Quaternary volcanism in Deception Island (Antarctica): South Shetland Trench subduction-related signature in the Bransfield Basin back arc domain

International Nuclear Information System (INIS)

Gale, C.; Ubide, T.; Lago, M.; Gil-Imaz, A.; Gil-Pena, I.; Galindo-Zaldivar, J.; Rey, J.; Maestro, A.; Lopez-Martinez, J.

2014-01-01

Deception Island shows a volcanism related to the Phoenix Plate subduction and roll-back under South Shetland Block in the present times. The development of the island is related to the evolution and collapse of a volcanic caldera, and this study is focused on the petrology, mineralogy and geochemistry of the post-caldera rocks. We have made a study of the lava flows, dikes and the youngest historic eruption in 1970. These rocks range from dacite to rhyolite and have a microporphyritic texture with olivine and minor clinopyroxene. A pre-caldera basaltic andesite has also been studied. It has a microporphyritic texture with clinopyroxene. The intermediate and acid compositions alternating in the volcanostratigraphic sequence suggest either mafic recharge events or melt extraction from different levels in the deep magmatic system. All the studied compositions share a subduction-related signature similar to other magmatics from the Bransfield Basin. However, compositional differences between pre-caldera and post-caldera rocks indicate a different magma source and depth of crystallisation. According to the geothermobarometric calculations the pre-caldera magmas started to crystallise at deeper levels (13.5-15 km) than the post-caldera magmas (6.2-7.8 km). Specifically, the postcaldera magmas indicate a smaller influence of the subducting slab in the southwestern part of the Bransfield Basin in respect to the available data from other sectors as well as the involvement of crustal contamination in the genesis of the magmas. (Author)

Tectonics in the Northwestern West Philippine Basin

Institute of Scientific and Technical Information of China (English)

Ni Xianglong; Wu Shiguo; Shinjo Ryuichi

2008-01-01

The West Philippine basin (WPB) is a currently inactive marginal basin belonging to Philippine Sea plate, which has a complex formation history and various crust structures. Based on gravity, magnetic and seismic data, the tectonics in West Philippine basin is characterized by amagnma spreading stage and strike slip fractures. NNE trending Okinawa-Luzon fracture zone is a large fracture zone with apparent geomorphology and shows a right-handed movement. The results of joint gravity-magnetic-seismic inversion suggest that the Okinawa-Luzon fracture zone has intensive deformation and is a transform fault. Western existence of the NW trending fractures under Ryukyu Islands Arc is the main cause of the differences between south and north Okinawa Trough. The Urdaneta plateau is not a remained arc, but remnant of mantle plume although its lava chemistry is similar to oceanic island basalt (OIB).

Drowned reefs and antecedent karst topography, Au'au channel, S.E. Hawaiian Islands

Science.gov (United States)

Grigg, R.W.; Grossman, E.E.; Earle, S.A.; Gittings, S.R.; Lott, D.; McDonough, J.

2002-01-01

During the last glacial maximum (LGM), about 21,000 years ago, the Hawaiian Islands of Maui, Lanai, and Molokai were interconnected by limestone bridges, creating a super-island known as Maui-Nui. Approximately 120 m of sea-level rise during the Holocene Transgression flooded, and then drowned, these bridges separating the islands by inter-island channels. A new multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles. The concentric basins contain flat lagoon-like bottoms that are rimmed by steep-sided limestone walls. Undercut notches rim the basins at several depths, marking either sea-level still stands or paleo-lake levels. All of the solution basins shallower than 120 m were subaerial at the LGM, and at one stage or another may have been shallow shoreline lakes. Today, about 70 drowned reef pinnacles are scattered across the Maui-Lanai underwater bridge and all are situated in wave-sheltered positions. Most drowned during the interval between 14,000 and 10,000 years ago when sea-level rise averaged 15 mm/year. Virtually all of the surficial topography in the Au'au Channel today is a product of karst processes accentuated by marginal reef growth during the Holocene. Both the submerged basins and the drowned reefs represent an archive of sea-level and climate history in Hawaii during the late Quaternary.

New aerogeophysical study of the Eurasia Basin and Lomonosov Ridge: Implications for basin development

DEFF Research Database (Denmark)

Brozena, J.M.; Childers, V.A.; Lawver, L.A.

2003-01-01

In 1998 and 1999, new aerogeophysical surveys of the Arctic Ocean's Eurasia Basin produced the first collocated gravity and magnetic measurements over the western half of the basin. These data increase the density and extend the coverage of the U.S. Navy acromagnetic data from the 1970s. The new...... data reveal prominent bends in the isochrons that provide solid geometrical constraints for plate reconstructions. Tentative identification of anomaly 25 in the Eurasia Basin links early basin opening to spreading in the Labrador Sea before the locus of spreading in the North Atlantic shifted...... to the Norwegian-Greenland Sea. With the opening of the Labrador Sea, Greenland began similar to200 km of northward movement relative to North America and eventually collided with Svalbard, Ellesmere Island, and the nascent Eurasia ocean basin. Both gravity and magnetic data sets reconstructed to times prior...

Macrobenthic community response to copper in Shelter Island Yacht Basin, San Diego Bay, California.

Science.gov (United States)

Neira, Carlos; Mendoza, Guillermo; Levin, Lisa A; Zirino, Alberto; Delgadillo-Hinojosa, Francisco; Porrachia, Magali; Deheyn, Dimitri D

2011-04-01

We examined Cu contamination effects on macrobenthic communities and Cu concentration in invertebrates within Shelter Island Yacht Basin, San Diego Bay, California. Results indicate that at some sites, Cu in sediment has exceeded a threshold for "self defense" mechanisms and highlight the potential negative impacts on benthic faunal communities where Cu accumulates and persists in sediments. At sites with elevated Cu levels in sediment, macrobenthic communities were not only less diverse but also their total biomass and body size (individual biomass) were reduced compared to sites with lower Cu. Cu concentration in tissue varied between species and within the same species, reflecting differing abilities to "regulate" their body load. The spatial complexity of Cu effects in a small marina such as SIYB emphasizes that sediment-quality criteria based solely on laboratory experiments should be used with caution, as they do not necessarily reflect the condition at the community and ecosystem levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of urban stormwater runoff on ground water beneath recharge basins on Long Island, New York

Science.gov (United States)

Ku, H.F.; Simmons, D.L.

1986-01-01

Urban stormwater runoff was monitored during 1980-82 to investigate the source, type, quantity, and fate of contaminants routed to the more than 3,000 recharge basins on Long Island and to determine whether this runoff might be a significant source of contamination to the groundwater reservoir. Forty-six storms were monitored at five recharge basins in representative land use areas (strip commercial, shopping-mall parking lot, major highway, low-density residential, and medium-density residential). Runoff:precipitation ratios indicate that all storm runoff is derived from precipitation on impervious surfaces in the drainage area, except during storms of high intensity or long duration, when additional runoff can be derived from precipitation on permeable surfaces. Lead was present in highway runoff in concentrations up to 3300 micrograms/L, and chloride was found in parking lot runoff concentrations up to 1,100 mg/L during winter, when salt is used for deicing. In the five composite stormwater samples and nine groundwater grab samples that were analyzed for 113 EPA-designated ' priority pollutants, ' four constituents were detected in concentrations exceeding New York State guidelines of 50 micrograms/L for an individual organic compound in drinking water: p-chloro-m-cresol (79 micrograms/L); 2 ,4-dimethylphenol (96 micrograms/L); 4-nitrophenol (58 micrograms/L); and methylene chloride (230 micrograms/L in either groundwater or stormwater at the highway basin). One stormwater sample and two groundwater samples exceeded New York State guidelines for total organic compounds in drinking water (100 micrograms/L). The presence of these constituents is attributed to contamination from point sources rather than to the quality of runoff from urban areas. The median number of indicator bacteria in stormwater ranged from 0.1 to 10 billion MPN/100 ml. Fecal coliforms and fecal streptococci increased by 1 to 2 orders of magnitude during the warm season. The use of recharge

Gravity Anomalies in the Northern Hawaiian Islands: Evidence for an Alternative Magma Chamber on Kauai and a Conjoined Niihau-Kauai Island

Science.gov (United States)

Flinders, A. F.; Ito, G.; Garcia, M.; Kim, S.; Appelgate, B.

2008-12-01

The shield stage evolution of the islands of Kauai and Niihau are poorly understood. Previous land-based gravity surveys provide only a coarse constraint on the observed gravitational field. Questions as to whether the island of Kauai was formed by a single or multiple shields and the developmental relationship between these neighboring islands are still debated. Our new land-based gravity survey of Kauai and ship-board gravity surveys around both islands identified large complete Bouguer gravitational anomalies under Kauai's Lihue Basin and offshore in the Kaulakahi Channel, a 30-km-long bathymetric ridge connecting the two islands. These gravitational highs are consistent in size and magnitude with those of other Hawaiian islands and imply local zones of high density crust, most likely attributed to magmatic intrusions; e.g. former magma chambers, or rift zones. The Lihue Basin anomaly observed is offset 20 km east from the geologically mapped caldera region. This offset implies either the unlikely case that the shield stage plumbing system connecting the magma chamber and caldera could have been inclined by up to 75 degrees from the vertical, or that the currently mapped caldera is a late feature, unrelated to shield volcanism. The location of the gravitational anomaly, in the Kaulakahi Channel, 20 km east of Niihau is consistent with geologic mapping, which indicates that Niihau is a remnant of an ancient shield volcano centered east of the island. The proximity of the Niihau gravitational anomaly 10 km from the western edge of Kauai supports the hypothesis that the two volcanoes were part of the same island.

Eocene to Miocene back-arc basin basalts and associated island arc tholeiites from northern Sulawesi (Indonesia): Implications for the geodynamic evolution of the Celebes basin; Basaltes de bassin arriere-arc de l`Eocene-Miocene et tholeiites d`arc insulaire associees du nord Sulawesi (Indonesie): implications pour l`evolution geodynamique du bassin des Celebes

Energy Technology Data Exchange (ETDEWEB)

Rangin, C. [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France); Maury, R.C.; Bellon, H.; Cotten, J. [Universite de Bretagne Occidentale, 29 - Brest (France); Polve, M. [Universite Paul Sabatier, 31 - Toulouse (France); Priadi, B.; Soeria-Atmadja, R. [Department of Geology, ITB, Bandung (Indonesia); Joron, J.L. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules

1997-12-31

Eocene BABB basalts intruded by tholeiitic and calk-alkalic island arc magmatic rocks are reported from the north arm of Sulawesi (Indonesia). Age and geochemical similarities between these basalts and those drilled in the Celebes Sea indicate this North Sulawesi volcanic arc was built on the same oceanic crust. The 25 deg late Neogene clockwise rotation of the north arm of Sulawesi following its collision with fragments of Australia (Sula, Buton) is not sufficient to explain the asymmetrical magnetic anomalies in the Celebes basin. The North Sulawesi island arc could be interpreted as having progressively retreated northward on its own Celebes sea back arc basin, during an episode of Palaeogene-early Neogene tectonic erosion along the trench. (authors) 37 refs.

Copper bioavailability and toxicity to Mytilus galloprovincialis in Shelter Island Yacht Basin, San Diego, CA.

Science.gov (United States)

Bosse, Casey; Rosen, Gunther; Colvin, Marienne; Earley, Patrick; Santore, Robert; Rivera-Duarte, Ignacio

2014-08-15

The bioavailability and toxicity of copper (Cu) in Shelter Island Yacht Basin (SIYB), San Diego, CA, USA, was assessed with simultaneous toxicological, chemical, and modeling approaches. Toxicological measurements included laboratory toxicity testing with Mytilus galloprovincialis (Mediterranean mussel) embryos added to both site water (ambient) and site water spiked with multiple Cu concentrations. Chemical assessment of ambient samples included total and dissolved Cu concentrations, and Cu complexation capacity measurements. Modeling was based on chemical speciation and predictions of bioavailability and toxicity using a marine Biotic Ligand Model (BLM). Cumulatively, these methods assessed the natural buffering capacity of Cu in SIYB during singular wet and dry season sampling events. Overall, the three approaches suggested negligible bioavailability, and isolated observed or predicted toxicity, despite an observed gradient of increasing Cu concentration, both horizontally and vertically within the water body, exceeding current water quality criteria for saltwater. Published by Elsevier Ltd.

Coastal inlets and tidal basins

NARCIS (Netherlands)

De Vriend, H.J.; Dronkers, J.; Stive, M.J.F.; Van Dongeren, A.; Wang, J.H.

2002-01-01

lecture note: Tidal inlets and their associated basins (lagoons) are a common feature of lowland coasts all around the world. A significant part ofthe world's coastlines is formed by barrier island coasts, and most other tidal coasts are interrupted by estuaries and lagoon inlets. These tidal

The Hack's law applied to young volcanic basin: the Tahiti case

Science.gov (United States)

Ye, F.; Sichoix, L.; Barriot, J.; Serafini, J.

2010-12-01

We study the channel morphology over the Tahiti island from the Hack’s law perspective. The Hack’s law is an empirical power relationship between basin drainage area and the length of its main channel. It had also been shown that drainage area becomes more elongate with increasing basin size. For typical continental basins, the exponent value lies between 0.47 for basins larger than 260,000 km2 and 0.7 for those spanning less than 20,720 km2 (Muller, 1973). In Tahiti, we extracted 27 principal basins ranging from 7 km2 to 90 km2 from a Digital Terrain Model of the island with a 5 m-resolution. We demonstrate that the Hack’s law still apply for such small basins (correlation coefficient R2=0.7) with an exponent value being approximately 0.5. It appears that the exponent value is influenced by the local geomorphic condition, and does not follow the previous study results (the exponent value decreases with increasing drainage area.) Our exponent value matches the result found w.r.t. debris-flow basins of China for drainage areas less than 100 km2 (Li et al., 2008). Otherwise, the young volcanic basins of Tahiti do not become longer and narrower with increasing basin size (R2=0.1). Besides, there is no correlation between the basin area and the basin convexity (R2=0). This means that there is no statistical change in basin shape with basin size. We present also the drainage area-slope relationship with respect to sediment or transport-limited processes. Key words: Hack’s law, channel morphology, DTM

Possible Late Pleistocene volcanic activity on Nightingale Island, South Atlantic Ocean, based on geoelectrical resistivity measurements, sediment corings and 14C dating

DEFF Research Database (Denmark)

Bjørk, Anders Anker; Björck, Svante; Cronholm, Anders

2011-01-01

. The irregular shapes of the basins and the lack of clear erosional features indicate that they are not eruption craters and were not formed by erosion. Instead, we regard them as morphological depressions formed between ridges of trachytic lava flows and domes at a late stage of the formation of the volcanic...... edifice. The onset of sedimentation within these basins appears to have occurred between 24 and 37 ka with the highest situated wetland yielding the highest ages. These ages are very young compared to the timing of the main phase of the formation of the island, implying volcanic activity on the island......Tristan da Cunha is a volcanic island group situated in the central South Atlantic. The oldest of these islands, Nightingale Island, has an age of about 18Ma. In the interior of the island, there are several wetlands situated in topographic depressions. The ages of these basins have been unknown...

Sedimentary architecture of a Plio-Pleistocene proto-back-arc basin: Wanganui Basin, New Zealand

Science.gov (United States)

Proust, Jean-Noël; Lamarche, Geoffroy; Nodder, Scott; Kamp, Peter J. J.

2005-11-01

The sedimentary architecture of active margin basins, including back-arc basins, is known only from a few end-members that barely illustrate the natural diversity of such basins. Documenting more of these basins types is the key to refining our understanding of the tectonic evolution of continental margins. This paper documents the sedimentary architecture of an incipient back-arc basin 200 km behind the active Hikurangi subduction margin, North Island, New Zealand. The Wanganui Basin (WB) is a rapidly subsiding, Plio-Pleistocene sedimentary basin located at the southern termination of the extensional back-arc basin of the active Central Volcanic Region (TVZ). The WB is asymmetric with a steep, thrust-faulted, outer (arc-ward) margin and a gentle inner (craton-ward) margin. It contains a 4-km-thick succession of Plio-Pleistocene sediments, mostly lying offshore, composed of shelf platform sediments. It lacks the late molasse-like deposits derived from erosion of a subaerial volcanic arc and basement observed in classical back-arc basins. Detailed seismic stratigraphic interpretations from an extensive offshore seismic reflection data grid show that the sediment fill comprises two basin-scale mega-sequences: (1) a Pliocene (3.8 to 1.35 Ma), sub-parallel, regressive "pre-growth" sequence that overtops the uplifted craton-ward margin above the reverse Taranaki Fault, and (2) a Pleistocene (1.35 Ma to present), divergent, transgressive, "syn-growth" sequence that onlaps: (i) the craton-ward high to the west, and (ii) uplifted basement blocks associated with the high-angle reverse faults of the arc-ward margin to the east. Along strike, the sediments offlap first progressively southward (mega-sequence 1) and then southeastward (mega-sequence 2), with sediment transport funnelled between the craton- and arc-ward highs, towards the Hikurangi Trough through the Cook Strait. The change in offlap direction corresponds to the onset of arc-ward thrust faulting and the rise of

Oxygen, hydrogen, and helium isotopes for investigating groundwater systems of the Cape Verde Islands, West Africa

Science.gov (United States)

Heilweil, V.M.; Solomon, K.D.; Gingerich, S.B.; Verstraeten, Ingrid M.

2009-01-01

Stable isotopes (??18O, ??2H), tritium (3H), and helium isotopes (3He, 4He) were used for evaluating groundwater recharge sources, flow paths, and residence times of three watersheds in the Cape Verde Islands (West Africa). Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. In contrast to other active oceanic hotspots, environmental tracers show that deep geothermal circulation does not strongly affect groundwater. Low tritium concentrations at seven groundwater sites indicate groundwater residence times of more than 50 years. Higher tritium values at other sites suggest some recent recharge. High 4He and 3He/4He ratios precluded 3H/3He dating at six sites. These high 3He/4He ratios (R/Ra values of up to 8.3) are consistent with reported mantle derived helium of oceanic island basalts in Cape Verde and provided end-member constraints for improved dating at seven other locations. Tritium and 3H/3He dating shows that S??o Nicolau Island's Ribeira Faj?? Basin has groundwater residence times of more than 50 years, whereas Fogo Island's Mosteiros Basin and Santo Ant??o Island's Ribeira Paul Basin contain a mixture of young and old groundwater. Young ages at selected sites within these two basins indicate local recharge and potential groundwater susceptibility to surface contamination and/or salt-water intrusion. ?? Springer-Verlag 2009.

The Flooding of Long Island Sound

Science.gov (United States)

Thomas, E.; Varekamp, J. C.; Lewis, R. S.

2007-12-01

Between the Last Glacial Maximum (22-19 ka) and the Holocene (10 ka) regions marginal to the Laurentide Ice Sheets saw complex environmental changes from moraines to lake basins to dry land to estuaries and marginal ocean basins, as a result of the interplay between the topography of moraines formed at the maximum extent and during stages of the retreat of the ice sheet, regional glacial rebound, and global eustatic sea level rise. In New England, the history of deglaciation and relative sea level rise has been studied extensively, and the sequence of events has been documented in detail. The Laurentide Ice Sheet reached its maximum extent (Long Island) at 21.3-20.4 ka according to radiocarbon dating (calibrated ages), 19.0-18.4 ka according to radionuclide dating. Periglacial Lake Connecticut formed behind the moraines in what is now the Long Island Sound Basin. The lake drained through the moraine at its eastern end. Seismic records show that a fluvial system was cut into the exposed lake beds, and a wave-cut unconformity was produced during the marine flooding, which has been inferred to have occurred at about 15.5 ka (Melt Water Pulse 1A) through correlation with dated events on land. Vibracores from eastern Long Island Sound penetrate the unconformity and contain red, varved lake beds overlain by marine grey sands and silts with a dense concentration of oysters in life position above the erosional contact. The marine sediments consist of intertidal to shallow subtidal deposits with oysters, shallow-water foraminifera and litoral diatoms, overlain by somewhat laminated sandy silts, in turn overlain by coarser-grained, sandy to silty sediments with reworked foraminifera and bivalve fragments. The latter may have been deposited in a sand-wave environment as present today at the core locations. We provide direct age control of the transgression with 30 radiocarbon dates on oysters, and compared the ages with those obtained on macrophytes and bulk organic carbon in

The Caledonian tectonomagmatic evolution of the Orkney Islands, Scotland

OpenAIRE

Bjerga, Audun Dalene

2017-01-01

The geology of the Orkney Islands is dominated by well-studied Devonian sedimentary rocks deposited in the Orcadian basin. However, on the islands of Mainland Orkney and Graemsay there are small, relatively poorly studied outcrops of the underlying basement. Based on comparison with rocks in mainland Scotland this basement has been suggested to comprise pre-Caledonian para-gneisses and Caledonian granites. This has, however, never been documented. Here the contact relationships in the basemen...

Covariation of climate and long-term erosion rates acrossa steep rainfall gradient on the Hawaiian island of Kaua'i

Science.gov (United States)

Ken Ferrier,; J. Taylor Perron,; Sujoy Mukhopadhyay,; Matt Rosener,; Stock, Jonathan; Slosberg, Michelle; Kimberly L. Huppert,

2013-01-01

Erosion of volcanic ocean islands creates dramatic landscapes, modulates Earth’s carbon cycle, and delivers sediment to coasts and reefs. Because many volcanic islands have large climate gradients and minimal variations in lithology and tectonic history, they are excellent natural laboratories for studying climatic effects on the evolution of topography. Despite concerns that modern sediment fluxes to island coasts may exceed long-term fluxes, little is known about how erosion rates and processes vary across island interiors, how erosion rates are influenced by the strong climate gradients on many islands, and how modern island erosion rates compare to long-term rates. Here, we present new measurements of erosion rates over 5 yr to 5 m.y. timescales on the Hawaiian island of Kaua‘i, across which mean annual precipitation ranges from 0.5 to 9.5 m/yr. Eroded rock volumes from basins across Kaua‘i indicate that million-year-scale erosion rates are correlated with modern mean annual precipitation and range from 8 to 335 t km–2 yr–1. In Kaua‘i’s Hanalei River basin, 3He concentrations in detrital olivines imply millennial-scale erosion rates of >126 to >390 t km–2 yr–1 from olivine-bearing hillslopes, while fluvial suspended sediment fluxes measured from 2004 to 2009 plus estimates of chemical and bed-load fluxes imply basin-averaged erosion rates of 545 ± 128 t km–2 yr–1. Mapping of landslide scars in satellite imagery of the Hanalei basin from 2004 and 2010 implies landslide-driven erosion rates of 30–47 t km–2 yr–1. These measurements imply that modern erosion rates in the Hanalei basin are no more than 2.3 ± 0.6 times faster than millennial-scale erosion rates, and, to the extent that modern precipitation patterns resemble long-term patterns, they are consistent with a link between precipitation rates and long-term erosion rates.

Reconstruction of the paleo-coastline of Santorini island (Greece ...

Indian Academy of Sciences (India)

history, changing dramatically the life of the people of the Bronze age in the eastern Mediterranean. Basin. It also changed the morphology of the island itself, creating the famous ..... Friedrich W 2001 Fire in the Sea. The Santorini Volcano:.

Structure of the la VELA Offshore Basin, Western Venezuela: AN Obliquely-Opening Rift Basin Within the South America-Caribbean Strike-Slip Plate Boundary

Science.gov (United States)

Blanco, J. M.; Mann, P.

2015-12-01

Bathymetric, gravity and magnetic maps show that the east-west trend of the Cretaceous Great Arc of the Caribbean in the Leeward Antilles islands is transected by an en echelon series of obliquely-sheared rift basins that show right-lateral offsets ranging from 20 to 40 km. The basins are 75-100 km in length and 20-30 km in width and are composed of sub-parallel, oblique slip normal faults that define deep, bathymetric channels that bound the larger islands of the Leeward Antilles including Aruba, Curacao and Bonaire. A single basin of similar orientation and structure, the Urumaco basin, is present to the southwest in the Gulf of Venezuela. We mapped structures and sedimentation in the La Vela rift basin using a 3D seismic data volume recorded down to 6 seconds TWT. The basin can be mapped from the Falcon coast where it is correlative with the right-lateral Adicora fault mapped onshore, and its submarine extension. To the southeast of the 3D survey area, previous workers have mapped a 70-km-wide zone of northeast-striking, oblique, right-lateral faults, some with apparent right-lateral offsets of the coastline. On seismic data, the faults vary in dip from 45 to 60 degrees and exhibit maximum vertical offsets of 600 m. The La Vela and other obliquely-opening rifts accommodate right-lateral shear with linkages to intervening, east-west-striking right-lateral faults like the Adicora. The zone of oblique rifts is restricted to the trend of the Great Arc of the Caribbean and may reflect the susceptiblity of this granitic basement to active shearing. The age of onset for the basins known from previous studies on the Leeward Antilles is early Miocene. As most of these faults occur offshore their potential to generate damaging earthquakes in the densely populated Leeward Antilles is not known.

Modeling of Wave Propagation in the Osaka Sedimentary Basin during the 2013 Awaji Island Earthquake (Mw5.8)

Science.gov (United States)

Asano, K.; Sekiguchi, H.; Iwata, T.; Yoshimi, M.; Hayashida, T.; Saomoto, H.; Horikawa, H.

2013-12-01

The three-dimensional velocity structure model for the Osaka sedimentary basin, southwest Japan is developed and improved based on many kinds of geophysical explorations for decades (e.g., Kagawa et al., 1993; Horikawa et al., 2003; Iwata et al., 2008). Recently, our project (Sekiguchi et al., 2013) developed a new three-dimensional velocity model for strong motion prediction of the Uemachi fault earthquake in the Osaka basin considering both geophysical and geological information by adding newly obtained exploration data such as reflection surveys, microtremor surveys, and receiver function analysis (hereafter we call UMC2013 model) . On April 13, 2013, an inland earthquake of Mw5.8 occurred in Awaji Island, which is close to the southwestern boundary of the aftershock area of the 1995 Kobe earthquake. The strong ground motions are densely observed at more than 100 stations in the basin. The ground motion lasted longer than four minutes in the Osaka urban area where its bedrock depth is about 1-2 km. This long-duration ground motions are mainly due to the surface waves excited in this sedimentary basin whereas the magnitude of this earthquake is moderate and the rupture duration is expected to be less than 5 s. In this study, we modeled long-period (more than 2s) ground motions during this earthquake to check the performance of the present UMC2013 model and to obtain a better constraint on the attenuation factor of sedimentary part of the basin. The seismic wave propagation in the region including the source and the Osaka basin is modeled by the finite difference method using the staggered grid solving the elasto-dynamic equations. The domain of 90km×85km×25.5km is modeled and discretized with a grid spacing of 50 m. Since the minimum S-wave velocity of the UMC2013 model is about 250 m/s, this calculation is valid up to the period of about 1 s. The effect of attenuation is included in the form of Q(f)=Q0(T0/T) proposed by Graves (1996). A PML is implemented in

The advance of Kos Plateau Tuff ignimbrite into the marine realm of the Kalymnos Basin, SE Aegean Sea.

Science.gov (United States)

Markakis, Emmanouil; Anastasakis, George

2013-04-01

The 161 ka Kos Plateau Tuff (KPT) eruption is considered to be the largest explosive Quaternary event in the eastern Mediterranean. It produced pumice rafts followed by "non-welded ignimbrites" that are up to 30m thick, especially widespread on Kos island and covering an area of > 80 Km2 that includes mainly islands and present marine regions. Pyroclastic flows travelled from the proposed vent, that lies between and around Yali and Nisyros islands, across present land and sea, the total volume of the tuff has been estimated as at least 100km3. KPT products principally consist of rhyolitic ash and pumice. Post 2010 Athens University oceanographic missions have mapped the seafloor around the volcanic islands of the SE Aegean Sea. Here we present new data on seafloor morphology and Upper Quaternary seafloor stratigraphy of the Kalymnos basin that extends over an area over 70km2 and map the advance and deposition of the KPT that was previously unknown in this region. The Kalymnos basin is roughly triangular in shape and essentially consists of two sedimentation depocenters: a) a roughly elliptical 400 m deep northern segment that is developed sub-parallel to Kalymnos Island and its W-SW shelf; b) a rather physiographically complex western sector developed NE of Astipalea island and reaching depths of over 620m. High resolution sparker profiles from the west Kos-Kalymnos shelf reveal an outstanding seismic stratigraphy of stacked and prograded coastal clinoform packets capped by erosional transgressive surfaces that record Quaternary eustatic lowstands deposits of sea level with clinoforms developing during forced regression and the erosional surfaces during transgression. We show that a massive gravity flow deposit is intercalated with the shelf sediments. Above it low sea level MIS 6 and 2 sedimentary sequences are fully developed and below stage 8-10 sediments are erratically preserved over stages 12 and 16 sediments. This gravity flow deposit swept across the shelf

The Third Pacific Basin Biofuels Workshop: Proceedings

Science.gov (United States)

Among the many compelling reasons for the development of biofuels on remote Pacific islands, several of the most important include: (1) a lack of indigenous fossil fuels necessitates their import at great economic loss to local island economics, (2) ideal conditions for plant growth exist on many Pacific islands to produce yields of biomass feedstocks, (3) gaseous and liquid fuels such as methane, methanol and ethanol manufactured locally from biomass feedstocks are the most viable alternatives to gasoline and diesel fuels for transportation, and (4) the combustion of biofuels is cleaner than burning petroleum products and contributes no net atmospheric CO2 to aggravate the greenhouse effect and the subsequent threat of sea level rise to low islands. Dr. Vic Phillips, HNEI Program Manager of the Hawaii Integrated Biofuels Research Program welcomed 60 participants to the Third Pacific Basin Biofuels Workshop at the Sheraton Makaha Hotel, Waianae, Oahu, on March 27 and 28, 1989. The objectives of the workshop were to update progress since the Second Pacific Basin Biofuels Workshop in April 1987 and to develop a plan for action for biofuels R and D, technology transfer, and commercialization now (immediate attention), in the near-term (less than two years), in the mid-term (three to five years), and in the long-term (more than six years). An emerging theme of the workshop was how the production, conversion, and utilization of biofuels can help increase environmental and economic security locally and globally. Individual papers are processed separately for the data base.

Surficial geology of the sea floor in Long Island Sound offshore of Plum Island, New York

Science.gov (United States)

McMullen, K.Y.; Poppe, L.J.; Danforth, W.W.; Blackwood, D.S.; Schaer, J.D.; Ostapenko, A.J.; Glomb, K.A.; Doran, E.F.

2010-01-01

The U.S. Geological Survey (USGS), the Connecticut Department of Environmental Protection, and the National Oceanic and Atmospheric Administration (NOAA) have been working cooperatively to interpret surficial sea-floor geology along the coast of the Northeastern United States. NOAA survey H11445 in eastern Long Island Sound, offshore of Plum Island, New York, covers an area of about 12 square kilometers. Multibeam bathymetry and sidescan-sonar imagery from the survey, as well as sediment and photographic data from 13 stations occupied during a USGS verification cruise are used to delineate sea-floor features and characterize the environment. Bathymetry gradually deepens offshore to over 100 meters in a depression in the northwest part of the study area and reaches 60 meters in Plum Gut, a channel between Plum Island and Orient Point. Sand waves are present on a shoal north of Plum Island and in several smaller areas around the basin. Sand-wave asymmetry indicates that counter-clockwise net sediment transport maintains the shoal. Sand is prevalent where there is low backscatter in the sidescan-sonar imagery. Gravel and boulder areas are submerged lag deposits produced from the Harbor Hill-Orient Point-Fishers Island moraine segment and are found adjacent to the shorelines and just north of Plum Island, where high backscatter is present in the sidescan-sonar imagery.

Human responses to Middle Holocene climate change on California's Channel Islands

Science.gov (United States)

Kennett, Douglas J.; Kennett, James P.; Erlandson, Jon M.; Cannariato, Kevin G.

2007-02-01

High-resolution archaeological and paleoenvironmental records from California's Channel Islands provide a unique opportunity to examine potential relationships between climatically induced environmental changes and prehistoric human behavioral responses. Available climate records in western North America (7-3.8 ka) indicate a severe dry interval between 6.3 and 4.8 ka embedded within a generally warm and dry Middle Holocene. Very dry conditions in western North America between 6.3 and 4.8 ka correlate with cold to moderate sea-surface temperatures (SST) along the southern California Coast evident in Ocean Drilling Program (ODP) Core 893A/B (Santa Barbara Basin). An episode of inferred high marine productivity between 6.3 and 5.8 ka corresponds with the coldest estimated SSTs of the Middle Holocene, otherwise marked by warm/low productivity marine conditions (7.5-3.8 ka). The impact of this severe aridity on humans was different between the northern and southern Channel Islands, apparently related to degree of island isolation, size and productivity of islands relative to population, fresh water availability, and on-going social relationships between island and continental populations. Northern Channel Islanders seem to have been largely unaffected by this severe arid phase. In contrast, cultural changes on the southern Channel Islands were likely influenced by the climatically induced environmental changes. We suggest that productive marine conditions coupled with a dry terrestrial climate between 6.3 and 5.8 ka stimulated early village development and intensified fishing on the more remote southern islands. Contact with people on the adjacent southern California Coast increased during this time with increased participation in a down-the-line trade network extending into the western Great Basin and central Oregon. Genetic similarities between Middle Holocene burial populations on the southern Channel Islands and modern California Uto-Aztecan populations suggest

Simulation of the Effects of Water Withdrawals, Wastewater Return Flows, and Land-Use Change on Streamflow in the Blackstone River Basin, Massachusetts and Rhode Island

Science.gov (United States)

Barbaro, Jeffrey R.

2007-01-01

Streamflow in many parts of the Blackstone River Basin in south-central Massachusetts and northern Rhode Island is altered by water-supply withdrawals, wastewater-return flows, and land-use change associated with a growing population. Simulations from a previously developed and calibrated Hydrological Simulation Program?FORTRAN (HSPF) precipitation-runoff model for the basin were used to evaluate the effects of water withdrawals, wastewater-return flows, and land-use change on streamflow. Most of the simulations were done for recent (1996?2001) conditions and potential buildout conditions in the future when all available land is developed to provide a long-range assessment of the effects of possible future human activities on water resources in the basin. The effects of land-use change were evaluated by comparing the results of long-term (1960?2004) simulations with (1) undeveloped land use, (2) 1995?1999 land use, and (3) potential buildout land use at selected sites across the basin. Flow-duration curves for these land-use scenarios were similar, indicating that land-use change, as represented in the HSPF model, had little effect on flow in the major tributary streams and rivers in the basin. However, land-use change?particularly increased effective impervious area?could potentially have greater effects on the hydrology, water quality, and aquatic habitat of the smaller streams in the basin. The effects of water withdrawals and wastewater-return flows were evaluated by comparing the results of long-term simulations with (1) no withdrawals and return flows, (2) actual (measured) 1996?2001 withdrawals and wastewater-return flows, and (3) potential withdrawals and wastewater-return flows at buildout. Overall, the results indicated that water use had a much larger effect on streamflow than did land use, and that the location and magnitude of wastewater-return flows were important for lessening the effects of withdrawals on streamflow in the Blackstone River Basin

Extended Late-Cretaceous Magnetostratigraphy of the James Ross Basin Island, Antarctica

Science.gov (United States)

Chaffee, T. M.; Mitchell, R.; Slotznick, S. P.; Buz, J.; Biasi, J.; O'Rourke, J.; Sousa, F.; Flannery, D.; Fu, R. R.; Kirschvink, J. L.

2017-12-01

Sediments in the James Ross Island Basin (JRB) in the West Antarctic Peninsula contain one of the world's highest-resolution records of the late Cretaceous period, including the end-Cretaceous (K-Pg) mass extinction event. However, the geological record of this region has been poorly studied, limited in the past only to the relative dating of local fossils. Recent studies of this region have provided only low-resolution data, with gaps of greater than 0.5 million years between samples where no data was collected. A high-resolution magnetostratigraphic sampling and analysis is necessary in order to accurately determine the age of the JRB sediments and connect them to the global time record. During the 2016 field season in Antarctica, our team collected nearly 1,300 sample cores from JRB sediments using a diamond-tipped, gasoline powered coring drill. Drill sites were densely clustered across bedding in order to obtain a high-resolution record of magnetostratigraphy, permitting the recognition of distinct, high-resolution units of time (group of over 300 of these samples from the Brandy Bay area which constrain the end of the Cretaceous Superchron (C34N) and the C34N/C34R reversal and allow us to investigate the presence of geomagnetic excursions before the end of superchron. These samples span in age from the top of C34N to the mid-Maastrichtian. We also test the Late Cretaceous True Polar Wander (TPW) hypothesis. Current theories on the global extent of TPW are not substantiated by any data sets that confirm the presence and similarity of the effect across multiple continents. Evidence of a rapid TPW oscillation in Antarctica can be correlated with other samples from the North American continent currently under study to provide evidence for the theory of global, short-timescale TPW.

Genetically depauperate in the continent but rich in oceanic islands: Cistus monspeliensis (Cistaceae in the Canary Islands.

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Mario Fernández-Mazuecos

Full Text Available BACKGROUND: Population genetic theory holds that oceanic island populations are expected to have lower levels of genetic variation than their mainland counterparts, due to founder effect after island colonization from the continent. Cistus monspeliensis (Cistaceae is distributed in both the Canary Islands and the Mediterranean region. Numerous phylogenetic results obtained in the last years allow performing further phylogeographic analyses in Cistus. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed sequences from multiple plastid DNA regions in 47 populations of Cistus monspeliensis from the Canary Islands (21 populations and the Mediterranean basin (26 populations. The time-calibrated phylogeny and phylogeographic analyses yielded the following results: (1 a single, ancestral haplotype is distributed across the Mediterranean, whereas 10 haplotypes in the Canary Islands; (2 four haplotype lineages are present in the Canarian Islands; (3 multiple colonization events across the archipelago are inferred; (4 the earliest split of intraspecific lineages occurred in the Early to Middle Pleistocene (<930,000 years BP. CONCLUSIONS/SIGNIFICANCE: The contrasting pattern of cpDNA variation is best explained by genetic bottlenecks in the Mediterranean during Quaternary glaciations, while the Canarian archipelago acted as a refugium of high levels of genetic diversity. Active colonization across the Canarian islands is supported not only by the distribution of C. monspeliensis in five of the seven islands, but also by our phylogeographic reconstruction in which unrelated haplotypes are present on the same island. Widespread distribution of thermophilous habitats on every island, as those found throughout the Mediterranean, has likely been responsible for the successful colonization of C. monspeliensis, despite the absence of a long-distance dispersal mechanism. This is the first example of a plant species with higher genetic variation among oceanic island

Wave Climate and Wave Response, Kawaihae Deep Draft Harbor, Island of Hawaii, Hawaii

National Research Council Canada - National Science Library

Thompson, Edward F; Demirbilek, Zeki; Briggs, Michael J

2006-01-01

Present and projected commercial activities in Kawaihae Deep Draft Harbor, Island of Hawaii, HI, indicate that a deeper basin and entrance channel and better protected berthing areas will be needed. The U.S...

Source-to-Sink System Evolution as Recorded in Clastic Facies in Two New Zealand Examples: the Bounty System of South Island and the Waipaoa System of North Island

Science.gov (United States)

Marsaglia, K. M.

2010-12-01

New Zealand river sources and their submarine sinks are excellent examples for modeling source-to-sink systems. In particular, the sand fractions of these systems can be used as tracers to document links and/or disconnects between fluvial, shelf, slope, and bathyal components. Within any given system, the ability to use sand as a tracer depends on the nature of the rocks exposed in source river drainage basins. In evolving systems, the potential for erosional unroofing, change of outcrop lithology through time, can be important. Additionally, the ability of a given lithology to generate sediment of a certain size may also vary. For example in the New Zealand examples, Cenozoic mudstones generate mostly mud but can liberate recycled sand grains (if present), as well as a smaller proportion of mudstone lithic fragments depending on degree of mudstone induration; schist generates copious sand and quartz-vein pebbles; and thin-bedded sandy turbidites can generate significant gravel, as well as mud and sand. Sediment production mode also comes into play with glacial processes (South Island) generating rock flour, as well as coarser debris. The major outcropping unit across both islands is a sedimentary to metasedimentary forearc succession, the Torlesse Terrane. It served as the protolith of the Otago schist (South Island) and the source of detritus for Cretaceous and Cenozoic sedimentary units on both islands. Local magmatism also supplied sand-sized material: intraplate (South Island) volcanism produced intrabasinal epiclastic debris and magmatic arc (North Island) volcanism produced extrabasinal pyroclastic debris. Various lithologies have characteristic detrital signatures. For example, in the Cenozoic units of the Waipaoa system, Pliocene calcareous mudstone fragments are key lithic components in tracing sediment transport from source-to sink, whereas the major fingerprint of Otago schist input into the Bounty System of South Island is mica. Critical to defining

Annotated bibliography of selected references on shoreline barrier island deposits with emphasis on Patrick Draw Field, Sweetwater County, Wyoming

Energy Technology Data Exchange (ETDEWEB)

Rawn-Schatzinger, V.; Schatzinger, R.A.

1993-07-01

This bibliography contains 290 annotated references on barrier island and associated depositional environments and reservoirs. It is not an exhaustive compilation of all references on the subject, but rather selected papers on barrier islands, and the depositional processes of formation. Papers that examine the morphology and internal architecture of barrier island deposits, exploration and development technologies are emphasized. Papers were selected that aid in understanding reservoir architecture and engineering technologies to help maximize recovery efficiency from barrier island oil reservoirs. Barrier islands from Wyoming, Montana and the Rocky Mountains basins are extensively covered.

Tectonics of East Siberian Sea Basin and its influence on petroleum systems

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Karpov, Yury; Antonina, Stoupakova; Anna, Suslova; Mariia, Agasheva

2016-04-01

The East Siberian Sea basin (ESSB) is the largest part of the Siberian Arctic shelf, extending for over 1000 km from New Siberian Islands archipelago to Wrangel Island. Nowadays East Siberian Sea margin is considered as a region with probable high petroleum potential. This part of Russian Arctic shelf is the least studied. The major problems in geological investigation of East Siberian Sea shelf are absence of deep wells in area and low seismic exploration maturity. Only general conclusions on its geology and hydrocarbon systems can be drawn based on limited seismic, gravity and magnetic data, supported by projection of onshore geological data to offshore. So, that's why now only complex geological and seismic stratigraphy interpretations are provided. Today we have several concepts and can summarize the tectonic history of the basin. The basin is filled with siliclastic sediments. In the deepest depocentres sediments thickness exceed 8 km in average. Seismic data was interpreted using methods of seismic stratigraphy. Stratigraphic interpretation was possible to achieve because seismic reflections follow chronostratigraphic correlations. Finally, main seismic horizons were indicated. Each indicated horizon follows regional stratigraphic unconformity. In case of absence of deep wells in ESSB, we can only prove possible source rocks by projection of data about New Siberian Islands archipelago source rocks on offshore. The petroleum potential of these rocks was investigated by several authors [1, 2, 3]. Perspective structures, investigated in ESSB were founded out by comparing seismogeological cross-sections with explored analogs in other Russian and foreign onshore and offshore basins. The majority of structures could be connected with stratigraphic and fault traps. New data on possible petroleum plays was analyzed, large massif of data on geology and tectonic history of the region was collected, so now we can use method of basin modelling to evaluate hydrocarbon

STUDY OF GAS POTENCY BASED ON GRAVITY ANOMALY MODELING AND SEISMIC PROFILE ANALYSIS AT BANGGAI-SULA BASIN

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Ediar Usman

2017-07-01

Full Text Available Banggai-Sula Basin is one of the basins with character of the micro-continent derived from northern part of Australia. Some traces the migration in the central part of Papua are slate, schist, and gneiss, current movement is facilitated by the Sorong Fault, which runs from the northern part of Papua to eastern part of Sulawesi. Results of gravity anomaly model (2D and 3D, seepage distribution, seismic and fields existing of oil and gas production in the western part of the Banggai-Sula Basin obtained a new prospect area in the northern part of Peleng Island, western part of Banggai Island, southern part of Banggai-Taliabu Islands, western and eastern part of Sulabesi Island. The new prospect area is reflected in the centre with form of the low morphology on gravity model and prospect trap on seismic data in the western part of Tolo Bay. Results of chemical analysis on the source rock of Buya Formation on Tmax vs Hydrogen Index (Tmax vs HI Diagram shows the type III kerogen quality and the Oxygen Index vs Hydrogen Index (OI vs HI Diagram shows the gas prone Type II, so that giving the impression that this area has the potential to containing the gas. The quality of the gas is included in the category of immature to mature type.

Water-quality assessment of the New England Coastal Basins in Maine, Massachusetts, New Hampshire, and Rhode Island : environmental settings and implications for water quality and aquatic biota

Science.gov (United States)

Flanagan, Sarah M.; Nielsen, Martha G.; Robinson, Keith W.; Coles, James F.

1999-01-01

The New England Coastal Basins in Maine, Massachusetts, New Hampshire, and Rhode Island constitute one of 59 study units selected for water-quality assessment as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program. England Coastal Basins study unit encompasses the fresh surface waters and ground waters in a 23,000 square-mile area that drains to the Atlantic Ocean. Major basins include those of the Kennebec, Androscoggin, Saco, Merrimack, Charles, Blackstone, Taunton, and Pawcatuck Rivers. Defining the environmental setting of the study unit is the first step in designing and conducting a multi-disciplinary regional water-quality assessment. The report describes the natural and human factors that affect water quality in the basins and includes descriptions of the physiography, climate, geology, soils, surface- and ground-water hydrology, land use, and the aquatic ecosystem. Although surface-water quality has greatly improved over the past 30 years as a result of improved wastewater treatment at municipal and industrial wastewater facilities, a number of water-quality problems remain. Industrial and municipal wastewater discharges, combined sewer overflows, hydrologic modifications from dams and water diversions, and runoff from urban land use are the major causes of water-quality degradation in 1998. The most frequently detected contaminants in ground water in the study area are volatile organic compounds, petroleum-related products, nitrates, and chloride and sodium. Sources of these contaminants include leaking storage tanks, accidental spills, landfills, road salting, and septic systems and lagoons. Elevated concentrations of mercury are found in fish tissue from streams and lakes throughout the study area.

Mechanics of Formation of Forearc Basins of Indonesia and Alaska

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Cassola, T.; Willett, S.; Kopp, H.

2010-12-01

In this study, the mechanics of forearc basins will be the object of a numerical investigation to understand the relationships between the wedge deformation and forearc basin formation. The aim of this work is to gain insight into the dynamics of the formation of the forearc basin on top of a deforming accretionary wedge, including the mechanism of formation of accommodation space and preservation of basin stratigraphy. Our tool is a two-dimensional numerical model that includes the rheological properties of the rock, including effective internal friction angle, effective basal friction angle, thermally-activated viscosity and strain softening. We also simulate different sedimentation rates in the basin, to study the influence of underfilled and overfilled basin conditions on wedge deformation. The stratigraphy in the basin is simulated, because, as noted in earlier studies, underfilled conditions incourage tectonic deformation in the inner wedge. We compare the numerical model to basins along the Sunda-Java Trench and the Alaskan margin. The Sunda-Java Trench shows a variety of structural and basin styles including underfilled and overfilled basins and different wedge geometries along the same trench. We interprete and document these structural styles, using depth migrated seismic sections of the Sunda Trench, obtained in three surveys, GINCO (11/98 - 01/99), MERAMEX (16/09/04 - 7/10/04) and SINDBAD (9/10/06 - 9/11/06) and made available by the IFM-GEOMAR group in Kiel and the Bundesanstalt für Geowissenschaften and Rohstoffe (BGR) in Hannover. On the Alaska margin we focus on the Kenai Peninsula, Kodiak Island plateau. This segment of the margin has one of the largest accretionary wedge - forearc basin systems in the world. It also exhibits a double forearc basin system with an interior basin (Cook inlet) and an outer basin, outboard of Kodiak Island, which is a prime candidate for a negative-alpha basin, as described by Fuller et al., (Geology, 2006). A number

Simulated and observed 2010 flood-water elevations in selected river reaches in the Moshassuck and Woonasquatucket River Basins, Rhode Island

Science.gov (United States)

Zarriello, Phillip J.; Straub, David E.; Westenbroek, Stephen M.

2014-01-01

Heavy persistent rains from late February through March 2010 caused severe flooding and set, or nearly set, peaks of record for streamflows and water levels at many long-term U.S. Geological Survey streamgages in Rhode Island. In response to this flood, hydraulic models were updated for selected reaches covering about 33 river miles in Moshassuck and Woonasquatucket River Basins from the most recent approved Federal Emergency Management Agency flood insurance study (FIS) to simulate water-surface elevations (WSEs) from specified flows and boundary conditions. Reaches modeled include the main stem of the Moshassuck River and its main tributary, the West River, and three tributaries to the West River—Upper Canada Brook, Lincoln Downs Brook, and East Branch West River; and the main stem of the Woonasquatucket River. All the hydraulic models were updated to Hydrologic Engineering Center-River Analysis System (HEC-RAS) version 4.1.0 and incorporate new field-survey data at structures, high-resolution land-surface elevation data, and flood flows from a related study. The models were used to simulate steady-state WSEs at the 1- and 2-percent annual exceedance probability (AEP) flows, which is the estimated AEP of the 2010 flood in the Moshassuck River Basin and the Woonasquatucket River, respectively. The simulated WSEs were compared to the high-water mark (HWM) elevation data obtained in these basins in a related study following the March–April 2010 flood, which included 18 HWMs along the Moshassuck River and 45 HWMs along the Woonasquatucket River. Differences between the 2010 HWMs and the simulated 2- and 1-percent AEP WSEs from the FISs and the updated models developed in this study varied along the reach. Most differences could be attributed to the magnitude of the 2- and 1-percent AEP flows used in the FIS and updated model flows. Overall, the updated model and the FIS WSEs were not appreciably different when compared to the observed 2010 HWMs along the

URBANIZATION AND ENVIRONMENTAL DISRUPTION OF CATCHMENT BASINS AS A RESULT OF HOUSING DEVELOPMENT AT CIDADE OPERARIA AND ADJACENCIES, MARANHAO ISLAND

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Izis Deise Silva de Sousa

2005-05-01

Full Text Available The Industrial Revolution was followed by an increase in the rates of urbanization, particularlyafter the second-half of the 20th century. In this context, Sao Luis, the capital city ofMaranhao State, adopted a housing development policy that was aimed at reducing thehousing deficit in the municipality. The construction of the Cidade Operaria housing complexwas a response to these explicit social needs, which have intensified since the 1970s. Theoccupation of the complex, however, resulted in considerable damage to the ecologicalintegrity of the adjacent habitats. The complex is located in the catchment basin of thePaciencia and Santo Antonio rivers, at the center of the Maranhao Island. This study analyzesthe spatial and temporal dynamics of the area’s urbanization process, which occurred in threephases: the period between 1976 and 1981 saw the removal of the original vegetation cover insome areas, as a result of the first settlement in Parque Zelandia. During that period,subsistence agriculture was common practice along the margins of streams and rivers. Thesecond phase corresponds to the construction of the Cidade Operaria housing complex, whichoccurred between 1981 and 1988. During that time, 860 ha of land were cleared andurbanized, resulting in considerable environmental damage. Changes of relief, due to gradingand earthmoving activities, lead to irreversible modifications in the course of rivers andstreams; many tributaries of the rivers Paciencia and Santo Antonio had theirs springssmothered by earthfills; construction of houses and the use of asphalt on roads reduced soilpermeability, increasing the depth of the water table; the release of untreated sewagecontaminated the drainage basins. During the third phase, which started in 1988, theenvironmental degradation was intensified by the occupation of areas adjacent to the housingcomplex. This model of urbanization has caused irreversible damage to the hydrology andwater quality in the

Remediation System Evaluation, Tutu Wellfield Superfund Site, St. Thomas, U.S. Virgin Islands

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The Tutu Wellfield Superfund Site is a 1.5 square mile site located on the eastern end of St. Thomas, U.S. Virgin Islands (USVI) within the upper Turpentine Run surface drainage basin in the Anna’s Retreat area.

Stratigraphic, regional unconformity analysis and potential petroleum plays of East Siberian Sea Basin

Science.gov (United States)

Karpov, Yury; Stoupakova, Antonina; Suslova, Anna; Agasheva, Mariia

2017-04-01

The East Siberian Sea basin (ESSB) one of the most unexplored part of the Russian Arctic shelf, extending for over 1000 km from New Siberian Islands archipelago to Wrangel Island. This region is considered as a region with probable high petroleum potential. Within the ESSB several phases of orogeny are recognized [1]: Elsmerian orogeny in Early Devonian, Early Brooks orogeny in Early Cretaceous, Late Brooks orogeny in Late Cretaceous. Two generations of the basins could be outlined. Both of these generations are controlled by the basement domains [1]: Paleozoic (post-Devonian) to Mesozoic basins preserved north of the Late Mesozoic frontal thrusts; Aptian-Albian to Quaternary basins, postdating the Verkhoyansk-Brookian orogeny, and evolving mainly over the New-Siberian-Chukchi Fold Belt. Basin is filled with siliclastic sediments and in the deepest depocentres sediments thickness exceeds 8-10 km in average. Seismic data was interpreted using methods of seismic stratigraphy. Finally, main seismic horizons were indicated and each horizon follows regional stratigraphic unconformities: mBU - in base of Cenozoic, BU - in base of Upper Cretaceous, LCU - in base of Cretaceous, JU - in middle of Jurassic, F - in top of Basement. In ESSB, we can identify Permian, Triassic, Jurassic, Cretaceous, Paleogene and Neogene seismic stratigraphy complexes. Perspective structures, investigated in ESSB were founded out by comparing seismogeological cross-sections with explored analogs in other onshore and offshore basins [2, 3, 4]. The majority of structures could be connected with stratigraphic and fault traps. The most perspective prospects are probably connected with grabens and depressions, where thickness of sediments exceed 10 km. Reservoirs in ESSB are proposed by regional geological explorations on New Siberian Islands Archipelago and Wrangel Island. Potential seals are predominantly assigned to Jurassic and Cretaceous periods. Thick clinoform units of various geometry and

Volcanism and Tectonics of the Central Deep Basin, Sea of Japan

Science.gov (United States)

Lelikov, E. P.; Emelyanova, T. A.; Pugachev, A. A.

2018-01-01

The paper presents the results of a study on the geomorphic structure, tectonic setting, and volcanism of the volcanoes and volcanic ridges in the deep Central Basin of the Sea of Japan. The ridges rise 500-600 m above the acoustic basement of the basin. These ridges were formed on fragments of thinned continental crust along deep faults submeridionally crossing the Central Basin and the adjacent continental part of the Primorye. The morphostructures of the basin began to submerge below sea level in the Middle Miocene and reached their contemporary positions in the Pliocene. Volcanism in the Central Basin occurred mostly in the Middle Miocene-Pliocene and formed marginal-sea basaltoids with OIB (ocean island basalt) geochemical signatures indicating the lower-mantle plume origin of these rocks. The OIB signatures of basaltoids tend to be expressed better in the eastern part of the Central Basin, where juvenile oceanic crust has developed. The genesis of this crust is probably related to rising and melting of the Pacific superplume apophyse.

Comment on: Geoarchaeological and chronometrical evidence of early human occupation on Lanzarote (Canary Islands), by Zöller et al.

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Carracedo, Juan-Carlos; Meco, Joaquín.; Lomoschitz, Alejandro; Antonia Perera, María.; Ballester, Javier; Betancort, Juan-Francisco

2004-10-01

In a recent paper Zöller et al. (2003) present their results of the stratigraphic, sedimentologic, soil mineralogy and IRSL dating of several soil beds filling a basin located near the village of Guatiza, at the eastern flank of the Famara shield, in the island of Lanzarote (Canary Islands). According to these authors, the soils correspond to a desert loess-palaeosol sequence with many coarse alluvial fan deposits, accumulated as scoria cones encircled the open ancient valley extending from SW to NE near Guatiza and their lava flowed to form the Vega de Guatiza endoreic basin. According to these authors, this depression served as a sediment trap from its formation.

Plastic pollution in islands of the Atlantic Ocean.

Science.gov (United States)

Monteiro, Raqueline C P; Ivar do Sul, Juliana A; Costa, Monica F

2018-07-01

Marine plastic pollution is present in all oceans, including remote oceanic islands. Despite the increasing number of articles on plastic pollution in the last years, there is still a lack of studies in islands, that are biodiversity hotspots when compared to the surrounding ocean, and even other recognized highly biodiverse marine environments. Articles published in the peer reviewed literature (N = 20) were analysed according to the presence of macro (>5 mm) and microplastics (plastics associated with variables such as position of the beach in relation to wind and currents. Very few studies have analysed plastics colonization by organisms or the identification of persistent organic pollutants (POPs). Islands of the North/South Atlantic and Caribbean Sea were influenced by different sources of macroplastics, being marine-based sources (i.e., fishing activities) predominant in the Atlantic Ocean basin. On the other hand, in the Caribbean Sea, land-based sources were more common. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantification of sediment export from two contrasted catchments of the Mayotte Island: a multi-scale observatory to fight against soil erosion and siltation of the lagoon in Mayotte Island

Science.gov (United States)

Landemaine, Valentin; Lidon, Bruno; Lopez, Jean-Marie; Dejean, Cyril; Bozza, Jean-Louis; Benard, Bhavani; Parizot, Manuel; Desprats, Jean-Francois; Cerdan, Olivier

2017-04-01

As a consequence of a dramatic increase of its population, the Mayotte Island is undergoing significant land use changes, mainly through an increase in agricultural areas as well as unplanned urban sprawl. Resulting soil erosion in natural degraded areas, in agricultural fields or from rural habitat threatens the sustainability of agriculture, as well as the balance of the lagoon ecosystem, one of the largest in the world, by siltation of the aquatic environment by sediments and adsorbed pollutants. In order to implement pertinent and sustainable remediation measure there is a need to quantify the sediment fluxes, identify the sources areas and raise awareness of population on land degradation. To this end, a multiscale hydro-sedimentary observatory was installed on two coastal watersheds representative of the morphology, geology and land use observed on the island of Mayotte: the Mtsamboro basin (19 ha) and the Dzoumogné basin (343 ha). On the Mtsamboro basin, rainfall, runoff and sediment monitoring is carried out by two stations in order to distinguish the urbanized downstream part (11 ha) from the upstream part under agro-forest cover (8 ha). A single hydro-sedimentary station was installed at the outlet of the Dzoumogné basin insofar land use is homogeneous and represented by agro-forest cover. The observatory is completed by a survey of runoff and erosion on experimental plots installed on the main types of land use of the island of Mayotte. The cumulative rainfall of this first year of monitoring is closed to the long term mean (1934-1997) with 1200 mm rained over the wet season (December - April). During this period, recorded rainfall events reached a maximum of 90 to 120 mm in 24 hours. The soil erosion rate over this year at the outlet of the Mtsamboro basin is 5.4 t.ha-1. On the upstream part of the watershed, the soil erosion rate decreases to about 1 t.ha-1, clearly lower than the tens of tons generally observed at the plot scale for this context

Genetic structure of lake whitefish, Coregonus clupeaformis, populations in the northern main basin of Lake Huron

Science.gov (United States)

Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Schaeffer, Jeff; Roseman, Edward F.; Harford, William J.; Johnson, James E.; Fietsch, Cherie-Lee

2012-01-01

Genetic analysis of spawning lake whitefish (Coregonus clupeaformis) from six sites in the main basin of Lake Huron was conducted to determine population structure. Samples from fisheryindependent assessment surveys in the northwest main basin were analyzed to determine the relative contributions of lake whitefish genetic populations. Genetic population structure was identified using data from seven microsatellite DNA loci. One population was identified at Manitoulin Island, one to two were observed in the east-central main basin (Fishing Island and Douglas Point), and one to two populations were found in the northwest (Thunder Bay and Duncan Bay). The genetic identity of collections from Duncan Bay and Thunder Bay was not consistent among methods used to analyze population structure. Low genetic distances suggested that they comprised one population, but genic differences indicated that they may constitute separate populations. Simulated data indicated that the genetic origins of samples from a mixed-fishery could be accurately identified, but accuracy could be improved by incorporating additional microsatellite loci. Mixture analysis and individual assignment tests performed on mixed-stock samples collected from the western main basin suggested that genetic populations from the east-central main basin contributed less than those from the western main basin and that the proportional contribution of each baseline population was similar in each assessment sample. Analysis of additional microsatellite DNA loci may be useful to help improve the precision of the estimates, thus increasing our ability to manage and protect this valuable resource.

Mapping Precipitation in the Lower Mekong River Basin and the U.S. Affiliated Pacific Islands

Science.gov (United States)

Lakshmi, V.; Sutton, J. R. P.; Bolten, J. D.

2017-12-01

Mapping and quantifying precipitation across varying temporal and spatial scales is of utmost importance in understanding, monitoring, and predicting flooding and drought. While there exists many in-situ precipitation gages that can accurately estimate precipitation in a given location, there are still many areas that lack in-situ gages. Many of these locations do not have precipitation gages because they are rural and/or topographically complex. The purpose of our research was to compare different remotely sensed satellite precipitation estimates with in-situ estimates across topographically complex and rural terrain within the United States Affiliated Pacific Islands (USAPI) and the Lower Mekong River Basin (LMRB). We utilize the publicly available Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) Climate Data Record (CDR) from NOAA and two remotely sensed precipitation products from NASA; the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM). These precipitation estimates were compared with each other and to the available in-situ precipitation estimates from station gages. We also utilize NASA Landsat data to determine the land cover types of these study areas. Using the precipitation estimates, topography, and the land cover of the study areas, we were able to show areas experiencing differing amounts of rainfall and their agreement with in-situ estimates. Additionally, we study the seasonal and spatial trends in precipitation. These analyses can be used to help understand areas that are experience frequent flood or drought.

The Minorca Basin: a buffer zone between the Valencia and Liguro-Provençal Basins (NW Mediterranean Sea)

Science.gov (United States)

Pellen, Romain; Aslanian, Daniel; Rabineau, Marina; Leroux, Estelle; Gorini, Christian; Silenziario, Carmine; Blanpied, Christian; Rubino, Jean-Loup

2017-04-01

The present-day compartmented Mediterranean physiography is inherited from the last 250 Ma kinematic plate evolution (Eurasian, Africa, Iberic and Nubia plates) which implied the formation of orogenic chains, polyphased basins, and morphological - geodynamic thresholds. The interactions between these entities are strongly debated in the North-Western Mediterranean area. Several Neogene reconstructions have been proposed for the Valencia basin depending of the basin segmentation where each model imply a different subsidence, sedimentary, and palaeo-environmental evolution. Our study propose a new kinematic model for the Valencia Basin (VB) that encompasses the sedimentary infill, vertical movement and basin segmentation. Detailed analyses of seismic profiles and boreholes in the VB reveal a differentiated basin, the Minorca Basin (MB), lying between the old Mesozoic Valencia Basin sensu strico (VBss) and the young Oligocene Liguro-Provencal Basin (LPB) (Pellen et al., 2016). The relationship between these basins is shown through the correlation of four Miocene-to-present-day megasequences. The Central and North Balearic Fracture Zones (CFZ and NBFZ) that border the MB represent two morphological and geodynamical thresholds that created an accommodation in steps between the three domains. Little to no horizontal Neogene movements have been found for the Ibiza and Majorca Islands and imply a vertical "sag" subsidence. In contrast, the counterclockwise movement of the Corso-Sardinian blocks induced a counterclockwise movement of the Minorca block towards the SE along the CFZ and NBFZ, during the exhumation of lower continental crust in the LPB. The South-Eastward Minorca block translation stops when the first atypical oceanic crust occurs. The influence of the Neogene Betic compressional phase is thus limited to the VBss on the basis of a different MB origin. This new understanding places the AlKaPeCa blocks northeastward of the present-day Alboran Area. Both NW-SE and

The demographic dynamics of small island societies.

Science.gov (United States)

Cruz, M; D'ayala, P G; Marcus, E; Mcelroy, J L; Rossi, O

1987-01-01

Small islands and microstates have demonstrated a unique demographic pattern, including cycles of swift population increases or decreases well beyond natural birth and death rate balances. These demographic fluctuations have been produced largely by rises or declines in market opportunities. The process of taking advantage of favorable opportunities is always followed by a specialization in the given activity, without regard to environmental protection issues or a longterm strategy for economic development and resource diversification. The population growth phase is associated with increasing fragility of the economic base, whether because of the external dangers of overspecialization or induced internal dysfunctions such as disease and resource depletion. Eventually complete collapse results, causing chronic outmigration or even depopulation. Case histories of maritime basins in the Mediterranean, Caribbean, and Pacific show that the demographic structure of small islands has been particularly sensitive to changing economic opportunities, the vagaries of market forces, and cataclysmic natural events. Experience in these areas suggests that balanced economic development of small islands should be based on diversification of activities, thus ensuring a relatively stable pattern of growth, sound environmental management, and control of dangerous demographic fluctuations. Special attention should be given to the development of broad-based research and cooperation to integrate specific island opportunities within a regional network.

Basement geology of Taranaki and Wanganui basins, New Zealand

International Nuclear Information System (INIS)

Mortimer, N.; Tulloch, A.J.; Ireland, T.R.

1997-01-01

We present a revised interpretation of the basement geology beneath Late Cretaceous to Cenozoic Taranaki and Wanganui basins of central New Zealand, based on new petrographic, geochemical, and geochronological data from 30 oil exploration wells. Recently published structural and magnetic interpretations of the area assist in the interpolation and extrapolation of geological boundaries. Torlesse and Waipapa terranes have been identified in Wanganui Basin, and Murihiku Terrane in eastern Taranaki Basin, but Maitai and Brook Street terrane rocks have not been recognised. Separation Point Suite, Karamea Suite, and Median Tectonic Zone igneous rocks are all identified on the basis of characteristic petrography, geochemistry, and/or age. SHRIMP U-Pb zircon measurements on igneous samples from western Taranaki wells do not give precise ages but do provide useful constraints: Motueka-1 granite is latest Devonian - earliest Carboniferous; Tangaroa-1 and Toropuihi-1 are Carboniferous; and Surville-1 is Cretaceous (cf. Separation Point Suite). Our interpretation of sub-basin geology is compatible with previously observed onland relationships in the North and South Islands. (author). 47 refs., 6 figs

High resolution bathymetric and sonar images of a ridge southeast of Terceira Island (Azores plateau)

Science.gov (United States)

Lourenço, N.; Miranda, J. M.; Luis, J.; Silva, I.; Goslin, J.; Ligi, M.

2003-04-01

The Terceira rift is a oblique ultra-slow spreading system where a transtensive regime results from differential movement between Eurasian and African plates. So far no classical ridge segmentation pattern has here been observed. The predominant morphological features are fault controlled rhombic shaped basins and volcanism related morphologies like circular seamounts and volcanic ridges. We present SIMRAD EM300 (bathymetry + backscatter) images acquired over one of these ridges located SE of Terceira Island, during the SIRENA cruise (PI J. Goslin), which complements previous TOBI mosaics performed over the same area during the AZZORRE99 cruise (PI M. Ligi). The ridge presents a NW-SE orientation, it is seismically active (a seismic crisis was documented in 1997) and corresponds to the southern branch of a V shape bathymetric feature enclosing the Terceira Island and which tip is located west of the Island near the 1998 Serreta ridge eruption site. NE of the ridge, the core of the V, corresponds to the North Hirondelle basin. All this area corresponds mainly to Brunhes magnetic epoch. The new bathymetry maps reveal a partition between tectonic processes, centred in the ridge, and volcanism present at the bottom of the North Hirondelle basin. The ridge high backscatter surface is cut by a set of sub-parallel anastomosed normal faults striking between N130º and N150º. Some faults present horse-tail terminations. Fault splays sometimes link to neighbour faults defining extensional duplexes and fault wedge basins and highs of rhombic shape. The faulting geometry suggests that a left-lateral strike slip component should be present. The top of the ridge consists on an arched demi-.horst, and it is probably a volcanic structure remnant (caldera system?), existing prior to onset of the tectonic stage in the ridge. Both ridge flanks display gullies and mass wasting fans at the base of the slope. The ridge vicinities are almost exclusively composed of a grayish homogeneous

Geodynamic implications for zonal and meridional isotopic patterns across the northern Lau and North Fiji Basins

Science.gov (United States)

Price, Allison A.; Jackson, Matthew G.; Blichert-Toft, Janne; Kurz, Mark D.; Gill, Jim; Blusztajn, Jerzy; Jenner, Frances; Brens, Raul; Arculus, Richard

2017-03-01

We present new Sr-Nd-Pb-Hf-He isotopic data for 65 volcanic samples from the northern Lau and North Fiji Basins. This includes 47 lavas obtained from 40 dredge sites spanning an east-west transect across the Lau and North Fiji basins, 10 ocean island basalt (OIB)-type lavas collected from seven Fijian islands, and eight OIB lavas sampled on Rotuma. For the first time, we are able to map clear north-south and east-west geochemical gradients in 87Sr/86Sr across the northern Lau and North Fiji Basins: lavas with the most geochemically enriched radiogenic isotopic signatures are located in the northeast Lau Basin, while signatures of geochemical enrichment are diminished to the south and west away from the Samoan hot spot. Based on these geochemical patterns and plate reconstructions of the region, these observations are best explained by the addition of Samoa, Rurutu, and Rarotonga hot spot material over the past 4 Ma. We suggest that underplated Samoan material has been advected into the Lau Basin over the past ˜4 Ma. As the slab migrated west (and toward the Samoan plume) via rollback over time, younger and hotter (and therefore less viscous) underplated Samoan plume material was entrained. Thus, entrainment efficiency of underplated plume material was enhanced, and Samoan plume signatures in the Lau Basin became stronger as the trench approached the Samoan hot spot. The addition of subducted volcanoes from the Cook-Austral Volcanic Lineament first from the Rarotonga hot spot, then followed by the Rurutu hot spot, contributes to the extreme geochemical signatures observed in the northeast Lau Basin.

Water table in Long Island, New York, March 1971

Science.gov (United States)

Koszalka, Edward J.; Koch, Ellis

1971-01-01

The geologic framework and the hydrologic situation in Long Island are periodically reviewed by the U.S. Geological Survey as new knowledge is obtained from current investigations. This work is done through cooperative programs with Nassau and Suffolk County agencies and the New York State Department of Environmental Conservation. A unique opportunity to update many of the hydrogeologic maps occurred when the Geological Survey's Mineola, N.Y., office participated in the New England River Basins Commission's "Long Island Sound Study." This map, one of a series of open-file maps showing the updated information, was compiled from data obtained from G. E. Kimmel (written commun., July 1972) and Jensen and Soren (in press). Comparison of the March 1971 data with similar data for March 1970 (Kimmel, 1970) shows virtually no change in water levels on Long Island during the 12 month period, except for a slight decline in levels in central Suffolk County.

Groundwater resources of Mosteiros basin, island of Fogo, Cape Verde, West Africa

Science.gov (United States)

Heilweil, Victor M.; Gingerich, Stephen B.; Plummer, Niel; Verstraeten, Ingrid M.

2010-01-01

Groundwater resources in Cape Verde provide water for agriculture, industry, and human consumption. These resources are limited and susceptible to contamination. Additional groundwater resources are needed for continued agricultural development, particularly during times of drought, but increased use and (or) climatic change may have adverse effects on the quantity and quality of freshwater available. In volcanic island aquifers such as those of Cape Verde, a lens of fresh groundwater typically ?floats? upon a layer of brackish water at the freshwater/saltwater boundary, and increased pumping may cause salt water intrusion or other contamination. A recent U.S. Geological Survey study assessed baseline groundwater conditions in watersheds on three islands of Cape Verde to provide the scientific basis for sustainably developing water resources and minimizing future groundwater depletion and contamination.

Insights on the evolution of mid-ocean basins: the Atlantis Basin of southern Azores

Science.gov (United States)

Alves, T.; Bouriak, S.; Volkonskaya, A.; Monteiro, J.; Ivanov, M.

2003-04-01

Single-channel seismic reflection and sidescan (OKEAN) data acquired in an unstudied region of the North Atlantic give important insights on the evolution of mid-ocean basins. Located on the eastern flank of the Mid-Atlantic Ridge, south of the Azores Islands, the study area contains more than 1,000 ms two-way travel-time of sediments with a similar seismic stratigraphy to that of ODP sites 950-952 in the Madeira Abyssal Plain. Processed thickness values correspond to a maximum thickness of about 1450 m and an average thickness of more than 500 m based on velocity data from ODP sites 950-952. The structure of the surveyed area and its location in relation to the Madeira Abyssal Plain and Mid-Atlantic Ridge indicate the existence, south of Azores, of two distinct sedimentary basins separated by major structural lineaments (Azores-Gibraltar and Atlantis Fracture Zones) and by seamount chains (Cruiser-Great Meteor Chain, Plato-Atlantis Chain). The basement of the sedimentary basins is irregular, showing multiple dome-shaped volcanic structures identical to those in the Norwegian-Greenland Sea and Madeira Abyssal Plain. However, half-graben/graben basement blocks predominate east of 30ºW underneath a moderately deformed overburden. The complex structure observed most likely reflects changes in the direction and velocity of ocean spreading plus variations in the regional thermal gradients induced by local hot spots. In parallel, some of the sub-surface structures identified next to basin-bounding Fracture Zones may have resulted from transtensional and transpressional tectonism.

Cryogenic formation of brine and sedimentary mirabilite in submergent coastal lake basins, Canadian Arctic

Science.gov (United States)

Grasby, Stephen E.; Rod Smith, I.; Bell, Trevor; Forbes, Donald L.

2013-06-01

Two informally named basins (Mirabilite Basins 1 and 2) along a submergent coastline on Banks Island, Canadian Arctic Archipelago, host up to 1 m-thick accumulations of mirabilite (Na2SO4·10H2O) underlying stratified water bodies with basal anoxic brines. Unlike isostatically uplifting coastlines that trap seawater in coastal basins, these basins formed from freshwater lakes that were transgressed by seawater. The depth of the sill that separates the basins from the sea is shallow (1.15 m), such that seasonal sea ice formation down to 1.6 m isolates the basins from open water exchange through the winter. Freezing of seawater excludes salts, generating dense brines that sink to the basin bottom. Progressive freezing increases salinity of residual brines to the point of mirabilite saturation, and as a result sedimentary deposits of mirabilite accumulate on the basin floors. Brine formation also leads to density stratification and bottom water anoxia. We propose a model whereby summer melt of the ice cover forms a temporary freshwater lens, and rather than mixing with the underlying brines, it is exchanged with seawater once the ice plug that separates the basins from the open sea melts. This permits progressive brine development and density stratification within the basins.

Formation of forearc basins by collision between seamounts and accretionary wedges: an example from the New Hebrides subduction zone

Science.gov (United States)

Collot, J.-Y.; Fisher, M.A.

1989-01-01

Seabeam data reveal two deep subcircular reentrants in the lower arc slope of the New Hebrides island arc that may illustrate two stages in the development of a novel type of forearc basin. The Malekula reentrant lies just south of the partly subducted Bougainville seamount. This proximity, as well as the similarity in morphology between the reentrant and an indentation in the lower arc slope off Japan, suggests that the Malekula reentrant formed by the collision of a seamount with the arc. An arcuate fold-thrust belt has formed across the mouth of the reentrant, forming the toe of a new accretionary wedge. The Efate reentrant may show the next stage in basin development. This reentrant lies landward of a lower-slope ridge that may have begun to form as an arcuate fold-thrust belt across the mouth of a reentrant. This belt may have grown by continued accretion at the toe of the wedge, by underplating beneath the reentrant, and by trapping of sediment shed from the island arc. These processes could result in a roughly circular forearc basin. Basins that may have formed by seamount collision lie within the accretionary wedge adjacent to the Aleutian trenches. -Authors

Uncertainty dimension and basin entropy in relativistic chaotic scattering

Science.gov (United States)

Bernal, Juan D.; Seoane, Jesús M.; Sanjuán, Miguel A. F.

2018-04-01

Chaotic scattering is an important topic in nonlinear dynamics and chaos with applications in several fields in physics and engineering. The study of this phenomenon in relativistic systems has received little attention as compared to the Newtonian case. Here we focus our work on the study of some relevant characteristics of the exit basin topology in the relativistic Hénon-Heiles system: the uncertainty dimension, the Wada property, and the basin entropy. Our main findings for the uncertainty dimension show two different behaviors insofar as we change the relativistic parameter β , in which a crossover behavior is uncovered. This crossover point is related with the disappearance of KAM islands in phase space, which happens for velocity values above the ultrarelativistic limit, v >0.1 c . This result is supported by numerical simulations and by qualitative analysis, which are in good agreement. On the other hand, the computation of the exit basins in the phase space suggests the existence of Wada basins for a range of β relevant in galactic dynamics, and it also has important implications in other topics in physics such as as in the Störmer problem, among others.

Kankakee River Basin: Evaluation of Sediment Management Strategies

Science.gov (United States)

2013-09-01

basin, and development of a SIAM model from an existing US Army Corps of Engineers Hydrologic Engineering Center, River Analysis System ( HEC - RAS ...4 SIAM Model A SIAM model was developed from an existing calibrated HEC - RAS model provided by the Rock Island District. The limits of the HEC - RAS ...model are shown in Figure 4.1. No further effort was made to verify the calibration of the HEC - RAS model. The estimated sediment loads were used to

Simulated and observed 2010 floodwater elevations in selected river reaches in the Pawtuxet River Basin, Rhode Island

Science.gov (United States)

Zarriello, Phillip J.; Olson, Scott A.; Flynn, Robert H.; Strauch, Kellan R.; Murphy, Elizabeth A.

2014-01-01

Heavy, persistent rains from late February through March 2010 caused severe flooding that set, or nearly set, peaks of record for streamflows and water levels at many long-term streamgages in Rhode Island. In response to this event, hydraulic models were updated for selected reaches covering about 56 river miles in the Pawtuxet River Basin to simulate water-surface elevations (WSEs) at specified flows and boundary conditions. Reaches modeled included the main stem of the Pawtuxet River, the North and South Branches of the Pawtuxet River, Pocasset River, Simmons Brook, Dry Brook, Meshanticut Brook, Furnace Hill Brook, Flat River, Quidneck Brook, and two unnamed tributaries referred to as South Branch Pawtuxet River Tributary A1 and Tributary A2. All the hydraulic models were updated to Hydrologic Engineering Center-River Analysis System (HEC-RAS) version 4.1.0 using steady-state simulations. Updates to the models included incorporation of new field-survey data at structures, high resolution land-surface elevation data, and updated flood flows from a related study. The models were assessed using high-water marks (HWMs) obtained in a related study following the March– April 2010 flood and the simulated water levels at the 0.2-percent annual exceedance probability (AEP), which is the estimated AEP of the 2010 flood in the basin. HWMs were obtained at 110 sites along the main stem of the Pawtuxet River, the North and South Branches of the Pawtuxet River, Pocasset River, Simmons Brook, Furnace Hill Brook, Flat River, and Quidneck Brook. Differences between the 2010 HWM elevations and the simulated 0.2-percent AEP WSEs from flood insurance studies (FISs) and the updated models developed in this study varied with most differences attributed to the magnitude of the 0.2-percent AEP flows. WSEs from the updated models generally are in closer agreement with the observed 2010 HWMs than with the FIS WSEs. The improved agreement of the updated simulated water elevations to

Obsidian hydration rate for the klamath basin of california and Oregon.

Science.gov (United States)

Johnson, L

1969-09-26

A hydration rate for obsidian of 3.5(4) microns squared per 1000 radio-carbon years has been established at the Nightfire Island archeological site in northern California and provides a means to date other prehistoric Klamath Basin sites. The new rate follows the form of the hydration equation formulated by Friedman and helps to refute claims made for other hydration equations.

Late Quaternary stratigraphy and depositional history of the Long Island Sound basin

Science.gov (United States)

Lewis, Ralph S.; Stone, Janet R.

1991-01-01

The stratigraphy of Late Quaternary geologic units beneath Long Island Sound (LIS) is interpreted from 3,500 km of high-resolution, seismic-reflection profiles supplemented by vibracore data. Knowledge gained from onshore regional geologic studies and previous offshore investigations is also incorporated in these interpretations.

Mesozoic and Cenozoic tectonics of the eastern and central Alaska Range: Progressive basin development and deformation in a suture zone

Science.gov (United States)

Ridgway, K.D.; Trop, J.M.; Nokleberg, W.J.; Davidson, C.M.; Eastham, K.R.

2002-01-01

Analysis of late Mesozoic and Cenozoic sedimentary basins, metamorphic rocks, and major faults in the eastern and central Alaska Range documents the progressive development of a suture zone that formed as a result of collision of an island-arc assemblage (the Wrangellia composite terrane) with the former North American continental margin. New basin-analysis, structural, and geochronologic data indicate the following stages in the development of the suture zone: (1) Deposition of 3-5 km of Upper Jurassic-Upper Cretaceous marine strata (the Kahiltna assemblage) recorded the initial collision of the island-arc assemblage with the continental margin. The Kahiltna assemblage exposed in the northern Talkeetna Mountains represents a Kimmeridgian-Valanginian backarc basin that was filled by northwestward-flowing submarine-fan systems that were transporting sediment derived from Mesozoic strata of the island-arc assemblage. The Kahiltna assemblage exposed in the southern Alaska Range represents a Valanginian-Cenomanian remnant ocean basin filled by west-southwestward-flowing submarine-fan systems that were transporting sediment derived from Paleozoic continental-margin strata uplifted in the along-strike suture zone. A belt of retrograde metamorphism and a regional anticlinorium developed along the continental margin from 115 to 106 Ma, roughly coeval with the end of widespread deposition in the Kahiltna sedimentary basins. (2) Metamorphism of submarine-fan deposits of the Kahiltna basin, located near the leading edge of the island-arc assemblage, occurred at ca. 74 Ma, as determined from a new U-Pb zircon age for a synkinematic sill. Coeval with metamorphism of deposits of the Kahiltna basin in the southern part of the suture zone was development of a thrust-top basin, the Cantwell basin, in the northern part of the suture zone. Geologic mapping and compositional data suggest that the 4 km of Upper Cretaceous nonmarine and marginal marine sedimentary strata in this basin

Effect of Nearshore Islands on Tsunami Inundation in Shadow Zones

Science.gov (United States)

Goertz, J.; Kaihatu, J. M.; Kalligeris, N.; Lynett, P. J.; Synolakis, C.

2017-12-01

Field surveys performed in the wake of the 2010 Mentawai tsunami event have described the belief of local residents that offshore islands serve as possible tsunami sheltering mechanisms, reducing the corresponding inundation on beaches behind the islands, despite the fact that deduced inundation from debris lines show this to be in fact untrue (Hill et al. 2012). Recent numerical model studies (Stefanakis et al. 2014) have shown that inundation levels on beaches behind conical islands are indeed higher than they are on open coastlines. While work has been done on tsunami amplification on the lee side of islands (Briggs et al. 1995), no work has been done concerning tsunami inundation on beach areas behind the islands. A series of experiments to address this were conducted in the Directional Wave Basin (DWB) at the O.H. Hinsdale Wave Research Laboratory at Oregon State University in summer 2016. A series of four sheet metal islands (two with a full conical section, two truncated at the water line) were placed at varying distances from the toe of a 1/10 sloping beach. Incident wave conditions consisting of solitary waves and full-stroke "dam break" waves were run over the islands. Free surface elevations, velocities, and beach runup were measured, with the intent of determining relationships between the wave condition, the island geometry and distance from the beach, and the tsunami characteristics. A series of runup measurements from a particular set of experiments can be seen in Figure 1. Based on these preliminary analyses, it was determined that: A) inundation was always amplified behind the island relative to areas outside this shadow zone; and B) inundation was generally highest with the island closest to the beach, except in the case where the tsunami wave broke prior to reaching the island. In this latter scenario, the inundation behind the island increased with island distance from the beach. The development of relationships between the inundation levels

Petroleum prospectivity of the onshore Gaspe and offshore Anticosti Basins, eastern Canada

International Nuclear Information System (INIS)

Durling, P.; Martel, T.; Waldron, J.W.F.

1998-01-01

The development of oil and gas reserves on the Scotian Shelf and the Grand Banks of Newfoundland has sparked a renewed interest in the onshore Gaspe-Connecticut Valley Synclinorium (GCVS) and the offshore Anticosti Basin. The geologic history of each basin was described and some of the geological relationships that suggest the presence of hydrocarbon resources in the area were reviewed. The Anticosti Basin developed in a rift and open marine shelf environment during the early Cambrian period. Petroleum exploration in the Basin began in the early 1960s when Imperial Oil collected 435 km of single channel seismic reflection data - enough to identify several drilling locations. Eight wells were drilled on the island which resulted in a number of shows of oil and gas. The GCVS was developed within the Appalachian Orogen and is comprised of fine grained siliciclastic turbidites. The structural geology of the GCVS is more complicated than the Anticosti Basin. Petroleum exploration in the GCVS has, for the most part, been in the eastern part of the Gaspe Peninsula where one producing well is located. The central part is mainly unexplored for petroleum resources

Sea floor morphology of the Ebro Shelf in the region of the Columbretes Islands, Western Mediterranean

Science.gov (United States)

Muñoz, A.; Lastras, G.; Ballesteros, M.; Canals, M.; Acosta, J.; Uchupi, E.

2005-12-01

Widespread volcanism off eastern Spain in the western Mediterranean is associated with Cenozoic crustal attenuation and sinistral motion along the Trans-Moroccan-Western Mediterranean-European mega shear, extending from northern Morocco to the North Sea via the Alboran Basin, eastern Iberia, the Valencian and Lyons basins, France and Germany. The Quaternary Columbretes Islands volcanic field is the most prominent example of this volcanism associated with this mega shear. The islands are located in the Ebro continental shelf on top of a structural horst probably made of Paleozoic metamorphic rocks. Surrounding the emerged islands are volcanic structures and associated flows partially mantled by a sediment drift whose morphology is controlled by the southwestward flowing Catalan Current. This association is rather unique and appears to have never been described from a continental shelf in the Mediterranean Sea or outside the sea. The morphology of both kinds of structures, obtained by means of swath bathymetry data and very-high resolution seismic profiles, is presented in this study. They provide striking images of this previously unstudied part of the western Mediterranean seafloor. These images suggest that the volcanic structures are intruded into the surficial Holocene sediments indicating that volcanism in the Columbretes has extended into Holocene.

Postglacial Records of Southern Hemisphere Westerly Wind Variability From the New Zealand Subantarctic Auckland Islands

Science.gov (United States)

Moy, C. M.; Vandergoes, M.; Gilmer, G. J.; Nichols, J. E.; Dagg, B. J.; Wilson, G. S.; Browne, I. M.; Curtin, L. G.; Aebig, C.; McGlone, M.

2015-12-01

The strength and latitudinal position of the Southern Hemisphere westerly winds (SHWW) play a fundamental role in influencing mid latitude climate and carbon dioxide exchange between the Southern Ocean and the atmosphere. Despite their importance, our understanding of past changes in the SHWW is limited by few paleoclimate records from the modern wind maximum that are often not in agreement. The New Zealand subantarctic Auckland Islands are located within the core of the modern wind belt (50°S) where the ocean-atmospheric linkages between the Antarctic and middle latitudes are strong. In contrast to other subantarctic islands on the Campbell Plateau, the Auckland Islands have protected fjord sub-basins, deep lakes, and peatlands that are advantageous for the development of high-resolution paleoclimate records. We will present ongoing work towards the establishment of multi-proxy and multi-site reconstructions of past SHWW variability from the Auckland Islands. Modern process and paleoclimate results from two research cruises in 2014 and 2015 suggest that in lacustrine and fjord settings, the degree of water column mixing, the stable isotopic composition of n-alkanes and benthic foraminifera, the influx of terrestrial organic matter are good indicators of wind-induced mixing of the water column or precipitation-driven erosion within catchments. In ombrotrophic peatlands, hydrogen isotope ratios of specific organic molecules allow reconstructions of the hydrogen isotope ratios of precipitation, which is related to precipitation source area and the latitudinal position of the SHWW. Using macrofossil counts paired with abundances of leaf wax biomarkers, we are able to estimate the moisture balance at peatland coring sites. Early results indicate an overall strengthening of the SHWW at the Auckland Islands through the Holocene. We will discuss these results within the context of complimentary records developed from New Zealand and southern South America to ultimately

Archaeoastronomy and sacred places in Tenerife (Canary Islands).

Science.gov (United States)

Jiménez, J. J.; Esteban, C.; Febles, J. V.; Belmonte, J. A.

For the last few years the authors have been investigating (with work still in progress) several archaeological sites of the indigenous culture of the island of Tenerife, in search of possible astronomical connections, be these of a calendric or religious nature. Of these sites, the authors will concentrate, within their archaeological context, on those containing small channels and carved "basins" (or "hollows") and interpreted as probable cultic sites. The present work constitutes and initial approach to the contrasting of different aspects, such as location, celestial horizon, morphology, the visibility of Mount Teide and burials.

Petroleum system of Northwest Java basin based on gravity data analysis

Science.gov (United States)

Widianto, E.

2018-01-01

Energy management in the upstream oil and gas sector becomes very important for the country’s energy security. The renewal of energy resources and reserves becomes necessary and is a must. In the oil and gas industry, gravity data is usually used only for regional surveys, but with the development of instrumentation technology and gravity software development, this method can be used for assessing oil and gas survey stages from exploration to production. This study was conducted to evaluate aspects of petroleum system and exploration play concept in the part of Northwest Java Basin, covering source rock deposition regions (source kitchen area, migration direction), development of reservoirs, structural and stratigraphic trap, based on gravity data. This study uses data from Bouguer gravity anomaly map by filtering process to produce a residual map depicting sedimentation basin configuration. The mapping generated 20 sedimentary basins in Java Island with the total hydrocarbon resources of 113 BBOE (Billion Barrel of Oil Equivalent). The petroleum system analysis was conducted in the Northwest Basin section. The final map produced illustrates the condition of petroleum system and play concept that can be used as exploration direction, expectedly reducing the risk of drilling failure.

The relationship between the seismic characteristics of crustal structure in Shikoku Basin and en-echelon arrangement

Science.gov (United States)

Yamashita, M.; Takahashi, N.; Kodaira, S.; No, T.; Takizawa, K.; Miura, S.; Kaiho, Y.; Sato, T.; Kaneda, Y.

2007-12-01

Detailed crustal structure information of a back-arc basin must be obtained to elucidate the mechanism of its opening. Especially, the Shikoku Basin, which occupies the northern part of the Philippine Sea Plate between the Kyushu-Palau Ridge and the Izu-Ogasawara Arc, is an important area to elucidate the evolution of the back-arc basins as a part of the growth process of the Philippine Sea. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) carried out multi-channel seismic reflection survey using 12,000 cu.in. air gun and streamer with 204 ch hydrophones in the Izu-Ogasawara region since 2004. The total length of survey lines is more than 10,000 km until 2006. We investigate the crustal structure beneath the Shikoku Basin along 10 survey lines, which are across to the strike of the en-echelon seamount chains in the rear arc. From the seismic profiles, some faults and intrusion structures are obtained in the Shikoku Basin. The deformation structure with acoustic basement is widely distributed between the Shikoku Basin and the Izu-Ogasawara arc. Some intrusions structure is identified in the Shikoku Basin are exposed on seafloor. The intrusions structure is assumed to locate in the extended region of the en-echelon arrangement. The strike-slip faults with flower structure cutting whole sediments are located in the arc-backarc transition zone in the northern Shikoku Basin, suggesting that this region is in share stress. On the other hand, these structures indicating the deformation and intrusions are not recognized in the eastern side of the Kyushu-Palau Ridge. The Izu-Ogasawara arc is colliding to the Japan Island arc in the Sagami Bay. In the Nankai Trough, the Philippine Sea plate is subducting to the Japan Island arc. Therefore, the strike-slip and reverse fault would be developed by the compression stress in the eastern side of Philippine Sea plate. If the en-echelon arrangement is developed along these faults, the intrusions structure obtained by

Mesozoic and Cenozoic tectonics of the eastern and central Alaska Range: Progressive basin development and deformation in a suture zone

Energy Technology Data Exchange (ETDEWEB)

Ridgway, K.D.; Trop, J.M.; Nokleberg, W.J.; Davidson, C.M.; Eastham, K.R. [Purdue University, W. Lafayette, IN (United States). Dept. of Earth & Atmospheric Science

2002-07-01

Analysis of late Mesozoic and Cenozoic sedimentary basins, metamorphic rocks, and major faults in the eastern and central Alaska Range documents the progressive development of a suture zone that formed as a result of collision of an island-arc assemblage (the Wrangellia composite terrane) with the former North American continental margin. New basin-analysis, structural, and geochronologic data indicate the following stages in the development of the suture zone: (1) Deposition of 3-5 km of Upper Jurassic-Upper Cretaceous marine strata (the Kahiltna assemblage) recorded the initial collision of the island-arc assemblage with the continental margin. (2) Metamorphism of submarine-fan deposits of the Kahiltna basin, located near the leading edge of the island-arc assemblage, occurred at ca. 74 Ma, as determined from a new U-Pb zircon age for a synkinematic sill. (3) Shortening and exhumation of the suture zone peaked from 65 to 60 Ma on the basis of metamorphic and geochronologic data. (4) From 60 to 54 Ma, about 3 km of volcanic strata were deposited over deformed sedimentary strata of the Cantwell basin, and several granitic plutons (the McKinley sequence) were emplaced along the suture zone. (5) Following igneous activity, strike-slip displacement occurred from ca. 54 to 24 Ma along the Denali fault system, which had developed in the existing suture zone. (6) Regional transpressive shortening characterized the suture zone from ca. 24 Ma to the present. Regional subsidence resulted in Miocene coal seams up to 20 m thick and well-developed lacustrine deposits. Overlying the Miocene deposits are about 1.2 km of Pliocene and Holocene conglomeratic deposits. These mapping relationships provide evidence that regional shortening continues to the present in the eastern and central Alaska Range.

Uplifting of the Jiamusi Block in the eastern Central Asian Orogenic Belt, NE China: evidence from basin provenance and geochronology

Science.gov (United States)

Liu, Yongjiang; Wen, Quanbo; Han, Guoqing; Li, Wei

2010-05-01

the Paleo-Asian Ocean the Jiamusi Block underwent a very rapid exhumation in the late Permian. In the early Mesozoic the area went into a basin developing stage and formed a large basin as a whole during the Early Cretaceous. In the Late Cretaceous the Jiamusi Block started uplifting and the basin was broken into isolate small basins. References: Bureau of Geology and Mineral Resources of Heilongjiang Province. Regional geology of Heilongjiang Province. Beijing: Geological Publishing House, 1993.578-581. Cao Chengrun, Zheng Qingdao. Structural evolution feature and its significance of hydrocarbon exploration in relict basin formation, Eastern Heilongjiang province. Journal of Jilin university (Earth Science Edition), 2003, 33(2):167-172. Lang Xiansheng. Biologic Assemblage features of Coal-bearing Strata in Shuangyashan-Jixian coal-field. Coal geology of China, 2002, 14(2):7-12. Piao Taiyuan , Cai Huawei , Jiang Baoyu. On the Cretaceous coal-bearing Strata in Eastern Heilongjiang. Journal Of Stratigraphy, 2005, 29:489-496. Wang Jie , He Zhonghua , Liu Zhaojun , Du Jiangfeng , Wang Weitao. Geochemical characteristics of Cretaceous detrital rocks and their constraint on provenance in Jixi Basin. Global Geology，2006, 25(4):341-348. DickinsonW R and Christopher A. Suczek. Plate Tectonics and Sandstone Composition. AAPG B. 1979,63(12 ):2164-2182. DickinsonW R, Beard L S, Brakenridge G R, et al. Provenance of North American Phanerozoic sandstones in relation to tectonic setting. Bull Geo-Soc Amer, 1983, 94: 222-235. Maruyama S, Seno T. Orogeny and relative plate motions: Example of the Japanese Islands. Tectonophysics, 1986，127(3-4):305-329. Maruyama S, Isozaki Y, Kimura Gand Terabayashi M C.Paleogeographic maps of the Japanese Islands: plate tectonic systhesis from 750 Ma to the present. Island Arc, 1997,6:121-142.

Holocene closure of Lib Pond, Marshall Islands.

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Conor L Myhrvold

Full Text Available Well-preserved sediment from closed water bodies of atolls such as Lib Pond are rare opportunities to reconstruct the past regional climate, which pieced together across a latitude and longitude range identify the range of movement patterns of wider scale climate phenomena such as the Intertropical Convergence Zone (ITCZ and El Niño Southern Oscillation (ENSO. We conducted the first physico-chemical survey of Lib Pond, a shallow, closed-water saline lake located on remote and difficult to access Lib Island in the Marshall Islands at 8° 18' 48.99″ N, 167 22' 51.90″ E in the Pacific Ocean, in July 2009. We performed a bathymetric survey, recorded salinity, dissolved oxygen, pH, and temperature profiles, monitored the tidal variability, and conducted a vegetation survey surrounding the lake. From bathymetric data we calculated the lake volume, which we used to estimate the lake's salt budget, and ultimately the residence time of water in the lake basin. We took a series of sediment cores from the lake, cores which indicate Lib Island's changing environment and climate. Radiocarbon measurements determined sediment age, and reveal significant mixing over the last 2 ka of deposition. We conclude that prior to 3 ka, Lib Island was an atoll with a central lagoon connected to the open ocean, which was then closed off from the open ocean to form the brackish system that exists today. We predict that the sediment accumulation in Lib Pond evident today will continue. As seawater is inhibited from exchanging with fresh water, Lib Pond will become a shallower lake with increasingly fresh water.

Holocene closure of Lib Pond, Marshall Islands.

Science.gov (United States)

Myhrvold, Conor L; Janny, Fran; Nelson, Daniel; Ladd, S Nemiah; Atwood, Alyssa; Sachs, Julian P

2014-01-01

Well-preserved sediment from closed water bodies of atolls such as Lib Pond are rare opportunities to reconstruct the past regional climate, which pieced together across a latitude and longitude range identify the range of movement patterns of wider scale climate phenomena such as the Intertropical Convergence Zone (ITCZ) and El Niño Southern Oscillation (ENSO). We conducted the first physico-chemical survey of Lib Pond, a shallow, closed-water saline lake located on remote and difficult to access Lib Island in the Marshall Islands at 8° 18' 48.99″ N, 167 22' 51.90″ E in the Pacific Ocean, in July 2009. We performed a bathymetric survey, recorded salinity, dissolved oxygen, pH, and temperature profiles, monitored the tidal variability, and conducted a vegetation survey surrounding the lake. From bathymetric data we calculated the lake volume, which we used to estimate the lake's salt budget, and ultimately the residence time of water in the lake basin. We took a series of sediment cores from the lake, cores which indicate Lib Island's changing environment and climate. Radiocarbon measurements determined sediment age, and reveal significant mixing over the last 2 ka of deposition. We conclude that prior to 3 ka, Lib Island was an atoll with a central lagoon connected to the open ocean, which was then closed off from the open ocean to form the brackish system that exists today. We predict that the sediment accumulation in Lib Pond evident today will continue. As seawater is inhibited from exchanging with fresh water, Lib Pond will become a shallower lake with increasingly fresh water.

Geologic map of Saint Lawrence Island, Alaska

Science.gov (United States)

Patton, William W.; Wilson, Frederic H.; Taylor, Theresa A.

2011-01-01

Saint Lawrence Island is located in the northern Bering Sea, 190 km southwest of the tip of the Seward Peninsula, Alaska, and 75 km southeast of the Chukotsk Peninsula, Russia (see index map, map sheet). It lies on a broad, shallow-water continental shelf that extends from western Alaska to northeastern Russia. The island is situated on a northwest-trending structural uplift exposing rocks as old as Paleozoic above sea level. The submerged shelf between the Seward Peninsula and Saint Lawrence Island is covered mainly with Cenozoic deposits (Dundo and Egiazarov, 1982). Northeast of the island, the shelf is underlain by a large structural depression, the Norton Basin, which contains as much as 6.5 km of Cenozoic strata (Grim and McManus, 1970; Fisher and others, 1982). Sparse test-well data indicate that the Cenozoic strata are underlain by Paleozoic and Proterozoic rocks, similar to those exposed on the Seward Peninsula (Turner and others, 1983). Saint Lawrence Island is 160 km long in an east-west direction and from 15 km to 55 km wide in a north-south direction. The east end of the island consists largely of a wave-cut platform, which has been elevated as much as 30 m above sea level. Isolated upland areas composed largely of granitic plutons rise as much as 550 m above the wave-cut platform. The central part of the island is dominated by the Kookooligit Mountains, a large Quaternary shield volcano that extends over an area of 850 km2 and rises to an elevation of 630 m. The west end of the island is composed of the Poovoot Range, a group of barren, rubble-covered hills as high as 450 m that extend from Boxer Bay on the southwest coast to Taphook Mountain on the north coast. The Poovoot Range is flanked on the southeast by the Putgut Plateau, a nearly flat, lake-dotted plain that stands 30?60 m above sea level. The west end of the island is marked by uplands underlain by the Sevuokuk pluton (unit Kg), a long narrow granite body that extends from Gambell on the

Geology and assessment of undiscovered oil and gas resources of the Hope Basin Province, 2008

Science.gov (United States)

Bird, Kenneth J.; Houseknecht, David W.; Pitman, Janet K.; Moore, Thomas E.; Gautier, Donald L.

2018-01-04

The Hope Basin, an independent petroleum province that lies mostly offshore in the southern Chukchi Sea north of the Chukotka and Seward Peninsulas and south of Wrangel Island, the Herald Arch, and the Lisburne Peninsula, is the largest in a series of postorogenic (successor) basins in the East Siberian-Chukchi Sea region and the only one with exploratory-well control and extensive seismic coverage.In spite of the seismic coverage and well data, the petroleum potential of the Hope Basin Province is poorly known. The adequacy of hydrocarbon charge, in combination with uncertainties in source-rock potential and maturation, was the greatest risk in this assessment. A single assessment unit was defined and assessed, resulting in mean estimates of undiscovered, technically recoverable resources that include ~3 million barrels of oil and 650 billion cubic feet of nonassociated gas.

Interconnectedness during high water maintains similarity in fish assemblages of island floodplain lakes in the Amazonian Basin

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Carlos Edwar de C. Freitas

2010-01-01

Full Text Available We conducted a study to test the hypothesis that interconnectedness among island floodplain lakes and the adjacent Solimões River during the flood stage of the hydrologic cycle is enough to maintain similarity in fish species assemblages. Gill net samples were collected during high and low water periods for three consecutive years (July 2004 to July 2006 in four lakes on Paciência Island. Two lakes, Piranha and Ressaca, are connected to the river all year, and the other two, Preto and Cacau, which are in the center of the island, are isolated during low water periods. The abundance, species richness and evenness of the fish assemblages in these lakes did not differ according to their relative positions or the season of the hydrological cycle, which confirmed our hypothesis. However, fish abundance during the dry season was greater than in the flood season. Apparently, the short period of full connection between the lakes is enough to allow the colonization of all fish species, but not to cause similar abundances. Our study indicates that persistence of the species composition of island floodplain lakes is primarily due to the annual replenishment of fish to the lakes during the flood season.

Crustal architecture of the eastern margin of Japan Sea: back-arc basin opening and contraction

Science.gov (United States)

No, T.; Sato, T.; Takahashi, N.; Kodaira, S.; Kaneda, Y.; Ishiyama, T.; Sato, H.

2012-12-01

Although large earthquakes such as the 1964 Niigata earthquake (M 7.5), 1983 Nihonkai-Chubu earthquake (M 7.8), and 1993 Hokkaido Nansei-Oki earthquake (M 7.8) have caused large amounts of damage to the eastern margin of the Japan Sea, a substantial number of seismic studies have been conducted for the seismogenic zone on the Pacific Ocean side of Japan. In addition, the detail of the source fault model for the eastern margin of the Japan Sea is not well defined for all cases. This highlights the need for further studies to investigate seismic imaging. Therefore, we have collaborated with other Japanese research institutions for a project titled "Priority Investigations of Strain Concentration Areas" (which is funded by Special Coordination Funds for Promoting Science and Technology, Japan). This project has conducted seismic surveys from 2009 to 2012 using the deep-sea research vessel, Kairei, from the Japan Agency for Marine-Earth Science and Technology. There is a strain concentration area in the eastern part of the survey area (Okamura et al., 1995). The western part of the survey area includes the Yamato Basin and Japan Basin. It is very important to study the crustal structure in the seismotectonic studies of the eastern margin of the Japan Sea. We conducted a marine seismic survey by using a multichannel seismic (MCS) system and ocean bottom seismographs (OBSs) along the eastern margin of the Japan Sea. Seismic data were acquired along 42 lines with a total length of approximately 9,000 km. The following results were obtained from seismic imaging. On the basis of the results of the MCS imaging, active reverse faults and folds were observed in the margin of the Toyama Trough; however, the sedimentary layers in the trough were flat. In the sedimentary layers and crusts of the Sado Ridge, Mogami Trough, and source area of the 1964 Niigata earthquake located north of the Sado Island, greater deformation was observed. The deformation weakened toward the Yamato

Introduction - The impacts of the 2008 eruption of Kasatochi Volcano on terrestrial and marine ecosystems in the Aleutian Islands, Alaska

Science.gov (United States)

DeGange, Anthony R.; Byrd, G. Vernon; Walker, Lawrence R.; Waythomas, C.F.

2010-01-01

The Aleutian Islands are situated on the northern edge of the so-called “Pacific Ring of Fire,” a 40,000-km-long horseshoe-shaped assemblage of continental landmasses and islands bordering the Pacific Ocean basin that contains many of the world's active and dormant volcanoes. Schaefer et al. (2009) listed 27 historically active volcanoes in the Aleutian Islands, of which nine have had at least one major eruptive event since 1990. Volcanic eruptions are often significant natural disturbances, and ecosystem responses to volcanic eruptions may vary markedly with eruption style (effusive versus explosive), frequency, and magnitude of the eruption as well as isolation of the disturbed sites from potential colonizing organisms (del Moral and Grishin, 1999). Despite the relatively high frequency of volcanic activity in the Aleutians, the response of island ecosystems to volcanic disturbances is largely unstudied because of the region's isolation. The only ecological studies in the region that address the effects of volcanic activity were done on Bogoslof Island, a remote, highly active volcanic island in the eastern Aleutians, which grew from a submarine eruption in 1796 (Merriam, 1910; Byrd et al., 1980; Byrd and Williams, 1994). Nevertheless, in the 214 years of Bogoslof's existence, the island has been visited only intermittently.Kasatochi Island is a small (2.9 km by 2.6 km, 314 m high) volcano in the central Aleutian Islands of Alaska (52.17°N latitude, 175.51°W longitude; Fig. 1) that erupted violently on 7-8 August 2008 after a brief, but intense period of precursory seismic activity (Scott et al., 2010 [this issue]; Waythomas et al., in review). The island is part of the Aleutian arc volcanic front, and is an isolated singular island. Although the immediate offshore areas are relatively shallow (20–50 m water depth), the island is about 10 km south of the 2000 m isobath, north of which, ocean depths increase markedly. Kasatochi is located between the

Lead isotopic compositions of South Sandwich Island volcanic rocks and their bearing on magmagenesis in intra-oceanic island arcs

International Nuclear Information System (INIS)

Barreiro, B.

1983-01-01

Pb isotope ratios have been measured in 12 volcanic rocks from the South Sandwich Islands. The results are reported. In 207 Pb/ 204 Pb- 206 Pb/ 204 Pb and 208 Pb/ 204 Pb- 206 Pb/ 204 Pb correlation diagrams, the South Sandwich data plot distinctly above the fields for ocean ridge basalts, and yield trends showing apparent mixing with a sedimentary end member similar to South Atlantic pelagic sediments as reported by Chow and Patterson (1962) and this study. Armstrong and Cooper (1971) have likewise shown that volcanics from the Lesser Antilles show mixing trends with North Atlantic sediments in Pb isotope correlation diagrams. The North Atlantic sediments have distinctly higher 206 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios compared to the South Atlantic sediments. The parallel relationships between sediments and volcanic island arc rocks of the North and South Atlantic provide strong evidence for a component of Pb from subducted sediments in the lavas of the west Atlantic basin. In contrast to these data, lavas from the Mariana Arc in the western Pacific show little or no component of Pb from pelagic sediments. The reason for the different behaviors in the two settings is speculative. (author)

Evidence for slow late-glacial ice retreat in the upper Rangitata Valley, South Island, New Zealand

Science.gov (United States)

Shulmeister, J.; Fink, D.; Winkler, S.; Thackray, G. D.; Borsellino, R.; Hemmingsen, M.; Rittenour, T. M.

2018-04-01

A suite of cosmogenic radionuclide ages taken from boulders on lateral and latero-terminal moraines in the Rangitata Valley, eastern South Island, New Zealand demonstrates that relatively thick ice occupied valley reaches inland of the Rangitata Gorge until c. 21 ka. Thereafter ice began to thin, and by c. 17 ka it had retreated 33 km up-valley of the Rangitata Gorge to the Butler-Brabazon Downs, a structurally created basin in the upper Rangitata Valley. Despite its magnitude, this retreat represents a minor ice volume reduction from 21 ka to 17 ka, and numerous lateral moraines preserved suggest a relatively gradual retreat over that 4 ka period. In contrast to records from adjacent valleys, there is no evidence for an ice-collapse at c. 18 ka. We argue that the Rangitata record constitutes a more direct record of glacial response to deglacial climate than other records where glacial dynamics were influenced by proglacial lake development, such as the Rakaia Valley to the North and the major valleys in the Mackenzie Basin to the south-west. Our data supports the concept of a gradual warming during the early deglaciation in the South Island New Zealand.

Heat Islands

Science.gov (United States)

EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

Water exchange estimates derived from forcing for the hydraulically coupled basins surrounding Aespoe island and adjacent coastal water

International Nuclear Information System (INIS)

Engqvist, A.

1997-08-01

A numerical model study based on representative physical forcing data (statistically averaged from approximately 10 years) has been performed of the Aespoe area, subdivided into five separate basins, interconnected by four straits and connected to the Baltic coast through three straits. The water exchange of the shallow Borholmsfjaerden, with comparatively small section areas of its straits, is dominated by the sea level variations while the baroclinic exchange components (estuarine and intermediary circulation) also contribute. The average transit retention time (averaged over the basin volume for a full year cycle) is found to be a little over 40 days for exogenous water (i.e. coastal water and freshwater combined); this measure of the water exchange is comparable to the combined average of an ensemble consisting of 157 similarly analyzed basins distributed along the Swedish east and west coasts. The exchange mechanisms and model assumptions are discussed. The consequences for the retention times by short- and long-term variations of the forcing is also analyzed. The standard deviation (SD) of the retention time during an average year (intra-annual variation) is greater than the SD between years (interannual variation) for all basins except Borholmsfjaerden for which these two measures are in parity. The range of the retention times that results from an extreme combination of forcing factor variation between years is found to be greater the farther a particular basin is located from the coast, measured as the minimal number of separating straits. The results of an earlier investigation are also reviewed

Island biogeography

DEFF Research Database (Denmark)

Whittaker, Robert James; Fernández-Palacios, José María; Matthews, Thomas J.

2017-01-01

Islands provide classic model biological systems. We review how growing appreciation of geoenvironmental dynamics of marine islands has led to advances in island biogeographic theory accommodating both evolutionary and ecological phenomena. Recognition of distinct island geodynamics permits gener...

Tohoku-Oki Earthquake Tsunami Runup and Inundation Data for Sites Around the Island of Hawaiʻi

Science.gov (United States)

Trusdell, Frank A.; Chadderton, Amy; Hinchliffe, Graham; Hara, Andrew; Patenge, Brent; Weber, Tom

2012-01-01

At 0546 U.t.c. March 11, 2011, a Mw 9.0 ("great") earthquake occurred near the northeast coast of Honshu Island, Japan, generating a large tsunami that devastated the east coast of Japan and impacted many far-flung coastal sites around the Pacific Basin. After the earthquake, the Pacific Tsunami Warning Center issued a tsunami alert for the State of Hawaii, followed by a tsunami-warning notice from the local State Civil Defense on March 10, 2011 (Japan is 19 hours ahead of Hawaii). After the waves passed the islands, U.S. Geological Survey (USGS) scientists from the Hawaiian Volcano Observatory (HVO) measured inundation (maximum inland distance of flooding), runup (elevation at maximum extent of inundation) and took photographs in coastal areas around the Island of Hawaiʻi. Although the damage in West Hawaiʻi is well documented, HVO's mapping revealed that East Hawaiʻi coastlines were also impacted by the tsunami. The intent of this report is to provide runup and inundation data for sites around the Island of Hawaiʻi.

SUBMARINE MASS MOVEMENT AND LOCALIZED TSUNAMI POTENTIALITY OF MENTAWAI BASIN, SUMATERA, INDONESIA

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Haryadi Permana

2017-07-01

Full Text Available The new bathymetry and seismic data were acquired during the PreTI-Gap marine survey (February 15 to March 6, 2008. The survey was carried out along the NE margin of Mentawai Island using multi-beam swath bathymetry equipment, and 28-channels seismic streamer and four-airgun source. The first target was the Mega Island region near the epicenter of the 2007 great earthquake. The shallow bathymetry is characterized as a flat coral platform suggesting that 200 km elongated plateau is slowly subsiding without any active faults. Further north, from South Pagai to North of Siberut Islands, the seafloor morphology changes significantly. The deep and wide canyons or valleys produce very rough seafloor morphology between 50 and 1100 m water depth. In general, the submarine topography shows two break slopes at different depths. Between slope breaks, the undulating, hilly and circular features dominate, possibly caused by mass movement. A push-up ridge is observed that dams the sediments eroded within a steep slope northeastward side. The seismic reflection data acquired along 14 dip seismic lines at the NE flank of Mentawai Islands, from Siberut to the South of Pagai Islands. We observed a set of southwestward dipping back thrust bounding the NE margin of the Mentawai Island and the push-up ridge observed on bathymetric image, which suggest that Mentawai fault is not pure a strike slip fault, but consists of a set of back thrusts. Such kind of back thrust movement at the flank of Mentawai basin can trigger mass movement or landslide that can produce localized tsunami causing damages to Sumatera mainland such as Padang, Painan or northern Bengkulu provinces and Mentawai Islands. Therefore, it is important to re-design the tsunami warning system, especially in this region, in order to mitigate tsunami risk to coastal region of western Sumatera.

Tenarife Island, Canary Island Archipelago, Atlantic Ocean

Science.gov (United States)

1991-01-01

Tenarife Island is one of the most volcanically active of the Canary Island archipelago, Atlantic Ocean, just off the NW coast of Africa, (28.5N, 16.5W). The old central caldera, nearly filled in by successive volcanic activity culminating in two stratocones. From those two peaks, a line of smaller cinder cones extend to the point of the island. Extensive gullies dissect the west side of the island and some forests still remain on the east side.

The lived experience of Pacific Island women with a “big body” size

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Nafanua Braginsky

2016-03-01

Full Text Available This phenomenological study explored the lived experience with "big body" size of Pacific Island women who migrated to Hawaii. Giorgi’s descriptive phenomenological approach was utilized in this study. A purposive sample included six Pacific Island women. Five of the six women had migrated to Hawaii from the island nations of Micronesia. The sixth participant was a Native Hawaiian who had lived in Micronesia and had returned to Hawaii. The collection and transcription of data were done by the first author. Data were categorized into themes independently by the three authors and bracketing was maintained throughout the study. The women identified the dichotomy of "big body" versus "small body" and the connotation of each body size in how they viewed the world around them. They shared their lifestyle and transitional changes in trying to adapt and ‘fit’ into the new lifestyle in Hawaii. These changes impacted their eating habits and work schedule, level of activity, and financial security. The women identified biopsychosocial concerns in their lives and the need to re-evaluate their "big body" size in relation to their health and physical and psychosocial changes. Implications for future research are to include a diverse representation of women from island countries within the Pacific Basin. The results of this study provided valuable information related to cultural relevance and sensitivity in working with Pacific Island women in managing their health.

Genetic diversity of Bactrocera dorsalis (Diptera: Tephritidae) on the Hawaiian islands: Implications for an introduction pathway into California

International Nuclear Information System (INIS)

Barr, Norman B.; Ledezma, Lisa A.; Bartels, David W.; Garza, Daniel; Leblanc, Luc; Jose, Michael San; Rubinoff, Daniel; Geib, Scott M.; Fujita, Brian; Kerr, Peter; Hauser, Martin; Gaimari, Stephen

2015-01-01

Population genetic diversity of the oriental fruit fly, Bactrocera dorsalis (Hendel), on the Hawaiian islands of Oahu, Maui, Kauai, and Hawaii (the Big Island) was estimated using DNA sequences of the mitochondrial cytochrome c oxidase subunit I gene. In total, 932 flies representing 36 sampled sites across the four islands were sequenced for a 1,500-bp fragment of the gene named the C1500 marker. Genetic variation was low on the Hawaiian Islands with >96% of flies having just two haplotypes: C1500- Haplotype 1 (63.2%) or C1500-Haplotype 2 (33.3%). The other 33 flies (3.5%) had haplotypes similar to the two dominant haplotypes. No population structure was detected among the islands or within islands. The two haplotypes were present at similar frequencies at each sample site, suggesting that flies on the various islands can be considered one population. Comparison of the Hawaiian data set to DNA sequences of 165 flies from outbreaks in California between 2006 and 2012 indicates that a single-source introduction pathway of Hawaiian origin cannot explain many of the flies in California. Hawaii, however, could not be excluded as a maternal source for 69 flies. There was no clear geographic association for Hawaiian or non-Hawaiian haplotypes in the Bay Area or Los Angeles Basin over time. This suggests that California experienced multiple, independent introductions from different sources. (author)

Magnitude of flood flows for selected annual exceedance probabilities in Rhode Island through 2010

Science.gov (United States)

Zarriello, Phillip J.; Ahearn, Elizabeth A.; Levin, Sara B.

2012-01-01

Heavy persistent rains from late February through March 2010 caused severe widespread flooding in Rhode Island that set or nearly set record flows and water levels at many long-term streamgages in the State. In response, the U.S. Geological Survey, in partnership with the Federal Emergency Management Agency, conducted a study to update estimates of flood magnitudes at streamgages and regional equations for estimating flood flows at ungaged locations. This report provides information needed for flood plain management, transportation infrastructure design, flood insurance studies, and other purposes that can help minimize future flood damages and risks. The magnitudes of floods were determined from the annual peak flows at 43 streamgages in Rhode Island (20 sites), Connecticut (14 sites), and Massachusetts (9 sites) using the standard Bulletin 17B log-Pearson type III method and a modification of this method called the expected moments algorithm (EMA) for 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probability (AEP) floods. Annual-peak flows were analyzed for the period of record through the 2010 water year; however, records were extended at 23 streamgages using the maintenance of variance extension (MOVE) procedure to best represent the longest period possible for determining the generalized skew and flood magnitudes. Generalized least square regression equations were developed from the flood quantiles computed at 41 streamgages (2 streamgages in Rhode Island with reported flood quantiles were not used in the regional regression because of regulation or redundancy) and their respective basin characteristics to estimate magnitude of floods at ungaged sites. Of 55 basin characteristics evaluated as potential explanatory variables, 3 were statistically significant—drainage area, stream density, and basin storage. The pseudo-coefficient of determination (pseudo-R2) indicates these three explanatory variables explain 95 to 96 percent of the variance

Data report: an assessment of the occurrence of human viruses in Long Island aquatic systems

Energy Technology Data Exchange (ETDEWEB)

Vaughn, J.M.; Landry, E.F.

1977-12-01

A virus survey was conducted in Nassau and Suffolk Counties under the auspices of the federally-funded ''208'' program from June 1976 to June 1977. The survey involved the concentration, enumeration, and identification of human enteroviruses from selected aquatic systems on Long Island including embayments, lakes, creeks, public drinking water supplies, groundwater influenced by wastewater recharge, sanitary landfills, and stormwater recharge basins; and the effluents from secondary and tertiary sewage treatment plants. Enteroviruses were isolated from all systems studied except the public water supply wells. As expected, viruses were most often encountered in the chlorinated effluents of sewage treatment plants. On two separate occasions, wild type Poliovirus was isolated from one of these plants. The limited sampling conducted at each site (1 per month) obviated any extensive interpretation of the data for the purpose of identifying the precise hazard posed by enteric viruses in Long Island waters. Among tentative conclusions were: support for the continued study of recharge of groundwater aquifers via the application of properly treated domestic wastewater to recharge basins; caution regarding placement of private septic systems in saturated zones near surface water bodies; the discharge of sewage effluents into embayments; and the identification of those areas requiring further virological study.

Runoff modeling of the Amazon basin using 18 O as a conservative tracer

International Nuclear Information System (INIS)

Mortatti, Jefferson; Victoria, Reynaldo L.; Moraes, Jorge M.; Rodrigues Junior, Jose C.; Matsumoto, Otavio M.

1997-01-01

Using the δO 18 O content of natural waters as a conservative tracer, a runoff modelling of the Amazon river basin was carried out in order to study the hydrological characteristics of the precipitation-runoff relationship. Measurements of the δ 18 O in rainfall waters made in the high Solimoes region at Benjamin Constant, in the central part of basin at Manaus, and at the mouth near the Marajo Island, while the river waters were measured at Obidos only, as a proxy for the mouth, during the 1973-1974 hydrological years. The hydrography separation of the Amazon river was performed using the isotopic method to estimate the contributions of the surface runoff (event water) and baseflow (pre-event water) components to the total river flow. At peak discharge, the average contribution of the baseflow was 57% of the total river flow. The annual average contributions for surface runoff and baseflow were 30.3 and 69.7%, respectively. The residence time of the subsurface water in the basin was estimated as being 7 months, by fitting a sinusoidal function to the isotopic values of rainfall and river waters. The low values of the amplitude damping in the basin suggest high mixing waters during the runoff process. (author). 21 refs., 4 figs., 1 tab

Canary Islands

Science.gov (United States)

1992-01-01

This easterly looking view shows the seven major volcanic islands of the Canary Island chain (28.0N, 16.5W) and offers a unique view of the islands that have become a frequent vacation spot for Europeans. The northwest coastline of Africa, (Morocco and Western Sahara), is visible in the background. Frequently, these islands create an impact on local weather (cloud formations) and ocean currents (island wakes) as seen in this photo.

The Solomon Islands Tsunami of 6 February 2013 in the Santa Cruz Islands: Field Survey and Modeling

Science.gov (United States)

Fritz, Hermann M.; Papantoniou, Antonios; Biukoto, Litea; Albert, Gilly; Wei, Yong

2014-05-01

observed on volcanic Tinakula Island and on Ndendo Island. Observations from the 2013 Santa Cruz tsunami are compared against the 2007 and 2010 Solomon Islands tsunamis. The field observations in the Santa Cruz Islands present an important dataset to assess tsunami impact in the near-source region. The tsunami was also recorded at deep-ocean tsunameters and tide gauges throughout the Pacific. These observations allow us to further investigate the physics of tsunami generation caused by the seismic process (or other non-seismic mechanisms). We use numerical model MOST to analyze the large runup and complex impact distribution caused by the Santa Cruz tsunami. Source models obtained using seismic data / tsunami data are carried out to initialize the tsunami model. MOST uses two sets of numerical grids to investigate both the near- and far-field aspects of the tsunami. The basin-scale modeling results are computed using a spatial resolution of 4 arc min (approx. 7,200 m) and compared with measurements at deep-ocean tsunameters. The near-field modeling is carried out using a series of telescoped grids up to a grid resolution of tens of meters to compare with the tsunami runup and flooding extent obtained through the field survey in the Solomon Islands. The modeling results emphasize the contrast between the tsunami impact on the exposed coastline and the sheltered Lata Bay stressing the problematic interpretation of a tsunami in progress based solely on near-source tide-gauge measurements. The team also interviewed eyewitnesses and educated residents about the tsunami hazard in numerous ad hoc presentations and discussions. The combination of ancestral knowledge and recent Solomon Islands wide geohazards education programs triggered an immediate spontaneous self-evacuation containing the death toll in the small evacuation window of few minutes between the end of the ground shaking and the onslaught of the tsunami. Fortunately school children were shown a video on the 1 April

The Ogaden Basin, Ethiopia: an underexplored sedimentary basin

Energy Technology Data Exchange (ETDEWEB)

Teitz, H.H.

1991-01-01

A brief article examines the Ogaden Basin in Ethiopia in terms of basin origin, basin fill and the hydrocarbon exploration history and results. The natural gas find in pre-Jurassic sandstones, which appears to contain substantial reserves, justifies continuing investigations in this largely underexplored basin. (UK).

Water resources in the Blackstone River basin, Massachusetts

Science.gov (United States)

Walker, Eugene H.; Krejmas, Bruce E.

1983-01-01

The Blackstone River heads in brooks 6 miles northwest of Worcester and drains about 330 square miles of central Massachusetts before crossing into Rhode Island at Woonsocket. The primary source of the Worcester water supply is reservoirs, but for the remaining 23 communities in the basin, the primary source is wells. Bedrock consists of granitic and metamorphic rocks. Till mantles the uplands and extends beneath stratified drift in the valleys. Stratified glacial drift, consisting of clay, silt, and fine sand deposited in lakes and coarse-textured sand and gravel deposited by streams, is found in lowlands and valleys. The bedrock aquifer is capable of sustaining rural domestic supplies throughout the Blackstone River basin. Bedrock wells yield an average of 10 gallons per minute, but some wells, especially those in lowlands where bedrock probably contains more fractures and receives more recharge than in the upland areas, yield as much as 100 gallons per minute. Glacial sand and gravel is the principal aquifer. It is capable of sustaining municipal supplies. Average daily pumpage from this aquifer in the Blackstone River basin was 10.4 million gallons per day in 1978. The median yield of large-diameter wells in the aquifer is 325 gallons per minute. The range of yields from these wells is 45 to 3,300 gallons per minute. The median specific capacity is about 30 gallons per minute per foot of drawdown.

Groundwater resources of Ribeira Fajã basin, island of São Nicolau, Cape Verde, West Africa

Science.gov (United States)

Heilweil, Victor M.; Gingerich, Stephen B.; Plummer, Niel; Verstraeten, Ingrid M.

2010-01-01

Groundwater resources in Cape Verde provide water for agriculture, industry, and human consumption. These resources are limited and susceptible to contamination. Additional groundwater resources are needed for continued agricultural development, particularly during times of drought, but increased use and (or) climatic change may have adverse effects on the quantity and quality of freshwater available. In volcanic island aquifers such as those of Cape Verde, a lens of fresh groundwater typically ?floats? upon a layer of brackish water at the freshwater/saltwater boundary, and increased pumping may cause salt water intrusion or other contamination. A recent U.S. Geological Survey study assessed baseline groundwater conditions in watersheds on three islands of Cape Verde to provide the scientific basis for sustainably developing water resources and minimizing future groundwater depletion and contamination.

Three trepanned skulls from the Copacabana Peninsula in the Titicaca Basin, Bolivia (800 BC-AD 1000).

Science.gov (United States)

Juengst, Sara L; Chávez, Sergio J

2015-06-01

This paper presents three trepanned skulls from the Copacabana Peninsula in the Titicaca Basin, dating from 800 BC to AD 1000. Trepanation has been practiced for two millennia in the Andes, with the earliest specimens coming from the coastal Paracas culture (circa 400 BC). Trepanned skulls have been found throughout the Andes, displaying a variety of techniques. This modification was practiced as surgical intervention after injury and treatment for headaches and other ailments, among other reasons (Verano, 2003: 234). With the exception of four examples from the Island of the Sun, few early cases of trepanation have been found in the Titicaca Basin of Peru and Bolivia. The three skulls presented here are important for several reasons: (1) they originate from a region under-represented in the literature on Andean trepanation, (2) they represent a variety of trepanation techniques, and (3) they confirm the practice of trepanation in the lake basin during the Early Horizon. Copyright © 2014 Elsevier Inc. All rights reserved.

Multidecadal shoreline changes of atoll islands in the Marshall Islands

Science.gov (United States)

Ford, M.

2012-12-01

Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.

Foundation Investigation for Ground Based Radar Project-Kwajalein Island, Marshall Islands

Science.gov (United States)

1990-04-01

iL_ COPY MISCELLANEOUS PAPER GL-90-5 i iFOUNDATION INVESTIGATION FOR GROUND BASED RADAR PROJECT--KWAJALEIN ISLAND, MARSHALL ISLANDS by Donald E...C!assification) Foundatioa Investigation for Ground Based Radar Project -- Kwajalein Island, Marshall Islands 12. PERSONAL AUTHOR(S) Yule, Donald E...investigation for the Ground Based Radar Project -- Kwajalein Island, Marshall Islands , are presented.- eophysical tests comprised of surface refrac- tion

Distribution of surficial sediment in Long Island Sound and adjacent waters: Texture and total organic carbon

Science.gov (United States)

Poppe, L.J.; Knebel, H.J.; Mlodzinska, Z.J.; Hastings, M.E.; Seekins, B.A.

2000-01-01

The surficial sediment distribution within Long Island Sound has been mapped and described using bottom samples, photography, and sidescan sonar, combined with information from the geologic literature. The distributions of sediment type and total organic carbon (TOC) reveal several broad trends that are largely related to the sea-floor geology, the bathymetry, and the effects of modern tidal- and wind-driven currents. Sediment types are most heterogeneous in bathymetrically complex and shallow nearshore areas; the heterogeneity diminishes and the texture fines with decreasing bottom-current energy. Lag deposits of gravel and gravelly sand dominate the surficial sediment texture in areas where bottom currents are the strongest (such as where tidal flow is constricted) and where glacial till crops out at the sea floor. Sand is the dominant sediment type in areas characterized by active sediment transport and in shallow areas affected by fine-grained winnowing. Silty sand and sand-silt-clay mark transitions within the basin from higher- to lower-energy environments, suggesting a diminished hydraulic ability to sort and transport sediment. Clayey silt and silty clay are the dominant sediment types accumulating in the central and western basins and in other areas characterized by long-term depositional environments. The amount of TOC in the sediments of Long Island Sound varies inversely with sediment grain size. Concentrations average more than 1.9% (dry weight) in clayey silt, but are less than 0.4% in sand. Generally, values for TOC increase both toward the west in the Sound and from the shallow margins to the deeper parts of the basin floor. Our data also suggest that TOC concentrations can vary seasonally.

Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

Energy Technology Data Exchange (ETDEWEB)

Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

2012-04-15

In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

International Nuclear Information System (INIS)

Moenkkoenen, H.

2012-04-01

In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

Island in an island – The suggestions for transportation improvement plan for Haidian Island, Haikou, Hainan

Directory of Open Access Journals (Sweden)

Sia Rosalind Juo Ling

2017-01-01

Full Text Available Haidian Island, which situated at the Northern part of Haikou City of Hainan Province, is an island within a city. Haidian Island is unique in term of it's development which centered around an university, the Hainan University, besides some others important landmarks, such as Haikou city hospital, Baishamen municipal park, Golf Driving Range etc. All commercials, residential, recreational activities etc are planned to serve Hainan University in particular. The study, taking ‘Haidian Island Area Development Control Plan’ as case study, would like to look into the importance of transportation and traffic planning. The study used observation, site investigation and traffic study methods to gather data needed. Firstly the study analyzed the current state of transportation system for Haidian Island in accordance to the Island Development Control plan and Haikou master plan and identified the problems. Then, the study made some recommendations for these problems. The study highlighted the important of non-motorized, cycling and walking as the main transportation system for an education-based island and as supportive to domestic tourism activities found. The transportation planning suggested by the study took ‘green and low-carbon’ approaches considered the role of University as the core activity in the island.

Gas and porewater composition of shallow sediments in the Tuaheni Basin, New Zealand

Science.gov (United States)

Rose, P. S.; Coffin, R. B.; Yoza, B.; Boyd, T. J.; Crutchley, G. J.; Mountjoy, J. J.; Pecher, I. A.

2015-12-01

Seismic profiles collected during previous investigations on the Hikurangi Margin, off the North Island, New Zealand showed bottom simulating reflectors (BSRs), which are generally indicative of the presence of free gas. Further, double BSRs clearly identified in the Tuaheni Basin were hypothesized to result from differences in gas composition and fluid migration. During a cruise on the RV Tangaroa in June 2015 (TAN 1508) additional seismic data were collected and used to identify piston coring targets. Coring locations were selected to sample around BSR pinch-outs and possible fluid migration pathways to determine gas composition and flux. Shallow sediments collected in June 2015 in the Tuaheni Basin had relatively low sediment headspace CH4 concentrations (6000ppm. Higher molecular weight alkanes were not detected in the sediment headspace gas at any location. Sediment porewater sulfate, chloride and sulfide concentrations will be presented with CH4concentration profiles and geophysical data.

Water and tourism on Mediterranean islands

Energy Technology Data Exchange (ETDEWEB)

Igel, Wolf von; Candela, Lucila [Technical Univ. of Catalonia, Barcelona (Spain). Geotechnical Engineering and Geosciences Dept.

2005-07-01

An increased tourism development has taken place in the Mediterranean basin. This has induced some positive and negative consequences over diverse aspects of life and the natural system. One important consequence has been the increasing pressure put on natural resources, namely on fresh water resources. The patterns of water use related to tourism activity that lead to a situation of scarcity of water resources in a Mediterranean islands context are presented. Next are presented the main problems of hydrological, environmental and socio-economic nature that are a consequence of the increasing tourism development and accompanying increasing scarcity of water resources. As one of these main problems is often the insufficient water supply to meet the water demand, a discussion of the pros and cons of the diverse alternatives to increase the water supply and an explanation of some alternatives to control the water demand are presented. (orig.)

Using a Reactive Transport Simulator to Simulate CH4 Production from Bear Island Basin in the Barents Sea Utilizing the Depressurization Method†

Directory of Open Access Journals (Sweden)

Khadijeh Qorbani

2017-02-01

Full Text Available The enormous amount of methane stored in natural gas hydrates (NGHsworldwide offers a significant potential source of energy. NGHs will be generally unable to reach thermodynamic equilibrium at their in situ reservoir conditions due to the number of active phases involved. Lack of reliable field data makes it difficult to predict the production potential and safety of CH4 production from NGHs. While the computer simulations will never be able to replace field data, one can apply state-of-the-artmodellingtechniquestoevaluateseveralpossiblelong-termscenarios. Realistic kinetic models for hydrate dissociation and reformation will be required, as well as analysis of all phase transition routes. This work utilizes our in-house extension of RetrasoCodeBright (RCB, a reactive transport simulator, to perform a gas hydrate production case study of the Bjørnøya (Bear Island basin, a promising field with very limited geological data reported by available field studies. The use of a reactive transport simulator allowed us to implement non-equilibrium thermodynamics for analysisofCH4 production from the gas hydrates by treating each phase transition involving hydrates as a pseudo reaction. Our results showed a rapid propagation of the pressure drop through the reservoir following the imposition of pressure drawdown at the well. Consequently, gas hydrate dissociation and CH4 production began in the early stages of the five-year simulation period.

Basins of attraction of the bistable region of time-delayed cutting dynamics

Science.gov (United States)

Yan, Yao; Xu, Jian; Wiercigroch, Marian

2017-09-01

This paper investigates the effects of bistability in a nonsmooth time-delayed dynamical system, which is often manifested in science and engineering. Previous studies on cutting dynamics have demonstrated persistent coexistence of chatter and chatter-free responses in a bistable region located in the linearly stable zone. As there is no widely accepted definition of basins of attraction for time-delayed systems, bistable regions are coined as unsafe zones (UZs). Hence, we have attempted to define the basins of attraction and stability basins for a typical delayed system to get insight into the bistability in systems with time delays. Special attention was paid to the influences of delayed initial conditions, starting points, and states at time zero on the long-term dynamics of time-delayed systems. By using this concept, it has been confirmed that the chatter is prone to occur when the waviness frequency in the workpiece surface coincides with the effective natural frequency of the cutting process. Further investigations unveil a thin "boundary layer" inside the UZ in the immediate vicinity of the stability boundary, in which we observe an extremely fast growth of the chatter basin stability. The results reveal that the system is more stable when the initial cutting depth is smaller. The physics of the tool deflection at the instant of the tool-workpiece engagement is used to evaluate the cutting safety, and the safe level could be zero when the geometry of tool engagement is unfavorable. Finally, the basins of attraction are used to quench the chatter by a single strike, where the resultant "islands" offer an opportunity to suppress the chatter even when the cutting is very close to the stability boundary.

Basins of attraction of the bistable region of time-delayed cutting dynamics.

Science.gov (United States)

Yan, Yao; Xu, Jian; Wiercigroch, Marian

2017-09-01

This paper investigates the effects of bistability in a nonsmooth time-delayed dynamical system, which is often manifested in science and engineering. Previous studies on cutting dynamics have demonstrated persistent coexistence of chatter and chatter-free responses in a bistable region located in the linearly stable zone. As there is no widely accepted definition of basins of attraction for time-delayed systems, bistable regions are coined as unsafe zones (UZs). Hence, we have attempted to define the basins of attraction and stability basins for a typical delayed system to get insight into the bistability in systems with time delays. Special attention was paid to the influences of delayed initial conditions, starting points, and states at time zero on the long-term dynamics of time-delayed systems. By using this concept, it has been confirmed that the chatter is prone to occur when the waviness frequency in the workpiece surface coincides with the effective natural frequency of the cutting process. Further investigations unveil a thin "boundary layer" inside the UZ in the immediate vicinity of the stability boundary, in which we observe an extremely fast growth of the chatter basin stability. The results reveal that the system is more stable when the initial cutting depth is smaller. The physics of the tool deflection at the instant of the tool-workpiece engagement is used to evaluate the cutting safety, and the safe level could be zero when the geometry of tool engagement is unfavorable. Finally, the basins of attraction are used to quench the chatter by a single strike, where the resultant "islands" offer an opportunity to suppress the chatter even when the cutting is very close to the stability boundary.

Estimating flexural rigidity and load magnitude required for formation of Ross Island flexure moat

Science.gov (United States)

Jha, S.; Harry, D. L.; Wenman, C. P.

2017-12-01

Lithospheric flexural subsidence around Ross Island in West Antarctica led to formation of the Ross Island flexure moat. This subsidence was caused by two major volcanic phases on Ross Island. The first phase saw the first surficial expression of Ross Island and volcanism at Mt. Bird to the north of Ross Island, which lasted from 5.2 - 2.9 Ma. The second phase lasted from 1.78 Ma to present and is comprised of eruptions from Mt. Terror to the east, Mt. Erebus to the west and Hut Point Peninsula (HPP) to the south of Ross Island. Flexural subsidence of the lithosphere due to volcanism on Ross Island led to formation of a sedimentary moat around the island, which is preserved in stratigraphy imaged on seismic reflection profiles. We identified 5 unconformities (from deepest upward Ri, RMU1, RMU2, RMU3, RMU4) in the seismic surveys which correspond to flexural subsidence episodes around Ross Island since early Pliocene. Ri (4.4 Ma) lies near the bottom of the flexural moat and RMU4 near the seafloor and top of the moat fill. These unconformities were used to make isopach maps to constrain flexure modeling of the area. Isopach maps show circular or semi-circular flexure basins around Ross Island which is approximated using a continuous plate, point load flexure model. We used Ri - sea floor isopach to constrain flexure models for 5 profiles centered on 4 volcanic centers and trending radially out of Ross Island. Flexure models along two profiles beginning on Mt. Bird and one profile off HPP show a flexural rigidity range of 1.47 - 6.44 x 1018 Nm with load center of mass on Mt. Bird and on HPP, respectively. A similar model along a profile initiating on Mt. Terror, passing through Mt Erebus and extending west of Ross Island across the moat, yielded a higher flexural rigidity estimate of 2.03 x 1019 Nm with load centered at Mt. Erebus. A flexure model to the north east of Ross Island along a profile beginning at Mt Terror and trending north, provide the highest flexural

Integrated Hydrographical Basin Management. Study Case - Crasna River Basin

Science.gov (United States)

Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

2017-10-01

Hydrographical basins are important from hydrological, economic and ecological points of view. They receive and channel the runoff from rainfall and snowmelt which, when adequate managed, can provide fresh water necessary for water supply, irrigation, food industry, animal husbandry, hydrotechnical arrangements and recreation. Hydrographical basin planning and management follows the efficient use of available water resources in order to satisfy environmental, economic and social necessities and constraints. This can be facilitated by a decision support system that links hydrological, meteorological, engineering, water quality, agriculture, environmental, and other information in an integrated framework. In the last few decades different modelling tools for resolving problems regarding water quantity and quality were developed, respectively water resources management. Watershed models have been developed to the understanding of water cycle and pollution dynamics, and used to evaluate the impacts of hydrotechnical arrangements and land use management options on water quantity, quality, mitigation measures and possible global changes. Models have been used for planning monitoring network and to develop plans for intervention in case of hydrological disasters: floods, flash floods, drought and pollution. MIKE HYDRO Basin is a multi-purpose, map-centric decision support tool for integrated hydrographical basin analysis, planning and management. MIKE HYDRO Basin is designed for analyzing water sharing issues at international, national and local hydrographical basin level. MIKE HYDRO Basin uses a simplified mathematical representation of the hydrographical basin including the configuration of river and reservoir systems, catchment hydrology and existing and potential water user schemes with their various demands including a rigorous irrigation scheme module. This paper analyzes the importance and principles of integrated hydrographical basin management and develop a case

Islands and non-islands in native and heritage Korean

Directory of Open Access Journals (Sweden)

Boyoung eKim

2016-02-01

Full Text Available To a large extent, island phenomena are cross-linguistically invariable, but English and Korean present some striking differences in this domain. English has wh-movement and Korean does not, and while both languages show sensitivity to wh-islands, only English has island effects for adjunct clauses. Given this complex set of differences, one might expect Korean/English bilinguals, and especially heritage Korean speakers (i.e. early bilinguals whose L2 became their dominant language during childhood to be different from native speakers, since heritage speakers have had more limited exposure to Korean, may have had incomplete acquisition and/or attrition, and may show significant transfer effects from the L2. Here we examine islands in heritage speakers of Korean in the U.S. Through a series of four formal acceptability experiments comparing these heritage speakers with native speakers residing in Korea, we show that the two groups are remarkably similar. Both show clear evidence for wh-islands and an equally clear lack of adjunct island effects. Given the very different linguistic environment that the heritage speakers have had since early childhood, this result lends support to the idea that island phenomena are largely immune to environmental influences and stem from deeper properties of the processor and/or grammar. Similarly, it casts some doubt on recent proposals that islands are learned from the input.

Class renormalization: islands around islands

International Nuclear Information System (INIS)

Meiss, J.D.

1986-01-01

An orbit of 'class' is one that rotates about a periodic orbit of one lower class with definite frequency. This contrasts to the 'level' of a periodic orbit which is the number of elements in its continued fraction expansion. Level renormalization is conventionally used to study the structure of quasi-periodic orbits. The scaling structure of periodic orbits encircling other periodic orbits in area preserving maps is discussed here. Fixed points corresponding to the accumulation of p/q bifurcations are found and scaling exponents determined. Fixed points for q > 2 correspond to self-similar islands around islands. Frequencies of the island boundary circles at the fixed points are obtained. Importance of this scaling for the motion of particles in stochastic regions is emphasized. (author)

Groundwater resources of Ribeira Paúl basin, island of Santo Antão, Cape Verde, West Africa

Science.gov (United States)

Heilweil, Victor M.; Gingerich, Stephen B.; Verstraeten, Ingrid M.

2010-01-01

Groundwater resources in Cape Verde provide water for agriculture, industry, and human consumption. These resources are limited and susceptible to contamination. Additional groundwater resources are needed for continued agricultural development, particularly during times of drought, but increased use and (or) climatic change may have adverse effects on the quantity and quality of freshwater available. In volcanic island aquifers such as those of Cape Verde, a lens of fresh groundwater typically ?floats? upon a layer of brackish water at the freshwater/saltwater boundary, and increased pumping may cause salt water intrusion or other contamination. A recent U.S. Geological Survey study assessed baseline groundwater conditions in watersheds on three islands of Cape Verde to provide the scientific basis for sustainably developing water resources and minimizing future groundwater depletion and contamination.

Aeromagnetic and aerial photographic survey in the South Shetland Islands,Antarctica, conducted by a small unmanned aerial vehicle (Ant-Plane

Directory of Open Access Journals (Sweden)

Minoru Funaki

2013-07-01

Full Text Available Two small unmanned aerial vehicles, Ant-Plane 6 and Ant-Plane 3, were assembled using parts and technologies developed for model airplanes. The aerial vehicles were scheduled to conduct aero magnetic and photographic surveys of the Brans?eld Basin, from a takeoff runway at Marsh Air?eld on the South Shetland Islands, Antarctica, during January 2011. However, the scheduled surveys were not conducted on account of poor weather. Research was later conducted on a glacier, using a takeoff runway at St. Kliment Ohridski Base, Livingston Island, during December 2011. A ?ight from St. Kliment Ohridski Base to Deception Island yielded satisfactory results; the total distance of 302.4 km was traversed in 3 h 7 min (3:07. On this ?ight, aeromagnetic and aerial photographic data were obtained from an altitude of 780 m for a 9×18 km area on the northern half of Deception Island. Aerial photographs of Deception Island and South Bay showed the distributions of glaciers and their crevasses. The Ant-Plane ?ew over the Antarctic horizon and surveyed above Deception Island. That was the successful venture of this kind, demonstrating that airborne surveys by Ant-Planes are useful for Antarctic research investigations. Airborne surveys provide a safe and economical approach to data acquisition as compared with manned aerial operations.

Tsunami deposits in the Balearic Islands (western Mediterranean) and implications for hazard assessment.

Science.gov (United States)

Paris, Raphael; Wassmer, Patrick; Roger, Jean; Loevenbruck, Anne

2010-05-01

Significant earthquakes occur along the north Algerian and Carboneras faults (e.g. Djijelli 1865, Zemmouri 2003) and they may generate tsunamis in the western Mediterranean Basin and Alboran Sea, where tsunami hazard are poorly documented. The coast of southern Spain and Balearic Islands are densely populated, with touristic areas and important harbors. The 2003 event generated a small tsunami in the Balearic Islands (ships were moved by oscillations during more than 2 hours in some harbors). Reicherter et al. (2009) found evidences of two past tsunamis in lagoon of the Cabo de Gata (near Almeria), which they ascribed to the 1522 earthquake and an earlier event (islands revealed few evidences of past tsunamis. Thin sandy layers with marine bioclasts, possibly deposited by tsunamis, were found in three areas at altitudes always lower than 2m. Boulder clusters were found along the southern coast of Mallorca, but they could have been deposited by storms as well. These investigations are realized in the framework of the MAREMOTI project, funded by the French ANR and leaded by the CEA - DASE. Reicherter, K., Becker-Heidmann, P., 2009. Tsunami deposits in the western Mediterranean: remains of the 1522 Almeria earthquake? Geological Society Special Publications, London, 316, 217-235.

Implementation of State Obligations and Responsibility Ensuring the Availability of Clean Water in Karimunjawa Islands

Science.gov (United States)

Rahayu; Soeprobowati, Tri Retnaningsih

2018-02-01

This article aims to analyze the implementation of state obligations and responsibility ensuring the availability of clean water as part of human rights in Karimunjawa islands. The analysis based on principle of the State obligations and responsibility to fulfill their citizen right. Water sources in Karimunjawa Islands is very limited. It depend on forest conservation. Around 9.600 peoples live in Karimunjawa Islands, but Karimunjawa is non groundwater basin region. It means, Karimunjawa doesn't have groundwater potential. The quantity of water depends on the season. The solution to maintain the sustainability of clean water is piping from water reservoir to residential areas. The problem is there are so many hotels in Karimunjawa islands, it disrupted the fulfillment of clean water. Besides utilizing water from reservoir, many hotels drilled the ground to get water. It had impact to the availibity of water in dry season and affected to fulfillment of water supply for Karimunjawa people. There is no specific regulation and policy to solve this problem. Clean water management is doing by Karimunjawa's people. Meanwhile, based on Mahkamah Konstitusi Decree number 85/PUU-XI/2013, state is a rights holder to dominate the water in accordance with the Articles 33 paragraph (2) and (3) UUD NRI 1945, so the government has an obligation to make a policy, regulations, management, and supervision.

Capturing the Petermann Ice Island Flux With the CI2D3 Database

Science.gov (United States)

Crawford, A. J.; Crocker, G.; Mueller, D.; Saper, R.; Desjardins, L.; Carrieres, T.

2017-12-01

The Petermann Glacier ice tongue lost >460 km2 of areal extent ( 38 Gt of mass) due to three large calving events in 2008, 2010 and 2012, as well as three previously unrecorded events in 2011 and 2012. Hundreds of ice islands subsequently drifted south between Hall Basin and Newfoundland's Grand Banks, but no systematic data collection or analysis has been conducted for the full flux of fragments prior to the present study. To accomplish this, the Canadian Ice Service's extensive RADARSAT-1 and -2 synthetic aperture radar image archive was mined to create the Canadian Ice Island Drift, Deterioration and Detection (CI2D3) Database. Over 15000 fragments have been digitized in GIS software from 3200 SAR scenes. A unique characteristic of the database is the inclusion of the lineage (i.e., connecting repeat observations or mother-daughter fragments) for all tracked fragments with areas >0.25 km2. This genealogical information was used to isolate ice islands that were about to fracture in order to assess the environmental conditions and morphological characteristics that influence this deterioration mechanism. Fracture counts showed a significant relationship with sea ice concentration (r = -0.56). However, variations in relative thickness played a large role in fracturing likelihood regardless of sea ice conditions. The exceedance probability of the daughter fragment length was calculated, as is often conducted for offshore industry hazard assessment. Grounded ice islands, which are hazards to seafloor installations and disturb benthic ecology, were recognized from their negligible drift speeds and two grounding hot-spots were identified along the Coburg and eastern Baffin island coasts. Petermann ice islands have been noted to drift along specific isobaths due to the influence of bathymetry on ocean currents. 50% of observations occurred between the 100 and 300 m isobaths, and smaller ice islands were observed more frequently in deeper regions. The CI2D3 Database can

Depositional environment of near-surface sediments, King George Basin, Bransfield Strait, Antarctica

Science.gov (United States)

Yoon, H. I.; Park, B. K.; Chang, S. K.; Han, M. W.; Oh, J. K.

1994-03-01

Four sediment cores were collected to determine the depositional environments of the King George Basin northeast of Bransfield Strait, Antarctica. The cored section revealed three distinct lithofacies: laminated siliceous ooze derived from an increased paleoproductivity near the receding sea-ice edges, massive muds that resulted from hemipelagic sedimentation in open water, and graded sediments that originated from nearby local seamounts by turbidity currents. Clay mineral data of the cores indicate a decreasing importance of volcanic activity through time. Active volcanism and hydrothermal activity appear to be responsible for the enrichment of smectite near the Penguin and Bridgeman Islands.

Cold Outbreaks at the Mesoscale in the Western Mediterranean Basin: From Raincells to Rainbands

Directory of Open Access Journals (Sweden)

Jordi Mazon

2017-01-01

Full Text Available This paper investigates cold outbreaks that form offshore density currents within the whole mesoscale over the Western Mediterranean basin. Reflectivity radar and satellite images are used to detect clouds and precipitation that are associated with these density currents in the meso-α, meso-β, and meso-γ over the Western Mediterranean basin (WMB. Version 3.3 of the WRF-ARW model is used to describe the formation and evolution of these density currents and to estimate their lifetime as well as horizontal and vertical scales. Based on the observations and simulations, this paper suggests that a new perspective could effectively be adopted regarding the WMB region delineated by the Balearic Islands, the northeastern Iberian Peninsula, and the Gulf of Lion, where inland cold outbreaks develop into density currents that move offshore and can produce precipitation ranging from raincells to rainbands at the whole mesoscale.

K-Ar age and tectonic setting of brannerite-mineralized Futagojima granodiorite, Koshiki Islands, Southern Kyushu

International Nuclear Information System (INIS)

Ishihara, Shunso; Shibata, Ken; Terashima, Shigeru

1984-01-01

Futagojima granodiorite, which was previously thought to be a part of Cretaceous Ryoke granitoids, is turned out to be upper Miocene granitoids (7.5 Ma). The granodiorite contains magnetite and is depleted in lithophile components. This is characteristics of magnetite-series granitoids in the Green Tuff terrains. All the Miocene granitoids in Koshiki Islands are relatively mafic consisting of hornblende-bearing facies such as quartz diorite, tonalite and granodiorite; thus belonging to I-type magnetite series. These rocks are considered to have generated at depth and formed along a rift zone during Miocene time (13 - 7 Ma). Thus, Koshiki Islands may represent an aborted rift at margin of the Danjo basin. Miocene granitoids of Koshiki Islands are small stocks but magmatic-hydrothermal ore deposits are only seen in Futagojima. This localization of mineralization is explained by a high degree of magmatic fractionation, which is only observed in Futagojima and by a low rate of erosion to preserve the mineralized horizons. Mineralization here is unique having brannerite-magnetite and chalcopyrite-molybdenite-quartz assemblages. No gold and silver were detected from the vein-type deposit. (author)

Well Water and Subsurface Salinity of Tuba Basin Langkawi by Hydrochemical Analysis and Vertical Electrical Resistivity Survey

International Nuclear Information System (INIS)

Umar Hamzah; Abdul Rahim Samsudin; Abdul Ghani Rafek; Khairul Azlan Razak

2009-01-01

Tuba basin is an alluvial deposit located between granitic hill in the western part of Tuba Island and the Setul formation sedimentary rocks in the eastern site of the island. This basin stretched along 3 km in the NE-SW direction with an estimated width of about 2 km. A geophysical survey using geo electrical technique was carried out to figure out the subsurface structure, to detect the presence of underground aquifers and to investigate any saltwater intrusion into these aquifers in the basin. Concentrations of several elements in the well water were also analyzed to investigate any occurrence of salt water intrusion into the coastal aquifers. For this purpose, the vertical electrical sounding surveys were carried out at 22 randomly distributed stations in the study area. Water samples were also taken from 11 wells for hydrochemical analysis in the laboratory. Our results showed that all water samples were of fresh water type. Electrical resistivity profile constructed from stations located in NE-SW direction from Teluk Berembang to Telok Bujur shows a wide range of resistivities ranging from 4 Ωm to infinity. The top layer with a thickness of 1-3 m and resistivity values of 4 - 12 Ωm is interpreted as clay zone. This layer is overlying a much thicker layer of 10-50 m with resistivity values of 2 - 280 Ωm representing sandy material that may contain fresh water or sand with brackish water. Layers with resistivity values from thousands ohm.m to infinity are interpreted as either granite or limestone bedrock. Maximum thickness observed in this resistivity survey is approximately 70 m. (author)

Airborne dust transport to the eastern Pacific Ocean off southern California: Evidence from San Clemente Island

Science.gov (United States)

Muhs, D.R.; Budahn, J.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.

2007-01-01

Islands are natural dust traps, and San Clemente Island, California, is a good example. Soils on marine terraces cut into Miocene andesite on this island are clay-rich Vertisols or Alfisols with vertic properties. These soils are overlain by silt-rich mantles, 5-20 cm thick, that contrast sharply with the underlying clay-rich subsoils. The silt mantles have a mineralogy that is distinct from the island bedrock. Silt mantles are rich in quartz, which is rare in the island andesite. The clay fraction of the silt mantles is dominated by mica, also absent from local andesite, and contrasts with the subsoils, dominated by smectite. Ternary plots of immobile trace elements (Sc-Th-La and Ta-Nd-Cr) show that the island andesite has a composition intermediate between average upper continental crust and average oceanic crust. In contrast, the silt and, to a lesser extent, clay fractions of the silt mantles have compositions closer to average upper continental crust. The silt mantles have particle size distributions similar to loess and Mojave Desert dust, but are coarser than long-range-transported Asian dust. We infer from these observations that the silt mantles are derived from airborne dust from the North American mainland, probably river valleys in the coastal mountains of southern California and/or the Mojave Desert. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. Examination of satellite imagery shows that easterly Santa Ana winds carry abundant dust to the eastern Pacific Ocean and the California Channel Islands. Airborne dust from mainland North America may be an important component of the offshore sediment budget in the easternmost Pacific Ocean, a finding of potential biogeochemical and climatic significance.

Tuppiap Qeqertaa (Tobias Island): a newly discovered island off northeast Greenland

DEFF Research Database (Denmark)

Bennike, O.; Mikkelsen, N.; Forsberg, René

2006-01-01

The small island of Tuppiap Qeqertaa, formerly known as Tobias circle divide or Tobias Island, is situated 80 km off the northeast Greenland coast. The island was discovered in 1993 and is approximately 2 km long and 1.5 km wide. Most of the island is covered by an ice cap that rises to 35 in abo...

Diomede Islands, Bering Straight

Science.gov (United States)

2008-01-01

The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations. The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Sociodemographic Factors Influencing Island Food Consumption in the Pacific Islander Health Study

OpenAIRE

Baumhofer, Nicole Kau'i

2016-01-01

This dissertation explores the relationships between island food consumption, sociodemographic variables, and cardiovascular risk using data from the Pacific Islander Health Study (PIHS). Chapter 1 explores the associations between self-reported level of island food consumption and key covariates. Island food consumption was modeled using Poisson regression and adjusted for demographic, socioeconomic, and cultural characteristics. Increased Pacific Island cultural affinity was the strongest p...

Transition of magma genesis estimated by change of chemical composition of Izu-bonin arc volcanism associated with spreading of Shikoku Basin

Science.gov (United States)

Haraguchi, S.; Ishii, T.

2006-12-01

Arc volcanism in the Izu-Ogasawara arc is separated into first and latter term at the separate of Shikoku Basin. Middle to late Eocene early arc volcanism formed a vast terrane of boninites and island arc tholeiites that is unlike active arc systems. A following modern-style arc volcanism was active during the Oligocene, along which intense tholeiitic and calc-alkaline volcanism continued until 29Ma, before spreading of the back- arc basin. The recent arc volcanism in the Izu-Ogasawara arc have started in the middle Miocene, and it is assumed that arc volcanism were decline during spreading of back-arc basin. In the northern Kyushu-Palau Ridge, submarine bottom materials were dredged during the KT95-9 and KT97-8 cruise by the R/V Tansei-maru, Ocean Research Institute, university of Tokyo, and basaltic to andesitic volcanic rocks were recovered during both cruise except for Komahashi-Daini Seamount where recovered acidic plutonic rocks. Komahashi-Daini Seamount tonalite show 37.5Ma of K-Ar dating, and this age indicates early stage of normal arc volcanism. These volcanic rocks are mainly cpx basalt to andesite. Two pyroxene basalt and andesite are only found from Miyazaki Seamount, northern end of the Kyushu-Palau Ridge. Volcanic rocks show different characteristics from first term volcanism in the Izu-Ogasawara forearc rise and recent arc volcanism. The most characteristic is high content of incompatible elements, that is, these volcanics show two to three times content of incompatible elements to Komahashi-Daini Seamount tonalite and former normal arc volcanism in the Izu outer arc (ODP Leg126), and higher content than recent Izu arc volcanism. This characteristic is similar to some volcanics at the ODP Leg59 Site448 in the central Kyushu- Palau Ridge. Site448 volcanic rocks show 32-33Ma of Ar-Ar ages, which considered beginning of activity of Parece Vela Basin. It is considered that the dredged volcanic rocks are uppermost part of volcanism before spreading of

Paradise Islands? Island States and Environmental Performance

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Sverker C. Jagers

2016-03-01

Full Text Available Island states have been shown to outperform continental states on a number of large-scale coordination-related outcomes, such as levels of democracy and institutional quality. The argument developed and tested in this article contends that the same kind of logic may apply to islands’ environmental performance, too. However, the empirical analysis shows mixed results. Among the 105 environmental outcomes that we analyzed, being an island only has a positive impact on 20 of them. For example, island states tend to outcompete continental states with respect to several indicators related to water quality but not in aspects related to biodiversity, protected areas, or environmental regulations. In addition, the causal factors previously suggested to make islands outperform continental states in terms of coordination have weak explanatory power in predicting islands’ environmental performance. We conclude the paper by discussing how these interesting findings can be further explored.

Identification of hydrogeochemical processes and pollution sources of groundwater nitrate in Leiming Basin of Hainan island, Southern China

Science.gov (United States)

Shaowen, Y.; Zhan, Y., , Dr; Li, Q.

2017-12-01

Identifying the evolution of groundwater quality is important for the control and management of groundwater resources. The main aims of the present study are to identify the major factors affecting hydrogeochemistry of groundwater resources and to evaluate the potential sources of groundwater nitrate in Leiming basin using chemical and isotopic methods. The majority of samples belong to Na-Cl water type and are followed by Ca-HCO3 and mixed Ca-Na-HCO3. The δ18O and δ2H values in groundwater indicate that the shallow fissure groundwater is mainly recharged by rainfall. The evaporated surface water is another significant origin of groundwater. The weathering and dissolution of different rocks and minerals, input of precipitation, evaporation, ion exchange and anthropogenic activities, especially agricultural activities, influence the hydrogeochemistry of the study area. NO- 3 concentration in the groundwater varies from 0.7 to 51.7 mg/L and high values are mainly occurred in the densely populated area. The combined use of isotopic values and hydrochemical data suggests that the NO- 3 load in Leiming basin is not only derived from agricultural activities but also from other sources such as waste water and atmospheric deposition. Fertilizer is considered as the major source of NO- 3 in the groundwater in Leiming basin.

Quaternary volcanism in Deception Island (Antarctica): South Shetland Trench subduction-related signature in the Bransfield Basin back arc domain; Vulcanismo cuaternario de la Isla Decepcion (Antartida): una signatura relacionada con la subduccion de la Fosa de las Shetland del Sur en el dominio de tras-arco de la Cuenca de Bransfield

Energy Technology Data Exchange (ETDEWEB)

Gale, C.; Ubide, T.; Lago, M.; Gil-Imaz, A.; Gil-Pena, I.; Galindo-Zaldivar, J.; Rey, J.; Maestro, A.; Lopez-Martinez, J.

2014-06-01

Deception Island shows a volcanism related to the Phoenix Plate subduction and roll-back under South Shetland Block in the present times. The development of the island is related to the evolution and collapse of a volcanic caldera, and this study is focused on the petrology, mineralogy and geochemistry of the post-caldera rocks. We have made a study of the lava flows, dikes and the youngest historic eruption in 1970. These rocks range from dacite to rhyolite and have a microporphyritic texture with olivine and minor clinopyroxene. A pre-caldera basaltic andesite has also been studied. It has a microporphyritic texture with clinopyroxene. The intermediate and acid compositions alternating in the volcanostratigraphic sequence suggest either mafic recharge events or melt extraction from different levels in the deep magmatic system. All the studied compositions share a subduction-related signature similar to other magmatics from the Bransfield Basin. However, compositional differences between pre-caldera and post-caldera rocks indicate a different magma source and depth of crystallisation. According to the geothermobarometric calculations the pre-caldera magmas started to crystallise at deeper levels (13.5-15 km) than the post-caldera magmas (6.2-7.8 km). Specifically, the postcaldera magmas indicate a smaller influence of the subducting slab in the southwestern part of the Bransfield Basin in respect to the available data from other sectors as well as the involvement of crustal contamination in the genesis of the magmas. (Author)

Early and late cretaceous magmatism from Sao Sebastiao island (SE-Brazil): geochemistry and petrology

International Nuclear Information System (INIS)

Bellieni, G.; Cavazzini, G.; Montes-Lauar, C.R.; Melfi, A.J.; Pacca, I.G.; De Min, A.; Piccirillo, E.M.

1990-01-01

The Sao Sebastiao island (236 km 2 ), located along the coast of the Sao Paulo State (Southern Brazil), is characterized by precambrian granitic affected by the Brasiliano tectonic-metamorphic cycle. This crystalline basement is intruded by Early Cretaceous (EC) sub alkaline basic and acid dykes, as well as by Late Cretaceous (LC) alkaline stocks (syenites) and dykes (basanite to phonolite). Geochemical, Sr-isotopic and mineral chemistry data point out that: EC-dykes reveal a basic-acid bimodal character, similar to that of the 'coeval' Parana basin flood volcanics; the acid dykes correspond, in composition, to the acid volcanics of the northern Parana basin: the EC-dykes can represent the eastern extension of the inland Santos-Rio de Janeiro dyke swarm, and LC alkaline stocks and dykes constitute distinct groups, characterized by different Sr-isotope initial ratios (syenites: av. 0.7052 and basanites + tephrites = av. 0.7045), which indicate that they are related to different time-integrated mantle source materials. (author)

Geometry and structure of the pull-apart basins developed along the western South American-Scotia plate boundary (SW Atlantic Ocean)

Science.gov (United States)

Esteban, F. D.; Tassone, A.; Isola, J. I.; Lodolo, E.; Menichetti, M.

2018-04-01

The South American-Scotia plate boundary is a left-lateral fault system which runs roughly E-W for more than 3000 km across the SW Atlantic Ocean and the Tierra del Fuego Island, reaching to the west the southern Chile Trench. Analyses of a large dataset of single- and multi-channel seismic reflection profiles acquired offshore has allowed to map the trace of the plate boundary from Tierra del Fuego to the Malvinas Trough, a tectonic depression located in the eastern part of the fault system, and to reconstruct the shape and geometry of the basins formed along the principal displacement zone of the fault system. Three main Neogene pull-apart basins that range from 70 to 100 km in length, and from 12 to 22 km in width, have been identified along this segment of the plate boundary. These basins have elongated shapes with their major axes parallel to the ENE-WSW direction of the fault zone. The sedimentary architecture and the infill geometry of the basins suggest that they represent mostly strike-slip dominated transtension basins which propagated from E to W. The basins imaged by seismic data show in some cases geometrical and structural features linked to the possible reactivation of previous wedge-top basins and inherited structures pertaining to the external front of the Magallanes fold-and-thrust compression belt, along which the South American-Scotia fault system has been superimposed. It is suggested that the sequence of the elongated basins occur symmetrically to a thorough going strike-slip fault, in a left-stepping geometrical arrangement, in a manner similar to those basins seen in other transcurrent environments.

Cobalt- and platinum-rich ferromanganese crusts and associated substrate rocks from the Marshall Islands

Science.gov (United States)

Hein, J.R.; Schwab, W.C.; Davis, A.

1988-01-01

Ferromanganese crusts cover most hard substrates on seafloor edifices in the central Pacific basin. Crust samples and their associated substrates from seven volcanic edifices of Cretaceous age along the Ratak chain of the Marshall Islands are discussed. The two most abundant substrate lithologies recovered were limestone, dominantly fore-reef slope deposits, and volcanic breccia composed primarily of differentiated alkalic basalt and hawaiite clasts in a phosphatized carbonate matrix. The degree of mass wasting on the slopes of these seamounts is inversely correlated with the thickness of crusts. Crusts are generally thin on limestone substrate. Away from areas of active mass-wasting processes, and large atolls, crusts may be as thick as 10 cm maximum. The dominant crystalline phase in the Marshall Islands crusts is ??-MnO2 (vernadite). High concentrations of cobalt, platinum and rhodium strongly suggest that the Marshall Islands crusts are a viable source for these important metals. Many metals and the rare earth elements vary significantly on a fine scale through most crusts, thus reflecting the abundances of different host mineral phases in the crusts and changes in seawater composition with time. High concentrations of cobalt, nickel, titanium, zinc, lead, cerium and platinum result from a combination of their substitution in the iron and manganese phases and their oxidation potential. ?? 1988.

Researching Pacific island livelihoods:

DEFF Research Database (Denmark)

Egelund Christensen, Andreas; Mertz, Ole

2010-01-01

on contemporary theories of nissology and conceptual analytical frameworks for island research. Through a review of selected case-study-based island literature on changing livelihoods coming out of the South Pacific, we wish to illustrate and discuss advantages of finding common grounds for small island studies....... The focus is on two dimensions of island livelihood, migration and natural resource management, both of which are significant contributors in making island livelihoods and shaping Pacific seascapes. We argue that there is still a substantial lack of studies targeting small island dynamics that are empirical...

A study of the river basins and limnology of five humic lakes on Chiloé Island Estudio de la cuenca y limnología en cinco lagos húmicos de la Isla Chiloé

Directory of Open Access Journals (Sweden)

L. VILLALOBOS

2003-12-01

Full Text Available From November 1996 to October 1997, the river basins of five humic lakes on Chiloé Island were studied monthly: Lakes Natri, Tepuhueico, Tarahuín, Huillinco and Cucao. The objective of this study was to know the catchment area, river basin and the main physical, chemical and biological characteristics of these humic lakes. The trophic status, the actual loading, and the mass balances of phosphorus and nitrogen were determined in relation to anthropogenic activities. Lakes Cucao and Huillinco were characterized by a marine influence. All the lakes had brown coloured waters, caused by humic substances, which limit their transparency. Lake Natri was the deepest (58 m, whereas Lake Tepuhueico had the shallowest depth (25 m. Total phosphorus and nitrogen fluctuated between 23.5 and 35 µg L-1 and 197 and 380 mug L-1 (annual average in lakes Natri, Tepuhueico and Tarahuín, respectively. Lakes Cucao and Huillinco showed extremely high concentrations of total nitrogen (annual average or = 3,000 mug L-1 and total phosphorus (= 223 and 497 mug L-1, and were classified as hyper-eutrophic. Lake Tarahuín registered the greatest diversity of phytoplankton, with 55 species, including Ceratium hirundinella which also occurred in lakes Cucao and Tarahuín. The diversity of the zooplankton community varied across these lakes. The presence of Diaptomus diabolicus (Tumeodiaptomus d. Dussart 1979 (Cucao, Huillinco and Tepuhueico is noteworthy since this extends its geographical distribution to the south

78 FR 63860 - Amendment of Class D Airspace; Kwajalein Island, Marshall Islands, RMI

Science.gov (United States)

2013-10-25

...This action amends the Kwajalein Island Class D airspace description by amending the geographic coordinates for Bucholz Army Airfield (AAF), Kwajalein Island, Marshall Islands, RMI. The Bucholz AAF geographic coordinates information was updated in the Kwajalein Island Class E airspace descriptions in 2011, but was inadvertently overlooked in the Kwajalein Island Class D airspace description. This action ensures the safety of aircraft operating in the Kwajalein Island airspace area. This is an administrative action and does not affect the operating requirements of the airspace.

Stepping-stones to the Edge: Artistic Expressions of Islandness in an Ocean of Islands

Directory of Open Access Journals (Sweden)

Laurie Brinklow

2013-05-01

Full Text Available Since the earliest of times, islands have captured the artistic imagination—and, often, for the artist who finds his or her muse in being ‘islanded’, the smaller the island the better. Archipelagos offer an ideal setting for artists who take their inspiration from place: on small islands off islands they can experience an intensity of island living they might not otherwise have on a main island: boundedness and connection, isolation and community. This paper examines expressions of islandness by artists who live on islands off islands that are poles apart—‘archipelagos’ of the Canadian North Atlantic and the Great Southern Ocean. It draws upon interviews with those artists and writers to consider the nature of humans’ attachment and attraction to islands, exploring through the lens of phenomenology what Stratford et al. call the “entanglement between and among islands”.

Modeling the distribution of Norway rats (Rattus norvegicus on offshore islands in the Falkland Islands

Directory of Open Access Journals (Sweden)

Michael A. Tabak

2015-01-01

Full Text Available Non-native rats (Rattus spp. threaten native island species worldwide. Efforts to eradicate them from islands have increased in frequency and become more ambitious in recent years. However, the long-term success of some eradication efforts has been compromised by the ability of rats, particularly Norway rats (Rattus norvegicus which are good swimmers, to recolonize islands following eradications. In the Falkland Islands, an archipelago in the South Atlantic Ocean, the distance of 250 m between islands (once suggested as the minimum separation distance for an effective barrier to recolonization has shown to be insufficient. Norway rats are present on about half of the 503 islands in the Falklands. Bird diversity is lower on islands with rats and two vulnerable passerine species, Troglodytes cobbi (the only endemic Falkland Islands passerine and Cinclodes antarcticus, have greatly reduced abundances and/or are absent on islands with rats. We used logistic regression models to investigate the potential factors that may determine the presence of Norway rats on 158 islands in the Falkland Islands. Our models included island area, distance to the nearest rat-infested island, island location, and the history of island use by humans as driving variables. Models best supported by data included only distance to the nearest potential source of rats and island area, but the relative magnitude of the effect of distance and area on the presence of rats varied depending on whether islands were in the eastern or western sector of the archipelago. The human use of an island was not a significant parameter in any models. A very large fraction (72% of islands within 500 m of the nearest potential rat source had rats, but 97% of islands farther than 1,000 m away from potential rat sources were free of rats.

33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

Science.gov (United States)

2010-07-01

... Island. (j) An east-west line from the southernmost extremity of Sea Island across Goulds Inlet to St... Tybee Island 255° true across Tybee Inlet to the shore of Little Tybee Island south of the entrance to... shoreline across Cabretta Inlet. (g) A north-south line (longitude 81°16.9′ W.) drawn from the south...

Energy Transition Initiative: Island Energy Snapshot - U.S. Virgin Islands (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2015-03-01

This profile provides a snapshot of the energy landscape of the U.S. Virgin Islands (USVI) - St. Thomas, St. John, and St. Croix. The Virgin Islands archipelago makes up the northern portion of the Lesser Antilles and the western island group of the Leeward Islands, forming the border between the Atlantic Ocean and the Caribbean Sea.

Socioeconomic dimensions of changes in the agricultural landscape of the Mediterranean basin: a case study of the abandonment of cultivation terraces on Nisyros Island, Greece.

Science.gov (United States)

Petanidou, Theodora; Kizos, Thanasis; Soulakellis, Nikolaos

2008-02-01

Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published literature, as well as surveys of the islanders. Population increases during the late 19th to early 20th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4% of the island. By the mid-20th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes) and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including those on other islands in this region. The island's unique terraced landscapes may qualify Nisyros to become an archive or repository of old agricultural management techniques to be used by future generations and a living resource for sustainable management.

National Uranium Resource Evaluation: Providence Quadrangle, Connecticut, Rhode Island, and Massachusetts

International Nuclear Information System (INIS)

Zollinger, R.C.; Blauvelt, R.P.; Chew, R.T. III.

1982-09-01

The Providence Quadrangle, Connecticut, Rhode Island, and Massachusetts, was evaluated to a depth of 1500 m to identify environments and delineate areas favorable for uranium deposits. Criteria for this evaluation were developed by the National Uranium Resource Evaluation program. Environments were recognized after literature research, surface and subsurface geologic reconnaissance, and examination of known uranium occurrences and aeroradioactivity anomalies. Environments favorable for authigenic uranium deposits were found in the Quincy and Cowesett Granites. An environment favorable for contact-metasomatic deposits is in and around the borders of the Narragansett Pier Granite where it intrudes the Pennsylvanian sediments of the Narragansett Basin. An environment favorable for authigenic deposits in metamorphic rocks is in a migmatite on the eastern edge of the Scituate Granite Gneiss batholith. Environments favorable for contact-metasomatic deposits occur at the contacts between many of the granitic rocks and metamorphic rocks of the Blackstone Series. Results of this study also indicate environments favorable for sandstone-type uranium deposits are present in the rocks of the Narragansett Basin. Environments unfavorable for uranium deposits in the quadrangle include all granites not classified as favorable and the metamorphic rocks of eastern Connecticut. Glacial deposits and Cretaceous-Tertiary sediments remain unevaluated

The Central European Permian Basins; Rheological and structural controls on basin history and on inter-basin connectivity

NARCIS (Netherlands)

Smit, Jeroen; van Wees, Jan-Diederik; Cloetingh, Sierd

2014-01-01

We analyse the relative importance of the major crustal-scale fault zones and crustal architecture in controlling basin formation, deformation and the structural connections between basins. The North and South Permian Basins of Central Europe are usually defined by the extend of Rotliegend

Magmatic dyke swarms of the south shetland islands volcanic arc, west-antarctica - tracers of geodynamic history

Science.gov (United States)

Kraus, St.; Miller, H.

2003-04-01

Magmatic dykes are essential components of volcanic arcs, following joint systems and fracture zones. This work aims to reconstruct the deformational and intrusive history of the northern part of the Antarctic Peninsula by combining structural information with the geochemistry, isotopy and age of the dykes. On the South Shetland Islands volcanic activity began about 130 Ma ago. From Mid to Late Eocene (49-34 Ma) the northern Antarctic Peninsula and southern South America underwent extensional tectonics, which led to sea-floor spreading in the Drake Passage 28 Ma ago. Subsequent slab-rollback caused arc-extension and the opening of the Bransfield Rift as a backarc-basin between 4 and 1.3 Ma ago. Very slow subduction (1mm/a) at the South Shetland trench continues until the present day. Several changes of subduction direction caused crucial variations regarding the tectonic regime in the overlying South Shetland block, being the reason for the shifting strike of the dykes. Several dyke systems were mapped in areas of up to 100000m2, with the outcrop situation being good enough to observe plenty of relative age relationships. ICP-MS geochemical analysis on 132 dykes shows, as expected, that the majority of them correspond to a typical subduction-related calcalcalic suite, ranging from basalts to rhyolites. Nevertheless, some dykes show shoshonitic characteristics and are maybe related to an early stage extensional crustal regime. This is supported by the relative ages observed in the field, indicating, that these dykes belong to the oldest ones outcropping in the investigated area. In one case, the geochemical behaviour of the dyke corresponds clearly to adacitic conditions, being a hint on partially molten subducted oceanic crust. In several areas (e.g. Potter Peninsula, King George Island, and Hurd Peninsula, Livingston Island) a strong correlation between chemism and strike of the dykes - and therefore the tectonic regime at the time of intrusion - is observed. Ce

Comparative Research on River Basin Management in the Sagami River Basin (Japan and the Muda River Basin (Malaysia

Directory of Open Access Journals (Sweden)

Lay Mei Sim

2018-05-01

Full Text Available In the world, river basins often interwoven into two or more states or prefectures and because of that, disputes over water are common. Nevertheless, not all shared river basins are associated with water conflicts. Rivers in Japan and Malaysia play a significant role in regional economic development. They also play a significant role as water sources for industrial, domestic, agricultural, aquaculture, hydroelectric power generation, and the environment. The research aim is to determine the similarities and differences between the Sagami and Muda River Basins in order to have a better understanding of the governance needed for effectively implementing the lessons drawn from the Sagami River Basin for improving the management of the Muda River Basin in Malaysia. This research adopts qualitative and quantitative approaches. Semi-structured interviews were held with the key stakeholders from both basins and show that Japan has endeavored to present policy efforts to accommodate the innovative approaches in the management of their water resources, including the establishment of a river basin council. In Malaysia, there is little or no stakeholder involvement in the Muda River Basin, and the water resource management is not holistic and is not integrated as it should be. Besides that, there is little or no Integrated Resources Water Management, a pre-requisite for sustainable water resources. The results from this comparative study concluded that full support and participation from public stakeholders (meaning the non-government and non-private sector stakeholders is vital for achieving sustainable water use in the Muda River Basin. Integrated Water Resources Management (IWRM approaches such as the introduction of payments for ecosystems services and the development of river basin organization in the Muda River Basin should take place in the spirit of political willingness.

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Folly Island, SC to Hilton Head Island, SC. 7.70 Section... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...′ W. (Port Royal Sound Lighted Whistle Buoy “2PR”); thence to the easternmost extremity of Hilton Head...

Application of Adjoint Method and Spectral-Element Method to Tomographic Inversion of Regional Seismological Structure Beneath Japanese Islands

Science.gov (United States)

Tsuboi, S.; Miyoshi, T.; Obayashi, M.; Tono, Y.; Ando, K.

2014-12-01

Recent progress in large scale computing by using waveform modeling technique and high performance computing facility has demonstrated possibilities to perform full-waveform inversion of three dimensional (3D) seismological structure inside the Earth. We apply the adjoint method (Liu and Tromp, 2006) to obtain 3D structure beneath Japanese Islands. First we implemented Spectral-Element Method to K-computer in Kobe, Japan. We have optimized SPECFEM3D_GLOBE (Komatitsch and Tromp, 2002) by using OpenMP so that the code fits hybrid architecture of K-computer. Now we could use 82,134 nodes of K-computer (657,072 cores) to compute synthetic waveform with about 1 sec accuracy for realistic 3D Earth model and its performance was 1.2 PFLOPS. We use this optimized SPECFEM3D_GLOBE code and take one chunk around Japanese Islands from global mesh and compute synthetic seismograms with accuracy of about 10 second. We use GAP-P2 mantle tomography model (Obayashi et al., 2009) as an initial 3D model and use as many broadband seismic stations available in this region as possible to perform inversion. We then use the time windows for body waves and surface waves to compute adjoint sources and calculate adjoint kernels for seismic structure. We have performed several iteration and obtained improved 3D structure beneath Japanese Islands. The result demonstrates that waveform misfits between observed and theoretical seismograms improves as the iteration proceeds. We now prepare to use much shorter period in our synthetic waveform computation and try to obtain seismic structure for basin scale model, such as Kanto basin, where there are dense seismic network and high seismic activity. Acknowledgements: This research was partly supported by MEXT Strategic Program for Innovative Research. We used F-net seismograms of the National Research Institute for Earth Science and Disaster Prevention.

Determination of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios in Brown Algae (Fucus distichus) Collected from Amchitka Island, Alaska

International Nuclear Information System (INIS)

Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

2005-01-01

Plutonium-239 ( 239 Pu) and plutonium-240 ( 240 Pu) activity concentrations and 240 Pu/ 239 Pu atom ratios are reported for Brown Algae (Fucus distichus) collected from the littoral zone of Amchitka Island (Alaska) and at a control site on the Alaskan peninsula. Plutonium isotope measurements were performed in replicate using Accelerator Mass Spectrometry (AMS). The average 240 Pu/ 239 Pu atom ratio observed in dried Fucus d. collected from Amchitka Island was 0.227 ± 0.007 (n=5) and compares with the expected 240 Pu/ 239 Pu atom ratio in integrated worldwide fallout deposition in the Northern Hemisphere of 0.1805 ± 0.0057 (Cooper et al., 2000). In general, the characteristically high 240 Pu/ 239 Pu content of Fucus d. analyzed in this study appear to indicate the presence of a discernible basin-wide secondary source of plutonium entering the marine environment. Of interest to the study of plutonium source terms within the Pacific basin are reports of elevated 240 Pu/ 239 Pu atom ratios in fallout debris from high-yield atmospheric nuclear tests conducted in the Marshall Islands during the 1950s (Diamond et al., 1960), the wide range of 240 Pu/ 239 Pu atom ratio values (0.19 to 0.34) observed in sea water, sediments, coral and other environmental media from the North Pacific Ocean (Hirose et al., 1992; Buesseler, 1997) and updated estimates of the relative contributions of close-in and intermediate fallout deposition on oceanic inventories of radionuclidies, especially in the Northern Pacific Ocean (Hamilton, 2004)

Tracing the temporal and spatial origins of island endemics in the Mediterranean region: a case study from the citrus family (Ruta L., Rutaceae).

Science.gov (United States)

Salvo, Gabriele; Ho, Simon Y W; Rosenbaum, Gideon; Ree, Richard; Conti, Elena

2010-12-01

Understanding the origin of island endemics is a central task of historical biogeography. Recent methodological advances provide a rigorous framework to determine the relative contribution of different biogeographic processes (e.g., vicariance, land migration, long-distance dispersal) to the origin of island endemics. With its complex but well-known history of microplate movements and climatic oscillations, the Mediterranean region (including the Mediterranean basin and Macaronesia) provides the geographic backdrop for the diversification of Ruta L., the type genus of Rutaceae (citrus family). Phylogenetic, molecular dating, and ancestral range reconstruction analyses were carried out to investigate the extent to which past geological connections and climatic history of the Mediterranean region explain the current distribution of species in Ruta, with emphasis on its island endemics. The analyses showed that Ruta invaded the region from the north well before the onset of the Mediterranean climate and diversified in situ as the climate became Mediterranean. The continental fragment island endemics of the genus originated via processes of land migration/vicariance driven by connections/disconnections between microplates, whereas the oceanic island endemics were the product of a single colonization event from the mainland followed by in situ diversification. This study emphasizes the need for an integrative, hypothesis-based approach to historical biogeography and stresses the importance of temporary land connections and colonization opportunity in the biotic assembly of continental fragment and oceanic islands, respectively.

Middle to Late Devonian–Carboniferous collapse basins on the Finnmark Platform and in the southwesternmost Nordkapp basin, SW Barents Sea

Directory of Open Access Journals (Sweden)

J.-B. P. Koehl

2018-03-01

Full Text Available The SW Barents Sea margin experienced a pulse of extensional deformation in the Middle–Late Devonian through the Carboniferous, after the Caledonian Orogeny terminated. These events marked the initial stages of formation of major offshore basins such as the Hammerfest and Nordkapp basins. We mapped and analyzed three major fault complexes, (i the Måsøy Fault Complex, (ii the Rolvsøya fault, and (iii the Troms–Finnmark Fault Complex. We discuss the formation of the Måsøy Fault Complex as a possible extensional splay of an overall NE–SW-trending, NW-dipping, basement-seated Caledonian shear zone, the Sørøya–Ingøya shear zone, which was partly inverted during the collapse of the Caledonides and accommodated top–NW normal displacement in Middle to Late Devonian–Carboniferous times. The Troms–Finnmark Fault Complex displays a zigzag-shaped pattern of NNE–SSW- and ENE–WSW-trending extensional faults before it terminates to the north as a WNW–ESE-trending, NE-dipping normal fault that separates the southwesternmost Nordkapp basin in the northeast from the western Finnmark Platform and the Gjesvær Low in the southwest. The WNW–ESE-trending, margin-oblique segment of the Troms–Finnmark Fault Complex is considered to represent the offshore prolongation of a major Neoproterozoic fault complex, the Trollfjorden–Komagelva Fault Zone, which is made of WNW–ESE-trending, subvertical faults that crop out on the island of Magerøya in NW Finnmark. Our results suggest that the Trollfjorden–Komagelva Fault Zone dies out to the northwest before reaching the western Finnmark Platform. We propose an alternative model for the origin of the WNW–ESE-trending segment of the Troms–Finnmark Fault Complex as a possible hard-linked, accommodation cross fault that developed along the Sørøy–Ingøya shear zone. This brittle fault decoupled the western Finnmark Platform from the southwesternmost Nordkapp basin and merged with the

Drainage basins features and hydrological behaviour river Minateda basin

International Nuclear Information System (INIS)

Alonso-Sarria, F.

1991-01-01

Nine basin variables (shape, size and topology) have been analyzed in four small basins with non-permanent run off (SE of Spain). These geomorphological variables have been selected for their high correlation with the Instantaneous unit hydrograph parameters. It is shown that the variables can change from one small basin to another within a very short area; because of it, generalizations about the behaviour of the run off are not possible. In conclusion, it is stated that the variations in geomorphological aspects between different basins, caused mainly by geological constraints, are a very important factor to be controlled in a study of geoecological change derived from climatic change

RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

Energy Technology Data Exchange (ETDEWEB)

Robert Caldwell

1998-04-01

Vast quantities of natural gas are entrapped within various tight formations in the Rocky Mountain area. This report seeks to quantify what proportion of that resource can be considered recoverable under today's technological and economic conditions and discusses factors controlling recovery. The ultimate goal of this project is to encourage development of tight gas reserves by industry through reducing the technical and economic risks of locating, drilling and completing commercial tight gas wells. This report is the fourth in a series and focuses on the Wind River Basin located in west central Wyoming. The first three reports presented analyses of the tight gas reserves and resources in the Greater Green River Basin (Scotia, 1993), Piceance Basin (Scotia, 1995) and the Uinta Basin (Scotia, 1995). Since each report is a stand-alone document, duplication of language will exist where common aspects are discussed. This study, and the previous three, describe basin-centered gas deposits (Masters, 1979) which contain vast quantities of natural gas entrapped in low permeability (tight), overpressured sandstones occupying a central basin location. Such deposits are generally continuous and are not conventionally trapped by a structural or stratigraphic seal. Rather, the tight character of the reservoirs prevents rapid migration of the gas, and where rates of gas generation exceed rates of escape, an overpressured basin-centered gas deposit results (Spencer, 1987). Since the temperature is a primary controlling factor for the onset and rate of gas generation, these deposits exist in the deeper, central parts of a basin where temperatures generally exceed 200 F and drill depths exceed 8,000 feet. The abbreviation OPT (overpressured tight) is used when referring to sandstone reservoirs that comprise the basin-centered gas deposit. Because the gas resources trapped in this setting are so large, they represent an important source of future gas supply, prompting studies

Secondhand smoke concentrations in hospitality venues in the Pacific Basin: findings from American Samoa, Commonwealth of the Northern Mariana Islands, and Guam.

Science.gov (United States)

King, Brian A; Dube, Shanta R; Ko, Jean Y

2011-01-01

Secondhand smoke (SHS) from burning tobacco products causes disease and premature death among nonsmokers. Although the number of laws prohibiting smoking in indoor public places continues to increase, millions of nonsmokers in the United States (US) and its territories remain exposed to SHS. This study assessed indoor air pollution from SHS in hospitality venues in three US Pacific Basin territories. Air monitors were used to assess PM2.5, an environmental marker for SHS, in 19 smoke-permitted and 18 smoke- free bars and restaurants in American Samoa, Commonwealth of the Northern Mariana Islands (CNMI), and Guam. Observational logs were used to record smoking and other sources of air pollution. Differences in average PM2.5 concentrations were determined using bivariate statistics. The average PM2.5 level in venues where smoking was always permitted [arithmetic mean (AM)=299.98 μg/m3; geometric mean (GM)=200.39 μg/ m3] was significantly higher (p<0.001) than smoke-free venues [AM=8.33 μg/m3; GM=6.14 μg/m3]. In venues where smoking was allowed only during certain times, the average level outside these times [AM=42.10 μg/m3; GM=41.87 μg/m3] was also significantly higher (p<0.001) than smoke-free venues. Employees and patrons of smoke-permitted bars and restaurants are exposed to dangerous levels of air pollution from SHS, even during periods when active smoking is not occurring. Prohibiting smoking in all public indoor areas, irrespective of the venue type or time of day, is the only way to fully protect nonsmokers from SHS exposure in these environments.

New insights into the stratigraphic, paleogeographic and tectonic evolution and petroleum potential of Kerkennah Islands, Eastern Tunisia

Science.gov (United States)

Elfessi, Maroua

2017-01-01

This work presents general insights into the stratigraphic and paleogeographic evolution as well as the structural architecture and the petroleum potential of Kerkennah Islands, located in the Eastern Tunisia Foreland, from Cenomanian to Pliocene times. Available data from twenty wells mostly drilled in Cercina and Chergui fields are used to establish three lithostratigraphic correlations as well as isopach and isobath maps in order to point out thickness and depth variations of different geological formations present within our study area; in addition to a synthetic log and isoporosity map of the main carbonate reservoir (the nummulites enriched Reineche Member). The integrated geological study reveals relatively condensed but generally continuous sedimentation and a rugged substrate with horsts, grabens and tilted blocks due to the initiation and the individualization of Kerkennah arch throughout the studied geological times. Furthermore, a relationship was highlighted between the evolution of our study zone and those of Sirt basin, Western Mediterranean Sea and Pelagian troughs; this relationship is due to the outstanding location of Kerkennah Islands. The main Bou Dabbous source rock is thicker and more mature within the central-east of the Gulf of Gabes indicating therefore the southeast charge of Reineche reservoir which shows NW-SE trending tilted block system surrounded by normal faults representing the hydrocarbon migration pathways. Besides, the thick Oligo-Miocene formations deposited during the collapse of the Pelagian block caused the maturation of the Ypresian source rock, while the Pliocene unconformity allowed basin inversion and hydrocarbon migration.

Reconstructing multiple arc-basin systems in the Altai-Junggar area (NW China): Implications for the architecture and evolution of the western Central Asian Orogenic Belt

Science.gov (United States)

Li, Di; He, Dengfa; Tang, Yong

2016-05-01

.5-8.5) and εHf(t) (10.2-16.8) values, as well as young isotopic model ages. These Devonian-Carboniferous intermediate-felsic volcanics are interpreted as the products of partial melting of a juvenile lower crust with some contributions from mantle components in an evolved island arc setting from immature to mature island arc. The basin filling pattern and the distribution of arc volcanics and their zircon Hf model ages with the eruptive time suggest that the Wulungu Depression represents an island arc-basin system with the development of a Carboniferous retro-arc basin. In combination with previous work, we propose that the northern Junggar area comprises three arc-basin belts from south to north: the Darbut-Luliang-Karamaili, Wulungu-Yemaquan, and Saur-Fuhai-Dulate. Such tectonic subdivisions are consistent with the regional gravity and magnetic anomaly data. The recognition of the Wulungu arc-basin system demonstrates that the Junggar Basin is likely underlain by juvenile continental crust rather than ancient Precambrian basement, and also implies that the CAOB was built by amalgamation of multiple linear arcs and accretionary complexes.

Rhode Island unemployment

OpenAIRE

Leonard Lardaro

2010-01-01

How can a state like Rhode Island have such a high unemployment rate? This question has been asked often over the past year, especially since at one point, Rhode Island found itself with the dubious distinction of having the highest unemployment rate in the United States. Following that extreme, Rhode Island seemed to settle into a niche where its rank was third nationally.

Coastal management strategy for small island: ecotourism potency development in Karimata Island, West Kalimantan

Science.gov (United States)

Rudiastuti, A. W.; Munawaroh; Setyawan, I. E.; Pramono, G. H.

2018-04-01

Sustainable coastal management is playing an important role in coastal resources conservation, particularly on small islands. Karimata archipelago has unique characteristics and great potential to be developed as a tourism object, one of which is Karimata Island as the largest island and also reserve area. The concept of ecotourism focuses on the ecology conservation, economic benefits, and social life. Ecotourism aims to build sustainable tourism that provides economically viable and social benefits to the community. This study aims to develop coastal management strategy based on ecotourism at Karimata Island. Spatial approaching through coastal type was done. Qualitative descriptive analysis and SWOT are used to develop sustainable management strategies for the coast of Karimata Island, where the opportunities and challenges to the development of coastal ecotourism Karimata Island also included. If this potential is optimally utilized, it can be relied as an economic opportunity for local communities. Structurally shaped coast, marine depositional coast and coast build by organism are several of coastal types found at Karimata Island. Coastal ecosystems inhabited Karimata Island are mangroves, coral reefs, and macro-algae. Karimata Island have not been optimally utilized for tourist destinations. The biggest obstacle encountered is the accessibility from Kalimantan or other island at Karimata islands. Several problems related to the utilization of coastal resources were found such as mangrove and coral reef damage, also regulation that less supportive. The results of this study are expected to provide an overview of solutions for the development of coastal tourism potentials in Karimata Island.

Socioeconomic Dimensions of Changes in the Agricultural Landscape of the Mediterranean Basin: A Case Study of the Abandonment of Cultivation Terraces on Nisyros Island, Greece

Science.gov (United States)

Petanidou, Theodora; Kizos, Thanasis; Soulakellis, Nikolaos

2008-02-01

Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published literature, as well as surveys of the islanders. Population increases during the late 19th to early 20th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4% of the island. By the mid-20th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes) and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including those on other islands in this region. The island’s unique terraced landscapes may qualify Nisyros to become an archive or repository of old agricultural management techniques to be used by future generations and a living resource for sustainable management.

Self-sustained magnetic islands

Energy Technology Data Exchange (ETDEWEB)

Chatenet, J H; Luciani, J F [Ecole Polytechnique, 91 - Palaiseau (France); Garbet, X [Association Euratom-CEA, Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

1996-06-01

Numerical simulations of a single magnetic island evolution are presented in the regime where the island width is smaller than an ion Larmor radius. It is shown that the island rotation is controlled by particle diffusion due to collisions or a background of microturbulence. As expected from the theory of a stationary island, there exist cases where linearly stable magnetic perturbation are nonlinearly self-sustained. This situation corresponds to large poloidal beta and temperature gradient. The drive is due to diamagnetic frequency effects. However, this situation is not generic, and islands can also decay. It is found that a magnetic island is self-sustained for a negative off-diagonal diffusion coefficient. This case occurs in a tokamak if the inward particle pinch is due to the temperature gradient. (author). 30 refs.

Self-sustained magnetic islands

International Nuclear Information System (INIS)

Chatenet, J.H.; Luciani, J.F.; Garbet, X.

1996-06-01

Numerical simulations of a single magnetic island evolution are presented in the regime where the island width is smaller than an ion Larmor radius. It is shown that the island rotation is controlled by particle diffusion due to collisions or a background of microturbulence. As expected from the theory of a stationary island, there exist cases where linearly stable magnetic perturbation are nonlinearly self-sustained. This situation corresponds to large poloidal beta and temperature gradient. The drive is due to diamagnetic frequency effects. However, this situation is not generic, and islands can also decay. It is found that a magnetic island is self-sustained for a negative off-diagonal diffusion coefficient. This case occurs in a tokamak if the inward particle pinch is due to the temperature gradient. (author)

Contrasting basin architecture and rifting style of the Vøring Basin, offshore mid-Norway and the Faroe-Shetland Basin, offshore United Kingdom

Science.gov (United States)

Schöpfer, Kateřina; Hinsch, Ralph

2017-04-01

The Vøring and the Faroe-Shetland basins are offshore deep sedimentary basins which are situated on the outer continental margin of the northeast Atlantic Ocean. Both basins are underlain by thinned continental crust whose structure is still debated. In particular the nature of the lower continental crust and the origin of high velocity bodies located at the base of the lower crust are a subject of discussion in recent literature. Regional interpretation of 2D and 3D seismic reflection data, combined with well data, suggest that both basins share several common features: (i) Pre-Cretaceous faults that are distributed across the entire basin width. (ii) Geometries of pre-Jurassic strata reflecting at least two extensional phases. (iii) Three common rift phases, Late Jurassic, Campanian-Maastrichtian and Palaeocene. (iv) Large pre-Cretaceous fault blocks that are buried by several kilometres of Cretaceous and Cenozoic strata. (iii). (v) Latest Cretaceous/Palaeocene inversion. (vi) Occurrence of partial mantle serpentinization during Early Cretaceous times, as proposed by other studies, seems improbable. The detailed analysis of the data, however, revealed significant differences between the two basins: (i) The Faroe-Shetland Basin was a fault-controlled basin during the Late Jurassic but also the Late Cretaceous extensional phase. In contrast, the Vøring Basin is dominated by the late Jurassic rifting and subsequent thermal subsidence. It exhibits only minor Late Cretaceous faults that are localised above intra-basinal and marginal highs. In addition, the Cretaceous strata in the Vøring Basin are folded. (ii) In the Vøring Basin, the locus of Late Cretaceous rifting shifted westwards, affecting mainly the western basin margin, whereas in the Faroe-Shetland Basin Late Cretaceous rifting was localised in the same area as the Late Jurassic phase, hence masking the original Jurassic geometries. (iii) Devono-Carboniferous and Aptian/Albian to Cenomanian rift phases

Reliving Island Life: Staging Stories of the Blasket Islands

Directory of Open Access Journals (Sweden)

Daithí Kearney

2017-10-01

Full Text Available The Blasket Islands are located off the south-west coast of Ireland. No longer inhabited, the Great Blasket Island and its distinctive culture have been documented by a variety of writers and are celebrated today in an interpretative centre on the mainland and in performances by Siamsa Tíre, The National Folk Theatre of Ireland. “Siamsa” developed from local initiatives in North Kerry during the early 1960s and is located today in Tralee, Co. Kerry. It aims to present Irish folklore and folk culture through the medium of theatre involving music, song, dance and mime but invariably no dialogue. In this paper, I focus on the production Oiléan, based loosely on the stories of the Blasket Islanders, which was initially devised as part of the fiftieth anniversary commemoration of the departure of the last inhabitants of the islands in 2003.

46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false St. Simons Island, GA to Little Talbot Island, FL. 7.85... BOUNDARY LINES Atlantic Coast § 7.85 St. Simons Island, GA to Little Talbot Island, FL. (a) A line drawn from latitude 31°04.1′ N. longitude 81°16.7′ W. (St. Simons Lighted Whistle Buoy “ST S”) to latitude 30...

Adaptive radiation of island plants: Evidence from Aeonium (Crassulaceae) of the Canary Islands

DEFF Research Database (Denmark)

Jorgensen, T.H.; Olesen, J.M.

2001-01-01

evidence that such traits have been acquired through convergent evolution on islands comes from molecular phylogenies; however, direct evidence of their selective value rarely is obtained. The importance of hybridization in the evolution of island plants is also considered as part of a more general......The presence of diverse and species-rich plant lineages on oceanic islands is most often associated with adaptive radiation. Here we discuss the possible adaptive significance of some of the most prominent traits in island plants, including woodiness, monocarpy and sexual dimorphisms. Indirect...... discussion of the mechanisms governing radiations on islands. Most examples are from the Hawaiian and Canarian floras, and in particular from studies on the morphological, ecological and molecular diversification of the genus Aeonium, the largest plant radiation of the Canarian Islands....

Physical Modeling of Tsunamis Generated By 3D Deformable Landslides in Various Scenarios From Fjords to Conical Islands

Science.gov (United States)

McFall, B. C.; Fritz, H. M.

2013-12-01

Tsunamis generated by landslides and volcano flank collapse can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. Two different materials are used to simulate landslides to study the granulometry effects: naturally rounded river gravel and cobble mixtures. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 basin-wide propagation and runup, fjord, curved headland fjord and a conical island setting representing a landslide off an island or a volcano flank collapse. Water surface elevations are recorded by an array of resistance wave gauges. The landslide deformation is measured from above and underwater camera recordings. The landslide deposit is measured on the basin floor with a multiple transducer acoustic array (MTA). Landslide surface reconstruction and kinematics are determined with a stereo particle image velocimetry (PIV) system. Wave runup is recorded with resistance wave gauges along the slope and verified with video image processing. The measured landslide and wave parameters are

Heron Island, Australia

Science.gov (United States)

2002-01-01

Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

Formation and adjustment of typhoon-impacted reef islands interpreted from remote imagery: Nadikdik Atoll, Marshall Islands

Science.gov (United States)

Ford, Murray R.; Kench, Paul S.

2014-06-01

In 1905, a devastating typhoon hit Nadikdik Atoll (5°54‧ N and 172°09‧ E) in the southern Marshall Islands. Evidence suggests that large sections of reef islands on Nadikdik were overwashed and destroyed. Comparison of aerial photographs taken in 1945 and modern satellite imagery provides a unique record of the geomorphic adjustment of islands after the typhoon. Between 1945 and 2010 the vegetated area of islands on Nadikdik grew from 0.74 to 0.90 km2. Observed changes to Nadikdik reef islands manifested through a range of styles and were largely accretionary. Of note, the formation of a new island was tracked from an embryonic deposit to a fully vegetated and stable island over a 61 year period. Similarly, a number of previously discrete islands have agglomerated and formed a single larger island. These changes were rapid and indicate that reef island formation can occur quickly. Evidence suggests that despite the typhoon occurring over a century ago the geomorphic adjustment of islands is still on-going.

Evaluating prediction uncertainty of areas contributing recharge to well fields of multiple water suppliers in the Hunt-Annaquatucket-Pettaquamscutt River Basins, Rhode Island

Science.gov (United States)

Friesz, Paul J.

2012-01-01

Three river basins in central Rhode Island-the Hunt River, the Annaquatucket River, and the Pettaquamscutt River-contain 15 production wells clustered in 4 pumping centers from which drinking water is withdrawn. These high-capacity production wells, operated by three water suppliers, are screened in coarse-grained deposits of glacial origin. The risk of contaminating water withdrawn by these well centers may be reduced if the areas contributing recharge to the well centers are delineated and these areas protected from land uses that may affect the water quality. The U.S. Geological Survey, in cooperation with the Rhode Island Department of Health, began an investigation in 2009 to improve the understanding of groundwater flow and delineate areas contributing recharge to the well centers as part of an effort to protect the source of water to these well centers. A groundwater-flow model was calibrated by inverse modeling using nonlinear regression to obtain the optimal set of parameter values, which provide a single, best representation of the area contributing recharge to a well center. Summary statistics from the calibrated model were used to evaluate the uncertainty associated with the predicted areas contributing recharge to the well centers. This uncertainty analysis was done so that the contributing areas to the well centers would not be underestimated, thereby leaving the well centers inadequately protected. The analysis led to contributing areas expressed as a probability distribution (probabilistic contributing areas) that differ from a single or deterministic contributing area. Groundwater flow was simulated in the surficial deposits and the underlying bedrock in the 47-square-mile study area. Observations (165 groundwater levels and 7 base flows) provided sufficient information to estimate parameters representing recharge and horizontal hydraulic conductivity of the glacial deposits and hydraulic conductance of streambeds. The calibrated value for recharge

Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California

Science.gov (United States)

Muhs, D.R.; Budahn, J.R.; Johnson, D.L.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.; Jones, J.A.

2008-01-01

There is an increasing awareness that dust plays important roles in climate change, biogeochemical cycles, nutrient supply to ecosystems, and soil formation. In Channel Islands National Park, California, soils are clay-rich Vertisols or Alfisols and Mollisols with vertic properties. The soils are overlain by silt-rich mantles that contrast sharply with the underlying clay-rich horizons. Silt mantles contain minerals that are rare or absent in the volcanic rocks that dominate these islands. Immobile trace elements (Sc-Th-La and Ta-Nd-Cr) and rare-earth elements show that the basalt and andesite on the islands have a composition intermediate between upper-continental crust and oceanic crust. In contrast, the silt fractions and, to a lesser extent, clay fractions of the silt mantle have compositions closer to average upper-continental crust and very similar to Mojave Desert dust. Island shelves, exposed during the last glacial period, could have provided a source of eolian sediment for the silt mantles, but this is not supported by mineralogical data. We hypothesize that a more likely source for the silt-rich mantles is airborne dust from mainland California and Baja California, either from the Mojave Desert or from the continental shelf during glacial low stands of sea. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. The eolian silt mantles constitute an important medium of plant growth and provide evidence that abundant eolian silt and clay may be delivered to the eastern Pacific Ocean from inland desert sources. ?? 2007 Geological Society of America.

Hydrogeologic data for the Big River-Mishnock River stream-aquifer system, central Rhode Island

Science.gov (United States)

Craft, P.A.

2001-01-01

Hydrogeology, ground-water development alternatives, and water quality in the BigMishnock stream-aquifer system in central Rhode Island are being investigated as part of a long-term cooperative program between the Rhode Island Water Resources Board and the U.S. Geological Survey to evaluate the ground-water resources throughout Rhode Island. The study area includes the Big River drainage basin and that portion of the Mishnock River drainage basin upstream from the Mishnock River at State Route 3. This report presents geologic data and hydrologic and water-quality data for ground and surface water. Ground-water data were collected from July 1996 through September 1998 from a network of observation wells consisting of existing wells and wells installed for this study, which provided a broad distribution of data-collection sites throughout the study area. Streambed piezometers were used to obtain differences in head data between surface-water levels and ground-water levels to help evaluate stream-aquifer interactions throughout the study area. The types of data presented include monthly ground-water levels, average daily ground-water withdrawals, drawdown data from aquifer tests, and water-quality data. Historical water-level data from other wells within the study area also are presented in this report. Surface-water data were obtained from a network consisting of surface-water impoundments, such as ponds and reservoirs, existing and newly established partial-record stream-discharge sites, and synoptic surface-water-quality sites. Water levels were collected monthly from the surface-water impoundments. Stream-discharge measurements were made at partial-record sites to provide measurements of inflow, outflow, and internal flow throughout the study area. Specific conductance was measured monthly at partial-record sites during the study, and also during the fall and spring of 1997 and 1998 at 41 synoptic sites throughout the study area. General geologic data, such as

SUBMARINE LANDSLIDE AND LOCALIZED TSUNAMI POTENTIALITY OF MENTAWAI BASIN, SUMATRA, INDONESIA

Directory of Open Access Journals (Sweden)

Haryadi Permana

2017-07-01

Full Text Available The new bathymetry and seismic data were acquired during the PreTI-Gap marine survey (February 15 to March 6, 2008. The survey was carried out along the NE margin of Mentawai Island using multi-beam swath bathymetry equipment, and 28-channels seismic streamer and four-airgun source. The first target was the Mega Island region near the epicenter of the 2007 great earthquake. The shallow bathymetry is characterized as a flat coral platform suggesting that 200 km elongated plateau is slowly subsiding without any active faults. Further north, from South Pagai to North of Siberut Islands, the seafloor morphology changes significantly. The deep and wide canyons or valleys produce very rough seafloor morphology between 50 and 1100 m water. In general, the submarine topography shows two break slopes at different depths. Between slope breaks, the undulating, hilly and circular features dominate, possibly caused by landslides. A push-up ridge is observed that dams the sediments eroded within a steep slope northeastward side. The seismic reflection data acquired along 14 dip seismic lines at the NE flank of Mentawai Islands, from Siberut to the South of Pagai Islands. We observed a set of southwestward dipping back thrust bounding the NE margin of the Mentawai Island. Keywords: submarine landslide, tsunami, Mentawai basin, Sumatra. Data batimetri dan seismik baru telah dihasilkan selama survey kelautan PreTi-Gap (15 Februari hingga 6 Maret 2008. Survei dilaksanakan sepanjang tepian timurlaut P. Mentawai menggunakan peralatan multibeam, seismic saluran ganda 28 kanal dengan sumber energi airgun. Sasaran pertama adalah memetakan kawasan pulau dekat pusat gempa tahun 2007. Kenampakan batimetri dangkal dicirikan dengan adanya dataran terumbu karang yang secara perlahan mengalami penurunan tanpa aktifitas sesar. Lebih jauh ke Utar, dari Pagai Selatan ke utara P. Siberut, morfologi dasar laut memperlihatkan perubahan secara signifikan, dimana lembah dasar laut

DNA barcoding of schistosome cercariae reveals a novel sub-lineage within Schistosoma rodhaini from Ngamba Island Chimpanzee Sanctuary, Lake Victoria.

Science.gov (United States)

Standley, C J; Stothard, J R

2012-10-01

While Schistosoma rodhaini is typically considered a parasite of small mammals and is very scantly distributed in the Lake Victoria basin, it is known to hybridize with the more widespread Schistosoma mansoni, the causative agent of intestinal schistosomiasis. As part of broader parasitological and malacological surveys for S. mansoni across Lake Victoria, schistosome cercariae were harvested from a field-caught Biomphalaria choanomphala taken on Ngamba Island Chimpanzee Sanctuary, Uganda. Upon DNA barcoding, these cercariae were found to be a mixture of both S. rodhaini and S. mansoni, with further phylogenetic analysis revealing a hitherto unknown sub-lineage within S. rodhaini. Despite repeated sampling for eggs and miracidia from both chimpanzees and staff on Ngamba Island Sanctuary, detection of S. rodhaini within local definitive hosts awaits additional efforts, which should be mindful of a potential host role of spotted-necked otters.

Inventory of Selected Freshwater-Ecology Studies From the New England Coastal Basins (Maine, New Hampshire, Massachusetts, Rhode Island), 1937-1997

National Research Council Canada - National Science Library

Tessler, Steven; Coles, James F; Beaulieu, Karen M

1999-01-01

An inventory of published studies that address freshwater ecology within the New England Coastal Basins was created through computerized bibliographic literature searches and consultation with environmental agencies...

Holocene Tree Line and Climate Change on the Queen Charlotte Islands, Canada

Science.gov (United States)

Pellatt, Marlow G.; Mathewes, Rolf W.

1997-07-01

Palynological study of two subalpine ponds on the Queen Charlotte Islands reveals changes in tree line and climate during the Holocene. The findings agree with previous reconstructions, from nearby Louise Pond on the Queen Charlotte Islands, that suggest a warmer-than-present climate and higher-than-present tree lines in the early Holocene (ca. 9600-6600 14C yr B.P.). Basal ages at SC1 Pond and Shangri-La Bog indicate that the basins did not hold permanent water before 7200 14C yr B.P., consistent with a warmer and drier early Holocene previously inferred from Louise Pond. Pollen and plant macrofossils indicate the initial establishment of subalpine conditions by 6090 ± 90 14C yr B.P., similar to the 5790 ± 130 14C yr B.P. age for cooling inferred from Louise Pond. Conditions similar to present were established at SC1 Pond by 3460 ± 100 14C yr B.P., confirming the previous estimate of 3400 14C yr B.P. at Louise Pond. This 3400 14C yr B.P. vegetation shift on the Queen Charlotte Islands corresponds with the beginning of the Tiedemann glacial advance in the south-coastal mountains of British Columbia (ca. 3300 14C yr B.P.), the Peyto and Robson glacial advances between 3300 and 2800 14C yr B.P. in the Rocky Mountains, and climatic cooling inferred from palynological studies throughout southern British Columbia, northern Washington, and southeast Alaska. These findings confirm that changes in regional climate influenced changes in vegetation in coastal British Columbia.

Bryophytes from Simeonof Island in the Shumagin Islands, southwestern Alaska

Science.gov (United States)

Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

2004-01-01

Simeonof Island is located south of the Alaska Peninsula in the hyperoceanic sector of the middle boreal subzone. We examined the bryoflora of Simeonof Island to determine species composition in an area where no previous collections had been reported. This field study was conducted in sites selected to represent the spectrum of environmental variation within Simeonof Island. Data were analyzed using published reports to compare bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 271 bryophytes were identified: 202 mosses and 69 liverworts. The annotated list of species for Simeonof Island expands the known range for many species and fills distribution gaps within Hulte??n's Western Pacific Coast district. Maps and notes on the distribution of 14 significant distribution records are presented. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Simeonof Island primarily includes taxa of boreal (55%), temperate (20%), arctic (10%), and cosmopolitan (8%) distribution; 6% of the moss flora are western North America endemics. A description of the bryophytes present in the vegetation and habitat types is provided as is a quantitative analysis of the most frequently occurring bryophytes in crowberry heath.

On the form of species–area relationships in habitat islands and true islands

DEFF Research Database (Denmark)

Matthews, Thomas J.; Guilhaumon, François; Triantis, Kostas A.

2016-01-01

and c vary between different island types. Location: Global. Methods: We used an information theoretic approach to compare the fit of 20 ISAR models to 207 habitat island datasets. Model performance was ranked according to pre-set criteria, including metrics of generality and efficiency. We also fitted......, and was the highest ranked model overall. In general, the more complex models performed badly. Average z-values were significantly lower for habitat island datasets than for true islands, and were higher for mountaintop and urban habitat islands than for other habitat island types. Average c-values were significantly...... multimodel comparisons demonstrated the nonlinear implementation of the power model to be the best overall model and thus to be a sensible choice for general use. As the z-value of the log–log power model varied in relation to ecological and geographical properties of the study systems, caution should...

Island formation without attractive interaction

NARCIS (Netherlands)

Jansen, A.P.J.

2008-01-01

We show that adsorbates on surfaces can form islands even if there are no attractive interactions. Instead, strong repulsion between adsorbates at short distances can lead to islands, because such islands increase the entropy of the adsorbates that are not part of the islands. We suggest that this

Stability and change in kelp forest habitats at San Nicolas Island

Science.gov (United States)

Kenner, Michael C.; Tinker, M. Tim

2018-01-01

Kelp forest communities are highly variable over space and time. Despite this complexity it has been suggested that kelp forest communities can be classified into one of 2 states: kelp dominated or sea urchin dominated. It has been further hypothesized that these represent “alternate stable states” because a site can remain in either of these states for decades before some perturbation causes a rapid shift to the other state. Our research group has maintained a subtidal community monitoring program for 38 years at San Nicolas Island consisting of twice-annual scuba-based surveys at 6 sites distributed within 4 regions around the island. Three types of perturbations are thought to be relevant to subtidal community dynamics at San Nicolas: (1) physical disturbances in the form of major storm and El Niño/Southern Oscillation (ENSO) events; (2) invertebrate diseases, which periodically decimate urchin populations; and (3) the reintroduction and subsequent increase of sea otters (Enhydra lutris nereis). These 3 perturbations differ in spatial and temporal specificity; physical disturbances and disease outbreaks occur periodically and could affect all 4 regions, while sea otter predation has been concentrated primarily at the West End sites over the last 15 years. The different types of perturbations and the duration of the time series at the kelp forests at San Nicolas make the data set ideal for testing the “alternate stable state” hypothesis. We use nonmetric multidimensional scaling (NMDS) to examine spatial and temporal patterns of community similarity at the 4 regions. In particular, we evaluate support for the existence of stable states, which are represented on NMDS plots as distinct spatial clusters. Community dynamics at each site approximated a biased random walk in NMDS space, with one or more basins of attraction and occasional jumps between basins. We found evidence for alternative stable states at some sites, and we show that transitions from one

Secondhand Smoke Concentrations in Hospitality Venues in the Pacific Basin: Findings from American Samoa, Commonwealth of the Northern Mariana Islands, and Guam

Science.gov (United States)

King, Brian A; Dube, Shanta R; Ko, Jean Y

2015-01-01

Introduction Secondhand smoke (SHS) from burning tobacco products causes disease and premature death among nonsmokers. Although the number of laws prohibiting smoking in indoor public places continues to increase, millions of nonsmokers in the United States (US) and its territories remain exposed to SHS. This study assessed indoor air pollution from SHS in hospitality venues in three US Pacific Basin territories. Methods Air monitors were used to assess PM2.5, an environmental marker for SHS, in 19 smoke-permitted and 18 smoke-free bars and restaurants in American Samoa, Commonwealth of the Northern Mariana Islands (CNMI), and Guam. Observational logs were used to record smoking and other sources of air pollution. Differences in average PM2.5 concentrations were determined using bivariate statistics. Results The average PM2.5 level in venues where smoking was always permitted [arithmetic mean (AM)=299.98 μg/m3; geometric mean (GM)=200.39 μg/m3] was significantly higher (p<0.001) than smoke-free venues [AM=8.33 μg/m3; GM=6.14 μg/m3]. In venues where smoking was allowed only during certain times, the average level outside these times [AM=42.10 μg/m3; GM=41.87 μg/m3] was also significantly higher (p<0.001) than smoke-free venues. Conclusions Employees and patrons of smoke-permitted bars and restaurants are exposed to dangerous levels of air pollution from SHS, even during periods when active smoking is not occurring. Prohibiting smoking in all public indoor areas, irrespective of the venue type or time of day, is the only way to fully protect nonsmokers from SHS exposure in these environments. PMID:22393958

Tales of island tails

NARCIS (Netherlands)

Groot, de Alma V.; Oost, Albert P.; Veeneklaas, Roos M.; Lammerts, Evert Jan; Duin, van Willem E.; Wesenbeeck, van Bregje K.

2016-01-01

The Frisian islands (Southern North Sea) have extensive island tails, i.e. the entire downdrift side of an island consisting of salt marshes, dunes, beaches and beach plains, and green beaches. Currently, large parts of these tails are ageing and losing dynamics, partly due to human influence.

The crustal structure of Ellesmere Island, Arctic Canada—teleseismic mapping across a remote intraplate orogenic belt

Science.gov (United States)

Schiffer, Christian; Stephenson, Randell; Oakey, Gordon N.; Jacobsen, Bo H.

2016-03-01

Ellesmere Island in Arctic Canada displays a complex geological evolution. The region was affected by two distinct orogenies, the Palaeozoic Ellesmerian orogeny (the Caledonian equivalent in Arctic Canada and Northern Greenland) and the Palaeogene Eurekan orogeny, related to the opening of Baffin Bay and the consequent convergence of the Greenland plate. The details of this complex evolution and the present-day deep structure are poorly constrained in this remote area and deep geophysical data are sparse. Receiver function analysis of seven temporary broad-band seismometers of the Ellesmere Island Lithosphere Experiment complemented by two permanent stations provides important data on the crustal velocity structure of Ellesmere Island. The crustal expression of the northernmost tectonic block of Ellesmere Island (˜82°-83°N), Pearya, which was accreted during the Ellesmerian orogeny, is similar to that at the southernmost part, which is part of the Precambrian Laurentian (North America-Greenland) craton. Both segments have thick crystalline crust (˜35-36 km) and comparable velocity-depth profiles. In contrast, crustal thickness in central Ellesmere Island decreases from ˜24-30 km in the Eurekan fold and thrust belt (˜79.7°-80.6°N) to ˜16-20 km in the Hazen Stable Block (HSB; ˜80.6°-81.4°N) and is covered by a thick succession of metasediments. A deep crustal root (˜48 km) at ˜79.6°N is interpreted as cratonic crust flexed beneath the Eurekan fold and thrust belt. The Carboniferous to Palaeogene sedimentary succession of the Sverdrup Basin is inferred to be up to 1-4 km thick, comparable to geologically-based estimates, near the western margin of the HSB.

The Great Basin Canada goose in southcentral Washington: A 40-year nesting history

International Nuclear Information System (INIS)

Fitzner, R.E.; Rickard, W.H.; Eberhardt, L.E.; Gray, R.H.

1991-04-01

Overall, the nesting population of Great Basin Canada geese (Branta canadensis moffitti) on the Hanford Site in southcentral Washington State is doing well and appears to be increasing. The average annual total nests for the period 1981 through 1990 was 215 nests, which is slightly above the average reported for the period 1950 through 1970. The nesting population has shifted its nucleus from upriver islands (1--10) to the lower river islands (11--20) with over 70% of the present-day nesting occurring on Islands 17, 18, 19, 20. The annual percent-successful nests from 1981 through 1990 was 80%. This is above the 71% reported for 1950 to 1970, but is below the 82% reported for 1971 to 1980. Average annual clutch size for 1981 to 1990 was 6.05, which is above the 1971-to-1980 average of 5.6 and the 1950-to-70 average of 5.5. Next desertions for 1981 to 1990 averaged 8%. This rate is well below the 14% reported for 1950 to 1970. Predators were responsible for an annual predation rate of 9% from 1981 to 1990. This is below the 1950-to-1970 annual average predation rate of 14%. Flooding losses to nests were low during the 1980s, except for 1989 and 1990 when 6% and 9% of the total nests, respectively, were destroyed by flooding. 9 refs., 4 figs., 1 tab

Estimating tectonic history through basin simulation-enhanced seismic inversion: Geoinformatics for sedimentary basins

Science.gov (United States)

Tandon, K.; Tuncay, K.; Hubbard, K.; Comer, J.; Ortoleva, P.

2004-01-01

A data assimilation approach is demonstrated whereby seismic inversion is both automated and enhanced using a comprehensive numerical sedimentary basin simulator to study the physics and chemistry of sedimentary basin processes in response to geothermal gradient in much greater detail than previously attempted. The approach not only reduces costs by integrating the basin analysis and seismic inversion activities to understand the sedimentary basin evolution with respect to geodynamic parameters-but the technique also has the potential for serving as a geoinfomatics platform for understanding various physical and chemical processes operating at different scales within a sedimentary basin. Tectonic history has a first-order effect on the physical and chemical processes that govern the evolution of sedimentary basins. We demonstrate how such tectonic parameters may be estimated by minimizing the difference between observed seismic reflection data and synthetic ones constructed from the output of a reaction, transport, mechanical (RTM) basin model. We demonstrate the method by reconstructing the geothermal gradient. As thermal history strongly affects the rate of RTM processes operating in a sedimentary basin, variations in geothermal gradient history alter the present-day fluid pressure, effective stress, porosity, fracture statistics and hydrocarbon distribution. All these properties, in turn, affect the mechanical wave velocity and sediment density profiles for a sedimentary basin. The present-day state of the sedimentary basin is imaged by reflection seismology data to a high degree of resolution, but it does not give any indication of the processes that contributed to the evolution of the basin or causes for heterogeneities within the basin that are being imaged. Using texture and fluid properties predicted by our Basin RTM simulator, we generate synthetic seismograms. Linear correlation using power spectra as an error measure and an efficient quadratic

Energy Self-Sufficient Island

International Nuclear Information System (INIS)

Bratic, S.; Krajacic, G.; Duic, N.; Cotar, A.; Jardas, D.

2011-01-01

In order to analyze energy self-sufficient island, example of a smaller island, connected to the power system of a bigger island with an undersea cable, was taken. Mounting substation 10/0,4 is situated on the island and for the moment it provides enough electricity using the medium voltage line. It is assumed that the island is situated on the north part of the Adriatic Sea. The most important problem that occurs on the island is the population drop that occurs for a significant number of years, therefore, life standard needs to be improved, and economic development needs to be encouraged immediately. Local authorities to stimulate sustainable development on the island through different projects, to breath in a new life to the island, open new jobs and attract new people to come live there. Because of the planned development and increase of the population, energy projects, planned as a support to sustainable development, and later achievement of the energy self-sufficiency, is described in this paper. Therefore, Rewisland methodology appliance is described taking into the account three possible scenarios of energy development. Each scenario is calculated until year 2030. Also, what is taken into the account is 100% usage of renewable sources of energy in 2030. Scenario PTV, PP, EE - This scenario includes installation of solar photovoltaic modules and solar thermal collectors on the buildings roofs, as well as well as implementation of energy efficiency on the island (replacement of the street light bulbs with LED lightning, replacement of the old windows and doors on the houses, as well as the installation of the thermal insulation). Scenario PV island - This scenario, similarly to the previous one, includes installation of solar photovoltaic modules and solar thermal collectors an the residential buildings, as well as the 2 MW photovoltaic power plant and ''Green Hotel'', a building that satisfies all of its energy needs completely from renewable energy sources

3-D basin modelling of the Paris Basin: diagenetic and hydrogeologic implications

International Nuclear Information System (INIS)

Violette, S.; Goncalves, J.; Jost, A.; Marsily, G. de

2004-01-01

A 3-D basin model of the Paris basin is presented in order to simulate through geological times fluid, heat and solute fluxes. This study emphasizes: i) the contribution of basin models to the quantitative hydrodynamic understanding of behaviour of the basin over geological times; ii) the additional use of Atmospheric General Circulation model (AGCM) to provide palaeo-climatic boundaries for a coupled flow and mass transfer modelling, constrained by geochemical and isotopic tracers and; iii) the integration of different types of data (qualitative and quantitative) to better constrain the simulations. Firstly, in a genetic way, basin model is used to reproduce geological, physical and chemical processes occurring in the course of the 248 My evolution of the Paris basin that ought to explain the present-day hydraulic properties at the regional scale. As basin codes try to reproduce some of these phenomena, they should be able to give a plausible idea of the regional-scale permeability distribution of the multi-layered system, of the pre-industrial hydrodynamic conditions within the aquifers and of the diagenesis timing and type of hydrodynamic processes involved. Secondly, climate records archived in the Paris basin groundwater suggest that climate and morphological features have an impact on the hydrogeological processes, particularly during the last 5 My. An Atmospheric General Circulation model is used with a refined spatial resolution centred on the Paris basin to reproduce the climate for the present, the Last Glacial Maximum (21 ky) and the middle Pliocene (3 My). These climates will be prescribed, through forcing functions to the hydrological code with the main objective of understanding the way aquifers and aquitards react under different climate conditions, the period and the duration of these effects. Finally, the Paris basin has been studied for a number of years by different scientific communities, thus a large amount of data has been collected. By

One million served: Rhode Island`s recycling facility

Energy Technology Data Exchange (ETDEWEB)

Malloy, M.G.

1997-11-01

Rhode Island`s landfill and adjacent materials recovery facility (MRF) in Johnston, both owned by the quasi-public Rhode Island Resource Recovery Corp. (RIRRC, Johnston), serve the entire state. The $12-million recycling facility was built in 1989 next to the state`s sole landfill, the Central Landfill, which accepts only in-state trash. The MRF is operated for RIRRC by New England CRInc. (Hampton, N.H.), a unit of Waste Management, Inc. (WMI, Oak Brook, Ill.). It handles a wide variety of materials, from the usual newspaper, cardboard, and mixed containers to new streams such as wood waste, scrap metal, aseptic packaging (milk and juice boxes), and even textiles. State municipalities are in the process of adding many of these new recyclable streams into their curbside collection programs, all of which feed the facility.

Immigrants, islandness and perceptions of quality-of-life on Prince Edward Island, Canada

Directory of Open Access Journals (Sweden)

Peter Kitchen

2014-11-01

Full Text Available This paper explores perceptions of immigrant quality-of-life (QOL and islandness in Charlottetown, Prince Edward Island, Canada, and compares these perceptions to those of Canadian-born residents of the same provincial capital. The study employed a mixed-methods approach, including a household telephone survey conducted in the summer of 2012 (n=302, focus group interviews with immigrants in late 2012 and observations on preliminary results by the staff of the PEI Association of Newcomers to Canada (PEIANC, the primary immigrant settlement service agency on the island. The analysis of the results suggests that immigrants have a high and undifferentiated assessment of their own QOL, sense of belonging and sense of place compared to Canadian-born islanders; immigrants are also critical of the quality of education and of the range of recreational and cultural events underway on the Island. While they express positive sentiments regarding life on the Island, immigrants still feel excluded from social and economic opportunities.

Tectonomagmatic activity and ice dynamics in the Bransfield Strait back-arc basin, Antarctica

Science.gov (United States)

Dziak, Robert P.; Park, Minkyu; Lee, Won Sang; Matsumoto, Haru; Bohnenstiehl, Delwayne R.; Haxel, Joseph H.

2010-01-01

An array of moored hydrophones was used to monitor the spatiotemporal distribution of small- to moderate-sized earthquakes and ice-generated sounds within the Bransfield Strait, Antarctica. During a 2 year period, a total of 3900 earthquakes, 5925 icequakes and numerous ice tremor events were located throughout the region. The seismic activity included eight space-time earthquake clusters, positioned along the central neovolcanic rift zone of the young Bransfield back-arc basin. These sequences of small magnitude earthquakes, or swarms, suggest ongoing magmatic activity that becomes localized along isolated volcanic features and fissure-like ridges in the southwest portion of the basin. A total of 122 earthquakes were located along the South Shetland trench, indicating continued deformation and possibly ongoing subduction along this margin. The large number of icequakes observed show a temporal pattern related to seasonal freeze-thaw cycles and a spatial distribution consistent with channeling of sea ice along submarine canyons from glacier fronts. Several harmonic tremor episodes were sourced from a large (˜30 km2) iceberg that entered northeast portion of the basin. The spectral character of these signals suggests they were produced by either resonance of a small chamber of fluid within the iceberg, or more likely, due to periodicity of discrete stick-slip events caused by contact of the moving iceberg with the seafloor. These pressure waves appear to have been excited by abrasion of the iceberg along the seafloor as it passed Clarence and Elephant Islands.

Pathogenicity island mobility and gene content.

Energy Technology Data Exchange (ETDEWEB)

Williams, Kelly Porter

2013-10-01

Key goals towards national biosecurity include methods for analyzing pathogens, predicting their emergence, and developing countermeasures. These goals are served by studying bacterial genes that promote pathogenicity and the pathogenicity islands that mobilize them. Cyberinfrastructure promoting an island database advances this field and enables deeper bioinformatic analysis that may identify novel pathogenicity genes. New automated methods and rich visualizations were developed for identifying pathogenicity islands, based on the principle that islands occur sporadically among closely related strains. The chromosomally-ordered pan-genome organizes all genes from a clade of strains; gaps in this visualization indicate islands, and decorations of the gene matrix facilitate exploration of island gene functions. A %E2%80%9Clearned phyloblocks%E2%80%9D method was developed for automated island identification, that trains on the phylogenetic patterns of islands identified by other methods. Learned phyloblocks better defined termini of previously identified islands in multidrug-resistant Klebsiella pneumoniae ATCC BAA-2146, and found its only antibiotic resistance island.

First record of the mycoheterotrophic orchid Gastrodia fontinalis (Orchidaceae from Takeshima Island, the Ryukyu Islands, Japan

Directory of Open Access Journals (Sweden)

Kenji Suetsugu

2014-12-01

Full Text Available We found Gastrodia fontinalis T. P. Lin in a bamboo forest from Takeshima Island, which is the northernmost island of the Ryukyu Islands in Japan. This species is apparently rare and was previously considered to be an endemic Taiwanese species. Because there are a few minor differences between the original description and our specimens collected in Takeshima Island, here we report Gastrodia fontinalis from Takeshima Island as the first record outside of Taiwan, with a description of the specimens from Takeshima Island.

Renewable energy islands in Europe

Energy Technology Data Exchange (ETDEWEB)

Oestergaard, Iben [ed.

1998-12-31

This publication includes a compiled presentation of various aspects concerning the possible transformation of some European islands into renewable energy communities and these projects were presented by a selection of pioneer islands at the first European Seminar on Renewable Energy Islands, held on the Danish island of Samsoee, 29-30 June 1998. This issue has increased in importance with the presentation of the ambitious EU-White Paper: `Energy for the future: Renewable Sources of Energy` which was adopted in 1998. One of the key elements of the strategy for an accelerated implementation of renewable energy is to transform 100 localities within Europe into communities which are to be 100% self-sufficient with renewable energy before 2010. In line with this strategy, the Danish Government appointed the island of Samsoe towards the end of 1997 to be the first `official` Danish, renewable energy island. This is to serve as a demonstration project for other local communities, both in Denmark as well as in the rest Europe. Gothland, Madeira, Canary Islands, Cape Verde, Arki, Crete, Minorca and Orkney Islands were represented. Environmental advantages of wind, solar and wave power for distant island communities were indicated. Serious savings would be achieved by limitation of fossil fuel import and utilization of local resources. (EG)

Barrier island habitat map and vegetation survey—Dauphin Island, Alabama, 2015

Science.gov (United States)

Enwright, Nicholas M.; Borchert, Sinéad M.; Day, Richard H.; Feher, Laura C.; Osland, Michael J.; Wang, Lei; Wang, Hongqing

2017-08-04

Barrier islands are dynamic environments due to their position at the land-sea interface. Storms, waves, tides, currents, and relative sea-level rise are powerful forces that shape barrier island geomorphology and habitats (for example, beach, dune, marsh, and forest). Hurricane Katrina in 2005 and the Deep Water Horizon oil spill in 2010 are two major events that have affected habitats and natural resources on Dauphin Island, Alabama. The latter event prompted a collaborative effort between the U.S. Geological Survey, the U.S. Army Corps of Engineers, and the State of Alabama funded by the National Fish and Wildlife Foundation to investigate viable, sustainable restoration options that protect and restore the natural resources of Dauphin Island, Alabama.In order to understand the feasibility and sustainability of various restoration scenarios, it is important to understand current conditions on Dauphin Island. To further this understanding, a detailed 19-class habitat map for Dauphin Island was produced from 1-foot aerial infrared photography collected on December 4, 2015, and lidar data collected in January 2015. We also conducted a ground survey of habitat types, vegetation community structure, and elevations in November and December 2015. These products provide baseline data regarding the ecological and general geomorphological attributes of the area, which can be compared with observations from other dates for tracking changes over time.

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Morris Island, SC to Hilton Head..., SC to Hilton Head Island, SC. (a) A line drawn from the easternmost tip of Folley Island to the... easternmost extremity of Hilton Head at latitude 32°13.0′ N. longitude 80°40.1′ W. [CGD 77-118a, 42 FR 35784...

Island dynamics and Minoan expansion in the Aegean: the Kythera Island Project

Directory of Open Access Journals (Sweden)

Cyprian Broodbank

1999-11-01

Full Text Available In recent years archaeologists have become increasingly interested in the investigation of island societies. At a global level, discoveries in the Pacific, Caribbean, Mediterranean and elsewhere have greatly improved our understanding of the antiquity and dynamics of island life. Now archaeologists at the Institute, together with other colleagues, have embarked on a long-term interdisciplinary study of the island of Kythera in the Aegean.

Fishes of the Taquari-Antas river basin (Patos Lagoon basin, southern Brazil

Directory of Open Access Journals (Sweden)

FG. Becker

Full Text Available The aquatic habitats of the Taquari-Antas river basin (in the Patos Lagoon basin, southern Brazil are under marked environmental transformation because of river damming for hydropower production. In order to provide an information baseline on the fish fauna of the Taquari-Antas basin, we provide a comprehensive survey of fish species based on primary and secondary data. We found 5,299 valid records of fish species in the basin, representing 119 species and 519 sampling sites. There are 13 non-native species, six of which are native to other Neotropical river basins. About 24% of the total native species are still lacking a taxonomic description at the species level. Three native long-distance migratory species were recorded (Leporinus obtusidens, Prochilodus lineatus, Salminus brasiliensis, as well as two potential mid-distance migrators (Parapimelodus nigribarbis and Pimelodus pintado. Although there is only one officially endangered species in the basin (S. brasiliensis, restricted range species (21.7% of total species should be considered in conservation efforts.

Vegetation and checklist of Inaccessible Island, central South Atlantic Ocean, with notes on Nightingale Island

Directory of Open Access Journals (Sweden)

J. P. Roux

1992-10-01

Full Text Available The physiography and climate of Inaccessible and Nightingale Islands are briefly discussed. The vegetation and the major plant associations are described. Notes are given on the ecology and distribution of each taxon. Taxa newly recorded for Inaccessible Island include Agrostis goughensis, A.holgateana, A. wacei, Calamagrostis deschampsiiformis, Carex thouarsii var.  recurvata, Conyza albida, Elaphoglossum campylolepium and  Uncinia meridensis. One species, C.  albida, is alien to the Tristan group. Two native ferns Asplenium platybasis var.  subnudum and Blechnum australe were found on Nightingale Island for the first time, and the presence of introduced Malus domestica orchards was recorded. Two unidentified taxa were found that may represent new species:  Elaphoglossum sp. at Inaccessible Island and Apium sp. at both Inaccessible and Nightingale Islands. The total number of vascular plant species recorded at Inaccessible and Nightingale Islands now stands at 98 and 43, respectively, of which 26 (28% and seven (16% are introduced species. Only Airiplex plebeja and two species of Cotula occur at Nightingale Island but are absent from Inaccessible Island.

Marshall Islands

OpenAIRE

World Bank

2015-01-01

This note aims to build understanding of the existing disaster risk financing and insurance (DRFI) tools in use in The Marshall Islands and to identify gaps where potential engagement could further develop financial resilience. The likelihood that a hazardous event will have a significant impact on the Marshall Islands has risen with the increasing levels of population and assets in the urban ...

A man and his island: The island mirror in Michael Crummey’s Sweetland

Directory of Open Access Journals (Sweden)

Laurie Brinklow

2016-05-01

Full Text Available Between 1946 and 1975, dozens of islands and outports in the Canadian province of Newfoundland and Labrador were abandoned as part of a government resettlement policy. Families and communities were torn apart, and a culture and way of life that revolved around the fishery changed irrevocably. The practice, which continues to this day, has been well documented, particularly by artists and writers. Michael Crummey’s 2014 novel Sweetland is a recent iteration. The relationship between humans and place is complex: on an island, with compressed space and a very real boundary that is the ocean, emotional attachments to one’s place are often heightened and distilled. What happens when a person is displaced from his or her island; when bonds of attachment are severed and one’s mirrored double is destroyed? Sweetland offers a fictional lens through which we see an example of a mirrored relationship between an island protagonist and his island setting. Exploring themes of attachment to place, and what Barry Lopez calls a “storied” or “reciprocal” relationship with the land, this paper examines what happens to a man when confronted with leaving an island he knows as deeply as his own body and soul; and how the island reacts.

K-Basins design guidelines

International Nuclear Information System (INIS)

Roe, N.R.; Mills, W.C.

1995-06-01

The purpose of the design guidelines is to enable SNF and K Basin personnel to complete fuel and sludge removal, and basin water mitigation by providing engineering guidance for equipment design for the fuel basin, facility modifications (upgrades), remote tools, and new processes. It is not intended to be a purchase order reference for vendors. The document identifies materials, methods, and components that work at K Basins; it also Provides design input and a technical review process to facilitate project interfaces with operations in K Basins. This document is intended to compliment other engineering documentation used at K Basins and throughout the Spent Nuclear Fuel Project. Significant provisions, which are incorporated, include portions of the following: General Design Criteria (DOE 1989), Standard Engineering Practices (WHC-CM-6-1), Engineering Practices Guidelines (WHC 1994b), Hanford Plant Standards (DOE-RL 1989), Safety Analysis Manual (WHC-CM-4-46), and Radiological Design Guide (WHC 1994f). Documents (requirements) essential to the engineering design projects at K Basins are referenced in the guidelines

Island development: Local governance under globalization

Directory of Open Access Journals (Sweden)

Huei-Min Tsai

2014-12-01

Full Text Available Issues surrounding island development have generated a growing volume of research. What does it mean to develop? How can island communities maintain control over development processes to the benefit of the local economy, rather than seeing economic flows enter and exit the island with little or a primarily negative impact? And how important is local knowledge for edifying local governance and enhancing potentials for innovation in island development? Island histories have repeatedly been forwarded as exemplars and ‘lessons’ for global learning on (unsustainability. To consider these issues, we have selected a number of papers from among the presentations given at the International Geographical Union’s Commission on Islands Conference, Island Development: Local Economy, Culture, Innovation and Sustainability, which took place in the Penghu Archipelago, Taiwan, 1–5 October 2013. These papers serve as examples of how the processes of globalization have penetrated the borders and changed the political and economic structures of islands. They also explore how island-based innovations in science, technology, culture, and formal or informal governance might contribute to sustainable island development.

Energy Transition Initiative, Island Energy Snapshot - British Virgin Islands (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2015-03-01

This profile provides a snapshot of the energy landscape of the British Virgin Islands (BVI), one of three sets of the Virgin Island territories in an archipelago making up the northern portion of the Lesser Antilles.

Intra- and inter-basin mercury comparisons: Importance of basin scale and time-weighted methylmercury estimates

International Nuclear Information System (INIS)

Bradley, Paul M.; Journey, Celeste A.; Brigham, Mark E.; Burns, Douglas A.; Button, Daniel T.; Riva-Murray, Karen

2013-01-01

To assess inter-comparability of fluvial mercury (Hg) observations at substantially different scales, Hg concentrations, yields, and bivariate-relations were evaluated at nested-basin locations in the Edisto River, South Carolina and Hudson River, New York. Differences between scales were observed for filtered methylmercury (FMeHg) in the Edisto (attributed to wetland coverage differences) but not in the Hudson. Total mercury (THg) concentrations and bivariate-relationships did not vary substantially with scale in either basin. Combining results of this and a previously published multi-basin study, fish Hg correlated strongly with sampled water FMeHg concentration (ρ = 0.78; p = 0.003) and annual FMeHg basin yield (ρ = 0.66; p = 0.026). Improved correlation (ρ = 0.88; p < 0.0001) was achieved with time-weighted mean annual FMeHg concentrations estimated from basin-specific LOADEST models and daily streamflow. Results suggest reasonable scalability and inter-comparability for different basin sizes if wetland area or related MeHg-source-area metrics are considered. - Highlights: ► National scale mercury assessments integrate small scale study results. ► Basin scale differences and representativeness of fluvial mercury samples are concerns. ► Wetland area, not basin size, predicts inter-basin methylmercury variability. ► Time-weighted methylmercury estimates improve the prediction of mercury in basin fish. - Fluvial methylmercury concentration correlates with wetland area not basin scale and time-weighted estimates better predict basin top predator mercury than discrete sample estimates.

Holocene sea-level change and the emergence of Neolithic seafaring in the Fuzhou Basin (Fujian, China)

Science.gov (United States)

Rolett, Barry V.; Zheng, Zhuo; Yue, Yuanfu

2011-04-01

Neolithic seafaring across the Taiwan Strait began approximately 5000 years ago and involved open-sea voyages over distances of at least 130 km. Rapid sea-level rise preceded the emergence of open-sea voyaging, but the possible role of environmental change as a stimulus for the development of seafaring is poorly understood. We investigate this problem by presenting a record of Holocene sea-level change and coastal transformation based on sediment cores obtained from the Fuzhou Basin on the coast of Fujian, China. The cores are located in direct proximity to archaeological sites of the Tanshishan Neolithic culture (5000-4300 cal BP), which is significant for its similarity to the earliest Neolithic cultures of Taiwan. Multiple lines of evidence record the early Holocene inundation of the Fuzhou Basin around 9000 cal BP, the mid-Holocene sea-level highstand, and the final Holocene marine transgression. This final transition is precisely documented, with AMS dates showing the change occurred close to 1900 cal BP. Our paleogeographic reconstruction shows that a large estuary filled the Fuzhou Basin during the mid-Holocene. Tanshishan and Zhuangbianshan, two of the major Fuzhou Basin Neolithic sites, are located today on hills nearly 80 km from the modern coastline. However, when the sites were settled around 5500-5000 cal BP, the marine transgression had transformed these hills into islands in the upper estuary. We suggest that the Neolithic era estuary setting, together with the lack of land suitable for rice paddy agriculture, inhibited intensive food production but favored a maritime orientation and the development of seafaring.

Demographic Ageing on Croatian Islands

Directory of Open Access Journals (Sweden)

Ivo Nejašmić

2013-08-01

Full Text Available This paper analyses the changes in the population structure of the Croatian islands by age, warns of the degree of ageing, provides spatial differentiation of this process and presents perspective of ageing at the level of settlement. Typing of population ageing is based on scores and has seven types. The total island population in 2011 belongs to the type 5 – very old population. Almost a half of the settlements (out of 303 have been affected by the highest levels of ageing (types 6 and 7. It was found that a quarter of island settlements will become “dead villages” in a foreseeable future; most of them are on small islands but also in the interior of larger islands. These are villages decaying in every respect, in which the way of life, as we know it, veins and goes out. The present ageing villagers are their last residents in most cases. Eve¬rything suggests that demographic recovery of the islands is not possible with the forces in situ. It is important to strike a balance between the needs and opportunities in order to successfully organize life on the islands, both small and large ones, and the fact is that there is a continuing disparity, which is especially profound in small islands. A sensitive and selective approach is needed to overcome the unfavourable demographic trends. Therefore it is necessary to respect the particularities of indi¬vidual islands and island groups in devising development strategy. Solutions to the problems must come of the local and wider community in synergy with relevant professional and scientific institutions. However, if the solutions are not found or measures do not give results, if the islands are left to desorganisation and senilisation, a part of the islands will become a wasteland. With regard to the value of this area whose wealth are people in the first place, this would be an intolerable civilization decline.

The Island Smart Energy System and Market

DEFF Research Database (Denmark)

Ma, Zheng; Billanes, Joy Dalmacio; Jørgensen, Bo Nørregaard

2017-01-01

developing island smart energy systems with the integration of renewable energy resources can increase the energy supply and address the global island energy issues. The island smart energy system operates either in a single-island or in multi-islands. However the island characteristics and influ...

Terrestrial bird population trends on Aguiguan (Goat Island), Mariana Islands

Science.gov (United States)

Amidon, Fred; Camp, Richard J.; Marshall, Ann P.; Pratt, Thane K.; Williams, Laura; Radley, Paul; Cruz, Justine B.

2014-01-01

The island of Aguiguan is part of the Mariana archipelago and currently supports populations of four endemic species, including one endemic genus, Cleptornis. Bird population trends since 1982 were recently assessed on the neighbouring islands of Saipan, Tinian, and Rota indicating declines in some native species. Point-transect surveys were conducted in 2008 by the U.S. Fish and Wildlife Service to assess population densities and trends on Aguiguan. Densities for six of the nine native birds—White-throated Ground-dove Gallicolumba xanthonura, Collared Kingfisher Todiramphus chloris, Rufous Fantail Rhipidura rufifrons, Golden White-eye Cleptornis marchei, Bridled White-eye Zosterops conspicillatus and Micronesian Starling Aplonis opaca—and the non-native bird—Island Collared-dove Streptopelia bitorquata—were significantly greater in 2008 than in 1982. No differences in densities were detected among the surveys for Mariana Fruit-dove Ptilinopus roseicapilla, and Micronesian MyzomelaMyzomela rubratra. Three federally and locally listed endangered birds—Nightingale Reed-warbler Acrocephalus luscinius, Mariana Swiftlet Collocalia bartschi, and Micronesian Megapode Megapodius laperous)—were either not detected during the point-transect counts, the surveys were not appropriate for the species, or the numbers of birds detected were too small to estimate densities. The factors behind the increasing trends for some species are unknown but may be related to increased forest cover on the island since 1982. With declining trends for some native species on neighbouring islands, the increasing and stable trends on Aguiguan is good news for forest bird populations in the region, as Aguiguan populations can help support conservation efforts on other islands in the archipelago.

Renewable technologies for generation systems in islands and their application to Cozumel Island, Mexico

OpenAIRE

Mendoza Vizcaino, Javier; Sumper, Andreas; Sudrià Andreu, Antoni; Ramirez, J.M.

2016-01-01

The electric generation systems on islands are based generally on fossil fuel. This fact and its supply make the electricity cost higher than in systems used in the continent. In this article, we present a review of the renewable energy generation systems on islands. To do it we analysed 77 islands from 45 different countries. This work will allow us to know how the implementation of renewable energy sources could help these islands in developing a renewable and sustainable energy sector, inc...

Uranium distribution and sandstone depositional environments: oligocene and upper Cretaceous sediments, Cheyenne basin, Colorado

International Nuclear Information System (INIS)

Nibbelink, K.A.; Ethridge, F.G.

1984-01-01

Wyoming-type roll-front uranium deposits occur in the Upper Cretaceous Laramie and Fox Hills sandstones in the Cheyenne basin of northeastern Colorado. The location, geometry, and trend of specific depositional environments of the Oligocene White River and the Upper Cretaceous Laramie and Fox Hills formations are important factors that control the distribution of uranium in these sandstones. The Fox Hills Sandstone consists of up to 450 ft (140 m) of nearshore marine wave-dominated delta and barrier island-tidal channel sandstones which overlie offshore deposits of the Pierre Shale and which are overlain by delta-plain and fluvial deposits of the Laramie Formation. Uranium, which probably originated from volcanic ash in the White River Formation, was transported by groundwater through the fluvial-channel deposits of the White River into the sandstones of the Laramie and Fox Hills formations where it was precipitated. Two favorable depositional settings for uranium mineralization in the Fox Hills Sandstone are: (1) the landward side of barrier-island deposits where barrier sandstones thin and interfinger with back-barrier organic mudstones, and (2) the intersection of barrier-island and tidal channel sandstones. In both settings, sandstones were probably reduced during early burial by diagenesis of contained and adjacent organic matter. The change in permeability trends between the depositional strike-oriented barrier sandstones and the dip-oriented tidal-channel sandstones provided sites for dispersed groundwater flow and, as demonstrated in similar settings in other depositional systems, sites for uranium mineralization

CRED Gridded Bathymetry near Laysan Island (100-006), Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-006b is a 60-m ASCII grid of depth data collected near Laysan Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as...

CRED Gridded Bathymetry near Lisianski Island (100-001), Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-001b is a 60-m ASCII grid of depth data collected near Lisianski Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as...

75 FR 61993 - Amendment of Class E Airspace; Kwajalein Island, Marshall Islands, RMI

Science.gov (United States)

2010-10-07

...This action removes the reference to the Kwajalein Tactacial Air Navigation (TACAN) System from the legal description of the Class E airspace areas for Kwajalein Island, Bucholz AAF, Marshall Islands, RMI. The U.S. Army notified the FAA that the Kwajalein TACAN was decommissioned. This action corrects the legal descriptions for the Class E airspace areas in the vicinity of the Marshall Islands.

Occurrence of the lessepsian species Portunus pelagicus (Crustacea and Apogon pharaonis (Pisces in the marine area of Rhodes Island

Directory of Open Access Journals (Sweden)

M. CORSINI-FOKA

2004-06-01

Full Text Available A large number of Red Sea species are colonizing the eastern Mediterranean Sea via the Suez Canal, mainly following the Anatolian coasts and spreading westwards. Portunus pelagicus is one of the most common Red Sea swimming crabs, first recorded in the Levantine Basin in 1898. Four specimens of P. pelagicus were collected in different marine areas of Rhodes Island from 1991 to 2000, while three specimens of the lessepsian fish Apogon pharaonis, first recorded in the Mediterranean in 1947, were caught during 2002 in the NW coast of Rhodes. The sub-tropical character of the marine area around Rhodes seems to facilitate the propagation of lessepsian species. These migrants have reached the island at different velocity and degree of establishment of their populations. The occurrence of the blue swimmer crab P. pelagicus and of the bullseye cardinal fish A. pharaonis increases the number of the decapod Crustacea and fish species of Red Sea origin observed in Greek waters.

Marshall Islands Fringing Reef and Atoll Lagoon Observations of the Tohoku Tsunami

Science.gov (United States)

Ford, Murray; Becker, Janet M.; Merrifield, Mark A.; Song, Y. Tony

2014-12-01

The magnitude 9.0 Tohoku earthquake on 11 March 2011 generated a tsunami which caused significant impacts throughout the Pacific Ocean. A description of the tsunami within the lagoons and on the surrounding fringing reefs of two mid-ocean atoll islands is presented using bottom pressure observations from the Majuro and Kwajalein atolls in the Marshall Islands, supplemented by tide gauge data in the lagoons and by numerical model simulations in the deep ocean. Although the initial wave arrival was not captured by the pressure sensors, subsequent oscillations on the reef face resemble the deep ocean tsunami signal simulated by two numerical models, suggesting that the tsunami amplitudes over the atoll outer reefs are similar to that in deep water. In contrast, tsunami oscillations in the lagoon are more energetic and long lasting than observed on the reefs or modelled in the deep ocean. The tsunami energy in the Majuro lagoon exhibits persistent peaks in the 30 and 60 min period bands that suggest the excitation of closed and open basin normal modes, while energy in the Kwajalein lagoon spans a broader range of frequencies with weaker, multiple peaks than observed at Majuro, which may be associated with the tsunami behavior within the more irregular geometry of the Kwajalein lagoon. The propagation of the tsunami across the reef flats is shown to be tidally dependent, with amplitudes increasing/decreasing shoreward at high/low tide. The impact of the tsunami on the Marshall Islands was reduced due to the coincidence of peak wave amplitudes with low tide; however, the observed wave amplitudes, particularly in the atoll lagoon, would have led to inundation at different tidal phases.

Steelhead Spawning Surveys Near Locke Island, Hanford Reach of the Columbia River; TOPICAL

International Nuclear Information System (INIS)

DR Geist; RP Mueller

1999-01-01

In 1997, the National Marine Fisheries Service (NMFS) listed upper Columbia River steelhead trout (Oncorhynchus znykiss) as endangered. This action affected management of land-use activities along and within the Hanford Reach of the Columbia River, which flows through the U.S. Department of Energy (DOE) Hanford Site. Steelhead covered in this listing include all naturally spawned populations of steel-head and their progeny in streams in the Columbia River Basin upstream from the Yakima River to the United States/Canada border. The NMFS has identified a general listing of activities that could potentially result in harm to steelhead (62 FR 43937, August 18, 1997). One of these concerns includes land-use changes resulting in mass wasting or surface erosion. Landslide activity along the White Bluffs on the east ,side of Locke Island has redirected river flow into the island where substantial erosion has occurred. This erosion has exposed important anthropological and archaeological resources that were previously buried on the island. The DOE is working with affected tribes and other agencies to develop a plan for addressing the erosion of Locke Island. As part of this effort, the U.S. Army Corps of Engineers has prepared an assessment of potential alternatives to stabilize the erosion, including a no-action alternative. Steelhead historically spawned in the vicinity of Locke Island, but recent information on the occurrence of steelhead spawning or availability of spawning habitat was lacking. Therefore, the purpose of this study was to determine if steelhead spawned in the vicinity of Locke Island erosion and to evaluate the composition of substrate in the affected area. Surveys to document the occurrence of steelheads redds were conducted in Spring 1999. The surveys were conducted from the air as well as with the use of an underwater video camera. Neither aerial nor underwater surveys documented steelhead spawning within the survey area. Habitat surveys were

Returning from the Horizon: Introducing Urban Island Studies

Directory of Open Access Journals (Sweden)

Xavier Barceló Pinya

2015-12-01

Full Text Available Island studies tends to focus on peripheral, isolated, and marginal aspects of island communities, while urban studies has showed scant awareness of islandness: Although many people research cities on islands, there is little tradition of researching island cities or urban archipelagos per se. Island cities (densely populated small islands and population centres of larger islands and archipelagos nevertheless play import cultural, economic, political, and environmental roles on local, regional, and global scales. Many major cities and ports have developed on small islands, and even villages can fulfil important urban functions on lightly populated islands. Island concepts are also deployed to metaphorically describe developments in urban space. The journal Urban Island Studies explores island and urban processes around the world, taking an island approach to urban research and an urban approach to island research.

Barrier island facies models and recognition criteria

Science.gov (United States)

Mulhern, J.; Johnson, C. L.

2017-12-01

Barrier island outcrops record transgressive shoreline motion at geologic timescales, providing integral clues to understanding how coastlines respond to rising sea levels. However, barrier island deposits are difficult to recognize. While significant progress has been made in understanding the modern coastal morphodynamics, this insight is not fully leveraged in existing barrier island facies models. Excellent outcrop exposures of the paralic Upper Cretaceous Straight Cliffs Formation of southern Utah provide an opportunity to revise facies models and recognition criteria for barrier island deposits. Preserved barrier islands are composed of three main architectural elements (shorefaces, tidal inlets, and tidal channels) which occur independently or in combination to create larger-scale barrier island deposits. Barrier island shorefaces record progradation, while barrier island tidal inlets record lateral migration, and barrier island tidal channels record aggradation within the tidal inlet. Four facies associations are used to describe and characterize these barrier island architectural elements. Barrier islands occur in association with backarrier fill and internally contain lower and upper shoreface, high-energy upper shoreface, and tidal channel facies. Barrier islands bound lagoons or estuaries, and are distinguished from other shoreface deposits by their internal facies and geometry, association with backbarrier facies, and position within transgressive successions. Tidal processes, in particular tidal inlet migration and reworking of the upper shoreface, also distinguish barrier island deposits. Existing barrier island models highlight the short term heterogeneous and dynamic nature of barrier island systems, yet overlook processes tied to geologic time scales, such as multi-directional motion, erosion, and reworking, and their expressions in preserved barrier island strata. This study uses characteristic outcrop expressions of barrier island successions to

Origin and diet of the prehistoric hunter-gatherers on the mediterranean island of Favignana (Ègadi Islands, Sicily.

Directory of Open Access Journals (Sweden)

Marcello A Mannino

Full Text Available Hunter-gatherers living in Europe during the transition from the late Pleistocene to the Holocene intensified food acquisition by broadening the range of resources exploited to include marine taxa. However, little is known on the nature of this dietary change in the Mediterranean Basin. A key area to investigate this issue is the archipelago of the Ègadi Islands, most of which were connected to Sicily until the early Holocene. The site of Grotta d'Oriente, on the present-day island of Favignana, was occupied by hunter-gatherers when Postglacial environmental changes were taking place (14,000-7,500 cal BP. Here we present the results of AMS radiocarbon dating, palaeogenetic and isotopic analyses undertaken on skeletal remains of the humans buried at Grotta d'Oriente. Analyses of the mitochondrial hypervariable first region of individual Oriente B, which belongs to the HV-1 haplogroup, suggest for the first time on genetic grounds that humans living in Sicily during the early Holocene could have originated from groups that migrated from the Italian Peninsula around the Last Glacial Maximum. Carbon and nitrogen isotope analyses show that the Upper Palaeolithic and Mesolithic hunter-gatherers of Favignana consumed almost exclusively protein from terrestrial game and that there was only a slight increase in marine food consumption from the late Pleistocene to the early Holocene. This dietary change was similar in scale to that at sites on mainland Sicily and in the rest of the Mediterranean, suggesting that the hunter-gatherers of Grotta d'Oriente did not modify their subsistence strategies specifically to adapt to the progressive isolation of Favignana. The limited development of technologies for intensively exploiting marine resources was probably a consequence both of Mediterranean oligotrophy and of the small effective population size of these increasingly isolated human groups, which made innovation less likely and prevented transmission of

Origin and Diet of the Prehistoric Hunter-Gatherers on the Mediterranean Island of Favignana (Ègadi Islands, Sicily)

Science.gov (United States)

Mannino, Marcello A.; Catalano, Giulio; Talamo, Sahra; Mannino, Giovanni; Di Salvo, Rosaria; Schimmenti, Vittoria; Lalueza-Fox, Carles; Messina, Andrea; Petruso, Daria; Caramelli, David; Richards, Michael P.; Sineo, Luca

2012-01-01

Hunter-gatherers living in Europe during the transition from the late Pleistocene to the Holocene intensified food acquisition by broadening the range of resources exploited to include marine taxa. However, little is known on the nature of this dietary change in the Mediterranean Basin. A key area to investigate this issue is the archipelago of the Ègadi Islands, most of which were connected to Sicily until the early Holocene. The site of Grotta d’Oriente, on the present-day island of Favignana, was occupied by hunter-gatherers when Postglacial environmental changes were taking place (14,000-7,500 cal BP). Here we present the results of AMS radiocarbon dating, palaeogenetic and isotopic analyses undertaken on skeletal remains of the humans buried at Grotta d’Oriente. Analyses of the mitochondrial hypervariable first region of individual Oriente B, which belongs to the HV-1 haplogroup, suggest for the first time on genetic grounds that humans living in Sicily during the early Holocene could have originated from groups that migrated from the Italian Peninsula around the Last Glacial Maximum. Carbon and nitrogen isotope analyses show that the Upper Palaeolithic and Mesolithic hunter-gatherers of Favignana consumed almost exclusively protein from terrestrial game and that there was only a slight increase in marine food consumption from the late Pleistocene to the early Holocene. This dietary change was similar in scale to that at sites on mainland Sicily and in the rest of the Mediterranean, suggesting that the hunter-gatherers of Grotta d’Oriente did not modify their subsistence strategies specifically to adapt to the progressive isolation of Favignana. The limited development of technologies for intensively exploiting marine resources was probably a consequence both of Mediterranean oligotrophy and of the small effective population size of these increasingly isolated human groups, which made innovation less likely and prevented transmission of fitness

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...

A framework model for water-sharing among co-basin states of a river basin

Science.gov (United States)

Garg, N. K.; Azad, Shambhu

2018-05-01

A new framework model is presented in this study for sharing of water in a river basin using certain governing variables, in an effort to enhance the objectivity for a reasonable and equitable allocation of water among co-basin states. The governing variables were normalised to reduce the governing variables of different co-basin states of a river basin on same scale. In the absence of objective methods for evaluating the weights to be assigned to co-basin states for water allocation, a framework was conceptualised and formulated to determine the normalised weighting factors of different co-basin states as a function of the governing variables. The water allocation to any co-basin state had been assumed to be proportional to its struggle for equity, which in turn was assumed to be a function of the normalised discontent, satisfaction, and weighting factors of each co-basin state. System dynamics was used effectively to represent and solve the proposed model formulation. The proposed model was successfully applied to the Vamsadhara river basin located in the South-Eastern part of India, and a sensitivity analysis of the proposed model parameters was carried out to prove its robustness in terms of the proposed model convergence and validity over the broad spectrum values of the proposed model parameters. The solution converged quickly to a final allocation of 1444 million cubic metre (MCM) in the case of the Odisha co-basin state, and to 1067 MCM for the Andhra Pradesh co-basin state. The sensitivity analysis showed that the proposed model's allocation varied from 1584 MCM to 1336 MCM for Odisha state and from 927 to 1175 MCM for Andhra, depending upon the importance weights given to the governing variables for the calculation of the weighting factors. Thus, the proposed model was found to be very flexible to explore various policy options to arrive at a decision in a water sharing problem. It can therefore be effectively applied to any trans-boundary problem where

The history of brucellosis in the Pacific Island Countries and Territories and its re-emergence.

Science.gov (United States)

Tukana, Andrew; Warner, Jeffrey; Hedlefs, Robert; Gummow, Bruce

2015-11-01

There are few publications on brucellosis within the Pacific Island Countries and Territories (PICTs). The reason is possibly because the cattle population has been reportedly free of the disease for many years until a re-emergence occurred in the Fiji Islands (Viti Levu) in 2009. This paper reports on the outbreak of brucellosis in Fiji and its progression between 2009 and 2013 in the context of an overview of brucellosis in the Pacific Island community. Review of the literature found only 28 articles with the oldest record of brucellosis being in 1965 in Papua New Guinea (PNG) and from human cases in Tonga in 1980. The Fiji outbreak of Brucella abortus occurred in cattle in 2009 (Wainivesi basin) in the Tailevu province. Prior to the outbreak, Fiji declared freedom from B. abortus to OIE in 1996 after a successful eradication campaign. During the course of the outbreak investigation, serum samples were collected from between 9790 and 21,624 cattle per annum between 2009 and 2013 from 87 farms on the main island of Fiji (Viti Levu). Blood samples were tested for brucellosis using the Rose Bengal Test (RBT) in 2009 and the indirect ELISA test in subsequent years. At the time of the outbreak in Fiji (2009) the apparent prevalence in cattle was 1.50% and this has fluctuated since the outbreak. The True Prevalence (TP) for the main island in Fiji for the indirect ELISA tests was 2.40% in 2010, reached a peak of 3.49% in 2011 then reduced to 0.12% by 2013. The significant reduction in prevalence compared to 2010 is most likely due to the control programs being implemented in Fiji. The re-emergence of B. abortus in Fiji could be attributed to the lack of monitoring for the disease until 2009 combined with inadequate management of exposed animals, thus illustrating how important it is for authorities not to become complacent. Continued awareness and monitoring for brucellosis is essential if future outbreaks are to be avoided. Copyright © 2015 Elsevier B.V. All rights

Experimental Evaluation of PV Inverter Anti-Islanding with Grid Support Functions in Multi-Inverter Island Scenarios

Energy Technology Data Exchange (ETDEWEB)

Hoke, Anderson [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Brian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bell, Frances [SolarCity, San Mateo, CA (United States); McCarty, Michael [SolarCity, San Mateo, CA (United States)

2016-07-01

As PV and other DER systems are connected to the grid at increased penetration levels, island detection may become more challenging for two reasons: 1.) In islands containing many DERs, active inverter-based anti-islanding methods may have more difficulty detecting islands because each individual inverter's efforts to detect the island may be interfered with by the other inverters in the island. 2.) The increasing numbers of DERs are leading to new requirements that DERs ride through grid disturbances and even actively try to regulate grid voltage and frequency back towards nominal operating conditions. These new grid support requirements may directly or indirectly interfere with anti-islanding controls. This report describes a series of tests designed to examine the impacts of both grid support functions and multi-inverter islands on anti-islanding effectiveness. Crucially, the multi-inverter anti-islanding tests described in this report examine scenarios with multiple inverters connected to multiple different points on the grid. While this so-called 'solar subdivision' scenario has been examined to some extent through simulation, this is the first known work to test it using hardware inverters. This was accomplished through the use of power hardware-in-the-loop (PHIL) simulation, which allows the hardware inverters to be connected to a real-time transient simulation of an electric power system that can be easily reconfigured to test various distribution circuit scenarios. The anti-islanding test design was a modified version of the unintentional islanding test in IEEE Standard 1547.1, which creates a balanced, resonant island with the intent of creating a highly challenging condition for island detection. Three common, commercially available single-phase PV inverters from three different manufacturers were tested. The first part of this work examined each inverter individually using a series of pure hardware resistive-inductive-capacitive (RLC

Late Glacial and Holocene Climate Change in the subantarctic Auckland Islands

Science.gov (United States)

Gilmer, G.; Moy, C. M.; Vandergoes, M.; Gadd, P.; Riesselman, C. R.; Jacobsen, G. E.; Wilson, G. S.; Visinand, C.

2017-12-01

Situated within the core of the Southern Hemisphere westerly winds, and between the subtropical and subantarctic fronts, the New Zealand subantarctic islands are uniquely positioned to evaluate past ocean and atmospheric change in the middle to high southern latitudes. We collected a series of sediment cores from Auckland Island fjords to produce a high-resolution record of climate change following the Last Glacial Maximum. Physical property and organic geochemical data, Itrax XRF, and visual core descriptions indicate the cores capture several phases of sedimentation. From these studies, we identify four primary sedimentary facies: 1) a deglacial facies exhibiting mm-scale laminae defined by magnetic susceptibility and density contrasts and high counts of elements associated with terrigenous sources; 2) a lacustrine facies defined by very low density, high organic carbon concentrations and low counts of lithophilic elements; 3) a marine transgression facies with moderate density, moderate bioturbation and alternating marine and lacustrine sedimentary components; 4) a marine facies that contains biogenic carbonate. Radiocarbon results indicate deglacial sedimentation was underway in the basin by approximately 19,000 cal yr BP. Lacustrine deposition in ice-free conditions began around 15,600 cal yr BP and continued until marine transgression at approximately 9,500 cal yr BP. During the early Holocene between 11 and 9.5 ka, we observe elevated n-alkane δD values and an overall increase in redox-sensitive elements that signal a combination of warmer atmospheric temperatures and reduced westerly wind strength that drives fjord stratification. Poleward-shifted westerlies south of the Auckland Islands could accommodate these results, but there are few records to corroborate this interpretation. We will discuss these results within the context of developing New Zealand and subantarctic paleoclimate records in order to provide a more comprehensive record of past change.

Gravity anomalies of the Northern Hawaiian Islands: Implications on the shield evolutions of Kauai and Niihau

Science.gov (United States)

Flinders, Ashton F.; Ito, Garrett; Garcia, Michael O.

2010-08-01

New land and marine gravity data reveal two positive residual gravity anomalies in the Northern Hawaiian Islands: one over Kaua'i, the other between the islands of Kaua'i and Ni'ihau. These gravitational highs are similar in size and magnitude to those of other Hawaiian volcanoes, indicating local zones of high-density crust, attributed to olivine cumulates in solidified magma reservoirs. The residual gravity high over Kaua'i is located in the Līhu'e Basin, offset 8-12 km east of Kaua'i's geologically mapped caldera. This offset suggests that the mapped caldera is a collapsed feature later filled in with lava and not the long-term center of Kaua'i shield volcanism. A second residual gravity high, in the submarine channel between Kaua'i and Ni'ihau, marks the volcanic center of the Ni'ihau shield volcano. This second residual gravity anomaly implies that Ni'ihau's eastern boundary extended ˜20 km east of its present location. Through inversion, the residual gravity anomalies were modeled as being produced by two solidified magma reservoirs with average densities of 3100 kg/m3 and volumes between 2470 and 2540 km3. Considering the locations and sizes of the residual gravity anomalies/magma reservoirs, the extent of the two islands' paleoshorelines and potassium-argon dating of shield-stage lavas, we conclude that the two islands were not connected subaerially during their respective shield stages and that Ni'ihau's topographic summit was removed by an eastern flank collapse between 4.3 and 5.6 Ma. Continued constructional volcanism on western Kaua'i likely covered much of the submerged remains of eastern Ni'ihau.

Gridded multibeam bathymetry of Baker 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 Baker Island, within the Pacific Remote Island Areas - Central Pacific Ocean. Bottom coverage was achieved in depths...

Vegetation assessment of forests of Pagan Island, Commonwealth of the Northern Mariana Islands

Science.gov (United States)

Pratt, Linda W.

2011-01-01

As part of the Marianas Expedition Wildlife Surveys-2010, the forest vegetation of the island of Pagan, Commonwealth of the Northern Mariana Islands (CNMI), was sampled with a series of systematic plots along 13 transects established for monitoring forest bird populations. Shrubland and grassland were also sampled in the northern half of the island. Data collected were woody plant density, tree diameter at breast height, woody plant density in height classes below 2 m, and ground cover measured with the point-intercept method. Coconut forests (Cocos nucifera) were generally found to have low native tree diversity, little regeneration of trees and shrubs in the forest understory, and little live ground cover. The sole exception was a coconut-dominated forest of the northeast side of the island that exhibited high native tree diversity and a large number of young native trees in the understory. Ironwood (Casuarina equisetifolia) forests on the northern half of the island were nearly monocultures with almost no trees other than ironwood in vegetation plots, few woody plants in the understory, and low ground cover dominated by native ferns. Mixed native forests of both northern and southern sections of the island had a diversity of native tree species in both the canopy and the sparse understory. Ground cover of native forests in the north had a mix of native and alien species, but that of the southern half of the island was dominated by native ferns and woody plants.

Island biogeography of marine organisms

Science.gov (United States)

Pinheiro, Hudson T.; Bernardi, Giacomo; Simon, Thiony; Joyeux, Jean-Christophe; Macieira, Raphael M.; Gasparini, João Luiz; Rocha, Claudia; Rocha, Luiz A.

2017-09-01

Studies on the distribution and evolution of organisms on oceanic islands have advanced towards a dynamic perspective, where terrestrial endemicity results from island geographical aspects and geological history intertwined with sea-level fluctuations. Diversification on these islands may follow neutral models, decreasing over time as niches are filled, or disequilibrium states and progression rules, where richness and endemism rise with the age of the archipelago owing to the splitting of ancestral lineages (cladogenesis). However, marine organisms have received comparatively little scientific attention. Therefore, island and seamount evolutionary processes in the aquatic environment remain unclear. Here we analyse the evolutionary history of reef fishes that are endemic to a volcanic ridge of seamounts and islands to understand their relations to island evolution and sea-level fluctuations. We also test how this evolutionary history fits island biogeography theory. We found that most endemic species have evolved recently (Pleistocene epoch), during a period of recurrent sea-level changes and intermittent connectivity caused by repeated aerial exposure of seamounts, a finding that is consistent with an ephemeral ecological speciation process. Similar to findings for terrestrial biodiversity, our data suggest that the marine speciation rate on islands is negatively correlated with immigration rate. However, because marine species disperse better than terrestrial species, most niches are filled by immigration: speciation increases with the random accumulation of species with low dispersal ability, with few opportunities for in situ cladogenesis and adaptive radiation. Moreover, we confirm that sea-level fluctuations and seamount location play a critical role in marine evolution, mainly by intermittently providing stepping stones for island colonization.

Basins in ARC-continental collisions

Science.gov (United States)

Draut, Amy E.; Clift, Peter D.; Busby, Cathy; Azor, Antonio

2012-01-01

Arc-continent collisions occur commonly in the plate-tectonic cycle and result in rapidly formed and rapidly collapsing orogens, often spanning just 5-15 My. Growth of continental masses through arc-continent collision is widely thought to be a major process governing the structural and geochemical evolution of the continental crust over geologic time. Collisions of intra-oceanic arcs with passive continental margins (a situation in which the arc, on the upper plate, faces the continent) involve a substantially different geometry than collisions of intra-oceanic arcs with active continental margins (a situation requiring more than one convergence zone and in which the arc, on the lower plate, backs into the continent), with variable preservation potential for basins in each case. Substantial differences also occur between trench and forearc evolution in tectonically erosive versus tectonically accreting margins, both before and after collision. We examine the evolution of trenches, trench-slope basins, forearc basins, intra-arc basins, and backarc basins during arc-continent collision. The preservation potential of trench-slope basins is low; in collision they are rapidly uplifted and eroded, and at erosive margins they are progressively destroyed by subduction erosion. Post-collisional preservation of trench sediment and trench-slope basins is biased toward margins that were tectonically accreting for a substantial length of time before collision. Forearc basins in erosive margins are usually floored by strong lithosphere and may survive collision with a passive margin, sometimes continuing sedimentation throughout collision and orogeny. The low flexural rigidity of intra-arc basins makes them deep and, if preserved, potentially long records of arc and collisional tectonism. Backarc basins, in contrast, are typically subducted and their sediment either lost or preserved only as fragments in melange sequences. A substantial proportion of the sediment derived from

Volcanism in the Bransfield Strait, Antarctica

Science.gov (United States)

Fisk, M. R.

Back-arc and marginal basins make up a significant portion of the earth's crust and they can represent the transition from continental to oceanic crust. The Bransfield Strait is a young marginal basin of the arc-trench system that lies off the northwestern edge of the Antarctic Peninsula. The strait is about 65 km wide and has a maximum water depth of 2000 m. "Active" volcanoes in the Bransfield Strait include two seamounts, which are south of the eastern end of King George Island, and three island volcanoes — Penguin, Deception, and Bridgeman Islands. Alkaline and calc-alkaline suites occur on these islands, and the seamounts are composed of tholeiites and basaltic andesites. This diversity is similar to that found in some back-arc basins, but the Bransfield Strait basalts as a group cannot be classified as back-arc basin or island-arc basalts. The diverse rock types and the chemical similarity of some of the Bransfield Strait basalts to ophiolite basalts suggests that some ophiolites were generated in back-arc basins.

Interaction of bootstrap-current-driven magnetic islands

International Nuclear Information System (INIS)

Hegna, C.C.; Callen, J.D.

1991-10-01

The formation and interaction of fluctuating neoclassical pressure gradient driven magnetic islands is examined. The interaction of magnetic islands produces a stochastic region around the separatrices of the islands. This interaction causes the island pressure profile to be broadened, reducing the island bootstrap current and drive for the magnetic island. A model is presented that describes the magnetic topology as a bath of interacting magnetic islands with low to medium poloidal mode number (m congruent 3-30). The islands grow by the bootstrap current effect and damp due to the flattening of the pressure profile near the island separatrix caused by the interaction of the magnetic islands. The effect of this sporadic growth and decay of the islands (''magnetic bubbling'') is not normally addressed in theories of plasma transport due to magnetic fluctuations. The nature of the transport differs from statistical approaches to magnetic turbulence since the radial step size of the plasma transport is now given by the characteristic island width. This model suggests that tokamak experiments have relatively short-lived, coherent, long wavelength magnetic oscillations present in the steep pressure-gradient regions of the plasma. 42 refs

Some data on the avifauna of the Island of Roti, Lesser Sunda Islands, Indonesia

NARCIS (Netherlands)

Verheijen, J.A.J.

1976-01-01

INTRODUCTION For several years I had been looking for an opportunity to visit the island of Roti (Rotti, Roté, Loté). Junge (1954) mentions that only once an ornithological collection was made in the island, namely by Dr. H. F. C. ten Kate, an ethnologist who visited the island in 1891. Büttikofer

Islanded operation of distribution networks

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This report summarises the results of a study assessing the benefits and risks to distribution network of generator islanding and examining the technical, commercial and regulatory changes required to facilitate the operation of islanding. The background to the study is traced, and details are given of a literature review, the technical criteria for operating sections of the network in islanding mode, and the impact of islanding on trading. Case studies and a detailed implementation plan, data acquisition, and commercial incentives are discussed.

Islanded operation of distribution networks

International Nuclear Information System (INIS)

2005-01-01

This report summarises the results of a study assessing the benefits and risks to distribution network of generator islanding and examining the technical, commercial and regulatory changes required to facilitate the operation of islanding. The background to the study is traced, and details are given of a literature review, the technical criteria for operating sections of the network in islanding mode, and the impact of islanding on trading. Case studies and a detailed implementation plan, data acquisition, and commercial incentives are discussed

HYDROGEOLOGICAL RELATIONS ON KARSTIFIED ISLANDS - VIS ISLAND CASE STUDY

Directory of Open Access Journals (Sweden)

Josip Terzić

2004-12-01

Full Text Available An approach to the hydrogeological investigations on Adriatic islands is presented on the Island of Vis case study. Infiltration, accumulation and discharge of the groundwater occur in karstified rock mass. Hydrogeological relations are mostly a consequence of the geological setting, because of the complete hydrogeologic barrier in Komiža bay, and relative barrier in the area of karst poljes. Significant research was performed in the 1999 – 2000 period aimed of better understanding of hydrogeological relations. These investigations, as well as reinterpretation of some previously known data, included structural geology, hydrogeology, hydrology and hydrochemistry. Approximate rock mass hydraulic conductivity calculation is also shown, as well as level of its usability in such terrain. Based on all these methods, it is possible to conclude that on the Island of Vis there is no saline water present underneath the entire island. There is only a saline water wedge which is formed on the top of relatively impermeable base rock, some few tens of meters under recent sea level. With such a model, and taking in account the hydrological balance, it is possible to conclude that there is possibility of higher amount of groundwater exploitation then it is today (the paper is published in Croatian.

Provenance and detrital zircon geochronologic evolution of lower Brookian foreland basin deposits of the western Brooks Range, Alaska, and implications for early Brookian tectonism

Science.gov (United States)

Moore, Thomas; O'Sullivan, Paul B.; Potter, Christopher J.; Donelick, Raymond A.

2015-01-01

detritus to the early Brookian foreland basin of the western Brooks Range: (1) local sources in the oceanic Angayucham terrane, which forms the upper plate of the orogen, and (2) a sedimentary source region outside of northern Alaska. Pre-Jurassic zircons and continental grain types suggest the latter detritus was derived from a thick succession of Triassic turbidites in the Russian Far East that were originally shed from source areas in the Uralian-Taimyr orogen and deposited in the South Anyui Ocean, interpreted here as an early Mesozoic remnant basin. Structural thickening and northward emplacement onto the continental margin of Chukotka during the Brookian structural event are proposed to have led to development of a highland source area located in eastern Chukotka, Wrangel Island, and Herald Arch region. The abundance of detritus from this source area in most of the samples argues that the Colville Basin and ancestral foreland basins were supplied by longitudinal sediment dispersal systems that extended eastward along the Brooks Range orogen and were tectonically recycled into the active foredeep as the thrust front propagated toward the foreland. Movement of clastic sedimentary material from eastern Chukotka, Wrangel Island, and Herald Arch into Brookian foreland basins in northern Alaska confirms the interpretations of previous workers that the Brookian deformational belt extends into the Russian Far East and demonstrates that the Arctic Alaska–Chukotka microplate was a unified geologic entity by the Early Cretaceous.

Strategic Environmental Assessment practices in European small islands: Insights from Azores and Orkney islands

Energy Technology Data Exchange (ETDEWEB)

Polido, Alexandra, E-mail: a.polido@campus.fct.unl.pt [CENSE, Center for Environmental and Sustainability Research, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus da Caparica, 2829-516 Caparica (Portugal); João, Elsa, E-mail: elsa.joao@strath.ac.uk [Department of Civil and Environmental Engineering, University of Strathclyde, Level 5, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, Scotland (United Kingdom); Ramos, Tomás B., E-mail: tabr@fct.unl.pt [CENSE, Center for Environmental and Sustainability Research, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus da Caparica, 2829-516 Caparica (Portugal)

2016-02-15

The literature concerning Strategic Environmental Assessment (SEA) often refers to the importance of context-specific approaches. However, there is a lack of systematised and consistent studies that enhance tailor-made SEA practices and procedures. Small islands are bounded units of study which may help explore SEA theory and practice in special territories. Small islands present particular features and unique values, such as, small size and population, geographic isolation, limited resources and vulnerable ecosystems. Hence, the main goal of this research was to profile SEA practices and procedures in European small islands and provide a background for future research aiming to improve context-specific SEA applications. To achieve this goal, an exploratory case study was developed using Azores (Portugal) and Orkney (Scotland) archipelagos. An analysis of the corresponding mainland was also carried out to contextualise both case studies. The data collection was achieved through a qualitative content analysis of 43 Environmental Reports. The research found that there is not an SEA context-specific approach used within these European small islands, including guidelines, assessment topics, assessment techniques, follow-up and stakeholders engagement. The debate concerning specific approaches to small islands must be re-focused on the enhancement of SEA capacity-building amongst different stakeholders (including decision-makers), on the development and implementation of collaborative approaches, and on the exchange of knowledge and experiences between small islands networks. - Highlights: • Reviewed the differences between the Portuguese and Scottish SEA system • Showed a low integration of SEA specific features in reports of European small islands • Provides background for future SEA research for small islands approaches.

Strategic Environmental Assessment practices in European small islands: Insights from Azores and Orkney islands

International Nuclear Information System (INIS)

Polido, Alexandra; João, Elsa; Ramos, Tomás B.

2016-01-01

The literature concerning Strategic Environmental Assessment (SEA) often refers to the importance of context-specific approaches. However, there is a lack of systematised and consistent studies that enhance tailor-made SEA practices and procedures. Small islands are bounded units of study which may help explore SEA theory and practice in special territories. Small islands present particular features and unique values, such as, small size and population, geographic isolation, limited resources and vulnerable ecosystems. Hence, the main goal of this research was to profile SEA practices and procedures in European small islands and provide a background for future research aiming to improve context-specific SEA applications. To achieve this goal, an exploratory case study was developed using Azores (Portugal) and Orkney (Scotland) archipelagos. An analysis of the corresponding mainland was also carried out to contextualise both case studies. The data collection was achieved through a qualitative content analysis of 43 Environmental Reports. The research found that there is not an SEA context-specific approach used within these European small islands, including guidelines, assessment topics, assessment techniques, follow-up and stakeholders engagement. The debate concerning specific approaches to small islands must be re-focused on the enhancement of SEA capacity-building amongst different stakeholders (including decision-makers), on the development and implementation of collaborative approaches, and on the exchange of knowledge and experiences between small islands networks. - Highlights: • Reviewed the differences between the Portuguese and Scottish SEA system • Showed a low integration of SEA specific features in reports of European small islands • Provides background for future SEA research for small islands approaches

Rift systems of the Russian Eastern Arctic shelf and Arctic deep water basins: link between geological history and geodynamics

Directory of Open Access Journals (Sweden)

A. M. Nikishin

2017-01-01

Full Text Available In our study, we have developed a new tectonic scheme of the Arctic Ocean, which is based mainly on seismic profiles obtained in the Arctic-2011, Arctic-2012 and Arctic-2014 Projects implemented in Russia. Having interpreted many seismic profiles, we propose a new seismic stratigraphy of the Arctic Ocean. Our main conclusions are drawn from the interpretation of the seismic profiles and the analysis of the regional geological data. The results of our study show that rift systems within the Laptev, the East Siberian and the Chukchi Seas were formed not earlier than Aptian. The geological structure of the Eurasian, Podvodnikov, Toll and Makarov Basins is described in this paper. Having synthesized all the available data on the study area, we propose the following model of the geological history of the Arctic Ocean: 1. The Canada Basin formed till the Aptian (probably, during Hauterivian-Barremian time. 2. During the Aptian-Albian, large-scale tectonic and magmatic events took place, including plume magmatism in the area of the De Long Islands, Mendeleev Ridge and other regions. Continental rifting started after the completion of the Verkhoyansk-Chukotka orogenу, and rifting occurred on the shelf of the Laptev, East Siberian, North Chukchi and South Chukchi basins, and the Chukchi Plateau; simultaneously, continental rifting started in the Podvodnikov and Toll basins. 3. Perhaps the Late Cretaceous rifting continued in the Podvodnikov and Toll basins. 4. At the end of the Late Cretaceous and Paleocene, the Makarov basin was formed by rifting, although local spreading of oceanic crust during its formation cannot be excluded. 5. The Eurasian Basin started to open in the Early Eocene. We, of course, accept that our model of the geological history of the Arctic Ocean, being preliminary and debatable, may need further refining. In this paper, we have shown a link between the continental rift systems on the shelf and the formation history of the Arctic

Superposition of tectonic structures leading elongated intramontane basin: the Alhabia basin (Internal Zones, Betic Cordillera)

Science.gov (United States)

Martínez-Martos, Manuel; Galindo-Zaldivar, Jesús; Martínez-Moreno, Francisco José; Calvo-Rayo, Raquel; Sanz de Galdeano, Carlos

2017-10-01

The relief of the Betic Cordillera was formed since the late Serravallian inducing the development of intramontane basins. The Alhabia basin, situated in the central part of the Internal Zones, is located at the intersection of the Alpujarran Corridor, the Tabernas basin, both trending E-W, and the NW-SE oriented Gádor-Almería basin. The geometry of the basin has been constrained by new gravity data. The basin is limited to the North by the Sierra de Filabres and Sierra Nevada antiforms that started to develop in Serravallian times under N-S shortening and to the south by Sierra Alhamilla and Sierra de Gádor antiforms. Plate convergence in the region rotated counter-clockwise in Tortonian times favouring the formation of E-W dextral faults. In this setting, NE-SW extension, orthogonal to the shortening direction, was accommodated by normal faults on the SW edge of Sierra Alhamilla. The Alhabia basin shows a cross-shaped depocentre in the zone of synform and fault intersection. This field example serves to constrain recent counter-clockwise stress rotation during the latest stages of Neogene-Quaternary basin evolution in the Betic Cordillera Internal Zones and underlines the importance of studying the basins' deep structure and its relation with the tectonic structures interactions.

Late Quaternary climate change shapes island biodiversity.

Science.gov (United States)

Weigelt, Patrick; Steinbauer, Manuel Jonas; Cabral, Juliano Sarmento; Kreft, Holger

2016-04-07

Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics.

Can Transport of Saharan Dust Explain Extensive Clay Deposits in the Amazon Basin? A Test Using Radiogenic Isotopes

Science.gov (United States)

Andreae, M. O.; Abouchami, W.; Näthe, K.; Kumar, A.; Galer, S. J.; Jochum, K. P.; Williams, E.; Horbe, A. M.; Rosa, J. W.; Adams, D. K.; Balsam, W. R.

2012-12-01

The Bodélé Depression, located in the Southern Sahara, is a huge source of atmospheric dust and thus an important element in biogeochemical cycles and the radiative budget of Earth's atmosphere. Previous studies have shown that Saharan dust transport across the Atlantic acts as an important source of mineral nutrients to the Amazon rainforest. The Belterra Clay, which outcrops extensively across the Amazon Basin in Brazil, has been proposed to result from dry deposition of African dusts. We have investigated this hypothesis by measuring the radiogenic isotopic composition (Sr, Nd and Pb) of a suite of samples from the Belterra Clay, the Bodélé Depression, dusts deposits collected at various locations along the airmass transport trajectory, as well as loess from the Cape Verde Islands. Radiogenic isotope systems are powerful tracers of provenance and can be used to fingerprint dust sources and atmospheric transport patterns. Our results identify distinct isotopic signatures in the Belterra Clay samples and the African sources. The Belterra Clay display radiogenic Sr and Pb isotope ratios associated with non-radiogenic Nd isotope signatures. In contrast, Bodélé samples and dusts deposits show lower Pb isotope ratios, variable 87Sr/86Sr, and relatively homogeneous Nd isotopic compositions, albeit more radiogenic than those of the Belterra Clay. Our data show unambiguously that the Belterra Clay is not derived from African dust deposition, nor from the Andean chain, as originally suggested by W. Sombroek. Rather, isotopic compositions and Nd model ages are consistent with simple mixing of Archean and younger Proterozoic terranes within the Amazon Basin as a result of weathering and erosion under humid tropical conditions. Whether Saharan dusts contribute to the fertilization in the Amazon Basin cannot be ruled out, however, since the African dust isotopic signature is expected to be entirely overprinted by local sources. Radiogenic isotope data obtained on

Virtually Impossible: Deleuze and Derrida on the Political Problem of Islands (and Island Studies

Directory of Open Access Journals (Sweden)

Stewart Williams

2012-11-01

Full Text Available It is commonplace to think of an island as a discreetly bounded unit. Selected writings on islands by the poststructuralist philosophers Gilles Deleuze and Jacques Derrida reveal the island variously to be both real and imaginary, mythological and scientific, but as most problematic when constituted in political terms as an indivisible, sovereign entity. These two thinkers’ more broadly developed concepts of the virtual and the impossible, respectively, are seen to disrupt any assumptions about the fixity and closure of the island polity. Instead they emphasize its actualization through processual relations that can be difficult yet dynamic and decisive in effecting the move from being to becoming-other. As the possibilities for instituting more ethical as well as different political relations open up, the question of island studies remaining in its currently coherent, familiar form is raised for consideration.

Bamboo Diversity in Sumba Island

Directory of Open Access Journals (Sweden)

KARSONO

2005-04-01

Full Text Available Bamboo is one of the economic plant which grow widely in the villages and have been used by the local people in the villages. Indonesia has about 10% of the world bamboo, 50% among them was endemic to Indonesia. According Widjaja (2001 Lesser Sunda Island which consists of Lombok, Sumbawa, Flores, Timor, Sumba and other small island eastern of Flores has 14 bamboo species, however, the information from the Sumba Island was lacking because of lacking data from this area except one species which was proposed by S. Soenarko in 1977 where the type specimens was collected by Iboet 443 in 1925. To fullfill data from the Sumba Island, an exploration to this area has been conducted on July 2003. The observation was done in West Sumba and East Sumba District, especially in two natioal parks at both districts. According to this inventory study in the Sumba Island, there were 10 bamboo species in Sumba Island, 1 species among them (Dinochloa sp. was a new species which has not been collected before, whereas the other species (Dinochloa kostermansiana has a new addition record from this area. The bamboo species in Sumba Island were Bambusa blumeana, Bambusa vulgaris, Dendocalamus asper, Dinochloa kostermansiana, Dinochloa sp., Gigantochloa atter, Nastus reholtumianus, Phyllostachys aurea, Schisotachyum brachycladum and Schizostachyum lima. From 10 recorded species, the genera Dinochloa and Nastus grow wild in the forest, whereas another species grow widly or cultivated in the garden. Furthermore, the genus Dinochloa was the only genus grow climbing. The endemic species found in Sumba Island was Nastus reholttumianus, whereas Dinochloa kostermansiana was also found in Flores Island.

Biological invasions on oceanic islands: Implications for island ecosystems and avifauna

Science.gov (United States)

Dean E. Pearson

2009-01-01

Biological invasions present a global threat to biodiversity, but oceanic islands are the systems hardest hit by invasions. Islands are generally depauperate in species richness, trophic complexity, and functional diversity relative to comparable mainland ecosystems. This situation results in low biotic resistance to invasion and many empty niches for invaders to...

Oak restoration trials: Santa Catalina Island

Science.gov (United States)

Lisa Stratton

2002-01-01

Two restoration trials involving four oak species have been implemented as part of a larger restoration program for Catalina Island. In 1997 the Catalina Island Conservancy began an active program of restoration after 50 years of ranching and farming activities on the island. The restoration program includes removing feral goats and pigs island-wide and converting 80...

Island history affects faunal composition: the treeshrews (Mammalia: Scandentia: Tupaiidae) from the Mentawai and Batu Islands, Indonesia

Science.gov (United States)

Sargis, Eric J.; Woodman, Neal; Morningstar, Natalie C.; Reese, Aspen T.; Olson, Link E.

2014-01-01

The Mentawai and Batu Island groups off the west coast of Sumatra have a complicated geological and biogeographical history. The Batu Islands have shared a connection with the Sumatran ‘mainland’ during periods of lowered sea level, whereas the Mentawai Islands, despite being a similar distance from Sumatra, have remained isolated from Sumatra, and probably from the Batu Islands as well. These contrasting historical relationships to Sumatra have influenced the compositions of the respective mammalian faunas of these island groups. Treeshrews (Scandentia, Tupaiidae) from these islands have, at various times in their history, been recognized as geographically circumscribed populations of a broadly distributed Tupaia glis, subspecies, or distinct species. We used multivariate analyses of measurements from the skull and hands to compare the island populations from Siberut (Mentawai Islands) and Tanahbala (Batu Islands) with the geographically adjacent species from the southern Mentawai Islands (T. chrysogaster) and Sumatra (T. ferruginea). Results from both the skull and manus of the Siberut population show that it is most similar to T. chrysogaster, whereas the Tanahbala population is more similar to T. ferruginea, confirming predictions based on island history. These results are further corroborated by mammae counts. Based on these lines of evidence, we include the Siberut population in T. chrysogaster and the Tanahbala population in T. ferruginea. Our conclusions expand the known distributions of both the Mentawai and Sumatran species. The larger geographical range of the endangered T. chrysogaster has conservation implications for this Mentawai endemic, so populations and habitat should be re-evaluated on each of the islands it inhabits. However, until such a re-evaluation is conducted, we recommend that the IUCN Red List status of this species be changed from ‘Endangered’ to ‘Data Deficient’.

Sable Island: A heritage to preserve

Energy Technology Data Exchange (ETDEWEB)

Villeneuve, C.

1997-09-01

Sable Island is strategically located on the edge of the teeming fisheries of the Newfoundland Grand Banks and near one of the main sea routes between North America and Europe. It has been the bane of navigators from 1583 onward, with 250 ships running aground, the latest in 1947. Marine productivity around Sable Island is very high owing to the temperature differences between the currents and the adjacent underwater topography. Dolphins and whales abound in the area known as the `Gully`, and there are no fewer than 36 fish species present in the waters surrounding the Island. Approximately 35 per cent of the Island is covered by vegetation which is limited to species adapted to sandy soil containing little organic matter and few nutrients. Some plants, such as the American beachgrass, grow in dense colonies and help to stabilize the dunes. Bird diversity is limited to species adapted to open areas, ponds and the littoral. Some 324 species have been recorded on the Island, but only 25 are known to nest there. The Island is one of world`s most important breeding sites for grey seals where they can be observed in great numbers during mating, whelping and moulting season. Among the many introduced animals only the legendary horses of Sable Island remain to this day. Despite its remoteness and isolation, the Island faces many threats, one of the most worrysome being the erosion of the eastern extremity of the Island during severe winter storms. The Island benefits from its status as a Migratory Bird Sanctuary, and is legally protected under Sable Island Regulations of the Navigation Act.

SimBasin: serious gaming for integrated decision-making in the Magdalena-Cauca basin

Science.gov (United States)

Craven, Joanne; Angarita, Hector; Corzo, Gerald

2016-04-01

The Magdalena-Cauca macrobasin covers 24% of the land area of Colombia, and provides more than half of the country's economic potential. The basin is also home a large proportion of Colombia's biodiversity. These conflicting demands have led to problems in the basin, including a dramatic fall in fish populations, additional flooding (such as the severe nationwide floods caused by the La Niña phenomenon in 2011), and habitat loss. It is generally believed that the solution to these conflicts is to manage the basin in a more integrated way, and bridge the gaps between decision-makers in different sectors and scientists. To this end, inter-ministerial agreements are being formulated and a decision support system is being developed by The Nature Conservancy Colombia. To engage stakeholders in this process SimBasin, a "serious game", has been developed. It is intended to act as a catalyst for bringing stakeholders together, an illustration of the uncertainties, relationships and feedbacks in the basin, and an accessible introduction to modelling and decision support for non-experts. During the game, groups of participants are led through a 30 year future development of the basin, during which they take decisions about the development of the basin and see the impacts on four different sectors: agriculture, hydropower, flood risk, and environment. These impacts are displayed through seven indicators, which players should try to maintain above critical thresholds. To communicate the effects of uncertainty and climate variability, players see the actual value of the indicator and also a band of possible values, so they can see if their decisions have actually reduced risk or if they just "got lucky". The game works as a layer on top of a WEAP water resources model of the basin, adapted from a basin-wide model already created, so the fictional game basin is conceptually similar to the Magdalena-Cauca basin. The game is freely available online, and new applications are being

Islanded operation of distributed networks

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This report summarises the findings of a study to investigate the regulatory, commercial and technical risks and benefits associated with the operation of distributed generation to power an islanded section of distributed network. A review of published literature was carried out, and UK generators were identified who could operate as part of an island network under the existing technical, regulatory, and safety framework. Agreement on case studies for consideration with distributed network operators (DNOs) is discussed as well as the quantification of the risks, benefits and costs of islanding, and the production of a case implementation plan for each case study. Technical issues associated with operating sections of network in islanded mode are described, and impacts of islanding on trading and settlement, and technical and commercial modelling are explored.

Islanded operation of distributed networks

International Nuclear Information System (INIS)

2005-01-01

This report summarises the findings of a study to investigate the regulatory, commercial and technical risks and benefits associated with the operation of distributed generation to power an islanded section of distributed network. A review of published literature was carried out, and UK generators were identified who could operate as part of an island network under the existing technical, regulatory, and safety framework. Agreement on case studies for consideration with distributed network operators (DNOs) is discussed as well as the quantification of the risks, benefits and costs of islanding, and the production of a case implementation plan for each case study. Technical issues associated with operating sections of network in islanded mode are described, and impacts of islanding on trading and settlement, and technical and commercial modelling are explored

Coastal groundwater exchange on a small Pacific atoll island: Roi Namur, Republic of the Marshall Islands

Science.gov (United States)

Oberle, Ferdinand K. J.; Swarzenski, Peter W.; Storlazzi, Curt

2017-04-01

Atoll islands, most of which only average 1-2 meters above today's sea level, provide a tremendous natural laboratory in which to study and better understand the intensifying impacts of high rates of sea-level rise on tropical reef-lined islands globally due to their unique geologic structure and limited water supply. Groundwater resources of atolls are typically minimal due to the low elevation and small surface area of the islands and are also subject to recurring droughts, and more frequent, storm-driven seawater overwash events. Although groundwater is the principal means of freshwater storage on atoll islands and is a major factor in determining the overall sustainability of island communities, hydrological data on how an aquifer will response to changes in sea-level rise or storm-driven overwash remain limited. We here present high-resolution time series hydrogeological and geochemical data to determine the role of the atoll's carbonate geology, land use, and atmospheric and oceanographic forcing in driving coastal groundwater exchange on the island of Roi Namur on Kwajalein Atoll in the Republic of the Marshall Islands. This information can provide new estimates on the recovery and resilience of coastal groundwater resources on such islands to expected climate change-driven perturbations.

The coastline remote sensing survey for Zhao Shu Island in Xisha Islands based on WorldView-2

Science.gov (United States)

Li, Li; Zhong, Chang; Kong, Fanping

2014-11-01

Due to diastrophism, tide action and human activities, the coastline is always in flux. There are lots of coral islands in the south sea of China. Remote sensing survey for the coastline not only can reassert the necessity and importance of coral protection, but also can provide basic data and scientific basis for island ecologic protection, reasonable utilization of land resources. The study area named Zhao Shu Island lies in Jintong Islands of Xisha. It is a coral island which has people inhabited. Using WorldView-2 satellite remote sensing images as data sources we carry out three phases of coastline investigation and monitoring. The satellite data phases are 2002, 2010 and 2013. Firstly, affirm the bands valuable for color composition on the basis of spectral and correlation analysis. Then extract the coastline by a series of image process, such as image correction, fusion, waterline extraction and coastline revision. Finally determine the coastline types and length by artificial interpretation. The results show that the island length is gradually smaller, which means the island area is reducing. The beach bedrock coast in northern island was eroded seriously especially during the period between 2010 and 2013. In addition, the shoal head shape in the western island changed a lot.

Magmatic versus tectonic influence in the Eolian arc: the case of Vulcano and Lipari islands revisited

Science.gov (United States)

Ruch, Joel; Di Lorenzo, Riccardo; Vezzoli, Luigina Maria; De Rosa, Rosanna; Acocella, Valerio; Catalano, Stefano; Romagnoli, Gino

2014-05-01

The prevalent influence of magma versus tectonics for the edification and the evolution of volcanic zones is matter of debate. Here we focus on Vulcano and Lipari, two active volcanic islands located in the central sector of the Eolian arc (North of Sicily). Both systems are influenced by regional tectonics and affected by historical magmatic events taking place along a NS oriented structure, connecting both islands. We revisit and implement previous structural studies performed during the 1980's considering several new geophysical, geochemical and geodynamical findings. Four extensive structural campaigns have been performed on both islands and along the shorelines in 2012-2013 covering about 80% of the possible accessible outcrops. We collected ~500 measurements (e.g. faults, fractures and dikes) at 40 sites. Overall, most of the observed structures are oriented N-S and NNW-SSE, confirming previous studies, however, almost all features are strikingly dominated by an EW-oriented extensive regime, which is a novelty. These findings are supported by kinematic indicators and suggest a predominant dip-slip component (pitch from 80 and 130°) with alternating left and right kinematics. Marginal faulting in most recent formations have been observed, suggesting that the deformation may occur preferentially during transient deformation related to periods of magmatic activity, instead of resulting from continuous regional tectonic processes. Overall, fault and dike planes are characterized by a dominant eastward immersion, suggesting an asymmetric graben-like structure of the entire area. This may be explained by the presence of a topographic gradient connecting both islands to the deep Gioia basin to the East, leading to a preferential ample gravitational collapse. Finally, we propose a model in which the stress field rotates northward. It transits from a pure right lateral strike-slip regime along the Tindari fault zone (tectonic-dominant) to an extensive regime

Proposing offshore photovoltaic (PV) technology to the energy mix of the Maltese islands

International Nuclear Information System (INIS)

Trapani, Kim; Millar, Dean L.

2013-01-01

Highlights: ► Significant cost and carbon savings for offshore PV integration. ► Maximum savings at circa 315 MW for thin film PV integration. ► Minimum generating capacity of turbines significant in cost of electricity. ► Part-load efficiencies of current system could hugely limit the integration of renewables. - Abstract: The islands of Malta are located in the Mediterranean basin enjoying 5.3 kW h/m 2 /day of solar insolation, at a latitude of 35°50N. Electricity generation for the islands is dependent upon imported fossil fuels for combustion. The available solar resource could be exploited to offset the current generation of electricity using solar photovoltaic technology (PV). Due to the limited land availability onshore, the offshore environment surrounding the Maltese islands were considered for the installation of PV floating on the sea surface. The output from such an installation would have to be integrated with the existing conventional electricity generation infrastructure, which currently relies on gas and steam turbine technology. To assess the feasibility of floating PV being integrated with the existing fossil plant, monthly trend consumption data for Malta were analysed. The change in gasoil and heavy fuel oil (HFO) consumption resulting from the part load efficiency variation and the displacement of electricity generation from the PVs were estimated. A cost analysis was prepared for the system integration analysis specifically accounting for the reduction in combustion of fossil fuels at the power station and the capital expenditures and operating costs due to the floating PV installation. Aside from the basic cost-benefit of a floating PV installation, CO 2 savings are also considered

Relating petroleum system and play development to basin evolution: West African South Atlantic basins

NARCIS (Netherlands)

Beglinger, S.E.; Doust, H.; Cloetingh, S.A.P.L.

2012-01-01

Sedimentary basins can be classified according to their structural genesis and evolutionary history and the latter can be linked to petroleumsystem and playdevelopment. We propose an approach in which we use the established concepts in a new way: breaking basins down into their natural basin cycle

Late Quaternary climate change shapes island biodiversity

DEFF Research Database (Denmark)

Weigelt, Patrick; Steinbauer, Manuel; Cabral, Juliano

2016-01-01

Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration–extinction dynamics1, or as geologically dynamic with biodiversity resulting from immigration–speciation–extinction dynamics influenced by changes in island...... sea levels3, 4 and caused massive changes in island area, isolation and connectivity5, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory2, 6. Consequences of these oscillations for present biodiversity remain unassessed5, 7...

Near-Field Population Response During the 2 April 2007 Solomon Islands Tsunami

Science.gov (United States)

McAdoo, B. G.; Moore, A. L.; Baumwoll, J.

2007-12-01

When the magnitude 8.1 earthquake and subsequent tsunami hit the Solomon Islands on 2 April 2007 it killed 52 people. On Ghizo Island, home of the capital of the Western Province, Gizo, waves approaching 4 m in height inundated the south coast villages. Eyewitness accounts supported by geologic data from the offshore coral reef and sediment deposited on land suggest a wave that came in as the shaking stopped as a rapidly-rising tide rather than a turbulent bore- vehicles and houses were floated inland with very little damage. Those that survived in villages affected by the tsunami had indigenous knowledge of prior events, whereas immigrant populations died in higher proportions. While buoy-based early warning systems are necessary to mitigate the effects of teletsunamis, they would have done little good in this near-field environment. In Pailongge, a village of 76 indigenous Solomon Islanders on Ghizo's south coast, there were no deaths. Village elders directed the people inland following the shaking and the almost immediate withdrawal of water from the lagoon, and heads of household made sure that children were accounted for and evacuated. Of the 366 Gilbertese living in Titiana, however, 13 people died, 8 of which were children who were exploring the emptied lagoon. A large proportion of the dead were children (24) as they were likely too weak to swim against the non-bore flow. The Gilbertese migrated from Kiribati in the 1950"s, and had not experienced a major earthquake and tsunami, hence had no cultural memory. In the case of the Solomon Islands tsunami, as was the case in the 2004 Indian Ocean tsunami, indigenous knowledge served the people in the near-field well. In the case of the Indian Ocean where there was 10-20 minutes separation between the time the shaking began and the waves arrived, the combination of an in-place plan and a suitable physical geography allowed the population of Simeulue Island and the Moken people of Thailand to escape before the

Development of Miocene-Pliocene reef trend, St. Croix, U. S. Virgin Islands

Energy Technology Data Exchange (ETDEWEB)

Gill, I.; Eby, D.E.; Hubbard, D.K.; Frost, S.H.

1988-01-01

The Miocene-Pliocene reef trend on St. Croix, U.S. Virgin Islands, rims the present southern western coasts of the island and includes accompanying lagoonal and forereef facies. The reef trend was established on a foram-algal bank facies that represents basinal shallowing from the deep-water pelagic and hemipelagic facies of the Miocene Kingshill Limestone. Information on facies distribution and thickness is derived from rock exposures and 22 test wells drilled to a maximum depth of 91 m. The greatest thickness of the reef facies exists in a subsidiary graben on the south coast of St. Croix. The thickness of the reef section in this locality is due to preservation of the section in a downdropped block. Reef faunas include extant corals, as well as several extinct genera. Extant corals (e.g. Montastrea annularis, Diploria sp., and Porites porites) and extinct corals (e.g., Stylophora affinis, Antillea bilobata, and Thysanus sp.) are the main reef frame-builders. Coralline algea and large benthic foraminifera are significant contributors to the sediments both prior to and during scleractinian reef growth. Dolomitization and calcite cementation occur prominantly in an area corresponding to a Holocene lagoon. The spatial distribution of the dolomite suggests that the lagoon is a Tertiary feature directly related to the dolomitization process. Stable isotopic values suggest dolomitization of fluids of elevated salinity.

Autumn monitoring of resident avifauna on Guana Island, British Virgin Islands

Science.gov (United States)

C.W. Boal; J.M. Wunderle Jr.; W.J. Arendt

2013-01-01

Although the Caribbean region is considered a biodiversity hotspot and a priority for ecological conservation efforts, little information exists on population trends of West Indian landbirds. We combined avian survey data collected from three studies spanning a 16-year period on a small island with a minimal human presence in the British Virgin Islands. Although...

The pacific island health care project.

Science.gov (United States)

Person, Donald Ames

2014-01-01

US Associated/Affiliated Pacific Islands (USAPI) include three freely associated states: Marshall Islands, Federated States of Micronesia, Palau, and three Territories: American Samoa, Guam, and Commonwealth of the Northern Mariana Islands. The Pacific Island Health Care Project (PIHCP) provides humanitarian medical referral/consultation/care to >500,000 indigenous people of these remote islands. In the mid-1990s, we developed a simple store-and-forward program to link the USAPI with Tripler Army Medical Center. This application allowed image attachment to email consultations. More than 8000 Pacific Islanders have benefited from the program. Three thousand Pacific Islanders prior to telemedicine (1990-1997) and since store-and-forward telemedicine (1997-present), the PIHCP has helped an additional 5000. Records post dynamically and are stored in an archival database. The PIHCP is the longest running telemedicine program in the world delivering humanitarian medical care. It has bridged the Developing World of the remote Pacific Islands with advanced medical and surgical care available at a major US military teaching hospital. (The opinions expressed here are those of the author and not that of the Army, Department of Defense, or the US Government.).

The Pacific Island Health Care Project

Directory of Open Access Journals (Sweden)

Donald Ames Person

2014-10-01

Full Text Available Introduction/BackgroundUS Associated/Affiliated Pacific Islands (USAPI include 3 Freely Associated States: Marshall Islands, Federated States of Micronesia, Palau and 3 Territories: American Samoa, Guam, and Commonwealth of the Northern Mariana Islands. ObjectiveThe Pacific Island Health Care Project (PIHCP provides humanitarian medical referral/consultation/care to >500,000 indigenous people of these remote islands. Methods In the mid-1990s, we developed a simple store-and-forward program to link the USAPI with Tripler Army Medical Center (TAMC. This application allowed image attachment to email consultations. ResultsMore than 8000 Pacific Islanders have benefited from the program. 3000 Pacific Islanders prior to telemedicine (1990-1997 and since store-and-forward telemedicine (1997-present, the PIHCP has helped an additional 5000. Records post dynamically and are stored in an archival database. Conclusion The PIHCP is the longest running telemedicine program in the world delivering humanitarian medical care. It has bridged the Developing World of the remote Pacific islands with advanced medical and surgical care available at a major US military teaching hospital.(The opinions expressed here are those of the author and not that of the Army, Department of Defense, or the US Government.

Protecting the Geyser Basins of Yellowstone National Park: Toward a New National Policy for a Vulnerable Environmental Resource

Science.gov (United States)

Barrick, Kenneth A.

2010-01-01

Geyser basins provide high value recreation, scientific, economic and national heritage benefits. Geysers are globally rare, in part, because development activities have quenched about 260 of the natural endowment. Today, more than half of the world’s remaining geysers are located in Yellowstone National Park, northwest Wyoming, USA. However, the hydrothermal reservoirs that supply Yellowstone’s geysers extend well beyond the Park borders, and onto two “Known Geothermal Resource Areas”—Island Park to the west and Corwin Springs on the north. Geysers are sensitive geologic features that are easily quenched by nearby geothermal wells. Therefore, the potential for geothermal energy development adjacent to Yellowstone poses a threat to the sustainability of about 500 geysers and 10,000 hydrothermal features. The purpose here is to propose that Yellowstone be protected by a “Geyser Protection Area” (GPA) extending in a 120-km radius from Old Faithful Geyser. The GPA concept would prohibit geothermal and large-scale groundwater wells, and thereby protect the water and heat supply of the hydrothermal reservoirs that support Yellowstone’s geyser basins and important hot springs. Proactive federal leadership, including buyouts of private groundwater development rights, can assist in navigating the GPA through the greater Yellowstone area’s “wicked” public policy environment. Moreover, the potential impacts on geyser basins from intrusive research sampling techniques are considered in order to facilitate the updating of national park research regulations to a precautionary standard. The GPA model can provide the basis for protecting the world’s few remaining geyser basins.

Physically Based Modeling of Delta Island Consumptive Use: Fabian Tract and Staten Island, California

Directory of Open Access Journals (Sweden)

Lucas J. Siegfried

2014-12-01

Full Text Available doi: http://dx.doi.org/10.15447/sfews.2014v12iss4art2Water use estimation is central to managing most water problems. To better understand water use in California’s Sacramento–San Joaquin Delta, a collaborative, integrated approach was used to predict Delta island diversion, consumption, and return of water on a more detailed temporal and spatial resolution. Fabian Tract and Staten Island were selected for this pilot study based on available data and island accessibility. Historical diversion and return location data, water rights claims, LiDAR digital elevation model data, and Google Earth were used to predict island diversion and return locations, which were tested and improved through ground-truthing. Soil and land-use characteristics as well as weather data were incorporated with the Integrated Water Flow Model Demand Calculator to estimate water use and runoff returns from input agricultural lands. For modeling, the islands were divided into grid cells forming subregions, representing fields, levees, ditches, and roads. The subregions were joined hydrographically to form diversion and return watersheds related to return and diversion locations. Diversions and returns were limited by physical capacities. Differences between initial model and measured results point to the importance of seepage into deeply subsided islands. The capabilities of the models presented far exceeded current knowledge of agricultural practices within the Delta, demonstrating the need for more data collection to enable improvements upon current Delta Island Consumptive Use estimates.

Population Size and Decadal Trends of Three Penguin Species Nesting at Signy Island, South Orkney Islands.

Science.gov (United States)

Dunn, Michael J; Jackson, Jennifer A; Adlard, Stacey; Lynnes, Amanda S; Briggs, Dirk R; Fox, Derren; Waluda, Claire M

2016-01-01

We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual

A roadmap for island biology

DEFF Research Database (Denmark)

Patino, Jairo; Whittaker, Robert J.; Borges, Paulo A.V.

2017-01-01

Aims: The 50th anniversary of the publication of the seminal book, The Theory of Island Biogeography, by Robert H. MacArthur and Edward O. Wilson, is a timely moment to review and identify key research foci that could advance island biology. Here, we take a collaborative horizon-scanning approach...... to identify 50 fundamental questions for the continued development of the field. Location: Worldwide. Methods: We adapted a well-established methodology of horizon scanning to identify priority research questions in island biology, and initiated it during the Island Biology 2016 conference held in the Azores......); global change (5); conservation and management policies (5); and invasive alien species (4). Main conclusions: Collectively, this cross-disciplinary set of topics covering the 50 fundamental questions has the potential to stimulate and guide future research in island biology. By covering fields ranging...

K Basin safety analysis

International Nuclear Information System (INIS)

Porten, D.R.; Crowe, R.D.

1994-01-01

The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall

Melo carboniferous basin

International Nuclear Information System (INIS)

Flossdarf, A.

1988-01-01

This report is about of the Melo carboniferous basin which limits are: in the South the large and high Tupambae hill, in the west the Paraiso hill and the river mountains, in the North Yaguaron river basin to Candidata in Rio Grande del Sur in Brazil.

Sedimentary mechanisms of a modern banded iron formation on Milos Island, Greece

Directory of Open Access Journals (Sweden)

E. Chi Fru

2018-05-01

Full Text Available An early Quaternary shallow submarine hydrothermal iron formation (IF in the Cape Vani sedimentary basin (CVSB on Milos Island, Greece, displays banded rhythmicity similar to Precambrian banded iron formation (BIF. Field-wide stratigraphic and biogeochemical reconstructions show two temporal and spatially isolated iron deposits in the CVSB with distinct sedimentological character. Petrographic screening suggests the presence of a photoferrotrophic-like microfossil-rich IF (MFIF, accumulated on a basement consisting of andesites in a ∼ 150 m wide basin in the SW margin of the basin. A banded nonfossiliferous IF (NFIF sits on top of the Mn-rich sandstones at the transition to the renowned Mn-rich formation, capping the NFIF unit. Geochemical data relate the origin of the NFIF to periodic submarine volcanism and water column oxidation of released Fe(II in conditions predominated by anoxia, similar to the MFIF. Raman spectroscopy pairs hematite-rich grains in the NFIF with relics of a carbonaceous material carrying an average δ13Corg signature of ∼ −25‰. A similar δ13Corg signature in the MFIF could not be directly coupled to hematite by mineralogy. The NFIF, which postdates large-scale Mn deposition in the CVSB, is composed primarily of amorphous Si (opal-SiO2 ⋅ nH2O while crystalline quartz (SiO2 predominates the MFIF. An intricate interaction between tectonic processes, changing redox, biological activity, and abiotic Si precipitation are proposed to have collectively formed the unmetamorphosed BIF-type deposits in a shallow submarine volcanic center. Despite the differences in Precambrian ocean–atmosphere chemistry and the present geologic time, these formation mechanisms coincide with those believed to have formed Algoma-type BIFs proximal to active seafloor volcanic centers.

Evaluating Potential Tipping Points of Antarctic basins

Science.gov (United States)

Durand, G.; Sainan, S.; Pattyn, F.; Jourdain, N.

2017-12-01

Antarctica is currently loosing mass and its forthcoming contribution to sea-level rise could substantially increase during the coming centuries. This is essentially due to geometrical constraints, i.e., in regions where grounded ice lies on a bedrock below sea-level sloping down towards the interior of the ice sheet (retrograde slope). For such a configuration the ice sheet is considered potentially unstable, as suggested by theory. However, recent observations on accelerated grounding-line retreat and new insights in modeling Pine Island and Thwaites glaciers give evidence that such self-sustained retreat, called marine ice sheet instability (MISI), has already been on its way. Although West Antarctica appears to be the most vulnerable region for MISI occurrence, similar topographic configurations are also observed in East Antarctica, in the Wilkes Basin in particular. Therefore, evaluating the MISI potential at a pan-Antarctic scale is becoming a priority. Here, using the f.ETISh ice sheet model, an ensemble of simulations of the entire contemporary Antarctic ice sheet has been carried out. In particular, we investigate the debuttressing of ice shelves required to initiate MISI for each coastal region around Antarctica by forcing the model with realistic sub-shelf melt pulses of varying duration and amplitude. We further identify the currently grounded areas where the outlet glaciers could hardly stabilize, the Amundsen Sea Sector being the more prone to large self-sustained retreats. On the contrary, the ability of Cook and Ninnis ice shelves to recover after large perturbations and enough buttress upstream outlet glaciers tends to limit self-sustained retreat of the sector. For each basin, rates of contribution to sea-level rise are discussed together with the RCPs and time when tipping points could be reached and MISI triggered.

Early migration and estuary stopover of introduced chinook salmon population in the Lapataia River Basin, southern Tierra del Fuego Island

Science.gov (United States)

Chalde, T.; Fernández, D. A.

2017-12-01

Established populations of chinook salmon (Oncorhynchus tshawytscha) have recently been reported in South America, at both Atlantic and Pacific basins. Several studies have evaluated different aspects of their life histories; however, little is known about the use of the estuaries by the juveniles of these populations. We examined spawning time, seaward migration timing, growth rate, scale patterns, diet, and geometric morphometric, contrasting the early life history during freshwater and estuary residence of a chinook population established in Lapataia Basin. Fall run spawning took place in March-April and the parr emerged in September. Two distinct seaward migration patterns were identified from sein net fishing records: one population segment migrating earlier to the estuary in October and a second group migrating later in February. The growth rate of fish captured at the estuary was significantly higher than the fish captured in freshwater. In addition, higher scale intercirculi distances were observed in estuary fish showing differences in growth rate. The feeding habitat in fish captured in both environments changed through time from bottom feeding to surface feeding and from significant diet overlap to no overlap. The morphology of the fish captured at the estuary was associated with the elongation of the caudal peduncle and a decrease in the condition factor index, both changes related to smolt transformation. The earlier migration and the higher growth rate of juveniles in the estuary together with fish of 1 + yo captured in this environment reveal that the estuary of Lapataia Basin is not only a stopover for the chinook salmon, but also a key habitat to reside and feed previous to the final seaward migration.

Pediatrics in the Marshall Islands

International Nuclear Information System (INIS)

Dungy, C.I.; Morgan, B.C.; Adams, W.H.

1984-01-01

The delivery of health care to children living on isolated island communities presents unique challenges to health professionals. An evolved method of providing longitudinal services to infants and children residing on islands of the Marshall Island chain - a central Pacific portion of the Micronesian archipelago - is presented. The difficulties associated with provision of comprehensive health care in a vast ocean area are discussed

Issues and Tensions in Island Heritage Management: A Case Study of Motuihe Island, New Zealand

Directory of Open Access Journals (Sweden)

David Bade

2010-05-01

Full Text Available This paper draws on a New Zealand case study, Motuihe Island, to examine the challenges of conserving cultural heritage in places renowned for natural heritage values. In keeping with the broader trend toward the ecological restoration of islands close to Auckland, Motuihe Island is undergoing conversion into an ecosystem of native flora and fauna. Issues and tensions relating to the management of natural and cultural heritage will be discussed and influencing aspects investigated: the nature/culture dualism, the effect of New Zealand’s history and identity, and the influence of islandness on heritage management.

Status of the Island Night Lizard and Two Non-Native Lizards on Outlying Landing Field San Nicolas Island, California

Science.gov (United States)

Fellers, Gary M.; Drost, Charles A.; Murphey, Thomas G.

2008-01-01

More than 900 individually marked island night lizards (Xantusia riversiana) were captured on San Nicolas Island, California, between 1984 and 2007 as part of an ongoing study to monitor the status of this threatened species. Our data suggest that at least a few lizards are probably more than 20 years old, and one lizard would be 31.5 years old if it grew at an average rate for the population. Ages of 20 and 30 years seem reasonable given the remarkably slow growth during capture intervals of more than a decade for five of the lizards which we estimated to be 20 or more years old. Like other lizards, island night lizard growth rates vary by size, with larger lizards growing more slowly. In general, growth rates were somewhat greater on San Nicolas Island (compared with Santa Barbara Island), and this increase was sustained through all of the intermediate size classes. The higher growth rate may account for the somewhat larger lizards present on San Nicolas Island, although we cannot discount the possibility that night lizards on San Nicolas are merely living longer. The high percentage of small lizards in the Eucalyptus habitat might seem to reflect a healthy population in that habitat, but the high proportion of small lizards appears to be caused by good reproduction in the 1900s and substantially poorer reproduction in subsequent years. The Eucalyptus habitat has dried quite a bit in recent years. Night lizards in the Haplopappus/Grassland habitat have shown an increase in the proportion of larger lizards since 2000. There has also been an increase in the proportion of large lizards in the Rock Cobble habitat at Redeye Beach. However, there are has been some change in habitat with more elephant seals occupying the same area just above the high tide as do the night lizards. Southern alligator lizards and side-blotched lizards are both non-native on San Nicolas Island. Neither lizard causes obvious harm to island night lizards, and management time and effort should

Basin Hopping Graph

DEFF Research Database (Denmark)

Kucharik, Marcel; Hofacker, Ivo; Stadler, Peter

2014-01-01

of the folding free energy landscape, however, can provide the relevant information. Results We introduce the basin hopping graph (BHG) as a novel coarse-grained model of folding landscapes. Each vertex of the BHG is a local minimum, which represents the corresponding basin in the landscape. Its edges connect...

Active intra-basin faulting in the Northern Basin of Lake Malawi from seismic reflection data

Science.gov (United States)

Shillington, D. J.; Chindandali, P. R. N.; Scholz, C. A.; Ebinger, C. J.; Onyango, E. A.; Peterson, K.; Gaherty, J. B.; Nyblade, A.; Accardo, N. J.; McCartney, T.; Oliva, S. J.; Kamihanda, G.; Ferdinand, R.; Salima, J.; Mruma, A. H.

2016-12-01

Many questions remain about the development and evolution of fault systems in weakly extended rifts, including the relative roles of border faults and intra-basin faults, and segmentation at various scales. The northern Lake Malawi (Nyasa) rift in the East African Rift System is an early stage rift exhibiting pronounced tectonic segmentation, which is defined by 100-km-long border faults. The basins also contain a series of intrabasinal faults and associated synrift sediments. The occurrence of the 2009 Karonga Earthquake Sequence on one of these intrabasinal faults indicates that some of them are active. Here we present new multichannel seismic reflection data from the Northern Basin of the Malawi Rift collected in 2015 as a part of the SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) project. This rift basin is bound on its east side by the west-dipping Livingstone border fault. Over 650 km of seismic reflection profiles were acquired in the Northern Basin using a 500 to 1540 cu in air gun array and a 1200- to 1500-m seismic streamer. Dip lines image a series of north-south oriented west-dipping intra-basin faults and basement reflections up to 5 s twtt near the border fault. Cumulative offsets on intra-basin faults decrease to the west. The largest intra-basin fault has a vertical displacement of >2 s two-way travel time, indicating that it has accommodated significant total extension. Some of these intra-basin faults offset the lake bottom and the youngest sediments by up to 50 s twtt ( 37 m), demonstrating they are still active. The two largest intra-basin faults exhibit the largest offsets of young sediments and also correspond to the area of highest seismicity based on analysis of seismic data from the 89-station SEGMeNT onshore/offshore network (see Peterson et al, this session). Fault patterns in MCS profiles vary along the basin, suggesting a smaller scale of segmentation of faults within the basin; these variations in fault patterns

Vulnerability assessment of small islands to tourism: The case of the Marine Tourism Park of the Gili Matra Islands, Indonesia

Directory of Open Access Journals (Sweden)

Fery Kurniawan

2016-04-01

Full Text Available The Indonesian government is currently directing its focus of development on the optimum uses of marine and coastal ecosystem services including the marine and coastal tourism. One of the main locus of coastal and marine tourism is the small islands tourism such as Gili Matra Islands among others. Small islands tourism is one of the favourite touristic activities because the destination provides beauty, exotism, aesthetic and a diversity of natural habitats including the warm, clear and attractive water. Tourism is being considered as a development instrument in order to boost a country’s economy and has become part of the global industry. However, tourism is also one of the actors that is responsible for environmental depletion, due to the constructions of buildings and tourism activities. This paper aims to study the level of vulnerability in small islands to tourism as a basis of integrated small islands management in Indonesian conservation area. The group of islands in this study consists of three islands namely Gili Ayer Island, Gili Meno Island and Gili Trawangan Island (known as Gili Matra Islands that were observed using Small Islands Vulnerability Index (SIVI. The results indicate that Gili Matra Islands have a vulnerability status from low into moderate, ranging from 2.25 to 2.75. Gili Ayer Island has the highest vulnerability with SIVI of 2.75 (Moderate, followed by Gili Meno Island with SIVI of 2.50 (Low and Gili Trawangan Island with SIVI of 2.25 (Low. The driving factor of vulnerability is the intensive utilization of marine tourism activities. Tourism is the sole stress to Gili Matra Island’s ecosystem due to its direct damaging impact and reducing its environmental quality. The vulnerability index which was built from the coastline, coral reef, live coral reef, and development area was applicable to assess the small island’s vulnerability in Indonesia, especially for coral island.

Dendrochronology of Strain-Relaxed Islands

International Nuclear Information System (INIS)

Merdzhanova, T.; Kiravittaya, S.; Rastelli, A.; Stoffel, M.; Denker, U.; Schmidt, O.G.

2006-01-01

We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes

Dendrochronology of strain-relaxed islands.

Science.gov (United States)

Merdzhanova, T; Kiravittaya, S; Rastelli, A; Stoffel, M; Denker, U; Schmidt, O G

2006-06-09

We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes.

River basin administration

Science.gov (United States)

Management of international rivers and their basins is the focus of the Centre for Comparative Studies on (International) River Basin Administration, recently established at Delft University of Technology in the Netherlands. Water pollution, sludge, and conflicting interests in the use of water in upstream and downstream parts of a river basin will be addressed by studying groundwater and consumption of water in the whole catchment area of a river.Important aspects of river management are administrative and policy aspects. The Centre will focus on policy, law, planning, and organization, including transboundary cooperation, posing standards, integrated environmental planning on regional scale and environmental impact assessments.

The Limacidae of the Canary Islands

NARCIS (Netherlands)

Regteren Altena, van C.O.

1950-01-01

CONTENTS Introduction............... 3 Systematic survey of the Limacidae of the central and western Canary Islands 5 Biogeographical notes on the Limacidae of the Canary Islands . . . . 21 Alphabetical list of the persons who collected or observed Limacidae in the Canary Islands.............. 31

Sediment-hosted micro-disseminated gold mineralization constrained by basin paleo-topographic highs in the Youjiang basin, South China

Science.gov (United States)

Liu, Jianming; Ye, Jie; Ying, Hanlong; Liu, Jiajun; Zheng, Minghua; Gu, Xuexiang

2002-06-01

The Youjiang basin is a Devonian-Triassic rift basin on the southern margin of the Yangtze Craton in South China. Strong syndepositional faulting defined the basin-and-range style paleo-topography that further developed into isolated carbonate platforms surrounded by siliciclastic filled depressions. Finally, thick Triassic siliciclastic deposits covered the platforms completely. In the Youjiang basin, numerous sediment-hosted, micro-disseminated gold (SMG) deposits occur mainly in Permian-Triassic chert and siliciclastic rocks. SMG ores are often auriferous sedimentary rocks with relatively low sulfide contents and moderate to weak alteration. Similar to Carlin-type gold ores in North America, SMG ores in the Youjiang basin are characterized by low-temperature mineral assemblages of pyrite, arsenopyrite, realgar, stibnite, cinnabar, marcasite, chalcedony and carbonate. Most of the SMG deposits are remarkably distributed around the carbonate platforms. Accordingly, there are platform-proximal and platform-distal SMG deposits. Platform-proximal SMG deposits often occur in the facies transition zone between the underlying platform carbonate rocks and the overlying siliciclastic rocks with an unconformity (often a paleo-karst surface) in between. In the ores and hostrocks there are abundant synsedimentary-syndiagenetic fabrics such as lamination, convolute bedding, slump texture, soft-sediment deformation etc. indicating submarine hydrothermal deposition and syndepositional faulting. Numerous fluid-escape and liquefaction fabrics imply strong fluid migration during sediment basin evolution. Such large-scale geological and fabric evidence implies that SMG ores were formed during basin evolution, probably in connection with basinal fluids. It is well known that basinal fluids (especially sediment-sourced fluids) will migrate generally (1) upwards, (2) towards basin margins or basin topographic highs, (3) and from thicker towards thinner deposits during basin evolution

Genomic island excisions in Bordetella petrii

Directory of Open Access Journals (Sweden)

Levillain Erwan

2009-07-01

Full Text Available Abstract Background Among the members of the genus Bordetella B. petrii is unique, since it is the only species isolated from the environment, while the pathogenic Bordetellae are obligately associated with host organisms. Another feature distinguishing B. petrii from the other sequenced Bordetellae is the presence of a large number of mobile genetic elements including several large genomic regions with typical characteristics of genomic islands collectively known as integrative and conjugative elements (ICEs. These elements mainly encode accessory metabolic factors enabling this bacterium to grow on a large repertoire of aromatic compounds. Results During in vitro culture of Bordetella petrii colony variants appear frequently. We show that this variability can be attributed to the presence of a large number of metastable mobile genetic elements on its chromosome. In fact, the genome sequence of B. petrii revealed the presence of at least seven large genomic islands mostly encoding accessory metabolic functions involved in the degradation of aromatic compounds and detoxification of heavy metals. Four of these islands (termed GI1 to GI3 and GI6 are highly related to ICEclc of Pseudomonas knackmussii sp. strain B13. Here we present first data about the molecular characterization of these islands. We defined the exact borders of each island and we show that during standard culture of the bacteria these islands get excised from the chromosome. For all but one of these islands (GI5 we could detect circular intermediates. For the clc-like elements GI1 to GI3 of B. petrii we provide evidence that tandem insertion of these islands which all encode highly related integrases and attachment sites may also lead to incorporation of genomic DNA which originally was not part of the island and to the formation of huge composite islands. By integration of a tetracycline resistance cassette into GI3 we found this island to be rather unstable and to be lost from

CRED Gridded Bathymetry of Necker Island (100-021) in the Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-021b is a 60-m ASCII grid of depth data collected near Necker Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as...

Mapping Monthly Water Scarcity in Global Transboundary Basins at Country-Basin Mesh Based Spatial Resolution.

Science.gov (United States)

Degefu, Dagmawi Mulugeta; Weijun, He; Zaiyi, Liao; Liang, Yuan; Zhengwei, Huang; Min, An

2018-02-01

Currently fresh water scarcity is an issue with huge socio-economic and environmental impacts. Transboundary river and lake basins are among the sources of fresh water facing this challenge. Previous studies measured blue water scarcity at different spatial and temporal resolutions. But there is no global water availability and footprint assessment done at country-basin mesh based spatial and monthly temporal resolutions. In this study we assessed water scarcity at these spatial and temporal resolutions. Our results showed that around 1.6 billion people living within the 328 country-basin units out of the 560 we assessed in this study endures severe water scarcity at least for a month within the year. In addition, 175 country-basin units goes through severe water scarcity for 3-12 months in the year. These sub-basins include nearly a billion people. Generally, the results of this study provide insights regarding the number of people and country-basin units experiencing low, moderate, significant and severe water scarcity at a monthly temporal resolution. These insights might help these basins' sharing countries to design and implement sustainable water management and sharing schemes.

Great Basin Experimental Range: Annotated bibliography

Science.gov (United States)

E. Durant McArthur; Bryce A. Richardson; Stanley G. Kitchen

2013-01-01

This annotated bibliography documents the research that has been conducted on the Great Basin Experimental Range (GBER, also known as the Utah Experiment Station, Great Basin Station, the Great Basin Branch Experiment Station, Great Basin Experimental Center, and other similar name variants) over the 102 years of its existence. Entries were drawn from the original...

The geology of the Falkland Islands

OpenAIRE

Aldiss, D.T.; Edwards, E.J.

1999-01-01

This report is complementary to the 1:250 000 scale geological map of the Falkland Islands compiled in 1998. The report and map are products of the Falkland Islands Geological Mapping Project (1996-1998). Geological observation and research in the Islands date from 1764. The Islands were visited during two pioneering scientific cruises in the 19th century. Subsequently, many scientists visited en route to the Antarctic or Patagonia. Geological affinities to other parts of the sout...

Nomination of the Globigerina Limestone of the Maltese Islands as a "Global Heritage Stone Resource"

Science.gov (United States)

Cassar, JoAnn

2016-04-01

The Maltese Islands consist of two main islands, Malta and Gozo, as well as a small number of islets, and lie in the central Mediterranean Sea approximately 90 km south of Sicily. Although only 316 square kilometres in size, the Islands contain a rich concentration of archaeological sites and historic buildings, as well as vernacular architecture and modern buildings, for the most part built of the local Globigerina Limestone, which is one of the few natural resources of the Islands. This stone can be described as a typical "soft limestone", very easy to carve and shape. It forms part of the large family of Oligo-Miocene "soft limestones" widely diffused in the Mediterranean Basin. The Maltese Globigerina Limestone Formation is one of five main Formations, and varies in thickness from 20 to over 200 m. The material used for building is located stratigraphically in the lower part of the Globigerina Limestone Formation, called the Lower Globigerina Limestone. This Formation is stratified into thick beds at outcrop. Sections where bioturbation is concentrated often also occur. This limestone is fine-grained, yellow to pale grey in colour, almost wholly composed of the tests of globigerinid planktonic foraminifera. Petrographically, Globigerina Limestone can be described as a bioclastic packstone, with bioclastic wackestones also occurring. This limestone has always been used as the predominant building material in the Islands. The Maltese prehistoric Temples, which were constructed approximately 6000 years ago, bear testimony to this. Between 1530 and 1798 the Order of the Knights of St John built kilometres of fortifications in this same material to protect the Island from the expanding Ottoman Empire. Fortifications, impressive churches, auberges and palaces were built of this stone during this period. The capital city of Valletta, a rich and dense manifestation of Baroque architecture in Globigerina Limestone, is included on the UNESCO World Heritage List, as are

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

Science.gov (United States)

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

2013-12-01

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

Frequency and sources of basin floor turbidites in alfonso basin, Gulf of California, Mexico: Products of slope failures

Science.gov (United States)

Gonzalez-Yajimovich, Oscar E.; Gorsline, Donn S.; Douglas, Robert G.

2007-07-01

Alfonso Basin is a small margin basin formed by extensional tectonics in the actively rifting, seismically active Gulf of California. The basin is centered at 24°40' N and 110° 38' W, and is a closed depression (maximum depth 420 m) with an effective sill depth of about 320 m (deepest sill), a width of 20 km and length of 25 km. Basin floor area below a depth of 350 m is about 260 km 2. The climate is arid to semiarid but was wetter during the early (ca. 10,000-7000 Calendar years Before Present [BP]) and middle Holocene (ca. 7000-4000 Cal. Years BP). Basin-wide turbidity currents reach the floor of Alfonso Basin at centennial to millennial intervals. The peninsular drainages tributary to the basin are small and have maximum flood discharges of the order of 10 4m 3. The basin-floor turbidites thicker than 1 cm have volumes of the order of 10 6m 3 to 10 8m 3 and require a much larger source. The largest turbidite seen in our cores is ca. 1 m thick in the central basin floor and was deposited 4900 Calendar Years Before Present (BP). Two smaller major events occurred about 1500 and 2800 Cal. Years BP. Seismicity over the past century of record shows a clustering of larger epicenters along faults forming the eastern Gulf side of Alfonso Basin. In that period there have been four earthquakes with magnitudes above 7.0 but all are distant from the basin. Frequency of such earthquakes in the basin vicinity is probably millennial. It is concluded that the basin-wide turbidites thicker than 1 cm must be generated by slope failures on the eastern side of the basin at roughly millennial intervals. The thin flood turbidites have a peninsular source at centennial frequencies.

Forces in the development of remote islands in Japan : A case study of local energy enterprises in Tsushima Island

OpenAIRE

Matsumura, Yuko; Miyoshi, Emako

2018-01-01

Japan, one of the most famous islander nations in the world, has promoted the development of its remote islands for over 60 years after the Second World War. The target islands and projects for fostering development have been steadily expanded. However, the country is facing serious socio-economic challenges such as aging and recession, resulting in less available funding for preferential treatment to remote islands. Thus, the framework for boosting island development should be reconsidered, ...

Population Size and Decadal Trends of Three Penguin Species Nesting at Signy Island, South Orkney Islands.

Directory of Open Access Journals (Sweden)

Michael J Dunn

Full Text Available We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae, chinstrap (Pygoscelis antarctica and gentoo (Pygoscelis papua ellsworthii over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum, chinstrap penguins declined by 68% (-3.6% per annum and Adélie penguins declined by 42% (-1.5% per annum. The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a

CpG island mapping by epigenome prediction.

Directory of Open Access Journals (Sweden)

Christoph Bock

2007-06-01

Full Text Available CpG islands were originally identified by epigenetic and functional properties, namely, absence of DNA methylation and frequent promoter association. However, this concept was quickly replaced by simple DNA sequence criteria, which allowed for genome-wide annotation of CpG islands in the absence of large-scale epigenetic datasets. Although widely used, the current CpG island criteria incur significant disadvantages: (1 reliance on arbitrary threshold parameters that bear little biological justification, (2 failure to account for widespread heterogeneity among CpG islands, and (3 apparent lack of specificity when applied to the human genome. This study is driven by the idea that a quantitative score of "CpG island strength" that incorporates epigenetic and functional aspects can help resolve these issues. We construct an epigenome prediction pipeline that links the DNA sequence of CpG islands to their epigenetic states, including DNA methylation, histone modifications, and chromatin accessibility. By training support vector machines on epigenetic data for CpG islands on human Chromosomes 21 and 22, we identify informative DNA attributes that correlate with open versus compact chromatin structures. These DNA attributes are used to predict the epigenetic states of all CpG islands genome-wide. Combining predictions for multiple epigenetic features, we estimate the inherent CpG island strength for each CpG island in the human genome, i.e., its inherent tendency to exhibit an open and transcriptionally competent chromatin structure. We extensively validate our results on independent datasets, showing that the CpG island strength predictions are applicable and informative across different tissues and cell types, and we derive improved maps of predicted "bona fide" CpG islands. The mapping of CpG islands by epigenome prediction is conceptually superior to identifying CpG islands by widely used sequence criteria since it links CpG island detection to

CpG island mapping by epigenome prediction.

Science.gov (United States)

Bock, Christoph; Walter, Jörn; Paulsen, Martina; Lengauer, Thomas

2007-06-01

CpG islands were originally identified by epigenetic and functional properties, namely, absence of DNA methylation and frequent promoter association. However, this concept was quickly replaced by simple DNA sequence criteria, which allowed for genome-wide annotation of CpG islands in the absence of large-scale epigenetic datasets. Although widely used, the current CpG island criteria incur significant disadvantages: (1) reliance on arbitrary threshold parameters that bear little biological justification, (2) failure to account for widespread heterogeneity among CpG islands, and (3) apparent lack of specificity when applied to the human genome. This study is driven by the idea that a quantitative score of "CpG island strength" that incorporates epigenetic and functional aspects can help resolve these issues. We construct an epigenome prediction pipeline that links the DNA sequence of CpG islands to their epigenetic states, including DNA methylation, histone modifications, and chromatin accessibility. By training support vector machines on epigenetic data for CpG islands on human Chromosomes 21 and 22, we identify informative DNA attributes that correlate with open versus compact chromatin structures. These DNA attributes are used to predict the epigenetic states of all CpG islands genome-wide. Combining predictions for multiple epigenetic features, we estimate the inherent CpG island strength for each CpG island in the human genome, i.e., its inherent tendency to exhibit an open and transcriptionally competent chromatin structure. We extensively validate our results on independent datasets, showing that the CpG island strength predictions are applicable and informative across different tissues and cell types, and we derive improved maps of predicted "bona fide" CpG islands. The mapping of CpG islands by epigenome prediction is conceptually superior to identifying CpG islands by widely used sequence criteria since it links CpG island detection to their characteristic

CRED Gridded Bathymetry of Nihoa Island (100-025) in the Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-025b is a 60-m ASCII grid of depth data collected near Nihoa Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as part...

Equilibrium theory of island biogeography: A review

Science.gov (United States)

Angela D. Yu; Simon A. Lei

2001-01-01

The topography, climatic pattern, location, and origin of islands generate unique patterns of species distribution. The equilibrium theory of island biogeography creates a general framework in which the study of taxon distribution and broad island trends may be conducted. Critical components of the equilibrium theory include the species-area relationship, island-...

Cost-effective reduction of eutrophication in the Gulf of Kalloni (Island of Lesvos, Greece

Directory of Open Access Journals (Sweden)

B. ZANOU

2001-06-01

Full Text Available This study presents a cost-effective analysis by comparing the costs of measures (options to improve the quality of bathing waters in the Gulf of Kalloni (island of Lesvos, Greece in order to reduce the anthropogenic eutrophication in the coastal water of the Kalloni Gulf. The Gulf of Kalloni is a semi-enclosed gulf (115 km2 which receives municipal wastewater, agricultural activity drainage, and at times sewage from olive oil plants processing the local olives harvest. The area of study consists of the coastal waters and the river basin of which water run-off drains into the gulf. Four options are comparable in their environmental effectiveness to reduce eurtophication damages which are: municipal wastewater treatment plant, construction of dams, organic farming plus training and olive oil wastewater treatment plant.

Nearshore coastal bathymetry data collected in 2016 from West Ship Island to Horn Island, Gulf Islands National Seashore, Mississippi

Science.gov (United States)

DeWitt, Nancy T.; Stalk, Chelsea A.; Fredericks, Jake J.; Flocks, James G.; Kelso, Kyle W.; Farmer, Andrew S.; Tuten, Thomas M.; Buster, Noreen A.

2018-04-13

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center, in cooperation with the U.S. Army Corps of Engineers, Mobile District, conducted bathymetric surveys of the nearshore waters surrounding Ship and Horn Islands, Gulf Islands National Seashore, Mississippi. The objective of this study was to establish base-level elevation conditions around West Ship, East Ship, and Horn Islands and their associated active littoral system prior to restoration activities. These activities include the closure of Camille Cut and the placement of sediment in the littoral zone of East Ship Island. These surveys can be compared with future surveys to monitor sediment migration patterns post-restoration and can also be measured against historic bathymetric datasets to further our understanding of island evolution.The USGS collected 667 line-kilometers (km) of single-beam bathymetry data and 844 line-km of interferometric swath bathymetry data in July 2016 under Field Activity Number 2016-347-FA. Data are provided in three datums: (1) the International Terrestrial Reference Frame of 2000 (ellipsoid height); (2) the North American Datum of 1983 (NAD83) CORS96 realization and the North American Vertical Datum of 1988 with respect to the GEOID12B model (orthometric height); and (3) NAD83 (CORS96) and Mean Lower Low Water (tidal datum). Data products, including x,y,zpoint datasets, trackline shapefiles, digital and handwritten Field Activity Collection Systems logs, 50-meter digital elevation model, and formal Federal Geographic Data Committee metadata, are available for download.

Constraining Basin Depth and Fault Displacement in the Malombe Basin Using Potential Field Methods

Science.gov (United States)

Beresh, S. C. M.; Elifritz, E. A.; Méndez, K.; Johnson, S.; Mynatt, W. G.; Mayle, M.; Atekwana, E. A.; Laó-Dávila, D. A.; Chindandali, P. R. N.; Chisenga, C.; Gondwe, S.; Mkumbwa, M.; Kalaguluka, D.; Kalindekafe, L.; Salima, J.

2017-12-01

The Malombe Basin is part of the Malawi Rift which forms the southern part of the Western Branch of the East African Rift System. At its southern end, the Malawi Rift bifurcates into the Bilila-Mtakataka and Chirobwe-Ntcheu fault systems and the Lake Malombe Rift Basin around the Shire Horst, a competent block under the Nankumba Peninsula. The Malombe Basin is approximately 70km from north to south and 35km at its widest point from east to west, bounded by reversing-polarity border faults. We aim to constrain the depth of the basin to better understand displacement of each border fault. Our work utilizes two east-west gravity profiles across the basin coupled with Source Parameter Imaging (SPI) derived from a high-resolution aeromagnetic survey. The first gravity profile was done across the northern portion of the basin and the second across the southern portion. Gravity and magnetic data will be used to constrain basement depths and the thickness of the sedimentary cover. Additionally, Shuttle Radar Topography Mission (SRTM) data is used to understand the topographic expression of the fault scarps. Estimates for minimum displacement of the border faults on either side of the basin were made by adding the elevation of the scarps to the deepest SPI basement estimates at the basin borders. Our preliminary results using SPI and SRTM data show a minimum displacement of approximately 1.3km for the western border fault; the minimum displacement for the eastern border fault is 740m. However, SPI merely shows the depth to the first significantly magnetic layer in the subsurface, which may or may not be the actual basement layer. Gravimetric readings are based on subsurface density and thus circumvent issues arising from magnetic layers located above the basement; therefore expected results for our work will be to constrain more accurate basin depth by integrating the gravity profiles. Through more accurate basement depth estimates we also gain more accurate displacement

Three-dimensional modeling of pull-apart basins: implications for the tectonics of the Dead Sea Basin

Science.gov (United States)

Katzman, Rafael; ten Brink, Uri S.; Lin, Jian

1995-01-01

We model the three-dimensional (3-D) crustal deformation in a deep pull-apart basin as a result of relative plate motion along a transform system and compare the results to the tectonics of the Dead Sea Basin. The brittle upper crust is modeled by a boundary element technique as an elastic block, broken by two en echelon semi-infinite vertical faults. The deformation is caused by a horizontal displacement that is imposed everywhere at the bottom of the block except in a stress-free “shear zone” in the vicinity of the fault zone. The bottom displacement represents the regional relative plate motion. Results show that the basin deformation depends critically on the width of the shear zone and on the amount of overlap between basin-bounding faults. As the width of the shear zone increases, the depth of the basin decreases, the rotation around a vertical axis near the fault tips decreases, and the basin shape (the distribution of subsidence normalized by the maximum subsidence) becomes broader. In contrast, two-dimensional plane stress modeling predicts a basin shape that is independent of the width of the shear zone. Our models also predict full-graben profiles within the overlapped region between bounding faults and half-graben shapes elsewhere. Increasing overlap also decreases uplift near the fault tips and rotation of blocks within the basin. We suggest that the observed structure of the Dead Sea Basin can be described by a 3-D model having a large overlap (more than 30 km) that probably increased as the basin evolved as a result of a stable shear motion that was distributed laterally over 20 to 40 km.

Checklist of marine fishes of the Zunan Islands, located between the Izu and Ogasawara (Bonin) islands, Japan, with zoogeographical comments

OpenAIRE

Kuriiwa, Kaoru; Arihara, Hisashi; Chiba, Satoru; Kato, Shoichi; Senou, Hiroshi; Matsuura, Keiichi

2014-01-01

The Zunan Islands are located 360–650 km south of Tokyo, and consist of four uninhabited volcanoes: the Bayonnaise Rocks, the Smith Rocks, Torishima Island and the Sofugan Rock. Although all of the elements of the Zunan Islands are tiny islets and rocks, they form a series of stepping stones for shallow water fishes between the Izu Islands in the north and the Ogasawara (Bonin) Islands in the south. We report here the first comprehensive survey of marine fishes in the Zunan Islands. A total o...

Ecology and Evolution: Islands of Change.

Science.gov (United States)

Benz, Richard

This book was designed for middle and junior high school science classes and focuses on island biogeography, ecology, and evolution. Sections include: (1) "Galapagos: Frame of Reference"; (2) "Ecology and Islands"; and (3) "Evolution." Nineteen standards-based activities use the Galapagos Islands as a running theme…

Tools for sustainability assessment in island socio-ecological systems: an application to the Canary Islands

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Isabel Banos-González

2016-05-01

Full Text Available An integral dynamic model, in combination with other methods (indicators, policy and scenario analysis, is presented as a tool for sustainability assessment in island socio-ecological systems (SES. The Fuerteventura sustainability model (FSM, tested for the 1996-2011, allows a better understanding of the dynamic interactions between sustainability indicators and other factors of this island. The FSM was first applied to analyse the vulnerability of this island to climate change for the 2012-2025 period; results point to the need for urgent measures to mitigate its effects on some of the analysed indicators. A set of policy measures was then assessed from the behaviour of nine indicators and their sustainability thresholds. Finally, the FSM facilitated the development of a dynamic model of the island of El Hierro, extrapolating the features common to both SES. We propose this to be a useful tool for the quantitative sustainability assessment and the management of real island socio-ecological systems

The Idea of the Archipelago: Contemplating Island Relations

Directory of Open Access Journals (Sweden)

Elaine Stratford

2013-05-01

Full Text Available Creative, innovative, and timely research on islands and island futures is warranted and pressing, not least because island(ers are poorly served by established tropes of them as subordinate to continents or mainlands. Opportunities exist to provide a more thoroughgoing account of island life and island relations, and the seven papers in this special issue address that task. In works that consider islands in the Timor Sea, the Caribbean, the Pacific, Atlantic and Southern Oceans, and that span several different disciplinary frames—archival-historical, critical theoretical, literary, cultural, geopolitical, sociological and artistic—these papers evidence both the diversity of approach to thinking with the archipelago, and numerous points in common. Among the latter is an understanding that island relations are built on connection, assemblage, mobility, and multiplicity, and a commitment to critically examine the ways in which these entanglements affect and give effect to island life. The models of island relationality brought to light by this collective focus on the archipelago reveal new and diverse connections of island peoples with their physical and cultural environments, and with the world beyond; create spaces for growing resilience, association and engagement; and invite further study.

Quantification and Postglacial evolution of an inner alpine sedimentary basin (Gradenmoos Basin, Hohe Tauern)

International Nuclear Information System (INIS)

Götz, J.

2012-01-01

The overall objective of this thesis is the quantification of sediment storage and the reconstruction of postglacial landscape evolution within the glacially overdeepened Gradenmoos Basin (subcatchment size: 4.1 km 2 ; basin floor elevation: 1920 m) in the central Gradenbach catchment (Schober Range, Hohe Tauern, Austrian Alps). Following the approach of denudation-accumulation-systems, most reliable results are obtained (1) if sediment output of a system can be neglected for an established period of time, (2) if sediment storage can be assessed with a high level of accuracy, (3) if the onset of sedimentation and amounts of initially stored sediments are known, and (4) if sediment contributing areas can be clearly delimited. Due to spatial scale and topographic characteristics, all mentioned aspects are fulfilled to a high degree within the studied basin. Applied methods include surface, subsurface and temporal investigations. Digital elevation data is derived from terrestrial laserscanning and geomorphologic mapping. The quantification of sediment storage is based on core drillings, geophysical methods (DC resistivity, refraction seismic, and ground penetrating radar), as well as GIS and 3D modelling. Radiocarbon dating and palynological analyses are additionally used to reconstruct the postglacial infilling progress of the basin. The study reveals that a continuous postglacial stratigraphic record is archived in the basin. As proposed by Lieb (1987) timing of basin deglaciation could be verified to late-Egesen times by means of radiocarbon ages (oldest sample just above basal till: 10.4 ka cal. BP) and first palynologic results. Lateglacial oscillations seem to have effectively scoured the basin, leaving only a shallow layer of basal till. The analysis of postglacial sedimentation in the basin is further improved by the existence of a former lake in the basin lasting for up to 7500 years until approx. 3.7 ka cal. BP. Both, the stratigraphic (fine, partly

Stratigraphy of the Caloris Basin, Mercury: Implications for Volcanic History and Basin Impact Melt

Science.gov (United States)

Ernst, Carolyn M.; Denevi, Brett W.; Barnouin, Olivier S.; Klimczak, Christian; Chabot, Nancy L.; Head, James W.; Murchie, Scott L.; Neumann, Gregory A.; Prockter, Louis M.; Robinson, Mark S.;

seal Arctocephaius tropicaiis at Gough Island

African Journals Online (AJOL)

Population increase in the Amsterdam Island fur seal Arctocephaius tropicaiis at Gough Island. M.N. Bester. Mammal Research Institute, University of Pretoria, Pretoria. Population size of Arctocephalus tropicalis on Gough Island was determined by direct censuses of parts of the coast duro ing the summers of 1974 - 1976 ...

Simple method for calculating island widths

International Nuclear Information System (INIS)

Cary, J.R.; Hanson, J.D.; Carreras, B.A.; Lynch, V.E.

1989-01-01

A simple method for calculating magnetic island widths has been developed. This method uses only information obtained from integrating along the closed field line at the island center. Thus, this method is computationally less intensive than the usual method of producing surfaces of section of sufficient detail to locate and resolve the island separatrix. This method has been implemented numerically and used to analyze the buss work islands of ATF. In this case the method proves to be accurate to at least within 30%. 7 refs

Recommendations for a barrier island breach management plan for Fire Island National Seashore, including the Otis Pike High Dune Wilderness Area, Long Island, New York

Science.gov (United States)

Williams, S. Jeffress; Foley, Mary K.

2007-01-01

The U.S Army Corps of Engineers, New York District is developing engineering plans, including economic costs and benefits, for storm damage reduction along an 83 mile stretch of the coastal barrier islands and beaches on the south shore of Long Island, NY from Fire Island Inlet east to the Montauk Point headland. The plan, expected to include various alternatives for storm protection and erosion mitigation, is referred to as the Fire Island to Montauk Point Reformulation Plan (FIMP). These plans are expected to follow the Corps of Engineers’ Environmental Operating Principles striving for long term environmental sustainability and balance between environmental protection and protection of human health and property. Fire Island National Seashore (FIIS), a 19,579 acre unit of the National Park System includes a 32 mile long coastal barrier island located within the FIMP project area. A seven-mile section of the park, Otis Pike Fire Island High Dune Wilderness Area, is also a designated Federal Wilderness Area. The FIIS includes not only the barrier island and sand dunes, but also several islands, sand flats and wetlands landward of the barrier, submerged parts of Great South Bay shoreface, extending approximately 4,000 feet into the bay with the inner shelf region extending approximately 1,000 feet seaward of the Fire Island shoreline. The Fire Island barrier islands, a sand-starved system dominated by highly dynamic processes, are struggling to maintain their integrity in the face of sea-level rise and storms. Adding to the dilemma is that development on the barriers and the mainland has increased greatly during the past 50 years. As such, managers and decision makers in federal agencies, state agencies and local governments are challenged to balance tradeoffs between protection of lives and property, public access and long term conservation of natural habitats and processes and the plants and animals that depend on these habitats. National Park Service (NPS

Tectonic setting of Cretaceous basins on the NE Tibetan Plateau: Insights from the Jungong basin

Science.gov (United States)

Craddock, W.H.; Kirby, E.; Dewen, Z.; Jianhui, L.

2012-01-01

Quantifying the Cenozoic growth of high topography in the Indo-Asian collision zone remains challenging, due in part to significant shortening that occurred within Eurasia before collision. A growing body of evidence suggests that regions far removed from the suture zone experienced deformation before and during the early phases of Himalayan orogenesis. In the present-day north-eastern Tibetan Plateau, widespread deposits of Cretaceous sediment attest to significant basin formation; however, the tectonic setting of these basins remains enigmatic. We present a study of a regionally extensive network of sedimentary basins that are spatially associated with a system of SE-vergent thrust faults and are now exposed in the high ranges of the north-eastern corner of the Tibetan Plateau. We focus on a particularly well-exposed basin, located ~20km north of the Kunlun fault in the Anyemaqen Shan. The basin is filled by ~900m of alluvial sediments that become finer-grained away from the basin-bounding fault. Additionally, beds in the proximal footwall of the basin-bounding fault exhibit progressive, up-section shallowing and several intraformational unconformities which can be traced into correlative conformities in the distal part of the basin. The observations show sediment accumulated in the basin during fault motion. Regional constraints on the timing of sediment deposition are provided by both fossil assemblages from the Early Cretaceous, and by K-Ar dating of volcanic rocks that floor and cross-cut sedimentary fill. We argue that during the Cretaceous, the interior NE Tibetan Plateau experienced NW-SE contractional deformation similar to that documented throughout the Qinling-Dabie orogen to the east. The Songpan-Ganzi terrane apparently marked the southern limit of this deformation, such that it may have been a relatively rigid block in the Tibetan lithosphere, separating regions experiencing deformation north of the convergent Tethyan margin from regions deforming

Mosquito Surveys Carried out On Green Island, Orchid Island, and Penghu Island, Taiwan, in 2003

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Hwa-Jen Teng

2005-02-01

Full Text Available Field surveys of mosquitoes were carried out on Green, Orchid, and Penghu Islands in 2003 to ascertain the status of mosquito vectors. Eighteen species of mosquitoes were collected, including three species of Anopheles, four species of Aedes, eight species of Culex, two species of Armigeres, and one species of Malaya. Seventeen previously recorded species were not collected in this study but 11 species collected had not previously been recorded. Ten newly recorded species, An. maculatus, An. takasagoensis, Ae. alcasidi, Ae. lineatopennis, Ae. vexans vexans, Ar. omissus, Cx. vishnui, Cx. halifaxii, Cx. hayashii, and Cx. neomimulus, were collected on Green Island and one previously unrecorded species, Ar. subalbatus, was collected on Orchid Island. Potential vectors An. maculatus and An. sinensis, malaria vectors in Korea and Mainland China, Ae. albopictus, a vector of dengue in Taiwan and West Nile virus in the USA, Cx. vishnui and Cx. tritaeniorhynchus, Japanese encephalitis vectors in Taiwan, Ae. vexans vexans, an eastern equine encephalitis vector in the USA, and Cx. quinquefasciatus, a vector of filariasis in Taiwan and West Nile virus in the USA, were among the mosquito species collected.

Source of marine turbidites on the Andaman-Nicobar Islands: Nicobar Fan, Bengal Fan or paleo-Irrawaddy?

Science.gov (United States)

Carter, A.

2017-12-01

Marine turbidites from an axially fed submarine fan are intermittently exposed across the entire chain of the Andaman-Nicobar Islands. Known as the Andaman Flysch (AF) and loosely assigned to the Paleogene, it has been proposed that these rocks are sourced from the Himalaya and thus provide a unique window into early stages of orogenesis. Where the turbidites came from has been subject to debate; they are either Bengal Fan or forearc deposits cut off from the Bengal Fan and possibly sourced from the Irrawaddy delta. Following recent IODP drilling in the eastern Indian Ocean (Expeditions 354 and 362) it is now possible resolve this by comparing the provenance of AF turbidites with the Bengal and Nicobar Fans. The Andaman Flysch can be traced as detached outcrops all along the western side of the main islands of Andaman over a strike length of more than 200 km. Exposures along the east coast are confined to South Andaman Island. Petrographic and geochemical data show a common continental crust signal with minor contributions from arc material. But, there are also differences whereby west coast sandstones show significantly higher quartz content and less feldspars and rock fragments. Staurolite is also present in all samples from the western side, but is absent from east coast samples. Both detrital zircon U-Pb and Bulk rock Nd data record the presence of arc material likely from Myanmar. Detrital zircon data from the Nicobar Fan match the Andaman turbidites and indicate sources from the Greater and Tethyan Himalaya mixed with sediment from the Burmese arc. Transfer of Irrawaddy derived sediment to the Nicobar Fan is ruled out as sediment transfer across the fore-arc to the west was restricted by the then exposed Yadana and M8 highs in the north and the Sewell and Alcock Rises to the south. Sediment isopachs of the Martaban back arc basin, the main north-south-oriented depocentre in the Andaman Sea related to the development of the Thanlwin -Irrawaddy delta system

Intersectional gene flow between insular endemics of Ilex (Aquifoliaceae) on the Bonin Islands and the Ryukyu Islands.

Science.gov (United States)

Setoguchi, H; Watanabe, I

2000-06-01

Hybridization and introgression play important roles in plant evolution, and their occurrence on the oceanic islands provides good examples of plant speciation and diversification. Restriction fragment length polymorphisms (RFLPs) and trnL (UAA) 3'exon-trnF (GAA) intergenic spacer (IGS) sequences of chloroplast DNA (cpDNA), and the sequences of internal transcribed spacer (ITS) of nuclear ribosomal DNA were examined to investigate the occurrence of gene transfer in Ilex species on the Bonin Islands and the Ryukyu Islands in Japan. A gene phylogeny for the plastid genome is in agreement with the morphologically based taxonomy, whereas the nuclear genome phylogeny clusters putatively unrelated endemics both on the Bonin and the Ryukyu Islands. Intersectional hybridization and nuclear gene flow were independently observed in insular endemics of Ilex on both sets of islands without evidence of plastid introgression. Gene flow observed in these island systems can be explained by ecological features of insular endemics, i.e., limits of distribution range or sympatric distribution in a small land area.

Seed islands driven by turbulence and NTM dynamics

Science.gov (United States)

Muraglia, M.; Agullo, O.; Poye, A.; Benkadda, S.; Horton, W.; Dubuit, N.; Garbet, X.; Sen, A.

2014-10-01

Magnetic reconnection is an issue for tokamak plasmas. Growing magnetic islands expel energetic particles from the plasma core leading to high energy fluxes in the SOL and may cause damage to the plasma facing components. The islands grow from seeds from the bootstrap current effects that oppose the negative delta-prime producing nonlinear island growth. Experimentally, the onset of NTM is quantified in terms of the beta parameter and the sawtooth period. Indeed, in experiments, (3;2) NTM magnetic islands are often triggered by sawtooth precursors. However (2;1) magnetic islands can appear without noticeable MHD event and the seed islands origin for the NTM growth is still an open question. Macroscale MHD instabilities (magnetic islands) coexist with micro-scale turbulent fluctuations and zonal flows which impact island dynamics. Nonlinear simulations show that the nonlinear beating of the fastest growing small-scale ballooning interchange modes on a low order rational surface drive a magnetic islands located on the same surface. The island size is found to be controlled by the turbulence level and modifies the NTM threshold and dynamics.

Introduced mammals on Western Indian Ocean islands

Directory of Open Access Journals (Sweden)

James C. Russell

2016-04-01

Full Text Available The diversity of introduced mammals and their introduction history varies greatly across the Western Indian Ocean (WIO islands, from ancient introductions in the past millennia on islands off the East coast of Africa where extant terrestrial native mammal communities exist, to very recent invasions in the past decades on islands in the Mascarene archipelago. We compile the distribution of 16 introduced mammal taxa on 28 island groups comprising almost 2000 islands. Through an exhaustive literature review and expert consultation process we recorded all mammal eradications, and species recoveries which could be attributed to introduced mammal eradication or control. All island groups have been invaded by mammals, and invasive cats and rats in particular are ubiquitous, but cultural contingency has also led to regional invasions by other mammals such as lemurs, civets and tenrecs. Mammal eradications have been attempted on 45 islands in the WIO, the majority in the Seychelles and Mauritius, and where successful have resulted in spectacular recovery of species and ecosystems. Invasive mammalian predator eradication or control in association with habitat management has led to improved conservation prospects for at least 24 species, and IUCN red-list down-listing of eight species, in the Mascarene Islands. Future island conservation prioritisation in the region will need to take account of global climate change and predicted sea-level rises and coastal inundation. Greater investment and prioritisation in island conservation in the region is warranted, given its high biodiversity values and the extent of invasions.

Analogue Modeling of Oblique Convergent Strike-Slip Faulting and Application to The Seram Island, Eastern Indonesia

Directory of Open Access Journals (Sweden)

Benyamin Sapiie

2014-12-01

Full Text Available DOI:10.17014/ijog.v1i3.189Sandbox experiment is one of the types of analogue modeling in geological sciences in which the main purpose is simulating deformation style and structural evolution of the sedimentary basin.  Sandbox modeling is one of the effective ways in conducting physically modeling and evaluates complex deformation of sedimentary rocks. The main purpose of this paper is to evaluate structural geometry and deformation history of oblique convergent deformation using of integrated technique of analogue sandbox modeling applying to deformation of Seram Fold-Thrust-Belt (SFTB in the Seram Island, Eastern Indonesia. Oblique convergent strike-slip deformation has notoriously generated area with structural complex geometry and pattern resulted from role of various local parameters that control stress distributions. Therefore, a special technique is needed for understanding and solving such problem in particular to relate 3D fault geometry and its evolution. The result of four case (Case 1 to 4 modeling setting indicated that two of modeling variables clearly affected in our sandbox modeling results; these are lithological variation (mainly stratigraphy of Seram Island and pre-existing basement fault geometry (basement configuration. Lithological variation was mainly affected in the total number of faults development.  On the other hand, pre-existing basement fault geometry was highly influenced in the end results particularly fault style and pattern as demonstrated in Case 4 modeling.  In addition, this study concluded that deformation in the Seram Island is clearly best described using oblique convergent strike-slip (transpression stress system.

Vancouver Island gas supply

International Nuclear Information System (INIS)

Des Brisay, C.

2005-01-01

Terasen Gas is pursuing alternatives for the supply of additional natural gas capacity to Vancouver Island. Its subsidiary, Terasen Gas (Vancouver Island) Inc. (TGVI), is responding to the need for delivery of increased gas supply and, is supporting plans for new gas-fired power generation on Vancouver Island. TGVI's proposal for new natural gas capacity involves a combination of compression and pipeline loops as well as the addition of a storage facility for liquefied natural gas (LNG) at Mt. Hayes to help manage price volatility. This presentation outlined the objectives and components of the resource planning process, including demand forecast scenarios and the preferred infrastructure options. tabs., figs

A thick lens of fresh groundwater in the southern Lihue Basin, Kauai, Hawaii, USA

Science.gov (United States)

Izuka, Scot; Gingerich, Stephen

2002-11-01

A thick lens of fresh groundwater exists in a large region of low permeability in the southern Lihue Basin, Kauai, Hawaii, USA. The conventional conceptual model for groundwater occurrence in Hawaii and other shield-volcano islands does not account for such a thick freshwater lens. In the conventional conceptual model, the lava-flow accumulations of which most shield volcanoes are built form large regions of relatively high permeability and thin freshwater lenses. In the southern Lihue Basin, basin-filling lavas and sediments form a large region of low regional hydraulic conductivity, which, in the moist climate of the basin, is saturated nearly to the land surface and water tables are hundreds of meters above sea level within a few kilometers from the coast. Such high water levels in shield-volcano islands were previously thought to exist only under perched or dike-impounded conditions, but in the southern Lihue Basin, high water levels exist in an apparently dike-free, fully saturated aquifer. A new conceptual model of groundwater occurrence in shield-volcano islands is needed to explain conditions in the southern Lihue Basin. Résumé. Dans le sud du bassin de Lihue (Kauai, Hawaii, USA), il existe une épaisse lentille d'eau souterraine douce dans une vaste région à faible perméabilité. Le modèle conceptuel conventionnel pour la présence d'eau souterraine à Hawaii et dans les autres îles de volcans en bouclier ne rend pas compte d'une lentille d'eau douce si épaisse. Dans ce modèle conceptuel, les accumulations de lave dont sont formés la plupart des volcans en bouclier couvrent de vastes régions à relativement forte perméabilité, avec des lentilles d'eau douce peu épaisses. Dans le sud du bassin de Lihue, les laves remplissant le bassin et les sédiments constituent une région étendue à faible conductivité hydraulique régionale, qui, sous le climat humide du bassin, est saturée presque jusqu'à sa surface; les surfaces pi

Wind energy potential on Malaysian Resort Islands: a case study of Tioman, Redang and Perhentian Island

International Nuclear Information System (INIS)

Kamaruzzaman Sopian

2000-01-01

Wind data collected at three east coast islands of Peninsular Malaysia namely Tioman, Redang and Perhentian Island were analyzed for the wind energy potential. The results were presented as Weibull distribution and preliminary analysis indicate that the site at Redang Island have the greatest potential with a mean power density of 85.1 w/m 2 at 10 meters above sea level. (Author)

Mesozoic architecture of a tract of the European-Iberian continental margin: Insights from preserved submarine palaeotopography in the Longobucco Basin (Calabria, Southern Italy)

Science.gov (United States)

Santantonio, Massimo; Fabbi, Simone; Aldega, Luca

2016-01-01

The sedimentary successions exposed in northeast Calabria document the Jurassic-Early Cretaceous tectonic-sedimentary evolution of a former segment of the European-Iberian continental margin. They are juxtaposed today to units representing the deformation of the African and Adriatic plates margins as a product of Apenninic crustal shortening. A complex pattern of unconformities reveals a multi-stage tectonic evolution during the Early Jurassic, which affected the facies and geometries of siliciclastic and carbonate successions deposited in syn- and post-rift environments ranging from fluvial to deep marine. Late Sinemurian/Early Pliensbachian normal faulting resulted in exposure of the Hercynian basement at the sea-floor, which was onlapped by marine basin-fill units. Shallow-water carbonate aprons and reefs developed in response to the production of new accommodation space, fringing the newborn islands which represent structural highs made of Paleozoic crystalline and metamorphic rock. Their drowning and fragmentation in the Toarcian led to the development of thin caps of Rosso Ammonitico facies. Coeval to these deposits, a thick (> 1 km) hemipelagic/siliciclastic succession was sedimented in neighboring hanging wall basins, which would ultimately merge with the structural high successions. Footwall blocks of the Early Jurassic rift, made of Paleozoic basement and basin-margin border faults with their onlapping basin-fill formations, are found today at the hanging wall of Miocene thrusts, overlying younger (Middle/Late Jurassic to Late Paleogene) folded basinal sediments. This paper makes use of selected case examples to describe the richly diverse set of features, ranging from paleontology to sedimentology, to structural geology, which are associated with the field identification of basin-margin unconformities. Our data provide key constraints for restoring the pre-orogenic architecture of a continental margin facing a branch of the Liguria-Piedmont ocean in the

Misrepresenting the Jordan River Basin

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Clemens Messerschmid

2015-06-01

Full Text Available This article advances a critique of the UN Economic and Social Commission for West Asia’s (ESCWA’s representation of the Jordan River Basin, as contained in its recently published Inventory of Shared Water Resources in Western Asia. We argue that ESCWA’s representation of the Jordan Basin is marked by serious technical errors and a systematic bias in favour of one riparian, Israel, and against the Jordan River’s four Arab riparians. We demonstrate this in relation to ESCWA’s account of the political geography of the Jordan River Basin, which foregrounds Israel and its perspectives and narratives; in relation to hydrology, where Israel’s contribution to the basin is overstated, whilst that of Arab riparians is understated; and in relation to development and abstraction, where Israel’s transformation and use of the basin are underplayed, while Arab impacts are exaggerated. Taken together, this bundle of misrepresentations conveys the impression that it is Israel which is the main contributor to the Jordan River Basin, Arab riparians its chief exploiters. This impression is, we argue, not just false but also surprising, given that the Inventory is in the name of an organisation of Arab states. The evidence discussed here provides a striking illustration of how hegemonic hydro-political narratives are reproduced, including by actors other than basin hegemons themselves.

Modeling the Response of Human Altered Natural Barrier Island Dynamics Along Assateague Island National Seashore to Climate Change

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Carroll, A.; McNamara, D.; Schupp, C.

2009-12-01

Assateague Island National Seashore comprises a long barrier island located off the coasts of Maryland and Virginia. Geological evidence suggests that over recent centuries Assateague Island has steadily transgressed up the continental shelf in response to rising sea level. More recently, the natural barrier island dynamics governing Assateague’s evolution have been altered by human activity in three ways: the construction of a jetty and the subsequent interruption of alongshore sediment transport on the north end of Assateague and both the ongoing and abandoned maintenance of a continuous dune system along portions of Assateague with the concomitant modification to overwash dynamics. It is unclear how these varied human alterations to the natural barrier island dynamics will influence the response of Assateague to climate change induced shifts in forcing such as increased rates of sea level rise and changing storm patterns. We use LIDAR detected morphological data of Assateague Island as initial conditions in an alongshore extended model for barrier island dynamics including beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms to explore the response of the various human altered segments of Assateague Island to forcing changes. Traditional models exploring barrier island evolution contain only cross-shore dynamics therefore lacking important alongshore-spatial dynamics in aeolian and surf zone sediment transport. Results show that including alongshore dynamics alter the steady state of Assateague relative to simulations that only include cross-shore dynamics. Results will also be presented exploring the potential for regime shifts in steady state behavior under various scenarios for the rate of sea level rise and storm climate and varying management strategies.

Terrestrial radiation measurements in Marshall Islands

International Nuclear Information System (INIS)

Gudiksen, P.H.

1978-01-01

With the prospect of habitation in the near future, radiological surveys were undertaken of Enewetak and Bikini Atolls to provide a basis for determining whether or not the atolls can be safely reinhabited. The surveys included all of the forty islands within Enewetak Atoll, but only the two principal islands, Bikini and Eneu Islands, of Bikini Atoll. These atolls were former U.S. nuclear weapons test sites in the Pacific. Integral parts of the surveys were the measurements of the distributions of radioactivity in the soil and the resulting gamma ray exposure rates for external dose estimation. Numerous soil samples were collected from both atolls for analysis by Ge (Li) gamma spectrometry and by wet chemistry techniques. At Enewetak Atoll the gamma exposure rates were measured by TLDs and a helicopter-borne array of Nal detectors, while at Bikini Atoll portable Nal detectors, pressurized ion-chambers, and TLDs were utilized. The predominant species measured in the soil samples collected from both atolls were 90 Sr, 239,240 Pu, 137 Cs and 60 Co with the latter two nuclides being the primary contributors to the gamma-ray exposure rates. The geographical distribution of the exposure rates measured on both atolls, was highly variable ranging from less than 1 μR/h on islands that had not been impacted radiologically by the testing program, to over 100 μR/h near weapon detonation sites. Thus, within Enewetak Atoll, the highest soil activities and gamma-ray exposure rates were measured on the northern islands, where the weapons testing had been most intense. Bikini Island exhibited contamination levels that were considerably higher than those on Eneu Island. Generally, the highest activity levels were observed within the island interiors or in proximity to ground zero sites, and could usually be related to the surrounding vegetation density. The island of Yvonne, within Enewetak Atoll, is the most severely contaminated land area. Particles containing as much as several

Globally threatened vertebrates on islands with invasive species.

Science.gov (United States)

Spatz, Dena R; Zilliacus, Kelly M; Holmes, Nick D; Butchart, Stuart H M; Genovesi, Piero; Ceballos, Gerardo; Tershy, Bernie R; Croll, Donald A

2017-10-01

Global biodiversity loss is disproportionately rapid on islands, where invasive species are a major driver of extinctions. To inform conservation planning aimed at preventing extinctions, we identify the distribution and biogeographic patterns of highly threatened terrestrial vertebrates (classified by the International Union for Conservation of Nature) and invasive vertebrates on ~465,000 islands worldwide by conducting a comprehensive literature review and interviews with more than 500 experts. We found that 1189 highly threatened vertebrate species (319 amphibians, 282 reptiles, 296 birds, and 292 mammals) breed on 1288 islands. These taxa represent only 5% of Earth's terrestrial vertebrates and 41% of all highly threatened terrestrial vertebrates, which occur in vertebrates was available for 1030 islands (80% of islands with highly threatened vertebrates). Invasive vertebrates were absent from 24% of these islands, where biosecurity to prevent invasions is a critical management tool. On the 76% of islands where invasive vertebrates were present, management could benefit 39% of Earth's highly threatened vertebrates. Invasive mammals occurred in 97% of these islands, with Rattus sp. as the most common invasive vertebrate (78%; 609 islands). Our results provide an important baseline for identifying islands for invasive species eradication and other island conservation actions that reduce biodiversity loss.

North Aegean island landscapes as ecomuseums: the case of Lesvos Island

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Evangelos Pavlis

2017-05-01

Full Text Available The main advantage of the Aegean islands, in generating national, regional, or international competitiveness, compared to the areas on the continental mainland, is their natural and cultural assets, their cultural landscapes. Consequently, the organized utilization of cultural heritage, rich biodiversity, and the unique Aegean landscape, could make the islands attractive as places to live or work and help them fulfill their sustainability goals. Ecomuseums are ‘in situ’ museums, aimed at local communities and managed by them, aiming at the interpretation, protection, utilization, and promotion of natural and cultural assets of a place, and at the economic revival of marginal regions through the combinational development of small-scale tourism, local manufacturing, and primary production sectors. They could function as laboratories of sustainable development. The island of Lesvos has been selected as a case study for such a potential ecomuseum.

Frog size on continental islands of the coast of Rio de Janeiro and the generality of the Island Rule.

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Raoni Rebouças

Full Text Available Island Rule postulated that individuals on islands tend to dwarfism when individuals from mainland populations are large and to gigantism when mainland populations present small individuals. There has been much discussion about this rule, but only few studies were carried out aiming to reveal this pattern for anurans. Our study focused on measuring the size of individuals on islands and to find a possible pattern of size modification for insular anurans. Individuals were collected on continental islands, measured and compared to mainland populations. We selected four species with different natural history aspects during these analyses. Island parameters were compared to size of individuals in order to find an explanation to size modification. Three of the four species presented size shifting on islands. Ololygon trapicheiroi and Adenomera marmorata showed dwarfism, Boana albomarginata showed gigantism and in Thoropa miliaris there was no evident size modification. Allometric analysis also revealed differential modification, which might be a result of different selective pressures on islands in respect of mainland populations. Regression model explained most of the size modification in B. albomarginata, but not for the other species. Our results indicate that previous assumptions, usually proposed for mammals from older islands, do not fit to the anurans studied here. We support the assumption that size modification on islands are population-specific. Hence, in B. albomarginata some factor associated to competition, living area and isolation time might likely be responsible for gigantism on islands.

Spatial and temporal controls of atoll island inundation: implications for urbanized atolls in the Marshall Islands.

Science.gov (United States)

Ford, M.; Becker, J. M.; Merrifield, M. A.

2012-12-01

Atoll islands are highly vulnerable to a range of inundation hazards. The impacts of such hazards are expected to be magnified as a result of continued sea-level rise. Both recent and historic inundation events provide unique insights into the requisite conditions necessary to initiate island inundation. A number of recent and historic inundation events are presented in order to examine the oceanographic and meteorological conditions driving inundation of a densely populated, urbanized atoll in the central Pacific. Analysis of inundation events suggests that a number of key drivers contribute to the spatial and temporal extent of island inundation, with unique degrees of predictability and resultant impact signatures apparent on island geomorphology and local anthropogenic activities. Results indicate three distinct drivers of inundation hazards exist. Firstly, tropical storms and typhoons elevate sea level through inverse barometric setup, wind setup and a range of wave driven processes and have caused considerable impact on atolls within the Marshall Islands. Secondly, super-elevated sea level conditions resulting from the combination of seasonal high tides and quasi-cyclical La Nina conditions drive inundation of low-lying lagoon facing coastal areas. Thirdly, long period swell conditions, typically generated by distant storms, can elevate reef-flat water levels through wave setup and infragravity wave oscillations. Such wave conditions can over wash the ocean-facing island ridge, often inundating large sections of the island. Reef-flat wave conditions are tidally modulated, with inundation events typically occurring around high tide. However, the two most recent destructive swell-driven inundation events have occurred while tide levels were significantly lower than spring tide levels, suggesting high water levels are not a necessary prerequisite for wave-driven inundation. The different modes of inundation are discussed and grounded within recent and historic

Chronic Liver Disease and Asian Americans/Pacific Islanders

Science.gov (United States)

... Cancer Asian/Pacific Islander Women Non-Hispanic White Women Asian/Pacific Islander/ Non-Hispanic White Ratio All Sites ... Cancer Asian/Pacific Islander Women Non-Hispanic White Women Asian/Pacific Islander/ Non-Hispanic White Ratio Liver & IBD* ...

Lithospheric Structure of the Yamato Basin Inferred from Trans-dimensional Inversion of Receiver Functions

Science.gov (United States)

Akuhara, T.; Nakahigashi, K.; Shinohara, M.; Yamada, T.; Yamashita, Y.; Shiobara, H.; Mochizuki, K.

2017-12-01

The Yamato Basin, located at the southeast of the Japan Sea, has been formed by the back-arc opening of the Japan Sea. Wide-angle reflection surveys have revealed that the basin has anomalously thickened crust compared with a normal oceanic crust [e.g., Nakahigashi et al., 2013] while deeper lithospheric structure has not known so far. Revealing the lithospheric structure of the Yamato Basin will lead to better understanding of the formation process of the Japan Sea and thus the Japanese island. In this study, as a first step toward understanding the lithospheric structure, we aim to detect the lithosphere-asthenosphere boundary (LAB) using receiver functions (RFs). We use teleseismic P waveforms recorded by broad-band ocean-bottom seismometers (BBOBS) deployed at the Yamato Basin. We calculated radial-component RFs using the data with the removal of water reverberations from the vertical-component records [Akuhara et al., 2016]. The resultant RFs are more complicated than those calculated at an on-land station, most likely due to sediment-related reverberations. This complexity does not allow either direct detection of a Ps conversion from the LAB or forward modeling by a simple structure composed of a handful number of layers. To overcome this difficulty, we conducted trans-dimensional Markov Chain Monte Carlo inversion of RFs, where we do not need to assume the number of layers in advance [e.g., Bodin et al., 2012; Sambridge et al., 2014]. Our preliminary results show abrupt velocity reduction at 70 km depth, far greater depth than the expected LAB depth from the age of the lithosphere ( 20 Ma, although still debated). If this low-velocity jump truly reflects the LAB, the anomalously thickened lithosphere will provide a new constraint on the complex formation history of the Japan Sea. Further study, however, is required to deny the possibility that the obtained velocity jump is an artificial brought by the overfitting of noisy data.

The role of basement inheritance faults in the recent fracture system of the inner shelf around Alboran Island, Western Mediterranean

Science.gov (United States)

Maestro-González, A.; Bárcenas, P.; Vázquez, J. T.; Díaz-Del-Río, V.

2008-02-01

Fractures associated with volcanic rock outcrops on the inner shelf of Alboran Island, Western Mediterranean, were mapped on the basis of a side-scan sonar mosaic. Absolute maximum fracture orientation frequency is NW SE to NNW SSE, with several sub-maxima oriented NNE SSW, NE SW and ENE WSW. The origin of the main fracture systems in Neogene and Quaternary rocks of the Alboran Basin (south Spain) appears to be controlled by older structures, namely NE SW and WNW ESE to NW SE faults which cross-cut the basement. These faults, pre-Tortonian in origin, have been reactivated since the early Neogene in the form of strike-slip and extensional movements linked to the recent stress field in this area. Fracture analysis of volcanic outcrops on the inner continental shelf of Alboran Island suggests that the shelf has been deformed into a narrow shear zone limited by two NE SW-trending, sub-parallel high-angle faults, the main orientation and density of which have been influenced by previous WNW ESE to NW SE basement fractures.

Spatial Preference Heterogeneity for Integrated River Basin Management: The Case of the Shiyang River Basin, China

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Fanus Asefaw Aregay

2016-09-01

Full Text Available Integrated river basin management (IRBM programs have been launched in most parts of China to ease escalating environmental degradation. Meanwhile, little is known about the benefits from and the support for these programs. This paper presents a case study of the preference heterogeneity for IRBM in the Shiyang River Basin, China, as measured by the Willingness to Pay (WTP, for a set of major restoration attributes. A discrete choice analysis of relevant restoration attributes was conducted. The results based on a sample of 1012 households in the whole basin show that, on average, there is significant support for integrated ecological restoration as indicated by significant WTP for all ecological attributes. However, residential location induced preference heterogeneities are prevalent. Generally, compared to upper-basin residents, middle sub-basin residents have lower mean WTP while lower sub-basin residents express higher mean WTP. The disparity in utility is partially explained by the difference in ecological and socio-economic status of the residents. In conclusion, estimating welfare benefit of IRBM projects based on sample responses from a specific sub-section of the basin only may either understate or overstate the welfare estimate.

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume I. Dalhart Basin

International Nuclear Information System (INIS)

1982-09-01

This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and highly variable prcipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

Solid waste management on small islands. The case of Green Island, Taiwan

Energy Technology Data Exchange (ETDEWEB)

Chen, M.C.; Ruijs, A.; Wesseler, J. [Environmental Economics and Natural Resources Group, Wageningen University, P.O. Box 8130, 6700 EW Wageningen (Netherlands)

2005-09-01

Municipalities of small islands have limited capacities for waste disposal. In the case of Green Island, Taiwan, continuing with business as usual would only allow the disposal of waste on the island for another 8 years. Three alternatives for solid waste management (SWM) are compared. The cost-effective solution is the one, which is the most expensive in the short run: continuing business as usual and introducing an incineration plant in the year 2010. The results indicate furthermore that deviations from optimal timing of investment only slightly change average annual costs. In the long run, the municipality can hardly avoid transporting waste to the mainland. By investing in an incineration plant, they can buy additional time to investigate alternative SWM strategies.

Basin Analysis and Petroleum System Characterisation of Western Bredasdorp Basin, Southern Offshore of South Africa: Insights from a 3d Crust-Scale Basin Model - (Phase 1)

Science.gov (United States)

Sonibare, W. A.; Scheck-Wenderoth, M.; Sippel, J.; Mikeš, D.

2012-04-01

In recent years, construction of 3D geological models and their subsequent upscaling for reservoir simulation has become an important tool within the oil industry for managing hydrocarbon reservoirs and increasing recovery rate. Incorporating petroleum system elements (i.e. source, reservoir and trap) into these models is a relatively new concept that seems very promising to play/prospect risk assessment and reservoir characterisation alike. However, yet to be fully integrated into this multi-disciplinary modelling approach are the qualitative and quantitative impacts of crust-scale basin dynamics on the observed basin-fill architecture and geometries. The focus of this study i.e. Western Bredasdorp Basin constitutes the extreme western section of the larger Bredasdorp sub-basin, which is the westernmost depocentre of the four southern Africa offshore sub-basins (others being Pletmos, Gamtoos and Algoa). These basins, which appear to be initiated by volcanically influenced continental rifting and break-up related to passive margin evolution (during the Mid-Late Jurassic to latest Valanginian), remain previously unstudied for crust-scale basin margin evolution, and particularly in terms of relating deep crustal processes to depo-system reconstruction and petroleum system evolution. Seismic interpretation of 42 2D seismic-reflection profiles forms the basis for maps of 6 stratigraphic horizons which record the syn-rift to post-rift (i.e. early drift and late drift to present-day seafloor) successions. In addition to this established seismic markers, high quality seismic profiles have shown evidence for a pre-rift sequence (i.e. older than Late Jurassic >130 Ma). The first goal of this study is the construction of a 3D gravity-constrained, crust-scale basin model from integration of seismics, well data and cores. This basin model is constructed using GMS (in-house GFZ Geo-Modelling Software) while testing its consistency with the gravity field is performed using IGMAS

CRED Gridded Bathymetry near Lisianski Island and Pioneer Bank (100-002), Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-002b is a 60-m ASCII grid of depth data collected near Lisianski Island and Pioneer Bank in the Northwestern Hawaiian Islands as of May 2003. This grid has...

Revisiting the Metaphor of the Island: Challenging "World Culture" from an Island Misunderstood

Science.gov (United States)

Rappleye, Jeremy

2015-01-01

This article revisits the newly "discovered" island that world culture theorists have repeatedly utilised to explain their theoretical stance, conceptual preferences and methodological approach. Yet, it seeks to (re)connect world culture with the real world by replacing their imagined atoll with a real one--the island-nation of Japan. In…

A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands.

Science.gov (United States)

Fisher, Robert N; Niukula, Jone; Watling, Dick; Harlow, Peter S

2017-06-06

The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji.  Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species.  One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province.  Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations.  We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.

A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands

Science.gov (United States)

Fisher, Robert N.; Niukula, Jone; Watling, Dick; Harlow, Peter S.

2017-01-01

The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji.  Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species.  One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province.  Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations.  We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.

Island forming processes in the Okavango Delta, Botswana

Science.gov (United States)

McCarthy, T. S.; Humphries, M. S.; Mahomed, I.; Le Roux, P.; Verhagen, B. Th.

2012-12-01

The Okavango Delta in Botswana is a large (40,000 km2) alluvial fan that is characterised by the presence of numerous tree-covered islands. Thought to originate from the mound-building activities of termites or through fluvial processes associated with development of scroll bars and inverted channels, islands have been shown to play an important role in the structure and functioning of the Delta through the creation of habitat diversity, focusing of nutrients, and disposal of toxic salts. This study investigates the processes responsible for the maintenance and growth of two such islands in the seasonal swamps. Transpiration by vegetation is shown to result in substantial increases in groundwater salinity beneath the islands, contributing to their growth through chemical precipitation. Detailed chemical analyses revealed that the precipitation of magnesian calcite and silica within the island soils contributes 30-40% of the total island volume. Isotopic analyses of carbonate samples show that vegetation plays an important role in providing carbon for carbonate precipitation. Variations in δ13C carbonate values appear to reflect the relative proportion of C3 to C4 plants on the island, with C4 species becoming more dominant toward island centres in response to increases in groundwater salinity. The study suggests that continued island growth is also related to the deposition of aerosols and the accumulation of dust preferentially on islands and possibly to ongoing termite activity. Tall trees that characterise the island margins trap dust carried from the floodplains, resulting particularly in the lateral growth of islands. Islands in the Okavango are considered to be the product of long-term aggradation processes, with the two islands studied estimated to be in the order of tens of thousands of years old.

The evolution and performance of river basin management in the Murray-Darling Basin

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Andrew Ross

2016-09-01

Full Text Available We explore bioregional management in the Murray-Darling Basin (MDB in Australia through the institutional design characteristics of the MDB River Basin Organization (RBO, the actors and organizations who supported and resisted the establishment of the RBO, and the effectiveness of the RBO. During the last 25 years, there has been a major structural reform in the MDB RBO, which has changed from an interstate coordinating body to an Australian government agency. Responsibility for basin management has been centralized under the leadership of the Australian government, and a comprehensive integrated Basin plan has been adopted. The driving forces for this centralization include national policy to restore river basins to sustainable levels of extraction, state government difficulties in reversing overallocation of water entitlements, the millennium drought and its effects, political expediency on the part of the Australian government and state governments, and a major injection of Australian government funding. The increasing hierarchy and centralization of the MDB RBO does not follow a general trend toward multilevel participative governance of RBOs, but decentralization should not be overstated because of the special circumstances at the time of the centralization and the continuing existence of some decentralized elements, such as catchment water plans, land use planning, and water quality. Further swings in the centralization-decentralization pendulum could occur. The MDB reform has succeeded in rebalancing Basin water allocations, including an allocation for the environment and reduced diversion limits. There are some longer term risks to the implementation of reform, including lack of cooperation by state governments, vertical coordination difficulties, and perceived reductions in the accountability and legitimacy of reform at the local level. If implementation of the Basin plan is diverted or delayed, a new institution, the Commonwealth

Sustaining Exploration in Mature Basins

International Nuclear Information System (INIS)

Bayo, A.

2002-01-01

Exploration is a business like any other business driven by opportunity, resources and expectation of profit. Therefore, exploration will thrive anywhere the opportunities are significant, the resources are available and the outlook for profit (or value creation) is good. To sustain exploration activities anywhere, irrespective of the environment, there must be good understanding of the drivers of these key investment criteria. This paper will examine these investment criteria as they relate to exploration business and address the peculiarity of exploration in mature basin. Mature basins are unique environment that lends themselves a mix of fears, paradigms and realities, particularly with respect to the perception of value. To sustain exploration activities in a mature basin, we need to understand these perceptions relative to the true drivers of profitability. Exploration in the mature basins can be as profitable as exploration in emerging basins if the dynamics of value definition-strategic and fiscal values are understood by operators, regulators and co ventures alike. Some suggestions are made in this presentation on what needs to be done in addressing these dynamic investment parameters and sustaining exploration activities in mature basins

Elastic energies of coherent germanium islands on silicon

International Nuclear Information System (INIS)

Vanderbilt, D.; Wickham, L.K.

1991-01-01

Motivated by recent observations of coherent Ge island formation during growth of Ge on Si (100), the authors of this paper have carried out a theoretical study of the elastic energies associated with the evolution of a uniform strained overlayer as it segregates into coherent islands. In the context of a two-dimensional model, the authors have explored the conditions under which coherent islands may be energetically favored over both uniform epitaxial films and dislocated islands. The authors find that if the interface energy (for dislocated islands) is more than about 15% of the surface energy, then there is a range of island sizes for which the coherent island structure is preferred

L-Reactor 186-basin cleaning alternatives

International Nuclear Information System (INIS)

Turcotte, M.D.S.

1983-01-01

Operation of L Reactor will necessitate annual cleaning of the L Area 186 basins. Alternatives are presented for sediment discharge due to 186-basin cleaning activities as a basis for choosing the optimal cleaning method. Current cleaning activities (i.e. removal of accumulated sediments) for the P, C and K-Area 186 basins result in suspended solids concentrations in the effluent waters above the NPDES limits, requiring an exemption from the NPDES permit for these short-term releases. The objective of mitigating the 186-basin cleaning activities is to decrease the suspended solids concentrations to within permit limits while continuing satisfactory operation of the basins

Crustal characteristic variation in the central Yamato Basin, Japan Sea back-arc basin, deduced from seismic survey results

Science.gov (United States)

Sato, Takeshi; No, Tetsuo; Miura, Seiichi; Kodaira, Shuichi

2018-02-01

The crustal structure of the Yamato Bank, the central Yamato Basin, and the continental shelf in the southern Japan Sea back-arc basin is obtained based on a seismic survey using ocean bottom seismographs and seismic shot to elucidate the back-arc basin formation processes. The central Yamato Basin can be divided into three domains based on the crustal structure: the deep basin, the seamount, and the transition domains. In the deep basin domain, the crust without the sedimentary layer is about 12-13 km thick. Very few units have P-wave velocity of 5.4-6.0 km/s, which corresponds to the continental upper crust. In the seamount and transition domains, the crust without the sedimentary layer is about 12-16 km thick. The P-wave velocities of the upper and lower crusts differs among the deep basin, the seamount, and the transition domains. These results indicate that the central Yamato Basin displays crustal variability in different domains. The crust of the deep basin domain is oceanic in nature and suggests advanced back-arc basin development. The seamount domain might have been affected by volcanic activity after basin opening. In the transition domain, the crust comprises mixed characters of continental and oceanic crust. This crustal variation might represent the influence of different processes in the central Yamato Basin, suggesting that crustal development was influenced not only by back-arc opening processes but also by later volcanic activity. In the Yamato Bank and continental shelf, the upper crust has thickness of about 17-18 km and P-wave velocities of 3.3-4.1 to 6.6 km/s. The Yamato Bank and the continental shelf suggest a continental crustal character.

Evolution of an intra-oceanic island arc during the late Silurian to late Devonian, New England fold belt

International Nuclear Information System (INIS)

Offler, R.; Gamble, J.

2002-01-01

Geochemical studies of volcanic rocks in the Gamilaroi terrane and Calliope Volcanic Assemblage, New England Fold Belt, eastern Australia, indicate that the setting in which these rocks formed changed in both space and time. The Upper Silurian to Middle Devonian basalts of the Gamilaroi terrane show flat to slightly light rare-earth element (LREE) depleted chondrite normalised patterns, depletion of high field strength elements (HFSE) relative to N-MORB, low Ti/V and high Ti/Zr ratios, high Ni, Cr and large-ion lithophile element (LILE) contents, features characteristic of intra-oceanic island arc basaltic magmas. They are associated with low-K, less mafic volcanics, showing moderate LREE enrichment, low Nb and Y contents and Rb/Zr ratios. The depletion of HFSE in the basalts indicates that the magmas were derived from a refractory source in a supra-subduction zone setting. The presence of such a zone implies that the arc was associated with a backarc basin, the location of which was to the west where a wide backarc region existed from the Middle Silurian. This polarity of arc and backarc basin suggests that the subduction zone dipped to the west. In contrast to their older counterparts, Middle to Upper Devonian basalts of the Gamilaroi terrane have MORB-like chondrite normalised patterns and higher Ti and lower LILE contents. Moreover, they have low Ti/Zr ratios and MORB-like Ti/V ratios and HFSE contents, features typical of backarc basins. Dolerites of the Gamilaroi terrane also have predominantly backarc basin signatures. These features suggest that both the basalts and dolerites have been emplaced in an extensional environment produced during the rifting of the intra-oceanic island arc lithosphere. A progressive increase in Ti/V ratios, and TiO 2 and Fe 2 O 3 contents at constant MgO, of stratigraphically equivalent basalts, towards the north-northwest part of the belt, is consistent with either greater extension to the north or melting of a more fertile magma

Shape and coarsening dynamics of strained islands

DEFF Research Database (Denmark)

Schifani, Guido; Frisch, Thomas; Argentina, Mederic

2016-01-01

and numerically the formation of an equilibrium island using a two-dimensional continuous model. We have found that these equilibrium island-like solutions have a maximum height h_{0} and they sit on top of a flat wetting layer with a thickness h_{w}. We then consider two islands, and we report that they undergo...... and leads to the shrinkage of the smallest island. Once its height becomes smaller than a minimal equilibrium height h_{0}^{*}, its mass spreads over the entire system. Our results pave the way for a future analysis of coarsening of an assembly of islands....

Review of islanding detection methods for distributed generation

DEFF Research Database (Denmark)

Chen, Zhe; Mahat, Pukar; Bak-Jensen, Birgitte

2008-01-01

This paper presents an overview of power system islanding and islanding detection techniques. Islanding detection techniques, for a distribution system with distributed generation (DG), can broadly be divided into remote and local techniques. A remote islanding detection technique is associated...

Effect of island shape on dielectrophoretic assembly of metal nanoparticle chains in a conductive-island-based microelectrode system

International Nuclear Information System (INIS)

Ding, Haitao; Shao, Jinyou; Ding, Yucheng; Liu, Weiyu; Li, Xiangming; Tian, Hongmiao; Zhou, Yaopei

2015-01-01

Highlights: • Conductive island shape influences the dynamic process occurring in DEP assembly of 10 nm gold nanoparticles in a conductive-island-based microelectrode system. • The DEP-assembled nanoparticle wires form a straighter conduction path with the increase in the geometric angle of conductive island tip. • The different island shapes distort the DEP force distribution and increase the local electrothermally induced fluid flow to different extents, which is important for the morphology and electrical conductance quality of the DEP-assembled metal nanoparticle chains. - Abstract: The electrical conduction quality of an electric circuit connection formed by dielectrophoretic (DEP)-assembled metal nanoparticle wires between small conductive elements plays a significant role in electronic devices. One of the major challenges for improving the electrical conductance of nanowires is optimizing their geometric morphology. So far, the electrical conduction quality has been enhanced by optimizing the AC frequency and conductivity of nanoparticle suspensions. Herein, the effect of the conductive island shapes on the dynamic process occurring in a DEP assembly of 10 nm gold nanoparticles was investigated in a conductive-island-based microelectrode system. The nanoparticle wires between the microelectrodes were assembled in situ from colloidal suspensions. The wires were grown in a much straighter route by increasing the geometric angle of the conductive-island tip. To validate the experiments, the effects of mutual DEP interactions and electrothermally induced fluid flow on the dynamic behavior of particle motion for different island geometric configurations in the conductive-island-based microelectrode system were determined by numerical simulations. The simulation results are consistent with those of experiments. This indicates that different conductive island shapes change the distribution of DEP force and increase the electrothermally induced fluid flow to

Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China

Science.gov (United States)

Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan

2017-12-01

The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

Lower Tertiary Sedimentary Turbidite Facies at the Chicontepec Basin, East-Central Mexico

Directory of Open Access Journals (Sweden)

Santillán-Piña N.

2011-07-01

Full Text Available The study area comprises the northwestern portion of the Chicontepec Basin at southeastern San Luis Potosí and northeastern Hidalgo States. At the stratigraphy sequences of the Chicontepec Formation from Lower Paleocene in isolated outocrops, were herein interpreted two major sedimentary sub-environments into the fan model: the middle and the external sedimentary settings; the applied criteria for their identification were: (a lithostratigraphic (thickness, geometry and distribution; (b internal and external primary sedimentary structures, and (c intra-formational deformation structures. The sedimentary facies are composed of siliciclastic and calcareous particles sourced from the Sierra Madre Oriental, western; the Tuxpan paleo-island, eastern; and from the Teziutlan Massif, southern; the sediments were massively transported by slideing, slumping, flow debris and turbidity currents, then deposited as massive, tabular, lenticular and lobely in shape at the slope foot and on the sea marine floor.

Environmental assessment for the resettlement of Eneu Island on Bikini Atoll, Republic of the Marshall Islands

International Nuclear Information System (INIS)

Maragos, J.E.; Agegian, Catherine

1986-01-01

This environmental assessment evaluates various alternatives to return the Bikini people to their homeland on Bikini Atoll. Eneu Island was spared the heavy nuclear contamination that rendered Bikini Island, the largest and main inhabitable island on the atoll, presently unsuitable for resettlement. The economic, social, technical and environmental consequences of all alternatives were compared, and alternative sites, purposes and scales for resettlement were included in the analysis. This environmental assessment explores these alternatives in detail and concludes that the resettlement of Eneu Island by some of the Bikini people at this time will not result in significant adverse effects to the environment nor will it foreclose any other full scale resettlement option involving the cleanup of Bikini Atoll. In addition, it concludes that the resettlement of Eneu can be accomplished independently from the planned cleanup and resettlement of Bikini Island. Plans and combination of plans involving the early resettlement of Eneu are fully feasible and implementable at this time. (author)

Environmental assessment for the resettlement of Eneu Island on Bikini Atoll, Republic of the Marshall Islands

Energy Technology Data Exchange (ETDEWEB)

Maragos, J E [Environmental Resources Section, U.S. Army Corps of Engineers, Pacific Ocean Division, HI (United States); Agegian, Catherine [University of Hawaii, Department of Oceanography, Honolulu, HI (United States)

1986-07-01

This environmental assessment evaluates various alternatives to return the Bikini people to their homeland on Bikini Atoll. Eneu Island was spared the heavy nuclear contamination that rendered Bikini Island, the largest and main inhabitable island on the atoll, presently unsuitable for resettlement. The economic, social, technical and environmental consequences of all alternatives were compared, and alternative sites, purposes and scales for resettlement were included in the analysis. This environmental assessment explores these alternatives in detail and concludes that the resettlement of Eneu Island by some of the Bikini people at this time will not result in significant adverse effects to the environment nor will it foreclose any other full scale resettlement option involving the cleanup of Bikini Atoll. In addition, it concludes that the resettlement of Eneu can be accomplished independently from the planned cleanup and resettlement of Bikini Island. Plans and combination of plans involving the early resettlement of Eneu are fully feasible and implementable at this time. (author)

Assessing qualitative long-term volcanic hazards at Lanzarote Island (Canary Islands)

Science.gov (United States)

Becerril, Laura; Martí, Joan; Bartolini, Stefania; Geyer, Adelina

2017-07-01

Conducting long-term hazard assessment in active volcanic areas is of primary importance for land-use planning and defining emergency plans able to be applied in case of a crisis. A definition of scenario hazard maps helps to mitigate the consequences of future eruptions by anticipating the events that may occur. Lanzarote is an active volcanic island that has hosted the largest (> 1.5 km3 DRE) and longest (6 years) eruption, the Timanfaya eruption (1730-1736), on the Canary Islands in historical times (last 600 years). This eruption brought severe economic losses and forced local people to migrate. In spite of all these facts, no comprehensive hazard assessment or hazard maps have been developed for the island. In this work, we present an integrated long-term volcanic hazard evaluation using a systematic methodology that includes spatial analysis and simulations of the most probable eruptive scenarios.

Spatio-Temporal Dynamics of a Coastal Island Using Geospatial Techniques: A Case in Hatiya Island, Bangladesh

Science.gov (United States)

Ramjan, S.; Mahmud, M. S.; Hossain, M. A.; Hasan, M.; Ashrafi, Z. M.

2016-12-01

Bangladesh is recognized for its high vulnerability to sea level rise (SLR). SLR directly and indirectly (by altering morphology of river estuary) accelerates erosion processes, washes out the loose materials of the coast and coastal islands. Hatiya, highly populated coastal island, located in Meghna river estuary is under severe threat of coastal erosion, which has not been quantified yet. The accurate mapping of the shoreline and coastal changes are very important for adopting conservation measures e.g. protection of human life, property and the natural environment. The objectives of the present study are to use remote sensing and Geographical Information System techniques to evaluate spatial and temporal changes in the shoreline and coastal land area of the Hatiya Island between the year of 1985 and 2016 from multi-temporal satellite images, i.e. assessing shifting of the shoreline position through digital shoreline analysis besides the erosion-accretion measurements. Study reveals that about 67 square kilometer areas has been lost between 1985 and 2016 which was about 17 percent of original area (1985). Erosion mainly took place in northern, north-western banks of the island. In these areas, the landward movement and rate of the shoreline were higher with a highest value of the net shoreline movement (NSM) around 6.2 km. Erosion rate is significant in exposed part of the island where tidal water pressure, shoreline configuration, loose bank materials and steep slope were observed. However, the accretion was noticed in recent years (2010-2016) in southern part of the island where slopes were gentle, perhaps due to backwash sediment deposition. As erosion process is prominent in this island, significant amounnt of usable land was lost. Therefore, local livelihood pattern has changed that has noticable effect on local economy. By quantifying the erosion-accretion rate, livelihood planning can be initiated in climatically threated vulnerable islands.

Spent LWR fuel storage costs: reracking, AR basins, and AFR basins

International Nuclear Information System (INIS)

1980-01-01

Whenever possible, fuel storage requirements will be met by reracking existing reactor basins and/or transfer of fuel to available space in other reactor basins. These alternatives represent not only the lowest cost storage options but also the most timely. They are recognized to face environmental and regulatory obstacles. However, such obstacles should be less severe than those that would be encountered with AR or AFR basin storage. When storage requirements cannot be met by the first two options, the least costly alternative for most utilities will be use of a Federal AFR. Storage costs of $100,000 to $150,000 MTU at a AFR are less costly than charges of up to $320,000/MTU that could be incurred by the use of AR basins. AFR storage costs do not include transportation from the reactor to the AFR. This cost would be paid by the utility separately. Only when a utility requires annual storage capacity for 100 MTU of spent fuel can self-storage begin to compete with AFR costs. The large reactor complexes discharging these fuel quantities are not currently those that require relief from fuel storage problems

Geologic Basin Boundaries (Basins_GHGRP) GIS Layer

Data.gov (United States)

U.S. Environmental Protection Agency — This is a coverage shapefile of geologic basin boundaries which are used by EPA's Greenhouse Gas Reporting Program. For onshore production, the "facility" includes...

Hydroclimatology of the Missouri River basin

Science.gov (United States)

Wise, Erika K.; Woodhouse, Connie A.; McCabe, Gregory; Pederson, Gregory T.; St. Jacques, Jeannine-Marie

2018-01-01

Despite the importance of the Missouri River for navigation, recreation, habitat, hydroelectric power, and agriculture, relatively little is known about the basic hydroclimatology of the Missouri River basin (MRB). This is of particular concern given the droughts and floods that have occurred over the past several decades and the potential future exacerbation of these extremes by climate change. Here, observed and modeled hydroclimatic data and estimated natural flow records in the MRB are used to 1) assess the major source regions of MRB flow, 2) describe the climatic controls on streamflow in the upper and lower basins , and 3) investigate trends over the instrumental period. Analyses indicate that 72% of MRB runoff is generated by the headwaters in the upper basin and by the lowest portion of the basin near the mouth. Spring precipitation and temperature and winter precipitation impacted by changes in zonal versus meridional flow from the Pacific Ocean play key roles in surface water supply variability in the upper basin. Lower basin flow is significantly correlated with precipitation in late spring and early summer, indicative of Atlantic-influenced circulation variability affecting the flow of moisture from the Gulf of Mexico. Although increases in precipitation in the lower basin are currently overriding the effects of warming temperatures on total MRB flow, the upper basin’s long-term trend toward decreasing flows, reduction in snow versus rain fraction, and warming spring temperatures suggest that the upper basin may less often provide important flow supplements to the lower basin in the future.

Rising sea levels and small island states

International Nuclear Information System (INIS)

Leatherman, S.P.

1994-01-01

A review is given of the problems small island nations face with respect to sea level rise caused by global warming. Many small island nations are very vulnerable to sea level rise. Particularly at risk are coral reef atolls, which are generally quite small, lie within three metres of current sea levels, and have no land at higher elevations to relocate populations and economic activity. Volcanic islands in the Pacific have high ground, but it is largely rugged, high relief and soil-poor. The most vulnerable islands are those that consist entirely of atolls and reef islands, such as Kirabai, Maldives, Tokelau and Tuvalu. Small island states, which by themselves have little power or influence in world affairs, have banded together to form the Strategic Alliance of Small Island States (AOSIS). This alliance had grown to include 42 states by the time of the 1992 U.N. Earth Summit. Although the greenhouse effect is mainly caused by industrial nations, developing countries will suffer the most from it. Choices of response strategy will depend on environmental, economic and social factors. Most small island nations do not have the resources to fight sea level rise in the way that the Dutch have. Retreat can occur as a gradual process or as catastrophic abandonment. Prohibiting construction close to the water's edge is a good approach. Sea level histories for each island state should be compiled and updated, island geomorphology and settlement patterns should be surveyed to determine risk areas, storm regimes should be determined, and information on coastal impacts of sea level rise should be disseminated to the public

Vicia vulcanorum (Fabaceae a new species from the island of Lanzarote (Canary Islands

Directory of Open Access Journals (Sweden)

Morales-Mateos, J. B.

2012-12-01

Full Text Available Vicia vulcanorum J. Gil & M. L. Gil (Fabaceae, a new species of subg. Cracca (Dumort. Peterm., sect. Cracca Dumort. is described and illustrated from the island of Lanzarote, Canary Islands, north-west of Africa. It is related to and compared with Vicia cirrhosa C. Sm. ex Webb & Berthel. and Vicia filicaulis Webb & Berthel., two endemic species from the western and central group of the Canary Islands, and Vicia ferreirensis Goyder, an endemic species from Porto Santo Island, Madeira Archipelago.Se describe e ilustra Vicia vulcanorum J. Gil & M. L. Gil (Fabaceae, una nueva especie y endemismo de la isla de Lanzarote, Islas Canarias, perteneciente al subg. Cracca (Dumort. Peterm., sect. Cracca Dumort. Se encuentra relacionada y es comparada con Vicia cirrhosa C. Sm. ex Webb & Berthel. y Vicia filicaulis Webb & Berthel., especies endémicas de las islas centrales y occidentales del archipiélago canario, y con Vicia ferreirensis Goyder, especie endémica de la isla de Porto Santo, en el archipiélago de Madeira.

Seasonal and interannual variability of dissolved oxygen around the Balearic Islands from hydrographic data

Science.gov (United States)

Balbín, R.; López-Jurado, J. L.; Aparicio-González, A.; Serra, M.

2014-10-01

Oceanographic data obtained between 2001 and 2011 by the Spanish Institute of Oceanography (IEO, Spain) have been used to characterise the spatial distribution and the temporal variability of the dissolved oxygen around the Balearic Islands (Mediterranean Sea). The study area includes most of the Western Mediterranean Sea, from the Alboran Sea to Cape Creus, at the border between France and Spain. Dissolved oxygen (DO) at the water surface is found to be in a state of equilibrium exchange with the atmosphere. In the spring and summer a subsurface oxygen supersaturation is observed due to the biological activity, above the subsurface fluorescence maximum. Minimum observed values of dissolved oxygen are related to the Levantine Intermediate Waters (LIW). An unusual minimum of dissolved oxygen concentrations was also recorded in the Alboran Sea Oxygen Minimum Zone. The Western Mediterranean Deep Waters (WMDW) and the Western Intermediate Waters (WIW) show higher values of dissolved oxygen than the Levantine Intermediate Waters due to their more recent formation. Using these dissolved oxygen concentrations it is possible to show that the Western Intermediate Waters move southwards across the Ibiza Channel and the deep water circulates around the Balearic Islands. It has also been possible to characterise the seasonal evolution of the different water masses and their dissolved oxygen content in a station in the Algerian sub-basin.

Neoclassical islands on COMPASS-D

International Nuclear Information System (INIS)

Gates, D.A.; Lloyd, B.; Morris, A.W.; McArdle, G.; O'Brien, M.R.; Valovic, M.; Warrick, C.D.; Wilson, H.R.

1997-01-01

Neoclassical magnetic islands are observed to limit the achievable β in COMPASS-D low collisionality single null divertor tokamak plasmas with ITER-like geometry (R 0 = 0.56 m, B 0 1.2 T, I p = 120-180 kA, κ = 1.6, ε = 0.3). The limiting β is typically well below that expected from ideal instabilities with maximum βN in the range of 1.6 to 2.1. The plasma is heated with up to 1.8 MW of 60 GHz electron cyclotron resonance heating (ECRH) at the second harmonic with X mode polarization. The time history of the measured island width is compared with the predictions of neoclassical tearing mode theory, with good agreement between theory and experiment. The measured islands have a threshold width below which the mode will not grow. The density scaling of the point of onset of the measured instabilities is compared with two theories that predict a threshold island width for the onset of neoclassical tearing modes. Applied resonant helical error fields are used to induce islands in collisionality regimes wherein the neoclassical islands do not occur naturally, allowing the study of the behaviour of neoclassical tearing modes in this regime. The critical β for the onset of neoclassical tearing modes is seen to be ∼3 times higher in the naturally stable region. This observation is compared with the predictions of both threshold theories. A simple expression for the q scaling of the maximum achievable β N in the presence of neoclassical tearing modes is derived on the basis of the assumption of a maximum allowable island width. The predicted q scaling of this β limit is compared with data from a q scan, and the results are in good agreement. (author)

Wind energy in Mediterranean Basin

International Nuclear Information System (INIS)

Gaudiosi, G.

1991-01-01

In its examination of wind energy potential in the Mediterranean Basin, this paper provides brief notes on the Basin's geography; indicates power production and demand; describes the area's wind characteristics and wind monitoring activities; illustrates wind velocity distributions; estimates local wind power production potential; reviews the Basin's wind energy marketing situation and each bordering country's wind energy programs; surveys installed wind energy farms; and assesses national research and commercialization efforts

Immigration and the competitiveness of an island tourism destination: a knowledge-based reputation analysis of Lanzarote, Canary Islands

Directory of Open Access Journals (Sweden)

Desiderio Juan García-Almeida

2017-05-01

Full Text Available This paper sheds light on the relationship between immigration and tourism competitiveness on the island of Lanzarote through the analysis of reputation from the demand perspective. The tourists’ knowledge about news on immigration from a destination, their contact with immigrants in the area, and the influence of the presence of immigrants there are studied, as all these factors can have a major impact on island competitiveness in tourism. The empirical work has been conducted with a survey of tourists on Lanzarote, Canary Islands, Spain. A total of 359 valid questionnaires were obtained. Results show a relatively low impact and retention of immigration news about the destination, and a low perceived contact with non-European immigrants when visiting the island. Moreover, tourists tend to recognize the positive value created by immigrants on the island, though some negative effects are also indicated. Finally, immigration seems to have a positive impact on the tourist’s global satisfaction and loyalty to the island destination.

Influence of magmatic volatiles on boron isotope compositions in vent fluids from the Eastern Manus Basin, Papua New Guinea

Science.gov (United States)

Wilckens, F. K.; Kasemann, S.; Bach, W.; Reeves, E. P.; Meixner, A.; Seewald, J.

2016-12-01

In this study we present boron (B), lithium (Li) and strontium (Sr) concentrations and isotopic composition of submarine hydrothermal fluids collected in 2006 and 2011 from PACMANUS, DESMOS and SuSu Knolls vent fields located in the Eastern Manus Basin [1,2]. Hydrothermal vent fluids within the Eastern Manus Basin range from high-temperature black smoker fluids to low-temperature diffuse fluids and acid-sulfate fluids. In general, the different fluid types show variable water-rock ratios during water-rock interaction and different inputs of magmatic volatiles. End-member black smoker fluids, which have in general high temperatures (mostly higher than 280°C) and pH values higher than 2 (measured at 25°C) are characterized by low δ7Li values (3.9 to 5.9‰) and 87Sr/86Sr ratios (0.704 to 0.705) similar to the values for island arc basalts. These results suggest low water-rock ratios during hydrothermal circulation. B concentrations and isotopic compositions in these fluids range from 1.0 to 2.6μM and 13 to 20‰, respectively. These data match with other vent fluids from island arc settings in the Western Pacific and plot in a B versus δ11B diagram on a two-component mixing line between seawater and island arc basalts [3]. Sr and Li isotopic composition of white smoker and acid-sulfate fluids overlap generally with the isotopic ratios for the black smoker fluids. However, in some fluids Sr isotope ratios are up to 0.709 near seawater composition suggesting higher water-rock ratios during water-rock interaction. B concentrations and isotope ratios in the white smoker and acid-sulfate fluids range from 0.6 to 2.2μM and 9 to 16‰, respectively which are lower compared with the values of black smoker fluids. In addition, these fluids do not fit on the mixing line between seawater and island arc basalt, and define another mixing trend in a B versus δ11B diagram. To explain this contradictory trend, a third mixing endmember is required that shifts B concentrations

Backscatter 0.5m TIFF Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands. NOAA's NOS/NCCOS/CCMA Biogeography...

A comparison of controls on freshwater lens morphology of small carbonate and siliciclastic islands: examples from barrier islands in Florida, USA

Science.gov (United States)

Schneider, James C.; Kruse, Sarah E.

2003-12-01

The freshwater lens on small islands may easily be overexploited or polluted due to dense development combined with improper management. On small carbonate islands complexities in fresh groundwater distribution are most commonly driven by geologic heterogeneities and their attendant impact on permeability and effective recharge patterns. Siliciclastic islands (composed primarily of quartz sand and other silica-based minerals) have been less well studied, and fewer common patterns of lens development have emerged. On some siliciclastic islands correlations between geology and lens geometries are weak; on these islands the freshwater lens geometry may be largely determined by how vegetation and terrain elevation affect recharge. Other factors such as unequal sea level on opposite sides of an island and transient variability (natural island migration and climate variability) may also be locally significant. Two barrier islands in the northeast Gulf of Mexico fall into this category of siliciclastic islands. Relationships between lens morphology, geology, vegetation, terrain, and sea level and transient effects are documented on St George Island and Dog Island, FL. Patterns of fresh groundwater occurrence are deduced with electrical and electromagnetic geophysical methods. Although isolated cores show geologic layering that could potentially control freshwater lens development, ground penetrating radar and seismic surveys show no evidence of semi-continuous subhorizontal layering. Inferred lens thickness and geometry suggests that site geology plays a relatively minor role as a cause of complexity in lens formation. Lens geometry does appear to be related to terrain and vegetation variability, and further complicated by the continuous reforming of these islands by coastal processes and human development.

Checklist of the ants (Hymenoptera, Formicidae of the Solomon Islands and a new survey of Makira Island

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Eli Sarnat

2013-01-01

Full Text Available The intent of this paper is to facilitate future research of the Solomon Islands ant fauna by providing the first comprehensively researched species inventory in over 75 years. The species list presented here includes the names of all ant species recorded from the islands that are available in the literature together with specimen records from several museum collections and new records from our 2008 Makira field expedition. All the names of described species presented are valid in accordance with the most recent Formicidae classification. In total, the checklist is composed of 237 species and subspecies (including 30 morphospecies in 59 genera representing nine subfamilies. We report that the recent field expedition added 67 new species records to Makira and 28 new species records to the Solomon Islands. Our research recovered species occurrence records for 32 individual islands and five island groups. The five islands with the highest number of recorded species are: Makira (142 spp., Guadalcanal (107 spp., Malaita (70 spp., Santa Isabel (68 spp., and Rennell (66 spp.. Based on our results, we discuss the taxonomic composition of the archipelago’s ant fauna, which islands are most in need of additional sampling, and the importance of establishing biodiversity baselines before environmental threats such as the invasive ant Wasmannia auropunctata cause irrevocable harm to the native biodiversity.

Reduction of Islands in Full-pressure Stellarator Equilibria

International Nuclear Information System (INIS)

Hudson, S.R.; Monticello, D.A.; Reiman, A.H.

2001-01-01

The control of magnetic islands is a crucial issue in designing Stellarators. Islands are associated with resonant radial magnetic fields at rational rotational-transform surfaces and can lead to chaos and poor plasma confinement. In this article, we show that variations in the resonant fields of a full-pressure stellarator equilibrium can be related to variations in the boundary via a coupling matrix, and inversion of this matrix determines a boundary modification for which the island content is significantly reduced. The numerical procedure is described and the results of island optimization are presented. Equilibria with islands are computed using the Princeton Iterative Equilibrium Solver, and resonant radial fields are calculated via construction of quadratic-flux-minimizing surfaces. A design candidate for the National Compact Stellarator Experiment [Phys. Plasmas 8, 2001], which has a large island, is used to illustrate the technique. Small variations in the boundary shape are used to reduce island size and to reverse the phase of a major island chain

36 CFR 13.1178 - Closed waters, islands and other areas.

Science.gov (United States)

2010-07-01

... southeast of Flapjack Island; or Eider Island; or Boulder Island; or Geikie Rock; or Lone Island; or the... islands) of the easternmost point of Russell Island; or Graves Rocks (on the outer coast); or Cormorant... and Preserve Vessel Operating Restrictions § 13.1178 Closed waters, islands and other areas. The...

Geology Structure Identification Using Pre-Stack Depth Migration (PSDM Method of Tomography Result in North West Java Basin

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Sudra Irawan

2017-06-01

Full Text Available North West Java Basin is a tertiary sedimentary basin which is located in the right of the western part of the Java island. North West Java Basin is geodynamic where currently located at the rear position of the path of the volcanic arc of Java that is the result of the India-Australia plate subduction to the south towards the Eurasian plate (Explanation of Sunda in the north. Geology structure observation is difficult to be conducted at Quaternary volcanicfield due to the classical problem at tropical region. In the study interpretation of fault structures can be done on a cross-section of Pre-Stack Depth Migration (PSDM used prayer namely Hardware Key Device, ie Central Processing Unit: RedHat Enterprise Linux AS 5.0, prayer Monitor 24-inch pieces, Server: SGI altix 450/SuSe Linux Enterprise Server 9.0, 32 GB, 32 X 2,6 GHz Procesor, network: Gigabyte 1 Gb/s, and the software used is paradigm, product: Seismic Processing and Imaging. The third fault obtained in this study in accordance with the geological information derived from previous research conducted by geologists. The second general direction is northwest-southeast direction represented by Baribis fault, fault-fault in the Valley Cimandiri and Gunung Walat. This direction is often known as the directions Meratus (Meratus Trend. Meratus directions interpreted as directions that follow the pattern of continuous arc Cretaceous age to Meratus in Kalimantan.

Functional and phylogenetic structure of island bird communities.

Science.gov (United States)

Si, Xingfeng; Cadotte, Marc W; Zeng, Di; Baselga, Andrés; Zhao, Yuhao; Li, Jiaqi; Wu, Yiru; Wang, Siyu; Ding, Ping

2017-05-01

Biodiversity change in anthropogenically transformed habitats is often nonrandom, yet the nature and importance of the different mechanisms shaping community structure are unclear. Here, we extend the classic Theory of Island Biogeography (TIB) to account for nonrandom processes by incorporating species traits and phylogenetic relationships into a study of faunal relaxation following habitat loss and fragmentation. Two possible mechanisms can create nonrandom community patterns on fragment islands. First, small and isolated islands might consist of similar or closely related species because they are environmentally homogeneous or select for certain shared traits, such as dispersal ability. Alternatively, communities on small islands might contain more dissimilar or distantly related species than on large islands because limited space and resource availability result in greater competitive exclusion among species with high niche overlap. Breeding birds were surveyed on 36 islands and two mainland sites annually from 2010 to 2014 in the Thousand Island Lake region, China. We assessed community structure of breeding birds on these subtropical land-bridge islands by integrating species' trait and evolutionary distances. We additionally analysed habitat heterogeneity and variance in size ratios to distinguish biotic and abiotic processes of community assembly. Results showed that functional-phylogenetic diversity increased with island area, and decreased with isolation. Bird communities on the mainland were more diverse and generally less clustered than island bird communities and not different than randomly assembled communities. Bird communities on islands tend to be functionally similar and phylogenetically clustered, especially on small and isolated islands. The nonrandom decline in species diversity and change in bird community structure with island area and isolation, along with the relatively homogeneous habitats on small islands, support the environmental

STRATIGRAPHIC EVOLUTION, PALEOENVIRONMENTS AND HYDROCARBON POTENTIALS OF THE BENUE/DAHOMEY BASINS, NIGERIAN AND POTIGUAR/CEARA BASINS, NE BRAZIL

International Nuclear Information System (INIS)

Akande, S.O; Adekeye, O.A.; Oj, O.J; Erdtmann, B.D.; Koutsokous, E.I.

2004-01-01

The stratigraphy, facies relationship and paleoenvironment of selected West African and the Brazillian rift basins permit the recognition of at least two major petroleum systems apart from the prolific Niger Delta petroleum system. The Lower Cretaceous fluivio-lacustrine petroleum system and Upper Cretaceous to Lower Tertiary, marine dominated petroleum system. Our combined studies of the stratigraphic, structural framework, paleoenvironment and time-space relationships of the petroleum systems in the Benue/Dahomey and the Potiguar/Ceara basins indicated that rifting and subsequent drifting during the opening of the South Atlantic controlled subsidence, sediment deposition and facies associations in individual basins. Whereas in the Potiguar/Ceara basins, the best developed source rocks are within the Neomacin-Aptian fluvio- lacustrine sequence of the Pendencia and Alagamar Formations which generated reserved hydrocarbon in the Acu Formation, empirical evidence for this petroleum system in the contiguous Benue/Dahomey basins are only based on the geochemical characteristics of the lower parts of the Bima Formation and the Abeokuta Group. In contrast, the Upper Cretaceous-Lower Tertiary marine petroleum system, which is constrained by poor development of reservoirs in the Potiguar/Ceara basin is productive in the Benue/Dahomey basins where source rocks, reservoir and sealing facies occur at this interval. Considering the recent hydrocarbon discoveries of the East Niger basin, the Doba (southern Chad), the Muglad basin (southern Sudan) sourced from the fluvio-lacustrine rift sequences, we suggest that this petroleum system needs more detailed exploration and has some potentials in the Benue/Dahomey frontier basins

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume II. Palo Duro basin

International Nuclear Information System (INIS)

1982-09-01

This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and high variable precipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

Mesostructural observations along the Western coast of Bel'kovsky Island: preliminary results (North-Eastern Laptev Sea region, Russian Arctic)

Science.gov (United States)

Verzhbitsky, V. E.

2003-04-01

This study is based on the field works carried out by the Institute of the Lithosphere of Marginal Seas RAS in the central part of the Bel'kovsky island during 2002 August-September. In the tectonic sense the Bel'kovsky island is located in the eastern part of the Late Cretaceous (?) - Cenozoic Laptev Sea rift system and also is a part of extended Bel’kov horst, dividing Bel’kov Svyatoi Nos (in the east) and Anisin (in the west) rifts (e.g. Drachev et al, 1998). Mesostructural investigations included statistical measurments of kinematic indicators (cleavage planes, extensional veins, slickensides, axes of folds and bedding plains) in Devonian and Carboniferous sedimentary formations and also slickensides in diabase magmatic complex (presumably of Late Paleozoic age). It is supposed, that this studies will allow to characterize the stages of regional tectonic processes: synsedimentary (slump) folds formation (1), NE-SW compression (2), which corresponds to the general (NW-SE trending) structural pattern of the island, E-W compression (3), expressed in N-S trending subvertical cleavage and associated strike-slips and thrust faults, NW-SE (4) and ENE-WSW - NE-SW (5) extension, expressed in strike-slip faults with different strike-slip component, and also, probably to specify the character of the recent tectonic processes near to the area of conjunction between the Eurasian and American plates. It is likely, that synsedimentary (slump) folds, identified in the Carboniferous clastic formation marks the paleoslope setting of New Siberian Islands Chukotka platform (block). Presumably, second of the determined stages corresponds to closing of the South Anyui Lyakhov paleooceanic basin in Neocomian; the last stage, expressed in wide-developed submeridional normal faults with sinistral strike-slip component along the western coast of the island, reflects the modern regional stress-field in area of conjunction between the Eurasian and American plates (e.g. Avetisov, 1999

Deer Island Aquatic Ecosystem Restoration Project

Science.gov (United States)

2015-07-01

across the U.S. Army Corps of Engineers (USACE) requires that a broad base of EWN understanding and support be built . The Deer Island Aquatic...USACE) requires that a broad base of EWN understanding and support be built . The Deer Island Aquatic Ecosystem Restoration Project (Deer Island AERP...Mississippi Wetlands Restoration Projects). The project received additional funding through several public laws in response to hurricane damages

Sedimentary Fatty Alcohols in Kapas Island, Terengganu

International Nuclear Information System (INIS)

Noor Farahin Amiruddin; Mohamad Iznul Muazim Mohamad Zabidi; Nurul Fathihah Mt Nanyan; Masni Mohd Ali; Masni Mohd Ali

2015-01-01

A geochemical study was carried out to identify the composition and sources of fatty alcohols in Kapas Island, Terengganu, Malaysia. Fatty alcohols in surface sediments were extracted and analyzed using Gas Chromatography - Mass Spectrometry (GC-MS). A total of 23 fatty alcohol compounds were identified in the Kapas Island sediment. Total concentrations of fatty alcohols ranged from 0.53 to 21.31 ng/ g dry weight and the highest total concentration was found at S2, which is probably due to its location profile that is located north of Kapas Island which is close to several small islands. The short chain/ long chain fatty alcohol ratio and alcohol source index (ASI) were used together to identify the dominant input in Kapas Island. Kapas Island sediments contained a mixture of organic sources, of which terrestrial sources were indicated to be the most abundant sources in these marine sediments. (author)

Assessing qualitative long-term volcanic hazards at Lanzarote Island (Canary Islands

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L. Becerril

2017-07-01

Full Text Available Conducting long-term hazard assessment in active volcanic areas is of primary importance for land-use planning and defining emergency plans able to be applied in case of a crisis. A definition of scenario hazard maps helps to mitigate the consequences of future eruptions by anticipating the events that may occur. Lanzarote is an active volcanic island that has hosted the largest (>  1.5 km3 DRE and longest (6 years eruption, the Timanfaya eruption (1730–1736, on the Canary Islands in historical times (last 600 years. This eruption brought severe economic losses and forced local people to migrate. In spite of all these facts, no comprehensive hazard assessment or hazard maps have been developed for the island. In this work, we present an integrated long-term volcanic hazard evaluation using a systematic methodology that includes spatial analysis and simulations of the most probable eruptive scenarios.

Hydrologic Sub-basins of Greenland

Data.gov (United States)

National Aeronautics and Space Administration — The Hydrologic Sub-basins of Greenland data set contains Geographic Information System (GIS) polygon shapefiles that include 293 hydrologic sub-basins of the...

Fuelwood production in Prince Edward Island

International Nuclear Information System (INIS)

McCallum, B.

1992-01-01

The most recent Prince Edward Island Fuelwood Survey occurred in 1990-91. Consumption of fuelwood rose again to 49% of Prince Edward Island's 43,170 households. Total residential fuelwood consumption was estimated to be 242,000 m 3 . The fuelwood industry makes an important contribution to the economy of Prince Edward Island. In the 1990-91 heating season, fuelwood valued at USD 9 million displaced approximately 43 million litres of domestic heating oil valued at USD 16.4 million. In addition, it is estimated that 70 cents of every dollar spent on fuelwood remains in the province and contributes spin-off benefits, whereas 90 cents of every dollar spent on heating oil is lost to the economy of Prince Edward Island. The percentage of people cutting their own fuelwood decreased from 52 in 1984-85 to only 23.4 in 1990-91. The governments of Canada and Prince Edward Island have implemented a series of Forest Resource Development Agreements (FRDAs) starting in 1983. The current 1988-1993 FRDA provides USD 24 million for research and incentives for reforestation and management of Prince Edward Island woodlots. It is expected that 3,800 Prince Edward Island woodlot owners will be participating in a woodlot management program by 1993. Silviculture treatments of hardwood stands include thinning, stand conversion (removal of lowgrade softwoods such as balsam fir in mainly hardwood stands), and shelterwood (strip) cutting, particularly in marginal stands. (9 refs.)

Petroleum geology of the Palo Duro Basin, Texas Panhandle

International Nuclear Information System (INIS)

Rose, P.R.

1986-03-01

The Palo Duro Basin, Permian Basin, Texas is an asymmetric, relatively shallow, intracratonic basin in the southern Texas Panhandle filled mostly by Mississippian, Pennsylvanian, and Permian sedimentary rocks. Although deeper and prolific prolific petroleum-producing basins adjoin it on the north (Anadarko Basin), south (Midland Basin), and east (Hardeman Basin), the Palo Duro Basin has produced remarkably small amounts of oil and gas to date. This is all the more noteworthy because the sedimentary sequence and rock types of the basin are similar to those of the adjacent basins. Analyses of the stratigraphic succession and structural configuration of the Palo Duro Basin suggest that adequate reservoir rocks, top-seals, and geologic structures are present. Most of the structures formed early enough to have trapped hydrocarbons if they were migrating in the rock column. Although additional work is under way to properly address the question of the petroleum source rocks, generation, and migration, the general absence of production in the basin may relate to an overall deficiency in hydrocarbon generation within the basin. Geologic information in this report will form part of the basis for further analysis and conclusions on hydrocarbon potential in the Palo Duro Basin

A Novel Unscheduled Islanding Detection Method for Microgrid

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Li Hui

2018-01-01

Full Text Available Microgrid with its intelligent and flexible control characteristics conform to the trend of sustainable development of electricity, and when the microgrid in the unplanned island state, the successful detection of the island is a prerequisite, energy storage inverter as the key equipment in the microgrid system, island protection is one of the necessary functions. In this paper, an improved islanding detection method based on active frequency drift and q-axis reactive power perturbation is proposed. The method has the advantages of faster detection speed and minor influence on power quality, which makes the energy storage inverter with better output power quality when it works on grid-connected state, and can be detected the islanding state quickly from grid-connected mode to islanded mode. Finally, the validity and superiority of the improved island detection method are verified by simulation experiments.

Quality of surface waters in the lower Columbia River Basin

Science.gov (United States)

Santos, John F.

1965-01-01

chemical composition of the streams. The maximum dissolved-solids concentration and hardness of water observed in major irrigation areas were 507 and 262 parts per million, respectively, for the. Walla Walla River near Touchet, Wash. In terms of the U.S. Salinity Laboratory Staff classification (1954, p. 80), water in most streams in the basin has low salinity and sodium hazards and is suitable for irrigation. A salt-balance problem does exist in the Hermiston-Stanfield, Oreg., area of the Umatilla River basin, and because of poor drainage, improper irrigation practices could cause salt-balance problems in the Willamette River Valley, Oreg., in which irrigation is rapidly increasing. Pollution by sewage disposal has reached undesirable levels in the Walla Walla River, in the Willamette River from Eugene to Portland, Oreg., and in the Columbia River from Portland to Puget Island. In the lower reaches of the Willamette River, the pollution load from sewage and industrial-waste disposal at times depletes the dissolved oxygen in the water to concentrations below what is considered necessary for aquatic life. Water in most of the tributaries to the lower Columbia River is of excellent quality and after some treatment could be used for industrial and municipal supplies. The principal treatment required would be disinfection and turbidity removal.

Effects of insularity on digestion: living on islands induces shifts in physiological and morphological traits in island reptiles

Science.gov (United States)

Sagonas, Kostas; Pafilis, Panayiotis; Valakos, Efstratios D.

2015-10-01

Living on islands entails numerous challenges for animals, among which resource scarcity stands out. In order to survive, animals have to optimize energy acquisition. We examined the impact of insularity on digestion comparing a series of physiological and morphological traits of adult males between insular and mainland populations of the Balkan green lizard. Island lizards had longer gastrointestinal tracts and gut passage times and higher digestive efficiencies. The dissection of the hindgut revealed an unexpected finding, the presence of cecal valves that were more frequent in island lizards. Thanks to all above islanders retain food for longer periods and thus maximize energy income and increase the amount of the extracted nutrients. That way, they secure energy income from the limited, in time and quantity, food resources of the islands.

Evolution of the Rembrandt impact basin on Mercury.

Science.gov (United States)

Watters, Thomas R; Head, James W; Solomon, Sean C; Robinson, Mark S; Chapman, Clark R; Denevi, Brett W; Fassett, Caleb I; Murchie, Scott L; Strom, Robert G

2009-05-01

MESSENGER's second Mercury flyby revealed a ~715-kilometer-diameter impact basin, the second-largest well-preserved basin-scale impact structure known on the planet. The Rembrandt basin is comparable in age to the Caloris basin, is partially flooded by volcanic plains, and displays a unique wheel-and-spoke-like pattern of basin-radial and basin-concentric wrinkle ridges and graben. Stratigraphic relations indicate a multistaged infilling and deformational history involving successive or overlapping phases of contractional and extensional deformation. The youngest deformation of the basin involved the formation of a approximately 1000-kilometer-long lobate scarp, a product of the global cooling and contraction of Mercury.

Miocene block uplift and basin formation in the Patagonian foreland: The Gastre Basin, Argentina

Science.gov (United States)

Bilmes, A.; D'Elia, L.; Franzese, J. R.; Veiga, G. D.; Hernández, M.

2013-08-01

The intraplate fault-block mountains and intermontane deposits of the Gastre Basin, which are recorded more than 550 km east of the Andean trench in central Patagonia, Argentina, are analyzed. The Gastre Basin is one of the largest Patagonian intermontane basins, limited by uplifted blocks strongly oblique to the Andean chain. It was originated by reverse faulting and inversion of pre-existing normal faults associated with a Mesozoic rift basin and defined by older crustal heterogeneities. The deformational event occurred during the middle Miocene, related to a short contractional episode (16.1-14.86 Ma), probably in response to an eastward migration of the Andean fold and thrust belt. During Pliocene to Quaternary times, neither younger fault-block uplifts nor reconfigurations of the basin occurred. Similarities between the study area and other parts of the Patagonian foreland - such as the presence of Miocene reverse or inversion tectonics, as well as the accommodation of the Miocene sedimentary successions - suggest that the Gastre Basin is part of a major late early to middle Miocene broken foreland system (i.e. the Patagonian broken foreland) that exhumed discrete fault-block mountains and generated contemporary basins along more than 950 km parallel to the Andean trench (i.e. between 40°00' and 48°00' south latitude). Based on recent studies on the southern Andean Margin, this continental-scale contractional episode may be the result of a flat-slab subduction segment. Nevertheless, such a hypothesis is very difficult to support when analyzing such a large flat subduction segment along the entire Patagonian trench. This suggests the need to consider alternative flat-slab trigger mechanisms or other factors in the generation of broken foreland systems.

MARINE BOTTOM COMMUNITIES OF BLOCK ISLAND WATERS

Science.gov (United States)

The sea has long been an integral part of Block Island's natural history, beginning when the rising sea surrounded the high spot on a Pleistocene terminal moraine that became Block Island. The southern New England continental shelf, which lies around Block Island, and the Great S...

Three Mile Island revisited

International Nuclear Information System (INIS)

MacLeod, G.K.

1986-01-01

The accident at Three Mile Island proved that the Pennsylvania Department of Health lacked the tools to deal with the serious health consequences that occurred during and after this emergency. Despite the relative safety of nuclear power generation, we must be better prepared for the health and medical consequences of serous radiation emergencies. The author reviews the Three Mile Island accident through the eyes of newspaper reporters

Postglacial Records of Southern Hemisphere Climate and Oceanographic Change From the New Zealand Subantarctic Auckland Islands

Science.gov (United States)

Moy, C. M.; Gilmer, G.; Nichols, J. E.; Browne, I. M.; Curtin, L.; Vandergoes, M.; Aebig, C.; Wilson, G. S.

2017-12-01

The strength and latitudinal position of the Southern Hemisphere westerly winds (SHWW) play a fundamental role in influencing mid-latitude climate and CO2 exchange between the Southern Ocean and the atmosphere along seasonal to glaicial-interglacial timescales. Despite their importance, our understanding of past SHWW change is limited by the small number of paleoclimate records from the modern wind maximum, which are often not in agreement. The New Zealand subantarctic Auckland Islands are located within the core of the modern wind belt (50°S), a key latitude where ocean-atmospheric linkages between the Antarctic and mid-latitudes are strong. In contrast to other subantarctic islands on the Campbell Plateau, the Auckland Islands have multiple protected fjord sub-basins, deep lakes, and peatlands that are advantageous for the development of high-resolution paleoclimate records. We will present ongoing work towards the establishment of multi-proxy and multi-site reconstructions of past SHWW variability from the Auckland Islands. Modern process and paleoclimate studies suggest that in lacustrine and fjord settings, the degree of water column mixing, the stable isotopic composition of n-alkanes and benthic foraminifera, and the influx of terrestrial organic matter are good indicators of wind-induced mixing of the water column or precipitation-driven erosion within catchments. During the Late Glacial and early Holocene (15 to 9 ka), elevated long-chain n-alkane δD values from ombrotrophic peatlands and an increase in the concentration of redox-sensitive elements in fjord sediment cores, signal weakening of the SHWW that appears to be coincident with periods of rapid deglacial warming of West Antarctica. Since 5.5 ka, we interpret declining n-alkane δD values to indicate enhanced westerly flow. These interpretations are in broad agreement with terrestrial paleoclimate records developed from southern South America and argue for a symmetrical response of the SHWW during

5. Basin assessment and watershed analysis

Science.gov (United States)

Leslie M. Reid; Robert R. Ziemer

1994-01-01

Abstract - Basin assessment is an important component of the President's Forest Plan, yet it has received little attention. Basin assessments are intended both to guide watershed analyses by specifying types of issues and interactions that need to be understood, and, eventually, to integrate the results of watershed analyses occurring within a river basin....

A Basin Approach to a Hydrological Service Delivery System in the Amur River Basin

Directory of Open Access Journals (Sweden)

Sergei Borsch

2018-03-01

Full Text Available This paper presents the basin approach to the design, development, and operation of a hydrological forecasting and early warning system in a large transboundary river basin of high flood potential, where accurate, reliable, and timely available daily water-level and reservoir-inflow forecasts are essential for water-related economic and social activities (the Amur River basin case study. Key aspects of basin-scale system planning and implementation are considered, from choosing efficient forecast models and techniques, to developing and operating data-management procedures, to disseminating operational forecasts using web-GIS. The latter, making the relevant forecast data available in real time (via Internet, visual, and well interpretable, serves as a good tool for raising awareness of possible floods in a large region with transport and industrial hubs located alongside the Amur River (Khabarovsk, Komsomolsk-on-Amur.

From 3D to 4D seismic tomography at El Hierro Island (Canary Islands, Spain)

Science.gov (United States)

Garcia-Yeguas, A.; Koulakov, I.; Jakovlev, A.; Ibáñez, J. M.

2012-04-01

In this work we are going to show the advantages of a dynamic tomography 4D, versus a static image 3D related with a volcanic reactivation and eruption at El Hierro island (Canary Islands, Spain). In this process a high number of earthquakes before and during the eruptive processes have been registered. We are going to show a 3D image as an average of the velocity structure and then the characteristics and physical properties on the medium, including the presence or not of magma. This image will be complemented with its evolution along the time, observing its volcanic dynamic and its influence over the medium properties, including its power as an important element on early warnings protocols. After more than forty years of quiet at Canary Islands, since 1971 with Teneguía eruption at La Palma Island, and more than 200 years on El Hierro Island (The last eruption known at El Hierro took place in 1793, volcán de Lomo Negro), on 19th July on 2011 the Spanish seismic national network, administered by IGN (Instituto Geográfico Nacional), detected an increase of local seismic activity below El Hierro island (Canary Islands, Spain). Since this moment an intense swarm took place, with more than 11000 events, until 11th December, with magnitudes (MLg) from 0.2 to 4.4. In this period two eruptive processes have been declared in front of the South coast of El Hierro island, and they have not finished yet. This seismic swarm has allowed carrying out a 3D seismic tomography, using P and S waves traveltimes. It has showed a low velocity from the North to the South. On the other hand, we have performed a 4D seismic tomography, taking the events occurred at different intervals of time. We can observe the evolution of the negative anomaly along the time, from the North to the South, where has taken place La Restinga submarine eruption. 4D seismic tomography is an innovative and powerful tool able to show the evolution in time of a volcanic process.

Analysis of efficiency of pollution reduction measures in rural basin using MIKE Basin model. Case study: Olšava River Basin

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Kaiglová Jana

2014-03-01

Full Text Available This paper presents the results of testing the applicability of the MIKE Basin model for simulating the efficiency of scenarios for reducing water pollution. The model has been tested on the Olšava River Basin (520 km2 which is a typical rural region with a heterogeneous mix of pollution sources with variable topography and land use. The study proved that the model can be calibrated successfully using even the limited amount of data typically available in rural basins. The scenarios of pollution reduction were based on implementation and intensification of municipal wastewater treatment and conversion of arable land on fields under the risk of soil erosion to permanent grassland. The application of simulation results of these scenarios with proposed measures proved decreasing concentrations in downstream monitoring stations. Due to the practical applicability of proposed measures, these could lead to fulfilment of the water pollution limits required by the Czech and EU legislation. However, there are factors of uncertainty that are discussed that may delay or limit the effect of adopted measures in small rural basins.

Hypersonic drift-tearing magnetic islands in tokamak plasmas

International Nuclear Information System (INIS)

Fitzpatrick, R.; Waelbroeck, F. L.

2007-01-01

A two-fluid theory of long wavelength, hypersonic, drift-tearing magnetic islands in low-collisionality, low-β plasmas possessing relatively weak magnetic shear is developed. The model assumes both slab geometry and cold ions, and neglects electron temperature and equilibrium current gradient effects. The problem is solved in three asymptotically matched regions. The 'inner region' contains the island. However, the island emits electrostatic drift-acoustic waves that propagate into the surrounding 'intermediate region', where they are absorbed by the plasma. Since the waves carry momentum, the inner region exerts a net force on the intermediate region, and vice versa, giving rise to strong velocity shear in the region immediately surrounding the island. The intermediate region is matched to the surrounding 'outer region', in which ideal magnetohydrodynamic holds. Isolated hypersonic islands propagate with a velocity that lies between those of the unperturbed local ion and electron fluids, but is much closer to the latter. The ion polarization current is stabilizing, and increases with increasing island width. Finally, the hypersonic branch of isolated island solutions ceases to exist above a certain critical island width. Hypersonic islands whose widths exceed the critical width are hypothesized to bifurcate to the so-called 'sonic' solution branch

Quaternary Sedimentary Processes and Budgets in Orphan Basin, Southwestern Labrador Sea

Science.gov (United States)

Hiscott, Richard N.; Aksu, Ali E.

1996-03-01

The continental slope in Orphan Basin, northeast of Newfoundland, is underlain by several seaward-thinning debris-flow wedges alternating with acoustically stratified, regionally extensive, mainly hemipelagic sediments. δ 18O stratigraphy and volcanic ash layers in a 11.67-m core indicate that the uppermost debris-flow wedge formed during the last of several sea-level lowstands in isotopic stages 2-4. Similarly, seismic reflection correlation of dated levels at DSDP Site 111 with the Orphan Basin succession suggests that two deeper debris-flow wedges were deposited during oxygen isotopic stages 6 and 8. The oldest of the debris-flow deposits in at least three of the wedges formed well into the corresponding glacial cycle, after ice sheets had reached the edge of the continental shelf. Slower deposition by hemipelagic processes and ice rafting formed the acoustically stratified units, including Heinrich layers. The youngest three debris-flow wedges each have volumes of 1300-1650 km 3. Approximately two-thirds of this material is attributed to glacial erosion of Mesozoic and Tertiary strata beneath the Northeast Newfoundland Shelf. The remainder is believed to have been derived by glacial erosion of older bedrock that now forms the island of Newfoundland. The observed sediment volumes and the inferred basal and upper ages of the debris-flow wedges imply an average glacial denudation rate of about 0.13 mm/yr for this older bedrock, and an average of about 60 m of glacial bedrock erosion since oxygen isotope stage 22. This denudation rate is similar to estimates from the Barents Sea region off Norway.

California Basin Studies (CaBS)

International Nuclear Information System (INIS)

Gorsline, D.S.

1991-01-01

The California Continental Borderland's present configuration dates from about 4 to 5 X 10 6 years Before Present (B.P.) and is the most recent of several configurations of the southern California margin that have evolved after the North America Plate over-rode the East Pacific Rise about 30 X 10 6 years ago. The present morphology is a series of two to three northwest-southeast trending rows of depressions separated by banks and insular ridges. Two inner basins, Santa Monica and San Pedro, have been the site for the Department of Energy-funded California Basin Study (CaBS) Santa Monica and San Pedro Basins contain post-Miocene sediment thicknesses of about 2.5 and 1.5 km respectively. During the Holocene (past 10,000 years) about 10-12 m have accumulated. The sediment entered the basin by one or a combination of processes including particle infall (mainly as bioaggregates) from surface waters, from nepheloid plumes (surface, mid-depths and near-bottom), from turbidity currents, mass movements, and to a very minor degree direct precipitation. In Santa Monica Basin, during the last century, particle infall and nepheloid plume transport have been the most common processes. The former dominates in the central basin floor in water depths from 900 to 945 m. where a characteristic silt-clay with a typical mean diameter of about 0.006 mm, phi standard deviation

Floristic account of the marine benthic algae from Jarvis Island and Kingman Reef, Line Islands, Central Pacific

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Vroom, P.S.

2012-05-01

Full Text Available The marine benthic algae from Jarvis Island and Kingman Reef were identified from collections obtained from the Whippoorwill Expedition in 1924, the Itasca Expedition in 1935, the U.S. Coast Guard Cutter Taney in 1938, the Smithsonian Institution’s Pacific Ocean Biological Survey Program in 1964 and the U.S. National Oceanic and Atmospheric Administration’s Reef Assessment and Monitoring Program (RAMP in 2000, 2001, 2002, 2004 and 2006. A total of 124 species, representing 8 Cyanobacteria (blue-green algae, 82 Rhodophyta (red algae, 6 Heterokontophyta (brown algae and 28 Chlorophyta (green algae, are reported from both islands. Seventy-nine and 95 species of marine benthic algae are recorded from Jarvis Island and Kingman Reef, respectively. Of the 124 species, 77 species or 62% (4 blue-green algae, 57 red algae, 2 brown algae and 14 green algae have never before been reported from the 11 remote reefs, atolls and low islands comprising the Line Islands in the Central Pacific.

Small Island Visitor Attractions

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Haven Allahar

2015-03-01

Full Text Available This article proposes a process framework for developing and managing visitor attractions (VA in small island developing states with Trinidad and Tobago, a two-island state in the Caribbean, as the case study. An extensive literature review was conducted, supported by field observations, individual depth interviews, and small and large focus group meetings. The process framework identified four sets of processes: national policy formulation and legislation; inventory, classification, evaluation, and ranking of VA; general operations management involving project management activities; and site specific activities of development, operations, and maintenance. The value of the framework lies in the fact that no similar framework applicable to small islands was covered in the literature and validation was obtained from a panel of experts and a cross section of tourism stakeholders in Tobago.

Basalt stratigraphy - Pasco Basin

International Nuclear Information System (INIS)

Waters, A.C.; Myers, C.W.; Brown, D.J.; Ledgerwood, R.K.

1979-10-01

The geologic history of the Pasco Basin is sketched. Study of the stratigraphy of the area involved a number of techniques including major-element chemistry, paleomagnetic investigations, borehole logging, and other geophysical survey methods. Grande Ronde basalt accumulation in the Pasco Basin is described. An illustrative log response is shown. 1 figure

Bottom water circulation in Cascadia Basin

Science.gov (United States)

Hautala, Susan L.; Paul Johnson, H.; Hammond, Douglas E.

2009-10-01

A combination of beta spiral and minimum length inverse methods, along with a compilation of historical and recent high-resolution CTD data, are used to produce a quantitative estimate of the subthermocline circulation in Cascadia Basin. Flow in the North Pacific Deep Water, from 900-1900 m, is characterized by a basin-scale anticyclonic gyre. Below 2000 m, two water masses are present within the basin interior, distinguished by different potential temperature-salinity lines. These water masses, referred to as Cascadia Basin Bottom Water (CBBW) and Cascadia Basin Deep Water (CBDW), are separated by a transition zone at about 2400 m depth. Below the depth where it freely communicates with the broader North Pacific, Cascadia Basin is renewed by northward flow through deep gaps in the Blanco Fracture Zone that feeds the lower limb of a vertical circulation cell within the CBBW. Lower CBBW gradually warms and returns to the south at lighter density. Isopycnal layer renewal times, based on combined lateral and diapycnal advective fluxes, increase upwards from the bottom. The densest layer, existing in the southeast quadrant of the basin below ˜2850 m, has an advective flushing time of 0.6 years. The total volume flushing time for the entire CBBW is 2.4 years, corresponding to an average water parcel residence time of 4.7 years. Geothermal heating at the Cascadia Basin seafloor produces a characteristic bottom-intensified temperature anomaly and plays an important role in the conversion of cold bottom water to lighter density within the CBBW. Although covering only about 0.05% of the global seafloor, the combined effects of bottom heat flux and diapycnal mixing within Cascadia Basin provide about 2-3% of the total required global input to the upward branch of the global thermohaline circulation.

Predictable evolution toward flightlessness in volant island birds.

Science.gov (United States)

Wright, Natalie A; Steadman, David W; Witt, Christopher C

2016-04-26

Birds are prolific colonists of islands, where they readily evolve distinct forms. Identifying predictable, directional patterns of evolutionary change in island birds, however, has proved challenging. The "island rule" predicts that island species evolve toward intermediate sizes, but its general applicability to birds is questionable. However, convergent evolution has clearly occurred in the island bird lineages that have undergone transitions to secondary flightlessness, a process involving drastic reduction of the flight muscles and enlargement of the hindlimbs. Here, we investigated whether volant island bird populations tend to change shape in a way that converges subtly on the flightless form. We found that island bird species have evolved smaller flight muscles than their continental relatives. Furthermore, in 366 populations of Caribbean and Pacific birds, smaller flight muscles and longer legs evolved in response to increasing insularity and, strikingly, the scarcity of avian and mammalian predators. On smaller islands with fewer predators, birds exhibited shifts in investment from forelimbs to hindlimbs that were qualitatively similar to anatomical rearrangements observed in flightless birds. These findings suggest that island bird populations tend to evolve on a trajectory toward flightlessness, even if most remain volant. This pattern was consistent across nine families and four orders that vary in lifestyle, foraging behavior, flight style, and body size. These predictable shifts in avian morphology may reduce the physical capacity for escape via flight and diminish the potential for small-island taxa to diversify via dispersal.

Lithospheric-scale centrifuge models of pull-apart basins

Science.gov (United States)

Corti, Giacomo; Dooley, Tim P.

2015-11-01

We present here the results of the first lithospheric-scale centrifuge models of pull-apart basins. The experiments simulate relative displacement of two lithospheric blocks along two offset master faults, with the presence of a weak zone in the offset area localising deformation during strike-slip displacement. Reproducing the entire lithosphere-asthenosphere system provides boundary conditions that are more realistic than the horizontal detachment in traditional 1 g experiments and thus provide a better approximation of the dynamic evolution of natural pull-apart basins. Model results show that local extension in the pull-apart basins is accommodated through development of oblique-slip faulting at the basin margins and cross-basin faults obliquely cutting the rift depression. As observed in previous modelling studies, our centrifuge experiments suggest that the angle of offset between the master fault segments is one of the most important parameters controlling the architecture of pull-apart basins: the basins are lozenge shaped in the case of underlapping master faults, lazy-Z shaped in case of neutral offset and rhomboidal shaped for overlapping master faults. Model cross sections show significant along-strike variations in basin morphology, with transition from narrow V- and U-shaped grabens to a more symmetric, boxlike geometry passing from the basin terminations to the basin centre; a flip in the dominance of the sidewall faults from one end of the basin to the other is observed in all models. These geometries are also typical of 1 g models and characterise several pull-apart basins worldwide. Our models show that the complex faulting in the upper brittle layer corresponds at depth to strong thinning of the ductile layer in the weak zone; a rise of the base of the lithosphere occurs beneath the basin, and maximum lithospheric thinning roughly corresponds to the areas of maximum surface subsidence (i.e., the basin depocentre).

The role of Mesozoic sedimentary basin tapers on the formation of Cenozoic crustal shortening structures and foredeep in the western Sichuan Basin, China

Science.gov (United States)

Wang, M.

2017-12-01

The foreland basin records important clues of tectonic and sedimentary process of mountain-building, thus to explore its dynamic mechanism on the formation is an important issue of the mountain-basin interaction. The Longmen Shan fold-and-thrust belt and its adjacent Sichuan basin located in the eastern margin of Tibetan Plateau, are one of the most-concerned regions of studying modern mountain-building and seismic process, and are also a natural laboratory of studying the dynamics of the formation and development of foreland basin. However, it still need further explore on the mechanics of the development of the Cenozoic foreland basin and thrust-belts in the western Sichuan Basin. The Longmen Shan thrust belt has experienced multi-stages of tectonics evolution, foreland basin formation and topography growth since Late Triassic, and whether the early formed basin architecture and large Mesozoic sedimentary basin taper can influence the formation and development of the Cenozoic foreland basin and thrust belts? To solve these issues, this project aim to focus on the Cenozoic foreland basin and internal crustal shortening structures in the western Sichuan basin, on the basis of growth critical wedge taper theory. We will reconstruct the shape of multi-phases of sedimentary basin tapers, the temporal-spatial distribution of crustal shortening and thrusting sequences, and analyze the control mechanism of Mesozoic sedimentary basin taper on the formation of Cenozoic foreland basins, and final explore the interaction between the tectonics geomorphology, stress field and dynamic propagation of foreland basin.

Numerical modeling of atoll island hydrogeology.

Science.gov (United States)

Bailey, R T; Jenson, J W; Olsen, A E

2009-01-01

We implemented Ayers and Vachers' (1986) inclusive conceptual model for atoll island aquifers in a comprehensive numerical modeling study to evaluate the response of the fresh water lens to selected controlling climatic and geologic variables. Climatic factors include both constant and time-varying recharge rates, with particular attention paid to the effects of El Niño and the associated drought it brings to the western Pacific. Geologic factors include island width; hydraulic conductivity of the uppermost Holocene-age aquifer, which contains the fresh water lens; the depth to the contact with the underlying, and much more conductive, Pleistocene karst aquifer, which transmits tidal signals to the base of the lens; and the presence or absence of a semiconfining reef flat plate on the ocean side. Sensitivity analyses of steady-steady simulations show that lens thickness is most strongly sensitive to the depth to the Holocene-Pleistocene contact and to the hydraulic conductivity of the Holocene aquifer, respectively. Comparisons between modeling results and published observations of atoll island lens thicknesses suggest a hydraulic conductivity of approximately 50 m/d for leeward islands and approximately 400 m/d for windward islands. Results of transient simulations show that lens thickness fluctuations during average seasonal conditions and El Niño events are quite sensitive to island width, recharge rate, and hydraulic conductivity of the Holocene aquifer. In general, the depletion of the lens during drought conditions is most drastic for small, windward islands. Simulation results suggest that recovery from a 6-month drought requires about 1.5 years.

Climate Change in the Pacific Islands

Science.gov (United States)

Hamnett, Michael P.

Climate change have been a major concern among Pacific Islanders since the late 1990s. During that period, Time Magazine featured a cover story that read: Say Goodbye to the Marshall Islands, Kiribati, and Tuvalu from sea level rise. Since that time, the South Pacific Regional Environment Programme, UN and government agencies and academic researchers have been assessing the impacts of long-term climate change and seasonal to inter-annual climate variability on the Pacific Islands. The consensus is that long-term climate change will result in more extreme weather and tidal events including droughts, floods, tropical cyclones, coastal erosion, and salt water inundation. Extreme weather events already occur in the Pacific Islands and they are patterned. El Niño Southern Oscillation (ENSO) events impact rainfall, tropical cyclone and tidal patterns. In 2000, the first National Assessment of the Consequences of Climate Variability and Change concluded that long-term climate change will result in more El Niño events or a more El Niño like climate every year. The bad news is that will mean more natural disasters. The good news is that El Niño events can be predicted and people can prepare for them. The reallly bad news is that some Pacific Islands are already becoming uninhabitable because of erosion of land or the loss of fresh water from droughts and salt water intrusion. Many of the most vulnerable countries already overseas populations in New Zealand, the US, or larger Pacific Island countries. For some Pacific Islander abandoning their home countries will be their only option.

On the significance of ELF basins

Indian Academy of Sciences (India)

Unknown

to complement to chemical intuition (see, e.g., refs. 2, 3). In a mathematically more rigorous way, such regions, ELF basins,4 were defined following the spirit of Bader's Atoms in Molecules (AIM). All points in space which lead to the a given maximum of ELF, by following the gradient of ELF, belong to the same basin. Basins ...

Professional operation and management of nuclear island installation

International Nuclear Information System (INIS)

Ma Limin

2011-01-01

As an important part of nuclear power plant construction, nuclear island installation mainly involves main equipment installation, pipeline installation, associated procedure examination and other important tasks. However, due to the nuclear island installation management changing from single project to multi-projects, the problems such as professional management of nuclear island installation and the lack of technical staff become more and more prominent and become one of the key restricts to the work of nuclear island installation. Based on analysis of the single project, single-base nuclear island installation management and practice, combined with the current situation that multi-project and multi-base construction of nuclear power are carrying out at the same time, this paper proposes a new management model of nuclear island installation. (author)

Phytoseiid mites of the Canary Islands (Acari, Phytoseiidae. II. Tenerife and La Gomera Islands

Directory of Open Access Journals (Sweden)

Ferragut, F.

2007-12-01

Full Text Available Phytoseiid mites (Acari, Phytoseiidae inhabiting plants in natural ecosystems from Tenerife and La Gomera islands (Canary Islands have been studied. Surveys were conducted from 1997 to 2002. Eleven species were collected, one of them being reported for the first time from the Canary Islands and six of them reported for the first time from Tenerife and La Gomera islands. Euseius machadoi n. sp. collected from woody plants in the Canarian laurisilva is proposed as a new species.

En muestreos realizados desde 1997 hasta 2002 se ha estudiado la fauna de ácaros fitoseidos (Acari, Phytoseiidae asociada a plantas de ecosistemas naturales de las islas de Tenerife y La Gomera (Islas Canarias. Se han recolectado un total de 11 especies, siendo una de ellas citada por vez primera en las islas Canarias y seis de ellas citadas por primera vez en las islas de Tenerife y La Gomera. Euseius machadoi n. sp., recolectado en plantas leñosas de la laurisilva canaria, se propone como una nueva especie.

Transient electromagnetic study of basin fill sediments in the Upper San Pedro Basin, Mexico

Science.gov (United States)

Bultman, M.W.; Gray, F.

2011-01-01

The Upper San Pedro River Basin in Mexico and the United States is an important riparian corridor that is coming under increasing pressure from growing populations and the associated increase in groundwater withdrawal. Several studies have produced three-dimensional maps of the basin fill sediments in the US portion of the basin but little work has been done in the Mexican portion of the basin. Here, the results of a ground-based transient electromagnetic (TEM) survey in the Upper San Pedro Basin, Mexico are presented. These basin fill sediments are characterized by a 10-40 m deep unsaturated surficial zone which is composed primarily of sands and gravels. In the central portion of the basin this unsaturated zone is usually underlain by a shallow clay layer 20-50 m thick. Beneath this may be more clay, as is usually the case near the San Pedro River, or interbedded sand, silt, and clay to a depth of 200-250 m. As you move away from the river, the upper clay layer disappears and the amount of sand in the sediments increases. At 1-2 km away from the river, sands can occupy up to 50% of the upper 200-250 m of the sediment fill. Below this, clays are always present except where bedrock highs are observed. This lower clay layer begins at a depth of about 200 m in the central portion of the basin (250 m or more at distances greater than 1-2 km from the river) and extends to the bottom of most profiles to depths of 400 m. While the depth of the top of this lower clay layer is probably accurate, its thickness observed in the models may be overestimated due to the relatively low magnetic moment of the TEM system used in this study. The inversion routine used for interpretation is based on a one-dimensional geologic model. This is a layer based model that is isotropic in both the x and y directions. Several survey soundings did not meet this requirement which invalidates the inversion process and the resulting interpretation at these locations. The results from these

BasinVis 1.0: A MATLAB®-based program for sedimentary basin subsidence analysis and visualization

Science.gov (United States)

Lee, Eun Young; Novotny, Johannes; Wagreich, Michael

2016-06-01

Stratigraphic and structural mapping is important to understand the internal structure of sedimentary basins. Subsidence analysis provides significant insights for basin evolution. We designed a new software package to process and visualize stratigraphic setting and subsidence evolution of sedimentary basins from well data. BasinVis 1.0 is implemented in MATLAB®, a multi-paradigm numerical computing environment, and employs two numerical methods: interpolation and subsidence analysis. Five different interpolation methods (linear, natural, cubic spline, Kriging, and thin-plate spline) are provided in this program for surface modeling. The subsidence analysis consists of decompaction and backstripping techniques. BasinVis 1.0 incorporates five main processing steps; (1) setup (study area and stratigraphic units), (2) loading well data, (3) stratigraphic setting visualization, (4) subsidence parameter input, and (5) subsidence analysis and visualization. For in-depth analysis, our software provides cross-section and dip-slip fault backstripping tools. The graphical user interface guides users through the workflow and provides tools to analyze and export the results. Interpolation and subsidence results are cached to minimize redundant computations and improve the interactivity of the program. All 2D and 3D visualizations are created by using MATLAB plotting functions, which enables users to fine-tune the results using the full range of available plot options in MATLAB. We demonstrate all functions in a case study of Miocene sediment in the central Vienna Basin.

BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

Energy Technology Data Exchange (ETDEWEB)

Ernest A. Mancini; Donald A. Goddard; Ronald K. Zimmerman

2005-05-10

The principal research effort for Year 2 of the project has been data compilation and the determination of the burial and thermal maturation histories of the North Louisiana Salt Basin and basin modeling and petroleum system identification. In the first nine (9) months of Year 2, the research focus was on the determination of the burial and thermal maturation histories, and during the remainder of the year the emphasis has basin modeling and petroleum system identification. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, regional cross sections have been prepared, structure and isopach maps have been constructed, and burial history, thermal maturation history and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and related profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs are mainly Upper Jurassic and Lower Cretaceous fluvial-deltaic sandstone facies and Lower Cretaceous and Upper Cretaceous shoreline, marine bar and shallow shelf sandstone facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary

Mass coral bleaching due to unprecedented marine heatwave in Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands).

Science.gov (United States)

Couch, Courtney S; Burns, John H R; Liu, Gang; Steward, Kanoelani; Gutlay, Tiffany Nicole; Kenyon, Jean; Eakin, C Mark; Kosaki, Randall K

2017-01-01

2014 marked the sixth and most widespread mass bleaching event reported in the Northwestern Hawaiian Islands, home to the Papahānaumokuākea Marine National Monument (PMNM), the world's second largest marine reserve. This event was associated with an unusual basin-scale warming in the North Pacific Ocean, with an unprecedented peak intensity of around 20°C-weeks of cumulative heat stress at Lisianksi Island. In situ bleaching surveys and satellite data were used to evaluate the relative importance of potential drivers of bleaching patterns in 2014, assess the subsequent morality and its effects on coral communities and 3D complexity, test for signs of regional acclimation, and investigate long-term change in heat stress in PMNM. Surveys conducted at four island/atoll (French Frigate Shoals, Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll) showed that in 2014, percent bleaching varied considerably between islands/atolls and habitats (back reef/fore reef and depth), and was up to 91% in shallow habitats at Lisianski. The percent bleaching during the 2014 event was best explained by a combination of duration of heat stress measured by Coral Reef Watch's satellite Degree Heating Week, relative community susceptibility (bleaching susceptibility score of each taxon * the taxon's abundance relative to the total number of colonies), depth and region. Mean coral cover at permanent Lisianski monitoring sites decreased by 68% due to severe losses of Montipora dilatata complex, resulting in rapid reductions in habitat complexity. Spatial distribution of the 2014 bleaching was significantly different from the 2002 and 2004 bleaching events likely due to a combination of differences in heat stress and local acclimatization. Historical satellite data demonstrated heat stress in 2014 was unlike any previous event and that the exposure of corals to the bleaching-level heat stress has increased significantly in the northern PMNM since 1982, highlighting the increasing