Predicting coastal cliff erosion using a Bayesian probabilistic model

USGS Publications Warehouse

Hapke, Cheryl J.; Plant, Nathaniel G.

2010-01-01

Regional coastal cliff retreat is difficult to model due to the episodic nature of failures and the along-shore variability of retreat events. There is a growing demand, however, for predictive models that can be used to forecast areas vulnerable to coastal erosion hazards. Increasingly, probabilistic models are being employed that require data sets of high temporal density to define the joint probability density function that relates forcing variables (e.g. wave conditions) and initial conditions (e.g. cliff geometry) to erosion events. In this study we use a multi-parameter Bayesian network to investigate correlations between key variables that control and influence variations in cliff retreat processes. The network uses Bayesian statistical methods to estimate event probabilities using existing observations. Within this framework, we forecast the spatial distribution of cliff retreat along two stretches of cliffed coast in Southern California. The input parameters are the height and slope of the cliff, a descriptor of material strength based on the dominant cliff-forming lithology, and the long-term cliff erosion rate that represents prior behavior. The model is forced using predicted wave impact hours. Results demonstrate that the Bayesian approach is well-suited to the forward modeling of coastal cliff retreat, with the correct outcomes forecast in 70–90% of the modeled transects. The model also performs well in identifying specific locations of high cliff erosion, thus providing a foundation for hazard mapping. This approach can be employed to predict cliff erosion at time-scales ranging from storm events to the impacts of sea-level rise at the century-scale.

Map Showing Seacliff Response to Climatic and Seismic Events, Seabright Beach, Santa Cruz County, California

USGS Publications Warehouse

Hapke, Cheryl J.; Richmond, Bruce M.; D'Iorio, Mimi M.

2002-01-01

Introduction The coastal cliffs along much of the central California coast are actively retreating. Large storms and periodic earthquakes are responsible for most of the documented sea cliff slope failures. Long-term average erosion rates calculated for this section of coast do not provide the spatial or temporal data resolution necessary to identify the processes responsible for retreat of the sea cliffs where episodic retreat threatens homes and community infrastructure. Research suggests that more erosion occurs along the California coast over a short time scale, during periods of severe storms or seismic activity, than occurs during decades of normal weather or seismic quiescence. This is the third map in a series of maps prepared to document the processes of short-term sea cliff retreat through the identification of slope failure styles, spatial variability of failures, and temporal variation in retreat amounts in an area that has been identified as an erosion hotspot. This map presents sea cliff failure and retreat data from the Seabright Beach section, California, which is located on the east side of Santa Cruz along the northern Monterey Bay coast. The data presented in this map series provide high-resolution spatial and temporal information on the location, amount, and processes of sea cliff retreat in Santa Cruz, California. These data show the response of the sea cliffs to both large magnitude earthquakes and severe climatic events such as El Ni?os; this information may prove useful in predicting the future response of the cliffs to events of similar magnitude. The map data can also be incorporated into Global Information System (GIS) for use by researchers and community planners. During this study we developed a method for investigating short-term processes of sea cliff evolution using rectified photographic stereo models. This method allows us to document the linear extent of cliff failures, the spatial and temporal relationship between failures, and the type or style of slope failure. Seabright Beach extends 0.9 km from San Lorenzo Point on the west to the Santa Cruz Yacht Harbor on the east. The cliffs at Seabright Beach are completely protected from wave attack by a wide beach. The protective beach is a relatively recent feature that formed after the emplacement of the Santa Cruz Yacht Harbor jetty in 1963-1964. Prior to the completion of the jetty, the cliffs at Seabright Beach were subject to daily wave attack. The data in this study are post-jetty construction; therefore, the sea cliff failures and cliff retreat are the result of nonmarine processes (rainfall, groundwater and seismic shaking). The 8 to 15 m high cliffs at Seabright Beach are composed of the Miocene to Pliocene Purisima Formation, which is overlain by unconsolidated Pleistocene terrace deposits. The relative thickness of these units varies along the length of the cliff. At the west end of Seabright Beach, including San Lorenzo Point, nearly the entire cliff section is composed of Purisima Formation and is capped by less than 2 m of terrace deposits. In this exposure, the Purisima Formation is a moderately weathered, moderately indurated massive sandstone. The height of the cliffs and the thickness of the Purisima Formation decrease to the east. In the cliffs immediately adjacent to the harbor, the entire exposure is composed of terrace deposits. Toe-slope debris and wind-blown sand form a nearly continuous fan along the cliff base that obscure the lower portion of the cliff. This study documents the impacts of earthquakes and large storms to the sea cliffs in the Seabright Beach section. The first event is the 1989 Loma Prieta earthquake, a M7.1 earthquake that caused widespread damage to the area stretching from Santa Cruz to the San Francisco Bay. The epicenter of the earthquake was located in the Santa Cruz Mountains, approximately 9 km inland from the coast. Extensive block and debris falls, induced by the seismic shaking, occ

Gravity-induced stresses near a vertical cliff

USGS Publications Warehouse

Savage, W.Z.

1993-01-01

The exact solution for gravity-induced stresses beneath a vertical cliff presented here has application to the design of cut slopes in rock, compares favorably with published photoelastic and finite-element results for this problem, and satisfies the condition that shear and normal stresses vanish on the ground surface, except at the bottom corner where stress concentrations exist. The solution predicts that horizontal stresses are tensile away from the bottom of the cliff-effects caused by movement below the cliff in response to the gravity loading of the cliff. Also, it is shown that along the top of the cliff normal stresses reduce to those predicted for laterally constrained flat-lying topography. ?? 1993.

Automated detection of ice cliffs within supraglacial debris cover

NASA Astrophysics Data System (ADS)

Herreid, Sam; Pellicciotti, Francesca

2018-05-01

Ice cliffs within a supraglacial debris cover have been identified as a source for high ablation relative to the surrounding debris-covered area. Due to their small relative size and steep orientation, ice cliffs are difficult to detect using nadir-looking space borne sensors. The method presented here uses surface slopes calculated from digital elevation model (DEM) data to map ice cliff geometry and produce an ice cliff probability map. Surface slope thresholds, which can be sensitive to geographic location and/or data quality, are selected automatically. The method also attempts to include area at the (often narrowing) ends of ice cliffs which could otherwise be neglected due to signal saturation in surface slope data. The method was calibrated in the eastern Alaska Range, Alaska, USA, against a control ice cliff dataset derived from high-resolution visible and thermal data. Using the same input parameter set that performed best in Alaska, the method was tested against ice cliffs manually mapped in the Khumbu Himal, Nepal. Our results suggest the method can accommodate different glaciological settings and different DEM data sources without a data intensive (high-resolution, multi-data source) recalibration.

Sea-cliff erosion at Pacifica, California caused by 1997/98 El Niño storms

USGS Publications Warehouse

Snell, Charles B.; Lajoie, Kenneth R.; Medley, Edward W.

2000-01-01

Twelve homes were constructed in 1949 at the top of a sea cliff along Esplanade Drive in the City of Pacifica, located on the northern coast of San Mateo County, California. The rear yards of those properties were bounded by an approximately 20-meter (70-foot) high cliff that has retreated episodically at an average rate of 0.5 to 0.6 meter (1.5 to 2 feet) per year over the past 146 years. During the heavy storms of the 1997/1998 El Niño winter, a severe episode of cliff retreat undermined seven homes and threatened three others. All ten homes were condemned and demolished by the City of Pacifica. In this study we analyze geologic, tide, wave, rainfall and wind data in an attempt to determine the causes of this most recent erosion event. We identify the following possible contributory causes of the cliff retreat: 1) wave-induced undercutting of the cliff landward of an old revetment, 2) reduction in beach width over time, 3) reduction in cliff-face stability owing to infiltration from heavy rains, 4) erosion of the cliff face by groundwater piping, and 5) wind-induced erosion of loose dune sand at the top of the cliff. While these factors may explain the retreat of the cliff below the twelve homes along Esplanade Drive, the question remains as to why other geologically similar sites in the region were not severely eroded during the 1997/1998 El Niño winter.

Projecting 21st century coastal cliff retreat in Southern California

NASA Astrophysics Data System (ADS)

Limber, P. W.; Barnard, P.; Erikson, L. H.; Vitousek, S.

2016-12-01

In California, sea level is expected to rise over 1 m by 2100, with extreme projections approaching 3 m. Sea level rise (SLR) increases the frequency, severity, and duration of wave impacts on coastal cliffs, potentially accelerating cliff retreat rates. To assess the future risk to cliff-top infrastructure, densely populated Southern California cities like Los Angeles and San Diego require estimates of coastal retreat over long time (multi-decadal) and large spatial (>100 km) scales. We developed a suite of eight coastal cliff retreat models, ranging in complexity from empirical 1-D representations of cliff response to wave impacts to more intricate 2-D process-based models integrated with artificial neural networks. The ensemble produces a comprehensive estimate of time-averaged coastal cliff retreat with uncertainty, is applicable to different geological environments, and is flexible in application depending on processing power, available data, and/or available time (e.g. if processing power and time are limited, the fast 1-D models can be used as a `rapid assessment' tool). Global-to-local nested wave models provided the hindcasts (1980-2010) and forecasts (2010-2100) used to force the models, and waves were applied in combination with eight SLR scenarios ranging from 0.25 m to 2 m. In the more detailed models, tides, non-tidal residuals, and storm surge were included for the hindcast and forecast periods. For model calibration, a new automated cliff edge extraction routine was used to estimate historical cliff retreat rates from LiDAR data. Initial model application to Southern California suggests that 1 m of SLR during the 21st century will cause cliff retreat rates to increase on average by over 50% relative to historical rates. Model results also demonstrate how small-scale, episodic cliff failure events can coalesce through time into spatially uniform, long-term cliff retreat signals.

Sediment contribution from coastal-cliff erosion into the Nile's littoral cell and its significance to cliff-retreat mitigation efforts

NASA Astrophysics Data System (ADS)

Katz, Oded; Mushkin, Amit; Crouvi, Onn; Alter, Samuel; Shemesh, Ran

2017-04-01

In 2013 the government of Israel initiated a national mitigation program aimed to prevent further collapse and retreat of the country's coastal cliffs, which occur along the northern termination of the Niles's littoral cell (NLC) in the eastern Mediterranean. The goals of this large-scale program are to protect infrastructure and property proximal to the cliff and to conduct long-term maintenance and monitoring of this highly dynamic and sensitive land-sea interface that spans 40 km of Israel's coast line. Here, we examine the possible impact of proposed cliff retreat mitigation efforts on long-shore sediment transport (LST) and coastal dynamics in the region. We used airborne LiDAR spanning a 9-year period between 2006 and 2015 to quantify the annual contribution of sediment eroded from a 20-km-long segment of Israel's coastal cliffs into the NLC. Our measurements reveal 282±85*103 m3 of sediment eroded from the cliff and delivered into the NLC during the studied period. Considering our study area comprises 50% of Israel's sea cliffs we infer an average contribution rate of 30,000-60,000 m^3/yr of cliff-derived sediment into the NLC prior to the planned broad-scale implementation of cliff-retreat mitigation measures. Previous studies report an average net LST flux of 80,000 - 90,000 m3 that reaches the northern termination of the NLC at Haifa Bay annually. Thus, our results suggest that Israel's actively eroding coastal cliffs are primary contributors (40-80%) to the LST budget along the northern termination of the NLC. It therefore appears that successful implementation of the coastal-cliff protection program along Israel's coastline will result in a significant sand deficit, which may drive LST in this part of the NLC out of its 'background' state. In the likely case that the energy/currents driving LST do not change, a possible outcome of this sediment deficit could be increased beach erosion along Israel's coast line to make up for the lost volumes of cliff-eroded sediments.

Sediment contribution from coastal-cliff erosion into the Nile's littoral cell and its significance to cliff-retreat mitigation efforts

NASA Astrophysics Data System (ADS)

Katz, O.; Mushkin, A.; Crouvi, O.; Alter, S.; Shemesh, R.

2016-12-01

In 2013 the government of Israel initiated a national mitigation program aimed to prevent further collapse and retreat of the country's coastal cliffs, which occur along the northern termination of the Niles's littoral cell (NLC) in the eastern Mediterranean. The goals of this large-scale program are to protect infrastructure and property proximal to the cliff and to conduct long-term maintenance and monitoring of this highly dynamic and sensitive land-sea interface that spans 40 km of Israel's coast line. Here, we examine the possible impact of proposed cliff retreat mitigation efforts on long-shore sediment transport (LST) and coastal dynamics in the region. We used airborne LiDAR spanning a 9-year period between 2006 and 2015 to quantify the annual contribution of sediment eroded from a 20-km-long segment of Israel's coastal cliffs into the NLC. Our measurements reveal 282±85*103 m3 of sediment eroded from the cliff and delivered into the NLC during the studied period. Considering our study area comprises 50% of Israel's sea cliffs we infer an average contribution rate of 30,000-60,000 m3/yr of cliff-derived sediment into the NLC prior to the planned broad-scale implementation of cliff-retreat mitigation measures. Previous studies report an average net LST flux of 80,000 - 90,000 m3 that reaches the northern termination of the NLC at Haifa Bay annually. Thus, our results suggest that Israel's actively eroding coastal cliffs are primary contributors (40-80%) to the LST budget along the northern termination of the NLC. It therefore appears that successful implementation of the coastal-cliff protection program along Israel's coastline will result in a significant sand deficit, which may drive LST in this part of the NLC out of its `background' state. In the likely case that the energy/currents driving LST do not change, a possible outcome of this sediment deficit could be increased beach erosion along Israel's coast line to make up for the lost volumes of cliff-eroded sediments.

The national assessment of shoreline change: a GIS compilation of vector cliff edges and associated cliff erosion data for the California coast

USGS Publications Warehouse

Hapke, Cheryl; Reid, David; Borrelli, Mark

2007-01-01

The U.S. Geological Survey has generated a comprehensive data clearinghouse of digital vector cliff edges and associated rates of cliff retreat along the open-ocean California coast. These data, which are presented herein, were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project. Cliff erosion is a chronic problem along many coastlines of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information including rates and trends of coastal cliff retreat. There is also a critical need for these data to be consistent from one region to another. One objective of this work is to a develop standard, repeatable methodology for mapping and analyzing cliff edge retreat so that periodic, systematic, and internally consistent updates of cliff edge position and associated rates of erosion can be made at a national scale. This data compilation for open-ocean cliff edges for the California coast is a separate, yet related study to Hapke and others, 2006 documenting shoreline change along sandy shorelines of the California coast, which is itself one in a series that includes the Gulf of Mexico and the Southeast Atlantic coast (Morton and others, 2004; Morton and Miller, 2005). Future reports and data compilations will include coverage of the Northeast U.S., the Great Lakes, Hawaii and Alaska. Cliff edge change is determined by comparing the positions of one historical cliff edge digitized from maps with a modern cliff edge derived from topographic LIDAR (light detection and ranging) surveys. Historical cliff edges for the California coast represent the 1920s-1930s time-period; the most recent cliff edge was delineated using data collected between 1998 and 2002. End-point rate calculations were used to evaluate rates of erosion between the two cliff edges. Please refer to our full report on cliff edge erosion along the California coastline at http://pubs.usgs.gov/of/2007/1133/ for additional information regarding methods and results (Hapke and others, 2007). Data in this report are organized into downloadable layers by region (Northern, Central and Southern California) and are provided as vector datasets with accompanying metadata. Vector cliff edges may represent a compilation of data from one or more sources and the sources used are included in the dataset metadata. This project employs the Environmental Systems Research Institute's (ESRI) ArcGIS as it's Geographic Information System (GIS) mapping tool and contains several data layers (shapefiles) that are used to create a geographic view of the California coast. The vector data form a basemap comprising polygon and line themes that include a U.S. coastline (1:80,000), U.S. cities, and state boundaries.

Map showing coastal cliff retreat rates along the Big Sur coast, Monterey and San Luis Obispo Counties, California

USGS Publications Warehouse

Hapke, Cheryl J.; Green, Krystal R.

2004-01-01

The average coastal cliff retreat rate along the Big Sur coast is 18 ? 6 cm/yr as measured over a 52-year time period. The erosion reference features measured as the cliff edge include the well-defined cliff edges common to marine terraces, slight breaks in the slope defining the upper edge of the active lower slope, and the road grade. Cliff erosion and retreat are focused in isolated erosion hotspots that account for most of the calculated average retreat.

Environmental Inventory: Little South Fork Cumberland River.

DTIC Science & Technology

1981-11-01

coal and clay shale. The contact between the Mississippian strata (Pennington Formation ) and...these formations include the Barren Fork coal bed and the Stearns coal zone. In addition to these there are several unnamed coal beds. Number and...Cindy Cliff, Coal Cliff, Sand Cliff and Balls Cliff are being mined by the Greenwood Land and Mining Company of Somerset and Parkers Lake, Kentucky

Modelling Coastal Cliff Recession Based on the GIM-DDD Method

NASA Astrophysics Data System (ADS)

Gong, Bin; Wang, Shanyong; Sloan, Scott William; Sheng, Daichao; Tang, Chun'an

2018-04-01

The unpredictable and instantaneous collapse behaviour of coastal rocky cliffs may cause damage that extends significantly beyond the area of failure. Gravitational movements that occur during coastal cliff recession involve two major stages: the small deformation stage and the large displacement stage. In this paper, a method of simulating the entire progressive failure process of coastal rocky cliffs is developed based on the gravity increase method (GIM), the rock failure process analysis method and the discontinuous deformation analysis method, and it is referred to as the GIM-DDD method. The small deformation stage, which includes crack initiation, propagation and coalescence processes, and the large displacement stage, which includes block translation and rotation processes during the rocky cliff collapse, are modelled using the GIM-DDD method. In addition, acoustic emissions, stress field variations, crack propagation and failure mode characteristics are further analysed to provide insights that can be used to predict, prevent and minimize potential economic losses and casualties. The calculation and analytical results are consistent with previous studies, which indicate that the developed method provides an effective and reliable approach for performing rocky cliff stability evaluations and coastal cliff recession analyses and has considerable potential for improving the safety and protection of seaside cliff areas.

The visual cliff's forgotten menagerie: rats, goats, babies, and myth-making in the history of psychology.

PubMed

Rodkey, Elissa N

2015-01-01

Eleanor Gibson and Richard Walk's famous visual cliff experiment is one of psychology's classic studies, included in most introductory textbooks. Yet the famous version which centers on babies is actually a simplification, the result of disciplinary myth-making. In fact the visual cliff's first subjects were rats, and a wide range of animals were tested on the cliff, including chicks, turtles, lambs, kid goats, pigs, kittens, dogs, and monkeys. The visual cliff experiment was more accurately a series of experiments, employing varying methods and a changing apparatus, modified to test different species. This paper focuses on the initial, nonhuman subjects of the visual cliff, resituating the study in its original experimental logic, connecting it to the history of comparative psychology, Gibson's interest in comparative psychology, as well as gender-based discrimination. Recovering the visual cliff's forgotten menagerie helps to counter the romanticization of experimentation by focusing on the role of extrascientific factors, chance, complexity, and uncertainty in the experimental process. © 2015 Wiley Periodicals, Inc.

Dynamics of a cliff top dune

NASA Astrophysics Data System (ADS)

Rasmussen, K. R.

2012-12-01

Morphological changes during more than 100 years have been investigated for a cliff-top dune complex at Rubjerg at the Danish North Sea coast. Here the lower 50 m of the cliff front is composed of Pleistocene steeply inclined floes of silt and clay with coarse sand in between which gives it a saw-tooth appearance. On top of this the dunes are found for several kilometres along the coastline. Due to erosion by the North Sea the cliff has retreated about 120 m between approximately 1880 and 1970 as indicated from two national surveys, and recent GPS-surveys indicate that erosion is continuing at a similar rate. Nevertheless the cliff top dune complex has survived, but its morphology has undergone some changed. The old maps indicate that around 1880 the dune complex was composed of several up to about 20 m high dunes streamlined in the East-West direction which is parallel to the prevailing wind direction. When protective planting started during the first half of the 20th Century the cliff top dunes gradually merged together forming a narrow, tall ridge parallel to the shore line with the highest part reaching about 90 m near 1970. In 1993 the highest points along the ridge was almost 95 m high, but then the protective planting was considerably reduced and recent annual GPS-surveys indicate that the dunes respond quickly to this by changing their morphology towards the original appearance. It is remarkable that despite the mass wasting caused by the constant erosion of the cliff front the dunes have remained more or less intact. Theoretical studies of hill flow indicate given the proper geometry of the cliff then suspension of even coarse grains can be a very effective agent for carrying sand from the exposed parts of the cliff front to and beyond the cliff-top. Mostly the sand grains are deposited within some hundred meters downwind of the cliff dune while silt is often carried more than 10 km inland. Field observations indicate that where the dislodged floes and beds of coarse sand are missing the cliff is steep and dunes are absent at the cliff top. On the other hand when floes are present then some parts of the cliff are less steep and where sand is abundant cliff top dunes seem to be abundant, too. In order to investigate how flow conditions at the cliff front responds to its geometry, scale models of the cliff front approximately 1:10, but with different steepness have been tested in a boundary layer wind tunnel. All runs have been made with proper roughness scaling and besides a variation in their longitudinal profiles some variation in their transverse profiles has also been tested. The surface-near flow has been mapped with high resolution 2-D laser-Doppler profiling, and one of the important aims is to demonstrate the interaction between sediment and geological structure on one side and flow and dune state on the other side. A particular aim is to investigate if and how the separation bubble may have a profound control on mobilization and transport of sediment.

Micro-seismic measurements of cliff motion under wave impact and implications for the development of near-horizontal shore platforms

NASA Astrophysics Data System (ADS)

Dickson, Mark E.; Pentney, Rachael

2012-05-01

Few high-resolution measurements of process-form interactions have been taken on rock coasts, but recent studies in California have shown that portable seismometers enable useful proxy measurements of wave-energy delivery to cliffs. Here we describe measurements over 20 days of high frequency ground motion of cliffs formed in sedimentary (flysch) rocks at Okakari Point, north of Auckland, New Zealand. Three sensors were located in a shore-normal array inland from the cliff top and a fourth sensor was bolted to a ledge 2 m above the cliff toe. The nearshore wave field in front of the cliff and shore platform was monitored using a shore-normal array of 5 wave gauges. The instrumentation provided measurements of wave-energy delivery and consequent ground motion, including the first observations of motion at the top and bottom of cliffs. Results showed that horizontal ground motion is dominant at the cliff top, whereas vertical motion is dominant at the cliff toe. Power spectra show that several high frequency peaks occur in data from the cliff toe, whereas a single, broader peak frequency occurs at the cliff top resulting from signal modification as seismic waves pass through tens of metres of cliff rock. A 100 m wide shore platform at the cliff toe fundamentally controls the patterns of observed energy delivery. The shore platform is nearly horizontal, elevated close to high water level, and abruptly plunges into water > 10 m deep at its seaward edge. As expected, the magnitude of ground motion at all sensors is greatest during larger waves. Measurements further show that ground motion, both at the bottom and top of the cliff, is strongest at low tide and weakest at high tide. This observation is opposite to that noted at Santa Cruz, where ground motion was greatest at high tide. At Okakari Point the most significant high frequency ground motions occur at low tide when waves are forced to break (sometimes violently) against the seaward edge of the shore platform. Four distinctive frequency peaks between 1 and 50 Hz increase in magnitude as tidal stage drops, implying that wave breaking against the outside edge of the shore platform represents an important source of vibration. A detailed understanding of the energy source (e.g. short duration shock pressures) and rock resonance is not provided by this study. However, quantifying the spatial and temporal patterns of energy delivery places strong emphasis on the important role of shore platform geometry in filtering wave-energy delivery to the cliff. During the 20-day experiment most wave energy was delivered to the outside edge of the shore platform, not the cliff toe. The geomorphic role of high-frequency shaking from wave impacts remains to be clearly demonstrated, but if wave impacts are capable of eroding rock then the data from this study imply that under present conditions the outside edge of the shore platform may be subject to higher erosion rates than the cliff toe. It is possible that the shore platform is currently being destroyed rather than created, but a longer programme of measurements is required to test this notion.

Development of Waterfall Cliff Face: An Implication from Multitemporal High-definition Topographic Data

NASA Astrophysics Data System (ADS)

Hayakawa, Y. S.; Obanawa, H.

2015-12-01

Bedrock knickpoints (waterfalls) often act as erosional front in bedrock rivers, whose geomorphological processes are various. In waterfalls with vertical cliffs, both fluvial erosion and mass movement are feasible to form the landscape. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatiotemporal distribution have been limited due to poor accessibility to such cliffs. For the clarification of geomorphological processes in such cliffs, multi-temporal mapping of the cliff face at a high resolution can be advantaged by short-range remote sensing approaches. Here we carry out multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS) for accurate topographic mapping of cliffs around a waterfall. The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff and groundwater outflows from its lower portions. The bedrock consists of alternate layers of jointed andesite lava and conglomerates. The latest major rockfall in 1986 caused approximately 8-m recession of the waterfall lip. Three-dimensional changes of the rock surface were detected by multi-temporal measurements by TLS over years, showing the portions of small rockfalls and surface lowering in the bedrock. Erosion was frequently observed in relatively weak the conglomerates layer, whereas small rockfalls were often found in the andesite layers. Wider areas of the waterfall and cliff were also measured by UAS-based SfM-MVS photogrammetry, improving the mapping quality of the cliff morphology. Point clouds are also projected on a vertical plane to generate a digital elevation model (DEM), and cross-sectional profiles extracted from the DEM indicate the presence of a distinct, 5-10-m deep depression in the cliff face. This appears to have been formed by freeze-thaw and/or wet-dry weathering following the recession in 1986. The long-term development of the waterfall cliff face is then discussed comprising various processes of rockfalls, water pressure and weathering.

Main factors determining bioerosion patterns on rocky cliffs in a drowned valley estuary in the Colombian Pacific (Eastern Tropical Pacific)

NASA Astrophysics Data System (ADS)

Cobo-Viveros, Alba Marina; Cantera-Kintz, Jaime Ricardo

2015-10-01

Bioerosion is an important process that destroys coastal rocks in the tropics. However, the rates at which this process occurs, the organisms involved, and the dynamics of rocky cliffs in tropical latitudes have been less studied than in temperate and subtropical latitudes. To contribute to the knowledge of the bioerosion process in rocky cliffs on the Pacific coast of Colombia (Eastern Tropical Pacific) we compared: 1) boring volume, 2) grain size distribution of the rocks, and 3) rock porosity, across three tidal zones of two cliffs with different wave exposure; these factors were related to the bioeroding community found. We observed that cliffs that were not exposed to wave action (IC, internal cliffs) exhibited high percentages of clays in their grain size composition, and a greater porosity (47.62%) and perforation (15.86%) than exposed cliffs (EC, external cliffs). However, IC also exhibited less diversity and abundance of bioeroding species (22 species and 314 individuals, respectively) compared to the values found in EC (41.11%, 14.34%, 32 and 491, respectively). The most abundant bioeroders were Petrolisthes zacae in IC and Pachygrapsus transversus in EC. Our findings show that the tidal zone is the common factor controlling bioerosion on both cliffs; in addition to the abundance of bioeroders on IC and the number of bioeroding species on EC. The integration of geology, sedimentology, and biology allows us to obtain a more comprehensive view of the patterns and trends in the process of bioerosion.

Recent acceleration in coastal cliff retreat rates on the south coast of Great Britain.

PubMed

Hurst, Martin D; Rood, Dylan H; Ellis, Michael A; Anderson, Robert S; Dornbusch, Uwe

2016-11-22

Rising sea levels and increased storminess are expected to accelerate the erosion of soft-cliff coastlines, threatening coastal infrastructure and livelihoods. To develop predictive models of future coastal change we need fundamentally to know how rapidly coasts have been eroding in the past, and to understand the driving mechanisms of coastal change. Direct observations of cliff retreat rarely extend beyond 150 y, during which humans have significantly modified the coastal system. Cliff retreat rates are unknown in prior centuries and millennia. In this study, we derived retreat rates of chalk cliffs on the south coast of Great Britain over millennial time scales by coupling high-precision cosmogenic radionuclide geochronology and rigorous numerical modeling. Measured 10 Be concentrations on rocky coastal platforms were compared with simulations of coastal evolution using a Monte Carlo approach to determine the most likely history of cliff retreat. The 10 Be concentrations are consistent with retreat rates of chalk cliffs that were relatively slow (2-6 cm⋅y -1 ) until a few hundred years ago. Historical observations reveal that retreat rates have subsequently accelerated by an order of magnitude (22-32 cm⋅y -1 ). We suggest that acceleration is the result of thinning of cliff-front beaches, exacerbated by regional storminess and anthropogenic modification of the coast.

Comment on: Lawrence, J.A., Mortimore, R.N., Stone, K.J., Busby, J.P., 2013. Sea saltwater weakening of chalk and the impact on cliff instability. Geomorphology 191, 14-22

NASA Astrophysics Data System (ADS)

Dornbusch, Uwe

2015-02-01

This comment relates to the conclusion of the recently published paper that "This work challenges the established view by identifying the role of salt from seawater in the degradation of porous rocks in coastal environments as a third and potentially the most important mechanism leading to chalk cliff collapse." (Lawrence et al., 2013: 15). The 'established view' relates to "Traditionally, the two main factors leading to cliff collapse have been considered to be (i) waves attacking and eroding the base of the cliff […] and (ii) water weakening as the chalk becomes saturated […]." (Lawrence et al., 2013: 14). The particular aspect of the paper of making surface weakening the primary process has been picked up more widely following publication under the headlines 'Salt causes chalk cliffs to collapse' in Jarlett (2013), 'Salt makes chalk cliffs collapse' in NERC (2013) and in the web resource 'How does salt make chalk cliffs collapse?' from Leeds University (2013).

Regional beach/cliff system dynamics along the california coast

USGS Publications Warehouse

Hapke, C.J.; Reid, Don

2007-01-01

The coast of California is comprised of both sandy shorelines and cliffed coastline, and in many areas these features spatially coincide. In order to better understand the regional trends of change along the California coast, the U.S. Geological Survey is quantifying both sandy shoreline change and coastal cliff retreat for the state. The resulting database was used to examine the dynamics of the beach/cliff system. We found inconsistent evidence of a relationship between rates of cliff retreat and shoreline change on the spatial scale of 100-km cells. However, when the data are correlated within individual regions, a strong relationship exists between the geomorphology of the coast and the behavior of the beach/cliff system. Areas of high-relief coast show negative correlations, indicating that higher rates of cliff retreat correlate with lower rates of shoreline erosion. In contrast, low- to moderate-relief coasts show strong positive correlations.

Detection of morphological changes in cliff face surrounding a waterfall using terrestrial laser scanning and unmanned aerial system

NASA Astrophysics Data System (ADS)

Hayakawa, Yuichi S.; Obanawa, Hiroyuki

2015-04-01

Waterfall or bedrock knickpoint appears as an erosional front in bedrock rivers forming deep v-shaped valley downstream. Following the rapid fluvial erosion of waterfall, rockfalls and gravita-tional collapses often occur in surrounding steep cliffs. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatio-temporal distribution have been limited due to the difficulties in direct access to such cliffs if with classical measurement methods. However, for the clarification of geomorphological processes oc-curring in the cliffs, multi-temporal mapping of the cliff face at a high resolution is necessary. Re-mote sensing approaches are therefore suitable for the topographic measurements and detection of changes in such inaccessible cliffs. To achieve accurate topographic mapping of cliffs around a wa-terfall, here we perform multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS). The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff, as well as groundwater outflows from its lower portions. The bedrock is composed of alternate layers of andesite lava and conglomerates. Minor rockfalls in the cliffs are often ob-served by local people. The latest major rockfall occurred in 1986, causing ca. 8-m upstream propa-gation of the waterfall lip. This provides a good opportunity to examine the changes in the surround-ing cliffs following the waterfall recession. Multi-time point clouds were obtained by TLS measure-ment over years, and the three-dimensional changes of the rock surface were detected, uncovering the locus of small rockfalls and gully developments. Erosion seems particularly frequent in relatively weak the conglomerates layer, whereas small rockfalls seems to have occurred in the andesite layers. Also, shadows in the TLS point clouds are effectively filled by complementary data of UAS-based SfM-MVS photogrammetry, which can improve the mapping quality of the cliff morphology. The point clouds are also projected on a vertical plane to generate a digital elevation model (DEM). Cross-sectional profiles extracted from the DEM show the presence of a distinct, 5-10-m depression at the mid of the cliff (bottom of the upper andesite layer), which appears to have been formed by freeze-thaw and/or wet-dry weathering following the waterfall recession in 1986.

Identifying the behavioural characteristics of clay cliffs using intensive monitoring and geotechnical numerical modelling

NASA Astrophysics Data System (ADS)

Quinn, J. D.; Rosser, N. J.; Murphy, W.; Lawrence, J. A.

2010-08-01

Coastal monitoring is routinely undertaken to provide an archival record of cliff-line movement that can be used in the development and validation of predictive coast retreat and evolution models. However, coastal monitoring is often purely quantitative in nature, and financial necessity requires deployment over extensive coastal sections. As a result, for local site conditions in particular, only limited geomorphological data are available or included during the development of such predictive models. This has resulted in many current models incorporating a simplistic or generalised representation of cliff behaviour, an approach that progressively loses local credibility when deployed over extensive heterogeneous coastlines. This study addresses this situation at a site of extreme coastline retreat, Holderness, UK, through the application of intensive monitoring of six representative cliff sections nested within a general geomorphological appraisal of the wider coastline as a whole. The data from these surveys have been used to validate a finite difference-based geotechnical modelling assessment of clay cliff stability. Once validated, the geotechnical model was used to simulate a range of scenarios that were sufficient to represent the range of topographic, hydrogeological, geological, and littoral conditions exhibited throughout the region. Our assessment identified that the cliff retreat occurs through the combined influence of direct marine erosion of the cliff, with shallow, structurally controlled failures or substantial mass failures. Critically, the predisposition to any one of these failure mechanisms arises principally as a result of initial cliff height. The results of the numerical modelling have been combined into an empirical slope model that derives the rate of landslide-induced retreat that would arise from mass failures under various future scenarios. Results of this study can be used in the selection and development of retreat models at coastlines of similar physiographic setting to that found at Holderness. The results represent a key step in linking material deformation properties to the processes of cliff change and the subsequent range of landforms found on clay cliffs. As such, the results could also be used more generally to illustrate the likely cliff behaviour of other soft rock coastlines.

Quantifying rock mass strength degradation in coastal rock cliffs

NASA Astrophysics Data System (ADS)

Brain, Matthew; Lim, Michael; Rosser, Nick; Petley, David; Norman, Emma; Barlow, John

2010-05-01

Although rock cliffs are generally perceived to evolve through undercutting and cantilever collapse of material, the recent application of high-resolution three-dimensional monitoring techniques has suggested that the volumetric losses recorded from layers above the intertidal zone produce an equally significant contribution to cliff behaviour. It is therefore important to understand the controls on rockfalls in such layers. Here we investigate the progressive influence of subaerial exposure and weathering on the geotechnical properties of the rocks encountered within the geologically complex coastal cliffs of the northeast coast of England, UK. Through a program of continuous in situ monitoring of local environmental and tidal conditions and laboratory rock strength testing, we aim to better quantify the relationships between environmental processes and the geotechnical response of the cliff materials. We have cut fresh (not previously exposed) samples from the three main rock types (sandstone, mudstone and shale) found within the cliff to uniform size, shape and volume, thus minimizing variability and removing previous surface weathering effects. In order to characterise the intact strength of the rocks, we have undertaken unconfined compressive strength and triaxial strength tests using high pressure (400 kN maximum axial load; 64 MPa maximum cell pressure) triaxial testing apparatus. The results outline the peak strength characteristics of the unweathered materials. We then divided the samples of each lithology into different experimental groups. The first set of samples remained in the laboratory at constant temperature and humidity; this group provides our control. Samples from each of the three rock types were located at heights on the cliff face corresponding with the different lithologies: at the base (mudstone), in the mid cliff (shale) and at the top of the cliff (sandstone). This subjected them to the same conditions experienced by the in situ cliff forming materials, which were also monitored using an array of environmental sensors. This experiment forms the basis of a long term investigation into the effects of varying environmental conditions on rock mass strength degradation over time. Ultimately, we aim to develop rock mass strength degradation curves to build a quantitative understanding of the interaction between coastal rock cliff behaviour and environmental processes.

A quantitative analysis of rock cliff erosion environments

NASA Astrophysics Data System (ADS)

Lim, M.; Rosser, N.; Petley, D. N.; Norman, E. C.; Barlow, J.

2009-12-01

The spatial patterns and temporal sequencing of failures from coastal rock cliffs are complex and typically generate weak correlations with environmental variables such as tidal inundation, wave energy, wind and rain. Consequently, understanding of rock cliff behaviour, its response to predicted changes in environmental forcing and, more specifically, the interaction between marine and climatic factors in influencing failure processes has remained limited. This work presents the results from the first attempt to characterise and quantify the conditions on coastal cliffs that lead to accelerated rates of material detachment. The rate of change in an 80 m high section of coastal rock cliffs has been surveyed annually with high-resolution terrestrial laser scanning (TLS). The rockfall data have been analysed according to a simplified source geology that exhibit distinct magnitude-frequency distributions relating to the dominance of particular failure types. An integrated network of sensors and instrumentation designed to reflect the lithological control on failure has been installed to examine both the distinction between prevailing conditions and those affecting the local cliff environment and the physical response of different rock types to micro-climatic processes. The monitoring system records near-surface rock strain, temperature, moisture and micro-seismic displacement in addition to air temperature, humidity, radiation, precipitation, water-level and three-dimensional wind characteristics. A characteristic environmental signal, unique to the cliff face material, has been identified that differs substantially from that experienced by the surrounding area; suggesting that established methods of meteorological and tidal data collection are insufficient and inappropriate to represent erosive processes. The interaction between thermo- and hydro-dynamics of the cliff environment and the physical response of the rock highlights the composite environmental effects acting on the rock mass and provides a new interpretation on the dominant controls on the behaviour of coastal rock cliffs that challenges the almost universal application of undercutting and cantilever collapse as the primary driver of rock cliff erosion.

Nest-site characteristics and linear abundance of cliff-nesting American kestrels on San Clemente Island, California

USGS Publications Warehouse

Sullivan, Brian L.; Kershner, Eric L.; Finn, S.P.; Condon, Anne M.; Cooper, Douglass M.; Garcelon, David K.

2003-01-01

American Kestrels( Falco sparverius) are typically secondary-cavity nesters, and use of natural cliff cavities for nest sites is less-commonly reported. On San Clemente Island (SCI), California, however, American Kestrels nest primarily on cliffs in major canyons(93%), to a lesser extent on seacliffs(4%), as well as in man-made structures (3%). We located and mapped 99 American Kestrel territories on SCI, and recorded 11 nest-site characteristics at 40 cliff nests during 2001-02. Nest cliffs were typically fractured igneous rock with mean height of 16.1 m +_ 1.8 SE. Mean slope of nest cliffs was vertical (x=91 degrees). Nest cliffs and cavities were significantly oriented to the southeast, away from the prevailing wind direction(NW). In eight canyons, where we believe that we found all occupied American Kestrel territories, the mean linear abundance was 2.1 pairs/km, greater than most published estimates. Contrary to most previous studies, no American Kestrels nested in tree cavities despite their presence in SCI canyons. The absence of cavity-excavating breeding birds from the island likely restricts kestrels to nesting in naturally-formed cavities and man-made structures.

Sea-cliff erosion as a function of beach changes and extreme wave runup during the 1997-1998 El Nino

USGS Publications Warehouse

Sallenger, A.H.; Krabill, W.; Brock, J.; Swift, R.; Manizade, S.; Stockdon, H.

2002-01-01

Over time scales of hundreds to thousands of years, the net longshore sand transport direction along the central California coast has been driven to the south by North Pacific winter swell. In contrast, during the El Nin??o winter of 1997-1998, comparisons of before and after airborne lidar surveys showed sand was transported from south to north and accumulated on the south sides of resistant headlands bordering pocket beaches. This resulted in significant beach erosion at the south ends of pocket beaches and deposition in the north ends. Coincident with the south-to-north redistribution of sand, shoreline morphology became prominently cuspate with longshore wavelengths of 400-700 m. The width and elevation of beaches were least where maximum shoreline erosion occurred, preferentially exposing cliffs to wave attack. The resulting erosional hotspots typically were located in the embayments of giant cusps in the southern end of the pocket beaches. The observed magnitude of sea cliff retreat, which reached 14 m, varied with the number of hours that extreme wave runup exceeded certain thresholds representing the protective capacity of the beach during the El Nin??o winter. A threshold representing the width of the beach performed better than a threshold representing the elevation of the beach. The magnitude of cliff erosion can be scaled using a simple model based on the cross-shore distance that extreme wave runup exceeded the pre-winter cliff position. Cliff erosion appears to be a balance between terrestrial mass wasting processes, which tend to decrease the cliff slope, and wave attack, which removes debris and erodes the cliff base increasing the cliff slope. ?? 2002 Elsevier Science B.V. All rights reserved.

Rates and trends of coastal change in california and the regional behavior of the beach and cliff system

USGS Publications Warehouse

Hapke, C.J.; Reid, Don; Richmond, B.

2009-01-01

The U.S. Geological Survey (USGS) recently completed an analysis of shoreline change and cliff retreat along the California coast. This is the first regional, systematic measurement of coastal change conducted for the West Coast. Long-term (-120 y) and short-term (-25 y) shoreline change rates were calculated for more than 750 km of coastline, and 70 year cliff-retreat rates were generated for 350 km of coast. Results show that 40% of California's beaches were eroding in the long term. This number increased to 66% in the short term, indicating that many beaches have shifted toward a state of chronic erosion. The statewide average net shoreline change rates for the long and short term were 0.2 m/y and -0.2 m/y, respectively. The long-term accretional signal is likely related to large coastal engineering projects in some parts of the state and to large fluxes of sediment from rivers in other areas. The cliff-retreat assessment yielded a statewide average of -0.3 m/y. It was found that Northern California has the highest overall retreat rates, which are influenced by erosion hot spots associated with large coastal landslides and slumps. The databases established as part of the shoreline change and cliff-retreat analyses were further investigated to examine the dynamics of the beach/cliff system. A correlation analysis identified a strong relationship between the geomorphology of the coast and the behavior of the beach/cliff system. Areas of high-relief coast show negative correlations, indicating that higher rates of cliff retreat correlate with lower rates of shoreline erosion. In contrast, low- to moderate-relief coasts show strong positive correlations, wherein areas of high shoreline change correspond to areas of high cliff retreat.

Airborne laser study quantifies El Niño-induced coastal change

USGS Publications Warehouse

Sallenger, Asbury H.; Krabill, William; Brock, John H.; Swift, Robert; Jansen, Mark; Manizade, Serdar; Richmond, Bruce; Hampton, Monty; Eslinger, David

1999-01-01

Winter storms during the 1997–1998 El Niño caused extensive changes to the beaches and cliffs of the west coast of the United States, a NASA-NOAA-USGS investigation using a scanning airborne laser has found. For example, near Pacifica in central California, the cliff eroded locally as much as 10–13 m landward during the El Niño winter, at least 40 times the long term average erosion rate. However, only several hundred meters away the cliff was stable. This variability in cliff response may be related to differences in local beach changes where an accreting beach protected part of the cliff and an eroding beach exposed another part to attack by waves.

Assessing recreation impacts to cliffs in Shenandoah National Park: Integrating visitor observation with trail and recreation site measurements

USGS Publications Warehouse

Wood, K.T.; Lawson, S.R.; Marion, J.L.

2006-01-01

The rock outcrops and cliffs of Shenandoah National Park provide habitat for several rare and endangered plant and animal species, including the federally endangered Shenandoah Salamander (Plethodon shenandoah; Ludwig et al., 1993). The location of the well-known park tour road, Skyline Drive, along the ridgeline provides exceptional access to many outcrops and cliffs throughout the park for a large number of the park?s 1.2 million annual visitors. Consequently, visitor use of cliff areas has led to natural resource impacts, including marked decreases in size and vigor of known rare plant populations. Despite the clear ecological value and potential threats to the natural resources at cliff areas, managers possess little information on visitor use of cliff sites and presently have no formal planning document to guide management. Thus, a park wide study of cliff sites was initiated during the 2005 visitor use season. As part of this research effort, our study used an integrative approach to study recreational use and visitor-caused resource impacts at one of the more heavily visited cliff sites in the park: Little Stony Man Cliffs (LSMC). In particular, this study integrated data from resource impact measurements and visitor use observation to help assess the effects of recreational use on the natural resources of LSMC. Procedures derived from campsite and trail impact studies were used to measure and characterize the amount of visitor-caused resource impacts on LSMC (Marion & Leung, 2001; Marion, 1995). Visitor use observations were conducted on top of LSMC to document and characterize the type and amount of recreational use the cliffs receive and the behaviors of recreationists that may contribute to cliff-top resource impacts. Resource impact measurement data show trampling disturbance present at LSMC, characterized by vegetation loss, exposed soil, and root exposure. Documentation of informal trails, soil erosion, tree damage, and tree stumps provide further indicators of resource damage at LSMC. Results of visitor use observation offer several insights into contributory factors of cliff-top resource damage by showing differences in use and behavior between visitor types. The findings from this study suggest that a management approach characterized by visitor education, some site hardening, and concentration of visitor use on durable surfaces, along with the installation of fixed anchors at the top of popular climbing routes is likely to have the greatest success at balancing visitor enjoyment with resource protection at LSMC.

Ground-based LiDAR application to characterize sea cliff instability processes along a densely populated coastline in Southern Italy

NASA Astrophysics Data System (ADS)

Esposito, Giuseppe; Semaan, Fouad; Salvini, Riccardo; Troise, Claudia; Somma, Renato; Matano, Fabio; Sacchi, Marco

2017-04-01

Sea cliff retreatment along the coastline of the Campi Flegrei volcanic area (Southern Italy) is becoming a threat for public and private structures due to the massive urbanization occurred in the last few decades. In this area, geological features of the outcropping rocks represent one of the most important factors conditioning the sea cliff retreatment. In fact, pyroclastic deposits formed by pumices, scoria, ashes and lapilli are arranged in weakly to moderately welded layers of variable thicknesses, resulting very erodible and prone to landslide processes. Available methods to evaluate topographic changes and retreat rates of sea cliffs include a variety of geomatic techniques, like terrestrial and aerial photogrammetry and LiDAR (Light Detection And Ranging). By means of such techniques, it is in fact possible to obtain high resolution topography of sea cliffs and perform multi-temporal change detection analysis. In this contribution, we present an application of Terrestrial Laser Scanning (TLS or ground-based LiDAR) aimed to identify and quantify instability processes acting along the Torrefumo coastal cliff, in the Campi Flegrei area. Specifically, we acquired a series of 3D point clouds on the years 2013 and 2016, and compared them through a cloud-to-cloud distance computation. Furthermore, a statistical analysis was applied to the change detection results. In this way, an inventory of the cliff failures occurred along the Torrefumo cliff in the 2013-2016 time span was created, as well as the spatial and volumetric distribution of these failures was evaluated. The volumetric analysis shows that large collapses occurred rarely, whereas the spatial analysis shows that the majority of failures occurred in the middle and upper parts of the cliff face. Results also show that both rock fall and surficial erosion processes contribute to the cliff retreatment, acting in turn according to the geological properties of the involved pyroclastic deposits. The presented TLS approach proves to be a cost and time efficient method for characterizing the geomorphic changes involving the sea cliff surfaces over a short-time period (i.e. monthly or yearly). The accuracy of the acquired data allows the characterization of a full range of failures to be located and quantified with a level of detail not reachable using traditional techniques. Results obtained in this research will be used in future applications to assess hazard conditions affecting the anthropic structures built close to the cliff top.

X Marks the Plot: Can Cliffs Notes Help Students Find Literary Gold?

ERIC Educational Resources Information Center

Lilla, Rick

1998-01-01

Examines Villanova University's decision to stop selling Cliffs Notes in its bookstore and attitudes toward Cliffs Notes, highlighting honest work, shortcuts, serious research, critical thinking, and original thinking. Provides the following advice for librarians: avoid being parental; avoid unexamined judgments; and avoid undervaluing Cliffs…

Observed Melt Season Seismicity of Taylor Glacier, Antarctica

NASA Astrophysics Data System (ADS)

Carmichael, J. D.; Pettit, E. C.; Creager, K. C.

2006-12-01

Sufficient evidence exists to suggest that interaction of crevasses and meltwater accelerates ice cliff disintegration of tidewater glaciers. It is not clear what role meltwater plays in calving characteristics from dry- based polar glaciers. We have obtained seismic data from a six-sensor seismic array deployed in October of 2004 near the terminus cliffs of Taylor Glacier, West Antarctica, to analyze near-cliff seismicity throughout a melt season. Discharge data from the adjacent Lawson stream suggests that dramatic increases in meltwater volume temporally correlate with changes in seismic character near ice cliffs. We calculated source-locations for ice-quake during hours of melting and re-freezing and found most large energy events to be located near the ice cliffs. The associated spectra and waveform characteristics are indicative of literature descriptions of crevassing events.

Conspecific reproductive success and breeding habitat selection: Implications for the study of coloniality

USGS Publications Warehouse

Danchin, E.; Boulinier, T.; Massot, M.

1998-01-01

Habitat selection is a crucial process in the life cycle of animals because it can affect most components of fitness. It has been proposed that some animals cue on the reproductive success of conspecifics to select breeding habitats. We tested this hypothesis with demographic and behavioral data from a 17-yr study of the Black-legged Kittiwake (Rissa tridactyla), a cliff-nesting seabird. As the hypothesis assumes, the Black-legged Kittiwake nesting environment was patchy, and the relative quality of the different patches (i.e., breeding cliffs) varied in time. The average reproductive success of the breeders of a given cliff was predictable from one year to the next, but this predictability faded after several years. The dynamic nature of cliff quality in the long term is partly explained by the autocorrelation of the prevalence of an ectoparasite that influences reproductive success. As predicted by the performance-based conspecific attraction hypothesis, the reproductive success of current breeders on a given cliff was predictive of the reproductive success of new recruits on the cliff in the following year. Breeders tended to recruit to the previous year's most productive cliffs and to emigrate from the least productive ones. Consequently, the dynamics of breeder numbers on the cliffs were explained by local reproductive success on a year-to-year basis. Because, on average, young Black-legged Kittiwakes first breed when 4 yr old, such a relationship probably results from individual choices based on the assessment of previous-year local quality. When breeders changed breeding cliffs between years, they selected cliffs of per capita higher reproductive success. Furthermore, after accounting for the potential effects of age and sex as well as between-year variations, the effect of individual breeding performance on breeding dispersal was strongly influenced by the average reproductive success of other breeders on the same cliff. Individual breeding performance did not appear to influence the probability of dispersing for birds breeding on cliffs with high local reproductive success, whereas individual breeding performance did have a strong effect on dispersal for birds that bred on cliffs with lower local reproductive success. This suggests that the reproductive success of locally breeding conspecifics may be sufficient to override an individual's own breeding experience when deciding whether to emigrate. These results, which are supported by behavioral observations of the role of prospecting in recruitment, suggest that both first breeders and adults rely on the reproductive success of conspecifics as 'public information' to assess their own chances of breeding successfully in a given patch and to make settling decisions. A corollary prediction is that individuals should attempt to breed near successful conspecifics (a form of social attraction) in order to benefit from the same favorable local environmental conditions. Such a performance-based conspecific attraction mechanism can thus lead to an aggregative distribution of nests and may have played a role in the evolution of coloniality.

78 FR 49292 - Northshore Mining Company, a Subsidiary of Cliffs Natural Resources, Including On-Site Leased...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... Mining Company, a Subsidiary of Cliffs Natural Resources, Including On-Site Leased Workers From Vanhouse... Cliffs Natural Resources, Including On- Site Leased Workers From Vanhouse, Express Employment and Our... Natural Resources, including on-site leased workers from VanHouse and Express Employment, Silver Bay...

The Glass Cliff: An Examination of the Female Superintendency in South Carolina

ERIC Educational Resources Information Center

Bowles, Blanche Boyd

2013-01-01

South Carolina public school districts are confronted with a series of difficult circumstances and rely more on female superintendents than the national average. The investigation of female South Carolina superintendents was guided by the glass cliff conceptual framework. The glass cliff represents situations where females are promoted over males…

A floral survey of cliff habitats along Bull Run at Manassas National Battlefield Park, Virginia, 2014

USGS Publications Warehouse

Stroh, Esther D.; Struckhoff, Matthew A.; Grabner, Keith W.

2015-08-06

Isolated patches of native vegetation in human-modified landscapes are important reservoirs of biological diversity because they may be the only places in which rare or native species can persist. Manassas National Battlefield Park, Virginia, is an island embedded in a matrix of intensively modified lands; it is becoming increasingly isolated due to growth of the greater Washington, D.C. area. A series of cliffs along Bull Run support an eastern white pine community disjunct from its more typical range in the Appalachian Mountains. Cliffs frequently support vegetation communities that differ from surrounding habitat. In this ecological context, the cliffs along Bull Run are islands of specialized habitat within an island of natural and semi-natural communities (the park), surrounded by a human-dominated landscape. A floral survey of these cliffs was a top priority identified by the National Park Service National Capital Region via the National Resource Preservation Program; in 2014, we completed a floral survey of 11 cliffs in the park. We recorded 282 species in 194 genera and 83 families, including 23 newly documented species for the park.

Material strength on 67P/Churyumov-Gerasimenko and its influence on cliff stability

NASA Astrophysics Data System (ADS)

Hofmann, Marc; Güttler, Carsten; Vincent, Jean-Baptiste; Prasanna Deshapriya, J. D.; Pajola, Maurizio; Tubiana, Cecilia; Feller, Clément; Barucci, Maria A.; Sierks, Holger

2017-04-01

The OSIRIS scientific camera system [1] on board ESA's Rosetta spacecraft has been observing comet 67P/Churyumov-Gerasimenko since its arrival in August 2014. Visible on the OSIRIS images are cliff structures with associated taluses at their bottom. It is likely that these taluses were created during a (partial) collapse of the neighboring cliff. Several of these taluses display individual boulders with different brightness and spectral slope than the rest of the boulders, indicating a varying content of volatiles. A possible cause for the collapse of cliffs is thermal stresses and heat that intensify the fracturing of possibly pre-fractured walls or form new fractures. This results in sublimation with a progressively eroding cliff. The direct consequence is the occurrence of gravitational events and formation of boulder fields at the foot of the cliffs [2,3]. Both of these processes serve to weaken the structural integrity of the cliff but it is unclear how large the relative contribution of these processes is. In this study we investigate how the depletion of volatiles and damage to the cliff structure introduced by cracks will change the integrity and stability of the cliff. We aim to derive limits to the material strength to be compared to those found from observed cliffs and cliff collapses [4,5] using the DEM software ESyS Particle [6]. Acknowledgements: OSIRIS was built by a consortium led by the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofísica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Técnica Aeroespacial, Madrid, Spain, the Universidad Politécnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut für Datentechnik und Kommunikationsnetze der Technischen Universität Braunschweig, Germany. References: [1] Keller, H. U. et al.: OSIRIS The Scientific Camera System Onboard Rosetta, Space Sci. Rev., 128, pp. 433-506, 2007; [2] Vincent, J.-B. et al.: Are fractured cliffs the source of cometary dust jets? Insights from OSIRIS/Rosetta at 67P/Churyumov-Gerasimenko, A&A, 587:A14, 2016; [3] Pajola, M. et al.: Aswan site on comet 67P/Churyumov-Gerasimenko: Morphology, boulder evolution, and spectrophotometry, A&A, 592:A69, 2016; [4] Sierks, H. et al.: On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko, Science, 347, 2015; [5] Groussin, O. et al.: Gravitational slopes, geomorphology, and material strengths of the nucleus of comet 67P/Churyumov-Gerasimenko from OSIRIS observations, A&A, 583:A32, 2015; [6] https://launchpad.net/esys-particle

78 FR 64004 - Notice of Intent To Collect Fees on Public Lands in the Red Cliffs National Conservation Area...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-25

... To Collect Fees on Public Lands in the Red Cliffs National Conservation Area, Washington County, UT... Intent to Collect Fees on Public Lands in the Red Cliffs National Conservation Area, Washington County, UT, which contained erroneous information regarding the use of the America the Beautiful passes at...

78 FR 4467 - UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3, Exemption 1.0 Background UniStar Nuclear Energy (UNE), on behalf of Calvert Cliffs Nuclear Project, LLC and UniStar Nuclear Operating Services...

Recreation impacts to cliff resources in the Potomac Gorge: Final report, June 2011

USGS Publications Warehouse

Marion, Jeffrey L.; Carr, C.; Davis, C.A.

2011-01-01

Managers of the National Park Service (NPS) are directed by law to accommodate appropriate types and amounts of visitation while ensuring that: any adverse impacts are the minimum necessary, unavoidable, cannot be further mitigated, and do not constitute impairment or derogation of park resources and values. (NPS 2006). The increasing popularity of the national park system presents substantial management challenges. High visitatation may cause unacceptable impacts to fragile natural and cultural resources, and may also cause crowding and other social impacts, which can also degrade the quality of visitor experiences. Responding to these concerns, NPS managers at Chesapeake & Ohio Canal National Historical Park (CHOH) and George Washington Memorial Parkway (GWMP) sponsored this research within the upper Potomac Gorge portions of these parks to investigate visitation-related impacts to the park?s cliff resources. The cliffs and rocky areas within the Great Falls and Mather Gorge areas provide important habitats for numerous sensitive rare plants and plant communities. A recent General Management Planning process for Great Falls Park (GFP), a portion of GWMP, highlighted the potential impacts of cliff-associated recreational activities, including hiking, climbing, and fishing, on sensitive cliff resources. The planning process identified the need for development of a Climbing Management Plan and a Trail Plan to more specifically address site and visitor management actions needed to protect rare and sensitive natural and cultural resources. Good science to assess cliff-associated rare plants and communities and to determine the existing and potential effects of cliff-related recreational activities is required for these new planning efforts. This research is designed to specifically address these informational needs and to assist park managers on both sides of the river with current and future cliff and recreation management decisions.

Long-term cliff retreat and erosion hotspots along the central shores of the Monterey Bay National Marine Sanctuary

USGS Publications Warehouse

Moore, Laura J.; Griggs, Gary B.

2002-01-01

Quantification of cliff retreat rates for the southern half of Santa Cruz County, CA, USA, located within the Monterey Bay National Marine Sanctuary, using the softcopy/geographic information system (GIS) methodology results in average cliff retreat rates of 7–15 cm/yr between 1953 and 1994. The coastal dunes at the southern end of Santa Cruz County migrate seaward and landward through time and display net accretion between 1953 and 1994, which is partially due to development. In addition, three critically eroding segments of coastline with high average erosion rates ranging from 20 to 63 cm/yr are identified as erosion ‘hotspots’. These locations include: Opal Cliffs, Depot Hill and Manresa. Although cliff retreat is episodic, spatially variable at the scale of meters, and the factors affecting cliff retreat vary along the Santa Cruz County coastline, there is a compensation between factors affecting retreat such that over the long-term the coastline maintains a relatively smooth configuration. The softcopy/GIS methodology significantly reduces errors inherent in the calculation of retreat rates in high-relief areas (e.g. erosion rates generated in this study are generally correct to within 10 cm) by removing errors due to relief displacement. Although the resulting root mean squared error for erosion rates is relatively small, simple projections of past erosion rates are inadequate to provide predictions of future cliff position. Improved predictions can be made for individual coastal segments by using a mean erosion rate and the standard deviation as guides to future cliff behavior in combination with an understanding of processes acting along the coastal segments in question. This methodology can be applied on any high-relief coast where retreat rates can be measured.

Wolfcampian brachiopods from the Bird Spring Group, Wamp Spring area, Las Vegas Range, Clark County, Nevada ( USA).

USGS Publications Warehouse

Mills, P.C.; Langenheim, R.L.

1987-01-01

The Wamp Spring section of the Bird Spring Group is subdivided into a basal platy limestone member, lower cliff-forming member, and upper cliff-forming member. Triticites, Schwagerina, and Schubertella kingi in the platy limestone member indicate an early Wolfcampian age. Schwagerina, Schubertella kingi, and a distinctive assemblage of brachiopods, similar to the West Texas fauna, indicate that the upper cliff-forming member is late Wolfcampian. The lower cliff-forming member is tentatively assigned to the middle Wolfcampian. The Wamp Spring sequence correlates temporally with the BSe 'formation' of the Bird Spring Group. The fossil-rich upper cliff-forming limestone member includes the new species Pontisia boodi, Crurithyris wampensis, and Calliprotonia(?) n. sp. A, as well as Hustedia culcitula, Crenispirifer(?) sp., Cenorhynchia(?) sp., Kutorginella(?) sp., marginiferids, lyssacine hexactinellid sponges, pleurotomarid and bellerophontid gastropods, cidaroid echinoids, rugose corals, cylindrical cryptostome bryozoans, and nuculids. -from Authors

Dismantling the Prison-House of Colonial History in a Selection of Michelle Cliff's Texts

ERIC Educational Resources Information Center

Labidi, Abid Larbi

2016-01-01

Most, if not all, writings by Jamaican writer Michelle Cliff are connected by a subterranean desire to re-write Afro-Caribbean history from new untold perspectives in reaction to the immense loss and/or distortions that marked the region's history for entire centuries. In this paper, I meticulously read four of Cliff's texts--"Abeng"…

76 FR 29279 - Calvert Cliffs 3 Nuclear Project, LLC and Unistar Nuclear Operating Services, LLC; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-20

... NUCLEAR REGULATORY COMMISSION [DOCKET NO. 52-016; NRC-2008-0250] Calvert Cliffs 3 Nuclear Project, LLC and Unistar Nuclear Operating Services, LLC; Notice of Availability of the Final Environmental Impact Statement for the Combined License Application for Calvert Cliffs Nuclear Power Plant Unit 3 Notice is hereby given that the U.S. Nuclear...

Geology and biostratigraphy of the Potomac River cliffs at Stratford Hall, Westmoreland County, Virginia

USGS Publications Warehouse

Weems, Robert E.; Edwards, Lucy E.; Landacre, Bryan D.

2017-01-01

The cliffs along the Potomac River at Stratford Hall display extensive exposures of Miocene marine strata that belong successively to the Calvert, Choptank, St. Marys, and Eastover Formations. Within the lower part of this sequence, in the Calvert and Choptank Formations, there is well-developed cyclic stratigraphy. Above the Miocene units lies the marginal marine to deltaic Pleistocene Bacons Castle Formation, which is the highest and youngest formation exposed in the cliffs. The goals of this field trip guide are to (1) show the Miocene formations exposed in the cliffs and discuss the paleoenvironments within which they formed, (2) demonstrate the cyclicity in the Miocene marine formations and discuss its origin, (3) compare and contrast the section exposed at the Stratford and Nomini Cliffs with the classic Miocene Calvert Cliffs sequence exposed to the northeast in Calvert County, Maryland, and the Miocene sequence recovered in the Haynesville cores to the southeast in Richmond County, Virginia, (4) discuss and explain why a detailed correlation among these three places has been so difficult to attain, and (5) show typical lithologies of the Bacons Castle Formation and discuss the paleoenvironments in which they formed.

How to explain variations in sea cliff erosion rate?

NASA Astrophysics Data System (ADS)

Prémaillon, Melody; Regard, Vincent; Dewez, Thomas

2017-04-01

Every rocky coast of the world is eroding at different rate (cliff retreat rates). Erosion is caused by a complex interaction of multiple sea weather factors. While numerous local studies exist and explain erosion processes on specific sites, global studies lack. We started to compile many of those local studies and analyse their results with a global point of view in order to quantify the various parameters influencing erosion rates. In other words: is erosion more important in energetic seas? Are chalk cliff eroding faster in rainy environment? etc. In order to do this, we built a database based on literature and national erosion databases. It now contains 80 publications which represents 2500 cliffs studied and more than 3500 erosion rate estimates. A statistical analysis was conducted on this database. On a first approximation, cliff lithology is the only clear signal explaining erosion rate variation: hard lithologies are eroding at 1cm/y or less, whereas unconsolidated lithologies commonly erode faster than 10cm/y. No clear statistical relation were found between erosion rate and external parameters such as sea energy (swell, tide) or weather condition, even on cliff with similar lithology.

Resistivity tomography of Pointe du Hoc cliffs for stability assessment

NASA Astrophysics Data System (ADS)

Udphuay, S.; Everett, M. E.; Warden, R.

2008-12-01

Pointe du Hoc WWII battlefield overlooking the English Channel in western Normandy, France, is an important cultural resource, being an integral component of the June 6 1944 D-Day invasion. Two major buildings, the forward observation post (OP) and Col. Rudder's command post (RCP), are now perched perilously close to the cliff's edge owing to six decades of cliff retreat. Geophysical surveys were carried out in March 2008 to investigate the risk of cliff failure and to inform possible geotechnical remediation strategies with a final goal toward re-opening the observation post that is now closed to visitors. The geophysical surveying is accomplished by high-resolution resistivity tomography, conducted in extreme topography and in the midst of dense cultural clutter. The results of the OP tomography indicate that the highest mass movement hazard is associated with the marine caverns at the base of the cliff at the point of strongest wave attack. These caverns occupy the future site of a sea arch which will threaten the OP building. There is a high probability of a soil wedge failure on the east facing cliff edge close to the OP building. Such a failure could damage or destroy the building. The possibility of a sudden catastrophic failure along any one of these fractures cannot be ruled out. The greatest risk at the RCP site, which is under less immediate threat, is associated with soil wedge failures at the top of the cliffs.

Quantifying ice cliff contribution to debris-covered glacier mass balance from multiple sensors

NASA Astrophysics Data System (ADS)

Brun, Fanny; Wagnon, Patrick; Berthier, Etienne; Kraaijenbrink, Philip; Immerzeel, Walter; Shea, Joseph; Vincent, Christian

2017-04-01

Ice cliffs on debris-covered glaciers have been recognized as a hot spot for glacier melt. Ice cliffs are steep (even sometimes overhanging) and fast evolving surface features, which make them challenging to monitor. We surveyed the topography of Changri Nup Glacier (Nepalese Himalayas, Everest region) in November 2015 and 2016 using multiple sensors: terrestrial photogrammetry, Unmanned Aerial Vehicle (UAV) photogrammetry, Pléiades stereo images and ASTER stereo images. We derived 3D point clouds and digital elevation models (DEMs) following a Structure-from-Motion (SfM) workflow for the first two sets of data to monitor surface elevation changes and calculate the associated volume loss. We derived only DEMs for the two last data sets. The derived DEMs had resolutions ranging from < 5 cm to 30 m. The derived point clouds and DEMs are used to quantify the ice melt of the cliffs at different scales. The very high resolution SfM point clouds, together with the surface velocity field, will be used to calculate the volume losses of 14 individual cliffs, depending on their size, aspect or the presence of supra glacial lake. Then we will extend this analysis to the whole glacier to quantify the contribution of ice cliff melt to the overall glacier mass balance, calculated with the UAV and Pléiades DEMs. This research will provide important tools to evaluate the role of ice cliffs in regional mass loss.

Assessing species habitat using Google Street View: a case study of cliff-nesting vultures.

PubMed

Olea, Pedro P; Mateo-Tomás, Patricia

2013-01-01

The assessment of a species' habitat is a crucial issue in ecology and conservation. While the collection of habitat data has been boosted by the availability of remote sensing technologies, certain habitat types have yet to be collected through costly, on-ground surveys, limiting study over large areas. Cliffs are ecosystems that provide habitat for a rich biodiversity, especially raptors. Because of their principally vertical structure, however, cliffs are not easy to study by remote sensing technologies, posing a challenge for many researches and managers working with cliff-related biodiversity. We explore the feasibility of Google Street View, a freely available on-line tool, to remotely identify and assess the nesting habitat of two cliff-nesting vultures (the griffon vulture and the globally endangered Egyptian vulture) in northwestern Spain. Two main usefulness of Google Street View to ecologists and conservation biologists were evaluated: i) remotely identifying a species' potential habitat and ii) extracting fine-scale habitat information. Google Street View imagery covered 49% (1,907 km) of the roads of our study area (7,000 km²). The potential visibility covered by on-ground surveys was significantly greater (mean: 97.4%) than that of Google Street View (48.1%). However, incorporating Google Street View to the vulture's habitat survey would save, on average, 36% in time and 49.5% in funds with respect to the on-ground survey only. The ability of Google Street View to identify cliffs (overall accuracy = 100%) outperformed the classification maps derived from digital elevation models (DEMs) (62-95%). Nonetheless, high-performance DEM maps may be useful to compensate Google Street View coverage limitations. Through Google Street View we could examine 66% of the vultures' nesting-cliffs existing in the study area (n = 148): 64% from griffon vultures and 65% from Egyptian vultures. It also allowed us the extraction of fine-scale features of cliffs. This World Wide Web-based methodology may be a useful, complementary tool to remotely map and assess the potential habitat of cliff-dependent biodiversity over large geographic areas, saving survey-related costs.

Assessing Species Habitat Using Google Street View: A Case Study of Cliff-Nesting Vultures

PubMed Central

Olea, Pedro P.; Mateo-Tomás, Patricia

2013-01-01

The assessment of a species’ habitat is a crucial issue in ecology and conservation. While the collection of habitat data has been boosted by the availability of remote sensing technologies, certain habitat types have yet to be collected through costly, on-ground surveys, limiting study over large areas. Cliffs are ecosystems that provide habitat for a rich biodiversity, especially raptors. Because of their principally vertical structure, however, cliffs are not easy to study by remote sensing technologies, posing a challenge for many researches and managers working with cliff-related biodiversity. We explore the feasibility of Google Street View, a freely available on-line tool, to remotely identify and assess the nesting habitat of two cliff-nesting vultures (the griffon vulture and the globally endangered Egyptian vulture) in northwestern Spain. Two main usefulness of Google Street View to ecologists and conservation biologists were evaluated: i) remotely identifying a species’ potential habitat and ii) extracting fine-scale habitat information. Google Street View imagery covered 49% (1,907 km) of the roads of our study area (7,000 km2). The potential visibility covered by on-ground surveys was significantly greater (mean: 97.4%) than that of Google Street View (48.1%). However, incorporating Google Street View to the vulture’s habitat survey would save, on average, 36% in time and 49.5% in funds with respect to the on-ground survey only. The ability of Google Street View to identify cliffs (overall accuracy = 100%) outperformed the classification maps derived from digital elevation models (DEMs) (62–95%). Nonetheless, high-performance DEM maps may be useful to compensate Google Street View coverage limitations. Through Google Street View we could examine 66% of the vultures’ nesting-cliffs existing in the study area (n = 148): 64% from griffon vultures and 65% from Egyptian vultures. It also allowed us the extraction of fine-scale features of cliffs. This World Wide Web-based methodology may be a useful, complementary tool to remotely map and assess the potential habitat of cliff-dependent biodiversity over large geographic areas, saving survey-related costs. PMID:23355880

Chemical landscape analysis with the OpenTox framework.

PubMed

Jeliazkova, Nina; Jeliazkov, Vedrin

2012-01-01

The Structure-Activity Relationships (SAR) landscape and activity cliffs concepts have their origins in medicinal chemistry and receptor-ligand interactions modelling. While intuitive, the definition of an activity cliff as a "pair of structurally similar compounds with large differences in potency" is commonly recognized as ambiguous. This paper proposes a new and efficient method for identifying activity cliffs and visualization of activity landscapes. The activity cliffs definition could be improved to reflect not the cliff steepness alone, but also the rate of the change of the steepness. The method requires explicitly setting similarity and activity difference thresholds, but provides means to explore multiple thresholds and to visualize in a single map how the thresholds affect the activity cliff identification. The identification of the activity cliffs is addressed by reformulating the problem as a statistical one, by introducing a probabilistic measure, namely, calculating the likelihood of a compound having large activity difference compared to other compounds, while being highly similar to them. The likelihood is effectively a quantification of a SAS Map with defined thresholds. Calculating the likelihood relies on four counts only, and does not require the pairwise matrix storage. This is a significant advantage, especially when processing large datasets. The method generates a list of individual compounds, ranked according to the likelihood of their involvement in the formation of activity cliffs, and goes beyond characterizing cliffs by structure pairs only. The visualisation is implemented by considering the activity plane fixed and analysing the irregularities of the similarity itself. It provides a convenient analogy to a topographic map and may help identifying the most appropriate similarity representation for each specific SAR space. The proposed method has been applied to several datasets, representing different biological activities. Finally, the method is implemented as part of an existing open source Ambit package and could be accessed via an OpenTox API compliant web service and via an interactive application, running within a modern, JavaScript enabled web browser. Combined with the functionalities already offered by the OpenTox framework, like data sharing and remote calculations, it could be a useful tool for exploring chemical landscapes online.

The Cliff Reconnaissance Vehicle: a tool to improve astronaut exploration efficiency.

PubMed

Souchier, Alain

2014-05-01

The close examination of cliff strata on Mars may reveal important information about conditions that existed in the past on that planet. To have access to such difficult-to-reach locations, the Association Planète Mars (France) has, since 2001, been experimenting with designs of manually operated, instrumented vehicles capable of being lowered down the faces of cliffs. The latest tests in the series in which the Cliff Reconnaissance Vehicle (CRV) or Cliffbot was used were conducted as part of the Austrian Space Forum's MARS2013 field analog project in Morocco in February 2013. Experimentation centered on vehicle configuration for maximum all-terrain capabilities; operational procedures, which included use while the operator was wearing an analog space suit; and imaging, mapping, and geological/biological feature detection capabilities. The exercise demonstrated that Cliffbot is capable of examining hard-to-reach rock strata in cliff faces but that it needs further mechanical modification to improve its ability to overcome some particular terrain obstacles and situational awareness by the operator.

Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus

USGS Publications Warehouse

Oesterle, P.T.; Nemeth, N.M.; VanDalen, Kaci K.; Sullivan, H.; Bentler, K.T.; Young, G.R.; McLean, R.G.; Clark, L.; Smeraski, C.; Hall, Jeffrey S.

2009-01-01

Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet consists of insects, including mosquitoes, leading to an additional potential route of WNV infection. The average peak viremia titer among infected cliff swallows was 106.3 plaque-forming units (PFU)/mL serum and the reservoir competence index was 0.34. There was no correlation between dose and probability of becoming infected or viremia peak and duration. Oral shedding was detected from 2 to 14 days post-inoculation with an average peak titer of 1044 PFU/swab. These results suggest that cliff swallows are competent reservoir hosts of WNV and therefore, they may play a role in early seasonal amplification and maintenance of WNV. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

A numerical study of tsunami wave impact and run-up on coastal cliffs using a CIP-based model

NASA Astrophysics Data System (ADS)

Zhao, Xizeng; Chen, Yong; Huang, Zhenhua; Hu, Zijun; Gao, Yangyang

2017-05-01

There is a general lack of understanding of tsunami wave interaction with complex geographies, especially the process of inundation. Numerical simulations are performed to understand the effects of several factors on tsunami wave impact and run-up in the presence of gentle submarine slopes and coastal cliffs, using an in-house code, a constrained interpolation profile (CIP)-based model. The model employs a high-order finite difference method, the CIP method, as the flow solver; utilizes a VOF-type method, the tangent of hyperbola for interface capturing/slope weighting (THINC/SW) scheme, to capture the free surface; and treats the solid boundary by an immersed boundary method. A series of incident waves are arranged to interact with varying coastal geographies. Numerical results are compared with experimental data and good agreement is obtained. The influences of gentle submarine slope, coastal cliff and incident wave height are discussed. It is found that the tsunami amplification factor varying with incident wave is affected by gradient of cliff slope, and the critical value is about 45°. The run-up on a toe-erosion cliff is smaller than that on a normal cliff. The run-up is also related to the length of a gentle submarine slope with a critical value of about 2.292 m in the present model for most cases. The impact pressure on the cliff is extremely large and concentrated, and the backflow effect is non-negligible. Results of our work are highly precise and helpful in inverting tsunami source and forecasting disaster.

Coastal knickpoints and the competition between fluvial and wave-driven erosion on rocky coastlines

NASA Astrophysics Data System (ADS)

Limber, Patrick W.; Barnard, Patrick L.

2018-04-01

Active margin coastlines are distinguished by rock erosion that acts in two different directions: waves erode the coast horizontally or landwards, a process that creates sea cliffs; and rivers and streams erode the landscape vertically via channel incision. The relative rates of each process exert a dominant control on coastline morphology. Using a model of river channel incision and sea-cliff retreat, we explore how terrestrial and marine erosion compete to shape coastal topography, and specifically what conditions encourage the development of coastal knickpoints (i.e., a river or stream channels that end at a raised sea-cliff edge). We then compare results to actual landscapes. Model results and observations show that coastal knickpoint development is strongly dependent on drainage basin area, where knickpoints typically occur in drainage basins smaller than 5 × 105-6 × 106 m2, as well as channel geometry and sea-cliff retreat rate. In our study area, coastal knickpoints with persistent flow (waterfalls) are uncommon and form only within a small morphological window when 1) drainage basin area is large enough to sustain steady stream discharge, but not large enough to out-compete sea-cliff formation, 2) sea-cliff retreat is rapid, and 3) channel concavity is low so that channel slopes at the coast are high. This particular geomorphic combination can sustain sea-cliff formation even when streams tap into larger drainage basins with greater discharge and more stream power, and provides an initial explanation of why persistent coastal waterfalls are, along many coastlines, relatively rare features.

Coastal knickpoints and the competition between fluvial and wave-driven erosion on rocky coastlines

USGS Publications Warehouse

Limber, Patrick; Barnard, Patrick

2018-01-01

Active margin coastlines are distinguished by rock erosion that acts in two different directions: waves erode the coast horizontally or landwards, a process that creates sea cliffs; and rivers and streams erode the landscape vertically via channel incision. The relative rates of each process exert a dominant control on coastline morphology. Using a model of river channel incision and sea-cliff retreat, we explore how terrestrial and marine erosion compete to shape coastal topography, and specifically what conditions encourage the development of coastal knickpoints (i.e., a river or stream channels that end at a raised sea-cliff edge). We then compare results to actual landscapes. Model results and observations show that coastal knickpoint development is strongly dependent on drainage basin area, where knickpoints typically occur in drainage basins smaller than 5 × 105–6 × 106 m2, as well as channel geometry and sea-cliff retreat rate. In our study area, coastal knickpoints with persistent flow (waterfalls) are uncommon and form only within a small morphological window when 1) drainage basin area is large enough to sustain steady stream discharge, but not large enough to out-compete sea-cliff formation, 2) sea-cliff retreat is rapid, and 3) channel concavity is low so that channel slopes at the coast are high. This particular geomorphic combination can sustain sea-cliff formation even when streams tap into larger drainage basins with greater discharge and more stream power, and provides an initial explanation of why persistent coastal waterfalls are, along many coastlines, relatively rare features.

Forecasting sea cliff retreat in Southern California using process-based models and artificial neural networks

NASA Astrophysics Data System (ADS)

Limber, P. W.; Barnard, P.; Erikson, L. H.

2016-02-01

Modeling coastal geomorphic change over multi-decadal time and regional spatial scales (i.e. >20 km alongshore) is in high demand due to rising global sea levels and heavily populated coastal zones, but is challenging for several reasons: adequate geomorphic and oceanographic data often does not exist over the entire study area or time period; models can be too computationally expensive; and model uncertainty is high. In the absence of rich datasets and unlimited computer processing power, researchers are forced to leverage existing data, however sparse, and find analytical methods that minimize computation time without sacrificing (too much) model reliability. Machine learning techniques, such as artificial neural networks, can assimilate and efficiently extrapolate geomorphic model behavior over large areas. They can also facilitate ensemble model forecasts over a broad range of parameter space, which is useful when a paucity of observational data inhibits the constraint of model parameters. Here, we assimilate the behavior of two established process-based sea cliff erosion and retreat models into a neural network to forecast the impacts of sea level rise on sea cliff retreat in Southern California ( 400 km) through the 21st century. Using inputs such as historical cliff retreat rates, mean wave power, and whether or not a beach is present, the neural network independently reproduces modeled sea cliff retreat as a function of sea level rise with a high degree of confidence (R2 > 0.9, mean squared error < 0.1 m yr-1). Results will continuously improve as more model scenarios are assimilated into the neural network, and more field data (i.e., cliff composition and rock hardness) becomes available to tune the cliff retreat models. Preliminary results suggest that sea level rise rates of 2 to 20 mm yr-1 during the next century could accelerate historical cliff retreat rates in Southern California by an average of 0.10 - 0.56 m yr-1.

Final Environmental Assessment to Renovate Fourth Cliff Recreational Area at Hanscom Air Force Base, Massachusetts

DTIC Science & Technology

2014-11-17

Renovate Fourth Cliff Recreational Annex Grading and topography changes may be necessary to design an appropriate drainage system at the site...goals: 1) Increase safety for personnel and patrons at the site; 2) Provide protection of the exposed cliff face from rainwater runoff; 3) Provide...be followed. Drainage design must meet Massachusetts Stormwater Management Standards, as well as comply with the Federal Clean Water Act. Solid

Rockfall hazard assessment of nearly vertical rhyolite tuff cliff faces by using terrestrial laser scanner, UAV and FEM analyses

NASA Astrophysics Data System (ADS)

Török, Ákos; Barsi, Árpád; Görög, Péter; Lovas, Tamás; Bögöly, Gyula; Czinder, Balázs; Vásárhelyi, Balázs; Molnár, Bence; József Somogyi, Árpád

2017-04-01

Nearly vertical rhyolite tuff cliff faces are located in NE-Hungary representing rock fall hazard in the touristic region of Sirok. Larger blocks of the cliff have fallen in recent years menacing tourists and human lives. The rhyolite tuff, that forms the Castle Hill was formed during Miocene volcanism and comprises of brecciated lapilli tuffs and tuffs with intercalating ignimbritic horizons. The paper focuses on the 3D mapping of cliff faces and modeling of rock fall hazard. The topography and 3D model of the cliff was obtained by using GNSS supported terrestrial laser scanner and UAV. With imaging techniques of UAV a Triangulated Irregular Network (TIN) model was developed that contained triangles with 5-10 cm side lengths. GNSS supported terrestrial laser scanning allowed the observation with a resolution 1-5 cm of point spacing. The point clouds were further processed and with the combination of laser scanner and UAV data a 3D model of the studied cliff faces were obtained. Geological parameters for rock fall analyses included both field observations and laboratory tests. The lithotypes were identified on the field and were sampled for rock mechanical laboratory analyses. Joint- and fault system was mapped and visualized by using Rocscience Dip. EN test methods were used to obtain the density properties of various lithotypes of rhyolite tuff. Other standardized EN tests included ultrasonic pulse velocity, water absorption, indirect tensile strength (Brasilian), uniaxial compressive strength and modulus of elasticity of air dry and of water saturated samples. GSI values were denoted based on filed observations and rock mass properties. The stability analyses of cliff faces were made by using 2D FEM software (Phase 2). Cross sections were evaluated and global factor of safety was also calculated. The modeled displacements were in the order of few centimeters; however several locations were pinpointed where wedge failure and planar slip surfaces were identified as major cliff stability hazards. These were associated with the major joint systems dissecting cliff faces. This research have proved that the combined methods of field surveying, imaging techniques, data processing and FEM modelling with rock mechanical laboratory analyses allowed the identification of major rock fall hazards even at areas which are difficult to access.

Slope mass movements on rocky sea-cliffs: A power-law distributed natural hazard on the Barlavento Coast, Algarve, Portugal

NASA Astrophysics Data System (ADS)

Teixeira, Sebastião Braz

2006-06-01

The coast of the Central Algarve, Portugal, is dominated by sea-cliffs, cut on Miocene calcarenites; here, the main coastal geologic hazards result from the conflict between human occupation and sea-cliff recession. The evolution of this rocky coast occurs through an intermittent and discontinuous series of slope mass movements, along a 46 km cliff front. For the last 30 years, the increase of tourism occupation has amplified the risks to both people and buildings. In the last decade we have seen several accidents caused by cliff failure, which killed or wounded people and destroyed several buildings. The definition of buffer zones limited by hazard lines parallel to the cliff edge, where land use is restricted, is a widely used and effective preventive measure for mitigating risk. Rocky coasts typically show a slow cliff evolution. The process of gathering statistically significant field inventories of mass movements is, thus, very long. Although mass movement catalogues provide fundamental information on sea cliff evolution patterns and are an outstanding tool in hazard assessment, published data sets are still rare. In this work, we use two inventories of mass movement width, recorded on sea cliffs cut on Miocene calcarenites: a nine year long continuous field inventory (1995-2004) with 140 recorded events, and a 44 year long catalogue based on comparative analysis of aerial photographs (1947-1991), that includes 177 events. The cumulative frequency-width distributions of both data sets fit, above a critical width value corresponding to the threshold of full completeness of the inventories, to power-law distributions. The knowledge of the limits of the catalogues enabled the construction of a 53 year long record inventory over the range of mean width ⩾3 m ( n=167 events) and maximum width ⩾4 m ( n=155 events). The data assembled corresponds to a partial series and was converted to a return period-size distribution. Both return period-width distributions (mean width and maximum width) are also power-law distributions. Equations of return period-width distributions give the width of hazard lines corresponding to the width of mass movement, in which return period equals the period that hazard line is referred to.

Mercury Long Cliffs

NASA Image and Video Library

2008-01-27

As NASA MESSENGER spacecraft team continued to study the high-resolution images taken during the Mercury flyby encounter on January 14, 2008, scarps cliffs that extend for long distances were discovered.

Rockfall activity of cliff inferred from deposit and cone method

NASA Astrophysics Data System (ADS)

Jaboyedoff, M.; Baillifard, F.; Rouiller, J.-D.

2003-04-01

Assuming that fresh scree slopes are significant indicators of recent rockfall activity, they can be used as activity indicators for a given rockfall source area. Using simple geometric rules and a DTM (digital elevation model), the propagation zone can be estimated by considering that each potential rockfall source cell (corresponding to the entire cliff) can generate a scree slope within a cone with a slope ranging from 27° to 37°. Thus, the count of pixels representing rockfall deposits that are contained in this cone represents a relative scale of recent rockfall activity. According to Evans and Hungr (1993), the source cell can be chosen at the bottom of the cliff, with lower angles. Choosing the entire cliff or the bottom of the cliff as source area depends on the morphology of the slope situated below the cliff. The cone can also be laterally limited in order to avoid the counting of illogical rock slope trajectories (+-20°). In Switzerland, the vectorized 1:25,000 topographic map (vector25) can provide scree slope and cliff area data sets. Results obtained using this method show good agreement with field observations, although it is evident that the highest topographic reliefs are favored by this method, as verified in the Alps. Compared to the method of Menendéz Duarte and Marquínez (2002), which uses GIS-calculated watersheds as propagation areas, the present method does not take small changes of topography into account. References Evans, S.G. and Hungr, O. The assessment of rockfall hazard at the base of talus slopes. Canadian Geotechnical Journal, 30/4, 620-636, 1993. Menendéz Duarte, R. and Marquínez, J. The influence of environmental and lithologic factors on rockfall at a regional scale: an evaluation using GIS. Geomorphology, 43, 117-136, 2002.

The Early Oligocene Copperas Creek Volcano and geology along New Mexico Higway 15 between Sapillo Creek and the Gila Cliff Dwellings National Monument, Grant and Catron Counties, New Mexico

USGS Publications Warehouse

Ratté, James C.; Mack, Greg; Witcher, James; Lueth, Virgil W.

2008-01-01

The section of New Mexico Highway 15 between the intersection of NM-15 and NM 35 (aka Sapillo junction) at the south and the Gila Cliff Dwellings National Monument at the north end of NM –15 occupies an approximately 18 mile long, mile wide, corridor through the eastern part of the Gila Wilderness (Fig. 1). Whereas most of the Gila Wilderness is dominated by silicic, caldera-forming supervolcanoes of Eocene to Oligocene age, this part of NM-15 traverses a volcanic terrain of similar age, but composed mainly of intermediate composition lava flows and minor associated rhyolitic intrusions and pyroclastic rocks, which are related to the here-named Copperas Creek volcano. This volcanic complex is bounded by Basin and Range structures: on the south by the Sapillo Creek graben, and on the north by the Gila Hot Springs graben, both of which are filled with Gila Conglomerate of late Tertiary to Pleistocene(?) age. Hot springs in the Gila River valley are localized along faults in the deepest part of the Gila Hot Springs graben. The cliff dwellings of the National Monument were constructed in caves in Gila Conglomerate in the western part of the Gila Hot Springs graben. The eastern edge of the Gila Cliff Dwellings caldera is buried by younger rocks east of the cliff dwellings, but spectacular cliffs of Bloodgood Canyon Tuff, which fills the caldera, can be viewed along the West Fork of the Gila River from the trail starting at the cliff dwellings. Although this is not intended as a formal road log, highway mileage markers (MM) will be used to locate geologic features more or less progressively from south to north along NM-15.

Progressive failure of sheeted rock slopes: the 2009–2010 Rhombus Wall rock falls in Yosemite Valley, California, USA

USGS Publications Warehouse

Stock, Greg M.; Martel, Stephen J.; Collins, Brian D.; Harp, Edwin L.

2012-01-01

Progressive rock-fall failures in natural rock slopes are common in many environments, but often elude detailed quantitative documentation and analysis. Here we present high-resolution photography, video, and laser scanning data that document spatial and temporal patterns of a 15-month-long sequence of at least 14 rock falls from the Rhombus Wall, a sheeted granitic cliff in Yosemite Valley, California. The rock-fall sequence began on 26 August 2009 with a small failure at the tip of an overhanging rock slab. Several hours later, a series of five rock falls totaling 736 m3progressed upward along a sheeting joint behind the overhanging slab. Over the next 3 weeks, audible cracking occurred on the Rhombus Wall, suggesting crack propagation, while visual monitoring revealed opening of a sheeting joint adjacent to the previous failure surface. On 14 September 2009 a 110 m3 slab detached along this sheeting joint. Additional rock falls between 30 August and 20 November 2010, totaling 187 m3, radiated outward from the initial failure area along cliff (sub)parallel sheeting joints. We suggest that these progressive failures might have been related to stress redistributions accompanying propagation of sheeting joints behind the cliff face. Mechanical analyses indicate that tensile stresses should occur perpendicular to the cliff face and open sheeting joints, and that sheeting joints should propagate parallel to a cliff face from areas of stress concentrations. The analyses also account for how sheeting joints can propagate to lengths many times greater than their depths behind cliff faces. We posit that as a region of failure spreads across a cliff face, stress concentrations along its margin will spread with it, promoting further crack propagation and rock falls.

Analysing the spatial patterns of erosion scars using point process theory at the coastal chalk cliff of Mesnil-Val, (Normandy, Northern France)

NASA Astrophysics Data System (ADS)

Rohmer, J.; Dewez, D.

2014-09-01

Over the last decade, many cliff erosion studies have focused on frequency-size statistics using inventories of sea cliff retreat sizes. By comparison, only a few paid attention to quantifying the spatial and temporal organisation of erosion scars over a cliff face. Yet, this spatial organisation carries essential information about the external processes and the environmental conditions that promote or initiate sea-cliff instabilities. In this article, we use summary statistics of spatial point process theory as a tool to examine the spatial and temporal pattern of a rockfall inventory recorded with repeated terrestrial laser scanning surveys at the chalk coastal cliff site of Mesnil-Val (Normandy, France). Results show that: (1) the spatial density of erosion scars is specifically conditioned alongshore by the distance to an engineered concrete groin, with an exponential-like decreasing trend, and vertically focused both at wave breaker height and on strong lithological contrasts; (2) small erosion scars (10-3-10-2 m3) aggregate in clusters within a radius of 5 to 10 m, which suggests some sort of attraction or focused causative process, and disperse above this critical distance; (3) on the contrary, larger erosion scars (10-2-101 m3) tend to disperse above a radius of 1 to 5 m, possibly due to the spreading of successive failures across the cliff face; (4) large scars significantly occur albeit moderately, where previous large rockfalls have occurred during preceeding winter; (5) this temporal trend is not apparent for small events. In conclusion, this study shows, with a worked example, how spatial point process summary statistics are a tool to test and quantify the significance of geomorphological observation organisation.

Analysing the spatial patterns of erosion scars using point process theory at the coastal chalk cliff of Mesnil-Val, Normandy, northern France

NASA Astrophysics Data System (ADS)

Rohmer, J.; Dewez, T.

2015-02-01

Over the last decade, many cliff erosion studies have focused on frequency-size statistics using inventories of sea cliff retreat sizes. By comparison, only a few paid attention to quantifying the spatial and temporal organisation of erosion scars over a cliff face. Yet, this spatial organisation carries essential information about the external processes and the environmental conditions that promote or initiate sea-cliff instabilities. In this article, we use summary statistics of spatial point process theory as a tool to examine the spatial and temporal pattern of a rockfall inventory recorded with repeated terrestrial laser scanning surveys at the chalk coastal cliff site of Mesnil-Val (Normandy, France). Results show that: (1) the spatial density of erosion scars is specifically conditioned alongshore by the distance to an engineered concrete groyne, with an exponential-like decreasing trend, and vertically focused both at wave breaker height and on strong lithological contrasts; (2) small erosion scars (10-3 to 10-2 m3) aggregate in clusters within a radius of 5 to 10 m, which suggests some sort of attraction or focused causative process, and disperse above this critical distance; (3) on the contrary, larger erosion scars (10-2 to 101 m3) tend to disperse above a radius of 1 to 5 m, possibly due to the spreading of successive failures across the cliff face; (4) large scars significantly occur albeit moderately, where previous large rockfalls have occurred during preceding winter; (5) this temporal trend is not apparent for small events. In conclusion, this study shows, with a worked example, how spatial point process summary statistics are a tool to test and quantify the significance of geomorphological observation organisation.

3-D Resistivity Tomography for Cliff Stability Study at the D-Day Pointe du Hoc Historic Site in Normandy, France

NASA Astrophysics Data System (ADS)

Udphuay, S.; Everett, M. E.; Guenther, T.; Warden, R. R.

2007-12-01

The D-Day invasion site at Pointe du Hoc in Normandy, France is one of the most important World War II battlefields. The site remains today a valuable historic cultural resource. However the site is vulnerable to cliff collapses that could endanger the observation post building and U.S. Ranger memorial located just landward of the sea stack, and an anti-aircraft gun emplacement, Col. Rudder's command post, located on the cliff edge about 200 m east of the observation post. A 3-D resistivity tomography incorporating extreme topography is used in this study to provide a detailed site stability assessment with special attention to these two buildings. Multi-electrode resistivity measurements were made across the cliff face and along the top of the cliff around the two at-risk buildings to map major subsurface fracture zones and void spaces that could indicate possible accumulations and pathways of groundwater. The ingress of acidic groundwater through the underlying carbonate formations enlarges pre-existing tectonic fractures via limestone dissolution and weakens the overall structural integrity of the cliff. The achieved 3-D resistivity tomograms provide diagnostic subsurface resistivity distributions. Resistive zones associated with subsurface void spaces have been located. These void spaces constitute a stability geohazard as they become significant drainage routes during and after periods of heavy rainfalls.

Europa Ice Cliffs-High Resolution

NASA Technical Reports Server (NTRS)

1998-01-01

This view of the Conamara Chaos region on Jupiter's moon Europa shows cliffs along the edges of high-standing ice plates. The washboard texture of the older terrain has been broken into plates which are separated by material with a jumbled texture. The cliffs themselves are rough and broadly scalloped, and smooth debris shed from the cliff faces is piled along the base. For scale, the height of the cliffs and size of the scalloped indentations are comparable to the famous cliff face of Mount Rushmore in South Dakota.

This image was taken on December 16, 1997 at a range of 900 kilometers (540 miles) by the solid state imaging system (camera) on NASA's Galileo spacecraft. North is to the top right of the picture, and the sun illuminates the surface from the east. This image, centered at approximately 8 degrees north latitude and 273 degrees west longitude, covers an area approximately 1.5 kilometers by 4 kilometers (0.9 miles by 2.4 miles). The resolution is 9 meters (30 feet) per picture element.

The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

Gravitational failure of sea cliffs in weakly lithified sediment

USGS Publications Warehouse

Hampton, M.A.

2002-01-01

Gravitational failure of sea cliffs eroded into weakly lithified sediment at several sites in California involves episodic stress-release fracturing and cantilevered block falls. The principal variables that influence the gravitational stability are tensional stresses generated during the release of horizontal confining stress and weakening of the sediment with increased saturation levels. Individual failures typically comprise less than a cubic meter of sediment, but large areas of a cliff face can be affected by sustained instability over a period of several days. Typically, only the outer meter or so of sediment is removed during a failure episode. In-place sediment saturation levels vary over time and space, generally being higher during the rainy season but moderate to high year-round. Laboratory direct-shear tests show that sediment cohesion decreases abruptly with increasing saturation level; the decrease is similar for all tested sediment if the cohesion is normalized by the maximum, dry-sediment cohesion. Large failures that extend over most or all of the height of the sea cliff are uncommon, but a few large wedge-shaped failures sometimes occur, as does separation of large blocks at sea cliff-gully intersections.

Rock fall simulation at Timpanogos Cave National Monument, American Fork Canyon, Utah, USA

USGS Publications Warehouse

Harp, E.L.; Dart, R.L.; Reichenbach, P.

2011-01-01

Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at the cave entrance and exit in 1976. Numerous rock fall incidents, including a near miss in 2000 in the vicinity of the trail below the cave exit, have led to a decision to extend the shelter at the cave exit to protect visitors from these ongoing rock fall events initiating from cliffs immediately above the cave exit. Three-dimensional rock fall simulations from sources at the top of these cliffs have provided data from which to assess the spatial frequencies and velocities of rock falls from the cliffs and to constrain the design of protective measures to reduce the rock fall hazard. Results from the rock fall simulations are consistent with the spatial patterns of rock fall impacts that have been observed at the cave exit site. ?? 2011 Springer-Verlag.

Rock fall simulation at Timpanogos Cave National Monument, American Fork Canyon, Utah, USA

USGS Publications Warehouse

Harp, Edwin L.; Dart, Richard L.; Reichenbach, Paola

2011-01-01

Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at the cave entrance and exit in 1976. Numerous rock fall incidents, including a near miss in 2000 in the vicinity of the trail below the cave exit, have led to a decision to extend the shelter at the cave exit to protect visitors from these ongoing rock fall events initiating from cliffs immediately above the cave exit. Three-dimensional rock fall simulations from sources at the top of these cliffs have provided data from which to assess the spatial frequencies and velocities of rock falls from the cliffs and to constrain the design of protective measures to reduce the rock fall hazard. Results from the rock fall simulations are consistent with the spatial patterns of rock fall impacts that have been observed at the cave exit site.

Cliffs of ice spied on Mars

NASA Astrophysics Data System (ADS)

Voosen, Paul

2018-01-01

Scientists have discovered eight cliffs of nearly pure water ice on Mars, some of which stand nearly 100 meters tall. The discovery points to large stores of underground ice buried only a meter or two below the surface at surprisingly low martian latitudes, in regions where ice had not yet been detected. Each cliff seems to be the naked face of a glacier, tantalizing scientists with the promise of a layer-cake record of past martian climates and space enthusiasts with a potential resource for future human bases. Scientists discovered the cliffs with a high-resolution camera on the Mars Reconnaissance Orbiter, revisiting the sites to show their subsequent retreat as a result of vaporization, and their persistence in the martian summer. The hunt should now be on, scientists say, for similar sites closer to the equator.

Accelerated recession of a desert cliff due to sewage water disposal, Sede Boqer, Israel

NASA Astrophysics Data System (ADS)

Arkin, Yaacov; Karnieli, Arnon; Issar, Arie; Mtz.-Esparza, Javier Diaz

1986-12-01

Accelerated erosion of a desert cliff due to uncontrolled sewage water disposal was investigated at the Sede Boqer Campus in the Negev, Israel An erosional cirque formed by this water was studied as a model simulating natural processes. The cliffs consist of loess and conglomerate underlain by soft marl, clay, and chalk. The rate of erosion is of the order of 5% 8% of the volume of water discharged. The rate of incision ranges from 10 2 to 13.3 m/yr and is several orders higher than that expected under normal rainfall conditions The introduction of this new hydrological factor resulted in a severe disturbance of the morphological balance in the vicinity of the cliffs, accelerated erosion, and generated circular slides

Layers in Burns Cliff Examined by Opportunity

NASA Image and Video Library

2011-11-21

NASA Mars Exploration Rover Opportunity studied layers in the Burns Cliff slope of Endurance Crater in 2004. The layers show different types of deposition of sulfate-rich sediments. Opportunity panoramic camera recorded this image.

Structure-Based Predictions of Activity Cliffs

PubMed Central

Husby, Jarmila; Bottegoni, Giovanni; Kufareva, Irina; Abagyan, Ruben; Cavalli, Andrea

2015-01-01

In drug discovery, it is generally accepted that neighboring molecules in a given descriptors' space display similar activities. However, even in regions that provide strong predictability, structurally similar molecules can occasionally display large differences in potency. In QSAR jargon, these discontinuities in the activity landscape are known as ‘activity cliffs’. In this study, we assessed the reliability of ligand docking and virtual ligand screening schemes in predicting activity cliffs. We performed our calculations on a diverse, independently collected database of cliff-forming co-crystals. Starting from ideal situations, which allowed us to establish our baseline, we progressively moved toward simulating more realistic scenarios. Ensemble- and template-docking achieved a significant level of accuracy, suggesting that, despite the well-known limitations of empirical scoring schemes, activity cliffs can be accurately predicted by advanced structure-based methods. PMID:25918827

A model ensemble for projecting multi‐decadal coastal cliff retreat during the 21st century

USGS Publications Warehouse

Limber, Patrick; Barnard, Patrick; Vitousek, Sean; Erikson, Li

2018-01-01

Sea cliff retreat rates are expected to accelerate with rising sea levels during the 21st century. Here we develop an approach for a multi‐model ensemble that efficiently projects time‐averaged sea cliff retreat over multi‐decadal time scales and large (>50 km) spatial scales. The ensemble consists of five simple 1‐D models adapted from the literature that relate sea cliff retreat to wave impacts, sea level rise (SLR), historical cliff behavior, and cross‐shore profile geometry. Ensemble predictions are based on Monte Carlo simulations of each individual model, which account for the uncertainty of model parameters. The consensus of the individual models also weights uncertainty, such that uncertainty is greater when predictions from different models do not agree. A calibrated, but unvalidated, ensemble was applied to the 475 km‐long coastline of Southern California (USA), with 4 SLR scenarios of 0.5, 0.93, 1.5, and 2 m by 2100. Results suggest that future retreat rates could increase relative to mean historical rates by more than two‐fold for the higher SLR scenarios, causing an average total land loss of 19 – 41 m by 2100. However, model uncertainty ranges from +/‐ 5 – 15 m, reflecting the inherent difficulties of projecting cliff retreat over multiple decades. To enhance ensemble performance, future work could include weighting each model by its skill in matching observations in different morphological settings

Cliff stability assessment using electrical resistivity tomography at the historic WWII D-Day invasion site, Pointe du Hoc, France

NASA Astrophysics Data System (ADS)

Everett, M. E.; Udphuay, S.; Warden, R.

2007-05-01

The 1944 D-Day invasion site at Pointe du Hoc, Normandy, France is an important WWII battlefield and cultural resource but is at risk from chalk cliff collapse. The American Battle Monuments Commission tasked us to evaluate the geohazard to the observation post and other cliff-side buildings of historical significance. Geophysical multi-electrode resistivity profiling is used to study cliff stability and the condition of the observation- post foundations. Preliminary 2-D geological interpretations are provided of individual profiles. The copious steel, concrete and void spaces at the site renders hydrogeological interpretation challenging but tractable. The cliff face appears to be relatively intact and well-drained. Several routes taken by groundwater into fractures within the chalk were identified mainly on the western side of the site. The eastern side is drier and somewhat sheltered from the Atlantic storms but may contain large void spaces that could efficiently transmit groundwater flow during heavy precipitation events, thereby imperiling the major antiaircraft gun emplacement occupied by Col. Rudder in the early days of the Allied invasion. The forward German observation post perched close to the sea stack, which now hosts the U.S. Ranger memorial, may be moving with the soil and not securely anchored to bedrock. A complex failure mechanism is identified as a combination of groundwater dissolution of the fractured chalk and sea wave attack at the cliff base.

Zooming in and out: Scale dependence of extrinsic and intrinsic factors affecting salt marsh erosion

NASA Astrophysics Data System (ADS)

Wang, Heng; van der Wal, Daphne; Li, Xiangyu; van Belzen, Jim; Herman, Peter M. J.; Hu, Zhan; Ge, Zhenming; Zhang, Liquan; Bouma, Tjeerd J.

2017-07-01

Salt marshes are valuable ecosystems that provide important ecosystem services. Given the global scale of marsh loss due to climate change and coastal squeeze, there is a pressing need to identify the critical extrinsic (wind exposure and foreshore morphology) and intrinsic factors (soil and vegetation properties) affecting the erosion of salt marsh edges. In this study, we quantified rates of cliff lateral retreat (i.e., the eroding edge of a salt marsh plateau) using a time series of aerial photographs taken over four salt marsh sites in the Westerschelde estuary, the Netherlands. In addition, we experimentally quantified the erodibility of sediment cores collected from the marsh edge of these four marshes using wave tanks. Our results revealed the following: (i) at the large scale, wind exposure and the presence of pioneer vegetation in front of the cliff were the key factors governing cliff retreat rates; (ii) at the intermediate scale, foreshore morphology was partially related to cliff retreat; (iii) at the local scale, the erodibility of the sediment itself at the marsh edge played a large role in determining the cliff retreat rate; and (iv) at the mesocosm scale, cliff erodibility was determined by soil properties and belowground root biomass. Thus, both extrinsic and intrinsic factors determined the fate of the salt marsh but at different scales. Our study highlights the importance of understanding the scale dependence of the factors driving the evolution of salt marsh landscapes.

Soft-Cliff Retreat, Self-Organized Critical Phenomena in the Limit of Predictability?

NASA Astrophysics Data System (ADS)

Paredes, Carlos; Godoy, Clara; Castedo, Ricardo

2015-03-01

The coastal erosion along the world's coastlines is a natural process that occurs through the actions of marine and subaerial physico-chemical phenomena, waves, tides, and currents. The development of cliff erosion predictive models is limited due to the complex interactions between environmental processes and material properties over a wide range of temporal and spatial scales. As a result of this erosive action, gravity driven mass movements occur and the coastline moves inland. Like other studied earth natural and synthetically modelled phenomena characterized as self-organized critical (SOC), the recession of the cliff has a seemingly random, sporadic behavior, with a wide range of yearly recession rate values probabilistically distributed by a power-law. Usually, SOC systems are defined by a number of scaling features in the size distribution of its parameters and on its spatial and/or temporal pattern. Particularly, some previous studies of derived parameters from slope movements catalogues, have allowed detecting certain SOC features in this phenomenon, which also shares the recession of cliffs. Due to the complexity of the phenomenon and, as for other natural processes, there is no definitive model of recession of coastal cliffs. In this work, various analysis techniques have been applied to identify SOC features in the distribution and pattern to a particular case: the Holderness shoreline. This coast is a great case study to use when examining coastal processes and the structures associated with them. It is one of World's fastest eroding coastlines (2 m/yr in average, max observed 22 m/yr). Cliffs, ranging from 2 m up to 35 m in height, and made up of glacial tills, mainly compose this coast. It is this soft boulder clay that is being rapidly eroded and where coastline recession measurements have been recorded by the Cliff Erosion Monitoring Program (East Riding of Yorkshire Council, UK). The original database has been filtered by grouping contiguous sections, with similar geomorphological and dynamic features, to configure a complete and suitable catalogue of yearly recession rates (in m/yr) to analyze. Results show SOC fingerprint characteristics in the limited range scaling of the probability distribution function, in the variographic analysis and in the zero-mean Gaussian distribution of the Fourier coefficients. Therefore it cannot be neglected the possibility that Holderness cliffs behave as a SOC system. According to the discussed results, predictability possibilities of sea-cliff recession phenomena have been concluded.

Wave-flume experiments of soft-rock cliff erosion under monochromatic waves

NASA Astrophysics Data System (ADS)

Regard, Vincent; Astruc, Dominique; Caplain, Bastien

2017-04-01

We investigate how cliffs erode under wave attack. Rocky coast erosion works through cycles, each one corresponding to three successive phases: (i) notch creation at cliff toe by mechanical action of waves, (ii) cliff fracturation leading to collapse, and (iii) evacuation of scree aprons by waves and currents. We performed experiments in a 5m x 14cm x 25cm wave flume (15 cm water depth) to investigate how waves are eroding a rocky coast. The cliff is made of wet sand and models a relatively soft rock. We used 3 different grain size (D50 = 0.28-0.41-0.48 mm), changing the cliff rheology. Waves are monochromatic; their height and period differ for the various experiments. Actual wave parameters are estimated by capacitive probes located offshore. The experiments are monitored by two video cameras both on the side and above the flume. Pictures are taken at a rate of 1Hz during the first 4h and then the rate is decreased to 0.1Hz till the end of experiment (about 1 day). The monitoring ensure a confident characterization of experiments in terms of waves (surf similarity parameter ξ and the incident wave energy flux F) and in terms of sediment (Dean number Ω and Shields number θb at breakers). Experiments begin by an initial phase of quick cliff retreat. Then the system evolves with slower cliff retreat. We focus on bottom morphology which we characterize in function of wave forcing (ξ, F). We show that the bottom morphology mainly depends on ξ. For our reference sediment (Dm = 0.41 mm), we observed: (i) surging breakers on a steep terrace (type T1) for ξ > 0.65; (ii)collapsing breakers on a bared profile attached to the inner platform (type T2) for 0.55< ξ <0.6; (iii) spilling breakers on gentle terrace (type T3) for F < 1.3 W/m and 0.55< ξ <0.6. Another bottom morphology, type T4, displays two sub-systems, an outer system with a double-bar profile where breaking waves are plunging, and an inner system with a T1, T2 or T3 profile. Some of these bottom morphologies are unsteady with sandbar oscillation. When changing sediment grain size, we observed that the bottom typology is similar but evolves in function of the Ω value. Finally, we observed that the cliff recession is proportional to F, is not monotonic with ξ and decreases with the sediment grain diameter.

Superstorms at the end of the Last Interglacial (MIS 5e)? Modeling paleo waves and the transport of giant boulders.

NASA Astrophysics Data System (ADS)

Rovere, Alessio; Harris, Daniel; Casella, Elisa; Lorscheid, Thomas; Stocchi, Paolo; Nandasena, Napayalage; Sandstrom, Michael; D'Andrea, William; Dyer, Blake; Raymo, Maureen

2017-04-01

We present the results of high-resolution field surveys and wave models along the cliffs of the northern part of the Island of Eleuthera, Bahamas. Previous studies have proposed that cliff top mega-boulders were emplaced at the end of the Last Interglacial (MIS 5e, 128-116 ka) by giant swells caused by super-storms that find no counterpart in the Holocene (including historical times). Our results suggest that these boulders could have instead been transported from the cliff face to the top of the cliff by a storm analogous to the 1991 'Perfect Storm', if sea level during MIS 5e sea was more than 4 meters higher than today. We remark that the data-model approach used here is essential to interpreting the geologic evidence of extreme storms during past warm periods, which in turn, is an important tool for predicting the intensity of extreme storm events in future climates. Our results indicate that even without an increase in storm intensity, cliffs and hard coastal barriers might be subject to significant increases wave-generated stresses under conditions of sea levels modestly higher than present.

The glass cliff: when and why women are selected as leaders in crisis contexts.

PubMed

Bruckmüller, Susanne; Branscombe, Nyla R

2010-09-01

The glass cliff refers to women being more likely to rise to positions of organizational leadership in times of crisis than in times of success, and men being more likely to achieve those positions in prosperous times. We examine the role that (a) a gendered history of leadership and (b) stereotypes about gender and leadership play in creating the glass cliff. In Expt 1, participants who read about a company with a male history of leadership selected a male future leader for a successful organization, but chose a female future leader in times of crisis. This interaction--between company performance and gender of the preferred future leader--was eliminated for a counter-stereotypic history of female leadership. In Expt 2, stereotypically male attributes were most predictive of leader selection in a successful organization, while stereotypically female attributes were most predictive in times of crisis. Differences in the endorsement of these stereotypes, in particular with regard to the ascription of lower stereotypically female attributes to the male candidate mediated the glass cliff effect. Overall, results suggest that stereotypes about male leadership may be more important for the glass cliff effect than stereotypes about women and leadership.

Methods for excluding cliff swallows from nesting on highway structures.

DOT National Transportation Integrated Search

2009-08-01

Cliff swallows (Petrochelidon pyrrhonota) are colonially breeding migratory birds that frequently nest on highway : structures. Protected by the Migratory Bird Treaty Act of 1918, nesting control methods cannot harm swallows or active : nests. This c...

At Base of 'Burns Cliff'

NASA Image and Video Library

2004-11-11

NASA's Mars Exploration Rover Opportunity captured this view from the base of "Burns Cliff" during the rover's 280th martian day (Nov. 6, 2004). This cliff in the inner wall of "Endurance Crater" displays multiple layers of bedrock for the rover to examine with its panoramic camera and miniature thermal emission spectrometer. The rover team has decided that the farthest Opportunity can safely advance along the base of the cliff is close to the squarish white rock near the center of this image. After examining the site for a few days from that position, the the rover will turn around and head out of the crater. The view is a mosaic of frames taken by Opportunity's navigation camera. The rover was on ground with a slope of about 30 degrees when the pictures were taken, and the view is presented here in a way that corrects for that tilt of the camera. http://photojournal.jpl.nasa.gov/catalog/PIA07039

Reply to comment on: Lawrence, J.A., Mortimore, R.N., Stone, K.J., and Busby, J.P., 2013. Sea saltwater weakening of chalk and the impact on cliff instability. Geomorphology 191, 14-22

NASA Astrophysics Data System (ADS)

Lawrence, James A.; Mortimore, Rory N.

2015-02-01

We are grateful to Dornbusch (2014) for the opportunity to clarify the role we propose for salt water weakening of the chalk and its potential importance as a mechanism contributing to cliff instability. Dornbusch's argument is based largely on a single comment "This work challenges the established view by identifying the role of salt from seawater in the degradation of porous rocks in coastal environments as a third and potentially the most important mechanism leading to chalk cliff collapse" (Lawrence et al., 2013: 15). This was not intended as a "conclusion" as suggested by Dornbusch (2014) but is rather a qualitative introductory statement highlighting the potential importance of the salt water weakening process in coastal cliff instability. The actual conclusions of the work are not challenged by Dornbusch (2014).

Seismic precursory patterns before a cliff collapse and critical point phenomena

USGS Publications Warehouse

Amitrano, D.; Grasso, J.-R.; Senfaute, G.

2005-01-01

We analyse the statistical pattern of seismicity before a 1-2 103 m3 chalk cliff collapse on the Normandie ocean shore, Western France. We show that a power law acceleration of seismicity rate and energy in both 40 Hz-1.5 kHz and 2 Hz-10kHz frequency range, is defined on 3 orders of magnitude, within 2 hours from the collapse time. Simultaneously, the average size of the seismic events increases toward the time to failure. These in situ results are derived from the only station located within one rupture length distance from the rock fall rupture plane. They mimic the "critical point" like behavior recovered from physical and numerical experiments before brittle failures and tertiary creep failures. Our analysis of this first seismic monitoring data of a cliff collapse suggests that the thermodynamic phase transition models for failure may apply for cliff collapse. Copyright 2005 by the American Geophysical Union.

Desert varnish (Permeon) evaluation : final report.

DOT National Transportation Integrated Search

2001-08-01

In 1997, the Oregon Department of Transportation mitigated a rock fall hazard on the historic Columbia River Highway. Loose rock was removed from the overhanging cliff while the sandstone near the base of the cliff was covered with shotcrete to preve...

Desert varnish Dabney state park

DOT National Transportation Integrated Search

2000-04-01

In 1997, ODOT mitigated a rock fall hazard on the Historic Columbia River Highway. Loose rock was removed from the overhanging cliff while the sandstone near the base of the cliff was covered with shotcrete to prevent erosion. The shotcrete was then ...

Burns Cliff in Color Stereo

NASA Image and Video Library

2006-07-10

NASA Mars Exploration Rover Opportunity captured a sweeping stereo image of Burns Cliff after driving right to the base of this southeastern portion of the inner wall of Endurance Crater in November 2004. 3D glasses are necessary to view this image.

Means of Slope Retreat on the Na Pali Cliffs, Kauai, Hawaii

NASA Astrophysics Data System (ADS)

Osborn, G.; Sheardown, A.; Blay, C.

2016-12-01

The spectacular, 500 to 600 m high, deeply grooved escarpment referred to as the Na Pali cliffs, on the northwest coast of Kauai, requires a substrate competent enough to hold up high steep cliffs yet erodible enough to allow generation of wide, deep grooves. These opposing tendencies are afforded by weathering of originally strong basalt that keeps pace with erosion. The fluted cliffs maintain a rather consistent slope angle, generally 50-60°, whether they are close to the shoreline or have retreated some distance from it, indicating that the slopes are retreating parallel to themselves. Previous literature promotes groundwater sapping or waterfall-plunge-pool erosion as the chief means of valley-head retreat, but there is no evidence that either concept provides a general explanation for retreat of the fluted cliffs. The eroding cliffs maintain steepness because as much rock is eroded at the base as at the top, and transported sediment is washed completely out of the gully system. The thin-bedded basalts exposed in the steep flutes are decomposed into irregularly alternating fine sediment of low to moderate cohesion and thoroughly fractured beds or lenses of solid but chemically weathered rock, and covered with a veneer of sparse grass. Erosion proceeds by episodic removal of thin grass-covered surficial sheets of the weathering products. Some of this process may be facilitated by shallow mass movement, but probably most of the work is done by overland and channelized flow during intense rainstorms. The Na Pali coast experiences one-hour rainfalls of 2-2.5 inches (1 year recurrence interval) and 5-6 inches (100 year recurrence interval); experiments by others on basaltic soils in Molokai suggest such rain is more than enough to generate erosion-inducing overland flow. Between the deep grooves and the shoreline are slopes with lesser drainage densities and lesser slope angles. The rocks here are not distinguished from the rocks above in previous literature, and there is no reason to expect any difference in lithology. The lower-angle slopes may be erosional footslopes, genetically similar to desert pediments, left behind as the fluted cliffs retreat. On their uphill edges the lower-angle slopes are expanding in area as the cliffs retreat but at the coast the slopes are being consumed by wave action.

Multi-temporal Terrestrial Laser Scanner monitoring of coastal instability processes at Coroglio cliff

NASA Astrophysics Data System (ADS)

Caputo, Teresa; Somma, Renato; Marino, Ermanno; Matano, Fabio; Troise, Claudia; De Natale, Giuseppe

2016-04-01

The Coroglio cliff is a morphological evolution of the caldera rim of Neapolitan Yellow Tuff (NYT) in Campi Flegrei caldera (CFc) with an elevation of 150 m a.s.l. and a length of about 200 m. The lithology consists of NYT, extremely lithified, overlaid by less lithified recent products of the Phlegrean volcanism., These materials are highly erodible and, due to proximity to the sea, the sea wave and wind actions cause very strong erosion process. In the recent years Terrestrial Laser Scanner (TLS) technique is used for environmental monitoring purposes through the creation of high resolution Digital Surface Model (DSM) and Digital Terrain Model (DTM). This method allows the reconstruction, by means of a dense cloud of points, of a 3D model for the entire investigated area. The scans need to be performed from different points of view in order to ensure a good coverage of the area, because a widespread problem is the occurrence of shaded areas. In our study we used a long-range laser scanner model RIEGL VZ1000®. Numerous surveys (April 2013, June 2014, February 2015) have been performed for monitoring coastal cliff morphological evolution. An additional survey was executed in March 2015, shortly after a landslide occurrence. To validate the multi-temporal monitoring of the laser scanner, a "quick" comparison of the acquired point clouds has been carried out using an algorithm cloud-to-cloud, in order to identify 3D changes. Then 2.5D raster images of the different scans has been performed in GIS environment, also in order to allow a map overlay of the produced thematic layer, both raster and vector data (geology, contour map, orthophoto, and so on). The comparison of multi-temporal data have evidenced interesting geomorphological processes on the cliff. It was observed a very intense (about 6 m) local moving back at the base of the cliff, mainly due to the sea wave action during storms, while in cliff sectors characterized by less compact lithologies widespread small (> 50 cm wide) erosion forms have been recognized. Finally, the upper part of the cliff, characterized by loose pyroclastic deposits covered by vegetation, resulted affected by small collapses, which can involve the public gardens of Virgiliano Park, located at the top of the cliff.

Cliff Collapse Hazard from Repeated Multicopter Uav Acquisitions: Return on Experience

NASA Astrophysics Data System (ADS)

Dewez, T. J. B.; Leroux, J.; Morelli, S.

2016-06-01

Cliff collapse poses a serious hazard to infrastructure and passers-by. Obtaining information such as magnitude-frequency relationship for a specific site is of great help to adapt appropriate mitigation measures. While it is possible to monitor hundreds-of-meter-long cliff sites with ground based techniques (e.g. lidar or photogrammetry), it is both time consuming and scientifically limiting to focus on short cliff sections. In the project SUAVE, we sought to investigate whether an octocopter UAV photogrammetric survey would perform sufficiently well in order to repeatedly survey cliff face geometry and derive rock fall inventories amenable to probabilistic rock fall hazard computation. An experiment was therefore run on a well-studied site of the chalk coast of Normandy, in Mesnil Val, along the English Channel (Northern France). Two campaigns were organized in January and June 2015 which surveyed about 60 ha of coastline, including the 80-m-high cliff face, the chalk platform at its foot, and the hinterland in a matter of 4 hours from start to finish. To conform with UAV regulations, the flight was flown in 3 legs for a total of about 30 minutes in the air. A total of 868 and 1106 photos were respectively shot with a Sony NEX 7 with fixed focal 16mm. Three lines of sight were combined: horizontal shots for cliff face imaging, 45°-oblique views to tie plateau/platform photos with cliff face images, and regular vertical shots. Photogrammetrically derived dense point clouds were produced with Agisoft Photoscan at ultra-high density (median density is 1 point every 1.7cm). Point cloud density proved a critical parameter to reproduce faithfully the chalk face's geometry. Tuning down the density parameter to "high" or "medium", though efficient from a computational point of view, generated artefacts along chalk bed edges (i.e. smoothing the sharp gradient) and ultimately creating ghost volumes when computing cloud to cloud differences. Yet, from a hazard point of view, this is where small rock fall will most likely occur. Absolute orientation of both point clouds proved unsufficient despite the 30 black and white quadrants ground control point DGPS surveyed. Additional ICP was necessary to reach centimeter-level accuracy and segment rock fall scars corresponding to the expected average daily rock fall volume (ca. 0.013 m3).

77 FR 47121 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Units 1 and 2...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-07

... for Nuclear Power Plant Personnel,'' endorses the Nuclear Energy Institute (NEI) report NEI 06-11...(c)(25). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment...

Ice-Cliff Failure via Retrogressive Slumping

NASA Astrophysics Data System (ADS)

Parizek, B. R.; Christianson, K.; Alley, R. B.; Voytenko, D.; Vankova, I.; Dixon, T. H.; Holland, D.

2016-12-01

The magnitude and rate of future sea-level rise from warming-induced ice-sheet shrinkage remain notably uncertain. Removal of most of an ice sheet by surface melting alone requires centuries to millennia. Oceanic warming may accelerate loss by removing buttressing ice shelves and thereby speeding flow of non-floating ice into the ocean, but, until recently, modeled timescales for major dynamic ice-sheet shrinkage were centuries or longer. Beyond certain thresholds, however, observations show that warming removes floating ice shelves, leaving grounded ice cliffs from which icebergs break off directly. Cliffs higher than some limit experience rapid structural failure. Recent parameterization of this process in a comprehensive ice-flow model produced much faster sea-level rise from future rapid warming than in previous modeling studies, through formation and retreat of tall ice cliffs. Fully physical representations of this process are not yet available, however. Here, we use modeling guided by terrestrial radar data from Helheim Glacier, Greenland to show that cliffs will fail by slumping and trigger rapid retreat at a threshold height that, in crevassed ice with surface melting, may be only slightly above the 100-m maximum observed today, but may be roughly twice that (180-275 m) in mechanically-competent ice under well-drained or low-melt conditions.

Update on Simulating Ice-Cliff Failure

NASA Astrophysics Data System (ADS)

Parizek, B. R.; Christianson, K. A.; Alley, R. B.; Voytenko, D.; Vankova, I.; Dixon, T. H.; Walker, R. T.; Holland, D.

2017-12-01

Using a 2D full-Stokes diagnostic ice-flow model and engineering and glaciological failure criteria, we simulate the limiting physical conditions for rapid structural failure of subaerial ice cliffs. Previously, using a higher-order flowline model, we reported that the threshold height, in crevassed ice and/or under favorable conditions for hydrofracture or crack lubrication, may be only slightly above the 100-m maximum observed today and that under well-drained or low-melt conditions, mechanically-competent ice supports cliff heights up to 220 m (with a likely range of 180-275 m) before ultimately succumbing to tensional and compressive failure along a listric surface. However, proximal to calving fronts, bridging effects lead to variations in vertical normal stress from the background glaciostatic stress state that give rise to the along-flow gradients in vertical shear stress that are included within a full-Stokes momentum balance. When including all flowline stresses within the physics core, diagnostic solutions continue to support our earlier findings that slumping failure ultimately limits the upper bound for cliff heights. Shear failure still requires low cohesive strength, tensile failure leads to deeper dry-crevasse propagation (albeit, less than halfway through the cliff), and compressive failure drops the threshold height for triggering rapid ice-front retreat via slumping to 200 m (145-280 m).

Inshore analyse of the morphostructural evolution of the coastal cliffs of Bessin, Basse-Normandie, France

NASA Astrophysics Data System (ADS)

Vioget, Alizée; Costa, Stéphane; Derron, Marc-Henri; Jaboyedoff, Michel; Maquaire, Olivier; Michoud, Clément

2014-05-01

The cliffs' retreat is a major issue for the management of coastal territories. Two coastal areas in "Calvados" and "Pays de Caux", French Normandy, are studied by the University of Caen for several years, and more recently assisted by the University of Lausanne. The studied section of the cliffs of Bessin is about 4.3 km long and lies between the World War II artillery batteries of Longues-sur-Mer and Arromanches-les-Bains. The site's lithology is mainly made of two formations: the limestones of Bessin that lie on top of the marls of Port. On the coastline, the cliff's height varies between 10 and 75 meters above sea level. The marl formation acts like an aquitard, as it is semi-impermeable. Therefore, more or less important water outflows are observable at the point of contact between the marls and the limestones. First, the study aims to create an up to date geomorphological map as well as a kinematic classification of the existing instabilities of the different cliff's profiles. This part is realized with on site field measurements. We observe several profiles depending on the type of cliff studied: sinking of limestone panels due to creeping marls at the base, overhang limestone formation, wave-cut notch, detachment, tilt, rotational slide, superficial separation etc. These several behaviours depend on the cliff's exposure to the Channel sea and weathering factors, morphology, presence of pebble beach etc. The coastline section is thus classified depending on the different morphological types observed, which influence the stability and erosion rates. Principal morphological types here are: overhang limestone formation near Cape Manvieux, creeping marls near le Chaos and graben near le Bouffay. Then, the cliffs' condition is compared to the diachronic analyse of the shoreline evolution supported by different photographic documents. This part of the study allows to refine the spatiotemporal occurrence of the different ground movements. However, cliffs'retreat evolves in successive leaps and bounds. Thus, results won't be significant if there aren't long period observations. Therefore, the documents used consist of orthophotos and oblique aerial pictures that cover a period from 1947 to 2009. This step shows higher retreat velocity in marls (0.15-0.2 m/yr) substratum than in limestones (0.05-0.1 m/yr). Finally, we also focused on a complex landslide that happened in May 2013 near Cape Manvieux. We aim to reconstruct the kinematic and to determine the mass volume that has moved. For that purpose, a terrestrial LiDAR (Optech Ilris-3D ER) acquisition of the instability was performed in July 2013. The 3D point cloud allows a quite precise estimation of involved volume. Moreover, LiDAR data and field observations let us think that the current state of the instability was created by multiple events and is a complex mix of creeping marls and toppling of limestone destabilised by a back subvertical discontinuity which is parallel to the coastline. In conclusion, the studies on morphostructural evolution of the cliffs with geomorphological field studies and LiDAR acquisition lead to a better comprehension of coastline retreat in Normandy.

Cliff top habitats provide important alternative feeding resources for wading birds of conservation importance wintering on non-estuarine coasts

NASA Astrophysics Data System (ADS)

Furnell, Julie; Hull, Susan L.

2014-02-01

Rocky shores and beaches are important over-wintering areas for non-estuarine waders but have rarely been studied. We examined cliff top habitat use by 6 species of wader over 75 km of coast to assess their potential value as alternative feeding sites to rocky and sandy shores. Both the regional and local survey showed that waders occurred on golf courses and recreational grasslands in higher frequencies than expected but arable and pasture use was lower than expected. We also compared local wader densities on rocky and sandy shores, pastures, golf courses, caravan parks and recreational grasslands over two winters. Sanderling predominantly fed on the beach whereas Oystercatcher, Dunlin, Turnstone and Redshank numbers significantly increased on golf courses and recreational grasslands over the winter period, with pasture being rarely used. General linear models were used to relate environmental factors to the presence and absence of each species on the cliff top habitats. Redshank was the only species that showed a higher probability of occurrence on cliff top habitats at high tide whereas the probability of Turnstone, Oystercatcher and Redshank occurring increased as temperatures declined. Using core sampling, we determined that invertebrate richness and abundance was significantly higher on the recreational grasslands and golf courses than on the pasture or the beach. Our data demonstrated that cliff top habitats are important alternative feeding areas for over-wintering waders in areas where the intertidal is bounded by cliffs. Current management creates short sward, open field habitats with a diverse and abundant invertebrate food supply exploited by waders. Any alterations to the land use of these areas should be carefully considered by planning authorities in light of the fact that they support species that are of conservation concern.

75 FR 12533 - Combined Notice Of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-16

....; R.E. Ginna Nuclear Power Plant, LLC; Constellation Energy Commodities Group; Constellation Energy Commodities Group Maine; Raven Three, LLC; Raven Two, LLC; Raven One, LLC; Calvert Cliffs Nuclear Power Plant LLC. Description: Calvert Cliffs Nuclear Power Plant submits Substitute First Revised Sheet 1 et al...

Climate change-driven cliff and beach evolution at decadal to centennial time scales

USGS Publications Warehouse

Erikson, Li; O'Neill, Andrea; Barnard, Patrick; Vitousek, Sean; Limber, Patrick

2017-01-01

Here we develop a computationally efficient method that evolves cross-shore profiles of sand beaches with or without cliffs along natural and urban coastal environments and across expansive geographic areas at decadal to centennial time-scales driven by 21st century climate change projections. The model requires projected sea level rise rates, extrema of nearshore wave conditions, bluff recession and shoreline change rates, and cross-shore profiles representing present-day conditions. The model is applied to the ~470-km long coast of the Southern California Bight, USA, using recently available projected nearshore waves and bluff recession and shoreline change rates. The results indicate that eroded cliff material, from unarmored cliffs, contribute 11% to 26% to the total sediment budget. Historical beach nourishment rates will need to increase by more than 30% for a 0.25 m sea level rise (~2044) and by at least 75% by the year 2100 for a 1 m sea level rise, if evolution of the shoreline is to keep pace with rising sea levels.

Exploring the cliff retreat response to base level change using SFM photogrammetry and cosmogenic 36Cl, Coal Cliffs, Utah, USA

NASA Astrophysics Data System (ADS)

Sheehan, C.; Ward, D.

2015-12-01

The retreat of cliffbands is an important erosional process within the relatively undeformed sedimentary layers of the Colorado Plateau. Many iconic cliff landforms, including those of Monument Valley and Grand Canyon, are maintained by the interaction of these different rock types. A several kilometer thickness of incised sandstone and shale formations allow this region to act as a natural laboratory for studying the effects of variable lithologies on landscape evolution. Cliffband morphology and retreat on the plateau are controlled by several factors that may vary over time and space, including lithology, rate and distribution of rockfall debris, bedrock structure, baselevel, and climate. The relative importance of each factor in setting rates of cliff retreat are not entirely clear. Because regional headwaters are commonly sourced at cliff bases, these landforms are often the final and slowest areas to respond to baselevel changes, allowing rockfall and other local stochastic processes to overwhelm the erosional response to a baselevel forcing. The roles of these processes are difficult to assess because very few measurements of retreat rates over geomorphic timescales (103-106 years) have been produced, and thus changes in cliffband position through time have only been constrained by inferences made from the regional erosional history. Here, we control for climate and rock type by focusing on a continuous, 40-kilometer section of the lithologically consistent Coal Cliffs in Emery County, Utah. This area presents several natural experiments illustrating cliffband response to different forcings, including relict surfaces reflecting a baselevel change, drainage divides across which the adjustment to base level change may be asynchronous, a zone wherein the caprock layer has been removed by backscarp erosion, and a generally continuous gradient in cliff height from 50 to >200 meters along the cliffline. We employ terrestrial Cl36 exposure dating on terraces, talus flatirons, and perched boulders to constrain the rate of cliffband movement over the most recent period of retreat. Field mapping, relative weathering measurements, and high-resolution DEMs created from structure-from-motion (SFM) photogrammetry are used to evaluate the morphological response in each case.

Holocene Evolution of Incised Coastal Channels on the Isle of Wight, UK: Interpretation via Numerical Simulation.

NASA Astrophysics Data System (ADS)

Leyland, J.; Darby, S. E.

2006-12-01

Incised coastal channels are found in numerous locations around the world where the shoreline morphology consists of cliffs. The incised coastal channels found on the Isle of Wight, UK, are known locally as `Chines' and debouche (up to 45m) through the soft cliffs of the south west coast, maintaining steep side walls subject to deep-seated mass wasting. These canyons offer sheltered locations and bare substrate, providing habitat for plant (Philonotis marchica, Anthoceros punctatos) and invertebrate (Psen atratinus, Baris analis, Melitaea cinxi) species of international importance. The base level of the Chines is highly dynamic, with episodes of sea cliff erosion causing the rejuvenation of the channel network. Consequently a key factor in Chine evolution is the relative balance between rates of cliff retreat and headwards incision caused by knickpoint migration. Specifically, there is concern that if contemporary coastal retreat rates are higher than the corresponding rates of knickpoint recession, there will be long-term a reduction in the overall extent of the Chines and their associated habitats. In an attempt to provide a long-term context for these issues, in this poster we explore the Holocene erosional history of the Chines using a numerical landscape evolution model. The model includes a stochastic cliff recession function that controls the position of the outlet boundary. Knickpoint recession rates are simulated using a detachment-limited channel erosion law wherein erosion rate is a power function of drainage area and stream gradient with model parameters defined using empirically- derived data. Simulations are undertaken for a range of imposed boundary conditions representing different scenarios of long-term cliff retreat forced by Holocene sea-level rise, plausible scenarios corresponding to cases where simulated and observed Chine and landscape forms match. The study provides an example of how a landscape evolution model could be used to reconstruct Holocene coastal processes, as well as providing the long-term context necessary to manage Chine habitats appropriately. In particular a critical threshold drainage area is defined that provides knickpoint recession rates that are sufficient to generate self- sustaining Chines in relation to cliff recession rates.

A theropod dinosaur embryo and the affinities of the flaming cliffs dinosaur eggs.

PubMed

Norell, M A; Clark, J M; Demberelyin, D; Rhinchen, B; Chiappe, L M; Davidson, A R; McKenna, M C; Altangerel, P; Novacek, M J

1994-11-04

An embryonic skeleton of a nonavian theropod dinosaur was found preserved in an egg from Upper Cretaceous rocks in the Gobi Desert of Mongolia. Cranial features identify the embryo as a member of Oviraptoridae. Two embryo-sized skulls of dromaeosaurids, similar to that of Velociraptor, were also recovered in the nest. The eggshell microstructure is similar to that of ratite birds and is of a type common in the Djadokhta Formation at the Flaming Cliffs (Bayn Dzak). Discovery of a nest of such eggs at the Flaming Cliffs in 1923, beneath the Oviraptor philoceratops holotype, suggests that this dinosaur may have been a brooding adult.

Networks - The Air Force’s Newest Weapon Systems

DTIC Science & Technology

2006-02-17

Force networks. Marshall T. Rose, The Simple Book: An Introduction to Management of TCP/IP based internets, (Englewood Cliffs, New Jersey: Prentice...18 November 2005 19. Rose, Marshall T. The Simple Book: An Introduction to Management of TCP/IP based internets, (Englewood Cliffs, New Jersey

Study of cliff activity dominating the gas and dust comae of comet 67P/Churyumov-Gerasimenko during the early phase of the Rosetta mission using ROSINA/COPS and OSIRIS data

NASA Astrophysics Data System (ADS)

Marschall, Raphael; Su, Cheng-Chin; Liao, Ying; Rubin, Martin; Wu, Jong-Shinn; Thomas, Nicolas; altwegg, kathrin; Sierks, Holger; OSIRIS, ROSINA

2016-10-01

The study by [1] has proposed the idea that the cometary dust jets in the northern hemisphere of comet 67P/Churyumov-Gerasimenko arise mainly from rough cliff like terrain. Using our 3D gas and dust dynamics coma model [2] we have run simulations targeting the question whether areas with high gravitational slopes alone can indeed account for both the ROSINA/COPS and the OSIRIS data obtained for mid August to end October 2014.The basis of our simulations is the shape model "SHAP4S" of [3]. Surface temperatures have been defined using a simple 1-D thermal model (including insolation, shadowing, thermal emission, sublimation but neglecting conduction) computed for each facet of the shape model allowing a consistent and known description of the gas flux and its initial temperature. In a next step we use the DSMC program PDSC++ [4] to calculate the gas properties in 3D space. The gas solution can be compared with the in situ measurements by ROSINA/COPS. In a subsequent step dust particles are introduced into the gas flow to determine dust densities and with a column integrator and Mie theory dust brightnesses that can be compared to OSIRIS data.To examine cliff activity we have divided the surface into two sets. One with gravitational slopes larger than 30° which we call cliffs and one with slopes less than 30° which we shall call plains. We have set up two models, "cliff only" and "plains only" where the respective set of areas are active and the others inert. The outgassing areas are assumed to be purely insolation driven. The "cliffs only" model is a statistically equally good fit to the ROSINA/COPS data as the global insolation driven model presented in [2]. The "plains only" model on the other hand is statistically inferior to the "cliffs only" model. We found in [2] that increased activity in the Hapi region (called inhomogeneous model) of the comet improves the fit of the gas results significantly. We can show in this study that a "cliffs + Hapi" model fits the ROSINA/COPS data equally well as the inhomogeneous model. These results are consistent with OSIRIS data.[1] Vincent et al., 2016, A&A, 587, A14[2] Marschall et al., 2016; A&A, 589, A90[3] Preusker et al., 2015, A&A 583, A33[4] Su, C. C., 2013

Terrestrial Laser Scanner for assessing rockfall susceptibility in the Cilento rocky coast (Southern Italy)

NASA Astrophysics Data System (ADS)

Sorrentino, Valerio; Matasci, Battista; Abellan, Antonio; Jaboyedoff, Michel; Marino, Ermanno; Pignalosa, Antonio; Santo, Antonio

2016-04-01

Rockfalls and other types of landslides are the dominant processes causing a retreat of sea cliffs. The coastal areas constitute an important tourist attraction and a large number of people rest beneath the cliffs on a daily basis, considerably increasing the risk associated to rockfalls. We present an approach to assess rockfall susceptibility at the cliff scale based on terrestrial laser scanner (TLS) point clouds. The test area is a coastal cliff situated in the southern part of the Cilento (Centola Municipality, Campania Region), in which a natural arch was formed. This cliff is constituted by heavy fractured carbonate rock mass with a strong structural control. In June 2015 TLS data were acquired with long-range scanner RIEGL VZ1000®. The structural analysis of the cliff was performed in the field and using Coltop 3D software on the point cloud. As a result, 10 discontinuity sets (joint, faults and bedding planes) were individuated and the different characteristics such as orientation, spacing and persistence were measured. The kinematically unstable areas were highlighted using a script that computes an index of susceptibility to rockfalls based on the spatial distribution of failure mechanisms. The susceptibility index computation is based on the average surface that every joint set (or combinations of two joint sets in the case of wedge failure) forms on the topography according to its spacing, trace length, and incidence angle. This susceptibility index also depends on the steepness of the joint set (or of the intersection line in the case of wedge failure). As a result the most important discontinuity sets in terms of potential planar failure, wedge failure and toppling were individuated and an assessment of rockfall susceptibility at the cliff scale was achieved. Results show that the kinematically feasible failures are not equally distributed along the cliff but concentrated on certain areas. The most susceptible areas for planar failure are related to the discontinuity set K10 (71/097), whereas for toppling the highest susceptibility is reached with K1 (60/218). Concerning wedge failure, the combination of K10 and K1 yields the highest susceptibility values. It shows also clustering with higher density which is probably related to regional structures. More detailed investigations of the rockfall susceptibility and failure mechanisms will be performed during the forthcoming months. The relationship with regional structures will be also investigated in more detail. Perspectives also include using the methodology on the other side of the natural arch in order to provide a global susceptibility assessment of the area.

Calculation of the rockwall recession rate of a limestone cliff, affected by rockfalls, using cosmogenic chlorine-36. Case study of the Montsec Range (Eastern Pyrenees, Spain)

NASA Astrophysics Data System (ADS)

Domènech, Guillem; Corominas, Jordi; Mavrouli, Olga; Merchel, Silke; Abellán, Antonio; Pavetich, Stefan; Rugel, Georg

2018-04-01

Cliff erosion may be a major problem in settled areas affecting populations and producing economic and ecological losses. In this paper we present a procedure to calculate the long-term retreat rate of a cliff affected by rockfalls in the Montsec Range, Eastern Pyrenees (Spain). It is composed of low, densely fractured limestones; and the rockwall is affected by rockfalls of different sizes. The rockfall scars are clearly distinguishable by their regular boundaries and by their orange colour, which contrast with the greyish old reference surface (S0) of the cliff face. We have dated different stepped surfaces of the rockwall, including S0, using cosmogenic 36Cl. The total amount of material released by rockfall activity was calculated using a high definition point cloud of the slope face obtained with a terrestrial laser scanner (TLS). The present rockwall surface has been subtracted from the reconstructed old cliff surface. This has allowed the calculation of the total volume released by rockfalls and of the retreat rate. The latter ranges from 0.31 to 0.37 mm·a- 1. This value is of the same order of magnitude as that obtained by other researchers in neighbouring regions in Spain, having similar geology and affected by rockfalls.

77 FR 11165 - Order Approving Application Regarding Proposed Corporate Merger and Indirect Transfer of Licenses

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

.... CONSTELLATION ENERGY GROUP, INC. CALVERT CLIFFS NUCLEAR POWER PLANT, LLC. Calvert Cliffs Nuclear Power Plant... Corporation (Exelon), and Exelon Ventures Company, LLC (Exelon Ventures), and Constellation Energy Nuclear... Energy Nuclear Group, LLC, shall prepare an Annual Report regarding the status of foreign ownership...

77 FR 69449 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-19

.... Applicants: Calvert Cliffs Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, R.E. Ginna Nuclear Power Plant, LLC. Description: Notice of Non-Material Change in Status of Calvert Cliffs Nuclear Power...., Constellation Power Source Generation, Inc., Cow Branch Wind Power, L.L.C., CR Clearing, LLC, Criterion Power...

Geologic map of the Gila Hot Springs 7.5' quadrangle and the Cliff Dwellings National Monument, Catron and Grant Counties, New Mexico

USGS Publications Warehouse

Ratté, James C.; Gaskill, David L.; Chappell, James R.

2014-01-01

The Gila Hot Springs quadrangle is of geologic interest with respect to four major features, which are: 1)\tThe caves of the Gila Cliff Dwellings National Monument 2)\tThe hot springs associated with the faults of the Gila Hot Springs graben 3)\tThe Alum Mountain rhyolite dome and eruptive center 4)\tA proposed segment of the southeastern wall of the Gila Cliff Dwellings caldera The Gila Cliff Dwellings National Monument consists of two tracts. The caves that were inhabited by the Mogollon people in the 14th century are in the main tract near the mouth of Cliff Dweller Canyon in the Little Turkey Park 7.5' quadrangle adjoining the northwest corner of the Gila Hot Springs quadrangle. The second tract includes the Cliff Dwellings National Monument Visitor Center at the confluence of the West and Middle Forks of the Gila River in the northwest corner of the Gila Hot Springs quadrangle. Both quadrangles are within the Gila National Forest and the Gila Wilderness except for a narrow corridor that provides access to the National Monument and the small ranching and residential community at Gila Center in the Gila River valley. The caves in Cliff Dweller Canyon were developed in the Gila Conglomerate of probable Miocene? and Pleistocene? age in this area by processes of lateral corrosion and spring sapping along the creek in Cliff Dweller Canyon. The hot springs in the Gila River valley are localized along faults in the deepest part of the Gila Hot Springs graben, which cuts diagonally northwest-southeast across the central part of the quadrangle. Some of the springs provide domestic hot water for space heating and agriculture in the Gila River valley and represent a possible thermal resource for development at the Cliff Dwellings National Monument. The Alum Mountain rhyolite dome and eruptive center in the southwestern part of the quadrangle is a colorful area of altered and mineralized rocks that is satellitic to the larger Copperas Canyon eruptive center, both being part of the composite Copperas Creek volcano, or volcanic complex in the Copperas Peak quadrangle to the south. The altered rocks of the Alum Mountain eruptive center have been prospected by means of several short adits, or tunnels, for alum, a mixture of the iron and aluminum sulfate minerals: alunite and halotrichite. A fault on the west side of the Gila River, opposite the hot springs in the south-central part of the map area, just north of Alum Mountain, is tentatively interpreted as a segment of the wall of the Gila Cliff Dwellings caldera. The fault, which dips about 55 degrees northwest, has a footwall of the andesitic and dacitic lava flows and flow breccias of Gila Flat. The hanging wall consists of Bloodgood Canyon Tuff overlain by Bearwallow Mountain Andesite flows. However, these rocks are not faulted against the older rocks, but apparently abut and locally overlap the footwall. These are the major geologic features of the quadrangle, about three quarters of which is covered by Bearwallow Mountain Andesite lava flows and overlying volcaniclastic rocks of the Gila Conglomerate.

Meet the 2008 Cliff Weiss Memorial Essay Contest Winners

ERIC Educational Resources Information Center

Techniques: Connecting Education and Careers (J3), 2008

2008-01-01

This article presents the winners of the 2008 Cliff Weiss Memorial Essay Contest and their winning essays. The winners are Spencer Terry of Tulsa, Oklahoma (secondary), and Carrie Snyder-Renfro of Oklahoma City, Oklahoma (postsecondary). The topic for secondary students is "How would you communicate the impact and importance of CTE related to your…

Avoidance of Heights on the Visual Cliff in Newly Walking Infants

ERIC Educational Resources Information Center

Witherington, David C.; Campos, Joseph J.; Anderson, David I.; Lejeune, Laure; Seah, Eileen

2005-01-01

Work with infants on the "visual cliff" links avoidance of drop-offs to experience with self-produced locomotion. Adolph's (2002) research on infants' perception of slope and gap traversability suggests that learning to avoid falling down is highly specific to the postural context in which it occurs. Infants, for example, who have…

Cliff or Step? Posture-Specific Learning at the Edge of a Drop-Off

ERIC Educational Resources Information Center

Kretch, Kari S.; Adolph, Karen E.

2013-01-01

Infants require locomotor experience to behave adaptively at a drop-off. However, different experimental paradigms (visual cliff and actual gaps and slopes) have generated conflicting findings regarding what infants learn and the specificity of their learning. An actual, adjustable drop-off apparatus was used to investigate whether learning to…

76 FR 53673 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-29

.... Ginna Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC. Description: Notice of Change in Status of Calvert Cliffs Nuclear Power Plant, LLC, et al. Filed....17(b): Amendment to 1765R4 KCPL-GMO NITSA NOA to be effective 6/1/ 2011. Filed Date: 08/19/2011...

78 FR 32013 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for 38 Species...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-28

... recently published paper, Koyama et al. (2010, pp. 29-30) found that based on spikelet and achene...) are found in 10 ecosystem types: Coastal, lowland dry, lowland mesic, lowland wet, montane dry, montane wet, montane mesic, subalpine, dry cliff, and wet cliff (Table 3). [[Page 32017

78 FR 64637 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for 15...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-29

..., and 1 picture-wing fly) are found in 10 ecosystem types: anchialine pool, coastal, lowland dry, lowland mesic, lowland wet, montane dry, montane mesic, montane wet, dry cliff, and wet cliff (Table 2.... hillebrandiana. Lowland Dry Bidens micrantha ssp. ctenophylla. Lowland Mesic Pittosporum hawaiiense...

78 FR 16492 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-15

...-2181-017; ER10-2182-017. Applicants: Calvert Cliffs Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, R.E. Ginna Nuclear Power Plant, LLC. Description: Notice of Non-Material Change in Status of Calvert Cliffs Nuclear Power Plant, LLC, et. al. Filed Date: 3/8/13. Accession Number: 20130308-5085...

78 FR 26348 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-06

...: Docket Numbers: ER10-2179-018; ER10-2181-018; ER10-2182-018. Applicants: R.E. Ginna Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, Calvert Cliffs Nuclear Power Plant, LLC. Description: Notice of Change in Status of Calvert Cliffs Nuclear Power Plant, LLC, et al. Filed Date: 4/26/13...

78 FR 49742 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-15

...-2181-019; ER10-2182-019. Applicants: Calvert Cliffs Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, R.E. Ginna Nuclear Power Plant, LLC. Description: Notice of Non-Material Change in Status of Calvert Cliffs Nuclear Power Plant, LLC, et al. Filed Date: 8/8/13. Accession Number: 20130808-5137...

Predation by ants controls swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) infestations.

PubMed

Brown, Charles R; Page, Catherine E; Robison, Grant A; O'Brien, Valerie A; Booth, Warren

2015-06-01

The swallow bug (Oeciacus vicarius) is the only known vector for Buggy Creek virus (BCRV), an alphavirus that circulates in cliff swallows (Petrochelidon pyrrhonota) and house sparrows (Passer domesticus) in North America. We discovered ants (Crematogaster lineolata and Formica spp.) preying on swallow bugs at cliff swallow colonies in western Nebraska, U.S.A. Ants reduced the numbers of visible bugs on active swallow nests by 74-90%, relative to nests in the same colony without ants. Ant predation on bugs had no effect on the reproductive success of cliff swallows inhabiting the nests where ants foraged. Ants represent an effective and presumably benign way of controlling swallow bugs at nests in some colonies. They may constitute an alternative to insecticide use at sites where ecologists wish to remove the effects of swallow bugs on cliff swallows or house sparrows. By reducing bug numbers, ant presence may also lessen BCRV transmission at the spatial foci (bird colony sites) where epizootics occur. The effect of ants on swallow bugs should be accounted for in studying variation among sites in vector abundance. © 2015 The Society for Vector Ecology.

FIB preparation of a NiO Wedge-Lamella and STEM X-ray microanalysis for the determination of the experimental k(O-Ni) Cliff-Lorimer coefficient.

PubMed

Armigliato, Aldo; Frabboni, Stefano; Gazzadi, Gian Carlo; Rosa, Rodolfo

2013-02-01

A method for the fabrication of a wedge-shaped thin NiO lamella by focused ion beam is reported. The starting sample is an oxidized bulk single crystalline, <100> oriented, Ni commercial standard. The lamella is employed for the determination, by analytical electron microscopy at 200 kV of the experimental k(O-Ni) Cliff-Lorimer (G. Cliff & G.W. Lorimer, J Microsc 103, 203-207, 1975) coefficient, according to the extrapolation method by Van Cappellen (E. Van Cappellen, Microsc Microstruct Microanal 1, 1-22, 1990). The result thus obtained is compared to the theoretical k(O-Ni) values either implemented into the commercial software for X-ray microanalysis quantification of the scanning transmission electron microscopy/energy dispersive spectrometry equipment or calculated by the Monte Carlo method. Significant differences among the three values are found. This confirms that for a reliable quantification of binary alloys containing light elements, the choice of the Cliff-Lorimer coefficients is crucial and experimental values are recommended.

The effect of weather on morphometric traits of juvenile cliff swallows

USGS Publications Warehouse

Roche, Erin A.; Brown, Mary Bomberger; Brown, Charles R.

2015-01-01

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regularly experience brief periods of severe weather-induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally smaller in cooler years. However, variability explained by weather was small, suggesting that morphometric traits of juvenile cliff swallows were not highly sensitive to weather conditions experienced during this study. Measurements of juvenile morphological traits were positively correlated with measurements taken as adults, meaning that any variation among juveniles in response to rearing conditions showed evidence of persisting into a bird’s first breeding season. Our results show that body size in this species is phenotypically plastic and influenced, in part, by weather variables.

Stability analysis of chalk sea cliffs using UAV photogrammetry

NASA Astrophysics Data System (ADS)

Barlow, John; Gilham, Jamie

2017-04-01

Cliff erosion and instability poses a significant hazard to communities and infrastructure located is coastal areas. We use point cloud and spectral data derived from close range digital photogrammetry to assess the stability of chalk sea cliffs located at Telscombe, UK. Data captured from an unmanned aerial vehicle (UAV) were used to generate dense point clouds for a 712 m section of cliff face which ranges from 20 to 49 m in height. Generated models fitted our ground control network within a standard error of 0.03 m. Structural features such as joints, bedding planes, and faults were manually mapped and are consistent with results from other studies that have been conducted using direct measurement in the field. Kinematic analysis of these data was used to identify the primary modes of failure at the site. Our results indicate that wedge failure is by far the most likely mode of slope instability. An analysis of sequential surveys taken from the summer of 2016 to the winter of 2017 indicate several large failures have occurred at the site. We establish the volume of failure through change detection between sequential data sets and use back analysis to determine the strength of shear surfaces for each failure. Our results show that data capture through UAV photogrammetry can provide useful information for slope stability analysis over long sections of cliff. The use of this technology offers significant benefits in equipment costs and field time over existing methods.

Three-dimensional resistivity tomography in extreme coastal terrain amidst dense cultural signals: application to cliff stability assessment at the historic D-Day site

NASA Astrophysics Data System (ADS)

Udphuay, Suwimon; Günther, Thomas; Everett, Mark E.; Warden, Robert R.; Briaud, Jean-Louis

2011-04-01

Pointe du Hoc overlooking the English Channel in Normandy, France was host to one of the most important military engagements of World War II but is vulnerable to cliff collapses that threaten important German fortifications including the forward observation post (OP) and Rudder's command post. The objective of this study is to apply advanced 3-D resistivity tomography towards a detailed site stability assessment with special attention to the two at-risk buildings. 3-D resistivity tomography data sets at Pointe du Hoc in the presence of extreme topography and dense cultural clutter have been successfully acquired, inverted and interpreted. A cliff stability hazard assessment scheme has been designed in which regions of high resistivity are interpreted as zones of open, dry fractures with a moderate mass movement potential. Regions of low resistivity are zones of wet, clay-filled fractures with a high mass movement potential. The OP tomography results indicate that the highest mass movement hazard appears to be associated with the marine caverns at the base of the cliff that are positioned at the point of strongest wave attack. These caverns likely occupy the future site of development of a sea arch that will threaten the OP building. The mass movement potential at the Rudder's command post area is low to moderate. The greatest risk there is associated with soil wedge failures at the top of the cliffs.

Systematic assessment of scaffold hopping versus activity cliff formation across bioactive compound classes following a molecular hierarchy.

PubMed

Stumpfe, Dagmar; Dimova, Dilyana; Bajorath, Jürgen

2015-07-01

Scaffold hopping and activity cliff formation define opposite ends of the activity landscape feature spectrum. To rationalize these events at the level of scaffolds, active compounds involved in scaffold hopping were required to contain topologically distinct scaffolds but have only limited differences in potency, whereas compounds involved in activity cliffs were required to share the same scaffold but have large differences in potency. A systematic search was carried out for compounds involved in scaffold hopping and/or activity cliff formation. Results obtained for compound data sets covering more than 300 human targets revealed clear trends. If scaffolds represented multiple but fewer than 10 active compounds, nearly 90% of all scaffolds were exclusively involved in hopping events. With increasing compound coverage, the fraction of scaffolds involved in both scaffold hopping and activity cliff formation significantly increased to more than 50%. However, ∼40% of the scaffolds representing large numbers of active compounds continued to be exclusively involved in scaffold hopping. More than 200 scaffolds with broad target coverage were identified that consistently represented potent compounds and yielded an abundance of scaffold hops in the low-nanomolar range. These and other subsets of scaffolds we characterized are of prime interest for structure-activity relationship (SAR) exploration and compound design. Therefore, the complete scaffold classification generated in the course of our analysis is made freely available. Copyright © 2015 Elsevier Ltd. All rights reserved.

Slope, Scarp and Sea Cliff Instability Susceptibility Mapping for Planning Regulations in Almada County, Portugal

NASA Astrophysics Data System (ADS)

Marques, Fernando; Queiroz, Sónia; Gouveia, Luís; Vasconcelos, Manuel

2017-12-01

In Portugal, the modifications introduced in 2008 and 2012 in the National Ecological Reserve law (REN) included the mandatory study of slope instability, including slopes, natural scarps, and sea cliffs, at municipal or regional scale, with the purpose of avoiding the use of hazardous zones with buildings and other structures. The law also indicates specific methods to perform these studies, with different approaches for slope instability, natural scarps and sea cliffs. The methods used to produce the maps required by REN law, with modifications and improvements to the law specified methods, were applied to the 71 km2 territory of Almada County, and included: 1) Slope instability mapping using the statistically based Information Value method validated with the landslide inventory using ROC curves, which provided an AAC=0.964, with the higher susceptibility zones which cover at least 80% of the landslides of the inventory to be included in REN map. The map was object of a generalization process to overcome the inconveniences of the use of a pixel based approach. 2) Natural scarp mapping including setback areas near the top, defined according to the law and setback areas near the toe defined by the application of the shadow angle calibrated with the major rockfalls which occurred in the study area; 3) Sea cliffs mapping including two levels of setback zones near the top, and one setback zone at the cliffs toe, which were based on systematic inventories of cliff failures occurred between 1947 and 2010 in a large scale regional littoral monitoring project. In the paper are described the methods used and the results obtained in this study, which correspond to the final maps of areas to include in REN. The results obtained in this study may be considered as an example of good practice of the municipal authorities in terms of solid, technical and scientifically supported regulation definitions, hazard prevention and safe and sustainable land use management.

Relationships between the stable isotopic signatures of living and fossil foraminifera in Monterey Bay, California

NASA Astrophysics Data System (ADS)

Martin, Jonathan B.; Day, Shelley A.; Rathburn, Anthony E.; Perez, M. Elena; Mahn, Chris; Gieskes, Joris

2004-04-01

Fossil foraminifera are critical to paleoceanographic reconstructions including estimates of past episodes of methane venting. These reconstructions rely on benthic foraminifera incorporating and retaining unaltered the ambient isotopic compositions of pore fluids and bottom waters. Comparisons are made here of isotopic compositions of abundant live and fossil foraminifera (Uvigerina peregrina, Epistominella pacifica, Bulimina mexicana, and Globobulimina pacifica) collected in Monterey Bay, CA from two cold seeps (Clam Flats and Extrovert Cliffs) and from sediments ˜5 m outside of the Clam Flats seep. Clam Flats has steep δ13CDIC gradients (to <-45‰), but DIC at Extrovert Cliffs is less enriched in 12C (to approximately -22‰). Oxygen isotope values of fossil foraminifera at Clam Flats are ˜1.5‰ enriched in 18O over the living foraminifera, as well as those of both live and fossil foraminifera at Extrovert Cliffs, suggesting they may have lived during the last glacial maximum. Statistical comparisons (Student's t and Kolmogorov-Smirnov tests) of δ13C and δ18O values indicate that live and fossil foraminifera come from different populations at both Clam Flats and Extrovert Cliffs. At Clam Flats, the difference appears to result from alteration enriching some fossil foraminifera in 12C over live foraminifera. At Extrovert Cliffs, the fossil foraminifera are enriched in 13C over the live foraminifera, suggesting they lived prior to the onset of venting and thus that venting began recently. The short time of venting at Extrovert Cliffs may be responsible for the less alteration there compared with Clam Flats. These results indicate that preservation of foraminifera is likely to be poor within long-lived cold seeps, but that foraminifera living in the surrounding sediment may incorporate and preserve broad basin-wide changes in isotopic compositions of the ambient water.

The 50s cliff: a decline in perceptuo-motor learning, not a deficit in visual motion perception.

PubMed

Ren, Jie; Huang, Shaochen; Zhang, Jiancheng; Zhu, Qin; Wilson, Andrew D; Snapp-Childs, Winona; Bingham, Geoffrey P

2015-01-01

Previously, we measured perceptuo-motor learning rates across the lifespan and found a sudden drop in learning rates between ages 50 and 60, called the "50s cliff." The task was a unimanual visual rhythmic coordination task in which participants used a joystick to oscillate one dot in a display in coordination with another dot oscillated by a computer. Participants learned to produce a coordination with a 90° relative phase relation between the dots. Learning rates for participants over 60 were half those of younger participants. Given existing evidence for visual motion perception deficits in people over 60 and the role of visual motion perception in the coordination task, it remained unclear whether the 50s cliff reflected onset of this deficit or a genuine decline in perceptuo-motor learning. The current work addressed this question. Two groups of 12 participants in each of four age ranges (20s, 50s, 60s, 70s) learned to perform a bimanual coordination of 90° relative phase. One group trained with only haptic information and the other group with both haptic and visual information about relative phase. Both groups were tested in both information conditions at baseline and post-test. If the 50s cliff was caused by an age dependent deficit in visual motion perception, then older participants in the visual group should have exhibited less learning than those in the haptic group, which should not exhibit the 50s cliff, and older participants in both groups should have performed less well when tested with visual information. Neither of these expectations was confirmed by the results, so we concluded that the 50s cliff reflects a genuine decline in perceptuo-motor learning with aging, not the onset of a deficit in visual motion perception.

Landscape development in an hyperarid sandstone environment along the margins of the Dead Sea fault: Implications from dated rock falls

USGS Publications Warehouse

Matmon, A.; Shaked, Y.; Porat, N.; Enzel, Y.; Finkel, R.; Lifton, N.; Boaretto, E.; Agnon, A.

2005-01-01

In this study, we explored the spatial and temporal relations between boulders and their original in-situ locations on sandstone bedrock cliffs. This was accomplished by combining field observations with dating methods using cosmogenic isotopes (10Be and 14C) and optically stimulated luminescence (OSL). Our conclusions bear both on the landscape evolution and cliff retreat process in the hyperarid region of Timna and on the methodology of estimating exposure ages using cosmogenic isotopes. We recognize three discrete rock fall events, at 31 ka, 15 ka, and 4 ka. In this hyperarid region, the most plausible triggering mechanism for rock fall events is strong ground acceleration caused by earthquakes generated by the nearby Dead Sea fault (DSF). Our record, however, under represents the regional earthquake record implying that ongoing development of detachment cracks prior to the triggering event might be slower than the earthquake cycle. Cliff retreat rates calculated using the timing of rock fall events and estimated thickness of rock removed in each event range between 0.14 m ky-1 and 2 m ky-1. When only full cycles are considered, we derive a more realistic range of 0.4 m ky-1 to 0.7 m ky-1. These rates are an order of magnitude faster than the calculated rate of surface lowering in the area. We conclude that sandstone cliffs at Timna retreat through episodic rock fall events that preserve the sharp, imposing, landscape characteristic to this region and that ongoing weathering of the cliff faces is minor. A 10%-20% difference in the 10Be concentrations in samples from matching boulder and cliff faces that have identical exposure histories and are located only a few meters apart indicates that cosmogenic nuclide production rates are sensitive to shielding and vary spatially over short distances. However, uncertainties associated with age calculations yielded boulder and matching cliff face ages that are similar within 1 ??. The use of external constraints in the form of field relations and OSL dating helped to establish each pair's age. The agreement between calculated 14C and 10Be ages indicates that the accumulation of 10Be at depth by the capture of slow deep-penetrating muons was properly accounted for in the study. ?? 2005 Elsevier B.V. All rights reserved.

Rock face stability analysis and potential rockfall source detection in Yosemite Valley

NASA Astrophysics Data System (ADS)

Matasci, B.; Stock, G. M.; Jaboyedoff, M.; Oppikofer, T.; Pedrazzini, A.; Carrea, D.

2012-04-01

Rockfall hazard in Yosemite Valley is especially high owing to the great cliff heights (~1 km), the fracturing of the steep granitic cliffs, and the widespread occurrence of surface parallel sheeting or exfoliation joints. Between 1857 and 2011, 890 documented rockfalls and other slope movements caused 15 fatalities and at least 82 injuries. The first part of this study focused on realizing a structural study for Yosemite Valley at both regional (valley-wide) and local (rockfall source area) scales. The dominant joint sets were completely characterized by their orientation, persistence, spacing, roughness and opening. Spacing and trace length for each joint set were accurately measured on terrestrial laser scanning (TLS) point clouds with the software PolyWorks (InnovMetric). Based on this fundamental information the second part of the study aimed to detect the most important failure mechanisms leading to rockfalls. With the software Matterocking and the 1m cell size DEM, we calculated the number of possible failure mechanisms (wedge sliding, planar sliding, toppling) per cell, for several cliffs of the valley. Orientation, spacing and persistence measurements directly issued from field and TLS data were inserted in the Matterocking calculations. TLS point clouds are much more accurate than the 1m DEM and show the overhangs of the cliffs. Accordingly, with the software Coltop 3D we developed a methodology similar to the one used with Matterocking to identify on the TLS point clouds the areas of a cliff with the highest number of failure mechanisms. Exfoliation joints are included in this stability analysis in the same way as the other joint sets, with the only difference that their orientation is parallel to the local cliff orientation and thus variable. This means that, in two separate areas of a cliff, the exfoliation joint set is taken into account with different dip direction and dip, but its effect on the stability assessment is the same. Areas with a high density of possible failure mechanisms are shown to be more susceptible to rockfalls, demonstrating a link between high fracture density and rockfall susceptibility. This approach enables locating the most probable future rockfall sources and provides key elements needed to evaluate the potential volume and run-out distance of rockfall blocks. This information is used to improve rockfall hazard assessment in Yosemite Valley and elsewhere.

Dry calving processes at the ice cliff of an antarctic local glacier: the study case of Strandline Glacier (Northern Victoria Land, Antarctica)

NASA Astrophysics Data System (ADS)

Smiraglia, C.; Motta, M.; Vassena, G.; Diolaiuti, G.

2003-04-01

In Antartic coastal area, where the ice sheet and the large outlet glaciers do not reach the sea and where some rugged mountain chains are often present, many small glaciers can be found. They are the so called local or alpine type glaciers, which have their terminus ground-based such as the real alpine glaciers and rarely reach the main valley floors. They are practically isolated and independent from the supply flowing down from the plateau and their mass balance is mainly controlled by sublimation and aeolic erosion and accumulation. The glaciers closer to the coast are submitted to the melting as well, and when the terminus is cliff-shaped they are also affected by dry calving. The most known and studied Antarctic local glaciers are placed in the Dry Valleys region (Chinn, 1985), but this kind of glaciers is also diffused all along the Northern Victoria Land coastal region (Chinn and others, 1989). Since the first Italian Antarctic expedition (1985), many studies have been carried out on this type of glaciers, which can be usefull for detailed mass balance evaluations and for obtaining information about the effects of the present climatic dynamics on the Antarctic coastal environment (Baroni and Orombelli, 1987; Baroni and others, 1995; Meneghel, 1999; Vassena and others., 2001). The Strandline Glacier (74 41 S; 164 07 E), in particular is a small alpine glacier (0,79 kmq) on the coast of Terra Nova Bay, Northern Victoria Land; it is a cold glacier where accumulation and ablation basins are mainly controlled by wind processes. Its terminus forms in the central part a grounded ice cliff about 30 m high, about 130 m far from the sea. On that glacier mass balance, surface velocity and calving rate were measured. During the southern summer season 2000-2001 many topographycal profiles of the ice cliff were surveyed by using both classical topographical and glaciological methods (total station and stakes) and GPS technique. It was so possible to detect the short term changes in ice cliff position (a retreat of 10 m in the central part of the front on 15 days) caused by crack propagation from the glacier surface and calving of ice flakes from the cliff face; during the warmest days also melting occurred along glacier surface and on the cliff. In the same period of 15 days ice thickness near the cliff boundary decreased about 30 cm. The collected measures regard also surface velocities and meteorological data . This work was carried out within the framework of the Project on Glaciology and Palaeoclimatology of the Programma Nazionale Ricerche in Antartide (PNRA), national co-ordinator Prof. G. Orombelli.

77 FR 57647 - Endangered and Threatened Wildlife and Plants; Endangered Status for 23 Species on Oahu and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-18

... Wildlife Service Web site and Field Office set out above, and may also be included in the preamble or at...: coastal, lowland dry, lowland mesic, lowland wet, montane wet, dry cliff, and wet cliff (Table 1). Table 1... amplectens. Lowland Dry Plants: Bidens amplectens, Doryopteris takeuchii, Pleomele forbesii. Lowland Mesic...

33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Persons desiring to transit the area of the security zone may contact the Captain of the Port at telephone... REGULATED NAVIGATION AREAS AND LIMITED ACCESS AREAS Specific Regulated Navigation Areas and Limited Access Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake...

76 FR 81994 - UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-29

... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit 3; Exemption 1.0 Background: UniStar Nuclear Energy (UNE) submitted to the U.S. Nuclear Regulatory Commission (NRC or the Commission ) a...

77 FR 48533 - Notice of Inventory Completion: The Robert S. Peabody Museum of Archaeology, Phillips Academy...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-14

... Portage Band, Leech Lake Band, White Earth Band); Red Cliff Band of Lake Superior Chippewa Indians of Wisconsin; and the Sokaogon Chippewa Community, Wisconsin. History and Description of the Remains On an... Lake Band, Mille Lacs Band, White Earth Band); Red Cliff Band of Lake Superior Chippewa Indians of...

The Role of Source Material in Basin Sedimentation, as Illustrated within Eureka Valley, Death Valley National Park, CA.

NASA Astrophysics Data System (ADS)

Lawson, M. J.; Yin, A.; Rhodes, E. J.

2015-12-01

Steep landscapes are known to provide sediment to sink regions, but often petrological factors can dominate basin sedimentation. Within Eureka Valley, in northwestern Death Valley National Park, normal faulting has exposed a steep cliff face on the western margin of the Last Chance range with four kilometers of vertical relief from the valley floor and an angle of repose of nearly 38 degrees. The cliff face is composed of Cambrian limestone and dolomite, including the Bonanza King, Carrara and Wood Canyon formations. Interacting with local normal faulting, these units preferentially break off the cliff face in coherent blocks, which result in landslide deposits rather than as finer grained material found within the basin. The valley is well known for a large sand dune, which derives its sediment from distal sources to the north, instead of from the adjacent Last Chance Range cliff face. During the Holocene, sediment is sourced primary from the northerly Willow Wash and Cucomungo canyon, a relatively small drainage (less than 80 km2) within the Sylvan Mountains. Within this drainage, the Jurassic quartz monzonite of Beer Creek is heavily fractured due to motion of the Fish Valley Lake - Death Valley fault zone. Thus, the quartz monzonite is more easily eroded than the well-consolidated limestone and dolomite that forms the Last Change Range cliff face. As well, the resultant eroded material is smaller grained, and thus more easily transported than the limestone. Consequently, this work highlights an excellent example of the strong influence that source material can have on basin sedimentation.

Roles of Thermophiles and Fungi in Bitumen Degradation in Mostly Cold Oil Sands Outcrops

PubMed Central

Wong, Man-Ling; An, Dongshan; Caffrey, Sean M.; Soh, Jung; Dong, Xiaoli; Sensen, Christoph W.; Oldenburg, Thomas B. P.; Larter, Steve R.

2015-01-01

Oil sands are surface exposed in river valley outcrops in northeastern Alberta, where flat slabs (tablets) of weathered, bitumen-saturated sandstone can be retrieved from outcrop cliffs or from riverbeds. Although the average yearly surface temperature of this region is low (0.7°C), we found that the temperatures of the exposed surfaces of outcrop cliffs reached 55 to 60°C on sunny summer days, with daily maxima being 27 to 31°C. Analysis of the cooccurrence of taxa derived from pyrosequencing of 16S/18S rRNA genes indicated that an aerobic microbial network of fungi and hydrocarbon-, methane-, or acetate-oxidizing heterotrophic bacteria was present in all cliff tablets. Metagenomic analyses indicated an elevated presence of fungal cytochrome P450 monooxygenases in these samples. This network was distinct from the heterotrophic community found in riverbeds, which included fewer fungi. A subset of cliff tablets had a network of anaerobic and/or thermophilic taxa, including methanogens, Firmicutes, and Thermotogae, in the center. Long-term aerobic incubation of outcrop samples at 55°C gave a thermophilic microbial community. Analysis of residual bitumen with a Fourier transform ion cyclotron resonance mass spectrometer indicated that aerobic degradation proceeded at 55°C but not at 4°C. Little anaerobic degradation was observed. These results indicate that bitumen degradation on outcrop surfaces is a largely aerobic process with a minor anaerobic contribution and is catalyzed by a consortium of bacteria and fungi. Bitumen degradation is stimulated by periodic high temperatures on outcrop cliffs, which cause significant decreases in bitumen viscosity. PMID:26209669

Cliff swallows Petrochelidon pyrrhonota as bioindicators of environmental mercury, Cache Creek Watershed, California

USGS Publications Warehouse

Hothem, Roger L.; Trejo, Bonnie S.; Bauer, Marissa L.; Crayon, John J.

2008-01-01

To evaluate mercury (Hg) and other element exposure in cliff swallows (Petrochelidon pyrrhonota), eggs were collected from 16 sites within the mining-impacted Cache Creek watershed, Colusa, Lake, and Yolo counties, California, USA, in 1997-1998. Nestlings were collected from seven sites in 1998. Geometric mean total Hg (THg) concentrations ranged from 0.013 to 0.208 ??g/g wet weight (ww) in cliff swallow eggs and from 0.047 to 0.347 ??g/g ww in nestlings. Mercury detected in eggs generally followed the spatial distribution of Hg in the watershed based on proximity to both anthropogenic and natural sources. Mean Hg concentrations in samples of eggs and nestlings collected from sites near Hg sources were up to five and seven times higher, respectively, than in samples from reference sites within the watershed. Concentrations of other detected elements, including aluminum, beryllium, boron, calcium, manganese, strontium, and vanadium, were more frequently elevated at sites near Hg sources. Overall, Hg concentrations in eggs from Cache Creek were lower than those reported in eggs of tree swallows (Tachycineta bicolor) from highly contaminated locations in North America. Total Hg concentrations were lower in all Cache Creek egg samples than adverse effects levels established for other species. Total Hg concentrations in bullfrogs (Rana catesbeiana) and foothill yellow-legged frogs (Rana boylii) collected from 10 of the study sites were both positively correlated with THg concentrations in cliff swallow eggs. Our data suggest that cliff swallows are reliable bioindicators of environmental Hg. ?? Springer Science+Business Media, LLC 2007.

Degrees of Consciousness in the Communication of Actions and Events on the Visual Cliff. No. 58.

ERIC Educational Resources Information Center

Bierschenk, Bernhard

The consciousness of dizygotic twins in their communication of actions and events as seen in the visual cliff pictures published by E. J. Gibson and R. D. Walk (1960) was studied in Sweden. In the process of communication, many different state spaces are generated. The methodology demonstrates that ecological and biophysical properties of language…

77 FR 34285 - Safety Zone; 2012 Ironman U.S. Championship Swim, Hudson River, Fort Lee, NJ

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

...-AA00 Safety Zone; 2012 Ironman U.S. Championship Swim, Hudson River, Fort Lee, NJ AGENCY: Coast Guard... safety zone on the navigable waters of the Hudson River in the vicinity of Englewood Cliffs and Fort Lee... the Hudson River in the vicinity of Englewood Cliffs and Fort Lee, New Jersey. This swim event poses...

Geologic Map of the House Rock Valley Area, Coconino County, Northern Arizona

USGS Publications Warehouse

Billingsley, George H.; Priest, Susan S.

2010-01-01

This geologic map is a cooperative effort of the U.S. Geological Survey (USGS), the Bureau of Land Management, the National Park Service, and the U.S. Forest Service to provide a geologic database for resource management officials and visitor information services. This map was produced in response to information needs related to a proposed withdrawal of three segregated land areas near Grand Canyon National Park, Arizona, from new hard rock mining activity. House Rock Valley was designated as the east parcel of the segregated lands near the Grand Canyon. This map was needed to provide connectivity for the geologic framework of the Grand Canyon segregated land areas. This geologic map of the House Rock Valley area encompasses approximately 280 mi2 (85.4 km2) within Coconino County, northern Arizona, and is bounded by longitude 111 degrees 37'30' to 112 degrees 05' W. and latitude 36 degrees 30' to 36 degrees 50' N. The map area is in the eastern part of the Arizona Strip, which lies within the southern Colorado Plateaus geologic province (herein Colorado Plateau). The Arizona Strip is the part of Arizona lying north of the Colorado River. The map is bound on the east by the Colorado River in Marble Canyon within Grand Canyon National Park and Glen Canyon National Recreation Area, on the south and west by the Kaibab National Forest and Grand Canyon National Game Preserve, and on the north by the Vermilion Cliffs Natural Area, the Paria Canyon Vermilion Cliffs Wilderness Area, and the Vermilion Cliffs National Monument. House Rock State Buffalo Ranch also bounds the southern edge of the map area. The Bureau of Land Management Arizona Field Office in St. George, Utah, manages public lands of the Vermilion Cliffs Natural Area, Paria Canyon - Vermilion Cliffs Wilderness and Vermilion Cliffs National Monument. The North Kaibab Ranger District in Fredonia, Arizona, manages U.S. Forest Service land along the west edge of the map area and House Rock State Buffalo Ranch. Other lands include about 13 sections of Arizona State land, about ? of a section of private land along House Rock Wash, and about 1? sections of private land at Cliff Dwellers Lodge, Vermilion Cliffs Lodge, and Marble Canyon, Arizona. Landmark features within the map area include the Vermilion Cliffs, Paria Plateau, Marble Canyon, and House Rock Valley. Surface drainage in House Rock Valley is to the east toward the Colorado River in Marble Canyon. Large tributaries of Marble Canyon from north to south include Badger Canyon, Soap Creek, Rider Canyon, North Canyon, Bedrock Canyon, and South Canyon. Elevations range from about 2,875 ft (876 m) at the Colorado River in the southeast corner of the map to approximately 7,355 ft (2,224 m) on the east rim of Paria Plateau along the north-central edge of the map area. Three small settlements are in the map area along U.S. Highway 89A, Cliff Dwellers Lodge, Vermilion Cliffs Lodge, and Marble Canyon, Arizona. The community of Jacob Lake is about 9 mi (14.5 km) west of House Rock Valley on the Kaibab Plateau. Lees Ferry is 5 mi (8 km) north of Marble Canyon and marks the confluence of the Paria and Colorado Rivers and the beginning of Marble Canyon. U.S. Highway 89A provides access to the northern part of the map area. Dirt roads lead south into House Rock Valley from U.S. Highway 89A and are collectively maintained by the Bureau of Land Management, the U.S. National Forest Service, and the Grand Canyon Trust. House Rock Valley is one of the few remaining areas where uniform geologic mapping is needed for connectivity to the regional Grand Canyon geologic framework. This information is useful to Federal and State resource managers who direct environmental and land management programs that encompass such issues as range management, biological studies, flood control, water, and mineral-resource investigations. The geologic information will support future and ongoing geologic investigations and scientific studies

Lidar-Based Rock-Fall Hazard Characterization of Cliffs

USGS Publications Warehouse

Collins, Brian D.; Greg M.Stock,

2017-01-01

Rock falls from cliffs and other steep slopes present numerous challenges for detailed geological characterization. In steep terrain, rock-fall source areas are both dangerous and difficult to access, severely limiting the ability to make detailed structural and volumetric measurements necessary for hazard assessment. Airborne and terrestrial lidar survey methods can provide high-resolution data needed for volumetric, structural, and deformation analyses of rock falls, potentially making these analyses straightforward and routine. However, specific methods to collect, process, and analyze lidar data of steep cliffs are needed to maximize analytical accuracy and efficiency. This paper presents observations showing how lidar data sets should be collected, filtered, registered, and georeferenced to tailor their use in rock fall characterization. Additional observations concerning surface model construction, volumetric calculations, and deformation analysis are also provided.

Accurate 3D point cloud comparison and volumetric change analysis of Terrestrial Laser Scan data in a hard rock coastal cliff environment

NASA Astrophysics Data System (ADS)

Earlie, C. S.; Masselink, G.; Russell, P.; Shail, R.; Kingston, K.

2013-12-01

Our understanding of the evolution of hard rock coastlines is limited due to the episodic nature and ';slow' rate at which changes occur. High-resolution surveying techniques, such as Terrestrial Laser Scanning (TLS), have just begun to be adopted as a method of obtaining detailed point cloud data to monitor topographical changes over short periods of time (weeks to months). However, the difficulties involved in comparing consecutive point cloud data sets in a complex three-dimensional plane, such as occlusion due to surface roughness and positioning of data capture point as a result of a consistently changing environment (a beach profile), mean that comparing data sets can lead to errors in the region of 10 - 20 cm. Meshing techniques are often used for point cloud data analysis for simple surfaces, but in surfaces such as rocky cliff faces, this technique has been found to be ineffective. Recession rates of hard rock coastlines in the UK are typically determined using aerial photography or airborne LiDAR data, yet the detail of the important changes occurring to the cliff face and toe are missed using such techniques. In this study we apply an algorithm (M3C2 - Multiscale Model to Model Cloud Comparison), initially developed for analysing fluvial morphological change, that directly compares point to point cloud data using surface normals that are consistent with surface roughness and measure the change that occurs along the normal direction (Lague et al., 2013). The surfaces changes are analysed using a set of user defined scales based on surface roughness and registration error. Once the correct parameters are defined, the volumetric cliff face changes are calculated by integrating the mean distance between the point clouds. The analysis has been undertaken at two hard rock sites identified for their active erosion located on the UK's south west peninsular at Porthleven in south west Cornwall and Godrevy in north Cornwall. Alongside TLS point cloud data, in-situ measurements of the nearshore wave climate, using a pressure transducer, offshore wave climate from a directional wavebuoy, and rainfall records from nearby weather stations were collected. Combining beach elevation information from the georeferenced point clouds with a continuous time series of wave climate provides an indication of the variation in wave energy delivered to the cliff face. The rates of retreat were found to agree with the existing rates that are currently used in shoreline management. The additional geotechnical detail afforded by applying the M3C2 method to a hard rock environment provides not only a means of obtaining volumetric changes with confidence, but also a clear illustration of the locations of failure on the cliff face. Monthly cliff scans help to narrow down the timings of failure under energetic wave conditions or periods of heavy rainfall. Volumetric changes and sensitive regions to failure established using this method allows us to capture episodic changes to the cliff face at a high resolution (1 - 2 cm) that are otherwise missed using lower resolution techniques typically used for shoreline management, and to understand in greater detail the geotechnical behaviour of hard rock cliffs and determine rates of erosion with greater accuracy.

Politics and the Glass Cliff: Evidence that Women Are Preferentially Selected to Contest Hard-to-Win Seats

ERIC Educational Resources Information Center

Ryan, Michelle K.; Haslam, S. Alexander; Kulich, Clara

2010-01-01

Recent archival and experimental research has revealed that women are more likely than men to be appointed to leadership positions when an organization is in crisis. As a result, women often confront a "glass cliff" in which their position as leader is precarious. Our first archival study examined the 2005 UK general election and found…

30. Photocopy of photograph (Frank O. Braynard Collection, Sea Cliff, ...

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

30. Photocopy of photograph (Frank O. Braynard Collection, Sea Cliff, NY), date and photographer unknown, probably c1935-40 VIEW NORTHWEST OF WEST 55TH ST. PIER INSHORE FACADE; QUEEN OF BERMUDA AND MONARCH OF BERMUDA MOORED ON EITHER SIDE. - West 55th Street & West 56th Street Piers, Hudson River at West Fifty-fifth & West Fifty-sixth Streets, Manhattan, New York County, NY

Rock fall dynamics and deposition: an integrated analysis of the 2009 Ahwiyah Point rock fall, Yosemite National Park, USA.

USGS Publications Warehouse

Valerie L. Zimmer,; Collins, Brian D.; Greg M. Stock,; Nicholas Sitar,

2012-01-01

We analyzed a combination of airborne and terrestrial LiDAR, high-resolution photography, seismic, and acoustic data in order to gain insights into the initiation, dynamics, and talus deposition of a complex rock fall. A large (46 700 m3) rock fall originated from near Ahwiyah Point in eastern Yosemite Valley and fell a total of 730 m to the valley floor on 28 March 2009. Analyses of remote sensing, seismic, and acoustic data were integrated to reconstruct the rock fall, which consisted of (1) the triggering of a 25 400 m3 rock block in an area of intersecting and sometimes highly weathered joint planes, (2) the sliding and subsequent ballistic trajectory of the block from a steeply dipping ledge, (3) dislodging of additional rock from the cliff surface from beneath the rock fall source area, (4) a mid-cliff ledge impact that detached a volume of rock nearly equivalent in volume to the initial block, (5) sliding of the deteriorating rock mass down the remainder of the cliff, and (6) final impact at the base of the cliff that remobilized the existing talus downward and outward and produced an airblast that knocked down hundreds of trees. The depositional geomorphology indicates that the porosity of the fresh talus is significantly lower than that expected for typical blocky talus slopes, likely because the rock debris from this event was pulverized into smaller, more poorly sorted fragments and densified via dynamic compaction when compared to less energetic, fragmental-type rock falls. These results suggest that accumulation of individual rock-fall boulders tends to steepen talus slopes, whereas large, energetic rock falls tend to flatten them. Detachment and impact signals were recorded by seismic and acoustic instruments and highlight the potential use of this type of instrumentation for generalized rock fall monitoring, while LiDAR and photography data were able to quantify the cliff geometry, rock fall volume, source and impact locations, and geomorphological changes to the cliff and talus.

Erosion processes in molassic cliffs: the role of the rock surface temperature and atmospheric conditions

NASA Astrophysics Data System (ADS)

Carrea, Dario; Abellán, Antonio; Guerin, Antoine; Jaboyedoff, Michel; Voumard, Jérémie

2014-05-01

The morphology of the Swiss Plateau is modeled by numerous steep cliffs of Molasse. These cliffs are mainly composed of sub-horizontal alternated layers of sandstone, shale and conglomerates deposed in the Alps foreland basin during the Tertiary period. These Molasse cliffs are affected by erosion processes inducing numerous rockfall events. Thus, it is relevant to understand how different external factors influence Molasse erosion rates. In this study, we focus on analyzing temperature variation during a winter season. As pilot study area we selected a cliff which is formed by a sub-horizontal alternation of outcropping sandstone and shale. The westward facing test site (La Cornalle, Vaud, Switzerland), which is a lateral scarp of a slow moving landslide area, is currently affected by intense erosion. Regarding data acquisition, we monitored both in-situ rock and air temperatures at 15 minutes time-step since October 2013: (1) on the one hand we measured Ground Surface Temperature (GST) at near-surface (0.1 meter depth) using a GST mini-datalogger M-Log5W-Rock model; (2) On the other hand we monitored atmospheric conditions using a weather station (Davis Vantage pro2 plus) collecting numerous parameters (i.e. temperature, irradiation, rain, wind speed, etc.). Furthermore, the area was also seasonally monitored by Ground-Based (GB) LiDAR since 2010 and monthly monitored since September 2013. In order to understand how atmospheric conditions (such as freeze and thaw effect) influence the erosion of the cliff, we modeled the temperature diffusion through the rock mass. To this end, we applied heat diffusion and radiation equation using a 1D temperature profile, obtaining as a result both temperature variations at different depths together with the location of the 0°C isotherm. Our model was calibrated during a given training set using both in-situ rock temperatures and atmospheric conditions. We then carried out a comparison with the rockfall events derived from the 3D GB-LiDAR datasets in order to quantify the erosion rates and to correlate it with atmospheric conditions, aiming to analyze which parameters influence Molasse erosion process.

Landslides: Geomorphology and Sea Cliff Hazard Potential, Santa Barbara - Isla Vista, California J.F. Klath and E.A. Keller

NASA Astrophysics Data System (ADS)

Klath, J. F.; Keller, E. A.

2015-12-01

Coastal areas are often characterized by high population densities in an ever changing, dynamic environment. The world's coasts are often dominated by steeply sloping sea cliffs, the morphology of which reflects rock type, wave erosion, and surface erosion, as well as human activities such changing vegetation, urban runoff, and construction of coastal defenses. The Santa Barbara and Goleta area, with over 17 km of sea cliffs and beaches, extends from Santa Barbara Point west to the hamlet of Isla Vista. A deeper understanding of the local geology and the physical processes generating slope failure and, thus, landward cliff retreat is important for general public safety, as well as future development and planning. Our research objective includes assessment of landslide hazard potential through investigation of previous landslides and how these events relate to various physical variables and characteristics within the surrounding bedrock. How does landslide frequency, volume, and type relate to varying local bedrock and structure? Two geologic formations dominate the sea cliffs of the Santa Barbara area: Monterey shale (upper, middle, and lower) and Monterey Sisquoc shale. Geology varies from hard cemented shale and diatomaceous, low specific gravity shale to compaction shale. Variations in landslide characteristics are linked closely to the geology of a specific site that affects how easily rock units are weathered and eroded by wave erosion, naturally occurring oil and water seeps, burnt shale events, and landslide type and frequency on steeply dipped bedding planes/daylighting beds. Naturally occurring features linked to human processes often weaken bedrock and, thus, increase the likelihood of landslides. We categorize landslide frequency, type, and triggers; location of beach access, drainage pipes, and water; and oil and tar seeps in order to develop suggestions to minimize landslide potential. Lastly, using previously published erosion cliff retreat rates and sea level rise estimates, a map displaying likely position of the coastline by 2100 will be created. This information will be useful to the county of Santa Barbara, California when considering future development and hazard mitigation plans.

Immune Responses of a Native and an Invasive Bird to Buggy Creek Virus (Togaviridae: Alphavirus) and Its Arthropod Vector, the Swallow Bug (Oeciacus vicarius)

PubMed Central

Fassbinder-Orth, Carol A.; Barak, Virginia A.; Brown, Charles R.

2013-01-01

Invasive species often display different patterns of parasite burden and virulence compared to their native counterparts. These differences may be the result of variability in host-parasite co-evolutionary relationships, the occurrence of novel host-parasite encounters, or possibly innate differences in physiological responses to infection between invasive and native hosts. Here we examine the adaptive, humoral immune responses of a resistant, native bird and a susceptible, invasive bird to an arbovirus (Buggy Creek virus; Togaviridae: Alphavirus) and its ectoparasitic arthropod vector (the swallow bug; Oeciacus vicarius). Swallow bugs parasitize the native, colonially nesting cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that occupies nests in cliff swallow colonies. We measured levels of BCRV-specific and swallow bug-specific IgY levels before nesting (prior to swallow bug exposure) and after nesting (after swallow bug exposure) in house sparrows and cliff swallows in western Nebraska. Levels of BCRV-specific IgY increased significantly following nesting in the house sparrow but not in the cliff swallow. Additionally, house sparrows displayed consistently higher levels of swallow bug-specific antibodies both before and after nesting compared to cliff swallows. The higher levels of BCRV and swallow bug specific antibodies detected in house sparrows may be reflective of significant differences in both antiviral and anti-ectoparasite immune responses that exist between these two avian species. To our knowledge, this is the first study to compare the macro- and microparasite-specific immune responses of an invasive and a native avian host exposed to the same parasites. PMID:23460922

Characterization of Joint Sets Through UAV Photogrammetry on Sedimentary Rock Sea Cliffs and Abrasion Platforms in Northern Taiwan

NASA Astrophysics Data System (ADS)

Hsieh, P. C.; LU, A.; Yeh, C. H.; Huang, W. K.; Lin, H. H.; Lin, M. L.

2017-12-01

Rockfall hazards are very common in obsequent slope and oblique slope. In the coastal area of northern Taiwan, many sea cliffs are formed by obsequent slope and oblique slope. A famous case of rockfall failure happened on Aug. 31, 2013, a 150-ton rock block fell on the highway in Badouzi, Keelung, during a high intensity rainfall event which was caused by Typhoon No.15 (Kong-rey). To reduce this kind of rockfall hazard, it is important to characterize discontinuous planes in the bedrock because rock blocks are mainly divided from bedrock by two or more sets of discontinuous planes including joint planes and the bedding plane. For doing characterization of those fracture patterns of joint sets, it is necessary to do detailed field investigations. However, the survey of discontinuous planes, especially joint sets, are usually difficult and cannot get enough characterization data about joint sets. The first reason is that doing field investigations on the surface of sea cliffs is very dangerous and difficult for engineers or geologists to approach the upper part of outcrop. The second reason is the complexity of joint sets. In Badouzi area, each cliff is constituted by many different layers such as sandstone, shale, or alternations of sandstone and shale, and each layer has different fracture pattern of joint sets. In this study, we use UAV photogrammetry as a solution of these difficulties. UAV photogrammetry can produce a high-resolution digital surface model (DSM), orthophoto, and anaglyph of sea cliffs and abrasion platforms. Than we use self-developed geoprocessing toolsets to auto-trace joint planes with DSM data and produce fracture pattern of joint sets semi-automatically and systematically. Our method can provide basic information for rock mass rating on rock slope stability and rockfall hazards evaluation.

Borax in the supraglacial moraine of the Lewis Cliff, Buckley Island quadrangle--first Antarctic occurrence

USGS Publications Warehouse

Fitzpatrick, J.J.; Muhs, D.R.

1989-01-01

During the 1987-1988 austral summer field season, membersof the south party of the antarctic search for meteorites south-ern team* working in the Lewis Cliff/Colbert Hills region dis-covered several areas of unusual mineralization within theLewis Cliff ice tongue and its associated moraine field (figure1). The Lewis Cliff ice tongue (84°15'S 161°25'E) is a meteorite-stranding surface of ablating blue ice, about 2.3 by 7.0 kilo-meters, bounded on the west by the Lewis Cliff, on the northand northeast by a large supraglacial moraine, and on the eastby the Colbert Hills. To the south it opens to the Walcott Névé.Because it is a meteorite-stranding surface, the major component of ice motion in the area is believed to be vertical(Whillans and Cassidy 1983). The presence of Thule-Baffinmoraines at the northern terminus of the blue ice tends tosupport the hypothesis that the area underlying the moraineis essentially stagnant and that ice arriving from the south ispiling up against it. Areas containing mineral deposits werefound within the moraine field to the north and east of theblue ice margin and also along the east margins of the blue iceitself. Subsequent X-ray diffraction analyses of these depositshave shown that they are composed predominantly of nah-colite (NaHCO3), trona [Na3(CO3)(HCO3) · 2H20], borax[Na2B405(OH)4 · 8H20], and a new hexagonal hydrous sulfatespecies. This paper reports the details of the borax occurrence,because it is the first known on the continent.

Selected coal-related ground-water data, Wasatch Plateau-Book Cliffs area, Utah

USGS Publications Warehouse

Sumsion, C.T.

1979-01-01

The Wasatch Plateau-Book Cliffs%area as used in this report consists of about 8,000 square miles in east-central Utah. The major geographic features included in the area are the Wasatch Plateau, Book Cliffs, San Rafael Swell, Price River basin, and a small part of the Green River basin (pl. 1). The area is defined by approximate drainage-divide boundaries in the Wasatch Plateau and Book Cliffs, by an arbitrary boundary on the south, and by the Utah-Colorado State line on the east.The Wasatch Plateau-Book Cliffs area includes all the operating coal mines in Utah in 1978. Annual coal production in the area is expected to increase from the current (1978) rate of about 8 million tons to as much as 30 million tons within the next 10 years (J. W. Moffitt, U.S. Geological Survey, oral commun., 1978). Ground water is an important source of water supply in the area. As mining increases and mining-related municipalities grow, many sources of ground-water supply may be subjected to increased demands and possibly degradation of chemical quality.Waddell, Vickers, Upton, and Contratto (1978) reported some ground- water data after a reconnaissance of part of the area. The purpose of this report, which was prepared in cooperation with the U.S. Bureau of Land Management, is to present a more detailed compilation of ground-water-related data that were collected and compiled during October 1976 to March 1978. The report is designed to make the data available in an orderly and usable form for local and regional water managers and other users of water data.

Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas

USGS Publications Warehouse

Sitzlar, M.A.; Mora, M.A.; Fleming, J.G.W.; Bazer, F.W.; Bickham, J.W.; Matson, C.W.

2009-01-01

Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies. ?? 2008 Springer Science+Business Media, LLC.

The White Cliffs of "Rover"

NASA Image and Video Library

2017-06-15

This image from NASA's Mars Reconnaissance Orbiter is reminiscent of the rugged and open terrain of a stark shore-line, perhaps of an island nation, such as the British Isles. A close-up in enhanced color produces a striking effect, giving the impression of a cloud-covered cliff edge with foamy waves crashing against it. The reality is that the surface of Mars is much dryer than our imaginations might want to suggest. This is only a tiny part of a much larger structure; an inverted crater -- a crater that has been infilled by material that is more resistant to erosion than the rocks around it -- surrounded by bluish basaltic dunes. The edge of these elevated light-toned deposits are degraded, irregular and cliff-forming. Dunes visible below the cliff, give the impression of an ocean surface, complete with foam capped waves crashing against the "shore line," demonstrating the abstract similarity between the nature of a turbulent ocean and a Martian dune field. Meridiani Planum has an overall smooth terrain, which starkly contrasts with the more common boulder- and crater-laden landscapes observed over much of the rest of Mars. This makes it relatively younger in character than many other areas of the planet. Meridiani is one of the Mars Exploration Rover landing sites, and, is known for its layers and sediments. The orbital detection of hematite was one of the main reasons for sending Opportunity to this area. Salt-bearing rocks -- also called sulphates -- were observed in the very first image from Opportunity, so perhaps it's apt that this HiRISE image reminds us of the turmoil and rugged beauty of a cliff-face, a coastline, being worn down by a relentless sea. https://photojournal.jpl.nasa.gov/catalog/PIA21760

Along Endurance Crater's Inner Wall (Left Eye)

NASA Technical Reports Server (NTRS)

2004-01-01

This view from the base of 'Burns Cliff' in the inner wall of 'Endurance Crater' combines several frames taken by Opportunity's navigation camera during the NASA rover's 280th martian day (Nov. 6, 2004). It is the left-eye member of a stereo pair, presented in a cylindrical-perspective projection with geometric seam correction. The cliff dominates the left and right portions of the image, while the central portion looks down into the crater. The 'U' shape of this mosaic results from the rover's tilt of about 30 degrees on the sloped ground below the cliff. Rover wheel tracks in the left half of the image show some of the slippage the rover experienced in making its way to this point. The site from which this image was taken has been designated as Opportunity's Site 37.

Flora of the Orange Cliffs of Utah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shultz, L.M.; Neely, E.E.; Tuhy, J.S.

1987-04-30

The Orange Cliffs area, an area rich in oil sands deposits and defined here as part of the Colorado Plateau floristic province, harbors approximately 209 species in 123 genera and 49 families. Because of the potential of exploitation of the oil sands deposits in the area, a species checklist was made and a discussion of physical and floristic aspects of the region is given here. The flora is compared statistically to the San Rafael Swell flora, which is also a subset of the Colorado Plateau. They define six vegetation types and three edaphic communities; these are described and mapped. Ofmore » eleven endemic plant species in the Orange Cliffs, three are local and rare. Sites for Astragalus nidularius, A. moencoppensis, and Xylorhiza glabriuscula var. linearifolia are discussed and mapped. 24 references, 3 figures, 3 tables.« less

Calving of Talyor Glacier, Dry Valleys, Antarctica

NASA Astrophysics Data System (ADS)

Carmichael, J. D.; Pettit, E. C.; Creager, K. C.; Hallet, B.

2007-12-01

Calving of tide-water glaciers has received considerable attention, with seismic arrays in Alaska, Greenland, and Antarctica devoted to their observation. In these environments, ice cliffs are directly coupled to oceanic temperatures. The land-based polar glaciers of the McMurdo Dry Valleys in Antarctica represent a simpler environment unaffected directly by water contact where other factors can be isolated. In particular, summer calving events of Taylor Glacier are observed to consist of precursory activity including crack growth, cliff overhang, and active seismicity at least 1 hour before collapse. We propose that collapse occurs only after a stress threshold has been crossed, evident from 'pre-calving' of ice from the cliff base 1-3 days prior to the major event. We provide photographic, seismic, and temperature data to illustrate the thermal and stress landscape for land-based calving of polar glaciers.

Marketing Analysis and Strategy for a Small Business in the Beekeeping Industry.

DTIC Science & Technology

1980-08-18

segment has opportunities associated with it that may be profitably 2Philip Kotler , "Marketing Management: Analysis, Planning, and Control," Prentice...I I I162 I I BIBLIOGRAPHY IB Abel, Derek and John Hammond. Strategic Market Planning. Englewood Cliffs, N.J.: Prentice- Hall, Inc., 1979. Kotler ... Philip . Marketing Management: Analysis, Planning, and Control. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1976. Ott, Hyman. Introduction to Statistical

Sea cliff erosion in the eastern part of the North Aegean coastline, Northern Greece.

PubMed

Xeidakis, George S; Delimani, P K; Skias, S G

2006-01-01

The coastal zone is an area where many human activities are taking place. Erosion of the coast obstructs, in various ways, these activities creating occasionally serious socioeconomic and environmental problems. In this paper the coastal erosion problems encountered in the eastern Greek part of the North Aegean Sea Coast, a stretch of about 51 km long adjacent to the city of Alexandroupolis, are discussed. Given the observed type and location of erosion and other sea-action phenomena, the coast under study is divided in two parts/stretches. The western stretch, where the city of Alexandroupolis is presently extending, presents, mainly, cliff erosion problems and retreat of the coastline, very serious in some sections; whereas, the eastern stretch (to the east of the city) exhibits deposition and progression seawards due to the abundance of sediments supplied by Evros river delta. A classification of the coastline according to its relief, geologic material, erosion characteristics and rate, slope failure phenomena as well as the wave energy potential, is presented together with suggestions for case-appropriate mitigation and protection measures regarding the coastal erosion problems. The paper is focusing on the cliff erosion phenomena, since varying in height coastal cliffs made of soft rocks, cover the major part of the investigated coastline (western stretch).

Community Structure and Survival of Tertiary Relict Thuja sutchuenensis (Cupressaceae) in the Subtropical Daba Mountains, Southwestern China

PubMed Central

Tang, Cindy Q.; Yang, Yongchuan; Ohsawa, Masahiko; Momohara, Arata; Yi, Si-Rong; Robertson, Kevin; Song, Kun; Zhang, Shi-Qiang; He, Long-Yuan

2015-01-01

A rare coniferous Tertiary relict tree species, Thuja sutchuenensis Franch, has survived in the Daba Mountains of southwestern China. It was almost eliminated by logging during the past century. We measured size and age structures and interpreted regeneration dynamics of stands of the species in a variety of topographic contexts and community associations. Forest communities containing T. sutchuenensis were of three types: (1) the Thuja community dominated by T. sutchuenensis, growing on cliffs; (2) the Thuja-Quercus-Cyclobalanopsis community dominated by T. sutchuenensis, Quercus engleriana and Cyclobalanopsis oxyodon, along with Fagus engleriana and Carpinus fargesiana, on steep slopes; (3) the Thuja-Tsuga-Quercus community dominated by T. sutchuenensis, Tsuga chinensis, and Quercus spinosa, on crest ridges. The established seedlings/saplings were found in limestone crevices, on scarred cliff-faces, cliff-edges, fallen logs, canopy gaps and forest margins. The radial growth rate was 0.5-1.1 mm per year. Its growth forms were distorted. It had strong sprouting ability after disturbances. The T. sutchuenensis population thrives on cliffs where there is little competition from other species because of harsh conditions and rockslide disturbances. It is shade-intolerant but stress-tolerant. Its regeneration has depended on natural disturbances. PMID:25928845

Hybrid digital-analog video transmission in wireless multicast and multiple-input multiple-output system

NASA Astrophysics Data System (ADS)

Liu, Yu; Lin, Xiaocheng; Fan, Nianfei; Zhang, Lin

2016-01-01

Wireless video multicast has become one of the key technologies in wireless applications. But the main challenge of conventional wireless video multicast, i.e., the cliff effect, remains unsolved. To overcome the cliff effect, a hybrid digital-analog (HDA) video transmission framework based on SoftCast, which transmits the digital bitstream with the quantization residuals, is proposed. With an effective power allocation algorithm and appropriate parameter settings, the residual gains can be maximized; meanwhile, the digital bitstream can assure transmission of a basic video to the multicast receiver group. In the multiple-input multiple-output (MIMO) system, since nonuniform noise interference on different antennas can be regarded as the cliff effect problem, ParCast, which is a variation of SoftCast, is also applied to video transmission to solve it. The HDA scheme with corresponding power allocation algorithms is also applied to improve video performance. Simulations show that the proposed HDA scheme can overcome the cliff effect completely with the transmission of residuals. What is more, it outperforms the compared WSVC scheme by more than 2 dB when transmitting under the same bandwidth, and it can further improve performance by nearly 8 dB in MIMO when compared with the ParCast scheme.

Herbicide treatment of invasive Vinca major growing with endangered Galium buxifolium, an island endemic

USGS Publications Warehouse

McEachern, Kathryn; Chess, Katie; Flagg, Karen; Niessen, Ken; Owen,; Thompson,

2010-01-01

Galium buxifolium E. Greene [Rubiaceae] (sea-cliff bedstraw) is a small shrub restricted to San Miguel and Santa Cruz Islands, in the California Channel Islands. Almost all of the 26 known populations grow on vertical north-facing sea cliffs in native scrub, sandwiched between the sea below and non-native annual grasslands on the terraces above. A notable exception is a popula?tion at Pelican Bay on Santa Cruz Island, growing on the cliff and on thin terrace soils above the cliff in a stand of coastal bluff scrub that is recovering from more than a century of sheep grazing (Figure 1). Ironically, this stand is near the location of the historic Eaton Resort, a charismatic inn frequented by Hollywood glitterati in the early 1900s. Several landscape ornamentals planted there persist today in the area of the Galium population. Italian stone pine (Pinus pinaea) and eucalyptus (Eucalyptus spp.) tower over the site while the invasive groundcover Vinca major L. [Apocynaceae] (greater periwinkle) forms dense mats at the cliff edge that are spreading into the developing native plant stand. Wherever the Galium is found it is intermixed with other native scrub plants in dense communities on moist ocean bluffs. Historic notes and herbarium collections indicate that it may have been more widespread on nearshore terraces adjacent to sea-cliff populations before conversion to grassland. Since Pelican Bay is the only site that we know of where Galium is spreading onto the nearby terrace, we wanted to know whether the Vinca posed a roadblock to upslope population expansion. In 2005 we mapped Vinca and Galium at the site. We also measured Galium individuals to see where the smaller, younger plants were to better understand where the population is expanding. We observed that 1) both the Galium and the Vinca appear to be spreading from the cliff face upslope onto a series of rock outcrops, stone walls and benches, 2) the native scrub community is recovering at the site and 3) the Vinca appears to be moving into the native scrub where it overtops small plants, including those Galium in the smallest size classes. This observed pattern of Vinca displacement of native vegetation has been noted in other places, where it is treated as an invasive weed. We concluded that Vinca may pose a threat to the expansion of both the native scrub and the Galium population that it supports. Therefore, we worked with the US Fish and Wildlife Service and others to develop a research project investigating 1) best techniques for killing Vinca within the boundaries of an endangered plant population and 2) demographic response of Galium to the treatment. Our intent is to push Vinca back to the vertical cliff face to give the natives a chance to establish a vigorous stand. Our conservation goal is to encourage natural establishment of new Galium plants on the terrace along with expansion of the native coastal bluff scrub and Galium population. Our immediate treatment objective is to reduce live Vinca cover by 90 % on the accessible upslope portions of the habitat. Our recovery objective is no net loss of Galium plants 2006-2016.

Rockfall monitoring of a poorly consolidated marly sandstone cliff by TLS and IR thermography

NASA Astrophysics Data System (ADS)

Lefeuvre, Caroline; Guérin, Antoine; Carrea, Dario; Derron, Marc-Henri; Jaboyedoff, Michel

2017-04-01

The study area of La Cornalle (Vaud, Switzerland) is a 40 m high south-west facing cliff which is also part of a larger landslide (Bersier 1975 ; Parriaux, 1998). The cliff is formed by an alternation of marls and sandstones. The thicknesses of sandstone layers range from 0.5 to 4 meters. The rockfall activity of this cliff is high, with an average of one event per day. The aim of this study is to better understand the links between rockfall activity, cliff's structures, and weather and thermal conditions. The 3D surface evolution of the Cornalle cliff is monitored approximately every month since September 2012 using a Terrestrial Laser Scanning (TLS) data in order to get a monthly inventory of rockfall events. Since November 2013, a weather station located 150 meters away from the cliff collects data such as temperature, humidity, atmospheric pressure, rain and solar radiation every 15 minutes. Furthermore, we also fixed a thermic probe in the sandstone at 10 cm deep which measures temperature every 10 minutes. A detailed analysis has been performed during a short period (01/29/2016-04/08/2016) and pointed out a correlation between daily rainfall and rockfall. We found that a fall occurred the day or the day after a cumulative daily rainfall of at least 10 mm/day.In parallel to this monthly monitoring, the northwest part of La Cornalle cliff (the most active part) was monitored for 24 consecutive hours in July 2016 (from 12:30 to 12:30) using infrared thermography and crackmeters with a precision of 0.01mm. We collected a series of thermal pictures every 20 minutes, and measured the opening of a crack in sandstone layers every hour. We observed that marls are more affected by external changes of temperature than sandstones. Their surface temperature rises (resp. falls) more with an increase (resp. decrease) of external temperature than sandstones. Crackmeters measured an opening of the crack with an increase of the rock temperature and the opposite displacement (crack closing) happened with a decrease of temperature. The maximal amplitude of cumulated displacements measured is 0.15 mm. In terms of uncertainty, note that until 30% of the measured displacement can be related to instrument thermal dilatation. Finally, a multilayer model of daily thermal variations, including air temperature, solar radiation, rock temperature and thermal imaging is in development to assess the effect of temperature on unstable blocks and fracture opening, as demonstrated recently by Collins and Stock (2016). References Bersier A., Blanc P., Weidmann M. (1975). Le glissement de terrain de La Cornalle-Les Luges (Epesses, Vaud, Suisse). Bulletin de la société vaudoise des sciences naturelles, 72, fasc. 4 Collins B. D., Stock G. M. (2016). Rockfall triggering by cyclic thermal stressing of exfoliation fractures. Nature Geoscience. Published online March 28, 2016. Doi 10.1038/NGEO2686 Parriaux A. (1998): Glissement de la Cornalle: Bull. Géol. appl.,3 (1), 49-56

Rock billboards on the basaltic cliff along the Route 66 ...

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

Rock billboards on the basaltic cliff along the Route 66 alignment, ca. 1926. The sign on the left is for "La Bajada Service Shop" (faint "da" visible), "Santa Fe Camp" in the center, and a petroglyph at far right. View facing northwest. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

Renewed uplift of the Central Andes Forearc revealed by coastal evolution during the Quaternary

NASA Astrophysics Data System (ADS)

Regard, Vincent; Saillard, Marianne; Martinod, Joseph; Audin, Laurence; Carretier, Sébastien; Pedoja, Kevin; Riquelme, Rodrigo; Paredes, Paola; Hérail, Gérard

2010-08-01

Most of the Pacific coast of the Central Andes, between 15°S and 30°S, display a wide (a couple of kilometres) planar feature, gently dipping oceanwards and backed by a cliff. This morphology, usually of marine origin, is called rasa, and argues for a recent and spatially continuous uplift of the margin over the 1500-km-long coastal region we describe. The cliff foot is found at a similar elevation (˜ 110 m amsl) all over the studied area, with the exception of peninsulas such as the Mejillones Peninsula. The compilation of published chronological data and the extrapolation of re-appraised uplift rates provide evidence for a common cliff foot age of around 400 ka (i.e., Marine Isotopic Stage MIS 11). This, together with other geological constraints, indicates a Quaternary renewal of uplift in the Central Andes Forearc after a late Pliocene quiescence or subsidence.

Wave Shape and Impact Pressure Measurements at a Rock Coast Cliff

NASA Astrophysics Data System (ADS)

Varley, S. J.; Rosser, N. J.; Brain, M.; Vann Jones, E. C.

2016-02-01

Rock coast research focuses largely on wave behaviour across beaches and shore platforms but rarely considers direct wave interaction with cliffs. Hydraulic action is one of the most important drivers of erosion along rock coasts. The magnitude of wave impact pressure has been shown by numerical and laboratory studies to be related to the wave shape. In deep water, a structure is only subjected to the hydrostatic pressure due to the oscillating clapotis. Dynamic pressures, related to the wave celerity, are exerted in shallower water when the wave is breaking at the point of impact; very high magnitude, short duration shock pressures are theorised to occur when the approaching wavefront is vertical. As such, wave shape may directly influence the potential of the impact to weaken rock and cause erosion. Measurements of impact pressure at coastal cliffs are limited, and the occurrence and influence of this phenomenon is currently poorly constrained. To address this, we have undertaken a field monitoring study on the magnitude and vertical distribution of wave impact pressures at the rocky, macro-tidal coastline of Staithes, North Yorkshire, UK. A series of piezo-resistive pressure transducers and a camera were installed at the base of the cliff during low tide. Transducers were deployed vertically up the cliff face and aligned shore-normal to capture the variation in static and dynamic pressure with height during a full spring tidal cycle. Five minute bursts of 5 kHz pressure readings and 4 Hz wave imaging were sampled every 30 minutes for six hours during high tide. Pressure measurements were then compensated for temperature and combined with wave imaging to produce a pressure time series and qualitative wave shape category for each wave impact. Results indicate the presence of a non-linear relationship between pressure impact magnitude, the occurrence of shock pressures, wave shape and tidal stage, and suggest that breaker type on impact (and controls thereof) may be fundamental in dictating the effectiveness of hydraulic action in eroding rock coast cliffs. Our findings demonstrate the sensitivity of wave loading to changes in water depth and, hence, projected sea-level rise. This research leads directly into a wider project investigating the role of wave shape as a key control on marine forcing of erosion.

Cliffs versus plains: Can ROSINA/COPS and OSIRIS data of comet 67P/Churyumov-Gerasimenko in autumn 2014 constrain inhomogeneous outgassing?

NASA Astrophysics Data System (ADS)

Marschall, R.; Mottola, S.; Su, C. C.; Liao, Y.; Rubin, M.; Wu, J. S.; Thomas, N.; Altwegg, K.; Sierks, H.; Ip, W.-H.; Keller, H. U.; Knollenberg, J.; Kührt, E.; Lai, I. L.; Skorov, Y.; Jorda, L.; Preusker, F.; Scholten, F.; Vincent, J.-B.; Osiris Team; Rosina Team

2017-09-01

Context. This paper describes the modelling of gas and dust data acquired in the period August to October 2014 from the European Space Agency's Rosetta spacecraft when it was in close proximity to the nucleus of comet 67P/Churyumov-Gerasimenko. Aims: With our 3D gas and dust comae models this work attempts to test the hypothesis that cliff activity on comet 67P/Churyumov-Gerasimenko can solely account for the local gas density data observed by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) and the dust brightnesses seen by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) in the considered time span. Methods: The model uses a previously developed shape model of the nucleus. From this, the water sublimation rates and gas temperatures at the surface are computed. The gas expansion is modelled with a 3D Direct Simulation Monte Carlo algorithm. A dust drag algorithm is then used to compute dust volume number densities in the coma, which are then converted to brightnesses using Mie theory and a line-of-sight integration. Furthermore we have studied the impact of topographic re-radiation on the models. Results: We show that gas activity from only cliff areas produces a fit to the ROSINA/COPS data that is as statistically good as a purely insolation-driven model. In contrast, pure cliff activity does not reproduce the dust brightness observed by OSIRIS and can thus be ruled out. On the other hand, gas activity from the Hapi region in addition to cliff activity produces a statistically better fit to the ROSINA/COPS data than purely insolation-driven outgassing and also fits the OSIRIS observations rather well. We found that topographic re-radiation does not contribute significantly to the sublimation behaviour of H2O but plays an important role in how the gas flux interacts with the irregular shape of the nucleus. Conclusions: We demonstrate that fits to the observations are non-unique. We can conclude however that gas and dust activity from cliffs and the Hapi region are consistent with the ROSINA/COPS and OSIRIS data sets for the considered time span and are thus a plausible solution. Models with activity from low gravitational slopes alone provide a statistically inferior solution.

Water and processes of degradation in the Martian landscape.

NASA Technical Reports Server (NTRS)

Milton, D. J.

1973-01-01

Some large channels on Mars show features, notably bars and braiding, that indicate an origin by the action of running water. Smaller channels on steep slopes may have been produced by runoff of precipitation. Dendritic canyon systems suggest ground water sapping, which may have been an effective agent in cliff retreat generally. Extensive plains developed as cliffs retreated and, although modified by later wind action, may be regarded as relict landforms from a fluvial stage of Martian history.

Occurrence of morphological and anatomical adaptive traits in young and adult plants of the rare Mediterranean cliff species Primula palinuri Petagna.

PubMed

De Micco, Veronica; Aronne, Giovanna

2012-01-01

Cliffs worldwide are known to be reservoirs of relict biodiversity. Despite the presence of harsh abiotic conditions, large endemic floras live in such environments. Primula palinuri Petagna is a rare endemic plant species, surviving on cliff sites along a few kilometres of the Tyrrhenian coast in southern Italy. This species is declared at risk of extinction due to human impact on the coastal areas in question. Population surveys have shown that most of the plants are old individuals, while seedlings and plants at early stages of development are rare. We followed the growth of P. palinuri plants from seed germination to the adult phase and analysed the morphoanatomical traits of plants at all stages of development. Our results showed that the pressure of cliff environmental factors has been selected for seasonal habitus and structural adaptive traits in this species. The main morphoanatomical modifications are suberized cell layers and accumulation of phenolic compounds in cell structures. These features are strictly related to regulation of water uptake and storage as well as defence from predation. However, we found them well established only in adult plants and not in juvenile individuals. These findings contribute to explain the rare recruitment of the present relict populations, identifying some of the biological traits which result in species vulnerability.

Influence of El Niño–Southern Oscillation (ENSO) events on the evolution of central California's shoreline

USGS Publications Warehouse

Storlazzi, Curt D.; Griggs, Gary B.

2000-01-01

Significant sea-cliff erosion and storm damage occurred along the central coast of California during the 1982–1983 and 1997–1998 El Niño winters. This generated interest among scientists and land-use planners in how historic El Niño–Southern Oscillation (ENSO) winters have affected the coastal climate of central California. A relative ENSO intensity index based on oceanographic and meteorologic data defines the timing and magnitude of ENSO events over the past century. The index suggests that five higher intensity (relative values 4–6) and 17 lower intensity (relative values 1–3) ENSO events took place between 1910 and 1995. The ENSO intensity index correlates with fluctuations in the time series of cyclone activity, precipitation, detrended sea level, wave height, sea-surface temperature, and sea-level barometric pressure. Wave height, sea level, and precipitation, which are the primary external forcing parameters in sea-cliff erosion, increase nonlinearly with increasing relative ENSO event intensity. The number of storms that caused coastal erosion or storm damage and the historic occurrence of large-scale sea-cliff erosion along the central coast also increase nonlinearly with increasing relative event intensity. These correlations and the frequency distribution of relative ENSO event intensities indicate that moderate- to high-intensity ENSO events cause the most sea-cliff erosion and shoreline recession over the course of a century.

Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points

NASA Astrophysics Data System (ADS)

Dewez, T. J. B.

2014-05-01

Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.

Holocene evolution of coastal chalk cliffs in Normandy (NW France) as evidenced by onshore-offshore high resolution geomorphology

NASA Astrophysics Data System (ADS)

Duguet, Timothée; Duperret, Anne; Costa, Stéphane; Regard, Vincent; Maillet, Grégoire

2017-04-01

Key words: erosion, rocky coast, cliffs, shore platform, watersheds, cosmogenic dating The chalk cliffs coastline extends to 120 km long in Normandy. It suffers from high erosion rates with a mean of about 0.15 m/y. The shore platforms extending from the cliff base to the sea, keep structural marks of the cliff erosion during long periods, i.e. the Holocene. Therefore it is essential to take an active interest in their morphology and their evolution to better understand cliff erosion timing. A land-sea Digital Elevation Model (DEM) has been produced for Mesnil-Val and Criel-sur-Mer sites (Seine Maritime), with the merge of topographic data (RGE alti, IGN) and shallow bathymetric data from three oceanographic Cruises, CROCOLIT-1 and 3 (Duperret, 2013) and SPLASHALIOT-2 (Maillet, 2014). Valleys that have more or less incised Turonian-Coniacian chalk cliffs occupy the landward part of study sites. The N130E V-shaped incised Mesnil-Val dry valley is elevated at 29 m high above the shore platform level, whereas the N175E Criel-sur-Mer flat valley, extending on 700 m wide and occupied by the Yères river, is directly connected to the shore platform. Offshore, the shore platform morphology varies from Criel-sur-Mer (North) to Mesnil-Val (South). Northern part of the study site is characterized by 1 km wide shore platform made of an overlay of flat steps controlled by normal faults. Southern part highlights a shore platform with a seaward edge located at about 500 m from the cliff face and strictly parallel oriented to the present-day coastline over a minimum distance of 5 km, without fracture control. The shore platform seaward edge is more or less steep and is always localized below the limit of the lowest tide level. Its origin could be related to the in-depth waves influence or to a past sea level stagnation. We aim to identify the origin of this seaward edge, using cosmogenic 10Be dating in order to develop a chalky shore platform evolution model. It is necessary to take into account detailed rock lithology and rock resistance, large and small-scale structural deformation and fractures occurrences versus the sea level variations during the Holocene. A numeric watersheds analysis has been performed inland to highlight the morphometric properties and the maturity status of each quaternary valley. They appear to be immature, even if their downstream areas demonstrate slopes varying between 0.5 and 2°. Paleo-rivers stopped to incise the chalk before reaching their equilibrium level base. We thus consider that the equilibrium point where the paleo-rivers and the past sea level were connected is located on the shore platform i.e. today located offshore. Therefore we project offshore the V-shaped valley base level, using Hack's law to estimate the paleo-coastline location. It will be correlated to the sea level fluctuations from the last interglacial period and to the Holocene shoreline recession rates known from the 10Be cosmogenic dating. References DUPERRET Anne (2013) CROCOLIT_LEG1 cruise, RV Haliotis, http://dx.doi.org/10.17600/13120080 DUPERRET Anne (2013) CROCOLIT_LEG3 cruise, RV Haliotis, http://dx.doi.org/10.17600/13120100 MAILLET Grégoire (2014) SPLASHALIOT-2 cruise, RV Haliotis, http://dx.doi.org/10.17600/14011800

UAS-enabled assessment of geohazards on coastal cliffs at Dawlish, UK

NASA Astrophysics Data System (ADS)

Dabson, Oliver; Bellis, Alex; Moore, Roger

2017-04-01

The last few years have seen the widespread availability of Unmanned Aerial Systems (UAS) - remotely-operated aerial vehicles which are being developed for use in a variety of commercial and recreational applications. The combination of these systems with off-the-shelf digital cameras and image processing software using well-established Structure-from-Motion techniques can produce 3D models with centimetric resolution and accuracy for sites covering several square kilometres. The geo-engineering community has been exploring the use of these systems for collecting data in environments where it may be hazardous or impossible to use more conventional means. Advantages of deployment of UAS have already been identified, which include cost, ease of survey in terms of access, rapid acquisition of data and repeatability, and reduction in the number of personnel directly exposed to geological hazards during site visits. As such, the technology continues to be an exciting tool to explore. At Dawlish, UK, weathering and erosion of the sea cliffs has resulted in numerous serious slope failures, with some notable examples over the last decade that were the focus of national media attention. This poses significant risk to Network Rail's Western Route: a stretch of rail built by Brunel in 1840, situated at the foot of these cliffs. CH2M was commissioned by Network Rail to explore options for improving the resilience of the line, but access constraints meant that sections of the cliff were difficult or impossible to access during site visits. As such, this paper describes the use of UAS to capture and assess this system. We find that the UAS technology offers new insight to the site, allowing for finer-resolution mapping and interpretation of sub-vertical cliffs. This has been an important study within a wider assessment of the site, and the survey has supplemented recommendations on how to best manage the coastal asset in order to ensure the operation of a safe and reliable railway.

Terrestrial ages of ordinary chondrites from the lewis cliff stranding area, East Antarctica

NASA Astrophysics Data System (ADS)

Welten, K. C.; Lindner, L.; Alderliesten, C.; van der Borg, K.

1999-07-01

We determined terrestrial ages of ordinary chondrites from the Lewis Cliff stranding area, East Antarctica, on the basis of the concentrations of cosmogenic 10Be (t1/2 = 1.51 Ma), 26Al (t1/2 = 0.705 Ma) and 36Cl (t1/2 = 0.301 Ma). After an initial 26Al -ray survey of 91 meteorites suggested that many have terrestrial ages larger than 0.1 Ma, we selected 62 meteorites for 10Be and 26Al measurements by accelerator mass spectrometry (AMS) and measured 36Cl in twelve of those. Low terrestrial ages (<0.1 Ma) were found for about 60% of the meteorites, whereas all others have ages between 0.1 and 0.5 Ma, except for one exceptional age of >2 Ma (Welten et al., 1997). Our major conclusions are: (1) The Lewis Cliff H-chondrites show similar ages as those from the Allan Hills Ice-fields, but the L-chondrites are about a factor of two younger than those from Allan Hills, which indicates that Lewis Cliff is a younger stranding area. (2) The terrestrial age distributions at different parts of the Lewis Cliff stranding area generally agree with simple meteorite concentration models, although differences in weathering rate may also play a role. (3) We confirm that meteorites with natural thermoluminescence (TL) levels >80 krad are associated with low terrestrial ages (Benoit et al., 1992), but conclude that natural TL levels <80 krad can not be used to calculate the terrestrial age of a meteorite. Natural TL levels do seem useful to estimate relative terrestrial ages of large groups of meteorites and to determine differences in surface exposure age of paired meteorite fragments. (4) Of the 62 meteorites measured with AMS, 31 were assigned to eleven different pairing groups, mainly on the basis of their cosmogenic nuclide record. The meteorites are estimated to represent between 42 and 52 distinct falls.

Akpatok Island

NASA Image and Video Library

2017-12-08

January 1st, 2001: Description: Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. Source: Landsat 7 To learn more about the Landsat satellite go to: landsat.gsfc.nasa.gov/

GEOLOGICAL-GEOMORPHOLOGICAL ANALYSIS OF THE REGION OF GUADALAJARA, MEXICO AND ITS RELATION WITH SUBSIDENCE HAZARDS

NASA Astrophysics Data System (ADS)

Suarez-Plascencia, C.; Delgado-Argote, L. A.; Nunez-Cornu, F. J.

2009-12-01

The Metropolitan Area of Guadalajara (MAG) was built over pumice deposits generated during Quaternary activity in the Sierra la Primavera, that covered a thick sequence of basaltic, dacitic, rhyolitic lava flows, ignimbrites and fluvial-lacustrine deposits. The most complete stratigraphic section is observed in different sections of the Rio Grande de Santiago cliff, located north of the city. Five distinctive geoforms were identified: 1) the cliff of the Rio Grande de Santiago (CRGS) is a tectonic erosive depression with average depth of 500 m and 3.5 km width. Structurally, in the San Gaspar zone, south of the union of Verde river with Santiago river, we identified normal faults with left-lateral motion and oriented 191°/89° on basaltic lavas. In the Colimilla dam, 1297 meters above sea level, we observed lateral faulting with normal component (267°/81°) where jumps as high as 30 m were observed. Lava flows are sheared parallel to the Verde river. In the Puente Arcediano zone, where the base of the sequence is apparent, faults have a dominant orientation of 188°/75° on andesitic flows, whereas on pumice ignimbrites they show a shearing with a direction of 92°/84° parallel to the Verde river. 2) The Sierra la Primavera, to the southwest of MAG is a caldera formed by a series of domes, flows, and pyroclastic deposits with rhyolitic composition. 3) The southern Guadalajara volcanic chain system, which is formed by several volcanic cones and flows of basaltic-andesitic composition and Plio-Pleistocene age, oriented NW-SE, developed over the San Gaspar ignimbrite (4.8 m.a.). 4) Los Colomos and Alcalde-Barranquitas cliff system, which form dendrite networks developed on pumice deposits, where most of the cliffs were deep and narrow. The origin of the cliffs might be associated with observed faults or fracture zones in the CRGS. 5) Wavy plains of Atemajac and Tesistán valleys, which are characterized by hills and wide plains. The system of cliffs controlled the growth of the MAG on its N, W, and NW sectors until the 1940 decade. Starting the 1950 decade, however, urban developers began to slowly modify the relief units and to build landfills on los Colomos and Alcalde Barranquitas cliffs as well as to build one and two-storey houses. During the mid 1980 decade there began to appear reports of affectation of variable magnitude caused by sinking of buildings and infrastructures on this area of the city. These problems have forced the different municipal governments and private owners to pump large funds for the mitigation and prevention of damage, but the sinking is recurrent at the time of this writing. More than 1,100 sites of sinking were observed and related directly to areas where the relief has been modified for urban use.

Geology of Isla de Mona, Puerto Rico

USGS Publications Warehouse

Frank, E.F.; Wicks, Carol M.; Mylroie, J.; Troester, J.; Alexander, E.C.; Carew, J.L.

1998-01-01

Isla de Mona is a carbonate island located in the Mona Passage 68 km west of Puerto Rico. The tectonically uplifted island is 12 km by 5 km, with an area of 55 km2, and forms a raised flat-topped platform or meseta. The meseta tilts gently to the south and is bounded by near vertical cliffs on all sides. These cliffs rise from 80 m above sea level on the north to 20 m above the sea on the southern coast. Along the southwestern and western side of the island a three- to six-meter-high Pleistocene fossil reef abuts the base of the cliff to form a narrow coastal plain. The meseta itself consists of two Mio-Pliocene carbonate units, the lower Isla de Mona Dolomite and the upper Lirio Limestone. Numerous karst features, including a series of flank margin caves primarily developed at the Lirio Limestone/Isla de Mona Dolomite contact, literally ring the periphery of the island.

Asymmetric crack propagation near waterfall cliff and its influence on the waterfall lip shape

NASA Astrophysics Data System (ADS)

Vastola, G.

2011-11-01

By means of Finite Element Method (FEM) calculations and fatigue fracture mechanics analysis, we show that crack propagation in bedrocks close to the waterfall cliff is preferential towards the cliff face rather than upstream the river. Based on this effect, we derive the corresponding expression for the velocity of recession vr of the waterfall lip, and find that vr has a quadratic dependence on the hydrostatic pressure. Quantitatively, this erosion mechanism generates recession rates of the order of ~cm-dm/y, consistent with the recession rates of well-known waterfalls. We enclose our expression for vr into a growth model to investigate the time evolution of a waterfall lip subject to this erosional mechanism. Because of the dependence on hydrostatic pressure, the shape of the waterfall is influenced by the transverse profile of the river that generates the waterfall. If the river has a transverse concavity, the waterfall evolves a curved shape. Evolution for the case of meanders with asymmetric transverse profile is also given.

Influence in times of crisis: how social and financial resources affect men's and women's evaluations of glass-cliff positions.

PubMed

Rink, Floor; Ryan, Michelle K; Stoker, Janka I

2012-01-01

In two scenario-based studies, we found that women and men evaluate glass-cliff positions (i.e., precarious leadership positions at organizations in crisis) differently depending on the social and financial resources available. Female and male participants evaluated a hypothetical leadership position in which they would have both social and financial resources, financial resources but no social resources, or social resources but no financial resources. Women evaluated the position without social resources most negatively, whereas men evaluated the position without financial resources most negatively. In study 2, we found that women and men considered different issues when evaluating these leadership positions. Women's evaluations and expected levels of influence as leaders depended on the degree to which they expected to be accepted by subordinates. In contrast, men's evaluations and expected levels of acceptance by subordinates depended on the degree to which they expected to be influential in the position. Our findings have implications for the understanding of the glass-cliff phenomenon and gendered leadership stereotypes.

Recapture Heterogeneity in Cliff Swallows: Increased Exposure to Mist Nets Leads to Net Avoidance

PubMed Central

Roche, Erin A.; Brown, Charles R.; Brown, Mary Bomberger; Lear, Kristen M.

2013-01-01

Ecologists often use mark-recapture to estimate demographic variables such as abundance, growth rate, or survival for samples of wild animal populations. A common assumption underlying mark-recapture is that all animals have an equal probability of detection, and failure to meet or correct for this assumption–as when certain members of the population are either easier or more difficult to capture than other animals–can lead to biased and inaccurate demographic estimates. We built within-year and among-years Cormack-Jolly-Seber recaptures-only models to identify causes of capture heterogeneity for a population of colonially nesting cliff swallows (Petrochelidon pyrrhonota) caught using mist-netting as a part of a 20-year mark-recapture study in southwestern Nebraska, U.S.A. Daily detection of cliff swallows caught in stationary mist nets at their colony sites declined as the birds got older and as the frequency of netting at a site within a season increased. Experienced birds’ avoidance of the net could be countered by sudden disturbances that startled them into a net, such as when we dropped a net over the side of a bridge or flushed nesting cliff swallows into a stationary net positioned at a colony entrance. Our results support the widely held, but seldom tested, belief that birds learn to avoid stationary mist nets over time, but also show that modifications of traditional field methods can reduce this source of recapture heterogeneity. PMID:23472138

Comparison of Cliff-Lorimer-Based Methods of Scanning Transmission Electron Microscopy (STEM) Quantitative X-Ray Microanalysis for Application to Silicon Oxycarbides Thin Films.

PubMed

Parisini, Andrea; Frabboni, Stefano; Gazzadi, Gian Carlo; Rosa, Rodolfo; Armigliato, Aldo

2018-06-01

In this work, we compare the results of different Cliff-Lorimer (Cliff & Lorimer 1975) based methods in the case of a quantitative energy dispersive spectrometry investigation of light elements in ternary C-O-Si thin films. To determine the Cliff-Lorimer (C-L) k-factors, we fabricated, by focused ion beam, a standard consisting of a wedge lamella with a truncated tip, composed of two parallel SiO2 and 4H-SiC stripes. In 4H-SiC, it was not possible to obtain reliable k-factors from standard extrapolation methods owing to the strong CK-photon absorption. To overcome this problem, an extrapolation method exploiting the shape of the truncated tip of the lamella is proposed herein. The k-factors thus determined, were then used in an application of the C-L quantification procedure to a defect found at the SiO2/4H-SiC interface in the channel region of a metal-oxide field-effect-transistor device. As in this procedure, the sample thickness is required, a method to determine this quantity from the averaged and normalized scanning transmission electron microscopy intensity is also detailed. Monte Carlo simulations were used to investigate the discrepancy between experimental and theoretical k-factors and to bridge the gap between the k-factor and the Watanabe and Williams ζ-factor methods (Watanabe & Williams, 2006).

Investigating Mars: Candor Chasma

NASA Image and Video Library

2018-01-19

This image shows part of eastern Candor Chasma. At the top of the image is the steep cliff between the upper surface elevation and the depths of Candor Chasma. The bottom of the image is the cliff side of a large mesa. The two cliff faces have very different appearances. The cliff face between the top of the canyon and the bottom is likely layers of volcanic flows from the nearby Tharsis volcanoes. The mesa, however, is probably layers of sediments deposited in the canyon from wind, water and gravity driven erosion and deposition. These layered materials are much more easily eroded than the solid rock of the canyon sides. There is a landslide that originate from the northern cliff face and ran out into the canyon floor, visible as the lobate "tongue" at the right near the center of the image. Candor Chasma is one of the largest canyons that make up Valles Marineris. It is approximately 810 km long (503 miles) and has is divided into two regions - eastern and western Candor. Candor is located south of Ophir Chasma and north of Melas Chasma. The border with Melas Chasma contains many large landslide deposits. The floor of Candor Chasma includes a variety of landforms, including layered deposits, dunes, landslide deposits and steep sided cliffs and mesas. Many forms of erosion have shaped Chandor Chasma. There is evidence of wind and water erosion, as well as significant gravity driven mass wasting (landslides). The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions. Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all. For the next several months the image of the day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images! Orbit Number: 36232 Latitude: -6.78692 Longitude: 292.732 Instrument: VIS Captured: 2010-02-13 14:46 https://photojournal.jpl.nasa.gov/catalog/PIA22170

Kasei Valles

NASA Image and Video Library

2015-10-14

Kasei Valles is a valley system was likely carved by some combination of flowing water and lava. In some areas, erosion formed cliffs along the flow path resulting in water or lava falls. In some areas, erosion formed cliffs along the flow path resulting in water or lava falls. The flowing liquid is gone but the channels and "dry falls" remain. Since its formation, Kasei Valles has suffered impacts-resulting in craters-and has been mantled in dust, sand, and fine gravel as evidenced by the rippled textures. http://photojournal.jpl.nasa.gov/catalog/PIA20004

Akpatok Island

NASA Technical Reports Server (NTRS)

2002-01-01

Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

Robotic End Effectors for Hard-Rock Climbing

NASA Technical Reports Server (NTRS)

Kennedy, Brett; Leger, Patrick

2004-01-01

Special-purpose robot hands (end effectors) now under development are intended to enable robots to traverse cliffs much as human climbers do. Potential applications for robots having this capability include scientific exploration (both on Earth and other rocky bodies in space), military reconnaissance, and outdoor search and rescue operations. Until now, enabling robots to traverse cliffs has been considered too difficult a task because of the perceived need of prohibitively sophisticated planning algorithms as well as end effectors as dexterous as human hands. The present end effectors are being designed to enable robots to attach themselves to typical rock-face features with less planning and simpler end effectors. This advance is based on the emulation of the equipment used by human climbers rather than the emulation of the human hand. Climbing-aid equipment, specifically cams, aid hooks, and cam hooks, are used by sport climbers when a quick ascent of a cliff is desired (see Figure 1). Currently two different end-effector designs have been created. The first, denoted the simple hook emulator, consists of three "fingers" arranged around a central "palm." Each finger emulates the function of a particular type of climbing hook (aid hook, wide cam hook, and a narrow cam hook). These fingers are connected to the palm via a mechanical linkage actuated with a leadscrew/nut. This mechanism allows the fingers to be extended or retracted. The second design, denoted the advanced hook emulator (see Figure 2), shares these features, but it incorporates an aid hook and a cam hook into each finger. The spring-loading of the aid hook allows the passive selection of the type of hook used. The end effectors can be used in several different modes. In the aid-hook mode, the aid hook on one of the fingers locks onto a horizontal ledge while the other two fingers act to stabilize the end effector against the cliff face. In the cam-hook mode, the broad, flat tip of the cam hook is inserted into a non-horizontal crack in the cliff face. A subsequent transfer of weight onto the end effector causes the tip to rotate within the crack, creating a passive, self-locking action of the hook relative to the crack. In the advanced hook emulator, the aid hook is pushed into its retracted position by contact with the cliff face as the cam hook tip is inserted into the crack. When a cliff face contains relatively large pockets or cracks, another type of passive self-locking can be used. Emulating the function of the piece of climbing equipment called a "cam" (note: not the same as a "cam hook"; see Figure 1), the fingers can be fully retracted and the entire end effector inserted into the feature. The fingers are then extended as far as the feature allows. Any weight then transferred to the end effector will tend to extend the fingers further due to frictional force, passively increasing the grip on the feature. In addition to the climbing modes, these end effectors can be used to walk on (either on the palm or the fingertips) and to grasp objects by fully extending the fingers.

Application of topography survey on the green sea turtle (Chelonia mydas) conservation

NASA Astrophysics Data System (ADS)

Fan, Yuan-Yu; Lo, Liu-Chih; Peng, Kuan-Chieh

2017-04-01

Taiwan is located in the Western Pacific monsoon region, typhoon is one of the common natural disasters. Taiwan is hit by typhoons 6 times on average each year, and 2016 have 5. Typhoon not only caused the loss of nature environment in Taiwan but also decreased the endangered species- green sea turtle's breeding success rate. In Wangan island, Penghu, green sea turtle nesting beach's slop is too steep to form the dune cliff, block the way which green sea turtle should nesting above the vegetation line. Nesting under the dune cliff is disturbed easily by the swell from typhoon, Leading to the whole nest was emptied or hatching rate decreased due to water content changed. In order to reduce the threat of typhoon on the green sea turtle, and promote the success of green sea turtle reproduction, we used LiDAR(Light Detection And Ranging) to monitor the topographic change of the green sea turtle nesting habitat and compare the invasion and deposition of the green sea turtle nests before and after the occurrence of typhoons. The results showed that the breeding success rate before the typhoon (2016/09/12) was 93%, which was not affected by the swell. The breeding success rate at the higher position after the typhoon was 95%, and under the dune cliff, 10 nests reproduction failed due to the swell changing the sand layer thickness. The production of dune cliffs is formed by the roots of coastal sand-fixation plants. In the past, the residents collected the coastal plants for fuel, after collecting, sparse vegetation is good to form the flat beach, and to promote green sea turtle nesting on the higher position from the disturbance of typhoon. In the future, to protect the success of green sea turtle's reproduction, should increase the human intervention that disturb the nesting beach's vegetation appropriately, Or cutting the roots directly to reduce the dune cliffs before the nesting season, help the green sea turtle nesting in a higher beach, improve the green sea turtle's breeding success rate.

Analysis of a creeping marls event in the coastal cliffs of Bessin, Basse-Normandie, France

NASA Astrophysics Data System (ADS)

Vioget, Alizée; Michoud, Clément; Jaboyedoff, Michel; Maquaire, Olivier; Costa, Stéphane; Davidson, Robert; Derron, Marc-Henri

2015-04-01

The cliffs' retreat is a major issue for the management of coastal territories. Two coastal areas in "Calvados" and "Pays de Caux", French Normandy, are studied. The Bessin cliff is about 4.3 km long and lies between the World War II artillery batteries of Longues-sur-Mer and Arromanches-les-Bains. On the coastline, the cliff's height varies between 10 and 75 meters above sea level. The site's lithology is mainly composed by two formations: the Bessin limestones lie on top of the Port marls, which act as an aquitard. More or less important water outflows are therefore observed at the contact between the marls and the limestone. For this communication, we aim to focus on a complex landslide that happened in May 2013 near Cape Manvieux, estimating volumes and modelling the landslide kinematics. For that purpose, some field observations and measurement have been made in order to make a realistic profile and to understand the steps which lead to this 27 m high and 110 m wide event. In addition, a terrestrial LiDAR (Optech Ilris3D) acquisition of the instability was performed in July 2013 and is compared with the Litto3D (the continued DEM over land and see) acquired in 2011 by the IGN. This comparison shows a maximum cliffs' retreat of about 27 m and 30'000 m3 and a deposit accumulation of about 8 m height. In addition, a limestone rock column of 2'000 m3 and 18 m height within the toppled deposits could still collapse in a short time. Up to now, these site-specific investigations, set in the context of instabilities within the entire study area, let us suppose that the current state of the instability was created by multiple successive events. The landslide could hence be caused by a complex mix of creeping marls conditioned by its water content and pressure induced by overlying formations and toppling of limestone destabilised by the formation of back subvertical crack due to limestone exhumation debuttressing.

Post-eruptive Submarine Terrace Development of Capelinhos, Azores

NASA Astrophysics Data System (ADS)

Zhongwei Zhao, Will; Mitchell, Neil; Quartau, Rui; Tempera, Fernando; Bricheno, Lucy

2017-04-01

Erosion of the coasts of volcanic islands by waves creates shallow banks, but how erosion proceeds with time to create them and how it relates to wave climate is unclear. In this study, historical and recent marine geophysical data collected around the Capelinhos promontory (western Faial Island, Azores) offer an unusual opportunity to characterize how a submarine terrace developed after the eruption. The promontory was formed in 1957/58 during a Surtseyan eruption that terminated with extensive lava forming new rocky coastal cliffs. Historical measurements of coastline position are supplemented here with coastlines measured from 2004 and 2014 Google Earth images in order to characterize coastline retreat rate and distance for lava- and tephra-dominated cliffs. Swath mapping sonars were used to characterize the submarine geometry of the resulting terrace (terrace edge position, gradient and morphology). Limited photographs are available from a SCUBA dive and drop-down camera deployments to ground truth the submarine geomorphology. The results reveal that coastal retreat rates have decreased rapidly with the time after the eruption, possibly explained by the evolving resistance to erosion of cliff base materials. Surprisingly, coastline retreat rate decreases with terrace width in a simple inverse power law with terrace width. We suspect this is only a fortuitous result as wave attenuation over the terrace will not obviously produce the variation, but nevertheless it shows how rapidly the retreat rate declines. Understanding the relationship between terrace widening shelf and coastal cliff retreat rate may be more widely interesting if they can be used to understand how islands evolve over time into abrasional banks and guyots.

Coastal cliff geometry derived from structure-from-motion photogrammetry at Stara Ba\\vska, Krk Island, Croatia

NASA Astrophysics Data System (ADS)

Ružić, Igor; Marović, Ivan; Benac, Čedomir; Ilić, Suzana

2014-12-01

The aim of this study was to examine the capability of structure-from-motion photogrammetry in defining the geometry of cliffs and undercuts in rocks of complex geomorphology. A case site was chosen along pocket beaches near the village of Stara Ba\\vska on the Adriatic Sea island of Krk, Gulf of Kvarner, Croatia, where cliff erosion of 5 m in breccias was identified by comparison of aerial photographs from 1960 and 2004. The 3D point cloud was derived from approx. 800 photos taken on 9 January 2014 by a single camera from various elevations and angles, and processed using the online software ReCap (Autodesk). Data acquisition was found to be quick and the method easy to implement. The difference between the georeferenced 3D cloud points and an RTK-GPS survey was 7 cm, i.e. within the limits of RTK-GPS precision. Quantifying the spatial variation in undercut geometries revealed that the deepest and largest (17 m3) undercut was in the south-eastern sector of the beach. Reconstructing the detailed geomorphology of this 3.8-m-deep undercut convincingly demonstrates the high efficiency of the method. Such assessments of spatiotemporal changes in undercut and overhang volumes can prove useful for evaluations of cliff erosion risk. Coupled with the low cost and relatively simple application, this is evidently an attractive technique for meaningful geotechnical and coastal engineering monitoring in the future on the island of Krk and, for that matter, also on other Adriatic islands and in similar settings worldwide.

New from the Old - Measuring Coastal Cliff Change with Historical Oblique Aerial Photos

NASA Astrophysics Data System (ADS)

Warrick, J. A.; Ritchie, A.

2016-12-01

Oblique aerial photographs are commonly collected to document coastal landscapes. Here we show that these historical photographs can be used to develop topographic models with Structure-from-Motion (SfM) photogrammetric techniques if adequate photo-to-photo overlaps exist. Focusing on the 60-m high cliffs of Fort Funston, California, photographs from the California Coastal Records Project were combined with ground control points to develop topographic point clouds of the study area for five years between 2002 and 2010. Uncertainties in the results were assessed by comparing SfM-derived point clouds with airborne lidar data, and the differences between these data were related to the number and spatial distribution of ground control points used in the SfM analyses. With six or more ground control points the root mean squared error between the SfM and lidar data was less than 0.3 m (minimum = 0.18 m) and the mean systematic error was consistently less than 0.10 m. Because of the oblique orientation of the imagery, the SfM-derived point clouds provided coverage on vertical to overhanging portions of the cliff, and point densities from the SfM techniques averaged between 17 and 161 points/m2 on the cliff face. The time-series of topographic point clouds revealed many topographic changes, including landslides, rockfalls and the erosion of landslide talus along the Fort Funston beach. Thus, we concluded that historical oblique photographs, such as those generated by the California Coastal Records Project, can provide useful tools for mapping coastal topography and measuring coastal change.

Chiral Cliffs: Investigating the Influence of Chirality on Binding Affinity.

PubMed

Schneider, Nadine; Lewis, Richard A; Fechner, Nikolas; Ertl, Peter

2018-05-11

Chirality is understood by many as a binary concept: a molecule is either chiral or it is not. In terms of the action of a structure on polarized light, this is indeed true. When examined through the prism of molecular recognition, the answer becomes more nuanced. In this work, we investigated chiral behavior on protein-ligand binding: when does chirality make a difference in binding activity? Chirality is a property of the 3D structure, so recognition also requires an appreciation of the conformation. In many situations, the bioactive conformation is undefined. We set out to address this by defining and using several novel 2D descriptors to capture general characteristic features of the chiral center. Using machine-learning methods, we built different predictive models to estimate if a chiral pair (a set of two enantiomers) might exhibit a chiral cliff in a binding assay. A set of about 3800 chiral pairs extracted from the ChEMBL23 database was used to train and test our models. By achieving an accuracy of up to 75 %, our models provide good performance in discriminating chiral cliffs from non-cliffs. More importantly, we were able to derive some simple guidelines for when one can reasonably use a racemate and when an enantiopure compound is needed in an assay. We critically discuss our results and show detailed examples of using our guidelines. Along with this publication we provide our dataset, our novel descriptors, and the Python code to rebuild the predictive models. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Towards a geology training and outreach centre in western Ireland

NASA Astrophysics Data System (ADS)

Lacchia, Anthea; Haughton, Peter; Shannon, Patrick

2017-04-01

An outreach and education centre is in the initial phases of development for the coastal area of County Clare, western Ireland. The high Carboniferous sea cliffs of the Loop Head area provide a rich training ground for geoscientists from industry and academia. The cliffs offer a unique, margin-scale perspective of a sedimentary basin fill succession that developed during the height of the Late Palaeozoic glaciation. The rocks, about which there is a long legacy of research, record several glacial cycles, associated with significant eustatic changes in sea level. For geoscientists working with or in industry, the value of the area lies in its analogy with hydrocarbon-bearing, deltaic to deep-water sedimentary successions on several continental margins, such as Miocene and Pliocene successions in the Gulf of Mexico. A programme of behind-outcrop drilling involving UCD and Statoil has acquired over 1350 m of core from 12 boreholes behind the sea cliffs. This core is already being used in training and research both in UCD and at Statoil. The coastal cliffs are also visited by tourists and special interest groups, such as birdwatchers. It is envisioned that the centre will involve the local community and wider public, facilitating links between geoscience, energy and environment. Transport of cores and training materials to the centre, where they will be made available to visiting field parties, is planned for this year. Progress to date, including public engagement activities with schools and at conferences as well as audience research and public consultation, and future plans will be outlined.

Costs and benefits of late nesting in cliff swallows.

PubMed

Brown, Charles R; Roche, Erin A; O'Brien, Valerie A

2015-02-01

Many organisms of temperate latitudes exhibit declines in reproductive success as the breeding season advances. Experiments can delay the onset of reproduction for early breeders to investigate the consequences of late nesting, but it is rarely possible to observe a distinct second round of nesting in species that normally nest only once. The colonial cliff swallow (Petrochelidon pyrrhonota) is a migratory songbird that has a relatively short breeding season in the western Great Plains, USA, with birds rarely nesting late in the summer. Previous work suggested that ectoparasitism is a primary reason why reproductive success in this species declines over the summer. At colony sites where nests were fumigated to remove ectoparasitic swallow bugs (Oeciacus vicarius), cliff swallows frequently undertook a distinct round of late nesting after previously fledging young that year. Mark-recapture revealed that late-nesting pairs at these colonies produced fewer offspring that survived to the next breeding season, and that survival of late-nesting adults was lower during the next year, relative to pairs nesting earlier in the season. These reproductive costs applied in the absence of ectoparasites and likely reflect other environmental costs of late nesting such as seasonal declines in food availability or a delayed start of fall migration. Despite the costs, the estimated fitness for perennial early-and-late nesters in the absence of ectoparasites was equivalent to that of birds that nested only early in the season. The collective disadvantages of late nesting likely constrain most cliff swallows to raising a single brood in the middle latitudes of North America.

Obituary: Clifford G. Toner (1959-2009)

NASA Astrophysics Data System (ADS)

Hill, Frank

2011-12-01

Cliff Toner passed away unexpectedly at home in Tucson, Arizona on March 29, 2009. For most of his career, Cliff was involved with the Global Oscillation Network Group (GONG), a facility of the National Solar Observatory in Tucson, Arizona. GONG is a set of instruments around the world to observe the inside of the sun using the sound that is trapped below the solar surface. This science is called helioseismology. Cliff Toner was born on December 8, 1959 in New Westminster, British Columbia near the western coast of Canada. After receiving his B.Sc. in Physics & Astronomy at the University of British Columbia at Vancouver in 1981, he headed east to the University of Western Ontario in London. His graduate school period was spent in collaboration with David F. Gray, with whom he received both an M.Sc. in Astronomy in 1984, and a Ph.D. in Astronomy in 1988. Toner actually wrote two theses at UWO, one on "Line Asymmetries in F, G, and K Supergiants and Bright Giants" for his M.Sc., and the other on "The Time Variability of Spectral Line Asymmetries and Equivalent Widths for the G8 Dwarf ? Boo A: Evidence for a Starpatch" for his Ph.D. After graduate school, Cliff Toner left the cool climate of Canada in 1988 and accepted a postdoctoral position in the warmer temperatures of Hawai'i at the Institute for Astronomy located at the University of Hawai'i in Honolulu. There he worked primarily with Barry LaBonte. At first, he continued his work on ? Boo A, but he became interested in the sun and helioseismology. This led to the discovery of halos of enhanced high-frequency acoustic power surrounding solar active regions (Ap.J. 415, 847). At the end of his post-doc, Cliff Toner was hired by the GONG project as a Data Scientist in 1991. He quickly tackled the problem of merging the data from the six GONG sites, which was the major data reduction challenge facing GONG at the time. In parallel, he and Stuart Jefferies developed an algorithm to measure the radii of full-disk solar images to a relative precision of 0.01% by determining the zero points of the Hankel transform of the image. As a by-product of the algorithm, the modulation transfer function (MTF) of each image was also obtained, and this led Toner to develop a merging scheme based on the MTF of every image. It proved to be a very effective approach, and both the radii measurement and the merging algorithm remain in daily use in the GONG processing pipeline. However, there was one remaining challenge to assembling the GONG time series in a seamless manner. Each of the six GONG instruments is slightly and unavoidably misaligned with geographic North, producing an angular misregistration of the solar image between sites. Cliff Toner developed a sophisticated optimization scheme that determined a network-wide solution to the relative orientations of the images, and then pinned down the absolute value with drift scans. He further refined the solutions to compensate for gear irregularities in the camera rotator units at the sites. As a result of these algorithms, Toner was able to co-align all of the GONG images to a precision and accuracy of 0.02∘, as verified by his observations of the transits of Mercury and Venus. Without this complex and clever strategy and these extremely important algorithms, it would have been impossible for the GONG data to be merged into a single uniform time series of adequate accuracy for precision helioseismology. Cliff Toner's tireless, selfless, and generally unseen work behind the scenes was essential for the success of GONG. Toner also developed the scheme for merging together the GONG high-cadence magnetograms, and was working on determining the radii of the forthcoming GONG Ha data at the time of his untimely death. Cliff Toner was a very tall man, and colleagues at Hawai'i enjoyed the sight of him riding around the campus on a small moped. Everyone who met him loved him for his patience and willingness to help out. One of his colleagues from his stay in Hawai'i, K.D. Leka, recalls that "Cliff was the embodiment of a "gentle giant"; so tall, yet so soft-spoken and patient, and I just recall a sense of his always being ready to help any living thing. Cliff was out with a back injury in March 1991, and it was under his temporarily-abandoned desk that Betsy, the IfA cat had her one (and only) litter (when my cat Audrey, whom many of you know, was born). As the littermates grew, Cliff, Matt Penn and I had kittens crawling over us; I can still hear his chuckles, "well helloooh, who are you there now?" as they would scramble up his chair to his desk. It was always with a smile that he'd greet me when we ran into each other after the "Hawai'i days"; we'd swap some stories, kid updates but only recently we were more in touch as I'm now playing with GONG data. I was heartened to hear he was working on the magnetogram merging, because I knew it'd be done really well with his attention." Cliff Toner was a caring and loving person, an excellent scientist, and a hero of GONG. He will be sorely missed by everyone who knew him. He is survived by his wife, Nelsey, children, Ariel, Nathaniel, Miranda, and Kayla, sister Gloria, brothers Ethan (Heather) and Emanuel (Lisa).

Rockfalls in cliffs surrounding waterfall revealed by high-definition topographic measurements

NASA Astrophysics Data System (ADS)

Hayakawa, Y. S.; Obanawa, H.

2017-12-01

Bedrock rivers of volcanic terrain often comprise numerous knickpoints. Erosion of bedrock at knickpoints is an essential process of fluvial dissection of volcanic landforms, which also affects the deformations of surrounding slopes. However, short term (less than decadal) changes in bedrock landforms have often been limited to examine in a spatiotemporal framework. Here we use terrestrial laser scanning and SfM-MVS photogrammetry to detect recent annual changes in the morphology of cliffs surrounding a waterfall (Kegon Falls) on jointed andesite lava and conglomerates. The amount of bedrock deformation caused by small rockfalls and surface lowering are assessed in volume, which often appears in a relatively lower portion of the cliff. Such the changes are supposed to be affected by the enhanced supply of water and weathering following the latest major rockfall in 1986 which caused 8-m recession of the waterfall lip. The three-dimensional point cloud data is also utilized to construct a 3D model using cardboards, which is useful for understanding the topography and its changes of the waterfall as educational resources.

Rare earth elements in Angra dos Reis and Lewis Cliff 86010, two meteorites with similar but distinct magma evolutions

NASA Technical Reports Server (NTRS)

Crozaz, Ghislaine; Mckay, Gordon

1990-01-01

Data are presented on ion microprobe measurements of REE and selected trace element abundances in individual grains of merrillite, fassaite, olivine, kirschsteinite, and plagioclase of Lewis Cliff 86010 (LEW 86010) meteorite and in merrillite and fassaite grains of Angra dos Reis (ADOR). Results show a close relationship between the two meteorites and support a magmatic origin for LEW 86010. However, the measurements indicate that, despite numerous common characteristics, the two meteorites must have been produced in separate magmatic events involving similar but distinct processes and parent melts.

Group Size and Nest Spacing Affect Buggy Creek Virus (Togaviridae: Alphavirus) Infection in Nestling House Sparrows

PubMed Central

O'Brien, Valerie A.; Brown, Charles R.

2011-01-01

The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously affected by BCRV. For house sparrows occupying swallow nesting colonies in western Nebraska, USA, the prevalence of BCRV in nestling sparrows increased with sparrow colony size at a site but decreased with the number of cliff swallows present. If one nestling in a nest was infected with the virus, there was a greater likelihood that one or more of its nest-mates would also be infected than nestlings chosen at random. The closer a nest was to another nest containing infected nestlings, the greater the likelihood that some of the nestlings in the focal nest would be BCRV-positive. These results illustrate that BCRV represents a cost of coloniality for a vertebrate host (the house sparrow), perhaps the first such demonstration for an arbovirus, and that virus infection is spatially clustered within nests and within colonies. The decreased incidence of BCRV in sparrows as cliff swallows at a site increased reflects the “dilution effect,” in which virus transmission is reduced when a vector switches to feeding on a less competent vertebrate host. PMID:21966539

Aeolian cliff-top deposits and buried soils in the White River Badlands, South Dakota, USA

USGS Publications Warehouse

Rawling, J. E.; Fredlund, G.G.; Mahan, S.

2003-01-01

Aeolian deposits in the North American Great Plains are important sources of Holocene palaeo-environmental records. Although there are extensive studies on loess and dune records in the region, little is known about records in aeolian cliff-top deposits. These are common on table (mesa) edges in the White River Badlands. These sediments typically have loam and sandy-loam textures with dominantly very fine sand, 0.5-1% organic carbon and 0.5-5% CaCO3. Some of these aeolian deposits are atypically coarse and contain granules and fine pebbles. Buried soils within these deposits are weakly developed with A-C and A-AC-C profiles. Beneath these are buried soils with varying degrees of pedogenic development formed in fluvial, aeolian or colluvial deposits. Thickness and number of buried soils vary. However, late-Holocene soils from several localities have ages of approximately 1300, 2500 and 3700 14C yrs BP. The 1300 14C yr BP soil is cumulic, with a thicker and lighter A horizon. Soils beneath the cliff-top deposits are early-Holocene (typically 7900 but as old as 10000 14C yrs BP) at higher elevation (???950 m) tables, and late-Holocene (2900 14C yrs BP) at lower (???830 m) tables. These age estimates are based on total organic matter 14C ages from the top 5 cm of buried soils, and agreement is good between an infrared stimulated luminescence age and bracketing 14C ages. Our studies show that cliff-top aeolian deposits have a history similar to that of other aeolian deposits on the Great Plains, and they are another source of palaeoenvironmental data.

Geochemical survey of the Devil's Den Roadless Area, Rutland and Windsor counties, Vermont

USGS Publications Warehouse

Slack, J.F.; Atelsek, P.J.; Grosz, A.E.

1985-01-01

The Devils Den area is named for a large undercut cliff (Dale, 1915, p. 21) developed in Precambrian basement rocks. This undercut cliff forms a broad natural cave immediately west of and below Forest Service Road 10, at the head of Mt. Tabor Brook. Another much smaller cave is present in dolomite of probable Paleozoic (Early Cambrian) age on the east side of the same road. This smaller cave apparently is of artificial origin, having been made during early mining of the dolomite (Dale, 1915, p. 21). This man-made cave is the only evidence of previous mining activity within the study area.

Strategic Analysis for the MER Cape Verde Approach

NASA Technical Reports Server (NTRS)

Gaines, Daniel; Belluta, Paolo; Herman, Jennifer; Hwang, Pauline; Mukai, Ryan; Porter, Dan; Jones, Byron; Wood, Eric; Grotzinger, John; Edgar, Lauren;

Satellite View of Opportunity Journey around Victoria Crater

NASA Image and Video Library

2007-01-23

Three years after embarking on a historic exploration of the red planet and six miles away from its landing site, NASA's Mars Exploration Rover Opportunity is traversing "Victoria Crater" ridge by ridge, peering at layered cliffs in the interior. To identify various alcoves and cliffs along the way, science team members are using names of places visited by the 16th-century Earth explorer Ferdinand Magellan and his crew aboard the ship Victoria, who proved the Earth is round. (All names are unofficial unless approved by the International Astronomical Union.) This orbital view of "Victoria Crater" was taken by NASA's Mars Reconnaissance Orbiter. http://photojournal.jpl.nasa.gov/catalog/PIA09116

Major off-axis hydrothermal activity on the northern Gorda Ridge

USGS Publications Warehouse

Rona, Peter A.; Denlinger, Roger P.; Fisk, M. R.; Howard, K. J.; Taghon, G. L.; Klitgord, Kim D.; McClain, James S.; McMurray, G. R.; Wiltshire, J. C.

1990-01-01

The first hydrothermal field on the northern Gorda Ridge, the Sea Cliff hydrothermal field, was discovered and geologic controls of hydrothermal activity in the rift valley were investigated on a dive series using the DSV Sea Cliff. The Sea Cliff hydrothermal field was discovered where predicted at the intersection of axis-oblique and axis-parallel faults at the south end of a linear ridge at mid-depth (2700 m) on the east wall. Preliminary mapping and sampling of the field reveal: a setting nested on nearly sediment-free fault blocks 300 m above the rift valley floor 2.6 km from the axis; a spectrum of venting types from seeps to black smokers; high conductive heat flow estimated to be equivalent to the convective flux of multiple black smokers through areas of the sea floor sealed by a caprock of elastic breccia primarily derived from basalt with siliceous cement and barite pore fillings; and a vent biota with Juan de Fuca Ridge affinites. These findings demonstrate the importance of off-axis hydrothermal activity and the role of the intersection of tectonic lineations in controlling hydrothermal sites at sea-floor spreading centers.

A prospective analysis of injury rates, patterns and causes in Cliff and Splash Diving.

PubMed

Ernstbrunner, Lukas; Runer, Armin; Siegert, Paul; Ernstbrunner, Matthäus; Becker, Johannes; Freude, Thomas; Resch, Herbert; Moroder, Philipp

2017-10-01

Information about injuries and its differences in Cliff Diving (CD) and Splash Diving (SD) are unknown. It was the aim to analyse (1) injury rates, patterns and causes; (2) differences (in injuries) between both disciplines; and to (3) identify targets for future injury prevention interventions. From April to November 2013, 81 cliff and 51 splash divers were prospectively surveyed with an encrypted, monthly e-mail-based questionnaire. During a total of 7857h diving with an average diving height of 13 (±7)m, an overall injury rate of 7.9 injuries/1000h of sport exposure was reported. Cliff divers most commonly suffered from injuries of the foot and ankle (18%; n=24) and neck and cervical spine (14%; n=19). In SD, the lower limb (52%; n=43) and lower back (23%; n=19) were most frequently involved. In 79% (n=49) of the cases, the injury happened while entering the water. Cliff divers were in 52% (n=15) of the injuries in a feet-first and in 14% (n=4) in a head-first position. Splash divers were in 45% (n=9) of the injuries in a back- or buttocks-first position. Most of the injuries were bruises (47%; n=104) and muscle strains (13%; n=28). The injury risk during practice was significantly higher than in competition (11.3 vs. 4.5 injuries/1000h; OR 2.5; p=0.001). The injury risk of experts (15.4/1000h exposure) was significantly higher than in professionals (6.3/1000h exposure; OR 2.4; 95% CI, 3.3-1.9; p<0.001), although the average diving height was significantly higher in professionals (19m±8 vs. 12m±6; p<0.001). Significantly more professionals performed dryland training compared to experts (p=0.006). Most of the injuries are related to the water entry. The entry position plays a key role in injury patterns with pursuant differences comparing CD with SD. Although most of the injuries involved soft-tissue only, severe injuries have been reported. Targets for future injury prevention strategies include protection for the increased impaction at entry; adaption of the diving conditions in practice to those in competition; dryland training courses; and instruction of non-professional divers to teach appropriate diving techniques. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamics of a recovering Arctic bird population: the importance of climate, density dependence, and site quality

USGS Publications Warehouse

Bruggeman, Jason E.; Swem, Ted; Andersen, David E.; Kennedy, Patricia L.; Nigro, Debora A.

2015-01-01

Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement weather early in the breeding season can inhibit egg-laying and reduce productivity. Also, density-dependent regulation occurs in raptor populations, as territory size is related to resource availability. Arctic Peregrine Falcons (Falco peregrinus tundrius; hereafter Arctic peregrine) have a limited and northern breeding distribution, including the Colville River Special Area (CRSA) in the National Petroleum Reserve–Alaska, USA. We quantified influences of climate, topography, nest productivity, prey habitat, density dependence, and interspecific competition affecting Arctic peregrines in the CRSA by applying the Dail-Madsen model to estimate abundance and vital rates of adults on nesting cliffs from 1981 through 2002. Arctic peregrine abundance increased throughout the 1980s, which spanned the population's recovery from DDT-induced reproductive failure, until exhibiting a stationary trend in the 1990s. Apparent survival rate (i.e., emigration; death) was negatively correlated with the number of adult Arctic peregrines on the cliff the previous year, suggesting effects of density-dependent population regulation. Apparent survival and arrival rates (i.e., immigration; recruitment) were higher during years with earlier snowmelt and milder winters, and apparent survival was positively correlated with nesting season maximum daily temperature. Arrival rate was positively correlated with average Arctic peregrine productivity along a cliff segment from the previous year and initial abundance was positively correlated with cliff height. Higher cliffs with documented higher productivity (presumably indicative of higher-quality habitat), are a priority for continued protection from potential nearby development and disturbance to minimize population-level impacts. Climate change may affect Arctic peregrines in multiple ways, including through access to more snow-free nest sites and a lengthened breeding season that may increase likelihood of nest success. Our work provides insight into factors affecting a population during and after recovery, and demonstrates how the Dail-Madsen model can be used for any unmarked population with multiple years of abundance data collected through repeated surveys.

Investigating Mars: Candor Chasma

NASA Image and Video Library

2018-01-11

This image shows part of eastern Candor Chasma. At the top of the image is the steep cliff between the upper surface elevation and the depths of Candor Chasma. The bottom of the image is the cliff side of a large mesa. The two cliff faces have very different appearances. The cliff face between the top of the canyon and the bottom is likely layers of volcanic flows from the nearby Tharsis volcanoes. The mesa, however, is probably layers of sediments deposited in the canyon from wind, water and gravity driven erosion and deposition. These layered materials are much more easily eroded than the solid rock of the canyon sides. Candor Chasma is one of the largest canyons that make up Valles Marineris. It is approximately 810 km long (503 miles) and has is divided into two regions - eastern and western Candor. Candor is located south of Ophir Chasma and north of Melas Chasma. The border with Melas Chasma contains many large landslide deposits. The floor of Candor Chasma includes a variety of landforms, including layered deposits, dunes, landslide deposits and steep sided cliffs and mesas. Many forms of erosion have shaped Chandor Chasma. There is evidence of wind and water erosion, as well as significant gravity driven mass wasting (landslides). The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions. Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all. For the next several months the image of the day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images! Orbit Number: 9540 Latitude: -6.76471 Longitude: 292.539 Instrument: VIS Captured: 2004-02-07 20:41 https://photojournal.jpl.nasa.gov/catalog/PIA22163

Increase of Coastal Cliff Rockfall Trigerred By Rainfall On The Chalk Coast of NW France During The Year 2001

NASA Astrophysics Data System (ADS)

Duperret, A.; Genter, A.; Daigneault, M.; Mortimore, R. N.

Coastal chalk cliffs exposed on each part of the English Channel suffer numerous collapses, with mean volumes varying between 10 000 and 100 000 cubic meters. Between October 1998 and October 2001, a minimum of 52 collapses have been ob- served along 120 km of the French chalk coastline located in Upper-Normandy and Picardy. The chalk coastline has evidenced 4 collapses in 1999 and 6 collapses in 2000 (winter and spring), whereas 28 collapses with volume greater than 1000 m3 was recorded in 2001 (winter, spring and summer). The increase of large-scale collapses during 2001 is interpreted as an excess of rainfalls recorded previously. Most of these collapses extend all over the vertical cliff height and are mainly controlled by ground- water infiltration. The modality of water circulation through the chalk rock depends on the chalk lithology and the hydrogeological properties of pre-existing fractures. In the framework of the European scientific project named ROCC (Risk of Cliff Col- lapse), the chalk lithology and the pre-existing fracture pattern have been investigated in order to determine the response of the rock mass to subaerial and marine solicita- tions, including rainfall conditions. Such data have been reported in a GIS system in order to determine the degree of cliff sensibility to collapses. Some rainfall-triggered collapses will be presented to illustrate the diversity of the rock mass response to rain- fall excess, in terms of rock mass characteristics and time delay: (1) a collapse was witnessed at Puys, the 17th May 2000, after two periods of intense rainfall inducing floods, during the two previous months. The occurrence of impervious marl seams levels within the chalk and its low fracture content may have generated water over- pressure and consequently stress concentration on the marl seams, which conduct to the rupture. The delay between rainfall and the rupture may be explained by the low velocity of groundwater through a poorly fractured porous chalk. (2) a series of large- scale collapses has been evidenced at Yport in June 2001, at Grandes Dalles the 15th July 2001 and at Benouville the 24th July 2001. These collapses occurred after a dry period, during the previous three months. A collapse occurred again at Yport the 27th August 2001, after an increase of rainfall during August 2001. All these sites present the same lithological chalk succession than at Puys, but their fracture pattern is made of large-scale subvertical fractures expanding all over the cliff height. Some of them 1 which correspond to dissolution pipes are filled with clays-with-flints. The sharp in- crease of collapses during the summer 2001 could be related to the superimposition of dry periods which alternate with heavy rainfalls, in karst environment. 2

Strategic analysis for the MER Cape Verde approach

USGS Publications Warehouse

Gaines, D.; Belluta, P.; Herman, J.; Hwang, P.; Mukai, R.; Porter, D.; Jones, B.; Wood, E.; Grotzinger, J.; Edgar, L.; Hayes, A.; Hare, T.; Squyres, S.

2009-01-01

The Mars Exploration Rover Opportunity has recently completed a two year campaign studying Victoria Crater. The campaign culminated in a close approach of Cape Verde in order to acquire high resolution imagery of the exposed stratigraphy in the cliff face. The close approach to Cape Verde provided significant challenges for every subsystem of the rover as the rover needed to traverse difficult, uncharacterised terrain and approach a cliff face with the potential of blocking out solar energy and communications with Earth. In this paper we describe the strategic analyses performed by the science and engineering teams so that we could successfully achieve the science objectives while keeping the rover safe. ??2009 IEEE.

Integration of ambient seismic noise monitoring, displacement and meteorological measurements to infer the temperature-controlled long-term evolution of a complex prone-to-fall cliff

NASA Astrophysics Data System (ADS)

Colombero, C.; Baillet, L.; Comina, C.; Jongmans, D.; Larose, E.; Valentin, J.; Vinciguerra, S.

2018-06-01

Monitoring the temporal evolution of resonance frequencies and velocity changes detected from ambient seismic noise recordings can help in recognizing reversible and irreversible modifications within unstable rock volumes. With this aim, the long-term ambient seismic noise data set acquired at the potentially unstable cliff of Madonna delSasso (NW Italian Alps) was analysed in this study, using both spectral analysis and cross-correlation techniques. Noise results were integrated and compared with direct displacement measurements and meteorological data, to understand the long-term evolution of the cliff. No irreversible modifications in the stability of the site were detected over the monitored period. Conversely, daily and seasonal air temperature fluctuations were found to control resonance frequency values, amplitudes and directivities and to induce reversible velocity changes within the fractured rock mass. The immediate modification in the noise parameters due to temperature fluctuations was interpreted as the result of rock mass thermal expansion and contraction, inducing variations in the contact stiffness along the fractures isolating two unstable compartments. Differences with previous case studies were highlighted in the long-term evolution of noise spectral amplitudes and directivities, due to the complex 3-D fracture setting of the site and to the combined effects of the two unstable compartments.

Some aspects of lithological and exogenic control of sandstone morphology, the Świętokrzyskie (Holy Cross) Mts. case study, Poland

NASA Astrophysics Data System (ADS)

Urban, Jan; Górnik, Marek

2017-10-01

Various morphologies of cliffs built of different quartzose rocks in the Świętokrzyskie (Holy Cross) Mts. (upland region, central Poland) - from Cambrian quartzites and Devonian quartzitic sandstones to Triassic and Jurassic porous sandstones - were described in order to examine the constraints of their lithological and spatial occurrence. The quantitative study of the occurrence of these morphologies on cliffs makes it possible to distinguish two principal groups of morphologies: angular relief produced by rock splitting (crumbling), typical of quartzites indurated in silica and of open porosity less than 1.5%, and morphologies developed due to granular disintegration and exfoliation of sandstones of open porosity higher than 1.5%. Among the relief types of this second group, morphology reflecting sedimentary and diagenetic structures as well as smooth surfaces are the most common and are referred to sandstones of a wide range of porosity, whereas honeycombs and surfaces suffering fast granular decay and scaling are characteristic of rocks of specific porosity (respectively: 5-8% and 3.5-8%). The occurrence of honeycombs on rock surfaces is also conditioned by exogenic factors: sun, wind and rain, since this morphology tends to occur on cliffs with aspects ranging from south-east, through south, to west-north-west.

Fluctuating viability selection on morphology of cliff swallows is driven by climate

PubMed Central

Brown, Charles R.; Brown, Mary Bomberger; Roche, Erin A.

2014-01-01

The extent to which fluctuating selection can maintain evolutionary stasis in most populations remains an unresolved question in evolutionary biology. Climate has been hypothesized to drive reversals in the direction of selection among different time periods and may also be responsible for intense episodic selection caused by rare weather events. We measured viability selection associated with morphological traits in cliff swallows (Petrochelidon pyrrhonota) in western Nebraska, U.S.A., over a 14-year period following a rare climatic event. We used mark-recapture to estimate the annual apparent survival of over 26,000 individuals whose wing, tail, tarsus, and bill had been measured. The fitness functions associated with tarsus length and bill dimensions fluctuated depending on annual climate conditions on the birds’ breeding grounds. The oscillating yearly patterns may have slowed and occasionally reversed directional change in trait trajectories, although there was a trend over time for for all traits except tarsus to increase in size. The net positive directional selection on some traits, despite periodic climate-associated fluctuations, suggests that cliff swallow morphology in the population is likely to keep changing and supports recent work contending that selection in general does not fluctuate enough to be an effective driver of stasis. PMID:23510182

Uranophane at Silver Cliff mine, Lusk, Wyoming

USGS Publications Warehouse

Wilmarth, Verl R.; Johnson, D.H.

1954-01-01

The uranium deposit at the Silver Cliff mine near Lusk, Wyo., consists primarily of uranophane which occurs as fracture fillings and small replacement pockets in faulted and fractured calcareous sandstone of Cambrian (?) age. The country rock in the vicinity of the mine is schist of pre-Cambrian age intruded by pegmatite dikes and is unconformably overlain by almost horizontal sandstone of Cambrian(?) age. The mine is on the southern end of the Lusk Dome, a local structure probably related to the Hartville uplift. In the immediate vicinity of the mine, the dome is cut by the Silver Cliff fault, a north-trending high-angle reverse fault about 1,200 feet in length with a stratigraphic throw of 70 feet. Uranophane, metatorbernite, pitchblende, calcite, native silver, native copper, chalcocite, azurite, malachite, chrysocolla, and cuprite have been deposited in fractured sandstone. The fault was probably mineralized throughout its length, but because of erosion, the mineralized zone is discontinuous. The principal ore body is about 800 feet long. The width and depth of the mineralized zone are not accurately known but are at least 20 feet and 60 feet respectively. The uranium content of material sampled in the mine ranges from 0.001 to 0.23 percent uranium, whereas dump samples range from 0.076 to 3.39 percent uranium.

Hot spring deposits on a cliff face: A case study from Jifei, Yunnan Province, China

NASA Astrophysics Data System (ADS)

Jones, Brian; Peng, Xiaotong

2014-04-01

A cliff face in the Jifei karst area, southwest China, is covered by a spectacular succession of precipitates that formed from the hot spring water that once flowed down its surface. This layered succession is formed of aragonite layers that are formed largely of “fountain dendrites”, calcite layers that are formed mostly of “cone dendrites”, and microlaminated layers that contain numerous microbes and extracellular polymeric substances (EPS). Many of the aragonite crystals are hollow due to preferential dissolution of their cores. The calcite cone dendrites are commonly covered with biofilms, reticulate Si-Mg coatings, and other precipitates. The microbial layers include dodecahedral calcite crystals and accessory minerals that include opal-A, amorphous Si-Mg coatings, trona, barite, potassium sulfate crystals, mirabillite, and gaylussite. Interpretation of the δ18O(calcite) and δ18O(aragonite) indicates precipitation from water with a temperature of 54 to 66 °C. The active hot spring at the top of the cliff presently ejects water at a temperature of 65 °C. Layers, 1 mm to 6 cm thick, record temporal changes in the fluids from which the precipitates formed. This succession is not, however, formed of recurring cycles that can be linked to diurnal or seasonal changes in the local climate. Indeed, it appears that the climatic contrast between the wet season and the dry season had little impact on precipitation from the spring waters that flowed down the cliff face. Integration of currently available evidence suggests that the primary driving force was aperiodic changes in the CO2 content of the spring waters because that seems to be the prime control on the saturation levels that underpinned precipitation of the calcite and aragonite as well as the dissolution of the aragonite. Such variations in the CO2 content of the spring water were probably due to changes that took place in the subterranean plumbing system of the spring.

The importance of source area mapping for rockfall hazard analysis

NASA Astrophysics Data System (ADS)

Valagussa, Andrea; Frattini, Paolo; Crosta, Giovanni B.

2013-04-01

A problem in the characterization of the area affected by rockfall is the correct source areas definition. Different positions or different size of the source areas along a cliff result in different possibilities of propagation and diverse interaction with passive countermeasures present in the area. Through the use of Hy-Stone (Crosta et al., 2004), a code able to perform 3D numerical modeling of rockfall processes, different types of source areas were tested on a case study slope along the western flank of the Mt. de La Saxe (Courmayeur, AO), developing between 1200 and 2055 m s.l.m. The first set of source areas consists of unstable rock masses identified on the basis of field survey and Terrestrial Laser Scanning (IMAGEO, 2011). A second set of source areas has been identified by using different thresholds of slope gradient. We tested slope thresholds between 50° and 75° at 5° intervals. The third source area dataset has been generating by performing a kinematic stability analysis. For this analysis, we mapped the join sets along the rocky cliff by means of the software COLTOP 3D (Jaboyedoff, 2004), and then we identified the portions of rocky cliff where planar/wedge and toppling failures are possible assuming an average friction angle of 35°. Through the outputs of the Hy-Stone models we extracted and analyzed the kinetic energy, height of fly and velocity of the blocks falling along the rocky cliff in order to compare the controls of different source areas. We observed strong variations of kinetic energy and fly height among the different models, especially when using unstable masses identified through Terrestrial Laser Scanning. This is mainly related to the size of the blocks identified as susceptible to failure. On the contrary, the slope gradient thresholds does not have a strong impact on rockfall propagation. This contribution highlights the importance of a careful and appropriate mapping of rockfall source area for rockfall hazard analysis and the design of passive countermeasures.

Boulder aprons indicate long-term gradual and non-catastrophic evolution of cliffed escarpments, Stołowe Mts, Poland

NASA Astrophysics Data System (ADS)

Duszyński, Filip; Migoń, Piotr

2015-12-01

Caprock-crowned escarpments are characteristic geomorphic features of the sandstone tableland of the Stołowe Mountains (SW Poland). Their mid- and lower slopes truncate weaker sedimentary formations but are littered with sandstone boulders of various size, often more than 5 m long, which form nearly continuous aprons. A model of escarpment retreat by rock fall has been widely accepted in literature but in the Stołowe Mountains it has never been tested against field evidence; in addition no rock fall events except one minor fall in 1921 have been recorded in historical times. In this paper we erected five hypotheses of how escarpments may have evolved through time to result in widespread boulder presence on the slopes. Mapping boulder extent and slope morphology, run-out distance simulations using Conefall software, and rock strength determinations using the Schmidt hammer carried out on boulders along eight representative slope profiles provide data about characteristics of the boulder covers. Systematic decrease in intact rock strength with an increasing distance from the sandstone cliffs suggests that the boulder aprons are diachronic and record long-term retreat of escarpments. There exists no conclusive evidence of widespread boulder downslope movement, although in a few localities shallow landslides have rafted boulders far away from the cliff lines. Modelling exercise shows that the actual extent of boulders is 2-3 times bigger than suggested by Conefall predictions. These findings, coupled with observations along the cliff lines themselves, lead us to propose a model of free face in situ disintegration as the most likely hypothesis to explain block detachment and release from rock faces. As cliff lines recede and the slope surface below is lowered, remnant boulders occupy a position increasingly further away from escarpment rims, but experience little actual movement. This model complements the existing models of tableland evolution which tend to emphasize catastrophic mass movement processes on cliffed escarpments.

Investigating Mars: Candor Chasma

NASA Image and Video Library

2018-01-10

This image shows part of eastern Candor Chasma. At the bottom of the image is the steep cliff between the upper surface elevation and the depths of Candor Chasma. The small lobate feature at the base of the cliff in the bottom of the image is a landslide deposit formed by failure of the cliff face and gravitational downslope movement of the material. Candor Chasma is one of the largest canyons that make up Valles Marineris. It is approximately 810 km long (503 miles) and has is divided into two regions - eastern and western Candor. Candor is located south of Ophir Chasma and north of Melas Chasma. The border with Melas Chasma contains many large landslide deposits. The floor of Candor Chasma includes a variety of landforms, including layered deposits, dunes, landslide deposits and steep sided cliffs and mesas. Many forms of erosion have shaped Chandor Chasma. There is evidence of wind and water erosion, as well as significant gravity driven mass wasting (landslides). The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions. Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all. For the next several months the image of the day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images! Orbit Number: 8916 Latitude: -7.95016 Longitude: 293.509 Instrument: VIS Captured: 2003-12-18 11:38 https://photojournal.jpl.nasa.gov/catalog/PIA22162

Coastal cliffs, rock-slope failures and Late Quaternary transgressions of the Black Sea along southern Crimea

NASA Astrophysics Data System (ADS)

Pánek, Tomáš; Lenart, Jan; Hradecký, Jan; Hercman, Helena; Braucher, Règis; Šilhán, Karel; Škarpich, Václav

2018-02-01

Rock-slope failures represent a significant hazard along global coastlines, but their chronology remains poorly documented. Here, we focus on the geomorphology and chronology of giant rockslides affecting the Crimean Mountains along the Black Sea coast. Geomorphic evidence suggests that high (>100 m) limestone cliffs flanking the southern slopes of the Crimean Mountains are scarps of rockslides nested within larger deep-seated gravitational slope deformations (DSGSDs). Such pervasive slope failures originated due to lateral spreading of intensively faulted Late Jurassic carbonate blocks moving atop weak/plastic Late Triassic flysch and tuff layers. By introducing a dating strategy relying on the combination of the uranium-thorium dating (U-Th) of exposed calcareous speleothems covering the landslide scarps with the 36Cl exposure dating of rock walls, we are able to approximate the time interval between the origin of incipient crevices and the final collapse of limestone blocks that exposed the cliff faces. For the three representative large-scale rockslides between the towns of Foros and Yalta, the initiation of the DSGSDs as evidenced by the widening of crevices and the onset of speleothem accumulation was >300 ka BP, but the recent cliff morphology along the coast is the result of Late Pleistocene/Holocene failures spanning ∼20-0.5 ka BP. The exposures of rockslide scarps occurred mostly at ∼20-15, ∼8, ∼5-4 and ∼2-0.5 ka, which substantially coincide with the last major Black Sea transgressions and/or more humid Holocene intervals. Our study suggests that before ultimate fast and/or catastrophic slope failures, the relaxation of rock massifs correlative with karstification, cracks opening, and incipient sliding lasted on the order of 104-105 years. Rapid Late Glacial/Holocene transgressions of the Black Sea likely represented the last impulse for the collapse of limestone blocks and the origin of giant rockslides, simultaneously affecting the majority of the SW coast of the Crimean Peninsula.

Becquerel Crater Deposit

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 28 May 2002) The finely layered deposit in Becquerel crater, seen in the center of this THEMIS image, is slowly being eroded away by the action of windblown sand. Dark sand from a source north of the bright deposit is collecting along its northern edge, forming impressive barchan style dunes. These vaguely boomerang-shaped dunes form with their two points extending in the downwind direction, demonstrating that the winds capable of moving sand grains come from the north. Grains that leave the dunes climb the eroding stair-stepped layers, collecting along the cliff faces before reaching the crest of the deposit. Once there, the sand grains are unimpeded and continue down the south side of the deposit without any significant accumulation until they fall off the steep cliffs of the southern margin. The boat-hull shaped mounds and ridges of bright material called yardangs form in response to the scouring action of the migrating sand. To the west, the deposit has thinned enough that the barchan dunes extend well into the deeply eroded north-south trending canyons. Sand that reaches the south side collects and reforms barchan dunes with the same orientation as those on the north side of the deposit. Note the abrupt transition between the bright material and the dark crater floor on the southern margin. Steep cliffs are present with no indication of rubble from the obvious erosion that produced them. The lack of debris at the base of the cliffs is evidence that the bright material is readily broken up into particles that can be transported away by the wind. The geological processes that are destroying the Becquerel crater deposit appear active today. But it is also possible that they are dormant, awaiting a particular set of climatic conditions that produces the right winds and perhaps even temperatures to allow the erosion to continue.

Sandy beaches in a coastline vulnerable to erosion in Atlantic Canada: Macrobenthic community structure in relation to backshore and physical features

NASA Astrophysics Data System (ADS)

MacMillan, Mitchell R.; Duarte, Cristian; Quijón, Pedro A.

2017-07-01

Most literature suggests that sandy beach macrobenthic communities are structured by physical factors. However, an aspect that has not been studied in detail is whether those physical factors change with erosion or the association of beaches to backshore features like sand dunes, till bluffs, and sandstone cliffs. We addressed this question by sampling 14 sandy beaches on the north shore of Prince Edward Island, Atlantic Canada. Two null hypotheses were tested: first, there is no relationship between physical factors and community descriptors across sandy beaches, and second, there is no difference among beaches associated with distinct backshore features both in terms of physical factors and community descriptors. In order to test these hypotheses, samples of macrobenthic organisms and measurements of grain size, slope, beach deposit index and erosion rates were obtained. Our surveys collected a total of 14 taxa numerically dominated by the spionid polychaete Scolelepis squamata. With regards to the first hypothesis, regression analyses showed that community descriptors were all positively related to erosion rates while unrelated to the variation in grain size, slope and beach deposit index. As for the second hypothesis, erosion rates were significantly different among beaches associated to till bluffs (highest), dunes and sandstone cliffs (lowest). Meanwhile, the other physical factors did not significantly differ among backshore features. Species richness was highest in beaches associated to till bluffs and lowest in those associated to sandstone cliffs. Abundance values were also lowest in beaches associated to sandstone cliffs, and their community composition was significantly different to those associated to dunes and till bluffs. We suggest that the relationship between erosion rates and community descriptors is complex and may be mediated by the availability of nutrients: higher erosion levels might account for higher concentrations of nutrients for suspension feeders, the numerically dominant organisms in this system. We call for further attention to the relationship between erosion and suspended nutrients.

Genetic Fingerprinting of Germplasm Accessions as an Aid for Species Conservation: A Case Study with Borderea chouardii (Dioscoreaceae), One of the Most Critically Endangered Iberian Plants

PubMed Central

SEGARRA-MORAGUES, JOSÉ GABRIEL; IRIONDO, JOSÉ MARÍA; CATALÁN, PILAR

2005-01-01

• Background and Aims Molecular markers have changed previous expectations about germplasm collections of endangered plants, as new perspectives aim at holding a significant representation of all the genetic diversity in the studied species to accomplish further conservation initiatives successfully. Borderea chouardii is a critically endangered allotetraploid dioecious member of Dioscoreaceae, known from a single population in the Iberian pre-Pyrenees. This population was reported to be highly structured into two genetically distinct groups of individuals corresponding to their spatial separation along the vertical cliff where it grows. In 1999, the Spanish Government of Aragón launched the first conservation programme for the ex situ preservation of this species, and since then a seed collection has been conserved at the Germplasm Bank of the Universidad Politécnica de Madrid. However, as some seed samples had not been labelled clearly at the time of collection, their origin was uncertain. • Methods Genetic variation in germplasm accessions of B. chouardii was investigated using microsatellite (simple sequence repeat; SSR) markers. • Key Results The 17 primer pairs used detected 62 SSR alleles in the 46 samples analysed from five different germplasm stocks. Eight alleles scored from the wild population were not detected in the germplasm samples analysed. The relatedness of the germplasm samples to the wild subpopulations through neighbour-joining clustering, principal coordinates analysis (PCO) and assignment tests revealed a biased higher representation of the genetic diversity of the lower cliff (43 samples) subpopulation than that of the upper cliff (three samples). • Conclusions The collection of additional samples from the upper cliff is recommended to achieve a better representation of the genetic diversity of this subpopulation. It is also recommended that these stocks should be managed separately according to their distinct microspatial origin in order to preserve the genetic substructuring of the wild population. PMID:16230324

Recurrent patterning in the daily foraging routes of hamadryas baboons (Papio hamadryas): spatial memory in large-scale versus small-scale space.

PubMed

Schreier, Amy L; Grove, Matt

2014-05-01

The benefits of spatial memory for foraging animals can be assessed on two distinct spatial scales: small-scale space (travel within patches) and large-scale space (travel between patches). While the patches themselves may be distributed at low density, within patches resources are likely densely distributed. We propose, therefore, that spatial memory for recalling the particular locations of previously visited feeding sites will be more advantageous during between-patch movement, where it may reduce the distances traveled by animals that possess this ability compared to those that must rely on random search. We address this hypothesis by employing descriptive statistics and spectral analyses to characterize the daily foraging routes of a band of wild hamadryas baboons in Filoha, Ethiopia. The baboons slept on two main cliffs--the Filoha cliff and the Wasaro cliff--and daily travel began and ended on a cliff; thus four daily travel routes exist: Filoha-Filoha, Filoha-Wasaro, Wasaro-Wasaro, Wasaro-Filoha. We use newly developed partial sum methods and distribution-fitting analyses to distinguish periods of area-restricted search from more extensive movements. The results indicate a single peak in travel activity in the Filoha-Filoha and Wasaro-Filoha routes, three peaks of travel activity in the Filoha-Wasaro routes, and two peaks in the Wasaro-Wasaro routes; and are consistent with on-the-ground observations of foraging and ranging behavior of the baboons. In each of the four daily travel routes the "tipping points" identified by the partial sum analyses indicate transitions between travel in small- versus large-scale space. The correspondence between the quantitative analyses and the field observations suggest great utility for using these types of analyses to examine primate travel patterns and especially in distinguishing between movement in small versus large-scale space. Only the distribution-fitting analyses are inconsistent with the field observations, which may be due to the scale at which these analyses were conducted. © 2013 Wiley Periodicals, Inc.

Investigations of the Origin of the Magnetic Remanence in Late Pleistocene Lacustrine Sediments in the Mono Basin, CA

NASA Astrophysics Data System (ADS)

Vasquez, N.; Corley, A. D.

2015-12-01

In the Mono Basin, CA, fine sand, silt, and volcanic ash deposited in Pleistocene Lake Russell is exposed on the margin of Mono Lake, and on Paoha Island in the lake. The silt records the Mono Lake Excursion (MLE: Denham and Cox, 1971) and several tens of thousands of years of paleomagnetic secular variation (PSV: Denham and Cox, 1971; Liddicoat, 1976; Lund et al., 1988). The sediment is believed to be an accurate recorder of PSV because the MLE has the same signal at widely separated localities in the basin (Denham, 1974; Liddicoat and Coe, 1979; Liddicoat, 1992) with the exception at wave-cut cliffs on the southeast side of the lake (Coe and Liddicoat, 1994). Magnetite, titanomagnetite, and titanomaghemite are present in the sediment (Denham and Cox, 1971; Liddicoat, 1976; Liddicoat and Coe, 1979), which is glacial flour from the adjacent Sierra Nevada (Lajoie, 1968). X-rays of the sediment and lineation measurements show patterns of normal bedding with layers aligned such that the minimum axes are within 5-10 degrees of normal bedding, with 10 percent foliation and 1 percent lineation (Coe and Liddicoat, 1994). We explore reasons for the difference in part of the PSV record at the wave-cut cliffs beyond the interpretation of Coe and Liddicoat (1994) that paleomagnetic field strength is a controlling factor. Possibilities include the sedimentation rate - at localities on the margin of Mono Lake the rate is about 60 percent less than at the wave-cut cliffs - and lithology of the sediment. At Mill Creek on the northwest side of Mono Lake, the non-magnetic sediment fraction is coarser-grained than at the wave-cut cliffs by a factor of about two, and there is a similar difference in the total inorganic carbon (TIC) percentage by weight for the two localities. (Spokowski et al., 2011) Studies of the sediment at two localities in the basin where the Hilina Pali Excursion (Teanby et al., 2002) might be recorded (Wilson Creek and South Shore Cliffs; Liddicoat and Coe, 2013) and at an extension of the PSV record of Lund et al. (1988) show a similar pattern to the grain size distribution and TIC percentage described above. Additional measurements of the TIC in the sediments from both sides of Mono Lake for the intervals recording the possible HPE and PSV extension of Lund et al. (1988) are in progress and will be presented.

Supraglacial lakes on Himalayan debris-covered glacier (Invited)

NASA Astrophysics Data System (ADS)

Sakai, A.; Fujita, K.

2013-12-01

Debris-covered glaciers are common in many of the world's mountain ranges, including in the Himalayas. Himalayan debris-covered glacier also contain abundant glacial lakes, including both proglacial and supraglacial types. We have revealed that heat absorption through supraglacial lakes was about 7 times greater than that averaged over the whole debris-covered zone. The heat budget analysis elucidated that at least half of the heat absorbed through the water surface was released with water outflow from the lakes, indicating that the warm water enlarge englacial conduits and produce internal ablation. We observed some portions at debris-covered area has caved at the end of melting season, and ice cliff has exposed at the side of depression. Those depression has suggested that roof of expanded water channels has collapsed, leading to the formation of ice cliffs and new lakes, which would accelerate the ablation of debris-covered glaciers. Almost glacial lakes on the debris-covered glacier are partially surrounded by ice cliffs. We observed that relatively small lakes had non-calving, whereas, calving has occurred at supraglacial lakes with fetch larger than 80 m, and those lakes expand rapidly. In the Himalayas, thick sediments at the lake bottom insulates glacier ice and lake water, then the lake water tends to have higher temperature (2-4 degrees C). Therefore, thermal undercutting at ice cliff is important for calving processes in the glacial lake expansion. We estimated and subaqueous ice melt rates during the melt and freeze seasons under simple geomorphologic conditions. In particular, we focused on valley wind-driven water currents in various fetches during the melt season. Our results demonstrate that the subaqueous ice melt rate exceeds the ice-cliff melt rate above the water surface when the fetch is larger than 20 m with the water temperature of 2-4 degrees C. Calculations suggest that onset of calving due to thermal undercutting is controlled by water currents driven by winds at the lake surface with a positive feedback process. The risk of GLOFs (glacial lake outburst flood) are analysed for Himalayan glacial lakes. We proposed an objective index for GLOF probability, based on depression angle from the lakeshore, which allows the lakes to be assessed using remotely sensed digital elevation models (DEMs). The index was verified by pre-GLOF topography derived by spy satellite imageries. We screened 2800 Himalayan glacial lakes and identified 49 lakes with potential flood volumes over 10 million m3.

Mobile Laser Scanning along Dieppe coastal cliffs: reliability of the acquired point clouds applied to rockfall assessments

NASA Astrophysics Data System (ADS)

Michoud, Clément; Carrea, Dario; Augereau, Emmanuel; Cancouët, Romain; Costa, Stéphane; Davidson, Robert; Delacourt, Chirstophe; Derron, Marc-Henri; Jaboyedoff, Michel; Letortu, Pauline; Maquaire, Olivier

2013-04-01

Dieppe coastal cliffs, in Normandy, France, are mainly formed by sub-horizontal deposits of chalk and flintstone. Largely destabilized by an intense weathering and the Channel sea erosion, small and large rockfalls are regularly observed and contribute to retrogressive cliff processes. During autumn 2012, cliff and intertidal topographies have been acquired with a Terrestrial Laser Scanner (TLS) and a Mobile Laser Scanner (MLS), coupled with seafloor bathymetries realized with a multibeam echosounder (MBES). MLS is a recent development of laser scanning based on the same theoretical principles of aerial LiDAR, but using smaller, cheaper and portable devices. The MLS system, which is composed by an accurate dynamic positioning and orientation (INS) devices and a long range LiDAR, is mounted on a marine vessel; it is then possible to quickly acquire in motion georeferenced LiDAR point clouds with a resolution of about 15 cm. For example, it takes about 1 h to scan of shoreline of 2 km long. MLS is becoming a promising technique supporting erosion and rockfall assessments along the shores of lakes, fjords or seas. In this study, the MLS system used to acquire cliffs and intertidal areas of the Cap d'Ailly was composed by the INS Applanix POS-MV 320 V4 and the LiDAR Optech Ilirs LR. On the same day, three MLS scans with large overlaps (J1, J21 and J3) have been performed at ranges from 600 m at 4 knots (low tide) up to 200 m at 2.2 knots (up tide) with a calm sea at 2.5 Beaufort (small wavelets). Mean scan resolutions go from 26 cm for far scan (J1) to about 8.1 cm for close scan (J3). Moreover, one TLS point cloud on this test site has been acquired with a mean resolution of about 2.3 cm, using a Riegl LMS Z390i. In order to quantify the reliability of the methodology, comparisons between scans have been realized with the software Polyworks™, calculating shortest distances between points of one cloud and the interpolated surface of the reference point cloud. A MatLab™ routine was also written to extract interesting statistics. First, mean distances between points of the reference point clouds (J21) and its interpolated surface are about 0.35 cm with a standard deviation of 15 cm; errors introduced during the surface interpolation step, especially in vegetated areas, may explain those differences. Then, mean distances between J1's points (resp. J3) and the J21's reference surface are about 4 cm (resp. -17 cm) with a standard deviation of 53 cm (resp. 55 cm). After a best fit alignment of J1 and J3 on J21, mean distances between J1 (resp. J3) and the J21's reference surface decrease to about 0.15 cm (resp. 1.6 cm) with a standard deviation of 41 cm (resp. 21 cm). Finally, mean distances between the TLS point clouds and the J21's reference surface are about 3.2 cm with a standard deviation of 26 cm. In conclusion, MLS devices are able to quickly scan long shoreline with a resolution up to about 10 cm. The precision of the acquired data is relatively small enough to investigate on geomorphological features of coastal cliffs. The ability of the MLS technique to detect and monitor small and large rockfalls will be investigated thanks to new acquisitions of the Dieppe cliffs in a close future and enhanced adapted post-processing steps.

Vallis Marineris

NASA Image and Video Library

2009-09-18

This Mars Odyssey image transects Candor Chasma and Melas Chasma. Many canyon features are clearly visible in the image, including the steep cliff faces, landslides, and layered canyon floor deposits.

Map showing scenic features and recreation facilities of the Salina quadrangle, Utah

USGS Publications Warehouse

Williams, Paul L.; Covington, Harry R.

1973-01-01

This map is intended as a guide for those who enjoy outdoor recreation in magnificent scenic settings.The Salina quadrangle lies in the heart of the Colorado Plateau, a sparsely populated land of unique and outstanding scenic beauty. The eastern half of the quadrangle is a great desert, partly blanketed by sand dunes, but  mostly an area of badlands multicolored cliffs and benches of virtually barren rock, and deeply incised canyons. In the west half of the quadrangle, rugged tree-covered foothills flank high forested plateaus rimmed by cliffs. On these High Plateaus, dense coniferous forest is interspersed with wide grassy parks, grazed in summer by sheep and cattle. Valleys between the plateaus contain irrigated crop lands.

Controlled quantum secure direct communication by entanglement distillation or generalized measurement

NASA Astrophysics Data System (ADS)

Tan, Xiaoqing; Zhang, Xiaoqian

2016-05-01

We propose two controlled quantum secure communication schemes by entanglement distillation or generalized measurement. The sender Alice, the receiver Bob and the controllers David and Cliff take part in the whole schemes. The supervisors David and Cliff can control the information transmitted from Alice to Bob by adjusting the local measurement angles θ _4 and θ _3. Bob can verify his secret information by classical one-way function after communication. The average amount of information is analyzed and compared for these two methods by MATLAB. The generalized measurement is a better scheme. Our schemes are secure against some well-known attacks because classical encryption and decoy states are used to ensure the security of the classical channel and the quantum channel.

Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales) with a Proposed Infrageneric Classification

PubMed Central

Zhang, Xianchun; Xiang, Qiaoping

2015-01-01

The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL–F) and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I), Cheilanthopsis–Protowoodsia (clade II) and Woodsia s.s. (clade III). In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns. PMID:26348852

Saga of coal bed methane, Ignacio Blanco gas field, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyce, B.C.; Harr, C.L.; Burch, L.C.

1989-09-01

Prior to the 1977 discovery of the Cedar Hill Basal Fruitland pool (the first officially designated coal-bed methane field in the western US) 28.5 bcf of gas had been produced from Fruitland Formation coal seams in the Ignacio Blanco Fruitland-Pictured Cliffs field, Northern San Juan basin, Colorado. The discovery well for the field, Southern Ute D-1, was drilled and completed in 1951 on the Ignacio anticline, La Plata County, Colorado. Initial completion was attempted in the Pictured Cliffs Sandstone. The well was plugged back after making water from the Pictured Cliffs and was completed in the lower coal-bearing section ofmore » the Fruitland Formation. The well produced 487,333 mcf of gas in nine years and was abandoned in 1959 due to water encroachment. Additionally, 52 similarly completed Ignacio anticline Fruitland wells were abandoned by the early 1970s due to the nemesis of If it's starting to kick water, you're through. Under today's coal-bed methane technology and economics, Amoco has twinned 12 of the abandoned wells, drilled five additional wells, and is successfully dewatering and producing adsorbed methane from previously depleted coal sections of the Ignacio structure. Field-wide drilling activity in 1988 exceeded all previous annual levels, with coal-seam degasification projects leading the resurgence. Drilling and completion forecasts for 1989 surpass 1988 levels by 50%.« less

Individualized texting for adherence building (iTAB): improving antiretroviral dose timing among HIV-infected persons with co-occurring bipolar disorder.

PubMed

Moore, David J; Poquette, Amelia; Casaletto, Kaitlin B; Gouaux, Ben; Montoya, Jessica L; Posada, Carolina; Rooney, Alexandra S; Badiee, Jayraan; Deutsch, Reena; Letendre, Scott L; Depp, Colin A; Grant, Igor; Atkinson, J Hampton

2015-03-01

HIV+ persons with co-occurring bipolar disorder (HIV+/BD+) have elevated rates of medication nonadherence. We conducted a 30-day randomized controlled trial of a two-way, text messaging system, iTAB (n = 25), compared to an active comparison (CTRL) (n = 25) to improve antiretroviral (ARV) and psychotropic (PSY) adherence and dose timing. Both groups received medication adherence psychoeducation and daily texts assessing mood. The iTAB group additionally received personalized medication reminder texts. Participants responded to over 90 % of the mood and adherence text messages. Mean adherence, as assessed via electronic monitoring caps, was high and comparable between groups for both ARV (iTAB 86.2 % vs. CTRL 84.8 %; p = 0.95, Cliff's d = 0.01) and PSY (iTAB 78.9 % vs. CTRL 77.3 %; p = 0.43, Cliff's d = -0.13) medications. However, iTAB participants took ARVs significantly closer to their intended dosing time than CTRL participants (iTAB: 27.8 vs. CTRL: 77.0 min from target time; p = 0.02, Cliff's d = 0.37). There was no group difference on PSY dose timing. Text messaging interventions may represent a low-burden approach to improving timeliness of medication-taking behaviors among difficult-to-treat populations. The benefits of improved dose timing for long-term medication adherence require additional investigation.

The peregrine falcon in Arizona: Habitat utilization and management recommendations

USGS Publications Warehouse

Ellis, D.H.

1982-01-01

The peregrine falcon once bred in significant numbers in Arizona. Good documentation is available for specific breeding sites and an additional 20 general locations. This report, based on the published literature, an extensive personal contact survey, an aerial habitat inventory (over 124 hours air time), and ground visits to over 300 locations, provides information on habitat preferences and management practices which can contribute to the bird's survival. In seeking to identify the habitat preferences of the falcon, many site description factors were examined. Those traits which appeared common to most recent Arizona sites (and therefore most useful in evaluating habitat) were: elevation less than 9,000 feet, cliffs tall or very tall, cliffs extensive, topographic relief high, and surface water readily available. All recent sites are in extensive canyon systems or in extensive mountain ranges. Using a habitat evaluation key derived from the traits common to known breeding sites, all cliff regions in Arizona and the Navajo Indian Reservation were flown and evaluated for suitability. Nineteen falcon eyries located in subsequent ground visits were all in areas previously ranked acceptable or better. Many management alternatives are discussed: management of information on breeding sites, habitat preservation, controlling disruptive human activities, and enhancing productivity through the creation of suitable breeding ledges, providing pesticide free prey, or direct reintroductions. Given their privacy (and an increasingly pesticide free environment) the peregrine falcon will likely exist indefinitely in suitable areas across Arizona.

Erosion and Deposition in Schaeberle Crater

NASA Image and Video Library

2016-01-14

Schaeberle Crater is a large, heavily-infilled crater with many interesting features. This image NASA Mars Reconnaissance Orbiter spacecraft shows a window into the crater fill deposit, showcasing eroding bedrock and aeolian landforms. This pit is located near the geometric center of our image, making it a central pit crater. Central pit craters are thought to form from impact melt draining through subsurface cracks in the deepest part of the crater shortly following impact. A closeup image shows light-toned bedrock and a small cliff that appears to be weathering away. Below the cliff there are several different types of aeolian features, including ripples and transverse aeolian ridges (TAR). The sand that forms the small, bluish ripples may be weathering out of the cliff face, in contrast to the larger, light-toned TAR which are thought to be currently inactive. More of the TAR are visible in another closeup image. In this case, they are clearly covered by a dark, ripple-covered sand sheet. We have only imaged this location once, so it is impossible to determine whether or not the sand sheet is blowing in the wind. But due to repeated HiRISE imaging in other areas, active dunes are now known to be common across Mars and we can reasonably speculate that these dunes are moving, too. http://photojournal.jpl.nasa.gov/catalog/PIA20339

40 CFR 61.141 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., manufacturing, or fabricating operation. This does not include condensed, uncombined water vapor. Waste... such as cliffs, lakes or other large bodies of water, deep and wide ravines, and mountains. Remoteness...

40 CFR 61.141 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., manufacturing, or fabricating operation. This does not include condensed, uncombined water vapor. Waste... such as cliffs, lakes or other large bodies of water, deep and wide ravines, and mountains. Remoteness...

40 CFR 61.141 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., manufacturing, or fabricating operation. This does not include condensed, uncombined water vapor. Waste... such as cliffs, lakes or other large bodies of water, deep and wide ravines, and mountains. Remoteness...

77 FR 23710 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-20

..., Exelon Generation Company, LLC, Exelon Energy Company, Calvert Cliffs Nuclear Power Plant LLC, CER Generation, LLC, Commonwealth Edison Company, Constellation NewEnergy, Inc., CER Generation II, LLC...

Morphea

MedlinePlus

... a slightly depressed center with a well defined border described as "cliff-drop” in appearance. Linear morphea ( ... with furrow formation of the skin and underlying structures. The atrophy can be quite marked with involvement ...

Edge modulation of electronics and transport properties of cliff-edge phosphorene nanoribbons

NASA Astrophysics Data System (ADS)

Guo, Caixia; Wang, Tianxing; Xia, Congxin; Liu, Yufang

2017-12-01

Based on the first-principles calculations, we study the electronic structures and transport properties of cliff-like edge phosphorene nanoribbons (CPNRs), considering different types of edge passivation. The band structures of bare CPNRs possess the metallic features; while hydrogen (H), fluorine (F), chlorine (Cl) and oxygen (O) atoms-passivated CPNRs are semiconductor materials, and the band gap values monotonically decrease when the ribbon width increases. Moreover, the H and F-passivated CPNRs exhibit the direct band gap characteristics, while the Cl and O-passivated cases show the features of indirect band gap. In addition, the edge passivated CPNRs are more energetically stable than bare edge case. Meanwhile, our results also show that the transport properties of the CPNRs can be obviously influenced by the different edge passivation.

Short- and long-term thermo-erosion of ice-rich permafrost coasts in the Laptev Sea region

NASA Astrophysics Data System (ADS)

Günther, F.; Overduin, P. P.; Sandakov, A. V.; Grosse, G.; Grigoriev, M. N.

2013-06-01

Permafrost coasts in the Arctic are susceptible to a variety of changing environmental factors all of which currently point to increasing coastal erosion rates and mass fluxes of sediment and carbon to the shallow arctic shelf seas. Rapid erosion along high yedoma coasts composed of Ice Complex permafrost deposits creates impressive coastal ice cliffs and inspired research for designing and implementing change detection studies for a long time, but continuous quantitative monitoring and a qualitative inventory of coastal thermo-erosion for large coastline segments is still lacking. Our goal is to use observations of thermo-erosion along the mainland coast of the Laptev Sea, in eastern Siberia, to understand how it depends on coastal geomorphology and the relative contributions of water level and atmospheric drivers. We compared multi-temporal sets of orthorectified satellite imagery from 1965 to 2011 for three segments of coastline ranging in length from 73 to 95 km and analyzed thermo-denudation (TD) along the cliff top and thermo-abrasion (TA) along the cliff bottom for two nested time periods: long-term rates (the past 39-43 yr) and short-term rates (the past 1-4 yr). The Normalized Difference Thermo-erosion Index (NDTI) was used as a proxy to qualitatively describe the relative proportions of TD and TA. Mean annual erosion rates at all three sites were higher in recent years (-5.3 ± 1.3 m a-1) than over the long-term mean (-2.2 ± 0.1 m a-1). The Mamontov Klyk coast exhibits primarily spatial variations of thermo-erosion, while intrasite-specific variations caused by local relief were strongest at the Buor Khaya coast, where the slowest long-term rates of around -0.5 ± 0.1 m a-1 were observed. The Oyogos Yar coast showed continuously rapid erosion up to -6.5 ± 0.2 m a-1. In general, variable characteristics of coastal thermo-erosion were observed not only between study sites and over time, but also within single coastal transects along the cliff profile. Varying intensities of cliff bottom and top erosion are leading to diverse qualities of coastal erosion that have different impacts on coastal mass fluxes. The different extents of Ice Complex permafrost degradation within our study sites turned out to influence not only the degree of coupling between TD and TA, and the magnitude of effectively eroded volumes, but also the quantity of organic carbon released to the shallow Laptev Sea from coastal erosion, which ranged on a long-term from 88 ± 21 to 800 ± 61 t per km coastline per year and will correspond to considerably higher amounts, if recently observed more rapid coastal erosion rates prove to be persistent.

Geologic map of the Tuba City 30' x 60' quadrangle, Coconino County, northern Arizona

USGS Publications Warehouse

Billingsley, George H.; Stoffer, Philip W.; Priest, Susan S.

2012-01-01

The Tuba City 30’ x 60’ quadrangle encompasses approximately 5,018 km² (1,920 mi²) within Coconino County, northern Arizona. It is characterized by nearly flat lying to gently dipping sequences of Paleozoic and Mesozoic strata that overly tilted Precambrian strata or metasedimentary and igneous rocks that are exposed at the bottom of Grand Canyon. The Paleozoic rock sequences from Cambrian to Permian age are exposed in the walls of Grand Canyon, Marble Canyon, and Little Colorado River Gorge. Mesozoic sedimentary rocks are exposed in the eastern half of the quadrangle where resistant sandstone units form cliffs, escarpments, mesas, and local plateaus. A few Miocene volcanic dikes intrude Mesozoic rocks southwest, northwest, and northeast of Tuba City, and Pleistocene volcanic rocks representing the northernmost extent of the San Francisco Volcanic Field are present at the south-central edge of the quadrangle. Quaternary deposits mantle much of the Mesozoic rocks in the eastern half of the quadrangle and are sparsely scattered in the western half. Principal folds are the north-south-trending, east-dipping Echo Cliffs Monocline and the East Kaibab Monocline. The East Kaibab Monocline elevates the Kaibab, Walhalla, and Coconino Plateaus and parts of Grand Canyon. Grand Canyon erosion has exposed the Butte Fault beneath the east Kaibab Monocline, providing a window into the structural complexity of monoclines in this part of the Colorado Plateau. Rocks of Permian and Triassic age form the surface bedrock of Marble Plateau and House Rock Valley between the East Kaibab and Echo Cliffs Monoclines. The Echo Cliffs Monocline forms a structural boundary between the Marble Plateau to the west and the Kaibito and Moenkopi Plateaus to the east. Jurassic rocks of the Kaibito and Moenkopi Plateaus are largely mantled by extensive eolian sand deposits. A small part of the northeast-dipping Red Lake Monocline is present in the northeast corner of the quadrangle. A broad and gentle elongated anticline, the Limestone Ridge Anticline, forms the crest of Marble Plateau. Here, Paleozoic and Mesozoic strata generally dip less than 1° to 2° in all directions from a central high area along Limestone Ridge north of Bodaway Mesa and east of Cedar Ridge and The Gap. The Limestone Ridge Anticline plunges gently southeast toward the Painted Desert at the south edge of the quadrangle and northward toward Lees Ferry, Arizona, at the north-central edge of the quadrangle. The Tuba City Syncline is a very broad northwest-southeast-oriented-synclinal downwarp that parallels the Echo Cliffs Monocline north of Tuba City. The Preston Mesa Anticline is a small fold present on Kaibito Plateau north of Tuba City.

Thermal monitoring of a granitic exfoliation sheet and cliff in Yosemite Valley, California (USA)

NASA Astrophysics Data System (ADS)

Guerin, Antoine; Matasci, Battista; Collins, Brian D.; Stock, Greg M.; Derron, Marc-Henri; Jaboyedoff, Michel

2015-04-01

In recent years, new remote sensing techniques such as Terrestrial Laser Scanner (TLS) and Infrared Thermography (IRT) have been used in parallel for rock weathering and weakness detection in slope stability analysis. Nevertheless, the effects of thermal stresses on rock face deformation are still poorly quantified, especially for steep and inaccessible cliffs. To better understand how daily temperature fluctuations influence the behavior of exfoliation joints (i.e., fractures separating exfoliation sheets), we monitored a granitic exfoliation sheet in detail using TLS and IRT over a several day period and also compiled a single TLS-IRT thermal panorama of a larger nearby granitic cliff composed of hundreds to thousands of similar exfoliation sheets. The exfoliation sheet had been previously instrumented for 3.5 years beginning in May 2010 using crackmeters and temperature sensors (Collins and Stock, 2010 and 2012), thereby providing an important baseline to compare our IRT measurements. For several consecutive days, a series of infrared thermal images (collected every 20 min.) of the exfoliation flake (19 m by 4 m by 0.1 m) was taken with a long range IRISYS IRI 4040 thermal imager, as well as several ground-based LiDAR scans, collected at 4 mm point spacing. These pictures were draped on the TLS triangular meshes to quantify the lateral propagation of temperature during the warming and cooling periods. The evolution of vertical and horizontal temperature profiles was also investigated. Results show that the sheet edge undergoes the most significant temperature changes and that warming takes place from the inside part to the border of the flake; conversely cooling takes place from the outside-inwards. Furthermore, the comparison of point clouds indicates a maximum crack aperture of over 1 cm occurring in the afternoon (12:00 to 15:00), when temperatures are at their maximum. The thermal panoramic image of the cliff (600 m wide by 300 m tall) was created using over 100 stitched pictures and also draped on a TLS mesh to generate a 3D color model. This model shows the apparent temperatures measured according to position and surface orientation of the cliff. This rock wall has many recent rockfall scars with lighter colored rock surface; these scars appear as spots of lower temperature surrounded by warmer areas and may undergo increased stress related to the thermal variations. However, these first results must be verified by further testing using calibrated models to distinguish the effects of emissivity and thermal radiation. Subsequently, we plan to fix the thermal camera on a GigaPan EPIC Pro device to take sequences of panoramas during rock cooling and heating and to perform additional investigation on air and water propagation in fractured zones.

1. Southeast elevation of Oil House showing loading platform. ...

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

1. Southeast elevation of Oil House showing loading platform. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

5. Transmission wheel on southeast wall of Oil House. ...

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

5. Transmission wheel on southeast wall of Oil House. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

DTV Cliff Effect Assistance Act of 2009

THOMAS, 111th Congress

Rep. Michaud, Michael H. [D-ME-2

2009-06-16

House - 06/17/2009 Referred to the Subcommittee on Communications, Technology, and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Recent Advances in our Understanding of Debris-covered Glacier Response to Climate

NASA Astrophysics Data System (ADS)

Pellicciotti, F.

2016-12-01

Debris-covered glaciers are relevant in many mountainous regions, but both modelling and observational studies are less numerous compared to those on traditional "clean" glaciers. A number of conjectures about their behaviour and response to climate have been made. First, it is assumed that in a warming climate debris cover would increase because of slope instability and increased meltout of englacial debris. Second, large-scale remote sensing studies have suggested that their thinning rates are comparable to those of debris-free glaciers, in spite of the insulating effect of a debris mantle. This apparent anomaly has been explained conceptually through high rates of energy absorption at supraglacial cliffs and ponds, but no evidence for this argument exists at the glacier scale. We validate each of these assumptions based on numerical modelling, analysis of satellite data and field observations from High Mountain Asia and the well monitored Langtang catchment in the Himalaya, in particular. First, no change in debris-covered area is apparent for regions of stable or positive mass balance such as the Karakoram, in line with the reasoning that sustained negative mass balance triggers an increase in debris. Second, results from an ensemble of DEM differences for the Langtang glaciers show that thinning rates of the debris-covered glaciers are not equivalent to those of the debris-free glaciers, contradicting results from the large-scale studies. However, thinning rates are higher than would be expected for a debris-covered surface, and can be explained through physically-based models of cliffs and lakes. These dynamic features form on low-gradient glacier sections between stagnant and dynamic zones, evolve in time and can survive or disappear depending on their characteristics. Ablation from cliffs and lakes is very high and can account between 10 to 30% of mass losses from the glaciers, despite covering a small percentage of the glacier area. Among the mechanisms controlling their persistence and relationship to climate, a key finding is that coupling of cliffs and ponds is a prerequisite for their long term survival. Our study provides a significant step towards a better understanding of the response of debris-covered glaciers to climate change, and highlights avenues of future research.

Hydrologic reconnaissance of the Wasatch Plateau-Book Cliffs coal-fields area, Utah

USGS Publications Warehouse

Waddell, Kidd M.; Contratto, P. Kay; Sumsion, C.T.; Butler, John R.

1981-01-01

Data obtained during a hydrologic reconnaissance in 1975-77 in the Wasatch Plateau-Book Cliffs coal-fields area of Utah were correlated with existing long-term data. Maps were prepared showing average precipitation, average streamflow, stream temperature, ground- and surface-water quality, sediment yield, and geology. Recommendations were made for additional study and suggested approaches for continued monitoring in the coalfields areas.moDuring the 1931-75 water years, the minimum discharges for the five major streams that head in the area ranged from about 12,000 to 26,000 acre-feet per year, and the maximum discharges ranged from about 59,000 to 315,000 acre-feet per year. Correlations indicate that 3 years of low-flow records at stream sites in the Wasatch Plateau would allow the development of relationships with long-term sites that can be used to estimate future low-flow records within a standard error of about 20 percent.Most water-quality degradation in streams occurs along the flanks of the Wasatch Plateau and Book Cliffs. In the uplands, dissolved-solids concentrations generally ranged from less than 100 to about 250 milligrams per liter, and in the lowlands, the concentrations ranged from about 250 to more than 6,000 milligrams per liter.Most springs in the Wasatch Plateau and Book Cliffs discharge from the Star Point Sandstone or younger formations, and the water generally contains less than about 1,000 milligrams per liter of dissolved solids. The discharges of 65 springs ranged from about 0.2 to 200 gallons per minute. The Blackhawk Formation, which is the principal coal-bearing formation, produces water in many of the mines. The dissolved-solids concentration in water discharging from springs and mines in the Blackhawk ranged from about 60 to 800 milligrams per liter.In the lowland areas, the Ferron Sandstone Member of the Maneos Shale appears to have the most potential for subsurface development of water of suitable chemical quality for human consumption. Three wells in the Ferron yielded water with dissolved-solids concentrations ranging from about 650 to 1,230 milligrams per liter.

Iceberg Ploughmarks Indicate Past Rapid Iceberg Calving and Retreat of Pine Island-Thwaites Ice Stream due to Marine Ice-Cliff Instability Processes

NASA Astrophysics Data System (ADS)

Wise, M.; Dowdeswell, J. A.; Larter, R. D.; Jakobsson, M.

2016-12-01

Seafloor ploughmarks provide evidence of past and present iceberg dimensions and drift direction. Today, Pine Island and Thwaites glaciers, which account for 35% of mass loss from the West Antarctic Ice Sheet (WAIS), calve mainly large, tabular icebergs, which, when grounded, produce `toothcomb-like' multi-keeled ploughmarks. High-resolution multi-beam swath bathymetry of the mid-shelf Pine Island Trough and adjacent banks, reveals many linear-curvilinear depressions interpreted as iceberg-keel ploughmarks, the majority of which are single-keeled in form. From measurements of ploughmark planform and cross-sections, we find iceberg calving from the palaeo-Pine Island-Thwaites Ice Stream was not characterised by small numbers of large, tabular icebergs, but instead, by a large number of `smaller' icebergs with v-shaped keels. Geological evidence of ploughmark form and water-depth distribution indicates calving-margin thicknesses ( 950 m) and subaerial ice-cliff elevations ( 100 m) equivalent to the theoretical threshold recently predicted to trigger ice-cliff structural collapse through Marine Ice Cliff Instability (MICI) processes. Significantly, our proposed period of iceberg ploughing predates the early Holocene climate optimum, and likely occurred in an absence of widespread surface melt. We therefore provide the first observational evidence of rapid retreat of the Palaeo-Pine Island-Thwaites ice stream from the crest of a large, mid-shelf sedimentary depocentre or grounding-zone wedge, to a restabilising position 112 km offshore of the December 2013 calving line, driven by MICI processes commencing 12.3 cal. ka BP. We emphasise the effective operation of MICI processes without extensive surface melt and induced hydrofracture, and conclude that such processes are unlikely to be confined to the past, given the steep, retrograde bed-slope which the modern grounding lines of Pine Island and Thwaites Glaciers are approaching, and the absence of any discernible restabilising features upstream of the modern grounding-zone. We expect MICI to contribute significantly to future ice retreat and sea-level rise under a warming climate, and emphasise the importance of its inclusion in future modelling studies.

Evidence of marine ice-cliff instability in Pine Island Bay from iceberg-keel plough marks

NASA Astrophysics Data System (ADS)

Wise, Matthew G.; Dowdeswell, Julian A.; Jakobsson, Martin; Larter, Robert D.

2017-10-01

Marine ice-cliff instability (MICI) processes could accelerate future retreat of the Antarctic Ice Sheet if ice shelves that buttress grounding lines more than 800 metres below sea level are lost. The present-day grounding zones of the Pine Island and Thwaites glaciers in West Antarctica need to retreat only short distances before they reach extensive retrograde slopes. When grounding zones of glaciers retreat onto such slopes, theoretical considerations and modelling results indicate that the retreat becomes unstable (marine ice-sheet instability) and thus accelerates. It is thought that MICI is triggered when this retreat produces ice cliffs above the water line with heights approaching about 90 metres. However, observational evidence confirming the action of MICI has not previously been reported. Here we present observational evidence that rapid deglacial ice-sheet retreat into Pine Island Bay proceeded in a similar manner to that simulated in a recent modelling study, driven by MICI. Iceberg-keel plough marks on the sea-floor provide geological evidence of past and present iceberg morphology, keel depth and drift direction. From the planform shape and cross-sectional morphologies of iceberg-keel plough marks, we find that iceberg calving during the most recent deglaciation was not characterized by small numbers of large, tabular icebergs as is observed today, which would produce wide, flat-based plough marks or toothcomb-like multi-keeled plough marks. Instead, it was characterized by large numbers of smaller icebergs with V-shaped keels. Geological evidence of the form and water-depth distribution of the plough marks indicates calving-margin thicknesses equivalent to the threshold that is predicted to trigger ice-cliff structural collapse as a result of MICI. We infer rapid and sustained ice-sheet retreat driven by MICI, commencing around 12,300 years ago and terminating before about 11,200 years ago, which produced large numbers of icebergs smaller than the typical tabular icebergs produced today. Our findings demonstrate the effective operation of MICI in the past, and highlight its potential contribution to accelerated future retreat of the Antarctic Ice Sheet.

43 CFR 37.4 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... described in this part. (b) Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge, including any cave resource...

6. Interior view of tanks on first floor, looking east. ...

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

6. Interior view of tanks on first floor, looking east. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

7. Row of pumps against first floor interior west wall. ...

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

7. Row of pumps against first floor interior west wall. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

Publications - SR 58 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

; Arsenopyrite; Barite; Base Metals; Big Delta; Bismuth; Chalcopyrite; Chicken Pluton; Cliff Mine; Coal ; Delta Junction; Diamond Drilling; Diamonds; Donlin Creek; Drift Mine; Drilling; Duke Island; Economic

43 CFR 37.4 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... described in this part. (b) Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge, including any cave resource...

43 CFR 37.4 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... described in this part. (b) Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge, including any cave resource...

43 CFR 37.4 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... described in this part. (b) Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge, including any cave resource...

43 CFR 37.4 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... described in this part. (b) Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge, including any cave resource...

4. Electric motor and transmission wheel on southeast wall of ...

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

4. Electric motor and transmission wheel on southeast wall of Oil House. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

DTV Cliff Effect Assistance Act of 2009

THOMAS, 111th Congress

Sen. Snowe, Olympia J. [R-ME

2009-04-27

Senate - 04/27/2009 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

77 FR 34093 - License Renewal for Calvert Cliffs Nuclear Power Plant, LLC's

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... quality; water quality and use; geology and soils; ecology; noise; historical and cultural; scenic and... significantly affect the quality of the human environment. Therefore, preparation of an environmental impact...

300 Kilometer Long Scarp

NASA Image and Video Library

2000-08-06

A scarp, or cliff, extends diagonally from upper left to lower right in this picture of Mercury taken by NASA Mariner 10. The structures are believed to be formed by the compressive forces due to crustal shortening.

75 FR 54610 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

..., Handsome Lake Energy, LLC, Constellation Energy Commodities Group M, CER Generation, LLC, Calvert Cliffs Nuclear Power Plant, LLC, CER Generation II, LLC. Description: Notice of change in status and Q2 2010 land...

White Cliffs: Operating Experience

NASA Technical Reports Server (NTRS)

Kaneff, S.

1984-01-01

The fourteen dish white cliffs solar power station area is remote and subject to extreme environmental conditions, solution of the associated problems required careful and thoughtful attention and the application of resources. Notwithstanding the wide range and harshness of conditions, the difficulties caused by remoteness and the lack of a technological base and the need for relatively rapid demonstration of success, the project has had a very positive outcome. Qualitative and quantitative information and lessons are now available to enable considerable simplifications to be made for a new system, reducing both hardware and operation and maintenance costs. Experience and lessons are presented, particularly in relation to: system performance in various environmental conditions; design philosophies for collectors, the array, control systems, engine and plant; operation and maintenance strategies and cost reducing possibilities. Experience so far gives encouragement for the future of such paraboloidal dish systems in appropriate areas.

Patent cliff mitigation strategies: giving new life to blockbusters.

PubMed

Kakkar, Ashish Kumar

2015-01-01

With several blockbuster drugs on the brink of another significant patent expiry cliff, innovator pharmaceutical firms are at risk of losing billions of dollars in sales to generic competition. With issues such as staggering R&D costs, reduced productivity and increasing governmental emphasis on pharmacoeconomics, timely planning and implementation of product lifecycle management strategies is becoming indispensable. A variety of strategies designed to mitigate the post-patent expiry revenue loss exist. These approaches range from fairly straightforward measures, such as strategic price cuts and launching own or authorized generics, to complex and lengthy ones, such as new formulations and indications that require companies to reinvent their pharmaceuticals. As patent expiries loom and product pipelines continue to remain thin, proactive planning for generic entry will be critical for pharma companies to drive growth and earnings in a sustainable manner.

Assessing rockfall susceptibility in steep and overhanging slopes using three-dimensional analysis of failure mechanisms

USGS Publications Warehouse

Matasci, Battista; Stock, Greg M.; Jaboyedoff, Michael; Carrea, Dario; Collins, Brian D.; Guérin, Antoine; Matasci, G.; Ravanel, L.

2018-01-01

Rockfalls strongly influence the evolution of steep rocky landscapes and represent a significant hazard in mountainous areas. Defining the most probable future rockfall source areas is of primary importance for both geomorphological investigations and hazard assessment. Thus, a need exists to understand which areas of a steep cliff are more likely to be affected by a rockfall. An important analytical gap exists between regional rockfall susceptibility studies and block-specific geomechanical calculations. Here we present methods for quantifying rockfall susceptibility at the cliff scale, which is suitable for sub-regional hazard assessment (hundreds to thousands of square meters). Our methods use three-dimensional point clouds acquired by terrestrial laser scanning to quantify the fracture patterns and compute failure mechanisms for planar, wedge, and toppling failures on vertical and overhanging rock walls. As a part of this work, we developed a rockfall susceptibility index for each type of failure mechanism according to the interaction between the discontinuities and the local cliff orientation. The susceptibility for slope parallel exfoliation-type failures, which are generally hard to identify, is partly captured by planar and toppling susceptibility indexes. We tested the methods for detecting the most susceptible rockfall source areas on two famously steep landscapes, Yosemite Valley (California, USA) and the Drus in the Mont-Blanc massif (France). Our rockfall susceptibility models show good correspondence with active rockfall sources. The methods offer new tools for investigating rockfall hazard and improving our understanding of rockfall processes.

Identification of potential rockfall source areas at a regional scale using a DEM-based geomorphometric analysis

NASA Astrophysics Data System (ADS)

Loye, A.; Jaboyedoff, M.; Pedrazzini, A.

2009-10-01

The availability of high resolution Digital Elevation Models (DEM) at a regional scale enables the analysis of topography with high levels of detail. Hence, a DEM-based geomorphometric approach becomes more accurate for detecting potential rockfall sources. Potential rockfall source areas are identified according to the slope angle distribution deduced from high resolution DEM crossed with other information extracted from geological and topographic maps in GIS format. The slope angle distribution can be decomposed in several Gaussian distributions that can be considered as characteristic of morphological units: rock cliffs, steep slopes, footslopes and plains. A terrain is considered as potential rockfall sources when their slope angles lie over an angle threshold, which is defined where the Gaussian distribution of the morphological unit "Rock cliffs" become dominant over the one of "Steep slopes". In addition to this analysis, the cliff outcrops indicated by the topographic maps were added. They contain however "flat areas", so that only the slope angles values above the mode of the Gaussian distribution of the morphological unit "Steep slopes" were considered. An application of this method is presented over the entire Canton of Vaud (3200 km2), Switzerland. The results were compared with rockfall sources observed on the field and orthophotos analysis in order to validate the method. Finally, the influence of the cell size of the DEM is inspected by applying the methodology over six different DEM resolutions.

Coastal erosion as a source of mercury into the marine environment along the Polish Baltic shore.

PubMed

Bełdowska, Magdalena; Jędruch, Agnieszka; Łęczyński, Leszek; Saniewska, Dominika; Kwasigroch, Urszula

2016-08-01

The climate changes in recent years in the southern Baltic have been resulting in an increased frequency of natural extreme phenomena (i.e. storms, floods) and intensification of abrasion processes, which leads to introduction of large amounts of sedimentary deposits into the marine environment. The aim of this study was to determine the mercury load introduced to the Baltic Sea with deposits crumbling off the cliffs-parts of the coast that are the most exposed to abrasion. The studies were carried out close to five cliffs located on the Polish coast in the years 2011-2014. The results show that coastal erosion could be an important Hg source into the marine environment. This process is the third most important route, after riverine and precipitation input, by which Hg may enter the Gulf of Gdańsk. In the Hg budget in the gulf, the load caused by erosion (14.3 kg a(-1)) accounted for 80 % of the wet deposition and was 50 % higher than the amount of mercury introduced with dry deposition. Although the Hg concentration in the cliff deposits was similar to the natural background, due to their large mass, this problem could be significant. In addition, the preliminary studies on the impact of coastal erosion on the Hg level in the marine ecosystem have shown that this process may be one of the Hg sources into the trophic chain.

Detection probability of cliff-nesting raptors during helicopter and fixed-wing aircraft surveys in western Alaska

USGS Publications Warehouse

Booms, T.L.; Schempf, P.F.; McCaffery, B.J.; Lindberg, M.S.; Fuller, M.R.

2010-01-01

We conducted repeated aerial surveys for breeding cliff-nesting raptors on the Yukon Delta National Wildlife Refuge (YDNWR) in western Alaska to estimate detection probabilities of Gyrfalcons (Falco rusticolus), Golden Eagles (Aquila chrysaetos), Rough-legged Hawks (Buteo lagopus), and also Common Ravens (Corvus corax). Using the program PRESENCE, we modeled detection histories of each species based on single species occupancy modeling. We used different observers during four helicopter replicate surveys in the Kilbuck Mountains and five fixed-wing replicate surveys in the Ingakslugwat Hills near Bethel, AK. During helicopter surveys, Gyrfalcons had the highest detection probability estimate (p^;p^ 0.79; SE 0.05), followed by Golden Eagles (p^=0.68; SE 0.05), Common Ravens (p^=0.45; SE 0.17), and Rough-legged Hawks (p^=0.10; SE 0.11). Detection probabilities from fixed-wing aircraft in the Ingakslugwat Hills were similar to those from the helicopter in the Kilbuck Mountains for Gyrfalcons and Golden Eagles, but were higher for Common Ravens (p^=0.85; SE 0.06) and Rough-legged Hawks (p^=0.42; SE 0.07). Fixed-wing aircraft provided detection probability estimates and SEs in the Ingakslugwat Hills similar to or better than those from helicopter surveys in the Kilbucks and should be considered for future cliff-nesting raptor surveys where safe, low-altitude flight is possible. Overall, detection probability varied by observer experience and in some cases, by study area/aircraft type.

Estimating rates of coastal cliff erosion in a small island using terrestrial laser scanning and RPAS-based SfM-MVS photogrammetry

NASA Astrophysics Data System (ADS)

Hayakawa, Yuichi S.; Obanawa, Hiroyuki

2017-04-01

Rapid erosion of coastal cliffs has been historically observed to be more than 1 m/y in the outer Boso Peninsula area, eastern Japan. However, due to the modern work of coastal protection, the erosion rates of the coastal cliffs have significantly decreased. This caused coastal erosion in the nearby sand beach, to which sands had been supplied from the formerly eroded rocky coast. In order to assess the relationships between erosion and protection in both rocky and sandy coasts, quantitative evaluation of erosion rates by natural processes would be necessary. The Suzume-jima Island, a small coastal island in the outer Boso Peninsula area, is an ideal site, which is located outside of the coastal protection and natural processes of erosion can still be observed. Here we carried out multiple measurements of the entire shape of the island using remotely piloted aerial system (RPAS) and structure-from-motion multi-view stereo (SfM-MVS) photogrammetry. Terrestrial laser scanning is also performed for the accuracy assessment. The high-frequency (3 times a year) and high-resolution (cm) measurements of the small island for 3 years revealed spatially variable rockfalls and wave erosion, whose volume of mass has been quantitatively revealed from the 3-D point cloud obtained. The relatively short-term measurements are also compared with the long-term 2-D topographic changes in the island by aerial photographs for 50 years.

Cooperative Exploration of Rough Martian Terrains with the "Scorpion" Legged Robot as an Adjunct to a Rover.

NASA Technical Reports Server (NTRS)

Colombano, Silvano P.; Kirchner, Frank; Spenneberg, Dirk; Starman, Jared; Hanratty, James; Kovsmeyer, David (Technical Monitor)

2003-01-01

NASA needs autonomous robotic exploration of difficult (rough and/or steep) scientifically interesting Martian terrains. Concepts involving distributed autonomy for cooperative robotic exploration are key to enabling new scientific objectives in robotic missions. We propose to utilize a legged robot as an adjunct scout to a rover for access to difficult - scientifically interesting - terrains (rocky areas, slopes, cliffs). Our final mission scenario involves the Ames rover platform "K9" and Scorpion acting together to explore a steep cliff, with the Scorpion robot rappelling down using the K9 as an anchor as well as mission planner and executive. Cooperation concepts, including wheeled rappelling robots have been proposed before. Now we propose to test the combined advantages of a wheeled vehicle with a legged scout as well as the advantages of merging of high level planning and execution with biologically inspired, behavior based robotics. We propose to use the 8-legged, multifunctional autonomous robot platform Scorpion that is currently capable of: Walking on different terrains (rocks, sand, grass, ...). Perceiving its environment and modifying its behavioral pattern accordingly. These capabilities would be extended to enable the Scorpion to: communicate and cooperate with a partner robot; climb over rocks, rubble piles, and objects with structural features. This will be done in the context of exploration of rough terrains in the neighborhood of the rover, but inaccessible to it, culminating in the added capability of rappelling down a steep cliff for both vertical and horizontal terrain observation.

Geotechnical properties of cemented sands in steep slopes

USGS Publications Warehouse

Collins, B.D.; Sitar, N.

2009-01-01

An investigation into the geotechnical properties specific to assessing the stability of weakly and moderately cemented sand cliffs is presented. A case study from eroding coastal cliffs located in central California provides both the data and impetus for this study. Herein, weakly cemented sand is defined as having an unconfined compressive strength (UCS) of less than 100 kPa, and moderately cemented sand is defined as having UCS between 100 and 400 kPa. Testing shows that both materials fail in a brittle fashion and can be modeled effectively using linear Mohr-Coulomb strength parameters, although for weakly cemented sands, curvature of the failure envelope is more evident with decreasing friction and increasing cohesion at higher confinement. Triaxial tests performed to simulate the evolving stress state of an eroding cliff, using a reduction in confinement-type stress path, result in an order of magnitude decrease in strain at failure and a more brittle response. Tests aimed at examining the influence of wetting on steep slopes show that a 60% decrease in UCS, a 50% drop in cohesion, and 80% decrease in the tensile strength occurs in moderately cemented sand upon introduction to water. In weakly cemented sands, all compressive, cohesive, and tensile strength is lost upon wetting and saturation. The results indicate that particular attention must be given to the relative level of cementation, the effects of groundwater or surficial seepage, and the small-scale strain response when performing geotechnical slope stability analyses on these materials. ?? 2009 ASCE.

Mummy Lake: An unroofed ceremonial structure within a large-scale ritual landscape

USGS Publications Warehouse

Benson, Larry V.; Griffin, Eleanor R.; Stein, J.R.; Friedman, R. A.; Andrae, S. W.

2014-01-01

The structure at Mesa Verde National Park known historically as Mummy Lake and more recently as Far View Reservoir is not part of a water collection, impoundment, or redistribution system. We offer an alternative explanation for the function of Mummy Lake. We suggest that it is an unroofed ceremonial structure, and that it serves as an essential component of a Chacoan ritual landscape. A wide constructed avenue articulates Mummy Lake with Far View House and Pipe Shrine House. The avenue continues southward for approximately 6 km where it apparently divides connecting with Spruce Tree House and Sun Temple/Cliff Palace. The avenue has previously been interpreted as an irrigation ditch fed by water impounded at Mummy Lake; however, it conforms in every respect to alignments described as Chacoan roads. Tree-ring dates indicate that the construction of Spruce Tree House and Cliff Palace began about A.D. 1225, roughly coincident with the abandonment of the Far View community. This pattern of periodically relocating the focus of an Anasazi community by retiring existing ritual structures and linking them to newly constructed facilities by means of broad avenues was first documented by Fowler and Stein (1992) in Manuelito Canyon, New Mexico. Periods of intense drought appear to have contributed to the relocation of prehistoric Native Americans from the Far View group to Cliff Palace/Spruce Tree House in the mid-13th century and eventually to the abandonment of all Anasazi communities in southwestern Colorado in the late-13th century.

Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling

NASA Astrophysics Data System (ADS)

Török, Ákos; Barsi, Árpád; Bögöly, Gyula; Lovas, Tamás; Somogyi, Árpád; Görög, Péter

2018-02-01

Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System) was used to collect images which were processed by Pix4D mapper (structure from motion technology) to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS) with the use of seven ground control points. The obtained digital surface model (DSM) was processed (vegetation removal) and the derived digital terrain model (DTM) allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method). Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE-WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS).

North Polar Cliff

NASA Technical Reports Server (NTRS)

2006-01-01

This full HiRISE image shows a cliff-face that has been eroded into the ice-rich polar layered deposits at the head of the large canyon, Chasma Boreale. In a similar way to layers in the Earth's ice caps, these Martian layers are thought to record variations in climate, which makes them very interesting to scientists. This particular cliff-face is several hundred meters high and the layers exposed here are the deepest (and so the oldest) in the polar layered deposits. The lower layers exposed in this scarp appear to be rich in dark sand, and erosion of these layers has produced the sand dunes that cover sections of this cliff-face. A close examination of the layers in the center of the image shows they have curved shapes and intersect each other. Scientists call this cross-bedding and it may indicate that these sandy layers were laid down as a large dunefield before being buried. At the bottom of the image, the floor of Chasma Boreale in this area appears to have been swept clean of sandy material. There is a complex history of erosion and deposition of material at this location. On the right of the image one can see a smooth material that covers the lower layers and which must have been deposited after the main cliff face was initially eroded. Closer to the center of the image, this smooth mantling material is in turn being eroded away to once again expose the layers beneath it.

Image PSP_001334_2645 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 8, 2006. The complete image is centered at 84.4 degrees latitude, 343.5 degrees East longitude. The range to the target site was 317.4 km (198.4 miles). At this distance the image scale ranges from 31.8 cm/pixel (with 1 x 1 binning) to 63.5 cm/pixel (with 2 x 2 binning). The image shown here has been map-projected to 25 cm/pixel. The image was taken at a local Mars time of 1:38 PM and the scene is illuminated from the west with a solar incidence angle of 67 degrees, thus the sun was about 23 degrees above the horizon. At a solar longitude of 132.3 degrees, the season on Mars is Northern Summer.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

Short and long-term thermo-erosion of ice-rich permafrost coasts in the Laptev Sea region

NASA Astrophysics Data System (ADS)

Günther, F.; Overduin, P. P.; Sandakov, A. V.; Grosse, G.; Grigoriev, M. N.

2013-02-01

Permafrost coasts in the Arctic are susceptible to a variety of changing environmental factors all of which currently point to increasing coastal erosion rates and mass fluxes of sediment and carbon to the shallow arctic shelf seas. Rapid erosion along high yedoma coasts composed of Ice Complex permafrost deposits creates impressive coastal ice cliffs and inspired research for designing and implementing change detection studies for a long time, but continuous quantitative monitoring and a qualitative inventory of coastal thermo-erosion for large coastline segments is still lacking. Our goal is to use observations of thermo-erosion along the mainland coast of the Laptev Sea in eastern Siberia to understand how erosion rates depend on coastal geomorphology and the relative contributions of waterline and atmospheric drivers to coastal thermo-erosion over the past 4 decades and in the past few years. We compared multitemporal sets of orthorectified satellite imagery from 1965 to 2011 for three segments of coastline with a length of 73 to 95 km each and analyzed thermo-denudation (TD) along cliff top and thermo-abrasion (TA) along cliff bottom for two nested time periods: long-term rates (the past 39-43 yr) and short term rates (the past 1-3 yr). The Normalized Difference Thermo-erosion Index (NDTI) was used as a proxy that qualitatively describes the relative proportions of TD and TA. Mean annual erosion rates at all three sites were higher in recent years (-5.3 ± 1.31 m a-1) than over the long term mean (-2.2 ± 0.13 m a-1). The Mamontov Klyk coast exhibit primarily spatial variations of thermo-erosion, while intrasite-specific variations were strongest at the Buor Khaya coast, where slowest long-term rates around -0.5 ± 0.08 m a-1 were observed. The Oyogos Yar coast showed continuously rapid erosion up to -6.5 ± 0.19 m a-1. In general, variable characteristics of coastal thermo-erosion were observed not only between study sites and over time, but also within single coastal transects along the cliff profile. Varying intensities of cliff bottom and top retreat are leading to diverse qualities of coastal erosion that have different impacts on coastal mass fluxes. The different extents of Ice Complex permafrost degradation within our study sites turned out to influence not only the degree of coupling between TD and TA, and the magnitude of effectively eroded volumes, but also the quantity of organic carbon released to the shallow Laptev Sea from coastal erosion, which ranged on a long-term from 88 ± 21.0 to 800 ± 61.1 t per km coastline per year and will correspond to considerably higher amounts, if recently observed more rapid coastal erosion rates prove to be persistent.

Ridges and Cliffs on Mercury Surface

NASA Image and Video Library

2008-01-20

A complex history of geological evolution is recorded in this frame from the Narrow Angle Camera NAC, part of the Mercury Dual Imaging System MDIS instrument, taken during NASA MESSENGER close flyby of Mercury on January 14, 2008.

Melas Chasma Deposits

NASA Image and Video Library

2003-01-09

Erosion of the interior layered deposits of Melas Chasma, part of the huge Valles Marineris canyon system, has produced cliffs with examples of spur and gulley morphology and exposures of finely layered sediments, as seen in this NASA Mars Odyssey image.

Preliminary study of the water-temperature regime of the North Santiam River downstream from Detroit and Big Cliff dams, Oregon

USGS Publications Warehouse

Laenen, Antonius

1985-01-01

A riverine-temperature model and associated data-collection system were developed to help the Corps of engineers determine cost benefits of selective-withdrawal structures for future use with dams on the Willamette River System. A U.S. Geological Survey Lagrangian reference frame, digital computer model was used to simulate stream temperatures on the North Santiam River downstream of the multipurpose Detroit dam and a reregulating dam (Big Cliff), from river mile 45.6 to 2.9. In simulation, only available air-temperature and windspeed information from a nearby National Weather Service station at Salem, Oregon were used. This preliminary investigation found that the model predicted mean daily temperatures to within 0.4 C standard deviation. Analysis of projected selective-withdrawal scenarios showed that the model has the sensitivity to indicate water-temperature changes 42.7 miles downstream on the North Santiam River. (USGS)

Selected hydrologic data, 1931-77, Wasatch Plateau-Book Cliffs coal-fields area, Utah

USGS Publications Warehouse

Waddell, K.M.; Vickers, H.L.; Upton, Robbin T.; Contratto, P. Kay

1978-01-01

The Wasatch Plateau-Book Cliffs coal-fields area in east-central Utah includes a significant part of the State's coal resources and is currently (1977) the most active coal-mining area in the State.This report presents data gathered by the U.S. Geological Survey as part of a hydrologic reconnaissance carried out during the period July 1975-September 1977 in cooperation with the U.S. Bureau of Land Management, as well as selected information for water-years 1931-75. The data were obtained in the field or from private, State, and other Federal agencies. The purpose of this report is to make the data available to those engaged in coal mining, to those assessing water resources that may possibly be affected by coal mining, and to supplement an interpretive report that will be published at a later date.

Dust Mantle Near Pavonis Mons

NASA Technical Reports Server (NTRS)

2003-01-01

MGS MOC Release No. MOC2-356, 10 May 2003

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a thick mantle of dust covering lava flows north of Pavonis Mons so well that the flows are no longer visible. Flows are known to occur here because of the proximity to the volcano, and such flows normally have a very rugged surface. Fine dust, however, has settled out of the atmosphere over time and obscured the flows from view. The cliff at the top of the image faces north (up), the cliff in the middle of the image faces south (down), and the rugged slope at the bottom of the image faces north (up). The dark streak at the center-left was probably caused by an avalanche of dust sometime in the past few decades. The image is located near 4.1oN, 111.3oW. Sunlight illuminates the scene from the right/lower right.

Obsidian hydration dates glacial loading?

USGS Publications Warehouse

Friedman, I.; Pierce, K.L.; Obradovich, J.D.; Long, W.D.

1973-01-01

Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming . The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

Obsidian hydration dates glacial loading?

PubMed

Friedman, I; Pierce, K L; Obradovich, J D; Long, W D

1973-05-18

Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming. The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

A giant Late Triassic ichthyosaur from the UK and a reinterpretation of the Aust Cliff ‘dinosaurian’ bones

PubMed Central

De la Salle, Paul; Massare, Judy A.; Gallois, Ramues

2018-01-01

The largest reported ichthyosaurs lived during the Late Triassic (~235–200 million years ago), and isolated, fragmentary bones could be easily mistaken for those of dinosaurs because of their size. We report the discovery of an isolated bone from the lower jaw of a giant ichthyosaur from the latest Triassic of Lilstock, Somerset, UK. It documents that giant ichthyosaurs persisted well into the Rhaetian Stage, and close to the time of the Late Triassic extinction event. This specimen has prompted the reinterpretation of several large, roughly cylindrical bones from the latest Triassic (Rhaetian Stage) Westbury Mudstone Formation from Aust Cliff, Gloucestershire, UK. We argue here that the Aust bones, previously identified as those of dinosaurs or large terrestrial archosaurs, are jaw fragments from giant ichthyosaurs. The Lilstock and Aust specimens might represent the largest ichthyosaurs currently known. PMID:29630618

Sedimentological indicators of paleoenvironments and siliciclastic stratigraphic sequences in some Miocene deposits of the Calvert Cliffs, southern Maryland

USGS Publications Warehouse

Shideler, G.L.

1994-01-01

Middle Miocene siliciclastic deposits comprising the Calvert Cliffs section at the Baltimore Gas and Electric Company's (BG&E) nuclear power plant site in southern Maryland were analyzed in terms of lithostratigraphy, sedimentary structures, and granulometric parameters, to interprete paleo-environments within a sequence-stratigraphic framework. In terms of sequence-stratigraphic models, the BG&E section can be interpreted as consisting of two genetic stratigraphic sequences (Galloway model), namely, a shelf sequence and an overlying deltaic sequence. Using the Exxon model, the section consists of two third-order (1-5 m.y. duration) depositional sequences. The stratigraphic sequences of the BG&E section reflect both relatively short-term eustatic transgressive events, as well as a long-term regressive trend with associated local deltation and coastal progradation. The regression probably signified a regional basinward shift of depocenters within the Salisbury embayment during Miocene time. -from Author

Factors controlling peat chemistry and vegetation composition in Sudbury peatlands after 30 years of pollution emission reductions.

PubMed

Barrett, Sophie E; Watmough, Shaun A

2015-11-01

The objective of this research was to assess factors controlling peat and plant chemistry, and vegetation composition in 18 peatlands surrounding Sudbury after more than 30 years of large (>95%) pollution emission reductions. Sites closer to the main Copper Cliff smelter had more humified peat and the surface horizons were greatly enriched in copper (Cu) and nickel (Ni). Copper and Ni concentrations in peat were significantly correlated with that in the plant tissue of Chamaedaphne calyculata. The pH of peat was the strongest determining factor for species richness, diversity, and community composition, although percent vascular plant cover was strongly negatively correlated with surface Cu and Ni concentrations in peat. Sphagnum frequency was also negatively related to peat Cu and Ni concentrations indicating sites close to Copper Cliff smelter remain adversely impacted by industrial activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cryo-conditioned rocky coast systems: A case study from Wilczekodden, Svalbard.

PubMed

Strzelecki, M C; Kasprzak, M; Lim, M; Swirad, Z M; Jaskólski, M; Pawłowski, Ł; Modzel, P

2017-12-31

This paper presents the results of an investigation into the processes controlling development of a cryo-conditioned rock coast system in Hornsund, Svalbard. A suite of nested geomorphological and geophysical methods have been applied to characterise the functioning of rock cliffs and shore platforms influenced by lithological control and geomorphic processes driven by polar coast environments. Electrical resistivity tomography (ERT) surveys have been used to investigate permafrost control on rock coast dynamics and reveal the strong interaction with marine processes in High Arctic coastal settings. Schmidt hammer rock tests, demonstrated strong spatial control on the degree of rock weathering (rock strength) along High Arctic rock coasts. Elevation controlled geomorphic zones are identified and linked to distinct processes and mechanisms, transitioning from peak hardness values at the ice foot through the wave and storm dominated scour zones to the lowest values on the cliff tops, where the effects of periglacial weathering dominate. Observations of rock surface change using a traversing micro-erosion meter (TMEM) indicate that significant changes in erosion rates occur at the junction between the shore platform and the cliff toe, where rock erosion is facilitated by frequent wetting and drying and operation of nivation and sea ice processes (formation and melting of snow patches and icefoot complexes). The results are synthesised to propose a new conceptual model of High Arctic rock coast systems, with the aim of contributing towards a unifying concept of cold region landscape evolution and providing direction for future research regarding the state of polar rock coasts. Copyright © 2017 Elsevier B.V. All rights reserved.

Recent storm and tsunami coarse-clast deposit characteristics, southeast Hawai'i

USGS Publications Warehouse

Richmond, B.M.; Watt, Sebastian; Buckley, M.; Jaffe, B.E.; Gelfenbaum, G.; Morton, R.A.

2011-01-01

Deposits formed by extreme waves can be useful in elucidating the type and characteristics of the depositional event. The study area on the southeast coast of the island of Hawaiʻi is characterized by the presence of geologically young basalts of known age that are mantled by recent wave-derived sedimentary deposits. The area has been impacted by large swells, storms and tsunamis over the last century, and in combination with known substrate ages makes this an ideal location to study recent deposits produced by such events. Three distinct coarse-clast deposit assemblages can be recognized based on clast size, composition, angularity, orientation, packing, elevation and inland distance of the deposit. These deposits are characterized as one of three types. 1) Gravel fields of isolated clasts, primarily boulder-size material, and scattered pockets of concentrated sand and gravel in topographic lows. 2) Shore-parallel and cuspate ridges composed mostly of rounded basalt gravel and sand with small amounts of carbonate detritus. The ridges range in height from about 1 to 3 m and are 10s of m wide. 3) Cliff-top deposits of scattered angular and sub-angular clasts along sea cliffs that are generally greater than 5 m elevation. The gravel fields are primarily of tsunami origin from either the 1975 Kalapana event, or a combination of the 1975 tsunami, and 1868 tsunami or earlier events. The ridge deposits are presently active and sediment continues to be added during high wave events. The cliff-top deposits contain evidence of deposition by both tsunami and storm processes and require further investigation.

New techniques to measure cliff change from historical oblique aerial photographs and structure-from-motion photogrammetry

USGS Publications Warehouse

Warrick, Jonathan; Ritchie, Andy; Adelman, Gabrielle; Adelman, Ken; Limber, Patrick W.

2017-01-01

Oblique aerial photograph surveys are commonly used to document coastal landscapes. Here it is shown that adequate overlap may exist in these photographic records to develop topographic models with Structure-from-Motion (SfM) photogrammetric techniques. Using photographs of Fort Funston, California, from the California Coastal Records Project, imagery were combined with ground control points in a four-dimensional analysis that produced topographic point clouds of the study area’s cliffs for 5 years spanning 2002 to 2010. Uncertainty was assessed by comparing point clouds with airborne LIDAR data, and these uncertainties were related to the number and spatial distribution of ground control points used in the SfM analyses. With six or more ground control points, the root mean squared errors between the SfM and LIDAR data were less than 0.30 m (minimum 1⁄4 0.18 m), and the mean systematic error was less than 0.10 m. The SfM results had several benefits over traditional airborne LIDAR in that they included point coverage on vertical- to-overhanging sections of the cliff and resulted in 10–100 times greater point densities. Time series of the SfM results revealed topographic changes, including landslides, rock falls, and the erosion of landslide talus along the Fort Funston beach. Thus, it was concluded that SfM photogrammetric techniques with historical oblique photographs allow for the extraction of useful quantitative information for mapping coastal topography and measuring coastal change. The new techniques presented here are likely applicable to many photograph collections and problems in the earth sciences.

Erosion rates of a small coastal island revealed by repeated measurements using TLS and UAS-SfM photogrammetry

NASA Astrophysics Data System (ADS)

Hayakawa, Y. S.; Obanawa, H.

2016-12-01

Due to the weak bedrock and constant wave erosion, sea cliffs along the outer Boso Peninsula, central Japan, have been eroded at ca. 1 m per year for centuries. Modern coastal protection work had significantly reduced the erosion rate, while this became a cause of limited supply of sands along beaches in this area. Among the almost complete protection, a small coastal island, so-called Suzume-Jima Island (70 km southeast of Tokyo), has not been protected, in which we can still observe processes of coastal cliff erosion at the original rate. We have performed multi-temporal (3 times a year), high-resolution (centimeters) topographic measurements of the small island for 3 years, using terrestrial laser scanning (TLS) and structure-from-motion multi-view stereo (SfM-MVS) photogrammetry with an unmanned aerial system (UAS). Landside of the island can be measured by both TLS and UAS, but the seaside could only be captured by UAS, therefore these data are combined to analyze the entire island morphology with a reasonable accuracy. Frequent, spatially variable wave erosion and rockfalls were observed during the measurement period. The dominant wave direction and geologic structure (joint location and orientation) may account for these differences. A severe notch development in the cliff suggests a possible formation of a sea cave through the island in the near future. The measured, short-term results were also compared with the longer-term development of the island shape, obtained by historical aerial photographs for 50 years.

Rockfall susceptibility mapping of Yosemite Valley (USA) using a high-resolution digital elevation model

NASA Astrophysics Data System (ADS)

Pannatier, A.; Oppikofer, T.; Jaboyedoff, M.; Stock, G. M.

2009-04-01

In Yosemite National Park (California, USA) rockfalls from the steep valley flanks are frequent (>600 documented events in 150 years) and threaten infrastructure in this popular tourist area. This study focuses on a methodology to map the susceptibility to rockfall initiation based on a high-resolution digital elevation model (HRDEM) obtained from aerial laser scanning (1 meter cell size). This methodology is based on geometric factors derived from the HRDEM, i.e., the steepness of the topography, the presence of joints or fractures enabling either a planar or a wedge failure mechanism, and a high denudation potential. The slope angle histogram computed using standard GIS routines was simulated using Gaussian distributions, which were attributed to different parts of the topography, i.e., the cliffs, the valley flanks and the valley floor. Slopes steeper than 36° are found to form cliffs and thus potentially lead to rockfalls. A morpho-structural analysis of the HRDEM was performed in Coltop3D software to determine the major discontinuity sets that shape the topography. Kinematic analyses were made for each of these 7 discontinuity sets in order to determine the HRDEM cells that fulfil the geometric criteria for a planar or wedge failure mechanism. Most of the cliffs in Yosemite Valley enable one or both of these failure mechanisms. The denudation potential was assessed using the sloping local base level (SLBL) concept. The SLBL defines a basal erosion surface and the above lying rock masses (up to 400 m in some of the vertical cliffs) are susceptible to erosion by mass wasting. A thickness of 20 m above the SLBL surface was chosen as lower limit for the denudation potential criterion. The HRDEM cells that satisfy 1, 2 or all 3 criteria are considered having low, moderate and high susceptibility to rockfall initiation. The areas with highest susceptibility (El Capitan, Glacier Point, Yosemite Falls and Half Dome) coincide well with post-glacial talus accumulations and historic rockfall sources. Compared to previous maps of potential rockfall sources that were mainly based on the slope angle criterion, this study provides a more refined analysis of potential rockfall sources and is useful for focussing detailed field investigations on those areas with high susceptibility.

Mapping the True 3D Morphology of Deep-Sea Canyons

NASA Astrophysics Data System (ADS)

Huvenne, V. A.; Masson, D.; Tyler, P. A.; Huehnerbach, V.

2010-12-01

The importance of submarine canyons as ecosystem hotspots and sediment transport pathways has been recognised for decades (e.g. Heezen et al., 1955; Vetter & Dayton, 1998). However, studying canyon systems in detail is a challenge, because of the complexity and steepness of the terrain. Acoustic surveys are hampered by side-echoes, while the high slope angles cause most types of sampling equipment, deployed from surface vessels, to fail. Ship-borne bathymetric surveys tend to represent the canyon topography in an overly smoothed way as a result of their limited resolution in deep water compared to the scale of the terrain variability. Moreover, it is clear that overhanging cliffs cannot be mapped correctly with traditional, downward looking multibeam echosounders. The increasing availability of underwater vehicles, however, opens new opportunities. During summer 2009, we mapped several submarine canyon habitats in detail, using the UK deep-water Remotely Operated Vehicle (ROV) ISIS. In particular, we developed a new methodology to map vertical cliffs and overhangs by placing the high-resolution Simrad SM2000 multibeam system of the ROV in a forward-looking position rather than in the traditional downward-looking configuration. The cliff morphology was then mapped by moving the ROV laterally in parallel passes at different depths. Repeating this approach at different distances from the cliff face, we obtained maps of varying resolution and extent. The low resolution maps provide an overview of the general geological framework, while individual strata and faunal colonies can be recognised on the highest resolution maps. Using point-cloud models, we combined the ship-borne bathymetry with the ROV-based data, in order to obtain a true 3D seabed morphology of the canyon study site, which can be used for fly-throughs, geomorphological analysis or habitat mapping. With this approach, we could visualise the spatial structure and density distribution of a unique and previously unknown cold-water coral reef, formed as a hanging garden under a 1600 m long and 120 m high overhanging wall, at 1350 m water depth in the Whittard Canyon, NE Atlantic margin. Heezen, B.C., Ewing, M. and Menzies, R. (1955). The influence of submarine turbidity currents on abyssal productivity. Oikos, 6, 170-182. Vetter, E.W. & Dayton, P.K. (1998). Macrofaunal communities within and adjacent to a detritus-rich submarine canyon system. Deep-Sea Research II, 45, 25-54.

Surficial Geologic Map of Mesa Verde National Park, Montezuma County, Colorado

USGS Publications Warehouse

Carrara, Paul E.

2012-01-01

Mesa Verde National Park in southwestern Colorado was established in 1906 to preserve and protect the artifacts and dwelling sites, including the famous cliff dwellings, of the Ancestral Puebloan people who lived in the area from about A.D. 550 to A.D. 1300. In 1978, the United Nations designated the park as a World Heritage Site. The geology of the park played a key role in the lives of these ancient people. For example, the numerous (approximately 600) cliff dwellings are closely associated with the Cliff House Sandstone of Late Cretaceous age, which weathers to form deep alcoves. In addition, the ancient people farmed the thick, red loess (wind-blown dust) deposits on the mesa tops, which because of its particle size distribution has good moisture retention properties. The soil in this loess cover and the seasonal rains allowed these people to grow their crops (corn, beans, and squash) on the broad mesa tops. Today, geology is still an important concern in the Mesa Verde area because the landscape is susceptible to various forms of mass movement (landslides, debris flows, rockfalls), swelling soils, and flash floods that affect the park's archeological sites and its infrastructure (roads, septic systems, utilities, and building sites). The map, which encompasses an area of about 100 mi2 (260 km2), includes all of Mesa Verde National Park, a small part of the Ute Mountain Indian Reservation that borders the park on its southern and western sides, and some Bureau of Land Management and privately owned land to the north and east. Surficial deposits depicted on the map include: artificial fills, alluvium of small ephemeral streams, alluvium deposited by the Mancos River, residual gravel on high mesas, a combination of alluvial and colluvial deposits, fan deposits, colluvial deposits derived from the Menefee Formation, colluvial deposits derived from the Mancos Shale, rockfall deposits, debris flow deposits, earthflow deposits, translational and rotational landslide deposits, rock rubble deposits, and loess. Bedrock units depicted on the map include the Cliff House Sandstone, Menefee Formation, Point Lookout Sandstone, and Mancos Shale all of Late Cretaceous age. In addition, minette dikes, of Oligocene age, found at several locations in the park are depicted on the map. Descriptions, including associated hazards and resources as used by the Ancestral Puebloans, are given for all map units.

Vascular Plant and Vertebrate Inventory of Gila Cliff Dwellings National Monument

USGS Publications Warehouse

Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Docherty, Kathleen; Anning, Pamela

2006-01-01

Executive Summary This report summarizes the results of the first comprehensive biological inventory of Gila Cliff Dwellings National Monument (NM) in western New Mexico. This project was part of a larger effort to inventory plants and vertebrates in eight National Park Service units in Arizona and New Mexico. Our surveys address many of the objectives that were set forth in the monument's natural resource management plan almost 20 years ago, but until this effort, those goals were never accomplished. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Gila Cliff Dwellings NM to document presence of species within the boundaries of the monument. For all taxonomic groups that we studied, we collected 'incidental' sightings on U.S. Forest Service lands adjacent to the monument, and in a few cases we did formal surveys on those lands. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a biological monitoring program for Gila Cliff Dwellings NM and surrounding lands. We recorded 552 species at Gila Cliff Dwellings NM and the surrounding lands (Table 1). We found no non-native species of reptiles, birds, or mammals, one non-native amphibian (American bullfrog), and 33 non-native plants. Particularly on lands adjacent to the monument we found that the American bullfrog was very abundant, which is a cause for significant management concern. Species of non-native plants that are of management concern include red brome, bufflegrass, and cheatgrass. For a park unit of its size and geographic location, we found the plant and vertebrate communities to be fairly diverse; for each taxonomic group we found representative species from a wide range of taxonomic orders and/or families. The monument's geographic location, with influences from the Rocky Mountain, Chihuahuan Desert, and Madrean ecological provinces, plays an important role in determining the species richness at the monument. Also important is the wide range of conditions at the site. The diversity of plants results from a wide variety of soil types and aspects (from the cool, moist Cliff Dweller Canyon to dry mesa slopes) and an abundance of water from the West Fork of the Gila River. In turn, the vertebrate communities respond to this diversity of vegetation, topography, and microsites. For example, for each taxonomic group we found species that were only associated with a single community type, most often the riparian areas along the West and Middle forks of the Gila River. We found cause for significant concern with regard to loss of species in the last few decades. One species of amphibian (Chiricahua leopard frog) is certainly extirpated from the area. Three other species of amphibians (Mexican spadefoot, Woodhouse's toad, and red-spotted toad), reported as being 'common' in the area in 1971, were not found during our surveys. In addition, we did not find three species of rodents that were found in 1965: silky pocket mouse, Ord's kangaroo rat, and southern grasshopper mouse. The monument's aquatic vertebrate component, in particular, may be at a critical juncture whereby other species, such as gartersnakes, may be poised for extirpation. Declining abundance of native fish species has been demonstrated from long-term monitoring of these communities along the Middle Fork of the Gila River. This report includes lists of species recorded by us or species likely to be recorded with additional survey effort. It also includes management implications from our work - how the monument staff might better maintain or enhance the unique biological resources of the monument. This study is the first step in a long-term process of compiling information on the biological resources of the monument and its surrounding areas. We recommend additional inventory and monitoring studies and identify components of our effort that could be improved upon

79. Photocopy of photograph (original print in the Minnesota Historical ...

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

79. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, ca. 1890, #741.) ALEXANDER RAMSEY HOUSE, ca. 1890 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

76. Photocopy of photograph (original print in the Minnesota Historical ...

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

76. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1860. #22358.) UPPER LEVEE FROM CHESTNUT STREET, 1860 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

74. Photocopy of photograph (original print in the Minnesota Historical ...

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

74. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1896. #35105.) FIRST ROBERT STREET BRIDGE, ca. 1896 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

76 FR 2754 - Citizens Coinage Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

.... Time: 9 a.m. to 12 p.m. Location: 8th Floor Board Room, United States Mint, 801 9th Street, NW... CONTACT: Cliff Northup, United States Mint Liaison to the CCAC; 801 9th Street, NW.; Washington, DC 20220...

75 FR 70363 - Citizens Coinage Advisory Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

.... Time: 8 a.m. to 12 p.m. Location: 8th Floor Board Room, United States Mint, 801 9th Street, NW... CONTACT: Cliff Northup, United States Mint Liaison to the CCAC; 801 9th Street, NW., Washington, DC 20220...

Opportunity at the Wall 3-D

NASA Image and Video Library

2004-11-23

NASA Mars Exploration Rover Opportunity reached the base of Burns Cliff, a portion of the inner wall of Endurance Crater in this anaglyph from the rover 285th martian day Nov. 11, 2004. 3D glasses are necessary to view this image.

MICROBIAL ECOLOGY OF POLLUTION ABATEMENT

EPA Science Inventory

My career started with Cliff Dahm at the University of New Mexico. The western United States had been experiencing a new “gold rush” using cyanide to mine previously unextractable, low-grade ore and we studied the potential to stimulate native cyanide-degrading micro...

A new rapid method for rockfall energies and distances estimation

NASA Astrophysics Data System (ADS)

Giacomini, Anna; Ferrari, Federica; Thoeni, Klaus; Lambert, Cedric

2016-04-01

Rockfalls are characterized by long travel distances and significant energies. Over the last decades, three main methods have been proposed in the literature to assess the rockfall runout: empirical, process-based and GIS-based methods (Dorren, 2003). Process-based methods take into account the physics of rockfall by simulating the motion of a falling rock along a slope and they are generally based on a probabilistic rockfall modelling approach that allows for taking into account the uncertainties associated with the rockfall phenomenon. Their application has the advantage of evaluating the energies, bounce heights and distances along the path of a falling block, hence providing valuable information for the design of mitigation measures (Agliardi et al., 2009), however, the implementation of rockfall simulations can be time-consuming and data-demanding. This work focuses on the development of a new methodology for estimating the expected kinetic energies and distances of the first impact at the base of a rock cliff, subject to the conditions that the geometry of the cliff and the properties of the representative block are known. The method is based on an extensive two-dimensional sensitivity analysis, conducted by means of kinematic simulations based on probabilistic modelling of two-dimensional rockfall trajectories (Ferrari et al., 2016). To take into account for the uncertainty associated with the estimation of the input parameters, the study was based on 78400 rockfall scenarios performed by systematically varying the input parameters that are likely to affect the block trajectory, its energy and distance at the base of the rock wall. The variation of the geometry of the rock cliff (in terms of height and slope angle), the roughness of the rock surface and the properties of the outcropping material were considered. A simplified and idealized rock wall geometry was adopted. The analysis of the results allowed finding empirical laws that relate impact energies and distances at the base to block and slope features. The validation of the proposed approach was conducted by comparing predictions to experimental data collected in the field and gathered from the scientific literature. The method can be used for both natural and constructed slopes and easily extended to more complicated and articulated slope geometries. The study shows its great potential for a quick qualitative hazard assessment providing indication about impact energy and horizontal distance of the first impact at the base of a rock cliff. Nevertheless, its application cannot substitute a more detailed quantitative analysis required for site-specific design of mitigation measures. Acknowledgements The authors gratefully acknowledge the financial support of the Australian Coal Association Research Program (ACARP). References Dorren, L.K.A. (2003) A review of rockfall mechanics and modelling approaches, Progress in Physical Geography 27(1), 69-87. Agliardi, F., Crosta, G.B., Frattini, P. (2009) Integrating rockfall risk assessment and countermeasure design by 3D modelling techniques. Natural Hazards and Earth System Sciences 9(4), 1059-1073. Ferrari, F., Thoeni, K., Giacomini, A., Lambert, C. (2016) A rapid approach to estimate the rockfall energies and distances at the base of rock cliffs. Georisk, DOI: 10.1080/17499518.2016.1139729.

77 FR 51556 - Sheldon National Wildlife Refuge, Humboldt County and Washoe County, NV; Lake County, OR; Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... found on the Refuge are primarily shrub-steppe uplands, and springs and spring brooks, basalt cliffs and..., representative of historical conditions in the Great Basin. Emphasis would be placed on improving shrub-steppe...

76 FR 67232 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on U.S...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

..., 2011--8:30 a.m. Until 5 p.m. The Subcommittee will review Chapters 7, ``Instrumentation and Controls... Chapter 7, ``Instrumentation and Controls,'' of the Calvert Cliffs RCOL SER with Open Items. The...

77. Photocopy of photograph (original print in the Minnesota Historical ...

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

77. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1859. #377. Photographer: Illingworth.) LOWER LEVEE FROM JACKSON STREET, 1859 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

65. Photocopy of photograph (original print in the Minnesota Historical ...

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

65. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1889. #37682.) VIEW TO NORTH, SHOWING SPAN NOS. 6-24, 1889 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

69. Photocopy of photograph (original print in the Minnesota Historical ...

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

69. Photocopy of photograph (original print in the Minnesota Historical society, St. Paul, Minnesota, 1984. #32375.) VIEW TO WEST, SHOWING DAMAGED BRIDGE AFTER CYCLONE. 1904. - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

78 FR 64009 - Certain Optical Disc Drives, Components Thereof, and Products Containing the Same; Institution of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-25

... Cliffs, NJ 07632. Nintendo Co., Ltd., 11-1 Hokotate-cho, Kamitoba, Minami-ku, Kyoto 601- 8501, Japan. Nintendo of America, Inc., 4600 150th Avenue NE, Redmond, WA 98052- 5113. Panasonic Corp., 1006, Oaza...

Intelligent Help in the LOCATE Workspace Layout Tool

DTIC Science & Technology

1999-06-01

LOCATE’s basic design and analysis features; • commercialising the application; • expanding the groundwork for tracking actions and goals at the interface...Muraida, D.J. (Eds.) (1993). Automating instructional design: Concepts and issues. Englewood Cliffs, N.J.: Educational Technology Publications

Hazardous Waste Cleanup: Hess Corporation in Port Reading, New Jersey

EPA Pesticide Factsheets

The Hess Corporation Port Reading Refinery occupies approximately 210 acres on Cliff Road in an industrial waterfront area of Port Reading, New Jersey. The Conrail Port Reading Rail Yard is located to the north, the Arthur Kill shipping channel to the

Averting the Fiscal Cliff Act

THOMAS, 112th Congress

Rep. Jordan, Jim [R-OH-4

2012-12-19

House - 12/19/2012 Referred to the Subcommittee on Health. (All Actions) Notes: For further action, see H.R.8, which became Public Law 112-240 on 1/2/2013. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

75 FR 11228 - Citizens Coinage Advisory Committee March 2010 Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

..., 2010. Time: 3 p.m. to 5 p.m. Location: 8th Floor Boardroom, United States Mint, 801 9th Street, NW... CONTACT: Cliff Northup, United States Mint Liaison to the CCAC; 801 9th Street, NW.; Washington, DC 20220...

36 CFR 261.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... beneath the surface of the earth or within a cliff or ledge and which is large enough to permit a person... and communication bridges between various socioeconomic groups; and further the administration... General Prohibitions § 261.2 Definitions. The following definitions apply to this part: Administrative...

36 CFR 261.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... beneath the surface of the earth or within a cliff or ledge and which is large enough to permit a person... and communication bridges between various socioeconomic groups; and further the administration... General Prohibitions § 261.2 Definitions. The following definitions apply to this part: Administrative...

High-Resolution Monitoring of Himalayan Glacier Dynamics Using Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Immerzeel, W.; Kraaijenbrink, P. D. A.; Shea, J.; Shrestha, A. B.; Pellicciotti, F.; Bierkens, M. F.; de Jong, S. M.

2014-12-01

Himalayan glacier tongues are commonly debris covered and play an important role in modulating the glacier response to climate . However, they remain relatively unstudied because of the inaccessibility of the terrain and the difficulties in field work caused by the thick debris mantles. Observations of debris-covered glaciers are therefore limited to point locations and airborne remote sensing may bridge the gap between scarce, point field observations and coarse resolution space-borne remote sensing. In this study we deploy an Unmanned Airborne Vehicle (UAV) on two debris covered glaciers in the Nepalese Himalayas: the Lirung and Langtang glacier during four field campaigns in 2013 and 2014. Based on stereo-imaging and the structure for motion algorithm we derive highly detailed ortho-mosaics and digital elevation models (DEMs), which we geometrically correct using differential GPS observations collected in the field. Based on DEM differencing and manual feature tracking we derive the mass loss and the surface velocity of the glacier at a high spatial resolution and accuracy. We also assess spatiotemporal changes in supra-glacial lakes and ice cliffs based on the imagery. On average, mass loss is limited and the surface velocity is very small. However, the spatial variability of melt rates is very high, and ice cliffs and supra-glacial ponds show mass losses that can be an order of magnitude higher than the average. We suggest that future research should focus on the interaction between supra-glacial ponds, ice cliffs and englacial hydrology to further understand the dynamics of debris-covered glaciers. Finally, we conclude that UAV deployment has large potential in glaciology and it represents a substantial advancement over methods currently applied in studying glacier surface features.

Characterization of the 3-D fracture setting of an unstable rock mass: From surface and seismic investigations to numerical modeling

NASA Astrophysics Data System (ADS)

Colombero, C.; Baillet, L.; Comina, C.; Jongmans, D.; Vinciguerra, S.

2017-08-01

The characterization of the fracturing state of a potentially unstable rock cliff is a crucial requirement for stability assessments and mitigation purposes. Classical measurements of fracture location and orientation can however be limited by inaccessible rock exposures. The steep topography and high-rise morphology of these cliffs, together with the widespread presence of fractures, can additionally condition the success of geophysical prospecting on these sites. In order to mitigate these limitations, an innovative approach combining noncontact geomechanical measurements, active and passive seismic surveys, and 3-D numerical modeling is proposed in this work to characterize the 3-D fracture setting of an unstable rock mass, located in NW Italian Alps (Madonna del Sasso, VB). The 3-D fracture geometry was achieved through a combination of field observations and noncontact geomechanical measurements on oriented pictures of the cliff, resulting from a previous laser-scanning and photogrammetric survey. The estimation of fracture persistence within the rock mass was obtained from surface active seismic surveys. Ambient seismic noise and earthquakes recordings were used to assess the fracture control on the site response. Processing of both data sets highlighted the resonance properties of the unstable rock volume decoupling from the stable massif. A finite element 3-D model of the site, including all the retrieved fracture information, enabled both validation and interpretation of the field measurements. The integration of these different methodologies, applied for the first time to a complex 3-D prone-to-fall mass, provided consistent information on the internal fracturing conditions, supplying key parameters for future monitoring purposes and mitigation strategies.

Frequency of effective wave activity and the recession of coastal bluffs: Calvert Cliffs, Maryland

USGS Publications Warehouse

Wilcock, P.R.; Miller, D.S.; Shea, R.H.; Kerkin, R.T.

1998-01-01

The Calvert Cliffs, Chesapeake Bay, Maryland, USA, erode by direct wave undercutting or by freeze/thaw erosion accompanied by wave removal of slope debris. Directly undercut slopes recede more rapidly, with long-term rates exceeding 1.0 m/yr; freeze/thaw slopes recede at rates approaching 0.5 m/yr. The frequency of wave height and water level at the shoreline is estimated for eleven sites based on a 37-year wind record, estimates of storm surge, offshore wave geometry, nearshore wave transformation, and breaking wave type. Locations experiencing the largest slope recession are not uniformly those with the largest cumulative wave energy; the resistance to erosion of the slope toe must also be accounted for. An index of relative wave strength is defined as the ratio of wave pressure T and the cohesive strength S of the slope material. For the Calvert Cliffs, a minimum relative wave strength for initiating erosion of intact material is 0.05 < T/S < 0.1. A cumulative duration of ???50 hours per year for T/S ??? 0.1 distinguishes undercut and nonundercut slopes and recession rates greater or lesser than 0.5 m/yr. The relative wave strength index may be used to identify sites at risk of increased erosion. At one site with a small historical erosion rate, the loss of a protective beach and associated decrease in toe elevation caused a positive shift in the frequency of large T/S. Direct wave undercutting and increased slope recession may be anticipated at this site, as indicated by the development of an undercut notch during the course of the study.

The Purisima Formation at Capitola Beach, Santa Cruz County, CA: A Deeper Examination of Pliocene Fossils

NASA Astrophysics Data System (ADS)

White, L. D.; Brooks, K.; Chen, R.; Chen, T.; James, T.; Gonzales, J.; Schumaker, D.; Williams, D.

2005-12-01

Fossil samples from the Pliocene Purisima Formation at Capitola Beach in Santa Cruz County, CA were collected in July-August 2005. The Purisima Formation composes the bulk of the cliffs exposed at Capitola Beach and a rich assemblage of well-preserved fossils occur in gray to brown sandstone and siltstone. Erosion of the cliff face averages 0.3 meter/year and fresh cliff falls in the winter and spring months of 2005 provided an excellent opportunity to resample the Capitola Beach section of the Purisima Formation previously documented by Perry (1988). Organisms were identified from information in Perry (1988) and were compared with collections at the California Academy of Sciences. The most abundant fossils found are from the phylum Mollusca, classes Bivalvia and Gastropoda. Abundant bivalve taxa are: Anadara trilineata, Clinocardium meekianum, Macoma sp., Protothaca staleyi, and Tresus pajaroanus. Also common are the gastropods, Calyptraea fastigata, Crepdiula princeps, Mitrella gausapata, Nassarius grammatus, Nassarius californianus, Natica clausa, and Olivella pedroana. Less common invertebrate fossils are from the phylum Echinodermata ( Dendraster sp., the extinct fossil sand dollar) and from the phylum Arthropoda ( Crustacea), crab fragments ( Cancer) and barnacles ( Balanus). Because numerous fossils are concentrated as fragments in shell beds, Norris (1986) and Perry (1988) believe many were redeposited as storm beds during strong current events that promoted rapid burial. In contrast, whale and other vertebrate bones are common in certain horizons and their presence may be related to the conditions that promoted phosphate mineralization, such as episodes of low sedimentation rates and prolonged exposure on the seafloor (Föllmi and Garrison, 1991). The bone beds, together with the rich infaunal and epifaunal invertebrate assemblages, represent a community of invertebrate organisms that thrived in a shallow marine sea during the Pliocene epoch, approximately 3-5 million years ago.

Familiarity with breeding habitat improves daily survival in colonial cliff swallows

PubMed Central

BROWN, CHARLES R.; BROWN, MARY BOMBERGER; BRAZEAL, KATHLEEN R.

2008-01-01

One probable cost of dispersing to a new breeding habitat is unfamiliarity with local conditions such as the whereabouts of food or the habits of local predators, and consequently immigrants may have lower probabilities of survival than more experienced residents. Within a breeding season, estimated daily survival probabilities of cliff swallows (Petrochelidon pyrrhonota) at colonies in southwestern Nebraska were highest for birds that had always nested at the same site, followed by those for birds that had nested there in some (but not all) past years. Daily survival probabilities were lowest for birds that were naïve immigrants to a colony site and for yearling birds that were nesting for the first time. Birds with past experience at a colony site had monthly survival 8.6% greater than that of naïve immigrants. All colonies where experienced residents did better than immigrants were smaller than 750 nests in size, and in colonies greater than 750 nests, naïve immigrants paid no survival costs relative to experienced residents. Removal of nest ectoparasites by fumigation resulted in higher survival probabilities for all birds, on average, and diminished the differences between immigrants and past residents, probably by improving bird condition to the extent that effects of past experience were relatively less important and harder to detect. The greater survival of experienced residents could not be explained by condition or territory quality, suggesting that familiarity with a local area confers survival advantages during the breeding season for cliff swallows. Colonial nesting may help to moderate the cost of unfamiliarity with an area, likely through social transfer of information about food sources and enhanced vigilance in large groups. PMID:19802326

Intertidal sand body migration along a megatidal coast, Kachemak Bay, Alaska

USGS Publications Warehouse

Adams, P.N.; Ruggiero, P.; Schoch, G.C.; Gelfenbaum, G.

2007-01-01

Using a digital video-based Argus Beach Monitoring System (ABMS) on the north shore of Kachemak Bay in south central Alaska, we document the timing and magnitude of alongshore migration of intertidal sand bed forms over a cobble substrate during a 22-month observation period. Two separate sediment packages (sand bodies) of 1-2 m amplitude and ???200 m wavelength, consisting of well-sorted sand, were observed to travel along shore at annually averaged rates of 278 m/yr (0.76 m/d) and 250 m/ yr (0.68 m/d), respectively. Strong seasonality in migration rates was shown by the contrast of rapid winter and slow summer transport. Though set in a megatidal environment, data indicate that sand body migration is driven by eastward propagating wind waves as opposed to net westward directed tidal currents. Greatest weekly averaged rates of movement, exceeding 6 m/d, coincided with wave heights exceeding 2 m suggesting a correlation of wave height and sand body migration. Because Kachemak Bay is partially enclosed, waves responsible for sediment entrainment and transport are locally generated by winds that blow across lower Cook Inlet from the southwest, the direction of greatest fetch. Our estimates of sand body migration translate to a littoral transport rate between 4,400-6,300 m3/yr. Assuming an enclosed littoral cell, minimal riverine sediment contributions, and a sea cliff sedimentary fraction of 0.05, we estimate long-term local sea cliff retreat rates of 9-14 cm/yr. Applying a numerical model of wave energy dissipation to the temporally variable beach morphology suggests that sand bodies are responsible for enhancing wave energy dissipation by ???13% offering protection from sea cliff retreat. Copyright 2007 by the American Geophysical Union.

Toppling analysis of the Echo Cliffs precariously balanced rock

USGS Publications Warehouse

Veeraraghavan, Swetha; Hudnut, Kenneth W.; Krishnan, Swaminathan

2017-01-01

Toppling analysis of a precariously balanced rock (PBR) can provide insight into the nature of ground motion that has not occurred at that location in the past and, by extension, can constrain peak ground motions for use in engineering design. Earlier approaches have targeted 2D models of the rock or modeled the rock–pedestal contact using spring‐damper assemblies that require recalibration for each rock. Here, a method to model PBRs in 3D is presented through a case study of the Echo Cliffs PBR. The 3D model is created from a point cloud of the rock, the pedestal, and their interface, obtained using terrestrial laser scanning. The dynamic response of the model under earthquake excitation is simulated using a rigid‐body dynamics algorithm. The veracity of this approach is demonstrated through comparisons against data from shake‐table experiments. Fragility maps for toppling probability of the Echo Cliffs PBR as a function of various ground‐motion parameters, rock–pedestal interface friction coefficient, and excitation direction are presented. These fragility maps indicate that the toppling probability of this rock is low (less than 0.2) for peak ground acceleration (PGA) and peak ground velocity (PGV) lower than 3  m/s2 and 0.75  m/s, respectively, suggesting that the ground‐motion intensities at this location from earthquakes on nearby faults have most probably not exceeded the above‐mentioned PGA and PGV during the age of the PBR. Additionally, the fragility maps generated from this methodology can also be directly coupled with existing probabilistic frameworks to obtain direct constraints on unexceeded ground motion at a PBR’s location.

Site selection and nest survival of the Bar-Headed Goose (Anser indicus) on the Mongolian Plateau

USGS Publications Warehouse

Batbayar, Nyambayar; Takekawa, John Y.; Natsagdorj, Tseveenmyadag; Spragens, Kyle A.; Xiao, Xiamgming

2014-01-01

Waterbirds breeding on the Mongolian Plateau in Central Asia must find suitable wetland areas for nesting in a semiarid region characterized by highly variable water conditions. The first systematic nesting study of a waterbird dependent on this region for breeding was conducted on the Bar-headed Goose (Anser indicus). The purpose of this study was to document Bar-headed Goose nesting locations, characterize nests and nesting strategies, and estimate daily nest survival (n = 235 nests) from eight areas of west-central Mongolia across three summers (2009–2011) using a modified Mayfield estimator. Bar-headed Goose daily nest survival ranged from 0.94 to 0.98, with a 3-year average nest success of 42.6% during incubation. Bar-headed Geese were found to primarily nest on isolated pond and lake islands as previously reported, but were also documented regularly, though less frequently, along rocky cliffs in several regions of west-central Mongolia. Daily nest survival was higher for cliff nests than for island nests. Information-theoretic models indicated that nest survival decreased with nest age and varied annually with changing environmental conditions. Results of this study suggest that while Bar-headed Geese primarily rely on nesting island sites these sites may be more susceptible to anthropogenic disturbance and predation events influenced by seasonal variation in environmental conditions, and that higher daily nest survival values documented for the less frequent cliff nest strategy may provide an important alternative strategy during poor island nest success years. Thus, conservation efforts for this and other waterbird species in the semiarid region should be focused on conserving nesting islands and protecting them from disturbance in areas of high livestock densities experiencing a rapidly warming climate.

Variation in age composition among colony sizes in Cliff Swallows.

PubMed

Brown, Charles R; Roche, Erin A; Brown, Mary Bomberger

2014-09-01

Variation in group size is characteristic of most social species. The extent to which individuals sort among group sizes based on age may yield insight into why groups vary in size and the age-specific costs and benefits of different social environments. We investigated the age composition of Cliff Swallow ( Petrochelidon pyrrhonota ) colonies of different sizes over 18 years at a long-term study site in western Nebraska, USA. Using years elapsed since banding as a relative measure of age for over 194,000 birds, we found that the proportion of age-class-1 swallows (birds banded as nestlings or juveniles or adults in the year of banding) of both sexes increased in larger colonies and at colony sites becoming active later in the summer. Age composition was unrelated to how often a particular colony site was used. The effect of colony size most likely reflected the fact that older birds return to the same colony site in successive years even when the colony size there decreases, and that yearlings and immigrants benefit more from larger colonies than do older, more experienced individuals. The date effect probably resulted in part from later spring arrival by younger and/or immigrant swallows. At fumigated sites where ectoparasitic swallow bugs ( Oeciacus vicarius ) had been removed, age composition did not vary with either colony size or colony initiation date. The patterns reported here appear to be driven partially by the presence of ectoparasites and suggest that the hematophagous bugs influence variation in Cliff Swallow group composition. Our results are consistent with the hypothesis that variation in colony size reflects, in part, age-based sorting of individuals among groups.

Landslide Tsunami Hazard in Madeira Island, NE Atlantic - Numerical Simulation of the 4 March 1930 Tsunami

NASA Astrophysics Data System (ADS)

Omira, R.; Baptista, M. A.; Quartau, R.; Ramalho, M. I.

2017-12-01

Madeira, the main Island of the Madeira Archipelago with an area of 728 km2, is a North East Atlantic volcanic Island highly susceptible to cliff instability. Historical records contain accounts of a number of mass-wasting events along the Island, namely in 1969, 1804, 1929 and 1930. Collapses of cliffs are major hazards in oceanic Islands as they involve relatively large volumes of material, generating fast running debris avalanches, and even cause destructive tsunamis when entering the sea. On March 4th, 1930, a sector of the Cape Girão cliff, located in the southern shore of Madeira Island, collapsed into the sea and generated an 8 m tsunami wave height. The landslide-induced tsunami propagated along Madeirás south coast and flooded the Vigário beach, 200-300 m of inundation extent, causing 20 casualties. In this study, we investigate the 1930 subaerial landslide-induced tsunami and its impact on the nearest coasts using numerical modelling. We first reconstruct the pre-event morphology of the area, and then simulate the initial movement of the sliding mass, the propagation of the tsunami wave and the inundation of the coast. We use a multi-layer numerical model, in which the lower layer represents the deformable slide, assumed to be a visco-plastic fluid, and bounded above by air, in the subaerial motion phase, and by seawater governed by shallow water equations. The results of the simulation are compared with the historical descriptions of the event to calibrate the numerical model and evaluate the coastal impact of a similar event in present-day coastline configuration of the Island. This work is supported by FCT- project UID/GEO/50019/2013 - Instituto Dom Luiz and by TROYO project.

High-resolution three-dimensional imaging and analysis of rock falls in Yosemite valley, California

USGS Publications Warehouse

Stock, Gregory M.; Bawden, G.W.; Green, J.K.; Hanson, E.; Downing, G.; Collins, B.D.; Bond, S.; Leslar, M.

2011-01-01

We present quantitative analyses of recent large rock falls in Yosemite Valley, California, using integrated high-resolution imaging techniques. Rock falls commonly occur from the glacially sculpted granitic walls of Yosemite Valley, modifying this iconic landscape but also posing signifi cant potential hazards and risks. Two large rock falls occurred from the cliff beneath Glacier Point in eastern Yosemite Valley on 7 and 8 October 2008, causing minor injuries and damaging structures in a developed area. We used a combination of gigapixel photography, airborne laser scanning (ALS) data, and ground-based terrestrial laser scanning (TLS) data to characterize the rock-fall detachment surface and adjacent cliff area, quantify the rock-fall volume, evaluate the geologic structure that contributed to failure, and assess the likely failure mode. We merged the ALS and TLS data to resolve the complex, vertical to overhanging topography of the Glacier Point area in three dimensions, and integrated these data with gigapixel photographs to fully image the cliff face in high resolution. Three-dimensional analysis of repeat TLS data reveals that the cumulative failure consisted of a near-planar rock slab with a maximum length of 69.0 m, a mean thickness of 2.1 m, a detachment surface area of 2750 m2, and a volume of 5663 ?? 36 m3. Failure occurred along a surfaceparallel, vertically oriented sheeting joint in a clear example of granitic exfoliation. Stress concentration at crack tips likely propagated fractures through the partially attached slab, leading to failure. Our results demonstrate the utility of high-resolution imaging techniques for quantifying far-range (>1 km) rock falls occurring from the largely inaccessible, vertical rock faces of Yosemite Valley, and for providing highly accurate and precise data needed for rock-fall hazard assessment. ?? 2011 Geological Society of America.

Pediatric-Inspired Treatment Regimens for Adolescents and Young Adults With Philadelphia Chromosome-Negative Acute Lymphoblastic Leukemia: A Review.

PubMed

Siegel, Stuart E; Stock, Wendy; Johnson, Rebecca H; Advani, Anjali; Muffly, Lori; Douer, Dan; Reed, Damon; Lewis, Mark; Freyer, David R; Shah, Bijal; Luger, Selina; Hayes-Lattin, Brandon; Jaboin, Jerry J; Coccia, Peter F; DeAngelo, Daniel J; Seibel, Nita; Bleyer, Archie

2018-05-01

The incidence of acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL) in adolescent and young adult (AYA) patients (age range, 15-39 years) in the United States is increasing at a greater rate than in younger or older persons. Their optimal treatment has been increasingly debated as pediatric regimens have become more widely used in the age group. This review compares the basic features of pediatric and adult chemotherapy regimens for ALL and LBL, recognizes and describes the challenges of the pediatric regimen, and suggests strategies to facilitate its adoption for AYAs with ALL and LBL. All but 2 of 25 published comparisons of outcomes with pediatric and adult regimens for ALL and LBL in AYAs and 1 meta-analysis favor the pediatric regimen. After more than a half-century of clinical trials of the pediatric regimens, including at least 160 phase 3 trials in the United States, the pediatric regimens have become far more complex than most adult regimens. Asparaginase, a critical component of the pediatric regimens, is more difficult to administer to AYAs (and older patients) but nonetheless has a favorable benefit to toxicity ratio for AYAs. A dramatic reduction in outcome of ALL and LBL during the AYA years (the "survival cliff") is coincident with similar reductions in proportions of AYAs referred to academic centers and enrolled on clinical trials (the "accrual cliff" and "referral cliff"). The accumulating data increasingly support treating AYAs with ALL and LBL with a pediatric-inspired regimen or an approved institutional or national clinical trial tailored for this patient group. A need to develop clinical trials specifically for AYAs and to encourage their participation is paramount, with a goal to improve both the quantity and quality of survival.

73. Photocopy of photograph (original print in the Minnesota Historical ...

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

73. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1867. #MR2.9 SP4.2/rll.) FIRST WABASHA STREET BRIDGE, 1867 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

66. Photocopy of photograph (original print in the Minnesota Historical ...

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

66. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, ca. 1925. #19657.) VIEW TO NORTHWEST, SHOWING SPAN NOS. 21 TO 26 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

75 FR 2531 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

... Power, LLC, Terra-Gen VG Wind, LLC, Terra-Gen 251 Wind, LLC, Chandler Wind Partners, LLC. Description... Power Source Generation, Inc., Calvert Cliffs Nuclear Power Plant LLC, Constellation Energy Commodities..., Inc., Constellation Energy Commodities Group Maine, LLC, R.E. Ginna Nuclear Power Plant, Raven One...

78 FR 54675 - Notice of Intent To Collect Fees on Public Lands in the Red Cliffs National Conservation Area...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... era movie set for Columbia Pictures' film, ``They Came to Cordura.'' Amenities in the White Reef Park... Pass (Golden Access Passport) will be entitled to a 50 percent discount on standard amenity recreation...

Pressurized thermal shock evaluation of the Calvert Cliffs Unit 1 Nuclear Power Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbott, L

1985-09-01

An evaluation of the risk to the Calvert Cliffs Unit 1 nuclear power plant due to pressurized thermal shock (PTS) has been completed by Oak Ridge National Laboratory (ORNL) with the assistance of several other organizations. This evaluation was part of a Nuclear Regulatory Commission program designed to study the PTS risk to three nuclear plants, the other two plants being Oconee Unit 1 and H.B. Robinson Unit 2. The specific objectives of the program were to (1) provide a best estimate of the frequency of a through-the-wall crack in the pressure vessel at each of the three plants, togethermore » with the uncertainty in the estimated frequency and its sensitivity to the variables used in the evaluation; (2) determine the dominant overcooling sequences contributing to the estimated frequency and the associated failures in the plant systems or in operator actions; and (3) evaluate the effectiveness of potential corrective measures.« less

Pluripotency of embryo-derived stem cells from rodents, lagomorphs, and primates: Slippery slope, terrace and cliff.

PubMed

Savatier, Pierre; Osteil, Pierre; Tam, Patrick P L

2017-03-01

The diverse cell states and in vitro conditions for the derivation and maintenance of the mammalian embryo-derived pluripotent stem cells raise the questions of whether there are multiple states of pluripotency of the stem cells of each species, and if there are innate species-specific variations in the pluripotency state. We will address these questions by taking a snapshot of our knowledge of the properties of the pluripotent stem cells, focusing on the maintenance of pluripotency and inter-conversion of the different types of pluripotent stem cells from rodents, lagomorphs and primates. We conceptualize pluripotent stem cells acquiring a series of cellular states represented as terraces on a slope of descending gradient of pluripotency. We propose that reprogramming pluripotent stem cells from a primed to a naive state is akin to moving upstream over a steep cliff to a higher terrace. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Radon mitigation at Birch Cliff Public School.

PubMed

Moridi, R; Becker, E

1996-01-01

In 1991, Canadian Institute for Radiation Safety (CAIRS) conducted a radon screening program in all Metropolitan Toronto public schools. Birch Cliff Public School had a radon progeny level higher than the action level of 4.16 x 10(-7) Jm-3 (20 mWL). Follow-up radon testing was carried out at the school. Locations on the ground floor and in the basement were tested. All locations on the ground floor had radon progeny levels below the action level. Six locations in the basement had readings above the action level. All cracks and openings in the basement were sealed and a new heating/ventilating (HV) system for the basement was designed and installed. Then, the basement was tested again. Radon progeny levels are now well below the action level with an average of 7.43 x 10(-8) Jm-3 (3.57 mWL). This is about one fifth of the average radon progeny level found in the first stage of follow-up testing.

Analysis of Samples Collected from the Surface of Interim Storage Canisters at Calvert Cliffs in June 2017: Revision 01.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Charles R.; Schindelholz, Eric John

In June 2017, dust and salt samples were collected from the surface of Spent Nuclear Fuel (SNF) dry storage canisters at the Calvert Cliffs Nuclear Power Plant. The samples were delivered to Sandia National laboratories for analysis. Two types of samples were collected: filter-backed Scotch-Brite TM pads were used to collect dry dust samples for characterization of salt and dust morphologies and distributions; and Saltsmart TM test strips were used to collect soluble salts for determining salt surface loadings per unit area. After collection, the samples were sealed into plastic sleeves for shipping. Condensation within the sleeves containing the Scotch-Britemore » TM samples remobilized the salts, rendering them ineffective for the intended purpose, and also led to mold growth, further compromising the samples; for these reasons, the samples were not analyzed. The SaltSmart TM samples were unaffected and were analyzed by ion chromatography for major anions and cations. The results of those analyses are presented here.« less

Wind Carved Rock

NASA Image and Video Library

2016-10-19

The distinctively fluted surface and elongated hills in this image in Medusae Fossae are caused by wind erosion of a soft fine-grained rock. Called yardangs, these features are aligned with the prevailing wind direction. This wind direction would have dominated for a very long time to carve these large-scale features into the exposed rock we see today. Yardangs not only reveal the strength and direction of historic winds, but also reveal something of the host rock itself. Close inspection by HiRISE shows an absence of boulders or rubble, especially along steep yardang cliffs and buttresses. The absence of rubble and the scale of the yardangs tells us that the host rock consists only of weakly cemented fine granules in tens of meters or more thick deposits. Such deposits could have come from extended settling of volcanic ash, atmospheric dust, or accumulations of wind deposited fine sands. After a time these deposits became cemented and cohesive, illustrated by the high standing relief and exposed cliffs. http://photojournal.jpl.nasa.gov/catalog/PIA21111

Time - A Traveler's Guide

NASA Astrophysics Data System (ADS)

Pickover, Clifford A.

1999-09-01

"Bucky Fuller thought big," Wired magazine recently noted, "Arthur C. Clarke thinks big, but Cliff Pickover outdoes them both." In his newest book, Cliff Pickover outdoes even himself, probing a mystery that has baffled mystics, philosophers, and scientists throughout history--What is the nature of time?In Time: A Traveler's Guide , Pickover takes readers to the forefront of science as he illuminates the most mysterious phenomenon in the universe--time itself. Is time travel possible? Is time real? Does it flow in one direction only? Does it have a beginning and an end? What is eternity? Pickover's book offers a stimulating blend of Chopin, philosophy, Einstein, and modern physics, spiced with diverting side-trips to such topics as the history of clocks, the nature of free will, and the reason gold glitters. Numerous diagrams ensure readers will have no trouble following along.By the time we finish this book, we understand a wide variety of scientific concepts pertaining to time. And most important, we will understand that time travel is, indeed, possible.

Rate estimates for lateral bedrock erosion based on radiocarbon ages, Duck River, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brakenridge, G.R.

Rates of bedrock erosion in ingrown meandering rivers can be inferred from the location of buried relict flood-plain and river-bank surfaces, associated paleosols, and radiocarbon dates. Two independent methods are used to evaluate the long-term rates of limestone bedrock erosion by the Duck River. Radiocarbon dates on samples retrieved from buried Holocene flood-plain and bank surfaces indicate lateral migration of the river bank at average rates of 0.6-1.9 m/100 yr. Such rates agree with lateral bedrock cliff erosion rates of 0.5-1.4 m/100 yr, as determined from a comparison of late Pleistocene and modern bedrock cliff and terrace scarp positions. Thesemore » results show that lateral bedrock erosion by this river could have occurred coevally with flood-plain and terrace formation and that the resulting evolution of valley meander bends carved into bedrock is similar in many respects to that of channel meanders cut into alluvium. 11 references, 5 figures.« less

A General Surface Representation Module Designed for Geodesy

DTIC Science & Technology

1980-06-01

one considers as a reasonable interpolation function, one of the often accepted compromises is the choice q = 2 (Schumnaker, 1976, Bybee and Bedross...Fast Fourier Transform: Englewood Cliffs, New Jersey. Bybee , J.E. and G.M. Bedross (1978): The IPIN computer network control softward. In: Proceedings

36 CFR 290.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the duties described in this part. Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is... hydrologic resources. National Forest System lands means all national forest lands reserved or withdrawn from...

Pueblo: Search for the Ancient Ones.

ERIC Educational Resources Information Center

Creamer, Winifred; Haas, Jonathan

1991-01-01

Uses archaeological evidence to trace the history of the Pueblo ancestors in the Southwest's Four Corners region as they evolved from nomadic hunters and gatherers into farmers, and later, were forced by drought, famine, and war to build defensive strongholds on remote cliffs. Contains photographs and paintings. (SV)

An Uncommon Cottage

ERIC Educational Resources Information Center

Carlson, Scott

2008-01-01

This article features the Cliffs Cottage, a "showcase home" at Furman University which demonstrates the use of green technology in residential building and teaches about sustainability. Custom-built for the shelter-magazine dreams of "Southern Living," a sponsor of the home, the house seems better suited for a tony subdivision.…

A Method for the Optimal Disposition of Surplus Air Force Motor Vehicles

DTIC Science & Technology

1991-09-01

refer to any management science text. A recommended source is Cook and Russell’s Introduction to Management Science (see Bibliography). Linear...Decisions. Wesley, London: Addison Wesley, 1978. Cook, Thomas and Robert A. Russell. Introduction to Management Science (Fourth Edition). Englewood Cliffs

Computer Networks and Information Warfare: Implications for Military Operations

DTIC Science & Technology

2000-07-01

specifically referring to this network.” Marshall T. Rose, The Simple Book: An Introduction to Management of TCP/IP based internets (Englewood...Cliffs, New Jersey: Prentice Hall, 1991), p. 2. 22. Marshall T. Rose, The Simple Book: An Introduction to Management of TCP/IP based internets

40 CFR 61.141 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Information on glove-bag installation, equipment and supplies, and work practices is contained in the... (or owner or operator under common control). Leak-tight means that solids or liquids cannot escape or... such as cliffs, lakes or other large bodies of water, deep and wide ravines, and mountains. Remoteness...

77 FR 64501 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-22

.... Applicants: Calvert Cliffs Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, R.E. Ginna Nuclear Power Plant, LLC. Description: Notice of Non-Material Change in Status of Nine Mile Point Nuclear..., LLC, Shooting Star Wind Project, LLC, Safe Harbor Water Power Corporation, PECO Energy Company...

78 FR 42060 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-15

... Harbor Water Power Corporation, PECO Energy Company, Michigan Wind 1, LLC, Michigan Wind 2, LLC, Harvest... Clearing, LLC, Cow Branch Wind Power, L.L.C., Constellation Power Source Generation Inc., Constellation New..., Calvert Cliffs Nuclear Power Plant, LLC, Nine Mine Point Nuclear Station, LLC. Description: Revised...

36 CFR 261.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... beneath the surface of the earth or within a cliff or ledge and which is large enough to permit a person... of the United States, national forest lands and waters acquired through purchase, exchange, donation... General Prohibitions § 261.2 Definitions. The following definitions apply to this part: Administrative...

76 FR 32857 - Great Outdoors Month, 2011

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-07

... Outdoors Month, 2011 By the President of the United States of America A Proclamation For generations... through stone-faced cliffs. During Great Outdoors Month, we rededicate ourselves to experiencing and... natural heritage. This month, let each of us resolve to protect our great outdoors; discover their wonders...

36 CFR 290.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the duties described in this part. Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is... hydrologic resources. National Forest System lands means all national forest lands reserved or withdrawn from...

36 CFR 290.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the duties described in this part. Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is... hydrologic resources. National Forest System lands means all national forest lands reserved or withdrawn from...

36 CFR 290.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the duties described in this part. Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is... hydrologic resources. National Forest System lands means all national forest lands reserved or withdrawn from...

36 CFR 290.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the duties described in this part. Cave means any naturally occurring void, cavity, recess, or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is... hydrologic resources. National Forest System lands means all national forest lands reserved or withdrawn from...

Terrestrial Ages of Antarctic Meteorites- Update 1999

NASA Technical Reports Server (NTRS)

Nishiizumi, Kunihiko; Welten, K. C.; Caffee, Marc W.

1999-01-01

We are continuing our ongoing study of cosmogenic nuclides in Antarctic meteorites. In addition to the studies of exposure histories of meteorites, we study terrestrial ages and pairing of Antarctic meteorites and desert meteorites. Terrestrial ages of Antarctic meteorites provide information on meteorite accumulation mechanisms, mean weathering lifetimes, and influx rates. The determination of Cl-36(half-life=3.01 x 10(exp 5) y) terrestrial ages is one of our long-term on-going projects, however, in many instances neither Cl-36 or C-14 (5,730 y) yields an accurate terrestrial age. Using Ca-14 (1.04 x 10(exp 5) y) for terrestrial age determinations solves this problem by filling the c,ap in half-life between 14-C and Cl-36 ages. We are now applying the new Ca-41- Cl-36 terrestrial age method as well as the Cl-36-Be-10 method to Antarctic meteorites. Our measurements and C-14 terrestrial age determinations by the University of Arizona group are always complementary. We have measured Cl-36 in over 270 Antarctic meteorites since our previous compilation of terrestrial ages. Since a large number of meteorites have been recovered from many different icefields in Antarctica, we continue to survey the trends of terrestrial ages for different icefields. We have also measured detailed terrestrial ages vs. sample locations for Allan Hills, Elephant Moraine, and Lewis Cliff Icefields, where meteorites have been found with very long ages. The updated histograms of terrestrial ages of meteorites from the Allan Hills Main Icefield and Lewis Cliff Icefield are shown. These figures include C-14 ages obtained by the University of Arizona group. Pairs of meteorites are shown as one object for which the age is the average of all members of the same fall. The width of the bars represents 70,000 years, which was a typical uncertainty for Cl-36 ages. We reduced the uncertainty of terrestrial age determinations to approx. 40,000 years by using pairs of nuclides such as Ca-41-Cl-36 or Cl-36-Be-10. Meteorites found at the Allan Hills Icefields are much older than any other meteorites. The terrestrial ages cover a wide range and are as old as 2 My. Many of the Lewis Cliff meteorites are as old as the Allan Hills meteorites. So far, no clear correlation has been found between the terrestrial ages and the locations of the Lewis Cliff meteorites.

3D Modelling of Inaccessible Areas using UAV-based Aerial Photography and Structure from Motion

NASA Astrophysics Data System (ADS)

Obanawa, Hiroyuki; Hayakawa, Yuichi; Gomez, Christopher

2014-05-01

In hardly accessible areas, the collection of 3D point-clouds using TLS (Terrestrial Laser Scanner) can be very challenging, while airborne equivalent would not give a correct account of subvertical features and concave geometries like caves. To solve such problem, the authors have experimented an aerial photography based SfM (Structure from Motion) technique on a 'peninsular-rock' surrounded on three sides by the sea at a Pacific coast in eastern Japan. The research was carried out using UAS (Unmanned Aerial System) combined with a commercial small UAV (Unmanned Aerial Vehicle) carrying a compact camera. The UAV is a DJI PHANTOM: the UAV has four rotors (quadcopter), it has a weight of 1000 g, a payload of 400 g and a maximum flight time of 15 minutes. The camera is a GoPro 'HERO3 Black Edition': resolution 12 million pixels; weight 74 g; and 0.5 sec. interval-shot. The 3D model has been constructed by digital photogrammetry using a commercial SfM software, Agisoft PhotoScan Professional®, which can generate sparse and dense point-clouds, from which polygonal models and orthophotographs can be calculated. Using the 'flight-log' and/or GCPs (Ground Control Points), the software can generate digital surface model. As a result, high-resolution aerial orthophotographs and a 3D model were obtained. The results have shown that it was possible to survey the sea cliff and the wave cut-bench, which are unobservable from land side. In details, we could observe the complexity of the sea cliff that is nearly vertical as a whole while slightly overhanging over the thinner base. The wave cut bench is nearly flat and develops extensively at the base of the cliff. Although there are some evidences of small rockfalls at the upper part of the cliff, there is no evidence of very recent activity, because no fallen rock exists on the wave cut bench. This system has several merits: firstly lower cost than the existing measuring methods such as manned-flight survey and aerial laser scanning. Secondly, compared to these other methods, the one the authors have presented also enables frequent measurements. Thirdly lightweight and compact system realizes higher applicability to various fields. However, the method is still in need of development, as the measurable range is narrower than the other airborne methods, normally up to several hectares, and data accuracy of coordinate and elevation is unknown from SfM alone.

Impact of climate change on zooplankton communities, seabird populations and arctic terrestrial ecosystem—A scenario

NASA Astrophysics Data System (ADS)

Stempniewicz, Lech; Błachowiak-Samołyk, Katarzyna; Węsławski, Jan M.

2007-11-01

Many arctic terrestrial ecosystems suffer from a permanent deficiency of nutrients. Marine birds that forage at sea and breed on land can transport organic matter from the sea to land, and thus help to initiate and sustain terrestrial ecosystems. This organic matter initiates the emergence of local tundra communities, increasing primary and secondary production and species diversity. Climate change will influence ocean circulation and the hydrologic regime, which will consequently lead to a restructuring of zooplankton communities between cold arctic waters, with a dominance of large zooplankton species, and Atlantic waters in which small species predominate. The dominance of large zooplankton favours plankton-eating seabirds, such as the little auk ( Alle alle), while the presence of small zooplankton redirects the food chain to plankton-eating fish, up through to fish-eating birds (e.g., guillemots Uria sp.). Thus, in regions where the two water masses compete for dominance, such as in the Barents Sea, plankton-eating birds should dominate the avifauna in cold periods and recess in warmer periods, when fish-eaters should prevail. Therefore under future anthropogenic climate scenarios, there could be serious consequences for the structure and functioning of the terrestrial part of arctic ecosystems, due in part to changes in the arctic marine avifauna. Large colonies of plankton-eating little auks are located on mild mountain slopes, usually a few kilometres from the shore, whereas colonies of fish-eating guillemots are situated on rocky cliffs at the coast. The impact of guillemots on the terrestrial ecosystems is therefore much smaller than for little auks because of the rapid washing-out to sea of the guano deposited on the seabird cliffs. These characteristics of seabird nesting sites dramatically limit the range of occurrence of ornithogenic soils, and the accompanying flora and fauna, to locations where talus-breeding species occur. As a result of climate warming favoring the increase of ichthyiofagous cliff-nesting seabirds, we can expect that large areas of ornithogenic tundra around the colonies of plankton-eating seabirds situated far from the sea may disappear, while areas of tundra in the vicinity of cliffs inhabited by fish-eating seabirds, with low total production and supporting few large herbivores, will likely increase, but only imperceptibly. This may lead to habitat fragmentation with negative consequences for populations of tundra-dependent birds and mammals, and the possibility of a substantial decrease in biodiversity of tundra plant and animal communities.

Geological controls on hillslope-failure mechanisms during the 2010-2011 earthquake sequence in suburban Christchurch, New Zealand

NASA Astrophysics Data System (ADS)

McSaveney, M. J.; Massey, C. I.; Wang, G.

2012-12-01

Parts of the city of Christchurch NZ were severely damaged when a series of shallow aftershocks from the Mw 7.1 Darfield earthquake of 4 Sept. 2010 occurred beneath the city. Hillside suburbs are on the flanks of an extinct and deeply dissected Miocene basalt volcano which is widely mantled by Pleistocene loess. Portions of the lower flanks of the volcano have been cliffed by late Holocene marine erosion. Highly prized cliff-top homes overlook the city with a backdrop of the Southern Alps, or a seascape of the south Pacific Ocean. Here we discuss how various hillslope materials responded in different ways to the unusually high ground accelerations in the hillside suburbs. Most ground damage occurred in two major aftershocks: the Mw 6.2 Christchurch earthquake of 22 Feb. 2011, in which 184 people died, and a Mw 6.2 aftershock of 13 June 2011. Ground accelerations in these earthquakes were recorded locally in excess of 2 g. Significant ground damage occurred in 3 other strong aftershocks, although minor rockfalls were observed in many smaller aftershocks of which there were thousands. In the highest ground accelerations, many loose hillside objects were thrown into the air. More than 5000 loose basalt boulders were thrown or toppled from steep slopes to roll through residential properties on the slopes below. In addition, cliff tops and faces crumbled into debris avalanches. In the 13 June earthquake a geotechnical witness on a cliff top described ground cracks opening and closing around him as he scrambled off the collapsing cliff edge during the strong cyclic shaking. Loess landslides were a relative minor but damaging component. Dynamic ring-shear testing showed that the loess fails during amplified strong ground shaking, but shear displacement stops soon after, so that the earthquake-triggered loess landslides move only during strong earthquakes. Detected minor lateral movement in strongly weathered basaltic tuff and basaltic lava breccia is a cause of concern because deep weathering has left a rock composed largely of plagioclase, goethite, and pore space, with minor clay minerals. Dynamic ring-shear testing revealed some alarming properties. A remolded sample was initially unresponsive to amplified strong earthquake loading, but failed catastrophically (shear strain continuing long after the end of strong shaking) on the third seismic challenge. Shear resistance was strongly rate dependent, with shear resistance reducing with increasing strain rate. No catastrophic landslides of these weathered materials have occurred in the brief historic period, but the potential for them to occur gives new emphasis to their further investigation.

76 FR 55937 - Sheldon National Wildlife Refuge, Washoe and Humboldt Counties, NV, and Lake County, OR; Draft...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-09

... of wetland, riparian, desert grassland, and shrub-steppe habitats, with emphasis on removing feral... primarily shrub-steppe uplands, but also include important springs and spring brooks, basalt cliffs and... reasonable, scientifically- grounded guidance for improving the Refuge's shrub-steppe, riparian, wetland, and...

78 FR 71643 - Certain Wireless Consumer Electronics Devices and Components Thereof; Commission Determination To...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... Electronics Devices and Components Thereof; Commission Determination To Review in Part A Final Initial... sale within the United States after importation of certain wireless consumer electronics devices and... Electronics, Inc. of Seoul, Korea and LG Electronics U.S.A., Inc. of Englewood Cliffs, New Jersey...

67. Photocopy of photograph (original print in the Minnesota Historical ...

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

67. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul Minnesota, ca. 1925. #35109. Photographer: St. Paul Daily News.) VIEW TO NORTHEAST, SHOWING SPAN NOS. 9-19, ca. 1925 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

63. Photocopy of photograph (original print in the Minnesota Historical ...

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

63. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1958. #31008. Photographer: St. Paul Dispatch-Pioneer Press.) AERIAL VIEW OF HIGH BRIDGE, LOOKING SOUTHWEST, 1958 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

68. Photocopy of photograph (original print in the Minnesota Historical ...

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

68. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1924. #35108. Photographer: St. Paul Daily News.) VIEW TO EAST, SHOWING SPAN NOS. 10-20, 1924 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

70. Photocopy of photograph (original print in the Minnesota Historical ...

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

70. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1904. #18613g. Photographer: Albert Munson) VIEW TO WEST, SHOWING FALSEWORK USED IN RECONTRUCTING THE HIGH BRIDGE, 1904. - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

71. Photocopy of photograph (original print in the Minnesota Historical ...

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

71. Photocopy of photograph (original print in the Minnesota Historical Society, St. Pal, Minnesota, ca. 1905. #30454.) VIEW TO NORTHWEST, POSSIBLY AFTER THE REOPENING OF THE BRIDGE IN MAY 1905 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

77 FR 16278 - Advisory Committee on Reactor Safeguards: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-20

..., 11545 Rockville Pike, Rockville, Maryland. Thursday, April 12, 2012, Conference Room T2-B1, 11545....: Selected Chapters of the Safety Evaluation Report (SER) with Open Items Associated with the Calvert Cliffs... chapters of the NRC staff's Safety Evaluation Report (SER) with open items associated with the Calvert...

American Taxpayer Relief Act of 2012

THOMAS, 112th Congress

Rep. Camp, Dave [R-MI-4

2012-07-24

01/02/2013 Became Public Law No: 112-240. (TXT | PDF) (All Actions) Notes: Enactment of the "fiscal cliff bill" averted scheduled income tax rate increases and the spending reductions required by the sequestration process. Tracker: This bill has the status Became LawHere are the steps for Status of Legislation:

K-12 Urban Career Education Infusion Project. Final Evaluation

ERIC Educational Resources Information Center

Denton, William T.; Kleck, Wil

The K-12 Urban Career Education Infusion Project of the Dallas (Texas) Independent School District focused on fourteen schools located in the East Oak Cliff Subdistrict, a predominantly (98%) black community. Conducted in two phases, the project attempted to demonstrate that through infusing career education into the existing curriculum, trained…

How Selected High School Newspapers Covered the Persian Gulf War.

ERIC Educational Resources Information Center

Peterson, Jane W.; Maronn, Michelle

1995-01-01

Discusses the many ways in which high school newspapers covered the Persian Gulf War, ranging from a serious analysis to satire in the form of a Cliff Notes summary. Compares two editorials from "The Little Hawk" (Iowa City, Iowa), one supporting the war and the other against. (PA)

Center for Adaptive Optics | Home

Science.gov Websites

Center for Adaptive Optics A University of California Science and Technology Center home Directions to The Center for Adaptive Optics Building Directions to the Center for Adaptive Optics Building * Seaway Inn * West Cliff Inn Last Modified: Apr 3, 2012 Center for Adaptive Optics | Search | The Center

The Relationship between Performance and Satisfaction: A Utility Analysis.

DTIC Science & Technology

1985-03-01

Journal of Applied Psychology, 52, 343-347. 21 Korman, A.K. (1980) Career success /personal failure. Englewood Cliffs, N.J.: Prentice Hall. Lawler...this extensively in his book Career Success / Personal Failure (1980). Korman quotes from Matters (1976, p. 124): "After you’ve sold widgets for twenty

77 FR 16543 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

...: Docket Numbers: ER10-2179-007; ER10-2181-007; ER10-2182-007. Applicants: R.E. Ginna Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, Calvert Cliffs Nuclear Power Plant, LLC. Description.... Applicants: Pioneer Trail Wind Farm, LLC. Description: Application for Authorization Under Section 203 of the...

78 FR 9903 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

...-2181-016; ER10-2182-016. Applicants: R.E. Ginna Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC, Calvert Cliffs Nuclear Power Plant, LLC. Description: Notice of Non-Material Change in... Wind Power, L.L.C., CR Clearing, LLC, Criterion Power Partners, LLC, Exelon Framingham, LLC, Exelon...

76 FR 1416 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-10

... Wind Farm LLC; State Line Energy, LLC; Kincaid Generation, L.L.C.; Virginia Electric and Power Company...: Constellation Energy Commodities Group, R.E. Ginna Nuclear Power Plant, LLC, AES NewEnergy, Inc., Baltimore Gas..., Safe Harbor Water Power Corporation, Calvert Cliffs Nuclear Power Plant LLC, CER Generation, LLC...

Individual Attitudes and Social Influences on College Students' Intent to Participate in Study Abroad Programs

ERIC Educational Resources Information Center

Wang, Liz C.; Gault, John; Christ, Paul; Diggin, Patricia A.

2016-01-01

Participation in study abroad programs (SAPs) is widely viewed as offering important professional and personal benefits for college students. This study applies the "Theory of Reasoned Action" [Ajzen, I., & Fishbein, M. (1980) and "Understanding attitudes and predicting social behavior," Englewood Cliffs, NJ:…

An Empirical Study to Enhance the Reenlistment Process of Civilian Personnel with Prior Military Service.

DTIC Science & Technology

1985-04-01

Analysis. Beverly Hills, CA: Sage Publica- tions, 1980. Kotler , P. Principles of Marketing. Englewood Cliffs, NJ: Prentice- Hall, Inc., 1980...02940 Mr. Philip Bernard B-K Dynamics, Inc. 15825 Shady Grove Road Rockville, MD 20850 Dr. Bruce M. Meglino College of Business Administration

Implementing a Quality Needs Assessment

ERIC Educational Resources Information Center

Cuiccio, Cary

2012-01-01

Districts nationwide are facing budget cuts that, to some, feel more like funding cliffs. Accordingly, school teams are re-examining their personnel, programs, and schedules so that they can make difficult decisions about where to spend resources to realize the greatest improvement. The principals who are able to make decisions with data from…

Explicit, Implicit, and Subjective Rating Measures of Situation Awareness in a Monitoring Task

DTIC Science & Technology

1991-10-01

range of the subjects’ weapon (referred to as "envelope sensitivity" and calculated as A’ see Macmillan and Creelman , 1990). In his experiment...1982). Design and analysis: A researchers handbook. Englewood Cliffs, NJ: Prentice-Hall. Macmillan, N. A., and Creelman , C. D. (1990). Response

1984 Directory of Experts on Organization and Management of Construction.

DTIC Science & Technology

1984-02-01

Action & Services Expert on the Panal of: World Bank, Asian Development Bank, Commonwealth Fund for Technical Cooneration, U.N. Centre for Human...Hall, Inc., Englewood Cliffs, New Jersey, 1977 Nunnally, S. W., and R. F. DeBruhl, Final Report, North Carolina Home Builders Passive Solar Program

49 CFR Appendix F to Subchapter B... - Commercial Zones

Code of Federal Regulations, 2011 CFR

2011-10-01

....J.; the area within the borough limits of Alpine, Tenafly, Englewood Cliffs, Leonia, Fort Lee... along U.S. Highway 40 to its junction with the Lee's Summit, Mo., corporate limits. Thence along the eastern Lee's Summit corporate limits to the Jackson-Cass County line, thence west along Jackson-Cass...

The potential of low-cost RPAS for multi-view reconstruction of rock cliffs

NASA Astrophysics Data System (ADS)

Ettore Guccione, Davide; Thoeni, Klaus; Santise, Marina; Giacomini, Anna; Roncella, Riccardo; Forlani, Gianfranco

2016-04-01

RPAS, also known as drones or UAVs, have been used in military applications for many years. Nevertheless, the technology has become accessible to everyone only in recent years (Westoby et al., 2012; Nex and Remondino, 2014). Electric multirotor helicopters or multicopters have become one of the most exciting developments and several off-the-shelf platforms (including camera) are now available. In particular, RPAS can provide 3D models of sub-vertical rock faces, which for instance are needed for rockfall hazard assessments along road cuts and very steep mountains. The current work investigates the potential of two low-cost off-the-shelf quadcopters equipped with digital cameras for multi-view reconstruction of sub-vertical rock cliffs. The two platforms used are a DJI Phantom 1 (P1) equipped with a Gopro Hero 3+ (12MP) and a DJI Phantom 3 Professional (P3). The latter comes with an integrated 12MP camera mounted on a 3-axis gimbal. Both platforms cost less than 1.500€ including camera. The study area is a small rock cliff near the Callaghan Campus of the University of Newcastle (Thoeni et al., 2014). The wall is partly smooth with some evident geological features such as non-persistent joints and sharp edges. Several flights were performed with both cameras set in time-lapse mode. Hence, images were taken automatically but the flights were performed manually since the investigated rock face is very irregular which required adjusting the yaw and roll for optimal coverage since the flights were performed very close to the cliff face. The digital images were processed with a commercial SfM software package. Thereby, several processing options and camera networks were investigated in order to define the most accurate configuration. Firstly, the difference between the use of coded ground control targets versus natural features was studied. Coded targets generally provide the best accuracy but they need to be placed on the surface which is not always possible as rock cliffs are not easily accessible. Nevertheless, work natural features can provide a good alternative if chosen wisely. Secondly, the influence of using fixed interior orientation parameters and self-calibration was investigated. The results show that in the case of the used sensors and camera networks self-calibration provides better results. This can mainly be attributed to the fact that the object distance is not constant and rather small (less than 10m) and that both cameras do not provide an option for fixing the interior orientation parameters. Finally, the results of both platforms are as well compared to a point cloud obtained with a terrestrial laser scanner where generally a very good agreement is observed. References Nex, F., Remondino, F. (2014) UAV for 3D mapping applications: a review. Applied Geomatics 6(1), 1-15. Thoeni, K., Giacomini, A., Murtagh, R., Kniest, E. (2014) A comparison of multi-view 3D reconstruction of a rock wall using several cameras and a laser scanner. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-5, 573-580. Westoby, M.J., Brasington, J., Glasser, N.F., Hambrey, M.J., Reynolds, J.M. (2012) 'Structure-from-Motion' photogrammetry: A low-cost, effective tool for geoscience applications. Geomorphology 179, 300-314.

Richat Structure, Mauritania, Anaglyph, Landsat Image over SRTM Elevation

NASA Technical Reports Server (NTRS)

2004-01-01

The prominent circular feature seen here, known as the Richat Structure, in the Sahara desert of Mauritania, is often noted by astronauts because it forms a conspicuous 50-kilometer-wide (30-mile-wide) bull's-eye on the otherwise rather featureless expanse of the desert. Initially mistaken for a possible impact crater, it is now known to be an eroded circular anticline (structural dome) of layered sedimentary rocks.

Extensive sand dunes occur in this region and the interaction of bedrock topography, wind, and moving sand is evident in this scene. Note especially how the dune field generally ends abruptly short of the cliffs as wind from the northeast (upper right) apparently funnels around the cliff, sweeping clean areas near the base of the cliff (particularly at the cliff point to the northwest, upper left, of the Richat Structure). Note also the isolated peak within the dune field. That peak captures some sand on its windward side, but mostly deflects the wind and sand around its sides, creating a sand-barren streak that continues far downwind.

To the west (left), a north-south trending bedrock ridge breaks up the sand field, and downwind from the ridge, streaks of dunes occur at certain locations. Upon close inspection, these streaks can be seen to be associated with saddles (low points) along the ridge, where sand preferentially passes over the ridge. This again shows how topographic features control the distribution of sand across the terrain.

This anaglyph was created by draping a Landsat reflectance infrared image over an SRTM elevation model, and then generating two differing perspectives, one for each eye. When viewed through special glasses, the anaglyph 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 For vertical scale, note that the prominent cliffs (image center) are about 300 meters (about 1000 feet) tall, the central rings of the Richat structure are about 80 meters (about 260 feet) tall, and the sand dunes rise about 80 meters (about 260 feet) above the adjacent terrain across the center of the image.

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

Size: 174.6 kilometers (108.3 miles) by 112.5 kilometers (69.8 miles) Location: 21.4 degrees North latitude, 12.0 degrees West longitude Orientation: North toward the top Image Data: Landsat band 7 Date Acquired: February 2000 (SRTM), January 13, 1987 (Landsat)

Roger Lake research natural area: guidebook supplement 29.

Treesearch

J. Dana Visalli

2006-01-01

Roger Lake Research Natural Area (RNA), a 174.7-ha reserve in north-central Washington, contains a rich diversity of landforms, plant communities, and wildlife habitats. Spreading outward from the lake itself, sedge and sphagnum fens give way to upland coniferous forest, granitic cliffs, and a relictual, high-altitude big sagebrush-whitebark pine (Artemisia tridentata-...

77 FR 5820 - Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Massachusetts-Call for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... submitting such information as a separate attachment. Treatment of confidential information is addressed in... the cliffs, changes to sediment transport, and impacts to grey seal breeding areas (Muskeget being... and pursue measures to minimize and fully mitigate impacts to tribal cultural, wildlife, water and...

Consistent Small-Sample Variances for Six Gamma-Family Measures of Ordinal Association

ERIC Educational Resources Information Center

Woods, Carol M.

2009-01-01

Gamma-family measures are bivariate ordinal correlation measures that form a family because they all reduce to Goodman and Kruskal's gamma in the absence of ties (1954). For several gamma-family indices, more than one variance estimator has been introduced. In previous research, the "consistent" variance estimator described by Cliff and…

72. Photocopy of photograph (original print in the Minnesota Historical ...

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

72. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, June 25, 1958. #31024. Photographer: St. Paul Dispatch-Pioneer Press. VIEW TO SOUTH, SHOWING THE RESURFACING OF THE BRIDGE IN 1958 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

64. Photocopy of photograph (original print in the Minnesota Historical ...

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

64. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul Minnesota, ca. 1891. #35805. Photographer: Haynes and Bros., St. Paul.) VIEW TO SOUTH, SHOWING FOUR PERCENT GRADE OF HIGH BRIDGE, ca. 1981 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

The Online Learning Imperative: A Solution to Three Looming Crises in Education

ERIC Educational Resources Information Center

Wise, Bob

2010-01-01

Currently, K-12 education in the United States is dealing with three major challenges: (1) global skill demands versus educational attainment; (2) the funding cliff; and (3) a looming teacher shortage. Independently, these factors present significant challenges. In combination, they create a national imperative for swift action to create a more…

78 FR 70078 - Advisory Committee on Reactor Safeguards; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

... Pike, Rockville, Maryland. Wednesday, December 4, 2013, Conference Room T2-B1, 11545 Rockville Pike....: Selected Chapters of the Safety Evaluation Report (SER) With Open Items Associated With the Calvert Cliffs...)(4).] 10:45 a.m.-12:45 p.m.: Topical Report and Selected Chapters of the Safety Evaluation Reports...

Molecular Mechanics with an Array Processor.

DTIC Science & Technology

1982-06-01

34 to be submritted. 40 B. W. Kernrihan and D M Ritchie, The CPm guniw.g Language, Prentice- Hall. Eaglewood Cliffs, New Jersey, 1978. 60 D. J. Adams , in...1400 Washington Avenue Ban e o Albany, New York 12203 La J la, California 92093 Dr. Rank Loos Professor C. A. Ansell Latuna Research Laboratory

Introduction to Financial Management for Foreign Military Staff Officers

DTIC Science & Technology

1991-06-01

House: New York, 1986. 5. Ishikawa , Kaoru . What is Total Quality Control? The Japanese Way. Prentice-Hall: Englewood Cliffs, NJ., 1985. 6. Juran, J. M...the key to process improvement is the infinite human potential of an organization’s people." 5 [ Ishikawa , 85) 6. Processes, not people, are the root

The Navy’s Quality Journey: Operational Implementation of TQL

DTIC Science & Technology

1993-04-01

training. Dr. Kaoru Ishikawa "Guide to Ouality Control" "QC begins with education and ends with education. To implement TQC, we need to carry out...York: McGraw-Hill, 1986. 20. Ishikawa , Kaoru . What is Total Qualit Control? Englewood Cliffs, NJ: Prentice-Hall, Inc., 1985. 21. Ishikawa , Kaoru

The Organization of Wariness of Heights in Experienced Crawlers

ERIC Educational Resources Information Center

Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J.; Dahl, Audun; Anderson, David I.

2012-01-01

Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos, Bertenthal, & Kermoian, 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these "nonavoiders" lack wariness…

4. Tower entrance wing, covered way, keeper's house and shed, ...

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

4. Tower entrance wing, covered way, keeper's house and shed, view west northwest, northeast side of wing and covered way, southeast and northeast sides of keeper's house, southwest and southeast sides of shed - Burnt Island Light Station, Burnt Island, west side of entrance to Boothbay Harbor, Pine Cliff, Lincoln County, ME

Seriously Data-Driven Decision Making

ERIC Educational Resources Information Center

Casserly, Michael D.

2011-01-01

As states approach the funding cliff marking the end of federal stimulus help for education, school districts will be feeling more financial pain than they're experiencing now. But there's good news amid the bad: Big city districts are showing schools nationwide a way to save money and improve efficiency by working together. They've created the…

Career Selection Education Program, 1965-1968. Report.

ERIC Educational Resources Information Center

Digneo, Ellen Hartnett, Ed.; Shaya, Tila, Ed.

Career Selection Education Programs were conducted during the 1965-66 school year at Cloudcroft and Weed High Schools under the direction of personnel from New Mexico State University, and at Cliff High School under the direction of personnel from Western New Mexico University. These programs were designed specifically to enable young people in…

Strategic Studies Quarterly. Volume 9, Number 1. Spring 2015

DTIC Science & Technology

2015-01-01

Cliff, and Phillip C. Saunders (Washington, DC: NDU Press, 2012), 78-79. 72. Murray Scot Tanner, "The Missions of the People’s Liberation Army Air...October 2013), http://issuu.com/ewipublications/docs /mcp_final_l 0_22_2013/4. 23. James Wood Forsyth Jr., "What Great Powers Make It: International

Assessing Organization Culture Readiness for Knowledge Management Implementation: The Case of Aeronautical Systems Center Directorate of Contracting

DTIC Science & Technology

2003-03-01

effective change management techniques (Gibson, Ivancevich , & Donnelly, 2001). Based on case study 15 research, KM projects require more...Englewood Cliffs, NJ: Prentice Hall. 1986. Gibson, J.L., J.M. Ivancevich , and J.H. Donnelly Jr. Organizations. (10th ed.). Boston: Irwin McGraw-Hill

The Influence of Quality Circles on Attitudinal Outcomes Among Civil Engineering Personnel.

DTIC Science & Technology

1985-09-01

whatsoever since 1977 (Donnelly, Gibson, & Ivancevich , 1984). From 1950 to 1980, however, Japan’s annual productivity growth rate has been four times...Cliffs NJ: Pren"ce-Ha11, 1980. Donnelly, James H. Jr., James L. Gibson, and John M. Ivancevich . Fundamentals of Management (Fifth Edition). Plano TX

A Place to Stay: Building Green

ERIC Educational Resources Information Center

Deal, Walter F.

2010-01-01

Shelter has been a concern of humans and animals alike for the millennia. Animals, through their natural instincts, build nests and shelters to meet their needs for protection against predators and seasonal changes in the weather. Early humans sought shelter in caves and cliff dwellings and later began to design and build shelters based on the…

During-Treatment Outcomes among Female Methamphetamine-Using Offenders in Prison-Based Treatments

ERIC Educational Resources Information Center

Rowan-Szal, Grace A.; Joe, George W.; Simpson, D. Dwayne; Greener, Jack M.; Vance, Jerry

2009-01-01

An increasingly important treatment group is the expanding population of methamphetamine-using female offenders. This study focused on women methamphetamine-using offenders (n = 359) who were treated either in a modified therapeutic community (TC) program ("Clean Lifestyle is Freedom Forever" [CLIFF]-TC: n = 234) designed for non-violent offenders…

Successful Insurgent Revolutions in Latin America: Analysis of the Cuban and Nicaraguan Revolutions

DTIC Science & Technology

2014-03-01

Thomas H. Greene, Comparative Revolutionary Movements: Search for Theory and Justice, 3rd ed. (Englewood Cliffs, NJ: Prentice- Hall Contemporary...Revolution, Insurgency, Leadership, Popular Support, External Influence, Military, Insurgent Life Cycle, Theories of Revolution, Cuban Revolution, M-26-7...REVOLUTIONS .............................................. 17   A.   THEORIES OF REVOLUTION

The role of landscape anomalies in regional plant conservation

Treesearch

S. Kelso; C. Hall; G. Maentz

2001-01-01

Landscape anomalies are regionally restricted habitats created by unusual geologic, edaphic, or hydrologic factors. Barrens, cliff faces, canyons, hanging gardens, and playas are all examples of landscape anomalies in the arid Southwest. Such sites often harbor an unusual and rich flora, including endemic, disjunct, or relictual plant species. Using examples from our...

States Hurt as Stimulus Loses Steam

ERIC Educational Resources Information Center

Cavanagh, Sean; Hollingsworth, Heather

2011-01-01

States are finally arriving at the "funding cliff"--the point where about $100 billion in federal economic-stimulus aid for education runs out. The loss seems certain to compound severe budget woes and could mean thousands of school layoffs and the elimination of popular programs and services in districts across the country. The bulk of…

Motivating the Notion of Generic Design within Information Processing Theory: the Design Problem Space

DTIC Science & Technology

1988-12-09

company or a social welfare policy for a state. On this account, anyone dissatisfied with existing states of affairs and attempting to transform them into...Norman Cliff Dipartimento di Psicologia Department of Psychology Via della Pergola 48 Univ. of So. California 50121 Firenze Los Angeles, CA 90089-1061

77 FR 73027 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-07

...-2179-013; ER10-2181-013; ER10-2182-013. Applicants: R.E. Ginna Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, LLC, Nine Mile Point Nuclear Station, LLC. Description: Supplement to July 6, 2012...: Southwest Power Pool, Inc. Description: 2501 Waverly Wind Farm, LLC GIA to be effective 11/14/ 2012. Filed...

77 FR 5842 - Notice of Inventory Completion: Minnesota Indian Affairs Council, Bemidji, MN

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

..., Crow Wing, and Kanabec. This notice is published as part of the National Park Service's administrative... the Minnesota Chippewa Tribe, Minnesota; Minnesota Chippewa Tribe, Minnesota; Red Cliff Band of Lake... University (Acc. 103). The mound may have been located in either Crow Wing County, MN or Morrison County, MN...

Development of a Knowledge Base for Use in an Expert System Advisor for Aircraft Maintenance Scheduling (ESAAMS)

DTIC Science & Technology

1991-03-01

Cliffs, New Jersey, 1989. Merritt, Dennis, "Forward Chaining in Prolog," Al Expert, v.7 November 1986. Minsky , Marvin ., "A Framework for Representing... Minsky , Marvin , (editor), Semantic Information Processing, MIT Press, 1968. Rychener, M. D., Production Systems as a Programming Language for Artificial

75 FR 65294 - Southern Maryland Electric Cooperative: Notice of Finding of No Significant Impact

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... Significant Impact (FONSI) for the Environmental Assessment (EA) associated with the Holland Cliff to Hewitt Road 230 kV Transmission proposal in Calvert and St. Mary's Counties, Maryland. The EA was prepared..., Environmental Policies and Procedures). The purpose of the EA was to evaluate the potential environmental...

A comparison of artifical and natural slope failures: the Santa Barbara earthquake of August 13, 1978.

USGS Publications Warehouse

Harp, E.L.; Keefer, D.K.; Wilson, R.C.

1980-01-01

The earthquake triggered rockfalls and rockslides from steep road cuts and coastal cliffs. The landslide reconnaissance survey which was carried out is described, with separate comments on each landslide site recorded. The general regional slope response to the earthquake is briefly considered. -R. House

Predicting Achievement, Distress, and Retention among Lower-Income Latino Youth

ERIC Educational Resources Information Center

Close, Wendy; Solberg, Scott

2008-01-01

This study used structural equation modeling to evaluate whether a combination of social cognitive and self-determination theories [Bandura, A. (1986). "Social foundations of thought and action: A social cognitive theory." Englewood Cliffs, NJ: Prentice-Hall; Deci, E. L., & Ryan, R. M. (1987). The support of autonomy and the control of behavior.…

Walking the Cliff's Edge: The "New Nation's" Rhetoric of Resistance in Apartheid South Africa

ERIC Educational Resources Information Center

Trabold, Bryan

2009-01-01

This article examines the rhetoric of resistance used by South African anti-apartheid journalists to expose the links between the apartheid government and death squads. By utilizing allusions, repetition, and a concept I refer to as "subversive enthymemes," these journalists managed to reveal publicly information about death squad…

Geotourism of Batu Dinding Kilo Tiga, Amurang District, South Minahasa Regency, North Sulawesi - Indonesia

NASA Astrophysics Data System (ADS)

Elvien Kristian, V. A.; Ridho, Ahmad; Diaz Alffi, Febriany

2018-03-01

Start your abstract Batu Dinding Kilo Tiga or famously called Batu Dinding is one of tourist destinations in Kilo Tiga village, Amurang district, South Minahasa regency, North Sulawesi. In terms of Geology, Batu Dinding is a rock cliff with columnar structure and constituted in the form of andesitic thrakit rocks which is one of intermediate igneous rocks of volcanic aged Late Tertiary until Early Quarter, precisely during the Pleistocene. The structure and appearance of Batu Dinding was like a ladder, make Batu Dinding in demand as a destination for wall climbing or cliff hanger. The area around the Batu Dinding, there are Pamurapa River that at a time when it was high tide, can be used for rafting. Unfortunately, the accommodation and accessibility of the Amurang Batu Dinding are poor, causing Batu Dinding rarely to visit. The aim of the paper is to introduce as well as media publications of Batu Dinding tourism in order to increase local income and in addition it can be as a geological site for learning purposes.

Vascular Plant and Vertebrate Inventory of Montezuma Castle National Monument

USGS Publications Warehouse

Schmidt, Cecilia A.; Drost, Charles A.; Halvorson, William Lee

2006-01-01

Executive Summary We summarize past inventory efforts for vascular plants and vertebrates at Montezuma Castle National Monument (NM) in Arizona. We used data from previous research to compile complete species lists for the monument and to assess inventory completeness. There have been 784 species recorded at Montezuma Castle NM, of which 85 (11%) are non-native. In each taxon-specific chapter we highlight areas of resources that contributed to species richness or unique species for the monument. Of particular importance are Montezuma Well and Beaver and Wet Beaver creeks and the surrounding riparian vegetation, which are responsible for the monument having one of the highest numbers of bird species in the Sonoran Desert Network of park units. Beaver Creek is also home to populations of federally-listed fish species of concern. Other important resources include the cliffs along the creeks and around Montezuma Well (for cliff and cave roosting bats). Based on the review of past studies, we believe the inventory for most taxa is nearly complete, though some rare or elusive species will be added with additional survey effort. We recommend additional inventory, monitoring and research studies.

Mazus sunhangii (Mazaceae), a New Species Discovered in Central China Appears to Be Highly Endangered.

PubMed

Deng, Tao; Zhang, Xiao-Shuang; Kim, Changkyun; Zhang, Jian-Wen; Zhang, Dai-Gui; Volis, Sergei

2016-01-01

Mazus sunhangii, a new species of Mazaceae from central China is described and illustrated based on evidence from morphology and molecular phylogeny. This new species is morphologically similar to M. puchellus and M. omeiensis but differs in erect habit, inflorescence position, leaf pattern and corolla color. Phylogenetic analysis based on four chloroplast DNA regions (rbcL, rps16, trnL-F, and psbA-trnH) identified the new species as the independent lineage sister to the other East Asian Mazus species. The new species is known only from a single location in Mt. Shennongjia area in northwest Hubei province, at the elevation of 760 m. The species grows on the limestone cliff, and, because a tourist arterial highway is located along this cliff, its habitat can be easily disturbed or destroyed. We propose that the only known species location is recognized as critical habitat (i.e., as the habitat required to ensure the persistence of a species) and the species listed as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.

Cliff-edge model of obstetric selection in humans.

PubMed

Mitteroecker, Philipp; Huttegger, Simon M; Fischer, Barbara; Pavlicev, Mihaela

2016-12-20

The strikingly high incidence of obstructed labor due to the disproportion of fetal size and the mother's pelvic dimensions has puzzled evolutionary scientists for decades. Here we propose that these high rates are a direct consequence of the distinct characteristics of human obstetric selection. Neonatal size relative to the birth-relevant maternal dimensions is highly variable and positively associated with reproductive success until it reaches a critical value, beyond which natural delivery becomes impossible. As a consequence, the symmetric phenotype distribution cannot match the highly asymmetric, cliff-edged fitness distribution well: The optimal phenotype distribution that maximizes population mean fitness entails a fraction of individuals falling beyond the "fitness edge" (i.e., those with fetopelvic disproportion). Using a simple mathematical model, we show that weak directional selection for a large neonate, a narrow pelvic canal, or both is sufficient to account for the considerable incidence of fetopelvic disproportion. Based on this model, we predict that the regular use of Caesarean sections throughout the last decades has led to an evolutionary increase of fetopelvic disproportion rates by 10 to 20%.

Microbenthic distribution of Proterozoic tidal flats: environmental and taphonomic considerations

NASA Technical Reports Server (NTRS)

Kah, L. C.; Knoll, A. H.

1996-01-01

Silicified carbonates of the late Mesoproterozoic to early Neoproterozoic Society Cliffs Formation, Baffin Island, contain distinctive microfabrics and microbenthic assemblages whose paleo-environmental distribution within the formation parallels the distribution of these elements through Proterozoic time. In the Society Cliffs Formation, restricted carbonates--including microdigitate stromatolites, laminated tufa, and tufted microbial mats--consist predominantly of synsedimentary cements; these facies and the cyanobacterial fossils they contain are common in Paleoproterozoic successions but rare in Neoproterozoic and younger rocks. Less restricted tidal-flat facies in the formation are composed of laminated microbialites dominated by micritic carbonate lithified early, yet demonstrably after compaction; these strata contain cyanobacteria that are characteristic in Neoproterozoic rocks. Within the formation, the facies-dependent distribution of microbial populations reflects both the style and timing of carbonate deposition because of the strong substrate specificity of benthic cyanobacteria. A reasonable conclusion is that secular changes in microbenthic assemblages through Proterozoic time reflect a decrease in the overall representation of rapidly lithified carbonate substrates in younger peritidal environments, as well as concomitant changes in the taphonomic window of silicification through which early life is observed.

Performance of Deep and Shallow Neural Networks, the Universal Approximation Theorem, Activity Cliffs, and QSAR.

PubMed

Winkler, David A; Le, Tu C

2017-01-01

Neural networks have generated valuable Quantitative Structure-Activity/Property Relationships (QSAR/QSPR) models for a wide variety of small molecules and materials properties. They have grown in sophistication and many of their initial problems have been overcome by modern mathematical techniques. QSAR studies have almost always used so-called "shallow" neural networks in which there is a single hidden layer between the input and output layers. Recently, a new and potentially paradigm-shifting type of neural network based on Deep Learning has appeared. Deep learning methods have generated impressive improvements in image and voice recognition, and are now being applied to QSAR and QSAR modelling. This paper describes the differences in approach between deep and shallow neural networks, compares their abilities to predict the properties of test sets for 15 large drug data sets (the kaggle set), discusses the results in terms of the Universal Approximation theorem for neural networks, and describes how DNN may ameliorate or remove troublesome "activity cliffs" in QSAR data sets. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rock cliffs hazard analysis based on remote geostructural surveys: The Campione del Garda case study (Lake Garda, Northern Italy)

NASA Astrophysics Data System (ADS)

Ferrero, A. M.; Migliazza, M.; Roncella, R.; Segalini, A.

2011-02-01

The town of Campione del Garda (located on the west coast of Lake Garda) and its access road have been historically subject to rockfall phenomena with risk for public security in several areas of the coast. This paper presents a study devoted to the determination of risk for coastal cliffs and the design of mitigation measures. Our study was based on statistical rockfall analysis performed with a commercial code and on stability analysis of rock slopes based on the key block method. Hazard from block kinematics and rock-slope failure are coupled by applying the Rockfall Hazard Assessment Procedure (RHAP). Because of the huge dimensions of the slope, its morphology and the geostructural survey were particularly complicated and demanding. For these reasons, noncontact measurement methods, based on aerial photogrammetry by helicopter, were adopted. A special software program, developed by the authors, was applied for discontinuity identification and for their orientation measurements. The potentially of aerial photogrammetic survey in rock mechanic application and its improvement in the rock mass knowledge is analysed in the article.

Rockfall triggering by cyclic thermal stressing of exfoliation fractures

USGS Publications Warehouse

Collins, Brian D.; Stock, Greg M.

2016-01-01

Exfoliation of rock deteriorates cliffs through the formation and subsequent opening of fractures, which in turn can lead to potentially hazardous rockfalls. Although a number of mechanisms are known to trigger rockfalls, many rockfalls occur during periods when likely triggers such as precipitation, seismic activity and freezing conditions are absent. It has been suggested that these enigmatic rockfalls may occur due to solar heating of rock surfaces, which can cause outward expansion. Here we use data from 3.5 years of field monitoring of an exfoliating granite cliff in Yosemite National Park in California, USA, to assess the magnitude and temporal pattern of thermally induced rock deformation. From a thermodynamic analysis, we find that daily, seasonal and annual temperature variations are sufficient to drive cyclic and cumulative opening of fractures. Application of fracture theory suggests that these changes can lead to further fracture propagation and the consequent detachment of rock. Our data indicate that the warmest times of the day and year are particularly conducive to triggering rockfalls, and that cyclic thermal forcing may enhance the efficacy of other, more typical rockfall triggers.

Extending Marketplace Tax Credits Would Make Coverage More Affordable for Middle-Income Adults.

PubMed

Liu, Jodi; Eiber, Christine

2017-07-01

ISSUE: Affordability of health coverage is a growing challenge for Americans facing rising premiums, deductibles, and copayments. The Affordable Care Act's tax credits make marketplace insurance more affordable for eligible lower-income individuals. However, individuals lose tax credits when their income exceeds 400 percent of the federal poverty level, creating a steep cliff. GOALS: To analyze the effects of extending eligibility for tax credits to individuals with incomes above 400 percent of the federal poverty level. METHODS: We used RAND's COMPARE microsimulation model to examine changes in insurance coverage and health care spending. KEY FINDINGS AND CONCLUSIONS: Extending tax-credit eligibility increases insurance enrollment by 1.2 million, at a total federal cost of $6.0 billion. Those who would benefit from the tax-credit extension are mostly middle-income adults ages 50 to 64. These new enrollees would be healthier than current enrollees their age, which would improve the risk pool and lower premiums. Eliminating the cliff at 400 percent of the federal poverty level is one policy option that may be considered to increase affordability of insurance.

Mazus sunhangii (Mazaceae), a New Species Discovered in Central China Appears to Be Highly Endangered

PubMed Central

Kim, Changkyun; Zhang, Jian-Wen; Zhang, Dai-Gui; Volis, Sergei

2016-01-01

Mazus sunhangii, a new species of Mazaceae from central China is described and illustrated based on evidence from morphology and molecular phylogeny. This new species is morphologically similar to M. puchellus and M. omeiensis but differs in erect habit, inflorescence position, leaf pattern and corolla color. Phylogenetic analysis based on four chloroplast DNA regions (rbcL, rps16, trnL-F, and psbA-trnH) identified the new species as the independent lineage sister to the other East Asian Mazus species. The new species is known only from a single location in Mt. Shennongjia area in northwest Hubei province, at the elevation of 760 m. The species grows on the limestone cliff, and, because a tourist arterial highway is located along this cliff, its habitat can be easily disturbed or destroyed. We propose that the only known species location is recognized as critical habitat (i.e., as the habitat required to ensure the persistence of a species) and the species listed as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a. PMID:27783628

Stability of Molasse: TLS for structural analysis in the valley of Gotteron-Fribourg, Switzerland

NASA Astrophysics Data System (ADS)

Ben Hammouda, Mariam; Jaboyedoff, Michel; Derron, Marc Henri; Bouaziz, Samir; Mazotti, Benoit

2016-04-01

The marine molasses of Fribourg (Switzerland) is an area where the cliff collapses and rockfalls are quite frequent and difficult to predict due to this particular lithology, a poorly consolidated greywacke. Because of some recent rockfall events, the situation became critical especially in the valley of Gotteron where a big block has slightly moved down and might destroy a house in case of rupture. The cliff made of jointed sandstone and thin layers of clay and siltstone presents many fractures, joints and massive cross bedding surfaces which increases the possibility of slab failure. This paper presents a detailed structural analysis of the cliff and the identification of the potential failure mechanisms. The methodology is about combining field observation and terrestrial LiDAR scanning point cloud in order to assess the stability of potential slope instabilities of molasses. Three LiDAR scans were done i) to extract discontinuity families depending to the dip and the dip direction of joints and ii) to run kinematic tests in order to identify responsible sets for each potential failure mechanisms. Raw point clouds were processed using IMAlign module of Polyworks and CloudCompare software. The structural analysis based on COLTOP 3D (Jaboyedoff et al. 2007) allowed the identification of four discontinuity sets that were not measured in the field. Two different failure mechanisms have been identified as critical: i) planar sliding which is the main responsible mechanism of the present fallen block and ii) wedge sliding. The planar sliding is defined by the discontinuity sets J1 and J5 with a direction parallel to the slope and with a steep dip angle. The wedges, defined by couples of discontinuity sets, contribute to increase cracks' opening and to the detachment of slabs. The use of TLS combined with field survey provides us a first interpretation of instabilities and a very promising structural analysis.

Inaccessible Biodiversity on Limestone Cliffs: Aster tianmenshanensis (Asteraceae), a New Critically Endangered Species from China.

PubMed

Zhang, Guo-Jin; Hu, Hai-Hua; Zhang, Cai-Fei; Tian, Xiao-Juan; Peng, Hui; Gao, Tian-Gang

2015-01-01

Aster tianmenshanensis G. J. Zhang & T. G. Gao, a new species of Asteraceae from southern China is described and illustrated based on evidence from morphology, micromorphology and molecular phylogeny. The new species is superficially similar to Aster salwinensis Onno in having rosettes of spatulate leaves and a solitary, terminal capitulum, but it differs by its glabrous leaf margins, unequal disc floret lobes and 1-seriate pappus. The molecular phylogenetic analysis, based on nuclear sequences ITS, ETS and chloroplast sequence trnL-F, showed that the new species was nested within the genus Aster and formed a well supported clade with Aster verticillatus (Reinw.) Brouillet et al. The new species differs from the latter in having unbranched stems, much larger capitula, unequal disc floret lobes, beakless achenes and persistent pappus. In particular, A. tianmenshanensis has very short stigmatic lines, only ca. 0.18 mm long and less than 1/3 of the length of sterile style tip appendages, remarkably different from its congeners. This type of stigmatic line, as far as we know, has not been found in any other species of Aster. The very short stigmatic lines plus the unequal disc floret lobes imply that the new species may have a very specialized pollination system, which may be a consequence of habitat specialization. The new species grows only on the limestone cliffs of Mt. Tianmen, Hunan Province, at the elevation of 1400 m. It could only be accessed when a plank walkway was built across the cliffs for tourists. As it is known only from an area estimated at less than 10 km2 and a walkway passes through this location, its habitat could be easily disturbed. This species should best be treated as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.

Environmental filtering drives the shape and breadth of the seed germination niche in coastal plant communities

PubMed Central

Pérez-Arcoiza, Adrián; Prieto, José Alberto; Díaz, Tomás E.

2017-01-01

Abstract Background and Aims A phylogenetic comparative analysis of the seed germination niche was conducted in coastal plant communities of western Europe. Two hypotheses were tested, that (1) the germination niche shape (i.e. the preference for a set of germination cues as opposed to another) would differ between beaches and cliffs to prevent seedling emergence in the less favourable season (winter and summer, respectively); and (2) the germination niche breadth (i.e. the amplitude of germination cues) would be narrower in the seawards communities, where environmental filtering is stronger. Methods Seeds of 30 specialist species of coastal plant communities were collected in natural populations of northern Spain. Their germination was measured in six laboratory treatments based on field temperatures. Germination niche shape was estimated as the best germination temperature. Germination niche breadth was calculated using Pielou’s evenness index. Differences between plant communities in their germination niche shape and breadth were tested using phylogenetic generalized least squares regression (PGLS). Key Results Germination niche shape differed between communities, being warm-cued in beaches (best germination temperature = 20 °C) and cold-cued in cliffs (14 °C). Germination niche was narrowest in seawards beaches (Pielou’s index = 0·89) and broadest in landwards beaches (0·99). Cliffs had an intermediate germination niche breadth (0·95). The relationship between niche and plant community had a positive phylogenetic signal for shape (Pagel’s λ = 0·64) and a negative one for breadth (Pagel’s λ = −1·71). Conclusion Environmental filters shape the germination niche to prevent emergence in the season of highest threat for seedling establishment. The germination niche breadth is narrower in the communities with stronger environmental filters, but only in beaches. This study provides empirical support to a community-level generalization of the hypotheses about the environmental drivers of the germination niche. It highlights the role of germination traits in community assembly. PMID:28334139

Sand sources and transport pathways for the San Francisco Bay coastal system, based on X-ray diffraction mineralogy

USGS Publications Warehouse

Hein, James R.; Mizell, Kira; Barnard, Patrick L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

The mineralogical compositions of 119 samples collected from throughout the San Francisco Bay coastal system, including bayfloor and seafloor, area beaches, cliff outcrops, and major drainages, were determined using X-ray diffraction (XRD). Comparison of the mineral concentrations and application of statistical cluster analysis of XRD spectra allowed for the determination of provenances and transport pathways. The use of XRD mineral identifications provides semi-quantitative compositions needed for comparisons of beach and offshore sands with potential cliff and river sources, but the innovative cluster analysis of XRD diffraction spectra provides a unique visualization of how groups of samples within the San Francisco Bay coastal system are related so that sand-sized sediment transport pathways can be inferred. The main vector for sediment transport as defined by the XRD analysis is from San Francisco Bay to the outer coast, where the sand then accumulates on the ebb tidal delta and also moves alongshore. This mineralogical link defines a critical pathway because large volumes of sediment have been removed from the Bay over the last century via channel dredging, aggregate mining, and borrow pit mining, with comparable volumes of erosion from the ebb tidal delta over the same period, in addition to high rates of shoreline retreat along the adjacent, open-coast beaches. Therefore, while previously only a temporal relationship was established, the transport pathway defined by mineralogical and geochemical tracers support the link between anthropogenic activities in the Bay and widespread erosion outside the Bay. The XRD results also establish the regional and local importance of sediment derived from cliff erosion, as well as both proximal and distal fluvial sources. This research is an important contribution to a broader provenance study aimed at identifying the driving forces for widespread geomorphic change in a heavily urbanized coastal-estuarine system.

An open source GIS-based tool to integrate the fragmentation mechanism in rockfall propagation

NASA Astrophysics Data System (ADS)

Matas, Gerard; Lantada, Nieves; Gili, Josep A.; Corominas, Jordi

2015-04-01

Rockfalls are frequent instability processes in road cuts, open pit mines and quarries, steep slopes and cliffs. Even though the stability of rock slopes can be determined using analytical approaches, the assessment of large rock cliffs require simplifying assumptions due to the difficulty of working with a large amount of joints, the scattering of both the orientations and strength parameters. The attitude and persistency of joints within the rock mass define the size of kinematically unstable rock volumes. Furthermore the rock block will eventually split in several fragments during its propagation downhill due its impact with the ground surface. Knowledge of the size, energy, trajectory… of each block resulting from fragmentation is critical in determining the vulnerability of buildings and protection structures. The objective of this contribution is to present a simple and open source tool to simulate the fragmentation mechanism in rockfall propagation models and in the calculation of impact energies. This tool includes common modes of motion for falling boulders based on the previous literature. The final tool is being implemented in a GIS (Geographic Information Systems) using open source Python programming. The tool under development will be simple, modular, compatible with any GIS environment, open source, able to model rockfalls phenomena correctly. It could be used in any area susceptible to rockfalls with a previous adjustment of the parameters. After the adjustment of the model parameters to a given area, a simulation could be performed to obtain maps of kinetic energy, frequency, stopping density and passing heights. This GIS-based tool and the analysis of the fragmentation laws using data collected from recent rockfall have being developed within the RockRisk Project (2014-2016). This project is funded by the Spanish Ministerio de Economía y Competitividad and entitled "Rockfalls in cliffs: risk quantification and its prevention"(BIA2013-42582-P).

Why come back home? Breeding-site fidelity varies with group size and parasite load in a colonial bird.

PubMed

Brown, Charles R; Roche, Erin A; Brown, Mary Bomberger

2017-10-01

Fidelity to a past breeding site is widespread among animals and may confer both costs and benefits. Colonial species occur at specific sites that can accommodate multiple breeders, and the choice of whether to return to last year's site or disperse elsewhere can affect colony site use, the colony size distribution and individual fitness. For the colonial cliff swallow, Petrochelidon pyrrhonota , which occupies colonies of widely different sizes, we used a 30-year field study in western Nebraska to investigate how the extent of infestation by ectoparasites and colony size affected breeders' colony site fidelity between years. We compared philopatry at colonies where parasitic swallow bugs, Oeciacus vicarius , had been removed by fumigation with that at nonfumigated sites exposed to natural levels of ectoparasites. About 25% of birds at nonfumigated colonies returned to their previous year's site, whereas about 69% of birds at fumigated colonies did so. Site fidelity was greatest at nonfumigated sites that changed the least in size between years. Birds were less likely to return to a nonfumigated site as the colony there became increasingly larger. Individuals philopatric to both nonfumigated and fumigated sites resided in colonies more similar in size between years than did dispersing birds. Most cliff swallows settled within 6 km of their previous year's site, indicating that many nonphilopatric birds still may have had some familiarity with the local landscape surrounding the site to which they moved. Removal of ectoparasites at a site allows large colonies to persist there perennially, probably contributing to higher philopatry because such large colonies are rare and would have been difficult to find had the residents dispersed. Cliff swallows are likely to be sensitive to both colony size and general familiarity with a given site or landscape region, and probably integrate these with other cues to select breeding colonies.

Paleoseismic and Paleogeographic Reconstruction of the Central Coastal of Ecuador: Insights from Quaternary Geological Data for the Jaramijó bay area

NASA Astrophysics Data System (ADS)

Chunga, K.; Maurizio, M.; Garces, D.; Quiñonez, M. F.; Peña, G. E.

2015-12-01

Late Holocene sequences of loose to weakly consolidated sand and clay sediments intercalated with volcanic-ash layers (particles transported by fall-out), are outcrops on a sea cliff in the Jaramijó bay area (situated 7 km away in the East direction from Manta city, Manabí, at the middle section of Ecuador's Pacific coastline). The main geomorphologic feature in the site is the wave-cut beach platform permanently exposed at the lowest tides and an 18 m-high coastal cliff retreat with an estimated rate of ca. 2.5 meter/year (Chunga, 2014). One of the most remarkable geoarchaeological evidences found in this outcrop, it is the remains of two large bones (ie., radius and radial) of the human forearm of ca. 800 years ago (with archaeological vestiges of the Manteña culture) covered by a 8 to 25 cm-thick volcanic ash layer, stratigraphically at the top, an erosive contact with chaotic deposition of medium to fine-grained sand which indicates a potential tsunami deposit. Moreover, several volcanic ash and lahar layers are well distinguished on the sea cliff, which are associated with pyroclastic products transported as lahars from the Quilotoa and Cotopaxi, Pululahua volcanic structures (northern Andes in Ecuador) situated at a distance between of 150-190 kilometers (Mothes and Hall, 2008; Usselman, 2006). It is not excluded that previous pre-Columbian cultures also have been displaced in the last 2,000 years by disastrous geological events such as subduction earthquakes, local tsunami and volcanic lahar-ash deposits. All of these stratigraphic and palaeoseismologic features will allow us to understand the catastrophic geological events that abruptly shaped the landscape, furthermore, to investigate the changes of moderate to high Late Holocene progradation rates of the Jaramijó bay coastline.

Detecting Slow Deformation Signals Preceding Dynamic Failure: A New Strategy For The Mitigation Of Natural Hazards (SAFER)

NASA Astrophysics Data System (ADS)

Vinciguerra, S.; Colombero, C.; Comina, C.; Umili, G.

2015-12-01

Rock slope monitoring is a major aim in territorial risk assessment and mitigation. The use of "site specific" microseismic monitoring systems can allow to detect pre-failure signals in unstable sectors within the rock mass and to predict the possible acceleration to the failure. To this aim multi-scale geophysical methods can provide a unique tool for an high-resolution imaging of the internal structure of the rock mass and constraints on the physical state of the medium. We present here a cross-hole seismic tomography survey coupled with laboratory ultrasonic velocity measurements and determination of physical properties on rock samples to characterize the damaged and potentially unstable granitic cliff of Madonna del Sasso (NW, Italy). Results allowed to achieve two main advances, in terms of obtaining: i) a lithological interpretation of the velocity field obtained at the site, ii) a systematic correlation of the measured velocities with physical properties (density and porosity) and macroscopic features of the granite (weathering and anisotropy) of the cliff. A microseismic monitoring system developed by the University of Turin/Compagnia San Paolo, consisting of a network of 4 triaxial geophones (4.5 Hz) connected to a 12-channel data logger, has been deployed on the unstable granitic cliff. More than 2000 events with different waveforms, duration and frequency content were recorded between November 2013 and July 2014. By inspecting the acquired events we identified the key parameters for a reliable distinction among the nature of each signal, i.e. the signal shape (in terms of amplitude, duration, kurtosis) and the frequency content (maximum frequency content and frequency distribution). Four main classes of recorded signals can be recognised: microseismic events, regional earthquakes, electrical noises and calibration signals, and unclassified events (probably grouping rockfalls, quarry blasts, other anthropic and natural sources of seismic noise).

Inaccessible Biodiversity on Limestone Cliffs: Aster tianmenshanensis (Asteraceae), a New Critically Endangered Species from China

PubMed Central

Tian, Xiao-Juan; Peng, Hui; Gao, Tian-Gang

2015-01-01

Aster tianmenshanensis G. J. Zhang & T. G. Gao, a new species of Asteraceae from southern China is described and illustrated based on evidence from morphology, micromorphology and molecular phylogeny. The new species is superficially similar to Aster salwinensis Onno in having rosettes of spatulate leaves and a solitary, terminal capitulum, but it differs by its glabrous leaf margins, unequal disc floret lobes and 1-seriate pappus. The molecular phylogenetic analysis, based on nuclear sequences ITS, ETS and chloroplast sequence trnL-F, showed that the new species was nested within the genus Aster and formed a well supported clade with Aster verticillatus (Reinw.) Brouillet et al. The new species differs from the latter in having unbranched stems, much larger capitula, unequal disc floret lobes, beakless achenes and persistent pappus. In particular, A. tianmenshanensis has very short stigmatic lines, only ca. 0.18 mm long and less than 1/3 of the length of sterile style tip appendages, remarkably different from its congeners. This type of stigmatic line, as far as we know, has not been found in any other species of Aster. The very short stigmatic lines plus the unequal disc floret lobes imply that the new species may have a very specialized pollination system, which may be a consequence of habitat specialization. The new species grows only on the limestone cliffs of Mt. Tianmen, Hunan Province, at the elevation of 1400 m. It could only be accessed when a plank walkway was built across the cliffs for tourists. As it is known only from an area estimated at less than 10 km2 and a walkway passes through this location, its habitat could be easily disturbed. This species should best be treated as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a. PMID:26308863

Hazards in the coastal karst of Balai (NW Sardinia, Italy)

NASA Astrophysics Data System (ADS)

Sanna, Laura; Uda, Michele; Pascucci, Vincenzo

2016-04-01

The coastal karst area of Balai headland is located in the central part of the Gulf of Asinara (North-West Sardinia, Italy) near the city of Porto Torres, comprised between the homonymous harbour and Platamona beach. This karst plateau has a monocline geometry truncated by the coastal escarpment, up to 40 m-high, that in the last decades has been affected by slope instability related to human activities and/or climate change. The area is characterised by a flat morphology constituted of Miocene limestone gently dipping towards the North-West. Its altitude ranges from 0 to 50 m asl. The 3 km-long cliff is locally interrupted by some small gravelly coves. Along the longitudinal profile of the headland, three main morphological steps have been identified at 15, 8 and 6.5 m asl. They represent past wave cut platforms. The shoreline is well marked and the coves cut into the land up to 50 m in length, perpendicularly to the coast. They follow the direction of a series of parallel NE-facing fractures. The modern tidal notch is well exposed along the carbonate cliff at the present sea level. Along the limestone cliff, notch development is amplified by mixing of sea and fresh water coming from submerged springs. Moreover, this marine erosion feature is a good sea level marker in microtidal conditions, such as Mediterranean Sea, and an indicator of tectonic stability, of the Sardinian microplate. In some coves, two generations of fossil notches have been observed at 6.5 m asl and -1 m bsl, respectively, along with lithophaga boreholes up to 8 m asl. Both indicate the past eustatic conditions. All these geomorphic features make Balai promontory an interesting geological spot for studying past sea level fluctuations and present slope movements, trying to distinguish hazards due to climate change from those directly related to anthropogenic forces such as wave-induced damage due to waterborne navigation.

Geologic map of the Glen Canyon Dam 30’ x 60’ quadrangle, Coconino County, northern Arizona

USGS Publications Warehouse

Billingsley, George H.; Priest, Susan S.

2013-01-01

The Glen Canyon Dam 30’ x 60’ quadrangle is characterized by nearly flat lying to gently dipping Paleozoic and Mesozoic sedimentary strata that overlie tilted Proterozoic strata or metasedimentary and igneous rocks similar to those exposed at the bottom of Grand Canyon southwest of the quadrangle. Mississippian to Permian rocks are exposed in the walls of Marble Canyon; Permian strata and minor outcrops of Triassic strata form the surface bedrock of House Rock Valley and Marble Plateau, southwestern quarter of the quadrangle. The Paleozoic strata exposed in Marble Canyon and Grand Canyon south of the map are likely present in the subsurface of the entire quadrangle but with unknown facies and thickness changes. The Mesozoic sedimentary rocks exposed along the Vermilion and Echo Cliffs once covered the entire quadrangle, but Cenozoic erosion has removed most of these rocks from House Rock Valley and Marble Plateau areas. Mesozoic strata remain over much of the northern and eastern portions of the quadrangle where resistant Jurassic sandstone units form prominent cliffs, escarpments, mesas, buttes, and much of the surface bedrock of the Paria, Kaibito, and Rainbow Plateaus. Jurassic rocks in the northeastern part of quadrangle are cut by a sub-Cretaceous regional unconformity that bevels the Entrada Sandstone and Morrison Formation from Cummings Mesa southward to White Mesa near Kaibito. Quaternary deposits, mainly eolian, mantle much of the Paria, Kaibito, and Rainbow Plateaus in the northern and northeastern portion of the quadrangle. Alluvial deposits are widely distributed over parts of House Rock Valley and Marble Plateau in the southwest quarter of the quadrangle. The east-dipping strata of the Echo Cliffs Monocline forms a general north-south structural boundary through the central part of the quadrangle, separating Marble and Paria Plateaus west of the monocline from the Kaibito Plateau east of the monocline. The Echo Cliffs Monocline continues north of the quadrangle into southern Utah. The gentle north- and northeast-dipping Mesozoic strata on the Kaibito and Rainbow Plateaus are partly interrupted by northwest-trending, broad-based, ill-defined synclines and anticlines. These broad-based structures form mesas and buttes near anticlinal crests and deeply incised drainages in synclinal valleys. The 1,300-ft-thick (396-m-thick) Navajo Sandstone erodes into a maze of tributary slot canyons in the northeastern part of the quadrangle. Mesozoic strata in the extreme northeast corner of the quadrangle dip gently southwest due to the influence of the Monument Upwarp in southeastern Utah and by an intrusive uplift (laccolith) that forms Navajo Mountain, a prominent 10,388 ft (3,166 m) landmark just northeast of the quadrangle.

Long-term rocky coast erosion: the influence of structural pattern and lithological context, as evidenced in the chalk (NW Normandy) and granitic (SW Brittany) rocks, NW France

NASA Astrophysics Data System (ADS)

Duperret, Anne; Raimbault, Céline; Duguet, Timothée; Le Gall, Bernard; Costa, Stéphane; Vandycke, Sara

2017-04-01

During the EC2CO/DRIL/CROCODYL project, high-resolution land-sea DEM have been produced in NW Normandy and SW Brittany rocky coastal zone, using high-resolution bathymetry from shallow-water cruises CROCOLIT-1,-2,-3 (Duperret, 2013), SPLASHALIOT-3 (Maillet, 2014), THAPENFROM-1 (Duperret, 2015) and aerial topographic LiDAR data from the Litto3D project. Two study sites were selected to map detailed geomorphology of shore platforms in order to better understand rock coast evolution processes through time and long-term rates of rocky coastal erosion versus geological context. The eastern English Channel is made of coastal chalk cliffs that currently eroding with fast mean rates of the order of a few dm/year. In Normandy coast (NW France), this results to the generation of roughly linear coastal segments of about 20-30km long each. On coastal segments only made of Upper Cretaceous Chalk, erosion occurs by present-day sudden and repeated vertical failures and cliff collapses. Cliff collapse process is shaping vertical chalk cliffs in association with resulting roughly flat shore platforms. Even if shore platforms width are short and homogeneous (a few hundred meters in width), the detailed morphology observed on high-resolution bathymetry evidenced two main submarine geomorphological types. One is linear and regular and associated with linear coastal sections. This corresponds to homogeneous Chalk Formation and the lack of large-scale tectonic features. Coastal sections with chalk lithology variations, local folding, large-scale fractures transverse-oriented to the coastline and onshore valleys incision evidence chaotic shore platforms morphologies. They conduct to variations in coastline orientation and to meter-scale shoreline indentations The southwestern part of Brittany is made of low-lying granitic headland and indented bay cut into meta/granitic rocks. Erosion rates are poorly known, due to slow coastal evolutions through contemporary times. Land-Sea DEM evidence similar onshore and offshore morphologies, with flat and wide superposed plains, limited each one by 10m high scarps. In this case, shore platform extension reaches a few km in width and appears as superposed paleo-shore platforms generated since Pleistocene (Raimbault et al, in press). The erosive process is thus link to a long-term alteration of granitic rocks since Cenozoic, mainly clear and etched during recent past high sea levels. Coastal areas with large bays appear locally to be guided by large-scale Cenozoic fractures. In some places, km-scale fractures favor a spatial concentration of erosion. They are shaping coastline orientation and shore platform ending at km-scale.

75. Photocopy of photograph (original print in the Minnesota Historical ...

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

75. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, ca. 1870s. #22006. Photographer: Illingworth.) VIEW TO SOUTHEAST, SHOWING THE UPPER LEVEE AND BLUSS (on left) TO WHICH THE HIGH BRIDGE WAS BUILT - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

Clifford Malcolm: Glimpses of His South African Legacy of Hope

ERIC Educational Resources Information Center

Govender, Nadaraj; Ramsuran, Anitha; Dhunpath, Rubby

2008-01-01

This article reviews the contributions of Cliff Malcolm while in South Africa during the period 1997-2005. It focuses on his contribution to the fields of science education, teacher education, learner-centered education, transformational outcomes-based education and HIV/AIDS education. In this paper we provide snapshots of his work as an academic,…

Do Modes of Thinking Predict Career Interest Types among Chinese University Students?

ERIC Educational Resources Information Center

Zhang, Li-fang; Fan, Weiqiao

2007-01-01

This study had two objectives. The preliminary objective was to further test the psychometric properties of the short-version self-directed search that was intended to be a brief research tool for measuring Holland [Holland, J. L. (1973). "Making vocational choices: A theory of careers." Englewood Cliffs, NJ: Prentice-Hall; Holland, J.…

Underrepresentation of Females in the Superintendency in Minnesota

ERIC Educational Resources Information Center

Wyland, Catherine

2016-01-01

Public school district leadership is dominated by males while teaching is dominated by females (Blount, 1998; Glass, Björk, & Brunner, 2000; Grogan, 1996). Some may not recognize this as a problem while others might refer to this underrepresentation as a glass ceiling, a sticky floor, a concrete wall, or a glass cliff. In any case, the…

Unmanned Air Vehicle/Remotely Piloted Vehicle Analysis for Lethal UAV/ RPV

DTIC Science & Technology

1993-09-01

taking the output power at a relatively low speed from the camshaft which is gear-driven at half the crankshaft RPM [Ref. 6]. there engine is a four...from the top of a tree , from over a steep cliff, or other perilous terrain. In addition, parachute landings invariably take their toll in vehicle damage

Department of Defense August 2003 Influencer Poll 1 Overview Report

DTIC Science & Technology

2004-03-01

more positive change in 4 Ajzen , I . & Fishbein , M . (1980). Understanding Attitudes and Predicting...Social Behavior. Englewood Cliffs, NJ: Prentice-Hall. 5 Fishbein , M . & Ajzen , I . (1975). Belief, Attitude, Intention and Behavior: An Introduction to...Mavor, editors. Division of Behavioral and Social Sciences and Education. Washington, DC: The National Academies Press. 12 Fishbein , M ., Ajzen , I

Two cases of contact dermatitis resulting from use of body wash as a skin moisturizer.

PubMed

Miller, Michael A; Borys, Doug; Riggins, Michele; Masneri, David C; Levsky, Marc E

2008-02-01

The use of liquid skin cleanser or body wash has become common in the United States. We report 2 cases of contact dermatitis secondary to the application of Dove Body Wash (Unilever US, Inc., Englewood Cliffs, NJ) with the consumer misconception that the product was a skin moisturizing cream.

Managing Supply Chain Disruptions

DTIC Science & Technology

2008-08-09

to be negatively associated with innovativeness (Hage & Aiken, 1969; Moch & Morse, 1977; Rogers, 1995; Russell & Hoag, 2004). The range of new...processes, or innovations ( Moch & Morse, 1977). Grover (1993) adds that decreased autonomy of organizational components and the bounded perspective of...Structuring of Organizations: A Synthesis of the Research. Englewood Cliffs, N.J.: Prentice-Hall. Moch , M. K. & Morse, E. V. (1977). Size

Peaks, Cliffs and Valleys: The Peculiar Incentives of Teacher Pensions

ERIC Educational Resources Information Center

Costrell, Robert M.; Podgursky, Michael

2008-01-01

Pensions have long been an important part of compensation for teachers in public schools. However, the incentive structures of teacher pension systems are not widely understood, even though they can have powerful effects on the composition of the teaching force and on public finance. In their research, the authors have found that teacher pension…

75 FR 1802 - Termination of the Environmental Impact Statement for the General Management Plan, Gila Cliff...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-13

... Management Plan because it has determined that an Environmental Assessment (EA) is the more appropriate... Assessment was approved by the Chief of the NPS Environmental Quality Division on November 4, 2009. The draft general management plan and Environmental Assessment is expected to be distributed for a 30 day public...

76 FR 81992 - PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-29

... License Application for Bell Bend Nuclear Power Plant; Exemption 1.0 Background PPL Bell Bend, LLC... for Nuclear Power Plants.'' This reactor is to be identified as Bell Bend Nuclear Power Plant (BBNPP... based upon the U.S. EPR reference COL (RCOL) application for UniStar's Calvert Cliffs Nuclear Power...

76 FR 30584 - Safety Zones; Eleventh Coast Guard District Annual Fireworks Events

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-26

.... 2. LA County Dept of Beach and Harbors 4th of July Fireworks Sponsor Los Angeles, CA County Dept of... waters of the Sea Cliff State Beach Pier. 27. Rio Vista Bass Derby Fireworks Sponsor Rio Vista Chamber of... Vista, CA waterfront. Regulated Area 100-foot radius around the fireworks launch barge during the...

Saving Whales and Dolphins through Petroglyphs and Activist Artworks

ERIC Educational Resources Information Center

Bae, Jaehan

2013-01-01

Whaling emerged in ancient times, when whales served as a source of food, fuel, and other everyday resources that were vital for human civilizations. Prehistoric images of whales are found on rocks in a few areas throughout the world, most notably the famous petroglyphs at the Bangudae cliffs in Ulsan, South Korea, which depict whales and other…

Golden Peaks and Perilous Cliffs: Rethinking Ohio's Teacher Pension System

ERIC Educational Resources Information Center

Costrell, Robert M.; Podgursky, Michael

2007-01-01

In response to a journalist inquiry regarding research on funding of Ohio's teacher retirement system and its effect on school district finances, this analysis by the Thomas B. Fordham Institute points to serious questions and profound concerns about the health of Ohio's teacher pension system, and that similar time bombs may be ticking in other…

75 FR 4369 - Combined Notice of Filings. #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-27

...; ER04-485-016; ER07-244-010; ER07-245-010; ER07-247-010. Applicants: R.E. Ginna Nuclear Power Plant, LLC..., LLC, Constellation Energy Commodities Group M, Calvert Cliffs Nuclear Power Plant LLC, Raven One, LLC..., Foote Creek IV, LLC, Ridge Crest Wind Partners, LLC, Oak Creek Wind Power, LLC, Foote Creek III, LLC...

Constructing bald eagle nests with natural materials

Treesearch

T. G. Grubb

1995-01-01

A technique for using natural materials to build artificial nests for bald eagles (Haliaeetus leucocephalus) and other raptors is detailed. Properly constructed nests are as permanently secured to the nest tree or cliff substrate as any eagle-built nest or human-made platform. Construction normally requires about three hours and at least two people. This technique is...

What if We Made Fewer Ph.D.'s?

ERIC Educational Resources Information Center

Cassuto, Leonard

2012-01-01

Whenever a discussion opens about nonacademic employment for Ph.D.s, it is not long before someone suggests reducing graduate-school admissions. "The market for full-time scholars has fallen off a cliff lately," this argument goes, "so why not just train fewer of them?" The strategy to reduce the number of Ph.D. students recurs in those…

Quality of ground water from private domestic wells

USGS Publications Warehouse

DeSimone, Leslie A.; Hamilton, Pixie A.; Gilliom, Robert J.

2009-01-01

This article highlights major findings from two USGS reports: DeSimone (2009) and DeSimone and others (2009). These reports can be accessed at http://water.usgs.gov/nawqa. This article is followed by a summary of treatment considerations and options for owners of private domestic wells, written by Cliff Treyens of the National Ground Water Association.

75 FR 25876 - Notice of Intent To Prepare Resource Management Plans for the Beaver Dam Wash and Red Cliffs...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-10

... personnel; Federal, state, and local agencies; and other stakeholders. The issues include: Air quality... of the Sand Mountain Special Recreation Management Area will remain Open under all alternatives of the plan amendment, consistent with the agreement for joint management by the State of Utah's Sand...

Mineral resource potential map of the Vermilion Cliffs-Paria Canyon instant study area, Coconino County, Arizona, and Kane County, Utah

USGS Publications Warehouse

Bush, Alfred L.; Lane, Michael

1982-01-01

Water is perhaps the most significant resource needed in the study area. A number of perennial springs support the few local ranchers and tourist facilities. Some ground water would be available below the plateau, but drilling depths would be more than 2,000 ft (600-700 m).

A Prescriptive Model for Resource Allocation at the Intermediate Level Engine Facility.

DTIC Science & Technology

1981-06-01

opinion was to use a linear rela- tionship in the absence of any other method (4). This sug- gestion was based on his extensive knowledge in the area 21 of...Business Publica - tions, Inc., 1980. 16. Shannon, Robert E. Systems Simulation--the Art and Science. Englewood Cliffs NJ: Prentice Hall, Inc., 1975. 17

The effects of canopy openings and population size on the persistence of Southwest columbines at risk of extinction

Treesearch

Kelly G. Gallagher; Brook G. Milligan

2001-01-01

The habitat associated with riparian, understory, rare and endangered plant populations of the Southwest includes rocky places in high-altitude canyons, mostly along shady streams, pools, and dripping cliffs. The composition of these insular plant populations, which are separated by intervening desert, is influenced by several local environmental conditions. The...

The First Americans. A History of US. Book One.

ERIC Educational Resources Information Center

Hakim, Joy

This history book traces the experiences of Native Americans from the time of their arrival from Asia to the end of the 16th century. The book includes readings on such communities as the cliff dewllers of the west, the Plains Indians, and the Mound Builders. There also are details of the Native Americans' early contacts with such European…

3-D Surface Visualization of pH Titration "Topos": Equivalence Point Cliffs, Dilution Ramps, and Buffer Plateaus

ERIC Educational Resources Information Center

Smith, Garon C.; Hossain, Md Mainul; MacCarthy, Patrick

2014-01-01

3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

76 FR 16457 - Advisory Committee on Reactor Safeguards; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-23

... Thursday, October 21, 2010 (74 FR 65038-65039). Thursday, April 7, 2011, Conference Room T2-B1, 11545....: Selected Chapters of the Safety Evaluation Report (SER) with Open Items Associated with the Calvert Cliffs... pursuant to 5 U.S.C. 552b(c)(4).] Friday, April 8, 2011, Conference Room T2-B1, 11545 Rockville Pike...

Point of View--NCLB: Dreams and Nightmares

ERIC Educational Resources Information Center

Houston, Paul D.

2005-01-01

The idea of leaving no child behind may sound like a noble dream. But the federal law intended to fulfill that dream is in Houston's opinion so flawed that it has become a nightmare for educators. Sadly, the No Child Left Behind (NCLB) Act is a nightmare in which everyone is naked while being pushed off a cliff because of poor test performance.…

Rapid 3-D analysis of rockfalls

USGS Publications Warehouse

Stock, Greg M.; Guerin, A.; Avdievitch, Nikita N.; Collins, Brian D.; Jaboyedoff, Michel

2018-01-01

Recent fatal and damaging rockfalls in Yosemite National Park indicate the need for rapid response data collection methods to inform public safety and assist with management response. Here we show the use of multiple-platform remote sensing methods to rapidly capture pertinent data needed to inform management and the public following a several large rockfalls from El Capitan cliff in Yosemite Valley, California.

Glass Cliffs, Queen Bees, and the Snow-Woman Effect: Persistent Barriers to Women's Leadership in the Academy

ERIC Educational Resources Information Center

Pasquerella, Lynn; Clauss-Ehlers, Caroline S.

2017-01-01

By outlining some of the familiar and persistent barriers to women's leadership at the highest administrative levels within colleges and universities, the authors want to open a conversation about how to accelerate the type of change embodied by Ronald Takaki's notion of a "different mirror." Developing this notion, Takaki asks,…

Cost Reporting at a Navy Branch Clinic

DTIC Science & Technology

1993-03-01

John Wiley & Sons, 1991. 15 Horngren , Charles, Cost Accounting -=A Managerial Emphasis, 5th Edition, Prentice Hall, Inc., Englewood Cliffs, N.J., 1982...traditionally reported under a partial cost reporting system. By applying basic principles of managerial accounting , a full cost reporting system is...traditionally reported under a partial cost reporting system. By applying basic principles of managerial accounting , a proposed full cost reporting

The Graduation Cliff: Improving the Post-School Outcomes of Students with Disabilities

ERIC Educational Resources Information Center

McFadden, Erica Skogebo; Daugherty, David B.; Lee, Sang Eun; Fisher, Kim W.; Hack, Anthony

2015-01-01

There is a federal movement to improve student outcomes targeting some of these predictors in several recently launched initiatives, but where does Arizona stand? What are we currently doing to move the needle, and what do we still need to do? This report prepared for the Arizona Developmental Disabilities Planning Council has two objectives: (1)…

The Graduation Cliff: Improving the Post-School Outcomes of Students with Disabilities. Summary Report

ERIC Educational Resources Information Center

McFadden, Erica Skogebo; Daugherty, David B.; Lee, Sang Eun; Fisher, Kim W.; Hack, Anthony; Spyra, Ed

2015-01-01

There is a federal movement to improve student outcomes targeting some of these predictors in several recently launched initiatives, but where does Arizona stand? What are we currently doing to move the needle, and what do we still need to do? This report prepared for the Arizona Developmental Disabilities Planning Council has two objectives: (1)…

Juling Crater

NASA Image and Video Library

2018-03-14

This view from NASA's Dawn mission shows where ice has been detected in the northern wall of Ceres' Juling Crater, which is in almost permanent shadow. Dawn acquired the picture with its framing camera on Aug. 30, 2016, and it was processed with the help of NASA Ames Stereo Pipeline (ASP), to estimate the slope of the cliff. https://photojournal.jpl.nasa.gov/catalog/PIA21918

Wild 2 Features

NASA Image and Video Library

2004-06-17

These images taken by NASA's Stardust spacecraft highlight the diverse features that make up the surface of comet Wild 2, showing a variety of small pinnacles and mesas seen on the limb of the comet and the location of a 2-kilometer (1.2-mile) series of aligned scarps, or cliffs, that are best seen in the stereo images. http://photojournal.jpl.nasa.gov/catalog/PIA06284

77 FR 1748 - Atomic Safety and Licensing Board; Calvert Cliffs 3 Nuclear Project, LLC, and UniStar Nuclear...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-11

... observe this evidentiary hearing. However, all signs, banners, posters, demonstrations, and displays are... required by NRC policy, signs, banners, posters, and displays not larger than 18 x 18 will be permitted at..., banner, poster or display affixed to a stick, or similar device, will not be permitted at the oral...

Mineral resource potential map of the Pyramid Roadless Area, El Dorado County, Colorado

USGS Publications Warehouse

Armstrong, Augustus K.; Chaffee, Maurice A.; Scott, Douglas F.

1983-01-01

Studies show., there is low potential for small deposits of gold, silver, and base metals in the Pyramid Roadless Area. There are two uranium claims (Cliff Ridge mining claims) located within the roadless area, but samples from this site showed no uranium. There are no indications of geothermal resources, coal, oil, or gas.

Native plants and communities and exotic plants within the Hoosier-Shawnee ecological assessment area

Treesearch

Steven D. Olson; Michael A. Homoya; Elizabeth L. Shimp

2004-01-01

The diverse natural communities in the Hoosier-Shawnee Ecological Assessment Area include forests, barrens, cliffs, wetlands, and streams. Communities are described based on their dominant and characteristic canopy and understory species as well as abiotic factors. An assessment of the global and state status of plant species is presented; the viability of over 360...

5 CFR Appendix A to Subpart E of... - Schedule of Environmental Differentials Paid for Exposure to Various Degrees of Hazards, Physical...

Code of Federal Regulations, 2011 CFR

2011-01-01

.... 1, 1970. Examples —Working with, or in close proximity to operations involved in research, in... adequate (for example, working from a swinging stage, boatswain chair, a similar support); or (3) If... employees; such as the following: July 1, 1972. Examples: —Working on cliffs, narrow ledges, or steep...

Is Managing Academics "Women's Work"? Exploring the Glass Cliff in Higher Education Management

ERIC Educational Resources Information Center

Peterson, Helen

2016-01-01

Sweden is among the countries with the highest per cent of women university Vice Chancellors in Europe. In "She Figures 2012" the average proportion of female Vice Chancellors in the 27 European Union countries is estimated to be 10 per cent. In Sweden the number is much higher: 43 per cent. Swedish higher education management has…

Fuel-Cell Propulsion for Small Manned Submersibles.

DTIC Science & Technology

1979-05-12

6 Table of Figu--.. . .. . ..... ................... 7 Introduction ........... ...................... 8 Chapter I. Submersibles and...wooden hull, and although the vessel’s dimensions are not known, she was capable of carrying twelve people surviving on the "quint- essence of air...capacility with the submersibles Sea Cliff, Turtle, Trieste, and the nuclear-powered NR-l presently operational. ( 7 In the seventies, the U.S. Navy also

AGU Members Learn Ways to Get Involved in Science Policy

NASA Astrophysics Data System (ADS)

Uhlenbrock, Kristan

2013-01-01

Gasps filled the room as scientists listened to a talk about the looming U.S. "fiscal cliff" and sequestration impacts on the science community. This was but one example of efforts by AGU's Public Affairs team during this year's Fall Meeting to talk to members about the latest news on the federal budget and what was happening on Capitol Hill.

75 FR 60147 - Calvert Cliffs Nuclear Power Plant, LLC; Independent Spent Fuel Storage Installation; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-29

... NRC E-Filing rule, which the NRC promulgated on August 28, 2007 (72 FR 49139). All documents filed in... submission of a request for hearing or petition to intervene, must be filed in accordance with the E-Filing rule. The E-Filing rule requires participants to submit and serve all adjudicatory documents over the...

Examining the Structure of Vocational Interests in Turkey in the Context of the Personal Globe Model

ERIC Educational Resources Information Center

Vardarli, Bade; Özyürek, Ragip; Wilkins-Yel, Kerrie G.; Tracey, Terence J. G.

2017-01-01

The structural validity of the Personal Globe Inventory-Short (PGI-S: Tracey in J Vocat Behavi 76:1-15, 2010) was examined in a Turkish sample of high school and university students. The PGI-S measures eight basic interest scales, Holland's ("Making vocational choice," Prentice-Hall, Englewood Cliffs, 1997) six types, Prediger's ("J…

Services Supply Chain in the Department of Defense: A Comparison of Acquisition Management Practices in the Army, Navy, and Air Force

DTIC Science & Technology

2010-08-23

characteristics also lead to differences in the marketing of services ( Lovelock , 1992; Hutt & Speh, 1998). Given these differences in the production and...Press. Lovelock , C. H. (1992). Are services really different? In C. H. Lovelock (Ed.), Managing services (2nd ed., pp. 1-8). Englewood Cliffs, NJ

First records of two species of mammals in the Huachuca Mountains: results of ecological stewardship at Fort Huachuca

Treesearch

Ronnie Sidner; H. Sheridan Stone

2005-01-01

We report the first voucher of the cliff chipmunk (Neotamias dorsalis) and observations of Brazilian free-tailed bats (Tadarida brasiliensis) from the Huachuca Mountains, Arizona, where these species had not been documented. While presence of T. brasiliensis was expected on Fort Huachuca, N. dorsalis was a surprise after a century...

77 FR 46613 - Safety Zone; 2012 Ironman US Championship Swim, Hudson River, Fort Lee, NJ

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-06

... 1625-AA00 Safety Zone; 2012 Ironman US Championship Swim, Hudson River, Fort Lee, NJ AGENCY: Coast... navigable waters of the Hudson River in the vicinity of Englewood Cliffs and Fort Lee, NJ for the 2012... Championship Swim, Hudson River, Fort Lee, NJ in the Federal Register (77 FR 34285). We received no comments on...

Funding Survival Toolkit: 3 Fiscal Cliff Myths, Debunked

ERIC Educational Resources Information Center

House, Jenny

2013-01-01

In the face of annual budget deficits, sequestration means automatic, across-the-board spending cuts to all federal agencies. This drastic step allows Congress to limit the size of the budget and gives it the right to make mandatory cuts if the cost of running the government exceeds the cap. On March 1, we all watched as Congress was unable to…

Fine-Grained Rims in the Allan Hills 81002 and Lewis Cliff 90500 CM2 Meteorites: Their Origin and Modification

NASA Technical Reports Server (NTRS)

Hua, X.; Wang, J.; Buseck, P. R.

2002-01-01

Antarctic CM meteorites Allan Hills (ALH) 8 1002 and Lewis Cliff (LEW) 90500 contain abundant fine-grained rims (FGRs) that surround a variety of coarse-grained objects. FGRs from both meteorites have similar compositions and petrographic features, independent of their enclosed objects. The FGRs are chemically homogeneous at the 10 m scale for major and minor elements and at the 25 m scale for trace elements. They display accretionary features and contain large amounts of volatiles, presumably water. They are depleted in Ca, Mn, and S but enriched in P. All FGRs show a slightly fractionated rare earth element (REE) pattern, with enrichments of Gd and Yb and depletion of Er. Gd is twice as abundant as Er. Our results indicate that those FGRs are not genetically related to their enclosed cores. They were sampled from a reservoir of homogeneously mixed dust, prior to accretion to their parent body. The rim materials subsequently experienced aqueous alteration under identical conditions. Based on their mineral, textural, and especially chemical similarities, we conclude that ALH 8 1002 and LEW 90500 likely have a similar or identical source.

Think crisis-think female: the glass cliff and contextual variation in the think manager-think male stereotype.

PubMed

Ryan, Michelle K; Haslam, S Alexander; Hersby, Mette D; Bongiorno, Renata

2011-05-01

The "think manager-think male" (TMTM) association underlies many gender inequalities in the workplace. However, research into the "glass cliff" has demonstrated that the suitability of male and female managers varies as a function of company performance such that in times of poor performance people may "think female" (Ryan & Haslam, 2005, 2007). Three studies examined gender and managerial stereotypes in the context of companies that are doing well or doing badly. Study 1 reproduced TMTM associations for descriptions of managers of successful companies but demonstrated a reversal for managers of unsuccessful companies. Study 2 examined the prescriptive nature of these stereotypes. No TMTM relationship was found for ideal managers of successful companies, but ideal managers of unsuccessful companies were associated with the female stereotype. Study 3 suggested that women may be favored in times of poor performance, not because they are expected to improve the situation, but because they are seen to be good people managers and can take the blame for organizational failure. Together, the studies illustrate the importance of context as a moderator of the TMTM association. Practical and theoretical implications for gender discrimination in the workplace are discussed.

The Evolution of Empathy and Women's Precarious Leadership Appointments.

PubMed

Vongas, John G; Al Hajj, Raghid

2015-01-01

Glass cliffs describe situations in which women are promoted to executive roles in declining organizations. To explain them, some authors suggest that people tend to "think crisis-think female." However, the root cause of this association remains elusive. Using several subfields of evolutionary theory, we argue that biology and culture have shaped the perception of women as being more empathic than men and, consequently, as capable of quelling certain crises. Some crises are more intense than others and, whereas some brew within organizations, others originate from the external environment. We therefore propose that women will be selected to lead whenever a crisis is minimal to moderate and stems primarily from within the organization. Men, on the other hand, will be chosen as leaders whenever the crisis threatens the very existence of the firm and its source is an external threat. Leadership is a highly stressful experience, and even more so when leaders must scale glass cliffs. It is imperative that we understand what gives rise to them not only because they place women and potentially other minorities in positions where the likelihood of failure is high, but also because they help propagate stereotypes that undermine their true leadership ability.

Environmental, depositional and cultural changes in the upper Pleistocene and early Holocene; the Cinglera del Capello Sequence (Capellades, Spain)

USGS Publications Warehouse

Vaquero, Manuel; Allué, Ethel; Bischoff, James L.; Burjachs, Francesc; Vallverdú, Josep

2013-01-01

The correlation between environmental and cultural changes is one of the primary archeological and paleoanthropological research topics. Analysis of ice and marine cores has yielded a high-resolution record of millennial-scale changes during the Late Pleistocene and Holocene eras. However, cultural changes are documented in low-resolution continental deposits; thus, their correlation with the millennial-scale climatic sequence is often difficult. In this paper, we present a rare occurrence in which a thick archeological sequence is associated with a high-resolution environmental record. The Cinglera del Capello is a tufa-draped cliff located in the northeastern Iberian Peninsula, 50 km west of Barcelona. This cliff harbors several rock-shelters with Late Pleistocene and Early Holocene deposits. Together, the deposits of four rock-shelters span from 7000 to 70,000 years ago and provide a high-resolution record of the environmental and human dynamics during this timespan. This record allows the correlation of the cultural and environmental changes. The multiproxy approach to the Cinglera evidence indicates that the main cultural stages of the Late Pleistocene and Early Holocene (Middle Paleolithic, Upper Paleolithic and Mesolithic) are associated with significant changes in the environmental and depositional contexts.

The Evolution of Empathy and Women’s Precarious Leadership Appointments

PubMed Central

Vongas, John G.; Al Hajj, Raghid

2015-01-01

Glass cliffs describe situations in which women are promoted to executive roles in declining organizations. To explain them, some authors suggest that people tend to “think crisis-think female.” However, the root cause of this association remains elusive. Using several subfields of evolutionary theory, we argue that biology and culture have shaped the perception of women as being more empathic than men and, consequently, as capable of quelling certain crises. Some crises are more intense than others and, whereas some brew within organizations, others originate from the external environment. We therefore propose that women will be selected to lead whenever a crisis is minimal to moderate and stems primarily from within the organization. Men, on the other hand, will be chosen as leaders whenever the crisis threatens the very existence of the firm and its source is an external threat. Leadership is a highly stressful experience, and even more so when leaders must scale glass cliffs. It is imperative that we understand what gives rise to them not only because they place women and potentially other minorities in positions where the likelihood of failure is high, but also because they help propagate stereotypes that undermine their true leadership ability. PMID:26617564

Quantifying coastal erosion rates using anatomical change in exposed tree roots at Porquerolles Island (Var, France).

NASA Astrophysics Data System (ADS)

Morel, Pauline; Corona, Christophe; Lopez-Saez, Jérôme; Rovéra, Georges; Dewez, Thomas; Stoffel, Markus; Berger, Frédéric

2017-04-01

Rocky coasts are the most common type of ocean-land contacts and can be found in all types of morphogenetic environments. Most work on rocky environments focused on the impacts of modern sea level rise on cliff stability derived from sequential surveys, direct measurements or erosional features in anthropogenic structures. Studies mainly focused on rapid erosion so that little is known about erosion rates of the French Mediterranean coastal area. Using anatomical reactions in roots, has been successfully used in various environments in the past to quantify continuous denudation rates, mostly in relation with gullying processes (Vandekerckhove, 2001; Malik, 2008), aerial (or sheet) (Bodoque et al., 2005; Lopez Saez et al., 2011; Lucia et al., 2011), river bank (Malik, 2006; Hitz et al., 2008a; Stoffel et al., 2012), or lake shore (Fantucci, 2007) erosion, but never so far on coastal cliffs environment. This study aims at exploring the potential of dendrogeomorphic approach to quantify multidecadal changes in coastal environments on Porquerolles Island (Var, France). We sampled 56 discs from Pinus halepensis Mill. roots on former alluvial deposits eroded by present day sea level (escarpments of a few meter in height) and on sandy-gravelly cliffs. We were able to dates erosion pulses as well as changes in cliff geometry with annual resolution over 30-40 years showing an average erosion rate of 2.1 cm yr-1. Our results are consistent with those found in the study of Giuliano (2015) on Mediterranean coastal environment. This contribution therefore demonstrates that dendrogeomorphic analyses of roots clearly have significant potential and are a powerful tool for the quantification of multidecadal cliff retreats rates in areas where measurements of past erosion is lacking. References: Bodoque J, Díez-Herrero A, Martín-Duque J, Rubiales J, Godfrey A, Pedraza J, Carrasco R, Sanz M. 2005. Sheet erosion rates determined by using dendrogeomorphological analysis of exposed tree roots: Two examples from central Spain. Catena 64 : 81-102. Fantucci R. 2007. Dendrogeomorphological analysis of shore erosion along Bolsena lake (central Italy). Dendrochronologia 24 : 130-140. Giuliano J. Érosion des falaises de la région Provence-Alpes-Côte d'Azur : évolution et origine de la morphologie côtière en Méditerranée : télédétection, géochronologie, géomorphologie. Sciences de la Terre. Université Nice Sophia Antipolis, 2015. Français. . Hitz O, Gärtner H, Heinrich I, Monbaron M, 2008a. Application of ash (Fraxinus excelsior l.) roots to determine erosion rates in mountain torrents. Catena 72 : 248-258. Lopez Saez J, Corona C, Stoffel M, Rovéra G, Astrade L, Berger F. 2011. Mapping of erosion rates in marly badlands based on a coupling of anatomical changes in exposed roots with slope maps derived from LiDAR data. Earth Surface Processes and Landforms 36 : 1162-1171. Lucía, A., Laronne, J. B., & Martín-Duque, J. F. (2011). Geodynamic processes on sandy slope gullies in central Spain field observations, methods and measurements in a singular system. Geodinámica acta, 24(2), 61-79. Malik I. 2008. Dating of small gully formation and establishing erosion rates in old gullies under forest by means of anatomical changes in exposed tree roots (Southern Poland). Geomorphology 93 : 421-436.
 Malik I. 2006. Gully erosion dating by means of anatomical changes in exposed roots (Proboszczowicka plateau, Southern Poland). Geochronometria 25 : 57-66. Stoffel M, Casteller A, Luckman B H, Villalba R, 2012. Spatiotemporal analysis of channel wall erosion in ephemeral torrents using tree roots - An example from the Patagonian Andes. Geology40 : 247-250. Vandekerckhove L. 2001. Short-term bank gully retreat rates in Mediterranean environments. Catena 44 : 133-161.