Constraining parameter uncertainty in modeling debris-flow initiation during the September 2013 Colorado Front Range storm

The occurrence of debris flows during the September 2013 northern Colorado floods took the emergency management community by surprise. The September 2013 debris flows in the Colorado Front Range initiated from shallow landslides in colluvium. Most occurred on south- and east-facing slopes on the walls of steep canyons in crystalline rocks and on sedimentary hogbacks. Previous studies showed that most debris flows occurred in areas of high storm-total rainfall and that strength added by tree roots accounts for the low number of landslides in densely forested areas. Given the lack of rainfall thresholds for debris flow occurrence in northern Colorado, we want to parameterize a numerical model to assess potential for debris flows in advance of heavy rainfall. Natural Resources Conservation Service (NRCS) soil mapping of the area, supplemented by laboratory testing and field measurements, indicates that soil textures and hydraulic properties of landslide source materials vary considerably over the study area. As a step toward modeling storm response, available soil and geologic mapping have been interpreted to define zones of relatively homogeneous properties. A new, simplified modeling approach for evaluating model input parameters in the context of slope and depth of observed debris flow source areas and recorded debris-flow inducing rainfall helps narrow the range of possible parameters to those most likely to produce model results consistent with observed debris flow initiation. Initial results have narrowed the strength parameters to about one third of possible combinations of cohesion and internal friction angle and narrowed hydraulic conductivity to a range spanning slightly more than one order of magnitude

Comparison of Three-Dimensional Motion of the Scapula during the Hawkins-Kennedy Test and the Sidelying Sleeper Stretch

Comparison of Three-Dimensional Motion of the Scapula during the Hawkins-Kennedy Test and the Sleeper Stretch. Alyssa S. Buchner, Tami J. Buus, Brittany N. Evans, Kirsten E. Lambert, Lisandra M. Scheevel Advisor: Cort J. Cieminski, PT, PhD, ATR PURPOSE: The Hawkins-Kennedy test is a pain provocation test used to identify shoulder pathology. With this test, it is hypothesized the scapula tips anteriorly and compresses soft tissue structures of the shoulder, causing pain. A common intervention for this type of shoulder pathology is the sidelying sleeper stretch. Although the glenohumeral (GH) joint is in the same anatomical position for both conditions, the sleeper stretch does not typically provoke pain. In the sidelying position the scapula was stabilized by the subject’s body weight, theoretically limiting the amount of anterior tipping. Currently, there is no research investigating the scapular arthrokinematics in both conditions. The purpose of this study is to measure scapular tipping accompanying shoulder internal rotation (IR) range of motion (ROM) in the sidelying sleeper stretch position compared to the Hawkins-Kennedy test position. METHODS: While passive moving from full shoulder external to internal rotation, scapular tipping and GH IR were measured in the Hawkins-Kennedy and sidelying sleeper stretch using three-dimensional motion analysis, on the dominant shoulder of 30 healthy subjects (13 male [31.3±13.0 years, 24.6±2.7 BMI] and 17 female [27.4±8.7 years, 23.2±2.3 BMI]). RESULTS: Hawkins-Kennedy GH IR mean was 94.1°±13.2° and sidelying GH IR mean was 71.9°±15.9° (

Carbonate fabric and fold morphology of a drag fold in the Bird Spring Group (Lower Pennsylvanian), in Battleship Wash, Nevada

Thesis (B.S.) in Geology--University of Illinois at Urbana-Champaign, 1979.Includes bibliographical references (leaf 36)Microfiche of typescript. [Urbana, Ill.] : Photographic Services, University of Illinois, U of I Library, [1979]. 2 microfiches (46 frames) : negative. s1979 ilun

Determining crustal velocities of the Ruby Mountains, Nevada using local mine blasts

This study seeks to conduct an active seismic survey of the Ruby Mountains core complex (RMCC), northeastern Nevada, using local mine blasts in conjunction with a passive seismic array. Three nearby mines\u27 daily blasts are recorded by the Ruby Mountains Seismic Experiment, a 50-station array of broadband seismometers designed primarily to record teleseismic events. This study analyzes a perpendicular transect across the southern RMCC, as well as a transect along the range axis. Crustal velocities are calculated using the highest signal-to-noise event rather than from stacked events, stacked results exhibit lowered signal-to-noise ratios. Bulk velocities in the perpendicular transect match closely those of previous studies, with vp=6.0-6.1 km/s and vs=3.3 km/s. The 6.1 km/s bound matches traditional surveys\u27 vp exactly, while the measured vs is slower than a previous study\u27s by 0.1 km/s. No previous studies have been conducted in the same location as the axis-parallel transect. Along the northern part of the transect, in the more metamorphosed part of the range, vp=6.0 km/s and vs=3.3 km/s. Poisson\u27s ratios calculated from vp and vs are consistent with the presence of granulite facies rocks, though the highest grade rocks mapped in the RMCC are amphibolite. More work is needed to identify the Moho reflection, which may ultimately prove impossible. The active refraction survey on passive instrumentation yields reasonable bulk crustal velocities, but low quality data makes producing rigorous results difficult. Results from this study show that data from local blasts can be used to enhance the understanding of shallow geology underneath passive seismic arrays

Carbonate fabric and fold morphology of a drag fold in the Bird Spring Group (Lower Pennsylvanian), in Battleship Wash, Nevada

Thesis (B.S.) in Geology--University of Illinois at Urbana-Champaign, 1979.Includes bibliographical references (leaf 36)Microfiche of typescript. [Urbana, Ill.] : Photographic Services, University of Illinois, U of I Library, [1979]. 2 microfiches (46 frames) : negative. s1979 ilun

Predicting landslide stability, runout, and failure velocity at Cook Lake landslide, Wyoming

Includes bibliographical references.2017 Spring.Proper understanding of risk is predicated on accurate characterization of hazard. Landslide hazards are common, but are difficult to characterize without a full site investigation, which are often unavailable. This thesis develops a framework for obtaining inexpensive field and laboratory data to characterize three major components of landslide hazard: current stability, runout distance (L), and failure velocity. The framework is designed to analyze deep-seated, soil landslides, and is evaluated using data from the Cook Lake, Wyoming landslide. The framework consists of four tools. Two of these are flowcharts that predict both catastrophic runout and velocity. In line with runout predictions, the third tool estimates the ratio of landslide drop height to runout length, H/L, from measurements of planimetric area. The final tool utilizes back analysis and forward modeling to evaluate a slope’s stability and its sensitivity to hydrologic changes, relying on multiple analyzed sections and sensitivity analysis in lieu of detailed subsurface data. The two flowcharts were developed by synthesizing literature about landslide geometry, local topography, and pore-water pressure. The H/L estimation tool correlates the planimetric area of well-characterized landslides to landslide mobility. The stability modeling tool uses fieldwork, direct shear testing, and limit equilibrium analyses to characterize the behavior of the geologic materials. Comparison of the backward model, which evaluated conditions that triggered a 1997 landslide at Cook Lake, to the forward model revealed that portions of the landslide are more unstable than they were in 1997. Estimates of H/L for a future reactivation range from 0.17 to 0.25. The runout flowchart also indicates that the landslide is likely to exhibit H/L > 0.1, though unexpected contractive soil behavior might cause long runout. The velocity flowchart indicates that the landslide is not likely to move faster than 1.8 m/hr. The combination of these slower velocities and shorter runout indicators would allow evacuation of a nearby campground at Cook Lake during a future reactivation. Other similarly vulnerable sites can benefit from these tools