Science.gov

Sample records for valles marineris canyon

  1. Western Candor Chasma, Valles Marineris

    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

  2. Valles Marineris Landforms

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 20 August 2003

    The steep canyon walls and ridge forming layers of Valles Marineris are on display in this THEMIS picture. Landslides and gullies observed throughout the image are evidence to the continued mass wasting of the martian surface. Upon close examination of the canyon floor, small ripples that are likely migrating sand dunes are seen on the surface. Some slopes also display an interesting raked-like appearance that may be due to a combination of aeolian and gully forming processes.

    Image information: VIS instrument. Latitude -7.4, Longitude 274.2 East (85.8 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. 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

  4. Lakes in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Lucchitta, Baerbel K.

    2010-10-01

    The paper reviews the evolution of hypotheses of lakes in Valles Marineris through observations made from the time of Mariner and continuing through the Viking, MGS, MO, MEx, and MRO missions. Several pertinent findings from these missions are addressed, including: The morphology and composition of the interior layered deposits (ILD); the question whether ILD are deposited inside the troughs or exhumed from the walls; the possible existence of ancestral basins; the derivation of water; arguments for an origin as aqueous, eolian, or pyroclastic sediments, or sub/ice volcanoes; origin of inclined layers, mounds and moats; and age relations of features within and peripheral to the troughs. A possible scenario begins with the collapse of ice-charged ground into ancestral basins along structural planes of weakness due to Tharsis stresses, about 3.5 Ga ago. The basins rapidly filled with water from ground ice, subterranean aquifers, or nearby valley networks. The water spilled out of the peripheral troughs and flowed across high plateaus into early outflow channels. The ancestral basins then filled with sediments derived from valley networks or from trapped eolian or pyroclastic deposits. Alternatively, volcanoes rose under the water or ice to form tuyas. The water was highly acidic, and sediments may have been deposited directly as evaporites or were later altered to evaporites by the brines or by hydrothermal activity. Percolating fluids produced iron oxide concretions. Similar alteration would have affected the putative volcanoes. Most of the ILD were emplaced early in the troughs' history. Shortly thereafter, more water erupted from the peripheral troughs and formed additional chaos and outflow channels. The ancestral basins were breached by erosion and tectonism, and the through-going Coprates/Ius graben system developed. Major lakes within the Valles Marineris dried up and vigorous wind erosion reduced the friable, evaporite-rich sediments to isolated mounds

  5. Valles Marineris - with 3D

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    The top half of this THEMIS visible image shows interior layered deposits that have long been recognized in Valles Marineris. Upon close examination, the layers appear to be eroding differently, indicating different levels of competency. This, in turn, may be interpreted to indicate different materials, and/or depositional processes. At the bottom of the image, materials eroded from the walls of the canyon form dunes and other aeolian bedforms.

    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.

    Image information: VIS instrument. Latitude -6.5, Longitude 287.3 East (72.7 West). 19 meter/pixel resolution.

  6. 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.

  7. Erosional landforms on the layered terrains in Valles Marineris

    NASA Technical Reports Server (NTRS)

    Komatsu, G.; Strom, R. G.; Gulick, V. C.; Parker, T. J.

    1992-01-01

    Many investigators have proposed potential lakes in Valles Marineris based on the relationship with outflow channels, and a proposed lacustrine origin of layered deposits. We have investigated the erosional style of the layered terrains and evaluated their potential origins as sedimentation in and erosional modification by these lakes. The erosional features that will be discussed are distributed in the central canyon area and classified into terraces and layered depressions. Many terraces can be explained by coastal erosion in lakes as well as by eolian erosion. The lack of terraces on the canyon walls is probably due to more recent sapping and mass wasting of materials with different mechanical response to erosion than the layered terrains. Catastrophic water discharges in Valles Marineris as hypothesized by an ocean model may have been the source of the lakes and the eventual catastrophic release of water from the canyons.

  8. Valles Marineris Basin Beds: a Complex Story

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1985-01-01

    High resolution stereoimages of the central Valles Marineris enabled detailed geologic mapping on Ophir and Candor Chasmata. Abundant light colored deposits, both layered and massive, fill the chasmata in this region. Units within these deposits were identified by their erosional characteristics and superposition and cross cutting relations. The Valles Marineris beds reflect a history of repeated faulting, volcanic eruptions, and deposition and erosion, resulting in stratigraphic sequences with several unconformities. Because of the preponderance of apparent volcanic deposits inside the troughs, the chasmata may not be simple grabens, but rather giant volcano tectonic depressions. Major events in chasmata development are examined.

  9. A tectonic geomorphological classification of the walls of Valles Marineris

    NASA Technical Reports Server (NTRS)

    Spencer, J. R.

    1984-01-01

    Viking 1 imagery of the Coprates NW quadrangle was used in an attempt to develop a geomorphic classification scheme for the canyon walls of Valles Marineris analogous to that devised to evaluate the relative tectonic activity of terrestrial mountain fronts. The four classes of walls established are described and mapped. Regions where a class cannot be assigned owing to the presence of intra canyon sediments, landslides, or landslide debris; and apparent fault scarps that occur on the canyon floor rather than at the wall base are also shown. The most striking feature is the concentration of active tectonic features within lus Chasma, and to a lesser extent in Tithonium Chasma, as well as along the north walls of Coprates and East Candor.

  10. 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

  11. Stratigraphy of the layered terrain in Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Komatsu, G.; Strom, Roger G.

    1991-01-01

    The layered terrain in Valles Marineris provides information about its origin and the geologic history of this canyon system. Whether the terrain is sedimentary material deposited in a dry or lacustrine environment, or volcanic material related to the tectonics of the canyon is still controversial. However, recent studies of Gangis Layered Terrain suggests a cyclic sequence of deposition and erosion under episodic lacustrine conditions. The stratigraphic studies are extended to four other occurrences of layered terrains in Valles Marineris in an attempt to correlate and distinguish between depositional environments. The Juvantae Chasma, Hebes Chasma, Ophir and Candor Chasmata, Melas Chasma, and Gangis Layered Terrain were examined. Although there are broad similarities among the layered terrains, no two deposits are exactly alike. This suggests that there was no synchronized regional depositional processes to form all the layered deposits. However, the similar erosional style of the lower massive weakly bedded unit in Hebes, Gangis, and Ophir-Candor suggests it may have been deposited under similar circumstances.

  12. 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

  13. 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.

  14. Year 3 Geologic Mapping in Central Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Fortezzo, C. M.; Gullickson, A. L.; Rodriguez, J. A. P.; Platz, T.; Kumar, P. S.

    2016-06-01

    In year 3 we mapped the west side of central Valles Marineris, Mars. We split landslide orientations into typical terrestrial categories including flows, slides, spreads, and falls. We continued work on the ILD using bedding orientations and CRISM.

  15. Slope stability analysis of Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Vittorio De Blasio, Fabio; Battista Crosta, Giovanni; Castellanza, Riccardo; Utili, Stefano

    2013-04-01

    Valles Marineris (VM) in the equatorial area of Mars exhibits several gravitational failures which resulted in a series of large landslides up to several hundred cubic kilometers in volume. Questions arise as to forces at play and rock strength in the stability of the walls of VM. In this work we address the stability analysis of the walls of VM by considering the strength of the materials of the chasma walls and the causes of landslides. Using finite element calculations and the limit analysis upper bound method, we explore the range of cohesion and friction angle values associated to realistic failure geometries, and compare predictions with the classical Culmann's wedge model. Our analysis is based both on synthetic, simplified slope profiles and also on the real shape of the walls of VM taken from the MOLA topographic data. Validation of the calibrated cohesion and friction angle values is performed by comparing the computed unstable cross sectional areas with the observed pre- and post-failure profiles and estimated failure surface geometry. This offers a link between rock mass properties, slope geometry and volume of the observed failure. Pseudo-static seismic analyses generated another set of dimensionless charts. Our pseudo-static analyses show that low seismicity events induced by meteoroids impacts compatible with the size of craters could be a cause for some of the observed landslides if poor rock properties for VM is assumed.

  16. Mesoscale Modeling of Water Vapor and Dust in Valles Marineris: Atmospheric Influences on Recurring Slope Lineae.

    NASA Astrophysics Data System (ADS)

    Leung, C. W. S.; Rafkin, S. C.; McEwen, A. S.

    2015-12-01

    Extensive recurring slope lineae (RSL) activity has been detected in Valles Marineris on Mars and coincides with regions where water ice fogs appear [1]. The origin of the water driving RSL flow is not well understood, but observational evidence suggests atmospheric processes play a crucial role [2]. Provided the atmospheric vapor concentration is high enough, water ice fogs can form overnight if the surface temperature cools below the condensation temperature. Correlations between dust storms and flow rates suggest that atmospheric dust opacity, and its influence on air temperature, also has a significant effect on RSL activity. We investigate planetary boundary layer processes that govern the hydrological cycle and dust cycle on Mars using a mesoscale atmospheric model to simulate the distribution of water and dust with respect to regional atmospheric circulations. Our simulations in Valles Marineris show a curious temperature structure, where the inside of the canyon appears warmer relative to the plateaus immediately outside. For a well-mixed atmosphere, this temperature structure indicates that when the atmosphere inside the canyon is saturated and fog is present within Valles Marineris, fog and low-lying clouds should also be present on the cooler surrounding plateaus as well. However, images taken with the Mars Express High Resolution Stereo Camera (HRSC) show instances where water ice fog appeared exclusively inside the canyon. These results have important implications for the origin and concentration of water vapor in Valles Marineris, with possible connections to RSL. The potential temperatures from our simulations show a high level of stability inside the canyon produced dynamically by sinking air. However, afternoon updrafts along the canyon walls indicate that over time, water vapor within the chasm would escape along the sides of the canyon. Again, this suggests a local source or mechanism to concentrate water vapor is needed to explain the fog

  17. Evidence for ponding and catastrophic floods in central Valles Marineris, Mars

    USGS Publications Warehouse

    Harrison, K.P.; Chapman, M.G.

    2008-01-01

    The Valles Marineris canyon system of Mars is closely related to large flood channels, some of which emerge full born from chaotic terrain in canyon floors. Coprates Chasma, one of the largest Valles Marineris canyons, is connected at its west end to Melas Chasma and on its east end to chaotic terrain-filled Capri and Eos Chasmata. The area from central Melas to Eos Chasmata contains a 1500 km long and about 1 km deep depression in its floor. Despite the large volumes of groundwater that likely discharged from chaotic terrain in this depression, no evidence of related fluvial activity 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 Hesperian discharge of water possibly produced a lake (mean depth 842 m) spanning parts of the Valles Marineris depression (VMD). 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 (-3560 m). Simulated ponding in the VMD 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. ?? 2008 Elsevier Inc.

  18. Light-toned Layered Outcrops in Valles Marineris Walls

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site]

    Valles Marineris a system of troughs, chasms, and pit chains that stretches more than 4,000 km (2,500 miles) across the martian western hemisphere. Outcrops of layered material found in mounds and mesas within the chasms of the Valles Marineris were known from the pictures taken by Mariner 9 in 1972 and the Viking orbiters of 1976-1980. One example of the those known previously is the mesa labeled 'Candor Mensa' in the context image (above); another example is the mound in the center of Ganges Chasma. For several decades, it has been widely speculated among Mars scientists that the light- and dark-toned layered materials in the Valles Marineris might have formed in lakes that had once filled the chasms during the most recent epoch of martian history; others thought they might result from volcanic ash deposited in the chasms. Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images have confirmed the presence of light- and dark-toned layered sedimentary rock outcrops in the Valles Marineris, but they have also revealed many more than were previously known and they have shown several good examples that these materials are coming out of the walls of the Valles Marineris chasms. The fact that these materials come out of the chasm walls means that the layers do not represent lakes (or volcanic debris) that formed in the Valles Marineris. Instead, they represent materials deposited and buried long before there ever was a Valles Marineris. They are seen now because of the faulting and erosion that opened up and widened the Valles Marineris troughs. The context image is a mosaic of Viking 1 orbiter images taken in 1976 showing a portion of the wall that separates western Ophir Chasma from western Candor Chasma in the Valles Marineris. This area is located around 5oS, 74oW. The white box labeled 'M17-00467' shows the location of a subframe of MOC image M17-00467 that was acquired in July 2000 to allow scientists to

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

    NASA Astrophysics Data System (ADS)

    Dębniak, 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.

  20. Formation of the layered deposits in the Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Nedell, S. S.; Squyres, S. W.

    1987-01-01

    Evidence is presented for large standing bodies of water on Mars during past epochs. It is noted that the origin of the horizontally-layered deposits in the Valles Marineris can be best explained by formation in standing bodies of water. These lakes, if they existed, were most likely covered by ice. There are several geologically feasible mechanisms that could have led to formation to thick deposits in ice covered paleolakes in the Valles Marineris. Present data are insufficient to choose conclusively among the various possibilities.

  1. Recurring Slope Lineae in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    McEwen, A. S.; Dundas, C. M.; Byrne, S.; Mattson, S.; Ojha, L.; Schaefer, E.; Wray, J. J.

    2012-12-01

    Recurring slope lineae (RSL) are relatively low-albedo features up to a few m wide that extend down steep slopes from bedrock outcrops. Hundreds may form in rare locations, often associated with small channels. In the southern mid-latitudes, RSL appear and grow incrementally during the late southern spring through summer, and they favor equator-facing slopes--times and places with peak surface temperatures from ~250 to 300 K. RSL are recurring: they form and grow in the warm season, then fade and usually completely disappear in cold seasons. During the next warm season, similar but new features form and grow. For more, see McEwen et al., 2011, Science 333, 740. As of early 2012, 15 RSL sites had been confirmed between 52-32°S latitudes. Confirmation requires that we observe many new lineae forming at a site in more than one Mars year, distinguishing RSL from episodic dry mass wasting triggered by eolian, seismic, or impact activity. We have recently confirmed three sites in the equatorial region of Mars. Two of them are on the floor of Coprates Chasma and one is in central Valles Marineris, all near latitude 12S. They are on north-facing slopes and active in southern winter/northern summer (which may be the warmest season on these steep slopes, although in the southern hemisphere). The surface brightness temperatures from THEMIS remain in the range (>250 K) of the southern mid-latitude RSL sites when active, and the morphologies and geologic settings are also similar. We will continue monitoring these sites throughout the year, along with occasional monitoring of other candidate equatorial RSL sites. If RSL are due to flow of salty water, the equatorial sites may be of special interest for future exploration.

  2. Mars: New evidence for origin of some Valles Marineris layered deposits

    NASA Technical Reports Server (NTRS)

    Scott, David H.

    1993-01-01

    The discovery of layered deposits in the walls of a deep trough in Lunae Planum has implications for the origin of similar-appearing deposits in some canyons of Valles Marineris. Although layering is visible in the competent, cliff-forming upper walls of the canyons, the dissimilarity in appearance between canyon walls and soft rounded hills of layered deposits on canyon floors, as well as their contrasting patterns of erosion, has been considered strong evidence that their modes of origin were different. Most workers agree that the wall rocks are volcanic flows derived from fissure vents and other volcanic sources in the region. However, several hypotheses have been advanced to account for the softer-appearing stratified floor deposits. Chief among them is the proposal that the floor deposits are waterlaid sediments that accumulated in large lakes within the canyons and include materials eroded from canyon walls, eolian deposits, and subaqueous volcanic eruptives.

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

    NASA Technical Reports Server (NTRS)

    Nedell, Susan S.; Squyres, Steven W.; Andersen, David W.

    1987-01-01

    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.

  4. Cataloging Common Sedimentary and Deformation Features in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Urso, A.; Okubo, C. H.

    2015-12-01

    The sedimentary deposits in the Valles Marineris region of Mars are investigated to build a catalog of sedimentary and deformational features. The occurrence of these features provides new and important constraints on the origins of these sedimentary deposits and of their broader geologic histories. Regional surveys and mapping of these features is warranted given the plethora of recently acquired observations by the Mars Reconnaissance Orbiter. Select sedimentary and deformational features were identified using High Resolution Imaging Science Experiment (HiRISE) observations and stereo pairs, along with Context camera images. Feature locations were cataloged using Java Mission-planning and Analysis for Remote Sensing (JMARS) the geospatial information system. Images acquired in and around Hebes, Ophir, Tithonium, Candor, Ius, Melas and Coprates Chasmata were the focus of this investigation. Mass wasting processes, soft-sediment deformation structures, and fan-like deposits are known to occur in abundance across the Valles Marineris region. For this reason, the features recorded in this investigation were landslides, contorted bedding, injectites, putative mud volcanoes, faults, folds, and fan-shaped deposits. Landslides, faults, and fan-shaped deposits were found to be common occurrences, while contorted bedding, injectites, putative mud volcanoes, and folds occur less frequently and in clusters. The placement and frequency of these features hint at past tectonic and depositional processes at work in Valles Marineris. This catalogue of sedimentary and deformational features in the Valles Marineris region of Mars is being used to define targets for future HiRISE observations.

  5. 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

  6. 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.

  7. Flow-like features in Valles Marineris, Mars: Possible ice-driven creep processes

    NASA Astrophysics Data System (ADS)

    Rossi, A. P.; Komatsu, G.; Kargel, J. S.

    1999-09-01

    Recent high resolution MOC images have revealed the presence of deformed impact craters on flow-like features characterized by narrow bands of alternating light and dark material on the walls of Valles Marineris. The maximum crater elongations are consistent with the flow directions. Moreover the directions of these flows follow the topography downslope. In some cases, the flows emanate from cirque-like depressions, and the flows are divided by sharp ridges similar to arête. These landforms have resemblance to (1) alpine-type glacier morphology, including cirques, arêtes, and glaciers containing medial moraines; and (2) Grand Canyon-type sapping and mass wasting features. Certain aspects of the features in Valles Marineris seem more consistent with the first hypothesis involving a viscous rheology of the flows driven by ice-assisted creep processes. This hypothesis includes direct analogies to glaciers and rock glaciers. In the case of rock glaciers, flow is produced by freeze-thaw and by internal deformation of ice cores or lenses, whereas in the case of glaciers, movement occurs by internal deformation plus basal sliding in some cases where the glacier is melted at its bed. The amounts and roles of ice in the genesis of the Martian glacier-type landforms in Valles Marineris are not clear at this point. The population density of undeformed fresh impact craters on these flows appears to be low compared with the surrounding plateau areas. This may indicate relatively recent ages of the flow processes. Despite the limited coverage of the MOC images, the occurrence of the flow-like features associated by the deformed impact craters is common in most areas of Valles Marineris that have been imaged. We currently are working on the systematic survey of these flow-like features. We are also in the process of analyzing MOLA data in order to constrain the geometry of these landforms.

  8. 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

  9. 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.

  10. Interpretation of a Magnetic Map of the Valles Marineris Region, Mars

    NASA Technical Reports Server (NTRS)

    Purucker, M. E.; Langlais, B.; Mandea, M.

    2001-01-01

    A magnetic map of Valles Marineris is interpreted in terms of left-lateral faulting, the first evidence for substantial strike-slip faulting here. Surface exposures of highly magnetic material may exist in the walls of Valles Marineris. Additional information is contained in the original extended abstract.

  11. Modeling of Landslides in Valles Marineris, Mars, and Implications for Initiation Mechanism

    NASA Astrophysics Data System (ADS)

    Tsige, Meaza; Ruiz, Javier; del Río, Ian A.; Jiménez-Díaz, Alberto

    2016-06-01

    The Valles Marineris canyon system in Mars shows large landslides across its walls, which can be 40 km wide and up to 60 km long, with fall scarps height as high as 7 km. These landslides were produced through a large mass movement at high speed by gravity across the trough floor. Although the triggering factors are unclear, several mechanisms have been proposed as, among others, large amounts of subsurface water, quake produced through normal faulting close to the canyon walls, and meteoritic impacts. In this work we examine the limit equilibrium slope stability of three landslides (placed respectively at Ius, Candor, and Melas Chasmata), which can be considered representative, with the aims of constraining their formation conditions. Our results suggest that external factors (as high pore fluid pressure, seismic loading or rock mass disturbance) do not seem necessary for the failure of slopes if they are composed of unconsolidated materials, while high pore water pressure or ground acceleration are needed to trigger slides in slopes composed of strong basaltic-like materials. Moreover, the presence of sub-surface ice would contribute to slope stability. As a whole, our findings point to ground shaking due to meteorite impacts as the main triggering force for most landslides in the Valles Marineris.

  12. Modeling of Landslides in Valles Marineris, Mars, and Implications for Initiation Mechanism

    NASA Astrophysics Data System (ADS)

    Tsige, Meaza; Ruiz, Javier; del Río, Ian A.; Jiménez-Díaz, Alberto

    2016-04-01

    The Valles Marineris canyon system in Mars shows large landslides across its walls, which can be 40 km wide and up to 60 km long, with fall scarps height as high as 7 km. These landslides were produced through a large mass movement at high speed by gravity across the trough floor. Although the triggering factors are unclear, several mechanisms have been proposed as, among others, large amounts of subsurface water, quake produced through normal faulting close to the canyon walls, and meteoritic impacts. In this work we examine the limit equilibrium slope stability of three landslides (placed respectively at Ius, Candor, and Melas Chasmata), which can be considered representative, with the aims of constraining their formation conditions. Our results suggest that external factors (as high pore fluid pressure, seismic loading or rock mass disturbance) do not seem necessary for the failure of slopes if they are composed of unconsolidated materials, while high pore water pressure or ground acceleration are needed to trigger slides in slopes composed of strong basaltic-like materials. Moreover, the presence of sub-surface ice would contribute to slope stability. As a whole, our findings point to ground shaking due to meteorite impacts as the main triggering force for most landslides in the Valles Marineris.

  13. Discrete Element Modeling of Landslides in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Smart, K. J.; Hooper, D. M.; Sims, D. W.

    2010-12-01

    High-resolution MOC, THEMIS, HiRISE, and HRSC image data and geomorphologic characterization based on MOLA-derived topography are being used as input for discrete element modeling to simulate slope failure in Valles Marineris. Two landslides have been selected for detailed analysis. The first landslide, in Coprates Chasma, has a strongly arcuate and recessional 4-km-high main scarp, and a runout length of approximately 70 km to the opposing canyon wall. The landslide deposit or transported material has a hummocky topography. The second landslide, in Ganges Chasma, has a 3-4 km high main scarp, a complex rupture surface with a displaced block, and a runout length of approximately 25 km. The landslide deposit is characterized by longitudinal ridges and furrows. The main scarp and displaced material of a landslide provide insight into the mechanical nature of the surface and shallow subsurface of Mars. We use two-dimensional discrete element models oriented parallel with the slide direction to examine the effects of mechanical layering upon the morphology of slip surfaces, scarps, and transported deposits that form as a result of slope failure on Mars. The initial geometry of the models is designed to replicate the height and length of each study site and to capture the observed and interpreted mechanical stratigraphy. Discrete element particle diameters range from approximately 30-60 m; a compromise between model fidelity and computation time. Bond properties (i.e., bond stiffness and strength), which control the macroscale behavior, are adjusted between layers to produce variable mechanical stratigraphic configurations. Our models were conducted under Mars gravity (3.71 m/s2) using a pre-slide free surface that dips 60°. Model results show that an initial slip surface forms some distance from the lateral free surface and subsequently migrates away from the free surface in discrete increments producing a well-developed main scarp. The models also show rotated blocks

  14. 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.

  15. 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

  16. 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

  17. Implications of Flexural Flanks at the Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Anderson, F. S.; Banerdt, W. B.; Golombek, M. P.

    1999-01-01

    The presence or absence of flexural flanks at the Valles Marineris (VM), Mars, have strong implications for the properties of the lithosphere, information which is critical for models of compensation state and formation of the troughs. Two hypotheses are favored for the formation of the VM, tectonic extension or subsurface withdrawal potentially related to dike emplacement; in either case, the formation of the large troughs at the VM requires a flexural response. After discussing preliminary models of flexure for VM from released Mars Global Surveyor (MGS) Mars Orbiting Laser Altimeter (MOLA) topography, this abstract considers the implications of flexure for gravity modeling and the lithosphere at VM. With future MGS topography and gravity data, and constraints on T(sub e) from this study, significantly better gravity modeling can be done to understand the state of the lithosphere at VM. Additional information is contained in the original extended abstract.

  18. New insights into the hydrologic history of western Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. A. P.; Gulick, V. C.

    2013-09-01

    Using Mars Reconnaissance Orbiter (MRO) Context (CTX) and High Resolution Imaging Science Experiment (HiRISE) image data in tandem with Mars Orbiter Laser Altimeter (MOLA) surface topography, we have characterized and mapped the remnants of an extensive flow feature that we interpret to be a debris flow within the floors of Tithonium Chasma and an adjacent canyon system in western Valles Marineris. The deposit appears highly modified by collapse and tectonic deformation consistent with a freezing and devolatization history, but shows no signs of resurfacing by catastrophic floods. Preliminary impact crater count statistics indicate the deposit was emplaced during the Early Hesperian, thereby defining a stratigraphic marker that constrains any major surface water discharges from Noctis Labyrinthus to the Noachian period.

  19. Fogs and Clouds are a Potential Indicator of a Local Water Source in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Leung, Cecilia W. S.; Rafkin, Scot C. R.; Stillman, David E.; McEwen, Alfred S.

    2016-04-01

    Recurring slope lineae (RSL) are narrow, low-albedo seasonal flow features on present-day Mars that extend incrementally down warm, steep slopes, fade when inactive, and reappear annually over multiple Mars years [1,2]. Hypothesis for the sources of volatile by which RSL are recharged include seeping water, melting shallow ice, aquifers, and vapor from the atmosphere [1-5]. About 50% of the 250+ candidate and confirmed RSL sites appear in and around Valles Marineris [3], and coincide with regions where putative morning water ice fogs may appear as imaged by the High Resolution Stereo Camera on Mars Express [6]. The presence of fog may provide clues to the water cycle within the canyon, and could elucidate the processes related to the evolution of RSL. Using a regional atmospheric model, we investigate the atmospheric dynamics in and around Valles Marineris. Our simulation results show a curious temperature structure, where the inside of the canyon appears warmer relative to the plateaus immediately outside at all times of day. Formation of fogs requires the atmosphere to be saturated. This can happen with the appropriate combination of cooling or addition of water vapor. The modeled temperature structure suggests that if water is well mixed and fog is present within the warmer canyon bottom, fog should be present on the cooler surrounding plateaus as well. This is generally not the case. Therefore, the only way to produce fog inside the canyon is to have a local water source. RSL may contribute to this atmospheric water through evaporation, or RSL may simply be a surface marker of a larger near-surface reservoir of water that can act as a source. From the modeled temperatures, we calculated the corresponding saturation vapor pressures and saturation mixing ratios to determine the amount of water vapor in the air at saturation. The observed Martian atmospheric column abundance is ~10 precipitable microns on average [7] and presents a major challenge for an

  20. 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

    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.

  1. 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.

  2. The Interior Layered Deposits of Valles Marineris: Layering, Erosional Processes, and Age Relationships

    NASA Technical Reports Server (NTRS)

    Weitz, C. M.; Parker, T.; Anderson, F. S.; Grant, J. A.

    2001-01-01

    We have used Viking and Mars Global Surveyor data to study the interior layered deposits in detail. We have identified features which may support fluvial activity within Valles Marineris. Stratigraphic relationships indicate the deposits are younger than the wallrock. Additional information is contained in the original extended abstract.

  3. 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

  4. On the Morphology and Transition of Valles Marineris Landforms: Rock Glaciers/Protalus Lobes vs. Landslides

    NASA Astrophysics Data System (ADS)

    van Gasselt, S.; Hauber, E.; Dumke, A.; Schreiner, B.; Neukum, G.

    2009-04-01

    The Valles Marineris canyon system exhibits a variety of different landforms associated with landslide mechanisms, ranging from several tens of meters to kilometers in length. They usually cover a surface of 1000 km2 and have an average volume of up to 5000 km3 [1-2]. It is assumed that they have been emplaced under wet as well as dry conditions from destabilized wall-rock and from surrounding sapping valleys [e.g., 1-3]. Absolute age determinations have furthermore shown that landslides in Valles Marineris span much of Martian history with ages as young as 50 Myr up to 3.5 Gyr [1]. Notwithstanding their individual ages and timespan during which they have been emplaced, landslides seem to have formed repetitively producing comparable morphologies and do not show substantial modifications throughout the last 3.5 Gy [1]. We here put our focus on a set of complex tongue-shaped landforms situated in the central parts of Valles Marineris at 283 °E, 8 °S which were previously identified as a single feature and for which a possible rock-glacier origin had been proposed [5]. This assumption implies environmental conditions which are not met today at such latitudes near the equator and which would contradict all observations related to the distribution of periglacial landforms on Mars, such as thermal contraction polygons, thermokarst features, and -- especially — lobate debris aprons [e.g., 6-11] which are considered to be Martian analogues for terrestrial rock glaciers. On the basis of our observations we come to the conclusion that the landforms discussed herein form a complex set of landslides derived from wall-rock sliding and/or from surrounding valleys. Consequently, different sources areas are reflected by the complexity of the landslides with several overlapping lobes and individual tongue-shaped features. Although the tongue-shaped morphology is characteristic of rock-glacier landforms, the assembly of furrows and ridges strongly suggests an origin caused by

  5. The Seasonal Behavior of Water Ice Clouds in the Tharsis and Valles Marineris Regions of Mars: Mars Orbiter Camera Observations

    NASA Technical Reports Server (NTRS)

    Benson, J. L.; Bonev, B. P.; James, P. B.; Shan, K. J.; Cantor, B. A.; Caplinger, M. A.

    2003-01-01

    The Mars Orbiter Camera (MOC) was used to obtain global maps of the Martian surface. The maps used were acquired between March 15, 1999 (LS = 110 ) and July 31, 2001 (L(sub s) = 110), corresponding to approximately one and a quarter martian years. In this work we focused on water ice clouds associated with the surface features of Olympus Mons, Ascraeus Mons, Pavonis Mons, Arsia Mons, Alba Patera, and the Valles Marineris canyon system. Using these data, we have made three types of quantitative measurements to characterize the cloud activity: 1) cloud area and location, 2) cloud height, and 3) cloud optical depth. We have also searched for short period variations in the cloud areas.

  6. Layering in the wall rock of Valles Marineris: intrusive and extrusive magmatism

    NASA Astrophysics Data System (ADS)

    Williams, Jean-Pierre; Paige, David A.; Manning, Craig E.

    2003-06-01

    High-resolution images of the walls exposed in Valles Marineris reveal variations in appearance and degree of layering indicating various lithologies comprise the Tharsis plateau. The layered wall rock has been proposed to result from effusive flood basalt volcanism or interbedded sediments and volcanics. We present observations of unlayered rock that indicate layering extends to a greater depth in the western half of Valles Marineris and is confined to the Tharsis plateau, a region of thickened, uplifted crust resulting from prolonged intrusive activity. Consistent with this view, we propose that the observed layering may be a manifestation of intrusive rocks resulting from crystal fractionation of intruded basaltic magmas. Terrestrial layered plutons provide analogs for comparison such as those of the North Atlantic Igneous Province (NAIP) a large igneous province associated with crustal rifting and exposures of thick sequences of layered flood basalts and intruded layered cumulates.

  7. Strike-slip faulting of ridged plains near Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Schultz, Richard A.

    1989-01-01

    This paper identifies and documents several well-preserved examples of Martian strike-slip faults and examines their relationships to wrinkle-ridges. The strike-slip faulting predates or overlaps periods of wrinkle-ridge growth southeast of Valles Marineris, and some wrinkle ridges may have nucleated and grown as a result of strike-slip displacements along the echelon fault arrays. Lateral displacements of several km inferred along these arrays may be related to tectonism in Tharsis.

  8. A network of lava tubes as the origin of Labyrinthus Noctis and Valles Marineris on Mars

    NASA Astrophysics Data System (ADS)

    Leone, Giovanni

    2014-05-01

    The role of lava tube networks and lava channels is reassessed as the primordial stage of the volcano-erosional processes that formed the Labyrinthus Noctis-Valles Marineris system instead of a tectonic origin. The combined use of CTX, CRISM, HiRISE imagery, and MOLA profiles has provided valuable insight in the evolution of pit chains into fossae first and then chasmata later due to mass wasting processes caused by the erosional effect of the lava flows that draped Valles Marineris and other outflow channels. Although a quantitative evaluation of eruption rates is difficult even with digital terrain models (DTMs) because of the mixing between new flows and paleoflows, a comparison with Elysium and other Tharsis outflow channels suggests that the availability of lava supply is correlated to their widths. The images of ubiquitous lava flows rather than sporadic light-toned deposits strengthen the role of lava over that of water in the erosional processes that formed Labyrinthus Noctis and carved Valles Marineris like many other outflow channel on Mars. The erosional evolution of the outflow channels shows an increasing trend of age and a decreasing trend of depth from the sources on Tharsis to the mouths at Chryse Planitia. This finding, coupled with the observation of lava flows mantling Chryse Planitia, may have profound implications for the water inventories thought to have filled the lowlands with an ocean.

  9. 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

  10. Paleolake Deposits in Central Valles Marineris: A Unique Opportunity for 2001

    NASA Astrophysics Data System (ADS)

    Murray, Bruce

    1999-06-01

    Paleolake deposits have been mapped in Central Valles Marineris since Manner 9 and Viking. Accordingly, the region has been proposed as a priority target for landed payloads intended to detect diagnostic mineral evidence of a permanent lake environment, and, especially, biogenic signatures that could have survived from such promising candidate Martian habitats. Just-released MOLA data strongly buttress the hydrological case for long duration ice-covered lakes there during Hesperian times at least. And terrestrial discoveries within the last decade have extended the known subsurface distribution and seemingly ancient character of terrestrial chemotrophic microbes. These results, combined with the ground-water biogenic signature inferred by some from the Allen Hills meteorite, have strengthened significantly the scientific case for Central Valles Marineris. Until now, the difficulty has been the absence of a technical means within the Surveyor or New Millenium DS-2 capabilities for landing upon outcrops of interior layered deposits. Now the improved 2001 lander design brings exposures of interior paleolake deposits within the Surveyor program targeting capability for the first time. It is my purpose to argue here that several candidate paleolake deposits within the Central Vallis Marineris should be included as candidate landing sites pending definitive high-resolution MGS and Surveyor'98 observations.

  11. 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

  12. The influence of the topography on landslide's mobility in Valles Marineris (Mars), by a numerical & remote sensing approach

    NASA Astrophysics Data System (ADS)

    Lucas, A.; Mangeney, A.

    . Nevertheless, the taking into account of the topography does not explain the total differences between experiments and martians landslides. Our simulations show also that the mobility of martians landslides is larger than the mobility observed in dry granular flows experiments (one order of magnitude larger) [7] but still remains under sur-satured sub-marines landslides (one order of magnitude less) [8]. Those results show that it is needed to introduce another physical process to explain such mobility. The results do not allow to conclude about the role of water in the martians landslide dynamics. We propose that degazing processes causing by CO2 or sublimation of icy lenses in the ground would imply an increasing of mobility during slide events at Amazonian. A geological study using mineralogy given by OMEGA/MeX and Radar profile given by MARSIS/MeX would help to subjugate our preliminary results. References [1] B. K. Lucchitta. Landslides in Valles Marineris, Mars. Journal of Geoph. Research, 84:8097-8113, December 1979. [2] A. S. McEwen. Mobility of large rock avalanches : Evidence from Valles Marines, Mars. Geology, pages 1111-1114, 1989. [3] C. Quantin, P. Allemand, and C. Delacourt. Morphology and geometry of Valles Marineris landslides. Planetary and Space Sciences, 52:1011-1022, September 2004. [4] C. Quantin, P. Allemand, N. Mangold, and C. Delacourt. Ages of Valles Marineris (Mars) landslides and implications for canyon history. Icarus, 172:555- 572, December 2004. [5] E. Lajeunesse, A. Mangeney-Castelnau, and J. P. Vilotte. Spreading of a granular mass on a horizontal plane. Physics of Fluids, 16:2371-2381, July 2004. [6] A. Mangeney-Castelnau, F. Bouchut, J. P. Vilotte, E. Lajeunesse, A. Aubertin, and M. Pirulli. On the use of Saint Venant equations to simulate the spreading of a granular mass. Journal of Geophysical Research (Solid Earth), 110:9103- +, September 2005. [7] E. Lajeunesse, C. Quantin, P. Allemand, and C. Delacourt. New insights on the runout of

  13. New Evidence for the Origin of Layered Deposits in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Murchie, S.; Seelos, F.; Roach, L.; Mustard, J.; Milliken, R.; Arvidson, R.; Wiseman, S.; Lichtenberg, K.; Andrews-Hanna, J.; Bibring, J.; Bishop, J.; Parente, M.; Morris, R.

    2008-12-01

    Results from CRISM, HiRISE, and CTX on MRO provide new insights into the origin of interior layered deposits (ILDs) in Valles Marineris. A well-exposed, thick sequence in western Candor Chasma has spectral properties consistent with basaltic sand mixed with nanophase iron oxide-rich dust, with the addition of sulfates and crystalline ferric oxides. Most of the deposit is dominated spectrally by the dust component. Monohydrated and polyhydrated sulfates are concentrated in separate, interbedded layers, which in some cases are traceable over tens of kilometers. Monhydrated sulfates dominate the lower part of the deposits whereas polyhydrated sulfates are more common in upper strata. The deposits are partially mantled by low- albedo eolian ripples that contain pyroxenes similar in composition to what is found on the surrounding plateau, plus sulfates predominantly in monohydrated form. The dark ripples originate from discrete, friable layers. Similar dark, erodible layers elsewhere on Mars have been interpreted as buried eolian sand. Crystalline ferric oxides are concentrated in the sulfate-rich layers, and mass wasting has accumulated them at the base of steep slopes to form the deposits of gray hematite detected by TES. The persistence of monohydrated sulfates in debris shows that alteration of monohydrated to polyhydrated sulfates, proposed as an important weathering process, takes long compared to formation of the thin layer that dominates reflectance properties. The observed stratification of sulfate compositions implies differences in the abundance of liquid water or brine chemistry during deposition or early chemical modification of sediments. Inferred mineralogy and compositional stratification are similar to what is observed in sulfate-rich sediments in the Meridiani and Aram Chaos regions. The Meridiani deposits were proposed to accumulate where evaporites formed in areas of groundwater discharge and cemented eolian sediments, in which coarse- grained

  14. Inferring the high velocity of landslides in Valles Marineris on Mars from morphological analysis

    NASA Astrophysics Data System (ADS)

    Mazzanti, Paolo; De Blasio, Fabio Vittorio; Di Bastiano, Camilla; Bozzano, Francesca

    2016-01-01

    The flow characteristics and velocities of three landslides in Valles Marineris on Mars are investigated using detailed morphological analyses of high-resolution images and dynamical calculations based on the run-up and curvature of the landslide deposits. The morphologies of the landslides are described, especially concerning those characteristics that can provide information on the dynamics and velocity. The long runout and estimated high velocities, often exceeding 100 m/s, confirm a low basal friction experienced by these landslides. Because subaqueous landslides on Earth exhibit reduced friction, we explore the scenario of sub-lacustrine failures, but find little support to this hypothesis. The environmental conditions that better explain the low friction and the presence of longitudinal furrows suggest an aerial environment with a basal soft and naturally lubricating medium on which friction diminished gradually; in this perspective, ice is the most promising candidate.

  15. 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.

  16. Stratigraphy and erosional landforms of layered deposits in Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Satellite imagery is used to identify stratigraphy and erosional landforms of 13 layered deposits in the Valles Marineris region of Mars (occurring, specifically, in Gangis, Juventae, Hebes, Ophir-Candor, Melas, and Capri-Eos Chasmata), based on albedo and erosional styles. Results of stratigraphic correlations show that the stratigraphy of layered deposits in the Hebes, Juventae, and Gangis Chasmata are not well correlated, indicating that at least these chasmata had isolated depositional environments resulting in different stratigraphic sequences. On the other hand, the layered deposits in Ophir-Candor and Melas Chasmata appear to have been connected in each chasma. Some of the layered deposits display complexities which indicate changes in space and time in the dominant source materials.

  17. Extensive surface pedogenic alteration of the Martian Noachian crust suggested by plateau phyllosilicates around Valles Marineris

    NASA Astrophysics Data System (ADS)

    Le Deit, Laetitia; Flahaut, Jessica; Quantin, Cathy; Hauber, Ernst; Mège, Daniel; Bourgeois, Olivier; Gurgurewicz, Joanna; Massé, Marion; Jaumann, R.

    2012-03-01

    Thousands of phyllosilicate-rich outcrops, mainly iron or magnesium-rich are exposed on Noachian terrains in the Martian southern highlands. We analyzed 90 CRISM observations and more than a hundred HiRISE images located on the plateaus surrounding Valles Marineris. We mapped an extensive Al- and Fe/Mg-phyllosilicate-rich formation covering at least ˜197,000 km2, for which we introduce the name “Plateau Phyllosilicates.” Tens of meters in thickness, this light-toned formation crops out at various elevations on top of the Noachian units Npl1 and Npl2, as flat exposures on plateaus and along scarps such as valley walls, chasma walls, pit walls and impact crater rims. The Fe/Mg-phyllosilicate-rich lower member of the formation is composed of Fe/Mg-smectites (nontronite, saponite) and vermiculite. The Al-phyllosilicate-rich upper member of the formation contains Al-smectites (montmorillonite, beidellite) and locally kaolinite and/or halloysite. We suggest that the Plateau Phyllosilicates were mainly formed by pedogenesis related to the weathering of the Noachian bedrock by percolation of meteoric water or melted snow under a temperate and subarid climate during the Noachian Epoch in an alkaline to neutral environment. Kaolinite and/or halloysite may have formed in areas of more intense drainage at the surface under slightly acidic environments during the Noachian and Hesperian Epochs. Fluvial activity and deuteric alteration may have locally contributed to the genesis of phyllosilicates. This study suggests that the alteration of the Noachian basement of the plateaus surrounding Valles Marineris was widespread during the Noachian Epoch, and was still active during the Hesperian Epoch even though the water availability was limited.

  18. Mechanical conditions and modes of paraglacial deep-seated gravitational spreading in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Makowska, Magdalena; Mège, Daniel; Gueydan, Frédéric; Chéry, Jean

    2016-09-01

    Deep-seated gravitational spreading (DSGS) affects the slopes of formerly glaciated mountain ridges. On Mars, DSGS has played a key role in shaping the landforms of the giant Valles Marineris troughs. Though less spectacular, DSGS is common in terrestrial orogens, where understanding its mechanics is critical in the light of the ongoing climate change because it is a potential source of catastrophic landslides in deglaciated valleys. We conducted parametric numerical studies in order to identify important factors responsible for DSGS initiation. DSGS models are computed using an elastoviscoplastic finite element code. Using ADELI's software, we reproduce topographic ridge spreading under the effect of valley unloading. Two types of spreading topographic ridges are investigated, homogeneous or with horizontal rheological layering. We find that gravitational instabilities are enhanced by high slopes, which increase gravitational stress, and low friction and cohesion, which decrease yield stress. In the unlayered ridge, instability is triggered by glacial unloading with plastic strain concentration inside the ridge and at the base of the high slopes. Vertical fractures develop in the upper part of the slope, potentially leading to fault scarps. Ridge homogeneity promotes a deformation mode controlled by uphill-facing normal faulting and basal bulging. In the second case, the ridge encompasses horizontal geological discontinuities that induce rock mass anisotropy. Discontinuity located at the base of the slope accumulates plastic strain, leading to the formation of a sliding plane evolving into a landslide. The presence of a weak layer at ridge base therefore promotes another slope deformation mode ending up with catastrophic failure. Mechanical conditions and slope height being equal, these conclusions can probably be extrapolated to Earth. Compared with Mars, DSGS on Earth is inhibited because terrestrial topographic gradients are lower than in Valles Marineris, an

  19. 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

  20. Valles Marineris Dune Fields as Seen From the HiRISE, CTX and THEMIS Cameras

    NASA Astrophysics Data System (ADS)

    Chojnacki, M.; Moersch, J. E.

    2008-12-01

    Dune fields on Mars offer an opportunity to investigate the nature of eroded sediments and their interactions with the atmosphere. We examined 20 dune fields in Valles Marineris (VM) from the Mars Global Digital Dune Database [Hayward et al., 2007] to identify significant trends in composition, thermophysical properties, morphology and origin. Dune fields were examined in terms of: slopes, albedo, dust index, thermal inertia and the corresponding derived particle size. We have used image data from the Mars Reconnaissance Orbiter (MRO) instruments CTX [McEwen et al., 2006] and HiRISE [Malin et al., 2007] to establish geologic context for the dune fields, and in particular, to examine their relationships to neighboring geologic units. In general, VM dune fields display greater topographic relief and closer proximity to their inferred source regions than is typical for dune fields elsewhere on Mars. These dunes have a relatively high TES-derived thermal inertia mean value (394 Jm-2K-1 s-1/2, units hereafter assumed), which corresponds to ~1000 μm grains [Pelkey et al., 2001] or very coarse sand sizes. In contrast, typical non-VM dunes have a lower thermal inertia value of ~250, corresponding to ~350 μm grains. To investigate this more closely, high-resolution THEMIS-derived thermal inertia maps were created [Putzig et al., 2004]. CTX and HiRISE visible images revealed that bedrock outcrops are commonly found within dune fields, erroneously elevating the TES thermal inertia values over the ~3x5-km TES footprint. However, even after excluding intra-dune outcrop areas using higher-resolution THEMIS data, several VM dune fields have anomalously high thermal inertia values (>500) compared with non-VM dune fields. It is possible that the high thermal inertia values are indicative of indurated (fossilized) dune surfaces, rather than large individual grain sizes. Coprates Chasma contains a concentration of 6 dune fields both within the main chasm and in depressions to the

  1. Geomorphological characteristics of the interior layered deposits (ILDs) of Melas Chasma, central Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Harrison, Samantha; Quantin-Nataf, Cathy

    2013-04-01

    Stretching almost 600 km in width, Melas Chasma is located in the central part of the Valles Marineris (VM) and is one of the lowest lying of the chasmata. Spectral mapping of this chasma, particularly using MEX's OMEGA instrument, has revealed a strong presence of water-altered minerals (roughly a quarter of all such detected minerals to date in the VM; Chojnacki & Hynek, 2008), in the form of monohydrated and polyhydrated sulphates. Most of the sulphate-bearing rocks in Melas are found in association with thinly layered deposits, occurring in outcrops on the chasma floor. So-called interior layered deposits (ILDs) throughout the Valles Marineris have been the subject of considerable recent research, particularly for their association with these water-altered minerals. Better understanding of the origin and evolution of these ILDs may help to shed more light on the past climatic conditions on Mars and the potentially complicated history of liquid water on the planet. Relatively little geomorphological study of the ILDs of Melas Chasma has been conducted to date with regard to the differing characteristics of the different sulphate-bearing rocks. For instance, areas corresponding to polyhydrated sulphates in the Melas ILDs show considerable different surface textures to those corresponding to monohydrated sulphates. Interestingly, the latter show some surface textures comparable to the wind eroded, yardang bearing surfaces of the Medusae Fossae Formation, located roughly 4000 km to the west on the opposite side of the Tharsis volcanic province. This aim of this work, conducted as part of the European Research Council supported eMars project, is to compile a thorough geomorphological survey of the Melas Chasma ILDs and, through this, construct workable hypotheses regarding their origin and evolution and the context of their water-altered mineral content. Furthermore, to contrast and compare the ILDs of Melas with other large-scale deposits, such as the Medusae

  2. MGS/TES-Odyssey/THEMIS-IR Analysis of Localized Low Albedo Regions in Valles Marineris

    NASA Technical Reports Server (NTRS)

    NoeDobrea, E. Z.; Bell, J. F., III; Wolff, M. J.; Snook, K. J.

    2003-01-01

    We are conducting a systematic analysis of small (approximately 10's of km), localized regions in Valles Marineris that display significant albedo differences relative to their surroundings. This analysis is based on a finding that the locations of the hematite deposits identified by [1] in the interior layered deposits of Valles Marineris typically coincide with regions having a low MGS/TES visible bolometric albedo [1,2]. Until recently, it was difficult to identify the morphology or geologic context of the regions containing the hematite deposits. However, with the recent advent of high-resolution (1/128 /pixel) MOLA grided topography and Mars Odyssey s THEMIS-IR instrument, it has been possible to better understand the morphologic context of TES observations. This analysis combines the use of PDS-released data from the MGS/TES visible bolometer and infrared spectrometer, the Odyssey/THEMIS Infrared imager, and MOLA grided topography. First, the TES infrared bolometer is used to identify regions of interesting albedo variability, and is overlaid on Viking controlled photomosaics for context. THEMIS-IR data, in conjunction with MOLA topography, is then used to: 1) identify the context and morphology of the area; and 2) identify spectrally unique regions at the km scale. In preparation for the latter, all the THEMIS planes are coregistered using an autocorrelation routine, the data are converted to brightness temperature and then each plane is normalized to the brightness temperature of the third plane (1261 cm-1). We then perform a 3-band search for color variations and a Principle Components Analysis (PCA) of the 8 unique bands in the THEMIS-IR dataset. Any variability is then investigated using both THEMIS-IR and TES spectra of the same regions. In both cases, the spectra are ratioed to near-simultaneously acquired spectra of adjacent or "average" regions that do not show this albedo variation, therefore allowing us to identify spectral variability unique to

  3. 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.

  4. 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.

  5. 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.

  6. Kasei Valles, Mars - Interpretation of canyon materials and flood sources

    NASA Technical Reports Server (NTRS)

    Tanaka, Kenneth L.; Chapman, Mary G.

    1992-01-01

    Kasei Valles form the most immense outflow channel system on Mars. Here, the materials that make up the canyon walls and floors of Kasei Valles are investigated along with the sources of the flood waters. It is proposed that the geological sequence of plateau materials through which Kasei Valles cuts is capped by ridged plains material overlying relatively weak Noachian plateau materials that increase in resistance to erosion below 1000 m depth. Flooding began in the Late Hesperian, probably originating from the Tharsis rise, here volcanotectonic activity produced high ground-water pressures. Ground water sluiced through hydrofractures above the resistant zone at 1000 m depth and erupted in northern Kasei Valles, forming mostly northeast-trending troughs of Sacra Fossae and etching joints in the ridged plains material. Some of the flood water invaded the upper weak zone of the Noachian plateau materials, producing chaotic and knobby terrains of low relief.

  7. Continental-Scale Salt Tectonics on Mars and the Origin of Valles Marineris and Associated Outflow Channels

    NASA Astrophysics Data System (ADS)

    Montgomery, D. R.; Som, S. M.; Schreiber, B. C.; Jackson, M. P.; Gillespie, A. R.; Adams, J. B.

    2007-12-01

    A synthesis of regional deformation patterns of the Thaumasia Plateau, Mars, leads to a new interpretation for regional deformation and the origin of Valles Marineris and associated outflow channels. The morphology of the Thaumasia Plateau is typical of thin-skinned deformation, akin to a "mega-slide," in which extensional deformation in Syria Planum and Noctis Labyrinthus connects via zones of lateral transtension - Claritas Fossae and Valles Marineris - to a broad zone of compressional uplift and shortening defined by truncated craters and thrust faults along the Coprates Rise and Thaumasia Highlands. However, the low regional slope (?1°) results in gravitational body forces that are too small to deform the basaltic lava flows conventionally thought to compose the flanks of the Tharsis volcanic province. Instead, we conclude that geothermal heating and topographic loading of extensive buried deposits of salts (or mixtures of salts, ice, and basaltic debris) would allow for weak detachments and large-scale gravity spreading. We propose that the generally linear chasmata of Valles Marineris reflect collapse and excavation along pre-existing extension fractures radial to Tharsis, reactivated as part of one lateral margin of the Thaumasia gravity spreading system. The other, dextral, lateral margin is a massive splay of extensional faults forming the Claritas Fossae, which resembles a trailing extensional imbricate fan. The compressional mountain belt defined by the Coprates Rise and Thaumasia Highlands forms the toe of the "mega-slide." Topographic observations and previous structural analyses reveal evidence for a failed volcanic plume below Syria Planum that could have provided both thermal energy and topographic potential for initiating regional deformation. Increased geothermal heating over time, or heating simply due to increasing depth in the crust due to continuing burial, would have contributed to flow of salt deposits, as well as formation of groundwater

  8. Reassessing rock mass properties and slope instability triggering conditions in Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni Battista; Utili, Stefano; De Blasio, Fabio Vittorio; Castellanza, Riccardo

    2014-02-01

    The rock walls of the Valles Marineris valleys (VM) in the equatorial area of Mars exhibit several gravitational failures which resulted in a series of large landslides up to several hundred cubic kilometers in volume. Questions arise as to forces at play and rock strength in the stability of the walls of VM. In this work we address the stability analysis of the walls of VM by considering the strength of the materials of the walls and the causes of landslides. Using finite element calculations and the limit analysis upper bound method, we explore the range of cohesion and friction angle values associated with realistic failure geometries, and compare predictions with the more classical Culmann's translational failure model. Our analysis is based both on synthetic, simplified slope profiles, and on the real shape of the walls of VM taken from the MOLA topographic data. Validation of the calibrated cohesion and friction angle values is performed by comparing the computed unstable cross sectional areas with the observed pre- and post-failure profiles, the estimated failure surface geometry and ridge crest retreat. This offers a link between rock mass properties, slope geometry and volume of the observed failure, represented in dimensionless charts. The role of groundwater flow and seismic action on the decrease of slope stability is also estimated. Pseudo-static seismic analyses provide another set of dimensionless charts and show that low seismicity events induced by meteoroid impacts, consistent with the size of craters, could be a cause for some of the observed landslides, if poor rock properties for VM are assumed. Analyses suggest that rock mass properties are more similar to their earth equivalents with respect to what has been previously supposed.

  9. 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

  10. 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

  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)

    Kromuszczyńska, 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. Multi-sulfate and Iron Oxide Assemblages Within the Valles Marineris Interior Layered Deposits

    NASA Astrophysics Data System (ADS)

    Roach, L. H.; Mustard, J. F.; Murchie, S. L.; Bishop, J. L.; Arvidson, R. E.; Morris, R. V.; Milliken, R. E.; Lichtenberg, K. A.

    2007-12-01

    MarsExpress OMEGA showed that many of the Interior Layered Deposits (ILDs) in Valles Marineris contain sulfates and proposed the sulfates as indicators of past aqueous activity in the Theiikian period (Gendrin etal, 2005; Bibring etal, 2005; Bibring etal, 2006). Better discrimination of the sulfate assemblages present and the stratigraphic relationships within the ILD is critical to understanding the environment during and since their formation. We present a method for identifying classes of sulfates present in a multi-sulfate exposure with MRO CRISM data. Multiple mineral phases can be defined by diagnostic absorptions in spatially distinct wavelength regions. Combinations of minerals phases is more complicated but can be resolved by identifying superposed absorption feature and assuming linear mixing. We focus on four wavelength regions: (a) 2.4 and 2.1 μm, (b) 2.2 μm, (c) 1.9 and 1.4 μm, and (d) 0.9 μm, in a methodical classification of possible sulfate types present. While there is some overlap in the wavelength regions, absorptions are sufficiently separate to be recognizable. Additionally, care must be taken to select geologically feasible minerals assemblages. (a) Hydrated sulfates have an absorption near 2.4 um due to probable interactions between the H2O and SO3 molecules (Cloutis etal, 2006). Monohydrated sulfates have a distinct absorption near 2.1 μm due to combinations of H2O stretch and rotation vibrations of the single water molecule in a sulfate structure (Cloutis etal, 2006) which shifts with cation. Thus minerals such as kieserite (MgSO4 H2O) and szomolnokite (Fe2+SO4 H2O) can be distinguished in CRISM data. (b) The 2.21-2.26 μm region is generally convex in sulfates, but gypsum (CaSO4 2H2O ) and jarosite group members (MFe3(SO4)2(OH)6) have absorptions there. The minimum within this wavelength region depends on the mineral present. (c)The ~1.9 μm is due to the OH stretch and H2O bend combination tone and the ~1.4 μm absorption is due to

  13. Volcanism and Fluvio-Glacial Processes on the Interior Layered Deposits of Valles Marineris, Mars?

    NASA Astrophysics Data System (ADS)

    Chapman, M. G.

    2005-12-01

    The Interior Layered Deposits (ILDs) in Valles Marineris have been suggested to be possible sub-ice volcanoes. Recent images also show evidence of possible fluvio-glacial processes on the ILDs and hence volcano/ice/water interaction. For example, Mars Express Mission anaglyph from Orbit 334 of central Ophir and Candor Chasmata, THEMIS image V10551002, and MOC images E1700142 and E190020 show 2 ILD mounds in central Candor Chasma that have been sheared off at approximately equal elevations by some material that has been subsequently removed. Level shearing of ILD rock materials and subsequent removal of the abrasive material, suggest ice erosion and glacial processes because glacial ice is mobile enough to grind the rock and can melt away. Another adjacent ILD mound in Central Candor shows an abrupt flank termination and damming of material, rather than flank scour. The dammed material appears to be layers piled up in a ridge at the ILD base. This relation is observed on the HRSC anaglyph and MOC images E0101343 and E201146. Another ILD in Melas Chasma, seen on MOC image M0804981, shows lobes of flank material that terminate along a lineation; possibly suggesting lobe confinement against subsequently removed material. This morphology can also be observed on the flank of the Gangis Chasma ILD in MOC image M0705587. A possible terrestrial volcanic analog for this ILD flank morphology is the Helgafell hyaloclasitic ridge (tindar) in Iceland (Chapman et al., 2004), the eastern flank of which has a linear termination interpreted as largely unmodified and caused by hyalotuff material banked against a former ice wall that has since melted away (Schopka et al., 2003). Glacial shearing of some ILDs and confined banking of other ILDs suggest that these mounds formed at different times, as the sheared ILD likely predated ice and the confined ILD may have formed concurrently with ice. Alternatively, the banking may have been due to lack of shear forces (static ice) and confined

  14. Estimation of dust variability and scale height of atmospheric optical depth (AOD) in the Valles Marineris on Mars by Indian Mars Orbiter Mission (MOM) data

    NASA Astrophysics Data System (ADS)

    Mishra, Manoj K.; Chauhan, Prakash; Singh, Ramdayal; Moorthi, S. M.; Sarkar, S. S.

    2016-02-01

    In this paper analyses of bright hazes observed inside Valles Marineris formed during mid-southern spring of Mars is presented. The analysis is performed by using data collected by Mars Colour Camera (MCC) onboard Indian Mars Orbiter Mission on orbits 34, 49 and 52 corresponding to the observation dates of October 28, December 5 and December 13, 2014. It is found that during all these orbits the valley was hazy. On orbit 34 a thick layer of haze was observed, which became relatively thinner on orbit 49. Thick haze reappeared after eight days on orbit 52. We also measured the optical depth of martian atmosphere as a function of altitude above two opposing walls (northern and southern walls of the Valles Marineris near Coprates Chasma region) of the valley, from stereo images that were taken with MCC on December 5, 2014. The optical depth was measured from contrast comparisons of the stereo images with "stereo method". In the northern wall of Valles, we estimated the optical depth as a function of altitude (ranging between -6 km and 3 km) and found values between 1.7 (bottom) and 1.0 (top) in red channel and between 2.1 (bottom) and 1.2 (top) in green channel. A fit to these results yields a scale height for the optical depth of 14.08 km and 11.24 km in red and green channel, which are more or less in good agreement to the pressure scaled height of martian atmosphere at that time in the region as consulted from Global Circulation Model (GCM). We also estimated optical depth in southern wall of Valles Marineris. However, in this case optical depth remains nearly constant with decreasing altitude. We consulted GCM for wind direction in the region and found strong wind with direction from south-west to north-east intersecting the mountain like structure of the southern wall of Valles Marineris. Our optical depth results and the wind direction suggest the presence of lee-wave cloud above the southern wall of Valles Marineris.

  15. 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 μm, 1.9 μm, and a narrow band at 2.2 μm. 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

  16. Complex Floor Deposits Within Western Ganges Chasma, Valles Marineris - High Resolution Image

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image shows the area near the canyon wall, where large blocks of the upland surface have slumped down into the canyon. Close inspection of this image shows numerous small dark dots that are in fact individual rocks on the surface of Mars. These rocks vary from the size of a small automobile to the size of a house, have fallen down steep slopes.

    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.

  17. 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 μm, 2.33 μm, 2.22 μm, 2.48 μm and 2.52 μm 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.

  18. 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.

  19. 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.

  20. 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

  1. Martian canyons and African rifts: Structural comparisons and implications

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    1978-01-01

    The resistant parts of the canyon walls of the Martian rift complex Valled Marineris were used to infer an earlier, less eroded reconstruction of the major roughs. The individual canyons were then compared with individual rifts of East Africa. When measured in units of planetary radius, Martian canyons show a distribution of lengths nearly identical to those in Africa, both for individual rifts and for compound rift systems. A common mechanism which scales with planetary radius is suggested. Martian canyons are significantly wider than African rifts. The overall pattern of the rift systems of Africa and Mars are quite different in that the African systems are composed of numerous small faults with highly variable trend. On Mars the trends are less variable; individual scarps are straighter for longer than on earth. This is probably due to the difference in tectonic histories of the two planets: the complex history of the earth and the resulting complicated basement structures influence the development of new rifts. The basement and lithosphere of Mars are inferred to be simple, reflecting a relatively inactive tectonic history prior to the formation of the canyonlands.

  2. Magnitude of a catastrophic flood event at Kasei Valles, Mars

    NASA Astrophysics Data System (ADS)

    Robinson, Mark S.; Tanaka, Kenneth L.

    1990-09-01

    Kasei Valles compose an enormous outflow-channel system on Mars. The upper part of the channel system is typically less than 1 km deep and descends from Echus Chasma about 1 km over a distance of 1000 km; it then splits into north and south channels. On the basis of a stereomodel of Viking images, we have measured the geometry of a steep, constricted reach of the north channel that drops 900 m in only 100 km. A late-stage flood is hypothesized to have scoured the channel. If we assume that channel striations indicate water levels, then the flood had a minimum cross-sectional area of 3.12 x 107 m2 (the putative flood had a width of 83 km, an average depth of 374 m, and maximum depth of 1280 m). These channel measurements suggest that flood velocities ranged from 32 to 75 mṡs-1 and that discharge was greater than 1 km3ṡs-1, values larger than those calculated for any other flood event on Mars or Earth. The flood maintained supercritical flow and caused intense erosion in this area, scouring a 350-m-deep megapothole. The source of the flood water may have been a temporary lake in Echus Chasma, a deep canyon formed in association with tectonism at Valles Marineris.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Ares Valles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    This image covers a portion of Ares Valles. Ares Valles is an outflow channel carved into the surface of Mars by ancient catastrophic floods. The floods were most likely caused by huge discharges of groundwater at the channel heads. These floods are similar to (but much larger than) floods that created the Channeled Scablands in central Washington State during the last ice age on Earth. The Martian channels are hundreds of kilometers long and occur in a number of regions within equatorial Mars. The material that was eroded away by these floods was deposited as sediment in the northern lowlands. The Mars Pathfinder landing site is several hundred kilometers downstream from the location of this image and the surfaces are probably similar in nature.

    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.

  8. 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 ...

  9. Tader Valles

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 18 July 2003

    Tader Valles, an ancient name for the present Segura River in Spain, is a set of small channels at mid-southern latitudes that is filled by smooth material with rounded margins. It is possible that this material is snow covered by a mantle of dust or dirt.

    Image information: VIS instrument. Latitude -49.4, Longitude 208.6 East (151.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. Mawrth Valles

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    This false color image of an old channel floor and surrounding highlands is located in the lower reach of Mawrth Valles. This image was collected during the Northern Spring season.

    Image information: VIS instrument. Latitude 25.7, Longitude 341.2 East (18.8 West). 35 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

  11. Kasei Valles

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 2 June 2004 This image was collected July 17, 2002 during northern spring season. The local time at the image location was about 4 pm. The image shows an area in the Kasei Valles region.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 25.3, Longitude 298.8 East (61.2 West). 38 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

  12. Hebrus Valles

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 3 June 2002) The Science Hebrus Valles is located in the Elysium Planitia region of the northern lowlands of the planet. This image shows three sinuous tributaries of the channel system which carved up the surrounding plains. These individual tributaries are up to 3 km wide and have up to three terraces visible along their margins. These terraces may indicate separate flood events or may be the result of one flood plucking away at channel wall materials with varying strengths of resistance. It is not clear if these are separate rock layers or just the erosion of one type of material from rising and falling water levels. A streamlined island is visible in the lower third of the image. This feature indicates that flow was from the lower right to upper left in this region (the tail of the island points downstream). In places ripples, interpreted to be dunes, can also be seen along the interface of the channel floor with the walls. Smaller, fainter channels can also be seen scouring the plains, especially in the lower portion of this image. Other features of note in this image are the various inselbergs (isolated hills) located primarily in the upper portion of the image. The inselbergs are surrounded with aprons of material that was probably shed off of the hills by various processes of erosion. The Story Mars was once the scene of some major floods that rushed out upon the land, carving all kinds of channels. These signs of ancient flooding have always been exciting to scientists who want to understand the history of water on the planet. Water is important to understanding the climate and geological history of Mars, as well as whether life could ever have developed there. While we can't tell much about the life question from pictures like this one, it does give some insights into the great flood itself. You can see three tributaries of a channel system that are up to two miles wide or so. The really interesting thing is that you can see terraces of land

  13. 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.

  14. Mechanical approach on Deep-seated Gravitational Spreading in Coprates Chasma, Valles Marineris, Mars.

    NASA Astrophysics Data System (ADS)

    Makowska, M.; Gueydan, F.; Mège, D.

    2014-04-01

    Deep-seated gravitational spreading (DSGS; known also as sackung [1]) is a type of slope defamation involving collapse of a large blocks along structural features and faults, leading to formation of crestal graben, uphill-facing scarps and downslope bulging morphology. DSGS occurs on high wallslopes, with small rate of displacement but height comparable to the whole slope height. Occurences of DSGS are usually connected with formerly glaciated mountain ridges on Earth and on Mars [4] (Fig. 1). Vertical offset does usually not exceed ~10 metres on Earth, whereas on Mars it is at least one order of magnitude higher, consistent with vertical scaling between slope height and vertical fault offset [5].

  15. 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."

  16. 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."

  17. 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.

  18. 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.

  19. Bedforms in Maja Valles

    NASA Technical Reports Server (NTRS)

    2004-01-01

    8 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows large, light-toned, ripple-like windblown bedforms in a portion of the giant flood channel complex, Maja Valles. Ripples such as these are very common on Mars but not very well understood. They are larger than most ripples on Earth, and smaller than typical dunes. They are usually old, and probably immobile, features. Sometimes, larger, dark sand dunes are seen riding over them (although that is not the case here). If similarly-sized ripples were to be investigated by a Mars rover, they would probably provide critical information that would help determine the nature of bedforms like these all over Mars. The Maja Valles scene shown here is located near 17.7oN, 54.8oW, and covers an area about 1.4 km (0.9 mi) wide. Sunlight illuminates the scene from the lower left.

  20. Canyon Dust

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03682 Canyon Dust

    These dust slides are located on the wall of Thithonium Chasma.

    Image information: VIS instrument. Latitude -4.1N, Longitude 275.7E. 17 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.

  1. Canyon Variety

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03281 Canyon Variety

    This image shows paret of the west end of Melas Chasma. Landslide deposits are visible at the top of the image, with dark dunes appearing at the bottom.

    Image information: VIS instrument. Latitude -8.2N, Longitude 281.0E. 17 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.

  2. Subinertial canyon resonance

    NASA Astrophysics Data System (ADS)

    Clarke, Allan J.; Van Gorder, Stephen

    2016-04-01

    Near the bottom of a narrow canyon currents that oscillate back and forth along the bottom slope hx in a stratified ocean of buoyancy frequency N do so with a natural internal gravitational frequency Nhx. From May 2012 to May 2013 Acoustic Doppler Current Profiler measurements were made at 715 m depth in the deep narrow part of the DeSoto Canyon south of Pensacola, Florida, in water with 2π/Nhx ≈ 2.5 days. Above the canyon the flow follows the large-scale isobaths, but beneath the canyon rim the current oscillates along the canyon axis with 2-3 day periodicity, and is much stronger than and uncorrelated with the overlying flow. A simple theoretical model explains the resonant response. Published observations from the Hudson and Gully canyons suggest that the strong subinertial current oscillations observed in these canyons occur close to the relevant local frequency Nhx, consistent with the proposed simple model physics.

  3. 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.

  4. Morphologic evidence of subsurface sediment mobilization and mud volcanism in Candor and Coprates Chasmata, Valles Marineris, Mars

    NASA Astrophysics Data System (ADS)

    Okubo, Chris H.

    2016-05-01

    Populations of distinctive knobs, rings and lobate structures are observed in the Candor and Coprates Chasmata regions of Mars. To interpret the formation mechanisms of these landforms, I investigate their morphologies, facies, superposition and crosscutting relationships using data from the High Resolution Imaging Science Experiment (HiRISE) and the High Resolution Stereo Camera (HRSC). The knobs and rings have quasi-circular to elliptical shapes in map view, with basal diameters between several hundred meters and three kilometers. The knobs rise ∼10 to 350 m above the surrounding terrain, while the rings are ∼10 to 70 m tall. In three dimensions the knobs have a rounded cone shape, and some knobs exhibit a summit depression, which in some examples contains a subordinate mound. The rings have rounded to sharp crests and in some instances contain subordinate rings and mounds. The lobate structures are commonly ∼1 to 2 km wide, ∼3 to 5 km long and rise up to 50 m above the surrounding terrain. The lobate structures partially or completely encircle some knobs, rings and irregularly shaped rock masses. The knobs, rings and lobate structures exhibit massive and stratified facies, with some structures exhibiting both, such as a massive central rock mass surrounded by outwardly dipping layers. I interpret these landforms as mud volcanoes, injectites and mud flows based on superposition and cross-cutting relationships as well as similarities between the morphologies and facies of these landforms with terrestrial products of mud volcanism. I infer the source of sediment for this mud volcanism to be the Hesperian eolian deposits that occur within these chasmata. Further, I suggest that groundwater upwelling during the Hesperian to possibly the Early Amazonian facilitated the mobilization of these sediments within the subsurface and thereby contributed to the ensuing mud volcanism. Based on these results, I propose that the Candor Chaos formed through subsurface sediment mobilization and mud volcanism.

  5. 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).

  6. 4. DARK CANYON SIPHON VIEW ACROSS DARK CANYON AT ...

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

    4. DARK CANYON SIPHON - VIEW ACROSS DARK CANYON AT LOCATION OF SIPHON. VIEW TO NORTHWEST - Carlsbad Irrigation District, Dark Canyon Siphon, On Main Canal, 1 mile South of Carlsbad, Carlsbad, Eddy County, NM

  7. 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.

  8. Geologic Mapping of Athabasca Valles

    NASA Technical Reports Server (NTRS)

    Keszthelyi, L. P.; Jaeger, W. L.; Tanaka, K.; Hare, T.

    2009-01-01

    We are approaching the end of the third year of mapping the Athabasca Valles region of Mars. The linework has been adjusted in response to new CTX images and we are on schedule to submit the 4 MTM quads (05202, 05207, 10202, 10207) and ac-companying paper by the end of this fiscal year.

  9. Downstream in Mawrth Valles

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    This false color image is from further downstream in Mawrth Valles than yesterday's image. The channel here is at the end of the vallis. This image was collected during the Northern Spring season.

    Image information: VIS instrument. Latitude 26.7, Longitude 340.2 East (19.8 West). 37 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

  10. 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

  11. Morphologic contrasts between Nirgal and Auqakuh Valles, Mars: Evidence of different crustal properties

    NASA Technical Reports Server (NTRS)

    Mackinnon, David J.; Tanaka, Kenneth L.; Winchell, Philip J.

    1987-01-01

    Photoclinometric measurements were made of sidewall slopes in Nirgal and Auqakuh Valles and these results were interpreted in terms of the geologic setting and a simple geomorphic model to provide insights into the physical properties of crustal materials in these areas. Nirgal was interpreted to be a runoff channel and Auqakuh to be a fretted channel. Geomorphologic arguments for the sapping origin of Nirgal and Auqakuh Valles were presented. The morphologies of the channels, however, differ greatly: the tributaries of Nirgal end abruptly in theater-headed canyons, whereas the heads of tributaries of Auqakuh shallow gradually. The plateau surface surrounding both channels appears to be covered by smooth materials, presumably lava flows; they are continuous and uneroded in the Nirgal area, but at Auqakuh they are largely eroded and several layers are exposed that total about 200 m in thickness. For Nirgal Valles, the measurements show that sidewalls in the ralatively shallow upper reaches of the channel have average slopes near 30 degrees and, in the lower reaches, sidewall slopes exceed 50 degrees. Auqakuh, on the other hand, has maximum sidewall slopes of 14 degrees and an approximate maximum depth of 1000 m. Faint, horizontal layering in portions of the lower reaches of Nirgal may indicate inhomogeneity in either composition or topography.

  12. Geologic Mapping of Athabasca Valles

    NASA Technical Reports Server (NTRS)

    Keszthelyi, L. P.; Jaeger, W. L.; Tanaka, K.; Hare, T.

    2008-01-01

    Two factors drive us to map the Athabasca Valles area in unusual detail: (1) the extremely well-preserved and exposed surface morphologies and (2) the extensive high resolution imaging. In particular, the near-complete CTX coverage of Athabasca Valles proper and the extensive coverage of its surroundings have been invaluable. The mapping has been done exclusively in ArcGIS, using individual CTX, THEMIS VIS, and MOC frames overlying the THEMIS IR daytime basemap. MOLA shot points and gridded DTMs are also included. It was found that CTX images processed through ISIS are almost always within 300 m of the MOLA derived locations, and usually within tens of meters, with no adjustments to camera pointing. THEMIS VIS images appear to be systematically shifted to the southwest of their correct positions and MOC images are often kilometers off. The good SNR and minimal artifacts make the CTX images vastly more useful than the THEMIS VIS or MOC images. The bulk of the mapping was done at 1:50,000 scale on CTX images. In more complex areas, mapping at 1:24,000 proved necessary. The CTX images were usually simultaneously viewed on a second monitor using the ISIS3 qview program to display the full dynamic range of the CTX data. Where CTX data was not available, mapping was often done at 1:100,000 and most contacts are mapped as approximate.

  13. 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

  14. Sedimentary facies in submarine canyons

    NASA Astrophysics Data System (ADS)

    Sumner, E.; Paull, C. K.; Gwiazda, R.; Anderson, K.; Lundsten, E. M.; McGann, M.

    2013-12-01

    Submarine canyons are the major conduits by which sediment, pollutants and nutrients are transported from the continental shelf out into the deep sea. The sedimentary facies within these canyons are remarkably poorly understood because it has proven difficult to accurately sample these heterogeneous and bathymetrically complex environments using traditional ship-based coring techniques. This study exploits a suite of over 100 precisely located vibracores collected using remotely operated vehicles in ten canyons along the northern Californian margin, enabling better understanding of the facies that exist within submarine canyons, their distribution, and the processes responsible for their formation. The dataset reveals three major facies types within the submarine canyons: extremely poorly sorted, coarse-grained sands and gravels with complex and indistinct internal grading patterns and abundant floating clasts; classical normally graded thin bedded turbidites; and a variety of fine-grained muddy deposits. Not all facies are observed within individual canyons, in particular coarse-grained deposits occur exclusively in canyons where the canyon head cuts up to the modern day beach, whereas finer grained deposits have a more complex distribution that relates to processes of sediment redistribution on the shelf. Pairs of cores collected within 30 meters elevation of one another reveal that the coarse-grained chaotic deposits are restricted to the basal canyon floor, with finer-grained deposits at higher elevations on the canyon walls. The remarkable heterogeneity of the facies within these sediment cores illustrate that distinctive processes operate locally within the canyon. In the authors' experience the canyon floor facies represent an unusual facies rarely observed in ancient outcrops, which potentially results from the poor preservation of ancient coarse-grained canyon deposits in the geological record.

  15. Geologic map of the Valle 30' x 60' quadrangle, Coconino County, northern Arizona

    USGS Publications Warehouse

    Billingsley, George H.; Felger, Tracey J.; Priest, Susan S.

    2006-01-01

    The geologic map of the Valle 30' x 60' quadrangle is the result of a cooperative effort between the U.S. Geological Survey and the National Park Service to provide geologic information for regional resource management and visitor information services for Grand Canyon National Park, Arizona. The map area encompasses approximately 1,960 sq.mi. within Coconino County, northern Arizona and is bounded by long 112 deg to 113 deg W. and lat 35 deg 30 min to 36 deg N. and lies within the southern Colorado Plateaus geologic province (herein Colorado Plateau). The map area is locally subdivided into four physiographic parts; (1) the Grand Canyon (Cataract Canyon and extreme northeast corner of the map area), (2) the Coconino Plateau, (3) the Mount Floyd Volcanic Field, and (4) the San Francisco Volcanic Field as defined by Billingsley and others, 1997. Elevations range from 7,460 ft (2,274 m) on the Coconino Plateau along State Highway 64 northeast corner of the map area, to about 4,200 ft (1,280 m) at the bottom of Cataract Canyon. Settlements within the map area include Tusayan and Valle, Arizona. State Highway 64 and U.S. Highway 180 provide access to the Tusayan and Valle areas. Indian Route 18 is a paved highway in the northwest corner of the map area that is maintained by the Hualapai and Havasupai Indian Tribes and leads from State Route 66 about 7 mi (11 km) east of Peach Springs, Arizona to Hualapai Hilltop, a parking lot just north of the map area at the rim of Cataract Canyon where visitors begin an 8 mi (13 km) hike into Havasupai, Arizona. Other remote parts of the map are accessed by two dirt roads, which are maintained by Coconino County, and by several unmaintained local ranch roads. Weather conditions restrict travel within the area and visitors must obtain permission to access a few local ranch lands in the south-central edge of the map area. Extra water and food are highly recommended when traveling in this remote region. Access into Cataract Canyon is

  16. 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

  17. Juventae Chasma and Maja Valles, Mars: Further Evidence for Multiple Flooding Events

    NASA Astrophysics Data System (ADS)

    Gross, C.; Wendt, L.; Dumke, A.; Neukum, G.

    2009-04-01

    Introduction: In this study we investigate the age relationship of Juventae Chasma to the adjacent Maja Valles in order to gain a feasible explanation for the formation and evolution of rhythmic light-toned layered deposits (LLD). In this first step, we use impact crater size-frequency distributions for dating the planetary surface in the regions of interest. Juventae Chasma is located at the northern side of the Valles Marineris and stretches for approximately 150 km east-west and 250 km north-south. The basin floor shows a depth of 5 km and more below the surrounding surface. To the north lies the adjacent Maja Valles, a 50 km to 150 km wide channel extending for 1600 km northward and discharging into the Chryse Planitia plains. Various investigations of several authors have been carried out on this subject in the past, but the formation of the LLD in Juventae Chasma is still poorly understood. The formation theories range from a volcanic origin [1], lake deposits, delta deposits [2] to spring deposits [3]. A very different hypothesis for the formation of the sulfates is deposition from airfall. This could happen as dry deposition from the atmosphere or in co-precipitation with icy materials such as snow crystals or dust particles. This phenomenon is observed at the poles of Mars, where rhythmic layerings occur showing high similarities to the sulfate deposits in Juventae Chasma. The light-toned materials in the chasma show a spectral signature indicative of kieserite in the outcrops A, C and D and in the lower part of B, whereas the upper part of B was described as gypsum [4]. Wendt et al. [5] identified different mineral assemblages in the cap rock of mount B, using the CRISM instrument and the Multiple-Endmember Linear Spectral Unmixing Model (MELSUM). HRSC DTM: The Digital Terrain Model (DTM ) mosaic (see Fig. 1) was derived from 11 HRSC orbits at approximately -7° S to 8° N and 295° to 301° E with a ground resolution of 100 m per pixel and an ortho

  18. The Whittard Canyon - A case study of submarine canyon processes

    NASA Astrophysics Data System (ADS)

    Amaro, T.; Huvenne, V. A. I.; Allcock, A. L.; Aslam, T.; Davies, J. S.; Danovaro, R.; De Stigter, H. C.; Duineveld, G. C. A.; Gambi, C.; Gooday, A. J.; Gunton, L. M.; Hall, R.; Howell, K. L.; Ingels, J.; Kiriakoulakis, K.; Kershaw, C. E.; Lavaleye, M. S. S.; Robert, K.; Stewart, H.; Van Rooij, D.; White, M.; Wilson, A. M.

    2016-08-01

    Submarine canyons are large geomorphological features that incise continental shelves and slopes around the world. They are often suggested to be biodiversity and biomass hotspots, although there is no consensus about this in the literature. Nevertheless, many canyons do host diverse faunal communities but owing to our lack of understanding of the processes shaping and driving this diversity, appropriate management strategies have yet to be developed. Here, we integrate all the current knowledge of one single system, the Whittard Canyon (Celtic Margin, NE Atlantic), including the latest research on its geology, sedimentology, geomorphology, oceanography, ecology, and biodiversity in order to address this issue. The Whittard Canyon is an active system in terms of sediment transport. The net suspended sediment transport is mainly up-canyon causing sedimentary overflow in some upper canyon areas. Occasionally sediment gravity flow events do occur, some possibly the result of anthropogenic activity. However, the role of these intermittent gravity flows in transferring labile organic matter to the deeper regions of the canyon appears to be limited. More likely, any labile organic matter flushed downslope in this way becomes strongly diluted with bulk material and is therefore of little food value for benthic fauna. Instead, the fresh organic matter found in the Whittard Channel mainly arrives through vertical deposition and lateral transport of phytoplankton blooms that occur in the area during spring and summer. The response of the Whittard Canyon fauna to these processes is different in different groups. Foraminiferal abundances are higher in the upper parts of the canyon and on the slope than in the lower canyon. Meiofaunal abundances in the upper and middle part of the canyon are higher than on adjacent slopes, but lower in the deepest part. Mega- and macrofauna abundances are higher in the canyon compared with the adjacent slope and are higher in the eastern than

  19. Duration and rates of discharge: Maja Valles, Mars

    NASA Technical Reports Server (NTRS)

    Dehon, R. A.; Pani, E. A.

    1992-01-01

    The 1600 km-long Maja Valles outflow system of Mars consists of three major divisions including the upper valley on Lunae Planum, the canyon section across Xanthe Terra, and the lower valley across western Chryse Planitia. Although water released from the source in Juventae Chasma could reach the terminus of the present day valley system in central Chryse Planitia within 44 hours, the original outflow did not traverse the Martian surface in a direct path. It ponded along its course on northern Lunae Planum and near the western edge of Chryse Planitia significantly prolonging the lifetime of surface flow. Calculation of pond volumes and discharge rates through various parts of the channel system indicates that water flowed through this system for nearly a (terrestrial) year. Discharge rates from the various basins along the Maja channels and the maximum flow rates within the various channels are calculated. With this data, it is possible to place reasonable estimates of the minimum length of time required to drain the various impoundments and the duration of flow in various parts of the channel system. The results of these calculations are discussed.

  20. Duration and rates of discharge - Maja Valles, Mars

    NASA Technical Reports Server (NTRS)

    De Hon, R. A.; Pani, E. A.

    1993-01-01

    The 1600 km-long Maja Valles outflow system of Mars consists of three major divisions including the upper valley on Lunae Planum, the canyon section across Xanthe Terra, and the lower valley across western Chryse Planitia. Although water released from the source in Juventae Chasma could reach the terminus of the present day valley system in central Chryse Planitia within 44 hours, the original outflow did not traverse the Martian surface in a direct path. It ponded along its course on northern Lunae Planum and near the western edge of Chryse Planitia significantly prolonging the lifetime of surface flow. Calculation of pond volumes and discharge rates through various parts of the channel system indicates that water flowed through this system for nearly a (terrestrial) year. Discharge rates from the various basins along the Maja channels and the maximum flow rates within the various channels are calculated. With this data, it is possible to place reasonable estimates of the minimum length of time required to drain the various impoundments and the duration of flow in various parts of the channel system. The results of these calculations are discussed.

  1. 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.

  2. Canyon in DCS Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released July 26, 2004 This image shows two representations of the same infra-red image covering a portion of Ganges Chasma. On the left is a grayscale image showing surface temperature, and on the right is a false-color composite made from 3 individual THEMIS bands. The false-color image is colorized using a technique called decorrelation stretch (DCS), which emphasizes the spectral differences between the bands to highlight compositional variations.

    The northern canyon at the top of this image is dominated by a bright red/magenta area consisting primarly basaltic materials on the floor of the canyon and atmospheric dust. Within that area, there are patches of purple, on the walls and in the landslides, that may be due to an olivine rich mineral layer. In the middle of the image, the green on the mesa between the two canyons is from a layer of dust. The patchy blue areas in the southern canyon are likely due to water ice clouds.

    Image information: IR instrument. Latitude -6.6, Longitude 316 East (44 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

  3. 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.

  4. 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.

  5. Canyon waste dump case study

    SciTech Connect

    Land, M.D.; Brothers, R.R. ); McGinn, C.W. )

    1991-01-01

    This data packet contains the Canyonville Canyon Waste Dump results of the various physical environmental sampling. Core samples were taken from the on site waste material. Vertical grab samples were made from these borings. The waste samples were screened fro volatile organic compounds (VOC) and logged for lithology. Soil samples were also tested for VOC. Composite sediment samples were taken using a coring device known as a clam gun. No surface water was available for testing from the intermittent Canyon Wash. The hydrogeology of the Canyon Waste Dump was inferred from lithologic logs and hydraulic data from the five monitoring wells located along the canyon floor. Groundwater was monitored through five wells. The soil vapor and air screening techniques used were adaptations of the EPA ERT and NIOSH methodologies. 4 figs., 9 tabs.

  6. Anatomy of La Jolla Canyon

    NASA Astrophysics Data System (ADS)

    Paull, C. K.; Caress, D. W.; Ussler, W.; Lundsten, E.; McGann, M. L.; Conrad, J. E.; Edwards, B. D.; Covault, J. A.

    2010-12-01

    High-resolution multibeam bathymetry (vertical precision of 0.15 m and horizontal resolution of 1.0 m) and chirp sub-bottom profiler data collected with an autonomous underwater vehicle (AUV) reveal the fine-scale morphology of La Jolla Canyon, offshore southern California. The AUV was pre-programmed to fly three missions within the canyon while maintaining an altitude of 50 m above bottom in water depths between 365 and 980 m. Sparker seismic reflection profiles define the overall geometry of the canyon and its host sediments. A remotely operated vehicle (ROV) was used to ground truth the AUV surveys by collecting video observations, 25 vibracores ≤1.5 m long and 38 horizontal push cores from outcrops on the canyon walls. These tools outline the shape and near sub-bottom character of the canyon and thus provide insight into the processes that generated the present canyon geomorphology. La Jolla Canyon is ~1.5 km across and contains a smaller-scale sinuous axial channel that varies in width from <50 m to >300 m. The total relief on the canyon walls is ~90 m and most of the elevation changes occur along a few steep faces that separate intervening terraces. Fine scale features include <1 m high steps on the surface of the major terraces and the existence of crescent shaped bedforms within the axial channel. Also notable are the numerous slide scars on the canyon flanks and within its axial channel. The sharpness of the textures seen in the multibeam images and ROV observations suggest the canyon is active and sediment failures play an important role in generating the canyon’s present morphology. Vibracores show that the floor of the axial channel is typically covered with >1 m of medium- to fine-grained sand. While collecting vibracores within the axial channel, the sand within a radius of ~2 m were observed to flow down slope, apparently after becoming fluidized. The ease with which failure can be induced on the relatively gentle slopes (~1.4°) within the

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. Academy of the Canyons Report, Fall 2002.

    ERIC Educational Resources Information Center

    Meuschke, Daylene M.; Gribbons, Barry C.

    This report analyzes the Academy of the Canyons (AOC) program at College of the Canyons (COC), California. AOC, a middle college high school, is a collaboration between the William S. Hart High School District and College of the Canyons. The program is designed to provide a supportive, flexible, and academically enriched environment for students…

  12. 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.

  13. 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.

  14. The canyon system on Mars

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.; Mcewen, A. S.; Clow, G. D.; Geissler, P. E.; Singer, R. B.; Schultz, R. A.; Squyres, S. W.

    1992-01-01

    Individual Martian equatorial troughs are described, and their stratigraphy, geomorphology and structure are discussed. Possible origins and the overall sequence of events are addressed. Wall rock, interior layered deposits, irregular floor deposits, fractured floor material, and surficial deposits are examined. Chasma walls, wall stability, pits and pit chains, tributary canyons, and the transition from troughs to channels are also discussed.

  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. Why SRS Matters - H Canyon

    SciTech Connect

    Hunt, Paul; Lewczyk, Mike; Swain, Mike

    2015-02-17

    A video series presenting an overview of the Savannah River Site's (SRS) mission and operations. Each episode features a specific area/operation and how it contributes to help make the world safer. This episode features H Canyon's mission and operations.

  17. 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.

  18. 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.

  19. Global View of Mars Topography

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Annotated Version

    This global map of Mars is based on topographical information collected by the Mars Orbiter Laser Altimeter instrument on NASA's Mars Global Surveyor orbiter. Illumination is from the upper right. The image width is approximately 18,000 kilometers (11,185 miles). Candor Chasma forms part of the large Martian canyon system named Valles Marineris. The location of Southwest Candor Chasma is indicated in the annotated version.

  20. MC-19 Margaritifer Sinus Region

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Mars digital-image mosaic merged with color of the MC-19 quadrangle, Margaritifer Sinus region of Mars. Heavily cratered highlands, which dominate the Margaritifer Sinus quadrangle, are marked by large expanses of chaotic terrain. In the northwestern part, the major rift zone of Valles Marineris connects with a broad canyon filled with chaotic terrain. Latitude range -30 to 0, longitude range 0 to 45 degrees.

  1. Center is at Latitude 30 Degrees North, Longitude 30 Degrees

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Center of the orthographic projection is at latitude 30 degrees N., longitude 30 degrees. The north polar residual ice cap, which is cut by spiral-patterned troughs, is located at the top. The central part is characterized by a dark depression, Chryse basin, where several large outflow channels terminate. The lower-left corner is marked by a vast system of canyons, Valles Marineris, which extends eastward for several thousand kilometers.

  2. 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.

  3. "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

  4. 2. VIEW OF HIGH FLUME, LOOKING DOWN WARM SPRINGS CANYON ...

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

    2. VIEW OF HIGH FLUME, LOOKING DOWN WARM SPRINGS CANYON TO SANTA ANA RIVER CANYON. VIEW TO WEST-NORTHWEST. - Santa Ana River Hydroelectric System, Warm Springs Canyon-SAR-3 Flumes, Redlands, San Bernardino County, CA

  5. Survey of Interest, Canyon Country College of the Canyons Site, January 2001.

    ERIC Educational Resources Information Center

    Dixon, P. Scott; Gribbons, Barry C.

    In the process of planning a new site to serve students in Canyon Country (California), the College of the Canyons (COC) in Santa Clarita surveyed students to assess their needs. Anonymous questionnaires were mailed to the homes of 1,000 randomly selected students who lived in Canyon Country and had attended COC in fall 2000 or spring 2001. Of the…

  6. AmeriFlux US-Vcp Valles Caldera Ponderosa Pine

    DOE Data Explorer

    Litvak, Marcy [University of New Mexico

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Vcp Valles Caldera Ponderosa Pine. Site Description - The Valles Caldera Ponderosa Pine site is located in the 1200km2 Jemez River basin of the Jemez Mountains in north-central New Mexico at the southern margin of the Rocky Mountain ecoregion. The Ponderosa Pine forest is the warmest and lowest (below 2700m) zone of the forests in the Valles Caldera National Preserve. Its vegetation is composed of a Ponderosa Pine (Pinus Ponderosa) overstory and a Gambel Oak (Quercus gambelii) understory.

  7. 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.

  8. 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.

  9. A proposed Laramide proto-Grand Canyon

    NASA Astrophysics Data System (ADS)

    Hill, C. A.; Ranney, W. D.

    2008-12-01

    The absence of "rim gravels" north of Grand Canyon and of "Canaan Peak-type" gravels south of Grand Canyon suggests that a paleocanyon, which intersected the transport of these gravels north and south, may have begun forming in the Laramide in approximately the same position as today's central Grand Canyon. This Laramide-age canyon is envisioned as having flowed generally from the SW to NE; from the Peach Springs Canyon area to Mile 197 where it was captured by karst; then along a N. 60°E joint system to the Kanab Point area where it converged with drainage coming off the west side of the Kaibab arch. From there it flowed north along the west flank of the Kaibab arch to Paleogene Lake Claron. The critical idea suggested by this proposed model is that the modern Colorado River utilized Laramide paleotopography in establishing its course through the central Grand Canyon, with younger sections of the canyon integrating with it later, in the middle to late Miocene. This paleocanyon route, in association with headward erosion from the Grand Wash Cliffs toward the Kaibab arch after 16-17 Ma, helps account for the total volume of rock eroded from Grand Canyon, which cannot be explained by present-day incision rates.

  10. Environmental assessment: Davis Canyon site, Utah

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considering for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has found that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization.

  11. 76 FR 8359 - Boulder Canyon Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... 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, DOE...) is proposing an adjustment to the Boulder Canyon Project (BCP) electric service base charge and...

  12. Environmental assessment: Davis Canyon site, Utah

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high- level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has found that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of the five sites suitable for characterization.

  13. 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.

  14. Small volcanic edifices in Niger and Dao Valles, Mars?

    NASA Astrophysics Data System (ADS)

    Korteniemi, J.; Kukkonen, S.

    2013-09-01

    This work describes structures on the floor of the Niger-Dao Valles channel complex. Based on morphology they are interpreted as possible or probable volcanic edifices. Our findings expand the identified regional volcanic activity to smaller scales.

  15. Living Legacy: A Conversation with Carolina Gomez del Valle.

    ERIC Educational Resources Information Center

    Montessori Life, 1993

    1993-01-01

    Carolina Gomez del Valle has been involved in training other Montessorians in Mexico, Chile, Nicaragua, Peru, and Taiwan. This interview explores her experiences with Montessori education and describes how she has woven her religious training and Montessori philosophy together. (PAM)

  16. Flow Rates and Duration Within Kasei Valles, Mars

    NASA Astrophysics Data System (ADS)

    Williams, R. M.; Phillips, R. J.

    1999-03-01

    Derived maximum discharges for Kasei Valles based on elevations from MOLA are orders of magnitude lower than previously estimated. Morphological relationships within the system suggest a gradual formation including several periods of fluvial activity.

  17. 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 HO

  18. DESCHUTES CANYON ROADLESS AREA, OREGON.

    USGS Publications Warehouse

    Walker, George W.; Winters, Richard A.

    1984-01-01

    An examination of the Deschutes Canyon Roadless Area, Oregon indicated that the area is devoid of mines and active mineral prospects or claims and that there is little likelihood for the occurrence of metallic or nonmetallic mineral resources. There is no evidence to indicate that mineral fuels are present in the roadless area. Nearby parts of central Jefferson County on the Warm Springs Indian Reservation are characterized by higher-than-normal heat flow and by numerous thermal springs, some of which have been partly developed. This may indicate that the region has some as yet undefined potential for the development of geothermal energy.

  19. 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

  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. An experimental approach to submarine canyon evolution

    NASA Astrophysics Data System (ADS)

    Lai, Steven Y. J.; Gerber, Thomas P.; Amblas, David

    2016-03-01

    We present results from a sandbox experiment designed to investigate how sediment gravity flows form and shape submarine canyons. In the experiment, unconfined saline gravity flows were released onto an inclined sand bed bounded on the downstream end by a movable floor that was used to increase relief during the experiment. In areas unaffected by the flows, we observed featureless, angle-of-repose submarine slopes formed by retrogressive breaching processes. In contrast, areas influenced by gravity flows cascading across the shelf break were deeply incised by submarine canyons with well-developed channel networks. Normalized canyon long profiles extracted from successive high-resolution digital elevation models collapse to a single profile when referenced to the migrating shelf-slope break, indicating self-similar growth in the relief defined by the canyon and intercanyon profiles. Although our experimental approach is simple, the resulting canyon morphology and behavior appear similar in several important respects to that observed in the field.

  2. Environmental assessment overview, Davis Canyon site, Utah

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization. 3 figs.

  3. 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

  4. 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

  5. 36 CFR 7.19 - Canyon de Chelly 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 Canyon de Chelly National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.19 Canyon de Chelly National Monument. (a) Visitors are prohibited from entering the canyons of Canyon de Chelly National Monument...

  6. 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 (χ) 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.

  7. 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 (χ) 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.

  8. 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.

  9. 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.

  10. The key to Understand Submarine Canyon Evolution

    NASA Astrophysics Data System (ADS)

    Baztan, J.; Berne, S.; Olivet, J.; Rabineau, M.; Aslanian, D.

    2004-12-01

    Submarine canyons are the preferential path of sediment transfer from the shelf to the deep sea, they are the key to understand the source-to-sink sedimentation and, in consequence, the shelf, slope and rise evolution. Pioneer works on submarine canyons described and proposed hypothesis to explain the formation and evolution of them. However, submarine canyons remain a matter of speculation. Our work in the Gulf of Lions (Mediterranean Sea) is based on swath bathymetry data together with sub-bottom profiles, high resolution seismic reflection profiles and cores. These data allow a detailed morphologic and stratigraphic study from the shelf to the rise through time, from 2.600.000 yrs to present. We show that two main erosive features, of very different dimensions, constitute the canyons: the axial incision and the canyon's major valley. The axial incision is interpreted as an erosive path related to the passage of hyperpycnal turbidity currents, generated up-slope by river connection. In the Gulf of Lions such currents are most likely to have formed during each Glacial Maxima (with a cyclicity of 100.000 years for the last 900.000 years and 40.000 years between 900.000 and 2.600.000 years) as both proximity of the shoreline (due to the lowstand of sea level) and high detrital sediment supply (due to glacial abrasion upstream) increased the flow of sediments delivered to the canyon heads. The axial incisions observed at the sea floor and fossil incisions observed on seismic lines, are related to equivalent conditions. The axial incision activity has a key influence on canyon evolution, it triggers mass wasting that affect the canyon's major valley (head and flanks) allowing the progressive widening and deepening of the canyon. Consequently the canyon's major valley (typically bounded by flanks of more than 700 meters in height) is the result of the axial incision activity through successive lowering of sea level. In summary: our cross-disciplinary approach

  11. A Diablo Canyon double feature

    SciTech Connect

    Miller, C.

    1996-03-01

    The current controversy and uncertainty surrounding the disposal of low-level radioactive waste makes it ever more prudent to develop methods to minimize its generation in the first place. As the industry is challenged with active opposition, missed deadlines, and political challenges, Pacific Gas and Electric`s Diablo Canyon nuclear station has implemented a plan to reduce waste generation from plant systems, from the modification and removal of plant equipment, and from the use of protective clothing and consumable contamination-control items. Our program has been extremely effective and may serve as a model for other nuclear power plants at a time of increasing processing and disposal costs. In 1994, for example, we were able to cut our radwaste generation in half-twice.

  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. Satellites See Smoke from Fourmile Canyon Fire

    NASA Video Gallery

    On the morning of September 6, 2010, a wildfire known as the Fourmile Canyon Fire broke out just west of Boulder, Colorado. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terr...

  15. Environmental assessment: Davis Canyon site, Utah

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has fond that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization. 181 figs., 175 tabs.

  16. 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.

  17. 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.

  18. Latitude 90 Degrees North to 90 Degrees South and Longitude 0 Degrees to 180 Degrees

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The coordinates of the Lambert azimuthal equal area projection are latitude 90 degrees N. to 90 degrees S. and longitude 0 degree to 180 degrees. Both polar residual ice caps are seen at top and bottom. The central part is dominated by the four largest and youngest volcanoes on Mars--Olympus, Arsia, Pavonis, and Ascraeus Montes--and by a vast system of canyons several thousand kilometers long--Valles Marineris. Directly to the northeast of Valles Marineris, several large outflow channels terminate at a dark depression, Chryse basin. The lower-right corner is marked by the large Argyre basin, defined by an expanse of light-colored plains 800 km across.

  19. Wintertime Boundary Layer Structure in the Grand Canyon.

    NASA Astrophysics Data System (ADS)

    Whiteman, C. David; Zhong, Shiyuan; Bian, Xindi

    1999-08-01

    Wintertime temperature profiles in the Grand Canyon exhibit a neutral to isothermal stratification during both daytime and nighttime, with only rare instances of actual temperature inversions. The canyon warms during daytime and cools during nighttime more or less uniformly through the canyon's entire depth. This weak stability and temperature structure evolution differ from other Rocky Mountain valleys, which develop strong nocturnal inversions and exhibit convective and stable boundary layers that grow upward from the valley floor. Mechanisms that may be responsible for the different behavior of the Grand Canyon are discussed, including the possibility that the canyon atmosphere is frequently mixed to near-neutral stratification when cold air drains into the top of the canyon from the nearby snow-covered Kaibab Plateau. Another feature of canyon temperature profiles is the sharp inversions that often form near the canyon rims. These are generally produced when warm air is advected over the canyon in advance of passing synoptic-scale ridges.Wintertime winds in the main canyon are not classical diurnal along-valley wind systems. Rather, they are driven along the canyon axis by the horizontal synoptic-scale pressure gradient that is superimposed along the canyon's axis by passing synoptic-scale weather disturbances. They may thus bring winds into the canyon from either end at any time of day.The implications of the observed canyon boundary layer structure for air pollution dispersion are discussed.

  20. 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.

  1. Postcollapse Volcanism in the Valles Caldera, New Mexico: Magma System Dynamics During a Transition Between Large Volume Explosive and Small Volume Effusive Eruptions

    NASA Astrophysics Data System (ADS)

    Spell, T. L.; Gibler, K. I.

    2007-12-01

    The Valles Caldera formed during eruption of the ~250 km3 upper Bandelier Tuff at 1.26 Ma. Following caldera collapse a series of 3 intracaldera rhyolites (Deer Canyon, Redondo Creek and Del Medio) erupted within 54 ka. They are petrographically diverse, ranging from coarsely porphyritic (Deer Canyon type B, Redondo Creek) to nearly aphyric (Deer Canyon type A, Del Medio) and contain distinctive phenocryst assemblages. Disequilibrium textures are common and include resorbed quartz, strongly resorbed plagioclase, antirapikivi feldspars, and zoned sanidine and plagioclase. Plagioclase in Deer Canyon rhyolite ranges widely from labradorite (An60) to oligoclase (An24). Most are andesine in composition and often exhibit oscillatory zonation with overgrowths up to ~200 um wide. Alkali feldspars include both anorthoclase and sanidine with a total variability in Or content of ~50%. Plagioclase and alkali feldspars in Redondo Creek rhyolite show less variability, but similarly large ranges. One phenocryst exhibits an andesine core, oligoclase overgrowth, and sanidine rim. Del Medio rhyolite lacks plagioclase, but contains alkali feldspars (both anorthoclase and sanidine) with variability in Or content of ~30%. Patchy zonation is common, with Or content within phenocrysts varying by ~7%. Redondo Creek rhyolite ranges from ~72-74 wt.% SiO2 whereas Deer Canyon and Del Medio are high silica rhyolites with ~76-78 wt.% SiO2. Trace elements show more significant variability. Redondo Creek samples have low Nb, Rb, Sc, and Lu and high La, Sr, Ba and Hf compared to Del Medio samples. In contrast, Deer Canyon samples exhibit extreme variability in trace element concentrations (e.g., Nb ranging from 32-83 ppm). Incompatible trace element ratios (Th/Nb, Th/Yb, Ta/Yb) versus Nb plots show that Redondo Creek and Del Medio samples have distinctive, limited compositions, whereas Deer Canyon exhibits widely varying values (e.g., Th/Yb ranging from ~3.5-10.5). 238U/206Pb ion microprobe dating

  2. 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

  3. 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.

  4. AmeriFlux US-Vcm Valles Caldera Mixed Conifer

    DOE Data Explorer

    Litvak, Marcy [University of New Mexico

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Vcm Valles Caldera Mixed Conifer. Site Description - The Valles Caldera Mixed Conifer site is located in the 1200 km2 Jemez River basin in north-central New Mexico. Common to elevations ranging from 3040 to 2740 m in the region, the mixed conifer stand, within the entirety of the tower footprint in all directions, provides an excellent setting for studying the seasonal interaction between snow and vegetation.

  5. A geological and geophysical appraisal of the Baca geothermal field, Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Wilt, Michael; Vonder Haar, Stephen

    1986-03-01

    The Baca location #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 260°C at depths of less than 2 km. Stratigraphically the reservoir region can be described as a five-layer sequence that includes Tertiary and Quaternary volcanic rocks, and Mesozoic and Tertiary sediments overlying Precambrian granitic basement. Production is mainly 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 in its western half. 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. Telluric and magnetotelluric data have also identified possible fault zones in the eastern and western sections of the production region that may form boundaries to the Redondo Creek reservoir. These data also suggest that the reservoir region is located at the intersection of lineaments that trend north-south and northeast-southwest. Magnetotelluric results indicate deep low resistivity at the western edge of the caldera which may be associated with deep hot fluids. On the basis of geophysical and well data, we make three estimates of reservoir dimensions. The estimates of the areal extent of the reservoir range from 10 to 30 km 2

  6. 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.

  7. Karst hydrology of Grand Canyon, Arizona, USA

    NASA Astrophysics Data System (ADS)

    Hill, C. A.; Polyak, V. J.

    2010-09-01

    SummaryCaves in Grand Canyon, Arizona, USA fall into two main categories: those formed under unconfined conditions and those formed under confined conditions. This study focuses on the hydrology and paleohydrology of the confined caves in the Redwall-Muav aquifer, where the aquifer is overlain by rocks of the Supai Group and underlain by the Bright Angel Shale. Unconfined caves are discussed only in their relation to confined caves. Discharge for confined groundwater was, as it is today, primarily from the Redwall Limestone where it has been incised by the main canyon or its tributaries and where it has converged along a structural low or fault. Descent of the potentiometric surface (or water table) over time is recorded by one ore episode and six cave episodes: (1) emplacement of Cu-U ore, (2) precipitation of iron oxide in cavities, (3) dissolution of cave passages, (4) precipitation of calcite-spar linings over cave passage walls, (5) precipitation of cave mammillary coatings, (6) minor replacement of cave wall and ceiling limestone by gypsum, and (7) deposition of subaerial speleothems. The mammillary episode records the approximate position of the water table when the incision of the canyon was at that level. Discharge toward spring points has reorganized and adjusted with respect to ongoing canyon and side-canyon incision. The dissolution of Grand Canyon confined caves was the result of the mixing of epigene waters with hypogene waters so that undersaturation with respect to calcite was achieved. The karst hydrology of Grand Canyon may be unique compared to other hypogene cave areas of the world.

  8. Modelling Aerosol Dispersion in Urban Street Canyons

    NASA Astrophysics Data System (ADS)

    Tay, B. K.; Jones, D. P.; Gallagher, M. W.; McFiggans, G. B.; Watkins, A. P.

    2009-04-01

    Flow patterns within an urban street canyon are influenced by various micrometeorological factors. It also represents an environment where pollutants such as aerosols accumulate to high levels due to high volumes of traffic. As adverse health effects are being attributed to exposure to aerosols, an investigation of the dispersion of aerosols within such environments is of growing importance. In particular, one is concerned with the vertical structure of the aerosol concentration, the ventilation characteristics of the street canyon and the influence of aerosol microphysical processes. Due to the inherent heterogeneity of the aerosol concentrations within the street canyon and the lack of spatial resolution of measurement campaigns, these issues are an on-going debate. Therefore, a modelling tool is required to represent aerosol dispersion patterns to provide insights to results of past measurement campaigns. Computational Fluid Dynamics (CFD) models are able to predict detailed airflow patterns within urban geometries. This capability may be further extended to include aerosol dispersion, by an Euler-Euler multiphase approach. To facilitate the investigation, a two-dimensional, multiphase CFD tool coupled with the k-epsilon turbulence model and with the capability of modelling mixed convection flow regimes arising from both wind driven flows and buoyancy effects from heated walls was developed. Assuming wind blowing perpendicularly to the canyon axis and treating aerosols as a passive scalar, an attempt will be made to assess the sensitivities of aerosol vertical structure and ventilation characteristics to the various flow conditions. Numerical studies were performed using an idealized 10m by 10m canyon to represent a regular canyon and 10m by 5m to represent a deep one. An aerosol emission source was assigned on the centerline of the canyon to represent exhaust emissions. The vertical structure of the aerosols would inform future directives regarding the

  9. 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.

  10. 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.

  11. 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

  12. Overview of the Colorado River Canyon from the helicopter pad. ...

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

    Overview of the Colorado River Canyon from the helicopter pad. View of the Nevada side where new bridge will cross canyon, view northwest - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  13. 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

  14. Tectonic activity and the evolution of submarine canyons: The Cook Strait Canyon system, New Zealand

    NASA Astrophysics Data System (ADS)

    Micallef, Aaron; Mountjoy, Joshu; Barnes, Philip; Canals, Miquel; Lastras, Galderic

    2016-04-01

    Submarine canyons are Earth's most dramatic erosional features, comprising steep-walled valleys that originate in the continental shelf and slope. They play a key role in the evolution of continental margins by transferring sediments into deep water settings and are considered important biodiversity hotspots, pathways for nutrients and pollutants, and analogues of hydrocarbon reservoirs. Although comprising only one third of continental margins worldwide, active margins host more than half of global submarine canyons. We still lack of thorough understanding of the coupling between active tectonics and submarine canyon processes, which is necessary to improve the modelling of canyon evolution in active margins and derive tectonic information from canyon morphology. The objectives of this study are to: (i) understand how tectonic activity influences submarine canyon morphology, processes, and evolution in an active margin, and (2) formulate a generalised model of canyon development in response to tectonic forcing based on morphometric parameters. We fulfil these objectives by analysing high resolution geophysical data and imagery from Cook Strait Canyon system, offshore New Zealand. Using these data, we demonstrate that tectonic activity, in the form of major faults and structurally-generated tectonic ridges, leaves a clear topographic signature on submarine canyon location and morphology, in particular their dendritic and sinuous planform shapes, steep and linear longitudinal profiles, and cross-sectional asymmetry and width. We also report breaks/changes in canyon longitudinal slope gradient, relief and slope-area regression models at the intersection with faults. Tectonic activity gives rise to two types of knickpoints in the Cook Strait Canyon. The first type consists of low slope gradient, rounded and diffusive knickpoints forming as a result of short wavelength folds or fault break outs and being restored to an equilibrium profile by upstream erosion and

  15. Nomograms for calculating pollution within street canyons

    NASA Astrophysics Data System (ADS)

    Buckland, A. T.; Middleton, D. R.

    The Environment Act 1995 has introduced the notion of local air quality management which requires that air quality in towns be reviewed and assessed. There is a need to identify those streets that are worst affected by vehicular pollutants. Such worst cases are likely to be narrow congested streets with tall buildings on each side. A nomogram presented here allows rapid screening of pollution in congested street canyons. The strong dependence on wind direction is reduced to the two extremes, namely wind along and wind across the canyon. Then canyon concentrations are estimated according to street geometry and traffic flow. The nomogram is designed for use by local authorities, is quick and easy to use, and paper or computer versions are available. It is suggested that detailed monitoring or modelling may only be required when simple screening methods predict high air pollution.

  16. 7. DARK CANYON SIPHON Photographic copy of construction drawing ...

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

    7. DARK CANYON SIPHON - Photographic copy of construction drawing c1907 (from Record Group 115, Box 17, Denver Branch of the National Archives, Denver) DARK CANYON SIPHON PLAN, ELEVATION, AND SECTIONS - Carlsbad Irrigation District, Dark Canyon Siphon, On Main Canal, 1 mile South of Carlsbad, Carlsbad, Eddy County, NM

  17. 6. DARK CANYON SIPHON Photographic copy of historic photo, ...

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

    6. DARK CANYON SIPHON - Photographic copy of historic photo, January 29, 1907 (original print filed in Record Group 115, National Archives, Washington, D.C.) W.J.Lubken, photographer 'RIPRAP AT THE ENTRANCE END OF DARK CANYON PRESSURE PIPE' - Carlsbad Irrigation District, Dark Canyon Siphon, On Main Canal, 1 mile South of Carlsbad, Carlsbad, Eddy County, NM

  18. 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 Dam operations and other management actions to protect resources downstream of Glen Canyon...

  19. 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... other management actions to protect resources downstream of Glen Canyon Dam, consistent with the...

  20. 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... other management actions to protect resources downstream of Glen Canyon Dam, consistent with the...

  1. 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... other management actions to protect resources downstream of Glen Canyon Dam, consistent with the...

  2. 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... other management actions to protect resources downstream of Glen Canyon Dam, consistent with the...

  3. 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... other management actions to protect resources downstream of Glen Canyon Dam, consistent with the...

  4. 5. DARK CANYON SIPHON Photographic copy of historic photo, ...

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

    5. DARK CANYON SIPHON - Photographic copy of historic photo, November 11, 1906 (original print located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) photographer unknown 'LOWER END OF DARK CANYON SIPHON CONSTRUCTION' - Carlsbad Irrigation District, Dark Canyon Siphon, On Main Canal, 1 mile South of Carlsbad, Carlsbad, Eddy County, NM

  5. 27 CFR 9.152 - Malibu-Newton Canyon.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Malibu-Newton Canyon. 9... Malibu-Newton Canyon. (a) Name. The name of the viticultural area described in this petition is “Malibu-Newton Canyon.” (b) Approved maps. The appropriate map for determining the boundary of the...

  6. 27 CFR 9.152 - Malibu-Newton Canyon.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Malibu-Newton Canyon. 9... Malibu-Newton Canyon. (a) Name. The name of the viticultural area described in this petition is “Malibu-Newton Canyon.” (b) Approved maps. The appropriate map for determining the boundary of the...

  7. 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.

  8. Uranium-series age determination of calcite veins, VC-1 drill core, Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Sturchio, Neil C.; Binz, Carl M.

    1988-06-01

    Uranium-series analysis (238U-234U-230Th) of 13 calcite veins from the hydrothermally altered Madera Limestone in the VC-1 drill core was performed to determine the ages of the veins and their relation to the Valles hydrothermal system. Thermal water from VC-1 and two hot springs in San Diego Canyon was analyzed for U and (234U/238U) to help evaluate the constancy of initial (234U/238U). The (230Th/234U) age of one of the veins is ˜95 kyr, and those of two other veins are ˜230 and ˜250 kyr. Five of the veins have near equilibrium (230Th/234U) and are probably older than ˜0.3 m.y. Uranium concentrations in the remaining veins are too low for analysis by the α-spectrometry techniques employed in this study. Of the five veins near (230Th/234U) equilibrium, four are also near (234U/238U) equilibrium, suggesting ages greater than ˜1.0 m.y., but one has (234U/238U) = 1.15, suggesting an age between ˜0.3 and ˜1.0 m.y. Calculated initial (234U/238U) of the veins yielding relatively young ages are neither equal to each other nor to (234U/238U) in thermal water from VC-1, indicating inconstancy of initial (234U/238U) that may be related to variations in groundwater mixing proportions. Three of the four veins that yield relatively young ages consist of coarse, sparry, vuggy calcite, suggesting that this may be the type of calcite vein which forms under conditions resembling those encountered presently in VC-1. The analytical data are consistent with closed-system behavior of U and Th in the VC-1 calcite veins.

  9. 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…

  10. 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.

  11. 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.

  12. 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....

  13. 77 FR 2533 - Boulder Canyon Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... 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, letters... Area Power Administration Boulder Canyon Project AGENCY: Western Area Power Administration, DOE....

  14. 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…

  15. Grand Canyon, Lake Powell, and Lake Mead

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A snowfall in the American West provides contrast to the landscape's muted earth tones and indicates changes in topography and elevation across (clockwise from top left) Nevada, Utah, Colorado, New Mexico, Arizona, and California. In Utah, the southern ranges of the Wasatch Mountains are covered in snow, and the Colorado River etches a dark ribbon across the red rock of the Colorado Plateau. In the center of the image is the reservoir created by the Glen Canyon Dam. To the east are the gray-colored slopes of Navaho Mountain, and to the southeast, dusted with snow is the region called Black Mesa. Southwest of Glen Canyon, the Colorado enters the Grand Canyon, which cuts westward through Arizona. At a deep bend in the river, the higher elevations of the Keibab Plateau have held onto snow. At the end of the Grand Canyon lies another large reservoir, Lake Mead, which is formed by the Hoover Dam. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  16. 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.

  17. 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…

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Fault Networks in the Northwestern Albuquerque Basin and Their Potential Role in Controlling Mantle CO2 Degassing and Fluid Migration from the Valles Caldera

    NASA Astrophysics Data System (ADS)

    Smith, J. R.; Crossey, L. J.; Karlstrom, K. E.; Fischer, T. P.; Lee, H.; McGibbon, C. J.

    2015-12-01

    The Rio Grande rift (RGR) has Quaternary and active volcanism and faulting that provide a field laboratory for examining links between mantle degassing and faults as fluid conduits. Diffuse and spring CO2 flux measurements were taken at 6 sites in the northwestern Albuquerque Basin (NWAB) and Valles caldera geothermal system. All sites progress to the southwest from the 1.25 Ma Valles caldera, down the rift-related Jemez fault network, to intersect with the Nacimiento fault system. Mantle CO2 and He degassing are well documented at 5 of 6 sites, with decreasing 3He/4He ratios away from the caldera. The instrument used to measure CO2 flux was an EGM-4 CO2 gas analyzer (PP systems) with an accumulation chamber. Carbonic springs at Penasco Springs (PS) and San Ysidro (SY), and the carbonate-cemented Sand Hill Fault (SHF) were targeted, all near the western border of the RGR. The SHF has no spring activity, had the smallest maximum flux of all the sites (8 g/m2d), but carbonate along the fault zone (<2 m wide) attest to past CO2 flux. The other two sites are equal distance (30-40 km) between the SHF site and Valles caldera sites. These sites have active carbonic springs that precipitate travertine mounds. Our work suggests these sites reflect intersections of the Nacimiento fault with NE trending faults that connect to the Jemez fault network. The maximum diffuse flux recorded at SY (297 g/m2d) and PS (25 g/m2d) are high, especially along the fault and near springs. At SY and PS the instruments capacity was exceeded (2,400 g/m2d) at 6 of 9 springs. Interpretations indicate a direct CO2 flux through a fault-related artesian aquifer system that is connected to magmatic gases from the caldera. Maximum diffuse flux measurements of Alamo Canyon (20,906 g/m2d), Sulphur Springs (2,400 g/m2d) and Soda Dam (1,882 g/m2d) at Valles caldera geothermal sites are comparable to Yellowstone geothermal systems. We use geospatial analysis and local geologic mapping to examine

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 3D View of Grand Canyon, Arizona

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Grand Canyon is one of North America's most spectacular geologic features. Carved primarily by the Colorado River over the past six million years, the canyon sports vertical drops of 5,000 feet and spans a 445-kilometer-long stretch of Arizona desert. The strata along the steep walls of the canyon form a record of geologic time from the Paleozoic Era (250 million years ago) to the Precambrian (1.7 billion years ago).

    The above view was acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard the Terra spacecraft. Visible and near infrared data were combined to form an image that simulates the natural colors of water and vegetation. Rock colors, however, are not accurate. The image data were combined with elevation data to produce this perspective view, with no vertical exaggeration, looking from above the South Rim up Bright Angel Canyon towards the North Rim. The light lines on the plateau at lower right are the roads around the Canyon View Information Plaza. The Bright Angel Trail, which reaches the Colorado in 11.3 kilometers, can be seen dropping into the canyon over Plateau Point at bottom center. The blue and black areas on the North Rim indicate a forest fire that was smoldering as the data were acquired on May 12, 2000.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (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 International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land

  10. 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

  11. Surprise and opportunity for learning in Grand Canyon: the Glen Canyon Dam Adaptive Management Program

    USGS Publications Warehouse

    Melis, Theodore S.; Walters, Carl; Korman, Josh

    2015-01-01

    With a focus on resources of the Colorado River ecosystem below Glen Canyon Dam, the Glen Canyon Dam Adaptive Management Program has included a variety of experimental policy tests, ranging from manipulation of water releases from the dam to removal of non-native fish within Grand Canyon National Park. None of these field-scale experiments has yet produced unambiguous results in terms of management prescriptions. But there has been adaptive learning, mostly from unanticipated or surprising resource responses relative to predictions from ecosystem modeling. Surprise learning opportunities may often be viewed with dismay by some stakeholders who might not be clear about the purpose of science and modeling in adaptive management. However, the experimental results from the Glen Canyon Dam program actually represent scientific successes in terms of revealing new opportunities for developing better river management policies. A new long-term experimental management planning process for Glen Canyon Dam operations, started in 2011 by the U.S. Department of the Interior, provides an opportunity to refocus management objectives, identify and evaluate key uncertainties about the influence of dam releases, and refine monitoring for learning over the next several decades. Adaptive learning since 1995 is critical input to this long-term planning effort. Embracing uncertainty and surprise outcomes revealed by monitoring and ecosystem modeling will likely continue the advancement of resource objectives below the dam, and may also promote efficient learning in other complex programs.

  12. 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

  13. 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.

  14. 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.

  15. Focusing of baroclinic tidal energy in a canyon

    NASA Astrophysics Data System (ADS)

    Vlasenko, Vasiliy; Stashchuk, Nataliya; Inall, Mark E.; Porter, Marie; Aleynik, Dmitry

    2016-04-01

    Strong three-dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celtic Sea is analyzed using observational data and numerical modeling. In a deep layer (500-800 m) in the center of the canyon, shear variance was elevated by an order of magnitude. Corresponding large vertical oscillations of deep isotherms and a local maximum of horizontal velocity were replicated numerically using the MITgcm. The elevated internal tidal activity in the deep part of the canyon is explained in terms of the downward propagation and focusing of multiple internal tidal beams generated at the shelf break. The near-circular shape of the canyon head and steep bottom topography throughout the canyon (steeper than the tidal beam) create favorable conditions for the lens-like focusing of tidal energy in the canyon's center. Observations and modeling show that the energy focusing greatly intensifies local diapycnal mixing that leads to local formation of a baroclinic eddy.

  16. 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.

  17. Shed Some Light on the Subject: Teaching Ramon del Valle-Inclan's "Luces de bohemia"

    ERIC Educational Resources Information Center

    Parker, Jason Thomas

    2011-01-01

    This essay seeks to provide parallel and interchangeable approaches to teaching Ramon del Valle-Inclan's challenging play "Luces de bohemia". A greater understanding of the cultural and mental frameworks of the early twentieth-century Spanish spectator will permit students to penetrate the dense intertextuality that characterizes Valle's…

  18. 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.

  19. Holocene sedimentary activity in a non-terrestrially coupled submarine canyon: Cook Strait Canyon system, New Zealand

    NASA Astrophysics Data System (ADS)

    Mountjoy, J. J.; Micallef, A.; Stevens, C. L.; Stirling, M. W.

    2014-06-01

    The Cook Strait Canyon system, located between the North and South islands of New Zealand, is a large (1800 km2), multi-branching, shelf-indenting canyon on an active subduction margin. The canyon comes within 1 km of the coast, but does not intercept fluvial or littoral sediment systems and is therefore defined as a non-terrestrially coupled system. Sediment transport associated with a strong tidal stream, and seafloor disturbance related to numerous high-activity faults, is known from previous studies. Little is known, however, about the rates of sedimentary activity in the canyon and the processes driving it. A substantial dataset of EM300 multibeam bathymetry, gravity cores, 3.5 kHz seismic reflection profiles, camera and video transects and current meter data have been collected across the region between 2002 and 2011. The canyon system therefore provides an excellent study area for understanding sediment transport in a non-coupled submarine canyon system. Analysis of the data reveals a two-staged sediment transport system where: (1) oceanographic (tidal) processes mobilise sediment from the continental shelf and transport it to depocentres in the upper-central canyons, and (2) tectonic (earthquake) processes remobilise sediment that is transported through the lower canyon to the deep ocean. Tidal boundary-layer currents within the canyon reach velocities up to 0.53 m/s and are capable of mobilising fine sand in the central reach of the upper canyons. The velocity is higher at the canyon rim and capable of mobilising coarse sand. Sediment depocentres resulting from this tidally forced sediment transport have a well formed geomorphology within the mid-upper canyon arms of Cook Strait and Nicholson Canyons. Pseudo-static stability modelling, supported by sediment core analysis, indicates that sediment accumulated in the upper canyons fails during seismic events approximately every 100 years. The 100 year return period ground shaking-level (peak ground

  20. Ventilation Processes in a Three-Dimensional Street Canyon

    NASA Astrophysics Data System (ADS)

    Nosek, Štěpán; Kukačka, Libor; Kellnerová, Radka; Jurčáková, Klára; Jaňour, Zbyněk

    2016-05-01

    The ventilation processes in three different street canyons of variable roof geometry were investigated in a wind tunnel using a ground-level line source. All three street canyons were part of an urban-type array formed by courtyard-type buildings with pitched roofs. A constant roof height was used in the first case, while a variable roof height along the leeward or windward walls was simulated in the two other cases. All street-canyon models were exposed to a neutrally stratified flow with two approaching wind directions, perpendicular and oblique. The complexity of the flow and dispersion within the canyons of variable roof height was demonstrated for both wind directions. The relative pollutant removals and spatially-averaged concentrations within the canyons revealed that the model with constant roof height has higher re-emissions than models with variable roof heights. The nomenclature for the ventilation processes according to quadrant analysis of the pollutant flux was introduced. The venting of polluted air (positive fluctuations of both concentration and velocity) from the canyon increased when the wind direction changed from perpendicular to oblique, irrespective of the studied canyon model. Strong correlations (>0.5) between coherent structures and ventilation processes were found at roof level, irrespective of the canyon model and wind direction. This supports the idea that sweep and ejection events of momentum bring clean air in and detrain the polluted air from the street canyon, respectively.

  1. 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

  2. Strategic guidelines for street canyon geometry to achieve sustainable street air quality—part II: multiple canopies and canyons

    NASA Astrophysics Data System (ADS)

    Chan, Andy T.; Au, William T. W.; So, Ellen S. P.

    The flow field and pollutant dispersion characteristics in a three-dimensional urban street canyon are investigated for various building array geometries. The street canyon in consideration is located in a multi-canopy building array that is similar to realistic estate situations. The pollutant dispersion characteristics are studied for various canopy aspect ratios, namely: the canyon height to width ratio, canyon length to height ratio, canyon breadth ratio and crossroad locations are studied. A three-dimensional field-size canyon has been analysed through numerical simulations using k- ɛ turbulence model. As expected, the wind flow and mode of pollutant dispersion is strongly dependent on the various flow geometric configurations and that the results can be different from that of a single canyon system. For example, it is found that the pollutant retention value is minimum when the canyon height-to-width ratio is approximately 0.8, or that the building height ratio is 0.5. Various rules of thumbs on urban canyon geometry have been established for good pollutant dispersion.

  3. Microthermometry of fluid inclusions from the VC-1 core hole in Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Sasada, Masakatsu

    1988-06-01

    Fluid inclusions in vein quartz and calcite from core samples of the VC-1 hole were studied with microscope heating/freezing and crushing stages. All samples originate from hydrothermally altered Paleozoic rocks predating formation of the Jemez Mountains volcanic field and Valles caldera. Most homogenization temperatures (Th) of the liquid-rich inclusions are above the present well temperature, but some Th of primary inclusions from 515 m and those of secondary inclusions from 723 m fit the present well temperature curve measured 10 months after completion of the well. The maximum temperature recorded by the primary inclusions is 275°C from hydrothermal quartz in the Sandia Formation at 811-m depth. The total range of Th for samples from several depths (90°C) indicates cooling from the maximum temperature. The salinity of fluid inclusions in hydrothermal quartz and calcite is generally low, <1 wt % NaCl eq. High-salinity fluid, up to 5 wt % NaCl eq, has been found in several calcite veins from the lower part of the Madera Limestone. The salinity decreases with decrease of Th of the secondary inclusions, and that with lowest Th at the lower part of the Madera Limestone is similar to those from the other depths. These data show that early hot water circulation system involved several types of fluid, whereas the later one was a homogeneous fluid. The salinity of fluid inclusions in detrital quartz (presumably inherited inclusions) is higher than that in hydrothermal minerals. Some of these inclusions show extraordinary low temperatures of final melting point of ice (about -40°C), suggesting that a CaCl2 component is present. CO2 contents in fluid inclusions were estimated by the bubble behavior on crushing. Crushing results indicate that CO2 content of the early fluid is ≧0.35 wt %, and that of the later fluid is ˜0.2-0.3 wt %. Geothermal fluid trapped in the fluid inclusions representing the present temperature regime is comparable in composition to those from

  4. Uranium-series age determination of calcite veins, VC-1 drill core, Valles Caldera, New Mexico

    SciTech Connect

    Sturchio, N.C.

    1988-06-10

    Uranium-series analysis (/sup 238/U--/sup 234/U--/sup 230/Th) of 13 calcite veins from the hydrothermally altered Madera Limestone in the VC-1 drill core was performed to determine the ages of the veins and their relation to the Valles hydrothermal system. Thermal water from VC-1 and two hot springs in San Diego Canyon was analyzed for U and (/sup 234/U//sup 238/U) to help evaluate the constancy of initial (/sup 234/U//sup 238/U). The (/sup 230/Th//sup 234/U) age of one of the veins is /similar to/95 kyr, and those of two other veins are /similar to/230 and /similar to/250 kyr. Five of the veins have near equilibrium (/sup 230/Th//sup 234/U) and are probably older than /similar to/0.3 m.y. Uranium concentrations in the remaining veins are too low for analysis by the ..cap alpha..-spectrometry techniques employed in this study. Of the five veins near (/sup 230/Th//sup 234/U) equilibrium, suggesting ages greater than /similar to/1.0 m.y., but one has (/sup 234/U//sup 238/U) = 1.15, suggesting an age between /similar to/0.3 and /similar to/1.0 m.y. Calculated initial (/sup 234/U//sup 238/U) of the veins yielding relatively young ages are neither equal to each other nor to (/sup 234/U//sup 238/U) in thermal water from VC-1, indicating inconstancy of initial (/sup 234/U//sup 238/U) tht may be related to variations in groundwater mixing proportions. Three of the four veins that yield relatively young ages consist of coarse, sparry, vuggy calcite, suggesting that this may be the type of calcite vein which forms under conditions resembling those encountered presently in VC-1. The analytical data are consistent with closed-system behavior of U and Th in the VC-1 calcite veins. copyright American Geophysical Union 1988

  5. MOLA Global roughness map of Mars

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The median of slopes in 35-km windows indicate the typical roughness on 300-meter baselines. The rougher nature of the heavily cratered terrain in the Southern Hemisphere is apparent, as well as that of Valles Marineris (12S, 289E) canyon walls and the Olympus Mons (18N, 227E) aureole deposits. The Northern Lowlands are smooth, especially Amazonis Planitia (16N, 202E), a region to the west of Olympus Mons, were typical median slopes on these baselines are often smaller than 0.1 degree. A shaded relief map of the topography is overlaid is monochrome.

  6. Center is at Latitude 30 Degrees South, Longitude 90 Degrees

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Center of the orthographic projection is at latitude 30 degrees S., longitude 90 degrees. The top half is dominated by the Tharsis Montes volcanoes, the large Alba Patera shield volcano, the dark Chryse basin, and a vast canyon system, Valles Marineris. In the central part, a prominent physiographic feature, Thaumasia plateau, includes a complex array of small- and large-scale faults and ridges and ancient volcanoes. The large conspicuous Argyre basin, southeast of the Thaumasia plateau, contains a broad expanse of light-colored plains 800 km across. The permanent south polar ice cap is located near the bottom.

  7. Grant Canyon oil field, Nye County, Nevada

    SciTech Connect

    Duey, H.D.; Veal, H.K.; Bortz, L.C.; Foster, N.H.

    1988-03-01

    The Grant Canyon field is located on the east side of Railroad Valley, Nevada, 8 mi south of the Eagle Springs oil field. The discovery well, 1 Grant Canyon Unit (SW1/4NW1/4, Sec. 21, T7S, T57E), was completed by Northwest Exploration Company on September 11, 1983, flowing 1816 BOPD, probably from the Devonian Simonson Dolomite (4375-4448 ft). Two additional wells have been completed in the field. Cumulative oil production through December 31, 1986, is 5,260,430 bbl of oil. During December 1986, wells 3 and 4 flowed an average of 5189 BOPD. Well 4 averaged 4065 BOPD for a recent month. The discovery well has been shut-in. The productive area is about 240 ac. The trap is a high fault block in the boundary fault zone that separates Railroad Valley from the Grant Range to the east. The Devonian Simonson reservoir is an intensely fractured, vuggy dolomite with some intercrystalline porosity. The top seal is the Tertiary valley fill, which unconformably overlies the Simonson Dolomite. The oil column is about 400 ft and the field apparently has an active water drive, inasmuch as the 1 Grant Canyon Unit had to be shut-in because of water production. The oil is black, 26/sup 0/API gravity, with a pour point of 10/sup 0/F and 0.5% sulfur. Estimated ultimate recoverable oil reserves are 13,000,000 bbl. The adjacent Bacon Flat field is a one-well field (SW1/4SW1/4, Sec. 17, T7N, R57E) that was completed by Northwest Exploration Company on July 5, 1981, for 200 BOPD and 1050 BWPD from the Devonian Guilmette Limestone (5316-5333 ft). Cumulative production through December 31, 1986, was 209,649 bbl of oil. This well averaged 215 BOPD during December 1986.

  8. 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...

  9. 4. VISTA POINT AND INTERPRETIVE PLAQUE AT LEE VINING CANYON. ...

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

    4. VISTA POINT AND INTERPRETIVE PLAQUE AT LEE VINING CANYON. NOTE ROAD CUT ON CANYON WALL. LOOKING NNE. GIS: N-37 56 30.3 / 119 13 44.8 - Tioga Road, Between Crane Flat & Tioga Pass, Yosemite Village, Mariposa County, CA

  10. 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. 7.4 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....

  11. 36 CFR 7.4 - Grand Canyon National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 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 Canyon National Park. (a) Commercial passenger-carrying motor vehicles....

  12. 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)...

  13. 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

  14. 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.

  15. 20140430_Green Machine Florida Canyon Hourly Data

    SciTech Connect

    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.

  16. 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

  17. Green Machine Florida Canyon Hourly Data

    DOE Data Explorer

    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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  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. 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.

  5. Dispersion and photochemical evolution of reactive pollutants in street canyons

    NASA Astrophysics Data System (ADS)

    Kwak, Kyung-Hwan; Baik, Jong-Jin; Lee, Kwang-Yeon

    2013-05-01

    Dispersion and photochemical evolution of reactive pollutants in street canyons with canyon aspect ratios of 1 and 2 are investigated using a computational fluid dynamics (CFD) model coupled with the carbon bond mechanism IV (CBM-IV). Photochemical ages of NOx and VOC are expressed as a function of the NO2-to-NOx and toluene-to-xylene ratios, respectively. These are found to be useful for analyzing the O3 and OH oxidation processes in the street canyons. The OH oxidation process (O3 oxidation process) is more pronounced in the upper (lower) region of the street canyon with a canyon aspect ratio of 2, which is characterized by more (less) aged air. In the upper region of the street canyon, O3 is chemically produced as well as transported downward across the roof level, whereas O3 is chemically reduced in the lower region of the street canyon. The O3 chemical production is generally favorable when the normalized photochemical ages of NOx and VOC are larger than 0.55 and 0.28, respectively. The sensitivities of O3 chemical characteristics to NOx and VOC emission rates, photolysis rate, and ambient wind speed are examined for the lower and upper regions of the street canyon with a canyon aspect ratio of 2. The O3 concentration and the O3 chemical production rate divided by the O3 concentration increase as the NOx emission rate decreases and the VOC emission rate and photolysis rate increase. The O3 concentration is less sensitive to the ambient wind speed than to other factors considered. The relative importance of the OH oxidation process compared to the O3 oxidation process increases with increasing NOx emission rate and photolysis rate and decreasing VOC emission rate. In this study, both O3 and OH oxidation processes are found to be important in street-canyon scale chemistry. The methodology of estimating the photochemical ages can potentially be adopted to neighborhood scale chemistry.

  6. Active geologic processes in Barrow Canyon, northeast Chukchi Sea

    USGS Publications Warehouse

    Eittreim, S.; Grantz, A.; Greenberg, J.

    1982-01-01

    Circulation patterns on the shelf and at the shelf break appear to dominate the Barrow Canyon system. The canyon's shelf portion underlies and is maintained by the Alaska Coastal Current (A.C.C.), which flows northeastward along the coast toward the northeast corner of the broad Chukchi Sea. Offshelf and onshelf advective processes are indicated by oceanographic measurements of other workers. These advective processes may play an important role in the production of bedforms that are found near the canyon head as well as in processes of erosion or non-deposition in the deeper canyon itself. Coarse sediments recovered from the canyon axis at 400 to 570 m indicate that there is presently significant flow along the canyon. The canyon hooks left at a point north of Point Barrow where the A.C.C. loses its coastal constriction. The left hook, as well as preferential west-wall erosion, continues down to the abyssal plain of the Canada Basin at 3800 m. A possible explanation for the preferential west-wall erosion along the canyon, at least for the upper few hundred meters, is that the occasional upwelling events, which cause nutrient-rich water to flow along the west wall would in turn cause larger populations of burrowing organisms to live there than on the east wall, and that these organisms cause high rates of bioerosion. This hypothesis assumes that the dominant factor in the canyon's erosion is biological activity, not current velocity. Sedimentary bedforms consisting of waves and furrows are formed in soft mud in a region on the shelf west of the canyon head; their presence there perhaps reflects: (a) the supply of fine suspended sediments delivered by the A.C.C. from sources to the south, probably the Yukon and other rivers draining northwestern Alaska; and (b) the westward transport of these suspended sediments by the prevailing Beaufort Gyre which flows along the outer shelf. ?? 1982.

  7. 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.

  8. Morphology, distribution, and development of submarine canyons on the United States Atlantic continental slope between Hudson arid Baltimore Canyons

    NASA Astrophysics Data System (ADS)

    Twichell, David C.; Roberts, David G.

    1982-08-01

    The distribution and morphology of submarine canyons off the eastern United States between Hudson and Baltimore Canyons have been mapped by long-range sidescan sonar. In this area canyons are numerous, and their spacing correlates with overall slope gradient; they are absent where the gradient is less than 3°, are 2 to 10 km apart where the gradient is 3° to 5°, and are 1.5 to 4 km apart where the gradient exceeds 6°. Canyons range from straight to sinuous; those having sinuous axes indent the edge of the continental shelf and appear to be older than those that head on the upper slope and have straighter axes. A difference in canyon age would suggest that canyons are initiated on the continental slope and only with greater age erode headward to indent the shelf. Shallow gullies on the middle and upper slope parts of the canyon walls suggest that submarine erosion has been a major process in a recent phase of canyon development. *Present address: British Petroleum, Moorgate, London EC2Y 9BU, England

  9. An overview of the Valles Caldera National Preserve: the natural and cultural resources

    USGS Publications Warehouse

    Parmenter, Robert R.; Steffen, Anastasia; Allen, Craig D.

    2007-01-01

    The Valles Caldera National Preserve is one of New Mexico’s natural wonders and a popular area for public recreation, sustainable natural resource production, and scientific research and education. Here, we provide a concise overview of the natural and cultural history of the Preserve, including descriptions of the ecosystems, flora and fauna. We note that, at the landscape scale, the Valles caldera appears to be spectacularly pristine; however, humans have extracted resources from the Preserve area for many centuries, resulting in localized impacts to forests, grasslands and watersheds. The Valles Caldera Trust is now charged with managing the Preserve and providing public access, while preserving and restoring these valuable public resources.

  10. Atmospheric Fragmentation of the Canyon Diablo Meteoroid

    NASA Technical Reports Server (NTRS)

    Pierazzo, E.; Artemieva, N. A.

    2005-01-01

    About 50 kyr ago the impact of an iron meteoroid excavated Meteor Crater, Arizona, the first terrestrial structure widely recognized as a meteorite impact crater. Recent studies of ballistically dispersed impact melts from Meteor Crater indicate a compositionally unusually heterogeneous impact melt with high SiO2 and exceptionally high (10 to 25% on average) levels of projectile contamination. These are observations that must be explained by any theoretical modeling of the impact event. Simple atmospheric entry models for an iron meteorite similar to Canyon Diablo indicate that the surface impact speed should have been around 12 km/s [Melosh, personal comm.], not the 15-20 km/s generally assumed in previous impact models. This may help explaining the unusual characteristics of the impact melt at Meteor Crater. We present alternative initial estimates of the motion in the atmosphere of an iron projectile similar to Canyon Diablo, to constraint the initial conditions of the impact event that generated Meteor Crater.

  11. 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

  12. 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.

  13. 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.

  14. Upper Los Alamos canyon fact sheet

    SciTech Connect

    Berger, Jeffrey H

    2007-01-01

    Los Alamos National Laboratory is planning to make environmental assessments in portions of Upper Los Alamos Canyon. Upper Los Alamos Canyon is one of the areas included in the 2005 Consent Order agreed to by Los Alamos National Laboratory, the National Nuclear Security Administration, and the New Mexico Environment Department. As such, it must be evaluated for potential contamination. The area is located within and south of the Los Alamos townsite in Technical Areas 00, 01, 03, 32, 41, 43, and 61 of Los Alamos National Laboratory and includes a total of 115 solid waste management units and areas of concern. This area was home to some of the earliest operations at Los Alamos, dating from the 1940s. Of the 115 solid-waste management units and areas of concern, 54 have been addressed previously. The remaining 61 are the focus of this project. These include septic tanks and outfalls, sanitary and industrial waste lines, storm drains, soil contamination areas, landfill and surface disposal areas, transformer sites, and incinerators. The Consent Order requires the Laboratory to evaluate historical work sites for the potential presence of residual contamination. It also requires the Laboratory to identify and implement corrective actions should contamination be found. The Laboratory began performing these types of activities in the 1990s. The Upper Los Alamos Canyon project entails: (1) collecting soil and rock samples using the most efficient and least-invasive methods practicable; (2) defining the nature and extent of any residual contamination associated with each solid waste management unit or area of concern; and (3) gathering additional data if needed to evaluate potential remedial alternatives. A variety of methods, including studies of engineering drawings, nonintrusive geophysical surveys, and trenching, may be used to identify the final sampling locations. The field team then determines which collection method to use at each location, based on such site

  15. Energy integrated farm system: Del Valle Hog Farm

    SciTech Connect

    Not Available

    1984-01-01

    The Del Valle Hog Farm, a Texas hog farm with grain crops, is designed to conserve energy through methane generation, alcohol production, and efficient use of electrical energy. The integrated energy concepts to be demonstrated are: methane generation from swine manure to produce electricity and heat for alcohol fermentation and distillation and to produce hot water for heating the digester reactors and the hog feeding pens; and alcohol production from milo and distillation of 170 proof alcohol by use of methane and generated electricity. Specific energy technologies to be implemented are: anaerobic digester; gas compressors to store methane for peak demands; engine generator powered by methane; waste-heat exchanger on engine generator to produce hot water; continuous-process alcohol facility to produce 24 gal/day; and crop management.

  16. Liquid-filled Canyons on Titan

    NASA Astrophysics Data System (ADS)

    Poggiali, Valerio; Mastrogiuseppe, Marco; Hayes, Alexander; Seu, Roberto; Birch, Samuel; Lorenz, Ralph; Grima, Cyril; Kargel, Jeffrey; Hofgartner, Jason

    2016-04-01

    During a close flyby, Cassini's RADAR altimeter observed a system of channels pertaining to the Vid Flumina system that drain into Titan's Ligeia Mare. While SAR images have been used to identify fluvial valleys in networks that extend for hundreds of kilometers, they can't directly prove the presence and/or physical extent of liquid channels filling them. Analysis of altimeter echoes shows that the channels are located in deep (~500 m) canyons and have strongly specular surface reflections that indicate they are currently liquid-filled. Liquid elevations in Vid Flumina and its lower tributaries are at the same level of Ligeia Mare to within the altimeter's vertical accuracy of ~15m, which is a function of both the RADAR instrument as well as the precision of Cassini's reconstructed ephemeris. Specular reflections are also observed in higher order tributaries that occur hundred meters above the level of Ligeia Mare, consistent with drainage feeding into the main channel system.

  17. Pollen taphonomy in a canyon stream

    NASA Astrophysics Data System (ADS)

    Fall, Patricia L.

    1987-11-01

    Surface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae- Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

  18. Compositional range in the Canyon Diablo meteoroid

    NASA Astrophysics Data System (ADS)

    Wasson, John T.; Ouyang, Xinwei

    1990-11-01

    The compositional range within the Canyon Diablo (CD) iron meteorites associated with the formation of the Meteor Crater (Arizona) was examined, using the INAA to analyze a set of CD samples consisting of nine irons collected within 7 km of the Meteor Crater, four Arizona IAB irons that were identified by Wasson (1968) as transported CD fragments, and irons from Las Vegas (Nevada) and Moab (Utah) that Buchwald (1975) suggested to be transported CD fragments. Results show that the irons named Helt Township, Idaho, Las Vegas, Mamaroneck, Moab, and Pulaski County are, most likely, mislabeled CD specimens. On the other hand, meteorites named Alexander County, Allan Hills A77283, Ashfork, Fairfield, and Rifle are identified as compositionally distinct independent falls.

  19. Compositional range in the Canyon Diablo meteoroid

    NASA Technical Reports Server (NTRS)

    Wasson, John T.; Ouyang, Xinwei

    1990-01-01

    The compositional range within the Canyon Diablo (CD) iron meteorites associated with the formation of the Meteor Crater (Arizona) was examined, using the INAA to analyze a set of CD samples consisting of nine irons collected within 7 km of the Meteor Crater, four Arizona IAB irons that were identified by Wasson (1968) as transported CD fragments, and irons from Las Vegas (Nevada) and Moab (Utah) that Buchwald (1975) suggested to be transported CD fragments. Results show that the irons named Helt Township, Idaho, Las Vegas, Mamaroneck, Moab, and Pulaski County are, most likely, mislabeled CD specimens. On the other hand, meteorites named Alexander County, Allan Hills A77283, Ashfork, Fairfield, and Rifle are identified as compositionally distinct independent falls.

  20. 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

  1. Recent Canyon Heads at the Bosphorus Outlet

    NASA Astrophysics Data System (ADS)

    Lericolais, G.; Le Drezen, E.; Nouze, H.; Gillet, H.; Ergun, M.; Cific, G.; Avci, M.; Dondurur, D.; Okay, S.

    2002-12-01

    The Black and Marmara Seas have witnessed increased scientific interest in last decade due to improved cooperation between the riparian countries and western scientific institutions but also due to the controversy existing about the origin of the reconnection of the Black Sea and Mediterranean seas after the last Glacial Maximum and its ensuing sea level rise. The Black Sea is linked to the global ocean only through the Bosphorus-Dardanelles system of straits. The Bosphorus is narrow (0.76 to 3.6 km wide) and shallow (32 m) at the sill, restricting the two-way water exchange between the brackish Black Sea and the very saline Mediterranean Sea. The Bosphorus sill was responsible for the behaviour of the Black Sea during the global glaciations and deglaciations, during which the Black Sea level followed the global sea level changes as long as they were higher than the sill. When global sea level was lower than the Bosphorus sill the variations of the Black Sea level reflected specific regional climate conditions without being coupled to the ocean changes. Recent studies suggest that a rapid flooding event may have occurred in the Black Sea during the Holocene. In 1998, a French-Romanian survey collected 4500 km of high-resolution seismic profiles, multibeam bathymetry, and sediment cores on the northern margin of the Black Sea where the shelf is sufficiently wide to preserve ancient shorelines in the vicinity of the shelf edge. If rapid flooding occurred through the Bosphorus Strait to drown these shorelines, it should have created a cataract. In August 2002, the French research vessel "Le Suroit" equipped with a EM 300 multibeam echosounder and a TritonElics Chirp Sonar mapped the Bosphorus outlet at the shelf edge. The results show a large retrogressive canyon deeply incised into the shelf which can be followed landward towards the Bosphorus outlet. Coring on the shelf and in the canyon revealed mega-ripples of shell debris of recent origin.

  2. Grant Canyon oil field, Nye County, Nevada

    SciTech Connect

    Veal, H.K.; Duey, H.D.; Bortz, L.C.; Foster, N.H.

    1987-08-01

    The Grant Canyon field is located on the east side of Railroad Valley, 8 mi south of the Eagle Springs oil field. The discovery well, 1 Grant Canyon Unit (SW 1/4 NW 1/4, Sec. 21, T7S, R57E), was completed by Northwest Exploration Co. on September 11, 1983, flowing 1816 BOPD from the Devonian Simonson(.) dolomite (4374-4448 ft). Two additional wells have been completed in the field. Cumulative oil production through December 31, 1986, is 5,260,430 bbl of oil. During December 1986, wells 3 and 4 flowed an average of 5189 BOPD. Well 4 averaged 4065 BOPD for a recent monthly total. The discovery well (1) has been shut-in. The productive area is about 240 acres. The trap is a high fault block in the boundary fault zone that separates Railroad Valley from the Grant Range to the east. The Devonian Simonson(.) reservoir is an intensely fractured, vuggy dolomite with some intercrystalline porosity. The top seal is the Tertiary valley fill which unconformably overlies the Simonson(.) dolomite. The oil column is about 400 ft thick and the field apparently has an active water drive, inasmuch as the 1 Unit had to be shut-in because of water production. The oil is black, 26/sup 0/ API gravity, a pour point of 10/sup 0/F and 0.5% sulfur. Estimated ultimate recoverable oil reserves are 13,000,000 bbl of oil. The adjacent Bacon Flat field is a one-well field (SW 1/4 SW 1/4, Sec. 17, T7N, R57E) that was completed by Northwest Exploration Co. on July 5, 1981, for 200 BOPD and 1050 BWPD from the Devonian Guilmette(.) limestone (5316-5333 ft). Cumulative production through December 31, 1986, is 209,649 bbl of oil, and this well averaged 215 BOPD during December 1986.

  3. Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification

    USGS Publications Warehouse

    Fergason, Robin L.; Gaddis, Lisa R.; Rogers, A. D.

    2014-01-01

    The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates. The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies provide information about past environments that may have supported liquid water and may have been habitable. This work further defines the association and relationship between hematite-bearing materials and low albedo (presumably aeolian) deposits and layered materials, identifies physical characteristics that are strongly correlated with the presence of hematite, and refines hypotheses for the origin and post-emplacement modification (including transport) of these hematite-bearing and associated materials. There are only three regions surrounding Candor Mensa where hematite has been identified, even though morphologic properties are similar throughout the entire mensa. Three possible explanations for why hematite is only exposed in these regions include: (1) the topographic structure of the mensa walls concentrates hematite at the base of the layered deposits, influencing the ability to detect hematite from orbit; (2) the presence of differing amounts of “dark mantling material” and hematite-free erosional sediment; (3) the potential fracturing of the mensa and the influence of these structures on fluid flow and subsequent digenesis. The observations of hematite-bearing materials in this work support the hypothesis that hematite is eroding from a unit in the Candor Mensa interior layered deposits (ILD) and is being concentrated as a lag deposit adjacent to the lower layers of Candor Mensa and at the base in the form of dark aeolian material. Due to the similar geologic context associated with hematite-bearing and ILD materials throughout the Valles Marineris canyon system, the insight gained from studying these

  4. View of Inverted Siphon crossing Hot Water (or White) Canyon. ...

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

    View of Inverted Siphon crossing Hot Water (or White) Canyon. Looking northeast - Childs-Irving Hydroelectric Project, Irving System, Inverted Siphon, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  5. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Juan River upstream of Clay Hills pullout. (iv) On the Escalante River upstream of Coyote Creek. (v) On... in excess of flat wake speed on the Escalante River from Cow Canyon to Coyote Creek. (3)...

  6. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Juan River upstream of Clay Hills pullout. (iv) On the Escalante River upstream of Coyote Creek. (v) On... in excess of flat wake speed on the Escalante River from Cow Canyon to Coyote Creek. (3)...

  7. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Juan River upstream of Clay Hills pullout. (iv) On the Escalante River upstream of Coyote Creek. (v) On... in excess of flat wake speed on the Escalante River from Cow Canyon to Coyote Creek. (3)...

  8. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Juan River upstream of Clay Hills pullout. (iv) On the Escalante River upstream of Coyote Creek. (v) On... in excess of flat wake speed on the Escalante River from Cow Canyon to Coyote Creek. (3)...

  9. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Juan River upstream of Clay Hills pullout. (iv) On the Escalante River upstream of Coyote Creek. (v) On... in excess of flat wake speed on the Escalante River from Cow Canyon to Coyote Creek. (3)...

  10. 14. MAIN CANAL CANAL CHECKGATES, JUST BELOW DARK CANYON ...

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

    14. MAIN CANAL - CANAL CHECKGATES, JUST BELOW DARK CANYON SIPHON, VIEW TO NORTHEAST - Carlsbad Irrigation District, Main Canal, 4 miles North to 12 miles Southeast of Carlsbad, Carlsbad, Eddy County, NM

  11. INTERIOR VIEW OF GLINES CANYON POWERHOUSE FROM TOP OF ENTRANCE ...

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

    INTERIOR VIEW OF GLINES CANYON POWERHOUSE FROM TOP OF ENTRANCE STAIRS. PHOTO BY JET LOWE, HAER, 1995. - Elwha River Hydroelectric System, Glines Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

  12. 1. GENERAL VIEW OF SHOSHONE HYDROELECTRIC PLANT IN GLENWOOD CANYON, ...

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

    1. GENERAL VIEW OF SHOSHONE HYDROELECTRIC PLANT IN GLENWOOD CANYON, VIEW TO THE NORTHEAST ALONG U.S. 6 AND THE COLORADO RIVER. - Shoshone Hydroelectric Plant Complex, 60111 U.S. Highway 6, Garfield County, CO

  13. View of Nevada side of Colorado River Canyon showing US ...

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

    View of Nevada side of Colorado River Canyon showing US 93, Visitor Center parking lot, transmission lines, and static towers in background, view west - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  14. 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

  15. View of Nevada side of Colorado River Canyon showing US ...

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

    View of Nevada side of Colorado River Canyon showing US 93 in foreground, transmission towers and static towers in background, view west - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  16. View of Nevada side of Colorado River Canyon taken from ...

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

    View of Nevada side of Colorado River Canyon taken from Lower Portal Road looking up towards area where new bridge will be located, view northwest - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  17. View of the Colorado River Canyon showing lower portal road ...

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

    View of the Colorado River Canyon showing lower portal road in background taken from the rim of Hoover Dam, view south - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  18. View of Arizona side of Colorado River Canyon taken from ...

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

    View of Arizona side of Colorado River Canyon taken from Lower Portal Road looking up towards area where new bridge will be located, view northeast - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  19. 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...

  20. 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

  1. Bridge 213, view looking south in Lapwai Canyon at Milepost ...

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

    Bridge 21-3, view looking south in Lapwai Canyon at Milepost 21.42 - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 1. 'SANTA ANA RIVER IN SANTA ANA CANYON. ORANGE COUNTY.' ...

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

    1. 'SANTA ANA RIVER IN SANTA ANA CANYON. ORANGE COUNTY.' This is an oblique aerial view to the northeast taken from the northeast extremity of the canyon, showing, in the middle distance, the confluence of Chino Creek and the Santa Ana River, site of the future Prado Dam. File number written on negative: R & H 80 026. - Prado Dam, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  8. 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.

  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. 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.

  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. Is Canyon Width a Diagnostic Indicator of the Discharge of Megafloods on Earth and Mars?

    NASA Astrophysics Data System (ADS)

    Lapotre, M. G.; Lamb, M. P.

    2013-12-01

    On Earth, large floods have carved steep-walled and amphitheater-headed canyons from the Pleistocene (e.g. Box Canyon, ID) through the Holocene (e.g. Asbyrgi Canyon, Iceland), to historic times (e.g. Canyon Lake Gorge, TX). The geologic record on Mars suggests that similar floods have carved canyons by waterfall retreat about 3.5 billion years ago, when the red planet was wetter and possibly warmer. We currently lack robust paleo-hydraulic tools to reconstruct the discharge of ancient floods, especially on Mars where sediment sizes are obscured from observation. To address this issue, we hypothesize that the width of canyon escarpment is controlled by the hydraulics of the canyon-carving flood due to focusing of the flood into the canyon head. We compiled field data from multiple canyons and floods on Earth and Mars and show that there is a correlation between estimated flood discharge and canyon headwall width. To explore what sets this relationship, we identified five important parameters using dimensional analysis: the Froude number, the ratio of backwater length to canyon length, the ratio of backwater length to flood width, the ratio of canyon width to flood width, and the topographic slope upstream of the canyon. We used the hydraulic numerical modeling suite ANUGA to simulate overland flow over different canyon geometries and flood parameters to systematically explore the relative bed shear stresses along the canyon rim as a metric for flow focusing. Results show that canyons that exceed a certain length, scaling with the hydraulic backwater length, have shear stresses at their heads that are significantly higher than near the canyon mouth. Shear stresses along the rim of the canyon sidewalls are limited, in comparison to stresses along the canyon head, when the flood width is of the order of the backwater length. Flow focusing only occurs for subcritical flow. Together, these results suggest that canyons may only grow from a perturbation that is large

  14. 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.

  15. 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

  16. Active deformation in the northern Sierra de Valle Fértil, Sierras Pampeanas, Argentina

    NASA Astrophysics Data System (ADS)

    Ortiz, Gustavo; Alvarado, Patricia; Fosdick, Julie C.; Perucca, Laura; Saez, Mauro; Venerdini, Agostina

    2015-12-01

    The Western Sierras Pampeanas region in the San Juan Province is characterized by thick-skinned deformation with approximately N-S trending ranges of average heights of 2500 m and a high frequency occurrence of seismic activity. Its location to the east of the mainly thin-skinned tectonics of the Argentine Precordillera fold-and-thrust belt suggests that at 30°S, deformation is concentrated in a narrow zone involving these two morphostructural units. In this paper, we present new apatite (U-Th)/He results (AHe) across the northern part of the Sierra de Valle Fértil (around 30°S) and analyze them in a framework of thermochronologic available datasets. We found Pliocene AHe results for Carboniferous and Triassic strata in the northern Sierra de Valle Fértil consistent with the hypothesis of recent cooling and inferred erosional denudation concentrated along the northern end of this mountain range. Our analysis shows that this northern region may have evolved under different conditions than the central part of the Sierra de Valle Fértil. Previous studies have observed AHe ages consistent with Permian through Cretaceous cooling, indicating the middle part of the Sierra de Valle Fértil remained near surface before the Pampean slab subduction flattening process. Those studies also obtained ˜5 My cooling ages in the southern part of the Sierra de Valle Fértil, which are similar to our results in the northern end of the range. Taken together, these results suggest a pattern of young deformation in the northern and southern low elevation ends of the Sierra de Valle Fértil consistent with regions of high seismic activity, and Quaternary active faulting along the western-bounding thrust fault of the Sierra de Valle Fértil.

  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. Regional depositional history of the Miocene-Pleistocene Louisiana Slope, Green Canyon and Mississippi Canyon

    SciTech Connect

    Risch, D.L.; Chowdhury, A.N.; Hannan, A.E.

    1994-09-01

    A regional sequence-stratigraphic analysis was recently completed for the Tertiary slope sediments in Green Canyon, Ewing Bank, and Mississippi Canyon to provide a chronostratigraphic framework for basin reconstructions and predict lithofacies distributions of reservoir and seal rocks. Sixteen third-order sequences of lowstand deep-water deposits were interpreted for the middle Miocene-Pleistocene section. Thirty regional lithofacies maps were made of predominantly lowstand deposits showing the distribution of shale and sand-prone sediments, slumping, channel levee systems, and fan lobes based on distinctive seismic reflection and well log patterns. These maps were combined with isochrons of selected sequences to identify depositional fairways, depocenters, and paleosalt positions that constantly changed through time. Depositional trends were principally north to south but were also observed to be east-west as salt modified the gradient on the gently dipping slope. In some cases, the structural and stratigraphic trends could be projected under allochthonous tabular salt. Miocene channel and fan lobe sands were found concentrated on the middle-lower paleoslope across the study area. The sedimentation rate doubled (0.7 m/1000 yr) in the early-middle Pliocene, which caused large-scale salt movements and trapped sand-prone turbidites along the upper-middle slope. A four-fold decrease in sediment influx during the late Pliocene-early Pleistocene produced a stacked condensed section of four sequences over the eastern Louisiana slope. A return to rapid sedimentation (up to 2.1 m/1000 yr.) during the Pleistocene reactivated salt movements and depocenters in the Green Canyon, Ewing Bank, and Mississippi Trough areas.

  19. Regional depositional history of the miocene-pleistocene Louisiana slope, Green Canyon-Mississippi Canyon

    SciTech Connect

    Risch, D.L.; Choudhury, A.N.; Hannan, A.E.

    1994-12-31

    A regional sequence stratigraphic analysis was recently completed for the Tertiary slope sediments in Green Canyon, Ewing Bank, and Mississippi Canyon to provide a chronostratigraphic framework for basin reconstructions and to predict lithofacies distributions of reservoir and seal rocks. Sixteen third-order sequences of lowstand deepwater deposits were interpreted for the Middle Miocene-Pleistocene section. Thirty regional lithofacies maps were made of predominantly lowstand deposits showing the distribution of shale and sand-prone sediments, slumps, channel/levee systems, and fan lobes based on distinctive seismic reflection and well log patterns. These maps were combined with isochrons of selected sequences to identify depositional fairways, depocenters, and paleosalt positions that constantly changed through time. Depositional trends were principally north-south but were also observed to be east-west as salt modified the gradient on the gently dipping slope. In some cases, the structural and stratigraphic trends could be projected under allochthonous tabular salt. Miocene channel and fan lobe sands were concentrated on the middle-lower paleoslope across the study area. The sedimentation rate doubled to 2.3 m/1000 yr in the early Middle Pliocene, which caused large-scale salt movements and trapped sand-prone turbidities along the upper to middle slope. A four-fold decrease in sediment influx during the Late Pliocene-Early Pleistocene produced a stacked condensed section of four sequences over the eastern Louisiana slope. A return to rapid sedimentation (up to 6.9 m/1,000 yr) during the Late Pleistocene reactivated salt movements and depocenters in the Green Canyon, Ewing Bank, and Mississippi Trough areas.

  20. The bathypelagic community of Monterey Canyon

    NASA Astrophysics Data System (ADS)

    Robison, Bruce H.; Sherlock, Rob E.; Reisenbichler, Kim R.

    2010-08-01

    We used a quiet, deep-diving remotely operated vehicle (ROV) to conduct oblique, quantitative video transects of the bathypelagic fauna at depths between 1000 and 3500 m at a site over the Monterey Submarine Canyon, in the eastern North Pacific off central California. Fifteen such dives were made over a two-year period. Analyses of the video data revealed a rich and diverse fauna dominated by gelatinous animals. In particular, the holopelagic polychaete Poeobius meseres was an important detritivore in the upper half of this depth range. As Poeobius abundance eventually declined with increasing depth, larvacean abundance increased. In contrast, the relative numbers of crustacean grazers, principally copepods and mysids, remained relatively constant with depth. Medusae were most abundant and most diverse among the gelatinous predators, which also included ctenophores, and siphonophores. Chaetognaths occurred chiefly in the upper half of the depth range. While there is considerable overlap, the bathypelagic fauna can be separated into upper (1000 to 2300 m) and lower (2400 to 3300 m) zones, as well as a distinct and populous benthic boundary layer. Within the overall bathypelagic community is a complex web of trophic links involving gelatinous predators that feed on both gelatinous and hard-bodied particle feeders, as well as on each other. The amount of organic carbon contained in this jelly web is substantial but its ecological fate is uncertain. The assessment of bathypelagic communities will be important for establishing baselines to conserve deep pelagic biodiversity within high-seas protected areas.

  1. Circulation in Vilkitsky Canyon in the eastern Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Janout, Markus; Hölemann, Jens

    2016-04-01

    The eastern Arctic Ocean is characterized by steep continental slopes and vast shallow shelf seas that receive a large amount of riverine freshwater from some of the largest rivers on earth. The northwestern Laptev Sea is of particular interest, as it is a freshwater transport pathway for a swift surface-intensified current from the Kara Sea toward the Arctic Basin, as was recently highlighted by high-resolution model studies. The region features complex bathymetry including a narrow strait and a large submarine canyon, strong tides, polynyas and severe sea ice conditions throughout much of the year. A year-long mooring record as well as detailed hydrographic shipboard measurements resulted from summer expeditions to the area in 2013 and 2014, and now provide a detailed picture of the region's water properties and circulation. The hydrography is characterized by riverine Kara Sea freshwater near the surface in the southern part of the canyon, while warmer (~0°C) saline Atlantic-derived waters dominate throughout the canyon at depths >150m. Cold shelf-modified waters near the freezing point are found along the canyon edges. The mean flow at the 300 m-deep mooring location near the southern edge of the canyon is swift (30 cm/s) and oriented eastward near the surface as suggested by numerical models, while the deeper flow follows the canyon topography towards the north-east. Wind-driven deviations from the mean flow coincide with sudden changes in temperature and salinity. This study characterizes the general circulation in Vilkitsky Canyon and investigates its potential as a conduit for upwelling of Atlantic-derived waters from the Arctic Basin to the Laptev Sea shelf.

  2. 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.

  3. 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.

  4. MEVTV workshop on tectonic features on Mars

    SciTech Connect

    Watters, T.R.; Golombek, M.P.

    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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Geomorphology and Mapping of Canyon Lake Gorge from Flood Events

    NASA Astrophysics Data System (ADS)

    Gunawan, A. P.

    2015-12-01

    A large volume of runoff causes flood that exceed the capacity of flood control reservoir. Canyon Lake Gorge, Canyon Lake, TX was formed as a result of a major erosional event in 2002. A low-pressure system combined with a flow of tropical air hit over central Texas causing precipitation, recent flooding in 2015 has changed the structure of the channel. Here, channel changes in the canyon are evaluated using hydrologic conductivity, ground penetrating radar (GPR), and photogrammetry. Mapping and field reconnaissance will be used to map out changes over the years of when the flood had occurred in the past (1998, 2002, and 2015) as well as to study the flood surrounding Canyon Lake Gorge and Guadalupe River. A demographic survey will be used to analyzed the damage that was caused by the flood and compare the severity of the event. The justification for this is that the Canyon Lake Gorge have a unique formation, geologic time scale before and after the flood has changed. The recent flood in 2015 gives an opportunity to study the changes that is currently occurring.

  11. 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.

  12. 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 Publishing 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...

  13. Software Configuration Management Plan for the B-Plant Canyon Ventilation Control System

    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 Software Configuration Management Plan provides instructions for change control of the CVCS.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 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. 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...

  3. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 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...

  4. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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...

  10. 75 FR 39147 - Establishment of Class E Airspace; Bryce Canyon, UT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-08

    ... Positioning System (GPS) Standard Instrument Approach Procedures (SIAPs) at Bryce Canyon Airport. This will... Bryce Canyon, UT (74 FR 59492). The comments received prompted the FAA on April 26, 2010, to publish in... airspace at Bryce Canyon, UT (75 FR 21532). Interested parties were invited to participate in...

  11. 78 FR 3879 - Ochoco National Forest, Paulina Ranger District; Oregon; Fox Canyon Cluster Allotment Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... Forest Service Ochoco National Forest, Paulina Ranger District; Oregon; Fox Canyon Cluster Allotment... Ranger District. The Fox Canyon Cluster project area is located approximately 35 miles east of Prineville, south of Big Summit Prairie. The four allotments are Antler, Brush Creek, Fox Canyon, and Gray...

  12. 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.

  13. Fluvial erosion of physically modeled abrasion-dominated slot canyons

    NASA Astrophysics Data System (ADS)

    Carter, Carissa L.; Anderson, Robert S.

    2006-11-01

    Abrasion-dominated fluvial erosion generates slot canyons in massive bedrock with intricately undulating walls. Flows in slot canyons are unusual in that the walls comprise a significant portion of the wetted perimeter of the flow during geomorphically effective floods. In Wire Pass, Utah, the upper Paria River incises through massive, crossbedded Navajo Sandstone. Incision in Wire Pass and related slots occurs only during flash floods; paleoflood debris indicates that the width/depth ratios of these flows are at times as low as 1:1. Submeter resolution field mapping of a 20-m length of Wire Pass shows that the wall morphology is a complicated combination of in-phase (meander-like) and out-of-phase (pinch and swell) undulations. In order to investigate evolution of slot canyons and the influence of their wall shapes on flow dynamics, we recorded the evolution of four distinct canyon wall morphologies in a 2.4 m flume box at the St. Anthony Falls Laboratory. In a substrate consisting of ˜ 3:2 mixtures of F110 sand and Plaster of Paris, we molded canyons with in-phase and out-of-phase undulations, and wide (6.5 cm) and narrow (4 cm) straight initial wall profiles. Discharges ranged from 1.4 L/s to 2.9 L/s, and wall and bed morphology were measured at 5 h intervals at 0.5 cm resolution. Results show efficient back-eddy erosion in the undulating canyon walls and related erosional bedforms in all channels created by vortices in the flow. Maximum filaments of velocity are depressed and asymmetric, and the implied shear stress distribution varied in space and time on the channel beds. Flow width/depth ratios strongly influence the flow structure and distribution of shear stress in a slot and appear to be a factor in dictating whether a bedrock channel widens its walls or incises its bed.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. BLANCO MOUNTAIN AND BLACK CANYON ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Diggles, Michael F.; Rains, Richard L.

    1984-01-01

    The mineral survey of the Blanco Mountain and Black Canyon Roadless Areas, California indicated that areas of probable and substantiated mineral-resource potential exist only in the Black Canyon Roadless Area. Gold with moderate amounts of lead, silver, zinc, and tungsten, occurs in vein deposits and in tactite. The nature of the geological terrain indicates little likelihood for the occurrence of energy resources in the roadless areas. Detailed geologic mapping might better define the extent of gold mineralization. Detailed stream-sediment sampling and analysis of heavy-mineral concentrations could better define tungsten resource potential.

  20. 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.

  1. 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.

  2. Thermopower signatures and spectroscopy of the canyon of conductance suppression

    NASA Astrophysics Data System (ADS)

    Kiršanskas, G.; Hammarberg, S.; Karlström, O.; Wacker, A.

    2016-07-01

    Interference effects in quantum dots between different transport channels can lead to a strong suppression of conductance, which cuts like a canyon through the common conductance plot [Phys. Rev. Lett. 104, 186804 (2010), 10.1103/PhysRevLett.104.186804]. In the present work we consider the thermoelectric transport properties of the canyon of conductance suppression using the second-order von Neumann approach. We observe a characteristic signal for the zeros of the thermopower. This demonstrates that thermoelectric measurements are an interesting complimentary tool to study complex phenomena for transport through confined systems.

  3. 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

  4. Travel Time Distribution Modeling in the Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Broxton, P. D.; Troch, P. A.; Brooks, P. D.; Lyon, S. W.; Gustafson, J. R.; Veatch, W. C.

    2007-12-01

    Modeling the transit times of catchment waters is of paramount importance in hydrology. The distribution of the time it takes for individual water molecules to move through a hydrologic system (a.k.a., the travel time distribution) is a fundamental characterization of a catchment. Travel time distributions are affected by a variety of physical characteristics of catchments (e.g., vegetation type, degree of soil development) that depend on the amount of solar energy the catchment receives. These characteristics, therefore, can be considered a function of aspect. The goal of this research is to constrain travel time distributions on a series of eight radial mountain streams having different slope aspects on Redondo Peak, a resurgent dome in the center of the Valles Caldera, near Los Alamos, New Mexico. Redondo Peak is an excellent natural laboratory for this type of experiment because all aspects are represented on different sides of the mountain while the internal geology and climate are relatively consistent. To model the transit time distributions of each catchment, variations of chemical load of the snowpack, isotopic compositions of meltwater samples, and snowcover distribution data from closely related studies are coupled with periodic stream and precipitation samples that are analyzed for stable water isotopes content. Additional information comes from a network of temperature sensors to monitor the distribution of snowmelt and headwater stream discharge as well as a series of flumes to capture the flows from the streams. The travel time distributions determined in this project provide a bottom up approach to verify catchment-scale models.

  5. Geotechnical Considerations of Canyon Formation: the Case of Cap de Creus Canyon, Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Sansoucy, M.; Locat, J.; Lee, H. J.

    2006-12-01

    A portion of the Cap de Creus has been selected for a detailed analysis of slope instability. The selected area is located on the north side of the Canyon between water depth ranging between 150 m and 750 m. This sector, which presents geomorphic evidences of landsliding, has been sampled at three different water depths along a line perpendicular to the axis of the canyon. These cores have been analyzed in order to determine the nature of the sediments along with their geotechnical and rheological properties. At the top of the slope, the geotechnical signature suggests that clay sediments are normally consolidated as a result of a regular and steady sedimentation. In contrast, a highly overconsolidated clayey sediment has been encountered in the core taken on the slope, about 60 m below the headwall escarpment which is about 30 m high with a slope of 27 degrees. The third sampling site is at the toe where the slope is 3 degrees. The geotechnical profile of this zone suggests that depositional events, such as debris flows and turbidity currents, occur frequently, under a more or less erosive regime. The geotechnical and rheological properties have been used for failure (sliding conditions) and post-failure analyses (mobility). The stability of the flank has been analyzed with Slope/W, using limit equilibrium methods. The analysis of the initial geometry with drained conditions indicates that the flank is stable, with a static safety factor of 1,7 (neglecting any seismic our excess pore pressure effects). Results of various scenarios on failure development have been tested, and show that axial incision appears to be the main process, largely as drained failures. Post-failure evolution has been modeled with Bing software. Final length and height of the deposit has been analyzed for different initial sliding mass geometries. The analysis has shown that the deposition of soft mudflow layers could only occur by considering superficial failures originating just above the

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Water-Temperature Data for the Colorado River and Tributaries Between Glen Canyon Dam and Spencer Canyon, Northern Arizona, 1988-2005

    USGS Publications Warehouse

    Voichick, Nicholas; Wright, Scott A.

    2007-01-01

    The regulation of flow of the Colorado River by Glen Canyon Dam began in 1963. This resulted in significant changes to the downstream ecosystem of the Colorado River in Grand Canyon, contributing to the initiation of the Glen Canyon Environmental Studies program in 1982, followed by establishment of the Glen Canyon Dam Adaptive Management Program in 1996. This report describes a water-temperature dataset collected through these programs for the reach of the Colorado River and selected tributaries between Glen Canyon Dam and Spencer Canyon (approximately 261 river miles) in northern Arizona from 1988 to 2005. The primary purposes of the report are to summarize the methods of data collection, processing, and editing; to present summary statistics; and to make the data described in the report available.

  12. 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

  13. 77 FR 32629 - Black Canyon Hydro, LLC; Notice of Intent To File License Application, Filing of Pre-Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... Energy Regulatory Commission Black Canyon Hydro, LLC; Notice of Intent To File License Application...-filing Process. b. Project No.: 14110-001. c. Date Filed: March 27, 2012. d. Submitted By: Black Canyon Hydro, LLC (Black Canyon). e. Name of Project: Black Canyon Hydroelectric Project. f. Location: On...

  14. 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.

  15. Frequency and initiation of debris flows in Grand Canyon, Arizona

    NASA Astrophysics Data System (ADS)

    Griffiths, Peter G.; Webb, Robert H.; Melis, Theodore S.

    2004-12-01

    Debris flows from 740 tributaries transport sediment into the Colorado River in Grand Canyon, Arizona, creating rapids that control its longitudinal profile. Debris flows mostly occur when runoff triggers failures in colluvium by a process termed "the fire hose effect." Debris flows originate from a limited number of geologic strata, almost exclusively shales or other clay-rich, fine-grained formations. Observations from 1984 through 2003 provide a 20 year record of all debris flows that reached the Colorado River in Grand Canyon, and repeat photography provides a 100 year record of debris flows from 147 tributaries. Observed frequencies are 5.1 events/year from 1984 to 2003, and historic frequencies are 5.0 events/year from 1890 to 1983. Logistic regression is used to model historic frequencies based on drainage basin parameters observed to control debris flow initiation and transport. From 5 to 7 of the 16 parameters evaluated are statistically significant, including drainage area, basin relief, and the height of and gradient below debris flow source areas, variables which reflect transport distance and potential energy. The aspect of the river channel, which at least partially reflects storm movement within the canyon, is also significant. Model results are used to calculate the probability of debris flow occurrence at the river over a century for all 740 tributaries. Owing to the variability of underlying geomorphic controls, the distribution of this probability is not uniform among tributaries of the Colorado River in Grand Canyon.

  16. 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.

  17. 36 CFR 7.19 - Canyon de Chelly National Monument.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Monument. 7.19 Section 7.19 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.19 Canyon de Chelly National Monument... accompanied by National Park Service employees or by authorized guides: Provided, however, That...

  18. College of the Canyons New Faculty Survey. Report #104.

    ERIC Educational Resources Information Center

    Dixon, P. Scott; Gribbons, Barry C.

    In 2001, the College of the Canyons (COC) (California) surveyed all faculty members hired between May 2000 and March 2001 to gather information about the experiences of newly hired faculty. Thirty-eight anonymous questionnaires (with both open- and closed-ended questions) were placed in the mailboxes of new faculty; 23 were completed and returned,…

  19. A scale model study of parallel urban street canyons

    NASA Astrophysics Data System (ADS)

    Hornikx, Maarten; Forssen, Jens; Kropp, Wolfgang

    2005-04-01

    The access to quiet areas in cities is of increasing importance. Recently, the equivalent sources method for a two dimensional situation of parallel urban street canyons has been developed. One canyon represents a busy road, whereas the other is one without traffic; the quiet side. With the model, the transfer function between the two canyons can be calculated, as well as the influence of diffusion, absorption, and atmospheric turbulence on the transfer function. A scale model study of two parallel canyons has now been executed. A scale of 1:40 has been chosen and the maximum length sequence technique has been applied using the MLSSA system. Results of the scale model study have been compared to calculations with the equivalent sources method. The difference between a two-dimensional and a three-dimensional quiet side, between a coherent and an incoherent line source and the influence of absorption and diffusion has been investigated. The scale model study also gives insight in the evolution of the sound field in the time domain. [Work supported by the Swedish Foundation for Strategic Environmental Research (MISTRA).

  20. A modeling of air flow in a street canyon

    NASA Astrophysics Data System (ADS)

    Nuterman, R. B.; Starchenko, Alexander V.

    2004-02-01

    Steady plane-parallel isothermal turbulent flow of a viscous incompressible liquid above a surface with elements of a roughness is considered. Buildings and road with vehicle emissions for a city canyon. Reynolds equations and Boussinesq assumption are used to solve the considered problem. We apply the no-slip boundary conditions on the rigid walls, simple gradient conditions on the upper and outflow boundaries and known distributions of flow parameters on inflow boundary. Turbulent parameters are calculated on the basis of "k--ɛ" model of turbulence with near-wall functions approach for energy of turbulence k and dissipation ɛ. A numerical solution of the problem is found with using of finite-volume method and the SIMPLE algorithm. Influence of atmospheric parameters on pollutant dispersion in a street canyon is investigated. Also influences of the geometrical factors of a city street canyon on a pattern of turbulent flow and distribution of harmful impurity concentration emitting from urban vehicles are investigated. The adverse meteorological situations resulting in accumulation of the harmful substances in street canyon are shown.

  1. Grand Canyon, Colorado as seen from STS-62

    NASA Technical Reports Server (NTRS)

    1994-01-01

    In this view, the Colorado River can be seen flowing southwest from top left to bottom center-right. The dark wider sections of the river are the water surface of Lake Powell (center, and top left), 110 miles long in a straight line. Grand Canyon National Monument lies lower right, centered on the Grand Canyon of the Colorado River, a 10 mile-wide gash carved more than 5,000 feet deep by the Colorado. The Canyon has cut into the Kaibab Plateau, an uplifted area visible here as a forested area with snow on the highest northern parts. The surrounding parts of the Colorado Plateau are sparsely occupied by brush vegetation and appear yellow-brown. The dark area top right is the wooded country of Black Mesa in Navajoland, divided from Lake Powell by the San Juan River. Four Corners is just outside the pictures (top) where the states of Arizona, Utah, Colorado and New Mexico meet. The Henry Mountains appear top left. Apart from Grand Canyon National Monument, several other famous national mo

  2. Context view from NE ridge of Daybreak Canyon running NE ...

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

    Context view from NE ridge of Daybreak Canyon running NE from lookout tower shows fire line on right and NE side of lookout tower in the far distance. Tree in foreground is Pondaross Pine that survived fires of 1991 and 1994. Camera is pointed SW with wide-angle lens. - Chelan Butte Lookout, Summit of Chelan Butte, Chelan, Chelan County, WA

  3. College of the Canyons Survey of Teaching Practices, Spring 1993.

    ERIC Educational Resources Information Center

    Mattice, Nancy J.; Richardson, Russell C.

    The Associate Program for Adjunct Faculty (APAF) at College of the Canyons (CC) in Santa Clarita, California, includes instructional skills workshops and advanced teaching workshops designed to promote good teaching practices among part-time faculty. In March 1993, CC conducted a survey of teaching practices among the college's 160 part-time…

  4. 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…

  5. 33. VIEW OF TIOGA ROAD DESCENDING LEE VINING CANYON. SAME ...

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

    33. VIEW OF TIOGA ROAD DESCENDING LEE VINING CANYON. SAME VIEW AS CA-149-3. LOOKING ESE. GIS: N-37 56 58.2 / W-119 13 28.1 - Tioga Road, Between Crane Flat & Tioga Pass, Yosemite Village, Mariposa County, CA

  6. Microorganisms from the late precambrian of the grand canyon, Arizona.

    PubMed

    Schopf, J W; Ford, T D; Breed, W J

    1973-03-30

    An assemblage of cellularly well-preserved, filamentous and spheroidal plant microfossils has been detected in a cherty pisolite bed of the late Precambrian Chuar Group from the eastern Grand Canyon of the Colorado River. This newly discovered microflora, probably among the youngest Precambrian biological communities now known, appears to be of both evolutionary and biostratigraphic significance. PMID:17835936

  7. 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

  8. 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

  9. 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...

  10. 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...

  11. Context view of Powerhouse from west slope of canyon showing ...

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

    Context view of Powerhouse from west slope of canyon showing west facade and inclined railroad tracks. View to east-southeast - Mystic Lake Hydroelectric Facility, Powerhouse, Along West Rosebud Creek, 1 3/4 miles northeast of Mystic Lake Dam, Fishtail, Stillwater County, MT

  12. Water's arrival to prompt drilling in Nevada's Grant Canyon field

    SciTech Connect

    Petzet, G.A.

    1991-08-12

    This paper reports that water has sharply reduced the oil flow in Nevada at what for several years has been the highest producing rate well in the Lower 48 states, and a well will be drilled in an attempt to reestablish higher oil flow rates. Apache Corp., which operates three well Grant Canyon field in Railroad Valley 65 miles southwest of Ely, staked two close in locations but plans to drill only one well. Estimates of the areal extent of the structure are from less than 200 acres to about 240 acres, making the new well a risky proposition. Grant Canyon field has been important ever since its discovery in 1983. Four authors involved in the field's discovery, in an exploration paper published in 1988, indicated that the field's ultimate reserves might be about 13 million bbl of black, 26{degrees} gravity crude oil with 0.5% sulfur and a pour point of 10{degrees} F. The producing zone is intensely fractured Devonian Guilmette dolomite at about 4,400 ft. Through February 1991 it had produced more than 8.7 million bbl through the 3 Grant Canyon and 5.1 million bbl through the 4 Grant Canyon. One well Bacon Flat field, a Guilmette reservoir in a separate, structurally lower fault block, is shut-in. It was discovered in 1981.

  13. 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...

  14. 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.

  15. 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…

  16. Properties of Saltstone Prepared Containing H-Canyon Waste

    SciTech Connect

    Cozzi, A

    2005-04-05

    Saltstone slurries were prepared from solutions made from H-Canyon waste and evaluated for processing properties. Salt solutions prepared with a 1:1 ratio of Tank 50H simulant and H-Canyon blended waste produced slurries that met the processing requirements in Table 2 of the Task Technical and Quality Assurance Plan (TTQAP). Additions of set retarder and antifoam were necessary to meet these processing requirements. The water to premix ratio used to achieve acceptable processing properties was 0.63. Slurries prepared solely with H-Canyon blended waste as the salt solution met the gel time and bleed water requirements, but did not set in the allotted time. Compressive strength samples prepared from the mix with acceptable processing properties had an average compressive strength of 814 psi (Samples with a compressive strength value of >200 psi are acceptable.). Analysis for mercury of the leachate of samples analyzed by the Toxic Characteristic Leaching Procedure (TCLP) indicated a concentration of mercury in the leachate <0.11 mg/L (The limit set by the Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) for mercury to require treatment is 0.2 mg/L.). It is recommended that without further testing; Tank 50H be limited to no more than 50 wt% H-Canyon material. It is also recommended that prior to the transfer of Tank 50H to the Saltstone Processing Facility; a sample of the Tank 50H waste be evaluated for processing properties.

  17. 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.

  18. 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.

  19. 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.

  20. 78 FR 35640 - Establishment of the Valle de Oro National Wildlife Refuge, Bernalillo County, New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-13

    ... additional funds to acquire lands, waters, or interest therein for fish and wildlife conservation purposes... Fish and Wildlife Service Establishment of the Valle de Oro National Wildlife Refuge, Bernalillo County, New Mexico AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice. SUMMARY: This notice...

  1. 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.

  2. 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.

  3. The first report of the aphids of the Valles Caldera National Preserve, New Mexico, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report 50 species, belonging to 26 genera of aphids (Hemiptera: Aphididae), collected within and near the boundary of the Valles Caldera National Preserve in the Jemez Mountains of northern New Mexico, USA. Of these, 35 (70%) represent new distribution records for New Mexico. Plant genera/species...

  4. 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

  5. Geologic framework of thermal springs, Black Canyon, Nevada and Arizona

    USGS Publications Warehouse

    Beard, L. Sue; Anderson, Zachary W.; Felger, Tracey J.; Seixas, Gustav B.

    2014-01-01

    Thermal springs in Black Canyon of the Colorado River, downstream of Hoover Dam, are important recreational, ecological, and scenic features of the Lake Mead National Recreation Area. This report presents the results from a U.S. Geological Survey study of the geologic framework of the springs. The study was conducted in cooperation with the National Park Service and funded by both the National Park Service and National Cooperative Geologic Mapping Program of the U.S. Geological Survey. The report has two parts: A, a 1:48,000-scale geologic map created from existing geologic maps and augmented by new geologic mapping and geochronology; and B, an interpretive report that presents results based on a collection of fault kinematic data near springs within Black Canyon and construction of 1:100,000-scale geologic cross sections that extend across the western Lake Mead region. Exposures in Black Canyon are mostly of Miocene volcanic rocks, underlain by crystalline basement composed of Miocene plutonic rocks or Proterozoic metamorphic rocks. The rocks are variably tilted and highly faulted. Faults strike northwest to northeast and include normal and strike-slip faults. Spring discharge occurs along faults intruded by dacite dikes and plugs; weeping walls and seeps extend away from the faults in highly fractured rock or relatively porous volcanic breccias, or both. Results of kinematic analysis of fault data collected along tributaries to the Colorado River indicate two episodes of deformation, consistent with earlier studies. The earlier episode formed during east-northeast-directed extension, and the later during east-southeast-directed extension. At the northern end of the study area, pre-existing fault blocks that formed during the first episode were rotated counterclockwise along the left-lateral Lake Mead Fault System. The resulting fault pattern forms a complex arrangement that provides both barriers and pathways for groundwater movement within and around Black

  6. 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.

  7. Giant Scours on the Eel Canyon Fan

    NASA Astrophysics Data System (ADS)

    Lundsten, E.; Caress, D. W.; Paull, C. K.; Thomas, H.; Anderson, K.; Gwiazda, R.

    2011-12-01

    Previously available surface vessel multi-beam data collected on the deep-sea fan directly down channel from the mouth of Eel Canyon off of Northern California show a train of at least 8 giant elongated asymmetric depressions that look like giant scour features. High-resolution multi-beam bathymetry (vertical precision of 0.15 m and horizontal resolution of 1.0 m) and 1-4.5 kHz Chirp seismic reflection profiles were collected in July 2011 over two of these large topographic depressions. The surveys were conducted using an autonomous underwater vehicle (AUV) during two 17.5-hour-long dives in 2,717 to 2,533 m water depths and focused on a 4.8 km long by 4.0 km wide area. An inertial navigation system combined with a Doppler velocity sonar allowed the AUV to fly pre-programmed grids at 3 knots while maintaining an altitude of 50 m above the seafloor. Our high-resolution surveys reveal the fine-scale morphology and shallow seafloor structure of two of these giant scours. The two depressions are up to 100 m deeper than the surrounding seafloor, up to 3.4 km long (N-S axis), up to 1.8 km wide (E-W axis), and markedly asymmetric in the E-W depth profile. Distinctive arcuate scarps which slope at ~ 27° form the eastern (upstream) edge of both depressions. While the seafloor surrounding these scarps is smooth, the scarp face shows horizontal lineations that are interpreted to be outcrops of bedding surfaces. Apparently seafloor erosion focused on the face of this scarp has exposed an ~100 m thick stratigraphic section. The bathymetry also shows numerous E-W oriented ridges ~180 m in length and perpendicular to the overall trace of these scarp, resulting in a serrated or scalloped appearance. The ridges on the scarp faces have an average spacing of 70 m and are separated by intervening gullies. Whether these ridges represent more resistant joints or are a consequence of lateral variations in overriding erosive flows is unclear. The deepest areas within these depressions

  8. Submarine canyon-head morphologies and inferred sediment transport processes in the Almanzora-Alías-Garrucha canyon system (SW Mediterranean)

    NASA Astrophysics Data System (ADS)

    Durán, R.; Puig, P.; Muñoz, A.; Elvira, E.; Guillén, J.

    2015-12-01

    Submarine canyons are morphological incisions into continental margins that act as major conduits of sediment from shallow- to deep-sea regions. Different transport processes and triggering mechanisms involving various time-scales can operate through them. Canyon heads are key areas for understanding the shelf-to-canyon sedimentary dynamics and assessing the predominant hydrodynamic and sedimentary processes shaping their morphology. High-resolution multibeam bathymetries were conducted at the various heads from the Almanzora-Alías-Garrucha canyon system to recognize their specific morphological features. A direct connection from the Almanzora River was evidenced by the coalescence of cyclic steps on the prodelta deposits and their continuation towards various canyon heads. This suggests the occurrence of flood events causing hyperpycnal flows that progress directly into the canyon. A second type of canyon head results from the formation and merging of linear gullies at the southern limit of the prodelta, being interpreted as the morphological expression of the distal off-shelf transport of flood-related hyperycnal flows potentially transformed into wave-supported sediment gravity flows. These two canyon head occur at 80-90 m water depth, incising only the outer shelf. A third canyon head morphological type was found at much shallower water depths (10-20 m), being disconnected from any major river source. They cut into the infralittoral prograding wedge and some tributaries show crescent shaped bedforms (CSB) along their axis. These CSB have been observed until a water depth of 90 m and have been interpreted as the result of storm-induced sediment gravity flows. An instrumented mooring was deployed from October 2014 to April 2015 to monitor the contemporary sediment transport processes through a canyon axis with CSB. The sedimentary dynamics was governed by storms, with several down-canyon transport events, but none of the storms triggered a sediment gravity flow.

  9. 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.

  10. Mass wasting features in Juventae Chasma, Mars

    NASA Astrophysics Data System (ADS)

    Sarkar, Ranjan; Singh, Pragya; Porwal, Alok; Ganesh, Indujaa

    2016-07-01

    Introduction : We report mass-wasting features preserved as debris aprons from Juventae Chasma. Diverse lines of evidence and associated geomorphological features indicate that fluidized ice or water within the wall rocks of the chasma could be responsible for mobilizing the debris. Description : The distinctive features of the landslides in Juvenate Chasma are: (1) lack of a well-defined crown or a clear-cut section at their point of origin and instead the presence of amphitheatre-headed tributary canyons; (2) absence of slump blocks; (3) overlapping of debris aprons; (4) a variety of surface textures from fresh and grooved to degraded and chaotic; (5) rounded lobes of debris aprons; (6) large variation of sizes from small lumps (~0.52 m2) to large tongue shaped ones (~ 80 m2); (7) smaller average size of landslides as compared to other chasmas; and (8) occasional preservation of fresh surficial features indicating recent emplacement. Discussion : Amphitheatre-headed tributary canyons, which are formed due to ground water sapping, indicate that the same was responsible for wall-section collapse, although a structural control cannot be completely ruled out. The emplacement of the mass wasting features preferentially at the mouths of amphitheatre-headed tributary canyons along with the rounded flow fronts of the debris suggest fluids may have played a vital role in their emplacement. The mass-wasting features in Juventae Chasma are unique compared to other landslides in Valles Marineris despite commonalities such as the radial furrows, fan-shaped outlines, overlapping aprons and overtopped obstacles. The unique set of features and close association with amphitheatre-headed tributary canyons imply that the trigger of the landslides was not structural or tectonic but possibly weakness imparted by the presence of water or ice in the pore-spaces of the wall. Craters with fluidized ejecta blankets and scalloped depressions in the surrounding plateau also support this

  11. Holocene canyon activity under a combination of tidal and tectonic forcing

    NASA Astrophysics Data System (ADS)

    Mountjoy, Joshu; Micallef, Aaron; Stevens, Craig; Stirling, Mark

    2013-04-01

    The majority of submarine canyon systems that are active during sea level highstands are coupled to terrestrial or littoral sediment transport systems (e.g. high sediment-yield rivers, wave-base sediment disturbance). However, non-coupled canyon systems can also exhibit sedimentary activity. Characterising the nature, origin, and spatial and temporal influence of the processes responsible for this sedimentary activity is important to understand the extent of sediment and carbon transfer to the deep sea, the impact of sedimentary flows on biological colonisation and diversity, and the control of recent seafloor processes on canyon morphology. The Cook Strait canyon system, between the North and South islands of New Zealand, is a large (1800 km2), multi-branching, shelf-indenting canyon on an active subduction margin. The canyon comes within 1 km of the coast, but does not intercept fluvial or littoral sediment systems and is therefore defined as a non-terrestrially-coupled system. Sediment transport on the continental shelf, associated with a strong tidal stream, and seafloor disturbance related to numerous high-activity faults is known from previous studies. Little is known, however, about the rates of sedimentary activity in the canyon and the processes driving it. The canyon system therefore provides an excellent study area for understanding sediment transport in a non-coupled submarine canyon system. Analysis of EM300 multibeam bathymetry, gravity cores, 3.5 kHz seismic reflection profiles, camera and video transects and current meter data reveals a system where oceanographic (tidal) and tectonic (earthquake) processes are moving sediment from the continental shelf, through the upper canyon, and finally to the deep ocean. Sediment accumulation rates may reach several mm/yr in the upper canyons, with data suggesting minimum rates of 0.5 mm/yr. We demonstrate that tidal currents are sufficient to mobilise fine to medium sand around and within the upper canyon

  12. Geothermal data for 95 thermal and nonthermal waters of the Valles Caldera - southern Jemez Mountains region, New Mexico

    SciTech Connect

    Goff, F.; McCormick, Trujillo, P.E. Jr.; Counce, D.; Grigsby, C.O.

    1982-05-01

    Field, chemical, and isotopic data for 95 thermal and nonthermal waters of the southern Jemez Mountains, New Mexico are presented. This region includes all thermal and mineral waters associated with Valles Caldera and many of those located near the Nacimiento Uplift, near San Ysidro. Waters of the region can be categorized into five general types: (1) surface and near surface meteoric waters; (2) acid-sulfate waters (Valles Caldera); (3) thermal meteoric waters (Valles Caldera); (4) deep geothermal and derivative waters (Valles Caldera); and (5) mineralized waters near San Ysidro. Some waters display chemical and isotopic characteristics intermediate between the types listed. The object of the data is to help interpret geothermal potential of the Jemez Mountains region and to provide background data for investigating problems in hydrology, structural geology, hydrothermal alterations, and hydrothermal solution chemistry.

  13. Hydrogeochemical data for thermal and nonthermal waters and gases of the Valles Caldera- southern Jemez Mountains region, New Mexico

    SciTech Connect

    Shevenell, L.; Goff, F.; Vuataz, F.; Trujillo, P.E. Jr.; Counce, D.; Janik, C.J.; Evans, W.

    1987-03-01

    This report presents field, chemical, gas, and isotopic data for thermal and nonthermal waters of the southern Jemez Mountains, New Mexico. This region includes all thermal and mineral waters associated with Valles Caldera and many of those located near the Nacimiento Uplift, north of San Ysidro. Waters of the region can be categorized into five general types: (1) surface and near-surface meteoric waters; (2) acid-sulfate waters at Sulphur Springs (Valles Caldera); (3) thermal meteoric waters in the ring fracture zone (Valles Caldera); (4) deep geothermal waters of the Baca geothermal field and derivative waters in the Soda Dam and Jemez Springs area (Valles Caldera); and (5) mineralized waters near San Ysidro. Some waters display chemical and isotopic characteristics intermediate between the types listed. Data in this report will help in interpreting the geothermal potential of the Jemez Mountains region and will provide background for investigating problems in hydrology, structural geology, hydrothermal alterations, and hydrothermal solution chemistry.

  14. 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.

  15. 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.

  16. 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.

  17. Canyon formation constraints on the discharge of catastrophic outburst floods of Earth and Mars

    NASA Astrophysics Data System (ADS)

    Lapotre, Mathieu G. A.; Lamb, Michael P.; Williams, Rebecca M. E.

    2016-07-01

    Catastrophic outburst floods carved amphitheater-headed canyons on Earth and Mars, and the steep headwalls of these canyons suggest that some formed by upstream headwall propagation through waterfall erosion processes. Because topography evolves in concert with water flow during canyon erosion, we suggest that bedrock canyon morphology preserves hydraulic information about canyon-forming floods. In particular, we propose that for a canyon to form with a roughly uniform width by upstream headwall retreat, erosion must occur around the canyon head, but not along the sidewalls, such that canyon width is related to flood discharge. We develop a new theory for bedrock canyon formation by megafloods based on flow convergence of large outburst floods toward a horseshoe-shaped waterfall. The model is developed for waterfall erosion by rock toppling, a candidate erosion mechanism in well fractured rock, like columnar basalt. We apply the model to 14 terrestrial (Channeled Scablands, Washington; Snake River Plain, Idaho; and Ásbyrgi canyon, Iceland) and nine Martian (near Ares Vallis and Echus Chasma) bedrock canyons and show that predicted flood discharges are nearly 3 orders of magnitude less than previously estimated, and predicted flood durations are longer than previously estimated, from less than a day to a few months. Results also show a positive correlation between flood discharge per unit width and canyon width, which supports our hypothesis that canyon width is set in part by flood discharge. Despite lower discharges than previously estimated, the flood volumes remain large enough for individual outburst floods to have perturbed the global hydrology of Mars.

  18. 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.

  19. Modeling Floods in Athabasca Valles, Mars, Using CTX Stereo Topography

    NASA Astrophysics Data System (ADS)

    Dundas, C. M.; Keszthelyi, L. P.; Denlinger, R. P.; Thomas, O. H.; Galuszka, D.; Hare, T. M.; Kirk, R. L.; Howington-Kraus, E.; Rosiek, M.

    2012-12-01

    Among the most remarkable landforms on Mars are the outflow channels, which suggest the occurrence of catastrophic water floods in the past. Athabasca Valles has long been thought to be the youngest of these channels [1-2], although it has recently become clear that the young crater age applies to a coating lava flow [3]. Simulations with a 2.5-dimensional flood model have provided insight into the details of flood dynamics but have also demonstrated that the Digital Elevation Model (DEM) from the Mars Orbiter Laser Altimeter (MOLA) Mission Experiment Gridded Data Records includes significant artifacts at this latitude at the scales relevant for flood modeling [4]. In order to obtain improved topography, we processed stereo images from the Context Camera (CTX) of the Mars Reconnaissance Orbiter (MRO) using methods developed for producing topographic models of the Moon with images from the Lunar Reconnaissance Orbiter Camera, a derivative of the CTX camera. Some work on flood modeling with CTX stereo has been published by [5], but we will present several advances, including corrections to the published CTX optical distortion model and improved methods to combine the stereo and MOLA data. The limitations of current methods are the accuracy of control to MOLA and the level of error introduced when the MRO spacecraft is not in a high-stability mode during stereo imaging, leading to jitter impacting the derived topography. Construction of a mosaic of multiple stereo pairs, controlled to MOLA, allows us to consider flow through the cluster of streamlined islands in the upper part of the channel [6], including what is suggested to be the best example of flood-formed subaqueous dunes on Mars [7]. We will present results from running a flood model [4, 8] through the high-resolution (100 m/post) DEM covering the streamlined islands and subaqueous dunes, using results from a lower-resolution model as a guide to the inflow. By considering a range of flow levels below estimated

  20. Hydrodynamical Approach to Vehicular Flow in the Urban Street Canyon

    NASA Astrophysics Data System (ADS)

    Duras, Maciej M.

    2001-06-01

    The vehicular flow in the urban street canyon is considered. The classical field description is used in the modelling of the vehicular movement and of gaseous mixture in generic urban street canyon. The dynamical variables include vehicular densities, velocities, and emissivities: of pollutants, heat and exhaust gases, as well as standard mixture components' variables: densities, velocities, temperature, pressures. The local balances' equations predict the dynamics of the complex system. The automatic control of the vehicular flow is attained by the sets of coordinated traffic lights. The automatic control is aimed at minimization of traffic ecological costs by the application of variational calculus (Lagrange's and Bolz's problems). The theoretical description is accompanied by numerical examples of computer fluid dynamics based on real traffic data.

  1. 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.

  2. Canyon Creek: A late Pleistocene vertebrate locality in interior Alaska

    NASA Astrophysics Data System (ADS)

    Weber, Florence R.; Hamilton, Thomas D.; Hopkins, David M.; Repenning, Charles A.; Haas, Herbert

    1981-09-01

    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.

  3. 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.

  4. 27 CFR 9.217 - Happy Canyon of Santa Barbara.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the “Y” in an unimproved road 0.1 mile south of the 800-foot elevation line, west of Happy Canyon Road... Olivos map, and continuing to the marked 1,324-foot elevation point, 0.5 mile southwest of Bar G O Ranch... Figueroa Mountain Road, T8N, R30W; then (12) Proceed east-northeast in a straight line, returning to...

  5. 27 CFR 9.217 - Happy Canyon of Santa Barbara.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... the “Y” in an unimproved road 0.1 mile south of the 800-foot elevation line, west of Happy Canyon Road... Olivos map, and continuing to the marked 1,324-foot elevation point, 0.5 mile southwest of Bar G O Ranch... Figueroa Mountain Road, T8N, R30W; then (12) Proceed east-northeast in a straight line, returning to...

  6. 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.

  7. A simple model for calculating air pollution within street canyons

    NASA Astrophysics Data System (ADS)

    Venegas, Laura E.; Mazzeo, Nicolás A.; Dezzutti, Mariana C.

    2014-04-01

    This paper introduces the Semi-Empirical Urban Street (SEUS) model. SEUS is a simple mathematical model based on the scaling of air pollution concentration inside street canyons employing the emission rate, the width of the canyon, the dispersive velocity scale and the background concentration. Dispersive velocity scale depends on turbulent motions related to wind and traffic. The parameterisations of these turbulent motions include two dimensionless empirical parameters. Functional forms of these parameters have been obtained from full scale data measured in street canyons at four European cities. The sensitivity of SEUS model is studied analytically. Results show that relative errors in the evaluation of the two dimensionless empirical parameters have less influence on model uncertainties than uncertainties in other input variables. The model estimates NO2 concentrations using a simple photochemistry scheme. SEUS is applied to estimate NOx and NO2 hourly concentrations in an irregular and busy street canyon in the city of Buenos Aires. The statistical evaluation of results shows that there is a good agreement between estimated and observed hourly concentrations (e.g. fractional bias are -10.3% for NOx and +7.8% for NO2). The agreement between the estimated and observed values has also been analysed in terms of its dependence on wind speed and direction. The model shows a better performance for wind speeds >2 m s-1 than for lower wind speeds and for leeward situations than for others. No significant discrepancies have been found between the results of the proposed model and that of a widely used operational dispersion model (OSPM), both using the same input information.

  8. 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.

  9. Modelling air quality in street canyons: a review

    NASA Astrophysics Data System (ADS)

    Vardoulakis, Sotiris; Fisher, Bernard E. A.; Pericleous, Koulis; Gonzalez-Flesca, Norbert

    High pollution levels have been often observed in urban street canyons due to the increased traffic emissions and reduced natural ventilation. Microscale dispersion models with different levels of complexity may be used to assess urban air quality and support decision-making for pollution control strategies and traffic planning. Mathematical models calculate pollutant concentrations by solving either analytically a simplified set of parametric equations or numerically a set of differential equations that describe in detail wind flow and pollutant dispersion. Street canyon models, which might also include simplified photochemistry and particle deposition-resuspension algorithms, are often nested within larger-scale urban dispersion codes. Reduced-scale physical models in wind tunnels may also be used for investigating atmospheric processes within urban canyons and validating mathematical models. A range of monitoring techniques is used to measure pollutant concentrations in urban streets. Point measurement methods (continuous monitoring, passive and active pre-concentration sampling, grab sampling) are available for gaseous pollutants. A number of sampling techniques (mainly based on filtration and impaction) can be used to obtain mass concentration, size distribution and chemical composition of particles. A combination of different sampling/monitoring techniques is often adopted in experimental studies. Relatively simple mathematical models have usually been used in association with field measurements to obtain and interpret time series of pollutant concentrations at a limited number of receptor locations in street canyons. On the other hand, advanced numerical codes have often been applied in combination with wind tunnel and/or field data to simulate small-scale dispersion within the urban canopy.

  10. 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.

  11. 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

  12. 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

  13. Box Canyon Model Watershed Project : Annual Report 1997/1998.

    SciTech Connect

    Kalispel Natural Resource Department

    1998-01-01

    In 1997, the Kalispel Natural Resource Department (KNRD) initiated the Box Canyon Watershed Project. This project will concentrate on watershed protection and enhancement from an upland perspective and will complement current instream restoration efforts implemented through the Kalispel Resident Fish Project. Primary focus of this project is the Cee Cee Ah Creek watershed due to its proximity to the Reservation, importance as a traditional fishery, and potential for bull trout and west-slope cutthroat trout recovery.

  14. Bedded barite in East Northumberland Canyon, Nye County, Nevada

    USGS Publications Warehouse

    Shawe, Daniel R.; Poole, F.G.; Brobst, Donald Albert

    1967-01-01

    Bedded barite has been identified in the course of stratigraphic studies by the U.S. Geological Survey in and near East Northumberland Canyon, Toquima Range, Nye County, Nev. The barite beds are interlayered in black chert of probable Ordovician age. The barite rock is mostly dark gray and massive, has a specific gravity averaging about 4.0, and contains, by chemical analysis, 70.7 to 93.9 percent BaSO4.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Hydraulics of outburst floods spilling over a steep-walled canyon: Implications for paleo-discharges on Mars

    NASA Astrophysics Data System (ADS)

    Lapotre, Mathieu; Lamb, Michael

    2013-04-01

    Canyons carved by outburst floods are common landforms on Earth and Mars. These canyons are generally found in fractured basalts and jointed sedimentary rocks. Flood-carved canyons commonly have steep headwalls and a roughly constant width, and are often thought to have formed from upstream headwall propagation due to waterfall erosion. Because morphology is readily available from satellite imagery, these canyons offer a unique opportunity to quantify the discharge of rare, catastrophic paleo-floods on Earth and Mars. However, mechanistic relationships that relate canyon size to flood discharge have yet to be developed. We propose that the width of a canyon headwall in fractured rock is set by the spatial distribution of erosion around the rim of the canyon, which is controlled by the distribution of shear stresses induced by the overflowing water as it is focused into the canyon head. We test this hypothesis by performing a series of numerical simulations of flood-water focusing using ANUGA Hydro, a 2D-depth averaged, fully turbulent, hydraulic numerical modeling suite allowing for Froude-number transitions. The numerical simulations were designed to explore five dimensionless variables: the aspect ratio of the canyon (length normalized by width), the canyon width to flood-water width ratio, the canyon width to normal-flow depth ratio, the Froude number, and the topographic gradient upstream of the canyon. Preliminary results show that flow focusing leads to increased shear stresses at the canyon head compared to the sides of the canyon for subcritical floods and higher canyon aspect ratios. This suggests that proto-canyons start growing from a topographic defect in all directions until they reach a critical length for the side walls to dry. Once this critical length is attained, canyons focus most of the flood waters into their heads, and propagate upstream only, maintaining roughly constant widths. Preliminary results suggest that canyon width may be used to

  2. 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].

  3. Geology of Raymond Canyon, Sublette Range, western Wyoming

    SciTech Connect

    Shoemaker, W.A.

    1984-07-01

    Raymond Canyon is located on the west side of the Sublette Range, Lincoln County, Wyoming. The study area is just east of the Idaho border and 10 mi (16 km) southeast of Geneva, Idaho. Formations exposed range in age from Late Pennsylvanian to Tertiary (Pliocene) and include: the lower part of the Wells Formation (Pennsylvanian, total thickness 720 ft or 219 m); the upper part of the Wells Formation and the Phosphoria Formation (both Permian, 153-210 ft or 47-64 m); the Dinwoody Formation (185 ft or 56 m); Woodside Shale (540 ft or 165 m); Thaynes Limestone (2345 ft or 715 m); and Ankareh Formation (930 ft or 283 m), all of Triassic age; the Nugget Sandstone (1610 ft or 491 m), Twin Creek Limestone, Preuss Sandstone, and Stump Formation, all of Jurassic age; and the Salt Lake formation and the Sublette conglomerate, both Pliocene postorogenic continental deposits. Generally these formations are thinner than in nearby areas to the west and northwest. Raymond Canyon lies on the upper plate of the Tunp thrust and the lower plate of the Crawford thrust of the Idaho-Wyoming thrust belt. Thus, it lies near the middle of the imbricate stack of shallowly dipping thrust faults that formed in the late Mesozoic. Study of the stratigraphy, structure, petrography, and inferred depositional environments exposed in Raymond Canyon may be helpful to those engaged in energy development in the Idaho-Wyoming thrust belt.

  4. 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.

  5. Episodic incision of the Colorado River in Glen Canyon, Utah

    USGS Publications Warehouse

    Garvin, C.D.; Hanks, T.C.; Finkel, R.C.; Heimsath, A.M.

    2005-01-01

    Incision rates of the Colorado River are integral to understanding the development of the Colorado Plateau. Here we calculate episodic incision rates of the Colorado River based on absolute ages of two levels of Quaternary deposits adjacent to Glen Canyon, Utah, along the north flank of Navajo Mountain. Minimum surface ages are determined by a combination of cosmogenic radionuclide surface exposure ages, uranium series and soil-development formation times. Bedrock incision rates of the Colorado River between c. 500 ka and c. 250 ka, and c. 250 ka to present are c. 0??4 m ka-1 and c. 0??7 m ka-1, respectively. These rates are more than double the rates reported in the Grand Canyon, suggesting that the Colorado River above Lees Ferry is out of equilibrium with the lower section of the river. We also determine incision rates of two tributaries to the Colorado River. Oak Creek and Bridge Creek flow off Navajo Mountain into Glen Canyon from the southeast. Oak Creek and Bridge Creek both have incision rates of c. 0??6 m ka-1 over the past c. 100 ka at points about 9 km away from the main stem of the Colorado River. Copyright ?? 2005 John Wiley & Sons, Ltd.

  6. Aquatic macroinvertebrates and water quality in Sandia Canyon

    SciTech Connect

    Bennett, K.

    1994-05-01

    In 1990, field studies of water quality and stream macroinvertebrate communities were initiated in Sandia Canyon at Los Alamos National Laboratory. The studies were designed to establish baseline data and to determine the effects of routine discharges of industrial and sanitary waste. Water quality measurements were taken and aquatic macroinvertebrates sampled at three permanent stations within the canyon. Two of the three sample stations are located where the stream regularly receives industrial and sanitary waste effluents. These stations exhibited a low diversity of macroinvertebrates and slightly degraded water quality. The last sample station, located approximately 0.4 km (0.25 mi) downstream from the nearest wastewater outfall, appears to be in a zone of recovery where water quality parameters more closely resemble those found in natural streams in the Los Alamos area. A large increase in macroinvertebrate diversity was also observed at the third station. These results indicate that effluents discharged into Sandia Canyon have a marked effect on water quality and aquatic macroinvertebrate communities.

  7. Do urban canyons influence street level grass pollen concentrations?

    NASA Astrophysics Data System (ADS)

    Peel, Robert George; Kennedy, Roy; Smith, Matt; Hertel, Ole

    2014-08-01

    In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found to be statistically significant only in London. The ratio of street/roof level concentrations was compared with temperature, relative humidity, wind speed and direction, and solar radiation. Results indicated that the concentration ratio responds to wind direction with respect to relative canyon orientation and local source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were not found to be significant in either location. These results suggest a tendency for monitoring station data to overestimate exposure in the canyon environment.

  8. Litter in submarine canyons off the west coast of Portugal

    NASA Astrophysics Data System (ADS)

    Mordecai, Gideon; Tyler, Paul A.; Masson, Douglas G.; Huvenne, Veerle A. I.

    2011-12-01

    Marine litter is of global concern and is present in all the world's oceans, including deep benthic habitats where the extent of the problem is still largely unknown. Litter abundance and composition were investigated using video footage and still images from 16 Remotely Operated Vehicle (ROV) dives in Lisbon, Setúbal, Cascais and Nazaré Canyons located west of Portugal. Litter was most abundant at sites closest to the coastline and population centres, suggesting the majority of the litter was land sourced. Plastic was the dominant type of debris, followed by fishing gear. Standardised mean abundance was 1100 litter items km -2, but was as high as 6600 litter items km -2 in canyons close to Lisbon. Although all anthropogenic material may be harmful to biota, debris was also used as a habitat by some macro-invertebrates. Litter composition and abundance observed in the canyons of the Portuguese margin were comparable to those seen in other deep sea areas around the world. Accumulation of litter in the deep sea is a consequence of human activities both on land and at sea. This needs to be taken into account in future policy decisions regarding marine pollution.

  9. 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

  10. Do urban canyons influence street level grass pollen concentrations?

    PubMed

    Peel, Robert George; Kennedy, Roy; Smith, Matt; Hertel, Ole

    2014-08-01

    In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found to be statistically significant only in London. The ratio of street/roof level concentrations was compared with temperature, relative humidity, wind speed and direction, and solar radiation. Results indicated that the concentration ratio responds to wind direction with respect to relative canyon orientation and local source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were not found to be significant in either location. These results suggest a tendency for monitoring station data to overestimate exposure in the canyon environment. PMID:24037300

  11. 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

  12. 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.

  13. Large eddy simulation of turbulent flow and of pollutant transport in a street canyon

    NASA Astrophysics Data System (ADS)

    Starchenko, Alexander V.; Danilkin, Evgeniy A.

    2015-11-01

    The work presents a non-steady three-dimensional eddy resolving model intended for the simulation of non-isothermal turbulent separation flows in street canyons. For a subgrid-scale turbulence parameterization, the Smagorinsky gradient model is used. The calculation results demonstrate the effects of pollutant source location, street canyon size, basic stream rate and wall temperature difference on air pollution in the canyon.

  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. Valles caldera region, New Mexico, and the emerging continental scientific drilling program

    SciTech Connect

    Goff, F.; Gardner, J.N.

    1988-06-10

    Valles caldera is best known in recent years as an excellent example of a resurgent caldera and as the site of a high-temperature geothermal system. However, Valles caldera and the surrounding Jemez Mountains volcanic field possess a rich history of geologic research that dates back to the late 1880s. Through the years, the research focus has changed as different economic and scientific factors have exerted their influence. Early work emphasized mining activity, while modern work has stressed volcanology and, later, geothermal development. Only in the last 5 years has it been possible to view the region as a dynamic, integrated magma-hydrothermal system having a complex evolution lasting more than 13 m.y.

  16. Clustered streamlined forms in Athabasca Valles, Mars: Evidence for sediment deposition during floodwater ponding

    USGS Publications Warehouse

    Burr, D.

    2005-01-01

    A unique clustering of layered streamlined forms in Athabasca Valles is hypothesized to reflect a significant hydraulic event. The forms, interpreted as sedimentary, are attributed to extensive sediment deposition during ponding and then streamlining of this sediment behind flow obstacles during ponded water outflow. These streamlined forms are analogous to those found in depositional basins and other loci of ponding in terrestrial catastrophic flood landscapes. These terrestrial streamlined forms can provide the best opportunity for reconstructing the history of the terrestrial flooding. Likewise, the streamlined forms in Athabasca Valles may provide the best opportunity to reconstruct the recent geologic history of this young Martian outflow channel. ?? 2005 Elsevier B.V. All rights reserved.

  17. Mangala Valles, Mars: Investigations of the Source of Flood Water and Early Stages of Flooding

    NASA Technical Reports Server (NTRS)

    Ghatan, Gil J.; Head, James W.; Wilson, L.; Leask, H. J.

    2004-01-01

    Mangala Valles, an approx. 900 km long north-south trending outflow channel located southwest of the Tharsis rise, extends northward from one of the Memnonia Fossae graben across the southern highlands, terminating at the dichotomy boundary. Previous Viking-based analyses suggest that the water that carved the channel was expelled from the graben, possibly during two distinct flood events, one in the Late Hesperian and one in the Latest Hesperian/Early Amazonian. The mechanism by which the water was transported to the graben, and ultimately to the surface remained ambiguous, although two general scenarios were proposed: melting of near surface ground ice via nearby Tharsis lava flows, and tapping of a near surface aquifer via faulting associated with the graben. Here we use MOLA altimetric data and MOC and THEMIS images to reexamine Mangala Valles and the surrounding region. Further, we develop a new model for the production and transport of the floodwater.

  18. Variability of CO2 concentrations and fluxes in and above an urban street canyon

    NASA Astrophysics Data System (ADS)

    Lietzke, Björn; Vogt, Roland

    2013-08-01

    The variability of CO2 concentrations and fluxes in dense urban environments is high due to the inherent heterogeneity of these complex areas and their spatio-temporally variable anthropogenic sources. With a focus on micro- to local-scale CO2-exchange processes, measurements were conducted in a street canyon in the city of Basel, Switzerland in 2010. CO2 fluxes were sampled at the top of the canyon (19 m) and at 39 m while vertical CO2 concentration profiles were measured in the center and at a wall of the canyon. CO2 concentration distributions in the street canyon and exchange processes with the layers above show, apart from expected general diurnal patterns due mixing layer heights, a strong dependence on wind direction relative to the canyon. As a consequence of the resulting corkscrew-like canyon vortex, accumulation of CO2 inside the canyon is modulated with distinct distribution patterns. The evaluation of diurnal traffic data provides good explanations for the vertical and horizontal differences in CO2-distribution inside the canyon. Diurnal flux characteristics at the top of the canyon can almost solely be explained with traffic density expressed by the strong linear dependence. Even the diurnal course of the flux at 39 m shows a remarkable relationship to traffic density for east wind conditions while, for west wind situations, a change toward source areas with lower emissions leads to a reduced flux.

  19. Deep-sea scavenging amphipod assemblages from the submarine canyons of the Western Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Duffy, G. A.; Horton, T.; Billett, D. S. M.

    2012-11-01

    Submarine canyons have often been identified as hotspots of secondary production with the potential to house distinct faunal assemblages and idiosyncratic ecosystems. Within these deep-sea habitats, assemblages of scavenging fauna play a vital role in reintroducing organic matter from large food falls into the wider deep-sea food chain. Free-fall baited traps were set at different depths within three submarine canyons on the Iberian Margin. Amphipods from the traps were identified to species level and counted. Scavenging amphipod assemblages were compared at different depths within each canyon and between individual canyon systems. Using data from literature, abyssal plain assemblages were compared to submarine canyon assemblages. Samples from canyons were found to contain common abyssal plain species but in greater than expected abundances. It is proposed that this is a result of the high organic carbon input into canyon systems owing to their interception of sediment from the continental shelf and input from associated estuarine systems. Community composition differed significantly between the submarine canyons and abyssal plains. The cause of this difference cannot be attributed to one environmental variable due to the numerous inherent differences between canyons and abyssal plains.

  20. 75 FR 71102 - Jones Canyon Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... feasibility of the Jones Canyon Pumped Storage Project (Project) near Grass Valley, Sherman County, Oregon...-foot-long, underground transmission line connecting to an existing substation; and (4)...

  1. 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.

  2. Geologic Map of the Upper Parashant Canyon and Vicinity, Mohave County, Northwestern Arizona

    USGS Publications Warehouse

    Billingsley, George H.; Harr, Michelle L.; Wellmeyer, Jessica L.

    2000-01-01

    Introduction The geologic map of the upper Parashant Canyon area covers part of the Colorado Plateau and several large tributary canyons that make up the western part of Arizona's Grand Canyon. The map is part of a cooperative U.S. Geological Survey and National Park Service project to provide geologic information for areas within the newly established Grand Canyon/Parashant Canyon National Monument. Most of the Grand Canyon and parts of the adjacent plateaus have been geologically mapped; this map fills in one of the remaining areas where uniform quality geologic mapping was needed. The geologic information presented may be useful in future related studies as to land use management, range management, and flood control programs for federal and state agencies, and private concerns. The map area is in a remote region of the Arizona Strip, northwestern Arizona about 88 km south of the nearest settlement of St. George, Utah. Elevations range from about 1,097 m (3,600 ft) in Parashant Canyon (south edge of map area) to 2,145 m (7,037 ft) near the east-central edge of the map area. Primary vehicle access is by dirt road locally known as the Mount Trumbull road; unimproved dirt roads and jeep trails traverse various parts of the map area. Travel on the Mount Trumbull road is possible with 2-wheel-drive vehicles except during wet conditions. Extra fuel, two spare tires and extra food and water are highly recommended when traveling in this remote area. The map area includes about 26 sections of land belonging to the State of Arizona, about 40 sections of private land, and a small strip of the Lake Mead National Recreation Area (southeast edge of the map area). The private land is mainly clustered around the abandoned settlement of Mt. Trumbull, locally known as Bundyville, and a few sections are scattered in the upper Whitmore Canyon area just south of Bundyville. Lower elevations within the canyons support a sparse growth of sagebrush, cactus, grass, creosote bush, and a

  3. Hydrothermal outflow plume of Valles caldera, New Mexico, and a comparison with other outflow plumes

    SciTech Connect

    Goff, F.; Shevenell, L.; Gardner, J.N.; Vuataz, F.; Grigsby, C.O.

    1988-06-10

    Stratigraphic, temperature gradient, hydrogeochemical, and hydrologic data have been integrated with geologic data from previous studies to show the structural configuration of the Valles caldera hydrothermal outflow plume. Hydrologic data suggest that 25--50% of the discharge of the Valles outflow is confined to the Jemez fault zone, which predates caldera formation. Thermal gradient data from bores penetrating the plume show that shallow gradients are highest in the vicinity of the Jemez fault zone (up to 190 /sup 0/C/km). Shallow heat flow above the hydrothermal plume is as high as 500 mW m/sup -2/ near core hole VC-1 (Jemez fault zone) to 200 mW m/sup -2/ at Fenton Hill (Jemez Plateau). Chemical and isotopic data indicate that two source reservoirs within the caldera (Redondo Creek and Sulphur Springs reservoirs) are parents to mixed fluids flowing in the hydrothermal plume. However, isotopic data, borehole data, basic geology, and inverse relations between temperature and chloride content at major hot springs indicate that no single reservoir fluid and no single diluting fluid are involved in mixing. The Valles caldera hydrothermal plume is structurally dominated by lateral flow through a belt of vertical conduits (Jemez fault zone) that strike away from the source reservoir. Stratigraphically confined flow is present but dispersed over a wide area in relatively impermeable rocks. The Valles configuration is contrasted with the configuration of the hydrothermal plume at Roosevelt Hot Springs, which is dominated by lateral flow through a near-surface, widespread, permeable aquifer. Data from 12 other representative geothermal systems show that outflow plumes occur in a variety of magmatic and tectonic settings, have varying reservoir compositions, and have different flow characteristics.

  4. 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

  5. Lithologic descriptions and temperature profiles of five wells in the southwestern Valles caldera region, New Mexico

    SciTech Connect

    Shevenell, L.; Goff, F.; Miles, D.; Waibel, A.; Swanberg, C.

    1988-01-01

    The subsurface stratigraphy and temperature profiles of the southern and western Valles caldera region have been well constrained with the use of data from the VC-1, AET-4, WC 23-4, PC-1 and PC-2 wells. Data from these wells indicate that thermal gradients west of the caldera margin are between 110 and 140)degrees)C/km, with a maximum gradient occurring in the bottom of PC-1 equal to 240)degrees)C/km as a result of thermal fluid flow. Gradients within the caldera reach a maximum of 350)degrees)C/km, while the maximum thermal gradient measured southwest of the caldera in the thermal outflow plume is 140)degrees)C/km. The five wells exhibit high thermal gradients (>60)deghrees)C/km) resulting from high conductive heat flow associated with the Rio Grande rift and volcanism in the Valles caldera, as well as high convective heat flow associated with circulating geothermal fluids. Gamma logs run in four of the five wells appear to be of limited use for stratigraphic correlations in the caldera region. However, stratigraphic and temperature data from the five wells provide information about the structure and thermal regime of the southern and western Valles caldera region. 29 refs., 9 figs. 2 tabs.

  6. Subsurface structure of Valles Caldera; a resurgent cauldron in northern New Mexico. [Abstract only

    SciTech Connect

    Goff, F.

    1983-03-01

    Valles Caldera is a 1.1 My old silicic cauldron lying at the intersection of the Rio Grande rift and northeast-trending Jemez Lineament. Geothermal exploration in the caldera region during the last 10 years provides subsurface data which refine our knowledge of deep caldera structure, but raise some questions concerning current models of resurgent cauldrons. For example, a detailed gravity investigation using 730 stations (Segar, 1974) shows a circular negative gravity anomaly centered over the caldera (as expected) but also indicates a strong northeast-trending grain of fault blocks in pre-caldera rocks, that are generally down-faulted to the southeast toward the Rift. Gravity data do not define a diapir structure beneath the resurgent dome attributable to tumescent magma; instead of a northeast-trending horst underlies the Redondo Peak segment of the dome. Interpretation of stratigraphy from many geothermal wells suggests that the caldera and resurgent dome are floored by untilted fault blocks (Hulen and Nielson, 1982). In addition, drilling to Precambrian basement and depths of 3.2 km has not encountered a large intrusive rhyolite that might logically produce tumescence of the dome. The new data indicate that the subsurface structural configuration of Valles Caldera is controlled by pre-caldera tectonics and that a more complicated mechanism is required to explain the resurgent dome standing high inside the caldera. A refined mechanism of resurgence might be one result of CSDP drilling at Valles Caldera.

  7. Experience the magic of light and color: outreach activity by Universidad del Valle student chapter

    NASA Astrophysics Data System (ADS)

    Valdes, Claudia; Reyes, Camilo; Osorio, Alberto; Solarte, Efrain

    2010-08-01

    During 2007, the Universidad del Valle Student Chapter presented a proposal for developing an educational outreach activity for children from an underprivileged zone to the Optical Society of America Foundation (OSAF) and to SPIE. The activity was carried out jointly by OSA and SPIE Universidad del Valle Student Chapters in the hillsides of Santiago de Cali, in a zone known as "Pueblo Joven" during 2008. It was aimed to boys and girls with ages between 8 and 13 years and was called "Experience the magic of light and color". The main purpose was to bring the children some basic concepts on optics and to encourage them to explore science through optics. The Universidad del Valle Student Chapters designed a series of talks and practical workshops where children participated in hands-on experiments that easily explain the fundamental concepts of light phenomena. Afterwards the children presented their achievements in a small science fair offered to the community and tried to explain in their own words what they learned and built. In this work, we present the most successful experimental designs and the educational standards we tried to develop with this activity.

  8. 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.

  9. Use of Composite Fingerprinting Technique to Determine Contribution of Paria River Sediments to Dam-Release Flood Deposits in Marble Canyon, Grand Canyon, Az

    NASA Astrophysics Data System (ADS)

    Chapman, K.; Parnell, R. A.; Smith, M. E.; Grams, P. E.; Mueller, E. R.

    2015-12-01

    The 1963 closure of Glen Canyon Dam drastically reduced the downstream sediment supply and altered daily flow regimes of the Colorado River through Grand Canyon, resulting in significant sandbar erosion downstream of the dam. Dam-release floods, known as High Flow Experiments (HFEs), have occurred six times since 1996 and are intended to rebuild Grand Canyon sandbars using tributary-supplied sediment. In Marble Canyon (first 100 km of Grand Canyon) the targeted tributary is the Paria River which supplies approximately 90% of the annual suspended sediment flux through Marble Canyon; the same input contributed less than 6% prior to the dam. Annual topographic surveys have established that HFEs are effective at rebuilding sandbars. However, the long-term viability of using HFEs for sandbar maintenance is dependent on a sustainable source of sediments comprising HFE deposits. Significant use of non-tributary, main-stem sediments (i.e. pre-dam sand stored in eddies or the channel bed) in HFE deposits would indicate reliance on a limited resource, and diminishing returns in the ability of HFEs to rebuild sandbars. In this study, we sampled vertically throughout 12 bars in Marble Canyon to document temporal and downstream changes in the proportion of sediment sourced from the Paria River during the 2013 and 2014 HFEs. Preliminary data suggest that heavy mineral compositions and concentrations of Ti, S, Cr and Rb, all of which are influenced by grainsize, could be sufficiently capable of differentiating Paria-derived and main-stem sediments when combined into a composite fingerprint (CF). A multivariate mixing model using these CFs quantitatively determines the contribution of Paria-derived sediment in each HFE deposit sample. Mixing model endmembers for non-Paria sand include pre-dam flood deposits in Glen and Marble Canyons, and Marble Canyon dredge samples. These results elucidate the role of contemporary versus legacy sediment in long-term sandbar maintenance.

  10. 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.

  11. 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.

  12. Unusually high food availability in Kaikoura Canyon linked to distinct deep-sea nematode community

    NASA Astrophysics Data System (ADS)

    Leduc, D.; Rowden, A. A.; Nodder, S. D.; Berkenbusch, K.; Probert, P. K.; Hadfield, M. G.

    2014-06-01

    Kaikoura Canyon, on the eastern New Zealand continental margin, is the most productive, non-chemosynthetic deep-sea habitat described to date, with megafaunal biomass 100-fold higher than those of other deep-sea habitats. The present study, which focused on free-living nematodes, provides the first comparison of faunal community structure and diversity between Kaikoura Canyon and nearby open slope habitats. Results show substantially higher food availability in the canyon relative to open slope sediments, which probably reflects greater levels of primary productivity above the canyon, coupled with downwelling and/or topographically-induced channelling, which serves to concentrate surface-derived organic matter along the canyon axis. This high food availability appears to be responsible for the elevated nematode biomass in Kaikoura Canyon, with values exceeding all published nematode biomass data from canyons elsewhere. There was also markedly lower local species diversity of nematodes inside the canyon relative to the open slope habitat, as well as a distinct community structure. The canyon community was dominated by species, such as Sabateria pulchra, which were absent from the open slope and are typically associated with highly eutrophic and/or disturbed environments. The presence of these taxa, as well as the low observed diversity, is likely to reflect the high food availability, and potentially the high levels of physically and biologically induced disturbance within the canyon. Kaikoura Canyon is a relatively small habitat characterised by different environmental conditions that makes a disproportionate contribution to deep-sea diversity in the region, despite its low species richness.

  13. 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

  14. 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

  15. 77 FR 42505 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Long Canyon Mine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-19

    ... Mine Project by any of the following methods: Email: BLM_NV_ELDOLongCanyonMine@blm.gov . Fax: 775-753... lead, telephone: 775-753-0342; email: BLM_NV_ELDOLongCanyonMine@blm.gov . Persons who use...

  16. Aerodynamic effects of trees on pollutant concentration in street canyons.

    PubMed

    Buccolieri, Riccardo; Gromke, Christof; Di Sabatino, Silvana; Ruck, Bodo

    2009-09-15

    This paper deals with aerodynamic effects of avenue-like tree planting on flow and traffic-originated pollutant dispersion in urban street canyons by means of wind tunnel experiments and numerical simulations. Several parameters affecting pedestrian level concentration are investigated, namely plant morphology, positioning and arrangement. We extend our previous work in this novel aspect of research to new configurations which comprise tree planting of different crown porosity and stand density, planted in two rows within a canyon of street width to building height ratio W/H=2 with perpendicular approaching wind. Sulfur hexafluoride was used as tracer gas to model the traffic emissions. Complementary to wind tunnel experiments, 3D numerical simulations were performed with the Computational Fluid Dynamics (CFD) code FLUENT using a Reynolds Stress turbulence closure for flow and the advection-diffusion method for concentration calculations. In the presence of trees, both measurements and simulations showed considerable larger pollutant concentrations near the leeward wall and slightly lower concentrations near the windward wall in comparison with the tree-less case. Tree stand density and crown porosity were found to be of minor importance in affecting pollutant concentration. On the other hand, the analysis indicated that W/H is a more crucial parameter. The larger the value of W/H the smaller is the effect of trees on pedestrian level concentration regardless of tree morphology and arrangement. A preliminary analysis of approaching flow velocities showed that at low wind speed the effect of trees on concentrations is worst than at higher speed. The investigations carried out in this work allowed us to set up an appropriate CFD modelling methodology for the study of the aerodynamic effects of tree planting in street canyons. The results obtained can be used by city planners for the design of tree planting in the urban environment with regard to air quality issues

  17. 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.

  18. 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...

  19. 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

  20. 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,...

  1. 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,...

  2. 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...

  3. 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...

  4. 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...

  5. 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.

  6. Effects of building-roof cooling on flow and air temperature in urban street canyons

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Jin; Pardyjak, Eric; Kim, Do-Yong; Han, Kyoung-Soo; Kwon, Byung-Hyuk

    2014-05-01

    The effects of building-roof cooling on flow and air temperature in 3D urban street canyons are numerically investigated using a computational fluid dynamics (CFD) model. The aspect ratios of the building and street canyon considered are unity. 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 are minimal differences in flow pattern in the cases in which 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.

  7. 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.

  8. 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.

  9. Large-Eddy Simulation of Pollutant Removal from a Three-Dimensional Street Canyon

    NASA Astrophysics Data System (ADS)

    Michioka, Takenobu; Takimoto, Hiroshi; Sato, Ayumu

    2013-10-01

    Large-eddy simulations were conducted to investigate the mechanism of pollutant removal from a three-dimensional street canyon. Five block configurations with aspect ratios (building height to length) of 1, 2, 4, 8 and infty were used to create an urban-like array. A pollutant was released from a ground-level line source at the centre of the target canyon floor. For smaller aspect ratios, the relative contribution of the turbulent mass flux to net mass flux at the roof level, which was spatially averaged along the roof-level ventilation area, was closer to unity, indicating that turbulent motions mainly affected pollutant removal from the top of the canyon. As aspect ratio increased, the relative contribution became smaller, owing to strong upwind motions. However, the relative contribution again reached near unity for the infinite aspect ratio (i.e. a two-dimensional street canyon) because of lowered lateral flow convergence. At least 75 % of total emissions from the three-dimensional street canyon were attributable to turbulent motions. Pollutant removal by turbulent motions was related to the coherent structures of low-momentum fluid above the canyons. Though the coherent structure size of the low-momentum fluid differed, the positions of low-momentum fluid largely corresponded to instantaneous high concentrations of pollutant above the target canyon, irrespective of canyon geometry.

  10. Effect of Fetch on a Mechanism for Pollutant Removal from a Two-Dimensional Street Canyon

    NASA Astrophysics Data System (ADS)

    Michioka, Takenobu; Takimoto, Hiroshi; Ono, Hiroki; Sato, Ayumu

    2016-07-01

    Large-eddy simulation is conducted to investigate the effect of fetch on the pollutant-removal mechanism from a two-dimensional street canyon with a building-height to street-width (aspect) ratio of 1. The line sources were placed within the first, second, third, fifth, seventh and tenth canyons, and the six tracer gases are simultaneously released by a ground-level continuous pollutant line source placed parallel to the spanwise axis at the canyons. The mean concentration and the deviation of the concentration fluctuation within the canyon roughly reach a near-constant value downwind of the seventh canyon, which is similar to the behaviour of the turbulent intensities. In the first canyon, pollutant removal is affected by both advective flow and turbulent flow; however, the turbulent motions mainly affect pollutant removal from the top of the canyon as the fetch increases. In the first and third canyons, the low-momentum fluid does not always affect pollutant removal, but does so gradually as the fetch increases.

  11. 77 FR 19279 - Long Canyon Pumped Storage Project; Notice of Preliminary Permit Application Accepted for Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ... Energy Regulatory Commission Long Canyon Pumped Storage Project; Notice of Preliminary Permit Application... section 4(f) of the Federal Power Act (FPA), proposing to study the feasibility of the Long Canyon Pumped Storage Project to be located near the town of Moab, Grand County, Utah. The ] project would...

  12. 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.

  13. 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)

  14. 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

  15. 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.

  16. 20140601-0630_Green Machine Florida Canyon Hourly Data

    SciTech Connect

    Thibedeau, Joe

    2014-06-30

    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 01 June to 30 June 2014.

  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. Bathymetry and Canyons of the western Solomon Sea

    NASA Astrophysics Data System (ADS)

    Davies, H. L.; Keene, J. B.; Hashimoto, K.; Joshima, M.; Stuart, J. E.; Tiffin, D. L.

    1986-12-01

    The floor of the western Solomon Sea (for new bathymetric map see inside back cover of this issue) is dominated by the arched and ridged basement of the Solomon Sea Basin, the partly-sediment-filled New Britain Trench, and a more completely filled trench, the Trobriand Trough. There is a deep basin where the trenches join (149° Embayment), and a silled basin west of the New Britain Trench (Finsch Deep). Submarine canyons descend from the west and south to the 149° Embayment. Abyssal fans and plains are structurally defined and locally disturbed by young faults. Probable submerged pinnacle reefs stand in water depths as great as 1,200 m.

  19. An exhumed Late Paleozoic canyon in the rocky mountains

    USGS Publications Warehouse

    Soreghan, G.S.; Sweet, D.E.; Marra, K.R.; Eble, C.F.; Soreghan, M.J.; Elmore, R.D.; Kaplan, S.A.; Blum, M.D.

    2007-01-01

    Landscapes are thought to be youthful, particularly those of active orogenic belts. Unaweep Canyon in the Colorado Rocky Mountains, a large gorge drained by two opposite-flowing creeks, is an exception. Its origin has long been enigmatic, but new data indicate that it is an exhumed late Paleozoic landform. Its survival within a region of profound late Paleozoic orogenesis demands a reassessment of tectonic models for the Ancestral Rocky Mountains, and its form and genesis have significant implications for understanding late Paleozoic equatorial climate. This discovery highlights the utility of paleogeomorphology as a tectonic and climatic indicator. ?? 2007 by The University of Chicago. All rights reserved.

  20. 20130901-0930_Green Machine Florida Canyon Hourly Data

    DOE Data Explorer

    Thibedeau, Joe

    2013-10-25

    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 September 2013 to 30 September 2013.