Science.gov

Sample records for monitoring rock fall

  1. Feasibility of Monitoring Rock Fall in Yosemite Valley using Seismic Methods

    SciTech Connect

    Myers, S; Rock, D; Mayeda, K

    2000-03-02

    Public awareness of rock-fall hazard in Yosemite Valley has heightened after events in 1996 and 1999. Reports of audible blasts prior to rock-fall events suggest that rock cracking may in some instances precede the detachment a block from the cliff face. Seismic methods may be used to detect and locate small, inaudible rock cracking events, resulting in a catalog that outlines active areas and quantifies the level of activity. In order to test the feasibility of monitoring rock-fall activity with seismic methods, the Test Yosemite Rock-Fall Network (TYRN) was operated in the late summer and fall of 1999. The TYRN included five stations in the vicinity of the 1999 rock fall events: 2 stations at the base of the cliff and 3 above. Location of events depends on an estimate of seismic-wave velocity. During the TYRN deployment, a septic tank near Glacier Point was demolished, allowing the velocity of seismic P-waves to be calibrated. P-wave velocity was found to be about 5.68 km/s. Recordings of the explosion also allow assessment of arrival time precision, which controls the precision of seismic locations. Explosion recordings suggest that P-waves can be picked with a precision of about 0.005 seconds, suggesting that a seismic monitoring system would be able to locate events on the cliff face with sufficient precision to be useful in rock-fall monitoring. We used the amplitude of seismic noise recorded on the test network to determine the smallest event likely to be detected by the TYRN . An event with equivalent earthquake magnitude of -2.6 would be detectable at a sufficient number of stations to afford a location. This magnitude is equivalent to about 1.8 centimeters of slip on a surface with area of 1 square meter. Smaller displacements would be detectable for larger slip surfaces. The vast majority of events recorded on the TYRN were from the Mammoth Lakes region. About 5 to 6 events from the Mammoth Lakes area were recorded per day, but considerably more events

  2. Rock fall photogrammetric monitoring in the active crater of Piton de la Fournaise volcano, La Reunion Island

    NASA Astrophysics Data System (ADS)

    Hibert, Clément; Dewez, Thomas; Mangeney, Anne; Grandjean, Gilles; Boissier, Patrice; Catherine, Philippe; Kowalski, Philippe

    2010-05-01

    The collapse of the active crater at Piton de la Fournaise volcano, La Reunion Island, 5th April 2007, offers a rare opportunity to observe frequent rock fall and granular landslides, and test new monitoring techniques. Events concern volumes ranging from single blocks to more massive cliff collapse. The purpose of the presentation is two fold: first, we present a comparison between a Digital Terrain Model (DTM) obtained prior to crater collapse and a DTM extracted from aerial photographs shot in October 2010 (before the eruptive crisis of November 2009 and January 2010). This provides an assessment of morphological changes at the scale of the crater. The second purpose is to describe slope instabilities on the south-western flank of the crater observed since October 2009. These ground-based observations were obtained from a pair of photogrammetric stations deployed along the northern and eastern edges of the crater. These works were conducted within UNDERVOLC project. With this monitoring system we mapped zones affected by rockfalls (departure and accumulation areas) and propose a first estimate of volumes of lava produced by the eruption affecting the inside of the crater since January 2.

  3. First results of repeated Terrestrial Laserscanning monitoring processes at the rock fall area Burgstall/Pasterze Glacier, Hohe Tauern Range, Central Austria

    NASA Astrophysics Data System (ADS)

    Avian, M.

    2012-04-01

    In July 2007 a large rock fall event at the NW-SE tending ridge of the mountain Mittlerer Burgstall (N47°05´, E12°44´) released appr. 57.000 m3 of rock accumulated at both sides of the ridge partly covering the tongue of Pasterze Glacier, the largest glacier in the Eastern European Alps. First analyses on the event were carried out based on pre- and post event airborne laserscanning as well as photogrammetric data. Ongoing large rock falls in 2008 led to the decision to establish a Terrestrial Laser Scanning (TLS) network to acquire high resolution 3D-surface data. The TLS position is complementary to the existing monitoring network installed in 2006, consisting of ground surface and near surface temperature sensors (projects: ALPCHANGE 2006 - 2011; permaNET 2008-2011; permAfrost 2010 - 2012). In August 2009 first investigations to install a permanent position for TLS to monitor affected rock fall areas were carried out. Unfavourable geometric as well as terrain conditions inhibited the installation of a position to monitor the SW-facing flank of Mittlerer Burgstall mountain. An ideal position to monitor the NE- facing area as well as the S- and E-flank of the nearby Hoher Burgstall was installed in September 2010 at the proglacial area of the Wasserfallwinkelkees glacier. This glacier was once contributing ice masses to the tongue of Pasterze Glacier and is now located about 400 m above the present surface of Pasterze Glacier. Similar to Mittlerer Burgstall, also both flanks of Hoher Burgstall show evidences of imminent larger rock falls which can be hazardous due to the fact that a frequented hiking trail leads to the Oberwalder Hütte alpine hut crosses the lower left part of the E-flank. This hut is a high alpine training centre of the Austrian Alpine club (OEAV) and well visited in during summer. First measurements of both study areas were carried out in September 2010 in mean distances of 600m to the scanning area of Mittlerer Burgstall (MBUG) and 100m to

  4. 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; 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

  5. Practical example of the infrastructure protection against rock fall

    NASA Astrophysics Data System (ADS)

    Jirásko, Daniel; Vaníček, Ivan

    2017-09-01

    The protection of transport infrastructures against rock falls represents for the Czech Republic one of the sensitive questions. Rock falls, similarly as other typical geo-hazards for the Czech Republic, as landslides and floods, can have negative impact on safety and security of these infrastructures. One practical example how to reduce risk of rock fall is described in the paper. Great care is devoted to the visual inspection enabling to indicate places with high potential to failure. With the help of numerical modelling the range of rock fall negative impact is estimated. Protection measures are dealing with two basic ways. The first one utilize the results of numerical modelling for the optimal design of protection measures and the second one is focused on the monitoring of the rock blocks with high potential of instability together with wire-less transfer of measured results. After quick evaluation, e.g. comparison with warning values, some protection measures, mostly connected with closure of the potential sector, can be recommended.

  6. Rock fall triggering from cyclic thermal forcing of exfoliation fractures

    NASA Astrophysics Data System (ADS)

    Collins, B. D.; Stock, G. M.

    2013-12-01

    Exfoliation of rocks cause cliffs to deteriorate through the formation and subsequent opening of fractures. Where human activities are exposed to this process, rock fall hazard is potentially high. A number of mechanisms (e.g., freeze-thaw, precipitation-induced seepage) are capable of triggering rock fall in steep rock masses, however, some rock falls occur in the absence of any identified trigger. Among the suggested causes for these unexplained rock falls is thermal heating which can lead to outward expansion of rock surfaces. Here we use data from three years of displacement transducer field monitoring and corroborated by lidar measurements to test this hypothesis by assessing the magnitude and temporal pattern of thermally-induced rock deformation in an exfoliating granitic landscape. We show that daily, seasonal, and annual temperature effects are sufficient to cause cyclic and cumulative deformation of fractures, and that fracture tip propagation with consequent detachment of rock masses likely results. We use thermodynamic and structural engineering principals to show that thermally-forced exfoliation surfaces (i.e., partially detached 'flakes' of rock) follow Carnot-cycle-type hysteresis loops (i.e., the cyclical conversion of thermal energy to work that occurs in a heat engine) and can be modeled by Euler-type buckling criteria (i.e., the resultant lateral deformation that occurs upon an increase in axial compressive loading, here, caused by thermal expansion along the axis of partially detached exfoliation flakes). Our data from a 19-m-tall, 4-m-wide, 10-cm-thick, instrumented granodiorite exfoliation flake indicate that cumulative annual outward deformation of up to 1 mm/yr occurs under fatigue crack growth conditions. These conditions are related to both cyclic thermal and mechanical forcing and gravitational loads acting along the surfaces that attach the flake to the rock mass. Based on these observations and our analyses, we suggest that the warmest

  7. 115. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    115. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; WEST VIEW OF SIPHON CROSSING ROCK CREEK. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  8. Automatic Fall Monitoring: A Review

    PubMed Central

    Pannurat, Natthapon; Thiemjarus, Surapa; Nantajeewarawat, Ekawit

    2014-01-01

    Falls and fall-related injuries are major incidents, especially for elderly people, which often mark the onset of major deterioration of health. More than one-third of home-dwelling people aged 65 or above and two-thirds of those in residential care fall once or more each year. Reliable fall detection, as well as prevention, is an important research topic for monitoring elderly living alone in residential or hospital units. The aim of this study is to review the existing fall detection systems and some of the key research challenges faced by the research community in this field. We categorize the existing platforms into two groups: wearable and ambient devices; the classification methods are divided into rule-based and machine learning techniques. The relative merit and potential drawbacks are discussed, and we also outline some of the outstanding research challenges that emerging new platforms need to address. PMID:25046016

  9. Automatic fall monitoring: a review.

    PubMed

    Pannurat, Natthapon; Thiemjarus, Surapa; Nantajeewarawat, Ekawit

    2014-07-18

    Falls and fall-related injuries are major incidents, especially for elderly people, which often mark the onset of major deterioration of health. More than one-third of home-dwelling people aged 65 or above and two-thirds of those in residential care fall once or more each year. Reliable fall detection, as well as prevention, is an important research topic for monitoring elderly living alone in residential or hospital units. The aim of this study is to review the existing fall detection systems and some of the key research challenges faced by the research community in this field. We categorize the existing platforms into two groups: wearable and ambient devices; the classification methods are divided into rule-based and machine learning techniques. The relative merit and potential drawbacks are discussed, and we also outline some of the outstanding research challenges that emerging new platforms need to address.

  10. Statistical Analyses of Historical Rock Falls in Yosemite National Park

    NASA Astrophysics Data System (ADS)

    Austin, L. J.; Stock, G. M.; Collins, B. D.

    2014-12-01

    The steep cliffs of Yosemite Valley produce dozens of rock falls each year that pose a hazard to the four million annual visitors to Yosemite National Park. To better understand rock-fall processes, we use 156 years of rock fall data to examine temporal and spatial correlations between rock falls and seasonality, environmental conditions, and rock type. We also investigate the complexity of rock fall triggers, the most notably precipitation-related triggers (precipitation, snowmelt, rain-on-snow), earthquakes, thermal stress, and freeze-thaw. Comparing rock fall occurrences and cumulative precipitation plots for 16 years between 1983 and 2011 demonstrates a temporal correlation between precipitation and rock falls; this is corroborated by the observation of 17 rock falls that occurred within a one-week period of significant precipitation in late winter 2014. Yet there are many rock falls that do not coincide with precipitation; we attribute these to other triggers when clear temporal correlations exist, or, lacking clear temporal correlations, we investigate possible factors involved in "unrecognized" triggers. The large number of rock falls in the database (925) affords the opportunity to establish a volume-frequency relation similar to that of earthquakes. We also investigate both the frequency and volume of rock falls for each significant lithologic unit exposed in Yosemite Valley and find that two units in particular, the granodiorite of Arch Rock and the granodiorite of Kuna Crest, produce higher rates of rock fall relative to the other lithologies. The aim of these analyses is to better understand conditions that contribute to rock fall and to increase understanding of rock-fall hazard within Yosemite National Park.

  11. Rock-fall potential in the Yosemite Valley, California

    USGS Publications Warehouse

    Wieczorek, G.F.; Morrissey, M.M.; Iovine, Giulio; Godt, Jonathan

    1999-01-01

    We used two methods of estimating rock-fall potential in the Yosemite Valley, California based on (1) physical evidence of previous rock-fall travel, in which the potential extends to the base of the talus, and (2) theoretical potential energy considerations, in which the potential can extend beyond the base of the talus, herein referred to as the rock-fall shadow. Rock falls in the valley commonly range in size from individual boulders of less than 1 m3 to moderate-sized falls with volumes of about 100,000 m3. Larger rock falls exceeding 100,000 m3, referred to as rock avalanches, are considered to be much less likely to occur based on the relatively few prehistoric rock-fall avalanche deposits in the Yosemite Valley. Because the valley has steep walls and is relatively narrow, there are no areas that are absolutely safe from large rock avalanches. The map shows areas of rock-fall potential, but does not predict when or how frequently a rock fall will occur. Consequently, neither the hazard in terms of probability of a rock fall at any specific location, nor the risk to people or facilities to such events can be assessed from this map.

  12. 113. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    113. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; CLOSE-UP OF INLET SIDE OF SIPHON, NORTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  13. 111. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    111. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OVERALL VIEW OF SIPHON, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  14. 112. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    112. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OUTLET SIDE, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  15. 93. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY ...

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

    93. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF KIMBERLY, IDAHO; OVERALL NORTHEAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  16. 116. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    116. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; CLOSE-UP OF OUTLET, DIVERSION SPILL IN BACKGROUND, WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  17. 114. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    114. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OVERALL VIEW, WEST OF INLET SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  18. 110. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY, ...

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

    110. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; INLET SIDE WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  19. Rock-fall hazards in the Yosemite Valley

    USGS Publications Warehouse

    Wieczorek, G.F.; Morrissey, M.M.; Iovine, Giulio; Godt, J.W.

    1998-01-01

    This report with map shows the areas of highest rock-fall hazard in four selected parts of Yosemite Valley, California, defined by the National Park Service. Two specific levels of hazard are recognized and identified from rock falls ranging in size from individual boulders to moderate-sized events with volumes of 100,000 m3. These different levels of hazard are associated with areas within the base of the talus (red line in Plate 1) and those normally beyond the base of the talus which we refer to as the rock-fall shadow (yellow line in Plate 1). Rock falls of even greater size, exceeding 100,000 m3, referred to as rock avalanches, are a potential hazard, but the extent of this hazard is not easily defined. Rock avalanches are considered to be much less likely to occur because of the relatively few prehistoric rock-fall avalanche deposits that have been recognized in the Yosemite Valley. With the configuration of the steep valley walls and the relatively narrow valley, it should be noted that there are no absolutely safe or zero probability areas from large rock avalanches. This study has shown in map form where rock-fall hazard exists and has given general indication of the expected frequency of these events; however, the study does not quantify the probability at any specific location, nor evaluate the risk to people or facilities to such events.

  20. Infrasound from Rock Fall at Santiaguito Volcano, Guatemala

    NASA Astrophysics Data System (ADS)

    Ronan, T.; Terbush, B.; Miller, A. J. C.; Anderson, J.; Johnson, J. B.

    2014-12-01

    Volcanoes generate infrasound from incidental rock fall and from rock fall directly associated with eruptions. This study demonstrates that arrays of infrasound microphones are capable of surveillance and quantification of rock fall events, including their size, location, velocity and frequency of occurrence. The study performed at Volcan Santiaguito (Guatemala) in January 2014 made use of a three element infrasound array with 30 m aperture deployed ~500 m from the active vent and ~300 m from the slide path where numerous rock falls descend. Rock fall events were detected on average 5 to 10 times per hour and were easily distinguishable from vent activity (e.g., explosions) by their dynamic back azimuth projection. As blocks tumbled down the southwest flanks of Santiaguito, sources were tracked across an azimuthal range of nearly 30 degrees, consistent with the dome's slope. Back azimuths, determined with a [progressive] multichannel cross correlation technique, are projected to the volcano's steep flanks and are used to precisely locate the source of infrasound (i.e., rocks impacting on the volcano slopes) and their velocity (10-30 m/s). Typical signals last about one minute and are characterized by cigar-shaped tremor envelopes with a predominance of energy above ~5 Hz this spectral content contrasts with Santiaguito eruption infrasound, which is peaked at ~1 Hz. Synchronous video records of the responsible rock fall confirm position and velocity and illustrate that even the smallest rock falls (estimated block size of ~1 m) are capable of producing a traceable signal. This study is a testament to the capabilities of infrasound array remote sensing for detecting volcanic unrest in the form of rock fall, which is common at most active silicic domes.

  1. Lidar-Based Rock-Fall Hazard Characterization of Cliffs

    USGS Publications Warehouse

    Collins, Brian; 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.

  2. Thermal controls on exfoliation and rock falls in Yosemite National Park, California

    NASA Astrophysics Data System (ADS)

    Stock, G. M.; Collins, B. D.; Martel, S. J.

    2012-12-01

    Yosemite National Park is a glaciated granitic landscape dominated by sheeting (exfoliation) joints, opening mode fractures that develop approximately parallel to topographic surfaces. Numerous rock falls detach along sheeting joints each year in Yosemite Valley. Recent remote sensing studies of rock-fall detachment surfaces suggest that, in many cases, failure occurred as sheeting joints propagated beyond a critical stability threshold. Although joint propagation can occur in response to changes in local stress conditions, environmental forces are the most common rock-fall triggers in Yosemite. An analysis of 650 rock falls shows that nearly 50% of rock falls are temporally correlated with rainfall or snowmelt events, 6% are triggered by seismicity, and about 4% are associated with inferred stress redistribution and crack propagation following previous rock falls. Only 7% of documented rock falls are correlated with known freeze-thaw conditions, suggesting that this well-known process of fracturing rock is not a major rock-fall trigger in Yosemite. Thirty-three percent of documented rock falls have "unrecognized" triggers, meaning that despite close observation, reliable correlations with obvious environmental triggers cannot be made; many of these puzzling events occur on clear, warm summer days. Our monitoring of an exfoliation sheet, partially detached along a cliff-parallel sheeting joint, demonstrates how warm temperatures can play an important role in destabilizing rock sheets. The 14 m tall by 4 m wide by 10 cm thick sheet, instrumented with crackmeters and temperature and solar radiation sensors, deforms on daily, seasonal, and annual timescales in response to changes in air temperature and, to a lesser extent, solar radiation. Daily deformation (change in joint aperture) exceeds 1 cm on those days with the highest temperature gradients (up to 35°C/day). Monitoring of the sheet over a two-year period indicates that irreversible deformation is occurring

  3. 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.

  4. Investigation and hazard assessment of the 2003 and 2007 Staircase Falls rock falls, Yosemite National Park, California, USA

    USGS Publications Warehouse

    Wieczorek, G.F.; Stock, Gregory M.; Reichenbach, P.; Snyder, J.B.; Borchers, J.W.; Godt, J.W.

    2008-01-01

    Since 1857 more than 600 rock falls, rock slides, debris slides, and debris flows have been documented in Yosemite National Park, with rock falls in Yosemite Valley representing the majority of the events. On 26 December 2003, a rock fall originating from west of Glacier Point sent approximately 200 m 3 of rock debris down a series of joint-controlled ledges to the floor of Yosemite Valley. The debris impacted talus near the base of Staircase Falls, producing fragments of flying rock that struck occupied cabins in Curry Village. Several years later on 9 June 2007, and again on 26 July 2007, smaller rock falls originated from the same source area. The 26 December 2003 event coincided with a severe winter storm and was likely triggered by precipitation and/or frost wedging, but the 9 June and 26 July 2007 events lack recognizable triggering mechanisms. We investigated the geologic and hydrologic factors contributing to the Staircase Falls rock falls, including bedrock lithology, weathering, joint spacing and orientations, and hydrologic processes affecting slope stability. We improved upon previous geomorphic assessment of rock-fall hazards, based on a shadow angle approach, by using STONE, a three-dimensional rock-fall simulation computer program. STONE produced simulated rock-fall runout patterns similar to the mapped extent of the 2003 and 2007 events, allowing us to simulate potential future rock falls from the Staircase Falls detachment area. Observations of recent rock falls, mapping of rock debris, and simulations of rock fall runouts beneath the Staircase Falls detachment area suggest that rock-fall hazard zones extend farther downslope than the extent previously defined by mapped surface talus deposits.

  5. Unobtrusive monitoring and identification of fall accidents.

    PubMed

    van de Ven, Pepijn; O'Brien, Hugh; Nelson, John; Clifford, Amanda

    2015-05-01

    Falls are a societal and economic problem of great concern with large parts of the population, in particular older citizens, at significant risk and the result of a fall often being grave. It has long been established that it is of importance to provide help to a faller soon after the event to prevent complications and this can be achieved with a fall monitor. Yet, the practical use of currently available fall monitoring solutions is limited due to accuracy, usability, cost, and, not in the least, the stigmatising effect of many solutions. This paper proposes a fall sensor concept that can be embedded in the user's footwear and discusses algorithms, software and hardware developed. Sensor performance is illustrated using results of a series of functional tests. These show that the developed sensor can be used for the accurate measurement of various mobility and gait parameters and that falls are detected accurately.

  6. Rock falls from Glacier Point above Camp Curry, Yosemite National Park, California

    USGS Publications Warehouse

    Wieczorek, Gerald F.; Snyder, James B.

    1999-01-01

    A series of rock falls from the north face of Glacier Point above Camp Curry, Yosemite National Park, California, have caused reexamination of the rock-fall hazard because beginning in June, 1999 a system of cracks propagated through a nearby rock mass outlining a future potential rock fall. If the estimated volume of the potential rock fall fails as a single piece, there could be a risk from rock-fall impact and airborne rock debris to cabins in Camp Curry. The role of joint plane orientation and groundwater pressure in the fractured rock mass are discussed in light of the pattern of developing cracks and potential modes of failure.

  7. Dynamic characterization of the Chamousset rock column before its fall

    NASA Astrophysics Data System (ADS)

    Levy, C.; Baillet, L.; Jongmans, D.

    2009-04-01

    The rockfall of Chamousset (volume of 21000m3 ) occurred on November 10, 2007, affecting the 300 m high Urgonian cliff of the southern Vercors massif, French Alps. This event took place when the Vercors plateau was covered by snow. The unstable column was previously detected by observations on the development of a 30 m long fracture back on the plateau. Two aerial Lidar scans of the cliff were acquired before and after the failure, allowing the geometry of the column and of the broken plane to be determined. A temporary seismic array along with two extensometers was installed from July to November 2007. The seismic array consisted of 7 short period seismometers (1 three-components and 6 vertical-component). One vertical seismometer was installed on the column while the other 6 were deployed on the plateau with an array aperture of about 70 m. During the last two months of record, short period seismometers were replaced by 4.5 Hz geophones. The monitoring system recorded in a continuous mode (1000 Hz of frequency sampling) but it stopped to work two weeks before the fall, after the solar panels were covered by snow. During the running period, the seismic array recorded hundreds of local seismic events, from short (less than 0.5 s) impulsive signals to events with a long duration (a few tens of seconds). Our study was first focused on the dynamic response of the column and on the seismic noise frequency content. Fourier spectra of the seismic noise signals recorded on the column and the corresponding spectral ratios showed the presence of several resonance frequencies of the column. The first resonance frequency was measured at 3.6 Hz in July 2007 and it decreases regularly with time to reach 2.6 Hz two weeks before the fall. In parallel, extensometer measurements show that the fracture aperture increased with time during the same period. The dynamic response of a block which separates from a rock mass was 2D numerically modelled. Finite element computations showed

  8. Five seasons of chalk cliff face erosion monitored by terrestrial laser scanner: from quantitative description to rock fall probabilistic hazard assessment

    NASA Astrophysics Data System (ADS)

    Dewez, T.; Chamblas, G.; Lasseur, E.; Vandromme, R.

    2009-04-01

    Coastal cliffs are ubiquitous landforms around the world and cliff recession is a major subject of concern to coastal communities. These elements argue for a better understanding of processes occurring along coastal cliffs. The purpose of the study is to carefully describe the phenomenology of erosion on an evolving chalk coastline. Six repeated terrestrial laser scanner surveys were carried out for 2.5 years on a 700-m-long coastal chalk (Lewes Chalk - Upper Cretaceous) cliff site at Mesnil Val in Normandy, a setting representative of about a quarter of the English Channel's chalky coast. We describe the methodology used to process digital surface models and the novel technique developed to discriminate erosion from noise and to build a catalogue of eroded patches. Terrestrial Laser Scanner surveys permit the detection of any erosion patch thicker than ca. 3 cm. The catalogue of erosion patches contains more than 8500 objects with volumes spanning eight orders of magnitude, from 10-4 m3 up to 104m3. The average erosion rate is 0.13 m/a if one excludes a rare single massive cliff collapse event of 70 000 m3that occurred in March 2008, or 0.94 m/a if this event is included. A scaling power law relationship exists between event volume and chalk production that implies that erosion is not dominated by any characteristic event. This scaling relationship is different for summers and winters showing clearly that more chalk is eroded in small patches in the winter than in the summer, whereas erosion of blocks larger than 10m3 are just as probable in the summer as in the winter. Probabilistic block fall hazard relationships were derived in order to predict the recurrence of events of a given size. The relationship between block fall volume and frequency takes the shape of a negative power law : F = a V -b, with F being the frequency, V the volume of a block, a = 53.568 and b = 0.51. We draw the conclusion that repeated topographic surveys with terrestrial laser scanners

  9. Quantitative rock-fall hazard and risk assessment for Yosemite Valley, Yosemite National Park, California

    USGS Publications Warehouse

    Stock, Greg M.; Luco, Nicolas; Collins, Brian D.; Harp, Edwin L.; Reichenbach, Paola; Frankel, Kurt L.

    2014-01-01

    Rock falls are common in Yosemite Valley, California, posing substantial hazard and risk to the approximately four million annual visitors to Yosemite National Park. Rock falls in Yosemite Valley over the past few decades have damaged structures and caused injuries within developed regions located on or adjacent to talus slopes highlighting the need for additional investigations into rock-fall hazard and risk. This assessment builds upon previous investigations of rock-fall hazard and risk in Yosemite Valley and focuses on hazard and risk to structures posed by relatively frequent fragmental-type rock falls as large as approximately 100,000 (cubic meters) in volume.

  10. STONE: a computer program for the three-dimensional simulation of rock-falls

    NASA Astrophysics Data System (ADS)

    Guzzetti, Fausto; Crosta, Giovanni; Detti, Riccardo; Agliardi, Federico

    2002-11-01

    Rock-fall poses a continuous hazard in mountain areas worldwide. Despite the fact that rock fall is a simple landslide type to model, only a few attempts have been made to establish rock-fall hazard and the associated risk at regional scales. We developed a three-dimensional simulation program that generates simple maps useful to assess rock-fall hazard, using GIS technology to manipulate existing thematic information available in digital format. The program requires as input a digital terrain model, the location of rock-fall detachment areas, the dynamic friction coefficient used to simulate the loss of velocity during rolling, and the coefficients for normal and tangential energy restitution at the impact points. The program allows for the natural variability of the input data by using a random component approach. Raster outputs include the count of rock-fall trajectories, the maximum velocity and the maximum height computed at each grid cell. Vector outputs consist of the planar (two dimensional) and the three-dimensional trajectories of the rock falls. The program outputs proved to be consistent with the results of other rock-fall simulation programs, to be reliable for modelling rock-fall in three-dimensional geomorphological settings, and to help in the quantitative assessment of rock-fall hazard over large areas.

  11. Disposable falling sensors to monitor atmospheric parameters

    NASA Astrophysics Data System (ADS)

    Bertoldo, S.; Lucianaz, C.; Allegretti, M.; Perona, G.

    2016-10-01

    Detailed studies and researches about clouds and precipitations characterization are considered to play a key role in weather and strong events prediction. Most monitoring instruments perform indirect monitoring operation, sensing the parameters from a remote position and not being directly inside the phenomenon. A feasibility analysis of a set of disposable sensors is presented. The very light sensors are planned to be dropped by a plane or a UAV (Unmanned Aerial Vehicle) in the atmosphere and are designed to dynamically behave as very light particles similar to raindrops in their fluctuations and falling through the atmosphere. In order to realize sensing probes with a similar fluid-dynamic behavior of drops, the weight, the size and the surface properties of the probes should be carefully designed. An estimated size of the order of many centimeters and a total weight of less than 15 g is needed. Consequently particular attention has to be paid in designing electronic boards and in the choice of integrated measurement sensors as well as the transmitter. Minimum power consumption should be also guaranteed, in order to assure the proper working during the fluctuating and falling time. Sensors installed on the sensing probe will measure different atmospheric parameters (e.g. humidity, temperature, pressure, acceleration) with a sampling interval of the order of some milliseconds. All data are then sent to a receiver located on the ground and can then be stored and post processed for further analysis.

  12. Taking a Whipper--The Fall-Factor Concept in Rock Climbing

    ERIC Educational Resources Information Center

    Curtis, Dan

    2005-01-01

    Most serious rock climbers are familiar with a counter-intuitive fact about their sport: The force experienced by a falling climber due to the rope as it arrests his fall does not depend simply on the length of the fall, but rather on a ratio called the fall-factor. This article explains, using elementary physics and simple differential equations,…

  13. Taking a Whipper--The Fall-Factor Concept in Rock Climbing

    ERIC Educational Resources Information Center

    Curtis, Dan

    2005-01-01

    Most serious rock climbers are familiar with a counter-intuitive fact about their sport: The force experienced by a falling climber due to the rope as it arrests his fall does not depend simply on the length of the fall, but rather on a ratio called the fall-factor. This article explains, using elementary physics and simple differential equations,…

  14. 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.

  15. 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.

  16. Historical rock falls in Yosemite National Park, California (1857-2011)

    USGS Publications Warehouse

    Stock, Greg M.; Collins, Brian D.; Santaniello, David J.; Zimmer, Valerie L.; Wieczorek, Gerald F.; Snyder, James B.

    2013-01-01

    Inventories of rock falls and other types of landslides are valuable tools for improving understanding of these events. For example, detailed information on rock falls is critical for identifying mechanisms that trigger rock falls, for quantifying the susceptibility of different cliffs to rock falls, and for developing magnitude-frequency relations. Further, inventories can assist in quantifying the relative hazard and risk posed by these events over both short and long time scales. This report describes and presents the accompanying rock fall inventory database for Yosemite National Park, California. The inventory database documents 925 events spanning the period 1857–2011. Rock falls, rock slides, and other forms of slope movement represent a serious natural hazard in Yosemite National Park. Rock-fall hazard and risk are particularly relevant in Yosemite Valley, where glacially steepened granitic cliffs approach 1 km in height and where the majority of the approximately 4 million yearly visitors to the park congregate. In addition to damaging roads, trails, and other facilities, rock falls and other slope movement events have killed 15 people and injured at least 85 people in the park since the first documented rock fall in 1857. The accompanying report describes each of the organizational categories in the database, including event location, type of slope movement, date, volume, relative size, probable trigger, impact to humans, narrative description, references, and environmental conditions. The inventory database itself is contained in a Microsoft Excel spreadsheet (Yosemite_rock_fall_database_1857-2011.xlsx). Narrative descriptions of events are contained in the database, but are also provided in a more readable Adobe portable document format (pdf) file (Yosemite_rock_fall_database_narratives_1857-2011.pdf) available for download separate from the database.

  17. An engineering rock classification to evaluate seismic rock-fall susceptibility and its application to the Wasatch front

    SciTech Connect

    Harp, E.L.; Noble, M.A.

    1993-09-01

    The authors examine the characteristics of rock slopes that make them susceptible to failures caused by earthquakes. They discuss these characteristics, namely the fracture and joint properties that define the structural behavior of a rock mass at the surface, and then present an empirical engineering classification or ranking system that rates the relative seismic susceptibility of rock masses. They next apply the engineering classification in a case study of seismically-triggered rock falls in the Mammoth Lakes area. The engineering classification is correlated with the concentration of seismically-triggered rock falls, and the resulting statistical model can be used to predict the probability of a rock fall for a given magnitude earthquake. Finally, they apply the classification and probability analysis to similar slopes in the Wasatch Range near Salt Lake City and evaluate the relative susceptibility of slopes in this area to seismically-induced failure.

  18. An engineering rock classification to evaluate seismic rock-fall susceptibility and its application to the Wasatch Front

    USGS Publications Warehouse

    Harp, E.L.; Noble, M.A.

    1993-01-01

    Investigations of earthquakes world wide show that rock falls are the most abundant type of landslide that is triggered by earthquakes. An engineering classification originally used in tunnel design, known as the rock mass quality designation (Q), was modified for use in rating the susceptibility of rock slopes to seismically-induced failure. Analysis of rock-fall concentrations and Q-values for the 1980 earthquake sequence near Mammoth Lakes, California, defines a well-constrained upper bound that shows the number of rock falls per site decreases rapidly with increasing Q. Because of the similarities of lithology and slope between the Eastern Sierra Nevada Range near Mammoth Lakes and the Wasatch Front near Salt Lake City, Utah, the probabilities derived from analysis of the Mammoth Lakes region were used to predict rock-fall probabilities for rock slopes near Salt Lake City in response to a magnitude 6.0 earthquake. These predicted probabilities were then used to generalize zones of rock-fall susceptibility. -from Authors

  19. Uranium-bearing coal and carbonaceous rocks in the Fall Creek area, Bonneville County, Idaho

    USGS Publications Warehouse

    Vine, James D.; Moore, George Winfred

    1952-01-01

    Uraniferous coal, carbonaceous shale, and carbonaceous limestone occur in the Bear River formation of Early Cretaceous age at the Fall Creek prospect, in the Fall Creek area, Bonneville County, Idaho. The uranium compounds are believed to have been derived from mildly radioactive silicic volcanic rocks of Tertiary age that rest unconformably on all older rocks and once overlay the Bear River formation and its coal. Meteoric water, percolating downward through the silicic volcanic rocks and into the older rocks along joints and faults, is believed to have brought the uranium compounds into contact with the coal and carbonaceous rocks in which the uranium was absorbed.

  20. Frequency-volume Statistics of Rock Falls: Examples From France, Italy and California

    NASA Astrophysics Data System (ADS)

    Dussauge-Peisser, C.; Guzzetti, F.; Wieczorek, G. F.

    There is accumulating evidence that the distribution of rock-fall volume exhibits power law (fractal) statistics in different physiographic and geologic environments. We have studied the frequency-volume statistics of rock falls in three areas: Grenoble, France; Umbria, Italy; and Yosemite Valley, California, USA. We present a compari- son of the datasets currently available. For the Grenoble area a catalogue of rock falls between 1248 and 1995 occurred along a 120 km long limestone cliff. The dataset contains information on 105 rock-fall events ranging in size from 3xE-2 to 5xE8 m3. Only the time window 1935-1995 is considered in the study, involving 87 events from 1E-2 to 1E6 m3. The cumulative frequency-volume statistics follow a power-law (frac- tal) relationship with exponent b = -0.4 over the range 50 m3 Rock falls in Umbria were triggered by earthquakes during September and October of 1997. The main shocks (M = 5.5-5.8) and some of the most severe aftershocks triggered numerous rock falls up to a distance of 19 km from the epicenters. For 67 rock falls the volume of the failed mass was estimated in the field to range between 5E-4 and 2E2 m3. The non-cumulative frequency statistics of rock-fall volume obey a power law relationship with an exponent beta = -1.7 over the range 1 m3 < V < 2E2 m3. For the Yosemite Valley the database contains information on historical (1851-2001) rock falls (122), rock slides (251) and prehistoric rock avalanches (5). For Yosemite, the non-cumulative frequency-volume statistics of rock falls and rock slides are very sim- ilar and correlate well with a power-law (fractal) relation with exponent beta = -1.4, over the range 30 m3 rock avalanches. We discuss the implications of such a power law fitting the data for rock-fall hazard assessment. We also discuss the variation of the b and beta exponents for natural events and earthquake triggered events.

  1. Rock fall analysis of slope along state highway in Uttarakhand Himalaya, India using numerical simulation

    NASA Astrophysics Data System (ADS)

    Vishal, V.; Phophliya, M. K.; Purohit, R.

    2014-12-01

    With almost 1% of the reported accidents being associated with slope stability problems, landslides and rock fall have been responsible for nearly 25% of fatalities in hill slopes and surface mines over past few decades. Morpho-dynamic terrain of Himalaya is continually facing challenges in stability of rock/slopes, which are aggravated due to increased disturbance level in rock/soil mass due to human intervention. The lithological and structural variations, orientations and patterns of different water bodies and vegetation are varied along the slopes which indicate site-specific studies of rock fall prone areas in Uttarakhand. Lack of sufficient knowledge and understanding of the phenomenon, frequent occurrences of rock fall along state and national highways, the consequent inconveniences and loss of lives highlight the importance of addressing the subject on a priority basis. Rock fall simulation of the hill cut face along state highway in India was performed to replicate the effects of the falling rock blocks in the valley. The energy, velocity, bounce height and the trajectory of possible rock failures were determined. The slopes were optimised with respect to the intermediate benches to reduce the impact of falling rock blocks on the adjoining road. It was observed that introducing benches near the top did not reduce the impact of falling boulders much, however, the number of rocks crossing the ditch was less. On the contrary, benches at intermediate height reduced the energy of falling blocks but could not restrict the blocks to cross over the ditch on to the road. An optimisation of the angle of inclination of the ditch angle was also carried out. A ditch angle of 15o could restrict the passage of boulders from ditch over to the adjoining road. The study will be very useful for safe design of structures for prevention and mitigation of hazards due to rock failures along these slopes.

  2. Remote Video Monitoring: A Novel Approach in Fall Prevention.

    PubMed

    Bradley, Kenesha

    2016-11-01

    Adequate fall prevention interventions are a challenge that nurses continue to endure. Remote video monitoring can be used in conjunction with other fall prevention interventions. This article describes remote video monitoring technology and the benefits and challenges associated with its implementation. J Contin Educ Nurs. 2016;47(11):484-486.

  3. Quantitative rock-fall hazard and risk assessment for Yosemite Valley, California

    NASA Astrophysics Data System (ADS)

    Stock, G. M.; Luco, N.; Collins, B. D.; Harp, E.; Reichenbach, P.; Frankel, K. L.

    2011-12-01

    Rock falls are a considerable hazard in Yosemite Valley, California with more than 835 rock falls and other slope movements documented since 1857. Thus, rock falls pose potentially significant risk to the nearly four million annual visitors to Yosemite National Park. Building on earlier hazard assessment work by the U.S. Geological Survey, we performed a quantitative rock-fall hazard and risk assessment for Yosemite Valley. This work was aided by several new data sets, including precise Geographic Information System (GIS) maps of rock-fall deposits, airborne and terrestrial LiDAR-based point cloud data and digital elevation models, and numerical ages of talus deposits. Using Global Position Systems (GPS), we mapped the positions of over 500 boulders on the valley floor and measured their distance relative to the mapped base of talus. Statistical analyses of these data yielded an initial hazard zone that is based on the 90th percentile distance of rock-fall boulders beyond the talus edge. This distance was subsequently scaled (either inward or outward from the 90th percentile line) based on rock-fall frequency information derived from a combination of cosmogenic beryllium-10 exposure dating of boulders beyond the edge of the talus, and computer model simulations of rock-fall runout. The scaled distances provide the basis for a new hazard zone on the floor of Yosemite Valley. Once this zone was delineated, we assembled visitor, employee, and resident use data for each structure within the hazard zone to quantitatively assess risk exposure. Our results identify areas within the new hazard zone that may warrant more detailed study, for example rock-fall susceptibility, which can be assessed through examination of high-resolution photographs, structural measurements on the cliffs, and empirical calculations derived from LiDAR point cloud data. This hazard and risk information is used to inform placement of existing and potential future infrastructure in Yosemite Valley.

  4. Unusual July 10, 1996, rock fall at Happy Isles, Yosemite National Park, California

    USGS Publications Warehouse

    Wieczorek, G.F.; Snyder, J.B.; Waitt, R.B.; Morrissey, M.M.; Uhrhammer, R.A.; Harp, E.L.; Norris, R.D.; Bursik, M.I.; Finewood, L.G.

    2000-01-01

    Effects of the July 10, 1996, rock fall at Happy Isles in Yosemite National Park, California, were unusual compared to most rock falls. Two main rock masses fell about 14 s apart from a 665-m-high cliff southeast of Glacier Point onto a talus slope above Happy Isles in the eastern part of Yosemite Valley. The two impacts were recorded by seismographs as much as 200 km away. Although the impact area of the rock falls was not particularly large, the falls generated an airblast and an abrasive dense sandy cloud that devastated a larger area downslope of the impact sites toward the Happy Isles Nature Center. Immediately downslope of the impacts, the airblast had velocities exceeding 110 m/s and toppled or snapped about 1000 trees. Even at distances of 0.5 km from impact, wind velocities snapped or toppled large trees, causing one fatality and several serious injuries beyond the Happy Isles Nature Center. A dense sandy cloud trailed the airblast and abraded fallen trunks and trees left standing. The Happy Isles rock fall is one of the few known worldwide to have generated an airblast and abrasive dense sandy cloud. The relatively high velocity of the rock fall at impact, estimated to be 110-120 m/s, influenced the severity and areal extent of the airblast at Happy Isles. Specific geologic and topographic conditions, typical of steep glaciated valleys and mountainous terrain, contributed to the rock-fall release and determined its travel path, resulting in a high velocity at impact that generated the devastating airblast and sandy cloud. The unusual effects of this rock fall emphasize the importance of considering collateral geologic hazards, such as airblasts from rock falls, in hazard assessment and planning development of mountainous areas.

  5. Quantitative rock-fall hazard and risk assessment for Yosemite Valley, Yosemite National Park, California

    USGS Publications Warehouse

    Stock, Greg M.; Luco, Nicolas; Collins, Brian D.; Harp, Edwin L.; Reichenbach, Paola; Frankel, Kurt L.

    2012-01-01

    caused injuries within developed regions located on or adjacent to talus slopes, highlighting the need for additional investigations into rock-fall hazard and risk. This assessment builds upon previous investigations of rock fall hazard and risk in Yosemite Valley (Wieczorek et al., 1998, 1999; Guzzetti et al., 2003; Wieczorek et al., 2008), and focuses on hazard and risk to structures posed by relatively frequent fragmental-type rock falls (Evans and Hungr, 1999), up to approximately 100,000 m3 in volume.

  6. A contribution for predicting Tsunami inundation induced by rock fall along the Gaeta cliff (Central Italy)

    NASA Astrophysics Data System (ADS)

    di Manna, P.; Vittori, E.; Comerci, V.; Amanti, M.; Cesi, C.

    2009-04-01

    Many sectors of Italian coasts are characterized by tall scarps, close to large or pocket beaches that display ramp shape with moderate to low acclivity profile. During the summer, all these beaches are densely populated by sunbathers. Moreover, Italian coastal areas are often intensely urbanized even at a short distance from the sea and very close to sea level. Being cliffs often affected by gravity processes, the impact on the water of a falling volume of rock, depending on size and height of fall, may represent a potential source of tsunami-type hazard for adjacent beaches and boats. In this work we present an attempt to evaluate the run-up and ingression values in the Serapo beach (Gaeta, Tyrrhenian Sea coast of Central Italy) of an anomalous wave induced by a potential rock fall along the contiguous more than 100 meters high limestone cliff (the so-called Montagna Spaccata, "cleft mountain"). Detailed geological and geomorphological field analyses are being carried out, including geomechanical analyses and geodetic monitoring, in order to recognize the sectors with the most critical stability conditions. Preliminarily, the major potential volume of instable block and its most likely kinematics have been estimated with the purpose of characterizing the rock fall process. The first water rise produced by the impact of the rock on the sea surface has been estimated according to two approaches: a) the Murty (2003) equation, that gives the relation between water elevation and volume of fallen material; b) the Glasstone and Dolan method (Hills & Mader, 1997), comparing the carbonate rock fall to a meteoritic impact on the sea surface. The rockfall kinematics suggests that the Glasstone and Dolan equation, despite it was developed for a different environment, is better applicable than Murty's (valid for slides) to the case under discussion. On the basis of the Green's law (1837) we defined the shoaling component of the run-up values. Our results show that the impact

  7. Probabilistic approach to rock fall hazard assessment: potential of historical data analysis

    NASA Astrophysics Data System (ADS)

    Dussauge-Peisser, C.; Helmstetter, A.; Grasso, J.-R.; Hantz, D.; Desvarreux, P.; Jeannin, M.; Giraud, A.

    We study the rock fall volume distribution for three rock fall inventories and we fit the observed data by a power-law distribution, which has recently been proposed to describe landslide and rock fall volume distributions, and is also observed for many other natural phenomena, such as volcanic eruptions or earthquakes. We use these statistical distributions of past events to estimate rock fall occurrence rates on the studied areas. It is an alternative to deterministic approaches, which have not proved successful in predicting individual rock falls. The first one concerns calcareous cliffs around Grenoble, French Alps, from 1935 to 1995. The second data set is gathered during the 1912-1992 time window in Yosemite Valley, USA, in granite cliffs. The third one covers the 1954-1976 period in the Arly gorges, French Alps, with metamorphic and sedimentary rocks. For the three data sets, we find a good agreement between the observed volume distributions and a fit by a power-law distribution for volumes larger than 50 m3 , or 20 m3 for the Arly gorges. We obtain similar values of the b exponent close to 0.45 for the 3 data sets. In agreement with previous studies, this suggests, that the b value is not dependant on the geological settings. Regarding the rate of rock fall activity, determined as the number of rock fall events with volume larger than 1 m3 per year, we find a large variability from one site to the other. The rock fall activity, as part of a local erosion rate, is thus spatially dependent. We discuss the implications of these observations for the rock fall hazard evaluation. First, assuming that the volume distributions are temporally stable, a complete rock fall inventory allows for the prediction of recurrence rates for future events of a given volume in the range of the observed historical data. Second, assuming that the observed volume distribution follows a power-law distribution without cutoff at small or large scales, we can extrapolate these

  8. 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.

  9. Spatial and temporal variability of rock fall in a (peri)glacial environment: a LiDAR-based, multi-year investigation of rock fall release zones and volumes, Kitzsteinhorn, Austria

    NASA Astrophysics Data System (ADS)

    Delleske, Robert; Hartmeyer, Ingo; Keuschnig, Markus; Götz, Joachim

    2014-05-01

    Rock instabilities in high mountain areas pose an important threat to man and infrastructure. Numerous observations from the European Alps suggest an increasing occurrence of rock fall events that might stand in direct relation to recent atmospheric warming. Laboratory testing of rock- and ice-mechanics indicates that rising temperatures potentially have a distinct destabilizing effect on steep rock faces underlain by permafrost. However, unbiased field data on spatial and temporal distribution of rock fall events in high alpine environments is usually scarce. Most investigations rely on strongly biased visual observations and/or sporadic optical measurements. This contribution addresses the need for more systematic and objective field data by presenting a multi-year TLS (terrestrial laserscanning) data series from a high alpine (peri)glacial environment, which is corroborated by data from local weather stations, near-surface rock temperatures, and visual observations. The presented work has been conducted within the currently running research project MOREXPERT ('Developing a Monitoring Expert System for Hazardous Rock Walls') whose study area is located at the Kitzsteinhorn (3.203 m), Hohe Tauern Range, Austria. The area surrounding the Kitzsteinhorn is easily accessible (tourist infrastructure, cable car) and possesses numerous rock faces that are intensely affected by glacier-permafrost interactions. Four scan positions that offer views of different rock faces have been selected for the acquisition of TLS data. The investigated rock faces, which predominantly consist of calcareous mica-schist, differ in height, slope, aspect, and discontinuity orientation. Scanned rock faces include Kitzsteinhorn N and NW face, Magnetkoepfl W and E face, Maurerkogel E face and Schmiedinger W face. The beginning of the TLS campaign at the Kitzsteinhorn dates back to July 2011. Since then scans have been repeated at an interval of 1-2 months during the summer season (June to

  10. Fall prevention and bathroom safety in the epilepsy monitoring unit.

    PubMed

    Spritzer, Scott D; Riordan, Katherine C; Berry, Jennnifer; Corbett, Bryn M; Gerke, Joyce K; Hoerth, Matthew T; Crepeau, Amy Z; Drazkowski, Joseph F; Sirven, Joseph I; Noe, Katherine H

    2015-07-01

    Falls are one of the most common adverse events occurring in the epilepsy monitoring unit (EMU) and can result in significant injury. Protocols and procedures to reduce falls vary significantly between institutions as it is not yet known what interventions are effective in the EMU setting. This study retrospectively examined the frequency of falls and the impact of serial changes in fall prevention strategies utilized in the EMU between 2001 and 2014 at a single institution. Overall fall rate was 2.81 per 1000 patient days and varied annually from 0 to 9.02 per 1000 patient days. Both seizures and psychogenic nonepileptic events occurring in the bathroom were more likely to result in falls compared with events occurring elsewhere in the room. With initiation of increased patient education, hourly nurse rounding, nocturnal bed alarms, having two persons assisting for high fall risk patients when out of bed, and immediate postfall team review between 2001 and 2013, there was a trend of decreasing fall frequency; however, no specific intervention could be identified as having a particular high impact. In late 2013, a ceiling lift system extending into the bathroom was put in place for use in all EMU patients when out of bed. In the subsequent 15 months, there have been zero falls. The results reinforce both the need for diligent safety standards to prevent falls in the EMU as well as the challenges in identifying the most effective practices to achieve this goal.

  11. Regional hydrogeology of the Silurian and Ordovician sedimentary rock underlying Niagara Falls, Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Novakowski, Kentner S.; Lapcevic, Patricia A.

    1988-12-01

    Due to concern over the potential for widespread groundwater contamination in the sedimentary rock underlying the Niagara Falls area, this study was done to investigate the hydrogeology of the Silurian and Ordovician stratigraphy underlying the Upper Niagara River and the Eastern Niagara Peninsula. Seven boreholes (up to 150 m deep) were drilled, instrumented with multiple packer casing, tested for permeability, sampled for inorganic and organic solutes and monitored for hydraulic head to provide data for a conceptual model of regional groundwater flow. Results show that there are at least three distinct groundwater flow regimes in the bedrock. The uppermost regime consists of fracture zones in the Guelph and Lockport Formations, within which hydraulic conductivity, hydraulic head measurements and geochemical analyses indicate active groundwater circulation primarily discharging towards the Niagara Gorge and Escarpment. Underlying the Lockport Formation are an overpressured (high hydraulic head) regime in the Clinton-Upper Cataract-Lower Queenston Formation and an underpressured (low hydraulic head) regime in the Lower Cataract-Upper Queenston Formation. In both regimes, geochemical analyses and permeability measurements indicate very old and saline groundwater which probably has undergone minimal migration since pre-Pleistocene time. The implication based on the study so far, is that potential groundwater contamination below the bottom of the Lockport Formation is probably not significant in the Niagara Falls area except adjacent to the Niagara Gorge where vertical permeability in the lower flow regimes may be enhanced.

  12. Solid images generated from UAVs to analyze areas affected by rock falls

    NASA Astrophysics Data System (ADS)

    Giordan, Daniele; Manconi, Andrea; Allasia, Paolo; Baldo, Marco

    2015-04-01

    The study of rock fall affected areas is usually based on the recognition of principal joints families and the localization of potential instable sectors. This requires the acquisition of field data, although as the areas are barely accessible and field inspections are often very dangerous. For this reason, remote sensing systems can be considered as suitable alternative. Recently, Unmanned Aerial Vehicles (UAVs) have been proposed as platform to acquire the necessary information. Indeed, mini UAVs (in particular in the multi-rotors configuration) provide versatility for the acquisition from different points of view a large number of high resolution optical images, which can be used to generate high resolution digital models relevant to the study area. By considering the recent development of powerful user-friendly software and algorithms to process images acquired from UAVs, there is now a need to establish robust methodologies and best-practice guidelines for correct use of 3D models generated in the context of rock fall scenarios. In this work, we show how multi-rotor UAVs can be used to survey areas by rock fall during real emergency contexts. We present two examples of application located in northwestern Italy: the San Germano rock fall (Piemonte region) and the Moneglia rock fall (Liguria region). We acquired data from both terrestrial LiDAR and UAV, in order to compare digital elevation models generated with different remote sensing approaches. We evaluate the volume of the rock falls, identify the areas potentially unstable, and recognize the main joints families. The use on is not so developed but probably this approach can be considered the better solution for a structural investigation of large rock walls. We propose a methodology that jointly considers the Structure from Motion (SfM) approach for the generation of 3D solid images, and a geotechnical analysis for the identification of joint families and potential failure planes.

  13. Using several monitoring techniques to measure the rock mass deformation in the Montserrat Massif

    NASA Astrophysics Data System (ADS)

    Janeras, M.; Jara, J. A.; López, F.; Marturià, J.; Royán, M. J.; Vilaplana, J. M.; Aguasca, A.; Fàbregas, X.; Cabranes, F.; Gili, J. A.

    2015-09-01

    Montserrat Mountain is located near Barcelona in Catalonia, at the north-east corner of Spain, and its massif is formed by conglomerate interleaved by siltstone/sandstone with steep slopes very prone to rock falls. The increasing visitor's number in the monastery area, reaching 2.4 million per year, has pointed out the risk derived from rock falls for this building area and also for the terrestrial accesses, both roads and rack railway. A risk mitigation plan is currently been applied for 2014-2016 that contains monitoring testing and implementation as a key point. The preliminary results of the pilot tests carried out during 2014 are presented, also profiting from previous sparse experiences and data, and combining 4 monitoring techniques under different conditions of continuity in space and time domains, which are: displacement monitoring with Ground-based Synthetic Aperture Radar and characterization at slope scale, with an extremely non uniform atmospheric phase screen because of the stepped topography and atmosphere stratification; Terrestrial Laser Scanner surveys quantifying frequency for unnoticed activity of small rock falls, and monitoring rock block displacements over 1cm; monitoring of rock joints with a wireless net of sensors; and tentative surveying for singular rocky needles with Total Station.

  14. High-resolution rock dilatation measurements from steep bedrock permafrost and implications for rock fall release mechanisms

    NASA Astrophysics Data System (ADS)

    Hasler, Andreas; Gruber, Stephan; Beutel, Jan

    2010-05-01

    In fractured bedrock of steep alpine permafrost rock faces, cleft dynamics, creep and stability of rock masses is influenced by the thermal conditions within and around discontinuities. An increasing number of documented rock falls from periglacial environments in the last decade raise the question, how and where this thermal influence becomes a controlling factor of rock fall activity. The mechanics of permafrost bedrock containing ice-filled clefts has rarely been investigated and only qualitative understanding of the processes interlinking temperature and stability in these situations exist. Here we present temperature, dilatation and translation measurements with high temporal resolution from six clefts at Matterhorn-Hörnligrat (3500m a.s.l.; Swiss Alps). Cleft opening / closing is recorded during cooling / warming at subzero temperatures in the upper cleft. This reversible dilatation is commonly explained by segregation ice formation within the cleft (cryogenic opening). Once temperatures reach the melting point (indicated by a zero curtain in cleft temperature records) an accelerated opening or shearing (depending on the geometrical setting) of the cleft takes place. We attribute this second slow mass movement to a sliding at a basal fracture plane of the rock mass that is introduced by melting conditions. We suspect this sliding mechanism to potentially culminate in the triggering of rock fall or rock avalanches. The response time of the cleft movements to temperature changes is on the order of some hours for both cases (cryogenic opening and sliding). This is surprisingly short for the dimensions of the surveyed rock masses and can not be explained by conductive heat transport between the rock surface and the ice-rock interface within the cleft. Dilatation-temperature plots with the lower cleft temperatures show even a time lag of the cleft temperature in comparison to the movement. This finding is little understood at present but indicates the possible

  15. Rock Slide Monitoring by Using TDR Inclinometers

    NASA Astrophysics Data System (ADS)

    Drusa, Marián; Bulko, Roman

    2016-12-01

    The geotechnical monitoring of the slope deformations is widespread at present time. In many geological localities and civil engineering construction areas, monitoring is a unique tool for controlling of negative factors and processes, also inform us about actual state of rock environment or interacting structures. It is necessary for risk assessment. In our case, geotechnical monitoring is controlling rockslide activity around in the future part of motorway. The construction of new highway route D1 from Bratislava to Košice crosses the territory which is affected by a massive rockslide close to Kraľovany village. There was a need to monitor the activity of a large unstable rockslide with deep shear planes. In this case of underground movement activity, the Department of Geotechnics of the University of Žilina installed inclinometers at the unstable area which worked on Time Domain Reflectometry (TDR) principle. Based on provided measurements, effectivity and suitability of TDR inclinometers for monitoring of deep underground movement activity is demonstrated.

  16. Energy Dissipating Devices in Falling Rock Protection Barriers

    NASA Astrophysics Data System (ADS)

    Castanon-Jano, L.; Blanco-Fernandez, E.; Castro-Fresno, D.; Ballester-Muñoz, F.

    2017-03-01

    Rockfall is a phenomenon which, when uncontrolled, may cause extensive material damage and personal injury. One of the structures used to avoid accidents caused by debris flows or rockfalls is flexible barriers. The energy dissipating devices which absorb the energy generated by rock impact and reduce the mechanical stresses in the rest of the elements of the structure are an essential part of these kinds of structures. This document proposes an overview of the performance of energy dissipating devices, as well as of the role that they fulfil in the barrier. Furthermore, a compilation and a description of the dissipating elements found in the literature are proposed. Additionally, an analysis has been performed of the aspects taken into account in the design, such as experimental (quasi-static and dynamic) tests observing the variation of the behaviour curve depending on the test speed and numerical simulations by means of several finite element software packages.

  17. Rock falls in high-alpine rock walls quantified by terrestrial lidar measurements: A case study in the Mont Blanc area

    NASA Astrophysics Data System (ADS)

    Rabatel, Antoine; Deline, Philip; Jaillet, Stéphane; Ravanel, Ludovic

    2008-05-01

    The global warming observed in recent decades and its future increase may affect permafrost distribution on high-mountain faces with consequences for their stability. In this paper, we show that rock falls from high-alpine rock walls can be computed with a decimetre-resolution using lidar measurements. A laser scanner was used to create point clouds and triangulated irregular network models on the east face of the Tour Ronde at 3792 m asl (Mont Blanc massif). Comparison of the models realised from measurements of July 2005 and July 2006 enabled quantification of rock falls with reduced uncertainty. The volume of rock fall reached a total of 536 m3 in the scanned area, which matches an erosion rate of 8.4 mm yr-1. This rate slightly higher to the ones reported in former studies enable to assume that this rock fall may be the consequence of the permafrost degradation in this rock face.

  18. A Review of Rock Bolt Monitoring Using Smart Sensors.

    PubMed

    Song, Gangbing; Li, Weijie; Wang, Bo; Ho, Siu Chun Michael

    2017-04-05

    Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This work presents a brief introduction on the types of rock bolts followed by a comprehensive review of rock bolt monitoring using smart sensors. Smart sensors that are used to assess rock bolt integrity are reviewed to provide a firm perception of the application of smart sensors for enhanced performance and reliability of rock bolts. The most widely used smart sensors for rock bolt monitoring are the piezoelectric sensors and the fiber optic sensors. The methodologies and principles of these smart sensors are reviewed from the point of view of rock bolt integrity monitoring. The applications of smart sensors in monitoring the critical status of rock bolts, such as the axial force, corrosion occurrence, grout quality and resin delamination, are highlighted. In addition, several prototypes or commercially available smart rock bolt devices are also introduced.

  19. A Review of Rock Bolt Monitoring Using Smart Sensors

    PubMed Central

    Song, Gangbing; Li, Weijie; Wang, Bo; Ho, Siu Chun Michael

    2017-01-01

    Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This work presents a brief introduction on the types of rock bolts followed by a comprehensive review of rock bolt monitoring using smart sensors. Smart sensors that are used to assess rock bolt integrity are reviewed to provide a firm perception of the application of smart sensors for enhanced performance and reliability of rock bolts. The most widely used smart sensors for rock bolt monitoring are the piezoelectric sensors and the fiber optic sensors. The methodologies and principles of these smart sensors are reviewed from the point of view of rock bolt integrity monitoring. The applications of smart sensors in monitoring the critical status of rock bolts, such as the axial force, corrosion occurrence, grout quality and resin delamination, are highlighted. In addition, several prototypes or commercially available smart rock bolt devices are also introduced. PMID:28379167

  20. Rock Burst Monitoring by Integrated Microseismic and Electromagnetic Radiation Methods

    NASA Astrophysics Data System (ADS)

    Li, Xuelong; Wang, Enyuan; Li, Zhonghui; Liu, Zhentang; Song, Dazhao; Qiu, Liming

    2016-11-01

    For this study, microseismic (MS) and electromagnetic radiation (EMR) monitoring systems were installed in a coal mine to monitor rock bursts. The MS system monitors coal or rock mass ruptures in the whole mine, whereas the EMR equipment monitors the coal or rock stress in a small area. By analysing the MS energy, number of MS events, and EMR intensity with respect to rock bursts, it has been shown that the energy and number of MS events present a "quiet period" 1-3 days before the rock burst. The data also show that the EMR intensity reaches a peak before the rock burst and this EMR intensity peak generally corresponds to the MS "quiet period". There is a positive correlation between stress and EMR intensity. Buckling failure of coal or rock depends on the rheological properties and occurs after the peak stress in the high-stress concentration areas in deep mines. The MS "quiet period" before the rock burst is caused by the heterogeneity of the coal and rock structures, the transfer of high stress into internal areas, locked patches, and self-organized criticality near the stress peak. This study increases our understanding of coal and rock instability in deep mines. Combining MS and EMR to monitor rock burst could improve prediction accuracy.

  1. Prediction of rock falls properties thanks to emitted seismic signal.

    NASA Astrophysics Data System (ADS)

    Bachelet, V.; Mangeney, A.; de Rosny, J.; Toussaint, R.; Farin, M.

    2015-12-01

    The seismic signal generated by rockfalls, landslides or avalanches provides an unique tool to detect, characterize and monitor gravitational flow activity, with strong implication in terms of natural hazards. Indeed, as natural flows travel down the slope, they apply stresses on top of the Earth surface, generating seismic waves in a wide frequency band, associated to the different physical processes involved. Our aim is to deduce the granular flow properties from the generated signal. It is addressed here with both laboratory experiments and simulations. In practice, regarding the experimental part, a set-up using a combination of optical and acoustic methods is employed, in order to measure the seismic signal generated by, (i) the impact of beads of different properties, (ii) the collapse of granular columns, over horizontal and sloping substrates. The substrates are made of plates and blocs of different sizes and characteristics. For the first point (i), Farin et al. [2015] have showed that it exists a link between the properties of an impacting bead (mass and velocity) on smooth surfaces and the emitted signal (radiated elastic energy and mean frequency). This demonstrate that it is possible to deduce the impactor properties thanks to the emitted signal. We show here that it is slightly different for rough and erodible surfaces, because of more dissipative processes engaged (friction, grain reorganization, etc). The point (ii) is different from multiple single impacts. We compare experimental situation to a Discrete Elements Method simulation developed by Patrick Richard (IFSTTAR). It computes trajectories of each particle of a granular column collapses, using collisions forces from simplified Hertz's contact model (spring + dashpot) and Verlet's algorithm. We used it to compute synthetic signal generated by the impacts. If the dynamics of beads is well reproduced, waves are different, confirming that "more is different".

  2. Utilization of advanced calibration techniques in stochastic rock fall analysis of quarry slopes

    NASA Astrophysics Data System (ADS)

    Preh, Alexander; Ahmadabadi, Morteza; Kolenprat, Bernd

    2016-04-01

    In order to study rock fall dynamics, a research project was conducted by the Vienna University of Technology and the Austrian Central Labour Inspectorate (Federal Ministry of Labour, Social Affairs and Consumer Protection). A part of this project included 277 full-scale drop tests at three different quarries in Austria and recording key parameters of the rock fall trajectories. The tests involved a total of 277 boulders ranging from 0.18 to 1.8 m in diameter and from 0.009 to 8.1 Mg in mass. The geology of these sites included strong rock belonging to igneous, metamorphic and volcanic types. In this paper the results of the tests are used for calibration and validation a new stochastic computer model. It is demonstrated that the error of the model (i.e. the difference between observed and simulated results) has a lognormal distribution. Selecting two parameters, advanced calibration techniques including Markov Chain Monte Carlo Technique, Maximum Likelihood and Root Mean Square Error (RMSE) are utilized to minimize the error. Validation of the model based on the cross validation technique reveals that in general, reasonable stochastic approximations of the rock fall trajectories are obtained in all dimensions, including runout, bounce heights and velocities. The approximations are compared to the measured data in terms of median, 95% and maximum values. The results of the comparisons indicate that approximate first-order predictions, using a single set of input parameters, are possible and can be used to aid practical hazard and risk assessment.

  3. Rock-fall hazard in the Etruscan archaeological site of Norchia (Central Italy)

    NASA Astrophysics Data System (ADS)

    Margottini, Claudio; Spizzichino, Daniele; Argento, Alessia; Russo, Alfonsina

    2016-04-01

    have allowed the creation of a typical "butte" landscape, later inhabited by Etruscans, are still active. Field survey and historical data collection revealed the presence of many rock slope instabilities that have affected the site. Particularly meaningful is the presence of a large debris fan, just at the toe of the most relevant archaeological place, where the half-cube rock-cut tombs are positioned, testifying important rock-falls after the excavation of the necropolis. The preliminary investigation is revealing the importance of rock-fall hazard as well as the other environmental threats for the future conservation of the site. An integrated approach among different experts is now required, to define processes and causative factors and then to establish priorities for conservation

  4. Recent rock fall activity in the Wetterstein Mountains revealed by a time series of terrestrial laser scans

    NASA Astrophysics Data System (ADS)

    Schöpa, Anne; Baewert, Henning; Cook, Kristen; Morche, David

    2015-04-01

    The north face of the Hochwanner in the Reintal valley, Wetterstein Mountains, southern Germany, has been a site of frequent rock fall activity for the past several hundred years. The so-called 'Steingerümpel' rock fall included an estimated volume of 2.3-2.7 x 106 m3 and led to damming of the Partnach river. This event was dated to 1400-1600 AD. The rock fall left a prominent scar in the rock face where subsequent rock fall activity was concentrated, postulated to be a 'delayed consequence' of the Steingerümpel event. Previous workers used airborne and terrestrial laser scan data to evaluate the volume of the detached material and the deposits on the talus cone at the foot of the slope from the 'delayed consequence' activity between 2006 and 2008 (Heckmann et al., 2012). The largest event during this period was a 5 x 104 m3 rock fall in August 2007. We compared the data of six terrestrial laser scans, which were acquired in June and September 2008, September 2010, June 2011, August 2013, October and November 2014, in order to assess the volumes of detached material after the large rock fall event of 2007. The aim is to investigate the post-event activity at a site of a large rock fall in order to give estimates about the timing when the activity is back to normal conditions in relation to the magnitude of the large event. Although no large rock fall occurred in the observation period, the comparison of the laser scan data indicate that the average rock wall retreat at this site is still higher compared to the mean annual rock wall retreat rate of 0.54 mm/yr for the last millennium in the Reintal valley (Krautblatter et al., 2012). This shows that sites of large rock falls remain active even years after the event. Heckmann, T.; Bimböse, M.; Krautblatter, M.; Haas, F.; Becht, M.; Morche, D. (2012): From geotechnical analysis to quantification and modelling using LiDAR data: a study on rockfall in the Reintal catchment, Bavarian Alps, Germany; Earth Surface

  5. Cryo-induced cracking in high-alpine rock-wall, evidences from acoustic emissions monitoring

    NASA Astrophysics Data System (ADS)

    Amitrano, D.; Gruber, S.; Girard, L.

    2012-04-01

    Ice formation within rock is known to be an important driver of near-surface frost weathering as well as rock damage at the depth of several meters, which may play a crucial role for the slow preconditioning of rock fall in steep permafrost areas. This letter reports results from an experiment where acoustic emission (AE) monitoring was used to investigate rock damage in a high-alpine rock-wall induced by natural thermal cycling and freezing/thawing. The analysis of the large catalog of events obtained shows (i) robust power-law distributions in the time and energy domains, a footprint of rock micro-fracturing activity induced by stresses arising from thermal variations and associated freezing/thawing of rock; (ii) liquid water availability and rock temperature affect AE activity, suggesting the importance of freezing-induced stresses. These results suggest that the framework of further modeling studies (theoretical and numerical) should include damage, elastic interaction and poro-mechanics in order to describe freezing-related stresses.

  6. A custom acoustic emission monitoring system for harsh environments: application to freezing-induced damage in alpine rock-walls

    NASA Astrophysics Data System (ADS)

    Girard, L.; Beutel, J.; Gruber, S.; Hunziker, J.; Lim, R.; Weber, S.

    2012-06-01

    We present a custom acoustic emission (AE) monitoring system designed to perform long-term measurements on high-alpine rock-walls. AE monitoring is a common technique for characterizing damage evolution in solid materials. The system is based on a two-channel AE sensor node (AE-node) integrated into a Wireless Sensor Network (WSN) customized for operation in harsh environments. This wireless architecture offers flexibility in the deployment of AE-nodes at any position of the rock-wall that needs to be monitored, within a range of a few hundred meters from a core station connected to the internet. The system achieves near real-time data delivery and allows the user to remotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock-wall, a special casing was developed. The monitoring system is completed by two probes that measure rock temperature and liquid water content, both probes being also integrated into the WSN. We report a first deployment of the monitoring system on a rock-wall at Jungfraujoch, 3500 m a.s.l., Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the system could serve a number of other applications, including rock-fall hazard surveillance or structural monitoring of concrete structures.

  7. A custom acoustic emission monitoring system for harsh environments: application to freezing-induced damage in alpine rock walls

    NASA Astrophysics Data System (ADS)

    Girard, L.; Beutel, J.; Gruber, S.; Hunziker, J.; Lim, R.; Weber, S.

    2012-11-01

    We present a custom acoustic emission (AE) monitoring system designed to perform long-term measurements on high-alpine rock walls. AE monitoring is a common technique for characterizing damage evolution in solid materials. The system is based on a two-channel AE sensor node (AE-node) integrated into a wireless sensor network (WSN) customized for operation in harsh environments. This wireless architecture offers flexibility in the deployment of AE-nodes at any position of the rock wall that needs to be monitored, within a range of a few hundred meters from a core station connected to the internet. The system achieves near real-time data delivery and allows the user to remotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock wall, a special casing was developed. The monitoring system is completed by two probes that measure rock temperature and liquid water content, both probes being also integrated into the WSN. We report a first deployment of the monitoring system on a rock wall at Jungfraujoch, 3500 m a.s.l., Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the system could serve a number of other applications, including rock fall hazard surveillance or structural monitoring of concrete structures.

  8. Interesting insights into instability of slopes and rock fall in the morphodynamic Himalayan terrane

    NASA Astrophysics Data System (ADS)

    Singh, T. N.; Vishal, V.; Pradhan, S. P.

    2015-12-01

    Himalayan mountain ranges are tectonically and seismically very active and experience many disastrous events with time due to slope failure. Frequent failures of rock cut slopes cause obstruction in traffic and often lead to fatalities. In recent years, the number of tragedies has increased when associated with regional phenomena such at the Kedarnath tragedy of 2013 and the Gorkha earthquake of 2015. The influence of such phenomena on the stability of slopes along important national highways and key settlement areas only raise the risk to lives and property. We conducted a multi-approach investigation for some key slopes along the National Highway 58 in Uttarakhand Himalaya, India. A very detailed field work was conducted to identify the unstable slopes and those with some history of failure. The pertinent geomechanical characteristics of the representative rock samples were determined in the laboratory. Based on the structural data, kinematic analysis was carried out. Finally the slopes were simulated using FDM based simulator, Flac/Slope for analysing the health of the slopes and Rockfall 4.0 to investigate the phenomenon of rockfall along the Highway. It was found that few slopes were weak due to the inherent weak rock materials while few slopes made up of high strength rocks were effectively weak due to prone-to-failure orientation of the joints. Quantification of bounce-height of rock blocks during fall, their energy, velocity and displacement along the slope was also done. Using 3-D simulations, few critically-stable slopes that appear to be stable, were identified. Little ground movement could be capable of triggering a large scale failure in the area. Slopes in the studied region are under threat to failure and need immediate proper planning using the suggested remedial measures.

  9. Falls

    MedlinePlus

    A fall can change your life. If you're elderly, it can lead to disability and a loss of independence. If your bones are fragile from osteoporosis, you could break a bone, often a hip. But aging alone doesn't make people fall. Diabetes and heart disease affect balance. So do ...

  10. FINITE-ELEMENT ANALYSIS OF ROCK FALL ON UNCANISTERED FUEL WASTE PACKAGE DESIGNS (SCPB: N/A)

    SciTech Connect

    Z. Ceylan

    1996-10-18

    The objective of this analysis is to explore the Uncanistered Fuel (UCF) Tube Design waste package (WP) resistance to rock falls. This analysis will also be used to determine the size of rock that can strike the WP without causing failure in the containment barriers from a height based on the starter tunnel dimensions. The purpose of this analysis is to document the models and methods used in the calculations.

  11. Terrestrial LiDAR monitoring of rock slope-channel coupling

    NASA Astrophysics Data System (ADS)

    Bell, R.; Blöthe, J. H.; Meyer, N. K.; Hoffmann, T.; Hoffert, H.; Kreiner, D.; Elverfeldt, K. V.

    2009-04-01

    In steep terrain, various types of landslides (e.g. rock falls, debris flows and slides) are important erosional processes which often have a major impact on fluvial systems. On the one hand, they may divert river channels to opposite slopes or even block entire river channels, leading to the formation of landslide-dammed lakes. On the other hand, rivers prepare or even trigger landslides by undercutting slopes, which again will have an impact on the river channel. Our focus is on two study areas. One of them, the Schlichem Valley, is located in the Swabian Alb (SW-Germany), a lower mountain range consisting of Jurassic sedimentary rocks forming a cuesta landscape. There, the focus is on a larger landslide complex which blocked the river Schlichem three times during the 18th century and which is still active. Recent activity, especially at the location where the landslide enters the fluvial system, is investigated using Terrestrial LiDAR monitoring. The second study area is located in the Gesaeuse National Park in the Austrian Alps. There, various geomorphic environments are investigated by Terrestrial LiDAR including a vertical rock face in Dachstein limestone, which talus slope is directly coupled to the river Enns. The talus slope is built up by rock fall deposits, eroded mainly through smaller debris flow events. Furthermore, the talus slope is undercut by flood events of the river Enns. In this study a concept and first results are presented. They suggest how rock slope processes and their interactions with river channels can be monitored.

  12. Columbia River Channel Improvement Project Rock Removal Blasting: Monitoring Plan

    SciTech Connect

    Carlson, Thomas J.; Johnson, Gary E.

    2010-01-29

    This document provides a monitoring plan to evaluate take as outlined in the National Marine Fisheries Service 2002 Biological Opinion for underwater blasting to remove rock from the navigation channel for the Columbia River Channel Improvement Project. The plan was prepared by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers (USACE), Portland District.

  13. The effect of potential fall distance on hormonal response in rock climbing.

    PubMed

    Baláš, Jiří; Giles, David; Chrastinová, Leona; Kárníková, Kateřina; Kodejška, Jan; Hlaváčková, Alžběta; Vomáčko, Ladislav; Draper, Nick

    2017-05-01

    The aim of this study was to examine the effect of alterations in potential lead fall distance on the hormonal responses of rock climbers. Nine advanced female climbers completed two routes while clipping all (PRO-all) or half (PRO-½) of the fixed points of protection. Venous blood samples were analysed for total catecholamines, noradrenaline (norepinephrine), adrenaline (epinephrine), dopamine, lactate, cortisol and serotonin. Differences between the two conditions pre, immediately post and 15 min post climbing were assessed using a 2 × 3 repeated measures ANOVA. All hormones and blood lactate concentrations increased significantly (P < 0.05) immediately post climb, except for cortisol. Peak cortisol concentrations did not occur until 15 min post ascent. Further, significant interactions between climbing and clipping conditions were found for total catecholamines (890% of basal concentration in PRO-½ vs. 568% in PRO-all), noradrenaline (794% vs. 532%) and dopamine (500% vs. 210%). There were no significant interactions for adrenaline (1920% vs. 1045%), serotonin (150% vs. 127%) or lactate (329% vs. 279%). The study showed a greater catecholamine response with an increase in potential lead fall distance. The most pronounced increases seen in catecholamine concentration were reported for dopamine and noradrenaline.

  14. Geomorphological surveys and software simulations for rock fall hazard assessment: a case study in the Italian Alps

    NASA Astrophysics Data System (ADS)

    Devoto, S.; Boccali, C.; Podda, F.

    2014-12-01

    In northern Italy, fast-moving landslides represent a significant threat to the population and human facilities. In the eastern portion of the Italian Alps, rock falls are recurrent and are often responsible for casualties or severe damage to roads and buildings. The above-cited type of landslide is frequent in mountain ranges, is characterised by strong relief energy and is triggered by earthquakes or copious rainfall, which often exceed 2000 mm yr-1. These factors cause morphological dynamics with intense slope erosion and degradation processes. This work investigates the appraisal of the rock-fall hazard related to the presence of several large unstable blocks located at the top of a limestone peak, approximately 500 m NW with respect to the Village of Cimolais. Field surveys recognised a limestone block exceeding a volume of 400 m3 and identified this block as the most hazardous for Cimolais Village because of its proximity to the rocky cliff. A first assessment of the possible transit and stop areas has been investigated through in-depth traditional activities, such as geomorphological mapping and aerial photo analysis. The output of field surveys was a detailed land use map, which provided a fundamental starting point for rock fall software analysis. The geomorphological observations were correlated with DTMs derived by regional topography and Airborne Laser Scanning (ALS) surveys to recognise possible rock fall routes. To simulate properly rock fall trajectories with a hybrid computer program, particular attention was devoted to the correct quantification of rates of input parameters, such as restitution coefficients and horizontal acceleration associated to earthquakes, which historically occur in this portion of Italy. The simulation outputs regarding the distribution of rock fall end points and kinetic energy along rock falling paths highlight the hazardous situation for Cimolais Village. Because of this reason, mitigation works have been suggested to

  15. Verifying the new luminescence surface-exposure dating technique--rock falls in Canyonlands National Park, Utah

    NASA Astrophysics Data System (ADS)

    Pederson, J. L.; Sohbati, R.; Murray, A. S.; Jain, M.

    2015-12-01

    Recent studies have helped develop the optically stimulated luminescence (OSL) dating of rock surfaces, as applied to the age of the famous Great Gallery rock art panel in Canyonlands National Park. Chapot et al. (2012) dated a key rock fall to ~900 yrs ago by applying OSL to the outer 1-mm buried surface of a sandstone talus boulder, an age confirmed by independent radiocarbon dating. Later, in a novel approach and with the use of a local known-age calibration sample, Sohbati et al. (2012) modelled the millimeter-scale OSL-depth profile to determine a pre-burial exposure duration of ~700 years for the same rock fall. This combination of rock-fall dating and exposure dating--an approach with broad potential to date Holocene mass movements--constrains the creation of the Great Gallery rock art to a time window of 900 to ~1600 years ago (Pederson et al., 2014), a result met with some controversy. Here we report on a new phase of research to verify these results and further refine OSL-profile exposure dating for mass movements. New analyses from within and near the Great Gallery alcove include: i) exposure dating of the same alcove surface upon which the rock art is painted with a predicted exposure age of ~1600 years; ii) exposure dating of the top (light-exposed) side of the same rock-fall boulder whose buried side was previously dated to test for reproduction of the known age; and iii) an improved calibration sample from a nearby trail/road-cut for verification. The residual OSL signal is measured with depth in millimeter-thick increments of all samples. We first determine the site-specific luminescence reduction rate at the rock surface by fitting the OSL surface-exposure dating model to the calibration profile from the trail/road-cut. This parameterized model then provides exposure ages for the bleaching profiles observed in the other samples. Results have implications for the application of OSL rock-surface and exposure-profile dating in other settings where

  16. Synergic use of satellite and ground based remote sensing methods for monitoring the San Leo rock cliff (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Frodella, William; Ciampalini, Andrea; Gigli, Giovanni; Lombardi, Luca; Raspini, Federico; Nocentini, Massimiliano; Scardigli, Cosimo; Casagli, Nicola

    2016-07-01

    The historic town of San Leo (Emilia Romagna Region, northern Italy) is located on top of an isolated rock massif above the Marecchia River valley hillside. On February 27th 2014, a northeastern sector of the massif collapsed; minor structural damages were reported in the town and a few buildings were evacuated as a precautionary measure. Although no fatalities occurred and the San Leo cultural heritage suffered no damage, minor rock fall events kept taking place on the newly formed rock wall, worsening this hazardous situation. In this framework, a monitoring system based on remote sensing techniques, such as radar interferometry (both spaceborne and ground-based) and terrestrial laser scanning, was planned in order to monitor the ground deformation of the investigated area and to evaluate the residual risk. In this paper the main outlines of a 1-year monitoring activity are described, including a pre-event analysis of possible landslide precursors and a post-event analysis of the displacements of both the collapse-affected rock wall sector and the rock fall deposits.

  17. Seismic and gravimetric monitoring of deep creep in rock slopes

    NASA Astrophysics Data System (ADS)

    Brückl, E.; Pregesbauer, M.; Ullrich, C.

    2003-04-01

    Deep creep of rock slopes is frequently observed in high mountain areas. Over a time span of some thousand years many of these slopes developed according the pattern of a "Sackung" and obtained a stable equilibrium at present. However, there are also examples of deep creep changing unexpectedly to a rapid and catastrophic sliding motion. The intention of the seismic and gravimetric monitoring presented here is dedicated to the prediction of this change from deep creep to rapid sliding. During IDNDR several mass movements were investigated in Austria by geodetic (Brunner et. al., 2000), geophysical (Brückl, 2001) and remote sensing methods (Rott et. al., 2000). For the monitoring program we selected two of these rock slopes, which represent deep creep in an active and rather early state (Gradenbach, Carinthia and Hochmais-Atemskopf, Tyrol). Even there is no imminent danger, we cannot exclude a transition to a rapid and catastrophic rock slide for these slopes in future time. The two rock slopes are also monitored by geodetic methods by other organizations. Deep creep in rock slopes is accompanied by the development of cracks and may generate low magnitude earthquakes. The monitoring of these events supplies significant and unique information about the state and process of deep creep. The monitoring time we realized on the two rock slopes (Gradenbach and Hochmais-Atemskopf) comprises a total of 30 d with up to 10 seismic stations. At an average about one event per day was detected and localized. Magnitudes and seismic moments of the events and their pattern in space-time will be shown. Irreversible displacements associated with the seismic events are compared with the displacements measured by geodetic methods and the seismic efficiency is estimated. The ground water level belongs to the most important factors influencing the process of deep creep in rock slopes. Although it can be measured in boreholes, there are good reasons to develop and apply appropriate

  18. Chesapeake Bay Fall Line Toxics Monitoring Program: 1994 final report

    SciTech Connect

    1994-12-31

    The Fall Line Toxics Program for 1994 is a continuation of a long term effort to make accurate load estimates of contaminants entering the Chesapeake Bay from the non-tidal portion of the watershed. This program has identified nine major tributaries on which to make fall line load estimates. The 1994 Fall Line Toxics Program consisted of two components. First, the Susquehanna River was sampled from February 1994 through January 1995 during baseflow and stormflow conditions. Secondly, eight additional tributaries were sampled twice synoptically, once in Spring, 1994 and once in Fall, 1994. This report presents the results of both components. Samples were analyzed for dissolved and particulate fractions of trace elements and organic constituents. Concentration data and extensive quality assurance results are presented.

  19. Rock Island Dam Smolt Monitoring; 1994-1995 Annual Report.

    SciTech Connect

    Truscott, Keith B.; Fielder, Paul C.

    1995-10-01

    Downstream migrating salmon and steelhead trout (Oncorhynchus spp.) smolts were monitored at the Rock Island Dam bypass trap from April 1 - August 31, 1954. This was the tenth consecutive year that the bypass trap was monitored. Data collected included: (1) number of fish caught by species, (2) number of adipose clipped and/or Passive Integrated Transponder (PIT) tagged fish caught by species, (3) daily average riverflow, (4) daily average powerhouse No. 1 and No. 2 flows and daily average spill. These data were transmitted to the Fish Passage Center, which manages the Smolt Monitoring Program throughout the Columbia River Basin. The Smolt Monitoring Program is used to manage the {open_quotes}water budget{close_quotes}, releasing upstream reservoir water storage allocated to supplement river flows to enhance survival of downstream migrating juvenile salmonids. The Rock Island Dam trapping facility collected 37,795 downstream migrating salmonids in 1994. Collected fish included 4 yearling and 4 sub-yearling chinook salmon (O. tshawytscha) that had been previously PIT tagged to help determine migration rates. Additionally, 1,132 sub-yearling chinook, 4,185 yearling chinook, 6,627 steelhead, (O. mykiss) and 422 sockeye (O. nerka) with clipped adipose fins were collected. The middle 80% of the 1994 spring migration (excluding sub-yearling chinooks) passed Rock Island Dam during a 34 day period, April 25 - May 28. Passage rates of chinook and steelhead smolts released from hatcheries and the downstream migration timing of all salmonids are presented. The spring migration timing of juvenile salmonids is strongly influenced by hatchery releases above Rock Island Dam.

  20. Prospective monitoring and self-report of previous falls among older women at high risk of falls and fractures: a study of comparison and agreement

    PubMed Central

    Garcia, Patrícia A.; Dias, João M. D.; Silva, Silvia L. A.; Dias, Rosângela C.

    2015-01-01

    Background: The identification of the occurrence of falls is an important step for screening and for rehabilitation processes for the elderly. The methods of monitoring these events are susceptible to recording biases, and the choice of the most accurate method remains challenging. Objectives: (i) To investigate the agreement between retrospective self-reporting and prospective monitoring of methods of recording falls, and (ii) to compare the retrospective self-reporting of falls and the prospective monitoring of falls and recurrent falls over a 12-month period among older women at high risk of falls and fractures. Method: A total of 118 community-dwelling older women with low bone density were recruited. The incidence of falls was monitored prospectively in 116 older women (2 losses) via monthly phone calls over the course of a year. At the end of this monitoring period, the older women were asked about their recall of falls in the same 12-month period. The agreement between the two methods was analyzed, and the sensitivity and specificity of self-reported previous falls in relation to the prospective monitoring were calculated. Results: There was moderate agreement between the prospective monitoring and the retrospective self-reporting of falls in classifying fallers (Kappa=0.595) and recurrent fallers (Kappa=0.589). The limits of agreement were 0.35±1.66 falls. The self-reporting of prior falls had a 67.2% sensitivity and a 94.2% specificity in classifying fallers among older women and a 50% sensitivity and a 98.9% specificity in classifying recurrent fallers. Conclusion: Self-reporting of falls over a 12-month period underestimated 32.8% of falls and 50% of recurrent falls. The findings recommend caution if one is considering replacing monthly monitoring with annual retrospective questioning. PMID:26083603

  1. Rock Island Dam Smolt Monitoring; 1996 Annual Report.

    SciTech Connect

    McDonald, Robert

    1996-10-01

    Downstream migrating salmon and steelhead (Oncoryhnchus spp.) smolts were monitored at the Rock Island Dam bypass trap from April 1--August 31, 1996. This was the twelfth consecutive year that the bypass trap was monitored. Data collected included: (1) number of fish collected by species, (2) number of fin clipped and/or Passive Integrated Transponder (PIT) tagged fish caught by species, (3) total number of fish showing signs of gas bubble trauma (GBT), (4) percent of descaled fish, and (5) daily average river flow, powerhouse {number_sign}1 flow, powerhouse {number_sign}2 flow and daily average spill. These data were transmitted to the Fish Passage Center (FPC), which manages the Smolt Monitoring Program throughout the Columbia River Basin. The Smolt Monitoring Program is used to manage the water budget, releasing upstream reservoir water storage allocated to supplement river flows during the downstream migration of juvenile salmonids.

  2. Drug-induced falls in older persons: is there a role for therapeutic drug monitoring?

    PubMed Central

    Hartholt, Klaas A.; Becker, Matthijs L.; van der Cammen, Tischa J. M.

    2016-01-01

    Background: Falls are the leading cause of injuries among older persons. Because of ageing societies worldwide, falls are expected to become a prominent public health problem. The usage of several types of drugs has been associated with an increased fall and fracture risk. In order to reduce future falls, preventative measures are needed. Therapeutic drug monitoring may help to identify persons who are at risk for falls due to drug use. The aim was to demonstrate how drugs can contribute to falls and the role of therapeutic drug monitoring. Methods: We present a descriptive case series of four patients. Results: All patients were referred to the geriatric outpatient clinic of a university medical center. The presented cases contained different underlying mechanisms contributing to an increased fall risk in older adults, including renal failure, genetic variation, overdose and ageing. Conclusion/discussion: Older adults are more prone to the side effects of drug use, including falls. Therapeutic drug monitoring may be useful to identify the patients who have an increased drug-related fall risk and to prevent future falls by individualizing the drug regime. PMID:27034772

  3. Long term monitoring of rock surface temperature and rock cracking in temperate and desert climates

    NASA Astrophysics Data System (ADS)

    Eppes, M. C.; Warren, K.; Hinson, E.; Dash, L.

    2012-12-01

    The extent to which diurnal cycling of temperature results in the mechanical breakdown of rock cannot be clearly defined until direct connections between rock surface temperatures and rock cracking are identified under natural conditions. With this goal, we have developed a unique instrumentation system for monitoring spatial (N-, S-, E-, W-, up- and down-facing) and temporal (per minute) temperature variability in natural boulders while simultaneously monitoring cracking via acoustic emission sensors. To date, we have collected 11 and 12 months of data respectively for ~30 cm diameter granite boulders placed in North Carolina (near Charlotte) and New Mexico (Sevilleta National Wildlife Refuge). These data allow us 1) to compare and contrast spatial and temporal trends in surface temperatures of natural boulders at high temporal resolution over unprecedentedly long time scales in two contrasting environments and 2) to make direct correlations between boulder surface temperatures and periods of microcracking as recorded by acoustic emissions in both environments. Preliminary analysis of both data sets indicates that there is no obvious single high or low threshold in surface temperature or rate of surface temperature change (measurable at a per minute scale) beyond which cracking occurs for either locality. For example, for the New Mexico rock, overall rock surface temperatures ranged from -27 C to 54 C throughout the year, and rock surface temperatures during the times of peak cracking event clusters ranged from -14 C to 46 C. The majority of events occur during winter months in North Carolina and in summer in New Mexico. The majority of events occurred in the late afternoon/early evening for both localities, although the overall numbers of cracking events was significantly higher in the New Mexico locality. In both cases, the key temperature factor that appears to most often correlate with cracking is the rate of change of temperature difference across the rock

  4. Anomalous concentrations of seismically triggered rock falls in Pacoima Canyon: Are they caused by highly susceptible slopes or local amplification of seismic shaking?

    USGS Publications Warehouse

    Harp, Edwin L.; Jibson, Randall W.

    2002-01-01

    Anomalously high concentrations of rock falls were triggered in Pacoima Canyon (Los Angeles, California) during the 1994 Northridge earthquake. Similar concentrations were also documented from the 1971 San Fernando earthquake. Using an engineering rock-mass classification that evaluates the susceptibility of rock slopes to seismic failure based on the fracture properties of a rock mass (in terms of a numerical "Q-value" that describes rock quality), the rock slopes in Pacoima Canyon were compared with rock slopes in sorrounding areas where topography and lithology are similar, but rock-fall concentrations from the earthquakes were much lower. A statistical comparison of Q-values from five sites surrounding Pacoima Canyon indicates that seismic susceptibilities are similar to those within Pacoima Canyon; differences in the characteristics of rock slopes between these sites are not sufficient to account for the relatively high concentrations of rock falls within Pacoima Canyon as compared to low concentrations elsewhere. By eliminating susceptibility differences as a cause, the most likely explanations for the differences in rock-fall concentrations is anomalously high shaking levels in Pacoima Canyon, possibly resulting from topographic amplification within the canyon.

  5. Demonstration of a Fractured Rock Geophysical Toolbox (FRGT) for Characterization and Monitoring of DNAPL Biodegradation in Fractured Rock Aquifers

    DTIC Science & Technology

    2016-01-01

    USER’S GUIDE Demonstration of a Fractured Rock Geophysical Toolbox (FRGT) for Characterization and Monitoring of DNAPL Biodegradation in... Fractured Rock Aquifers ESTCP Project ER-201118 JANUARY 2016 F.D. Day-Lewis C.D. Johnson U. S. Geological Survey, Office of Groundwater...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 01/01/2016 Guidance July 2011 - January 2016 Demonstration of a Fractured Rock Geophysical

  6. Chesapeake Bay fall line toxics monitoring program: 1992 interim report

    SciTech Connect

    Dobler, E.; Nemura, A.

    1994-04-01

    The report provides an interim assessment of toxic substance loadings from the fall lines of three major tributaries, Susquehanna, Potomac and James Rivers, to the Chesapeake Bay. Results from the first six months of a one year sampling program conducted from March, 1992 to September, 1992 are described. Loadings are provided for trace metals; synthetic organic compounds; organonitrogen, organophosphorus, and organochlorine pesticides; polychlorinated biphenyl congeners; and polycyclic aromatic hydrocarbons. The program included sampling during both base and storm flow conditions. A key component of the report is the comparison of ultra clean versus standard U.S. Geological Survey protocol collection techniques for trace metals and organics.

  7. Photogrammetry and laser scanning for analyzing slope stability and rock fall runout along the Domodossola-Iselle railway, the Italian Alps

    NASA Astrophysics Data System (ADS)

    Salvini, R.; Francioni, M.; Riccucci, S.; Bonciani, F.; Callegari, I.

    2013-03-01

    In Italy, railways crossing the alpine valleys are a vital means of civil and commercial communications with the rest of Europe. The geomorphologic configuration and the climatic conditions, especially in winter and spring, can cause rock fall events resulting in railway service interruptions and damage to infrastructure and, in the worst case, to people. There were rock fall events at a slope adjacent to the Domodossola-Iselle railway, most recently in 2004. This paper evaluates the stability of a mountain slope and maps rock fall hazards through the modeling of potential runout trajectories. Traditional geological, geomorphological and geo-engineering surveys were combined with data derived from digital terrestrial photogrammetry. Stereo photographic pairs of rocky outcrops in inaccessible areas were acquired from a helicopter. Data from photogrammetry, topographic measurements and laser scanning were then integrated to build a digital model of the slope, to characterize the rock mass and block geometry, and to define possible runout trajectories. The geomatic methods used have yielded oriented stereo-images, orthophotos and precise digital models of rocky wedges. Geometrical and structural characteristics of slopes, such as joint attitude, spacing and persistence, and block volumes, were also derived. The results were used together with a deterministic limit equilibrium method to evaluate slope stability. We assessed the probabilistic distribution of rock fall end points and kinetic energy along the rock falling paths and existing barriers, and created a hazard map based on the spatial distribution of trajectories, rock fall transit density and kinetic energy.

  8. The river and the rocks: The geologic story of Great Falls and the Potomac River Gorge

    USGS Publications Warehouse

    Reed, John Calvin; Sigafoos, Robert Sumner; Fisher, George Wescott

    1980-01-01

    Visitors to Great Falls now number close to a half million annually and, because of this continuing and mounting interest, the U.S. Geological Survey has joined with the National Park Service in preparing this booklet for better understanding and enjoyment of the Great Falls of the Potomac River.

  9. Lateral variations in mylonite zone thickness as influenced by fluid-rock interactions, Linville falls fault, North Carolina

    NASA Astrophysics Data System (ADS)

    Newman, J.; Mitra, G.

    1993-07-01

    Over a distance of approximately 20 km, along strike, the Linville Falls mylonite varies in thickness from 1 m at Linville Falls to >60 m at Banner Elk. Along strike, pressure, temperature and displacement variations are minimized, allowing this study to focus on the influences of fluid behavior and protolith mineralogy on fault zone development. The protolith at Linville Falls contains mainly K-feldspar, perthite and quartz, while at Banner Elk the protolith contains plagioclase and quartz. At Linville Falls, quartz deformed by dynamic recrystallization, feldspar by intragranular fracturing and alteration to quartz and mica, and mica by sliding along cleavage planes. Modal mineralogies change from the protolith to the mylonite with quartz decreasing from 39 to 19% and feldspar from 59 to 1.5%; muscovite increases from <1 to 80%. Mean grain size of the quartz and feldspar also decreased, from 30 to 20 μm and from 110 to 50 μm, respectively. At Banner Elk, deformation occurred predominantly by dynamic recrystallization within the quartz and by sliding along cleavage planes in mica; no feldspar remains within the mylonite zone. Modal mineralogies change from the protolith to the mylonite with quartz and muscovite increasing from 21 to 50% and from < 1 to 44%, respectively. Mean grain size of quartz decreases from 60 to 24 μm. Mass-balance calculations, based on major- and trace-element geochemistry, indicate approximately 75% volume loss at Linville Falls and 20% at Banner Elk. Fluid-rock ratios estimated from the calculated depletions of Si are an order of magnitude higher at Linville Falls than at Banner Elk. Fluids infiltrated the fault zone over a thicker zone at Banner Elk than at Linville Falls because the plagioclase altered more readily than K-feldspar, creating new pathways for fluids. Fluids migrated preferentially through channels along the fault zone, creating a three-dimensional network of higher fluid flow.

  10. 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

  11. Landslides and rock fall processes in the proglacial area of the Gepatsch glacier, Tyrol, Austria - Quantitative assessment of controlling factors and process rates

    NASA Astrophysics Data System (ADS)

    Vehling, Lucas; Rohn, Joachim; Moser, Michael

    2013-04-01

    Due to the rapid deglaciation since 1850, lithological structures and topoclimatic factors, mass movements like rock fall, landslides and complex processes are important contributing factors to sediment transport and modification of the earth's surface in the steep, high mountain catchment of the Gepatsch reservoir. Contemporary geotechnical processes, mass movement deposits, their source areas, and controlling factors like material properties and relief parameters are mapped in the field, on Orthofotos and on digital elevation models. The results are presented in an Arc-Gis based geotechnical map. All mapped mass movements are stored in an Arc-Gis geodatabase and can be queried regarding properties, volume and controlling factors, so that statistical analyses can be conducted. The assessment of rock wall retreat rates is carried out by three different methods in multiple locations, which differ in altitude, exposition, lithology and deglaciation time: Firstly, rock fall processes and rates are investigated in detail on five rock fall collector nets with an overall size of 750 m2. Rock fall particles are gathered, weighed and grain size distribution is detected by sieving and measuring the diameter of the particles to distinct between rock fall processes and magnitudes. Rock wall erosion processes like joint formation and expansions are measured with high temporal resolution by electrical crack meters, together with rock- and air temperature. Secondly, in cooperation with the other working groups in the PROSA project, rock fall volumes are determined with multitemporal terrestrial laserscanning from several locations. Lately, already triggered rock falls are accounted by mapping the volume of the deposit and calculating of the bedrock source area. The deposition time span is fixed by consideration of the late Holocene lateral moraines and analysing historical aerial photographs, so that longer term rock wall retreat rates can be calculated. In order to limit

  12. Embedded fall and activity monitoring for a wearable ambient assisted living solution for older adults.

    PubMed

    Bourke, Alan K; Prescher, Sandra; Koehler, Friedrich; Cionca, Victor; Tavares, Carlos; Gomis, Sergi; Garcia, Virginia; Nelson, John

    2012-01-01

    With the rapidly increasing over 60 and over 80 age groups in society, greater emphasis will be put on technology to detect emergency situations, such as falls, in order to promote independent living. This paper describes the development and deployment of fall-detection, activity classification and energy expenditure algorithms, deployed in a tele-monitoring system. These algorithms were successfully tested in an end-user trial involving 9 elderly volunteers using the system for 28 days.

  13. Active and passive seismic methods for characterization and monitoring of unstable rock masses: field surveys, laboratory tests and modeling.

    NASA Astrophysics Data System (ADS)

    Colombero, Chiara; Baillet, Laurent; Comina, Cesare; Jongmans, Denis; Vinciguerra, Sergio

    2016-04-01

    Appropriate characterization and monitoring of potentially unstable rock masses may provide a better knowledge of the active processes and help to forecast the evolution to failure. Among the available geophysical methods, active seismic surveys are often suitable to infer the internal structure and the fracturing conditions of the unstable body. For monitoring purposes, although remote-sensing techniques and in-situ geotechnical measurements are successfully tested on landslides, they may not be suitable to early forecast sudden rapid rockslides. Passive seismic monitoring can help for this purpose. Detection, classification and localization of microseismic events within the prone-to-fall rock mass can provide information about the incipient failure of internal rock bridges. Acceleration to failure can be detected from an increasing microseismic event rate. The latter can be compared with meteorological data to understand the external factors controlling stability. On the other hand, seismic noise recorded on prone-to-fall rock slopes shows that the temporal variations in spectral content and correlation of ambient vibrations can be related to both reversible and irreversible changes within the rock mass. We present the results of the active and passive seismic data acquired at the potentially unstable granitic cliff of Madonna del Sasso (NW Italy). Down-hole tests, surface refraction and cross-hole tomography were carried out for the characterization of the fracturing state of the site. Field surveys were implemented with laboratory determination of physico-mechanical properties on rock samples and measurements of the ultrasonic pulse velocity. This multi-scale approach led to a lithological interpretation of the seismic velocity field obtained at the site and to a systematic correlation of the measured velocities with physical properties (density and porosity) and macroscopic features of the granitic cliff (fracturing, weathering and anisotropy). Continuous

  14. Monitoring Fluid Flow in Fractured Carbonate Rocks Using Seismic Measurements

    NASA Astrophysics Data System (ADS)

    Li, W.; Pyrak-Nolte, L. J.

    2008-12-01

    The physical properties of carbonate rock are strongly influenced by the rock fabric which depends on the depositional environment, diagenetic and tectonic processes. The most common form of heterogeneity is layering caused by a variation in porosity among layers and within layers. The variation in porosity among layers leads to anisotropic behavior in the hydraulic, mechanical and seismic properties of carbonate rocks. We present the results of a laboratory study to examine the effect of fabric-controlled layering on fluid flow and seismic wave propagation through intact and fractured carbonate rock. Experiments were performed on cubic samples of Austin Chalk Cordova Cream. Samples AC1, AC5 and AC6 are cubic samples that measure 100 mm on edge. The samples were sealed and contained three inlet and three outlet ports for fluid invasion experiments. Two orthogonal seismic arrays were used to record both compressional and shear wave transmission through intact and fractured samples. The arrays used piezoelectric contact transducers with a central frequency 1.0 MHz. Between the two arrays, sixteen sources and sixteen receivers were used. Seismic measurements were made on the samples as a function of stress and during fluid saturation. The location of the invading fluid front as a function of time was monitored by using the peak-to-peak amplitude of the transmitted signals. The front was assumed to be between a source-receiver pair when the signal amplitude decreased by 50% over the initial value. The hydraulic gradient was parallel and perpendicular to the layers for AC5 and AC6, respectively. Sample AC1 was fractured and flow ports were established on the edges of the fracture plane. The weakly directed fabric controlled the rate at which fluid flowed through the samples. From the seismic data on AC6, the fluid first spread vertically along a layer before flowing across the layers. For AC6, it took the fluid two and half hours to flow between the inlet and the outlet

  15. Unmanned Aerial Systems and DSM matching for rock glacier monitoring

    NASA Astrophysics Data System (ADS)

    Dall'Asta, Elisa; Forlani, Gianfranco; Roncella, Riccardo; Santise, Marina; Diotri, Fabrizio; Morra di Cella, Umberto

    2017-05-01

    Among other techniques, aerial and terrestrial photogrammetry have long been used to control the displacements of landslides and glaciers as well as for the detection of terrain morphological changes. Unmanned Aerial Systems (UAS) are today an efficient tool to perform data acquisition in rough or difficult terrain, both safely and quickly, avoiding hazards and risks for the operators while at the same time containing the survey costs. Since 2012 ARPAVdA (the Regional Environmental Protection Agency of Aosta Valley, Italy) periodically surveys with UAS photogrammetry the Gran Sometta rock glacier, the Agency main monitoring site for the climate change impacts on high-mountain areas and related infrastructures. A Digital Surface Model (DSM) and an orthophoto of the rock glacier are produced after each survey flight. In order to accurately georeference them in a stable reference system, a Global Navigation Satellite System (GNSS) campaign is carried out at each epoch, to update the coordinates of signalised Ground Control Points (GCPs), since they partly lay in unstable (moving) areas. In late August 2015 a survey flight has been executed with a senseFly eBee RTK, with differential corrections sent from a ground reference station. The block has been adjusted without GCP using, as control information, only the projection centres coordinates encoded in the images. The RMS of the differences found on twelve Check Points were about 4 cm in horizontal and 7 cm in elevation, i.e. practically the same accuracy found using GCP. Differences between the DSMs produced at the same epoch with block orientation performed with GCP and with GNSS-determined projection centres were also investigated. To evaluate the rock glacier displacement fields between two epochs, corresponding features were at first manually identified on the orthophotos by a trained operator. To avoid the manual time-consuming procedure and increase the density of displacement information, two automatic

  16. Development of novel algorithm and real-time monitoring ambulatory system using Bluetooth module for fall detection in the elderly.

    PubMed

    Hwang, J Y; Kang, J M; Jang, Y W; Kim, H

    2004-01-01

    Novel algorithm and real-time ambulatory monitoring system for fall detection in elderly people is described. Our system is comprised of accelerometer, tilt sensor and gyroscope. For real-time monitoring, we used Bluetooth. Accelerometer measures kinetic force, tilt sensor and gyroscope estimates body posture. Also, we suggested algorithm using signals which obtained from the system attached to the chest for fall detection. To evaluate our system and algorithm, we experimented on three people aged over 26 years. The experiment of four cases such as forward fall, backward fall, side fall and sit-stand was repeated ten times and the experiment in daily life activity was performed one time to each subject. These experiments showed that our system and algorithm could distinguish between falling and daily life activity. Moreover, the accuracy of fall detection is 96.7%. Our system is especially adapted for long-time and real-time ambulatory monitoring of elderly people in emergency situation.

  17. Drop attacks, falls and atonic seizures in the Video-EEG monitoring unit.

    PubMed

    Baraldi, Sara; Farrell, Fiona; Benson, Jennifer; Diehl, Beate; Wehner, Tim; Kovac, Stjepana

    2015-11-01

    We set out to determine clinical and EEG features of seizures presenting with falls, epileptic drop attacks and atonia in the video EEG monitoring unit. We searched the video EEG monitoring reports over a 5-year-period for the terms "drop", "fall" and "atonic". Seizures presenting as epileptic drop attacks, falls or atonia were found in 23/1112 (2%) admissions. About half of the patients suffering from these seizure types had developmental delay and learning difficulties and in half of the patients a lesion was seen on MRI which was often frontal. The presumed epileptogenic zone was frontal in many cases (43%), unclear with regards to a region or multifocal in 48% and posterior temporal/occipital in 2 patients (9%). EEG patterns recorded were paroxysmal fast activity, spike and wave discharges and EEG attenuation. Seizure related falls were seen in 8 cases (34%) with injuries recorded during Video EEG monitoring in half of those. Clinical and EEG features outlined here can help the clinician to recognise patients at risk for these devastating seizure types. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  18. Fracture of the lateral tubercle of the posterior talar process caused by a rock-climbing fall: a case report.

    PubMed

    Blanchette, Marc-André; Grenier, Julie-Marthe

    2014-09-01

    The purpose of this case report is to describe the clinical presentation of a patient who suffered from a fracture of the lateral tubercle of the posterior talar process caused by a fall while rock-climbing. The initial evaluation revealed diffuse ankle swelling, tenderness, and pain at the distal aspect of both malleoli. Plain film radiography revealed a fracture of the posterior process of the talus. Computed tomography (CT) outlined the extension of the fracture line in the postero-lateral aspect of the body of the talus with minimal displacement. The patient was treated conservatively with an Aircast© walking boot for 6 weeks (non-weight-bearing) followed by a 2-week period of partial weight bearing. At the 8 week follow-up, he reported minimal tenderness and normal ankle function. Clinicians should be aware that talar fracture identification on plain films is difficult and computed tomography or magnetic resonance imaging may be required.

  19. Independent Analysis of Seismicity and Rock fall Scenarios for the Yucca Mountain Repository

    SciTech Connect

    Apted, M.J.; Kemeny, J.M.; Martin, C.D.; James, R.J.

    2006-07-01

    Yucca Mountain is located in the somewhat seismically active Basin and Range province. Future seismic activity is identified by the US Nuclear Regulatory Commission and the US National Academy of Sciences as a key scenario for safety assessment of a proposed repository at Yucca Mountain. As part of its on-going program of conducting independent analyses of scientific and technical issues that could be important to the licensing of the Yucca Mountain repository, EPRI has conducted an analysis of the combined scenarios of seismic activity and stability of emplacement drifts with respect to the long-term repository safety. In this paper we present the results of 3D finite element simulations of both static and dynamic loading of a degraded waste package. For the static case, the expected maximum static load is determined by utilizing relationships between cave height and the bulking factor. A static load representing 30 meters of broken rock was simulated using the finite element model. For the dynamic case, block size and velocity data from the most recent Drift Degradation AMR are used. Based on this, a rock block with a volume of 3.11 m{sup 3} and with an impact velocity of 4.81 m/s was simulated using the finite element model. In both cases, the results indicate that the waste package remains intact. (authors)

  20. SCOPING EVALUATION TO EXPLORE - ROCK FALL ACCIDENT CONDITION ANALYSIS ON MULTI-PURPOSE CANISTER WASTE PACKAGES CORRELATED FROM INTERLOCKING BASKET WASTE PACKAGE DESIGN ANALYSIS (SCPB: N/A)

    SciTech Connect

    Z, Ceylan

    1995-12-08

    The objective of this analysis is to correlate the results of a rock fall analysis performed for the 12 Pressurized Water Reactor (PWR) Fuel Assembly Interlocking Basket waste package (WP) in order to determine the size of rock that can strike the Multi-Purpose Canister (MPC) waste packages without breaching the containment barriers. The purpose of this analysis is to document the models and methods used in the calculations.

  1. Assessment of bioavailable hydrocarbons in Pribilof Island rock sandpiper fall staging areas and overwintering habitat.

    PubMed

    Nesvacil, Kelly; Carls, Mark; Holland, Larry; Wright, Sadie

    2016-09-15

    At present, significant adverse hydrocarbon influence on the Pribilof Island rock sandpiper (Calidris ptilocnemis ptilocnemis) is unlikely. Almost the entire population overwinters in Cook Inlet and breeds on four Bering Sea islands. Passive samplers deployed several times in a three year period and corresponding sediment and soft tissue samples on St. Paul Island and in Cook Inlet generally accumulated small quantities of polycyclic aromatic hydrocarbons (PAHs). Composition was consistent with oil in <15% of the passive samplers and rarely in soft tissue. Total PAH concentrations in corresponding sediment were very low (<42ng/g dry weight); composition was consistent with oil in 39% of these samples and biomarker composition confirmed this on St. Paul Island. However, composition was dominated by normal alkanes from natural sources. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Wireless patch sensor for remote monitoring of heart rate, respiration, activity, and falls.

    PubMed

    Chan, Alexander M; Selvaraj, Nandakumar; Ferdosi, Nima; Narasimhan, Ravi

    2013-01-01

    Unobtrusive continuous monitoring of important vital signs and activity metrics has the potential to provide remote health monitoring, at-home screening, and rapid notification of critical events such as heart attacks, falls, or respiratory distress. This paper contains validation results of a wireless Bluetooth Low Energy (BLE) patch sensor consisting of two electrocardiography (ECG) electrodes, a microcontroller, a tri-axial accelerometer, and a BLE transceiver. The sensor measures heart rate, heart rate variability (HRV), respiratory rate, posture, steps, and falls and was evaluated on a total of 25 adult participants who performed breathing exercises, activities of daily living (ADLs), various stretches, stationary cycling, walking/running, and simulated falls. Compared to reference devices, the heart rate measurement had a mean absolute error (MAE) of less than 2 bpm, time-domain HRV measurements had an RMS error of less than 15 ms, respiratory rate had an MAE of 1.1 breaths per minute during metronome breathing, posture detection had an accuracy of over 95% in two of the three patch locations, steps were counted with an absolute error of less than 5%, and falls were detected with a sensitivity of 95.2% and specificity of 100%.

  3. A system for ubiquitous fall monitoring at home via a wireless sensor network.

    PubMed

    Fernandez-Luque, Francisco J; Zapata, Juan; Ruiz, Ramon

    2010-01-01

    Accidental falls of our elderly, and physical injuries resulting, represent a major health and economic. Falls are the most common causes of serious injuries and a major health threats in the stratum of older population. Early detection of a fall is a key factor when trying to provide adequate care to the elderly person who has suffered an accident at home. In this paper, we present a support system for detecting falls of an elder person by a static wireless nonintrusive sensorial infrastructure based on heterogenous sensor nodes. This previous infrastructure, named AID (Alarm Intelligent Device), is an AAL (Ambient Assisted Living) system that allows to infer a potential fall. We have developed, different to other contributions, a specific low-power multi-hop network consists of nodes (Motes) that wirelessly communicate to each other and are capable of hopping radio messages to a base station where they are passed to a PC (or other possible client). The goal of this project is 1) to provide alerts to caregivers in the event of an accident, acute illness or strange (possibly dangerous) activities, and 2) to enable that authorized and authenticated caregivers by means of a itinerant wearable mote can be inserted into mesh and interact with it. In this paper, we describe an ubiquitous assistential monitoring system at home.

  4. Rocks.

    ERIC Educational Resources Information Center

    Lee, Alice

    This science unit is designed for limited- and non-English speaking students in a Chinese bilingual education program. The unit covers rock material, classification, characteristics of types of rocks, and rock cycles. It is written in Chinese and simple English. At the end of the unit there is a list of main terms in both English and Chinese, and…

  5. Mountain permafrost and recent Alpine rock-fall events: a GIS-based approach to determine critical factors and runout zones

    NASA Astrophysics Data System (ADS)

    Noetzli, J.; Hoelzle, M.; Haeberli, W.:

    2003-04-01

    Glacier retreat and permafrost changes, as related to climate change, are supposed to affect stability conditions of steep rock walls in cold mountain ranges. Several rock-fall events that have occurred in the European Alps during the 20th century (for example, the Brenva Glacier rock avalanches of 1920 and 1997 in the Aosta Valley or the recently developed instability in the Monte-Rosa east wall in the Anzasca Valley, both in the Italian Alps) are possibly related to warm permafrost. The presence of unfrozen water in partially ice-filled bedrock fissures is likely to lead to reduced shearing resistance. However, available knowledge about thermal, topographic and geological conditions under which such instabilities develop remains limited and needs quantitative investigation. Corresponding data can be used as a basis for GIS-based spatial modeling of critical factors or of combinations of factors. Such spatial models of critical rock-fall factors then serve as a basis for assessing hazard potentials that may evolve from periglacial rock falls in case of continued or even accelerated atmospheric temperature rise. In order to proceed into this direction, parameters are determined in a systematic study of known rock-fall events in the Alps. Surface temperatures of historically documented starting zones are estimated either by applying the ärules of thumb“ earlier developed for the Swiss Alps, by applying GIS-based spatial models such as PERMAMAP or by using the data of a 2001/2002 rock-temperature measurement campaign. Topographic factors such as slope, altitude or aspect are derived from DTMs. Altitude difference, length, overall slope and surface characteristics (glacier, moraines, turns etc.) of runout paths are also inventoried. Despite the relatively small number of events documented (around 20), first results can be given and first model runs of spatial patterns and potential runout zones can be presented from a selected test area in the Valais Alps

  6. Rock fall generated seismic signal at the laboratory scale: impact of the nature of the substrate

    NASA Astrophysics Data System (ADS)

    Bachelet, V.; Mangeney, A.; de Rosny, J.; Toussaint, R.; Farin, M.

    2016-12-01

    The seismic signal generated by rockfalls, landslides or avalanches is a unique tool to detect, characterize and monitor gravitational flow activity, with strong implication in terms of natural hazard monitoring. Farin et al. [2015] have shown, theoretically and experimentally, that the properties of an impacting bead (mass and velocity) on smooth surfaces can be recovered from the emitted signal (radiated elastic energy and mean frequency). In this work, we extend this study to rough and erodible surfaces. We dropped steel and glass beads of diameter between 2 and 10 mm, from 10 to 30 cm heights on (i) a smooth PMMA plate, (ii) a rough plate with 3mm-diameter glass beads glued on its surface, and (iii) erodible beds made by adding layers of free beads on the rough plate. The characteristics of the acoustic signal (frequency, energy) generated during the impact is measured thanks to 8 accelerometers (fe = 100kHz) and the bead motion characteristics (kinetic energy lost, bounce angle) is monitored using both these accelerometers and stereoscopy view captured by 2 fast cameras (fe = 500Hz). First, we confirm that the Hertz model well describes the source of generated acoustic waves during bead impacts on smooth surfaces. Then, we establish phenomenologically the link between impacting beads properties and emitted seismic signal for rough and erodible beds. We also quantify the fluctuations of the elastic energy and of the mean frequency in our experiments. Finally, we show that bounce angle actually drives conversion from kinetic energy of the impacting bead into radiated elastic energy.

  7. Real-Time Constant Monitoring of Fall Risk Index by Means of Fully-Wireless Insoles.

    PubMed

    Arndt, Holger; Burkard, Stefan; Talavera, Guillermo; Garcia, Joan; Castells, David; Codina, Marc; Hausdorff, Jeffrey; Mirelman, Anat; Harte, Richard; Casey, Monica; Glynn, Liam; Di Rosa, Mirko; Rossi, Lorena; Stara, Vera; Rösevall, John; Rusu, Cristina; Carenas, Carlos; Breuil, Fanny; Reixach, Elisenda; Carrabina, Jordi

    2017-01-01

    Constant monitoring of gait in real life conditions is considered the best way to assess Fall Risk Index (FRI) since most falls happen out of the ideal conditions in which clinicians are currently analyzing the patient's behavior. This paper presents the WIISEL platform and results obtained through the use of the first full-wireless insole devices that can measure almost all gait related data directly on the feet (not in the upper part of the body as most existing wearable solutions). The platform consists of a complete tool-chain: insoles, smartphone & app, server & analysis tool, FRI estimation and user access. Results are obtained by combining parameters in a personalized way to build individual fall risk index assessed by experts with the help of data analytics. New FRI has been compared with standards that validate the quality of its prediction in a statistically significant way. That qualitatively relevant information is being provided to the platform users, being either end-users/patients, relatives or caregivers and the related clinicians to ideally assess about their long term evolution.

  8. Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks

    PubMed Central

    Yang, Yaowen; Annamdas, Venu Gopal Madhav; Wang, Chao; Zhou, Yingxin

    2008-01-01

    Reliable structural health monitoring (SHM) including nondestructive evaluation (NDE) is essential for safe operation of infrastructure systems. Effective monitoring of the rock components of civil infrastructures such as tunnels and caverns remains challenging. The feasibility of employing smart optical fibre sensor (OFS) and piezoelectric impedance sensor made up of lead zirconate titanate (PZT) for comprehensive health monitoring of rocks, covering load history monitoring/retrieval as well as damage assessment is presented in this paper. The rock specimens are subjected to cyclic loading and their conditions are continuously monitored using OFS and PZT sensors. OFS based multiplexed fibre Bragg grating (FBG) sensors are surface bonded on the rock specimens. Their strain sensing performance is compared with the conventional electric strain gauges (ESGs). In addition, PZT patches are also bonded on the specimens to study the damage pattern during different loading cycles. Unlike the FBGs or ESGs, PZT patches are used as bi-functional sensors and actuators, enabling them to be efficient detectors of incipient damages using the principle of electromechanical impedance. The experimental study demonstrated superior performance of these smart FBG and PZT impedance sensors. This work is expected to be useful for SHM based NDE application of rock structures such as caverns and tunnels. PMID:27879708

  9. Niagara Falls Storage Site annual site environmental monitoring report. Calendar year 1985

    SciTech Connect

    Not Available

    1986-04-01

    During 1985, an environmental monitoring program was continued at the Niagara Falls Storage Site (NFSS), a United States Department of Energy (DOE) surplus facility located in Niagara County, New York, presently used for the interim storage of low-level radioactive residues and contaminated soils and rubble. The monitoring program is being conducted by Bechtel National, Inc. Monitoring results show that the NFSS is in compliance with DOE concentration guides and radiation protection standards. Derived Concentration Guides (DCGs) represent the concentrations of radionuclides in air or water that would limit the radiation dose to 100 mrem/yr. The applicable limits have been revised since the 1984 environmental monitoring report was published. The limits applied in 1984 were based on a radiation protection standard of 500 mrem/yr; the limits applied for the 1985 are based on a standard of 100 mrem/yr. To determine whether the site is in compliance with DOE standards, environmental measurements are expressed as percentages of the applicable DCG, while the calculated doses to the public are expressed as percentages of the applicable radiation protection standard. The monitoring program measured radon gas concentrations in air; uranium and radium concentrations in surface water, groundwater, and sediments; and external gamma dose rates. Environmental samples collected were analyzed to determine compliance with applicable standards. Potential radiation doses to the public were also calculated.

  10. ATLAS: Forecasting Falling Rocks

    NASA Astrophysics Data System (ADS)

    Heinze, Aren; Tonry, John L.; Denneau, Larry; Stalder, Brian; Sherstyuk, Andrei

    2016-10-01

    The Asteroid Terrestrial-impact Last Alert System (ATLAS) is a new asteroid survey aimed at detecting small (10-100 meter) asteroids inbound for impact with Earth. Relative to the larger objects targeted by most surveys, these small asteroids pose very different threats to our planet. Large asteroids can be seen at great distances and measured over many years, resulting in precise orbits that enable long-term impact predictions. If an impact were predicted, a costly deflection mission would be warranted to avert global catastrophe -- but a large asteroid impact is very unlikely in the next century. By contrast, impacts from small asteroids are inevitable. Such objects can be detected only during close encounters with Earth -- encounters too brief to yield long-term predictions. Only a few days' warning could be expected for an impactor in the 10-100 meter range, but fortunately the impact of such an asteroid would cause only regional damage. As in the case of a hurricane, a quixotic attempt to deflect or destroy it would be more expensive than the damage from its impact. A better response is to save human lives by evacuating the impact zone, and then rebuild. Only a few days warning are needed for this purpose, and ATLAS is unique among asteroid surveys in being optimized to provide it. While the optimization has many facets, the most important is rapidly surveying the entire accessible sky. A small asteroid could come from any direction and go from invisibility to impact in less than a week: ATLAS must look everywhere, all the time. Sky coverage is more important than exquisite sensitivity to faint objects, because asteroids inbound for impact will eventually become quite bright. This makes ATLAS complementary to other surveys, which scan the sky at a more leisurely pace but are able to detect asteroids at greater distances. We report on ATLAS' first year of survey operations, including the maturing of robotic observation and detection strategies, and asteroid and comet discoveries both expected and unexpected.

  11. Rapid large- and site scale RPAS mission planning for remote sensing of rock falls and landslides in alpine areas

    NASA Astrophysics Data System (ADS)

    Gräupl, Thomas; Pschernig, Elias; Rokitansky, Carl-Herbert; Oleire-Oltmanns, Sebastian; Zobl, Fritz

    2014-05-01

    Since landslides and rock falls are complex phenomena involving a multitude of factors, current and historic surface data play besides geologic conditions and others an important role in analyzing hazard situation and efficient site-specific remediation actions. Especially in displacement acceleration phases which are frequently linked to bad weather conditions, data acquisition remains difficult. Therefore RPAS with their small ground sampling distance and correspondingly high resolution open up possibilities for surveying ground situations not only for visual inspection but also for geodetic data acquisition. Both, visual and geodetic data provide valuable information for geologists and related decision makers. Slides or rock falls in alpine areas pose special challenges due to mostly acute and unforeseen displacements on the one hand and geographic conditions of narrow valleys along with steep slopes on the other hand. Rapid RPAS mission planning and mission adaption for individual requirements according to different project stages (initial investigation, repeat measurements, identification of hazard zones for urgent remediation actions, etc.) is therefore of particular importance. Here we present a computer-simulation supported approach to RPAS mission planning taking the identified thematic and remote sensing targets, the relevant terrain and obstacle databases, legal restrictions, aircraft performance, sensor characteristics, and communication ranges into account in order to produce a safe and mission-optimized flight route. For the RPAS mission planning, we combine and adapt tools developed at University of Salzburg, namely a flight track generator taking into account a 3D-model of the earth surface with both, focus on large area coverage (e.g. Austria) and the highest available resolution (e.g. sub-meter for specific areas), available obstacle data bases for the mission area (e.g. cable car lines, power lines, buildings, slope stabilization constructions

  12. Time domain reflectometry as a rock mass monitoring technique

    SciTech Connect

    Francke, J.L.; Terrill, L.J.; Allen, W.W.

    1996-06-01

    This paper describes the practices and methods used in a study of Time Domain Reflectometry (TDR) as an inexpensive deformation monitoring tool in underground excavations at the Waste Isolation Pilot Plant (WIPP). The WIPP is being developed near Carlsbad, New Mexico, for the disposal of transuranic nuclear wastes in bedded salt 655 m (2150 ft) below the surface. Data collected from WIPP geomechanical monitoring are used to characterize conditions, confirm design assumptions, and understand and predict the performance of the deep salt excavation. The geomechanical monitoring techniques ranging from inspection of observation boreholes to advanced radar surveys. In 1989 TDR was introduced as a monitoring tool with the installation of 12.7 mm (0.5 in) diameter TDR cables in the underground excavations. In 1993, a new TDR system was installed in a separate location. Based on experience with the previous installation, enhancements were implemented into the new TDR system that: (1) extended the period of performance by increasing cable diameter to 22. 2 mm (0.875 in), (2) increased accuracy in locating areas of deformation by aligning cables with nearby observation boreholes, and (3) improved data acquisition and analyses using a standard laptop computer, eliminating the chart recorder previously used. In summary, the results of a correlation between the TDR signatures to nearby observation boreholes and geomechanical instrumentation will be presented.

  13. Use of Aerial Photography to Monitor Fall Chinook Salmon Spawning in the Columbia River

    SciTech Connect

    Visser, Richard H.; Dauble, Dennis D. ); Geist, David R. )

    2002-11-01

    This paper compares two methods for enumerating salmon redds and their application to monitoring spawning activity. Aerial photographs of fall chinook salmon spawning areas in the Hanford Reach of the Columbia River were digitized and mapped using Geographic Information Systems (GIS) techniques in 1994 and 1995 as part of an annual assessment of the population. The number of visible redds from these photographs were compared to counts obtained from visual surveys with fixed wing aircraft. The proportion of the total redds within each of five general survey areas was similar for the two monitoring techniques. However, the total number of redds based on aerial photographs was 2.2 and 3.0 times higher than those observed during visual surveys for 1994 and 1995, respectively. The divergence in redd counts was most evident near peak spawning activity when the number of redds within individual spawning clusters exceeded 500. Aerial photography improved our ability to monitor numbers of visible salmon redds and to quantify habitat use.

  14. Fully Autonomous Multiplet Event Detection: Application to Local-Distance Monitoring of Blood Falls Seismicity

    SciTech Connect

    Carmichael, Joshua Daniel; Carr, Christina; Pettit, Erin C.

    2015-06-18

    We apply a fully autonomous icequake detection methodology to a single day of high-sample rate (200 Hz) seismic network data recorded from the terminus of Taylor Glacier, ANT that temporally coincided with a brine release episode near Blood Falls (May 13, 2014). We demonstrate a statistically validated procedure to assemble waveforms triggered by icequakes into populations of clusters linked by intra-event waveform similarity. Our processing methodology implements a noise-adaptive power detector coupled with a complete-linkage clustering algorithm and noise-adaptive correlation detector. This detector-chain reveals a population of 20 multiplet sequences that includes ~150 icequakes and produces zero false alarms on the concurrent, diurnally variable noise. Our results are very promising for identifying changes in background seismicity associated with the presence or absence of brine release episodes. We thereby suggest that our methodology could be applied to longer time periods to establish a brine-release monitoring program for Blood Falls that is based on icequake detections.

  15. Seismic monitoring of heavy oil reservoirs: Rock physics and finite element modelling

    NASA Astrophysics Data System (ADS)

    Theune, Ulrich

    In the past decades, remote monitoring of subsurface processes has attracted increasing attention in geophysics. With repeated geophysical surveys one attempts to detect changes in the physical properties in the underground without directly accessing the earth. This technique has been proven to be very valuable for monitoring enhanced oil recovery programs. This thesis presents an modelling approach for the feasibility analysis for monitoring of a thermal enhanced oil recovery technique applied to heavy oil reservoirs in the Western Canadian Sedimentary Basin. In order to produce heavy oil from shallow reservoirs thermal oil recovery techniques such as the Steam Assisted Gravity Drainage (SAGD) are often employed. As these techniques are expensive and technically challenging, early detection of operational problems is without doubt of great value. However, the feasibility of geophysical monitoring depends on many factors such as the changes in the rock physical properties of the target reservoir. In order to access the feasibility of seismic monitoring for heavy oil reservoirs, a fluid-substitutional rock physical study has been carried out to simulate the steam injection. The second modelling approach is based on a modified finite element algorithm to simulate the propagation of elastic waves in the earth, which has been developed independently in the framework of this thesis. The work summarized in this thesis shows a possibility to access the feasibility of seismic monitoring for heavy oil reservoirs through an extensive rock-physical study. Seismic monitoring is a useful tool in reservoir management decision process. However, the work reported here suggests that seismic monitoring of SAGD processes in the heavy oil reservoirs of the Western Canadian Sedimentary Basin is only feasible in shallow, unconsolidated deposits. For deeper, but otherwise geological similar reservoirs, the SAGD does not create a sufficient change in the rock physical properties to be

  16. SeisRockHT - Seismic Rockfall Monitoring in the Hohe Tauern region

    NASA Astrophysics Data System (ADS)

    Binder, Daniel; Hartmeyer, Ingo; Keuschnig, Markus; Mertl, Stefan; Lenhardt, Wolfgang

    2016-04-01

    SeisRockHT focuses on open hardware and free software applied for scientific long-term monitoring strategies in harsh environments. In detail, SeisRockHT aims at the establishment of two seismic networks to quantitatively observe seismicity and rockfall events at high alpine north faces. Due to the rare character of rockfall events, a continuous and long-term observation strategy is targeted. The long-term perspective is assured through the project partner of the Austrian seismic service who will include SeisRockHT networks when the project is completed. Two study sites were selected for monitoring: the Kitzsteinhorn and the Hohe Sonnblick exhibiting two different scales of monitoring networks. The smaller scaled Kitzsteinhorn investigation site is closely related to bedrock permafrost processes, whereas the larger-scaled Sonnblick investigation site aims a classic alpine north face. SeisRockHT will develop a suite of optimum methods for characterization, detection and localization of the seismic events recorded at the two sites. Beside analysis of discrete seismic events, ambient seismic noise analysis promises a closer insight into rockfall precursory seismic characteristics.Based on the high quality complementary data delivered by already established long-term monitoring projects at the two sites, potential rockfall triggers will be suggested.

  17. Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks.

    PubMed

    Yang, Yaowen; Annamdas, Venu Gopal Madhav; Wang, Chao; Zhou, Yingxin

    2008-01-21

    Reliable structural health monitoring (SHM) including nondestructiveevaluation (NDE) is essential for safe operation of infrastructure systems. Effectivemonitoring of the rock components of civil infrastructures such as tunnels and cavernsremains challenging. The feasibility of employing smart optical fibre sensor (OFS) andpiezoelectric impedance sensor made up of lead zirconate titanate (PZT) forcomprehensive health monitoring of rocks, covering load history monitoring/retrieval aswell as damage assessment is presented in this paper. The rock specimens are subjected tocyclic loading and their conditions are continuously monitored using OFS and PZTsensors. OFS based multiplexed fibre Bragg grating (FBG) sensors are surface bonded onthe rock specimens. Their strain sensing performance is compared with the conventionalelectric strain gauges (ESGs). In addition, PZT patches are also bonded on the specimensto study the damage pattern during different loading cycles. Unlike the FBGs or ESGs,PZT patches are used as bi-functional sensors and actuators, enabling them to be efficientdetectors of incipient damages using the principle of electromechanical impedance. Theexperimental study demonstrated superior performance of these smart FBG and PZTimpedance sensors. This work is expected to be useful for SHM based NDE application ofrock structures such as caverns and tunnels.

  18. The RHYTMME system: an operational real-time warning and mapping system for flash floods, debris flows, landslide and rock falls in Southeastern France.

    NASA Astrophysics Data System (ADS)

    Fouchier, Catherine; Mériaux, Patrice; Atger, Frédéric; Ecrepont, Stéphane; Liébault, Frédéric; Bertrand, Mélanie; Bel, Coraline; Batista, Dominique; Azemard, Pierre; Saint-Martin, Clotilde; Javelle, Pierre

    2016-04-01

    Almost all municipalities of Southeastern France are concerned by natural hazards triggered by heavy rainfalls such as floods, debris flows, landslides and rock falls. Although some tools exist to forecast and monitor heavy rains and floods in France, their spatial resolution sometimes does not meet the needs of local risk managers who have to monitor events at a small spatial scale. In order to improve the risk management in the mountainous and Mediterranean areas of Southeastern France, Irstea and Météo-France have led the RHYTMME project. The goal of this project is to improve the ability to forecast and localize high-risk rainfall-induced hazards in the Provence-Alpes-Côte d'Azur administrative area. This goal is currently under achievement thanks to the implementation of a real-time warning and mapping system for rainfall induced natural hazards, fed by radar data and whose outputs are made available via the Internet to operators in charge of risk management (local and regional authorities, emergency and rescue services, road and rail networks managers, ...). This system provides maps which display in real-time: - the radar estimations of rainfall for different rain durations and at the spatial resolution of 1 km² (Westrelin et al., 2013), - the estimation of the scarcity of these rainfall estimations, also at the spatial resolution of 1 km², thanks to a comparison with threshold values provided by a regionalized stochastic hourly point rainfall generator (Arnaud et al., 2007), - an anticipation of the rivers discharges, computed at the outlet of 1700 watersheds of Southeastern France thanks to the AIGA warning system which combines a rainfall runoff model and an estimation of the scarcity of the discharges thanks to a comparison with threshold values (Javelle et al., 2014). Maps of susceptibility to debris flow, landslide and rock falls can also be displayed in the RHYTMME warning system along with the real time maps of rainfall hazard (Batista, 2013a

  19. Compressed air energy storage monitoring to support refrigerated mined rock cavern technology.

    SciTech Connect

    Lee, Moo Yul; Bauer, Stephen J.

    2004-06-01

    This document is the final report for the Compressed Air Energy Storage Monitoring to Support Refrigerated-Mined Rock Cavern Technology (CAES Monitoring to Support RMRCT) (DE-FC26-01NT40868) project to have been conducted by CAES Development Co., along with Sandia National Laboratories. This document provides a final report covering tasks 1.0 and subtasks 2.1, 2.2, and 2.5 of task 2.0 of the Statement of Project Objectives and constitutes the final project deliverable. The proposed work was to have provided physical measurements and analyses of large-scale rock mass response to pressure cycling. The goal was to develop proof-of-concept data for a previously developed and DOE sponsored technology (RMRCT or Refrigerated-Mined Rock Cavern Technology). In the RMRCT concept, a room and pillar mine developed in rock serves as a pressure vessel. That vessel will need to contain pressure of about 1370 psi (and cycle down to 300 psi). The measurements gathered in this study would have provided a means to determine directly rock mass response during cyclic loading on the same scale, under similar pressure conditions. The CAES project has been delayed due to national economic unrest in the energy sector.

  20. Corrosion monitoring of rock bolt by using a low coherent fiber-optic interferometry

    NASA Astrophysics Data System (ADS)

    Wei, Heming; Zhao, Xuefeng; Li, Dongsheng; Zhang, Pinglei; Sun, Changsen

    2015-04-01

    Corrosion of rock bolts is a major cause for deterioration of the anchor-reinforced concrete slopes structures. In order to evaluate this corrosion-based deterioration in an early stage, a nondestructive technique was required. However, until now, there are no commercialized solutions that are straightforwardly available. Here, a low-coherent fiber-optic sensing technique was developed. This method can carry out the monitoring of the corrosion-caused expansion at the accuracy of sub-microstrains by circled the sensing optical fiber in two ways. One was wound the fiber on the surface of steel rock bolt directly, and thereby generated a nonuniformity in the interface of cement with rock bolt. The other was circled the fiber on a cement mortar cushion without destroying the interface any way. The sensing fiber was configured as one arm of the fiber-optic Michelson interferometer. The acceleration corrosion experiments demonstrated that a uniform interface between cement and rock bolt determined the progress of corrosion development. An early stage evaluation of the corrosion development in rock bolts was monitored.

  1. Stress-Induced Fracturing of Reservoir Rocks: Acoustic Monitoring and μCT Image Analysis

    NASA Astrophysics Data System (ADS)

    Pradhan, Srutarshi; Stroisz, Anna M.; Fjær, Erling; Stenebråten, Jørn F.; Lund, Hans K.; Sønstebø, Eyvind F.

    2015-11-01

    Stress-induced fracturing in reservoir rocks is an important issue for the petroleum industry. While productivity can be enhanced by a controlled fracturing operation, it can trigger borehole instability problems by reactivating existing fractures/faults in a reservoir. However, safe fracturing can improve the quality of operations during CO2 storage, geothermal installation and gas production at and from the reservoir rocks. Therefore, understanding the fracturing behavior of different types of reservoir rocks is a basic need for planning field operations toward these activities. In our study, stress-induced fracturing of rock samples has been monitored by acoustic emission (AE) and post-experiment computer tomography (CT) scans. We have used hollow cylinder cores of sandstones and chalks, which are representatives of reservoir rocks. The fracture-triggering stress has been measured for different rocks and compared with theoretical estimates. The population of AE events shows the location of main fracture arms which is in a good agreement with post-test CT image analysis, and the fracture patterns inside the samples are visualized through 3D image reconstructions. The amplitudes and energies of acoustic events clearly indicate initiation and propagation of the main fractures. Time evolution of the radial strain measured in the fracturing tests will later be compared to model predictions of fracture size.

  2. IDENTIFYING ROOF FALL PREDICTORS USING FUZZY CLASSIFICATION

    SciTech Connect

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-22

    Microseismic monitoring involves placing geophones on the rock surfaces of a mine to record seismic activity. Classification of microseismic mine data can be used to predict seismic events in a mine to mitigate mining hazards, such as roof falls, where properly bolting and bracing the roof is often an insufficient method of preventing weak roofs from destabilizing. In this study, six months of recorded acoustic waveforms from microseismic monitoring in a Pennsylvania limestone mine were analyzed using classification techniques to predict roof falls. Fuzzy classification using features selected for computational ease was applied on the mine data. Both large roof fall events could be predicted using a Roof Fall Index (RFI) metric calculated from the results of the fuzzy classification. RFI was successfully used to resolve the two significant roof fall events and predicted both events by at least 15 hours before visual signs of the roof falls were evident.

  3. Monitoring rock freezing and thawing by novel geoelectrical and acoustic techniques

    NASA Astrophysics Data System (ADS)

    Murton, Julian B.; Kuras, Oliver; Krautblatter, Michael; Cane, Tim; Tschofen, Dominique; Uhlemann, Sebastian; Schober, Sandra; Watson, Phil

    2016-12-01

    Automated monitoring of freeze-thaw cycles and fracture propagation in mountain rockwalls is needed to provide early warning about rockfall hazards. Conventional geoelectrical methods such as electrical resistivity tomography (ERT) are limited by large and variable ohmic contact resistances, requiring galvanic coupling with metal electrodes inserted into holes drilled into rock, and which can be loosened by rock weathering. We report a novel experimental methodology that combined capacitive resistivity imaging (CRI), ERT, and microseismic event recording to monitor freeze-thaw of six blocks of hard and soft limestones under conditions simulating an active layer above permafrost and seasonally frozen rock in a nonpermafrost environment. Our results demonstrate that the CRI method is highly sensitive to freeze-thaw processes; it yields property information equivalent to that obtained with conventional ERT and offers a viable route for nongalvanic long-term geoelectrical monitoring, extending the benefits of the methodology to soft/hard rock environments. Contact impedances achieved with CRI are less affected by seasonal temperature changes, the aggregate state of the pore water (liquid or frozen), and the presence of low-porosity rock with high matrix resistivities than those achieved with ERT. Microseismic monitoring has the advantage over acoustic emissions that events were recorded in relevant field distances of meters to decameters from cracking events. For the first time we recorded about 1000 microcracking events and clustered them in four groups according to frequency and waveform. Compared to previous studies, mainly on ice-cracking in glaciers, the groups are attributed to single- or multiple-stage cracking events such as crack coalescence.

  4. A posture recognition based fall detection system for monitoring an elderly person in a smart home environment.

    PubMed

    Yu, Miao; Rhuma, Adel; Naqvi, Syed Mohsen; Wang, Liang; Chambers, Jonathon

    2012-11-01

    We propose a novel computer vision based fall detection system for monitoring an elderly person in a home care application. Background subtraction is applied to extract the foreground human body and the result is improved by using certain post-processing. Information from ellipse fitting and a projection histogram along the axes of the ellipse are used as the features for distinguishing different postures of the human. These features are then fed into a directed acyclic graph support vector machine (DAGSVM) for posture classification, the result of which is then combined with derived floor information to detect a fall. From a dataset of 15 people, we show that our fall detection system can achieve a high fall detection rate (97.08%) and a very low false detection rate (0.8%) in a simulated home environment.

  5. Using haplotypes to monitor the migration of fall armyworm (Lepidoptera: Noctuidae) corn-strain populations from Texas and Florida.

    PubMed

    Nagoshi, Rodney N; Meagher, Robert L; Flanders, Kathy; Gore, Jeffrey; Jackson, Ryan; Lopez, Juan; Armstrong, John S; Buntin, G David; Sansone, Chris; Leonard, B Rogers

    2008-06-01

    Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), infestations in most of North America north of Mexico arise from annual migrations of populations that overwinter in southern Texas and Florida. A comparison of the cytochrome oxidase I haplotype profiles within the fall armyworm corn-strain, the subgroup that preferentially infests corn (Zea mays L.) and sorghum (Sorghum vulgare Pers.), identified significant differences in the proportions of certain haplotypes between the Texas and Florida populations. These proportional differences were preserved as the populations migrated, providing a molecular metric by which the source of a migrant population could be identified. The migratory pattern derived from this method for several southeastern states was shown to be consistent with predictions based on analysis of historical agricultural and fall armyworm infestation data. These results demonstrate the utility of haplotype proportions to monitor fall armyworm migration, and they also introduce a potential method to predict the severity of cotton crop infestations in the short term.

  6. Evaluation of Feature Extraction and Recognition for Activity Monitoring and Fall Detection Based on Wearable sEMG Sensors.

    PubMed

    Xi, Xugang; Tang, Minyan; Miran, Seyed M; Luo, Zhizeng

    2017-05-27

    As an essential subfield of context awareness, activity awareness, especially daily activity monitoring and fall detection, plays a significant role for elderly or frail people who need assistance in their daily activities. This study investigates the feature extraction and pattern recognition of surface electromyography (sEMG), with the purpose of determining the best features and classifiers of sEMG for daily living activities monitoring and fall detection. This is done by a serial of experiments. In the experiments, four channels of sEMG signal from wireless, wearable sensors located on lower limbs are recorded from three subjects while they perform seven activities of daily living (ADL). A simulated trip fall scenario is also considered with a custom-made device attached to the ankle. With this experimental setting, 15 feature extraction methods of sEMG, including time, frequency, time/frequency domain and entropy, are analyzed based on class separability and calculation complexity, and five classification methods, each with 15 features, are estimated with respect to the accuracy rate of recognition and calculation complexity for activity monitoring and fall detection. It is shown that a high accuracy rate of recognition and a minimal calculation time for daily activity monitoring and fall detection can be achieved in the current experimental setting. Specifically, the Wilson Amplitude (WAMP) feature performs the best, and the classifier Gaussian Kernel Support Vector Machine (GK-SVM) with Permutation Entropy (PE) or WAMP results in the highest accuracy for activity monitoring with recognition rates of 97.35% and 96.43%. For fall detection, the classifier Fuzzy Min-Max Neural Network (FMMNN) has the best sensitivity and specificity at the cost of the longest calculation time, while the classifier Gaussian Kernel Fisher Linear Discriminant Analysis (GK-FDA) with the feature WAMP guarantees a high sensitivity (98.70%) and specificity (98.59%) with a short

  7. Long-term monitoring of rock mass properties in the underground excavation

    NASA Astrophysics Data System (ADS)

    Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav

    2015-04-01

    It is generally agreed today that hazardous waste should be placed in repositories hundreds of meters below the Earth's surface. In our research we deal with the long-term monitoring of the underground excavation by seismic and electrical resistivity measurements. Permanent measuring system was developed and installed at the Bedřichov gallery test site (northern Bohemia). The gallery was excavated using TBM (Tunnel Boring Machine) in granitic rocks. Realized repeated measurements include ultrasonic time of flight measurement and electrical resistivity tomography (ERT). The seismic measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The main emphasis is devoted to P-waves; however, recording of full waveform enables analyzing of S- waves and other types of waves as well. The comparison of repeated measurements is used for an assessment of changes in seismic velocities with very high-accuracy. The repetition rate of measurements can be selected from seconds; however such fast changes in the rock mass are unexpected. The ERT measurement is performed on the same rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. The conductivity of undisturbed granitic rocks is extremely low. Therefore the observed local increase of conductivity can be associated with joints and fractures saturated with water, resulting in their ionic conductivity. Repeated ERT measurement can reveal some changes in the rock mass. Due to time requirements of ERT measurement the repetition rate can be about three hours. The data collected by measuring system is transferred by means of computer network and can be accessed via internet. This contribution deals with preliminary results gained so far during the testing of developed monitoring system. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA

  8. Monitoring borehole flow dynamics using heated fiber optic DTS in a fractured rock aquifer

    NASA Astrophysics Data System (ADS)

    Coleman, Thomas; Chalari, Athena; Parker, Beth; Munn, Jonathan; Mondanos, Michael

    2014-05-01

    Temperature profiles in fractured rock have long been used to identify and characterize flow in the rock formation or in the borehole. Fiber optic distributed temperature sensing (DTS) is a tool that allows for continuous borehole temperature profiling in space and time. Recent technology advancements in the spatial, temperature, and temporal resolutions of DTS systems now allow temperature profiling methods to offer improved insight into fractured rock hydrogeologic processes. An innovation in shallow borehole temperature logging utilizes high resolution DTS temperature profiling in sealed and heated boreholes to identify fractures with natural gradient groundwater flow by creating a thermal disequilibrium and monitoring the temperature response. This technique can also be applied to open well conditions to monitor borehole flow distributions caused by hydraulic perturbations such as pumping or injection. A field trial was conducted in Guelph, Ontario, Canada to determine the capabilities of heated DTS for flow monitoring in both open and sealed wells. Intelligent distributed acoustic sensing (iDAS) measurements for vertical seismic profiling were carried out simultaneously with the DTS measurements to assist with characterization of the fractured aquifer system. DTS heat pulse tests were conducted in a single well under sealed conditions for natural gradient flow measurements and open conditions to monitor flow distributions during injection and pumping. The results of these tests indicate that borehole flow distributions can be monitored using DTS and that active heating allows for further information about the hydrogeologic system to be determined than from the passive measurements alone. Depth-continuous transmissivity data from the borehole correlate well with the DTS testing results. DTS based flow monitoring systems may be useful for monitoring transient production and injection processes for a variety of applications including groundwater remediation

  9. Subsurface hydrological information in rock-slide phenomena from groundwater spring monitoring.

    NASA Astrophysics Data System (ADS)

    Rochetti, Francesco; Corsini, Alessandro; Deiana, Manuela; Loche, Roberto; Mulas, Marco; Russo, Michele

    2016-04-01

    Frequently rock-slide phenomena are characterized by rough topography and high declivity of the slope. Due to these characteristics, the drilling of boreholes is not so common and in some circumstance expensive. Consequently, the exact information about depth of the sliding surface and about groundwater processes, groundwater levels or pore water pressure distribution are missing. Alternately, some information about the groundwater can be obtained from the physical-chemical monitoring of springs. The research highlights preliminary results, about the groundwater processes, obtained from the continuous flow-rate monitoring of a spring located in the active Piagneto rock-slide (northern Apennine). The spring has been monitored from Sept-2014 until Oct-2015 using a piezometer transducer (sampling frequency 1 h) and a triangular weir. The landslide was monitored in continuous since the 2009 using an automatic total station and some reflectors. The monitoring of the rock-slide displacements showed creep phenomena in the summer and acceleration phases from autumn to late spring, during periods characterized by high rainfall intensity; rainfall with intensity higher than 10 mm/d and duration less than 15 days can produce the acceleration of the sliding mass. Before 2014 any information about groundwater was collected. The successively spring monitoring shows the follow results: the spring flow rate is strongly variable in the time; only some rainfall events, with particular intensity and duration (generally total amount higher than 100 mm), are responsible of strong changes in the flow rate, and the flow rate starts to increase only after some hours; the snow melting events, also when there is a fast reduction of the snow thickness, don't produce high variation in the flow rate discharge; there is a strong correlation between the flow rate peaks and the rock-slide acceleration; an infiltration coefficient higher than 70% is estimated through the comparison between the

  10. Monitoring rock glacier dynamics and ground temperatures in the semiarid Andes (Chile, 30°S)

    NASA Astrophysics Data System (ADS)

    Brenning, Alexander; Azócar, Guillermo F.; Bodin, Xavier

    2013-04-01

    Rock glaciers and mountain permafrost are widespread in the high semiarid Andes of Chile, where they concentrate greater amounts of ice than glaciers. Rock glaciers are of particular interest because in some cases the permafrost they contain might be in a degrading in response to climatic warming. This could result in increased dynamics and even to destabilization, which has been observed on some rock glaciers in the studied area. Displacement rates and active-layer temperatures of two rock glaciers as well as ground surface temperatures of the periglacial environment in the upper Elqui valley have been monitored since summer 2009/10 with funding from the Chilean Dirección General de Aguas. Differential GPS measurements of 115 points on the surface of two rock glaciers since April 2010 showed horizontal displacements of up to 1.3 m/a on the Llano de las Liebres rock glacier and up to 1.2 m/a on the Tapado rock glacier. General velocity patterns are consistent with the morphological evidence of activity (e.g., front slopes, looseness of debris) and for the Tapado complex, a clearly distinct activity from the debris-covered glacier was observed. Temperature measurements in four boreholes indicate active-layer depths of about 2.5 m at the highest locations on the Tapado rock glacier (~4400 m a.s.l.) and about 8 m near the front of the Llano rock glacier (3786 m a.s.l.). Spatial patterns of mean ground surface temperature (MGST) were analyzed with regards to influences of elevation, potential incoming solar radiation, location on ice-debris landforms (rock and debris-covered glaciers), and snow cover duration using linear mixed-effects models. While accounting for the other variables, sites with long-lasting snow patches had ~0.4°C lower MGST, and ice-debris landforms had ~0.4-0.6°C lower MGST than general debris surfaces, highlighting important local modifications to the general topographic variation of ground thermal conditions.

  11. Towards improved electrical imaging and monitoring of groundwater in fractured rock aquifers (Invited)

    NASA Astrophysics Data System (ADS)

    Robinson, J.; Slater, L. D.; Johnson, T.

    2013-12-01

    There is an increasing need to characterize fractured rock aquifers and to monitor the movement of fluids in these systems. Fractured rock aquifers are increasingly exploited for water resources, and are subject to contamination from industrial activities at the Earth's surface. Geophysical imaging technologies are increasingly applied in an effort to overcome the limitations of sparsely located direct observations of subsurface properties. However, the application of geophysical technologies to fractured rock systems presents challenges as appropriate regularization model constraints for complex, heterogeneous systems are hard to define without additional subsurface information. Cross-borehole electrical resistivity tomography (ERT) is a candidate hydrogeophysical technology for remotely imaging fractured rock, as the interconnected fracture networks will serve as the primary pathways for both fluid and electrical current flow. However, three major challenges have hindered the application of ERT in fractured rock systems: [1] the heterogeneous electrical conductivity structure associated with electrically conductive fractures in a resistive matrix requires a full 3D inversion at high spatial resolution; [2] boreholes drilled in fractured rock aquifers represent highly conductive features that must be accurately modeled in the numerical forward and inverse modeling through supporting field data; [3] appropriate regularization constraints required to represent fractures are difficult to define in the inverse modeling given the limited ground truth information typically available. We describe strategies to improve the characterization and monitoring of discrete fracture networks from ERT surveys. We first consider synthetic scenarios based on the geology of a fractured mudstone aquifer that has been extensively contaminated by chlorinated solvents. We then revisit an early case study where a 3D ERT dataset was used to image a bedding plane system and supporting

  12. Strategies for rock slope failure early warning using acoustic emission monitoring

    NASA Astrophysics Data System (ADS)

    Codeglia, D.; Dixon, N.; Fowmes, G. J.; Marcato, G.

    2015-09-01

    Research over the last two decades has led to development of a system for soil slopes monitoring based on the concept of measuring Acoustic Emission (AE). A feature of the system is the use of waveguides installed within unstable soil slopes. It has been demonstrated that the AE measured through this technique are proportional to soil displacement rate. Attention has now been focused on the prospect of using the system within rock materials. The different nature of the slope material to be monitored and its setting means that different acoustic trends are measured, and development of new approaches for their interpretation are required. A total of six sensors have been installed in two pilot sites, firstly in Italy, for monitoring of a stratified limestone slope which can threaten a nationally important road, and secondly in Austria, for monitoring of a conglomerate slope that can endanger a section of the local railway. In this paper an outline of the two trial sites is given and AE data collected are compared with other physical measurements (i.e. rainfall and temperature) and traditional geotechnical instrumentation, to give an overview of recurring AE trends. These include clear AE signatures generated by stress changes linked to increased ground water levels and high energy events generated by freeze-thaw of the rock mass.

  13. Integrating GIS-based geologic mapping, LiDAR-based lineament analysis and site specific rock slope data to delineate a zone of existing and potential rock slope instability located along the grandfather mountain window-Linville Falls shear zone contact, Southern Appalachian Mountains, Watauga County, North Carolina

    USGS Publications Warehouse

    Gillon, K.A.; Wooten, R.M.; Latham, R.L.; Witt, A.W.; Douglas, T.J.; Bauer, J.B.; Fuemmeler, S.J.

    2009-01-01

    Landslide hazard maps of Watauga County identify >2200 landslides, model debris flow susceptibility, and evaluate a 14km x 0.5km zone of existing and potential rock slope instability (ZEPRSI) near the Town of Boone. The ZEPRSI encompasses west-northwest trending (WNWT) topographic ridges where 14 active/past-active rock/weathered rock slides occur mainly in rocks of the Grandfather Mountain Window (GMW). The north side of this ridgeline is the GMW / Linville Falls Fault (LFF) contact. Sheared rocks of the Linville Falls Shear Zone (LFSZ) occur along the ridge and locally in the valley north of the contact. The valley is underlain principally by layered granitic gneiss comprising the Linville Falls/Beech Mountain/Stone Mountain Thrust Sheet. The integration of ArcGIS??? - format digital geologic and lineament mapping on a 6m LiDAR (Light Detecting and Ranging) digital elevation model (DEM) base, and kinematic analyses of site specific rock slope data (e.g., presence and degree of ductile and brittle deformation fabrics, rock type, rock weathering state) indicate: WNWT lineaments are expressions of a regionally extensive zone of fractures and faults; and ZEPRSI rock slope failures concentrate along excavated, north-facing LFF/LFSZ slopes where brittle fabrics overprint older metamorphic foliations, and other fractures create side and back release surfaces. Copyright 2009 ARMA, American Rock Mechanics Association.

  14. Cloud-Based Smart Health Monitoring System for Automatic Cardiovascular and Fall Risk Assessment in Hypertensive Patients.

    PubMed

    Melillo, P; Orrico, A; Scala, P; Crispino, F; Pecchia, L

    2015-10-01

    The aim of this paper is to describe the design and the preliminary validation of a platform developed to collect and automatically analyze biomedical signals for risk assessment of vascular events and falls in hypertensive patients. This m-health platform, based on cloud computing, was designed to be flexible, extensible, and transparent, and to provide proactive remote monitoring via data-mining functionalities. A retrospective study was conducted to train and test the platform. The developed system was able to predict a future vascular event within the next 12 months with an accuracy rate of 84 % and to identify fallers with an accuracy rate of 72 %. In an ongoing prospective trial, almost all the recruited patients accepted favorably the system with a limited rate of inadherences causing data losses (<20 %). The developed platform supported clinical decision by processing tele-monitored data and providing quick and accurate risk assessment of vascular events and falls.

  15. An overview of geophysical technologies appropriate for characterization and monitoring at fractured-rock sites.

    PubMed

    Day-Lewis, Frederick D; Slater, Lee D; Robinson, Judy; Johnson, Carole D; Terry, Neil; Werkema, Dale

    2017-04-20

    Geophysical methods are used increasingly for characterization and monitoring at remediation sites in fractured-rock aquifers. The complex heterogeneity of fractured rock poses enormous challenges to groundwater remediation professionals, and new methods are needed to cost-effectively infer fracture and fracture-zone locations, orientations and properties, and to develop conceptual site models for flow and transport. Despite the potential of geophysical methods to "see" between boreholes, two issues have impeded the adoption of geophysical methods by remediation professionals. First, geophysical results are commonly only indirectly related to the properties of interest (e.g., permeability) to remediation professionals, and qualitative or quantitative interpretation is required to convert geophysical results to hydrogeologic information. Additional demonstration/evaluation projects are needed in the site remediation literature to fully transfer geophysical methods from research to practice. Second, geophysical methods are commonly viewed as inherently risky by remediation professionals. Although it is widely understood that a given method may or may not work at a particular site, the reasons are not always clear to end users of geophysical products. Synthetic modeling tools are used in research to assess the potential of a particular method to successfully image a target, but these tools are not widely used in industry. Here, we seek to advance the application of geophysical methods to solve problems facing remediation professionals with respect to fractured-rock aquifers. To this end, we (1) provide an overview of geophysical methods applied to characterization and monitoring of fractured-rock aquifers; (2) review case studies showcasing different geophysical methods; and (3) discuss best practices for method selection and rejection based on synthetic modeling and decision support tools. Published by Elsevier Ltd.

  16. Aquifers survey in the context of source rocks exploitation: from baseline acquisition to long term monitoring

    NASA Astrophysics Data System (ADS)

    Garcia, Bruno; Rouchon, Virgile; Deflandre, Jean-Pierre

    2017-04-01

    Producing hydrocarbons from source rocks (like shales: a mix of clays, silts, carbonate and sandstone minerals containing matured organic matter, i.e. kerogen oil and gas, but also non-hydrocarbon various species of chemical elements including sometimes radioactive elements) requires to create permeability within the rock matrix by at least hydraulically fracturing the source rock. It corresponds to the production of hydrocarbon fuels that have not been naturally expelled from the pressurized matured source rock and that remain trapped in the porosity or/and kerogen porosity of the impermeable matrix. Azimuth and extent of developed fractures can be respectively determined and mapped by monitoring the associated induced microseismicity. This allows to have an idea of where and how far injected fluids penetrated the rock formation. In a geological context, aquifers are always present in the vicinity -or on fluid migration paths- of such shale formations: deep aquifers (near the shale formation) up to sub-surface and potable (surface) aquifers. Our purpose will be to track any unsuitable invasion or migration of chemicals specifies coming from matured shales of production fluids including both drilling and fracturing ones into aquifers. Our objective is to early detect and alarm of any anomaly to avoid any important environmental issue. The approach consists in deploying a specific sampling tool within a well to recover formation fluids and to run a panoply of appropriate laboratory tests to state on fluid characteristics. Of course for deep aquifers, such a characterization process may consider aquifer properties prior producing shale oil and gas, as they may contain naturally some chemical species present in the source rocks. One can also consider that a baseline acquisition could be justified in case of possible previous invasion of non-natural fluids in the formation under survey (due to any anthropogenic action at surface or in the underground). The paper aims

  17. Active Seismic Monitoring of Crack Initiation, Propagation, and Coalescence in Rock

    NASA Astrophysics Data System (ADS)

    Modiriasari, Anahita; Bobet, Antonio; Pyrak-Nolte, Laura J.

    2017-09-01

    Active seismic monitoring was used to detect and characterize crack initiation, crack propagation and crack coalescence in pre-cracked rock specimens. Uniaxial compression tests were conducted on Indiana limestone specimens with two parallel pre-existing cracks. During the experiments, the mechanically induced cracks around the flaw tips were monitored by measuring surface displacements using digital image correlation (DIC). Transmitted and reflected compressional and shear waves through the specimens were also recorded during the loading to detect any damage or cracking phenomena. The amplitude of transmitted compressional and shear waves decreased with uniaxial compression. However, the rate of decrease of the amplitude of the transmitted waves intensified well before the initiation of tensile cracks. In addition, a distinct minimum in the amplitude of transmitted waves occurred close to coalescence. The normalized amplitude of waves reflecting from the new cracks increased before new tensile and shear cracks initiated around the flaw tips. In addition, the location of new cracks could be identified using the traveling time of the reflected waves. The experimental results indicate that changes in normalized amplitude of transmitted and reflected signals associated with crack initiation and crack coalescence were detected much earlier than with DIC, at a load of about 80-90% of the load at which the cracks appeared on the surface. The tests show conclusively that active wave monitoring is an effective tool to detect damage and new cracks in rock, as well as to estimate the location of the new cracks.

  18. Concept of Complex Environmental Monitoring Network - Vardzia Rock Cut City Case Study

    NASA Astrophysics Data System (ADS)

    Elashvili, Mikheil; Vacheishvili, Nikoloz; Margottini, Claudio; Basilaia, Giorgi; Chkhaidze, Davit; Kvavadze, Davit; Spizzichino, Daniele; Boscagli, Franceso; Kirkitadze, Giorgi; Adikashvili, Luka; Navrozashvili, Levan

    2016-04-01

    Vardzia represents an unique cultural heritage monument - rock cut city, which unites architectural monument and Natural-Geological complex. Such monuments are particularly vulnerable and their restoration and conservation requires complex approach. It is curved in various layers of volcanic tuffs and covers several hectares of area, with chronologically different segments of construction. This monument, as many similar monuments worldwide, is subjected to slow but permanent process of destruction, expressed in following factors: surface weathering of rock, active tectonics (aseismic displacement along the active faults and earthquakes), interaction between lithologically different rock layers, existence of major cracks and associated complex block structure, surface rainwater runoff and infiltrated ground water, temperature variations, etc. During its lifetime, Vardzia was heavily damaged by Historical Earthquake of 1283 and only partly restored afterwards. The technological progress together with the increased knowledge about ongoing environmental processes, established the common understanding that the complex monitoring of the environment represents the essential component for resolving such a principal issues, as: Proper management and prevention of natural disasters; Modeling of environmental processes, their short and long term prognosis; Monitoring of macro and micro climate; Safe functioning and preservation of important constructions. Research Center of Cultural Heritage and Environment of Ilia State University in cooperation with Experts from ISPRA, with the funding from the State agency of Cultural Heritage, has developed a concept of Vardzia complex monitoring network. Concept of the network includes: monitoring local meteorological conditions (meteorological station), monitoring microclimate in caves (temperature and humidity in the air and rock), monitoring microtremors and ambient seismic noise in Vardzia (local strong motion network), monitoring

  19. The PARAChute Project: Remote Monitoring of Posture and Gait for Fall Prevention

    NASA Astrophysics Data System (ADS)

    Hewson, David J.; Duchêne, Jacques; Charpillet, François; Saboune, Jamal; Michel-Pellegrino, Valérie; Amoud, Hassan; Doussot, Michel; Paysant, Jean; Boyer, Anne; Hogrel, Jean-Yves

    2007-12-01

    Falls in the elderly are a major public health problem due to both their frequency and their medical and social consequences. In France alone, more than two million people aged over 65 years old fall each year, leading to more than 9 000 deaths, in particular in those over 75 years old (more than 8 000 deaths). This paper describes the PARAChute project, which aims to develop a methodology that will enable the detection of an increased risk of falling in community-dwelling elderly. The methods used for a remote noninvasive assessment for static and dynamic balance assessments and gait analysis are described. The final result of the project has been the development of an algorithm for movement detection during gait and a balance signature extracted from a force plate. A multicentre longitudinal evaluation of balance has commenced in order to validate the methodologies and technologies developed in the project.

  20. Exploring the feasibility and acceptability of sensor monitoring of gait and falls in the homes of persons with multiple sclerosis.

    PubMed

    Newland, Pamela; Wagner, Joanne M; Salter, Amber; Thomas, Florian P; Skubic, Marjorie; Rantz, Marilyn

    2016-09-01

    Gait parameters variability and falls are problems for persons with MS and have not been adequately captured in the home. Our goal was to explore the feasibility and acceptability of monitoring of gait and falls in the homes of persons with MS over a period of 30 days. To test the feasibility of measuring gait and falls for 30days in the home of persons with MS, spatiotemporal gait parameters stride length, stride time, and gait speed were compared. A 3D infrared depth imaging system has been developed to objectively measure gait and falls in the home environment. Participants also completed a 16-foot GaitRite electronic pathway walk to validate spatiotemporal parameters of gait (gait speed (cm/s), stride length (cm), and gait cycle time(s)) during the timed 25 foot walking test (T25FWT). We also documented barriers to feasibility of installing the in-home sensors for these participants. The results of the study suggest that the Kinect sensor may be used as an alternative device to measure gait for persons with MS, depending on the desired accuracy level. Ultimately, using in-home sensors to analyze gait parameters in real time is feasible and could lead to better analysis of gait in persons with MS.

  1. Acid-rain related reconnaissance of water, rock, soil, and sediment chemistry in the Adirondacks during Fall, 1981

    SciTech Connect

    Not Available

    1981-01-01

    This study suggests strongly that inorganic chemical processes, with sulfate and nitrate input from atmospheric deposition and the absence of buffering from carbonate rock, cannot simply account for either the pH or the aluminum concentrations observed in Adirondack surface waters. Instead, organic acids originating from water flow through organic soil layers and wetlands are indicated as possible causes of increased acidity and aluminum concentrations. There are also indications that sulfides in bedrock and the sulfur utilized by vegetation may be important surface-water sulfate sources. Further, in part of the Adirondacks, weathering of calcium-containing non-carbonate aluminosilicate bedrock apparently keeps surface water from reaching ''critical'' acidity levels. Also, appreciable concentrations of heavy metals and persistent insecticides associated with the organic material in some soils and sediments. If mobilized into the food chain, these materials could be causing adverse ecological effects usually attributed to acid precipitation. Recommendations are included for further studies. 13 figs., 29 tabs. (PSB)

  2. Report on the performance monitoring system for the interim waste containment at the Niagara Falls Storage Site, Lewiston, New York

    SciTech Connect

    Not Available

    1985-10-01

    The Niagara Falls Storage Site (NFSS) is an interim storage site for low-level radioactive waste, established by the US Department of Energy (DOE) at Lewiston, New York. The waste containment structure for encapsulating low-level radioactive waste at the NFSS has been designed to minimize infiltration of rainfall, prevent pollution of groundwater, preclude formation of leachate, and prevent radon emanation. Accurately determining the performance of the main engineered elements of the containment structure will be important in establishing confidence in the ability of the structure to retain the wastes. For this purpose, a waste containment performance monitoring system has been developed to verify that these elements are functioning as intended. The key objective of the performance monitoring system is the early detection of trends that could be indicative of weaknesses developing in the containment structure so that corrective action can be taken before the integrity of the structure is compromised. Consequently, subsurface as well as surface monitoring techniques will be used. After evaluating several types of subsurface instrumentation, it was determined that vibrating wire pressure transducers, in combination with surface monitoring techniques, would satisfactorily monitor the parameters of concern, such as water accumulation inside the containment facility, waste settlement, and shrinkage of the clay cover. Surface monitoring will consist of topographic surveys based on predetermined gridlines, walkover surveys, and aerial photography to detect vegetative stress or other changes not evident at ground level. This report details the objectives of the performance monitoring system, identifies the elements of the containment design whose performance will be monitored, describes the monitoring system recommended, and outlines the costs associated with the monitoring system. 5 refs., 4 figs., 3 tabs.

  3. Deformation Monitoring of Waste-Rock-Backfilled Mining Gob for Ground Control

    PubMed Central

    Zhao, Tongbin; Zhang, Yubao; Zhang, Zhenyu; Li, Zhanhai; Ma, Shuqi

    2017-01-01

    Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at −700 m depth in the Tangshan coal mine, Hebei Province, China. The designed deformation sensors, based on a resistance transducer mechanism, were placed vertically between the roof and floor. Stress sensors were installed above square steel plates that were anchored to the floor strata. Meanwhile, data cables were protected by steel tubes in case of damage. The developed system continually harvested field data for three months. The results show that industrial Ethernet technology can be reliably used for long-term data transmission in complicated underground mining conditions. The monitoring reveals that the roof subsidence of the backfilled gob area can be categorized into four phases. The bearing load of the backfill developed gradually and simultaneously with the deformation of the roof strata, and started to be almost invariable when the mining face passed 97 m. PMID:28475168

  4. Deformation Monitoring of Waste-Rock-Backfilled Mining Gob for Ground Control.

    PubMed

    Zhao, Tongbin; Zhang, Yubao; Zhang, Zhenyu; Li, Zhanhai; Ma, Shuqi

    2017-05-05

    Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at -700 m depth in the Tangshan coal mine, Hebei Province, China. The designed deformation sensors, based on a resistance transducer mechanism, were placed vertically between the roof and floor. Stress sensors were installed above square steel plates that were anchored to the floor strata. Meanwhile, data cables were protected by steel tubes in case of damage. The developed system continually harvested field data for three months. The results show that industrial Ethernet technology can be reliably used for long-term data transmission in complicated underground mining conditions. The monitoring reveals that the roof subsidence of the backfilled gob area can be categorized into four phases. The bearing load of the backfill developed gradually and simultaneously with the deformation of the roof strata, and started to be almost invariable when the mining face passed 97 m.

  5. Disentangling the health benefits of walking from increased exposure to falls in older people using remote gait monitoring and multi-dimensional analysis.

    PubMed

    Brodie, Matthew A; Okubo, Yoshiro; Annegarn, Janneke; Wieching, Rainer; Lord, Stephen R; Delbaere, Kim

    2017-01-01

    Falls and physical deconditioning are two major health problems for older people. Recent advances in remote physiological monitoring provide new opportunities to investigate why walking exercise, with its many health benefits, can both increase and decrease fall rates in older people. In this paper we combine remote wearable device monitoring of daily gait with non-linear multi-dimensional pattern recognition analysis; to disentangle the complex associations between walking, health and fall rates. One week of activities of daily living (ADL) were recorded with a wearable device in 96 independent living older people prior to completing 6 months of exergaming interventions. Using the wearable device data; the quantity, intensity, variability and distribution of daily walking patterns were assessed. At baseline, clinical assessments of health, falls, sensorimotor and physiological fall risks were completed. At 6 months, fall rates, sensorimotor and physiological fall risks were re-assessed. A non-linear multi-dimensional analysis was conducted to identify risk-groups according to their daily walking patterns. Four distinct risk-groups were identified: The Impaired (93% fallers), Restrained (8% fallers), Active (50% fallers) and Athletic (4% fallers). Walking was strongly associated with multiple health benefits and protective of falls for the top performing Athletic risk-group. However, in the middle of the spectrum, the Active risk-group, who were more active, younger and healthier were 6.25 times more likely to be fallers than their Restrained counterparts. Remote monitoring of daily walking patterns may provide a new way to distinguish Impaired people at risk of falling because of frailty from Active people at risk of falling from greater exposure to situations were falls could occur, but further validation is required. Wearable device risk-profiling could help in developing more personalised interventions for older people seeking the health benefits of walking

  6. Rock Slope Monitoring from 4D Time-Lapse Structure from Motion Analysis

    NASA Astrophysics Data System (ADS)

    Kromer, Ryan; Abellan, Antonio; Chyz, Alex; Hutchinson, Jean

    2017-04-01

    Structure from Motion (SfM) photogrammetry has become an important tool for studying earth surface processes because of its flexibility, ease of use, low cost and its capability of producing high quality 3-D surface models. A major benefit of SfM is that model accuracy is fit for purpose and surveys can be designed to meet a large range of spatial and temporal scales. In the Earth sciences, research in time-lapse SfM photogrammetry or videogrammetry is an area that is difficult to undertake due to complexities in acquiring, processing and managing large 4D datasets and represents an area with significant advancement potential (Eltner et al. 2016). In this study, we investigate the potential of 4D time-lapse SfM to monitor unstable rock slopes. We tested an array of statically mounted cameras collecting time-lapse photos of a limestone rock slope located along a highway in Canada. Our setup consisted of 8 DSLR cameras with 50 mm prime lenses spaced 2-3 m apart at a distance of 10 m from the slope. The portion of the rock slope monitored was 20 m wide and 6 m high. We collected data in four phases, each having 50 photographs taken simultaneously by each camera. The first phase of photographs was taken of the stable slope. In each successive phase, we gradually moved small, discrete blocks within the rock slope by 5-15 mm, simulating pre-failure deformation of rockfall. During the last phase we also removed discrete rock blocks, simulating rockfall. We used Agisoft Photoscan's 4D processing functionality and timeline tools to create 3D point clouds from the time-lapse photographs. These tools have the benefit of attaining better accuracy photo alignments as a greater number of photos are used. For change detection, we used the 4D filtering and calibration technique proposed by Kromer et al. (2015), which takes advantage of high degrees of spatial and temporal point redundancy to decrease measurement uncertainty. Preliminary results show that it is possible to attain

  7. Seismic monitoring of soft-rock landslides: New case study at Pechgraben mudslide - Upper Austria

    NASA Astrophysics Data System (ADS)

    Vouillamoz, Naomi; Santoyo, Juan Carlos; Ottowitz, David; Jochum, Birgit; Pfeiler, Stefan; Supper, Robert; Joswig, Manfred

    2016-04-01

    Creeping soft-rock landslides trigger various seismic signals which relate to key dynamics of the slope instability. A new seismic monitoring study is carried out at Pechgraben - Upper Austria, where a clay-shale rich mudslide was reactivated in summer 2013 after heavy rainfalls. The well geophysical instrumentation of the Pechgraben mudslide by the Geological Survey of Austria (LAMOND network including permanent ERT, GPS, piezometers, soil temperature/humidity and photomonitoring) is expected as a better basis for joint interpretation of seismic source processes. Seismic data are acquired by small-aperture (< 30 m) sparse seismic arrays. Potential events are recognized by frequency-time signatures in sonograms, where sonograms are spectrograms featuring a frequency-dependant noise adaptation that enhance the display of weak signal energy down to the noise threshold. Further signal evaluation follows an interactive scheme where semi-automated beam forming method enables for approximate source location. Three seismic arrays where deployed at Pechgraben in October 2015 for an eight days feasibility study. About 200 seismic signals potentially triggered by the landslide were manually picked on night-time measurements. Target signals occur in tremor-like sequences and have duration within 1 - 8 seconds. Local magnitudes are calibrated down to ML -1.5 (Wood-Anderson amplitude ≈ 0.1 μm in 100 m distance). Observed waveforms display high degree of similarity with seismic signals catalogued at other soft-rock landslides suggesting that a general typology of seismic source processes could be established for creeping soft-rock instabilities with potential further implications in landslide mitigation and forecasting.

  8. Easy-to-use, general, and accurate multi-Kinect calibration and its application to gait monitoring for fall prediction.

    PubMed

    Staranowicz, Aaron N; Ray, Christopher; Mariottini, Gian-Luca

    2015-01-01

    Falls are the most-common causes of unintentional injury and death in older adults. Many clinics, hospitals, and health-care providers are urgently seeking accurate, low-cost, and easy-to-use technology to predict falls before they happen, e.g., by monitoring the human walking pattern (or "gait"). Despite the wide popularity of Microsoft's Kinect and the plethora of solutions for gait monitoring, no strategy has been proposed to date to allow non-expert users to calibrate the cameras, which is essential to accurately fuse the body motion observed by each camera in a single frame of reference. In this paper, we present a novel multi-Kinect calibration algorithm that has advanced features when compared to existing methods: 1) is easy to use, 2) it can be used in any generic Kinect arrangement, and 3) it provides accurate calibration. Extensive real-world experiments have been conducted to validate our algorithm and to compare its performance against other multi-Kinect calibration approaches, especially to show the improved estimate of gait parameters. Finally, a MATLAB Toolbox has been made publicly available for the entire research community.

  9. Monitoring and Analysis of Transient Pore Water Pressures in Large Suspended Rock Slides near Poschiavo, CH

    NASA Astrophysics Data System (ADS)

    de Palézieux, Larissa; Loew, Simon; Zwahlen, Peter

    2016-04-01

    Many mountain slopes in the Alps exhibit large compound rock slides or Deep Seated Gravitational Slope Deformations. Due to the basal rupture plane geometry and the cumulative displacement magnitude such landslide bodies are often strongly deformed, highly fractured and - at least locally - very permeable. This can lead to high infiltration rates and low phreatic groundwater tables. This is also the situation in the studied mountain slopes southwest of Poschiavo, where large suspended rockslides occur, with very little surface runoff at high elevations, and torrents developing only at the elevation of the basal rupture planes. Below the landslide toes, at altitudes below ca. 1700 m a.s.l., groundwater appears forming spring lines or distributed spring clusters. Within the scope of the design of a hydropower pump storage plant in the Poschiavo valley by Lagobianco SA (Repower AG), numerous cored and deep boreholes (of 50 to 300 m depth) have been drilled along the planned pressure tunnel alignement at elevations ranging from 963 to 2538 m a.s.l. in the years 2010 and 2012. In several boreholes Lugeon and transient pressure tests were executed and pore water pressure sensors installed in short monitoring sections at various depths. Most of these boreholes intersect deep rockslides in crystalline rocks and limestones, showing highly fragmented rock masses and cohesionless cataclastic shear zones of several tens of meters thickness. This study explores these borehole observations in landslides and adjacent stable slopes and links them to the general hydrologic and hydrogeologic framework. The analysis of the pore water pressure data shows significant variability in seasonal trends and short-term events (from snow melt and summer rain storms) and remarkable pressure differences over short horizontal and vertical distances. This reflects rock mass damage within landslide bodies and important sealing horizons at their base. Based on water balances, the estimated effective

  10. Monitoring Fracture Propagation in a Soft Rock (Neapolitan Tuff) Using Acoustic Emissions and Digital Images

    NASA Astrophysics Data System (ADS)

    Hall, Stephen A.; Sanctis, Fiorenza De; Viggiani, Gioacchino

    2006-10-01

    Sudden and unexpected collapses of underground cavities below the city of Naples (Italy) represent a serious safety hazard. The collapses occur due to the detachment of large blocks from the cavity roofs, walls and pillars, often a long time after the original quarry excavation has been completed. It is recognised that existing discontinuities, e.g., fractures, play an important role in the failure process by inducing local stress-concentrations and reducing the overall material strength. The larger fractures, which ultimately lead to collapse occur through interaction, propagation and coalescence of these discontinuities. This paper presents recent results of experiments carried out on natural, dry specimens of Neapolitan fine-grained tuff to investigate the mechanisms involved in sample failure. A better understanding of fracture development and rock bridge behaviour is gained through a combination of AE and photographic monitoring in an experimental program considering samples with artificial pre-existing heterogeneities, which simulate the in situ discontinuities. For a range of rock bridge geometries the mechanisms and timing of different stages of the failure process are identified and characterised. The results show that, in general, a classical description of failure, for samples without artificial flaws or with only a single flaw, is followed: (1) crack closure; (2) linear stress-strain response and crack initiation with stable crack growth; (3) crack damage and unstable crack growth leading to failure. For samples with two artificial pre-existing flaws the third phase is split into two parts and failure of the sample occurs only after both the unstable propagation of external wing cracks and coalescence of the internal cracks in the bridge. In terms of the timing and duration of each phase, it is seen that phases 1 and 2 have little dependence on the flaw configuration but phase 3 seems to depend directly on this. In particular the angle in rock bridge

  11. Real Time Dust Fall Monitor (RTDFM). [for application to space shuttle

    NASA Technical Reports Server (NTRS)

    Claysmith, C. R.

    1976-01-01

    A prototype ultraviolet optical instrument designed and developed to monitor 300 level surface cleanliness is described. Size, weight, sensitivity, and simplicity design parameters were satisfied. Tests were conducted with various configurations of the detector array and sample surfaces. Circuit schematics are included. It is shown that output drift is due to effective lamp intensity variations. The instrument is intended to be a part of the integrated environmental contamination monitor of the space shuttle.

  12. Electromagnetic monitoring of stimulated hot dry rock systems - modelling and examples from South Australia

    NASA Astrophysics Data System (ADS)

    Thiel, S.; Peacock, J.; Heinson, G. S.; Reid, P.

    2011-12-01

    Realization of enhanced geothermal systems (EGS) prescribes the need for novel technology to monitor the created reservoir. Conventionally, micro-earthquake arrays are used to monitor seismic events associated with the postulated pressure front of the injected fluid. We propose the additional use of the magnetotelluric (MT) technique which is directly sensitive to elevated electrical conductivity allowing mapping the conductive injected fluid in the subsurface. MT is a passive electromagnetic method that characterizes geoelectric structure by measuring the Earth's response to natural magnetic fields. Measuring the MT response before, during and after fluids are injected into the reservoir provides a tool to delineate reservoir boundaries at depth. This is important as electrical conductivity can change by a few orders of magnitude making a conductive fluid in resistive host rock a viable MT target at depth. Three-dimensional MT forward modelling illustrates the dependence of reservoir size and depth as well as the dampening effect of a conductive overburden, such as a sedimentary basin. Forward modelling suggests changes in the MT response of a proposed reservoir at 3.5km depth will be on the order of a few percent, advising an accurate and precise prior data set is collected. A test case from Paralana, South Australia will be presented illustrating results of MT responses before and after fluids are injected as well as time-lapse transfer function variability during the injection.

  13. Hanford Reach Fall Chinook Redd Monitoring Report for Calendar Year 2013

    SciTech Connect

    Lindsey, Cole T.; Nugent, John J.

    2014-02-10

    The U.S. Department of Energy, Richland Operations Office (DOE-RL) conducts ecological monitoring on the Hanford Site to collect and track data needed to ensure compliance with an array of environmental laws, regulations, and policies governing DOE activities. Ecological monitoring data provide baseline information about the plants, animals, and habitat under DOE-RL stewardship at Hanford required for decision-making under the National Environmental Policy Act (NEPA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The Hanford Site Comprehensive Land Use Plan (CLUP, DOE/EIS-0222-F) which is the Environmental Impact Statement for Hanford Site activities, helps ensure that DOE-RL, its contractors, and other entities conducting activities on the Hanford Site are in compliance with NEPA.

  14. Microcracking during triaxial deformation of porous rocks monitored by changes in rock physical properties, I. Elastic-wave propagation measurements on dry rocks

    NASA Astrophysics Data System (ADS)

    Ayling, Mark R.; Meredith, Philip G.; Murrell, Stanley A. F.

    1995-05-01

    We present results from two series of triaxial deformation experiments performed on "dry" samples of two sandstones (Darley Dale and Gosford) carried out at confining pressures from 25 MPa to 200 MPa. Over this pressure range the mode of failure in both these sandstones passes from localized brittle failure with a clear through-going fault to distributed cataclastic flow. During these experiments, stress, strain, compressional-wave velocity ( VP) and shear-wave velocity ( VS) measurements were made simultaneously in the direction of the maximum principal compressive loading axis. Initial application of the hydrostatic confining pressure causes both VP and VS to increase, and upon raising the axial stress above the confining pressure both velocities increase further at first (generally by only a few percent), but then decrease as dilatant crack growth commences. During dilatancy, VS decreases proportionately more than VP, and this decrease is generally of the order of 10-15%. These velocity measurements allow changes in rock physical properties to be calculated along with the axial and transverse crack volume density parameters, ɛX and ɛZ. The results from two selected tests are analysed in detail. These tests were chosen because they exhibit; (a) typical brittle shear failure, and (b) typical ductile cataclastic flow, respectively. The full interrogating elastic waveforms were also recorded during testing, and these have been used to calculate the seismic quality factors QP and QS. To our knowledge, this is the first time this has been reported for rock samples undergoing triaxial deformation. The changes in Q values generally exhibit similar trends to those observed in the velocity measurements, but the percentage changes in Q are an order of magnitude greater, suggesting that this parameter is a more sensitive measure of dilatant crack damage. The measurements on dry rock samples reported here provide the basis for comparison with measurments of changes in

  15. Real-time oil-saturation monitoring in rock cores with low-field NMR.

    PubMed

    Mitchell, J; Howe, A M; Clarke, A

    2015-07-01

    Nuclear magnetic resonance (NMR) provides a powerful suite of tools for studying oil in reservoir core plugs at the laboratory scale. Low-field magnets are preferred for well-log calibration and to minimize magnetic-susceptibility-induced internal gradients in the porous medium. We demonstrate that careful data processing, combined with prior knowledge of the sample properties, enables real-time acquisition and interpretation of saturation state (relative amount of oil and water in the pores of a rock). Robust discrimination of oil and brine is achieved with diffusion weighting. We use this real-time analysis to monitor the forced displacement of oil from porous materials (sintered glass beads and sandstones) and to generate capillary desaturation curves. The real-time output enables in situ modification of the flood protocol and accurate control of the saturation state prior to the acquisition of standard NMR core analysis data, such as diffusion-relaxation correlations. Although applications to oil recovery and core analysis are demonstrated, the implementation highlights the general practicality of low-field NMR as an inline sensor for real-time industrial process control.

  16. Use of a digital model to evaluate hydrogeologic controls on groundwater flow in a fractured rock aquifer at Niagara Falls, New York, U.S.A.

    USGS Publications Warehouse

    Maslia, M.L.; Johnston, R.H.

    1984-01-01

    The Hyde Park landfill is a 15-acre (6.1 ha) chemical waste disposal site located north of Niagara Falls, New York. Underlying the site in descending order are: (1) low-permeability glacial till and lacustrine deposits; (2) a moderately permeable fractured rock aquifer - the Lockport Dolomite; and (3) a low-permeability unit - the Rochester Shale. The site is bounded on three sides by groundwater drains; the Niagara River gorge, the Niagara Power Project canal, and the Niagara Power Project buried conduits. The mechanism by which groundwater moves through fractured rocks underlying a hazardous waste site was investigated using a digital simulation approach. Three hypotheses were tested related to flow in the fractured rocks underlying Hyde Park landfill. For this purpose we used a Galerkin finite-element approximation to solve a saturated-unsaturated flow equation. A primary focus was to investigate anisotropy in the Lockport Dolomite, that is the effectiveness of horizontal (bedding) joints vs. vertical joints as water-transmitting openings. Three hydrogeologic scenarios were set up - each with prescribed limits on the hydrologic parameters. Scenario 1 specified strongly anisotropic conditions in the Lockport Dolomite (horizontal hydraulic conductivity along bedding joints exceeds vertical conductivity by 2-3 orders of magnitude), uniform areal recharge (5 in. yr.-1 or 12.7 cm yr.-1) except at the landfill where there is no recharge, and no flow through the base of the Rochester Shale. Scenario 2 also specified strongly anisotropic conditions in the Lockport; however, areal recharge was 6 in. yr.-1 (15.2 cm yr.-1) except at the landfill where the recharge was 2 in. yr.-1 (5.1 cm yr.-1), and outflow from the Rochester occurred. Scenario 3 specified isotropic conditions (that is, permeability along horizontal and vertical joints is the same in the Lockport Dolomite), recharge rates were the same as in scenario 2 and outflow through Rochester occurred. Scenario 2

  17. Use of a digital model to evaluate hydrogeologic controls on groundwater flow in a fractured rock aquifer at Niagara Falls, New York, U.S.A.

    NASA Astrophysics Data System (ADS)

    Maslia, Morris L.; Johnston, Richard H.

    1984-12-01

    The Hyde Park landfill is a 15-acre (6.1 ha) chemical waste disposal site located north of Niagara Falls, New York. Underlying the site in descending order are: (1) low-permeability glacial till and lacustrine deposits; (2) a moderately permeable fractured rock aquifer — the Lockport Dolomite; and (3) a low-permeability unit — the Rochester Shale. The site is bounded on three sides by groundwater drains; the Niagara River gorge, the Niagara Power Project canal, and the Niagara Power Project buried conduits. The mechanism by which groundwater moves through fractured rocks underlying a hazardous waste site was investigated using a digital simulation approach. Three hypotheses were tested related to flow in the fractured rocks underlying Hyde Park landfill. For this purpose we used a Galerkin finite-element approximation to solve a saturated-unsaturated flow equation. A primary focus was to investigate anisotropy in the Lockport Dolomite, that is the effectiveness of horizontal (bedding) joints vs. vertical joints as water-transmitting openings. Three hydrogeologic scenarios were set up — each with prescribed limits on the hydrologic parameters. Scenario 1 specified strongly anisotropic conditions in the Lockport Dolomite (horizontal hydraulic conductivity along bedding joints exceeds vertical conductivity by 2-3 orders of magnitude), uniform areal recharge (5 in. yr. -1 or 12.7 cm yr. -1) except at the landfill where there is no recharge, and no flow through the base of the Rochester Shale. Scenario 2 also specified strongly anisotropic conditions in the Lockport; however, areal recharge was 6 in. yr. -1 (15.2 cm yr. -1) except at the landfill where the recharge was 2 in. yr. -1 (5.1 cm yr. -1), and outflow from the Rochester occurred. Scenario 3 specified isotropic conditions (that is, permeability along horizontal and vertical joints is the same in the Lockport Dolomite), recharge rates were the same as in scenario 2 and outflow through Rochester occurred

  18. Demonstration of a Fractured Rock Geophysical Toolbox (FRGT) for Characterization and Monitoring of DNAPL Biodegradation in Fractured Rock Aquifers

    DTIC Science & Technology

    2015-09-29

    parameters controlling mass transfer . For the amendment injection and DNAPL monitoring component of the toolkit, this project set out to investigate the...capacitance, and thus the properties of fluid-grain boundaries in porous media . Finally, it is possible to simply measure an open circuit potential of an...from the northeastern US. The team has also strived to take advantage of tech transfer activities via social media as promoted by ESTCP officials

  19. Using monitoring and modeling to define the hazard posed by the reactivated Ferguson rock slide, Merced Canyon, California

    USGS Publications Warehouse

    De Graff, Jerome V.; Gallegos, Alan J.; Reid, Mark E.; Lahusen, Richard G.; Denlinger, Roger P.

    2015-01-01

    Rapid onset natural disasters such as large landslides create a need for scientific information about the event, which is vital to ensuring public safety, restoring infrastructure, preventing additional damage, and resuming normal economic activity. At the same time, there is limited data available upon which to base reliable scientific responses. Monitoring movement and modeling runout are mechanisms for gaining vital data and reducing the uncertainty created about a rapid onset natural disaster. We examine the effectiveness of this approach during the 2006 Ferguson rock slide disaster, which severed California Highway 140. Even after construction of a bypass restoring normal access to the community of El Portal, CA and a major entrance to Yosemite National Park, significant scientific questions remained. The most important for the affected public and emergency service agencies was the likelihood that access would again be severed during the impending rainy season and the possibility of a landslide dam blocking flow in the Merced River. Real-time monitoring of the Ferguson rock slide yielded clear information on the continuing movement of the rock slide and its implications for emergency response actions. Similarly, simulation of runout deposits using a physically based model together with volumes and slope steepness information demonstrated the conditions necessary for a landslide dam-forming event and the possible consequences of such an event given the dimensions of potential rock slide deposits.

  20. Activity Monitoring and Heart Rate Variability as Indicators of Fall Risk: Proof-of-Concept for Application of Wearable Sensors in the Acute Care Setting.

    PubMed

    Razjouyan, Javad; Grewal, Gurtej Singh; Rishel, Cindy; Parthasarathy, Sairam; Mohler, Jane; Najafi, Bijan

    2017-03-02

    Growing concern for falls in acute care settings could be addressed with objective evaluation of fall risk. The current proof-of-concept study evaluated the feasibility of using a chest-worn sensor during hospitalization to determine fall risk. Physical activity and heart rate variability (HRV) of 31 volunteers admitted to a 29-bed adult inpatient unit were recorded using a single chest-worn sensor. Sensor data during the first 24-hour recording were analyzed. Participants were stratified using the Hendrich II fall risk assessment into high and low fall risk groups. Univariate analysis revealed age, daytime activity, nighttime side lying posture, and HRV were significantly different between groups. Results suggest feasibility of wearable technology to consciously monitor physical activity, sleep postures, and HRV as potential markers of fall risk in the acute care setting. Further study is warranted to confirm the results and examine the efficacy of the proposed wearable technology to manage falls in hospitals. [Journal of Gerontological Nursing, xx(x), xx-xx.].

  1. Challenges within Monitoring and Risk-Oriented Analysis of Precipitation- and Hydraulic- Coupled Catastrophic Rock- and Soil-Collapses at Urban and Infrastructural Alpine Areas

    NASA Astrophysics Data System (ADS)

    Scheikl, M.

    2007-05-01

    Within the past years we investigated several catastrophic soil- and rock-slides along infrastructural and urban areas which are coupled to extreme weather phenomena. This contribution shall show examples, triggered by catastrophic rain-falls and anthropogenic influence. Further, the stress-field between the compliance with legal and economical requirements and the rising frequency of weather induced events shall be discussed from the geoengineers point of view. In the past, engineers were strictly confronted with the detailed geological and geomechanical or numerical analysis of the slope failures. Since the past role of the engineer as inviolable decision leader is increasingly weakened, due to economic control obligations - mostly operated from the far desk - new ways of conviction work had to be developed as well as effective forecasting and monitoring instruments. For this reason the requirement to engineers, regarding the ability to work multidisciplinary and to find more exact models, is risen, which is to be seen positively. In order to fulfill the increasing justification-requires when planning counter measures, several technical and economical aspects are to be described quantitatively now. This quantitative description is the basis for risk- analysis, which has to contain beside other aspects following: a) The shift of the probability of extreme events b) The expected harm at humans at the scenario put to reason c) The expected damage at structures d) The expected super-ordinate economical harm e) The expected costs of counter-measure variants f) The variant related residual risk, expressed in probable occurring costs While the description of the first aspect a) is mainly a geotechnical challenge, which is connected to very detailed knowledge of the slope-failure characteristic, triggering mechanisms as well as related historical and future meteorological data, the aspects c) and e) concern exact technical cost investigations. The real challenges are

  2. Sea state monitoring over Socotra Rock (Ieodo) by dual polarization SAR image analysis

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Kim, J.; Yun, H.; yun, H.

    2013-12-01

    The application SAR in sea state monitoring have been conducted in the large number of fields such as the vessel tracing using the wake in SAR amplitude, the measurement of sea wave height and the oil spill detection. The true merit of SAR application in sea state monitoring is the full independence from the climate conditions. Hence, it is highly useful to secure safety of the anthropogenic activities in ocean and the understanding of the marine environment. Especially the dual and full polarization modes of new L band and X band SAR such as Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR)'s Fine Beam double Polarization (FDB) and Polarimetry mode (PLR) and terraSAR-X polarization mode provided innovative means to extract sea state information exploiting the different amplitude and phase angle responses by electromagnetic and sea wave interactions. Thus a sample projects for mining the maximum possible sea state information from the ALOS PLASAR FDB SAR/InSAR pairs compared with the in-suit observation of sea state is being conducted. Test site was established over Socotra Rock (Ieodo in Korean), which is located at the Western Sea of Korea. At first, it aimed the measurement of sea waves using ALOS PLASAR multi-polarization images and its doppler-shift analysis. Together with sea state monitoring, auxiliary data analyses to combine the sea state outputs with the other in-orbital sensing image and non image information to trace the influence of sea states in the marine environment are actively undergoing. For instance, MERIS chlorophyll-a products are under investigation to identify the correlation with sea state. However, an significant obstacles to apply SAR interpretation scheme for mining sea state is the temporal gap between SAR image acquisitions in spite of the improved revising time of contemporary in-orbital SAR sensors. To tackle this problem, we are also introducing the multi view angle optical sensor

  3. A Long-term Reach-Scale Monitoring Network for Riparian Evapotranspiration, Rock Creek, Kansas

    NASA Astrophysics Data System (ADS)

    Rajaram, H.; Solis, J. A.; Whittemore, D. O.; Butler, J. J.; Reboulet, E.; Knobbe, S.; Dealy, M.

    2011-12-01

    Riparian evapotranspiration (RET) is an important component of basin-wide evapotranspiration (ET), especially in subhumid to semi-arid regions, with significant impact on water management and conservation. In narrow riparian zones, typical of much of the subhumid to semi-arid U.S., direct measurement of RET by eddy correlation is precluded by the limited fetch distance of riparian vegetation. Alternative approaches based on water balance analyses have a long history, but their accuracy is not well understood. Factors such as heterogeneity in soil properties and root distributions, and sparse measurements, introduce uncertainties in RET estimates. As part of a larger effort aimed at improving understanding of basin-wide RET using scaling theories, we installed a continuous monitoring system for water balance estimation at the scale of a single (~100 m long) reach along Rock Creek in the Whitewater Basin in central Kansas. The distinguishing features of this site include a vadose zone with fine-grained soils underlain by a phreatic zone of coarse gravel embedded in clay, overlying karst bedrock. Across the width (~40 m) of the riparian zone, we installed one transect of four wells screened at the bottom of the alluvium (6-7 m depth), each accompanied by a soil moisture profiler with capacitance sensors at 4 vertical levels above the local water-table elevation (~2.5 m depth) and a shallow well screened just below the water table. All wells were instrumented with pressure transducers for monitoring water levels. Additional sets of all sensors were installed at the upstream and downstream ends of the study reach. Initial results from the monitoring network suggest significant complexities in the behavior of the subsurface system at the site, including a high degree of heterogeneity. All deep wells show a rapid response to streamflow variations and nearby pumping. However, the shallow water-table wells do not respond rapidly to either. Both the shallow wells and soil

  4. GPR monitoring of rock mass stability in selected post-mining region in Poland

    NASA Astrophysics Data System (ADS)

    Golebiowski, T.

    2012-04-01

    were carried out in the region of already existing sinkhole (with the diameter of about 15m and the depth of about 10m) in order to detect the distribution of dangerous fractures around this sinkhole. As the results of GPR research has shown, fractured zones in this site developed quickly as a result of superimposition of fractures induced by mining activity and the processes of suffusion and congelifraction. GPR monitoring of the rock mass stability in mining and post-mining areas is very important because sinkholes threaten the live of people and stability of structures and installations. As it was shown in the paper, the GPR method gives very good results for the prediction of sinkholes creation if it is applied in 4D mode. A limitation of this method is the depth penetration, i.e. a dozen or so meters with resolution which allows to detect fractures and strong attenuation of electromagnetic waves in the clay formations. The research was financed from the funds of National Science Center, on the basis of agreement no. UMO-2011/01/B/ST7/06178 and decision no. DEC-2011/01/B/ST7/06178.

  5. How aggressive are coastal cliff environments? Monitoring micro-environmental conditions on an actively eroding rock cliff.

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    Despite their widespread occurrence, the behaviour of coastal rock cliffs, and in particular the balance between the marine and subaerial conditions that promote erosion, is poorly understood. This is mainly due to a lack of direct, quantitative data on process and response in this type of environment. This paper investigates how near-cliff environmental processes can be associated with the occurrence of rockfalls, which we argue contribute the majority of material lost from coastal cliffs. A detailed recent history of rockfall volumes, dating back to 2003, has been collected using repeat terrestrial laser scans of a 70 m high cliff section on the North Yorkshire coast, UK. This dataset is complimented with a bespoke environmental monitoring system installed upon the cliff face, which allows the influence of weathering and erosion processes on the magnitude and frequency of rockfalls to be analysed. This system is comprised of three instrument clusters at nodes that correspond to three main lithological units of the cliff, hard wired to a communications unit at the top of the cliff face. Data is collected on air temperature, humidity, irradiance, wind and precipitation. Within the near surface of the rock mass we also measure temperature, rock moisture, surface wetness and strain, to allow the direct physical response of the rock to be quantified. The cliff (local) environment monitoring system demonstrates that the rock undergoes significantly greater variability than can be identified from more generic regional weather and tide datasets, predominantly as a function of the angular geometry of the cliff face, resulting in rapid gradients of change. For example, daily variations in temperature and moisture can be seen to have a significant and direct effect on the strain responses of the rock. We seek to establish this as a long-term dataset, to provide a new quantitative assessment of the links between regional and hinterland weather conditions and those found on

  6. An online one class support vector machine-based person-specific fall detection system for monitoring an elderly individual in a room environment.

    PubMed

    Yu, Miao; Yu, Yuanzhang; Rhuma, Adel; Naqvi, Syed Mohsen Raza; Wang, Liang; Chambers, Jonathon A

    2013-11-01

    In this paper, we propose a novel computer vision-based fall detection system for monitoring an elderly person in a home care, assistive living application. Initially, a single camera covering the full view of the room environment is used for the video recording of an elderly person's daily activities for a certain time period. The recorded video is then manually segmented into short video clips containing normal postures, which are used to compose the normal dataset. We use the codebook background subtraction technique to extract the human body silhouettes from the video clips in the normal dataset and information from ellipse fitting and shape description, together with position information, is used to provide features to describe the extracted posture silhouettes. The features are collected and an online one class support vector machine (OCSVM) method is applied to find the region in feature space to distinguish normal daily postures and abnormal postures such as falls. The resultant OCSVM model can also be updated by using the online scheme to adapt to new emerging normal postures and certain rules are added to reduce false alarm rate and thereby improve fall detection performance. From the comprehensive experimental evaluations on datasets for 12 people, we confirm that our proposed person-specific fall detection system can achieve excellent fall detection performance with 100% fall detection rate and only 3% false detection rate with the optimally tuned parameters. This work is a semiunsupervised fall detection system from a system perspective because although an unsupervised-type algorithm (OCSVM) is applied, human intervention is needed for segmenting and selecting of video clips containing normal postures. As such, our research represents a step toward a complete unsupervised fall detection system.

  7. Using remotely sensed imagery and GIS to monitor and research salmon spawning: A case study of the Hanford Reach fall chinook (Oncorhynchus Tshawytscha)

    SciTech Connect

    RH Visser

    2000-03-16

    The alteration of ecological systems has greatly reduced salmon populations in the Pacific Northwest. The Hanford Reach of the Columbia River, for example, is a component of the last ecosystem in eastern Washington State that supports a relatively healthy population of fall chinook salmon ([Oncorhynchus tshawytscha], Huntington et al. 1996). This population of fall chinook may function as a metapopulation for the Mid-Columbia region (ISG 1996). Metapopulations can seed or re-colonize unused habitat through the mechanism of straying (spawning in non-natal areas) and may be critical to the salmon recovery process if lost or degraded habitat is restored (i.e., the Snake, Upper Columbia, and Yakima rivers). For these reasons, the Hanford Reach fall chinook salmon population is extremely important for preservation of the species in the Columbia River Basin. Because this population is important to the region, non-intrusive techniques of analysis are essential for researching and monitoring population trends and spawning activities.

  8. Investigation of Non-Linear Dynamics of the Rock Massive,Using Seismological Catalogue data and Induction Electromagnetic Monitoring Data in a Rock Burst Mine.

    NASA Astrophysics Data System (ADS)

    Hachay, O. A.; Khachay, O. Y.; Klimko, V. K.; Shipeev, O. V.

    2012-04-01

    Geological medium is an open dynamical system, which is influenced on different scales by natural and man-made impacts, which change the medium state and lead as a result to a complicated many ranked hierarchic evolution. That is the subject of geo synergetics. Paradigm of physical mesomechanics, which was advanced by academician Panin V.E. and his scientific school, which includes the synergetic approach is a constructive method for research and changing the state of heterogenic materials [1]. That result had been obtained on specimens of different materials. In our results of research of no stationary geological medium in a frame of natural experiments in real rock massifs, which are under high man-made influence it was shown, that the state dynamics can be revealed with use synergetics in hierarchic medium. Active and passive geophysical monitoring plays a very important role for research of the state of dynamical geological systems. It can be achieved by use electromagnetic and seismic fields. Our experience of that research showed the changing of the system state reveals on the space scales and times in the parameters, which are linked with the peculiarities of the medium of the second or higher ranks [2-5]. Results of seismological and electromagnetic information showed the mutual additional information on different space-time levels of rock massive state, which are energetic influenced by explosions, used in mining technology. It is revealed a change of nonlinearity degree in time of the massive state by active influence on it. The description of massive movement in a frame of linear dynamical system does not satisfy the practical situation. The received results are of great significance because for the first time we could find the coincidences with the mathematical theory of open systems and experimental natural results with very complicated structure. On that base we developed a new processing method for the seismological information which can be used in

  9. Improved characterization, monitoring and instability assessment of high rock faces by integrating TLS and GB-InSAR

    NASA Astrophysics Data System (ADS)

    Bianchetti, Matteo; Agliardi, Federico; Villa, Alberto; Battista Crosta, Giovanni; Rivolta, Carlo

    2015-04-01

    Rockfall risk analysis require quantifying rockfall onset susceptibility and magnitude scenarios at source areas, and the expected rockfall trajectories and related dynamic quantities. Analysis efforts usually focus on the rockfall runout component, whereas rock mass characterization and block size distribution quantification, monitoring and analysis of unstable rock volumes are usually performed using simplified approaches, due to technological and site-specific issues. Nevertheless, proper quantification of rock slope stability and rockfall magnitude scenarios is key when dealing with high rock walls, where widespread rockfall sources and high variability of release mechanisms and block volumes can result in excessive modelling uncertainties and poorly constrained mitigation measures. We explored the potential of integrating field, remote sensing, structural analysis and stability modelling techniques to improve hazard assessment at the Gallivaggio sanctuary site, a XVI century heritage located along the State Road 36 in the Spluga Valley (Italian Central Alps). The site is impended by a subvertical cliff up to 600 m high, made of granitic orthogneiss of the Truzzo granitic complex (Tambo Nappe, upper Pennidic domain). The rock mass is cut by NNW and NW-trending slope-scale structural lineaments and by 5-6 fracture sets with variable spatial distribution, spacing and persistence, which bound blocks up to tens of cubic meters and control the 3D slope morphology. The area is characterised by widespread rock slope instability from rockfalls to massive failures. Although a 180 m long embankment was built to protect the site from rockfalls, concerns remain about potential large unstable rock volumes or flyrocks projected by the widely observed impact fragmentation of stiff rock blocks. Thus, the authority in charge started a series of periodical GB-InSAR monitoring surveys using LiSALabTM technology (12 surveys in 2011-2014), which outlined the occurrence of unstable

  10. k-t Acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs

    NASA Astrophysics Data System (ADS)

    Xiao, Dan; Balcom, Bruce J.

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems.

  11. Simulation and field monitoring of moisture in alpine rock walls during freeze-thaw events

    NASA Astrophysics Data System (ADS)

    Rode, Matthias; Sass, Oliver

    2013-04-01

    Detachment of rock fragments from alpine rockwalls is mainly assigned to frost weathering. However, the actual process of frost weathering as well as the contribution of further weathering processes (e.g. hydration, thermal fatigue) is poorly understood. Rock moisture distribution during freeze-thaw events is key to understanding weathering. For this purpose, different measuring systems were set up in two study areas (Dachstein - permafrost area (2700m a.s.l.) and Gesäuse - non permafrost area (900m a.s.l.), Styria, Austria) within the framework of the research project ROCKING ALPS (FWF-P24244). We installed small-scale 2D-geoelectric survey lines in north and in south facing rockwalls, supplemented by high resolution temperature and moisture sensors. Moisture is determined by means of resistivity measurements which are difficult to calibrate, but provide good time series. Additional novel moisture sensors were developed which use the heat capacity of the surrounding rock as a proxy of water content. These sensors give point readings from a defined depth and are independent from soluble salt contents. Pore water pressure occurring during freeze-thaw events is recorded by means of pressure transducers (piezometers). First results from the Dachstein show that short term latent heat effects during the phase change have crucial influence on the moisture content. These results are cross-checked by simulation calculations. Based on meteorologic and lithologic input values, the simulation routine calculates, in an iterative procedure, the hourly energy and water transport at different depths, the latter in the liquid and in the vapor phase. The calculated profile lines and chronological sequences of rock moisture allow - in combination with temperature data - to detect possible periods of active weathering. First simulations from the Gesäuse show that maximum values of pore saturation occur from May to September. The thresholds of the "classical" frost shattering theory

  12. 180. Photocopy of Photograph, Twin Falls Canal Company. E. Pettygro, ...

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

    180. Photocopy of Photograph, Twin Falls Canal Company. E. Pettygro, Photographer, date unknown. BLASTING TWIN FALLS CANAL, TWIN FALLS COUNTY; BLASTING COTTONWOOD AREA TO REPLACE FLUME BY RUNNING HIGH LINE THROUGH SOLID ROCK. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  13. Rockfall monitoring by Terrestrial Laser Scanning - case study of the basaltic rock face at Castellfollit de la Roca (Catalonia, Spain)

    NASA Astrophysics Data System (ADS)

    Abellán, A.; Vilaplana, J. M.; Calvet, J.; García-Sellés, D.; Asensio, E.

    2011-03-01

    This case study deals with a rock face monitoring in urban areas using a Terrestrial Laser Scanner. The pilot study area is an almost vertical, fifty meter high cliff, on top of which the village of Castellfollit de la Roca is located. Rockfall activity is currently causing a retreat of the rock face, which may endanger the houses located at its edge. TLS datasets consist of high density 3-D point clouds acquired from five stations, nine times in a time span of 22 months (from March 2006 to January 2008). The change detection, i.e. rockfalls, was performed through a sequential comparison of datasets. Two types of mass movement were detected in the monitoring period: (a) detachment of single basaltic columns, with magnitudes below 1.5 m3 and (b) detachment of groups of columns, with magnitudes of 1.5 to 150 m3. Furthermore, the historical record revealed (c) the occurrence of slab failures with magnitudes higher than 150 m3. Displacements of a likely slab failure were measured, suggesting an apparent stationary stage. Even failures are clearly episodic, our results, together with the study of the historical record, enabled us to estimate a mean detachment of material from 46 to 91.5 m3 year-1. The application of TLS considerably improved our understanding of rockfall phenomena in the study area.

  14. Flowpath independent monitoring of reductive dechlorination potential in a fractured rock aquifer

    USGS Publications Warehouse

    Bradley, P.M.; Lacombe, P.J.; Imbrigiotta, T.E.; Chapelle, F.H.; Goode, D.J.

    2009-01-01

    The flowpath dependent approaches that are typically employed to assess biodegradation of chloroethene contaminants in unconsolidated aquifers are problematic in fractured rock settings, due to difficulties defining discrete groundwater flowpaths in such systems. In this study, the variation in the potential for chloroethene biodegradation with depth was evaluated in a fractured rock aquifer using two flowpath independent lines of field evidence: (1) the presence of the three biochemical prerequisites [electron donor(s), chloroethene electron acceptor(s), and chlororespiring microorganism(s)] for efficient chloroethene chlororespiration and (2) the in situ accumulation of chloroethene reductive dechlorination daughter products. The validity of this approach was assessed by comparing field results with the results of [1, 2- 14C] cis-DCE microcosm experiments. Microcosms were prepared with depth-specific core material, which was crushed and emplaced in discrete packer intervals for 1 year to allow colonization by the indigenous microbial community. Packer intervals characterized by significant electron donor concentrations, elevated numbers of chlororespiring microorganisms, and high reductive dechlorination product to parent contaminant ratios correlated well with the production of 14C-labeled reductive dechlorination products in the microcosm experiments. These results indicate that, in the absence of information on discrete groundwater flowpaths, a modified approach emphasizing flowpath independent lines of evidence can provide insight into the temporal and spatial variability of contaminant biodegradation in fractured rock systems. ?? 2009 National Ground Water Association.

  15. Impedance-Based Pre-Stress Monitoring of Rock Bolts Using a Piezoceramic-Based Smart Washer—A Feasibility Study

    PubMed Central

    Wang, Bo; Huo, Linsheng; Chen, Dongdong; Li, Weijie; Song, Gangbing

    2017-01-01

    Pre-stress degradation or looseness of rock bolts in mining or tunnel engineering threatens the stability and reliability of the structures. In this paper, an innovative piezoelectric device named a “smart washer” with the impedance method is proposed with the aim of developing a real-time device to monitor the pre-stress level of rock bolts. The proposed method was verified through tests on a rock bolt specimen. By applying high-frequency sweep excitations (typically >30 kHz) to the smart washer that was installed on the rock bolt specimen, we observed that the variation in impedance signatures indicated the rock bolt pre-stress status. With the degradation of rock bolt pre-stress, the frequency in the dominating peak of the real part of the electrical impedance signature increased. To quantify the effectiveness of the proposed technique, a normalized root mean square deviation (RMSD) index was developed to evaluate the degradation level of the rock bolt pre-stress. The experimental results demonstrated that the normalized RMSD-based looseness index, which was computed from the impedance value detected by the “smart washer”, increased with loss of the pre-stress of the rock bolt. Therefore, the proposed method can effectively detect the degradation of rock bolt pre-stress, as demonstrated by experiments. PMID:28134811

  16. Impedance-Based Pre-Stress Monitoring of Rock Bolts Using a Piezoceramic-Based Smart Washer-A Feasibility Study.

    PubMed

    Wang, Bo; Huo, Linsheng; Chen, Dongdong; Li, Weijie; Song, Gangbing

    2017-01-27

    Pre-stress degradation or looseness of rock bolts in mining or tunnel engineering threatens the stability and reliability of the structures. In this paper, an innovative piezoelectric device named a "smart washer" with the impedance method is proposed with the aim of developing a real-time device to monitor the pre-stress level of rock bolts. The proposed method was verified through tests on a rock bolt specimen. By applying high-frequency sweep excitations (typically >30 kHz) to the smart washer that was installed on the rock bolt specimen, we observed that the variation in impedance signatures indicated the rock bolt pre-stress status. With the degradation of rock bolt pre-stress, the frequency in the dominating peak of the real part of the electrical impedance signature increased. To quantify the effectiveness of the proposed technique, a normalized root mean square deviation (RMSD) index was developed to evaluate the degradation level of the rock bolt pre-stress. The experimental results demonstrated that the normalized RMSD-based looseness index, which was computed from the impedance value detected by the "smart washer", increased with loss of the pre-stress of the rock bolt. Therefore, the proposed method can effectively detect the degradation of rock bolt pre-stress, as demonstrated by experiments.

  17. Reconstruction of the rock fall/avalanche frequency in the Mont Blanc massif since the Last Glacial Maximum. New results using 10Be cosmogenic dating and reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Gallach, Xavi; Ogier, Christophe; Ravanel, Ludovic; Deline, Philip; Carcaillet, Julien

    2017-04-01

    Rockfalls and rock avalanches are active processes in the Mont Blanc massif, with infrastructure and alpinists at risk. Thanks to a network of observers (hut keepers, mountain guides, alpinists) set up in 2007 present rockfalls are well surveyed and documented. Rockfall frequency over the past 150 years has been studied by comparison of historical photographs, showing that it strongly increased during the three last decades, especially during hot periods like the summer of 2003 and 2015, due to permafrost degradation driven by the climate change. In order to decipher the possible relationship between rockfall occurrence and the warmest periods of the Lateglacial and the Holocene, we start to study the morphodynamics of some selected high-elevated (>3000 m a.s.l.) rockwalls of the massif on a long timescale. Contrary to low altitude, deglaciated sites where study of large rockfall deposits allows to quantify frequency and magnitude of the process, rockfalls that detached from high-elevated rockwalls are no more noticeable as debris were absorbed and evacuated by the glaciers. Therefore, our study focuses on the rockfall scars. Their 10Be dating gives us the rock surface exposure age from present to far beyond the Last Glacial Maximum, interpreted as the rockfall ages. TCN dating of rockfalls has been carried out at the Aiguille du Midi in 2007 (Boehlert et al., 2008), and three other sites in the Mont Blanc massif in 2011 (Gallach et al., submitted). Here we present a new data set of rockfall dating carried out in 2015 that improves the 2007 and 2011 data. Furthermore, a relationship between the colour of the Mont Blanc granite and its exposure age has been shown: fresh rock surface is light grey (e.g. in recent rockfall scars) whereas weathered rock surface is in the range grey to orange/red: the redder a rock surface, the older its age. Here, reflectance spectroscopy is used to quantify the granite surface colour. Böhlert, R., Gruber, S., Egli, M., Maisch, M

  18. Rock mass diagnostics based on microseismic monitoring data at Sheregesh deposit

    NASA Astrophysics Data System (ADS)

    Lobanova, TV; Lindin, GL; Trofimova, OL; Shultaev, SK; Prib, VV

    2017-02-01

    Distribution of seismic events in rocks mass around a mineral deposit is studied, it is found that the distribution features conform with the local blasting operations and geology. Epicenters of concentration zones of seismic events are detected in the area of stoping and faulting between two ore locuses. Weakening planes generated under four chronologically ordered shocks are indentified. Occurrence of these planes is characterized, and the stress redistribution after blasting is analyzed. The authors apply an integrated approach to rockburst hazard prediction, including calculus of apparent velocity of migration of seismic events during the first ten minutes after a blast and the rockburst probability assessment.

  19. Monitoring of the volcanic rock compositions during the 2012-2013 fissure eruption at Tolbachik volcano, Kamchatka

    NASA Astrophysics Data System (ADS)

    Volynets, Anna O.; Edwards, Benjamin R.; Melnikov, Dmitry; Yakushev, Anton; Griboedova, Irina

    2015-12-01

    Here we present the results from monitoring of the composition of rocks produced during the 2012-2013 fissure eruption at Tolbachik volcano (FTE). Major and trace element concentrations in 75 samples are reported. Products of this eruption are represented by high alumina basaltic trachyandesites with higher alkalis and titanium contents than in all previously studied rocks of the Tolbachik monogenetic volcanic field. Rocks erupted during the first three days (27-30 November) from the northern (also called Menyailov) group of vents are the most silica- and alkali-rich (SiO2 concentrations up to 55.35 wt.% and K2O up to 2.67 wt.%). From December onwards, when the eruptive activity switched from the Menyailov vents to the southern (Naboko) group of vents, silica content dropped by 2 wt.%, concentrations of MgO, FeO, TiO2 and Mg# increased, and K2O and Na2O concentrations and K2O/MgO ratio decreased. For the rest of the eruption the compositions of rocks remained constant and homogeneous; no systematic compositional differences between lava, bombs and scoria samples are evident. Trace element distributions in the rocks of the Menyailov and Naboko vent lavas are relatively uniform; Menyailov lavas have slightly higher Th, Nb, Hf, Y, and HREE concentrations than the Naboko vent lavas at more or less constant element ratios. We explain the initial change in geochemistry by tapping of a slightly cooler and fractionated (~ 3% Mt and 8% Cpx) upper part of the magma storage zone before the main storage area began to feed the eruption. Thermodynamic constraints show that apparent liquidus temperatures varied from 1142 °C to 1151 °C, and thermodynamic modeling shows that variations in compositions are consistent with a high degree of low pressure (100-300 MPa), nominally anhydrous fractionation of a parent melt compositionally similar to the 1975 Northern Breakthrough high-Mg basalt. Geochemistry, petrological observations and modeling are in agreement with the newly erupted

  20. Monitoring and Evaluation of Yearling Fall Chinook Salmon Released from Acclimation Facilities Upstream of Lower Granite Dam; 1998 Annual Report.

    SciTech Connect

    Rocklage, Stephen J.

    2004-01-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery (Snake River stock) yearling fall chinook salmon that were acclimated and released at three Fall Chinook Acclimation Project sites upstream of Lower Granite Dam along with yearlings released on-station from Lyons Ferry Hatchery in 1998. The three fall chinook acclimation facilities are operated by the Nez Perce Tribe and located at Pittsburg Landing and Captain John Rapids on the Snake River and at Big Canyon Creek on the Clearwater River. Yearlings at the Big Canyon facility consisted of two size classes that are referred to in this report as 9.5 fish per pound (fpp) and 30 fpp. The Big Canyon 9.5 fpp were comparable to the yearlings at Pittsburg Landing, Captain John Rapids and Lyons Ferry Hatchery. A total of 9,942 yearlings were PIT tagged and released at Pittsburg Landing. PIT tagged yearlings had a mean fork length of 159.9 mm and mean condition factor of 1.19. Of the 9,942 PIT tagged fish released, a total of 6,836 unique tags were detected at mainstem Snake and Columbia River dams (Lower Granite, Little Goose, Lower Monumental and McNary). A total of 4,926 9.5 fpp and 2,532 30 fpp yearlings were PIT tagged and released at Big Canyon. PIT tagged 9.5 fpp yearlings had a mean fork length of 156.9 mm and mean condition factor of 1.13. PIT tagged 30 fpp yearlings had a mean fork length of 113.1 mm and mean condition factor of 1.18. Of the 4,926 PIT tagged 9.5 fpp yearlings released, a total of 3,042 unique tags were detected at mainstem Snake and Columbia River dams. Of the 2,532 PIT tagged 30 fpp yearlings released, a total of 1,130 unique tags were detected at mainstem Snake and Columbia River dams. A total of 1,253 yearlings were PIT tagged and released at Captain John Rapids. PIT tagged yearlings had a mean fork length of 147.5 mm and mean condition factor of 1.09. Of

  1. Analysis of a Large Rock Slope Failure on the East Wall of the LAB Chrysotile Mine in Canada: LiDAR Monitoring and Displacement Analyses

    NASA Astrophysics Data System (ADS)

    Caudal, Philippe; Grenon, Martin; Turmel, Dominique; Locat, Jacques

    2017-04-01

    A major mining slope failure occurred in July 2012 on the East wall of the LAB Chrysotile mine in Canada. The major consequence of this failure was the loss of the local highway (Road 112), the main economic link between the region and the Northeast USA. This paper is part of a proposed integrated remote sensing-numerical modelling methodology to analyze mining rock slope stability. This paper presents the Light Detection and Ranging (LiDAR) monitoring of this slope failure. The main focus is the investigation of that rock slide using both terrestrial (TLS) and airborne (ALS) LiDAR scanning. Since 2010, four ALS and 14 TLS were performed to characterize and monitor the slide. First, laser scanning was used to investigate the geometry of the slide. The failure zone was 1100 m by 250 m in size with a mobilized volume of 25 hm3. Laser scanning was then used to investigate the rock slide's 3D displacement, thereby enabling a better understanding of the sliding kinematics. The results clearly demonstrate the ability of the proposed approach to monitor and quantify large-scale rock mass failure. The slope was monitored for a period of 5 years, and the total displacement was measured at every survey. The maximum cumulative total displacement reached was 145 m. This paper clearly shows the ability of LiDAR scanning to provide valuable quantitative information on large rock mass failures involving very large displacements.

  2. Characterization and monitoring of the Séchilienne rock slope using 3D imaging methods (Isère, France)

    NASA Astrophysics Data System (ADS)

    Vulliez, Cindy; Guerin, Antoine; Abellán, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel; Chanut, Marie-Aurélie; Dubois, Laurent; Duranthon, Jean-Paul

    2016-04-01

    The Séchilienne landslide located in the Romanche Valley (Isère, France) is a well instrumented mass movements of about 650 m high and 250 m wide, with a potential volume of about 3 million m3 in the most active part (Duranthon and Effendiantz, 2004 ; Kasperski et al., 2010). The slope, which is mainly composed of micaschist, is characterized by the presence of a NE-SW sub-vertical fracturing system involved in the destabilization of the area. The rock slope has been continuously moving since the eighties decade, with a growing acceleration during the period 2009-2013 followed by a progressive stabilization during the last years. The monitoring of the active part of the rock slide is currently carried out by an instrumentation system in order to prevent a large failure. In this work, we used different 3D techniques in order to monitor the whole rock slide displacements in three dimensions, as follows: (a) First of all, we used a Terrestrial Laser Scanning to obtain high resolution point clouds (8 cm point spacing) of the rock slope geometry. Nine different fieldwork campaigns were performed during the last six years, as follows: Aug. 2009, Jul. 2010, Nov. 2011, Nov. 2012, Jun. and Nov. 2013, Jul. and Oct. 2014, May 2015, which provided a set of 3D representations of the rock slope topography over time; (b) In addition, we used three Helicopter-based Laser Scanning campaigns carried out in Jan. 2011, Feb. 2012 and Mar. 2014 acquired by the Cerema (Chanut et al., 2014); (c) Finally, more than 600 photos were taken in Apr. 2015 in order to build a photogrammetric model of the area using Structure-from-Motion (SfM) workflow in Agisoft PhotoScan software. All types of data were complementary for the study of the movement and allowed us having a good spatial vision of the evolution of the most active part of the slope. A detailed structural analysis was performed from both LiDAR and SfM point clouds using Coltop3D (Jaboyedoff et al., 2007). Eight joint sets were

  3. Bioremediation in Fractured Rock: 1. Modeling to Inform Design, Monitoring, and Expectations.

    PubMed

    Tiedeman, Claire R; Shapiro, Allen M; Hsieh, Paul A; Imbrigiotta, Thomas E; Goode, Daniel J; Lacombe, Pierre J; DeFlaun, Mary F; Drew, Scott R; Johnson, Carole D; Williams, John H; Curtis, Gary P

    2017-09-05

    Field characterization of a trichloroethene (TCE) source area in fractured mudstones produced a detailed understanding of the geology, contaminant distribution in fractures and the rock matrix, and hydraulic and transport properties. Groundwater flow and chemical transport modeling that synthesized the field characterization information proved critical for designing bioremediation of the source area. The planned bioremediation involved injecting emulsified vegetable oil and bacteria to enhance the naturally occurring biodegradation of TCE. The flow and transport modeling showed that injection will spread amendments widely over a zone of lower-permeability fractures, with long residence times expected because of small velocities after injection and sorption of emulsified vegetable oil onto solids. Amendments transported out of this zone will be diluted by groundwater flux from other areas, limiting bioremediation effectiveness downgradient. At nearby pumping wells, further dilution is expected to make bioremediation effects undetectable in the pumped water. The results emphasize that in fracture-dominated flow regimes, the extent of injected amendments cannot be conceptualized using simple homogeneous models of groundwater flow commonly adopted to design injections in unconsolidated porous media (e.g., radial diverging or dipole flow regimes). Instead, it is important to synthesize site characterization information using a groundwater flow model that includes discrete features representing high- and low-permeability fractures. This type of model accounts for the highly heterogeneous hydraulic conductivity and groundwater fluxes in fractured-rock aquifers, and facilitates designing injection strategies that target specific volumes of the aquifer and maximize the distribution of amendments over these volumes. © 2017, National Ground Water Association.

  4. Compliance Monitoring of Underwater Blasting for Rock Removal at Warrior Point, Columbia River Channel Improvement Project, 2009/2010

    SciTech Connect

    Carlson, Thomas J.; Johnson, Gary E.; Woodley, Christa M.; Skalski, J. R.; Seaburg, Adam

    2011-05-10

    The U.S. Army Corps of Engineers, Portland District (USACE) conducted the 20-year Columbia River Channel Improvement Project (CRCIP) to deepen the navigation channel between Portland, Oregon, and the Pacific Ocean to allow transit of fully loaded Panamax ships (100 ft wide, 600 to 700 ft long, and draft 45 to 50 ft). In the vicinity of Warrior Point, between river miles (RM) 87 and 88 near St. Helens, Oregon, the USACE conducted underwater blasting and dredging to remove 300,000 yd3 of a basalt rock formation to reach a depth of 44 ft in the Columbia River navigation channel. The purpose of this report is to document methods and results of the compliance monitoring study for the blasting project at Warrior Point in the Columbia River.

  5. Rock Erodibility as a Dynamic Variable Driven by the Interplay between Erosion and Weathering in Bedrock Channels: Examples from Great Falls, Virginia, USA

    NASA Astrophysics Data System (ADS)

    Hancock, G. S.; Huettenmoser, J.; Shobe, C. M.; Eppes, M. C.

    2016-12-01

    Rock erodibility in channels is a primary control on the stresses required to erode bedrock (e.g., Sklar and Dietrich, 2001). Erodibility tends to be treated as a uniform and fixed variable at the scale of channel cross-sections, particularly in models of channel profile evolution. Here we present field data supporting the hypothesis (Hancock et al., 2011) that erodibility is a dynamic variable, driven by the interplay between erosion rate and weathering processes within cross-sections. We hypothesize that rock weathering varies in cross-sections from virtually unweathered in the thalweg, where frequent stripping removes weathered rock, to a degree of weathering determined by the frequency of erosive events higher on the channel margin. We test this hypothesis on three tributaries to the Potomac River underlain by similar bedrock but with varying erosion rates ( 0.01 to 0.8 m/ky). At multiple heights within three cross-sections on three tributaries, we measured compressive strength with a Schmidt hammer, surface roughness with a contour gage, and density and length of visible cracks. Compressive strength decreased with height in all nine cross-sections by 10% to 50%, and surface roughness increased with height in seven cross-sections by 25% - 45%, with the remaining two showing minimal change. Crack density increased with height in the three cross-sections measured. Taken together these data demonstrate increases in weathering intensity, and presumably, rock erodibility, with height. The y-intercept of the relation between height and the three measured variables were nearly identical, suggesting that thalweg erodibility was similar on each channel, as predicted, even though erodibility higher in the cross-section were markedly different. The rate at which the three variables changed with height in each cross-section is strongly related to stream power. Assuming stream power is a reasonable surrogate for erosion rate, this result implies that erosion rate can be a

  6. Fluid and Rock Property Controls On Production And Seismic Monitoring Alaska Heavy Oils

    SciTech Connect

    Liberatore, Matthew; Herring, Andy; Prasad, Manika; Dorgan, John; Batzle, Mike

    2012-10-30

    The goal of this project is to improve recovery of Alaskan North Slope (ANS) heavy oil resources in the Ugnu formation by improving our understanding of the formation's vertical and lateral heterogeneities via core evaluation, evaluating possible recovery processes, and employing geophysical monitoring to assess production and modify production operations.

  7. Towards falls prevention: a wearable wireless and battery-less sensing and automatic identification tag for real time monitoring of human movements.

    PubMed

    Ranasinghe, Damith C; Shinmoto Torres, Roberto L; Sample, Alanson P; Smith, Joshua R; Hill, Keith; Visvanathan, Renuka

    2012-01-01

    Falls related injuries among elderly patients in hospitals or residents in residential care facilities is a significant problem that causes emotional and physical trauma to those involved while presenting a rising healthcare expense in countries such as Australia where the population is ageing. Novel approaches using low cost and privacy preserving sensor enabled Radio Frequency Identification (RFID) technology may have the potential to provide a low cost and effective technological intervention to prevent falls in hospitals. We outline the details of a wearable sensor enabled RFID tag that is battery free, low cost, lightweight, maintenance free and can be worn continuously for automatic and unsupervised remote monitoring of activities of frail patients at acute hospitals or residents in residential care. The technological developments outlined in the paper forms part of an overall technological intervention developed to reduce falls at acute hospitals or in residential care facilities. This paper outlines the details of the technology, underlying algorithms and the results (where an accuracy of 94-100% was achieved) of a successful pilot trial.

  8. 189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

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

    189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ROCK CREEK CROSSING, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  9. Formal and informal trail monitoring protocols and baseline conditions: Great Falls Park and Potomac Gorge. Final research report

    USGS Publications Warehouse

    Wimpey, Jeremy; Marion, Jeffrey L.

    2011-01-01

    This report presents the results of research on the conditions of formal and informal (visitorcreated) trails conducted within the Great Falls Park (GFP) portion of George Washington Memorial Parkway (GWMP), Virginia, and the adjacent Maryland portions of the C&O Canal National Historical Park (CHOH). This research was prompted primarily by concerns about the impact of extensive informal trail networks within both parks on native vegetation and rare plant communities, rare flora and fauna, and historic and archaeological resources. Resource conditions on formal park trails were also assessed to provide information supporting the development of park planning and management decision-making.

  10. One year terrestrial laser scanning monitoring of an active rockslide in highly deformed rocks in western Swiss Alps

    NASA Astrophysics Data System (ADS)

    Carrea, D.; Derron, M.-H.; Gauvin, N.; Jaboyedoff, M.

    2012-04-01

    The area of Montatuay (Val Ferret, Valais) is known for numerous instabilities affecting its mountain sides. The February 10th 2011 a sudden rockslide of ~200 m high and ~1'000 m3 happened on western flank of Montatuay which results in obstructing the river. The rockslide morphology is divided in two zones. An active zone in the upper part producing blocks and fine grained material and a deposit talus in the lower part. The geological context shows highly deformed rocks of different lithologies as limestone, black shale, dolomite, gypsum from Ultrahelvetic sedimentary cover. During 2011, studies were carried out in the field, as well as terrestrial laser scanner and high resolution DEM analysis. After one year of TLS monitoring, newly developed algorithm enabled to measure displacements and deformation rate. The algorithm is based on a multi-steps automatic shape tracking process in MATLAB providing roto-translation matrix of discrete parts of the topography. Fallen volumes and potentially unstable volumes were estimated from DEM and TLS data combined with Sloping Local Base Level (Jaboyedoff et al. 2004). First results obtained by algorithm have shown a deceleration of movement in the upper part and reduction of deposition in the talus deposit. The monitoring with TLS of the talus deposit also points out that it is still unstable due to river erosion. In a global setting, this active rockslide is part of a larger sagging area and potentially influenced by a deep-seated gravitational slope deformation affecting Montatuay.

  11. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  12. Falling chains

    NASA Astrophysics Data System (ADS)

    Wong, Chun Wa; Yasui, Kosuke

    2006-06-01

    The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is incorrect because it neglects the energy gained when a link leaves a subchain. The maximum chain tension measured by Calkin and March for the falling folded chain is given a simple if rough interpretation. Other aspects of the falling folded chain are briefly discussed.

  13. Experimental results on rock resistivity and its applications in monitoring and predicting natural disasters

    NASA Astrophysics Data System (ADS)

    Zhou, Jianguo; Zhu, Tao; Tang, Baolin

    2017-04-01

    There have been many earthquakes occurring in Chinese Mainland. These earthquakes, especially large earthquakes, often cause immeasurable loss. For instance, the 2008 Wenchuan Ms8.0 earthquake killed 70, 000 people and caused 17, 000 people missing. It is well known that this earthquake was not predicted. Why? Were there no precursors? After analyzing the geo-electrical resistivity recording at Chengdu station which is only about 36 km to the epicenter, we find that resistivity had changed abnormally very significantly along NE direction but no outstanding abnormal changes had been observed along NW direction before the earthquake. Perhaps this non-consistent changes result in that this earthquake was not predicted. However, in another standpoint, can another observation way be found to supplement the current geo-electrical resistivity observation in Chinese Mainland in order to improve the probability of catching the precursor? This motivates us to conduct experiments in lab and field. Apparent resistivity data are acquired along three common-midpoint measuring lines during the fixed-rate uniaxial compression on two sets of dry man-made samples and a Magnetite sample. We construct the relative resistivity change images (RRCIs). Our results indicate that all RRCIs show a trending change with stress: with the increase of stress, the resistivity-decreased region (RDR) in the RRCIs shrinks/expands, while the resistivity-increased region (RIR) expands/shrinks gradually, which is in agreement with the field experimental results of earthquake monitoring (Feng et al., 2001). Our results encourage us to conclude that the trending changes in RRCI with stress could probably become a useful indicator in monitoring and predicting earthquakes, volcanic eruptions and large-scale geologic movements. This work is supported by National Natural Science Foundation of China (NSFC, Grant 41574083).

  14. Development of a Tool Condition Monitoring System for Impregnated Diamond Bits in Rock Drilling Applications

    NASA Astrophysics Data System (ADS)

    Perez, Santiago; Karakus, Murat; Pellet, Frederic

    2017-05-01

    The great success and widespread use of impregnated diamond (ID) bits are due to their self-sharpening mechanism, which consists of a constant renewal of diamonds acting at the cutting face as the bit wears out. It is therefore important to keep this mechanism acting throughout the lifespan of the bit. Nonetheless, such a mechanism can be altered by the blunting of the bit that ultimately leads to a less than optimal drilling performance. For this reason, this paper aims at investigating the applicability of artificial intelligence-based techniques in order to monitor tool condition of ID bits, i.e. sharp or blunt, under laboratory conditions. Accordingly, topologically invariant tests are carried out with sharp and blunt bits conditions while recording acoustic emissions (AE) and measuring-while-drilling variables. The combined output of acoustic emission root-mean-square value (AErms), depth of cut ( d), torque (tob) and weight-on-bit (wob) is then utilized to create two approaches in order to predict the wear state condition of the bits. One approach is based on the combination of the aforementioned variables and another on the specific energy of drilling. The two different approaches are assessed for classification performance with various pattern recognition algorithms, such as simple trees, support vector machines, k-nearest neighbour, boosted trees and artificial neural networks. In general, Acceptable pattern recognition rates were obtained, although the subset composed by AErms and tob excels due to the high classification performances rates and fewer input variables.

  15. Monitoring and Evaluation of Yearling Fall Chinook Salmon (Oncorhynchus tshawytscha) Released from Acclimation Facilities Upstream of Lower Granite Dam; 2002 Annual Report.

    SciTech Connect

    Rocklage, Stephen J.; Kellar, Dale S.

    2005-07-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery reared yearling fall Chinook salmon Oncorhynchus tshawytscha that were acclimated and released at three Fall Chinook Acclimation Project sites upstream of Lower Granite Dam in 2002. This was the seventh year of a long-term project to supplement natural spawning populations of Snake River stock fall Chinook salmon upstream of Lower Granite Dam. The 479,358 yearlings released from the Fall Chinook Acclimation Project facilities exceeded the 450,000 fish quota. We use Passive Integrated Transponder (PIT) tag technology to monitor the primary performance measures of survival to mainstem dams and migration timing. We also monitor size, condition and tag/mark retention at release. We released 7,545 PIT tagged yearlings from Pittsburg Landing, 7,482 from Big Canyon and 2,487 from Captain John Rapids. Fish health sampling indicated that, overall, bacterial kidney disease levels at the acclimation facilities could be considered medium to high with 43-62% of fish sampled rating medium to very high. Mean fork lengths (95% confidence interval) of the PIT tagged groups ranged from 146.7 mm (146.2-147.2 mm) at Captain John Rapids to 164.8 mm (163.5-166.1 mm) at Lyons Ferry Hatchery. Mean condition factors ranged from 1.06 at Lyons Ferry Hatchery to 1.14 at Pittsburg Landing and Captain John Rapids. Estimated survival (95% confidence interval) of PIT tagged yearlings from release to Lower Granite Dam ranged from 88.6% (86.0-91.1%) for Pittsburg Landing to 97.0% (92.4-101.7%) for Captain John Rapids. Estimated survival from release to McNary Dam ranged from 54.3% (50.2-58.3%) for Big Canyon to 70.5% (65.4-75.5%) for Pittsburg Landing. Median migration rates to Lower Granite Dam, based on all observations of PIT tagged yearlings from the FCAP facilities, ranged from 8.1 river kilometers per

  16. Episodes of Fall Asleep During Day Time in an Elder Woman with Vascular Dementia: Impact on Cerebral Ischeamic Tolerance and Utility of ECG Holter Monitoring

    PubMed Central

    Ciulla, Michele M; Acquistapace, Giulia; Paliotti, Roberta; Benfenati, Chiara; Magrini, Fabio

    2010-01-01

    Here we report the case of an 86-year-old woman with advanced dementia addressed to our service for routinary ECG Holter Monitoring (EHM) for bradycardia in AV block type I. Several day-time episodes of fall-asleep while sitting had been previously reported by the nurse and generally attributed to the dementia itself, without taking into consideration the hypothesis of an AV block. The EHM reading reported several and often subsequent pauses (561), many of them critical, the longest lasting 15,9 s with no changes in clinical condition of the patient. The results of the EHM were reported to the physicians in charge for the patient and subsequently the woman was referred to the arrhythmology unit for pace-maker device implantation. Generalizing our experience, we suggest that advanced dementia, often associated with episodes of fall-asleep, could mask a conduction disturbance causing critical pauses with syncope; therefore we suggest screening those patients for possible arrhythmic disorders. Finally, we remark that in our patient the pauses weren’t associated with a worsening of the patient as seen in the follow-up, and this fact supports the hypothesis that vascular dementia could increase cerebral ischaemic tolerance. PMID:21160915

  17. Satellite based remote sensing technique as a tool for real time monitoring of leaf retention in natural rubber plantations affected by abnormal leaf fall disease

    NASA Astrophysics Data System (ADS)

    Pradeep, B.; Meti, S.; James, J.

    2014-11-01

    Most parts of the traditional natural rubber growing regions of India, extending from Kanyakumari district of Tamil Nadu in the South to Kasaragod district of Kerala in the North received excess and prolonged rains during 2013. This led to severe incidence of Abnormal Leaf Fall (ALF) disease caused by the fungus, Phytophthora sp. The present study demonstrated the first time use of satellite remote sensing technique to monitor ALF disease by estimating Leaf Area Index (LAI) in natural rubber holdings in near real time. Leaf retention was monitored in between April and December 2012 and 2013 by estimating LAI using MODIS 15A2 product covering rubber holdings spread across all districts in the traditional rubber growing region of the country that was mapped using Resourcesat LISS III 2012 and 2013 data. It was found that as the monsoon advanced, LAI decreased substantially in both years, but the reduction was much more substantial and prolonged in many districts during 2013 than 2012 reflecting increased leaf fall due to ALF disease in 2013. The decline was more pronounced in central and northern Kerala than in the South. Kanyakumari district of Tamil Nadu is generally known to be free from ALF disease, but there was considerable leaf loss due to ALF in June 2012 and June and July 2013 even as the monsoon was unusually severe in 2013. Weighted mean LAI during for the entire period of April to December was estimated as a weighted average of LAI and per cent of total area under rubber in each district in the study area for the two years. This was markedly less in 2013 than 2012. The implications of poor leaf retention for biomass production (net primary productivity), carbon sequestration and rubber yield are discussed.

  18. Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions

    NASA Astrophysics Data System (ADS)

    Guglielmin, Mauro; Worland, M. Roger; Baio, Fabio; Convey, Peter

    2014-11-01

    In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between - 3.7 and - 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze-thaw events were negligible (0-3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual

  19. Five-year performance monitoring of a high-density polyethylene (HDPE) cover system at a reclaimed mine waste rock pile in the Sydney Coalfield (Nova Scotia, Canada).

    PubMed

    Power, Christopher; Ramasamy, Murugan; MacAskill, Devin; Shea, Joseph; MacPhee, Joseph; Mayich, David; Baechler, Fred; Mkandawire, Martin

    2017-09-29

    Cover systems are commonly placed over waste rock piles (WRPs) to limit atmospheric water and oxygen ingress and control the generation and release of acid mine drainage (AMD) to the receiving environment. Although covers containing geomembranes such as high-density polyethylene (HDPE) exhibit the attributes to be highly effective, there are few, if any, published studies monitoring their performance at full-scale WRPs. In 2011, a HDPE cover was installed over the Scotchtown Summit WRP in Nova Scotia, Canada, and extensive field performance monitoring was conducted over the next five years. A range of parameters within the atmosphere, cover, waste rock, groundwater and surface water, were monitored and integrated into a comprehensive hydrogeochemical conceptual model to assess (i) atmospheric ingress to the waste rock, (ii) waste rock acidity and depletion and (iii) evolution of groundwater and surface water quality. Results demonstrate that the cover is effective and meeting site closure objectives. Depletion in oxygen influx resulted in slower sulphide oxidation and AMD generation, while a significant reduction in water influx (i.e. 512 to 50 mm/year) resulted in diminished AMD release. Consistent improvements in groundwater quality (decrease in sulphate and metals; increase in pH) beneath and downgradient of the WRP were observed. Protection and/or significant improvement in surface water quality was evident in all surrounding watercourses due to the improved groundwater plume and elimination of contaminated runoff over previously exposed waste rock. A variably saturated flow and contaminant transport model is currently being developed to predict long-term cover system performance.

  20. Evaluation of the applicability of optical fiber strain sensors for monitoring rock deformation caused by ocean tide -a case study at the Aburatsubo site, Japan-

    NASA Astrophysics Data System (ADS)

    Matsui, H.; Kashiwai, Y.; Sano, O.; Tokunaga, T.; He, Z.; Mogi, K.; Wang, H. F.

    2009-12-01

    Monitoring rock deformation with high resolution is one of the essential factors for crustal deformation studies. Extensometers with several tens of meters long and inclinometer with similar length have been used as conventional monitoring methods. Because these large scale sensors require vast space for monitoring, it is difficult to distribute many monitoring points with high density. It is also difficult to conduct spatially high resolution monitoring. These limits on present monitoring methods make it difficult to evaluate the effects of heterogeneity of the rock masses and of the existence of fractures on the measured behavior of rock masses. In other words, scale dependency of rock deformation has not yet been studied through in-situ data. Thus, the small sensors with high resolution are required. We are planning to develop an ultra-high resolution sensor based on the optical fiber sensing technology in the three-year period. The optical fiber sensor has advantages against conventional electric sensors; long term stability, flexibility of incorporating many types of sensors on a single data acquisition cable, and a future promise for the methods to become even better, cheaper, and faster. The Fiber Bragg Grating (FBG) sensing technology is chosen as a potential method out of many kinds of optical fiber sensing methods, and a pair of commercially available FBG sensors were deployed in the Aburatsubo Earthquake Observation Center, the Earthquake Research Institute, University of Tokyo, for verifying their resolution and stability. According to the strain measurements by conventional extensometers at the Aburatsubo site, deformation on the order of 10-7 strain caused by ocean tides is observed. Purpose of the first stage of this developing work is to evaluate the commercially available FBG sensor and to study the feasibility for developing the precise small sensor for rock mechanics study. The FBG sensor successfully monitored the deformations caused by ocean

  1. Fall Frosting

    NASA Image and Video Library

    2013-10-16

    Richardson Crater is home to this sea of sand dunes. It was fall in the Southern hemisphere when NASA MRO acquired this image of the dunes frosted with the first bit of carbon dioxide ice condensed from the atmosphere.

  2. Monitoring and Evaluation of Yearling Fall Chinook Salmon (Oncorhynchus tshawytscha) Released from Acclimation Facilities Upstream of Lower Granite Dam; 1999 Annual Report.

    SciTech Connect

    Rocklage, Stephen J.; Kellar, Dale S.

    2005-07-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery reared yearling fall Chinook salmon Oncorhynchus tshawytscha that were acclimated and released at three Fall Chinook Acclimation Project (FCAP) sites upstream of Lower Granite Dam along with yearlings released on-station from Lyons Ferry Hatchery in 1999. This was the fourth year of a long-term project to supplement natural spawning populations of Snake River stock fall Chinook salmon upstream of Lower Granite Dam. The 453,117 yearlings released from the Fall Chinook Acclimation Project facilities not only slightly exceeded the 450,000 fish quota, but a second release of 76,386 yearlings (hereafter called Surplus) were acclimated at the Big Canyon facility and released about two weeks after the primary releases. We use Passive Integrated Transponder (PIT) tag technology to monitor the primary performance measures of survival to mainstem dams and migration timing. We also monitor size, condition and tag/mark retention at release. We released 9,941 PIT tagged yearlings from Pittsburg Landing, 9,583 from Big Canyon, 2,511 Big Canyon Surplus and 2,494 from Captain John Rapids. The Washington Department of Fish and Wildlife released 983 PIT tagged yearlings from Lyons Ferry Hatchery. Fish health sampling indicated that, overall, bacterial kidney disease levels could be considered relatively low and did not appear to increase after transport to the acclimation facilities. Compared to prior years, Quantitative Health Assessment Indices were relatively low at Pittsburg Landing and Lyons Ferry Hatchery and relatively high at Big Canyon and Captain John Rapids. Mean fork lengths (95% confidence interval) of the release groups ranged from 147.4 mm (146.7-148.1 mm) at Captain John Rapids to 163.7 mm (163.3-164.1 mm) at Pittsburg Landing. Mean condition factors ranged from 1.04 at

  3. Monitoring and Evaluation of Yearling Fall Chinook Salmon (Oncorhynchus tshawytscha) Released from Acclimation Facilities Upstream of Lower Granite Dam; 2000 Annual Report.

    SciTech Connect

    Rocklage, Stephen J.; Kellar, Dale S.

    2005-07-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery reared yearling fall Chinook salmon Oncorhynchus tshawytscha that were acclimated and released at three Fall Chinook Acclimation Project sites upstream of Lower Granite Dam along with yearlings released on-station from Lyons Ferry Hatchery in 2000. This was the fifth year of a long-term project to supplement natural spawning populations of Snake River stock fall Chinook salmon upstream of Lower Granite Dam. The 397,339 yearlings released from the Fall Chinook Acclimation Project facilities were short of the 450,000 fish quota. We use Passive Integrated Transponder (PIT) tag technology to monitor the primary performance measures of survival to mainstem dams and migration timing. We also monitor size, condition and tag/mark retention at release. We released 7,477 PIT tagged yearlings from Pittsburg Landing, 7,421 from Big Canyon and 2,488 from Captain John Rapids. The Washington Department of Fish and Wildlife released 980 PIT tagged yearlings from Lyons Ferry Hatchery. Fish health sampling indicated that, overall, bacterial kidney disease levels could be considered relatively low. Compared to prior years, Quantitative Health Assessment Indices were relatively low at Big Canyon and Captain John Rapids and about average at Pittsburg Landing and Lyons Ferry Hatchery. Mean fork lengths (95% confidence interval) of the PIT tagged groups ranged from 157.7 mm (157.3-158.1 mm) at Big Canyon to 172.9 mm (172.2-173.6 mm) at Captain John Rapids. Mean condition factors ranged from 1.06 at Captain John Rapids and Lyons Ferry Hatchery to 1.12 at Big Canyon. Estimated survival (95% confidence interval) of PIT tagged yearlings from release to Lower Granite Dam ranged from 87.0% (84.7-89.4%) for Pittsburg Landing to 95.2% (91.5-98.9%) for Captain John Rapids. Estimated survival from release to

  4. Monitoring and Evaluation of Yearling Fall Chinook Salmon (Oncorhynchus tshawytscha) Released from Acclimation Facilities Upstream of Lower Granite Dam; 2004 Annual Report.

    SciTech Connect

    Rocklage, Stephen J. Nez Perce Tribe, Department of Fisheries Resource Management, Lapawi, ID)

    2005-07-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery reared yearling fall Chinook salmon Oncorhynchus tshawytscha that were acclimated and released at three Fall Chinook Acclimation Project (FCAP) sites upstream of Lower Granite Dam in 2004. This was the ninth year of a long-term project to supplement natural spawning populations of Snake River stock fall Chinook salmon upstream of Lower Granite Dam. The 414,452 yearlings released from the Fall Chinook Acclimation Project facilities were short of the 450,000 fish quota. We use Passive Integrated Transponder (PIT) tag technology to monitor the primary performance measures of survival to mainstem dams and migration timing. We also monitor size, condition and tag/mark retention at release. We released 4,983 PIT tagged yearlings from Pittsburg Landing, 4,984 from Big Canyon and 4,982 from Captain John Rapids. Fish health sampling indicated that, overall, bacterial kidney disease levels could be considered low with 53-94% rating not detected to low. Mean fork lengths (95% confidence interval) of the PIT tagged groups ranged from 154.6 mm (154.0-155.2 mm) at Pittsburg Landing to 163.0 mm (162.6-163.4 mm) at Captain John Rapids. Mean condition factors ranged from 1.06 at Lyons Ferry Hatchery to 1.16 at Big Canyon. Estimated survival (95% confidence interval) of PIT tagged yearlings from release to Lower Granite Dam ranged from 74.7% (72.9-76.5%) for Big Canyon to 88.1% (85.7-90.6%) for Captain John Rapids. Estimated survival from release to McNary Dam ranged from 45.3% (39.2-51.5%) for Pittsburg Landing to 52.1% (42.9-61.2%) for Big Canyon. Median migration rates to Lower Granite Dam, based on all observations of PIT tagged yearlings from the FCAP facilities, ranged from 5.5 river kilometers per day (rkm/d) for Captain John Rapids to 12.8 rkm/d for Pittsburg Landing. Median migration

  5. Monitoring and Evaluation of Yearling Fall Chinook Salmon (Oncorhynchus tshawytscha) Released from Acclimation Facilities Upstream of Lower Granite Dam; 2001 Annual Report.

    SciTech Connect

    Rocklage, Stephen J.; Kellar, Dale S.

    2005-07-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery reared yearling fall Chinook salmon Oncorhynchus tshawytscha that were acclimated and released at three Fall Chinook Acclimation Project sites upstream of Lower Granite Dam along with yearlings released on-station from Lyons Ferry Hatchery in 2001. This was the sixth year of a long-term project to supplement natural spawning populations of Snake River stock fall Chinook salmon upstream of Lower Granite Dam. The 318,932 yearlings released from the Fall Chinook Acclimation Project facilities were short of the 450,000 fish quota. We use Passive Integrated Transponder (PIT) tag technology to monitor the primary performance measures of survival to mainstem dams and migration timing. We also monitor size, condition and tag/mark retention at release. We released 7,503 PIT tagged yearlings from Pittsburg Landing, 7,499 from Big Canyon and 2,518 from Captain John Rapids. The Washington Department of Fish and Wildlife released 991 PIT tagged yearlings from Lyons Ferry Hatchery. Fish health sampling indicated that, overall, bacterial kidney disease levels could be considered relatively low. Compared to prior years, Quantitative Health Assessment Indices were relatively low at Big Canyon and Captain John Rapids and about average at Pittsburg Landing and Lyons Ferry Hatchery. Mean fork lengths (95% confidence interval) of the PIT tagged groups ranged from 155.4 mm (154.7-156.1 mm) at Captain John Rapids to 171.6 mm (170.7-172.5 mm) at Lyons Ferry Hatchery. Mean condition factors ranged from 1.02 at Lyons Ferry Hatchery to 1.16 at Big Canyon and Captain John Rapids. Estimated survival (95% confidence interval) of PIT tagged yearlings from release to Lower Granite Dam ranged from 74.4% (73.2-75.5%) for Big Canyon to 85.2% (83.5-87.0%) for Captain John Rapids. Estimated survival from release

  6. Monitoring and Evaluation of Yearling Fall Chinook Salmon (Oncorhynchus tshawytscha) Released from Acclimation Facilities Upstream of Lower Granite Dam; 2003 Annual Report.

    SciTech Connect

    Rocklage, Stephen J.

    2005-07-01

    The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery reared yearling fall Chinook salmon Oncorhynchus tshawytscha that were acclimated and released at three Fall Chinook Acclimation Project (FCAP) sites upstream of Lower Granite Dam in 2003. This was the eighth year of a long-term project to supplement natural spawning populations of Snake River stock fall Chinook salmon upstream of Lower Granite Dam. The 437,633 yearlings released from the Fall Chinook Acclimation Project facilities were short of the 450,000 fish quota. We use Passive Integrated Transponder (PIT) tag technology to monitor the primary performance measures of survival to mainstem dams and migration timing. We also monitor size, condition and tag/mark retention at release. We released 7,492 PIT tagged yearlings from Pittsburg Landing, 7,494 from Big Canyon and 2,497 from Captain John Rapids. Fish health sampling indicated that, overall, bacterial kidney disease levels at the acclimation facilities could be considered medium with 37-83% of the fish sampled rating medium to very high. Mean fork lengths (95% confidence interval) of the PIT tagged groups ranged from 153.7 mm (153.2-154.2 mm) at Captain John Rapids to 164.2 mm (163.9-164.5 mm) at Pittsburg Landing. Mean condition factors ranged from 1.06 at Lyons Ferry Hatchery to 1.22 at Captain John Rapids. Estimated survival (95% confidence interval) of PIT tagged yearlings from release to Lower Granite Dam ranged from 83.1% (80.7-85.5%) for Big Canyon to 91.7% (87.7-95.7%) for Captain John Rapids. Estimated survival from release to McNary Dam ranged from 59.9% (54.6-65.2%) for Big Canyon to 69.4% (60.5-78.4%) for Captain John Rapids. Median migration rates to Lower Granite Dam, based on all observations of PIT tagged yearlings from the FCAP facilities, ranged from 5.8 river kilometers per day (rkm/d) for Captain

  7. Monitoring the fall of large atmospheric ice conglomerations: a multianalytical approach to the study of the Mejorada del Campo megacryometeor.

    PubMed

    Orellana, Francisco Alamilla; Alegre, José Ma Ramiro; Cordero Pérez, José Carlos; Martín Redondo, Ma Paz; Delgado Huertas, Antonio; Fernández Sampedro, Ma Teresa; Menor-Salván, César; Ruiz-Bermejo, Marta; López-Vera, Fernando; Rodríguez-Losada, José A; Martinez-Frias, Jesus

    2008-04-01

    Certain local atmospheric anomalies, such as the formation of unusually large ice conglomerations (megacryometeors), have been proposed to be a potential natural hazard for people and aviation, as well as geoindicators for fingerprinting larger-scale atmospheric environmental changes. On March 13th 2007, at approximately 10:15 am, an ice chunk weighing about 10 kg fell from the clear-sky and crashed through the roof (around 15 m) of an industrial storage house in Mejorada del Campo, a town located 20 km east from Madrid. The megacryometeor monitoring follow-up and the original investigation presented here includes, for the first time, both logistic and scientific collaboration between the Laboratory of the Environment, Criminalistic Service (SECRIM, the Spanish "Guardia Civil") and academic and scientific institutions (universities and the Spanish National Research Council). We propose that the management procedure of the incident, along with the detailed scientific research and combination of analytical methodologies in different laboratories, can serve as a protocol model for other similar events.

  8. [Accidental falls].

    PubMed

    Inokuchi, Koichi

    2013-06-01

    Falls are common cause of injuries among elderly people, and fractures are the most serious consequence of falls. For seniors, hip fractures are the second major cause of bedridden. The feature and acute care of head injury, spinal cord injury, vertebrae fracture, and hip fracture are described. Just had fracture fixation, the patient can not go back to the original ADL. In order not to become bedridden, both medication and physical examination are important based on the new disease concept of locomotive syndrome. To do so, requires hospital and clinic cooperation. Sufficient cooperation is not currently possible, and spread of liaison service is essential.

  9. Drip shield Structural Response to Rock Fall

    SciTech Connect

    Z. Ceylan

    2004-04-01

    The objective of this calculation is to determine areas over the drip shield (DS) top plate and side-walls where the residual stress values exceed 50% of Ti-7 yield strength. These areas will also be referred to as the damaged areas throughout this document. The scope of this document is limited to reporting the calculation results in terms of the damaged areas based on a chosen set of stress components. This calculation is intended for use in support of the preliminary design activities for the license application design of the DS. This calculation is associated with the DS design and was performed by the Waste Package and Components. AP-3.12Q, ''Design Calculations and Analyses'' is used to perform the calculation and develop the document. The DS is classified as a safety category item. Therefore, this calculation is subject to the Quality Assurance Requirements and Description. The information provided by the sketches attached to this calculation is that of the potential design of the type of DS considered in this calculation and provides the potential dimensions and materials for the DS design. The finite element (FE) calculation was performed by using the commercially available LS-DYNA Version (V)960 (Software Tracking Number [STN] 10300-960.1106-00, Ref. 7) FE code. The results of this calculation were evaluated using residual first principal stress. Subsequent analysis of areas determined by residual stresses have been reported in the results section of this document. The finite element mesh adequacy was determined based on the maximum stress intensity and maximum first principal stress. The current work processes and procedures for the control of the electronic management of data for this activity were conducted in accordance with AP-3.13Q, ''Design Control'' (Section 5.1.2).

  10. Students fall for Fall Meeting

    NASA Astrophysics Data System (ADS)

    Smedley, Kara

    2012-02-01

    From Boston to Beijing, thousands of students traveled to San Francisco for the 2011 AGU Fall Meeting. Of those who participated, 183 students were able to attend thanks to AGU's student travel grant program, which assists students with travel costs and seeks to enrich the meeting through ethnic and gender diversity. Students at Fall Meeting enjoyed a variety of programs and activities designed to help them better network with their peers, learn about new fields, and disseminate their research to the interested public. More than 800 students attended AGU's first annual student mixer, sharing drinks and ideas with fellow student members and future colleagues as well as forging new friendships and intellectual relationships.

  11. Continuous measurements at the urban roadside in an Asian megacity by Aerosol Chemical Speciation Monitor (ACSM): particulate matter characteristics during fall and winter seasons in Hong Kong

    NASA Astrophysics Data System (ADS)

    Sun, C.; Lee, B. P.; Huang, D.; Jie Li, Y.; Schurman, M. I.; Louie, P. K. K.; Luk, C.; Chan, C. K.

    2016-02-01

    Non-refractory submicron aerosol is characterized using an Aerosol Chemical Speciation Monitor (ACSM) in the fall and winter seasons of 2013 on the roadside in an Asian megacity environment in Hong Kong. Organic aerosol (OA), characterized by application of Positive Matrix Factorization (PMF), and sulfate are found to be dominant. Traffic-related organic aerosol shows good correlation with other vehicle-related species, and cooking aerosol displays clear mealtime concentration maxima and association with surface winds from restaurant areas. Contributions of individual species and OA factors to high NR-PM1 are analyzed for hourly data and daily data; while cooking emissions in OA contribute to high hourly concentrations, particularly during mealtimes, secondary organic aerosol components are responsible for episodic events and high day-to-day PM concentrations. Clean periods are either associated with precipitation, which reduces secondary OA with a lesser impact on primary organics, or clean oceanic air masses with reduced long-range transport and better dilution of local pollution. Haze events are connected with increases in contribution of secondary organic aerosol, from 30 to 50 % among total non-refractory organics, and the influence of continental air masses.

  12. Continuous measurements at the urban roadside in an Asian Megacity by Aerosol Chemical Speciation Monitor (ACSM): particulate matter characteristics during fall and winter seasons in Hong Kong

    NASA Astrophysics Data System (ADS)

    Sun, C.; Lee, B. P.; Huang, D.; Li, Y. J.; Schurman, M. I.; Louie, P. K. K.; Luk, C.; Chan, C. K.

    2015-07-01

    Non-refractory submicron aerosol is characterized using an Aerosol Chemical Speciation Monitor (ACSM) in the fall and winter seasons of 2013 at the roadside in an Asian megacity environment in Hong Kong. Organic aerosol (OA), characterized by application of Positive Matrix Factorization (PMF), and sulfate are found dominant. Traffic-related organic aerosol shows good correlation with other vehicle-related species, and cooking aerosol displays clear meal-time concentration maxima and association with surface winds from restaurant areas. Contributions of individual species and OA factors to high NR-PM1 are analyzed for hourly data and daily data; while cooking emissions in OA contribute to high hourly concentrations, particularly during meal times, secondary organic aerosol components are responsible for episodic events and high day-to-day PM concentrations. Clean periods are either associated with precipitation, which reduces secondary OA with a~lesser impact on primary organics, or clean oceanic air masses with reduced long-range transport and better dilution of local pollution. Haze events are connected with increases in contribution of secondary organic aerosol, from 30 to 50 % among total non-refractory organics, and influence of continental air masses.

  13. The Geothermic Fatigue Hydraulic Fracturing Experiment in Äspö Hard Rock Laboratory, Sweden: New Insights Into Fracture Process through In-situ AE Monitoring

    NASA Astrophysics Data System (ADS)

    Kwiatek, G.; Plenkers, K.; Zang, A.; Stephansson, O.; Stenberg, L.

    2016-12-01

    The geothermic Fatigue Hydraulic Fracturing (FHF) in situ experiment (Nova project 54-14-1) took place in the Äspö Hard Rock Laboratory/Sweden in a 1.8 Ma old granitic to dioritic rock mass. The experiment aims at optimizing geothermal heat exchange in crystalline rock mass by multistage hydraulic fracturing at 10 m scale. Six fractures are driven by three different water injection schemes (continuous, cyclic, pulse pressurization) inside a 28 m long, horizontal borehole at depth level 410 m. The rock volume subject to hydraulic fracturing and monitored by three different networks with acoustic emission (AE), micro-seismicity and electromagnetic sensors is about 30 m x 30 m x 30 m in size. The 16-channel In-situ AE monitoring network by GMuG monitored the rupture generation and propagation in the frequency range 1000 Hz to 100,000 Hz corresponding to rupture dimensions from cm- to dm-scale. The in-situ AE monitoring system detected and analyzed AE activity in-situ (P- and S-wave picking, localization). The results were used to review the ongoing microfracturing activity in near real-time. The in-situ AE monitoring network successfully recorded and localized 196 seismic events for most, but not all, hydraulic fractures. All AE events detected in-situ occurred during fracturing time periods. The source parameters (fracture sizes, moment magnitudes, static stress drop) of AE events framing injection periods were calculated using the combined spectral fitting/spectra ratio techniques. The AE activity is clustered in space and clearly outline the fractures location, its orientation, and expansion as well as their temporal evolution. The outward migration of AE events away from the borehole is observed. Fractures extend up to 7 m from the injection interval in the horizontal borehole. The fractures orientation and location correlate for most fractures roughly with the results gained by image packer. Clear differences in seismic response between hydraulic fractures in

  14. White Rock

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  15. White Rock

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  16. Hydraulic fracture monitoring in hard rock at 410 m depth with an advanced fluid-injection protocol and extensive sensor array

    NASA Astrophysics Data System (ADS)

    Zang, A.; Stephansson, O.; Stenberg, L.; Plenkers, K.; Specht, S.; Milkereit, C.; Schill, E.; Kwiatek, G.; Dresen, G.; Zimmermann, G.; Dahm, T.; Weber, M.

    2016-11-01

    In this article, an underground experiment at the Äspö Hard Rock Laboratory (HRL) is described. Main goal is optimizing geothermal heat exchange in crystalline rock mass at depth by multi-stage hydraulic fracturing with minimal impact on the environment, i.e. seismic events. For this, three arrays with acoustic emission, microseismicity and electromagnetic sensors are installed mapping hydraulic fracture initiation and growth. Fractures are driven by three different water injection schemes (continuous, progressive, pulse pressurization). After a brief review of hydraulic fracture operations in crystalline rock mass at mine scale, the site geology and the stress conditions at Äspö HRL are described. Then, the continuous, single-flow rate and alternative, multiple-flow rate fracture breakdown tests in a horizontal borehole at depth level 410 m are described together with the monitoring networks and sensitivity. Monitoring results include the primary catalogue of acoustic emission hypocenters obtained from four hydraulic fractures with the in situ trigger and localizing network. The continuous versus alternative water injection schemes are discussed in terms of the fracture breakdown pressure, the fracture pattern from impression packer result and the monitoring at the arrays. An example of multi-stage hydraulic fracturing with several phases of opening and closing of fracture walls is evaluated using data from acoustic emissions, seismic broadband recordings and electromagnetic signal response. Based on our limited amount of in situ tests (six) and evaluation of three tests in Ävrö granodiorite, in the multiple-flow rate test with progressively increasing target pressure, the acoustic emission activity starts at a later stage in the fracturing process compared to the conventional fracturing case with continuous water injection. In tendency, also the total number and magnitude of acoustic events is found to be smaller in the progressive treatment with frequent

  17. Hydraulic fracture monitoring in hard rock at 410 m depth with an advanced fluid-injection protocol and extensive sensor array

    NASA Astrophysics Data System (ADS)

    Zang, Arno; Stephansson, Ove; Stenberg, Leif; Plenkers, Katrin; Specht, Sebastian; Milkereit, Claus; Schill, Eva; Kwiatek, Grzegorz; Dresen, Georg; Zimmermann, Günter; Dahm, Torsten; Weber, Michael

    2017-02-01

    In this paper, an underground experiment at the Äspö Hard Rock Laboratory (HRL) is described. Main goal is optimizing geothermal heat exchange in crystalline rock mass at depth by multistage hydraulic fracturing with minimal impact on the environment, that is, seismic events. For this, three arrays with acoustic emission, microseismicity and electromagnetic sensors are installed mapping hydraulic fracture initiation and growth. Fractures are driven by three different water injection schemes (continuous, progressive and pulse pressurization). After a brief review of hydraulic fracture operations in crystalline rock mass at mine scale, the site geology and the stress conditions at Äspö HRL are described. Then, the continuous, single-flow rate and alternative, multiple-flow rate fracture breakdown tests in a horizontal borehole at depth level 410 m are described together with the monitoring networks and sensitivity. Monitoring results include the primary catalogue of acoustic emission hypocentres obtained from four hydraulic fractures with the in situ trigger and localizing network. The continuous versus alternative water injection schemes are discussed in terms of the fracture breakdown pressure, the fracture pattern from impression packer result and the monitoring at the arrays. An example of multistage hydraulic fracturing with several phases of opening and closing of fracture walls is evaluated using data from acoustic emissions, seismic broad-band recordings and electromagnetic signal response. Based on our limited amount of in situ tests (six) and evaluation of three tests in Ävrö granodiorite, in the multiple-flow rate test with progressively increasing target pressure, the acoustic emission activity starts at a later stage in the fracturing process compared to the conventional fracturing case with continuous water injection. In tendency, also the total number and magnitude of acoustic events are found to be smaller in the progressive treatment with

  18. Shallow subsurface temperature and moisture monitoring at rock walls during freeze thaw cycles in the Northern Calcareous Alps, Austria

    NASA Astrophysics Data System (ADS)

    Rode, Matthias; Sass, Oliver

    2014-05-01

    The process of frost weathering as well as the contribution of further weathering processes (e.g. hydration, thermal fatigue) is poorly understood. For this purpose, different measuring systems were set up in two study areas (Dachstein massif - permafrost area (2700m asl, 47° 28' 32″ N, 13° 36' 23″ E) and Gesäuse mountains - non permafrost area (900m asl, 47° 35' 19″ N, 14° 39' 32″ E) located in Styria, Austria within the framework of the research project ROCKING ALPS (FWF-P2444). A key to understand frost weathering is to observe the rock temperature with several high resolution temperature sensors from the rock surface down to -20cm depth. The temperatures are measured hourly at north and south exposed rock walls since 2012 in the headwalls of the Dachstein glacier at the Koppenkarstein (built up of limestone) in about 2600m asl. Since 2013 the same measurement setup is installed in the lower Johnsbachtal (Gesäuse mountains, prevailing rock type is dolomite) in about 800m asl. To know the temperature is crucial to understand internal heat flow and transport and latent heat effects during freezing and thawing caused by night frost (lasting some hours), cold fronts (lasting some days) or winter frost of several weeks or months. At these study points we also have installed small-scale 2D-geoelectric survey lines, supplemented by moisture sensors. Moisture is determined by means of resistivity measurements which are difficult to calibrate, but provide good time series. Additional novel moisture sensors were developed which use the heat capacity of the surrounding rock as a proxy of water content. These sensors give point readings from a defined depth and are independent from soluble salt contents. First results from the Dachstein show that short term latent heat effects during the phase change have crucial influence on the moisture content. The moisture distribution and movements during temperature changes inside the rock are discussed upon the two main

  19. Accessory and rock forming minerals monitoring the evolution of zoned mafic ultramafic complexes in the Central Ural Mountains

    NASA Astrophysics Data System (ADS)

    Krause, J.; Brügmann, G. E.; Pushkarev, E. V.

    2007-04-01

    This study describes major and trace element compositions of accessory and rock forming minerals from three Uralian-Alaskan-type complexes in the Ural Mountains (Kytlym, Svetley Bor, Nizhnii Tagil) for the purpose of constraining the origin, evolution and composition of their parental melts. The mafic-ultramafic complexes in the Urals are aligned along a narrow, 900 km long belt. They consist of a central dunite body grading outward into clinopyroxenite and gabbro lithologies. Several of these dunite bodies have chromitites with platinum group element mineralization. High Fo contents in olivine (Fo 92-93) and high Cr/(Cr + Al) in spinel (0.67-0.84) suggest a MgO-rich (> 15 wt.%) and Al 2O 3-poor ultramafic parental magma. During its early stages the magma crystallized dominantly olivine, spinel and clinopyroxene forming cumulates of dunite, wehrlite and clinopyroxenite. This stage is monitored by a common decrease in the MgO content in olivine (Fo 93-86) and the Cr/(Cr + Al) value of coexisting accessory chromite (0.81-0.70). Subsequently, at subsolidus conditions, the chromite equilibrated with the surrounding silicates producing Fe-rich spinel while Al-rich spinel exsolved chromian picotite and chromian titanomagnetite. This generated the wide compositional ranges typical for spinel from Uralian-Alaskan-type complexes world wide. Laser ablation analyses (LA-ICPMS) reveal that clinopyroxene from dunites and clinopyroxenite from all three complexes have similar REE patterns with an enrichment of LREE (0.5-5.2 prim. mantle) and other highly incompatible elements (U, Th, Ba, Rb) relative to the HREE (0.25-2.0 prim. mantle). This large concentration range implies the extensive crystallization of olivine and clinopyroxene together with spinel from a continuously replenished, tapped and crystallizing magma chamber. Final crystallization of the melt in the pore spaces of the cooling cumulate pile explains the large variation in REE concentrations on the scale of a thin

  20. Imager displays free fall in stop action

    NASA Technical Reports Server (NTRS)

    Frazer, R. E.

    1981-01-01

    Microprocessor-controlled imaging system displays sequence of "frozen" images of free-falling object, using video cameras positioned along fall. Strobe lights flash as object passes each camera's viewfield. Sequence stored on video disk and displayed on television monitor is stop-action record of fall dynamics. With modification, system monitiors other high speed phenomena.

  1. Integration and assimilation of remote and terrestrial data for monitoring rock glaciers deformations: the innovative experiences from the SloMove project

    NASA Astrophysics Data System (ADS)

    Chinellato, Giulia; Cuozzo, Giovanni; Callegari, Mattia; Thiebes, Benni; Kenner, Robert; Petitta, Marcello

    2015-04-01

    We propose an innovative data integration methodology for monitoring landslides and slow moving processes such as rock glaciers. Within the Interreg project Slomove, we assimilated different sources of displacement data, such as GPS, terrestrial laserscans and DInSAR into a new field which integrates the information from all the measurement techniques. The new displacements field is obtained using the well-know approach of 3DVAR used in atmospheric science to assimilated data in dynamical models. This approach produces the best observing field combining the information from different sources and minimizing the errors and the uncertainties associated to each native field (in our case GPS, laserscans and InSAR data). The methodology was developed during the Interreg-funded research project SloMove, (www.SloMove.eu) which dealt with the monitoring of slow moving processes in high alpine environments. During the project duration (2012 - 2014), rock glacier movements and deformations in Switzerland and Italy were regularly monitored using satellite-based DInSAR, terrestrial laserscanning and differential GNSS. A major challenge of the project was to integrate terrestrial and remotely-sensed data sources and to investigate the benefits and limitations of the methods and their application in an alpine setting. GPS campaigns were carried out one time in 2012 and three times a year in 2013 and 2014, terrestrial laserscans once a year. Artificial reflectors were installed on the test sites with the aim of improving the application of satellite-based DInSAR analyses. Radar data from the Cosmo SkyMed satellite was processed using the SBAS algorithm. The study was carried out at two test-sites located in Grisons (Switzerland) and South Tyrol (Italy). The Swiss site is located above Pontresina in the Upper Engadin valley. The monitoring area includes three individual active rock glaciers in a West oriented mountain cirque called Foura da l'amd Ursina. The rock glaciers are

  2. A wearable airbag to prevent fall injuries.

    PubMed

    Tamura, Toshiyo; Yoshimura, Takumi; Sekine, Masaki; Uchida, Mitsuo; Tanaka, Osamu

    2009-11-01

    We have developed a wearable airbag that incorporates a fall-detection system that uses both acceleration and angular velocity signals to trigger inflation of the airbag. The fall-detection algorithm was devised using a thresholding technique with an accelerometer and gyro sensor. Sixteen subjects mimicked falls, and their acceleration waveforms were monitored. Then, we developed a fall-detection algorithm that could detect signals 300 ms before the fall. This signal was used as a trigger to inflate the airbag to a capacity of 2.4 L. Although the proposed system can help to prevent fall-related injuries, further development is needed to miniaturize the inflation system.

  3. 4. View of Great Falls of the Potomac River looking ...

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

    4. View of Great Falls of the Potomac River looking upriver from a lower point further downstream than view #2. Observation Tower visible on left. During flood conditions of 1936 and 1942, lower portion of this tower was under water. Low water conditions are clearly evidenced here by normal water markings on rock formations noted on right. In rear of front rock promontory, a sand beach is shown. Mr. Horyduzak, photographer, 1943. - Potowmack Company: Great Falls Canal & Locks, Great Falls, Fairfax County, VA

  4. Talking Rocks.

    ERIC Educational Resources Information Center

    Rice, Dale; Corley, Brenda

    1987-01-01

    Discusses some of the ways that rocks can be used to enhance children's creativity and their interest in science. Suggests the creation of a dramatic production involving rocks. Includes basic information on sedimentary, igneous, and metamorphic rocks. (TW)

  5. Talking Rocks.

    ERIC Educational Resources Information Center

    Rice, Dale; Corley, Brenda

    1987-01-01

    Discusses some of the ways that rocks can be used to enhance children's creativity and their interest in science. Suggests the creation of a dramatic production involving rocks. Includes basic information on sedimentary, igneous, and metamorphic rocks. (TW)

  6. Geomorphological analysis, monitoring and modeling of large rock avalanches in northern Chile (Iquique area) for regional hazard assessment.

    NASA Astrophysics Data System (ADS)

    Yugsi Molina, F. X.; Hermanns, R. L.; Crosta, G. B.; Dehls, J.; Sosio, R.; Sepúlveda, S. A.

    2012-04-01

    Iquique is a city of about 215,000 inhabitants (Chilean national census 2002) settled on one of the seismic gaps in the South American subduction zone, where a M >8 earthquake with overdue return periods of ca. 100 yr is expected in the near future. The city has only two access roads coming from the east and south. The road to the east comes down along the escarpment that connects the Coastal Cordillera to the Coastal Plain. The road has been blocked by small magnitude earthquake-triggered landslides at least once in recent years. The second road, coming from the south, crosses along the Coastal Plain and connects the city to the airport where at least ten ancient debris deposits related to rock avalanches are found. These facts show the importance of determining the effects of a future high magnitude earthquake on the stability of the slopes in the area and the impact of possible slope failures on people, infrastructure and emergency management. The present work covers an area of approximately 130 km2 parallel to the coastline to the south of Iquique, divided into the two main morphological units briefly mentioned above. The eastern part corresponds to the Coastal Cordillera, a set of smoothed hills and shallow valleys that reaches up to 1200 m asl. This sector is limited to the west by a steep escarpment followed by the Coastal Plain and a narrow emerged marine plateau (1-3 km wide) locally overlaid by deposits of recent rock avalanches. Rock avalanche events have recurrently occurred at two sites to the north and center of the study area on the Coastal Cordillera escarpment. Another major single event has been mapped to the south. Marls, red and black shales, and shallow marine glauconitic deposits from Jurassic constitute the source rock for the rock avalanches in all sites. Clusters of deposits are found in the first two sites (retrogressive advance) with younger events running shorter distances and partially overlaying the older ones. Multiple lobes have been

  7. Snow-cover dynamics monitored by automatic digital photography at the rooting zone of an active rock glacier in the Hinteres Lantal Cirque, Austria

    NASA Astrophysics Data System (ADS)

    Kellerer-Pirklbauer, Andreas; Rieckh, Matthias; Avian, Michael

    2010-05-01

    Knowledge regarding snow-cover dynamics and climatic conditions in the rooting zone of active rock glaciers is still limited. The number of meteorological stations on the surface of or close to active rock glaciers is increasing. However, areal information on snow-cover distribution and its spatial dynamics caused by different processes on rock glaciers surfaces with a high temporal resolution from such remote alpine areas are mostly difficult to obtain. To face this problem an automatic remote digital camera (RDC) system was proprietary developed. The core parts of the RDC system are a standard hand-held digital camera, a remote control, a water proof casing with a transparent opening, a 12V/25Ah battery and solar panels with a charge controller. Three such devices were constructed and installed at different sites in the Central Alps of Austria. One RDC system is used to monitor the rooting zone of the highly active rock glacier in the Hinteres Langtal Cirque (46°59'N, 12°47'E), Central Schober Mountains, Austria. The 0.15 km² large NW-facing rock glaciers is tongue-shaped with a fast moving lower part (>1m/a) and a substantially slower upper part, ranging in elevation between 2455-2700 m a.s.l. The RDC system was set up in September 2006 and is located since than at 2770 m a.s.l. on a pronounced ridge crest that confines the Hinteres Langtal Cirque to the SW. The water proof casing was attached to a 1.5 m high metal pole which itself was fixed to the bedrock by screws and concrete glue. The viewing direction of the camera is NE. Hence, the image section of the RDC focuses on the rooting zone of the rock glacier and its headwalls up to c. 3000 m a.s.l. Photographs were taken daily at 3 pm providing the optimal lighting conditions in the relevant part of the cirque. 720 photographs were taken continuously in the period 12.09.2006 to 31.08.2008. These optical data were analysed by applying GIS and remote sensing techniques regarding snow-cover distribution

  8. Annual Post-Closure Inspection and Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada, Rev. No.: 0

    SciTech Connect

    Alfred Wickline

    2006-09-01

    This report presents the data collected during field activities and quarterly soil-gas sampling activities conducted from May 9, 2005, through May 20, 2006, at Corrective Action Unit (CAU) 329, Area 22 Desert Rock Airstrip (DRA) Fuel Spill; Corrective Action Site (CAS) 22-44-01, Fuel Spill. The CAU is located at the DRA, which is located approximately two miles southwest of Mercury, Nevada, as shown in Figure 1-1. Field activities were conducted in accordance with the revised sampling approach outlined in the Addendum to the Closure Report (CR) for CAU 329 (NNSA/NSO, 2005) to support data collection requirements. The previous annual monitoring program for CAU 329 was initiated in August 2000 using soil-gas samples collected from three specific intervals at the DRA-0 and DRA-3 monitoring wells. Results of four sampling events from 2000 through 2003 indicated there is uncertainty in the approach to establish a rate of natural attenuation as specified in ''Streamlined Approach for Environmental Restoration (SAFER) Work Plan for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada'' (DOE/NV, 1999). As a result, the Addendum to the CR (NNSA/NSO, 2005) was completed to address this uncertainty by modifying the previous approach. A risk evaluation was added to the scope of the project to determine if the residual concentration of the hazardous constituents of JP4 pose an unacceptable risk to human health or the environment and if a corrective action was required at the site, because the current quarterly monitoring program is not expected to yield a rate constant that could be used effectively to determine a biodegradation rate for total petroleum hydrocarbons (TPH) in less than the initial five years outlined in the CR. Additionally, remediation to the Tier 1 action level for TPH is not practical or technically feasible due to the depth of contamination.

  9. Effects of fluid-rock interactions in arkosic sandstones: Long-term direct monitoring of changes in permeability, electrical conductivity, and pore fluid chemistry

    NASA Astrophysics Data System (ADS)

    Schepers, A.; Milsch, H.

    2009-04-01

    In the context of low enthalpy geothermal energy production from deep sedimentary reservoirs laboratory experiments and simulations in the system quartz-feldspar-water were conducted. To constrain the effect of fluid-rock interactions on permeability under hydrothermal in situ conditions an interdisciplinary approach covering petrophysical, petrological and hydrogeochemical methods was applied. Long-term flow-through experiments were conducted under hydrostatic pressure conditions in a HPT-permeameter. Two arkosic sandstones, one pure quartz arenite (Fontainebleau) as well as one sandwich sample containing a quartz-feldspar powder of defined grain size and composition were investigated. The pore fluid was distilled water. At a maximum temperature of 160°C both permeability and electrical rock conductivity were simultaneously monitored. The maximum run duration was three months. Complementary batch experiments were performed with quartz-feldspar powders to constrain the mechanisms and kinetics of potentially occurring hydrothermal reactions. The resulting fluids were analysed with ICP-OES and the reacted powders were characterised with XRD and SEM. Additionally, the hydrothermal reactions were modelled with PHREEQC. It will be demonstrated that permeability decreases in the course of the experiments. However, compared to similar experiments conducted under deviatoric stress conditions (Tenthorey et al., 1998) the decrease in permeability is low. For both arkosic sandstones and at stagnant flow conditions the electrical rock conductivity showed an asymptotical increase indicating that the respective pore fluid approaches a saturation state. Furthermore, fluid samples taken at the end of the Fontainebleau experiment exhibit supersaturation with respect to quartz. In addition, PHREEQC simulations of the feldspar-quartz-water equilibrium indicate that different clay minerals and gibbsite are supersaturated in the resulting fluid. Consequently and despite the sluggish

  10. Geochronology and monitoring of cosmic rays for accumulating cosmogenic isotopes 53Mn and 10Be in terrestrial rocks

    NASA Astrophysics Data System (ADS)

    Yants, V. E.; Lebedev, S. G.; Sobolevsky, N. M.

    2017-09-01

    The paper is devoted to discussing the method of measuring the accumulation of radioactive isotopes 53Mn (with a half-life T = 3.7 million years) and 10Be ( T = 2.5 million years) in iron-bearing rocks. Knowledge of the dynamics of the accumulation of these isotopes would allow us to estimate the variations in the intensity of cosmic rays, periods of glaciations and geological changes, as well as climatic processes on the Earth in retrospect of 0.1-10 million years. For an operative study of a large number of samples, it has been proposed to use a low-cost neutron activation method with the implementation of the 53Mn( n, γ)54Mn reaction in a slow neutron reactor. As has been shown, using the 10Be isotope together with 53Mn makes it possible to simultaneously determine both the cosmic-ray fluxes and the shielding time of the corresponding region from cosmic radiation. To obtain the reliable data on cosmic rays, it has been proposed to study rock samples from the lunar surface.

  11. Results of electromagnetic and seismic monitoring of the state of rock massive by use the approach of the open dynamical systems

    NASA Astrophysics Data System (ADS)

    Hachay, O. A.; Khachay, O. Yu.

    2009-04-01

    Rock massif is an open dynamical system. We did an attempt to show the relation of our received earlier results with the developed physical and mathematical theory of the research of the state of the open dynamical conservative and dissipative systems to which relate also rock massive which are in the process of outworking. That thesis is presented quantitative with use of the phase portraits constructed with use of the phase coordinates as the parameters of the integral and interval intensity for the zones of heterogeneity of the second rank and their difference analogue of the time derivatives, which are defined by the use of active induction electromagnetic monitoring data. We provided re-search, which are set on the development of criterions for estimating the stability state of rock massive, using the 6- years electromagnetic and seismic data on two mines. The results lead to such conclusions: by the outworking of the concrete block of the massif the whole massif of the mine field has a change of the stress-deformed and phase states from one explosion to another, - the amount of absorbed and returned energy is not equal and therefore in the massif we see the energy storage,- the process of the energy returning develops with a time delay and depends very much from the gradient of the absorbed energy from high energy explosions,- in the massif occur zones of dynamical calm. That zones we can observe by the data of seismological monitoring - after the end of the minimum of the calm we have during one or two weeks till the moment of the technological gob caving to provide the space-time active electromagnetic or seismic monitoring for revealing the unstable zones of the second rank,-that zones can be after the explosion the sources of high energy dynamical events. That paper is devoted also to the analysis of the morphology of structure peculiarities of the disintegration zones before the high energy dynamical event. During the regular cycle of electromagnetic

  12. CO2 leakage up from a geological storage site to shallow fresh groundwater: CO2-water-rock interaction assessment and development of sensitive monitoring

    NASA Astrophysics Data System (ADS)

    Humez, Pauline; Audigane, Pascal; Lions, Julie; Négrel, Philippe; Lagneau, Vincent

    2010-05-01

    The assessment of environmental impacts of carbon dioxide storage in geological repository requires the investigation of the potential CO2 leakage back into fresh groundwater, particularly with respect to protected groundwater reserves. We are starting a new project with the aims of developing sensitive monitoring techniques in order to detect potential CO2 leaks and their magnitude as well as their geochemical impacts on the groundwater. In a predictive approach goal, a modelling study of the geochemical impact on fresh groundwaters of a CO2 intrusion during geological storage was performed and serves as a basis for the development of sensitive monitoring techniques (e.g. isotope tracing). Then, isotopic monitoring opportunities will be explored. A modeling study of the geochemical impact on fresh groundwaters of the ingress of CO2 during geological storage was conducted. The 3D model includes (i) storage saline aquifer, (ii) impacted overlying aquifer containing freshwater and (iii) a leakage path way up through an abandoned well represented as 1D porous medium and corresponding to the cement-rock formation interface. This model was used to simulate the supercritical CO2 migration path and the interaction between the fluid and the host rock. The model uses the carbonate saline Dogger aquifer in the Paris Basin as the storage reservoir and the Albian formation (located above the Dogger) as the fresh groundwater aquifer. The principal geochemical process simulated is the acidification of groundwaters due to CO2 dissolution, inducing the dissolution of minerals in the Albian formation. Knowing the mineralogical composition of the impacted aquifer is therefore crucial if we are to correctly determine which elements might be release during the arrival of CO2 in freshwater. Estimates of increases in element concentrations are proposed along with a direct control of the injection procedure. This predictive modeling approach impact of CO2 intrusion to fresh groundwaters

  13. Evaluation of site-selection criteria, well design, monitoring techniques, and cost analysis for a ground-water supply in Piedmont crystalline rocks, North Carolina

    USGS Publications Warehouse

    Daniel, Charles C.

    1990-01-01

    A statistical analysis of data from wells drilled into the crystalline rocks of the Piedmont and Blue Ridge provinces of North Carolina verified and refined previously proposed criteria for the siting of wells to obtain greater than average yields. An opportunity to test the criteria was provided by the expansion of the town of Cary's municipal ground-water system. Three criteria were used: type of rock, thickness of saturated regolith based upon topography, and presence of fractures and joints based upon drainage lineations. A conceptual model of the local hydrogeologic system was developed to guide the selection of the most favorable well sites, and on the basis of the model, six type sites were determined. Eleven of 12 test wells that were located on the basis of type sites yielded from slightly above average to as much as six times the average yield to be expected from particular rock types as reported in the literature. Only one well drilled at a type site had a less than average yield. One well not located at any of the type sites produced little water. Long-term testing and monitoring after the wells were put into production showed that an 18-hour-on, 6-hour-off pumping cycle was much more effective in terms of total production, reduced head loss, and less drawdown than a 5-day-on and 2-day-off cycle. It was also observed that long-term yields by the production wells were about 75 percent of those predicted on the basis of 24-hour pumping tests and only about 60 percent of the driller's reported yields. Cost analysis showed that, by using criteria-selected well sites, a cost-effective well system can be developed that will provide water at an equivalent or lower cost than a surface-water supply. The analysis showed that the system would be cost effective if only one high-yield well were obtained out of every four drilled.

  14. Analysis of microseismic signals and temperature recordings for rock slope stability investigations in high mountain areas

    NASA Astrophysics Data System (ADS)

    Occhiena, C.; Coviello, V.; Arattano, M.; Chiarle, M.; Morra di Cella, U.; Pirulli, M.; Pogliotti, P.; Scavia, C.

    2012-07-01

    The permafrost degradation is a probable cause for the increase of rock instabilities and rock falls observed in recent years in high mountain areas, particularly in the Alpine region. The phenomenon causes the thaw of the ice filling rock discontinuities; the water deriving from it subsequently freezes again inducing stresses in the rock mass that may lead, in the long term, to rock falls. To investigate these processes, a monitoring system composed by geophones and thermometers was installed in 2007 at the Carrel hut (3829 m a.s.l., Matterhorn, NW Alps). In 2010, in the framework of the Interreg 2007-2013 Alcotra project no. 56 MASSA, the monitoring system has been empowered and renovated in order to meet project needs. In this paper, the data recorded by this renewed system between 6 October 2010 and 5 October 2011 are presented and 329 selected microseismic events are analysed. The data processing has concerned the classification of the recorded signals, the analysis of their distribution in time and the identification of the most important trace characteristics in time and frequency domain. The interpretation of the results has evidenced a possible correlation between the temperature trend and the event occurrence. The research is still in progress and the data recording and interpretation are planned for a longer period to better investigate the spatial-temporal distribution of microseismic activity in the rock mass, with specific attention to the relation of microseismic activity with temperatures. The overall goal is to verify the possibility to set up an effective monitoring system for investigating the stability of a rock mass under permafrost conditions, in order to supply the researchers with useful data to better understand the relationship between temperature and rock mass stability and, possibly, the technicians with a valid tool for decision-making.

  15. Fall Protection Introduction, #33462

    SciTech Connect

    Chochoms, Michael

    2016-06-23

    The proper use of fall prevention and fall protection controls can reduce the risk of deaths and injuries caused by falls. This course, Fall Protection Introduction (#33462), is designed as an introduction to various types of recognized fall prevention and fall protection systems at Los Alamos National Laboratory (LANL), including guardrail systems, safety net systems, fall restraint systems, and fall arrest systems. Special emphasis is given to the components, inspection, care, and storage of personal fall arrest systems (PFASs). This course also presents controls for falling object hazards and emergency planning considerations for persons who have fallen.

  16. Pumping tests in a low permeability rock: Results and interpretation of a four-year long monitoring of water production flow rates in the Callovo-Oxfordian argillaceous rock

    NASA Astrophysics Data System (ADS)

    Vinsot, A.; Delay, J.; de La Vaissière, R.; Cruchaudet, M.

    Hydraulic conductivity of the Callovo-Oxfordian argillaceous rock ranges between 10 -14 and 10 -12 m/s. In spite of these low values, long term ‘pumping tests’ covering a range of head differentials have been performed in several boreholes in the Andra Meuse/Haute-Marne Underground Research Laboratory (URL). Specifically designed experimental setups made it possible to monitor water production flow rates ranging from 0.5 to 50 mL/day, during more than 4 years. Long term pumping tests provided an alternative to the pressure test method for evaluating hydraulic conductivities at the -430 m and -505 m depth levels in the URL. The obtained values were close to 0.8 × 10 -13 m/s and 1.3 × 10 -13 m/s, respectively. The lowest flow rate measured under well-established hydraulic head boundary conditions was close to 2.5 mL/day. It corresponds to a calculated hydraulic gradient value less than 120 m/m. This result indicates that water can flow in the Callovo-Oxfordian with such a hydraulic gradient value.

  17. Monitoring of CO2/H2S gas mixture injection in basaltic rocks at Hellisheiði Geothermal Power Plant, Iceland

    NASA Astrophysics Data System (ADS)

    Clark, Deirdre E.; Gunnarsson, Ingvi; Aradóttir, Edda S.; Gunnlaugsson, Einar; Júlíusson, Bjarni M.; Matter, Juerg M.; Stute, Martin; Oelkers, Eric H.; Snæbjörnsdóttir, Sandra Ó.; Gíslason, Sigurður R.

    2016-04-01

    Hellisheiði geothermal power plant emits about 41,000 tonnes of CO2 and 10,000 tonnes of H2S per year as a by-product of geothermal energy production. Icelandic regulations, stricter than WHO guidelines, have been in effect in order to reduce H2S emissions of the geothermal industry, while carbon capture and storage (CCS) is one method recommended to minimise the amount of CO2 released into the atmosphere. The overall cost of CCS is dominated by that of capture and gas separation. This capture cost could be lowered by injecting gas mixtures into rocks as is now being tested at Hellisheiði geothermal power plant in SW-Iceland. There, a gas mixture of 60% CO2 and 40% H2S is dissolved in water from the plant and injected into the basaltic rocks. The CarbFix and SulFix pilot projects demonstrated solubility storage of the pure separate gases in a few minutes [1,2] and that more than 80% of the injected CO2 into basaltic rocks was mineralised within a year from its injection at 20-50°C [3]. The first phase of the gas mixture injection began on 3 June 2014, while tracer tests started three weeks later. By the end of the year 2015, approximately 6280 tonnes of CO2 and 3520 tonnes of H2S had been injected. The gases are dissolved in condensation water, mixed with waste water and injected to 750 m depth into a high temperature reservoir of 200-270°C. Water and gas samples were collected from four monitoring wells. There is a minor increase in CO2 (total dissolved carbon) and H2S (total dissolved sulphite), while the majority of major and minor elements are relatively stable. The data from monitoring wells therefore suggests that some of the injected gas mixture is already stored as minerals in the basaltic reservoir. [1] Sigfusson et al. (2015) Int. J. of Greenh. Gas Control 37, 213-219. [2] Gunnarsson et al. (2013) GRC Transactions 37, 785-789. [3] Matter et al. (2014) Energy Procedia 63, 4180-4185.

  18. Monitoring and modeling ice-rock avalanches from ice-capped volcanoes: A case study of frequent large avalanches on Iliamna Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    Huggel, Christian; Caplan-Auerbach, Jacqueline; Waythomas, Christopher F.; Wessels, Rick L.

    2007-11-01

    Iliamna is an andesitic stratovolcano of the Aleutian arc with regular gas and steam emissions and mantled by several large glaciers. Iliamna Volcano exhibits an unusual combination of frequent and large ice-rock avalanches in the order of 1 × 10 6 m 3 to 3 × 10 7 m 3 with recent return periods of 2-4 years. We have reconstructed an avalanche event record for the past 45 years that indicates Iliamna avalanches occur at higher frequency at a given magnitude than other mass failures in volcanic and alpine environments. Iliamna Volcano is thus an ideal site to study such mass failures and its relation to volcanic activity. In this study, we present different methods that fit into a concept of (1) long-term monitoring, (2) early warning, and (3) event documentation and analysis of ice-rock avalanches on ice-capped active volcanoes. Long-term monitoring methods include seismic signal analysis, and space-and airborne observations. Landsat and ASTER satellite data was used to study the extent of hydrothermally altered rocks and surface thermal anomalies at the summit region of Iliamna. Subpixel heat source calculation for the summit regions where avalanches initiate yielded temperatures of 307 to 613 K assuming heat source areas of 1000 to 25 m 2, respectively, indicating strong convective heat flux processes. Such heat flow causes ice melting conditions and is thus likely to reduce the strength at the base of the glacier. We furthermore demonstrate typical seismic records of Iliamna avalanches with rarely observed precursory signals up to two hours prior to failure, and show how such signals could be used for a multi-stage avalanche warning system in the future. For event analysis and documentation, space- and airborne observations and seismic records in combination with SRTM and ASTER derived terrain data allowed us to reconstruct avalanche dynamics and to identify remarkably similar failure and propagation mechanisms of Iliamna avalanches for the past 45 years

  19. Monitoring and modeling ice-rock avalanches from ice-capped volcanoes: A case study of frequent large avalanches on Iliamna Volcano, Alaska

    USGS Publications Warehouse

    Huggel, C.; Caplan-Auerbach, J.; Waythomas, C.F.; Wessels, R.L.

    2007-01-01

    Iliamna is an andesitic stratovolcano of the Aleutian arc with regular gas and steam emissions and mantled by several large glaciers. Iliamna Volcano exhibits an unusual combination of frequent and large ice-rock avalanches in the order of 1 ?? 106??m3 to 3 ?? 107??m3 with recent return periods of 2-4??years. We have reconstructed an avalanche event record for the past 45??years that indicates Iliamna avalanches occur at higher frequency at a given magnitude than other mass failures in volcanic and alpine environments. Iliamna Volcano is thus an ideal site to study such mass failures and its relation to volcanic activity. In this study, we present different methods that fit into a concept of (1) long-term monitoring, (2) early warning, and (3) event documentation and analysis of ice-rock avalanches on ice-capped active volcanoes. Long-term monitoring methods include seismic signal analysis, and space-and airborne observations. Landsat and ASTER satellite data was used to study the extent of hydrothermally altered rocks and surface thermal anomalies at the summit region of Iliamna. Subpixel heat source calculation for the summit regions where avalanches initiate yielded temperatures of 307 to 613??K assuming heat source areas of 1000 to 25??m2, respectively, indicating strong convective heat flux processes. Such heat flow causes ice melting conditions and is thus likely to reduce the strength at the base of the glacier. We furthermore demonstrate typical seismic records of Iliamna avalanches with rarely observed precursory signals up to two hours prior to failure, and show how such signals could be used for a multi-stage avalanche warning system in the future. For event analysis and documentation, space- and airborne observations and seismic records in combination with SRTM and ASTER derived terrain data allowed us to reconstruct avalanche dynamics and to identify remarkably similar failure and propagation mechanisms of Iliamna avalanches for the past 45??years

  20. Rock Deformation Meeting

    NASA Astrophysics Data System (ADS)

    Green, Harry

    The Third Rock Deformation Colloquium was held December 4, 1989, at the AGU Fall Meeting in San Francisco. Steve Kirby of the U.S. Geological Survey, Menlo Park, Calif., reported on actions taken by the rock deformation steering committee. Brian Wernicke of Harvard University, Cambridge, Mass., talked on the structural geology of the Great Basin.The steering committee voted for “Committee on Deformation of Earth Materials” as the name for the AGU technical committee on rock deformation, Kirby said. Considerable discussion has occurred in the steering committee over our relationship to the AGU Mineral Physics Committee. Indeed, Kirby will become chairman of that committee in 1990, underlining the overlap of the two groups. It was agreed that we will pursue closer association with Mineral Physics.

  1. "Rock Garden"

    NASA Image and Video Library

    1997-10-14

    This false color composite image of the Rock Garden shows the rocks "Shark" and "Half Dome" at upper left and middle, respectively. Between these two large rocks is a smaller rock (about 0.20 m wide, 0.10 m high, and 6.33 m from the Lander) that was observed close-up with the Sojourner rover (see PIA00989). http://photojournal.jpl.nasa.gov/catalog/PIA00987

  2. Science Rocks!

    ERIC Educational Resources Information Center

    Prestwich, Dorothy; Sumrall, Joseph; Chessin, Debby A.

    2010-01-01

    It all began one Monday morning. Raymond could not wait to come to large group. In his hand, he held a chunk of white granite he had found. "Look at my beautiful rock!" he cried. The rock was passed around and examined by each student. "I wonder how rocks are made?" wondered one student. "Where do they come from?"…

  3. Rock Finding

    ERIC Educational Resources Information Center

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  4. Rock Art

    ERIC Educational Resources Information Center

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  5. Collecting Rocks.

    ERIC Educational Resources Information Center

    Barker, Rachel M.

    One of a series of general interest publications on science topics, the booklet provides those interested in rock collecting with a nontechnical introduction to the subject. Following a section examining the nature and formation of igneous, sedimentary, and metamorphic rocks, the booklet gives suggestions for starting a rock collection and using…

  6. Science Rocks!

    ERIC Educational Resources Information Center

    Prestwich, Dorothy; Sumrall, Joseph; Chessin, Debby A.

    2010-01-01

    It all began one Monday morning. Raymond could not wait to come to large group. In his hand, he held a chunk of white granite he had found. "Look at my beautiful rock!" he cried. The rock was passed around and examined by each student. "I wonder how rocks are made?" wondered one student. "Where do they come from?"…

  7. Rock Art

    ERIC Educational Resources Information Center

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  8. Rock Finding

    ERIC Educational Resources Information Center

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  9. Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook salmon ESU, 1/1/2014 - 12/31/2014

    USGS Publications Warehouse

    Connor, William P.; Mullins, Frank L; Tiffan, Kenneth F.; Perry, Russell W.; Erhardt, John M.; St John, Scott J.; Bickford, Brad; Rhodes, Tobyn

    2015-01-01

    The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2014 in association with U.S. Endangered Species Act recovery efforts and other Federally mandated actions. This annual report focuses on (1) numeric and habitat use responses by natural- and hatchery-origin spawners, (2) phenotypic and numeric responses by natural-origin juveniles, and (3) predator responses in the Snake River upper and lower reaches as abundance of adult and juvenile fall Chinook Salmon increased. Spawners have located and used most of the available spawning habitat and that habitat is gradually approaching redd capacity. Timing of spawning and fry emergence has been relatively stable; whereas the timing of parr dispersal from riverine rearing habitat into Lower Granite Reservoir has become earlier as apparent abundance of juveniles has increased. Growth rate (g/d) and dispersal size of parr also declined as apparent abundance of juveniles increased. Passage timing of smolts from the two Snake River reaches has become earlier and downstream movement rate faster as estimated abundance of fall Chinook Salmon smolts in Lower Granite Reservoir has increased. In 2014, consumption of subyearlings by Smallmouth Bass was highest in the upper reach which had the highest abundance of Bass. With a few exceptions, predation tended to decrease seasonally from April through early July. A release of hatchery fish in mid-May significantly increased subyearling consumption by the following day. We estimated that over 600,000 subyearling fall Chinook Salmon were lost to Smallmouth Bass predation along the free-flowing Snake River in 2014. More information on predation is presented in Appendix A.3 (page 51). These findings coupled with stock-recruitment analyses presented in this report provide evidence for density-dependence in the Snake River reaches and in Lower Granite Reservoir that was

  10. Fall Enrollment Report. 2014

    ERIC Educational Resources Information Center

    Iowa Department of Education, 2014

    2014-01-01

    This report summarizes and analyzes fall enrollment in Iowa's community colleges. Each year, Iowa's 15 community colleges submit data on enrollment on the 10th business day of the fall semester. Some highlights from this report include: (1) Fall 2014 enrollment was 93,772 students--a decline of 0.49 percent from last fall; (2) Enrollment continues…

  11. Groundwater resource vulnerability and spatial variability of nitrate contamination: Insights from high density tubewell monitoring in a hard rock aquifer.

    PubMed

    Buvaneshwari, Sriramulu; Riotte, Jean; Sekhar, M; Mohan Kumar, M S; Sharma, Amit Kumar; Duprey, Jean Louis; Audry, Stephane; Giriraja, P R; Praveenkumarreddy, Yerabham; Moger, Hemanth; Durand, Patrick; Braun, Jean-Jacques; Ruiz, Laurent

    2017-02-01

    Agriculture has been increasingly relying on groundwater irrigation for the last decades, leading to severe groundwater depletion and/or nitrate contamination. Understanding the links between nitrate concentration and groundwater resource is a prerequisite for assessing the sustainability of irrigated systems. The Berambadi catchment (ORE-BVET/Kabini Critical Zone Observatory) in Southern India is a typical example of intensive irrigated agriculture and then an ideal site to study the relative influences of land use, management practices and aquifer properties on NO3 spatial distribution in groundwater. The monitoring of >200 tube wells revealed nitrate concentrations from 1 to 360mg/L. Three configurations of groundwater level and elevation gradient were identified: i) NO3 hot spots associated to deep groundwater levels (30-60m) and low groundwater elevation gradient suggest small groundwater reserve with absence of lateral flow, then degradation of groundwater quality due to recycling through pumping and return flow; ii) high groundwater elevation gradient, moderate NO3 concentrations suggest that significant lateral flow prevented NO3 enrichment; iii) low NO3 concentrations, low groundwater elevation gradient and shallow groundwater indicate a large reserve. We propose that mapping groundwater level and gradient could be used to delineate zones vulnerable to agriculture intensification in catchments where groundwater from low-yielding aquifers is the only source of irrigation. Then, wells located in low groundwater elevation gradient zones are likely to be suitable for assessing the impacts of local agricultural systems, while wells located in zones with high elevation gradient would reflect the average groundwater quality of the catchment, and hence should be used for regional mapping of groundwater quality. Irrigation with NO3 concentrated groundwater induces a "hidden" input of nitrogen to the crop which can reach 200kgN/ha/yr in hotspot areas, enhancing

  12. 'Escher' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks

    [figure removed for brevity, see original site] Figure 1

    This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters.

    The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water.

    Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend.

    These data were taken by the rover's alpha particle X-ray spectrometer.

  13. 'Escher' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks

    [figure removed for brevity, see original site] Figure 1

    This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters.

    The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water.

    Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend.

    These data were taken by the rover's alpha particle X-ray spectrometer.

  14. Rock slope instabilities in Norway: First systematic hazard and risk classification of 22 unstable rock slopes

    NASA Astrophysics Data System (ADS)

    Böhme, Martina; Hermanns, Reginald L.; Oppikofer, Thierry; Penna, Ivanna

    2016-04-01

    Unstable rock slopes that can cause large failures of the rock-avalanche type have been mapped in Norway for almost two decades. Four sites have earlier been characterized as high-risk objects based on expertise of few researchers. This resulted in installing continuous monitoring systems and set-up of an early-warning system for those four sites. Other unstable rock slopes have not been ranked related to their hazard or risk. There are ca. 300 other sites known of which 70 sites were installed for periodic deformation measurements using multiple techniques (Global Navigation Satellite Systems, extensometers, measurement bolts, and others). In 2012 a systematic hazard and risk classification system for unstable rock slopes was established in Norway and the mapping approach adapted to that in 2013. Now, the first 22 sites were classified for hazard, consequences and risk using this classification system. The selection of the first group of sites to be classified was based on an assumed high hazard or risk and importance given to the sites by Norwegian media and the public. Nine of the classified 22 unstable rock slopes are large sites that deform inhomogeneously or are strongly broken up in individual blocks. This suggests that different failure scenarios are possible that need to be analyzed individually. A total of 35 failure scenarios for those nine unstable rock slopes were considered. The hazard analyses were based on 9 geological parameters defined in the classification system. The classification system will be presented based on the Gamanjunni unstable rock slope. This slope has a well developed back scarp that exposes 150 m preceding displacement. The lateral limits of the unstable slope are clearly visible in the morphology and InSAR displacement data. There have been no single structures observed that allow sliding kinematically. The lower extend of the displacing rock mass is clearly defined in InSAR data and by a zone of higher rock fall activity. Yearly

  15. Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall

    NASA Astrophysics Data System (ADS)

    Amitrano, D.; Gruber, S.; Girard, L.

    2012-08-01

    Ice formation within rock is known to be an important driver of near-surface frost weathering as well as of rock damage at the depth of several meters, which may play a crucial role for the slow preconditioning of rock fall in steep permafrost areas. This letter reports results from an experiment where acoustic emission monitoring was used to investigate rock damage in a high-alpine rock-wall induced by natural thermal cycling and freezing/thawing. The analysis of the large catalog of events obtained shows (i) robust power-law distributions in the time and energy domains, a footprint of rock micro-fracturing activity induced by stresses arising from thermal variations and associated freezing/thawing of rock; (ii) an increase in AE activity under sub-zero rock-temperatures, suggesting the importance of freezing-induced stresses. AE activity further increases in locations of the rock-wall that are prone to receiving melt water. These results suggest that the framework of further modeling studies (theoretical and numerical) should include damage, elastic interaction and poro-mechanics in order to describe freezing-related stresses.

  16. Effect of Hydrothermal Alteration on Rock Properties in Active Geothermal Setting

    NASA Astrophysics Data System (ADS)

    Mikisek, P.; Bignall, G.; Sepulveda, F.; Sass, I.

    2012-04-01

    Hydrothermal alteration records the physical-chemical changes of rock and mineral phases caused by the interaction of hot fluids and wall rock, which can impact effective permeability, porosity, thermal parameters, rock strength and other rock properties. In this project, an experimental approach has been used to investigate the effects of hydrothermal alteration on rock properties. A rock property database of contrastingly altered rock types and intensities has been established. The database details horizontal and vertical permeability, porosity, density, thermal conductivity and thermal heat capacity for ~300 drill core samples from wells THM12, THM13, THM14, THM17, THM18, THM22 and TH18 in the Wairakei-Tauhara geothermal system (New Zealand), which has been compared with observed hydrothermal alteration type, rank and intensity obtained from XRD analysis and optical microscopy. Samples were selected from clay-altered tuff and intercalated siltstones of the Huka Falls Formation, which acts as a cap rock at Wairakei-Tauhara, and tuffaceous sandstones of the Waiora Formation, which is a primary reservoir-hosting unit for lateral and vertical fluid flows in the geothermal system. The Huka Falls Formation exhibits argillic-type alteration of varying intensity, while underlying Waiora Formations exhibits argillic- and propylithic-type alteration. We plan to use a tempered triaxial test cell at hydrothermal temperatures (up to 200°C) and pressures typical of geothermal conditions, to simulate hot (thermal) fluid percolation through the rock matrix of an inferred "reservoir". Compressibility data will be obtained under a range of operating (simulation reservoir) conditions, in a series of multiple week to month-long experiments that will monitor change in permeability and rock strength accompanying advancing hydrothermal alteration intensity caused by the hot brine interacting with the rock matrix. We suggest, our work will provide new baseline information concerning

  17. Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River Fall Chinook Salmon ESU, 1/1/2016 - 12/31/2016

    USGS Publications Warehouse

    Connor, William P.; Mullins, Frank L.; Tiffan, Kenneth F.; Plumb, John M.; Perry, Russell W.; Erhardt, John M.; Hemingway, Rulon; Bickford, Brad; Rhodes, Tobyn

    2017-01-01

    The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2016 in association with U.S. Endangered Species Act recovery efforts and other federally mandated actions. This annual report focuses on (1) numeric and habitat use responses by natural- and hatchery-origin spawners, (2) phenotypic and numeric responses by natural-origin juveniles, and (3) predator responses in the Snake River upper and lower reaches as abundance of adult and juvenile fall Chinook Salmon increased. Spawners have located and used most of the available spawning habitat and that habitat is gradually approaching redd capacity. Timing of spawning and fry emergence has been relatively stable; whereas the timing of parr dispersal from riverine rearing habitat into Lower Granite Reservoir has become earlier as apparent abundance of juveniles has increased. Growth rate (g/d) and dispersal size of parr also declined as apparent abundance of juveniles increased. Passage timing of smolts from the two Snake River reaches has become earlier and downstream movement rate faster as estimated abundance of fall Chinook Salmon smolts in Lower Granite Reservoir has increased. In 2016, we described estimated the consumption rate and loss of subyearlings by Smallmouth Bass before, during, and after four hatchery releases. Before releases, Smallmouth Bass consumption rates of subyearling was low (0–0.36 fish/bass/d), but the day after the releases consumption rates reached as high as 1.6 fish/bass/d. Bass consumption in the upper portion of Hells Canyon was high for about 1–2 d before returning to pre-release levels, but in the lower river consumption rates were reduced but took longer to return to pre-release levels. We estimated that most of the subyearlings consumed by bass were of hatchery origin. Smallmouth Bass predation on subyearlings is intense following a hatchery release, but the

  18. 'Earhart' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock informally named 'Earhart' on the lower slopes of 'Endurance Crater.' The rock was named after the pilot Amelia Earhart. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe fractures in Earhart could have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Rover team members do not have plans to investigate Earhart in detail because it is located across potentially hazardous sandy terrain. This image was taken on sol 219 (Sept. 4) by the rover's panoramic camera, using its 750-, 530- and 430-nanometer filters.

  19. Rock flows

    NASA Technical Reports Server (NTRS)

    Matveyev, S. N.

    1986-01-01

    Rock flows are defined as forms of spontaneous mass movements, commonly found in mountainous countries, which have been studied very little. The article considers formations known as rock rivers, rock flows, boulder flows, boulder stria, gravel flows, rock seas, and rubble seas. It describes their genesis as seen from their morphological characteristics and presents a classification of these forms. This classification is based on the difference in the genesis of the rubbly matter and characterizes these forms of mass movement according to their source, drainage, and deposit areas.

  20. Quantitative geophysics in permafrost rock walls and their explanatory power for geomechanics

    NASA Astrophysics Data System (ADS)

    Krautblatter, M.; Dräbing, D.; Funk, D.; Kemna, A.

    2012-12-01

    An increasing number of rock falls has been reported for permafrost-affected rockwalls in the last two decades. The anticipation of the hazard induced by permafrost rock slope failure requires monitoring of thermal and hydrological regimes and geomechanical properties inside the rock mass and quantitative geophysics could provide certain information on all of them. Electrical resistivity tomography (ERT) in frozen rock walls could become a key method for such investigations since freezing and sub-freezing temperature changes induce significant and recognizable changes in resistivity. Testing temperature-resistivity T-ρ relationships from a double-digit number of low-porosity sedimentary, metamorphic and igneous rocks from Alpine and Arctic permafrost rockwalls in the laboratory, we found evidence that exponential T-ρ paths developed by McGinnis et al. (1973) do not describe the resistivity behaviour of hard rocks undergoing freezing or melting correctly, as freezing occurs in confined space. We provide evidence that bilinear functions of unfrozen and frozen T-ρ paths offer a better approximation. Inferring reliable thermal state variables from ERT images requires a quantitative approach involving calibrated (T-ρ) relationships and an adequate resistance error description in the ERT inversion process, where the correct description of data errors and the right degree of data fitting are crucial issues. We also provide evidence that seismic refraction tomography is technically feasible to detect permafrost in low-porosity bedrock that constitutes steep rock walls. We have tested temperature - P-wave velocity functions of 22 decimeter-large metamorphic, magmatic and sedimentary low-porosity rock samples with a natural texture of numerous micro-fissures from alpine and arctic rock walls. The results show the significance of the ice-pressure-induced matrix velocity increase in low-porosity rocks while the velocity increase of the pore infill is negligible. Hence, the

  1. Gravity effect of water storage changes in a weathered hard-rock aquifer in West Africa: results from joint absolute gravity, hydrological monitoring and geophysical prospection

    NASA Astrophysics Data System (ADS)

    Hector, Basile; Séguis, Luc; Hinderer, Jacques; Descloitres, Marc; Vouillamoz, Jean-Michel; Wubda, Maxime; Boy, Jean-Paul; Luck, Bernard; Le Moigne, Nicolas

    2013-08-01

    Advances in groundwater storage monitoring are crucial for water resource management and hydrological processes understanding. The evaluation of water storage changes (WSC) often involve point measurements (observation wells, moisture probes, etc.), which may be inappropriate in heterogeneous media. Over the past few years, there has been an increasing interest in the use of gravimetry for hydrological studies. In the framework of the GHYRAF (Gravity and Hydrology in Africa) project, 3 yr of repeated absolute gravity measurements using a FG5-type gravimeter have been undertaken at Nalohou, a Sudanian site in northern Benin. Hydrological data are collected within the long-term observing system AMMA-Catch. Once corrected for solid earth tides, ocean loading, air pressure effects, polar motion contribution and non-local hydrology, seasonal gravity variations reach up to 11 μGal, equivalent to a WSC of 260-mm thick infinite layer of water. Absolute temporal gravity data are compared to WSC deduced from neutron probe and water-table variations through a direct modelling approach. First, we use neutronic measurements available for the whole vertical profile where WSC occur (the vadose zone and a shallow unconfined aquifer). The RMSD between observed and modelled gravity variations is 1.61 μGal, which falls within the error bars of the absolute gravity data. Second, to acknowledge for the spatial variability of aquifer properties, we use a 2-D model for specific yield (Sy) derived from resistivity mapping and Magnetic Resonance Soundings (MRS). The latter provides a water content (θMRS) known to be higher than the specific yield. Hence, we scaled the 2-D model of θMRS with a single factor (α). WSC are calculated from water-table monitoring in the aquifer layer and neutronic measurements in the vadose layer. The value of α is obtained with a Monte-Carlo sampling approach, minimizing the RMSD between modelled and observed gravity variations. This leads to α = Sy

  2. The Fall and Fall of Gary Hart.

    ERIC Educational Resources Information Center

    Rowland, Robert C.

    The fall of Gary Hart, brought about because of his indiscretions during the 1988 presidential campaign, should not be treated exclusively as a consequence of Hart's moral failings. Rather, the fall of Hart can be traced to a complex of factors including bad judgment, the near total control that the press exercises over the political agenda, and…

  3. Monitors.

    ERIC Educational Resources Information Center

    Powell, David

    1984-01-01

    Provides guidelines for selecting a monitor to suit specific applications, explains the process by which graphics images are produced on a CRT monitor, and describes four types of flat-panel displays being used in the newest lap-sized portable computers. A comparison chart provides prices and specifications for over 80 monitors. (MBR)

  4. Thermomechanical forcing of deep rock slope deformation: 2. The Randa rock slope instability

    NASA Astrophysics Data System (ADS)

    Gischig, Valentin S.; Moore, Jeffrey R.; Evans, Keith F.; Amann, Florian; Loew, Simon

    2011-12-01

    Deformation monitoring between 2004 and 2011 at the rock slope instability above Randa (Switzerland) has revealed an intriguing seasonal trend. Relative dislocation rates across active fractures increase when near-surface rock temperatures drop in the fall and decrease after snowmelt as temperatures rise. This temporal pattern was observed with different monitoring systems at the ground surface and at depths up to 68 m, and represents the behavior of the entire instability. In this paper, the second of two companion pieces, we interpret this seasonal deformation trend as being controlled by thermomechanical (TM) effects driven by near-surface temperature cycles. While Part 1 of this work demonstrated in a conceptual manner how TM effects can drive deep rock slope deformation and progressive failure, we present here in Part 2 a case study where temperature-controlled deformation trends were observed in a natural setting. A 2D discrete-element numerical model is employed, which allows failure along discontinuities and successfully reproduces the observed kinematics of the Randa instability. By implementing simplified ground surface temperature forcing, model results were able to reproduce the observed deformation pattern, and TM-induced displacement rates and seasonal amplitudes in the model are of the same order of magnitude as measured values. Model results, however, exhibit spatial variation in displacement onset times while field measurements show more synchronous change. Additional heat transfer mechanisms, such as fracture ventilation, likely create deviations from the purely transient-conductive temperature field modeled. We suggest that TM effects are especially important at Randa due to the absence of significant groundwater within the unstable rock mass.

  5. Institute for Rock Magnetism established

    NASA Astrophysics Data System (ADS)

    Banerjee, Subir K.

    There is a new focal point for cooperative research in advanced rock magnetism. The University of Minnesota in Minneapolis has established an Institute for Rock Magnetism (IRM) that will provide free access to modern equipment and encourage visiting fellows to focus on important topics in rock magnetism and related interdisciplinary research. Funding for the first three years has been secured from the National Science Foundation, the W.M. Keck Foundation, and the University of Minnesota.In the fall of 1986, the Geomagnetism and Paleomagnetism (GP) section of the AGU held a workshop at Asilomar, Calif., to pinpoint important and emerging research areas in paleomagnetism and rock magnetism, and the means by which to achieve them. In a report of this workshop published by the AGU in September 1987, two urgent needs were set forth. The first was for interdisciplinary research involving rock magnetism, and mineralogy, petrology, sedimentology, and the like. The second need was to ease the access of rock magnetists and paleomagnetists around the country to the latest equipment in modern magnetics technology, such as magneto-optics or electronoptics. Three years after the publication of the report, we announced the opening of these facilities at the GP section of the AGU Fall 1990 Meeting. A classified advertisement inviting applications for visiting fellowships was published in the January 22, 1991, issue of Eos.

  6. Meteorite Falls in Morocco

    NASA Astrophysics Data System (ADS)

    Chennaoui Aoudjehane, H.

    2016-08-01

    The number of meteorite falls reported in Morocco since 2000 is highest than any other place compared to the other countries in the world, that call into question the efficiency of the randomly meteorite falls on Earth.

  7. Falls after stroke.

    PubMed

    Batchelor, Frances A; Mackintosh, Shylie F; Said, Catherine M; Hill, Keith D

    2012-08-01

    Falls are common at all stages after stroke, occurring in the acute, rehabilitative, and chronic phases. Consequences of falls include death or serious injury, minor injuries, functional limitations, reduced mobility and activity, and fear of falling. These consequences can have implications for independence and quality of life after stroke. The high frequency of falls may be due to a combination of existing falls risk factors prior to the stroke as well as impairments from the stroke, such as decreased strength and balance, hemineglect, perceptual problems, and visual problems. This paper reviews the magnitude of the problem of falls in people with stroke, highlights risk factors, and summarizes the limited randomized controlled trial evidence on falls prevention in this population. There is a need for further high quality research investigating the effectiveness of interventions to reduce falls and injury in people with stroke from onset through to the chronic stage. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

  8. Preliminary Study on Rock Avalanche in Taiwan

    NASA Astrophysics Data System (ADS)

    Shen, Y.; Wen, Y.; Hsieh, M.

    2012-12-01

    Rock avalanche is a kind of rapid (average >100 km/h) granule flow caused by crushing and pulverization of rock materials during catastrophic rock slide. Literature researches show that rock avalanches typically occur on steep, high-relief slopes underlain by hard rocks, and have volumes >10,000,000 m3. Rock avalanches also are characterized by long runout distances, which are 5 to 10 times the total fall heights. Some cases can run up the opposing valley wall. Rock avalanches generally occurred in active mountains (e.g., New Zealand) and were triggered by earthquakes or rainfall (snowmelt), but with exceptions. There were few rock avalanches in historical time in Taiwan. This could reflect: (1) intrinsic instability of hillslopes due to weak rock, frequent earthquakes/heavy rains, which resulted in landslides of high frequency/low magnitude; (2) limited runout space along deeply incised river-valley systems, which increased the likelihood of rock-slope failures to transform to debris flows. However, there are ancient rock-avalanche records, found at Shou-shan coast (SW Taiwan) and Shin-she, Chang-pin, Tu-lan along Hua-tung coast (E Taiwan), which is likely to have undergone coseismic uplift. These places, with steep slopes, underlain by hard rock, and free for materials to run, are most prone to rock avalanches in the future.

  9. Art Rocks with Rock Art!

    ERIC Educational Resources Information Center

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  10. Art Rocks with Rock Art!

    ERIC Educational Resources Information Center

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  11. First Aid: Falls

    MedlinePlus

    ... Your 1- to 2-Year-Old First Aid: Falls KidsHealth > For Parents > First Aid: Falls Print A A A en español Folleto de instructiones: Caídas (Falls) With all the running, climbing, and exploring kids ...

  12. Falls risk assessment.

    PubMed

    Gallacher, Rose

    2017-02-22

    What was the nature of the CPD activity, practice-related feedback and/or event and/or experience in your practice? The CPD article outlined the causes and consequences of falls for older patients. It discussed the falls risk assessment tools, and falls prevention measures.

  13. Fall Prevention: Simple Tips to Prevent Falls

    MedlinePlus

    ... of falls by improving strength, balance, coordination and flexibility. If you avoid physical activity because you're ... custom exercise program aimed at improving your balance, flexibility, muscle strength and gait. Consider changing your footwear ...

  14. On the location of microseismic sources in instable rock slope areas: heterogeneous vs. homogenous 3D velocity models

    NASA Astrophysics Data System (ADS)

    Coviello, Velio; Manconi, Andrea; Occhiena, Cristina; Arattano, Massimo; Scavia, Claudio

    2013-04-01

    Rock-falls are one of the most common and hazardous phenomena occurring in mountainous areas. The formation of cracks in rocks is often accompanied by a sudden release of energy, which propagates in form of elastic waves and can be detected by a suitable transducer array. Therefore, geophones are among the most effective monitoring devices to investigate eventual precursors of rock-fall phenomena. However, the identification of an efficient procedure to forecast rock-fall occurrence in space and time is still an open challenge. In this study, we aim at developing an efficient procedure to locate microseismic sources relevant to cracking mechanisms, and thus gather indications on eventual precursors of rock-fall phenomena. Common seismic location tools usually implement homogeneous or multilayered velocity models but, in case of high slope gradients and heavily fractured rock masses, these simplifications may lead to errors on the correct estimation of the source location. Thus, we analyzed how the consideration of 3D material properties on the propagation medium may influence the location. In the framework of the Alcotra 2007-2013 Project MASSA (Medium And Small Size rock-fall hazard Assessment), a monitoring system composed by 8 triaxial geophones was installed in 2010 at the J.A. Carrel hut (3829 m a.s.l., Matterhorn, NW Italian Alps) and during the first year of operation the network recorded more than 600 natural events that exceeded a fixed threshold [1]. Despite the harsh environmental conditions of the study area, eighteen points distributed as uniformly as possible in space were selected for hammering. The artificial source dataset of known coordinates was used to constrain a 3D heterogeneous velocity model through a Simultaneous Iterative Reconstructive Technique. In order to mitigate the intrinsic uncertainties of the inversion procedure, bootstrapping was performed to extend the dataset and a statistical analysis was issued to improve the model

  15. Terby's Rocks

    NASA Technical Reports Server (NTRS)

    2006-01-01

    27 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the light-toned, layered, sedimentary rock outcrops in northern Terby Crater. Terby is located along the north edge of Hellas Planitia. The sedimentary rocks might have been deposited in a greater, Hellas-filling sea -- or not. Today, the rocks are partly covered by dark-toned sediment and debris.

    Location near: 27.2oS, 285.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  16. Opportunity Rocks!

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This high-resolution image captured by the Mars Exploration Rover Opportunity's panoramic camera shows in superb detail a portion of the puzzling rock outcropping that scientists are eagerly planning to investigate. Presently, Opportunity is on its lander facing northeast; the outcropping lies to the northwest. These layered rocks measure only 10 centimeters (4 inches) tall and are thought to be either volcanic ash deposits or sediments carried by water or wind. The small rock in the center is about the size of a golf ball.

  17. Immobility and falls.

    PubMed

    Mahoney, J E

    1998-11-01

    Immobility is a common problem for hospitalized older adults. Excessive bed rest results in multiple adverse physiologic consequences and may contribute to functional decline and increased risk for falls in the hospital setting. About 2% of hospitalized older adults fall during hospitalization. Risk factors for in-hospital falls includes cognitive impairment, mobility impairment, specific diagnoses, multiple comorbidities, and psychotropic medications. Appropriate actions to prevent immobility and falls include increasing exercise and activity levels, improving the hospital environment, and decreasing the use of psychotropic medications. Bed alarms and increased supervision for high-risk patients also may help prevent falls.

  18. Conceptual design and first results of a combined electrical resistivity and induced polarization monitoring at the Aiguille du Midi rock permafrost summit (Mont Blanc Massif, French/Italian Alps)

    NASA Astrophysics Data System (ADS)

    Krautblatter, M.; Verleysdonk, S.; Flores-Orozco, A.; Kemna, A.; Deline, P.; Ravanel, L.; Pogliotti, P.; Coviello, V.; Malet, E.

    2009-04-01

    Monitoring of systemic changes in high mountain rock permafrost proves to be of increasing significance. The association with ongoing and future climate change raises the need for monitoring schemes to enable modelling of future scenarios. Due to the high degree of tourist utilisation and the good accessibility via cable car, the Aiguille du Midi represents the ideal premises to establish a long-term monitoring site. At 3842 m a.s.l. the steep granite summit offers access to all aspects in combination with persistent ice in the rock face and different rock mechanical settings. The geophysical monitoring presented here integrates into the framework of the French-Italian PERMAdataROC project and is presently considered for the EU co-funded project PermaNET (Permafrost long-term monitoring network: www.permanet-alpinespace.eu). ERT and IP were conducted along three transects at the Aiguille du Midi in December 2008. Two transects were installed along galleries and in the rock faces that are accessible from the public platform at 3770 m a.s.l.. A further transect was installed by abseiling from the summit to the steep north and south face. The southern limb of the transect goes past the meteorological station installed in a vertical rock section. All transects were measured with a Syscal Pro device with high voltages of 800 V and we applied 48 steel electrodes per transect placed firmly in drilled holes. For optimum coverage we developed a high-resolution ERT protocol with approximately 3000 dipole-dipole measurements per array and 200 cross-borehole type measurements. Time domain IP was measured alongside to check chargeability of clefts with fine-grained fillings. Simultaneously, a survey of all important clefts was made to reference chargeability values. Both ERT and IP measurements were recorded in normal and reciprocal orientation and are used to define the error levels inherent in the measurements. A smoothness-constrained Occam's inversion is then adjusted to

  19. White Rock

    NASA Image and Video Library

    2002-05-21

    White Rock is the unofficial name for this unusual landform which was first observed during NASA Mariner 9 mission in the early 1970 and is now shown here in an image from NASA Mars Odyssey spacecraft.

  20. Rock Garden

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This false color composite image of the Rock Garden shows the rocks 'Shark' and 'Half Dome' at upper left and middle, respectively. Between these two large rocks is a smaller rock (about 0.20 m wide, 0.10 m high, and 6.33 m from the Lander) that was observed close-up with the Sojourner rover (see PIA00989).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  1. 'Lutefisk' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1

    NASA's Mars Exploration Rover Spirit used its panoramic camera to take this image of a rock called 'Lutefisk' on the rover's 286th martian day (Oct. 22, 2004). The surface of the rock is studded with rounded granules of apparently more-resistant material up to several millimeters (0.1 inch) or more across. The visible portion of Lutefisk is about 25 centimeters (10 inches) across.

  2. RadNet Air Data From Idaho Falls, ID

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Idaho Falls, ID from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  3. Development of a wearable-sensor-based fall detection system.

    PubMed

    Wu, Falin; Zhao, Hengyang; Zhao, Yan; Zhong, Haibo

    2015-01-01

    Fall detection is a major challenge in the public healthcare domain, especially for the elderly as the decline of their physical fitness, and timely and reliable surveillance is necessary to mitigate the negative effects of falls. This paper develops a novel fall detection system based on a wearable device. The system monitors the movements of human body, recognizes a fall from normal daily activities by an effective quaternion algorithm, and automatically sends request for help to the caregivers with the patient's location.

  4. Gold Veins near Great Falls, Maryland

    USGS Publications Warehouse

    Reed, John Calvin; Reed, John C.

    1969-01-01

    Small deposits of native gold are present along an anastomosing system of quartz veins and shear zones just east of Great Falls, Montgomery County, Md. The deposits were discovered in 1861 and were worked sporadically until 1951, yielding more than 5,000 ounces of gold. The vein system and the principal veins within it strike a few degrees west of north, at an appreciable angle to foliation and fold axial planes in enclosing rocks of the Wissahickon Formation of late Precambrian (?) age. The veins cut granitic rocks of Devonian or pre-Devonian age and may be as young as Triassic. Further development of the deposits is unlikely under present economic conditions because of their generally low gold content and because much of the vein system lies on park property, but study of the Great Falls vein system may be useful in the search for similar deposits elsewhere in the Appalachian Piedmont.

  5. Ferguson rock slide buries California State Highway near Yosemite National Park

    USGS Publications Warehouse

    Harp, Edwin L.; Reid, Mark E.; Godt, Jonathan W.; DeGraff, Jerome V.; Gallegos, Alan J.

    2008-01-01

    During spring 2006, talus from the toe area of a rock-block slide of about 800,000 m3 buried California State Highway 140, one of the main routes into heavily-visited Yosemite National Park, USA. Closure of the highway for 92 days caused business losses of about 4.8 million USD. The rock slide, composed of slate and phyllite, moved slowly downslope from April to June 2006, creating a fresh head scarp with 9-12 m of displacement. Movement of the main rock slide, a re-activation of an older slide, was triggered by an exceptionally wet spring 2006, following a very wet spring 2005. As of autumn 2006, most of the main slide appeared to be at rest, although rocks occasionally continued to fall from steep, fractured rock masses at the toe area of the slide. Future behavior of the slide is difficult to predict, but possible scenarios range from continued scattered rock fall to complete rapid failure of the entire mass. Although unlikely except under very destabilizing circumstances, a worst-case, rapid failure of the entire rock slide could extend across the Merced River, damming the river and creating a reservoir. As a temporary measure, traffic has been rerouted to the opposite side of the Merced River at about the same elevation as the buried section of Highway 140. A state-of-the-art monitoring system has been installed to detect movement in the steep talus slope, movement of the main slide mass, local strong ground motion from regional earthquakes, and sudden changes in stream levels, possibly indicating damming of the river by slide material.

  6. Ferguson rock slide buries California State Highway near Yosemite National Park

    USGS Publications Warehouse

    Harp, E.L.; Reid, M.E.; Godt, J.W.; DeGraff, J.V.; Gallegos, A.J.

    2008-01-01

    During spring 2006, talus from the toe area of a rock-block slide of about 800,000 m3 buried California State Highway 140, one of the main routes into heavily-visited Yosemite National Park, USA. Closure of the highway for 92 days caused business losses of about 4.8 million USD. The rock slide, composed of slate and phyllite, moved slowly downslope from April to June 2006, creating a fresh head scarp with 9-12 m of displacement. Movement of the main rock slide, a re-activation of an older slide, was triggered by an exceptionally wet spring 2006, following a very wet spring 2005. As of autumn 2006, most of the main slide appeared to be at rest, although rocks occasionally continued to fall from steep, fractured rock masses at the toe area of the slide. Future behavior of the slide is difficult to predict, but possible scenarios range from continued scattered rock fall to complete rapid failure of the entire mass. Although unlikely except under very destabilizing circumstances, a worst-case, rapid failure of the entire rock slide could extend across the Merced River, damming the river and creating a reservoir. As a temporary measure, traffic has been rerouted to the opposite side of the Merced River at about the same elevation as the buried section of Highway 140. A state-of-the-art monitoring system has been installed to detect movement in the steep talus slope, movement of the main slide mass, local strong ground motion from regional earthquakes, and sudden changes in stream levels, possibly indicating damming of the river by slide material. ?? 2008 Springer-Verlag.

  7. Minority Enrollment Trends, Catonsville Community College: Fall 84-Fall 88.

    ERIC Educational Resources Information Center

    Catonsville Community Coll., MD. Office of Institutional Research.

    The enrollment of minority students at Catonsville Community College (CCC) generally followed the same pattern of decline and growth as the student population as a whole between fall 1984 and fall 1989. Minority enrollments increased by 1.5% from fall 1984 to fall 1985, decreased by 12.2% in fall 1986, increased by 5.8% in fall 1987, and increased…

  8. Soil Rock Analyzer

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A redesigned version of a soil/rock analyzer developed by Martin Marietta under a Langley Research Center contract is being marketed by Aurora Tech, Inc. Known as the Aurora ATX-100, it has self-contained power, an oscilloscope, a liquid crystal readout, and a multichannel spectrum analyzer. It measures energy emissions to determine what elements in what percentages a sample contains. It is lightweight and may be used for mineral exploration, pollution monitoring, etc.

  9. Meteorite falls in Africa

    NASA Astrophysics Data System (ADS)

    Khiri, Fouad; Ibhi, Abderrahmane; Saint-Gerant, Thierry; Medjkane, Mohand; Ouknine, Lahcen

    2017-10-01

    The study of meteorites provides insight into the earliest history of our solar system. From 1800, about the year meteorites were first recognized as objects falling from the sky, until December 2014, 158 observed meteorite falls were recorded in Africa. Their collected mass ranges from 1.4 g to 175 kg with the 1-10 kg cases predominant. The average rate of African falls is low with only one fall recovery per 1.35-year time interval (or 0.023 per year per million km2). This African collection is dominated by ordinary chondrites (78%) just like in the worldwide falls. The seventeen achondrites include three Martian meteorite falls (Nakhla of Egypt, Tissint of Morocco and Zagami of Nigeria). Observed Iron meteorite falls are relatively rare and represent only 5%. The falls' rate in Africa is variable in time and in space. The number of falls continues to grow since 1860, 80% of which were recovered during the period between 1910 and 2014. Most of these documented meteorite falls have been recovered from North-Western Africa, Eastern Africa and Southern Africa. They are concentrated in countries which have a large surface area and a large population with a uniform distribution. Other factors are also favorable for observing and collecting meteorite falls across the African territory, such as: a genuine meteorite education, a semi-arid to arid climate (clear sky throughout the year most of the time), croplands or sparse grasslands and possible access to the fall location with a low percentage of forest cover and dense road network.

  10. Preventing falls in hospital.

    PubMed

    Pearce, Lynne

    2017-02-27

    Essential facts Falls are the most frequent adverse event reported in hospitals, usually affecting older patients. Every year, more than 240,000 falls are reported in acute hospitals and mental health trusts in England and Wales, equivalent to more than 600 a day, according to the Royal College of Physicians (RCP). But research shows that when nurses, doctors and therapists work together, falls can be reduced by 20-30%.

  11. Feet injuries in rock climbers.

    PubMed

    Schöffl, Volker; Küpper, Thomas

    2013-10-18

    While injuries of the upper extremity are widely discussed in rock climbers, reports about the lower extremity are rare. Nevertheless almost 50 percent of acute injuries involve the leg and feet. Acute injuries are either caused by ground falls or rock hit trauma during a fall. Most frequently strains, contusions and fractures of the calcaneus and talus. More rare injuries, as e.g., osteochondral lesions of the talus demand a highly specialized care and case presentations with combined iliac crest graft and matrix associated autologous chondrocyte transplantation are given in this review. The chronic use of tight climbing shoes leads to overstrain injuries also. As the tight fit of the shoes changes the biomechanics of the foot an increased stress load is applied to the fore-foot. Thus chronic conditions as subungual hematoma, callosity and pain resolve. Also a high incidence of hallux valgus and hallux rigidus is described.

  12. Feet injuries in rock climbers

    PubMed Central

    Schöffl, Volker; Küpper, Thomas

    2013-01-01

    While injuries of the upper extremity are widely discussed in rock climbers, reports about the lower extremity are rare. Nevertheless almost 50 percent of acute injuries involve the leg and feet. Acute injuries are either caused by ground falls or rock hit trauma during a fall. Most frequently strains, contusions and fractures of the calcaneus and talus. More rare injuries, as e.g., osteochondral lesions of the talus demand a highly specialized care and case presentations with combined iliac crest graft and matrix associated autologous chondrocyte transplantation are given in this review. The chronic use of tight climbing shoes leads to overstrain injuries also. As the tight fit of the shoes changes the biomechanics of the foot an increased stress load is applied to the fore-foot. Thus chronic conditions as subungual hematoma, callosity and pain resolve. Also a high incidence of hallux valgus and hallux rigidus is described. PMID:24147257

  13. The Patient Who Falls

    PubMed Central

    Tinetti, Mary E.; Kumar, Chandrika

    2013-01-01

    Falls are common health events that cause discomfort and disability for older adults and stress for caregivers. Using the case of an older man who has experienced multiple falls and a hip fracture, this article, which focuses on community-living older adults, addresses the consequences and etiology of falls; summarizes the evidence on predisposing factors and effective interventions; and discusses how to translate this evidence into patient care. Previous falls; strength, gait, and balance impairments; and medications are the strongest risk factors for falling. Effective single interventions include exercise and physical therapy, cataract surgery, and medication reduction. Evidence suggests that the most effective strategy for reducing the rate of falling in community-living older adults may be intervening on multiple risk factors. Vitamin D has the strongest clinical trial evidence of benefit for preventing fractures among older men at risk. Issues involved in incorporating these evidence-based fall prevention interventions into outpatient practice are discussed, as are the trade-offs inherent in managing older patients at risk of falling. While challenges and barriers exist, fall prevention strategies can be incorporated into clinical practice. PMID:20085954

  14. 'Wopmay' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This approximate true-color image taken by NASA's Mars Exploration Rover Opportunity shows an unusual, lumpy rock informally named 'Wopmay' on the lower slopes of 'Endurance Crater.' The rock was named after the Canadian bush pilot Wilfrid Reid 'Wop' May. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe the lumps in Wopmay may be related to cracking and alteration processes, possibly caused by exposure to water. The area between intersecting sets of cracks eroded in a way that created the lumpy appearance. Rover team members plan to drive Opportunity over to Wopmay for a closer look in coming sols. This image was taken by the rover's panoramic camera on sol 248 (Oct. 4, 2004), using its 750-, 530- and 480-nanometer filters.

  15. Monitoring

    SciTech Connect

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

    2004-11-23

    The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

  16. Characterizing a Mississippian Carbonate Reservoir for CO2-EOR and Carbon Geosequestration: Applicability of Existing Rock Physics Models and Implications to Feasibility of a Time Lapse Monitoring Program in the Wellington Oil Field, Sumner County, Kansas.

    NASA Astrophysics Data System (ADS)

    Lueck, A. J.; Raef, A. E.

    2015-12-01

    This study will focus on characterizing subsurface rock formations of the Wellington Field, in Sumner County, Kansas, for both geosequestration of carbon dioxide (CO2) in the saline Arbuckle formation and enhanced oil recovery of a depleting Mississippian oil reservoir. Multi-scale data including lithofacies core samples, X-ray diffraction, digital rock physics scans, scanning electron microscope (SEM) imaging, well log data including sonic and dipole sonic, and surface 3D seismic reflection data will be integrated to establish and/or validate a new or existing rock physics model that best represents our reservoir rock types and characteristics. We will acquire compressional wave velocity and shear wave velocity data from Mississippian and Arbuckle cores by running ultrasonic tests using an Ult 100 Ultrasonic System and a 12 ton hydraulic jack located in the geophysics lab in Thompson Hall at Kansas State University. The elastic constants Young's Modulus, Bulk Modulus, Shear (Rigidity) Modulus and Poisson's Ratio will be extracted from these velocity data. Ultrasonic velocities will also be compared to sonic and dipole sonic log data from the Wellington 1-32 well. These data will be integrated to validate a lithofacies classification statistical model, which will be and partially has been applied to the largely unknown saline Arbuckle formation, with hopes for a connection, perhaps via Poisson's ratio, allowing a time-lapse seismic feasibility assessment and potentially developing a transformation of compressional wave sonic velocities to shear wave sonic for all wells, where compressional wave sonic is available. We will also be testing our rock physics model by predicting effects of changing effective (brine + CO2 +hydrocarbon) fluid composition on seismic properties and the implications on feasibility of seismic monitoring. Lessons learned from characterizing the Mississippian are essential to understanding the potential of utilizing similar workflows for the

  17. Falls and stumbles in myotonic dystrophy.

    PubMed

    Wiles, C M; Busse, M E; Sampson, C M; Rogers, M T; Fenton-May, J; van Deursen, R

    2006-03-01

    To investigate falls and risk factors in patients with myotonic dystrophy type 1 (DM1) compared with healthy volunteers. 13 sequential patients with DM1 from different kindreds were compared with 12 healthy volunteers. All subjects were evaluated using the Rivermead Mobility Index, Performance Oriented Mobility Assessment, and modified Activities Specific Balance Confidence scale. Measures of lower limb muscle strength, gait speed, and 7-day ambulatory activity monitoring were recorded. Subjects returned a weekly card detailing stumbles and falls. 11 of 13 patients (mean age 46.5 years, seven female) had 127 stumbles and 34 falls over the 13 weeks, compared with 10 of 12 healthy subjects (34.4 years, seven female) who had 26 stumbles and three falls. Patients were less active than healthy subjects but had more falls and stumbles per 5000 right steps taken (mean (SD) events, 0.21 (0.29) v 0.02 (0.02), p = 0.007). Patients who fell (n = 6) had on average a lower Rivermead Mobility score, slower self selected gait speed, and higher depression scores than those who did not. DM1 patients stumble or fall about 10 times more often than healthy volunteers. Routine inquiry about falls and stumbles is justified. A study of multidisciplinary intervention to reduce the risk of falls seems warranted.

  18. The dynamic response of prone-to-fall columns to ambient vibrations: comparison between measurements and numerical modelling

    NASA Astrophysics Data System (ADS)

    Valentin, J.; Capron, A.; Jongmans, D.; Baillet, L.; Bottelin, P.; Donze, F.; Larose, E.; Mangeney, A.

    2017-02-01

    Seismic noise measurements (ambient vibrations) have been increasingly used in rock slope stability assessment for both investigation and monitoring purposes. Recent studies made on gravitational hazard revealed significant spectral amplification at given frequencies and polarization of the wave-field in the direction of maximum rock slope displacement. Different properties (resonance frequencies, polarization and spectral ratio amplitudes) can be derived from the spectral analysis of the seismic noise to characterize unstable rock masses. The objective here is to identify the dynamic parameters that could be used to gain information on prone-to-fall rock columns' geometry. To do so, the dynamic response of prone-to-fall columns to seismic noise has been studied on two different sites exhibiting cliff-like geometry. Dynamic parameters (main resonance frequency and spectral ratio amplitudes) that could characterize the column decoupling were extracted from seismic noise and their variations were studied taking into account the external environmental parameter fluctuations. Based on this analysis, a two-dimensional numerical model has been set up to assess the influence of the rear vertical fractures identified on both sites on the rock column motion response. Although a simple relation was found between spectral ratio amplitudes and the rock column slenderness, it turned out that the resonance frequency is more stable than the spectral ratio amplitudes to characterize this column decoupling, provided that the elastic properties of the column can be estimated. The study also revealed the effect of additional remote fractures on the dynamic parameters, which in turn could be used for detecting the presence of such discontinuities.

  19. The dynamic response of prone-to-fall columns to ambient vibrations: comparison between measurements and numerical modelling

    NASA Astrophysics Data System (ADS)

    Valentin, J.; Capron, A.; Jongmans, D.; Baillet, L.; Bottelin, P.; Donze, F.; Larose, E.; Mangeney, A.

    2016-11-01

    Seismic noise measurements (ambient vibrations) have been increasingly used in rock slope stability assessment for both investigation and monitoring purposes. Recent studies made on gravitational hazard revealed significant spectral amplification at given frequencies and polarization of the wave-field in the direction of maximum rock slope displacement. Different properties (resonance frequencies, polarization, and spectral ratio amplitudes) can be derived from the spectral analysis of the seismic noise to characterize unstable rock masses. The objective here is to identify the dynamic parameters that could be used to gain information on prone-to-fall rock columns geometry. To do so, the dynamic response of prone-to-fall columns to seismic noise has been studied on two different sites exhibiting cliff-like geometry. Dynamic parameters (main resonance frequency and spectral ratio amplitudes) that could characterize the column decoupling were extracted from seismic noise and their variations were studied taking into account the external environmental parameter fluctuations. Based on this analysis, a two-dimensional numerical model has been set up to assess the influence of the rear vertical fractures identified on both sites on the rock column motion response. Although a simple relation was found between spectral ratio amplitudes and the rock column slenderness, it turned out that the resonance frequency is more stable than the spectral ratio amplitudes to characterize this column decoupling, provided that the elastic properties of the column can be estimated. The study also revealed the effect of additional remote fractures on the dynamic parameters, which in turn could be used for detecting the presence of such discontinuities.

  20. Learning From Falling

    ERIC Educational Resources Information Center

    Joh, Amy, S.; Adolph, Karen, E.

    2006-01-01

    Walkers fall frequently, especially during infancy. Children (15, 21, 27, 33, and 39 month-olds) and adults were tested in a novel foam pit paradigm to examine age-related changes in the relationship between falling and prospective control of locomotion. In trial 1, participants walked and fell into a deformable foam pit marked with distinct…

  1. Engineering Enrollments, Fall 1984.

    ERIC Educational Resources Information Center

    Ellis, R. A.

    1985-01-01

    Provides: (1) graduate and undergraduate enrollment data for 1984, including enrollment by curriculum and by institution; (2) a 10-year summary (fall 1975 to fall 1984); and (3) women and selected minorities in undergraduate engineering (1983-84). These and other enrollment data as well as enrollment trends are discussed. (JN)

  2. Fall Leaf Portraits

    ERIC Educational Resources Information Center

    O'Hara, Cristina

    2012-01-01

    In this article, the author describes how students can create a stunning as well as economical mosaic utilizing fall's brilliantly colored leaves, preserved at their peak in color. Start by choosing a beautiful fall day to take students on a nature walk to collect a variety of leaves in different shapes, sizes, and colors. Focus on collecting a…

  3. Experiments in Free Fall

    ERIC Educational Resources Information Center

    Art, Albert

    2006-01-01

    A model lift containing a figure of Albert Einstein is released from the side of a tall building and its free fall is arrested by elastic ropes. This arrangement allows four simple experiments to be conducted in the lift to demonstrate the effects of free fall and show how they can lead to the concept of the equivalence of inertial and…

  4. Liability for falls.

    PubMed

    Fiesta, J

    1998-03-01

    Reengineering of roles, inexperienced personnel and poor communications among departments has led to an increase in patient falls--a major source of liability. While health care facilities are not liable for all falls, they are expected to take precautions based on patients' deficits.

  5. Experiments in Free Fall

    ERIC Educational Resources Information Center

    Art, Albert

    2006-01-01

    A model lift containing a figure of Albert Einstein is released from the side of a tall building and its free fall is arrested by elastic ropes. This arrangement allows four simple experiments to be conducted in the lift to demonstrate the effects of free fall and show how they can lead to the concept of the equivalence of inertial and…

  6. Preventing falls in hospital.

    PubMed

    Pearce, Lynne

    2017-01-04

    Falls are the most frequent adverse event reported in hospitals, usually affecting older patients. Every year, more than 240,000 falls are reported in acute hospitals and mental health trusts in England and Wales, equivalent to more than 600 per day, according to the Royal College of Physicians (RCP).

  7. Preventing falls in hospital.

    PubMed

    Pearce, Lynne

    2017-01-31

    Essential facts Falls are the most frequently reported adverse events in hospitals, especially among older patients. According to the Royal College of Physicians (RCP) more than 240,000 falls are reported in acute hospitals and mental health trusts in England and Wale.

  8. Classic Rock

    ERIC Educational Resources Information Center

    Beem, Edgar Allen

    2004-01-01

    While "early college" programs designed for high-school-age students are beginning to proliferate nationwide, a small New England school has been successfully educating teens for nearly four decades. In this article, the author features Simon's Rock, a small liberal arts college located in the Great Barrington, Massachusetts, that has…

  9. Brittleness Effect on Rock Fatigue Damage Evolution

    NASA Astrophysics Data System (ADS)

    Nejati, Hamid Reza; Ghazvinian, Abdolhadi

    2014-09-01

    The damage evolution mechanism of rocks is one of the most important aspects in studying of rock fatigue behavior. Fatigue damage evolution of three rock types (onyx marble, sandstone and soft limestone) with different brittleness were considered in the present study. Intensive experimental tests were conducted on the chosen rock samples and acoustic emission (AE) sensors were used in some of them to monitor the fracturing process. Experimental tests indicated that brittleness strongly influences damage evolution of rocks in the course of static and dynamic loading. AE monitoring revealed that micro-crack density induced by the applied loads during different stages of the failure processes increases as rock brittleness increases. Also, results of fatigue tests on the three rock types indicated that the rock with the most induced micro-cracks during loading cycles has the least fatigue life. Furthermore, the condition of failure surfaces of the studied rocks samples, subjected to dynamic and static loading, were evaluated and it was concluded that the roughness of failure surfaces is influenced by loading types and rock brittleness. Dynamic failure surfaces were rougher than static ones and low brittle rock demonstrate a smoother failure surface compared to high brittle rock.

  10. Fall prevention conceptual framework.

    PubMed

    Abraham, Sam

    2011-01-01

    Falls can have lasting psychological and physical consequences, particularly fractures and slow-healing processes, and patients may also lose confidence in walking. Injuries from falls lead to functional decline, institutionalization, higher health care costs, and decreased quality of life. The process related to the problem of patient falls in the hospital, using the nursing model developed by the theorist, Ida Jean Orlando, is explained in this article. The useful tool that provides guidance to marketers in this endeavor is Maslow's hierarchy of needs. During acute illness, individuals are greatly in need of satisfying their physiological needs. If these needs are not met, patients leave the hospital lacking a positive experience. Initial fall risk assessment is critical to plan intervention and individualize care plan. Interventions depend on the severity of fall risk factors.

  11. Catching a Falling Star

    NASA Astrophysics Data System (ADS)

    2004-07-01

    ESO's Very Large Telescope Obtains Unique Spectrum of a Meteor Summary While observing a supernova in a distant galaxy with the FORS instrument on ESO's Very Large Telescope at the Paranal Observatory (Chile), astronomers were incredibly lucky to obtain serendipitously a high quality spectrum of a very large meteor in the terrestrial atmosphere. The VLT spectrograph provided a well calibrated spectrum, making it a reference in this field of research. From this spectrum, the temperature of the meteor trail was estimated to be about 4600 degrees centigrade. The serendipitous spectrum reveals the telltale meteor emissions of oxygen and nitrogen atoms and nitrogen molecules. The VLT spectrum was the first to reveal the far red range where carbon emission lines are predicted; the absence of the lines puts constraints on the role of atmospheric chemistry when life started on earth. Because the VLT is tuned to observe objects far out in space, it focuses at infinity. The meteor, being "only" 100 km above the telescope, therefore appears out of focus in the field of view. PR Photo 22a/04: Meteor Caught in the Act (MASCOT) PR Photo 22b/04: Spectrum of a Meteor (FORS1/VLT) PR Photo 22c/04: Details of the Meteor Spectrum (FORS1/VLT) Astronomers' luck ESO PR Photo 22a/04 ESO PR Photo 22a/04 Meteor Caught in the Act (MASCOT) [Preview - JPEG: 426 x 400 pix - 85k] [Normal - JPEG: 851 x 800 pix - 187k] [Full Res - JPEG: 2567 x 2413 pix - 908k] Captions: ESO PR Photo 22a/04 shows the trail of a bright meteor, photographed by the Mini All-Sky Cloud Observation Tool (MASCOT) at the ESO Paranal Observatory. MASCOT consists of a small CCD camera behind a fish-eye objective. It typically takes 90s exposures every 3 minutes and helps astronomers inside the VLT Control Room to keep an eye on the sky. The main purpose of MASCOT is to monitor the clouds over Paranal but it also observes from time to time serendipitous events like meteor showers, atmospheric phenomena, artificial satellites

  12. 149. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER ...

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

    149. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER DAM; CLOSE-UP OF MAIN CANAL GATES, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  13. 97. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY ...

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

    97. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; OVERALL WEST VIEW FROM CANAL SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  14. 147. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, ...

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

    147. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, IDAHO; VIEW OF MAIN HEADGATES, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  15. 148. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER ...

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

    148. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER DAM; HEADGATES AT INLET, SOUTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  16. 98. SHOESTRING, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST ...

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

    98. SHOESTRING, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; PROFILE VIEW, SOUTH. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  17. 99. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY ...

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

    99. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; CLOSE-UP OF OUTLET SIDE OF GATES, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  18. 141. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, ...

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

    141. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, IDAHO; CLOSE-UP OF MAIN HEADGATES, RADIAL GATES INSIDE, SOUTHEAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  19. 69. September 1913 "No. 110. Placing no. 2 rock on ...

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

    69. September 1913 "No. 110. Placing no. 2 rock on top of foundation course which has been previously rolled. Experimental road section." - Crater Lake National Park Roads, Klamath Falls, Klamath County, OR

  20. DEM Simulation of Rock Shed Failure due to Rockfall Impact

    NASA Astrophysics Data System (ADS)

    Chen, Jian-An; Lin, Ming-Lang; Wang, Ching-Ping; Lo, Chia-Ming

    2013-04-01

    The rock shed is a more costly but effective traffic facility used to keep out falling rocks in Taiwan. The main function of rock shed is to let the falling rock passing through via the top slab without hitting the road users. The failure mode of the rock shed due to rockfall impact generally includes punching of top slab, flexural cracks of beam, buckling of column, and damage of foundation, etc. Even so, the failure behavior of the rock shed is still complicated and difficult to predict. Accordingly, this study adopts the discrete element program (PFC2D) to simulate the failure behavior of rock shed. A comparison with uniaxial compression test was carried out firstly to determine the micro parameters of structure elements. The model was utilized to simulate the behavior of rock shed with impact load or hitting of falling block separately. Then, a case study of present rock shed of highway NO.18 in middle Taiwan was analyzed. The result indicates that: the primary causes of rock shed failure mode include block size, falling height, impact position, and structure system. The failure mode of punching shear failure or flexural cracks is dominated by block size and falling height. The occurrence of differential settlement is related to impact position and absence of combined footing. Considering the connection of beam and column, the structure is more likely to break at the joints rather than punching of the top slab. As a result, combined footing and beam-to-column joint should be to take into account to obtain safer protection of rock shed. Keywords: rockfall disaster, PFC, rock shed, discrete element method

  1. Mineral Detector for Igneous Rocks

    NASA Astrophysics Data System (ADS)

    Ishikawa, S. T.; Hart, S. D.; Gulick, V. C.

    2010-12-01

    rocks are especially good candidates for compositional characterization based on spectral analysis. Aphanitic rocks, whose expected trends were not fully met due to the technicalities mentioned earlier, benefit from our previous imaging analysis work where visual attributes (texture and color) are obtained from color photos. Earlier experiments using 266 igneous rock samples (andesite, basalt, rhyolite, granite, granodiorite, and diorite) correctly classified rocks as felsic, intermediate, or mafic with 79%, 63%, and 58% accuracy, respectively [1]. [1] S. T. Ishikawa, V. C. Gulick. AGU 2008 Fall Mtg.

  2. Microcraters on Apollo 15 and 16 rocks

    NASA Technical Reports Server (NTRS)

    Morrison, D. A.; Mckay, D. S.; Fruland, R. M.; Moore, H. J.

    1973-01-01

    Microcrater frequency distributions, determined for 11 Apollo 16 rocks and three Apollo 15 rocks, fall into four categories. Category 1 rocks (68415, 68416, 62235) are angular, cratered on one side only, and have moderate crater densities. Category 2 rocks (60016, 66075, 61175) are subrounded, cratered on all sides, and have distributions suggestive of the steady state. Category 3 rocks (61015, 62295) are subangular and cratered on only one side, but the crater frequency distributions have some of the characteristics of category 2 rocks. Category 4 rocks (15015, 15017, 15076, 60335) are angular, cratered on only one side, and have moderated to very low crater densities. The crater frequency distributions of categories 1 and 4 have properties indicating the possibility of estimating the time they were exposed to micrometeor bombardment. Category 1 rocks appear to have been exposed for 2 to 3 m.y. These rocks, particularly 68415, 68416, and 69935, may be ejecta from South Ray Crater, indicating an age of 2 to 3 m.y. for South Ray Crater. Category 4 rocks have been exposed for much shorter periods.

  3. An Investigation of the Strength and Deformation Characteristics of Rock masses: A Case Study in an Excavation of Eskişehir-Köseköy Tunnels, Turkey

    NASA Astrophysics Data System (ADS)

    Beyhan, Sunay; Abiddin Erguler, Zeynal; Ogul, Kenan

    2015-04-01

    With increasing of high-speed rail technology in last decades, Turkey has developed many big engineering projects to connect major cities. Excavations conducted for these projects provide very important contributions in term of understanding the strength and deformation characteristics of weak rock masses belongs to various geological materials. The Ankara-Istanbul high-speed railway known as a significant project among these projects was designed in two different phases. To discuss the outcomes, experiences and challenging geological materials during construction of this tunnel, the geotechnical properties of rock masses of a tunnel named as T19 are evaluated and discussed in this study. The T19 tunnel was excavated in stratified and heavily fractured four different geological formations. Rock mass rating (RMR) system, and tunnelling quality index (Q) were utilized for the preliminary design stages of this tunnel. These engineering rock mass classifications were utilized in 135 different locations to find representative RMR and Q values for encountered rock masses during excavation. The RMR and Q values, which range between 18-52 and changing between 0.017 and 1.6 respectively, indicate that the T19 tunnel was mainly constructed in very poor and poor rock masses. Thus, shotcrete immediately was applied after face advance to prevent the fall of loose rock fragments and to minimize excessive deformation in rock, particular in very poor and poor rock masses. In addition, the deformation characteristics of the tunnel were also carefully monitored and measured by 3D-optical measuring system and conventional tape extensometer, and then required further supports were installed. Finally, the rock mass-support interactions of different geological formations were comprehensively evaluated in this study for understanding strength and deformation characteristics of weak and stratified rock masses. Keywords: Convergence, high-speed rail, rock mass, support, tunnel

  4. Poohbear Rock

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image, taken by Sojourner's front right camera, was taken when the rover was next to Poohbear (rock at left) and Piglet (not seen) as it looked out toward Mermaid Dune. The textures differ from the foreground soil containing a sorted mix of small rocks, fines and clods, from the area a bit ahead of the rover where the surface is covered with a bright drift material. Soil experiments where the rover wheels dug in the soil revealed that the cloudy material exists underneath the drift.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  5. Poohbear Rock

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image, taken by Sojourner's front right camera, was taken when the rover was next to Poohbear (rock at left) and Piglet (not seen) as it looked out toward Mermaid Dune. The textures differ from the foreground soil containing a sorted mix of small rocks, fines and clods, from the area a bit ahead of the rover where the surface is covered with a bright drift material. Soil experiments where the rover wheels dug in the soil revealed that the cloudy material exists underneath the drift.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  6. Meridiani Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    16 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the complex surfaces of some of the light- and intermediate-toned sedimentary rock exposed by erosion in eastern Sinus Meridiani. Similar rocks occur at the Mars Exploration Rover, Opportunity, site, but they are largely covered by windblown sand and granules. The dark feature with a rayed pattern is the product of a meteor impact.

    Location near: 0.8oN, 355.2oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  7. Terby's Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    25 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light-toned, layered, sedimentary rock outcrops in the crater, Terby. The crater is located on the north rim of Hellas Basin. If one could visit the rocks in Terby, one might learn from them whether they formed in a body of water. It is possible, for example, that Terby was a bay in a larger, Hellas-wide sea.

    Location near: 27.9oS, 285.7oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  8. White Rock

    NASA Technical Reports Server (NTRS)

    2005-01-01

    14 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of the famous 'White Rock' feature in Pollack Crater in the Sinus Sabaeus region of Mars. The light-toned rock is not really white, but its light tone caught the eye of Mars geologists as far back as 1972, when it was first spotted in images acquired by Mariner 9. The light-toned materials are probably the remains of a suite of layered sediments that once spread completely across the interior of Pollack Crater. Dark materials in this image include sand dunes and large ripples.

    Location near: 8.1oS, 335.1oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  9. Rafted Rock

    NASA Image and Video Library

    2016-11-09

    This area of Amazonis Planitia to the west of the large volcano Olympus Mons was once flooded with lava. A huge eruption flowed out across the relatively flat landscape. Sometimes called "flood basalt," the lava surface quickly cooled and formed a thin crust of solidified rock that was pushed along with the flowing hot liquid rock. Hills and mounds that pre-dated the flooding eruption became surrounded, forming obstructions to the relentless march of lava. In this image, these obstructions appeared to have poked up and sliced through the lava crust as the molten rock and crust moved together from west to east, over and past the stationary mounds. The result is a series of parallel grooves or channels with the obstructing mound remaining at the western end as the flow came to rest. From such images scientists can reconstruct the direction of the lava flow, potentially tracing it back to the source vent. http://photojournal.jpl.nasa.gov/catalog/PIA21204

  10. Evaluation of accelerometer-based fall detection algorithms on real-world falls.

    PubMed

    Bagalà, Fabio; Becker, Clemens; Cappello, Angelo; Chiari, Lorenzo; Aminian, Kamiar; Hausdorff, Jeffrey M; Zijlstra, Wiebren; Klenk, Jochen

    2012-01-01

    Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortality among elderly. Real-time detection of falls and their urgent communication to a telecare center may enable rapid medical assistance, thus increasing the sense of security of the elderly and reducing some of the negative consequences of falls. Many different approaches have been explored to automatically detect a fall using inertial sensors. Although previously published algorithms report high sensitivity (SE) and high specificity (SP), they have usually been tested on simulated falls performed by healthy volunteers. We recently collected acceleration data during a number of real-world falls among a patient population with a high-fall-risk as part of the SensAction-AAL European project. The aim of the present study is to benchmark the performance of thirteen published fall-detection algorithms when they are applied to the database of 29 real-world falls. To the best of our knowledge, this is the first systematic comparison of fall detection algorithms tested on real-world falls. We found that the SP average of the thirteen algorithms, was (mean ± std) 83.0% ± 30.3% (maximum value = 98%). The SE was considerably lower (SE = 57.0% ± 27.3%, maximum value = 82.8%), much lower than the values obtained on simulated falls. The number of false alarms generated by the algorithms during 1-day monitoring of three representative fallers ranged from 3 to 85. The factors that affect the performance of the published algorithms, when they are applied to the real-world falls, are also discussed. These findings indicate the importance of testing fall-detection algorithms in real-life conditions in order to produce more effective automated alarm systems with higher acceptance. Further, the present results support the idea that a large, shared real-world fall database could, potentially, provide an enhanced understanding of the fall process and the information needed to design and

  11. Evaluation of Accelerometer-Based Fall Detection Algorithms on Real-World Falls

    PubMed Central

    Bagalà, Fabio; Becker, Clemens; Cappello, Angelo; Chiari, Lorenzo; Aminian, Kamiar; Hausdorff, Jeffrey M.; Zijlstra, Wiebren; Klenk, Jochen

    2012-01-01

    Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortality among elderly. Real-time detection of falls and their urgent communication to a telecare center may enable rapid medical assistance, thus increasing the sense of security of the elderly and reducing some of the negative consequences of falls. Many different approaches have been explored to automatically detect a fall using inertial sensors. Although previously published algorithms report high sensitivity (SE) and high specificity (SP), they have usually been tested on simulated falls performed by healthy volunteers. We recently collected acceleration data during a number of real-world falls among a patient population with a high-fall-risk as part of the SensAction-AAL European project. The aim of the present study is to benchmark the performance of thirteen published fall-detection algorithms when they are applied to the database of 29 real-world falls. To the best of our knowledge, this is the first systematic comparison of fall detection algorithms tested on real-world falls. We found that the SP average of the thirteen algorithms, was (mean±std) 83.0%±30.3% (maximum value = 98%). The SE was considerably lower (SE = 57.0%±27.3%, maximum value = 82.8%), much lower than the values obtained on simulated falls. The number of false alarms generated by the algorithms during 1-day monitoring of three representative fallers ranged from 3 to 85. The factors that affect the performance of the published algorithms, when they are applied to the real-world falls, are also discussed. These findings indicate the importance of testing fall-detection algorithms in real-life conditions in order to produce more effective automated alarm systems with higher acceptance. Further, the present results support the idea that a large, shared real-world fall database could, potentially, provide an enhanced understanding of the fall process and the information needed to design

  12. Permeability and continuous gradient temperature monitoring of volcanic rocks: new insights from borehole and laboratory analysis at the Campi Flegrei caldera (Southern Italy).

    NASA Astrophysics Data System (ADS)

    Carlino, Stefano; Piochi, Monica; Tramelli, Anna; Troise, Claudia; Mormone, Angela; Montanaro, Cristian; Scheu, Bettina; Klaus, Mayer; Somma, Renato; De Natale, Giuseppe

    2016-04-01

    The pilot borehole recently drilled in the eastern caldera of Campi Flegrei (Southern Italy), during the Campi Flegrei Deep Drill Project (CFDDP) (in the framework of the International Continental Scientific Drilling Program) allowed (i) estimating on-field permeability and coring the crustal rocks for laboratory experiments, and (ii) determining thermal gradient measurements down to ca. 500 m of depth. We report here a first comparative in situ and laboratory tests to evaluate the rock permeability in the very high volcanic risk caldera of Campi Flegrei, in which ground deformations likely occur as the persistent disturbance effect of fluid circulation in the shallower geothermal system. A large amount of petro-physical information derives from outcropping welded tuffs, cores and geophysical logs from previous AGIP's drillings, which are located in the central and western part of the caldera. We discuss the expected scale dependency of rock permeability results in relation with well-stratigraphy and core lithology, texture and mineralogy. The new acquired data improve the database related to physical property of Campi Flegrei rocks, allowing a better constrain for the various fluid-dynamical models performed in the tentative to understand (and forecast) the caldera behavior. We also present the first data on thermal gradient continuously measured through 0 - to 475 m of depth by a fiber optic sensor installed in the CFDDP pilot hole. As regards, we show that the obtained values of permeability, compared with those inferred from eastern sector of the caldera, can explain the different distribution of temperature at depth, as well as the variable amount of vapor phase in the shallow geothermal system. The measured temperatures are consistent with the distribution of volcanism in the last 15 ka.

  13. Simulated unobtrusive falls detection with multiple persons.

    PubMed

    Ariani, Arni; Redmond, Stephen J; Chang, David; Lovell, Nigel H

    2012-11-01

    One serious issue related to falls among the elderly living at home or in a residential care facility is the "long lie" scenario, which involves being unable to get up from the floor after a fall for 60 min or more. This research uses a simulated environment to investigate the potential effectiveness of using wireless ambient sensors (dual-technology (microwave/infrared) motion detectors and pressure mats) to track the movement of multiple persons and to unobtrusively detect falls when they occur, therefore reducing the rate of occurrence of "long lie" scenarios. A path-finding algorithm (A*) is used to simulate the movement of one or more persons through the residential area. For analysis, the sensor network is represented as an undirected graph, where nodes in the graph represent sensors, and edges between nodes in the graph imply that these sensors share an overlapping physical region in their area of sensitivity. A second undirected graph is used to represent the physical adjacency of the sensors (even where they do not overlap in their monitored regions). These graphical representations enable the tracking of multiple subjects/groups within the environment, by analyzing the sensor activation and adjacency profiles, hence allowing individuals/groups to be isolated when multiple persons are present, and subsequently monitoring falls events. A falls algorithm, based on a heuristic decision tree classifier model, was tested on 15 scenarios, each including one or more persons; three scenarios of activity of daily living, and 12 different types of falls (four types of fall, each with three postfall scenarios). The sensitivity, specificity, and accuracy of the falls algorithm are 100.00%, 77.14%, and 89.33%, respectively.

  14. Survival of falling robots

    NASA Technical Reports Server (NTRS)

    Cameron, Jonathan M.; Arkin, Ronald C.

    1992-01-01

    As mobile robots are used in more uncertain and dangerous environments, it will become important to design them so that they can survive falls. In this paper, we examine a number of mechanisms and strategies that animals use to withstand these potentially catastrophic events and extend them to the design of robots. A brief survey of several aspects of how common cats survive falls provides an understanding of the issues involved in preventing traumatic injury during a falling event. After outlining situations in which robots might fall, a number of factors affecting their survival are described. From this background, several robot design guidelines are derived. These include recommendations for the physical structure of the robot as well as requirements for the robot control architecture. A control architecture is proposed based on reactive control techniques and action-oriented perception that is geared to support this form of survival behavior.

  15. Editors' Fall Picks

    ERIC Educational Resources Information Center

    Hoffert, Barbara; Heilbrun, Margaret; Kuzyk, Raya; Kim, Ann; McCormack, Heather; Katterjohn, Anna; Burns, Ann; Williams, Wilda

    2008-01-01

    From the fall's cascade of great new books, "Library Journal's" editors select their favorites--a dark rendition of Afghan life, a look at the "self-esteem trap," a celebration of Brooklyn activism, and much more.

  16. Seneca Falls. Classroom Focus.

    ERIC Educational Resources Information Center

    Balantic, Jeannette; Libresco, Andrea S.

    1995-01-01

    Presents a secondary school lesson based on the Seneca Falls Declaration of Sentiments. Provides lesson objectives and step-by-step instructional procedures. Includes quoted sections of the Declaration of Sentiments. (CFR)

  17. Survival of falling robots

    NASA Astrophysics Data System (ADS)

    Cameron, Jonathan M.; Arkin, Ronald C.

    1992-02-01

    As mobile robots are used in more uncertain and dangerous environments, it will become important to design them so that they can survive falls. In this paper, we examine a number of mechanisms and strategies that animals use to withstand these potentially catastrophic events and extend them to the design of robots. A brief survey of several aspects of how common cats survive falls provides an understanding of the issues involved in preventing traumatic injury during a falling event. After outlining situations in which robots might fall, a number of factors affecting their survival are described. From this background, several robot design guidelines are derived. These include recommendations for the physical structure of the robot as well as requirements for the robot control architecture. A control architecture is proposed based on reactive control techniques and action-oriented perception that is geared to support this form of survival behavior.

  18. Survival of falling robots

    NASA Technical Reports Server (NTRS)

    Cameron, Jonathan M.; Arkin, Ronald C.

    1992-01-01

    As mobile robots are used in more uncertain and dangerous environments, it will become important to design them so that they can survive falls. In this paper, we examine a number of mechanisms and strategies that animals use to withstand these potentially catastrophic events and extend them to the design of robots. A brief survey of several aspects of how common cats survive falls provides an understanding of the issues involved in preventing traumatic injury during a falling event. After outlining situations in which robots might fall, a number of factors affecting their survival are described. From this background, several robot design guidelines are derived. These include recommendations for the physical structure of the robot as well as requirements for the robot control architecture. A control architecture is proposed based on reactive control techniques and action-oriented perception that is geared to support this form of survival behavior.

  19. Some influences of rock strength and strain rate on propagation of rock avalanches

    NASA Astrophysics Data System (ADS)

    Bowman, Elisabeth; Rait, Kim

    2016-04-01

    Rock avalanches are extreme and destructive mass movements in which large volumes of rock (typically >1 million cubic metres) travel at high speeds, covering large distances, and the occurrence of which is highly unpredictable. The "size effect" in rock avalanches, whereby those with larger volumes produce greater spreading efficiency (as defined by an increase in normalised runout) or lower farboschung angle (defined as the tangent of the ratio of fall height to runout length), is well known. Studies have shown that rock strength is a controlling factor in the mobility of rock avalanches - that is, mass movements involving lower strength rock are generally found to produce greater mobility as evidenced by the spread of deposits or low farboschung angle. However, there are conflicting ideas as to how and why this influence is manifested. This paper discusses different theories of rock comminution in light of numerical simulations of rock clasts undergoing normal and shear induced loading, experimental work on rock avalanche behaviour, and dynamic fracture mechanics. In doing so, we introduce the idea of thresholds of strain rate for the production of dynamic fragmentation (as opposed to pseudo-static clast crushing) that are based, inter alia, on static rock strength. To do this, we refer to data from physical models using rock analogue materials, field data on chalk cliff collapses, and field statistics from documented rock avalanches. The roles of normal and shear loading and loading rate within a rock avalanche are examined numerically using 3D Discrete Element Method models of rock clasts loaded to failure. Results may help to reconcile the observations that large rock avalanches in stronger materials tend not to fragment as much as those in weaker materials and also possess lower mobility, while small cliff collapses (typically > 1000 cubic metres) in weak chalk can exhibit rock avalanche-like behaviour at much smaller volumes.

  20. Sphene (Titanite) as Both Monitor and Driver of Evolution of Felsic Magma: Miocene Volcanic Plutonic and Rocks of the Colorado River Region, NV-AZ, USA

    NASA Astrophysics Data System (ADS)

    Miller, C. F.; Colombini, L. L.; Wooden, J. L.; Mazdab, F. K.; Gualda, G. A.; Claiborne, L. E.; Ayers, J. C.

    2009-05-01

    Sphene is commonly the most abundant accessory mineral in metaluminous to weakly peraluminous igneous rocks. Its relatively large crystals preserve a wide array of zoning patterns and inclusions - notably, abundant other accessories and melt inclusions - and it is a major host for REE, U, Th, and HFSE. Thus it is a valuable repository of information about the history of the magmas from which it forms. Recent development of a Zr-in- sphene thermometer (Hayden et al CMP 155:529 2008) and of sensitive and precise in situ trace element analysis by SHRIMP-RG (Mazdab et al GSA abst 39:6:406 2007) permit more powerful exploitation of this repository. We have initiated a study of sphene in Miocene intrusive and extrusive rocks of the Colorado River extensional corridor for which extensive field, geochemical, and geochronological data provide context. Sphene is present as a late interstitial phase in some gabbros and diorites and common in quartz monzonites and granites. Among extrusive rocks, it occurs as phenocrysts in rhyolite lavas and tuffs that are products of small to giant eruptions (Peach Spring Tuff, >600 km3). Glasses that host sphene in the rhyolites are highly evolved (>76 wt% SiO2). Applying the Zr-in-sphene thermometer (TZr), SHRIMP-RG analyses indicate crystallization T between 730 and 810 C in both plutonic and volcanic rocks. This range is narrower than T estimates for zircon growth (Ti thermometry) for the same suite, which extend to somewhat lower and considerably higher values; zircons also tend to record more events and, evidently, longer histories. Ranges of REE patterns are variable and to some extent sample-specific, but all reveal common characteristics: (1) extremely high concentrations, especially for middle REE (maximum Sm in interiors 10-40x103 x chondrite); (2) deep negative Eu anomalies (Eu/Eu* ca. 0.1-0.2); (3) TZr and REE dropping toward rims - especially pronounced for MREE. Estimated Kds for REE from sphene rims and rhyolite glass or

  1. 2. View of Potomac River at Great Falls looking upstream ...

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

    2. View of Potomac River at Great Falls looking upstream from Observation Tower. The majestic character of this wild and untrammeled spot is vividly shown. Scanty flow is evidenced by light colored normal water line markings on rock formation. Washington Agueduct Dam is shown in upper portion. Maryland on right and Virginia on left. Natives quoted as saying the water was as low or lower than during the drought conditions of 1930. Mr. Horyduzak, Photographer, 1943. - Potowmack Company: Great Falls Canal & Locks, Great Falls, Fairfax County, VA

  2. A novel wearable smart button system for fall detection

    NASA Astrophysics Data System (ADS)

    Zhuang, Wei; Sun, Xiang; Zhi, Yueyan; Han, Yue; Mao, Hande

    2017-05-01

    Fall has been the second most cause of accidental injury to death in the world. It has been a serious threat to the physical and mental health of the elders. Therefore, developing wearable node system with fall detecting ability has become increasingly pressing at present. A novel smart button for long-term fall detection is proposed in this paper, which is able to accurately monitor the falling behavior, and sending warning message online as well. The smart button is based on the tri-axis acceleration sensor which is used to collect the body motion signals. By using the statistical metrics of acceleration characteristics, a new SVM classification algorithm with high positive accuracy and stability is proposed so as to classify the falls and activities of daily living, and the results can be real-time displayed on Android based mobile phone. The experiments show that our wearable node system can continuously monitor the falling behavior with positive rate 94.8%.

  3. Reading the Rocks. A Fall Activity Packet for Fifth Grade.

    ERIC Educational Resources Information Center

    Jackson Community Coll., MI. Dahlem Environmental Education Center.

    This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on various geological…

  4. Continuing Education: From Smooth Rock Falls to Opasatika

    ERIC Educational Resources Information Center

    Duhamel, Donald J.; And Others

    1976-01-01

    Describes a community education project in a sparsely settled area of Northern Ontario--its history and significant growth including the reasons why such growth occurred. Points out certain benefits that can accrue to the sponsoring agencies involved in community education and indicates in what directions the particular program which they have…

  5. Creep of porous rocks and measurements of elastic wave velocities under different hydrous conditions

    NASA Astrophysics Data System (ADS)

    Eslami, J.; Grgic, D.; Hoxha, D.

    2009-04-01

    The long-term mechanical behavior of rocks is of prime importance for many geological hazards (e.g., landslides, rock falls, and volcanoes) as well as for the stability of man-made structures (underground mines, road cuts, and open pits). In some shallow environments, rocks exist in partially saturated conditions which can evolve with time according to variations in the relative humidity hr of the atmosphere (e.g., natural slopes, open cut excavations). In underground mines, rocks are also partially saturated because of artificial ventilation. These variations in liquid saturation may have a large impact on mechanical behavior since they imply variations in capillary pressure and, depending on the porosity and on the shape of the porous network, variations in the effective stresses. Therefore, knowledge of static fatigue under saturated and partially saturated conditions is important for estimating the long-term stability of such rock structures. Many studies have already shown that time-dependent weakening is much more important for a saturated rock than for a dry one and that the time to failure may decrease by several orders of magnitude for saturated rocks as compared to dry rocks. In addition, the weakening effect of water is more significant in long-term experiments than in short-term ones (instantaneous loading). A physical explanation for these results may be the enhancement of subcritical crack growth by stress corrosion at crack tips which is often considered to be the main cause of time-dependent behavior of rocks. The failure of brittle rocks during compression tests is preceded by the formation, growth, and coalescence of microcracks. Elastic wave velocities are reduced due to the presence of open microcraks and fractures and may be used to monitor the progressive damage of rocks. The specific experimental setup available in our lab allows the simultaneous measurement of five velocities (with different polarizations and directions) and two directions

  6. Thermal Inertia of Rocks and Rock Populations

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

    2001-01-01

    The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

  7. Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    6 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows outcrops of sedimentary rocks in a crater located just north of the Sinus Meridiani region. Perhaps the crater was once the site of a martian lake.

    Location near: 2.9oN, 359.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  8. [Fear of falling].

    PubMed

    Alcalde Tirado, Pablo

    2010-01-01

    Fear of falling (FF) can be considered as a protective response to a real threat, preventing the elderly from performing activities with high risk of falling, but can also lead to a restriction of the activities that will result in a long-term adverse effect on social, physical or cognitive functions. There is a prevalence of FF in 30% in the elderly who have no history of falls, and double that in those with a history of falling. Its prevalence is increased in women and with advanced age. Several scales have been developed to measure the psychological effects of FF, among which are noted are, the Fall Efficacy Scale (FES), the Activities-specific Balance and Confidence Scale (ABC), and the survey of activities and fear of falling in the elderly (SAFE). It has negative consequences in the functionality, the subjective feeling of well-being, and in the consequent loss of independence. The functional and physical deterioration, or the quality of life is clearly related to the FF, although it has not been established if these factors are cause or effect. Multiple interventions have been recommended, bringing about changes that reinforce their confidence to carry out activities. Interventions and research should promote a realistic and appropriate approach to the risk of falls and teach the elderly to perform activities safely. The reduction in FF is an important goal in itself to improve the subjective feeling of well-being, and the benefits could be increased if this reduction was also accompanied by an increase in safe behaviour, social participation, and activities of the daily life.

  9. Rock mechanics. Second edition

    SciTech Connect

    Jumikis, A.R.

    1983-01-01

    Rock Mechanics, 2nd Edition deals with rock as an engineering construction material-a material with which, upon which, and within which civil engineers build structures. It thus pertains to hydraulic structures engineering; to highway, railway, canal, foundation, and tunnel engineering; and to all kinds of rock earthworks and to substructures in rock. Major changes in this new edition include: rock classification, rock types and description, rock testing equipment, rock properties, stability effects of discontinuity and gouge, grouting, gunite and shotcrete, and Lugeon's water test. This new edition also covers rock bolting and prestressing, pressure-grouted soil anchors, and rock slope stabilization.

  10. Rock Driller

    NASA Technical Reports Server (NTRS)

    Peterson, Thomas M.

    2001-01-01

    The next series of planetary exploration missions require a method of extracting rock and soil core samples. Therefore a prototype ultrasonic core driller (UTCD) was developed to meet the constraints of Small Bodies Exploration and Mars Sample Return Missions. The constraints in the design are size, weight, power, and axial loading. The ultrasonic transducer requires a relatively low axial load, which is one of the reasons this technology was chosen. The ultrasonic generator breadboard section can be contained within the 5x5x3 limits and weighs less than two pounds. Based on results attained the objectives for the first phase were achieved. A number of transducer probes were made and tested. One version only drills, and the other will actually provide a small core from a rock. Because of a more efficient transducer/probe, it will run at very low power (less than 5 Watts) and still drill/core. The prototype generator was built to allow for variation of all the performance-effecting elements of the transducer/probe/end effector, i.e., pulse, duty cycle, frequency, etc. The heart of the circuitry is what will be converted to a surface mounted board for the next phase, after all the parameters have been optimized and the microprocessor feedback can be installed.

  11. Occurrence of uranium-bearing coal, carbonaceous shale, and carbonaceous limestone in the Fall Creek area, Bonneville County, Idaho

    USGS Publications Warehouse

    Vine, James D.; Moore, George W.

    1952-01-01

    Uraniferous coal, carbonaceous shale, and carbonaceous limestone occur in the Bear River formation of Upper Crestaceous age at the Fall Creek prospect, in the Fall Creek area, Bonneville County, IDaho. The uranium compounds are believed to have been derived from mildly radioactive silicic volcanic rocks of the Tertiary age that rest unconformably on all older rocks and once overlay the Bear River formation and its coal. Meteoric water, percolating downward through the silicic volcanic rocks and into the older rocks along joints and faults, is believed to have brought the uranium compounds into contact with the coal and carbonaceous rocks in which the uranium was absorbed.

  12. Thumbsucking and falling asleep.

    PubMed

    Ozturk, M; Ozturk, O M

    1977-03-01

    A review of the studies on the aetiology of habitual thumbsucking reveals either contradictory or inconclusive results. In this study carried out in Turkey, 50 thumbsuckers, 50 non-thumbsuckers, 250 school children and 312 'problem' children were investigated through interviews, questionnaires and other clinical techniques with their mothers. Among variables studied were aspects of feeding, onset and incidence of thumbsucking, strength of sucking drive, sex distribution, educational level and occupation of mothers, parental attitudes toward physical contact with children, mother-child relationships, and particular forms of falling asleep. It was found that thumbsucking was aetiologically more related to ways of falling asleep than to other factors. An attempt was made to explain the social, psychological and physiological basis of the aetiological significance of the falling asleep-stage in habitual thumbsucking. These findings now permit predictive longitudinal investigations to test this accuracy.

  13. Raining Rocks

    NASA Image and Video Library

    2017-02-01

    Impact ejecta is material that is thrown up and out of the surface of a planet as a result of the impact of an meteorite, asteroid or comet. The material that was originally beneath the surface of the planet then rains down onto the environs of the newly formed impact crater. Some of this material is deposited close to the crater, folding over itself to form the crater rim, visible here as a yellowish ring. Other material is ejected faster and falls down further from the crater rim creating two types of ejecta: a "continuous ejecta blanket" and "discontinuous ejecta." Both are shown in this image. The blocky area at the center of the image close to the yellowish crater rim is the "continuous" ejecta. The discontinuous ejecta is further from the crater rim, streaking away from the crater like spokes on a bicycle. (Note: North is to the right.) http://photojournal.jpl.nasa.gov/catalog/PIA11180

  14. 52. VIEW SHOWING SITE OF ARIZONA FALL POWER PLANT, LOOKING ...

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

    52. VIEW SHOWING SITE OF ARIZONA FALL POWER PLANT, LOOKING EAST. CURRENT LOCATION OF THE REAL-TIME WATER QUALITY MONITORING STATION Photographer: James Eastwood, July 1990 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ

  15. 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

  16. FHR Iowa Falls Approval

    EPA Pesticide Factsheets

    This October 22, 2015, letter from EPA approves the petition from Flint Hills Resources, LLC, regarding non-grandfathered ethanol produced through the FHR Iowa Falls Process, qualifying under the Clean Air Act for renewable fuel (D-code 6) RINs under the R

  17. Fall 1984 Retention Study.

    ERIC Educational Resources Information Center

    Peralta Community Coll. District, Oakland, CA. Office of Research, Planning and Development.

    A study was conducted of the retention patterns of students enrolled in the Peralta Community College District (PCCD) in fall 1984 using college reports on withdrawals and grade distributions. The study focused on successful retention (i.e., all students who received a passing grade) and on total retention (i.e., all students who received any…

  18. Freshmen Survey. Fall 1985.

    ERIC Educational Resources Information Center

    Goodyear, Don

    In 1985, College of the Sequoias (COS) was asked by the Cooperative Institutional Research Program (conducted jointly by the American Council on Education and the University of California, Los Angeles) to participate in a survey of incoming freshmen for the fall 1985 semester. During the summer counseling session, 259 new COS freshmen were…

  19. Fall Protection in Construction

    DTIC Science & Technology

    1998-01-01

    Fall Protection in Construction U.S. Department of Labor Occupational Safety and Health Administration OSHA 3146 1998(Revised) Report Documentation...Department of Labor Occupational Safety & Health Administration 200 Constitution Avenue Washington, DC 20210 Performing Organization Report Number OSHA 3146...compliance responsibili- ties, which are set forth in OSHA standards themselves, and the Occupational Safety and Health Act. Moreover, because

  20. The News, Fall 2002.

    ERIC Educational Resources Information Center

    Giles, Ray, Ed.

    2002-01-01

    This fall 2002 newsletter from the Community College League of California contains several articles, news stories, and the brochure from the 2002 Annual Convention, "Celebrating the Way California LEARNS." Articles include: (1) "Nursing Shortage Poses Dilemma for Colleges: Access vs. Efficiency," a discussion of the debate over…

  1. Editors' Fall Picks

    ERIC Educational Resources Information Center

    Heilbrun, Margaret; McCormack, Heather; Katterjohn, Anna; Kuzyk, Raya; Roncevic, Mirela; Fox, Bette-Lee; Hoffert, Barbara

    2009-01-01

    "Library Journal's" review editors select fall titles readers won't want to miss--"Waiting on a Train: The Embattled Future of Passenger Rail Service" (James McCommons); "Happy" (Alex Lemon); "Free for All: Joe Papp, the Public, and the Greatest Theater Story Ever Told" (Kenneth Turan & Joseph Papp); "In My Father's Shadow: A Daughter Remembers…

  2. Fall 2005 Enrollment Report

    ERIC Educational Resources Information Center

    West Virginia Higher Education Policy Commission, 2005

    2005-01-01

    This annual report includes the following information presented in tabular form: (1) Location of West Virginia Public Institutions of Higher Education; (2) Location of West Virginia Independent Institutions of Higher Education; (3) Freshmen Headcount Enrollment, by Attendance Status, Early Fall 2005; (4) Headcount Enrollment by Residence,…

  3. Falling into Winter.

    ERIC Educational Resources Information Center

    Harrington, Carolyn Lang

    2000-01-01

    Presents an activity that connects art, science, and nature in which elementary school students learn about deciduous trees. Explains that students create a torn-tissue collage, using fall colors for a background and drawing a silhouette of a tree without leaves on top of the background with black crayon. (CMK)

  4. Editors' Fall Picks

    ERIC Educational Resources Information Center

    Heilbrun, Margaret; McCormack, Heather; Katterjohn, Anna; Kuzyk, Raya; Roncevic, Mirela; Fox, Bette-Lee; Hoffert, Barbara

    2009-01-01

    "Library Journal's" review editors select fall titles readers won't want to miss--"Waiting on a Train: The Embattled Future of Passenger Rail Service" (James McCommons); "Happy" (Alex Lemon); "Free for All: Joe Papp, the Public, and the Greatest Theater Story Ever Told" (Kenneth Turan & Joseph Papp); "In My Father's Shadow: A Daughter Remembers…

  5. Fall 2013 International Comparisons

    ERIC Educational Resources Information Center

    Northwest Evaluation Association, 2014

    2014-01-01

    This Fall report is an aggregated statistical analysis of Measures of Academic Progress® (MAP®) data from international schools. The report provides a consistent means of comparisons of specific sub-groups by subject and grade, which allows partners to compare their MAP® results with other schools within their region or membership organization.…

  6. Women's perspectives on falls and fall prevention during pregnancy.

    PubMed

    Brewin, Dorothy; Naninni, Angela

    2014-01-01

    Falls are the leading cause of unintentional injury in women. During pregnancy, even a minor fall can result in adverse consequences. Evidence to inform effective and developmentally appropriate pregnancy fall prevention programs is lacking. Early research on pregnancy fall prevention suggests that exercise may reduce falls. However, acceptability and effectiveness of pregnancy fall prevention programs are untested. To better understand postpartum women's perspective and preferences on fall prevention strategies during pregnancy to formulate an intervention. Focus groups and individual interviews were conducted with 31 postpartum women using descriptive qualitative methodology. Discussion of falls during pregnancy and fall prevention strategies was guided by a focus group protocol and enhanced by 1- to 3-minute videos on proposed interventions. Focus groups were audio recorded, transcribed, and analyzed using NVivo 10 software. Emerging themes were environmental circumstances and physical changes of pregnancy leading to a fall, prevention strategies, barriers, safety concerns, and marketing a fall prevention program. Wet surfaces and inappropriate footwear commonly contributed to falls. Women preferred direct provider counseling and programs including yoga and Pilates. Fall prevention strategies tailored to pregnant women are needed. Perspectives of postpartum women support fall prevention through provider counseling and individual or supervised exercise programs.

  7. Rheology of rock glaciers: a preliminary assessment

    SciTech Connect

    Giardino, J.R.; Vitek, J.D.; Hoskins, E.R.

    1985-01-01

    Movement of rock debris under the influence of gravity, i.e., mass movement, generates a range of phenomena from soil creep, through solifluction,debris flows and rock glaciers to rock falls. Whereas the resultant forms of these phenomena are different, common elements in the mechanics of movement are utilized in the basic interpretation of the processes of formation. Measurements of morphologic variables provide data for deductive analyses of processes that operate too slowly to observe or for processes that generated relict phenomena. External and internal characteristics or rock glacier morphometry and measured rates of motion serve as the basis for the development of a rheological model to explain phenomena classified as rock glaciers. A rock glacier in the Sangre de Cristo Mountains of Southern Colorado, which exhibits a large number of ridges and furrows and lichen bare fronts of lobes, suggests present day movement. A strain-net established on the surface provides evidence of movement characteristics. These data plus morphologic and fabric data suggest two rheological models to explain the flow of this rock glacier. Model one is based upon perfect plastic flow and model two is based upon stratified fluid movement with viscosity changing with depth. These models permit a better understanding of the movement mechanics and demonstrate that catastrophic events and slow creep contribute to the morphologic characteristics of this rock glacier.

  8. Development of a Wearable-Sensor-Based Fall Detection System

    PubMed Central

    Zhao, Hengyang; Zhao, Yan; Zhong, Haibo

    2015-01-01

    Fall detection is a major challenge in the public healthcare domain, especially for the elderly as the decline of their physical fitness, and timely and reliable surveillance is necessary to mitigate the negative effects of falls. This paper develops a novel fall detection system based on a wearable device. The system monitors the movements of human body, recognizes a fall from normal daily activities by an effective quaternion algorithm, and automatically sends request for help to the caregivers with the patient's location. PMID:25784933

  9. 30 CFR 75.202 - Protection from falls of roof, face and ribs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or... roof, face or ribs and coal or rock bursts. (b) No person shall work or travel under unsupported roof...

  10. 30 CFR 75.202 - Protection from falls of roof, face and ribs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or... roof, face or ribs and coal or rock bursts. (b) No person shall work or travel under unsupported roof...

  11. 30 CFR 75.202 - Protection from falls of roof, face and ribs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or... roof, face or ribs and coal or rock bursts. (b) No person shall work or travel under unsupported roof...

  12. 30 CFR 75.202 - Protection from falls of roof, face and ribs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or... roof, face or ribs and coal or rock bursts. (b) No person shall work or travel under unsupported roof...

  13. A Rock Encyclopedia That Includes Rock Samples.

    ERIC Educational Resources Information Center

    Laznicka, Peter

    1981-01-01

    Described is a rock encyclopedia combining rock sample sets and encyclopedic word and picture entries which can be used as a realistic information resource for independent study or as a part of a course. (JT)

  14. Rock expansion caused by ultrasound

    NASA Astrophysics Data System (ADS)

    Hedberg, C.; Gray, A.

    2013-12-01

    It has during many years been reported that materials' elastic modulus decrease when exposed to influences like mechanical impacts, ultrasound, magnetic fields, electricity and even humidity. Non-perfect atomic structures like rocks, concrete, or damaged metals exhibit a larger effect. This softening has most often been recorded by wave resonance measurements. The motion towards equilibrium is slow - often taking hours or days, which is why the effect is called Slow Dynamics [1]. The question had been raised, if a material expansion also occurs. 'The most fundamental parameter to consider is the volume expansion predicted to occur when positive hole charge carriers become activated, causing a decrease of the electron density in the O2- sublattice of the rock-forming minerals. This decrease of electron density should affect essentially all physical parameters, including the volume.' [2]. A new type of configuration has measured expansion of a rock subjected to ultrasound. A PZT was used as a pressure sensor while the combined thickness of the rock sample and the PZT sensor was held fixed. The expansion increased the stress in both the rock and the PZT, which gave an out-put voltage from the PZT. Knowing its material properties then made it possible to calculate the rock expansion. The equivalent strain caused by the ultrasound was approximately 3 x 10-5. The temperature was monitored and accounted for during the tests and for the maximum expansion the increase was 0.7 C, which means the expansion is at least to some degree caused by heating of the material by the ultrasound. The fraction of bonds activated by ultrasound was estimated to be around 10-5. References: [1] Guyer, R.A., Johnson, P.A.: Nonlinear Mesoscopic Elasticity: The Complex Behaviour of Rocks, Soils, Concrete. Wiley-VCH 2009 [2] M.M. Freund, F.F. Freund, Manipulating the Toughness of Rocks through Electric Potentials, Final Report CIF 2011 Award NNX11AJ84A, NAS Ames 2012.

  15. Improving the Monitoring, Verification, and Accounting of CO{sub 2} Sequestered in Geologic Systems with Multicomponent Seismic Technology and Rock Physics Modeling

    SciTech Connect

    Alkan, Engin; DeAngelo, Michael; Hardage, Bob; Sava, Diana; Sullivan, Charlotte; Wagner, Donald

    2012-12-31

    Research done in this study showed that P-SV seismic data provide better spatial resolution of geologic targets at our Appalachian Basin study area than do P-P data. This finding is important because the latter data (P-P) are the principal seismic data used to evaluate rock systems considered for CO{sub 2} sequestration. The increase in P-SV{sub 1} resolution over P-P resolution was particularly significant, with P-SV{sub 1} wavelengths being approximately 40-percent shorter than P-P wavelengths. CO{sub 2} sequestration projects across the Appalachian Basin should take advantage of the increased resolution provided by converted-shear seismic modes relative to P-wave seismic data. In addition to S-wave data providing better resolution of geologic targets, we found S-wave images described reservoir heterogeneities that P-P data could not see. Specifically, a channel-like anomaly was imaged in a key porous sandstone interval by P-SV{sub 1} data, and no indication of the feature existed in P-P data. If any stratigraphic unit is considered for CO{sub 2} storage purposes, it is important to know all heterogeneities internal to the unit to understand reservoir compartmentalization. We conclude it is essential that multicomponent seismic data be used to evaluate all potential reservoir targets whenever a CO{sub 2} storage effort is considered, particularly when sequestration efforts are initiated in the Appalachian Basin. Significant differences were observed between P-wave sequences and S- wave sequences in data windows corresponding to the Oriskany Sandstone, a popular unit considered for CO{sub 2} sequestration. This example demonstrates that S-wave sequences and facies often differ from P-wave sequences and facies and is a principle we have observed in every multicomponent seismic interpretation our research laboratory has done. As a result, we now emphasis elastic wavefield seismic stratigraphy in our reservoir characterization studies, which is a science based on the

  16. Development of Fall Detection System Using Ultrasound Sensors

    NASA Astrophysics Data System (ADS)

    Tajima, Takuya; Abe, Takehiko; Kimura, Haruhiko

    This paper proposes a sensing system for detecting bather's fall. The fall detection system uses ultrasound sensors installed on the ceiling of bathroom to measure the distance between sensor and a bather. The merits of utilizing ultrasound sensor are easy installation and easy use. Moreover the apparatus has an advantage of enhancing the privacy of bathers and having robustness against humidity. In order to detect bather's fall, the proposed system uses the following two methods: status detection and behavior detection. The function of status detection is to estimate bather's postures such as standing and sitting by monitoring the highest part of bather's body. Meanwhile, the function of behavior detection is to grasp the speed of bather's vertical movement by monitoring the change of distance between sensor and the bather. The system estimates the occurrence of bather's fall when the distance changes suddenly. As a result of experiment with some subjects, the system was possible to detect bather's falling behavior with high accuracy.

  17. Lunar Rocks

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The second manned lunar landing mission, Apollo 12 launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn V launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what's known as the Ocean of Storms while astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples, some of which can be seen in this photograph. Apollo 12 safely returned to Earth on November 24, 1969.

  18. Novel Hierarchical Fall Detection Algorithm Using a Multiphase Fall Model

    PubMed Central

    Hsieh, Chia-Yeh; Liu, Kai-Chun; Huang, Chih-Ning; Chu, Woei-Chyn; Chan, Chia-Tai

    2017-01-01

    Falls are the primary cause of accidents for the elderly in the living environment. Reducing hazards in the living environment and performing exercises for training balance and muscles are the common strategies for fall prevention. However, falls cannot be avoided completely; fall detection provides an alarm that can decrease injuries or death caused by the lack of rescue. The automatic fall detection system has opportunities to provide real-time emergency alarms for improving the safety and quality of home healthcare services. Two common technical challenges are also tackled in order to provide a reliable fall detection algorithm, including variability and ambiguity. We propose a novel hierarchical fall detection algorithm involving threshold-based and knowledge-based approaches to detect a fall event. The threshold-based approach efficiently supports the detection and identification of fall events from continuous sensor data. A multiphase fall model is utilized, including free fall, impact, and rest phases for the knowledge-based approach, which identifies fall events and has the potential to deal with the aforementioned technical challenges of a fall detection system. Seven kinds of falls and seven types of daily activities arranged in an experiment are used to explore the performance of the proposed fall detection algorithm. The overall performances of the sensitivity, specificity, precision, and accuracy using a knowledge-based algorithm are 99.79%, 98.74%, 99.05% and 99.33%, respectively. The results show that the proposed novel hierarchical fall detection algorithm can cope with the variability and ambiguity of the technical challenges and fulfill the reliability, adaptability, and flexibility requirements of an automatic fall detection system with respect to the individual differences. PMID:28208694

  19. Novel Hierarchical Fall Detection Algorithm Using a Multiphase Fall Model.

    PubMed

    Hsieh, Chia-Yeh; Liu, Kai-Chun; Huang, Chih-Ning; Chu, Woei-Chyn; Chan, Chia-Tai

    2017-02-08

    Falls are the primary cause of accidents for the elderly in the living environment. Reducing hazards in the living environment and performing exercises for training balance and muscles are the common strategies for fall prevention. However, falls cannot be avoided completely; fall detection provides an alarm that can decrease injuries or death caused by the lack of rescue. The automatic fall detection system has opportunities to provide real-time emergency alarms for improving the safety and quality of home healthcare services. Two common technical challenges are also tackled in order to provide a reliable fall detection algorithm, including variability and ambiguity. We propose a novel hierarchical fall detection algorithm involving threshold-based and knowledge-based approaches to detect a fall event. The threshold-based approach efficiently supports the detection and identification of fall events from continuous sensor data. A multiphase fall model is utilized, including free fall, impact, and rest phases for the knowledge-based approach, which identifies fall events and has the potential to deal with the aforementioned technical challenges of a fall detection system. Seven kinds of falls and seven types of daily activities arranged in an experiment are used to explore the performance of the proposed fall detection algorithm. The overall performances of the sensitivity, specificity, precision, and accuracy using a knowledge-based algorithm are 99.79%, 98.74%, 99.05% and 99.33%, respectively. The results show that the proposed novel hierarchical fall detection algorithm can cope with the variability and ambiguity of the technical challenges and fulfill the reliability, adaptability, and flexibility requirements of an automatic fall detection system with respect to the individual differences.

  20. Weathering damage evaluation of rock properties in the Bunhwangsa temple stone pagoda, Gyeongju, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Lee, Chan Hee; Yi, Jeong Eun

    2007-06-01

    The stone pagoda of the Bunhwangsa temple in Republic of Korea was made of piling small brick-shaped stones. The majority of stone bricks are andesitic rocks with variable geneses. Rock properties of the pagoda roof suffer partial significant deterioration, such as multiple peel-offs, exfoliation, onion-peel-like decomposition, cracks forming round lines and falling-off stone pieces. The stylobates and tabernacles at the four corners are composed of granitic rocks, which are heavily contaminated by lichens and mosses. Some of these contamination marks show dark black or yellowish brown colors by inorganic secondary hydrates. The four tabernacles and northern face of the pagoda body have been exposed to relatively high humidity, which causes light gray efflorescence as stalactites between the northern and western sides of the body. The efflorescences are composed of calcite, gypsum and clay minerals. The stone lion statues at the southeast and northeast corners are made of alkali granite, while the others are lithic tuff. Total rock properties of the pagoda consist of 9,708 stone bricks. Among them, 11.0% are fractured, 6.7% are fallen off, and 7.0% show considerable surface efflorescence, which shows that the pagoda has been highly deteriorated by physical, chemical and biological weathering. The authors strongly suggest long-term monitoring and comprehensive conservation researches.

  1. Falling film evaporator

    DOEpatents

    Bruns, Lester E.

    1976-01-01

    A falling film evaporator including a vertically oriented pipe heated exteriorly by a steam jacket and interiorly by a finned steam tube, all heating surfaces of the pipe and steam tube being formed of a material wet by water such as stainless steel, and packing within the pipe consisting of Raschig rings formed of a material that is not wet by water such as polyvinylidene fluoride.

  2. The Resource. Fall 2001

    DTIC Science & Technology

    2001-01-01

    Adams, Director of Scientific Visualization, initiated a Bring Your Own Data ( BYOD ) workshop for MSRC users. The first workshop was held June 25-26 in...leverage these assets in their future work. The first BYOD workshop was definitely a benefit to the users. Chris Stone, in particular was able to...publications 28 ERDC MSRC The Resource, Fall 2001 ac ro ny m s AG Access Grid AMR Adaptive Mesh Refinement BYOD Bring Your Own Data CDC Control Data

  3. Design Support of an Above Cap-rock Early Detection Monitoring System using Simulated Leakage Scenarios at the FutureGen2.0 Site

    SciTech Connect

    Williams, Mark D.; USA, Richland Washington; Vermuel, Vince R.; USA, Richland Washington; Oostrom, Mart; USA, Richland Washington; Porse, Sean L.; USA, Richland Washington; Thorne, Paul D.; USA, Richland Washington; Szecsody, Jim E.; USA, Richland Washington; Horner, Jake A.; USA, Richland Washington; Gilmore, Tyler J.; USA, Richland Washington

    2014-12-31

    The FutureGen 2.0 Project will design and build a first-of-its-kind, near-zero emissions coal-fueled power plant with carbon capture and storage (CCS). To assess storage site performance and meet the regulatory requirements of the Class VI Underground Injection Control (UIC) Program for CO2 Geologic Sequestration, the FutureGen 2.0 project will implement a suite of monitoring technologies designed to evaluate CO2 mass balance and detect any unforeseen loss in CO2 containment. The monitoring program will include direct monitoring of the reservoir, and early-leak-detection monitoring directly above the primary confining zone. This preliminary modeling study described here focuses on hypothetical leakage scenarios into the first permeable unit above the primary confining zone (Ironton Sandstone) and is used to support assessment of early-leak detection capabilities. Future updates of the model will be used to assess potential impacts on the lowermost underground source of drinking water (Saint Peter Sandstone) for a range of theoretical leakage scenarios. This preliminary modeling evaluation considers both pressure response and geochemical signals in the overlying Ironton Sandstone. This model is independent of the FutureGen 2.0 reservoir model in that it does not simulate caprock discontinuities, faults, or failure scenarios. Instead this modeling effort is based on theoretical, volumetric-rate based leakage scenarios. The scenarios include leakage of 1% of the total injected CO2 mass, but spread out over different time periods (20, 100, and 500 years) with each case yielding a different mass flux (i.e., smaller mass fluxes for longer duration leakage cases]. A brine leakage scenario using a volumetric leakage similar to the 20 year 1% CO2 case was also considered. A framework for the comparison of the various cases was developed based on the exceedance of selected pressure and geochemical thresholds at different

  4. Post-Closure Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada (Rev. No.: 0, June 2002)

    SciTech Connect

    NNSA /NV

    2002-06-06

    There was an increase in total petroleum hydrocarbons (TPH) concentrations at all three depths within Borehole DRA-0. The oxygen concentration at 40 ft below ground surface (bgs) decreased. There was also an increase in carbon dioxide concentration at that depth. The decrease in oxygen concentrations and the increase in carbon dioxide concentration at the 40 ft bgs level could be possible indicators of natural attenuation. It is not possible to determine trends or biodegradation rates with the limited amount of data collected from the site. The sample results from this first monitoring period did not correlate with the baseline results collected in August 2000. Additional samples will be collected and the results will be compared to previously collected samples to determine if the site was at equilibrium in August 2000. Continued annual monitoring will be conducted as specified in the Closure Report to determine trends at the site. As natural attenuation occurs, the TPH concentrations should decrease. The TPH concentrations will be compared over successive monitoring events to determine trends and approximate rates. As natural attenuation occurs, oxygen will be consumed and carbon dioxide will be produced. The oxygen, nitrogen, and carbon dioxide concentrations will also be evaluated to determine if biodegradation is indicated. When all available oxygen has been consumed, methane-producing bacteria may continue the natural attenuation process so methane levels will be monitored as an additional possible indicator of natural attenuation. The rate of decrease will be determined on the microbial populations, contaminant concentrations, available nutrients, and other environmental factors. Samples were collected and submitted for microbial analysis during closure activities. The results indicated that the microbial populations and nutrients were adequate for limited bioremediation (DOE/NV, 2000). Additional sampling for microbial analysis are not planned. The site is

  5. Design Support of an Above Cap-rock Early Detection Monitoring System using Simulated Leakage Scenarios at the FutureGen2.0 Site

    DOE PAGES

    Williams, Mark D.; USA, Richland Washington; Vermuel, Vince R.; ...

    2014-12-31

    The FutureGen 2.0 Project will design and build a first-of-its-kind, near-zero emissions coal-fueled power plant with carbon capture and storage (CCS). To assess storage site performance and meet the regulatory requirements of the Class VI Underground Injection Control (UIC) Program for CO2 Geologic Sequestration, the FutureGen 2.0 project will implement a suite of monitoring technologies designed to evaluate CO2 mass balance and detect any unforeseen loss in CO2 containment. The monitoring program will include direct monitoring of the reservoir, and early-leak-detection monitoring directly above the primary confining zone. This preliminary modeling study described here focuses on hypothetical leakage scenarios intomore » the first permeable unit above the primary confining zone (Ironton Sandstone) and is used to support assessment of early-leak detection capabilities. Future updates of the model will be used to assess potential impacts on the lowermost underground source of drinking water (Saint Peter Sandstone) for a range of theoretical leakage scenarios. This preliminary modeling evaluation considers both pressure response and geochemical signals in the overlying Ironton Sandstone. This model is independent of the FutureGen 2.0 reservoir model in that it does not simulate caprock discontinuities, faults, or failure scenarios. Instead this modeling effort is based on theoretical, volumetric-rate based leakage scenarios. The scenarios include leakage of 1% of the total injected CO2 mass, but spread out over different time periods (20, 100, and 500 years) with each case yielding a different mass flux (i.e., smaller mass fluxes for longer duration leakage cases]. A brine leakage scenario using a volumetric leakage similar to the 20 year 1% CO2 case was also considered. A framework for the comparison of the various cases was developed based on the exceedance of selected pressure and geochemical thresholds at different distances from the point of leakage and at

  6. Modeling a falling slinky

    NASA Astrophysics Data System (ADS)

    Cross, R. C.; Wheatland, M. S.

    2012-12-01

    A slinky is an example of a tension spring: in an unstretched state a slinky is collapsed, with turns touching, and a finite tension is required to separate the turns from this state. If a slinky is suspended from its top and stretched under gravity and then released, the bottom of the slinky does not begin to fall until the top section of the slinky, which collapses turn by turn from the top, collides with the bottom. The total collapse time tc (typically ˜0.3 s for real slinkies) corresponds to the time required for a wave front to propagate down the slinky to communicate the release of the top end. We present a modification to an existing model for a falling tension spring [Calkin, Am. J. Phys. 61, 261-264 (1993)] and apply it to data from filmed drops of two real slinkies. The modification of the model is the inclusion of a finite time for collapse of the turns of the slinky behind the collapse front propagating down the slinky during the fall. The new finite-collapse time model achieves a good qualitative fit to the observed positions of the top of the real slinkies during the measured drops. The spring constant k for each slinky is taken to be a free parameter in the model. The best-fit model values for k for each slinky are approximately consistent with values obtained from measured periods of oscillation of the slinkies.

  7. RadNet Air Data From Little Rock, AR

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Little Rock, AR from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  8. Comparison and characterization of Android-based fall detection systems.

    PubMed

    Luque, Rafael; Casilari, Eduardo; Morón, María-José; Redondo, Gema

    2014-10-08

    Falls are a foremost source of injuries and hospitalization for seniors. The adoption of automatic fall detection mechanisms can noticeably reduce the response time of the medical staff or caregivers when a fall takes place. Smartphones are being increasingly proposed as wearable, cost-effective and not-intrusive systems for fall detection. The exploitation of smartphones' potential (and in particular, the Android Operating System) can benefit from the wide implantation, the growing computational capabilities and the diversity of communication interfaces and embedded sensors of these personal devices. After revising the state-of-the-art on this matter, this study develops an experimental testbed to assess the performance of different fall detection algorithms that ground their decisions on the analysis of the inertial data registered by the accelerometer of the smartphone. Results obtained in a real testbed with diverse individuals indicate that the accuracy of the accelerometry-based techniques to identify the falls depends strongly on the fall pattern. The performed tests also show the difficulty to set detection acceleration thresholds that allow achieving a good trade-off between false negatives (falls that remain unnoticed) and false positives (conventional movements that are erroneously classified as falls). In any case, the study of the evolution of the battery drain reveals that the extra power consumption introduced by the Android monitoring applications cannot be neglected when evaluating the autonomy and even the viability of fall detection systems.

  9. Comparison and Characterization of Android-Based Fall Detection Systems

    PubMed Central

    Luque, Rafael; Casilari, Eduardo; Morón, María-José; Redondo, Gema

    2014-01-01

    Falls are a foremost source of injuries and hospitalization for seniors. The adoption of automatic fall detection mechanisms can noticeably reduce the response time of the medical staff or caregivers when a fall takes place. Smartphones are being increasingly proposed as wearable, cost-effective and not-intrusive systems for fall detection. The exploitation of smartphones' potential (and in particular, the Android Operating System) can benefit from the wide implantation, the growing computational capabilities and the diversity of communication interfaces and embedded sensors of these personal devices. After revising the state-of-the-art on this matter, this study develops an experimental testbed to assess the performance of different fall detection algorithms that ground their decisions on the analysis of the inertial data registered by the accelerometer of the smartphone. Results obtained in a real testbed with diverse individuals indicate that the accuracy of the accelerometry-based techniques to identify the falls depends strongly on the fall pattern. The performed tests also show the difficulty to set detection acceleration thresholds that allow achieving a good trade-off between false negatives (falls that remain unnoticed) and false positives (conventional movements that are erroneously classified as falls). In any case, the study of the evolution of the battery drain reveals that the extra power consumption introduced by the Android monitoring applications cannot be neglected when evaluating the autonomy and even the viability of fall detection systems. PMID:25299953

  10. Fall prevention walker during rehabilitation

    NASA Astrophysics Data System (ADS)

    Tee, Kian Sek; E, Chun Zhi; Saim, Hashim; Zakaria, Wan Nurshazwani Wan; Khialdin, Safinaz Binti Mohd; Isa, Hazlita; Awad, M. I.; Soon, Chin Fhong

    2017-09-01

    This paper proposes on the design of a walker for the prevention of falling among elderlies or patients during rehabilitation whenever they use a walker to assist them. Fall happens due to impaired balance or gait problem. The assistive device is designed by applying stability concept and an accelerometric fall detection system is included. The accelerometric fall detection system acts as an alerting device that acquires body accelerometric data and detect fall. Recorded accelerometric data could be useful for further assessment. Structural strength of the walker was verified via iterations of simulation using finite element analysis, before being fabricated. Experiments were conducted to identify the fall patterns using accelerometric data. The design process and detection of fall pattern demonstrates the design of a walker that could support the user without fail and alerts the helper, thus salvaging the users from injuries due to fall and unattended situation.

  11. Albeni Falls Wildlife Mitigation : Annual Report 2002.

    SciTech Connect

    Terra-Berns, Mary

    2003-01-01

    The Albeni Falls Interagency Work Group continued to actively engage in implementing wildlife mitigation actions in 2002. Regular Work Group meetings were held to discuss budget concerns affecting the Albeni Falls Wildlife Mitigation Program, to present potential acquisition projects, and to discuss and evaluate other issues affecting the Work Group and Project. Work Group members protected 1,386.29 acres of wildlife habitat in 2002. To date, the Albeni Falls project has protected approximately 5,914.31 acres of wildlife habitat. About 21% of the total wildlife habitat lost has been mitigated. Administrative activities have increased as more properties are purchased and continue to center on restoration, operation and maintenance, and monitoring. In 2001, Work Group members focused on development of a monitoring and evaluation program as well as completion of site-specific management plans. This year the Work Group began implementation of the monitoring and evaluation program performing population and plant surveys, data evaluation and storage, and map development as well as developing management plans. Assuming that the current BPA budget restrictions will be lifted in the near future, the Work Group expects to increase mitigation properties this coming year with several potential projects.

  12. Mechanisms of large rock avalanche propagation

    NASA Astrophysics Data System (ADS)

    Bowman, Elisabeth

    2014-05-01

    Large rock avalanches present a serious mountain hazard to lifelines, infrastructure and lives. They are one of a class of low frequency, high impact events for which there is a still considerable debate over the transport mechanism. The behaviour of large rock avalanches, sometimes referred to as sturzstrom or "stream flow" after Heim, is characterised by a volumetric dependence, so that very large rock avalanches tend to travel with a greater spreading "efficiency" than smaller ones. In this work we propose a mechanism for the volumetric dependence of rock avalanche spread (or runout) in light of the ubiquitous dynamic fragmentation behaviour of brittle solids, Terzaghi's principle of effective stress as used most commonly in soil mechanics, and concepts of momentum transfer. The proposed conceptual model is based on both observations of field scale events, such as made at Elm in Switzerland, Huascaran in Peru and Falling Mountain in New Zealand, and small scale physical model experiments using analogue rock materials which have been conducted at elevated g-level so as to increase stress levels within the experiments. In particular the model aims to explain how momentum transfer between elements within a fragmenting rock avalanche mass may lead to the greater mobility or spreading efficiency that is observed at large scale and may provide insight as to the conditions needed for rock avalanche propagation and arrest.

  13. Rollerjaw Rock Crusher

    NASA Technical Reports Server (NTRS)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  14. Annual Post-Closure Inspection and Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada, with Errata Sheet, Rev. No.: 1

    SciTech Connect

    Wickline, Alfred

    2007-01-01

    This report presents the data collected during field activities and quarterly soil-gas sampling activities conducted from May 9, 2005, through May 20, 2006, at Corrective Action Unit (CAU) 329, Area 22 Desert Rock Airstrip (DRA) Fuel Spill; Corrective Action Site (CAS) 22-44-01, Fuel Spill. The CAU is located at the DRA, which is located approximately two miles southwest of Mercury, Nevada. A risk evaluation was added to the scope of the project to determine if the residual concentration of the hazardous constituents of JP4 pose an unacceptable risk to human health or the environment and if a corrective action was required at the site, because the current quarterly monitoring program is not expected to yield a rate constant that could be used effectively to determine a biodegradation rate for total petroleum hydrocarbons (TPH) in less than the initial five years outlined in the CR. Additionally, remediation to the Tier 1 action level for TPH is not practical or technically feasible due to the depth of contamination. Field activities were conducted under the Addendum to the CR to collect sufficient data to determine the rate of biodegradation for TPH contamination at CAU 329 to support closure requirements. Reconstruction of the monitoring system at the site and quarterly soil-gas sampling were conducted to collect the required data. Because existing Wells DRA-0 and DRA-3 were determined to be insufficient to provide adequate data, soil-gas monitoring Wells DRA-10 and DRA-11 were installed. Two soil-gas sampling events were conducted to establish a baseline for the site, and subsequent quarterly sampling was conducted as part of the quarterly soil-gas sampling program. In addition, soil samples were collected during well drilling activities so comparisons might be made between the initial soil contamination levels in 2000 and the concentrations present at the time of the well installation.

  15. Long-distance free fall

    NASA Astrophysics Data System (ADS)

    Gallant, Joseph; Carlson, James

    1999-03-01

    We present an analysis of a situation described in Milton's epic poem "Paradise Lost" in which we calculate the distance required for a nine-day free-fall from rest to the Earth. The resulting method is completely general, and can be applied to free-fall toward other bodies and to near-Earth free-fall as well.

  16. A smart rock

    NASA Astrophysics Data System (ADS)

    Pressel, Phil

    2014-12-01

    This project was to design and build a protective weapon for a group of associations that believed in aliens and UFO's. They collected enough contributions from societies and individuals to be able to sponsor and totally fund the design, fabrication and testing of this equipment. The location of this facility is classified. It also eventually was redesigned by the Quartus Engineering Company for use at a major amusement park as a "shoot at targets facility." The challenge of this project was to design a "smart rock," namely an infrared bullet (the size of a gallon can of paint) that could be shot from the ground to intercept a UFO or any incoming suspicious item heading towards the earth. Some of the challenges to design this weapon were to feed cryogenic helium at 5 degrees Kelvin from an inair environment through a unique rotary coupling and air-vacuum seal while spinning the bullet at 1500 rpm and maintain its dynamic stability (wobble) about its spin axis to less than 10 micro-radians (2 arc seconds) while it operated in a vacuum. Precision optics monitored the dynamic motion of the "smart rock."

  17. Accelerated Weathering of Rocks.

    DTIC Science & Technology

    1977-08-01

    Dry tests en polished specimens with alternating heating and co- oling actions; ii) Wet tests in destilled water, with alternating...Rock-type Dry tests KxlO2 Wet tests KxlO2 Sound rock SR 3.64 8.31 Medium altered rock MAR 4.96 31.58 Very altered rock VAR 8.89 116.20 TABLE X...Sound rock SR Medium altered rock Very altered rock" KAR VAR ’ Reflectivity R (%) dry test wet test dry test wet test dry test wet

  18. [Fall risk and fracture. Aging and fall/fracture].

    PubMed

    Kozaki, Koichi

    2013-05-01

    Fall deteriorates QOL and ADL of elderly people, especially when they suffer from hip and vertebral fractures. It is not easy to identify the cause of falling, because falling usually result from multiple factors. Among various potential causes, osteoporosis, osteoarthritis, medication of hypnotic drugs, and environmental factors are important, because they are frequent and can be modifiable. When evaluating fall risks, grasping power, one-leg standing time, timed up&go test, are useful. On the other hand, fall risk index, 22-item self-assessment test, is easy and even better in predicting future falls. In the Cochrane systematic review article 2009, exercise such as Tai-Chi, withdrawal of hypnotic drugs, and vitamin D supplementation are shown to prevent falls in community-dwelling elderly.

  19. `In free fall'

    NASA Astrophysics Data System (ADS)

    Beijerinck, Herman C. W.

    2014-01-01

    Physicists in the lead of a fiction book or a play, that's a rare event! Writers in general do not understand physics, while physicists seldom have the talent of writing for a large audience. So when it happens, we should rejoice. The up-and-coming German author Juli Zeh [1] (1974), who studied law, has succeeded in combining beautiful prose, psychological drama, crime and physics in a challenging book `In free fall' [2]. A good friend of hers, Bettina Bruinier, has put the core message of the book into a compelling play in the `Volkstheater' in Munich [1]. Yes, it can be done.

  20. Water quality in the Anacostia River, Maryland and Rock Creek, Washington, D.C.: Continuous and discrete monitoring with simulations to estimate concentrations and yields of nutrients, suspended sediment, and bacteria

    USGS Publications Warehouse

    Miller, Cherie V.; Chanat, Jeffrey G.; Bell, Joseph M.

    2013-01-01

    Concentrations and loading estimates for nutrients, suspended sediment, and E. coli bacteria were summarized for three water-quality monitoring stations on the Anacostia River in Maryland and one station on Rock Creek in Washington, D.C. Both streams are tributaries to the Potomac River in the Washington, D.C. metropolitan area and contribute to the Chesapeake Bay estuary. Two stations on the Anacostia River, Northeast Branch at Riverdale, Maryland and Northwest Branch near Hyattsville, Maryland, have been monitored for water quality during the study period from 2003 to 2011 and are located near the shift from nontidal to tidal conditions near Bladensburg, Maryland. A station on Paint Branch is nested above the station on the Northeast Branch Anacostia River, and has slightly less developed land cover than the Northeast and Northwest Branch stations. The Rock Creek station is located in Rock Creek Park, but the land cover in the watershed surrounding the park is urbanized. Stepwise log-linear regression models were developed to estimate the concentrations of suspended sediment, total nitrogen, total phosphorus, and E. coli bacteria from continuous field monitors. Turbidity was the strongest predictor variable for all water-quality parameters. For bacteria, water temperature improved the models enough to be included as a second predictor variable due to the strong dependence of stream metabolism on temperature. Coefficients of determination (R2) for the models were highest for log concentrations of suspended sediment (0.9) and total phosphorus (0.8 to 0.9), followed by E. coli bacteria (0.75 to 0.8), and total nitrogen (0.6). Water-quality data provided baselines for conditions prior to accelerated implementation of multiple stormwater controls in the watersheds. Counties are currently in the process of enhancing stormwater controls in both watersheds. Annual yields were estimated for suspended sediment, total nitrogen, total phosphorus, and E. coli bacteria using

  1. [Can falls be prevented?].

    PubMed

    Dubousset, Jean

    2014-06-01

    Most recommendations and measures intended to prevent falls focus on the elderly (see HAS guideline of April 2009) but, in our opinion, this isfar too late: prevention must begin much earlier, not only by identifying persons at risk, but also by providing personalized lifestyle advice adapted to each individual's biomechanical, somatic, neurological and biological characteristics. The first preventive measure is to identify a possible deterioration of balance, starting with a physical examination at the age of 45 and repeated regularly throughout life. Extrinsic preventive measures focusing on the domestic and external environments are clearly necessary. But what is most important is to detect and, if necessary, correct any degradation of intrinsic (intracorporeal or somatic) factors starting at the age of 45 years; these include vision, vestibular function and balance, proprioception, and psychological and neurological status. Chronic illnesses and their treatments must also be taken into account: treatment must be limited to indispensable drugs; sedative psychotropics must be avoided if possible; and polymedication must be tightly controlled, as it is a major risk factor for falls. Prevention also requires a diet sufficiently rich in protein, calcium and vitamin D3 (to prevent osteoporosis), and regular daily exercise adapted to the individual, if possible associated with a simultaneous cognitive task. The last key point is the absolute need for thorough functional rehabilitation after any accidental or medical trauma, regardless of age, with the aim of restoring functional status to that existing prior to the accident.

  2. Retrospective analysis of fatal falls.

    PubMed

    Thierauf, Annette; Preuss, Johanna; Lignitz, Eberhard; Madea, Burkhard

    2010-05-20

    Fatal falls are frequent and inhomogeneous events and affect every age. The criminalistic classification can often only be done on the basis of extensive investigations and the autopsy results. We retrospectively surveyed 291 cases of fatal falls on which a post-mortem examination had been carried out in the institutes of Forensic Medicine in Bonn and Greifswald. In large part, these cases are falls from height (n=123) and ground-level falls (n=122). These are compared to fatal falls down a stairs (n=46); the analysis is confined to injuries to the cranium. In ground-level falls the injury pattern in falls under the influence of alcohol differs from that of falls with no alcohol in the case history: all injuries are seen in higher relative frequency in casualties after the consumption of alcohol. In falls from height, the previous consumption of alcohol did not influence the injury pattern; the intracranial traumas are seen in decreasing frequency with increasing heights. The aim of this retrospective analysis is to present injury patterns and influencing factors like fall heights and alcohol for the different kinds of falls on the basis of our collective and to demonstrate similarities and differences between the subgroups.

  3. Scattering from Rock and Rock Outcrops

    DTIC Science & Technology

    2014-09-30

    slope was determined from high-resolution interferometric bathymetry so that the global grazing angle of the 5 ideal mean seafloor could be mapped to...from exposed rock on the seafloor , (i.e., individual rocks and rock outcrops) presents some of the most difficult challenges for modern MCM and ASW...classification tools. Inverse models based on forward models would be essential for using sonar systems for remote sensing of seafloor properties. An

  4. Preventing falls with vitamin D.

    PubMed

    Shuler, Franklin D; Schlierf, Thomas; Wingate, Matthew

    2014-01-01

    Falls are the number one cause for injury-related morbidity and mortality in West Virginia's seniors. Multiple independent variables contribute to the risk of a fall: previous falls, alterations in balance and vision, impairments in gait and strength, and medications most highly correlate with the risk for a fall. Vitamin D supplementation is emerging as an easy, safe and well-tolerated fall reduction/prevention strategy due to the beneficial effects on the musculoskeletal system with improvements in strength, function and navigational abilities. From meta-analysis data, maximal fall reduction benefit in seniors is achieved when correcting vitamin D deficiency and when using adjunctive calcium supplementation. It is therefore recommended that practitioners in our state screen for fall risks and consider the addition of supplementation protocols that provide sufficient vitamin D and calcium to our seniors.

  5. Occlusion, optimization, emergency response and partial falls in a senior collapse detection system

    NASA Astrophysics Data System (ADS)

    Grewe, Lynne; Magaña-Zook, Steven

    2015-05-01

    Vision based fall detection systems must often contend with more issues than the need to simply identify true fall cases. All vision systems have areas of the frame they cannot see, occlusion, and this becomes of critical importance for systems monitoring for falls. Even with full scene visibility, human falls have an incredible variety requiring special detectors for edge cases like partial falls. Each detection algorithm is only as good as the parameters it is provided and so optimum values for each detector are found using Particle Swarm Optimization. We then discuss the use of email and short message service (SMS) in alerting caregivers that a fall has occurred.

  6. Terrestrial impact melt rocks and glasses

    NASA Astrophysics Data System (ADS)

    Dressler, B. O.; Reimold, W. U.

    2001-12-01

    The effects of meteorite and comet impact on Earth are rock brecciation, the formation of shock metamorphic features, rock melting, and the formation of impact structures, i.e. simple craters, complex craters, and multi-ring basins. Large events, such as the 65-Ma Chicxulub impact, are believed to have had catastrophic environmental effects that profoundly influenced the development of life on Earth. In this review, an attempt is made to summarize some of the voluminous literature on impact melting, one important aspect of planetary impact, provide some comments on this process, and to make suggestions for future research. The products of impact melting are glasses, impact melt rocks, and pseudotachylites. Our treatise deals mainly with the geological setting, petrography, and major-element chemistry of melt rocks and glasses. Impact glasses, in several petrographic aspects, are similar to volcanic glasses, but they are associated with shock metamorphosed mineral and rock fragments and, in places, with siderophile element anomalies suggestive of meteoritic contamination. They are found in allogenic breccia deposits within (fall-back 'suevite') and outside (fall-out 'suevite') impact craters and, as spherules, in distal ejecta. Large events, such as the K/T boundary Chicxulub impact, are responsible for the formation of worldwide ejecta horizons which are associated with siderophile element anomalies and shock metamorphosed mineral and rock debris. Impact glasses have a bulk chemical composition that is homogeneous but exemptions to this rule are common. On a microscopic scale, however, impact glasses are commonly strikingly heterogeneous. Tektites are glasses ejected from craters over large distances. They are characterized by very low water and volatile contents and element abundances and ratios that are evidence that tektites formed by melting of upper crustal, sedimentary rocks. Four tektite strewn-fields are known, three of which can be tied to specific impact

  7. The hazard and risk classification for large unstable rock slopes in Norway

    NASA Astrophysics Data System (ADS)

    Hermanns, R. L.; Oppikofer, T.; Anda, E.; Berg, H.; Blikra, L. H.; Böhme, M.; Bunkholt, H.; Crosta, G. B.; Dahle, H.; Fischer, L.; Jaboyedoff, M.; Loew, S.; Yugsi Molina, F. X.

    2012-12-01

    Catastrophic failure of large rock slopes led several times per century in Norway to rock avalanches or large rock falls, which impacted into settlements directly but also caused either a displacement wave when impacting a water body or damming of narrow valleys that impacred settlements in distance with often deadly consequences. Such events will also occur in future. In order to make mitigation of the negative consequences of such events possible, the Geological Survey of Norway (NGU) following its obligation towards society and the Norwegian Water and Energy Directorate (NVE) carries out systematic geologic mapping of potentially unstable rock slopes that might fail catastrophically. Within the last years systematic mapping in only three of the 17 counties of Norway has revealed more than 300 sites of potential future rock slope failures. This number necessitates prioritization of follow-up activities, such as periodic and permanent monitoring and early-warning. This quantitative hazard and risk classification system was build to compare sites so that political and financial decisions can be taken. The classification system is scenario-based as intensity and rate of displacement, as well as the geological structures activated by the sliding rock mass vary significantly on slopes. In addition, for each scenario the secondary effects, such as generation of displacement waves or landslide damming of valleys with the potential of later outburst floods, have to be evaluated. The hazard classification is based on two sets of criteria: 1) Structural site investigations including analysis of the development of the back-scarp, lateral limits and basal sliding surface. This includes a kinematic analysis that tests if rock sliding or toppling is kinematically feasible with respect to the slope orientation, the persistence of main structures and the morphologic expression of the sliding surface. 2) The analysis of the activity of the slope is primarily based on the slide

  8. From Rock to Magmatic Timescales in 25 Hours: Near-Real Time Petrological Volcanic Eruption Monitoring Tested with Basaltic Icelandic Tephras

    NASA Astrophysics Data System (ADS)

    Couperthwaite, F.; Morgan, D. J.; Thordarson, T.; Shea, T.; Harvey, J.

    2016-12-01

    crustal residence. Being able to retrieve this information within a day or so of the start of an eruption has exciting implications for eruption monitoring and hazard mitigation.

  9. The fracture criticality of crustal rocks

    NASA Astrophysics Data System (ADS)

    Crampin, Stuart

    1994-08-01

    The shear-wave splitting observed along almost all shear-wave ray paths in the Earth's crust is interpreted as the effects of stress-aligned fluid-filled cracks, microcracks, and preferentially oriented pore space. Once away from the free surface, where open joints and fractures may lead to strong anisotropy of 10 per cent or greater, intact ostensibly unfractured crustal rock exhibits a limited range of shear-wave splitting from about 1.5 to 4.5 per cent differential shear-wave velocity anisotropy. Interpreting this velocity anisotropy as normalized crack densities, a factor of less than two in crack radius covers the range from the minimum 1.5 per cent anisotropy observed in intact rock to the 10 per cent observed in heavily cracked almost disaggregated near-surface rocks. This narrow range of crack dimensions and the pronounced effect on rock cohesion suggests that there is a state of fracture criticality at some level of anisotropy between 4.5 and 10 per cent marking the boundary between essentially intact, and heavily fractured rock. When the level of fracture criticality is exceeded, cracking is so severe that there is a breakdown in shear strength, the likelihood of progressive fracturing and the dispersal of pore fluids through enhanced permeability. The range of normalized crack dimensions below fracture criticality is so small in intact rock, that any modification to the crack geometry by even minor changes of conditions or minor deformation (particularly in the presence of high pore-fluid pressures) may change rock from being essentially intact (below fracture criticality) to heavily fractured (above fracture criticality). This recognition of the essential compliance of most crustal rocks, and its effect on shear-wave splitting, has implications for monitoring changes in any conditions affecting the rock mass. These include monitoring changes in reservoir evolution during hydrocarbon production and enhanced oil recovery, and in monitoring changes before

  10. Design of field test plots for a sloped waste rock surface

    SciTech Connect

    O`Kane, M.; Stoicescu, J.; Haug, M.; Januszewski, S.; Mchaina, D.M.

    1998-12-31

    Westmin Resources Limited is a Western Canadian mining company with producing interests in base and precious metals and coals. Westmin`s Myra Falls Operations produce copper, zinc, and gold concentrates. The Myra Falls Operations are located in the central interior of Vancouver Island in a hanging glacial valley. Mean annual precipitation is approximately 3,000 mm with more than 75% occurring during the months of October to April. Historic surface deposition of waste rock has resulted in acid rock drainage (ARD). An applied research program was initiated to develop a cover system for the waste rock material at the Myra Falls site. The objective is to develop a cover system which controls the ingress of oxygen and infiltration of water, while providing a medium for sustainable vegetation that is consistent with the end land use of the area. Progress to date suggests that modified local till materials (amended with either fly ash or bentonite) can be used in soil cover construction. Four test plots were designed using two-dimensional saturated-unsaturated modelling tools to ensure that the performance of each test plot was representative of a full scale ARD cover system. This paper summarizes the design philosophy and principles of the cover system as well as the methodology for the two-dimensional numerical modelling program. Conclusions and results from the numerical modelling program are presented with a focus on implications for construction of the field test plots and installation of the performance monitoring instruments. The numerical modelling demonstrated that the hydraulic performance of a soil cover system placed on a sloped waste rock surface will be much different than that predicted by idealized one-dimensional numerical models, and in general current design methodologies. The modelling clearly demonstrated that the design of small scale field test plots was not a simple task. The physical dimensions of the field test plots had a significant impact on

  11. The Rock that Hit New York

    SciTech Connect

    Meade, Roger Allen; Keksis, August Lawrence

    2016-10-03

    On January 12, 1975, a rock seemed to fall from the sky over New York State’s Schoharie County hitting the tractor of a local farmer, who was “preparing his fields for spring planting.” As the farmer later described the event to a reporter from the UFO INVESTIGATOR, the object glanced off the tractor, fell to the ground, and melted its way through a patch of ice that was two and one half inches thick. The farmer, Leonard Tillapaugh, called the county sheriff, Harvey Stoddard, who recovered the rock, noting that it “was still warm.” Why and how a sample of the rock came to Los Alamos is not known. However, it captivated a wide Laboratory audience, was subjected to rigorous testing and evaluation. Los Alamos used the scientific method in the manner promoted by Hynek. Did Los Alamos solve the mystery of the rock’s origin? Not definitively. Although the exact origin could not be determined, it was shown conclusively that the rock was not from outer space. With that said, the saga of Rock that hit New York came to an end. Nothing more was said or written about it. The principals involved have long since passed from the scene. The NICAP ceased operations in 1980. And, the rock, itself, has disappeared.

  12. Evaluation of an inpatient fall risk screening tool to identify the most critical fall risk factors in inpatients.

    PubMed

    Hou, Wen-Hsuan; Kang, Chun-Mei; Ho, Mu-Hsing; Kuo, Jessie Ming-Chuan; Chen, Hsiao-Lien; Chang, Wen-Yin

    2017-03-01

    monitored by nurses to prevent falling during hospitalisations. © 2016 John Wiley & Sons Ltd.

  13. Rock-Fluid Interactions Under Stress: How Rock Microstructure Controls The Evolution of Porosity and Permeability

    NASA Astrophysics Data System (ADS)

    Vanorio, T.

    2016-12-01

    Monitoring chemo-mechanical processes geophysically — e.g., fluid disposal or storage, thermal and chemical stimulation of reservoirs, or natural fluids simply entering a new system in the subsurface— raises numerous concerns because of the likelihood of fluid-rock chemical interactions and our limited ability to decipher the geophysical signature of coupled processes. One of the missing links is coupling the evolution of porosity, permeability, and velocity of rocks together with reactive transport, since rocks deform and their microstructure evolves, as a result of chemical reactions under stress. This study describes recent advances in rock-physics experiments to understand the effects of dissolution-induced compaction on acoustic velocity, porosity, and permeability. Data observation includes time-lapse experiments and imaging tracking transport and elastic properties, the rock microstructure, and the pH and chemical composition of the fluid permeating the rock. Results show that the removal of high surface area, mineral phases such as microcrystalline calcite and clay appears to be mostly responsible for dissolution-induced compaction. Nevertheless, it is the original rock microstructure and its response to stress that ultimately defines how solution-transfer and rock compaction feed back upon each other. This work has a dual aim: understanding the mechanisms underlying permanent modifications to the rock microstructure and providing a richer set of experimental information to inform the formulation of new simulations and rock modeling.

  14. Geotechnical Descriptions of Rock and Rock Masses.

    DTIC Science & Technology

    1985-04-01

    user of the field log can relate to the general class of rock being described. For example, the rock name " syenite " might be qualified by adding "the...FELDSPAR PRE-S---- Coarne Texture Granite Syenite Qts ononite Honzonite Cabbro Peridotite (Platonic or to Qtx Diorite to Diorite Pyroxenite intrusive

  15. Understanding slope behavior through microseismic monitoring

    NASA Astrophysics Data System (ADS)

    Arosio, Diego; Boccolari, Mauro; Longoni, Laura; Papini, Monica; Zanzi, Luigi

    2017-04-01

    It is well known that microseismic activity originates as an elastic stress wave at locations where the material is mechanically unstable. Monitoring techniques focusing on this phenomenon have been studied for over seventy years and are now employed in a wide range of applications. As far as the study of unstable slope is concerned, microseismic monitoring can provide real-time information about fracture formation, propagation and coalescence and may be an appropriate solution to reduce the risk for human settlements when structural mitigation interventions (e.g., rock fall nets and ditches) cannot cope with large rock volumes and high kinetic energies. In this work we present the datasets collected in a 4-year period with a microseismic monitoring network deployed on an unstable rock face in Northern Italy. We mainly focus on the classification and the interpretation of collected signals with the final aim of identifying microseismic events related to the kinematic and dynamic behavior of the slope. We have analyzed signal parameters both in time and frequency domains, spectrograms, polarization of 3-component recordings supported by principal component analysis. Clustering methodologies have been tested in order to develop an automatic classification routine capable to isolate a cluster with most of the events related to slope behavior and to discard all disturbances. The network features both geophones and meteorological sensors so that we could also explore the correlation between microseismic events and meteorological datasets, although no significant relationships emerged. On the contrary, it was found that the majority of the events collected by the network are short-time high-frequency signals generated by electromagnetic activity caused by near and far thunderstorms. Finally, we attempted a preliminary localization of the most promising events according to an oversimplified homogeneous velocity model to get a rough indication about the regions of the

  16. Respirable dust measured downwind during rock dust application.

    PubMed

    Harris, M L; Organiscak, J; Klima, S; Perera, I E

    2017-05-01

    The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

  17. Chromian spinels from Apollo 14 rocks.

    NASA Technical Reports Server (NTRS)

    Steele, I. M.

    1972-01-01

    Results of electron microprobe analysis of 13 pink, isotropic, high-relief grains from Apollo 14 elastic rock 14063,14 and a lithic fragment from the 1 to 2 mm fines, 14002,7, identifying them as spinel minerals dominated by the spinel component MgAl2O4 associated with a moderate content of chromite and hercynite. The spinel is thought to have crystallized from a magma high in aluminum and low in iron, with possible crystal separation, followed by incorporation in clastic rocks by impacts. Many bulk compositions of the elastic fragments fall near the field of primary spinel in the model system An-Fo-SiO2. Experimental syntheses of Apollo 14 rocks are needed to test the suggested primary origin.

  18. Chromian spinels from Apollo 14 rocks.

    NASA Technical Reports Server (NTRS)

    Steele, I. M.

    1972-01-01

    Results of electron microprobe analysis of 13 pink, isotropic, high-relief grains from Apollo 14 elastic rock 14063,14 and a lithic fragment from the 1 to 2 mm fines, 14002,7, identifying them as spinel minerals dominated by the spinel component MgAl2O4 associated with a moderate content of chromite and hercynite. The spinel is thought to have crystallized from a magma high in aluminum and low in iron, with possible crystal separation, followed by incorporation in clastic rocks by impacts. Many bulk compositions of the elastic fragments fall near the field of primary spinel in the model system An-Fo-SiO2. Experimental syntheses of Apollo 14 rocks are needed to test the suggested primary origin.

  19. Conditioning of sandhill cranes during fall migration

    USGS Publications Warehouse

    Krapu, Gary L.; Johnson, Douglas H.

    1990-01-01

    Body mass of adult female and male sandhill cranes (Grus canadensis) increased an average of 17 and 20%, respectively, from early September to late October on staging areas in central North Dakota and varied by year. Increases in body mass averaged 550 and 681 g among female and male G. c. canadensis, respectively, and 616 and 836 g among female and male G. c. rowani. Adult and juvenile G. c. rowani were lean at arrival, averaging 177 and 83 g of fat, respectively, and fat reserves increased to 677 and 482 g by mid-October. Fat-free dry mass increased by 12% among juveniles, reflecting substantial growth, but remained constant among adults. The importance of fall staging areas as conditioning sites for sandhill cranes, annual variation in body mass, and vulnerability of cranes to habitat loss underscore the need to monitor status of fall staging habitat in the northern plains region and to take steps to maintain suitable habitat where necessary.

  20. Zapped, Martian Rock

    NASA Image and Video Library

    2013-02-20

    This image from the Mars Hand Lens Imager MAHLI on NASA Mars rover Curiosity shows details of rock texture and color in an area where the rover Dust Removal Tool DRT brushed away dust that was on the rock.

  1. The Rock Cycle

    ERIC Educational Resources Information Center

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  2. Theory of wing rock

    NASA Technical Reports Server (NTRS)

    Hsu, C.-H.; Lan, C. E.

    1985-01-01

    Wing rock is one type of lateral-directional instabilities at high angles of attack. To predict wing rock characteristics and to design airplanes to avoid wing rock, parameters affecting wing rock characteristics must be known. A new nonlinear aerodynamic model is developed to investigate the main aerodynamic nonlinearities causing wing rock. In the present theory, the Beecham-Titchener asymptotic method is used to derive expressions for the limit-cycle amplitude and frequency of wing rock from nonlinear flight dynamics equations. The resulting expressions are capable of explaining the existence of wing rock for all types of aircraft. Wing rock is developed by negative or weakly positive roll damping, and sustained by nonlinear aerodynamic roll damping. Good agreement between theoretical and experimental results is obtained.

  3. Rocks in Our Pockets

    ERIC Educational Resources Information Center

    Plummer, Donna; Kuhlman, Wilma

    2005-01-01

    To introduce students to rocks and their characteristics, teacher can begin rock units with the activities described in this article. Students need the ability to make simple observations using their senses and simple tools.

  4. The Rock Cycle

    ERIC Educational Resources Information Center

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  5. Rocks and Minerals.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

    Provides background information on rocks and minerals, including the unique characteristics of each. Teaching activities on rock-hunting and identification, mineral configurations, mystery minerals, and growing crystals are provided. Reproducible worksheets are included for two of the activities. (TW)

  6. Rocks and Minerals.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

    Provides background information on rocks and minerals, including the unique characteristics of each. Teaching activities on rock-hunting and identification, mineral configurations, mystery minerals, and growing crystals are provided. Reproducible worksheets are included for two of the activities. (TW)

  7. Rocks in Our Pockets

    ERIC Educational Resources Information Center

    Plummer, Donna; Kuhlman, Wilma

    2005-01-01

    To introduce students to rocks and their characteristics, teacher can begin rock units with the activities described in this article. Students need the ability to make simple observations using their senses and simple tools.

  8. Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River fall Chinook salmon ESU, 1/1/2012 – 12/31/2013: Annual report, 1991-029-00

    USGS Publications Warehouse

    Connor, William P.; Mullins, Frank; Tiffan, Kenneth F.; Perry, Russell W.; Erhardt, John M.; St. John, Scott J.; Bickford, Brad; Rhodes, Tobyn

    2014-01-01

    The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2014 in association with U.S. Endangered Species Act recovery efforts and other Federally mandated actions. This annual report focuses on (1) numeric and habitat use responses by natural- and hatchery-origin spawners, (2) phenotypic and numeric responses by natural-origin juveniles, and (3) predator responses in the Snake River upper and lower reaches as abundance of adult and juvenile fall Chinook Salmon increased. Spawners have located and used most of the available spawning habitat and that habitat is gradually approaching redd capacity. Timing of spawning and fry emergence has been relatively stable; whereas the timing of parr dispersal from riverine rearing habitat into Lower Granite Reservoir has become earlier as apparent abundance of juveniles has increased. Growth rate (g/d) and dispersal size of parr also declined as apparent abundance of juveniles increased. Passage timing of smolts from the two Snake River reaches has become earlier and downstream movement rate faster as estimated abundance of fall Chinook Salmon smolts in Lower Granite Reservoir has increased. In 2014, consumption of subyearlings by Smallmouth Bass was highest in the upper reach which had the highest abundance of Bass. With a few exceptions, predation tended to decrease seasonally from April through early July. A release of hatchery fish in mid-May significantly increased subyearling consumption by the following day. We estimated that over 600,000 subyearling fall Chinook Salmon were lost to Smallmouth Bass predation along the free-flowing Snake River in 2014. More information on predation is presented in Appendix A.3 (page 51). These findings coupled with stock-recruitment analyses presented in this report provide evidence for density-dependence in the Snake River reaches and in Lower Granite Reservoir that was

  9. Fall Harvest in Kazakhstan

    NASA Image and Video Library

    2017-09-27

    September 22, the autumnal equinox, marks the beginning of fall in the Northern Hemisphere, but the fall harvest begins early in the harsh continental climate of eastern Kazakhstan. By September 9, 2013, when the Operational Land Imager (OLI) on the Landsat 8 satellite acquired this image, several fields were already harvested and bare. Others were dark green with pasture grasses or ripening crops. The fields fill the contours of the land, running long and narrow down mountain valleys and spreading in large squares over the plains. Agriculture is an important segment of the economy in Kazakhstan: the country’s dry climate is ideal for producing high quality wheat for export. However, 61 percent of the country’s agricultural land is pasture for livestock. The area shown in this image, far eastern Kazakhstan near the Chinese border, is a minor wheat-growing region and may also produce sunflowers, barley, and other food crops. An artifact of Soviet-era collective farms, most of the farms in Kazakhstan are large, covering more than 5,000 hectares (12,500 acres). Some of the larger fields in the image reflect the big business side of agriculture. However, family farms and small agriculture businesses account for 35 percent of the country’s agricultural production, and some of these are visible as well, particularly in the uneven hills and mountains. Nearly all agriculture in Kazakhstan is rain fed. Farmers in this region have designed their fields to take advantage of rain flowing down hills, allowing the natural shape of the land to channel water to crops. The effect is a mosaic of green and tan with tones matching the natural vegetation in the mountains to the north. NASA Earth Observatory image by Jesse Allen using Landsat data from the U.S. Geological Survey. Caption by Holli Riebeek. Instrument: Landsat 8 - OLI More info: 1.usa.gov/16IZ047 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth

  10. Principles of rock deformation

    SciTech Connect

    Nicolas, A.

    1987-01-01

    This text focuses on the recent achievements in the analysis of rock deformation. It gives an analytical presentation of the essential structures in terms of kinetic and dynamic interpretation. The physical properties underlying the interpretation of rock structures are exposed in simple terms. Emphasized in the book are: the role of fluids in rock fracturing; the kinematic analysis of magnetic flow structures; the application of crystalline plasticity to the kinematic and dynamic analysis of the large deformation imprinted in many metamorphic rocks.

  11. Student Profile, Fall 1977 to Fall 1986. Historical Profiles Project.

    ERIC Educational Resources Information Center

    California Community Colleges, Sacramento. Office of the Chancellor.

    The tables and graphs presented in this report reflect changes in community college enrollments in California over the past 10 years (fall 1977 to fall 1986), as they have responded to fluctuations in the state's economy, available state revenues, and community college funding. First, an executive summary highlights the following trends over the…

  12. 68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: ...

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

    68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: STRESS SHEET, SHEET 4; MAY, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  13. Mobility, Balance and Falls in Persons with Multiple Sclerosis

    PubMed Central

    Sosnoff, Jacob J.; Socie, Michael J.; Boes, Morgan K.; Sandroff, Brian M.; Pula, John H.; Suh, Yoojin; Weikert, Madeline; Balantrapu, Swathi; Morrison, Steven; Motl, Robert W.

    2011-01-01

    Background There is a lack of information concerning the relation between objective measures of gait and balance and fall history in persons with MS (PwMS). This investigation assessed the relation between demographic, clinical, mobility and balance metrics and falls history in persons with multiple sclerosis (MS). Methods 52 ambulatory persons with MS (PwMS) participated in the investigation. All persons provided demographic information including fall history over the last 12 months. Disease status was assessed with Expanded Disability Status Scale (EDSS). Walking speed, coordination, endurance and postural control were quantified with a multidimensional mobility battery. Results Over 51% of the participants fell in the previous year with 79% of these people being suffering recurrent falls. Overall, fallers were older, had a greater prevalence of assistive devices use, worse disability, decreased walking endurance, and greater postural sway velocity with eyes closed compared to non-fallers. Additionally, fallers had greater impairment in cerebellar, sensory, pyramidal, and bladder/bowel subscales of the EDSS. Conclusions The current observations suggest that PwMS who are older, more disabled, utilize an assistive device, have decreased walking coordination and endurance and have diminished balance have fallen in the previous year. This suggests that individuals who meet these criteria need to be carefully monitored for future falls. Future research is needed to determine a prospective model of falls specific to PwMS. Additionally, the utility of interventions aimed at reducing falls and fall risk in PwMS needs to be established. PMID:22132196

  14. My Pet Rock

    ERIC Educational Resources Information Center

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  15. My Pet Rock

    ERIC Educational Resources Information Center

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  16. Post Falls Dam stabilization

    SciTech Connect

    Gorny, R.H.; Gibson, J.Z.

    1995-12-31

    The stability of Washington Water Power`s (WWP) Middle Channel and South Channel Dams at Post Falls, Idaho, were evaluated as required by the Federal Energy Regulatory Commission (FERC) and did not meet guideline stability criteria under Probable Maximum Flood (PMF) loading. This paper describes the stability analysis, stabilization design, design parameters, construction of the anchors, and compares the design and as-built conditions. Value engineering was used to select the optimal stabilization measure. Constructibility, cost, and schedule were major considerations. The value engineering study evaluated 41 potential stabilization alternatives, selected post tensioning, and used scheduling criteria to optimize the design. Access considerations required the installation of five 47 strand, 7400 kN (1645{sup k}) anchors in the Middle Dam, and installation of six anchors with different capacities anchors in the South Channel Dam. The Washington Water Power - Black & Veatch team used value engineering, contractor prequalification, resident engineering services provided by the engineer, and strong construction support provided by the Owner to successfully complete the project on a very tight schedule.

  17. 1991 Fall Meeting Report

    NASA Astrophysics Data System (ADS)

    Chapman, David S.

    The AGU 1991 Fall Meeting, held in San Francisco December 9-13, was the largest national AGU meeting ever held. Meeting participation continued the steady growth trend set throughout the previous decade. A total of 4,037 papers and posters were presented, and by Friday noon of the meeting over 5,500 members had registered.Several special events were scheduled to inform and engage members on societal and programmatic aspects of our science. AGU's Committee on Education and Human Resources sponsored an open forum that addressed opportunities and problems associated with dual-career couples. A discussion of NASA's strategic plan by Berrien Moore and Joseph Alexander drew a large audience, and a special session on societal aspects of the Mt. Pinatubo eruption drew an overflow crowd. Two special lectures— “Plumes, Plates, and Deep Earth Structure” by Don L. Anderson and “New Frontiers in Aeronomy: Effects of Global Atmospheric Change” by P. M. Banks-also drew overflow crowds.

  18. Spirit Guidepost, 'Plymouth Rock'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit took this panoramic camera image during Spirit's 152nd sol, on June 7, 2004. The rock, informally named 'Plymouth Rock,' is approximately 90 centimeters (35 inches) across and 50 centimeters (20 inches) tall. Spirit did not spend any time studying Plymouth Rock, but rover controllers used it as a guide to maneuver Spirit closer to the 'Columbia Hills.' Like most of the rocks found at the Gusev crater location, Plymouth is most likely a basalt. The tiny vesicles pitting the rock's surface further indicate its volcanic origin.

  19. Rock ramp design guidelines

    USGS Publications Warehouse

    Mooney, David M.; Holmquist-Johnson, Christopher L.; Broderick, Susan

    2007-01-01

    Rock ramps or roughened channels consist of steep reaches stabilized by large immobile material (riprap). Primary objectives for rock ramps include: Create adequate head for diversionMaintain fish passage during low-flow conditionsMaintain hydraulic conveyance during high-flow conditionsSecondary objectives for rock ramp design include:Emulate natural systemsMinimize costsThe rock ramp consists of a low-flow channel designed to maintain biologically adequate depth and velocity conditions during periods of small discharges. The remainder of the ramp is designed to withstand and pass large flows with minimal structural damage. The following chapters outline a process for designing rock ramps.

  20. Not Just a Fall Tree

    ERIC Educational Resources Information Center

    Miller-Hewes, Kathy A.

    2004-01-01

    Trees burst with color in the northern states. Autumn leaves dust the ground. Painting the fall landscape is nothing new. Teachers have been doing it in classrooms for decades. The approach, however, can make the difference between whether the fall landscape is simply painting for fun, or a real learning experience. Students learn best when they…

  1. Not Just a Fall Tree

    ERIC Educational Resources Information Center

    Miller-Hewes, Kathy A.

    2004-01-01

    Trees burst with color in the northern states. Autumn leaves dust the ground. Painting the fall landscape is nothing new. Teachers have been doing it in classrooms for decades. The approach, however, can make the difference between whether the fall landscape is simply painting for fun, or a real learning experience. Students learn best when they…

  2. NOVA Fall 1999 Teacher's Guide.

    ERIC Educational Resources Information Center

    French, Wayne; Karlan, James W.; Ransick, Kristina; Rosene, Dale; Sammons, Fran Lyons; Sammons, James

    This teacher's guide complements five programs that aired on the Public Broadcasting System (PBS) in the fall of 1999. Programs include: (1) "Fall of the Leaning Tower"; (2) "Everest: The Mystery of Mallory and Irvine"; (3) "Time Travel, Decoding Nazi Secrets"; (3) "Voyage of Doom"; and (5) "Barely…

  3. Persistence. Snapshot Report, Fall 2011

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2011

    2011-01-01

    Today's college student is not your '60s drop-out. In 2010, college students tended to stay enrolled (i.e., persist), even if it was in a different school, according to the National Student Clearinghouse Research Center. For a student enrolled in the fall, persistence is defined as either continued enrollment during the next term after the fall or…

  4. [FALLS IN PATIENTS WITH DEMENTIA].

    PubMed

    Aizen, Efraim

    2015-05-01

    Older people with dementia are at increased risk of falls and their consequences. Patients with dementia fall twice as often as elderly cognitively intact people and are at greater risk of injurious falls. Falls in older people with dementia cause higher rates of morbidity, mortality and institutionalization. There is limited literature attempting to show specific risk factors for falls in this population, mainly: Lewy body dementia, dementia related to Parkinson's disease and depression, psychotropic medication, functional disability and behavioral disturbances. The Physiological Profile Assessment (PPAJ has been found to be a good fall risk screening tool in this population. There are few trials that have shown limited effectiveness of targeted fall prevention programs in community-dwelling cognitively impaired elderly. The evidence from hospitals and residential care is not conclusive. However, it has been demonstrated that some interventions, primarily exercise interventions, can modify certain risk factors in patients with dementia. Further research is required in specifically targeting fall prevention in older people with dementia.

  5. A hazard and risk classification system for catastrophic rock slope failures in Norway

    NASA Astrophysics Data System (ADS)

    Hermanns, R.; Oppikofer, T.; Anda, E.; Blikra, L. H.; Böhme, M.; Bunkholt, H.; Dahle, H.; Devoli, G.; Eikenæs, O.; Fischer, L.; Harbitz, C. B.; Jaboyedoff, M.; Loew, S.; Yugsi Molina, F. X.

    2012-04-01

    The Geological Survey of Norway carries out systematic geologic mapping of potentially unstable rock slopes in Norway that can cause a catastrophic failure. As catastrophic failure we describe failures that involve substantial fragmentation of the rock mass during run-out and that impact an area larger than that of a rock fall (shadow angle of ca. 28-32° for rock falls). This includes therefore rock slope failures that lead to secondary effects, such as a displacement wave when impacting a water body or damming of a narrow valley. Our systematic mapping revealed more than 280 rock slopes with significant postglacial deformation, which might represent localities of large future rock slope failures. This large number necessitates prioritization of follow-up activities, such as more detailed investigations, periodic monitoring and permanent monitoring and early-warning. In the past hazard and risk were assessed qualitatively for some sites, however, in order to compare sites so that political and financial decisions can be taken, it was necessary to develop a quantitative hazard and risk classification system. A preliminary classification system was presented and discussed with an expert group of Norwegian and international experts and afterwards adapted following their recommendations. This contribution presents the concept of this final hazard and risk classification that should be used in Norway in the upcoming years. Historical experience and possible future rockslide scenarios in Norway indicate that hazard assessment of large rock slope failures must be scenario-based, because intensity of deformation and present displacement rates, as well as the geological structures activated by the sliding rock mass can vary significantly on a given slope. In addition, for each scenario the run-out of the rock mass has to be evaluated. This includes the secondary effects such as generation of displacement waves or landslide damming of valleys with the potential of later

  6. Youth Attitude Tracking Study. Fall 1975.

    DTIC Science & Technology

    1976-02-01

    AD-fl143 M8 YOUTH ATTITUDE TRACKING STUDY FALL 1975(U) MARKET FRCTS 1/2 RO-11IL4 INC CHICAGO IL J T HEISLER FEB 76 9221 UNCLAS DMDC/MRB-TR-75/i onl8... Market Facts, Inc. Job No. 9Z21 100 South Wacker Drive3 OMB 0 22-R-0339 Chicago, Illinois 60606 February, 1976 I S SE.liY’ L.LA ,AItJ,N O.r ?rIIS$ A...NAME OF MONITORING ORGANIZATION Market Facts, Inc. (if applicable) Defense Manpower Data Center (DMDC) 6c ADDRESS (City. State, and ZIPCode) lb. ADDRESS

  7. [Epidemiology of falls among the elderly].

    PubMed

    Mancini, Cristina; Williamson, David; Binkin, Nancy; Michieletto, Federica; De Giacomi, Giovanna Valentina

    2005-01-01

    home. Risk factors for falls included stroke (adjusted RR = 1.4 (95% CI = 1.03-1.8)). diabetes (adjusted RR = 1.7 (95% CI = 1.2-2.1)). visual difficulties (adjusted RR = 1.3 (95% CI = 1.02-1.6)). urinary incontinence (adjusted RR = 1.3 (95%CI= 1.1-1.5) and physical inactivity (adjusted RR = 1.3 (95% CI = 1.03-1.5)). In addition, the consumption of anti-anxiety drugs was also associated with a greater risk of falls. The highest population-attributable fractions were seen for urinary incontinence (9.4%) and lack of physical activity (10.0%). Falls are common in Italian elderly and are linked with the fragility of aging. To prevent falls, it is necessary to intervene on factors associated with fragility. Methods include encouraging regular physical activity to improve equilibrium and muscle strength and the continuous monitoring of health status to prevent further deterioration. Moreover studies carried out in other countries have demonstrated that the multidisciplinary interventions targeted at persons who have already experienced a fall reduces their risk of further falls. These interventions consist of evaluations of visual acuity, balance, and gait and a review of clinical history with eventual modifications of drug therapy and the environmental risks in the home.

  8. Cowlitz Falls Fish Passage.

    SciTech Connect

    1995-09-01

    The upper Cowlitz was once home to native salmon and steelhead. But the combined impacts of overharvest, farming, logging and road building hammered fish runs. And in the 1960s, a pair of hydroelectric dams blocked the migration path of ocean-returning and ocean-going fish. The lower Cowlitz still supports hatchery runs of chinook, coho and steelhead. But some 200 river miles in the upper river basin--much of it prime spawning and rearing habitat--have been virtually cut off from the ocean for over 26 years. Now the idea is to trap-and-haul salmon and steelhead both ways and bypass previously impassable obstacles in the path of anadromous fish. The plan can be summarized, for the sake of explanation, in three steps: (1) trap and haul adult fish--collect ocean-returning adult fish at the lowermost Cowlitz dam, and truck them upstream; (2) reseed--release the ripe adults above the uppermost dam, and let them spawn naturally, at the same time, supplement these runs with hatchery born fry that are reared and imprinted in ponds and net pens in the watershed; (3) trap and haul smolts--collection the new generation of young fish as they arrive at the uppermost Cowlitz dam, truck them past the three dams, and release them to continue their downstream migration to the sea. The critical part of any fish-collection system is the method of fish attraction. Scientists have to find the best combination of attraction system and screens that will guide young fish to the right spot, away from the turbine intakes. In the spring of 1994 a test was made of a prototype system of baffles and slots on the upriver face of the Cowlitz Falls Dam. The prototype worked at 90% efficiency in early tests, and it worked without the kind of expensive screening devices that have been installed on other dams. Now that the success of the attraction system has been verified, Harza engineers and consultants will design and build the appropriate collection part of the system.

  9. Data Collection Procedures and Descriptive Statistics for the Grade Two (Fall) Achievement Monitoring Tests (Baseline, S-4, S-5 and S-6), Coordinated Study No. 1. Working Paper No. 319. Report from the Project on Studies in Mathematics.

    ERIC Educational Resources Information Center

    Buchanan, Anne E.; Romberg, Thomas A.

    This paper is the second of a series of four reports that document the achievement monitoring component of a three-year study on the acquisition of addition-subtraction problem-solving skills by young children. A set of performance objectives contained in or ancillary to 10 instructional units on sentence-writing for verbal problems and algorithms…

  10. Radar fall detectors: a comparison

    NASA Astrophysics Data System (ADS)

    Erol, Baris; Amin, Moeness; Ahmad, Fauzia; Boashash, Boualem

    2016-05-01

    Falls are a major cause of accidents in elderly people. Even simple falls can lead to severe injuries, and sometimes result in death. Doppler fall detection has drawn much attention in recent years. Micro-Doppler signatures play an important role for the Doppler-based radar systems. Numerous studies have demonstrated the offerings of micro-Doppler characteristics for fall detection. In this respect, a plethora of micro-Doppler signature features have been proposed, including those stemming from speech recognition and wavelet decomposition. In this work, we consider four different sets of features for fall detection. These can be categorized as spectrogram based features, wavelet based features, mel-frequency cepstrum coefficients, and power burst curve features. Support vector machine is employed as the classifier. Performance of the respective fall detectors is investigated using real data obtained with the same radar operating resources and under identical sensing conditions. For the considered data, the spectrogram based feature set is shown to provide superior fall detection performance.

  11. Diagnosis and Tests: Evaluating a Fall or Risk of Falling

    MedlinePlus

    ... illnesses Your fear of falling and your mood Memory and brain functioning Risks in your home environment. Tests Your ... assess bone strength Heart assessments such as echocardiography Brain imaging such as CT ... therapy assessment A home safety evaluation. ...

  12. 9. VIEW OF ROCK SLIDE AND STONE RETAINING WALL ALONG ...

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

    9. VIEW OF ROCK SLIDE AND STONE RETAINING WALL ALONG THE RAILROAD GRADE ABOUT 3/4 MILE SOUTHWEST OF VIVIAN PARK, LOOKING SOUTHWEST - Heber Creeper Railroad Line, Section from Bridal Veil Falls to Vivian Park, Between Provo & Heber City, Provo, Utah County, UT

  13. SisFall: A Fall and Movement Dataset

    PubMed Central

    Sucerquia, Angela; López, José David; Vargas-Bonilla, Jesús Francisco

    2017-01-01

    Research on fall and movement detection with wearable devices has witnessed promising growth. However, there are few publicly available datasets, all recorded with smartphones, which are insufficient for testing new proposals due to their absence of objective population, lack of performed activities, and limited information. Here, we present a dataset of falls and activities of daily living (ADLs) acquired with a self-developed device composed of two types of accelerometer and one gyroscope. It consists of 19 ADLs and 15 fall types performed by 23 young adults, 15 ADL types performed by 14 healthy and independent participants over 62 years old, and data from one participant of 60 years old that performed all ADLs and falls. These activities were selected based on a survey and a literature analysis. We test the dataset with widely used feature extraction and a simple to implement threshold based classification, achieving up to 96% of accuracy in fall detection. An individual activity analysis demonstrates that most errors coincide in a few number of activities where new approaches could be focused. Finally, validation tests with elderly people significantly reduced the fall detection performance of the tested features. This validates findings of other authors and encourages developing new strategies with this new dataset as the benchmark. PMID:28117691

  14. Geothermal resource analysis in Twin Falls County, Idaho

    SciTech Connect

    Baker, S.J.; Castelin, P.M.

    1990-10-01

    Thermal water is prevalent throughout central Twin Falls County. Most wells and springs that occur in the area produce thermal water from fractures in the Idavada Volcanics. However, in an area east of Hollister, thermal water issues from fractures in the Paleozoic rocks. In an attempt to explain the hydrothermal relationship between these two reservoir rocks, one composite model for the entire geothermal system in the area is proposed. As with other conceptual models of the system, available geologic, hydrologic, and geochemical data were used to develop the model. The chemistry of the thermal water appears to be strongly governed by the chemical composition of the rocks that it comes in contact with and the length of time that it is exposed to them. The shorter flow paths to the south appear to occur entirely within the Paleozoic rocks, according to the calcium bicarbonate chemistry of the thermal water. As the flow paths become progressively longer toward the north, the thermal waters apparently encounter the silicic volcanics during their ascent. The chemistries of the thermal waters gradually equilibrate to the new host rock conditions and lose their Paleozoic signatures as exposure time increases. Ultimately, the chemistry of the thermal water changes to a sodium bicarbonate type.

  15. Bioremediation in Fractured Rock: 2. Mobilization of Chloroethene Compounds from the Rock Matrix.

    PubMed

    Shapiro, Allen M; Tiedeman, Claire R; Imbrigiotta, Thomas E; Goode, Daniel J; Hsieh, Paul A; Lacombe, Pierre J; DeFlaun, Mary F; Drew, Scott R; Curtis, Gary P

    2017-09-05

    A mass balance is formulated to evaluate the mobilization of chlorinated ethene compounds (CE) from the rock matrix of a fractured mudstone aquifer under pre- and postbioremediation conditions. The analysis relies on a sparse number of monitoring locations and is constrained by a detailed description of the groundwater flow regime. Groundwater flow modeling developed under the site characterization identified groundwater fluxes to formulate the CE mass balance in the rock volume exposed to the injected remediation amendments. Differences in the CE fluxes into and out of the rock volume identify the total CE mobilized from diffusion, desorption, and nonaqueous phase liquid dissolution under pre- and postinjection conditions. The initial CE mass in the rock matrix prior to remediation is estimated using analyses of CE in rock core. The CE mass mobilized per year under preinjection conditions is small relative to the total CE mass in the rock, indicating that current pump-and-treat and natural attenuation conditions are likely to require hundreds of years to achieve groundwater concentrations that meet regulatory guidelines. The postinjection CE mobilization rate increased by approximately an order of magnitude over the 5 years of monitoring after the amendment injection. This rate is likely to decrease and additional remediation applications over several decades would still be needed to reduce CE mass in the rock matrix to levels where groundwater concentrations in fractures achieve regulatory standards. © 2017, National Ground Water Association.

  16. Community College Estimated Growth: Fall 2010

    ERIC Educational Resources Information Center

    Phillippe, Kent; Mullin, Christopher M.

    2011-01-01

    A survey from the American Association of Community Colleges (AACC) found that enrollment growth in fall 2010 slowed its pace at community colleges, increasing 3.2% from the previous year. This contrasts with more dramatic increases in recent years: more than 11% between fall 2008 and fall 2009, and nearly 17% between fall 2007 and fall 2009,…

  17. Friction of rocks

    USGS Publications Warehouse

    Byerlee, J.

    1978-01-01

    Experimental results in the published literature show that at low normal stress the shear stress required to slide one rock over another varies widely between experiments. This is because at low stress rock friction is strongly dependent on surface roughness. At high normal stress that effect is diminished and the friction is nearly independent of rock type. If the sliding surfaces are separated by gouge composed of Montmorillonite or vermiculite the friction can be very low. ?? 1978 Birkha??user Verlag.

  18. Albeni Falls Wildlife Mitigation Project, 2001 Annual Report.

    SciTech Connect

    Terra-Burns, Mary

    2002-02-11

    The Albeni Falls Interagency Work Group was actively engaged in implementing wildlife mitigation activities in 2001. The Work Group met quarterly to discuss management and budget issues affecting the Albeni Falls Wildlife Mitigation Program. Work Group members protected 851 acres of wetland habitat in 2001. Wildlife habitat protected to date for the Albeni Falls project is approximately 5,248.31 acres ({approx}4,037.48 Habitat Units). Approximately 14% of the total wildlife habitat lost has been mitigated. Administrative activities increased as funding was more evenly distributed among Work Group members and protection opportunities became more time consuming. In 2001, Work Group members focused on development and implementation of the monitoring and evaluation program as well as completion of site-specific management plans. With the implementation of the monitoring and evaluation program, and as management plans are reviewed and executed, on the ground management activities are expected to increase in 2002.

  19. Highlights of 2012 Fall Meeting

    NASA Astrophysics Data System (ADS)

    Finn, Carol

    2013-01-01

    This past December the streets of San Francisco, Calif., surrounding the Moscone Center were awash with a sea of Earth and space scientists attending the 45th consecutive AGU Fall Meeting, eager to share and expand their knowledge "for the benefit of humanity." As it has for many years, attendance at AGU's Fall Meeting—the largest gathering of Earth and space scientists in the world—continued to increase, this year passing the 24,000 mark. Attendees at the meeting, which took place on 3-7 December 2012, hailed from 97 countries; nearly 7000 of them were students. News from the Fall Meeting was carried in newspapers and on Web sites around the world, and the social media sphere lit up with talk of AGU and the Fall Meeting. It's even reported that for a short time we were a trending topic on Twitter.

  20. Exercises to help prevent falls

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000493.htm Exercises to help prevent falls To use the sharing ... and easily. DO NOT hold your breath. Balance Exercises You can do some balance exercises during everyday ...

  1. Bounce Rock Dimple

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panoramic camera image shows the hole drilled by the Mars Exploration Rover Opportunity's rock abrasion tool into the rock dubbed 'Bounce' on Sol 65 of the rover's journey. The tool drilled about 7 millimeters (0.3 inches) into the rock and generated small piles of 'tailings' or rock dust around the central hole, which is about 4.5 centimeters (1.7 inches) across. The image from sol 66 of the mission was acquired using the panoramic camera's 430 nanometer filter.

  2. Opaque rock fragments

    SciTech Connect

    Abhijit, B.; Molinaroli, E.; Olsen, J.

    1987-05-01

    The authors describe a new, rare, but petrogenetically significant variety of rock fragments from Holocene detrital sediments. Approximately 50% of the opaque heavy mineral concentrates from Holocene siliciclastic sands are polymineralic-Fe-Ti oxide particles, i.e., they are opaque rock fragments. About 40% to 70% of these rock fragments show intergrowth of hm + il, mt + il, and mt + hm +/- il. Modal analysis of 23,282 opaque particles in 117 polished thin sections of granitic and metamorphic parent rocks and their daughter sands from semi-arid and humid climates show the following relative abundances. The data show that opaque rock fragments are more common in sands from igneous source rocks and that hm + il fragments are more durable. They assume that equilibrium conditions existed in parent rocks during the growth of these paired minerals, and that the Ti/Fe ratio did not change during oxidation of mt to hm. Geothermometric determinations using electron probe microanalysis of opaque rock fragments in sand samples from Lake Erie and the Adriatic Sea suggest that these rock fragments may have equilibrated at approximately 900/sup 0/ and 525/sup 0/C, respectively.

  3. Bounce Rock Dimple

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panoramic camera image shows the hole drilled by the Mars Exploration Rover Opportunity's rock abrasion tool into the rock dubbed 'Bounce' on Sol 65 of the rover's journey. The tool drilled about 7 millimeters (0.3 inches) into the rock and generated small piles of 'tailings' or rock dust around the central hole, which is about 4.5 centimeters (1.7 inches) across. The image from sol 66 of the mission was acquired using the panoramic camera's 430 nanometer filter.

  4. Hungry for Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image from the Mars Exploration Rover Spirit hazard identification camera shows the rover's perspective just before its first post-egress drive on Mars. On Sunday, the 15th martian day, or sol, of Spirit's journey, engineers drove Spirit approximately 3 meters (10 feet) toward its first rock target, a football-sized, mountain-shaped rock called Adirondack (not pictured). In the foreground of this image are 'Sashimi' and 'Sushi' - two rocks that scientists considered investigating first. Ultimately, these rocks were not chosen because their rough and dusty surfaces are ill-suited for grinding.

  5. Falls Among Older Adults: An Overview

    MedlinePlus

    ... health care providers. Learn More Important Facts about Falls Recommend on Facebook Tweet Share Compartir Each year, ... once doubles your chances of falling again. 2 Falls Are Serious and Costly One out of five ...

  6. Rasch validation of the falls prevention strategies survey.

    PubMed

    Finlayson, Marcia L; Peterson, Elizabeth W; Fujimoto, Ken A; Plow, Matthew A

    2009-12-01

    Finlayson ML, Peterson EW, Fujimoto KA, Plow MA. Rasch validation of the Falls Prevention Strategies Survey. To validate the Falls Prevention Strategies Survey. Cross-sectional descriptive survey design. With the use of Rasch analysis, the following aspects of the Falls Prevention Strategies Survey were evaluated: rating scale structure, item quality, participant fit and participant ability, invariance structure, and the potential to change in response to intervention. Community-based, national sample. Adult registrants of the North America Research Committee on Multiple Sclerosis volunteer patient registry (N=457). Not applicable. The Falls Prevention Strategies Survey is a self-report instrument addressing protective behaviors related to fall risk among adults with multiple sclerosis (MS) (eg, monitoring MS symptoms, wearing proper footwear, modifying activities). Response options reflect the frequency with which the respondent engages in the behavior (ie, never, sometimes, regularly). Analysis indicated that the rating scale structure (ie, response options) was valid. Of the original 19 items, 8 of them misfit and needed to be dropped to obtain a valid instrument under the Rasch model. With the final 11 items, the instrument was able to distinguish participants of different ability levels across a range of 11.58 logits. Invariance structure analysis demonstrated that the instrument functioned equally for men and women, for mobility device users and nonusers, and for participants with diagnosed MS for less than or greater than 10 years. Findings indicated that approximately 50% of respondents would have room to improve on their Falls Prevention Strategies Survey scores over time. Rasch analysis supports the use of the Falls Prevention Strategies Survey to examine the frequency of engaging in protective behaviors related to fall risk among adults with MS. The instrument shows potential to track outcomes of behaviorally oriented fall reduction interventions in this

  7. Pupil Membership and Related Information, Fall 1998.

    ERIC Educational Resources Information Center

    Wamboldt, Martina

    Information is provided about student membership in the Colorado public schools in 1998. In fall 1998, there were 699,135 students in Colorado's public schools, an increase of 11,968 students (1.7%) from fall 1997. Fall membership grew by 58,614 students (9.2%) from fall 1994 to fall 1998. Beginning in fall 1990, membership each year has surpassed…

  8. Physical and Chemical Effects of Two-Phase Brine/Supercritical-CO2 Fluid Flow on Clastic Rocks: Real-Time Monitoring and NMR Imaging of Flow-Through Core Experiments

    NASA Astrophysics Data System (ADS)

    Shaw, C. A.; Vogt, S.; Maneval, J. E.; Brox, T.; Skidmore, M. L.; Codd, S. L.; Seymour, J. D.

    2010-12-01

    Sandstone core samples were challenged with a supercritical CO2-saturated brine mixture in a laboratory flow-through core reactor system over a range of temperatures and brine strengths. Cores of quartz arenite from the Berea formation were selected to represent ideal ‘clean’ sandstone These laboratory experiments potentially provide an analog for the acidification of pore fluids near the brine/CO2 interface during CO2 flooding of depleted clastic hydrocarbon reservoirs for carbon sequestration. Flow in the reactor was perpendicular to bedding. Initial experiments were run at 50°C and 100°C with brine concentrations of 1g/L and 10g/L (TDS) to test effects of different temperatures and brine compositions. Real-time monitoring of fluid pH and conductivity provided a measure of reaction rates. Introduction of supercritical CO2 into the brine-saturated cores initiated a reduction in pH accompanied by an increase in conductivity. NMR images of fresh cores were compared with images of challenged cores using a protocol for pixel-by-pixel comparison to determine the effects on bulk pore volume and geometry. Two types of imaging experiments were conducted: multi-slice spin echo and 3-D spin echo images. Multi-slice experiments had a slice thickness of 1.5 mm and an in-plane resolution of 0.27 mm x 0.27 mm, and 3-D experiments had a resolution of 0.47 mm x 0.55 mm x 0.55mm. Imaging results reflected the observed changes in the physical and chemical structure post-challenge. Two-dimensional relaxation correlation experiments were also conducted to probe the pore sizes, connectivity and fluid saturation of the rock cores before and after challenging. Chemical analyses and microscopic examination of the challenged cores will provide a better understanding of alteration in the cores and the changes in the volume, geometry and connectivity of pore space.

  9. Mars Rock Analysis Briefing

    NASA Image and Video Library

    2013-03-12

    John Grotzinger (second from left), Curiosity project scientist, California Institute of Technology in Pasadena, speaks at a news conference presenting findings of the Curiosity rover's analysis of the first sample of rock powder collected on Mars, Tuesday, March 12, 2013 in Washington. The rock sample collected shows ancient Mars could have supported living microbes. Photo Credit: (NASA/Carla Cioffi)

  10. Mars Rock Analysis Briefing

    NASA Image and Video Library

    2013-03-12

    John Grotzinger, Curiosity project scientist, California Institute of Technology in Pasadena, answers a reporter's question at a news conference where findings of the Curiosity rover's analysis of the first sample of rock powder collected on Mars were presented, Tuesday, March 12, 2013 in Washington. The rock sample collected shows ancient Mars could have supported living microbes. Photo Credit: (NASA/Carla Cioffi)

  11. Mars Rock Analysis Briefing

    NASA Image and Video Library

    2013-03-12

    John Grotzinger (center), Curiosity project scientist, California Institute of Technology in Pasadena, speaks at a news conference presenting findings of the Curiosity rover's analysis of the first sample of rock powder collected on Mars, Tuesday, March 12, 2013 in Washington. The rock sample collected shows ancient Mars could have supported living microbes. Photo Credit: (NASA/Carla Cioffi)

  12. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  13. Rock Bites into 'Bounce'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panoramic camera image from the Mars Exploration Rover Opportunity features the 6.44 millimeter (0.25 inch) deep hole ground into the rock dubbed 'Bounce' by the rover's rock abrasion tool. The tool took 2 hours and 15 minutes to grind the hole on sol 66 of the rover's journey. A combination of limited solar power and the rock's jagged texture led the rock abrasion tool team to set very aggressive grinding parameters to ensure that the end result was a full circle, suitable for a thorough read from the rover's spectrometers.

    Bounce's markedly different appearance (when compared to the rocks that were previously examined in the Eagle Crater outcrop) made it a natural target for rover research. In order to achieve an ideal position from which to grind into the rock, Opportunity moved in very close with its right wheel next to Bounce. In this image, the panoramic camera on the rover's mast is looking down, catching the tip of the solar panel which partially blocks the full circle ground by the rock abrasion tool.

    The outer ring consists of the cuttings from the rock, pushed out by the brushes on the grinding instrument. The dark impression at the top of the outer circle was caused by the instrument's contact mechanism which serves to stabilize it while grinding.

  14. Odyssey/White Rock

    NASA Image and Video Library

    2002-10-01

    These Mars Odyssey images show the White Rock feature on Mars in both infrared left and visible right wavelengths. White Rock is the unofficial name for this landform that was first observed during NASA Mariner 9 mission in the early 1970.

  15. Rock Cycle Roulette.

    ERIC Educational Resources Information Center

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  16. Welcome to Rock Day

    ERIC Educational Resources Information Center

    Varelas, Maria; Benhart, Jeaneen

    2004-01-01

    At the beginning of the school year, the authors, a first-grade teacher and a teacher educator, worked together to "spice up" the first-grade science curriculum. The teacher had taught the unit Rocks, Sand, and Soil several times, conducting hands-on explorations and using books to help students learn about properties of rocks, but she felt the…

  17. Welcome to Rock Day

    ERIC Educational Resources Information Center

    Varelas, Maria; Benhart, Jeaneen

    2004-01-01

    At the beginning of the school year, the authors, a first-grade teacher and a teacher educator, worked together to "spice up" the first-grade science curriculum. The teacher had taught the unit Rocks, Sand, and Soil several times, conducting hands-on explorations and using books to help students learn about properties of rocks, but she felt the…

  18. Mars Rock Analysis Briefing

    NASA Image and Video Library

    2013-03-12

    David Blake, principal investigator for Curiosity's Chemistry and Mineralogy investigation at NASA's Ames Research Center in Calif., speaks at a news conference presenting findings of the Curiosity rover's analysis of the first sample of rock powder collected on Mars, Tuesday, March 12, 2013 in Washington. The rock sample collected shows ancient Mars could have supported living microbes. Photo Credit: (NASA/Carla Cioffi)

  19. Chocolate Hills Rock

    NASA Image and Video Library

    2010-02-16

    This false-color image, taken by the panoramic camera on NASA rover Opportunity, shows the rock Chocolate Hills, perched on the rim of the 10-meter 33-foot wide Concepcion crater. This rock has a thick, dark-colored coating resembling chocolate.

  20. Rock Cycle Roulette.

    ERIC Educational Resources Information Center

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  1. Rock Bites into 'Bounce'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panoramic camera image from the Mars Exploration Rover Opportunity features the 6.44 millimeter (0.25 inch) deep hole ground into the rock dubbed 'Bounce' by the rover's rock abrasion tool. The tool took 2 hours and 15 minutes to grind the hole on sol 66 of the rover's journey. A combination of limited solar power and the rock's jagged texture led the rock abrasion tool team to set very aggressive grinding parameters to ensure that the end result was a full circle, suitable for a thorough read from the rover's spectrometers.

    Bounce's markedly different appearance (when compared to the rocks that were previously examined in the Eagle Crater outcrop) made it a natural target for rover research. In order to achieve an ideal position from which to grind into the rock, Opportunity moved in very close with its right wheel next to Bounce. In this image, the panoramic camera on the rover's mast is looking down, catching the tip of the solar panel which partially blocks the full circle ground by the rock abrasion tool.

    The outer ring consists of the cuttings from the rock, pushed out by the brushes on the grinding instrument. The dark impression at the top of the outer circle was caused by the instrument's contact mechanism which serves to stabilize it while grinding.

  2. Bounce Rock Snapshot

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1 This Mars Exploration Rover Opportunity panoramic camera image shows 'Bounce Rock,' a rock the airbag-packaged rover struck while rolling to a stop on January 24, 2004. This is the largest rock for as far as the eye can see, approximately 35 centimeters (14 inches) long and 10 centimeters (4 inches) high. There appears to be a dusty coating on the top of parts of the rock, which may have been broken when it was struck by the airbags. The rock was about 5 meters (16 feet) from the rover when this image was obtained. This is an enhanced color composite image from sol 36 of the rover's journey, generated using the camera's L2 (750 nanometer), L5 (530 nanometer), and L6 (480 nanometer) filters.

    Bounce Rock Spectra Figure 1 above is a plot of panoramic camera spectra extracted from three different regions on the rock dubbed 'Bounce.' The yellow spectrum is from the yellow box in the image on the left, from the dusty top part of the rock. The spectrum is dominated by the signature of oxidized 'ferric' iron (Fe3+) like that seen in the classic Martian dust. The red spectrum is from the darker Meridiani Planum soils that were disturbed by the airbag when it bounced near the rock. That spectrum is also dominated by ferric iron, though the reflectivity is lower. Scientists speculate that this may be because the grains are coarser in these soils compared to the dust. The green spectrum, which is from the right side of the rock, shows a strong drop in the infrared reflectance that is unlike any other rock yet seen at Meridiani Planum or Gusev Crater. This spectral signature is typical of un-oxidized 'ferrous' iron (Fe2+) in the rock, perhaps related to the presence of volcanic minerals like olivine or pyroxene. The possibility that this may be a basaltic rock that is distinctly different from the rocks seen in the Eagle Crater outcrop is being intensively explored using the rover's other instruments.

  3. Layered Rocks in Crater

    NASA Technical Reports Server (NTRS)

    2004-01-01

    19 June 2004 Exposures of layered, sedimentary rock are common on Mars. From the rock outcrops examined by the Mars Exploration Rover, Opportunity, in Meridiani Planum to the sequence in Gale Crater's central mound that is twice the thickness of of the sedimentary rocks exposed by Arizona's Grand Canyon, Mars presents a world of sediment to study. This unusual example, imaged by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), shows eroded layer outcrops in a crater in Terra Tyrrhena near 15.4oS, 270.5oW. Sedimentary rocks provide a record of past climates and events. Perhaps someday the story told by the rocks in this image will be known via careful field work. The image covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from the left.

  4. Olokele rock avalanche, island of Kauai, Hawaii.

    USGS Publications Warehouse

    Jones, B.L.; Chinn, S.S.W.; Brice, J.C.

    1984-01-01

    In October 1981 a mass of rock and soil having an estimated volume of 500 000 m3 fell as a rock fall-avalanche from a steep slope 800 m high near the head of Olokele Canyon. Boulders were launched into the air from a bench on the slope for a downstream distance of about 850 m. The velocity of the avalanche was rapidly diminished by impact against the valley sides, and it became a muddy debris flow that traveled 4.6 km downstream, severely eroding the valley sides. The volume of debris deposited on the canyon bottom is estimated to be 2 500 000 m3, or about four times the volume derived from the slope. -from Authors

  5. Injury patterns in recreational rock climbers.

    PubMed

    Rooks, M D; Johnston, R B; Ensor, C D; McIntosh, B; James, S

    1995-01-01

    We studied 39 recreational rock climbers to determine the incidence and pattern of injuries sustained in the sport at their level. Eleven climbers (26%), who climbed beyond the sport level, had sustained a major injury from a fall. Thirty-five climbers (89%) sustained at least one significant injury. Fifty percent of the injuries involved the hand or wrist. Only seven climbers (19%) had evidence of a digital pulley injury (climber's finger). Four climbers (11%) had evidence of a carpal tunnel syndrome. Twenty climbers (50%) had tendinitis in an upper extremity on physical examination.

  6. Monitoring and Evaluation of Smolt Migration in the Columbia Basin, Volume XIV; Evaluation of 2006 Prediction of the Run-Timing of Wild and Hatchery-Reared Salmon and Steelhead at Rock Island, Lower Granite, McNary, John Day and Bonneville Dams using Program Real Time, Technical Report 2006.

    SciTech Connect

    Griswold, Jim

    2007-01-01

    Program RealTime provided monitoring and forecasting of the 2006 inseason outmigrations via the internet for 32 PIT-tagged stocks of wild ESU chinook salmon and steelhead to Lower Granite and/or McNary dams, one PIT-tagged hatchery-reared ESU of sockeye salmon to Lower Granite Dam, and 20 passage-indexed runs-at-large, five each to Rock Island, McNary, John Day, and Bonneville Dams. Twenty-four stocks are of wild yearling chinook salmon which were captured, PIT-tagged, and released at sites above Lower Granite Dam in 2006, and have at least one year's historical migration data previous to the 2006 migration. These stocks originate in drainages of the Salmon, Grande Ronde and Clearwater Rivers, all tributaries to the Snake River, and are subsequently detected through the tag identification and monitored at Lower Granite Dam. In addition, seven wild PIT-tagged runs-at-large of Snake or Upper Columbia River ESU salmon and steelhead were monitored at McNary Dam. Three wild PIT-tagged runs-at-large were monitored at Lower Granite Dam, consisting of the yearling and subyearling chinook salmon and the steelhead trout runs. The hatchery-reared PIT-tagged sockeye salmon stock from Redfish Lake was monitored outmigrating through Lower Granite Dam. Passage-indexed stocks (stocks monitored by FPC passage indices) included combined wild and hatchery runs-at-large of subyearling and yearling chinook, coho, and sockeye salmon, and steelhead trout forecasted to Rock Island, McNary, John Day, and Bonneville Dams.

  7. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume XV : Evaluation of the 2007 Predictions of the Run-Timing of Wild and Hatchery-Reared Salmon and Steelhead Smolts to Rock Island, Lower Granite, McNary, John Day, and Bonneville Dams using Program RealTime.

    SciTech Connect

    Griswold, Jim; Townsend, Richard L.; Skalski, John R.

    2008-12-01

    Program RealTime provided monitoring and forecasting of the 2007 inseason outmigrations via the internet for 26 PIT-tagged stocks of wild ESU Chinook salmon and steelhead to Lower Granite and/or McNary dams, one PIT-tagged hatchery-reared ESU of sockeye salmon to Lower Granite Dam, one PIT-tagged wild stock of sockeye salmon to McNary Dam, and 20 passage-indexed runs-at-large, five each to Rock Island, McNary, John Day, and Bonneville dams. Nineteen stocks are of wild yearling Chinook salmon which were captured, PIT-tagged, and released at sites above Lower Granite Dam in 2007 and have at least one year's historical migration data previous to the 2007 migration. These stocks originate in 19 tributaries of the Salmon, Grande Ronde and Clearwater Rivers, all tributaries to the Snake River, and are subsequently detected through tag identification and monitored at Lower Granite Dam. Seven wild PIT-tagged runs-at-large of Snake or Upper Columbia River ESU salmon and steelhead were monitored at McNary Dam. Three wild PIT-tagged runs-at-large were monitored at Lower Granite Dam, consisting of the yearling and subyearling Chinook salmon and the steelhead runs. The hatchery-reared PIT-tagged sockeye salmon stock from Redfish Lake was monitored outmigrating through Lower Granite Dam. Passage-indexed stocks (stocks monitored by FPC passage indices) included combined wild and hatchery runs-at-large of subyearling and yearling Chinook, coho, and sockeye salmon, and steelhead forecasted to Rock Island, McNary, John Day, and Bonneville dams.

  8. Rocks From Space: A Historical Perspective

    NASA Astrophysics Data System (ADS)

    Yeomans, Donald K.

    2013-10-01

    The notion that rocks could fall to Earth from space was not seriously considered until the early nineteenth century. The impact origin of the lunar craters reached a scientific consensus only in the mid twentieth century and a wide understanding that the Earth’s neighborhood is crowded with millions of near-Earth asteroids that could cause impact damage to Earth is less than a few decades old. In the late seventeenth century, even such notable scientists as Robert Hooke and Isaac Newton ruled out the existence of small bodies in space. In 1794, the German physicist and father of acoustics Ernst F.F. Chladni published a short list of fireball events and effectively argued that these events and the meteorites they dropped could not have been atmospheric and were likely due to cosmic rocks entering the Earth’s atmosphere. In 1802 the British chemist Edward Charles Howard showed that several meteoritic stones had similar chemical compositions and that nickel, which is seldom present in terrestrial rocks except in trace amounts, was common to all of them. These two pivotal works, along with a number of early nineteenth century falls, slowly strengthened the notion that fireball events and the stones they dropped were of celestial, rather than atmospheric, origin. Even so, it was well into the mid twentieth century before Meteor Crater in particular and the obvious lunar craters in general were widely considered as impact phenomena rather than being due to volcanic eruptions or steam generated explosions. It seems that despite Mother Nature’s best attempts to point out the importance of impact events in the solar system and the existence of a vast population of near-Earth asteroids, much of the scientific community reached these viewpoints rather late. Likely reasons for this slow acceptance of rocks from space will be discussed.

  9. After the Fall: A Conflict Management Program to Foster Open Society

    ERIC Educational Resources Information Center

    Shapiro, Daniel L.

    2004-01-01

    The fall of the Berlin Wall rocked the sociopolitical equilibrium of eastern and central Europe. Communism lost its grip over much of Europe. The USSR, Yugoslavia, and Czechoslovakia divided along ethnic, religious, and historical lines. Ethnopolitical tensions surfaced across the region, and in Yugoslavia, tensions combusted. Whereas democracy…

  10. After the Fall: A Conflict Management Program to Foster Open Society

    ERIC Educational Resources Information Center

    Shapiro, Daniel L.

    2004-01-01

    The fall of the Berlin Wall rocked the sociopolitical equilibrium of eastern and central Europe. Communism lost its grip over much of Europe. The USSR, Yugoslavia, and Czechoslovakia divided along ethnic, religious, and historical lines. Ethnopolitical tensions surfaced across the region, and in Yugoslavia, tensions combusted. Whereas democracy…

  11. Our World: The Rock Cycle

    NASA Image and Video Library

    Find out how rocks brought to Earth by the Apollo astronauts have helped NASA learn more about the rock cycle. Compare igneous, sedimentary and metamorphic rocks found on Earth to three types of ro...

  12. The "Aachen fall prevention App" - a Smartphone application app for the self-assessment of elderly patients at risk for ground level falls.

    PubMed

    Rasche, Peter; Mertens, Alexander; Bröhl, Christina; Theis, Sabine; Seinsch, Tobias; Wille, Matthias; Pape, Hans-Christoph; Knobe, Matthias

    2017-01-01

    Fall incidents are a major problem for patients and healthcare. The "Aachen Fall Prevention App" (AFPA) represents the first mobile Health (mHealth) application (app) empowering older patients (persons 50+ years) to self-assess and monitor their individual fall risk. Self-assessment is based on the "Aachen Fall Prevention Scale," which consists of three steps. First, patients answer ten standardized yes-no questions (positive criterion ≥ 5 "Yes" responses). Second, a ten-second test of free standing without compensatory movement is performed (positive criterion: compensatory movement). Finally, during the third step, patients rate their subjective fall risk on a 10-point Likert scale, based on the results of steps one and two. The purpose of this app is (1) to offer a low-threshold service through which individuals can independently monitor their individual fall risk and (2) to collect data about how a patient-centered mHealth app for fall risk assessment is used in the field. The results represent the first year of an ongoing field study. From December 2015 to December 2016, 197 persons downloaded the AFPA (iOS(™) and Android(™); free of charge). N = 111 of these persons voluntarily shared their data and thereby participated in the field study. Data from a final number of n = 79 persons were analyzed due to exclusion criteria (age, missing objective fall risk, missing self-assessment). The objective fall risk and the self-assessed subjective risk measured by the AFPA showed a significant positive relationship. The "Aachen Fall Prevention App" (AFPA) is an mHealth app released for iOS and Android. This field study revealed the AFPA as a promising tool to raise older adults' awareness of their individual fall risk by means of a low-threshold patient-driven fall risk assessment tool.

  13. Wearable technology and ECG processing for fall risk assessment, prevention and detection.

    PubMed

    Melillo, Paolo; Castaldo, Rossana; Sannino, Giovanna; Orrico, Ada; de Pietro, Giuseppe; Pecchia, Leandro

    2015-01-01

    Falls represent one of the most common causes of injury-related morbidity and mortality in later life. Subjects with cardiovascular disorders (e.g., related to autonomic dysfunctions and postural hypotension) are at higher risk of falling. Autonomic dysfunctions increasing the risk of falling in the short and mid-term could be assessed by Heart Rate Variability (HRV) extracted by electrocardiograph (ECG). We developed three trials for assessing the usefulness of ECG monitoring using wearable devices for: risk assessment of falling in the next few weeks; prevention of imminent falls due to standing hypotension; and fall detection. Statistical and data-mining methods are adopted to develop classification and regression models, validated with the cross-validation approach. The first classifier based on HRV features enabled to identify future fallers among hypertensive patients with an accuracy of 72% (sensitivity: 51.1%, specificity: 80.2%). The regression model to predict falls due to orthostatic dropdown from HRV recorded before standing achieved an overall accuracy of 80% (sensitivity: 92%, specificity: 90%). Finally, the classifier to detect simulated falls using ECG achieved an accuracy of 77.3% (sensitivity: 81.8%, specificity: 72.7%). The evidence from these three studies showed that ECG monitoring and processing could achieve satisfactory performances compared to other system for risk assessment, fall prevention and detection. This is interesting as differently from other technologies actually employed to prevent falls, ECG is recommended for many other pathologies of later life and is more accepted by senior citizens.

  14. 1983 AGU Fall Meeting Report

    NASA Astrophysics Data System (ADS)

    In only 5 days the AGU 1983 Fall Meeting in San Francisco accommodated more than 3100 attendees and more than 2100 papers. Each of the special, all-Union sessions attracted crowds of close to 1100 persons. Except for the 1982 Fall Meeting, which covered 8 days and included the American Society of Limnology and Oceanography (ASLO) Winter Meeting, 1983's was the largest AGU Fall Meeting ever.The large number of presentaions at the 1983 meeting was handled efficiently by assigning more than 30% of the papers to poster sessions, which were to many participants the highlight of the meeting. Poster presentations are becoming extremely good, and some of the more spirited sessions make many oral presentations seem pale in comparison. The sight of some of the world's leading geophysicists chatting over a poster paper with a student attested to one of the advantages of this type of presentation.

  15. [Accidental falls in the elderly].

    PubMed

    Heinimann, Niklas B; Kressig, Reto W

    2014-06-18

    Falls in the elderly are common with consecutive high mortality and morbidity. Recent consecutive data focus on identification and therapy of intrinsic risk factors. Sarcopenia, imbalance and gait disorders represent the major risk factors. Sarcopenia is caused by a disequilibrium of protein synthesis and breakdown, probably in consequence of age-related changes in protein metabolism. Protein supplements in combination with strength training shows the best benefit. Disorders in balance and gait are caused by age-related or pathologic changes in a complex regulation system of gait. The individual fall risk correlates with the gait variability and even increases with bad dual task performance. Activities with high requirements of attention and body awareness are the most effective prevention for falls in the elderly (-50%).

  16. [Intelligent videosurveillance and falls detection: Perceptions of professionals and managers].

    PubMed

    Lapierre, Nolwenn; Carpentier, Isabelle; St-Arnaud, Alain; Ducharme, Francine; Meunier, Jean; Jobidon, Mireille; Rousseau, Jacqueline

    2016-02-01

    Gerontechnologies can be used to detect accidental falls. However, existing systems do not entirely meet users' expectations. Our team developed an intelligent video-monitoring systems to fill these gaps. Authors advocate consulting potential users at the early stages of the design of gerontechnologies and integrating their suggestions. This study aims to explore health care workers' opinion regarding the intelligent video monitoring to detect falls by older adults living at home. This qualitative study explored the opinions of 31 participants using focus groups. Transcripts were analyzed using predetermined codes based on the competence model. Participants reported several advantages for using the intelligent video monitoring and provided suggestions for improving its use. The participants' suggestions and comments will help to improve the system and match it to users' needs. © CAOT 2015.

  17. 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.

  18. A Piece of Paper Falling Faster than Free Fall

    ERIC Educational Resources Information Center

    Vera, F.; Rivera, R.

    2011-01-01

    We report a simple experiment that clearly demonstrates a common error in the explanation of the classic experiment where a small piece of paper is put over a book and the system is let fall. This classic demonstration is used in introductory physics courses to show that after eliminating the friction force with the air, the piece of paper falls…

  19. A Piece of Paper Falling Faster than Free Fall

    ERIC Educational Resources Information Center

    Vera, F.; Rivera, R.

    2011-01-01

    We report a simple experiment that clearly demonstrates a common error in the explanation of the classic experiment where a small piece of paper is put over a book and the system is let fall. This classic demonstration is used in introductory physics courses to show that after eliminating the friction force with the air, the piece of paper falls…

  20. BURDEN FALLS ROADLESS AREA, ILLINOIS.

    USGS Publications Warehouse

    Klasner, John S.; Thompson, Robert M.

    1984-01-01

    The Burden Falls Roadless Area lies in the Shawnee National Forest of southern Illinois, about 5 mi west of the western edge of the Illinois-Kentucky fluorspar district. Geologic mapping and geochemical surveys indicate that the area has little promise for the occurrence of fluorspar and associated minerals; other special studies also indicate little promise for oil and gas and construction materials. Traces of gold and silver were detected in some geochemical samples but follow-up studies indicate little promise for the occurrence of resources of these metals within the Burden Falls Roadless Area.