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Sample records for northeastern pacific margin

  1. Tropical cyclone statistics in the Northeastern Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Vadillo, E. [Universidad Autonoma de Baja California Sur (UABCS), La Paz, Baja California Sur (Mexico); Zaytsev, O. [Centro Interdisciplinario de Ciencias Marinas, Instituto Politecnico Nacional, La Paz, Baja California Sur (Mexico)]. E-mail: ozaytsev@ipn.mx; Morales-Perez, R. [Instituto Mexicano de Tecnologia del Agua (IMTA), Jiutepec, Morelos (Mexico)

    2007-04-15

    The principal area of tropical cyclogenesis in the tropical eastern Pacific Ocean is offshore in the Gulf of Tehuantepec, between 8 and 15 degrees Celsius N, and most of these cyclones move towards the west and northwest during their initial phase. Historical analysis of tropical cyclone data in the Northeastern (NE) Pacific over the last 38 years (from 1966 to 2004) shows a mean of 16.3 tropical cyclones per year, consisting of 8.8 hurricanes 198 and 7.4 tropical storms. The analysis shows great geographical variability of cyclone tracks, and that there were a considerable number of hurricane strikes along the Mexican coast. About 50% of the tropical cyclones formed turned north to northeast. It was rare that any passed further north than 30 degrees Celsius N in latitude because of the cold California Current. Hurricane tracks that affected the NE Pacific may be separated into 5 groups. We compared the historical record of the sea surface temperature (SST), related with the El Nino events with a data set of tropical cyclones, including frequency, intensity, trajectory, and duration. Although the statistical dependence between the frequencies of tropical cyclones of the most abundant categories, 1 and 2, over this region and SST data was not convincing, the percentage of high intensity hurricanes and hurricanes with a long life-time (greater than 12 days) was more during El Nino years than in non-El Nino years. [Spanish] La principal region de la formacion de ciclones en el oceano Pacifico Este es el Golfo de Tehuantepec, entre los 8 y los 15 grados Celsius N. En su fase inicial los ciclones se mueven hacia el oeste y el noroeste. El analisis historico de los ciclones que se han generado durante los ultimos 38 anos (de 1966 a 2004) muestra un promedio de 16.2 ciclones por ano, consistentes en 8.8 huracanes y 7.4 tormentas tropicales. El analisis muestra una gran variabilidad geografica en la trayectoria de los ciclones, de los cuales un gran numero impacta las

  2. Integrated geophysical study of the northeastern margin of Tibetan Plateau

    Science.gov (United States)

    Shi, L.; Meng, X.; Guo, L.

    2011-12-01

    Tibetan Plateau, the so-called "Roof of the World", is a direct consequence of collision of the Indian plate with the Eurasian plate starting in the early Cenozoic time. The continent-continent collision is still going on. The northeastern margin of Tibetan Plateau is the front part of the Tibetan Plateau extends to mainland and favorable area for studying uplift and deformation of the Tibetan Plateau. In the past decades, a variety of geophysical methods were conducted to study geodynamics and geological tectonics of this region. We assembled satellite-derived free-air gravity anomalies with a resolution of one arc-minute from the Scripps Institution of Oceanography, and reduced them to obtain Complete Bouguer Gravity Anomalies. Then we gridded Complete Bouguer Gravity Anomalies on a regular grid, and subsequently processed them with the preferential continuation method to attenuate high-frequency noise and analyzed regional and residual anomalies. We also calculated tilt-angle derivative of Complete Bouguer Gravity Anomalies to derive clearer geological structures with more details. Then we calculated the depth distribution of the Moho discontinuity surface in this area by 3D density interface inversion. From the results of preliminary processing, we analyzed the main deep faults and geological tectonics in this region. We extracted seven important profiles' data of Complete Bouguer Gravity Anomalies in this area, and then did forward modeling and inversion on each profile with constraints of geological information and other geophysical data. In the future, we will perform 3D constrained inversion of Complete Bouguer Gravity Anomalies in this region for better understanding deep structure and tectonics of the northeastern margin of Tibetan Plateau. Acknowledgment: We acknowledge the financial support of the SinoProbe project (201011039), the Fundamental Research Funds for the Central Universities (2010ZY26 2011PY0184), and the National Natural Science Foundation

  3. Recent progress in Pacific-Asian Marginal Seas (PAMS) studies

    Science.gov (United States)

    Matsuno, Takeshi; Hirose, Naoki; Zhang, Jing; Cho, Yang-Ki; Chen, Dake; Yuan, Dongliang; Hung, Chin-Chang; Jan, Sen

    2017-07-01

    Marginal seas which represent the buffer zones between land and the pelagic ocean are being increasingly influenced by human activity. The role of the marginal seas is important for many reasons, among which are biological resources and climate change. In East Asia, we have marginal seas between the Asian Continent and the Pacific Ocean, where various countries and areas form complicated territories and EEZ. To understand the marine environment of marginal seas, international cooperative scientific activities are necessary, and it is essential to share the latest information and knowledge.

  4. Otolith patterns of rockfishes from the northeastern Pacific.

    Science.gov (United States)

    Tuset, Victor M; Imondi, Ralph; Aguado, Guillermo; Otero-Ferrer, José L; Santschi, Linda; Lombarte, Antoni; Love, Milton

    2015-04-01

    Sagitta otolith shape was analysed in twenty sympatric rockfishes off the southern California coast (Northeastern Pacific). The variation in shape was quantified using canonical variate analysis based on fifth wavelet function decomposition of otolith contour. We selected wavelets because this representation allow the identifications of zones or single morphological points along the contour. The entire otoliths along with four subsections (anterior, ventral, posterodorsal, and anterodorsal) with morphological meaning were examined. Multivariate analyses (MANOVA) showed significant differences in the contours of whole otolith morphology and corresponding subsection among rockfishes. Four patterns were found: fusiform, oblong, and two types of elliptic. A redundancy analysis indicated that anterior and anterodorsal subsections contribute most to define the entire otolith shape. Complementarily, the eco-morphological study indicated that the depth distribution and strategies for capture prey were correlated to otolith shape, especially with the anterodorsal zone. © 2014 Wiley Periodicals, Inc.

  5. Genetic data for groundfish - Genetics and genomics of northeastern Pacific groundfish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Conduct genetic analyses of groundfish in the northeastern Pacific, with a focus on population genetics and genomics of rockfishes and sablefish. Genetic data for...

  6. Late Palaeozoic to Neogene Geodynamic Evolution of the north-eastern Oman Margin.

    NARCIS (Netherlands)

    Immenhauser, A.M.; Schreurs, G; Oterdoom, H; Hartmann, B

    2000-01-01

    When the highlands of Arabia were still covered with an ice shield in the latest Carboniferous/Early Permian period, separation of Gondwana started. This led to the creation of the Batain basin (part of the early Indian Ocean), off the northeastern margin of Oman. The rifting reactivated an

  7. Educational Marginalization: Examining Challenges and Possibilities for Improving Educational Outcomes in Northeastern Kenya

    Directory of Open Access Journals (Sweden)

    Nathern S. A. Okilwa

    2015-11-01

    Full Text Available As a developing country in sub-Saharan Africa, Kenya has fared comparatively well in educating its young people. The new constitution of Kenya and various acts of parliament identify education as a fundamental human right and mandates the government to provide basic education for all. Consistent with the government’s Vision 2030, most political, religious, and civil society leaders recognize education as critical to individuals attaining full potential and then contributing to nation building. However, educational access and equity remain quite elusive in rural and less economically viable areas, such as northeastern. The region and its people have been marginalized for many years, dating back to the colonial era and still remain very undeveloped, under-resourced, and impoverished. Given the endemic discrimination and marginalization of the nomadic people of northeastern Kenya, harsh geographic conditions, constant migration of the people, and heightened insecurity in the region, there is limited data, information, and understanding of these people’s life experiences. The purpose of this article is to highlight these challenges that minimize educational opportunities for young people in northeastern Kenya by reviewing the historic political isolation and marginalization, sociocultural practices (e.g., nomadic lifestyle, female genital mutilation, resource deprivation and poverty, harsh geographic conditions, and poor infrastructure. Additionally, the article examines emerging efforts and opportunities (e.g., government and non-government organizations to improve educational opportunities in the region through the devolution framework in the new Constitution of Kenya, constituency development funds (CDF, mobile schools, and boarding schools.

  8. Late Cretaceous Breakup of the Pacific Margin of Southern Mexico

    Science.gov (United States)

    Guerrero-Garcia, J. C.; Herrero-Bervera, E.

    2006-12-01

    As geological, geophysical and geochemical evidence keeps accumulating over the years, there seems to be a growing general acceptance that the Chortis block (nuclear Central America) occupied a position further to the NW along the present-day margin of southwestern Mexico, sometime between Early Jurassic and Neogene time. The controversy resides no longer in the sense of motion along the coast but on the timing of events and in the latitude that the Chortis block occupied at the time of detachment. Previous studies mainly confined to the northern margin of the Chortis block, confirmed a left-lateral displacement of 130 km in Neogene time. Further studies made northwestward along the Mexican coast provided a better understanding of magmatic and metamorphic processes in the area, and suggested times of detachment increased to 30 Ma (Wadge and Burke, 1983), 40 Ma (Schaaf and others, 1995), and 66 Ma (Herrmann and others, 1994). The pre- detachment westernmost position of the block has changed, depending on the model chosen, from Puerto Vallarta and beyond, to the current position. We contend that several indicators, namely: (1) the truncated nature of the Pacific coast of SW Mexico; (2) the genesis of the Kula-Farallon ridge at 85 Ma; (3) the 2,600 km of northward transport of Baja British Columbia from the present-day latitude of the Baja California Peninsula, beginning at 85 Ma; (4) the paleomagnetic counterclockwise rotations of areas both in the Chortis block and along the Mexican coast, during Late Cretaceous-Paleogene time, and (5) the systematic NW-SE decrease of radiometric dates beginning at 85 Ma in Puerto Vallarta, point to this time and region for the onset of strike- slip drifting of the Chortis block toward its current position.

  9. Archaeofaunal insights on pinniped-human interactions in the northeastern Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Gifford-Gonzales, D; Newsome, S; Koch, P; Guilderson, T; Snodgrass, J; Burton, R

    2004-02-07

    Human exploitation of pinnipeds has considerable antiquity but shows increasing impacts on population numbers in the Holocene. Pinnipeds are a rich source of fat as well as protein. A few well-documented cases of regional extirpation of seals and sea lions by non-industrial peoples exist. The northeastern Pacific region, from southern California to Alaska, has yielded archaeological evidence for distributions and abundances of eared seals that differs markedly from historically documented biogeography. This is especially true of the northern fur seal (Callorhinus ursinus), among the most common pinnipeds in many archaeological sites from the Santa Barbara Channel area through to Kodiak Islands. This chapter reviews contemporary eared seal biogeography, evidence for the earlier timing and extent, of occurrence of northern fur seals along the northeastern Pacific coast, zooarchaeological and isotopic evidence for their foraging and probable maintenance of rookeries in lower latitudes, and for their disappearance from the southernmost part of their ancient distribution well before European contact. It also reviews ongoing debates over the behavioral ecology of ancient fur seals and over humans role in contributing to their disappearance.

  10. Wintertime phytoplankton bloom in the Subarctic Pacific supported by continental margin iron

    International Nuclear Information System (INIS)

    Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus, Matthew A.; Waychunas, Glenn A.; Fung, Inez

    2004-01-01

    Heightened biological activity was observed in February 1996 in the high-nutrient low-chlorophyll (HNLC) subarctic North Pacific Ocean, a region that is thought to be iron-limited. Here we provide evidence supporting the hypothesis that Ocean Station Papa (OSP) in the subarctic Pacific received a lateral supply of particulate iron from the continental margin off the Aleutian Islands in the winter, coincident with the observed biological bloom. Synchrotron X-ray analysis was used to describe the physical form, chemistry, and depth distributions of iron in size fractionated particulate matter samples. The analysis reveals that discrete micron-sized iron-rich hotspots are ubiquitous in the upper 200m at OSP, more than 900km from the closest coast. The specifics of the chemistry and depth profiles of the Fe hot spots trace them to the continental margins. We thus hypothesize that iron hotspots are a marker for the delivery of iron from the continental margin. We confirm the delivery of continental margin iron to the open ocean using an ocean general circulation model with an iron-like tracer source at the continental margin. We suggest that iron from the continental margin stimulated a wintertime phytoplankton bloom, partially relieving the HNLC condition

  11. The continental margin is a key source of iron to the HNLC North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.J.; Bishop, J.K.B

    2008-01-15

    Here we show that labile particulate iron and manganese concentrations in the upper 500m of the Western Subarctic Pacific, an iron-limited High Nutrient Low Chlorophyll (HNLC) region, have prominent subsurface maxima between 100-200 m, reaching 3 nM and 600 pM, respectively. The subsurface concentration maxima in particulate Fe are characterized by a more reduced oxidation state, suggesting a source from primary volcagenic minerals such as from the Kuril/Kamchatka margin. The systematics of these profiles suggest a consistently strong lateral advection of labile Mn and Fe from redox-mobilized labile sources at the continental shelf supplemented by a more variable source of Fe from the upper continental slope. This subsurface supply of iron from the continental margin is shallow enough to be accessible to the surface through winter upwelling and vertical mixing, and is likely a key source of bioavailable Fe to the HNLC North Pacific.

  12. Future coral reef habitat marginality: Temporal and spatial effects of climate change in the Pacific basin

    Science.gov (United States)

    Guinotte, J.M.; Buddemeier, R.W.; Kleypas, J.A.

    2003-01-01

    Marginal reef habitats are regarded as regions where coral reefs and coral communities reflect the effects of steady-state or long-term average environmental limitations. We used classifications based on this concept with predicted time-variant conditions of future climate to develop a scenario for the evolution of future marginality. Model results based on a conservative scenario of atmospheric CO2 increase were used to examine changes in sea surface temperature and aragonite saturation state over the Pacific Ocean basin until 2069. Results of the projections indicated that essentially all reef locations are likely to become marginal with respect to aragonite saturation state. Significant areas, including some with the highest biodiversity, are expected to experience high-temperature regimes that may be marginal, and additional areas will enter the borderline high temperature range that have experienced significant ENSO-related bleaching in the recent past. The positive effects of warming in areas that are presently marginal in terms of low temperature were limited. Conditions of the late 21st century do not lie outside the ranges in which present-day marginal reef systems occur. Adaptive and acclimative capabilities of organisms and communities will be critical in determining the future of coral reef ecosystems.

  13. Patterns of Mass Mortality among Rocky Shore Invertebrates across 100 km of Northeastern Pacific Coastline.

    Directory of Open Access Journals (Sweden)

    Laura J Jurgens

    Full Text Available Mass mortalities in natural populations, particularly those that leave few survivors over large spatial areas, may cause long-term ecological perturbations. Yet mass mortalities may remain undocumented or poorly described due to challenges in responding rapidly to unforeseen events, scarcity of baseline data, and difficulties in quantifying rare or patchily distributed species, especially in remote or marine systems. Better chronicling the geographic pattern and intensity of mass mortalities is especially critical in the face of global changes predicted to alter regional disturbance regimes. Here, we couple replicated post-mortality surveys with preceding long-term surveys and historical data to describe a rapid and severe mass mortality of rocky shore invertebrates along the north-central California coast of the northeastern Pacific Ocean. In late August 2011, formerly abundant intertidal populations of the purple sea urchin (Strongylocentrotus purpuratus, a well-known ecosystem engineer, and the predatory six-armed sea star (Leptasterias sp. were functionally extirpated from ~100 km of coastline. Other invertebrates, including the gumboot chiton (Cryptochiton stelleri the ochre sea star (Pisaster ochraceus, and subtidal populations of purple sea urchins also exhibited elevated mortality. The pattern and extent of mortality suggest the potential for long-term population, community, and ecosystem consequences, recovery from which may depend on the different dispersal abilities of the affected species.

  14. Map showing bottom topography of the Pacific Continental Margin, Cape Mendocino to Point Conception

    Science.gov (United States)

    Chase, T.E.; Wilde, Pat; Normark, W.R.; Evenden, G.I.; Miller, C.P.; Seekins, B.A.; Young, J. D.; Grim, M.S.; Lief, C.J.

    1992-01-01

    All contours, geographic outlines, and political boundaries shown on this map of the bottom topography, or bathymetry, of the Pacific continental margin between 34? and 41? N. latitudes were plotted from digital data bases in the library of the U.S. Geological Survey (USGS)-National Oceanic and Atmospheric Administration (NOAA) Joint Office for Mapping and Research (JOMAR). These digital data were obtained and compiled from many sources; consequently, data quality varies within particular data bases as well as from one data base to another.

  15. Living on the margin: dealing with climate change in remote Pacific islands

    DEFF Research Database (Denmark)

    Birk, Thomas Ladegaard Kümmel

    with the marginal socioeconomic and geographical position of the island groups within Solomon Islands along with internal factors, not the least population growth and pressure on natural resources. This gives rise to both push and pull factors contributing to the widespread migration of islanders, in particular......In the global debate of climate change the fate of small islands states has played a significant role, in spite of the relatively few people affected. This thesis examines how such islands, here mainly represented by two atoll groups in remote parts of Solomon Islands in the Southwest Pacific, Reef...

  16. Storage, patterns, and control of soil organic carbon and nitrogen in the northeastern margin of the Qinghai–Tibetan Plateau

    International Nuclear Information System (INIS)

    Liu Wenjie; Chen Shengyun; Qin Xiang; Zhou Zhaoye; Sun Weijun; Ren Jiawen; Qin Dahe; Baumann, Frank; Scholten, Thomas; Zhang Tongzuo

    2012-01-01

    This study tested the hypothesis that soil organic carbon (SOC) and total nitrogen (TN) spatial distributions show clear relationships with soil properties and vegetation composition as well as climatic conditions. Further, this study aimed to find the corresponding controlling parameters of SOC and TN storage in high-altitude ecosystems. The study was based on soil, vegetation and climate data from 42 soil pits taken from 14 plots. The plots were investigated during the summers of 2009 and 2010 at the northeastern margin of the Qinghai–Tibetan Plateau. Relationships of SOC density with soil moisture, soil texture, biomass and climatic variables were analyzed. Further, storage and vertical patterns of SOC and TN of seven representative vegetation types were estimated. The results show that significant relationships of SOC density with belowground biomass (BGB) and soil moisture (SM) can be observed. BGB and SM may be the dominant factors influencing SOC density in the topsoil of the study area. The average densities of SOC and TN at a depth of 1 m were about 7.72 kg C m −2 and 0.93 kg N m −2 . Both SOC and TN densities were concentrated in the topsoil (0–20 cm) and fell exponentially as soil depth increased. Additionally, the four typical vegetation types located in the northwest of the study area were selected to examine the relationship between SOC and environmental factors (temperature and precipitation). The results indicate that SOC density has a negative relationship with temperature and a positive relationship with precipitation diminishing with soil depth. It was concluded that SOC was concentrated in the topsoil, and that SOC density correlates well with BGB. SOC was predominantly influenced by SM, and to a much lower extent by temperature and precipitation. This study provided a new insight in understanding the control of SOC and TN density in the northeastern margin of the Qinghai–Tibetan Plateau. (letter)

  17. Storage, patterns, and control of soil organic carbon and nitrogen in the northeastern margin of the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Liu, Wenjie; Chen, Shengyun; Qin, Xiang; Baumann, Frank; Scholten, Thomas; Zhou, Zhaoye; Sun, Weijun; Zhang, Tongzuo; Ren, Jiawen; Qin, Dahe

    2012-09-01

    This study tested the hypothesis that soil organic carbon (SOC) and total nitrogen (TN) spatial distributions show clear relationships with soil properties and vegetation composition as well as climatic conditions. Further, this study aimed to find the corresponding controlling parameters of SOC and TN storage in high-altitude ecosystems. The study was based on soil, vegetation and climate data from 42 soil pits taken from 14 plots. The plots were investigated during the summers of 2009 and 2010 at the northeastern margin of the Qinghai-Tibetan Plateau. Relationships of SOC density with soil moisture, soil texture, biomass and climatic variables were analyzed. Further, storage and vertical patterns of SOC and TN of seven representative vegetation types were estimated. The results show that significant relationships of SOC density with belowground biomass (BGB) and soil moisture (SM) can be observed. BGB and SM may be the dominant factors influencing SOC density in the topsoil of the study area. The average densities of SOC and TN at a depth of 1 m were about 7.72 kg C m-2 and 0.93 kg N m-2. Both SOC and TN densities were concentrated in the topsoil (0-20 cm) and fell exponentially as soil depth increased. Additionally, the four typical vegetation types located in the northwest of the study area were selected to examine the relationship between SOC and environmental factors (temperature and precipitation). The results indicate that SOC density has a negative relationship with temperature and a positive relationship with precipitation diminishing with soil depth. It was concluded that SOC was concentrated in the topsoil, and that SOC density correlates well with BGB. SOC was predominantly influenced by SM, and to a much lower extent by temperature and precipitation. This study provided a new insight in understanding the control of SOC and TN density in the northeastern margin of the Qinghai-Tibetan Plateau.

  18. Relationship between the Northern Pacific Gyre Oscillation and tree-ring cellulose oxygen isotopes in northeastern Japan

    Science.gov (United States)

    Sakashita, Wataru; Miyahara, Hiroko; Yokoyama, Yusuke; Aze, Takahiro; Obrochta, Stephen P.; Nakatsuka, Takeshi

    2017-12-01

    The North Pacific Gyre Oscillation (NPGO) significantly imprints on hydrological fluctuations of the East Asian summer monsoon (EASM) region, but this has not yet been observed in proxy-based hydroclimate reconstructions. This study reports a tree-ring cellulose oxygen isotope (δ18O) record from northeastern Japan spanning A.D. 1927-2010, overlapping with instrumental data, which we analyzed to determine if tree-ring δ18O in northeastern Japan records a signal consistent with the NPGO. Our results indicate that the tree-ring δ18O has a significant negative correlation with May-June (MJ) precipitation, as well as with short-term MJ relative humidity variation. Time-lagged temporal-domain comparisons indicate that the tree-ring δ18O is significantly correlated with the following year March-April (MA) and MJ NPGO index before the North Pacific climate transition in the late 1980s, particularly on decadal timescales. These relationships between our tree-ring δ18O and the climate patterns in the North Pacific are consistent with the actual early-summer precipitation. Spatial spring and early-summer sea-surface temperature anomalies exhibit a NPGO-like pattern in the following year. Spatial early-summer sea-level pressure anomalies also indicate North Pacific Oscillation (NPO) like patterns in the western North Pacific. These results suggest a lagged response of the NPGO to the EASM climate changes, and tree-ring δ18O in northeast Japan has a potential linkage with NPGO index from winter to early summer of the following year.

  19. Deep Structure and Evolution of the Northeastern Gulf of Aden Margin From Wide-Angle Seismic and Thermomechanical Modeling

    Science.gov (United States)

    Watremez, L.; Leroy, S.; Rouzo, S.; D'Acremont, E.; Burov, E. B.

    2009-12-01

    The Encens survey wide-angle and gravity data (Leroy et al., Feb. March 2006) allow us to determine the deep structure of the northeastern Gulf of Aden non-volcanic passive margin. The Gulf of Aden is a young oceanic basin. Its accretion began at least 17.6 Ma ago. Its current geometry shows 1st and 2nd order segmentation. Our study focus on the second order Ashawq-Salalah segment. We studied six wide-angle seismic (WAS) and gravity profiles (three along and three across the margin). Modeling of the WAS and gravity data gives insights on the first and second orders structures : (1) Continental thinning is abrupt (15-20 km thinning along 50-100 km distance). It is accommodated by four tilted blocks. (2) The OCT is narrow (15 km wide). Its geometry is determined by the velocity models: oceanic-type upper-crust (4.5 km/s) and continental-type lower-crust (> 6.5 km/s). (3) The thickness of the oceanic crust decreases from West (10 km) to East (5.5 km). This pattern is probably linked to a variation of magma supply along the paleo-slow-spreading ridge axis. (4) A 5 km thick intermediate velocity body (7.6 to 7.8 km/s) is present at the crust-mantle interface below the margin. It is interpreted as post-rift underplated, or partly intruded, mafic material. This interpretation is consistent with the presence of a volcano evidenced by heat flow measurement and multichannel seismic reflection (Encens surveys). The studied segment is mainly characterized by abrupt continental thinning and narrow OCT. Moreover, this non-volcanic passive margin is affected by post-rift volcanism evidenced by the mafic body. We then suggest that the evolution of non-volcanic passive margins may be influenced by post-rift thermal anomalies. We will compare these above results with thermomechanical models in order to constrain the margin evolution and factors leading to the Gulf of Aden formation. Modeling is processed using Para(o)voz/Flamar code. This allows us to experiment the influence of

  20. Iodine-129 concentrations in marginal seas of the North Pacific and Pacific-influenced waters of the Arctic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Lee W.; Grebmeier, Jacqueline M. [Tennessee Univ., Dept. of Ecology and Evolutionary Biology, Knoxville, TN (United States); Hong, Gi H. [Korea Ocean Research and Development Inst., Seoul (Korea); Beasley, Tom M. [US Dept. of Energy, New York, NY (United States)

    2001-07-01

    Water sampling during the 1993 IV Russian-US Joint Expedition to the Bering and Chukchi Seas (BERPAC) indicates that Pacific Ocean burdens of the long-lived radionuclide {sup 129}I are relatively low in the Pacific-influenced Arctic, particularly compared to high latitude water influenced by the North Atlantic. These low concentrations occur despite the presence of potential submerged anthropogenic sources in the East Sea (Sea of Japan), and in the northwest Pacific Ocean, east of the Kamchatka Peninsula. The concentration of {sup 129}I entering the Arctic Ocean through Bering Strait, {approx}0.7x10{sup 8} atoms kg {sup -1}, is only slightly higher than observed in deep Pacific water. Similar concentrations (0.44-0.76x10{sup 8}atoms kg{sup -1}) measured in Long Strait indicate no significant transfer of {sup 129}I eastward into the Chukchi Sea in the Siberian Coastal Current from the Siberian marginal seas to the west, However, the concentrations reported here are more than an order to magnitude higher than the Bering Strait input concentration estimated (1.0x10{sup 6}atoms kg{sup -1}) from bomb fallout mass balances, which supports other existing evidence for a significant atmospheric deposition term for this radionuclide in surface ocean waters. Near-bottom water samples collected in productive waters of the Bering and Chukchi Seas also suggest that sediment regeneration may locally elevate {sup 129}I concentrations, and impact its utility as a water mass tracer. As part of this study, two deep {sup 129}I profiles were also measured in the East Sea in 1993-1994. The near-surface concentration of {sup 129}I ranged from 0.12 to 0.31x10{sup 8}atoms kg{sup -1}. The {sup 129}I concentration showed a steady decrease with depth, although because of active deep water ventilation, the entire 3000 m water column exceeded natural concentrations of the radionuclide. Atom ratios of {sup 129}I/{sup 137}Cs in the East Sea also suggest an excess of {sup 129}I above bomb fallout

  1. Robust Performance of Marginal Pacific Coral Reef Habitats in Future Climate Scenarios.

    Science.gov (United States)

    Freeman, Lauren A

    2015-01-01

    Coral reef ecosystems are under dual threat from climate change. Increasing sea surface temperatures and thermal stress create environmental limits at low latitudes, and decreasing aragonite saturation state creates environmental limits at high latitudes. This study examines the response of unique coral reef habitats to climate change in the remote Pacific, using the National Center for Atmospheric Research Community Earth System Model version 1 alongside the species distribution algorithm Maxent. Narrow ranges of physico-chemical variables are used to define unique coral habitats and their performance is tested in future climate scenarios. General loss of coral reef habitat is expected in future climate scenarios and has been shown in previous studies. This study found exactly that for most of the predominant physico-chemical environments. However, certain coral reef habitats considered marginal today at high latitude, along the equator and in the eastern tropical Pacific were found to be quite robust in climate change scenarios. Furthermore, an environmental coral reef refuge previously identified in the central south Pacific near French Polynesia was further reinforced. Studying the response of specific habitats showed that the prevailing conditions of this refuge during the 20th century shift to a new set of conditions, more characteristic of higher latitude coral reefs in the 20th century, in future climate scenarios projected to 2100.

  2. Robust Performance of Marginal Pacific Coral Reef Habitats in Future Climate Scenarios.

    Directory of Open Access Journals (Sweden)

    Lauren A Freeman

    Full Text Available Coral reef ecosystems are under dual threat from climate change. Increasing sea surface temperatures and thermal stress create environmental limits at low latitudes, and decreasing aragonite saturation state creates environmental limits at high latitudes. This study examines the response of unique coral reef habitats to climate change in the remote Pacific, using the National Center for Atmospheric Research Community Earth System Model version 1 alongside the species distribution algorithm Maxent. Narrow ranges of physico-chemical variables are used to define unique coral habitats and their performance is tested in future climate scenarios. General loss of coral reef habitat is expected in future climate scenarios and has been shown in previous studies. This study found exactly that for most of the predominant physico-chemical environments. However, certain coral reef habitats considered marginal today at high latitude, along the equator and in the eastern tropical Pacific were found to be quite robust in climate change scenarios. Furthermore, an environmental coral reef refuge previously identified in the central south Pacific near French Polynesia was further reinforced. Studying the response of specific habitats showed that the prevailing conditions of this refuge during the 20th century shift to a new set of conditions, more characteristic of higher latitude coral reefs in the 20th century, in future climate scenarios projected to 2100.

  3. Morphology and tectonics of Mahanadi Basin, northeastern continental margin of India from geophysical studies

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Subrahmanyam, A.S.; Murty, G.P.S.; Murthy, K.S.R.

    The bathymetry, total intensity magnetic and satellite free-air gravity data over the eastern continental margin of India between the latitudes 18 degrees 30 minutes N and 20 degrees N within the water depths of 25-2300 m (between Paradip...

  4. Life and death of the resurrection plate: Evidence for its existence and subduction in the northeastern Pacific in Paleocene-Eocene time

    Science.gov (United States)

    Haeussler, P.J.; Bradley, D.C.; Wells, R.E.; Miller, M.L.

    2003-01-01

    Onshore evidence suggests that a plate is missing from published reconstructions of the northeastern Pacific Ooean in Paleocene- Eocene time. The Resurrection plate, named for the Resurrection Peninsula ophiolite near Seward, Alaska, was located east of the Kula plate and north of the Farallon plate. We interpret coeval near-trench magmatism in southern Alaska and the Cascadia margin as evidence for two slab windows associated with trench-ridge-trench (TRT) triple junctions, which formed the western and southern boundaries of the Resurrection plate. In Alaska, the Sanak-Baranof belt of near-trench intrusions records a west-to-east migration, from 61 to 50 Ma, of the northern TRT triple junction along a 2100-km-long section of coastline. In Oregon, Washington, and southern Vancouver Island, voluminous basaltic volcanism of the Siletz River Volcanics, Crescent Formation, and Metchosin Volcanics occurred between ca. 66 and 48 Ma. Lack of a clear age progression of magmatism along the Cascadia margin suggests that this southern triple junction did not migrate significantly. Synchronous near-trench magmatism from southeastern Alaska to Puget Sound at ca. 50 Ma documents the middle Eocene subduction of a spreading center, the crest of which was subparallel to the margin. We interpret this ca. 50 Ma event as recording the subduction-zone consumption of the last of the Resurrection plate. The existence and subsequent subduction of the Resurrection plate explains (1) northward terrane transport along the southeastern Alaska-British Columbia margin between 70 and 50 Ma, synchronous with an eastward-migrating triple junction in southern Alaska; (2) rapid uplift and voluminous magmatism in the Coast Mountains of British Columbia prior to 50 Ma related to subduction of buoyant, young oceanic crust of the Resurrection plate; (3) cessation of Coast Mountains magmatism at ca. 50 Ma due to cessation of subduction, (4) primitive mafic magmatism in the Coast Mountains and Cascade

  5. Sedimentary evolution of the Pliocene and Pleistocene Ebro margin, northeastern Spain

    Science.gov (United States)

    Alonso, B.; Field, M.E.; Gardner, J.V.; Maldonado, A.

    1990-01-01

    The Pliocene and Pleistocene deposits of the Spanish Ebro margin overlie a regional unconformity and contain a major disconformity. These unconformities, named Reflector M and Reflector G, mark the bases of two seismic sequences. Except for close to the upper boundary where a few small channel deposits are recognized, the lower sequence lacks channels. The upper sequence contains nine channel-levee complexes as well as base-of-slope aprons that represent the proximal part of the Valencia turbidite system. Diverse geometries and variations in seismic units distinguish shelf, slope, base-of-slope and basin-floor facies. Four events characterize the late Miocene to Pleistocene evolution of the Ebro margin: (a) formation of a paleodrainage system and an extensive erosion-to-depositional surface during the latest Miocene (Messinian), (b) deposition of hemipelagic units during the early Pliocene, (c) development of canyons during the late Pliocene to early Pleistocene, and (d) deposition of slope wedges, channel-levee complexes, and base-of-slope aprons alternating with hemipelagic deposition during the Pleistocene. Sea-level fluctuations influenced the evolution of the sedimentary sequences of the Ebro margin, but the major control was the sediment supply from the Ebro River. ?? 1990.

  6. Major zircon megacryst suites of the Indo-Pacific lithospheric margin (ZIP) and their petrogenetic and regional implications

    Science.gov (United States)

    Sutherland, Lin; Graham, Ian; Yaxley, Gregory; Armstrong, Richard; Giuliani, Gaston; Hoskin, Paul; Nechaev, Victor; Woodhead, Jon

    2016-04-01

    Zircon megacrysts (± gem corundum) appear in basalt fields of Indo-Pacific origin over a 12,000 km zone (ZIP) along West Pacific continental margins. Age-dating, trace element, oxygen and hafnium isotope studies on representative zircons (East Australia-Asia) indicate diverse magmatic sources. The U-Pb (249 to 1 Ma) and zircon fission track (ZFT) ages (65 to 1 Ma) suggest thermal annealing during later basalt transport, with slab subduction.

  7. Increase in Export Production in the Marginal Seas of the Northwestern Pacific in Response to Anthropogenic N Input

    Science.gov (United States)

    Lee, K.; Ko, Y. H.; Moon, J. Y.

    2017-12-01

    The relative abundance of nitrate (N) over phosphorus (P) has increased significantly over the period since 1980 in the marginal seas (Yellow, East China and East seas) bordering the northwestern Pacific Ocean, located downstream of the populated and industrialized Asian continent. Analysis of datasets for anthropogenic N input, satellite chlorophyll-a (Chl-a), and seawater nutrient data ( 200,000 data points) reveal that transport of N originating from China has been responsible for enhancements of Chl-a in the marginal seas of the northwestern Pacific Ocean. In particular, the contribution of anthropogenic N to new production in these marginal seas is expected to grow considerably in the coming decades. This anthropogenically driven increase in the N content may potentially lead to a long-term change of these marginal seas from being N-limited to P-limited.

  8. Transport process of Pu isotope in marginal seas of the western North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masatoshi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, 036-8564, Aomori (Japan); Zheng, Jian [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, 263-8555, Chiba (Japan)

    2014-07-01

    Significant quantities of Pu isotopes have been released into the marine environment as the result of atmospheric nuclear weapons testing. Most radionuclides globally dispersed in atmospheric nuclear weapons testing were released into the environment during the 1950's and 1960's. In the western North Pacific Ocean, the principal source can be further distinguished as two distinct sources of Pu: close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds (PPG) in the Marshall Islands and global stratospheric fallout. Since the {sup 240}Pu/{sup 239}Pu atom ratio is characteristic for the Pu emission source, information on Pu isotopic signature is very useful to better understand the transport process in the oceans and to identify the sources of Pu. The mean atom ratio of {sup 240}Pu/{sup 239}Pu from the global stratospheric fallout is 0.180 ±0.014 based on soil sample data, whereas that from close-in tropospheric fallout from the PPG is 0.33 - 0.36. The {sup 240}Pu/{sup 239}Pu atom ratios in seawater samples collected in marginal seas of the western North Pacific Ocean will provide important and useful data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The objectives of this study were to measure the {sup 239+240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios in seawater from the Sea of Okhotsk, Japan Sea, South China Sea and Sulu Sea and to discuss the transport process of Pu. Large-volume seawater samples (250 L each) were collected from the surface to the bottom in marginal seas of the western North Pacific Ocean with acoustically triggered quadruple PVC sampling bottles during the R/V Hakuho-Maru cruise. The {sup 239}Pu and {sup 240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. In

  9. Serpentine bodies in the forearcs of western Pacific convergent margins: Origin and associated fluids

    Science.gov (United States)

    Fryer, Patricia; Mottl, Michael; Johnson, Lynn; Haggerty, Janet; Phipps, Steven; Maekawa, Hirokazu

    Deposits from serpentine seamounts on the forearc regions of the Mariana and Izu-Bonin convergent plate margins are very similar to some serpentine bodies found in exotic forearc terranes on land. Ideas regarding the formation of serpentine bodies have undergone a profound change as a consequence of seafloor mapping, submersible investigations, and scientific ocean drilling efforts in the western Pacific. These seamounts are of two end-member types, serpentine mud volcanoes and serpentine horst blocks. Various composites of these two end-member types exist. The seamounts are associated with faulting in these forearcs and fluids escaping from conduits or fissures within the edifices have a slab origin. The timing of formation of the serpentine is not known with certainty, but the presence of serpentine in sediments of middle Eocene age recovered from the Mariana forearc suggests that formation of sedimentary serpentine deposits took place at least since that time. Although care must be taken not to generalize the nature of the deposits observed on these seamounts to serpentinite bodies world-wide, it is clear that bodies of sedimentary serpentinite that originally formed in active convergence zones are far more abundant than previously thought. The study of forearc metamorphism and the fluids associated with these seamounts will help to explain the problem of mass chemical balance at convergent margins.

  10. The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae).

    Science.gov (United States)

    Campos, Ernesto

    2016-09-23

    New bivalve host records for four pinnotherid crabs of the Mexican Pacific are reported: Fabia subquadrata Dana, 1851, in Modiolus capax (Conrad, 1837); Opisthopus transversus Rathbun, 1893, in Tivela stultorum (Mawe, 1823); Pinnaxodes gigas (Green, 1992), in Pinna rugosa (Sowerby, 1835), and Panopea generosa Gould, 1850; and Tumidotheres margarita (Smith, 1870), in Nodipecten subnodosus (Sowerby, 1835). The southernmost distribution of F. subquadrata is extended to about 600 km along the west coast of the Baja California Peninsula; the distribution of P. gigas is extended outside the Gulf of California more than 1000 km north to San Quintín, on the west coast of Baja California; and the range of T. margarita is restricted on the west coast of Baja California to Scammon´s Lagoon, Baja California Sur and Playa Kino Viejo, Sonora in the central region of the Gulf of California, Mexico to Panama. Based on the new material, new information on taxonomy, ecology, and life history is provided for each of these species. Pinnotheres nudus Holmes, 1895 is restored as a valid species and is removed from its synonymy with O. transversus. An updated checklist with remarks on zoogeography for the 60 pinnotherid species, included in 23 genera, of the northeastern Pacific region (Alaska to the Mexican tropical Pacific) is given.

  11. Overview on the Plate Boundaries Along the Western Mexican Pacific Margin

    Science.gov (United States)

    Mortera-Gutierrez, C. A.; Bandy, W. L.; Michaud, F.; Ortega Ramírez, J.

    2013-05-01

    The cinematic of the Pacific, Rivera and Cocos oceanic plates have a significant impact on the subduction process and seismic cycles occurring along the western Mexican Pacific margin of the North American and Caribbean plates. Sections of Pacific (PAC), Rivera (RIV), Cocos (COC), North American (NAM) and Caribbean (CAB) plate boundaries along the western margin of Mexico are not well constrained. From north to south: the transform-rift system at Gulf of California has been generally considered as part of PAC-NAM plate boundary. However results of the FAMEX cruise at 2002 evidenced that Tosco-Abreojos Fault System along the western margin of Baja California Peninsula is active. Should this tectonic structure be considered as a plate boundary? At the RIV plate northern corner (including Mazatlan Basin), the scatter seismicity recorded between Tamayo FZ and the Marias Islands restricts the characterization of the plate boundary between the RIV and NAM plates. Some authors have proposed that Tamayo FZ and Marias I. Escarpment are the RIV-NAM plate boundary. Recently other authors have called that RIV-NAM boundary is a geomorphology lineament that runs from a Rivera Rise transform at 23N to the northern end of Marias I. Escarpment. Even so this concept is not sustained with seismic activity. Further this thought would imply that the oceanic lithosphere of Mazatlan Basin would form part of NAM plate. Other thoughts are either that there is a diffuse RIV-NAM plate boundary to the north of the Maria Archipelago, or Middle America Subduction Zone is gradually extending northward of the Maria Is. While the plate boundary at SE corner of the RIV plate is neither well defined morphologically nor seismically constraint, offshore Colima Coast. Some authors have proposed that this zone is a diffuse plate boundary between RIV and COC plates, result of a NE-SW shear plate motion. Other authors have proposed that the RIV-COC boundary extends E-W from the El Gordo Graben (EGG) at

  12. Exploration of the Canyon-Incised Continental Margin of the Northeastern United States Reveals Dynamic Habitats and Diverse Communities.

    Directory of Open Access Journals (Sweden)

    Andrea M Quattrini

    Full Text Available The continental margin off the northeastern United States (NEUS contains numerous, topographically complex features that increase habitat heterogeneity across the region. However, the majority of these rugged features have never been surveyed, particularly using direct observations. During summer 2013, 31 Remotely-Operated Vehicle (ROV dives were conducted from 494 to 3271 m depth across a variety of seafloor features to document communities and to infer geological processes that produced such features. The ROV surveyed six broad-scale habitat features, consisting of shelf-breaching canyons, slope-sourced canyons, inter-canyon areas, open-slope/landslide-scar areas, hydrocarbon seeps, and Mytilus Seamount. Four previously unknown chemosynthetic communities dominated by Bathymodiolus mussels were documented. Seafloor methane hydrate was observed at two seep sites. Multivariate analyses indicated that depth and broad-scale habitat significantly influenced megafaunal coral (58 taxa, demersal fish (69 taxa, and decapod crustacean (34 taxa assemblages. Species richness of fishes and crustaceans significantly declined with depth, while there was no relationship between coral richness and depth. Turnover in assemblage structure occurred on the middle to lower slope at the approximate boundaries of water masses found previously in the region. Coral species richness was also an important variable explaining variation in fish and crustacean assemblages. Coral diversity may serve as an indicator of habitat suitability and variation in available niche diversity for these taxonomic groups. Our surveys added 24 putative coral species and three fishes to the known regional fauna, including the black coral Telopathes magna, the octocoral Metallogorgia melanotrichos and the fishes Gaidropsarus argentatus, Guttigadus latifrons, and Lepidion guentheri. Marine litter was observed on 81% of the dives, with at least 12 coral colonies entangled in debris. While

  13. Developing an Experimental Watershed for Monitoring the Impacts of Bioenergy Production on Marginal Lands of the Northeastern U.S

    Science.gov (United States)

    Rau, B. M.; Adler, P. R.; Kemanian, A. R.; Saha, D.; Montes, F.

    2012-12-01

    In the northeastern U.S. over 400,000 acres have been placed into conservation programs to reduce erosion and improve water quality. Most of this acreage is within the Chesepeake Bay watershed. Many of these acres may be suitable for raising second generation bioenergy crops such as switchgrass (Panicum virgatum L.) or miscanthus (Miscanthus × giganteus). Bioenergy production may provide a viable economic incentive to keep marginal lands in perennial crop production, and improve water quality. However, the environmental impacts and benefits of second generation bioenergy crop production are not well understood on marginal lands. We designed an experimental watershed to compare switchgrass and miscanthus production against typical conservation grasslands. The Mattern Watershed is a horseshoe shaped 1st order watershed located near Leck Kill, PA, and is representative of the Appalachian Ridge and Valley Province. The upper portions of the watershed have been and are currently used for tillage corn and bean production. The lower portions of the watershed are excessively wet and have been in a conservation easement since 2005. In spring 2012 we planted eight 0.4 ha replicate plots of switchgrass (4 fertilized and 4 with no fertilizer) and four 0.4 ha plots of miscanthus into the lower portions of the watershed an additional four 0.4 ha plots were left in conservation grassland using a randomized block design. We compare biomass production, biomass elemental content, N2O emissions, soil moisture, shallow groundwater quality, surface runoff, and soil organic carbon in order to determine which treatment most effectively produces bioenergy feedstock, mitigates greenhouse gas emissions, and improves water quality. The experimental watershed will provide an unparalleled opportunity to verify and parameterize watershed, and bigeochemical models. Preliminary results suggest that early in the growing season cool season grasses minimized shallow groundwater NO3 and N2O

  14. Pathology and epidemiology of phocid herpesvirus-1 in wild and rehabilitating harbor seals (Phoca vitulina richardsi) in the northeastern Pacific.

    Science.gov (United States)

    Himworth, C G; Haulena, M; Lambourn, D M; Gaydos, J K; Huggins, J; Calambokidis, J; Ford, J K B; Zaremba, K; Raverty, S

    2010-07-01

    Phocid herpesvirus-1 (PhHV-1, subfamily Alphaherpesvirinae) was isolated from harbor seals (Phoca vitulina vitulina) in the Netherlands in 1985, and was subsequently identified in Pacific harbor seals (Phoca vitulina richardsi) from California, USA in the 1990s. PhHV-1-associated pathology was first recognized in harbor seal carcasses submitted to a veterinary diagnostic laboratory in Abbotsford, British Columbia, Canada in 2000, and 63 cases were identified by 2008. A review of these cases indicated that PhHV-1-associated disease is widespread in harbor seals in the wild and within rehabilitation facilities in the coastal northeastern Pacific (including British Columbia, Canada, and Washington, USA). Morbidity and mortality occurred primarily in neonatal and weanling seal pups, and was due to PhHV-1 alone, or in combination with other disease processes. All cases occurred between July and October, corresponding to the pupping and weaning seasons in this area. Although previous publications have described the prevalence of antibody to PhHV-1 in harbor seals from British Columbia, Canada and Washington, USA this is the first study to focus on the epidemiology and pathology of the virus in this region.

  15. Paleozoic paleogeographic and depositional developments on the central proto-Pacific margin of Gondwana: Their importance to hydrocarbon accumulation

    Science.gov (United States)

    Gohrbandt, K. H. A.

    1992-11-01

    During the Paleozoic Era, the western portion of the Gondwana continent between the equator and latitude 27°S of present-day South America bordered the proto-Pacific Ocean as a predominantly convergent margin. Following the Middle Cambrian accretion of the Arequipa-Belen-Antofalla Terrane, an epicontinental sea with communication to the proto-Pacific Ocean established itself along the length of the western margin of Gondwana during Late Cambrian and Early Ordovician time. The emergence of a proto-Cordillera led to significant separation of the epicontinental sea from the proto-Pacific Ocean during Silurian and Devonian times. Gradual erosion of that proto-Cordillera during Carboniferous and Early Permian time once again facilitated widespread transgression of the proto-Pacific Ocean into the epicontinental domain. At the end of the Early Permian, the sea retreated from Gondwana and a proto-Cordillera was re-established. The proto-Cordillera and the craton of Gondwana controlled sediment type and distribution in the epicontinental sea. Deposition occurred in five tectono-sedimentary cycles, which were separated by orogenic pulses that resulted in regional erosion of the previously deposited section. Oil and gas have been produced from the Paleozoic epicontinental sediments of Argentina, Bolivia, Peru, and Brazil, in an area in which exploration efforts are ongoing. Sandstone reservoirs and argillaceous source rocks of commercial importance formed during the episodes of sedimentation, but carbonates do not contribute to commercial hydrocarbon generation and accumulation. Cap rocks are provided by shales or evaporites.

  16. Mitochondrial Genetic Structure and Matrilineal Origin of White Sharks, Carcharodon carcharias, in the Northeastern Pacific: Implications for Their Conservation.

    Science.gov (United States)

    Oñate-González, Erick C; Rocha-Olivares, Axayácatl; Saavedra-Sotelo, Nancy C; Sosa-Nishizaki, Oscar

    2015-01-01

    White sharks (Carcharodon carcharias, WS henceforth) are globally and regionally threatened. Understanding their patterns of abundance and connectivity, as they relate to habitat use, is central for delineating conservation units and identifying priority areas for conservation. We analyzed mitochondrial data to test the congruence between patterns of genetic connectivity and of individual movements in the Northeastern Pacific (NEP) and to trace the matrilineal origin of immature WS from coastal California and Baja California to adult aggregation areas. We analyzed 186 mitochondrial control region sequences from sharks sampled in Central California (CC; n = 61), Southern California Bight (SCB; n = 25), Baja California Pacific coast (BCPC; n = 9), Bahía Vizcaíno (BV; n = 39), Guadalupe Island (GI; n = 45), and the Gulf of California (GC; n = 7). Significant mitochondrial differentiation between adult aggregation areas (CC, GI) revealed two reproductive populations in the NEP. We found general concordance between movement patterns of young and adult WS with genetic results. Young sharks from coastal California and Baja California were more likely born from females from GI. Mitochondrial differentiation of young-of-the-year from SCB and BV suggests philopatry to nursery areas in females from GI. These results provide a genetic basis of female reproductive behavior at a regional scale and point to a preponderance of sharks from GI in the use of the sampled coastal region as pupping habitat. These findings should be considered in Mexican and US management and conservation strategies of the WS NEP population. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. From Marginalized to Validated: An In-Depth Case Study of an Asian American, Native American and Pacific Islander Serving Institution

    Science.gov (United States)

    Nguyen, Thai-Huy; Nguyen, Mike Hoa; Nguyen, Bach Mai Dolly; Gasman, Marybeth; Conrad, Clifton

    2018-01-01

    This article highlights the capacity of an Asian American, Native American and Pacific Islander Institution (AANAPISI) to serve as an institutional convertor--by addressing challenges commonly associated with marginalized students--for low-income, Asian American and Pacific Islander students entering college. Through an in-depth case study, we…

  18. Rearing conditions and habitat use of white seabass (Atractoscion nobilis) in the northeastern Pacific based on otolith isotopic composition

    Science.gov (United States)

    Romo-Curiel, Alfonsina E.; Herzka, Sharon Z.; Sepulveda, Chugey A.; Pérez-Brunius, Paula; Aalbers, Scott A.

    2016-03-01

    White seabass, Atractoscion nobilis, is an important coastal resource throughout both California and Baja California, but whether this species comprises a single or multiple subpopulations in the northeastern Pacific is not known. The aim of this study was to infer larval rearing habitats and population structure of white seabass by sampling adults from three regions spanning a latitudinal temperature gradient and a distance of over 1000 km, and analyzing the isotopic composition (δ18O and δ13C) of otolith aragonite corresponding to the larval, juvenile and adult stages. Otolith cores revealed high isotopic variability and no significant differences among regions, suggesting overlapping rearing conditions during the larval stage, the potential for long distance dispersal or migration or selective mortality of larvae at higher temperatures. Back-calculated temperatures of aragonite precipitation derived using regional salinity-δw relationships and local salinity estimates also did not differ significantly. However, there were significant differences between the δ18O values of the first seasonal growth ring of age 0 fish as well as back-calculated aragonite precipitation temperatures, suggesting the presence of two potentially discrete subpopulations divided by Punta Eugenia (27°N) along the central Baja California peninsula. These findings are consistent with regional oceanographic patterns and are critical for understanding white seabass population structure, and provide information needed for the implementation of appropriate management strategies.

  19. Anomalous South Pacific lithosphere dynamics derived from new total sediment thickness estimates off the West Antarctic margin

    Science.gov (United States)

    Wobbe, Florian; Lindeque, Ansa; Gohl, Karsten

    2014-12-01

    Paleotopographic models of the West Antarctic margin, which are essential for robust simulations of paleoclimate scenarios, lack information on sediment thickness and geodynamic conditions, resulting in large uncertainties. A new total sediment thickness grid spanning the Ross Sea-Amundsen Sea-Bellingshausen Sea basins is presented and is based on all the available seismic reflection, borehole, and gravity modeling data offshore West Antarctica. This grid was combined with NGDC's global 5 arc minute grid of ocean sediment thickness (Whittaker et al., 2013) and extends the NGDC grid further to the south. Sediment thickness along the West Antarctic margin tends to be 3-4 km larger than previously assumed. The sediment volume in the Bellingshausen, Amundsen, and Ross Sea basins amounts to 3.61, 3.58, and 2.78 million km3, respectively. The residual basement topography of the South Pacific has been revised and the new data show an asymmetric trend over the Pacific-Antarctic Ridge. Values are anomalously high south of the spreading ridge and in the Ross Sea area, where the topography seems to be affected by persistent mantle processes. In contrast, the basement topography offshore Marie Byrd Land cannot be attributed to dynamic topography, but rather to crustal thickening due to intraplate volcanism. Present-day dynamic topography models disagree with the presented revised basement topography of the South Pacific, rendering paleotopographic reconstructions with such a limited dataset still fairly uncertain.

  20. Map showing bottom topography of the Pacific Continental Margin, Strait of Juan de Fuca to Cape Mendocino

    Science.gov (United States)

    Grim, M.S.; Chase, T.E.; Evenden, G.I.; Holmes, M.L.; Normark, W.R.; Wilde, Pat; Fox, C.J.; Lief, C.J.; Seekins, B.A.

    1992-01-01

    All contours, geographic outlines, and political boundaries shown on this map of the bottom topography, or bathymetry, of the Pacific continental margin between 34° and 41° N. latitudes were plotted from digital data bases in the library of the U.S. Geological Survey (USGS)-National Oceanic and Atmospheric Administration (NOAA) Joint Office for Mapping and Research (JOMAR). These digital data were obtained and compiled from many sources; consequently, data quality varies within particular data bases as well as from one data base to another.

  1. Using Stable Isotope Analysis to Understand the Migration and Trophic Ecology of Northeastern Pacific White Sharks (Carcharodon carcharias)

    Science.gov (United States)

    Carlisle, Aaron B.; Kim, Sora L.; Semmens, Brice X.; Madigan, Daniel J.; Jorgensen, Salvador J.; Perle, Christopher R.; Anderson, Scot D.; Chapple, Taylor K.; Kanive, Paul E.; Block, Barbara A.

    2012-01-01

    The white shark (Carcharodon carcharias) is a wide-ranging apex predator in the northeastern Pacific (NEP). Electronic tagging has demonstrated that white sharks exhibit a regular migratory pattern, occurring at coastal sites during the late summer, autumn and early winter and moving offshore to oceanic habitats during the remainder of the year, although the purpose of these migrations remains unclear. The purpose of this study was to use stable isotope analysis (SIA) to provide insight into the trophic ecology and migratory behaviors of white sharks in the NEP. Between 2006 and 2009, 53 white sharks were biopsied in central California to obtain dermal and muscle tissues, which were analyzed for stable isotope values of carbon (δ13C) and nitrogen (δ15N). We developed a mixing model that directly incorporates movement data and tissue incorporation (turnover) rates to better estimate the relative importance of different focal areas to white shark diet and elucidate their migratory behavior. Mixing model results for muscle showed a relatively equal dietary contribution from coastal and offshore regions, indicating that white sharks forage in both areas. However, model results indicated that sharks foraged at a higher relative rate in coastal habitats. There was a negative relationship between shark length and muscle δ13C and δ15N values, which may indicate ontogenetic changes in habitat use related to onset of maturity. The isotopic composition of dermal tissue was consistent with a more rapid incorporation rate than muscle and may represent more recent foraging. Low offshore consumption rates suggest that it is unlikely that foraging is the primary purpose of the offshore migrations. These results demonstrate how SIA can provide insight into the trophic ecology and migratory behavior of marine predators, especially when coupled with electronic tagging data. PMID:22355313

  2. Modeling of extreme freshwater outflow from the north-eastern Japanese river basins to western Pacific Ocean

    Science.gov (United States)

    Troselj, Josko; Sayama, Takahiro; Varlamov, Sergey M.; Sasaki, Toshiharu; Racault, Marie-Fanny; Takara, Kaoru; Miyazawa, Yasumasa; Kuroki, Ryusuke; Yamagata, Toshio; Yamashiki, Yosuke

    2017-12-01

    This study demonstrates the importance of accurate extreme discharge input in hydrological and oceanographic combined modeling by introducing two extreme typhoon events. We investigated the effects of extreme freshwater outflow events from river mouths on sea surface salinity distribution (SSS) in the coastal zone of the north-eastern Japan. Previous studies have used observed discharge at the river mouth, as well as seasonally averaged inter-annual, annual, monthly or daily simulated data. Here, we reproduced the hourly peak discharge during two typhoon events for a targeted set of nine rivers and compared their impact on SSS in the coastal zone based on observed, climatological and simulated freshwater outflows in conjunction with verification of the results using satellite remote-sensing data. We created a set of hourly simulated freshwater outflow data from nine first-class Japanese river basins flowing to the western Pacific Ocean for the two targeted typhoon events (Chataan and Roke) and used it with the integrated hydrological (CDRMV3.1.1) and oceanographic (JCOPE-T) model, to compare the case using climatological mean monthly discharges as freshwater input from rivers with the case using our hydrological model simulated discharges. By using the CDRMV model optimized with the SCE-UA method, we successfully reproduced hindcasts for peak discharges of extreme typhoon events at the river mouths and could consider multiple river basin locations. Modeled SSS results were verified by comparison with Chlorophyll-a distribution, observed by satellite remote sensing. The projection of SSS in the coastal zone became more realistic than without including extreme freshwater outflow. These results suggest that our hydrological models with optimized model parameters calibrated to the Typhoon Roke and Chataan cases can be successfully used to predict runoff values from other extreme precipitation events with similar physical characteristics. Proper simulation of extreme

  3. Introduction to the Special Section "Proxy Records and Mechanistic Studies of the Late Quaternary Paleoceanography of the Western Pacific Marginal Seas Using IMAGES Cores"

    Directory of Open Access Journals (Sweden)

    Meixun Zhao

    2008-01-01

    Full Text Available The western Pacific Ocean plays an important role in regulating and modulating the global climate system on interannual to geological timescales. Excellent records have been acquired by coring high sedimentation rate sites in the marginal seas of the western Pacific Ocean during IMAGES cruises. This special section has been proposed to publish papers presenting high-resolution records and the interpretation of climate changemechanisms revealed by these records.

  4. Origin of marginal basins of the NW Pacific and their plate tectonic reconstructions

    Science.gov (United States)

    Xu, Junyuan; Ben-Avraham, Zvi; Kelty, Tom; Yu, Ho-Shing

    2014-03-01

    Geometry of basins can indicate their tectonic origin whether they are small or large. The basins of Bohai Gulf, South China Sea, East China Sea, Japan Sea, Andaman Sea, Okhotsk Sea and Bering Sea have typical geometry of dextral pull-apart. The Java, Makassar, Celebes and Sulu Seas basins together with grabens in Borneo also comprise a local dextral, transform-margin type basin system similar to the central and southern parts of the Shanxi Basin in geometry. The overall configuration of the Philippine Sea resembles a typical sinistral transpressional "pop-up" structure. These marginal basins except the Philippine Sea basin generally have similar (or compatible) rift history in the Cenozoic, but there do be some differences in the rifting history between major basins or their sub-basins due to local differences in tectonic settings. Rifting kinematics of each of these marginal basins can be explained by dextral pull-apart or transtension. These marginal basins except the Philippine Sea basin constitute a gigantic linked, dextral pull-apart basin system.

  5. Sedimentology of seismo-turbidites off the Cascadia and northern California active tectonic continental margins, Pacific Ocean

    Science.gov (United States)

    Gutierrez Pastor, Julia; Nelson, Hans; Goldfinger, Chris; Escutia, Carlota

    2013-04-01

    confluences cause multi-pulsed and stacked turbidites that are typical for seismo-turbidites generated by a single great earthquake. Along both margins, earthquake triggering and multi-pulsed or stacked turbidites become an alternative explanation for amalgamated turbidite beds in active tectonic margins and show that multiple grain-size pulses and reverse grading are not unique criteria for hyperpycnites, thalweg levee turbidites, or mini-basin margin turbidites. Analyses of the turbidites along the Cascadia and northern California margins reveal common sedimentologic characteristics of turbidites triggered by great earthquakes that can be used to distinguish seismo-turbidites in other active tectonic margins around the world. Gutierrez-Pastor, J., Nelson C. H., Goldfinger, C., and Escutia, C., Sedimentology of seismo-turbidites off the Cascadia and northern California active tectonic continental margins, northwest Pacific Ocean, Marine Geology 336 (2013) 99-119. http://dx.doi.org/10.1016/j.margeo.2012.11.010

  6. Latitudinal variations in intermediate depth ventilation and biological production over northeastern Pacific Oxygen Minimum Zones during the last 60 ka

    Science.gov (United States)

    Cartapanis, Olivier; Tachikawa, Kazuyo; Bard, Edouard

    2012-10-01

    Mechanisms affecting past variability in the Oxygen Minimum Zone (OMZ) in the Eastern Tropical North Pacific (ETNP) are poorly known. We analyzed core MD02-2524, obtained from the Nicaragua Margin in the present ETNP OMZ for major and minor elements (titanium (Ti), brome (Br), silicon (Si), potassium (K), and calcium (Ca)) using an X-ray Fluorescence (XRF) core scanner, and redox-sensitive trace elements (uranium (U), molybdenum (Mo), and nickel (Ni)) determined by ICP-MS. The U and Mo content was higher during the deglaciation than during the Holocene and the last glacial maximum, whereas enrichment was not observed for Ni, an element closely associated with organic matter. High-resolution XRF scanning indicated that the Ca-based carbonate content had millennial-scale variability inversely correlated with Br-based organic matter and Si/K-based opal content during the last glacial period. The available data suggest no clear regional trend in biological productivity during the last deglaciation, but significant local variability in the coastal eastern equatorial Pacific. The trace element enrichment and the lack of a concomitant increase in biogenic phases indicated that an enhanced ETNP OMZ, at least between 15°N and 12°N at a water depth of 500-900 m, was principally caused by a reduced oxygen supply driven by oceanic circulation to the Nicaragua Basin during the deglaciation. The observed patterns can be interpreted as the distinct changes in the oxygenation state of northern and southern water masses at intermediate depths. We also found evidence for a decoupling between local productivity and pore water oxygenation for several millennial-scale events during Marine Isotopic Stage 3, indicating that remote oxygen consumption and/or oceanic ventilation impacted OMZ intensity. Multi-millennial scale variations of the productivity at Papagayo upwelling cell displayed an opposite trend from productivity at the Costa Rica Dome, in relation with the latitudinal shift

  7. Abundance, biomass and caloric content of Chukchi Sea bivalves and association with Pacific walrus (Odobenus rosmarus divergens) relative density and distribution in the northeastern Chukchi Sea

    Science.gov (United States)

    Young, Jordann K.; Black, Bryan A.; Clarke, Janet T.; Schonberg, Susan V.; Dunton, Kenneth H.

    2017-10-01

    The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a substantial benthic infaunal community of which bivalves are a major component. We assessed the patterns in population abundance, biomass, and caloric content of ten dominant bivalve taxa in relation to the distribution of the upper trophic level consumer Pacific walrus (Odobenus rosmarus divergens). Bivalves were collected over four cruises in the northeastern Chukchi Sea (2009, 2010, 2012, 2013). Our samples were largely dominated by calorie-dense, deposit-feeding species, including Macoma spp., Ennucula tenuis, Nuculana spp. and Yoldia spp. Weight-frequency distributions were strongly right-skewed for most taxa, though some showed evidence of a bimodal distribution. Caloric densities as measured through bomb calorimetry significantly differed among taxa (ANOVA F = 32.57, df = 9, p-valueanimal wet weight was found to be a reliable predictor of whole animal caloric content. Bivalve populations and peak caloric densities were centered on and to the southeast of Hanna Shoal, which coincided with peak Pacific walrus relative density (walruses per km surveyed) from July through October. Significant differences in mean caloric values were found between areas with and without walruses present (student's t-test, t=-2.9088, df = 252.24, p-value = 0.003952), as well as between areas with low and high walrus relative densities in the pooled annual dataset and in each individual month except October (ANOVA, p-value<0.05). The high-calorie deposit feeders that dominate these bivalve communities preferentially consume food sources, such as sea ice algae, that are likely to be affected by shifting sea ice dynamics. As such, continued warming has the potential to alter bivalve communities in the northeastern Chukchi Sea, which may have profound implications for upper trophic levels.

  8. Caryocar coriaceum (Caryocaraceae) diaspore removal and dispersal distance on the margin and in the interior of a Cerrado area in Northeastern Brazil.

    Science.gov (United States)

    Santos, Gilney Charll; Schiel, Nicola; Araújo, Elcida de Lima; Albuquerque, Ulysses Paulino

    2016-09-01

    The seed dispersal process is a crucial stage in plant regeneration and maintenance of forest biological diversity. While the number of removed seeds is quantitative, the distance to which a seed is removed from its origin is qualitative, because it affects the probability that a seed will germinate and recruit to the next life stage. However, the creation of forest margins can negatively affect the seed dispersal process, especially for large-diaspore plant species. In this study, the diaspore removal and dispersal distance of Caryocar coriaceum, a tree with large diaspores that is in danger of extinction, were analyzed. The study was conducted for two consecutive years in a protected forest in Northeastern Brazil. Each year, 1 200 diaspores with a nylon wire and a satin tape yellow were used and equally distributed in 120 experimental stations established on the forest margin and in the interior. During the first year of the study, no differences in diaspore removal and dispersal distance were found among the investigated environments. However, for the second year of the study, the number of removed diaspores differed significantly; nevertheless, the dispersal distance was not different between the forest margin and the interior. The low diaspore removal percentages suggest that species recruitment may be compromised because the diaspore accumulation close to the relatives enables higher fungi and insect attack. In addition, most of the few removed diaspores were found at short distances from their sources (up to 5 m), which can lead to low genetic variability. Virtually no diaspore was found buried by hoarding rodents, and no diaspore was found preyed upon by these animals. Evidence found in this study suggests the local loss of species dispersers, which can compromise the maintenance of forest biological diversity.

  9. Biogeochemistry and ecosystems of continental margins in the western North Pacific Ocean and their interactions and responses to external forcing - an overview and synthesis

    Science.gov (United States)

    Liu, K.-K.; Kang, C.-K.; Kobari, T.; Liu, H.; Rabouille, C.; Fennel, K.

    2014-12-01

    In this special issue we examine the biogeochemical conditions and marine ecosystems in the major marginal seas of the western North Pacific Ocean, namely, the East China Sea, the Japan/East Sea to its north and the South China Sea to its south. They are all subject to strong climate forcing as well as anthropogenic impacts. On the one hand, continental margins in this region are bordered by the world's most densely populated coastal communities and receive tremendous amount of land-derived materials. On the other hand, the Kuroshio, the strong western boundary current of the North Pacific Ocean, which is modulated by climate oscillation, exerts strong influences over all three marginal seas. Because these continental margins sustain arguably some of the most productive marine ecosystems in the world, changes in these stressed ecosystems may threaten the livelihood of a large population of humans. This special issue reports the latest observations of the biogeochemical conditions and ecosystem functions in the three marginal seas. The studies exemplify the many faceted ecosystem functions and biogeochemical expressions, but they reveal only a few long-term trends mainly due to lack of sufficiently long records of well-designed observations. It is critical to develop and sustain time series observations in order to detect biogeochemical changes and ecosystem responses in continental margins and to attribute the causes for better management of the environment and resources in these marginal seas.

  10. Reconstruction of cyclical and abrupt changes in northeastern Pacific precipitation during the Late Holocene based on marine sediments preserved in Effingham Inlet, British Columbia

    Science.gov (United States)

    Dallimore, A.; Thomson, R.; Enkin, R. J.

    2009-12-01

    Accurate interpretation of paleoenvironmental time series requires the reliable chronological control now provided by an age-model of a 40 m long marine sediment core raised from Effingham Inlet in Barkley Sound, British Columbia in 2002 (Core MD02-2494). The Late-Pleistocene to Holocene age model provides detailed annual to decadal resolution of the timing of proxy paleoenvironmental indicators preserved in the core based on 46 radiocarbon dates and the presence of the Mazama Ash. Also determined is the timing of instantaneous depositional events related to seismic activity along the Cascadia subduction zone. A frequency-time analysis of the grey scale of sediment x-rays from the calibrated core, which represent the volume and timing of precipitation events in area over the past 6,000 years, show cyclical as well as abrupt “regime change” controls on the northeast Pacific and climate system. This time series, combined with a time series derived from the core using a geochemical reconstruction of Pacific decadal variability, now provide a quantitative means of comparing the marine paleoenvironmental record of ocean and climate conditions of the B.C. coast to other time series of Holocene northeastern Pacific paleoenvironmental indicators.

  11. Living on the margin: dealing with climate change in remote Pacific islands

    DEFF Research Database (Denmark)

    Birk, Thomas Ladegaard Kümmel

    with the marginal socioeconomic and geographical position of the island groups within Solomon Islands along with internal factors, not the least population growth and pressure on natural resources. This gives rise to both push and pull factors contributing to the widespread migration of islanders, in particular...... young men, to other locations in the Solomon Islands, especially the capital city Honiara, in search of better income, education and city lifestyles. The thesis studies how (more or less) forced relocations of island communities in the past have cast long shadows, due to unresolved issues of land tenure......, while current voluntary migration may be claimed to have positive effects on island communities. In order for migration to constitute a viable ‘adaptation option’ in a future situation of increased rate of sea-level rise, certain barriers to migration need to be overcome, however. Theses barriers...

  12. Seismic stratigraphy and structure of the Northland Plateau and the development of the Vening Meinesz transform margin, SW Pacific Ocean

    Science.gov (United States)

    Herzer, R. H.; Davy, B. W.; Mortimer, N.; Quilty, P. G.; Chaproniere, G. C. H.; Jones, C. M.; Crawford, A. J.; Hollis, C. J.

    2009-03-01

    The Northland Plateau and the Vening Meinesz “Fracture” Zone (VMFZ), separating southwest Pacific backarc basins from New Zealand Mesozoic crust, are investigated with new data. The 12-16 km thick Plateau comprises a volcanic outer plateau and an inner plateau sedimentary basin. The outer plateau has a positive magnetic anomaly like that of the Three Kings Ridge. A rift margin was found between the Three Kings Ridge and the South Fiji Basin. Beneath the inner plateau basin, is a thin body interpreted as allochthon and parautochthon, which probably includes basalt. The basin appears to have been created by Early Miocene mainly transtensive faulting, which closely followed obduction of the allochthon and was coeval with arc volcanism. VMFZ faulting was eventually concentrated along the edge of the continental shelf and upper slope. Consequently arc volcanoes in a chain dividing the inner and outer plateau are undeformed whereas volcanoes, in various stages of burial, within the basin and along the base of the upper slope are generally faulted. Deformed and flat-lying Lower Miocene volcanogenic sedimentary rocks are intimately associated with the volcanoes and the top of the allochthon; Middle Miocene to Recent units are, respectively, mildly deformed to flat-lying, calcareous and turbiditic. Many parts of the inner plateau basin were at or above sea level in the Early Miocene, apparently as isolated highs that later subsided differentially to 500-2,000 m below sea level. A mild, Middle Miocene compressive phase might correlate with events of the Reinga and Wanganella ridges to the west. Our results agree with both arc collision and arc unzipping regional kinematic models. We present a continental margin model that begins at the end of the obduction phase. Eastward rifting of the Norfolk Basin, orthogonal to the strike of the Norfolk and Three Kings ridges, caused the Northland Plateau to tear obliquely from the Reinga Ridge portion of the margin, initiating the

  13. Mid-miocene cooling in the northern Qilian Shan, northeastern margin of the Tibetan plateau, revealed by apatite fission-track and VR analysis

    International Nuclear Information System (INIS)

    George, A.D.; Wyrwoll, K.-H.; Jie, C.; Yanchou, L.

    1999-01-01

    Full text: Growth of the Tibetan Plateau along its northeastern margin by crustal shortening and thickening is linked to the Altyn Tagh Fault, a ∼1500 km long sinistral strike-slip fault which has played a significant role in accommodating the convergence of India and Eurasia. The NW-trending Qilian Shan (mountains) that mark the northeastern edge of the plateau rise nearly 5000 m above the adjacent Juice Basin of the Hexi Corridor. The Qilian Shan is a mid-Paleozoic orogenic suture belt composed of numerous thrust slices of deformed Lower Paleozoic (Cambrian-Silurian) metasedimentary and metavolcanic strata. The older Precambrian basement is also exposed in some thrust sheets, as are remnants of Upper Paleozoic-Jurassic strata. Cretaceous fluvial sandstones and conglomerates are locally preserved. The neighbouring Juice Basin contains a thick succession of Neogene-Quaternary fluvial strata (∼3.5 km thick) which unconformably overlies Lower Cretaceous rocks. Adjacent to the Qilian Shan, the oldest Neogene strata in the Juice Basin are Miocene in age overlain by more extensive Pliocene and Quaternary sediments, whereas basal Oligocene strata are exposed on the northern side of the basin. Neogene and Quaternary strata are being actively deformed by thrust-related folding along the margins and within the Jiuxi Basin. Apatite fission-track and vitrinite reflectance data were obtained from Precambrian to Tertiary outcrop samples from the northern Qilian Shan and Juice Basin to provide constraints on timing of exhumation and cooling. All the samples record multiple cooling episodes. Tertiary cooling from peak paleotemperatures (40-120 deg C) beginning sometime between 20 and 10 Ma (mid-Miocene) is common to all samples. This age is significantly older than previous models which proposed initiation of uplift in the Pliocene-Pleistocene, i.e., no older than 5-6 Ma. For any reasonable paleo-geothermal gradient, the degree of mid-Miocene cooling requires km

  14. Geology and exploration in southwest Pacific Australian region: Western and Northwestern Margin basins of Australia

    Energy Technology Data Exchange (ETDEWEB)

    Woollands, M.A. (BHP Petroleum Pty Ltd., Melbourne (Australia))

    1991-03-01

    The Marginal basins of Western and Northwestern Australia extend approximately 3,800 km along the coast and comprise both continental shelf and adjacent deepwater plateau areas. From north to south, the principal basins are the Sahul/Malita, Browse, Carnarvon, and Perth basins. The stratigraphic sequence within each basin is broadly similar, with initial widespread Triassic-Early Jurassic deposition in broad regional pre-rift sags. Middle Jurassic to Late Jurassic rifting on the Northwest Shelf and early Cretaceous rifting in the Perth basin varies in intensity across the region, and provides the primary control of hydrocarbon distribution through trap type, reservoir, and source rock quality. The best-developed oil source rocks of the region are found in these Jurassic rifted sequences. Although drilling to date has been generally sparse, with only some 824 wells throughout the entire area, significant accumulations of gas and oil have been found in the offshore Carnarvon basin and the Vulcan Graben area of the Browse basin. Recent discoveries of commercial oil at Jabiru in the Vulcan graben and Griffin in the Carnarvon basin have again focused activity on the area's oil potential. Many structural traps remain to be drilled and the potential for stratigraphic trapping has been only slightly explored. Large, poorly explored frontier areas, between the established producing areas and in the Perth basin, as well as adjacent deepwater, are available. However, present data suggest that not all key success factors, notably mature oil source rocks and good reservoirs, may be present in these areas.

  15. The Pan-African continental margin in northeastern Africa: Evidence from a geochronological study of granulites at Sabaloka, Sudan

    International Nuclear Information System (INIS)

    Kroener, A.

    1987-01-01

    Ion microprobe zircon ages, a Nd model age and Rb-Sr whole-rock dates are reported from the high-grade gneiss terrain at Sabaloka on the River Nile north of Khartoum, formally considered to be part of the Archaean/early Proterozoic Nile craton. The granulites, which are of both sedimentary and igneous derivation, occur as remnants in migmatites. Detrital zircon ages range from ≅ 1000 to ≅ 2650 Ma and prove the existence of Archaean to late Proterozoic continental crust in the sedimentary source region. The Nd model age for one sedimentary granulite is between 1.26 (T CHUR ) and 1.70 (T DM ) Ga and provides a mean crustal residence age for the sedimentary precursor. Igneous zircons in enderbitic gneiss crystallized at 719±81 Ma ago, an age that also corresponds to severe Pb loss in the detrital zircons and whic probably reflects the granulite event at Sabaloka. The Rb-Sr data indicate isotropic homogenization at about 700 Ma ago in the granulites and severe post-granulite disturbance at ≅ 570 Ma in the migmatites. We associate this disturbance with hydration, retrograde metamorphism and anatexis that produced undeformed granites ≅ 540 Ma ago. The ≅ 700 Ma granulite event at Sabaloka suggests that this part of the Sudan belongs to the Pan-African Mozambique belt while the ancient Nile craton lay farther west. The gneisses studied here may represent the infrastructure of the ancient African continental margin onto which the juvenile arc assemblage of the Arabian-Nubian shield was accreted during intense horizontal shortening and crustal interstacking of a major collision event. (orig.)

  16. Silurian high-pressure granulites from Central Qiangtang, Tibet: Constraints on early Paleozoic collision along the northeastern margin of Gondwana

    Science.gov (United States)

    Zhang, Xiu-Zheng; Dong, Yong-Sheng; Li, Cai; Deng, Ming-Rong; Zhang, Le; Xu, Wang

    2014-11-01

    High-pressure (HP) granulites are commonly regarded as indicators of plate convergence and collision following the subduction of oceanic or continental crust. In this study we report the discovery of Silurian HP basic granulites from Central Qiangtang on the Tibetan Plateau. Detailed petrology and geochronology reveal a three-stage metamorphic history based on inclusions, reaction textures, and garnet zoning patterns. Peak metamorphism at 830-860 °C and 1.15-1.45 GPa (M1) is defined by high-Ca garnet cores, high-Al clinopyroxene, and high-Na plagioclase. Symplectites or coronas of orthopyroxene + plagioclase ± magnetite around garnet porphyroblasts indicate garnet breakdown reactions at ca. 810-830 °C and 0.65-0.85 GPa (M2). Kelyphites of amphibole + plagioclase around garnet formed during the cooling process at about 590-650 °C and 0.62-0.82 GPa (M3). These results help define a sequential P-T path containing near-isothermal decompression (ITD) and near-isobaric cooling (IBC) stages. Identification of mineral inclusion assemblages in zircons dated by U-Pb SHRIMP and LA-ICP-MS reveals peak HP metamorphism at ca. 427-422 Ma, subsequent near-isothermal decompression with associated retrograde reactions at ca. 392-389 Ma, and continued cooling at ca. 360 Ma. The P-T-t path of HP basic granulites reflects collision followed by extensional exhumation during early Paleozoic orogenesis. The present results indicate the occurrence of a collisional event along the northern margin of Indo-Australian Gondwana during the Silurian. Renewed Gondwana-directed subduction and subsequent collision probably led to the opening of the Paleo-Tethys Ocean.

  17. Seven new and four known species of the genus Acantholaimus (Nematoda: Chromadoridae) from the abyssal manganese nodule field (Clarion-Clipperton Fracture Zone, North-Eastern Tropical Pacific)

    Science.gov (United States)

    Miljutina, Maria A.; Miljutin, Dmitry M.

    2012-09-01

    The descriptions of seven new and supplemental descriptions of four known species of the genus Acantholaimus (Nematoda: Chromadoridae) from about 5,000 m depth in the abyssal manganese nodule field of the French Claim of the Clarion-Clipperton Fracture Zone (north-eastern tropical Pacific) are given. A. arthrochaeta sp. n. differs from other Acantholaimus species in having jointed cephalic setae. A. barbatus sp. n. is characterized by long cephalic setae and the presence of numerous somatic setae at the level of the pharynx. A. cornutus sp. n. possesses strong onchia and rugae and short cephalic setae. A. robustus sp. n. is characterized by a very large body size, two very large onchia, strongly developed rugae, and cervical setae grouped in threes. A. sieglerae sp. n. is a comparatively small species, though with very large onchia. A. tchesunovi sp. n. can be differentiated from the other species by the lateral differentiation of the body cuticle, consisting of 6-7 longitudinal rows of pores. A. veitkoehlerae sp. n. has a narrow elongate anterior end, two cervical setae, and strong onchia. A. angustus and A. occultus were found about 5,200 km from their type localities in the Peru Basin, south-east Pacific. A. iubilus and A. maks were previously found in different parts of the Atlantic and in the Peru Basin.

  18. Spatial/temporal patterns of Quaternary faulting in the southern limb of the Yellowstone-Snake River Plain seismic parabola, northeastern Basin and Range margin

    Energy Technology Data Exchange (ETDEWEB)

    McCalpin, J.P. (GEO-HAZ Consultants, Estes Park, CO (United States))

    1993-04-01

    During the period 1986--1991, 11 backhoe trenches were excavated across six Quaternary faults on the northeastern margin of the Basin and Range province. These faults comprise the southern limb of a parabola of Quaternary faults and historic moderate-magnitude earthquakes which is roughly symmetrical about the Snake River Plain, and heads at the Yellowstone hot spot. Fifteen Holocene paleoseismic events have been bracketed by radiocarbon or thermoluminescence ages. On the six central faults, the latest rupture event occurred in a relatively short time interval between 3 ka and 6 ka. The period between 6 ka and the end of the latest glaciation (ca. 15 ka) was a period of relative tectonic quiescence on the central faults, but not on the two end faults with higher slip rates (Wasatch and Teton faults). Southward-younging of events in the 3--6 ka period may indicate that temporally-clustered faulting was initiated at the Yellowstone hot spot. Faults at the same latitude, such as the Star Valley-Grey's River pair of faults, or the East Cache-Bear Lake-Rock Creek system of faults, show nearly identical timing of latest rupture events within the pairs or systems. Faults at common latitudes probably sole into the same master decollement, and thus are linked mechanically like dominoes. The timing of latest ruptures indicates that faulting on the westernmost fault preceded faulting on successively more eastern faults by a few hundred years. This timing suggests that slip on the westernmost faults mechanically unloaded the system, causing tectonic instabilities farther east.

  19. Adjustments of a global Finite-Element Sea Ice Ocean Model configuration to improve the general ocean circulation in the North Pacific and its marginal seas.

    Science.gov (United States)

    Scholz, Patrick; Lohmann, Gerrit

    2017-04-01

    The sub-Arctic oceans like the Sea of Okhotsk, the Bering Sea, the Labrador Sea or the Greenland- Irminger-Norwegian (GIN) Sea react particularly sensitive to global climate changes and have the potential to reversely regulate climate change by CO2 uptake in the other areas of the world. So far, the natural processes in the Arctic and Subarctic system, especially over the Pacific realm, remain poorly understood in terms of numerical modeling. As such, in this study we focus on the North Pacific and its adjacent marginal seas (e.g. the Sea of Okhotsk, the Bering Sea and the Sea of Japan), which have nowadays a significant role in the climate system of the Northwest Pacific by influencing the atmospheric and oceanic circulation as well as the hydrology of the Pacific water masses. The Sea of Okhotsk, in particular, is characterized by a highly dynamical sea-ice coverage, where, in autumn and winter, due to massive sea ice formation and brine rejection, the Sea of Okhotsk Intermediate Water (SOIW) is formed which contributes to the mid-depth (500-1000m) water layer of the North Pacific known as newly formed North Pacific Intermediate Water (NPIW). By employing a Finite-Element Sea-Ice Ocean Model (FESOM), in a global configuration, but with high resolution over the marginal seas of the Northwest Pacific Ocean ( 7 km), we tested different meshes and forcing improvements to correct the general ocean circulation in the North Pacific realm towards a more realistic pattern. By using different forcing data (e.g. CORE2, ERA-40/interim, CCMP-correction), adapting the mesh resolutions in the tropical and subtropical North Pacific and changing the bathymetry over important inflow straits (e.g. Amukta Passage, Kruzenstern Strait), we show that the better results are obtained (when compared with observational data) via a combination of CCMP corrected COREv2 forcing with increased resolution in the pathway of the Kuroshio Extension Current and Northern Equatorial Current.

  20. Tectonic erosion and consequent collapse of the Pacific margin of Costa Rica: Combined implications from ODP leg 170, seismic offshore data, and regional geology of the Nicoya Peninsula

    Science.gov (United States)

    Vannucchi, P.; Scholl, D. W.; Meschede, M.; McDougall-Reid, K.

    2001-01-01

    The convergent margin off the Pacific coast of the Nicoya Peninsula of Costa Rica exhibits evidence for subduction erosion caused by the underthrusting Cocos plate. Critical evidence for efficacy of this process was recovered at the Ocean Drilling Program (ODP) drilling Site 1042 (Leg 170), positioned ???7 km landward of the Middle America trench axis off the Nicoya Peninsula. The primary drilling objective at this site was to identify the age and origin of a regionally extensive and prominent seismic discontinuity, the so-called base-of-slope sediment (BOSS) horizon or surface. The BOSS horizon, which can be traced landward from near the trench to the Nicoya coastal area and parallel to it for hundreds of kilometers, separates a low-velocity (??? 2.0-2.5 km s-1) sequence of slope sediment, from an underlying sequence of much higher-velocity (> 4-4.5 km s-1) rock. Site 1042 reached the acoustically defined BOSS horizon at a below sea level depth of ??? 3900 m and yielded a carbonate-cemented calcarenitic breccia of early-middle Miocene age. Sedimentological, geochemical, paleontological, and cement paragenesis data document that the breccia accumulated in a shallow water depositional environment. On the basis of coastal exposures, the BOSS horizon, as a margin-wide geologic interface, can be temporally and lithostratigraphically correlated to a regional angular unconformity. This unconformity, known as the Mal Pais unconformity, separates Neogene and younger shelf-to-littoral beds from the underlying mafic units of the Mesozoic Nicoya Complex and Cretaceous and early Tertiary sedimentary sequences. At Site 1042 it is inferred that tectonism caused the vertical subsidence of the early Neogene breccia from a shallow to a deep water setting. The Mal Pais unconformity of the BOSS horizon thus connects the rock fabric of the outermost part of margin to that of coastal Nicoya and implies that in the early Neogene the Nicoya shelf extended seaward to near the present

  1. Duration of convergence at the Pacific-Gondwana plate margin: insights from accessory phase petrochronology of the Alpine Schist, New Zealand

    Science.gov (United States)

    Briggs, S. I.; Cottle, J. M.; Smit, M. A.; Arnush, N. F.

    2016-12-01

    The timing, duration and along-strike synchroneity of metamorphism and anataxis in the Alpine Schist of New Zealand is a matter of considerable debate. Our preliminary data indicate that metamorphism resulting in garnet growth occurred from 97 - 75 Ma, and anatectic melting occurred from 80 - 51 Ma. These events are contemporaneous with rifting of Zealandia from East Gondwana, and Tasman Sea spreading from 83 - 52 Ma. An important implication of these results is that Late Cretaceous convergence along the Zealandia segment of the Pacific-Gondwana plate margin may have persisted much later than previously thought, and that convergence and extension occurred coevally in adjacent areas. This poses the question: for how long did convergence continue along the Pacific-Gondwana plate margin during East Gondwana breakup? To fully decipher the multiple stages of the complex metamorphic history recorded in the Alpine Schist, we combine Lu-Hf garnet geochronology with U-Th/Pb and REE analyses of zircon and monazite. We use the newly developed `single-shot laser ablation split stream' (SS-LASS) analysis method to obtain depth profiles through 5-10 µm metamorphic zircon overgrowths at 100 nm depth resolution to constrain both the timing and petrological context of discrete metamorphic zircon (re-)crystallization events recorded in the Alpine Schist. We also employ high spatial resolution LASS analysis to target rare 5 - 20 µm monazite in thin section to augment garnet and zircon data. Our multi-accessory phase petrochronology approach is capable of resolving discrete short-duration thermal events, strengthening the geological interpretation of `mean' Lu-Hf garnet ages and discerning between an episodic versus a prolonged history of metamorphism. In addition, comparison with geochronology from anatectic pegmatites clarifies the temporal relationship between metamorphism and melting in the Alpine Schist, while providing direct constraints on the timing and duration of

  2. Calibration of modelled mixing patterns in loess grain-size distributions: an example from the north-eastern margin of the Tibetan Plateau, China

    NARCIS (Netherlands)

    Vriend, M.G.A.; Prins, M.A.

    2005-01-01

    Genetically meaningful decomposition (unmixing) of sediment grain-size distributions is accomplished with the end-member modelling algorithm. Unmixing of the loess grain-size distributions of a Late Quaternary loess-palaeosol succession from the north-eastern Tibetan Plateau indicates that the loess

  3. Influence of obliquely subducting slab on Pacific-North America shear motion inferred from seismic anisotropy along the Queen Charlotte margin

    Science.gov (United States)

    Cao, L.; Kao, H.; Wang, K.; Wang, Z.

    2016-12-01

    Haida Gwaii is located along the transpressive Queen Charlotte margin between the Pacific (PA) and North America (NA) plates. The highly oblique relative plate motion is partitioned, with the strike-slip component accommodated by the Queen Charlotte Fault (QCF) and the convergent component by a thrust fault offshore. To understand how the presence of a obliquely subducting slab influences shear deformation of the plate boundary, we investigate mantle anisotropy by analyzing shear-wave splitting of teleseismic SKS phases recorded at 17 seismic stations in and around Haida Gwaii. We used the MFAST program to determine the polarization direction of the fast wave (φ) and the delay time (δt) between the fast and slow phases. The fast directions derived from stations on Haida Gwaii and two stations to the north on the Alaska Panhandle are predominantly margin-parallel (NNW). However, away from the plate boundary, the fast direction transitions to WSW-trending, very oblique or perpendicular to the plate boundary. Because the average delay time of 0.6-2.45 s is much larger than values based on an associated local S phase splitting analysis in the same study area, it is reasonable to infer that most of the anisotropy from our SKS analysis originates from the upper mantle and is associated with lattice-preferred orientation of anisotropic minerals. The margin-parallel fast direction within about 100 km of the QCF (average φ = -40º and δt = 1.2 s) is likely induced by the PA-NA shear motion. The roughly margin-normal fast directions farther away, although more scatterd, are consistent with that previously observed in the NA continent and are attributed to the absolute motion of the NA plate. However, the transition between the two regimes based on our SKS analysis appears to be gradual, suggesting that the plate boundary shear influences a much broader region at mantle depths than would be inferred from the surface trace of the QCF. We think this is due to the presence

  4. Beta Diversity of Demersal Fish Assemblages in the North-Eastern Pacific: Interactions of Latitude and Depth

    Science.gov (United States)

    Anderson, Marti J.; Tolimieri, Nick; Millar, Russell B.

    2013-01-01

    Knowledge of broad-scale global patterns in beta diversity (i.e., variation or turnover in identities of species) for marine systems is in its infancy. We analysed the beta diversity of groundfish communities along the North American Pacific coast, from trawl data spanning 32.57°N to 48.52°N and 51 m to 1200 m depth. Analyses were based on both the Jaccard measure and the probabilistic Raup-Crick measure, which accounts for variation in alpha diversity. Overall, beta diversity decreased with depth, and this effect was strongest at lower latitudes. Superimposed on this trend were peaks in beta diversity at around 400–600 m and also around 1000–1200 m, which may indicate high turnover around the edges of the oxygen minimum zone. Beta diversity was also observed to decrease with latitude, but this effect was only observed in shallower waters (800 m. At shallower depths (diversity, including latitude-by-depth interactions, should be integrated with other biodiversity measures in ecosystem-based management and conservation of groundfish communities. PMID:23526960

  5. Phylogenetic placement of Cibicidoides wuellerstorfi (Schwager, 1866) from methane seeps and non-seep habitats on the Pacific margin.

    Science.gov (United States)

    Burkett, A M; Rathburn, A E; Pérez, M E; Levin, L A; Cha, H; Rouse, G W

    2015-01-01

    Benthic foraminifera are among the most abundant groups found in deep-sea habitats, including methane seep environments. Unlike many groups, no endemic foraminiferal species have been reported from methane seeps, and to our knowledge, genetic data are currently sparse for Pacific deep-sea foraminifera. In an effort to understand the relationships between seep and non-seep populations of the deep-sea foraminifera Cibicidoides wuellerstorfi, a common paleo-indicator species, specimens from methane seeps in the Pacific were analyzed and compared to one another for genetic similarities of small subunit rDNA (SSU rDNA) sequences. Pacific Ocean C. wuellerstorfi were also compared to those collected from other localities around the world (based on 18S gene available on Genbank, e.g., Schweizer et al., 2009). Results from this study revealed that C. wuellerstorfi living in seeps near Costa Rica and Hydrate Ridge are genetically similar to one another at the species level. Individuals collected from the same location that display opposite coiling directions (dextral and sinstral) had no species level genetic differences. Comparisons of specimens with genetic information available from Genbank (SSU rDNA) showed that Pacific individuals, collected for this study, are genetically similar to those previously analyzed from the North Atlantic and Antarctic. These observations provide strong evidence for the true cosmopolitan nature of C. wuellerstorfi and highlight the importance of understanding how these microscopic organisms are able to maintain sufficient genetic exchange to remain within the same species between seep and non-seep habitats and over global distances. © 2014 John Wiley & Sons Ltd.

  6. Food Web Bioaccumulation Model for Resident Killer Whales from the Northeastern Pacific Ocean as a Tool for the Derivation of PBDE-Sediment Quality Guidelines.

    Science.gov (United States)

    Alava, Juan José; Ross, Peter S; Gobas, Frank A P C

    2016-01-01

    Resident killer whale populations in the NE Pacific Ocean are at risk due to the accumulation of pollutants, including polybrominated diphenyl ethers (PBDEs). To assess the impact of PBDEs in water and sediments in killer whale critical habitat, we developed a food web bioaccumulation model. The model was designed to estimate PBDE concentrations in killer whales based on PBDE concentrations in sediments and the water column throughout a lifetime of exposure. Calculated and observed PBDE concentrations exceeded the only toxicity reference value available for PBDEs in marine mammals (1500 μg/kg lipid) in southern resident killer whales but not in northern resident killer whales. Temporal trends (1993-2006) for PBDEs observed in southern resident killer whales showed a doubling time of ≈5 years. If current sediment quality guidelines available in Canada for polychlorinated biphenyls are applied to PBDEs, it can be expected that PBDE concentrations in killer whales will exceed available toxicity reference values by a large margin. Model calculations suggest that a PBDE concentration in sediments of approximately 1.0 μg/kg dw produces PBDE concentrations in resident killer whales that are below the current toxicity reference value for 95 % of the population, with this value serving as a precautionary benchmark for a management-based approach to reducing PBDE health risks to killer whales. The food web bioaccumulation model may be a useful risk management tool in support of regulatory protection for killer whales.

  7. Circum-Pacific accretion of oceanic terranes to continental blocks: accretion of the Early Permian Dun Mountain ophiolite to the E Gondwana continental margin, South Island, New Zealand

    Science.gov (United States)

    Robertson, Alastair

    2016-04-01

    Accretionary orogens, in part, grow as a result of the accretion of oceanic terranes to pre-existing continental blocks, as in the circum-Pacific and central Asian regions. However, the accretionary processes involved remain poorly understood. Here, we consider settings in which oceanic crust formed in a supra-subduction zone setting and later accreted to continental terranes (some, themselves of accretionary origin). Good examples include some Late Cretaceous ophiolites in SE Turkey, the Jurassic Coast Range ophiolite, W USA and the Early Permian Dun Mountain ophiolite of South Island, New Zealand. In the last two cases, the ophiolites are depositionally overlain by coarse clastic sedimentary rocks (e.g. Permian Upukerora Formation of South Island, NZ) that then pass upwards into very thick continental margin fore-arc basin sequences (Great Valley sequence, California; Matai sequence, South Island, NZ). Field observations, together with petrographical and geochemical studies in South Island, NZ, summarised here, provide evidence of terrane accretion processes. In a proposed tectonic model, the Early Permian Dun Mountain ophiolite was created by supra-subduction zone spreading above a W-dipping subduction zone (comparable to the present-day Izu-Bonin arc and fore arc, W Pacific). The SSZ oceanic crust in the New Zealand example is inferred to have included an intra-oceanic magmatic arc, which is no longer exposed (other than within a melange unit in Southland), but which is documented by petrographic and geochemical evidence. An additional subduction zone is likely to have dipped westwards beneath the E Gondwana margin during the Permian. As a result, relatively buoyant Early Permian supra-subduction zone oceanic crust was able to dock with the E Gondwana continental margin, terminating intra-oceanic subduction (although the exact timing is debatable). The amalgamation ('soft collision') was accompanied by crustal extension of the newly accreted oceanic slab, and

  8. Late Pleistocene to Holocene sea surface temperature development in the NW-Pacific and its marginal seas

    Science.gov (United States)

    Max, L.; Riethdorf, J.; Tiedemann, R.; Nuernberg, D.; Abelmann, A.

    2011-12-01

    The subarctic N-Pacific acts as terminus of the modern ocean circulation with water masses highly enriched in dissolved nutrients and carbon dioxide. Today a permanent halocline results in strong upper-ocean stratification, which hampers the atmospheric-oceanic gas exchange and the supply of nutrients into the photic zone. Past changes in sea surface conditions in the subarctic Pacific are proposed to impact climate but are less well known than in the N-Atlantic. The onset and timing of past oceanographic changes are suggested to be driven by changes in oceanic circulation and/or atmospheric teleconnections. Here, we present a suite of sediment records from the continental slope off Kamchatka (NW-Pacific), the western Bering Sea and the Sea of Okhotsk. All cores were obtained well above the shallow carbonate compensation depth (CCD) and provide sufficient material for detailed late Pleistocene to Holocene reconstructions of past changes in oceanographic conditions. The stratigraphy is based on high-resolution X-ray fluorescence scans (XRF) together with spectrophotographic measurements (color b*), which were aligned to the NGRIP oxygen isotope record and further confirmed by AMS 14C ages. Alkenone measurements were applied to reconstruct sea surface temperatures (SST) by use of the Uk'37 index (Müller et al., 1998). Our SST reconstructions span the last ˜15 ka BP. Prior alkenone concentrations were below the detection limit and thus indicate the absence of coccolithophoride blooms during the last glacial. After ˜14.7 ka BP the SST records in the NW-Pacific and western Bering Sea indicate an early increase in SST (Bolling/Allerod), followed by a cold spell at ˜12.8 ka BP (Younger Dryas) and the onset of warm Holocene climate conditions around ˜10.7 ka BP. During the early Holocene the SST increased by up to 4°C. This pronounced warming is interpreted as amplified stratification of the upper water column, which is paralleled by laminae formation at the sea

  9. Phylogenetic Diversity of aprA Genes in Subseafloor Sediments on the Northwestern Pacific Margin off Japan.

    Science.gov (United States)

    Aoki, Masataka; Kakiuchi, Ryota; Yamaguchi, Takashi; Takai, Ken; Inagaki, Fumio; Imachi, Hiroyuki

    2015-01-01

    Markedly diverse sequences of the adenosine-5'-phosphosulfate reductase alpha subunit gene (aprA), which encodes a key enzyme in microbial sulfate reduction and sulfur oxidation, were detected in subseafloor sediments on the northwestern Pacific off Japan. The aprA gene sequences were grouped into 135 operational taxonomic units (90% sequence identity), including genes related to putative sulfur-oxidizing bacteria predominantly detected in sulfate-depleted deep sediments. Our results suggest that microbial ecosystems in the subseafloor biosphere have phylogenetically diverse genetic potentials to mediate cryptic sulfur cycles in sediments, even where sulfate is rarely present.

  10. Effects of biochemical and physical processes on concentrations and size distributions of dimethylaminium and trimethylaminium in atmospheric particles from marginal seas of China to the northwest Pacific Ocean

    Science.gov (United States)

    Hu, Q.; Yao, X.; Qu, K.; Cui, Z.; Gao, H.; Xie, H.

    2017-12-01

    This study aim to assess the effects of concentrations and size distributions of aminium ions in atmospheric particles from offshore to open oceans. Size-segregated dimethylaminium (DMA+) and trimethylaminium (TMA+) in atmospheric particles were measured during March-May, 2014. One cruise was over marginal seas of China, in which the concentrations of DMA+ and TMA+ in PM0.056-10 varied from 0.08 nmol m-3 to 0.43 nmol m-3 and from 0.10 to 0.27 nmol m-3, respectively. The two ions both had good positive correlations with subsurface chlorophyll-a maximum and salinity, respectively. The highest concentrations of (DMA+ + TMA+) were observed during cyanobacteria bloom period which happened in subsurface water. The results implied that the concentrations of DMA+ (TMA+) in marine atmospheric particles might be influenced by phytoplankton quantities and species in subsurface seawater. Another cruise was carried out from marginal seas of China to the northwest Pacific Ocean (NWPO). The concentrations of DMA+ and TMA+ in PM0.056-1.8 varied from 0.19 nmol m-3 to 1.53 nmol m-3 and from 0.57 to 3.85 nmol m-3, respectively. The highest (lowest) concentrations of (DMA+ + TMA+) were observed near the cyclonic (anticyclonic) eddy, indicating that the cyclonic (anticyclonic) eddy with high (low) chlorophyll-a enhanced (suppressed) DMA+ (TMA+) production in atmospheric particles. In addition, the dominant particle modes less than 0.2 μm for DMA+ (TMA+) were observed, ie., 0.13±0.02 μm for DMA+ over marginal seas of China, and 0.08±0.00 μm for TMA+ in NWPO, but if they were emitted via bubble bursting needed to be further researched.

  11. Assessing oxygen depletion in the Northeastern Pacific Ocean during the last deglaciation using I/Ca ratios from multiple benthic foraminiferal species

    Science.gov (United States)

    Taylor, M. A.; Hendy, I. L.; Chappaz, A.

    2017-08-01

    Paleo-redox proxies are crucial for reconstructing past bottom water oxygen concentration changes brought about by ocean circulation and marine productivity shifts in response to climate forcing. Carbonate I/Ca ratios of multiple benthic foraminifera species from Ocean Drilling Program Hole 1017E—a core drilled within the Californian oxygen minimum zone (OMZ), on the continental slope—are employed to reexamine the transition from the well-oxygenated last glacial into poorly oxygenated modern conditions. The redox and export productivity history of this site is constrained by numerous proxies used to assess sensitivity of I/Ca ratios of benthic foraminifera to changes in bottom and pore water O2 concentrations. Reconstructed iodate (IO3-) availability is from the I/Ca ratio of epifaunal (Cibicidoides sp.), shallow infaunal (Uvigerina peregrina), and deep infaunal (Bolivina spissa) foraminifera. The reconstructed IO3- availability profile is used to determine the contribution of bottom water O2 relative to oxidant demand on pore water O2 concentrations. These results suggest that high export productivity on the California Margin drove low pore water O2 concentrations during the Bølling. In contrast, low bottom water O2 concentrations at 950 m water depth only contributed to reduced sediments during the Allerød. Increased contribution of modified North Pacific Intermediate Water to the California Current System ventilated the California OMZ during the late glacial and the Younger Dryas such that water overlying the site was oxygenated. These results highlight the promising potential of this new proxy for understanding the relative influence of bottom water O2 concentration and pore water oxidant demand on OMZs.

  12. A comparison of geochemical exploration techniques and sample media within accretionary continental margins: an example from the Pacific Border Ranges, Southern Alaska, U.S.A.

    Science.gov (United States)

    Sutley, S.J.; Goldfarb, R.J.; O'Leary, R. M.; Tripp, R.B.

    1990-01-01

    The Pacific Border Ranges of the southern Alaskan Cordillera are composed of a number of allochthonous tectonostratigraphic terranes. Within these terranes are widespread volcanogenic, massive sulfide deposits in and adjacent to portions of accreted ophiolite complexes, bands and disseminations of chromite in accreted island-arc ultramafic rocks, and epigenetic, gold-bearing quartz veins in metamorphosed turbidite sequences. A geochemical pilot study was undertaken to determine the most efficient exploration strategy for locating these types of mineral deposits within the Pacific Border Ranges and other typical convergent continental margin environments. High-density sediment sampling was carried out in first- and second-order stream channels surrounding typical gold, chromite and massive sulfide occurrences. At each site, a stream-sediment and a panned-concentrate sample were collected. In the laboratory, the stream sediments were sieved into coarse-sand, fine- to medium-sand, and silt- to clay-size fractions prior to analysis. One split of the panned concentrates was retained for analysis; a second split was further concentrated by gravity separation in heavy liquids and then divided into magnetic, weakly magnetic and nonmagnetic fractions for analysis. A number of different techniques including atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and semi-quantitative emission spectrography were used to analyze the various sample media. Comparison of the various types of sample media shows that in this tectonic environment it is most efficient to include a silt- to clay-size sediment fraction and a panned-concentrate sample. Even with the relatively low detection limits for many elements by plasma spectrometry and atomic absorption spectrometry, anomalies reflecting the presence of gold veins could not be identified in any of the stream-sediment fractions. Unseparated panned-concentrate samples should be analyzed by emission

  13. Deglacial ocean warming and marine margin retreat of the Cordilleran Ice Sheet in the North Pacific Ocean

    Science.gov (United States)

    Taylor, M. A.; Hendy, I. L.; Pak, D. K.

    2014-10-01

    A new, high-resolution planktonic foraminiferal Mg/Ca-based ocean temperature record has been generated for deep sea core MD02-2496, sited offshore of Vancouver Island, Western Canada during the last deglaciation (21-12 ka). The relationship between Cordilleran Ice Sheet (CIS) retreat and changing regional ocean temperatures has been reconstructed through glaciomarine sediments in MD02-2496 that capture tidewater glacier response to surface ocean thermal forcing. At CIS maximum extent, the marine margin of the ice sheet advanced onto the continental shelf. During this interval, ocean temperatures recorded by surface dwelling Globigerina bulloides remained a relatively constant ∼7.5 °C while subsurface dwelling Neogloboquadrina pachyderma (s.) recorded temperatures of ∼5 °C. These ocean temperatures were sufficiently warm to induce significant melt along the tidewater ice terminus similar to modern Alaskan tidewater glacial systems. During the deglacial retreat of the CIS, the N. pachyderma temperature record shows two distinct warming steps of ∼ 2 and 2.5 °C between 17.2-16 and 15.5-14 ka respectively, coincident with ice rafting events from the CIS, while G. bulloides records an ∼ 3 °C warming from 15 to 14 ka. We hypothesize that submarine melting resulting from relatively warm ocean temperatures was an important process driving ice removal from CIS tidewater glaciers during the initial stages of deglaciation.

  14. Fire history and climate characteristics during the last millennium of the Great Hinggan Mountains at the monsoon margin in northeastern China

    Science.gov (United States)

    Gao, Chuanyu; He, Jiabao; Zhang, Yan; Cong, Jinxin; Han, Dongxue; Wang, Guoping

    2018-03-01

    The northeastern region of China, at the limit of the summer monsoon, is characterized by the presence of mountains that influenced by the Asian summer monsoon on one side and the westerlies on the other; however, few studies have compared the environmental characteristics on the two sides of these mountains. In this study, two peatland cores from the western and eastern sides of the Great Hinggan Mountains were investigated to better understand the climatic and environmental conditions and the measurements of black carbon (BC) and δ13C-BC were used to reconstruct the fire history and environmental characteristics during the last millennium. Our results showed that the variations in the δ13C-BC values are more sensitive to climate changes than the BC fluxes, and the climate forcing mechanisms differed between the two sides of the mountains. Lower δ13C-BC values around 500 cal yr BP on the western side of the mountains indicated climate conditions were wetter than that on the eastern side, and were influenced by low sea surface temperatures in the North Atlantic Ocean. The region east of the mountains was mainly influenced by the strong Asian summer monsoon, and the decreasing of δ13C-BC values indicated climate conditions became wetter from 250 cal yr BP to the present and were wetter than that on the western side after 150 cal yr BP. Moreover, when one of these two forcing factors weakened and the other strengthened (e.g. from 400 to 150 cal yr BP), climate conditions in these two sides were similar.

  15. Establishing demographic parameters for loggerhead turtles in the northeastern Pacific Ocean: growth rates, age determination, annual habitat use, and population connectivity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Loggerhead turtles nesting in Japan (i.e. the source rookery for individuals along the U.S. West coast and Pacific Mexico) have recently been declared a Distinct...

  16. Natural variability of pCO2 and pH in the Atlantic and Pacific coastal margins of the U.S

    Science.gov (United States)

    Sutton, A. J.; Sabine, C. L.; Feely, R. A.; Newton, J.; Salisbury, J.; Vandemark, D. C.; Musielewicz, S. B.; Maenner-Jones, S.; Bott, R.; Lawrence-Slavas, N.

    2011-12-01

    The discovery that seawater chemistry is changing as a result of carbon dioxide (CO2) emissions, referred to as "ocean acidification", has prompted a large effort to understand how this changing chemistry will impact marine life. Changes in carbon chemistry have been documented in the open ocean; however, in dynamic coastal systems where many marine species live, ocean acidification and the natural biogeochemical variability that organisms are currently exposed to are poorly quantified. In 2010 we began equipping coastal moorings currently measuring pCO2 with pH and other biogeochemical sensors to measure ocean acidification parameters at 3 hour intervals in the surface water. Here we present the magnitude and diurnal to seasonal variability of pCO2 and pH during the first year of observations at 2 sites in the Atlantic and Pacific coastal margins of the U.S.: the Gulf of Maine and outer coast of Washington state. Both the magnitude and range of pCO2 and pH values were much greater at the coastal moorings compared to the open ocean mooring at Ocean Station Papa in the North Pacific and also varied between the two coastal mooring sites. We observed maximum pCO2 values in coastal waters exceeding predicted values for the open ocean at 2x pre-industrial CO2 levels. The range of pCO2 and pH values during this time series was approximately 4 times the range observed at open ocean mooring Papa (2007-2011 time series). In many cases, large variance was observed at short time scales, with values fluctuating more than 200 μatm pCO2 and 0.2 pH between 3-hour cycles. These types of observations are critical for understanding how ocean acidification will manifest in naturally dynamic coastal systems and for informing the experimental design of species response studies that aim to mimic carbon chemistry experienced by coastal marine organisms.

  17. Record of Permian-Early Triassic continental arc magmatism in the western margin of the Jiamusi Block, NE China: petrogenesis and implications for Paleo-Pacific subduction

    Science.gov (United States)

    Yang, Hao; Ge, Wenchun; Dong, Yu; Bi, Junhui; Wang, Zhihui; Ji, Zheng; Yang, H.; Ge, W. C.; Dong, Y.; Bi, J. H.; Wang, Z. H.; Ji, Z.

    2017-09-01

    In this paper, we report zircon U-Pb ages, Hf isotopes and whole-rock geochemical data for the Permian to Early Triassic granitoids from the western margin of the Jiamusi Block (WJB), NE China. The intermediate to felsic (SiO2 = 59.67-74.04 wt%) granitoids belong to calc-alkaline series and are characterized by enrichments in light rare earth elements and large ion lithophile elements with pronounced negative Nb, Ta and Ti anomalies, revealing typical continental magmatic arc geochemical signatures. The zircon U-Pb determinations on the granodiorite, monzogranite, syenogranite and quartz diorite samples yielded ages between ca. 275-245 Ma, which, together with the published coeval intrusive rocks, indicates that Permian to Early Triassic continental arc magmatism occurred extensively in the WJB. The low and mainly negative zircon ɛ Hf( t) values between -7.6 and +1.6 and the zircon Hf model ages of 1.2-1.8 Ga, which are significantly older than their crystallization ages, suggest that they were mainly derived from reworking of ancient crustal materials with a limited input of juvenile components. The geochemical systematics and petrogenetic considerations indicate that the studied granitoids were generated from a zone of melting, assimilation, storage, and homogenization, i.e., a MASHed zone at the base of Paleo- to Mesoproterozoic continental crust, where large portions of igneous rocks and minor clay-poor sediments involved in the source region. In combination with regional geological data, we argue that the Jiamusi Block was unlikely the rifted segment of the Songliao Block and two possible geodynamical models were proposed to interpret the formation of the ca. 275-245 Ma granitoids in the WJB. In the context of Permian global plate reconstruction, we suggest that Paleo-Pacific plate subduction was initiated in the Permian to Early Triassic beneath the Jiamusi Block, and even whole eastern NE China.

  18. Modeling {sup 137}Cs bioaccumulation in the salmon–resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident

    Energy Technology Data Exchange (ETDEWEB)

    Alava, Juan José, E-mail: jalavasa@sfu.ca; Gobas, Frank A.P.C.

    2016-02-15

    To track the long term bioaccumulation of {sup 137}Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for {sup 137}Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that {sup 137}Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of {sup 137}Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. {sup 137}Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the {sup 137}Cs activity in species of the food web, based on current measurements and forecasts of {sup 137}Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term {sup 137}Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current {sup 137}Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term {sup 137}Cs activities and may be good sentinels for monitoring {sup 137}Cs in the region. Assessment of the long term consequences of {sup 137}Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. - Highlights: • A food web bioaccumulation model to assess the biomagnification of {sup 137}Cs is developed. • Cesium 137 exhibits bioaccumulation over time as simulated by the model. • Predicted activities in marine biota are below {sup 137}Cs-food consumption benchmarks. • Long-term monitoring of {sup 137}Cs in the ocean will improve the model predictions.

  19. Modeling 137Cs bioaccumulation in the salmon–resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident

    International Nuclear Information System (INIS)

    Alava, Juan José; Gobas, Frank A.P.C.

    2016-01-01

    To track the long term bioaccumulation of 137 Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for 137 Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that 137 Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of 137 Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. 137 Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the 137 Cs activity in species of the food web, based on current measurements and forecasts of 137 Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term 137 Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current 137 Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term 137 Cs activities and may be good sentinels for monitoring 137 Cs in the region. Assessment of the long term consequences of 137 Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. - Highlights: • A food web bioaccumulation model to assess the biomagnification of 137 Cs is developed. • Cesium 137 exhibits bioaccumulation over time as simulated by the model. • Predicted activities in marine biota are below 137 Cs-food consumption benchmarks. • Long-term monitoring of 137 Cs in the ocean will improve the model predictions.

  20. Modeling (137)Cs bioaccumulation in the salmon-resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident.

    Science.gov (United States)

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

    To track the long term bioaccumulation of (137)Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for (137)Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that (137)Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of (137)Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. (137)Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the (137)Cs activity in species of the food web, based on current measurements and forecasts of (137)Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term (137)Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current (137)Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term (137)Cs activities and may be good sentinels for monitoring (137)Cs in the region. Assessment of the long term consequences of (137)Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Bathymetric Atlas of the North Pacific Ocean.

    Science.gov (United States)

    1978-01-01

    of volcanic ash layers and turbidito% ini 1956. Clipperton fracture zone in the northeastern equa- the north Pacific, Gal. Soc. Amer. Bull., v. 80, p...1964. Galapagos Rise in the southeastern Pacific, Deep- 1961. Geology of the sea floor east of Guadalupe Island, Sea Research, v. 11, p. 233.242.I...charts. 52 p. Richards, A.F. Monard, H.W. 1959. Geology of the Islas Revillagigedo, Mexico, Volcan . 1955. Deformation of the northeastern Pacific

  2. On the Paleotectonic Evolution of the Pacific Margin of Southern Mexico, the Maya and Juchatengo Terranes and Chochal Formation Guatemala:Insights from Paleomagnetic and Isotopic Studies

    Science.gov (United States)

    Guerrero Garcia, J. C.; Herrero-Bervera, E.

    2009-05-01

    In the paleogeographic reconstruction of Mexico and northern Central America, evidence shows that the entire region is a collage of suspect terranes transported from abroad, whose timing and sense of motion are now beginning to be understood. Among these, the Chortis block and the Baja California Peninsula have been proposed as pieces of continent separated from the Pacific coast of southwestern Mexico, that have moved either southeastward by the Farallon plate or northwestward by the Kula plate. Isotopic mineral ages from coastal granites along the coast from Puerto Vallarta, Jalisco (80 Ma) to Puerto Angel, Oaxaca (11 Ma) record systematic decrease of cooling ages from NW to SE. These results also constrain the position of the Kula- Farallon spreading axis north of Puerto Vallarta. Previous studies mainly confined to the northern margin of the Chortis block, confirmed a left-lateral displacement of 130 km in Neogene time. Further studies suggested times of detachment increased to 30 Ma, 40 Ma, and 66 Ma. We conclude that several indicators, namely: (a) the truncated nature of the Pacific coast of SW Mexico; (b) the genesis of the Kula-Farallon ridge at 85 Ma; (c) the 2,600 km of northward transport of Baja British Columbia from the present-day latitude of the Baja California Peninsula, beginning at 85 Ma; (d) the paleomagnetic counterclockwise rotations of areas both in the Chortis block and along the Mexican coast, during Late Cretaceous-Paleogene time, and (e) the systematic NW-SE decrease of radiometric dates beginning at 85 Ma in Puerto Vallarta and ending at approximately 11 Ma in Puerto Angel, Oaxaca , point to this time and region for the onset of strike-slip drifting of the Chortis block toward its current position. On the other hand, in the reconstruction of past movements of tectonic plates, the determination of reliable paleomagnetic poles is of utmost importance. To achieve accurate results, a full knowledge of the rock magnetic properties of the

  3. Shear wave velocity structure in the lithosphere and asthenosphere across the Southern California continent and Pacific plate margin using inversion of Rayleigh wave data from the ALBACORE project.

    Science.gov (United States)

    Price, A. C.; Weeraratne, D. S.; Kohler, M. D.; Rathnayaka, S.; Escobar, L., Sr.

    2015-12-01

    The North American and Pacific plate boundary is a unique example of past subduction of an oceanic spreading center which has involved oceanic plate capture and inception of a continental transform boundary that juxtaposes continental and oceanic lithosphere on a single plate. The amphibious ALBACORE seismic project (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) deployed 34 ocean bottom seismometers (OBS) on 15-35 Ma seafloor and offers a unique opportunity to compare the LAB in continental and oceanic lithosphere in one seismic study. Rayleigh waves were recorded simultaneously by our offshore array and 82 CISN network land stations from 2010-2011. Here we predict phase velocities for a starting shear wave velocity model for each of 5 regions in our study area and compare to observed phase velocities from our array in a least-squares sense that produces the best fit 1-D shear wave velocity structure for each region. Preliminary results for the deep ocean (seafloor 25-32 Ma) indicates high velocities reaching 4.5 km/s at depths of 50 km associated with the lithosphere for seafloor 25-32 Ma. A negative velocity gradient is observed below this which reaches a minimum of 4.0 km/s at 160 km depth. The mid-ocean region (age 13-25 Ma) indicates a slightly lower magnitude and shallower LVZ. The Inner Borderland displays the highest lithospheric velocities offshore reaching 4.8 km/s at 40 km depth indicating underplating. The base of the LVZ in the Borderland increases sharply from 4.0 km/s to 4.5 km/s at 80-150 km depth indicating partial melt and compositional changes. The LVZ displays a very gradual positive velocity gradient in all other regions such as the deep seafloor and continent reaching 4.5 km/s at 300 km depth. The deep ocean, Borderlands, and continental region each have unique lithospheric velocities, LAB depths, and LVZ character that indicate stark differences in mantle structure that occur on a

  4. Cretaceous high-pressure metamorphic belts of the Central Pontides (northern Turkey): pre-collisional Pacific-type accretionary continental growth of Laurasian Margin

    Science.gov (United States)

    Aygul, Mesut; Okay, Aral I.; Oberhaensli, Roland; Sudo, Masafumi

    2014-05-01

    Ma. One of the Cld-micaschist, exposed to the South, gives a 92 ± 2 Ma age. This documents a southward younging of metamorphism within the accretionary prism. A mid-Jurassic (160 Ma) age, previously reported from a micaschist in the southern part of Domuzdaǧ Complex, is also supported in this study. These rocks however differ from the Cretaceous HP unit both in lithology and degree of metamorphism (P: 10 ± 2 Kbar, T: 620 ± 30°C; Okay et al. 2013). It is not clear whether these rocks indicate episodic subduction process or represent tectonically emplaced slivers of the overriding plate which has widespread Mid-Jurassic high-grade metamorphic rocks and intrusions. The Cretaceous accretionary complex structurally overlies an arc-related low-grade metavolcanic unit, which is thrusted over the ophiolitic rocks of the main Tethyan İzmir-Ankara-Erzincan Suture zone that separates the Pontides from the Gondwana-derived terranes. In the tectonic framework discussed above, the study area represents subduction and accretion related units, which are sandwiched between the southern Laurasian active margin and the Gondwana-derived Kırşehir Block without any continental fragments. This indicates that Pacific-type pre-collisional accretion has a major role in the Tethyan geology of the Central Pontides during Cretaceous. Okay et al. (2013) Tectonics 32: 1247-1271.

  5. Contributions to knowledge of the continental margin of Uruguay. Uruguayan continental margin: Physiographic and seismic analysis

    International Nuclear Information System (INIS)

    Preciozzi, F

    2014-01-01

    This work is about the kind of continental margins such as a )Atlantic type passive margins which can be hard or soft b) An active or Pacific margins that because of the very frequent earthquakes develop a morphology dominated by tectonic processes. The Uruguayan continental margin belongs to a soft Atlantic margin

  6. Status of Exosphaeroma amplicauda (Stimpson, 1857, E. aphrodita (Boone, 1923 and description of three new species (Crustacea, Isopoda, Sphaeromatidae from the north-eastern Pacific

    Directory of Open Access Journals (Sweden)

    Adam Wall

    2015-05-01

    Full Text Available Exosphaeroma amplicauda (Stimpson, 1857 from the west coast of North America is reviewed and redescribed and revealed to be a group of closely related species. A neotype is designated and the species redescribed based on the neotype and topotypic specimens. Exosphaeroma amplicauda is known only from the coast of California, at Marin, Sonoma and San Mateo Counties. E. aphrodita (Boone, 1923, type locality La Jolla, California and previously considered nomen dubium is taken out of synonymy and re-validated. A further three species: E. paydenae sp. n., E. russellhansoni sp. n., and E. pentcheffi sp. n. are described herein. Sphaeroma octonctum Richardson, 1899 is placed into junior synonymy with Exosphaeroma amplicauda. A key to the Pacific West Coast Exosphaeroma is provided.

  7. Investigation on marine radioactivity in radioactive waste dumping areas in the northwest Pacific Ocean and its marginal seas. JAERI's activities in the second Japanese-Korean-Russian joint expedition 1995

    International Nuclear Information System (INIS)

    Togawa, Orihiko; Kobayashi, Takuya; Kitamura, Toshikatsu; Mizushima, Toshihiko; Yabuuchi, Noriaki

    1998-10-01

    JAERI participated in the second Japanese-Korean-Russian joint expedition which was conducted from August 15 to September 15, 1995. The objective of the expedition was to investigate the radiological contamination in the marine environment due to radioactive wastes dumped by the former USSR and the Russian Federation in the northwest Pacific Ocean and its marginal seas, and due to radioactive wastes which the Republic of Korea and Japan experimentally dumped in their territorial waters in the past. During the expedition, samples of seawater, seabed sediment and biota were collected in both each radioactive waste dumping area and its corresponding background area. On-board measurements of the concentrations of gamma-ray emitting radionuclides in seawater, adsorbents and sediment were also carried out at each sampling station. JAERI took charge of the on-board measurements, on-land measurements of pre-filters and adsorbents brought back from the expedition, and preparation and transport of equipment and materials for the Japanese delegation. The only anthropogenic radionuclide detected in seawater and sediment samples was 137 Cs in on-board measurements during the expedition. The results from on-board measurements agreed with those from on-land measurements, showing a systematic overestimate. However the 137 Cs concentrations were low and no significant difference in concentration was observed between the dumping areas and corresponding background areas. The levels also compared well with those due to global fallout generally observed in the northwest Pacific Ocean and its marginal seas. (author)

  8. Historical insights on growth rates of the reef-building corals Pavona gigantea and Porites panamensis from the Northeastern tropical Pacific.

    Science.gov (United States)

    Tortolero-Langarica, J J A; Carricart-Ganivet, J P; Cupul-Magaña, A L; Rodríguez-Troncoso, A P

    2017-12-01

    Historical coral growth assessed by sclerochronology records provides an environmental retrospective and future perspective on the maintenance of coral-reef ecosystems. Three growth parameters, extension rate, skeletal density, and calcification rate were evaluated over the past two decade's interval (1988-2013) in different gender of two massive corals Pavona gigantea and Porites panamensis. The species P. gigantea calcified two-times faster (0.84 ± 0.29 g cm -2 yr -1 ) than P. panamensis (0.36 ± 0.15 g cm -2 yr -1 ); and male colonies presents13-58% higher calcification rates than females. Annual growth parameters do not show significant trends over the period 1988-2013, but significant, growth disruption associated with ENSO events. The data presented here suggest that P.gigantea and P.panamensis from the area have developed phenotypic plasticity to a wide range of environmental condition; the life history of both species is reflected in their calcification rates during both optimal and non-optimal conditions over the last two decades. Massive species develop denser structures that provide a permanent habitat to many marine species and contributes to the long-term maintenance of coral reef communities in the eastern tropical Pacific. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Neogene to Quaternary stratigraphic evolution of the Antarctic Peninsula, Pacific Margin offshore of Adelaide Island: Transitions from a non-glacial, through glacially-influenced to a fully glacial state

    Science.gov (United States)

    Hernández-Molina, F. Javier; Larter, Robert D.; Maldonado, Andrés

    2017-09-01

    A detailed morphologic and seismic stratigraphic analysis of the continental margin offshore of Adelaide Island on the Pacific Margin of the Antarctic Peninsula (PMAP) is described based on the study of a regular network of reflection multichannel seismic profiles and swath bathymetry. We present an integrated study of the margin spanning the shelf to the continental rise, establish novel chronologic constraints and offer new interpretations on tectonic evolution and environmental changes affecting the PMAP. The stratigraphic stacking patterns record major shifts in the depositional style of the margin that outline three intervals in its evolution. The first non-glacial interval (Early Cretaceous to middle Miocene) encompasses a transition from an active to a passive margin (early Miocene). The second glacially-influenced interval (middle to late Miocene) is marked by pronounced aggradational sedimentary stacking and subsidence. Ice sheets advanced over the middle shelf of the margin at the end of this second interval, while the outer shelf experienced rare progradational events. The third, fully glaciated interval shows clear evidence of glacially dominated conditions on the margin. This interval divides into three minor stages. During the first stage (late Miocene to the beginning of the Pliocene), frequent grounded ice advances to the shelf break began, depositing an initial progradational unit. A major truncation surface marked the end of this stage, which coincided with extensive mass transport deposits at the base of the slope. During the second progradational glacial margin stage (early Pliocene to middle Pleistocene), stacking patterns record clearly prograding glacial sequences. The beginning of the third aggradational glacial margin stage (middle Pleistocene to present) corresponded to an important shift in global climate during the Mid-Pleistocene Transition. Morphosedimentary characteristics observed along the margin today began to develop during the

  10. Mazama ash in the northeastern pacific.

    Science.gov (United States)

    Nelson, C H; Kulm, L D; Carlson, P R; Duncan, J R

    1968-07-05

    Volcanic glass in marine sediments off Oregon and Washington correlates with continental deposits of Mount Mazama ash by stratigraphic position, refractive index, and radiocarbon dating. Ash deposited in the abyssal regions by turbidity currents is used for tracing of the dispersal routes of postglacial sediments and for evaluation of marine sedimentary processes.

  11. The Mesozoic-Cenozoic igneous intrusions and related sediment-dominated hydrothermal activities in the South Yellow Sea Basin, the Western Pacific continental margin

    Science.gov (United States)

    Yumao, Pang; Xunhua, Zhang; Guolin, Xiao; Luning, Shang; Xingwei, Guo; Zhenhe, Wen

    2018-04-01

    Various igneous complexes were identified in multi-channel seismic reflection profiles from the South Yellow Sea Basin. It is not rare that magmatic intrusions in sedimentary basins cause strong thermal perturbations and hydrothermal activities. Some intrusion-related hydrothermal vent complexes have been identified and they are considered to originate from the deep sedimentary contact aureole around igneous intrusions and terminate in upper vents structures, and are linked by a vertical conduit system. The upper vent complexes are usually eye-shaped, dome-shaped, fault-related, crater-shaped or pock-shaped in seismic profiles. A schematic model was proposed to illustrate the structures of different types of hydrothermal vent complexes. A conceptual conduit model composed of an upper pipe-like part and a lower branching part was also derived. Hydrothermal vent complexes mainly developed during the Middle-Late Cretaceous, which is coeval with, or shortly after the intrusion. The back-arc basin evolution of the area which is related to the subduction of the Paleo-Pacific plate during the Mesozoic-Cenozoic may be the principal factor for voluminous igneous complexes and vent complexes in this area. It is significant to study the characteristics of igneous complexes and related hydrothermal vent complexes, which will have implications for the future study of this area.

  12. South Pacific intermediate water oxygen depletion at the onset of the Paleocene-Eocene thermal maximum as depicted in New Zealand margin sections

    Science.gov (United States)

    Nicolo, Micah J.; Dickens, Gerald R.; Hollis, Christopher J.

    2010-11-01

    Extreme global warming and massive input of 13C-depleted carbon into the exogenic carbon cycle characterize the Paleocene-Eocene thermal maximum (PETM) circa 55.5 Ma. Previous work indicates that dissolved O2 concentrations dropped in some regions of the ocean during this event, but spatial, temporal, and causal relationships between warming, carbon input, and O2 deficiency remain elusive. We present lithologic, carbon isotopic, and trace fossil results from outcrops in New Zealand that clarify this issue. Sections exposed at Mead and Dee Streams in eastern Marlborough, South Island, contain expanded sedimentary intervals that were deposited before, during, and after the PETM on an upper continental slope. The PETM in these intervals is characterized by enhanced siliciclastic deposition, a hallmark negative carbon isotope excursion, and a loss of bioturbation. Importantly, however, the latter only occurs during the prominent drop in δ13C and not during its recovery. Our results suggest that South Pacific intermediate waters became hypoxic coincident to carbon injection at the start of the PETM. While higher sea surface temperatures throughout the PETM would have decreased the dissolved oxygen content of sinking surface waters, we argue here that oxygen depletion was driven by some combination of elevated temperature, water column stratification, and intermediate water methane oxidation.

  13. Chemical composition of aerosol, sea fog, and rainwater in the marine boundary layer of the northwestern North Pacific and its marginal seas

    Science.gov (United States)

    Sasakawa, Motoki; Uematsu, Mitsuo

    2002-12-01

    Samples of aerosol, sea fog, and rainwater were collected during a research cruise in the northwestern North Pacific, the Sea of Okhotsk, and the Sea of Japan in the summer of 1998. High concentrations of NO3-, nss-SO42- and NH4+ in aerosol over the Sea of Japan suggest that anthropogenic substances were transported to this region. Although the Sea of Okhotsk was covered with a clean marine air mass, the concentration of nss-SO42- was comparatively high in the aerosol samples. This nss-SO42- is probably of marine biogenic origin. The pH values of fogwater samples were measured to be fogwater collected over the Sea of Japan were higher than those in the other regions, suggesting that the sea fog scavenged anthropogenic substances. The concentration of nss-SO42- in fogwater over the Sea of Okhotsk was equivalent to that over the Sea of Japan, probably because nss-SO42- and SO2 of marine biogenic origin were scavenged by the sea fog over the Sea of Okhotsk. The pH values of rainwater samples ranged from 6.1 to 7.2 during the cruise, and acidification of the rain was not significant. The concentrations of nss-Ca2+ in the rainwater were higher than those of the fogwater. This suggests that the rain-scavenged continental CaCO3 may have existed above the lower marine boundary layer, where sea fog appeared. Comparisons of the composition of aerosol and fogwater indicated that coarse particles, such as sea salts predominantly act as condensation nuclei of sea fog droplets rather than fine particles such as (NH4)2SO4.

  14. The distribution and origin of PAHs over the Asian marginal seas, the Indian, and the Pacific Oceans: Implications for outflows from Asia and Africa

    Science.gov (United States)

    Liu, Junwen; Xu, Yue; Li, Jun; Liu, Di; Tian, Chongguo; Chaemfa, Chakra; Zhang, Gan

    2014-02-01

    Aerosol samples were collected aboard the R/V Dayang Yihao from 8 January to 7 August 2007 to investigate the geographical distribution of polycyclic aromatic hydrocarbons (PAHs) over oceans and to assess their continental origins. The highest concentrations were found over the marginal seas in Asia, especially the East and South China Seas, indicating that China is a top source of emissions into the marine atmosphere in the areas monitored on this cruise. PAH concentrations over the west oceanic region in the South Indian Ocean were noticeably higher than in other areas of the Indian Ocean, most likely because air masses from Africa, the Arabian Sea, and the Bay of Bengal exert a negative impact on those regions through long-range atmospheric transport. The PAH isomer ratio values varied over the oceans that were impacted by continental sources but remained relatively uniform over most of the remote oceans. Using diagnostic ratio analysis, we found PAHs emitted from China were mainly associated with biomass/coal burning. The measurements of levoglucosan were consistent with the results mentioned above. The western part of the South Indian Ocean atmosphere was likely affected by wildfire emissions from Africa, while the northern part was by petroleum combustion, biofuel, and wildfire burning, because the winter monsoon most likely carries aerosol from the Arabian Peninsula and India across the equator. Using the monthly images of fire activity and aerosol optical depth, it can be confirmed biomass burning from Africa can significantly influence the aerosol over the Indian Ocean.

  15. U-Pb Dating and Lu-Hf Isotopes of Detrital Zircons From the Southern Sikhote-Alin Orogenic Belt, Russian Far East: Tectonic Implications for the Early Cretaceous Evolution of the Northwest Pacific Margin

    Science.gov (United States)

    Liu, Kai; Zhang, Jinjiang; Wilde, Simon A.; Liu, Shiran; Guo, Feng; Kasatkin, Sergey A.; Golozoubov, Vladimir V.; Ge, Maohui; Wang, Meng; Wang, Jiamin

    2017-11-01

    The Sikhote-Alin orogenic belt in Russian Far East is comprised of several N-S trending belts, including the Late Jurassic to Early Cretaceous accretionary prisms and turbidite basin which are now separated by thrusts and strike-slip faults. The origin and collage of the belts have been studied for decades. However, the provenance of the belts remains unclear. Six sandstone samples were collected along a 200 km long east-west traverse across the major belts in the southern Sikhote-Alin for U-Pb dating and Lu-Hf isotope analysis to constrain the provenance and evaluate the evolution of the northwest Pacific margin at this time. The result reveals that the sediments from the main Samarka belt was mainly from the adjacent Bureya-Jiamusi-Khanka Block (BJKB); the eastern Samarka belt and the Zhuravlevka turbidite basin were supplied by detritus from both the North China Craton (NCC) and the BJKB; the Taukha belt was mainly fed by sediments from the NCC; whereas the data from the Sergeevka nappes are insufficient to resolve their provenance. In the Late Jurassic to Early Cretaceous, collision and subduction was important in the initial collage of most belts in Sikhote-Alin. However, merely E-W trending collage cannot explain the increasing importance of the NCC provenance from west to east. It is proposed that the main Samarka belt was located adjacent to the BJKB when deposited, whereas the other belts were farther south to accept the materials from the NCC. Sinistral strike-slip faulting transported the eastern belts northward after their initial collage by thrusting.

  16. Marginal Matter

    Science.gov (United States)

    van Hecke, Martin

    2013-03-01

    All around us, things are falling apart. The foam on our cappuccinos appears solid, but gentle stirring irreversibly changes its shape. Skin, a biological fiber network, is firm when you pinch it, but soft under light touch. Sand mimics a solid when we walk on the beach but a liquid when we pour it out of our shoes. Crucially, a marginal point separates the rigid or jammed state from the mechanical vacuum (freely flowing) state - at their marginal points, soft materials are neither solid nor liquid. Here I will show how the marginal point gives birth to a third sector of soft matter physics: intrinsically nonlinear mechanics. I will illustrate this with shock waves in weakly compressed granular media, the nonlinear rheology of foams, and the nonlinear mechanics of weakly connected elastic networks.

  17. Evolution of the Northeastern Arabian Plate Margin and Shelf: Hydrocarbon Habitat and Conceptual Future Potential L'évolution géologique de la plate-forme arabe et de sa marge : répartition des hydrocarbures et concepts pour son potentiel futur

    Directory of Open Access Journals (Sweden)

    Beydoun Z. R.

    2006-11-01

    Full Text Available About 98% of the huge recoverable hydrocarbon reserves of the Arabian Plate are concentrated in the Northeastern Margin Shelf extending from NW Iraq through the Gulf to Central Oman. The plate tectonic evolution of this region is reviewed as background for its enormous hydrocarbon productivity. This is intimately linked to a near-continuous passive margin history and gentle subsidence of an extraordinarily wide epeiric shelf, which allowed repeated regional development of source rocks in large intra-shelf basins frequently in optimal juxtapositional relationships with good regional reservoirs and seals; these events are discussed. Although currently reported reserve figures relate to Mesozoic and Tertiary reservoirs, it is concluded that several pre-Mesozoic regional sources have generated enormous volumes of hydrocarbons, the bulk of which still await discovery in up-dip Paleozoic reservoirs, and that future ultimate recoverable reserves could conceivably double. Près de 98 % des énormes réserves récupérables d'hydrocarbures de la plaque arabique sont concentrés dans la marge nord-est qui s'étend du nord-ouest de l'Irak au centre d'Oman, à travers le Golfe. L'auteur passe en revue l'évolution tectonique de cette région, origine de son énorme productivité pétrolière. La passivité presque continue de cette marge, combinée à l'affaissement progressif d'un plateau épicontinental particulièrement large, a permis le développement local répété de roches mères, au sein du plateau, dans de vastes bassins bénéficiant souvent d'une juxtaposition optimale avec les roches réservoir et roche-couvertures. L'article étudie ces évènements. Si les réserves actuellement prises en compte sont essentiellement d'origine mésozoïque et tertiaire, l'auteur conclut que de nombreuses sources régionales pré-mésozoïques ont généré d'énormes volumes d'hydrocarbures, dont la majeur partie reste à découvrir dans des réservoirs pal

  18. [Sinaloa: the geography of marginalization].

    Science.gov (United States)

    Aguayo Hernandez, J R

    1993-01-01

    Sinaloa's State Population Program for 1993-98 contains the objective of promoting integration of demographic criteria into the planning process. The action program calls for establishing indicators of economic and social inequality so that conditions of poverty and margination can be identified. To further these goals, the State Population Council used data from the National Population Council project on regional inequality and municipal margination in Mexico to analyze margination at the state level. Nine indicators of educational status, housing conditions, spatial distribution, and income provide information that allows the definition of municipios and regions that should receive priority in economic and social development programs. The index of municipal margination (IMM) is a statistical summary of the nine indicators, which are based on information in the 1990 census. As of March 1990, 9.9% of Sinaloa's population over age 15 was illiterate and 37.4% had incomplete primary education. 91.0% had electricity, but 18.7% lacked indoor toilet facilities and 19.4% had no piped water. 23.7% of houses had dirt floors. 60% of households were crowded, defined as having more than two persons per bedroom. 43.5% of the state population lived in localities with fewer than 5000 inhabitants, where service delivery is difficult and costly. 55.6% of the economically active population was judged to earn less than the amount needed to satisfy essential needs. All except one municipio bordering the Pacific ocean had low or very low indicators of margination, while all those in the sierra had a medium or high degree of margination. Sinaloa's statewide IMM was eighteenth among Mexico's 32 federal entities, with Chiapas showing the highest degree of margination and the Federal District the lowest.

  19. Assessment of Biomass Resources from Marginal Lands in APEC Economies

    Energy Technology Data Exchange (ETDEWEB)

    Milbrandt, A.; Overend, R. P.

    2009-08-01

    The goal of this study is to examine the marginal lands in Asia-Pacific Economic Cooperation (APEC) economies and evaluate their biomass productivity potential. Twelve categories of marginal lands are identified using the Global Agro-Ecological Zones system of the United Nations Food and Agriculture Organization.

  20. Subsidence and Extension Rates of Laguna Salada Basin, Northeastern Baja California, Mexico

    Science.gov (United States)

    Contreras, J.; Martin-Barajas, A.; Herguera, J. C.

    2002-12-01

    Laguna Salada basin in northeastern Baja California, Mexico, is an active half-graben product of the trans-tensional tectonics of the Gulf of California. It lies at the boundary between the North America and Pacific plates, 15 km west of the Cerro Prieto-Imperial fault system. We present the results of a time series analysis of the uppermost 980 m of a gamma ray log from the geothermal exploratory well ELS1 drilled in the proximity of the Laguna Salada fault, which bounds the basin on its eastern margin. Our analysis indicates its stratigraphy is cyclical and that the spectrum of the gamma ray log is similar to the spectrum of δ18O Pleistocene variations, which strongly suggest an orbital origin. Based on this, we establish a correlation between the gamma ray log and δ18O stages to constrain ages of sediments with an estimated uncertainty of ~10 kyr. We found that sedimentation rates at ELS1 site have remained constant during the last 780 kyr. The sedimentation rate at the ELS1 site is 1.6 mm/yr. This value is extrapolated to obtain the vertical and perpendicular to strike slip rates of Laguna Salada fault. It was found that the vertical slip component is 4.22 mm/yr and the perpendicular to strike slip component (E-W direction) is 1.55 mm/yr.

  1. Occurrence of Pacific Golden Plovers in The Netherlands; Historical perspectives from the "Wilsternetters"

    NARCIS (Netherlands)

    Jukema, J; Piersma, T

    The present wintering range of the Pacific Golden Plover (Pluvialis fulva) includes the northeastern Lip of Africa, southern Asia, to Australia and New Zealand and much of the Pacific Ocean. We summarize evidence from the oral history of "Wilsternetters" (artisanal hunters using air ancient,

  2. Occurrence of Pacific Golden Plovers in The Netherlands; Historical Perspectives from the “Wilsternetters”

    NARCIS (Netherlands)

    Jukema, Joop; Piersma, Theunis

    2002-01-01

    The present wintering range of the Pacific Golden Plover (Pluvialis fulva) includes the northeastern tip of Africa, southern Asia, to Australia and New Zealand and much of the Pacific Ocean. We summarize evidence from the oral history of “wilsternetters” (artisanal hunters using an ancient,

  3. Possible Role of Hadley Circulation Strengthening in Interdecadal Intensification of Snowfalls Over Northeastern China Under Climate Change

    Science.gov (United States)

    Zhou, Botao; Wang, Zunya; Shi, Ying

    2017-11-01

    This article revealed that strengthening of winter Hadley circulation in the context of climate change may partially contribute to interdecadal increasing of snowfall intensity over northeastern China in recent decades. This hypothesis is well supported by the process-based linkage between Hadley circulation and atmospheric circulations over the Asian-Pacific region on the interdecadal time scale. The strengthening of winter Hadley circulation corresponds to a weakening of the Siberian high, an eastward shifting of the Aleutian low, a reduction of the East Asian trough, and anomalous southwesterly prevailing over northeastern China. These atmospheric situations weaken the East Asian winter monsoon and lead to an increase of air temperature over northeastern China. Increased local evaporation due to the increase of air temperature, concurrent with more water vapor transported from the Pacific Ocean, can significantly enhance atmospheric water vapor content in the target region. Meanwhile, the ascending of airflows is also strengthened over northeastern China. All of these provide favorable interdecadal backgrounds for the occurrence of intense snowfalls, and thus, snowfall intensity is intensified over northeastern China after the 1980s. Further analysis suggests that the circum-Pacific-like teleconnection pattern may play an important role in connecting Hadley circulation strengthening signal and atmospheric circulation anomalies favoring interdecadal intensification of snowfalls over northeastern China.

  4. Analysis of subsidence in northeastern Venezuela as a discriminator of tectonic models for northern South America

    Science.gov (United States)

    Erikson, Johan P.; Pindell, James L.

    1993-10-01

    Subsidence analysis of northeastern Venezuela's exposed, parautochthonous Lower Cretaceous-Miocene sedimentary section reveals an Atlantic-type passive-margin subsidence history for the entire Cretaceous-middle Eocene interval; Oligocene-Miocene subsidence was rapid and great and was caused by foredeep formation and emplacement of the fold-and-thrust belt that now exposes the passive-margin sedimentary section. Our analyses support tectonic models of South America's northern margin which propose Cenozoic eastward migration of a foredeep along northern South America's late Mesozoic passive margin. The calculated subsidence is inconsistent with tectonic models that propose middle or Late Cretaceous subduction or obduction.

  5. Cenozoic mountain building on the northeastern Tibetan Plateau

    Science.gov (United States)

    Lease, Richard O.

    2014-01-01

    Northeastern Tibetan Plateau growth illuminates the kinematics, geodynamics, and climatic consequences of large-scale orogenesis, yet only recently have data become available to outline the spatiotemporal pattern and rates of this growth. I review the tectonic history of range growth across the plateau margin north of the Kunlun fault (35°–40°N) and east of the Qaidam basin (98°–107°E), synthesizing records from fault-bounded mountain ranges and adjacent sedimentary basins. Deformation began in Eocene time shortly after India-Asia collision, but the northeastern orogen boundary has largely remained stationary since this time. Widespread middle Miocene–Holocene range growth is portrayed by accelerated deformation, uplift, erosion, and deposition across northeastern Tibet. The extent of deformation, however, only expanded ~150 km outward to the north and east and ~150 km laterally to the west. A middle Miocene reorganization of deformation characterized by shortening at various orientations heralds the onset of the modern kinematic regime where shortening is coupled to strike slip. This regime is responsible for the majority of Cenozoic crustal shortening and thickening and the development of the northeastern Tibetan Plateau.

  6. Reconstructing marginality: a new model of cultural diversity in nursing.

    Science.gov (United States)

    Southwick, Margaret; Polaschek, Nick

    2014-05-01

    This article presents a new model of cultural diversity in nursing that critically reconstructs the concept of marginality that underpins other models. Rather than viewing the marginal as "other," marginality is redefined as the space in between the dominant cultural reality and the cultural realities of minority groups located within a society. Members of a minority cultural group who become skilled in the difficult process of negotiating this in-between space open the possibility of transformation within nursing education and practice. This model has been applied in a study of the experience of nursing students of Pacific ethnicity in New Zealand. Subsequently, an undergraduate Pacific nursing program was developed, with greatly increased success rates in registration of Pacific nurses. This model of cultural diversity can also be used to understand nursing practice involving people from minority cultures or other socially excluded categories. Copyright 2014, SLACK Incorporated.

  7. Boundary scavenging in the Pacific Ocean

    International Nuclear Information System (INIS)

    Anderson, R.F.; Lao, Y.; Broecker, W.S.; Trumbore, S.E.; Hofmann, H.J.; Wolfli, W.

    1990-01-01

    Concentrations of U, Th, 231 Pa and 10 Be were measured in Holocene sediments from two cores collected off the west coast of South America, two cores from the East Pacific Rise, two from the equatorial Pacific and one from the south Pacific central gyre. Our results, together with data from 5 cores reported in the literature, show that boundary scavenging plays a major role in the removal of 10 Be from the Pacific Ocean. Deposition rates of 10 Be at three margin sites are more than an order of magnitude greater than at sites of red clay accumulation in the deep central Pacific. Deposition of 231 Pa is 4 to 5-fold greater at the margin sites. The residence time of 10 Be with respect to chemical scavenging, defined as its inventory in the water column divided by its rate of removal to the sediments, varies regionally from >1000 years at the red-clay sites in the deep central Pacific to ∝100 years at the margin sites. Different factors control boundary scavenging of Pa and Be. For example, scavenging of 231 Pa is enhanced by metal-oxide coatings of particles, whereas this seems to have little influence on the scavenging of 10 Be. (orig.)

  8. Tsunami scattering provinces in the Pacific Ocean

    Science.gov (United States)

    Mofjeld, H. O.; Titov, V. V.; González, F. I.; Newman, J. C.

    We use a scattering index to identify the regions in the Pacific Ocean where topographic features scatter significant tsunami energy. Based on linear wave theory, the index is computed from the Smith/Sandwell topography. Consistent with numerical simulations, it shows that there is a narrow band of strong scatterers running across the ocean from the northwest (Emperor Seamount Chain) to the southeast (Easter Island Fracture Zone). The eastern Pacific is nearly devoid of scatterers, except for this band and isolated features along the eastern margin. To the west of the band lies a region with moderate scattering; the strongest scattering occurs in the southwestern Pacific. The Pacific is rimmed by island arcs and shallow continental shelves that also trap and scatter tsunamis. These results show that numerical models of trans-Pacific tsunamis must resolve the effects of the small-scale topography in order to accurately simulate their wave patterns and amplitudes.

  9. Physiology and the mariculture of some northeastern Pacific bivalve molluscs

    National Research Council Canada - National Science Library

    Bernard, F. R

    1983-01-01

    Equations describing the effects of water temperature, salinity, oxygen, and food availability on ventilation and oxygen consumption rates of nine species of bivalve molluscs from the Oregonian Province are given...

  10. Crustal shear wave velocity structure in the northeastern Tibet based on the Neighbourhood algorithm inversion of receiver functions

    Science.gov (United States)

    Wu, Zhenbo; Xu, Tao; Liang, Chuntao; Wu, Chenglong; Liu, Zhiqiang

    2018-03-01

    The northeastern (NE) Tibet records and represents the far-field deformation response of the collision between the Indian and Eurasian plates in the Cenozoic time. Over the past two decades, studies have revealed the existence of thickened crust in the NE Tibet, but the thickening mechanism is still in debate. We deployed a passive-source seismic profile with 22 temporary broad-band seismic stations in the NE Tibet to investigate the crustal shear wave velocity structure in this region. We selected 288 teleseismic events located in the west Pacific subduction zone near Japan with similar ray path to calculate P-wave receiver functions. Neighbourhood algorithm method is applied to invert the shear wave velocity beneath stations. The inversion result shows a low-velocity zone (LVZ) is roughly confined to the Songpan-Ganzi block and Kunlun mountains and extends to the southern margin of Gonghe basin. Considering the low P-wave velocity revealed by the wide-angle reflection-refraction seismic experiment and high ratio of Vp/Vs based on H-κ grid searching of the receiver functions in this profile, LVZ may be attributed to partial melting induced by temperature change. This observation appears to be consistent with the crustal ductile deformation in this region derived from other geophysical investigations.

  11. Plate boundary deformation of the Pacific plate. Two case studies. (1) Crustal structure of the northwestern Vizcaino block and Gorda escarpment, offshore northern California, and implications for postsubduction deformation of a paleoaccretionary margin. (2) A focused look at the Alpine fault, New Zealand: Seismicity, focal mechanisms and stress observations

    Science.gov (United States)

    Leitner, Beate

    Two examples of Pacific rim plate boundary deformation are presented. In the first part of the thesis crustal models are derived for the northwestern part of the Vizcaino block in California using marine seismic and gravity data collected by the Mendocino Triple Junction Seismic Experiment. A northwest-southeast trending kink in the Moho is imaged and interpreted to have formed under compression by reactivation of preexisting thrust faults in the paleoaccretionary prism at the seaward margin of the Vizcaino block. The study suggests that the deformation resulted from mainly north-south compression between the Pacific-Juan de Fuca plates across the Mendocino transform fault and predates late Pliocene Pacific-North America plate convergence. In the second part, 195 earthquakes recorded during the duration of the Southern Alps Passive Seismic Experiment (SAPSE) are analysed. Precise earthquake locations and focal mechanisms provide unprecedented detail of the seismotectonics in the central South Island. The short term (6 month) SAPSE seismicity is compared with long term (8 years) seismicity recorded by the New Zealand National Seismic network and the Lake Pukaki network. The seismicity rate of the Alpine fault is low, but comparable to locked sections of the San Andreas fault, with large earthquakes expected. Changes of the depth of the seismogenic zone, generally uniform at about 10--12 km, occur only localised over distances smaller than 30 km, suggesting that thermal perturbations must be of similar scale. This implies that the thermal effects of the uplift of the Southern Alps do not change the seismogenic depth significantly and are not in accordance with most of the present thermal models. Both the Hope and Porters Pass fault zones are seismically active and deformation is accommodated near the fault zones and in the adjacent crust. North of Mt Cook, a triangular shaped region along the Alpine fault is characterised by absence of earthquakes. We interpret this

  12. Zooplankton data from plankton net in the Northwest Pacific Ocean by the Japan Hydrography Association from 22 April 1952 to 06 January 1990 (NODC Accession 0000273)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The sea area of the western North Pacific Ocean off the northeastern part of Japan is called Tohoku Sea Area. The hydrography in the sea area is complicated by...

  13. Late Mesozoic and Cenozoic thermotectonic history of the Mexican Pacific margin (18 to 25°N): new insight from apatite and zircon fission-track analysis of coastal and offshore plutonic rocks

    Science.gov (United States)

    Calmus, Thierry; Poupeau, Gérard; Bourgois, Jacques; Michaud, François; Mercier de Lépinay, Bernard; Labrin, Erika; Azdimousa, Ali

    1999-06-01

    Apatite and zircon fission-track dating was used to constrain cooling histories on granitic samples taken from the offshore Acapulco trench batholith and onshore Manzanillo and Puerto Vallarta batholiths located along the southwestern active margin of Mexico, and from the La Paz batholith of southern Baja California. The apatite data indicate that many of the samples in the Manzanillo, Acapulco trench batholiths cooled rapidly below 60°C shortly after emplacement between 70 and 55 Ma. The La Paz batholith and the sample NM-20-08 of the Acapulco trench batholith experienced an older and slower cooling across the apatite partial annealing zone. The zircon fission-track ages obtained from two samples of the Puerto Vallarta batholith indicate a rapid cooling from 250 to 110°C between 54 and 50 Ma. This non-coeval cooling of batholiths at two different depths is probably due to uplift and erosion associated with the Laramide event in southwestern Mexico. The three samples from the Puerto Vallarta batholith suggest a younger evolution across low temperatures with two flat stages located near the base of the apatite partial annealing zone and above it. The first flat stage suggests that the denudation or rock uplift rate was reduced at a depth corresponding to the base of the apatite partial annealing zone. The younger single apatite ages of the Puerto Vallarta batholith, and the last common cooling of the other batholiths indicate the mild thermal influences of both the Plio-Pleistocene Trans-Mexican Volcanic Belt and the opening of the Gulf of California.

  14. The Ebro margin study, northwestern Mediterranean Sea - an introduction

    Science.gov (United States)

    Maldonado, A.; Hans, Nelson C.

    1990-01-01

    The Ebro continental margin from the coast to the deep sea off northeastern Spain was selected for a multidisciplinary project because of the abundant Ebro River sediment supply, Pliocene and Quaternary progradation, and margin development in a restricted basin where a variety of controlling factors could be evaluated. The nature of this young passive margin for the last 5 m.y. was investigated with particular emphasis on marine circulation, sediment dynamics, sediment geochemistry, depositional facies, seismic stratigraphy, geotechnical properties, geological hazards and human influences. These studies show the importance of marine circulation, variation in sediment supply, sea-level oscillation and tectonic setting for the understanding of modern and ancient margin depositional processes and growth patterns. ?? 1990.

  15. MISR Images Northeastern Botswana

    Science.gov (United States)

    2000-01-01

    MISR images of the Ntwetwe and Sua Pans in northeastern Botswana, acquired on August 18, 2000 (Terra orbit 3553). The left image is a color view from the vertical-viewing (nadir) camera. On the right is a composite of red band imagery in which the 45-degree aft camera data are displayed in blue, 45-degree forward as green, and vertical as red. This combination causes wet areas to appear blue because of the glint-like reflection from water and damp surfaces. Clouds are visible in the upper left corner and right center of each image. The clouds look peculiar in the multi-angle view because geometric parallax resulting from their elevation above the surface causes a misregistration of the individual images making up the composite. This stereoscopic effect provides a way of distinguishing clouds from bright surfaces.The images are approximately 250 kilometers across. Ntwetwe and Sua pans are closed interior basins that catch rainwater and surface runoff during the wet season. Seasonal lakes form that may reach several meters in depth. During the dry season the collected waters rapidly evaporate leaving behind dissolved salts that coat the surface and turn it bright ('sua' means salt). The mining town of Sowa is located where the Sua Spit (a finger of grassland extending into the pan) attaches to the shore. Sowa represents headquarters for a JPL contingent carrying out MISR field experiments using the evaporite surface and the grasslands as targets and for Botswana scientists studying migration of groundwaters beneath the pans and surrounding areas. These efforts support the Southern Africa Regional Science Initiative (SAFARI-2000), which is now underway.MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.For more information: http://www-misr.jpl.nasa.gov

  16. Marginalization of the Youth

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2009-01-01

    The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization.......The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization....

  17. Sedimentary structure and tectonic setting of the abyssal basins adjoining the southeast part of the Ontong Java Plateau, western Pacific Ocean

    Science.gov (United States)

    Shimizu, S.; Masato, N.; Miura, S.; Suetsugu, D.

    2017-12-01

    Ontong Java Plateau(OJP) in the western Pacific Ocean is one of the largest oceanic plateau in the world. Radioactive ages of drilling samples indicate that the most part of the OJP was emplaced about 122 Ma (Mahoney et al., 1993). Taylor (2006) proposed that the OJP formed as a single large volcanic province together with the Manihiki and Hikurangi plateaus. OJP is surrounding by East Mariana, Pigafetta, Nauru, Ellice, Stewart, and Lyra basins. The East Mariana and Pigafetta basins were formed at the Pacific-Izanagi ridge and the Nauru basin was formed at Pacific-Phoenix ridges (Nakanishi et al., 1992). The tectonic history of the Ellice, Stewart, and Lyra basins is still unknown because of lack of magnetic anomaly lineations. Tectonic setting during the OJP formation is thus a matter of controversy. To expose the tectonic setting of the Ellice, Stewart, and Lyra basins, we conducted the Multi-Channel Seismic (MCS) survey in the basins during the research cruise by R/V Mirai of JAMSTEC in 2014. We present our preliminary results of the MCS survey in the Stewart basin(SB) and Ellice Basin(EB). After the regular data processing, we compared the seismic facies of MCS profile with DSDP Site 288 and ODP Site 1184 to assign ages to seismic reflectors. Our processing exposed several remarkable structures in the basins. The graben structures deformed only the igneous basement in the northwestern and northeastern and southwestern margins of the SB. This suggests the graben structures were formed before sedimentary layer deposited. Taylor (2006) proposed that the basin was formed by the NW-SE rifting during the separation of OJP and Manihiki Plateau around 120 Ma. Neal (1997) proposed that the NE-SW rifting formed the basin around 80 Ma. Our study supports the rifting model proposed by Neal et al. (1997) because the displacement of graben in northeastern and southwestern margins of the SB is larger than that in northwestern of the SB. We found several igneous diapirs in the

  18. Matthew and marginality

    Directory of Open Access Journals (Sweden)

    Denis C. Duling

    1995-12-01

    Full Text Available This article explores marginality theory as it was first proposed in  the social sciences, that is related to persons caught between two competing cultures (Park; Stonequist, and, then, as it was developed in sociology as related to the poor (Germani and in anthropology as it was related to involuntary marginality and voluntary marginality (Victor Turner. It then examines a (normative scheme' in antiquity that creates involuntary marginality at the macrosocial level, namely, Lenski's social stratification model in an agrarian society, and indicates how Matthean language might fit with a sample inventory  of socioreligious roles. Next, it examines some (normative schemes' in  antiquity for voluntary margi-nality at the microsocial level, namely, groups, and examines how the Matthean gospel would fit based on indications of factions and leaders. The article ,shows that the author of the Gospel of Matthew has an ideology of (voluntary marginality', but his gospel includes some hope for (involuntary  marginals' in  the  real world, though it is somewhat tempered. It also suggests that the writer of the Gospel is a (marginal man', especially in the sense defined by the early theorists (Park; Stone-quist.

  19. Regional geologic framework off northeastern United States

    International Nuclear Information System (INIS)

    Schlee, J.; Behrendt, J.C.; Grow, J.A.; Robb, J.M.; Mattick, R.E.; Taylor, P.T.; Lawson, B.J.

    1976-01-01

    Six multichannel seismic-reflection profiles taken across the Atlantic continental margin off the northeastern United States show an excess of 14 km of presumed Mesozoic and younger sedimentary rocks in the Baltimore Canyon trough and 8 km in the Georges Bank basin. Beneath the continental rise, the sedimentary prism thickness exceeds 7 km south of New Jersey and Maryland, and it is 4.5 km thick south of Georges Bank Stratigraphically, the continental slope--outer edge of the continental shelf is a transition zone of high-velocity sedimentary rock, probably carbonate, that covers deeply subsidized basement. The spatial separation of magnetic and gravity anomalies on line 2 (New Jersey) suggests that in the Baltimore Canyon region the magnetic-slope anomaly is due to edge effects and that the previously reported free-air and isostatic gravity anomalies over the outer shelf may be due in part to a lateral increase in sediment density (velocity) near the shelf edge. The East Coast magnetic anomaly and the free-air gravity high both coincide over the outer shelf edge on line 1 (Georges Bank) but are offset by 20 km from the ridge on the reflection profile

  20. The Cadiz margin study off Spain: An introduction

    Science.gov (United States)

    Nelson, C.H.; Maldonado, A.

    1999-01-01

    The Cadiz continental margin of the northeastern Gulf of Cadiz off Spain was selected for a multidisciplinary project because of the interplay of complex tectonic history between the Iberian and African plates, sediment supply from multiple sources, and unique Mediterranean Gateway inflow and outflow currents. The nature of this complex margin, particularly during the last 5 million years, was investigated with emphasis on tectonic history, stratigraphic sequences, marine circulation, contourite depositional facies, geotechnical properties, geologic hazards, and human influences such as dispersal of river contaminants. This study provides an integrated view of the tectonic, sediment supply and oceanographic factors that control depositional processes and growth patterns of the Cadiz and similar modem and ancient continental margins.

  1. Refining margins: recent trends

    International Nuclear Information System (INIS)

    Baudoin, C.; Favennec, J.P.

    1999-01-01

    Despite a business environment that was globally mediocre due primarily to the Asian crisis and to a mild winter in the northern hemisphere, the signs of improvement noted in the refining activity in 1996 were borne out in 1997. But the situation is not yet satisfactory in this sector: the low return on invested capital and the financing of environmental protection expenditure are giving cause for concern. In 1998, the drop in crude oil prices and the concomitant fall in petroleum product prices was ultimately rather favorable to margins. Two elements tended to put a damper on this relative optimism. First of all, margins continue to be extremely volatile and, secondly, the worsening of the economic and financial crisis observed during the summer made for a sharp decline in margins in all geographic regions, especially Asia. Since the beginning of 1999, refining margins are weak and utilization rates of refining capacities have decreased. (authors)

  2. "We call ourselves marginalized"

    DEFF Research Database (Denmark)

    Jørgensen, Nanna Jordt

    2014-01-01

    In recent decades, indigenous knowledge has been added to the environmental education agenda in an attempt to address the marginalization of non-western perspectives. While these efforts are necessary, the debate is often framed in terms of a discourse of victimization that overlooks the agency o...... argue that researchers not only need to pay attention to how certain voices are marginalized in Environmental Education research and practice, but also to how learners as agents respond to, use and negotiate the marginalization of their perspectives.......In recent decades, indigenous knowledge has been added to the environmental education agenda in an attempt to address the marginalization of non-western perspectives. While these efforts are necessary, the debate is often framed in terms of a discourse of victimization that overlooks the agency...

  3. Indian Ocean margins

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    The most important biogeochemical transformations and boundary exchanges in the Indian Ocean seem to occur in the northern region, where the processes originating at the land-ocean boundary extend far beyond the continental margins. Exchanges across...

  4. Temperature, salinity, dissolved oxygen, fluorometer, and other data collected with CTD casts during six ECOHAB cruises in the Northeast Pacific and Puget Sound, 6/2/2003 - 10/4/2006 (NODC Accession 0049079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is the final processed data for the following cruises in the northeastern Pacific Ocean, Strait of Juan De Fuca, and Puget Sound from 20030602 to 20061004: 1....

  5. Areaplanning in marginal areas

    OpenAIRE

    Janneau, Thibaut; Arborg, Pernille; Sandberg, Rina

    2007-01-01

    This project is also a comparative analysis between two cases: Lolland Kommune and Venise Verte, having both a marginal characteristic. The analyze of these two marginal areas makes us able to found out some dilemmas showing the crucial issues of planners between economic development, social equity, cultural evolution and finally environmental enhancer. We also tried to see the different views of nature between two paradigms: widleness of nature and cultural landscapes as well as graduate dif...

  6. Asia-Pacific energy database

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    Statistical data is presented in graphic and tabular form on the petroleum market in Asia and Pacific nations. Seven major categories are reported: (1) primary energy production and consumption; (2) historical petroleum product demand and forecasts; (3) crude oil production and exports; (4) import dependence; (5) crude and product pricing assumptions; (6) market share of refined products by suppliers in selected countries; and (7) refining margins. Petroleum demand and forecasts and crude oil production and exports are reported by country. Historical data are presented from 1970 through 1996, and forecasts are made through 2010.

  7. Pickering seismic safety margin

    International Nuclear Information System (INIS)

    Ghobarah, A.; Heidebrecht, A.C.; Tso, W.K.

    1992-06-01

    A study was conducted to recommend a methodology for the seismic safety margin review of existing Canadian CANDU nuclear generating stations such as Pickering A. The purpose of the seismic safety margin review is to determine whether the nuclear plant has sufficient seismic safety margin over its design basis to assure plant safety. In this review process, it is possible to identify the weak links which might limit the seismic performance of critical structures, systems and components. The proposed methodology is a modification the EPRI (Electric Power Research Institute) approach. The methodology includes: the characterization of the site margin earthquake, the definition of the performance criteria for the elements of a success path, and the determination of the seismic withstand capacity. It is proposed that the margin earthquake be established on the basis of using historical records and the regional seismo-tectonic and site specific evaluations. The ability of the components and systems to withstand the margin earthquake is determined by database comparisons, inspection, analysis or testing. An implementation plan for the application of the methodology to the Pickering A NGS is prepared

  8. SOCIAL MARGINALIZATION AND HEALTH

    Directory of Open Access Journals (Sweden)

    Marjana Bogdanović

    2007-04-01

    Full Text Available The 20th century was characterized by special improvement in health. The aim of WHO’s policy EQUITY IN HEALTH is to enable equal accessibility and equal high quality of health care for all citizens. More or less some social groups have stayed out of many social systems even out of health care system in the condition of social marginalization. Phenomenon of social marginalization is characterized by dynamics. Marginalized persons have lack of control over their life and available resources. Social marginalization stands for a stroke on health and makes the health status worse. Low socio-economic level dramatically influences people’s health status, therefore, poverty and illness work together. Characteristic marginalized groups are: Roma people, people with AIDS, prisoners, persons with development disorders, persons with mental health disorders, refugees, homosexual people, delinquents, prostitutes, drug consumers, homeless…There is a mutual responsibility of community and marginalized individuals in trying to resolve the problem. Health and other problems could be solved only by multisector approach to well-designed programs.

  9. Tertiary evolution of the northeastern Venezuela offshore

    Science.gov (United States)

    Ysaccis B., Raul

    1998-12-01

    On the northeastern offshore Venezuela, the pre-Tertiary basement consists of a deeply subducted accretionary complex of a Cretaceous island arc system that formed far to the west of its present location. The internal structure of this basement consists of metamorphic nappes that involve passive margin sequences, as well as oceanic (ophiolitic) elements. The Tertiary evolution of the northeastern Venezuela offshore is dominated by Paleogene (Middle Eocene-Oligocene) extension and Neogene transtension, interrupted by Oligocene to Middle Miocene inversions. The Paleogene extension is mainly an arc-normal extension associated with a retreating subduction boundary. It is limited to the La Tortuga and the La Blanquilla Basins and the southeastern Margarita and Caracolito subbasins. All of these basins are farther north of and not directly tied to the El Pilar fault system. On a reconstruction, these Paleogene extensional systems were located to the north of the present day Maracaibo Basin. By early Miocene the leading edge of the now overall transpressional system had migrated to a position to the north of the Ensenada de Barcelona. This relative to South America eastward migration is responsible for the Margarita strike-slip fault and the major inversions that began during the Oligocene and lasted into the Middle Miocene. The Bocono-El Pilar-Casanay-Warm Springs and the La Tortuga-Coche-North Coast fault systems are exclusively Neogene with major transtension occurring during the Late Miocene to Recent and act independently from the earlier Paleogene extensional system. They are responsible for the large Neogene transtensional basins of the area: the Cariaco trough, the Northern Tuy-Cariaco and the Paria sub-basins, and the Gulf of Paria Basin. This latest phase is characterized by strain-partitioning into strike slip faults, a transtensional northern domain and a transpressional southern domain that is responsible for the decollement tectonics and/or inversions of the

  10. Boninites: Characteristics and tectonic constraints, northeastern Appalachians

    Science.gov (United States)

    Kim, J.; Jacobi, R.D.

    2002-01-01

    Boninites are high Mg andesites that are thought to form in suprasubduction zone tectonic environments as primary melts from refractory mantle. Boninites provide a potential constraint on tectonic models for ancient terranes that contain boninites because the only unequivocal tectonic setting in which "modern" boninites have been recognized is a fore-arc setting. Tectonic models for "modern" boninite genesis include subduction initiation ("infant arc"), fore-arc spreading, and the forearc side of intra-arc rifting (spreading). These models can be differentiated by the relative age of the boninites and to a lesser degree, geochemistry. The distinctive geochemistry of boninites promotes their recognition in ancient terranes. As detailed in this report, several mafic terranes in the northeastern Appalachians contain boninites; these terranes were situated on both sides of Iapetus. The characteristics of these boninites can be used to constrain tectonic models of the evolution of the northeastern Appalachians. On the Laurentian side of Iapetus, "infant arc" boninites were not produced ubiquitously during the Cambrian subduction initiation, unless sampling problems or minimum age dates obscure a more widespread boninite "infant arc". The Cambrian subduction initiation on the Laurentian side was probably characterized by both "infant arc" boninitic arc construction (perhaps the >496 Ma Hawley Formation and the >488 Ma Betts Cove Ophiolite) and "normal" arc construction (Mt. Orford). This duality is consistent with the suggestion that the pre-collisional geometry of the Laurentian margin was complex. The Bay of Islands Complex and Thetford Mines ophiolite boninites are likely associated with forearc/intra-arc spreading during the protracted evolution of the Cambrian arc system. The relatively young boninites in the Bronson Hill Arc suggest that the Taconic continuous eastward subduction tectonic model is less tenable than other models. On the Gondwana side of Iapetus, the

  11. A new caruncle-bearing Limnonectes (Anura: Dicroglossidae) from northeastern Thailand.

    Science.gov (United States)

    Aowphol, Anchalee; Rujirawan, Attapol; Taksintum, Wut; Chuaynkern, Yodchaiy; Stuart, Bryan L

    2015-05-08

    A new species of the dicroglossid frog genus Limnonectes is described from Ubon Ratchathani Province, northeastern Thailand. Limnonectes lauhachindai sp. nov. differs from its congeners by having males with a low-profiled, U-shaped caruncle with free posterior margin that completely occupies, but does not extend beyond, the interobital region. The new species is most closely related to L. gyldenstolpei and L. dabanus. Its description brings the total number of caruncle-bearing species of Limnonectes to five.

  12. Marginal kidney donor

    Directory of Open Access Journals (Sweden)

    Ganesh Gopalakrishnan

    2007-01-01

    Full Text Available Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.

  13. Análisis estratigráfico secuencial de las formaciones Anacleto y Allen (Cretácico Tardío en el borde nororiental de Cuenca Neuquina, Argentina Sequential stratigraphic analysis of the Anacleto and Allen formations (Late Cretaceous in the northeastern margin of the Neuquina Basin, Argentina

    Directory of Open Access Journals (Sweden)

    Paula Armas

    2011-01-01

    Full Text Available En las provincias de Neuquén y Río Negro a partir de un estudio sedimentológico de detalle se realizó un análisis estratigráfico secuencial de los depósitos del Cretácico Superior de la Formación Anacleto y miembro inferior de la Formación Alien para el borde nororiental de Cuenca Neuquina. La asociación de las litofacies permitió interpretar elementos arquitecturales de origen fluvial y elementos con influencia de mareas. Tres sistemas fluviales (sistema entrelazado, sistema anastomosado y sistema meándrico, un sistema estuárico proximal y uno medio fueron identificados para La Formación Anacleto. Para el miembro basal de la Formación Alien, se definió un sistema estuárico distal o boca de estuario. En el análisis de estratigrafía secuencial se identificó una secuencia constituida por: un cortejo de baja acomodación, en ambiente continental limitado por una superficie de inundación fluvial (discontinuidad I y la discontinuidad II; y un cortejo de alta acomodación y su equivalente cortejo transgresivo en ambiente marino, incluyendo este último las discontinuidades III, IV y V.Based on a detailed sedimentological study we carried out a sequential stratigraphic analysis of the Upper Cretaceous deposits of the Anacleto Formation and lower member of the Alien Formation in the north-eastern border of the Neuquina Basin. The lithofacies association allowed interpre-ting architectural elements of fluvial origin and tide influenced elements. Three fluvial systems (a braided system, an anastomosed one, and a high sinuosity one, a proximal and a middle estuarine system were recognized for the Anacleto Formation. A distal estuarine system or estuary outlet was defined for the basal member of the Alien Formation. In the sequential stratigraphy analysis the following systems were identified: a low accommodation system tract in a continental environment limited by a flooding fluvial surface (discontinuity I and discontinuity II; and a

  14. From Borders to Margins

    DEFF Research Database (Denmark)

    Parker, Noel

    2009-01-01

    upon Deleuze's philosophy to set out an ontology in which the continual reformulation of entities in play in ‘post-international' society can be grasped.  This entails a strategic shift from speaking about the ‘borders' between sovereign states to referring instead to the ‘margins' between a plethora...

  15. Deep continental margin reflectors

    Science.gov (United States)

    Ewing, J.; Heirtzler, J.; Purdy, M.; Klitgord, Kim D.

    1985-01-01

    In contrast to the rarity of such observations a decade ago, seismic reflecting and refracting horizons are now being observed to Moho depths under continental shelves in a number of places. These observations provide knowledge of the entire crustal thickness from the shoreline to the oceanic crust on passive margins and supplement Consortium for Continental Reflection Profiling (COCORP)-type measurements on land.

  16. Masculinity at the margins

    DEFF Research Database (Denmark)

    Jensen, Sune Qvotrup

    2010-01-01

    This article analyses how young marginalized ethnic minority men in Denmark react to the othering they are subject to in the media as well as in the social arenas of every day life. The article is based on theoretically informed ethnographic fieldwork among such young men as well as interviews an...

  17. Maintaining plant safety margins

    International Nuclear Information System (INIS)

    Bergeron, P.A.

    1989-01-01

    The Final Safety Analysis Report Forms the basis of demonstrating that the plant can operate safely and meet all applicable acceptance criteria. In order to assure that this continues through each operating cycle, the safety analysis is reexamined for each reload core. Operating limits are set for each reload core to assure that safety limits and applicable acceptance criteria are not exceeded for postulated events within the design basis. These operating limits form the basis for plant operation, providing barriers on various measurable parameters. The barriers are refereed to as limiting conditions for operation (LCO). The operating limits, being influenced by many factors, can change significantly from cycle to cycle. In order to be successful in demonstrating safe operation for each reload core (with adequate operating margin), it is necessary to continue to focus on ways to maintain/improve existing safety margins. Existing safety margins are a function of the plant type [boiling water reactor/pressurized water reactor (BWR/PWR)], nuclear system supply (NSSS) vendor, operating license date, core design features, plant design features, licensing history, and analytical methods used in the safety analysis. This paper summarizes the experience at Yankee Atomic Electric Company (YAEC) in its efforts to provide adequate operating margin for the plants that it supports

  18. Oceanography of marginal seas

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    The North Indian Ocean consists of three marginal seas; The Persian Gulf and the Red Sea in the west and the Andaman Sea in the east. Oceanographic features of these semi-enclosed basins have been discussed in this article. While circulation...

  19. Marginally Deformed Starobinsky Gravity

    DEFF Research Database (Denmark)

    Codello, A.; Joergensen, J.; Sannino, Francesco

    2015-01-01

    We show that quantum-induced marginal deformations of the Starobinsky gravitational action of the form $R^{2(1 -\\alpha)}$, with $R$ the Ricci scalar and $\\alpha$ a positive parameter, smaller than one half, can account for the recent experimental observations by BICEP2 of primordial tensor modes....

  20. Northeastern states sharpen biomass focus

    International Nuclear Information System (INIS)

    Lusk, P.D.

    1993-01-01

    Wood energy use in the northeastern region of the USA currently replaces an estimated annual equivalent of 45--50 million barrels of oil. Including municipal wastes and recovered methane emissions for regional landfills, total biomass contribution to the energy economy is over 70 million barrels of oil equivalent annually. A reasonable consensus suggests wood alone could replace the equivalent of over 300 million barrels of oil each year on a sustainable basis over the next two decades. Beyond energy security, over 60,000 total jobs are now provided in the region by the wood energy industry. Over 375,000 total jobs could be generated by the wood energy industry, about 65,000 in the harvesting, transportation, and end-use operations of the wood energy industry. Biomass producers must be committed to sustainable development by necessity. Sound forest management practices that keep residual stand damage from wood harvesting to a minimum can create positive impacts on the region's forest. When combined with a balanced energy policy, the conditional use of wood energy can play a modest, but significant, role in reducing air emissions. Depletion of traditional energy resources creates open-quotes bubbleclose quotes benefits which will be exhausted after a generation. Sustainable development of biomass can create inexhaustible wealth for generations, and does not pose the risk of sudden ecological disruption. While the choice between policy options is not mutually exclusive, the interrelationship between energy security, economic growth and environmental quality clearly favors biomass. The environmental benefits and the economic growth impacts of biobased products produced by the northeastern states are considerable. The 11 states located in the northeastern USA should intensify their efforts to work with industry and investors to expand markets for industrial biobased products, either produced from local feedstocks or manufactured by companies operating in the region

  1. Marginalized Youth. An Introduction.

    OpenAIRE

    Kessl, Fabian; Otto, Hans-Uwe

    2009-01-01

    The life conduct of marginalized groups has become subject to increasing levels of risk in advanced capitalist societies. In particular, children and young people are confronted with the harsh consequences of a “new poverty” in the contemporary era. The demographic complexion of today’s poverty is youthful, as a number of government reports have once again documented in recent years in Australia, Germany, France, Great Britain, the US or Scandinavian countries. Key youth studies have shown a ...

  2. Rio+20, biodiversity marginalized

    OpenAIRE

    Carrière, Stéphanie M.; Rodary, Estienne; Méral, Philippe; Serpantié, Georges; Boisvert, Valérie; Kull, C.A.; Lestrelin, Guillaume; Lhoutellier, Louise; Moizo, Bernard; Smektala, G.; Vandevelde, Jean-Christophe

    2013-01-01

    At the Rio+20 Conference (June 2012), the biodiversity conservation agenda was subsumed into broader environmental issues like sustainable development, “green economy,” and climate change. This shoehorning of biodiversity issues is concomitant with a trend toward market-based instruments and toward standardized biodiversity assessment and monitoring. This article raises concern that these trends can marginalize important and specific aspects of biodiversity governance, including other policy ...

  3. Containment safety margins

    International Nuclear Information System (INIS)

    Von Riesemann, W.A.

    1980-01-01

    Objective of the Containment Safety Margins program is the development and verification of methodologies which are capable of reliably predicting the ultimate load-carrying capability of light water reactor containment structures under accident and severe environments. The program was initiated in June 1980 at Sandia and this paper addresses the first phase of the program which is essentially a planning effort. Brief comments are made about the second phase, which will involve testing of containment models

  4. Dramatic reduction of sulfur dioxide emission in Northeastern China in the last decade

    Science.gov (United States)

    Yuan, J.

    2017-12-01

    Analysis of spatial and temporal variations of sulfur dioxide concentration in planetary boundary layer were conducted. The data were generated by NASA satellite daily from October of 2004 and were obtained through NASA Giovanni. The global monthly mean spatial distribution of sulfur dioxide showed several hot spots including: several spots on some islands in the Pacific Ocean, several spots in central America, and central Africa. Most of these hot spots of sulfur dioxide are related to known active volcanos. The biggest hot spot of sulfur dioxide were observed in Northeastern China. While high concentration sulfur dioxide was still observed in Northeastern China in 2017. The area averaged concentration of sulfur dioxide declined dramatically since its peak in 2008. This temporal trend indicates that sulfur reduction effort has been effective in the last decade or post 2008 financial crisis recovery lead an industry less sulfur dioxide emission.

  5. Paleogeography of Cretaceous ammonoids of the Pacific coast of Russia

    Science.gov (United States)

    Jagt-Yazykova, E. A.; Zonova, T. D.

    2012-05-01

    This work presents the results of a study of the biogeographical distribution of Late Albian-Maastrichtian ammonites, found in sequences of the Pacific coast of Russia. The taxa typical of the Pacific Realm were identified, and their distribution traced beyond the borders of this region. In addition, species-migrants, distributed within the studied area were established. As a results of our works, a high level of endemism of ammonite fauna of the East of Russia was noted (75-88% of endemic species, on average). The bipolarity, previously established in the distribution of ammonoids within the Pacific Paleobiogeographical Realm, as well as their high regional provincialism, was confirmed. The following division of the studied area into faunal ammonite provinces in the Late Cretaceous was proposed: Arctic Province; Boreal-Pacific Province, including northeastern Russia (Chukotka Peninsula, the Koryak Upland, Penzhyna Gulf) and the boreal coast of North America (Alaska Peninsula, Arctic Canada and British Columbia); Northwest Pacific Province, including the Primorye Territory, Sakhalin and Shikotan Islands, the Japanese Islands; Northeast Province of the Pacific (the western coast of the United States and Mexico); Southwest Pacific (Australia, New Zealand, Oceania) and Southeast (the western coast of South America and Antarctica, Seymour and James Ross Islands) Provinces. This division is confirmed by data on inoceramid species. In addition, levels of global transgressions and general sea level rise, associated with the appearances of most of widespread marine taxa in the Pacific shelf seas, are established. These include Late Albian, Cenomanian-Turonian boundary, Late Coniacian, Late Campanian, Early-Late Maastrichtian boundary. Moreover, migration of ammonites occurred due to the Tethys Ocean extension and followed the northern sea straits in the Arctic Ocean and within the Pacific Realm, depending on warm currents. Both the counter and one-way migrations were

  6. Asia-Pacific lube oil markets

    International Nuclear Information System (INIS)

    Yamaguchi, N.

    2001-01-01

    An overview of the Asia-Pacific (AP) lubricating oils market, its special characteristics, and its role in the global economy are presented. In the 'boom and bust' years of 1997-1999, the Asia-Pacific market was even bigger then the US market. For the short-term, the scenario is surplus capacity and poor margins, but in the long term there is enormous potential for growth. How fuel demand and quality is related to engine type is discussed. The three basic grades of baseoils are described, and the Asia-Pacific lube demand and the Asia-Pacific lube oil supply are discussed. There are 15 diagrams giving data on: (i) finished lubes in world markets as a percentage of total; (ii) how lube demand follows GDP per capita in Asia; (iii) AP baseoil capacity relationships; (iv) AP baseoil disposition by end use; (v) AP changing shares of baseoil demand; (vi) AP finished lube demand by subregion; (vii) AP finished lube demand growth, indexed; (viii) AP baseoil capacity by region; Singapore baseoil vs. Dubai crude prices, 1992-99; (ix) Singapore baseoil vs. crude prices, 1992-99; (x) AP baseoil deficit moved to surplus; (xi) AP baseoil production; (xii) East Asia net percentage change in lube sales, 1997-1999. (xiii) Southeast Asia net percentage change in lube sales, 1997-1999; (xiv) South East Asia and Australia net percentage change in lube sales, 1997-1999 and (xv) Asia-Pacific major lube marketers

  7. Amphetamine margin in sports

    Energy Technology Data Exchange (ETDEWEB)

    Laties, V.G.; Weiss, B.

    1981-10-01

    The amphetamines can enhance athletic performance. That much seem clear from the literature, some of which is reviewed here. Increases in endurance have been demonstrated in both humans and rats. Smith and Beecher, 20 years ago, showed improvement of running, swimming, and weight throwing in highly trained athletes. Laboratory analogs of such performances have also been used and similar enhancement demonstrated. The amount of change induced by the amphetamines is usually small, of the order of a few percent. Nevertheless, since a fraction of a percent improvement can make the difference between fame and oblivion, the margin conferred by these drugs can be quite important.

  8. Geophysical constraints on geodynamical processes at convergent margins

    DEFF Research Database (Denmark)

    Artemieva, Irina; Thybo, Hans; Shulgin, Alexey

    2016-01-01

    Convergent margins, being the boundaries between colliding lithospheric plates, form the most disastrous areas in the world due to intensive, strong seismicity and volcanism. We review global geophysical data in order to illustrate the effects of the plate tectonic processes at convergent margins......, at least, one of the plates is oceanic. However, the oldest oceanic plate in the Pacific ocean has the smallest convergence rate. (2) The presence of an oceanic plate is, in general, required for generation of high-magnitude (M>8.0) earthquakes and for generating intermediate and deep seismicity along...... on the crustal and upper mantle structure, seismicity, and geometry of subducting slab. We present global maps of free-air and Bouguer gravity anomalies, heat flow, seismicity, seismic Vs anomalies in the upper mantle, and plate convergence rate, as well as 20 profiles across different convergent margins...

  9. POLA KEBERAGAMAAN MASYARAKAT MARGINAL

    Directory of Open Access Journals (Sweden)

    Ahmad Muttaqin

    2016-11-01

    Full Text Available This is a research on sociology of religion, focusing on the issue of religious practices in a local community. Kampung Laut was chosen as the setting of this research for two reasons. First, the rituals of religion practices in the region are different from mainstream practices, which result in label and justification that their religiosity is not a part of or only a fragment of the mainstream religion and tend to be the target of correction. Second, this region raises conflicts among government institutions in relation to the rights of natural resources possession and utilization. The bad image built through this marginalization has formed Kampung Laut community as the one that is resistant and latent. This research used descriptive qualitative method with sociological approach. Rituals of religious practices that are different from the mainstream are explained on the basis of Weber’s theory of behavior categorized into value-oriented rationality. This kind of practices is considered to be more beneficial in the context of struggling for identity among the practices of marginalization experienced by Kampung Laut community. This condition gives a description to public that Kampung Laut community receives unfair treatments for their natural resources. Religious issues is made an entry for its massive, communal, and related to transcendental values.

  10. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  11. Latest Miocene transtensional rifting of northeast Isla Tiburón, eastern margin of the Gulf of California

    Science.gov (United States)

    Bennett, Scott E. K.; Oskin, Michael E.; Iriondo, Alexander

    2017-11-01

    Details about the timing and kinematics of rifting are crucial to understand the conditions that led to strain localization, continental rupture, and formation of the Gulf of California ocean basin. We integrate detailed geologic and structural mapping, basin analysis, and geochronology to characterize transtensional rifting on northeastern Isla Tiburón, a proximal onshore exposure of the rifted North America margin, adjacent to the axis of the Gulf of California. Slip on the Kunkaak normal fault tilted its hanging wall down-to-the-east 70° and formed the non-marine Tecomate basin, deposited across a 20° angular unconformity. From 7.1-6.4 Ma, the hanging wall tilted at 35 ± 5°/Myr, while non-marine sandstone and conglomerate accumulated at 1.4 ± 0.2 mm/yr. At least 1.8 ± 0.1 km of sediments and pyroclastic deposits accumulated in the Tecomate basin concurrent with clockwise vertical-axis block rotation and 2.8 km of total dip-slip motion on the Kunkaak fault. Linear extrapolation of tilting and sedimentation rates suggests that faulting and basin deposition initiated 7.6-7.4 Ma, but an older history involving initially slower rates is permissible. The Kunkaak fault and Tecomate basin are truncated by NW-striking, dextral-oblique structures, including the Yawassag fault, which accrued > 8 km of post-6.4 Ma dextral displacement. The Coastal Sonora fault zone on mainland Sonora, which accrued several tens of kilometers of late Miocene dextral offset, continues to the northwest, across northeastern Isla Tiburón and offshore into the Gulf of California. The establishment of rapid, latest Miocene transtension in the Coastal Sonora fault zone was synchronous with the 8-7 Ma onset of transform faulting and basin formation along the nascent Pacific-North America plate boundary throughout northwestern Mexico and southern California. Plate boundary strain localized into this Gulf of California shear zone, a narrow transtensional belt that subsequently hosted the

  12. Regional geologic framework off northeastern United States

    Science.gov (United States)

    Schlee, J.; Behrendt, John C.; Grow, J.A.; Robb, James M.; Mattick, R.; Taylor, P.T.; Lawson, B.J.

    1976-01-01

    Six multichannel seismic-reflection profiles taken across the Atlantic continental margin Previous HitoffTop the northeastern United States show an excess of 14 km of presumed Mesozoic and younger sedimentary rocks in the Baltimore Canyon trough and 8 km in the Georges Bank basin. Beneath the continental rise, the sedimentary prism thickness exceeds 7 km south of New Jersey and Maryland, and it is 4.5 km thick south of Georges Bank. Stratigraphically, the continental slope--outer edge of the continental shelf is a transition zone of high-velocity sedimentary rock, probably carbonate, that covers deeply subsided basement. Acoustically, the sedimentary sequence beneath the shelf is divided into three units which are correlated speculatively with the Cenozoic, the Cretaceous, and the Jurassic-Triassic sections. These units thicken offshore, and some have increased seismic velocities farther offshore. The uppermost unit thickens from a fraction of a kilometer to slightly more than a kilometer in a seaward direction, and velocity values range from 1.7 to 2.2 km/sec. The middle unit thickens from a fraction of a kilometer to as much as 5 km (northern Baltimore Canyon trough), and seismic velocity ranges from 2.2 to 5.4 km/sec. The lowest unit thickens to a maximum of 9 km (northern Baltimore Canyon), and velocities span the 3.9 to 5.9-km/sec interval. The spatial separation of magnetic and gravity anomalies on line 2 (New Jersey) suggests that in the Baltimore Canyon region the magnetic-slope anomaly is due to edge effects and that the previously reported free-air and isostatic gravity anomalies over the outer shelf may be due in part to a lateral increase in sediment density (velocity) near the shelf edge. The East Coast magnetic anomaly and the free-air gravity high both coincide over the outer shelf edge on line 1 (Georges Bank) but are offset by 20 km from the ridge on the reflection profile. Because the magnetic-slope-anomaly wavelength is nearly 50 km across, a

  13. Phanerozoic tectonic evolution of the Circum-North Pacific

    Science.gov (United States)

    Nokleberg, Warren J.; Parfenov, Leonid M.; Monger, James W.H.; Norton, Ian O.; Khanchuk, Alexander I.; Stone, David B.; Scotese, Christopher R.; Scholl, David W.; Fujita, Kazuya

    2000-01-01

    The Phanerozoic tectonic evolution of the Circum-North Pacific is recorded mainly in the orogenic collages of the Circum-North Pacific mountain belts that separate the North Pacific from the eastern part of the North Asian Craton and the western part of the North American Craton. These collages consist of tectonostratigraphic terranes that are composed of fragments of igneous arcs, accretionary-wedge and subduction-zone complexes, passive continental margins, and cratons; they are overlapped by continental-margin-arc and sedimentary-basin assemblages. The geologic history of the terranes and overlap assemblages is highly complex because of postaccretionary dismemberment and translation during strike-slip faulting that occurred subparallel to continental margins.We analyze the complex tectonics of this region by the following steps. (1) We assign tectonic environments for the orogenic collages from regional compilation and synthesis of stratigraphic and faunal data. The types of tectonic environments include cratonal, passive continental margin, metamorphosed continental margin, continental-margin arc, island arc, oceanic crust, seamount, ophiolite, accretionary wedge, subduction zone, turbidite basin, and metamorphic. (2) We make correlations between terranes. (3) We group coeval terranes into a single tectonic origin, for example, a single island arc or subduction zone. (4) We group igneous-arc and subduction- zone terranes, which are interpreted as being tectonically linked, into coeval, curvilinear arc/subduction-zone complexes. (5) We interpret the original positions of terranes, using geologic, faunal, and paleomagnetic data. (6) We construct the paths of tectonic migration. Six processes overlapping in time were responsible for most of the complexities of the collage of terranes and overlap assemblages around the Circum-North Pacific, as follows. (1) During the Late Proterozoic, Late Devonian, and Early Carboniferous, major periods of rifting occurred along

  14. Pacific Equatorial Transect

    OpenAIRE

    Pälike, Heiko; Nishi, Hiroshi; Lyle, Mitch; Raffi, Isabella; Klaus, Adam; Gamage, Kusali

    2009-01-01

    Integrated Ocean Drilling Program Expedition 320/321, "Pacific Equatorial Age Transect" (Sites U1331–U1338), was designed to recover a continuous Cenozoic record of the paleoequatorial Pacific by coring above the paleoposition of the Equator at successive crustal ages on the Pacific plate. These sediments record the evolution of the paleoequatorial climate system throughout the Cenozoic. As we gained more information about the past movement of plates and when in Earth's history "critical" cli...

  15. Workers' marginal costs of commuting

    DEFF Research Database (Denmark)

    van Ommeren, Jos; Fosgerau, Mogens

    2009-01-01

    This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour...

  16. The Pacific University Alliance

    International Nuclear Information System (INIS)

    Peddicord, K.L.; Graham, J.A.

    1996-01-01

    The Pacific University Alliance represents a partnership between universities from the Pacific Rim countries in North America and Asia with international companies in the field of nuclear technology. This partnership builds on a strong academic base to address 'world problems' and to prepare students to meet the challenges for the global nuclear industry of the 21st century. (author)

  17. PACIFIC NORTHWEST CYBER SUMMIT

    Energy Technology Data Exchange (ETDEWEB)

    Lesperance, Ann M.; Matlock, Gordon W.; Becker-Dippmann, Angela S.; Smith, Karen S.

    2013-08-07

    On March 26, 2013, the Snohomish County Public Utility District (PUD) and the U.S. Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) jointly hosted the Pacific Northwest Cyber Summit with the DOE’s Office of Electricity Delivery and Energy Reliability, the White House, Washington State congressional delegation, Washington State National Guard, and regional energy companies.

  18. Asia Pacific energy derivatives

    International Nuclear Information System (INIS)

    Fusaro, P.C.

    1997-09-01

    Asia Pacific Energy Derivatives, from FT Energy, is the first report of its kind to examine the growth of energy derivatives within Asia Pacific and their increasing importance within this region. It provides a comprehensive overview of the subject, including analysis of: deregulation as a market driver; the impact of privatisation; the future for energy risk management tools; the unique characteristics of the Asia Pacific energy market; the role of futures exchanges in Asia; existing indexes and their performance; the differences between the Asia Pacific markets and their more mature counterparts in London and New York; non-oil derivatives, project finance and cross commodity arbitrage; the thriving Pacific Rim Over the Counter (OTC) markets. (author)

  19. Philopatry and migration of Pacific white sharks.

    Science.gov (United States)

    Jorgensen, Salvador J; Reeb, Carol A; Chapple, Taylor K; Anderson, Scot; Perle, Christopher; Van Sommeran, Sean R; Fritz-Cope, Callaghan; Brown, Adam C; Klimley, A Peter; Block, Barbara A

    2010-03-07

    Advances in electronic tagging and genetic research are making it possible to discern population structure for pelagic marine predators once thought to be panmictic. However, reconciling migration patterns and gene flow to define the resolution of discrete population management units remains a major challenge, and a vital conservation priority for threatened species such as oceanic sharks. Many such species have been flagged for international protection, yet effective population assessments and management actions are hindered by lack of knowledge about the geographical extent and size of distinct populations. Combining satellite tagging, passive acoustic monitoring and genetics, we reveal how eastern Pacific white sharks (Carcharodon carcharias) adhere to a highly predictable migratory cycle. Individuals persistently return to the same network of coastal hotspots following distant oceanic migrations and comprise a population genetically distinct from previously identified phylogenetic clades. We hypothesize that this strong homing behaviour has maintained the separation of a northeastern Pacific population following a historical introduction from Australia/New Zealand migrants during the Late Pleistocene. Concordance between contemporary movement and genetic divergence based on mitochondrial DNA demonstrates a demographically independent management unit not previously recognized. This population's fidelity to discrete and predictable locations offers clear population assessment, monitoring and management options.

  20. Statistical Characteristics of Mesoscale Eddies in the North Pacific Derived from Satellite Altimetry

    Directory of Open Access Journals (Sweden)

    Yu-Hsin Cheng

    2014-06-01

    Full Text Available The sea level anomaly data derived from satellite altimetry are analyzed to investigate statistical characteristics of mesoscale eddies in the North Pacific. Eddies are detected by a free-threshold eddy identification algorithm. The results show that the distributions of size, amplitude, propagation speed, and eddy kinetic energy of eddy follow the Rayleigh distribution. The most active regions of eddies are the Kuroshio Extension region, the Subtropical Counter Current zone, and the Northeastern Tropical Pacific region. By contrast, eddies are seldom observed around the center of the eastern part of the North Pacific Subarctic Gyre. The propagation speed and kinetic energy of cyclonic and anticyclonic eddies are almost the same, but anticyclonic eddies possess greater lifespans, sizes, and amplitudes than those of cyclonic eddies. Most eddies in the North Pacific propagate westward except in the Oyashio region. Around the northeastern tropical Pacific and the California currents, cyclonic and anticyclonic eddies propagate westward with slightly equatorward (197° average azimuth relative to east and poleward (165° deflection, respectively. This implies that the background current may play an important role in formation of the eddy pathway patterns.

  1. Outbreak of Ips nitidus and Ips shangrila in northeastern margin of the Tibetan Plateau

    Czech Academy of Sciences Publication Activity Database

    Jakuš, R.; Kalinová, Blanka; Hoskovec, Michal; Knížek, M.; Schlyter, F.; Sun, J.-H.; Zhang, Q. H.

    2011-01-01

    Roč. 89, - (2011), s. 111-117 ISSN 1436-1566 R&D Projects: GA MŠk ME 860 Institutional research plan: CEZ:AV0Z40550506 Keywords : Ips shangrila * Ips nitidus * pheromones * GCxGC-TOFMS Subject RIV: CC - Organic Chemistry

  2. Educational Marginalization: Examining Challenges and Possibilities for Improving Educational Outcomes in Northeastern Kenya

    Science.gov (United States)

    Okilwa, Nathern S. A.

    2015-01-01

    As a developing country in sub-Saharan Africa, Kenya has fared comparatively well in educating its young people. The new constitution of Kenya and various acts of parliament identify education as a fundamental human right and mandates the government to provide basic education for all. Consistent with the government's "Vision 2030," most…

  3. Uplift history of a transform continental margin revealed by the stratigraphic record: The case of the Agulhas transform margin along the Southern African Plateau

    Science.gov (United States)

    Baby, Guillaume; Guillocheau, François; Boulogne, Carl; Robin, Cécile; Dall'Asta, Massimo

    2018-04-01

    The south and southeast coast of southern Africa (from 28°S to 33°S) forms a high-elevated transform passive margin bounded to the east by the Agulhas-Falkland Fracture Zone (AFFZ). We analysed the stratigraphic record of the Outeniqua and Durban (Thekwini) Basins, located on the African side of the AFFZ, to determine the evolution of these margins from the rifting stage to present-day. The goal was to reconstruct the strike-slip evolution of the Agulhas Margin and the uplift of the inland high-elevation South African Plateau. The Agulhas transform passive margin results from four successive stages: Rifting stage, from Late Triassic to Early Cretaceous ( 200?-134 Ma), punctuated by three successive rifting episodes related to the Gondwana breakup; Wrench stage (134-131 Ma), evidenced by strike- and dip-slip deformations increasing toward the AFFZ; Active transform margin stage (131-92 Ma), during which the Falkland/Malvinas Plateau drifts away along the AFFZ, with an uplift of the northeastern part of the Outeniqua Basin progressively migrating toward the west; Thermal subsidence stage (92-0 Ma), marked by a major change in the configuration of the margin (onset of the shelf-break passive margin morphology). Two main periods of uplift were documented during the thermal subsidence stage of the Agulhas Margin: (1) a 92 Ma short-lived margin-scale uplift, followed by a second one at 76 Ma located along the Outeniqua Basin and; (2) a long-lasting uplift from 40 to 15 Ma limited to the Durban (Thekwini) Basin. This suggests that the South African Plateau is an old Upper Cretaceous relief (90-70 Ma) reactivated during Late Eocene to Early Miocene times (40-15 Ma).

  4. Uranium in phosphorites of submarine untains in the Pacific Ocean

    International Nuclear Information System (INIS)

    Baturin, G.N.; Kochenov, A.V.; Dubinchuk, V.T.

    1982-01-01

    Uranium geochemical behaviour was studied under present sharply oxidizing conditions of sedimentation within the boundaries of submarine mountains in the Pacific Ocean (pelagic zone). It has been ascertained that the uranium content in phosphorites of submarine mountains in the Pacific Ocean does not exceed 10 -4 % which is considerably lower as compared phosphorites of submarine margins of the continents and terrestrial deposits. Iron and manganese hydroxides are the most active concentrators of uranium in a sharply oxidizing environment and to a lesser degree - phosphates, silicates, carbonates. Uranium bonded to phosphate is not an isomorphic impurity in it [ru

  5. Linguistic Diversity in the Pacific.

    Science.gov (United States)

    Crowley, Terry

    1999-01-01

    Reviews Peter Muhlhausler's book "Linguistic Ecology: Language Change and Linguistic Imperialism in the Pacific Region." Discusses the linguistic diversity of the Pacific, the linguistic impact of colonialism in the Pacific, and the role of linguists in the evolving linguistic situation in the Pacific. (Author/VWL)

  6. New species of Xiphocentron Brauer 1870 (Trichoptera: Xiphocentronidae) from Northeastern Brazil.

    Science.gov (United States)

    Vilarino, Albane; Calor, Adolfo R

    2015-01-23

    Two new species of Xiphocentron (Trichoptera: Xiphocentronidae) from Northeastern Brazil are diagnosed, described, and illustrated. Xiphocentron (Antillotrichia) kamakan n. sp. has inferior appendages each with a shape discontinuity (twist) between the first and second articles of inferior appendage, similar to that found in X. (Antillotrichia) rhamnes Schmid 1982, X. (Antillotrichia) serestus Schmid 1982, and X. (Antillotrichia) mnesteus Schmid 1982; however, it can be distinguished from these species by each inferior appendage having two darkly sclerotized spinulous regions ventrally on the basomesal and midmesal margins. Xiphocentron (Antillotrichia) maiteae n. sp. can be differentiated from all other congeners by having the basoventral margin of each inferior appendage strongly produced posterad. A key to males of Brazilian species of Xiphocentron is provided. 

  7. Pushing the Margins of Responsibility

    DEFF Research Database (Denmark)

    Santoni de Sio, Filippo; Di Nucci, Ezio

    2018-01-01

    marginal responsibility in three steps: we first deny that Parks acts involuntarily as traditionally claimed in the legal literature; we then propose to extend Shoemaker’s analysis of marginal responsibility based on quality of will so as to include two other dimensions: the moral status of the agent......David Shoemaker has claimed that a binary approach to moral responsibility leaves out something important, namely instances of marginal agency, cases where agents seem to be eligible for some responsibility responses but not others. In this paper we endorse and extend Shoemaker’s approach...... by presenting and discussing one more case of marginal agency not yet covered by Shoemaker or in the other literature on moral responsibility. Our case is that of Kenneth Parks, a Canadian man who drove a long way to his mother-in-law’s and killed her in a state of somnambulism. We support our claim about Parks...

  8. Dengue Virus Serotype 4, Northeastern Peru, 2008

    Science.gov (United States)

    Forshey, Brett M.; Morrison, Amy C.; Cruz, Cristhopher; Rocha, Claudio; Vilcarromero, Stalin; Guevara, Carolina; Camacho, Daria E.; Alava, Araceli; Madrid, César; Beingolea, Luis; Suarez, Víctor; Comach, Guillermo

    2009-01-01

    In 2008, dengue virus serotype 4 (DENV-4) emerged in northeastern Peru, causing a large outbreak and displacing DENV-3, which had predominated for the previous 6 years. Phylogenetic analysis of 2008 and 2009 isolates support their inclusion into DENV-4 genotype II, forming a lineage distinct from strains that had previously circulated in the region. PMID:19891873

  9. CHARCOAL-PRODUCING INDUSTRIES IN NORTHEASTERN BRAZIL

    Science.gov (United States)

    Charcoal workers in northeastern Brazil: Occupational risks and effects of exposure to wood smokeABSTRACTBrazil has the largest production of charcoal in the world, which is used mostly in the iron and steel industries. In most of the production sites, the process is ba...

  10. Climatic change in northeastern Brazil: paleoparasitological data

    Directory of Open Access Journals (Sweden)

    Adauto Araujo

    1993-12-01

    Full Text Available Trichuris eggs were observed in Kerodon rupestris coprolites dated 9,000 years before present, collected in archeological sites of São Raimundo Nonato, northeastern Brazil. However, present day local rodents seem not to be infected by the parasite, suggesting its disappearence due to climatic changes.

  11. Closing the North American Carbon Budget: Continental Margin Fluxes Matter!

    Science.gov (United States)

    Najjar, R.; Benway, H. M.; Siedlecki, S. A.; Boyer, E. W.; Cai, W. J.; Coble, P. G.; Cross, J. N.; Friedrichs, M. A.; Goni, M. A.; Griffith, P. C.; Herrmann, M.; Lohrenz, S. E.; Mathis, J. T.; McKinley, G. A.; Pilskaln, C. H.; Smith, R. A.; Alin, S. R.

    2015-12-01

    Despite their relatively small surface area, continental margins are regions of intense carbon and nutrient processing, export and exchange, and thus have a significant impact on global biogeochemical cycles. In response to recommendations for regional synthesis and carbon budget estimation for North America put forth in the North American Continental Margins workshop report (Hales et al., 2008), the Ocean Carbon and Biogeochemistry (OCB) Program and North American Carbon Program (NACP) began coordinating a series of collaborative, interdisciplinary Coastal CARbon Synthesis (CCARS) research activities in five coastal regions of North America (Atlantic Coast, Pacific Coast, Gulf of Mexico, Arctic, Laurentian Great Lakes) to improve quantitative assessments of the North American carbon budget. CCARS workshops and collaborative research activities have resulted in the development of regional coastal carbon budgets based on recent literature- and model-based estimates of major carbon fluxes with estimated uncertainties. Numerous peer-reviewed papers and presentations by involved researchers have highlighted these findings and provided more in-depth analyses of processes underlying key carbon fluxes in continental margin systems. As a culminating outcome of these synthesis efforts, a comprehensive science plan highlights key knowledge gaps identified during this synthesis and provides explicit guidance on future research and observing priorities in continental margin systems to help inform future agency investments in continental margins research. This presentation will provide an overview of regional and flux-based (terrestrial inputs, biological transformations, sedimentary processes, atmospheric exchanges, lateral carbon transport) synthesis findings and key recommendations in the science plan, as well as a set of overarching priorities and recommendations on observations and modeling approaches for continental margin systems.

  12. Comparison of non-indigenous dwarf eelgrass (Zostera japonica) and native eelgrass (Z. marina) distributions in a northeast Pacific estuary: 1997-2014

    Science.gov (United States)

    This study addressed the following question: In a coastal estuary of the northeastern Pacific Ocean with a relatively large areal extent of the native eelgrass Zostera marina, is an expanding distribution of the non-indigenous dwarf eelgrass Z. japonica accompanied by a measurab...

  13. Two new species and a remarkable record of the genus Dendronotus from the North Pacific and Arctic oceans (Nudibranchia

    Directory of Open Access Journals (Sweden)

    Tatiana Korshunova

    2016-11-01

    Full Text Available Two new species of the nudibranch genus Dendronotus, D. arcticus sp. n. and D. robilliardi sp. n., are described from the Arctic and North Pacific oceans respectively, based on morphological and molecular data, and the North Pacific D. albus is revealed to be a species complex. The species D. robilliardi sp. n. is described from the northwestern Pacific (Kamchatka differing from the northeastern Pacific D. albus by molecular and morphological data. The synonymy of D. diversicolor with D. albus is confirmed by analysis of their original descriptions. An endemic Arctic species D. arcticus sp. n. is also described here, differing substantially from all species of the genus Dendronotus using morphological and molecular data. An unusual record of the recently described D. kamchaticus Ekimova, Korshunova, Schepetov, Neretina, Sanamyan, Martynov, 2015 is also presented, the first from the northeastern Pacific, geographically separated from the type locality of this species in the northwestern Pacific by a distance ca. 6000 km; molecular data show them to belong to the same species.

  14. Plate Coupling and Strain Partitioning in the Northeastern Caribbean

    Science.gov (United States)

    Manaker, D.; Calais, E.; Jansma, P.; Mattioli, G.

    2006-12-01

    Major strike-slip faults commonly found on the margin of overriding plates in oblique subduction zone settings facilitate the partitioning of strain into trench-parallel and trench-normal tectonics. Their development has been proposed to be controlled by factors such as convergence obliquity, basal tractions, magnitude of slab-pull force, or strength of interplate coupling. In the northeastern Caribbean, the direction of GPS velocities and earthquake slip vectors suggests low coupling along the Puerto Rico and Lesser Antilles trenches, but strong coupling to the west along the Hispaniola margin, while the convergence obliquity remains constant. Coincidentally, large strike-slip faults in the overriding plate only develop in Hispaniola, which is also the locus of the largest historical subduction earthquakes in the Caribbean (M8.0, 1946-53 sequence). We investigate interplate coupling at the Caribbean-North American plate boundary using a model that allows for block rotations and elastic strain accumulation on partially coupled faults. Model parameters (block rotations and coupling on interplate faults) are derived from an inversion of earthquake slip vectors and new GPS data covering Haiti, the Dominican Republic, Puerto Rico and the Virgin Islands, and the Lesser Antilles. We find that intraplate coupling is high in the western half of the domain, coincident with the development of large and fast-slipping strike-slip faults in the upper plate that partition the Carribean/North America plate motion, but low in its eastern half, along the Puerto Rico and Lesser Antilles subductions, that show little to no strain partitioning. This suggests that strain partitioning occur only if interplate coupling is large enough to effectively transfer shear stresses to the overriding plate.

  15. Passive margins through earth history

    Science.gov (United States)

    Bradley, Dwight C.

    2008-12-01

    Passive margins have existed somewhere on Earth almost continually since 2740 Ma. They were abundant at 1900-1890, 610-520, and 150-0 Ma, scarce at ca. 2445-2300, 1600-1000, and 300-275 Ma, and absent before ca. 3000 Ma and at 1740-1600. The fluctuations in abundance of passive margins track the first-order fluctuations of the independently derived seawater 87Sr/ 86Sr secular curve, and the compilation thus appears to be robust. The 76 ancient passive margins for which lifespans could be measured have a mean lifespan of 181 m.y. The world-record holder, with a lifespan of 590 m.y., is the Mesoproterozoic eastern margin of the Siberian craton. Subdivided into natural age groups, mean lifespans are 186 m.y. for the Archean to Paleoproterozoic, 394 m.y. for the Mesoproterozoic, 180 m.y. for the Neoproterozoic, 137 m.y. for the Cambrian to Carboniferous, and 130 m.y. for the Permian to Neogene. The present-day passive margins, which are not yet finished with their lifespans, have a mean age of 104 m.y. and a maximum age of 180 m.y. On average, Precambrian margins thus had longer, not shorter, lifespans than Phanerozoic ones—and this remains the case even discounting all post-300 Ma margins, most of which have time left. Longer lifespans deeper in the past is at odds with the widely held notion that the tempo of plate tectonics was faster in the Precambrian than at present. It is entirely consistent, however, with recent modeling by Korenaga [Korenaga, J., 2004. Archean geodynamics and thermal evolution of Earth. Archean Geodynamics and Environments, AGU Geophysical Monograph Series 164, 7-32], which showed that plate tectonics was more sluggish in the Precambrian. The abundance of passive margins clearly tracks the assembly, tenure, and breakup of Pangea. Earlier parts of the hypothesized supercontinent cycle, however, are only partly consistent with the documented abundance of passive margins. The passive-margin record is not obviously consistent with the proposed

  16. A pastoral landscape for millennia: Investigating pastoral mobility in northeastern Jordan using quantitative spatial analyses

    Science.gov (United States)

    Meister, Julia; Knitter, Daniel; Krause, Jan; Müller-Neuhof, Bernd; Schütt, Brigitta

    2017-04-01

    Northeastern Jordan is one of the few remaining regions in the Middle East where pastoral nomadism is still practiced. In this desert region, pastoral mobility is an adapted land use—able to cope with low rainfall rates, great seasonal and annual rainfall variations and thus heterogeneous vegetation and water availability. During winter, herders and their livestock move into the desert; in summer they move to the desert margins to places with perennial water supply. The system of mobile pastoralism was introduced during the Early Late Neolithic. Within the basaltic region of northeastern Jordan, there is a dense distribution of archeological remains; some of them can be linked to pastoral groups due to the herders' ancient practice of building agglomerations of sub-circular enclosures ('clustered enclosures') made of basalt boulders for corralling their flocks and domestic activities. The resulting features provide an excellent opportunity to investigate a pastoral landscape that has been frequently used by herders during the last eight to nine millennia. In this study, 9118 clustered enclosures in the northeastern Jordanian basalt desert have been systematically recorded using satellite imagery. In order to investigate potential migration or communication routes, grazing lands and social interactions of former pastoralists, we examine their first- and second-order characteristics using distance and density based approaches of point pattern analyses by integrating geomorphometric and geomorphological site properties. The results of this spatial analysis are combined with available archaeological data and a review on traditional herding practices in northeastern Jordan. Overall, the results demonstrate that the observed spatial distribution of clustered enclosures is influenced locally by natural characteristics but regionally by cultural practices.

  17. Circum-North Pacific tectonostratigraphic terrane map

    Science.gov (United States)

    Nokleberg, Warren J.; Parfenov, Leonid M.; Monger, James W.H.; Baranov, Boris B.; Byalobzhesky, Stanislav G.; Bundtzen, Thomas K.; Feeney, Tracey D.; Fujita, Kazuya; Gordey, Steven P.; Grantz, Arthur; Khanchuk, Alexander I.; Natal'in, Boris A.; Natapov, Lev M.; Norton, Ian O.; Patton, William W.; Plafker, George; Scholl, David W.; Sokolov, Sergei D.; Sosunov, Gleb M.; Stone, David B.; Tabor, Rowland W.; Tsukanov, Nickolai V.; Vallier, Tracy L.; Wakita, Koji

    1994-01-01

    The companion tectonostratigraphic terrane and overlap assemblage of map the Circum-North Pacific presents a modern description of the major geologic and tectonic units of the region. The map illustrates both the onshore terranes and overlap volcanic assemblages of the region, and the major offshore geologic features. The map is the first collaborative compilation of the geology of the region at a scale of 1:5,000,000 by geologists of the Russian Far East, Japanese, Alaskan, Canadian, and U.S.A. Pacific Northwest. The map is designed to be a source of geologic information for all scientists interested in the region, and is designed to be used for several purposes, including regional tectonic analyses, mineral resource and metallogenic analyses (Nokleberg and others, 1993, 1994a), petroleum analyses, neotectonic analyses, and analyses of seismic hazards and volcanic hazards. This text contains an introduction, tectonic definitions, acknowledgments, descriptions of postaccretion stratified rock units, descriptions and stratigraphic columns for tectonostratigraphic terranes in onshore areas, and references for the companion map (Sheets 1 to 5). This map is the result of extensive geologic mapping and associated tectonic studies in the Russian Far East, Hokkaido Island of Japan, Alaska, the Canadian Cordillera, and the U.S.A. Pacific Northwest in the last few decades. Geologic mapping suggests that most of this region can be interpreted as a collage of fault-bounded tectonostratigraphic terranes that were accreted onto continental margins around the Circum-

  18. Tectonic map of the Circum-Pacific region, Pacific basin sheet

    Science.gov (United States)

    Scheibner, E.; Moore, G.W.; Drummond, K.J.; Dalziel, Corvalan Q.J.; Moritani, T.; Teraoka, Y.; Sato, T.; Craddock, C.

    2013-01-01

    George W. Moore (Arctic Region). Project coordination and final cartography was being carried out through the cooperation of the Office of the Chief Geologist of the U.S. Geological Survey, under the direction of General Chairman, George Gryc of Menlo Park, California. Project headquarters were located at 345 Middlefield Road, MS 952, Menlo Park, California 94025, U.S.A. The framework for the Circum-Pacific Map Project was developed in 1973 by a specially convened group of 12 North American geoscientists meeting in California. The project was officially launched at the First Circum-Pacific Conference on Energy and Mineral Resources, which met in Honolulu, Hawaii, in August 1974. Sponsors of the conference were the AAPG, Pacific Science Association (PSA), and the Coordinating Committee for Offshore Prospecting for Mineral Resources in Offshore Asian Areas (CCOP). The Circum-Pacific Map Project operates as an activity of the Circum-Pacific Council for Energy and Mineral Resources, a nonprofit organization that promotes cooperation among Circum-Pacific countries in the study of energy and mineral resources of the Pacific basin. Founded by Michel T. Halbouty in 1972, the Council also sponsors conferences, topical symposia, workshops and the Earth Science Series books. Tectonic Map Series: The tectonic maps distinguish areas of oceanic and continental crust. Symbols in red mark active plate boundaries, and colored patterns show tectonic units (volcanic or magmatic arcs, arc-trench gaps, and interarc basins) associated with active plate margins. Well-documented inactive plate boundaries are shown by symbols in black. The tectonic development of oceanic crust is shown by episodes of seafloor spreading. These correlate with the rift and drift sequences at passive continental margins and episodes of tectonic activity at active plate margins. The recognized episodes of seafloor spreading seem to reflect major changes in plate kinematics. Oceanic plateaus and other prominences of

  19. Cenozoic tectonic jumping and implications for hydrocarbon accumulation in basins in the East Asia Continental Margin

    Science.gov (United States)

    Suo, Yanhui; Li, Sanzhong; Yu, Shan; Somerville, Ian D.; Liu, Xin; Zhao, Shujuan; Dai, Liming

    2014-07-01

    Tectonic migration is a common geological process of basin formation and evolution. However, little is known about tectonic migration in the western Pacific margins. This paper focuses on the representative Cenozoic basins of East China and its surrounding seas in the western Pacific domain to discuss the phenomenon of tectonic jumping in Cenozoic basins, based on structural data from the Bohai Bay Basin, the South Yellow Sea Basin, the East China Sea Shelf Basin, and the South China Sea Continental Shelf Basin. The western Pacific active continental margin is the eastern margin of a global convergent system involving the Eurasian Plate, the Pacific Plate, and the Indian Plate. Under the combined effects of the India-Eurasia collision and retrogressive or roll-back subduction of the Pacific Plate, the western Pacific active continental margin had a wide basin-arc-trench system which migrated or ‘jumped’ eastward and further oceanward. This migration and jumping is characterized by progressive eastward younging of faulting, sedimentation, and subsidence within the basins. Owing to the tectonic migration, the geological conditions associated with hydrocarbon and gashydrate accumulation in the Cenozoic basins of East China and its adjacent seas also become progressively younger from west to east, showing eastward younging in the generation time of reservoirs, seals, traps, accumulations and preservation of hydrocarbon and gashydrate. Such a spatio-temporal distribution of Cenozoic hydrocarbon and gashydrate is significant for the oil, gas and gashydrate exploration in the East Asian Continental Margin. Finally, this study discusses the mechanism of Cenozoic intrabasinal and interbasinal tectonic migration in terms of interplate, intraplate and underplating processes. The migration or jumping regimes of three separate or interrelated events: (1) tectonism-magmatism, (2) basin formation, and (3) hydrocarbon-gashydrate accumulation are the combined effects of the

  20. Lost Terranes of Zealandia: possible development of late Paleozoic and early Mesozoic sedimentary basins at the southwest Pacific margin of Gondwanaland, and their destination as terranes in southern South America Terrenos perdidos de Zealandia: posible desarrollo de cuencas sedimentarias del Paleozoico tardío y Mesozoico temprano en el margen suroccidental del Pacífico de Gondwana y su destino como terrenos en el sur de América del Sur

    Directory of Open Access Journals (Sweden)

    Christopher J Adams

    2010-07-01

    Full Text Available Latest Precambrian to Ordovician metasedimentary successions and Cambrian-Ordovician and Devonian-Carboniferous granitoids form the major part of the basement of southern Zealandia and adjacent sectors of Antarctica and southeast Australia. Uplift/cooling ages of these rocks, and local Devonian shallow-water cover sequences suggest that final consolidation of the basement occurred through Late Paleozoic time. A necessary consequence of this process would have been contemporaneous erosion and the substantial development of marine sedimentary basins at the Pacific margin of Zealandia. These are found nowhere at the present day, suggesting that the basins have been lost by tectonic erosion, perhaps in a margin-parallel dextral translation similar to late Paleozoic-Mesozoic suspect terranes of New Zealand. Aprobable detrital zircon age pattern is assembled for these lost Zealandia sediments, and then compared with those of pre-Jurassic (probable Triassic to Devonian metasedimentary rocks in the Chilean archipelago. Significant Mesoproterozoic, latest Neoproterozoic-Cambrian and Devonian-Carboniferous detrital zircon age components are common to both, thus supporting a possible Chilean terrane destination for these 'lost terranes of Zealandia'.Las sucesiones metasedimentarias del Precámbrico tardío al Ordovícico y granitoides del Cámbrico-Ordovícico y Devónico-Carbonífero constituyen la mayor parte del basamento del sur de Zealandia y sectores adyacentes de la Antartica y el sudeste de Australia. Las edades de enfriamiento/alzamiento de estas rocas y la cobertura local de secuencias de aguas someras del Devónico, sugieren que la consolidación definitiva del basamento se produjo durante el Paleozoico tardío. Una consecuencia necesaria de este proceso habría sido la erosion contemporánea y el desarrollo sustancial de cuencas sedimentarias marinas en el margen del Pacífico de Zealandia. Estas no se encuentran en ninguna parte en la

  1. Ventilation changes in the northeast Pacific during the last deglaciation

    Science.gov (United States)

    VanGeen, A.; Fairbanks, R.G.; Dartnell, P.; McGann, M.; Gardner, J.V.; Kashgarian, Michaele

    1996-01-01

    Under present climate conditions, convection at high latitudes of the North Pacific is restricted to shallower depths than in the North Atlantic. To what extent this asymmetry between the two ocean basins was maintained over the past 20 kyr is poorly known because there are few unambiguous proxy records of ventilation from the North Pacific. We present new data for two sediment cores from the California margin at 800 and 1600 m depth to argue that the depth of ventilation shifted repeatedly in the northeast Pacific over the course of deglaciation. The evidence includes benthic foraminiferal Cd/Ca, 18O/16O, and 13C/12C data as ell as radiocarbon age differences between benthic and planktonic foraminifera. A number of features in the shallower of the two cores, including an interval of laminated sediments, are consistent with changes in ventilation over the past 20 kyr suggested by alternations between laminated and bioturbated sediments in the Santa Barbara Basin and the Gulf of California [Keigwin and Jones, 1990; Kennett and Ingram, 1995; Behl and Kennett, 1996]. Data from the deeper of the two California margin cores suggest that during times of reduced ventilation at 800 m, ventilation was enhanced at 1600 m depth, and vice versa. This pronounced depth dependence of ventilation needs to be taken into account when exploring potential teleconnections between the North Pacific and the North Atlantic.

  2. Artificial Radionuclides Database in the Pacific Ocean: HAM Database

    Directory of Open Access Journals (Sweden)

    Michio Aoyama

    2004-01-01

    Full Text Available The database “Historical Artificial Radionuclides in the Pacific Ocean and its Marginal Seas”, or HAM database, has been created. The database includes 90Sr, 137Cs, and 239,240Pu concentration data from the seawater of the Pacific Ocean and its marginal seas with some measurements from the sea surface to the bottom. The data in the HAM database were collected from about 90 literature citations, which include published papers; annual reports by the Hydrographic Department, Maritime Safety Agency, Japan; and unpublished data provided by individuals. The data of concentrations of 90Sr, 137Cs, and 239,240Pu have been accumulating since 1957–1998. The present HAM database includes 7737 records for 137Cs concentration data, 3972 records for 90Sr concentration data, and 2666 records for 239,240Pu concentration data. The spatial variation of sampling stations in the HAM database is heterogeneous, namely, more than 80% of the data for each radionuclide is from the Pacific Ocean and the Sea of Japan, while a relatively small portion of data is from the South Pacific. This HAM database will allow us to use these radionuclides as significant chemical tracers for oceanographic study as well as the assessment of environmental affects of anthropogenic radionuclides for these 5 decades. Furthermore, these radionuclides can be used to verify the oceanic general circulation models in the time scale of several decades.

  3. Persistence of deeply sourced iron in the Pacific Ocean.

    Science.gov (United States)

    Horner, Tristan J; Williams, Helen M; Hein, James R; Saito, Mak A; Burton, Kevin W; Halliday, Alex N; Nielsen, Sune G

    2015-02-03

    Biological carbon fixation is limited by the supply of Fe in vast regions of the global ocean. Dissolved Fe in seawater is primarily sourced from continental mineral dust, submarine hydrothermalism, and sediment dissolution along continental margins. However, the relative contributions of these three sources to the Fe budget of the open ocean remains contentious. By exploiting the Fe stable isotopic fingerprints of these sources, it is possible to trace distinct Fe pools through marine environments, and through time using sedimentary records. We present a reconstruction of deep-sea Fe isotopic compositions from a Pacific Fe-Mn crust spanning the past 76 My. We find that there have been large and systematic changes in the Fe isotopic composition of seawater over the Cenozoic that reflect the influence of several, distinct Fe sources to the central Pacific Ocean. Given that deeply sourced Fe from hydrothermalism and marginal sediment dissolution exhibit the largest Fe isotopic variations in modern oceanic settings, the record requires that these deep Fe sources have exerted a major control over the Fe inventory of the Pacific for the past 76 My. The persistence of deeply sourced Fe in the Pacific Ocean illustrates that multiple sources contribute to the total Fe budget of the ocean and highlights the importance of oceanic circulation in determining if deeply sourced Fe is ever ventilated at the surface.

  4. Pacific tectonics: Eastern-Pacific "stationarity" of EPR and causative association with Equator

    Science.gov (United States)

    Bostrom, R. C.

    2003-04-01

    The fundamentals of present-day Pacific tectonics are observed to be: its N/S mirror-symmetry about the Equator, displayed by the major transforms; its E/W asymmetry, represented by the western motion of the world's largest plate, originating in the eastern Equatorial Pacific; and correspondingly, development of the globally most voluminous subduction, at the western Pacific margin. The configuration seen at present is maintained at a fundamental level. The maximum in convective upwelling develops as coalescing plumes in the Galapagos region in the eastern Pacific. This has been found (Lonsdale 1988; McGuire and Hilde 2002; Chen and Lin 2002) to produce steady westward propagation of the Nazca/Cocos axis. Continually renewed, it determines the orientation and locus of a quasi-stationary EPR, centered on the Equator. Magnetic dating of boundaries in satellite gravity images records the Cenozoic history of the EPR, namely re-orientation in consequence of slow counter-clockwise re-orientation of the Equator. Relative to the present, during Maastrichtian times both Equator and plate motion were aligned WNW, recorded paleomagnetically and by features in the western, older part of the Pacific crust. Material subducted at that time accumulated principally beneath the SE Asia margin. Its slow heating is believed to play a role in the deep-seated activity and back-arc spreading associated with latter-day convergence in that region. The mechanism primarily responsible for the Pacific regime may be that mantle convection is not immune, as is generally tacitly supposed, to the minute westward tilt (c. 0.36°) under which it takes place. The latter, now astronomically quantifiable without tidal identification, represents the attraction component of water and solid-Earth masses which averaged over unit day lags the direction of purely geocentric g. Under gravity minutely E/W asymmetric, convection as always promoting the most efficient dissipative configuration, favors

  5. Epidemiology of Meningococcal Disease in Northeastern Africa

    Science.gov (United States)

    1987-01-01

    major public health problem in the Nile Valley from Alexandria, Egypt to the southern regions of the Sudan. Like the disease in the sub-Saharan region...and the Sudan is unique in that it occurs in the large urban areas of Cairo and Khartoum with relatively minor variations in disease incidence...r LIE) DTIC , . [iE LE CTE ili D PUBLICATION REPORT 1514 33/88 EPIDEMIOLOGY OF MENINGOCOCCAL DISEASE IN NORTHEASTERN AFRICA BY John E. Sippel, and

  6. Periodontal conditions of elders in Northeastern Brazil

    OpenAIRE

    Maria Vieira de Lima Saintrain; Maria Daucirlene Costa Aquino

    2015-01-01

    Objective: To evaluate the periodontal conditions of elderly patients assisted in a Specialized Dentistry Center in Northeastern of Brazil. Methods: Quantitative and cross-sectional study conducted with 152 elders. It was used a questionnaire to get information about socio-demographic aspects (age, sex, gender, income, and education), general healthand periodontal clinical examination based on the Communitarian Periodontal Index (CPI), an indicator recommended by the World Health Organization...

  7. 12 CFR 220.4 - Margin account.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Margin account. 220.4 Section 220.4 Banks and... BROKERS AND DEALERS (REGULATION T) § 220.4 Margin account. (a) Margin transactions. (1) All transactions not specifically authorized for inclusion in another account shall be recorded in the margin account...

  8. 17 CFR 41.45 - Required margin.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Required margin. 41.45 Section... PRODUCTS Customer Accounts and Margin Requirements § 41.45 Required margin. (a) Applicability. Each security futures intermediary shall determine the required margin for the security futures and related...

  9. Sea star Henricia spiculifera (Clark, 1901 in the northwestern Pacific: one species or three?

    Directory of Open Access Journals (Sweden)

    Anton Chichvarkhin

    2017-06-01

    Full Text Available Three species of the sea stars are reported from the waters of the northwestern Pacific. These species were referred by earlier authors as Henricia spiculifera or H. leviuscula spiculifera. Two of them, H. lineata and H. uluudax, were recently described from the Aleutian Islands. These species are reported for the first time from the western Pacific (southeastern Kamchatka shore, Commander Islands, and the northern Kurile Islands. The third species, H. olga sp. n. is herein described from the northern Sea of Japan. It is very likely that similar sea stars recorded in Yellow Sea and the southern Kurile Islands belong to H. olga sp. n. These three species are a part of a phylogenetic clade within the subgenus Setihenricia, which also includes H. sanguinolenta, H. multispina, and several undescribed species occurring in the northeastern Pacific.

  10. Preliminary study on the characteristics of aerosols over the western pacific ocean

    International Nuclear Information System (INIS)

    Hu Zhaohui; Liu Pingsheng; Liu Shijie; Yao Ying; Feng Guohua

    1996-01-01

    Marine aerosol from the western Pacific were collected by two types of samplers during a cruise from Nanhai of China through the west of Philippines to the equatorial and to the north-eastern of Solomon Archipelago. Collected samples were analyzed by PIXE. The data gave aerosol characteristics over the western Pacific, including concentrations, enrichments and mass size distributions of detected elements, and possible sources of these elements were specially researched. The result indicates that Al, Si and Fe were associated with soil particles; Cl, Br, K, Ca and S showed characteristics of the sea-salt origin; and Cu, Zn, and Pb were due to pollution from long-range transport of continental aerosol. We have also made comparison with data obtained in earlier studies over other regions of the Pacific. (author)

  11. Eastern Pacific Ocean Conference

    Science.gov (United States)

    The promotion of interaction among investigators of all oceanographic disciplines studying the eastern Pacific Ocean was the goal of the 1990 Eastern Pacific Ocean Conference (EPOC), held October 17-19 on the snow-covered slopes of Mt. Hood, Oreg. Thirty oceanographers representing all disciplines attended.Dick Barber, Duke University Marine Lab, Beaufort, N.C., chaired a session on the eastern equatorial Pacific Ocean, emphasizing issues related to biological activity. Steve Ramp of the Naval Postgraduate School in Montery, Calif., chaired a session on recent results from northern and central California experiments. On October 19, following an early morning earthquake, a business meeting and discussions regarding a collaboration in future experiments were held.

  12. Pacific Coastal Salmon Recovery Fund

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Congress established the Pacific Coastal Salmon Recovery Fund (PCSRF) to monitor the restoration and conservation of Pacific salmon and steelhead populations and...

  13. Tectonic Evolution of the Rift Basins in the Northeastern Brazilian Region

    Science.gov (United States)

    Mohriak, Webster U.; Bassetto, Marcelo; Vieira, Ines S.

    The transition from onshore failed rifts to offshore sedimentary basins along divergent continental margins is discussed on the basis of a regional, multidisciplinary integration of deep seismic reflection profiling, potential fied methods, geological data, and tectonic analysis. The following themes are addressed: a) the geologic evolution of the onshore and offshore rift systems of the Brazilian northeastern margin; b) the potential field methods response to the deep crustal structures; c) the seismic expression of major structural features in the rifts and within the continental and oceanic crusts; d) a possible geodynamic model for the evolution of the rift system; and e) analogies with a number of failed rifts and passive margin systems in the North Atlantic. The sedimentary basins in northeastern Brazil include a series of asymmetric grabens, such as the onshore Recôncavo-Tucano-Jatobá rift system (RTJ) and the offshore Jacuípe-Sergipe-Alagoas basins (JSA). Pre-rift sediments include Paleozoic to Jurassic/Early Cretaceous sediments deposited above a basement that includes Archean rocks to Late Proterozoic metasediments. The main rift phase (Neocomian to Barremian) terminated in the onshore rifts with fluvial deposits above a major regional unconformity. No further sedimentation is observed in the Recôncavo and Tucano basins, in a marked contrast to the geodynamic evolution of the Sergipe Basin, which is characterized by renewed phases of basement-involved faulting from Aptian to Early Albian, followed by a thermal phase of subsidence. The overall picture of two branches of a rift system, with different geodynamic evolution following the inception of oceanic crust, may be associated with a regional lithospheric extension during the Neocomian, first distributed over a wide region, and subsequently, focussing along a deeper mantle weak zone, local of a later plate rupture.

  14. 210Pb and 210Po as tracers of particle transport mechanisms on continental margins

    International Nuclear Information System (INIS)

    Radakovitch, O.; Heussner, S.; Biscaye, P.; Abassi, A.

    1997-01-01

    The natural radionuclides 210 Po and 210 Pb, members of the 238 U decay chain, are particularly helpful to the understanding of particle transport processes in the ocean. These isotopes were analysed on sediment trap particles collected during 3 one-year experiments on continental margins. In the Bay of Biscay (Northeastern Atlantic) and in the Gulf of Lion (Northwestern Mediterranean Sea) both as part of the French ECOMARGE programme, and in the Middle Atlantic Bight (Northwestern Atlantic) as part of the SEEP programme. They yielded great insights into scenarios of particle transfer at each site, mainly based on the spatial and temporal distribution of 210 Pb particulate concentrations and fluxes. (author)

  15. Distribution patterns of Recent planktonic foraminifera in surface sediments of the western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.

    derived from organisms living as benthos on the seafloor, and shells of organisms which once had lived as plankton in the surface waters (Diester-Haass et al., 1973). Thus the sedi- ments of continental margins show features typical 0025... surface waters contrast sharply with low salinity waters along the south Indian coast and in the Bay of Bengal (Fig. 3A). The North Equato- rial Current sets-in during the northeastern mon- soon period and it penetrates into the southern Arabian Sea...

  16. Texas curve margin of safety.

    Science.gov (United States)

    2013-01-01

    This software can be used to assist with the assessment of margin of safety for a horizontal curve. It is intended for use by engineers and technicians responsible for safety analysis or management of rural highway pavement or traffic control devices...

  17. Ethnographies of marginality [Review article

    NARCIS (Netherlands)

    Beuving, J.J.

    2016-01-01

    Africanist discourse today displays a strong, widespread and growing sense of optimism about Africa's economic future. After decades of decline and stagnation in which Africa found itself reduced to the margins of the global economic stage, upbeat Afro-optimism seems fully justified. One only needs

  18. Marginality and Variability in Esperanto.

    Science.gov (United States)

    Brent, Edmund

    This paper discusses Esperanto as a planned language and refutes three myths connected to it, namely, that Esperanto is achronical, atopical, and apragmatic. The focus here is on a synchronic analysis. Synchronic variability is studied with reference to the structuralist determination of "marginality" and the dynamic linguistic…

  19. Profit margins in Japanese retailing

    NARCIS (Netherlands)

    J.C.A. Potjes; A.R. Thurik (Roy)

    1993-01-01

    textabstractUsing a rich data source, we explain differences and developments in profit margins of medium-sized stores in Japan. We conclude that the protected environment enables the retailer to pass on all operating costs to the customers and to obtain a relatively high basic income. High service

  20. Modelling passive margin sequence stratigraphy

    Science.gov (United States)

    Steckler, M.S.; Reynolds, D.; Coakley, B.; Swift, B.A.; Jarrard, R.D.

    1993-01-01

    We have modelled stratigraphic sequences to aid in deciphering the sedimentary response to sea-level change. Sequence geometry is found to be most sensitive to sea level, but other factors, including subsidence rate and sediment supply, can produce similar changes. Sediment loading and compaction also play a major role in generating accommodation, a factor often neglected in sequence-stratigraphic models. All of these parameters can control whether a type 1 or type 2 sequence boundary is produced. The models indicate that variations in margin characteristics produce systematic shifts in sequence boundary timing and systems tract distribution. The timing of the sequence boundary formation and systems tracts may differ by up to one-half of a sea-level cycle. Thus correlative sequence boundaries will not be synchronous. While rates of sea-level change may exceed the rate of thermal subsidence, isostasy and compaction may amplify the rate of total subsidence to several times greater than the thermal subsidence. Thus, total subsidence does not vary uniformly across the margin since it is modified by the sediment load. The amplitude of sea-level changes cannot be determined accurately without accounting for the major processes that affect sediment accumulation. Backstripping of a seismic line on the New Jersey margin is used to reconstruct continental margin geometry. The reconstructions show that the pre-existing ramp-margin geometry, rather than sea level, controls clinoform heights and slopes and sedimentary bypass. Backstripping also reveals progressive deformation of sequences due to compaction. Further work is still needed to understand quantitatively the role of sea level and the tectonic and sedimentary processes controlling sequence formation and influencing sequence architecture.

  1. Fiji in the South Pacific.

    Science.gov (United States)

    Scott, Rosalind; Semaan, Leslie

    This text introduces Fiji and other island nations located in the Pacific, the world's largest ocean. Cut off from the world by vast expanses of water, these people developed a unique culture. Contents include: Teacher Overview, Geography of the South Pacific Islands, History of the South Pacific, Fiji, Traditional Village Life, Yaquna Ceremony,…

  2. Revised reconstructions of the Late Cretaceous to recent history of the Pacific basin

    Science.gov (United States)

    Wright, N.; Seton, M.; Williams, S.; Müller, D.

    2013-12-01

    The tectonic evolution of the Pacific basin since the Late Cretaceous involves a number of major plate reorganisations, including multiple fragmentations of the Farallon plate and the formation of the Vancouver, Nazca and Cocos plates, and the incorporation of the Bellingshausen plate into the Antarctic plate. However, many regional plate kinematic models of the northeast and southeast Pacific are based on data derived before the availability of high-resolution satellite altimetry and accurate global positioning system (GPS) navigation, causing inconsistencies in these models. Such inconsistencies arise from differences in previous magnetic anomaly interpretations and fracture zone identifications from satellite-derived gravity anomalies. Discrepancies in published models of the Nazca-Pacific, Vancouver-Pacific and Farallon-Pacific spreading history results have implications for modelling the convergence history along the South American and North American margins within global plate models, influencing the variations in age, location and geometry of plates at subduction zones. We refine reconstructions of the seafloor spreading history of the south (Pacific, Antarctic, and Bellingshausen plates), southeast (Nazca, Farallon and Pacific plates) and northeast (Vancouver, Farallon and Pacific plates) Pacific basin from the Late Cretaceous (83.5 Ma) to present-day, based on a synthesis of marine magnetic anomaly picks and fracture zone identifications from satellite-derived gravity anomalies. We calculate rotations and uncertainties for plate pairs based on Hellinger's (1981) best fitting criteria. We divide the Farallon plate into two segments: the northern segment (Farallon plate) and southern segment (';Pre-Nazca' plate), and reconstruct separate spreading histories for each segment relative to the Pacific plate, and find large differences in our ';Pre-Nazca'-Pacific history compared to published models for this area. We subsequently investigate the difference in the

  3. Trends in solar radiation in NCEP/NCAR database and measurements in northeastern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Vicente de Paulo Rodrigues da; Silva, Roberta Araujo e; Cavalcanti, Enilson Palmeira; Braga, Celia Campos; Azevedo, Pedro Vieira de; Pereira, Emerson Ricardo Rodrigues [Federal University of Campina Grande/Center of Technology and Natural Resources/Academic Unity of Atmospheric Sciences, Av. Aprigio Veloso, 882, Bodocongo, 58109 970, Campina Grande, PB (Brazil); Singh, Vijay P. [Dept. of Biological and Agricultural Engineering, Texas A and M Univ., TX 77843-2117 (United States)

    2010-10-15

    The database from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) re-analysis project available for the period from 1948 to 2009 was used for obtaining long-term solar radiation for northeastern Brazil. Measurements of global solar radiation (R{sub s}) from data collection platform (DCP) for four climatic zones of northeastern Brazil were compared to the re-analysis data. Applying cluster analysis to R{sub s} from database, homogeneous sub-regions in northeastern Brazil were determined. Long times series of R{sub s} and sunshine duration measurements data for two sites, Petrolina (09 09'S, 40 22'W) and Juazeiro (09 24'S, 40 26'W), exceeding 30 years, were analyzed. In order to exclude the decadal variations which are linked to the Pacific Decadal Oscillation, high-frequency cycles in the solar radiation and sunshine duration time series were eliminated by using a 14-year moving average, and the Mann-Kendall test was employed to assess the long-term variability of re-analysis and measured solar radiation. This study provides an overview of the decrease in solar radiation in a large area, which can be attributed to the global dimming effect. The global solar radiation obtained from the NCEP/NCAR re-analysis data overestimate that obtained from DCP measurements by 1.6% to 18.6%. Results show that there is a notable symmetry between R{sub s} from the re-analysis data and sunshine duration measurements. (author)

  4. Pacific Island Pharmacovigilance

    DEFF Research Database (Denmark)

    McEwen, John; Vestergaard, Lasse S.; Sanburg, Amanda L C

    2016-01-01

    Many Pacific Island countries (PICs) are recipients of funding support from the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund). However, most of these countries cannot be expected to meet Global Fund and World Health Organization (WHO) minimum requirements for a functioning...

  5. Post-rift volcanic structures of the Pernambuco Plateau, northeastern Brazil

    Science.gov (United States)

    Buarque, Bruno V.; Barbosa, José A.; Magalhães, José R. G.; Cruz Oliveira, Jefferson T.; Filho, Osvaldo J. Correia

    2016-10-01

    The Pernambuco marginal basin is located on the eastern continental margin of northeastern Brazil, covers an area of 20,800 km2, and represents one of the most prominent frontiers for deep water oil and gas exploration off the Brazilian coast. The onshore region of this basin was highly affected by extrusive and intrusive magmatism during the Upper Albian, and the relation of that event with the volcanic structures observed in the offshore sector has not been thoroughly characterized to date. This study aims to characterize the major extrusive and intrusive volcanic structures of the offshore portion of this basin, which is dominated by the Pernambuco Plateau, and its stratigraphic relations. A set of 143 2D multichannel seismic sections that cover the Pernambuco Plateau region are used to interpret the major tectono-stratigraphic sequences and describe the distribution of volcanoes, sills, vent complexes and related volcaniclastic sequences. The interpretations are supported by aeromagnetic and gravimetric geophysical surveys. Volcanoes are classified into two groups that differ in terms of their morphology: shield-like structures and cone-shaped volcanic structures. Sill intrusions are mainly identified beneath the volcanic structures and are characterized by high-amplitude reflectors with short extensions and abrupt terminations. Volcaniclastic sequences are found adjacent to the volcanoes and are characterized by high-amplitude, disrupted reflections with local chaotic configurations. Vent complexes are classified on the basis of their morphologies as either eye-shaped or crater-shaped. The volcanic features identified within the available seismic dataset are concentrated in two main areas: in the centre of the plateau and near its northeastern border. These two regions are host basement outer highs and are surrounded by hyper-extended continental crust, which forms the plateau itself. The extrusive and intrusive features described in the offshore region were

  6. The Margins of Medieval Manuscripts

    Directory of Open Access Journals (Sweden)

    Nataša Kavčič

    2011-12-01

    Full Text Available Shortly after the mid-thirteenth century, various images began to fill the margins in both religious and secular texts. Many factors influenced the emergence of this type of manuscript decoration, but it has generally been attributed to the revived interest in nature and the Gothic inclination for humorous and anecdotic detail. After highlighting other possible reasons for the occurrence of marginal illumination, this paper introduces two manuscripts from the Archiepiscopal Archives in Ljubljana. The manuscripts show numerous facial drawings affixed to some of the letters. This article addresses how to interpret such drawings and stresses that they do not necessarily function as symbolic images or images with any specific didactic value. Quite the opposite, these drawings seem not to have any meaning and are oft en merely indications of an illuminator’s sense of humor. Because of their exaggerated facial expressions, these drawings could be perceived as the true predecessors of modern caricature.

  7. Margins related to equipment design

    International Nuclear Information System (INIS)

    Devos, J.

    1994-01-01

    Safety margins related to design of reactor equipment are defined according to safety regulations. Advanced best estimate methods are proposed including some examples which were computed and compared to experimental results. Best estimate methods require greater computation effort and more material data but give better variable accuracy and need careful experimental validation. Simplified methods compared to the previous are less sensitive to material data, sometimes are more accurate but very long to elaborate

  8. Sources and processes affecting the distribution of dissolved Nd isotopes and concentrations in the West Pacific

    Science.gov (United States)

    Behrens, Melanie K.; Pahnke, Katharina; Schnetger, Bernhard; Brumsack, Hans-Jürgen

    2018-02-01

    In the Atlantic, where deep circulation is vigorous, the dissolved neodymium (Nd) isotopic composition (expressed as ɛNd) is largely controlled by water mass mixing. In contrast, the factors influencing the ɛNd distribution in the Pacific, marked by sluggish circulation, is not clear yet. Indication for regional overprints in the Pacific is given based on its bordering volcanic islands. Our study aims to clarify the impact and relative importance of different Nd sources (rivers, volcanic islands), vertical (bio)geochemical processes and lateral water mass transport in controlling dissolved ɛNd and Nd concentration ([Nd]) distributions in the West Pacific between South Korea and Fiji. We find indication for unradiogenic continental input from South Korean and Chinese rivers to the East China Sea. In the tropical West Pacific, volcanic islands supply Nd to surface and subsurface waters and modify their ɛNd to radiogenic values of up to +0.7. These radiogenic signatures allow detailed tracing of currents flowing to the east and differentiation from westward currents with open ocean Pacific ɛNd composition in the complex tropical Pacific zonal current system. Modified radiogenic ɛNd of West Pacific intermediate to bottom waters upstream or within our section also indicates non-conservative behavior of ɛNd due to boundary exchange at volcanic island margins, submarine ridges, and with hydrothermal particles. Only subsurface to deep waters (3000 m) in the open Northwest Pacific show conservative behavior of ɛNd. In contrast, we find a striking correlation of extremely low (down to 2.77 pmol/kg Nd) and laterally constant [Nd] with the high-salinity North and South Pacific Tropical Water, indicating lateral transport of preformed [Nd] from the North and South Pacific subtropical gyres into the study area. This observation also explains the previously observed low subsurface [Nd] in the tropical West Pacific. Similarly, Western South Pacific Central Water, Antarctic

  9. Stress Orientations in a Locked Subduction Zone at the Southern Hikurangi Margin, New Zealand

    Science.gov (United States)

    Evanzia, Dominic; Wilson, Thomas; Savage, Martha K.; Lamb, Simon; Hirschberg, Hamish

    2017-10-01

    We analyze the orientation of the stress field in the southern Hikurangi subduction zone, New Zealand, using focal mechanism inversions, S wave splitting fast directions, and gravitational stresses. Here the oceanic Pacific plate is being obliquely subducted beneath the continental Australian plate in the New Zealand plate boundary zone. The study makes use of 399 earthquakes for focal mechanism inversion and 425 earthquakes for shear wave splitting analysis, located with a network of seismic stations spanning southern North Island. We distinguish between stresses in the Pacific plate (from focal mechanism inversion) and Australian plate (from S wave fast directions) and gravitational stresses, in three regions: Western, Central Basin, and Eastern. In the Western region, the principal axis of horizontal compression (SHmax) is oriented NE-SW, parallel to the margin, in the upper Australian and lower Pacific plate. In the Central Basin, SHmax in the Australian plate is oriented NW-SE, perpendicular to the margin; in the lower subducting Pacific plate SHmax is oriented NE-SW. In the Eastern region, SHmax is oriented NE-SW in the upper plate, while in the lower plate there is a change in orientation to NNW-SSE. We interpret the stress orientations of the lower plate in the Western and Central Basin regions as a consequence of bending of the subducting plate. Sources of upper Australian plate stresses are likely to be bending stresses, gravitational stresses, and tectonic loading, with differing relative magnitudes across the study area.

  10. Riparian communities associated with pacific northwest headwater streams: assemblages, processes, and uniqueness.

    Science.gov (United States)

    John S. Richardson; Robert J. Naiman; Frederick J. Swanson; David E. Hibbs

    2005-01-01

    Riparian areas of large streams provide important habitat to many species and control many instream processes - but is the same true for the margins of small streams? This review considers riparian areas alongside small streams in forested, mountainous areas of the Pacific Northwest and asks if there are fundamental ecological differences from larger streams and from...

  11. WATER-ECONOMIC PROBLEMS IN NORTHEASTERN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Goran Rajovic

    2013-04-01

    Full Text Available The paper discusses the problems of water economic northeastern Montenegro municipalities Berane, Andrijevica and Plav. It points to the problem of exploitation of water, protection of water and water protection. Within exploit water resources, the possibilities of water supply of population and industry, water supply, agriculture, hydropower exploitation, tourism and recreational use. Current and future use of water resources considered GeoScape, requires a new approach, which should be in accordance with the concept of active protection of the environment.

  12. Crustal structure and inferred extension mode in the northern margin of the South China Sea

    Science.gov (United States)

    Gao, J.; Wu, S.; McIntosh, K. D.; Mi, L.; Spence, G.

    2016-12-01

    Combining multi-channel seismic reflection and satellite gravity data, this study has investigated the crustal structure and magmatic activities of the northern South China Sea (SCS) margin. Results show that a broad continent-ocean transition zone (COT) with more than 140 km wide is characterized by extensive igneous intrusion/extrusion and hyper-extended continental crust in the northeastern SCS margin, a broader COT with 220-265 km wide is characterized by crustal thinning, rift depression, structural highs with igneous rock and perhaps a volcanic zone or a zone of tilted fault blocks at the distal edge in the mid-northern SCS margin, and a narrow COT with 65 km wide bounded seawards by a volcanic buried seamount is characterized by extremely hyper-extended continental crust in the northwestern SCS margin, where the remnant crust with less than 3 km thick is bounded by basin-bounding faults corresponding to an aborted rift below the Xisha Trough with a sub-parallel fossil ridge in the adjacent Northwest Sub-basin. Results from gravity modeling and seismic refraction data show that a high velocity layer (HVL) is present in the outer shelf and slope below extended continental crust in the eastern portion of the northern SCS margin and is thickest (up to 10 km) in the Dongsha Uplift where the HVL gradually thins to east and west below the lower slope and finally terminates at the Manila Trench and Baiyun sag of the Pearl River Mouth Basin. The magmatic intrusions/extrusions and HVL may be related to partial melting caused by decompression of passive, upwelling asthenosphere which resulted primarily in post-rifting underplating and magmatic emplacement or modification of the crust. The northern SCS margin is closer to those of the magma-poor margins than those of volcanic margins, but the aborted rift near the northwestern continental margin shows that there may be no obvious detachment fault like that in the Iberia-Newfoundland type margin. The symmetric aborted

  13. Amphidromy Links a Newly Documented Fish Community of Continental Australian Streams, to Oceanic Islands of the West Pacific

    Science.gov (United States)

    Thuesen, Paul A.; Ebner, Brendan C.; Larson, Helen; Keith, Philippe; Silcock, Rebecca M.; Prince, Jason; Russell, David J.

    2011-01-01

    Background Indo-Pacific high island streams experience extreme hydrological variation, and are characterised by freshwater fish species with an amphidromous life history. Amphidromy is a likely adaptation for colonisation of island streams following stochastic events that lead to local extirpation. In the Wet Tropics of north-eastern Australia, steep coastal mountain streams share similar physical characteristics to island systems. These streams are poorly surveyed, but may provide suitable habitat for amphidromous species. However, due to their ephemeral nature, common non-diadromous freshwater species of continental Australia are unlikely to persist. Consequently, we hypothesise that coastal Wet Tropics streams are faunally more similar, to distant Pacific island communities, than to nearby faunas of large continental rivers. Methods/Principal Findings Surveys of coastal Wet Tropics streams recorded 26 species, 10 of which are first records for Australia, with three species undescribed. This fish community is unique in an Australian context in that it contains mostly amphidromous species, including sicydiine gobies of the genera Sicyopterus, Sicyopus, Smilosicyopus and Stiphodon. Species presence/absence data of coastal Wet Tropics streams were compared to both Wet Tropics river networks and Pacific island faunas. ANOSIM indicated the fish fauna of north-eastern Australian coastal streams were more similar to distant Pacific islands (R = 0.76), than to nearby continental rivers (R = 0.98). Main Conclusions/Significance Coastal Wet Tropics streams are faunally more similar to distant Pacific islands (79% of species shared), than to nearby continental fauna due to two factors. First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers. Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics. The evolutionary and

  14. Amphidromy links a newly documented fish community of continental Australian streams, to oceanic islands of the west Pacific.

    Directory of Open Access Journals (Sweden)

    Paul A Thuesen

    Full Text Available BACKGROUND: Indo-Pacific high island streams experience extreme hydrological variation, and are characterised by freshwater fish species with an amphidromous life history. Amphidromy is a likely adaptation for colonisation of island streams following stochastic events that lead to local extirpation. In the Wet Tropics of north-eastern Australia, steep coastal mountain streams share similar physical characteristics to island systems. These streams are poorly surveyed, but may provide suitable habitat for amphidromous species. However, due to their ephemeral nature, common non-diadromous freshwater species of continental Australia are unlikely to persist. Consequently, we hypothesise that coastal Wet Tropics streams are faunally more similar, to distant Pacific island communities, than to nearby faunas of large continental rivers. METHODS/PRINCIPAL FINDINGS: Surveys of coastal Wet Tropics streams recorded 26 species, 10 of which are first records for Australia, with three species undescribed. This fish community is unique in an Australian context in that it contains mostly amphidromous species, including sicydiine gobies of the genera Sicyopterus, Sicyopus, Smilosicyopus and Stiphodon. Species presence/absence data of coastal Wet Tropics streams were compared to both Wet Tropics river networks and Pacific island faunas. ANOSIM indicated the fish fauna of north-eastern Australian coastal streams were more similar to distant Pacific islands (R = 0.76, than to nearby continental rivers (R = 0.98. MAIN CONCLUSIONS/SIGNIFICANCE: Coastal Wet Tropics streams are faunally more similar to distant Pacific islands (79% of species shared, than to nearby continental fauna due to two factors. First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers. Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics

  15. Maternal risk factors for HIV infection in infants in northeastern Brazil.

    Science.gov (United States)

    de Lemos, Lígia M D; Lippi, Joseph; Rutherford, George W; Duarte, Gabriella S; Martins, Nágyla G R; Santos, Victor S; Gurgel, Ricardo Q

    2013-10-01

    While the rate of vertically transmitted HIV infection has fallen in most regions of Brazil, there have been no similar decreases in northern and northeastern Brazil. The objective of this study was to evaluate the risk factors associated with vertical transmission in the state of Sergipe in northeastern Brazil. This was a retrospective cohort study. We recorded clinic and registry data for all HIV-infected pregnant women and exposed children diagnosed in Sergipe from 1990 to 2011. We identified 538 deliveries and 561 HIV-exposed infants (23 sets of twins). One hundred one (18.9%) infants were HIV-infected. In the multivariate analysis, infant antiretroviral prophylaxis was a significant protective factor (adjusted odds ratio (aOR) 0.07, 95% confidence interval (CI) 0.01-0.41, p=0.003). Breastfeeding was marginally associated with an increased odds of perinatal transmission (aOR 4.52, 95% CI 0.78-26.17, p = 0.092). The attributable risk percentage for breastfeeding over the study period was 91.0%. Transmission decreased from 91 per 100 live births before 1997 to 2 per 100 in 2011 following the adoption of the prevention protocol. Transmission declined over the study period. The screening of pregnant women and timely initiation of prophylaxis and therapy are issues that require further attention. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  16. Silenced, Silence, Silent: Motherhood in the Margins

    Science.gov (United States)

    Carpenter, Lorelei; Austin, Helena

    2007-01-01

    This project explores the experiences of women who mother children with ADHD. The authors use the metaphor of the text and the margin. The text is the "motherhood myth" that describes a particular sort of "good" mothering. The margin is the space beyond that text. This marginal space is inhabited by some or all of the mothers they spoke with, some…

  17. 17 CFR 31.18 - Margin calls.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Margin calls. 31.18 Section 31....18 Margin calls. (a) No leverage transaction merchant shall liquidate a leverage contract because of a margin deficiency without effecting personal contact with the leverage customer. If a leverage...

  18. Evaluating drizzle formation parametrization using ship-based observations in the Northeastern Pacific

    Science.gov (United States)

    Chiu, Jui-Yuan Christine; Fielding, Mark; Feingold, Graham; Van Leeuwen, Peter Jan; Hogan, Robin

    2017-04-01

    Drizzle, common in marine boundary-layer clouds, plays a crucial role in the microphysical, thermodynamic and dynamic processes that determine cloud structure and properties. Consequently, our ability to model drizzle has a significant impact on understanding and quantifying cloud feedbacks. However, many global models continue to produce drizzle too frequently by a factor of 1.5-2 at cloud base, and likely too heavily in the marine stratocumulus regime. This common model deficiency clearly calls for stronger observational constraints, but progress has been difficult due to a lack of appropriate coincident cloud/drizzle measurements. The entwined nature of clouds and precipitation also compounds the problem further. The recent Marine Atmospheric Radiation Measurement (ARM) GPCI Investigation of Clouds (MAGIC) campaign, making routine ship-based measurements between Los Angeles and Hawaii in 2013, provides an excellent opportunity to evaluate drizzle formation parameterizations. We will show the observed characteristics of coincident clouds and in-cloud precipitation during the campaign, using a novel retrieval method and combined measurements from cloud radar, lidar and shortwave radiation. More importantly, we will present observational-constrained parametrizations suggested by this dataset, and discuss their differences from existing parametrizations that are based on large eddy simulations.

  19. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia.

    Directory of Open Access Journals (Sweden)

    Benny K K Chan

    Full Text Available The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007 and C. newmani sp. nov.. These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

  20. Climate Fingerprints of The Interdecadal Pacific Oscillation

    Science.gov (United States)

    Dong, Bo

    The Interdecadal Pacific Oscillation (IPO) is a multi-decadal quasi-oscillation seen primarily in tropical and extratropical Pacific sea surface temperatures (SSTs). Interacting with the atmosphere, the IPO has been shown to affect global and regional climate. However, a quantitative global synthesis of the IPO's climate fingerprints and the underlying mechanisms are still lacking. Based on observational and reanalysis data and atmospheric model simulations, this dissertation investigates the IPO's influence on regional climates over the globe, and its interactions with El Nino-Southern Oscillation (ENSO) and global warming. Since 1920, there are two warm (1924-1944 and 1977-1998) and two cold (1945-1976 and 1999-present) IPO phases. The IPO explains more than half of the interdecadal variations in surface air temperature (T) and precipitation (P) over many regions, such as northeastern Australia, southern Africa and the Southwest U.S. Although the IPO's SST pattern is ENSO-like, its influence on remote regional climate (referred to as teleconnection) differs substantially in spatial and seasonal features from those of ENSO's. In addition, the IPO can modulate ENSO's influence on regional T and P by changing the coupling strength between regional T/P and Nino 3.4 index over different IPO phases. Such modulation effect can be explained by changes in the meridional (local Hadley) and zonal (Walker) overturning circulation at low latitudes, and the Pacific North America (PNA)-type Rossby wave train in the extratropics. Composite analyses show that the IPO's modulation of ENSO's teleconnection varies with both IPO and ENSO phases, as the modulation patterns are neither symmetrically opposite between warm and cold IPO phases, nor between El Nino and La Nina events. A set of numerical experiments using the Community Atmosphere Model version 5 (CAM5) forced with different combinations of the IPO- and ENSO-related SST fields further illustrate IPO's asymmetric modulation

  1. The Effect of Afforestation on Soil Moisture Content in Northeastern China.

    Science.gov (United States)

    Yao, Yitong; Wang, Xuhui; Zeng, Zhenzhong; Liu, Yongwen; Peng, Shushi; Zhu, Zaichun; Piao, Shilong

    2016-01-01

    Widespread afforestation programs sequester carbon from the atmosphere and mitigate the rising of atmospheric carbon dioxide (CO2). Meanwhile, afforestation carbon sequestration may cost soil water. However, changes in soil moisture content (SMC) after large-scale afforestation or reforestation have rarely been quantified. In this study, we measured changes in SMC following afforestation using a paired plots method with data from 757 plots in Northeastern China. We found a marginally significant decline in soil moisture content of the top 1-m soil (SMC0-1m) after afforestation (P = 0.08) at the regional scale. The SMC responses to afforestation also vary across species. For example, significant SMC decrease are found for Populus spp. plantations (P effects of afforestation on soil hydrology vary across different regions.

  2. Managing margins through physician engagement.

    Science.gov (United States)

    Sears, Nicholas J

    2012-07-01

    Hospitals should take the following steps as they seek to engage physicians in an enterprisewide effort to effectively manage margins: Consider physicians' daily professional practice requirements and demands for time in balancing patient care and administrative duties. Share detailed transactional supply data with physicians to give them a behind-the-scenes look at the cost of products used for procedures. Institute physician-led management and monitoring of protocol compliance and shifts in utilization to promote clinical support for change. Select a physician champion to provide the framework for managing initiatives with targeted, efficient communication.

  3. Shallow gas in the Iberian continental margin; Gas somero en el margen continental Iberico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gil, S.; Cartelle, V.; Blas, E. de; Carlos, A. de; Diez, R.; Duran, R.; Ferrin, A.; Garcia-Moreiras, I.; Garcia-Garcia, A.; Iglesias, J.; Martinez-Carreno, N.; Munoz Sobrino, C.; Ramirez-Perez, A. M.

    2015-07-01

    The shallow gas reservoirs in marine sediments from the Iberian margin or their escapes can be detected by using direct methods: (1) the measurement of high concentrations of methane or other hydrocarbons in the water column or sediment cores, (2) the identification of chemosynthetic communities and/or authigenic car- bonates in the seafloor, and (3) identification (using underwater videos) of pockmarks or carbonate mounds and mud volcanoes associated with the fluid escapes; or by indirect technical characterization of anomalies in acoustic records such as: (1) the presence of acoustic plumes in echo-sounders records, (2) the identification of acoustic blanking and/or acoustic turbidity in the high resolution seismic records, (3) the interpretation of reflectivity and (4) morphologies of pockmarks or seamounts in sidescan sonar and multibeam echo sounder records. This article is a compilation of acoustic-seismic, sedimentologic and morphologic evidence associated to the presence of shallow gas (accumulations or escapes) that appear in the Iberian margin and hat have been published in various papers. The description is divided into geographical sectors, beginning in the north-eastern end of the Mediterranean margin and ending at the easternmost area of the Cantabrian margin, following a clockwise direction around the Iberian Peninsula. (Author)

  4. A revised kinematic model for the relative motion between Pacific oceanic plates and North America since the Late Cretaceous

    Science.gov (United States)

    Doubrovine, Pavel V.; Tarduno, John A.

    2008-12-01

    The convergence between the Pacific, Farallon, and Kula oceanic plates and the North American plate has provided a driving force for tectonic processes that have shaped the western margin of North America. Yet reconstructions of plate motion in the Pacific basin have traditionally relied on the assumption of fixed hot spots. In the last decade, substantial Cretaceous to Paleogene motion between the Pacific and Atlantic hot spots has been recognized, providing motivation to reevaluate the history of relative motion between Pacific oceanic plates and North America by means of plate circuit reconstructions. This paper presents new kinematic models based on two alternative plate circuits linking the Pacific plate to North America since Late Cretaceous time. When compared to models relying on fixity of Pacific and Indo-Atlantic hot spots, our reconstructions suggest that the Pacific-Kula and Pacific-Farallon ridges were ˜600-1000 km closer to the western margin of North America and hence that the Farallon and Kula plates were smaller in Late Cretaceous to middle Eocene time. These findings cast significant doubt on the viability of a configuration of the Farallon-Kula ridge that juxtaposes the Kula plate with the southern part of the paleo-North American margin during this time interval. The results of our new reconstructions also suggest more oblique convergence between the Farallon (or Kula) plate and North America from the Late Cretaceous to the middle Eocene related to the combination of dominantly northwest motion of the Pacific plate and steady southwest motion of North America. This provides an efficient mechanism for the coast-parallel translation of some accreted terranes of North America. It may also explain the structure of geological units in western North America, such as the Central Belt of the Franciscan Complex, which show a dominant coast-parallel fabric formed during an interval coeval with the episode of oblique convergence.

  5. Modes of sedimentary basin formation in the north-eastern Black Sea

    Science.gov (United States)

    Stephenson, Randell; Starostenko, Vitaly; Sydorenko, Grygoriy; Yegorova, Tamara

    2016-04-01

    The Greater Caucasus and Black Sea sedimentary basins developed in a Mesozoic back-arc setting, the former older than the latter (Jurassic v. Cretaceous). Compressional shortening of the former and accompanying ongoing development of marginal basin depocentres in the north-eastern Black Sea - which is closely tied to the formation of the Crimea-Greater Caucasus orogen - is a Cenozoic phenomenon, starting in the Eocene and proceeding until the present day. Recently, the sedimentary basin/crust/lithosphere geometry of the study area has been characterised across a range of scales using regional seismic reflection profiling, long-offset refraction/wide-angle reflection profiling and local earthquake tomography. These provide a new integrated image of the present-day crustal structure and sedimentary basin architecture of the northern margin of the eastern Black Sea, north across the Azov Sea and provide evidence of the deeper expression of sedimentary basins and the processes controlling the geometry of their inversion during the Cenozoic. It is inferred that the Greater Caucasus paleo-Basin, lying stratigraphically below the Black Sea and younger sedimentary successions, extends further to the west than previously known. This basin has significant thickness in the area between the Azov and Black seas and probably forms the deeper core of the Crimea-Caucasus inversion zone. The Crimea-Greater Caucasus orogenic belt is the expression of "basin inversion" of the Jurassic Greater Caucasus paleo-Basin, the degree of inversion of which varies along strike. The Greater Caucasus foredeep basins - Indolo-Kuban and Sorokin-Tuapse troughs -represent syn-inversional marginal troughs to the main inversion zone. The Shatsky Ridge - the northern flank of the main East Black Sea Basin - may also be mainly a syn-inversional structure, underlain by a blind thrust zone expressed as a northward dipping zone of seismicity on the northern margin of the eastern Black Sea.

  6. Stroke and Native Hawaiians/Pacific Islanders

    Science.gov (United States)

    ... Hawaiians/Pacific Islanders Native Hawaiians/Pacific Islanders were four times more likely than non-Hispanic white adults to die from a stroke in 2010. In general, Native Hawaiian/Pacific Islander ...

  7. Tropical spastic paraparesis in Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    C. M. de Castro Costa

    1989-06-01

    Full Text Available Ten possible cases of tropical spastic paraparesis (TSP in Northeastern Brazil (Ceará are presented. They show the typical symptoms and signs of TSP consisting of weakness of the lower limbs, spastic gait, hiperreflexia, bladder dysfunction and variable signs of posterior columns impairment. The laboratory examinations excluded other compressive, infective, degenerative or demyelinating lesions of their spinal cord. Our patients age ranged from 21 to 59 years, all were of black origin and all were of lower social class. There was a slight preponderance of females. An etiological implication of a retrovirus (HTLV-I has been shown for TSP, but for lack of technical conditions we could not determine it in our patients, and that stands as our subsequent step in those and further cases.

  8. Seismic Event Relocation in Northeastern Russia

    Science.gov (United States)

    Romero-Yeske, M. D.; Steck, L.; Begnaud, M. L.; Mackey, K. G.; Fujita, K.; Stead, R.

    2009-12-01

    Northeastern Russia covers an area roughly equivalent to the United States, with seven seismic networks operating independently. Together, Michigan State University and Los Alamos National Laboratory researchers have merged catalogs from the Yakutsk, Magadan, Sakhalin, Kamchatka, and Irkutsk networks along with global bulletins and special studies to produce a unified research database for the region. We have developed regional phase travel time correction surfaces for P, Pn, Pg, S, and Sg/Lg using GT25 or better events, and are beginning to test relocation capabilities of less-well-constrained events with these kriged correction surfaces. Improvements in location will be judged on the basis of increased linearity and clustering of events across the study region, spanning a box from 40-75 degrees latitude and 80-190 degrees longitude. Relocation results for different combinations of phases will be presented.

  9. Controlling marginally detached divertor plasmas

    Science.gov (United States)

    Eldon, D.; Kolemen, E.; Barton, J. L.; Briesemeister, A. R.; Humphreys, D. A.; Leonard, A. W.; Maingi, R.; Makowski, M. A.; McLean, A. G.; Moser, A. L.; Stangeby, P. C.

    2017-06-01

    A new control system at DIII-D has stabilized the inter-ELM detached divertor plasma state for H-mode in close proximity to the threshold for reattachment, thus demonstrating the ability to maintain detachment with minimal gas puffing. When the same control system was instead ordered to hold the plasma at the threshold (here defined as T e  =  5 eV near the divertor target plate), the resulting T e profiles separated into two groups with one group consistent with marginal detachment, and the other with marginal attachment. The plasma dithers between the attached and detached states when the control system attempts to hold at the threshold. The control system is upgraded from the one described in Kolemen et al (2015 J. Nucl. Mater. 463 1186) and it handles ELMing plasmas by using real time D α measurements to remove during-ELM slices from real time T e measurements derived from divertor Thomson scattering. The difference between measured and requested inter-ELM T e is passed to a PID (proportional-integral-derivative) controller to determine gas puff commands. While some degree of detachment is essential for the health of ITER’s divertor, more deeply detached plasmas have greater radiative losses and, at the extreme, confinement degradation, making it desirable to limit detachment to the minimum level needed to protect the target plate (Kolemen et al 2015 J. Nucl. Mater. 463 1186). However, the observed bifurcation in plasma conditions at the outer strike point with the ion B   ×  \

  10. Hydrogenetic Ferromanganese Crusts of the California Continental Margin

    Science.gov (United States)

    Conrad, Tracey A.

    Hydrogenetic Ferromanganese (Fe-Mn) crusts grow from seawater and in doing so sequester elements of economic interest and serve as archives of past seawater chemistry. Ferromanganese crusts have been extensively studied in open-ocean environments. However, few studies have examined continent-proximal Fe-Mn crusts especially from the northeast Pacific. This thesis addresses Fe-Mn crusts within the northeast Pacific California continental margin (CCM), which is a dynamic geological and oceanographic environment. In the first of three studies, I analyzed the chemical and mineralogical composition of Fe-Mn crusts and show that continental-proximal processes greatly influence the chemistry and mineralogy of CCM Fe-Mn crusts. When compared to global open-ocean Fe-Mn crusts, CCM crusts have higher concentrations of iron, silica, and thorium with lower concentrations of many elements of economic interest including manganese, cobalt, and tellurium, among other elements. The mineralogy of CCM Fe-Mn crusts is also unique with more birnessite and todorokite present than found in open-ocean samples. Unlike open-ocean Fe-Mn crusts, carbonate-fluorapatite is not present in CCM crusts. This lack of phosphatization makes CCM Fe-Mn crusts excellent candidates for robust paleoceanography records. The second and third studies in this thesis use isotope geochemistry on select CCM Fe-Mn crusts from four seamounts in the CCM to study past terrestrial inputs into the CCM and sources and behavior of Pb and Nd isotopes over the past 7 million years along the northeast Pacific margin. The second study focuses on riverine inputs into the Monterey Submarine Canyon System and sources of the continental material. Osmium isotopes in the crusts are compared to the Cenozoic Os seawater curve to develop an age model for the samples that show the crusts range in age of initiation of crust growth from approximately 20 to 6 Myr. Lead and neodymium isotopes measured in select Fe-Mn crusts show that

  11. Data Reports for Retrospective Case Study in Northeastern Pennsylvania

    Science.gov (United States)

    This page includes the data reports for sampling rounds collected in Northeastern Pennsylvania conducted as part of EPA's Study of the Potential Impacts of Hydrualic Fracturing for Oil and Gas on Drinking Water Resources

  12. Marine magnetic anomalies in the northeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.; Chaubey, A; Murty, G.P.S.; Rao, D.G.; Scherbakov, V.S.; Lygin, V.A; Philipenko, A; Bogomyagkov, A

    Based on the analysis of some additional magnetic profiles, an updated correlation and identification of the sea-floor spreading type magnetic lineations in the northeastern Arabian Sea is presented. The anomaly 24 A-B sequence, characteris...

  13. Avian influenza virus antibodies in Pacific Coast Red Knots (Calidris canutus roselaari).

    Science.gov (United States)

    Johnson, James A; DeCicco, Lucas H; Ruthrauff, Daniel R; Krauss, Scott; Hall, Jeffrey S

    2014-07-01

    Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Knot (Calidris canutus rufa) is among the highest for any shorebird. To assess whether the frequency of detection of AIV antibodies is high for the species in general or restricted only to C. c. rufa, we sampled the northeastern Pacific Coast subspecies of Red Knot (Calidris canutus roselaari) breeding in northwestern Alaska. Antibodies were detected in 90% of adults and none of the chicks sampled. Viral shedding was not detected in adults or chicks. These results suggest a predisposition of Red Knots to AIV infection. High antibody titers to subtypes H3 and H4 were detected, whereas low to intermediate antibody levels were found for subtypes H10 and H11. These four subtypes have previously been detected in shorebirds at Delaware Bay (at the border of New Jersey and Delaware) and in waterfowl along the Pacific Coast of North America.

  14. Avian influenza virus antibodies in Pacific Coast Red Knots (Calidris canutus rufa)

    Science.gov (United States)

    Johnson, James A.; DeCicco, Lucas H.; Ruthrauff, Daniel R.; Krauss, Scott; Hall, Jeffrey S.

    2014-01-01

    Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Knot (Calidris canutus rufa) is among the highest for any shorebird. To assess whether the frequency of detection of AIV antibodies is high for the species in general or restricted only to C. c. rufa, we sampled the northeastern Pacific Coast subspecies of Red Knot (Calidris canutus roselaari) breeding in northwestern Alaska. Antibodies were detected in 90% of adults and none of the chicks sampled. Viral shedding was not detected in adults or chicks. These results suggest a predisposition of Red Knots to AIV infection. High antibody titers to subtypes H3 and H4 were detected, whereas low to intermediate antibody levels were found for subtypes H10 and H11. These four subtypes have previously been detected in shorebirds at Delaware Bay (at the border of New Jersey and Delaware) and in waterfowl along the Pacific Coast of North America.

  15. Marginal cost application in the power industry

    International Nuclear Information System (INIS)

    Twardy, L.; Rusak, H.

    1994-01-01

    Two kind of marginal costs, the short-run and the long-run, are defined. The former are applied in conditions when the load increase is not accompanied neither by the increase of the transmission capacity not the installed capacity while the latter assume new investments to expand the power system. The long-run marginal costs be used to forecast optimized development of the system. They contain two main components: the marginal costs of capacity and the marginal costs of energy. When the long-run marginal costs are calculated, each component is considered for particular voltage levels, seasons of the year, hours of the day - selected depending on the system reliability factor as well as on its load level. In the market economy countries the long-run marginal costs can be used for setting up the electric energy tariffs. (author). 7 refs, 11 figs

  16. Relation between denudation history and sediment supply from apatite fission track thermochronology in the northeast Brazilian Margin

    Science.gov (United States)

    Jelinek, Andrea; Chemale, Farid; Bueno, Gilmar

    2014-05-01

    The aim of this study is to provide a quantitative overview of Mesozoic-Cenozoic morphotectonic evolution and sediment supply to the northeast Brazilian margin. Landscape evolution and denudation histories for the northeastern Brazilian continental margin (Sergipe, Alagoas, Bahia, and Espírito Santo states) were detailed by apatite fission track thermochronology and thermal-history modeling and related with the sedimentological record of the offshore basins of the passive margin for a comparison with their denudational history. Approximately one hundred basement samples were analyzed from the coast to the inland of the Brazilian margin. The apparent fission track ages vary from 360 to 61 Ma and confined fission track lengths vary between 10 and 14.6 µm, indicating that not all of the samples recorded the same cooling events. The results of apatite fission track ages indicate that the area has been eroded regionally since the Mesozoic (Sergipe-Alagoas basins. Samples from the Conquista and Borborema Plateaus, and Mantiqueira Range record a Cretaceous-Paleogene onset of exhumation. This timing is consistent with the offshore sedimentary record, wherein a large clastic wedge started forming in the northeastern Sergipe-Alagoas basin, which suggests Sergipe-Alagoas basin records drainage reorganization and extension of the São Francisco River catchment. Interestingly, the Camamu basin, adjacent to the section of the margin does not record syn/post-rift exhumation, does contain a 6-km thick sedimentary succession, which should thus have been derived from more distal sources. The Neogene final denudation is observed throughout the study area and show conspicuous recent exhumation. The post-rift (<40 Ma) offshore sedimentation rates are generally lower than during preceding phases. This final sedimentary succession is thinner in all basins, consistent with limited onshore erosion during this time.

  17. Marginal Ice Zone: Biogeochemical Sampling with Gliders

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Marginal Ice Zone: Biogeochemical Sampling with Gliders...under the ice and in the marginal ice zone. The project specific goals are to develop biogeochemical and optical proxies for glider optics; to use the...water, in the marginal ice zone, and under the ice; to use glider optical measurements to compute fields of rates of photosynthetic carbon fixation

  18. The marginal costs of greenhouse gas emissions

    International Nuclear Information System (INIS)

    Tol, R.S.J.

    1999-01-01

    Estimates of the marginal costs of greenhouse gas emissions are on important input to the decision how much society would want to spend on greenhouse gas emission reduction. Marginal cost estimates in the literature range between $5 and $25 per ton of carbon. Using similar assumptions, the FUND model finds marginal costs of $9--23/tC, depending on the discount rate. If the aggregation of impacts over countries accounts for inequalities in income distribution or for risk aversion, marginal costs would rise by about a factor of 3. Marginal costs per region are an order of magnitude smaller than global marginal costs. The ratios between the marginal costs of CO 2 and those of CH 4 and N 2 O are roughly equal to the global warming potentials of these gases. The uncertainty about the marginal costs is large and right-skewed. The expected value of the marginal costs lies about 35% above the best guess, the 95-percentile about 250%

  19. Regional Marginal Abatement Cost Curves for NOx

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data underlying the figures included in the manuscript "Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and...

  20. Optimizing Surgical Margins in Breast Conservation

    Science.gov (United States)

    Ananthakrishnan, Preya; Balci, Fatih Levent; Crowe, Joseph P.

    2012-01-01

    Adequate surgical margins in breast-conserving surgery for breast cancer have traditionally been viewed as a predictor of local recurrence rates. There is still no consensus on what constitutes an adequate surgical margin, however it is clear that there is a trade-off between widely clear margins and acceptable cosmesis. Preoperative approaches to plan extent of resection with appropriate margins (in the setting of surgery first as well as after neoadjuvant chemotherapy,) include mammography, US, and MRI. Improvements have been made in preoperative lesion localization strategies for surgery, as well as intraoperative specimen assessment, in order to ensure complete removal of imaging findings and facilitate margin clearance. Intraoperative strategies to accurately assess tumor and cavity margins include cavity shave techniques, as well as novel technologies for margin probes. Ablative techniques, including radiofrequency ablation as well as intraoperative radiation, may be used to extend tumor-free margins without resecting additional tissue. Oncoplastic techniques allow for wider resections while maintaining cosmesis and have acceptable local recurrence rates, however often involve surgery on the contralateral breast. As systemic therapy for breast cancer continues to improve, it is unclear what the importance of surgical margins on local control rates will be in the future. PMID:23304479

  1. Assessment of seismic margin calculation methods

    International Nuclear Information System (INIS)

    Kennedy, R.P.; Murray, R.C.; Ravindra, M.K.; Reed, J.W.; Stevenson, J.D.

    1989-03-01

    Seismic margin review of nuclear power plants requires that the High Confidence of Low Probability of Failure (HCLPF) capacity be calculated for certain components. The candidate methods for calculating the HCLPF capacity as recommended by the Expert Panel on Quantification of Seismic Margins are the Conservative Deterministic Failure Margin (CDFM) method and the Fragility Analysis (FA) method. The present study evaluated these two methods using some representative components in order to provide further guidance in conducting seismic margin reviews. It is concluded that either of the two methods could be used for calculating HCLPF capacities. 21 refs., 9 figs., 6 tabs

  2. Optimizing Surgical Margins in Breast Conservation

    Directory of Open Access Journals (Sweden)

    Preya Ananthakrishnan

    2012-01-01

    Full Text Available Adequate surgical margins in breast-conserving surgery for breast cancer have traditionally been viewed as a predictor of local recurrence rates. There is still no consensus on what constitutes an adequate surgical margin, however it is clear that there is a trade-off between widely clear margins and acceptable cosmesis. Preoperative approaches to plan extent of resection with appropriate margins (in the setting of surgery first as well as after neoadjuvant chemotherapy, include mammography, US, and MRI. Improvements have been made in preoperative lesion localization strategies for surgery, as well as intraoperative specimen assessment, in order to ensure complete removal of imaging findings and facilitate margin clearance. Intraoperative strategies to accurately assess tumor and cavity margins include cavity shave techniques, as well as novel technologies for margin probes. Ablative techniques, including radiofrequency ablation as well as intraoperative radiation, may be used to extend tumor-free margins without resecting additional tissue. Oncoplastic techniques allow for wider resections while maintaining cosmesis and have acceptable local recurrence rates, however often involve surgery on the contralateral breast. As systemic therapy for breast cancer continues to improve, it is unclear what the importance of surgical margins on local control rates will be in the future.

  3. [Resection margins in conservative breast cancer surgery].

    Science.gov (United States)

    Medina Fernández, Francisco Javier; Ayllón Terán, María Dolores; Lombardo Galera, María Sagrario; Rioja Torres, Pilar; Bascuñana Estudillo, Guillermo; Rufián Peña, Sebastián

    2013-01-01

    Conservative breast cancer surgery is facing a new problem: the potential tumour involvement of resection margins. This eventuality has been closely and negatively associated with disease-free survival. Various factors may influence the likelihood of margins being affected, mostly related to the characteristics of the tumour, patient or surgical technique. In the last decade, many studies have attempted to find predictive factors for margin involvement. However, it is currently the new techniques used in the study of margins and tumour localisation that are significantly reducing reoperations in conservative breast cancer surgery. Copyright © 2012 AEC. Published by Elsevier Espana. All rights reserved.

  4. Intracaldera structure and megabreccias at Dorobu caldera, northeastern Honshu, Japan

    Science.gov (United States)

    Miura, Daisuke; Tamai, Masato

    1998-02-01

    In the Pliocene Dorobu caldera, 13 by 6 km in diameter, on northeastern Honshu, Japan, a number of occurrences of a distinctive megabreccia block facies is found within voluminous ash-flow tuffs, the Dorobu ash-flow tuffs A and B. Dorobu tuff A is believed to be the deposit of the initial caldera-forming eruption. An isopach map of tuff B and orientation of narrow dikes indicate that an internal large depression occurred inside the present caldera margin. This and locations of post-caldera conduits and near vent facies of Dorobu tuff C suggest that the caldera has a nested collapse structure, and possible conduits of the tuff B are within the internal depression. Annular collapses that sequentially moved towards the caldera center occurred during eruption of tuffs A and B. The overall structure of Dorobu caldera is nested, and it possibly has step-like floor, as described elsewhere from piecemeal calderas. Megabreccia block facies consists of polyhedral massive blocks composed of Miocene to Pliocene country rocks with large diameters (up to several hundreds meters). The block facies as a whole does not consist of sheets or piles of debris, as described in the San Juan Mountains and Stillwater Range, USA, but as isolated blocks set in the matrix of Dorobu tuffs A and B. In previous studies of caldera development, the mode of emplacement of caldera-collapse breccias has been considered to be by rock fall or rock slide during the caldera forming eruption. A paleo-magnetic study of the block facies shows two significant characteristics. Predominant variations of the magnetic directions of blocks indicate that they were emplaced with rotations, caused by rock slide, rock fall, or a toppling motion. In contrast, magnetized directions of one megabreccia block almost coincide with that of the caldera country rock, suggesting that this block must have kept its original magnetic direction. Our findings suggest that it is not a rock slide deposit derived from caldera walls

  5. Igneous series in island arcs: The northeastern Caribbean compared with worldwide island-arc assemblages

    Science.gov (United States)

    Donnelly, T. W.; Rogers, J. J. W.

    1980-06-01

    Two major magma series are recognised in the northeastern Carribean island arcs and correlated with numerous examples elsewhere, mainly in the western Pacific. The Primitive Island Arc (PIA) series is apparently the oldest in each of its island-arc occurrences and is followed by the calcalkaline (CA) series, which locally co-occurs with a high-potassium (HK) variety, especially in topographically larger island areas. Also occurring in the northeastern Caribbean are tectonically emplaced examples of metamorphosed mid-ocean ridge basalt (MORB) and a diabase dike swarm possibly related to a rifting event. PIA series is distinguished from the CA by its lower content of LIL elements, including REE. Th, U, Zr, K, and Ba. The difference is most striking in the abundant siliceous differentiates of this series, in which these elements are scarcely higher in abundance than in mafic examples. The HK series is considered to be a subseries of the CA which is higher in K, Ba, Sr, Mg, and Ni, but has REE, Th, and other element levels very similar to the CA. The PIA series has been confused with MORB but has lower REE (with flatter patterns generally), much lower Ni, lower Ti, Zr, and Mg, and appears to be intrinsically hydrated. The abundance of siliceous differentiates also separates this series from MORB. PIA magma is believed to be generated by massive melting of hydrated mantle which rises in front of the descending snout of a newly subducting slab at the initial stage of island-arc genesis; i.e., before the island-arc platform has formed. CA magma has a different source and is probably the partially fused material of the slab itself, more or less modified by volcanic-sedimentary materials dragged to depth during subduction.

  6. Atmospheric forcing of the eastern tropical Pacific: A review

    Science.gov (United States)

    Amador, Jorge A.; Alfaro, Eric J.; Lizano, Omar G.; Magaña, Victor O.

    2006-05-01

    the westward propagation and development of disturbances that may hit the eastern tropical Pacific, such as easterly waves and tropical cyclones, are still unclear. Changes in the intensity of the trade winds in the Caribbean Sea and the Gulf of Mexico (associated with eastern tropical Pacific wind jets) exert an important control on precipitation by means of wind-topography interactions. Gaps in the mountains of southern Mexico and Central America allow strong wind jets to pass over the continent imprinting a unique signal in sea surface temperatures and ocean dynamics of the eastern tropical Pacific. The warm pools of the Americas constitute an important source of moisture for the North American Monsoon System. The northeastern tropical Pacific is a region of intense cyclogenetic activity, just west of the coast of Mesoamerica. Over the oceanic regions, large-scale properties of key variables such as precipitation, moisture, surface energy fluxes and wind stress curl are still uncertain, which inhibits a more comprehensive view of the region and stresses the importance of regional field experiments. Progress has been substantial in the understanding of the ocean and atmospheric dynamics of the eastern tropical Pacific, however, recent observational evidence such as that of a shallow meridional circulation cell in that region, in contrast to the classic concept of the Hadley-type deep meridional circulation, suggests that more in situ observations to validate theories are still necessary. This paper is part of a comprehensive review of the oceanography of the eastern tropical Pacific Ocean.

  7. Immunohistochemical characterization of the chick marginal retina

    Directory of Open Access Journals (Sweden)

    I.P. Lima

    2007-11-01

    Full Text Available The retina is a highly differentiated tissue with a complex layered structure that has been extensively characterized. However, most of the previous studies focused on the histology of the central retina while little is known about the cellular composition, organization and function of the marginal retina. Recent research has identified a subpopulation of multipotential progenitor cells in the marginal regions of the retina, closest to the ciliary body ("ciliary marginal zone". These cells are capable of differentiation in response to an appropriate stimulus. Thus, it is possible that the structure and composition of the marginal retina are distinct from those of the central retina to accommodate the potential addition of newly formed neurons. To characterize the cellular profile of the chick marginal retina, we labeled it immunohistochemically for markers whose staining pattern is well established in the central retina: calbindin, calretinin, protein kinase C, and choline acetyltransferase. Calbindin was present at very low levels in the marginal retina putative photoreceptor layer. Calretinin-positive horizontal cells were also sparse close to the ciliary marginal zone. The bipolar cells in the marginal outer plexiform layer were positive for anti-protein kinase C antibodies, but the density of labeling was also decreased in relation to the central retina. In contrast, the marginal starburst cholinergic amacrine cell pattern was very similar to the central retina. From these data we conclude that the structure of the marginal retina is significantly different from that of the central retina. In particular, the expression of late retina markers in the marginal retina decreased in comparison to the central retina.

  8. Who Do You Say I Am? Explaining the Marginalized Status of Pasifika Students' Academic Achievement by Examining the Conflict between Institutional Perceptions and the "Identifying Process."

    Science.gov (United States)

    Nakhid, Camille

    This paper looks at how institutional perceptions of marginalized groups of students affect their achievement, and argues that an "identifying process" involving students' own construction of themselves is necessary to academic success. In New Zealand, schools focus on the ethnicity of Pasifika (Pacific Islander) students in terms of low…

  9. An Alternative Home? ASEAN and Pacific Environmental Migration

    Directory of Open Access Journals (Sweden)

    GIL MARVEL PIANO TABUCANON

    2013-03-01

    Full Text Available An Alternative Home? ASEAN and Pacific Environmental Migration ASEAN is in a unique position to push for heightened global awareness and action for the vulnerable Pacific populations facing the possibility of relocation. Yet, it is strangely silent on the issue. ASEAN has both moral and legal obligation to not to turn its back on its Pacific neighbours. Morally, ASEAN – or at least most of it – is part of the western fringes of the Pacific region. It is proximate to many Pacific nations, and it has both the resources and landmass to help: two of the world’s largest archipelagos are ASEAN members. The obligations of humanity and justice require larger and more developed states aid and assist their more vulnerable neighbours. Legally, ASEAN may learn from the African Union (AU experience. While AU accepted the UN Refugee Convention definition of ‘refugee,’ it expanded it to include those compelled to leave their country owing to ‘events seriously disturbing public order.’ Many scholars believe this includes the environmentally displaced. ASEAN can choose to take on the easy path of insularity and parochialism as regards the looming issue on environmental migration, or it can take the high road by transforming itself into a dynamic regional actor pushing for clear policies on how to address it. Displacements are by nature traumatic and carry with them the impoverishments of landlessness, joblessness, homelessness, marginalization, increased morbidity and mortality, food insecurity, loss of access to common property resources, and social disarticulation. ASEAN can do much to help its vulnerable neighbors. As a bloc, it is a strong voice that can speak to the larger international community asking it to help address the issue.

  10. Exactly marginal deformations from exceptional generalised geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ashmore, Anthony [Merton College, University of Oxford,Merton Street, Oxford, OX1 4JD (United Kingdom); Mathematical Institute, University of Oxford,Andrew Wiles Building, Woodstock Road, Oxford, OX2 6GG (United Kingdom); Gabella, Maxime [Institute for Advanced Study,Einstein Drive, Princeton, NJ 08540 (United States); Graña, Mariana [Institut de Physique Théorique, CEA/Saclay,91191 Gif-sur-Yvette (France); Petrini, Michela [Sorbonne Université, UPMC Paris 05, UMR 7589, LPTHE,75005 Paris (France); Waldram, Daniel [Department of Physics, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom)

    2017-01-27

    We apply exceptional generalised geometry to the study of exactly marginal deformations of N=1 SCFTs that are dual to generic AdS{sub 5} flux backgrounds in type IIB or eleven-dimensional supergravity. In the gauge theory, marginal deformations are parametrised by the space of chiral primary operators of conformal dimension three, while exactly marginal deformations correspond to quotienting this space by the complexified global symmetry group. We show how the supergravity analysis gives a geometric interpretation of the gauge theory results. The marginal deformations arise from deformations of generalised structures that solve moment maps for the generalised diffeomorphism group and have the correct charge under the generalised Reeb vector, generating the R-symmetry. If this is the only symmetry of the background, all marginal deformations are exactly marginal. If the background possesses extra isometries, there are obstructions that come from fixed points of the moment maps. The exactly marginal deformations are then given by a further quotient by these extra isometries. Our analysis holds for any N=2 AdS{sub 5} flux background. Focussing on the particular case of type IIB Sasaki-Einstein backgrounds we recover the result that marginal deformations correspond to perturbing the solution by three-form flux at first order. In various explicit examples, we show that our expression for the three-form flux matches those in the literature and the obstruction conditions match the one-loop beta functions of the dual SCFT.

  11. Exactly marginal deformations from exceptional generalised geometry

    International Nuclear Information System (INIS)

    Ashmore, Anthony; Gabella, Maxime; Graña, Mariana; Petrini, Michela; Waldram, Daniel

    2017-01-01

    We apply exceptional generalised geometry to the study of exactly marginal deformations of N=1 SCFTs that are dual to generic AdS 5 flux backgrounds in type IIB or eleven-dimensional supergravity. In the gauge theory, marginal deformations are parametrised by the space of chiral primary operators of conformal dimension three, while exactly marginal deformations correspond to quotienting this space by the complexified global symmetry group. We show how the supergravity analysis gives a geometric interpretation of the gauge theory results. The marginal deformations arise from deformations of generalised structures that solve moment maps for the generalised diffeomorphism group and have the correct charge under the generalised Reeb vector, generating the R-symmetry. If this is the only symmetry of the background, all marginal deformations are exactly marginal. If the background possesses extra isometries, there are obstructions that come from fixed points of the moment maps. The exactly marginal deformations are then given by a further quotient by these extra isometries. Our analysis holds for any N=2 AdS 5 flux background. Focussing on the particular case of type IIB Sasaki-Einstein backgrounds we recover the result that marginal deformations correspond to perturbing the solution by three-form flux at first order. In various explicit examples, we show that our expression for the three-form flux matches those in the literature and the obstruction conditions match the one-loop beta functions of the dual SCFT.

  12. Technical specification improvement through safety margin considerations

    International Nuclear Information System (INIS)

    Howard, R.C.; Jansen, R.L.

    1986-01-01

    Westinghouse has developed an approach for utilizing safety analysis margin considerations to improve plant operability through technical specification revision. This approach relies on the identification and use of parameter interrelations and sensitivities to identify acceptable operating envelopes. This paper summarizes technical specification activities to date and presents the use of safety margin considerations as another viable method to obtain technical specification improvement

  13. 17 CFR 242.403 - Required margin.

    Science.gov (United States)

    2010-04-01

    ...) REGULATIONS M, SHO, ATS, AC, AND NMS AND CUSTOMER MARGIN REQUIREMENTS FOR SECURITY FUTURES Customer Margin... of a customer in a securities account or futures account as set forth in this section. (b) Required... be twenty (20) percent of the current market value of such security future. (2) Offsetting positions...

  14. Plume-stagnant slab-lithosphere interactions: Origin of the late Cenozoic intra-plate basalts on the East Eurasia margin

    Science.gov (United States)

    Kimura, Jun-Ichi; Sakuyama, Tetsuya; Miyazaki, Takashi; Vaglarov, Bogdan S.; Fukao, Yoshio; Stern, Robert J.

    2018-02-01

    Intra-plate basalts of 35-0 Ma in East Eurasia formed in a broad backarc region above the stagnant Pacific Plate slab in the mantle transition zone. These basalts show regional-scale variations in Nd-Hf isotopes. The basalts with the most radiogenic Nd-Hf center on the Shandong Peninsula with intermediate Nd-Hf at Hainan and Datong. The least radiogenic basalts occur in the perimeters underlain by the thick continental lithosphere. Shandong basalts possess isotopic signatures of the young igneous oceanic crust of the subducted Pacific Plate. Hainan and Datong basalts have isotopic signatures of recycled subduction materials with billions of years of storage in the mantle. The perimeter basalts have isotopic signatures similar to pyroxenite xenoliths from the subcontinental lithospheric mantle beneath East Eurasia. Hainan basalts exhibit the highest mantle potential temperature (Tp), while the Shandong basalts have the lowest Tp. We infer that a deep high-Tp plume interacted with the subducted Pacific Plate slab in the mantle transition zone to form a local low-Tp plume by entraining colder igneous oceanic lithosphere. We infer that the subducted Izanagi Plate slab, once a part of the Pacific Plate mosaic, broke off from the Pacific Plate slab at 35 Ma to sink into the lower mantle. The sinking Izanagi slab triggered the plume that interacted with the stagnant Pacific slab and caused subcontinental lithospheric melting. This coincided with formation of the western Pacific backarc marginal basins due to Pacific Plate slab rollback and stagnation.

  15. Paleogene continental margin truncation in southwestern Mexico: Geochronological evidence

    Science.gov (United States)

    Schaaf, Peter; MoráN-Zenteno, Dante; HernáNdez-Bernal, Maria Del Sol; SolíS-Pichardo, Gabriela; Tolson, Gustavo; KöHler, Hermann

    1995-12-01

    The reasons for, and mechanisms of, continental margin truncation in SW Mexico where Mesozoic-Cenozoic plutons are situated directly on the Pacific coast, are not yet well understood. Large-scale dextral and/or sinistral displacements of the continental margin terranes, now forming parts of Baja California or the Chortis block, have been proposed. The well-defined along-coast NW-SE decreasing granitoid intrusion age trend (˜1.2 cm/yr in the 100 Ma-40 Ma time interval) between Puerto Vallarta and Zihuatanejo is interpreted by us to be a geometric artifact of oblique continental margin truncation rather than the consequence of a sinistral offset of the Chortis block from those latitudes toward the SE. Changes in the dip and velocity of the NNW-SSE trending Cretaceous-Tertiary subduction zone resulted in a landward migration of the magmatic arc. Taking into account certain stratigraphic affinities of Chortis and the Oaxaca and Mixteca terranes, together with the known displacement rates along the North America-Caribbean Plate boundary, the northwesternmost paleoposition of the Chortis block with respect to SW Mexico was near Zihuatanejo. In contrast, between Zihuatanejo and the Isthmus of Tehuantepec, the cessation of the Tertiary magmatism decreased more rapidly (˜7.7 cm/yr), although the trend is not so obvious. Starting in the late Eocene, Chortis moved about 1100 km to the SE along a transform boundary associated with the opening of the Cayman Trough. Based on our geochronological data and structural relationships between mylonite zones and plutons in the Acapulco-Tehuantepec area, we propose an approximately 650 km SE movement of Chortis from about 40-25 Ma, with a velocity of 6.5-4.3 cm/yr. Since this is considerably slower than the decreasing age trend obtained by us using the geochronological data, we consider batholith formation in this segment to predate and postdate the offshore passage of the North America-Farallon-Caribbean triple junction. Geological

  16. Paleoenvironment of the Dalichai Formation, northeastern Semnan

    Directory of Open Access Journals (Sweden)

    Navid Navidi Izad

    2015-02-01

    Full Text Available Abstract Palaeonvironment of the Dalichai Formation, northeastern Semnan, is envisaged based on 69 samples studied palynologically. Diverse and well-preserved palynofloras, viz., miospores, dinoflagellate cysts, foraminiferal test linings, acritarchs, wood debris (plant tissue and Amorphous Organic Matters (AOM occur in the material examined. The presence of relatively abundant proximate dinoflagellates and ±laevigate acritarchs in the lower part of the section studied implies sedimentation in a turbulent shallow environment. However, occurrence in the upper part of the section of abundant chorate dinoflagellates as well as notable proportion of blade-shaped to equal dimensional opaque palynomacerals seem to signify marine incursion and accumulation in an open marine setting. In most of the samples examined, prevalence of transparent AOM denotes a low oxygenated environment and slow rate of accumulation. Moreover, incidence of three palynofacies types (II, IV, VI in the pertinent material also corroborates a shallow low oxygenated environment with low sedimentation rate which gradually deepened upward in the section.

  17. Paleoenvironment of the Dalichai Formation, northeastern Semnan

    Directory of Open Access Journals (Sweden)

    Fereshteh Sajjadi

    2015-01-01

    Full Text Available Abstract Palaeonvironment of the Dalichai Formation, northeastern Semnan, is envisaged based on 69 samples studied palynologically. Diverse and well-preserved palynofloras, viz., miospores, dinoflagellate cysts, foraminiferal test linings, acritarchs, wood debris (plant tissue and Amorphous Organic Matters (AOM occur in the material examined. The presence of relatively abundant proximate dinoflagellates and ±laevigate acritarchs in the lower part of the section studied implies sedimentation in a turbulent shallow environment. However, occurrence in the upper part of the section of abundant chorate dinoflagellates as well as notable proportion of blade-shaped to equal dimensional opaque palynomacerals seem to signify marine incursion and accumulation in an open marine setting. In most of the samples examined, prevalence of transparent AOM denotes a low oxygenated environment and slow rate of accumulation. Moreover, incidence of three palynofacies types (II, IV, VI in the pertinent material also corroborates a shallow low oxygenated environment with low sedimentation rate which gradually deepened upward in the section.

  18. Multi-Proxy Reconstructions of Northeast Pacific Decadal Variability from Bivalve Mollusks and Trees

    Science.gov (United States)

    Black, B.; Griffin, D.

    2017-12-01

    Decadal-scale climate variability in the Northeast Pacific Ocean profoundly influences fisheries production, forest growth, wildfire, drought, and snowpack in western North America. However, there remains considerable and long-standing uncertainly in its behavior prior to AD 1900 and the extent to which 20th century dynamics are atypical in a multi-centennial context. Here, we target the leading EOF of SST in the northeastern Pacific (ARCSST) as an index of Pacific Decadal Variability, which has been dynamically linked to sea level pressure and unlike the Pacific Decadal Oscillation Index, retains a linear warming trend. The ARCSST reconstruction is generated from a broad network of target-sensitive North American tree-ring data standardized using signal-free detrending to preserve lower frequency signals common to the original data. In a preliminary analysis, the mean of the approximately 50 chronologies that significantly (p century-long quiescent periods can occur, iii) 20th century regime shifts are typical, but iv) late 20th century warming is atypical in the longer-term context. Moreover, the reconstruction closely tracks paleofisheries datasets, particularly northern anchovy (Engraulis mordax) abundance inferred from scale deposition rates in the Santa Barbara Basin.

  19. Living (stained) deep-sea foraminifera off Hachinohe (NE Japan, Western Pacific): environmental interplay in oxygen-depleted ecosystems

    NARCIS (Netherlands)

    Fontanier, C.; Duros, P.; Toyofuku, T.; Oguri, K.; Koho, K.A.; Buscail, R.; Grémare, A.; Radakovitch, O.; Deflandre, B.; de Nooijer, L.J.; Bichon, S.; Goubet, S.; Ivanovsky, A.; Chabaud, G.; Menniti, C.; Reichart, G.-J.; Kitazato, H.

    2014-01-01

    Live (Rose-Bengal stained) deep-sea foraminiferal faunashave been studied at five stations between 500–2000-m depthalong the NE Japanese margin (western Pacific) tounderstand how complex environmental conditions (e.g.,oxygen depletion, organic matter) control their structure(i.e., diversity,

  20. Social marginalization of overweight children.

    Science.gov (United States)

    Strauss, Richard S; Pollack, Harold A

    2003-08-01

    Overweight is the most common health problem that faces children and adolescents. Although the correlation among overweight, low self-esteem, and depression is well known, social isolation among overweight children and adolescents has not been studied. To investigate social networks of overweight and normal-weight adolescents in a large, nationally representative sample. Cross-sectional, nationally representative cohort study. Population A total of 90 118 adolescents aged 13 to 18 years who were enrolled in the National Longitudinal Study of Adolescent Health, of which a 1:5 subsample was selected for detailed in-home assessment, including height and weight measurements (n = 17 557). Overweight was defined according to body mass index (>95th percentile for age and sex). This analysis focuses on the number of friendship nominations each adolescent received from other adolescents. The number of friendship nominations and other social network measures were calculated using statistical software. Overweight adolescents were more likely to be socially isolated and to be peripheral to social networks than were normal-weight adolescents. Although overweight adolescents listed similar numbers of friends as normal-weight adolescents, overweight adolescents received significantly fewer friendship nominations from others than were received by normal-weight adolescents (mean [SE] number of friendship nominations, 3.39 [0.08] vs 4.79 [0.04]; POverweight adolescents were also more likely to receive no friendship nominations than were normal-weight adolescents (odds ratio, 1.71; 95% confidence interval, 1.39-2.20). Decreased television viewing (Poverweight and normal-weight adolescents. Many overweight adolescents are socially marginalized. Such isolation may aggravate the social and emotional consequences of overweight in this age group.

  1. MARGINS: Toward a novel science plan

    Science.gov (United States)

    Mutter, John C.

    A science plan to study continental margins has been in the works for the past 3 years, with almost 200 Earth scientists from a wide variety of disciplines gathering at meetings and workshops. Most geological hazards and resources are found at continental margins, yet our understanding of the processes that shape the margins is meager.In formulating this MARGINS research initiative, fundamental issues concerning our understanding of basic Earth-forming processes have arisen. It is clear that a business-as-usual approach will not solve the class of problems defined by the MARGINS program; the solutions demand approaches different from those used in the past. In many cases, a different class of experiment will be required, one that is well beyond the capability of individual principle investigators to undertake on their own. In most cases, broadly based interdisciplinary studies will be needed.

  2. Margin Requirements and Equity Option Returns

    DEFF Research Database (Denmark)

    Hitzemann, Steffen; Hofmann, Michael; Uhrig-Homburg, Marliese

    In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant margin premium in the cross-section of equity option returns. The sign of the margin...... premium depends on demand pressure: If end-users are on the long side of the market, option returns decrease with margins, while they increase otherwise. Our results are statistically and economically significant and robust to different margin specifications and various control variables. We explain our...... findings by a model of funding-constrained derivatives dealers that require compensation for satisfying end-users’ option demand....

  3. Margin Requirements and Equity Option Returns

    DEFF Research Database (Denmark)

    Hitzemann, Steffen; Hofmann, Michael; Uhrig-Homburg, Marliese

    In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant "margin premium" in the cross-section of equity option returns. The sign of the margin...... premium depends on demand pressure: If end-users are on the long side of the market, option returns decrease with margins, while they increase otherwise. Our results are statistically and economically significant and robust to different margin specifications and various control variables. We explain our...... findings by a model of funding-constrained derivatives dealers that require compensation for satisfying end-users’ option demand....

  4. Dynamical and Thermodynamic Elements of Modeled Climate Change at the East African Margin of Convection

    Science.gov (United States)

    Giannini, Alessandra; Lyon, Bradfield; Seager, Richard; Vigaud, Nicolas

    2018-01-01

    We propose a dynamical interpretation of model projections for an end-of-century wetting in equatorial East Africa. In the current generation of global climate models, increased atmospheric moisture content associated with warming is not the dominant process explaining the increase in rainfall, as the regional circulation is only weakly convergent even during the rainy seasons. Instead, projected wetter future conditions are generally consistent with the El Niño-like trend in tropical Pacific sea surface temperatures in climate models. In addition, a weakening in moisture convergence over the adjacent Congo Basin and Maritime Continent cores of convection results in the weakening of near-surface winds, which increases moisture advection from the Congo Basin core toward the East African margin. Overall confidence in the projections is limited by the significant biases in simulation of the regional climatology and disagreement between observed and modeled tropical Pacific sea surface temperature trends to date.

  5. Arctic Ocean outflow and glacier–ocean interactions modify water over the Wandel Sea shelf (northeastern Greenland

    Directory of Open Access Journals (Sweden)

    I. A. Dmitrenko

    2017-12-01

    Full Text Available The first-ever conductivity–temperature–depth (CTD observations on the Wandel Sea shelf in northeastern Greenland were collected in April–May 2015. They were complemented by CTDs taken along the continental slope during the Norwegian FRAM 2014–2015 drift. The CTD profiles are used to reveal the origin of water masses and interactions with ambient water from the continental slope and the tidewater glacier outlet. The subsurface water is associated with the Pacific water outflow from the Arctic Ocean. The underlying halocline separates the Pacific water from a deeper layer of polar water that has interacted with the warm Atlantic water outflow through the Fram Strait, recorded below 140 m. Over the outer shelf, the halocline shows numerous cold density-compensated intrusions indicating lateral interaction with an ambient polar water mass across the continental slope. At the front of the tidewater glacier outlet, colder and turbid water intrusions were observed at the base of the halocline. On the temperature–salinity plots these stations indicate a mixing line that is different from the ambient water and seems to be conditioned by the ocean–glacier interaction. Our observations of Pacific water are set within the context of upstream observations in the Beaufort Sea and downstream observations from the Northeast Water Polynya, and clearly show the modification of Pacific water during its advection across the Arctic Ocean. Moreover, ambient water over the Wandel Sea slope shows different thermohaline structures indicating the different origin and pathways of the on-shore and off-shore branches of the Arctic Ocean outflow through the western Fram Strait.

  6. Arctic Ocean outflow and glacier-ocean interactions modify water over the Wandel Sea shelf (northeastern Greenland)

    Science.gov (United States)

    Dmitrenko, Igor A.; Kirillov, Sergey A.; Rudels, Bert; Babb, David G.; Toudal Pedersen, Leif; Rysgaard, Søren; Kristoffersen, Yngve; Barber, David G.

    2017-12-01

    The first-ever conductivity-temperature-depth (CTD) observations on the Wandel Sea shelf in northeastern Greenland were collected in April-May 2015. They were complemented by CTDs taken along the continental slope during the Norwegian FRAM 2014-2015 drift. The CTD profiles are used to reveal the origin of water masses and interactions with ambient water from the continental slope and the tidewater glacier outlet. The subsurface water is associated with the Pacific water outflow from the Arctic Ocean. The underlying halocline separates the Pacific water from a deeper layer of polar water that has interacted with the warm Atlantic water outflow through the Fram Strait, recorded below 140 m. Over the outer shelf, the halocline shows numerous cold density-compensated intrusions indicating lateral interaction with an ambient polar water mass across the continental slope. At the front of the tidewater glacier outlet, colder and turbid water intrusions were observed at the base of the halocline. On the temperature-salinity plots these stations indicate a mixing line that is different from the ambient water and seems to be conditioned by the ocean-glacier interaction. Our observations of Pacific water are set within the context of upstream observations in the Beaufort Sea and downstream observations from the Northeast Water Polynya, and clearly show the modification of Pacific water during its advection across the Arctic Ocean. Moreover, ambient water over the Wandel Sea slope shows different thermohaline structures indicating the different origin and pathways of the on-shore and off-shore branches of the Arctic Ocean outflow through the western Fram Strait.

  7. Western Pacific Typhoon Aircraft Fixes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Western Pacific typhoon aircraft reconnaissance data from the years 1946 - 1965 and 1978, excluding 1952, were transcribed from original documents, or copy of...

  8. Holocene Paleoceanographic Environments at the Chukchi-Alaskan Margin: Implications for Future Changes

    Science.gov (United States)

    Polyak, L.; Nam, S. I.; Dipre, G.; Kim, S. Y.; Ortiz, J. D.; Darby, D. A.

    2017-12-01

    The impacts of the North Pacific oceanic and atmospheric system on the Arctic Ocean result in accelerated sea-ice retreat and related changes in hydrography and biota in the western Arctic. Paleoclimatic records from the Pacific sector of the Arctic are key for understanding the long-term history of these interactions. As opposed to stratigraphically long but strongly compressed sediment cores recovered from the deep Arctic Ocean, sediment depocenters on the Chukchi-Alaskan margin yield continuous, medium to high resolution records formed since the last deglaciation. While early Holocene conditions were non-analogous to modern environments due to the effects of prolonged deglaciation and insufficiently high sea levels, mid to late Holocene sediments are more relevant for recent and modern climate variability. Notably, a large depocenter at the Alaskan margin has sedimentation rates estimated as high as a few millimeters per year, thus providing a decadal to near-annual resolution. This high accumulation can be explained by sediment delivery via the Alaskan Coastal Current originating from the Bering Sea and supposedly controlled by the Aleutian Low pressure center. Preliminary results from sediment cores recovering the last several centuries, along with a comparison with other paleoclimatic proxy records from the Arctic-North Pacific region, indicate a persistent role of the Aleutian Low in the Bering Strait inflow and attendant deposition. More proxy studies are underway to reconstruct the history of this circulation system and its relationship with sea ice extent. The expected results will improve our understanding of natural variability in oceanic and atmospheric conditions at the Chukchi-Alaskan margin, a critical area for modulating the Arctic climate change.

  9. 78 FR 41033 - Fisheries of the Northeast Region, Southeast Region, North Pacific Region, Pacific Region...

    Science.gov (United States)

    2013-07-09

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC399 Fisheries of the Northeast Region, Southeast Region, North Pacific Region, Pacific Region; Western Pacific Region AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA...

  10. Voices from the Margins: Policy Advocacy and Marginalized Communities

    Directory of Open Access Journals (Sweden)

    Gloria DeSantis

    2010-01-01

    Full Text Available This article aims to explore policy advocacy processes facilitated by social service nonprofit organizations (NPOs using a social justice lens. Qualitative interview results from 39 NPOs from 18 communities provide a deeper understanding of advocacy, revealing that NPOs perceive that policy advocacy is not a discrete phenomenon, that advocacy activity differs in visibility and scale, and that advocacy strategies are clearly informed by NPOs' front-line service delivery work. A typology of policy advocacy showing different advocacy types and their fluid nature is presented. The results also show that marginalized people's involvement varies depending on a diversity of influential conditions. Conclusions and implications focus on social inclusion/exclusion, the varied and fluid nature of policy advocacy, challenges for practitioners, and the complex nature of "advocacy chill. / "Les organismes sans but lucratif (OSBL de services sociaux ont pour mission de préserver la santé des communautés au moyen de défense de politiques sociales. Toutefois, peu d'études concrètes au Canada portent sur la nature des processus en cause, en particulier lorsqu'il s'agit de politiques mises en œuvre au sein de collectivités marginalisées. Cet article a pour but d'explorer sous l'angle de la justice sociale la nature des processus défense des politiques tels qu'ils sont pratiqués par les OSBL de services sociaux. Un entretien qualitatif avec 39 OSBL issues de 18 collectivités permet une meilleure compréhension des processus. Les OSBL ne conçoivent pas défense des politiques comme un phénomène discret; les activités qui y sont reliées varient en visibilité et en étendue, et les stratégies employées sont clairement influencées par les services de première ligne qu'offrent les OSBL. Nous proposons une typologie des processus défense des politiques exposant les différents types d'approches et leur nature changeante. Les résultats indiquent

  11. A Cenozoic diffuse alkaline magmatic province (DAMP) in the southwest Pacific without rift or plume origin

    Science.gov (United States)

    Finn, Carol A.; Müller, R. Dietmar; Panter, Kurt S.

    2005-02-01

    Common geological, geochemical, and geophysical characteristics of continental fragments of East Gondwana and adjacent oceanic lithosphere define a long-lived, low-volume, diffuse alkaline magmatic province (DAMP) encompassing the easternmost part of the Indo-Australian Plate, West Antarctica, and the southwest portion of the Pacific Plate. A key to generating the Cenozoic magmatism is the combination of metasomatized lithosphere underlain by mantle at only slightly elevated temperatures, in contrast to large igneous provinces where mantle temperatures are presumed to be high. The SW Pacific DAMP magmatism has been conjecturally linked to rifting, strike-slip faulting, mantle plumes, or hundreds of hot spots, but all of these associations have flaws. We suggest instead that sudden detachment and sinking of subducted slabs in the late Cretaceous induced Rayleigh-Taylor instabilities along the former Gondwana margin that in turn triggered lateral and vertical flow of warm Pacific mantle. The interaction of the warm mantle with metasomatized subcontinental lithosphere that characterizes much of the SW Pacific DAMP concentrates magmatism along zones of weakness. The model may also provide a mechanism for warming south Pacific mantle and resulting Cenozoic alkaline magmatism, where the oceanic areas are characterized primarily, but not exclusively, by short-lived hot spot tracks not readily explained by conventional mantle plume theory. This proposed south Pacific DAMP is much larger and longer-lived than previously considered.

  12. Demersal fish assemblages on seamounts and other rugged features in the northeastern Caribbean

    Science.gov (United States)

    Quattrini, Andrea M.; Demopoulos, Amanda W. J.; Singer, Randal; Roa-Varon, Adela; Chaytor, Jason D.

    2017-05-01

    Recent investigations of demersal fish communities in deepwater (>50 m) habitats have considerably increased our knowledge of the factors that influence the assemblage structure of fishes across mesophotic to deep-sea depths. While different habitat types influence deepwater fish distribution, whether different types of rugged seafloor features provide functionally equivalent habitat for fishes is poorly understood. In the northeastern Caribbean, different types of rugged features (e.g., seamounts, banks, canyons) punctuate insular margins, and thus create a remarkable setting in which to compare demersal fish communities across various features. Concurrently, several water masses are vertically layered in the water column, creating strong stratification layers corresponding to specific abiotic conditions. In this study, we examined differences among fish assemblages across different features (e.g., seamount, canyon, bank/ridge) and water masses at depths ranging from 98 to 4060 m in the northeastern Caribbean. We conducted 26 remotely operated vehicle dives across 18 sites, identifying 156 species of which 42% of had not been previously recorded from particular depths or localities in the region. While rarefaction curves indicated fewer species at seamounts than at other features in the NE Caribbean, assemblage structure was similar among the different types of features. Thus, similar to seamount studies in other regions, seamounts in the Anegada Passage do not harbor distinct communities from other types of rugged features. Species assemblages, however, differed among depths, with zonation generally corresponding to water mass boundaries in the region. High species turnover occurred at depths influencing community structure of benthic fauna, while considerably adding to the knowledge of mesophotic and deep-sea fish biogeography.

  13. Effect of Margin Designs on the Marginal Adaptation of Zirconia Copings

    Directory of Open Access Journals (Sweden)

    Syed Rashid Habib

    2017-01-01

    Full Text Available Objective: The aim of this in vitro study was to investigate the effect of Shoulder versus Chamfer margin design on the marginal adaptation of zirconia (Zr copings. Materials and Methods: 40 extracted molar teeth were mounted in resin and prepared for zirconia crowns with two margin preparation designs (20=Shoulder and 20=Chamfer. The copings were manufactured by Cercon® (DeguDent GmbH, Germany using the CAD/CAM system for each tooth. They were tried on each tooth, cemented, thermocycled, re-embedded in resin and were subsequently cross sectioned centrally into two equal mesial and distal halves. They were examined under electron microscope at 200 X magnification and the measurements were recorded at 5 predetermined points in micrometers (µm. Results: The overall mean marginal gap for the two groups was found to be 206.98+42.78µm with Shoulder margin design (Marginal Gap=199.50+40.72µm having better adaptation compared to Chamfer (Marginal Gap=214.46+44.85µm. The independent-samples t-test showed a statistically non-significant difference (p=.113 between the means of marginal gap for Shoulder and Chamfer margin designs and the measurements were recorded at 5 predetermined points for the two groups. Conclusions: The Chamfer margin design appeared to offer the same adaptation results as the Shoulder margin design.

  14. Effect of Margin Designs on the Marginal Adaptation of Zirconia Copings

    Science.gov (United States)

    Al Ajmi, Mohammed Ginan; Al Dhafyan, Mohammed; Jomah, Abdulrehman; Abualsaud, Haytham; Almashali, Mazen

    2017-01-01

    Objective The aim of this in vitro study was to investigate the effect of Shoulder versus Chamfer margin design on the marginal adaptation of zirconia (Zr) copings. Materials and Methods 40 extracted molar teeth were mounted in resin and prepared for zirconia crowns with two margin preparation designs (20=Shoulder and 20=Chamfer). The copings were manufactured by Cercon® (DeguDent GmbH, Germany) using the CAD/CAM system for each tooth. They were tried on each tooth, cemented, thermocycled, re-embedded in resin and were subsequently cross sectioned centrally into two equal mesial and distal halves. They were examined under electron microscope at 200 X magnification and the measurements were recorded at 5 predetermined points in micrometers (µm). Results The overall mean marginal gap for the two groups was found to be 206.98+42.78µm with Shoulder margin design (Marginal Gap=199.50+40.72µm) having better adaptation compared to Chamfer (Marginal Gap=214.46+44.85µm). The independent-samples t-test showed a statistically non-significant difference (p=.113) between the means of marginal gap for Shoulder and Chamfer margin designs and the measurements were recorded at 5 predetermined points for the two groups. Conclusions The Chamfer margin design appeared to offer the same adaptation results as the Shoulder margin design. PMID:29225358

  15. Noble metals in ferromanganese crusts from marginal seas of the Northwest Pacific

    Science.gov (United States)

    Astakhova, N. V.

    2017-07-01

    Based on data on the concentration of noble metals (Au, Ag, Pt, Os, Ir, and Ru) in bulk samples of ferromanganese crusts, the presence of inclusions of micro- and nanosized grains of Ag, Au, Pd, and Pt, often with impurities of other elements, as well as their chaotic distribution, three sources of incorporation of these metals into ore crusts of Far Eastern seas are suggested: seawater, postvolcanic gas-hydrothermal fluids, and hydrothermal plumes. The presence of grains of platinoids and gold in ferromanganese crusts on only some mounts may result from peculiarities in the formation of volcanic rocks on the ancient continental basement.

  16. Possible climate preconditioning on submarine landslides along a convergent margin, Nankai Trough (NE Pacific)

    Science.gov (United States)

    Kremer, Katrina; Usman, Muhammed O.; Satoguchi, Yasufumi; Nagahashi, Yoshitaka; Vadakkepuliyambatta, Sunil; Panieri, Giuliana; Strasser, Michael

    2017-12-01

    Submarine landslides are major agents of sediment mass transfer from the shallow to deep sea. Due to their rapid emplacement and tsunamigenic potential, such landslides are significant geohazards for society and off- and on-shore infrastructure. The relationship between climate change and the occurrence of submarine landslides is widely debated. However, there is a lack of continuous long-term submarine landslide records with which to comprehensively understand the relationship between climate-driven forces and submarine landslide occurrence. Here, using oxygen isotope stratigraphy in combination with tephrochronology, we date a 1 Myr continuous record of six landslide deposits (at 13.0-14.2, 323-339, 372-384, 394-413, 508-521, and 857-867 ka) recorded in a slope basin of the Nankai Trough subduction zone, off-shore Japan, which represents the major outcome of this study. The ages of the six landslides coincide mostly with interglacial periods. Thus, we propose that climate forcing might act as a preconditioning factor for slope instability in this active tectonic region.[Figure not available: see fulltext.

  17. Zooplankton Growth, Respiration and Grazing on the Australian Margins of the Tropical Indian and Pacific Oceans.

    Science.gov (United States)

    McKinnon, A David; Doyle, Jason; Duggan, Samantha; Logan, Murray; Lønborg, Christian; Brinkman, Richard

    2015-01-01

    The specific activity of aminoacyl-tRNA synthetases (spAARS), an index of growth rate, and of the electron transport system (spETS), an index of respiration, was measured in three size fractions (73-150 μm, >150 μm and >350 μm) of zooplankton during five cruises to tropical coastal waters of the Kimberley coast (North West Australia) and four cruises to waters of the Great Barrier Reef (GBR; North East Australia). The N-specific biomass of plankton was 3-4-fold higher in the Kimberley than on the GBR in all 3 size classes: Kimberley 1.27, 3.63, 1.94 mg m-3; GBR 0.36, 0.88 and 0.58 mg m-3 in the 73-150 μm, >150 μm and >350 μm size classes, respectively. Similarly, spAARS activity in the Kimberley was greater than that of the GBR: 88.4, 132.2, and 147.6 nmol PPi hr-1 mg protein -1 in the Kimberley compared with 71.7, 82.0 and 83.8 nmol PPi hr-1 mg protein -1 in the GBR, for the 73-150 μm, >150 μm and >350 μm size classes, respectively. Specific ETS activity showed similar differences in scale between the two coasts: 184.6, 148.8 and 92.2 μL O2 hr-1 mg protein-1 in the Kimberley, against 86.5, 88.3 and 71.3 μL O2 hr-1 mg protein-1 in the GBR. On the basis of these measurements, we calculated that >150 μm zooplankton grazing accounted for 7% of primary production in the Kimberley and 8% in GBR waters. Area-specific respiration by >73 μm zooplankton was 7-fold higher in the Kimberley than on the GBR and production by >150 μm zooplankton was of the order of 278 mg C m-2 d-1 in the Kimberley and 42 mg C m-2 d-1 on the GBR. We hypothesize that the much stronger physical forcing on the North West shelf is the principal driver of higher rates in the west than in the east of the continent.

  18. Cordillera Zealandia: A Mesozoic arc flare-up on the palaeo-Pacific Gondwana Margin

    OpenAIRE

    Milan, L. A.; Daczko, N. R.; Clarke, G. L.

    2017-01-01

    Two geochemically and temporally distinct components of the Mesozoic Zealandia Cordilleran arc indicate a shift from low to high Sr/Y whole rock ratios at c. 130?Ma. Recent mapping and a reappraisal of published Sr-Nd data combined with new in-situ zircon Hf isotope analyses supports a genetic relationship between the two arc components. A reappraisal of geophysical, geochemical and P-T estimates demonstrates a doubling in thickness of the arc to at least 80?km at c. 130?Ma. Contemporaneously...

  19. Cordillera Zealandia: A Mesozoic arc flare-up on the palaeo-Pacific Gondwana Margin.

    Science.gov (United States)

    Milan, L A; Daczko, N R; Clarke, G L

    2017-03-21

    Two geochemically and temporally distinct components of the Mesozoic Zealandia Cordilleran arc indicate a shift from low to high Sr/Y whole rock ratios at c. 130 Ma. Recent mapping and a reappraisal of published Sr-Nd data combined with new in-situ zircon Hf isotope analyses supports a genetic relationship between the two arc components. A reappraisal of geophysical, geochemical and P-T estimates demonstrates a doubling in thickness of the arc to at least 80 km at c. 130 Ma. Contemporaneously, magmatic addition rates shifted from ~14 km 3 /my per km of arc to a flare-up involving ~100 km 3 /my per km of arc. Excursions in Sr-Nd-Hf isotopic ratios of flare-up rocks highlight the importance of crust-dominated sources. This pattern mimics Cordilleran arcs of the Americas and highlights the importance of processes occurring in the upper continental plates of subduction systems that are incompletely reconciled with secular models for continental crustal growth.

  20. Marginal and happy? The need for uniqueness predicts the adjustment of marginal immigrants.

    Science.gov (United States)

    Debrosse, Régine; de la Sablonnière, Roxane; Rossignac-Milon, Maya

    2015-12-01

    Marginalization is often presented as the strategy associated with the worst adjustment for immigrants. This study identifies a critical variable that buffers marginal immigrants from the negative effects of marginalization on adjustment: The need for uniqueness. In three studies, we surveyed immigrants recruited on university campuses (n = 119, n = 116) and in the field (n = 61). Among marginal immigrants, a higher need for uniqueness predicted higher self-esteem (Study 1), affect (Study 2), and life satisfaction (Study 3), and marginally higher happiness (Study 2) and self-esteem (Study 3). No relationship between the need for uniqueness and adjustment was found among non-marginal immigrants. The adaptive value of the need for uniqueness for marginal immigrants is discussed. © 2015 The British Psychological Society.

  1. {sup 210}Pb and {sup 210}Po as tracers of particle transport mechanisms on continental margins

    Energy Technology Data Exchange (ETDEWEB)

    Radakovitch, O.; Heussner, S. [Perpignan Univ., 66 (France). Lab. de Sedimentologie et Geochimie Marines; Biscaye, P.; Abassi, A. [Columbia Univ., Palisades, NY (United States). Lamont Doherty Earth Observatory

    1997-12-31

    The natural radionuclides {sup 210}Po and {sup 210}Pb, members of the {sup 238}U decay chain, are particularly helpful to the understanding of particle transport processes in the ocean. These isotopes were analysed on sediment trap particles collected during 3 one-year experiments on continental margins. In the Bay of Biscay (Northeastern Atlantic) and in the Gulf of Lion (Northwestern Mediterranean Sea) both as part of the French ECOMARGE programme, and in the Middle Atlantic Bight (Northwestern Atlantic) as part of the SEEP programme. They yielded great insights into scenarios of particle transfer at each site, mainly based on the spatial and temporal distribution of {sup 210}Pb particulate concentrations and fluxes. (author) 11 refs.

  2. EX1204: Northeastern Canyons and Continental Margins Exploration on NOAA Ship Okeanos Explorer between 20120529 and 20120613

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During the Okeanos Explorer (EX) mission EX1204, the vessel will sail from Norfolk, VA, along the continental shelf break of the U.S. East Coast from Virginia to...

  3. Uranium concentrations in groundwater, northeastern Washington

    Science.gov (United States)

    Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

    2018-04-18

    A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to

  4. The influence of the Interdecadal Pacific Oscillation on Temperature and Precipitation over the Globe

    Science.gov (United States)

    Dong, Bo; Dai, Aiguo

    2015-11-01

    The Interdecadal Pacific Oscillation (IPO) is a 40-60 year quasi-oscillation seen mostly in the Pacific basin, but its impacts on surface temperature (T) and precipitation (P) have been found over Australia, the Southwest U.S. and other regions. Here, a global analysis of IPO's impacts on T and P and its modulation of ENSO's influence on T and P over the globe is performed using observational and reanalysis data and model simulations. Since 1920, there are two warm (1924-1944 and 1977-1998) and two cold (1945-1976 and 1999-present) IPO phases, whose change is associated with abrupt shifts in North Pacific sea level pressure (SLP) and contrasting anomaly patterns in T and P and atmospheric circulation over the eastern and western Pacific. The IPO explains more than half of the interdecadal variations in T and P over many regions, such as northeastern Australia, western Canada and northern India. Significant correlations between the IPO and local P are observed over eastern Australia, southern Africa and the Southwest U.S. The IPO also modulates ENSO's influence on local T and P over most of these regions. T over northern India is positively correlated with Niño3.4 ENSO index during cold IPO phases but the correlation turns negative or insignificant during IPO warm phases. Over northeastern Australia, the T versus ENSO and P versus ENSO correlations are stronger during the IPO cold phases than during the warm phases. The P versus ENSO correlation over southern Africa tends to be negative during IPO warm phases but becomes weaker or insignificant during IPO cold phases. The IPO-induced P anomalies can be explained by the associated anomaly circulation, which is characterized by a high SLP center and anti-cyclonic flows over the North Pacific, and negative SLP anomalies and increased wind convergence over the Indonesia and western Pacific region during IPO cold phases. These observed influences of the IPO on regional T and P are generally reproduced by an atmospheric

  5. Pacific Proving Grounds radioisotope imprint in the Philippine Sea sediments.

    Science.gov (United States)

    Pittauer, Daniela; Roos, Per; Qiao, Jixin; Geibert, Walter; Elvert, Marcus; Fischer, Helmut W

    2018-06-01

    Radionuclide concentrations were studied in sediment cores taken at the continental slope of the Philippine Sea off Mindanao Island in the equatorial Western Pacific. High resolution deposition records of anthropogenic radionuclides were collected at this site. Excess 210 Pb together with excess 228 Th and anthropogenic radionuclides provided information about accumulation rates. Concentrations of Am and Pu isotopes were detected by gamma spectrometry, alpha spectrometry and ICP-MS. The Pu ratios indicate a high portion (minimum of 60%) of Pu from the Pacific Proving Grounds (PPG). This implies that the transport of PPG derived plutonium with the Mindanao Current southward is similarly effective as the previously known transport towards the north with the Kuroshio Current. The record is compared to other studies from northwest Pacific marginal seas and Lombok basin in the Indonesian Archipelago. The sediment core top was found to contain a 6 cm thick layer dominated by terrestrial organic matter, which was interpreted as a result of the 2012 Typhoon Pablo-related fast deposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Marine birds and mammals of the Pacific Subarctic Gyres

    Science.gov (United States)

    Springer, A.M.; Piatt, John F.; Shuntov, V.P.; Van Vliet, Gus B.; Vladimirov, V.L.; Kuzin, A.E.; Perlov, A.S.

    1999-01-01

    The importance of the subarctic gyres of the North Pacific Ocean to marine birds and mammals is poorly known because of a paucity of data spanning appropriate scales of time and space. The little information that is available indicates the western subarctic gyre (WSAG) is more productive than the eastern subarctic gyre (ESAG). In summer the WSAG supports a greater density and higher biomass of seabirds than the ESAG, including at least two species that are more abundant at nesting colonies in the eastern subarctic. Perhaps most revealing of the seabird distributions in this regard is that of southern hemisphere shearwaters (Puffinus spp.) that overwinter in the North Pacific. Their biomass is an order of magnitude greater than that of any northern hemisphere species and is three-fold greater in the WSAG than in the ESAG. Several species of cetaceans also appear to be, or to have been prior to commercial depletions, more abundant in the WSA. Among the many prey species consumed by marine birds and mammals, squids and fishes in the family Myctophidae predominate overall. Other forage species, notably euphausiids, Pacific saury (Cololabis saira) and Atka mackerel (Pleurogrammus monopterygius) are important at times to certain species. The principal exceptions to this generalization are baleen whales and small seabirds that consume zooplankton. Interannual and decadal-scale variability in the physical environment and food web production affect seabirds and marine mammals at sea and at coastal breeding locations around the margins of the gyres.

  7. Pacific Studies: Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Anne Holden Rønning

    2014-02-01

    Full Text Available Looking back to the past this paper discusses why Pacific studies and in particular Australasian studies became an area of interest in tertiary education in Europe. What subject areas initiated these studies, and how do past legacies shape the present? With cutbacks in higher education over the past two decades the future of interdisciplinary studies and the humanities looks bleak. At the same time due to global business and increased political communication across borders there is a vibrant interest in and need for such studies among businesses and students. For most Europeans the literature of settler countries, with their European legacy, makes access to ways of thought and culture easier than studies of countries with other mythological backgrounds. In today’s multicultural environment such studies can provide knowledge for an understanding of other cultures and increase tolerance of the ‘other’. Area studies have relevance to our situation in Europe with increased migrancy, not least as a result of Schengen and EU regulations.

  8. Periodontal conditions of elders in Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria Vieira de Lima Saintrain

    2015-12-01

    Full Text Available Objective: To evaluate the periodontal conditions of elderly patients assisted in a Specialized Dentistry Center in Northeastern of Brazil. Methods: Quantitative and cross-sectional study conducted with 152 elders. It was used a questionnaire to get information about socio-demographic aspects (age, sex, gender, income, and education, general healthand periodontal clinical examination based on the Communitarian Periodontal Index (CPI, an indicator recommended by the World Health Organization (WHO, who enabled the evaluation of the periodontal condition. It was used Pearson’s Chi-square Distribution, or Fisher’s Exact Test, with significance level tests 5%. Results: The elders age ranged from 60 to 89 years, mean of 67.6 years (SD ± 6.13. The variables female 70 (53.9%, retiree 95 (62.5%, low income 91 (59.0%, secondary school 60 (39.5% predominated and 130 (85.5% elders used medicines. Most evidenced self-reported diseases: eye problems 123 (80.9%, cardiovascular disorders 107 (70.4%, osteoporosis 77 (50.7% and diabetes 54 (35.5%. Dental calculus prevailed 128 (84.2%. Statistical significance was found between the presence ofperiodontal pocket and age group 60-65 years (p= 0.027; dental calculus andbrushing teeth once a day (p=0.028; not use of dental floss and periodontal pocket from 4 to 5mm (p=0.001; use of toothpick with periodontal pocket from 4 to 5mm (0.018 and of 6mm or more (p=0.001; educational level and dental calculus (p=0.005. Conclusion: The periodontal health of this population is covered with precariousness, mainly due to dental calculus and periodontal pocket.

  9. Warm Water Pathways in the Northeastern North Atlantic ACCE RAFOS Float Data Report

    National Research Council Canada - National Science Library

    Furey, Heather

    2001-01-01

    ...). The RAFOS float component of ACCE, entitled "Warm Water Pathways and Intergyre Exchange in the Northeastern North Atlantic", was designed to measure the warm water currents entering the northeastern...

  10. Evolution of the Mariana Convergent Plate Margin System

    Science.gov (United States)

    Fryer, Patricia

    1996-02-01

    The Mariana convergent plate margin system of the western Pacific provides opportunities for studying the tectonic and geochemical processes of intraoceanic plate subduction without the added complexities of continental geology. The system's relative geologic simplicity and the well-exposed sections of lithosphere in each of its tectonic provinces permit in situ examination of processes critical to understanding subduction tectonics. Its general history provides analogs to ancient convergent margin terranes exposed on land and helps to explain the chemical mass balance in convergent plate margins. The Mariana convergent margin's long history of sequential formation of volcanic arcs and extensional back arc basins has created a series of volcanic arcs at the eastern edge of the Philippine Sea plate. The trenchward edge of the overriding plate has a relatively sparse sediment cover. Rocks outcropping on the trench's inner slope are typical of the early formed suprasubduction zone's lithosphere and have been subjected to various processes related to its tectonic history. Pervasive forearc faulting has exposed crust and upper mantle lithosphere. Many large serpentinized peridotite seamounts are within 100 km of the trench axis. From these we can learn the history of regional metamorphism and observe and sample active venting of slab fluids. Ocean drilling recovered suprasubduction zone lava sequences erupted since the Eocene that suggest that the forearc region remains volcanologically dynamic. Seismic studies and seafloor mapping show evidence of deformation throughout forearc evolution. Large portions of uplifted southern forearc are exposed at the larger islands. Active volcanoes at the base of the eastern boundary fault of the Mariana Trough vary in size and composition along strike and record regional differences in source composition. Their locations along strike of the arc are controlled in part by cross-arc structures that also facilitate formation of submarine

  11. (Tele)presenting Secrets from the Deep Southern California Margin

    Science.gov (United States)

    Levin, L. A.; Girguis, P. R.; Brennan, M.; German, C. R.; Raineault, N.; Le, J. T.; Grupe, B.; Gallo, N.; Inderbitzen, K. E.; Tuzun, S.; Wagner, J.

    2016-02-01

    This past summer scientists, students and the public participated through telepresence in 2 weeks of deep-sea exploration via the EV Nautilus, visiting a tremendous diversity of sites found along the southern California continental margin (200-900m). We observed previously unknown cold seeps; new and unexpected assemblages and species distributions; and novel animal behaviors; all under the overarching influence of strong oxygen gradients from the East Pacific oxygen minimum zone (OMZ). The expedition discovered four new methane seep sites, each with distinct biota reflecting varying depth and oxygen levels. OMZ specialists such as lucinid clams, hagfish, and thornyhead fishes coexisted with seep biota (vesicoymid clams) at a 1.4-km long seep off Point Dume (Malibu, CA), forming a blended ecosystem with distinct zonation. A range of habitats (canyons, knolls, mounds) within the OMZ hosted fish, crustacean, echinoderm and cnidarian species with unusual hypoxia tolerance to < 3 µM O2 or lower. Organic falls (a sunken whale and naturally occurring kelp holdfasts) hosted many invertebrates and served as clear magnets for scavengers and predators. In situ observations revealed unusual behaviors including "parasailing" snails and drifting benthic siphonophores in the Santa Monica Basin, fish aggregating at seep carbonates, and cruising catsharks and their egg cases at methane seeps. Many of these observations advance understanding of the ecosystem services provided by deep-sea, margin habitats, while stimulating public interest in ocean exploration. Telepresence permitted broad engagement of students and scientists from as near as Los Angeles and as far as South Africa, as well as meaningful interactions with the public. In situ exploration and observation can and will play increasingly important roles in environmental management of the deep ocean as disturbance from resource extraction and climate change intensify.

  12. Pb-Nd Isotopes Indicate the Origin of Island Arc Terranes in the Early Paleozoic Pacific.

    Science.gov (United States)

    Münker

    2000-03-01

    The Takaka Terrane in New Zealand is one of the best exposed arc fragments of the early Paleozoic Australian-Antarctic convergent margin and constitutes one of the most outboard terranes of this margin in paleogeographic reconstructions. Pb-Nd isotope compositions of clinopyroxenes from the Cambrian Devil River Volcanics of the Takaka Terrane enable identification of the location of the terrane in the Paleo-Pacific Ocean. The Devil River Volcanics, a suite of primitive arc and back-arc rocks, are interbedded with the partly continent-derived Haupiri Group sediments. Extremely radiogenic Pb and unradiogenic Nd compositions in the arc rocks cannot be explained by assimilation of the Haupiri Group sediments or a continental basement of such a composition. Pb isotope compositions of the Takaka Terrane sediments are much less radiogenic and overlap with crustal compositions of the Lachlan Fold Belt in Australia, suggesting that both units are derived from one source, the Australian-Antarctic Pacific margin. Pb-Nd isotope compositions in the Devil River Volcanics reflect contamination of their mantle sources by subducted sediments derived from Archean provinces in either Antarctica or Laurentia. Both provinces show characteristically high 207Pb/204Pb500 and were located at the Pacific rim in the Cambrian. Mixing between mantle and Proterozoic continental material from present western South America or eastern Laurentia cannot explain the high 207Pb/204Pb500 in the New Zealand rocks. As in New Zealand, extreme spreads in Pb-Nd isotope compositions in other Cambrian volcano-sedimentary sequences in southeast Australia and Tasmania can be explained by the same model, suggesting that all these fragments originated along the Australian-Antarctic Gondwana margin. Pb isotope compositions of arc rocks, therefore, provide a new tool for terrane analysis in the early Paleozoic Pacific ocean.

  13. The public view of Pacific Northwest forests

    International Nuclear Information System (INIS)

    West, P.R.

    1991-01-01

    There are diverse communities that make up the public in the Pacific Northwest, all with differing views on the forest. To the media, the public are those indirect stakeholders, or average citizens, who have become keenly aware of the importance of environmental issues, including the implications for global change. Linkages between the forests, deforestation, global climate change, and overall environmental sustainability have been widely publicized, though less frequently analyzed in depth. Consequently, the state of Northwest forests has become a vital public interest. The need for an overall margin of global environmental security, and a concern over unsuspected consequences of all economic activity (including forestry) have created a community of interest among the urban population. In part, this is a spillover effect from promoting individual environmental responsibility and the conserver ethic into issues beyond the city boundary. In the Northwest, this often translates as a deep concern over forest management issues and strong conviction that changes are needed. At the same time, and largely as a direct response, the socioeconomic interests of rural forest communities have become a high-profile issue, raising debate over local empowerment and local forest stewardship models. The consequences of this complex and rapidly evolving public view of the forests are critical to forest managers and policymakers. 12 refs

  14. Mental Depreciation and Marginal Decision Making

    Science.gov (United States)

    Heath; Fennema

    1996-11-01

    We propose that individuals practice "mental depreciation," that is, they implicitly spread the fixed costs of their expenses over time or use. Two studies explore how people spread fixed costs on durable goods. A third study shows that depreciation can lead to two distinct errors in marginal decisions: First, people sometimes invest too much effort to get their money's worth from an expense (e.g., they may use a product a lot to spread the fixed expense across more uses). Second, people sometimes invest too little effort to get their money's worth: When people add a portion of the fixed cost to the current costs, their perceived marginal (i.e., incremental) costs exceed their true marginal costs. In response, they may stop investing because their perceived costs surpass the marginal benefits they are receiving. The latter effect is supported by two field studies that explore real board plan decisions by university students.

  15. Exploration of the continental margins of India

    Digital Repository Service at National Institute of Oceanography (India)

    Siddiquie, H.N.; Hashimi, N.H.; Vora, K.H.; Pathak, M.C.

    In mid 1970's the National Institute of Oceanography, Goa, India prepared a plan for systematic regional, geological and geophysical surveys of the continental margins of India. This involved over 75,000 km of underway (bathymetric, side scan sonar...

  16. POTENTIAL OVERLOOKED ANALOGUES TO THE INDIAN OCEAN TSUNAMI IN THE WESTERN AND SOUTHWESTERN PACIFIC

    Directory of Open Access Journals (Sweden)

    Daniel A. Walker

    2006-01-01

    Full Text Available In a more detailed examination of subducting margins of the Western and Southwestern Pacific, segments are found that are similar to the segment along the Indian Ocean that ruptured on 26 December 2004. Similarities are found in terms of hypocenter distributions and historical seismicity. The largest reported moment magnitudes in the Western and Southwestern Pacific since 1900 were an 8.5, an 8.4, and an 8.3. Should any substantially larger earthquakes occur along these segments or elsewhere in the Western or Southwestern Pacific, Civil Defense agencies in the Hawaiian Islands should be aware of any possible inadequacies in existing evacuation procedures for western and southern shores.

  17. Initiation of Extension in South China Continental Margin during the Active-Passive Margin Transition: Thermochronological and Kinematic Constraints

    Science.gov (United States)

    Zuo, X.; Chan, L. S.

    2015-12-01

    The South China continental margin is characterized by a widespread magmatic belt, prominent NE-striking faults and numerous rifted basins filled by Cretaceous-Eocene sediments. The geology denotes a transition from active to passive margin, which led to rapid modifications of crustal stress configuration and reactivation of older faults in this area. Our zircon fission-track data in this region show two episodes of exhumation: The first episode, occurring during 170-120Ma, affected local parts of the Nanling Range. The second episode, a more regional exhumation event, occurred during 115-70Ma, including the Yunkai Terrane and the Nanling Range. Numerical geodynamic modeling was conducted to simulate the subduction between the paleo-Pacific plate and the South China Block. The modeling results could explain the fact that exhumation of the granite-dominant Nanling Range occurred earlier than that of the gneiss-dominant Yunkai Terrane. In addition to the difference in rock types, the heat from Jurassic-Early Cretaceous magmatism in Nanling may have softened the upper crust, causing the area to exhume more readily than Yunkai. Numerical modeling results also indicate that (1) high lithospheric geothermal gradient, high slab dip angle and low convergence velocity favor the reversal of crustal stress state from compression to extension in the upper continental plate; (2) late Mesozoic magmatism in South China was probably caused by a slab roll-back; and (3) crustal extension could have occurred prior to the cessation of plate subduction. The inversion of stress regime in the continental crust from compression to crustal extension imply that the Late Cretaceous-early Paleogene red-bed basins in South China could have formed during the late stage of the subduction, accounting for the occurrence of volcanic events in some sedimentary basins. We propose that the rifting started as early as Late Cretaceous, probably before the cessation of subduction process.

  18. Dynamics of the Pacific Northwest Lithosphere and Asthenosphere

    Science.gov (United States)

    Humphreys, E.

    2013-12-01

    Seismic imaging resolves a complex structure beneath the Pacific Northwest (PNW) that is interpreted as: an high-velocity piece of accreted (~50 Ma) Farallon lithosphere that deepens from being exposed (at coast, where it is called Siletzia) to lower crust in SE Washington and then descending vertically to ~600 km as a 'curtain' beneath central Idaho; a stubby Juan de Fuca slab (to Sierra Nevada driving the PNW into British Columbia; this push, and oblique subduction, are responsible for PNW clockwise rotation. Modeled (in 2D, map view) north-directed tractions on the Cascadia mega-thrust average ~4 TN per meter of along-strike fault length, or probably a shear stress of ~40 MPa over much of the locked mega-thrust (i.e., much more shear stress than the typical earthquake stress drop of 1-10 MPa). Normal to the coast, southern Cascadia is relatively tensional (where margin-normal compression is less than typical ridge push by ~4 TN/m of along-strike fault length) whereas northern Cascadia is compressional. This indicates that the southern Cascadia mega-thrust is more weakly coupled than the northern mega-thrust. Southern Cascadia slab rollback and extension of the Cascade graben and Basin-and-Range are enabled by the weak coupling, in conjunction with high gravitational potential energy of the southern Oregon arc and back-arc. Juan de Fuca-Gorda lithosphere experiences the same stress on its eastern margin as North America does on the PNW Cascadia margin (by stress continuity), although current models of the individual plates do not show this continuity. Gorda plate is strongly compressed across the Mendocino transform by the north-moving Pacific Plate. Development of the NW-trending Blanco transform has created a fault that avoids this strong compression.

  19. Investigating mechanisms for the variability in phytoplankton assemblages in the northeastern waters of the Philippines

    Science.gov (United States)

    Yniguez, A. T.; Camoying, M.; Bollozos, I.; Palermo, J. H.; Villanoy, C. L.

    2013-12-01

    The northeastern side of the Philippines, particularly off of Luzon Island, is strongly influenced by the Pacific Western Boundary current system. The North Equatorial Current bifurcates offshore feeding into the Mindanao current flowing south and the Kuroshio Current that begins to consolidate in the waters off of Luzon. Two cruises were conducted during May/June 2011 and April/May 2012 which showed distinctly different circulation patterns and strengths of water masses. Phytoplankton abundances and composition measurements were obtained using microscopy, as well as through an in situ fluorometer. Analysis of the phytoplankton assemblages from these two cruises showed variability in both space and time. Distinct assemblages could be observed amongst different water masses both in 2011 and 2012. There was also a significant difference in the phytoplankton abundances and composition seen between the two sampling years. Mechanisms such as circulation patterns and related physico-chemical characteristics leading to these spatio-temporal variabilities in phytoplankton concentrations and distributions are explored in this study. These shifts in primary producers and productivity have important implications in this region which is a key fishing area for both municipal and commercial fisheries.

  20. Confirmation of the presence of Janicea antiguensis (Chace, 1972 (Decapoda: Barbouriidae in northeastern and eastern Brazil

    Directory of Open Access Journals (Sweden)

    Bruno W. Giraldes

    Full Text Available The barbouriid shrimp Janicea antiguesis (Chace, 1972 is reported from Porto de Galinhas and Tamandaré in Pernambuco and Guarapari in Espírito Santo, Brazil. These records confirm the presence of J. antiguensis in northeastern and eastern Brazil, considerably extending its Brazilian range from Fernando de Noronha to southern Espírito Santo and also representing the first record of this species from mainland coastal reefs. In Brazil, J. antiguensis occurs in or near marine reef caves, typically at depths between 5 and 15 m, and can be most easily observed while scuba diving at night. Colour photographs of J. antiguensis from various Atlantic localities are provided and its colour pattern is compared to that of the closely related Indo-West Pacific barbouriid shrimp, Parhippolyte misticia (Clark, 1989. Some in situ observations are provided for the Porto de Galinhas population of J. antiguensis. Multiple observations of pairs with both individuals brooding embryos at different developmental stages suggest protandric simultaneous hermaphroditism in J. antiguensis.

  1. Marketing margins and agricultural technology in Mozambique

    DEFF Research Database (Denmark)

    Arndt, Channing; Jensen, Henning Tarp; Robinson, Sherman

    2000-01-01

    Improvements in agricultural productivity and reductions in marketing costs in Mozambique are analysed using a computable general equilibrium (CGE) model. The model incorporates detailed marketing margins and separates household demand for marketed and home-produced goods. Individual simulations...... of improved agricultural technology and lower marketing margins yield welfare gains across the economy. In addition, a combined scenario reveals significant synergy effects, as gains exceed the sum of gains from the individual scenarios. Relative welfare improvements are higher for poor rural households...

  2. In silico particle margination in blood flow

    OpenAIRE

    Müller, Kathrin

    2015-01-01

    A profound knowledge of margination, the migration of blood components to the vessel wall in blood flow, is required in order to understand the genesis of various diseases, as e.g., cardiovascular diseases or bleeding disorders. Margination of particles is a pre-condition for potential adhesion. Adhesion to the vessel wall is required for platelets, the protein von Willebrand factor (VWF), but also for drug and imaging agent carriers in order to perform their particular tasks. In the haemosta...

  3. Northeastern Regional Environmental Characterization Report. Executive summary. Final report

    International Nuclear Information System (INIS)

    1985-08-01

    This Executive Summary of the final Northeastern Regional Environmental Characterization Report (RECR) is issued primarily for public information purposes and provides a general overview of the report. The complete RECR presents available regional environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. For each of the states within the Northeastern Region, information is provided on the environmental disqualifying factors and the environmental regional screening variables to be used in region-to-area screening

  4. An evaluation of the bedrock aquifer system in northeastern Wisconsin

    Science.gov (United States)

    Emmons, P.J.

    1987-01-01

    Ground water is a major source of water in northeastern Wisconsin. The lower Fox River valley, located between Lake Winnebago and Green Bay in northeastern Wisconsin, is the second largest population center in Wisconsin. By 1957, ground-water withdrawals had lowered the potentiometric surface of the aquifer system as much as 440 feet below prepumping levels. With the exception of the city of Green Bay, which converted from ground water to surface water (Lake Michigan) for their municipal water supply in 1957, ground-water withdrawals have continually increased.

  5. Northeastern Regional Geologic Characterization Report: executive summary. Final report

    International Nuclear Information System (INIS)

    1985-08-01

    This Executive Summary of the final Northeastern Regional Geologic Characterization Report (RGCR) is issued primarily for public information purposes and provides a general overview of the report. The complete RGCR presents available regional geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. For each of the states within the Northeastern Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. 5 refs., 3 figs

  6. The Continental Margin of East Asia: a collage of multiple plates formed by convergence and extension from multiple directions

    Science.gov (United States)

    Mao, J.; Wang, T.; Ludington, S.; Qiu, Z.; Li, Z.

    2017-12-01

    East Asia is one of the most complex regions in the world. Its margin was divided into 4 parts: Northeast Asia, North China, South China and Southeast Asia. During the Phanerozoic, continental plates of East Asia have interacted successively with a) the Paleo Tethyan Ocean, b) the Tethyan and Paleo Pacific Oceans and c) the Pacific and Indian. In the Early Mesozoic, the Indosinian orogeny is characterized by the convergence and extension within multiple continental plates, whereas the Late Mesozoic Yanshanian orogeny is characterized by both convergence and compression due to oceanic subduction and by widespread extension. We propose this combination as "East Asia Continental Margin type." Except in Northeast Asia, where Jurassic and Cretaeous accretionary complexes are common, most magmatic rocks are the result of reworking of ancient margins of small continental plates; and oceanic island arc basalts and continental margin arc andesites are largely absent. Because South China is adjacent to the western margin of the Pacific Plate, some effects of its westward subduction must be unavoidable, but juvenile arc-related crust has not been identified. The East Asian Continental Margin is characterized by magmatic rocks that are the result of post-convergent tectonics, which differs markedly from the active continental margins of both South and North America. In summary, the chief characteristics of the East Asian Continental Margin are: 1) In Mesozoic, the periphery of multiple blocks experienced magmatism caused by lithospheric delamination and thinning in response to extension punctuated by shorter periods of convergence. 2) The main mechanism of magma generation was the partial melting of crustal rocks, due to underplating by upwelling mafic magma associated with the collapse of orogenic belts and both extension and compression between small continental blocks. 3) During orogeny, mostly high Sr/Y arc-related granitoids formed, whereas during post-orogenic times, A

  7. Professional Commitment and Professional Marginalism in Teachers

    Directory of Open Access Journals (Sweden)

    Kalashnikov A.I.

    2017-11-01

    Full Text Available The article reviews teachers' attitudes towards the teaching profession which can be expressed both in professional commitment and in professional marginalism. The dominance of professional marginalism could affect destructively the students as well as the teacher’s personality, hence the issues related to the content of personal position of a marginal and the rate of marginalism among teachers. It was suggested that marginalism could be revealed in the study of professional commitment. The study involved 81 teachers of Sverdlovsk secondary schools aged 21—60 years with work experience ranging from 1 month to 39 years. The Professional Commitment Questionnaire was used as the study technique. The results showed that negative emotional attitude towards the profession and reluctance to leave the profession were grouped as a separate factor. The dispersion factor was 12,5%. The factor loadings ranged from 0.42 to 0.84. The study proved that professional marginalism in teachers includes dissatisfaction with work, feelings of resentment against profession and an unwillingness to leave the profession.

  8. NRC Seismic Design Margins Program Plan

    International Nuclear Information System (INIS)

    Cummings, G.E.; Johnson, J.J.; Budnitz, R.J.

    1985-08-01

    Recent studies estimate that seismically induced core melt comes mainly from earthquakes in the peak ground acceleration range from 2 to 4 times the safe shutdown earthquake (SSE) acceleration used in plant design. However, from the licensing perspective of the US Nuclear Regulatory Commission, there is a continuing need for consideration of the inherent quantitative seismic margins because of, among other things, the changing perceptions of the seismic hazard. This paper discusses a Seismic Design Margins Program Plan, developed under the auspices of the US NRC, that provides the technical basis for assessing the significance of design margins in terms of overall plant safety. The Plan will also identify potential weaknesses that might have to be addressed, and will recommend technical methods for assessing margins at existing plants. For the purposes of this program, a general definition of seismic design margin is expressed in terms of how much larger that the design basis earthquake an earthquake must be to compromise plant safety. In this context, margin needs to be determined at the plant, system/function, structure, and component levels. 14 refs., 1 fig

  9. A database of paleoceanographic sediment cores from the North Pacific, 1951-2016

    Science.gov (United States)

    Borreggine, Marisa; Myhre, Sarah E.; Mislan, K. Allison S.; Deutsch, Curtis; Davis, Catherine V.

    2017-09-01

    We assessed sediment coring, data acquisition, and publications from the North Pacific (north of 30° N) from 1951 to 2016. There are 2134 sediment cores collected by American, French, Japanese, Russian, and international research vessels across the North Pacific (including the Pacific subarctic gyre, Alaskan gyre, Japan margin, and California margin; 1391 cores), the Sea of Okhotsk (271 cores), the Bering Sea (123 cores), and the Sea of Japan (349 cores) reported here. All existing metadata associated with these sediment cores are documented here, including coring date, location, core number, cruise number, water depth, vessel metadata, and coring technology. North Pacific sediment core age models are built with isotope stratigraphy, radiocarbon dating, magnetostratigraphy, biostratigraphy, tephrochronology, % opal, color, and lithological proxies. Here, we evaluate the iterative generation of each published age model and provide comprehensive documentation of the dating techniques used, along with sedimentation rates and age ranges. We categorized cores according to the availability of a variety of proxy evidence, including biological (e.g., benthic and planktonic foraminifera assemblages), geochemical (e.g., major trace element concentrations), isotopic (e.g., bulk sediment nitrogen, oxygen, and carbon isotopes), and stratigraphic (e.g., preserved laminations) proxies. This database is a unique resource to the paleoceanographic and paleoclimate communities and provides cohesive accessibility to sedimentary sequences, age model development, and proxies. The data set is publicly available through PANGAEA at https://doi.org/10.1594/PANGAEA.875998.

  10. A database of paleoceanographic sediment cores from the North Pacific, 1951–2016

    Directory of Open Access Journals (Sweden)

    M. Borreggine

    2017-09-01

    Full Text Available We assessed sediment coring, data acquisition, and publications from the North Pacific (north of 30° N from 1951 to 2016. There are 2134 sediment cores collected by American, French, Japanese, Russian, and international research vessels across the North Pacific (including the Pacific subarctic gyre, Alaskan gyre, Japan margin, and California margin; 1391 cores, the Sea of Okhotsk (271 cores, the Bering Sea (123 cores, and the Sea of Japan (349 cores reported here. All existing metadata associated with these sediment cores are documented here, including coring date, location, core number, cruise number, water depth, vessel metadata, and coring technology. North Pacific sediment core age models are built with isotope stratigraphy, radiocarbon dating, magnetostratigraphy, biostratigraphy, tephrochronology, % opal, color, and lithological proxies. Here, we evaluate the iterative generation of each published age model and provide comprehensive documentation of the dating techniques used, along with sedimentation rates and age ranges. We categorized cores according to the availability of a variety of proxy evidence, including biological (e.g., benthic and planktonic foraminifera assemblages, geochemical (e.g., major trace element concentrations, isotopic (e.g., bulk sediment nitrogen, oxygen, and carbon isotopes, and stratigraphic (e.g., preserved laminations proxies. This database is a unique resource to the paleoceanographic and paleoclimate communities and provides cohesive accessibility to sedimentary sequences, age model development, and proxies. The data set is publicly available through PANGAEA at https://doi.org/10.1594/PANGAEA.875998.

  11. AHP 27: A Northeastern Tibetan Childhood

    Directory of Open Access Journals (Sweden)

    Tsering Bum ཚེ་རིང་འབུམ།

    2013-12-01

    Full Text Available Tsering Bum (b. 1985 describes his early life in Amdo in terms of dreams, herding, punishment from a lama, schooling experiences, attending a Kalachakra teaching, a lhatzi gathering, irrigation, his grandfather, archery, and other important moments and influences. Another incredible production from Kevin Stuart's Tibetan English students! Tsering Bum gives us a series of intricately woven vignettes of his childhood and adolescence in a small Tibetan village in Qinghai Province. A Northeastern Tibetan Childhood takes readers into the social and material culture of Tsering's family and fellow villagers. We begin with a home scene on the heated brick hyitsi 'bed', where the family sleeps, meals are taken, and guests are entertained. Through Tsering's writing we taste the noodles his mother makes by hand, know the life of the herders, meet ritualists who communicate with the mountain deity, visit a Kalachakra for blessings, experience an archery contest that ends in singing and drink, swim naked in cold mountain rivers, celebrate Losar, or Tibetan new year festival, visit a nomad festival, enter the transformative world of a county primary school, and hear the accounts of three deaths. The stories take us through a landscape of mountains, rivers, and grasslands to new worlds that for the narrator end with a kindled sense of global vision and self-worth. Mark Bender, Ohio State University I highly recommend this exciting new work. Tsering Bum's account of his life is a quick and pleasant read, full of insights into many aspects of contemporary Tibetan culture. From village rituals associated with death and archery contests to the challenges of modern schooling in rural areas, Tsering Bum leads us quickly through a narrative that links past and present to hopes for the future. Tibetan Buddhism and mountain pilgrimage play a limited but significant role in the story. As a historian, I was most interested in the chapter 'Grandpa' that recounts the

  12. Origins of the Salado, Seven Rivers, and San Andres salt margins in Texas and New Mexico: Revision 1: Topical report

    International Nuclear Information System (INIS)

    Boyd, S.D.; Murphy, P.J.

    1987-02-01

    The present boundaries of the San Andres, Seven Rivers, and Salado salts generally lie along the periphery of the Palo Duro and Tucumcari Basins. Various geologic mechanisms occurring singularly or in combination determined the positions of the salt margins. These mechanisms include nondeposition of salt and syndepositional and postdepositional dissolution. In New Mexico, San Andres units pinch out against the Pedernal and Sierra Grande Uplifts, indicating that nondeposition established the original salt margins there. Syndepositional dissolution of exposed Upper San Andres salts occurred in response to Guadalupian upwarp of the basin margins. Triassic erosion differentially removed Permian salt-bearing formations along the uplifts. Late Tertiary dissolution is indicated by fill of north-south trending collapse valleys. In Texas, Guadalupian upwarp along the Amarillo Uplift caused pinchout of Units 2 and 3 in the Lower San Andres and influenced the deposition of subsequent salt-bearing strata. The discontinuity of Upper San Andres evaporites across the Amarillo Uplift suggests syndepositional dissolution. Along the eastern and northeastern basin margin, dissolution may have accompanied Triassic erosion of locally uplifted Upper Permian strata. Tertiary dissolution is recognized beneath anomalously thick Ogallala Formation sections that overlie collasped Permian strata. 49 refs., 31 figs., 2 tabs

  13. Influence of a proximal margin elevation technique on marginal adaptation of ceramic inlays.

    Science.gov (United States)

    Zaruba, M; Göhring, T N; Wegehaupt, F J; Attin, T

    2013-03-01

    Evaluating the effect of a proximal margin elevation technique on marginal adaptation of ceramic inlays. Class II MOD-cavities were prepared in 40 human molars and randomly distributed to four groups (n = 10). In group EN (positive control) proximal margins were located in enamel, 1 mm above the cementoenamel junction, while 2 mm below in groups DE-1In, DE-2In and DE. The groups DE-1In, DE-2In and DE simulated subgingival location of the cervical margin. In group DE-1In one 3 mm and in group DE-2In two 1.5 mm composite layers (Tetric) were placed for margin elevation of the proximal cavities using Syntac classic as an adhesive. The proximal cavities of group DE remained untreated and served as a negative control. In all groups, ceramic inlays (Cerec 3D) were adhesively inserted. Replicas were taken before and after thermomechanical loading (1.200.000 cycles, 50/5°C, max. load 49 N). Marginal integrity (tooth-composite, composite-inlay) was evaluated with scanning electron microscopy (200×). Percentage of continuous margin (% of total proximal margin length) was compared between groups before and after cycling using ANOVA and Scheffé post-hoc test. After thermomechanical loading, no significant differences were observed between the different groups with respect to the interface composite-inlay and tooth-composite with margins in dentin. The interface tooth-composite in enamel of group EN was significantly better compared to group DE-2In, which was not different to the negative control group DE and DE-1In. Margin elevation technique by placement of a composite filling in the proximal box before insertion of a ceramic inlay results in marginal integrities not different from margins of ceramic inlays placed in dentin.

  14. Evaluation of marginal circumference and marginal thickness changes in precrimped stainless steel crowns, after recrimping

    Directory of Open Access Journals (Sweden)

    Afshar H

    2006-07-01

    Full Text Available Background and Aim: The need for recrimping precrimped stainless steel crowns by the dentist in clinic is controversial. This study aimed to evaluate the rate of marginal circumference and marginal thickness change of precrimped stainless steel crowns after recrimping. Materials and Methods: In this experimental study, 30 primary photos were taken from margins of 30 S.S.Cs (3M, Ni-Cr related to tooth 85 with a digital camera fixed at a determined distance. Margins of crowns were crimped by 114 and 137 pliers with a controlled force (0.2 N and then 30 secondary photos were taken in the same conditions. The circumference of crown margins in primary (group A and secondary (group B photos were assessed by a digitizer system. Comparing the circumferences of crown margins in primary and secondary photos showed a significant decrease after crimping. Thickness of 30 random points on the crown margins of a crown similar to mentioned cases was measured by SEM (×150. Then similar procedures including taking a primary photo, crimping and taking a secondary photo was done for the sample crown. After significant reduction in margin circumference, thickness of 30 other random points on the crown margin were measured by SEM. Data were analyzed by paired sample t-test with p<0.05 as the limit of significance. Results: The mean marginal circumference of precrimped stainless steel crowns was reduced by 7.3% which was significant (P<0.001. On the other hand the mean marginal thickness of sample stainless steel crown showed 18µ increase. Conclusion: According to the results of this study, marginal circumference of precrimped stainless steel crowns (3M, Ni-Cr showed a significant decrease after crimping. It is concluded that crimping the stainless steel crowns even for precrimped ones seems necessary.

  15. Pacific Northwest Salmon Habitat Project Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the Pacific Northwest Salmon Habitat Project Database Across the Pacific Northwest, both public and private agents are working to improve riverine habitat for a...

  16. Infant Mortality and Asians and Pacific Islanders

    Science.gov (United States)

    ... Population Profiles > Asian American > Infant Health & Mortality Infant Mortality and Asians and Pacific Islanders Among Asian/Pacific ... as compared to non-Hispanic white mothers. Infant Mortality Rate Infant mortality rate per 1,000 live ...

  17. 76 FR 38370 - Western Pacific Fisheries; Approval of a Marine Conservation Plan for Pacific Insular Areas...

    Science.gov (United States)

    2011-06-30

    ... is, in the EEZ around the Pacific remote island areas (PRIA). The PRIA are Baker Island, Howland... National Oceanic and Atmospheric Administration RIN 0648-XA517 Western Pacific Fisheries; Approval of a Marine Conservation Plan for Pacific Insular Areas; Western Pacific Sustainable Fisheries Fund AGENCY...

  18. Maternal Perspectives of Prenatal Sonogram in a North-Eastern ...

    African Journals Online (AJOL)

    Limited information exists on maternal perspectives of prenatal sonogram in north-eastern Nigeria. This study was aimed at documenting the views and expectations of pregnant women concerning prenatal sonogram as well as their level of awareness of its purpose, limitations and safety in a predominantly Moslem society.

  19. Economietric analysis of cowpea production in the north-eastern ...

    African Journals Online (AJOL)

    Economietric analysis of cowpea production in the north-eastern part of Adamawa State, Nigeria. J Stephen, SI Mshelia. Abstract. No Abstract. Global Journal of Agricultural Sciences Vol. 7 (1) 2008: pp.127-130. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  20. Flora of Chihuahuan desertscrub on limestone in northeastern Sonora, Mexico

    Science.gov (United States)

    Thomas R. Van Devender; Ana Lilia Reina-Guerrero; J. Jesus. Sanchez-Escalante

    2013-01-01

    Transects were done in desertscrub on limestone to characterize the flora of the westernmost Chihuahuan Desert. Most of the sites (15) were in the Municipios of Agua Prieta and Naco in northeastern Sonora, with single sites near Ascensión, northwestern Chihuahua and east of Douglas in southeastern Arizona. A total of 236 taxa were recorded on transects. Dicot perennial...

  1. Proceedings of the 1997 Northeastern Recreation Research Symposium

    Science.gov (United States)

    Hans G. Vogelsong; [Editor

    1998-01-01

    Contains articles presented at the 1997 Northeastern Recreation Research Symposium. Contents cover recreation; protected areas and social science; water based recreation management studies; forest recreation management studies; outdoor recreation management studies; estimation of economic impact of recreation and tourism; place meaning and attachment; tourism studies;...

  2. Optimal tree-stem bucking of northeastern species of China

    Science.gov (United States)

    Jingxin Wang; Chris B. LeDoux; Joseph McNeel

    2004-01-01

    An application of optimal tree-stem bucking to the northeastern tree species of China is reported. The bucking procedures used in this region are summarized, which are the basic guidelines for the optimal bucking design. The directed graph approach was adopted to generate the bucking patterns by using the network analysis labeling algorithm. A computer-based bucking...

  3. Are Northeastern U.S. forests vulnerable to extreme drought?

    Science.gov (United States)

    Adam P. Coble; Matthew A. Vadeboncoeur; Z. Carter Berry; Katie A. Jennings; Cameron D. McIntire; John L. Campbell; Lindsey E. Rustad; Pamela H. Templer; Heidi Asbjornsen

    2017-01-01

    In the Northeastern U.S., drought is expected to increase in frequency over the next century, and therefore, the responses of trees to drought are important to understand. There is recent debate about whether land-use change or moisture availability is the primary driver of changes in forest species composition in this region. Some argue that fire suppression from the...

  4. Genetic characteristics of red foxes In northeastern Oregon

    Science.gov (United States)

    Gregory A Green; Benjamin N Sacks; Leonard J Erickson; Keith B Aubry

    2017-01-01

    The Rocky Mountain Red Fox (Vulpes vulpes macroura), once common in the Blue Mountains ecoregion of northeastern Oregon, was considered rare in eastern Oregon by the 1930s and thought to be extirpated by the 1960s, when putatively new Red Fox populations began to appear. Although the new foxes were long presumed to be nonnative (originating from...

  5. Earthworm communities along an elevation gradient in Northeastern Puerto Rico.

    Science.gov (United States)

    Grizelle Gonzalez; Emerita Garcia; Veronica Cruz; Sonia Borges; Marcela Zalamea; Maria M. Rivera

    2007-01-01

    In this study, we describe earthworm communities along an elevation gradient of eight forest types in Northeastern Puerto Rico, and determine whether their abundance, biomass and/or diversity is related to climatic, soil physical/chemical and/or biotic characteristics. We found that the density, biomass, and diversity of worms varied significantly among forest types....

  6. Depression amongst healthcare workers in Maiduguri, north-eastern ...

    African Journals Online (AJOL)

    Objective: Very few studies reported the high prevalence of emotional reactions amongst healthcare workers, in sub-Saharan Africa. This study aimed to assess the prevalence of depression among health care workers in two tertiary health institutions in Maiduguri, north-Eastern Nigeria. Methods: In this comparative, ...

  7. Occurrence and geochemistry of Nafada Gypsum, north-eastern ...

    African Journals Online (AJOL)

    Gypsum deposits occur in numerous locations within the Senonian Fika Shale at Nafada, northeastern Nigeria. Geologic investigations at Baro Winde and Wuro Dabo mines indicate the occurrence of three varieties of gypsum namely, Balatino laminated, Alabaster and Satin Spar. These are interlayered within shale and ...

  8. Forest ingrowth prediction model for the Northeastern United States

    Science.gov (United States)

    Linda S. Gribko

    1997-01-01

    In the last 20 years, there has been a revival of interest in the use of uneven-aged forest management techniques in the production of timber and forest amenity values. Uneven-aged management is coming into renewed favor especially among non-industrial private landowners in the northeastern United States. The practice allows periodic timber removals on relatively small...

  9. Wildfire atlas of the northeastern and north central states.

    Science.gov (United States)

    Donald A. Haines; Von J. Johnson; William A. Main

    1975-01-01

    Describes patterns of forest fire activity across the northeastern and north central United States. Gives average dates of greening ad curing of herbaceous plants, medium size of fires in various fuels, and annual profiles of peak fire activity. It also examines combinations of major fire cause and day-of-week activity.

  10. Achieving wood energy potentials: evidence in northeastern Minnesota.

    Science.gov (United States)

    Dennis P. Bradley; David C. Lothner

    1987-01-01

    A study of wood energy potential in northeastern Minnesota concludes that (1) the forests of the region could support a much larger wood energy harvest without significant cost increases for other forest products; (2) existing stands are predominantly overmature and cutting more now will enhance future wood supplies for all users; (3) converting to wood energy could...

  11. Proceedings of the 2010 Northeastern Recreation Research Symposium

    Science.gov (United States)

    Cherie LeBlanc Fisher; Clifton E., Jr., eds. Watts

    2012-01-01

    Contains articles presented at the 2010 Northeastern Recreation Research Symposium. Contents cover tourism marketing, fish and wildlife, place meaning, leisure and demographics, nature-based tourism, methods, leisure motives, outdoor recreation management, outdoor recreation among specific populations, leisure constraints, environmental attitudes and values, leisure...

  12. Proceedings of the 2009 Northeastern Recreation Research Symposium

    Science.gov (United States)

    Clifton E. Watts; Cherie LeBlanc Fisher

    2010-01-01

    Contains articles and posters presented at the 2009 Northeastern Recreation Research Symposium. Contents cover GIS applications and recreation resource quality, meanings and measurement of recreation, climate change and resource planning, youth and outdoor recreation, urban recreation challenges, outdoor recreation--trails, human dimensions of wildlife, leisure and...

  13. Proceedings of the 2007 northeastern recreation research symposium

    Science.gov (United States)

    Cherie LeBlanc; Christine, comps. Vogt

    2008-01-01

    Contains articles and posters presented at the 2007 northeastern recreation research symposium. Contents cover tourism marketing, fish and wildlife, place meaning, leisure and gender, recreation resource allocation, nature-based tourism, methods, leisure motives, outdoor recreation management, tourism impacts, outdoor recreation among specific populations, leisure...

  14. Proceedings of the 2006 Northeastern Recreation Research Symposium

    Science.gov (United States)

    R. Burns; K., comps. Robinson

    2007-01-01

    Contains articles and posters presented at the 2006 Northeastern Recreation Research Symposium. Contents cover tourism marketing, fish and wildlife, place meaning, leisure and gender, recreation resource allocation, nature-based tourism, methods, leisure motives, outdoor recreation management, tourism impacts, outdoor recreation among specific populations, leisure...

  15. Prevalence of Overweight and Obesity in Maiduguri, North-Eastern ...

    African Journals Online (AJOL)

    BACKGROUND: The prevalence of obesity is on the increase worldwide including in many developing countries. There is no report on the magnitude of obesity among adults in Maiduguri, a major city in northeastern Nigeria. MATERIALS and METHODS: We selected a sample of 1650 men and women aged 15 years and ...

  16. Michanthidium almeidai, a new species from northeastern Brazil (Hymenoptera, Megachilinae)

    Science.gov (United States)

    Urban, Danúncia; Parizotto, Daniele Regina

    2011-01-01

    Abstract A new species of Michanthidium Urban (Hymenoptera, Megachilinae)is described and figured from Sergipe and Bahia States, northeastern Brazil. An identification key, illustrations, and a distribution map for the three species of the genus are presented. The male genitalia of Michanthidium almeidai sp. n. and Michanthidium albitarse are illustrated and compared for the first time. PMID:22140334

  17. Lodgepole pine in the Blue Mountains of northeastern Oregon.

    Science.gov (United States)

    James M. Trappe; Robert W. Harris

    1958-01-01

    Lodgepole pine (Pinus contorta) is a major species in northeastern Oregon. The lodgepole type covers nearly 400,000 acres in the Blue and Wallowa Mountains, and individual trees are scattered over many of the remaining six million forested acres in this area (2). The type blankets large areas in watersheds in a region where spring floods and summer...

  18. Proceedings of the 2001 Northeastern Recreation Research Symposium

    Science.gov (United States)

    Sharon. Comp, ed. Todd

    2002-01-01

    Contains 71 articles presented at the 2001 Northeastern Recreation Research Symposium which seeks to foster quality information exchange between recreation, tourism, and resource managers and researchers throughout the Northeast. The forum provides opportunities for recreation and tourism research managers from different agencies, state, and government levels, as well...

  19. Proceedings of the 2003 Northeastern Recreation Research Symposium

    Science.gov (United States)

    James, comp., ed. Murdy; ed. comp.

    2004-01-01

    Contains articles presented at the 2003 Northeastern Recreation Research Symposium. Contents cover planning issues, communications and information, management presentations, service quality and outdoor recreation, recreation behavior, founders? forum, featured posters, tourism and the community, specialized recreation, recreation and the community, management issues in...

  20. Lipid profile pattern in thyroid disorders in northeastern Nigeria ...

    African Journals Online (AJOL)

    Objectives: To determine lipid pattern in thyroid disorders in northeastern Nigeria. Methods: 18 simple goiter, 41 thyrotoxicosis patients, and 41 control subjects were recruited at the surgery clinic and department of Chemical Pathology of University of Maiduguri Teaching Hospital. Thyroid function test and lipid profile were ...

  1. A century of lessons about water resources in northeastern forests

    Science.gov (United States)

    James W. Hornbeck; James N. Kochenderfer; James N. Kochenderfer

    2001-01-01

    Water resources in forests of the northeastern United States have been a contentious issue throughout the 20th century. The Weeks Law of 1911 recognized the needs to protect water yield and quality, and stimulated long-term interest in the relationships between forests and water. Research has provided a clear understanding of the roles of forests in hydrologic and...

  2. Proceedings of the 2008 Northeastern Recreation Research Symposium

    Science.gov (United States)

    David B. Klenosky; Cherie LeBlanc Fisher; eds.

    2009-01-01

    Contains articles and posters presented at the 2008 Northeastern Recreation Research Symposium. Contents cover tourism marketing, fish and wildlife, place meaning, leisure and gender, recreation resource allocation, nature-based tourism, methods, leisure motives, outdoor recreation management, tourism impacts, outdoor recreation among specific populations, leisure...

  3. Conservation Priorities for Terrestrial Birds in the Northeastern United States

    Science.gov (United States)

    Kenneth V. Rosenberg; Jeffrey V. Wells

    2005-01-01

    As part of the Partners in Flight (PIF) bird-conservation planning process, we assessed breeding land bird species according to seven categories of population vulnerability to derive a priority species pool in each of 12 physiographic areas that overlap the northeastern U.S. We then grouped species into the following habitat-species suites: (1) boreal-mountaintop...

  4. Reconstructing Rodinia by Fitting Neoproterozoic Continental Margins

    Science.gov (United States)

    Stewart, John H.

    2009-01-01

    Reconstructions of Phanerozoic tectonic plates can be closely constrained by lithologic correlations across conjugate margins by paleontologic information, by correlation of orogenic belts, by paleomagnetic location of continents, and by ocean floor magmatic stripes. In contrast, Proterozoic reconstructions are hindered by the lack of some of these tools or the lack of their precision. To overcome some of these difficulties, this report focuses on a different method of reconstruction, namely the use of the shape of continents to assemble the supercontinent of Rodinia, much like a jigsaw puzzle. Compared to the vast amount of information available for Phanerozoic systems, such a limited approach for Proterozoic rocks, may seem suspect. However, using the assembly of the southern continents (South America, Africa, India, Arabia, Antarctica, and Australia) as an example, a very tight fit of the continents is apparent and illustrates the power of the jigsaw puzzle method. This report focuses on Neoproterozoic rocks, which are shown on two new detailed geologic maps that constitute the backbone of the study. The report also describes the Neoproterozoic, but younger or older rocks are not discussed or not discussed in detail. The Neoproterozoic continents and continental margins are identified based on the distribution of continental-margin sedimentary and magmatic rocks that define the break-up margins of Rodinia. These Neoproterozoic continental exposures, as well as critical Neo- and Meso-Neoproterozoic tectonic features shown on the two new map compilations, are used to reconstruct the Mesoproterozoic supercontinent of Rodinia. This approach differs from the common approach of using fold belts to define structural features deemed important in the Rodinian reconstruction. Fold belts are difficult to date, and many are significantly younger than the time frame considered here (1,200 to 850 Ma). Identifying Neoproterozoic continental margins, which are primarily

  5. New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae

    Directory of Open Access Journals (Sweden)

    John Taylor

    2013-08-01

    Full Text Available Four new species and a new genus of lucinid bivalves are described from shallow and deeper waters in the Indian and West Pacific Oceans. The new genus Scabrilucina (subfamily Lucininae includes the little-known S. victorialis (Melvill, 1899 from the Arabian Sea and S. vitrea (Deshayes, 1844 from the Andaman Sea as well as a new species S. melvilli from the Torres Strait off northeastern Australia. Ferrocina brunei new species (Lucininae was recovered from 60 m near oil drilling activities off Borneo; its anatomy confirmed the presence of symbiotic bacteria. Two unusual deeper water species of Leucosphaerinae are described, both species included in on-going molecular analyses; Gonimyrtea ferruginea from 400–650 m in the southwest Pacific and Myrtina reflexa from 200–825 m off Zanzibar and Madagascar.

  6. South Pacific Nuclear Free Zone Treaty

    International Nuclear Information System (INIS)

    1986-02-01

    The full text of the South Pacific Nuclear Free Zone Treaty with its Annexes endorsed on 6 August 1985 by the South Pacific Forum (a body comprising the independent and self-governing countries of the South Pacific, namely Australia, the Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Nive, Papua New Guinea, the Solomon Islands, Tonga, Tuvalu, Vanuatu and Western Samoa) is presented

  7. South Pacific Nuclear Free Zone Treaty

    International Nuclear Information System (INIS)

    1986-02-01

    On 6 August 1985 the South Pacific Forum, a body comprising the independent and self-governing countries of the South Pacific (Australia, the Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Niue, Papua New Guinea, the Solomon Islands, Tonga, Tuvalu, Vanuatu and Western Samoa), endorsed the text of the South Pacific Nuclear Free Zone Treaty and opened it for signature [es

  8. South Pacific Nuclear Free Zone Treaty

    International Nuclear Information System (INIS)

    1986-02-01

    On 6 August 1985 the South Pacific Forum, a body comprising the independent and self-governing countries of the South Pacific (Australia, the Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Niue, Papua New Guinea, the Solomon Islands, Tonga, Tuvalu, Vanuatu and Western Samoa), endorsed the text of the South Pacific Nuclear Free Zone Treaty and opened it for signature [ru

  9. Ferritin associates with marginal band microtubules

    International Nuclear Information System (INIS)

    Infante, Anthony A.; Infante, Dzintra; Chan, M.-C.; How, P.-C.; Kutschera, Waltraud; Linhartova, Irena; Muellner, Ernst W.; Wiche, Gerhard; Propst, Friedrich

    2007-01-01

    We characterized chicken erythrocyte and human platelet ferritin by biochemical studies and immunofluorescence. Erythrocyte ferritin was found to be a homopolymer of H-ferritin subunits, resistant to proteinase K digestion, heat stable, and contained iron. In mature chicken erythrocytes and human platelets, ferritin was localized at the marginal band, a ring-shaped peripheral microtubule bundle, and displayed properties of bona fide microtubule-associated proteins such as tau. Red blood cell ferritin association with the marginal band was confirmed by temperature-induced disassembly-reassembly of microtubules. During erythrocyte differentiation, ferritin co-localized with coalescing microtubules during marginal band formation. In addition, ferritin was found in the nuclei of mature erythrocytes, but was not detectable in those of bone marrow erythrocyte precursors. These results suggest that ferritin has a function in marginal band formation and possibly in protection of the marginal band from damaging effects of reactive oxygen species by sequestering iron in the mature erythrocyte. Moreover, our data suggest that ferritin and syncolin, a previously identified erythrocyte microtubule-associated protein, are identical. Nuclear ferritin might contribute to transcriptional silencing or, alternatively, constitute a ferritin reservoir

  10. Stratigraphy of Atlantic coastal margin of United States north of Cape Hatteras; brief survey

    Science.gov (United States)

    Perry, W.J.; Minard, J.P.; Weed, E.G.A.; Robbins, E.I.; Rhodehamel, E.C.

    1975-01-01

    A synthesis of studies of sea-floor outcrops of the sedimentary wedge beneath the northeastern United States continental shelf and slope and a reassessment of coastal plain Mesozoic stratigraphy, particularly of the coastal margin, provide insight for estimating the oil and gas potential and provide geologic control for marine seismic investigations of the Atlantic continental margin. The oldest strata known to crop out on the continental slope are late Campanian in age. The Cretaceous-Tertiary contact along the slope ranges from a water depth of 0.6 to 1.5 km south of Georges Bank to 1.8 km in Hudson Canyon. Few samples are available from Tertiary and Late Cretaceous outcrops along the slope. Sediments of the Potomac Group, chiefly of Early Cretaceous age, constitute a major deltaic sequence in the emerged coastal plain. This thick sequence lies under coastal Virginia, Maryland, Delaware, southeastern New Jersey, and the adjacent continental shelf. Marine sands associated with this deltaic sequence may be present seaward under the outer continental shelf. South of the Norfolk arch, under coastal North Carolina, carbonate rocks interfinger with Lower Cretaceous clastic strata. From all available data, Mesozoic correlations in coastal wells between coastal Virginia and Long Island have been revised. The Upper-Lower Cretaceous boundary is placed at the transition between Albian and Cenomanian floras. Potential hydrocarbon source beds are present along the coast in the subsurface sediments of Cretaceous age. Potential reservoir sandstones are abundant in this sequence.

  11. Study of crustal structure and geological implications of southwestern margin of Northeast India

    Science.gov (United States)

    Saikia, Sowrav; Baruah, Santanu; Chopra, Sumer; Singh, Upendra K.; Gogoi, Bibhuti; Gohain, Himanata B.

    2018-01-01

    It is noticed that few geophysical studies have been carried out to decipher the crustal structure of southwestern part of the Northeast India comprising of Tripura fold belt and Bengal basin as compared to the Shillong plateau and the Brahmaputra basin. This region has a long history of seismicity that is still continuing. We have determined first-order crustal features in terms of Moho depths ( H) and average VP/VS ratios ( κ) using H- κ stacking technique. The inversion of receiver functions data yields near surface thick sedimentary layer in the Bengal basin, which is nearly absent in the Shillong plateau and Tripura fold belt. Our result suggests that the crust is thicker (38-45 km) in the Tripura fold belt region with higher shear-wave velocity in the lower crust than the Shillong plateau. The distribution of VP/VS ratio indicates heterogeneity throughout the whole region. While low to medium value of Poisson's ratio (1.69-1.75) indicates the presence of felsic crust in the Shillong plateau of the extended Indian Archean crust. The medium to high values of VP/VS ratio (> 1.780) in the Bengal basin and the Tripura fold belt region represent mafic crust during the formation of the Bengal delta and the Tripura fold belt creation in the Precambrian to the Permian age. The depth of the sediments in the Bengal basin is up to 8 km on its eastern margin, which get shallower toward its northeastern and southeastern margins.

  12. Digital Margins : How spatially and socially marginalized communities deal with digital exclusion

    NARCIS (Netherlands)

    Salemink, Koen

    2016-01-01

    The increasing importance of the Internet as a means of communication has transformed economies and societies. For spatially and socially marginalized communities, this transformation has resulted in digital exclusion and further marginalization. This book presents a study of two kinds of

  13. Refining prices and margins in 1998

    International Nuclear Information System (INIS)

    Favennec, J.P.; Baudoin, C.

    1999-01-01

    Despite a business environment that was globally mediocre due primarily to the Asian crisis and to a mild winter in the northern hemisphere, the signs of improvement noted in the refining activity in 1996 were borne out in 1997. But the situation is not yet satisfactory in this sector: the low return on invested capital and the financing of environmental protection expenditure are giving cause for concern. In 1998, the drop in crude oil prices and the concomitant fall in petroleum product prices was ultimately rather favorable to margins. Two elements tended to put a damper on this relative optimism. First of all, margins continue to be extremely volatile and, secondly, the worsening of the economic and financial crisis observed during the summer made for a sharp decline in margins in all geographic regions, especially Asia

  14. Code breaking in the pacific

    CERN Document Server

    Donovan, Peter

    2014-01-01

    Covers the historical context and the evolution of the technically complex Allied Signals Intelligence (Sigint) activity against Japan from 1920 to 1945 Describes, explains and analyzes the code breaking techniques developed during the war in the Pacific Exposes the blunders (in code construction and use) made by the Japanese Navy that led to significant US Naval victories

  15. The Stylasterina of the Pacific

    NARCIS (Netherlands)

    Boschma, H.

    1953-01-01

    In 1857 and 1860, Milne Edwards and Haime listed 9 species of Stylasterlna known to occur in the Pacific region, including "Allopora (Stylaster) infundibulifera", a species which later, as Amphelia infundibulifera (Lamarck), was to be classified in the Madreporaria (Scleractinia). Moseley (1880),

  16. Sustainable fisheries management: Pacific salmon

    Science.gov (United States)

    Knudsen, E. Eric; Steward, Cleveland R.; MacDonald, Donald; Williams, Jack E.; Reiser, Dudley W.

    1999-01-01

    What has happened to the salmon resource in the Pacific Northwest? Who is responsible and what can be done to reverse the decline in salmon populations? The responsibly falls on everyone involved - fishermen, resource managers and concerned citizens alike - to take the steps necessary to ensure that salmon populations make a full recovery.This collection of papers examines the state of the salmon fisheries in the Pacific Northwest. They cover existing methods and supply model approaches for alternative solutions. The editors stress the importance of input from and cooperation with all parties involved to create a viable solution. Grass roots education and participation is the key to public support - and ultimately the success - of whatever management solutions are developed.A unique and valuable scientific publication, Sustainable Fisheries Management: Pacific Salmon clearly articulates the current state of the Pacific salmon resource, describes the key features of its management, and provides important guidance on how we can make the transition towards sustainable fisheries. The solutions presented in this book provide the basis of a strategy for sustainable fisheries, requiring society and governmental agencies to establish a shared vision, common policies, and a process for collaborative management.

  17. Trade in the Pacific Rim.

    Science.gov (United States)

    Dollar, David

    1988-01-01

    States that international trade is a prime factor linking the Pacific Rim nations. Discusses the differences in each nation's productive factors (land, labor, capital) and examines the emerging technological competition. Concludes that if U.S. firms cannot meet the challenge of foreign competition, then protectionism might limit further economic…

  18. Numerical modeling of the organic matter transformation in the sedimentary rocks of the northeastern Sakhalin shelf

    Science.gov (United States)

    Galushkin, Yu. I.; Sitar, K. A.; Kunitsyna, A. V.

    2011-06-01

    A basin modeling system was used to numerically reconstruct the burial, thermal, and catagenesis histories of the rocks in the sedimentary sections of four boreholes in the Kaigan-Vasyukan part of the Sakhalin-5 area on the northeastern shelf of Sakhalin. The sedimentary section of the basin includes the Late Cretaceous complex in addition to the Cenozoic one. The region of the shelf considered here is located within the Okhotsk block margin near to the East Sakhalin accretion complex in the region subjected to active fault tectonics. Consequently, two limiting versions of the basin's development are analyzed in this paper: the first with the local-isostatic response of the basin's lithosphere during the basin's entire history and the second with the isostatic behavior of the lithosphere beginning from the time of the Kuril Island Arc's formation (about 34 Ma BP). The modeling suggests a rather high thermal mode of the basin at intensive sedimentation during the last 10 Ma. The rocks of the upper half of the Late Cretaceous formation; the Eocene, Machigar, and Daekhurin formations; and the lower half of the Uinin complex could generate oil up to the present time. In contrast, the rocks of the upper half of the Uinin complex and the Dagi, Okobykai, and Lower and Upper Nutov formations are interesting only as the reservoir and cap rocks for the hydrocarbons generated in the lower levels.

  19. Research on Recent GPS Crustal Deformation Characteristics in the Northeastern Edge of Qinghai-Tibet Plateau

    Science.gov (United States)

    Ma, Haiping; Wu, Yanqiang; Feng, Jian’gang; Xu, Rong; Wu, Shayi; Wang, Qian

    2017-10-01

    Based on the GPS data in the northeastern edge of Qinghai-Tibet Plateau, the velocity field and the extension change rate of baseline between stations are analyzed. The crustal movement characteristics and their dynamic changes in this region are discussed. The result indicates that the baseline in the regions demonstrates an overall characteristic of shrinking in the NE direction and extending in the NW direction; The extrusion of Bayan Har Block in SE direction since 2009 has amplified obviously, which leads to the enhancement of correlated movement in SE direction in the NW side of Longmenshan Fault. In addition, Tianzhu empty regions and the area near the epicenter of Menyuan Ms6.4 earthquake in 2016 are right in the boundary of this differentiated movement. Recently, a certain amount of strain energy might have been accumulated in the nearby area of the northern margin of Alkin Fault Zone, west boundary of Erdos Block and west to105°N on Northern Xiqinling Fault. The seismic risk in the west and east section of the intersecting area between Bayan Har Block and Qaidam Block is high. The west section of Northern Xiqinling Fault belongs to the inner ring of clockwise vortex and possesses medium-strong seismic risk.

  20. Present-day crustal deformation and strain transfer in northeastern Tibetan Plateau

    Science.gov (United States)

    Li, Yuhang; Liu, Mian; Wang, Qingliang; Cui, Duxin

    2018-04-01

    The three-dimensional present-day crustal deformation and strain partitioning in northeastern Tibetan Plateau are analyzed using available GPS and precise leveling data. We used the multi-scale wavelet method to analyze strain rates, and the elastic block model to estimate slip rates on the major faults and internal strain within each block. Our results show that shear strain is strongly localized along major strike-slip faults, as expected in the tectonic extrusion model. However, extrusion ends and transfers to crustal contraction near the eastern margin of the Tibetan Plateau. The strain transfer is abrupt along the Haiyuan Fault and diffusive along the East Kunlun Fault. Crustal contraction is spatially correlated with active uplifting. The present-day strain is concentrated along major fault zones; however, within many terranes bounded by these faults, intra-block strain is detectable. Terranes having high intra-block strain rates also show strong seismicity. On average the Ordos and Sichuan blocks show no intra-block strain, but localized strain on the southwestern corner of the Ordos block indicates tectonic encroachment.

  1. Roveacrinids in mid-Cretaceous biostratigraphy of the Sergipe Basin, northeastern Brazil

    Science.gov (United States)

    Ferré, Bruno; Walter, Simone; Bengtson, Peter

    2005-08-01

    As part of a study of the Cenomanian-Coniacian sedimentary succession in the Sergipe Basin in northeastern Brazil, microfacies analyses were tested for possible chronostratigraphic application. The common and widespread remains of roveacrinid echinoderms proved useful for intrabasinal biochronostratigraphy. Local dolomitization in the basin, which destroyed most other fossil remains, left the magnesian-calcitic roveacrinid skeletons largely unaffected. Thus, where diagnostic fossils are scarce or lacking, roveacrinids may provide an ancillary means of chronostratigraphic correlation. The forms recorded from Sergipe are described, and a stratigraphic range chart is presented for intrabasinal application, with the possibility of regional or even global correlation either qualitatively (presence/absence patterns) or quantitatively (eco-event patterns). Several roveacrinid abundance horizons have been reported worldwide in relation to sea level changes and associated hypoxic events, during which roveacrinids developed abundant opportunistic populations. The present study of the Sergipe Basin provides a basis for comparisons and correlations of roveacrinid occurrences in the mid-Cretaceous succession of the South Atlantic continental margin basins and ODP/DSDP drill cores.

  2. Paleozoic strata of the Dyckman Mountain area, northeastern Medfra quadrangle, Alaska

    Science.gov (United States)

    Dumoulin, Julie A.; Bradley, Dwight C.; Harris, Anita G.

    2000-01-01

    Paleozoic rocks in the Dyckman Mountain area (northeastern Medfra quadrangle; Farewell terrane) include both shallowand deep-water lithologies deposited on and adjacent to a carbonate platform. Shallow-water strata, which were recognized by earlier workers but not previously studied in detail, consist of algal-laminated micrite and skeletal-peloidal wackestone, packstone, and lesser grainstone. These rocks are, at least in part, of Early and (or) Middle Devonian age but locally could be as old as Silurian; they accumulated in shallow subtidal to intertidal settings with periodically restricted water circulation. Deepwater facies, reported here for the first time, are thin, locally graded beds of micrite and calcisiltite and subordinate thick to massive beds of lime grainstone and conglomerate. Conodonts indicate an age of Silurian to Middle Devonian; the most tightly dated intervals are early Late Silurian (early to middle Ludlow). These strata formed as hemipelagic deposits, turbidites, and debris flows derived from shallow-water lithologies of the Nixon Fork subterrane. Rocks in the Dyckman Mountain area are part of a broader facies belt that is transitional between the Nixon Fork carbonate platform to the west and deeper water, basinal lithologies (Minchumina “terrane”) to the east. Transitional facies patterns are complex because of Paleozoic shifts in the position of the platform margin, Mesozoic shortening, and Late Cretaceous-Tertiary disruption by strike-slip faulting.

  3. The Effect of Afforestation on Soil Moisture Content in Northeastern China.

    Directory of Open Access Journals (Sweden)

    Yitong Yao

    Full Text Available Widespread afforestation programs sequester carbon from the atmosphere and mitigate the rising of atmospheric carbon dioxide (CO2. Meanwhile, afforestation carbon sequestration may cost soil water. However, changes in soil moisture content (SMC after large-scale afforestation or reforestation have rarely been quantified. In this study, we measured changes in SMC following afforestation using a paired plots method with data from 757 plots in Northeastern China. We found a marginally significant decline in soil moisture content of the top 1-m soil (SMC0-1m after afforestation (P = 0.08 at the regional scale. The SMC responses to afforestation also vary across species. For example, significant SMC decrease are found for Populus spp. plantations (P < 0.05 and plantations of Pinus sylvestris var. mongolica (P < 0.05. Splitting the first meter of the soil profile into different depth intervals revealed that SMC declined significantly in shallow layers (0-30 cm for Populus spp. and Pinus sylvestris var. mongolica. We also found that when SMC in the control exceeded a specific threshold, SMC for all five tree species considered tended to decrease, suggesting that the effects of afforestation on soil hydrology vary across different regions.

  4. A new species of Cymadusa Savigny, 1816 (Crustacea: Amphipoda: Ampithoidae from northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Luiz F. Andrade

    Full Text Available A new species of the amphipod family Ampithoidae Stebbing, 1899 is described from the northeastern Brazilian waters. The new described taxon is grouped in the genus Cymadusa Savigny, 1816, since it presents all the diagnostic characteristics of the genus. The examined material was collected by scuba diving in the Rocas Atoll, off Rio Grande do Norte state coast, Camamu Bay and Todos os Santos Bay, Bahia state. The new species described here is close to C. filosa Savigny, 1816, type species of the genus, by presenting anterior margin of gnathopod 1 poorly setose, male gnathopod 2 densely setose, with palmar corner not defined by a spine and dactylus subequal in length to palm, being considered part of the C. filosa complex. Among the species of this complex, the one which most resembles to the new taxon is C. imbroglio Rabindranath, 1972, which is distinguished by the absence of both the trapezoid process in the palm and spine at the palmar corner in the gnathopod 2. This is the second species of the genus Cymadusa recorded from Brazilian waters.

  5. Osteology of some catfishes of the genus Glyptothorax (Teleostei: Siluriformes of northeastern India

    Directory of Open Access Journals (Sweden)

    W. Vishwanath

    2010-10-01

    Full Text Available The morphology of the premaxilla, dentary, Weberian lamina, infraorbital series, vomer and frontal bones were observed in eight species of Glyptothorax of northeastern India. In G. botius, G. granulus, G. manipurensis, G. ngapang, G. striatus and G. ventrolineatus, the premaxilla consists only of proximal and distal tooth plates, the anterior portion of the dentary is slender and its dorsal surface bears villiform teeth, the lateral extension of posterior portion of Weberian lamina terminates at the level of the lateral margin of its anterior portion, and the frontal has a shallow orbital notch. In G. cavia and G. chindwinica, the premaxilla consists of proximal, distal and posterior elements on the roof of the oral cavity; the anterior portion of the dentary bears posterior extension of dentary tooth-plate; the lateral extension of the posterior portion of Weberian lamina extends almost to the distal tip of the fifth parapophysis; there are nine or ten infraorbital bones with a longer and broader body of the lacrimal; greatly enlarged vomerine head; and frontal bears a deep orbital notch. The jaw structure of G. burmanicus is discussed.

  6. Gill parasites of fish from two estuaries in northeastern Brazil: new hosts and geographical records

    Directory of Open Access Journals (Sweden)

    JÉSSICA E.S.A. GOLZIO

    Full Text Available ABSTRACT Parasites are important components of communities and constitute great part of the biological diversity found in ecosystems, providing valuable information about their hosts and the environment in which they live. However, despite its importance, parasitic diversity is still not well known in some regions of Brazil, especially with respect to fish parasites in the Northeast Region. The present study aims to perform the survey of gill parasites of fish from two tropical estuaries located in northeastern Brazil: Paraíba and Mamanguape rivers. Two collections were made in each estuary, one during the dry period (November / 2013 and the other during the rainy season (July / 2014. The fish were caught using a beach seine net, dragged along the main channel margin. After the identification, biometry and necropsy of the fish, their parasites were collected, stored and identified. For each species of parasite, the values of prevalence, mean intensity and mean abundance were calculated. Of the 882 examined fish, belonging to four species, 145 were parasitized by at least one species of parasite. In total, 18 taxa of parasites of the groups Monogenea, Digenea, Nematoda, Copepoda and Isopoda were recorded, being the copepod Acusicola brasiliensis the most abundant species of parasite.

  7. On probabilistically defined margins in radiation therapy

    International Nuclear Information System (INIS)

    Papiez, Lech; Langer, Mark

    2006-01-01

    Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem

  8. Random Marginal and Random Removal values

    OpenAIRE

    Calvo, Emilio

    2006-01-01

    We propose two variations of the non-cooperative bargaining model for games in coalitional form, introduced by Hart and Mas-Colell (1996a). These strategic games implement, in the limit, two new NTU-values: The random marginal and the random removal values. The main characteristic of these proposals is that they always select a unique payoff allocation in NTU-games. The random marginal value coincides with the Consistent NTU-value (Maschler and Owen, 1989) for hyperplane games, and with the S...

  9. On probabilistically defined margins in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Papiez, Lech; Langer, Mark [Department of Radiation Oncology, Indiana University, Indianapolis, IN (United States)

    2006-08-21

    Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem

  10. Geodynamic setting of Late Cretaceous Sn–W mineralization in southeastern Yunnan and northeastern Vietnam

    Directory of Open Access Journals (Sweden)

    Yanbo Cheng

    2016-12-01

    Full Text Available The Sn–W mineralization in SE Yunnan Province, China and NE Vietnam shares many similarities. Through comparing the geological and geochronological data, we suggest the Sn–W deposits and the associate igneous rocks in the region represent one regional magmatic-mineralization event. To explore the geodynamic setting of these mineralization and magmatic activities, a geochronological dataset in the regions has been presented, containing data of this study and previously published. The dataset shows that the Late Cretaceous magmatic–mineralization–metamorphic activities widely distribute along the eastern Asian continental margin. Existing studies support that this is the product of the subduction of the Palaeo-Pacific Plate beneath the Eurasian continent, which probably formed under an Andean-type active continental margin setting. According to the exhibited data, we preliminarily conclude that the late Cretaceous magmatic and Sn–W mineralization activities in the southeast Yunnan and northeast Vietnam region is one part of this subduction activities and should have formed under the same geodynamic setting.

  11. A Cooperative Industry - Government Woodland Caribou Research Program in Northeastern Alberta

    Directory of Open Access Journals (Sweden)

    Blair Rippin

    1996-01-01

    Full Text Available Rapid development of large scale logging and increasingly intensive petroleum exploration and development in northeastern Alberta prompted the establishment of a cooperative research program to investigate various aspects of woodland caribou (Rangifer tarandus caribou biology. The ultimate goal of the program is to develop an effective plan that will ensure the long term survival of caribou while allowing for renewable and non-renewable resource development. There are three parts to the program. Part I began early in 1991 and makes use of conventional radio telemetry as a means of recording various parameters of general caribou biology. The study area encompasses approximately 4000 km2 of low relief, boreal mixedwood forest. Preliminary results from 2500 radio locations (involving 50 individuals indicate that woodland caribou inhabiting the study area are non-migratory and are strongly associated with some of the more scarce peatland forest types present in the area. Investigations to document the basic biology and ecology will continue for another two years. Part II began in early 1993 as a part of a two-year investigation into the disturbance effects of petroleum exploration and development on caribou movements and behaviour. One objective of this study is to develop a predictive model useful in determining the cumulative effects of varying intensities of disturbance on caribou. Part III began in early 1994 with a proposed three-year investigation to determine the mechanism of spatial and temporal separation of caribou and moose in the study area. These relationships may indicate the means by which caribou minimize the impact of wolf predation on their populations in northeastern Alberta. Results will be applied to industrial land use and specifically to large scale forest harvesting planned for the area. The research program is supported through cooperative funding contributed by 24 petroleum companies, 1 forest company, 2 peat companies and

  12. 17 CFR 41.47 - Withdrawal of margin.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Withdrawal of margin. 41.47... PRODUCTS Customer Accounts and Margin Requirements § 41.47 Withdrawal of margin. (a) By the customer... deposited as margin for positions in an account may be withdrawn, provided that the equity in the account...

  13. 17 CFR 242.405 - Withdrawal of margin.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Withdrawal of margin. 242.405...) REGULATIONS M, SHO, ATS, AC, AND NMS AND CUSTOMER MARGIN REQUIREMENTS FOR SECURITY FUTURES Customer Margin Requirements for Security Futures § 242.405 Withdrawal of margin. (a) By the customer. Except as otherwise...

  14. Indian Ocean warming modulates Pacific climate change.

    Science.gov (United States)

    Luo, Jing-Jia; Sasaki, Wataru; Masumoto, Yukio

    2012-11-13

    It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain. Here we explore how the enhanced tropical Indian Ocean warming in recent decades favors stronger trade winds in the western Pacific via the atmosphere and hence is likely to have contributed to the La Niña-like state (with enhanced east-west Walker circulation) through the Pacific ocean-atmosphere interactions. Further analysis, based on 163 climate model simulations with centennial historical and projected external radiative forcing, suggests that the Indian Ocean warming relative to the Pacific's could play an important role in modulating the Pacific climate changes in the 20th and 21st centuries.

  15. New Exploration of North Kerguelen Plateau Margins : Constraints for the Australia-Antarctica Separation

    Science.gov (United States)

    Courrèges, E.; Vially, R.; Roest, W. R.; Patriat, M.; Patriat, P.; Loubrieu, B.; Lecomte, J.-C.; Schaming, M.; Schmitz, J.; Maia, M.

    2009-04-01

    at a key period (Oligocene), helps us understand the setting up of the oceanic plateau and the kinematics reconstructions between Antarctica and Australia plates. We focused on the northeastern margin of the Kerguelen Plateau, from 77E30 up to the Amsterdam Saint-Paul fracture zone, where the South East Indian Ridge (SEIR) shows a large offset toward the Kerguelen Plateau. On a larger scale, the opening between Kerguelen Plateau and Broken Ridge has kept very morphologically homologous margins on each side of the SEIR: in the Southern Kerguelen Plateau, the magnetic anomalies are regular, parallel to the SEIR and also to the morphological boundary of the plateau. In contrast, the northeastern margin of the Northern Kerguelen Plateau is not much explored and its interpretation less obvious, because volcanic masses overlie discordantly the oceanic crust. We compiled the magnetic anomalies pickings, integrating data from recent Kergueplac surveys and previous studies, to identify with more confidence the oldest anomalies at the plateau margin. We used it for reconstructions at different stages (from a8o to initial opening), realised with rotation poles of Cande & Stocks (2004). These reconstructions confirm that kinematic in the whole SE Indian Ocean, and in particular in the Northern part of the Kerguelen Plateau, remains unresolved. In particular, we discuss both the fit between Kerguelen and Broken Ridge and the implication for the opening between Australia and Antarctica as well as the possible junctions along the Amsterdam fracture zone with the Crozet basin where the spreading rate was much faster before A18.

  16. Early math intervention for marginalized students

    DEFF Research Database (Denmark)

    Overgaard, Steffen; Tonnesen, Pia Beck

    2016-01-01

    This study is one of more substudies in the project Early Math Intervention for Marginalized Students (TMTM2014). The paper presents the initial process of this substudy that will be carried out fall 2015. In the TMTM2014 project, 80 teachers, who completed a one week course in the idea of TMTM...

  17. Marginal adaptation of ceramic inserts after cementation

    NARCIS (Netherlands)

    Ozcan, M; Pfeiffer, P; Nergiz, [No Value

    2002-01-01

    The advantage of using ceramic inserts is to prevent major drawbacks of composite resins such as polymerization shrinkage, wear and microleakage. This in vitro study evaluated the marginal adaptation of two approximal ceramic insert systems after cementation to the cavities opened with ultrasonic

  18. Mundhulens mikroflora hos patienter med marginal parodontitis

    DEFF Research Database (Denmark)

    Larsen, Tove; Fiehn, Nils-Erik

    2011-01-01

    ikke dyrkes. Viden om samspillet mellem bakterierne i plakken, som er en biofilm, er ligeledes under hastig udvikling. Dette betyder, at vi i de kommende år løbende må revidere vores forståelse af marginal parodontitis’ mikrobiologi. I nærværende oversigtsartikel præsenteres den eksisterende viden...

  19. Mundhulens mikroflora hos patienter med marginal parodontitis

    DEFF Research Database (Denmark)

    Larsen, Tove; Fiehn, Nils-Erik

    2011-01-01

    Viden om marginal parodontitis’ mikrobiologi tog for alvor fart for ca. 40 år siden. Den tidlige viden var baseret på mikroskopiske og dyrkningsmæssige undersøgelser af den subgingivale plak. Anvendelsen af de nyere molekylærbiologiske metoder har betydet, at vor viden om de ætiologiske faktorer ...

  20. Marginal Strength of Collarless Metal Ceramic Crown

    Directory of Open Access Journals (Sweden)

    Sikka Swati

    2010-01-01

    fracture strength at margins of metal ceramic crowns cemented to metal tooth analogs. Crowns evaluated with different marginal configurations, shoulder and shoulder bevel with 0 mm, 0.5 mm, 1 mm, and 1.5 mm, were selected. Methods. Maxillary right canine typhodont tooth was prepared to receive a metal ceramic crown with shoulder margin. This was duplicated to get 20 metal teeth analogs. Then the same tooth was reprepared to get shoulder bevel configuration. These crowns were then cemented onmetal teeth analogs and tested for fracture strength atmargin on an Instron testing machine. A progressive compressive load was applied using 6.3 mm diameter rod with crosshead speed of 2.5 mm per minute. Statisticaly analysis was performed with ANOVA, Student's “t” test and “f” test. Results. The fracture strength of collarless metal ceramic crowns under study exceeded the normal biting force. Therefore it can be suggested that collarless metal ceramic crowns with shoulder or shoulder bevel margins up to 1.5 mm framework reduction may be indicated for anteriormetal ceramic restorations. Significance. k Collarless metal ceramic crowns have proved to be successful for anterior fixed restorations. Hence, it may be subjected to more clinical trials.

  1. The marginal costs of climate changing emissions

    NARCIS (Netherlands)

    Tol, R.S.J.; Downing, T.E.

    2004-01-01

    This paper presents the marginal costs of the emissions of a selected number of radiatively-active gases, three uniformly-mixed gases – carbon dioxide, methane, nitrous oxide – and two region-specific gases – nitrogen (from aircraft) and sulphur, which influence ozone and sulphate aerosol

  2. Environmental Degradation, Social Marginalization and the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Environmental Degradation, Social Marginalization and the Dynamics of Vulnerability in the Earthquake of October 2005 (Pakistan). On 8 October 2005, an earthquake registering 7.6 on the Richter scale struck northeast Pakistan. Although concentrated in a small area, the damage was severe. At least 73 000 people were ...

  3. Structure and tectonics of convergent plate margins

    Czech Academy of Sciences Publication Activity Database

    Špičák, Aleš (ed.); Čadek, O. (ed.); Engdahl, E. R. (ed.)

    2004-01-01

    Roč. 141, č. 4 (2004), s. 241 ISSN 0031-9201 R&D Projects: GA AV ČR KSK3012103 Keywords : tectonics * subduction * convergent margins Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.370, year: 2004

  4. Marketing margins and agricultural technology in Mozambique

    DEFF Research Database (Denmark)

    Arndt, Channing; Jensen, Henning Tarp; Robinson, Sherman

    2000-01-01

    of improved agricultural technology and lower marketing margins yield welfare gains across the economy. In addition, a combined scenario reveals significant synergy effects, as gains exceed the sum of gains from the individual scenarios. Relative welfare improvements are higher for poor rural households...

  5. Policy Implementation, Role Conflict and Marginalization

    African Journals Online (AJOL)

    Prince Acheampong

    The Stool Land Revenue (SLR) shared among Traditional Authorities (TAs) is only 7 per cent of the District Assemblies Common Fund (Grants). The District Assemblies receive 55 per cent of the. SLR plus DACF. The political structures, taxation authority, distribution of SLR, and Grants are used as tools to marginalize the ...

  6. Large margin image set representation and classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-07-06

    In this paper, we propose a novel image set representation and classification method by maximizing the margin of image sets. The margin of an image set is defined as the difference of the distance to its nearest image set from different classes and the distance to its nearest image set of the same class. By modeling the image sets by using both their image samples and their affine hull models, and maximizing the margins of the images sets, the image set representation parameter learning problem is formulated as an minimization problem, which is further optimized by an expectation - maximization (EM) strategy with accelerated proximal gradient (APG) optimization in an iterative algorithm. To classify a given test image set, we assign it to the class which could provide the largest margin. Experiments on two applications of video-sequence-based face recognition demonstrate that the proposed method significantly outperforms state-of-the-art image set classification methods in terms of both effectiveness and efficiency.

  7. Sustainable biomass production on Marginal Lands (SEEMLA)

    Science.gov (United States)

    Barbera, Federica; Baumgarten, Wibke; Pelikan, Vincent

    2017-04-01

    Sustainable biomass production on Marginal Lands (SEEMLA) The main objective of the H2020 funded EU project SEEMLA (acronym for Sustainable Exploitation of Biomass for Bioenergy from Marginal Lands in Europe) is the establishment of suitable innovative land-use strategies for a sustainable production of plant-based energy on marginal lands while improving general ecosystem services. The use of marginal lands (MagL) could contribute to the mitigation of the fast growing competition between traditional food production and production of renewable bio-resources on arable lands. SEEMLA focuses on the promotion of re-conversion of MagLs for the production of bioenergy through the direct involvement of farmers and forester, the strengthening of local small-scale supply chains, and the promotion of plantations of bioenergy plants on MagLs. Life cycle assessment is performed in order to analyse possible impacts on the environment. A soil quality rating tool is applied to define and classify MagL. Suitable perennial and woody bioenergy crops are selected to be grown in pilot areas in the partner countries Ukraine, Greece and Germany. SEEMLA is expected to contribute to an increasing demand of biomass for bioenergy production in order to meet the 2020 targets and beyond.

  8. 12 CFR 220.11 - Requirements for the list of marginable OTC stocks and the list of foreign margin stocks.

    Science.gov (United States)

    2010-01-01

    ... stocks and the list of foreign margin stocks. 220.11 Section 220.11 Banks and Banking FEDERAL RESERVE... (REGULATION T) § 220.11 Requirements for the list of marginable OTC stocks and the list of foreign margin... paragraph (f) of this section, OTC margin stock shall meet the following requirements: (1) Four or more...

  9. The Brazilian marginal basins: current state of knowledge; As bacias marginais brasileiras: estagio atual de conhecimento

    Energy Technology Data Exchange (ETDEWEB)

    Ponte, Francisco Celso; Asmus, Haroldo Erwin

    2004-11-01

    Based on distinctive stratigraphic and/or structural characteristics, the brazilian continental margin can be divided into two main provinces : (1)The southeastern-eastern province, extending from the Pelotas to the Recife - Joao Pessoa Basin, presents a tensional tectonic style of Late Jurassic - Early Cretaceous age, paralleling the structural alignments of the Precambrian basement, except in the northeastern segment where the Mesozoic faults of the Recife - Joao Pessoa Basin cut across the east west basement directions. The basin-fill, Upper Jurassic through Recent, consists, where complete, of three stratigraphic sequences, each of a distinct depositional environment: (a) a lower clastic non-marine sequence; (b) a middle evaporitic sequence, and (c) an upper clastic paralic and open marine sequence. (2)The northern province, extending from the Potiguar Basin to the Amazon Submarine Basin, displays both tensional and compressional tectonic styles of Upper Jurassic (?) to Upper Cretaceous age either paralleling or cutting transversally the basement alignments. The stratigraphic column differs from the southeastern - eastern province in lacking the Lower Cretaceous evaporitic rocks. The integration of the stratigraphic and structural data allows one to determine in the eastern Brazilian marginal basins the main evolutionary stages of a typical pull-apart continental margin: a continental pre-rift and rift stage, an evaporitic proto-ocean stage, and a normal open ocean stage. In the northern province it is possible to infer a continental rift valley stage, a marine transform - movement stage and an open ocean stage. The relationship between the rift valley and transform movement stages is not clear. (author)

  10. Decadal to centennial oscillations in the upper and lower boundaries of the San Diego, California margin Oxygen Minimum Zone

    Science.gov (United States)

    Myhre, S. E.; Hill, T. M.; Frieder, C.; Grupe, B.

    2016-02-01

    Here we present two new marine sediment archives from the continental margin of San Diego, California, USA, which record decadal to centennial oscillations in the hydrographic structure of the Eastern Pacific Oxygen Minimum Zone (OMZ). The two cores, located at 528 and 1,180 m water depth, record oceanographic history across overlapping timescales. Biotic communities, including Foraminifera, Echinodermata, Brachiopoda, Mollusca and Ostrocoda, were examined in subsurface (>10 cm sediment core depth) samples. Chronologies for both cores were developed with reservoir-corrected 14C dates of mixed planktonic Foraminifera and linearly interpolated sedimentation rates. Sediment ages for the cores range from 400-1,800 years before present. Indices of foraminiferal community density, diversity and evenness are applied as biotic proxies to track the intensification of the continental margin OMZ. Biotic communities at the shallower site reveal multi-decadal to centennial timescales of OMZ intensification, whereas the deeper site exhibits decadal to multi-decadal scales of hydrographic variability. Hypoxia-associated foraminiferal genera Uvigerina and Bolivina were compositionally dominant during intervals of peak foraminiferal density. Invertebrate assemblages often co-occurred across taxa groups, and thereby provide a broad trophic context for interpreting changes in the margin seafloor. Variability in the advection of Pacific Equatorial Water may mechanistically contribute to this described hydrographic variability. This investigation reconstructs historical timescales of OMZ intensification, seafloor ecological variability, and synchrony between open-ocean processes and regional climate.

  11. The Structure of Genetic Diversity in Eelgrass (Zostera marina L.) along the North Pacific and Bering Sea Coasts of Alaska

    Science.gov (United States)

    Talbot, Sandra L.; Sage, Kevin; Rearick, Jolene; Fowler, Megan C.; Muñiz-Salazar, Raquel; Baibak, Bethany; Wyllie-Echeverria, Sandy; Cabello-Pasini, Alehandro; Ward, David H.

    2016-01-01

    Eelgrass (Zostera marina) populations occupying coastal waters of Alaska are separated by a peninsula and island archipelago into two Large Marine Ecosystems (LMEs). From populations in both LMEs, we characterize genetic diversity, population structure, and polarity in gene flow using nuclear microsatellite fragment and chloroplast and nuclear sequence data. An inverse relationship between genetic diversity and latitude was observed (heterozygosity: R2 = 0.738, P < 0.001; allelic richness: R2 = 0.327, P = 0.047), as was significant genetic partitioning across most sampling sites (θ = 0.302, P < 0.0001). Variance in allele frequency was significantly partitioned by region only in cases when a population geographically in the Gulf of Alaska LME (Kinzarof Lagoon) was instead included with populations in the Eastern Bering Sea LME (θp = 0.128–0.172; P < 0.003), suggesting gene flow between the two LMEs in this region. Gene flow among locales was rarely symmetrical, with notable exceptions generally following net coastal ocean current direction. Genetic data failed to support recent proposals that multiple Zostera species (i.e. Z. japonica and Z. angustifolia) are codistributed with Z. marina in Alaska. Comparative analyses also failed to support the hypothesis that eelgrass populations in the North Atlantic derived from eelgrass retained in northeastern Pacific Last Glacial Maximum refugia. These data suggest northeastern Pacific populations are derived from populations expanding northward from temperate populations following climate amelioration at the terminus of the last Pleistocene glaciation.

  12. Structure and tectonic evolution of the northeastern Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.; Krishna, K.S.; Ramprasad, T.; Desa, M.; Subrahmanyam, V.; Sarma, K.V.L.N.S.

    of Bengal, and (5) deciphering the evolutionary history of the Bay of Bengal. In adequate of magnetic data and age information of the basement rocks of eastern continental margin of India and the Enderby basin of East Antarctica (which are conjugate margins...

  13. Resistance to permethrin in Culex tarsalis in northeastern Colorado.

    Science.gov (United States)

    Strong, Adam C; Kondratieff, Boris C; Doyle, Michael S; Black, William C

    2008-06-01

    Resistance to permethrin and the activity of metabolic enzymes were monitored in field-collected Culex tarsalis from northeastern Colorado during 2005 and 2006 and compared with a lab strain from Bakersfield, CA. Collections were made from 13 different sites within and outside of the mosquito abatement area. Resistance levels by year and early vs. late season were examined and median lethal time values and 95% confidence intervals were compared with the lab strain. Mosquitoes collected in 2005 were more resistant to permethrin than either the lab strain or mosquitoes collected in 2006. Glutathione S-transferase levels recorded in 2005 were 9-12x higher than either the lab strain or 2006 mosquitoes; activity of mixed-function oxidases was also greater. Both mechanisms may play a role in permethrin resistance or reflect nontarget exposure to other pesticides in Cx. tarsalis in northeastern Colorado.

  14. Opisthorchiasis in Northeastern Thailand: Effect of local environment and culture

    Directory of Open Access Journals (Sweden)

    Beuy Joob

    2015-06-01

    Full Text Available Opisthorchiasis is a kind of trematode infection. This parasitic infestation is a chronic hepatobiliary tract infection and can cause chronic irritation that will finally lead to cholangiocarcinoma. It is highly endemic in northeastern region of Thailand and contributes to many cholangiocarcinoma cases annually. The attempt to control the disease becomes a national policy. However, the sanitation becomes a major underlying factor leading to infection and meanwhile, the poverty and low education of the local people become an important concern. In this opinion, the authors discuss the effect of local environment and culture on opisthorchiasis in northeastern Thailand. Due to the pattern change of local environment, global warming and globalization, the dynamicity can be observed.

  15. Opisthorchiasis in Northeastern Thailand: Effect of local environment and culture

    OpenAIRE

    Beuy Joob; Viroj Wiwanitkit

    2015-01-01

    Opisthorchiasis is a kind of trematode infection. This parasitic infestation is a chronic hepatobiliary tract infection and can cause chronic irritation that will finally lead to cholangiocarcinoma. It is highly endemic in northeastern region of Thailand and contributes to many cholangiocarcinoma cases annually. The attempt to control the disease becomes a national policy. However, the sanitation becomes a major underlying factor leading to infection and meanwhile, the poverty ...

  16. Northeastern conifer research: Multiple species and multiple values

    Science.gov (United States)

    Laura S. Kenefic; John C. Brissette; Richard W. Judd

    2014-01-01

    The northern conifer, or spruce-fir, forest of the northeastern USA and adjacent Canada has had a defining influence on the economy and culture of the region. The same can be said of the USDA Forest Service’s research in this forest, which began more than 100 years ago. Forest Service research has evolved since that time in response to changes in the needs and...

  17. Geophysical survey at archaeological sites in northeastern Syria

    OpenAIRE

    Mateiciucová, Inna; Milo, Peter; Tencer, Tomáš; Vlach, Marek

    2011-01-01

    From August 25 to September 4, 2008, geophysical surveys were carried out at the Neolithic, Chalcolithic, Bronze and Iron Age tell- and non-tell settlements in the Khabur region in Northeastern Syria (Syrian-Polish-Czech expedition) (Fig. 1). Four sites were prospected: Tell Arbid Abyad, Tell Arbid (West-hill), Khirbet Shane, Khirbet Bezi. The Scintrex Navmag SM-5 – Caesium Magnetometer was used for the measurement of the vertical gradient of the local magnetic field. The measurement resoluti...

  18. Early development of the south Central American margin: mechanisms and tectonic implications

    Science.gov (United States)

    Buchs, D. M.; Baumgartner, P. O.; Arculus, R.; Montes, C.; Bayona, G.; Cardona, A.

    2012-04-01

    regional unconformity in the forearc, migration of the Panamanian volcanic front and increased (apparent) rates of seamount accretion. This event may relate to large-scale plate reorganisation in the Pacific. New tectonostratigraphic, paleomagnetic, geochemical and geochronologic data from east Panama indicate that the easternmost margin was subsequently segmented and bended by a combination of strike-slip faulting, block rotation and orocline tightening. The segmentation suggests incipient collision of the south Central American arc with South America in the Late Eocene. This is much prior to Middle Miocene age indicated by an unconformity in the Chucunaque-Tuira basin at the eastern border of the margin, or Pliocene age associated to inter-American exchanges of terrestrial fauna and changes in the global ocean circulation.

  19. Status and management of moose in the northeastern United States

    Science.gov (United States)

    Wattles, David W.; DeStefano, Stephen

    2011-01-01

    Moose (Alces alces) populations have recolonized much of their historic range in the northeastern United States in the past 30 years, with their southern range edge extending to southern New England and northern New York. This southerly expansion occurred when certain other populations in the United States were in decline along the southern range edge, with climate change often cited as a probable cause. The areas that moose have recently occupied in the northeastern United States are some of the most densely human populated in moose range, which has raised concern about human safety and moose-vehicle collisions (MVC). We conducted a literature search about moose in the northeastern United States, and distributed a questionnaire and conducted phone interviews with regional biologists responsible for moose management to determine the status of moose, management activity, and research deficiencies and needs. Moose numbers appear stable throughout much of the region, with slow population growth in northern New York. Management activity ranges from regulated harvest of moose in Maine, New Hampshire, and Vermont, to no active management in southern New England and New York. The combined annual harvest in Maine, New Hampshire, and Vermont is >3,000. MVCs are a widespread regional concern with >1,000 occurring annually involving several human fatalities. Research should address impacts of parasitism by winter tick (Dermacentor albipictus) and brain-worm (Parelaphostrongylus tenuis) on productivity and mortality of moose, influence of climate change on population dynamics and range, and conflicts in areas with high human population density.

  20. HORTICOLA DIVERSITY FOR FOOD SECURITY MARGINALIZED MUNICIPALITIES IN STATE OF PUEBLA

    Directory of Open Access Journals (Sweden)

    Blanca Alicia Salcido-Ramos

    2013-04-01

    Full Text Available Backyards for rural households represent a strategy that ensures the production of plant foods and animal come to enrich and supplement their diet. Unfortunately there is no evidence of the contribution made by the horticultural component of biodiversity of species in relation to food, income generation and exchange of vegetables, based on the above plan the need for research aimed was to analyze the subsystem comprising the backyards vegetable operated by the State Program for Food Security (SPFS State establishing productive inputs, economic and social component that obtains horticultural peasant household (UDC, communities of Canoas- Atempan, Tezotepec-Mazatonal-Yaonáhuac Chignautla and the Northeastern Sierra Puebla state. In this northeastern region of 16 municipalities are located high deprivation and 8 highly marginalized state, population is of Náhuatl origin and it is common that women are responsible for the management and operation of the backyard based on their traditional knowledge and survival strategies. Fieldwork was conducted in the months of March to June 2011, with the participation of 37 rural women. Some of the findings are: Canoes and communities Mazatonal, 77% of horticultural production was assigned to food, 15% and 8% marketing to strengthen social relations within the community. In contrast, community of Tezotepec which earmarked 53% to the marketing, 46% to food and only 1% strengthening of social relations. There are also differences between communities in relation to the number of children, the diversity of vegetable grown, and the frequency of seeding and transplanting of vegetables contributing to the food security of the UDC.

  1. Seismic studies of crustal structure and tectonic evolution across the central California margin and the Colorado Plateau margin

    Science.gov (United States)

    Howie, John Mark

    This thesis presents results from two integrated deep-crustal seismic-reflection and wide-angle-reflection/refraction studies that improve our understanding of crustal structure and tectonic evolution in two tectonically active areas of the western United States. A multi-faceted approach to the study of crustal structure includes the use of compressional and shear wave seismic data. Supplementing the controlled source seismic observations with seismicity, gravity, heat flow, laboratory measurements and available geologic information allows a much improved understanding of crustal structure and tectonic evolution than would be available from the seismic data alone. Chapter 1 introduces the data integration strategy applied to the studies completed. In Chapter 2, an integrated crustal-velocity model across the south-central California margin west of the San Adreas fault is presented. The crustal structure defines tectonostratigraphic terranes 15 to 20 km thick underlain by a 6-km-thick high-velocity layer (6.8-7.0 km/s) interpreted as tectonically underplated oceanic crust. Structures defined in the oceanic crust indicate significant compressional and strike-slip deformation within the oceanic crust that probably formed during the final stages of subduction from 24-16 Ma. In Chapter 3, the crustal model from Chapter 2 is used as a constraint for models of the tectonic evolution of the Pacific-North American transform plate boundary. By combining the crustal structure with thermal models for asthenospheric upwelling associated with a slab-free window, I find that the mantle lithosphere east of the coast beneath south-central California probably delaminated from the oceanic crust, stranding the oceanic crust beneath the margin. In Chapter 4, results from a high-resolution reflection experiment in central Arizona across the southwestern edge of the Colorado Plateau address the relationship between strength of the crust and localization of extensional tectonism. A low

  2. A Miocene wave-dominated estuarine system in the Paraíba Basin, northeastern Brazil

    Science.gov (United States)

    Gandini, Rosana; Rossetti, Dilce de Fátima; Netto, Renata Guimarães; Góes, Ana Maria

    2017-11-01

    A number of publications have documented the effect of the Miocene transgression on several coasts of the world. However, this event is incompletely documented along the Brazilian margin, despite the existence of an impressive record of Miocene deposits exposed mostly as several coastal cliffs along more than 5000 km of distance. The transgressive nature of Miocene deposits, so far recognized only in a few localities of northeastern Brazil, needs to be amplified in order to better characterize the impact of the Miocene transgression in eastern South America. In this work, we provide facies analysis of early/middle Miocene strata exposed in the Paraíba Basin, northeastern Brazil, aiming reconstruct the depositional paleoenvironments and analyze their evolution within the context of relative sea-level fluctuations data. The results revealed deposits characterized by several features that were related to the action of tidal currents, such as alternating thicker/thinner forest packages, abundant reactivation surfaces, mud drapes and oppositely-dipping (herringbone) cross sets. These sedimentary structures were associated with an ichnological assemblage indicative of marine-influenced and brackish water, best represented by Ophiomorpha, Planolites-Palaeophycus-Thalassinoides and Thallassinoides-Planolites-Palaeophycus ichnofabrics. Sedimentation occurred in environments consisting of estuarine channel, estuarine central basin, tidal inlet/tidal channel, tidal delta/washover, tidal flat/shoal and foreshore, which were related to an estuarine setting, at least in part of a wave-dominated type. Analysis of facies stratal patterns led to suggest that the estuarine deposits of the Paraíba Basin reflect a rise in relative sea level probably during the transgressive and/or highstand stage of a depositional sequence formed directly overlying Cretaceous rocks. This rise can be correlated with the worldwide early/mid Miocene marine transgression. However, while the eustatic sea

  3. Central Equatorial Pacific Experiment (CEPEX)

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    The Earth's climate has varied significantly in the past, yet climate records reveal that in the tropics, sea surface temperatures seem to have been remarkably stable, varying by less than a few degrees Celsius over geologic time. Today, the large warm pool of the western Pacific shows similar characteristics. Its surface temperature always exceeds 27[degree]C, but never 31[degree]C. Heightened interest in this observation has been stimulated by questions of global climate change and the exploration of stabilizing climate feedback processes. Efforts to understand the observed weak sensitivity of tropical sea surface temperatures to climate forcing has led to a number of competing ideas about the nature of this apparent thermostat. Although there remains disagreement on the processes that regulate tropical sea surface temperature, most agree that further progress in resolving these differences requires comprehensive field observations of three-dimensional water vapor concentrations, solar and infrared radiative fluxes, surface fluxes of heat and water vapor, and cloud microphysical properties. This document describes the Central Equatorial Pacific Experiment (CEPEX) plan to collect such observations over the central equatorial Pacific Ocean during March of 1993.

  4. Pacific Northwest regional assessment program

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The Pacific Northwest (comprised of the states of Alaska, Idaho, Montana, Oregon, Washington and Wyoming) can by several measures be regarded as a national warehouse of fossil energy resources. This condition coupled with an evolving national policy stressing utilization of fossil fuels in the near term prior to development of more advanced technologies for energy supply, could result in the imposition of major changes in the region's environmental, socioeconomic and possibly health status. The objective of the Pacific Northwest Regional Assessment Program is to establish and exercise an integrated analytical assessment program for evaluation of these potential changes that may result from various energy development or conservation scenarios. After consideration of a variety of approaches to integrated assessment at a regional level, Pacific Northwest Laboratories (PNL) has concluded that dynamic simulation techniques provide the best available approach to evaluating the issues pertinent to the Northwest. As a result, the PNW Regional Assessment Program has been structured in a framework involving ten sectors. Each of these sectors involve their own submodels that receive information either from outside the model as exogenous inputs or from other sector submodels

  5. Extensive Gravity Sliding of Late Jurassic-Cretaceous Age along the Northern Yucatan Margin of the Gulf of Mexico

    Science.gov (United States)

    Steier, A.; Mann, P.

    2017-12-01

    Gravity slides on salt or shale detachment surfaces linking updip extension with down dip compression have been described from several margins of the Gulf of Mexico (GOM). In a region 250 km offshore from the southwestern coast of Florida, the late Jurassic section near Destin Dome and Desoto Canyon has undergone late Jurassic to Cretaceous gravity sliding and downdip dispersion of rigid blocks along the top of the underlying Louann salt. Yet there has been no previous study of similar structural styles on the slope and deep basin of its late Jurassic conjugate margin located 200 km offshore of the northern margin of the Yucatan Peninsula. This study describes an extensive area of Mesozoic gravity sliding from the northern Yucatan slope using a grid of 2D seismic data covering a 134,000 km2 area of the northern Yucatan margin tied to nine wells. These data allow the northern Yucatan margin to be divided into three slope and basinal provinces: 1) a 225 km length of the northeastern margin consisting of late Jurassic-Cretaceous section that is not underlain by salt, exhibits no gravity sliding features, and has sub-horizontal dips; 2) a 120 km length of the north-central Yucatan margin with gravity slide features characterized by an 80-km-wide updip zone of normal faults occupying the shelf edge and upper slope and a 50-km-wide downdip zone of folds and thrust faults at the base of the slope; the slide area exhibits multiple detached slide blocks composed of late Jurassic sandstones and marine mudstones separated by intervening salt rollers; growth wedges adjacent to listric, normal faults suggest a gradual and long-lived downdip motion of rigid fault blocks throughout much of the late Jurassic and Cretaceous rather than a catastrophic and instantaneous collapse of the shelf edge; the basal, normal detachment fault averages 3° in dip and is overlain by salt that varies from 0-500 ms in time thickness; by the end of the Cretaceous, most gravity sliding and vertical

  6. The marginal band system in nymphalid butterfly wings.

    Science.gov (United States)

    Taira, Wataru; Kinjo, Seira; Otaki, Joji M

    2015-01-01

    Butterfly wing color patterns are highly complex and diverse, but they are believed to be derived from the nymphalid groundplan, which is composed of several color pattern systems. Among these pattern systems, the marginal band system, including marginal and submarginal bands, has rarely been studied. Here, we examined the color pattern diversity of the marginal band system among nymphalid butterflies. Marginal and submarginal bands are usually expressed as a pair of linear bands aligned with the wing margin. However, a submarginal band can be expressed as a broken band, an elongated oval, or a single dot. The marginal focus, usually a white dot at the middle of a wing compartment along the wing edge, corresponds to the pupal edge spot, one of the pupal cuticle spots that signify the locations of color pattern organizing centers. A marginal band can be expressed as a semicircle, an elongated oval, or a pair of eyespot-like structures, which suggest the organizing activity of the marginal focus. Physical damage at the pupal edge spot leads to distal dislocation of the submarginal band in Junonia almana and in Vanessa indica, suggesting that the marginal focus functions as an organizing center for the marginal band system. Taken together, we conclude that the marginal band system is developmentally equivalent to other symmetry systems. Additionally, the marginal band is likely a core element and the submarginal band a paracore element of the marginal band system, and both bands are primarily specified by the marginal focus organizing center.

  7. On the use of marginal posteriors in marginal likelihood estimation via importance-sampling

    OpenAIRE

    Perrakis, K.; Ntzoufras, I.; Tsionas, E. G.

    2013-01-01

    We investigate the efficiency of a marginal likelihood estimator where the product of the marginal posterior distributions is used as an importance-sampling function. The approach is generally applicable to multi-block parameter vector settings, does not require additional Markov Chain Monte Carlo (MCMC) sampling and is not dependent on the type of MCMC scheme used to sample from the posterior. The proposed approach is applied to normal regression models, finite normal mixtures and longitudin...

  8. Phanerozoic polyphase orogenies recorded in the northeastern Okcheon Belt, Korea from SHRIMP U-Pb detrital zircon and K-Ar illite geochronologies

    Science.gov (United States)

    Jang, Yirang; Kwon, Sanghoon; Song, Yungoo; Kim, Sung Won; Kwon, Yi Kyun; Yi, Keewook

    2018-05-01

    We present the SHRIMP U-Pb detrital zircon and K-Ar illite 1Md/1M and 2M1 ages, suggesting new insight into the Phanerozoic polyphase orogenies preserved in the northeastern Okcheon Belt, Korea since the initial basin formation during Neoproterozoic rifting through several successive contractional orogens. The U-Pb detrital zircon ages from the Early Paleozoic strata of the Taebaeksan Zone suggest a Cambrian maximum deposition age, and are supported by trilobite and conodont biostratigraphy. Although the age spectra from two sedimentary groups, the Yeongwol and Taebaek Groups, show similar continuous distributions from the Late Paleoproterozoic to Early Paleozoic ages, a Grenville-age hiatus (1.3-0.9 Ga) in the continuous stratigraphic sequence from the Taebaek Group suggests the existence of different peripheral clastic sources along rifted continental margin(s). In addition, we present the K-Ar illite 1Md/1M ages of the fault gouges, which confirm fault formation/reactivation during the Late Cretaceous to Early Paleogene (ca. 82-62 Ma) and the Early Miocene (ca. 20-18 Ma). The 2M1 illite ages, at least those younger than the host rock ages, provide episodes of deformation, metamorphism and hydrothermal effects related to the tectonic events during the Devonian (ca.410 Ma) and Permo-Triassic (ca. 285-240 Ma). These results indicate that the northeastern Okcheon Belt experienced polyphase orogenic events, namely the Okcheon (Middle Paleozoic), Songrim (Late Paleozoic to Early Mesozoic), Daebo (Middle Mesozoic) and Bulguksa (Late Mesozoic to Early Cenozoic) Orogenies, reflecting the Phanerozoic tectonic evolution of the Korean Peninsula along the East Asian continental margin.

  9. Paleoceanography of the tropical eastern pacific ocean.

    Science.gov (United States)

    Grigg, R W; Hey, R

    1992-01-10

    The East Pacific Barrier (EPB) is the most effective marine barrier to dispersal of tropical shallow-water fauna in the world today. The fossil record of corals in the eastern Pacific suggests this has been true throughout the Cenozoic. In the Cretaceous, the EPB was apparently less effective in limiting dispersal. Equatorial circulation in the Pacific then appears to have been primarily east to west and the existence of oceanic atolls (now drowned guyots) in the eastern Pacific probably aided dispersal. Similarly, in the middle and early Mesozoic and late Paleozoic, terranes in the central tropical Pacific likely served as stepping stones to dispersal of tropical shelf faunas, reducing the isolating effect of an otherwise wider Pacific Ocean (Panthalassa).

  10. Indian Ocean warming modulates Pacific climate change

    Science.gov (United States)

    Luo, Jing-Jia; Sasaki, Wataru; Masumoto, Yukio

    2012-01-01

    It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain. Here we explore how the enhanced tropical Indian Ocean warming in recent decades favors stronger trade winds in the western Pacific via the atmosphere and hence is likely to have contributed to the La Niña-like state (with enhanced east–west Walker circulation) through the Pacific ocean–atmosphere interactions. Further analysis, based on 163 climate model simulations with centennial historical and projected external radiative forcing, suggests that the Indian Ocean warming relative to the Pacific’s could play an important role in modulating the Pacific climate changes in the 20th and 21st centuries. PMID:23112174

  11. Distributions with given marginals and statistical modelling

    CERN Document Server

    Fortiana, Josep; Rodriguez-Lallena, José

    2002-01-01

    This book contains a selection of the papers presented at the meeting `Distributions with given marginals and statistical modelling', held in Barcelona (Spain), July 17-20, 2000. In 24 chapters, this book covers topics such as the theory of copulas and quasi-copulas, the theory and compatibility of distributions, models for survival distributions and other well-known distributions, time series, categorical models, definition and estimation of measures of dependence, monotonicity and stochastic ordering, shape and separability of distributions, hidden truncation models, diagonal families, orthogonal expansions, tests of independence, and goodness of fit assessment. These topics share the use and properties of distributions with given marginals, this being the fourth specialised text on this theme. The innovative aspect of the book is the inclusion of statistical aspects such as modelling, Bayesian statistics, estimation, and tests.

  12. The marginal cost of public funds

    DEFF Research Database (Denmark)

    Kleven, Henrik Jacobsen; Kreiner, Claus Thustrup

    2006-01-01

    This paper extends the theory and measurement of the marginal cost of public funds (MCF) to account for labor force participation responses. Our work is motivated by the emerging consensus in the empirical literature that extensive (participation) responses are more important than intensive (hours...... of work) responses. In the modelling of extensive responses, we argue that it is crucial to account for the presence of non-convexities created by fixed work costs. In a non-convex framework, tax and transfer reforms give rise to discrete participation responses generating first-order effects...... on government revenue. These revenue effects make the marginal cost of funds higher and we show numerically that the implications for MCF tend to be substantial...

  13. Slope failure of chalk channel margins

    DEFF Research Database (Denmark)

    Gale, A.; Anderskouv, Kresten; Surlyk, Finn

    2015-01-01

    The importance of mass transport and bottom currents is now widely recognized in the Upper Cretaceous Chalk Group of Northern Europe. The detailed dynamics and interaction of the two phenomena are difficult to study as most evidence is based on seismic data and drill core. Here, field observations...... the south, here interpreted as gravitational settling of the chalk immediately adjacent to the channel margin. Detailed biostratigraphic studies and sedimentological observations provide evidence for at least two discrete collapse events and suggest the slumping to be the result of channel margin...... oversteepening rather than evidence for a regional tectonic phase. The described example thus serves as an analogue for processes commonly only inferred from subsurface data....

  14. Marginal Loss Calculations for the DCOPF

    Energy Technology Data Exchange (ETDEWEB)

    Eldridge, Brent [Federal Energy Regulatory Commission, Washington, DC (United States); Johns Hopkins Univ., Baltimore, MD (United States); O' Neill, Richard P. [Federal Energy Regulatory Commission, Washington, DC (United States); Castillo, Andrea R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-12-05

    The purpose of this paper is to explain some aspects of including a marginal line loss approximation in the DCOPF. The DCOPF optimizes electric generator dispatch using simplified power flow physics. Since the standard assumptions in the DCOPF include a lossless network, a number of modifications have to be added to the model. Calculating marginal losses allows the DCOPF to optimize the location of power generation, so that generators that are closer to demand centers are relatively cheaper than remote generation. The problem formulations discussed in this paper will simplify many aspects of practical electric dispatch implementations in use today, but will include sufficient detail to demonstrate a few points with regard to the handling of losses.

  15. 78 FR 61840 - Pacific Fishery Management Council (Pacific Council); Public Meetings

    Science.gov (United States)

    2013-10-04

    ... Proposals to Modify EFH 7. Electronic Monitoring Alternatives 8. Consideration of Inseason Adjustments 9... Fishery Management Council (Pacific Council); Public Meetings AGENCY: National Marine Fisheries Service... broadcast are given under SUPPLEMENTARY INFORMATION below. Council address: Pacific Fishery Management...

  16. Gridded multibeam bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry at 40m resolution surrounding Howland Island, within the Pacific Remote Island Areas - Central Pacific Ocean. Bottom coverage was achieved in...

  17. Biological data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

  18. Oceanographic data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

  19. Climate Prediction Center (CPC) East Pacific/ North Pacific Teleconnection Pattern Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the East Pacific/ North Pacific teleconnection pattern. The data spans the period 1950 to present. The index is derived from a rotated...

  20. Pacific Hake - Growth and natal origin of Pacific hake from the Georgia Basin DPS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific hake (Merluccius productus) is an abundant species residing along the Pacific coast from the Gulf of California to the Strait of Georgia. It is the most...

  1. Acoustic data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

  2. 76 FR 28422 - Fisheries of the Pacific Region; Western Pacific Region

    Science.gov (United States)

    2011-05-17

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XX57 Fisheries of the Pacific Region; Western Pacific Region AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Notification of determination of...

  3. Response to state comments on the revised draft northeastern regional characterization reports for the Crystalline Repository Project

    International Nuclear Information System (INIS)

    1985-08-01

    The purpose of this document is to respond to the comments received from the States of the Northeastern Region on the revised draft Northeastern Regional Characterization Reports (RCRs). The responses in this document indicate the manner in which the suggestions or comments received have been considered in modifying the revised draft Northeastern RCRs. Both general comments related to the overall Crystalline Repository Project (CRP) and comments on specific sections of the RCRs are addressed. This document responds to Northeastern State comments on both the revised draft Northeastern Regional Geologic Characterization Report (RGCR) and the revised draft Northeastern Regional Environmental Characterization Report (RECR)

  4. Neotectonics in the northern equatorial Brazilian margin

    Science.gov (United States)

    Rossetti, Dilce F.; Souza, Lena S. B.; Prado, Renato; Elis, Vagner R.

    2012-08-01

    An increasing volume of publications has addressed the role of tectonics in inland areas of northern Brazil during the Neogene and Quaternary, despite its location in a passive margin. Hence, northern South America plate in this time interval might have not been as passive as usually regarded. This proposal needs further support, particularly including field data. In this work, we applied an integrated approach to reveal tectonic structures in Miocene and late Quaternary strata in a coastal area of the Amazonas lowland. The investigation, undertaken in Marajó Island, mouth of the Amazonas River, consisted of shallow sub-surface geophysical data including vertical electric sounding and ground penetrating radar. These methods were combined with morphostructural analysis and sedimentological/stratigraphic data from shallow cores and a few outcrops. The results revealed two stratigraphic units, a lower one with Miocene age, and an upper one of Late Pleistocene-Holocene age. An abundance of faults and folds were recorded in the Miocene deposits and, to a minor extent, in overlying Late Pleistocene-Holocene strata. In addition to characterize these structures, we discuss their origin, considering three potential mechanisms: Andean tectonics, gravity tectonics related to sediment loading in the Amazon Fan, and rifting at the continental margin. Amongst these hypotheses, the most likely is that the faults and folds recorded in Marajó Island reflect tectonics associated with the history of continental rifting that gave rise to the South Atlantic Ocean. This study supports sediment deposition influenced by transpression and transtension associated with strike-slip divergence along the northern Equatorial Brazilian margin in the Miocene and Late Pleistocene-Holocene. This work records tectonic evidence only for the uppermost few ten of meters of this sedimentary succession. However, available geological data indicate a thickness of up to 6 km, which is remarkably thick for

  5. Systems considerations in seismic margin evaluations

    International Nuclear Information System (INIS)

    Buttermer, D.R.

    1987-01-01

    Increasing knowledge in the geoscience field has led to the understanding that, although highly unlikely, it is possible for a nuclear power plant to be subjected to earthquake ground motion greater than that for which the plant was designed. While it is recognized that there are conservatisms inherent in current design practices, interest has developed in evaluating the seismic risk of operating plants. Several plant-specific seismic probabilistic risk assessments (SPRA) have been completed to address questions related to the seismic risk of a plant. The results from such SPRAs are quite informative, but such studies may entail a considerable amount of expensive analysis of large portions of the plant. As an alternative to an SPRA, it may be more practical to select an earthquake level above the design basis for which plant survivability is to be demonstrated. The principal question to be addressed in a seismic margin evaluation is: At what ground motion levels does one have a high confidence that the probability of seismically induced core damage is sufficiently low? In a seismic margin evaluation, an earthquake level is selected (based on site-specific geoscience considerations) for which a stable, long-term safe shutdown condition is to be demonstrated. This prespecified earthquake level is commonly referred to as the seismic margin earthquake (SME). The Electric Power Research Institute is currently supporting a research project to develop procedures for use by the utilities to allow them to perform nuclear plant seismic margin evaluations. This paper describes the systems-related aspects of these procedures

  6. Evolved dispersal strategies at range margins

    OpenAIRE

    Dytham, Calvin

    2009-01-01

    Dispersal is a key component of a species's ecology and will be under different selection pressures in different parts of the range. For example, a long-distance dispersal strategy suitable for continuous habitat at the range core might not be favoured at the margin, where the habitat is sparse. Using a spatially explicit, individual-based, evolutionary simulation model, the dispersal strategies of an organism that has only one dispersal event in its lifetime, such as a plant or sessile anima...

  7. Marginal longitudinal semiparametric regression via penalized splines

    KAUST Repository

    Al Kadiri, M.

    2010-08-01

    We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models.

  8. Atlantic continental margin of the United States

    Science.gov (United States)

    Grow, John A.; Sheridan, Robert E.; Palmer, A.R.

    1982-01-01

    The objective of this Decade of North American Geology (D-NAG) volume will be to focus on the Mesozoic and Cenozoic evolution of the U.S. Atlantic continental margin, including the onshore coastal plain, related onshore Triassic-Jurassic rift grabens, and the offshore basins and platforms. Following multiple compressional tectonic episodes between Africa and North America during the Paleozoic Era that formed the Appalachian Mountains, the Mesozoic and Cenozoic Eras were dominated by tensional tectonic processes that separated Africa and North America. Extensional rifting during Triassic and Early Jurassic times resulted in numerous tensional grabens both onshore and offshore, which filled with nonmarine continental red beds, lacustrine deposits, and volcanic flows and debris. The final stage of this breakup between Africa and North America occurred beneath the present outer continental shelf and continental slope during Early or Middle Jurassic time when sea-floor spreading began to form new oceanic crust and lithosophere between the two continents as they drifted apart. Postrift subsidence of the marginal basins continued in response to cooling of the lithosphere and sedimentary loading.Geophysical surveys and oil-exploration drilling along the U.S. Atlantic continental margin during the past 5 years are beginning to answer many questions concerning its deep structure and stratigraphy and how it evolved during the rifting and early sea-floor-spreading stages of the separation of this region from Africa. Earlier geophysical studies of the U.S. continental margin used marine refraction and submarine gravity measurements. Single-channel seismic-reflection, marine magnetic, aeromagnetic, and continuous gravity measurements became available during the 1960s.

  9. Panoramic view of the Mexican Pacific Coastline

    Science.gov (United States)

    1993-01-01

    In this scenic panoramic view, the orbiter tail points toward the Mexican Pacific coastline (18.0N, 103.0W) near the international resort of Acapulco on the nearly cloud free eastern Pacific Ocean. Almost all of southern Mexico can be seen from Puerto Vallarta in the north to the Isthmus of Tehuantepec in the south. The cloud covered Gulf of Mexico at the horizon contrasts sharply with the blue Pacific.

  10. Ocean Margins Programs, Phase I research summaries

    Energy Technology Data Exchange (ETDEWEB)

    Verity, P. [ed.

    1994-08-01

    During FY 1992, the DOE restructured its regional coastal-ocean programs into a new Ocean Margins Program (OMP), to: Quantify the ecological and biogeochemical processes and mechanisms that affect the cycling, flux, and storage of carbon and other biogenic elements at the land/ocean interface; Define ocean-margin sources and sinks in global biogeochemical cycles, and; Determine whether continental shelves are quantitatively significant in removing carbon dioxide from the atmosphere and isolating it via burial in sediments or export to the interior ocean. Currently, the DOE Ocean Margins Program supports more than 70 principal and co-principal investigators, spanning more than 30 academic institutions. Research funded by the OMP amounted to about $6.9M in FY 1994. This document is a collection of abstracts summarizing the component projects of Phase I of the OMP. This phase included both research and technology development, and comprised projects of both two and three years duration. The attached abstracts describe the goals, methods, measurement scales, strengths and limitations, and status of each project, and level of support. Keywords are provided to index the various projects. The names, addresses, affiliations, and major areas of expertise of the investigators are provided in appendices.

  11. Marginalized Student Access to Technology Education

    Science.gov (United States)

    Kurtcu, Wanda M.

    The purpose of this paper is to investigate how a teacher can disrupt an established curriculum that continues the cycle of inequity of access to science, technology, engineering, and math (STEM) curriculum by students in alternative education. For this paper, I will focus on the technology components of the STEM curriculum. Technology in the United States, if not the world economy, is developing at a rapid pace. Many areas of day to day living, from applying for a job to checking one's bank account online, involve a component of science and technology. The 'gap' in technology education is emphasized between the 'haves and have-nots', which is delineated along socio-economic lines. Marginalized students in alternative education programs use this equipment for little else than remedial programs and credit recovery. This level of inequity further widens in alternative education programs and affects the achievement of marginalized students in credit recovery or alternative education classes instead of participation technology classes. For the purposes of this paper I focus on how can I decrease the inequity of student access to 21st century technology education in an alternative education program by addressing the established curriculum of the program and modifying structural barriers of marginalized student access to a technology focused curriculum.

  12. Pricing district heating by marginal cost

    International Nuclear Information System (INIS)

    Difs, Kristina; Trygg, Louise

    2009-01-01

    A vital measure for industries when redirecting the energy systems towards sustainability is conversion from electricity to district heating (DH). This conversion can be achieved for example, by replacing electrical heating with DH and compression cooling with heat-driven absorption cooling. Conversion to DH must, however, always be an economically attractive choice for an industry. In this paper the effects for industries and the local DH supplier are analysed when pricing DH by marginal cost in combination with industrial energy efficiency measures. Energy audits have shown that the analysed industries can reduce their annual electricity use by 30% and increase the use of DH by 56%. When marginal costs are applied as DH tariffs and the industrial energy efficiency measures are implemented, the industrial energy costs can be reduced by 17%. When implementing the industrial energy efficiency measures and also considering a utility investment in the local energy system, the local DH supplier has a potential to reduce the total energy system cost by 1.6 million EUR. Global carbon dioxide emissions can be reduced by 25,000 tonnes if the industrial energy efficiency measures are implemented and when coal-condensing power is assumed to be the marginal electricity source. (author)

  13. Origin and dynamics of depositionary subduction margins

    Science.gov (United States)

    Vannucchi, Paola; Morgan, Jason P.; Silver, Eli A.; Kluesner, Jared W.

    2016-06-01

    Here we propose a new framework for forearc evolution that focuses on the potential feedbacks between subduction tectonics, sedimentation, and geomorphology that take place during an extreme event of subduction erosion. These feedbacks can lead to the creation of a "depositionary forearc," a forearc structure that extends the traditional division of forearcs into accretionary or erosive subduction margins by demonstrating a mode of rapid basin accretion during an erosive event at a subduction margin. A depositionary mode of forearc evolution occurs when terrigenous sediments are deposited directly on the forearc while it is being removed from below by subduction erosion. In the most extreme case, an entire forearc can be removed by a single subduction erosion event followed by depositionary replacement without involving transfer of sediments from the incoming plate. We need to further recognize that subduction forearcs are often shaped by interactions between slow, long-term processes, and sudden extreme events reflecting the sudden influences of large-scale morphological variations in the incoming plate. Both types of processes contribute to the large-scale architecture of the forearc, with extreme events associated with a replacive depositionary mode that rapidly creates sections of a typical forearc margin. The persistent upward diversion of the megathrust is likely to affect its geometry, frictional nature, and hydrogeology. Therefore, the stresses along the fault and individual earthquake rupture characteristics are also expected to be more variable in these erosive systems than in systems with long-lived megathrust surfaces.

  14. Origin and dynamics of depositionary subduction margins

    Science.gov (United States)

    Vannucchi, Paola; Morgan, Jason P.; Silver, Eli; Kluesner, Jared W.

    2016-01-01

    Here we propose a new framework for forearc evolution that focuses on the potential feedbacks between subduction tectonics, sedimentation, and geomorphology that take place during an extreme event of subduction erosion. These feedbacks can lead to the creation of a “depositionary forearc,” a forearc structure that extends the traditional division of forearcs into accretionary or erosive subduction margins by demonstrating a mode of rapid basin accretion during an erosive event at a subduction margin. A depositionary mode of forearc evolution occurs when terrigenous sediments are deposited directly on the forearc while it is being removed from below by subduction erosion. In the most extreme case, an entire forearc can be removed by a single subduction erosion event followed by depositionary replacement without involving transfer of sediments from the incoming plate. We need to further recognize that subduction forearcs are often shaped by interactions between slow, long-term processes, and sudden extreme events reflecting the sudden influences of large-scale morphological variations in the incoming plate. Both types of processes contribute to the large-scale architecture of the forearc, with extreme events associated with a replacive depositionary mode that rapidly creates sections of a typical forearc margin. The persistent upward diversion of the megathrust is likely to affect its geometry, frictional nature, and hydrogeology. Therefore, the stresses along the fault and individual earthquake rupture characteristics are also expected to be more variable in these erosive systems than in systems with long-lived megathrust surfaces.

  15. Maximum Margin Clustering of Hyperspectral Data

    Science.gov (United States)

    Niazmardi, S.; Safari, A.; Homayouni, S.

    2013-09-01

    In recent decades, large margin methods such as Support Vector Machines (SVMs) are supposed to be the state-of-the-art of supervised learning methods for classification of hyperspectral data. However, the results of these algorithms mainly depend on the quality and quantity of available training data. To tackle down the problems associated with the training data, the researcher put effort into extending the capability of large margin algorithms for unsupervised learning. One of the recent proposed algorithms is Maximum Margin Clustering (MMC). The MMC is an unsupervised SVMs algorithm that simultaneously estimates both the labels and the hyperplane parameters. Nevertheless, the optimization of the MMC algorithm is a non-convex problem. Most of the existing MMC methods rely on the reformulating and the relaxing of the non-convex optimization problem as semi-definite programs (SDP), which are computationally very expensive and only can handle small data sets. Moreover, most of these algorithms are two-class classification, which cannot be used for classification of remotely sensed data. In this paper, a new MMC algorithm is used that solve the original non-convex problem using Alternative Optimization method. This algorithm is also extended for multi-class classification and its performance is evaluated. The results of the proposed algorithm show that the algorithm has acceptable results for hyperspectral data clustering.

  16. Marginal historiography: on Stekel's account of things.

    Science.gov (United States)

    Bos, Jaap

    2005-01-01

    Psychoanalytic historiography has been, and to a certain extent still is, written mainly from the victor's (Freud's) perspective. One of the first attempts to deliver an alternative account was published in 1926 by Wilhelm Stekel in a little-known paper entitled "On the History of the Analytical Movement," which he wrote in response to Freud's (1925) "An Autobiographical Study" as an attempt to supplement or even counter Freud's version. This paper offers a dialogical reading of Stekel's paper, focusing not on the question of whether or not Stekel was right, but on the problem of marginalization itself. What discursive processes contributed to the marginalization of Stekel's position, and in what sense could Stekel's paper be called an instance of self-marginalization? Analysing various intertextual links between Freud's and Stekel's accounts, the author finds that the two accounts were caught up in an antagonistic dialectic from which it was impossible to escape. Following this paper, an English translation of Stekel's 1926 account is presented here for the first time.

  17. GPS-determination of along-strike variation in Cascadia margin kinematics: Implications for relative plate motion, subduction zone coupling, and permanent deformation

    Science.gov (United States)

    Miller, M. Meghan; Johnson, Daniel J.; Rubin, Charles M.; Dragert, Herb; Wang, Kelin; Qamar, Anthony; Goldfinger, Chris

    2001-04-01

    High-precision GPS geodesy in the Pacific Northwest provides the first synoptic view of the along-strike variation in Cascadia margin kinematics. These results constrain interfering deformation fields in a region where typical earthquake recurrence intervals are one or more orders of magnitude longer than the decades-long history of seismic monitoring and where geologic studies are sparse. Interseismic strain accumulation contributes greatly to GPS station velocities along the coast. After correction for a simple elastic dislocation model, important residual motions remain, especially south of the international border. The magnitude of northward forearc motion increases southward from western Washington (3-7 mm/yr) to northern and central Oregon (˜9 mm/yr), consistent with oblique convergence and geologic constraints on permanent deformation. The margin-parallel strain gradient, concentrated in western Washington across the populated Puget Lowlands, compares in magnitude to shortening across the Los Angeles Basin. Thus crustal faulting also contributes to seismic hazard. Farther south in southern Oregon, north-westward velocities reflect the influence of Pacific-North America motion and impingement of the Sierra Nevada block on the Pacific Northwest. In contrast to previous notions, some deformation related to the Eastern California shear zone crosses northernmost California in the vicinity of the Klamath Mountains and feeds out to the Gorda plate margin.

  18. Crustal architecture and tectonic evolution of the Sergipe-Alagoas and Jacuípe basins, offshore northeastern Brazil

    Science.gov (United States)

    Mohriak, Webster Ueipass; Bassetto, Marcelo; Vieira, Ines Santos

    1998-03-01

    The Sergipe-Alagoas and the Jacuípe basins are divergent margin basins located in the South Atlantic Ocean, at the northeastern Brazilian margin. High-quality 18 s (two-way travel time) seismic reflection profiles, which extend from the coastline towards the boundary with the oceanic crust, were integrated with potential field data and calibrated with the results of several exploratory boreholes. When combined, these data provide evidence that the deep seismic reflectors in the deep-water region are related to the crustal architecture of the basin, rather than to sedimentary features. Arrays of high-impedance reflectors, previously interpreted as top of basement, probably correspond to detachment planes near the base of the crust, or to underplated igneous rocks above the Moho. The extensional processes that were active during rifting resulted in normal crustal faults that apparently detach near the seismic Moho in the deep-water region. These crustal faults control and rotate syn-rift sedimentary units along the margin. The seaward portion of the rift seems to have been uplifted and highly eroded during a post-break-up tectonic event. The deep seismic reflection profiles also indicate that the deep-water province is characterized by wedges of reflectors that dip seawards. These features probably correspond to seaward-dipping reflectors (SDR), which are composed of volcanic rocks marking the transition to oceanic crust. The SDR wedges are locally associated with volcanic intrusions. Several volcanic plugs in deep-water region are aligned with oceanic fracture zones that apparently penetrate through the whole crust and reach the upper mantle. On the other hand, there are some diapiric structures located near the boundary between continental and oceanic crust that bear evidence for deep-water salt tectonics.

  19. South Pacific Nuclear Free Zone Treaty

    International Nuclear Information System (INIS)

    1987-03-01

    On 8 August 1986 the Protocols to the South Pacific Nuclear Free Zone Treaty were adopted by the South Pacific Forum at its 17 th session, in Suva. The attached texts of the Protocols were formally communicated to the Director General by the Director of the South Pacific Bureau for Economic Co-operation (SPEC) and are herewith being circulated to all Member States for their information pursuant to a request made by the Director of SPEC. Following the deposit of the eighth instrument of ratification, the South Pacific Nuclear Free Zone Treaty entered into force on 11 December 1986 [es

  20. Intensification of the Northeast Pacific oxygen minimum zone during the Bölling-Alleröd warm period

    Science.gov (United States)

    Zheng, Yen; van Geen, Alexander; Anderson, Robert F.; Gardner, James V.; Dean, Walter E.

    2000-01-01

    Although climate records from several locations around the world show nearly synchronous and abrupt changes, the nature of the inferred teleconnection is still poorly understood. On the basis of preserved laminations and molybdenum enrichments in open margin sediments we demonstrate that the oxygen content of northeast Pacific waters at 800 m depth during the Bölling-Alleröd warm period (15–13 kyr) was greatly reduced. Existing oxygen isotopic records of benthic and planktonic foraminifera suggest that this was probably due to suppressed ventilation at higher latitudes of the North Pacific. Comparison with ventilation records for the North Atlantic indicates an antiphased pattern of convection relative to the North Pacific over the past 22 kyr, perhaps due to variations in water vapor transport across Central America.

  1. 76 FR 54739 - Pacific Halibut Fishery; Guideline Harvest Levels for the Guided Sport Fishery for Pacific...

    Science.gov (United States)

    2011-09-02

    ... Levels for the Guided Sport Fishery for Pacific Halibut in International Pacific Halibut Commission... 2011 Pacific halibut guideline harvest levels (GHLs) for the guided sport fishery in International... to inform the public about the 2011 GHLs for the guided sport fishery for halibut. The GHLs are...

  2. 78 FR 18323 - Pacific Halibut Fishery; Guideline Harvest Levels for the Guided Sport Fishery for Pacific...

    Science.gov (United States)

    2013-03-26

    ... Levels for the Guided Sport Fishery for Pacific Halibut in International Pacific Halibut Commission... 2013 Pacific halibut guideline harvest levels (GHLs) for the guided sport fishery in International... to inform the public about the 2013 GHLs for the guided sport fishery for halibut. The GHLs are...

  3. 78 FR 48861 - Western Pacific Fisheries; Approval of a Marine Conservation Plan for Pacific Insular Areas...

    Science.gov (United States)

    2013-08-12

    ....S. Exclusive Economic Zone (EEZ) adjacent to any Pacific Insular Area other than American Samoa, Guam, or the Northern Mariana Islands, that is, in the EEZ around the Pacific remote island areas (PRIA... National Oceanic and Atmospheric Administration RIN 0648-XC792 Western Pacific Fisheries; Approval of a...

  4. Is the Gop rift oceanic? A reevaluation of the Seychelles-India conjugate margins

    Science.gov (United States)

    Guan, Huixin; Werner, Philippe; Geoffroy, Laurent

    2016-04-01

    Gop Rift axis. We propose that the conspicuous buoyant central part of the Gop Rift is likely associated with a continental C-Block as described in a recent paper on conjugated VPMs8, at least in the southern part of the Gop Rift. The crust below the Laxmi basin is probably transitional continental i.e. strongly intruded. West of India and west of the Laxmi Ridge, the transition to the Carlsberg Basin occurs along a clearly-expressed transform fault, not through an extended and thinned continental margin. We reinterpret the whole system based on those observations and propositions, giving some explanations on controversial magnetic anomalies based on similar observations from the southern Atlantic Ocean. 1: Collier et al., 2008. Age of the Seychelles-India break-up. Earth and Planetary Science Letters. 2: Minshull et al., 2008. The relationship between riftingand magmatism in the northeastern Arabian Sea. Nature Geoscience. 3 : Armitage et al., 2010. The importance of rift history for volcanic margin. Nature. 4 : Krishna et al., 2006. Nature of the crust in the Laxmi Basin (14 degrees-20 degrees N), western continental margin of India. Tectonics. 5 : Misra et al., 2015. Repeat ridge jumps and microcontinent separation: insights from NE Arabian Sea. Marine and Petroleum Geology. 6 : Biswas, 1982. Rift basins in the western margin of India and their hydrocarbon prospects. Bull. Am. Assoc. Pet. Geol. 7 : Chatterjee et al., 2013. The longest voyage: Tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia. Gondwana Research. 8 : Geoffroy et al., 2015. Volcanic passive margins: anotherway to break up continents. Scientific Reports.

  5. Radial gravitational gliding on passive margins

    Science.gov (United States)

    Cobbold, P. R.; Szatmari, P.

    1991-03-01

    Gravitational gliding of uppermost sediments down a passive margin is possible if there is a basal layer of evaporite or other soft material to allow detachment. In examples from the Gulf of Mexico and the Brazilian margin, gliding has produced three main structural domains: an uppermost domain of downdip extension; an intermediate domain of rigid gliding; and a lowermost domain of downdip contraction. Domain boundaries are established by changes in slope. In this paper, we examine three kinds of gravitational gliding, depending on the paths followed by material particles. In ideal parallel gliding, particle paths are parallel straight lines, trending downslope. This should occur where the margin is perfectly straight. In ideal radial gliding, particle paths are radii of a circle and the margin is shaped like a circular cone. Natural margins will not have ideal shapes; but divergent gliding will tend to occur off coastal salients; convergent gliding, off coastal re-entrants. A simple kinematic model based on ductile behaviour illustrates some essential features of radial gliding. Changes in radius during divergent gliding produce strike-parallel extension; during convergent gliding, they produce strike-parallel contraction. Vertical strains also differ. Divergent gliding produces an uppermost domain of strong vertical thinning, balanced by extensions in all horizontal directions. Similarly, convergent gliding produces a lowermost domain of strong vertical thickening, balanced by contractions in all horizontal directions. These deformed states cannot be restored by simple techniques based on section balancing. We have done three experiments using analogue materials: sand, to model the brittle behaviour of sediments; silicone putty, to model the ductile behaviour of basal layers of evaporite. The experiments were properly scaled to account for gravitational forces. Experiment I reproduced convergent gliding above a basement with a conical upper surface. Strike

  6. Late glacial drainage systems along the northwestern margin of the Laurentide Ice Sheet

    Science.gov (United States)

    Lemmen, Donald S.; Duk-Rodkin, Alejandra; Bednarski, Jan M.

    The evolution of drainage systems along the retreating northwestern Laurentide Ice Sheet was complex. The interaction of ice-margin configuration, topography and glacioisostasy resulted in a network of meltwater rivers that variably overflowed to the Arctic and Pacific Oceans and to the Gulf of Mexico. Glacial lakes also changed dramatically in size and location during the period of deglaciation. At the last (and all time) glacial maximum, the ice sheet extended into the eastern Cordillera, blocking northward and eastward drainage to the Arctic Ocean. Some meltwater and most non-glacial runoff were diverted through the mountains to the Yukon River basin, into Alaska and the Pacific Ocean. Retreat from the glacial maximum prior to 21 ka BP allowed proglacial drainage from the western margin of the ice sheet to flow into the Beaufort Sea/Arctic Ocean. Deglaciation was rapid after about 13 ka BP, with the present route of the lower Mackenzie River established between 13 and 11.5 ka BP. Continued ice retreat led to significant southward expansion of the Mackenzie/Beaufort drainage basin at about 11.5 ka BP through drainage capture of glacial Lake Peace, which previously had drained southeastward into the Missouri River and to the Gulf of Mexico. Very rapid ice retreat between 10.5 and 10 ka BP allowed glacial lake McConnell to expand down-slope in contact with the ice margin. Numerous glacial lakes occurred along the northwestern margin of the ice sheet during the maximum and retreat phases. These include ice-dammed glacial Lake Old Crow, which occupied unglaciated terrain of the northern Yukon, and glacial Lake Peace, which utilized a number of outlets as it migrated eastward with the ice front along the Peace Valley. The largest glacial lakes in the region were the result of glacioisostatic depression reversing the regional drainage. The Mackenzie Phase of glacial Lake McConnell was the second largest Pleistocene lake in North America (> 215,000 km2). Late glacial

  7. Energy-resources map of the Circum-Pacific region, northeast quadrant, and explanatory notes

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, K.J.

    1985-01-01

    The Circum-Pacific Map Project is a cooperative international effort designed to show the relation of known energy and mineral resources to the major geologic features of the Pacific basin and surrounding continental areas. The map of the Northeast Quadrant depicts known energy deposits from Alaska to northern Peru. This multicolored map is published at a scale of 1:10,000,000 and attempts to provide a unified overview of the energy resources of the northeast part of the Circum-Pacific region. In the notes, sedimentary basins containing giant oil and gas field (greater than 500 million barrels or 3 trillion cubic feet) are shown on page-sized maps together with relevant geologic and production data. Major oil and gas fields along the Pacific margin of North and South America (greater than 100 million barrels and 600 billion cubic feet) are shown on index maps. Additional information is presented on coal, oil sand, and geothermal convection systems. The geologic map alone is worth a look, because it synthesizes a wealth of geologic data for an extremely large area. The map and booklet are successful in portraying the broad scope of energy resources present in the region.

  8. Malaria vectors in ecologically heterogeneous localities of the Colombian Pacific region.

    Directory of Open Access Journals (Sweden)

    Nelson Naranjo-Díaz

    Full Text Available The Colombian Pacific region is second nationally in number of malaria cases reported. This zone presents great ecological heterogeneity and Anopheles species diversity. However, little is known about the current spatial and temporal distribution of vector species. This study, conducted in three ecologically different localities of the Pacific region, aimed to evaluate the composition and distribution of Anopheles species and characterize transmission intensity. A total of 4,016 Anopheles mosquitoes were collected representing seven species. The composition and dominant species differed in each locality. Three species were infected with malaria parasites: Anopheles darlingi and An. calderoni were infected with Plasmodium falciparum and An. nuneztovari with Plasmodium vivax VK210 and VK247. Annual EIRs varied from 3.5-7.2 infective bites per year. These results confirm the importance of the primary vector An. nuneztovari in areas disturbed by human interventions, of An. darlingi in deforested margins of humid tropical rainforest and An. albimanus and the suspected vector An. calderoni in areas impacted by urbanization and large-scale palm oil agriculture close to the coast. This constitutes the first report in the Colombia Pacific region of naturally infected An. darlingi, and in Colombia of naturally infected An. calderoni. Further studies should evaluate the epidemiological importance of An. calderoni in the Pacific region.

  9. Advanced Marginality as a comparative research strategy in praxis:

    DEFF Research Database (Denmark)

    Larsen, Troels Schultz

    2018-01-01

    Urban Outcast and advanced marginality belongs to a theory culture rarely engaged in comparative urban studies. Here the potential of advanced marginality as a comparative research strategy is explored paying special attention to the concepts of epistemic reflexivity, analogical reasoning...

  10. The Morphometry of the Deep-Water Sinuous Mendocino Channel and the Immediate Environs, Northeastern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    James V. Gardner

    2017-11-01

    Full Text Available Mendocino Channel, a deep-water sinuous channel located along the base of Gorda Escarpment, was for the first time completely mapped with a multibeam echosounder. This study uses newly acquired multibeam bathymetry and backscatter, together with supporting multichannel seismic and sediment core data to quantitatively describe the morphometry of the entire Mendocino Channel and to explore the age and possible causes that may have contributed to the formation and maintenance of the channel. The first 42 km of the channel is a linear reach followed for the next 83.8 km by a sinuous reach. The sinuous reach has a sinuosity index of 1.66 before it changes back to a linear reach for the next 22.2 km. A second sinuous reach is 40.2 km long and the two reaches are separated by a crevasse splay and a large landslide that deflected the channel northwest towards Gorda Basin. Both sinuous reaches have oxbow bends, cut-off meanders, interior and exterior terraces and extensive levee systems. The lower sinuous reach becomes more linear for the next 22.2 km before the channel relief falls below the resolution of the data. Levees suddenly decrease in height above the channel floor mid-way along the lower linear reach close to where the channel makes a 90° turn to the southwest. The entire channel floor is smooth at the resolution of the data and only two large mounds and one large sediment pile were found on the channel floor. The bathymetry and acoustic backscatter, together with previously collected seismic data and box and piston cores provide details to suggest Mendocino Channel may be no older than early Quaternary. A combination of significant and numerous earthquakes and wave-loading resuspension by storms are the most likely processes that generated turbidity currents that have formed and modified Mendocino Channel.

  11. Where’s Waldo? A new commensal species, Waldo arthuri (Mollusca, Bivalvia, Galeommatidae, from the Northeastern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Paul Valentich-Scott

    2013-07-01

    Full Text Available A galeommatid bivalve mollusk, representing a new species, is described from off the coasts of California and Vancouver Island, British Columbia. The new bivalve has a commensal relationship with the heart urchin, Brisaster latifrons. It has been observed crawling between the oral spines of this urchin, frequently near the peristome. The bivalve has been recorded from 80 (Vancouver Island to 444 (southern California meters depth, in muddy sediments.In common with other galeommatoideans, the new species broods its young; however it differs from the large majority of commensal members in lacking planktotrophic larval development.Waldo arthuri, new species, has multiple morphological, ecological and developmental similarities to other members of the genus Waldo Nicol, 1966, from the southern Atlantic and Antarctic Oceans. This is most pronounced for the Argentine species, Waldo paucitentaculatus Zelaya & Ituarte, 2013, W. arthuri’s sister species in nuclear and mitochondrial gene trees. Despite this close relationship, W. arthuri is phylogentically distinct and possesses several hinge, shell sculpture, foot, and mantle tentacle characteristics that merit its description as new.

  12. 77 FR 59582 - Endangered and Threatened Wildlife; 90-Day Finding on Petitions To List the Northeastern Pacific...

    Science.gov (United States)

    2012-09-28

    ... discussing the species' status and trends, or in information describing impacts and threats to the species... for the species (e.g., population abundance and trends, productivity, spatial structure, age structure... be responding in a negative fashion; then we assess the potential significance of that negative...

  13. Cretaceous-Eocene provenance connections between the Palawan Continental Terrane and the northern South China Sea margin

    Science.gov (United States)

    Shao, Lei; Cao, Licheng; Qiao, Peijun; Zhang, Xiangtao; Li, Qianyu; van Hinsbergen, Douwe J. J.

    2017-11-01

    The plate kinematic history of the South China Sea opening is key to reconstructing how the Mesozoic configuration of Panthalassa and Tethyan subduction systems evolved into today's complex Southeast Asian tectonic collage. The South China Sea is currently flanked by the Palawan Continental Terrane in the south and South China in the north and the two blocks have long been assumed to be conjugate margins. However, the paleogeographic history of the Palawan Continental Terrane remains an issue of uncertainty and controversy, especially regarding the questions of where and when it was separated from South China. Here we employ detrital zircon U-Pb geochronology and heavy mineral analysis on Cretaceous and Eocene strata from the northern South China Sea and Palawan to constrain the Late Mesozoic-Early Cenozoic provenance and paleogeographic evolution of the region testing possible connection between the Palawan Continental Terrane and the northern South China Sea margin. In addition to a revision of the regional stratigraphic framework using the youngest zircon U-Pb ages, these analyses show that while the Upper Cretaceous strata from the Palawan Continental Terrane are characterized by a dominance of zircon with crystallization ages clustering around the Cretaceous, the Eocene strata feature a large range of zircon ages and a new mineral group of rutile, anatase, and monazite. On the one hand, this change of sediment compositions seems to exclude the possibility of a latest Cretaceous drift of the Palawan Continental Terrane in response to the Proto-South China Sea opening as previously inferred. On the other hand, the zircon age signatures of the Cretaceous-Eocene strata from the Palawan Continental Terrane are largely comparable to those of contemporary samples from the northeastern South China Sea region, suggesting a possible conjugate relationship between the Palawan Continental Terrane and the eastern Pearl River Mouth Basin. Thus, the Palawan Continental

  14. Blood types in Pacific salmon

    Science.gov (United States)

    Ridgway, G.L.; Klontz, G.W.

    1961-01-01

    Intraspecific differences in erythrocyte antigens (blood types) were shown to occur in four species of Pacific salmon, the sockeye or red salmon (Oncorhynchus nerka), the chinook or king salmon (0. tshawytscha), the chum salmon (O. keta), and the pink salmon (O. gorbuscha). Antisalmon-erythrocyte sera prepared in rabbits and chickens were used after absorption of species-specific antibodies. Some of these blood types were shown to differ in their frequency of occurrence between different geographic races. In addition, isoimmunizations were conducted on one race of sockeye salmon. Antisera of seven different specificities were prepared and at least eight different patterns of antigenic composition were displayed by the cells tested.

  15. Chirostylidae of Australia's western continental margin (Crustacea : Decapoda: Anomura), with the description of five new species.

    Science.gov (United States)

    Mccallum, Anna W; Poore, Gary C B

    2013-01-01

    Five new species from the squat lobster family Chirostylidae are described from the continental margin of western Australia: Uroptychus albus sp. nov., Uroptychus bardi sp. nov., Uroptychus jawi sp. nov., Uroptychus taylorae sp. nov., and Uroptychus worrorra sp. nov. New records of Indo-West Pacific species for Australia are: Gastroptychus brachyterus Baba, 2005, Gastroptychus investigatoris Alcock, 1899, Uroptychodes grandirostris (Yokoya, 1933), Uroptychodes inortenseni (Van Dam, 1939), Uroptychus scandens Benedict, 1902, Uroptychus ciliatus (Van Dam, 1933) and Uroptychus vandamae Baba, 1988. New distributional records are given for species previously recorded from Australia: Uroptychus flindersi Ahyong & Poore, 2004, Uroptychus hesperius Ahyong & Poore, 2004, Uroptychusjoloensis Van Dam, 1939, Uroptychus nigricapillis Alcock, 1901, and Uroptychus spinirostris (Ahyong & Poore, 2004). These new records expand the number of chirostylid species in Australia from 34 to 46. Keys to Australian species of the genera Gastroptychus, Uroptychodes and Uroptychus are provided.

  16. Distribution of a climate-sensitive species at an interior range margin

    Science.gov (United States)

    Ray, Chris; Beever, Erik; Rodhouse, Thomas J.

    2016-01-01

    Advances in understanding the factors that limit a species’ range, particularly in the context of climate change, have come disproportionately through investigations at range edges or margins. The margins of a species’ range might often correspond with anomalous microclimates that confer habitat suitability where the species would otherwise fail to persist. We addressed this hypothesis using data from an interior, climatic range margin of the American pika (Ochotona princeps), an indicator of relatively cool, mesic climates in rocky habitats of western North America. Pikas in Lava Beds National Monument, northeastern California, USA, occur at elevations much lower than predicted by latitude and longitude. We hypothesized that pika occurrence within Lava Beds would be associated primarily with features such as “ice caves” in which sub-surface ice persists outside the winter months. We used data loggers to monitor sub-surface temperatures at cave entrances and at non-cave sites, confirming that temperatures were cooler and more stable at cave entrances. We surveyed habitat characteristics and evidence of pika occupancy across a random sample of cave and non-cave sites over a 2-yr period. Pika detection probability was high (~0.97), and the combined occupancy of cave and non-cave sites varied across the 2 yr from 27% to 69%. Contrary to our hypothesis, occupancy was not higher at cave sites. Vegetation metrics were the best predictors of site use by pikas, followed by an edge effect and elevation. The importance of vegetation as a predictor of pika distribution at this interior range margin is congruent with recent studies from other portions of the species’ range. However, we caution that vegetation composition depends on microclimate, which might be the proximal driver of pika distribution. The microclimates available in non-cave crevices accessible to small animals have not been characterized adequately for lava landscapes. We advocate innovation in the

  17. 46 CFR 171.015 - Location of margin line.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Location of margin line. 171.015 Section 171.015... PERTAINING TO VESSELS CARRYING PASSENGERS General § 171.015 Location of margin line. (a) A vessel with a... (FP) and the after perpendicular (AP) is at least 12 inches (30.5 cm), the margin line must be located...

  18. 17 CFR 260.7a-19 - Margin for binding.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Margin for binding. 260.7a-19...) GENERAL RULES AND REGULATIONS, TRUST INDENTURE ACT OF 1939 Formal Requirements § 260.7a-19 Margin for... and documents filed as a part thereof, shall have a back or stitching margin of at least 11/2 inches...

  19. Quantifying motion for pancreatic radiotherapy margin calculation

    International Nuclear Information System (INIS)

    Whitfield, Gillian; Jain, Pooja; Green, Melanie; Watkins, Gillian; Henry, Ann; Stratford, Julie; Amer, Ali; Marchant, Thomas; Moore, Christopher; Price, Patricia

    2012-01-01

    Background and purpose: Pancreatic radiotherapy (RT) is limited by uncertain target motion. We quantified 3D patient/organ motion during pancreatic RT and calculated required treatment margins. Materials and methods: Cone-beam computed tomography (CBCT) and orthogonal fluoroscopy images were acquired post-RT delivery from 13 patients with locally advanced pancreatic cancer. Bony setup errors were calculated from CBCT. Inter- and intra-fraction fiducial (clip/seed/stent) motion was determined from CBCT projections and orthogonal fluoroscopy. Results: Using an off-line CBCT correction protocol, systematic (random) setup errors were 2.4 (3.2), 2.0 (1.7) and 3.2 (3.6) mm laterally (left–right), vertically (anterior–posterior) and longitudinally (cranio-caudal), respectively. Fiducial motion varied substantially. Random inter-fractional changes in mean fiducial position were 2.0, 1.6 and 2.6 mm; 95% of intra-fractional peak-to-peak fiducial motion was up to 6.7, 10.1 and 20.6 mm, respectively. Calculated clinical to planning target volume (CTV–PTV) margins were 1.4 cm laterally, 1.4 cm vertically and 3.0 cm longitudinally for 3D conformal RT, reduced to 0.9, 1.0 and 1.8 cm, respectively, if using 4D planning and online setup correction. Conclusions: Commonly used CTV–PTV margins may inadequately account for target motion during pancreatic RT. Our results indicate better immobilisation, individualised allowance for respiratory motion, online setup error correction and 4D planning would improve targeting.

  20. Lesser Himalayan sequences in Eastern Himalaya and their deformation: Implications for Paleoproterozoic tectonic activity along the northern margin of India

    Directory of Open Access Journals (Sweden)

    Dilip Saha

    2013-05-01

    Full Text Available Substantial part of the northern margin of Indian plate is subducted beneath the Eurasian plate during the Caenozoic Himalayan orogeny, obscuring older tectonic events in the Lesser Himalaya known to host Proterozoic sedimentary successions and granitic bodies. Tectonostratigraphic units of the Proterozoic Lesser Himalayan sequence (LHS of Eastern Himalaya, namely the Daling Group in Sikkim and the Bomdila Group in Arunachal Pradesh, provide clues to the nature and extent of Proterozoic passive margin sedimentation, their involvement in pre-Himalayan orogeny and implications for supercontinent reconstruction. The Daling Group, consisting of flaggy quartzite, meta-greywacke and metapelite with minor mafic dyke and sill, and the overlying Buxa Formation with stromatolitic carbonate-quartzite-slate, represent shallow marine, passive margin platformal association. Similar lithostratigraphy and broad depositional framework, and available geochronological data from intrusive granites in Eastern Himalaya indicate strikewise continuity of a shallow marine Paleoproterozoic platformal sequence up to Arunachal Pradesh through Bhutan. Multiple fold sets and tectonic foliations in LHS formed during partial or complete closure of the sea/ocean along the northern margin of Paleoproterozoic India. Such deformation fabrics are absent in the upper Palaeozoic–Mesozoic Gondwana formations in the Lesser Himalaya of Darjeeling-Sikkim indicating influence of older orogeny. Kinematic analysis based on microstructure, and garnet composition suggest Paleoproterozoic deformation and metamorphism of LHS to be distinct from those associated with the foreland propagating thrust systems of the Caenozoic Himalayan collisional belt. Two possibilities are argued here: (1 the low greenschist facies domain in the LHS enveloped the amphibolite to granulite facies domains, which were later tectonically severed; (2 the older deformation and metamorphism relate to a Pacific type

  1. Prevalence of refractive errors among school children in Northeastern Iran.

    Science.gov (United States)

    Rezvan, Farhad; Khabazkhoob, Mehdi; Fotouhi, Akbar; Hashemi, Hassan; Ostadimoghaddam, Hadi; Heravian, Javad; Azizi, Elham; Khorasani, Abbas Azimi; Yekta, Abbas Ali

    2012-01-01

    To determine the prevalence of refractive errors among schoolchildren in Northeastern Iran by age and gender. Using multistage random cluster sampling, 2020 schoolchildren 6-17 years of age were selected for this cross-sectional study. The participants totalled 1551 (response rate 76.8%) elementary and junior high school children (41.5% boys and 58.5% girls) from the northeast of Iran. Cycloplegic autorefraction was used to determine refractive error. Myopia was defined as a spherical equivalent (SE) of -0.50 dioptre (D) or worse, hyperopia as a SE of +2.00 D or more, and astigmatism as cylinder equal to or worse than -0.75 D. The prevalence of uncorrected, habitual and optimal visual acuity of 6/12 (0.30 logMAR) or worse in the better eye was 2.2%, 1.0%, and 0.2% respectively. The prevalence rates of myopia, hyperopia and astigmatism were 4.3% (95%CI: 3.3-5.3), 5.4% (95%CI: 4.3-6.5) and 11.5% (95%CI: 9.9-13.1) respectively and were not related to gender. The prevalence of myopia and against-the-rule astigmatism increased significantly with age (p prevalence of hyperopia significantly decreased with age (p prevalence of myopia in schoolchildren in Northeastern Iran is considerably lower than that of East Asian populations, but similar to many other populations, including South Africa, Chile and other countries of the Middle East. Whilst comparisons with other studies show that the prevalence of hyperopia and astigmatism in Northeastern Iran is higher than that of some countries, it is lower compared with others. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  2. Analysis of longitudinal variations in North Pacific alkalinity to improve predictive algorithms

    Science.gov (United States)

    Fry, Claudia H.; Tyrrell, Toby; Achterberg, Eric P.

    2016-10-01

    The causes of natural variation in alkalinity in the North Pacific surface ocean need to be investigated to understand the carbon cycle and to improve predictive algorithms. We used GLODAPv2 to test hypotheses on the causes of three longitudinal phenomena in Alk*, a tracer of calcium carbonate cycling. These phenomena are (a) an increase from east to west between 45°N and 55°N, (b) an increase from west to east between 25°N and 40°N, and (c) a minor increase from west to east in the equatorial upwelling region. Between 45°N and 55°N, Alk* is higher on the western than on the eastern side, and this is associated with denser isopycnals with higher Alk* lying at shallower depths. Between 25°N and 40°N, upwelling along the North American continental shelf causes higher Alk* in the east. Along the equator, a strong east-west trend was not observed, even though the upwelling on the eastern side of the basin is more intense, because the water brought to the surface is not high in Alk*. We created two algorithms to predict alkalinity, one for the entire Pacific Ocean north of 30°S and one for the eastern margin. The Pacific Ocean algorithm is more accurate than the commonly used algorithm published by Lee et al. (2006), of similar accuracy to the best previously published algorithm by Sasse et al. (2013), and is less biased with longitude than other algorithms in the subpolar North Pacific. Our eastern margin algorithm is more accurate than previously published algorithms.

  3. Rates and style of Cenozoic deformation around the Gonghe Basin, northeastern Tibetan Plateau

    Science.gov (United States)

    Craddock, William H.; Kirby, Eric; Zhang, Huiping; Clark, Marin K.; Champagnac, Jean-Daniel; Yuan, Daoyang

    2014-01-01

    The northeastern Tibetan Plateau constitutes a transitional region between the low-relief physiographic plateau to the south and the high-relief ranges of the Qilian Shan to the north. Cenozoic deformation across this margin of the plateau is associated with localized growth of fault-cored mountain ranges and associated basins. Herein, we combine detailed structural analysis of the geometry of range-bounding faults and deformation of foreland basin strata with geomorphic and exhumational records of erosion in hanging-wall ranges in order to investigate the magnitude, timing, and style of deformation along the two primary fault systems, the Qinghai Nan Shan and the Gonghe Nan Shan. Structural mapping shows that both ranges have developed above imbricate fans of listric thrust faults, which sole into décollements in the middle crust. Restoration of shortening along balanced cross sections suggests a minimum of 0.8–2.2 km and 5.1–6.9 km of shortening, respectively. Growth strata in the associated foreland basin record the onset of deformation on the two fault systems at ca. 6–10 Ma and ca. 7–10 Ma, respectively, and thus our analysis suggests late Cenozoic shortening rates of 0.2 +0.2/–0.1 km/m.y. and 0.7 +0.3/–0.2 km/m.y. along the north and south sides of Gonghe Basin. Along the Qinghai Nan Shan, these rates are similar to late Pleistocene slip rates of ∼0.10 ± 0.04 mm/yr, derived from restoration and dating of a deformed alluvial-fan surface. Collectively, our results imply that deformation along both flanks of the doubly vergent Qilian Shan–Nan Shan initiated by ca. 10 Ma and that subsequent shortening has been relatively steady since that time.

  4. Regional Gravity and Magnetic Studies of Crustal Structure in Northeastern Mexico and Their Tectonic Implications

    Science.gov (United States)

    Sanchez-Alvarez, R.; Urrutia-Fucugauchi, J.

    2006-05-01

    Detailed modeling of regional Bouguer gravity and aeromagnetic anomalies in northeastern Mexico permits documentation of the crustal structure and tectonic relationships of major structural features at the southern margin of the North American craton. This region has experienced a complex evolution with major events that include Paleozoic subduction and consumption of an ocean, subsequent collision of continental plates to form the supercontinent Pangaea, major faulting and deformation, middle Mesozoic fragmentation and rifting between North and South America, formation of the Gulf of Mexico and Caribbean, strike-slip lateral faulting, Laramide compression and Cenozoic extension. The Marathon-Ouachita system in northern Mexico shows the effects of strike-slip faulting and deformation, which can be traced from its potential field anomalies and oil- exploration borehole logs and data. Major tectonic elements from west to east are the foreland, frontal zone, interior zone, the Coahuila terrane, and a large elongated intrusive province. Remnants of the Permo-Triassic magmatic arc and exotic continental crust are present in the Coahuila and Gulf coast terranes. They are all affected by lateral faulting along roughly east-west regional faults, and, if the characterization of tectonic elements is correct, the proposed paleoreconstruction sets limits on the amount of lateral translation and regional crustal deformation in northern Mexico. Younger deformational episodes during the Cenozoic need to be accounted for in the tectonic reconstruction. The apparent displacement of the intrusive belt is of the order of 600-700 km. The intrusive belt and the Ouachita frontal and interior zones appear also fragmented and displaced in the Coahuila area by lateral faults such as San Marcos, China-Sierra Mojada, Barroteran, San Carlos and Sabinas. Displacement is less than that observed for the Mojave-Sonora megashear south of Monterrey area, as documented from the gravity and

  5. Age and growth of Spanish mackerel (Scomberomorus brasiliensis off the northeastern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Francisco de Nóbrega

    Full Text Available Age and growth of the Spanish mackerel (Scomberomorus brasiliensis caught off northeastern Brazil were determined. A total of 831 otoliths were examined - 296 from males (12 - 75 cm FL, 212 from females (11.5 - 72 cm FL and 323 from specimens of undetermined sex (12.4 - 75 cm FL. There was a high percentage of juveniles in the catches, resulting mainly from the use of gillnets. Marginal increment analysis of the otoliths indicated that the shortest distances from the last ring to the edge occurred from November to May, laying down just one ring annually. One to eight rings were found, with specimen lengths ranging from 11.5 to 75.8 cm. The Schunute model was used to determine what model was best fit the data, demonstrating that the specialized von Bertalanffy growth equation is the most appropriate. Curves were established for males (L∞ = 79.52 cm, K = 0.189, t0 = -0.384 year and females (L∞ = 109.18 cm, K = 0.114, t0 = -0.414 year, which resulted in distinct growth patterns between sexes. Based on the parameters estimated for the sexes separately, males have an approximate longevity of 15.5 years, whereas female longevity is 25.9 years. Specimens between 2 and 6 years of age represented 86% (n = 5,290 of the catch composition, characterizing the species as a catchable stock in the region. The present study updates essential information for assessing the stock of this important resource, for which the last growth studies in the region were carried out approximately thirty years ago.

  6. Processes of marginalization in relation to participation

    DEFF Research Database (Denmark)

    Lagermann, Laila Colding

    2011-01-01

    This paper discusses processes of marginalization in relation to the participation of two students, Amir and Saad, in the school in Copenhagen, Denmark, which they attend but also across the school and different communities outside the school. In the paper I discuss the effect of some teachers......’ (mis)interpellations of certain students like the two boys and further the problematic about how boys like Amir and Saad often struggle alone with contrasting ideologies of practice and the conflicts related to these contrasts....

  7. TENNESSEE WILLIAMS E O TEATRO MARGINAL GAY

    Directory of Open Access Journals (Sweden)

    Adriana Falqueto Lemos

    2014-09-01

    Full Text Available The work developed in this text aims to read the dramatist Tennnessee Williams in a play in two scenes “E Contar Tristes Histórias das Mortes das Bonecas” which was published in Brazil in the book “Mister Paradise e outras peças em um ato” (2011. The intention is to reflect upon one of his recurring themes, the marginalization. In order to perform the analysis, the theoretical support was grounded in “Literatura e Sociedade” by Antonio Candido (2006, concerning the participation of society and authorship in a piece of literature.

  8. Mangroves of the Pacific Islands: research opportunities

    Science.gov (United States)

    Ariel E. Lugo

    1990-01-01

    The perception of mangroves by people in the Pacific islands and throughout all the world has changed in the past decades. Today, the economic, social, ecologic, and esthetic values of mangroves are well recognized. Past research on these ecosystems is responsible for the change in perception. However, a review of eleven subjects relevant to the management of Pacific...

  9. Commonwealth Local Government Forum Pacific Project

    Directory of Open Access Journals (Sweden)

    Terry Parker

    2008-04-01

    Full Text Available The Commonwealth Local Government Forum (CLGF Pacific Project works with local government and other stakeholders in nine Pacific Island countries – Cook Islands, Fiji Islands, Kiribati, Samoa, Papua New Guinea, Solomon Islands, Tonga, Tuvalu and Vanuatu. It seeks to strengthen local democracy and good governance, and to help local governments deal with the increasing challenges of service delivery and urban management in the unique Pacific environment. Human settlement patterns in the region are changing rapidly. The Pacific has traditionally been a rural agricultural/subsistence society, but this is no longer the case. The accelerated pace of urbanisation has impacted significantly on Pacific nations and in the very near future the majority of Pacific Islanders will be found in urban areas. Already over 50% of Fiji’s population are urban dwellers. Rapid urbanisation brings with it unique challenges and opportunities. Local governments are at the forefront of this phenomenon, with the responsibility to manage urban development and the transition from rural areas to cities and towns. Their success or failure to manage urbanisation and provide the required levels of physical and social infrastructure will affect many lives in a new urban Pacific. The project now has three components – the main Pacific Regional Project and two country-specific programmes: the Honiara City Council Institutional Capacity Building Project and the Commonwealth Local Government Good Practice Scheme in Papua New Guinea.

  10. Sponges from Clipperton Island, East Pacific

    NARCIS (Netherlands)

    van Soest, R.W.M.; Kaiser, K.L.; van Syoc, R.

    2011-01-01

    Twenty sponge species (totalling 190 individuals) were collected during the 1938, 1994 and 2004/5 expeditions to the remote island of Clipperton in the East Pacific Ocean. Seven species are widespread Indo-Pacific sponges; nine species comprise sponges new to science; four species were represented

  11. Trans-pacific dust transport: integrated analysis of NASA/CALIPSO and a global aerosol transport model

    Directory of Open Access Journals (Sweden)

    K. Eguchi

    2009-05-01

    Full Text Available Detailed 3-D structures of Trans-Pacific Asian dust transport occurring during 5–15 May 2007 were investigated using the NASA/CALIOP vertical-resolved measurements and a three-dimensional aerosol model (SPRINTARS. Both CALIOP and SPRINTARS dust extinctions showed a good agreement along the way of the transport from the dust source regions across North Pacific into North America. A vertically two-layered dust distribution was observed over the northeastern Pacific and North America. The lower dust layer originated from a dust storm generated in the Gobi Desert on 5 May. It was transported at an altitude of around 4 km MSL and has mixed with Asian anthropogenic air pollutants during the course of transport. The upper dust layer mainly originated from a dust storm that occurred in the Taklimakan Desert 2–3 days after the Gobi dust storm generation. The upper dust cloud was transported in higher altitudes above the major clouds layer during the Trans-Pacific transport. It therefore has remained unmixed with the Asian air pollutants and almost unaffected by wet removal. The decay of its concentration level was small (only one-half after its long-distance transport crossing the Pacific. Our dust budget analysis revealed that the Asian dust flux passing through the longitude plane of 140° E was 2.1 Tg, and one third of that arrived North America. The cases analyzed in this study revealed that, while the Gobi Desert is an important source that can contribute to the long-range dust transport, the Taklimakan Desert appears to be another important source that can contribute to the dust transport occurring particularly at high altitudes.

  12. An instrumental earthquake catalogue for northeastern Italy since 1900

    International Nuclear Information System (INIS)

    Margottini, C.; Martini, G.; Slejko, D.

    1991-01-01

    An earthquake catalogue of instrumental data for northeastern Italy since 1900 is presented. The different types of magnitude, which are the main parameters of the present study, have been evaluated so as to be as homogeneous as possible. Comparisons of the different magnitude values show linear dependence, at least in the medium magnitude range represented by the available data set. Correlations between the magnitude most significant for this region and chosen macroseismic data indicate a methodology for assessing the macroseismic magnitude of historical earthquakes which seems to be stable. (author)

  13. Barriers and Opportunities for Sustainable Food Systems in Northeastern Kansas

    Directory of Open Access Journals (Sweden)

    Rhonda Janke

    2010-01-01

    Full Text Available Survey responses of producers and institutional buyers in northeastern Kansas (United States were analyzed to understand barriers and opportunities for sustainable food systems in the region where their emergence has been limited. Producers and buyers identified barriers previously noted regarding mismatches of available quantities and prices. Producers’ enthusiasm to supply locally exceeded buyers’ interest to source locally. Transportation was identified as one of the major concerns by producers, and their responses to choice tasks revealed producers’ preferences to sell locally while pricing their products to secure sales revenue and to cover their logistics expenses at least partially.

  14. Isotope hydrological evidence of geomorphological changes in northeastern Hungary

    International Nuclear Information System (INIS)

    Hertelendi, E.; Marton, L.; Miko, L.

    1992-01-01

    An isotope hydrological survey of groundwaters in the northeastern part of Hungary has shown a distribution of stable isotopic composition that cannot be explained by climatic changes alone. Detailed geomorphological studies have pointed out that during the Upper Pleniglacial and Late Glacial, the morphology of the territory, and consequently its catchment area, underwent considerable changes. Data gathered by the authors are consistent with the geomorphological results. The distribution of the isotopic composition data of groundwater provides evidence of both climatic changes and tectonic movements in the area. (author). 8 refs, 7 figs

  15. 40 CFR 81.79 - Northeastern Oklahoma Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.79 Section 81.79 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.79 Northeastern Oklahoma Intrastate Air Quality Control Region. The Metropolitan Tulsa Intrastate Air Quality Control Region has been renamed the Northeastern Oklahoma Intrastate...

  16. Pacific Northwest regional AGU meeting

    Science.gov (United States)

    Bentley, R.; Hinthome, J.

    The 28th Annual Pacific Northwest Regional American Geophysical Union Meeting, September 13-20, 1981, was hosted by the Department of Geology at Central Washington University, Ellensburg, Washington. A total of 31 papers was presented to the 91 registrants in two general sessions. Topics included seismology, general geophysics, volcanology, hydrology, oceanography, and two special symposia: Tectonics of the Columbia Plateau and Neogene —Quaternary Faults of the Pacific Northwest' and ‘Studies of the Eruption of Mount Saint Helens.’ Before and after the formal meetings, several field conferences were conducted to examine the Neogene tectonics of the Coast Range (Bob Bentley, Al Niem, and Ray Wells, leaders); the Columbia River Gorge (Bob Bentley, Marv Beeson, and Terry Tolan, leaders); the western Columbia Plateau northsouth transect (Bob Bentley and Jim Anderson, leaders); Quaternary structures of the Toppenish Ridge anticline (Don Tahkeal, Newell Campbell, and Bob Bentley, leaders); the Umtanum imbricate fault zone and pre-Saddle Mountains unconformity near Priest Rapids Dam (Ed Price and Bob Bentley, leaders); and the Yakima anticlines in the Cle Elum-Wallula deformed zone between Ellensburg and Yakima (Bob Bentley, leader).

  17. Seismicity of the Earth 1900-2010 eastern margin of the Australia plate

    Science.gov (United States)

    Benz, Harley M.; Herman, Matthew; Tarr, Arthur C.; Hayes, Gavin P.; Furlong, Kevin P.; Villaseñor, Antonio; Dart, Richard L.; Rhea, Susan

    2011-01-01

    The eastern margin of the Australia plate is one of the most seismically active areas of the world due to high rates of convergence between the Australia and Pacific plates. In the region of New Zealand, the 3,000 km long Australia-Pacific plate boundary extends from south of Macquarie Island to the southern Kermadec Island chain. It includes an oceanic transform (the Macquarie Ridge), two oppositely verging subduction zones (Puysegur and Hikurangi), and a transpressive continental transform, the Alpine Fault through South Island, New Zealand. Since 1900, there have been 15 M7.5+ earthquakes recorded near New Zealand. Nine of these, and the four largest, occurred along or near the Macquarie Ridge, including the 1989 M8.2 event on the ridge itself, and the 2004 M8.1 event 200 km to the west of the plate boundary, reflecting intraplate deformation. The largest recorded earthquake in New Zealand itself was the 1931 M7.8 Hawke's Bay earthquake, which killed 256 people. The last M7.5+ earthquake along the Alpine Fault was 170 years ago; studies of the faults' strain accumulation suggest that similar events are likely to occur again.

  18. Ice-Marginal Environments: Geomorphic and Structural Genesis of Marginal Moraines at Mýrdalsjökull

    DEFF Research Database (Denmark)

    Krüger, Johannes; Schomacker, A.; Benediktsson, Ívar Örn

    2010-01-01

    Ridge-shaped ice-marginal moraines paralleling the glacier margin are produced during glacier advances or stillstands, or they are formed by limited winter re-advances during overall glacier retreat. As ice-marginal moraines outline the configuration of glaciers, they are useful when interpreting...

  19. Source contribution analysis of surface particulate polycyclic aromatic hydrocarbon concentrations in northeastern Asia by source–receptor relationships

    International Nuclear Information System (INIS)

    Inomata, Yayoi; Kajino, Mizuo; Sato, Keiichi; Ohara, Toshimasa; Kurokawa, Jun-ichi; Ueda, Hiromasa; Tang, Ning; Hayakawa, Kazuichi; Ohizumi, Tsuyoshi; Akimoto, Hajime

    2013-01-01

    We analyzed the source–receptor relationships for particulate polycyclic aromatic hydrocarbon (PAH) concentrations in northeastern Asia using an aerosol chemical transport model. The model successfully simulated the observed concentrations. In Beijing (China) benzo[a]pyren (BaP) concentrations are due to emissions from its own domain. In Noto, Oki and Tsushima (Japan), transboundary transport from northern China (>40°N, 40–60%) and central China (30–40°N, 10–40%) largely influences BaP concentrations from winter to spring, whereas the relative contribution from central China is dominant (90%) in Hedo. In the summer, the contribution from Japanese domestic sources increases (40–80%) at the 4 sites. Contributions from Japan and Russia are additional source of BaP over the northwestern Pacific Ocean in summer. The contribution rates for the concentrations from each domain are different among PAH species depending on their particulate phase oxidation rates. Reaction with O 3 on particulate surfaces may be an important component of the PAH oxidation processes. -- Highlights: •Source–receptor analysis was conducted for investigating PAHs in northeast Asia. •In winter, transboundary transport from China is large contribution in leeward. •Relative contribution from Korea, Japan, and eastern Russia is increased in summer. •This seasonal variation is strongly controlled by the meteorological conditions. •The transport distance is different among PAH species. -- Transboundary transport of PAHs in northeast Asia was investigated by source–receptor analysis

  20. Ostracods biostratigraphy of the Oligocene-Miocene carbonate platform in the Northeastern Amazonia coast and its correlation with the Caribbean region

    Science.gov (United States)

    Nogueira, Anna Andressa Evangelista; Nogueira, Afonso César Rodrigues

    2017-12-01

    Oligocene-Miocene ostracods biozones are proposed for the ∼65 m-thick platform carbonate succession exposed in the Northeastern Amazonia coast, Brazil. Previous biostratigraphic studies based on planktonic foraminifera, nannofossils and palynomorphs are poorly age constrained and have hindered the correlation with other units of the Atlantic Equatorial margin. Tectonic stability of the Northeastern Amazonia coast during Neogene, associated with reduced riverine inflow and continuous sea level rise, allowed the establishment of lagoon/mangroves, tidal channel and shallow platform settings favoring massive proliferation of benthic ostracods. The recurrence of these depositional systems along of entire Oligocene-Miocene succession contributed mainly for the preservation of typical assemblages of lagoonal ostracods. Among thirty-two ostracods genera identified, the most of them are generally polyhalines associated with a mesohaline genus as Perissocytheridea. Rare ostracods genera typical of offshore zone indicate limited oceanic connection with lagoon. Additionally, the rare presence of Cyprideis indicates a relatively stable salinity degree suggesting change in the lagoon dynamic until estuarine conditions. The ostracods comprise more than 100 species, ranging from Upper Oligocene to Lower Miocene with five index species correspondent to a single zone called the Cytherella stainforthi Zone that was subdivided in four sub-biozones: 1) Jugosocythereis pannosa, 2) Quadracythere brachypygaia, 3) Triebelina crumena and 4) Neocaudites macertus. This new zonation was calibrated with the Blow's and Wade's planktonic foraminifers zones (N.3 to N.7 zones corresponding to O6 to M4b of Wade) and with van den Bold's zonation in the Neogene Caribbean region. Ostracod assemblages described here provide an excellent biostragraphic framework for local, intrabasinal and regional correlation for the Oligocene-Miocene deposits of the Northeastern Amazonia coast and Caribbean regions

  1. Late Miocene-Pliocene geomorphological evolution of the Xiaoshuizi peneplain in the Maxian Mountains and its tectonic significance for the northeastern Tibetan Plateau

    Science.gov (United States)

    Li, Jijun; Ma, Zhenhua; Li, Xiaomiao; Peng, Tingjiang; Guo, Benhong; Zhang, Jun; Song, Chunhui; Liu, Jia; Hui, Zhengchuang; Yu, Hao; Ye, Xiyan; Liu, Shanpin; Wang, Xiuxi

    2017-10-01

    As a remnant elevated peneplain, the Tangxian planation surface is widely distributed in North China and the Ordos Plateau. Further into the Tibetan Plateau (TP), the Main planation surface can also be traced across this, the highest plateau on the Earth's surface. What the relation is between these two planation surfaces and whether they represent the remnants of a unique planation surface remains open to question. As the intermediate region between the low-altitude North China and the high-altitude TP, the Maxian Mountains and such bilateral basins located in the northeastern TP margin retain a series of well-preserved geomorphic features such as planation surfaces, pediment surface, and the fluvial terraces of the Yellow River. When and how the Xiaoshuizi peneplain was formed are crucial questions to elucidate the geomorphic evolution of the northeastern TP and infer the tectonic history of the TP. Here we present two parallel red clay-loess drill cores from the uplifted Xiaoshuizi bedrock peneplain in the Maxian Mountains, which document both the upper formation age of the planation surface and the evolution of Asian aridification. Based on the integration of high-resolution magnetostratigraphy analysis and Pliocene mammal fossils, we demonstrate that the red clay-loess succession deposited on the Xiaoshuizi peneplain probably began to accumulate at 6.9 Ma, implying that the Xiaoshuizi peneplain had begun to form before this. These results support the hypothesis that the Xiaoshuizi planation surface is equivalent to Tangxian planation surface of North China and Main planation surface of the TP. Furthermore, the onset of red clay sequence may indicate that the Xiaoshuizi peneplain was ultimately destroyed by the intensive tectonic uplift of the northeastern TP before 6.9 Ma. Taking into account the synchronous Late Miocene red clay deposition between the Xiaoshuizi peneplain and central Chinese Loess Plateau (CLP), we propose that the onset of interior Asian

  2. HISTOPATHOLOGY OF MARGINAL SUPERFICIAL PERIODONTIUM AT MENOPAUSE

    Directory of Open Access Journals (Sweden)

    A. Georgescu

    2012-03-01

    Full Text Available Premises: Sexual hormones may affect the general health condition of women, as early as puberty, continuing during pregnancy and also after menopause. Variations of the hormonal levels may cause different – either local or general – pathological modifications. Sexual hormones may also affect periodontal status, favourizing gingival inflammations and reducing periodontal resistance to the action of the bacterial plaque. Scope: Establishment of the correlations between the debut or the manifestation of menopause and the modifications produced in the superficial periodontium. Materials and method: Clinical and paraclinical investigations were performed on female patients with ages between 45 and 66 years, involving macroscopic, microscopic and radiological recording of the aspect of the superificial periodontium (gingiva. Results: Analysis of the histological sections evidenced atrophic and involutive modifications in the marginal superficial periodontium of female patients at menopause. Conclusions: Sexual hormones intervene in the histological equilibrium of the marginal superficial periodontium, influencing the periodontal health status, which explains the correlation between the subjective symptomatology specific to menopause and the histopatological aspect at epithelial level.

  3. Research priorities for zoonoses and marginalized infections.

    Science.gov (United States)

    2012-01-01

    This report provides a review and analysis of the research landscape for zoonoses and marginalized infections which affect poor populations, and a list of research priorities to support disease control. The work is the output of the Disease Reference Group on Zoonoses and Marginalized Infectious Diseases of Poverty (DRG6), which is part of an independent think tank of international experts, established and funded by the Special Programme for Research and Training in Tropical Diseases (TDR), to identify key research priorities through review of research evidence and input from stakeholder consultations. The report covers a diverse range of diseases, including zoonotic helminth, protozoan, viral and bacterial infections considered to be neglected and associated with poverty. Disease-specific research issues are elaborated under individual disease sections and many common priorities are identified among the diseases such as the need for new and/or improved drugs and regimens, diagnostics and, where appropriate, vaccines. The disease-specific priorities are described as micro priorities compared with the macro level priorities which will drive policy-making for: improved surveillance; interaction between the health, livestock, agriculture, natural resources and wildlife sectors in tackling zoonotic diseases; and true assessment of the burden of zoonoses. This is one often disease and thematic reference group reports that have come out of the TDR Think Tank, all of which have contributed to the development of the Global Report search on Infectious Diseases of Poverty, available at: w.who.int/tdr/stewardship/global_report/en/index.html.

  4. Photogrammetric monitoring of glacier margin lakes

    Directory of Open Access Journals (Sweden)

    Christian Mulsow

    2015-07-01

    Full Text Available The growing number of glacier margin lakes that have developed due to glacier retreat have caused an increase of dangerous glacier lake outburst floods (GLOFs in several regions over the last decade. This normally causes a flood wave downstream the glacier. Typically, such an event takes few to several hours. GLOF scenarios may be a significant hazard to life, property, nature and infrastructure in the affected areas. A GLOF is usually characterized by a progressive water level drop. By observing the water level of the lake, an imminent GLOF-event can be identified. Common gauging systems are often not suitable for the measurement task, as they may be affected by ice fall or landslides in the lake basin. Therefore, in our pilot study, the water level is observed by processing images of a terrestrial camera system observing a glacier margin lake. The paper presents the basic principle of an automatic single-camera-based GLOF early warning system. Challenges and approaches to solve them are discussed. First, results from processed image sequences are presented to show the feasibility of the concept. Water level changes can be determined at decimetre precision.

  5. Task Group on Safety Margins Action Plan (SMAP). Safety Margins Action Plan - Final Report

    International Nuclear Information System (INIS)

    Hrehor, Miroslav; Gavrilas, Mirela; Belac, Josef; Sairanen, Risto; Bruna, Giovanni; Reocreux, Michel; Touboul, Francoise; Krzykacz-Hausmann, B.; Park, Jong Seuk; Prosek, Andrej; Hortal, Javier; Sandervaag, Odbjoern; Zimmerman, Martin

    2007-01-01

    The international nuclear community has expressed concern that some changes in existing plants could challenge safety margins while fulfilling all the regulatory requirements. In 1998, NEA published a report by the Committee on Nuclear Regulatory Activities on Future Nuclear Regulatory Challenges. The report recognized 'Safety margins during more exacting operating modes' as a technical issue with potential regulatory impact. Examples of plant changes that can cause such exacting operating modes include power up-rates, life extension or increased fuel burnup. In addition, the community recognized that the cumulative effects of simultaneous changes in a plant could be larger than the accumulation of the individual effects of each change. In response to these concerns, CSNI constituted the safety margins action plan (SMAP) task group with the following objectives: 'To agree on a framework for integrated assessments of the changes to the overall safety of the plant as a result of simultaneous changes in plant operation / condition; To develop a CSNI document which can be used by member countries to assess the effect of plant change on the overall safety of the plant; To share information and experience.' The two approaches to safety analysis, deterministic and probabilistic, use different methods and have been developed mostly independently of each other. This makes it difficult to assure consistency between them. As the trend to use information on risk (where the term risk means results of the PSA/PRA analysis) to support regulatory decisions is growing in many countries, it is necessary to develop a method of evaluating safety margin sufficiency that is applicable to both approaches and, whenever possible, integrated in a consistent way. Chapter 2 elaborates on the traditional view of safety margins and the means by which they are currently treated in deterministic analyses. This chapter also discusses the technical basis for safety limits as they are used today

  6. Increased salinization of fresh water in the Northeastern United States

    Science.gov (United States)

    Kaushal, S.S.; Groffman, P.M.; Likens, G.E.; Belt, K.T.; Stack, W.P.; Kelly, V.R.; Band, L.E.; Fisher, G.T.

    2005-01-01

    Chloride concentrations are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century. ?? 2005 by The National Academy of Sciences of the USA.

  7. Epibenthic community variability in the northeastern Chukchi Sea

    Science.gov (United States)

    Ravelo, Alexandra M.; Konar, Brenda; Trefry, John H.; Grebmeier, Jacqueline M.

    2014-04-01

    Epibenthic organisms can occur in large numbers and high biomass on the continental shelf of the northeastern Chukchi Sea. From an ecosystem perspective, epibenthic organisms are important in recycling and redistributing organic matter deposited from the pelagic zone, and they also are key members of the local food web. Data for biological (epibenthic species composition, abundance, and biomass) and environmental (bottom water temperature, salinity, dissolved oxygen and pH, sediment grain size, sediment organic matter and sediment chlorophyll content, latitude, longitude, and water depth) variables were collected at 53 stations in the northeastern Chukchi Sea during the summers of 2009-2010 to characterize the epibenthos and provide a benchmark for potential future changes due to possible anthropogenic disturbances. Community biomass, abundance, species composition and taxa richness varied in patches throughout the study area, but were generally dominated by crustaceans and echinoderms. These two groups had an inverse relationship in the distribution of their dominance. Communities dominated by crustaceans had significantly higher Simpson's dominance and Pielou's evenness values compared to echinoderm-dominated communities. Correlation coefficients for six environmental variables (longitude, bottom water temperature, water depth, bottom water dissolved oxygen, sediment grain size 2 phi and total organic carbon) with epifaunal abundance and biomass were moderate (0.42 for abundance and 0.51 for biomass at a significance level of 0.1%). However, assemblages within the study area followed a distinct spatial distribution pattern that matched the path of important water masses in the region.

  8. Northeastern Regional environmental characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    1985-08-01

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Maine, New Hampshire, Vermont, northeastern and southeastern New York, Massachusetts, Rhode Island, Connecticut, northern New Jersey, and eastern Pennsylvania. For each of the States within the Northeastern Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed Federal-protected lands, components of National Forest Lands, proximity to Federal-protected lands, existing State-protected lands, proximity to State-protected lands, population density and distribution, proximity to highly populated areas, or to 1-mile-square areas with 1000 or more persons, National and State forest lands, designated critical habitats for threatened and endangered species, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that will be of use at later phases of screening. Also included is a discussion of the relationship between the US Department of Energy Siting Guidelines (10 CFR 960) and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  9. Swinepox dermatitis in backyard pigs in Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Roberio G. Olinda

    2016-06-01

    Full Text Available Abstract: This article describes five outbreaks of swinepox in backyard pigs in Northeastern Brazil. It affected backyard pigs from herds of poor hygienic-sanitary conditions with severe fly and lice infestations. The morbidity ranged from 33.3 to 100% among affected herds, with mortality reaching up to 60%. The affected pigs developed multifocal to coalescent gray to white papules and blisters in the skin, with eventual eruptions, evolving to erosions and crusts. In addition to skin lesions, affected piglets presented apathy, anorexia and fever. The disease was auto-limiting, resolving within 15 to 25 days. Histological examination revealed proliferative and ulcerative vesiculopustular dermatitis with ballooning degeneration of epithelial cells, perivascular inflammatory infiltrates of lymphocytes, plasma cells, neutrophils, eosinophils and some macrophages in the dermis. Intracytoplasmic eosinophilic inclusions were consistently observed in keratinocytes. Total DNA extracted from fresh tissue fragments obtained from one outbreak and formalin-fixed, paraffin-embedded (FFPE tissue from the other four outbreaks was submitted to polymerase chain reaction (PCR for Swinepox virus (SWPV and Vaccinia virus (VACV. Genetic SWPV material was identified by PCR in fresh material from one outbreak. Nucleotide sequencing and phylogenetic analysis of the PCR amplicons (viral polymerase gene demonstrated 100% homology with sequences from SWPV. All tissues were PCR negative for VACV. Swine poxvirus is present in backyard pigs in Northeastern Brazil, indicating the need of including SWPV in the differential diagnosis of dermatitis in pigs.

  10. Haemodialysis services in the northeastern region of Iran

    Directory of Open Access Journals (Sweden)

    Behzad Kiani

    2017-05-01

    Full Text Available Chronic kidney disease is growing and the current estimated global prevalence exceeds 13%. As the use of haemodialysis machines for patients with end stage renal disease increases survival considerably, it is critical to plan correctly for the allocation of these machines. This study aimed to develop a geographical information systems (GIS-based approach to predict the need for this service in the northeastern region of Iran taking into account where patients live and where haemodialysis is the most needed and identifying areas with poor access to haemodialysis centres. Patients were interviewed to obtain self-reported actual travel time and the inverse distance-weighting algorithm was used to determine access in each area. The prediction is based on the domestic growth rate for haemodialysis services and the estimated active hours of machine use for the next five years. We estimate that six new haemodialysis machines are required in northeastern Iran at the present time with 50 machines required over the next five years. Ashkhane City was identified to have the least access to haemodialysis centres in the study area. Our GIS-based model can be used to investigate not only the need for new haemodialysis machines but also to examine geographic disparities in the allocation of haemodialysis centres and to identify areas most in need of this service. It is important that policymakers consider both spatial and non-spatial dimensions of access to enable better allocation of haemodialysis services ensuring they are targeted to reach those in need.

  11. Revised draft: Northeastern Regional environmental characterization report. Volume 1

    International Nuclear Information System (INIS)

    1984-11-01

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Maine, New Hampshire, Vermont, northeastern and southeastern New York, Massachusetts, Rhode Island, Connecticut, northern New Jersey, and eastern Pennsylvania. For each of the states within the Northeastern Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed federal protected lands, proximity to federal protected lands, existing state protected lands, proximity to state protected lands, population density and distribution, proximity to highly populated areas, national and state forest lands, state wildlife lands, designated critical habitats for threatened and endangered species, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that may be of use at later phases of screening. Also included is a discussion of the relationship between the US Department of Energy (DOE) Siting Guidelines and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  12. A Mycoplasma species of Emydidae turtles in the northeastern USA.

    Science.gov (United States)

    Ossiboff, Robert J; Raphael, Bonnie L; Ammazzalorso, Alyssa D; Seimon, Tracie A; Niederriter, Holly; Zarate, Brian; Newton, Alisa L; McAloose, Denise

    2015-04-01

    Mycoplasma infections can cause significant morbidity and mortality in captive and wild chelonians. As part of a health assessment of endangered bog turtles (Glyptemys muhlenbergii) in the northeastern US, choanal and cloacal swabs from these and other sympatric species, including spotted turtles (Clemmys guttata), eastern box turtles (Terrapene carolina carolina), wood turtles (Glyptemys insculpta), and common snapping turtles (Chelydra serpentina) from 10 sampling sites in the states (US) of Delaware, New Jersey, and Pennsylvania, were tested by PCR for Mycoplasma. Of 108 turtles tested, 63 (58.3%) were PCR positive for Mycoplasma including 58 of 83 bog turtles (70%), three of three (100%) eastern box turtles, and two of 11 (18%) spotted turtles; all snapping turtles (n = 7) and wood turtles (n = 4) were negative. Sequence analysis of portions of the 16S-23S intergenic spacer region and the 16S ribosomal RNA gene revealed a single, unclassified species of Mycoplasma that has been previously reported in eastern box turtles, ornate box turtles (Terrapene ornata ornata), western pond turtles (Emys marmorata), and red-eared sliders (Trachemys scripta elegans). We document a high incidence of Mycoplasma, in the absence of clinical disease, in wild emydid turtles. These findings, along with wide distribution of the identified Mycoplasma sp. across a broad geographic region, suggest this bacterium is likely a commensal inhabitant of bog turtles, and possibly other species of emydid turtles, in the northeastern US.

  13. Investigating Continental Margins: An Activity to Help Students Better Understand the Continental Margins of North America

    Science.gov (United States)

    Poli, Maria-Serena; Capodivacca, Marco

    2011-01-01

    Continental margins are an important part of the ocean floor. They separate the land above sea level from the deep ocean basins below and occupy about 11% of Earth's surface. They are also economically important, as they harbor both mineral resources and some of the most valuable fisheries in the world. In this article students investigate North…

  14. Talking (and Not Talking) about Race, Social Class and Dis/Ability: Working Margin to Margin

    Science.gov (United States)

    Ferri, Beth A.; Connor, David J.

    2014-01-01

    In this article we examine some of the omnipresent yet unacknowledged discourses of social and economic disadvantage and dis/ability within schools in the US. First, we document ways that social class, race, and dis/ability function within schools to further disadvantage and exclude already marginalized students. Next, we show how particular ways…

  15. Continental margin radiography from a potential field and sediment thickness standpoint: the Iberian Atlantic Margin

    Energy Technology Data Exchange (ETDEWEB)

    Catalan, M.; Martos, Y. M.; Martin-Davila, J.; Munoz-Martin, A.; Carbo, A.; Druet, M.

    2015-07-01

    This study reviews the state of knowledge in the Iberian Atlantic margin. In order to do this, the margin has been divided into three provinces: the Galicia margin, the southern Iberian abyssal plain, and the Tagus abyssal plain. We have used potential field and sediment thickness data. This has allowed us to study the crust, setting limits for the continental crust domain, and the amplitude of the so-called ocean-continent transition, whose end marks the beginning of the oceanic crust. The study shows the continental crust in the Galician margin to be the widest, about 210 km in length, whilst the ocean-continent transition varies slightly in this province: between 65 km wide in the south and 56 km wide in the north. This result shows up some differences with the hypothesis of other authors. The situation in the southern Iberian abyssal plain is nearly the opposite. Its continental crust extends approximately 60 km, whilst the ocean-continent transition zone is 185 km long. The Tagus abyssal plain study shows a faster morphological evolution than the others, according with the amount of crustal thinning β, the ocean-continent transition domain spanning 100 km. These results support a transitional intermediate character for almost the whole Tagus plain, in contrary to what other authors have stated. (Author)

  16. The tragedy of the margins: land rights and marginal lands in Vietnam (c. 1800-1945)

    NARCIS (Netherlands)

    Kleinen, J.

    2011-01-01

    This article deals with aspects of official land registers in pre-colonial and colonial Vietnam and their relationship with marginal lands since the eleventh century and especially since the beginning of the nineteenth century. The changing pattern of land ownership and control is studied in detail

  17. Autumn-winter minimum temperature changes in the southern Sikhote-Alin mountain range of northeastern Asia since 1529 AD

    Science.gov (United States)

    Ukhvatkina, Olga N.; Omelko, Alexander M.; Zhmerenetsky, Alexander A.; Petrenko, Tatyana Y.

    2018-01-01

    The aim of our research was to reconstruct climatic parameters (for the first time for the Sikhote-Alin mountain range) and to compare them with global climate fluctuations. As a result, we have found that one of the most important limiting factors for the study area is the minimum temperatures of the previous autumn-winter season (August-December), and this finding perfectly conforms to that in other territories. We reconstructed the previous August-December minimum temperature for 485 years, from 1529 to 2014. We found 12 cold periods (1535-1540, 1550-1555, 1643-1649, 1659-1667, 1675-1689, 1722-1735, 1791-1803, 1807-1818, 1822-1827, 1836-1852, 1868-1887, 1911-1925) and seven warm periods (1560-1585, 1600-1610, 1614-1618, 1738-1743, 1756-1759, 1776-1781, 1944-2014). These periods correlate well with reconstructed data for the Northern Hemisphere and the neighboring territories of China and Japan. Our reconstruction has 3-, 9-, 20-, and 200-year periods, which may be in line with high-frequency fluctuations in El Niño-Southern Oscillation (ENSO), the short-term solar cycle, Pacific Decadal Oscillation (PDO) fluctuations, and the 200-year solar activity cycle, respectively. We suppose that the temperature of the North Pacific, expressed by the PDO may make a major contribution to regional climate variations. We also assume that the regional climatic response to solar activity becomes apparent in the temperature changes in the northern part of Pacific Ocean and corresponds to cold periods during the solar minimum. These comparisons show that our climatic reconstruction based on tree ring chronology for this area may potentially provide a proxy record for long-term, large-scale past temperature patterns for northeastern Asia. The reconstruction reflects the global traits and local variations in the climatic processes of the southern territory of the Russian Far East for more than the past 450 years.

  18. Early Miocene depositional environments in the northern margin of the Mediterranean, southwestern Anatolia

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, H.H.; Oercen, S.

    1988-08-01

    The continental and shallow marine clastics and carbonates exposed around the towns of Kale and Acipayam in southwestern Anatolia were investigated to interpret the depositional environments in the northern margin of the Mediterranean in terms of lithofacies and biozones. These deposits include Miogypsina intermedia and M. irregularis, indicating Burdigalian age when correlated with the same species in the different parts of the Tethys Sea and Indian-Pacific Oceans. The clastic lower part of the succession is characterized by sheet flow and braided-stream deposits of an alluvial-fan/fan-delta complex. Marine carbonates overlie these deposits, but in some places a transgressive lag deposit lies between the unconformity surface and the carbonates. The lag deposit unit corresponds to the Gastropoda biozone, including Ostrea, Terebralia, and Pecten. Four carbonate facies are recognized: (1) Clayey limestones with ahermatypic corals, ostracods, macrofossils, and foraminifers. This facies corresponds to the Textularia-Rotalia biozone. (2) Packstones and grainstones with abundant nearshore and some offshore foraminifers, corresponding to the Miliolidae biozone. (3) Packstones and wackestones with offshore foraminifers. This facies includes the Miogypsina irregularis-Miogypsina intermedia biozone. (4) Boundstones and very poorly sorted reef-talus conglomerates including hermatypic corals, foraminifers, and binding foraminifers. This facies is the coral biozone. These sediments define the northern extent of the Tethys Sea in the investigated area during the Burdigalian. They were deposited in a shallow carbonate platform at the southern margin of the Anatolian mainland, which had a steep coast characterized by an alluvial-fan/fan-delta complex.

  19. Investigating the 3-D Subduction Initiation Processes at Transform Faults and Passive Margins

    Science.gov (United States)

    Peng, H.; Leng, W.

    2017-12-01

    Studying the processes of subduction initiation is a key for understanding the Wilson cycle and improving the theory of plate tectonics. Previous studies investigated subduction initiation with geological synthesis and geodynamic modeling methods, discovering that subduction intends to initiate at the transform faults close to oceanic arcs, and that its evolutionary processes and surface volcanic expressions are controlled by plate strength. However, these studies are mainly conducted with 2-D models, which cannot deal with lateral heterogeneities of crustal thickness and strength along the plate interfaces. Here we extend the 2-D model to a 3-D parallel subduction model with high computational efficiency. With the new model, we study the dynamic controlling factors, morphology evolutionary processes and surface expressions for subduction initiation with lateral heterogeneities of material properties along transform faults and passive margins. We find that lateral lithospheric heterogeneities control the starting point of the subduction initiation along the newly formed trenches and the propagation speed for the trench formation. New subduction tends to firstly initiate at the property changing point along the transform faults or passive margins. Such finds may be applied to explain the formation process of the Izu-Bonin-Mariana (IBM) subduction zone in the western Pacific and the Scotia subduction zone at the south end of the South America. Our results enhance our understanding for the formation of new trenches and help to provide geodynamic modeling explanations for the observed remnant slabs in the upper mantle and the surface volcanic expressions.

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

    Science.gov (United States)

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

    2007-05-01

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