of the high ploidy levels. Our goals were to quantify the genetic diversity of A. millefolium in the Iberian Peninsula, to elucidate its genetic structure, to investigate the differences in ploidy levels, and to analyse the dispersal of the species. The lack of spatial genetic structure recovered is linked to both high levels of gene flow between populations and to the fact that most genetic variability occurs within populations. This in turn suggests the existence of a huge panmictic yarrow population in the Iberian Peninsula. This is consistent with the assumption that recent colonization and rapid expansion occurred throughout this area. Likewise, the low levels of genetic variability recovered suggest that bottlenecks and/or founder events may have been involved in this process, and clonal reproduction may have played an important role in maintaining this genetic impoverishment. Indeed, the ecological and phenologic uniformity present in the A. millefolium agg. in Iberia compared to Eurasia and North America may be responsible for the low number of representatives of this complex of species present in the Iberian Peninsula. The low levels of genetic differentiation between ploidy levels recovered in our work suggest the absence of barriers between them. PMID:26091537

  8. Arabian Peninsula and northeast Africa as seen from Gemini 11 spacecraft

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Arabian Peninsula (on left) and northeast Africa (on right) as seen from the Gemini 11 spacecraft at an altitude of 340 nautical miles during its 27th revolution of the earth, looking southeast. Saudia Arabia, South Arabia, Yemen and Aden Protectorate are at left. At bottom right is Ethiopia. French Somaliland is in center on right shore. Somali is at upper right. Body of water at bottom is Red Sea. Gulf of Aden is in center; and at top left is Indian Ocean.

  9. A Radial Pattern of Six Paleo Ice Streams Emanating from the Bruce Plateau Ice Dome, Antarctic Peninsula Ice Sheet: Constraints from Multibeam Bathymetry and GPS Rebound

    NASA Astrophysics Data System (ADS)

    Fried, M.; Domack, E.; Canals, M.; Casamor, J.; King, M.

    2008-12-01

    We reconstructed ice thicknesses along six paleo ice streams emanating out of the Bruce Plateau in the Northern Antarctic Peninsula. This was done in order to generate models of potential isostatic rebound along the flow paths since the LGM and thereby provide a theoretical test for empirical observations of vertical displacement (rebound) as measured by seven coastal GPS stations (to be deployed during the current IPY- LARISSA project). This study is pertinent to realizing the effect of moderate ice sheet size during collapse and resulting sea level rise. The Palmer, Vernadsky, Hugo Island and Gerlache and Boyd Strait ice stream paths (flow lines) were highlighted on the Western side of the Peninsula. The Drygalski, Crane and Hektoria ice streams were studied on the Eastern side. Using detailed and near complete swath bathymetry data available for the Western Peninsula coastal region and partial swath mapping data generated at the site of the former Larsen B ice shelf (and Roberston Trough), we constructed hypothetical longitudinal profiles of all six ice streams along precisely located flow paths. These profiles extended from the accumulation zones in the upper elevations of the Bruce Plateau to the terminus along the continental shelf edge. The profiles included detailed elevations of the bedrock and hypothetical ice thickness values along the ice streams as they would have been during the Last Glacial Maximum (~ 16 ka). Ice thickness values were based on the elevations of bedrock, trim lines, surrounding topography, influence of surrounding glaciers and previous estimates of LGM ice thickness values around the Antarctic Peninsula. Using the components of the hypothetical longitudinal profiles, total isostatic rebound since the LGM can be calculated for the region (assuming reasonable mantle viscosities). In all the profiles reconstructed ice thicknesses are characterized by an order of magnitude increase across inner shelf troughs (such as the Palmer Deep and

  10. Response of Peatland Carbon Accumulation to Postglacial Climate Changes on the Seward Peninsula, Western Alaska

    NASA Astrophysics Data System (ADS)

    Hunt, S. J.; Yu, Z.

    2011-12-01

    Understanding how carbon-rich peatland ecosystems have responded to past warm climates in terms of carbon (C) dynamics and community composition is crucial for projecting possible future changes. Warm climates in the recent past, such as the Bølling-Allerød interstadial (14.7-12.7 cal ka) and Holocene Thermal Maximum (HTM; 11-9 ka), provide unique opportunities to study peatland C dynamics and ecosystem change. Here we present preliminary data from a 272-cm peat core (core NL10-2) collected from the edge of Niukluk Lake on Seward Peninsula, Alaska (64° 49.645' N, 163° 27.235' W; elevation = 16 m asl). Niukluk Lake is a thermokarst lake located in the discontinuous permafrost zone near the forest-tundra ecotone and experiences a maritime climate, which is controlled by the Bering Sea and sea surface conditions (especially sea-ice extent). The chronology is based on 12 AMS dates from Sphagnum and other terrestrial plant macrofossils over the last 13.5 ka. Organic matter content (OM) shows a long-term increasing trend throughout the core since 13.5 ka, ranging from <20% at the bottom to >90% at the top of the core. Peat began accumulating at this site by 13.5 ka and was initially characterized by a very high carbon accumulation rate (67 g C m-2 yr-1 from 13.5 to 12.8 ka), potentially due to early deglacial warming during the Bølling-Allerød period. Dominance of well-preserved brown moss, aquatic species and high C accumulation rates during the majority of the Bølling-Allerød indicate a wet peatland surface and possibly a wet and warm climate. Preliminary pollen analysis during the Bølling-Allerød indicates a Betula and Salix dominated upland with a regional presence of Picea and Larix, along with the presence of aquatic species. Also, abundant charcoals are present at this interval, suggesting that wildfires might play a major role in modulating regional flora and permafrost dynamics. This highly productive period was followed by a hiatus from 12.8 ka to 9

  11. Fishery biology and management of Protonibea diacanthus (Sciaenidae) aggregations in far Northern Cape York Peninsula waters

    NASA Astrophysics Data System (ADS)

    Phelan, M. J.; Gribble, N. A.; Garrett, R. N.

    2008-09-01

    The sciaenid Protonibea diacanthus is a large, long-lived predatory fish of inshore northern Australian waters, which forms annual aggregations that are fished extensively by traditional (subsistence) and recreational fishers. There are now widespread concerns that the resource is being overexploited. Indigenous fishers of the Cape York Northern Peninsula Area (NPA) relate that large adult fish (up to 1500 mm total length (TL)) made up the bulk of the catch from the sciaenid aggregations until about 1994. In contrast, sexually mature P. diacanthus comprised only a small component (12 fish out of 270=4.4%) examined in a 1999-2000 sampling programme that was biased towards the largest individuals available. At 790 mm TL, the minimum size at first maturity for female P. diacanthus in this study is much smaller than the 920 mm TL reported previously in Queensland waters. Developing ovaries were observed in specimens sampled from sciaenid aggregations which formed in NPA waters between May and September 2000. However, no fish with ripe or spent gonads were found in the study, so the current timing and location of the spawning season for P. diacanthus in the region remain unknown. Food items observed in the analysis of the diet of P. diacanthus from the NPA included a variety of teleosts and invertebrates. The range of animal taxa represented in the prey items support the description of an 'opportunistic predator' attributed to the species. In our sampling, the stomach contents of fish caught during the time of the aggregation events did not differ from those observed at other times of the year. A total of 114 P. diacanthus were tagged and released at aggregation sites during the study period, and 3 fish (2.6%) were subsequently recaptured. The low rate of tag returns from the wild stock tagging programme, both in this study (2.6%) and from recreational fisher tag/release programmes for the sciaenid elsewhere in Queensland (6.5%), were not explained by tag loss nor

  12. Structural characterization and composition of Y-rich hainite from Sakharjok nepheline syenite pegmatite (Kola Peninsula, Russia)

    NASA Astrophysics Data System (ADS)

    Lyalina, L.; Zolotarev, A.; Selivanova, E.; Savchenko, Ye.; Zozulya, D.; Krivovichev, S.; Mikhailova, Yu.

    2015-08-01

    Y-rich hainite occurs in nepheline syenite pegmatite of the Sakharjok massif (Kola Peninsula, Russia). It forms euhedral prismatic crystals up to 2 mm in length as well as rims around an unidentified mineral phase (silicate of Ca, Y, Zr and Ti). The mineral is triclinic, space group P-1, a 9.6054(10), b 5.6928(6), c 7.3344(7) Å, α 89.903(2), β 101.082(2), γ 100.830(2)°, V 386.32(7) Å3, Z = 1. The calculated density is 3.39 g/cm3. Chemical composition of Sakharjok hainite is different from the previously published data by much higher Y and Nb contents up to 0.72 and 0.20 atoms per formula unit, respectively, by the two- to five-fold depletion in the LREEs and by the strong enrichment of the HREEs. From the single-crystal X-ray diffraction data, there is a significant amount of Y in the M1 site associated with the absence of Zr in it. Nb and Zr are concentrated in the M5 site substituting Ti. Combination of single-crystal X-ray diffraction data and electron microprobe data give the empirical formula (Ca1.04Y0.63REE0.24Mn0.02)∑1.93(Na0.92Ca0.77)∑1.69Ca2.00(Na0.65Ca0.10)∑0.75(Ti0.60Zr0.21Nb0.15Fe0.03)∑0.99((Si4.00Al0.02)∑4.02O14) (F2.61O1.39)∑4.00.

  13. Surveillance of Viruses in Wild Fish Populations in Areas around the Gulf of Cadiz (South Atlantic Iberian Peninsula)

    PubMed Central

    Moreno, Patricia; Olveira, José G.; Labella, Alejandro; Cutrín, Juan Manuel; Baro, Jorge C.; Borrego, Juan Jose

    2014-01-01

    This report describes a viral epidemiological study of wild fish around the Gulf of Cadiz (southwestern Iberian Peninsula) and is focused on infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), and viral nervous necrosis virus (VNNV). One fish species (Chelon labrosus) was sampled inside the gulf, at the mouth of the San Pedro River. Another 29 were sampled, in three oceanographic campaigns, at sites around the Bay of Cadiz. The fish were processed individually and subjected to isolation in cell culture and molecular diagnosis. VHSV was not isolated from any species. Thirteen IPNV-type isolates were obtained from barracuda (Sphyraena sphyraena), axillary seabream (Pagellus acarne), common two-banded seabream (Diplodus vulgaris), common pandora (P. erythrinus), Senegal seabream (D. bellottii), and surmullet (Mullus surmuletus). Six VNNV isolates were obtained from axillary seabream, common pandora, black seabream (Spondyliosoma cantharus), red mullet (Mullet barbatus), Lusitanian toadfish (Halobatrachus didactylus), and tub gurnard (Chelidonichtys lucerna). In the river mouth, viruses were detected only after reamplification, obtaining prevalence percentages of IPNV and VNNV (44.4 and 63.0%, respectively) much higher than those observed in the oceanographic campaigns (25.7 and 19.6%, respectively). The opposite results were obtained in the case of VHSV after reamplification: 11.1% in the river mouth and 43.6% in the oceanic locations. Analyzing the results with respect to the proximity of the sampling sites to the coast, an anthropogenic influence on wild fish is suggested and discussed. The type of viruses and the presence of natural reassortants are also discussed. PMID:25128341

  14. Late Cretaceous-early Eocene counterclockwise rotation of the Fueguian Andes and evolution of the Patagonia-Antarctic Peninsula system

    NASA Astrophysics Data System (ADS)

    Poblete, F.; Roperch, P.; Arriagada, C.; Ruffet, G.; Ramírez de Arellano, C.; Hervé, F.; Poujol, M.

    2016-02-01

    The southernmost Andes of Patagonia and Tierra del Fuego present a prominent arc-shaped structure: the Patagonian Bend. Whether the bending is a primary curvature or an orocline is still matter of controversy. New paleomagnetic data have been obtained south of the Beagle Channel in 39 out of 61 sites. They have been drilled in Late Jurassic and Early Cretaceous sediments and interbedded volcanics and in mid-Cretaceous to Eocene intrusives of the Fuegian Batholith. The anisotropy of magnetic susceptibility was measured at each site and the influence of magnetic fabric on the characteristic remanent magnetizations (ChRM) in plutonic rocks was corrected using inverse tensors of anisotropy of remanent magnetizations. Normal polarity secondary magnetizations with west-directed declination were obtained in the sediments and they did not pass the fold test. These characteristic directions are similar to those recorded by mid Cretaceous intrusives suggesting a remagnetization event during the normal Cretaceous superchron and describe a large (> 90°) counterclockwise rotation. Late Cretaceous to Eocene rocks of the Fueguian Batholith, record decreasing counterclockwise rotations of 45° to 30°. These paleomagnetic results are interpreted as evidence of a large counterclockwise rotation of the Fueguian Andes related to the closure of the Rocas Verdes Basin and the formation of the Darwin Cordillera during the Late Cretaceous and Paleocene. The tectonic evolution of the Patagonian Bend can thus be described as the formation of a progressive arc from an oroclinal stage during the closure of the Rocas Verdes basin to a mainly primary arc during the final stages of deformation of the Magallanes fold and thrust belt. Plate reconstructions show that the Antarctic Peninsula would have formed a continuous margin with Patagonia between the Early Cretaceous and the Eocene, and acted as a non-rotational rigid block facilitating the development of the Patagonian Bend.

  15. Local population structure in Arabian Peninsula revealed by Y-STR diversity.

    PubMed

    Alshamali, Farida; Pereira, Luísa; Budowle, Bruce; Poloni, Estella S; Currat, Mathias

    2009-01-01

    Genetic studies have been underway on Arabian Peninsula populations because of their pivotal geographic location for population migration and times of occurrence. To assist in better understanding population dynamics in this region, evidence is presented herein on local population structure in the Arabian Peninsula, based on Y-STR characterisation in four Arabian samples and its comparison in a broad geographical scale. Our results demonstrate that geography played an important role in shaping the genetic structure of the region around the Near-East. Populations are grouped regionally but none of these groups is significantly differentiated from others and all groups merge in the Near-East, in keeping with this important migration corridor for the human species. Focusing on the Arabian Peninsula, we show that Dubai and Oman share genetic affinities with other Near-Eastern populations, while Saudi Arabia and Yemen show a relative distinctive isolated background. Those two populations may have been kept relatively separated from migration routes, maybe due to their location in a desert area.

  16. Precipitation variability in September over the Korean Peninsula during ENSO developing phase

    NASA Astrophysics Data System (ADS)

    Son, Hye-Young; Park, Jong-Yeon; Kug, Jong-Seong

    2016-06-01

    In this study, the relationship between the El Niño-Southern Oscillation (ENSO) and precipitation variability over the Korean Peninsula is investigated. In contrast to the previously-known positive correlation between them during an El Niño developing summer and winter, we found a considerably significant negative correlation in September between Niño3 Sea Surface Temperature and Korean precipitation during ENSO developing phase. The northerly wind is only seen during El Nino developing phase and is part of the cyclonic flow over the subtropical North Pacific. The cyclonic flow over the subtropical North Pacific is induced by the subtropical diabatic heating, which is a peculiar feature during El Niño developing phase. In addition, it is demonstrated that the negative correlation is partly attributed to the tropical cyclone (TC), particularly during La Niña phase. That is, TC tends to pass through Korean Peninsula more frequently during La Niña years, which leads to more precipitation over the Korean Peninsula.

  17. Coccidiosis in European rabbit (Oryctolagus cuniculus algirus) populations in the Iberian Peninsula.

    PubMed

    Silva, Sofia Marques; Ferreira, Catarina; Paupério, Joana; Silva, Rodolfo Miguel; Alves, Paulo Célio; Lemos, Armando

    2015-06-01

    The European rabbit Oryctolagus cuniculus is a keystone species from the Iberian Peninsula where viral diseases have played a prominent role in regulating their populations. Coccidiosis, a parasitic disease caused primarily by Eimeria spp., is also thought to have important negative effects. However, few studies have investigated the impact of coccidia on wild European rabbit populations on the Iberian Peninsula. Here we estimate coccidian prevalence in rabbit faecal samples collected along transects established in two ecological regions. Six Eimeria species, with different pathogenicity, were identified (E. coecicola, E. perforans, E media, E. magna, E. irresidua and E. flavescens). Species diversity varied significantly between regions although mean oocyst excretion levels were generally low in both areas (57.61 s.d.±78.07 and 17.03 s.d.±27.72, oocyst per gram of rabbit faeces). This study is the first to describe the composition of the Eimeria spp. assemblage for wild rabbit populations on the Iberian Peninsula and provides fundamental information for future studies on the potential interaction of viral and parasitic diseases. PMID:26204006

  18. Ground-water resources of the North Beach Peninsula, Pacific County, Washington

    USGS Publications Warehouse

    Tracy, James V.

    1977-01-01

    The anticipated water demand of 425 million gallons per year for the North Brach Peninsula, Pacific County, Wash., can be met by properly developing the ground-water supplies of the area 's water-table aquifer. Of the approximately 77 inches of annual precipitation on the peninsula, an estimated 23 inches is lost to evapotranspiration, and approximately 36 inches is discharged by the water-table aquifer into the ocean and bay. The remaining water either runs off the surface or is leaked to a deeper aquifer that ultimately discharges to the ocean. At least 12 inches of the water that discharges naturally through the aquifer is available for additional development. This quantity of water is approximately equivalent to 860,000 gallons per day. Wells spaced at least 1,000 feet apart along the major axis of the peninsula and pumped at average rates of no more than 80 gallons per minute could ensure that water-level declines do not exceed 6 feet near the wells and 1 foot at the shoreline, thereby preventing seawater intrusion. Lowering of the water table may be beneficial in reducing waterlogging problems, but care must be taken not to lower the levels near cranberry bogs, which require a shallow water table. Treatment of the otherwise good quality water for iron may be required, as about 75 percent of the well water sampled from the aquifer had iron concentrations in excess of limits recommended by the U.S. Environmental Protection Agency. (Woodard-USGS)

  19. Impacts of the north and tropical Atlantic Ocean on the Antarctic Peninsula and sea ice.

    PubMed

    Li, Xichen; Holland, David M; Gerber, Edwin P; Yoo, Changhyun

    2014-01-23

    In recent decades, Antarctica has experienced pronounced climate changes. The Antarctic Peninsula exhibited the strongest warming of any region on the planet, causing rapid changes in land ice. Additionally, in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not declined, but has instead undergone a perplexing redistribution. Antarctic climate is influenced by, among other factors, changes in radiative forcing and remote Pacific climate variability, but none explains the observed Antarctic Peninsula warming or the sea-ice redistribution in austral winter. However, in the north and tropical Atlantic Ocean, the Atlantic Multidecadal Oscillation (a leading mode of sea surface temperature variability) has been overlooked in this context. Here we show that sea surface warming related to th