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Sample records for pole-aitken basin ejecta

  1. Sample Return Mission to the South Pole Aitken Basin

    Science.gov (United States)

    Duke, M. B.; Clark, B. C.; Gamber, T.; Lucey, P. G.; Ryder, G.; Taylor, G. J.

    1999-01-01

    The South Pole Aitken Basin (SPA) is the largest and oldest observed feature on the Moon. Compositional and topographic data from Galileo, Clementine, and Lunar Prospector have demonstrated that SPA represents a distinctive major lunar terrane, which has not been sampled either by sample return missions (Apollo, Luna) or by lunar meteorites. The floor of SPA is characterized by mafic compositions enriched in Fe, Ti, and Th in comparison to its surroundings. This composition may represent melt rocks from the SPA event, which would be mixtures of the preexisting crust and mantle rocks. However, the Fe content is higher than expected, and the large Apollo basin, within SPA, exposes deeper material with lower iron content. Some of the Fe enrichment may represent mare and cryptomare deposits. No model adequately accounts for all of the characteristics of the SPA and disagreements are fundamental. Is mantle material exposed or contained as fragments in melt rock and breccias? If impact melt is present, did the vast sheet differentiate? Was the initial mantle and crust compositionally different from other regions of the Moon? Was the impact event somehow peculiar, (e.g., a low-velocity impact)? The precise time of formation of the SPA is unknown, being limited only by the initial differentiation of the Moon and the age of the Imbrium event, believed to be 3.9 b.y. The questions raised by the SPA can be addressed only with detailed sample analysis. Analysis of the melt rocks, fragments in breccias, and basalts of SPA can address several highly significant problems for the Moon and the history of the solar system. The time of formation of SPA, based on analysis of melt rocks formed in the event. would put limits on the period of intense bombardment of the Moon, which has been inferred by some to include a "terminal cataclysm." If close to 3.9 Ga, the presumed age of the Imbrium Basin, the SPA date would confirm the lunar cataclysm. This episode, if it occurred, would have

  2. The Apollo peak-ring impact basin: Insights into the structure and evolution of the South Pole-Aitken basin

    Science.gov (United States)

    Potter, Ross W. K.; Head, James W.; Guo, Dijun; Liu, Jianzhong; Xiao, Long

    2018-05-01

    The 492 km-diameter Apollo impact basin post-dates, and is located at the inner edge of, the ∼2240 km-diameter South Pole-Aitken (SPA) basin, providing an opportunity to assess the SPA substructure and lateral heterogeneity. Gravity Recovery and Interior Laboratory gravity data suggest an average crustal thickness on the floor of SPA of ∼20 km and within the Apollo basin of ∼5 km, yet remote sensing data reveal no conclusive evidence for the presence of exposed mantle material. We use the iSALE shock physics code to model the formation of the Apollo basin and find that the observational data are best fit by the impact of a 40 km diameter body traveling at 15 km/s into 20-40 km thick crustal material. These results strongly suggest that the Apollo impact occurred on ejecta deposits and collapsed crustal material of the SPA basin and could help place constraints on the location, size and geometry of the SPA transient cavity. The peak ring in the interior of Apollo basin is plausibly interpreted to be composed of inwardly collapsed lower crustal material that experienced peak shock pressures in excess of 35 GPa, consistent with remote sensing observations that suggest shocked plagioclase. Proposed robotic and/or human missions to SPA and Apollo would present an excellent opportunity to test the predictions of this work and address many scientific questions about SPA basin evolution and structure.

  3. Magnetic Signature of the Lunar South Pole-Aitken Basin: Character, Origin, and Age

    Science.gov (United States)

    Purucker, Michael E.; Head, James W., III; Wilson, Lionel

    2012-01-01

    A new magnetic map of the Moon, based on Lunar Prospector (LP) magnetometer observations, sheds light on the origin of the South Pole-Aitken Basin (SPA), the largest and oldest of the recognized lunar basins. A set of WNW-trending linear to arcuate magnetic features, evident in both the radial and scalar observations, covers much of a 1000 km wide region centered on the NW portion of SPA. The source bodies are not at the surface because the magnetic features show no first-order correspondence to any surface topographic or structural feature. Patchy mare basalts of possible late Imbrianage are emplaced within SPA and are inferred to have been emplaced through dikes, directly from mantle sources. We infer that the magnetic features represent dike swarms that served as feeders for these mare basalts, as evident from the location of the Thomson/ Mare Ingenii, Van de Graaff, and Leeuwenhoek mare basalts on the two largest magnetic features in the region. Modeling suggests that the dike zone is between 25 and 50 km wide at the surface, and dike magnetization contrasts are in the range of 0.2 A/m. We theorize that the basaltic dikes were emplaced in the lunar crust when a long-lived dynamo was active. Based on pressure, temperature, and stress conditions prevalent in the lunar crust, dikes are expected to be a dominantly subsurface phenomenon, consistent with the observations reported here.

  4. Moonrise: Sampling the South Pole-Aitken Basin to Address Problems of Solar System Significance

    Science.gov (United States)

    Zeigler, R. A.; Jolliff, B. L.; Korotev, R. L.; Shearer, C. K.

    2016-01-01

    A mission to land in the giant South Pole-Aitken (SPA) Basin on the Moon's southern farside and return a sample to Earth for analysis is a high priority for Solar System Science. Such a sample would be used to determine the age of the SPA impact; the chronology of the basin, including the ages of basins and large impacts within SPA, with implications for early Solar System dynamics and the magmatic history of the Moon; the age and composition of volcanic rocks within SPA; the origin of the thorium signature of SPA with implications for the origin of exposed materials and thermal evolution of the Moon; and possibly the magnetization that forms a strong anomaly especially evident in the northern parts of the SPA basin. It is well known from studies of the Apollo regolith that rock fragments found in the regolith form a representative collection of many different rock types delivered to the site by the impact process (Fig. 1). Such samples are well documented to contain a broad suite of materials that reflect both the local major rock formations, as well as some exotic materials from far distant sources. Within the SPA basin, modeling of the impact ejection process indicates that regolith would be dominated by SPA substrate, formed at the time of the SPA basin-forming impact and for the most part moved around by subsequent impacts. Consistent with GRAIL data, the SPA impact likely formed a vast melt body tens of km thick that took perhaps several million years to cool, but that nonetheless represents barely an instant in geologic time that should be readily apparent through integrated geochronologic studies involving multiple chronometers. It is anticipated that a statistically significant number of age determinations would yield not only the age of SPA but also the age of several prominent nearby basins and large craters within SPA. This chronology would provide a contrast to the Imbrium-dominated chronology of the nearside Apollo samples and an independent test of

  5. Local Lunar Gravity Field Analysis over the South Pole-aitken Basin from SELENE Farside Tracking Data

    Science.gov (United States)

    Goossens, Sander Johannes; Ishihara, Yoshiaki; Matsumoto, Koji; Sasaki, Sho

    2012-01-01

    We present a method with which we determined the local lunar gravity field model over the South Pole-Aitken (SPA) basin on the farside of the Moon by estimating adjustments to a global lunar gravity field model using SELENE tracking data. Our adjustments are expressed in localized functions concentrated over the SPA region in a spherical cap with a radius of 45deg centered at (191.1 deg E, 53.2 deg S), and the resolution is equivalent to a 150th degree and order spherical harmonics expansion. The new solution over SPA was used in several applications of geophysical analysis. It shows an increased correlation with high-resolution lunar topography in the frequency band l = 40-70, and admittance values are slightly different and more leveled when compared to other, global gravity field models using the same data. The adjustments expressed in free-air anomalies and differences in Bouguer anomalies between the local solution and the a priori global solution correlate with topographic surface features. The Moho structure beneath the SPA basin is slightly modified in our solution, most notably at the southern rim of the Apollo basin and around the Zeeman crater

  6. Lunar Reconnaissance Orbiter Data Enable Science and Terrain Analysis of Potential Landing Sites in South Pole-Aitken Basin

    Science.gov (United States)

    Jolliff, B. L.

    2017-12-01

    Exploring the South Pole-Aitken basin (SPA), one of the key unsampled geologic terranes on the Moon, is a high priority for Solar System science. As the largest and oldest recognizable impact basin on the Moon, it anchors the heavy bombardment chronology. It is thus a key target for sample return to better understand the impact flux in the Solar System between formation of the Moon and 3.9 Ga when Imbrium, one of the last of the great lunar impact basins, formed. Exploration of SPA has implications for understanding early habitable environments on the terrestrial planets. Global mineralogical and compositional data exist from the Clementine UV-VIS camera, the Lunar Prospector Gamma Ray Spectrometer, the Moon Mineralogy Mapper (M3) on Chandrayaan-1, the Chang'E-1 Imaging Interferometer, the spectral suite on SELENE, and the Lunar Reconnaissance Orbiter Cameras (LROC) Wide Angle Camera (WAC) and Diviner thermal radiometer. Integration of data sets enables synergistic assessment of geology and distribution of units across multiple spatial scales. Mineralogical assessment using hyperspectral data indicates spatial relationships with mineralogical signatures, e.g., central peaks of complex craters, consistent with inferred SPA basin structure and melt differentiation (Moriarty & Pieters, 2015, JGR-P 118). Delineation of mare, cryptomare, and nonmare surfaces is key to interpreting compositional mixing in the formation of SPA regolith to interpret remotely sensed data, and for scientific assessment of landing sites. LROC Narrow Angle Camera (NAC) images show the location and distribution of >0.5 m boulders and fresh craters that constitute the main threats to automated landers and thus provide critical information for landing site assessment and planning. NAC images suitable for geometric stereo derivation and digital terrain models so derived, controlled with Lunar Orbiter Laser Altimeter (LOLA) data, and oblique NAC images made with large slews of the spacecraft, are

  7. Thorium abundances of basalt ponds in South Pole-Aitken basin: Insights into the composition and evolution of the far side lunar mantle

    Science.gov (United States)

    Hagerty, Justin J.; Lawrence, D.J.; Hawke, B.R.

    2011-01-01

    Imbrian-aged basalt ponds, located on the floor of South Pole-Aitken (SPA) basin, are used to provide constraints on the composition and evolution of the far side lunar mantle. We use forward modeling of the Lunar Prospector Gamma Ray Spectrometer thorium data, to suggest that at least five different and distinct portions of the far side lunar mantle contain little or no thorium as of the Imbrian Period. We also use spatial correlations between local thorium enhancements and nonmare material on top of the basalt ponds to support previous assertions that lower crustal materials exposed in SPA basin have elevated thorium abundances, consistent with noritic to gabbronoritic lithologies. We suggest that the lower crust on the far side of the Moon experienced multiple intrusions of thorium-rich basaltic magmas, prior to the formation of SPA basin. The fact that many of the ponds on the lunar far side have elevated titanium abundances indicates that the far side of the Moon experienced extensive fractional crystallization that likely led to the formation of a KREEP-like component. However, because the Imbrian-aged basalts contain no signs of elevated thorium, we propose that the SPA impact event triggered the transport of a KREEP-like component from the lunar far side and concentrated it on the nearside of the Moon. Because of the correlation between basaltic ponds and basins within SPA, we suggest that Imbrian-aged basaltic volcanism on the far side of the Moon was driven by basin-induced decompressional melting.

  8. Lunar impact basins and crustal heterogeneity: New western limb and far side data from galileo

    Science.gov (United States)

    Belton, M.J.S.; Head, J. W.; Pieters, C.M.; Greeley, R.; McEwen, A.S.; Neukum, G.; Klaasen, K.P.; Anger, C.D.; Carr, M.H.; Chapman, C.R.; Davies, M.E.; Fanale, F.P.; Gierasch, P.J.; Greenberg, R.; Ingersoll, A.P.; Johnson, T.; Paczkowski, B.; Pilcher, C.B.; Veverka, J.

    1992-01-01

    Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (>2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.

  9. Analysis of landing site attributes for future missions targeting the rim of the lunar South Pole Aitken basin

    Science.gov (United States)

    Koebel, David; Bonerba, Michele; Behrenwaldt, Daniel; Wieser, Matthias; Borowy, Carsten

    2012-11-01

    For the South polar lunar region between -85 and -90° Latitude an updated analyses of the solar illumination and ground station visibility conditions has been performed in the frame of a feasibility study for an ESA Lunar Lander mission. The analyses are based on the refined lunar digital elevation model provided by the Japanese Kaguya/Selene mission, originating from its LASER altimeter instrument. For the South polar region maps of integral solar illumination are presented for a mission epoch in 2016. The analysis modelling was validated with the help of a Kaguya High Definition video. The solar illumination is driving for the power subsystems of any robotic lander craft or manned lunar outpost, in case they rely on conventional photovoltaic power generation with battery buffering of shadowed periods. In addition the visibility of the terrain from a terrestrial ESA ground station was analysed. The results are presented as an integral ground contact duration map, being crucial for the operations of any lunar outpost. Considering these two quality criteria, several possible landing sites for a future lunar mission have been pre-selected. For these sites a detailed analysis of quasi-continuous illumination conditions is presented. This includes magnified maps of the pre-selected areas, showing any location's longest illumination intervals that are allowed to be interrupted by shadows with limited duration only. As a final quality criterion, the terrain topology has been analysed for its impact on the landing trajectory. From a trade-off between the three quality criteria the connecting ridge between the Shackleton and the de Gerlache was determined to provide the most favourable landing site quality. This site is located at 89°28' South, 136°40' West, and 1947 m altitude, and features and integral illumination of 85.7%. With battery energy to sustain shadows of 120 h, total mission duration of 9.37 sidereal months can be guaranteed.

  10. Magnetization in the South Pole-Aitken basin: Implications for the lunar dynamo and true polar wander

    Science.gov (United States)

    2016-10-14

    disturbances were oted ( Halekas et al., 2012 ). Consecutive orbits are ∼1 ° in longi- ude apart. At 0.2 Hz, successive magnetometer measurements are... uber , M.T., et al., 2013. Gravity field of the Moon from the gravity recovery and interior laboratory (GRAIL) mission. Science 339, 668–671. doi: 10.1126/science. 1231507 .

  11. New morphological mapping and interpretation of ejecta deposits from Orientale Basin on the Moon

    Science.gov (United States)

    Morse, Zachary R.; Osinski, Gordon R.; Tornabene, Livio L.

    2018-01-01

    Orientale Basin is one of the youngest and best-preserved multi-ring impact basins in the Solar System. The structure is ∼950 km across and is located on the western edge of the nearside of the Moon. The interior of the basin, which possesses three distinct rings and a post-impact mare fill, has been studied extensively using modern high-resolution datasets. Exterior to these rings, Orientale has an extensive ejecta blanket that extends out radially for at least 800 km from the basin rim in all directions and covers portions of both the nearside and farside of the Moon. These deposits, known as the Hevelius Formation, were first mapped using photographic data from the Lunar Orbiter IV probe. In this study, we map in detail the morphology of each distinct facies observed within the Orientale ejecta blanket using high resolution Lunar Reconnaissance Orbiter (LRO) Wide Angle Camera (WAC) and Narrow Angle Camera (NAC) images and Lunar Orbiter Laser Altimeter (LOLA) elevation data. We identified 5 unique facies within the ejecta blanket. Facies A is identified as a region of hummocky plains located in a low-lying topographic region between the Outer Rook and Cordillera rings. This facies is interpreted to be a mix of crater-derived impact melt and km-scale blocks of ballistic ejecta and host rock broken up during the modification stage and formation of the Cordillera ring. Facies B is an inner facies marked by radial grooves extending outward from the direction of the basin center. This facies is interpreted as the continuous ballistic ejecta blanket. Facies C consists of inner and outer groupings of flat smooth-surfaced deposits isolated in local topographic lows. Facies D displays characteristic sinuous ridges and lobate extensions. Facies C and D are interpreted to be impact melt-rich materials, which manifest as flows and ponds. Our observations suggest that these facies were emplaced subsequent to the ballistic ejecta blanket - most likely during the modification

  12. Pulling Marbles from a Bag: Deducing the Regional Impact History of the SPA Basin from Impact Melt Rocks

    Science.gov (United States)

    Cohen, Barbara A.; Coker, R. F.

    2009-01-01

    The South Pole-Aitken (SPA) basin is an important target for absolute age-dating. Vertical and lateral impact mixing ensures that regolith within SPA will contain rock fragments from SPA itself, local impact craters, and faraway giant basins. About 20% of the regolith at any given site is foreign [1, 2], but much of this material will be cold ejecta, not impact melt. We calculated the fraction of contributed impact melt using scaling laws to estimate the amount and provenance of impact melt, demonstrating that SPA melt is the dominant impact melt rock (>70%) likely to be present. We also constructed a statistical model to illustrate how many randomly-selected impact-melt fragments would need to be dated, and with what accuracy, to confidently reproduce the impact history of a site. A detailed impact history becomes recognizable after a few hundred to a thousand randomly-selected marbles, however, it will be useful to have more information (e.g. compositional, mineralogical, remote sensing) to group fragments. These exercises show that SPA melt has a high probability of being present in a scoop sample and that dating of a few hundred to a thousand impact-melt fragments will yield the impact history of the SPA basin.

  13. Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schroedinger Basin

    Science.gov (United States)

    Mest, S. C.; Berman, D. C.; Petro, N. E.

    2009-01-01

    In this study we use recent images and topographic data to map the geology and geomorphology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-4] in accordance with the Lunar Geologic Mapping Program. Mapping of LQ-30 began during Mest's postdoctoral appointment and has continued under the PG&G Program, from which funding became available in February 2009. Preliminary map-ping and analyses have been done using base materials compiled by Mest, but properly mosaicked and spatially registered base materials are being compiled by the USGS and should be received by the end of June 2009. The overall objective of this research is to constrain the geologic evolution of the lunar South Pole (LQ-30: 60deg -90deg S, 0deg - +/-180deg ) with specific emphasis on evaluation of a) the regional effects of basin formation on the structure and composition of the crust and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Constraining the geologic history of the lunar South Pole and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the vertical and lateral structure of the lunar regolith and crust, assessing the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of resources (e.g., H, Fe, Th) and their relationships with surface materials.

  14. The Cretaceous-Paleogene boundary in the shallow northeastern Mexican foreland basins: Evidence for paleoseismic liquefaction, tsunami deposition, and Chicxulub ejecta

    Science.gov (United States)

    Schulte, Peter; Smit, Jan; Deutsch, Alex; Friese, Andrea; Beichel, Kilian

    2010-05-01

    Understanding the depositional sequence and composition of impact ejecta is critical for the interpretation of timing and effects of the Chicxulub impact regarding the mass extinction at the Cretaceous-Paleogene (K-Pg) boundary. Preliminary investigations have shown that the shallow La Popa and Parras foreland basins in northeastern Mexico both feature outstanding and continuous 3D exposures of the Chicxulub ejecta-rich, K-Pg boundary event deposit (Lawton et al., 2005). The m-thick sand-siltstone interval directly underlying the ejecta-rich mass flows shows evidence of slumping and liquefaction, locally leading to complete disorganization and disruption of the pre-impact late Cretaceous sedimentary sequence. The subsequent ejecta-rich sequence consists of an up to one m-thick basal carbonate-rich bed that discontinuously fills a valley-like topography. Besides abundant silicic and carbonate ejecta spherules (up to 50%) that are excellently preserved, this bed includes abundant mollusks and gastropod shells, as well as vertebrate bones and teeth. The conglomeratic bed is overlain by a series of alternating fine- to medium grained calcareous sandstones with shell debris and ejecta that were deposited by repeated currents / mass flow events incorporating varying source areas. Hummocky-cross-stratified strata that mark the return to a normal out-shelf depositional regime conformably overly these sandstones. We interpret this sequence as evidence for presumably seismic-induced sediment liquefaction followed by a series of impact-related tsunami deposits. The specific depositional sequence and Fe-Mg-rich ejecta composition as well as the petrography of the sandstones all closely link the K-Pg boundary sequence in the La Popa and Parras basin to the well-known deep-water K-Pg sites in the Gulf of Mexico (e.g. El Mimbral; Smit et al., 1996; Schulte and Kontny, 2005). Lawton, T.F., et al., 2005, Geology, v. 33, p. 81-84. Smit, J. et al., 1996, GSA Special Paper v. 307, p

  15. Butterfly Ejecta

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 4 September 2003In the heavily cratered southern highlands of Mars, the type of crater seen in this THEMIS visible image is relatively rare. Elliptical craters with 'butterfly' ejecta patterns make up roughly 5% of the total crater population of Mars. They are caused by impactors which hit the surface at oblique, or very shallow angles. Similar craters are also seen in about the same abundance on the Moon and Venus.Image information: VIS instrument. Latitude -24.6, Longitude 41 East (319 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Ejecta from Ocean Impacts

    Science.gov (United States)

    Kyte, Frank T.

    2003-01-01

    Numerical simulations of deep-ocean impact provide some limits on the size of a projectile that will not mix with the ocean floor during a deep-ocean impact. For a vertical impact at asteroidal velocities (approx. 20 km/s), mixing is only likely when the projectile diameter is greater than 112 of the water depth. For oblique impacts, even larger projectiles will not mix with ocean floor silicates. Given the typical water depths of 4 to 5 km in deep-ocean basins, asteroidal projectiles with diameters as large as 2 or 3 km may commonly produce silicate ejecta that is composed only of meteoritic materials and seawater salts. However, the compressed water column beneath the projectile can still disrupt and shock metamorphose the ocean floor. Therefore, production of a separate, terrestrial ejecta component is not ruled out in the most extreme case. With increasing projectile size (or energy) relative to water depths, there must be a gradation between oceanic impacts and more conventional continental impacts. Given that 60% of the Earth's surface is covered by oceanic lithosphere and 500 m projectiles impact the Earth on 10(exp 5) y timescales, there must be hundreds of oceanic impact deposits in the sediment record awaiting discovery.

  17. Pulling Marbles from a Bag: Deducing the Regional Impact History of the SPA Basin from Impact-Melt Rocks

    Science.gov (United States)

    Cohen, Barbara A.; Coker, Robert F.

    2010-01-01

    The South Pole Aitken (SPA) basin is the stratigraphically oldest identifiable lunar basin and is therefore one of the most important targets for absolute age-dating to help understand whether ancient lunar bombardment history smoothly declined or was punctuated by a cataclysm. A feasible near-term approach to this problem is to robotically collect a sample from near the center of the basin, where vertical and lateral mixing provided by post-basin impacts ensures that such a sample will be composed of small rock fragments from SPA itself, from local impact craters, and from faraway giant basins. The range of ages, intermediate spikes in the age distribution, and the oldest ages are all part of the definition of the absolute age and impact history recorded within the SPA basin.

  18. Schooner ejecta studies

    Energy Technology Data Exchange (ETDEWEB)

    Henny, Robert W [University of New Mexico (United States)

    1970-05-15

    This paper presents a preliminary analysis of the Schooner ejecta and missile population. Our work on the Schooner event results from a continuing interest in cratering phenomenology with emphasis directed towards development of photographic techniques for the documentation of static and dynamic aspects of large ejecta and missile populations. Project Schooner was a nuclear experiment in a layered tuffaceous medium executed as part of the Plowshare program for development of nuclear excavation. Schooner was detonated on December 8, 1968 at approximately 0800:00.149.6 (PST), 1600:00.149.6 (GMT), in area 20, Nevada Test Site (NTS). The resultant yield was 31 {+-} 4 KT. The emplacement hole was U20u at geodetic coordinates: Longitude: W 116 diameter 33* 57.1419'' Latitude: N 37'' 20* 36.3187'' Surface ground zero (GZ) was 5,562.4 feet mean sea level (MSL); emplacement depth (to the working point) was 108.2 meters (355 feet). The basic crater and ejecta data are listed.

  19. Morphology and Scaling of Ejecta Deposits on Icy Satellites

    Science.gov (United States)

    Schenk, Paul M.; Ridolfi, Francis J.; Bredekamp, Joe (Technical Monitor)

    2002-01-01

    Continuous ejecta deposits on Ganymede consist of two major units, or facies: a thick inner hummocky pedestal facies, and a relatively thin outer radially scoured facies defined also by the inner limit of the secondary crater field. Both ejecta facies have a well-defined power-law relationship to crater diameter for craters ranging from 15 to approx. 600 km across. This relationship can be used to estimate the nominal crater diameter for impact features on icy satellites (such as palimpsests and multiring basins) for which the crater rim is no longer recognizable. Ejecta deposits have also been mapped on 4 other icy satellites. Although morphologically similar to eject deposits on the Moon, ejecta deposits for smaller craters are generally significantly broader in extent on the icy satellites, in apparent defiance of predictions of self-similarity. A greater degree of rim collapse and enlargement on the Moon may explain the observed difference.

  20. Compositional evidence for an impact origin of the Moon's Procellarum basin

    Science.gov (United States)

    Nakamura, Ryosuke; Yamamoto, Satoru; Matsunaga, Tsuneo; Ishihara, Yoshiaki; Morota, Tomokatsu; Hiroi, Takahiro; Takeda, Hiroshi; Ogawa, Yoshiko; Yokota, Yasuhiro; Hirata, Naru; Ohtake, Makiko; Saiki, Kazuto

    2012-11-01

    The asymmetry between the nearside and farside of the Moon is evident in the distribution of mare basalt, crustal thickness and concentrations of radioactive elements, but its origin remains controversial. According to one attractive scenario, a gigantic impact early in the Moon's history produced the observed dichotomy; the putative 3,000-km-diameter Procellarum basin has been suggested to be a relic of this ancient impact. Low-calcium pyroxene can be formed during an impact by melting a mixture of crust and mantle materials or by excavating differentiated cumulates from the lunar magma ocean. Therefore, the association of low-calcium pyroxene with a lunar basin could indicate an impact origin. Here we use spectral mapping data from KAGUYA/SELENE (ref. ) to show that low-calcium pyroxene is concentrated around two established impact structures, the South Pole-Aitken and Imbrium basins. In addition, we detect a high concentration of low-calcium pyroxene at Procellarum, which supports an impact origin of the ancient basin. We propose that, in forming the largest known basin on the Moon, the impact excavated the nearside's primary feldspathic crust, which derived from the lunar magma ocean. A secondary feldspathic crust would have later recrystallized from the sea of impact melt, leading to two distinct sides of the Moon.

  1. Ejecta evolution during cone impact

    KAUST Repository

    Marston, Jeremy

    2014-07-07

    We present findings from an experimental investigation into the impact of solid cone-shaped bodies onto liquid pools. Using a variety of cone angles and liquid physical properties, we show that the ejecta formed during the impact exhibits self-similarity for all impact speeds for very low surface tension liquids, whilst for high-surface tension liquids similarity is only achieved at high impact speeds. We find that the ejecta tip can detach from the cone and that this phenomenon can be attributed to the air entrainment phenomenon. We analyse of a range of cone angles, including some ogive cones, and impact speeds in terms of the spatiotemporal evolution of the ejecta tip. Using superhydrophobic cones, we also examine the entry of cones which entrain an air layer.

  2. Ejecta evolution during cone impact

    KAUST Repository

    Marston, Jeremy; Thoroddsen, Sigurdur T

    2014-01-01

    -similarity for all impact speeds for very low surface tension liquids, whilst for high-surface tension liquids similarity is only achieved at high impact speeds. We find that the ejecta tip can detach from the cone and that this phenomenon can be attributed

  3. Lunar Impact Basins: Stratigraphy, Sequence and Ages from Superposed Impact Crater Populations Measured from Lunar Orbiter Laser Altimeter (LOLA) Data

    Science.gov (United States)

    Fassett, C. I.; Head, J. W.; Kadish, S. J.; Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

    2012-01-01

    Impact basin formation is a fundamental process in the evolution of the Moon and records the history of impactors in the early solar system. In order to assess the stratigraphy, sequence, and ages of impact basins and the impactor population as a function of time, we have used topography from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) to measure the superposed impact crater size-frequency distributions for 30 lunar basins (D = 300 km). These data generally support the widely used Wilhelms sequence of lunar basins, although we find significantly higher densities of superposed craters on many lunar basins than derived by Wilhelms (50% higher densities). Our data also provide new insight into the timing of the transition between distinct crater populations characteristic of ancient and young lunar terrains. The transition from a lunar impact flux dominated by Population 1 to Population 2 occurred before the mid-Nectarian. This is before the end of the period of rapid cratering, and potentially before the end of the hypothesized Late Heavy Bombardment. LOLA-derived crater densities also suggest that many Pre-Nectarian basins, such as South Pole-Aitken, have been cratered to saturation equilibrium. Finally, both crater counts and stratigraphic observations based on LOLA data are applicable to specific basin stratigraphic problems of interest; for example, using these data, we suggest that Serenitatis is older than Nectaris, and Humboldtianum is younger than Crisium. Sample return missions to specific basins can anchor these measurements to a Pre-Imbrian absolute chronology.

  4. Phase Doppler anemometry as an ejecta diagnostic

    Science.gov (United States)

    Bell, D. J.; Chapman, D. J.

    2017-01-01

    When a shock wave is incident on a free surface, micron sized pieces of the material can be ejected from that surface. Phase Doppler Anemometry (PDA) is being developed to simultaneously measure the sizes and velocities of the individual shock induced ejecta particles; providing an important insight into ejecta phenomena. The results from experiments performed on the 13 mm bore light gas gun at the Institute of Shock Physics, Imperial College London are presented. Specially grooved tin targets were shocked at pressures of up to 14 GPa, below the melt on release pressure, to generate ejecta particles. These experiments are the first time that PDA has been successfully fielded on dynamic ejecta experiments. The results and current state of the art of the technique are discussed along with the future improvements required to optimise performance and increase usability.

  5. Crater ejecta scaling laws: fundamental forms based on dimensional analysis

    International Nuclear Information System (INIS)

    Housen, K.R.; Schmidt, R.M.; Holsapple, K.A.

    1983-01-01

    A model of crater ejecta is constructed using dimensional analysis and a recently developed theory of energy and momentum coupling in cratering events. General relations are derived that provide a rationale for scaling laboratory measurements of ejecta to larger events. Specific expressions are presented for ejection velocities and ejecta blanket profiles in two limiting regimes of crater formation: the so-called gravity and strength regimes. In the gravity regime, ejectra velocities at geometrically similar launch points within craters vary as the square root of the product of crater radius and gravity. This relation implies geometric similarity of ejecta blankets. That is, the thickness of an ejecta blanket as a function of distance from the crater center is the same for all sizes of craters if the thickness and range are expressed in terms of crater radii. In the strength regime, ejecta velocities are independent of crater size. Consequently, ejecta blankets are not geometrically similar in this regime. For points away from the crater rim the expressions for ejecta velocities and thickness take the form of power laws. The exponents in these power laws are functions of an exponent, α, that appears in crater radius scaling relations. Thus experimental studies of the dependence of crater radius on impact conditions determine scaling relations for ejecta. Predicted ejection velocities and ejecta-blanket profiles, based on measured values of α, are compared to existing measurements of velocities and debris profiles

  6. Evolutionary signatures in complex ejecta and their driven shocks

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2004-11-01

    Full Text Available We examine interplanetary signatures of ejecta-ejecta interactions. To this end, two time intervals of inner-heliospheric (≤1AU observations separated by 2 solar cycles are chosen where ejecta/magnetic clouds are in the process of interacting to form complex ejecta. At the Sun, both intervals are characterized by many coronal mass ejections (CMEs and flares. In each case, a complement of observations from various instruments on two spacecraft are examined in order to bring out the in-situ signatures of ejecta-ejecta interactions and their relation to solar observations. In the first interval (April 1979, data are shown from Helios-2 and ISEE-3, separated by ~0.33AU in radial distance and 28° in heliographic longitude. In the second interval (March-April 2001, data from the SOHO and Wind probes are combined, relating effects at the Sun and their manifestations at 1AU on one of Wind's distant prograde orbits. At ~0.67AU, Helios-2 observes two individual ejecta which have merged by the time they are observed at 1AU by ISEE-3. In March 2001, two distinct Halo CMEs (H-CMEs are observed on SOHO on 28-29 March approaching each other with a relative speed of 500kms-1 within 30 solar radii. In order to isolate signatures of ejecta-ejecta interactions, the two event intervals are compared with expectations for pristine (isolated ejecta near the last solar minimum, extensive observations on which were given by Berdichevsky et al. (2002. The observations from these two event sequences are then intercompared. In both event sequences, coalescence/merging was accompanied by the following signatures: heating of the plasma, acceleration of the leading ejecta and deceleration of the trailing ejecta, compressed field and plasma in the leading ejecta, disappearance of shocks and the strengthening of shocks driven by the accelerated ejecta. A search for reconnection signatures at the interface between the two ejecta in the March 2001 event was inconclusive

  7. Postshot distribution and movement of radionuclides in nuclear crater ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Koranda, John J; Martin, John R; Wikkerink, Robert; Stuart, Marshall [Bio-Medical Division, Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    The distribution and postshot movement of radionuclides in nuclear crater ejecta are discussed in this report. Continuing studies of tritium movement in ejecta at SEDAN crater demonstrate that variations in tritium concentration are correlated with seasonal rainfall and soil water movements. Losses of 27 mCi H{sup 3}/ft{sup 2} are evident on SEDAN crater lip at the end of a three year period of measurements in -which an unusually large flux of rain was received. The distribution of gamma emitting radionuclides and tritium is described in the recently created SCHOONER crater ejecta field. The specific activity of radionuclides in the SCHOONER ejecta continuum is shown for ejecta collected from the crater lip to 17 miles from GZ. The movement of W{sup 181} and tritium into the sub-ejecta preshot soil is described at a site 3000 feet from GZ. (author)

  8. A class of ejecta transport test problems

    International Nuclear Information System (INIS)

    Hammerberg, James E.; Buttler, William T.; Oro, David M.; Rousculp, Christopher L.; Morris, Christopher; Mariam, Fesseha G.

    2011-01-01

    Hydro code implementations of ejecta dynamics at shocked interfaces presume a source distribution function ofparticulate masses and velocities, f 0 (m, v;t). Some of the properties of this source distribution function have been determined from extensive Taylor and supported wave experiments on shock loaded Sn interfaces of varying surface and subsurface morphology. Such experiments measure the mass moment of f o under vacuum conditions assuming weak particle-particle interaction and, usually, fully inelastic capture by piezo-electric diagnostic probes. Recently, planar Sn experiments in He, Ar, and Kr gas atmospheres have been carried out to provide transport data both for machined surfaces and for coated surfaces. A hydro code model of ejecta transport usually specifies a criterion for the instantaneous temporal appearance of ejecta with source distribution f 0 (m, v;t 0 ). Under the further assumption of separability, f 0 (m,v;t 0 ) = f 1 (m)f 2 (v), the motion of particles under the influence of gas dynamic forces is calculated. For the situation of non-interacting particulates, interacting with a gas via drag forces, with the assumption of separability and simplified approximations to the Reynolds number dependence of the drag coefficient, the dynamical equation for the time evolution of the distribution function, f(r,v,m;t), can be resolved as a one-dimensional integral which can be compared to a direct hydro simulation as a test problem. Such solutions can also be used for preliminary analysis of experimental data. We report solutions for several shape dependent drag coefficients and analyze the results of recent planar dsh experiments in Ar and Xe.

  9. Imaging the Ejecta in Classical Novae

    Science.gov (United States)

    Linford, Justin

    2016-10-01

    A nova outburst results when sufficient mass accretes from a companion star onto the surface of a white dwarf, triggering a thermonuclear explosion. In classical novae the bulk of the emission comes from the warm, expanding ejecta. The prevailing theories assume that the explosion occurs as a single, spherically symmetric ejection event and predict a simple relationship between the white dwarf mass, the accretion rate, and the mass loss and energetics of the explosion. However, observations with modern instruments indicate that nova eruptions are far from simple. There is now evidence for multiple ejection events, common envelopes, non-spherical geometry, and even jet-like structures in the ejecta. Our ENova collaboration combines radio, mm, optical, and X-ray observations and detailed theoretical modelling to study the most common major explosions in the universe. Among our results so far are the direct demonstration of the importance of shocks in novae, including the detection of gamma-ray producing shocks in several sources, and the realization that multiple, long-lived outflows are much more common than previously assumed. Here we propose to continue these highly successful observations with coordinated detailed VLA radio interferometry and HST optical imaging and spectroscropy of several recent novae with substantial VLA monitoring already in progress.

  10. Evolutionary signatures in complex ejecta and their driven shocks

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2004-11-01

    Full Text Available We examine interplanetary signatures of ejecta-ejecta interactions. To this end, two time intervals of inner-heliospheric (≤1AU observations separated by 2 solar cycles are chosen where ejecta/magnetic clouds are in the process of interacting to form complex ejecta. At the Sun, both intervals are characterized by many coronal mass ejections (CMEs and flares. In each case, a complement of observations from various instruments on two spacecraft are examined in order to bring out the in-situ signatures of ejecta-ejecta interactions and their relation to solar observations. In the first interval (April 1979, data are shown from Helios-2 and ISEE-3, separated by ~0.33AU in radial distance and 28° in heliographic longitude. In the second interval (March-April 2001, data from the SOHO and Wind probes are combined, relating effects at the Sun and their manifestations at 1AU on one of Wind's distant prograde orbits. At ~0.67AU, Helios-2 observes two individual ejecta which have merged by the time they are observed at 1AU by ISEE-3. In March 2001, two distinct Halo CMEs (H-CMEs are observed on SOHO on 28-29 March approaching each other with a relative speed of 500kms-1 within 30 solar radii. In order to isolate signatures of ejecta-ejecta interactions, the two event intervals are compared with expectations for pristine (isolated ejecta near the last solar minimum, extensive observations on which were given by Berdichevsky et al. (2002. The observations from these two event sequences are then intercompared. In both event sequences, coalescence/merging was accompanied by the following signatures: heating of the plasma, acceleration of the leading ejecta and deceleration of the trailing ejecta, compressed field and plasma in the leading ejecta, disappearance of shocks and the strengthening of shocks driven by the accelerated ejecta. A search for reconnection signatures at the interface between the two ejecta in the March 2001 event was

  11. Ejecta from single-charge cratering explosions

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, R H

    1970-05-15

    The objective was to obtain experimental data tracing the location of ejecta to its origin within the crater region. The experiment included ten high-explosive spherical charges weighing from 8 to 1000 pounds and detonated in a playa dry lake soil on the Tonopah Test Range. Each event included from 24 to 40 locations of distinctly different tracer material embedded in a plane in the expected crater region. Tracers consisted of glass, ceramic and bugle beads, chopped metal, and plastic wire. Results of this experiment yielded data on tracer dispersion as a function of charge weight, charge burial depth and tracer emplacement position. Tracer pattern parameters such as center-of-tracer mass, range to center-of-tracer mass, and angle to center-of-tracer mass were determined. There is a clear tendency for range (to center-of-tracer mass) and the size of the dispersion pattern to decrease as tracer emplacement depth increases. Increasing tracer emplacement depth and range tends to decrease the area over which tracers are dispersed on the ground surface. Tracers at the same scaled position relative to the charge were deposited closer to the crater (on a scaled basis) as charge weight was increased. (author)

  12. (U) An Analytic Study of Piezoelectric Ejecta Mass Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tregillis, Ian Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-16

    We consider the piezoelectric measurement of the areal mass of an ejecta cloud, for the specific case where ejecta are created by a single shock at the free surface and fly ballistically through vacuum to the sensor. To do so, we define time- and velocity-dependent ejecta “areal mass functions” at the source and sensor in terms of typically unknown distribution functions for the ejecta particles. Next, we derive an equation governing the relationship between the areal mass function at the source (which resides in the rest frame of the free surface) and at the sensor (which resides in the laboratory frame). We also derive expressions for the analytic (“true”) accumulated ejecta mass at the sensor and the measured (“inferred”) value obtained via the standard method for analyzing piezoelectric voltage traces. This approach enables us to derive an exact expression for the error imposed upon a piezoelectric ejecta mass measurement (in a perfect system) by the assumption of instantaneous creation. We verify that when the ejecta are created instantaneously (i.e., when the time dependence is a delta function), the piezoelectric inference method exactly reproduces the correct result. When creation is not instantaneous, the standard piezo analysis will always overestimate the true mass. However, the error is generally quite small (less than several percent) for most reasonable velocity and time dependences. In some cases, errors exceeding 10-15% may require velocity distributions or ejecta production timescales inconsistent with experimental observations. These results are demonstrated rigorously with numerous analytic test problems.

  13. Venusian extended ejecta deposits as time-stratigraphic markers

    Science.gov (United States)

    Izenberg, Noam R.

    1992-01-01

    Use of impact crater ejects at time-stratigraphic markers was established during lunar geologic mapping efforts. The basic premise is that the deposition of impact ejecta, either by itself or mixed with impact-excavated material, is superimposed on a surface. The deposit becomes an observable, mappable unit produced in a single instant in geologic time. Up to two-thirds of Venus craters exhibit extended ejecta deposits. A reconnaissance survey of 336 craters (about 40 percent of the total population) was conducted. About half the craters examined were located in and around the Beta-Atla-Themis region, and half were spread over the western hemisphere of the planet. The survey was conducted using primarily C1-MIDR images. The preliminary survey shows: (1) of the 336 craters, 223 were found to have extended ejecta deposits. This proportion is higher than that found in other Venus crater databases by up to a factor of 2. (2) 53 percent of all extended ejecta craters were unambiguously superimposed on all volcanic and tectonic units. Crater Annia Faustina's associated parabolic ejecta deposit is clearly superimposed on volcanic flows coming from Gula Mons to the west. Parabola material from Faustina has covered the lava flows, smoothing the surface and reducing its specific backscatter cross section. The stratigraphy implies that the parabola material is the youngest observable unit in the region. (3) 12 percent of extended ejecta deposits are superimposed by volcanic materials. Crater Hwangcini has extended ejecta that has been covered by volcanic flows from a dome field to the northwest, implying that the volcanic units were emplaced subsequent to the ejecta deposit and are the youngest units in the locality. (4) It is difficult to determine the stratigraphic relationships of the remaining extended ejecta deposits in SAR at C1-MIDR resolution. Examination of higher resolution images and application of the other Magellan datasets in systematic manner should resolve

  14. Searching for Biosignatures in Exoplanetary Impact Ejecta.

    Science.gov (United States)

    Cataldi, Gianni; Brandeker, Alexis; Thébault, Philippe; Singer, Kelsi; Ahmed, Engy; de Vries, Bernard L; Neubeck, Anna; Olofsson, Göran

    2017-08-01

    With the number of confirmed rocky exoplanets increasing steadily, their characterization and the search for exoplanetary biospheres are becoming increasingly urgent issues in astrobiology. To date, most efforts have concentrated on the study of exoplanetary atmospheres. Instead, we aim to investigate the possibility of characterizing an exoplanet (in terms of habitability, geology, presence of life, etc.) by studying material ejected from the surface during an impact event. For a number of impact scenarios, we estimate the escaping mass and assess its subsequent collisional evolution in a circumstellar orbit, assuming a Sun-like host star. We calculate the fractional luminosity of the dust as a function of time after the impact event and study its detectability with current and future instrumentation. We consider the possibility to constrain the dust composition, giving information on the geology or the presence of a biosphere. As examples, we investigate whether calcite, silica, or ejected microorganisms could be detected. For a 20 km diameter impactor, we find that the dust mass escaping the exoplanet is roughly comparable to the zodiacal dust, depending on the exoplanet's size. The collisional evolution is best modeled by considering two independent dust populations, a spalled population consisting of nonmelted ejecta evolving on timescales of millions of years, and dust recondensed from melt or vapor evolving on much shorter timescales. While the presence of dust can potentially be inferred with current telescopes, studying its composition requires advanced instrumentation not yet available. The direct detection of biological matter turns out to be extremely challenging. Despite considerable difficulties (small dust masses, noise such as exozodiacal dust, etc.), studying dusty material ejected from an exoplanetary surface might become an interesting complement to atmospheric studies in the future. Key Words: Biosignatures

  15. The Ejecta Evolution of Deep Impact: Insight from Experiments

    Science.gov (United States)

    Hermalyn, B.; Schultz, P. H.; Heineck, J. T.

    2010-12-01

    The Deep Impact (DI) probe impacted comet 9P/Tempel 1 at an angle of ~30° from local horizontal with a velocity of 10.2 km/s. Examination of the resulting ballistic (e.g., non-vapor driven) ejecta revealed phenomena that largely followed expectations from laboratory investigations of oblique impacts into low-density porous material, including a downrange bias, uprange zone of avoidance, and cardioid (curved) rays (Schultz, et al, 2005, 2007). Modeling of the impact based on canonical models and scaling laws (Richardson, et al, 2007) allowed a first-order reconstruction of the event, but did not fully represent the three-dimensional nature of the ejecta flow-field in an oblique impact essential for interpretation of the DI data. In this study, we present new experimental measurements of the early-time ejecta dynamics in oblique impacts that allow a more complete reconstruction of the ballistic ejecta from the impact, including visualization of the DI encounter and predictions for the upcoming re-encounter with Tempel 1. A suite of hypervelocity 30° impact experiments into granular materials was performed at the NASA Ames Vertical Gun Range (AVGR) for the purpose of interpreting the Deep Impact event. A technique based on Particle Tracking Velocimetry (PTV) permitted non-intrusive measurement of the ejecta velocity within the ejecta curtain. The PTV system developed at the AVGR utilizes a laser light sheet projected parallel to the impact surface to illuminate horizontal “slices” of the ejecta curtain that are then recorded by multiple cameras. Particle displacement between successive frames and cameras allows determination of the three-component velocity of the ejecta curtain. Pioneering efforts with a similar technique (Anderson, et al, 2003, 2006) characterized the main-stage ejecta velocity distributions and demonstrated that asymmetries in velocity and ejection angle persist well into the far-field for oblique impacts. In this study, high-speed cameras

  16. Crater Ejecta by Day and Night

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 24 June 2004 This pair of images shows a crater and its ejecta. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -9, Longitude 164.2 East (195.8 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

  17. (U) An Analytic Examination of Piezoelectric Ejecta Mass Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tregillis, Ian Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-02

    Ongoing efforts to validate a Richtmyer-Meshkov instability (RMI) based ejecta source model [1, 2, 3] in LANL ASC codes use ejecta areal masses derived from piezoelectric sensor data [4, 5, 6]. However, the standard technique for inferring masses from sensor voltages implicitly assumes instantaneous ejecta creation [7], which is not a feature of the RMI source model. To investigate the impact of this discrepancy, we define separate “areal mass functions” (AMFs) at the source and sensor in terms of typically unknown distribution functions for the ejecta particles, and derive an analytic relationship between them. Then, for the case of single-shock ejection into vacuum, we use the AMFs to compare the analytic (or “true”) accumulated mass at the sensor with the value that would be inferred from piezoelectric voltage measurements. We confirm the inferred mass is correct when creation is instantaneous, and furthermore prove that when creation is not instantaneous, the inferred values will always overestimate the true mass. Finally, we derive an upper bound for the error imposed on a perfect system by the assumption of instantaneous ejecta creation. When applied to shots in the published literature, this bound is frequently less than several percent. Errors exceeding 15% may require velocities or timescales at odds with experimental observations.

  18. Imaging Shock Fronts in the Outer Ejecta of Eta Carinae

    Science.gov (United States)

    Smith, Nathan

    2017-08-01

    Although Eta Car has been imaged many times with HST to monitor the central star and the bright Homunculus Nebula, we propose the first WFC3 imaging of Eta Car to study the more extended Outer Ejecta from previous eruptions. WFC3 has two key filters that have not been used before to image Eta Car, which will provide critical physical information about its eruptive history: (1) F280N with WFC3/UVIS will produce the first Mg II 2800 image of Eta Car, the sharpest image of its complex Outer Ejecta, and will unambiguously trace shock fronts, and (2) F126N with WFC3/IR will sample [Fe II] 12567 arising in the densest post-shock gas. Eta Car is surrounded by a bright, soft X-ray shell seen in Chandra images, which arises from the fastest 1840s ejecta overtaking slower older material. Our recent proper motion measurements show that the outer knots were ejected in two outbursts several hundred years before the 1840s eruption, and spectroscopy of light echoes has recently revealed extremely fast ejecta during the 1840s that indicate an explosive event. Were those previous eruptions explosive as well? If so, were they as energetic, did they also have such fast ejecta, and did they have the same geometry? The structure and excitation of the Outer Ejecta hold unique clues for reconstructing Eta Car's violent mass loss history. The locations of shock fronts in circumstellar material provide critical information, because they identify past discontinuities in the mass loss. This is one of the only ways to investigate the long term (i.e. centuries) evolution and duty cycle of eruptive mass loss in the most massive stars.

  19. A Magnetar Origin for the Kilonova Ejecta in GW170817

    Science.gov (United States)

    Metzger, Brian D.; Thompson, Todd A.; Quataert, Eliot

    2018-04-01

    The neutron star (NS) merger GW170817 was followed over several days by optical-wavelength (“blue”) kilonova (KN) emission likely powered by the radioactive decay of light r-process nuclei synthesized by ejecta with a low neutron abundance (electron fraction Y e ≈ 0.25–0.35). While the composition and high velocities of the blue KN ejecta are consistent with shock-heated dynamical material, the large quantity is in tension with the results of numerical simulations. We propose an alternative ejecta source: the neutrino-heated, magnetically accelerated wind from the strongly magnetized hypermassive NS (HMNS) remnant. A rapidly spinning HMNS with an ordered surface magnetic field of strength B ≈ (1–3) × 1014 G and lifetime t rem ∼ 0.1–1 s can simultaneously explain the velocity, total mass, and electron fraction of the blue KN ejecta. The inferred HMNS lifetime is close to its Alfvén crossing time, suggesting that global magnetic torques could be responsible for bringing the HMNS into solid-body rotation and instigating its gravitational collapse. Different origins for the KN ejecta may be distinguished by their predictions for the emission in the first hours after the merger, when the luminosity is enhanced by heating from internal shocks; the latter are likely generic to any temporally extended ejecta source (e.g., magnetar or accretion disk wind) and are not unique to the emergence of a relativistic jet. The same shocks could mix and homogenize the composition to a low but nonzero lanthanide mass fraction, {X}La}≈ {10}-3, as advocated by some authors, but only if the mixing occurs after neutrons are consumed in the r-process on a timescale ≳1 s.

  20. Interstellar and ejecta dust in the cas a supernova remnant

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, Richard G. [CRESST, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Dwek, Eli; Kober, Gladys [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Rho, Jeonghee [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Hwang, Una, E-mail: Richard.G.Arendt@nasa.gov [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2014-05-01

    Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant (SNR). Using low-resolution Spitzer IRS spectra (5-35 μm), and broad-band Herschel PACS imaging (70, 100, and 160 μm), we identify characteristic dust spectra, associated with ejecta layers that underwent distinct nuclear burning histories. The most luminous spectrum exhibits strong emission features at ∼9 and 21 μm and is closely associated with ejecta knots with strong Ar emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low Mg to Si ratios. Another dust spectrum is associated with ejecta having strong Ne emission lines. It has no indication of any silicate features and is best fit by Al{sub 2}O{sub 3} dust. A third characteristic dust spectrum shows features that are best matched by magnesium silicates with a relatively high Mg to Si ratio. This dust is primarily associated with the X-ray-emitting shocked ejecta, but it is also evident in regions where shocked interstellar or circumstellar material is expected. However, the identification of dust composition is not unique, and each spectrum includes an additional featureless dust component of unknown composition. Colder dust of indeterminate composition is associated with emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. Most of the dust mass in Cas A is associated with this unidentified cold component, which is ≲ 0.1 M {sub ☉}. The mass of warmer dust is only ∼0.04 M {sub ☉}.

  1. Mass loading of the Earth's magnetosphere by micron size lunar ejecta. 1: Ejecta production and orbital dynamics in cislunar space

    Science.gov (United States)

    Alexander, W. M.; Tanner, W. G.; Anz, P. D.; Chen, A. L.

    1986-01-01

    Particulate matter possessing lunar escape velocity sufficient to enhance the cislunar meteroid flux was investigated. While the interplanetary flux was extensively studied, lunar ejecta created by the impact of this material on the lunar surface is only now being studied. Two recently reported flux models are employed to calculate the total mass impacting the lunar surface due to sporadic meteor flux. There is ample evidence to support the contention that the sporadic interplanetary meteoroid flux enhances the meteroid flux of cislunar space through the creation of micron and submicron lunar ejecta with lunar escape velocity.

  2. The Links Between Target Properties and Layered Ejecta Craters in Acidalia and Utopia Planitiae Mars

    Science.gov (United States)

    Jones, E.; Osinski, G. R.

    2013-08-01

    Layered ejecta craters on Mars may form from excavation into subsurface volatiles. We examine a new catalogue of martian craters to decipher differences between the single- and double-layered ejecta populations in Acidalia and Utopia.

  3. Geologic implications of the Apollo 14 Fra Mauro breccias and comparison with ejecta from the Ries Crater, Germany

    Science.gov (United States)

    Chao, E.C.T.

    1973-01-01

    On the basis of petrographic and laboratory and active seismic data for the Fra Mauro breccias, and by comparison with the nature and distribution of the ejecta from the Ries crater, Germany, some tentative conclusions regarding the geologic significance of the Fra Mauro Formation on the moon can be drawn. The Fra Mauro Formation, as a whole, consists of unwcldcd, porous ejecta, slightly less porous than the regolith. It contains hand-specimen and larger size clasts of strongly annealed complex breccias, partly to slightly annealed breccias, basalts, and perhaps spherule-rich breccias. These clasts are embedded in a matrix of porous aggregate dominated by mineral and breccia fragments and probably largely free of undevitrified glass. All strongly annealed hand-specimen-size breccias are clasts in the Fra Mauro Formation. To account for the porous, unwelded state of the Fra Mauro Formation, the ejecta must have been deposited at a temperature below that required for welding and annealing. Large boulders probably compacted by the Cone crater event occur near the rim of the crater. They probably consist of a similar suite of fragments, but are probably less porous than the formation. The geochronologic clocks of fragments in the Fra Mauro Formation, with textures ranging from unannealed to strongly annealed, were not reset or strongly modified by the Imbrian event. Strongly annealed breccia clasts and basalt clasts are pre-Imbrian, and probably existed as ejecta mixed with basalt flows in the Imbrium Basin prior to the Imbrian event. The Imbrian event probably occurred between 3.90 or 3.88 and 3.65 b.y. ago.

  4. THE MORPHOLOGY OF IRC+10420's CIRCUMSTELLAR EJECTA

    International Nuclear Information System (INIS)

    Tiffany, Chelsea; Humphreys, Roberta M.; Jones, Terry J.; Davidson, Kris

    2010-01-01

    Images of the circumstellar ejecta associated with the post-red supergiant IRC+10420 show a complex ejecta with visual evidence for episodic mass loss. In this paper, we describe the transverse motions of numerous knots, arcs, and condensations in the inner ejecta measured from second epoch Hubble Space Telescope/WFPC2 images. When combined with the radial motions for several of the features, the total space motion and direction of the outflows show that they were ejected at different times, in different directions, and presumably from separate regions on the surface of the star. These discrete structures in the ejecta are kinematically distinct from the general expansion of the nebula and their motions are dominated by their transverse velocities. They are apparently all moving within a few degrees of the plane of the sky. We are thus viewing IRC+10420 nearly pole-on and looking nearly directly down onto its equatorial plane. We also discuss the role of surface activity and magnetic fields on IRC+10420's recent mass-loss history.

  5. Ordinary Chondrites Viewed as Reassembled 'Splash Ejecta'

    Science.gov (United States)

    Sanders, I. S.

    1995-09-01

    A case has already been made favouring chondrites as re-assembled "splash ejecta" following low velocity collisions between molten planetesimals[1]. Here I briefly review this hypothesis, then develop further arguments in its support. The scenario envisaged may be summarized as follows. Planetesimals grew to radii greater than 30 km in less than 1 Ma after the formation of CAIs, and they were heated rapidly by the decay of 26Al. By 2 Ma each planetesimal had a molten interior insulated by a cool, dusty carapace. Low velocity collisions at this stage released enormous, turbulent, expanding clouds of incandescent spray mixed with dust and solid grains from the carapace. The cloud constituted a rather special, transient nebular environment; as it cooled the melt droplets became chondrules. Much of the cloud's contents re-assembled under gravity onto the surface of the hot, residual planetesimal and the accumulated debris became re-heated and metamorphosed. Collisions recurred over the few million years that relative velocities remained low and planetesimals remained molten. Thus, the cumulative debris contained many recycled and broken chondrules. This scenario is apparently reconcilable with chondrule cooling rates, the preservation of clasts of "planetary" rock in chondrites, the retention of volatiles in chondrules, the preservation of solar chemistry and more than a dozen other features. Is it reasonable to claim that 30 km radius bodies existed by 1 Ma, and were substantially molten by 2 Ma? Cameron[2] argued that CAIs were saved from drifting into the sun by their incorporation, soon after formation, into planetesimals whose mass was sufficient to hold them in orbits, decoupled from the drag of nebular gas. Wetherill's models [3] show that many bodies >100 km radius may have formed on a timescale of 10^5 years. In these terms, the proposed 30 km by 1 Ma is quite conservative. Regarding 26Al heating, the remarkably constant initial ratio of 26Al/27Al (5 x 10

  6. LCROSS Impact Conditions and Ejecta Evolution: Insight from Experiments

    Science.gov (United States)

    Hermalyn, B.; Schultz, P. H.; Colaprete, A.

    2009-12-01

    The ejecta distribution resulting from an impact event reflects the impact conditions and target material properties. The Lunar CRater Observation and Sensing Satellite (LCROSS) mission will provide a rare look at subsurface materials. The LCROSS impact will excavate regolith from a permanently shadowed crater on the south pole of the moon. The impactor, named the Earth-Departure-Upper-Stage (EDUS), will impact the surface at ~2.5km/s at an angle of greater than 80° from horizontal. The trailing Shepherding Spacecraft (SSc) will record the impact and take measurements of the ejecta in coordination with a comprehensive earth-based observational campaign. Prior studies have explored the predicted ejecta mass/velocity distribution and general ejecta dynamics through computational modeling (Korycansky, et al 2009) and scaling laws(Schultz, 2006, Heldmann et al 2007). At very early times, however, these models and scaling laws break down. It is this high-speed component of the ejected material that will reach the sunlight horizon first and will be recorded by the SSc. Thus to interpret the initial conditions of the impact from the LCROSS ejecta plume, the early-time ejecta distribution must be understood. A suite of impact experiments (performed at the NASA Ames Vertical Gun Range, or AVGR) were designed to interpret LCROSS conditions. These experiments reveal that early in the cratering process, when the projectile is still coupling its energy and momentum to the target surface, ejection velocity is higher than predicted by dimensional scaling laws (Housen, et al 1983). Moreover, the ejection angles of this early-time component are initially lower than predicted, and sweep upward tens of degrees to reach nominal ejection angles (~45° for impacts into sand). Low-density projectiles (such as the EDUS) yield even lower ejection angles throughout much of crater growth, thereby indicating a shallower depth of coupling. An estimate of mass above a given height calculated

  7. Erosion and Ejecta Reaccretion on 243 Ida and Its Moon

    Science.gov (United States)

    Geissler, Paul; Petit, Jean-Marc; Durda, Daniel D.; Greenberg, Richard; Bottke, William; Nolan, Michael; Moore, Jeffrey

    1996-03-01

    Galileo images of Asteroid 243 Ida and its satellite Dactyl show surfaces which are dominantly shaped by impact cratering. A number of observations suggest that ejecta from hypervelocity impacts on Ida can be distributed far and wide across the Ida system, following trajectories substantially affected by the low gravity, nonspherical shape, and rapid rotation of the asteroid. We explore the processes of reaccretion and escape of ejecta on Ida and Dactyl using three-dimensional numerical simulations which allow us to compare the theoretical effects of orbital dynamics with observations of surface morphology. The effects of rotation, launch location, and initial launch speed are first examined for the case of an ideal triaxial ellipsoid with Ida's approximate shape and density. Ejecta launched at low speeds (V≪Vesc) reimpact near the source craters, forming well-defined ejecta blankets which are asymmetric in morphology between leading and trailing rotational surfaces. The net effect of cratering at low ejecta launch velocities is to produce a thick regolith which is evenly distributed across the surface of the asteroid. In contrast, no clearly defined ejecta blankets are formed when ejecta is launched at higher initial velocities (V∼Vesc). Most of the ejecta escapes, while that which is retained is preferentially derived from the rotational trailing surfaces. These particles spend a significant time in temporary orbit around the asteroid, in comparison to the asteroid's rotation period, and tend to be swept up onto rotational leading surfaces upon reimpact. The net effect of impact cratering with high ejecta launch velocities is to produce a thinner and less uniform soil cover, with concentrations on the asteroids' rotational leading surfaces. Using a realistic model for the shape of Ida (P. Thomas, J. Veverka, B. Carcich, M. J. S. Belton, R. Sullivan, and M. Davies 1996,Icarus120, 000-000), we find that an extensive color/albedo unit which dominates the

  8. In plain sight: the Chesapeake Bay crater ejecta blanket

    Science.gov (United States)

    Griscom, D. L.

    2012-02-01

    The discovery nearly two decades ago of a 90 km-diameter impact crater below the lower Chesapeake Bay has gone unnoted by the general public because to date all published literature on the subject has described it as "buried". To the contrary, evidence is presented here that the so-called "upland deposits" that blanket ∼5000 km2 of the U.S. Middle-Atlantic Coastal Plain (M-ACP) display morphologic, lithologic, and stratigraphic features consistent with their being ejecta from the 35.4 Ma Chesapeake Bay Impact Structure (CBIS) and absolutely inconsistent with the prevailing belief that they are of fluvial origin. Specifically supporting impact origin are the facts that (i) a 95 %-pure iron ore endemic to the upland deposits of southern Maryland, eastern Virginia, and the District of Columbia has previously been proven to be impactoclastic in origin, (ii) this iron ore welds together a small percentage of well-rounded quartzite pebbles and cobbles of the upland deposits into brittle sheets interpretable as "spall plates" created in the interference-zone of the CBIS impact, (iii) the predominantly non-welded upland gravels have long ago been shown to be size sorted with an extreme crater-centric gradient far too large to have been the work of rivers, but well explained as atmospheric size-sorted interference-zone ejecta, (iv) new evidence is provided here that ~60 % of the non-welded quartzite pebbles and cobbles of the (lower lying) gravel member of the upland deposits display planar fractures attributable to interference-zone tensile waves, (v) the (overlying) loam member of the upland deposits is attributable to base-surge-type deposition, (vi) several exotic clasts found in a debris flow topographically below the upland deposits can only be explained as jetting-phase crater ejecta, and (vii) an allogenic granite boulder found among the upland deposits is deduced to have been launched into space and sculpted by hypervelocity air friction during reentry. An

  9. A crater and its ejecta: An interpretation of Deep Impact

    Science.gov (United States)

    Holsapple, Keith A.; Housen, Kevin R.

    2007-03-01

    We apply recently updated scaling laws for impact cratering and ejecta to interpret observations of the Deep Impact event. An important question is whether the cratering event was gravity or strength-dominated; the answer gives important clues about the properties of the surface material of Tempel 1. Gravity scaling was assumed in pre-event calculations and has been asserted in initial studies of the mission results. Because the gravity field of Tempel 1 is extremely weak, a gravity-dominated event necessarily implies a surface with essentially zero strength. The conclusion of gravity scaling was based mainly on the interpretation that the impact ejecta plume remained attached to the comet during its evolution. We address that feature here, and conclude that even strength-dominated craters would result in a plume that appeared to remain attached to the surface. We then calculate the plume characteristics from scaling laws for a variety of material types, and for gravity and strength-dominated cases. We find that no model of cratering alone can match the reported observation of plume mass and brightness history. Instead, comet-like acceleration mechanisms such as expanding vapor clouds are required to move the ejected mass to the far field in a few-hour time frame. With such mechanisms, and to within the large uncertainties, either gravity or strength craters can provide the levels of estimated observed mass. Thus, the observations are unlikely to answer the questions about the mechanical nature of the Tempel 1 surface.

  10. Generation and emplacement of fine-grained ejecta in planetary impacts

    Science.gov (United States)

    Ghent, R.R.; Gupta, V.; Campbell, B.A.; Ferguson, S.A.; Brown, J.C.W.; Fergason, R.L.; Carter, L.M.

    2010-01-01

    We report here on a survey of distal fine-grained ejecta deposits on the Moon, Mars, and Venus. On all three planets, fine-grained ejecta form circular haloes that extend beyond the continuous ejecta and other types of distal deposits such as run-out lobes or ramparts. Using Earth-based radar images, we find that lunar fine-grained ejecta haloes represent meters-thick deposits with abrupt margins, and are depleted in rocks 1cm in diameter. Martian haloes show low nighttime thermal IR temperatures and thermal inertia, indicating the presence of fine particles estimated to range from ???10??m to 10mm. Using the large sample sizes afforded by global datasets for Venus and Mars, and a complete nearside radar map for the Moon, we establish statistically robust scaling relationships between crater radius R and fine-grained ejecta run-out r for all three planets. On the Moon, ???R-0.18 for craters 5-640km in diameter. For Venus, radar-dark haloes are larger than those on the Moon, but scale as ???R-0.49, consistent with ejecta entrainment in Venus' dense atmosphere. On Mars, fine-ejecta haloes are larger than lunar haloes for a given crater size, indicating entrainment of ejecta by the atmosphere or vaporized subsurface volatiles, but scale as R-0.13, similar to the ballistic lunar scaling. Ejecta suspension in vortices generated by passage of the ejecta curtain is predicted to result in ejecta run-out that scales with crater size as R1/2, and the wind speeds so generated may be insufficient to transport particles at the larger end of the calculated range. The observed scaling and morphology of the low-temperature haloes leads us rather to favor winds generated by early-stage vapor plume expansion as the emplacement mechanism for low-temperature halo materials. ?? 2010 Elsevier Inc.

  11. UNBURNED MATERIAL IN THE EJECTA OF TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Folatelli, Gastón; Tanaka, Masaomi; Maeda, Keiichi; Nomoto, Ken'ichi; Phillips, M. M.; Morrell, Nidia; Campillay, Abdo; González, Sergio; Roth, Miguel; Stritzinger, Maximilian; Burns, Christopher R.; Freedman, W. L.; Madore, Barry F; Persson, S. E.; Hamuy, Mario; Mazzali, Paolo; Boldt, Luis; Contreras, Carlos; Salgado, Francisco; Suntzeff, Nicholas B.

    2012-01-01

    The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project. The tell-tale signature of pristine material from a C+O white dwarf progenitor star is the presence of carbon, as oxygen is also a product of carbon burning. The most prominent carbon lines in optical spectra of SNe Ia are expected to arise from C II. We find that at least 30% of the objects in the sample show an absorption at ≈6300 Å which is attributed to C II λ6580. An alternative identification of this absorption as Hα is considered to be unlikely. These findings imply a larger incidence of carbon in SNe Ia ejecta than previously noted. We show how observational biases and physical conditions may hide the presence of weak C II lines, and account for the scarcity of previous carbon detections in the literature. This relatively large frequency of carbon detections has crucial implications on our understanding of the explosive process. Furthermore, the identification of the 6300 Å absorptions as carbon would imply that unburned material is present at very low expansion velocities, merely ≈1000 km s –1 above the bulk of Si II. Based on spectral modeling, it is found that the detections are consistent with a mass of carbon of 10 –3 to 10 –2 M ☉ . The presence of this material so deep in the ejecta would imply substantial mixing, which may be related to asymmetries of the flame propagation. Another possible explanation for the carbon absorptions may be the existence of clumps of unburned material along the line of sight. However, the uniformity of the relation between C II and Si II velocities is not consistent with such small-scale asymmetries. The spectroscopic and photometric properties of SNe Ia with and without carbon signatures are compared. A trend toward bluer color and lower luminosity at maximum light is found for objects which show carbon.

  12. UNBURNED MATERIAL IN THE EJECTA OF TYPE Ia SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Folatelli, Gaston; Tanaka, Masaomi; Maeda, Keiichi; Nomoto, Ken' ichi [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Phillips, M. M.; Morrell, Nidia; Campillay, Abdo; Gonzalez, Sergio; Roth, Miguel [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Stritzinger, Maximilian [The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm (Sweden); Burns, Christopher R.; Freedman, W. L.; Madore, Barry F; Persson, S. E. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Hamuy, Mario [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Mazzali, Paolo [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); Boldt, Luis [Argelander Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, D-53111 Bonn (Germany); Contreras, Carlos [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Victoria 3122 (Australia); Salgado, Francisco [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Suntzeff, Nicholas B., E-mail: gaston.folatelli@ipmu.jp [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)

    2012-01-20

    The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project. The tell-tale signature of pristine material from a C+O white dwarf progenitor star is the presence of carbon, as oxygen is also a product of carbon burning. The most prominent carbon lines in optical spectra of SNe Ia are expected to arise from C II. We find that at least 30% of the objects in the sample show an absorption at Almost-Equal-To 6300 A which is attributed to C II {lambda}6580. An alternative identification of this absorption as H{alpha} is considered to be unlikely. These findings imply a larger incidence of carbon in SNe Ia ejecta than previously noted. We show how observational biases and physical conditions may hide the presence of weak C II lines, and account for the scarcity of previous carbon detections in the literature. This relatively large frequency of carbon detections has crucial implications on our understanding of the explosive process. Furthermore, the identification of the 6300 A absorptions as carbon would imply that unburned material is present at very low expansion velocities, merely Almost-Equal-To 1000 km s{sup -1} above the bulk of Si II. Based on spectral modeling, it is found that the detections are consistent with a mass of carbon of 10{sup -3} to 10{sup -2} M{sub Sun }. The presence of this material so deep in the ejecta would imply substantial mixing, which may be related to asymmetries of the flame propagation. Another possible explanation for the carbon absorptions may be the existence of clumps of unburned material along the line of sight. However, the uniformity of the relation between C II and Si II velocities is not consistent with such small-scale asymmetries. The spectroscopic and photometric properties of SNe Ia with and without carbon signatures are compared. A trend toward bluer color and lower luminosity at maximum light is found for

  13. Near-Earth Reconnection Ejecta at Lunar Distances

    Science.gov (United States)

    Runov, A.; Angelopoulos, V.; Artemyev, A.; Lu, S.; Zhou, X.-Z.

    2018-04-01

    Near-Earth magnetotail reconnection leads to formation of earthward and tailward directed plasma outflows with an increased north-south magnetic field strength(|Bz|) at their leading edges. We refer to these regions of enhanced |Bz| and magnetic flux transport Ey as reconnection ejecta. They are composed of what have been previously referred to as earthward dipolarizing flux bundles (DFBs) and tailward rapid flux transport (RFT) events. Using two-point observations of magnetic and electric fields and particle fluxes by the Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun probes orbiting around Moon at geocentric distances R ˜ 60RE, we statistically studied plasma moments and particle energy spectra in RFTs and compared them with those observed within DFBs in the near-Earth plasma sheet by the Time History of Events and Macroscale Interactions during Substorms probes. We found that the ion average temperatures and spectral slopes in RFTs at R ˜ 60RE are close to those in DFBs observed at 15 balance, the average RFT ion temperature corresponds to a lobe field BL˜20 nT. This leads us to suggest that the ion population within the tailward ejecta originated in the midtail plasma sheet at 20≤R≤30RE and propagated to the Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun location without undergoing any further energy gain. Conversely, electron temperatures in DFBs at 15 < R < 25RE are a factor of 2.5 higher than those in RFTs at R ˜ 60RE.

  14. MEASURING EJECTA VELOCITY IMPROVES TYPE Ia SUPERNOVA DISTANCES

    International Nuclear Information System (INIS)

    Foley, Ryan J.; Kasen, Daniel

    2011-01-01

    We use a sample of 121 spectroscopically normal Type Ia supernovae (SNe Ia) to show that their intrinsic color is correlated with their ejecta velocity, as measured from the blueshift of the Si II λ6355 feature near maximum brightness, v SiII . The SN Ia sample was originally used by Wang et al. to show that the relationship between color excess and peak magnitude, which in the absence of intrinsic color differences describes a reddening law, was different for two subsamples split by v SiII (defined as 'Normal' and 'High Velocity'). We verify this result, but find that the two subsamples have the same reddening law when extremely reddened events (E(B - V)>0.35 mag) are excluded. We also show that (1) the High-Velocity subsample is offset by ∼0.06 mag to the red from the Normal subsample in the (B max - V max )-M V plane, (2) the B max - V max cumulative distribution functions of the two subsamples have nearly identical shapes, but the High-Velocity subsample is offset by ∼0.07 mag to the red in B max - V max , and (3) the bluest High-Velocity SNe Ia are ∼0.10 mag redder than the bluest Normal SNe Ia. Together, this evidence indicates a difference in intrinsic color for the subsamples. Accounting for this intrinsic color difference reduces the scatter in Hubble residuals from 0.190 mag to 0.130 mag for SNe Ia with A V ∼ V found in large SN Ia samples. We explain the correlation between ejecta velocity and color as increased line blanketing in the High-Velocity SNe Ia, causing them to become redder. We discuss some implications of this result, and stress the importance of spectroscopy for future SN Ia cosmology surveys, with particular focus on the design of WFIRST.

  15. Distal Ejecta from Lunar Impacts: Extensive Regions of Rocky Deposits

    Science.gov (United States)

    Bandfield, Joshua L.; Cahill, Joshua T. S.; Carter, Lynn M.; Neish, Catherine D.; Patterson, G. Wesley; Williams, Jean-Pierre; Paige, David A.

    2016-01-01

    Lunar Reconnaissance Orbiter (LRO) Diviner Radiometer, Mini-RF, and LRO Camera data were used to identify and characterize rocky lunar deposits that appear well separated from any potential source crater. Two regions are described: 1) A approximate 18,000 sq km area with elevated rock abundance and extensive melt ponds and veneers near the antipode of Tycho crater (167.5 deg E, 42.5 deg N). This region has been identified previously, using radar and aging data. 2) A much larger and more diffuse region, covering approximately 730,000 sq km, centered near 310 deg E, 35 deg S, containing elevated rock abundance and numerous granular flow deposits on crater walls. The rock distributions in both regions favor certain slope azimuths over others, indicating a directional component to the formation of these deposits. The spatial distribution of rocks is consistent with the arrival of ejecta from the west and northwest at low angles (approximately 10-30 deg) above the horizon in both regions. The derived age and slope orientations of the deposits indicate that the deposits likely originated as ejecta from the Tycho impact event. Despite their similar origin, the deposits in the two regions show significant differences in the datasets. The Tycho crater antipode deposit covers a smaller area, but the deposits are pervasive and appear to be dominated by impact melts. By contrast, the nearside deposits cover a much larger area and numerous granular flows were triggered. However, the features in this region are less prominent with no evidence for the presence of impact melts. The two regions appear to be surface expressions of a distant impact event that can modify surfaces across wide regions, resulting in a variety of surface morphologies. The Tycho impact event may only be the most recent manifestation of these processes, which likely have played a role in the development of the regolith throughout lunar history

  16. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 4: Flow Ejecta Crater Distribution

    Science.gov (United States)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    Flow ejecta craters - craters surrounded by lobate ejecta blankets - are found throughout the study area. The ratio of the crater's diameter to that of the flow ejecta in this region is approximately 40 to 45%. Flow ejecta craters are dominantly sharply defined craters, with slightly degraded craters being somewhat less common. This is probably indicative of the ejecta's relatively low resistence to weathering and susceptibility to burial. Flow ejecta craters here seem to occur within a narrow range of crater sizes - the smallest being about 4km in diameter and the largest being about 27km in diameter. Ejecta blankets of craters at 4km are easily seen and those of smaller craters are simply not seen even in images with better than average resolution for the region. This may be due to the depth of excavation of small impacting bodies being insufficient to reach volatile-rich material. Flow ejecta craters above 24km are rare, and those craters above 27km do not display flow ejecta blankets. This may be a result of an excavation depth so great that the volatile content of the ejecta is insufficient to form a fluid ejecta blanket. The geomorphic/geologic unit appears also to play an important role in the formation of flow ejecta craters. Given the typical size range for the occurrence of flow ejecta craters for most units, it can be seen that the percentage of flow ejecta craters to the total number of craters within this size range varies significantly from one unit to the next. The wide variance in flow ejecta crater density over this relatively small geographical area argues strongly for a lithologic control of their distribution.

  17. Geomorphology of crater and basin deposits - Emplacement of the Fra Mauro formation

    Science.gov (United States)

    Morrison, R. H.; Oberbeck, V. R.

    1975-01-01

    Characteristics of continuous deposits near lunar craters larger than about 1 km wide are considered, and it is concluded that (1) concentric dunes, radial ridges, and braided lineations result from deposition of the collision products of ejecta from adjacent pairs of similarly oriented secondary-crater chains and are, therefore, concentrations of secondary-crater ejecta; (2) intracrater ridges are produced within preexisting craters surrounding a fresh primary crater by ricocheting and focusing of secondary-crater ejecta from the preexisting craters' walls; and (3) secondary cratering has produced many of the structures of the continuous deposits of relatively small lunar craters and is the dominant process for emplacement of most of the radial facies of the continuous deposits of large lunar craters and basins. The percentages of Imbrium ejecta in deposits and the nature of Imbrium sculpturing are investigated.

  18. Glass Spherules in Badenian Siliciclastics and Carbonates of N. Croatia, Possible Ries Crater Distal Ejecta

    Science.gov (United States)

    Calogovic, M.; Marjanac, T.; Fazinic, S.; Sremac, J.; Bosnjak, M.; Bosak, L.

    2017-07-01

    We have found glass spherules in Badenian sediments at three locations in Northern Croatia that are good candidates for Ries Crater distal ejecta. Their chemical composition generally fits the composition of suevite glass.

  19. Geology of Southern Quintana Roo (Mexico) and the Chicxulub Ejecta Blanket

    Science.gov (United States)

    Schönian, F.; Tagle, R.; Stöffler, D.; Kenkmann, T.

    2005-03-01

    In southern Quintana Roo (Mexico) the Chicxulub ejecta blanket is discontinuously filling a karstified pre-KT land surface. This suggests a completely new scenario for the geological evolution of the southern Yucatán Peninsula.

  20. Microimpact phenomena on Australasian microtektites: Implications for ejecta plume characteristics and lunar surface processes

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Sudhakar, M.

    . The microimpacts are a consequence of interparticle collisions within the ejecta plume (as suggested by their chemistry) subsequent to a major impact and, therefore, reveal processes inherent in an impact-generated plume. All the impact phenomena observed here have...

  1. Overview of the Chicxulub impactite and proximal ejecta

    Science.gov (United States)

    Claeys, Ph

    2003-04-01

    Several types of impactites have now been recovered from the various wells drilled in the Chicxulub crater in Yucatan. The old Pemex wells (Yucatan 6 and Chicxulub 1) contain a highly heterogeneous and stratified suevite, which upper unit is unusually rich in carbonates, impact breccia and a possibly an impact melt at the very bottom of C1. They are located towards the crater center (C1), on the flank of the peak ring (Y6). The thickness of impactite in this zone exceeds 250 m. The UNAM wells just outside the crater rim reveal sedimentary breccia and a fall-out suevite richer in silicate melt and basement fragments, than its crater equivalent. There, the thickness of the impactite was probably several hundred meters, considering that its top might have been eroded. It can also be speculated that a cover of fall-back suevite extended over the ejecta blanket in Yucatan, all the way to Belize and perhaps even to the region of Tabasco, in Southern Mexico. The recently drilled Yaxcopoil contains about 100 m of impactites, which is currently under study. Preliminary data seem to show less variability than the material recovered from Y6. As in the UNAM well, the impactite is dominated by basement material, and shows alternating severely altered and better preserved horizons.

  2. Australasian microtektites from the Central Indian Basin: Implications for ejecta distribution patterns

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Sudhakar, M.

    , stratigraphic position, chemical composition and geographic occurrence. Their chemistry reveals that among the analysed specimens, a majority belong to the 'normal' microtektite clan, one has a high Mg (HMg) composition shown by bottle green microtektites...

  3. Mass loading of the Earth's magnetosphere by micron size lunar ejecta. 2: Ejecta dynamics and enhanced lifetimes in the Earth's magnetosphere

    Science.gov (United States)

    Alexander, W. M.; Tanner, W. G.; Anz, P. D.; Chen, A. L.

    1986-01-01

    Extensive studies were conducted concerning the indivdual mass, temporal and positional distribution of micron and submicron lunar ejecta existing in the Earth-Moon gravitational sphere of influence. Initial results show a direct correlation between the position of the Moon, relative to the Earth, and the percentage of lunar ejecta leaving the Moon and intercepting the magnetosphere of the Earth at the magnetopause surface. It is seen that the Lorentz Force dominates all other forces, thus suggesting that submicron dust particles might possibly be magnetically trapped in the well known radiation zones.

  4. Preflow stresses in Martian rampart ejecta blankets - A means of estimating the water content

    Science.gov (United States)

    Woronow, A.

    1981-01-01

    Measurements of extents of rampart ejecta deposits as a function of the size of the parent craters support models which, for craters larger than about 6 km diameter, constrain ejecta blankets to all have a similar maximum thickness regardless of the crater size. These volatile-rich ejecta blankets may have failed under their own weights, then flowed radially outward. Assuming this to be so, some of the physicomechanical properties of the ejecta deposits at the time of their emplacement can then be determined. Finite-element studies of the stress magnitudes, distributions, and directions in hypothetical Martian rampart ejecta blankets reveal that the material most likely failed when the shear stresses were less than 500 kPa and the angle of internal friction was between 26 and 36 deg. These figures imply that the ejecta has a water content between 16 and 72%. Whether the upper limit or the lower limit is more appropriate depends on the mode of failure which one presumes: namely, viscous flow of plastic deformation.

  5. Supernova ejecta with a relativistic wind from a central compact object: a unified picture for extraordinary supernovae

    Science.gov (United States)

    Suzuki, Akihiro; Maeda, Keiichi

    2017-04-01

    The hydrodynamical interaction between freely expanding supernova ejecta and a relativistic wind injected from the central region is studied in analytic and numerical ways. As a result of the collision between the ejecta and the wind, a geometrically thin shell surrounding a hot bubble forms and expands in the ejecta. We use a self-similar solution to describe the early dynamical evolution of the shell and carry out a two-dimensional special relativistic hydrodynamic simulation to follow further evolution. The Rayleigh-Taylor instability inevitably develops at the contact surface separating the shocked wind and ejecta, leading to the complete destruction of the shell and the leakage of hot gas from the hot bubble. The leaking hot materials immediately catch up with the outermost layer of the supernova ejecta and thus different layers of the ejecta are mixed. We present the spatial profiles of hydrodynamical variables and the kinetic energy distributions of the ejecta. We stop the energy injection when a total energy of 1052 erg, which is 10 times larger than the initial kinetic energy of the supernova ejecta, is deposited into the ejecta and follow the subsequent evolution. From the results of our simulations, we consider expected emission from supernova ejecta powered by the energy injection at the centre and discuss the possibility that superluminous supernovae and broad-lined Ic supernovae could be produced by similar mechanisms.

  6. Surface erosion and sedimentation caused by ejecta from the lunar crater Tycho

    Science.gov (United States)

    Shkuratov, Y.; Basilevsky, A.; Kaydash, V.; Ivanov, B.; Korokhin, V.; Videen, G.

    2018-02-01

    We use Kaguya MI images acquired at wavelengths 415, 750, and 950 nm to map TiO2 and FeO content and the parameter of optical maturity OMAT in lunar regions Lubiniezky E and Taurus-Littrow with a spatial resolution of 20 m using the Lucey method [Lucey et al., JGR 2000, 105. 20,297]. We show that some ejecta from large craters, such as Tycho and Copernicus may cause lunar surface erosion, transportation of the eroded material and its sedimentation. The traces of the erosion resemble wind tails observed on Earth, Mars, and Venus, although the Moon has no atmosphere. The highland material of the local topographic prominences could be mobilized by Tycho's granolometrically fine ejecta and caused by its transportation along the ejecta way to adjacent mare areas and subsequent deposition. The tails of mobilized material reveal lower abundances of Ti and Fe than the surrounding mare surface. We have concluded that high-Ti streaks also seen in the Lubiniezky E site, which show unusual combinations of the TiO2 and FeO content on the correlation diagram, could be the result of erosion by Tycho's ejecta too. In these locations, Tycho's material did not form a consolidated deposit, but resulted in erosion of the mare surface material that became intermixed, consequently, diluting the ejecta. The Taurus-Littrow did provide evidence of the mechanical effect of Tycho's ejecta on the local landforms (landslide, secondary craters) and do not show the compositional signature of Tycho's ejecta probably due to intermixing with local materials and dilution.

  7. Effect of impact angles on ejecta and crater shape of aluminum alloy 6061-T6 targets in hypervelocity impacts

    Directory of Open Access Journals (Sweden)

    Hayashi K.

    2012-08-01

    Full Text Available The effect of the impact angle of projectiles on the crater shape and ejecta in thick aluminum alloy targets was investigated in hypervelocity impacts. When polycarbonate projectiles and aluminum alloy 6061-T6 target were used, the impact angle of the projectiles clearly affected the crater shape, as expected. The impact angle also affected the ejecta mass, ejecta size and scatter angle. However, the effect at 15∘ and 22.5∘ was not great. When the impact angles were 30∘ and 45∘, the effect was clearly confirmed. The impact angle clearly affected the axial ratio of ejecta fragments, c/a.

  8. Evaporation Induced Oxygen Isotope Fractionation in Impact Ejecta

    Science.gov (United States)

    Macris, C. A.; Young, E. D.; Kohl, I. E.; zur Loye, T. E.

    2017-12-01

    Tektites are natural glasses formed as quenched impact melt ejecta. Because they experienced extreme heating while entrained in a hot impact vapor plume, tektites allow insight into the nature of these ephemeral events, which play a critical role in planetary accretion and evolution. During tektite formation, the chemical and isotopic composition of parent materials may be modified by (1) vapor/liquid fractionation at high T in the plume, (2) incorporation of meteoric water at the target site, (3) isotope exchange with atmospheric oxygen (if present), or some combination of the three. Trends from O isotope studies reveal a dichotomy: some tektite δ18O values are 4.0-4.5‰ lower than their protoliths (Luft et al. 1987; Taylor & Epstein 1962), opposite in direction to a vaporization induced fractionation; increases in δ18O with decreasing SiO2 in tektites (Taylor & Epstein 1969) is consistent with vapor fractionation. Using an aerodynamic levitation laser furnace (e.g. Macris et al. 2016), we can experimentally determine the contributions of processes (1), (2) and (3) above to tektite compositions. We conducted a series of evaporation experiments to test process (1) using powdered tektite fused into 2 mm spheres and heated to 2423-2473 K for 50-90 s while levitated in Ar in the furnace. Mass losses were from 23 to 26%, reflecting evaporation of Si and O from the melt. The starting tektite had a δ18O value of 10.06‰ (±0.01 2se) and the residues ranged from 13.136‰ (±0.006) for the least evaporated residue to 14.30‰ (±0.02) for the most evaporated (measured by laser fluorination). The increase in δ18O with increasing mass loss is consistent with Rayleigh fractionation during evaporation, supporting the idea that O isotopes are fractionated due to vaporization at high T in an impact plume. Because atmospheric O2 and water each have distinctive Δ17O values, we should be able to use departures from our measured three-isotope fractionation law to evaluate

  9. Exploring hotspots of pneumococcal pneumonia and potential impacts of ejecta dust exposure following the Christchurch earthquakes.

    Science.gov (United States)

    Pearson, Amber L; Kingham, Simon; Mitchell, Peter; Apparicio, Philippe

    2013-12-01

    The etiology of pneumococcal pneumonia (PP) is well-known. Yet, some events may increase its incidence. Natural disasters may worsen air quality, a risk factor for PP. We investigated spatial/spatio-temporal clustering of PP pre- and post-earthquakes in Christchurch, New Zealand. The earthquakes resulted in deaths, widespread damage and liquefaction ejecta (a source of air-borne dust). We tested for clusters and associations with ejecta, using 97 cases (diagnosed 10/2008-12/2011), adjusted for age and area-level deprivation. The strongest evidence to support the potential role of ejecta in clusters of PP cases was the: (1) geographic shift in the spatio-temporal cluster after deprivation adjustment to match the post-earthquake clusters and; (2) increased relative risk in the fully-adjusted post-earthquake compared to the pre-earthquake cluster. The application of spatial statistics to study PP and ejecta are novel. Further studies to assess the long-term impacts of ejecta inhalation are recommended particularly in Christchurch, where seismic activity continues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Spall strength and ejecta production of gold under explosively driven shock wave compression

    International Nuclear Information System (INIS)

    La Lone, B. M.; Stevens, G. D.; Turley, W. D.; Veeser, L. R.; Holtkamp, D. B.

    2013-01-01

    Explosively driven shock wave experiments were conducted to characterize the spall strength and ejecta production of high-purity cast gold samples. The samples were from 0.75 to 1.84 mm thick and 30 mm in diameter. Peak stresses up to 44 GPa in gold were generated using PBX-9501 high explosive. Sample free surface and ejecta velocities were recorded using photonic Doppler velocimetry techniques. Lithium niobate pins were used to quantify the time dependence of the ejecta density and the total ejected mass. An optical framing camera for time-resolved imaging and a single-image x-ray radiograph were used for additional characterization. Free surface velocities exhibited a range of spall strengths from 1.7 to 2.4 GPa (mean: 2.0 ±0.3 GPa). The pullback signals were faint, minimal ringing was observed in the velocity records, and the spall layer continued to decelerate after first pull back. These results suggest finite tensile strength was present for some time after the initial void formation. Ejecta were observed for every sample with a roughened free surface, and the ejecta density increased with increased surface roughness, which was different in every experiment. The total ejected mass is consistent with the missing mass model.

  11. The Three-dimensional Expansion of the Ejecta from Tycho's Supernova Remnant

    International Nuclear Information System (INIS)

    Williams, Brian J.; Depasquale, Joseph; Coyle, Nina M.; Yamaguchi, Hiroya; Petre, Robert; Seitenzahl, Ivo R.; Hewitt, John W.; Blondin, John M.; Borkowski, Kazimierz J.; Reynolds, Stephen P.; Ghavamian, Parviz

    2017-01-01

    We present the first 3D measurements of the velocity of various ejecta knots in Tycho’s supernova remnant, known to result from a Type Ia explosion. Chandra X-ray observations over a 12 yr baseline from 2003 to 2015 allow us to measure the proper motion of nearly 60 “tufts” of Si-rich ejecta, giving us the velocity in the plane of the sky. For the line-of-sight velocity, we use two different methods: a nonequilibrium ionization model fit to the strong Si and S lines in the 1.2–2.8 keV regime, and a fit consisting of a series of Gaussian lines. These methods give consistent results, allowing us to determine the redshift or blueshift of each of the knots. Assuming a distance of 3.5 kpc, we find total velocities that range from 2400 to 6600 km s −1 , with a mean of 4430 km s −1 . We find several regions where the ejecta knots have overtaken the forward shock. These regions have proper motions in excess of 6000 km s −1 . Some SN Ia explosion models predict a velocity asymmetry in the ejecta. We find no such velocity asymmetries in Tycho, and we discuss our findings in light of various explosion models, favoring those delayed-detonation models with relatively vigorous and symmetrical deflagrations. Finally, we compare measurements with models of the remnant’s evolution that include both smooth and clumpy ejecta profiles, finding that both ejecta profiles can be accommodated by the observations.

  12. The Three-Dimensional Expansion of the Ejecta from Tycho's Supernova Remnant

    Science.gov (United States)

    Williams, Brian J.; Coyle, Nina; Yamaguchi, Hiroya; DePasquale, Joseph M.; Seitenzahl, Ivo Rolf; Hewitt, John W.; Blondin, John M.; Borkowski, Kazimierz J.; Ghavamian, Parviz; Petre, Robert; Reynolds, Stephen P.

    2017-08-01

    We present the first three-dimensional measurements of the velocity of various ejecta knots in Tycho's supernova remnant, known to result from a Type Ia explosion. Chandra X-ray observations over a 12-year baseline from 2003 to 2015 allow us to measure the proper motion of nearly 60 ``tufts'' of Si-rich ejecta, giving us the velocity in the plane of the sky. For the line of sight velocity, we use two different methods: a non-equilibrium ionization model fit to the strong Si and S lines in the 1.2-2.8 keV regime, and a fit consisting of a series of Gaussian lines. These methods give consistent results, allowing us to determine the red or blue shift of each of the knots. Assuming a distance of 3.5 kpc, we find total velocities that range from 2400 to 6600 km s$^{-1}$, with a mean of 4430 km s$^{-1}$. We find several regions where the ejecta knots have overtaken the forward shock. These regions have proper motions in excess of 6000 km s$^{-1}$. Some Type Ia supernova explosion models predict a velocity asymmetry in the ejecta. We find no such velocity asymmetries in Tycho, and discuss our findings in light of various explosion models, favoring those delayed detonation models with relatively vigorous and symmetrical deflagrations. Finally, we compare measurements with models of the remnant's evolution that include both smooth and clumpy ejecta profiles, finding that both ejecta profiles can be accommodated by the observations.

  13. The Three-dimensional Expansion of the Ejecta from Tycho's Supernova Remnant

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brian J.; Depasquale, Joseph [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Coyle, Nina M.; Yamaguchi, Hiroya; Petre, Robert [NASA Goddard Space Flight Center, X-ray Astrophysics Laboratory, Greenbelt, MD 20771 (United States); Seitenzahl, Ivo R. [School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600 (Australia); Hewitt, John W. [University of North Florida, Department of Physics, 1 UNF Drive, Jacksonville, FL 32224 (United States); Blondin, John M.; Borkowski, Kazimierz J.; Reynolds, Stephen P. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Ghavamian, Parviz, E-mail: bwilliams@stsci.edu [Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD 21252 (United States)

    2017-06-10

    We present the first 3D measurements of the velocity of various ejecta knots in Tycho’s supernova remnant, known to result from a Type Ia explosion. Chandra X-ray observations over a 12 yr baseline from 2003 to 2015 allow us to measure the proper motion of nearly 60 “tufts” of Si-rich ejecta, giving us the velocity in the plane of the sky. For the line-of-sight velocity, we use two different methods: a nonequilibrium ionization model fit to the strong Si and S lines in the 1.2–2.8 keV regime, and a fit consisting of a series of Gaussian lines. These methods give consistent results, allowing us to determine the redshift or blueshift of each of the knots. Assuming a distance of 3.5 kpc, we find total velocities that range from 2400 to 6600 km s{sup −1}, with a mean of 4430 km s{sup −1}. We find several regions where the ejecta knots have overtaken the forward shock. These regions have proper motions in excess of 6000 km s{sup −1}. Some SN Ia explosion models predict a velocity asymmetry in the ejecta. We find no such velocity asymmetries in Tycho, and we discuss our findings in light of various explosion models, favoring those delayed-detonation models with relatively vigorous and symmetrical deflagrations. Finally, we compare measurements with models of the remnant’s evolution that include both smooth and clumpy ejecta profiles, finding that both ejecta profiles can be accommodated by the observations.

  14. THE CHEMISTRY OF POPULATION III SUPERNOVA EJECTA. I. FORMATION OF MOLECULES IN THE EARLY UNIVERSE

    International Nuclear Information System (INIS)

    Cherchneff, Isabelle; Dwek, Eli

    2009-01-01

    We study the formation and destruction of molecules in the ejecta of Population III supernovae (SNe) using a chemical kinetic approach to follow the evolution of molecular abundances from day 100 to day 1000 after explosion. The chemical species included in the study range from simple diatomic molecules to more complex dust precursor species. All relevant molecule formation and destruction processes that are unique to the SN environment are considered. Our work focuses on zero-metallicity progenitors with masses of 20, 170, and 270 M sun , and we study the effect of different levels of heavy element mixing and the inward diffusion of hydrogen and helium on the ejecta chemistry. We show that the ejecta chemistry does not reach a steady state within the relevant timespan (∼3 yr) for molecule formation, thus invalidating previous results relying on this assumption. The primary species formed in the harsh SN environment are O 2 , CO, SiS, and SO. The SiO, formed as early as 200 days after explosion, is rapidly depleted by the formation of silica molecular precursors in the ejecta. The rapid conversion of CO to C 2 and its thermal fractionation at temperatures above 5000 K allow for the formation of carbon chains in the oxygen-rich zone of the unmixed models, providing an important pathway for the formation of carbon dust in hot environments where the C/O ratio is less than 1. We show that the fully mixed ejecta of a 170 M sun progenitor synthesizes 11.3 M sun of molecules, whereas 20 M sun and 270 M sun progenitors produce 0.78 M sun and 3.2 M sun of molecules, respectively. The admixing of 10% of hydrogen into the fully mixed ejecta of the 170 M sun progenitor increases its molecular yield to ∼47 M sun . The unmixed ejecta of a 170 M sun progenitor SN without hydrogen penetration synthesizes ∼37 M sun of molecules, whereas its 20 M sun counterpart produces ∼1.2 M sun . This smaller efficiency at forming molecules is due to the large fraction of He + in the

  15. The origin of Phobos grooves from ejecta launched from impact craters on Mars: Tests of the hypothesis

    Science.gov (United States)

    Ramsley, Kenneth R.; Head, James W.

    2013-01-01

    The surface of the martian moon Phobos is characterized by parallel and intersecting grooves that bear resemblance to secondary crater chains observed on planetary surfaces. Murray (2011) has hypothesized that the main groove-forming process on Phobos is the intersection of Phobos with ejecta from primary impact events on Mars to produce chains of secondary craters. The hypothesis infers a pattern of parallel jets of ejecta, either fluidized or solidified, that break into equally-spaced fragments and disperse uniformly along-trajectory during the flight from Mars to Phobos. At the moment of impact with Phobos the dispersed fragments emplace secondary craters that are aligned along strike corresponding to the flight pattern of ejecta along trajectory. The aspects of the characteristics of grooves on Phobos cited by this hypothesis that might be explained by secondary ejecta include: their observed linearity, parallelism, planar alignment, pitted nature, change in character along strike, and a "zone of avoidance" where ejecta from Mars is predicted not to impact (Murray, 2011). To test the hypothesis we plot precise Keplerian orbits for ejecta from Mars (elliptical and hyperbolic with periapsis located below the surface of Mars). From these trajectories we: (1) set the fragment dispersion limits of ejecta patterns required to emplace the more typically well-organized parallel grooves observed in returned images from Phobos; (2) plot ranges of the ejecta flight durations from Mars to Phobos and map regions of exposure; (3) utilize the same exposure map to observe trajectory-defined ejecta exposure shadows; (4) observe hemispheric exposure in response to shorter and longer durations of ejecta flight; (5) assess the viability of ejecta emplacing the large family of grooves covering most of the northern hemisphere of Phobos; and (6) plot the arrival of parallel lines of ejecta emplacing chains of craters at oblique incident angles. We also assess the bulk volume of

  16. Ponds, Flows, and Ejecta of Impact Cratering and Volcanism: A Remote Sensing Perspective of a Dynamic Moon

    Science.gov (United States)

    Stopar, Julie D.

    Both volcanism and impact cratering produce ejecta and associated deposits incorporating a molten rock component. While the heat sources are different (exogenous vs. endogenous), the end results are landforms with similar morphologies including ponds and flows of impact melt and lava around the central crater. Ejecta from both impact and volcanic craters can also include a high percentage of melted rock. Using Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (LROC NAC) images, crucial details of these landforms are finally revealed, suggesting a much more dynamic Moon than is generally appreciated. Impact melt ponds and flows at craters as small as several hundred meters in diameter provide empirical evidence of abundant melting during the impact cratering process (much more than was previously thought), and this melt is mobile on the lunar surface for a significant time before solidifying. Enhanced melt deposit occurrences in the lunar highlands (compared to the mare) suggest that porosity, target composition, and pre-existing topography influence melt production and distribution. Comparatively deep impact craters formed in young melt deposits connote a relatively rapid evolution of materials on the lunar surface. On the other end of the spectrum, volcanic eruptions have produced the vast, plains-style mare basalts. However, little was previously known about the details of small-area eruptions and proximal volcanic deposits due to a lack of resolution. High-resolution images reveal key insights into small volcanic cones (0.5-3 km in diameter) that resemble terrestrial cinder cones. The cones comprise inter-layered materials, spatter deposits, and lava flow breaches. The widespread occurrence of the cones in most nearside mare suggests that basaltic eruptions occur from multiple sources in each basin and/or that rootless eruptions are relatively common. Morphologies of small-area volcanic deposits indicate diversity in eruption behavior of lunar basaltic

  17. Impact ejecta and carbonate sequence in the eastern sector of the Chicxulub crater

    Science.gov (United States)

    Urrutia-Fucugauchi, Jaime; Chavez-Aguirre, Jose Maria; Pérez-Cruz, Ligia; De la Rosa, Jose Luis

    2008-12-01

    The Chicxulub 200 km diameter crater located in the Yucatan platform of the Gulf of Mexico formed 65 Myr ago and has since been covered by Tertiary post-impact carbonates. The sediment cover and absence of significant volcanic and tectonic activity in the carbonate platform have protected the crater from erosion and deformation, making Chicxulub the only large multi-ring crater in which ejecta is well preserved. Ejecta deposits have been studied by drilling/coring in the southern crater sector and at outcrops in Belize, Quintana Roo and Campeche; little information is available from other sectors. Here, we report on the drilling/coring of a section of ˜34 m of carbonate breccias at 250 m depth in the Valladolid area (120 km away from crater center), which are interpreted as Chicxulub proximal ejecta deposits. The Valladolid breccias correlate with the carbonate breccias cored in the Peto and Tekax boreholes to the south and at similar radial distance. This constitutes the first report of breccias in the eastern sector close to the crater rim. Thickness of the Valladolid breccias is less than that at the other sites, which may indicate erosion of the ejecta deposits before reestablishment of carbonate deposition. The region east of the crater rim appears different from regions to the south and west, characterized by high density and scattered distribution of sinkholes.

  18. X-ray emission from reverse-shocked ejecta in supernova remnants

    Science.gov (United States)

    Cioffi, Denis F.; Mckee, Christopher F.

    1990-01-01

    A simple physical model of the dynamics of a young supernova remnant is used to derive a straightforward kinematical description of the reverse shock. With suitable approximations, formulae can then be developed to give the X-ray emission of the reverse-shocked ejecta. The results are found to agree favorably with observations of SN1006.

  19. Evolution of fluid-like granular ejecta generated by sphere impact

    KAUST Repository

    Marston, Jeremy; Li, Erqiang; Thoroddsen, Sigurdur T

    2012-01-01

    We present results from an experimental study of the speed and shape of the ejecta formed when a solid sphere impacts onto a granular bed. We use high-speed imaging at frame rates up to 100 000 f.p.s. to provide direct measurement of individual

  20. Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

    Science.gov (United States)

    Wu, Bao; Wu, FengChao; Zhu, YinBo; Wang, Pei; He, AnMin; Wu, HengAn

    2018-04-01

    Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD) simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

  1. Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

    Directory of Open Access Journals (Sweden)

    Bao Wu

    2018-04-01

    Full Text Available Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

  2. Properties of Kilonovae from Dynamical and Post-merger Ejecta of Neutron Star Mergers

    Science.gov (United States)

    Tanaka, Masaomi; Kato, Daiji; Gaigalas, Gediminas; Rynkun, Pavel; Radžiūtė, Laima; Wanajo, Shinya; Sekiguchi, Yuichiro; Nakamura, Nobuyuki; Tanuma, Hajime; Murakami, Izumi; Sakaue, Hiroyuki A.

    2018-01-01

    Ejected material from neutron star mergers gives rise to electromagnetic emission powered by radioactive decays of r-process nuclei, the so-called kilonova or macronova. While properties of the emission are largely affected by opacities in the ejected material, available atomic data for r-process elements are still limited. We perform atomic structure calculations for r-process elements: Se (Z = 34), Ru (Z = 44), Te (Z = 52), Ba (Z = 56), Nd (Z = 60), and Er (Z = 68). We confirm that the opacities from bound–bound transitions of open f-shell, lanthanide elements (Nd and Er) are higher than those of the other elements over a wide wavelength range. The opacities of open s-shell (Ba), p-shell (Se and Te), and d-shell (Ru) elements are lower than those of open f-shell elements, and their transitions are concentrated in the ultraviolet and optical wavelengths. We show that the optical brightness can be different by > 2 mag depending on the element abundances in the ejecta such that post-merger, lanthanide-free ejecta produce brighter and bluer optical emission. Such blue emission from post-merger ejecta can be observed from the polar directions if the mass of the preceding dynamical ejecta in these regions is small. For the ejecta mass of 0.01 {M}ȯ , observed magnitudes of the blue emission will reach 21.0 mag (100 Mpc) and 22.5 mag (200 Mpc) in the g and r bands within a few days after the merger, which are detectable with 1 m or 2 m class telescopes.

  3. Remote Sensing Observations and Numerical Simulation for Martian Layered Ejecta Craters

    Science.gov (United States)

    Li, L.; Yue, Z.; Zhang, C.; Li, D.

    2018-04-01

    To understand past Martian climates, it is important to know the distribution and nature of water ice on Mars. Impact craters are widely used ubiquitous indicators for the presence of subsurface water or ice on Mars. Remote sensing observations and numerical simulation are powerful tools for investigating morphological and topographic features on planetary surfaces, and we can use the morphology of layered ejecta craters and hydrocode modeling to constrain possible layering and impact environments. The approach of this work consists of three stages. Firstly, the morphological characteristics of the Martian layered ejecta craters are performed based on Martian images and DEM data. Secondly, numerical modeling layered ejecta are performed through the hydrocode iSALE (impact-SALE). We present hydrocode modeling of impacts onto targets with a single icy layer within an otherwise uniform basalt crust to quantify the effects of subsurface H2O on observable layered ejecta morphologies. The model setup is based on a layered target made up of a regolithic layer (described by the basalt ANEOS), on top an ice layer (described by ANEOS equation of H2O ice), in turn on top of an underlying basaltic crust. The bolide is a 0.8 km diameter basaltic asteroid hitting the Martian surface vertically at a velocity of 12.8 km/s. Finally, the numerical results are compared with the MOLA DEM profile in order to analyze the formation mechanism of Martian layered ejecta craters. Our simulations suggest that the presence of an icy layer significantly modifies the cratering mechanics, and many of the unusual features of SLE craters may be explained by the presence of icy layers. Impact cratering on icy satellites is significantly affected by the presence of subsurface H2O.

  4. THE MORPHOLOGY OF THE EJECTA IN SUPERNOVA 1987A: A STUDY OVER TIME AND WAVELENGTH

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Josefin [KTH, Department of Physics, and the Oskar Klein Centre, AlbaNova, SE-106 91 Stockholm (Sweden); Fransson, Claes; Lundqvist, Peter; Sollerman, Jesper [Department of Astronomy and the Oskar Klein Centre, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Kjaer, Karina; Leibundgut, Bruno; Spyromilio, Jason [ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Jerkstrand, Anders [Astrophysics Research Centre, School of Maths and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States); Mattila, Seppo [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland); McCray, Richard [JILA, University of Colorado, Boulder, CO 80309-0440 (United States); Wheeler, J. Craig [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States)

    2013-05-01

    We present a study of the morphology of the ejecta in Supernova 1987A based on images and spectra from the Hubble Space Telescope (HST) as well as integral field spectroscopy from VLT/SINFONI. The HST observations were obtained between 1994 and 2011 and primarily probe the outer H-rich zones of the ejecta. The SINFONI observations were obtained in 2005 and 2011 and instead probe the [Si I]+[Fe II] emission from the inner regions. We find a strong temporal evolution of the morphology in the HST images, from a roughly elliptical shape before {approx}5000 days, to a more irregular, edge-brightened morphology with a ''hole'' in the middle thereafter. This transition is a natural consequence of the change in the dominant energy source powering the ejecta, from radioactive decay before {approx}5000 days to X-ray input from the circumstellar interaction thereafter. The [Si I]+[Fe II] images display a more uniform morphology, which may be due to a remaining significant contribution from radioactivity in the inner ejecta and the higher abundance of these elements in the core. Both the H{alpha} and the [Si I]+[Fe II] line profiles show that the ejecta are distributed fairly close to the plane of the inner circumstellar ring, which is assumed to define the rotational axis of the progenitor star. The H{alpha} emission extends to higher velocities than [Si I]+[Fe II], as expected from theoretical models. There is no clear symmetry axis for all the emission. Instead, we find that the emission is concentrated to clumps and that the emission is distributed somewhat closer to the ring in the north than in the south. This north-south asymmetry may be partially explained by dust absorption. We compare our results with explosion models and find some qualitative agreement, but note that the observations show a higher degree of large-scale asymmetry.

  5. X-RAY EJECTA KINEMATICS OF THE GALACTIC CORE-COLLAPSE SUPERNOVA REMNANT G292.0+1.8

    Energy Technology Data Exchange (ETDEWEB)

    Bhalerao, Jayant; Park, Sangwook [Department of Physics, University of Texas at Arlington, P.O. Box 19059, Arlington, TX 76019 (United States); Dewey, Daniel [MIT Kavli Institute, Cambridge, MA 02139 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Mori, Koji [Department of Applied Physics, University of Miyazaki, 1-1 Gakuen Kibanadai-nishi, Miyazaki 889-2192 (Japan); Lee, Jae-Joon, E-mail: jayant.bhalerao@mavs.uta.edu [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)

    2015-02-10

    We report on the results from the analysis of our 114 ks Chandra High Energy Transmision Grating Spectrometer observation of the Galactic core-collapse supernova remnant G292.0+1.8. To probe the three-dimensional structure of the clumpy X-ray emitting ejecta material in this remnant, we measured Doppler shifts in emission lines from metal-rich ejecta knots projected at different radial distances from the expansion center. We estimate radial velocities of ejecta knots in the range of –2300 ≲ v{sub r}  ≲ 1400 km s{sup –1}. The distribution of ejecta knots in velocity versus projected-radius space suggests an expanding ejecta shell with a projected angular thickness of ∼90'' (corresponding to ∼3 pc at d = 6 kpc). Based on this geometrical distribution of the ejecta knots, we estimate the location of the reverse shock approximately at the distance of ∼4 pc from the center of the supernova remnant, putting it in close proximity to the outer boundary of the radio pulsar wind nebula. Based on our observed remnant dynamics and the standard explosion energy of 10{sup 51} erg, we estimate the total ejecta mass to be ≲8 M {sub ☉}, and we propose an upper limit of ≲35 M {sub ☉} on the progenitor's mass.

  6. Layered/Pancake-like Ejecta on Ceres: Inferring the Composition and Mechanical Properties of the Cerean Surface through Modeling of Ejecta Emplacement

    Science.gov (United States)

    Hughson, K.; Russell, C. T.; Schmidt, B. E.; Chilton, H.; Scully, J. E. C.; Sizemore, H. G.; Byrne, S.; Platz, T.; Raymond, C. A.

    2017-12-01

    During the Survey, High Altitude Mapping Orbit, and Low Altitude Mapping Orbit phases of the primary mission Dawn's Framing Camera observed a multitude of globally distributed lobate deposits. These flows were broadly interpreted as either similar to ice-cored/ice-cemented flows (Type 1 flows) on Earth and Mars, long run-out terrestrial or martian landslides (Type 2 flows), or highly mobile fluidized ejecta-like deposits (Type 3 flows) (Buczckowski et al., 2016; Schmidt et al., 2017). The Type 3 flows are morphologically similar to layered/pancake ejecta found on Mars and Ganymede where they are thought to be caused by impacts into ground ice rich substrates (Mouginis-Mark, 1979; Boyce et al., 2010). We assess the effects of target material strength, sliding friction, and vapor entrainment on the production of these features by comparing the ejecta mobility (EM: the ratio of the radius of the ejecta blanket to the radius of the parent crater) values for all Type 3 cerean flows to a ballistic/kinematic sliding model similar to the one developed by Weiss et al. (2014) to model EM for impacts into a variety of ground ice rich substrates of differing volatile content on Mars. Initial results suggest that, in order for these features to form, the cerean surface requires a large coefficient of sliding friction (>0.1), and that significant amounts of water be vaporized during impact. However, the model does not tightly constrain the strength of the target material (best-fit values range from granite-like to unconsolidated-sand-like). These results are consistent with a largely dry, rough, and thin surface layer underlain by material rich in pore-filling ground ice, even at low latitudes. Additionally, before the Fall Meeting we will attempt to constrain the thickness of the ice-poor surface layer. This will be done through a combined analysis of model results and morphometric parameters of individual Type 3 flows. Future implementation of this model will further

  7. Earth-based radar and LRO Diviner constraints on the recent rate of lunar ejecta processing

    Science.gov (United States)

    Ghent, Rebecca R.; Hayne, Paul O.; Bandfield, Joshua L.; Campbell, Bruce A.; Carter, Lynn M.; Allen, Carlton

    2013-04-01

    Many large craters on the lunar nearside show radar circular polarization ratio (CPR) signatures consistent with the presence of blocky ejecta blankets, to distances of 0.5 to 1.5 crater radii. However, most of these surfaces show very low surface rock concentration values and only limited enhancements in regolith temperatures calculated from Diviner nighttime infrared observations. Because the radar signal is integrated over the radar penetration depth (up to several meters), but the Diviner signal is sensitive only to rocks within the upper meter of the surface, this indicates that ejecta blocks on the surface and in the shallow subsurface are quickly removed by continued bombardment. Deeper subsurface rocks, which are clearly evident in radar CPR maps but are covered by a sufficiently thick layer of thermally insulating regolith material to render them invisible to Diviner, persist for much longer. By matching the results of one-dimensional thermal models to Diviner nighttime temperatures, we can constrain the thermophysical properties of the upper 1 meter of regolith. We find that Diviner nighttime cooling curves are best fit by a density profile that varies exponentially with depth, consistent with a mixture of rocks and regolith fines, with increasing rock content with depth. Using this density profile together with the surface rock abundance, we can estimate the excess rock mass represented by rocks on the surface and within the upper meter of regolith for individual craters. We find that for craters of known age younger than ~1.7Ga, a robust correlation exists between ejecta mass and crater age, which yields the first observational estimate of the rate of lunar ejecta processing. Our results show that crater ejecta are initially removed very quickly (perhaps up to ~1cm / m.y.), with the rate slowing over a short period of time to less than 1 mm / m.y., as the number of blocks on the surface decreases and the volume of protective regolith material increases

  8. Evolution of fluid-like granular ejecta generated by sphere impact

    KAUST Repository

    Marston, Jeremy

    2012-05-01

    We present results from an experimental study of the speed and shape of the ejecta formed when a solid sphere impacts onto a granular bed. We use high-speed imaging at frame rates up to 100 000 f.p.s. to provide direct measurement of individual grain velocities and ejecta angles as well as the overall evolution of the granular ejecta. For larger grain sizes, the emergence velocities of the grains during the early stage flow, i.e. before the main ejecta curtain forms, increase with the kinetic energy of the impacting sphere but are inversely proportional to the time from impact. We also observe that the fastest grains, which can obtain velocities up to five times that of the impacting sphere (V g/V 0 = 5), generally emerge at the earliest times and with the lowest ejection angles. As the grain size is decreased, a more fluid-like behaviour is observed whereby the ejected material first emerges as a thin sheet of grains between the sphere and the bed surface, which is also seen when a sphere impacts a liquid pool. In this case, the sheet velocity is approximately double that of the impacting sphere (V s/V 0 = 2) and independent of the bulk packing fraction. For the finest grains we provide evidence of the existence of a vortex ring inside the ejecta curtain where grains following the air flow are entrained through the curtain. In contrast to predictions from previous studies, we find that the temporal evolution of the ejecta neck radius is not initially quadratic but rather approaches a square-root dependence on time, for the finest grains with the highest impact kinetic energy. The evolution therefore approaches that seen for the crown evolution in liquid drop impacts. By using both spherical glass beads and coarse sands, we show that the size and shape distribution are critical in determining the post-impact dynamics whereby the sands exhibit a qualitatively different response to impact, with grains ejected at lower speeds and at later times than for the glass

  9. Origin of the outer layer of martian low-aspect ratio layered ejecta craters

    Science.gov (United States)

    Boyce, Joseph M.; Wilson, Lionel; Barlow, Nadine G.

    2015-01-01

    Low-aspect ratio layered ejecta (LARLE) craters are one of the most enigmatic types of martian layered ejecta craters. We propose that the extensive outer layer of these craters is produced through the same base surge mechanism as that which produced the base surge deposits generated by near-surface, buried nuclear and high-explosive detonations. However, the LARLE layers have higher aspect ratios compared with base surge deposits from explosion craters, a result of differences in thicknesses of these layers. This characteristics is probably caused by the addition of large amounts of small particles of dust and ice derived from climate-related mantles of snow, ice and dust in the areas where LARLE craters form. These deposits are likely to be quickly stabilized (order of a few days to a few years) from eolian erosion by formation of duricrust produced by diffusion of water vapor out of the deposits.

  10. Formation of dust grains in the ejecta of SN 1987A

    International Nuclear Information System (INIS)

    Kozasa, Takashi; Hasegawa, Hiroichi; Nomoto, Kenichi

    1989-01-01

    Formation of dust grains in the ejecta of SN 1987A is investigated on the basis of a theory of homogeneous nucleation and grain growth. The formation of dust grains in the gas ejected from a heavy element-rich mantle is considered, including the effects of latent heat released during grain growth and of radiation from the photosphere. It is shown that dust grains can condense in the heavy-element-rich mantle, and that the time of formation strongly depends on the temperature structure in the ejecta. Moreover, the formation of dust grains is retarded by the strong SN radiation field and the effect of latent heat deposited during grain growth. 41 refs

  11. The 3D morphology of the ejecta surrounding VY Canis Majoris

    Science.gov (United States)

    Jones, Terry Jay; Humphreys, Roberta M.; Helton, L. Andrew

    2007-03-01

    We use second epoch images taken with WFPC2 on the HST and imaging polarimetry taken with the HST/ACS/HRC to explore the three dimensional structure of the circumstellar dust distribution around the red supergiant VY Canis Majoris. Transverse motions, combined with radial velocities, provide a picture of the kinematics of the ejecta, including the total space motions. The fractional polarization and photometric colors provide an independent method of locating the physical position of the dust along the line-of-sight. Most of the individual arc-like features and clumps seen in the intensity image are also features in the fractional polarization map, and must be distinct geometric objects. The location of these features in the ejecta of VY CMa using kinematics and polarimetry agree well with each other, and strongly suggest they are the result of relatively massive ejections, probably associated with magnetic fields.

  12. A simple technique to determine the size distribution of nuclear crater fallback and ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, II, Brooks D [U.S. Army Engineer Nuclear Cratering Group, Lawrence Radiation Laboratory, Livermore, CA (United States)

    1970-05-15

    This report describes the results of an investigation to find an economic method for determining the block size distribution of nuclear crater fallback and ejecta. It is shown that the modal analysis method of determining relative proportions can be applied with the use of a special sampling technique, to provide a size distribution curve for clastic materials similar to one obtainable by sieving and weighing the same materials.

  13. Impact of ejecta morphology and composition on the electromagnetic signatures of neutron star mergers

    Science.gov (United States)

    Wollaeger, Ryan T.; Korobkin, Oleg; Fontes, Christopher J.; Rosswog, Stephan K.; Even, Wesley P.; Fryer, Christopher L.; Sollerman, Jesper; Hungerford, Aimee L.; van Rossum, Daniel R.; Wollaber, Allan B.

    2018-04-01

    The electromagnetic transients accompanying compact binary mergers (γ-ray bursts, afterglows and 'macronovae') are crucial to pinpoint the sky location of gravitational wave sources. Macronovae are caused by the radioactivity from freshly synthesised heavy elements, e.g. from dynamic ejecta and various types of winds. We study macronova signatures by using multi-dimensional radiative transfer calculations. We employ the radiative transfer code SuperNu and state-of-the art LTE opacities for a few representative elements from the wind and dynamical ejecta (Cr, Pd, Se, Te, Br, Zr, Sm, Ce, Nd, U) to calculate synthetic light curves and spectra for a range of ejecta morphologies. The radioactive power of the resulting macronova is calculated with the detailed input of decay products. We assess the detection prospects for our most complex models, based on the portion of viewing angles that are sufficiently bright, at different cosmological redshifts (z). The brighter emission from the wind is unobscured by the lanthanides (or actinides) in some of the models, permitting non-zero detection probabilities for redshifts up to z = 0.07. We also find the nuclear mass model and the resulting radioactive heating rate are crucial for the detectability. While for the most pessimistic heating rate (from the FRDM model) no reasonable increase in the ejecta mass or velocity, or wind mass or velocity, can possibly make the light curves agree with the observed nIR excess after GRB130603B, a more optimistic heating rate (from the Duflo-Zuker model) leads to good agreement. We conclude that future reliable macronova observations would constrain nuclear heating rates, and consequently help constrain nuclear mass models.

  14. Shock Acceleration of Electrons and Synchrotron Emission from the Dynamical Ejecta of Neutron Star Mergers

    Science.gov (United States)

    Lee, Shiu-Hang; Maeda, Keiichi; Kawanaka, Norita

    2018-05-01

    Neutron star mergers (NSMs) eject energetic subrelativistic dynamical ejecta into circumbinary media. Analogous to supernovae and supernova remnants, the NSM dynamical ejecta are expected to produce nonthermal emission by electrons accelerated at a shock wave. In this paper, we present the expected radio and X-ray signals by this mechanism, taking into account nonlinear diffusive shock acceleration (DSA) and magnetic field amplification. We suggest that the NSM is unique as a DSA site, where the seed relativistic electrons are abundantly provided by the decays of r-process elements. The signal is predicted to peak at a few 100–1000 days after the merger, determined by the balance between the decrease of the number of seed electrons and the increase of the dissipated kinetic energy, due to the shock expansion. While the resulting flux can ideally reach the maximum flux expected from near-equipartition, the available kinetic energy dissipation rate of the NSM ejecta limits the detectability of such a signal. It is likely that the radio and X-ray emission are overwhelmed by other mechanisms (e.g., an off-axis jet) for an observer placed in a jet direction (i.e., for GW170817). However, for an off-axis observer, to be discovered once a number of NSMs are identified, the dynamical ejecta component is predicted to dominate the nonthermal emission. While the detection of this signal is challenging even with near-future facilities, this potentially provides a robust probe of the creation of r-process elements in NSMs.

  15. Sesquinary Catenae on the Martian Satellite Phobos from Reaccretion of Escaping Ejecta

    Science.gov (United States)

    2016-08-30

    Form 298 (Rev . 8/98) PrescribM by ANSI Std Z39 18 Adobe Professional 7 .0 ARTICLE Received 25 Nov 2015 | Accepted 14 Jul 2016 | Published 30 Aug...Phobos’ current orbit (o50Ma). Figure 4 illustrates how orbital ejecta lingering in the vicinity of the Phobos orbit can be swallowed up in hemispherical... illustrating how hemispherical catena (Fig. 5) may be formed. NATURE COMMUNICATIONS | DOI: 10.1038/ncomms12591 ARTICLE NATURE COMMUNICATIONS | 7

  16. A simple technique to determine the size distribution of nuclear crater fallback and ejecta

    International Nuclear Information System (INIS)

    Anderson, Brooks D. II

    1970-01-01

    This report describes the results of an investigation to find an economic method for determining the block size distribution of nuclear crater fallback and ejecta. It is shown that the modal analysis method of determining relative proportions can be applied with the use of a special sampling technique, to provide a size distribution curve for clastic materials similar to one obtainable by sieving and weighing the same materials

  17. Three-dimensional simulations of the interaction between the nova ejecta, accretion disk, and companion star

    Science.gov (United States)

    Figueira, Joana; José, Jordi; García-Berro, Enrique; Campbell, Simon W.; García-Senz, Domingo; Mohamed, Shazrene

    2018-05-01

    Context. Classical novae are thermonuclear explosions hosted by accreting white dwarfs in stellar binary systems. Material piles up on top of the white dwarf star under mildly degenerate conditions, driving a thermonuclear runaway. The energy released by the suite of nuclear processes operating at the envelope, mostly proton-capture reactions and β+-decays, heats the material up to peak temperatures ranging from 100 to 400 MK. In these events, about 10-3-10-7 M⊙, enriched in CNO and, sometimes, other intermediate-mass elements (e.g., Ne, Na, Mg, and Al) are ejected into the interstellar medium. Aims: To date, most of the efforts undertaken in the modeling of classical nova outbursts have focused on the early stages of the explosion and ejection, ignoring the interaction of the ejecta, first with the accretion disk orbiting the white dwarf and ultimately with the secondary star. Methods: A suite of 3D, smoothed-particle hydrodynamics (SPH) simulations of the interaction between the nova ejecta, accretion disk, and stellar companion were performed to fill this gap; these simulations were aimed at testing the influence of the model parameters—that is, the mass and velocity of the ejecta, mass and the geometry of the accretion disk—on the dynamical and chemical properties of the system. Results: We discuss the conditions that lead to the disruption of the accretion disk and to mass loss from the binary system. In addition, we discuss the likelihood of chemical contamination of the stellar secondary induced by the impact with the nova ejecta and its potential effect on the next nova cycle. Movies showing the full evolution of several models are available online at http://https://www.aanda.org and at http://www.fen.upc.edu/users/jjose/Downloads.html

  18. Ground penetrating radar geologic field studies of the ejecta of Barringer Meteorite Crater, Arizona, as a planetary analog

    Science.gov (United States)

    Russell, Patrick S.; Grant, John A.; Williams, Kevin K.; Carter, Lynn M.; Brent Garry, W.; Daubar, Ingrid J.

    2013-09-01

    penetrating radar (GPR) has been a useful geophysical tool in investigating a variety of shallow subsurface geological environments on Earth. Here we investigate the capabilities of GPR to provide useful geologic information in one of the most common geologic settings of planetary surfaces, impact crater ejecta. Three types of ejecta are surveyed with GPR at two wavelengths (400 MHz, 200 MHz) at Meteor Crater, Arizona, with the goal of capturing the GPR signature of the subsurface rock population. In order to "ground truth" the GPR characterization, subsurface rocks are visually counted and measured in preexisting subsurface exposures immediately adjacent to and below the GPR transect. The rock size-frequency distribution from 10 to 50 cm based on visual counts is well described by both power law and exponential functions, the former slightly better, reflecting the control of fragmentation processes during the impact-ejection event. GPR counts are found to overestimate the number of subsurface rocks in the upper meter (by a factor of 2-3x) and underestimate in the second meter of depth (0.6-1.0x), results attributable to the highly scattering nature of blocky ejecta. Overturned ejecta that is fractured yet in which fragments are minimally displaced from their complement fragments produces fewer GPR returns than well-mixed ejecta. The use of two wavelengths and division of results into multiple depth zones provides multiple aspects by which to characterize the ejecta block population. Remote GPR measurement of subsurface ejecta in future planetary situations with no subsurface exposure can be used to characterize those rock populations relative to that of Meteor Crater.

  19. External Shock in a Multi-bursting Gamma-Ray Burst: Energy Injection Phase Induced by the Later Launched Ejecta

    Science.gov (United States)

    Lin, Da-Bin; Huang, Bao-Quan; Liu, Tong; Gu, Wei-Min; Mu, Hui-Jun; Liang, En-Wei

    2018-01-01

    Central engines of gamma-ray bursts (GRBs) may be intermittent and launch several episodes of ejecta separated by a long quiescent interval. In this scenario, an external shock is formed due to the propagation of the first launched ejecta into the circum-burst medium and the later launched ejecta may interact with the external shock at a later period. Owing to the internal dissipation, the later launched ejecta may be observed at a later time (t jet). In this paper, we study the relation of t b and t jet, where t b is the collision time of the later launched ejecta with the formed external shock. It is found that the relation of t b and t jet depends on the bulk Lorentz factor (Γjet) of the later launched ejecta and the density (ρ) of the circum-burst medium. If the value of Γjet or ρ is low, the t b would be significantly larger than t jet. However, the t b ∼ t jet can be found if the value of Γjet or ρ is significantly large. Our results can explain the large lag of the optical emission relative to the γ-ray/X-ray emission in GRBs, e.g., GRB 111209A. For GRBs with a precursor, our results suggest that the energy injection into the external shock and thus more than one external-reverse shock may appear in the main prompt emission phase. According to our model, we estimate the Lorentz factor of the second launched ejecta in GRB 160625B.

  20. HCN Production via Impact Ejecta Reentry During the Late Heavy Bombardment

    Science.gov (United States)

    Parkos, Devon; Pikus, Aaron; Alexeenko, Alina; Melosh, H. Jay

    2018-04-01

    Major impact events have shaped the Earth as we know it. The Late Heavy Bombardment is of particular interest because it immediately precedes the first evidence of life. The reentry of impact ejecta creates numerous chemical by-products, including biotic precursors such as HCN. This work examines the production of HCN during the Late Heavy Bombardment in more detail. We stochastically simulate the range of impacts on the early Earth and use models developed from existing studies to predict the corresponding ejecta properties. Using multiphase flow methods and finite-rate equilibrium chemistry, we then find the HCN production due to the resulting atmospheric heating. We use Direct Simulation Monte Carlo to develop a correction factor to account for increased yields due to thermochemical nonequilibrium. We then model 1-D atmospheric turbulent diffusion to find the time accurate transport of HCN to lower altitudes and ultimately surface water. Existing works estimate the necessary HCN molarity threshold to promote polymerization that is 0.01 M. For a mixing depth of 100 m, we find that the Late Heavy Bombardment will produce at least one impact event above this threshold with probability 24.1% for an oxidized atmosphere and 56.3% for a partially reduced atmosphere. For a mixing depth of 10 m, the probability is 79.5% for an oxidized atmosphere and 96.9% for a partially reduced atmosphere. Therefore, Late Heavy Bombardment impact ejecta is likely an HCN source sufficient for polymerization in shallow bodies of water, particularly if the atmosphere were in a partially reduced state.

  1. Transfer of impact ejecta material from the surface of Mars to Phobos and Deimos.

    Science.gov (United States)

    Chappaz, Loïc; Melosh, Henry J; Vaquero, Mar; Howell, Kathleen C

    2013-10-01

    The Russian Phobos-Grunt spacecraft originally planned to return a 200 g sample of surface material from Phobos to Earth. Although it was anticipated that this material would mainly be from the body of Phobos, there is a possibility that such a sample may also contain material ejected from the surface of Mars by large impacts. An analysis of this possibility is completed by using current knowledge of aspects of impact cratering on the surface of Mars and the production of high-speed ejecta that might reach Phobos or Deimos.

  2. Global and local re-impact and velocity regime of ballistic ejecta of boulder craters on Ceres

    Science.gov (United States)

    Schulzeck, F.; Schröder, S. E.; Schmedemann, N.; Stephan, K.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2018-04-01

    Imaging by the Dawn-spacecraft reveals that fresh craters on Ceres below 40 km often exhibit numerous boulders. We investigate how the fast rotating, low-gravity regime on Ceres influences their deposition. We analyze size-frequency distributions of ejecta blocks of twelve boulder craters. Global and local landing sites of boulder crater ejecta and boulder velocities are determined by the analytical calculation of elliptic particle trajectories on a rotating body. The cumulative distributions of boulder diameters follow steep-sloped power-laws. We do not find a correlation between boulder size and the distance of a boulder to its primary crater. Due to Ceres' low gravitational acceleration and fast rotation, ejecta of analyzed boulder craters (8-31 km) can be deposited across the entire surface of the dwarf planet. The particle trajectories are strongly influenced by the Coriolis effect as well as the impact geometry. Fast ejecta of high-latitude craters accumulate close to the pole of the opposite hemisphere. Fast ejecta of low-latitude craters wraps around the equator. Rotational effects are also relevant for the low-velocity regime. Boulders are ejected at velocities up to 71 m/s.

  3. Properties of Neutrino-driven Ejecta from the Remnant of a Binary Neutron Star Merger: Pure Radiation Hydrodynamics Case

    Energy Technology Data Exchange (ETDEWEB)

    Fujibayashi, Sho [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Sekiguchi, Yuichiro [Department of Physics, Toho University, Funabashi, Chiba 274-8510 (Japan); Kiuchi, Kenta; Shibata, Masaru, E-mail: sho.fujibayashi@yukawa.kyoto-u.ac.jp [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2017-09-10

    We performed general relativistic, long-term, axisymmetric neutrino radiation hydrodynamics simulations for the remnant formed after a binary neutron star merger, which consists of a massive neutron star and a torus surrounding it. As an initial condition, we employ the result derived in a three-dimensional, numerical relativity simulation for the binary neutron star merger. We investigate the properties of neutrino-driven ejecta. Due to the pair-annihilation heating, the dynamics of the neutrino-driven ejecta are significantly modified. The kinetic energy of the ejecta is about two times larger than that in the absence of pair-annihilation heating. This suggests that the pair-annihilation heating plays an important role in the evolution of merger remnants. The relativistic outflow, which is required for driving gamma-ray bursts, is not observed because the specific heating rate around the rotational axis is not sufficiently high, due to the baryon loading caused by the neutrino-driven ejecta from the massive neutron star. We discuss the condition for launching the relativistic outflow and the nucleosynthesis in the ejecta.

  4. Mineral-produced high-pressure striae and clay polish: Key evidence for nonballistic transport of ejecta from Ries crater

    Science.gov (United States)

    Chao, E.C.T.

    1976-01-01

    Recently discovered mineral-produced, deeply incised striae and mirror-like polish on broken surfaces of limestone fragments from the sedimentary ejecta of the Ries impact crater of southern Germany are described. The striae and polish were produced under high confining pressures during high-velocity nonballistic transport of the ejecta mass within the time span of the cratering event (measured in terms of seconds). The striae on these fragments were produced by scouring by small mineral grains embedded in the surrounding clay matrix, and the polish was formed under the same condition, by movements of relatively fragment-free clay against the fragment surfaces. The occurrence of these striae and polish is key evidence for estimating the distribution and determining the relative importance of nonballistic and ballistic transport of ejecta from the shallow Ries stony meteorite impact crater.

  5. Characteristics of ejecta and alluvial deposits at Meteor Crater, Arizona and Odessa Craters, Texas: Results from ground penetrating radar

    Science.gov (United States)

    Grant, J. A.; Schultz, P. H.

    1991-01-01

    Previous ground penetrating radar (GRP) studies around 50,000 year old Meteor Crater revealed the potential for rapid, inexpensive, and non-destructive sub-surface investigations for deep reflectors (generally greater than 10 m). New GRP results are summarized focusing the shallow sub-surfaces (1-2 m) around Meteor Crater and the main crater at Odessa. The following subject areas are covered: (1) the thickness, distribution, and nature of the contact between surrounding alluvial deposits and distal ejecta; and (2) stratigraphic relationships between both the ejecta and alluvium derived from both pre and post crater drainages. These results support previous conclusions indicating limited vertical lowering (less than 1 m) of the distal ejecta at Meteor Crater and allow initial assessment of the gradational state if the Odessa craters.

  6. The effect of ambient pressure on ejecta sheets from free-surface ablation

    KAUST Repository

    Marston, J. O.; Mansoor, Mohammad M.; Thoroddsen, Sigurdur T; Truscott, T. T.

    2016-01-01

    We present observations from an experimental study of the ablation of a free liquid surface promoted by a focused laser pulse, causing a rapid discharge of liquid in the form of a very thin conical-shaped sheet. In order to capture the dynamics, we employ a state-of-the-art ultra-high-speed video camera capable of capturing events at (Formula presented.) fps with shutter speeds down to 20 ns, whereby we were able to capture not only the ejecta sheet, but also the shock wave, emerging at speeds of up to 1.75 km/s, which is thus found to be hypersonic (Mach 5). Experiments were performed at a range of ambient pressures in order to study the effect of air drag on the evolution of the sheet, which was always observed to dome over, even at pressures as low as 3.8 kPa. At reduced pressures, the extended sheet evolution led to the formation of interference fringe patterns from which, by comparison with the opening speed of rupture, we were able to determine the ejecta thickness. © 2016, Springer-Verlag Berlin Heidelberg.

  7. 14C ages for the ejecta from Kutcharo and Mashu calderas, eastern Hokkaido, Japan

    International Nuclear Information System (INIS)

    Yamamoto, Takahiro; Ito, Jun-ichi; Nakagawa, Mitsuhiro; Hasegawa, Takeshi; Kishimoto, Hiroshi

    2010-01-01

    Eruption ages of the ejecta from Kutcharo and Mashu calderas were systematically determined by 14 C dating. 16 charred samples were newly obtained from the Mashu and Nakashumbetsu Tephra Formations around the calderas and dated by AMS and β-counting methods. Examined units are Ma-d, Ma-e, Ma-f, Ma-j, Ma-k, Ma-l and Ml-a in the Mashu ejecta and 6 Nakashumbetsu tephra layers including Kutcharo Pumice Flow Deposit I (KpI), which is the youngest caldera-forming product from Kutcharo caldera. Results of the 14 C dating range from 3,660 ±40 yBP to 36,080±1,300 yBP, and are consistent with the tephrostratigraphy. Calendar age for KpI was newly calculated at almost 40 ka and this age shows there was about 70,000 years recurrence interval between KpI and KpIV caldera-forming eruptions. Mashu caldera has appeared on the eastern part of Kutcharo caldera immediately after the KpI eruption, and calendar age for its main caldera-forming eruption were determined at ca. BC 5,600. (author)

  8. The Three-Dimensional Morphology of VY Canis Majoris. I. The Kinematics of the Ejecta

    Science.gov (United States)

    Humphreys, Roberta M.; Helton, L. Andrew; Jones, Terry J.

    2007-06-01

    Images of the complex circumstellar nebula associated with the famous red supergiant VY CMa show evidence for multiple and asymmetric mass-loss events over the past 1000 yr. Doppler velocities of the arcs and knots in the ejecta show that they are not only spatially distinct but also kinematically separate from the surrounding diffuse material. In this paper we describe second-epoch HST WFPC2 images to measure the transverse motions, which when combined with the radial motions provide a complete picture of the kinematics of the ejecta, including the total space motions and directions of the outflows. Our results show that the arcs and clumps of knots are moving at different velocities, in different directions, and at different angles relative to the plane of the sky and to the star, confirming their origin from eruptions at different times and from physically separate regions on the star. We conclude that the morphology and kinematics of the arcs and knots are consistent with a history of mass ejections not aligned with any presumed axis of symmetry. The arcs and clumps represent relatively massive outflows and ejections of gas very likely associated with large-scale convective activity and magnetic fields. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  9. The effect of ambient pressure on ejecta sheets from free-surface ablation

    KAUST Repository

    Marston, J. O.

    2016-04-16

    We present observations from an experimental study of the ablation of a free liquid surface promoted by a focused laser pulse, causing a rapid discharge of liquid in the form of a very thin conical-shaped sheet. In order to capture the dynamics, we employ a state-of-the-art ultra-high-speed video camera capable of capturing events at (Formula presented.) fps with shutter speeds down to 20 ns, whereby we were able to capture not only the ejecta sheet, but also the shock wave, emerging at speeds of up to 1.75 km/s, which is thus found to be hypersonic (Mach 5). Experiments were performed at a range of ambient pressures in order to study the effect of air drag on the evolution of the sheet, which was always observed to dome over, even at pressures as low as 3.8 kPa. At reduced pressures, the extended sheet evolution led to the formation of interference fringe patterns from which, by comparison with the opening speed of rupture, we were able to determine the ejecta thickness. © 2016, Springer-Verlag Berlin Heidelberg.

  10. Freely Expanding Knots of X-Ray-emitting Ejecta in Kepler’s Supernova Remnant

    Science.gov (United States)

    Sato, Toshiki; Hughes, John P.

    2017-08-01

    We report measurements of proper motion, radial velocity, and elemental composition for 14 compact X-ray-bright knots in Kepler’s supernova remnant (SNR) using archival Chandra data. The knots with the highest speed show both large proper motions (μ ˜ 0.″11-0.″14 yr-1) and high radial velocities (v ˜ 8700-10,020 km s-1). For these knots the estimated space velocities (9100 km s-1 ≲ v 3D ≲ 10,400 km s-1) are similar to the typical Si velocity seen in supernovae (SNe) Ia near maximum light. High-speed ejecta knots appear only in specific locations and are morphologically and kinematically distinct from the rest of the ejecta. The proper motions of five knots extrapolate back over the age of Kepler’s SNR to a consistent central position. This new kinematic center agrees well with previous determinations, but is less subject to systematic errors and denotes a location about which several prominent structures in the remnant display a high degree of symmetry. These five knots are expanding at close to the free expansion rate (expansion indices of 0.75 ≲ m ≲ 1.0), which we argue indicates either that they were formed in the explosion with a high density contrast (more than 100 times the ambient density) or that they have propagated through regions of relatively low density (n H ruled out.

  11. Ejecta cloud from the AIDA space project kinetic impact on the secondary of a binary asteroid: I. mechanical environment and dynamical model

    Science.gov (United States)

    Yu, Yang; Michel, Patrick; Schwartz, Stephen R.; Naidu, Shantanu P.; Benner, Lance A. M.

    2017-01-01

    An understanding of the post-impact dynamics of ejecta clouds are crucial to the planning of a kinetic impact mission to an asteroid, and also has great implications for the history of planetary formation. The purpose of this article is to track the evolution of ejecta produced by AIDA mission, which targets for kinetic impact the secondary of near-Earth binary asteroid (65803) Didymos on 2022, and to feedback essential informations to AIDA's ongoing phase-A study. We present a detailed dynamic model for the simulation of an ejecta cloud from a binary asteroid that synthesizes all relevant forces based on a previous analysis of the mechanical environment. We apply our method to gain insight into the expected response of Didymos to the AIDA impact, including the subsequent evolution of debris and dust. The crater scaling relations from laboratory experiments are employed to approximate the distributions of ejecta mass and launching speed. The size distribution of fragments is modeled with a power law fitted from observations of real asteroid surface. A full-scale demonstration is simulated using parameters specified by the mission. We report the results of the simulation, which include the computed spread of the ejecta cloud and the recorded history of ejecta accretion and escape. The violent period of the ejecta evolution is found to be short, and is followed by a stage where the remaining ejecta is gradually cleared. Solar radiation pressure proves to be efficient in cleaning dust-size ejecta, and the simulation results after two weeks shows that large debris on polar orbits (perpendicular to the binary orbital plane) has a survival advantage over smaller ejecta and ejecta that keeps to low latitudes.

  12. (U) Physics Validation of the RMI-Based Ejecta Source Model Implementation in FLAG: L2 Milestone #6035 Report

    Energy Technology Data Exchange (ETDEWEB)

    Tregillis, I. L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-14

    The Los Alamos Physics and Engineering Models (PEM) program has developed a model for Richtmyer-Meshkov instability (RMI) based ejecta production from shock-melted surfaces, along with a prescription for a self-similar velocity distribution (SSVD) of the resulting ejecta particles. We have undertaken an effort to validate this source model using data from explosively driven tin coupon experiments. The model’s current formulation lacks a crucial piece of physics: a method for determining the duration of the ejecta production interval. Without a mechanism for terminating ejecta production, the model is not predictive. Furthermore, when the production interval is hand-tuned to match time-integrated mass data, the predicted time-dependent mass accumulation on a downstream sensor rises too sharply at early times and too slowly at late times because the SSVD overestimates the amount of mass stored in the fastest particles and underestimates the mass stored in the slowest particles. The functional form of the resulting m(t) is inconsistent with the available time-dependent data; numerical simulations and analytic studies agree on this point. Simulated mass tallies are highly sensitive to radial expansion of the ejecta cloud. It is not clear if the same effect is present in the experimental data but if so, depending on the degree, this may challenge the model’s compatibility with tin coupon data. The current implementation of the model in FLAG is sensitive to the detailed interaction between kinematics (hydrodynamic methods) and thermodynamics (material models); this sensitivity prohibits certain physics modeling choices. The appendices contain an extensive analytic study of piezoelectric ejecta mass measurements, along with test problems, excerpted from a longer work (LA-UR-17-21218).

  13. Freely Expanding Knots of X-Ray-emitting Ejecta in Kepler’s Supernova Remnant

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Toshiki [Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Hughes, John P., E-mail: toshiki@astro.isas.jaxa.jp, E-mail: jph@physics.rutgers.edu [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States)

    2017-08-20

    We report measurements of proper motion, radial velocity, and elemental composition for 14 compact X-ray-bright knots in Kepler’s supernova remnant (SNR) using archival Chandra data. The knots with the highest speed show both large proper motions ( μ ∼ 0.″11–0.″14 yr{sup −1}) and high radial velocities ( v ∼ 8700–10,020 km s{sup −1}). For these knots the estimated space velocities (9100 km s{sup −1} ≲ v {sub 3D} ≲ 10,400 km s{sup −1}) are similar to the typical Si velocity seen in supernovae (SNe) Ia near maximum light. High-speed ejecta knots appear only in specific locations and are morphologically and kinematically distinct from the rest of the ejecta. The proper motions of five knots extrapolate back over the age of Kepler’s SNR to a consistent central position. This new kinematic center agrees well with previous determinations, but is less subject to systematic errors and denotes a location about which several prominent structures in the remnant display a high degree of symmetry. These five knots are expanding at close to the free expansion rate (expansion indices of 0.75 ≲ m ≲ 1.0), which we argue indicates either that they were formed in the explosion with a high density contrast (more than 100 times the ambient density) or that they have propagated through regions of relatively low density ( n {sub H} < 0.1 cm{sup −3}) in the ambient medium. X-ray spectral analysis shows that the undecelerated knots have high Si and S abundances, a lower Fe abundance, and very low O abundance, pointing to an origin in the partial Si-burning zone, which occurs in the outer layer of the exploding white dwarf for models of SNe Ia. Other knots show lower speeds and expansion indices consistent with decelerated ejecta knots or features in the ambient medium overrun by the forward shock. Our new accurate location for the explosion site has well-defined positional uncertainties, allowing for a great reduction in the area to be searched for faint

  14. The rebirth of Supernova 1987A : a study of the ejecta-ring collision

    Science.gov (United States)

    Gröningsson, Per

    Supernovae are some of the most energetic phenomena in the Universe and they have throughout history fascinated people as they appeared as new stars in the sky. Supernova (SN) 1987A exploded in the nearby satellite galaxy, the Large Magellanic Cloud (LMC), at a distance of only 168,000 light years. The proximity of SN 1987A offers a unique opportunity to study the medium surrounding the supernova in great detail. Powered by the dynamical interaction of the ejecta with the inner circumstellar ring, SN 1987A is dramatically evolving at all wavelengths on time scales less than a year. This makes SN 1987A a great ``laboratory'' for studies of shock physics. Repeated observations of the ejecta-ring collision have been carried out using the UVES echelle spectrograph at VLT. This thesis covers seven epochs of high resolution spectra taken between October 1999 and November 2007. Three different emission line components are identified from the spectra. A narrow (~10 km/s) velocity component emerges from the unshocked ring. An intermediate (~250 km/s) component arises in the shocked ring, and a broad component extending to ~15,000 km/s comes from the reverse shock. Thanks to the high spectral resolution of UVES, it has been possible to separate the shocked from the unshocked ring emission. For the unshocked gas, ionization stages from neutral up to Ne V and Fe VII were found. The line fluxes of the low-ionization lines decline during the period of the observations. However, the fluxes of the [O III] and [Ne III] lines appear to increase and this is found to be consistent with the heating of the pre-shock gas by X-rays from the shock interactions. The line emission from the ejecta-ring collision increases rapidly as more gas is swept up by the shocks. This emission comes from ions with a range of ionization stages (e.g., Fe II-XIV). The low-ionization lines show an increase in their line widths which is consistent with that these lines originate from radiative shocks. The

  15. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Estimated thickness of ejecta deposits compared to to crater rim heights. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    The area of the continuous ejecta deposits on mercury was calculated to vary from 2.24 to 0.64 times the crater's area for those of diameter 40 km to 300 km. Because crater boundaries on the geologic map include the detectable continuous ejecta blanket, plains exterior to these deposits must consist of farther-flung ejecta (of that or other craters), or volcanic deposits flooding the intervening areas. Ejecta models are explored.

  16. Ejecta Particle-Size Measurements in Vacuum and Helium Gas using Ultraviolet In-Line Fraunhofer Holography

    Energy Technology Data Exchange (ETDEWEB)

    Sorenson, Danny S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pazuchanics, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johnson, Randall P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Malone, R. M. [National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States); Kaufman, M. I. [National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States); Tibbitts, A. [National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States); Tunnell, T. [National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States); Marks, D. [National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States); Capelle, G. A. [National Security Technologies, LLC. (NSTec), Santa Barbara, CA (United States); Grover, M. [National Security Technologies, LLC. (NSTec), Santa Barbara, CA (United States); Marshall, B. [National Security Technologies, LLC. (NSTec), Santa Barbara, CA (United States); Stevens, G. D. [National Security Technologies, LLC. (NSTec), Santa Barbara, CA (United States); Turley, W. D. [National Security Technologies, LLC. (NSTec), Santa Barbara, CA (United States); LaLone, B. [National Security Technologies, LLC. (NSTec), Santa Barbara, CA (United States)

    2014-06-25

    An Ultraviolet (UV) in-line Fraunhofer holography diagnostic has been developed for making high-resolution spatial measurements of ejecta particles traveling at many mm/μsec. This report will discuss the development of the diagnostic including the high-powered laser system and high-resolution optical relay system. In addition, the system required to reconstruct the images from the hologram and the corresponding analysis of those images to extract particles will also be described. Finally, results from six high-explosive (HE), shock-driven Sn ejecta experiments will be presented. Particle size distributions will be shown that cover most of the ejecta velocities for experiments conducted in a vacuum, and helium gas environments. In addition, a modification has been made to the laser system that produces two laser pulses separated by 6.8 ns. This double-pulsed capability allows a superposition of two holograms to be acquired at two different times, thus allowing ejecta velocities to be measured directly. Results from this double pulsed experiment will be described.

  17. Radio Emission from Pulsar Wind Nebulae without Surrounding Supernova Ejecta: Application to FRB 121102

    International Nuclear Information System (INIS)

    Dai, Z. G.; Wang, J. S.; Yu, Y. W.

    2017-01-01

    In this paper, we propose a new scenario in which a rapidly rotating strongly magnetized pulsar without any surrounding supernova ejecta repeatedly produces fast radio bursts (FRBs) via a range of possible mechanisms; simultaneously, an ultra-relativistic electron/positron pair wind from the pulsar sweeps up its ambient dense interstellar medium, giving rise to a non-relativistic pulsar wind nebula (PWN). We show that the synchrotron radio emission from such a PWN is bright enough to account for the recently discovered persistent radio source associated with the repeating FRB 121102 within reasonable ranges of the model parameters. Our PWN scenario is consistent with the non-evolution of the dispersion measure inferred from all of the repeating bursts observed in four years.

  18. Asymmetric ejecta of cool supergiants and hypergiants in the massive cluster Westerlund 1

    Science.gov (United States)

    Andrews, H.; Fenech, D.; Prinja, R. K.; Clark, J. S.; Hindson, L.

    2018-06-01

    We report new 5.5 GHz radio observations of the massive star cluster Westerlund 1, taken by the Australia Telescope Compact Array, detecting nine of the ten yellow hypergiants (YHGs) and red supergiants (RSGs) within the cluster. Eight of nine sources are spatially resolved. The nebulae associated with the YHGs Wd1-4a, -12a, and -265 demonstrate a cometary morphology - the first time this phenomenon has been observed for such stars. This structure is also echoed in the ejecta of the RSGs Wd1-20 and -26; in each case the cometary tails are directed away from the cluster core. The nebular emission around the RSG Wd1-237 is less collimated than these systems but once again appears more prominent in the hemisphere facing the cluster. Considered as a whole, the nebular morphologies provide compelling evidence for sculpting via a physical agent associated with Westerlund 1, such as a cluster wind.

  19. Radio Emission from Pulsar Wind Nebulae without Surrounding Supernova Ejecta: Application to FRB 121102

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Z. G.; Wang, J. S. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Yu, Y. W., E-mail: dzg@nju.edu.cn [Institute of Astrophysics, Central China Normal University, Wuhan 430079 (China)

    2017-03-20

    In this paper, we propose a new scenario in which a rapidly rotating strongly magnetized pulsar without any surrounding supernova ejecta repeatedly produces fast radio bursts (FRBs) via a range of possible mechanisms; simultaneously, an ultra-relativistic electron/positron pair wind from the pulsar sweeps up its ambient dense interstellar medium, giving rise to a non-relativistic pulsar wind nebula (PWN). We show that the synchrotron radio emission from such a PWN is bright enough to account for the recently discovered persistent radio source associated with the repeating FRB 121102 within reasonable ranges of the model parameters. Our PWN scenario is consistent with the non-evolution of the dispersion measure inferred from all of the repeating bursts observed in four years.

  20. ELEMENTAL ABUNDANCES IN THE EJECTA OF OLD CLASSICAL NOVAE FROM LATE-EPOCH SPITZER SPECTRA

    International Nuclear Information System (INIS)

    Helton, L. Andrew; Vacca, William D.; Gehrz, Robert D.; Woodward, Charles E.; Shenoy, Dinesh P.; Wagner, R. Mark; Evans, Aneurin; Krautter, Joachim; Schwarz, Greg J.; Starrfield, Sumner

    2012-01-01

    We present Spitzer Space Telescope mid-infrared IRS spectra, supplemented by ground-based optical observations, of the classical novae V1974 Cyg, V382 Vel, and V1494 Aql more than 11, 8, and 4 years after outburst, respectively. The spectra are dominated by forbidden emission from neon and oxygen, though in some cases, there are weak signatures of magnesium, sulfur, and argon. We investigate the geometry and distribution of the late time ejecta by examination of the emission line profiles. Using nebular analysis in the low-density regime, we estimate lower limits on the abundances in these novae. In V1974 Cyg and V382 Vel, our observations confirm the abundance estimates presented by other authors and support the claims that these eruptions occurred on ONe white dwarfs (WDs). We report the first detection of neon emission in V1494 Aql and show that the system most likely contains a CO WD.

  1. ELEMENTAL ABUNDANCES IN THE EJECTA OF OLD CLASSICAL NOVAE FROM LATE-EPOCH SPITZER SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Helton, L. Andrew; Vacca, William D. [SOFIA Science Center, USRA, NASA Ames Research Center, M.S. N232-11, Moffett Field, CA 94035 (United States); Gehrz, Robert D.; Woodward, Charles E.; Shenoy, Dinesh P. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Wagner, R. Mark [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Evans, Aneurin [Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Krautter, Joachim [Landessternwarte-Zentrum fuer Astronomie der Universitaet, Koenigstuhl, D-69117 Heidelberg (Germany); Schwarz, Greg J. [American Astronomical Society, 2000 Florida Avenue, NW, Suite 400, Washington, DC 20009 (United States); Starrfield, Sumner, E-mail: ahelton@sofia.usra.edu [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States)

    2012-08-10

    We present Spitzer Space Telescope mid-infrared IRS spectra, supplemented by ground-based optical observations, of the classical novae V1974 Cyg, V382 Vel, and V1494 Aql more than 11, 8, and 4 years after outburst, respectively. The spectra are dominated by forbidden emission from neon and oxygen, though in some cases, there are weak signatures of magnesium, sulfur, and argon. We investigate the geometry and distribution of the late time ejecta by examination of the emission line profiles. Using nebular analysis in the low-density regime, we estimate lower limits on the abundances in these novae. In V1974 Cyg and V382 Vel, our observations confirm the abundance estimates presented by other authors and support the claims that these eruptions occurred on ONe white dwarfs (WDs). We report the first detection of neon emission in V1494 Aql and show that the system most likely contains a CO WD.

  2. Life near the Roche limit - Behavior of ejecta from satellites close to planets

    Science.gov (United States)

    Dobrovolskis, A. R.; Burns, J. A.

    1980-01-01

    A study of the dynamics of nearby debris from impact craters was made to explain the distinctive features seen on Phobos, Deimis, and Amalthea. The planetary tides and satellite rotation were considered, and the usual pseudo-energy (Jacobi) integral was numerically calculated in the framework of a restricted body problem where satellites are modelled as triaxial ellipsoids rather than point masses. Iso-contours of this integral show that Deimos and Amalthea are entirely closed by Roche lobes, and the surfaces of their model ellipsoids lie nearly along equipotentials. Presently, the surface of Phobos overflows its Roche lobe, except for regions within a few km of the sub-Mars and anti-Mars points. The behavior of crater ejecta from the satellites of Mars were also examined by numerical integration of trajectories for particles leaving their surfaces in the equatorial plane.

  3. Martian Low-Aspect-Ratio Layered Ejecta (LARLE) craters: Distribution, characteristics, and relationship to pedestal craters

    Science.gov (United States)

    Barlow, Nadine G.; Boyce, Joseph M.; Cornwall, Carin

    2014-09-01

    Low-Aspect-Ratio Layered Ejecta (LARLE) craters are a unique landform found on Mars. LARLE craters are characterized by a crater and normal layered ejecta pattern surrounded by an extensive but thin outer deposit which terminates in a sinuous, almost flame-like morphology. We have conducted a survey to identify all LARLE craters ⩾1-km-diameter within the ±75° latitude zone and to determine their morphologic and morphometric characteristics. The survey reveals 140 LARLE craters, with the majority (91%) located poleward of 40°S and 35°N and all occurring within thick mantles of fine-grained deposits which are likely ice-rich. LARLE craters range in diameter from the cut-off limit of 1 km up to 12.2 km, with 83% being smaller than 5 km. The radius of the outer LARLE deposit displays a linear trend with the crater radius and is greatest at higher polar latitudes. The LARLE deposit ranges in length between 2.56 and 14.81 crater radii in average extent, with maximum length extending up to 21.4 crater radii. The LARLE layer is very sinuous, with lobateness values ranging between 1.45 and 4.35. LARLE craters display a number of characteristics in common with pedestal craters and we propose that pedestal craters are eroded versions of LARLE craters. The distribution and characteristics of the LARLE craters lead us to propose that impact excavation into ice-rich fine-grained deposits produces a dusty base surge cloud (like those produced by explosion craters) that deposits dust and ice particles to create the LARLE layers. Salts emplaced by upward migration of water through the LARLE deposit produce a surficial duricrust layer which protects the deposit from immediate removal by eolian processes.

  4. Overlapping Ballistic Ejecta Fields: Separating Distinct Blasts at Kings Bowl, Idaho

    Science.gov (United States)

    Borg, C.; Kobs-Nawotniak, S. E.; Hughes, S. S.; Sears, D. W. G.; Heldmann, J. L.; Lim, D. S. S.; Haberle, C. W.; Sears, H.; Elphic, R. C.; Kobayashi, L.; Garry, W. B.; Neish, C.; Karunatillake, S.; Button, N.; Purcell, S.; Mallonee, H.; Ostler, B.

    2015-12-01

    Kings Bowl is a ~2200ka pit crater created by a phreatic blast along a volcanic fissure in the eastern Snake River Plain (ESRP), Idaho. The main crater measures approximately 80m in length, 30m in width, and 30m in depth, with smaller pits located nearby on the Great Rift fissure, and has been targeted by the FINESSE team as a possible analogue for Cyane Fossae, Mars. The phreatic eruption is believed to have occurred due to the interaction of groundwater with lava draining back into the fissure following a lava lake high stand, erupting already solidified basalt from this and previous ERSP lava flows. The contemporaneous draw back of the lava with the explosions may conceal some smaller possible blast pits as more lava drained into the newly formed pits. Ballistic ejecta from the blasts occur on both sides of the fissure. To the east, the ballistic blocks are mantled by fine tephra mixed with eolian dust, the result of a westerly wind during the explosions. We use differential GPS to map the distribution of ballistic blocks on the west side of the fissure, recording position, percent vesiculation, and the length of 3 mutually perpendicular axes for each block >20cm along multiple transects parallel to the fissure. From the several hundred blocks recorded, we have been able to separate the ballistic field into several distinct blast deposits on the basis of size distributions and block concentration. The smaller pits identified from the ballistic fields correspond broadly to the northern and southern limits of the tephra/dust field east of the fissure. Soil formation and bioturbation of the tephra by sagebrush have obliterated any tephrostratigraphy that could have been linked to individual blasts. The ballistic block patterns at Kings Bowl may be used to identify distinct ejecta groups in high-resolution imagery of Mars or other planetary bodies.

  5. Geochemistry of K/T-boundary Chicxulub ejecta of NE-Mexico

    Science.gov (United States)

    Harting, M.; Deutsch, A.; Rickers, K.

    2003-12-01

    Many K/T sections all over the world contain impact spherules supposed related to the Chicxulub event. This study focus on ejecta layers in NE-Mexican profiles. We carried out systematic XRF and synchrotron radiation measurements on such spherules at the HASYLAB and ANKA facilities as well as microprobe analyses (CAMECA SX50). Area scans on tektite-like material of the Bochil section reveal a pronounced zonation in the inner part, dominated by Ba and Sr whereas secondary CaCO3 dominates in the altered margin. The composition of the spherules from the Mesa-Juan Perez section differ significantly from the Beloc (Haiti) and Bochil tektite glasses. At Mesa-Juan Perez, spherules are either extremely rich in Fe and Ca or consist of smectite, some of those carry carbonate inclusions. Yttrium, La and Ce are zoned within the smectite with concentrations below the detection limit and up to 20 æg/g The Ca-rich inclusions are enriched in Y (up to 35 æg/g) and La (18 æg/g) and, compared to the surrounding smectite, also in Ce (up to 34 æg/g). The Ce enrichment in spherules from the Mesa-Juan Perez section indicates impact-melted carbonates of the Yucatan carbonate platform as possible precursor rocks. Recent investigations focus on the chemistry of melt rock samples from the PEMEX wells Yucatan-6 and Chicxulub-1: Their average composition (mean of 250 data points in wt-percent ) is 61.6 for SiO2, 0.16 for TiO2, 18.07 for Al2O3, 0.01 for Cr2O3, 1.98 for Na2O, 1.5 for FeO, 0.05 for MnO, 0.01 for NiO, 0.31 for MgO, 9.14 for K2O, 3.44 for CaO, and 0.01 for SO2. These results are in some cases comparable to the geochemistry of ejecta glasses, e.g. from Beloc (Haiti).

  6. The Search for Sustainable Subsurface Habitats on Mars, and the Sampling of Impact Ejecta

    Directory of Open Access Journals (Sweden)

    Paula Lindgren

    2010-07-01

    Full Text Available On Earth, the deep subsurface biosphere of both the oceanic and the continental crust is well known for surviving harsh conditions and environments characterized by high temperatures, high pressures, extreme pHs, and the absence of sunlight. The microorganisms of the terrestrial deep biosphere have an excellent capacity for adapting to changing geochemistry, as the alteration of the crust proceeds and the conditions of their habitats slowly change. Despite an almost complete isolation from surface conditions and the surface biosphere, the deep biosphere of the crustal rocks has endured over geologic time. This indicates that the deep biosphere is a self-sufficient system, independent of the global events that occur at the surface, such as impacts, glaciations, sea level fluctuations, and climate changes. With our sustainable terrestrial subsurface biosphere in mind, the subsurface on Mars has often been suggested as the most plausible place to search for fossil Martian life, or even present Martian life. Since the Martian surface is more or less sterile, subsurface settings are the only place on Mars where life could have been sustained over geologic time. To detect a deep biosphere in the Martian basement, drilling is a requirement. However, near future Mars sample return missions are limited by the mission’s payload, which excludes heavy drilling equipment and restrict the missions to only dig the topmost meter of the Martian soil. Therefore, the sampling and analysis of Martian impact ejecta has been suggested as a way of accessing the deeper Martian subsurface without using heavy drilling equipment. Impact cratering is a natural geological process capable of excavating and exposing large amounts of rock material from great depths up to the surface. Several studies of terrestrial impact deposits show the preservation of pre-impact biosignatures, such as fossilized organisms and chemical biological markers. Therefore, if the Martian

  7. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  8. X-ray emission due to interaction of SN1987A ejecta with its progenitor's stellar-wind matter

    International Nuclear Information System (INIS)

    Masai, Kuniaki.

    1990-06-01

    The progenitor of the supernova 1987A, Sk-69 202 probably had lost a considerable amount of mass in its stellar wind in the past evolutionary track through a red supergiant to a blue supergiant. In about 10 years, the expanding ejecta of SN1987A will catch up to collide with the wind matter ejected in the red supergiant phase. Shocks due to the collision will heat up the ejecta and the wind matter to cause an enhancement of thermal X-ray emission lasting for several decades. We predict the X-ray light curve and the spectrum as well as the epoch of the enhancement intending to encourage future X-ray observations, which will give a clue for the study of such peculiar stellar evolution with a blueward transition as Sk-69 202. (author)

  9. The γ-rays that accompanied GW170817 and the observational signature of a magnetic jet breaking out of NS merger ejecta

    Science.gov (United States)

    Bromberg, O.; Tchekhovskoy, A.; Gottlieb, O.; Nakar, E.; Piran, T.

    2018-04-01

    We present the first relativistic magnetohydrodynamics numerical simulation of a magnetic jet that propagates through and emerges from the dynamical ejecta of a binary neutron star merger. Generated by the magnetized rotation of the merger remnant, the jet propagates through the ejecta and produces an energetic cocoon that expands at mildly relativistic velocities and breaks out of the ejecta. We show that if the ejecta has a low-mass (˜10-7 M⊙) high-velocity (v ˜ 0.85c) tail, the cocoon shock breakout will generate γ-ray emission that is comparable to the observed short GRB170817A that accompanied the recent gravitational wave event GW170817. Thus, we propose that this gamma-ray burst (GRB), which is quite different from all other short GRBs observed before, was produced by a different mechanism. We expect, however, that such events are numerous and many will be detected in coming LIGO-Virgo runs.

  10. Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D

    Energy Technology Data Exchange (ETDEWEB)

    Abellán, F. J.; Marcaide, J. M. [Departamento de Astronomía y Astrofísica, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Indebetouw, R.; Chevalier, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Gabler, M.; Janka, H.-Th. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching (Germany); Fransson, C.; Lundqvist, P. [Department of Astronomy, The Oskar Klein Centre, Stockholm University, Alba Nova University Centre, SE-106 91 Stockholm (Sweden); Spyromilio, J. [ESO, Karl-Schwarzschild-Straße 2, D-85748 Garching (Germany); Burrows, D. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Cigan, P.; Gomez, H. L.; Matsuura, M. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Gaensler, B. M. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Larsson, J. [KTH, Department of Physics, and the Oskar Klein Centre, AlbaNova, SE-106 91 Stockholm (Sweden); McCray, R. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Park, S. [Department of Physics, University of Texas at Arlington, 108 Science Hall, Box 19059, Arlington, TX 76019 (United States); Roche, P., E-mail: francisco.abellan@uv.es [Department of Physics, University of Oxford, Oxford OX1 3RH (United Kingdom); and others

    2017-06-20

    Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outward through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Atacama Large Millimeter/submillimeter Array are of the highest resolution to date and reveal the detailed morphology of cold molecular gas in the innermost regions of the remnant. The 3D distributions of carbon and silicon monoxide (CO and SiO) emission differ, but both have a central deficit, or torus-like distribution, possibly a result of radioactive heating during the first weeks (“nickel heating”). The size scales of the clumpy distribution are compared quantitatively to models, demonstrating how progenitor and explosion physics can be constrained.

  11. Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D

    International Nuclear Information System (INIS)

    Abellán, F. J.; Marcaide, J. M.; Indebetouw, R.; Chevalier, R.; Gabler, M.; Janka, H.-Th.; Fransson, C.; Lundqvist, P.; Spyromilio, J.; Burrows, D. N.; Cigan, P.; Gomez, H. L.; Matsuura, M.; Gaensler, B. M.; Kirshner, R.; Larsson, J.; McCray, R.; Ng, C.-Y.; Park, S.; Roche, P.

    2017-01-01

    Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outward through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Atacama Large Millimeter/submillimeter Array are of the highest resolution to date and reveal the detailed morphology of cold molecular gas in the innermost regions of the remnant. The 3D distributions of carbon and silicon monoxide (CO and SiO) emission differ, but both have a central deficit, or torus-like distribution, possibly a result of radioactive heating during the first weeks (“nickel heating”). The size scales of the clumpy distribution are compared quantitatively to models, demonstrating how progenitor and explosion physics can be constrained.

  12. A STUBBORNLY LARGE MASS OF COLD DUST IN THE EJECTA OF SUPERNOVA 1987A

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, M.; Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Dwek, E. [Observational Cosmology Laboratory Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Babler, B. [Department of Astronomy, 475 North Charter Street, University of Wisconsin, Madison, WI 53706 (United States); Baes, M.; Fritz, Jacopo [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cernicharo, José [Departamento de Astrofísica, Centro de Astrobiología, CSIC-INTA, Ctra. de Torrejón a Ajalvir km 4, E-28850 Madrid (Spain); Clayton, Geoff C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Dunne, L. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Fransson, C.; Lundqvist, P. [The Oskar Klein Centre, Department of Astronomy, Stockholm University, Albanova, SE-10691 Stockholm (Sweden); Gear, Walter; Gomez, H. L. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Groenewegen, M. A. T. [Koninklijke Sterrenwacht van België, Ringlaan 3, 1180 Brussel (Belgium); Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Ivison, R. J. [SUPA, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Jerkstrand, A. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Lebouteiller, V. [AIM, CEA/Saclay, L' Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Lim, T. L., E-mail: mikako@star.ucl.ac.uk [RAL Space, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); and others

    2015-02-10

    We present new Herschel photometric and spectroscopic observations of Supernova 1987A, carried out in 2012. Our dedicated photometric measurements provide new 70 μm data and improved imaging quality at 100 and 160 μm compared to previous observations in 2010. Our Herschel spectra show only weak CO line emission, and provide an upper limit for the 63 μm [O I] line flux, eliminating the possibility that line contaminations distort the previously estimated dust mass. The far-infrared spectral energy distribution (SED) is well fitted by thermal emission from cold dust. The newly measured 70 μm flux constrains the dust temperature, limiting it to nearly a single temperature. The far-infrared emission can be fitted by 0.5 ± 0.1 M {sub ☉} of amorphous carbon, about a factor of two larger than the current nucleosynthetic mass prediction for carbon. The observation of SiO molecules at early and late phases suggests that silicates may also have formed and we could fit the SED with a combination of 0.3 M {sub ☉} of amorphous carbon and 0.5 M {sub ☉} of silicates, totalling 0.8 M {sub ☉} of dust. Our analysis thus supports the presence of a large dust reservoir in the ejecta of SN 1987A. The inferred dust mass suggests that supernovae can be an important source of dust in the interstellar medium, from local to high-redshift galaxies.

  13. A DECADE-BASELINE STUDY OF THE PLASMA STATES OF EJECTA KNOTS IN CASSIOPEIA A

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, John; Dewey, Daniel; Figueroa-Feliciano, Enectali; Heine, Sarah N. T.; Canizares, C. R.; Bastien, Fabienne A.; Sato, Kosuke, E-mail: enectali@mit.edu, E-mail: jmrv@mit.edu [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-05-20

    We present the analysis of 21 bright X-ray knots in the Cassiopeia A supernova remnant from observations spanning 10 yr. We performed a comprehensive set of measurements to reveal the kinematic and thermal state of the plasma in each knot, using a combined analysis of two high energy resolution High Energy Transmission Grating (HETG) and four medium energy resolution Advanced CCD Imaging Spectrometer (ACIS) sets of spectra. The ACIS electron temperature estimates agree with the HETG-derived values for approximately half of the knots studied, yielding one of the first comparisons between high resolution temperature estimates and ACIS-derived temperatures. We did not observe the expected spectral evolution-predicted from the ionization age and density estimates for each knot-in all but three of the knots studied. The incompatibility of these measurements with our assumptions has led us to propose a dissociated ejecta model, with the metals unmixed inside the knots, which could place strong constraints on supernova mixing models.

  14. Radiative bow shock wave (?) driven by nuclear ejecta in a Seyfert galaxy

    International Nuclear Information System (INIS)

    Wilson, A.S.; Ulvestad, J.S.; California Institute of Technology, Pasadena)

    1987-01-01

    New VLA maps at 2 cm of the 13-arcsec-scale linear radio source in the center of NGC 1068 are described. The northeast lobe shows a limb-brightened conical morphology, very sharp leading edges, and a magnetic field running parallel to these edges. The spectral index between 2 and 6 cm in these line-brightened regions is near 1.0. The northeast subpeak has a very steep radio spectrum between 18 and 2 cm which is attributed to inverse Compton losses of the relativistic electrons on the infrared photons. The spectral indices in the southwest lobe lie in the range 0.9-1.5 except in its northern parts, where a much larger index is found. The northeast lobe radio emission could arise in either the cocoon of old jet material which has passed through the internal shock in the ejecta and blown out to either side, or in interstellar material compressed by a bow shock wave driven into the galactic ISM. 45 references

  15. Science goals and expected results from the smart-1 amie multi-coulour micro-camera

    Science.gov (United States)

    Josset, J.-L.; AMIE Team

    2003-04-01

    The Advanced Moon micro-Imager Experiment (AMIE), which will be on board ESA SMART-1, the first European mission to the Moon (launch foreseen in 2003), is an imaging system with scientific, technical and public outreach oriented objectives. The science objectives are to image the Lunar South Pole (Aitken basin), permanent shadow areas (ice deposit), eternal light (crater rims), ancient Lunar Nonmare volcanism, local spectro-photometry and physical state of the lunar surface, and to map high latitudes regions (south) mainly at far side. The main science goals and the expected results from the AMIE multi-colour micro-camera are presented.

  16. Dynamical ejecta from precessing neutron star-black hole mergers with a hot, nuclear-theory based equation of state

    International Nuclear Information System (INIS)

    Foucart, F; Kasen, D; Desai, D; Brege, W; Duez, M D; Hemberger, D A; Scheel, M A; Kidder, L E; Pfeiffer, H P

    2017-01-01

    Neutron star-black hole binaries are among the strongest sources of gravitational waves detectable by current observatories. They can also power bright electromagnetic signals (gamma-ray bursts, kilonovae), and may be a significant source of production of r-process nuclei. A misalignment of the black hole spin with respect to the orbital angular momentum leads to precession of that spin and of the orbital plane, and has a significant effect on the properties of the post-merger remnant and of the material ejected by the merger. We present a first set of simulations of precessing neutron star-black hole mergers using a hot, composition dependent, nuclear-theory based equation of state (DD2). We show that the mass of the remnant and of the dynamical ejecta are broadly consistent with the result of simulations using simpler equations of state, while differences arise when considering the dynamics of the merger and the velocity of the ejecta. We show that the latter can easily be understood from assumptions about the composition of low-density, cold material in the different equations of state, and propose an updated estimate for the ejecta velocity which takes those effects into account. We also present an updated mesh-refinement algorithm which allows us to improve the numerical resolution used to evolve neutron star-black hole mergers. (paper)

  17. THE CHEMISTRY OF POPULATION III SUPERNOVA EJECTA. II. THE NUCLEATION OF MOLECULAR CLUSTERS AS A DIAGNOSTIC FOR DUST IN THE EARLY UNIVERSE

    International Nuclear Information System (INIS)

    Cherchneff, Isabelle; Dwek, Eli

    2010-01-01

    We study the formation of molecular precursors to dust in the ejecta of Population III supernovae (Pop. III SNe) using a chemical kinetic approach to follow the evolution of small dust cluster abundances from day 100 to day 1000 after explosion. Our work focuses on zero-metallicity 20 M sun and 170 M sun progenitors, and we consider fully macroscopically mixed and unmixed ejecta. The dust precursors comprise molecular chains, rings, and small clusters of chemical composition relevant to the initial elemental composition of the ejecta under study. The nucleation stage for small silica, metal oxides and sulfides, pure metal, and carbon clusters is described with a new chemical reaction network highly relevant to the kinetic description of dust formation in hot circumstellar environments. We consider the effect of the pressure dependence of critical nucleation rates and test the impact of microscopically mixed He + on carbon dust formation. Two cases of metal depletion on silica clusters (full and no depletion) are considered to derive upper limits to the amounts of dust produced in SN ejecta at 1000 days, while the chemical composition of clusters gives a prescription for the type of dust formed in Pop. III SNe. We show that the cluster mass produced in the fully mixed ejecta of a 170 M sun progenitor is ∼ 25 M sun whereas its 20 M sun counterpart forms ∼ 0.16 M sun of clusters. The unmixed ejecta of a 170 M sun progenitor SN synthesize ∼5.6 M sun of small clusters, while its 20 M sun counterpart produces ∼0.103 M sun . Our results point to smaller amounts of dust formed in the ejecta of Pop. III SNe by a factor of ∼ 5 compared to values derived by previous studies, and to different dust chemical compositions. Such deviations result from some erroneous assumptions made, the inappropriate use of classical nucleation theory to model dust formation, and the omission of the synthesis of molecules in SN ejecta. We also find that the unmixed ejecta of massive Pop

  18. The Chemistry of Population III Supernova Ejecta. II. The Nucleation of Molecular Clusters as a Diagnostic for Dust in the Early Universe

    Science.gov (United States)

    Cherchneff, Isabelle; Dwek, Eli

    2010-04-01

    We study the formation of molecular precursors to dust in the ejecta of Population III supernovae (Pop. III SNe) using a chemical kinetic approach to follow the evolution of small dust cluster abundances from day 100 to day 1000 after explosion. Our work focuses on zero-metallicity 20 M sun and 170 M sun progenitors, and we consider fully macroscopically mixed and unmixed ejecta. The dust precursors comprise molecular chains, rings, and small clusters of chemical composition relevant to the initial elemental composition of the ejecta under study. The nucleation stage for small silica, metal oxides and sulfides, pure metal, and carbon clusters is described with a new chemical reaction network highly relevant to the kinetic description of dust formation in hot circumstellar environments. We consider the effect of the pressure dependence of critical nucleation rates and test the impact of microscopically mixed He+ on carbon dust formation. Two cases of metal depletion on silica clusters (full and no depletion) are considered to derive upper limits to the amounts of dust produced in SN ejecta at 1000 days, while the chemical composition of clusters gives a prescription for the type of dust formed in Pop. III SNe. We show that the cluster mass produced in the fully mixed ejecta of a 170 M sun progenitor is ~ 25 M sun whereas its 20 M sun counterpart forms ~ 0.16 M sun of clusters. The unmixed ejecta of a 170 M sun progenitor SN synthesize ~5.6 M sun of small clusters, while its 20 M sun counterpart produces ~0.103 M sun. Our results point to smaller amounts of dust formed in the ejecta of Pop. III SNe by a factor of ~ 5 compared to values derived by previous studies, and to different dust chemical compositions. Such deviations result from some erroneous assumptions made, the inappropriate use of classical nucleation theory to model dust formation, and the omission of the synthesis of molecules in SN ejecta. We also find that the unmixed ejecta of massive Pop. III SNe

  19. TYPE Ia SUPERNOVA COLORS AND EJECTA VELOCITIES: HIERARCHICAL BAYESIAN REGRESSION WITH NON-GAUSSIAN DISTRIBUTIONS

    International Nuclear Information System (INIS)

    Mandel, Kaisey S.; Kirshner, Robert P.; Foley, Ryan J.

    2014-01-01

    We investigate the statistical dependence of the peak intrinsic colors of Type Ia supernovae (SNe Ia) on their expansion velocities at maximum light, measured from the Si II λ6355 spectral feature. We construct a new hierarchical Bayesian regression model, accounting for the random effects of intrinsic scatter, measurement error, and reddening by host galaxy dust, and implement a Gibbs sampler and deviance information criteria to estimate the correlation. The method is applied to the apparent colors from BVRI light curves and Si II velocity data for 79 nearby SNe Ia. The apparent color distributions of high-velocity (HV) and normal velocity (NV) supernovae exhibit significant discrepancies for B – V and B – R, but not other colors. Hence, they are likely due to intrinsic color differences originating in the B band, rather than dust reddening. The mean intrinsic B – V and B – R color differences between HV and NV groups are 0.06 ± 0.02 and 0.09 ± 0.02 mag, respectively. A linear model finds significant slopes of –0.021 ± 0.006 and –0.030 ± 0.009 mag (10 3 km s –1 ) –1 for intrinsic B – V and B – R colors versus velocity, respectively. Because the ejecta velocity distribution is skewed toward high velocities, these effects imply non-Gaussian intrinsic color distributions with skewness up to +0.3. Accounting for the intrinsic-color-velocity correlation results in corrections to A V extinction estimates as large as –0.12 mag for HV SNe Ia and +0.06 mag for NV events. Velocity measurements from SN Ia spectra have the potential to diminish systematic errors from the confounding of intrinsic colors and dust reddening affecting supernova distances

  20. Thermal History of CBb Chondrules and Cooling Rate Distributions of Ejecta Plumes

    Science.gov (United States)

    Hewins, R. H.; Condie, C.; Morris, M.; Richardson, M. L. A.; Ouellette, N.; Metcalf, M.

    2018-03-01

    It has been proposed that some meteorites, CB and CH chondrites, contain material formed as a result of a protoplanetary collision during accretion. Their melt droplets (chondrules) and FeNi metal are proposed to have formed by evaporation and condensation in the resulting impact plume. We observe that the skeletal olivine (SO) chondrules in CBb chondrites have a blebby texture and an enrichment in refractory elements not found in normal chondrules. Because the texture requires complete melting, their maximum liquidus temperature of 1928 K represents a minimum temperature for the putative plume. Dynamic crystallization experiments show that the SO texture can be created only by brief reheating episodes during crystallization, giving a partial dissolution of olivine. The ejecta plume formed in a smoothed particle hydrodynamics simulation served as the basis for 3D modeling with the adaptive mesh refinement code FLASH4.3. Tracer particles that move with the fluid cells are used to measure the in situ cooling rates. Their cooling rates are ∼10,000 K hr‑1 briefly at peak temperature and, in the densest regions of the plume, ∼100 K hr‑1 for 1400–1600 K. A small fraction of cells is seen to be heating at any one time, with heating spikes explained by the compression of parcels of gas in a heterogeneous patchy plume. These temperature fluctuations are comparable to those required in crystallization experiments. For the first time, we find an agreement between experiments and models that supports the plume model specifically for the formation of CBb chondrules.

  1. Development of an ejecta particle size measurement diagnostic based on Mie scattering

    Energy Technology Data Exchange (ETDEWEB)

    Schauer, Martin Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Buttler, William Tillman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Frayer, Daniel K. [National Security Tech, Inc., Los Alamos, NM (United States); Grover, Michael [National Security Technologies, Santa Barbara, CA (United States). Special Technologies Lab.; Monfared, Shabnam Kalighi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stevens, Gerald D. [National Security Technologies, Santa Barbara, CA (United States). Special Technologies Lab.; Stone, Benjamin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Turley, William Dale [National Security Technologies, Santa Barbara, CA (United States). Special Technologies Lab.

    2017-09-27

    The goal of this work is to determine the feasibility of extracting the size of particles ejected from shocked metal surfaces (ejecta) from the angular distribution of light scattered by a cloud of such particles. The basis of the technique is the Mie theory of scattering, and implicit in this approach are the assumptions that the scattering particles are spherical and that single scattering conditions prevail. The meaning of this latter assumption, as far as experimental conditions are concerned, will become clear later. The solution to Maxwell’s equations for spherical particles illuminated by a plane electromagnetic wave was derived by Gustav Mie more than 100 years ago, but several modern treatises discuss this solution in great detail. The solution is a complicated series expansion of the scattered electric field, as well as the field within the particle, from which the total scattering and absorption cross sections as well as the angular distribution of scattered intensity can be calculated numerically. The detailed nature of the scattering is determined by the complex index of refraction of the particle material as well as the particle size parameter, x, which is the product of the wavenumber of the incident light and the particle radius, i.e. x = 2rπ= λ. Figure 1 shows the angular distribution of scattered light for different particle size parameters and two orthogonal incident light polarizations as calculated using the Mie solution. It is obvious that the scattering pattern is strongly dependent on the particle size parameter, becoming more forward-directed and less polarizationdependent as the particle size parameter increases. This trend forms the basis for the diagnostic design.

  2. An Observational Approach toward Understanding and Prediction of CME Magnetic Ejecta

    Science.gov (United States)

    Pizzo, V. J.; de Koning, C. A.; Riley, P.

    2017-12-01

    understanding and forecasting magnetic ejecta is possible via a cube-sat swarm.

  3. Multibillion-atom Molecular Dynamics Simulations of Plasticity, Spall, and Ejecta

    Science.gov (United States)

    Germann, Timothy C.

    2007-06-01

    Modern supercomputing platforms, such as the IBM BlueGene/L at Lawrence Livermore National Laboratory and the Roadrunner hybrid supercomputer being built at Los Alamos National Laboratory, are enabling large-scale classical molecular dynamics simulations of phenomena that were unthinkable just a few years ago. Using either the embedded atom method (EAM) description of simple (close-packed) metals, or modified EAM (MEAM) models of more complex solids and alloys with mixed covalent and metallic character, simulations containing billions to trillions of atoms are now practical, reaching volumes in excess of a cubic micron. In order to obtain any new physical insights, however, it is equally important that the analysis of such systems be tractable. This is in fact possible, in large part due to our highly efficient parallel visualization code, which enables the rendering of atomic spheres, Eulerian cells, and other geometric objects in a matter of minutes, even for tens of thousands of processors and billions of atoms. After briefly describing the BlueGene/L and Roadrunner architectures, and the code optimization strategies that were employed, results obtained thus far on BlueGene/L will be reviewed, including: (1) shock compression and release of a defective EAM Cu sample, illustrating the plastic deformation accompanying void collapse as well as the subsequent void growth and linkup upon release; (2) solid-solid martensitic phase transition in shock-compressed MEAM Ga; and (3) Rayleigh-Taylor fluid instability modeled using large-scale direct simulation Monte Carlo (DSMC) simulations. I will also describe our initial experiences utilizing Cell Broadband Engine processors (developed for the Sony PlayStation 3), and planned simulation studies of ejecta and spall failure in polycrystalline metals that will be carried out when the full Petaflop Opteron/Cell Roadrunner supercomputer is assembled in mid-2008.

  4. Basin Contributions to the Stratigraphy of the Apollo 16 Landing Site

    Science.gov (United States)

    Haskin, Larry A.

    2001-01-01

    Ejecta deposit modeling suggests that the megaregolith at the Apollo 16 landing site is dominated by Imbrium and Serenitatis ejecta, and Nectaris ejecta are a minor componen Additional information is contained in the original extended abstract.t.

  5. NEUTRON-STAR MERGER EJECTA AS OBSTACLES TO NEUTRINO-POWERED JETS OF GAMMA-RAY BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Just, O.; Janka, H.-T.; Schwarz, N. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Obergaulinger, M. [Departament d´Astronomia i Astrofísica, Universitat de València, Edifici d´Investigació Jeroni Muñoz, C/ Dr. Moliner, 50, E-46100 Burjassot (València) (Spain); Bauswein, A., E-mail: ojust@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2016-01-10

    We present the first special relativistic, axisymmetric hydrodynamic simulations of black hole-torus systems (approximating general relativistic gravity) as remnants of binary-neutron star (NS–NS) and neutron star–black hole (NS–BH) mergers, in which the viscously driven evolution of the accretion torus is followed with self-consistent energy-dependent neutrino transport and the interaction with the cloud of dynamical ejecta expelled during the NS–NS merging is taken into account. The modeled torus masses, BH masses and spins, and the ejecta masses, velocities, and spatial distributions are adopted from relativistic merger simulations. We find that energy deposition by neutrino annihilation can accelerate outflows with initially high Lorentz factors along polar low-density funnels, but only in mergers with extremely low baryon pollution in the polar regions. NS–BH mergers, where polar mass ejection during the merging phase is absent, provide sufficiently baryon-poor environments to enable neutrino-powered, ultrarelativistic jets with terminal Lorentz factors above 100 and considerable dynamical collimation, favoring short gamma-ray bursts (sGRBs), although their typical energies and durations might be too small to explain the majority of events. In the case of NS–NS mergers, however, neutrino emission of the accreting and viscously spreading torus is too short and too weak to yield enough energy for the outflows to break out from the surrounding ejecta shell as highly relativistic jets. We conclude that neutrino annihilation alone cannot power sGRBs from NS–NS mergers.

  6. NEUTRON-STAR MERGER EJECTA AS OBSTACLES TO NEUTRINO-POWERED JETS OF GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Just, O.; Janka, H.-T.; Schwarz, N.; Obergaulinger, M.; Bauswein, A.

    2016-01-01

    We present the first special relativistic, axisymmetric hydrodynamic simulations of black hole-torus systems (approximating general relativistic gravity) as remnants of binary-neutron star (NS–NS) and neutron star–black hole (NS–BH) mergers, in which the viscously driven evolution of the accretion torus is followed with self-consistent energy-dependent neutrino transport and the interaction with the cloud of dynamical ejecta expelled during the NS–NS merging is taken into account. The modeled torus masses, BH masses and spins, and the ejecta masses, velocities, and spatial distributions are adopted from relativistic merger simulations. We find that energy deposition by neutrino annihilation can accelerate outflows with initially high Lorentz factors along polar low-density funnels, but only in mergers with extremely low baryon pollution in the polar regions. NS–BH mergers, where polar mass ejection during the merging phase is absent, provide sufficiently baryon-poor environments to enable neutrino-powered, ultrarelativistic jets with terminal Lorentz factors above 100 and considerable dynamical collimation, favoring short gamma-ray bursts (sGRBs), although their typical energies and durations might be too small to explain the majority of events. In the case of NS–NS mergers, however, neutrino emission of the accreting and viscously spreading torus is too short and too weak to yield enough energy for the outflows to break out from the surrounding ejecta shell as highly relativistic jets. We conclude that neutrino annihilation alone cannot power sGRBs from NS–NS mergers

  7. Monturaqui meteorite impact crater, Chile: A field test of the utility of satellite-based mapping of ejecta at small craters

    Science.gov (United States)

    Rathbun, K.; Ukstins, I.; Drop, S.

    2017-12-01

    Monturaqui Crater is a small ( 350 m diameter), simple meteorite impact crater located in the Atacama Desert of northern Chile that was emplaced in Ordovician granite overlain by discontinuous Pliocene ignimbrite. Ejecta deposits are granite and ignimbrite, with lesser amounts of dark impact melt and rare tektites and iron shale. The impact restructured existing drainage systems in the area that have subsequently eroded through the ejecta. Satellite-based mapping and modeling, including a synthesis of photographic satellite imagery and ASTER thermal infrared imagery in ArcGIS, were used to construct a basic geological interpretation of the site with special emphasis on understanding ejecta distribution patterns. This was combined with field-based mapping to construct a high-resolution geologic map of the crater and its ejecta blanket and field check the satellite-based geologic interpretation. The satellite- and modeling-based interpretation suggests a well-preserved crater with an intact, heterogeneous ejecta blanket that has been subjected to moderate erosion. In contrast, field mapping shows that the crater has a heavily-eroded rim and ejecta blanket, and the ejecta is more heterogeneous than previously thought. In addition, the erosion rate at Monturaqui is much higher than erosion rates reported elsewhere in the Atacama Desert. The bulk compositions of the target rocks at Monturaqui are similar and the ejecta deposits are highly heterogeneous, so distinguishing between them with remote sensing is less effective than with direct field observations. In particular, the resolution of available imagery for the site is too low to resolve critical details that are readily apparent in the field on the scale of 10s of cm, and which significantly alter the geologic interpretation. The limiting factors for effective remote interpretation at Monturaqui are its target composition and crater size relative to the resolution of the remote sensing methods employed. This

  8. Detectability Factors for Earth-based Imaging of the LCROSS Ejecta Plume

    Science.gov (United States)

    Strycker, Paul D.; Schotte, Jonathan M.; Temme, Ruth L.; Chanover, Nancy J.

    2017-10-01

    NASA’s Lunar Crater Observation and Sensing Satellite (LCROSS) mission delivered a kinetic impactor into Cabeus Crater on 9 October 2009 [1, 2]. Observing campaigns from Earth-based telescopes at multiple facilities attempted to obtain temporally-resolved imaging of the ejecta plume [3], but no Earth-based imaging detections were reported until 2013 after processing images with Principal Component Analysis (PCA) filtering [4]. Subsequently, PCA filtering has revealed plume detections in two additional cameras and also confirmed a non-detection from one telescope [5, 6]. This combination of detection and non-detection data is useful in determining the criteria for detectability in future observations of transient events. The goal of this work is to identify factors contributing to detectability and to establish thresholds applicable to the LCROSS event. We take the data containing detections and then degrade a specific factor in them until the plume is no longer detectable. These derived thresholds for factors (e.g., scattered light, temporal resolution, spatial resolution, field of view, and signal-to-noise of the illuminated foreground of Cabeus) can be compared to the properties of the actual non-detection data to identify problems specific to its observing conditions or observational setup. The percent differences between the thresholds and both the detection data and non-detection data may also reveal the relative importance of these detectability factors. This work was supported by NASA’s Lunar Data Analysis Program through grant number NNX15AP92G. Observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.References: [1] Colaprete, A. et al. (2010) Science, 330, 463-468. [2] Schultz, P. H. et al. (2010) Science, 330, 468-472. [3] Heldmann, J. L. et al. (2012) Space Sci. Rev., 167:93-140, doi:10.1007/s11214-011-9759-y. [4] Strycker, P. D. et al. (2013) Nat. Commun., 4

  9. Method to prevent ejecta from damaging the Compact Torus Accelerator driver of an inertial fusion energy power plant

    International Nuclear Information System (INIS)

    Mattingly, S.E.K.; Moir, R.W.

    1992-01-01

    Concern has been expressed about the conceptual design of fusion reactors using a Compact Torus Accelerator (CTA). A CTA accelerates a plasma torus toward a fusion target. When the torus nears the target, it is compressed and focused down to a small volume, creating a very high energy density and initiating a fusion micro explosion. The focusing cone is destroyed with each shot due to the stress from the passage of the torus as well as from the force of the explosion (1 800 MJ of yield, ∼0.5 Ton TNT equivalent). The focusing cone could be made of solidified Li 2 BeF 4 ; the same material used in liquid state to protect the reaction chamber from the micro explosion and to transport heat away to a power plant. The problem with this design is that when the focusing cone is shattered, the resulting small pieces of solid and liquid debris (ejecta) might be carded along by the expanding vapor of the explosion and might enter the CTA itself, causing damage and shortening the life of the CTA. The proposed solution for this possible problem is to bend the focusing cone so that the ejecta no longer have a clear path to the CTA. Calculations show that the plasma torus may be sent through a radius of curvature of less than 0.5 m just after the focusing cone, without significantly disturbing the plasma

  10. Zhamanshin astrobleme provides evidence for carbonaceous chondrite and post-impact exchange between ejecta and Earth's atmosphere.

    Science.gov (United States)

    Magna, Tomáš; Žák, Karel; Pack, Andreas; Moynier, Frédéric; Mougel, Bérengère; Peters, Stefan; Skála, Roman; Jonášová, Šárka; Mizera, Jiří; Řanda, Zdeněk

    2017-08-09

    Chemical fingerprints of impacts are usually compromised by extreme conditions in the impact plume, and the contribution of projectile matter to impactites does not often exceed a fraction of per cent. Here we use chromium and oxygen isotopes to identify the impactor and impact-plume processes for Zhamanshin astrobleme, Kazakhstan. ε 54 Cr values up to 1.54 in irghizites, part of the fallback ejecta, represent the 54 Cr-rich extremity of the Solar System range and suggest a CI-like chondrite impactor. Δ 17 O values as low as -0.22‰ in irghizites, however, are incompatible with a CI-like impactor. We suggest that the observed 17 O depletion in irghizites relative to the terrestrial range is caused by partial isotope exchange with atmospheric oxygen (Δ 17 O = -0.47‰) following material ejection. In contrast, combined Δ 17 O-ε 54 Cr data for central European tektites (distal ejecta) fall into the terrestrial range and neither impactor fingerprint nor oxygen isotope exchange with the atmosphere are indicated.Identifying the original impactor from craters remains challenging. Here, the authors use chromium and oxygen isotopes to indicate that the Zhamanshin astrobleme impactor was a carbonaceous chrondrite by demonstrating that depleted 17O values are due to exchange with atmospheric oxygen.

  11. Infrared Spectroscopic Studies of the Properties of Dust in the Ejecta of Galactic Oxygen-Rich Asymptotic Giant Branch Stars

    Science.gov (United States)

    Sargent, Benjamin A.; Srinivasan, Sundar; Kastner, Joel; Meixner, Margaret; Riley, Allyssa

    2018-06-01

    We are conducting a series of infrared studies of large samples of mass-losing asymptotic giant branch (AGB) stars to explore the relationship between the composition of evolved star ejecta and host galaxy metallicity. Our previous studies focused on mass loss from evolved stars in the relatively low-metallicity Large and Small Magellanic Clouds. In our present study, we analyze dust in the mass-losing envelopes of AGB stars in the Galaxy, with special focus on the ejecta of oxygen-rich (O-rich) AGB stars. We have constructed detailed dust opacity models of AGB stars in the Galaxy for which we have infrared spectra from, e.g., the Spitzer Space Telescope Infrared Spectrograph (IRS). This detailed modeling of dust features in IRS spectra informs our choice of dust properties to use in radiative transfer modeling of the broadband SEDs of Bulge AGB stars. We investigate the effects of dust grain composition, size, shape, etc. on the AGB stars' infrared spectra, studying both the silicate dust and the opacity source(s) commonly attributed to alumina (Al2O3). BAS acknowledges funding from NASA ADAP grant 80NSSC17K0057.

  12. Persistent X-Ray Emission from ASASSN-15lh: Massive Ejecta and Pre-SLSN Dense Wind?

    Science.gov (United States)

    Huang, Yan; Li, Zhuo

    2018-06-01

    The persistent soft X-ray emission from the location of the most luminous supernova (SN) so far, ASASSN-15lh (or SN 2015L), with L∼ {10}42 {erg} {{{s}}}-1, is puzzling. We show that it can be explained by radiation from electrons accelerated by the SN shock inverse-Compton scattering the intense UV photons. The non-detection in radio requires strong free–free absorption in the dense medium. In these interpretations, the circumstellar medium is derived to be a wind (n ∝ R ‑2) with mass-loss rate of \\dot{{M}}≳ 3× {10}-3{{M}}ȯ ({{v}}{{w}}/{10}3 {{k}}{{m}} {{{s}}}-1) {{{y}}{{r}}}-1, and the initial velocity of the bulk SN ejecta is ≲ 0.02c. These constraints imply a massive ejecta mass of ≳ 60({E}0/2× {10}52 {erg}){M}ȯ in ASASSN-15lh, and a strong wind ejected by the progenitor star within ∼ 8{({v}{{w}}/{10}3{km}{{{s}}}-1)}-1 yr before explosion.

  13. MODELING SNR CASSIOPEIA A FROM THE SUPERNOVA EXPLOSION TO ITS CURRENT AGE: THE ROLE OF POST-EXPLOSION ANISOTROPIES OF EJECTA

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F., E-mail: orlando@astropa.inaf.it [INAF—Osservatorio Astronomico di Palermo “G.S. Vaiana,” Piazza del Parlamento 1, I-90134 Palermo (Italy)

    2016-05-01

    The remnants of core-collapse supernovae (SNe) have complex morphologies that may reflect asymmetries and structures developed during the progenitor SN explosion. Here we investigate how the morphology of the supernova remnant Cassiopeia A (Cas A) reflects the characteristics of the progenitor SN with the aim of deriving the energies and masses of the post-explosion anisotropies responsible for the observed spatial distribution of Fe and Si/S. We model the evolution of Cas A from the immediate aftermath of the progenitor SN to the three-dimensional interaction of the remnant with the surrounding medium. The post-explosion structure of the ejecta is described by small-scale clumping of material and larger-scale anisotropies. The hydrodynamic multi-species simulations consider an appropriate post-explosion isotopic composition of the ejecta. The observed average expansion rate and shock velocities can be well reproduced by models with ejecta mass M {sub ej} ≈ 4 M {sub ⊙} and explosion energy E {sub SN} ≈ 2.3 × 10{sup 51} erg. The post-explosion anisotropies (pistons) reproduce the observed distributions of Fe and Si/S if they had a total mass of ≈0.25 M {sub ⊙} and a total kinetic energy of ≈1.5 × 10{sup 50} erg. The pistons produce a spatial inversion of ejecta layers at the epoch of Cas A, leading to the Si/S-rich ejecta physically interior to the Fe-rich ejecta. The pistons are also responsible for the development of the bright rings of Si/S-rich material which form at the intersection between the reverse shock and the material accumulated around the pistons during their propagation. Our result supports the idea that the bulk of asymmetries observed in Cas A are intrinsic to the explosion.

  14. Computer simulations of large asteroid impacts into oceanic and continental sites--preliminary results on atmospheric, cratering and ejecta dynamics

    Science.gov (United States)

    Roddy, D.J.; Schuster, S.H.; Rosenblatt, M.; Grant, L.B.; Hassig, P.J.; Kreyenhagen, K.N.

    1987-01-01

    Computer simulations have been completed that describe passage of a 10-km-diameter asteroid through the Earth's atmosphere and the subsequent cratering and ejecta dynamics caused by impact of the asteroid into both oceanic and continental sites. The asteroid was modeled as a spherical body moving vertically at 20 km/s with a kinetic energy of 2.6 ?? 1030 ergs (6.2 ?? 107 Mt ). Detailed material modeling of the asteroid, ocean, crustal units, sedimentary unit, and mantle included effects of strength and fracturing, generic asteroid and rock properties, porosity, saturation, lithostatic stresses, and geothermal contributions, each selected to simulate impact and geologic conditions that were as realistic as possible. Calculation of the passage of the asteroid through a U.S. Standard Atmosphere showed development of a strong bow shock wave followed by a highly shock compressed and heated air mass. Rapid expansion of this shocked air created a large low-density region that also expanded away from the impact area. Shock temperatures in air reached ???20,000 K near the surface of the uplifting crater rim and were as high as ???2000 K at more than 30 km range and 10 km altitude. Calculations to 30 s showed that the shock fronts in the air and in most of the expanding shocked air mass preceded the formation of the crater, ejecta, and rim uplift and did not interact with them. As cratering developed, uplifted rim and target material were ejected into the very low density, shock-heated air immediately above the forming crater, and complex interactions could be expected. Calculations of the impact events showed equally dramatic effects on the oceanic and continental targets through an interval of 120 s. Despite geologic differences in the targets, both cratering events developed comparable dynamic flow fields and by ???29 s had formed similar-sized transient craters ???39 km deep and ???62 km across. Transient-rim uplift of ocean and crust reached a maximum altitude of nearly

  15. The Cretaceous-Paleogene transition and Chicxulub impact ejecta in the northwestern Gulf of Mexico: Paleoenvironments, sequence stratigraphic setting and target lithologies

    Science.gov (United States)

    Schulte, Peter

    2003-07-01

    The Cretaceous-Paleogene (K-P) transition is characterized by a period of mass extinctions, the Chicxulub impact event, sea-level changes, and considerable climate changes (e.g., cooling). The Gulf of Mexico region is a key area for addressing these issues, specifically because of the proximity to the large Chicxulub impact structure in southern Mexico, and because of its shallow shelf areas throughout the Maastrichtian to Danian period. This study presents the results of a multidisciplinary investigation of Chicxulub impact ejecta and marine sediments from the K-P transition in the western Gulf of Mexico. Sedimentological, mineralogical, and geochemical aspects of K-P sections and cores from northeastern Mexico, Texas, and Alabama have been by studied with focus on Chicxulub ejecta, long- or short-term facies change, and sequence stratigraphic setting. CHICXULUB EJECTA: The Chicxulub ejecta (or impact spherule) deposits from northeastern Mexico and Texas revealed an unexpected complex and localized ejecta composition. Fe-Mg-rich chlorite- as well as Si-Al-K-rich glass-spherules are the predominant silicic ejecta components in northeastern Mexico, whereas in Texas, spherules of Mg-rich smectite compositions were encountered. Spherules contain Fe-Ti-K-rich schlieren, Fe-Mg-rich globules, and rare µm-sized metallic and sulfidic Ni-Co-(Ir-?) rich inclusions. This composition provides evidence for a distinct range of target rocks of mafic to intermediate composition, presumably situated in the northwestern sector of the Chicxulub impact structure, in addition to the possibility of contamination by meteoritic material. The absence of spinels and the ubiquitous presence of hematite and goethite points to high oxygen fugacity during the impact process. Besides these silicic phases, the most prominent ejecta component is carbonate.! Carbonate is found in ejecta deposits as unshocked clasts, accretionary lapilli-like grains, melt globules (often with quenching textures

  16. A solar-type star polluted by calcium-rich supernova ejecta inside the supernova remnant RCW 86

    Science.gov (United States)

    Gvaramadze, Vasilii V.; Langer, Norbert; Fossati, Luca; Bock, Douglas C.-J.; Castro, Norberto; Georgiev, Iskren Y.; Greiner, Jochen; Johnston, Simon; Rau, Arne; Tauris, Thomas M.

    2017-06-01

    When a massive star in a binary system explodes as a supernova, its companion star may be polluted with heavy elements from the supernova ejecta. Such pollution has been detected in a handful of post-supernova binaries 1 , but none of them is associated with a supernova remnant. We report the discovery of a binary G star strongly polluted with calcium and other elements at the position of the candidate neutron star [GV2003] N within the young galactic supernova remnant RCW 86. Our discovery suggests that the progenitor of the supernova that produced RCW 86 could have been a moving star, which exploded near the edge of its wind bubble and lost most of its initial mass because of common-envelope evolution shortly before core collapse, and that the supernova explosion might belong to the class of calcium-rich supernovae — faint and fast transients 2,3 , the origin of which is strongly debated 4-6 .

  17. Hitomi observations of the LMC SNR N 132 D: Highly redshifted X-ray emission from iron ejecta

    Science.gov (United States)

    Hitomi Collaboration; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steven W.; Angelini, Lorella; Audard, Marc; Awaki, Hisamitsu; Axelsson, Magnus; Bamba, Aya; Bautz, Marshall W.; Blandford, Roger; Brenneman, Laura W.; Brown, Gregory V.; Bulbul, Esra; Cackett, Edward M.; Chernyakova, Maria; Chiao, Meng P.; Coppi, Paolo S.; Costantini, Elisa; de Plaa, Jelle; de Vries, Cor P.; den Herder, Jan-Willem; Done, Chris; Dotani, Tadayasu; Ebisawa, Ken; Eckart, Megan E.; Enoto, Teruaki; Ezoe, Yuichiro; Fabian, Andrew C.; Ferrigno, Carlo; Foster, Adam R.; Fujimoto, Ryuichi; Fukazawa, Yasushi; Furuzawa, Akihiro; Galeazzi, Massimiliano; Gallo, Luigi C.; Gandhi, Poshak; Giustini, Margherita; Goldwurm, Andrea; Gu, Liyi; Guainazzi, Matteo; Haba, Yoshito; Hagino, Kouichi; Hamaguchi, Kenji; Harrus, Ilana M.; Hatsukade, Isamu; Hayashi, Katsuhiro; Hayashi, Takayuki; Hayashida, Kiyoshi; Hiraga, Junko S.; Hornschemeier, Ann; Hoshino, Akio; Hughes, John P.; Ichinohe, Yuto; Iizuka, Ryo; Inoue, Hajime; Inoue, Yoshiyuki; Ishida, Manabu; Ishikawa, Kumi; Ishisaki, Yoshitaka; Iwai, Masachika; Kaastra, Jelle; Kallman, Tim; Kamae, Tsuneyoshi; Kataoka, Jun; Katsuda, Satoru; Kawai, Nobuyuki; Kelley, Richard L.; Kilbourne, Caroline A.; Kitaguchi, Takao; Kitamoto, Shunji; Kitayama, Tetsu; Kohmura, Takayoshi; Kokubun, Motohide; Koyama, Katsuji; Koyama, Shu; Kretschmar, Peter; Krimm, Hans A.; Kubota, Aya; Kunieda, Hideyo; Laurent, Philippe; Lee, Shiu-Hang; Leutenegger, Maurice A.; Limousin, Olivier; Loewenstein, Michael; Long, Knox S.; Lumb, David; Madejski, Greg; Maeda, Yoshitomo; Maier, Daniel; Makishima, Kazuo; Markevitch, Maxim; Matsumoto, Hironori; Matsushita, Kyoko; McCammon, Dan; McNamara, Brian R.; Mehdipour, Missagh; Miller, Eric D.; Miller, Jon M.; Mineshige, Shin; Mitsuda, Kazuhisa; Mitsuishi, Ikuyuki; Miyazawa, Takuya; Mizuno, Tsunefumi; Mori, Hideyuki; Mori, Koji; Mukai, Koji; Murakami, Hiroshi; Mushotzky, Richard F.; Nakagawa, Takao; Nakajima, Hiroshi; Nakamori, Takeshi; Nakashima, Shinya; Nakazawa, Kazuhiro; Nobukawa, Kumiko K.; Nobukawa, Masayoshi; Noda, Hirofumi; Odaka, Hirokazu; Ohashi, Takaya; Ohno, Masanori; Okajima, Takashi; Ota, Naomi; Ozaki, Masanobu; Paerels, Frits; Paltani, Stéphane; Petre, Robert; Pinto, Ciro; Porter, Frederick S.; Pottschmidt, Katja; Reynolds, Christopher S.; Safi-Harb, Samar; Saito, Shinya; Sakai, Kazuhiro; Sasaki, Toru; Sato, Goro; Sato, Kosuke; Sato, Rie; Sato, Toshiki; Sawada, Makoto; Schartel, Norbert; Serlemtsos, Peter J.; Seta, Hiromi; Shidatsu, Megumi; Simionescu, Aurora; Smith, Randall K.; Soong, Yang; Stawarz, Łukasz; Sugawara, Yasuharu; Sugita, Satoshi; Szymkowiak, Andrew; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Takei, Yoh; Tamagawa, Toru; Tamura, Takayuki; Tanaka, Takaaki; Tanaka, Yasuo; Tanaka, Yasuyuki T.; Tashiro, Makoto S.; Tawara, Yuzuru; Terada, Yukikatsu; Terashima, Yuichi; Tombesi, Francesco; Tomida, Hiroshi; Tsuboi, Yohko; Tsujimoto, Masahiro; Tsunemi, Hiroshi; Tsuru, Takeshi Go; Uchida, Hiroyuki; Uchiyama, Hideki; Uchiyama, Yasunobu; Ueda, Shutaro; Ueda, Yoshihiro; Uno, Shin'ichiro; Urry, C. Megan; Ursino, Eugenio; Watanabe, Shin; Werner, Norbert; Wilkins, Dan R.; Williams, Brian J.; Yamada, Shinya; Yamaguchi, Hiroya; Yamaoka, Kazutaka; Yamasaki, Noriko Y.; Yamauchi, Makoto; Yamauchi, Shigeo; Yaqoob, Tahir; Yatsu, Yoichi; Yonetoku, Daisuke; Zhuravleva, Irina; Zoghbi, Abderahmen

    2018-03-01

    We present Hitomi observations of N 132 D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at ˜ 800 km s-1 compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km s-1 if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blueshifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of ˜ 1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena.

  18. On the history of the early meteoritic bombardment of the Moon: Was there a terminal lunar cataclysm?

    Science.gov (United States)

    Michael, Greg; Basilevsky, Alexander; Neukum, Gerhard

    2018-03-01

    the considered histograms and relative probability plots not only the 3.87 Ga peak (due to Imbrium basin), but also several secondary peaks caused by the formation of other basins distributed between 3.87 and 4.25 Ga. The lunar terminal cataclysm hypothesis is in disagreement with the distribution of K-Ar ages for the highland rocks of the lunar meteorites. The population of lunar meteorites representing localities randomly distributed over the lunar surface, and thus free from the mentioned sampling bias, shows no ∼3.9 Ga peak as it should, if the cataclysm did occur. We conclude that the statistics of sample ages contradict the terminal cataclysm scenario in the bombardment of the Moon. We also see evidence for the formation of several impact basins between 3.87 and 4.25 Ga which is likewise incompatible with the hypothesis of a short interval cataclysm. There remain other basins, including the largest South Pole - Aitken, the ages of which should be determined in future studies to further clarify the impact history. Sample-return missions targeted to date several key basins need to be planned, and the continued study of lunar meteorites may also bring new details to the general view of the impact bombardment of the Moon.

  19. Digging Deep: Is Lunar Mantle Excavated Around the Imbrium Basin?

    Science.gov (United States)

    Klima, R. L.; Bretzfelder, J.; Buczkowski, D.; Ernst, C. M.; Greenhagen, B. T.; Petro, N. E.; Shusterman, M. L.

    2017-12-01

    The Moon has experienced over a dozen impacts resulting in basins large enough to have excavated mantle material. With many of those basins concentrated on the lunar near side, and extensive regolith mixing since the lunar magma ocean crystallized, one might expect that some mantle material would have been found among the lunar samples on Earth. However, so far, no mantle clasts have been definitively identified in lunar samples [1]. From orbit, a number of olivine-bearing localities, potentially sourced from the mantle, have been identified around impact basins [2]. Based on analysis of near-infrared (NIR) and imaging data, [3] suggest that roughly 60% of these sites represent olivine from the mantle. If this is the case and the blocks are coherent and not extensively mixed into the regolith, these deposits should be ultramafic, containing olivine and/or pyroxenes and little to no plagioclase. In the mid-infrared, they would thus exhibit Christiansen features at wavelengths in excess of 8.5 μm, which has not been observed in global studies using the Diviner Lunar Radiometer [4]. We present an integrated study of the massifs surrounding the Imbrium basin, which, at over 1000 km wide, is large enough to have penetrated through the lunar crust and into the mantle. These massifs are clearly associated with the Imbrium basin-forming impact, but existing geological maps do not distinguish between whether they are likely ejecta or rather uplifted from beneath the surface during crustal rebound [5]. We examine these massifs using vis, NIR and Mid IR data to determine the relationships between and the bulk mineralogy of local lithologies. NIR data suggest that the massifs contain exposures of four dominant minerals: olivine, Mg-rich orthopyroxene, a second low-Ca pyroxene, and anorthite. Mid IR results suggest that though many of these massifs are plagioclase-rich, portions of some may be significantly more mafic. We will present our growing mineralogical map of the

  20. Ring faults and ring dikes around the Orientale basin on the Moon.

    Science.gov (United States)

    Andrews-Hanna, Jeffrey C; Head, James W; Johnson, Brandon; Keane, James T; Kiefer, Walter S; McGovern, Patrick J; Neumann, Gregory A; Wieczorek, Mark A; Zuber, Maria T

    2018-08-01

    The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.

  1. Nano particles as the primary cause for long-term sunlight suppression at high southern latitudes following the Chicxulub impact - evidence from ejecta deposits in Belize and Mexico

    DEFF Research Database (Denmark)

    Vajda, Vivi; Ocampo, Adriana; Ferrow, Embaie

    2015-01-01

    deposits occur in Belize and southern Mexico where the so called Albion island spheroid bed is superimposed on the target rock (the Barton Creek Formation). We analysed the spheroid bed via Mössbauer spectroscopy, petrology, XRD, and palynology at several sites ~ 350-500 km distance from the crater centre....... Our results show that the relative concentrations of Fe in nano-phase goethite (α-FeOOH) are very high in the spheroid bed samples from Albion Island (Belize) and from Ramonal South (Mexico), but are low to absent in the spheroid bed at Ramonal North, and in the Cretaceous target rock. Moreover, our......Life on Earth was sharply disrupted 66 Ma ago as an asteroid hit the sea-floor in what is today Yucatan Peninsula, Mexico. Approximately 600 km3 of sedimentary rock were vapourized, ejected into the atmosphere and subsequently deposited globally as an ejecta apron and fallout layer. Proximal ejecta...

  2. Dynamics of Large-Scale Solar-Wind Streams Obtained by the Double Superposed Epoch Analysis: 2. Comparisons of CIRs vs. Sheaths and MCs vs. Ejecta

    Science.gov (United States)

    Yermolaev, Y. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Y.

    2017-12-01

    This work is a continuation of our previous article (Yermolaev et al. in J. Geophys. Res. 120, 7094, 2015), which describes the average temporal profiles of interplanetary plasma and field parameters in large-scale solar-wind (SW) streams: corotating interaction regions (CIRs), interplanetary coronal mass ejections (ICMEs including both magnetic clouds (MCs) and ejecta), and sheaths as well as interplanetary shocks (ISs). As in the previous article, we use the data of the OMNI database, our catalog of large-scale solar-wind phenomena during 1976 - 2000 (Yermolaev et al. in Cosmic Res., 47, 2, 81, 2009) and the method of double superposed epoch analysis (Yermolaev et al. in Ann. Geophys., 28, 2177, 2010a). We rescale the duration of all types of structures in such a way that the beginnings and endings for all of them coincide. We present new detailed results comparing pair phenomena: 1) both types of compression regions ( i.e. CIRs vs. sheaths) and 2) both types of ICMEs (MCs vs. ejecta). The obtained data allow us to suggest that the formation of the two types of compression regions responds to the same physical mechanism, regardless of the type of piston (high-speed stream (HSS) or ICME); the differences are connected to the geometry ( i.e. the angle between the speed gradient in front of the piston and the satellite trajectory) and the jumps in speed at the edges of the compression regions. In our opinion, one of the possible reasons behind the observed differences in the parameters in MCs and ejecta is that when ejecta are observed, the satellite passes farther from the nose of the area of ICME than when MCs are observed.

  3. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. III. Optical and UV Spectra of a Blue Kilonova from Fast Polar Ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Nicholl, M.; Berger, E.; Kasen, D.; Metzger, B. D.; Elias, J.; Briceño, C.; Alexander, K. D.; Blanchard, P. K.; Chornock, R.; Cowperthwaite, P. S.; Eftekhari, T.; Fong, W.; Margutti, R.; Villar, V. A.; Williams, P. K. G.; Brown, W.; Annis, J.; Bahramian, A.; Brout, D.; Brown, D. A.; Chen, H. -Y.; Clemens, J. C.; Dennihy, E.; Dunlap, B.; Holz, D. E.; Marchesini, E.; Massaro, F.; Moskowitz, N.; Pelisoli, I.; Rest, A.; Ricci, F.; Sako, M.; Soares-Santos, M.; Strader, J.

    2017-10-16

    We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational wave (GW) source, the binary neutron star merger GW170817. Spectra were obtained nightly between 1.5 and 9.5 days post-merger, using the SOAR and Magellan telescopes; the UV spectrum was obtained with the \\textit{Hubble Space Telescope} at 5.5 days. Our data reveal a rapidly-fading blue component ($T\\approx5500$ K at 1.5 days) that quickly reddens; spectra later than $\\gtrsim 4.5$ days peak beyond the optical regime. The spectra are mostly featureless, although we identify a possible weak emission line at $\\sim 7900$ \\AA\\ at $t\\lesssim 4.5$ days. The colours, rapid evolution and featureless spectrum are consistent with a "blue" kilonova from polar ejecta comprised mainly of light $r$-process nuclei with atomic mass number $A\\lesssim 140$. This indicates a sight-line within $\\theta_{\\rm obs}\\lesssim 45^{\\circ}$ of the orbital axis. Comparison to models suggests $\\sim0.03$ M$_\\odot$ of blue ejecta, with a velocity of $\\sim 0.3c$. The required lanthanide fraction is $\\sim 10^{-4}$, but this drops to $<10^{-5}$ in the outermost ejecta. The large velocities point to a dynamical origin, rather than a disk wind, for this blue component, suggesting that both binary constituents are neutron stars (as opposed to a binary consisting of a neutron star and a black hole). For dynamical ejecta, the high mass favors a small neutron star radius of $\\lesssim 12$ km. This mass also supports the idea that neutron star mergers are a major contributor to $r$-process nucleosynthesis.

  4. 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

  5. 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.

  6. 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...

  7. PDV-based estimation of ejecta particles' mass-velocity function from shock-loaded tin experiment

    Science.gov (United States)

    Franzkowiak, J.-E.; Prudhomme, G.; Mercier, P.; Lauriot, S.; Dubreuil, E.; Berthe, L.

    2018-03-01

    A metallic tin plate with a given surface finish of wavelength λ ≃ 60 μm and amplitude h ≃ 8 μm is explosively driven by an electro-detonator with a shock-induced breakout pressure PSB = 28 GPa (unsupported). The resulting dynamic fragmentation process, the so-called "micro-jetting," is the creation of high-speed jets of matter moving faster than the bulk metallic surface. Hydrodynamic instabilities result in the fragmentation of these jets into micron-sized metallic particles constituting a self-expanding cloud of droplets, whose areal mass, velocity, and particle size distributions are unknown. Lithium-niobate-piezoelectric sensor measured areal mass and Photonic Doppler Velocimetry (PDV) was used to get a time-velocity spectrogram of the cloud. In this article, we present both experimental mass and velocity results and we relate the integrated areal mass of the cloud to the PDV power spectral density with the assumption of a power law particle size distribution. Two models of PDV spectrograms are described. The first one accounts for the speckle statistics of the spectrum and the second one describes an average spectrum for which speckle fluctuations are removed. Finally, the second model is used for a maximum likelihood estimation of the cloud's parameters from PDV data. The estimated integrated areal mass from PDV data is found to agree well with piezoelectric results. We highlight the relevance of analyzing PDV data and correlating different diagnostics to retrieve the physical properties of ejecta particles.

  8. PDV-based estimation of high-speed ejecta particles density from shock-loaded tin plate

    Science.gov (United States)

    Franzkowiak, Jean-Eloi; Prudhomme, Gabriel; Mercier, Patrick; Lauriot, Séverine; Dubreuil, Estelle; Berthe, Laurent

    2017-06-01

    A machine-grooved metallic tin surface is explosively driven by a detonator with a shock-induced pressure of 25 GPa. The resulting dynamic fragmentation process called micro-jetting is the creation of high-speed jets of matter moving faster than the bulk metallic surface. The resulting fragmentation into micron-sized metallic particles generates a self-expanding cloud of droplets, whose areal mass, velocity and size distributions are unknown. Lithium-Niobate (LN) piezoelectric pin measured areal mass and Photonic Doppler Velocimetry (PDV) was employed to get a time-velocity spectrogram of the cloud. We present both experimental mass and velocity results and relate the integrated areal mass of the cloud to the PDV power spectral density under the assumption of a power law distribution for particle sizes. A model of PDV spectrograms is described, for which speckle fluctuations are averaged out. Finally, we use our model for a Maximum Likelihood Estimation of the cloud's parameters from PDV data. The integrated areal mass deduced from the PDV analysis is in good agreement with piezoelectric results. We underline the relevance of analyzing PDV data and correlating different diagnostics to retrieve the macro-physical properties of ejecta particles.

  9. A DETAILED STUDY OF SPITZER-IRAC EMISSION IN HERBIG-HARO OBJECTS. II. INTERACTION BETWEEN EJECTA AND AMBIENT GAS

    International Nuclear Information System (INIS)

    Takami, Michihiro; Karr, Jennifer L.; Nisini, Brunella; Ray, Thomas P.

    2011-01-01

    We present a new analysis of the physical conditions in three Herbig-Haro complexes (HH 54, HH 212, and the L 1157 protostellar jet) using archival data from the Infrared Array Camera on the Spitzer Space Telescope. As described in detail in Paper I, the emission observed using the 4.5 μm filter is enhanced in molecular shocks (T = 1000-4000 K) at relatively high temperatures or densities compared with that observed with the 8.0 μm filter. Using these data sets, we investigate different distributions of gas between high and low temperatures/densities. Our analysis reveals the presence of a number of warm/dense knots, most of which appear to be associated with working surfaces such as the head of bow shocks and cometary features, and reverse shocks in the ejecta. These are distributed not only along the jet axis, as expected, but also across it. While some knotty or fragmenting structures can be explained by instabilities in shocked flows, others can be more simply explained by the scenario that the mass ejection source acts as a 'shot gun', periodically ejecting bullets of material along similar but not identical trajectories. Such an explanation challenges to some degree the present paradigm for jet flows associated with low-mass protostars. It also gives clues to reconciling our understanding of the mass ejection mechanism in high- and low-mass protostars and evolved stars.

  10. 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

  11. 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).

  12. 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.

  13. Watershed Planning Basins

    Data.gov (United States)

    Vermont Center for Geographic Information — The Watershed Planning Basin layer is part of a larger dataset contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  14. BASINS Framework and Features

    Science.gov (United States)

    BASINS enables users to efficiently access nationwide environmental databases and local user-specified datasets, apply assessment and planning tools, and run a variety of proven nonpoint loading and water quality models within a single GIS format.

  15. K Basin Hazard Analysis

    International Nuclear Information System (INIS)

    PECH, S.H.

    2000-01-01

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  16. K Basin Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    PECH, S.H.

    2000-08-23

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  17. K Basins Hazard Analysis

    International Nuclear Information System (INIS)

    WEBB, R.H.

    1999-01-01

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062/Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  18. Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

    International Nuclear Information System (INIS)

    Durand, O.; Soulard, L.

    2013-01-01

    Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10 8 atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle

  19. Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

    Energy Technology Data Exchange (ETDEWEB)

    Durand, O.; Soulard, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2013-11-21

    Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10{sup 8} atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle.

  20. Early Observations of the Type Ia Supernova iPTF 16abc: A Case of Interaction with Nearby, Unbound Material and/or Strong Ejecta Mixing

    Science.gov (United States)

    Miller, A. A.; Cao, Y.; Piro, A. L.; Blagorodnova, N.; Bue, B. D.; Cenko, S. B.; Dhawan, S.; Ferretti, R.; Fox, O. D.; Fremling, C.; Goobar, A.; Howell, D. A.; Hosseinzadeh, G.; Kasliwal, M. M.; Laher, R. R.; Lunnan, R.; Masci, F. J.; McCully, C.; Nugent, P. E.; Sollerman, J.; Taddia, F.; Kulkarni, S. R.

    2018-01-01

    Early observations of Type Ia supernovae (SNe Ia) provide a unique probe of their progenitor systems and explosion physics. Here we report the intermediate Palomar Transient Factory (iPTF) discovery of an extraordinarily young SN Ia, iPTF 16abc. By fitting a power law to our early light curve, we infer that first light for the SN, that is, when the SN could have first been detected by our survey, occurred only 0.15{+/- }0.070.15 days before our first detection. In the ∼24 hr after discovery, iPTF 16abc rose by ∼2 mag, featuring a near-linear rise in flux for ≳ 3 days. Early spectra show strong C II absorption, which disappears after ∼7 days. Unlike the extensively observed Type Ia SN 2011fe, the {(B-V)}0 colors of iPTF 16abc are blue and nearly constant in the days after explosion. We show that our early observations of iPTF 16abc cannot be explained by either SN shock breakout and the associated, subsequent cooling or the SN ejecta colliding with a stellar companion. Instead, we argue that the early characteristics of iPTF 16abc, including (i) the rapid, near-linear rise, (ii) the nonevolving blue colors, and (iii) the strong C II absorption, are the result of either ejecta interaction with nearby, unbound material or vigorous mixing of radioactive 56Ni in the SN ejecta, or a combination of the two. In the next few years, dozens of very young normal SNe Ia will be discovered, and observations similar to those presented here will constrain the white dwarf explosion mechanism.

  1. SUN-TO-EARTH CHARACTERISTICS OF TWO CORONAL MASS EJECTIONS INTERACTING NEAR 1 AU: FORMATION OF A COMPLEX EJECTA AND GENERATION OF A TWO-STEP GEOMAGNETIC STORM

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying D.; Yang, Zhongwei; Wang, Rui [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Luhmann, Janet G. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Richardson, John D. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Lugaz, Noé, E-mail: liuxying@spaceweather.ac.cn [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)

    2014-10-01

    On 2012 September 30-October 1 the Earth underwent a two-step geomagnetic storm. We examine the Sun-to-Earth characteristics of the coronal mass ejections (CMEs) responsible for the geomagnetic storm with combined heliospheric imaging and in situ observations. The first CME, which occurred on 2012 September 25, is a slow event and shows an acceleration followed by a nearly invariant speed in the whole Sun-Earth space. The second event, launched from the Sun on 2012 September 27, exhibits a quick acceleration, then a rapid deceleration, and finally a nearly constant speed, a typical Sun-to-Earth propagation profile for fast CMEs. These two CMEs interacted near 1 AU as predicted by the heliospheric imaging observations and formed a complex ejecta observed at Wind, with a shock inside that enhanced the pre-existing southward magnetic field. Reconstruction of the complex ejecta with the in situ data indicates an overall left-handed flux-rope-like configuration with an embedded concave-outward shock front, a maximum magnetic field strength deviating from the flux rope axis, and convex-outward field lines ahead of the shock. While the reconstruction results are consistent with the picture of CME-CME interactions, a magnetic cloud-like structure without clear signs of CME interactions is anticipated when the merging process is finished.

  2. SUN-TO-EARTH CHARACTERISTICS OF TWO CORONAL MASS EJECTIONS INTERACTING NEAR 1 AU: FORMATION OF A COMPLEX EJECTA AND GENERATION OF A TWO-STEP GEOMAGNETIC STORM

    International Nuclear Information System (INIS)

    Liu, Ying D.; Yang, Zhongwei; Wang, Rui; Luhmann, Janet G.; Richardson, John D.; Lugaz, Noé

    2014-01-01

    On 2012 September 30-October 1 the Earth underwent a two-step geomagnetic storm. We examine the Sun-to-Earth characteristics of the coronal mass ejections (CMEs) responsible for the geomagnetic storm with combined heliospheric imaging and in situ observations. The first CME, which occurred on 2012 September 25, is a slow event and shows an acceleration followed by a nearly invariant speed in the whole Sun-Earth space. The second event, launched from the Sun on 2012 September 27, exhibits a quick acceleration, then a rapid deceleration, and finally a nearly constant speed, a typical Sun-to-Earth propagation profile for fast CMEs. These two CMEs interacted near 1 AU as predicted by the heliospheric imaging observations and formed a complex ejecta observed at Wind, with a shock inside that enhanced the pre-existing southward magnetic field. Reconstruction of the complex ejecta with the in situ data indicates an overall left-handed flux-rope-like configuration with an embedded concave-outward shock front, a maximum magnetic field strength deviating from the flux rope axis, and convex-outward field lines ahead of the shock. While the reconstruction results are consistent with the picture of CME-CME interactions, a magnetic cloud-like structure without clear signs of CME interactions is anticipated when the merging process is finished

  3. Infrared spectroscopy of the remnant of Nova Sco 2014: a symbiotic star with too little circumstellar matter to decelerate the ejecta

    Science.gov (United States)

    Munari, U.; Banerjee, D. P. K.

    2018-03-01

    Pre-outburst 2MASS and WISE photometry of Nova Sco 2014 (V1534 Sco) has suggested the presence of a cool giant at the location of the nova in the sky. The spectral evolution recorded for the nova did not, however, support a direct partnership because no flash-ionized wind and no deceleration of the ejecta were observed, contrary to the behaviour displayed by other novae which erupted within symbiotic binaries like V407 Cyg or RS Oph. We have therefore obtained 0.8-2.5 μm spectra of the remnant of Nova Sco 2014 in order to ascertain if a cool giant is indeed present and if it is physically associated with the nova. The spectrum shows the presence of a M6III giant, reddened by E(B - V) = 1.20, displaying the typical and narrow emission-line spectrum of a symbiotic star, including He I 1.0830 μm with a deep P-Cyg profile. This makes Nova Sco 2014 a new member of the exclusive club of novae that erupt within a symbiotic binary. Nova Sco 2014 shows that a nova erupting within a symbiotic binary does not always come with a deceleration of the ejecta, contrary to the common belief. Many other similar systems may lay hidden in past novae, especially in those that erupted prior to the release of the 2MASS all-sky infrared survey, which could be profitably cross-matched now against them.

  4. AMIE Camera System on board SMART-1

    Science.gov (United States)

    Josset, J. L.; Beauvivre, S.; Amie Team

    The Advanced Moon micro-Imager Experiment AMIE on board ESA SMART-1 the first European mission to the Moon launched on 27th September 2003 is an imaging system with scientific technical and public outreach oriented objectives The science objectives are to image the Lunar Poles permanent shadow areas ice deposit eternal light crater rims ancient Lunar Non-mare volcanism local spectro-photometry and physical state of the lunar sur-face and to map high latitudes regions south mainly at far side South Pole Aitken basin The technical objectives are to perform a laserlink experiment detec-tion of laser beam emitted by ESA Tenerife ground station flight demonstration of new technologies and on-board autonomy navigation The public outreach and educational objectives are to promote planetary exploration We present the AMIE instrument and perfomances with respect to the first results

  5. First Results at the Moon from the SMART-1 / AMIE Experiment

    Science.gov (United States)

    Josset, J. L.; Beauvivre, S.; AMIE Team

    2005-08-01

    The Advanced Moon micro-Imager Experiment (AMIE), on board ESA SMART-1, the first European mission to the Moon (launched on 27th September 2003), is an imaging system with scientific, technical and public outreach oriented objectives. The science objectives are to image the Lunar South Pole, permanent shadow areas (ice deposit), eternal light (crater rims), ancient Lunar Non-mare volcanism, local spectro-photometry and physical state of the lunar surface, and to map high latitudes regions (south) mainly at far side (South Pole Aitken basin). The technical objectives are to perform a laserlink experiment (detection of laser beam emitted by ESA/Tenerife ground station), flight demonstration of new technologies and on-board autonomy navigation. The public outreach and educational objectives are to promote planetary exploration. We present here the first results obtained during the cruise phase and at the Moon.

  6. Science objectives and first results from the SMART-1/AMIE multicolour micro-camera

    Science.gov (United States)

    Josset, J.-L.; Beauvivre, S.; Cerroni, P.; de Sanctis, M. C.; Pinet, P.; Chevrel, S.; Langevin, Y.; Barucci, M. A.; Plancke, P.; Koschny, D.; Almeida, M.; Sodnik, Z.; Mancuso, S.; Hofmann, B. A.; Muinonen, K.; Shevchenko, V.; Shkuratov, Yu.; Ehrenfreund, P.; Foing, B. H.

    The Advanced Moon micro-Imager Experiment (AMIE), on-board SMART-1, the first European mission to the Moon, is an imaging system with scientific, technical and public outreach objectives. The science objectives are to image the lunar South Pole, permanent shadow areas (ice deposit), eternal light (crater rims), ancient lunar non-mare volcanism, local spectrophotometry and physical state of the lunar surface, and to map high latitudes regions (south) mainly at far side (South Pole Aitken basin). The technical objectives are to perform a Laserlink experiment (detection of laser beam emitted by ESA/Tenerife ground station), flight demonstration of new technologies and on-board autonomy navigation. The public outreach and educational objectives are to promote planetary exploration and space. We present here the first results obtained during the cruise phase.

  7. The Importance of Physical Models for Deriving Dust Masses and Grain Size Distributions in Supernova Ejecta. I. Radiatively Heated Dust in the Crab Nebula

    Science.gov (United States)

    Temim, Tea; Dwek, Eli

    2013-01-01

    Recent far-infrared (IR) observations of supernova remnants (SNRs) have revealed significantly large amounts of newly condensed dust in their ejecta, comparable to the total mass of available refractory elements. The dust masses derived from these observations assume that all the grains of a given species radiate at the same temperature, regardless of the dust heating mechanism or grain radius. In this paper, we derive the dust mass in the ejecta of the Crab Nebula, using a physical model for the heating and radiation from the dust. We adopt a power-law distribution of grain sizes and two different dust compositions (silicates and amorphous carbon), and calculate the heating rate of each dust grain by the radiation from the pulsar wind nebula. We find that the grains attain a continuous range of temperatures, depending on their size and composition. The total mass derived from the best-fit models to the observed IR spectrum is 0.019-0.13 Solar Mass, depending on the assumed grain composition. We find that the power-law size distribution of dust grains is characterized by a power-law index of 3.5-4.0 and a maximum grain size larger than 0.1 micron. The grain sizes and composition are consistent with what is expected for dust grains formed in a Type IIP supernova (SN). Our derived dust mass is at least a factor of two less than the mass reported in previous studies of the Crab Nebula that assumed more simplified two-temperature models. These models also require a larger mass of refractory elements to be locked up in dust than was likely available in the ejecta. The results of this study show that a physical model resulting in a realistic distribution of dust temperatures can constrain the dust properties and affect the derived dust masses. Our study may also have important implications for deriving grain properties and mass estimates in other SNRs and for the ultimate question of whether SNe are major sources of dust in the Galactic interstellar medium and in

  8. 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

  9. The Earth's passage of the April 11, 1997 coronal ejecta: geomagnetic field fluctuations at high and low latitude during northward interplanetary magnetic field conditions

    Directory of Open Access Journals (Sweden)

    S. Lepidi

    1999-10-01

    Full Text Available An analysis of the low frequency geomagnetic field fluctuations at an Antarctic (Terra Nova Bay and a low latitude (L'Aquila, Italy station during the Earth's passage of a coronal ejecta on April 11, 1997 shows that major solar wind pressure variations were followed at both stations by a high fluctuation level. During northward interplanetary magnetic field conditions and when Terra Nova Bay is close to the local geomagnetic noon, coherent fluctuations, at the same frequency (3.6 mHz and with polarization characteristics indicating an antisunward propagation, were observed simultaneously at the two stations. An analysis of simultaneous measurements from geosynchronous satellites shows evidence for pulsations at approximately the same frequencies also in the magnetospheric field. The observed waves might then be interpreted as oscillation modes, triggered by an external stimulation, extending to a major portion of the Earth's magnetosphere. Key words. Magnetospheric physics (MHD waves and instabilities; solar wind-magnetosphere interactions

  10. Transport dynamics calculated under the full Mie scattering theory for micron and submicron lunar ejecta in selenocentric, cislunar, and geocentric space

    Science.gov (United States)

    Hyde, T. W.; Alexander, W. M.

    1989-01-01

    In 1967, Lunar Explorer 35 was launched from the earth and placed into a stable orbit around the moon. The data from the dust particle experiment on this spacecraft were essentially continuous over a 5-yr period from the time of insertion in lunar orbit. Analysis of this data has been interpreted to show that micron-sized lunar ejecta leave the moon and traverse through selenocentric and cislunar space and obtain either interplanetary/heliocentric orbits or intercept the earth's magnetosphere and move into geocentric orbits. Extensive studies of the orbital trajectories of lunar particles in this size range have now been conducted that include a calculation of the solar radiation force using the full Mie scattering theory. A significant flux of particles with radii less than 0.1 micron are found to intercept the earth's magnetopause surface. This flux is shown to be strongly dependent upon both the particle's density and its index of refraction.

  11. 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

  12. 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

  13. Recent shallow moonquake and impact-triggered boulder falls on the Moon: New insights from the Schrödinger basin

    Science.gov (United States)

    Senthil Kumar, P.; Sruthi, U.; Krishna, N.; Lakshmi, K. J. P.; Menon, Rajeev; Amitabh; Gopala Krishna, B.; Kring, David A.; Head, James W.; Goswami, J. N.; Kiran Kumar, A. S.

    2016-02-01

    Shallow moonquakes are thought to be of tectonic origin. However, the geologic structures responsible for these moonquakes are unknown. Here we report sites where moonquakes possibly occurred along young lobate scarps in the Schrödinger basin. Our analysis of Lunar Reconnaissance Orbiter and Chandrayaan-1 images revealed four lobate scarps in different parts of the Schrödinger basin. The scarps crosscut small fresh impact craters (bounced on nearby slopes. A cluster of a large number of boulder falls near Scarp 1 indicates that the scarp was seismically active recently. A low runout efficiency of the boulders (~2.5) indicates low to moderate levels of ground shaking, which we interpret to be related to low-magnitude moonquakes in the scarp. Boulder falls are also observed in other parts of the basin, where we mapped >1500 boulders associated with trails and bouncing marks. Their origins are largely controlled by recent impact events. Ejecta rays and secondary crater chains from a 14 km diameter impact crater traversed Schrödinger and triggered significant boulder falls about 17 Ma. Therefore, a combination of recent shallow moonquakes and impact events triggered the boulder falls in the Schrödinger basin.

  14. Atlantic Basin refining profitability

    International Nuclear Information System (INIS)

    Jones, R.J.

    1998-01-01

    A review of the profitability margins of oil refining in the Atlantic Basin was presented. Petroleum refiners face the continuous challenge of balancing supply with demand. It would appear that the profitability margins in the Atlantic Basin will increase significantly in the near future because of shrinking supply surpluses. Refinery capacity utilization has reached higher levels than ever before. The American Petroleum Institute reported that in August 1997, U.S. refineries used 99 per cent of their capacity for several weeks in a row. U.S. gasoline inventories have also declined as the industry has focused on reducing capital costs. This is further evidence that supply and demand are tightly balanced. Some of the reasons for tightening supplies were reviewed. It was predicted that U.S. gasoline demand will continue to grow in the near future. Gasoline demand has not declined as expected because new vehicles are not any more fuel efficient today than they were a decade ago. Although federally-mandated fuel efficiency standards were designed to lower gasoline consumption, they may actually have prevented consumption from falling. Atlantic margins were predicted to continue moving up because of the supply and demand evidence: high capacity utilization rates, low operating inventories, limited capacity addition resulting from lower capital spending, continued U.S. gasoline demand growth, and steady total oil demand growth. 11 figs

  15. Upper Illinois River basin

    Science.gov (United States)

    Friedel, Michael J.

    1998-01-01

    During the past 25 years, industry and government made large financial investments that resulted in better water quality across the Nation; however, many water-quality concerns remain. Following a 1986 pilot project, the U.S. Geological Survey began implementation of the National Water-Quality Assessment (NAWQA) Program in 1991. This program differs from other national water-quality assessment studies in that the NAWQA integrates monitoring of surface- and ground-water quality with the study of aquatic ecosystems. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality.The Upper Illinois River Basin National Water- Quality Assessment (NAWQA) study will increase the scientific understanding of surface- and ground-water quality and the factors that affect water quality in the basin. The study also will provide information needed by water-resource managers to implement effective water-quality management actions and evaluate long-term changes in water quality.

  16. Mars on Earth: Analog basaltic soils and particulates from Lonar Crater, India, include Deccan soil, shocked soil, reworked lithic and glassy ejecta, and both shocked and unshocked baked zones

    Science.gov (United States)

    Wright, S. P.

    2017-12-01

    "There is no perfect analog for Mars on Earth" [first line of Hipkin et al. (2013) Icarus, 261-267]. However, fieldwork and corresponding sample analyses from laboratory instrumentation (to proxy field instruments) has resulted in the finding of unique analog materials that suggest that detailed investigations of Lonar Crater, India would be beneficial to the goals of the Mars Program. These are briefly described below as Analog Processes, Materials, and Fieldwork. Analog Processes: The geologic history of Lonar Crater emulates localities on Mars with 1.) flood basaltic volcanism with interlayer development of 2.) baked zones or "boles" and 3.) soil formation. Of six flows, the lower three are aqueously altered by groundwater to produce a range of 4.) alteration products described below. The impact event 570 ka produced a range of 5.) impactites including shocked baked zones, shocked soils, and altered basalt shocked to a range of shock pressures [Kieffer et al., 1976]. Analog Materials: 65 Ma Deccan basalt contains augite and labradorite. Baked zones are higher in hematite and other iron oxides. Soil consists of calcite and organic matter. Several basalts with secondary alteration are listed here and these mirror alteration on Mars: hematite, chlorite, serpentine, zeolite, and palagonite, with varying combinations of these with primary igneous minerals. All of these materials (#1 through 4 above) are shocked to a range of shocked pressures to produce maskelynite, flowing plagioclase glass, vesiculated plagioclase glass, and complete impact melts. Shocked soils contain schlieren calcite amidst comminuted grains of augite, labradorite, and these glasses. Shocked baked zones unsurprisingly have a petrographic texture similar to hornfels, another product of contact metamorphism. Analog Fieldwork: The ejecta consists of two layers: 8 m of lithic breccia with unshocked and fractured basalts under a 1 m suevite consisting of all ranges of shock pressure described above

  17. Hydrological evolution of Atlantis basin, Sirenum Terrae, Mars. Preliminar analysis of MOC and THEMIS images.

    Science.gov (United States)

    de Pablo, M. A.; Márquez, A.; Centeno, J. D.

    The Atlantis basin is one of the martian highlands areas where there was proposed the existence of an ancient lake during the early geological history of Mars [1] [2] [3] [4]. The existence of some morphological features inside the basin and in the surrounding area, allow to check the existence of liquid water in the past of the planet. On the other hand, other morphological features indicate the existence of snow and liquid groundwater in recent times. The detailed study of the geomorphologic features allows to make an approach to the hydrological evolution of the Atlantis basin. The study of the geomorphology of this region has been carried out by means of the analysis of MOC high resolution images obtained by the Mars Global Surveyor mission and the THEMIS images, in the visible spectrum, sent by Mars Odyssey spacecrafts. The most clearly morphological feature indicative of the existence of water in the surface of Mars in the past are the numerous channels that end into Atlantis basin from the highest terrains. In addiction to these fluvial channels, the existence of mass flow deposits is also indicative of the existence of water in the area. Some of these slumps are in the internal slopes of impact craters, but others cover huge extensions around the chaotic terrains of the studied area. The lobated ejecta deposits observed in the Atlantis basin region are indicative of the existence of groundwater (solid or liquid) [5]. Serrated reliefs and tables in the borders of the basins are indicative of the existence of a water sheet. Beneath this water sheet some deposits was formed which was eroded, due to the gradual desiccation of the basin, forming the tables and serrated reliefs. The existence of different chaotic terrains in the area implies the existence of huge amounts of water under the surface according to the different models of chaotic terrain formation [6] [7]. The existence of groundwater could be decided by the existence of collapses in the near to the

  18. Correlating Distal, Medial and Proximal Ejecta Transport/Emplacement From Oblique Cosmic Impact On North American Continental Ice Sheet At MIS20 ( 786 ka) Via Suborbital Analysis (SA).

    Science.gov (United States)

    Harris, T. H. S.; Davais, M. E.

    2017-12-01

    Several elements of the 786 ka Australasian (AA) tektite imprint bear close scrutinyin order to locate the parent impact site or structure. The unique Carolina bays unit geologic formation is indicated as a large "medial" ejecta blanket from a large cosmic impact during a period containing 786 ka. Coincidence? Kg-scale sub-spherical hollow splash form AA tektites implies prolonged atmospheric blow out-scale momentum current with a core of sub-parallel or divergent flow volume having essentially zero turbulence. This would allow for plasma entrainment and heating of target mass at prolonged low dynamic pressure during outflow, where adiabatic expansion could deliver both semi-solid Muong Nong-type and inviscid melts above the atmosphere for gentle release upon rarefaction in vacuum. Within a large atmospheric blow-out scale momentum current, target mass becomes entrained at the speed of adiabatic outflow. 10+ km/s ejecta entrainment yields inter-hemispheric emplacement from launch per governing suborbital mechanics, without question. Oblique impact into a thick ice sheet explains reduced excavation volume and shearing disruption in the form of hypersonic steam plasma scouring. Adiabatic expansion would be immediately available to accelerate and further heat proto-tektite target mass. With shock no longer the sole transport engine, kg-scale splash forms and tektite speeds above the post-shock vaporization velocity of quartz are explained by expansion of shocked ice, in agreement with the observed imprint. The 6 Carolina bay shapes or "Davias Archetypes" are reproducible using conic perturbation in Suborbital Analysis, conforming to a formative mechanism of suborbital transport and ballistic emplacement: "Suborbital Obstruction Shadowing" needs only 3 parts in 10,000 of VEL variation around a circular EL-AZ-VEL launch cone, before considering re-entry effects. Transport energy of the Carolina bay sand, calculated using the 3.5 to 4 km/s launch VEL required for its

  19. 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

  20. Misrepresenting the Jordan River Basin

    Directory of Open Access Journals (Sweden)

    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.

  1. 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...

  2. Marketing San Juan Basin gas

    International Nuclear Information System (INIS)

    Posner, D.M.

    1988-01-01

    Marketing natural gas produced in the San Juan Basin of New Mexico and Colorado principally involves four gas pipeline companies with significant facilities in the basin. The system capacity, transportation rates, regulatory status, and market access of each of these companies is evaluated. Because of excess gas supplies available to these pipeline companies, producers can expect improved take levels and prices by selling gas directly to end users and utilities as opposed to selling gas to the pipelines for system supply. The complexities of transporting gas today suggest that the services of an independent gas marketing company may be beneficial to smaller producers with gas supplies in the San Juan Basin

  3. Western Canada Sedimentary Basin competitiveness

    International Nuclear Information System (INIS)

    Millar, R.H.G.

    1996-01-01

    Recent dramatic expansion of the natural gas industry in the Western Canada Sedimentary Basin provided ample proof of the potential of this area for further development of natural gas supply. However, the inherent competitive advantages provided by the Western Canada Sedimentary Basin were said to have been offset by low netback prices resulting in poor producer economics when competitiveness is measured by availability of opportunities to find and develop gas supply at costs low enough to ensure attractive returns. Technology was identified as one of the key elements in improving basin competitiveness, but the greatest potential lies in reduced transportation costs and increased access to North American market centres. 8 figs

  4. 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...

  5. The Three-Dimensional Morphology of VY Canis Majoris. II. Polarimetry and the Line-of-Sight Distribution of the Ejecta

    Science.gov (United States)

    Jones, Terry Jay; Humphreys, Roberta M.; Helton, L. Andrew; Gui, Changfeng; Huang, Xiang

    2007-06-01

    We use imaging polarimetry taken with the HST Advanced Camera for Surveys High Resolution Camera to explore the three-dimensional structure of the circumstellar dust distribution around the red supergiant VY Canis Majoris. The polarization vectors of the nebulosity surrounding VY CMa show a strong centrosymmetric pattern in all directions except directly east and range from 10% to 80% in fractional polarization. In regions that are optically thin, and therefore likely to have only single scattering, we use the fractional polarization and photometric color to locate the physical position of the dust along the line of sight. Most of the individual arclike features and clumps seen in the intensity image are also features in the fractional polarization map. These features must be distinct geometric objects. If they were just local density enhancements, the fractional polarization would not change so abruptly at the edge of the feature. The location of these features in the ejecta of VY CMa using polarimetry provides a determination of their three-dimensional geometry independent of, but in close agreement with, the results from our study of their kinematics (Paper I). Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  6. Scientific Objectives of Small Carry-on Impactor (SCI) and Deployable Camera 3 Digital (DCAM3-D): Observation of an Ejecta Curtain and a Crater Formed on the Surface of Ryugu by an Artificial High-Velocity Impact

    Science.gov (United States)

    Arakawa, M.; Wada, K.; Saiki, T.; Kadono, T.; Takagi, Y.; Shirai, K.; Okamoto, C.; Yano, H.; Hayakawa, M.; Nakazawa, S.; Hirata, N.; Kobayashi, M.; Michel, P.; Jutzi, M.; Imamura, H.; Ogawa, K.; Sakatani, N.; Iijima, Y.; Honda, R.; Ishibashi, K.; Hayakawa, H.; Sawada, H.

    2017-07-01

    The Small Carry-on Impactor (SCI) equipped on Hayabusa2 was developed to produce an artificial impact crater on the primitive Near-Earth Asteroid (NEA) 162173 Ryugu (Ryugu) in order to explore the asteroid subsurface material unaffected by space weathering and thermal alteration by solar radiation. An exposed fresh surface by the impactor and/or the ejecta deposit excavated from the crater will be observed by remote sensing instruments, and a subsurface fresh sample of the asteroid will be collected there. The SCI impact experiment will be observed by a Deployable CAMera 3-D (DCAM3-D) at a distance of ˜1 km from the impact point, and the time evolution of the ejecta curtain will be observed by this camera to confirm the impact point on the asteroid surface. As a result of the observation of the ejecta curtain by DCAM3-D and the crater morphology by onboard cameras, the subsurface structure and the physical properties of the constituting materials will be derived from crater scaling laws. Moreover, the SCI experiment on Ryugu gives us a precious opportunity to clarify effects of microgravity on the cratering process and to validate numerical simulations and models of the cratering process.

  7. Allegheny County Basin Outlines Map

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This basins dataset was created to initiate regional watershed approaches with respect to sewer rehabilitation. If viewing this description on the Western...

  8. 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

  9. 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

  10. Geomagnetic field fluctuations during the passage at the Earth’s orbit of the tail of the 15–16 July 2000 ejecta

    Directory of Open Access Journals (Sweden)

    P. Francia

    2002-08-01

    Full Text Available In this work we present the analysis of the geomagnetic field fluctuations observed at different ground stations (approximately along two latitudinal arrays, separated by several hours in local time during the passage at the Earth’s orbit of the tail of the 15–16 July 2000 coronal ejecta. The time interval of interest is characterized by northward interplanetary magnetic field conditions and several changes in the solar wind dynamic pressure. We found at all stations, both in the local morning and in the local evening, simultaneous and highly coherent waves at the same discrete frequencies (~ 1.8 and ~ 3.6 mHz and suggest a possible interpretation in terms of global compressional modes driven by an impulsive variation of the solar wind pressure. Along the array situated in the morning sector, at the highest latitudes, the higher frequency mode seems to couple with the local field line resonance; on the other hand, along the array situated in the evening sector, the characteristics of the observed fluctuations suggest that the highest latitude station could be located at the footprint of open field lines. Our results also show that solar wind pressure variations observed during the recovery phase of the storm do not find correspondence in the geomagnetic field variations, regardless of local time and latitude; conversely, some hours later continuous solar wind pressure variations find a close correspondence in the geomagnetic field variations at all stations.Key words. Magnetospheric physics (solar wind-magnetosphere interaction; MHD waves and instabilities

  11. 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

  12. 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...

  13. 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....

  14. 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 ...

  15. Implementing Integrated River Basin Management in China

    NARCIS (Netherlands)

    Boekhorst, D.G.J. te; Smits, A.J.M.; Yu, X.; Lifeng, L.; Lei, G.; Zhang, C.

    2010-01-01

    This paper examines the role of the World Wildlife Fund for Nature China as policy entrepreneur in China. It illustrates the ways in which the World Wildlife Fund for Nature is active in promoting integrated river basin management in the Yangtze River basin and how the efforts at basin level are

  16. Supplementary information on K-Basin sludges

    International Nuclear Information System (INIS)

    MAKENAS, B.J.

    1999-01-01

    Three previous documents in this series have been published covering the analysis of: K East Basin Floor and Pit Sludge, K East Basin Canister Sludge, and K West Basin Canister Sludge. Since their publication, additional data have been acquired and analyses performed. It is the purpose of this volume to summarize the additional insights gained in the interim time period

  17. The Mackenzie Basin impacts study

    International Nuclear Information System (INIS)

    Cohen, S.J.

    1993-01-01

    In 1989, a commitment was made to begin development of a framework for an integrated regional impact assessment of global warming scenarios in the Mackenzie Basin, the most populated region of Canada's north. The project, called Mackenzie Basin Impact Study (MBIS), is led by a multidisciplinary working group from government and non-governmental organizations with interests in the Basin. Objectives of MBIS include defining the direction and magnitude of regional-scale impacts of global warming scenarios on the physical, biological, and human systems of the Basin. MBIS will also identify regional sensitivities to climate, inter-system linkages, uncertainties, policy implications, and research needs. MBIS research activities as of March 1992 are outlined and policy concerns related to global warming are listed. Two new methodologies are being developed by MBIS to address particular economic and policy concerns: a socio-economic resource accounting framework and an integrated land assessment framework. Throughout MBIS, opportunities will be presented for western science and traditional native knowledge to be integrated

  18. Great Basin paleoenvironmental studies project

    International Nuclear Information System (INIS)

    1993-01-01

    Project goals, project tasks, progress on tasks, and problems encountered are described and discussed for each of the studies that make up the Great Basin Paleoenvironmental Studies Project for Yucca Mountain. These studies are: Paleobotany, Paleofauna, Geomorphology, and Transportation. Budget summaries are also given for each of the studies and for the overall project

  19. The Amazon Basin in transition

    Science.gov (United States)

    Eric A. Davidson; Alessandro C. de Araujo; Paulo Artaxo; Jennifer K. Balch; I. Foster Brown; Mercedes M.C. Bustamente; Michael T. Coe; Ruth S. DeFriess; Michael Keller; Marcos Longo; J. William Munger; Wilfrid Schroeder; Britaldo Soares-Filho; Carlos M. Souza, Jr.; Steven C. Wofsy

    2012-01-01

    Agricultural expansion and climate variability have become important agents of disturbance in the Amazon basin. Recent studies have demonstrated considerable resilience of Amazonian forests to moderate annual drought, but they also show that interactions between deforestation, fire and drought potentially lead to losses of carbon storage and changes in regional...

  20. 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

  1. Great Basin wildlife disease concerns

    Science.gov (United States)

    Russ Mason

    2008-01-01

    In the Great Basin, wildlife diseases have always represented a significant challenge to wildlife managers, agricultural production, and human health and safety. One of the first priorities of the U.S. Department of Agriculture, Division of Fish and Wildlife Services was Congressionally directed action to eradicate vectors for zoonotic disease, particularly rabies, in...

  2. 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

  3. Ancient Bombardment of the Inner Solar System: Reinvestigation of the "Fingerprints" of Different Impactor Populations on the Lunar Surface

    Science.gov (United States)

    Orgel, Csilla; Michael, Gregory; Fassett, Caleb I.; van der Bogert, Carolyn H.; Riedel, Christian; Kneissl, Thomas; Hiesinger, Harald

    2018-03-01

    The lunar cratering record provides valuable information about the late accretion history of the inner solar system. However, our understanding of the origin, rate, and timing of the impacting projectiles is far from complete. To learn more about these projectiles, we can examine crater size-frequency distributions (CSFDs) on the Moon. Here we reinvestigate the crater populations of 30 lunar basins (≥ 300 km) using the buffered nonsparseness correction technique, which takes crater obliteration into account, thus providing more accurate measurements for the frequencies of smaller crater sizes. Moreover, we revisit the stratigraphic relationships of basins based on N(20) crater frequencies, absolute model ages, and observation data. The buffered nonsparseness correction-corrected CSFDs of individual basins, particularly at smaller crater diameters are shifted upward. Contrary to previous studies, the shapes of the summed CSFDs of Pre-Nectarian (excluding South Pole-Aitken Basin), Nectarian (including Nectaris), and Imbrian (including Imbrium) basins show no statistically significant differences and thus provide no evidence for a change of impactor population.

  4. THE ADVANCED CHEMISTRY BASINS PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    William Goddard; Peter Meulbroek; Yongchun Tang; Lawrence Cathles III

    2004-04-05

    In the next decades, oil exploration by majors and independents will increasingly be in remote, inaccessible areas, or in areas where there has been extensive shallow exploration but deeper exploration potential may remain; areas where the collection of data is expensive, difficult, or even impossible, and where the most efficient use of existing data can drive the economics of the target. The ability to read hydrocarbon chemistry in terms of subsurface migration processes by relating it to the evolution of the basin and fluid migration is perhaps the single technological capability that could most improve our ability to explore effectively because it would allow us to use a vast store of existing or easily collected chemical data to determine the major migration pathways in a basin and to determine if there is deep exploration potential. To this end a the DOE funded a joint effort between California Institute of Technology, Cornell University, and GeoGroup Inc. to assemble a representative set of maturity and maturation kinetic models and develop an advanced basin model able to predict the chemistry of hydrocarbons in a basin from this input data. The four year project is now completed and has produced set of public domain maturity indicator and maturation kinetic data set, an oil chemistry and flash calculation tool operable under Excel, and a user friendly, graphically intuitive basin model that uses this data and flash tool, operates on a PC, and simulates hydrocarbon generation and migration and the chemical changes that can occur during migration (such as phase separation and gas washing). The DOE Advanced Chemistry Basin Model includes a number of new methods that represent advances over current technology. The model is built around the concept of handling arbitrarily detailed chemical composition of fluids in a robust finite-element 2-D grid. There are three themes on which the model focuses: chemical kinetic and equilibrium reaction parameters, chemical

  5. K West Basin canister survey

    International Nuclear Information System (INIS)

    Pitner, A.L.

    1998-01-01

    A survey was conducted of the K West Basin to determine the distribution of canister types that contain the irradiated N Reactor fuel. An underwater camera was used to conduct the survey during June 1998, and the results were recorded on videotape. A full row-by-row survey of the entire basin was performed, with the distinction between aluminum and stainless steel Mark 1 canisters made by the presence or absence of steel rings on the canister trunions (aluminum canisters have the steel rings). The results of the survey are presented in tables and figures. Grid maps of the three bays show the canister lid ID number and the canister type in each location that contained fuel. The following abbreviations are used in the grid maps for canister type designation: IA = Mark 1 aluminum, IS = Mark 1 stainless steel, and 2 = Mark 2 stainless steel. An overall summary of the canister distribution survey is presented in Table 1. The total number of canisters found to contain fuel was 3842, with 20% being Mark 1 Al, 25% being Mark 1 SS, and 55% being Mark 2 SS. The aluminum canisters were predominantly located in the East and West bays of the basin

  6. Uranium geochemistry of Orca Basin

    International Nuclear Information System (INIS)

    Weber, F.F. Jr.; Sackett, W.M.

    1981-01-01

    Orca Basin, an anoxic, brine-filled depression at a depth of 2200 m in the Northwestern Gulf of Mexico continental slope, has been studied with respect to its uranium geochemistry. Uranium concentration profiles for four cores from within the basin were determined by delayed-neutron counting. Uranium concentrations ranged from 2.1 to 4.1 ppm on a salt-free and carbonate-corrected basis. The highest uranium concentrations were associated with the lowest percentage and delta 13 C organic carbon values. For comparison, cores from the brine-filled Suakin and Atlantis II Deeps, both in the Red Sea, were also analyzed. Uranium concentrations ranged from 1.2 to 2.6 ppm in the Suakin Deep and from 8.0 to 11.0 ppm in the Atlantis II Deep. No significant correlation was found between uranium concentrations and organic carbon concentrations and delta 13 C values for these cores. Although anoxic conditions are necessary for significant uranium uptake by non-carbonate marine sediments, other factors such as dilution by rapidly depositing materials and uranium supply via mixing and diffusion across density gradients may be as important in determining uranium concentrations in hypersaline basin sediments. (author)

  7. Lunar Meteorites Sayh Al Uhaymir 449 and Dhofar 925, 960, and 961: Windows into South Pole

    Science.gov (United States)

    Ziegler, Ryan A.; Jolliff, B. L.; Korotev, R. L.

    2013-01-01

    In 2003, three lunar meteorites were collected in close proximity to each other in the Dhofar region of Oman: Dhofar 925 (49 g), Dhofar 960 (35 g), and Dhofar 961 (22 g). In 2006, lunar meteorite Sayh al Uhaymir (SaU) 449 (16.5 g) was found about 100 km to the NE. Despite significant differences in the bulk composition of Dhofar 961 relative to Dhofar 925/960 and SaU 449 (which are identical to each other), these four meteorites are postulated to be paired based on their find locations, bulk composition, and detailed petrographic analysis. Hereafter, they will collectively be referred to as the Dhofar 961 clan. Comparison of meteorite and component bulk compositions to Lunar Prospector 5-degree gamma-ray data suggest the most likely provenance of this meteorite group is within the South Pole-Aitken Basin. As the oldest, largest, and deepest recognizable basin on the Moon, the composition of the material within the SPA basin is of particular importance to lunar science. Here we review and expand upon the geochemistry and petrography of the Dhofar 961 clan and assess the likelihood that these meteorites come from within the SPA basin based on their bulk compositions and the compositions and characteristics of the major lithologic components found within the breccia.

  8. The geologic history of Margaritifer basin, Mars

    Science.gov (United States)

    Salvatore, M. R.; Kraft, M. D.; Edwards, Christopher; Christensen, P.R.

    2016-01-01

    In this study, we investigate the fluvial, sedimentary, and volcanic history of Margaritifer basin and the Uzboi-Ladon-Morava (ULM) outflow channel system. This network of valleys and basins spans more than 8000 km in length, linking the fluvially dissected southern highlands and Argyre Basin with the northern lowlands via Ares Vallis. Compositionally, thermophysically, and morphologically distinct geologic units are identified and are used to place critical relative stratigraphic constraints on the timing of geologic processes in Margaritifer basin. Our analyses show that fluvial activity was separated in time by significant episodes of geologic activity, including the widespread volcanic resurfacing of Margaritifer basin and the formation of chaos terrain. The most recent fluvial activity within Margaritifer basin appears to terminate at a region of chaos terrain, suggesting possible communication between surface and subsurface water reservoirs. We conclude with a discussion of the implications of these observations on our current knowledge of Martian hydrologic evolution in this important region.

  9. The Donets Basin (Ukraine/Russia): coalification and thermal history.

    NARCIS (Netherlands)

    Sachsenhofer, R.F.; Privalov, V.A.; Zhykalyak, M.V.; Bueker, C.; Panova, E.A.; Rainer, T.; Shymanovskyy, V.A.; Stephenson, R.A.

    2002-01-01

    The Donets Basin (Donbas) is one of the major late Paleozoic coal basins in the world. The Donbas Foldbelt is an inverted part of the Donets Basin characterized by WNW-ESE-trending folds and faults. The age of basin inversion is under discussion. Large parts of the Donets Basin host anthracite and

  10. Reserves in western basins: Part 1, Greater Green River basin

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.

  11. SMART-1 Results and Lessons for Future Exploration

    Science.gov (United States)

    Foing, B. H.

    2009-04-01

    Jan 2005 solar flare, permitting the first detection of Calcium from lunar orbit [9]. Bulk crustal composition has bearing on theories of origin and evolution of the Moon. D-CIXS produced the first global measurements of the lunar surface in X-ray fluorescence (XRF), elemental abundances of Mg, Al and Si (and Fe when solar activity permitted) across the whole Moon. The South Pole-Aitken Basin (SPA) and large lunar impact basins have been also measured with D-CIXS. D-CIXS has been improved for the C1XS instrument adapted to ISRO Chandrayaan-1. SIR (Smart-1 Infra-Red Spectrometer). SIR has been operating in the 0.9-2.6 μm wavelength range and carrying out mineralogical survey of the lunar crust. SIR had high enough spectral resolution to separate the pyroxene and olivine signatures in lunar soils. SIR data with spatial resolution as good as 400 m permitted to distinguish units on central peaks, walls, rims and ejecta blankets of large impact craters, allowing for stratigraphic studies of the lunar crust. SIR has been improved for the Chandrayaan-1 SIR2 instrument. SMART-1 overall planetary science: SMART-1 science investigations included studies of the chemical composition of the Moon, of geophysical processes (volcanism, tectonics, cratering, erosion, deposition of ices and volatiles) for comparative planetology, and high resolution studies in preparation for future steps of lunar exploration. The mission addressed several topics such as the accretional processes that led to the formation of rocky planets, and the origin and evolution of the Earth-Moon system [8]. SMART-1 operations and coordination: The Experiments have been run according to illumination and altitude conditions during the nominal science phase of 6-months and 1 yr extension, in elliptical Moon orbit. The planning and co-ordination of the Technology and science experiments operations was carried out at ESA/ESTEC (SMART-1 STOC). The data archiving is based on the PDS (Planetary Data System) Standard

  12. 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.

  13. New TNX Seepage Basin: Environmental information document

    International Nuclear Information System (INIS)

    Dunaway, J.K.W.; Johnson, W.F.; Kingley, L.E.; Simmons, R.V.; Bledsoe, H.W.

    1986-12-01

    The New TNX Seepage Basin has been in operation at the Savannah River Plant (SRP) since 1980 and is located in the southeastern section of the TNX facility. The basin receives waste from pilot scale tests conducted at TNX in support of the Defense Waste Processing Facility (DWPF) and the plant Separations area. The basin is scheduled for closure after the TNX Effluent Treatment Plant (ETP) begins operation. The basin will be closed pursuant to all applicable state and federal regulations. A statistical analysis of monitoring data indicates elevated levels of sodium and zinc in the groundwater at this site. Closure options considered for the New TNX Seepage Basin include waste removal and closure, no waste removal and closure, and no action. The two predominant pathways for human exposure to chemical contaminants are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options for the New TNX Seepage Basin. Cost estimates for each closure option at the basin have also been prepared. An evaluation of the environmental impacts from the New TNX Seepage Basin indicate that the relative risks to human health and ecosystems for the postulated closure options are low. The transport of six chemical and one radionuclide constituents through the environmental pathways from the basin were modeled. The maximum chemical carcinogenic risk and the noncarcinogenic risk for the groundwater pathways were from exposure to trichloromethane and nitrate

  14. 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.

  15. 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

  16. Suceava Anthropic Torrential Basin - Prolegomena

    Directory of Open Access Journals (Sweden)

    Andrei-Emil BRICIU

    2010-05-01

    Full Text Available One problem discussed by urban hydrology today is the draining influence of the modern cities over the natural drainage systems. The increasing urban areas and of their imperviousness all over theworld is linked to floods shape modifications and unpredicted systemic implications.  Generally, the draining influence of a city over its environment begins when it has a surface great enough to create an anthropic-generated runoff during a rain with enoughprecipitations to provoke waters accumulation into street torrents. The size, imperviousness, precipitations, drainage system and water consumption of the Suceava city are analysed in order to estimate the discharge of the city into Suceava river at various rainfalls. The article is structured as follows:1. Argumentation on the class separation between natural and anthropic torrential basins.2. Placing Suceava city as one of the torrential anthropic basins in Romania using basic arguments.3. Extending one of the argument, the importance of the rainfalls, in more detailed discussions (rainfall characteristics mainly, but also its cumulative effect with the floods on the Suceava river and the consumption of water in the city, with two scenarios. 4. The city is analysed as being integrated into a metropolitan area which can exacerbate the influence of the main city over the surrounding natural drainage basins nearby that area.5. Conclusions, where measures are proposed in order to diminish the potential negative effects on environment and human society.This article is only an introduction to a more detailed analysis which will be complete with further field data.

  17. Salt disposal: Paradox Basin, Utah

    International Nuclear Information System (INIS)

    1983-04-01

    This report presents the findings of a study conducted for the National Waste Terminal Storage (NWTS) Program. Permanent disposal options are examined for salt resulting from the excavation of a waste repository in the bedded salt deposits of the Paradox Basin of southeastern Utah. The study is based on a repository salt backfill compaction of 60% of the original density which leaves a total of 8 million tons of 95% pure salt to be disposed of over a 30-year period. The feasibility, impacts, and mitigation methods are examined for five options: commercial disposal, permanent onsite surface disposal, permanent offsite disposal, deepwell injection, and ocean and Great Salt Lake disposal. The study concludes the following: Commercial marketing of all repository salt would require a subsidy for transportation to major salt markets. Permanent onsite surface storage is both economically and technically feasible. Permanent offsite disposal is technically feasible but would incur additional transportation costs. Selection of an offsite location would provide a means of mitigating impacts associated with surface storage at the repository site. Deepwell injection is an attractive disposal method; however, the large water requirement, high cost of development, and poor performance of similar operating brine disposal wells eliminates this option from consideration as the primary means of disposal for the Paradox Basin. Ocean disposal is expensive because of high transportation cost. Also, regulatory approval is unlikely. Ocean disposal should be eliminated from further consideration in the Paradox Basin. Great Salt Lake disposal appears to be technically feasible. Great Salt Lake disposal would require state approval and would incur substantial costs for salt transportation. Permanent onsite disposal is the least expensive method for disposal of all repository salt

  18. Delaware Basin Monitoring Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2001-09-28

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. EPA requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard and must consider inadvertent drilling into the repository at some future time.

  19. Delaware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    2001-01-01

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. EPA requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard and must consider inadvertent drilling into the repository at some future time.

  20. K Basins Field Verification Program

    International Nuclear Information System (INIS)

    Booth, H.W.

    1994-01-01

    The Field Verification Program establishes a uniform and systematic process to ensure that technical information depicted on selected engineering drawings accurately reflects the actual existing physical configuration. This document defines the Field Verification Program necessary to perform the field walkdown and inspection process that identifies the physical configuration of the systems required to support the mission objectives of K Basins. This program is intended to provide an accurate accounting of the actual field configuration by documenting the as-found information on a controlled drawing

  1. Identification of basin characteristics influencing spatial variation of river flows

    NARCIS (Netherlands)

    Mazvimavi, D.; Burgers, S.L.G.E.; Stein, A.

    2006-01-01

    The selection of basin characteristics that explain spatial variation of river flows is important for hydrological regionalization as this enables estimation of flow statistics of ungauged basins. A direct gradient analysis method, redundancy analysis, is used to identify basin characteristics,

  2. Regionalization of the Upper Tana Basin of Kenya Using Stream ...

    African Journals Online (AJOL)

    Regionalization of the Upper Tana Basin of Kenya Using Stream Flow Records. ... river gauge stations in the basin using the empirical orthogonal function analysis ... the study basin to be grouped into four homogenous hydrological zones that ...

  3. Basin Assessment Spatial Planning Platform

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-26

    The tool is intended to facilitate hydropower development and water resource planning by improving synthesis and interpretation of disparate spatial datasets that are considered in development actions (e.g., hydrological characteristics, environmentally and culturally sensitive areas, existing or proposed water power resources, climate-informed forecasts). The tool enables this capability by providing a unique framework for assimilating, relating, summarizing, and visualizing disparate spatial data through the use of spatial aggregation techniques, relational geodatabase platforms, and an interactive web-based Geographic Information Systems (GIS). Data are aggregated and related based on shared intersections with a common spatial unit; in this case, industry-standard hydrologic drainage areas for the U.S. (National Hydrography Dataset) are used as the spatial unit to associate planning data. This process is performed using all available scalar delineations of drainage areas (i.e., region, sub-region, basin, sub-basin, watershed, sub-watershed, catchment) to create spatially hierarchical relationships among planning data and drainages. These entity-relationships are stored in a relational geodatabase that provides back-end structure to the web GIS and its widgets. The full technology stack was built using all open-source software in modern programming languages. Interactive widgets that function within the viewport are also compatible with all modern browsers.

  4. sedimentology, depositional environments and basin evolution

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: The Inter-Trappean coal and oil shale-bearing sedimentation in the Delbi-Moye Basin took place in tectonically controlled grabens and half-grabens formed by extensional fault systems and accompanied by passive subsidence. The sedimentation history of the basin is related to the tectonic events that affected ...

  5. sedimentology, depositional environments and basin evolution

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: The Inter-Trappean coal and oil shale-bearing sedimentation in the Delbi-Moye Basin ... accompanied by passive subsidence. ... margins, whereas the concentration of fine-grained clastic sediments and ..... concentrated at the marginal areas of the basin. .... faults favoured the accumulation of alluvial fan.

  6. Proterozoic intracontinental basin: The Vindhyan example

    Indian Academy of Sciences (India)

    basins display marked similarities in their lithology, depositional setting and stratigraphic architecture. (Naqvi and Rogers 1987). This note sum- marises the stratigraphy, stratal architecture, sed- imentology and geochronology of the Vindhyan. Supergroup occurring in the Son valley region. (figure 1). 2. The Vindhyan basin.

  7. Attractors and basins of dynamical systems

    Directory of Open Access Journals (Sweden)

    Attila Dénes

    2011-03-01

    Full Text Available There are several programs for studying dynamical systems, but none of them is very useful for investigating basins and attractors of higher dimensional systems. Our goal in this paper is to show a new algorithm for finding even chaotic attractors and their basins for these systems. We present an implementation and examples for the use of this program.

  8. K-Basin isolation barrier seal

    International Nuclear Information System (INIS)

    Ruff, E.S.

    1994-10-01

    This report documents various aspects of the design, analysis, procurement, and fabrication of the hydraulic seal on the isolation barriers to be installed in the 100-K Area spent nuclear fuel basin. The isolation barrier is used to keep water in the basin in the event of an earthquake

  9. 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

  10. 105-KE basin pilot run relocation

    International Nuclear Information System (INIS)

    Crystal, J.B.

    1994-01-01

    The purpose of this document is to present the bases for selecting the exact in-facility location for installation of process equipment to support pilot testing activities in the 105-KE Basin at the United States Department of Energy Hanford Site, in southeastern Washington State. The 105-KE Basin was constructed during the early 1950s, as an integralcomponent of the 105-K East reactor building. Similar basins were provided in all Hanford weapons production reactor buildings to receive fuel elements discharged from the reactors and stage them for rail transport to 200 Area fuel reprocessing plants. The 105-KE reactor began operation in 1955. It was shut down in 1971. However, the 105-KE Basin was reactivated several years later to store spent fuel from the N-Reactor basin and permit its continued operation during outages at the Plutonium Uranium Extraction (PUREX) plant in the 200E Area

  11. Implementing Integrated River Basin Management in China

    Directory of Open Access Journals (Sweden)

    Dorri G. J. te Boekhorst

    2010-06-01

    Full Text Available This paper examines the role of the World Wildlife Fund for Nature China as policy entrepreneur in China. It illustrates the ways in which the World Wildlife Fund for Nature is active in promoting integrated river basin management in the Yangtze River basin and how the efforts at basin level are matched with the advice of the China Council for International Cooperation on Environment and Development task force on integrated river basin management to the national government of China. This article demonstrates that the World Wildlife Fund for Nature uses various strategies of different types to support a transition process towards integrated river basin management. Successful deployment of these strategies for change in environmental policy requires special skills, actions, and attitudes on the part of the policy entrepreneur, especially in China, where the government has a dominant role regarding water management and the position of policy entrepeneurs is delicate.

  12. An underground view of the Albuquerque Basin

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, J.W.; Haase, C.S.; Lozinsky, R.P. [New Mexico Bureau of Mines and Mineral Resources, Socorro, NM (United States)

    1995-12-31

    Development of valid hydrogeologic models of New Mexico`s ``critical groundwater basins`` has been a long-term objective of the New Mexico Bureau of Mines and Mineral Resources (NMBMMR), a division of New Mexico Tech. The best possible information on basin hydrogeology is needed not only for incorporation in numerical models of groundwater-flow systems, which are necessary for proper management of limited water resources, but also for addressing public concerns relating to a wide range of important environmental issues. In the latter case, a hydrogeologist must be prepared to provide appropriate explanations of why groundwater systems behave physically and chemically as they do in both natural and man-disturbed situations. The paper describes the regional geologic setting, the geologic setting of the Albuquerque Basin, basin- and valley-fill stratigraphy, and the hydrogeologic model of the Albuquerque Basin. 77 refs., 6 figs., 1 tab.

  13. Klamath River Basin water-quality data

    Science.gov (United States)

    Smith, Cassandra D.; Rounds, Stewart A.; Orzol, Leonard L.; Sobieszczyk, Steven

    2018-05-29

    The Klamath River Basin stretches from the mountains and inland basins of south-central Oregon and northern California to the Pacific Ocean, spanning multiple climatic regions and encompassing a variety of ecosystems. Water quantity and water quality are important topics in the basin, because water is a critical resource for farming and municipal use, power generation, and for the support of wildlife, aquatic ecosystems, and endangered species. Upper Klamath Lake is the largest freshwater lake in Oregon (112 square miles) and is known for its seasonal algal blooms. The Klamath River has dams for hydropower and the upper basin requires irrigation water to support agriculture and grazing. Multiple species of endangered fish inhabit the rivers and lakes, and the marshes are key stops on the Pacific flyway for migrating birds. For these and other reasons, the water resources in this basin have been studied and monitored to support their management distribution.

  14. Delaware Basin Monitoring Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2002-09-21

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  15. Delaware Basin Monitoring Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2003-09-30

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  16. Delaware Basin Monitoring Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2005-09-30

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  17. Delaware Basin Monitoring Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2004-09-30

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  18. Deleware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    2000-01-01

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  19. Delaware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    2005-01-01

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  20. Delaware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    2002-01-01

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  1. Delaware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    2004-01-01

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  2. Delaware Basin Monitoring Annual Report

    International Nuclear Information System (INIS)

    2003-01-01

    The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

  3. East Asia basin Analysis Project

    International Nuclear Information System (INIS)

    Terman, M.J.

    1986-01-01

    The United Nations-related Committee for Coordination of Joint Prospecting for Mineral Resources in Asian Offshore Areas (CCOP), in cooperation with the International Union of Geological Sciences and Circum-Pacific Council, is implementing the East Asia Basin Analysis Project. National and regional organizations, principally members of the ASEAN Council of Petroleum, are compiling maps at a scale of 1:2 million and stratigraphic cross sections of basins, with particular initial emphasis on defining and assessing oil and gas plays and with later analytical focus on other sedimentary minerals (e.g., coal, phosphate, evaporites, and uranium). Completion is anticipated in 1988. Two major elements of the project are being contributed from other agencies. (1) Base maps. - The US Geological Survey (USGS) has partly compiled eight sheets covering east Asia that show bathymetry, shorelines, and drainage systems. One sheet also presents topography and selected cultural features. All sheets are scheduled to be completed in 1987. (2) Geotectonic maps. - The Working Group on Studies of East Asian Tectonics and Resources (SEATAR) is now completing 10 transect studies with crustal profiles and strip maps at a scale of 1:1 million. One map for each transect shows a plate tectonic interpretation. Transect coordinators or others will be encouraged to extrapolate between the strips and complete the geotectonic interpretation (on USGS bases) in 1987. The IGCP Project 220 is also compiling on (USGS bases) the tin and tungsten granites of east Asia, emphasizing geochemical data needed to identify predictive models. Other mapping will probably follow mineral-deposit modeling workshops on ophiolotic chromite and regional symposia on oceanic massive sulfide and subvolcanic gold and base metals. Completion may be possible by 1989

  4. Submarine landslides in Arctic sedimentation: Canada Basin

    Science.gov (United States)

    Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Lebedova-Ivanova, N; Chapman, C.

    2016-01-01

    Canada Basin of the Arctic Ocean is the least studied ocean basin in the World. Marine seismic field programs were conducted over the past 6 years using Canadian and American icebreakers. These expeditions acquired more than 14,000 line-km of multibeam bathymetric and multi-channel seismic reflection data over abyssal plain, continental rise and slope regions of Canada Basin; areas where little or no seismic reflection data existed previously. Canada Basin is a turbidite-filled basin with flat-lying reflections correlateable over 100s of km. For the upper half of the sedimentary succession, evidence of sedimentary processes other than turbidity current deposition is rare. The Canadian Archipelago and Beaufort Sea margins host stacked mass transport deposits from which many of these turbidites appear to derive. The stratigraphic succession of the MacKenzie River fan is dominated by mass transport deposits; one such complex is in excess of 132,000 km2 in area and underlies much of the southern abyssal plain. The modern seafloor is also scarred with escarpments and mass failure deposits; evidence that submarine landsliding is an ongoing process. In its latest phase of development, Canada Basin is geomorphologically confined with stable oceanographic structure, resulting in restricted depositional/reworking processes. The sedimentary record, therefore, underscores the significance of mass-transport processes in providing sediments to oceanic abyssal plains as few other basins are able to do.

  5. 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.

  6. Western Gas Sands Project. Quarterly Basin Activities Report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C H

    1979-01-31

    This report is a summation of 3 months' drilling and testing activities in the four primary WGSP study areas: Greater Green River Basin, Northern Great Plains Province, Piceance Basin, and Uinta Basin. The monitoring of basin activities is part of resource assessment. (DLC)

  7. Estimating Stream Discharge of Aboine River Basin of Southeast ...

    African Journals Online (AJOL)

    ADOWIE PERE

    of inter-basin parameters showed that the Aboine drainage basin is basically a flat surface. This ... on the fluvial system and also for predicting the basin output variables. Surface .... outflows of rainwater from the basin as has been done by ...

  8. A proposal for an administrative set up of river basin management in the Sittaung River Basin

    OpenAIRE

    Tun, Zaw Lwin; Ni, Bo; Tun, Sein; Nesheim, Ingrid

    2016-01-01

    The purpose of this report is to present a proposal for how an administrative approach based on River Basin Management can be implemented in Myanmar. The Sittaung River Basin has been used as an example area to investigate how the basin can be administered according to the IWRM principles of cooperation between the different sectors and the administrative units, including stakeholder involvement. Ministry of Natural Resource and Environmental Conservation, Myanmar Norwegian Ministry of For...

  9. 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.

  10. Fishes of the White River basin, Indiana

    Science.gov (United States)

    Crawford, Charles G.; Lydy, Michael J.; Frey, Jeffrey W.

    1996-01-01

    Since 1875, researchers have reported 158 species of fish belonging to 25 families in the White River Basin. Of these species, 6 have not been reported since 1900 and 10 have not been reported since 1943. Since the 1820's, fish communities in the White River Basin have been affected by the alteration of stream habitat, overfishing, the introduction of non-native species, agriculture, and urbanization. Erosion resulting from conversion of forest land to cropland in the 1800's led to siltation of streambeds and resulted in the loss of some silt-sensitive species. In the early 1900's, the water quality of the White River was seriously degraded for 100 miles by untreated sewage from the City of Indianapolis. During the last 25 years, water quality in the basin has improved because of efforts to control water pollution. Fish communities in the basin have responded favorably to the improved water quality.

  11. 183-H Basin sludge treatability test report

    International Nuclear Information System (INIS)

    Biyani, R.K.

    1995-01-01

    This document presents the results from the treatability testing of a 1-kg sample of 183-H Basin sludge. Compressive strength measurements, Toxic Characteristic Leach Procedure, and a modified ANSI 16.1 leach test were conducted

  12. K-Basins S/RIDS

    Energy Technology Data Exchange (ETDEWEB)

    Watson, D.J.

    1997-08-01

    The Standards/Requirements Identification Document (S/RID) is a list of the Environmental, Safety, and Health (ES{ampersand}H) and Safeguards and Security (SAS) standards/requirements applicable to the K Basins facility.

  13. K-Basins S/RIDS

    Energy Technology Data Exchange (ETDEWEB)

    Watson, D.J.

    1995-09-22

    The Standards/Requirements Identification Document(S/RID) is a list of the Environmental, Safety, and Health (ES&H) and Safeguards and Security (SAS) standards/requirements applicable to the K Basins facility

  14. K-Basins S/RIDS

    International Nuclear Information System (INIS)

    Watson, D.J.

    1997-01-01

    The Standards/Requirements Identification Document (S/RID) is a list of the Environmental, Safety, and Health (ES(ampersand)H) and Safeguards and Security (SAS) standards/requirements applicable to the K Basins facility

  15. KE Basin water dispositioning engineering study

    International Nuclear Information System (INIS)

    Hunacek, G.S.; Gahir, S.S.

    1994-01-01

    This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation

  16. River Basin Standards Interoperability Pilot

    Science.gov (United States)

    Pesquer, Lluís; Masó, Joan; Stasch, Christoph

    2016-04-01

    There is a lot of water information and tools in Europe to be applied in the river basin management but fragmentation and a lack of coordination between countries still exists. The European Commission and the member states have financed several research and innovation projects in support of the Water Framework Directive. Only a few of them are using the recently emerging hydrological standards, such as the OGC WaterML 2.0. WaterInnEU is a Horizon 2020 project focused on creating a marketplace to enhance the exploitation of EU funded ICT models, tools, protocols and policy briefs related to water and to establish suitable conditions for new market opportunities based on these offerings. One of WaterInnEU's main goals is to assess the level of standardization and interoperability of these outcomes as a mechanism to integrate ICT-based tools, incorporate open data platforms and generate a palette of interchangeable components that are able to use the water data emerging from the recently proposed open data sharing processes and data models stimulated by initiatives such as the INSPIRE directive. As part of the standardization and interoperability activities in the project, the authors are designing an experiment (RIBASE, the present work) to demonstrate how current ICT-based tools and water data can work in combination with geospatial web services in the Scheldt river basin. The main structure of this experiment, that is the core of the present work, is composed by the following steps: - Extraction of information from river gauges data in OGC WaterML 2.0 format using SOS services (preferably compliant to the OGC SOS 2.0 Hydrology Profile Best Practice). - Model floods using a WPS 2.0, WaterML 2.0 data and weather forecast models as input. - Evaluation of the applicability of Sensor Notification Services in water emergencies. - Open distribution of the input and output data as OGC web services WaterML, / WCS / WFS and with visualization utilities: WMS. The architecture

  17. Petrologic Characteristics of the Lunar Surface.

    Science.gov (United States)

    Wang, Xianmin; Pedrycz, Witold

    2015-11-27

    Petrologic analysis of the lunar surface is critical for determining lunar formation and evolution. Here, we report the first global petrologic map that includes the five most important lunar lithological units: the Ferroan Anorthositic (FAN) Unit, the Magnesian Suite (MS) Unit, the Alkali Suite (AS) Unit, the KREEP Basalt (KB) Unit and the Mare Basalt (MB) Unit. Based on the petrologic map and focusing on four long-debated and important issues related to lunar formation and evolution, we draw the following conclusions from the new insights into the global distribution of the five petrologic units: (1) there may be no petrogenetic relationship between MS rocks and KB; (2) there may be no petrogenetic link between MS and AS rocks; (3) the exposure of the KREEP component on the lunar surface is likely not a result of MB volcanism but is instead mainly associated with the combined action of plutonic intrusion, KREEP volcanism and celestial collision; (4) the impact size of the South Pole-Aitken basin is constrained, i.e., the basin has been excavated through the whole crust to exhume a vast majority of lower-crustal material and a very limited mantle components to the lunar surface.

  18. Susquehanna River Basin Flood Control Review Study

    Science.gov (United States)

    1980-08-01

    and made recommendations for an intergrated water plan for the Basin and included a specific Early Action Plan. Concerning flood damage reduction, the...transportation and by agriculture as a source of income and occupation. The river served as a source of transportation for trade and commerce and also as a... trade patterns, and labor market areas. The Susquehanna River Basin is largely comprised of BEA economic areas 011, 012, 013, and 016. Figure II shows the

  19. Geo-economy of the Caspian basin

    International Nuclear Information System (INIS)

    Raballand, G.

    2003-05-01

    The Caspian area is essential for the development of the central Asia countries and Caucasus. Excepted the Iran and the Russia, these areas economy is poor. The hydrocarbons exploitation should reinforce the economic weight of these States. The author analyzes the Caspian area economies and shows that the basin economies are confronted with three handicaps, and that even with different economic ways, the soviet economic system is still present in the basin. (A.L.B.)

  20. Are calanco landforms similar to river basins?

    Science.gov (United States)

    Caraballo-Arias, N A; Ferro, V

    2017-12-15

    In the past badlands have been often considered as ideal field laboratories for studying landscape evolution because of their geometrical similarity to larger fluvial systems. For a given hydrological process, no scientific proof exists that badlands can be considered a model of river basin prototypes. In this paper the measurements carried out on 45 Sicilian calanchi, a type of badlands that appears as a small-scale hydrographic unit, are used to establish their morphological similarity with river systems whose data are available in the literature. At first the geomorphological similarity is studied by identifying the dimensionless groups, which can assume the same value or a scaled one in a fixed ratio, representing drainage basin shape, stream network and relief properties. Then, for each property, the dimensionless groups are calculated for the investigated calanchi and the river basins and their corresponding scale ratio is evaluated. The applicability of Hack's, Horton's and Melton's laws for establishing similarity criteria is also tested. The developed analysis allows to conclude that a quantitative morphological similarity between calanco landforms and river basins can be established using commonly applied dimensionless groups. In particular, the analysis showed that i) calanchi and river basins have a geometrically similar shape respect to the parameters Rf and Re with a scale factor close to 1, ii) calanchi and river basins are similar respect to the bifurcation and length ratios (λ=1), iii) for the investigated calanchi the Melton number assumes values less than that (0.694) corresponding to the river case and a scale ratio ranging from 0.52 and 0.78 can be used, iv) calanchi and river basins have similar mean relief ratio values (λ=1.13) and v) calanchi present active geomorphic processes and therefore fall in a more juvenile stage with respect to river basins. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. 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

  2. K basins sludge removal sludge pretreatment system

    International Nuclear Information System (INIS)

    Chang, H.L.

    1997-01-01

    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08

  3. 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

  4. Wyoming Basin Rapid Ecoregional Assessment

    Science.gov (United States)

    Carr, Natasha B.; Melcher, Cynthia P.

    2015-08-28

    The Wyoming Basin Rapid Ecoregional Assessment was conducted in partnership with the Bureau of Land Management (BLM). The overall goals of the BLM Rapid Ecoregional Assessments (REAs) are to identify important ecosystems and wildlife habitats at broad spatial scales; identify where these resources are at risk from Change Agents, including development, wildfire, invasive species, disease and climate change; quantify cumulative effects of anthropogenic stressors; and assess current levels of risk to ecological resources across a range of spatial scales and jurisdictional boundaries by assessing all lands within an ecoregion. There are several components of the REAs. Management Questions, developed by the BLM and stakeholders for the ecoregion, identify the regionally significant information needed for addressing land-management responsibilities. Conservation Elements represent regionally significant species and ecological communities that are of management concern. Change Agents that currently affect or are likely to affect the condition of species and communities in the future are identified and assessed. REAs also identify areas that have high conservation potential that are referred to as “large intact areas.” At the ecoregion level, the ecological value of large intact areas is based on the assumption that because these areas have not been greatly altered by human activities (such as development), they are more likely to contain a variety of plant and animal communities and to be resilient and resistant to changes resulting from natural disturbances such as fire, insect outbreaks, and disease.

  5. Permian Basin location recommendation report

    International Nuclear Information System (INIS)

    1983-09-01

    Candidate study areas are screened from the Palo Duro and Dalhart Basin areas using data obtained from studies to date and criteria and specifications that consider: rock geometry; rock characteristics; human intrusion potential; surface characteristics; and environmental and socioeconomic conditions. Two preferred locations are recommended from among these areas for additional characterization to identify potential National Waste Terminal Storage (NWTS) salt repository sites. One location, in northeastern Deaf Smith County and southeastern Oldham County, is underlain by two salt units that meet the adopted screening specifications. The other location, in northcentral Swisher County, is underlain by one salt unit that meets the adopted screening specifications. Both locations have several favorable features, relative to surrounding areas, and no obviously undesirable characteristics. Both lie wholly on the Southern High Plains surface, are in relatively sparsely populated areas, contain no unique land use conflicts, and comprise large enough geographic areas to provide flexibility in site selection. Data gathered to date indicate that these locations contain salt units sufficient in thickness and in depth for the safe construction and operation of the underground facilities under consideration. 93 references, 34 figures, 6 tables

  6. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Science.gov (United States)

    2012-08-01

    ... Basin Conservation Advisory Group, Yakima River Basin Water Enhancement Project, established by the... Water Conservation Program. DATES: The meeting will be held on Tuesday, August 21, 2012, from 1 p.m. to... the implementation of the Water Conservation Program, including the applicable water conservation...

  7. Petroleum systems in rift basins – a collective approach in South-east Asian basins.

    NARCIS (Netherlands)

    Doust, H.; Sumner, D.

    2007-01-01

    This paper synthesizes some of the main conclusions reached in a recent regional review of the Tertiary basins of Southeast Asia, carried out by Shell. Four distinctive types of petroleum systems, correlating with the four main stages of basin evolution (early to late syn-rift and early to late

  8. 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

  9. Rifting Thick Lithosphere - Canning Basin, Western Australia

    Science.gov (United States)

    Czarnota, Karol; White, Nicky

    2016-04-01

    The subsidence histories and architecture of most, but not all, rift basins are elegantly explained by extension of ~120 km thick lithosphere followed by thermal re-thickening of the lithospheric mantle to its pre-rift thickness. Although this well-established model underpins most basin analysis, it is unclear whether the model explains the subsidence of rift basins developed over substantially thick lithosphere (as imaged by seismic tomography beneath substantial portions of the continents). The Canning Basin of Western Australia is an example where a rift basin putatively overlies lithosphere ≥180 km thick, imaged using shear wave tomography. Subsidence modelling in this study shows that the entire subsidence history of the account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted in density by 50-70 kg m-3, which is in line with estimates derived from modelling rare-earth element concentrations of the ~20 Ma lamproites and global isostatic considerations. Together, these results suggest that thick lithosphere thinned to > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal re-thickening of the lithospheric mantle. Our results show that variations in lithospheric thickness place a fundamental control on basin architecture. The discrepancy between estimates of lithospheric thickness derived from subsidence data for the western Canning Basin and those derived from shear wave tomography suggests that the latter technique currently is limited in its ability to resolve lithospheric thickness variations at horizontal half-wavelength scales of <300 km.

  10. Evapotranspiration seasonality across the Amazon Basin

    Science.gov (United States)

    Eiji Maeda, Eduardo; Ma, Xuanlong; Wagner, Fabien Hubert; Kim, Hyungjun; Oki, Taikan; Eamus, Derek; Huete, Alfredo

    2017-06-01

    Evapotranspiration (ET) of Amazon forests is a main driver of regional climate patterns and an important indicator of ecosystem functioning. Despite its importance, the seasonal variability of ET over Amazon forests, and its relationship with environmental drivers, is still poorly understood. In this study, we carry out a water balance approach to analyse seasonal patterns in ET and their relationships with water and energy drivers over five sub-basins across the Amazon Basin. We used in situ measurements of river discharge, and remotely sensed estimates of terrestrial water storage, rainfall, and solar radiation. We show that the characteristics of ET seasonality in all sub-basins differ in timing and magnitude. The highest mean annual ET was found in the northern Rio Negro basin (˜ 1497 mm year-1) and the lowest values in the Solimões River basin (˜ 986 mm year-1). For the first time in a basin-scale study, using observational data, we show that factors limiting ET vary across climatic gradients in the Amazon, confirming local-scale eddy covariance studies. Both annual mean and seasonality in ET are driven by a combination of energy and water availability, as neither rainfall nor radiation alone could explain patterns in ET. In southern basins, despite seasonal rainfall deficits, deep root water uptake allows increasing rates of ET during the dry season, when radiation is usually higher than in the wet season. We demonstrate contrasting ET seasonality with satellite greenness across Amazon forests, with strong asynchronous relationships in ever-wet watersheds, and positive correlations observed in seasonally dry watersheds. Finally, we compared our results with estimates obtained by two ET models, and we conclude that neither of the two tested models could provide a consistent representation of ET seasonal patterns across the Amazon.

  11. 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...

  12. Desert basins of the Southwest

    Science.gov (United States)

    Leake, Stanley A.; Konieczki, Alice D.; Rees, Julie A.H.

    2000-01-01

    Ground water is among the Nation’s most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner. Ground-water resources in the Southwest are among the most overused in the United States. Natural recharge to aquifers is low and pumping in many areas has resulted in lowering of water tables. The consequences of large-scale removal of water from storage are becoming increasingly evident. These consequences include land subsidence; loss of springs, streams, wetlands and associated habitat; and degradation of water quality. Water managers are now seeking better ways of managing ground-water resources while looking for supplemental sources of water. This fact sheet reviews basic information on ground water in the desert basins of the Southwest. Also described are some activities of the U.S. Geological Survey (USGS) that are providing scientific information for sustainable management of ground-water resources in the Southwest. Ground-water sustainability is defined as developing and using ground water in a way that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences.

  13. Performance of Hayabusa2 DCAM3-D Camera for Short-Range Imaging of SCI and Ejecta Curtain Generated from the Artificial Impact Crater Formed on Asteroid 162137 Ryugu (1999 JU3)

    Science.gov (United States)

    Ishibashi, K.; Shirai, K.; Ogawa, K.; Wada, K.; Honda, R.; Arakawa, M.; Sakatani, N.; Ikeda, Y.

    2017-07-01

    Deployable Camera 3-D (DCAM3-D) is a small high-resolution camera equipped on Deployable Camera 3 (DCAM3), one of the Hayabusa2 instruments. Hayabusa2 will explore asteroid 162137 Ryugu (1999 JU3) and conduct an impact experiment using a liner shooting device called Small Carry-on Impactor (SCI). DCAM3 will be detached from the Hayabusa2 spacecraft and observe the impact experiment. The purposes of the observation are to know the impact conditions, to estimate the surface structure of asteroid Ryugu, and to understand the physics of impact phenomena on low-gravity bodies. DCAM3-D requires high imaging performance because it has to image and detect multiple targets of different scale and radiance, i.e., the faint SCI before the shot from 1-km distance, the bright ejecta generated by the impact, and the asteroid. In this paper we report the evaluation of the performance of the CMOS imaging sensor and the optical system of DCAM3-D. We also describe the calibration of DCAM3-D. We confirmed that the imaging performance of DCAM3-D satisfies the required values to achieve the purposes of the observation.

  14. Groundwater quality in the Northern Coast Ranges Basins, California

    Science.gov (United States)

    Mathany, Timothy M.; Belitz, Kenneth

    2015-01-01

    The Northern Coast Ranges (NOCO) study unit is 633 square miles and consists of 35 groundwater basins and subbasins (California Department of Water Resources, 2003; Mathany and Belitz, 2015). These basins and subbasins were grouped into two study areas based primarily on locality. The groundwater basins and subbasins located inland, not adjacent to the Pacific Ocean, were aggregated into the Interior Basins (NOCO-IN) study area. The groundwater basins and subbasins adjacent to the Pacific Ocean were aggregated into the Coastal Basins (NOCO-CO) study area (Mathany and others, 2011).

  15. Corrosion in ICPP fuel storage basins

    International Nuclear Information System (INIS)

    Dirk, W.J.

    1993-09-01

    The Idaho Chemical Processing Plant currently stores irradiated nuclear fuel in fuel storage basins. Historically, fuel has been stored for over 30 years. During the 1970's, an algae problem occurred which required higher levels of chemical treatment of the basin water to maintain visibility for fuel storage operations. This treatment led to higher levels of chlorides than seen previously which cause increased corrosion of aluminum and carbon steel, but has had little effect on the stainless steel in the basin. Corrosion measurements of select aluminum fuel storage cans, aluminum fuel storage buckets, and operational support equipment have been completed. Aluminum has exhibited good general corrosion rates, but has shown accelerated preferential attack in the form of pitting. Hot dipped zinc coated carbon steel, which has been in the basin for approximately 40 years, has shown a general corrosion rate of 4 mpy, and there is evidence of large shallow pits on the surface. A welded Type 304 stainless steel corrosion coupon has shown no attack after 13 years exposure. Galvanic couples between carbon steel welded to Type 304 stainless steel occur in fuel storage yokes exposed to the basin water. These welded couples have shown galvanic attack as well as hot weld cracking and intergranular cracking. The intergranular stress corrosion cracking is attributed to crevices formed during fabrication which allowed chlorides to concentrate

  16. Satellite altimetry over large hydrological basins

    Science.gov (United States)

    Calmant, Stephane

    2015-04-01

    The use of satellite altimetry for hydrological applications, either it is basin management or hydrological modeling really started with the 21st century. Before, during two decades, the efforts were concentrated on the data processing until a precision of a few decimeters could be achieved. Today, several web sites distribute hundreds of series spread over hundeds of rivers runing in the major basins of the world. Among these, the Amazon basin has been the most widely studied. Satellite altimetry is now routinely used in this transboundary basin to predict discharges ranging over 4 orders of magnitude. In a few years, satellite altimetry should evolve dramatically. This year, we should see the launchs of Jason-3 and that of Sentinel-3A operating in SAR mode. With SAR, the accuracy and resolution of a growing number of measurements should be improved. In 2020, SWOT will provide a full coverage that will join in a unique framework all the previous and forthcoming missions. These technical and thematical evolutions will be illustrated by examples taken in the Amazon and Congo basin.

  17. 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

  18. The age of volcanic tuffs from the Upper Freshwater Molasse (North Alpine Foreland Basin) and their possible use for tephrostratigraphic correlations across Europe for the Middle Miocene

    Science.gov (United States)

    Rocholl, Alexander; Schaltegger, Urs; Gilg, H. Albert; Wijbrans, Jan; Böhme, Madelaine

    2018-03-01

    The Middle Miocene Upper Freshwater Molasse sediments represent the last cycle of clastic sedimentation during the evolution of the North Alpine Foreland Basin. They are characterized by small-scale lateral and temporal facies changes that make intra-basin stratigraphic correlations at regional scale difficult. This study provides new U-Pb zircon ages as well as revised 40Ar/39Ar data of volcanic ash horizons in the Upper Freshwater Molasse sediments from southern Germany and Switzerland. In a first and preliminary attempt, we propose their possible correlation to other European tephra deposits. The U-Pb zircon data of one Swiss (Bischofszell) and seven southern German (Zahling, Hachelstuhl, Laimering, Unterneul, Krumbad, Ponholz) tuff horizons indicate eruption ages between roughly 13.0 and 15.5 Ma. The stratigraphic position of the Unterneul and Laimering tuffs, bracketing the ejecta of the Ries impact (Brockhorizon), suggests that the Ries impact occurred between 14.93 and 15.00 Ma, thus assigning the event to the reversed chron C5Bn1r (15.032-14.870 Ma) which is in accordance with paleomagnetic evidence. We combine our data with published ages of tuff horizons from Italy, Switzerland, Bavaria, Styria, Hungary, and Romania to derive a preliminary tephrochronological scheme for the Middle Miocene in Central Europe in the age window from 13.2 to 15.5 Ma. The scheme is based on the current state of knowledge that the Carpathian-Pannonian volcanic field was the only area in the region producing explosive calc-alkaline felsic volcanism. This preliminary scheme will require verification by more high-quality ages complemented by isotopic, geochemical and paleomagnetic data.

  19. Performance analysis of double basin solar still with evacuated tubes

    International Nuclear Information System (INIS)

    Hitesh N Panchal; Shah, P. K.

    2013-01-01

    Solar still is a very simple device, which is used for solar distillation process. In this research work, double basin solar still is made from locally available materials. Double basin solar still is made in such a way that, outer basin is exposed to sun and lower side of inner basin is directly connected with evacuated tubes to increase distillate output and reducing heat losses of a solar still. The overall size of the lower basin is about 1006 mm x 325 mm x 380 mm, the outer basin is about 1006 mm x 536 mm x 100 mm Black granite gravel is used to increase distillate output by reducing quantity of brackish or saline water in the both basins. Several experiments have conducted to determine the performance of a solar still in climate conditions of Mehsana (latitude of 23 degree 59' and longitude of 72 degree 38'), Gujarat, like a double basin solar still alone, double basin solar still with different size black granite gravel, double basin solar still with evacuated tubes and double basin solar still with evacuated tubes and different size black granite gravel. Experimental results show that, connecting evacuated tubes with the lower side of the inner basin increases daily distillate output of 56% and is increased by 60%, 63% and 67% with average 10 mm, 20 mm and 30 mm size black granite gravel. Economic analysis of present double basin solar still is 195 days. (authors)

  20. Tulare Lake Basin Hydrology and Hydrography: A Summary of the Movement of Water and Aquatic Species

    Science.gov (United States)

    Summary of the historic and current hydrology of the Tulare Lake Basin (Basin) describing past, present and potential future movement of water out of the Basin, and potential movement of bioiogical organisms and toxicants within and outside of the Basin.

  1. 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).

  2. Electricity, development and cooperation in mediterranean basin

    International Nuclear Information System (INIS)

    Fabra, J.

    1992-01-01

    Energy consumption along the southern rim of the Mediterranean basin is increasing much more quickly than on the northern side, in accordance with the different industrialization and urbanization rates. Over the last two decades, electric power consumption has been increasing throughout the basin at a rate exceeding not only that of total energy consumption but even that of the economy itself. The various electric power development strategies the countries of the Mediterranean have developed differ widely depending on the available energy resources they have. Power distribution systems are a strategic element of co-operation in the Mediterranean basin. Though all of these strategies involve cost trade-offs between diversification of energy sources, domestic supply and environmental protection, difficulties exist that may curtail the development of these programs. 2 figs., 4 tabs

  3. Environmental education for river-basin planning

    Energy Technology Data Exchange (ETDEWEB)

    Saha, S K

    1980-08-01

    Harmonious intervention in land use, a result of environmental education and good planning, can increase the social and economic benefits without precluding development. Modern river basin planning began as a US innovation in 1874 over the subject of water regulation in the west. The Tennessee Valley Authority (TVA) was devised as a state tool for comprehensive river basin planning and development. The TVA example was not repeated in the other 10 US basins by the Corps of Engineers and the Bureau of Reclamation, although the concept of unified development has survived as a three-part relationship of physical,biological, and human forces in which any malfunctioning of one subsystem affects the others. This is evident in problems of water transfer from agricultural to industrial functions and changes to drainage patterns. The potential damage from ignoring these relationships can be avoided with true interdisciplinary communications. 24 references, 2 tables. (DCK)

  4. Configuration Management Plan for K Basins

    International Nuclear Information System (INIS)

    Weir, W.R.; Laney, T.

    1995-01-01

    This plan describes a configuration management program for K Basins that establishes the systems, processes, and responsibilities necessary for implementation. The K Basins configuration management plan provides the methodology to establish, upgrade, reconstitute, and maintain the technical consistency among the requirements, physical configuration, and documentation. The technical consistency afforded by this plan ensures accurate technical information necessary to achieve the mission objectives that provide for the safe, economic, and environmentally sound management of K Basins and the stored material. The configuration management program architecture presented in this plan is based on the functional model established in the DOE Standard, DOE-STD-1073-93, open-quotes Guide for Operational Configuration Management Programclose quotes

  5. Deep controls on intraplate basin inversion

    DEFF Research Database (Denmark)

    Nielsen, S.B.; Stephenson, Randell Alexander; Schiffer, Christian

    2014-01-01

    Basin inversion is an intermediate-scale manifestation of continental intraplate deformation, which produces earthquake activity in the interior of continents. The sedimentary basins of central Europe, inverted in the Late Cretaceous– Paleocene, represent a classic example of this phenomenon....... It is known that inversion of these basins occurred in two phases: an initial one of transpressional shortening involving reverse activation of former normal faults and a subsequent one of uplift of the earlier developed inversion axis and a shift of sedimentary depocentres, and that this is a response...... to changes in the regional intraplate stress field. This European intraplate deformation is considered in thecontext of a new model of the present-day stress field of Europe (and the North Atlantic) caused by lithospheric potential energy variations. Stresses causingbasin inversion of Europe must have been...

  6. Engineering assessment of 105 K basin monorails

    International Nuclear Information System (INIS)

    Frier, W.A.

    1995-01-01

    The engineering assessment of the 105 K Basins monorails was performed to provide the engineering analysis to justify the existing basin north-south monorail capacity. The existing monorails have a capacity of 2400 lbs posted on the north-south monorails. The engineering assessment concluded that the monorail, hanger system, and trolleys all rate for a 2000 lb capacity. Based upon a 2,500 lb trolley load, the monorails, the hanger system, and the double trolley hoist system will rate for 2,500 lbs. The single trolley hoist system for handling the fuel canisters and the trolley systems used in the various transfer areas are limited by manufacturers to 2,000 lbs. Therefore, it is concluded from this engineering assessment that the 2,400 lb capacity posting for the north-south basin monorails is appropriate

  7. Compaction and sedimentary basin analysis on Mars

    Science.gov (United States)

    Gabasova, Leila R.; Kite, Edwin S.

    2018-03-01

    Many of the sedimentary basins of Mars show patterns of faults and off-horizontal layers that, if correctly understood, could serve as a key to basin history. Sediment compaction is a possible cause of these patterns. We quantified the possible role of differential sediment compaction for two Martian sedimentary basins: the sediment fill of Gunjur crater (which shows concentric graben), and the sediment fill of Gale crater (which shows outward-dipping layers). We assume that basement topography for these craters is similar to the present-day topography of complex craters that lack sediment infill. For Gunjur, we find that differential compaction produces maximum strains consistent with the locations of observed graben. For Gale, we were able to approximately reproduce the observed layer orientations measured from orbiter image-based digital terrain models, but only with a >3 km-thick donut-shaped past overburden. It is not immediately obvious what geologic processes could produce this shape.

  8. Water utilization in the Snake River Basin

    Science.gov (United States)

    Hoyt, William Glenn; Stabler, Herman

    1935-01-01

    The purpose of this report is to describe the present utilization of the water in the Snake River Basin with special reference to irrigation and power and to present essential facts concerning possible future utilization. No detailed plan of development is suggested. An attempt has been made, however, to discuss features that should be taken into account in the formulation of a definite plan of development. On account of the size of the area involved, which is practically as large as the New England States and New York combined, and the magnitude of present development and future possibilities, considerable details have of necessity been omitted. The records of stream flow in the basin are contained in the reports on surface water supply published annually by the Geological Survey. These records are of the greatest value in connection with the present and future regulation and utilization of the basin's largest asset water.

  9. Water security evaluation in Yellow River basin

    Science.gov (United States)

    Jiang, Guiqin; He, Liyuan; Jing, Juan

    2018-03-01

    Water security is an important basis for making water security protection strategy, which concerns regional economic and social sustainable development. In this paper, watershed water security evaluation index system including 3 levels of 5 criterion layers (water resources security, water ecological security and water environment security, water disasters prevention and control security and social economic security) and 24 indicators were constructed. The entropy weight method was used to determine the weights of the indexes in the system. The water security index of 2000, 2005, 2010 and 2015 in Yellow River basin were calculated by linear weighting method based on the relative data. Results show that the water security conditions continue to improve in Yellow River basin but still in a basic security state. There is still a long way to enhance the water security in Yellow River basin, especially the water prevention and control security, the water ecological security and water environment security need to be promoted vigorously.

  10. Acid/Caustic Basins: Environmental information document

    International Nuclear Information System (INIS)

    Ward, J.W.; Johnson, W.F.; Marine, I.W.

    1986-12-01

    There are six Acid/Caustic Basins at SRP, all of which are located in the reactor and separations areas. These basins are unlined earthen depressions with nominal dimensions of 15.2 m in length x 15.2 m in width x 2.1 m in depth. They were used to provide mixing and partial neutralization of dilute sulfuric acid and sodium hydroxide solutions from water treatment facilities before these solutions were discharged to tributaries of local streams. Closure options considered for the Acid/Caustic Basins are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical contaminants are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via general pathways for the three postulated closure options. A cost estimate for each closure was also made

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

  13. Paleohydrogeology of the San Joaquin basin, California

    Science.gov (United States)

    Wilson, A.M.; Garven, G.; Boles, J.R.

    1999-01-01

    Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In our numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than ???2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography-to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

  14. Great Basin geologic framework and uranium favorability

    International Nuclear Information System (INIS)

    Larson, L.T.; Beal, L.H.

    1978-01-01

    Work on this report has been done by a team of seven investigators assisted over the project span by twenty-three undergraduate and graduate students from May 18, 1976 to August 19, 1977. The report is presented in one volume of text, one volume or Folio of Maps, and two volumes of bibliography. The bibliography contains approximately 5300 references on geologic subjects pertinent to the search for uranium in the Great Basin. Volume I of the bibliography lists articles by author alphabetically and Volume II cross-indexes these articles by location and key word. Chapters I through IV of the Text volume and accompanying Folio Map Sets 1, 2, 3, 4, and 5, discuss the relationship of uranium to rock and structural environments which dominate the Great Basin. Chapter 5 and Map Sets 6 and 7 provide a geochemical association/metallogenic grouping of mineral occurrences in the Great Basin along with information on rock types hosting uranium. Chapter VI summarizes the results of a court house claim record search for 'new' claiming areas for uranium, and Chapter VII along with Folio Map Set 8 gives all published geochronological data available through April 1, 1977 on rocks of the Great Basin. Chapter VIII provides an introduction to a computer analysis of characteristics of certain major uranium deposits in crystalline rocks (worldwide) and is offered as a suggestion of what might be done with uranium in all geologic environments. We believe such analysis will assist materially in constructing exploration models. Chapter IX summarizes criteria used and conclusions reached as to the favorability of uranium environments which we believe to exist in the Great Basin and concludes with recommendations for both exploration and future research. A general summary conclusion is that there are several geologic environments within the Great Basin which have considerable potential and that few, if any, have been sufficiently tested

  15. Hydrogeology of the West Siberian Basin

    International Nuclear Information System (INIS)

    Foley, M.G.; Bradley, D.J.; Cole, C.R.

    1996-01-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in extensive radioactive contaminant releases to the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. We have assumed that ground-water flow in the West Siberian Basin is topographically driven, with recharge to the basin occurring in the highlands on the west, east, and south, and internal discharge localized in numerous river valleys and lakes that ultimately discharge north to the ocean. We are modeling the regional hydrogeology as three-dimensional, steady-state, saturated flow that is recharged from above. We acquired topographic, geologic, hydrostratigraphic, hydrogeologic, and water-balance data for the West Siberian Basin and constructed a regional water table. We correlated and combined 70 different rock types derived from published descriptions of West Siberian Basin rocks into 17 rock types appropriate for assignment of hydrogeologic properties on the basis of spatial heterogeneity and constituent (i.e., sand, silt, and clay) diversity. Examination of resulting three-dimensional assemblages of rock types showed that they were consistent with published and inferred paleogeography and depositional processes. Calibrating the basin's moisture balance (i.e., recharge and discharge) to the derived water table determined plausible input parameter values for unknowns such as hydraulic conductivities. The general directions of calculated ground-water flow suggest that major rivers act as discharge areas, with upwelling below the rivers extending down into the basement rocks, and that ground-water divides that penetrate the entire thickness of the model are evident between major rivers

  16. The "normal" elongation of river basins

    Science.gov (United States)

    Castelltort, Sebastien

    2013-04-01

    The spacing between major transverse rivers at the front of Earth's linear mountain belts consistently scales with about half of the mountain half-width [1], despite strong differences in climate and rock uplift rates. Like other empirical measures describing drainage network geometry this result seems to indicate that the form of river basins, among other properties of landscapes, is invariant. Paradoxically, in many current landscape evolution models, the patterns of drainage network organization, as seen for example in drainage density and channel spacing, seem to depend on both climate [2-4] and tectonics [5]. Hovius' observation [1] is one of several unexplained "laws" in geomorphology that still sheds mystery on how water, and rivers in particular, shape the Earth's landscapes. This narrow range of drainage network shapes found in the Earth's orogens is classicaly regarded as an optimal catchment geometry that embodies a "most probable state" in the uplift-erosion system of a linear mountain belt. River basins currently having an aspect away from this geometry are usually considered unstable and expected to re-equilibrate over geological time-scales. Here I show that the Length/Width~2 aspect ratio of drainage basins in linear mountain belts is the natural expectation of sampling a uniform or normal distribution of basin shapes, and bears no information on the geomorphic processes responsible for landscape development. This finding also applies to Hack's [6] law of river basins areas and lengths, a close parent of Hovius' law. [1]Hovius, N. Basin Res. 8, 29-44 (1996) [2]Simpson, G. & Schlunegger, F. J. Geophys. Res. 108, 2300 (2003) [3]Tucker, G. & Bras, R. Water Resour. Res. 34, 2751-2764 (1998) [4]Tucker, G. & Slingerland, R. Water Resour. Res. 33, 2031-2047 (1997) [5]Tucker, G. E. & Whipple, K. X. J. Geophys. Res. 107, 1-1 (2002) [6]Hack, J. US Geol. Surv. Prof. Pap. 294-B (1957)

  17. 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

  18. Colorado River basin sensitivity to disturbance impacts

    Science.gov (United States)

    Bennett, K. E.; Urrego-Blanco, J. R.; Jonko, A. K.; Vano, J. A.; Newman, A. J.; Bohn, T. J.; Middleton, R. S.

    2017-12-01

    The Colorado River basin is an important river for the food-energy-water nexus in the United States and is projected to change under future scenarios of increased CO2emissions and warming. Streamflow estimates to consider climate impacts occurring as a result of this warming are often provided using modeling tools which rely on uncertain inputs—to fully understand impacts on streamflow sensitivity analysis can help determine how models respond under changing disturbances such as climate and vegetation. In this study, we conduct a global sensitivity analysis with a space-filling Latin Hypercube sampling of the model parameter space and statistical emulation of the Variable Infiltration Capacity (VIC) hydrologic model to relate changes in runoff, evapotranspiration, snow water equivalent and soil moisture to model parameters in VIC. Additionally, we examine sensitivities of basin-wide model simulations using an approach that incorporates changes in temperature, precipitation and vegetation to consider impact responses for snow-dominated headwater catchments, low elevation arid basins, and for the upper and lower river basins. We find that for the Colorado River basin, snow-dominated regions are more sensitive to uncertainties. New parameter sensitivities identified include runoff/evapotranspiration sensitivity to albedo, while changes in snow water equivalent are sensitive to canopy fraction and Leaf Area Index (LAI). Basin-wide streamflow sensitivities to precipitation, temperature and vegetation are variable seasonally and also between sub-basins; with the largest sensitivities for smaller, snow-driven headwater systems where forests are dense. For a major headwater basin, a 1ºC of warming equaled a 30% loss of forest cover, while a 10% precipitation loss equaled a 90% forest cover decline. Scenarios utilizing multiple disturbances led to unexpected results where changes could either magnify or diminish extremes, such as low and peak flows and streamflow timing

  19. MONOMIALS AND BASIN CYLINDERS FOR NETWORK DYNAMICS.

    Science.gov (United States)

    Austin, Daniel; Dinwoodie, Ian H

    We describe methods to identify cylinder sets inside a basin of attraction for Boolean dynamics of biological networks. Such sets are used for designing regulatory interventions that make the system evolve towards a chosen attractor, for example initiating apoptosis in a cancer cell. We describe two algebraic methods for identifying cylinders inside a basin of attraction, one based on the Groebner fan that finds monomials that define cylinders and the other on primary decomposition. Both methods are applied to current examples of gene networks.

  20. Water resources of the Chad Basin Region

    Directory of Open Access Journals (Sweden)

    Franklyn R. Kaloko

    2013-07-01

    Full Text Available River basin development is seen as a very effective means of improving agricultural productivity. In the Chad Basin area of the Sahelian Zone of the West African Sub-Region, the water resources have been harnessed to ensure viable agricultural programmes for Nigeria. However,the resultant successes have met by many problems that range from physical to socio-economic and of which water losses have been the most threatening. The study has called for the use of Hexa.deconal (C1-OH film on the water surface of the Chad as a means of reducing evaporation.

  1. Ripple Ring Basins on Ganymede and Callisto

    Science.gov (United States)

    Croft, S. K.

    1985-01-01

    The unusual morphology of the Valhalla multiple or ripple-ring basin in Callisto was totally unexpected in light of the morphologies of large impact structures on the terrestrial planets. Two other ripple-ring basins (RRB's), Asgard and a smaller structure near the crater Adlinda are also described. Several additional RRB's were found on Callisto, an example of which is shown. A previously unrecognized RRB on Ganymede was also found. An image and geologic sketch map of this RRB are shown. Morphometric and positional data for all known RRB's are given.

  2. 13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    form and process of drainage basins that may be widely ... ferruginous tropical soil on basement complex rock (Areola ... landuse pattern control the infiltration loss, the distribution of ... the water intercepted by Ogbere drainage basin to longer ...

  3. Basin and Range Province, Western US, USGS Grids #3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  4. Basin and Range Province, Western US, USGS Grids #2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  5. Basin and Range Province, Western US, USGS Grids, #1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  6. Hydrologic Sub-basins of Greenland, Version 1

    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...

  7. Early sedentary economy in the basin of Mexico.

    Science.gov (United States)

    Niederberger, C

    1979-01-12

    Artifactual and nonartifactual evidence from the lacustrine shores of the Chalco-Xochimilco Basin suggest the existence of fully sedentary human communities in the Basin of Mexico from at least the sixth millennium B.C.

  8. Ferromanganese nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhari, P.; Pattan, J.N.

    In order to delineate a mine site for ferromanganese nodules, extensive surveys were conducted in Central Indian Ocean Basin. Mapping of the basin by multibeam swath bathymetry (Hydrosweep) has revealed many new bottom relief features...

  9. Basin and Range Province, Western US, USGS Grids #5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  10. Basin and Range Province, Western US, USGS Grids #4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  11. 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

  12. 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

  13. 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

  14. K West basin isolation barrier leak rate test

    International Nuclear Information System (INIS)

    Whitehurst, R.; McCracken, K.; Papenfuss, J.N.

    1994-01-01

    This document establishes the procedure for performing the acceptance test on the two isolation barriers being installed in K West basin. This acceptance test procedure shall be used to: First establish a basin water loss rate prior to installation of the two isolation barriers between the main basin and the discharge chute in K-Basin West. Second, perform an acceptance test to verify an acceptable leakage rate through the barrier seals

  15. Hydrology of the Johnson Creek Basin, Oregon

    Science.gov (United States)

    Lee, Karl K.; Snyder, Daniel T.

    2009-01-01

    The Johnson Creek basin is an important resource in the Portland, Oregon, metropolitan area. Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the cities of Milwaukie, Portland, and Gresham, and rural and agricultural areas of Multnomah and Clackamas Counties. The basin has changed as a result of agricultural and urban development, stream channelization, and construction of roads, drains, and other features characteristic of human occupation. Flooding of Johnson Creek is a concern for the public and for water management officials. The interaction of the groundwater and surface-water systems in the Johnson Creek basin also is important. The occurrence of flooding from high groundwater discharge and from a rising water table prompted this study. As the Portland metropolitan area continues to grow, human-induced effects on streams in the Johnson Creek basin will continue. This report provides information on the groundwater and surface-water systems over a range of hydrologic conditions, as well as the interaction these of systems, and will aid in management of water resources in the area. High and low flows of Crystal Springs Creek, a tributary to Johnson Creek, were explained by streamflow and groundwater levels collected for this study, and results from previous studies. High flows of Crystal Springs Creek began in summer 1996, and did not diminish until 2000. Low streamflow of Crystal Springs Creek occurred in 2005. Flow of Crystal Springs Creek related to water-level fluctuations in a nearby well, enabling prediction of streamflow based on groundwater level. Holgate Lake is an ephemeral lake in Southeast Portland that has inundated residential areas several times since the 1940s. The water-surface elevation of the lake closely tracked the elevation of the water table in a nearby well, indicating that the occurrence of the lake is an expression of the water table. Antecedent conditions of the groundwater level and autumn

  16. Lunar and Planetary Science XXXVI, Part 7

    Science.gov (United States)

    2005-01-01

    Topics discussed include: Lunar Geologic Mapping: Preliminary Mapping of Copernicus Quad High-Resolution Topography of Layers in the Valles Marineris Via Thermoclinometry ; The Critical Importance of Data Reduction Calibrations in the Interpretability of S-type Asteroid Spectra; (sup 238)U-(sup 206)Pb Age and Uranium-Lead Isotope Systematics of Mare Basalt 10017; Morphological Investigations of Martian Spherules, Comparisons to Collected Terrestrial Counterparts; The Vapor Pressure of Palladium at Temperatures up to 1973K; Areas of Favorable Illumination at the Lunar Poles Calculated from Topography; An Indigenous Origin for the South Pole-Aitken Basin Thorium Anomaly; Ar-Ar Ages of Nakhlites Y000593, NWA998, and Nakhla and CRE Ages of NWA998; Experiments on the Acoustic Properties of Titan-like Atmospheres; Analysis of Downstream Transitions in Morphology and Structure of Lava Channels on Mars; Structure and Bonding of Carbon in Clays from CI Carbonaceous Chondrites; Comparison of Three Hydrogen Distributions at the Equator of Mars; An Impact Origin for the Foliation of Ordinary Chondrites; A New Micrometeorite Collection from Antarctica and Its Preliminary Characterization by Microobservation, Microanalysis and Magnetic Methods; Volcanic Plumes and Plume Deposits on Io; Results of the Alpha-Particle-X-Ray Spectrometer on Board of the Mars Exploration Rovers; Effects of Oceans on Atmospheric Loss During the Stage of Giant Impacts; and Identification of Predominant Ferric Signatures in Association to the Martian Sulfate Deposits

  17. The Interior Columbia Basin Ecosystem Management Project: scientific assessment.

    Science.gov (United States)

    1999-01-01

    This CD-ROM contains digital versions (PDF) of the major scientific documents prepared for the Interior Columbia Basin Ecosystem Management Project (ICBEMP). "A Framework for Ecosystem Management in the Interior Columbia Basin and Portions of the Klamath and Great Basins" describes a general planning model for ecosystem management. The "Highlighted...

  18. 305 Building K basin mockup facility functions and requirements

    International Nuclear Information System (INIS)

    Steele, R.M.

    1994-01-01

    This document develops functions and requirements for installation and operation of a cold mockup test facility within the 305 Building. The test facility will emulate a portion of a typical spent nuclear fuel storage basin (e.g., 105-KE Basin) to support evaluation of equipment and processes for safe storage and disposition of the spent nuclear fuel currently within the K Basins

  19. Integrated Worker Radiation Dose Assessment for the K Basins

    International Nuclear Information System (INIS)

    NELSON, J.V.

    1999-01-01

    This report documents an assessment of the radiation dose workers at the K Basins are expected to receive in the process of removing spent nuclear fuel from the storage basins. The K Basins (K East and K West) are located in the Hanford 100K Area

  20. 100KE/KW fuel storage basin surface volumetric factors

    International Nuclear Information System (INIS)

    Conn, K.R.

    1996-01-01

    This Supporting Document presents calculations of surface Volumetric factors for the 100KE and 100KW Fuel Storage Basins. These factors relate water level changes to basin loss or additions of water, or the equivalent water displacement volumes of objects added to or removed from the basin

  1. Riddled Basins of Attraction for Synchronized Type-I Intermittency

    DEFF Research Database (Denmark)

    Mancher, Martin; Nordahn, Morten; Mosekilde, Erik

    1998-01-01

    Chaotic mortion resticted to an invariant subspace of total phase space may be associated with basins of attraction that are riddled with holes belonging to the basin of another limiting state. We study the emergence of such basins of two coupled one-dimensional maps, each exhibiting type...

  2. Detailed bathymetric surveys in the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.; KameshRaju, K.A.; Ramprasad, T.; George, P.; Jaisankar, S.

    Over 420,000 line kilometers of echo-sounding data was collected in the Central Indian Basin. This data was digitized, merged with navigation data and a detailed bathymetric map of the Basin was prepared. The Basin can be broadly classified...

  3. 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

  4. 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.

  5. Basin Subsegments from LDEQ source data, Geographic NAD83, LOSCO (2004) [basin_subsegments_LDEQ_2004

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a polygon data set of watershed basin subsegments for Louisiana. The dataset was developed for the LDEQ Office of Water Resources' watershed assessment and...

  6. Rifte Guaritas basin compartmentation in Camaqua

    International Nuclear Information System (INIS)

    Preissler, A; Rolim, S; Philipp, R.

    2010-01-01

    The study contributes to the knowledge of the tectonic evolution of the Guaritas rift basin in Camaqua. Were used aero magnetic geophysical data for modeling the geometry and the depth of the structures and geological units. The research was supported in processing and interpretation of Aster images (EOS-Terra), which were extracted from geophysical models and digital image

  7. Climatology of the interior Columbia River basin.

    Science.gov (United States)

    Sue A. Ferguson

    1999-01-01

    This work describes climate means and trends in each of three major ecological zones and 13 ecological reporting units in the interior Columbia River basin. Widely differing climates help define each major zone and reporting unit, the pattern of which is controlled by three competing air masses: marine, continental, and arctic. Paleoclimatic evidence and historical...

  8. Climate change adaptation in European river basins

    NARCIS (Netherlands)

    Huntjens, P.; Pahl-Wostl, C.; Grin, J.

    2010-01-01

    This paper contains an assessment and standardized comparative analysis of the current water management regimes in four case-studies in three European river basins: the Hungarian part of the Upper Tisza, the Ukrainian part of the Upper Tisza (also called Zacarpathian Tisza), Alentejo Region

  9. Alboran Basin, southern Spain - Part I: Geomorphology

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, A. [Secretaria General de Pesca Maritima, Corazon de Maria, 8, 28002 Madrid (Spain); Ballesteros, M.; Rivera, J.; Acosta, J. [Instituto Espanol de Oceanografia, Corazon de Maria, 8, 28002 Madrid (Spain); Montoya, I. [Universidad Juan Carlos I, Campus de Mostoles, Madrid (Spain); Uchupi, E. [Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States)

    2008-01-15

    Bathymetric, 3D relief and shaded relief maps created from multibeam echo-sounding data image the morphology of the Alboran Basin, a structural low along the east-west-trending Eurasian-African plates boundary. Topographic features in the basin are the consequence of volcanism associated with Miocene rifting, rift and post-rift sedimentation, and recent faulting resulting from the convergence of the African-Eurasian plates. Pleistiocene glacially induced regressions/transgressions when the sea level dropped to about 150 m below its present level gas seeps and bottom currents. Recent faulting and the Pleistocene transgressions/regressions led to mass-wasting, formation of turbidity currents and canyon erosion on the basin's slopes. Recent fault traces at the base of the northern basin slope have also served as passageways for thermogenic methane, the oxidation of which by bacteria led to the formation of carbonate mounds along the fault intercepts on the sea floor. Expulsion of thermogenic or biogenic gas has led to the formation of pockmarks; erosion by bottom currents has resulted in the formation of moats around seamounts and erosion of the seafloor of the Alboran Ridge and kept the southern edge of the 36 10'N high sediment free. (author)

  10. 105-KE Basin Pilot Run design plan

    International Nuclear Information System (INIS)

    Sherrell, D.L.

    1994-01-01

    This document identifies all design deliverables and procedures applicable to the 105-KE Basin Pilot Run. It also establishes a general design strategy, defines interface control requirements, and covers planning for mechanical, electrical, instrument/control system, and equipment installation design

  11. Downstreamness: A concept to analyse basin closure

    NARCIS (Netherlands)

    van Oel, P.R.; Krol, Martinus S.; Hoekstra, Arjen Ysbert

    2011-01-01

    In many places in the world, increasing water demands have led to the development of infrastructure for freshwater storage and irrigation. Especially in water-scarce regions, this development has led to a growing number of concerns about basin closure. These concerns ask for a structured approach

  12. Integrated studies of Azraq Basin in Jordan

    Science.gov (United States)

    Mohammed Shahbaz; B. Sunna

    2000-01-01

    Many historical indications of the eastern Mediterranean Basin exhibit climatic changes or alterations effecting the status of water resources, hence, effecting human-kind and the quality of life. It is essential to deeply understand the nature of climates and geological structures employing state of the art techniques to assess rainfall, runoff, and floods that...

  13. Summary status of K Basins sludge characterization

    International Nuclear Information System (INIS)

    Baker, R.B.

    1995-01-01

    A number of activities are underway as part of the Spent Nuclear Fuels Project (SNFP) related to the processing and disposing of sludge in the 105-K Basins (K Basins). Efforts to rigorously define data requirements for these activities are being made using the Data Quality Objectives (DQO) process. Summaries of current sludge characterization data are required to both help support this DQO process and to allow continued progress with on-going engineering activities (e.g., evaluations of disposal alternatives). This document provides the status of K Basins sludge characterization data currently available to the Nuclear Fuel Evaluations group. This group is tasked by the SNFP to help develop and maintain the characterization baseline for the K Basins. The specific objectives of this document are to: (1) provide a current summary (and set of references) of sludge characterization data for use by SNFP initiatives, to avoid unnecessary duplication of effort and to support on-going initiatives; (2) submit these data to an open forum for review and comment, and identify additional sources of significant data that may be available; (3) provide a summary of current data to use as part of the basis to develop requirements for additional sludge characterization data through the DQO process; (4) provide an overview of the intended activities that will be used to develop and maintain the sludge characterization baseline

  14. Basins of Attraction for Chimera States

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Panaggio, Mark; Abrams, Daniel

    2016-01-01

    Chimera states---curious symmetry-broken states in systems of identical coupled oscillators---typically occur only for certain initial conditions. Here we analyze their basins of attraction in a simple system comprised of two populations. Using perturbative analysis and numerical simulation we...

  15. Hydrologic studies within the Pasco Basin

    International Nuclear Information System (INIS)

    Spane, F.A. Jr.

    1982-09-01

    As part of the Basalt Waste Isolation Project (BWIP), hydrologic studies are being performed to provide an evaluation of groundwater systems within the Columbia River Basalt Group. These studies are focused on the Hanford Site, which is located within the Pasco Basin in south-central Washington. Hydrologic studies within the Pasco Basin involve the areal and vertical characterization of hydraulic head, hydrologic properties, and hydrochemical content for the various basalt groundwater systems. Currently, in excess of 150 test intervals have been tested for hydraulic properties, while in excess of 80 horizons have been analyzed for hydrochemical characteristics at about 30 borehole sites within the Pasco Basin. Data obtained from these studies provide input for numerical modeling of groundwater flow and solute transport. Results from numerical modeling are used for evaluating potential waste migration as a function of space and time. In the Pasco Basin, geologic structures influence groundwater flow patterns within basalt aquifer systems. Potentiometric data and hydrochemical evidence collected from recent studies indicate that geologic structures act as areal hydrologic barriers and in some instances, regions of enhanced vertical conductivity. 8 figures

  16. Tectonic inversion in the Wandel Sea Basin

    DEFF Research Database (Denmark)

    Svennevig, Kristian; Guarnieri, Pierpaolo; Stemmerik, Lars

    2016-01-01

    Sheet and an upper Hondal Elv Thrust Sheet separated by a subhorizontal fault: the Central Detachment. The style of deformation and the structures described are interpreted as the result of Paleocene-Eocene N-S directed compression resulting in basin inversion with strike-slip faults only having minor...

  17. Canada Basin Acoustic Propagation Experiment (CANAPE)

    Science.gov (United States)

    2015-09-30

    acoustic communications, acoustic navigation, or acoustic remote sensing of the ocean interior . RELATED PROJECTS The 2015 CANAPE pilot study was a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Canada Basin Acoustic Propagation Experiment (CANAPE...ocean structure. Changes in sea ice and the water column affect both acoustic propagation and ambient noise. This implies that what was learned

  18. Policy and Practice – River Basins

    International Development Research Centre (IDRC) Digital Library (Canada)

    Ms Suruchi Bhadwal

    nature of rivers in the northern belt- inextricably linked. Exacerbated water stress in some areas. Increasing demands – food and drinking water needs. Socioeconomics. CC Impacts. Glacier-fed basins in the. North. Glacier melt and river flooding,. GLOFs, landslides. Unique socio-cultural settings and political differences.

  19. Hydrogeophysical investigation of Southern Anambra Basin Nigeria ...

    African Journals Online (AJOL)

    The analytical relationship between the Dar Zarrouk parameters and the hydraulic characteristics were used to assess the hydrogeological condition of the basin. These have led to inferences about the aquifer hydraulic conductivities and transmissivities and K product across the area. Consequently favourable areas have ...

  20. Pyritized ooids from the Arabian Sea basin

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.; Rao, Ch.M.; Reddy, N.P.C.

    Pyritized ooids in association with turbidites were observed in a box core collected at a depth of 3627 m from the Arabian Sea Basin. Ooids having a shallow water origin were transported to the present depth by turbidity currents or slumping...

  1. Crustal structure of the Khartoum Basin, Sudan

    CSIR Research Space (South Africa)

    El Tahir, N

    2013-05-01

    Full Text Available Basin ranges between 33 and 37 km, with an average of 35 km, and that the crustal Vp/Vs ratio ranges from 1.74 to 1.81, with an average of 1.78. From the joint inversion of receiver functions and Rayleigh wave group velocities,we obtained similar results...

  2. Raptors of the Izdrevaya River Basin, Russia

    Directory of Open Access Journals (Sweden)

    Elvira G. Nikolenko

    2017-05-01

    Full Text Available This article compiles the results of episodic visits of the aurhoes to the basin of the Izdrevaya river during 2012–2016. The main goals of those visits were: to figure out the species composition of nesting fauna of birds of prey, estabishing the manner of nesting pairs’ distribution and designing a system of nestboxes for different species of birds of prey and owls. 8 species of Falconiformes are present in the Izdrevaya river basin, 4 of which are nesting, and 3 species of Strigiformes, 2 of which are nesting. The Black Kite (Milvus migrans has maximum density in the Izdrevaya river basin – 51.83 ind./100km2 (n=93. The Common Buzzard (Buteo buteo is the second in number after the Black Kite, its density being 8.88 ind/100km2 of the total area. The Ural Owl (Strix uralensis, encountered only on two territories in 2012, inhabited 4 nestboxes in 2013 as the result of biotechnical measures taken, and its number increased to 8 pairs successfully breeding in the nextboxes in 2016. Main negative factors for birds of prey in the Izdrevaya river basin were established: electrocution on power lines, illegal logging, illegal construction of dams and the construction of waste-sorting plant with a range of solid municipal waste.

  3. Middle Rio Grande Basin Research Report 2008

    Science.gov (United States)

    Deborah M. Finch; Catherine Dold

    2008-01-01

    An ecosystem is rarely static. A natural system composed of plants, animals, and microorganisms interacting with an area's physical factors, an ecosystem is always fluctuating and evolving. But sometimes, often at the hands of humans, ecosystems change too much. Such is the case with many of the ecosystems of the Middle Rio Grande Basin of New Mexico.

  4. K Basin sludge dissolution engineering study

    International Nuclear Information System (INIS)

    Westra, A.G.

    1998-01-01

    The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel

  5. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. VI. Radio Constraints on a Relativistic Jet and Predictions for Late-time Emission from the Kilonova Ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, K. D.; Berger, E.; Fong, W.; Williams, P. K. G.; Guidorzi, C.; Margutti, R.; Metzger, B. D.; Annis, J.; Blanchard, P. K.; Brout, D.; Brown, D. A.; Chen, H. -Y.; Chornock, R.; Cowperthwaite, P. S.; Drout, M.; Eftekhari, T.; Frieman, J.; Holz, D. E.; Nicholl, M.; Rest, A.; Sako, M.; Soares-Santos, M.; Villar, V. A.

    2017-10-16

    We present Very Large Array (VLA) and Atacama Large Millimeter/sub-millimeter Array ALMA radio observations of GW\\,170817, the first Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo gravitational wave (GW) event from a binary neutron star merger and the first GW event with an electromagnetic (EM) counterpart. Our data include the first observations following the discovery of the optical transient at both the centimeter ($13.7$ hours post merger) and millimeter ($2.41$ days post merger) bands. We detect faint emission at 6 GHz at 19.47 and 39.23 days after the merger, but not in an earlier observation at 2.46 d. We do not detect cm/mm emission at the position of the optical counterpart at frequencies of 10-97.5 GHz at times ranging from 0.6 to 30 days post merger, ruling out an on-axis short gamma-ray burst (SGRB) for energies $\\gtrsim 10^{48}$ erg. For fiducial SGRB parameters, our limits require an observer viewer angle of $\\gtrsim 20^{\\circ}$. The radio and X-ray data can be jointly explained as the afterglow emission from an SGRB with a jet energy of $\\sim 10^{49}-10^{50}$ erg that exploded in a uniform density environment with $n\\sim 10^{-4}-10^{-2}$ cm$^{-3}$, viewed at an angle of $\\sim 20^{\\circ}-40^{\\circ}$ from the jet axis. Using the results of our light curve and spectral modeling, in conjunction with the inference of the circumbinary density, we predict the emergence of late-time radio emission from the deceleration of the kilonova (KN) ejecta on a timescale of $\\sim 5-10$ years that will remain detectable for decades with next-generation radio facilities, making GW\\,170817 a compelling target for long-term radio monitoring.

  6. Strike-slip tectonics and Quaternary basin formation along the Vienna Basin fault system inferred from Bouguer gravity derivatives

    NARCIS (Netherlands)

    Salcher, B. C.; Meurers, B.; Smit, J.; Decker, K.; HöLzel, M.; Wagreich, M.

    2012-01-01

    The Vienna Basin at the transition between the Alpine and Carpathian belt hosts a number of large Pleistocene sub-basins forming along an active continental scale strike-slip fault (Vienna Basin strike-slip fault). We utilize first-order derivatives from industrial Bouguer gravity data to unravel

  7. 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

  8. 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

  9. 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.

  10. Modeling Fluid Flow in Faulted Basins

    Directory of Open Access Journals (Sweden)

    Faille I.

    2014-07-01

    Full Text Available This paper presents a basin simulator designed to better take faults into account, either as conduits or as barriers to fluid flow. It computes hydrocarbon generation, fluid flow and heat transfer on the 4D (space and time geometry obtained by 3D volume restoration. Contrary to classical basin simulators, this calculator does not require a structured mesh based on vertical pillars nor a multi-block structure associated to the fault network. The mesh follows the sediments during the evolution of the basin. It deforms continuously with respect to time to account for sedimentation, erosion, compaction and kinematic displacements. The simulation domain is structured in layers, in order to handle properly the corresponding heterogeneities and to follow the sedimentation processes (thickening of the layers. In each layer, the mesh is unstructured: it may include several types of cells such as tetrahedra, hexahedra, pyramid, prism, etc. However, a mesh composed mainly of hexahedra is preferred as they are well suited to the layered structure of the basin. Faults are handled as internal boundaries across which the mesh is non-matching. Different models are proposed for fault behavior such as impervious fault, flow across fault or conductive fault. The calculator is based on a cell centered Finite Volume discretisation, which ensures conservation of physical quantities (mass of fluid, heat at a discrete level and which accounts properly for heterogeneities. The numerical scheme handles the non matching meshes and guaranties appropriate connection of cells across faults. Results on a synthetic basin demonstrate the capabilities of this new simulator.

  11. Two characteristics of planar intertwined basins of attraction

    International Nuclear Information System (INIS)

    Ding Changming

    2012-01-01

    Highlights: ► A new mathematical definition of intertwined basins of attraction is proposed. ► Basins are intertwined iff a limit set of stable manifold contains at least two points. ► Basins are intertwined iff the closure of stable manifold is not arc-connected. ► The intertwining property is preserved by topologically equivalent dynamical systems. - Abstract: In this paper, we investigate the intertwined basins of attraction for planar dynamical systems. We prove that the intertwining property is preserved by topologically equivalent systems. Two necessary and sufficient conditions for a planar system having intertwined basins are given.

  12. Distribution, Statistics, and Resurfacing of Large Impact Basins on Mercury

    Science.gov (United States)

    Fassett, Caleb I.; Head, James W.; Baker, David M. H.; Chapman, Clark R.; Murchie, Scott L.; Neumann, Gregory A.; Oberst, Juergen; Prockter, Louise M.; Smith, David E.; Solomon, Sean C.; hide

    2012-01-01

    The distribution and geological history of large impact basins (diameter D greater than or equal to 300 km) on Mercury is important to understanding the planet's stratigraphy and surface evolution. It is also informative to compare the density of impact basins on Mercury with that of the Moon to understand similarities and differences in their impact crater and basin populations [1, 2]. A variety of impact basins were proposed on the basis of geological mapping with Mariner 10 data [e.g. 3]. This basin population can now be re-assessed and extended to the full planet, using data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Note that small-to- medium-sized peak-ring basins on Mercury are being examined separately [4, 5]; only the three largest peak-ring basins on Mercury overlap with the size range we consider here. In this study, we (1) re-examine the large basins suggested on the basis of Mariner 10 data, (2) suggest additional basins from MESSENGER's global coverage of Mercury, (3) assess the size-frequency distribution of mercurian basins on the basis of these global observations and compare it to the Moon, and (4) analyze the implications of these observations for the modification history of basins on Mercury.

  13. In situ characterization of Hanford K Basins fuel

    Energy Technology Data Exchange (ETDEWEB)

    Pitner, A.L.

    1998-01-06

    Irradiated N Reactor uranium metal fuel is stored underwater in the Hanford K East and K West Basins. In K East Basin, fuel is stored in open canisters and defected fuel is free to react with the basin water. In K West Basin, the fuel is stored in sealed canisters filled with water containing a corrosion inhibitor (potassium nitrite). To gain a better understanding of the physical condition of the fuel in these basins, visual surveys using high resolution underwater cameras were conducted. The inspections included detailed lift and look examinations of a number of fuel assemblies from selected canisters in each basin. These examinations formed the bases for selecting specific fuel elements for laboratory testing and analyses as prescribed in the characterization plan for Hanford K Basin Spent Nuclear Fuel.

  14. 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.

  15. 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

  16. 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

  17. 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).

  18. Hotspots within the Transboundary Selenga River Basin

    Science.gov (United States)

    Kasimov, Nikolay; Lychagin, Mikhail; Chalov, Sergey

    2013-04-01

    Gathering the efficient information on water pollution of transboundary river systems remains the crucial task in international water management, environmental pollution control and prevention health problems. Countries, located in the low parts of the river basins, depend on the water strategy and water use in the adjacent countries, located upstream. Surface water pollution is considered to be the most serious problem, facing the above-mentioned countries. Large efforts in terms of field measurement campaigns and (numerical) transport modeling are then typically needed for relevant pollution prediction and prevention. Russian rivers take inflow from 8 neighboring countries. Among them there are 2 developing economies - People Republic of China and Mongolia, which are located in water-scarce areas and thus solve their water-related problems through the consumption of international water. Negative change of water runoff and water quality in the foreign part of transboundary river is appeared inside Russian territory with more or less delay. The transboundary river system of Selenga is particularly challenging, being the biggest tributary of Lake Baikal which is the largest freshwater reservoir in the world. Selenga River contributes about 50 % of the total inflow into Baikal. It originates in the mountainous part of Mongolia and then drains into Russia. There are numerous industries and agricultural activities within the Selenga drainage basin that affect the water quality of the river system. Absence of the single monitoring system and predictive tools for pollutants transport in river system requires large efforts in understanding sources of water pollution and implemented data on the relevant numerical systems for the pollution prediction and prevention. Special investigations in the Selenga river basin (Mongolia and Russia) were done to assess hot spots and understand state-of-the art in sediment load, water chemistry and hydrobiology of transboundary systems

  19. Vertical movement in mare basins: relation to mare emplacement, basin tectonics, and lunar thermal history

    International Nuclear Information System (INIS)

    Solomon, S.C.

    1979-01-01

    The spatial and temporal relationships of linear rilles and mare ridges in the Serenitatis basin region of the moon are explained by a combination of lithospheric flexure in response to basin loading by basalt fill and a time-dependent global stress due to the thermal evolution of the lunar interior. The pertinent tectonic observations are the radial distance of basin concentric rilles or graben from the mare center; the location and orientation of mare ridges, interpreted as compressive features; and the restriction of graben formation to times older than 3.6 +- 0.2 b.y. ago, while ridge formation continued after emplacement of the youngest mare basalt unit (approx.3 b.y. ago). The locations of the graben are consistent with the geometry of the mare basalt load expected from the dimensions of multiring basins for values of the thickness of the elastic lithosphere beneath Serenitatis in the range 25--50 km at 3.6--3.8 b.y. ago. The locations and orientations of mare ridges are consistent with the load inferred from surface mapping and subsurface radar reflections for values of the elastic lithosphere thickness near 100 km at 3.0--3.4 b.y. ago. The thickening of the lithosphere beneath a major basin during the evolution of mare volcanism is thus clearly evident in the tectonics. The cessation of rille formation and the prolonged period of ridge formation are attributed to a change in the global horizontal thermal stress from extension to compression as the moon shifted from net expansion to overall cooling and contraction. Severe limits as placed on the range of possible lunar thermal histories. The zone of horizontal extensional stresses peripheral to mare loads favors the edge of mare basins as the preferred sites for mare basalt magma eruption in the later stages of mare fill, although subsidence may lead to accumulation of such young lavas in basin centers

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  2. 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.

  3. Nutrient mitigation in a temporary river basin.

    Science.gov (United States)

    Tzoraki, Ourania; Nikolaidis, Nikolaos P; Cooper, David; Kassotaki, Elissavet

    2014-04-01

    We estimate the nutrient budget in a temporary Mediterranean river basin. We use field monitoring and modelling tools to estimate nutrient sources and transfer in both high and low flow conditions. Inverse modelling by the help of PHREEQC model validated the hypothesis of a losing stream during the dry period. Soil and Water Assessment Tool model captured the water quality of the basin. The 'total daily maximum load' approach is used to estimate the nutrient flux status by flow class, indicating that almost 60% of the river network fails to meet nitrogen criteria and 50% phosphate criteria. We recommend that existing well-documented remediation measures such as reforestation of the riparian area or composting of food process biosolids should be implemented to achieve load reduction in close conjunction with social needs.

  4. Protecting air basins from harmful discharges

    Energy Technology Data Exchange (ETDEWEB)

    Yankovskiy, S S

    1983-01-01

    The work is a brief description of the content of the reports delivered at the seminar entitled Protecting the Air Basin from Harmful Discharges of the Machine Building Enterprises, which took place at the All Union Exhibit of the Achievements of the National Economy of the USSR (VDNKh) in 1982. Representatives of different ministries and agencies, scientific research institutes (NII), planning and design and other specialized organizations, institutes of higher learning (vuz) and enterprises from different branches of industry took part in the work of the seminar. The seminar noted measures to eliminate deficiencies which occur in individual enterprises of the branch and measures to improve the work to improve protection of the air basin from harmful discharges of machine building enterprises.

  5. Susquehanna River Basin Hydrologic Observing System (SRBHOS)

    Science.gov (United States)

    Reed, P. M.; Duffy, C. J.; Dressler, K. A.

    2004-12-01

    In response to the NSF-CUAHSI initiative for a national network of Hydrologic Observatories, we propose to initiate the Susquehanna River Basin Hydrologic Observing System (SRBHOS), as the northeast node. The Susquehanna has a drainage area of 71, 410 km2. From the headwaters near Cooperstown, NY, the river is formed within the glaciated Appalachian Plateau physiographic province, crossing the Valley and Ridge, then the Piedmont, before finishing its' 444 mile journey in the Coastal Plain of the Chesapeake Bay. The Susquehanna is the major source of water and nutrients to the Chesapeake. It has a rich history in resource development (logging, mining, coal, agriculture, urban and heavy industry), with an unusual resilience to environmental degradation, which continues today. The shallow Susquehanna is one of the most flood-ravaged rivers in the US with a decadal regularity of major damage from hurricane floods and rain-on-snow events. As a result of this history, it has an enormous infrastructure for climate, surface water and groundwater monitoring already in place, including the nations only regional groundwater monitoring system for drought detection. Thirty-six research institutions have formed the SRBHOS partnership to collaborate on a basin-wide network design for a new scientific observing system. Researchers at the partner universities have conducted major NSF research projects within the basin, setting the stage and showing the need for a new terrestrial hydrologic observing system. The ultimate goal of SRBHOS is to close water, energy and solute budgets from the boundary layer to the water table, extending across plot, hillslope, watershed, and river basin scales. SRBHOS is organized around an existing network of testbeds (legacy watershed sites) run by the partner universities, and research institutions. The design of the observing system, when complete, will address fundamental science questions within major physiographic regions of the basin. A nested

  6. Basins of attraction in human balance

    Science.gov (United States)

    Smith, Victoria A.; Lockhart, Thurmon E.; Spano, Mark L.

    2017-12-01

    Falls are a recognized risk factor for unintentional injuries among older adults, accounting for a large proportion of fractures, emergency department visits, and urgent hospitalizations. Human balance and gait research traditionally uses linear or qualitative tests to assess and describe human motion; however, human motion is neither a simple nor a linear process. The objective of this research is to identify and to learn more about what factors affect balance using nonlinear dynamical techniques, such as basin boundaries. Human balance data was collected using dual force plates for leans using only ankle movements as well as for unrestricted leans. Algorithms to describe the basin boundary were created and compared based on how well each method encloses the experimental data points as well as captures the differences between the two leaning conditions.

  7. Strontium isotope stratigraphy of the Pelotas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Zerfass, Geise de Santana dos Anjos, E-mail: geise.zerfass@petrobras.com.br [Petroleo Brasileiro S.A. (PETROBRAS/CENPES/PDGEO/BPA), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento Leopoldo Americo Miguez de Mello; Chemale Junior, Farid, E-mail: fchemale@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias; Moura, Candido Augusto Veloso, E-mail: candido@ufpa.br [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Geociencias. Dept. de Geoquimica e Petrologia; Costa, Karen Badaraco, E-mail: karen.costa@usp.br [Instituto Oceanografico, Sao Paulo, SP (Brazil); Kawashita, Koji, E-mail: koji@usp.br [Unversidade de Sao Paulo (USP), SP (Brazil). Centro de Pesquisas Geocronologicas

    2014-07-01

    Strontium isotope data were obtained from foraminifera shells of the Pelotas Basin Tertiary deposits to facilitate the refinement of the chronostratigraphic framework of this section. This represents the first approach to the acquisition of numerical ages for these strata. Strontium isotope stratigraphy allowed the identification of eight depositional hiatuses in the Eocene-Pliocene section, here classified as disconformities and a condensed section. The reconnaissance of depositional gaps based on confident age assignments represents an important advance considering the remarkably low chronostratigraphic resolution in the Cenozoic section of the Pelotas Basin. The recognition of hiatuses that match hiatuses is based on biostratigraphic data, as well as on global events. Furthermore, a substantial increase in the sedimentation rate of the upper Miocene section was identified. Paleotemperature and productivity trends were identified based on oxygen and carbon isotope data from the Oligocene-Miocene section, which are coherent with worldwide events, indicating the environmental conditions during sedimentation. (author)

  8. Exploratory shaft facility preliminary designs - Permian Basin

    International Nuclear Information System (INIS)

    1983-09-01

    The purpose of the Preliminary Design Report, Permian Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Permian Basin, Texas. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references, 13 tables

  9. 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.; hide

    2015-01-01

    Caloris basin, Mercury's youngest large impact basin, is filled by volcanic plains that are spectrally distinct from surrounding material. Post-plains impact craters of a variety of sizes populate the basin interior, and the spectra of the material they have excavated enable the thickness of the volcanic fill to be estimated and reveal the nature of the subsurface. The thickness of the interior volcanic plains is consistently at least 2.5 km, reaching 3.5 km in places, with thinner fill toward the edge of the basin. No systematic variations in fill thickness are observed with long-wavelength topography or azimuth. The lack of correlation between plains thickness and variations in elevation at large horizontal scales within the basin indicates that plains emplacement must have predated most, if not all, of the changes in long-wavelength topography that affected the basin. There are no embayed or unambiguously buried (ghost) craters with diameters greater than 10 km in the Caloris interior plains. The absence of such ghost craters indicates that one or more of the following scenarios must hold: the plains are sufficiently thick to have buried all evidence of craters that formed between the Caloris impact event and the emplacement of the plains; the plains were emplaced soon after basin formation; or the complex tectonic deformation of the basin interior has disguised wrinkle-ridge rings localized by buried craters. That low-reflectance material (LRM) was exposed by every impact that penetrated through the surface volcanic plains provides a means to explore near-surface stratigraphy. If all occurrences of LRM are derived from a single layer, the subsurface LRM deposit is at least 7.5-8.5 km thick and its top likely once made up the Caloris basin floor. The Caloris-forming impact would have generated a layer of impact melt 3-15 km thick; such a layer could account for the entire thickness of LRM. This material would have been derived from a combination of lower crust

  10. LERF Basin 44 Process Test Plan

    International Nuclear Information System (INIS)

    LUECK, K.J.

    1999-01-01

    This document presents a plan to process a portion of the Liquid Effluent Retention Facility (LERF) Basin 44 wastewater through the 200 Area Effluent Treatment Facility (ETF). The objective of this process test is to determine the most effective/efficient method to treat the wastewater currently stored in LERF Basin 44. The process test will determine the operational parameters necessary to comply with facility effluent discharge permit limits (Ecology 1995) and the Environmental Restoration Disposal Facility (ERDF) acceptance criteria (BHI-00139), while achieving ALARA goals and maintaining the integrity of facility equipment. A major focus of the test plan centers on control of contamination due to leaks and/or facility maintenance. As a pre-startup item, all known leaks will be fixed before the start of the test. During the course of the test, a variety of contamination control measures will be evaluated for implementation during the treatment of the remaining Basin 44 inventory. Of special interest will be techniques and tools used to prevent contamination spread during sampling and when opening contaminated facility equipment/piping. At the conclusion of the test, a post ALARA review will be performed to identify lessons learned from the test run which can be applied to the treatment of the remaining Basin 44 inventory. The volume of wastewater to be treated during this test run is 500,000 gallons. This volume limit is necessary to maintain the ETF radiological inventory limits per the approved authorization basis. The duration of the process test is approximately 30 days

  11. K Basin spent nuclear fuel characterization

    Energy Technology Data Exchange (ETDEWEB)

    LAWRENCE, L.A.

    1999-02-10

    The results of the characterization efforts completed for the N Reactor fuel stored in the Hanford K Basins were Collected and summarized in this single referencable document. This summary provides a ''road map'' for what was done and the results obtained for the fuel characterization program initiated in 1994 and scheduled for completion in 1999 with the fuel oxidation rate measurement under moist inert atmospheres.

  12. South Fork Holston River basin 1988 biomonitoring

    Energy Technology Data Exchange (ETDEWEB)

    Saylor, C.F.; Ahlstedt, S.A.

    1990-06-01

    There is concern over the effects of shifts in land use use practices on the aquatic fauna of streams in the South Fork Holston River basin in northwestern North Carolina and southwestern Virginia. Trout reproduction has noticeably declined in the Watauga River subbasin. The Watauga River and Elk River subbasins have been subjected to commercial and resort development. The Middle fork Holston River and the upper South Fork Holston River subbasins have been affected by agricultural and mining activities, respectively (Cox, 1986). To aid reclamation and management of the South Fork Holston basin, Tennessee Valley Authority (TVA) biologists conducted biomonitoring--including index of biotic integrity and macroinvertebrate sampling--on the Middle Fork Holston, South Fork Holston, Watauga, and Elk Rivers to assess cumulative impairment related to changes in habitat and pollutant loading in these subbasins. Biomonitoring can detect environmental degradation, help document problem areas, and assist in development of strategies for managing water quality. This report discusses the methods and materials and results of the biomonitoring of South Fork Holston River Basin. 13 refs., 5 figs., 12 tabs.

  13. DROUGHT ANALYSIS IN OZANA DRAINAGE BASIN

    Directory of Open Access Journals (Sweden)

    Marina IOSUB

    2016-03-01

    Full Text Available Ozana drainage basin is located at the contact between large landscape units (the Carpathian mountains, the Subcarpathian area, and the plateau region. This placement determines the existence of a complex climate in the region. Despite being small in size, and its extension on an W-E direction, differences can be observed, especially of the way extreme phenomena take place. In the case of droughts, it had different intensities in the mountains, compared to the plateau region. In order to emphasize the different distribution on the territory, several climatic indexes have been calculated, regarding dryness (De Martonne Index, Hellman criterion. The analysis of these indexes at the same monitoring stations (Pluton, Leghin and Dumbrava emphasizes the growth of the drought periods in the plateau region and the fact that they shorten in the mountain area. In the mountainous area, where the land is very well forested, the values of the De Martonne index can reach 45.4, and in the plateau regions, where the forest associations are sparse, the values dropped to 30.6. According to the Hellman criterion, several differences can be emphasized, at basin level. In the mountainous region, there is only one month that, at a multi-annual level, has stood up among the rest, as being excessively droughty, while in the median /central region of the basin, three months have been identified, that have such potential, as well as five months, at Dumbrava.

  14. Amazonis and Utopia Planitiae: Martian Lacustrine basins

    Science.gov (United States)

    Scott, David H.; Rice, James W., Jr.; Dohm, James M.; Chapman, Mary G.

    1992-01-01

    Amazonis and Utopia Planitiae are two large (greater than 10(exp 6) sq. km) basins on Mars having morphological features commonly associated with former lakes. The investigation of these areas is an extension of our previous paleolake studies in the Elysium basin. Using Viking images, we are searching for familiar geologic forms commonly associated with standing bodies of water on Earth. Like Elysium, the two basins exhibit terraces and lineations resembling shorelines, etched and infilled floors with channel-like sinuous markings in places, inflow channels along their borders, and other geomorphic indicators believed to be related to the presence of water and ice. In some areas these features are better displayed than in others where they may be very tenuous; their value as indicators can be justified only by their association with related features. Even though these postulated paleolakes are very young in the Martian stratigraphic sequence, their shoreline features are poorly preserved and they are probably much older than large Pleistocene lakes on Earth.

  15. Mackenzie Basin impact study: Interim report 1

    International Nuclear Information System (INIS)

    Cohen, S.J.

    1993-01-01

    The Mackenzie Basin Impact Study (MIBS) is a six-year study undertaken to assess the potential impacts on the Mackenzie River Basin region and its inhabitants. The study framework, structure, organization, methods, and data are described. Highlights of work to date are reviewed. The MBIS employs scenarios of future warmer climates and changes in population and economic conditions. Research is coordinated by an interagency working committee and research activities cover 28 areas including permafrost, hydrology, sea ice, boreal ecosystems, freshwater fish, wildlife, forestry, agriculture, tourism, community studies, and defense. Six issues have been identified: interjurisdictional water management, sustainability of native lifestyles, economic development opportunities, infrastructure and buildings, and sustainability of ecosystems. An integrated assessment approach is used in the MBIS, combining scientific and indigenous traditional knowledge and attempting to include all interactions that occur between sectors. Two methods are being developed: socio-economic integration using a resource accounting framework, and an integrated land assessment framework. Four scenarios of warmer climates have been developed, all showing increased precipitation for the basin as a whole. Moderate growth in the resource sector is predicted. Preliminary results of some research are reported, including a lengthened open-water season in the Beaufort Sea accompanied by a greater extent of open water. 44 figs., 16 tabs

  16. Streamflow Prediction in Ungauged, Irrigated Basins

    Science.gov (United States)

    Zhang, M.; Thompson, S. E.

    2016-12-01

    The international "predictions in ungauged basins" or "PUB" effort has broadened and improved the tools available to support water resources management in sparsely observed regions. These tools have, however, been primarily focused on regions with limited diversion of surface or shallow groundwater resources. Incorporating anthropogenic activity into PUB methods is essential given the high level of development of many basins. We extended an existing stochastic framework used to predict the flow duration curve to explore the effects of irrigation on streamflow dynamics. Four canonical scenarios were considered in which irrigation water was (i) primarily sourced from water imports, (ii) primarily sourced from direct in-channel diversions, (iii) sourced from shallow groundwater with direct connectivity to stream channels, or (iv) sourced from deep groundwater that is indirectly connected to surface flow via a shallow aquifer. By comparing the predicted flow duration curves to those predicted by accounting for climate and geomorphic factors in isolation, specific "fingerprints" of human water withdrawals could be identified for the different irrigation scenarios, and shown to be sensitive to irrigation volumes and scheduling. The results provide a first insight into PUB methodologies that could be employed in heavily managed basins.

  17. Frost risks in the Mantaro river basin

    Directory of Open Access Journals (Sweden)

    G. Trasmonte

    2008-04-01

    Full Text Available As part of the study on the Mantaro river basin's (central Andes of Perú current vulnerability to climate change, the temporal and spatial characteristics of frosts were analysed. These characteristics included intensity, frequency, duration, frost-free periods, area distribution and historical trends. Maps of frost risk were determined for the entire river basin, by means of mathematical algorithms and GIS (Geographic Information Systems tools, using minimum temperature – 1960 to 2002 period, geomorphology, slope, land-use, types of soils, vegetation and life zones, emphasizing the rainy season (September to April, when the impacts of frost on agriculture are most severe. We recognized four categories of frost risks: low, moderate, high and critical. The critical risks (with a very high probability of occurrence were related to high altitudes on the basin (altitudes higher than 3800 m a.s.l., while the low (or null probability of occurring risks were found in the lower zones (less than 2500 m a.s.l.. Because of the very intense agricultural activity and the high sensitivity of the main crops (Maize, potato, artichoke in the Mantaro valley (altitudes between 3100 and 3300 m a.s.l., moderate to high frost risks can be expected, with a low to moderate probability of occurrence. Another significant result was a positive trend of 8 days per decade in the number of frost days during the rainy season.

  18. Scaling issues in sustainable river basin management

    Science.gov (United States)

    Timmerman, Jos; Froebich, Jochen

    2014-05-01

    Sustainable river basin management implies considering the whole river basin when managing the water resources. Management measures target at dividing the water over different uses (nature, agriculture, industry, households) thereby avoiding calamities like having too much, too little or bad quality water. Water management measures are taken at the local level, usually considering the sub-national and sometimes national effects of such measures. A large part of the world's freshwater resources, however, is contained in river basins and groundwater systems that are shared by two or more countries. Sustainable river basin management consequently has to encompass local, regional, national and international scales. This requires coordination over and cooperation between these levels that is currently compressed into the term 'water governance' . Governance takes into account that a large number of stakeholders in different regimes (the principles, rules and procedures that steer management) contribute to policy and management of a resource. Governance includes the increasing importance of basically non-hierarchical modes of governing, where non-state actors (formal organizations like NGOs, private companies, consumer associations, etc.) participate in the formulation and implementation of public policy. Land use determines the run-off generation and use of irrigation water. Land use is increasingly determined by private sector initiatives at local scale. This is a complicating factor in the governance issue, as in comparison to former developments of large scale irrigation systems, planning institutions at state level have then less insight on actual water consumption. The water management regime of a basin consequently has to account for the different scales of water management and within these different scales with both state and non-state actors. The central elements of regimes include the policy setting (the policies and water management strategies), legal setting

  19. Geochemistry of the Late Paleozoic cherts in the Youjiang Basin: Implications for the basin evolution

    Directory of Open Access Journals (Sweden)

    Huang Hu

    2013-10-01

    Full Text Available We analyzed the major and rare earth element compositions of siliceous deposits from the Upper Devonian Liujiang Formation, Lower Carboniferous Luzhai Formation, Lower–Middle Permian Sidazhai Formation and Tapi Formation, which are widely distributed as bedded cherts in the interplatform basinal successions of the Youjiang Basin. The Liujiang Formation and Luzhai Formation cherts generally have high Al/(Al+Fe+Mn values (0.38–0.94 and are non-hydrothermal cherts. These cherts are generally characterized by moderately negative Ce anomalies and high Y/Ho values relatived to PAAS, indicating that the Youjiang Basin might have evolved into an open rift basin during the Late Devonian–Early Carboniferous. The Sidazhai Formation cherts from Ziyun generally have high Al/(Al+Fe+Mn values (0.60–0.78, suggesting negligible contribution from a hydrothermal component. The Sidazhai Formation cherts from Hechi and the Tapi Formation cherts from Malipo generally have low Al/(Al+Fe+Mn values (0.09–0.41, indicating an intense hydrothermal input. Relatived to the Sidazhai Formation cherts, the Tapi Formation cherts have higher Ce/Ce* values (0.68±0.19 and lower Y/Ho values (41.83±13.27, which may be affected by the terrigenous input from the Vietnam Block. The Sidazhai Formation cherts from Ziyun and Hechi exhibit negative Ce anomalies (0.43±0.12, 0.33±0.17, respectively with high Y/Ho values (57.44±16.20, 46.02±4.27, respectively, resembling the geochemical characteristics of open-ocean basin cherts. These cherts were deposited on a passive continental margin adjacent to the Babu branch ocean, which may have contributed to upwelling. Detailed spatial studies on geochemical characteristics of the Late Paleozoic cherts can unravel the evolution of the Youjiang Basin.

  20. Quantification of water resources uncertainties in the Luvuvhu sub-basin of the Limpopo river basin

    Science.gov (United States)

    Oosthuizen, N.; Hughes, D.; Kapangaziwiri, E.; Mwenge Kahinda, J.; Mvandaba, V.

    2018-06-01

    In the absence of historical observed data, models are generally used to describe the different hydrological processes and generate data and information that will inform management and policy decision making. Ideally, any hydrological model should be based on a sound conceptual understanding of the processes in the basin and be backed by quantitative information for the parameterization of the model. However, these data are often inadequate in many sub-basins, necessitating the incorporation of the uncertainty related to the estimation process. This paper reports on the impact of the uncertainty related to the parameterization of the Pitman monthly model and water use data on the estimates of the water resources of the Luvuvhu, a sub-basin of the Limpopo river basin. The study reviews existing information sources associated with the quantification of water balance components and gives an update of water resources of the sub-basin. The flows generated by the model at the outlet of the basin were between 44.03 Mm3 and 45.48 Mm3 per month when incorporating +20% uncertainty to the main physical runoff generating parameters. The total predictive uncertainty of the model increased when water use data such as small farm and large reservoirs and irrigation were included. The dam capacity data was considered at an average of 62% uncertainty mainly as a result of the large differences between the available information in the national water resources database and that digitised from satellite imagery. Water used by irrigated crops was estimated with an average of about 50% uncertainty. The mean simulated monthly flows were between 38.57 Mm3 and 54.83 Mm3 after the water use uncertainty was added. However, it is expected that the uncertainty could be reduced by using higher resolution remote sensing imagery.

  1. NATURAL GAS RESOURCES IN DEEP SEDIMENTARY BASINS

    Energy Technology Data Exchange (ETDEWEB)

    Thaddeus S. Dyman; Troy Cook; Robert A. Crovelli; Allison A. Henry; Timothy C. Hester; Ronald C. Johnson; Michael D. Lewan; Vito F. Nuccio; James W. Schmoker; Dennis B. Riggin; Christopher J. Schenk

    2002-02-05

    From a geological perspective, deep natural gas resources are generally defined as resources occurring in reservoirs at or below 15,000 feet, whereas ultra-deep gas occurs below 25,000 feet. From an operational point of view, ''deep'' is often thought of in a relative sense based on the geologic and engineering knowledge of gas (and oil) resources in a particular area. Deep gas can be found in either conventionally-trapped or unconventional basin-center accumulations that are essentially large single fields having spatial dimensions often exceeding those of conventional fields. Exploration for deep conventional and unconventional basin-center natural gas resources deserves special attention because these resources are widespread and occur in diverse geologic environments. In 1995, the U.S. Geological Survey estimated that 939 TCF of technically recoverable natural gas remained to be discovered or was part of reserve appreciation from known fields in the onshore areas and State waters of the United. Of this USGS resource, nearly 114 trillion cubic feet (Tcf) of technically-recoverable gas remains to be discovered from deep sedimentary basins. Worldwide estimates of deep gas are also high. The U.S. Geological Survey World Petroleum Assessment 2000 Project recently estimated a world mean undiscovered conventional gas resource outside the U.S. of 844 Tcf below 4.5 km (about 15,000 feet). Less is known about the origins of deep gas than about the origins of gas at shallower depths because fewer wells have been drilled into the deeper portions of many basins. Some of the many factors contributing to the origin of deep gas include the thermal stability of methane, the role of water and non-hydrocarbon gases in natural gas generation, porosity loss with increasing thermal maturity, the kinetics of deep gas generation, thermal cracking of oil to gas, and source rock potential based on thermal maturity and kerogen type. Recent experimental simulations

  2. Use of hydrological modelling and isotope techniques in Guvenc basin

    International Nuclear Information System (INIS)

    Altinbilek, D.

    1991-07-01

    The study covers the work performed under Project No. 335-RC-TUR-5145 entitled ''Use of Hydrologic Modelling and Isotope Techniques in Guvenc Basin'' and is an initial part of a program for estimating runoff from Central Anatolia Watersheds. The study presented herein consists of mainly three parts: 1) the acquisition of a library of rainfall excess, direct runoff and isotope data for Guvenc basin; 2) the modification of SCS model to be applied to Guvenc basin first and then to other basins of Central Anatolia for predicting the surface runoff from gaged and ungaged watersheds; and 3) the use of environmental isotope technique in order to define the basin components of streamflow of Guvenc basin. 31 refs, figs and tabs

  3. K Basins fuel encapsulation and storage hazard categorization

    International Nuclear Information System (INIS)

    Porten, D.R.

    1994-12-01

    This document establishes the initial hazard categorization for K-Basin fuel encapsulation and storage in the 100 K Area of the Hanford site. The Hazard Categorization for K-Basins addresses the potential for release of radioactive and non-radioactive hazardous material located in the K-Basins and their supporting facilities. The Hazard Categorization covers the hazards associated with normal K-Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. The criteria categorizes a facility based on total curies per radionuclide located in the facility. Tables 5-3 and 5-4 display the results in section 5.0. In accordance with DOE-STD-1027 and the analysis provided in section 5.0, the K East Basin fuel encapsulation and storage activity and the K West Basin storage are classified as a open-quotes Category 2close quotes Facility

  4. 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

  5. The Agost Basin (Betic Cordillera, Alicante province, Spain): a pull-apart basin involving salt tectonics

    Science.gov (United States)

    Martín-Martín, Manuel; Estévez, Antonio; Martín-Rojas, Ivan; Guerrera, Francesco; Alcalá, Francisco J.; Serrano, Francisco; Tramontana, Mario

    2018-03-01

    The Agost Basin is characterized by a Miocene-Quaternary shallow marine and continental infilling controlled by the evolution of several curvilinear faults involving salt tectonics derived from Triassic rocks. From the Serravallian on, the area experienced a horizontal maximum compression with a rotation of the maximum stress axis from E-W to N-S. The resulting deformation gave rise to a strike-slip fault whose evolution is characterized progressively by three stages: (1) stepover/releasing bend with a dextral motion of blocks; (2) very close to pure horizontal compression; and (3) restraining bend with a sinistral movement of blocks. In particular, after an incipient fracturing stage, faults generated a pull-apart basin with terraced sidewall fault and graben subzones developed in the context of a dextral stepover during the lower part of late Miocene p.p. The occurrence of Triassic shales and evaporites played a fundamental role in the tectonic evolution of the study area. The salty material flowed along faults during this stage generating salt walls in root zones and salt push-up structures at the surface. During the purely compressive stage (middle part of late Miocene p.p.) the salt walls were squeezed to form extrusive mushroom-like structures. The large amount of clayish and salty material that surfaced was rapidly eroded and deposited into the basin, generating prograding fan clinoforms. The occurrence of shales and evaporites (both in the margins of the basin and in the proper infilling) favored folding of basin deposits, faulting, and the formation of rising blocks. Later, in the last stage (upper part of late Miocene p.p.), the area was affected by sinistral restraining conditions and faults must have bent to their current shape. The progressive folding of the basin and deformation of margins changed the supply points and finally caused the end of deposition and the beginning of the current erosive systems. On the basis of the interdisciplinary results

  6. Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists

    DEFF Research Database (Denmark)

    Kalliomäki, Henrik; Torvela, Taija; Moreau, Julien

    2014-01-01

    We present field observations from the Palaeoproterozoic volcano-sedimentary Tampere palaeobasin, where the primary structures have been exceptionally well preserved. We use the observations to construct a new tectonic model for the southeastern margin of the Tampere basin during its inversion...... and subsequent closure. The observed volcano-sedimentary and structural features suggest a change in the local structural style from thick-skinned inversion to thin-skinned thrusting, in order to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic...

  7. Final design review report for K basin dose reduction project

    International Nuclear Information System (INIS)

    Blackburn, L.D.

    1996-01-01

    The strategy for reducing radiation dose originating from radionuclides absorbed in the K East Basin concrete is to raise the pool water level to provide additional shielding. This report documents a final design review for cleaning/coating basin walls and modifying other basin components where appropriate. The conclusion of this review was that the documents developed constitute an acceptable design for the Dose Reduction Project

  8. The water footprint of agricultural products in European river basins

    International Nuclear Information System (INIS)

    Vanham, D; Bidoglio, G

    2014-01-01

    This work quantifies the agricultural water footprint (WF) of production (WF prod, agr ) and consumption (WF cons, agr ) and the resulting net virtual water import (netVW i, agr ) of 365 European river basins for a reference period (REF, 1996–2005) and two diet scenarios (a healthy diet based upon food-based dietary guidelines (HEALTHY) and a vegetarian (VEG) diet). In addition to total (tot) amounts, a differentiation is also made between the green (gn), blue (bl) and grey (gy) components. River basins where the REF WF cons, agr, tot exceeds the WF prod, agr, tot (resulting in positive netVW i, agr, tot values), are found along the London–Milan axis. These include the Thames, Scheldt, Meuse, Seine, Rhine and Po basins. River basins where the WF prod, agr, tot exceeds the WF cons, agr, tot are found in Western France, the Iberian Peninsula and the Baltic region. These include the Loire, Ebro and Nemunas basins. Under the HEALTHY diet scenario, the WF cons, agr, tot of most river basins decreases (max −32%), although it was found to increase in some basins in northern and eastern Europe. This results in 22 river basins, including the Danube, shifting from being net VW importers to being net VW exporters. A reduction (max −46%) in WF cons, agr, tot is observed for all but one river basin under the VEG diet scenario. In total, 50 river basins shift from being net VW importers to being net exporters, including the Danube, Seine, Rhone and Elbe basins. Similar observations are made when only the gn + bl and gn components are assessed. When analysing only the bl component, a different river basin pattern is observed. (letters)

  9. Interim essential and support drawing list for K Basins

    International Nuclear Information System (INIS)

    Langevin, M.J.

    1994-01-01

    This document presents a list of essential and support drawings that have been identified as required to achieve the mission objectives of K Basin and are an integral part of the in-progress K Basins system baselining effort. The drawings listed in the appendix are those drawings required to safely operate K Basins. These drawings will be authenticated through the field verification and design reconstitution programs to ensure that these identified drawings are consistent with design requirements

  10. K basins interim remedial action health and safety plan

    Energy Technology Data Exchange (ETDEWEB)

    DAY, P.T.

    1999-09-14

    The K Basins Interim Remedial Action Health and Safety Plan addresses the requirements of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), as they apply to the CERCLA work that will take place at the K East and K West Basins. The provisions of this plan become effective on the date the US Environmental Protection Agency issues the Record of Decision for the K Basins Interim Remedial Action, currently planned in late August 1999.

  11. Slope effects on SWAT modeling in a mountainous basin

    OpenAIRE

    Yacoub López, Cristina; Pérez Foguet, Agustí

    2013-01-01

    The soil and water assessment tool (SWAT) is a distributed basin model that includes the option of defining spatial discretization in terms of terrain slope. Influence of terrain slope in runoff results from mountain basins is a determining factor in its simulation results; however, its use as a criterion for basin discretization and for the parameter calibration has not yet been analyzed. In this study, this influence is analyzed for calibrations using two different cases. Ten discretization...

  12. Cretaceous sedimentology of the Barmer Basin, Rajasthan, India

    OpenAIRE

    Beaumont, Hazel

    2017-01-01

    The Barmer Basin, western India, is a well-known and prospected petroleum system. However, the Lower Cretaceous Ghaggar-Hakra Formation has not been recognised as basin fill and not documented prior to this study. The formation outcrops in rotational fault blocks at the Sarnoo Hills and surrounding areas, on the eastern Barmer Basin margin. The thesis here describes and analyses the nature and evolution of the formation at both outcrop and within the subsurface, producing facies and depositio...

  13. Water Clarity Simulant for K East Basin Filtration Testing

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Andrew J.

    2006-01-20

    This document provides a simulant formulation intended to mimic the behavior of the suspended solids in the K East (KE) Basin fuel storage pool. The simulant will be used to evaluate alternative filtration apparatus to improve Basin water clarity and to possibly replace the existing sandfilter. The simulant was formulated based on the simulant objectives, the key identified parameters important to filtration, the composition and character of the KE Basin suspended sludge particles, and consideration of properties of surrogate materials.

  14. Geomorphological characterization of endorheic basins in northern Chile

    Science.gov (United States)

    Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

    2011-12-01

    Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1

  15. Remediation of SRS Basins by In Situ Stabilization/Solidification

    International Nuclear Information System (INIS)

    Ganguly, A.

    1999-01-01

    In the late summer of 1998, the Savannah River Site began remediation of two radiologically contaminated basins using in situ stabilization. These two high-risk, unlined basins contain radiological contaminants, which potentially pose significant risks to human health and the environment. The selected remedy involves in situ stabilization/solidification of the contaminated wastes (basin and pipeline soils, pipelines, vegetation, and other debris) followed by installation of a low permeability soil cover

  16. 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

  17. M-area basin closure-Savannah River Site

    International Nuclear Information System (INIS)

    McMullin, S.R.; Horvath, J.G.

    1991-01-01

    M-Area, on the Savannah River Site, processes raw materials and manufactures fuel and target rods for reactor use. Effluent from these processes were discharged into the M-Area settling basin and Lost Lake, a natural wetland. The closure of this basin began in 1988 and included the removal and stabilization of basin fluids, excavation of all contaminated soils from affected areas and Lost Lake, and placement of all materials in the bottom of the emptied basin. These materials were covered with a RCRA style cap, employing redundant barriers of kaolin clay and geosynthetic material. Restoration of excavated uplands and wetlands is currently underway

  18. Gondwana basins and their coal resources in Bangladesh

    International Nuclear Information System (INIS)

    Nehaluddin, M.; Sultan-ul-Islam, M.

    1994-01-01

    Fault bounded five Gondwana basins have been discovered in the north western Bangladesh. Among these basins show considerable amount of coal deposits. The Gondwana rocks are highly formed during the Permo-carboniferous diastrophism and later on acquired dynamic characters. In almost all basins, the Permian rocks overlie the Precambrian basement and underlie either the Tertiary or the Cretaceous sediments, structural, stratigraphic, and depositional history of these basins is more or less similar. The sedimentary sequences are composed of light to dark gray, fine to very coarse grained, sub angular to sub rounded felspathic sandstone, dark grey carbonaceous shale and sandstone, variegated conglomerate and thick coal seams (single seam max. 42.38m). The rocks are often alternated and bear the characteristics of cyclic sedimentation. The depositional environments varied from restricted drainage to open fluvial dominated low to moderate sinuous drainage system. The coal bearing basins were flanked by vegetated and swampy over bank. Age of these coals is suggested to be the late permian. Proved and probable reserves of coal in Jamalganj-Paharpur basin are 670 and 1,460 million metric tons, in Barapukuria basin 303 and 3899 million metric tons; in Barapukuria basin 303 and 389 million metric tons; and in Khalaspir basin 143 and 685 million metric tons respectively. The coal is high volatile, low sulphur, bituminous type. It can be used for different forms of thermal conversion. (author)

  19. Wekiva Basin onsite sewage treatment and disposal system study

    OpenAIRE

    Booher, Paul

    2006-01-01

    Existing onsite systems and aquifer vulnerability in the Wekiva Basin. Recommendations from the Bureau of Onsite Sewage Programs, Division of Environmental Health, Florida Department of Health. (11 slides)

  20. The tritium balance of the Ems river basin

    International Nuclear Information System (INIS)

    Krause, W.J.

    1989-01-01

    For the Ems river basin, as a fine example of a Central European lowland basin, an inventory of the tritium distribution is presented for the hydrologic years 1951 to 1983. On the basis of a balance model, the tritium contents in surface waters and groundwater of the Ems river basin are calculated, using known and extrapolated tritium input data and comparing them with the corresponding values measured since 1974. A survey of tritium flows occurring in this basin is presented, taking meteorologic and hydrologic facts into account. (orig.)

  1. Oil and gas in the Ogaden Basin, Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Du Toit, S.R.; Kurdy, S. [Alconsult International, Calgary, AB (Canada); Asfaw, S.H.; Gessesse, A.A. [Petroleum Operations Dept., Ministry of Mines and Energy, Addis Ababa (Ethiopia)

    1997-09-01

    To date, many of the 47 exploration and development wells drilled in the Ogaden Basin in Ethiopia have exhibited natural oil seeps and oil and gas shows. The Calub gas field and the Hilala oil field occurs in the central part of the 350,000 sq. km. basin. The various units within the basin consist of continental sediments, a regional organic-rich interval close to the Permo-Triassic boundary, organic-rich marine sediments and carbonates. The Ogaden Basin is dissected by several faults that are related to the Ethiopian Rift and may form a component of traps in the Calub-Hilala area.

  2. Geochemical Modeling Of F Area Seepage Basin Composition And Variability

    International Nuclear Information System (INIS)

    Millings, M.; Denham, M.; Looney, B.

    2012-01-01

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Woodlands Grazing Issues in Mediterranean Basin

    Science.gov (United States)

    Campos, P.

    2009-04-01

    In Mediterranean basin, woodlands grazing still continue to be important commercial owners' benefits. These owners manage woodlands vegetations as if they were not at risk of degradation and declining. Frequently, no temporally grazing set-aside is taken into account to avoid overgrazing of annual and perennial vegetations. Although less common, in the northern shore of Mediterranean basin undergrazing might increase the frequency and the number of catastrophic forest fires. This under/over grazing regime occurs in the Mediterranean basin woodlands with contrasted differences on land property rights, local economies and government livestock policy incentives. Spain and Tunisia are examples of these Mediterranean livestock contrasts. Most of Spanish Mediterranean woodlands and livestock herds are large private ownerships and owners could maintain their lands and livestock herds properties on the basis of moderate cash-income compensation against land revaluation and exclusive amenity self-consumption. The later is less tangible benefit and it could include family land legacy, nature enjoyment, country stile of life development, social status and so on. In public woodlands, social and environmental goals -as they are cultural heritage, biodiversity loss mitigation, soil conservation and employment- could maintain market unprofitable woodlands operations. Last three decades Spanish Mediterranean woodlands owners have increased the livestock herds incentivized by government subsidies. As result, grazing rent is pending on the level of European Union and Spanish government livestock subsidies. In this context, Spanish Mediterranean woodlands maintain a high extensive livestock stoking population, which economy could be called fragile and environmentally unsustainable because forest degradation and over/under grazing practices. Tunisian Mediterranean woodlands are state properties and livestock grazing is practice as a free private regimen. Livestock herds are small herd

  8. From stretching to mantle exhumation in a triangular backarc basin (Vavilov basin, Tyrrhenian Sea, Western Mediterranean)

    NARCIS (Netherlands)

    Milia, A.; Torrente, M. M.; Tesauro, M.

    2017-01-01

    In this study, we describe the mode of extension of the Vavilov, a fossil backarc basin, triangle-shaped (approximately 240. km-wide and 200. km-long), located between Sardinia margin to the west and Campania margin to the east. We combine the analysis of recent geophysical and geological data, in

  9. Basin-wide water accounting based on remote sensing data : An application for the Indus Basin

    NARCIS (Netherlands)

    Karimi, P.; Bastiaanssen, W.G.M.; Molden, D.; Cheema, M.J.M.

    2013-01-01

    The paper demonstrates the application of a new water accounting plus (WA+) framework to produce information on depletion of water resources, storage change, and land and water productivity in the Indus basin. It shows how satellite-derived estimates of land use, rainfall, evaporation (E),

  10. A NEW METHOD FOR ENVIRONMENTAL FLOW ASSESSMENT BASED ON BASIN GEOLOGY. APPLICATION TO EBRO BASIN.

    Science.gov (United States)

    2018-02-01

    The determination of environmental flows is one of the commonest practical actions implemented on European rivers to promote their good ecological status. In Mediterranean rivers, groundwater inflows are a decisive factor in streamflow maintenance. This work examines the relationship between the lithological composition of the Ebro basin (Spain) and dry season flows in order to establish a model that can assist in the calculation of environmental flow rates.Due to the lack of information on the hydrogeological characteristics of the studied basin, the variable representing groundwater inflows has been estimated in a very simple way. The explanatory variable used in the proposed model is easy to calculate and is sufficiently powerful to take into account all the required characteristics.The model has a high coefficient of determination, indicating that it is accurate for the intended purpose. The advantage of this method compared to other methods is that it requires very little data and provides a simple estimate of environmental flow. It is also independent of the basin area and the river section order.The results of this research also contribute to knowledge of the variables that influence low flow periods and low flow rates on rivers in the Ebro basin.

  11. Great Basin Factsheet Series 2016 - Information and tools to restore and conserve Great Basin ecosystems

    Science.gov (United States)

    Jeanne C. Chambers

    2016-01-01

    Land managers are responsible for developing effective strategies for conserving and restoring Great Basin ecosystems in the face of invasive species, conifer expansion, and altered fire regimes. A warming climate is magnifying the effects of these threats and adding urgency to implementation of management practices that will maintain or improve ecosystem...

  12. 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

  13. Three-dimensional geologic mapping of the Cenozoic basin fill, Amargosa Desert basin, Nevada and California

    Science.gov (United States)

    Taylor, Emily M.; Sweetkind, Donald S.

    2014-01-01

    Understanding the subsurface geologic framework of the Cenozoic basin fill that underlies the Amargosa Desert in southern Nevada and southeastern California has been improved by using borehole data to construct three-dimensional lithologic and interpreted facies models. Lithologic data from 210 boreholes from a 20-kilometer (km) by 90-km area were reduced to a limited suite of descriptors based on geologic knowledge of the basin and distributed in three-dimensional space using interpolation methods. The resulting lithologic model of the Amargosa Desert basin portrays a complex system of interfingered coarse- to fine-grained alluvium, playa and palustrine deposits, eolian sands, and interbedded volcanic units. Lithologic units could not be represented in the model as a stacked stratigraphic sequence due to the complex interfingering of lithologic units and the absence of available time-stratigraphic markers. Instead, lithologic units were grouped into interpreted genetic classes, such as playa or alluvial fan, to create a three-dimensional model of the interpreted facies data. Three-dimensional facies models computed from these data portray the alluvial infilling of a tectonically formed basin with intermittent internal drainage and localized regional groundwater discharge. The lithologic and interpreted facies models compare favorably to resistivity, aeromagnetic, and geologic map data, lending confidence to the interpretation.

  14. Basin-wide impacts of climate change on ecosystem services in the Lower Mekong Basin

    Science.gov (United States)

    Water resources support more than 60 million people in the Lower Mekong Basin (LMB) and are important for food security—especially rice production—and economic security. This study aims to quantify water yield under near- and long-term climate scenarios and assess the...

  15. 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.

  16. Modified basin-type solar still

    International Nuclear Information System (INIS)

    El-Mously, M.K.; El-Ashry, M.Y.; El-Iraqi, M.H.

    1981-07-01

    A modified basin-type solar still (BTSS) has been developed. The new idea introduced is to re-use the latent heat due to condensation for increasing the temperature of saline water flowing into the device. A new term had been introduced in the balance of equation of conventional BTSS leading to the increase of the efficiency. According to the suggested model, a modified BTSS had been constructed and tested. It is found that the increase in the efficiency is about 14%. (author)

  17. Salt tectonics in Santos Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Quirk, David G.; Nielsen, Malene; Raven, Madeleine [Maersk Oil and Gas, Copenhagen (Denmark); Menezes, Paulo [Maersk Oil and Gas, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    From Albian to end Cretaceous times, the inboard part of the Santos Basin in Brazil was affected by extension as salt flowed basinwards under the effect of gravity. Salt rollers, flip-flop salt diapirs and the famous Albian Gap were all formed by this process. Outboard of these extensional structures, contraction was taken up in a wide zone of thickened salt where salt collected. The overburden was carried on top of the salt as it flowed down-dip, with up to 40 km of translation recorded in Albian strata. (author)

  18. Neotectonic and seismicidad in the Granada basin

    International Nuclear Information System (INIS)

    Sanz de Galdeano, C.; Vidal, F.; Miguel, F. de

    1984-01-01

    The depression of Granada is one of the Betics interior basins whose formation begun during the Middle Miocene and reached its individualization from the Upper Miocene. The main fracture directions are: N10-30E, N120-150E, N70-100E, some of them show great vertical jumpings. This seismic area is the most active in the Cordilleras Beticas (frequently like seismic series) and some destructive earthquakes occurred in the past. The higher seismic activity is concentrated in most subsident sectors of the area: the Vega de Granada, the Padul-Valle de Lecrin and the ''corredor de las Alpujarras'' prolongation about Arenas del Rey. (author)

  19. SEA of river basin management plans

    DEFF Research Database (Denmark)

    Larsen, Sanne Vammen; Kørnøv, Lone

    2009-01-01

    In, 2000 the European Parliament and the European Council passed the Water Framework Directive (WFD) to be implemented in all Member States. The consequence of the directive is that river basin management plans (RBMPs) shall be prepared which are legally subject to a strategic environmental...... assessment (SEA). An important environmental factor for the water sector is climate change, especially the changes it causes to the water environment. However, based on an argument of an inadequate knowledge base regarding climate change impacts, the prospect of Danish authorities including climate change...

  20. Ecohydrological Controls on Intra-Basin Alpine Subarctic Water Balances

    Science.gov (United States)

    Carey, S. K.; Ziegler, C. M.

    2007-12-01

    In the mountainous Canadian subarctic, elevation gradients control the disposition of vegetation, permafrost, and characteristics of the soil profile. How intra-basin ecosystems combine to control catchment-scale water and biogeochimcal cycling is uncertain. To this end, a multi-year ecohydrological investigation was undertaken in Granger Basin (GB), a 7.6 km2 sub-basin of the Wolf Creek Research Basin, Yukon Territory, Canada. GB was divided into four sub-basins based on the dominant vegetation and permafrost status, and the timing and magnitude of hydrological processes were compared using hydrometric and hydrochemical methods. Vegetation plays an important role in end-of-winter snow accumulation as snow redistribution by wind is controlled by roughness length. In sub-basins of GB with tall shrubs, snow accumulation is enhanced compared with areas of short shrubs and tundra vegetation. The timing of melt was staggered with elevation, although melt-rates were similar among the sub-basins. Runoff was enhanced at the expense of infiltration in tall shrub areas due to high snow water equivalent and antecedent soil moisture. In the high-elevation tundra sub-basin, thin soils with cold ground temperatures resulted in increased surface runoff. For the freshet period, the lower and upper sub-basins accounted for 81 % of runoff while accounting for 58 % of the total basin area. Two-component isotopic hydrograph separation revealed that during melt, pre-event water dominated in all sub-basins, yet those with greater permafrost disposition and taller shrubs had increased event-water. Dissolved organic carbon (DOC) spiked prior to peak freshet in each sub-basin except for the highest with thin soils, and was associated with flushing of surficial organic soils. For the post-melt period, all sub-basins have similar runoff contributions. Solute and stable isotope data indicate that in sub-basins dominated by permafrost, supra-permafrost runoff pathways predominate as flow

  1. Hot, deep origin of petroleum: deep basin evidence and application

    Science.gov (United States)

    Price, Leigh C.

    1978-01-01

    Use of the model of a hot deep origin of oil places rigid constraints on the migration and entrapment of crude oil. Specifically, oil originating from depth migrates vertically up faults and is emplaced in traps at shallower depths. Review of petroleum-producing basins worldwide shows oil occurrence in these basins conforms to the restraints of and therefore supports the hypothesis. Most of the world's oil is found in the very deepest sedimentary basins, and production over or adjacent to the deep basin is cut by or directly updip from faults dipping into the basin deep. Generally the greater the fault throw the greater the reserves. Fault-block highs next to deep sedimentary troughs are the best target areas by the present concept. Traps along major basin-forming faults are quite prospective. The structural style of a basin governs the distribution, types, and amounts of hydrocarbons expected and hence the exploration strategy. Production in delta depocenters (Niger) is in structures cut by or updip from major growth faults, and structures not associated with such faults are barren. Production in block fault basins is on horsts next to deep sedimentary troughs (Sirte, North Sea). In basins whose sediment thickness, structure and geologic history are known to a moderate degree, the main oil occurrences can be specifically predicted by analysis of fault systems and possible hydrocarbon migration routes. Use of the concept permits the identification of significant targets which have either been downgraded or ignored in the past, such as production in or just updip from thrust belts, stratigraphic traps over the deep basin associated with major faulting, production over the basin deep, and regional stratigraphic trapping updip from established production along major fault zones.

  2. Classification of Prairie basins by their hysteretic connected functions

    Science.gov (United States)

    Shook, K.; Pomeroy, J. W.

    2017-12-01

    Diagnosing climate change impacts in the post-glacial landscapes of the North American Prairies through hydrological modelling is made difficult by drainage basin physiography. The region is cold, dry and flat with poorly developed stream networks, and so the basin area that is hydrologically connected to the stream outlet varies with basin depressional storage. The connected area controls the contributing area for runoff reaching the stream outlet. As depressional storage fills, ponds spill from one to another; the chain of spilling ponds allows water to flow over the landscape and increases the connected area of the basin. As depressional storage decreases, the connected fraction drops dramatically. Detailed, fine-scale models and remote sensing have shown that the relationship between connected area and the depressional storage is hysteretic in Prairie basins and that the nature of hysteresis varies with basin physiography. This hysteresis needs to be represented in hydrological models to calculate contributing area, and therefore streamflow hydrographs. Parameterisations of the hysteresis are needed for large-scale models used for climate change diagnosis. However, use of parameterisations of hysteresis requires guidance on how to represent them for a particular basin. This study shows that it is possible to relate the shape of hysteretic functions as determined by detailed models to the overall physiography of the basin, such as the fraction of the basin below the outlet, and remote sensing estimates of depressional storage, using the size distribution and location of maximum ponded water areas. By classifying basin physiography, the hysteresis of connected area - storage relationships can be estimated for basins that do not have high-resolution topographic data, and without computationally-expensive high-resolution modelling.

  3. Characteristic mega-basin water storage behavior using GRACE.

    Science.gov (United States)

    Reager, J T; Famiglietti, James S

    2013-06-01

    [1] A long-standing challenge for hydrologists has been a lack of observational data on global-scale basin hydrological behavior. With observations from NASA's Gravity Recovery and Climate Experiment (GRACE) mission, hydrologists are now able to study terrestrial water storage for large river basins (>200,000 km 2 ), with monthly time resolution. Here we provide results of a time series model of basin-averaged GRACE terrestrial water storage anomaly and Global Precipitation Climatology Project precipitation for the world's largest basins. We address the short (10 year) length of the GRACE record by adopting a parametric spectral method to calculate frequency-domain transfer functions of storage response to precipitation forcing and then generalize these transfer functions based on large-scale basin characteristics, such as percent forest cover and basin temperature. Among the parameters tested, results show that temperature, soil water-holding capacity, and percent forest cover are important controls on relative storage variability, while basin area and mean terrain slope are less important. The derived empirical relationships were accurate (0.54 ≤  E f  ≤ 0.84) in modeling global-scale water storage anomaly time series for the study basins using only precipitation, average basin temperature, and two land-surface variables, offering the potential for synthesis of basin storage time series beyond the GRACE observational period. Such an approach could be applied toward gap filling between current and future GRACE missions and for predicting basin storage given predictions of future precipitation.

  4. Geochemical evolution of groundwater salinity at basin scale: a case study from Datong basin, Northern China.

    Science.gov (United States)

    Wu, Ya; Wang, Yanxin

    2014-05-01

    A hydrogeochemical investigation using integrated methods of stable isotopes ((18)O, (2)H), (87)Sr/(86)Sr ratios, Cl/Br ratios, chloride-mass balance, mass balance and hydrogeochemical modeling was conducted to interpret the geochemical evolution of groundwater salinity in Datong basin, northern China. The δ(2)H, δ(18)O ratios in precipitation exhibited a local meteoric water line of δ(2)H = 6.4 δ(18)O -5 (R(2) = 0.94), while those in groundwater suggested their meteoric origin in a historically colder climatic regime with a speculated recharge rate of less than 20.5 mm overall per year, in addition to recharge from a component of deep residual ancient lake water enriched with Br. According to the Sr isotope binary mixing model, the mixing of recharges from the Shentou karst springs (24%), the western margins (11%) and the eastern margins (65%) accounts for the groundwater from the deep aquifers of the down-gradient parts in the central basin is a possible mixing mechanism. In Datong, hydrolysis of silicate minerals is the most important hydrogeochemical process responsible for groundwater chemistry, in addition to dissolution of carbonate and evaporites. In the recharge areas, silicate chemical weathering is typically at the bisiallitization stage, while that in the central basin is mostly at the monosiallitization stage with limited evidence of being in equilibrium with gibbsite. Na exchange with bound Ca, Mg prevails at basin scale, and intensifies with groundwater salinity, while Ca, Mg exchange with bound Na locally occurs in the east pluvial and alluvial plains. Although groundwater salinity increases with the progress of water-rock/sediment interactions along the flow path, as a result of carbonate solubility control and continuous evapotranspiration, Na-HCO3 and Na-Cl-SO4 types of water are usually characterized respectively in the deep and the shallow aquifers of an inland basin with a silicate terrain in an arid climatic regime.

  5. Thermal evolution of a hyperextended rift basin, Mauléon Basin, western Pyrenees

    Science.gov (United States)

    Hart, Nicole R.; Stockli, Daniel F.; Lavier, Luc L.; Hayman, Nicholas W.

    2017-06-01

    Onshore and offshore geological and geophysical observations and numerical modeling have greatly improved the conceptual understanding of magma-poor rifted margins. However, critical questions remain concerning the thermal evolution of the prerift to synrift phases of thinning ending with the formation of hyperextended crust and mantle exhumation. In the western Pyrenees, the Mauléon Basin preserves the structural and stratigraphic record of Cretaceous extension, exhumation, and sedimentation of the proximal-to-distal margin development. Pyrenean shortening uplifted basement and overlying sedimentary basins without pervasive shortening or reheating, making the Mauléon Basin an ideal locality to study the temporal and thermal evolution of magma-poor hyperextended rift systems through coupling bedrock and detrital zircon (U-Th)/He thermochronometric data from transects characterizing different structural rifting domains. These new data indicate that the basin was heated during early rifting to >180°C with geothermal gradients of 80-100°C/km. The proximal margin recorded rift-related exhumation/cooling at circa 98 Ma, whereas the distal margin remained >180°C until the onset of Paleocene Pyrenean shortening. Lithospheric-scale numerical modeling shows that high geothermal gradients, >80°C/km, and synrift sediments >180°C, can be reached early in rift evolution via heat advection by lithospheric depth-dependent thinning and blanketing caused by the lower thermal conductivity of synrift sediments. Mauléon Basin thermochronometric data and numerical modeling illustrate that reheating of basement and synrift strata might play an important role and should be considered in the future development of conceptual and numerical models for hyperextended magma-poor continental rifted margins.

  6. Basin-wide water accounting using remote sensing data: the case of transboundary Indus Basin

    Science.gov (United States)

    Karimi, P.; Bastiaanssen, W. G. M.; Molden, D.; Cheema, M. J. M.

    2012-11-01

    The paper describes the application of a new Water Accounting Plus (WA+) framework to produce spatial information on water flows, sinks, uses, storages and assets, in the Indus Basin, South Asia. It demonstrates how satellite-derived estimates of land use, land cover, rainfall, evaporation (E), transpiration (T), interception (I) and biomass production can be used in the context of WA+. The results for one selected year showed that total annual water depletion in the basin (502 km3) plus outflows (21 km3) exceeded total precipitation (482 km3). The deficit in supply was augmented through abstractions beyond actual capacity, mainly from groundwater storage (30 km3). The "landscape ET" (depletion directly from rainfall) was 344 km3 (69% of total consumption). "Blue water" depletion ("utilized flow") was 158 km3 (31%). Agriculture was the biggest water consumer and accounted for 59% of the total depletion (297 km3), of which 85% (254 km3) was through irrigated agriculture and the remaining 15% (44 km3) through rainfed systems. While the estimated basin irrigation efficiency was 0.84, due to excessive evaporative losses in agricultural areas, half of all water consumption in the basin was non-beneficial. Average rainfed crop yields were 0.9 t ha-1 and 7.8 t ha-1 for two irrigated crop growing seasons combined. Water productivity was low due to a lack of proper agronomical practices and poor farm water management. The paper concludes that the opportunity for a food-secured and sustainable future for the Indus Basin lies in focusing on reducing soil evaporation. Results of future scenario analyses suggest that by implementing techniques to convert soil evaporation to crop transpiration will not only increase production but can also result in significant water savings that would ease the pressure on the fast declining storage.

  7. Identification of dynamic basins in boiling fluxes

    International Nuclear Information System (INIS)

    Juanico, L.E.

    1997-01-01

    A theoretical and experimental study of the dynamic behavior of a boiling channel is presented. In particular, the existence of different basins of attraction during instabilities was established. A fully analytical treatment of boiling channel dynamics were performed using a algebraic delay model. Subcritical and supercritical Hopf bifurcations could be identified and analyzed using perturbation methods. The derivation of a fully analytical criterion for Hopf bifurcation transcription was applied to determine the amplitude of the limit cycles and the maximum allowed perturbations necessary to break the system stability. A lumped parameters model which allows the representation of flow reversal is presented. The dynamic of very large amplitude oscillations, out of the Hopf bifurcation domain, was studied. The analysis revealed the existence of new dynamical basins of attraction, where the system may evolve to and return from with hysteresis. Finally, an experimental study was conducted, in a water loop at atmospheric pressure, designed to reproduce the operating conditions analyzed in the theory. Different dynamic phase previously predicted in the theory were found and their nonlinear characteristics were studied. In particular, subcritical and supercritical Hopf bifurcations and very large amplitude oscillations with flow reversal were identified. (author). 53 refs., figs

  8. Mixed basin boundary structures of chaotic systems

    International Nuclear Information System (INIS)

    Rosa, E. Jr.; Ott, E.

    1999-01-01

    Motivated by recent numerical observations on a four-dimensional continuous-time dynamical system, we consider different types of basin boundary structures for chaotic systems. These general structures are essentially mixtures of the previously known types of basin boundaries where the character of the boundary assumes features of the previously known boundary types at different points arbitrarily finely interspersed in the boundary. For example, we discuss situations where an everywhere continuous boundary that is otherwise smooth and differentiable at almost every point has an embedded uncountable, zero Lebesgue measure set of points at which the boundary curve is nondifferentiable. Although the nondifferentiable set is only of zero Lebesgue measure, the curve close-quote s fractal dimension may (depending on parameters) still be greater than one. In addition, we discuss bifurcations from such a mixed boundary to a 'pure' boundary that is a fractal nowhere differentiable curve or surface and to a pure nonfractal boundary that is everywhere smooth. copyright 1999 The American Physical Society

  9. Optimizing development projects in mature basins

    Energy Technology Data Exchange (ETDEWEB)

    Swan, P.J. [BP Exploration, Aberdeen (United Kingdom)

    1995-08-01

    BP Exploration wishes to grow its gas business substantially and the Southern North Sea area expects to be a significant contributor to this growth. The Southern North Sea gas basin is characterised by a relatively large number of small prospects and discoveries lying within the catchment areas of existing pipeline systems serving larger fields currently in production. This growth will be achieved through expansion of production from existing large mature fields and new satellite developments, connected to existing pipeline systems. Significant modification to existing infrastructure will be required to bring the new production on stream. The low materiality of many of these new developments means that, based on current cost paradigms, they are sub-economic or do not offer returns commensurate with the risk. Also, implementation based on classical approaches tends to be resource-intensive in terms of key skills. Critical areas of concern in delivering growth objectives therefore relate to management of cost, implementation time and productivity of key human resources. The general approach adopted in pursuit of high performance includes a number of features: Innovative approaches to the service industries; simplification of equipment; streamlining of methodologies; application of novel technology; alignment of motivation of all contributors to overall objectives; and shifting the paradigm of risk. BP believes that this approach is a major breakthrough in extending and expanding the life of its assets in the Southern North Sea and is representative of the trend of optimization in the extended life of the Basin in general.

  10. 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.

  11. Geophysical investigation of the Raton Basin

    Science.gov (United States)

    Cheney, R. S.

    1982-05-01

    This thesis correlates gravity, magnetic, and seismic data for the Raton Basin of Colorado and New Mexico. The gravity data suggest that the study area, and the region around it, is in isostatic equilibrium. The free air anomaly in the southern portion of the study area suggests lack of local compensation due to Quaternary volocanic rock. The volcanic rock thickness, calculated from the free air gravity data, is 180 m. The gravity data indicated a crustal thickness of about 45 km, and the crust thinned from west to east. A basement relief map was constructed from the Bouquer gravity data. Computer techniques were developed to calculate the depth to the basement surface and to plot a contour map of that surface. The Raton Basin magnetic map defined the same surface found on the basement relief map since the overlying sedimentary rocks have no magnetism; therefore, any magnetism present is caused by the basement rock. A seismic survey near capulin Mountain detected a high level of microseismicity that may be caused by adjustment along faults or dormant volcanic activity.

  12. FLOOD SUSCEPTIBILITY ASSESSMENT IN THE NIRAJ BASIN

    Directory of Open Access Journals (Sweden)

    SANDA ROŞCA

    2012-03-01

    Full Text Available Flood susceptibility assessment in the Niraj basin. In the context of global warming and the increasing frequency of extreme weather events, it becomes evident that we have to face natural hazards, such as floods. In the area of Niraj basin this phenomenon is specific both in the spring, because of the snow melting and of the precipitations which come along with the season, and then in the summer because of the torrential precipitations but rarely in autumn and winter. The aim of this paper is to determinate the susceptibility of the zone and obtain a map which will take into consideration the possibility of a flooding. Defining vulnerability can help us understand this type of natural disasters and find the best ways to reduce it. For this purpose we use thematic layers, morphological characteristics (slope and depth fragmentation, hydrological characteristics, geology, pedology (permeability and soil texture, landuse, precipitation data, and human interventions because in this way we have the possibility to use data mining for this purpose. Data mining will allow us to extract new information based on the existing sets of data.The final result will be a thematic map that highlights the areas which are exposed to the flood. Therefore, this map can be used as a support decision for local government or business purposes.

  13. Forest Elephant Crisis in the Congo Basin

    Science.gov (United States)

    Blake, Stephen; Strindberg, Samantha; Boudjan, Patrick; Makombo, Calixte; Bila-Isia, Inogwabini; Ilambu, Omari; Grossmann, Falk; Bene-Bene, Lambert; de Semboli, Bruno; Mbenzo, Valentin; S'hwa, Dino; Bayogo, Rosine; Williamson, Liz; Fay, Mike; Hart, John; Maisels, Fiona

    2007-01-01

    Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Resolving this controversy requires accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct species, in the vast Congo Basin is unclear. We assessed population status and incidence of poaching from line-transect and reconnaissance surveys conducted on foot in sites throughout the Congo Basin. Results indicate that the abundance and range of forest elephants are threatened from poaching that is most intense close to roads. The probability of elephant presence increased with distance to roads, whereas that of human signs declined. At all distances from roads, the probability of elephant occurrence was always higher inside, compared to outside, protected areas, whereas that of humans was always lower. Inside protected areas, forest elephant density was correlated with the size of remote forest core, but not with size of protected area. Forest elephants must be prioritised in elephant management planning at the continental scale. PMID:17407383

  14. Exploratory shaft conceptual design report: Permian Basin

    International Nuclear Information System (INIS)

    1983-07-01

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Permian Basin locatd in the western part of Texas. Conceptualized designs for other possible locations (Paradox Basin in Utah and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

  15. Exploratory shaft conceptual design report: Paradox Basin

    International Nuclear Information System (INIS)

    1983-07-01

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Paradox Basin located in the southeastern part of Utah. Conceptualized designs for other possible locations (Permian Basin in Texas and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

  16. Depth anomalies in the Arabian Basin, NW Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Ajay, K.K.; Chaubey, A.K.

    that the excess subsidence of basement of the western part of the basin is probably caused by a relatively cold mantle, compared to the nearby eastern part of the basin which is affected by the intense thermal field of the former Reunion hotspot. Here, the rise...

  17. A Case Study of the Densu Basin, Ghana

    African Journals Online (AJOL)

    komla

    and middle sections of the basin are covered with semi-deciduous forest with a lush growth of thick and tall trees. ... and scrub forest vegetation with only few isolated trees. There are ... which underlie the south-eastern part of the basin and the area south of Weija to the estuary. The rocks of ...... Association, Washington, D.C.

  18. 13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    significance of these landscape parameters was ... reported that the geomorphic characteristics of a drainage basins play ... form and process of drainage basins that may ... tropical rain forest of Nigeria occupying an area of .... morphometric parameters such as relief, shape ... on floodplains can be pulled down while areas.

  19. Concentration of Trace Metals in Boreholes in the Ankobra Basin ...

    African Journals Online (AJOL)

    Fiifi Baidoo

    Most of the boreholes with high trace metal concentrations were located in and around the Bawdie-Bogoso-Prestea area. Introduction. Ankobra basin is one of the main mining areas in Ghana. The major minerals mined in this area include gold, manganese, bauxite and diamond. Gold mining in this basin dates about 500 ...

  20. 75 FR 38833 - Walker River Basin Acquisition Program

    Science.gov (United States)

    2010-07-06

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Walker River Basin Acquisition Program AGENCY... (Reclamation) is canceling work on the Environmental Impact Statement (EIS) for the Walker River Basin... Walker River, primarily for irrigated agriculture, have resulted in a steadily declining surface...

  1. Palaeoseismicity in relation to basin tectonics as revealed from soft ...

    Indian Academy of Sciences (India)

    belts acted as zones of rift propagation, and reac- tivation of palaeo-sutures and ... to Jurassic-aged riftogenic continental basins filled ... led to a half-graben geometry with accumulation of greater ... basin margin are thought to have been active dur- ...... Petrol. 22. 83–96. Kundu A and Goswami B 2008 A note on seismic evi-.

  2. Basement configuration of KG offshore basin from magnetic anomalies

    Indian Academy of Sciences (India)

    of charnockites of neighbouring EGMB and onshore K–G basin areas indicates that EGMB geology. (charnockites ... Marine magnetic anomalies; offshore K–G basin; magnetic basement; extension of EGMB geology; continent– oceanic boundary. ..... of India; J. Australian Petroleum Exploration Association. 14 29–41.

  3. Hydrocarbon resource potential of the Bornu basin northeastern ...

    African Journals Online (AJOL)

    Global Journal of Geological Sciences ... In the Bornu Basin which belongs to the West African Rift Subsystem (WARS) two potential petroleum systems are suggested. “Lower ... “Upper Cretaceous Petroleum System” – is the phase II rift sediments in the Bornu Basin which comprise mainly shallow marine to paralic shales,

  4. On the origin of the southern Permian Basin, Central Europe.

    NARCIS (Netherlands)

    van Wees, J.D.A.M.; Stephenson, R.A.; Ziegler, P.A.; Bayer, U.; McCann, T.; Dadlez, R.; Gaupp, R.; Narkiewicz, M.; Bitzer, F.; Scheck, M.

    2000-01-01

    A detailed study of the structural and stratigraphic evolution of the Southern Permian Basin during latest Carboniferous to Early Jurassic times, supported by quantitative subsidence analyses and forward basin modelling for 25 wells, leads us to modify the conventional model for the

  5. Morphometric analyses of the river basins in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Wagle, B.G.

    Morphometric analyses of seven river basins in Goa, India have been carried out. The linear and areal aspects of these basins are reported here. The plots of stream order versus stream numbers and stream orders versus mean stream lengths are found...

  6. Predicting the ungauged basin : Model validation and realism assessment

    NARCIS (Netherlands)

    Van Emmerik, T.H.M.; Mulder, G.; Eilander, D.; Piet, M.; Savenije, H.H.G.

    2015-01-01

    The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of

  7. Examination of sludge from the Hanford K Basins fuel canisters

    International Nuclear Information System (INIS)

    Makenas, B.J.

    1998-01-01

    Samples of sludges with a high uranium content have been retrieved from the fuel canisters in the Hanford K West and K East basins. The composition of these samples contrasts markedly with the previously reported content of sludge samples taken from the K East basin floor. Chemical composition, chemical reactivity, and particle size of sludge are summarized in this paper

  8. Geologic structure of the eastern mare basins. [lunar basalts

    Science.gov (United States)

    Dehon, R. A.; Waskom, J. D.

    1976-01-01

    The thickness of mare basalts in the eastern maria are estimated and isopachs of the basalts are constructed. Sub-basalt basin floor topography is determined, and correlations of topographic variations of the surface with variations in basalt thickness or basin floor topography are investigated.

  9. Probing the basins of attraction of a recurrent neural network

    NARCIS (Netherlands)

    Heerema, M.; van Leeuwen, W.A.

    2000-01-01

    Analytical expressions for the weights $w_{ij}(b)$ of the connections of a recurrent neural network are found by taking explicitly into account basins of attraction, the size of which is characterized by a basin parameter $b$. It is shown that a network with $b \

  10. Palaeomagnetism of neoproterozoic formations in the volta basin ...

    African Journals Online (AJOL)

    The Volta basin lies on the southern part of the West African craton, more precisely on the Leo (or Man) craton. The Dahomeyides chain is thrust onto its eastern fringe. The Volta basin is filled with Neoproterozoic to Cambro- Ordovician sediments. From bottom to top they are: the Boumbouaka Supergroup made of ...

  11. Geology and assessment of unconventional resources of Phitsanulok Basin, Thailand

    Science.gov (United States)

    ,

    2014-01-01

    The U.S. Geological Survey (USGS) quantitatively assessed the potential for unconventional oil and gas resources within the Phitsanulok Basin of Thailand. Unconventional resources for the USGS include shale gas, shale oil, tight gas, tight oil, and coalbed gas. In the Phitsanulok Basin, only potential shale-oil and shale-gas resources were quantitatively assessed.

  12. Spectral Depth Analysis of some Segments of the Bida Basin ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-16

    Dec 16, 2017 ... ABSTRACT: Spectral depth analysis was carried out on ten (10) of the 2009 total magnetic field intensity data sheets covering some segments of the Bida basin, to determine the depth to magnetic basement within the basin. The data was ... groundwater lie concealed beneath the earth surface and the ...

  13. Basin of Mexico: A history of watershed mismanagement

    Science.gov (United States)

    Luis A. Bojorquez Tapia; Exequiel Ezcurra; Marisa Mazari-Hiriart; Salomon Diaz; Paola Gomez; Georgina Alcantar; Daniela Megarejo

    2000-01-01

    Mexico City Metropolitan Zone (MCMZ) is located within the Basin of Mexico. Because of its large population and demand for natural resources, several authors have questioned the viability of the city, especially in terms of water resources. These are reviewed at the regional and the local scales. It is concluded that a multi-basin management approach is necessary to...

  14. Chapter 48: Geology and petroleum potential of the Eurasia Basin

    Science.gov (United States)

    Moore, Thomas E.; Pitman, Janet K.

    2011-01-01

    The Eurasia Basin petroleum province comprises the younger, eastern half of the Arctic Ocean, including the Cenozoic Eurasia Basin and the outboard part of the continental margin of northern Europe. For the USGS petroleum assessment (CARA), it was divided into four assessment units (AUs): the Lena Prodelta AU, consisting of the deep-marine part of the Lena Delta; the Nansen Basin Margin AU, comprising the passive margin sequence of the Eurasian plate; and the Amundsen Basin and Nansen Basin AUs which encompass the abyssal plains north and south of the Gakkel Ridge spreading centre, respectively. The primary petroleum system thought to be present is sourced in c. 50–44 Ma (Early to Middle Eocene) condensed pelagic deposits that could be widespread in the province. Mean estimates of undiscovered, technically recoverable petroleum resources include <1 billion barrels of oil (BBO) and about 1.4 trillion cubic feet (TCF) of nonassociated gas in Lena Prodelta AU, and <0.4 BBO and 3.4 TCF nonassociated gas in the Nansen Basin Margin AU. The Nansen Basin and Amundsen Basin AUs were not quantitatively assessed because they have less than 10% probability of containing at least one accumulation of 50 MMBOE (million barrels of oil equivalent).

  15. Analysis of Ignition Testing on K-West Basin Fuel

    Energy Technology Data Exchange (ETDEWEB)

    J. Abrefah; F.H. Huang; W.M. Gerry; W.J. Gray; S.C. Marschman; T.A. Thornton

    1999-08-10

    Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).

  16. Analysis of Ignition Testing on K-West Basin Fuel

    International Nuclear Information System (INIS)

    Abrefah, J.; Huang, F.H.; Gerry, W.M.; Gray, W.J.; Marschman, S.C.; Thornton, T.A.

    1999-01-01

    Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994)

  17. Morphometric analysis of Suketi river basin, Himachal Himalaya, India

    Indian Academy of Sciences (India)

    The entire Suketi river basin has been divided into five sub-basins based on the catchment areas of ..... with equilibrium profile, where driving force is equivalent to the .... need attention for revival and sustenance by taking suitable artificial ...

  18. Highly calcareous lacustrine soils in the Great Konya Basin, Turkey

    NARCIS (Netherlands)

    Meester, de T.

    1971-01-01

    The Great Konya Basin is in the south of the Central Anatolian Plateau in Turkey. It is a depression without outlet to the sea. The central part of the Basin is the floor of a former Pleistocene lake, the Ancient Konya Lake. This area, called the Lacustrine
    Plain, has highly calcareous

  19. Regionalization for uncertainty reduction in flows in ungauged basins

    NARCIS (Netherlands)

    Booij, Martijn J.; Deckers, Dave L.E.H.; Rientjes, Tom H.M.; Krol, Martinus S.; Boegh, Eva; Kunstmann, Harald; Wagener, Thorsten; Hall, Alan; Bastidas, Luis; Franks, Stewart; Gupta, Hoshin; Rosbjerg, Dan; Schaake, John

    2007-01-01

    The objective of this study is to contribute to the reduction of predictive uncertainty in flows in ungauged basins through application of a regionalization method to 56 well-gauged basins in the United Kingdom. The classical approach of regionalization is adopted, where regression relationships

  20. 48 CFR 25.405 - Caribbean Basin Trade Initiative.

    Science.gov (United States)

    2010-10-01

    ... Initiative. 25.405 Section 25.405 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Trade Agreements 25.405 Caribbean Basin Trade Initiative. Under the Caribbean Basin Trade Initiative, the United States Trade Representative has determined that, for...

  1. Predicting the ungauged basin: model validation and realism assessment

    NARCIS (Netherlands)

    van Emmerik, Tim; Mulder, Gert; Eilander, Dirk; Piet, Marijn; Savenije, Hubert

    2015-01-01

    The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of

  2. Evolution of the Pannonian basin and its geothermal resources

    NARCIS (Netherlands)

    Horváth, F.; Musitz, B.; Balázs, A.; Végh, A.; Uhrin, A.; Nádor, A.; Koroknai, B.; Pap, N.; Tóth, T.; Wórum, G.

    The Pannonian basin is an integral part of the convergence zone between the Eurasian and Nubian plates characterized by active subductions of oceanic and continental plates, and formation of backarc basins. The first part of this paper presents an overview of the evolution of the

  3. Earthworms (Annelida: Oligochaeta) of the Columbia River basin assessment area.

    Science.gov (United States)

    Sam. James

    2000-01-01

    Earthworms are key components of many terrestrial ecosystems; however, little is known of their ecology, distribution, and taxonomy in the eastern interior Columbia River basin assessment area (hereafter referred to as the basin assessment area). This report summarizes the main issues about the ecology of earthworms and their impact on the physical and chemical status...

  4. Grande Ronde Basin Fish Habitat Enhancement Project : 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    McGowan, Vance R.; Powell, Russ M.

    1999-05-01

    The primary goal of ''The Grande Ronde Basin Fish Habitat Improvement Project'' is to access, create, improve, protect, and restore reparian and instream habitat for anadromous salmonids, thereby maximizing opportunities for natural fish production within the basin.

  5. National emission standards for hazardous air pollutants application for approval to stabilize the 105N Basin

    International Nuclear Information System (INIS)

    1994-01-01

    The 105N Basin (basin) Stabilization will place the basin in a radiologically and environmentally safe condition so that it can be decommissioned at a later date. The basin stabilization objectives are to inspect for Special Nuclear Material (SNM) (i.e., fuel assemblies and fuel pieces), remove the water from the basin and associated pits, and stabilize the basin surface. The stabilization will involve removal of basin hardware, removal of basin sediments, draining of basin water, and cleaning and stabilizing basin surfaces-to prevent resuspension of radioactive emissions to the air. These activities will be conducted in accordance with all applicable regulations. The basin is in the 105N Building, which is located in the 100N Area. The 100N Area is located in the Northern portion of the Hanford Site approximately 35 miles northwest of the city of Richland, Washington. The basin is a reinforced unlined concrete structure 150 feet long, 50 feet wide, and 24 feet deep. The basin is segregated into seven areas sharing a common pool of water; the Discharge/Viewing (''D'') Pit, the fuel segregation pit (including a water tunnel that connects the ''D'' pit and segregation pit), two storage basins designated as North Basin and South Basin, two cask load-out pits, and a fuel examination area. The North Basin floor is entirely covered and the South Basin is partly covered by a modular array of cubicles formed by boron concrete posts and boron concrete panels

  6. Pacific Basin Heavy Oil Refining Capacity

    Directory of Open Access Journals (Sweden)

    David Hackett

    2013-02-01

    Full Text Available The United States today is Canada’s largest customer for oil and refined oil products. However, this relationship may be strained due to physical, economic and political influences. Pipeline capacity is approaching its limits; Canadian oil is selling at substantive discounts to world market prices; and U.S. demand for crude oil and finished products (such as gasoline, has begun to flatten significantly relative to historical rates. Lower demand, combined with increased shale oil production, means U.S. demand for Canadian oil is expected to continue to decline. Under these circumstances, gaining access to new markets such as those in the Asia-Pacific region is becoming more and more important for the Canadian economy. However, expanding pipeline capacity to the Pacific via the proposed Northern Gateway pipeline and the planned Trans Mountain pipeline expansion is only feasible when there is sufficient demand and processing capacity to support Canadian crude blends. Canadian heavy oil requires more refining and produces less valuable end products than other lighter and sweeter blends. Canadian producers must compete with lighter, sweeter oils from the Middle East, and elsewhere, for a place in the Pacific Basin refineries built to handle heavy crude blends. Canadian oil sands producers are currently expanding production capacity. Once complete, the Northern Gateway pipeline and the Trans Mountain expansion are expected to deliver an additional 500,000 to 1.1 million barrels a day to tankers on the Pacific coast. Through this survey of the capacity of Pacific Basin refineries, including existing and proposed facilities, we have concluded that there is sufficient technical capacity in the Pacific Basin to refine the additional Canadian volume; however, there may be some modifications required to certain refineries to allow them to process Western Canadian crude. Any additional capacity for Canadian oil would require refinery modifications or

  7. Climatic controls on arid continental basin margin systems

    Science.gov (United States)

    Gough, Amy; Clarke, Stuart; Richards, Philip; Milodowski, Antoni

    2016-04-01

    Alluvial fans are both dominant and long-lived within continental basin margin systems. As a result, they commonly interact with a variety of depositional systems that exist at different times in the distal extent of the basin as the basin evolves. The deposits of the distal basin often cycle between those with the potential to act as good aquifers and those with the potential to act as good aquitards. The interactions between the distal deposits and the basin margin fans can have a significant impact upon basin-scale fluid flow. The fans themselves are commonly considered as relatively homogeneous, but their sedimentology is controlled by a variety of factors, including: 1) differing depositional mechanisms; 2) localised autocyclic controls; 3) geometrical and temporal interactions with deposits of the basin centre; and, 4) long-term allocyclic climatic variations. This work examines the basin margin systems of the Cutler Group sediments of the Paradox Basin, western U.S.A and presents generalised facies models for the Cutler Group alluvial fans as well as for the zone of interaction between these fans and the contemporaneous environments in the basin centre, at a variety of scales. Small-scale controls on deposition include climate, tectonics, base level and sediment supply. It has been ascertained that long-term climatic alterations were the main control on these depositional systems. Models have been constructed to highlight how both long-term and short-term alterations in the climatic regime can affect the sedimentation in the basin. These models can be applied to better understand similar, but poorly exposed, alluvial fan deposits. The alluvial fans of the Brockram Facies, northern England form part of a once-proposed site for low-level nuclear waste decommissioning. As such, it is important to understand the sedimentology, three-dimensional geometry, and the proposed connectivity of the deposits from the perspective of basin-scale fluid flow. The developed

  8. Cenozoic North American Drainage Basin Evolution, Sediment Yield, and Accumulation in the Gulf of Mexico Basin

    Science.gov (United States)

    Galloway, W.; Ganey-Curry, P. E.

    2010-12-01

    The Cenozoic fill of the Gulf of Mexico basin contains a continuous record of sediment supply from the North American continental interior for the past 65 million years. Regional mapping of unit thickness and paleogeography for 18 depositional episodes defines patterns of shifting entry points of continental fluvial systems and quantifies the total volume of sediment supplied during each episode. Eight fluvio-deltaic depocenters, named for geographic similarities to entry points and drainage basins of modern rivers, are present. From southwest to northeast, they are the Rio Bravo, Rio Grande, Guadalupe, Colorado, Houston-Brazos, Red, Mississippi, and Tennessee axes. Sediment volume was calculated from hand-contoured unit thickness maps compiled from basin-wide well and seismic control. Using a GIS algorithm to sum volumes within polygons bounding interpreted North American river contribution, the total extant volume was then calculated. General compaction factors were used to convert modern volume to quantitative approximations of total grain volume. Grain volume rate of supply for each depositional episode was then calculated. Values vary by more than an order of magnitude. Supply rate has commonly varied by two-fold or more between successive depositional episodes. Sediment supply is a significant, independent variable in development of stratigraphic sequences within the Gulf basin. Paleogeographic maps of the continental interior for eleven Cenozoic time intervals display the evolving and complex interplay of intracontinental tectonism, climate change, and drainage basin evolution. Five tectono-climatic eras are differentiated: Paleocene late Laramide era; early to middle Eocene terminal Laramide era; middle Cenozoic (Late Eocene—Early Miocene) dry, volcanogenic era; middle Neogene (Middle—Late Miocene) arid, extensional era; and late Neogene (Plio—Pleistocene) monsoonal, epeirogenic uplift era. Sediment supply to the GOM reflects the interplay of (1

  9. Congo Basin rainfall climatology: can we believe the climate models?

    Science.gov (United States)

    Washington, Richard; James, Rachel; Pearce, Helen; Pokam, Wilfried M; Moufouma-Okia, Wilfran

    2013-01-01

    The Congo Basin is one of three key convective regions on the planet which, during the transition seasons, dominates global tropical rainfall. There is little agreement as to the distribution and quantity of rainfall across the basin with datasets differing by an order of magnitude in some seasons. The location of maximum rainfall is in the far eastern sector of the basin in some datasets but the far western edge of the basin in others during March to May. There is no consistent pattern to this rainfall distribution in satellite or model datasets. Resolving these differences is difficult without ground-based data. Moisture flux nevertheless emerges as a useful variable with which to study these differences. Climate models with weak (strong) or even divergent moisture flux over the basin are dry (wet). The paper suggests an approach, via a targeted field campaign, for generating useful climate information with which to confront rainfall products and climate models.

  10. Northern part, Ten Mile and Taunton River basins

    Science.gov (United States)

    Williams, John R.; Willey, Richard E.

    1967-01-01

    The northern part of the Ten Mile and Taunton River basins is an area of about 195 square miles within Norfolk, Plymouth, and Bristol Counties in southeastern Massachusetts. The northern boundary of the area (plate 1) is the drainage divide separating these basins from that of the Charles, Neponset, and Weymouth River basins. The western boundary is, for the most part, the divide separating the basins from the Blackstone River basin. The eastern boundary is at the edge of the Brockton-Pembroke area (Petersen, 1962; Petersen and Shaw, 1961). The southern boundary in Seekonk is the northern limit of the East Providence quadrangle, for which a ground-water map was prepared by Allen and Gorman (1959); eastward, the southern boundaries of the city of Attleboro and the towns of Norton, Easton, and West Bridgewater form the southern boundary of the area.

  11. Faunal migration into the Late Permian Zechstein Basin

    DEFF Research Database (Denmark)

    Sørensen, Anne Mehlin; Håkansson, Eckart; Stemmerik, Lars

    2007-01-01

    Late Permian bryozoans from the Wegener Halvø, Ravnefjeld and Schuchert Formations in East Greenland have been investigated. 14 genera are recognised.      Integration of the new bryozoan data from the Upper Permian of East Greenland with data on the distribution of Permian bryozoans along...... the northern margin of Pangea is used to test hypotheses concerning Late Palaeozoic evolution of the North Atlantic region. During the Permian, the Atlantic rift system formed a seaway between Norway and Greenland from the boreal Barents Shelf to the warm and arid Zechstein Basin. This seaway is considered...... to be the only marine connection to the Zechstein Basin and therefore the only possible migration route for bryozoans to enter the basin. The distribution of Permian bryozoans is largely in keeping with such a connection from the cool Barents Shelf past the East Greenland Basin to the warm Zechstein Basin...

  12. Petroleum geology framework, southeast Bowser Basin, British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Haggart, J.W. [Geological Survey of Canada, Vancouver, BC (Canada); Mahoney, J.B. [Wisconsin Univ., Eau Claire, WS (United States). Dept. of Geology

    2003-07-01

    There are significant coal resources in the northern regions of the Bowser basin in north-central British Columbia. However, the resource potential of the southern part of the basin has not been assessed, therefore the hydrocarbon potential is not known. Geological maps indicate several Mesozoic clastic and volcanic units across the southern part of the basin. Two stratigraphic intervals of the southern Bowser basin are considered to be potential source rocks within the Jurassic-Cretaceous strata. The fine-grained clastic rocks of the Bowser Lake Group contain significant amounts of carbonaceous material or organic matter. Well developed cleavage indicates that the rocks may be thermally over mature. This paper described potential reservoir rocks within the basin, along with their thermal maturation and conceptual play. 4 figs.

  13. Uranium prospecting in the Iguatu and Frade basins (Brazil)

    International Nuclear Information System (INIS)

    Lemos, J.C.

    The Mineral Exploration Department of CNEN studied the possibilities of uranium occurences in the Iguatu and Frade Basins in the preliminary research program designated 'Small Basins of the Northeast' which contitutes the object of this report. The two basins are located in the State of Ceara. The results of geologic and radiometric researches ahowed that the possibilities for uranium mineralizations were small, since the analyses of samples from the two main anomalies showed the radioactivity came from the remains of monazite. Further analysis of sedimentologic factors indicated favorable confitions for uranium concentration, taking into consideration the large variations of vertical and lateral granulometries, which permit spectulation about the flow of uraniferous solutions. radiometric measurements of surface samples were insignificant and no uranium mineral was found. The result of research of the sedimentary Frade Basin was negative for uranium mineralization. The basin was entirely eroded, remaining as an outcrop described in this report. (F.E.) [pt

  14. Geology and salt deposits of the Michigan Basin

    International Nuclear Information System (INIS)

    Johnson, K.S.; Gonzales, S.

    1976-07-01

    The Silurian-age Salina salt, one of the greatest deposits of bedded rock salt in the world, underlies most of the Michigan basin and parts of the Appalachian basin in Ohio. Pennsylvania, New York, and West Virginia. Interest in this salt deposit has increased in recent years because there may be one or more areas where it could be used safely as a repository for the underground storage of high-level radioactive wastes. The general geology of the Michigan basin is summarized and the major salt deposits are described in the hope that these data will be useful in determining whether there are any areas in the basin that are sufficiently promising to warrant further detailed study. Distribution of the important salt deposits in the basin is limited to the Southern Peninsula of Michigan

  15. Magmatism and petroleum exploration in the Brazilian Paleozoic basins

    Energy Technology Data Exchange (ETDEWEB)

    Thomaz Filho, Antonio; Antonioli, Luzia [Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Rua Sao Francisco Xavier, no 524/2030, CEP 20550-900, Rio de Janeiro, RJ (Brazil); Mizusaki, Ana Maria Pimentel [Universidade Federal do Rio Grande do Sul, Instituto de Geociencias, Avenida Bento Goncalves, no 9500, Campus do Vale, CEP 91509-900, Porto Alegre, RS (Brazil)

    2008-02-15

    Petroleum exploration in the Paleozoic sedimentary basins of Brazil has proven very challenging for explorationists. Except for the Solimoes Basin, in which transcurrent tectonism formed prospective structural highs, Brazilian Paleozoic basins lack intense structural deformation, and hence the detection and prospecting of place is often difficult. Magmatic intrusive and associated rocks in all these basins have traditionally been considered heat sources and hydrocarbon traps. The role of tholeiitic basic dikes in the generation, migration and accumulation of petroleum in the Anhembi oil occurrence (Sao Paulo State) is discussed herein. It follows that similar geological settings in other Paleozoic basins can be regarded as promising sites for oil accumulation that warrant investigation via modern geological and geophysical methods. (author)

  16. Did the Bering Sea Form as a Cenozoic Backarc Basin?

    Science.gov (United States)

    Stern, R. J.; Barth, G. A.; Scheirer, D. S.; Scholl, D. W.

    2012-12-01

    Understanding the origins of Bering Sea marginal basins (Aleutian, Bowers, and Komandorsky basins; AB, BB, KB) is key for reconstructing N. Pacific tectonic and magmatic evolution. New acquisitions and recompilations of MCS, OBS, and potential field data (Barth et al. poster. this session) for USGS Extended Continental Shelf project and selection of Aleutians as GeoPrisms Subduction Cycles and Deformation focus site stimulate reconsideration of BB, KB, and especially AB origins. AB has long been regarded as N. Pacific crust trapped when the Aleutian subduction began ~45-50 Ma. BB and KB probably formed together as Miocene backarc basins. Presence of Oligo-Miocene arc volcanics on Bowers and Shirshov ridges suggests that these are remnant arcs, orphaned by AB and KB opening. Seven lines of evidence suggest that AB formed as a Paleogene backarc basin: 1) AB heatflow suggests an age of about 44 Ma (Langseth et al 1980 JGR). 2) Formation of NNW-trending rift basins on Bering shelf (Navarin, Pribilof, and St. George basins) in Paleogene time indicate extension at this time. 3) The early Paleogene "red unconformity" of the Beringian margin could indicate uplift, erosion, and subsidence associated with AB opening. 4) ~N-S magnetic anomalies in AB contrasts with E-W Kula anomalies on N. Pacific, indicating that the two tracts of oceanic crust formed at different spreading ridges. 5) Thicker sediment in AB (2-4 km) vs. BB and KB (oceanic crust.ectonic scenario for formation of Aleutian Arc and Bering Sea basins. Green = present land; yellow = shelf; AB = Aleutian Basin; KB = Komandorsky Basin; BB = Bowers Basin; SR = Shirshov Ridge, BR = Bowers Ridge; Red = active volcanism and spreading ; Blue = extinct volcanism and spreading

  17. Corrosion of aluminum alloys in a reactor disassembly basin

    International Nuclear Information System (INIS)

    Howell, J.P.; Zapp, P.E.; Nelson, D.Z.

    1992-01-01

    This document discusses storage of aluminum clad fuel and target tubes of the Mark 22 assembly takes place in the concrete-lined, light-water-filled, disassembly basins located within each reactor area at the Savannah River Site (SRS). A corrosion test program has been conducted in the K-Reactor disassembly basin to assess the storage performance of the assemblies and other aluminum clad components in the current basin environment. Aluminum clad alloys cut from the ends of actual fuel and target tubes were originally placed in the disassembly water basin in December 1991. After time intervals varying from 45--182 days, the components were removed from the basin, photographed, and evaluated metallographically for corrosion performance. Results indicated that pitting of the 8001 aluminum fuel clad alloy exceeded the 30-mil (0.076 cm) cladding thickness within the 45-day exposure period. Pitting of the 1100 aluminum target clad alloy exceeded the 30-mil (0.076 cm) clad thickness in 107--182 days exposure. The existing basin water chemistry is within limits established during early site operations. Impurities such as Cl - , NO 3 - and SO 4 - are controlled to the parts per million level and basin water conductivity is currently 170--190 μmho/cm. The test program has demonstrated that the basin water is aggressive to the aluminum components at these levels. Other storage basins at SRS and around the US have successfully stored aluminum components for greater than ten years without pitting corrosion. These basins have impurity levels controlled to the parts per billion level (1000X lower) and conductivity less than 1.0 μmho/cm

  18. Assessment of undiscovered oil and gas resources in the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas, 2017

    Science.gov (United States)

    Marra, Kristen R.; Gaswirth, Stephanie B.; Schenk, Christopher J.; Leathers-Miller, Heidi M.; Klett, Timothy R.; Mercier, Tracey J.; Le, Phuong A.; Tennyson, Marilyn E.; Finn, Thomas M.; Hawkins, Sarah J.; Brownfield, Michael E.

    2017-05-15

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean resources of 4.2 billion barrels of oil and 3.1 trillion cubic feet of gas in the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas.

  19. 78 FR 65609 - Medicine Bow-Routt National Forests and Thunder Basin National Grassland; Wyoming; Thunder Basin...

    Science.gov (United States)

    2013-11-01

    ... National Grassland; Wyoming; Thunder Basin National Grassland Prairie Dog Amendment Environmental Impact... Cooperating Agencies. No changes to the Proposed Action or Purpose of and Need for Action have been made... alternatives will be analyzed in the Thunder Basin National Grassland Prairie Dog Amendment EIS. The EIS will...

  20. Geologic implications of gas hydrates in the offshore of India: Krishna-Godavari Basin, Mahanadi Basin, Andaman Sea, Kerala-Konkan Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, P.; Collett, T.S.; Boswell, R.; Cochran, J.R.; Lall, M.; Mazumdar, A.; Ramana, M.V.; Ramprasad, T.; Riedel, M.; Sain, K.; Sathe, A.V.; Vishwanath, K.; Yadav, U.S.

    history of the Mahanadi Basin is similar to that of the Krishna-Godavari Basin. The Late Jurassic rift structures along the eastern margin of India cut across older NW-SE-trending Permian-Triassic Gondwana grabens including the Mahanadi and Pranhita...-Godavari grabens (Sastri et al., 1981). The Mahanadi graben appears to have a continuation in Antarctica as the Lambert graben (Federov et al., 1982). These structures served to delineate the fluvial drainage system throughout the evolution of the margin...