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Sample records for valles marineris canyon

  1. Valles Marineris and Chryse Outflow Channels

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A color image of Valles Marineris, the great canyon and the south Chryse basin-Valles Marineris outflow channels of Mars; north toward top. The scene shows the entire Valles Marineris canyon system, over 3,000 km long and averaging 8 km deep, extending from Noctis Labyrinthus, the arcuate system of graben to the west, to the chaotic terrain to the east and related outflow canyons that drain toward the Chryse basin. Eos and Capri Chasmata (south to north) are two canyons connected to Valles Marineris. Ganges Chasma lies directly north. The chaos in the southeast part of the image gives rise to several outflow channels, Shalbatana, Simud, Tiu, and Ares Valles (left to right), that drained north into the Chryse basin. The mouth of Ares Valles is the site of the Mars Pathfinder lander.

    This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color; Mercator projection. The image roughly extends from latitude 20 degrees S. to 20 degrees N. and from longitude 15 degrees to 102.5 degrees.

    The connected chasma or valleys of Valles Marineris may have formed from a combination of erosional collapse and structural activity. Layers of material in the eastern canyons might consist of carbonates deposited in ancient lakes, eolian deposits, or volcanic materials. Huge ancient river channels began from Valles Marineris and from adjacent canyons and ran north. Many of the channels flowed north into Chryse Basin.

    The south Chryse outflow channels are cut an average of 1 km into the cratered highland terrain. This terrain is about 9 km above datum near Valles Marineris and steadily decreases in elevation to 1 km below datum in the Chryse basin. Shalbatana is relatively narrow (10 km wide) but can reach 3 km in depth. The channel begins at a 2- to 3-km-deep circular depression within a large impact crater, whose floor is partly covered by chaotic material, and ends in Simud Valles. Tiu and Simud Valles consist of a complex of connected channel floors and chaotic terrain and extend as far south as and connect to eastern Valles Marineris. Ares Vallis originates from discontinuous patches of chaotic terrain within large craters. In the Chryse basin the Ares channel forks; one branch continues northwest into central Chryse Planitia and the other extends north into eastern Chryse Planitia.

  2. Detections of carbonates in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Bultel, B.; Quantin-Nataf, C.; Flahaut, J.; Andréani, M.; Lozac'h, L.

    2015-10-01

    Valles Marineris is a unique place on Mars where deep crust is exposed at its original place [1]. The primitive crust is observed at the base of Coprates Chasma as well as in the eastern parts of Valles Marineris [1].Else where on Mars, several authors [2and references therein] reported key observation of the martian primitive crust being altered thanks to CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) data. Coprates Chasma is a proposed landing site for Mars 2020 mission and is so intensely covered by CRISM data. It allows us to investigate the alteration signs of the primitive crust. We describe here the study of 3 CRISM FRT observations on the wall of Valles Marineris in Coprates Chasma and on a remnant horst in middle of the canyon seeking for alteration minerals.

  3. Valles Marineris tectonism: Questions and suggestions

    NASA Technical Reports Server (NTRS)

    Lucchitta, Baerbel K.; Chapman, Mary G.; Isbell, Nancy K.

    1991-01-01

    Much has been learned about the Valles Marineris, and stratigraphic relations inside the troughs have been reasonably well established. However, many questions remain, especially questions pertaining to tectonism and origin. The following issues are briefly considered: the age of the troughs; the evidence for tectonic origin; the relation of Valles Marineris to the Tharsis rise; and the additional factors which may have influenced the origin of the Valles Marineris.

  4. SHARAD detections of subsurface reflectors near RSL sites on the Tharsis Plateau immediately adjacent to the canyon rim of Valles Marineris

    NASA Astrophysics Data System (ADS)

    Smith, I. B.; Stillman, D. E.; Phillips, R. J.; Forget, F.; Mellon, M. T.; Spiga, A.; Putzig, N. E.

    2014-12-01

    Recurring slope lineae (RSL) are very exciting features that exhibit evidence for water flow on the Martian surface. The number of RSL sites has risen to ~100 since their first detection in 2011. Those sites extend over a large portion of the Valles Marineris margin and nearby smaller canyons, but no source for this flowing water has been identified. Two possible sources exist for water near the Martian equator: the atmospheric and the subsurface. At low latitudes, atmospheric water vapor abundance is extremely low, and condensation of water from the air is unlikely. Furthermore, subsurface water ice is unlikely to remain stable in the long term, but scenarios for retaining ice on shorter timescales have not been fully tested. The Shallow Radar (SHARAD) instrument on Mars Reconnaissance Orbiter has successfully probed the subsurface of Mars to locate dielectric interfaces that delineate volcanic boundaries, layers within the polar ice caps, and ice-rock boundaries. Using the same technique of searching for dielectric contrasts at lower latitudes, we have found several detections at the highest elevations of the Tharsis Plateau, near the cliffs that form Valles Marineris at depths ranging from 30 to 80 m, depending on the dielectric properties of the overlying material. These reflectors are located near the canyon rim and slope towards the canyon, potentially crossing geologic boundaries mapped from surface data. Because of the proximity of the reflectors to RSL and the geometry of the reflections, we hypothesize that SHARAD may be detecting an ice or water reservoir that can act as a source for flowing water on the surface. We test this hypothesis by employing a one-dimensional thermal model to estimate the stability of ground ice over a wide range of durations at this latitude, including recent epochs of high obliquity, when ice would be more stable at low latitudes and for longer periods.

  5. Flight Into Mariner Valley (Valles Marineris, Mars)

    E-print Network

    Flight Into Mariner Valley (Valles Marineris, Mars) Presented by Phil Christensen Mars Space Flight ----------------------------------------------------------------------------------------------------- ------------------------- This work was sponsored by NASA's Science Mission Directorate Mars Exploration Program and was produced for the Mars Exploration Directorate, Mars Odyssey Project, Solar System Visualization Project, Research

  6. Noctis Labyrinthus/Valles Marineris transition

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 27 May 2002) The Science The transition zone between maze-like troughs of Noctis Labyrinthus and the main Valles Marineris canyon system are shown in this THEMIS visible camera image. This huge system of troughs near the equator of Mars was most likely created by tectonic forces which pulled apart the crust. In the top third of the image, on the western side of the northernmost trough, a buildup of relatively bright material on the plateau has led to an overflow into the trough. Most of the bottom of this trough is covered by sediment deposited from the plateau above. On the right-hand side of this same trough, on the southern wall, there is a thin streak of darker material that also seems to originate from the plateau above. This is most likely a gully formation. This feature could also be a dust avalanche, but because no other similar features are seen, this is unlikely. Other dark material deposited by some unknown process can also be seen all around the easternmost ridge in the trough. Near the bottom of the canyon, layers from the center ridges and the canyon wall can be matched, indicating that the ridges are made of the same material as the wall. Near the bottom of the image, there is yet another depression. This trough is filled with sediment deposited from erosion of the trough wall and possibly from the plateau above. All around the walls of this trough a layer of rocky material can be also be seen. It appears that the areas directly below the rocky ledges are 'shielded' from landslide material from above. Finally, in the northwestern wall of this trough, there is an irregular pattern of very bright material not seen anywhere else in the image. Identifying similar formations in other THEMIS visible camera images could provide some context for its occurrence and help us understand how it was formed. The Story Tectonic forces wrenched apart the crust on Mars long ago, forming deep troughs at the Martian equator like the ones seen here. They occur in a transition zone between the maze-like region of Noctis Labyrinthus and the deep canyon system of Valles Marineris, the largest and 'grandest' canyon in the solar system. These cracks in the crust can give geologists a good idea of what has happened over the course of the planet's history. Find out a little yourself by taking a closer look at the western side of the trough in the top third of the image. Can you see how the bright sediment from the plateau above has been whisked over the side, overflowing and building up on the floor below? Follow the south wall of this same trough, and you'll come across a dark streak running down (toward the right side of the image). One possibility is that it could be a dust avalanche, but if that were so, you'd think it would have occurred much more often, in more places than just that one spot. Since it didn't, scientists believe it probably isn't a dust avalanche, but could be a gully instead. There's also some more dark material deposited all around the easternmost ridge in the trough as well. No one is quite sure how it formed there or exactly what it's made of. At the least, what geologists can tell is that the ridges in the trough are made of the same material as the canyon walls, since the layers in each of them match. Finding similarities like these can help piece together the story of Martian geology here. When scientists study THEMIS images, however, they are also on the lookout for anything that looks unusual. Try studying the dark depression that carves out the bottom of this image. It too is filled soft-looking sediments, probably deposited from erosion of the trough wall and possibly from the plateau above. Rocky outcrops all around the walls of this trough shield the areas directly below them from landslides from above. But all that seems pretty regular. Do you see anything that stands out? How about the odd pattern of brighter material that seems almost pasted on the northwestern wall of the trough like dried up glue? This material isn't found elsewhere in this image.

  7. The Layer Cake Walls of Valles Marineris

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This image of the northern wall of Coprates Chasma, in Valles Marineris, was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 1227 UTC (8:27 a.m. EDT) on June 16, 2007, near 13.99 degrees south latitude, 303.09 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 20 meters (66 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point.

    Valles Marineris is a large canyon system straddling Mars' equator, with a total size approximating the Mediterranean Sea emptied of water. It is subdivided into several interconnected 'chasmata' each hundreds of kilometers wide and, in some cases, thousands of kilometers long. The walls of several of the chasmata, including Coprates Chasma, expose a section of Mars' upper crust about 5 kilometers (3 miles) in depth. Exposures like these show the layers of rock that record the formation of Mars' crust over geologic time, much as the walls of the Grand Canyon on Earth show part of our planet's history.

    The upper panel of this montage shows the location of the CRISM image on a mosaic from the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS), taken in longer infrared wavelengths than measured by CRISM. The CRISM image samples the base of Coprates Chasma's wall, including a conspicuous horizontal band that continues along the wall for tens of kilometers to the east and west, and a topographic shelf just above that.

    The middle two panels show the CRISM image in visible and infrared light. In the middle left panel, the red, green, and blue image planes show brightness at 0.59, 0.53, and 0.48 microns, similar to what the human eye would see. Color variations are subdued by the presence of dust on all exposed surfaces. In the middle right panel, the red, green, and blue image planes show brightness at 2.53, 1.51, and 1.08 microns. These three infrared wavelengths are the 'usual' set that the CRISM team uses to provide an overview of infrared data, because dust has a less obscuring effect, and because they are sensitive to a wide variety of minerals. Layering is clearly evident in the wall rocks. The conspicuous band running along the base of the chasma wall appears slightly yellowish, and the scarp at the edge of the topographic bench appears slightly green.

    The bottom two panels use combinations of wavelengths to show the strengths of absorptions that provide 'fingerprints' of different minerals. In the lower left panel, red shows strength of a 0.53-micron absorption due to oxidized iron in dust, green shows strength of an inflection in the spectrum at 0.6 microns that may be related to rock coatings, and blue shows strength of a 1-micron absorption due to the igneous minerals olivine and pyroxene. The conspicuous horizontal band appears slightly blue, indicating a stronger signature of olivine and/or pyroxene. In the lower right panel, red is a measure of an absorption particular to olivine, green is a measure of a 2.3-micron absorption due to phyllosilicates (clay-like minerals formed when rock was subjected to liquid water), and blue is a measure of absorptions particular to pyroxene. The conspicuous horizontal band is now resolved into an upper portion richer in pyroxene, underlain by material richer in olivine than the rest of the wall rock. Also, erosion-resistant material forming the topographic bench is underlain by phyllosilicate-containing material exposed on the scarp.

    Taken together, these data reveal a layer cake-like composition of the crustal material exposed in Coprates Chasma's wall. Most of the rock is rich in pyroxene, which is expected because much of Mars' crust consists of volcanic basaltic rock. However discrete layers are richer in olivine, and in some layers the presence of phyllosilicates indicates interaction of rock with liquid water. Because the phyllosilicate-containing layer is low on the walls and deeply buried, it likely represents an early pe

  8. Landslides in Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1979-01-01

    The morphology of the landslides in the Martian equatorial troughs, the geologic structure of the troughs, the time of emplacement, the similarity to terrestrial landslides, and the origin and mechanism of transport are analyzed. About 35 large landslides well-resolved on Viking images were examined, and it is found that the major landslides cover 31,000 sq km of the trough floors, and individual slides range in area from 40 to 7000 sq km. The morphologic variations of the landslides can be attributed mainly to their degree of confinement on trough floors. Many prominent landslides appear to be of similar age and were emplaced after a major faulting that dropped the trough floors. Most sliding occurred after the created scarps were dissected into spurs, gullies, and tributary canyons. Emplacement of the landslides approximately coincided with a late episode of major eruptive activity of the Tharsis volcanoes, and it is suggested that the slides may have originated as gigantic mudflows with slump blocks at their heads. The large size of many landslides is due to the fault scarps as high as 7 km on which they formed in the absence of vigorous fluvial erosion. The landslides suggest that Mars is earthlike in some respects, which may be important for further evaluations.

  9. Valles Marineris: a past glaciated valley landsystem along the Martian equator

    NASA Astrophysics Data System (ADS)

    Gourronc, M.; Bourgeois, O.; Mège, D.; Bultel, B.; Pochat, S.

    2012-04-01

    Various ice-related features occurring on the floor of Valles Marineris suggest that this canyon system that stretches along the Martian equator has experienced a period of past glacial activity. Three regions of Valles Marineris were investigated, Coprates Chasma, Candor Chasma, and Ius Chasma. Geomorphological observations are based on images and altimetry analysis by using the Context Camera (CTX), the High Resolution Imaging Science Experiment (HiRISE) and MOLA PEDR single tracks. The study reveals some features reminiscent of a past glaciated valley landsystem in these regions. A line running along the base of valley wallslopes and associated with spur and gully morphology can be interpreted as a periglacial trimline. Other landforms on the floor of Candor Chasma can be interpreted as stagnant ice features such as polygonal terrains, chaotic terrains which look similar to terrestrial ablation moraines with kettle holes. Ancient ice probably also persists now in Candor Chasma in the form of a debris covered glacier with a surface elevation that is consistent with that of the trimline. In Coprates Chasma, hanging valleys provide additional evidence for the former existence of an extensive glacial filling of Valles Marineris. Terraced mounds resting on the floor of Coprates Chasma and around basement domes can be interpreted as stagnant remnants of stratified ice. Altogether, these landforms define a full glacial landsystem consistent with global climate models that predict glaciations in Valles Marineris during the Late Amazonian.

  10. Tharsis Volcanoes and Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    1999-01-01

    It is northern summer on Mars and clouds are very common over the famous Tharsis volcanoes during the afternoon. At the far left, a white patchy cloud denotes the location of Olympus Mons. Ascraeus Mons is under the brightest cloud toward the center left, but the volcanoes Pavonis Mons and Arsia Mons (toward lower left below Ascraeus Mons) have much less cloud cover. The patch of clouds toward the upper left mark the location of the Alba Patera volcano. The Valles Marineris trough system--so long that it would stretch across North America--is seen in the lower third of this picture. This is a color composite of 9 red and 9 blue image strips taken by the Mars Global Surveyor Mars Orbiter Camera on 9 successive orbits from pole-to-pole during the calibration phase of the mission in March 1999. The color is computer-enhanced and is not shown as it would actually appear to the human eye.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  11. Geomorphological studies on western Valles Marineris, Mars - landforms and processes

    NASA Astrophysics Data System (ADS)

    D?bniak, K.; Mège, D.; Massé, M.

    2014-04-01

    Context Camera (CTX) images obtained by the Mars Reconnaissance Orbiter (MRO) covered ~85% of the Martian surface to February 2013 [1], including almost 100% coverage of the Valles Marineris trough system. The images of resolution 6 m/pixel play an important role as a background for detailed landform mapping of Mars. We present: (i) a detailed geomorphologic mapping procedure of western Valles Marineris based on USGS ISIS processing, ArcGIS mapping, and incorporation of additional data sets, (ii) observations of chasma floor and wall features.

  12. Progressive Evolution of the Valles Marineris Fault Zone and its Role in Controlling Interior Layered Deposits and Outflow Channels

    NASA Astrophysics Data System (ADS)

    Watkins, J.; Yin, A.

    2012-12-01

    Most recent studies of Valles Marineris concluded that its interior layered deposits (ILDs) were accumulated after the formation of the Valles Marineris trough system. Some workers also suggest that the ILDs originated from sedimentation in lakes within the Valles Marineris troughs, and that the sudden release of lake waters to the northern lowlands created the spectacular outflow channels at the eastern end of the Valles Marineris trough zone, leaving mounds of ILD sediments exposed within the troughs. The sudden release of water has been commonly related to erosion of damming of the troughs induced by glacial or mass-wasting depositional processes. In all existing models linking the ILDs to the outflow channels, the shape of the Valles Marineris trough system upon deposition of the ILDs was regarded to be constant. However, this notion is at odds with the new observation that the development of the Valles Marineris fault zone, a left-slip transtensional structure, continued to be dynamic throughout at least part of the sedimentation of the ILDs. This conflict prompts analysis of the role of the progressive opening of the Valles Marineris trough system in controlling the spatial and temporal evolution of ILDs and their relationship to the formation of the circum-Chryse outflow channels. Here, we test the hypothesis that the Valles Marineris trough system was a single intra-canyon lake and its outlet was progressively opened by normal faulting at the eastern end of the trough zone, releasing the floodwaters that formed the equatorial outflow channels. Our model sharply contrasts alternative mechanisms for producing the outflow channels such as progressive overtopping of structurally isolated lakes, rapid release of a subsurface groundwater aquifer, rapid release of stored ice, and episodic flooding. This tectonic damming makes specific predictions on the spatial relationships among (1) the evolution of the Valles Marineris fault zone, (2) the deposition and development of the ILDs, and (3) the timing and location of major outflow channels. Systematic geologic and geomorphic mapping of these relationships at locations of possible tectonic dams in northeastern Valles Marineris is currently in progress.

  13. New models for the origin of Valles Marineris closed depressions

    SciTech Connect

    Spencer, J.R.; Fanale, F.P. )

    1990-08-30

    Current models for the formation of the abundant large closed depressions of Valles Marineris have serious shortcomings. Purely tectonic mechanisms are inconsistent with the morphology of many depressions, and removal of large quantities of ground ice from the canyon walls is inconsistent with the observed strength of the walls. Accordingly, the authors offer some alternatives. One possibility involves decay of ice-rich bodies occupying partially sediment-choked ancient graben that predated the overlying cratered and ridged plains. Other possibilities involve the removal of massive equatorial carbonate deposits storing much of the planet's CO{sub 2} inventory, generated during greenhouse conditions on early Mars. Solution by carbonic acid derived from the atmosphere (analogous to terrestrial karst) requires extensive recycling of the available water supply. Solution by various groundwater acids, possibly derived from the Tharsis magmas, requires less water, especially if only the smaller closed depressions are due to carbonate decay. Alternatively, volume loss due to decarbonation of carbonate during early high heat flow or a later Tharsis-related heat pulse can produce extensive collapse, especially if the carbonates have high silica content.

  14. Characterization of Layered Deposits inside Valles Marineris

    NASA Technical Reports Server (NTRS)

    Weitz, Catherine; Anderson, Scott; Parker, Tim; Grant, John

    2005-01-01

    This report represents the final progress report on our study of the Melas Chasma region on Mars that was proposed as a landing site for the Mars Exploration Rover mission (MER). During this two-year proposal (which was extended over three years by a no-cost extension), we conducted a thorough study of the layered deposits in western Melas Chasma that had been the location of a high priority MER mission landing ellipse within Valles Marineris. All available data sets from orbiter missions, including MOC, MOLA, THEMIS visible and infrared images were all used to analyze this site. The major outcome of this work was a published paper in the Journal of Geophysics and Research Planets [Weitz et al., 2004]. Our geologic mapping and interpretation of the MOC images suggest the landing ellipse contains three main geomorphologic units: (1) a blocky deposit consisting of bright blocks in a darker matrix (BD); (2) sand sheets composed of dark dunes; and (3) landslide deposits emanating from the wallrock to the west [Weitz et al., 2003]. Furthermore, we propose that the morphology of the BD unit in western Melas is a mass wasting deposit composed of blocks of Interior Layered Deposits (ILDs) mixed in with wallrock material. However, more recent MOC images indicate that in the eastern portion of the ellipse and adjacent to a large hill, there are blocks of material resembling those seen in BD. Hence, we cannot rule out the source of BD was this hill. Unfortunately, sand dunes obscure much of the deposit around this hill, making it impossible to precisely determine the connection between the hill and BD, whereas BD can be traced directly to the southern Melas wallrock. If BD resulted from a mass wasting event in the southern wallrock, then we would expect the material to be concentrated further to the north, as now appears to be the case. In summary, the exact source location for BD continues to remain a mystery, but we favor an origin from either the southern wallrock [Weitz et el., 2002] or the eastern hill.

  15. New evidence for a magmatic influence on the origin of Valles Marineris, Mars

    USGS Publications Warehouse

    Dohm, J.M.; Williams, J.-P.; Anderson, R.C.; Ruiz, J.; McGuire, P.C.; Komatsu, G.; Davila, A.F.; Ferris, J.C.; Schulze-Makuch, D.; Baker, V.R.; Boynton, W.V.; Fairen, A.G.; Hare, T.M.; Miyamoto, H.; Tanaka, K.L.; Wheelock, S.J.

    2009-01-01

    In this paper, we show that the complex geological evolution of Valles Marineris, Mars, has been highly influenced by the manifestation of magmatism (e.g., possible plume activity). This is based on a diversity of evidence, reported here, for the central part, Melas Chasma, and nearby regions, including uplift, loss of huge volumes of material, flexure, volcanism, and possible hydrothermal and endogenic-induced outflow channel activity. Observations include: (1) the identification of a new > 50??km-diameter caldera/vent-like feature on the southwest flank of Melas, which is spatially associated with a previously identified center of tectonic activity using Viking data; (2) a prominent topographic rise at the central part of Valles Marineris, which includes Melas Chasma, interpreted to mark an uplift, consistent with faults that are radial and concentric about it; (3) HiRISE-identified landforms along the floor of the southeast part of Melas Chasma that are interpreted to reveal a volcanic field; (4) CRISM identification of sulfate-rich outcrops, which could be indicative of hydrothermal deposits; (5) GRS K/Th signature interpreted as water-magma interactions and/or variations in rock composition; and (6) geophysical evidence that may indicate partial compensation of the canyon and/or higher density intrusives beneath it. Long-term magma, tectonic, and water interactions (Late Noachian into the Amazonian), albeit intermittent, point to an elevated life potential, and thus Valles Marineris is considered a prime target for future life detection missions. ?? 2008 Elsevier B.V.

  16. Evidence for precipitation on Mars from dendritic valleys in the Valles Marineris area.

    PubMed

    Mangold, Nicolas; Quantin, Cathy; Ansan, Véronique; Delacourt, Christophe; Allemand, Pascal

    2004-07-01

    Dendritic valleys on the plateau and canyons of the Valles Marineris region were identified from Thermal Emission Imaging System (THEMIS) images taken by Mars Odyssey. The geomorphic characteristics of these valleys, especially their high degree of branching, favor formation by atmospheric precipitation. The presence of inner channels and the maturity of the branched networks indicate sustained fluid flows over geologically long periods of time. These fluvial landforms occur within the Late Hesperian units (about 2.9 to 3.4 billion years old), when Mars was thought to have been cold. Our results suggest a period of warmer conditions conducive to hydrological activity. PMID:15232103

  17. Evidence of a Paleolake in the central Valles Marineris

    NASA Astrophysics Data System (ADS)

    Harrison, K. P.

    2007-12-01

    The Valles Marineris (VM) canyon system of Mars is closely related to large flooding channels, some of which emerge full born from chaotic terrain in canyon floors. Coprates Chasma, one of the largest VM canyons, is connected at its eastern end to chaotic terrain Capri Chasma. Despite the likely large volumes of groundwater that discharged from Capri Chasma [1], no evidence of related fluvial activity in Coprates Chasma has thus far been reported. We present an analysis of the regional topography which, together with photogeologic interpretation of available imagery, suggests that ponding due to late-stage discharge of water from Capri Chasma chaotic terrain produced a shallow lake spanning parts of Melas, Coprates, Capri and Eos Chasmata (MCCE). Overflow of this lake at its eastern end resulted in delivery of water to downstream chaos regions and outflow channels. Our ponding hypothesis is motivated primarily by the identification of scarp and terrace features which, despite a lateral spread of about 1500 km, have similar elevations. Furthermore, these elevations correspond to the maximum ponding elevation of the region (-3562 m). Mean lake depth is 842 m. Simulated ponding in the MCCE system yields an overflow point at its eastern extremity, in Eos Chasma. The neighborhood of this overflow point contains clear indicators of fluvial erosion in a consistent east-west orientation (Figure 4). Specifically, scour marks suggest an eastward convergence of flow lines. Downstream of the overflow point, the direction set by the scour marks is paved by a smooth deposit leading directly to a scoured channel entering the next major region of chaotic terrain, Aurorae Chaos. The smooth deposit is likely made up of remnants of the interior deposit breached by the MCCE paleolake overflow. The next region of chaotic terrain downstream of Aurorae Chasma is Hydraotes Chaos, which lies in a relatively deep depression and would be the next significant ponding location for flow originating in the MCCE region. Crucially, it is also the only other Chryse Planitia chaos to exhibit terraces, which have been attributed a lacustrine origin by other authors [2]. References: [1] Carr M. H. (1979) JGR, 84, 2995-3007. [2] Ori G. G. and Mosangini C. (1998) JGR, 103, 22713-22724.

  18. Landslide on Valles Marineris: morphology and flow dynamics

    NASA Astrophysics Data System (ADS)

    Sato, H.; Kurita, K.; Baratoux, D.; Pinet, P.

    2008-09-01

    Introduction: Valles Marineris is known as a place of numerous and well preserved landslides on Mars. In comparison with terrestrial landslides, martian landslides are distinctive in their size and morphology. As a consequence of the topography of the canyon, the averaged drop height of these landslides is about 6.5 km and the averaged volume is about 102~4 km3[1], which is 2~3 orders of magnitude larger than terrestrial ones, at the exception of marine landslides[2]. As for the morphology, clear levees with longitudinal lineations are typical features of martian landslides, whereas surfaces of the terrestrial mass movements are dominated by a rather chaotic topography with, in some cases, the occurrence of transverse ridges. The characteristics of the deposits should reflect the dynamics of the emplacement and the subsurface material properties. In particular, there is a longstanding debate about the relation between the long run-out length and the existence of subsurface volatiles (water ice, clathrates, ground water) [1,3,4,5,6,7]. The motivation of our research is the fact that material properties are expected to be deduced from the morphology of the deposits and the knowledge of the flow dynamics. Then, the characteristics of subsurface materials partially collapsed as mass movements could be documented as a function of time, considering the age of each landslide. In this study, we focus on the longitudinal grooves which are found on the surface of landslide deposits at Valles Marineris (Fig.1). This pattern is a typical feature in the martian landslides[3], and extremely rarely observed in the terrestrial mass movements. The origin is not well clarified, but it seems strong relation with the flow style or physical property of transported materials. With the objective to determine the condition of formation of the lineations, the geometric characteristics (volume, surface, thickness, run-out length) of lineated and non-lineated landslides are compared. Then, the difference in flow dynamics are discussed based on the physics of granular flow. Topographic measurements are derived from HRSC and MOLA data. HRSC, MOC, THEMIS-VIS are used for the morphological observations. Result and Discussions: Not all the landslides have longitudinal lineation as shown in Fig.1. Almost half numbers of landslides observed in Valles Marineris show irregularly shaped knobby surface as shown in Fig.2. We classified all the landslides in this area as lineated type and knobby type, including a few exceptions. We compare two types of landslide by measured morphological parameters, such as volume, averaged thickness, area, maximum run-out (Lmax), and maximum drop height (Hmax). When we compare by volume and Hmax/Lmax plot, where Hmax/Lmax corresponds to the apparent coefficient of friction[2], a clear difference is recognized. Landslides of the lineated type show a negative correlation of Hmax/Lmax with volume, a similar trend to terrestrial dry landslides. On the other hand, the plots of knobby type concentrate in a small area at larger volumes without any clear correlation of two parameters. From the comparison at the plot of averaged thickness and total volume of deposit, lineated type show systematically thinner geometry than knobby type, bounded around 200 to 250 m. From the comparison of averaged thickness and root square of deposit area (Fig.5), a roughly linear correlation is reported for the lineated type. The square root of deposit area means the index length of horizontal shape of deposit. Usually the deposit of landslide at Valles Marineris spread out at flat broad valley floor showing semi-radialy spreaded shape. Thus it can be invoked as index length independent with actual horizontal deposit shape. The linear correlation of thickness and square of the deposit area for the lineated type implies that deposits shapes are homothetic, and keep similarity. This observation is striking given the large range of volumes reported. In contrast, a constant square of deposit area for thicknesses ranging from 100 to 600 meters is reported. T

  19. Part 2: Sedimentary geology of the Valles, Marineris, Mars and Antarctic dry valley lakes

    NASA Technical Reports Server (NTRS)

    Nedell, Susan S.

    1987-01-01

    Detailed mapping of the layered deposits in the Valles Marineris, Mars from high-resolution Viking orbiter images revealed that they from plateaus of rhythmically layered material whose bases are in the lowest elevations of the canyon floors, and whose tops are within a few hundred meters in elevation of the surrounding plateaus. Four hypotheses for the origin of the layered deposits were considered: that they are eolian deposits; that they are remnants of the same material as the canyon walls; that they are explosive volcanic deposits; or that they were deposited in standing bodies of water. There are serious morphologic objections to each of the first three. The deposition of the layered deposits in standing bodies of water best explains their lateral continuity, horizontality, great thickness, rhythmic nature, and stratigraphic relationships with other units within the canyons. The Martian climatic history indicated that any ancient lakes were ice covered. Two methods for transporting sediment through a cover of ice on a martian lake appear to be feasible. Based on the presently available data, along with the theoretical calculations presented, it appears most likely that the layered deposits in the Valles Marineris were laid down in standing bodies of water.

  20. Melas Chasma: A Mars Pathfinder view of Valles Marineris

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.; Murchie, Scott

    1994-01-01

    A Mars Pathfinder landing site in Melas Chasma (Valles Marineris) would yield significant science return, but is outside present mission constraints. In Melas Chasma, Mars Pathfinder could investigate minimally altered basaltic material, sedimentary deposits, chemical weathering, tectonic features, the highland crust, equatorial weather, and Valles mists. Critical issues include the following: (1) nature and the origin of the Valles interior layered deposits, important for understanding water as a sedimentary and chemical agent, and for the past existence of of environments favorable for life; (2) compositions of little-altered basaltic sands, important for understanding magma genesis and weathering on Mars, and the martian meteorites; and (3) structure and composition of the highland crust, important for understanding Mars' early history .

  1. Origin and evolution of the layered deposits in the Valles Marineris, Mars

    SciTech Connect

    Nedell, S.S.; Squyres, S.W.; Andersen, D.W.

    1987-06-01

    Four hypotheses are discussed concerning the origin of the layered deposits in the Martian Valles Marineris, whose individual thicknesses range from about 70 to 300 m. The hypothesized processes are: (1) aeolian deposition; (2) deposition of remnants of the material constituting the canyon walls; (3) deposition of volcanic eruptions; and (4) deposition in standing bodies of water. The last process is chosen as most consistent with the rhythm and lateral continuity of the layers, as well as their great thickness and stratigraphic relationship with other units in the canyons. Attention is given to ways in which the sediments could have entered an ice-covered lake; several geologically feasible mechanisms are identified. 46 references.

  2. Dark materials in Valles Marineris: Indications of the style of volcanism and magmatism on Mars

    SciTech Connect

    Geissler, P.E.; Singer, R.B. ); Lucchitta, B.K. )

    1990-08-30

    Rifting on the equatorial canyon system of Valles Marineris provides a unique view of the interior of the Martian crust to depths reaching 7 km, exposing several in situ bedrock units which testify to past volcanic and magmatic processes on Mars. A thick, regionally extensive deposit observed in Coprates and Juventae chasmata is interpreted on the basis of spectral reflectance, erosional morphology, and tendency for eolian mobilization to be composed of mafic glass, possibly an ancient Martian analogue of the lunar terra mantling deposits. Spectral mapping suggests that the dark floor-covering materials in the lower canyons are derived from this unit. A series of cliffs in the Ophir Chasma wall rock is interpreted to be exposures of resistant bedrock; the spectral signature of this massive and uniform unit most closely resembles that of terrestrial mafic rocks altered to or coated by crystalline hematite. Application of computer mapping techniques to probable young volcanic materials in the central troughs yields an inferred distribution of volcanic activity consistent with the interpretation of extrusion along faults near the margins of the canyon floors. This result supports the hypothesis that the valles originated through tectonic extension.

  3. Stability of rock slopes in Valles Marineris, Mars Richard A. Schultz

    E-print Network

    Stability of rock slopes in Valles Marineris, Mars Richard A. Schultz Geomechanics-Rock Fracture slope measurements from the Mars Orbiter Laser Altimeter (MOLA), in conjunction with the Rock Mass interior deposits (30 rock beneath wallrock

  4. New Evidence that the Valles Marineris Interior Layered Deposits Formed in Standing Bodies of Water

    NASA Technical Reports Server (NTRS)

    Weitz, C. M.; Parker, T. J.

    2000-01-01

    Our results indicate that the best explanation for the origin and current morphology of the Valles Marineris interior layered deposits is by deposition of sediments, including chemical precipitates, in standing bodies of water.

  5. Mobility of large rock avalanches: evidence from Valles Marineris, Mars

    USGS Publications Warehouse

    McEwen, A.S.

    1989-01-01

    Measurements of H/L (height of drop/length of runout) vs. volume for landslides in Valles Marineris on Mars show a trend of decreasing H/L with increasing volume. This trend, which is linear on a log-log plot, is parallel to but lies above the trend for terrestrial dry rock avalanches. This result and estimates of 104 to 105 Pa yield strength suggest that the landslides were not water saturated, as suggested by previous workers. The offset between the H/L vs. volume trends shows that a typical Martian avalanche must be nearly two orders of magnitude more voluminous than a typical terrestrial avalance in order to achieve the same mobility. This offset might be explained by the effects of gravity on flows with high yield strengths. These results should prove useful to future efforts to resolve the controversy over the mechanics of long-runout avalanches. -Author

  6. Impact craters and landslide volume distribution in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    De Blasio, Fabio

    2014-05-01

    The landslides in the wide gorge system of Valles Marineris (Mars) exhibit volumes of the or-der of several hundred 1,000 km3 and runouts often in the excess of 80 km. Most landslides have occurred at the borders of the valleys, where the unbalanced weight of the 5-8 km high headwalls has been evidently sufficient to cause instability. Previous analysis has shown that the mechanical conditions of instability would not have been reached without external triggering fac-tors, if the wallslope consisted of intact rock. Among the factors that have likely promoted instability, we are currently analyzing: i) the possibility of rock weakening due to weathering; ii) the alternation of weak layers within more massive rock; weak layers might for example due to evaporites, the possible presence of ice table at some depth, or water; iii) weakening due to impact damage prior to the formation of Valles Marineris; studies of impact craters on Earth show that the volumes of damaged rock extends much deeper than the crater itself; iv) direct triggering of a landslide due to the seismic waves generated by a large meteoroid impact in the vicinity, and v) direct triggering of a landslide con-sequent to impact at the headwall, with impulsive release of momentum and short but intense increase of the triggering force. We gathered a large database for about 3000 Martian landslides that allow us to infer some of their statistical properties supporting our analyses, and especially to discriminate among some of the above listed predisposing and triggering factors. In particular, we analyse in this contribution the frequency distribution of landslide volumes starting from the assumption that these events are controlled by the extent of the shock damage zones. Relative position of the impact point and damage zones with respect to the Valles Marineris slopes could in fact control the released volumes. We perform 3D slope stability analy-sis under different geometrical constraints (e.g. crater size and position, slope angle and height, size of the relative shock damage zone) starting from rock mass properties calibrated in a previous study (Crosta et al., 2014). We report about the synthetic volume frequency distribution gen-erated by considering the most critical failure surfaces for the different geometrical constraints and the frequency distribution of craters on Mars surface (e.g., Hartmann and Neukum, 2001). 1. Crosta, G.B., Utili, S., De Blasio, F.V., Castellanza, R. (2014)Reassessing rock mass properties and slope instability triggering conditions in Valles Marineris, Mars.Earth Planetary Science Letters, 338, 329-343. http://dx.doi.org/10.1016/j.epsl.2013.11.053 2. Hartmann, W., and Neukum, G., (2001). Crater Chronology and the evolution of Mars. Space Science Reviews 96: 165-194.

  7. Thursday, March 26, 2009 POSTER SESSION II: MARS: AQUEOUS PROCESSES IN VALLES MARINERIS

    E-print Network

    Rathbun, Julie A.

    ): Walls, Mounds, Moats, and Volcanoes [#2068] Synthesis of research concerning lakes in the Valles624.pdf #12;LAKES IN VALLES MARINERIS, MARS (I): WALLS, MOUNDS, MOATS, AND VOLCANOES. B. K. Lucchitta in lakes. Recent evidence, summarized here, sheds new light on this old problem. Morphology and composition

  8. Reconstructing the Catastrophic Flood History of Eastern Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Warner, N. H.; Sowe, M.; Gupta, S.; Dumke, A.

    2014-12-01

    The km-deep chaotic terrains of the eastern Valles Marineris region have long been recognized as depositional sinks for eolian and air fall material. Furthermore, many have suggested that groundwater influx into these basins may have contributed to the development of lacustrine environments, basin-floor fluvial systems, and basin-marginal catastrophic outflow channels. However, the lacustrine hypothesis has been challenged by suggestions that the proposed fluvial-lacustrine landforms may have formed by non-aqueous mechanisms (e.g. volcanic) or processes that require low volumes of liquid water (e.g. glacial). In this work, we describe the basin-marginal landscape of eastern Valles Marineris at the junction between Eos Chaos and Aurorae Chaos basins. Using new high resolution topography data (HRSC DTMs), imagery (CTX), and impact crater chronology we identify and describe four catastrophic outflow channels that occur along a 500 km arc that traces the eastern margin of Eos Chaos. The fluvial origin of these channels is evidenced by (1) occurrence of longitudinal grooves that cross-cut Noachian-age (3.8 Ga) highland terrain, (2) multiple bedrock terraces that occur at consistent elevations across each channel, (3) streamlined landforms, (4) inner channels headed by cataracts, and (5) crater size frequency distributions that indicate resurfacing of highland craters (Figure 1). The terraces provide evidence for progressive incision from individual flood events with discharges of ~106 - 108 m3 s-1. The topographically highest terrace in each channel initiates at the same elevation of ~1000 m along the entire basin margin. The lowest terraces and grooved terrains require up to 5 km of total incision, down to a base level of ~4100 m that is set by the downstream floor of Aurorae Chaos. The observations not only require a regional topographic control on flood initiation in all channels, but the existence of a base level that suggests the chaotic terrains pre-date the flood events. This is confirmed by the older crater retention age of the basin floors (3.5 Ga) relative to the outflow channels (3.0 Ga). These combined observations point to the past occurrence of an upstream lake within Eos Chaos, spillover of that lake along its eastern margin, and incision of outflow channels, integrating Eos Chaos with Aurorae Chaos.

  9. Hydrated mineral stratigraphy of Ius Chasma, Valles Marineris

    USGS Publications Warehouse

    Roach, L.H.; Mustard, J.F.; Swayze, G.; Milliken, R.E.; Bishop, J.L.; Murchie, S.L.; Lichtenberg, K.

    2010-01-01

    New high-resolution spectral and morphologic imaging of deposits on walls and floor of Ius Chasma extend previous geomorphic mapping, and permit a new interpretation of aqueous processes that occurred during the development of Valles Marineris. We identify hydrated mineralogy based on visible-near infrared (VNIR) absorptions. We map the extents of these units with CRISM spectral data as well as morphologies in CTX and HiRISE imagery. Three cross-sections across Ius Chasma illustrate the interpreted mineral stratigraphy. Multiple episodes formed and transported hydrated minerals within Ius Chasma. Polyhydrated sulfate and kieserite are found within a closed basin at the lowest elevations in the chasma. They may have been precipitates in a closed basin or diagenetically altered after deposition. Fluvial or aeolian processes then deposited layered Fe/Mg smectite and hydrated silicate on the chasma floor, postdating the sulfates. The smectite apparently was weathered out of Noachian-age wallrock and transported to the depositional sites. The overlying hydrated silicate is interpreted to be an acid-leached phyllosilicate transformed from the underlying smectite unit, or a smectite/jarosite mixture. The finely layered smectite and massive hydrated silicate units have an erosional unconformity between them, that marks a change in surface water chemistry. Landslides transported large blocks of wallrock, some altered to contain Fe/Mg smectite, to the chasma floor. After the last episode of normal faulting and subsequent landslides, opal was transported short distances into the chasma from a few m-thick light-toned layer near the top of the wallrock, by sapping channels in Louros Valles. Alternatively, the material was transported into the chasma and then altered to opal. The superposition of different types of hydrated minerals and the different fluvial morphologies of the units containing them indicate sequential, distinct aqueous environments, characterized by alkaline, then circum-neutral, and finally very acidic surface or groundwater chemistry. ?? 2009 Elsevier Inc. All rights reserved.

  10. Stratigraphic evidence of past fluvial activity in southern Melas Chasma, Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Davis, Joel; Grindrod, Peter

    2014-05-01

    During the late Noachian and early Hesperian periods, listric faulting led to the development of a series of hanging depressions throughout the Valles Marineris canyon system [1]. One such depression, situated on the southern wall of Melas Chasma, forms an enclosed basin which has since undergone modification from the late Hesperian to Amazonian. There is a multitude of evidence suggesting that the basin (hereon in referred to as the Southern Melas Chasma Basin; SMCB) was once host to active fluvial processes, that at minimum lasted for several hundred years [2,3]. Central to this is what appears to be the remains of a palaeolake, which is approximately 80 by 40 kilometres in area. The palaeolake contains a complex sequence of sedimentary stratigraphy, which includes several structures that resemble deltas and/or submarine fans on both the east and west side of the basin [4], and appear to originate from a network of channels and valleys that terminate in the basin. Previous studies have shown that the western valley network has drainage densities similar to terrestrial values and a dendritic nature that is indicative of precipitation and surface runoff [3]. Higher resolution mapping of the SMCB is important to further understand the stratigraphic succession and geomorphology, and to quantify how long liquid water may have been present within the basin. For this study, new digital elevation models (DEMs) have been produced in SOCET SET using stereo images from the Context Camera (CTX) and the High Resolution Imaging Science Experiment (HiRISE), both aboard the Mars Reconnaissance Orbiter. The DEMs have been produced at ~6 and ~1 m/pixel vertical resolution for CTX and HiRISE respectively. There is approximately 150-200 m of sediment within the stratigraphic succession; some individual strata are less than 10 m thick. The delta/fan structures appear to occur at different stratigraphic positions low down within the sequence. Clinoform-like and cross-bedded structures are shown to occur near the top of the sequence (a contrast to the laterally expansive, planar beds below), which suggest a significant change in depositional conditions within the SMCB during the time liquid water was stable. References: 1. Andrews-Hanna, J. C. The formation of Valles Marineris: 3. Trough formation through super-isostasy, stress, sedimentation, and subsidence. J. Geophys. Res. 117, E06002 (2012). 2. Mangold, N., Quantin, C., Ansan, V., Delacourt, C. & Allemand, P. Evidence for precipitation on Mars from dendritic valleys in the Valles Marineris area. Science 305, 78-81 (2004). 3. Quantin, C. Fluvial and lacustrine activity on layered deposits in Melas Chasma, Valles Marineris, Mars. J. Geophys. Res. 110, E12S19 (2005). 4. Metz, J. M. et al. Sublacustrine depositional fans in southwest Melas Chasma. J. Geophys. Res. 114, E10002 (2009).

  11. Mineralogical and morphological study of the chaotic terrains of Valles Marineris, Mars: Insights into their geologic history

    NASA Astrophysics Data System (ADS)

    Flahaut, J.; Bishop, J. L.; Fueten, F.; Quantin, C.; Van Westrenen, W.; Davies, G. R.

    2013-12-01

    Following the OMEGA/Mars Express discovery of sulfates in the Valles Marineris area, a wide range of data, including the recent CRISM (The Compact Reconnaissance Imaging Spectrometer for Mars) observations, has been used to refine these detections. The present study focuses on three chasmata located at the border between the eastern end of Valles Marineris and at the onset of the chaotic terrains of Margaritifer Terra. Ganges Chasma, Capri Chasma and Juventae Chasma all share common features with the chaotic terrains, such as collapse plateaus and chaotic mounds, suggesting a aqueous history, but they are also affected by the east-west extensive tectonics of Valles Marineris and are thus considered part of the rift system. OMEGA and CRISM surveys show that, similarly to the rest of Valles Marineris, these three chasmata are filled with thick, massive sulfate-rich interior layered deposits (ILDs). A succession of a Mg monohydrated sulfate rich unit (characterized by diagnostic absorptions at 2.13 and 2.4 ?m) capped by a polyhydrated sulfate rich unit (1.9 and 2.4 ?m absorptions) is generally observed (Bishop et al., 2009; Flahaut et al., 2010). However, a number of other spectral features are noted, as additional absorptions between 2.2 and 2.3 ?m which could indicate the presence of hydrated silicates (clays or opaline silica) or additional ferric sulfates (e.g., Flahaut et al., 2010). More polyhydrated sulfates might be present as thin layers down in the ILD section in both Capri and Ganges Chasmata. The ILDs are distributed as mesas that might have been more extensive in the past, and that are overlapping the chaotic floor. CRISM data show that Fe/Mg-bearing phyllosilicates are detected in the upper part of the chaotic knobs that form the floor, thanks to their sharp 1.9 and 2.3 ?m spectral features. The mounds are surrounded by abundant dark sands forming ergs. CRISM spectra show a wide 1 ?m absorption feature, associated to weaker 2 ?m absorptions. This suggests that this sand is enriched in olivine, mixed with a high calcium pyroxene. It was previously suggested that this sand could potentially derive from the canyon walls (Chojnacki et al., 2012). However, it is not as abundant in other chasmata of Valles Marineris, suggesting a chaos-related origin. We argue that its source could be the extensive olivine-rich layer that is present in Margaritifer Terra and is exposed on the floor of at least eastern Capri and Ganges Chasmata (Flahaut et al., 2012). The units bearing these different signatures have different ages, allowing us to propose a reconstruction of part of the history of Valles Marineris. This history implies multiple water discharge episodes, during but also after the chaos emplacement, in the Hesperian and Amazonian periods. The water-rich history of this area, coupled with the unique geological record of Valles Marineris make these three chasmata prime targets for future Mars exploration.

  12. Sedimentation, volcanism, and ancestral lakes in the Valles Marineris: Clues from topography

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.; Isbell, N. K.; Howington-Kraus, A.

    1993-01-01

    Compilation of a simplified geologic/geomorphic map onto a digital terrain model of Valles Marineris has permitted quantitative evaluations of topographic parameters. The study showed that, if their interior layered deposits are lacustrine, the ancestral Valles Marineris must have consisted of isolated basins. If, on the other hand, the troughs were interconnected as they are today, the deposits are most likely to volcanic origin, and the mesas in the peripheral troughs may be table mountains. The material eroded from the trough walls was probably not sufficient to form all of the interior layered deposits, but it may have contributed significantly to their formation.

  13. Ancient groundwater flow in the Valles Marineris on Mars inferred from

    E-print Network

    Treiman, Allan H.

    LETTERS Ancient groundwater flow in the Valles Marineris on Mars inferred from fault trace ridges e-mail: treiman@lpi.usra.edu Published online: XX Month XXXX; doi:10.1038/ngeoXXXX Groundwater of bedrock3­6 .2 Understanding groundwater flow is also important for assessing3 the possibility of past

  14. Topography of Valles Marineris: Implications for erosional and structural history

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.; Isbell, N. K.; Howington-Kraus, A.

    1994-01-01

    Compilation of a simplified geologic/geomorphic map onto digital terrain models of the Valles Marineris permitted an evaluation of elevations in the vicinity of the troughs and the calculation of depth of troughs below surrounding plateaus, thickness of deposits inside the troughs, volumes of void spaces above geologic/geomorphic units, and volumes of deposits. The central troughs north Ophir, north and central Candor, and north Melas Chasmata lie as much as 11 km below the adjacent plateaus. In Ophir and Candor chasmata, interior layered deposits reach 8 km in elevation. If the deposits are lacustrine and if all troughs were interconnected, lake waters standing 8 km high would have spilled out of Coprates Chasma onto the surrounding plateaus having surface elevations of only 4-5 km. On the other hand, the troughs may not have been interconnected at the time of interior-deposit emplacement; they may have formed isolated ancestral basins. The existence of such basins is supported by independent structural and stratigraphic evidence. The ancestral basins may have eventually merged, perhaps through renewed faulting, to form northern subsidiary troughs in Ophir and Candor Chasmata and the Coprates/north Melas/Ius graben system. The peripheral troughs are only 2-5 km deep, shallower than the central troughs. Chaotic terrain is seen in the peripheral troughs near a common contour level of about 4 km on the adjacent plateaus, which supports the idea of release of water under artesian pressure from confined aquifers. The layered deposits in the peripheral troughs may have formed in isolated depressions that harbored lakes and predated the formation of the deep outflow channels. (If these layered deposits are of volcanic origin, they may have been emplaced beneath ice in the manner of table mountains.) Areal and volumetric computations show that erosion widened the troughs by about one-third and that deposits occupy one-sixth of the interior space. Even though the volume eroded is larger than the volume deposited, topographic and geologic considerations imply that material eroded from trough walls was probably part of the interior layered deposits but not their sole source. Additional material may have come from subterranean piping, from reworking of local disintegration products on the floors, such as chaotic materials, or from eolian influx. But overall it is likely that the additional material is volcanic and that it forms mostly the upper, more diversely bedded layers of the interior deposits.

  15. Slope stability analysis for Valles Marineris, Mars: a numerical analysis of controlling conditions and failure types

    NASA Astrophysics Data System (ADS)

    Crosta, G.; Castellanza, R.; De Blasio, F.; Utili, S.

    2012-04-01

    Valles Marineris (VM hereafter) in the equatorial area of Mars exhibits several gravitative failures often involving the whole 6-8 km thickness of the valley walls. The failures have resulted in a series of long-runout landslides up to several hundred cubic kilometres in volume (Quantin et al., 2004), and the formation of sub-circular alcoves perched on the top. Several questions arise as to forces at play in the stability of the walls of VM, the geometrical shape of the alcoves and the shape and long-runout of the landslides (see for example Lucas et al., 2011). In this work, we concentrate on the stability analysis of the walls of VM with two precise questions in mind starting from past studies (Bigot-Cormier and Montgomery, 2006; Neuffer and Schultz, 2006, Schultz, 2002). The first concerns the properties of the materials that give origin to instability. We performed several finite element and discrete element calculations tailored to slope stability analysis based on the genuine shape of the walls of VM taken from the MOLA topographic data. We considered stratified and differently altered/degraded materials to define the range of physical mechanical properties required for failure to occur and to explain the discrete distribution of failures along the VM valley flanks. A second question addressed in this work is the geometrical shape of the sub-circular alcoves. Normally, these shapes are commonplace for slopes made of uniform and isotropic properties, and are also observed in subaqueous environment. We performed calculations taking into consideration the progressive failure in the slope showing the final results in terms of surface failure geometry. Bigot-Cormier, F., Montgomery, D.R. (2007) Valles Marineris landslides: Evidence for a strength limit to Martian relief? Earth and Planetary Science Letters, 260, 1-2, 15, 179-186 Lucas, A., Mangeney, A., Mège, D., and Bouchut, F., 2011. Influence of the scar geometry on landslide dynamics and deposits: Application to Martian landslides, J. Geophys. Res. - Planets, 116, E10001, DOI: 10.1144/1470-9236/05-042 Quantin, C., Allemand, P., Delacourt, C. (2004) Morphology and geometry of Valles Marineris landslides. Planetary and Space Science, 52, 11, 1011-1022 Neuffer, D.P., R.A. Schultz (2006) Mechanisms of slope failure in Valles Marineris, Mars. Quarterly Journal of Engineering Geology and Hydrogeology, 39,.3, 227-240 Schultz, R.A. (2002) Stability of rock slopes in Valles Marineris, Mars. Geophysical Research Letters, 29, 1932, doi:10.1029/2002GL015728

  16. One million cubic kilometers of fossil ice in Valles Marineris: Relicts of a 3.5 Gy old glacial landsystem along the Martian equator

    E-print Network

    Mege, Daniel

    . It is associated with lateral benches, hanging valleys and truncated spurs. Comparisons with terrestrial analogs suggest that Valles Marineris, the giant valley system that stretches along the Martian equator escarpment has been spectacularly preserved along valley walls throughout Valles Marineris. The boundary

  17. New hydrated mineral detections in the ILDs of Valles Marineris: Insights into their aqueous history

    NASA Astrophysics Data System (ADS)

    Flahaut, J.; Bishop, J. L.; Fueten, F.; Quantin, C.; Thollot, P.; van Westrenen, W.; Davies, G. R.

    2014-04-01

    This paper presents a survey of the mineralogical diversity of the Interior Layered Deposits (ILDs) of Valles Marineris (VM) and Margaritifer Terra (MT) as determined with the highresolution hyperspectral imager CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) onboard MRO (Mars Reconnaissance Orbiter). A particular emphasis is made on localized detections of new hydrated phases within the dominantly sulfate-rich deposits. These detections are compared with other recent detections of unindentified minerals across the entire region [e.g. 10-19]. Characterizing the entire mineral assemblages at these sites is designed to provide more information on the chemistry of those complex aqueous deposits and their potential formation mechanism(s).

  18. Fault-Continuation Ridges in the Valles Marineris, Mars: Evidence for Groundwater Circulation

    NASA Astrophysics Data System (ADS)

    Treiman, A. H.; Spiker, K.

    1996-03-01

    The walls of the Valles Marineris (VM) are marked in many places by high-standing ridges that continue the traces of graben bounding faults on the plains adjacent to the VM. These fault-continuation ridges (FCR) are most prominent at Melas Labes and Candor Labes, where they form the boundaries between Ophir, Melas, and Candor Chasmae. FCR are as long as 100 km, and extend from the plains surfaces downward about 3-6 km in elevation. Available data suggests that FCR are fault zones cemented and hardened by groundwater deposits.

  19. A Field of Small Pitted Cones on the Floor of Coprates Chasma: Volcanism inside Valles Marineris

    NASA Astrophysics Data System (ADS)

    Hauber, E.; Broz, P.; Rossi, A. P.; Michael, G.

    2015-10-01

    We present observations of a field of >100 pitted cones and mounds situated on the floor of Coprates Chasma (part of Valles Marineris (VM); Fig. 1), which display similarities to terrestrial and martian scoria cones. If these cones are indeed volcanic in origin, they will significantly expand our knowledge about the morphometry of pyroclastic cones on Mars. Moreover, a magmatic origin, which would necessarily post-date the opening of the main VM troughs, would contribute to our understanding of the volcano-tectonic evolution of VM.

  20. Role of Clay Minerals in Long-Distance Transport of Landslides in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Watkins, J.; Ehlmann, B. L.; Yin, A.

    2014-12-01

    Long-runout (> 50 km) subaerial landslides are rare on Earth, but are common features episodically shaping Mars' Valles Marineris (VM) trough system over the past 3.5 billion years. They display two end-member morphologies: a thick-skinned inner zone, characterized by fault-bounded, rotated blocks near their source region, and a thin-skinned, exceptionally long-runout outer zone, characterized by thin sheets spreading over 10s of km across the trough floor. Four decades of studies on the latter have resulted in two main competing hypotheses to explain their long-distance transport: (1) movement of landslides over layers of trapped air or soft materials containing ice or snow, enabling basal lubrication, and (2) fluidization of landslide materials with or without the presence of water and volatiles. To address this issue, we examine the mineralogic composition of landslides across VM using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) near-infrared spectral data analysis coupled with detailed geologic mapping and morphometric analysis of satellite images. Our survey reveals a general correlation between transport distance, significant lateral spreading, and the presence of hydrated silicates among VM landslides. Given that smectite clay absorbs water into its layered crystal structure and can reduce the friction coefficient by a factor of three v. that of dry rocks, these results suggest that hydrated silicates played a decisive role in facilitating long-runout landslide transport in VM. We propose that, concurrent with downslope failure and sliding of broken trough-wall rock, frontal landslide masses overrode and entrained hydrated-silicate-bearing trough-floor deposits, lubricating the basal sliding zones and permitting the landslide outer zones to spread laterally while moving forward over the low-friction surface. The key participation of hydrated silicates in episodic, sustained landslide activity throughout the canyon implies that clay minerals, generated by water-rock interactions in the Noachian and Hesperian (4.1- 3.3 Ga), exert a long-lasting influence on geomorphic processes that shape the surface of the planet.

  1. Lithologic and Structural Control on Slope Morphology in the Valles Marineris

    NASA Technical Reports Server (NTRS)

    Patton, P. C.

    1985-01-01

    Throughout the Valles Marineris scarp morphology varies as a function of lithology, structure and scarp height. In addition lithology is an important control on permeability and the relative importance of spring sapping processes. Geomorphic mapping of distinct subareas can be used to define the characteristic scarp forms. Distinct morphologic zones defined on the basis of regional variations in lithology are described. Lithology and tectonic history are shown to be the two most important factors controlling slope development. Regional variation in scarp morphology can be correlated with the orientation and density of fracture systems; scarp height and the presence of rejuvenated fault scarps; and the thickness and degree of exposure of presumably less competent, more permeable, water saturated crated plateau material in the chasmata scarps.

  2. Correlations Between Textures and Infrared Spectra of the Martian Surface in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Ralston, S. J.; Wray, J. J.

    2013-12-01

    RALSTON, S. J., School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, sralston3@gatech.edu, WRAY, James, School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, jwray@eas.gatech.edu In the past few decades, a wealth of information has become available on the appearance and composition of the Martian surface. While some previous research has examined possible correlations between certain surface features and mineralogy (such as the hypothesized connection between Recurring Slope Lineae and perchlorate salts), little has yet been done to determine possible correlations between mineralogy and texture in less extraordinary circumstances. In this project, one hundred images taken from across the Valles Marineris region were examined both in infrared (obtained from the CRISM instrument aboard the Mars Reconnaissance Orbiter) and in visible-light images from the HiRISE camera. Spectra were obtained from regions of interest, focusing mainly on the identification of monohydrated and polyhydrated sulfates. Other materials were included in the imaging, including phyllosilicate clays, gypsum, and jarosite, although those materials proved less abundant than the sulfates. The areas from which the spectra were taken were then examined in visible-light wavelengths using HiRISE images to determine textural qualities. The focus of this research was on two particular textures, a 'reticulated' texture and a 'stepped texture,' hypothesized to correlate to monohydrated and polyhydrated sulfates, respectively. Results showed that over 55% of areas containing monohydrated sulfates also contained reticulate texture, whereas areas that contained other materials, such as polyhydrated sulfates and clays, had only a 2-8% correlation with reticulate texture. The stepped texture was shown to have no significant correlation to any one material, although other texture/mineral pairs did show some correlation. This presentation will cover the range of textures and mineralogy found throughout Valles Marineris.

  3. Structural development of Coprates Chasma and western Ophir Planum, Valles Marineris Rift, Mars

    NASA Technical Reports Server (NTRS)

    Schultz, Richard A.

    1991-01-01

    A portion of Valles Marineris was mapped in detail in order to clarify the dominant processes responsible for the formation of Coprates Chasma. New crater counts indicate that the caprock on western Ophir Planum plateau has a Late Hesperian crater age, whereas trough floor preserved in western Coprates Chasma has an Early to Late Hesperian crater age. Caprock on western Ophir Planum correlates in relative age with the Syria Planum Formation, and the caprock may overlie Lower Hesperian ridged plains material. Trough floor material in Coprates Chasma correlates in relative age with ridged plains material on the adjacent Lunae Planum and Coprates plateaus and represents a structurally coherent block displaced downward by normal faulting. The crater counts and detailed structural relationships demonstrate the commonly accepted view that Coprates Chasma occupies a graben. Formation of Coprates Chasma by keystone collapse of locally elevated topography is not supported by available topographic data, but a general association between the trough and volcanotectonic activity in the Tharsis region is considered to be a likely explanation for the trough forming stresses. Faulting on Ophir Planum appears related to the faulting that created the Coprates Chasma trough. The geology and structure of Coprates Chasma are comparable to those of other troughs such as Melas, Ius, and perhaps Candor chasmata, suggesting that these troughs may also have formed as grabens.

  4. Low H/L of initial and secondary landslides on Mars Valles Marineris floor

    NASA Astrophysics Data System (ADS)

    Sagi, H.; Fukuoka, H.

    2012-12-01

    The Mars Global Surveyer (MGS) has investigated the almost whole Martian topography with high resolution and its products are reflected in the Google Earth's martian option. This digital service provide huge opportunities to public to view the preserved landslide topography as well as to measure the parameters for landslide mobility such as average coefficient of friction (H/L), and apparent friction angle. Among those views, the Valles Marineris is the most landslide prone area and a lot of long runout gigantic landslides can be extracted along the tectonic cliff. Authors encouraged undergraduate students to measure this parameter as an exercise of introductory course of planetary science, especially of the gigantic initial landslides to compare with those of secondary landslides which looks like induced by subsequent triggers such as earthquake or metor impact. Preliminary results show that (1) The H/L values of the gigantic initial landslides are dependent on landslide volume as reported by previous studies; (2) secondary landslides of much less volumes generally have wide and thin spread features but much smaller friction like debris flows. Those characters imply that those landslides might have been induced in the landslide deposits of higher moisture content and/or runout on valley floor of highly saturated or shallow ground water table.

  5. Erosional development of bedrock spur and gully topography in the Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Patton, Peter C.

    1990-01-01

    Gully networks separated by resistant bedrock spurs are a common erosional feature along the escarpments that border the Valles Marineris. The resistant spur topography is best developed where the base of the slope is truncated by linear scarps interpreted as fault scarps. Regional variations in slope morphology imply that spur and gully topography undergoes a systematic progressive degradation through time associated with the erosional destruction of the basal fault scarps. The comparative morphometry of the divide networks indicates that the density of the spur networks and the number of first-order unbranched spurs decreases as the basal slope break becomes more sinuous. Abstraction of the spurs occurs through regolith storage in adjacent gullies at the slope base and the most degraded slope forms are entirely buried in talus. The basal fault scarps apparently control regolith transport by allowing debris to drain from the slope. As these basal scarps decay the slope base becomes increasingly sinuous and the slopes become transport limited. Dry mass-wasting may be the most important process acting on these slopes where a continually lowered base level is required to maintain the spur topography. In contrast to the Martian slopes, range front fault escarpments in the western U.S. show no systematic trend in spur network geometry as they are eroded. These weathering limited slopes are controlled by the more efficient removal of regolith through fluvial processes which rapidly create quasi-equilibrium drainage networks.

  6. Acidic Alteration Environments at Valles Marineris, Noctis Labyrinthus and Mawrth Vallis

    NASA Astrophysics Data System (ADS)

    Bishop, Janice L.; Weitz, Catherine M.; Flahaut, Jessica; Gross, Christoph; Horgan, Briony

    2015-04-01

    Unique surface materials have been discovered at Valles Marineris, Noctis Labyrinthus, Mawrth Vallis, and elsewhere that have CRISM features distinct from those of any known minerals. Typically these unusual sites are found in light-toned outcrops or interior layered deposits associated with phyllosilicates and/or sulfates. We term these units "doublet" materials because they exhibit a doublet absorption in CRISM spectra between 2.2 and 2.3 µm. We are investigating the spectral signatures of these outcrops compared to lab spectra of minerals, mixtures and alteration products. We're also evaluating the stratigraphy of these unique alteration phases compared with neighboring phyllosilicate and sulfate units. A similar 2.2-2.3 µm doublet has been observed in spectra taken of acid altered clays produced in the laboratory. The band centers and relative intensities of these Martian doublet features vary greatly suggesting that a process such as acid weathering could be acting on OH-bearing minerals to produce altered phases that differ depending on the type of substrate, water/rock ratio, solution chemistry, and duration of aqueous processes. Because these unique materials occur in many regions across a range of times on Mars, acidic alteration may have been a key process at local and regional scales throughout Martian geologic history. Constraining the types of acidic alteration that have taken place on Mars will assist in defining the aqueous geochemistry at these sites.

  7. Diagenetic Layers in the Upper Walls of Valles Marineris, Mars: Evidence for Drastic Climate Change Since the Mid-Hesperian

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.; Fuks, Kelly H.; Murchie, Scott

    1995-01-01

    A packet of relatively resistant layers, totaling approx. 400 m thickness, is present at the tops of the chasma walls throughout Valles Marineris. The packet consists of an upper dark layer (approx. 50 m thick), a central bright layer (approx. 250 m thick), and a lower dark layer (approx. 100 m thick). The packet appears continuous and of nearly constant thickness and depth below ground surface over the whole Valles system (4000 km E-W, 800 km N-S), independent of elevation (3-10 km) and age of plateau surface (Noachian through upper Hesperian). The packet continues undisturbed beneath the boundary between surface units of Noachian and Hesperian ages, and continues undisturbed beneath impact craters transected by chasma walls. These attributes are not consistent with layer formation by volcanic or sedimentary deposition, and are consistent with layer formation in situ, i.e., by diagenesis, during or after upper Hesperian time. Diagenesis seems to require the action of aqueous solutions in the near subsurface, which are not now stable in the Valles Marineris area. To permit the stability of aqueous solutions, Mars must have had a fairly dense atmosphere, greater than or equal to 1 bar CO2, when the layers formed. Obliquity variations appear to be incapable of producing such a massive atmosphere so late in Mars' history.

  8. Numerical slope stability simulations of chasma walls in Valles Marineris/Mars using a distinct element method (dem).

    NASA Astrophysics Data System (ADS)

    Imre, B.

    2003-04-01

    NUMERICAL SLOPE STABILITY SIMULATIONS OF CHASMA WALLS IN VALLES MARINERIS/MARS USING A DISTINCT ELEMENT METHOD (DEM). B. Imre (1) (1) German Aerospace Center, Berlin Adlershof, bernd.imre@gmx.net The 8- to 10-km depths of Valles Marineris (VM) offer excellent views into the upper Martian crust. Layering, fracturing, lithology, stratigraphy and the content of volatiles have influenced the evolution of the Valles Marineris wallslopes. But these parameters also reflect the development of VM and its wall slopes. The scope of this work is to gain understanding in these parameters by back-simulating the development of wall slopes. For that purpose, the two dimensional Particle Flow Code PFC2D has been chosen (ITASCA, version 2.00-103). PFC2D is a distinct element code for numerical modelling of movements and interactions of assemblies of arbitrarily sized circular particles. Particles may be bonded together to represent a solid material. Movements of particles are unlimited. That is of importance because results of open systems with numerous unknown variables are non-unique and therefore highly path dependent. This DEM allows the simulation of whole development paths of VM walls what makes confirmation of the model more complete (e.g. Oreskes et al., Science 263, 1994). To reduce the number of unknown variables a proper (that means as simple as possible) field-site had to be selected. The northern wall of eastern Candor Chasma has been chosen. This wall is up to 8-km high and represents a significant outcrop of the upper Martian crust. It is quite uncomplex, well-aligned and of simple morphology. Currently the work on the model is at the stage of performing the parameter study. Results will be presented via poster by the EGS-Meeting.

  9. The Confluence of Gangis and Eos Chasmas (5-12 deg S, 31-41 deg W): Geologic, Hydrologic, and Exobiologic Considerations for Landing Site at the East End of Valles Marineris

    NASA Technical Reports Server (NTRS)

    George, J. A.; Clifford, S. M.

    1999-01-01

    Over its 3,500 km length, Valles Marineris exhibits an enormous range of geologic and environmental diversity. At its western end, the canyon is dominated by the tectonic complex of Noctis Labyrinthus; while in the east it grades into an extensive region of chaos where scoured channels and streamlined islands provide evidence of catastrophic floods that spilled into the northern plains. In the central portion of the system, debris derived from the massive interior layered deposits of Candor and Ophir Chasmas spills into the central trough. In other areas, 6 km-deep exposures of Hesperian and Noachian-age canyon wall stratigraphy have collapsed in massive landslides that extend many tens of kilometers across the canyon floor. Ejecta from interior craters, aeolian sediments, and possible volcanics emanating from structurally controlled vents along the base of the scarps, further contribute to the canyon's geologic complexity. Following the initial rifting that gave birth to Valles Marineris, water appears to have been a principal agent in the canyon's geomorphic development an agent whose significance is given added weight by its potential role in both sustaining and preserving evidence of past life. In this regard, the interior layered deposits of Candor, Ophir, and Hebes Chasmas, have been identified as possible lucustrine sediments that may have been laid down in long-standing ice-covered lakes. The potential survival and growth of native organisms in such an environment, or in the aquifers whose disruption gave birth to the chaotic terrain and outflow channels to the north and east of the canyon, raises the possibility that fossil indicators of life may be present in the local sediment and rock. Because of the enormous distances over which these diverse environments occur, identifying a single landing site that maximizes the opportunity for scientific return is not a simple task. However, given the fluvial history and narrow geometry of the canyon, the presence of a single exit at its eastern end provides an opportunity for sampling that appears unequaled elsewhere in the system.

  10. Valles Marineris as a Cryokarstic Structure Formed by a Giant Dyke System: Support From New Analogue Experiments

    NASA Astrophysics Data System (ADS)

    Ozeren, M. S.; Sengor, A. M. C.; Acar, D.; Ülgen, S. C.; Onsel, I. E.

    2014-12-01

    Valles Marineris is the most significant near-linear depression on Mars. It is some 4000 km long, up to about 200 km wide and some 7 km deep. Although its margins look parallel at first sight, the entire structure has a long spindle shape with significant enlargement in its middle (Melas Chasma) caused by cuspate slope retreat mechanisms. Farther to its north is Hebes Chasma which is an entirely closed depression with a more pronounced spindle shape. Tithonium Chasma is a parallel, but much narrower depression to its northeast. All these chasmae have axes parallel with one another and such structures occur nowhere else on Mars. A scabland surface exists to the east of the Valles Marineris and the causative water mass seems to have issued from it. The great resemblance of these chasmae on mars to poljes in the karstic regions on earth have led us to assume that they owed their existence to dissolution of rock layers underlying them. We assumed that the dissolving layer consisted of water ice forming substantial layers, in fact entirely frozen seas of several km depth. We have simulated this geometry by using bentonite and flour layers (in different experiments) overlying layers of ice in which a resistant coil was used to simulate a dyke. We used different thicknesses of bentonite and flour overlying ice layers again of various thicknesses. The flour seems to simulate the Martian crust better because on Mars, g is only about 3/8ths of its value on Earth, so (for equal crustal density) the depth to which the cohesion term C remains important in the Mohr-Coulomb shear failure criterion is about 8/3 times greater. As examples we show two of those experiments in which both the rock analogue and ice layers were of 1.5 cm. thick. Perfect analogues of the Valles Marineris formed above the dyke analogue thermal source complete with the near-linear structure, overall flat spindle shape, cuspate margins, a central ridge, parallel side faults, parallel depressions resembling the Tithonium Chasma. When water was allowed to drain from the beginning, closed depressions formed that have an amazing resemblance to Hebes chasma. We postulate that the entire system of chasmae here discussed formed atop a major dyke swarm some 4000 km length, not dissimilar to the 3500 km long Mesoproterozoic (Ectasian) dyke swarm disrupting the Canadian Shield.

  11. Geometric comparison of deep-seated gravitational spereading features on Mars (Coprates Chasma, Valles Marineris) and Earth (Ornak, Tatra Mountains)

    NASA Astrophysics Data System (ADS)

    Kromuszczy?ska, O.; Mège, D.

    2014-04-01

    Uphill-facing normal faults scarps and crestal grabens, which are characteristic of deep-seated gravitational spreading (DSGS) of topographic ridges, are described in Coprates Chasma in Valles Marineris, Mars, and Ornak ridge and compared. The vertical offset of normal faults in the Martian instances varies from 40 to 1000 meters, with an average of 300 meters. The terrestrial faults offset is between few teens of centimeters up to 34 meters with an average of 10 meters. The values of horizontal displacement in Coprates Chasma vary from 10 to 680 meters, and at Ornak are in a range between 1 and 20 meters. Such difference corresponds with the difference of ridges scale and is due to the topographic gradient which is one order of magnitude higher on Mars than on Earth.

  12. Identification and spatial distribution of light-toned deposits enriched in Al-phyllosilicates on the plateaus around Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Le Deit, L.; Flahaut, J.; Quantin, C.; Allemand, P.

    2009-12-01

    The plateaus around Valles Marineris consist in series of mafic rocks suggested to be flood basalts (McEwen et al., 1998), lavas interbedded with sediments (Malin and Edgett, 2000), layered intrusive rocks (Williams et al., 2003), or lava flows dated from the Noachian to the late Hesperian epochs (Scott and Carr, 1978). Recent studies show the occurrence of light layered deposits of hundred meters thick cropping out on plateaus near Ius Chasma, Melas Chasma, Candor Chasma, Juventae Chasma and Ganges Chasma deposited during the Hesperian epoch by fluvio-lacustrine processes (Weitz et al., 2009), or by air-fall processes (Le Deit et al., 2009). These layered deposits are enriched in hydrated minerals including opaline silica (Milliken et al., 2008), hydroxylated ferric sulfates (Bishop et al., 2009), and possibly Al-rich phyllosilicates (Le Deit et al., 2009). We identified another type of formation corresponding to light-toned massive deposits cropping out around Valles Marineris. It appears that these light-toned deposits are associated to bright, rough, and highly cratered terrains, located beneath a dark and thin capping unit. Previous studies report the occurrence of phyllosilicates on few locations around Valles Marineris based on OMEGA data analyses (Gondet et al., 2007; Carter et al., 2009). The analysis of CRISM data show that the light-toned deposits are associated with spectra displaying absorption bands at 1.4 ?m, 1.9 ?m, and a narrow band at 2.2 ?m. These spectral characteristics are consistent with the presence of Al-rich phyllosilicates such as montmorillonite, or illite in the light-toned deposits. They constitute dozens of outcrops located on the plateaus south and east of Coprates Chasma and Capri Chasma, and west of Ganges Chasma. All outcrops investigated so far are present over Noachian terrains mapped as the unit Npl2 by Scott and Tanaka (1986), and Witbeck et al. (1991). These light-toned deposits could result from in situ aqueous alteration of Noachian basaltic plateaus during or after the Noachian epoch. We also identified Fe/Mg-rich phyllosilicates that are commonly found in the southern highland Noachian terrains (Mustard et al., 2008). They are located in central peaks, rims and ejecta of impact craters on plateaus, suggesting excavation of old buried layers. The deposits located around Valles Marineris are characterized by a wide variety of hydrated minerals that registered the evolution of the environmental conditions from the Noachian to the late Hesperian epochs. Further investigations are ongoing to determine their global spatial distribution and their stratigraphical relationships in order to better constrain the geological and climatic history of the region of Valles Marineris.

  13. A New Method for High-Resolution Apparent Thermal Inertia Mapping of Mars: Application to Valles Marineris

    NASA Astrophysics Data System (ADS)

    Kubiak, M.; Mège, D.; Gurgurewicz, J.; Ci??ela, J.

    2014-12-01

    The minerals absorb and reflect thermal infrared (TIR) light of the different wavelengths depending on their composition and structure. Thus, every rock absorbs and reflects different wavelengths in TIR and has its own spectral signature. The TIR images are used in the thermal inertia mapping and in its approximation called apparent thermal inertia (ATI). We present the methodology and the high-resolution apparent thermal inertia maps for selected parts of Valles Marineris (Mars). ATI was calculated from surface albedo (A) and diurnal temperature difference (?T) following the equation: ATI = (1 - A) / ?T. Albedo was computed by dividing reflected radiation (IR) by incident radiation (II): A = IR / II. After introducing: II = F • cosIA, where F stands for solar constant and IA for incident angle (°), it develops to: A = IR / (F • cosIA). This formula allows us to calculate A on a horizontal surface. Calculating A on an inclined surface requires corrections of IA against relief characteristics (slopes, aspects): IAC = (IA - arctan(tans • cos(e + t • 15° - 180°))), where s is slope (°), e - aspect (°) and t - local solar time (h). A correction was made also for ?T. The calibration process was more complex because it involved changes in incident radiation (II) over a given time interval (?T = T13:00 - T6:00). II is a function of: Martian tilt, eccentricity, perihelium longitude, solar longitude (Ls, in °), latitude (?, in °), local solar time and relief characteristics. Total II, integrated over the time interval, can be calculated following the equation [1]. The results were compared to the existing thermal inertia maps of Mars.

  14. Study of phyllosilicates and carbonates from the Capri Chasma region of Valles Marineris on Mars based on Mars Reconnaissance Orbiter-Compact Reconnaissance Imaging Spectrometer for Mars (MRO-CRISM) observations

    NASA Astrophysics Data System (ADS)

    Jain, Nirmala; Chauhan, Prakash

    2015-04-01

    Spectral reflectance data from the MRO-CRISM (Mars Reconnaissance Orbiter-Compact Reconnaissance Imaging Spectrometer for Mars) of Capri Chasma, a large canyon within Valles Marineris on Mars, have been studied. Results of this analysis reveal the presence of minerals, such as, phyllosilicates (illite, smectite (montmorillonite)) and carbonates (ankerite and manganocalcite). These minerals hint of the aqueous history of Noachian time on Mars. Phyllosilicates are products of chemical weathering of igneous rocks, whereas carbonates could have formed from local aqueous alteration of olivine and other igneous minerals. Four different locations within the Capri Chasma region were studied for spectral reflectance based mineral detection. The study area also shows the spectral signatures of iron-bearing minerals, e.g. olivine with carbonate, indicating partial weathering of parent rocks primarily rich in ferrous mineral. The present study shows that the minerals of Capri Chasma are characterized by the presence of prominent spectral absorption features at 2.31 ?m, 2.33 ?m, 2.22 ?m, 2.48 ?m and 2.52 ?m wavelength regions, indicating the existence of hydrous minerals, i.e., carbonates and phyllosilicates. The occurrence of carbonates and phyllosilicates in the study area suggests the presence of alkaline environment during the period of their formation. Results of the study are important to understand the formation processes of these mineral assemblages on Mars, which may help in understanding the evolutionary history of the planet.

  15. Valles Marineris dune fields as compared with other martian populations: Diversity of dune compositions, morphologies, and thermophysical properties

    NASA Astrophysics Data System (ADS)

    Chojnacki, Matthew; Burr, Devon M.; Moersch, Jeffrey E.

    2014-02-01

    Planetary dune field properties and their bulk bedform morphologies relate to regional wind patterns, sediment supply, climate, and topography. On Mars, major occurrences of spatially contiguous low-albedo sand dunes are primarily found in three major topographic settings: impact craters, high-latitude basins, and linear troughs or valleys, the largest being the Valles Marineris (VM) rift system. As one of the primary present day martian sediment sinks, VM holds nearly a third of the non-polar dune area on Mars. Moreover, VM differs from other regions due to its unusual geologic, topographic, and atmospheric setting. Herein, we test the overarching hypothesis that VM dune fields are compositionally, morphologically, and thermophysically distinct from other low- and mid-latitude (50°N-50°S latitude) dune fields. Topographic measurements of dune fields and their underlying terrains indicate slopes, roughnesses, and reliefs to be notably greater for those in VM. Variable VM dune morphologies are shown with topographically-related duneforms (climbing, falling, and echo dunes) located among spur-and-gully wall, landslide, and chaotic terrains, contrasting most martian dunes found in more topographically benign locations (e.g., craters, basins). VM dune fields superposed on Late Amazonian landslides are constrained to have formed and/or migrated over >10s of kilometers in the last 50 My to 1 Gy. Diversity of detected dune sand compositions, including unaltered ultramafic minerals and glasses (e.g., high and low-calcium pyroxene, olivine, Fe-bearing glass), and alteration products (hydrated sulfates, weathered Fe-bearing glass), is more pronounced in VM. Observations show heterogeneous sand compositions exist at the regional-, basinal-, dune field-, and dune-scales. Although not substantially greater than elsewhere, unambiguous evidence for recent dune activity in VM is indicated from pairs of high-resolution images that include: dune deflation, dune migration, slip face modification (e.g., alcoves), and ripple modification or migration, at varying scales (10s-100s m2). We conclude that VM dune fields are qualitatively and quantitatively distinct from other low- and mid-latitude dune fields, most readily attributable to the rift's unusual setting. Moreover, results imply dune field properties and aeolian processes on Mars can be largely influenced by regional environment, which may have their own distinctive set of boundary conditions, rather than a globally homogenous collection of aeolian sediment and bedforms.

  16. One million cubic kilometers of fossil ice in Valles Marineris: Relicts of a 3.5 Gy old glacial landsystem along the Martian equator

    NASA Astrophysics Data System (ADS)

    Gourronc, Marine; Bourgeois, Olivier; Mège, Daniel; Pochat, Stéphane; Bultel, Benjamin; Massé, Marion; Le Deit, Laetitia; Le Mouélic, Stéphane; Mercier, Denis

    2014-01-01

    Self-consistent landform assemblages suggest that Valles Marineris, the giant valley system that stretches along the Martian equator, was entirely glaciated during Late Noachian to Early Hesperian times and still contains huge volumes of fossil ice. Some of these glacial landform assemblages are illustrated here, with representative examples selected in three regions: Ius Chasma, Central Candor Chasma and the junction between Coprates Chasma and Capri Chasma. A morphological boundary separating an upper spur-and-gully morphology from a smooth basal escarpment has been spectacularly preserved along valley walls throughout Valles Marineris. The boundary winds around topographic obstacles and displays long-wavelength variations in elevation. It is associated with lateral benches, hanging valleys and truncated spurs. Comparisons with terrestrial analogs indicate that it is most reasonably interpreted as a glacial trimline. Chasma floors are covered by various kinds of terrains, including hummocky terrains, platy terrains, lateral banks, layered benches and a draping mantle. Landforms in these terrains and their spatial relationship with the interpreted trimline suggest that they correspond to various disintegration stages of an ancient glacial fill, currently protected by a superficial cover of ablation till. Altogether, these landforms and terrains compose a full glacial landsystem with wet-based glaciers that were able to flow and slide over their beds. It was most probably fed by ice accumulating at low elevations directly from the atmosphere onto valley floors and walls, with only minor contributions from tributary glaciers flowing down from higher elevations. Similar fossil glacial landsystems dating back from the early Martian history are to be expected in many other low-latitude troughs such as chasmata, chaos, valleys, impact craters and other basins.

  17. One million cubic kilometers of fossil ice in Valles Marineris: relicts of a 3.5 Gy old glacial landsystem along the Martian equator

    NASA Astrophysics Data System (ADS)

    Bourgeois, O.; Gourronc, M.; Mège, D.; Pochat, S.; Bultel, B.; Massé, M.; Le Deit, L.; Le Mouélic, S.; Mercier, D.

    2013-12-01

    Self-consistent landform assemblages suggest that Valles Marineris, the giant valley system that stretches along the Martian equator, was entirely glaciated during Late Noachian to Early Hesperian times and still contains huge volumes of fossil ice. Some of these glacial landforms assemblages are illustrated here. A morphological boundary separating an upper spur-and-gully morphology from a smooth basal escarpment has been spectacularly preserved along valley walls throughout Valles Marineris. The boundary winds around topographic obstacles and displays long-wavelength variations in elevation. It is associated with lateral benches, hanging valleys and truncated spurs. Comparisons with terrestrial analogues indicate that it is most reasonably interpreted as a glacial trimline. Chasma floors are covered by various kinds of terrains, including hummocky terrains, platy terrains, lateral banks, layered benches and a draping mantle. Landforms in these terrains and their spatial relationship with the interpreted trimline suggest that they correspond to various disintegration stages of an ancient glacial fill, currently protected by a superficial cover of ablation till. Altogether, these landforms and terrains compose a full glacial landsystem with wet-based glaciers that were able to flow and slide over their beds. It was most probably fed by ice accumulating at low elevations directly from the atmosphere onto valley floors and walls, with only minor contributions from tributary glaciers flowing down from higher elevations. Similar fossil glacial landsystems dating back from the early Martian history are to be expected in many other low-latitude troughs such as chasmata, chaos, valleys, impact craters and other basins.

  18. Valles Marineris, Mars: High-Resolution Digital Terrain Model on the basis of Mars-Express HRSC data

    NASA Astrophysics Data System (ADS)

    Dumke, A.; Spiegel, M.; van Gasselt, S.; Neukum, G.

    2009-04-01

    Introduction: Since December 2003, the European Space Agency's (ESA) Mars Express (MEX) orbiter has been investigating Mars. The High Resolution Stereo Camera (HRSC), one of the scientific experiments onboard MEX, is a pushbroom stereo color scanning instrument with nine line detectors, each equipped with 5176 CCD sensor elements. Five CCD lines operate with panchromatic filters and four lines with red, green, blue and infrared filters at different observation angles [1]. MEX has a highly elliptical near-polar orbit and reaches a distance of 270 km at periapsis. Ground resolution of image data predominantly varies with respect to spacecraft altitude and the chosen macro-pixel format. Usually, although not exclusively, the nadir channel provides full resolution of up to 10 m per pixel. Stereo-, photometry and color channels generally have a coarser resolution. One of the goals for MEX HRSC is to cover Mars globally in color and stereoscopically at high-resolution. So far, HRSC has covered almost half of the surface of Mars at a resolution better than 20 meters per pixel. Such data are utilized to derive high resolution digital terrain models (DTM), ortho-image mosaics and additionally higher-level 3D data products such as 3D views. Standardized high-resolution single-strip digital terrain models (using improved orientation data) have been derived at the German Aerospace Center (DLR) in Berlin-Adlershof [2]. Those datasets, i.e. high-resolution digital terrain models as well as ortho-image data, are distributed as Vicar image files (http://www-mipl.jpl.nasa.gov/external/vicar.html) via the HRSCview web-interface [3], accessible at http://hrscview.fu-berlin.de. A systematic processing workflow is described in detail in [4,5]. In consideration of the scientific interest, the processing of the Valles Marineris region will be discussed in this paper. The DTM mosaic was derived from 82 HRSC orbits at approximately -22° S to 1° N and 250° to 311° E. Methods: Apart from the DTM quality, image mosaicking also depends on the quality of exterior orientation data, and in order to generate high resolution DTMs and ortho-images, these data have to be corrected. For this purpose, new exterior and interior orientation data, based on tie-point matching and bundle adjustment have been used. The automated determination of tie points by software provided by the Leibniz Universität Hannover [6] are used as input in the bundle adjustment, provided by the Technische Universität München and Freie Universität Berlin. The bundle adjustment approach for photogrammetric point determination with a three-line camera is a least squares adjustment based on the well known collinearity equations. The approach estimates the parameters of the exterior orientation only at a few selected image lines. Because of Doppler shift measurements to estimate the position of the orbiter there are systematic effects in the observed exterior orientation. To model these effects in the bundle adjustment, additional observation equations for bias (offset) and drift have to be introduced. To use the MOLA DTM as control information, the least squares adjustment has to be extended with an additional observation equation for each HRSC point. These observations describe a relation between the MOLA DTM and these HRSC points. This approach is described in more detail in [7,8]. Derivation of DTMs and ortho-image mosaics are basically performed using software developed at the German Aerospace Center (DLR), Berlin and is using the Vicar environment developed at JPL. For the DTM derivation, the main processing tasks are first a prerectification of image data using the global MOLA-based DTM, then a least-squares area-based matching between nadir and the other channels (stereo and photometry) in a pyramidal approach and finally, DTM raster generation. Iterative low-pass image filtering (Gauss and mean filtering) is applied in order to improve the image matching process by increasing the amount and quality of object points and in order to reduce possible misdetections caused by i

  19. UNCORRECTEDPROOF 2 Valles Marineris landslides: Evidence for a

    E-print Network

    Montgomery, David R.

    consistent with the intact 15 strength of evaporites or other weak sedimentary rock defines an upper bound being composed of relatively weak 20 materials, such as potentially frozen evaporites and/or mixturesstratified with evaporites and overlain by lava flows 42(Blaney and McChord, 1995; Forsythe and Zimbelman

  20. Complex Floor Deposits Within Western Ganges Chasma, Valles Marineris

    NASA Technical Reports Server (NTRS)

    1997-01-01

    On October 26, 1997, MOC took this image of Mars 10 minutes after its closest approach to the planet (1:46 AM PST). The view shows the floor of western Ganges Chasma (7.8oS 51.8oW), covering an area 2.6 km (1.6 miles) wide by 45.4 km (28.2 miles) long at a resolution of 5 by 7.4 meters (16.4 by 24.3 feet) per picture element. The local time on Mars when the picture was taken was 4:35 PM.

    The center image (available at higher resolution as PIA01028) shows the northern portion of the area inscribed in the left image. The right image (PIA01029) shows the southern portion.

    Launched on November 7, 1996, Mars Global Surveyor entered Mars orbit on Thursday, September 11, 1997. The original mission plan called for using friction with the planet's atmosphere to reduce the orbital energy, leading to a two-year mapping mission from close, circular orbit (beginning in March 1998). Owing to difficulties with one of the two solar panels, aerobraking was suspended in mid-October and resumed in November 8. Many of the original objectives of the mission, and in particular those of the camera, are likely to be accomplished as the mission progresses.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  1. Auqakuh Valles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 7 June 2002) The Science This ancient sinuous river channel, located near 30o N, 299o W (61o E), was likely carved by water early in Mars history. Auqakuh Valles cuts through a remarkable series of rock layers that were deposited and then subsequently eroded. This change from conditions favoring deposition to those favoring erosion indicates that the environment of this region has changed significantly over time. In addition, the different rock layers seen in this image vary in hardness, with some being relatively soft and easily eroded, whereas others are harder and resistant. These differences imply that these layers vary in their composition, physical properties, and/or degree of cementation, and again suggest that major changes have occurred during the history of this region. Similar differences occur throughout the southwest U.S., where hard rock layers, such as the limestones and sandstones in the Grand Canyon, form resistant cliffs, whereas softer mudstones are easily eroded to form broad slopes. The Martian layers, such as the smooth, dark-toned mesas visible in numerous places to the right (east) of the channel, were once continuous across the region. As these layers have eroded, they have produced a wide array of textures, from smooth surfaces, to knobby terrains, to the unusual lobate patterns seen in the upper right of the image. The most recent activity in the region appears to be the formation of mega-ripples by the wind. These ripples, spaced approximately 75 m apart, form perpendicular to the wind direction, and can be seen following the pattern of the channel floor as it curves through this region. This pattern shows that even this relatively small channel, which varies in width from about 500 to 750 m throughout this image, acts to funnel the wind down the channel. The Story Auqakuh Vallis, an ancient river channel that winds its way down the center of this image, is the 'fossil' remains of an earlier, probably more watery time in Martian history. Now, you might think that Auqakuh has something to do with Aqua, the Latin word for water. Instead, Auqakuh is the word for Mars in the Quechuan language of the Incan Empire that once stretched across vast portions of South America. This Inca-honoring river channel cuts through a remarkable series of rock layers that expose a history of climate change in the region. The coarse, rugged, and wildly textured terrain was created as rock layers were first deposited, then eroded over time. Some of the rock layers are soft and easily eroded, while others are clearly harder and more resistant. From these differences, geologists can tell that the layers are made up of different materials, have different physical characteristics, and are either loosely or strongly cemented together. That suggests major environmental changes over time as well, since different kinds of rocks form under different conditions. Similar differences in rock layers occur throughout the Southwest of the United States. The next time you're visiting the Grand Canyon or hiking in similar terrain, notice where hard rock layers, such as limestones and sandstones, form resistant cliffs, whereas softer mudstones are easily eroded to form broad slopes along the canyon. Just in case the river channel in the above image looks more like a raised vein rather than a hollowed out channel, try looking at the half-circle depression on the left-hand side of the image, about a third of the way up. The bright features on the upper half streak down toward the bottom of the bowl. Once you focus on this for a while, your brain figures out that the channel must be depressed as well. Now that you can see that the channel cuts into the surface, click on the image for a closer look at the bottom of the channel. Mega-ripples about 82 yards apart line the channel floor as it curves through the region. This pattern shows that even this relatively small channel, which varies from about one-third to a half of a mile in width, funnels the wind down its curving length, creating per

  2. Hubble's Look at Mars Shows Canyon Dust Storm, Cloudy Conditions for Pathfinder Landing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Hubble Space Telescope images of Mars, taken on June 27, 1997, reveal a significant dust storm which fills much of the Valles Marineris canyon system and extends into Xanthe Terra, about 600 miles (1000 kilometers) south of the landing site.

    It is difficult to predict the evolution of this storm and whether it will affect the Pathfinder observations.

    The pictures were taken in order to monitor the site in Ares Vallis where the Pathfinder spacecraft will land on July 4.

    The two images of Mars at the top of the figure are Hubble observations from June 27 (right) and May 17 (left). Visual comparison of these two images clearly shows the dust storm between 5 and 7 o'clock and about 2/3 of the way from the center of the planet's disk to the southern edge of the June image.

    The digital data were projected to form the map of the equatorial portion of the planet which is shown in the bottom portion of the figure. The green cross marks the location of the Pathfinder landing site, and the yellowish ribbon of dust which runs horizontally across the bottom of the map traces the location of Valles Marineris, a system of canyons which would stretch from Los Angeles to New York if placed on Earth.

    Most of the dust is confined within the canyons, which are up to 5-8 kilometers deep. The thickness of the dust cloud near the eastern end of the storm is similar to that observed by Viking lander 1 during the first of the two 1977 global dust storms which it studied.

    Other interesting features appear in this image. The northwestern portions of the planet are enveloped in unusually thick water ice clouds, similar to cirrus clouds on Earth; some clouds extend as far as Lunae Planum, the slightly darker region about halfway from the center to the left side of the map. The dark spot near the terminator (boundary between day and night) at about 9:00 in the June 27 planet image is Ascraeus Mons, a 27 kilometer high volcano, protruding through the clouds.

    The remnant north polar cap, composed of water ice, is at the top of the May and June images, and a bluish south polar hood, composed of water ice clouds, is seen along the southern edge. Because the planet's axis is tipped towards us during this season, we cannot see the south polar cap, which is in winter darkness.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  3. Grand Canyon

    Atmospheric Science Data Center

    2014-05-15

    article title:  The Grand Canyon     View Larger Image Northern Arizona and the Grand Canyon are captured in this pair of Multi-angle Imaging SpectroRadiometer ... formats available at JPL December 31, 2000 - Grand Canyon and Lake Powell. project:  MISR ...

  4. Human Exploration of Mars at Valles Marineris: The Past, Present, and Future of Life on Mars

    NASA Astrophysics Data System (ADS)

    Mojarro, A.; Ruvkun, G.; Zuber, M. T.; Carr, C. E.

    2015-10-01

    ROIs conceivable of harboring extant life at RSL sites, preserved microfossils beneath sedimentary deposits or biosignatures within impact glasses. Potentially exploitable aquifers and favorable environmental conditions for human habitation.

  5. Mobility and topographic effects for large Valles Marineris landslides on Mars

    E-print Network

    Lucas, Antoine

    (landslides, debris flows, gullies. . .) were identified on Mars [Lucchitta, 1979]. Martian granular flows may. As experimental and numerical models represent a huge simplification of natural processes, several parameters are expected to affect the modeled runouts as grain size and shape effects (M. Frank and P. W. Cleary, Three

  6. Kasei Valles

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 21 May 2003

    Just a small part of the huge Kasei Valles outflow channel is shown in this THEMIS visible image. Still, the awesome erosive power of the water that once flowed through this channel is evident. The different erosional levels of the channel indicate that it is likely that water flowed at several levels for some time. Today the area is covered by a layer of fine martian dust. The dark streaks seen on the cliff faces are the result of dust avalanches which have exposed the underlying rock.

    Image information: VIS instrument. Latitude 24.9, Longitude 287.4 East (72.6) 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.

  7. Hot Canyon

    ScienceCinema

    None

    2013-03-01

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  8. Hot Canyon

    SciTech Connect

    2012-01-01

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  9. Vallis Marineris Mouth as the Best Location for Exploration Zone (EZ)

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2015-10-01

    The mouth of Vallis Marineris is a particularly interesting location where the widest rock varieties could be expected. The Vallis crosses chaotic terrains and equatorial zone where water ice could be discovered. Pathfinder and Viking were nearby.

  10. The Valles natural analogue project

    SciTech Connect

    Stockman, H.; Krumhansl, J.; Ho, C.; McConnell, V.

    1994-12-01

    The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a highlevel waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, X-ray diffraction; and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and {sup 39}Ar/{sup 4O} isotopic composition. Overall,the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 meters of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks.

  11. Seismic expression of Late Quaternary Banda submarine canyon and fan offshore northern Baja California

    SciTech Connect

    Legg, M.R.

    1987-05-01

    High-resolution seismic reflection profiles obtained throughout the inner California continental borderland offshore northwestern Baja California, Mexico, show the presence of numerous modern submarine canyons and associated fans. One set of these, the Banda submarine canyon/fan, is of relatively recent origin, as demonstrated by onlap of the basal fan sediments against an acoustically transparent, presumably hemipelagic deposit. Late Quaternary sedimentation rates inferred from isotopically dated piston core samples place the age of the postulated hemipelagic unit at approximately 650,000 years ago. The Banda submarine canyon heads within the Bahia Todos Santo and passes through a narrow gorge between Punta Banda and Islas Todos Santos. It is proposed that this submarine canyon and fan system formed entirely during late Quaternary time, following the breach of the Punta Banda ridge during a late Pleistocene high sea level stand. The presence of an ancient, buried channel exiting to the north out of Bahia Todos Santos probably marks the head of an earlier submarine canyon which acted as the conduit of clastic sediments from Valle Maneadero to the deep borderland basins. The now active Banda submarine canyon pirated the supply of terrigenous clastics from this older canyon. The active Agua Blanca fault zone cuts across the head of Banda submarine canyon, suggesting that tectonic movements may have played a role in the development of the Banda submarine canyon and fan system.

  12. La Jolla Canyon and Scripps Canyon Bibliography

    E-print Network

    Brueggeman, Peter

    2009-01-01

    Rock samples from Scripps Canyon indicate that physical and chemical weatheringchemical weathering commonly extends less than one centimeter from surfaces exposed to the sea, and several freshly collected rock

  13. Marte Valles Crater 'Island'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    10 April 2004 Marte Valles is an outflow channel system that straddles 180oW longitude between the region south of Cerberus and far northwestern Amazonis. The floor of the Marte valleys have enigmatic platy flow features that some argue are formed by lava, others suggest they are remnants of mud flows. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an island created in the middle of the main Marte Valles channel as fluid---whether lava or mud---flowed past two older meteor impact craters. The craters are located near 21.5oN, 175.3oW. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

  14. Central Valles Marineris: uncontrolled Mars Global Surveyor (MGS) Mars Orbital Camera (MOC) digital context photomosaic (250 megapixel resolution)

    USGS Publications Warehouse

    Noreen, Eric

    2000-01-01

    These images were processed from a raw format using Integrated Software for Images and Spectrometers (ISIS) to perform radiometric corrections and projection. All the images were projected in sinusoidal using a center longitude of 70 degrees. There are two versions of the mosaic, one unfiltered (vallesmos.tif), and one produced with all images processed through a box filter with an averaged pixel tone of 7.699 (vallesmosflt.tif). Both mosaics are ArcView-ArcInfo ready in TIF format with associated world files (*.tfw).

  15. Spatial variations in composition of the Valles Marineris and Isidis Planitia regions of Mars derived from ISM data

    NASA Technical Reports Server (NTRS)

    Erard, S.; Bibring, J.-P.; Forni, O.; Mustard, J.; Head, J. W.

    1991-01-01

    The present study summarizes preliminary results of an analysis of spaceborne near-infrared imaging spectroscopic data obtained from the martian surface. The sources of spectral variation are identified and surface units are mapped on the basis of the observed spectral properties. The findings indicate that strong spectral variations exist down to the limit of spatial resolution (22 x 22 sq km) of the ISM instrument. The most discriminant criteria are brightness, strength of the 3-micron absorption due to hydration, and near-infrared spectral slope. Bright areas are relatively featureless, but spectral subunits can be delimited within them. Dark areas are heterogeneous, with variations related to mafic mineralogy and partial coatings by fine material. Topographic and spectroscopic maps compiled from the ISM data agree in general with previous results, but provide additional detail and compositional information.

  16. Hydrated Minerals Associated with Interior Layered Deposits near the Southern Wall of Melas Chasma, Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Arvidson, R. E.

    2011-12-01

    MRO CRISM full resolution targeted mode hyperspectral image data (FRT00013F5B) centered at 10.22 S, 74.46 W over a portion of the southern wall and nearby floor of Melas Chasma show a sequence of interior layered deposits with distinct mineral associations. This study area is located to the southeast of the region analyzed by Roach et al. (2010, Icarus, 206, 253-268). The topography associated the deposits was examined using standard product elevation maps derived from HRSC data and used along with superposition relationships to help define the stratigraphic order. The bottom of the exposed section consists of repeating interbedded monohydrated and polyhydrated sulfate-bearing layers. Jarosite-bearing layers are found above this sequence, along with layers that have a 2.3 micrometer absorption tentatively identified as due to Fe/Mg smectite-bearing material. The top of the section is dominated by an areally extensive polyhydrated sulfate-bearing unit. Detailed results will be presented along with an analysis of the changing aqueous conditions inferred from the mineral associations.

  17. Researcher position (PhD or PostDoc) at the Institute for Communications and Navigation Project Valles Marineris Explorer

    E-print Network

    Hirche, Sandra

    with autonomous rovers. The project aims at developing navigation techniques to support a future mission the reliability and accuracy of the autonomous robotic swarm's navigation system. The camera navigation subsystemResearcher position (PhD or PostDoc) at the Institute for Communications and Navigation Project

  18. Constraints on the Martian cratering rate imposed by the SNC meteorites and Vallis Marineris layered deposits

    NASA Technical Reports Server (NTRS)

    Brandenburg, J. E.

    1993-01-01

    Following two independent lines of evidence -- estimates of the age and formation time of a portion of the Martian geologic column exposed in the layered deposits and the crystallization and ejection ages of the SNC meteorites -- it appears that the Martian cratering rate must be double the lunar rate or even higher. This means models such as NHII or NHIII (Neukum and Hiller models II and III), which estimate the Martian cratering rate as being several times lunar are probably far closer to reality on Mars than lunar rates. The effect of such a shift is profound: Mars is transformed from a rather Moon-like place into a planet with vigorous dynamics, multiple large impacts, erosion, floods, and volcanism throughout its history. A strong shift upward in cratering rates on Mars apparently solves some glaring problems; however, it creates others. The period of time during which Earth-like atmospheric conditions existed, the liquid water era on Mars, persists in NHIII up to only 0.5 b.y. ago. Scenarios of extended Earth-like conditions on Mars have been discounted in the past because they would have removed many of the craters from the early bombardment era found in the south. It does appear that some process of crater removal was quite vigorous in the north during Mars' past. Evidence exists that the northern plains may have been the home of long-lived seas or perhaps even a paleo-ocean, so models exist for highly localized destruction of craters in the north. However, the question of how the ancient crater population could be preserved in the south under a long liquid-water era found in any high-cratering-rate models is a serious question that must be addressed. It does appear to be a higher-order problem because it involves low-energy dynamics acting in localized areas, i.e., erosion of craters in the south of Mars, whereas the two problems with the low-cratering-rate models involve high-energy events acting over large areas: the formation of the Vallis Marineris, the SNC ejecting impacts, and the global atmospheric pressure and temperature conditions that allow liquid water to exist as a robust entity anywhere on the Martian surface. In any case, it appears Mars is a more complex and dynamic planet than previously supposed. It has canyons dating from the middle to late period of its history that contain apparent lake sediments bedded deeper than most sediments on Earth. Recent multiple, violent impacts on Mars have apparently provided us with multiple random samples of its surface that all crystallized less than 1.5 b.y. ago. These things cannot be accommodated in our present cratering chronologies of Mars, based on 1x lunar cratering rates, without great difficulties. These difficulties suggest that a new chronology, probably based on NHII or even NHIII, should be adopted; this new chronology will provide us with a new view of Mars as a dynamic planet of rich history.

  19. Bryce Canyon Rim

    USGS Multimedia Gallery

    The rim of Bryce Canyon, viewed from Rainbow Point. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms ...

  20. Glen Canyon Dam

    USGS Multimedia Gallery

    The USGS Glen Canyon Adaptive Management Working Group took a trip in August from Glen Canyon Dam to Lees Ferry on Friday, August 31, 2012. This spot at Four Mile (four miles downstream from the dam) is where a lot of people fish: There were fishermen that day that claimed to have c...

  1. Bryce Canyon Sandstone

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  2. Bryce Canyon Natural Bridge

    USGS Multimedia Gallery

    Bryce Canyon's Natural Bridge is technically a natural arch, similar to those in the nearby Arches National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates...

  3. Bryce Canyon Amphitheater

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  4. Bryce Canyon's Cedar Valley

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  5. Bryce Canyon Hoodoo

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  6. Bryce Canyon Amphitheater Hoodoos

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  7. Bryce Canyon Hoodoos

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  8. Bryce Canyon Amphitheater Panorama

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  9. Bryce Canyon Natural Bridge

    USGS Multimedia Gallery

    The Bryce Canyon Natural Bridge. Technically, this is not a natural bridge, which forms when running water erodes a tunnel into a rock formation. Instead, this is a natural arch, similar to the ones in nearby Arches National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is...

  10. Hoodoos of Bryce Canyon

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  11. Bryce Canyon Cedars

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  12. Bryce Canyon Vistas

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sands...

  13. Bryce Canyon Benchmark

    USGS Multimedia Gallery

    A USGS elevation benchmark in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that ...

  14. Bryce Canyon Amphitheater

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sands...

  15. Bryce Canyon Hoodoos

    USGS Multimedia Gallery

    Sandstone hoodoos in Bryce Canyon National Park. In the background, Grand Staircase-Escalante National Monument can be seen. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different er...

  16. Bryce Canyon Hoodoo

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sands...

  17. Bryce Canyon Hoodoos

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sands...

  18. Hoodoos of Bryce Canyon

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sands...

  19. Fourmile Canyon Fire

    USGS Multimedia Gallery

    The beginning of the Fourmile Canyon fire, which burned about 6,000 acres in Boulder County, Colorado, in September 2010. Storms after wildfire led to downstream water-quality impairment. Photo taken from Bear Peak, near Boulder, CO....

  20. 18. VIEW OF A CANYON IN THE CLEANUP PHASE. CANYONS ...

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

    18. VIEW OF A CANYON IN THE CLEANUP PHASE. CANYONS WERE PROCESSING ROOMS USED TO HOUSE PLUTONIUM HANDLING OPERATIONS THAT WERE NOT CONTAINED WITHIN GLOVE BOXES. CANYONS WERE DESIGNED TO BECOME CONTAMINATED. (5/10/88) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  1. Landslide in Kasei Valles

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) continues in 2003 to return excellent, high resolution images of the red planet's surface. This nearly 1.5 meters (5 ft.) per pixel view of a landslide on a 200 meter-high (219 yards-high) slope in Kasei Valles was specifically targeted for scientific investigation by rotating the MGS spacecraft about 7.8o off-nadir in January 2003. The scar left by the landslide reveals layers in the bedrock at the top the slope and shows a plethora of dark-toned, house-sized boulders that rolled down the slope and collected at the base of the landslide scar. A few meteor impact craters have formed on the landslide deposit and within the scar, indicating that this landslide occurred a very long time ago. Sunlight illuminates this scene from the left/lower left; the landslide is located near 28.3oN, 71.9oW.

  2. FINAL REPORT CANYON AND SLOPE

    E-print Network

    Miller, Scott

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...11 #12;Introduction The eastern U.S. continental margin is incised by numerous submarine canyons operating in submarine canyons and on the slope , and to determine how these processes might transmit objectives were addressed : a) characterization of currents and hydrography within submarine canyons

  3. Thursday, March 26, 2009 MARS: TECTONICS AND DYNAMICS

    E-print Network

    Rathbun, Julie A.

    and displacement-length scaling relations to identify transient and long-term fault growth. 1:45 p.m. Wyrick D. Y. * The Opening of the Valles Marineris Canyons on Mars: Stress Focusing Along the Buried Dichotomy Boundary the preexisting crustal dichotomy boundary, which generated a narrow belt of strongly extensional stresses just

  4. Sandbar in Grand Canyon

    USGS Multimedia Gallery

    Picture showing the size of the sandbar before the November 2012 controlled flood from the Glen Canyon Dam. This location is 65 miles downstream from Lees Ferry and the view is looking downstream. These and additional photographs depicting the results of the recent controlled floods can be viewed on...

  5. Glen Canyon Dam

    USGS Multimedia Gallery

    The Glen Canyon Dam on the Colorado River in Arizona. At noon Monday, Nov. 19, U.S. Interior Secretary Ken Salazar will open the dam’s river outlet tubes, releasing controlled flows larger than the usual 8,000-25,000 cubic feet per second that flows through the turbines of the Glen...

  6. Flushing submarine canyons.

    PubMed

    Canals, Miquel; Puig, Pere; de Madron, Xavier Durrieu; Heussner, Serge; Palanques, Albert; Fabres, Joan

    2006-11-16

    The continental slope is a steep, narrow fringe separating the coastal zone from the deep ocean. During low sea-level stands, slides and dense, sediment-laden flows erode the outer continental shelf and the continental slope, leading to the formation of submarine canyons that funnel large volumes of sediment and organic matter from shallow regions to the deep ocean(1). During high sea-level stands, such as at present, these canyons still experience occasional sediment gravity flows(2-5), which are usually thought to be triggered by sediment failure or river flooding. Here we present observations from a submarine canyon on the Gulf of Lions margin, in the northwest Mediterranean Sea, that demonstrate that these flows can also be triggered by dense shelf water cascading (DSWC)-a type of current that is driven solely by seawater density contrast. Our results show that DSWC can transport large amounts of water and sediment, reshape submarine canyon floors and rapidly affect the deep-sea environment. This cascading is seasonal, resulting from the formation of dense water by cooling and/or evaporation, and occurs on both high- and low-latitude continental margins(6-8). DSWC may therefore transport large amounts of sediment and organic matter to the deep ocean. Furthermore, changes in the frequency and intensity of DSWC driven by future climate change may have a significant impact on the supply of organic matter to deep-sea ecosystems and on the amount of carbon stored on continental margins and in ocean basins. PMID:17108962

  7. Cedar Forest in Bryce Canyon

    USGS Multimedia Gallery

    A cedar forest in Bryce Canyon National Park, viewed from Rainbow Point. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the ...

  8. Bryce Canyon Wall of Windows

    USGS Multimedia Gallery

    Bryce Canyon's Wall of Windows, a series of sandstone arches and hoodoos in the Bryce Amphitheater. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolom...

  9. Cedar Forests of Bryce Canyon

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  10. Cedar Valley in Bryce Canyon

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  11. Rainbow Point of Bryce Canyon

    USGS Multimedia Gallery

    View of Bryce Canyon National Park from Rainbow Point. In the foreground are sandstone hoodoos and in the background is the Grand Staircase-Escalante National Monument, which is managed by the Bureau of Land Management. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a ...

  12. Rainbow Point of Bryce Canyon

    USGS Multimedia Gallery

    View of Bryce Canyon National Park from Rainbow Point. In the foreground are sandstone hoodoos. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite ...

  13. Snow-covered Bryce Canyon

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  14. Bryce Canyon's Wall of Windows

    USGS Multimedia Gallery

    Bryce Canyon's Wall of Windows, a series of sandstone arches and hoodoos in the Bryce Amphitheater. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolom...

  15. Cedar Tree in Bryce Canyon

    USGS Multimedia Gallery

    A cedar tree in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their ba...

  16. Bryce Canyon's Navajo Loop Trail

    USGS Multimedia Gallery

    Views along the Navajo Loop Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandston...

  17. Sunset over Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  18. Sunset in Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  19. Sunset over Red Rock Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  20. Yucca in Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  1. Chollas in Pine Creek Canyon

    USGS Multimedia Gallery

    The Mojave Desert, home to drought-tolerant plants like Cholla cacti, gradually mixes with loblolly pine ecosystems in Pine Creek Canyon. Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Roc...

  2. Manzanita in Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  3. Yuccas in Pine Creek Canyon

    USGS Multimedia Gallery

    The Mojave Desert, home to drought-tolerant plants like yuccas, gradually mixes with loblolly pine ecosystems in Pine Creek Canyon. Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Cany...

  4. Shallow seismic investigations in the Valles Caldera

    E-print Network

    West, Michael

    Shallow seismic investigations in the Valles Caldera Presented by: Michael West, New Mexico State component of JTEX · Three lines centered on caldera · NW-SE deployed in 1993 · E-W & SW-NE in 1995 velocity material beneath rift · Strong contrast between east and west sides · Hint of Valle Grande caldera

  5. The Grand Canyon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Northern Arizona and the Grand Canyon are captured in this pair of MISR images from December 31, 2000 (Terra orbit 5525). The left-hand image is a true color view from the nadir (vertical) camera. The right-hand image is a stereo composite generated using data from MISR's vertical and 46-degree-forward cameras. Viewing the stereo image in 3-D requires the use of red/blue glasses with the red filter placed over your left eye. To facilitate stereo viewing, the images have been oriented with north at the left.

    In addition to the Grand Canyon itself, which is visible in the western (lower)half of the images, other landmarks include Lake Powell, on the left, and Humphreys Peak and Sunset Crater National Monument on the right. Meteor Crater appears as a small dark depression with a brighter rim, and is just visible along the upper right-hand edge. Can you find it?

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  6. Holden Crater/Uzboi Valles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 17 April 2002) The Science This image, located near 27.0S and 35.5W (324.5E), displays the intersection of Holden Crater with Uzboi Valles. This region of Mars contains a number of features that could be related to liquid water on the surface in the Martian past. Holden Crater contains finely layered sedimentary units that have been subsequently dissected. The hummucky terrain in the bottom half of the image is the remnants of this terrain, though the fine layers are not visible in this image at this resolution. The sedimentary units could have formed through deposition of material in a lacustrine type environment. Alternately, these layers could also be volcanic ash deposits. Uzboi Valles, which enters the crater from the southwest, is a catastrophic outflow channel that formed in the Martian past. The streamlined nature of the topographic features at the intersection of the crater with Uzboi Valles record the erosional pattern of flowing liquid water on the surface of Mars during the episodic outflow event. The Story Mars doesn't have a shortage of rugged terrain, and this area is no exception. While things look pretty quiet now, this cratered region was once the scene of some tremendous action. Long ago in Martian history, an incoming meteoroid probably smashed into the planet and produced a giant impact crater named Holden Crater, which stretches 88 miles across the Martian surface. The history of the area around Holden Crater doesn?t stop there. At some point, a catastrophic flood burst forth on the surface, forming an impressive outflow channel called Uzboi Valles. No one knows exactly how that happened, or whether the water might even have rushed into Holden Crater at some point, forming a long-ago lake. What we do know is that there is a lot of sedimentary material that could have formed in two hypothesized ways: in an ancient lake environment or as volcanic-ash deposits. Scientists are searching for the answers by studying the region where Uzboi Valles meets the crater. You can see the rough edge of Holden Crater running diagonally down in a sharply edged swath (from the top left-hand corner of this image to the center right-hand side). Just below it, running almost smoothly down the right-hand side of the image is an intriguing channel where water may once have flowed. Much of the terrain in the bottom half of the image, in fact, seems to be cut into a swish-swash of dissected sedimentary terrain. Sliced through in such a way, the terrain ends up carrying bunches of small, rounded hills called 'hummocks.' Earth can boast of its own rolling, hummocky terrain too, such as that found in the ravine-cut Missouri Hills and High Plains areas of South Dakota.

  7. New York Canyon Stimulation

    SciTech Connect

    Raemy, Bernard

    2012-06-21

    The New York Canyon Stimulation Project was to demonstrate the commercial application of Enhanced Geothermal System techniques in Buena Vista Valley area of Pershing County, Nevada. From October 2009 to early 2012, TGP Development Company aggressively implemented Phase I of Pre-Stimulation and Site/Wellbore readiness. This included: geological studies; water studies and analyses and procurement of initial permits for drilling. Oversubscription of water rights and lack of water needed for implementation of EGS were identified and remained primary obstacles. Despite extended efforts to find alternative solutions, the water supply circumstances could not be overcome and led TGP to determine a "����No Go"��� decision and initiate project termination in April 2012.

  8. Repainting decontaminated canyon cranes

    SciTech Connect

    Not Available

    1984-08-23

    The paint on the H-area hot canyon crane is expected to be at least partially removed during the planned decontamination with high pressure Freon/reg sign/ blasting. Tests to evaluate two candidate finishes, DuPont Imron/reg sign/ polyurethane enamel and DuPont Colar/reg sign/ epoxy were carried out at Quadrex Co., Oak Ridge, TN, March 1984. Three types of 304L stainless steel surface finishes were included in the test (ASTM No. 1, bead blasted ASTM No. 1, and ASTM No. 2B). Two types of contamination were used (diluted dissolver solution, the type of contamination encountered in existing canyons; and raw sludge plus volatiles, the type of contamination expected in DWPF). Some specimens were coated with the type of grease (Mystic JT-6) used on cranes in SRP separations areas. The results of the test indicate that smoother surfaces are easier to decontaminate than rougher surfaces. Statistical analysis of the data from this experiment by R.L. Postles leads to the following conclusions: There is no statistical difference between the decontamination properties of DuPont Imron/reg sign/ polyurethane enamel and DuPont Colar/reg sign/ epoxy; DuPont Imron/reg sign/ polyurethane enamel and perhaps Type 304L stainless steel with an ASTM No. 2B surface finish are easier to decontaminate than Type 304L stainless steel with an ASTM No. 1 surface finish; dilute dissolver solution is harder to remove than raw sludge plus volatiles; specimens with grease are easier to decontaminate than specimens with no grease; and, Freon/reg sign/ blasting pressure has no statistically significant effect. 2 refs., 1 fig., 4 tabs.

  9. Layering in the wall rock of Valles Marineris: intrusive and extrusive Jean-Pierre Williams, David A. Paige, and Craig E. Manning

    E-print Network

    Manning, Craig

    ] One of the most significant early discoveries made by the Mars Global Surveyor (MGS) Mars Orbiter Planetology: Solar System Objects: Mars; 8450 Volcanology: Planetary volcanism (5480). Citation: Williams, J (45 to 90°W longitude) were analyzed encompassing images released from aerobraking to extended mission

  10. Mineral resources of the Desolation Canyon, Turtle Canyon, and Floy Canyon Wilderness Study Areas, Carbon Emery, and Grand counties, Utah

    SciTech Connect

    Cashion, W.B.; Kilburn, J.E.; Barton, H.N.; Kelley, K.D.; Kulik, D.M. ); McDonnell, J.R. )

    1990-09-01

    This paper reports on the Desolation Canyon, Turtle Canyon, and Floy Canyon Wilderness Study Areas which include 242,000 acres, 33,690 acres, and 23,140 acres. Coal deposits underlie all three study areas. Coal zones in the Blackhawk and Nelsen formations have identified bituminous coal resources of 22 million short tons in the Desolation Canyon Study Area, 6.3 million short tons in the Turtle Canyon Study Area, and 45 million short tons in the Floy Canyon Study Area. In-place inferred oil shale resources are estimated to contain 60 million barrels in the northern part of the Desolation Canyon area. Minor occurrences of uranium have been found in the southeastern part of the Desolation Canyon area and in the western part of the Floy Canyon area. Mineral resource potential for the study areas is estimated to be for coal, high for all areas, for oil and gas, high for the northern tract of the Desolation Canyon area and moderate for all other tracts, for bituminous sandstone, high for the northern part of the Desolation Canyon area, and low for all other tracts, for oil shale, low in all areas, for uranium, moderate for the Floy Canyon area and the southeastern part of the Desolation Canyon area and low for the remainder of the areas, for metals other than uranium, bentonite, zeolites, and geothermal energy, low in all areas, and for coal-bed methane unknown in all three areas.

  11. 82nd Field Artillery in Box Canyon 

    E-print Network

    Unknown

    2011-09-05

    Two modes of sediment transport were found to exist in the Mississippi Canyon: the offshelf transport of material in intermediate nepheloid layers originating at depths of 50-175 m and the resuspension and transport of material within the canyon...

  12. Mineralogical Stratigraphy of Ganges Chasma, Mars

    NASA Astrophysics Data System (ADS)

    Cull-Hearth, Selby; Clark, M. Caroline

    2015-11-01

    Mars’ Valles Marineris canyon system reveals a several-kilometer deep stratigraphies sequence that extends thousands of kilometers; this sequence thus represents a unique opportunity to explore millions of years of volcanic and aqueous activity in this region of Mars. Of particular interest to the study of both volcanic and aqueous processes is Ganges Chasma, which lies on the northeastern boundary of the Valles Marineris canyon system on Mars. The canyon likely opened during the Late Noachian to Early Hesperian, modifying previously emplaced Noachian-aged volcanic plains. During formation, volcanic activity from the nearby Tharsis shield complex emplaced olivine-rich dikes throughout the region. After formation, sulfate-bearing Interior Layered Deposits (ILDs) were emplaced in Ganges and many other chasmata throughout the Valles Marineris system. Today, Ganges reveals a complex stratigraphy, including wide-spread olivine-rich sands, hydrated minerals on the plateaus surrounding the canyon, and a central sulfate-rich ILD. Here, we present updated stratigraphies of Ganges Chasma, using new data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), and synthesizing it with previous data sets. Olivine sands are traced back to source outcrops on the canyon floor, and new outcrops of hydrated minerals on the surrounding plateau are identified and mapped. Recently reported spectroscopic signatures of ankerite and smectite in the chasm are assessed, and new olivine-rich outcrops identified and mapped. Understanding the stratigraphy of Ganges Chasma will help us compare stratigraphies among the chasmata of the Valles Marineris, further building our understanding of the geologic history of this large region of Mars.

  13. Currents in monterey submarine canyon

    USGS Publications Warehouse

    Xu, J. P.; Noble, M.A.

    2009-01-01

    Flow fields of mean, subtidal, and tidal frequencies between 250 and 3300 m water depths in Monterey Submarine Canyon are examined using current measurements obtained in three yearlong field experiments. Spatial variations in flow fields are mainly controlled by the topography (shape and width) of the canyon. The mean currents flow upcanyon in the offshore reaches (>1000 m) and downcanyon in the shallow reaches (100-m amplitude isotherm oscillations and associated high-speed rectilinear currents. The 15-day spring-neap cycle and a ???3-day??? band are the two prominent frequencies in subtidal flow field. Neither of them seems directly correlated with the spring-neap cycle of the sea level.

  14. Stratigraphy of the Kasei Valles region, Mars

    NASA Technical Reports Server (NTRS)

    Robinson, Mark S.; Tanaka, Kenneth L.

    1987-01-01

    The thicknesses and geomorphology of the two principal stratigraphic units exposed in Kasei Valles to aid in interpreting the nature of crustal materials and the history of the channeling events in the area are identified and described. Previous studies of Kasei Valles have related the channel landforms to glacial flow, catastrophic flooding, and large-scale eolian erosion. The two units (an upper and a lower unit) form thick sheets, each having distinct geomorphologic features. Thicknesses of the unit were determined through preliminary stereogrammetric profiles taken across many sections of western Kasei Valles and shadow measurements taken of scarp heights from calibrated Viking images having sun angles less than 25 degrees; DN values were examined to confirm that true shadows were observed.

  15. Thomas Moran: "The Grand Canyon."

    ERIC Educational Resources Information Center

    Brubaker, Ann

    1986-01-01

    Presents a lesson plan for introducing students in grades four through six to Thomas Moran's painting, "The Grand Canyon." The goal of the lesson is to illustrate the importance of the American West as a subject for artists in the nineteenth century. (JDH)

  16. Tubes at Glen Canyon Dam

    USGS Multimedia Gallery

    The river outlet tubes at Glen Canyon Dam on the Colorado River in Arizona. At noon Monday, Nov. 19, U.S. Interior Secretary Ken Salazar will open the dam's river outlet tubes, releasing controlled flows larger than the usual 8,000-25,000 cubic feet per second that flows through the turbines of...

  17. Amplification of bedrock canyon incision by wind

    NASA Astrophysics Data System (ADS)

    Perkins, J. P.; Finnegan, N. J.; de Silva, S. L.

    2013-12-01

    Bedrock canyons etch much of the surface of Earth and Mars, and commonly inform interpretations of long-term hydrologic or tectonic changes within these landscapes. However, many bedrock canyons (particularly on Mars) exist in arid environments where wind abrasion can dramatically alter surface morphology. Although it is hypothesized that wind carves or modifies bedrock canyons on Mars, the interplay of wind and fluvial processes in shaping canyon landscapes is, to our knowledge, unexplored. Consequently, here we exploit a natural experiment along the 4.09 Ma Puripicar ignimbrite, situated on the western slope of the Andes in the Atacama Desert and subject to significant erosion from both wind and rivers. The Puripicar exhibits a series of bedrock gorges nested behind a broad north-south escarpment whose southern half is protected from wind by a large topographic barrier. This shielding provides a natural control to examine the effects of wind abrasion on canyon morphology and in particular knickpoint retreat. Our results show that for a given drainage area, knickpoints in wind-affected canyons have incised an order of magnitude farther upstream than wind-protected canyons. In addition, wind-affected canyons are wider and have more streamlined aspect ratios for a given drainage area than wind-protected canyons. Aeolian abrasion appears to result in knickpoints with average slopes half those of shielded canyons (0.2 and 0.4, respectively). Lastly, although the magnitude of knickpoint retreat is larger in wind-affected canyons, the scaling exponent between knickpoint retreat and drainage area is virtually identical for wind-affected canyons (0.56, R = 0.71) and wind-protected canyons (0.60, R = 0.80). Taken together, our results suggest that fluvial incision and wind abrasion are coupled processes in this landscape: convergent canyons funnel wind towards knickpoints, thereby leading to enhanced aeolian abrasion rates at knickpoints. We speculate that the apparent drainage area dependence of knickpoint retreat in wind-affected canyons reflects the fact that larger rivers create wider canyon mouths. Larger canyons mouths, in turn, increase wind convergence and drive higher aeolian abrasion rates at the heads of larger canyons. This study is the first to demonstrate knickpoint retreat via wind abrasion, and highlights that even in landscapes where large river gorges are present, wind may still exert a dominant control on canyon morphology.

  18. Geomorphic process fingerprints in submarine canyons

    USGS Publications Warehouse

    Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.; Twichell, David C.

    2013-01-01

    Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.

  19. Mineral resources of the Coal Canyon, Spruce Canyon, and Flume Canyon Wilderness Study Areas, Grand county, Utah

    SciTech Connect

    Dickerson, R.P.; Gaccetta, J.D.; Kulik, D.M.; Kreidler, T.J.

    1990-01-01

    This paper reports on the Coal Canyon, Spruce Canyon, and Flume Canyon Wilderness Study Areas in the Book and Roan Cliffs in Grand Country, Utah, approximately 12 miles west of the Colorado state line. The wilderness study areas consist of a series of deep, stair-step-sided canyons and high ridges eroded into the flatlying sedimentary rocks of the Book Cliffs. Demonstrated coal reserves totaling 22,060,800 short tons and demonstrated subeconomic coal resources totaling 39,180,000 short tons are in the Coal Canyon Wilderness Study Area. Also, inferred subeconomic coal resources totaling 143,954,000 short tons are within the Coal Canyon Wilderness Study Area. No known deposits of industrial minerals are in any of the study area. All three of the wilderness study areas have a high resource potential for undiscovered deposits of coal and for undiscovered oil and gas.

  20. Introduction Steven M. LaValle

    E-print Network

    LaValle, Steven M.

    Available for downloading at http://msl.cs.uiuc.edu/vr/ #12;Chapter 1 Introduction Chapter Status Taken from Virtual Reality, S. M. LaValle This online chapter is not the final version! Check http://msl.cs.uiuc.edu/vr Reality? Virtual reality (VR) technology is evolving rapidly, making it precarious to define VR in terms

  1. A GEOLOGICAL AND GEOPHYSICAL STUDY OF THE BACA GEOTHERMAL FIELD, VALLES CALDERA, NEW MEXICO

    SciTech Connect

    Wilt, M.; Haar, S.V.

    1982-03-01

    The Baca location {number_sign}1 geothermal field is located in north-central New Mexico within the western half of the Plio-Pleistocene valles Caldera. Steam and hot water are produced primarily from the northeast-trending Redondo Creek graben, where downhole temperatures exceed 500 F. Stratigraphically the reservoir region can be described as a five-layer sequence that includes (1) caldera fill and the upper units of the Bandelier ash flow tuff, (2) the lower members of this tuff, which comprise the main reservoir rock at Baca, (3) the Pliocene Paliza Canyon volcanics, (4) Tertiary sands and Paleozoic sedimentary rocks, and (5) Precambrian granitic basement. Production is controlled by fractures and faults that are ultimately related to activity in the Rio Grande Rift system. Geophysically, the caldera is characterized by a gravity minimum and a resistivity low. A 40-mgal gravity minimum over the caldera is due mostly to the relatively low-density volcanics and sediments that fill the caldera and probably bears no relation to deep-seated magmatic sources. Two-dimensional gravity modeling indicates that the depth to Precambrian basement in Redondo Canyon is probably at least 3 km and may exceed 5 km in eastern parts of the caldera. Telluric and magnetotelluric surveys have shown that the reservoir region is associated with low resistivity and that a deep low-resistivity zone correlates well with the depth of the primary reservoir inferred from well data.

  2. Ares Valles: Night and Day

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 15 June 2004 This pair of images shows part of the Ares Valles region.

    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 3.6, Longitude 339.9 East (20.1 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 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.

  3. 77 FR 22801 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ...Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation...The Glen Canyon Dam Adaptive Management Work Group (AMWG) makes recommendations to...advisory committee, the AMWG, a technical work group, a Grand Canyon Monitoring and...

  4. PROCESSUS GRAVITAIRES TARDI-QUATERNAIRES DANS LES CANYONS ET

    E-print Network

    Barnes, Sarah-Jane

    dans un contexte tectonique et climatique similaire. #12;iv #12;v ABSTRACT Submarine canyons continental sediments reach deeper sedimentary basins. Numerous submarine canyons and channels incisei PROCESSUS GRAVITAIRES TARDI- QUATERNAIRES DANS LES CANYONS ET CHENAUX SOUS-MARINS DU SAINT

  5. "Internal Waves" Advancing along Submarine Canyons.

    PubMed

    Shepard, F P; Marshall, N F; McLoughlin, P A

    1974-01-18

    Patterns of alternating up- and downcanyon currents have been traced along the axes of submarine canyons off California. The patterns arrive later at stations nearer the heads of coastal canyons. Where a canyon heads between two islands, the patterns advance down the axis. The propagation speeds of these patterns were estimated as 25 to 88 centimeters per second. Internal waves are the probable explanation. PMID:17777263

  6. Bell Canyon test and results

    SciTech Connect

    Christensen, C.L.; Hunter, T.O.

    1980-01-01

    The purposes of the Borehold Plugging Program are: to identify issues associated with sealing boreholes and shafts; to establish a data base from which to assess the importance of these issues; and to develop sealing criteria, materials, and demonstrative test for the Waste Isolation Pilot Plant (WIPP). The Bell Canyon Test described in this report is one part of that program. Its purpose was to evaluate, in situ, the state of the art in borehole plugs and to identify and resolve problems encountered in evaluating a typical plug installation in anhydrite. The test results are summarized from the work of Peterson and Christensen and divided into two portions: system integrity and wellbore characterization tests prior to plug installation, and a series of tests to evaluate isolation characteristics of the 1.8-m-long plug. Conclusions of the Bell Canyon Test are: brine and fresh-water grouts, with acceptable physical properties in the fluid and hardened states, have been developed; the field data, taken together with laboratory data, suggest that the predominant flow into the test region occurs through the cement plug/borehold interface region, with lesser contributions occurring through the wellbore damage zone, the plug core, and the surrounding undisturbed anhydrite bed; and the 1.8-m-long by 20-cm-diameter grout plug, installed in anhydrite at a depth of 1370 m in the AEC-7 borehole, limits flow from the high pressure Bell Canyon aquifer to 0.6 liters/day.

  7. Streamlined Islands in Ares Valles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 10 June 2002) The Science Although liquid water is not stable on the surface of Mars today, there is substantial geologic evidence that large quantities of water once flowed across the surface in the distant past. Streamlined islands, shown here, are one piece of evidence for this ancient water. The tremendous force of moving water, possibly from a catastrophic flood, carved these teardrop-shaped islands within a much larger channel called Ares Valles. The orientation of the islands can be used as an indicator of the direction the water flowed. The islands have a blunt end that is usually associated with an obstacle, commonly an impact crater. The crater is resistant to erosion and creates a geologic barrier around which the water must flow. As the water flows past the obstacle, its erosive power is directed outward, leaving the area in the lee of the obstacle relatively uneroded. However, some scientists have also argued that the area in the lee of the obstacle might be a depositional zone, where material is dropped out of the water as it briefly slows. The ridges observed on the high-standing terrain in the leeward parts of the islands may be benches carved into the rock that mark the height of the water at various times during the flood, or they might be indicative of layering in the leeward rock. As the water makes its way downstream, the interference of the water flow by the obstacle is reduced, and the water that was diverted around the obstacle rejoins itself at the narrow end of the island. Therefore, the direction of the water flow is parallel to the orientation of the island, and the narrow end of the island points downstream. In addition to the streamlined islands, the channel floor exhibits fluting that is also suggestive of flowing water. The flutes (also known as longitudinal grooves) are also parallel to the direction of flow, indicating that the water flow was turbulent and probably quite fast, which is consistent with the hypothesized catastrophic floods that came through Ares Valles. The Story In symbolism only, these guppy-shaped islands and current-like flutes of land beside them may conjure up a mental image of a flowing Martian river. This picture would only be half-right. Scientifically, no fish ever swam this channel, but these landforms do reveal that catastrophic floods of rushing water probably patterned the land in just this way. Geologists who study flood areas believe that a tremendous force of moving water probably carved both the islands and the small, parallel, 'current-like' ridges around them. The blunt end of the islands (the 'heads' of the 'fish') are probably ancient impact craters that posed obstacles to the water as it rushed down the channel in torrents. Because a crater is resistant to erosion, it creates a geologic barrier around which the water must flow. As the water makes its way downstream, the crater's interference with the water flow is reduced, so the water that was diverted around the obstacle rejoins at the narrow end of the island (the 'tail' of the 'fish'). Therefore, from this information, you can tell that the water flowed from the southeast to the northwest. As a rule of thumb for the future, you can say that the narrow end of the island points downstream. The result may be the island behind the crater, but geologists disagree about the exact process by which the island forms. Some scientists argue that the erosive power of the water is directed outward, leaving the area behind, or in the lee of, the obstacle relatively untouched. Other scientists argue that the water slows when it encounters the crater obstacle, and small particles of sand and 'dirt' drop out of the water and are deposited in the lee. There's another small associated uncertainty too. Look closely at the edges of the islands and notice how the land is terraced. These ledges might mark the height of the water at various times during the flood . . . or they might be an indication that layering occurred. It all depends on your hypothesis. Like the stream

  8. Role of submarine canyons in shaping the rise between Lydonia and Oceanographer canyons, Georges Bank

    USGS Publications Warehouse

    McGregor, B.A.

    1985-01-01

    Three large submarine canyons, Oceanographer, Gilbert, and Lydonia, indent the U.S. Atlantic continental shelf and, with four additional canyons, dissect the continental slope in the vicinity of Georges Bank. On the upper rise, these canyons merge at a water depth of approximately 3100 m to form only two valleys. Differences in channel morphology of the canyons on the upper rise imply differences in relative activity, which is inconsistent with observations in the canyon heads. At present, Lydonia Canyon incises the upper rise more deeply than do the other canyons: however, seismic-reflection profiles show buried channels beneath the rise, which suggests that these other six canyons were periodically active during the Neogene. The rise morphology and the thickness of inferred Neogene- and Quaternary-age sediments on the rise are attributed to the presence and activity of the canyons. The erosional and depositional processes and the morphology of these canyons are remarkably similar to those of fluvial systems. Bear Seamount, which has approximately 2000 m of relief on the rise, has acted as a barrier to downslope sediment transport since the Late Cretaceous. Sediment has piled up on the upslope side, whereas much less sediment has accumulated in the "lee shadow" on the downslope side. Seismic-reflection profile data show that Lydonia Canyon has not eroded down to the volcanic rock of Bear Seamount. ?? 1985.

  9. Bryce Canyon and Grand Staircase-Escalante

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  10. Snow-covered Sandstone at Bryce Canyon

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  11. Panorama of Bryce Canyon National Park

    USGS Multimedia Gallery

    Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their base. Bryce Canyon is also home to large numbe...

  12. Bryce Canyon and Grand Staircase-Escalante

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park; Grand Staircase-Escalante National Monument can be seen in the background. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed d...

  13. 76 FR 8359 - Boulder Canyon Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ...) is proposing an adjustment to the Boulder Canyon Project (BCP) electric service base charge and rates... kilowattmonth (kWmonth), and the proposed composite rate is 22.16 mills/kWh. \\1\\ 75 FR 57912. \\2\\ 133 FERC ] 62... Area Power Administration Boulder Canyon Project AGENCY: Western Area Power Administration,...

  14. Sunset Panorama in Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  15. Barrel Cactus in Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  16. Loblolly Pines in Pine Creek Canyon

    USGS Multimedia Gallery

    Pine Creek Canyon is a remnant ecosystem of loblolly pines. A remnant ecosystem is the last vestige of an ecosystem type that used to be more widespred. Red Rock Canyon is a National Conservation Area managed by the Bureau of Land Management, located just outside of Las Vegas, Nevada. It is part of...

  17. ACCELERATED PILOT PROJECT FOR U CANYON DEMOLITION

    SciTech Connect

    KEHLER KL

    2011-01-13

    At the U.S. Department of Energy's Hanford Site in southeast Washington State, CH2M HILL Plateau Remediation Company (CH2M HILL) is underway on a first-of-a-kind project with the decommissioning and demolition of the U Canyon. Following the U.S. Environmental Protection Agency's Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) Record of Decision for the final remediation of the canyon, CH2M HILL is combining old and new technology and techniques to prepare U Canyon for demolition. The selected remedial action called first for consolidating and grouting equipment currently in the canyon into lower levels of the plant (openings called cells), after which the cell galleries, hot pipe trench, ventilation tunnel, drains and other voids below the operating deck and crane-way deck levels will be filled with approximately 20,000 cubic yards of grout and the canyon roof and walls demolished down to the approximate level of the canyon deck. The remaining canyon structure will then be buried beneath an engineered barrier designed to control potential contaminant migration for a 500-year life. Methods and lessons learned from this project will set the stage for the future demolition of Hanford's four other canyon-type processing facilities.

  18. Grand Canyon Monitoring and Research Center

    USGS Publications Warehouse

    Hamill, John F.

    2009-01-01

    The Grand Canyon of the Colorado River, one of the world's most spectacular gorges, is a premier U.S. National Park and a World Heritage Site. The canyon supports a diverse array of distinctive plants and animals and contains cultural resources significant to the region's Native Americans. About 15 miles upstream of Grand Canyon National Park sits Glen Canyon Dam, completed in 1963, which created Lake Powell. The dam provides hydroelectric power for 200 wholesale customers in six western States, but it has also altered the Colorado River's flow, temperature, and sediment-carrying capacity. Over time this has resulted in beach erosion, invasion and expansion of nonnative species, and losses of native fish. Public concern about the effects of Glen Canyon Dam operations prompted the passage of the Grand Canyon Protection Act of 1992, which directs the Secretary of the Interior to operate the dam 'to protect, mitigate adverse impacts to, and improve values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established...' This legislation also required the creation of a long-term monitoring and research program to provide information that could inform decisions related to dam operations and protection of downstream resources.

  19. Urban street canyons: Coupling dynamics, chemistry and within-canyon chemical processing of emissions

    NASA Astrophysics Data System (ADS)

    Bright, Vivien Bianca; Bloss, William James; Cai, Xiaoming

    2013-04-01

    Street canyons, formed by rows of buildings in urban environments, are associated with high levels of atmospheric pollutants emitted primarily from vehicles, and substantial human exposure. The street canyon forms a semi-enclosed environment, within which emissions may be entrained in a re-circulatory system; chemical processing of emitted compounds alters the composition of the air vented to the overlying boundary layer, compared with the primary emissions. As the prevailing atmospheric chemistry is highly non-linear, and the canyon mixing and predominant chemical reaction timescales are comparable, the combined impacts of dynamics and chemistry must be considered to quantify these effects. Here we report a model study of the coupled impacts of dynamical and chemical processing upon the atmospheric composition in a street canyon environment, to assess the impacts upon air pollutant levels within the canyon, and to quantify the extent to which within-canyon chemical processing alters the composition of canyon outflow, in comparison to the primary emissions within the canyon. A new model for the simulation of street canyon atmospheric chemical processing has been developed, by integrating an existing Large-Eddy Simulation (LES) dynamical model of canyon atmospheric motion with a detailed chemical reaction mechanism, a Reduced Chemical Scheme (RCS) comprising 51 chemical species and 136 reactions, based upon a subset of the Master Chemical Mechanism (MCM). The combined LES-RCS model is used to investigate the combined effects of mixing and chemical processing upon air quality within an idealised street canyon. The effect of the combination of dynamical (segregation) and chemical effects is determined by comparing the outputs of the full LES-RCS canyon model with those obtained when representing the canyon as a zero-dimensional box model (i.e. assuming mixing is complete and instantaneous). The LES-RCS approach predicts lower (canyon-averaged) levels of NOx, OH and HO2, but higher levels of O3, compared with the box model run under identical chemical and emissions conditions. When considering the level of chemical detail implemented, segregation effects were found to reduce the error introduced by simplifying the reaction mechanism. Chemical processing of emissions within the canyon leads to a significant increase in the Ox flux from the canyon into the overlying boundary layer, relative to primary emissions, for the idealised case considered here. These results demonstrate that within-canyon atmospheric chemical processing can substantially alter the concentrations of pollutants injected into the urban canopy layer, compared with the raw emission rates within the street canyon. The extent to which these effects occur is likely to be dependent upon the nature of the domain (canyon aspect ratio), prevailing meteorology and emission/pollution scenario considered.

  20. Geology and biology of Oceanographer submarine canyon.

    USGS Publications Warehouse

    Valentine, P.C.; Uzmann, J.R.; Cooper, R.A.

    1980-01-01

    Santonian beds more than 100 m thick are the oldest rocks collected from the canyon. Quaternary silty clay veneers the canyon walls in many places and is commonly burrowed by benthic organisms that cause extensive erosion of the canyon walls, especially in the depth zone (100-1300 m) inhabited by the crabs Geryon and Cancer. Bioerosion is minimal on high, near-vertical cliffs of sedimentary rock, in areas of continual sediment movement, and where the sea floor is paved by gravel. A thin layer of rippled, unconsolidated silt and sand is commonly present on the canyon walls and in the axis. Shelf sediments are transported from Georges Bank over the E rim and in the Canyon by the SW drift and storm currents; tidal currents and internal waves move the sediment downcanyon along the walls and axis.- from Authors

  1. H-Canyon Recovery Crawler

    SciTech Connect

    Kriikku, E. M.; Hera, K. R.; Marzolf, A. D.; Phillips, M. H.

    2015-08-01

    The Nuclear Material Disposition Project group asked the Savannah River National Lab (SRNL) Research and Development Engineering (R&DE) department to help procure, test, and deploy a remote crawler to recover the 2014 Inspection Crawler (IC) that tipped over in the H-Canyon Air Exhaust Tunnel. R&DE wrote a Procurement Specification for a Recovery Crawler (RC) and SRNS Procurement Department awarded the contract to Power Equipment Manufacturing Inc. (PEM). The PEM RC was based on their standard sewer inspection crawler with custom arms and forks added to the front. The arms and forks would be used to upright the 2014 Inspection Crawler. PEM delivered the RC and associated cable reel, 2014 Inspection Crawler mockup, and manuals in late April 2015. R&DE and the team tested the crawler in May of 2015 and made modifications based on test results and Savannah River Site (SRS) requirements. R&DE delivered the RC to H-Area at the end of May. The team deployed the RC on June 9, 10, and 11, 2015 in the H-Canyon Air Exhaust Tunnel. The RC struggled with some obstacles in the tunnel, but eventually made it to the IC. The team spent approximately five hours working to upright the IC and eventually got it on its wheels. The IC travelled approximately 20 feet and struggled to drive over debris on the air tunnel floor. Unfortunately the IC tripped over trying to pass this obstacle. The team decided to leave the IC in this location and inspect the tunnel with the RC. The RC passed the IC and inspected the tunnel as it travelled toward H-Canyon. The team turned the RC around when it was about 20 feet from the H-Canyon crossover tunnel. From that point, the team drove the RC past the manway towards the new sand filter and stopped approximately 20 feet from the new sand filter. The team removed the RC from the tunnel, decontaminated the RC, and stored it the manway building, 294-2H. The RC deployment confirmed the IC was not in a condition to perform useful tunnel inspections and would require significant maintenance to become inspection ready. The RC traveled approximately 660 feet in the tunnel and viewed the tunnel and ceiling wall surfaces that were not blocked by existing ducts. This deployment also documented the tunnel obstacles for future inspections. Overall, the RC deployment was a success.

  2. Primary Initiation of Submarine Canyons

    E-print Network

    J. Marvin Herndon

    2011-02-02

    The discovery of close-to-star gas-giant exo-planets lends support to the idea of Earth's origin as a Jupiter-like gas-giant and to the consequences of its compression, including whole-Earth decompression dynamics that gives rise, without requiring mantle convection, to the myriad measurements and observations whose descriptions are attributed to plate tectonics. I propose here another, unanticipated consequence of whole-Earth decompression dynamics: namely, a specific, dominant, non-erosion, underlying initiation-mechanism precursor for submarine canyons that follows as a direct consequence of Earth's early origin as a Jupiter-like gas-giant.

  3. Primary Initiation of Submarine Canyons

    E-print Network

    Herndon, J Marvin

    2011-01-01

    The discovery of close-to-star gas-giant exo-planets lends support to the idea of Earth's origin as a Jupiter-like gas-giant and to the consequences of its compression, including whole-Earth decompression dynamics that gives rise, without requiring mantle convection, to the myriad measurements and observations whose descriptions are attributed to plate tectonics. I propose here another, unanticipated consequence of whole-Earth decompression dynamics: namely, a specific, dominant, non-erosion, underlying initiation-mechanism precursor for submarine canyons that follows as a direct consequence of Earth's early origin as a Jupiter-like gas-giant.

  4. THE ORIGI N ANDSEDIMENTOLOGYOF THE PUNASUBMARINE CANYON,HAhIAII

    E-print Network

    Qiu, Bo

    submarine canyons the Puna Canyon is sediment-starved. The distribution paterns of 7 trace elemenLs impliesTHE ORIGI N ANDSEDIMENTOLOGYOF THE PUNASUBMARINE CANYON,HAhIAII A DISSERTATIONSUBMITTEDTO Submarrne Canyon lres oFf the east coast of Lhe rsland of Hawarr, the youngest rsland of the Hawallan Charn

  5. Prehistoric deforestation at Chaco Canyon?

    PubMed

    Wills, W H; Drake, Brandon L; Dorshow, Wetherbee B

    2014-08-12

    Ancient societies are often used to illustrate the potential problems stemming from unsustainable land-use practices because the past seems rife with examples of sociopolitical "collapse" associated with the exhaustion of finite resources. Just as frequently, and typically in response to such presentations, archaeologists and other specialists caution against seeking simple cause-and effect-relationships in the complex data that comprise the archaeological record. In this study we examine the famous case of Chaco Canyon, New Mexico, during the Bonito Phase (ca. AD 860-1140), which has become a prominent popular illustration of ecological and social catastrophe attributed to deforestation. We conclude that there is no substantive evidence for deforestation at Chaco and no obvious indications that the depopulation of the canyon in the 13th century was caused by any specific cultural practices or natural events. Clearly there was a reason why these farming people eventually moved elsewhere, but the archaeological record has not yet produced compelling empirical evidence for what that reason might have been. Until such evidence appears, the legacy of Ancestral Pueblo society in Chaco should not be used as a cautionary story about socioeconomic failures in the modern world. PMID:25071220

  6. Prehistoric deforestation at Chaco Canyon?

    PubMed Central

    Wills, W. H.; Drake, Brandon L.; Dorshow, Wetherbee B.

    2014-01-01

    Ancient societies are often used to illustrate the potential problems stemming from unsustainable land-use practices because the past seems rife with examples of sociopolitical “collapse” associated with the exhaustion of finite resources. Just as frequently, and typically in response to such presentations, archaeologists and other specialists caution against seeking simple cause-and effect-relationships in the complex data that comprise the archaeological record. In this study we examine the famous case of Chaco Canyon, New Mexico, during the Bonito Phase (ca. AD 860–1140), which has become a prominent popular illustration of ecological and social catastrophe attributed to deforestation. We conclude that there is no substantive evidence for deforestation at Chaco and no obvious indications that the depopulation of the canyon in the 13th century was caused by any specific cultural practices or natural events. Clearly there was a reason why these farming people eventually moved elsewhere, but the archaeological record has not yet produced compelling empirical evidence for what that reason might have been. Until such evidence appears, the legacy of Ancestral Pueblo society in Chaco should not be used as a cautionary story about socioeconomic failures in the modern world. PMID:25071220

  7. Predictability of Turbulent Flow in Street Canyons

    NASA Astrophysics Data System (ADS)

    Lo, K. W.; Ngan, K.

    2015-08-01

    Although predictability is a subject of great importance in atmospheric modelling, there has been little research on urban boundary-layer flows. Here the predictability of street-canyon flow is examined numerically via large-eddy simulation of a unit-aspect-ratio canyon and neutrally stratified atmosphere. In spectral space there is indication of cascade-like behaviour away from the canyon at early times, but the error growth is essentially independent of scale inside the canyon; in physical space the error field is rather inhomogeneous and shows clear differences among the canyon, shear layer and inertial sublayer. The error growth is largely driven by the shear layer: errors generated above roof level are advected into the canyon while contributions from intermittent bursting and in situ development within the canyon play a relatively minor role. This work highlights differences between the predictability of urban flows and canonical turbulent flows and should be useful in developing modelling strategies for more realistic time-dependent urban flows.

  8. Flow dynamics around downwelling submarine canyons

    NASA Astrophysics Data System (ADS)

    Spurgin, J. M.; Allen, S. E.

    2014-05-01

    Flow dynamics around a downwelling submarine canyon were analysed with the Massachusetts Institute of Technology general circulation model. Blanes Canyon (Northwest Mediterranean) was used for topographic and initial forcing conditions. Fourteen scenarios were modelled with varying forcing conditions. Rossby number and Burger number were used to determine the significance of Coriolis acceleration and stratification (respectively) and their impacts on flow dynamics. A new non-dimensional parameter (?) was introduced to determine the significance of vertical variations in stratification. Some simulations do see brief periods of upwards displacement of water during the 10 day model period, however, the presence of the submarine canyon is found to enhance downwards advection of density in all model scenarios. High Burger numbers lead to negative vorticity and a trapped anticyclonic eddy within the canyon, as well as an increased density anomaly. Low Burger numbers lead to positive vorticity, cyclonic circulation and weaker density anomalies. Vertical variations in stratification affect zonal jet placement. Under the same forcing conditions, the zonal jet is pushed offshore in more uniformly stratified domains. Offshore jet location generates upwards density advection away from the canyon, while onshore jets generate downwards density advection everywhere within the model domain. Increasing Rossby values across the canyon axis, as well as decreasing Burger values, increase negative vertical flux at shelf break depth (150 m). Increasing Rossby numbers lead to stronger downwards advection of a passive tracer (nitrate) as well as stronger vorticity within the canyon. Results from previous studies were explained within this new dynamic framework.

  9. Flow dynamics around downwelling submarine canyons

    NASA Astrophysics Data System (ADS)

    Spurgin, J. M.; Allen, S. E.

    2014-10-01

    Flow dynamics around a downwelling submarine canyon were analysed with the Massachusetts Institute of Technology general circulation model. Blanes Canyon (northwestern Mediterranean) was used for topographic and initial forcing conditions. Fourteen scenarios were modelled with varying forcing conditions. Rossby and Burger numbers were used to determine the significance of Coriolis acceleration and stratification (respectively) and their impacts on flow dynamics. A new non-dimensional parameter (?) was introduced to determine the significance of vertical variations in stratification. Some simulations do see brief periods of upwards displacement of water during the 10-day model period; however, the presence of the submarine canyon is found to enhance downwards advection of density in all model scenarios. High Burger numbers lead to negative vorticity and a trapped anticyclonic eddy within the canyon, as well as an increased density anomaly. Low Burger numbers lead to positive vorticity, cyclonic circulation, and weaker density anomalies. Vertical variations in stratification affect zonal jet placement. Under the same forcing conditions, the zonal jet is pushed offshore in more uniformly stratified domains. The offshore jet location generates upwards density advection away from the canyon, while onshore jets generate downwards density advection everywhere within the model domain. Increasing Rossby values across the canyon axis, as well as decreasing Burger values, increase negative vertical flux at shelf break depth (150 m). Increasing Rossby numbers lead to stronger downwards advection of a passive tracer (nitrate), as well as stronger vorticity within the canyon. Results from previous studies are explained within this new dynamic framework.

  10. ewly discovered at the bottom of the Hudson Canyon, the largest submarine canyon off the eastern United States, is

    E-print Network

    Neimark, Alexander V.

    N ewly discovered at the bottom of the Hudson Canyon, the largest submarine canyon off the eastern the canyon revealed abnormally high levels of methane, while sonar data collected by the free sediment-covered continental margins and in Arctic tundra. The Hudson Canyon supports an abundant

  11. Rapid canyon formation by extreme floods

    NASA Astrophysics Data System (ADS)

    Lamb, M. P.; Mackey, B. H.; Lapotre, M. G.

    2012-12-01

    The formation of river gorges generally occurs over geomorphic timescales, with rates of river incision into bedrock infrequently exceeding millimeters per year. This is in contrast to relatively rare examples of bedrock canyons that have been cut in a matter of days or weeks by catastrophic floods. Here we report on several case studies of canyons inferred to have been cut by large magnitude, short-lived flood events. Canyon Lake Gorge, Texas, was cut ~ 10 m into jointed bedrock during a three-day historic flood event, illustrating that short lived floods can efficiently mobilize and transport large quantities of rock. New cosmogenic exposure dating of multiple features at Malad Gorge, Idaho, indicates that it was formed ~ 48 ka, equivalent to the age of Box Canyon located 18 km to the south, suggesting that flooding there was regional in scale. In all cases, we attribute extremely rapid canyon erosion (i.e., meters per day) to the dominance of plucking and toppling of jointed rock rather than the relatively slow process of fluvial abrasion. Large magnitude flows are inferred from the threshold required to topple blocks and transport boulders. The lack of upstream drainage-network development and the lack of fluvial abrasion features indicate the floods must have been short-lived. Canyons cut into plateau terrain by large magnitude, short duration floods appear to have distinctive morphologies including steep canyon headwalls with semi-circular planforms, suggesting flow focusing and toppling at the headwall, despite the largely flat initial topography. In contrast, neighboring canyons undergoing active fluvial abrasion tend to show potholes, polished and fluted rock, headwalls that are pointed in planform, and more gradual knickzones extending into well-developed drainage networks upstream. Modeling suggests that the rate of canyon cutting by large-scale floods in jointed rock may be limited only by the sediment transport capacity of the flow.

  12. Mars Science Laboratory at Canyon

    NASA Technical Reports Server (NTRS)

    2003-01-01

    December 2, 2003

    NASA's Mars Science Laboratory travels near a canyon on Mars in this artist's concept. The mission is under development for launch in 2009 and a precision landing on Mars in 2010.

    Once on the ground, the Mars Science Laboratory would analyze dozens of samples scooped up from the soil and cored from rocks as it explores with greater range than any previous Mars rover. It would investigate the past or present ability of Mars to support life. NASA is considering nuclear energy for powering the rover to give it a long operating lifespan.

    NASA's Jet Propulsion Laboratory, Pasadena, Calif., is managing development of the Mars Smart Laboratory for the NASA Office of Space Science, Washington, D.C.

  13. Wintertime meteorology of the Grand Canyon region

    SciTech Connect

    Whiteman, C.D.

    1992-09-01

    The Grand Canyon region of the American Southwest is an interesting region meteorologically, but because of its isolated location, the lack of major population centers in the region, and the high cost of meteorological field experiments, it has historically received little observational attention. In recent years, however, attention has been directed to episodes of visibility degradation in many of the US National parks, and two recent field studies focused on this visibility problem have greatly increased the meteorological data available for the Grand Canyon region. The most recent and comprehensive of these studies is the Navajo Generating Station Winter Visibility Study of 1989--90. This study investigated the sources of visibility degradation in Grand Canyon National Park and the meteorological mechanisms leading to low visibility episodes. In this paper we present analyses of this rich data set to gain a better understanding of the key wintertime meteorological features of the Grand Canyon region.

  14. Different Views of the Grand Canyon

    NASA Astrophysics Data System (ADS)

    Elders, Wilfred A.

    Each year the spectacular scenery of the Grand Canyon of Arizona awes its more than 4,000,000 visitors. Just as its enormous scale dwarfs our human sense of space, its geology also dwarfs our human sense of time. Perhaps here, more than anywhere else on the planet, we can experience a sense of ``Deep Time.'' The colorful rocks exposed in the vertical walls of the canyon display a span of 1.8 billion years of Earth's history [Beus and Morales, 2003]. But wait! There is a different view! According to Vail [2003], this time span is only 6,000 years and the Grand Canyon and its rocks are a record of the Biblical 6 days of creation and Noah's flood. During a visit to Grand Canyon, in August 2003, I learned that Vail's book, Grand Canyon: A Different View, is being sold within the National Park. The author and compiler of Grand Canyon: A Different View is a Colorado River guide who is well acquainted with the Grand Canyon at river level. He has produced a book with an attractive layout and beautiful photographs. The book is remarkable because it has 23 co-authors, all male, who comprise a veritable ``Who's Who'' in creationism. For example, Henry Morris and John Whitcomb, the authors of the seminal young Earth creationist text, The Genesis Flood [Whitcomb and Morris, 1961], each contribute a brief introduction. Each chapter of Grand Canyon: A Different View begins with an overview by Vail, followed by brief comments by several contributors that ``have been peer reviewed to ensure a consistent and Biblical perspective.'' This perspective is strict Biblical literalism.

  15. Geomorphic clues to the Martian volatile inventory: Landslides

    NASA Technical Reports Server (NTRS)

    Pieri, D.; Kirkpatrick, A.

    1984-01-01

    Eight landslide locales were selected in Valles Marineris for preliminary geomorphological mapping. Four main suites of morphological features were identified. In four order outward from the head scarp they are: (1) large ridges in head area, transverse to movement direction, probably slump blocks or pieces of wall that fell or toppled, possibly backward rotated; (2) smaller ridges, convex toward distal edge of slides, many with lobate pattern, some possibly step like scarps rather than ridges; (3) thin, sheet like debris cover, forms discrete fan shaped lobe with edge scarps unconfined; and (4) low transverse, continuous ridges (possibly folds) found at distal edge of slides, where debris appears to have encountered obstructions (e.g., opposing canyon walls), but not all confined slides exhibit this feature. Any one landslide can possess all or some of these features. Slides in the western Valles Marineris are more complex and show more variety than those in the eastern part.

  16. Wilmington Submarine Canyon: a marine fluvial-like system.

    USGS Publications Warehouse

    McGregor, B.; Stubblefield, W.L.; Ryan, William B. F.; Twichell, D.C.

    1982-01-01

    Midrange sidescan sonar data show that a system of gullies and small channels feeds into large submarine canyons on the Middle Atlantic Continental Slope of the US. The surveyed canyons all have relatively flat floors, but they have different channel morphologies. Wilmington Canyon has a meandering channel that extends down the Continental Slope and across the Continental Rise, whereas two canyons south of Wilmington Canyon have straight channels that trend directly downslope onto the rise. The morphology of these submarine canyon systems is remarkably similar to that of terrestrial fluvial systems.-Authors

  17. Origin of Florida Canyon and the role of spring sapping on the formation of submarine box canyons

    USGS Publications Warehouse

    Paull, Charles K.; Spiess, Fred N.; Curray, Joseph R.; Twichell, David C.

    1990-01-01

    Florida Canyon, one of a series of major submarine canyons on the southwestern edge of the Florida Platform, was surveyed using GLORIA, SeaBeam, and Deep-Tow technologies, and it was directly observed during three DSRV Alvin dives. Florida Canyon exhibits two distinct morphologies: a broad V-shaped upper canyon and a deeply entrenched, flat-floored, U-shaped lower canyon. The flat- floored lower canyon extends 20 km into the Florida Platform from the abyssal Gulf. The lower canyon ends abruptly at an ?3 km in diameter semicircular headwall that rises 750 m with a >60° slope angle to the foot of the upper canyon. The sides of the lower canyon are less steep than its headwall and are characterized by straight faces that occur along preferred orientations and indicate a strong joint control. The upper canyon is characterized by a gently sloping, straight V-shaped central valley cut into a broad terrace. The flat floor of the upper canyon continues as terraces along the upper walls of the lower canyon. On the flanks of the upper canyon, there are five >50-m-deep, >0.5-km-wide, closed sink-hole-like depressions which indicate subsurface dissolution within the platform. The origin of the lower canyon is difficult to explain with traditional models of submarine canyon formation by external physical processes. The movement of ground water, probably with high salinities and reduced compounds along regional joints, may have focused the corrosive force of submarine spring sapping at the head of the lower canyon to produce the canyon's present shape.

  18. 43. and Design, Grand Canyon National Park, dated August 23, ...

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

    43. and Design, Grand Canyon National Park, dated August 23, 1934, and September 17, 1934 (original located at Federal Records Center, Denver, Colorado, #113/3084-set of 2) SEWAGE PLANT ADDITION. - Water Reclamation Plant, Grand Canyon, Coconino County, AZ

  19. 75 FR 34476 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ...Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior...for the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group is to advise and to provide...

  20. Contemporary sediment-transport processes in submarine canyons.

    PubMed

    Puig, Pere; Palanques, Albert; Martín, Jacobo

    2014-01-01

    Submarine canyons are morphological incisions into continental margins that act as major conduits of sediment from shallow- to deep-sea regions. However, the exact mechanisms involved in sediment transfer within submarine canyons are still a subject of investigation. Several studies have provided direct information about contemporary sedimentary processes in submarine canyons that suggests different modes of transport and various triggering mechanisms. Storm-induced turbidity currents and enhanced off-shelf advection, hyperpycnal flows and failures of recently deposited fluvial sediments, dense shelf-water cascading, canyon-flank failures, and trawling-induced resuspension largely dominate present-day sediment transfer through canyons. Additionally, internal waves periodically resuspend ephemeral deposits within canyons and contribute to dispersing particles or retaining and accumulating them in specific regions. These transport processes commonly deposit sediments in the upper- and middle-canyon reaches for decades or centuries before being completely or partially flushed farther down-canyon by large sediment failures. PMID:23937169

  1. Grand Canyon Humpback Chub Population Improving

    USGS Publications Warehouse

    Andersen, Matthew E.

    2007-01-01

    The humpback chub (Gila cypha) is a long-lived, freshwater fish found only in the Colorado River Basin. Physical adaptations-large adult body size, large predorsal hump, and small eyes-appear to have helped humpback chub evolve in the historically turbulent Colorado River. A variety of factors, including habitat alterations and the introduction of nonnative fishes, likely prompted the decline of native Colorado River fishes. Declining numbers propelled the humpback chub onto the Federal list of endangered species in 1967, and the species is today protected under the Endangered Species Act of 1973. Only six populations of humpback chub are currently known to exist, five in the Colorado River Basin above Lees Ferry, Ariz., and one in Grand Canyon, Ariz. The U.S. Geological Survey's Grand Canyon Monitoring and Research Center oversees monitoring and research activities for the Grand Canyon population under the auspices of the Glen Canyon Dam Adaptive Management Program (GCDAMP). Analysis of data collected through 2006 suggests that the number of adult (age 4+ years) humpback chub in Grand Canyon increased to approximately 6,000 fish in 2006, following an approximate 40-50 percent decline between 1989 and 2001. Increasing numbers of adult fish appear to be the result of steadily increasing numbers of juvenile fish reaching adulthood beginning in the mid- to late-1990s and continuing through at least 2002.

  2. Air pollutant transport in a street canyon

    SciTech Connect

    Luke Chen; Hsu-Cheng Chang

    1996-12-31

    An air pollutant (CO) distribution in a typical street canyon is simulated to evaluate pedestrian exposure. In this study, we consider factors those may affect the pollutant distribution in a typical street canyon. The considered factors include aspect ratio of a street canyon, atmospheric stability, traffic load and turbulent buoyancy effect. A two-dimensional domain that includes suburban roughness and urban street canyon is considered. The factors such as atmospheric stability, traffic load and turbulent buoyancy are imposed through the associated boundary conditions. With numerical simulation, the critical aspect ration of a street canyon the includes two vortices and results in pollutant accumulation are found. The buoyant effect is found to raise the same pollutant concentration up to the position higher than the results come out from the case without buoyancy. The pedestrian exposure to the street air pollutant under various traffic loads and atmospheric stability are evaluated. This study conclude that the local building regulations that specify the building height/street width ratio will not cause significant pedestrian exposure to the street air pollution in most of traffic loads and atmospheric stability conditions.

  3. 77 FR 22801 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation... Management Work Group (AMWG) makes recommendations to the Secretary of the Interior concerning Glen Canyon... AMP includes a Federal advisory committee, the AMWG, a technical work group, a Grand Canyon...

  4. 78 FR 21415 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group..., the AMWG, a technical work group, a Grand Canyon Monitoring and Research Center, and...

  5. 77 FR 9265 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-16

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group... Federal advisory committee, the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and...

  6. 77 FR 43117 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-23

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group... Federal advisory committee, the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and...

  7. 27 CFR 9.152 - Malibu-Newton Canyon.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Malibu-Newton Canyon. 9.152 Section 9.152...Viticultural Areas § 9.152 Malibu-Newton Canyon. (a) Name. The name of...described in this petition is “Malibu-Newton Canyon.” (b) Approved maps....

  8. Calcareous nannoplankton and benthic foraminiferal assemblages from the Nazar Canyon

    E-print Network

    , Portugal E-mail: catarina.guerreiro@hidrografico.pt Abstract. Submarine canyons are assumed to play presently in process at the Institute of Oceanography (IO). 1. Introduction Active submarine canyons, a gouf-type canyon, is one of Europe's largest submarine valleys, located on the central part

  9. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Grand Canyon National Park. 7... SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.4 Grand Canyon National Park. (a) Commercial... motor vehicles to Grand Canyon National Park contained in § 5.4 of this chapter shall be subject to...

  10. Dispersion Mechanisms In A Street Canyon.

    NASA Astrophysics Data System (ADS)

    Caton, F.; Britter, R. E.; Dalziel, S.

    In this article, we investigate experimentally and analytically the dispersion mecha- nisms of a passive tracer in a two-dimensional street canyon model. The central point concerns the concentration transfer between the street and the external flow. In con- trast to previous studies, the mass fluxes are not only inferred from mean concentration measurements but also directly measured thanks to a Particle Tracking Velocimetry technique. Visualizations of the evolution of the concentration field evidence the role of the shear layer at the top of the street canyon. Analytical transfer and dispersion models are derived, exhibiting the importance of external turbulence properties on the transfer. Those models are in excellent agreement with the measurements. The results presented in this article strongly suggest that the transfer in a street canyon does depend on the structure of the incoming turbulence, i.e. on the local stability conditions and on the upwind build-up.

  11. Candor Chasma - Massive (non-layered) material expos

    NASA Technical Reports Server (NTRS)

    1998-01-01

    One of the most striking discoveries of the Mars Global Surveyor mission has been the identification of thousands of meters/feet of layers within the wall rock of the enormous martian canyon system, Valles Marineris.

    Valles Marineris was first observed in 1972 by the Mariner 9 spacecraft, from which the troughs get their name: Valles--valleys, Marineris--Mariner.

    Some hints of layering in both the canyon walls and within some deposits on the canyon floors were seen in Mariner 9 and Viking orbiter images from the 1970s. The Mars Orbiter Camera on board Mars Global Surveyor has been examining these layers at much higher resolution than was available previously.

    MOC images led to the realization that there are layers in the walls that go down to great depths. An example of the wall rock layers can be seen in MOC image 8403, shown above (C).

    MOC images also reveal amazing layered outcrops on the floors of some of the Valles Marineris canyons. Particularly noteworthy is MOC image 23304 (D, above), which shows extensive, horizontally-bedded layers exposed in buttes and mesas on the floor of western Candor Chasma. These layered rocks might be the same material as is exposed in the chasm walls (as in 8403--C, above), or they might be rocks that formed by deposition (from water, wind, and/or volcanism) long after Candor Chasma opened up.

    In addition to layered materials in the walls and on the floors of the Valles Marineris system, MOC images are helping to refine our classification of geologic features that occur within the canyons. For example, MOC image 25205 (E, above), shows the southern tip of a massive, tongue-shaped massif (a mountainous ridge) that was previously identified as a layered deposit. However, this MOC image does not show layering. The material has been sculpted by wind and mass-wasting--downslope movement of debris--but no obvious layers were exposed by these processes.

    Valles Marineris a fascinating region on Mars that holds much potential to reveal information about the early history and evolution of the red planet. The MOC Science Team is continuing to examine the wealth of new data and planning for new Valles Marineris targets once the Mapping Phase of the Mars Global Surveyor mission commences in March 1999.

    This image: Massive (non-layered) material exposed in central Candor Chasma. MOC image 25205 subframe shown at 11.7 meters (38.4 feet) per pixel resolution. Image shows the southern tip of a massive 'interior deposit' that points like a giant tongue from Ophir Chasma (to the north) down into the center of Candor Chasma. The ridged and grooved bright unit is the 'interior deposit'. South of this ridged unit is a low elevation surface mantled by dark dunes and sand. Image covers an area approximately 5.7 by 5.7 kilometers (3.5 x 3.5 miles). North is approximately up, illumination is from the lower right. Image 25205 was obtained during Mars Global Surveyor's 252nd orbit at 2:45 p.m. (PDT) on April 20, 1998.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  12. HELLS CANYON STUDY AREA, OREGON AND IDAHO.

    USGS Publications Warehouse

    Simmons, George C.; Close, Terry J.

    1984-01-01

    The Hells Canyon study area occupies nearly 950 sq mi along and near Hells Canyon of the Snake River in northeast Oregon and west-central Idaho. Geologic, geochemical, aeromagnetic, and mine and prospect investigations to determine the mineral-resource potential of the area were carried out. As a result, 42 sq mi or about 4 percent of the lands, in 21 separate areas, were classified as having probable or substantiated resource potential for base and precious metals, molybdenum, and tungsten. No energy resource potential was identified in this study.

  13. Let's Bet on Sediments! Hudson Canyon Cruise--Grades 9-12. Focus: Sediments of Hudson Canyon.

    ERIC Educational Resources Information Center

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    These activities are designed to teach about the sediments of Hudson Canyon. Students investigate and analyze the patterns of sedimentation in the Hudson Canyon, observe how heavier particles sink faster than finer particles, and learn that submarine landslides are avalanches of sediment in deep ocean canyons. The activity provides learning…

  14. Morphology of Neptune Node Sites, Barkley Canyon, Cascadia Margin

    NASA Astrophysics Data System (ADS)

    Lundsten, E. M.; Anderson, K.; Paull, C. K.; Caress, D. W.; Thomas, H. J.; Riedel, M.

    2014-12-01

    High-resolution multibeam bathymetry and chirp seismic reflection profiles collected with MBARI's mapping autonomous underwater vehicle reveal the fine-scale morphology and shallow seafloor structure of the flanks and floor of Barkley Canyon on the Cascadia continental margin off British Columbia. The surveys characterize the environment surrounding three nodes on the Neptune Canada cabled observatory located within the canyon. The canyon floor between 960 and 1020 m water depth lacks channeling and contains ? 24 m of acoustically uniform sediment fill, which is ponded between the canyon's steep sidewalls. The fill overlies a strong reflector that outlines an earlier, now buried, canyon floor channel system. Debris flow tongues contain meter scale blocks sticking-up through the fill. Apparently the present geomorphology surrounding the Canyon Axis node in 985 m is attributable to local debris flows, rather than organized down canyon processes. In the survey area the canyon sidewalls extend ~300 m up and in places the slope of the canyons sides exceed 40°. Both the Hydrate node in 870 m water depths and the Mid-Canyon node at 890 m are located on a headland that forms intermediate depth terraces on the canyon's western flank. While the seafloor immediately surrounding the Mid-canyon node is smooth, the Hydrate node is marked by 10 circular mounds up to 2 m high and 10 m in diameter, presumable associated with hydrate formation. Although wedges of sediment drape occur in places on the canyon sides, the chirp profiles show no detectible sediment drape at either node site and suggest these nodes are situated on older, presumably pre-Quaternary strata. The lack of reflectors in the chirp profiles indicates most of the canyon's sidewalls are largely sediment-bare. Lineations in the bathymetry mark the exposed edges of truncated beds. Rough, apparently fresh textures, within slide scarps show the importance of erosion on the development of the canyon flanks.

  15. Geohydrology of White Rock Canyon of the Rio Grande from Otowi to Frijoles Canyon

    SciTech Connect

    Purtymun, W.D.; Peters, R.J.; Owens, J.W.

    1980-12-01

    Twenty-seven springs discharge from the Totavi Lentil and Tesuque Formation in White Rock Canyon. Water generally acquires its chemical characteristics from rock units that comprise the spring aquifer. Twenty-two of the springs are separated into three groups of similar aquifer-related chemical quality. The five remaining springs make up a fourth group with a chemical quality that differs due to localized conditions in the aquifer. Localized conditions may be related to recharge or discharge in or near basalt intrusion or through faults. Streams from Pajarito, Ancho, and Frijoles Canyons discharge into the Rio Grande in White Rock Canyon. The base flow in the streams is from springs. Sanitary effluent in Mortandad Canyon from the treatment plant at White Rock also reaches the Rio Grande.

  16. North Atlantic slope and canyon study. Volume 1. Executive summary

    SciTech Connect

    Butman, B.

    1986-12-01

    A field program to investigate the currents and sediment transport along the outershelf and upper slope along the southern flank of Georges Bank was conducted between 1980 and 1984. A major part of the field experiment was conducted in Lydonia Canyon, a large submarine canyon which cuts northward about 20 km into the continental shelf from the shelfbreak. A smaller experiment was conducted in Oceanographer Canyon to compare the currents in these two major canyons. The long-term current observations made in Lydonia and Oceanographer Canyons show that the current regime in these topographic features differs from the adjacent slope, and between canyons. Sediments near the head (depths shallower than about 600 m) in both Lydonia and Oceanographer are frequently resuspended. This frequent resuspension may allow the sediments to strip pollutants from the water column. Currents in Oceanographer Canyon are stronger and the sediments coarser than in Lydonia at comparable depths.

  17. 2 Grjota Valles and implications for flood sediment deposition on Mars 3 Devon M. Burr1

    E-print Network

    Kah, Linda

    Month 2006. 6 [1] Grjota´ Valles is one of Mars' four Amazonian-aged, 7 fissure-headed, catastrophic´ Valles (Figure 1) (IAU provisional name) is 31 one of Mars' Amazonian-aged catastrophic flood channels2 Grjota´ Valles and implications for flood sediment deposition on Mars 3 Devon M. Burr1 and Alex H

  18. Map Your Way to the Grand Canyon

    ERIC Educational Resources Information Center

    Yoder, Holly

    2005-01-01

    In the introductory assignment, each randomly assigned group spends about 10 to 15 minutes at each station. The author incorporates as much sensory stimulation in the activity as possible. At the first station, students view a PowerPoint show from a geology class the author participated in at the Grand Canyon. At station two, students look at a…

  19. 78 FR 7775 - Boulder Canyon Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    .... \\1\\ 75 FR 57912 (September 23, 2010). \\2\\ 133 FERC ] 62,229. The proposed BCP electric service base... in power rate adjustments (10 CFR part 903) were published on September 18, 1985 (50 FR 87835... Area Power Administration Boulder Canyon Project AGENCY: Western Area Power Administration, DOE....

  20. Bryce Canyon and Grand Staircase-Escalante

    USGS Multimedia Gallery

    In the foreground are sandstone hoodoos and in the background is the Grand Staircase-Escalante National Monument, which is managed by the Bureau of Land Management. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars...

  1. 76 FR 56430 - Boulder Canyon Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-13

    ... Fiscal Year (FY) 2012 Base Charge and Rates (Rates) for Boulder Canyon Project (BCP) electric service... Project. BCP electric service rates are adjusted annually using an existing rate formula established on... parties in determining the Rates: 1. A Federal Register notice was published on February 14, 2011 (76...

  2. 77 FR 2533 - Boulder Canyon Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... Boulder Canyon Project (BCP) electric service base charge and rates. The current base charge and rates... composite rate is 20.45 mills/kWh. \\1\\ 75 FR 57912 (Sept. 23, 2010). \\2\\ 133 FERC ] 62,229. The proposed BCP... 18, 1985 (50 FR 87835). Availability of Information All brochures, studies, comments,...

  3. Sandbar growth Grand Canyon following controlled flood

    USGS Multimedia Gallery

    Picture showing the increased size of the sandbar after the November 2012 controlled flood from the Glen Canyon Dam. This location is 65 miles downstream from Lees Ferry and the view is looking downstream. These and additional photographs depicting the results of the recent controlled floods can be ...

  4. Navajo generating plant and Grand Canyon haze

    SciTech Connect

    Norris, J.E.

    1991-01-15

    This article examines the question of whether the Navajo generating plant pollution is contributing to pollution of the air in the Grand Canyon region. The topics include the regulatory context of the plant, the experiment known as the Winter Haze Intensive Tracer Experiment (WHITEX), the National Research Council evaluation of the WHITEX, and The Navajo Generating Station Visibility Study.

  5. The Colorado River in the Grand Canyon.

    ERIC Educational Resources Information Center

    Speece, Susan

    1991-01-01

    An assessment of the water quality of the Colorado River in the Grand Canyon was made, using the following parameters: dissolved oxygen, water temperature, hydrogen ion concentration, total dissolved solids, turbidity, and ammonium/nitrogen levels. These parameters were used to provide some clue as to the "wellness" and stability of the aquatic…

  6. Anatomy of La Jolla submarine canyon system; offshore southern California

    USGS Publications Warehouse

    Paull, C.K.; Caress, D.W.; Lundsten, E.; Gwiazda, R.; Anderson, K.; McGann, M.; Conrad, J.; Edwards, B.; Sumner, E.J.

    2013-01-01

    An autonomous underwater vehicle (AUV) carrying a multibeam sonar and a chirp profiler was used to map sections of the seafloor within the La Jolla Canyon, offshore southern California, at sub-meter scales. Close-up observations and sampling were conducted during remotely operated vehicle (ROV) dives. Minisparker seismic-reflection profiles from a surface ship help to define the overall geometry of the La Jolla Canyon especially with respect to the pre-canyon host sediments. The floor of the axial channel is covered with unconsolidated sand similar to the sand on the shelf near the canyon head, lacks outcrops of the pre-canyon host strata, has an almost constant slope of 1.0° and is covered with trains of crescent shaped bedforms. The presence of modern plant material entombed within these sands confirms that the axial channel is presently active. The sand on the canyon floor liquefied during vibracore collection and flowed downslope, illustrating that the sediment filling the channel can easily fail even on this gentle slope. Data from the canyon walls help constrain the age of the canyon and extent of incision. Horizontal beds of moderately cohesive fine-grained sediments exposed on the steep canyon walls are consistently less than 1.232 million years old. The lateral continuity of seismic reflectors in minisparker profiles indicate that pre-canyon host strata extend uninterrupted from outside the canyon underneath some terraces within the canyon. Evidence of abandoned channels and point bar-like deposits are noticeably absent on the inside bend of channel meanders and in the subsurface of the terraces. While vibracores from the surface of terraces contain thin (< 10 cm) turbidites, they are inferred to be part of a veneer of recent sediment covering pre-canyon host sediments that underpin the terraces. The combined use of state of the art seafloor mapping and exploration tools provides a uniquely detailed view of the morphology within an active submarine canyon.

  7. Creationism in the Grand Canyon, Texas Textbooks

    NASA Astrophysics Data System (ADS)

    Folger, Peter

    2004-01-01

    AGU President Bob Dickinson, together with presidents of six other scientific societies, have written to Joseph Alston, Superintendent of Grand Canyon National Park, pointing out that a creationist book, The Grand Canyon: A Different View, is being sold in bookstores within the borders of the park as a scientific explanation about Grand Canyon geologic history. President Dickinson's 16 December letter urges that Alston clearly separate The Grand Canyon: A Different View from books and materials that discuss the legitimate scientific understanding of the origin of the Grand Canyon. The letter warns the Park Service against giving the impression that it approves of the anti-science movement known as young-Earth creationism, or that it endorses the advancement of religious tenets disguised as science. The text of the letter is on AGU's Web site http://www.agu.org/sci_soc/policy/sci_pol.html. Also, this fall, AGU sent an alert to Texas members about efforts by intelligent design creationists aimed at weakening the teaching of biological evolution in textbooks used in Texas schools. The alert pointed scientists to a letter, drafted by AGU, together with the American Institute of Physics, the American Physical Society, the Optical Society of America, and the American Astronomical Society, that urged the Texas State Board of Education to adopt textbooks that presented only accepted, peer-reviewed science and pedagogical expertise. Over 550 scientists in Texas added their names to the letter (http://www.agu.org/sci_soc/policy/texas_textbooks.pdf ), sent to the Board of Education on 1 November prior to their vote to adopt a slate of new science textbooks. The Board voted 11-5 in favor of keeping the textbooks free of changes advocated by groups supporting intelligent design creationism.

  8. Athabasca Valles, Mars: a lava-draped channel system.

    PubMed

    Jaeger, W L; Keszthelyi, L P; McEwen, A S; Dundas, C M; Russell, P S

    2007-09-21

    Athabasca Valles is a young outflow channel system on Mars that may have been carved by catastrophic water floods. However, images acquired by the High-Resolution Imaging Science Experiment camera onboard the Mars Reconnaissance Orbiter spacecraft reveal that Athabasca Valles is now entirely draped by a thin layer of solidified lava-the remnant of a once-swollen river of molten rock. The lava erupted from a fissure, inundated the channels, and drained downstream in geologically recent times. Purported ice features in Athabasca Valles and its distal basin, Cerberus Palus, are actually composed of this lava. Similar volcanic processes may have operated in other ostensibly fluvial channels, which could explain in part why the landers sent to investigate sites of ancient flooding on Mars have predominantly found lava at the surface instead. PMID:17885126

  9. Athabasca Valles, Mars: A lava-draped channel system

    USGS Publications Warehouse

    Jaeger, W.L.; Keszthelyi, L.P.; McEwen, A.S.; Dundas, C.M.; Russell, P.S.

    2007-01-01

    Athabasca Valles is a young outflow channel system on Mars that may have been carved by catastrophic water floods. However, images acquired by the High-Resolution Imaging Science Experiment camera onboard the Mars Reconnaissance Orbiter spacecraft reveal that Athabasca Valles is now entirely draped by a thin layer of solidified lava - the remnant of a once-swollen river of molten rock. The lava erupted from a fissure, inundated the channels, and drained downstream in geologically recent times. Purported ice features in Athabasca Valles and its distal basin, Cerberus Palus, are actually composed of this lava. Similar volcanic processes may have operated in other ostensibly fluvial channels, which could explain in part why the landers sent to investigate sites of ancient flooding on Mars have predominantly found lava at the surface instead.

  10. Big Canyon Creek Ecological Restoration Strategy.

    SciTech Connect

    Rasmussen, Lynn; Richardson, Shannon

    2007-10-01

    He-yey, Nez Perce for steelhead or rainbow trout (Oncorhynchus mykiss), are a culturally and ecologically significant resource within the Big Canyon Creek watershed; they are also part of the federally listed Snake River Basin Steelhead DPS. The majority of the Big Canyon Creek drainage is considered critical habitat for that DPS as well as for the federally listed Snake River fall chinook (Oncorhynchus tshawytscha) ESU. The Nez Perce Soil and Water Conservation District (District) and the Nez Perce Tribe Department of Fisheries Resources Management-Watershed (Tribe), in an effort to support the continued existence of these and other aquatic species, have developed this document to direct funding toward priority restoration projects in priority areas for the Big Canyon Creek watershed. In order to achieve this, the District and the Tribe: (1) Developed a working group and technical team composed of managers from a variety of stakeholders within the basin; (2) Established geographically distinct sub-watershed areas called Assessment Units (AUs); (3) Created a prioritization framework for the AUs and prioritized them; and (4) Developed treatment strategies to utilize within the prioritized AUs. Assessment Units were delineated by significant shifts in sampled juvenile O. mykiss (steelhead/rainbow trout) densities, which were found to fall at fish passage barriers. The prioritization framework considered four aspects critical to determining the relative importance of performing restoration in a certain area: density of critical fish species, physical condition of the AU, water quantity, and water quality. It was established, through vigorous data analysis within these four areas, that the geographic priority areas for restoration within the Big Canyon Creek watershed are Big Canyon Creek from stream km 45.5 to the headwaters, Little Canyon from km 15 to 30, the mainstem corridors of Big Canyon (mouth to 7km) and Little Canyon (mouth to 7km). The District and the Tribe then used data collected from the District's stream assessment and inventory, utilizing the Stream Visual Assessment Protocol (SVAP), to determine treatment necessary to bring 90% of reaches ranked Poor or Fair through the SVAP up to good or excellent. In 10 year's time, all reaches that were previously evaluated with SVAP will be reevaluated to determine progress and to adapt methods for continued success. Over 400 miles of stream need treatment in order to meet identified restoration goals. Treatments include practices which result in riparian habitat improvements, nutrient reductions, channel condition improvements, fish habitat improvements, invasive species control, water withdrawal reductions, improved hydrologic alterations, upland sediment reductions, and passage barrier removal. The Nez Perce Soil and Water Conservation District (District) and the Nez Perce Tribe Department of Fisheries Resource Management Watershed Division (Tribe) developed this document to guide restoration activities within the Big Canyon Creek watershed for the period of 2008-2018. This plan was created to demonstrate the ongoing need and potential for anadromous fish habitat restoration within the watershed and to ensure continued implementation of restoration actions and activities. It was developed not only to guide the District and the Tribe, but also to encourage cooperation among all stakeholders, including landowners, government agencies, private organizations, tribal governments, and elected officials. Through sharing information, skills, and resources in an active, cooperative relationships, all concerned parties will have the opportunity to join together to strengthen and maintain a sustainable natural resource base for present and future generations within the watershed. The primary goal of the strategy is to address aquatic habitat restoration needs on a watershed level for resident and anadromous fish species, promoting quality habitat within a self-sustaining watershed. Seven objectives have been developed to support this goal: (1) Identify factors limiting quality

  11. Hydraulics of floods upstream of horseshoe canyons and waterfalls

    NASA Astrophysics Data System (ADS)

    Lapotre, Mathieu G. A.; Lamb, Michael P.

    2015-07-01

    Horseshoe waterfalls are ubiquitous in natural streams, bedrock canyons, and engineering structures. Nevertheless, water flow patterns upstream of horseshoe waterfalls are poorly known and likely differ from the better studied case of a one-dimensional linear step because of flow focusing into the horseshoe. This is a significant knowledge gap because the hydraulics at waterfalls controls sediment transport and bedrock incision, which can compromise the integrity of engineered structures and influence the evolution of river canyons on Earth and Mars. Here we develop new semiempirical theory for the spatial acceleration of water upstream of, and the cumulative discharge into, horseshoe canyons and waterfalls. To this end, we performed 110 numerical experiments by solving the 2-D depth-averaged shallow-water equations for a wide range of flood depths, widths and discharges, and canyon lengths, widths and bed gradients. We show that the upstream, normal flow Froude number is the dominant control on lateral flow focusing and acceleration into the canyon head and that focusing is limited when the flood width is small compared to a cross-stream backwater length scale. In addition, for sheet floods much wider than the canyon, flow focusing into the canyon head leads to reduced discharge (and drying in cases) across the canyon sidewalls, which is especially pronounced for canyons that are much longer than they are wide. Our results provide new expectations for morphodynamic feedbacks between floods and topography, and thus canyon formation.

  12. Workshop on recent research in the Valles caldera

    SciTech Connect

    Heiken, G.

    1985-02-01

    Over the last 5 years, there has been increased interest in the geology of the Jemez Mountains volcanic field, New Mexico. Of special interest is the Toledo-Valles caldera complex, which is targeted for research coring as part of the Continental Scientific Drilling Program. The general topics covered in this workshop were (1) hydrothermal systems and rock-water interactions, (2) volcanology and structural framework of the Jemez volcanic field, (3) determining the presence or absence of melt below the Valles caldera, and (4) deep coring and drilling technology. Separate abstracts were prepared for each presentation.

  13. Crustal Fractures of Ophir Planum

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 29 April 2002) The Science This THEMIS image covers a tract of plateau territory called Ophir Planum. The most obvious features in this scene are the fractures (ranging from 1 to 5 km wide) running from the upper left to lower right. Localized rifting and deep-seated tension fracturing of the crust probably formed these cracks. The wall rock displayed in the upper part of the cliffs appears to be layered. The southwest-facing wall of the largest and uppermost fracture has classic spur and gully topography. This type of topography is created by differing amounts of erosion. Also seen in this image are some scattered impact craters and some dark wind streaks in the lower right. The Ophir Planum plateau separates two separate smaller canyon systems, not visible in this image, (Candor Chasma to the north and Melas Chasma to the south) in the Valles Marineris canyon complex. The whole Valles Marineris canyon system extends some 4,000 km across the equatorial realms of Mars. For comparison, this would stretch from New York City to San Francisco. The Story Plateaus and spurs might make you think of cowboys on the open plain. 'Spurs' in this context, however, are simply ridges that can be seen on the side of the southwest-facing wall of the large fracture that splits the terrain. Gullies stretch down this slope as well. Both of these features are caused by erosion, which is a mild force of change compared to whatever tension cracked the crust and ripped apart the land. The wall rock displayed in the upper part of the cliffs appears to be layered, suggesting that different kinds of rocks and minerals can be found in each banded zone. The Ophir Planum plateau separates two separate canyon systems in the Valles Marineris complex, the largest canyon in the solar system. If Valles Marineris were on Earth, it would stretch from New York City all the way to San Francisco. That will give you some idea of the geological forces that have acted upon the planet over time. Look for scattered impact craters and some dark wind streaks in the deep dark terrain (lower right) as well.

  14. Sedimentary processes in the middle Nazaré Canyon

    NASA Astrophysics Data System (ADS)

    Masson, D. G.; Huvenne, V. A. I.; de Stigter, H. C.; Arzola, R. G.; LeBas, T. P.

    2011-12-01

    Nazaré Canyon extends from a water depth of 50 m near the Portuguese coast to 5000 m at the edge of the Iberian Abyssal Plain. The system is not connected to a modern river and instead obtains its present day sediment input by capture of along-shelf sediment transport. Much of this sediment is deposited in the middle canyon between about 2700 and 3800 m. However, the middle canyon is a highly heterogeneous environment, with areas of both high and low sedimentation rates, exposed rock outcrop, erosion and stable and unstable slopes in close juxtaposition. This paper explores how the various sedimentary processes interact to create the observed heterogeneous canyon environment, which will influence benthic biodiversity in the canyon. Seafloor heterogeneity is investigated using a nested approach to data interpretation, using local high-resolution data to calibrate regional lower resolution data. Six different data types, ship and ROV-mounted swath bathymetry, 30 kHz sidescan sonar images, sediment cores, seafloor video/photographs and current metre/acoustic backscatter data, were incorporated into the analysis. The main morphological characteristic of the middle canyon is a narrow, steep-sided, axial channel flanked by gently sloping terraces. Small-scale landsliding, active at the present day, is the main process that exposes a variety of substrates, ranging from semi-consolidated Holocene sediments to rock of probable Mesozoic age, on the steep axial channel walls. The axial channel floor is characterised in part by large-scale sediment bedforms and in part by landslide debris, suggesting some reworking of landslide debris by currents within the channel. The terraces are interpreted as inner levees with high sedimentation rates. Cores show a dominantly muddy sequence interrupted by thin turbidite sands emplaced on decadal to centennial timescales. The fine-grained sedimentation is the product of continuous settling from fine-grained flows that range from gravity currents to lateral advection of nepheloid layers. The close proximity of areas of high sedimentation and erosion creates a highly heterogeneous seafloor, with the highest heterogeneity on the steepest slopes.

  15. Lava Flows in the Grand Canyon

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Over vast expanses of time, natural processes like floods and volcanoes deposit layers of rock on the Earth's surface. To delve down through layers of rock is to explore our planet's history. Sometimes rock layers are exposed through human activity, such as drilling or excavation. Other times, rivers carve through the rock. One of the best, and most well-known, examples of a river exposing ancient rocks is Colorado River in Arizona's Grand Canyon. What fewer people know is that the Grand Canyon also has a history of relatively recent (on geologic time scales) volcanism. The evidence--hardened lava--spills down the canyon walls all the way to the river. On June 22, 2003, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the Grand Canyon, near 36.2 degrees north latitude and 113.2 degrees west longitude. ASTER detects light visible to human eyes as well as 'invisible' infrared light. Because different minerals reflect different portions of the light spectrum, ASTER can see varying mineral compositions of the rocks it observes, as well as detecting vegetation. In this three-dimensional visualization, lava fields appear brownish gray, darker than the layers of limestone, sandstone and other rock in the canyon. Vegetation appears green, and sparsely vegetated areas appear mustard. Water in the Colorado River is blue-purple. Geologists estimate that between 1.8 million and 400,000 years ago, lava flows actually dammed the Colorado River more than a dozen times. Some of the lava dams were as high as 600 meters (about 1,969 feet), forming immense reservoirs. Over time, enough water and sediment built up to push the river flow over the tops of these dams and eventually erode them away. Today, remnants of these lava dams remain throughout the area, along with the much older rock layers they cover. Among the most well known examples of these 'frozen' lava cascades is Lava Falls, which spills down to the river next to a cinder cone known as Volcan's Throne. Numerous flows spread down into Whitmore Canyon, a Colorado River tributary, as well.

  16. History of the youngest members of the Valles Rhyolite, Valles caldera, New Mexico using ESR dating method

    SciTech Connect

    Ogoh, K; Toyoda, S; Ikeda, S; Ikeya, M; Goff, F

    1991-01-01

    The cooling history of the Valles caldera was studied by the electron spin resonance (ESR) dating method using Al and Ti centers in quartz grains which were separated from the youngest units of the Valles Rhyolite. The ESR apparent ages are much younger than fission track ages and {sup 39}Ar- {sup 40}Ar ages. Three possibilities are suggested, the first is that the ESR ages are real, the second is that ESR method did not work for these samples, and the third is that about 10--40 ka, the signal intensity was partially reduced by a thermal event such as proposed by Harrison et al. (1986). Research on the first and second possibilities is continuing. The third possibility might explain the difference between ESR ages and those by other methods (fission track and {sup 39}Ar- {sup 40}Ar). ESR dating has produced new insights regarding the history of the Valles caldera.

  17. Canyon-confined pockmarks on the western Niger Delta slope

    NASA Astrophysics Data System (ADS)

    Benjamin, Uzochukwu; Huuse, Mads; Hodgetts, David

    2015-07-01

    Fluid flow phenomena in the deepwater Niger Delta are important for the safe and efficient exploration, development and production of hydrocarbons in the area. Utilizing 3D seismic data from the western Niger Delta slope, we have identified pockmarks that are confined within a NE-SW oriented submarine canyon system that has been active since the early Quaternary. The pockmarks, subdivided into 'canyon-margin' pockmarks and 'intra-canyon' pockmarks, on the basis of their plan-form distribution patterns, are found to be spatially and stratigraphically related to stratigraphic discontinuities created by erosion cuts associated with the submarine canyon system. We infer that stratigraphic discontinuities provided pathways for fluid migration within the buried canyon system, allowing fluids from deeper parts of the basin to reach the seafloor as indicated by abundant pockmarks above the partly buried canyon. The transportation of fluids from deeper parts of the basin into the buried segment of the canyon system was facilitated by carrier beds expressed as high amplitude reflection packages and by extensional normal faults. The prevalence of the 'canyon margin' pockmarks over the 'intra-canyon' pockmarks is attributed to the direct connection of the buried canyon margins with truncated reservoir facies in hydraulic connection with deeper reservoir facies. The formation of the 'intra-canyon' pockmarks is interpreted to have been limited by fluid flow disconnection often caused by stratigraphic alternation of sand-rich and shale-rich channel deposits that constitute the canyon fill. Muddy canyon fill units act as baffles to fluid flow, while connected sandy infill units constitute pathways for fluid migration. Occurrence of pockmarks throughout the length of the submarine canyon system is an indication of shallow fluid flow within buried reservoir facies. Systematic alignment of seafloor pockmarks are clues to buried reservoirs and provide insights into reservoir architecture which could be crucial in frontier exploration of buried deepwater canyons reservoirs and for risk assessment of development activities on top of submarine canyons. A single mega pockmark linked by a gas chimney to a deeper anticlinal structure was discovered to the north of the canyon system. This structure may be indicative of subsurface geo-pressures close to the fracture gradient, highlighting a significant drilling hazard in this part of the study area.

  18. NO2 photolysis frequencies in street canyons

    NASA Astrophysics Data System (ADS)

    Koepke, P.; Garhammer, M.; Hess, M.; Roeth, E.-P.

    2010-05-01

    Photolysis frequencies for NO2 are modeled for the conditions in urban streets, which are taken into account as canyons with variable height and width. The effect of a street canyon is presented with absolute values and as a ratio RJ of the photolysis frequency within the street against those with free horizon, which allows further use of the existing photolysis parameterizations. Values are presented for variable solar elevation and azimuth angles, varying atmospheric conditions and different street properties. The NO2 photolysis frequency in the street, averaged over atmospheric conditions and street orientation, is reduced to less than 20% for narrow streets, to about 40% for typical urban streets, and only to about 80% for garden streets, each with about ±5% uncertainty. A parameterization of RJ with the global solar irradiance is given for values that are averaged over the meteorological conditions and the street orientation.

  19. NO2 photolysis frequencies in street canyons

    NASA Astrophysics Data System (ADS)

    Koepke, P.; Garhammer, M.; Hess, M.; Roeth, E.-P.

    2010-08-01

    Photolysis frequencies for NO2 are modeled for the conditions in urban streets, which are taken into account as canyons with variable height and width. The effect of a street canyon is presented with absolute values and as a ratio RJ of the photolysis frequency within the street compared to that with free horizon. This allows further use of the existing photolysis parameterizations. Values are presented for variable solar elevation and azimuth angles, varying atmospheric conditions and different street properties. The NO2 photolysis frequency in a street depends strongly on the relative width of the street and its orientation towards the sun. Averaged over atmospheric conditions and street orientation, the NO2 photolysis frequency is reduced in comparison with the values for free horizon: to less than 20% for narrow skyscraper streets, to about 40% for typical urban streets, and only to about 80% for garden streets. A parameterization with the global solar irradiance is given for the averaged RJ values.

  20. DOI Strategic Sciences Working Group Mississippi Canyon 252/Deepwater Horizon Oil Spill

    E-print Network

    DOI Strategic Sciences Working Group Mississippi Canyon 252/Deepwater Horizon Oil Spill Strategic Sciences Working Group Mississippi Canyon 252/Deepwater Horizon Oil Spill Progress Report Executive Summary Introduction and Objectives The Mississippi Canyon 252/Deepwater Horizon (MS252) oil spill

  1. 78 FR 42799 - Glen Canyon Dam Adaptive Management Work Group Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ...4073000] Glen Canyon Dam Adaptive Management Work Group Meetings AGENCY: Bureau of Reclamation...The Glen Canyon Dam Adaptive Management Work Group (AMWG) makes recommendations to...advisory committee, the AMWG, a technical work group (TWG), a Grand Canyon...

  2. 4. View to northwest from within Castro Creek Canyon, looking ...

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

    4. View to northwest from within Castro Creek Canyon, looking up at 'Antique' Building (HABS-CA-2611-C) at left and center, 'Champagne' Building (HABS-CA-2611-D) at right behind redwood trees. View gives indication of steepness of canyon, siting of these two buildings at canyon's edge. - Deetjen's Big Sur Inn, East Side of State Highway 1, Big Sur, Monterey County, CA

  3. The marine soundscape of the Perth Canyon

    NASA Astrophysics Data System (ADS)

    Erbe, Christine; Verma, Arti; McCauley, Robert; Gavrilov, Alexander; Parnum, Iain

    2015-09-01

    The Perth Canyon is a submarine canyon off Rottnest Island in Western Australia. It is rich in biodiversity in general, and important as a feeding and resting ground for great whales on migration. Australia's Integrated Marine Observing System (IMOS) has moorings in the Perth Canyon monitoring its acoustical, physical and biological oceanography. Data from these moorings, as well as weather data from a near-by Bureau of Meteorology weather station on Rottnest Island and ship traffic data from the Australian Maritime Safety Authority were correlated to characterise and quantify the marine soundscape between 5 and 3000 Hz, consisting of its geophony, biophony and anthrophony. Overall, biological sources are a strong contributor to the soundscape at the IMOS site, with whales dominating seasonally at low (15-100 Hz) and mid frequencies (200-400 Hz), and fish or invertebrate choruses dominating at high frequencies (1800-2500 Hz) at night time throughout the year. Ships contribute significantly to the 8-100 Hz band at all times of the day, all year round, albeit for a few hours at a time only. Wind-dependent noise is significant at 200-3000 Hz; winter rains are audible underwater at 2000-3000 Hz. We discuss how passive acoustic data can be used as a proxy for ocean weather. Passive acoustics is an efficient way of monitoring animal visitation times and relative densities, and potential anthropogenic influences.

  4. Greening of the Grand Canyon -- developing a sustainable design for the Grand Canyon National Park

    SciTech Connect

    Gordon, H.T.

    1995-11-01

    The Grand Canyon National Park (GCNP) is faced with increasing visitor demand that is threatening the natural and cultural resources of one of the most popular recreation sites in the United States. The National Park Service (NPS) developed a draft General Management Plan (GMP), which provides management objectives and visions for the entire park, with alternative plans for the park`s developed areas. With the GMP as a starting point, a Grand Canyon Sustainable Design Workshop was conducted to make the Grand Canyon National Park more environmentally and economically sustainable. The workshop, which used the Environmental Design Charrette process, addressed integrated environmental solutions and their implementation in three primary areas: Integrated Information, Visitor Experience, and Resource Efficiency. This paper describes the Environmental Design Charrette process and the efforts of the Resource Efficiency group.

  5. Transfer processes in a simulated urban street canyon

    NASA Astrophysics Data System (ADS)

    Solazzo, E.; Britter, R. E.

    2007-07-01

    The transfer processes within and above a simulated urban street canyon were investigated in a generic manner. Computational fluid dynamics (CFD) was used to aid understanding and to produce some simple operational parameterisations. In this study we addressed specifically the commonly met situation where buoyancy effects arising from elevated surface temperatures are not important, i.e. when mechanical forces outweigh buoyancy forces. In a geophysical context this requires that some suitably defined Richardson number is small. From an engineering perspective this is interpreted as the important case when heat transfer within and above urban street canyons is by forced convection. Surprisingly, this particular scenario (for which the heat transfer coefficient between buildings and the flow is largest), has been less well studied than the situation where buoyancy effects are important. The CFD technique was compared against wind-tunnel experiments to provide model evaluation. The height-to-width ratio of the canyon was varied through the range 0.5 5 and the flow was normal to the canyon axis. By setting the canyon’s facets to have the same or different temperatures or to have a partial temperature distribution, simulations were carried out to investigate: (a) the influence of geometry on the flow and mixing within the canyon and (b) the exchange processes within the canyon and across the canyon top interface. Results showed that the vortex-type circulation and turbulence developed within the canyon produced a temperature distribution that was, essentially, spatially uniform (apart from a relatively thin near-wall thermal boundary layer) This allowed the temperatures within the street canyon to be specified by just one value T can , the canyon temperature. The variation of T can with wind speed, surface temperatures and geometry was extensively studied. Finally, the exchange velocity u E across the interface between the canyon and the flow above was calculated based on a heat flux balance within the canyon and between the canyon and the flow above. Results showed that u E was approximately 1% of a characteristic wind velocity above the street canyon. The problem of radiative exchange is not addressed but it can, of course, be introduced analytically, or computationally, when necessary.

  6. Ascension Submarine Canyon, California - Evolution of a multi-head canyon system along a strike-slip continental margin

    USGS Publications Warehouse

    Nagel, D.K.; Mullins, H.T.; Greene, H. Gary

    1986-01-01

    Ascension Submarine Canyon, which lies along the strike-slip (transform) dominated continental margin of central California, consists of two discrete northwestern heads and six less well defined southeastern heads. These eight heads coalesce to form a single submarine canyon near the 2700 m isobath. Detailed seismic stratigraphic data correlated with 19 rock dredge hauls from the walls of the canyon system, suggest that at least one of the two northwestern heads was initially eroded during a Pliocene lowstand of sea level ???3.8 m.y. B.P. Paleogeographic reconstructions indicate that at this time, northwestern Ascension Canyon formed the distal channel of nearby Monterey Canyon and has subsequently been offset by right-lateral, strike-slip faulting along the San Gregorio fault zone. Some of the six southwestern heads of Ascension Canyon may also have been initially eroded as the distal portions of Monterey Canyon during late Pliocene-early Pleistocene sea-level lowstands (???2.8 and 1.75 m.y. B.P.) and subsequently truncated and offset to the northwest. There have also been a minimum of two canyon-cutting episodes within the past 750,000 years, after the entire Ascension Canyon system migrated to the northwest past Monterey Canyon. We attribute these late Pleistocene erosional events to relative lowstands of sea level 750,000 and 18,000 yrs B.P. The late Pleistocene and Holocene evolution of the six southeastern heads also appears to have been controlled by structural uplift of the Ascension-Monterey basement high at the southeastern terminus of the Outer Santa Cruz Basin. We believe that uplift of this basement high sufficiently oversteepened submarine slopes to induce gravitational instability and generate mass movements that resulted in the erosion of the canyon heads. Most significantly, though, our results and interpretations support previous proposals that submarine canyons along strike-slip continental margins can originate by tectonic trunction and lateral offset. ?? 1986.

  7. A natural analogue for high-level waste in tuff: Chemical analysis and modeling of the Valles site

    SciTech Connect

    Stockman, H.W.; Krumhansl, J.L.; Ho, C.K.; Kovach, L.; McConnell, V.S.

    1995-03-01

    The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a high-level waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock Tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, x-ray diffraction, and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and {sup 39}Ar/{sup 40}Ar isotopic composition. Overall, the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 m of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks.

  8. Chronology and evolution of a fluvial/canyon connection around the Last Glacial Maximum: The Bourcart canyon head (western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Mauffrey, Marie-Aline; Berné, Serge; Gaudin, Matthieu; Jouet, Gwenael

    2013-04-01

    Deeply incised canyons have been described in the Gulf of Lions since the end of the 19th century. Recently, the role of axial incision, as a pathway of high-density flows initiated within streams and cutting across the main thalweg of canyons, has been proposed as a mechanism for canyon evolution, in this area and elsewhere (Baztan et al., 2005). In this study, we used a large data base of very-high resolution seismic profiles in order to determine the precise architecture of the Bourcart (Aude) canyon head. The accurate 3D geometry of the buried and recent incisions through the Bourcart canyon head allows us to draw the pattern of canyon connections with shelf incised valleys. Furthermore, time constraints (and relation with sea-level changes) were obtained through the correlation with the Promess 1 drill site situated in the vicinity of the Bourcart canyon, and with long piston cores retrieved on the continental shelf in the same area. Our results demonstrate the direct connection of fluvial system(s) to present (and buried) axial incisions, and show the progressive evolution of seismic facies from typical "valley-fill" to typical "confined channel-levee" systems. Streams from the East (possibly the Rhone), then from the West (possibly the Agly) of the Gulf of Lions successively fed the canyon head. An important phase of deposition occurred within the canyon head at the onset of sea-level rise, probably in relation with increased water and sediment flux from the Pyrenees during the early Deglacial period. We hypothesize that, during this period, Pyrenean streams seasonally experienced very high-concentration sediment loads, capable of generating high density (probably hyperpycnal) flows in the canyon head. Only such high-concentration flows may explain the meandering pattern of axial incisions observed at very shallow depths, within the canyon head. Reference: Baztan, J. et al., 2005, Marine and Petroleum Geology, 22, 805-826

  9. Bridge 223, view looking east up Rock Creek Canyon at ...

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

    Bridge 22-3, view looking east up Rock Creek Canyon at Milepost 22.82. The line passes through tunnel 4 onto Bridge 22-3 and heads eastward up Rock Creek Canyon out onto the Camas Prairie - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

  10. 10. VIEW OF BRUSH ALONG KINGS CANYON ROAD WHICH WILL ...

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

    10. VIEW OF BRUSH ALONG KINGS CANYON ROAD WHICH WILL BE REMOVED FOR 10 FEET ON THE RIGHT SIDE OF THE ROADWAY FOR A DISTANCE OF 50 FEET. LOCATED AT MILEPOST 1.45, FACING NORTH 100 EAST (10ø). - Kings Canyon Road, Carson City, Carson City, NV

  11. 75 FR 34476 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation... Interior (Secretary) is renewing the charter for the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group is to advise and to provide recommendations to the...

  12. 78 FR 7810 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group.... L. 102-575) of 1992. The AMP includes a Federal advisory committee, the AMWG, a technical work...

  13. 76 FR 24516 - Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group...-575) of 1992. The AMP includes a Federal advisory committee, the AMWG, a technical work group (TWG),...

  14. Supplement to The Snake Hells Canyon Subbasin Plan Introduction

    E-print Network

    draft Snake Hells Canyon Subbasin Assessment and Snake Hells Canyon Subbasin Management Plan prepared Management Plan. Section IV describes the prioritization of strategies. I. Key factors limiting of these limiting factors are influenced primarily by events outside of the subbasin (out of subbasin impacts

  15. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Glen Canyon National Recreation Area. 7.70 Section 7.70 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT...

  16. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Glen Canyon National Recreation Area. 7.70 Section 7.70 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT...

  17. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Glen Canyon National Recreation Area. 7.70 Section 7.70 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT...

  18. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Glen Canyon National Recreation Area. 7.70 Section 7.70 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT...

  19. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Glen Canyon National Recreation Area. 7.70 Section 7.70 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT...

  20. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Grand Canyon National Park. 7.4 Section 7.4 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.4 Grand Canyon National Park. (a) Commercial passenger-carrying motor vehicles....

  1. Perspective view over the Grand Canyon, Arizona

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This simulated true color perspective view over the Grand Canyon was created from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data acquired on May 12, 2000. The Grand Canyon Village is in the lower foreground; the Bright Angel Trail crosses the Tonto Platform, before dropping down to the Colorado Village and then to the Phantom Ranch (green area across the river). Bright Angel Canyon and the North Rim dominate the view. At the top center of the image the dark blue area with light blue haze is an active forest fire.

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

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

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 5 km in foreground to 40 km Location: 36.3 degrees north latitude, 112 degrees west longitude Orientation: North-northeast at top Original Data Resolution: ASTER 15 meters Dates Acquired: May 12, 2000

  2. Pleistocene entrenched valley/canyon systems, Gulf of Mexico

    SciTech Connect

    Steffens, G.S.

    1986-09-01

    The Mississippi Submarine Canyon is the seaward extension of the late Wisconsin entrenched alluvial valley. Geophysical and geologic data provide evidence for the continuity of the Mississippi entrenched valley, the Timbalier channel, and the submarine canyon. The Mississippi entrenched valley/canyon system is one of several systems recognized in the Pleistocene section of offshore Louisiana. Most of these systems were produced by the ancestral Mississippi River. They typically exhibit a three-gradient profile with their maximum erosional relief at the preexisting shelf margin. The canyons extend onto the pre-existing shelf for 20 to 50 mi, with erosion commonly exceeding 1000 ft. All of these systems delivered large quantities of sediment to the Pleistocene slope and abyssal plain. The fan deposits are the products of sediment passing through and being removed from the entrenched valley/canyon systems.

  3. North Atlantic slope and canyon study. Volume 2. Final report

    SciTech Connect

    Butman, B.

    1986-12-01

    A field program to investigate the currents and sediment transport along the outershelf and upper slope along the southern flank of Georges Bank was conducted between 1980 and 1984. A major part of the field experiment was conducted in Lydonia Canyon, a large submarine canyon which cuts northward about 20 km into the continental shelf from the shelfbreak. A smaller experiment was conducted in Oceanographer Canyon to compare the currents in these two major canyons. Long-term current observations were made at 20 locations in or adjacent to Lydonia Canyon, and at 9 stations on the continental slope. Detailed semi-synoptic hydrographic observations were made on 9 cruises. The currents associated with Gulf Stream warm core rings (WCR's) strongly affect the flow along the outer shelf and upper slope; eastward currents in excess of 75cm/s were associated with WCR's.

  4. Evolution of surface gravity waves over a submarine canyon

    E-print Network

    Magne, R; Herbers, T H C; Ardhuin, F; O'Reilly, W C; Rey, V; Magne, Rudy; Belibassakis, Kostas; Herbers, Thomas H. C.; Ardhuin, Fabrice; Reilly, William C. O'; Rey, Vincent

    2006-01-01

    The effects of a submarine canyon on the propagation of ocean surface waves are examined with a three-dimensional coupled-mode model for wave propagation over steep topography. Whereas the classical geometrical optics approximation predicts an abrupt transition from complete transmission at small incidence angles to no transmission at large angles, the full model predicts a more gradual transition with partial reflection/transmission that is sensitive to the canyon geometry and controlled by evanescent modes for small incidence angles and relatively short waves. Model results for large incidence angles are compared with data from directional wave buoys deployed around the rim and over Scripps Canyon, near San Diego, California, during the Nearshore Canyon Experiment (NCEX). Wave heights are observed to decay across the canyon by about a factor 5 over a distance shorter than a wavelength. Yet, a spectral refraction model predicts an even larger reduction by about a factor 10, because low frequency components c...

  5. Green Machine Florida Canyon Hourly Data

    SciTech Connect

    Vanderhoff, Alex

    2013-07-15

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 6/1/13 to 6/30/13

  6. 20140430_Green Machine Florida Canyon Hourly Data

    DOE Data Explorer

    Thibedeau, Joe

    2014-05-05

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 01 April to 30 April 2014.

  7. 20130416_Green Machine Florida Canyon Hourly Data

    DOE Data Explorer

    Vanderhoff, Alex

    2013-04-24

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 4/16/13.

  8. Green Machine Florida Canyon Hourly Data 20130731

    DOE Data Explorer

    Vanderhoff, Alex

    2013-08-30

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 7/1/13 to 7/31/13.

  9. River resource management in the Grand Canyon

    SciTech Connect

    1996-07-01

    The objective of GCES was to identify and predict the effects of variations in operating strategies on the riverine environment below Glen Canyon Dam within the physical and legal constraints under which the dam must operate. Critical elements for the development of GCES and other such projects include a list of resources directly or indirectly affected by management, a list of management options, and an ecosystem framework showing the causal connections among system components, potential management strategies that include humans as integral parts of the environment.

  10. Hanging canyons of Haida Gwaii, British Columbia, Canada: Fault-control on submarine canyon geomorphology along active continental margins

    NASA Astrophysics Data System (ADS)

    Harris, Peter T.; Barrie, J. Vaughn; Conway, Kim W.; Greene, H. Gary

    2014-06-01

    Faulting commonly influences the geomorphology of submarine canyons that occur on active continental margins. Here, we examine the geomorphology of canyons located on the continental margin off Haida Gwaii, British Columbia, that are truncated on the mid-slope (1200-1400 m water depth) by the Queen Charlotte Fault Zone (QCFZ). The QCFZ is an oblique strike-slip fault zone that has rates of lateral motion of around 50-60 mm/yr and a small convergent component equal to about 3 mm/yr. Slow subduction along the Cascadia Subduction Zone has accreted a prism of marine sediment against the lower slope (1500-3500 m water depth), forming the Queen Charlotte Terrace, which blocks the mouths of submarine canyons formed on the upper slope (200-1400 m water depth). Consequently, canyons along this margin are short (4-8 km in length), closely spaced (around 800 m), and terminate uniformly along the 1400 m isobath, coinciding with the primary fault trend of the QCFZ. Vertical displacement along the fault has resulted in hanging canyons occurring locally. The Haida Gwaii canyons are compared and contrasted with the Sur Canyon system, located to the south of Monterey Bay, California, on a transform margin, which is not blocked by any accretionary prism, and where canyons thus extend to 4000 m depth, across the full breadth of the slope.

  11. Land- and resource-use issues at the Valles Caldera

    SciTech Connect

    Intemann, P.R.

    1981-01-01

    The Valles Caldera possesses a wealth of resources from which various private parties as well as the public at large can benefit. Among the most significant of these are the geothermal energy resource and the natural resource. Wildlife, scenic, and recreational resources can be considered components of the natural resource. In addition, Native Americans in the area value the Valles Caldera as part of their religion. The use of land in the caldera to achieve the full benefits of one resource may adversely affect the value of other resources. Measures can be taken to minimize adverse affects and to maximize the benefits of all the varied resources within the caldera as equitably as possible. An understanding of present and potential land and resource uses in the Caldera, and who will benefit from these uses, can lead to the formulation of such measures.

  12. Core log: Valles caldera No. 2A, New Mexico

    SciTech Connect

    Starguist, V.L.

    1988-01-01

    Scientific core hole VC-2A was drilled into the western ring-fracture zone at Sulphur Springs in the Valles caldera, New Mexico. VC-2A, the second scientific core hole in the caldera, was cored through a faulted and brecciated sequence of intracauldron tuffs and volcaniclastic rocks to a depth of 528 m. As of November 1, 1986, the unequilibrated bottom-hole temperature was 212/degree/C. The rocks penetrated are intensely altered and host sub-ore grade stockwork molybdenite mineralization between 25 and 125 m. This report contains a detailed core log to aid researchers in their studies of the Valles caldera magma hydrothermal system. 3 refs., 2 figs.

  13. 75 FR 44809 - Glen Canyon Dam Adaptive Management Work Group (AMWG)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ...Interior concerning Glen Canyon Dam operations and other management...resources downstream of Glen Canyon Dam consistent with the Grand Canyon...Protocol and the Non-Native Fish Control/Removal environmental...administrative history of the Glen Canyon Dam Adaptive Management...

  14. 28. Fern Canyon (Meier 1979) This established RNA is on the San Dimas

    E-print Network

    28. Fern Canyon (Meier 1979) Location This established RNA is on the San Dimas Experimental Forest of bigcone Douglas-fir (BDF) at Fern Canyon have burned recently (1975). Poor reproduction suggestsUSDA Forest Service General Technical Report PSW-GTR-188. 2004. 28. Fern Canyon Figure 58--Fern Canyon

  15. Canyons and Mesas of Aureum Chaos

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 17 June 2002) This image contains a portion of Aureum Chaos located just south of the Martian equator. This fractured landscape contains canyons and mesas with two large impact craters in the upper left. The largest crater is older than the one above it. This is readily evident because a landslide deposit created by the smaller crater's impact is seen on the larger crater's floor. The overall scene has a rather muted appearance due to mantling by dust. Some small dark streaks can also be seen in this scene. These small dark streaks suggest that the materials covering this area occasionally become unstable and slide. Ridges of resistant material also can be observed in the walls of the canyons. The wall rock seen in the upper part of the cliffs appears to be layered. Classic spur and gully topography created by differing amounts of erosion and possibly different rock types is also visible here. One important observation to be made in this region is that there are no gullies apparent on the slopes such as those seen in Gorgonum Chaos (June 11th daily image). Latitude appears to play a major role in gully occurrence and distribution, with the gullies being predominately found pole ward of 30o.

  16. Bird's-Eye View Steven M. LaValle

    E-print Network

    LaValle, Steven M.

    Available for downloading at http://msl.cs.uiuc.edu/vr/ #12;Chapter 2 Bird's-Eye View Chapter Status Taken from Virtual Reality, S. M. LaValle This online chapter is not the final version! Check http://msl.cs.uiuc.edu/vr a overview of VR systems from hardware (Section ?? to software 2.2 to human perception 2.3. The purpose

  17. Episodes of fluvial and volcanic activity in Mangala Valles, Mars

    NASA Astrophysics Data System (ADS)

    Keske, Amber L.; Hamilton, Christopher W.; McEwen, Alfred S.; Daubar, Ingrid J.

    2015-01-01

    A new mapping-based study of the 900-km-long Mangala Valles outflow system was motivated by the availability of new high-resolution images and continued debates about the roles of water and lava in outflow channels on Mars. This study uses photogeologic analysis, geomorphic surface mapping, cratering statistics, and relative stratigraphy. Results show that Mangala Valles underwent at least two episodes of fluvial activity and at least three episodes of volcanic activity during the Late Amazonian. The occurrence of scoured bedrock at the base of the mapped stratigraphy, in addition to evidence provided by crater retention ages, suggests that fluvial activity preceded the deposition of two of the volcanic units. Crater counts performed at 30 locations throughout the area have allowed us to construct the following timeline: (1) formation of Noachian Highlands and possible initial flooding event(s) before ?1 Ga, (2) emplacement of Tharsis lava flows in the valley from ?700 to 1000 Ma, (3) a megaflooding event at ?700-800 Ma sourced from Mangala Fossa, (4) valley fill by a sequence of lava flows sourced from Mangala Fossa ?400-500 Ma, (5) another megaflooding event from ?400 Ma, (6) a final phase of volcanism sourced from Mangala Fossa ?300-350 Ma, and (7) emplacement of eolian sedimentary deposits in the northern portion of the valley ?300 Ma. These results are consistent with alternating episodes of aqueous flooding and volcanism in the valles. This pattern of geologic activity is similar to that of other outflow systems, such as Kasei Valles, suggesting that there is a recurring, and perhaps coupled, nature of these processes on Mars.

  18. Grjotá Valles and implications for flood sediment deposition on Mars

    NASA Astrophysics Data System (ADS)

    Burr, Devon M.; Parker, Alex H.

    2006-11-01

    Grjotá Valles is one of Mars' four Amazonian-aged, fissure-headed, catastrophic flood channels. It originates at the northwestern-most Cerberus Fossa and stretches several hundred kilometers eastward and southward. Moats around in-channel knobs and various small-scale mounds, similar to mounds seen in Athabasca Valles, are both attributed to flood-related processes. The floodwater sinks are ambiguous, and the lack of recognizable flood deposits is attributed to two causes. The first cause is the channel's high width-to-depth ratio, which may have facilitated floodwater recession during flooding. The second cause is the tendency of floodwater under lower gravity to move a higher percentage of material as washload. As flood deposits are comprised of bedload and suspended load, this tendency would result in fewer depositional bedforms. Our analysis of Grjotá Valles supports the idea that formation of terrestrial-style flood deposits is energetically unlikely on Mars and that their presence indicates special paleohydraulic conditions.

  19. Continental Scientific Drilling Program: Valles Caldera, New Mexico

    SciTech Connect

    1993-01-01

    The U.S. Continental Scientific Drilling Program attempts to develop a better understanding of the geologic and hydrologic mechanisms within the continental crust, under the auspices of an interagency group comprising the US Department of Energy, the National Science Foundation, and the U.S. Geological Survey. Ten years of research and drilling in the Valles caldera of northern New Mexico has provided a new understanding of volcanism and geothermal systems within a large caldera. Situated at the intersection of the Rio Grande rift and the Jemez volcanic lineament, the Valles caldera and Toledo calderas were formed during two massive eruptions 1.1 and 1.5 M a that vented approximately 300 to 400 km{sup 3} of high-silica rhyolitic tephra. The research at the Valles/Toledo caldera has provided more than 3000 m of corehole samples, which are stored in a repository in Grand Junction, Colorado, and are accessible to the public. This research has also helped support theories of mineral deposition within hydrothermal systems-hot water circulating through breccias, leaching elements from the rocks, and later depositing veins of economically valuable materials.

  20. Geologic controls on the morphology of La Aguja submarine canyon

    NASA Astrophysics Data System (ADS)

    Restrepo-Correa, Isabel C.; Ojeda, Germán Y.

    2010-10-01

    The seascape of the continental shelf and slope offshore Santa Marta is sculpted by the submarine Aguja Canyon, a deep seafloor incision that extends from the inner shelf to the continental rise along some 115 km. No major modern rivers flow into this canyon, thus ruling out principal fluvial control on the present geometry of this feature. Recently acquired multibeam sonar bathymetry data have provided insight into the three-dimensional geometry of this outstanding feature that disrupts the seafloor relief. In addition, seismic reflection data provide images of the internal structure of the canyon's subsurface. In this study, we describe the morphology of the Aguja Canyon along a series of transects, interpret the structure under the canyon, and discuss possible geologic processes that played a role during its formation and modification. Seismic data indicate that incision of the canyon's inner reach is the result of recent motion along the western termination of the active Oca strike-slip fault. Relief in the middle reach may be predominantly controlled by sedimentary processes (erosion, infilling and lateral thalweg migration). In the past, however, the middle reach may have been tectonically controlled. The outer reach appears to be the combined result of tectonics, sedimentary process and mud-diapiric intrusions. We conclude that the Aguja Canyon is predominantly a tectonic feature that accommodates shallow transpressive stresses as dislocation of the seafloor.

  1. Physical modeling of tidal resonance in a submarine canyon

    NASA Astrophysics Data System (ADS)

    Souëf, K. E.; Allen, S. E.

    2014-02-01

    Current observations in submarine canyons poleward of 30° are usually dominated by the semidiurnal (M2) tidal frequency, which is superinertial at these latitudes. Observations from a submarine canyon at 44°N (the Gully, Nova Scotia) suggest that canyons can be dominated by the subinertial (K1) tidal frequency if length scales are correct for resonance of the K1 frequency. A model of the Gully was constructed in a tank on a rotating table and tidal currents generated to determine factors that influence resonance. Resonance curves were fit to measurements from the laboratory canyon for a range of stratifications, background rotation rates, and forcing amplitudes. Dense water was observed upwelling onto the continental shelf on either side of the laboratory canyon and traveled at least one canyon width along the shelf. Friction values measured in the laboratory were much higher than expected, probably due to upwelled water surging onto the shelf on each tidal cycle, similar to a tidal bore. By scaling observations from the laboratory to the ocean and assuming friction in the ocean is also affected by water traveling onto the shelf, a resonance curve for the ocean was created. Because of the broad resonance curve, the diurnal tide remains strong year round at the Gully, even as stratification at the shelf break changes. Dense water surging onto the shelf on tidal frequencies may affect friction and mixing at other nonresonant canyons.

  2. Inner gorge-slot canyon system produced by repeated stream incision (eastern Alps): Significance for development of bedrock canyons

    NASA Astrophysics Data System (ADS)

    Sanders, Diethard; Wischounig, Lukas; Gruber, Alfred; Ostermann, Marc

    2014-06-01

    Many inner bedrock gorges of the Alps show abrupt downstream changes in gorge width, as well as channel type and gradient, as a result of epigenetic incision of slot canyons. Many slot canyons also are associated with older gorge reaches filled with Quaternary deposits. The age of slot canyons and inner bedrock gorges, however, commonly is difficult to constrain. For the inner-bedrock gorge system of the Steinberger Ache catchment (eastern Alps), active slot canyons as well as older, abandoned gorge reaches filled with upper Würmian proglacial deposits record three phases of gorge development and slot-canyon incision. A 234U/230Th age of cement of 29.7 ± 1.8 ka in fluvial conglomerates onlapping the flank of an inner gorge fits with late Würmian valley-bottom aggradation shortly before pleniglacial conditions; in addition, the age indicates that at least the corresponding canyon reach must be older. During advance of ice streams in the buildup of the Last Glacial Maximum (LGM), the catchment was blocked, and a proglacial lake formed. Bedrock gorges submerged in that lake were filled with fluviolacustrine deposits. During the LGM, the entire catchment was overridden by ice. During post-glacial reincision, streams largely found again their preexisting inner bedrock canyons. In some areas, however, the former stream course was 'missed', and a slot canyon formed. The distribution of Pleistocene deposits, the patterns of canyon incision, and the mentioned U/Th cementation age, however, together record a further discrete phase of base-level rise and stream incision well before the LGM. The present course of Steinberger Ache and its tributaries is a patchwork of (1) slot canyons incised during post-glacial incision; (2) vestiges of slot canyons cut upon an earlier (middle to late Würmian?) cycle of base-level rise and fall; (3) reactivated reaches up to ~ 200 m in width of inner bedrock gorge that are watershed at present, and more than at least ~ 30 ka in age; and (4) abandoned, sediment-filled reaches of bedrock canyons that also must be older than 30 ka and that are exposed alongside the active streams. 'Multi-cyclic' bedrock canyon systems composed of reaches of markedly different ages may be common in mountain ranges subject to glaciations and/or mass wasting.

  3. Physiographic rim of the Grand Canyon, Arizona: a digital database

    USGS Publications Warehouse

    Billingsley, George H.; Hampton, Haydee M.

    1999-01-01

    This Open-File report is a digital physiographic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report. The report does include, however, PostScript and PDF format plot files, each containing an image of the map. For those interested in a paper plot of information contained in the database or in obtaining the PostScript plot files, please see the section entitled "For Those Who Don't Use Digital Geologic Map Databases" below. This physiographic map of the Grand Canyon is modified from previous versions by Billingsley and Hendricks (1989), and Billingsley and others (1997). The boundary is drawn approximately along the topographic rim of the Grand Canyon and its tributary canyons between Lees Ferry and Lake Mead (shown in red). Several isolated small mesas, buttes, and plateaus are within this area, which overall encompasses about 2,600 square miles. The Grand Canyon lies within the southwestern part of the Colorado Plateaus of northern Arizona between Lees Ferry, Colorado River Mile 0, and Lake Mead, Colorado River Mile 277. The Colorado River is the corridor for raft trips through the Grand Canyon. Limestone rocks of the Kaibab Formation form most of the north and south rims of the Grand Canyon, and a few volcanic rocks form the north rim of parts of the Uinkaret and Shivwits Plateaus. Limestones of the Redwall Limestone and lower Supai Group form the rim of the Hualapai Plateau area, and Limestones of Devonian and Cambrian age form the boundary rim near the mouth of Grand Canyon at the Lake Mead. The natural physiographic boundary of the Grand Canyon is roughly the area a visitor would first view any part of the Grand Canyon and its tributaries.

  4. Distribution and Transport of Pyrogenic Black Carbon in Soils Affected by Wildfires, Valles Caldera, New Mexico, with Implications

    E-print Network

    Johnson, Eric E.

    , Valles Caldera, New Mexico, with Implications for Contaminant Transport WRRI Technical Completion Report DISTRIBUTION AND TRANSPORT OF PYROGENIC BLACK CARBON IN SOILS AFFECTED BY WILDFIRES, VALLES CALDERA, NEW MEXICO were sampled near Valles Caldera, NM: Thompson Ridge fire (TR; burned in 2013), Las Conchas fire

  5. S. LaValle ICRA VR Workshop 2015 1 / 22 Challenges in Virtual Reality

    E-print Network

    LaValle, Steven M.

    to maintain a baseline: Comfort, safety, belief (immersion, presence) #12;Some History S. LaValle ICRA VR became one of the most over-hyped technologies ever. Problem: The component technology was not ready yet your home were bigger? #12;Movies S. LaValle ICRA VR Workshop 2015 ­ 10 / 22 A private virtual movie

  6. Report Summary, Final Hells Canyon Environmental Investigation.

    SciTech Connect

    United States. Bonneville Power Administration.

    1985-01-01

    The Northwest Electric Power Planning and Conservation Act of 1980 provided for the establishment of a Regional Power Planning Council (Regional Council) and mandated the development of a Columbia River Basin Fish and Wildlife Program (F&W Program). The F&W Program was adopted by the Regional Council in November 1982. and is intended to mitigate fish and wildlife losses resulting from the development of hydroelectric dams on the Columbia and Snake Rivers. One element of the FLW Program is the Water Budget. It calls for additional flows in the Columbia and Snake Rivers between April 15 and June 15 to improve the survival of juvenile salmon and steelhead migrating downstream. The Snake River's contribution to the Water Budget is 20,000 cubic feet per second-months (A volume of water equal to a flow of 20.000 cubic feet per second, 24 hours per day, for a period of a month) over and above water that would normally flow for power production. The water for the Water Budget would come out of Idaho Power Company's (IPCo) Hells Canyon Complex and the Corps of Engineers' (Corps) Dvorshak Reservoir. IPCo's Hells Canyon Complex consists of three dams, Brownlee, Oxbow, and Hells Canyon. Brownlee, at the upstream end, contains a large reservoir and controls flow to the lower dams. IPCo's participation in the Water Budget could affect the level of the Brownlee Reservoir and flows downstream of the Hells Canyon Complex on the Snake River. In light of this, Bonneville Power Administration (BPA) and IPCo contracted with the consulting firm of CH2!4 Hill to study the potential changes that could occur to the environment. The Environmental Investigation (EI) takes into account concerns that were expressed by the public at a series of public meetings held in the Snake River area during June 1983 and again during September 1984. Existing information and consultations with agencies which have management responsibilities in the project area formed the basis for the data used in the EI. This document summarizes the findings of the final EI in the following areas: (1) natural features, water use, and air and water quality; (2) fish, wildlife, and vegetation; (3) land use, recreation, and aesthetics; and (4) historical and archaeological resources. The EI provides information to be used by IPCo as they assess the effect on the system operations (power and nonpower) resulting from Water Budget participation. BPA and IPCo are continuing to discuss the prospects for IPCo's involvement in implementation of the Water Budget on the Snake River. When IPCo reaches a decision on whether and to what extent it wishes to participate in a Water Budget agreement with BPA, the proposed agreement will be subject to analysis under the National Environmental Policy Act (NEPA). That analysis will consider alternatives, significance of impacts to the environment, and mitigative measures.

  7. Flow Focusing as a Control on the Width of Canyons Formed by Outburst Floods

    NASA Astrophysics Data System (ADS)

    Lapotre, M. G.; Lamb, M. P.; Halliday, C. K.

    2012-12-01

    Spectacular canyons exist on the surfaces of Earth and Mars that were carved by ancient outburst megafloods. These canyons often have steep headwalls and were eroded into jointed rock. This suggests that canyon formation is driven by upstream retreat of waterfalls through toppling failure. Discharge reconstructions remain difficult, however, because we do not understand quantitatively the links between canyon formation and canyon morphology. Here we propose that the width of canyon headwalls is set by the shear stress distribution around the rim of the canyon, which governs the propensity for toppling failure, and that this distribution is controlled by focusing of flood water into the canyon head. To test this hypothesis, we performed a series of numerical simulations of 2-D, depth-averaged, turbulent flow using the hydraulic numerical modeling suite ANUGA Hydro and mapped the shear stresses along the rim of canyons of various geometries. The numerical simulations were designed to explore three dimensionless variables: the aspect ratio of the canyon (length normalized by width), the canyon width relative to the normal flow depth, and the Froude number. Preliminary results show that flow focusing at the head of a canyon can lead to heightened shear stresses there compared to the sides of the canyon. Flow focusing is most efficient for subcritical flows with large canyon aspect ratios, suggesting that canyons grow in all directions until they reach a critical length which depends on the Froude number only. Canyons longer than this critical length maintain a uniform width during canyon formation. Earth-analog canyons, where flood depths were constrained from previous paleo-hydraulic studies, show good agreement with our numerical predictions, suggesting that flow focusing may set the width of canyons during megafloods. Model results allow a link between process and form that will enable us to constrain better flood discharges on Earth and Mars, where other robust paleo-hydraulic tools are not available.

  8. A view in Lapwai Canyon at Milepost 18 of the ...

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

    A view in Lapwai Canyon at Milepost 18 of the grade cut through basalt - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

  9. 3. VIEW OF DIABLO CANYON LOOKING DOWNSTREAM FROM THE VALVE ...

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

    3. VIEW OF DIABLO CANYON LOOKING DOWNSTREAM FROM THE VALVE HOUSE AT ELEVATION 1044, 1989. - Skagit Power Development, Diablo Dam, On Skagit River, 6.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  10. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...owned land administered by the National Park Service, along the Colorado River within Grand Canyon National Park, upstream from Diamond Creek at approximately river mile 226: (1) No person shall operate a vessel engaging in predominantly upstream...

  11. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...guide a river trip unless such person possesses a permit issued by the Superintendent, Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  12. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Recreation Area unless such person possesses a permit issued by the Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  13. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Recreation Area unless such person possesses a permit issued by the Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  14. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Recreation Area unless such person possesses a permit issued by the Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  15. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Recreation Area unless such person possesses a permit issued by the Superintendent of Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  16. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...guide a river trip unless such person possesses a permit issued by the Superintendent, Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  17. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...guide a river trip unless such person possesses a permit issued by the Superintendent, Grand Canyon National Park. The National Park Service reserves the right to limit the number of such permits issued, or the number of persons traveling on...

  18. 78 FR 60693 - Establishment of the Ballard Canyon Viticultural Area

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... Federal Register on January 16, 2013 (78 FR 3370), proposing to establish the Ballard Canyon viticultural... approximately 0.25 mile to the intersection of Chalk Hill Road and an unnamed, light- duty road known locally...

  19. Sandbar on the Colorado River in Grand Canyon

    USGS Multimedia Gallery

    Sandbar on the Colorado River in Grand Canyon deposited by the 2008 controlled flood. The view is looking downstream and the location is approximately 65 miles downstream from Lees Ferry, Arizona.  ...

  20. Sandbar on the Colorado River in Grand Canyon

    USGS Multimedia Gallery

    Sandbar on the Colorado River in Grand Canyon deposited by 2008 controlled flood. The river is flowing from left to right and the location is approximately 64 miles downstream from Lees Ferry, Arizona....

  1. VIEW TO THE SOUTH OVER CAJON CANYON THROUGH BLOOMING YUCCA, ...

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

    VIEW TO THE SOUTH OVER CAJON CANYON THROUGH BLOOMING YUCCA, TOWARDS THE BNSF RAILROAD TRACKS. 124 - Burlington Northern Santa Fe Railroad, Cajon Subdivision, Between Cajon Summit and Keenbrook, Devore, San Bernardino County, CA

  2. View of the Colorado River Canyon form the Nevada side ...

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

    View of the Colorado River Canyon form the Nevada side showing the Nevada rim towers and portions of US 93, view south - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  3. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR...SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.70 Glen Canyon...owned land administered by the National Park Service along the Colorado...

  4. 37. PRATER CANYON AND CIVILIAN CONSERVATION CORPS CAMP SITE FROM ...

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

    37. PRATER CANYON AND CIVILIAN CONSERVATION CORPS CAMP SITE FROM PRATER GRADE, FACING E. SAME CAMERA LOCATION AS No. 35 AND No. 36. - Mesa Verde National Park Main Entrance Road, Cortez, Montezuma County, CO

  5. H CANYON PROCESSING IN CORRELATION WITH FH ANALYTICAL LABS

    SciTech Connect

    Weinheimer, E.

    2012-08-06

    Management of radioactive chemical waste can be a complicated business. H Canyon and F/H Analytical Labs are two facilities present at the Savannah River Site in Aiken, SC that are at the forefront. In fact H Canyon is the only large-scale radiochemical processing facility in the United States and this processing is only enhanced by the aid given from F/H Analytical Labs. As H Canyon processes incoming materials, F/H Labs provide support through a variety of chemical analyses. Necessary checks of the chemical makeup, processing, and accountability of the samples taken from H Canyon process tanks are performed at the labs along with further checks on waste leaving the canyon after processing. Used nuclear material taken in by the canyon is actually not waste. Only a small portion of the radioactive material itself is actually consumed in nuclear reactors. As a result various radioactive elements such as Uranium, Plutonium and Neptunium are commonly found in waste and may be useful to recover. Specific processing is needed to allow for separation of these products from the waste. This is H Canyon's specialty. Furthermore, H Canyon has the capacity to initiate the process for weapons-grade nuclear material to be converted into nuclear fuel. This is one of the main campaigns being set up for the fall of 2012. Once usable material is separated and purified of impurities such as fission products, it can be converted to an oxide and ultimately turned into commercial fuel. The processing of weapons-grade material for commercial fuel is important in the necessary disposition of plutonium. Another processing campaign to start in the fall in H Canyon involves the reprocessing of used nuclear fuel for disposal in improved containment units. The importance of this campaign involves the proper disposal of nuclear waste in order to ensure the safety and well-being of future generations and the environment. As processing proceeds in the fall, H Canyon will have a substantial number of samples being sent to F/H Labs. All analyses of these samples are imperative to safe and efficient processing. The important campaigns to occur would be impossible without feedback from analyses such as chemical makeup of solutions, concentrations of dissolution acids and nuclear material, as well as nuclear isotopic data. The necessity of analysis for radiochemical processing is evident. Processing devoid of F/H Lab's feedback would go against the ideals of a safety-conscious and highly accomplished processing facility such as H Canyon.

  6. CHAMA RIVER CANYON WILDERNESS AND CONTIGUOUS ROADLESS AREA, NEW MEXICO.

    USGS Publications Warehouse

    Ridgley, Jennie L.; Light, Thomas D.

    1984-01-01

    Results of mineral surveys indicate that the Chama River Canyon Wilderness and contiguous roadless area in new Mexico have a probable mineral-resource potential for copper with associated uranium and silver. Gypsum occurs throughout the area, exposed in the canyon walls. Further study of the wilderness should concentrate on exploratory drilling to test the oil and gas potential of Pennsylvanian strata and evaluate vanadium anomalies in the Todilto as a prospecting guide for locating uranium.

  7. Safety Evaluation for Packaging (onsite) T Plant Canyon Items

    SciTech Connect

    OBRIEN, J.H.

    2000-07-14

    This safety evaluation for packaging (SEP) evaluates and documents the ability to safely ship mostly unique inventories of miscellaneous T Plant canyon waste items (T-P Items) encountered during the canyon deck clean off campaign. In addition, this SEP addresses contaminated items and material that may be shipped in a strong tight package (STP). The shipments meet the criteria for onsite shipments as specified by Fluor Hanford in HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments.

  8. Canyon dynamics and related sedimentary impacts off western Portugal

    NASA Astrophysics Data System (ADS)

    Vitorino, J.; Oliveira, A.; Silva, R.; Quaresma, L.; Marreiros, R.

    2003-04-01

    Submarine canyons are areas of increased exchanges between the continental shelf and the deep ocean. We present preliminary results from a multidisciplinary research focussing the dynamics of several canyon systems that occur along the Portuguese continental margin. The research is being conducted in the framework of EU project Eurostrataform and aims to understand the dominant aspects of the interaction between shelf/slope flows and canyons and to relate those aspects with the exportation of sediments from the shelf. The present work is intended to complement results from previous projects that were focussed on the quasi-inertial dynamics of the Portuguese canyon systems. Three contrasting systems are studied: (1) the Nazaré Canyon, a narrow and deep canyon which completely cuts the shelf, with no local riverine sources; (2) the Setubal-Lisbon canyon system, located in an area of complex topography and coastline configuration, with local riverine sources (Tagus and Sado rivers) and (3) the Oporto canyon, which is restricted to the outer shelf and affected by a major riverine source (Douro river). The ongoing program of observations includes multidisciplinary surveys (CTD, ADCP, suspended particle matter measurements, shallow seismic) and both long-term and short-term currentmeter moorings. The observations will cover both the summer upwelling regime as well as the highly energetic winter conditions. Process studies will combine observations and numerical modeling tools through the use of MOCASSIM system, which is presently being developed at Instituto Hidrografico. The system integrates several numerical models and is intended to characterise the wave and current conditions over the study areas.

  9. B-Plant Canyon Ventilation Control System Description

    SciTech Connect

    MCDANIEL, K.S.

    1999-08-31

    Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This document describes the CVCS system components which include a Programmable Logic Controller (PLC) coupled with an Operator Interface Unit (OIU) and application software. This document also includes an Alarm Index specifying the setpoints and technical basis for system analog and digital alarms.

  10. Tensor CSAMT survey over the Sulphur Springs thermal area, Valles Caldera, New Mexico, U.S.A. Part 1: Implications for structure of the western caldera

    SciTech Connect

    Wannamaker, P.E.

    1997-03-01

    An extensive tensor controlled-source audiomagnetotelluric (CSAMT) survey has been carried out over the Sulphur Springs geothermal area, Valles Caldera, New Mexico. Forty-five sites were acquired using two crossed transmitter bipoles placed approximately 13 km south of the center of the survey. The soundings in the Sulphur Springs area were arranged in four profiles to cross major structural features. CSAMT and magnetotelluric (MT) data taken outside Valles Caldera were constrained by drill logs and imply resistive Bandelier Tuff, underlain by conductive Paleozoic sediments, and further underlain by resistive, primarily Precambrian crystalline rocks. Model cross-sections within the caldera were derived using 2-D parameterized inversion constrained by drilling, with layered-earth inversion for starting models. Southeast of the Sulphur Creek fault, the upper 200 m of the section are of relatively low resistivity and correspond to unconsolidated land-slide and debris flows. The Bandelier Tuff below exhibits higher but variable resistivities because of alteration controlled by local faulting. Beneath the Bandelier Tuff, the Paleozoic sedimentary layer is only moderately less resistive than it is outside the caldera, with the lowest values occurring northwest of Sulphur Creek. Its low resistivity per se does not necessarily represent a hydrothermal aquifer. The Sulphur Creek fault appears to be a locus of substantial change in structural relief; upthrow of stratigraphy and basement to its west appears to be about 400--500 m. A major normal fault down to the southeast is located under the topographic expression of Freelove Canyon, which is up to 1 km farther southeast than suggested by previous geologic sections. High resistivities possibly corresponding to a vapor zone in the upper 500 m near VC-2B and VC-2A are not consistent with the CSAMT data.

  11. Submarine canyons: multiple causes and long-time persistence

    SciTech Connect

    Shepard, F.P.

    1981-06-01

    Submarine canyons are of composite origin and that many of the hypotheses suggested in the past were partly correct but did not appreciate that coordination of other processes was required. Thus there is growing evidence that, in the history of many canyons, there was a period in which subaerial erosion was an important precursor, but that present features are predominantly the result of marine erosion. Those advocating turbidity currents as the unique cause of canyons failed to appreciate that debris flows down the incipient valleys, as well as other types of landslides, could be an almost equally important factor in marine erosion. The great effect of biologic activity on the rock walls of incipient canyons has been almost completely neglected in explanations, and various types of currents such as those of the tides have been left largely out of the picture. Perhaps the most important feature absent in these various hypotheses has been the realization that canyons may well be the result of a long period of formation, much longer than the short episodes of Pleistocene glacial sea-level lowering usually considered explanation enough of these giant features which commonly cut into hard crystalline rock. New information is showing that the canyons may date back to at least the Cretaceous. (JMT)

  12. Brighty, donkeys and conservation in the Grand Canyon.

    PubMed

    Wills, John

    2006-09-01

    The Grand Canyon is a vast place. It is almost incomprehensible in size. And yet it can also seem strangely crowded. Millions of tourists flock to the Grand Canyon in northern Arizona every year. In 1999, almost 5 million people visited, the highest figure in Canyon history. And each one of them expected to see a wild, free and untrammelled landscape. Despite the obvious natural resources, this expectation has proved anything but easy to satisfy. The US National Park Service (NPS), responsible for the management of most large North American parks (along with several historic sites and museums), has struggled to make or keep the canyon "grand". Park rangers have grappled with a multitude of issues during the past century, including automobile congestion, drying of the Colorado River and uranium mining inside the park. Conservation has posed a unique set of challenges. On a fundamental level, "restoring" the Grand Canyon to its "original" wilderness setting has proved intensely problematic. In the field of wildlife management, restoring the Canyon to its pre-Columbian splendour has entailed some tough decisions--none more so than a 1976 plan to eliminate a sizeable population of feral burros (wild donkeys) roaming the preserve, animals classified as exotics by the NPS. PMID:16904748

  13. 2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park

    USGS Publications Warehouse

    Melis, Theodore S.; Topping, David J.; Grams, Paul E.; Rubin, David M.; Wright, Scott A.; Draut, Amy E.; Hazel, Joseph E., Jr.; Ralston, Barbara E.; Kennedy, Theodore A.; Rosi-Marshall, Emma; Korman, Josh; Hilwig, Kara D.; Schmit, Lara M.

    2010-01-01

    On March 5, 2008, the Department of the Interior began a 60-hour high-flow experiment at Glen Canyon Dam, Arizona, to determine if water releases designed to mimic natural seasonal flooding could be used to improve downstream resources in Glen Canyon National Recreation Area and Grand Canyon National Park. U.S. Geological Survey (USGS) scientists and their cooperators undertook a wide range of physical and biological resource monitoring and research activities before, during, and after the release. Scientists sought to determine whether or not high flows could be used to rebuild Grand Canyon sandbars, create nearshore habitat for the endangered humpback chub, and benefit other resources such as archaeological sites, rainbow trout, aquatic food availability, and riverside vegetation. This fact sheet summarizes research completed by January 2010.

  14. 77 FR 67391 - Notice of Proposed Supplementary Rules on Public Land in Water Canyon, Humboldt County, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ...Proposed Supplementary Rules on Public Land in Water Canyon, Humboldt County, NV AGENCY...and resources on public land within the Water Canyon Recreation Area. These proposed...restrictions included within the decisions of the Water Canyon Recreation Area Management...

  15. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Appendix to Subpart U of...in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App...the Vicinity of the Grand Canyon National Park, AZ...

  16. SRTM Anaglyph: Pinon Canyon region, Colorado

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Erosional features are prominent in this view of southern Colorado taken by the Shuttle Radar Topography Mission (SRTM). The area covers about 20,000square kilometers and is located about 50 kilometers south of Pueblo, Colorado. The prominent mountains near the left edge of the image are the Spanish Peaks, remnants of a 20 million year old volcano. Rising 2,100 meters (7,000 feet) above the plains to the east, these igneous rock formations with intrusions of eroded sedimentary rock historically served as guiding landmarks for travelers on the Mountain Branch of the Santa Fe Trail.

    Near the center of the image is the Pinon Canyon Maneuver Site, a training area for soldiers of the U.S. Army from nearby Fort Carson. The site supports a diverse ecosystem with large numbers of big and small game, fisheries, non-game wildlife, forest, range land and mineral resources. It is bounded on the east by the dramatic topography of the Purgatoire River Canyon, a 100 meter (328 feet) deep scenic red canyon with flowing streams, sandstone formations and exposed geologic processes.

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

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

    Size: 177.8 x 111.3 kilometers ( 110.5 x 69.2 miles) Location: 37.5 deg. North lat., 104 deg. West lon. Orientation: North toward the top Original Data Resolution: SRTM 1 arcsecond (30 meters or 99 feet) Image Data: Shaded and colored SRTM elevation model

  17. Metamorphic signature of the Gneiss Canyon Shear Zone, Lower Granite Gorge, Grand Canyon, Arizona

    SciTech Connect

    Robinson, K.; Williams, M.L. . Dept. of Geology and Geography)

    1992-01-01

    The Proterozoic orogen in Arizona consists of structural blocks separated by NE trending shear zones. The Gneiss Canyon Shear Zone (GCSZ) is important because it appears to define in part the boundary between the amphibolite facies Yavapai Province and the granulite facies Mojave Province. An early NW striking foliation is clearly visible in many samples from the Lower Granite Gorge (LGG). In Travertine Canyon, east of the GCSZ, pelitic schists contain And-Sil-Crd-Bi and Gar-Sil-Sta-Bi. Mafic rocks exhibit complex phase relations between cummingtonite, anthophyllite, gedrite, garnet, and cordierite. The coexistence of cordierite-cummingtonite is indicative of low pressure metamorphism. Microprobe analyses of garnets reveal prograde growth zoning profiles. Temperature and pressure estimates of peak metamorphism are 550--600 C and 3 kb. Just east of the GCSZ, pelitic assemblages contain Gar-Bi [+-] Sil [+-] Mus, and garnet zoning profiles are flat in the cores. In Spencer Canyon, west of the GCSZ, samples commonly contain Gar-Bi-Sil-Crd, and in many samples cordierite is being replaced by sillimanite. Thermobarometric calculations yield temperature and pressure estimates of 650 C and 3.5 kb. Mineral assemblages and quantitative thermobarometry suggest higher peak metamorphic temperature west of the GCSZ but relatively constant pressures across the LGG. On the east side of the GCSZ, temperatures increase toward the Shear Zone, probably due to the presence of extensive dikes, pods, and veins of variably deformed granite. Peak mineral assemblages are syntectonic with respect to the NE-striking GCSZ fabric. If a suture exists in the LGG, the GCSZ fabrics apparently reflect post-accretionary tectonism, with accretion occurring prior to the peak of metamorphism.

  18. MEVTV Workshop on Tectonic Features on Mars

    NASA Technical Reports Server (NTRS)

    Watters, Thomas R. (editor); Golombek, Matthew P. (editor)

    1989-01-01

    The state of knowledge of tectonic features on Mars was determined and kinematic and mechanical models were assessed for their origin. Three sessions were held: wrinkle ridges and compressional structure; strike-slip faults; and extensional structures. Each session began with an overview of the features under discussion. In the case of wrinkle ridges and extensional structures, the overview was followed by keynote addresses by specialists working on similar structures on the Earth. The first session of the workshop focused on the controversy over the relative importance of folding, faulting, and intrusive volcanism in the origin of wrinkle ridges. The session ended with discussions of the origin of compressional flank structures associated with Martian volcanoes and the relationship between the volcanic complexes and the inferred regional stress field. The second day of the workshop began with the presentation and discussion of evidence for strike-slip faults on Mars at various scales. In the last session, the discussion of extensional structures ranged from the origin of grabens, tension cracks, and pit-crater chains to the origin of Valles Marineris canyons. Shear and tensile modes of brittle failure in the formation of extensional features and the role of these failure modes in the formation of pit-crater chains and the canyons of Valles Marineris were debated. The relationship of extensional features to other surface processes, such as carbonate dissolution (karst) were also discussed.

  19. Discovery of two new large submarine canyons in the Bering Sea

    USGS Publications Warehouse

    Carlson, P.R.; Karl, Herman A.

    1984-01-01

    The Beringian continental margin is incised by some of the world's largest submarine canyons. Two newly discovered canyons, St. Matthew and Middle, are hereby added to the roster of Bering Sea canyons. Although these canyons are smaller and not cut back into the Bering shelf like the five very large canyons, they are nonetheless comparable in size to most of the canyons that have been cut into the U.S. eastern continental margin and much larger than the well-known southern California canyons. Both igneous and sedimentary rocks of Eocene to Pliocene age have been dredged from the walls of St. Matthew and Middle Canyons as well as from the walls of several of the other Beringian margin canyons, thus suggesting a late Tertiary to Quaternary genesis of the canyons. We speculate that the ancestral Yukon and possibly Anadyr Rivers were instrumental in initiating the canyon-cutting processes, but that, due to restrictions imposed by island and subsea bedrock barriers, cutting of the two newly discovered canyons may have begun later and been slower than for the other five canyons. ?? 1984.

  20. Formation of the Grand Canyon 5 to 6 million years ago through integration of older palaeocanyons

    NASA Astrophysics Data System (ADS)

    Karlstrom, Karl E.; Lee, John P.; Kelley, Shari A.; Crow, Ryan S.; Crossey, Laura J.; Young, Richard A.; Lazear, Greg; Beard, L. Sue; Ricketts, Jason W.; Fox, Matthew; Shuster, David L.

    2014-03-01

    The timing of formation of the Grand Canyon, USA, is vigorously debated. In one view, most of the canyon was carved by the Colorado River relatively recently, in the past 5-6 million years. Alternatively, the Grand Canyon could have been cut by precursor rivers in the same location and to within about 200 m of its modern depth as early as 70-55 million years ago. Here we investigate the time of formation of four out of five segments of the Grand Canyon, using apatite fission-track dating, track-length measurements and apatite helium dating: if any segment is young, the old canyon hypothesis is falsified. We reconstruct the thermal histories of samples taken from the modern canyon base and the adjacent canyon rim 1,500 m above, to constrain when the rocks cooled as a result of canyon incision. We find that two of the three middle segments, the Hurricane segment and the Eastern Grand Canyon, formed between 70 and 50 million years ago and between 25 and 15 million years ago, respectively. However, the two end segments, the Marble Canyon and the Westernmost Grand Canyon, are both young and were carved in the past 5-6 million years. Thus, although parts of the canyon are old, we conclude that the integration of the Colorado River through older palaeocanyons carved the Grand Canyon, beginning 5-6 million years ago.

  1. An Experimental Study of Submarine Canyon Evolution on Continental Slopes

    NASA Astrophysics Data System (ADS)

    Lai, S. Y.; Gerber, T. P.; Amblas, D.

    2013-12-01

    Submarine canyons define the morphology of many continental slopes and are conduits for the transport of sediment from shallow to deep water. Though the origin and evolution of submarine canyons is still debated, there is general agreement that sediment gravity flows play an important role. Here we present results from a simple, reduced-scale sandbox experiment designed to investigate how sediment gravity flows generate submarine canyons. In the experiments, gravity flows were modeled using either sediment-free or turbid saline currents. Unconfined flows were released onto an inclined bed of sand bounded on the downstream end by a movable floor that was incrementally lowered during the course of an experiment to produce an escarpment. This design was developed to represent the growth of relief across the continental slope. To monitor canyon evolution on the slope, we placed an overhead DSLR camera to record vivid time-lapse videos. At the end of each experimental stage we scanned the topography by imaging a series of submerged laser stripes, each projected from a motor-driven transverse laser sheet, onto a calibrated Cartesian coordinate system to produce high resolution bathymetry without draining the ambient water. In areas unaffected by the flows, we observe featureless, angle-of-repose submarine slopes formed by retrogressive breaching processes. In contrast, areas influenced by gravity flows cascading across the shelf break are deeply incised by submarine canyons with well-developed channel networks. Our results show that downslope gravity flows and submarine falling base level are both required to produce realistic canyon morphologies at laboratory scale. Though our mechanism for generating relief may be a rather crude analogue for the processes driving slope evolution, we hope our novel approach can stimulate new questions about the coevolution of canyons and slopes and motivate further experimental work to address them.

  2. Is the Valles caldera entering a new cycle of activity?

    SciTech Connect

    Wolff, J.A.; Gardner, J.N.

    1995-05-01

    The Valles caldera formed during two major rhyolitic ignimbrite eruptive episodes (the Bandelier Tuff) at 1.61 and 1.22 Ma, after some 12 m.y. of activity in the Jemez Mountains volcanic field, New Mexico. Several subsequent eruptions between 1.22 and 0.52 Ma produced dominantly high-silica rhyolite lava domes and tephras within the caldera. These were followed by a dormancy of 0.46 m.y. prior to the most recent intracaldera activity, the longest hiatus since the inception of the Bandelier magma system at approximately 1.8 Ma. The youngest volcanic activity at approximately 60 ka produced the SW moat rhyolites, a series of lavas and tuffs that display abundant petrologic evidence of being newly generated melts. Petrographic textures conform closely to published predictions for silicic magmas generated by intrusion of basaltic magma into continental crust. The Valles caldera may currently be the site of renewed silicic magma generation, induced by intrusion of mafic magma at depth. Recent seismic investigations revealed the presence of a large low-velocity anomaly in the lower crust beneath the caldera. The generally aseismic character of the caldera, despite abundant regional seismicity, may be attributed to a heated crustal column, the local effect of 13 m.y. of magmatism and emplacement of mid-crustal plutons. 24 refs., 3 figs.

  3. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. (a) Location. The following area is a security...

  4. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. (a) Location. The following area is a security...

  5. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. (a) Location. The following area is a security...

  6. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. (a) Location. The following area is a security...

  7. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable...Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California. (a) Location. The following area is a security...

  8. Sediment transport in the Mississippi Canyon: the role of currents and storm events on optical variability 

    E-print Network

    Burden, Cheryl A

    1999-01-01

    . Large- and small-particle intermediate nepheloid layers were consistently present in the canyon axis and were not observed on the slope to either side of the canyon. The temporal variability in currents, temperature, and particulate matter was measured...

  9. 76 FR 22670 - Black Hills National Forest, Hell Canyon Ranger District, South Dakota, Vestal Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Forest Service Black Hills National Forest, Hell Canyon Ranger District, South Dakota, Vestal Project..., District Ranger, Black Hills National Forest, Hell Canyon Ranger District, 330 Mount Rushmore Road, Custer, South Dakota 57730. Telephone Number: (605) 673- 4853. E-mail:...

  10. 77 FR 59607 - Black Canyon Hydro, LLC; Notice of Environmental Site Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Black Canyon Hydro, LLC; Notice of Environmental Site Review On Wednesday... proposed Black Canyon Hydroelectric Project. All interested participants should meet at 44937...

  11. 78 FR 79436 - Boulder Canyon Project-Post-2017 Resource Pool

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ...Boulder Canyon Project--Post-2017 Resource Pool AGENCY: Western Area Power Administration...Boulder Canyon Project (BCP) post-2017 resource pool marketing criteria and is calling...established general eligibility criteria and a resource pool (Post-2017 Resource Pool)...

  12. 75 FR 439 - Glen Canyon Dam Adaptive Management Work Group (AMWG)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ...Reclamation Glen Canyon Dam Adaptive Management Work Group (AMWG) AGENCY: Bureau of Reclamation...Federal advisory committee, the Adaptive Management Work Group (AMWG), a Technical Work Group (TWG), a Grand Canyon Monitoring and...

  13. 78 FR 54482 - Charter Renewal, Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-04

    ...Renewal, Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior...for the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group is to provide advice and...

  14. 76 FR 584 - Glen Canyon Dam Adaptive Management Program Work Group (AMWG)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ...Reclamation Glen Canyon Dam Adaptive Management Program Work Group (AMWG) AGENCY: Bureau of Reclamation...Federal advisory committee, the Adaptive Management Work Group (AMWG), a technical work group (TWG), a Grand Canyon Monitoring and...

  15. 76 FR 54487 - Charter Renewal, Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ...Renewal, Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior...for the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group is to advise and to provide...

  16. 75 FR 10308 - Fire Management Plan, Final Environmental Impact Statement, Record of Decision, Grand Canyon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-05

    ...DEPARTMENT OF THE INTERIOR National Park Service Fire Management Plan, Final Environmental Impact...Environmental Impact Statement for the Fire Management Plan, Grand Canyon National...availability of the Record of Decision for the Fire Management Plan, Grand Canyon...

  17. Origin of Hot Creek Canyon, Long Valley caldera, California

    SciTech Connect

    Maloney, N.J. . Dept. of Geological Sciences)

    1993-04-01

    Hot Creek has eroded a canyon some thirty meters deep across the Hot Creek rhyolite flows located in the southeastern moat of Long Valley Caldera. Maloney (1987) showed that the canyon formed by headward erosion resulting from spring sapping along hydrothermally altered fractures in the rhyolite, and the capture of Mammoth Creek. This analysis ignored the continuing uplift of the central resurgent dome. Reid (1992) concluded that the downward erosion of the canyon must have kept pace with the uplift. Long Valley Lake occupied the caldera until 100,000 to 50,000 years before present. The elevation of the shoreline, determined by trigonometric leveling, is 2,166 m where the creek enters the canyon and 2,148 m on the downstream side of the rhyolite. The slope of the strand line is about equal to the stream gradient. The hill was lower and the stream gradient less at the time of stream capture. Rotational uplift increased the stream gradient which increased the rate of downward erosion and formed the V-shaped canyon

  18. Sandwave migration in Monterey Submarine Canyon, Central California

    USGS Publications Warehouse

    Xu, J. P.; Wong, F.L.; Kvitek, R.; Smith, D.P.; Paull, C.K.

    2008-01-01

    Repeated high-resolution multibeam bathymetric surveys from 2002 through 2006 at the head of the Monterey Submarine Canyon reveal a sandwave field along the canyon axis between 20 and 250??m water depth. These sandwaves range in wavelength from 20 to 70??m and 1 to 3??m in height. A quantitative measure was devised to determine the direction of sandwave migration based on the asymmetry of their profiles. Despite appreciable spatial variation the sandwaves were found to migrate in a predominantly down-canyon direction, regardless of season and tidal phases. A yearlong ADCP measurement at 250??m water depth showed that intermittent internal tidal oscillations dominated the high-speed canyon currents (50-80??cm/s), which are not correlated with the spring-neap tidal cycle. Observed currents of 50??cm/s or higher were predominantly down-canyon. Applying a simple empirical model, flows of such magnitudes were shown to be able to generate sandwaves of a size similar to the observed ones. ?? 2007 Elsevier B.V. All rights reserved.

  19. Hudson submarine canyon head offshore New York and New Jersey: A physical and geochemical investigation

    NASA Astrophysics Data System (ADS)

    Rona, Peter; Guida, Vincent; Scranton, Mary; Gong, Donglai; Macelloni, Leonardo; Pierdomenico, Martina; Diercks, Arne-R.; Asper, Vernon; Haag, Scott

    2015-11-01

    Hudson Canyon is the largest shelf-sourced canyon system off the east coast of the United States, and hosts a productive ecosystem that supports key fisheries. Here we report the results of a multi-year interdisciplinary study of the geological, geochemical, and physical oceanographic features and processes in the canyon that underpin that ecosystem. High-resolution multi-beam bathymetric and backscatter data show that the contrasting morphology of the two perpendicularly oriented branches at the head of the Hudson Canyon is indicative of different states of geomorphological activity and sediment transport. Tightly spaced ridges and gullies extend perpendicularly towards the canyon axis from the canyon walls. Numerous depressions are found at the base of the canyon walls or along the canyon axis at depths from 300 m to 600 m. Elevated concentrations of dissolved methane in the water column, where the highest density of depressions occur, suggests that methane is actively venting there. The topography and reflective floors of circular depressions in canyon walls and their association with methane maxima suggest that these represent active methane gas release-collapse pockmarks with carbonate floors. Patterns of irregular, low-relief, reflective depressions on the canyon floor may also represent methane release points, either as gas release or cold-seep features. The presence of methane maxima in a region of strong advective currents suggests continuous and substantial methane supply. Hydrographic observations in the canyon show that multiple layers of distinct inter-leaved shelf (cold, fresh) and slope (warm, salty) water masses occupy the head of the canyon during the summer. Their interactions with the canyon and with each other produce shifting fronts, internal waves, and strong currents that are influenced by canyon topography. Strong tidal currents with along-canyon-axis flow shear help to drive the advection, dispersion and mixing of dissolved materials in the water column that likely help support the rich canyon ecosystem.

  20. Directed urban canyons in megacities and its applications in meteorological modeling

    NASA Astrophysics Data System (ADS)

    Samsonov, Timofey; Konstantinov, Pavel; Varentsov, Mikhail

    2015-04-01

    Directed urban canyons study applies object-oriented analysis to extraction of urban canyons and introduces the concept of directed urban canyon which is then experimentally applied in urban meteorological modeling. Observation of current approach to description of urban canyon geometry is provided. Then a new theoretical approach to canyon delineation is presented that allows chaining the spaces between buildings into directed canyons that comprise three-level hierarchy. An original methodology based on triangular irregular network (TIN) is presented that allows extraction of regular and directed urban canyons from cartographic data, estimation of their geometric characteristics, including local and averaged height-width ratio, primary and secondary canyon directions. Obtained geometric properties of canyons are then applied in micro-scale temperature and wind modeling using URB-MOS model and estimation of possible wind accelerations along canyons. Extraction and analysis of directed canyons highly depends on the presence of linear street network. Thus, in the absence of this GIS layer, it should be reconstructed from another data sources. The future studies should give us an answer to the question, where the limits of directed canyons are and how they can be classified further in terms of the street longitudinal shape. For now all computations are performed in separate scripts and programs. We plan to develop comprehensive automation of described methods of urban canyon description in specialized software. The most perspective extension of proposed methodology seemes to be canyon -based analysis which is truely object-oriented. Various geometric properties of micro-, meso- and macro-scale canyons should be investigated and their applicability in urban climate modeling should be assesed. Object-oriented canyon analysis can also be applied in architectural studies, urban morphology, planning and various physical and social aspects that are concerned with human in urban space. Acknowledgements This study was supported by Russian Foundation for Basic Research grant 13-05-41306-RGO_a.

  1. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake...

  2. 75 FR 26098 - Safety Zone; Under Water Clean Up of Copper Canyon, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Under Water Clean Up of Copper Canyon, Lake... establishing a temporary safety zone on the navigable waters of Lake Havasu in the Copper Canyon in support of the underwater cleanup of Copper Canyon. This temporary safety zone is necessary to provide for...

  3. 78 FR 42799 - Glen Canyon Dam Adaptive Management Work Group Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group Meetings AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work... AMWG, a technical work group (TWG), a Grand Canyon Monitoring and Research Center, and...

  4. 78 FR 54482 - Charter Renewal, Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-04

    ... Bureau of Reclamation Charter Renewal, Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of... the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group... Canyon Dam Adaptive Management Work Group is in the public interest in connection with the performance...

  5. 76 FR 54487 - Charter Renewal, Glen Canyon Dam Adaptive Management Work Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Bureau of Reclamation Charter Renewal, Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of... the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group... of the Glen Canyon Dam Adaptive Management Work Group is in the public interest in connection...

  6. Engineering Geologic Assessment of Risk to Visitors: Canyon Lake Gorge, Texas 

    E-print Network

    Kolkmeier, Benjamin D.

    2010-07-14

    Presented here are the results of a study of geological hazards conducted in Canyon Lake Gorge of Central Texas. Canyon Lake Gorge formed in 2002 when the emergency spillway of Canyon Lake was overtopped. Since that time, the gorge has been opened...

  7. 76 FR 28766 - Black Canyon Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... Energy Regulatory Commission Black Canyon Hydro, LLC; Notice of Preliminary Permit Application Accepted..., Black Canyon Hydro, LLC filed an application for a preliminary permit, pursuant to section 4(f) of the Federal Power Act (FPA), proposing to study the feasibility of the Black Canyon Hydroelectric...

  8. 251USDA Forest Service Gen. Tech. Rep. PSW-GTR-160. 1997. Sunshine Canyon Mitigation Oaks--

    E-print Network

    251USDA Forest Service Gen. Tech. Rep. PSW-GTR-160. 1997. Sunshine Canyon Mitigation Oaks the Sunshine Canyon Landfill located on the north side of the San Fernando Valley, CA. The extension plans the foundation for the success of this project. Sunshine Canyon Landfill is a large sanitary waste facility

  9. 75 FR 26098 - Safety Zone; Under Water Clean Up of Copper Canyon, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ...1625-AA00 Safety Zone; Under Water Clean Up of Copper Canyon, Lake Havasu, AZ AGENCY: Coast...the navigable waters of Lake Havasu in the Copper Canyon in support of the underwater cleanup of Copper Canyon. This temporary safety zone is...

  10. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Sequoia and Kings Canyon National Parks. 7...OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon National Parks. ...apply to the privately owned lands within Sequoia and Kings Canyon National Parks....

  11. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Sequoia and Kings Canyon National Parks. 7...OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon National Parks. ...apply to the privately owned lands within Sequoia and Kings Canyon National Parks....

  12. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Sequoia and Kings Canyon National Parks. 7...OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon National Parks. ...apply to the privately owned lands within Sequoia and Kings Canyon National Parks....

  13. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Sequoia and Kings Canyon National Parks. 7...OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon National Parks. ...apply to the privately owned lands within Sequoia and Kings Canyon National Parks....

  14. Measuring currents in submarine canyons: technological and scientific progress in the past 30 years

    USGS Publications Warehouse

    Xu, J. P.

    2011-01-01

    The development and application of acoustic and optical technologies and of accurate positioning systems in the past 30 years have opened new frontiers in the submarine canyon research communities. This paper reviews several key advancements in both technology and science in the field of currents in submarine canyons since the1979 publication of Currents in Submarine Canyons and Other Sea Valleys by Francis Shepard and colleagues. Precise placements of high-resolution, high-frequency instruments have not only allowed researchers to collect new data that are essential for advancing and generalizing theories governing the canyon currents, but have also revealed new natural phenomena that challenge the understandings of the theorists and experimenters in their predictions of submarine canyon flow fields. Baroclinic motions at tidal frequencies, found to be intensified both up canyon and toward the canyon floor, dominate the flow field and control the sediment transport processes in submarine canyons. Turbidity currents are found to frequently occur in active submarine canyons such as Monterey Canyon. These turbidity currents have maximum speeds of nearly 200 cm/s, much smaller than the speeds of turbidity currents in geological time, but still very destructive. In addition to traditional Eulerian measurements, Lagrangian flow data are essential in quantifying water and sediment transport in submarine canyons. A concerted experiment with multiple monitoring stations along the canyon axis and on nearby shelves is required to characterize the storm-trigger mechanism for turbidity currents.

  15. Habitat associations of deep-water rockfishes in a submarine canyon: an example of

    E-print Network

    625 Habitat associations of deep-water rockfishes in a submarine canyon: an example of a natural of high relief interspersed with mud in deep water of narrow submarine canyons are less accessible (genus Se- bastes) and associated habitats in deep water was conducted in Soquel Sub- marine Canyon

  16. Morphodynamics in sediment-starved inner-shelf submarine canyons (Lower St. Lawrence Estuary, Eastern Canada)

    E-print Network

    Morphodynamics in sediment-starved inner-shelf submarine canyons (Lower St. Lawrence Estuary Available online 3 September 2014 Keywords: Submarine canyons Inner-shelf Internal waves Slope failures in a series of inner-shelf submarine canyons located in the Lower St. Lawrence Estuary were examined using

  17. SUBMARINE CANYONS: HOTSPOTS OF DEEP-SEA BENTHIC ABUNDANCE AND BIODIVERSITY

    E-print Network

    Qiu, Bo

    SUBMARINE CANYONS: HOTSPOTS OF DEEP-SEA BENTHIC ABUNDANCE AND BIODIVERSITY A DISSERTATION SUBMITTED and photographic footage. The study of submarine canyons off the main and northwest Hawaiian islands was supported submersibles within the challenging environment of the submarine canyons and the captain and crew of the R/V Ka

  18. Effects of tributary debris on the longitudinal profile of the Colorado River in Grand Canyon

    E-print Network

    Effects of tributary debris on the longitudinal profile of the Colorado River in Grand Canyon January 2006; published 17 June 2006. [1] The Colorado River in Grand Canyon has long been known debris flow activity in Grand Canyon. At all wavelengths the most likely cause for these river profile

  19. Magnitude and Frequency Data for Historic Debris Flows in Grand Canyon

    E-print Network

    Magnitude and Frequency Data for Historic Debris Flows in Grand Canyon National Park and Vicinity with the BUREAU OF RECLAMATION #12;Magnitude and Frequency Data for Historic Debris Flows in Grand Canyon National.............................................................................................................................. 6 Debris flows in Grand Canyon National Park

  20. Debris flow deposition and reworking by the Colorado River in Grand Canyon, Arizona

    E-print Network

    Debris flow deposition and reworking by the Colorado River in Grand Canyon, Arizona Brian J reworking to limit the rate of debris fan aggradation in Grand Canyon. Citation: Yanites, B. J., R. H. Webb in Grand Canyon, Arizona, Water Resour. Res., 42, W11411, doi:10.1029/2005WR004847. 1. Introduction [2

  1. 76 FR 23623 - Backcountry Management Plan, Environmental Impact Statement, Grand Canyon National Park, Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ... National Park Service Backcountry Management Plan, Environmental Impact Statement, Grand Canyon National... prepare an Environmental Impact Statement for the Backcountry Management Plan, Grand Canyon National Park... for Grand Canyon National Park. This plan will help guide park decisions on protecting natural...

  2. 76 FR 28766 - Black Canyon Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ...Project No. 14110-000] Black Canyon Hydro, LLC; Notice...Applications On March 14, 2011, Black Canyon Hydro, LLC filed an...study the feasibility of the Black Canyon Hydroelectric Project...otherwise enter upon lands or waters owned by others without...

  3. 76 FR 12727 - Black Canyon Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ...Project No. 14087-000] Black Canyon Hydro, LLC; Notice...Applications On January 26, 2011, Black Canyon Hydro, LLC filed an...study the feasibility of the Black Canyon Pumped Storage Project...otherwise enter upon lands or waters owned by others without...

  4. Ausonia Cavus and Kasei Valles: Complementary Exploration Zone Sites for Biology, Geology and ISRU

    NASA Astrophysics Data System (ADS)

    Hamilton, J. C.; Lundblad, S.; Clark, D. L.; Purves, N. G.; Milovsoroff, C. T.; Thomas, N.

    2015-10-01

    Two complementary EZs are proposed that are rich in geologic history and exhibit water evidence for astrobiology. Both sit midway down flow features in erosional valley networks. These are Ausonia Cavus (paleolake) and Kasei Valles (flow channel).

  5. The Hebrus Valles Exploration Zone: Access to the Martian Surface and Subsurface

    NASA Astrophysics Data System (ADS)

    Davila, A.; Fairén, A. G.; Rodríguez, A. P.; Schulze-Makuch, D.; Rask, J.; Zavaleta, J.

    2015-10-01

    The Hebrus Valles EZ represents a diverse setting with multiple geological contacts and layers, possible remnant water ice and protected subsurface environments, which could be critical for the establishment of long-term human settlements.

  6. Small-scale turbidity currents in a big submarine canyon

    USGS Publications Warehouse

    Xu, Jingping; Barry, James P.; Paull, Charles K.

    2013-01-01

    Field measurements of oceanic turbidity currents, especially diluted currents, are extremely rare. We present a dilute turbidity current recorded by instrumented moorings 14.5 km apart at 1300 and 1860 m water depth. The sediment concentration within the flow was 0.017%, accounting for 18 cm/s gravity current speed due to density excess. Tidal currents of ?30 cm/s during the event provided a "tailwind" that assisted the down-canyon movement of the turbidity current and its sediment plume. High-resolution velocity measurements suggested that the turbidity current was likely the result of a local canyon wall slumping near the 1300 m mooring. Frequent occurrences, in both space and time, of such weak sediment transport events could be an important mechanism to cascade sediment and other particles, and to help sustain the vibrant ecosystems in deep-sea canyons.

  7. Origin of Izu-Bonin forearc submarine canyons

    SciTech Connect

    Fujioka, Kantaro ); Yoshida, Haruko )

    1990-06-01

    Submarine canyons on the Izu-Bonin forearc are morphologically divided from north to south into four types based on their morphology, long profiles, and seismic profiles: Mikura, Aogashima, Sofu, and Chichijima types, respectively. These types of canyons are genetically different from each other. Mikura group is formed by the faults related to bending of the subducting Philippine Sea Plate. Aogashima type genetically relates to the activity of large submarine calderas that supply large amounts of volcaniclastic material to the consequent forearc slope. The third, Sofu group, is thought to be formed by the large-scale mega mass wasting in relation to the recent movement of the Sofugan tectonic line. The last, Chichijima group, is formed by collision of the Uyeda Ridge and the Ogasawara Plateau on the subducting Pacific Plate with Bonin Arc. Long profiles of four types of submarine canyons also support this.

  8. Human Jamestown canyon virus infection --- Montana, 2009.

    PubMed

    2011-05-27

    Jamestown Canyon virus (JCV) is a mosquito-borne zoonotic pathogen belonging to the California serogroup of bunyaviruses. Although JCV is widely distributed throughout temperate North America, reports of human JCV infection in the United States are rare. This is the first report of human JCV infection detected in Montana, one of only 15 cases reported in the United States since 2004, when JCV became reportable. On May 26, 2009, a man aged 51 years with no travel history outside of Montana went to a local emergency department immediately following onset of fever, severe frontal headache, dizziness, left-sided numbness, and tingling. His blood pressure was elevated. Stroke was ruled out, oxygen was administered, medication was prescribed for hypertension, and the patient was sent home. One week later, the patient visited his primary-care physician complaining of continued neurologic symptoms consistent with acute febrile encephalitis and recent mosquito bites. Although West Nile virus (WNV) disease was diagnosed based on detection of WNV-immunoglobulin M (IgM) and G (IgG) antibodies, subsequent testing indicated that the WNV antibodies were from a past infection and that his illness was caused by JCV. The final diagnosis of JCV infection was based on positive JCV-specific IgM enzyme-linked immunosorbent assay (ELISA) results and a fourfold rise in paired sample JCV plaque reduction neutralization test (PRNT) titers. This finding represents a previously unrecognized risk for JCV infection in Montana; clinicians should consider JCV infection when assessing patients for suspected arboviral infections. PMID:21617630

  9. Paleogene canyons of Tethyan margin and their hydrocarbon potential, Czechoslovakia

    SciTech Connect

    Picha, F.J. )

    1991-03-01

    Two Paleogene canyons buried below the Neogene foredeep and the Carpathian thrust belt in Southern Moravia have been outlined by drilling and seismic profiling. The features, as much as 12 km wide and over 1000 m deep, have been traced for 40 km. They are cut into Mesozoic and Paleozoic carbonate and clastic deposits and underlying Precambrian crystalline rocks. The sedimentary fill is made of late Eocene and early oligocene marine deposits, predominantly silty mudstones and siltstones. Sandstones and conglomerates are distributed mainly in the lower axial part of the valleys. Proximal and distal turbidites, grain-flow and debris-flow deposits have been identified in the fill. The common occurrence of slump folds, pebbly mudstones, and chaotic slump deposits indicate that mass movement played a significant role in sediment transport inside the canyons. The canyons are interpreted as being cut by rivers, then submerged and further developed by submarine processes. The organic rich mudstones of the canyon fill are significant source rocks (1-10% TOC). They reached the generative stage only after being tectonically buried below the Carpathian thrust belt in middle Miocene time. Channelized sandstones and proximal turbidities provide reservoirs of limited extent, although more substantial accumulations of sands are possible further downslope at the mouth of these canyons. Several oil fields have been discovered both within the canyon fill and the surrounding rocks. Similar Paleogene valleys may be present elsewhere along the ancient Tethyan margins buried below the Neogene foredeeps and frontal zones of the Alps and Carpathians. Their recognition could prove fruitful in the search for hydrocarbons.

  10. Regional economic impacts of Grand Canyon river runners.

    PubMed

    Hjerpe, Evan E; Kim, Yeon-Su

    2007-10-01

    Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy recommendations are given for increasing the regional retention of rafting expenditures and for understanding both the beneficial and adverse impacts that accompany outdoor recreation in rural areas. PMID:17070647

  11. Review of the Diablo Canyon probabilistic risk assessment

    SciTech Connect

    Bozoki, G.E.; Fitzpatrick, R.G.; Bohn, M.P.; Sabek, M.G.; Ravindra, M.K.; Johnson, J.J.

    1994-08-01

    This report details the review of the Diablo Canyon Probabilistic Risk Assessment (DCPRA). The study was performed under contract from the Probabilistic Risk Analysis Branch, Office of Nuclear Reactor Research, USNRC by Brookhaven National Laboratory. The DCPRA is a full scope Level I effort and although the review touched on all aspects of the PRA, the internal events and seismic events received the vast majority of the review effort. The report includes a number of independent systems analyses sensitivity studies, importance analyses as well as conclusions on the adequacy of the DCPRA for use in the Diablo Canyon Long Term Seismic Program.

  12. Recent sediment studies refute Glen Canyon Dam hypothesis

    USGS Publications Warehouse

    Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

    2002-01-01

    Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

  13. Reviewing the success of intentional flooding of the Grand Canyon

    SciTech Connect

    Wirth, B.D.

    1997-04-01

    A description and evaluation of the results of an intentional flooding experiment at the Grand Canyon are described. The purpose of the 7-day release of flood waters from the Glen Canyon Dam was to determine if managed floods have the ability to predictably restore the riverine environment. A summary of environmental conditions leading to the experiment is provided and flood results are listed. Initial results showed significant improvement in the size and number of the river`s beaches, creation of backwater habitat for endangered species, and no adverse impact to the trout fishery, Indian cultural sites, and other resources.

  14. Early Agriculture in the Eastern Grand Canyon of Arizona, USA

    USGS Publications Warehouse

    Davis, S.W.; Davis, M.E.; Lucchitta, I.; Finkel, R.; Caffee, M.

    2000-01-01

    Abandoned fields in Colorado River alluvium in the eastern Grand Canyon show signs of primitive agriculture. Presence of maize pollen in association with buried soils near Comanche Creek suggests that farming began prior to 3130 yr B.P. Cotton pollen, identified in buried soils near Nankoweap Creek, dates to 1310 yr B.P., approximately 500 years earlier than previously reported anywhere on the Colorado Plateau. Farming spanned three millennia in this reach of the canyon. Entrenchment, starting approximately 700 yr B.P., making water diversion to fields infeasible, was likely responsible for field abandonment. ?? 2000 John Wiley & Sons, Inc.

  15. Are amphitheater headed canyons indicative of a particular formative process?

    NASA Astrophysics Data System (ADS)

    Ryan, A. J.; Whipple, K. X.; Johnson, J. P.

    2012-12-01

    Tributary canyons with amphitheater-shaped heads have previously been interpreted as evidence for groundwater seepage erosion, particularly in environments where fluvial processes are assumed to be negligible. However, some have questioned whether this canyon morphology is truly diagnostic of a particular formative process. We seek to determine the relative roles of fluvial and groundwater-related processes and the strength of stratigraphic control on the Colorado Plateau through a combination of fieldwork and GIS analysis. Amphitheater valleys may have overhanging or steep-sided headwalls with a semicircular plan-view pattern. It is reasonable to assume that this form is a result of focused erosion at the base of the headwall (i.e. sapping). Two frequently cited agents may lead to undermining: plunge-pool scour at the base of waterfalls and seepage induced weathering and erosion where the groundwater table intersects the land surface. Both processes are enhanced where weaker, less permeable layers underlie stronger cap rock. We conducted preliminary fieldwork in two locations on the Colorado Plateau, where there are many classic examples of amphitheater headed canyons. The Escalante River landscape is highly variable with a range of canyon and valley-head forms, many of which cut through the thick Navajo Sandstone into the underlying shale and sand of the Kayenta Formation. Northeast of Escalante National Monument, at the base of the Henry Mountains, is Tarantula Mesa. The canyons there are also considerably variable, with nearly all containing at least one abrupt amphitheater knickpoint at the valley head or farther downstream. Our observations are presented here with an analysis of the canyon profiles, surrounding topography, and potential structural controls. We have found that nearly all amphitheaters in both locales show signs of groundwater seepage weathering and plausibly seepage erosion. However, many also contain plunge pools and evidence of substantial fluvial activity. In most cases, variability in amphitheater scale and location relates to the geometry of exposed strata, suggesting that contrasting, bimodal stratigraphy (i.e. strong, more permeable layer over weaker, less permeable layer) is required for amphitheater formation. This is particularly evident in Tarantula Mesa, where variations in the stratigraphy of the Tarantula Mesa Sandstone strongly influence canyon location and morphology. Amphitheaters form only where a thick, strong sandstone body is exposed in the headwaters of the drainage. Typical v-shaped canyon morphologies are seen nearby in otherwise identical drainages where the sandstone is interbedded with shale.

  16. Multi-stage uplift of the Colorado Plateau and the age of Grand Canyon and precursor canyons

    NASA Astrophysics Data System (ADS)

    Karlstrom, K. E.; Lee, J. P.; Kelley, S. A.; Crow, R.

    2012-12-01

    Debates about the age of Grand Canyon link to debates about the timing of surface uplift(s) of the Colorado Plateau- Rocky Mountain (CP-RM) region. One "old Grand Canyon" model proposes that a paleocanyon of almost the same depth and location as today's Grand Canyon was carved by a NE-flowing "California" paleoriver 80-70 Ma, then was re-used at ~55 Ma by a SW-flowing "Arizona" paleoriver. This model postulates the CP-RM region was uplifted to near modern elevations during the Laramide orogeny. A second model postulates a 17 Ma Grand Canyon; this time corresponds to Basin and Range extension and postulated mantle-driven surface uplift. The "young Grand Canyon" model postulates that >2/3 of modern Grand Canyon was carved by W-flowing Colorado River that became integrated to the Gulf of California at 5-6 Ma during Neogene mantle-driven uplift of the CP/RM region. Thermochronologic data are poised to substantially resolve these debates. Our thermochronology dataset combines published and new apatite fission-track and helium analyses, and joint thermal history modeling using both systems. This dataset reveals three major cooling episodes: 1) a multi-stage Sevier-Laramide contraction episode from about 90 Ma to 50 Ma with structural relief on upwarps on the order 0.5-1 km, compatible with a similar magnitude of surface uplift; 2) 30-20 Ma cooling that was associated with denudation and northward cliff retreat of most of the Mesozoic section from Grand Canyon region; 3) <10 Ma cooling that is best documented in eastern Grand Canyon as part of a general pattern of decreasing age of cooling/denudation to the NE. Combined geologic and thermochronologic data define the age and 3-D geometry of Cenozoic paleotopography that led to Grand Canyon carving. Combined AHe and AFT data indicate 2-4 km of sedimentary rocks covered the Grand Canyon region until about 40 Ma, negating the California River model. These strata were not removed from the Marble Canyon area until after about 25 Ma, negating the Arizona River hypothesis. However, significant paleorelief and paleovalleys were present and their geometry is coming into focus. 1) A long-recognized N-flowing "Peach Springs paleocanyon" existed from Eocene to about 17 Ma and potentially helped carve a paleocanyon along the Hurricane fault, from Truxton to river mile (RM) 225-190. Drill data and modern topography suggest that the NE slope of this paleodrainage has been inverted to a modern SW slope by surface tilting of the CP. 2) An "East Kaibab" paleocanyon was carved across the southern Kaibab uplift to below the Kaibab surface during 30-20 Ma exhumation. This Miocene paleocanyon extended from RM 65 to 116 in the present position of Upper Granite Gorge and may have flowed west (Crooked Ridge River) or east (as an outlet for the 18 Ma Peach Springs paleocanyon). These data support a model of multiple exhumation episodes leading to a 5-6 Ma Grand Canyon that was mainly carved by the W-flowing Colorado River, but that re-used and deepened older paleovalley segments

  17. Giant submarine canyons: is size any clue to their importance in the rock record?

    USGS Publications Warehouse

    Normark, William R.; Carlson, Paul R.

    2003-01-01

    Submarine canyons are the most important conduits for funneling sediment from continents to oceans. Submarine canyons, however, are zones of sediment bypassing, and little sediment accumulates in the canyon until it ceases to be an active conduit. To understand the potential importance in the rock record of any given submarine canyon, it is necessary to understand sediment-transport processes in, as well as knowledge of, deep-sea turbidite and related deposits that moved through the canyons. There is no straightforward correlation between the final volume of the sedimentary deposits and size o fthe associated submarine canyons. Comparison of selected modern submarine canyons together with their deposits emphasizes the wide range of scale differences between canyons and their impact on the rock record. Three of the largest submarine canyons in the world are incised into the Beringian (North American) margin of the Bering Sea. Zhemchug Canyon has the largest cross-section at the shelf break and greatest volume of incision of slope and shelf. The Bering Canyon, which is farther south in the Bering Sea, is first in length and total area. In contrast, the largest submarine fans-e.g., Bengal, Indus, and Amazon-have substantially smaller, delta-front submarine canyons that feed them; their submarine drainage areas are one-third to less than one-tenth the area of Bering Canyon. some very large deep-sea channells and tubidite deposits are not even associated with a significant submarine canyon; examples include Horizon Channel in the northeast Pacific and Laurentian Fan Valley in the North Atlantic. Available data suggest that the size of turbidity currents (as determined by volume of sediment transported to the basins) is also not a reliable indicator of submarine canyon size.

  18. Submarine canyons as important habitat for cetaceans, with special reference to the Gully: A review

    NASA Astrophysics Data System (ADS)

    Moors-Murphy, Hilary B.

    2014-06-01

    There has been much research interest in the use of submarine canyons by cetaceans, particularly beaked whales (family Ziphiidae), which appear to be especially attracted to canyon habitats in some areas. However, not all submarine canyons are associated with large numbers of cetaceans and the mechanisms through which submarine canyons may attract cetaceans are not clearly understood. This paper reviews some of the cetacean associations with submarine canyons that have been anecdotally described or presented in scientific literature and discusses the physical, oceanographic and biological mechanisms that may lead to enhanced cetacean abundance around these canyons. Particular attention is paid to the Gully, a large submarine canyon and Marine Protected Area off eastern Canada for which there exists some of the strongest evidence available for submarine canyons as important cetacean habitat. Studies demonstrating increased cetacean abundance in the Gully and the processes that are likely to attract cetaceans to this relatively well-studied canyon are discussed. This review provides some limited evidence that cetaceans are more likely to associate with larger canyons; however, further studies are needed to fully understand the relationship between the physical characteristics of canyons and enhanced cetacean abundance. In general, toothed whales (especially beaked whales and sperm whales) appear to exhibit the strongest associations with submarine canyons, occurring in these features throughout the year and likely attracted by concentrating and aggregating processes. By contrast, baleen whales tend to occur in canyons seasonally and are most likely attracted to canyons by enrichment and concentrating processes. Existing evidence thus suggests that at least some submarine canyons are important foraging areas for cetaceans, and should be given special consideration for cetacean conservation and protection.

  19. Surprise and Opportunity for Learning in Grand Canyon: the Glen Canyon Dam Adaptive Management Program

    NASA Astrophysics Data System (ADS)

    Melis, T. S.; Walters, C. J.; Korman, J.

    2013-12-01

    With a focus on resources of the Colorado River ecosystem downstream of Glen Canyon Dam in Glen Canyon National Recreation Area (GCNRA) and Grand Canyon National Park (GCNP) of northern Arizona, the Glen Canyon Dam Adaptive Management Program has evaluated experimental flow and nonflow policy tests since 1990. Flow experiments have consisted of a variety of water releases from the dam within pre-existing annual downstream delivery agreements. The daily experimental dam operation, termed the Modified Low Fluctuating Flow (MLFF), implemented in 1996 to increase daily low flows and decrease daily peaks were intended to limit daily flow range to conserve tributary sand inputs and improve navigation among other objectives, including hydropower energy. Other flow tests have included controlled floods with some larger releases bypassing the dam's hydropower plant to rebuild and maintain eroded sandbars in GCNP. Experimental daily hydropeaking tests beyond MLFF have also been evaluated for managing the exotic recreational rainbow trout fishery in the dam's GCNRA tailwater. Experimental nonflow policies, such as physical removal of exotic fish below the tailwater, and experimental translocation of endangered native humpback chub from spawning habitats in the Little Colorado River (the largest natal origin site for chub in the basin) to other tributaries within GCNP have also been monitored. None of these large-scale field experiments has yet produced unambiguous results in terms of management prescriptions, owing to inadequate monitoring programs and confounding of treatment effects with effects of ongoing natural changes; most notably, a persistent warming of the river resulting from reduced storage in the dam's reservoir after 2003. But there have been several surprising results relative to predictions from models developed to identify monitoring needs and evaluate experimental design options at the start of the adaptive ecosystem assessment and management program in 1997. The repeated surprises were initially viewed with dismay by some managers and stakeholders who had unrealistic expectations about science and modeling to start with, yet actually represent scientific successes in terms of revealing new opportunities for developing better flow and non-flow policies. A new Long Term Experiment and Management Plan EIS (see URL) started in 2011, and co-led by the U.S. Department of the Interior's Bureau of Reclamation and the National Park Service, is underway and provides Colorado River managers, other stakeholders and the public a unique opportunity to refocus and weight resource objectives, conduct trade-off evaluations within the context of structured decision analyses, and identify key uncertainties with the goal of improving past experimental designs and monitoring strategies so as to take advantage of future learning opportunities over the next two decades. Perhaps the single greatest uncertainty now facing river managers is trying to anticipate how climate change and global warming will affect the supply of water from the Upper Colorado River Basin, Lake Powell storage that is known to control the river's thermal regime and native and nonnative fish interactions in GCNP, and the already highly-limited tributary sand supply below the dam from the Paria and Little Colorado Rivers required to manage sandbars along river shorelines.

  20. An analysis of the potential for Glen Canyon Dam releases to inundate archaeological sites in the Grand Canyon, Arizona

    USGS Publications Warehouse

    Sondossi, Hoda A.; Fairley, Helen C.

    2014-01-01

    The development of a one-dimensional flow-routing model for the Colorado River between Lees Ferry and Diamond Creek, Arizona in 2008 provided a potentially useful tool for assessing the degree to which varying discharges from Glen Canyon Dam may inundate terrestrial environments and potentially affect resources located within the zone of inundation. Using outputs from the model, a geographic information system analysis was completed to evaluate the degree to which flows from Glen Canyon Dam might inundate archaeological sites located along the Colorado River in the Grand Canyon. The analysis indicates that between 4 and 19 sites could be partially inundated by flows released from Glen Canyon Dam under current (2014) operating guidelines, and as many as 82 archaeological sites may have been inundated to varying degrees by uncontrolled high flows released in June 1983. Additionally, the analysis indicates that more of the sites currently (2014) proposed for active management by the National Park Service are located at low elevations and, therefore, tend to be more susceptible to potential inundation effects than sites not currently (2014) targeted for management actions, although the potential for inundation occurs in both groups of sites. Because of several potential sources of error and uncertainty associated with the model and with limitations of the archaeological data used in this analysis, the results are not unequivocal. These caveats, along with the fact that dam-related impacts can involve more than surface-inundation effects, suggest that the results of this analysis should be used with caution to infer potential effects of Glen Canyon Dam on archaeological sites in the Grand Canyon.

  1. Structure-Forming Corals and Sponges and Their Use as Fish Habitat in Bering Sea Submarine Canyons

    E-print Network

    California at Santa Barbara, University of

    Structure-Forming Corals and Sponges and Their Use as Fish Habitat in Bering Sea Submarine Canyons and Their Use as Fish Habitat in Bering Sea Submarine Canyons. PLoS ONE 7(3): e33885. doi:10.1371/journal settings that can include canyons, seamounts, and banks. Two of the largest canyons in the world, Zhemchug

  2. Hatteras Transverse Canyon, Hatteras Outer Ridge and environs of the U.S. Atlantic margin: A view from multibeam bathymetry

    E-print Network

    New Hampshire, University of

    B.V. All rights reserved. 1. Introduction A submarine canyon that strikes roughly parallel. In fact, transverse submarine canyons are so rare that the review of the global distribution and geomorphologies of sub- marine canyons by Harris and Whiteway (2011) does not mention one submarine canyon

  3. Morphology, evolution and fill: Implications for sand and mud distribution in filling deep-water canyons and slope

    E-print Network

    Mazzini, Adriano

    and sedimentary activity, of a deeply incised submarine canyon system, the Donegal Bay submarine canyon-water canyons and slope channel complexes Bryan T. Cronin a,*, Andrey M. Akhmetzhanov b , Adriano Mazzini. The survey produced superb 3D profiling of the canyon along its entire length, marking a transition from

  4. Habitat characterization of deep-water coral reefs in La Gaviera Canyon (Avilés Canyon System, Cantabrian Sea)

    NASA Astrophysics Data System (ADS)

    Sánchez, Francisco; González-Pola, Cesar; Druet, María; García-Alegre, Ana; Acosta, Juan; Cristobo, Javier; Parra, Santiago; Ríos, Pilar; Altuna, Álvaro; Gómez-Ballesteros, María; Muñoz-Recio, Araceli; Rivera, Jesus; del Río, Guillermo Díaz

    2014-08-01

    Surveys conducted at the complex Avilés Canyon System (southern Bay of Biscay) in order to identify vulnerable habitats and biological communities revealed the presence of noteworthy deep-water coral reefs in one of the tributaries of the system (La Gaviera Canyon). The aim of the present study is to determine why this deep-sea canyon provides suitable environmental conditions for corals to grow. This hanging canyon is characterized by an irregular U-shaped floor with two narrow differentiated flanks. Sand ripples and rocky outcrops structured in diverse W-E directed steps are observed on the canyon floor, suggesting intense hydrodynamic activity. Accordingly, high-frequency near-bottom current and thermal structure profiles showed that there occur strong shifts in currents/hydrography behaving as front-like features at each tidal cycle. These involve the sudden increase of along-axis velocities to over 50 cm/s and vertical velocities of over 5 cm/s in each tidal cycle associated with the passage of sharp thermal fronts and thermal inversions suggesting overturning. A year-long near-bottom current record showed events with near-bottom velocities well over 1 m/s lasting for several days. Three cold-water coral settings were distinguished: a dense coral reef located on stepped rocky bottoms of the eastern and western flanks, carbonate mounds (20-30 m high) located on the canyon floor, and a cluster of shallower water dead coral framework at the head sector of the canyon. Video and still images from a towed sled and ROV verified the presence of dropstones and rippled sand sheets surrounding the mounds and revealed changes in the coral population (alive or dead; total or patchy coverage) in coral reef and carbonate mound areas. The dominant species of the reef are Lophelia pertusa and Madrepora oculata, which considerably increase the habitat?s complexity and biodiversity in relation to other facies described in the canyon. The presence of living cold-water reefs is directly related to a high-energy environment at depths between 700 and 1200 m in the levels between the lower bound of Eastern North Atlantic Central Water (ENACW) and the core of Mediterranean Water (MW). Such level matches the water density range ??=27.35-27.65 kg m-3 which has been identified as limits for cold-water coral distribution in the North Atlantic.

  5. An examination into the philosophy and literary expression of Don Ramo?n del Valle Incla?n

    E-print Network

    Shores, Belva Agnes

    1921-01-01

    of the requirements for the degree of Master of Arts. Approved by: Department of Hispanic Languages and Literatures. June 1, 1921. TABLE OP CONTENTS. Introduction. Chapter I Philosophy Sec. I El temple de las almas. Sec.II El dolor de vivir. Sec.III Amor y... dolor. Sec.IV Religion. Sec.V Politics. Chapter II Valle Inclín1s Literary Expression. Sec.I His Ideas on Literary Art. Sec.II Valle Inclan1s purpose. Sec.Ill Characteristics of Valle Inclán's Method. Chapter III Protagonists of Valle Inclan. Sec...

  6. Titanite petrochronology in the Fish Canyon Tuff

    NASA Astrophysics Data System (ADS)

    Schmitz, M. D.; Crowley, J. L.

    2014-12-01

    The petrologic complexity of the archtypical 'monotonous intermediate' Fish Canyon Tuff (FCT) has been previously established by a variety of mineralogical and geochemical proxies [1-2], and the unusual storage and eruptive dynamics of the FCT have been delineated by several geochronological studies [3-5]. Titanite is an apparent equilibrium phase in the penultimate FCT magma, and can be linked petrographically to hornblende crystals that preserve up-temperature core-to-rim zoning profiles. As a reactive, trace element-rich phase, we hypothesized that titanite may record an intracrystalline record of magma chamber dynamics. Titanite crystals from the same separate analyzed in [4] were oriented and doubly-polished to yield characteristic wedge-shaped cross-sectional wafers approximately 300 µm in thickness. BSE imaging guided LA-ICPMS analyses of a full suite of trace elements using a 25 µm beam diameter and crater depth on multiple locations across both sides of the wafer. Most titanite crystals are characterized by large variations in trace elements, including at least two generations of REE-enriched, actinide-poor, low Sr, large Eu anomaly cores overgrown by REE-depleted, actinide-rich, high Sr domains with small Eu anomalies and distinctive concave-up middle to heavy REE patterns. Trace element contents and patterns correlate strongly with Eu anomaly; intermediate compositions are abundant and spatially correlated to reaction zones between core and rim domains. Within the context of the batholithic rejuvenation model for the FCT magma [1-2], these trace element variations are interpreted to record the partial melting of a differentiated crystalline FCT precursor and its hybridization with a more 'mafic' flux. ID-TIMS dating of end-member titanites confirm older ages (ca 28.4 to 29.0 Ma) for cores and define a younger age for rejuvenation of ca 28.2 Ma, consistent with recent U-Pb zircon and 40Ar/39Ar studies [5-7]. [1] Bachmann & Dungan (2002) Am Mineral 87, 1062-1076. [2] Bachmann et al (2002) J Petrology 43, 1469-1503. [3] Bachmann et al (2007) Chem Geol 236, 134-166. [4] Schmitz & Bowring (2001) GCA 65, 2571-2587. [5] Wotzlaw et al (2013) Geology 41, 867-870. [6] Rivera et al. (2011) EPSL 311, 420-426. [7] Kuiper et al (2008) Science 320, 500-504.

  7. Water fluxes at an ocean margin in the presence of a submarine canyon

    NASA Astrophysics Data System (ADS)

    Skliris, N.; Hecq, J. H.; Djenidi, S.

    2002-04-01

    A 3-D, unsteady, nonlinear, high-resolution model is used to estimate shelf/slope exchanges through Calvi Canyon (NW Corsica, Mediterranean Sea) in various regimes of stratification and wind patterns. To evaluate the alongshore and cross-shore fluxes within the canyon area as well as the water exchanges between the canyon and Calvi Bay, volume transports are computed at the sides of two closed, interconnected boxes encompassing the canyon on the shelf and slope domains. Model results show that water transports between Calvi Bay and the open sea are determined by flow modifications in the canyon area. The mean horizontal flow deviates southwestward upstream of the canyon, generating an onshore transport in the western part of Calvi Bay. Within the canyon, the circulation is cyclonic and is responsible for an offshore transport downstream of the canyon and in the eastern part of the bay. The effect of stratification is shown to limit the vertical extent of the influence of canyon topography so that the alongshore flow above the canyon is quasi-undisturbed in strong stratified conditions, resulting in weak cross-shore exchange. Wind events are shown to be responsible for a strong increase of cross-shore transports between the bay and the canyon area.

  8. Submarine canyon and slope processes of the U.S. Atlantic continental margin

    USGS Publications Warehouse

    McGregor, B.A.

    1983-01-01

    Two regions on the U.S. Atlantic continental margin were surveyed using single-channel, seismic-reflection profiling techniques: the Mid-Atlantic Continental Slope and Rise seaward of New Jersey in the vicinity of Baltimore Canyon and the Continental Slope and upper Rise just north of Cape Hatteras. Submarine canyons are the dominant morphologic feature in both areas. The Continental Slope in the Baltimore Canyon area has a general sea-floor gradient of 3?-4? and a width of approximately 40 km, whereas the study area north of Cape Hatteras has a general sea-floor gradient of approximately 9? and a width of 20 km. The dominant slope process differs in each area. In the Baltimore Canyon area, subbottom reflectors suggest that sediment deposition with progradation of the slope is related to canyon processes. In the study area north of Cape Hatteras, the canyons appear erosional and mass wasting is the dominant erosional process. Dominant slope processes appear to be correlated with the width and sea-floor gradient of the Continental Slope. Although the absolute age of the canyons is difficult to determine without rotary-drill cores for stratigraphic control, Baltimore Canyon is suggested to be older than the shelf-indenting canyon just north of Cape Hatteras. An anomalously large ridge flanking Baltimore Canyon on the upper rise appears to be related to canyon depositional and erosional processes.

  9. A mineralized zone in Western Candor Chasma, Mars

    NASA Technical Reports Server (NTRS)

    Geissler, P. E.; Singer, R. B.; Komatsu, G.

    1993-01-01

    Spectral evidence from Viking and Phobos orbiting spacecraft suggests the local development of crystalline ferric oxides in a small region within Mars' equatorial Valles Marineris canyon system. This is the same area noted for its anomalous coloration in Viking Orbiter image 583 A by McEwen. The unique hue of the region in Viking color data is due to a reduced green filter reflectance, relative to violet and red, in comparison to surrounding materials of similar albedo or average reflectance. For this reason, the region does not appear spectrally distinctive in later Survey Mission images which were acquired without the green filter. In high resolution, the spectral unit can be seen to correspond to two 20 km long depressions on the margins of Candor Mensa, a heavily eroded plateau-forming deposit on the canyon floor. Laminae are conspicuous in several places on the plateau, particularly where 15 to 20 cycles of alternating bright and dark laminae are exposed at approximately 200 meter vertical intervals. Laminae are also visible on the steep, vertically fluted cliffs to the south of this depression. Concentric laminae indicate a basis in the depression on the southeastern margin of Candor Mensa at the location of the less pronounced hue anomaly. A distinct lineation at the base of the scarp at the western end of the canyon transects mottled canyon floor deposits believed to be among the youngest in the Valles marineris. Water is implicated in the formation of the iron oxides, since the steep surfaces of layered sediments elsewhere on Candor Mensa show no evidence of unusual coloration despite the fact that these materials were deposited concurrently with the strata exposed in the depressions. This suggests that the mineralization is secondary in nature and developed locally in association with the depressions, which could have ponded surface runoff or groundwater seepage.

  10. Anomalous topography on the continental shelf around Hudson Canyon

    USGS Publications Warehouse

    Knebel, H. J.

    1979-01-01

    Recent seismic-reflection data show that the topography on the Continental Shelf around Hudson Canyon is composed of a series of depressions having variable spacings (< 100 m to 2 km), depths (1-10 m), outlines, and bottom configurations that give the sea floor an anomalous "jagged" appearance in profile. The acoustic and sedimentary characteristics, the proximity to relict shores, and the areal distribution indicate that this rough topography is an erosional surface formed on Upper Pleistocene silty sands about 13,000 to 15,000 years ago by processes related to Hudson Canyon. The pronounced southward extension of the surface, in particular, may reflect a former increase in the longshore-current erosion capacity caused by the loss of sediments over the canyon. Modern erosion or nondeposition of sediments has prevented the ubiquitous sand sheet on the Middle Atlantic shelf from covering the surface. The "anomalous" topography may, in fact, be characteristic of areas near other submarine canyons that interrupt or have interrupted the longshore drift of sediments. ?? 1979.

  11. Grand Canyon Investigations: 131 years in the field

    USGS Multimedia Gallery

    Staff at the USGS Central Region Library created two displays for an open-house in celebration of National Library Week, April, 2010. This display on USGS scientific investigtations of the Grand Canyon displays field records, historical photography,historical surveying equipment, and publications fr...

  12. Grand Canyon Investigations: 131 Years in the Field

    USGS Multimedia Gallery

    Staff at the USGS Central Region Library created two displays for an open-house in celebration of National Library Week, April, 2010. This display on USGS scientific investigtations of the Grand Canyon displays field records, historical photography,historical surveying equipment, and publications fr...

  13. Photocatalytic abatement results from a model street canyon.

    PubMed

    Gallus, M; Ciuraru, R; Mothes, F; Akylas, V; Barmpas, F; Beeldens, A; Bernard, F; Boonen, E; Boréave, A; Cazaunau, M; Charbonnel, N; Chen, H; Daële, V; Dupart, Y; Gaimoz, C; Grosselin, B; Herrmann, H; Ifang, S; Kurtenbach, R; Maille, M; Marjanovic, I; Michoud, V; Mellouki, A; Miet, K; Moussiopoulos, N; Poulain, L; Zapf, P; George, C; Doussin, J F; Kleffmann, J

    2015-11-01

    During the European Life+ project PhotoPAQ (Demonstration of Photocatalytic remediation Processes on Air Quality), photocatalytic remediation of nitrogen oxides (NOx), ozone (O3), volatile organic compounds (VOCs), and airborne particles on photocatalytic cementitious coating materials was studied in an artificial street canyon setup by comparing with a colocated nonactive reference canyon of the same dimension (5?×?5?×?53 m). Although the photocatalytic material showed reasonably high activity in laboratory studies, no significant reduction of NOx, O3, and VOCs and no impact on particle mass, size distribution, and chemical composition were observed in the field campaign. When comparing nighttime and daytime correlation plots of the two canyons, an average upper limit NOx remediation of ?2 % was derived. This result is consistent only with three recent field studies on photocatalytic NOx remediation in the urban atmosphere, whereas much higher reductions were obtained in most other field investigations. Reasons for the controversial results are discussed, and a more consistent picture of the quantitative remediation is obtained after extrapolation of the results from the various field campaigns to realistic main urban street canyon conditions. PMID:26178827

  14. Thirty-five years at Pajarito Canyon Site

    SciTech Connect

    Paxton, H.C.

    1981-05-01

    A history of the research activities performed at the Pajarito Canyon Site from 1946 to 1981 is presented. Critical assemblies described include: the Topsy assembly; Lady Godiva; Godiva 2; Jezebel; Flattop; the Honeycomb assembly for Rover studies; Kiwi-TNT; PARKA reactor; Big Ten; and Plasma Cavity Assembly.

  15. CLARK CANYON (MONO COUNTY) RIPARIAN DEMONSTRATION AREA1

    E-print Network

    different treatments to restore riparian meadow ar- eas and to stabilize active erosion and gully develop to high levels of productivity, (2) stabilize active ero- sion and gully development (headcutting), (3 (BLM) established the Clark Canyon erosion control project. This project implemented sev- eral

  16. HELL'S CANYON STUDY, IDAHO AND NEZ PERCE COUNTIES, IDAHO, 1977

    EPA Science Inventory

    In September of 1975 and again in March and June of 1976, water quality survey runs were made in Hells Canyon (17060103, 17060101) to obtain information on the Snake River and its major tributaries within the area. The surveys included 5 Snake River stations from above Johnson B...

  17. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Park. The National Park Service reserves the right to limit the number of such permits issued, or the... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Grand Canyon National Park. 7.4 Section 7.4 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...

  18. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Park. The National Park Service reserves the right to limit the number of such permits issued, or the... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Grand Canyon National Park. 7.4 Section 7.4 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE...

  19. Grand Canyon Trekkers: School-Based Lunchtime Walking Program

    ERIC Educational Resources Information Center

    Hawthorne, Alisa; Shaibi, Gabriel; Gance-Cleveland, Bonnie; McFall, Sarah

    2011-01-01

    The incidence of childhood overweight is especially troubling among low income Latino youth. Grand Canyon Trekkers (GCT) was implemented as a quasi-experimental study in 10 Title 1 elementary schools with a large Latino population to examine the effects of a 16-week structured walking program on components of health-related physical fitness: Body…

  20. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Grand Canyon National Park. 7.4 Section 7.4 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR...SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.4 Grand...

  1. Carbonaceous aerosol particles from common vegetation in the Grand Canyon

    SciTech Connect

    Hallock, K.A.; Mazurek, M.A. ); Cass, G.R. . Dept. of Environmental Engineering Science)

    1992-05-01

    The problem of visibility reduction in the Grand Canyon due to fine organic aerosol particles in the atmosphere has become an area of increased environmental concern. Aerosol particles can be derived from many emission sources. In this report, we focus on identifying organic aerosols derived from common vegetation in the Grand Canyon. These aerosols are expected to be significant contributors to the total atmospheric organic aerosol content. Aerosol samples from living vegetation were collected by resuspension of surface wax and resin components liberated from the leaves of vegetation common to areas of the Grand Canyon. The samples were analyzed using high-resolution gas chromatography/mass spectrometry (GC/MS). Probable identification of compounds was made by comparison of sample spectra with National Institute of Standards and Technology (NIST) mass spectral references and positive identification of compounds was made when possible by comparison with authentic standards as well as NIST references. Using these references, we have been able to positively identify the presence of n-alkane and n-alkanoic acid homolog series in the surface waxes of the vegetation sampled. Several monoterpenes, sesquiterpenes, and diterpenes were identified also as possible biogenic aerosols which may contribute to the total organic aerosol abundance leading to visibility reduction in the Grand Canyon.

  2. Crisscrossing "Grand Canyon": Bridging the Gaps with Computer Conferencing.

    ERIC Educational Resources Information Center

    Minock, Mary; Shor, Francis

    1995-01-01

    Notes that Interdisciplinary Studies Program faculty at Wayne State University devised courses and assignments using computer conferencing to create a collaborative, democratic, and nonauthoritarian learning community. Discusses an assignment based on the film "Grand Canyon" that encouraged students to take on roles of their racial and gender…

  3. National Uranium Resource Evaluation, Grand Canyon Quadrangle, Arizona

    SciTech Connect

    Baillieul, T.A.; Zollinger, R.C.

    1982-06-01

    The Grand Canyon Quadrangle (2/sup 0/), northwestern Arizona, was evaluated to identify environments and delineate areas favorable for the occurrence of uranium deposits. This was done using criteria developed for the National Uranium Resource Evaluation. General surface reconnaissance and geochemical sampling were carried out in all geologic environments within the quadrangle. Aerial radiometric and hydrochemical and stream-sediment reconnaissance surveys were performed, although results were not available in time for field checking. The results of this investigation indicate environments favorable for: channel-controlled, peneconcordant sandstone deposits in the Petrified Forest Member of the Chinle Formation in the north-central part of the quadrangle, vein-type deposits in collapse breccias in all areas underlain by the Redwall Limestone, and unconformity-related deposits in the metasediments of the Vishnu Group within the Grand Canyon. All other rock units examined are considered unfavorable for hosting uranium deposits. Younger Precambrian rocks of the Grand Canyon Supergroup, exposed only within the Grand Canyon National Park, remain unevaluated.

  4. 9. COULTERVILLE ROAD VIEW AND MERCED RIVER CANYON. NOTE CUT ...

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

    9. COULTERVILLE ROAD VIEW AND MERCED RIVER CANYON. NOTE CUT FACE OF STANDING ROCK AT RIGHT. LOOKING N. GIS: N-37 42 52.1 / W-119 43 17.5 - Coulterville Road, Between Foresta & All-Weather Highway, Yosemite Village, Mariposa County, CA

  5. Predicting velocities and turbulent momentum exchange in isolated street canyons

    NASA Astrophysics Data System (ADS)

    Hall, Terianne C.; Britter, Rex E.; Norford, Leslie K.

    2012-11-01

    A simplified way of studying the transport of mass and momentum through dense neighborhoods is to consider the flow field as a combination of a mainly horizontal flow along street canyons and a vertical flow into and out of street canyons. In this paper, we derive a simple, semi-analytical model for calculating the expected wind speeds in narrow, isolated, idealized street canyons of uniform height that are aligned with and at an angle to the wind through the introduction of a non-dimensional parameterization of the vertical turbulent exchange of horizontal momentum between the urban canopy layer (UCL) and the urban boundary layer (UBL). The model is closed and evaluated using computational fluid dynamics (CFD) in a generic way. The RMSE of the normalized bulk velocity in the street canyon in the direction of the freestream flow is 1.8 × 10-4, 2.3 × 10-2 and 9.4 × 10-2 for variations in façade roughness, aspect ratio and canyon orientation, respectively. We argue that there is a need for a fast, simple methodology to assess the impact of urban form on neighborhood microclimate, especially in dense neighborhoods, and specifically for use in the early phases of design. This methodology should be able to predict areas in a neighborhood that are prone to low wind speeds or weak mass and momentum exchange rates with the UBL above because these areas may be particularly susceptible to pollutant retention and the urban heat island (UHI) effect. Current methodologies are often inadequate for this purpose because they use computationally intensive techniques to solve for flow through a neighborhood and often require a strong technical background to support their use. The work in this paper addresses this problem for an idealized, narrow street canyon, and we discuss the need for parameterizations for urban form that are relevant to mass and momentum exchange rates to extend this model beyond a single street canyon. Finally, we discuss how this work could be further developed into generalized planning guidelines and incorporated into a comprehensive urban planning methodology that aims to passively mitigate the UHI effect and pollutant retention through the clever design of urban form.

  6. Small Mammal Sampling in Mortandad and Los Alamos Canyons, 2005

    SciTech Connect

    Bennett, Kathy; Sherwood, Sherri; Robinson, Rhonda

    2006-08-15

    As part of an ongoing ecological field investigation at Los Alamos National Laboratory, a study was conducted that compared measured contaminant concentrations in sediment to population parameters for small mammals in the Mortandad Canyon watershed. Mortandad Canyon and its tributary canyons have received contaminants from multiple solid waste management units and areas of concern since establishment of the Laboratory in the 1940s. The study included three reaches within Effluent and Mortandad canyons (E-1W, M-2W, and M-3) that had a spread in the concentrations of metals and radionuclides and included locations where polychlorinated biphenyls and perchlorate had been detected. A reference location, reach LA-BKG in upper Los Alamos Canyon, was also included in the study for comparison purposes. A small mammal study was initiated to assess whether potential adverse effects were evident in Mortandad Canyon due to the presence of contaminants, designated as contaminants of potential ecological concern, in the terrestrial media. Study sites, including the reference site, were sampled in late July/early August. Species diversity and the mean daily capture rate were the highest for E-1W reach and the lowest for the reference site. Species composition among the three reaches in Mortandad was similar with very little overlap with the reference canyon. Differences in species composition and diversity were most likely due to differences in habitat. Sex ratios, body weights, and reproductive status of small mammals were also evaluated. However, small sample sizes of some species within some sites affected the analysis. Ratios of males to females by species of each site (n = 5) were tested using a Chi-square analysis. No differences were detected. Where there was sufficient sample size, body weights of adult small mammals were compared between sites. No differences in body weights were found. Reproductive status of species appears to be similar across sites. However, sample size prevents a detailed examination of reproduction composition. Because of small sample size of some species and differences that might occur on a seasonal basis, additional sampling would need to be conducted to further evaluate sex ratios, body weights, and reproductive characteristics.

  7. Thermal bioclimate in idealized urban street canyons in Campinas, Brazil

    NASA Astrophysics Data System (ADS)

    Abreu-Harbich, Loyde V.; Labaki, Lucila C.; Matzarakis, Andreas

    2014-01-01

    Among several urban design parameters, the height-to-width ratio (H/W) and orientation are important parameters strongly affecting thermal conditions in cities. This paper quantifies changes in thermal comfort due to typical urban canyon configurations in Campinas, Brazil, and presents urban guidelines concerning H/W ratios and green spaces to adapt urban climate change. The study focuses on thermal comfort issues of humans in urban areas and performs evaluation in terms of physiologically equivalent temperature (PET), based on long-term data. Meteorological data of air temperature, relative humidity, wind speed and solar radiation over a 7-year period (2003-2010) were used. A 3D street canyon model was designed with RayMan Pro software to simulate the influence of urban configuration on urban thermal climate. The following configurations and setups were used. The model canyon was 500 m in length, with widths 9, 21, and 44 m. Its height varied in steps of 2.5 m, from 5 to 40 m. The canyon could be rotated in steps of 15°. The results show that urban design parameters such as width, height, and orientation modify thermal conditions within street canyons. A northeast-southwest orientation can reduce PET during daytime more than other scenarios. Forestry management and green areas are recommended to promote shade on pedestrian areas and on façades, and to improve bioclimate thermal stress, in particular for H/W ratio less than 0.5. The method and results can be applied by architects and urban planners interested in developing responsive guidelines for urban climate issues.

  8. Cosmogenic 3He ages and frequency of late Holocene debris flows from Prospect Canyon, Grand Canyon, USA

    USGS Publications Warehouse

    Cerling, T.E.; Webb, R.H.; Poreda, R.J.; Rigby, A.D.; Melis, T.S.

    1999-01-01

    Lava Falls Rapid, which was created and is maintained by debris flows from Prospect Canyon, is the most formidable reach of whitewater on the Colorado River in Grand Canyon and is one of the most famous rapids in the world. Debris flows enter the Colorado River at tributary junctures, creating rapids. The frequency of debris flows is an important consideration when management of regulated rivers involves maintenance of channel morphology. We used cosmogenic 3He, 14C, and historical photographs to date 12 late Holocene and historic debris flows from Prospect Canyon. The highest and oldest deposits from debris flows on the debris fan yielded a 3He date of about 3 ka, which indicates predominately late Holocene aggradation of one of the largest debris fans in Grand Canyon. The deposit, which has a 25-m escarpment caused by river reworking, crossed the Colorado River and raised its base level by 30 m for an indeterminate although likely short period. We mapped depositional surfaces of 11 debris flows that occurred after 3 ka. Two deposits inset against the highest deposit yielded 3He ages of about 2.2 ka, and at least two others followed shortly afterwards. At least one of these debris flows also dammed the Colorado River. The most recent prehistoric debris flow occurred no more than 0.5 ka. The largest historic debris flow, which constricted the river by 80%, occurred in 1939. Five other debris flows occurred after 1939; these debris flows constricted the Colorado River by 35-80%. Assuming the depositional volumes of late Holocene debris flows can be modeled using a lognormal distribution, we calculated recurrence intervals of 15 to more than 2000 years for debris flows from Prospect Canyon.

  9. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    SciTech Connect

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative.

  10. Depositional framework and genesis of Wilcox Submarine Canyon systems, Northwest Gulf Coast

    SciTech Connect

    Galloway, W.F.; Dinqus, W.F.; Paige, R.E.

    1988-01-01

    Wilcox (late Paleocene-early Eocene) slope systems of the Texas coastal plain contain two families of paleosubmarine canyons that exhibit distinctly different characteristics and stratigraphic settings: Yoakum and Lavaca type canyons occur as widely separated features within the generally retrogradational middle Wilcox interval. Four such canyons exhibit high length to width ratios, extend far updip of the contemporaneous shelf edge, were excavated deeply into paralic and coastal-plain deposits, and were filled primarily by mud. Fills consist of a lower onlapping unit and capping progradational deposits that are genetically related to deposition of the upper Wilcox fluvial-deltaic sequence. Significantly, the canyon fills correlate with widespread transgressive marine mudstones (the Yoakum shale-Sabinetown Formation and ''Big Shale''). In contrast, Lavaca-type canyons form a system of erosional features created along the rapidly prograding, unstable lower Wilcox continental margin. Comparative analysis of the two canyon system suggests a general process model for submarine canyon formation on prograding basin margins. Key elements are depositional loading of the continental margin creating instability, initiation of a large-scale slump, family of slumps, or listric bedding-plane fault creating a depression or indentation in the margin, and headward and lateral expansion of the depression by slumping and density-underflow erosion. Extent of canyon evolution varies according to time and submerged space available for maturation; short, broad canyons form on narrow shelves of actively prograding margins, and elongate mature canyons form in retrogradational or transgressive settings.

  11. Headless submarine canyons and fluid flow on the toe of the Cascadia accretionary complex

    USGS Publications Warehouse

    Orange, D.L.; McAdoo, B.G.; Moore, J.C.; Tobin, H.; Screaton, E.; Chezar, H.; Lee, H.; Reid, M.; Vail, R.

    1997-01-01

    Headless submarine canyons with steep headwalls and shallowly sloping floors occur on both the second and third landward vergent anticlines on the toe of the Cascadia accretionary complex off central Oregon (45 ??N, 125?? 30??W). In September 1993, we carried out a series of nine deep tow camera sled runs and nine ALVIN dives to examine the relationship between fluid venting, structure and canyon formation. We studied four canyons on the second and third landward vergent anticlines, as well as the apparently unfailed intercanyon regions along strike. All evidence of fluid expulsion is associated with the canyons; we found no evidence of fluid flow between canyons. Even though all fluid seeps are related to canyons, we did not find seeps in all canyons, and the location of the seeps within the canyons differed. On the landward facing limb of the second landward vergent anticline a robust cold seep community occurs at the canyon's inflection point. This seep is characterized by chemosynthetic vent clams, tube worms and extensive authigenic carbonate. Fluids for this seep may utilize high-permeability flow paths either parallel to bedding within the second thrust ridge or along the underlying thrust fault before leaking into the overriding section. Two seaward facing canyons on the third anticlinal ridge have vent clam communities near the canyon mouths at approximately the intersection between the anticlinal ridge and the adjacent forearc basin. No seeps were found along strike at the intersection of the slope basin and anticlinal ridge. We infer that the lack of seepage along strike and the presence of seeps in canyons may be related to fluid flow below the forearc basin/slope unconformity (overpressured by the impinging thrust fault to the west?) directed toward canyons at the surface.

  12. Isotopic and geochemical constraints on the origin and evolution of postcollapse rhyolites in the Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Spell, Terry L.; Kyle, Philip R.; Thirlwall, Matthew F.; Campbell, Andrew R.

    1993-11-01

    Ring-fracture rhyolites of the Valles Caldera (VC) were examined to determine the evolution of the magma system following eruption of the upper Bandelier Tuff (UBT) and subsequent caldera collapse. Volcanism began with eruption of Deer Canyon (DC), Redondo Creek, and Del Medio (DM) rhyolites during the interval 1140-1133 ka. Quartz delta O-18 for the UBT, (average +8.3 %), DC (+7.9 %), and DM (+8.7 %) rhyolites indicate no significant lowering of delta O-18 following caldera collapse. In contrast, DM rhyolites record low epsilon(sub Nd) of -3.6 to -3.8 relative to the UBT (-2.7) and variable initial 87-Sr/86-Sr (0.70923-0.71307). Del Abrigo (DA) and Santa Rosa I rhyolites (973-915 ka) exhibit lower epsilon(Sub Nd) (-4.4 to -4.6) and initial 87-Sr/86-Sr (0.70707-0.71009), as well as shifts in compatible and incompatible trace element ratios. Seco, San Luis, and Santa Rosa II rhyolites (800-787 ka) have epsilon(Sub Nd) (-4.0 to -4.3) similar to the 973 to 915 ka rhyolites but lower initial 87-Sr/86-Sr (0.70616-0.70747). After a hiatus of 230 ka, San Antonio (SA), South Mountain (SM), and La Jara (LJ) rhyolites (557-521 ka) were erupted with epsilon(Sub Nd) of -3.7 to 4.3, distinctly lower initial 87-Sr/86-Sr of 0.70513-0.70553 and less evolved trace element compositions. The youngest rhyolites, the El Cajete-Banco Bonito group (EC-BB) (300-170 ka) are petrographically and geochemically distinct with the highest epsilon(Sub Nd) (-2.7 to -3.0) and the lowest initial 87-Sr/86-Sr (0.70464-0.70478) of postcollapse rhyolites. The isotopic data indicate that Valles rhyolites are not direct melts of Proterozoic basement (epsilon(Sub Nd) of -10 to -15) and indicate a significant mantle-derived (basaltic) component. Elevated initial 87-Sr/86-Sr is restricted to rhyolites depleted in Sr (less than 10 ppm) and probably reflects minor upper crustal assimilation. Calculated magma delta 0-18 values (+6.6 to +7.0 %) indicate no substantial supracrustal sediment in the source region, nor interaction with hydrothermal fluids (or altered wall rock) in the upper crust. The intermittent volcanic activity and the heterogeneity of petrographic, geochemical, and isotopic compositions from one eruptive interval to the next suggests that these rhyolites were vented from a series of temporally and spatially separated magma chambers. Parental melts supplied to these magma chambers were most probably produced by basalt-induced fusion events in a hybridized deep crustal environment.

  13. Variation of Fracturing Pressures with Depth Near the Valles Caldera

    SciTech Connect

    Dash, Zora; Murphy, Hugh

    1983-12-15

    Hydraulic Fracturing at the Fenton Hill Hot Dry Rock Geothermal site near the Valles Caldera has yielded fracturing pressures from 14 to 81 MPa (2030 to 11,750 psi) at depths ranging from 0.7 to 4.4 km (2250 to 14,400 ft). This data can be fit to a fracture gradient of 19 MPa/km (0.84 psi/ft), except for an anomalous region between 2.6 to 3.2 km where fracturing pressures are about 20 MPa lower than estiamted using the above gradient. This anomaly coincides with a biotite granodiorite intrusive emplaced into a heterogeneous jointed metamorphic complex comprised of gneisses, schists and metavolcanic rocks. Microseismic events detected with sensitive downhole geophones suggest that shear failure is an important process during hydraulic fracturing of such jointed rock. Consequently the usual relation between minimum earth stress and fracture opening pressure, based upon classic tensile failure, cannot be used apriori; fracture opening pressure is instead a complex function of joint orientation and all three components of principal earth stress.

  14. Scientific core hole VC-2A, Valles Caldera, New Mexico

    SciTech Connect

    Musgrave, J.; Goff, S. ); Turner, T. , Salt Lake City, UT )

    1990-10-01

    This report details the remedial action activities that were necessary to complete scientific core hole Valles caldera {number sign}2A (VC-2A) before it was relinquished to the landowners. Sandia National Laboratories, acting as the Geoscience Research Drilling Office (GRDO), managed the coring operations. Los Alamos National Laboratory (Los Alamos) obtained the proper drilling permits with the New Mexico State Engineers Office (SEO). A legal agreement between Los Alamos and the landowners states that the Laboratory will give the landowners the completed core hold with casing, well head, and other hardware at the end of May 1991, or earlier if scientific investigations were completed. By May 1988, the Science Team completed the planned scientific investigations in the VC-2A core hole. Upon the insistence of the GRDO, the New Mexico Oil Conservation Division (OCD) inspected the core hole, declared jurisdiction, and required that the 11.43- by 11.43-cm annular cement job be repaired to comply with OCD regulations. These regulations state that there must be a return to surface of cement in all cementing operations. We successfully completed a squeeze cementing operation and relinquished the core hold to the landowners in November 1988 to the satisfaction of the OCD, SEO, the landowners, and Los Alamos. 7 refs., 4 figs., 1 tab.

  15. Restoring Anadromous Fish Habitat in Big Canyon Creek Watershed; Anadromous Fish Habitat Restoration in the Nichols Canyon Subwatershed, 1999 Annual Report.

    SciTech Connect

    Koziol, Deb

    2000-02-01

    Nez Perce Soil & Water Conservation District (NPSWCD) undertook the Nichols Canyon Subwatershed Steelhead Trout Habitat Improvement Project in the spring of 1999. This Project is funded through a grant provided by the Bonneville Power Administration. The Project's purpose is to install and implement agricultural best management practices (BMPs) and riparian restorations to improve steelhead trout spawning and rearing habitat in the Nichols Canyon subwatershed of Big Canyon Creek. Improvements to spawning and rearing habitat in lower Big Canyon Creek tributaries will enhance natural production of the species in Big Canyon Creek and ultimately the Clearwater River. The following report is a summation of the activities undertaken by the NPSWCD in the first year of the project.

  16. Morphology, structures and seismic characters of the Chimei Canyon-Fan system offshore eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Hsieh, Y. H.; Liu, C. S.

    2014-12-01

    The Chimei submarine canyon located offshore east Taiwan shows a very distinct morphology, it has a wide (9 km in average) and very smooth bottom, a submarine fan was formed at its foot but the northern part of the submarine fan has been washed away. This canyon starts from the Hsiukuluan River estuary, runs eastward across the eastern flank of the Luzon arc, and merges into the Hualien Canyon near the western end of the Ryukyu Trench off NE Taiwan. The Chimei canyon can be divided into two parts: the upper section is a U-shaped canyon with broad and flat bottom and high walls; the lower section meanders across a deep sea fan in the Huatung basin. In this study, we use multichannel seismic reflection profile data together with high resolution bathymetry data to study the topography, basement structures and seismic sequences along the canyon path and in the distal fan. The U-shaped upper Chimei canyon seems to be carved not only by submarine erosion but also by structural uplift of both side-walls. The canyon walls are up to 950 m above the canyon floor, strata truncations along both sides of the canyon walls and many slumps are observed. The upper Chimei canyon was developed along basement lows of the highly deformed Luzon arc, and runs across a series of N-S trending thrusts. Acoustic basement and lower strata are deformed and folded, and young sediments cover the canyon floor smoothly. We find many thrusts run across the upper Chimei canyon, but now the canyon bottom is smooth. The concave thalweg profile seems to reach the equilibrium between erosion and deposition. An east-vergent thrust fault lies at the foot of the eastern flank of the Luzon arc which separates the upper section from the lower section of the Chimei Canyon. The lower section of the Chimei canyon flows over a submarine fan where eight seismic sequences are recognized. The two lower sequences show continuous, parallel to sub-parallel sheet-drape seismic facies which fill the basement low. They are interpreted to be old deep sea sediment. The six upper sequences show chaotic and mounded seismic facies, and also transparent and continuous parallel seismic strata. We interpret those are characters of submarine fan. Some large slumps occurred at northern half of the submarine fan. The northern half of the submarine fan has been eroded away already by canyon and slumps.

  17. Geomorphic characterization of four shelf-sourced submarine canyons along the U.S. Mid-Atlantic continental margin

    NASA Astrophysics Data System (ADS)

    Obelcz, Jeffrey; Brothers, Daniel; Chaytor, Jason; Brink, Uri ten; Ross, Steve W.; Brooke, Sandra

    2014-06-01

    Shelf-sourced submarine canyons are common features of continental margins and are fundamental to deep-sea sedimentary systems. Despite their geomorphic and geologic significance, relatively few passive margin shelf-breaching canyons worldwide have been mapped using modern geophysical methods. Between 2007 and 2012 a series of geophysical surveys was conducted across four major canyons of the US Mid-Atlantic margin: Wilmington, Baltimore, Washington, and Norfolk canyons. More than 5700 km2 of high-resolution multibeam bathymetry and 890 line-km of sub-bottom CHIRP profiles were collected along the outer shelf and uppermost slope (depths of 80-1200 m). The data allowed us to compare and contrast the fine-scale morphology of each canyon system. The canyons have marked differences in the morphology and orientation of canyon heads, steepness and density of sidewall gullies, and the character of the continental shelf surrounding canyon rims. Down-canyon axial profiles for Washington, Baltimore and Wilmington canyons have linear shapes, and each canyon thalweg exhibits morphological evidence for recent, relatively small-scale sediment transport. For example, Washington Canyon displays extremely steep wall gradients and contains ~100 m wide, 5-10 m deep, v-shaped incisions down the canyon axis, suggesting modern or recent sediment transport. In contrast, the convex axial thalweg profile, the absence of thalweg incision, and evidence for sediment infilling at the canyon head, suggest that depositional processes strongly influence Norfolk Canyon during the current sea-level high-stand. The north walls of Wilmington, Washington and Norfolk canyons are steeper than the south walls due to differential erosion, though the underlying cause for this asymmetry is not clear. Furthermore, we speculate that most of the geomorphic features observed within the canyons (e.g., terraces, tributary canyons, gullies, and hanging valleys) were formed during the Pleistocene, and show only subtle modification by Holocene processes active during the present sea-level high-stand.

  18. Geomorphic characterization of four shelf-sourced submarine canyons along the U.S. Mid-Atlantic continental margin

    USGS Publications Warehouse

    Obelcz, Jeffrey; Brothers, Daniel S.; Chaytor, Jason D.; ten Brink, Uri S.; Ross, Steve W.; Brooke, Sandra

    2013-01-01

    Shelf-sourced submarine canyons are common features of continental margins and are fundamental to deep-sea sedimentary systems. Despite their geomorphic and geologic significance, relatively few passive margin shelf-breaching canyons worldwide have been mapped using modern geophysical methods. Between 2007 and 2012 a series of geophysical surveys was conducted across four major canyons of the US Mid-Atlantic margin: Wilmington, Baltimore, Washington, and Norfolk canyons. More than 5700 km2 of high-resolution multibeam bathymetry and 890 line-km of sub-bottom CHIRP profiles were collected along the outer shelf and uppermost slope (depths of 80-1200 m). The data allowed us to compare and contrast the fine-scale morphology of each canyon system. The canyons have marked differences in the morphology and orientation of canyon heads, steepness and density of sidewall gullies, and the character of the continental shelf surrounding canyon rims. Down-canyon axial profiles for Washington, Baltimore and Wilmington canyons have linear shapes, and each canyon thalweg exhibits morphological evidence for recent, relatively small-scale sediment transport. For example, Washington Canyon displays extremely steep wall gradients and contains ~100 m wide, 5–10 m deep, v-shaped incisions down the canyon axis, suggesting modern or recent sediment transport. In contrast, the convex axial thalweg profile, the absence of thalweg incision, and evidence for sediment infilling at the canyon head, suggest that depositional processes strongly influence Norfolk Canyon during the current sea-level high-stand. The north walls of Wilmington, Washington and Norfolk canyons are steeper than the south walls due to differential erosion, though the underlying cause for this asymmetry is not clear. Furthermore, we speculate that most of the geomorphic features observed within the canyons (e.g., terraces, tributary canyons, gullies, and hanging valleys) were formed during the Pleistocene, and show only subtle modification by Holocene processes active during the present sea-level high-stand.

  19. Basaltic Ring Structures as an Analog for Ring Features in Athabasca Valles, Mars

    NASA Technical Reports Server (NTRS)

    Jaeger, W. L.; Keszthelyi, L. P.; Burr, D. M.; Emery, J. P.; Baker, V. R.; McEwen, A. S.; Miyamoto, H.

    2005-01-01

    Basaltic ring structures (BRSs) are enigmatic, quasi-circular landforms in eastern Washington State that were first recognized in 1965. They remained a subject of geologic scrutiny through the 1970 s and subsequently faded from the spotlight, but recent Mars Orbiter Camera (MOC) images showing morphologically similar structures in Athabasca Valles, Mars, have sparked renewed interest in BRSs. The only known BRSs occur in the Channeled Scabland, a region where catastrophic Pleistocene floods from glacial Lake Missoula eroded into the Miocene flood basalts of the Columbia Plateau. The geologic setting of the martian ring structures (MRSs) is similar; Athabasca Valles is a young channel system that formed when catastrophic aqueous floods carved into a volcanic substrate. This study investigates the formation of terrestrial BRSs and examines the extent to which they are appropriate analogs for the MRSs in Athabasca Valles.

  20. Field trip guide to the Valles Caldera and its geothermal systems

    SciTech Connect

    Goff, F.E.; Bolivar, S.L.

    1983-12-01

    This field trip guide has been compiled from extensive field trips led at Los Alamos National Laboratory during the past six years. The original version of this guide was designed to augment a workshop on the Valles Caldera for the Continental Scientific Drilling Program (CSDP). This workshop was held at Los Alamos, New Mexico, 5-7 October 1982. More stops were added to this guide to display the volcanic and geothermal features at the Valles Caldera. The trip covers about 90 miles (one way) and takes two days to complete; however, those who wish to compress the trip into one day are advised to use the designated stops listed in the Introduction. Valles Caldera and vicinity comprise both one of the most exciting geothermal areas in the United States and one of the best preserved Quaternary caldera complexes in the world.

  1. Vegetation and substrate on aeolian landscapes in the Colorado River corridor, Cataract Canyon, Utah

    USGS Publications Warehouse

    Draut, Amy E.; Gillette, Elizabeth R.

    2010-01-01

    Vegetation and substrate data presented in this report characterize ground cover on aeolian landscapes of the Colorado River corridor through Cataract Canyon, Utah, in Canyonlands National Park. The 27-km-long Cataract Canyon reach has undergone less anthropogenic alteration than other reaches of the mainstem Colorado River. Characterizing ecosystem parameters there provides a basis against which to evaluate future changes, such as those that could result from the further spread of nonnative plant species or increased visitor use. Upstream dams have less effect on the hydrology and sediment supply in Cataract Canyon compared with downstream reaches in Grand Canyon National Park. For this reason, comparison of these vegetation and substrate measurements with similar data from aeolian landscapes of Grand Canyon will help to resolve the effects of Glen Canyon Dam operations on the Colorado River corridor ecosystem.

  2. Does littoral sand bypass the head of Mugu Submarine Canyon? - a modeling study

    USGS Publications Warehouse

    Xu, Jingping; Elias, Edwin; Kinsman, Nicole

    2011-01-01

    A newly developed sand-tracer code for the process-based model Delft3D (Deltares, The Netherlands) was used to simulate the littoral transport near the head of the Mugu Submarine Canyon in California, USA. For westerly swells, which account for more than 90% of the wave conditions in the region, the sand tracers in the downcoast littoral drift were unable to bypass the canyon head. A flow convergence near the upcoast rim of the canyon intercepts the tracers and moves them either offshore onto the shelf just west of the canyon rim (low wave height conditions) or into the canyon head (storm wave conditions). This finding supports the notion that Mugu Canyon is the true terminus of the Santa Barbara Littoral Cell.

  3. Influence of San Gabriel submarine canyon on narrow-shelf sediment dynamics, southern California

    USGS Publications Warehouse

    Karl, Herman A.

    1980-01-01

    A conceptual model attributes the PTC to modification of shelf circulation patterns by San Gabriel Canyon. Surface waves diverge over the canyon head resulting in differential wave set up at the shore face. This forces back turbid nearshore water for a distance of a few kilometers toward the canyon. At some point on the shelf, seaward nearshore flow overlaps offshore currents generated or modified by internal waves focused onto the shelf by the canyon and/or turbulent eddies produced by flow separation in currents moving across the canyon axis. At times, these subtle processes overprint tidal and wind-driven currents and thereby create the PTC. The model suggests that canyons heading several kilometers from shore can have a regulatory effect on narrow-shelf sediment dynamics.

  4. Apatite 4He/3He and (U-Th)/He evidence for an ancient Grand Canyon.

    PubMed

    Flowers, R M; Farley, K A

    2012-12-21

    The Grand Canyon is one of the most dramatic features on Earth, yet when and why it was carved have been controversial topics for more than 150 years. Here, we present apatite (4)He/(3)He thermochronometry data from the Grand Canyon basement that tightly constrain the near-surface cooling history associated with canyon incision. (4)He/(3)He spectra for eastern Grand Canyon apatites of differing He date, radiation damage, and U-Th zonation yield a self-consistent cooling history that substantially validates the He diffusion kinetic model applied here. Similar data for the western Grand Canyon provide evidence that it was excavated to within a few hundred meters of modern depths by ~70 million years ago (Ma), in contrast to the conventional model in which the entire canyon was carved since 5 to 6 Ma. PMID:23196906

  5. Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon

    NASA Astrophysics Data System (ADS)

    Flowers, R. M.; Farley, K. A.

    2012-12-01

    The Grand Canyon is one of the most dramatic features on Earth, yet when and why it was carved have been controversial topics for more than 150 years. Here, we present apatite 4He/3He thermochronometry data from the Grand Canyon basement that tightly constrain the near-surface cooling history associated with canyon incision. 4He/3He spectra for eastern Grand Canyon apatites of differing He date, radiation damage, and U-Th zonation yield a self-consistent cooling history that substantially validates the He diffusion kinetic model applied here. Similar data for the western Grand Canyon provide evidence that it was excavated to within a few hundred meters of modern depths by ~70 million years ago (Ma), in contrast to the conventional model in which the entire canyon was carved since 5 to 6 Ma.

  6. Internal tidal currents in the Gaoping (Kaoping) Submarine Canyon

    USGS Publications Warehouse

    Lee, I.-H.; Wang, Y.-H.; Liu, J.T.; Chuang, W.-S.; Xu, Jie

    2009-01-01

    Data from five separate field experiments during 2000-2006 were used to study the internal tidal flow patterns in the Gaoping (formerly spelled Kaoping) Submarine Canyon. The internal tides are large with maximum interface displacements of about 200??m and maximum velocities of over 100cm/s. They are characterized by a first-mode velocity and density structure with zero crossing at about 100??m depth. In the lower layer, the currents increase with increasing depth. The density interface and the along-channel velocity are approximately 90?? out-of-phase, suggesting a predominant standing wave pattern. However, partial reflection is indicated as there is a consistent phase advance between sea level and density interface along the canyon axis. ?? 2008 Elsevier B.V. All rights reserved.

  7. Canyon Creek: A late Pleistocene vertebrate locality in interior Alaska

    USGS Publications Warehouse

    Weber, F.R.; Hamilton, T.D.; Hopkins, D.M.; Repenning, C.A.; Haas, H.

    1981-01-01

    The Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene. Tanana River gravel at the base of the section evidently formed during the Delta Glaciation of the north-central Alaska Range. Younger layers and lenses of fluvial sand are interbedded with arkosic gravel from Canyon Creek that contains tephra as well as fossil bones of an interstadial fauna about 40,000 years old. Solifluction deposits containing ventifacts, wedge casts, and rodent burrows formed during a subsequent period of periglacial activity that took place during the maximum phase of Donnelly Glaciation about 25,000-17,000 years ago. Overlying sheets of eolian sand are separated by a 9500-year-old paleosol that may correlate with a phase of early Holocene spruce expansion through central Alaska. The Pleistocene fauna from Canyon Creek consists of rodents (indicated by burrows), Mammuthus primigenius (woolly mammoth), Equus lambei (Yukon wild ass), Camelops hesternus (western camel), Bison sp. cf. B. crassicornis (large-horned bison), Ovis sp. cf. O. dalli (mountain sheep), Canis sp. cf. C. lupus (wolf), Lepus sp. cf. L. othus or L. arcticus (tundra hare), and Rangifer sp. (caribou). This assemblage suggests an open landscape in which trees and tall shrubs were either absent or confined to sheltered and moist sites. Camelops evidently was present in eastern Beringia during the middle Wisconsin interstadial interval but may have disappeared during the following glacial episode. The stratigraphic section at Canyon Creek appears to demonstrate that the Delta Glaciation of the north-central Alaska Range is at least in part of early Wisconsin age and was separated from the succeeding Donnelly Glaciation by an interstadial rather than interglacial episode. ?? 1981.

  8. Landslides and debris flows in Ephraim Canyon, central Utah

    SciTech Connect

    Baum, R.L.; Fleming, R.W.

    1989-01-01

    The geology of 36 km{sup 2} in Ephraim Canyon, on the west side of the Wasatch Plateau, central Utah, was mapped at a scale of 1:12,000 following the occurrence of numerous landslides in 1983. The geologic map shows the distribution of the landslides and debris flows of 1983-86, as well as older landslide deposits, other surficial deposits, and bedrock. Several of the recent landslides are described and illustrated by means of maps or photographs.

  9. Green Canyon wells require well-engineered drilling programs

    SciTech Connect

    Corley, J.; Vice, C.; McCary, T.; Decker, B.

    1986-01-01

    Drilling in the Green Canyon area poses technical and operational challenges for operators and the oil field service industry. Amerada Hess Inc.'s success in carrying out a two-well exploratory program in Green Canyon's Block 66 was due to a well-coordinated team effort, carefully designed drilling plan, and prudent operating procedures. The Green Canyon area is located 75 miles offshore, southwest of New Orleans, La., at the edge of the continental shelf. Research of offset wells in May 1984 provided numerous factors to consider for a safe and economical completion of the two-well drilling program, including: Logistics; Water depth of approximately 1,200 ft; Operational cost - the cost for a drillship or semisubmersible and auxiliary equipment and supplies can run $80,000 day; Formation pressures which require high mud weights at shallow depths; Low fracture gradients in deep water; Gumbo shale formations which are susceptible to hydration and dispersion. Further, operating personnel were concerned with several potential downhole problems that could be caused by the gumbo shale formations: Well bore instability; Hole cleaning, hole pack-off, plugged flow lines, and lost circulation; Gumbo balling on the bit and drill string; Excessive torque and drag; Excessive swab and surge pressures; Stuck pipe; Inadequate directional control; Improper solids control. In the Green Canyon area, with a high daily cost of operating, economics are greatly influenced by time spent on location. Therefore, once the well is designed, emphasis must be placed on a drilling fluid to 18,000 ft. The first well was deviated at 3,800 ft to a maximum of 39/sup 0/ angle, which was maintained to 9,900 ft and dropped to vertical. The curved sections of hole were cased quickly. In addition, control was enhanced by reduced balling on the bottomhole assembly and a gauge hole.

  10. LITTLE DOG AND PUP CANYONS ROADLESS AREA, NEW MEXICO.

    USGS Publications Warehouse

    Hayes, Philip T.; Bigsby, Philip R.

    1984-01-01

    The Little Dog and Pup Canyons Roadless Area comprises about 41 sq mi along the precipitous west escarpment of the Guadalupe Mountains in southeastern New Mexico. On the basis of a mineral survey area is considered to have a portable potential for oil and (or) gas resources and little likelihood for the occurrence of other mineral or energy resources. Only the drilling of exploratory holes in or near the roadless area could conclusively determine its resource potential for oil and (or) gas.

  11. A review of proposed Glen Canyon Dam interim operating criteria

    SciTech Connect

    LaGory, K.; Hlohowskyj, I.; Tomasko, D.; Hayse, J.; Durham, L.

    1992-04-01

    Three sets of interim operating criteria for Glen Canyon Dam on the Colorado River have been proposed for the period of November 1991, to the completion of the record of decision for the Glen Canyon Dam environmental impact statement (about 1993). These criteria set specific limits on dam releases, including maximum and minimum flows, up-ramp and down-ramp rates, and maximum daily fluctuation. Under the proposed interim criteria, all of these parameters would be reduced relative to historical operating criteria to protect downstream natural resources, including sediment deposits, threatened and endangered fishes, trout, the aquatic food base, and riparian plant communities. The scientific bases of the three sets of proposed operating criteria are evaluated in the present report:(1) criteria proposed by the Research/Scientific Group, associated with the Glen Canyon Environmental Studies (GCES); (2) criteria proposed state and federal officials charged with managing downstream resources; and (3) test criteria imposed from July 1991, to November 1991. Data from Phase 1 of the GCES and other sources established that the targeted natural resources are affected by dam operations, but the specific interim criteria chosen were not supported by any existing studies. It is unlikely that irreversible changes to any of the resources would occur over the interim period if historical operating criteria remained in place. It is likely that adoption of any of the sets of proposed interim operating criteria would reduce the levels of sediment transport and erosion below Glen Canyon Dam; however, these interim criteria could result in some adverse effects, including the accumulation of debris at tributary mouths, a shift of new high-water-zone vegetation into more flood-prone areas, and further declines in vegetation in the old high water zone.

  12. Submarine sand dunes and sedimentary environments in Oceanographer Canyon.

    USGS Publications Warehouse

    Valentine, P.C.; Cooper, R.A.; Uzmann, J.R.

    1984-01-01

    Reveals an extensive field of large sand dunes on the canyon floor. The dunes are medium to coarse sand, are oriented across the axis, and the largest of them are as high as 3m and have wavelengths up to 15m. Their asymmetry, grain size, and height suggest that they are formed by axial currents flowing up- and downcanyon and that the largest dunes require flows of at least 70 cm/sec.-from Authors

  13. Currents in la jolla and scripps submarine canyons.

    PubMed

    Shepard, F P; Marshall, N F

    1969-07-11

    Velocities up to 34 centimeters per second have been recorded near the floors of submarine canyons off La Jolla, California. Currents move alternately down- and upcanyon with variable periods. All 3- to 6-day measurements show net current transport downcanyon. Many of the downcanyon currents of higher velocity correlate with ebbing tides, as measured at the nearby pier. Other factors producing the currents probably include internal waves. Velocities are sufficient to transport large quantities of fine sand. PMID:17834739

  14. Evolution of Paleogene submarine Canyon-Fan systems, southern Sacramento basin, California

    SciTech Connect

    Fischer, P.J.; Cherven, V.B.; Almgren, A.A.

    1986-04-01

    The evolutionary development of the Paleogene Martinez and Meganos Submarine Canyon and Fan systems of the southern Sacramento basin was controlled by a complex interplay of eustatic sea level change and tectonism. In this brief synthesis, the authors postulated that eustatic sea level changes were the dominant or controlling factor, and tectonism, although significant, was of secondary importance. The development of the Paleogene canyon and fan systems is correlated with low sea level stands or regressions at 60 Ma and 56 Ma. Intermittent tectonism, beginning at least 5-10 m.y. earlier, particularly along the western and southwestern margins of the Sacramento basin, controlled the location of the canyon and fan systems. The controlling tectonic elements of the southern basin were north-trending, high-angle faults related to the Kirby Hills and Midland fault zones and the Diablo-Kirby Hills(.) uplift. Both canyons were probably active (that is, channeling coarse sediment to their fans) during most of the late Paleocene. The authors suggest that canyon activity was maintained by south-flowing longshore drift or feeder systems, down-canyon gravity flows (turbidites, etc) and up-down canyon current systems, all of which are typical of modern, active submarine canyon and fan systems. The canyons filled with fine-grained sediments when the canyons were beheaded or separated from the longshore drift system by rising sea level, or when tectonism(.) shifted the major river drainage that supplied the canyon with sediment. Truncation and erosion of the canyon-fill and fan facies of the late Paleocene-early Eocene Meganos Formation along the Diablo outcrop belt was primarily due to the major early middle Eocene lowstand (49.5 Ma).

  15. Distribution and transport of suspended particulate matter in Monterey Canyon, California

    USGS Publications Warehouse

    Xu, J. P.; Noble, M.; Eittreim, S.L.; Rosenfeld, L.K.; Schwing, F.B.; Pilskaln, C.H.

    2002-01-01

    From August 1993 to August 1994, six moorings that measure current, temperature, salinity, and water clarity were deployed along the axis of Monterey Canyon to study the circulation and transport of water and suspended particulate matter through the canyon system. The moorings occupied three sites that are morphologically different: a narrow transverse section (axis width 900 m) at 1450 m water depth, a wide transverse section at 2837 m, and a third site in the fan valley axis farther offshore at 3223 m that recorded for 3 yr. In addition, CTD/transmissometer casts were conducted within and near the Monterey Canyon during four cruises. Our data show a mainly biogenic, surface turbid layer, a limited intermediate nepheloid layer, and a bottom nepheloid layer. There is a consistent presence of a turbid layer within the canyon at a water depth of about 1500 m. Tidal flow dominates at all sites, but currents above the canyon rim and within the canyon appear to belong to two distinct dynamic systems. Bottom intensification of currents plays an important role in raising the near-bottom shear stress high enough that bottom sediments are often, if not always, resuspended. Mean flow pattern suggests a convergence zone between the narrow and wide site: the near-bed (100 m above bottom where the lowest current meter was located) mean transport is down-canyon at the 1450-m site, while the near-bottom transport at the 2837-m site is up-canyon, at a smaller magnitude. Transport at the 3223-m site is dominantly NNW, cross-canyon, with periods of up-canyon flow over 3 yr. A very high-turbidity event was recorded 100 m above the canyon bottom at the narrow site. The event started very abruptly and lasted more than a week. This event was not detected at either of the deeper sites. A canyon head flushing event is likely the cause. ?? 2002 Elsevier Science B.V. All rights reserved.

  16. Late Holocene earthquake history of the Brigham City segment of the Wasatch fault zone at the Hansen Canyon, Kotter Canyon, and Pearsons Canyon trench sites, Box Elder County, Utah

    USGS Publications Warehouse

    DuRoss, Christopher B.; Personius, Stephen F.; Crone, Anthony J.; McDonald, Greg N.; Briggs, Richard W.

    2012-01-01

    Of the five central segments of the Wasatch fault zone (WFZ) having evidence of recurrent Holocene surface-faulting earthquakes, the Brigham City segment (BCS) has the longest elapsed time since its most recent surface-faulting event (~2.1 kyr) compared to its mean recurrence time between events (~1.3 kyr). Thus, the BCS has the highest time-dependent earthquake probability of the central WFZ. We excavated trenches at three sites––the Kotter Canyon and Hansen Canyon sites on the north-central BCS and Pearsons Canyon site on the southern BCS––to determine whether a surface-faulting earthquake younger than 2.1 ka occurred on the BCS. Paleoseismic data for Hansen Canyon and Kotter Canyon confirm that the youngest earthquake on the north-central BCS occurred before 2 ka, consistent with previous north-central BCS investigations at Bowden Canyon and Box Elder Canyon. At Hansen Canyon, the most recent earthquake is constrained to 2.1–4.2 ka and had 0.6–2.5 m of vertical displacement. At Kotter Canyon, we found evidence for two events at 2.5 ± 0.3 ka and 3.5 ± 0.3 ka, with an average displacement per event of 1.9–2.3 m. Paleoseismic data from Pearsons Canyon, on the previously unstudied southern BCS, indicate that a post-2 ka earthquake ruptured this part of the segment. The Pearsons Canyon earthquake occurred at 1.2 ± 0.04 ka and had 0.1–0.8 m of vertical displacement, consistent with our observation of continuous, youthful scarps on the southern 9 km of the BCS having 1–2 m of late Holocene(?) surface offset. The 1.2-ka earthquake on the southern BCS likely represents rupture across the Weber–Brigham City segment boundary from the penultimate Weber-segment earthquake at about 1.1 ka. The Pearsons Canyon data result in a revised length of the BCS that has not ruptured since 2 ka (with time-dependent probability implications), and provide compelling evidence of at least one segment-boundary failure and multi-segment rupture on the central WFZ. Our paleoseismic investigations of the BCS clarify the timing, displacement, and extent of late Holocene earthquakes on the segment, and importantly, confirm the long elapsed time since the most recent earthquake on most of the BCS.

  17. Landslide assessment of Newell Creek Canyon, Oregon City, Oregon

    SciTech Connect

    Growney, L.; Burris, L.; Garletts, D.; Walsh, K. . Dept. of Geology)

    1993-04-01

    A study has been conducted in Newell Creek Canyon near Oregon City, Oregon, T3S, T2S, R2E. A landslide inventory has located 53 landslides in the 2.8 km[sup 2] area. The landslides range in area from approximately 15,000m[sup 2] to 10m[sup 2]. Past slides cover an approximate 7% of the canyon area. Landslide processes include: slump, slump-translational, slump-earthflow and earthflow. Hard, impermeable clay-rich layers in the Troutdale Formation form the failure planes for most of the slides. Slopes composed of Troutdale material may seem to be stable, but when cuts and fills are produced, slope failure is common because of the perched water tables and impermeable failure planes. Good examples of cut and fill failures are present on Highway 213 which passes through Newell Creek Canyon. Almost every cut and fill has failed since the road construction began. The latest failure is in the fill located at mile-post 2.1. From data gathered, a slope stability risk map was generated. Stability risk ratings are divided into three groups: high, moderate and low. High risk of slope instability is designated to all landslides mapped in the slide inventory. Moderate risk is designated to slopes in the Troutdale Formation greater than 8[degree]. Low risk is designated to slopes in the Troutdale Formation less than 8[degree].

  18. Electrical resistance sensors record spring flow timing, Grand Canyon, Arizona

    USGS Publications Warehouse

    Adams, E.A.; Monroe, S.A.; Springer, A.E.; Blasch, K.W.; Bills, D.J.

    2006-01-01

    Springs along the south rim of the Grand Canyon, Arizona, are important ecological and cultural resources in Grand Canyon National Park and are discharge points for regional and local aquifers of the Coconino Plateau. This study evaluated the applicability of electrical resistance (ER) sensors for measuring diffuse, low-stage (<1.0 cm) intermittent and ephemeral flow in the steep, rocky spring-fed tributaries of the south rim. ER sensors were used to conduct a baseline survey of spring flow timing at eight sites in three spring-fed tributaries in Grand Canyon. Sensors were attached to a nearly vertical rock wall at a spring outlet and were installed in alluvial and bedrock channels. Spring flow timing data inferred by the ER sensors were consistent with observations during site visits, with flow events recorded with collocated streamflow gauging stations and with local precipitation gauges. ER sensors were able to distinguish the presence of flow along nearly vertical rock surfaces with flow depths between 0.3 and 1.0 cm. Laboratory experiments confirmed the ability of the sensors to monitor the timing of diffuse flow on impervious surfaces. A comparison of flow patterns along the stream reaches and at springs identified the timing and location of perennial and intermittent flow, and periods of increased evapotranspiration.

  19. Electrical resistance sensors record spring flow timing, Grand Canyon, Arizona.

    PubMed

    Adams, Eric A; Monroe, Stephen A; Springer, Abraham E; Blasch, Kyle W; Bills, Donald J

    2006-01-01

    Springs along the south rim of the Grand Canyon, Arizona, are important ecological and cultural resources in Grand Canyon National Park and are discharge points for regional and local aquifers of the Coconino Plateau. This study evaluated the applicability of electrical resistance (ER) sensors for measuring diffuse, low-stage (<1.0 cm) intermittent and ephemeral flow in the steep, rocky spring-fed tributaries of the south rim. ER sensors were used to conduct a baseline survey of spring flow timing at eight sites in three spring-fed tributaries in Grand Canyon. Sensors were attached to a nearly vertical rock wall at a spring outlet and were installed in alluvial and bedrock channels. Spring flow timing data inferred by the ER sensors were consistent with observations during site visits, with flow events recorded with collocated streamflow gauging stations and with local precipitation gauges. ER sensors were able to distinguish the presence of flow along nearly vertical rock surfaces with flow depths between 0.3 and 1.0 cm. Laboratory experiments confirmed the ability of the sensors to monitor the timing of diffuse flow on impervious surfaces. A comparison of flow patterns along the stream reaches and at springs identified the timing and location of perennial and intermittent flow, and periods of increased evapotranspiration. PMID:16961484

  20. Stratigraphic permeability in the Baca geothermal system, Redondo Creek Area, Valles Caldera, New Mexico

    SciTech Connect

    Hulen, J.B.; Nielson, D.L.

    1982-10-01

    Synthesis of surface and borehole data from the Baca geothermal system, as defined by drilling to date in the Redondo Creek area of the Valles Caldera, New Mexico, indicates that thermal fluid flow in the system is partially controlled by distinct stratigraphic aquifers. These aquifers are relatively thin, laterally restricted beds of non-welded tuff and tuffaceous sandstone, confined primarily to the Quaternary Bandelier Tuff. Recognition of the role of these rocks in reservoir definition at Baca should improve chances for future geothermal discoveries in the Valles Caldera and similar settings elsewhere.

  1. Wrinkle ridges in the floor material of Kasei Valles, Mars: Nature and origin

    NASA Technical Reports Server (NTRS)

    Watters, Thomas R.; Craddock, Robert A.

    1991-01-01

    Wrinkle ridges on Mars occur almost exclusively in smooth plains material referred to as ridged plains. One of the largest contiguous units of ridged plains occurs on Lunae Planum on the eastern flank of the Tharsis rise. The eastern, western, and northern margins of the ridged plains of Lunae Planum suffered extensive erosion in early Amazonian channel-forming events. The most dramatic example of erosion in early Amazonian plains is in Kasei Valles. The nature an origin of the wrinkle ridges in the floor material of Kasei Valles are discussed.

  2. Characteristics of flow and reactive pollutant dispersion in urban street canyons

    NASA Astrophysics Data System (ADS)

    Park, Soo-Jin; Kim, Jae-Jin; Kim, Minjoong J.; Park, Rokjin J.; Cheong, Hyeong-Bin

    2015-05-01

    In this study, the effects of aspect ratio defined as the ratio of building height to street width on the dispersion of reactive pollutants in street canyons were investigated using a coupled CFD-chemistry model. Flow characteristics for different aspect ratios were analyzed first. For each aspect ratio, six emission scenarios with different VOC-NOX ratios were considered. One vortex was generated when the aspect ratio was less than 1.6 (shallow street canyon). When the aspect ratio was greater than 1.6 (deep street canyon), two vortices were formed in the street canyons. Comparing to previous studies on two-dimensional street canyons, the vortex center is slanted toward the upwind building and reverse and downward flows are dominant in street canyons. Near the street bottom, there is a marked difference in flow pattern between in shallow and deep street canyons. Near the street bottom, reverse and downward flows are dominant in shallow street canyon and flow convergence exists near the center of the deep street canyons, which induces a large difference in the NOX and O3 dispersion patterns in the street canyons. NOX concentrations are high near the street bottom and decreases with height. The O3 concentrations are low at high NO concentrations near the street bottom because of NO titration. At a low VOC-NOX ratio, the NO concentrations are sufficiently high to destroy large amount of O3 by titration, resulting in an O3 concentration in the street canyon much lower than the background concentration. At high VOC-NOX ratios, a small amount of O3 is destroyed by NO titration in the lower layer of the street canyons. However, in the upper layer, O3 is formed through the photolysis of NO2 by VOC degradation reactions. As the aspect ratio increases, NOX (O3) concentrations averaged over the street canyons decrease (increase) in the shallow street canyons. This is because outward flow becomes strong and NOX flux toward the outsides of the street canyons increases, resulting in less NO titration. In the deep street canyons, outward flow becomes weak and outward NOX flux decreases, resulting in an increase (decrease) in NOX (O3) concentration.

  3. Recent sea beam mapping of Ascension-Monterey Submarine Canyon System

    SciTech Connect

    Greene, H.G. )

    1990-06-01

    Extensive Sea Beam and Bathymetric Swatch Survey System (BS{sup 3}) data covering the Ascension-Monterey Submarine Canyon system and adjoining areas and canyons were collected offshore central California. Many discovered geomorphological features lead to significant new geologic conclusions about the formation and processes of submarine canyons in general and disclose unique sedimentary and tectonic features of the Ascension-Monterey Canyon system. The highly detailed bathymetric maps constructed from the Sea Beam data indicate that the seafloor topographic pattern is influenced by sedimentary and tectonic processes; both remain active along the central California margin. Interpretations of MOAA composite maps, final raw Sea Beam bathymetric maps, and three-dimensional physiographic renditions from bathymetric data indicate a diverse and complex geomorphology for the Ascension-Monterey Submarine Canyon system and adjoining region. Five distinct geomorphologic provinces and four well-defined geographic areas are mapped. Canyons cut by faults and canyon walls actively undergoing mass wasting are prominently displayed in the Sea Beam data. Sedimentary processes illustrating canyon channel capture and the formation of extensive mega-sedimentary wave fields where the canyons debouch onto the abyssal plain are spectacularly well defined. This new tool of seafloor mapping is contributing significant data for the geological interpretation of continental margins and seafloor in the world's oceans.

  4. Large-scale fault kinematic analysis in Noctis Labyrinthus (Mars)

    NASA Astrophysics Data System (ADS)

    Bistacchi, Nicola; Massironi, Matteo; Baggio, Paolo

    2004-01-01

    Noctis Labyrinthus (Mars) is characterized by many tectonic features, which represent brittle deformation of the crust. This tectonic setting was analysed by remote sensing of the Viking Mars Digital Image Model (MDIM) mosaic and Mars Orbiter Camera (MOC) global mosaic, in order to identify deformational events. The main features are normal faults producing horst-graben structures, strike-slip faults, and related en-echelon and pull-apart basins. Using the criterion of cross-cutting relationships and analysis of secondary structures, to infer sense of movement of faults, two deformational phases were identified in the Noctis Labyrinthus area. The first, D1, located mainly in the northern part, is characterized by transtensional faults (Noachian). The second, D2, recorded in the southern part of the Noctis Labyrinthus by an orthorhombic extensional fault pattern along NNE and WNW trends, is related to the Valles Marineris formation (Late Noachian-Early Hesperian). A third tectonic event, D3, represented by the partly known dextral NW strike-slip faults cross-cutting the Valles Marineris Canyon System (Late Hesperian?-Amazonian?), was not found in Noctis Labyrinthus at the scale and resolution considered.

  5. UV Radiation in an Urban Canyon in Southeast Queensland

    NASA Astrophysics Data System (ADS)

    McKinley, A. R.; Moore, M. R.; Kimlin, M. G.

    2006-12-01

    Ultraviolet radiation (UV) has the possibility to both harm and to benefit human beings when unprotected exposure occurs. After receiving small amounts of UV our bodies begin to synthesise vitamin D, which is essential for maintaining healthy bones, however excessive UV exposure can result in a variety of damaging outcomes ranging from sunburn to skin cancer and cataracts. For this reason it is very important to understand the different environments in which people encounter UV so as to better prepare the public to make smart and healthy sun exposure decisions. Each day more and more people are moving into large cities around the world and spending their time inside the urban canyon, however UV measurements are generally taken at scientific stations in open areas or on top of tall buildings, meaning that at times the environmental characteristics measured may not accurately represent those found at street-level in these highly urbanized areas. Urban canyons are home to both very tall buildings and tropospheric air pollution, each of which reduces the amount of UV reaching street-level. This study measured the varying difference between UV measurements taken at street-level and at a standard UV monitoring site on top of a building outside of the urban canyon. Investigation was conducted in the central business district (CBD) of Brisbane, Australia, which models the CBDs of large cities around the world in that it boasts a great number of tall buildings, including many skyscrapers. Data was collected under clear sky conditions at five different street-level sites in the CBD (on either side of two streets running perpendicular to one another (four sites) and in a public square) and then compared to that obtained on the same day at the Queensland University of Technology's Australian Sun and Health Research Laboratory (ASHRL), which is located 2.5 kilometres outside Brisbane's CBD. Minimum erythemal dose (MED) data was collected at each location and it was found that throughout the day the intensity of erythemal UV measured in the city was significantly lower than that measured at the ASHRL site. On average the amount of erythemal UV measured in the urban canyon was approximately 33% of that measured at the ASHRL site. Based upon these findings we hope to conduct further study regarding UV exposure in the urban canyon.

  6. Distinct Benthic Community Trends Driven by Particle Transport and Deposition in Mid-Atlantic Bight Canyons, NW Atlantic

    NASA Astrophysics Data System (ADS)

    Demopoulos, A. W.; Robertson, C. M.; Bourque, J. R.; Mienis, F.; Duineveld, G.; Ross, S.; Brooke, S.; Davies, A. J.

    2014-12-01

    The Mid-Atlantic Bight (MAB) is a well-studied region of the U.S. East coast continental margin, rich in submarine canyons. Baltimore and Norfolk canyons were studied during the multidisciplinary Atlantic Deepwater Canyons project through funding from BOEM, NOAA, and USGS. Sediment and water column properties were assessed in the context of canyon physical dynamics and ecosystem ecology. Sediment samples were collected by NIOZ box corer in 2012 and 2013 along canyon axes and comparative adjacent slopes at standardized depths. Sediments were analyzed for grain size, organic content, stable carbon and nitrogen isotopes, chlorophyll a, and benthic infauna. Water column properties were sampled using CTD transects, and benthic landers and moorings positioned along canyon axes. Significant differences in sediment transport regimes were found for each canyon where observed nepheloid layers corresponded to shifts in infaunal community structure. Significant community shifts were observed in stations at depths > 900m in Baltimore Canyon, coinciding with higher organic matter concentrations at depths below the nepheloid layer. In contrast, adjacent slope communities exhibited a more uniform infaunal assemblage where distinct zonation patterns by depth were observed. Preliminary data for Norfolk Canyon suggest very different sediment deposition rates in the canyon and also show clear differences between canyon and slope benthic communities. Geological processes and canyon topography coupled with organic inputs and disturbance events are clear factors in determining benthic infaunal diversity and standing stock dynamics in and around these canyons.

  7. Restoring Anadromous Fish Habitat in Big Canyon Creek Watershed; Anadromous Fish Habitat Restoration in the Nichols Canyon Subwatershed, 2000 Annual Report.

    SciTech Connect

    Koziol, Deb

    2001-02-01

    Nez Perce Soil & Water Conservation District (NPSWCD) undertook the Nichols Canyon Subwatershed Steelhead Trout Habitat Improvement Project in the spring of 1999 with funding from a grant through the Bonneville Power Administration. The Project's purpose is to install and implement agricultural best management practices (MBPS) and riparian restorations with the goal of improving steelhead trout spawning and rearing habitat in the subwatershed. Improvements to fish habitat in the Big Canyon Creek tributaries enhances natural production of the species in Big Canyon Creek and ultimately the Clearwater River. This report is a summation of the progress made by the NPSWCD in the Project's second year.

  8. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea

    PubMed Central

    De Leo, Fabio C.; Smith, Craig R.; Rowden, Ashley A.; Bowden, David A.; Clark, Malcolm R.

    2010-01-01

    Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42°01? S, 173°03? E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study. PMID:20444722

  9. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea.

    PubMed

    De Leo, Fabio C; Smith, Craig R; Rowden, Ashley A; Bowden, David A; Clark, Malcolm R

    2010-09-22

    Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42 degrees 01' S, 173 degrees 03' E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study. PMID:20444722

  10. 75 FR 18201 - Juniper Canyon Wind Power, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ...Commission [Docket No. ER10-975-000] Juniper Canyon Wind Power, LLC; Supplemental Notice That Initial Market-Based...in the above-referenced proceeding of Juniper Canyon Wind Power, LLC's application for market-based rate...

  11. 76 FR 9347 - Coyote Canyon Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ...Energy Regulatory Commission [Docket No. ER11-2860-000] Coyote Canyon Energy LLC; Supplemental Notice That Initial Market-Based...supplemental notice in the above-referenced proceeding of Coyote Canyon Energy LLC's application for market-based rate...

  12. 75 FR 19966 - Boulder Canyon Project-Post-2017 Application of the Energy Planning and Management Program Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ...Power Administration Boulder Canyon Project--Post-2017 Application of the Energy Planning and Management Program Power Marketing Initiative...part 905) to the Boulder Canyon Project (BCP). This Federal Register...

  13. 33 CFR 165.840 - Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South of New Orleans, LA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED...840 Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20,...

  14. 33 CFR 165.840 - Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South of New Orleans, LA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20, South...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED...840 Regulated Navigation Area, Gulf of Mexico: Mississippi Canyon Block 20,...

  15. Comment on "Athabasca Valles, Mars: a lava-draped channel system".

    PubMed

    Page, David P

    2008-06-20

    Jaeger et al. (Reports, 21 September 2007, p. 1709) presented images of the Athabasca Valles channel system on Mars and asserted that the observed deposits are composed of thin, fluid lavas. However, all the features they described are secondary and postdate the surface by many millions of years, as documented by structural relationships with small, young impact craters. PMID:18566267

  16. Dynamics of the Formation and Decay of Coherence in a Polariton Condensate E. del Valle,1

    E-print Network

    Viña, Luis

    Dynamics of the Formation and Decay of Coherence in a Polariton Condensate E. del Valle,1 D the dynamics of the formation and decay of a condensate of microcavity polaritons. We investigate alternative to investigate the process of condensate forma- tion is that of microcavity polaritons [1

  17. Coordinacin de la Especializacin en Ingeniera del Gas Natural Valle de Sartenejas, Universidad Simn Bolvar,

    E-print Network

    Vásquez, Carlos

    Coordinación de la Especialización en Ingeniería del Gas Natural Valle de Sartenejas, Universidad DEL GAS NATURAL Grado académico que otorga Especialista en Ingeniería del Gas Natural. Perfil de egresado El egresado de la Especialización del Gas Natural tendrá la competencia para: Manejar y aplicar

  18. Time-optimal Paths for a Dubins airplane Hamidreza Chitsaz and Steven M. LaValle

    E-print Network

    LaValle, Steven M.

    Time-optimal Paths for a Dubins airplane Hamidreza Chitsaz and Steven M. LaValle Abstract-- We consider finding a time-optimal trajectory for an airplane from some starting point and orientation to some to Dubins airplane. We assume that the system has independent bounded control over the altitude velocity

  19. Spectacular Cataracts (Dry Falls) on the Floor of Kasei Valles, Mars

    NASA Astrophysics Data System (ADS)

    Coleman, N.

    2010-03-01

    The largest known cataracts exist on the floor of Kasei Valles. These spectacular dry falls have a vertical relief of ~500 m, and may have migrated by headward erosion as much as 250 km. They are characterized using THEMIS images and MOLA data.

  20. A tectonically controlled basin-fill within the Valle del Cauca, West-Central Colombia

    SciTech Connect

    Rine, J.M.; Keith, J.F. Jr.; Alfonso, C.A.; Ballesteros, I.; Laverde, F.; Sacks, P.E.; Secor, D.T. Jr. ); Perez, V.E.; Bernal, I.; Cordoba, F.; Numpaque, L.E. )

    1993-02-01

    Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordillera Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

  1. Initial insights from 2.5D hydraulic modeling of floods in Athabasca Valles, Mars

    E-print Network

    Kah, Linda

    that it empties into, are covered with platy-ridged material that new images have shown to be lava [Jaeger et alInitial insights from 2.5D hydraulic modeling of floods in Athabasca Valles, Mars L. P. Keszthelyi.5D hydraulic model to catastrophic floods on Mars. This model simulates flow over complex topography

  2. MESOSPHERIC RETRIEVALS FROM MIPAS Luis F. Millan-Valle and A. Dudhia

    E-print Network

    Oxford, University of

    MESOSPHERIC RETRIEVALS FROM MIPAS Luis F. Mill´an-Valle and A. Dudhia Oxford University, Parks Road to retrieve tem- perature, pressure and composition at lower mesospheric altitudes using the limb radiances on the assumption that at mesospheric heights, due to the thin optical path, the re- trieval can be treated linearly

  3. Hydrology in the Durius Valles Region: Evaluation of Possible Correlation with Volcanism and Magnetic Anomalies

    NASA Technical Reports Server (NTRS)

    Cabrol, Natalie A.; Marinangeli, Lucia; Grin, Edmond A.

    2000-01-01

    We envision the contribution of subglacial flows, hydrothermalism and sapping in the Durius Valles system and the consequences in term of climate on Mars in recent geological times. We evaluate the possible correlation of the hydrology with volcanism and magnetic anomalies.

  4. Channeling episodes of Kasei Valles, Mars, and the nature of ridged plains material

    NASA Technical Reports Server (NTRS)

    Chapman, Mary G.; Tanaka, Kenneth L.

    1991-01-01

    The geologic mapping compiled at 1:500,000 scale of the northern Kasei Valles area of Mars (MTMs 25062 and 25067) indicates (1) at least three periods of Kasei Valles channeling, (2) the development of Sacra Fossae (linear depressions on Tempe Terra and Lunae Planum) in relation to Kasei channeling episodes, and (3) the nature of ridged plains material dissected by Kasei Valles on northern Lunae Planum. (The three channeling periods consists of two flood events and a later, sapping related event). These findings suggest hydrologic conditions and processes that formed Kasei Valles and associated features and terrains. It is concluded that an early period of flooding, whose source is perhaps buried beneath lava flows of Tharsis Montes, may have eroded streamlined features in northern Lunae Planum. Also, later floods originating from Echus Chasma formed after the initial flooding and the mesas adjacent to the plateau. The Sacra Fossae formed after the initial flooding and during the second flooding by sapping, outbreak, scarp retreat, and collapse along joints and fractures in ridged plains materials.

  5. Challenges in real-time virtualization and predictable cloud computing Marisol Garca-Valls a,

    E-print Network

    Lu, Chenyang

    Challenges in real-time virtualization and predictable cloud computing Marisol García-Valls a 2014 Keywords: Cloud computing Soft real-time systems Virtualization Resource management Quality of service SLA a b s t r a c t Cloud computing and virtualization technology have revolutionized general

  6. Bayesian Region Merging Probability for Parametric Image Steven M. LaValle .. Seth A. Hutchinson

    E-print Network

    Hutchinson, Seth

    Bayesian Region Merging Probability for Parametric Image Models1 Steven M. LaValle .. Seth A describe a novel Bayesian approach to re- gion merging, which directly uses statistical image models- tion. This approach is particularly beneficialfor cases in which the merging decision is most likely

  7. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable Waters... Coast Guard District § 165.1155 Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach... surface to bottom, within a 2,000 yard radius of Diablo Canyon Nuclear Power Plant centered at position...

  8. 75 FR 8152 - Pacific Gas and Electric Company; Diablo Canyon Power Plant Environmental Assessment and Finding...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... COMMISSION Pacific Gas and Electric Company; Diablo Canyon Power Plant Environmental Assessment and Finding... Pacific Gas and Electric Company (PG&E, the licensee), for operation of the Diablo Canyon Power Plant... Part 73 as discussed in a Federal Register notice dated March 27, 2009 (74 FR 13926). There will be...

  9. Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

    E-print Network

    Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA Cassandra R Received 6 May 2005 Availble online 7 February 2006 Abstract The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366

  10. Amphitheater-headed canyons formed by megaflooding at Malad Gorge, Idaho

    PubMed Central

    Lamb, Michael P.; Mackey, Benjamin H.; Farley, Kenneth A.

    2014-01-01

    Many bedrock canyons on Earth and Mars were eroded by upstream propagating headwalls, and a prominent goal in geomorphology and planetary science is to determine formation processes from canyon morphology. A diagnostic link between process and form remains highly controversial, however, and field investigations that isolate controls on canyon morphology are needed. Here we investigate the origin of Malad Gorge, Idaho, a canyon system cut into basalt with three remarkably distinct heads: two with amphitheater headwalls and the third housing the active Wood River and ending in a 7% grade knickzone. Scoured rims of the headwalls, relict plunge pools, sediment-transport constraints, and cosmogenic (3He) exposure ages indicate formation of the amphitheater-headed canyons by large-scale flooding ?46 ka, coeval with formation of Box Canyon 18 km to the south as well as the eruption of McKinney Butte Basalt, suggesting widespread canyon formation following lava-flow diversion of the paleo-Wood River. Exposure ages within the knickzone-headed canyon indicate progressive upstream younging of strath terraces and a knickzone propagation rate of 2.5 cm/y over at least the past 33 ka. Results point to a potential diagnostic link between vertical amphitheater headwalls in basalt and rapid erosion during megaflooding due to the onset of block toppling, rather than previous interpretations of seepage erosion, with implications for quantifying the early hydrosphere of Mars. PMID:24344293

  11. 75 FR 439 - Glen Canyon Dam Adaptive Management Work Group (AMWG)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group (AMWG) AGENCY: Bureau of Reclamation.... L. 102-575) of 1992. The AMP includes a Federal advisory committee, the Adaptive Management Work Group (AMWG), a Technical Work Group (TWG), a Grand Canyon Monitoring and Research Center,...

  12. 75 FR 44809 - Glen Canyon Dam Adaptive Management Work Group (AMWG)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group (AMWG) AGENCY: Bureau of Reclamation.... L. 102-575) of 1992. The AMP includes a Federal advisory committee, the Adaptive Management Work Group (AMWG), a technical work group (TWG), a Grand Canyon Monitoring and Research Center,...

  13. 76 FR 584 - Glen Canyon Dam Adaptive Management Program Work Group (AMWG)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Program Work Group (AMWG) AGENCY: Bureau of... Management Work Group (AMWG), a technical work group (TWG), a Grand Canyon Monitoring and Research Center... addition, there will be updates from the Charter Ad Hoc Group and a follow up report on the work done...

  14. A seismic stratigraphic analysis of Miocene deposits in the Baltimore Canyon region (off-

    E-print Network

    Poulsen, Chris J.

    ABSTRACT A seismic stratigraphic analysis of Miocene deposits in the Baltimore Canyon region (off-strike variability. In this study, a seismic stratigraphic analysis of middle to late Miocene siliciclastic deposits model. Second, seismic data from the Bal- timore Canyon a

  15. 76 FR 42654 - Endangered and Threatened Wildlife and Plants; Petition To List Grand Canyon Cave Pseudoscorpion

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ...incorrectly referenced as the Grand Canyon cave scorpion) was in that group of 67 species. Based...lacking a telson, or stinger, that true scorpions possess. The specimen of Grand Canyon...Cave, Land's End Cave, Middle Cave, Scorpion Cave, Tse An Cho Cave, Tuning...

  16. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... construction or alterations. The provisions of this paragraph apply to the privately owned lands within...

  17. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... construction or alterations. The provisions of this paragraph apply to the privately owned lands within...

  18. 76 FR 23335 - Wilderness Stewardship Plan/Environmental Impact Statement, Sequoia and Kings Canyon National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-26

    ... National Park Service Wilderness Stewardship Plan/Environmental Impact Statement, Sequoia and Kings Canyon... Intent to Prepare Environmental Impact Statement for Wilderness Stewardship Plan, Sequoia and Kings... Act of 1969 (PL91-190) Sequoia and Kings Canyon National Parks (SEKI) are initiating the...

  19. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... construction or alterations. The provisions of this paragraph apply to the privately owned lands within...

  20. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... construction or alterations. The provisions of this paragraph apply to the privately owned lands within...

  1. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... construction or alterations. The provisions of this paragraph apply to the privately owned lands within...

  2. 36 CFR 7.53 - Black Canyon of the Gunnison National Monument.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Black Canyon of the Gunnison National Monument. 7.53 Section 7.53 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.53 Black Canyon of...

  3. 36 CFR 7.53 - Black Canyon of the Gunnison National Monument.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Black Canyon of the Gunnison National Monument. 7.53 Section 7.53 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.53 Black Canyon of...

  4. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable Waters... Coast Guard District § 165.1155 Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach... surface to bottom, within a 2,000 yard radius of Diablo Canyon Nuclear Power Plant centered at position...

  5. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable Waters... Coast Guard District § 165.1155 Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach... surface to bottom, within a 2,000 yard radius of Diablo Canyon Nuclear Power Plant centered at position...

  6. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable Waters... Coast Guard District § 165.1155 Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach... surface to bottom, within a 2,000 yard radius of Diablo Canyon Nuclear Power Plant centered at position...

  7. Amphitheater-headed canyons formed by megaflooding at Malad Gorge, Idaho.

    PubMed

    Lamb, Michael P; Mackey, Benjamin H; Farley, Kenneth A

    2014-01-01

    Many bedrock canyons on Earth and Mars were eroded by upstream propagating headwalls, and a prominent goal in geomorphology and planetary science is to determine formation processes from canyon morphology. A diagnostic link between process and form remains highly controversial, however, and field investigations that isolate controls on canyon morphology are needed. Here we investigate the origin of Malad Gorge, Idaho, a canyon system cut into basalt with three remarkably distinct heads: two with amphitheater headwalls and the third housing the active Wood River and ending in a 7% grade knickzone. Scoured rims of the headwalls, relict plunge pools, sediment-transport constraints, and cosmogenic ((3)He) exposure ages indicate formation of the amphitheater-headed canyons by large-scale flooding ?46 ka, coeval with formation of Box Canyon 18 km to the south as well as the eruption of McKinney Butte Basalt, suggesting widespread canyon formation following lava-flow diversion of the paleo-Wood River. Exposure ages within the knickzone-headed canyon indicate progressive upstream younging of strath terraces and a knickzone propagation rate of 2.5 cm/y over at least the past 33 ka. Results point to a potential diagnostic link between vertical amphitheater headwalls in basalt and rapid erosion during megaflooding due to the onset of block toppling, rather than previous interpretations of seepage erosion, with implications for quantifying the early hydrosphere of Mars. PMID:24344293

  8. 75 FR 27550 - Electrical Interconnection of the Juniper Canyon I Wind Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... Bonneville Power Administration Electrical Interconnection of the Juniper Canyon I Wind Project AGENCY... proposed Juniper Canyon I Wind Energy Project (Wind Project) in Klickitat County, Washington. To interconnect the Wind Project, BPA will expand an existing substation (Rock Creek Substation) by...

  9. INFLUENCE OF GEOMETRY ON THE MEAN FLOW WITHIN URBAN STREET CANYONS A COMPARISON OF WIND TUNNEL

    E-print Network

    Savory, Eric

    the canyon, the smaller the wind speed close to the cavity ground, giving increasingly poor ventilation, ventilation, vortex Nomenclature d = Displacement height (m); H, W = Height and width of canyon (m); k-1 ); Water, Air, and Soil Pollution: Focus 2: 365­380, 2002. © 2002 Kluwer Academic Publishers

  10. Canyon-related undulation structures in the Shenhu area, northern South China Sea

    NASA Astrophysics Data System (ADS)

    Qiao, Shaohua; Su, Ming; Kuang, Zenggui; Yang, Rui; Liang, Jinqiang; Wu, Nengyou

    2015-09-01

    The characteristics and origin of seafloor and subsurface undulations were studied in the Shenhu area, northern South China Sea using high-precision multibeam bathymetric map and high-resolution 2D seismic data. Two undulation structure fields associated with submarine canyons have been identified. One structure field is developed in canyon head areas and shows waveform morphology on the bathymetric map. The waves display wavelengths and wave heights of 1-2 km and 20-50 m, respectively, generally occur on slopes from 1° to 5°, and extend for about 15 km approximately parallel to the canyon's orientation. The other structure field is developed in the lower segment or mouth area of submarine canyons. In general, the waves display wavelengths and wave heights of 1.3-3.6 km and 50-80 m, respectively, occur on slopes of approximately 2°, and extend for more than 20 km. Sediment cores from crests between submarine canyons in the lower segment include predominantly silts and clayey silts. Since undulations in the two fields show differences in morphology and internal architectures, two different formation mechanisms are suggested. Seafloor undulations in the head area of submarine canyons are interpreted as creep folds induced by soft sediment deformation. Undulation structures in the lower segment or the mouth area of submarine canyons are sediment waves constructed by turbidity currents overflows along the submarine canyons.

  11. Delaware River: Evidence for its former extension to Wilmington Submarine Canyon

    USGS Publications Warehouse

    Twichell, D.C.; Knebel, H. J.; Folger, D.W.

    1977-01-01

    Seismic-reflection profiles indicate that during the Pleistocene the Delaware River flowed across the continental shelf east of Delaware Bay and emptied into Wilmington Submarine Canyon. The ancestral valley (width, 3 to 8 kilometers; relief, 10 to 30 meters) is buried, is not reflected in the surface topography, and probably predates the formation of the present canyon head.

  12. Numerical Study on the Effects of Building-Roof Cooling in Urban Street Canyons

    NASA Astrophysics Data System (ADS)

    Kim, J.

    2013-12-01

    The effects of building-roof cooling on flow and air temperature in urban street canyons are numerically investigated using a computational fluid dynamics (CFD) model. The aspect ratios of the building and street canyon considered are one. For investigating the building-roof cooling effects, the building-roof temperatures are systematically changed. The traditional flow pattern including a portal vortex appears in the spanwise canyon. Compared with the case of the control run, there is no big difference in flow pattern in the case of Rf_10 in which the maximum building-roof cooling is considered. However, as the building roof becomes cooler, the mean kinetic energy increases and the air temperature decreases in the spanwise canyon. Building-roof cooling suppresses the upward and inward motions above the building roof, resultantly increasing the horizontal velocity near the roof level. The increase in wind velocity above the roof level intensifies the secondarily driven vortex circulation as well as the inward (outward) motion into (out of) the spanwise canyon. Finally, building-roof cooling reduces the air temperature in the spanwise canyon, supplying much relatively cool air from the streamwise canyon into the spanwise canyon.

  13. Operation of Glen Canyon Dam. Final environmental impact statement, summary, comments and responses

    SciTech Connect

    1995-03-01

    The Federal action considered in this environmental impact statement (EIS) is the operation of Glen Canyon Dam, Colorado River Storage Project (CRSP), Arizona. The purpose of the reevaluation is to determine specific options that could be implemented to minimize--consistent with law-adverse impacts on the downstream environmental and cultural resources, as well as Native American interests in Glen and Grand Canyons.

  14. A reconnaissance of the Archean complex of the Granite Gorge, Grand Canyon, Arizona

    USGS Publications Warehouse

    Noble, L.F.; Hunter, J. Fred

    1917-01-01

    The field work upon which this article is based was done in March and April, 1914. From Garnet Canyon, near the west end of the Granite Gorge, the route followed the Tonto trail along the so-called lower plateau, or Tonto platform, to Red Canyon, at the east end of the Granite Gorge.

  15. The Grand Canyon and Other Holes in the Ground. Natural Wonder Notebook.

    ERIC Educational Resources Information Center

    Markle, Sandra

    1983-01-01

    The Grand Canyon, the natural wonder visited most often in the United States, is explored on foot, on burro, and by boat in this article. Learn about the canyon's different rock layers as well as its erosion, plant life, animal life, and water flow. (JM)

  16. 78 FR 25404 - Proposed Establishment of Class E Airspace; Grand Canyon, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-01

    ...This action proposes to establish Class E airspace at the Grand Canyon VHF Omni-Directional Radio Range/Distance Measuring Equipment (VOR/DME) navigation aid, Grand Canyon, AZ, to facilitate vectoring of Instrument Flight Rules (IFR) aircraft under control of Los Angeles Air Route Traffic Control Center (ARTCC). The FAA is proposing this action to enhance the safety and management of aircraft......

  17. Geologic Map of MTM -20012 and -25012 Quadrangles, Margaritifer Terra Region of Mars

    USGS Publications Warehouse

    Grant, J.A.; Wilson, S.A.; Fortezzo, C.M.; Clark, D.A.

    2009-01-01

    Mars Transverse Mercator (MTM) -20012 and -25012 quadrangles (lat 17.5 deg - 27.5 deg S., long 345 deg - 350 deg E.) cover a portion of Margaritifer Terra near the east end of Valles Marineris. The map area consists of a diverse assemblage of geologic surfaces including isolated knobs of rugged mountainous material, heavily cratered and dissected ancient highland material, a variety of plains materials, chaotic terrain materials, and one of the highest densities of preserved valleys and their associated deposits on the planet (Saunders, 1979; Baker, 1982; Phillips and others, 2000, 2001). The map area is centered on a degraded, partially filled, ~200-km-diameter impact structure (lat 22 deg S., long 347.5 deg E.), informally referred to as Parana basin, located between Parana Valles to the east and Loire Valles to the west. Parana Valles is a network of multidigitate, mostly east-west-oriented valleys that flowed west and discharged into Parana basin (Grant, 1987, 2000; Grant and Parker, 2002). Loire Valles, broadly comparable in length to the Grand Canyon on Earth, has a deeply incised channel within the map area that originates at the west-northwest edge of Erythraeum Chaos within Parana basin (Grant, 1987, 2000; Grant and Parker, 2002; Strom and others, 2000). Parana and Loire Valles, combined with Samara Valles to the west, form one of the most laterally extensive, well-integrated valley networks on Mars (Grant, 2000) and record a long history of modification by fluvial processes. The origin and morphology of the valley networks, therefore, provide insight into past environmental conditions, whereas their relation with other landforms helps constrain the timing and role of fluvial processes in the evolution and modification of the Margaritifer Terra region.

  18. 76 FR 47237 - Notice of Public Meeting for the Glen Canyon Dam Adaptive Management Work Group Federal Advisory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... Bureau of Reclamation Notice of Public Meeting for the Glen Canyon Dam Adaptive Management Work Group... Canyon Dam Adaptive Management Work Group (AMWG) makes recommendations to the Secretary of the Interior..., the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and Research Center, and...

  19. Sediment storage and reworkingon the shelf and in the Canyon of the Indus River-Fan Systemsince the

    E-print Network

    Clift, Peter

    , reworking and recycling both on the shelf and within the submarine canyon prior to its deposition, so from source areas. In this study, we have examined the role that the shelf and submarine canyon playSediment storage and reworkingon the shelf and in the Canyon of the Indus River-Fan Systemsince

  20. Submarine canyons and channels in the Lower St. Lawrence Estuary (Eastern Canada): Morphology, classification and recent sediment dynamics

    E-print Network

    Submarine canyons and channels in the Lower St. Lawrence Estuary (Eastern Canada): Morphology online 8 April 2015 Keywords: Submarine canyons Gravity flows St. Lawrence Estuary Seabed morphology Sedimentary processes Series of submarine canyons and channels observed in the Lower St. Lawrence Estuary

  1. Multiple fluvial processes detected by riverside seismic and infrasound monitoring of a controlled flood in the Grand Canyon

    E-print Network

    Tsai, Victor C.

    flood in the Grand Canyon Brandon Schmandt,1 Richard C. Aster,2,3 Dirk Scherler,4 Victor C. Tsai,4 experiment (CFE) in the Grand Canyon to show that three types of fluvial processes can be monitored from of a controlled flood in the Grand Canyon, Geophys. Res. Lett., 40, 4858­4863, doi:10.1002/grl.50953. 1

  2. Response to Comments on “Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon”

    NASA Astrophysics Data System (ADS)

    Flowers, R. M.; Farley, K. A.

    2013-04-01

    We reiterate that geological observations do not require Grand Canyon carving coeval with Colorado River integration. (U-Th)/He data from the western canyon, totaling 29 reproducible analyses from six samples and two labs, compellingly support an ancient canyon. Three dispersed analyses from one anomalous sample do not refute this conclusion, nor do the claimed shortcomings of our modeling have validity.

  3. Changes in the water surface profile of the Colorado River in Grand Canyon, Arizona, between 1923 and 2000

    E-print Network

    Changes in the water surface profile of the Colorado River in Grand Canyon, Arizona, between 1923 of the Colorado River through Grand Canyon with theodolite and stadia rod. In 2000, lidar overflights collected throughout Grand Canyon. In addition, comparison of the two water surface profiles showed enhanced pool

  4. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Grand Canyon National Park, AZ Appendix to Subpart U of Part 93 Aeronautics and Space FEDERAL AVIATION... TRAFFIC RULES Special Flight Rules in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App. Appendix to Subpart U of Part 93—Special Flight Rules in the Vicinity of the Grand Canyon National Park,...

  5. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Grand Canyon National Park, AZ Appendix to Subpart U of Part 93 Aeronautics and Space FEDERAL AVIATION... TRAFFIC RULES Special Flight Rules in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App. Appendix to Subpart U of Part 93—Special Flight Rules in the Vicinity of the Grand Canyon National Park,...

  6. Response to Comments on "Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon".

    PubMed

    Flowers, R M; Farley, K A

    2013-04-12

    We reiterate that geological observations do not require Grand Canyon carving coeval with Colorado River integration. (U-Th)/He data from the western canyon, totaling 29 reproducible analyses from six samples and two labs, compellingly support an ancient canyon. Three dispersed analyses from one anomalous sample do not refute this conclusion, nor do the claimed shortcomings of our modeling have validity. PMID:23580513

  7. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Grand Canyon National Park, AZ Appendix to Subpart U of Part 93 Aeronautics and Space FEDERAL AVIATION... TRAFFIC RULES Special Flight Rules in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App. Appendix to Subpart U of Part 93—Special Flight Rules in the Vicinity of the Grand Canyon National Park,...

  8. Frequency and initiation of debris flows in Grand Canyon, Arizona Peter G. Griffiths and Robert H. Webb

    E-print Network

    Frequency and initiation of debris flows in Grand Canyon, Arizona Peter G. Griffiths and Robert H 2004. [1] Debris flows from 740 tributaries transport sediment into the Colorado River in Grand Canyon River in Grand Canyon, and repeat photography provides a 100 year record of debris flows from 147

  9. Rapid changes in the head of the Rio Balsas Submarine Canyon system, Mexico

    USGS Publications Warehouse

    Reimnitz, E.; Gutierrez-Estrada, M.

    1970-01-01

    The investigation of a river delta and the heads of several nearby submarine canyons in western Mexico produced evidence for rapid changes in the configuration and depth of the nearshore portions of canyon tributaries. General scarcity of data on the rates of submarine canyon formation and the relationship to river discharge should make these results of special interest. The Rio Balsas, one of Mexico's largest rivers, empties into the ocean near the heads of a large submarine canyon that terminates in the Middle America Trench. One of the distributaries of the Rio Balsas presently is discharging at the head of Can??o??n de la Necesidad, which is being eroded actively. Two inactive canyons are related to former discharge channels of the river. Their heads lie at some distance from shore and are being filled with sediment. The Can??o??n de Petacalco, not now receiving sediment directly from a Rio Balsas distributary, has remained active because the shoreline has not retreated far. Until about 100 years ago its head was being filled with fine-grained and highly organic sediments from a nearby rivermouth, while the coarse portion of the sediment supply joined the canyon via a tributary farther seaward. Since then the river has shifted away from this canyon, and the horizontally stratified sediments in the canyon head have been incised as much as 20-30 m, as evidenced by three 14C dates of organic material exposed in the steep to overhanging canyon walls. The changes in the shallow portion of the Rio Balsas submarine canyons seem to be related to changes in river discharge pattern, either directly or indirectly. A shifting point source of sediment supply either activates a pre-existing, partly filled canyon, or erodes a new one near the new river mouth, whereas the canyon at the abandoned river mouth is deactivated following retreat of the shoreline. The heads of the different tributaries form a dendritic pattern in Holocene unconsolidated sediment. Subaerial processes are not involved in the formation of these submarine canyons. Thus, a dendritic pattern of submarine canyons is not necessarily indicative of subaerial erosion. ?? 1970.

  10. Variability in turbidity current frequency within a central Portuguese margin canyon

    NASA Astrophysics Data System (ADS)

    Allin, Joshua R.; Talling, Peter J.; Hunt, James E.; Clare, Michael E.; Pope, Ed

    2015-04-01

    Submarine canyons constitute one of the most important pathways for sediment transport into ocean basins. For this reason, understanding canyon architecture and sedimentary processes has significance for oil and gas reservoir characterisation, carbon budgets and geohazard assessment. Canyon sedimentation in the form of turbidity-currents is known to operate on a variety of scales and result from a number of different processes, including landslides, river-derived hyperpycnal flows and tidal or storm resuspension. Despite the expanding knowledge of turbidity current triggers, the spatial variability in turbidity current frequency within most canyon systems is not well defined. Here, new chronologies from cores in the lower reaches of Nazaré Canyon illustrate changes in turbidity current frequency and their relationship to sea level. These flows were relatively frequent during the last glacial maximum and the last deglaciation, with an average recurrence interval of ~70 years. Mid to early Holocene slowdown in activity (avg. recurrence of 1625 years) appears to occur later than other systems along the Iberian margin. Cores from the Iberian Abyssal Plain also provide the first recurrence interval estimates for large run-out turbidity currents from the central Portuguese margin. These large turbidity currents have an average recurrence interval of 2750 years, broadly comparable to modern turbidity flow events in the lower Nazaré Canyon. This indicates that Nazaré Canyon acted as a depocentre, capturing large volumes of sediment during glacial periods prior to large scale canyon flushing events. However, this sediment capture has largely been restricted to the middle and upper canyon since stabilisation of Holocene sea level. Recurrence intervals suggest that large turbidity flows which flush the canyon operate on a timescale independent of the sea level forcing evident in the lower canyon. While instability-triggered landsliding and tidal/storm resuspension are likely responsible for canyon restricted turbidity flows, a different trigger may exist for long run-out turbidity flows capable of travelling several hundred kilometres. Canyon flushing events in other systems have been suggested as resulting from landslides triggered by regional earthquakes. However, turbidites from the Iberian Abyssal Plain do not correlate well with previously suggested earthquake-triggered landslides in the Tagus Abyssal Plain to the south. The inconclusiveness of a test for synchronous deposition in distinct basins makes identifying a seismic trigger problematic. The Nazaré fault, which intersects the canyon head, may have a distinct return time for large earthquakes that is different from seismically active areas to the south. This further suggests the need for caution in the use of turbidites as a palaeo-seismological indicator along the Iberian margin.

  11. Small mammal study of Sandia Canyon, 1994 and 1995

    SciTech Connect

    Bennett, K.; Biggs, J.

    1996-11-01

    A wide range of plant and wildlife species utilize water discharged from facilities at Los Alamos National Laboratory (LANL). The purpose of this study was to gather baseline data of small mammal populations and compare small mammal characteristics within three areas of Sandia Canyon, which receives outfall effluents from multiple sources. Three small mammal trapping webs were placed in the upper portion of Sandia Canyon, the first two were centered in a cattail-dominated marsh with a ponderosa pine overstory and the third web was placed in a much drier transition area with a ponderosa pine overstory. Webs 1 and 2 had the highest species diversity indices with deer mice the most commonly captured species in all webs. However, at Web 1, voles, shrews, and harvest mice, species more commonly found in moist habitats, made up a much greater overall percentage (65.6%) than did deer mice and brush mice (34.5%). The highest densities and biomass of animals were found in Web 1 with a continual decrease in density estimates in each web downstream. There is no statistical difference between the mean body weights of deer mice and brush mice between sites. Mean body length was also determined not to be statistically different between the webs (GLM [deer mouse], F = 0.89, p = 0.4117; GLM [brush mouse], F = 2.49, p = 0.0999). Furthermore, no statistical difference between webs was found for the mean lean body masses of deer and brush mice (GLM [deer mouse], F = 2.54, p = 0.0838; GLM [brush mouse], F = 1.60, p = 0.2229). Additional monitoring studies should be conducted in Sandia Canyon so comparisons over time can be made. In addition, rodent tissues should be sampled for contaminants and then compared to background or control populations elsewhere at the Laboratory or at an off-site location.

  12. Potential particulate impacts at the Grand Canyon from northwestern Mexico.

    PubMed

    Eatough, D J; Green, M; Moran, W; Farber, R

    2001-08-10

    Project MOHAVE was a major air quality and visibility research program conducted from 1990 to 1999 to investigate the causes of visibility impairment in the Grand Canyon National Park region. At Meadview, a remote monitoring site just west of the Grand Canyon National Park, on September 1 and 2, 1992, the concentrations of sulfate (3.1 and 4.3 microg sulfate/m3) were the highest seen in 6 years of monitoring at this site. During this period, the concentrations of SO2 at Meadview were also abnormally high and approximately three times the sulfate concentrations, on a nmol/m3 basis. High concentrations of sulfate and SO2 extended south into southern Arizona and northwestern Mexico. Based on ambient atmospheric conditions, emissions from the Mohave Power Project (MPP) 110 km upwind of Meadview could not have been responsible for the majority of the regionally observed sulfur oxides. The geographical distribution of SO2 and sulfate, and available source information suggest that northwestern Mexico was a significant source of the unusually high observed sulfur oxides. A CMB model developed during Project MOHAVE was used to apportion sulfur oxides at Meadview and other sampling sites throughout the study region for August 31-September 2, 1992. The results indicate that the contribution of MPP to sulfate at Meadview was typical. However, the transport of SOx from northwestern Mexico was elevated throughout much of the region during this time period. This led to the large increase in sulfate concentrations at Meadview on September 1 and 2. These results indicate that emissions from Mexico can be a significant source of particulate material in the Grand Canyon. PMID:11516140

  13. Effects of extreme meteorological conditions on coastal dynamics near a submarine canyon

    NASA Astrophysics Data System (ADS)

    Skliris, N.; Lacroix, G.; Djenidi, S.

    2004-06-01

    A 3-D hydrodynamic model is applied to assess shelf/slope exchanges in the Calvi Canyon region (Corsica, NW Mediterranean) during the violent storm that affected the Western Europe in December 1999. Simulations are carried out using high-frequency sampling meteorological data to take into account the short-term variability of the atmospheric conditions. It is shown that the combined effects of canyon topography and of the wind forcing during the storm are responsible for a large increase of both cross-shore and vertical transports in the area. Strong downwelling motion is simulated all along the continental slope with vertical velocities up to 2 cm s -1 within the canyon. High turbulent diffusion levels are obtained leading to the complete mixing of the water column within the canyon. Results suggest that increased turbulent diffusion and downwelling circulation in the canyon during the storm should result in a large transport of coastal water towards the abyssal plain.

  14. Factors affecting condition of flannelmouth suckers in the Colorado River, Grand Canyon, Arizona

    USGS Publications Warehouse

    Paukert, C.; Rogers, R.S.

    2004-01-01

    The impoundment of the Colorado River by Glen Canyon Dam, Arizona, in 1963 created a highly regulated environment in the Grand Canyon that altered the native fish populations, including the flannelmouth sucker Catostomus latipinnis. Flannelmouth suckers were sampled from 1991 to 2001 to determine seasonal, annual, and spatial trends in fish condition (i.e., relative weight [Wr]). Mean Wr peaked during the prespawn and spawning periods and was lowest in summer and fall, but it was never lower than 93. Condition was variable throughout the Grand Canyon but was typically greatest at intermediate distances from Glen Canyon Dam, possibly because of the increased number of warmwater tributaries in this reach. Flannelmouth sucker condition in September was positively correlated with Glen Canyon Dam discharge during summer (June-August); this result may be due to the larger euphotic zone and greater macroinvertebrate abundance observed during higher water flows. Increased dam discharge that stimulates river productivity may provide benefits for this native fish.

  15. A look at Bacon Flat, Grant Canyon oil fields of Railroad Valley, Nevada

    SciTech Connect

    Johnson, E.H. )

    1993-05-17

    The prolific wells at Grant Canyon, and the puzzling geology, have intrigued explorationists and promoters. Many a Nevada prospect has been touted as 'another Grand Canyon.' But what processes formed Grant Canyon, and can others be found Last August, Equitable Resources Energy Co,'s Balcron Oil Division spudded a well at Bacon Flat, a mile west of Grant Canyon. A one well field, Bacon Flat had been abandoned in 1988. But just 900 ft north of the field opener, Balcron's well tested oil at a rate or 5,400 b/d. It turns out that Bacon Flat and Grant Canyon fields have a common geological history and, in fact, share the same faulted horst. However, they formed by an unusual combination of events that may be unique to those fields. This paper describes the geologic history, well logging interpretations, structures, the Jebco C seismic line, a geologic cross section, and the author's conclusions.

  16. Comparing the Grand Canyon of the East to the Western one

    NASA Astrophysics Data System (ADS)

    Gorom, J.; Martinez-Hackert, B.

    2007-12-01

    The Grand Canyon of the West (GCW) is an internationally well-known geological world wonder of the South Western United States' Colorado Plateau. The Grand Canyon of the East is a similarly beautiful, less well-known, smaller canyon in the Devonian/Silurian sedimentary rocks of the western part of New York State in the Eastern United States. For the purpose of creating a comparative database to be used in the field, classroom and public education settings, features of New York's canyon, better known as Letchworth State Park (LSP) to Arizona's canyon, were collected, obtained, and recorded. We compared various numbers on rock formations, ages of the units, stream volume, and depth and age of canyon formation, erosion processes and other interesting geological features between the two canyons. The sedimentary rocks of both canyons tell the story of the conditions under which the rocks were laid onto the Earth's surface at the time. This study includes an evaluation of how the two canyons have formed including features we see in the strata. Literature research revealed that LSP is on the order of 10 times smaller than the Grand Canyon in various aspects. Genesee river is up to only 4 m deep while the Colorado River reaches depths of up to 30 m. The Genesee extends 25.3 km within its canyon, paling at the majestic 445.79km of the Colorado within its canyon. The depths of the two canyons also show how small LSP is in comparison to the GCW Letchworth canyon's depth is 0.17 km while GCW is 1.61 km. The width of LSP's canyon is 0.1 km while the Grand Canyons' is 28.97 km at their widest locations. Fieldwork in both canyons allowed for some comparison of the natural waterfall features within the canyons. With help from a laser range finder measurements were taken from the most prominent waterfalls of LSP and the Havasu creek. Rock formations were compared. While the periods of Precambrian to the middle Permian time are found in the GCW, the Silurian/Devonian formations are missing at the GCW. On the other hand, during this period of time, a warm shallow sea was present in WNY, as its shoreline transgressed and regressed over the land, it deposited the Silurian/Devonian rocks we see today. This study contains helpful information about geology, past life, and past environments of the two areas. LSP is often used as a field trip location of Western New York's geology educators having in mind similarities to the much further away Grand Canyon. However, even though it's nickname suggest a promising comparison, LSP turns out to be a beautiful yet tiny baby brother of the Grand Canyon of the West, both in size and age.

  17. 20140701-0731_Green Machine Florida Canyon Hourly Data

    SciTech Connect

    Thibedeau, Joe

    2014-07-31

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 01 July to 31 July 2014.

  18. 20140501-0531_Green Machine Florida Canyon Hourly Data

    SciTech Connect

    Thibedeau, Joe

    2014-06-02

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 01 May to 31 May 2014.

  19. 20140201-0228_Green Machine Florida Canyon Hourly Data

    DOE Data Explorer

    Thibedeau, Joe

    2014-03-03

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 01 Feb to 28 Feb 2014.

  20. 20131001-1031_Green Machine Florida Canyon Hourly Data

    DOE Data Explorer

    Thibedeau, Joe

    2013-11-05

    Employing innovative product developments to demonstrate financial and technical viability of producing electricity from low temperature geothermal fluids, coproduced in a mining operation, by employing ElectraTherm's modular and mobile heat-to-power "micro geothermal" power plant with output capacity expected in the 30-70kWe range. The Green Machine is an Organic Rankine Cycle power plant. The Florida Canyon machine is powered by geothermal brine with air cooled condensing. The data provided is an hourly summary from 1 Oct 2013 to 31 Oct 2013.