Tsunamis generated by landslides and volcanic island collapses account for some of the most catastrophic events, and the largest recorded wave runup was generated by a supercritical landslide impact in Lituya Bay, Alaska. Unfortunately field data from these types of events is very limited, consisting of rare field measurements of landslide scarp, landslide deposit and tsunami runup, as well as eyewitness accounts. Critically important field data related to the landslide motion and tsunami evolution are lacking. Source and runup scenarios based on real world events are physically modeled in the three- dimensional NEES tsunami wave basin at Oregon State University. A unique pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The LTG consists of a sliding box filled with up to 1,350 kg of naturally rounded river gravel or cobbles which is accelerated by means of four pneumatic pistons down the 2H: 1V slope, launching the granular landslide towards the water at velocities of up to 6 m/s. Topographical and bathymetric features can greatly affect wave characteristics and runup heights. Landslide generated tsunamis were studied in different topographic and bathymetric configurations: basin-wide propagation and runup, a narrow fjord and curved headland configurations, and a conical island setting simulating landslides off an island or a volcanic flank collapse. Water surface elevations were measured using an array of resistance wave gauges. The granular landslide width, thickness and front velocity were measured using above and underwater cameras. Wave runup was measured with a combination of resistance wave gauges and overlapping video recordings calibrated along the slope. The effects from lateral hill slope curvature are analyzed: the leading wave crest amplitude generated on a planar hill slope is 3% larger on average than the leading wave crest generated on a convex conical hill slope, while the leading wave trough and second wave crest amplitudes are smaller. The fjord scenario traps the wave energy resulting in the average maximum runup being 10% larger than in the curved headland scenario, which allows some wave energy to leak into the open basin. Between 1-24% of the landslide kinetic energy is transferred in to the wave train. Cobble landslides transfer on average 43% more kinetic energy into the wave train than the gravel landslide. Predictive equations for the offshore and laterally propagating wave and runup amplitudes, periods, celerities and lengths are derived, which allow an initial rapid tsunami hazard assessment. Finally, the predictive wave and runup equations are applied to the 2007 field event in Chehalis Lake, Canada.

Thesis (M. Sc.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

The 1946 M7.3 Ancash earthquake triggered a large number of landslides in an epicentral area along the continental divide in the Andes of Peru. Reconnaissance reports by Silgado (1947, 1951), Heim (1949) and Rüegg (1950) published shortly after the earthquake describe some of the landslides, but lack any detailed documentation. A review of literature, field traverses, aerial photograph interpretation and GIS mapping, identified 45 landslides inferred to have been triggered by the event. The cumulative volume-frequency plot shows a strong power law relation, similar in form to that derived for landslides triggered by the 1994 Northridge earthquake (Harp and Jibson, 1995). Data for the Ancash earthquake plots near the regression line calculated by Keefer (1994), and modified by Malamud et al. (2004), for earthquake moment magnitude vs. total volume moved by landslides during the earthquake. A denudation (average surface lowering) of 76 mm and a denudation rate of 0.00585 mm/yr was estimated for the area over which the earthquake-triggered landslides occurred. Rock avalanches constituted 83% of the landslides which involved Cretaceous limestones interbedded with shales. Rock slope failures were common on slopes with a southwest aspect, an orientation corresponding to the regional dip direction of major planar structures in the epicentral area. In valleys oriented transverse to the NW-SE structural trend of the epicentral area, south-westerly dipping bedding planes combined with orthogonal joint sets to form numerous wedge failures. Three rock avalanches were analysed using conventional wedge failure criteria. Two of the rock avalanches which did not satisfy conventional criteria were utilized to develop a new criteria, i.e. stepped wedge criteria. Stepped wedge failure involves wedge movement along a stepped line of intersection formed by a nearly-vertical discontinuity, striking roughly parallel to the slope, and the conventional line of intersection formed by the bedding and orthogonal joint set. The nearly-vertical discontinuity forms the essential backscarp needed to facilitate stepped wedge failure. Additional characteristics of stepped wedge failure were also distinguished based on the wedge failures studied in the epicentral area of the 1946 Ancash earthquake.

The 1946 M7.3 Ancash earthquake triggered a large number of landslides in an epicentral area along the continental divide in the Andes of Peru. Reconnaissance reports by Silgado (1947, 1951), Heim (1949) and Rüegg (1950) published shortly after the earthquake describe some of the landslides, but lack any detailed documentation. A review of literature, field traverses, aerial photograph interpretation and GIS mapping, identified 45 landslides inferred to have been triggered by the event. The cumulative volume-frequency plot shows a strong power law relation, similar in form to that derived for landslides triggered by the 1994 Northridge earthquake (Harp and Jibson, 1995). Data for the Ancash earthquake plots near the regression line calculated by Keefer (1994), and modified by Malamud et al. (2004), for earthquake moment magnitude vs. total volume moved by landslides during the earthquake. A denudation (average surface lowering) of 76 mm and a denudation rate of 0.00585 mm/yr was estimated for the area over which the earthquake-triggered landslides occurred. Rock avalanches constituted 83% of the landslides which involved Cretaceous limestones interbedded with shales. Rock slope failures were common on slopes with a southwest aspect, an orientation corresponding to the regional dip direction of major planar structures in the epicentral area. In valleys oriented transverse to the NW-SE structural trend of the epicentral area, south-westerly dipping bedding planes combined with orthogonal joint sets to form numerous wedge failures. Three rock avalanches were analysed using conventional wedge failure criteria. Two of the rock avalanches which did not satisfy conventional criteria were utilized to develop a new criteria, i.e. stepped wedge criteria. Stepped wedge failure involves wedge movement along a stepped line of intersection formed by a nearly-vertical discontinuity, striking roughly parallel to the slope, and the conventional line of intersection formed by the bedding and orthogonal joint set. The nearly-vertical discontinuity forms the essential backscarp needed to facilitate stepped wedge failure. Additional characteristics of stepped wedge failure were also distinguished based on the wedge failures studied in the epicentral area of the 1946 Ancash earthquake.

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 177-185). Also available for download via the World Wide Web; free to University of Oregon users.

The Ottawa/Gatineau region has significant deposits of sensitive glacial marine clay. As these deposits have risen due to isostatic rebound, these materials have been incised by various watercourses, carving river valleys throughout the region. The slopes of these river banks are susceptible to retrogressive slides with significant travel distances. A novel method of monitoring changes in these landslides has been developed and is explained in this thesis. Using a tethered blimp as an aerial photo platform, high resolution digital elevations models (DEM) with accuracies of ±0.49m on vegetated slopes have been created using photogrammetry. These DEMs have been created for a several photos sets taken over time. This allows changes over time to be monitored. The use of ground control points (GCP) allows for the complete three dimensional movement of discrete points to be monitored over time. The photogrammetric DEM have been compared to similar DEM derived from LiDAR surveying. By complimenting these surveys with historical aerial photos it is possible to develop better models of landslide failure processes, which will ultimately provide better predictions of movements and failure. When movements and failures can accurately be predicted it will then be possible to better manage the risk associated with these landslides events. / Thesis (Master, Civil Engineering) -- Queen's University, 2012-01-30 16:20:27.13

Computer simulation of rockfalls has been widely used in rockfall analysis in recent years, and the coefficient of restitution is an important parameter input that is difficult to determine. Aimed at finding an easy solution to this problem, three stages of laboratory and field tests have been carried out. Rockfall trajectory analysis at a specific site has been done as an application to verify the method developed. In the first stage of laboratory testing, quasi-spherical rock "'balls" made from different rock samples were dropped from 1 m onto polished rock slabs that were clamped on a concrete deck, which can be set to different slope angles. A high-speed video camera was used to record the impact processes, and normal and tangential coefficients of restitution were calculated from the video records. The results show a linear relationship between the normal restitution coefficient and the Schmidt hammer numbers of both the rock slabs and the falling rock "balls", and the slope angle. An empirical equation was then established to calculate the normal coefficient of restitution from those three parameters. However, the correlations between the tangential coefficient of restitution and the above parameters are poor, indicating that the tangential coefficient of restitution is not adequately determined by such rock properties. The second stage of laboratory testing was under more practical conditions. Three different rough rock blocks were used as rock slopes. Angular rock boulders were dropped from different heights onto the rock blocks, and a rock "ball" was also used to make a comparison. The results show that the normal coefficients of restitution from impacts of angular rocks are much smaller than those of rock "'balls", and have a linear correlation with those calculated from the empirical equation obtained by the earlier test. Tests on beds of gravel, soil, rock fragments and sand have also been carried out to obtain the coefficients of restitution of those materials. Finally, field tests have been carried out at a quarry site in Lyttelton Basalt rock boulders of about 0.3 m in diameter were dropped from about 4 m onto rock and debris slopes using an excavator. The values of restitution coefficients obtained are similar to those from laboratory tests but larger than those calculated from the empirical equations due to the effect of weathering and surface roughness of rocks in the field on the Schmidt hammer measurement. Forty basalt boulders were then rolled down a bench slope of about 16 m, three cameras were used to record the rockfall processes. Two different rockfall simulation programs (CRSP and RocFall) were used to simulate the rockfall processes. The simulated bounce heights and velocities from CRSP are close the field trial, while those from RocFall are smaller than the field results. Comprehensive rockfall analysis has been carried out for the Marine apartments, Sumner, where a steep cliff of 35-45 m represents potential rockfall hazards to a car park and proposed buildings at the base. Site investigation, rockfall simulation and risk assessment have been carried out for the site. The results show that without any protection measures, a majority of rocks from the cliff face reach the edge of the car park. The probability of an accident at the car park is moderate (1 in 195 years), while the probability of fatality at the car park is low (8.69* 10-6) and acceptable under the proposed risk criteria for "Major Civil Engineering Projects".

Thesis (doctoral)--University of London, 2001. / BLDSC reference no.: DX218627.

Earthquake and submarine mass failure are the most frequent causes of tsunami waves. While the process of the tsunami generation by earthquakes is reasonably well understood, the generation of tsunami waves during submarine mass failure is not. Estimates of the energy released during a tsunamigenic earthquake and respective tsunami wave draw a clear picture of the efficiency of the tsunami-generating process. However for submarine landslides, this is not as straightforward because the generation process has never been recorded in nature making energy inferences very difficult. Hence the efficiency of submarine landslide as tsunami generators is yet to be conclusively determined. As the result of this uncertainty, different equations, derived from experimental data or theory, result in leading-wave amplitude that vary over 6 orders of magnitude for the same initial slide conditions. To arrive at more robust estimates of the leading-wave characteristics and associated runup, the spatiotemporal dynamics of the coupling between the slide body and water column needs to be investigated. The duration the water surface deformation is coupled with the slide motion is an essential question to shed light on the energy transfer. A parametric study is conducted with the state of-the-art hydrocode iSALE in order to shed light on this complex geophysical event. The mass, viscosity, and depth of submergence are the particular slide parameters varied and their relationship to runup and decoupling time is analyzed.

Thesis (M.E.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 178-189). Also available via the World Wide Web.