Pseudotachylyte (Frictionite) at the Base of the Arequipa Volcanic Landslide Deposit (Peru): Implications for Emplacement Mechanisms

2000 ◽  
Vol 108 (5) ◽  
pp. 601-611 ◽  
Author(s):  
François Legros ◽  
Jean‐Marie Cantagrel ◽  
Bertrand Devouard
Keyword(s):  
Volcanic Landslide ◽  
Landslide Deposit

THE RABBIT VALLEY SALIENT, A MASSIVE LANDSLIDE DEPOSIT AT THE COLORADO PLATEAU’S WESTERN MARGIN, SOUTH-CENTRAL UTAH

2018 ◽  
Author(s):  
Christopher M. Bailey ◽  
◽  
Zachariah D. Fleming ◽  
Hanna C. Bartram ◽  
Robert F. Biek ◽  
...  
Keyword(s):  
Western Margin ◽  
South Central ◽  
Landslide Deposit

scholarly journals Impact of mapping errors on the reliability of landslide hazard maps

2002 ◽  
Vol 2 (1/2) ◽  
pp. 3-14 ◽  
Author(s):  
F. Ardizzone ◽  
M. Cardinali ◽  
A. Carrara ◽  
F. Guzzetti ◽  
P. Reichenbach
Keyword(s):  
Statistical Modelling ◽  
Landslide Hazard ◽  
Great Effort ◽  
Hazard Maps ◽  
Data Errors ◽  
Inventory Map ◽  
Terrain Unit ◽  
Discriminant Models ◽  
The Impact ◽  
Landslide Deposit

Abstract. Identification and mapping of landslide deposits are an intrinsically difficult and subjective operation that requires a great effort to minimise the inherent uncertainty. For the Staffora Basin, which extends for almost 300 km2 in the northern Apennines, three landslide inventory maps were independently produced by three groups of geomorphologists. In comparing each map with the others, large positional discrepancies arise (in the range of 55–65%). When all three maps are overlain, the locational mismatch of landslide deposit polygons increases to over 80%. To assess the impact of these errors on predictive models of landslide hazard, for the study area discriminant models were built up from the same set of geological-geomorphological factors as predictors, and the occurrence of landslide deposits within each terrain-unit, derived from each inventory map, as dependent variable. The comparison of these models demonstrates that statistical modelling greatly minimises the impact of input data errors which remain, however, a major limitation on the reliability of landslide hazard maps.

Large volcanic landslide and debris avalanche deposit at Meru, Tanzania

Landslides ◽  
2016 ◽  
Vol 14 (3) ◽  
pp. 833-847 ◽  
Author(s):  
A. Delcamp ◽  
M. Kervyn ◽  
M. Benbakkar ◽  
S. Kwelwa ◽  
D. Peter
Keyword(s):  
Debris Avalanche ◽  
Debris Avalanche Deposit ◽  
Volcanic Landslide

Large-scale flume modelling of segregation processes in debris flows

2020 ◽  
Author(s):  
Julia Kimball ◽  
W Andrew Take
Keyword(s):  
Debris Flows ◽  
Large Scale ◽  
Multicomponent Mixture ◽  
Granular Flows ◽  
Particle Sizes ◽  
Deposit Morphology ◽  
Multicomponent Mixtures ◽  
Particle Segregation ◽  
Experimental Strategies ◽  
Landslide Deposit

<p>Debris flows are powerful natural hazards posing risk to life, infrastructure, and property.  Understanding the particle scale interactions in these flows is a key component in the development of models to predict the mobility, distal reach, and hazard posed by a given event. In this study we focus on the process of segregation in debris flows, using a large-scale landslide flume to explore segregation in mixtures of 25 mm, 12 mm, 6 mm, and 3 mm diameter particle sizes. Sample volumes, consisting of a multicomponent mixture of materials, up to 1 m<sup>3</sup> in size are released at the top of a 6.8 m long, 2.1 m wide slope, inclined at 30 degrees to the horizontal to initiate flow. Subsequent analysis is completed to determine the extent of vertical and longitudinal segregation of the post-landslide deposit morphology. A range of experimental strategies are explored to provide quantitative measures of particle segregation. Particle size is identified via image analysis and various techniques are applied for the longitudinal sectioning of the deposit, using measurements of segregation at the sidewall of the transparent flume, contrasted with planes measured from within the centre of the deposit. Further, replicate experiments are shown to quantify the probabilistic variation in segregation for multicomponent mixtures of dry granular flows, as well as initially saturated granular flows, to explore the effect of pore fluid on segregation processes.</p>

scholarly journals Weathering and erosional processes within the landslide deposit of Jarlang (Ganesh Himal), central Nepal

1997 ◽  
Vol 15 ◽  
Author(s):  
C. F. Uhlir ◽  
J. M. Schramm
Keyword(s):  
Mass Wasting ◽  
Rock Falls ◽  
Fine Grained ◽  
Himalayan Orogeny ◽  
Initial Event ◽  
Central Nepal ◽  
Main Scarp ◽  
Triggering Factor ◽  
Augen Gneiss ◽  
Landslide Deposit

Within the southern flanks of the Ganesh Himal in central Nepal, an area of complex landslides lies in the Jarlang area, situated at the southeastern slope of the Ankhu Khola valley. Slow rotational rockslide in deeply weathered micaceous quartzites interlayering with mica schists have destabilized the head scarp composed of augen gneiss. It caused rockslides from the main scarp generating big spread-out landslides. The landslides of Jarlang generated a stratified deposit (> 106 m3) of matrix-poor breccias with thin fine grained shear horizons. The initial event for the biggest gully system in central Nepal was a gravitational slump owing to nine, day heavy rainfall in 1954. The recent processes within these colluvial deposits are torrential gully erosion accompanied by successive rotational and translational slides along the gully margins. The high activity within the Jarlang gully system can be explained by reactivation of the old Jarlang landslide's shear horizons. The slide grew from an original width of 300 m to 1.2 km at present, covering an area of 2.68 km2. The total volumetric loss by 1996 is l.46xl08 ml. The triggering factor for rock slides and rock falls generating big spread out landslides and debris slides and slope undercutting is seismic events due to extremely high uplift of the Himalayan Orogeny. The strong influence of human activities on slope stability and mass wasting as proposed in the Himalayan Environmental Degradation Theory can not be validated.

scholarly journals Evaluation of seismic effects on the landslide deposits of Monte Salta (Eastern Italian Alps) using distinct element method

2007 ◽  
Vol 7 (6) ◽  
pp. 695-701 ◽  
Author(s):  
G. Marcato ◽  
K. Fujisawa ◽  
M. Mantovani ◽  
A. Pasuto ◽  
S. Silvano ◽  
...  
Keyword(s):  
Seismic Waves ◽  
Fractured Rock ◽  
Distinct Element ◽  
Vertical Component ◽  
Distinct Element Method ◽  
Cretaceous Rock ◽  
First Case ◽  
Civil Defence ◽  
Landslide Deposit ◽  
Element Method

Abstract. The aim of the paper is to present the modelling of the ground effects of seismic waves on a large debris deposit lying on a steep mountain slope, with particular attention paid to the potential triggering of slope movements. The study site is a mass of 2.5 million m3 rock fall deposit, named "Monte Salta Landslide", located on the northern slope of the Vajont valley, at the border between Veneto and Friuli Venezia Giulia regions in north-eastern Italy. Several historical landslide events were reported in the area in the past, first one dating back to the 17th century. The landslide deposit completely mantles the slope with a thick cover of rock blocks. The Mt. Salta landslide is conditioned by the presence of Mt. Borgà regional thrust, which uplifts Jurassic limestone on the top of Cretaceous rock units. Above the thrust zone, folded and highly fractured rock mass dips steeply towards the slope free face, producing highly unstable setting. The study area has been classified as high seismic hazard and different vulnerable elements can be affected by the remobilisation of debris, among which a village, a national road and a big quarry that was opened, with the intent to exploit the part of the landslide deposit for construction purposes. In this study, numerical analysis was performed, to simulate the slope behaviour using distinct element method and applying UDEC code. The 2-D models were built on three cross-sections and elasto-plastic behaviour was assumed, both for rock matrix and discontinuities. The earthquake effect was modelled in pseudo-dynamic way, i.e. by magnifying the acceleration and applying also its horizontal component. The expected seismic acceleration in the study area was calculated on the basis of previous studies as equal to 0.28 g. The results proved that the increase of the vertical component alone has a small influence on the deformational behaviour of the system. Hence, the acceleration vector was deviated at 5° and then at 10° from the vertical. A small increment of the displacement was observed in the first case, whereas very large movements occurred in the second. Therefore, it can be concluded that, besides the magnitude of the earthquake, even small seismic waves in horizontal direction could trigger significant movements and therefore hazardous conditions. The modelled scenario should be helpful for planning of the functional countermeasure works and civil defence evacuation plan.

scholarly journals A kinematic model of the Hsiaolin landslide calibrated to the morphology of the landslide deposit

2011 ◽  
Vol 123 (1-2) ◽  
pp. 22-39 ◽  
Author(s):  
Chia-Ming Lo ◽  
Ming-Lang Lin ◽  
Chao-Lung Tang ◽  
Jyr-Ching Hu
Keyword(s):  
Kinematic Model ◽  
Landslide Deposit

Possible explanations on the formative processes of the Tsugaru-Juniko landslide, northern Japan

2020 ◽  
Author(s):  
Ching-Ying Tsou ◽  
Daisuke Higaki ◽  
Kousei Yamabe ◽  
Tomo Kiru ◽  
Takayoshi Sasagawa ◽  
...  
Keyword(s):  
High Resistivity ◽  
High Porosity ◽  
Resistivity Tomography ◽  
Internal Structures ◽  
Radial Cracks ◽  
Irregular Topography ◽  
Pumice Tuff ◽  
Aomori Prefecture ◽  
Landslide Deposit ◽  
Northern Japan

<p>Identification of complex surficial and internal sedimentological characteristics of landslide deposits can provide insights into the emplacement mechanisms of mass movements. In this study, deposits of the Tsugaru-Juniko landslide, which was historically recorded triggered by an earthquake in 1704 (Imamura, 1935), in Aomori Prefecture, Japan were investigated. This landslide extended about 2 km from east to west with a volume of about 10<sup>8</sup> m<sup>3 </sup>(Furuya et al., 1987), of which deposit is represented by irregular topography and several lakes on and around the rim of it. We conducted field geological and geomorphological surveys and made geomorphological and geophysical analyses using a 1-m resolution LiDAR-DEM and 2D electrical resistivity tomography (ERT) measurement (10 m spacing of electrodes) over a 450 m wide landslide deposit. In plain view, the landslide deposit exhibits quite different features between its northern and southern parts, and each shows a clear sequential distribution of various features. At the northern part, the translation zone is characterized by hummocks and debris lobes containing mixtures of poorly sorted, angular, blocky rock debris of andesitic tuff. Prominent features on the debris lobes are debris-flow-ridges with lobate-shaped aprons extending NW to the downslope. In the accumulation zone, slope surface upheavals of compression origin and radial cracks are observed in the front part of the landslide. At the southern part, as compared to those features observed at the northern part, the slope is commonly marked by transverse ridges, oriented NE-SW, with prevalent steep cliffs on both sides, but generally steeper on the east. The ridges are separated from one another by trenches, elongated across the slope. Based on the distributions of these features, possible explanations on the formative processes of the landslide are complex associated with flowing and sliding at northern and southern parts, respectively. However, geological evidences from its internal structures are rare, ERT survey at the northern part of the landslide deposit reveals that up to 30-m-deep high-resistivity anomaly is associated with the landslide deposit, and low-resistivity anomaly with the bedrock consisting of pumice tuff, as also confirmed in the field. This may result from the high porosity of landslide deposit, because the displaced material deposited loosely.</p>

scholarly journals A Surge of Bualtar Glacier, Karakoram Range, Pakistan: A Possible Landslide Trigger

1990 ◽  
Vol 36 (123) ◽  
pp. 159-162 ◽  
Author(s):  
James S. Gardner ◽  
Kenneth Hewitt
Keyword(s):  
Early Summer ◽  
Ablation Zone ◽  
Northern Pakistan ◽  
Hydrological Characteristics ◽  
Order Of Magnitude ◽  
Glacier Ablation ◽  
Landslide Deposit

AbstractBualtar Glacier, Karakoram Range, northern Pakistan, surged during the spring and early summer of 1987. This followed a major episode of three landslides which impacted part of the glacier ablation zone on 30–31 July 1986. In May 1987, surface velocities of 7 m d−1were measured at one profile down-glacier from the landslide deposits, where in 1986 velocities were an order of magnitude less. Surface and hydrological characteristics of the glacier in and down-glacier from the landslide deposit were also indicative of surge-like behavior in 1987, and a return to pre-surge conditions by 1988.

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