Recurrent rock avalanches progressively dismantle mountain ridges in the Longmen Shan, China, most recently in the 2008 Wenchuan earthquake

2021 ◽  
Author(s):  
Janusz Wasowski ◽  
Maurice McSaveney ◽  
Luca Pisanu ◽  
Vincenzo Del Gaudio ◽  
Yan Li ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
Ambient Noise ◽  
Slope Failure ◽  
Mass Movement ◽  
Rock Avalanche ◽  
Ground Vibration ◽  
Source Area ◽  
Slope Failures ◽  
Rock Avalanches ◽  
Beichuan County

<p>Large earthquake-triggered landslides, in particular rock avalanches, can have catastrophic consequences. However, the recognition of slopes prone to such failures remains difficult, because slope-specific seismic response depends on many factors including local topography, landforms, structure and internal geology. We address these issues by exploring the case of a rock avalanche of >3 million m<sup>3</sup> triggered by the 2008 Mw7.9 Wenchuan earthquake in the Longmen Shan range, China. The failure, denominated Yangjia gully rock avalanche, occurred in Beichuan County (Sichuan Province), one of the areas that suffered the highest shaking intensity and death toll caused by co-seismic landsliding. Even though the Wenchuan earthquake produced tens of large (volume >1 million m<sup>3</sup>) rock avalanches, few studies so far have examined the pre-2008 history of the failed slope or reported on the stratigraphic record of mass-movement deposits exposed along local river courses. The presented case of the Yangjia gully rock avalanche shows the importance of such attempts as they provide information on the recurrence of large slope failures and their associated hazards. Our effort stems from recognition, on 2005 satellite imagery, of topography and morphology indicative of a large, apparently pre-historic slope failure and the associated breached landslide dam, both features closely resembling the forms generated in the catastrophic 2008 earthquake. The follow-up reconstruction recognizes an earlier landslide deposit exhumed from beneath the 2008 Yangjia gully rock avalanche by fluvial erosion since May 2008. We infer a seismic trigger also for the pre-2008 rock avalanche based on the following circumstantial evidence: i) the same source area (valley-facing, terminal portion of a flat-topped, elongated mountain ridge) located within one and a half kilometer of the seismically active Beichuan fault; ii) significant directional amplification of ground vibration, sub-parallel to the failed slope direction, detected via ambient noise measurements on the ridge adjacent to the source area of the 2008 rock avalanche and iii) common depositional and textural features of the two landslide deposits. Then, we show how, through consideration of the broader geomorphic and seismo-tectonic contexts, one can gain insight into the spatial and temporal recurrence of catastrophic slope failures  in Beichuan County and elsewhere in the Longmen Shan. This insight, combined with local-scale geologic and geomorphologic knowledge, may guide selection of suspect slopes for reconnaissance, wide-area ambient noise investigation aimed at discriminating their relative susceptibility to co-seismic catastrophic failures. We indicate the feasibility of such investigations through the example of this study, which uses 3-component velocimeters designed to register low amplitude ground vibration.</p>

scholarly journals Monitoring of recent mass movement activity in anthropogenic slopes of the Krušné Hory Mountains (Czech Republic)

2011 ◽  
Vol 11 (5) ◽  
pp. 1463-1473 ◽  
Author(s):  
J. Burda ◽  
L. Žižka ◽  
J. Dohnal
Keyword(s):  
Czech Republic ◽  
Slope Failure ◽  
Water Saturation ◽  
Mass Movement ◽  
Interdisciplinary Approach ◽  
Open Pit ◽  
Mass Movements ◽  
Slope Failures ◽  
The Czech Republic ◽  
Krušné Hory Mountains

Abstract. Recent mass movements currently comprise one of the main morphogenetic processes in the extensive anthropogenic relief of the foreground of the Krušné Hory Mountains in the Czech Republic. These mass movements result in several types of deep-seated slope failures, depending on the type of movement and the water saturation of the landslide material. This paper presents the results of a detailed geomorphic survey and orthophotograph analysis combined with geodetic monitoring data in an area affected by open-pit coal mining. An interdisciplinary approach has enabled an in-depth review of both the dynamics and development of recent slope failures. The article describes deep-seated landslide complex in this part of the foothills of the Krušné Hory Mountains. At the study site, mass movements occur in thick colluvial mantle and weathered Tertiary claystones. The main factors influencing their development include rainfall culminations, groundwater flowing from the valley of Šramnický Brook and former slope failures. All of the slope failures that have occurred here have originated at former slope failure sites.

scholarly journals Evolution of events before and after the 17 June 2017 rock avalanche at Karrat Fjord, West Greenland – a multidisciplinary approach to detecting and locating unstable rock slopes in a remote Arctic area

2020 ◽  
Vol 8 (4) ◽  
pp. 1021-1038
Author(s):  
Kristian Svennevig ◽  
Trine Dahl-Jensen ◽  
Marie Keiding ◽  
John Peter Merryman Boncori ◽  
Tine B. Larsen ◽  
...  
Keyword(s):  
Multidisciplinary Approach ◽  
Rock Slope ◽  
Rock Avalanche ◽  
Rock Slopes ◽  
Slope Failures ◽  
West Greenland ◽  
Arctic Regions ◽  
Rock Avalanches ◽  
Dip Slope ◽  
Unstable Rock

Abstract. The 17 June 2017 rock avalanche in the Karrat Fjord, West Greenland, caused a tsunami that flooded the nearby village of Nuugaatsiaq and killed four people. The disaster was entirely unexpected since no previous records of large rock slope failures were known in the region, and it highlighted the need for better knowledge of potentially hazardous rock slopes in remote Arctic regions. The aim of the paper is to explore our ability to detect and locate unstable rock slopes in remote Arctic regions with difficult access. We test this by examining the case of the 17 June 2017 Karrat rock avalanche. The workflow we apply is based on a multidisciplinary analysis of freely available data comprising seismological records, Sentinel-1 spaceborne synthetic-aperture radar (SAR) data, and Landsat and Sentinel-2 optical satellite imagery, ground-truthed with limited fieldwork. Using this workflow enables us to reconstruct a timeline of rock slope failures on the coastal slope here collectively termed the Karrat Landslide Complex. Our analyses show that at least three recent rock avalanches occurred in the Karrat Landslide Complex: Karrat 2009, Karrat 2016, and Karrat 2017. The latter is the source of the abovementioned tsunami, whereas the first two are described here in detail for the first time. All three are interpreted as having initiated as dip-slope failures. In addition to the recent rock avalanches, older rock avalanche deposits are observed, demonstrating older (Holocene) periods of activity. Furthermore, three larger unstable rock slopes that may pose a future hazard are described. A number of non-tectonic seismic events confined to the area are interpreted as recording rock slope failures. The structural setting of the Karrat Landslide Complex, namely dip slope, is probably the main conditioning factor for the past and present activity, and, based on the temporal distribution of events in the area, we speculate that the possible trigger for rock slope failures is permafrost degradation caused by climate warming. The results of the present work highlight the benefits of a multidisciplinary approach, based on freely available data, to studying unstable rock slopes in remote Arctic areas under difficult logistical field conditions and demonstrate the importance of identifying minor precursor events to identify areas of future hazard.

The Pretare-Piedilama rock block deposit: evidence of a further case of quaternary rock avalanche in Central Apennines, Italy 

2021 ◽  
Author(s):  
Maria Luisa Putignano ◽  
Emiliano Di Luzio ◽  
Luca Schilirò ◽  
Andrea Pietrosante ◽  
Salvatore Ivo Giano
Keyword(s):  
Slope Failure ◽  
Rock Slope ◽  
Central Italy ◽  
Rock Avalanche ◽  
Rock Block ◽  
High Mountain ◽  
Mountain Range ◽  
Central Apennines ◽  
Massive Rock ◽  
Rock Avalanches

<p>In the last two decades large clastic deposits in Central Apennines with specific morphological and sedimentological features have been interpreted as the result of Quaternary rock avalanche events (e.g., Di Luzio et al., 2004; Bianchi Fasani et al., 2014; Schilirò et al., 2019; Antonielli et al., 2020). The analysis of such deposits, that are located within intermontane basins and narrow valleys bounded by high mountain ridges, have improved the knowledge about this kind of massive rock slope failures, also clarifying their relationship with Deep-seated Gravitational Slope Deformations.</p><p>The present study then describes a multidisciplinary analysis carried out on a huge rock block deposit which crops out within the Pretare-Piedilama Valley, in the piedmont junction area of the Sibillini Mountain range (Central Italy), where Mesozoic basinal carbonates overthrust Miocene foredeep deposits.</p><p>Specifically, we performed sedimentological, stratigraphical and morphometric analyses on the clastic deposit; results support the interpretation of the event as a rock avalanche body. The accumulation area shows a T-like shape with a wide, E-W-oriented, proximal part and a N-S channelization in the central and lower sectors. The evidence suggests erosional events and tectonics as controlling factors on rock flow deposition. In this respect, the area was involved in the 2016 central Italy seismic sequence and was tectonically active during Quaternary times<strong> </strong>(Tortorici et al., 2009).</p><p>As regards on the deposit genesis, considering the geometric characteristics of a sub-rectangular detachment area located on the southern edge of the Sibillini Range, an original mechanism of rockslide failure involving about 8·10<sup>6</sup>m<sup>3</sup> of Early Jurassic limestone was inferred. Here, the post-failure geomorphic features behind the main scarp are considered for the evaluation of hazard conditions.</p><p>Finally, well-log analysis of the clastic sequence filling the Pretare-Piedilama Valley evidenced additional Quaternary landslide events occurred before the rock avalanche, thus testifying to a long history of large slope instabilities in the area controlling the landscape development.</p><p> </p><p><strong>REFERENCES</strong></p><p> </p><ul><li>Antonielli B., Della Seta M., Esposito C., Scarascia-Mugnozza G., Schilirò L., Spadi M., Tallini M. (2020). Quaternary rock avalanches in the Apennines: New data and interpretation of the huge clastic deposit of the L'Aquila Basin (central Italy). Geomorphology, 361, 107-194. doi:10.1016/j.geomorph.2020.107194.</li> <li>Bianchi Fasani G., Di Luzio E., Esposito C., Evans S.G., Scarascia-Mugnozza G. (2014). Quaternary, catastrophic rock avalanches in the Central Apennines (Italy): relationships with inherited tectonic features, gravity-driven deformations and the geodynamic frame. Geomorphology, 21, 22–42. doi:10.1016/j.geomorph.2013.12.027.</li> <li>Di Luzio E., Bianchi-Fasani G., Saroli M., Esposito C., Cavinato G.P., Scarascia-Mugnozza G. (2004). Massive rock slope failure in the central Apennines (Italy): the case of the Campo di Giove rock avalanche. Bullettin of Engineering Geology and the Environment 63, 1-12. doi:10.1007/s10064-003-0212-7.</li> <li>Schilirò L., Esposito C., De Blasio F.V., Scarascia-Mugnozza G. (2019). <strong>Sediment texture in rock avalanche deposits: insights from field and experimental observations. </strong>Landslides, 16, 1629-1643. doi: 10.1007/s10346-019-01210-x.</li> <li>Tortorici G., Romagnoli G., Grassi S. et al. (2019). Quaternary negative tectonic inversion along the Sibillini Mts. thrust zone: the Arquata del Tronto case history (Central Italy). Environ Earth Sci 78:<strong> </strong>37. doi:10.1007/s12665-018-8021-2.</li> </ul>

scholarly journals On the influence of topographic, geological and cryospheric factors on rock avalanches and rockfalls in high-mountain areas

2012 ◽  
Vol 12 (1) ◽  
pp. 241-254 ◽  
Author(s):  
L. Fischer ◽  
R. S. Purves ◽  
C. Huggel ◽  
J. Noetzli ◽  
W. Haeberli
Keyword(s):  
Slope Failure ◽  
Temporal Distribution ◽  
High Mountain ◽  
European Alps ◽  
Permafrost Degradation ◽  
Slope Failures ◽  
Mountain Areas ◽  
Investigation Area ◽  
Rock Avalanches ◽  
Slope Instabilities

Abstract. The ongoing debate about the effects of changes in the high-mountain cryosphere on rockfalls and rock avalanches suggests a need for more knowledge about characteristics and distribution of recent rock-slope instabilities. This paper investigates 56 sites with slope failures between 1900 and 2007 in the central European Alps with respect to their geological and topographical settings and zones of possible permafrost degradation and glacial recession. Analyses of the temporal distribution show an increase in frequency within the last decades. A large proportion of the slope failures (60%) originated from a relatively small area above 3000 m a.s.l. (i.e. 10% of the entire investigation area). This increased proportion of detachment zones above 3000 m a.s.l. is postulated to be a result of a combination of factors, namely a larger proportion of high slope angles, high periglacial weathering due to recent glacier retreat (almost half of the slope failures having occurred in areas with recent deglaciation), and widespread permafrost occurrence. The lithological setting appears to influence volume rather than frequency of a slope failure. However, our analyses show that not only the changes in cryosphere, but also other factors which remain constant over long periods play an important role in slope failures.

scholarly journals Ambient noise and ERT data provide insights into the structure of co-seismic rock avalanche deposits in Sichuan (China)

2021 ◽  
Author(s):  
V. Del Gaudio ◽  
J. Wasowski ◽  
W. Hu ◽  
P. Capone ◽  
N. Venisti ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
Ambient Noise ◽  
Rock Avalanche ◽  
S Wave ◽  
Seismic Surveys ◽  
2008 Wenchuan Earthquake ◽  
Single Station ◽  
Resonance Properties ◽  
History Of ◽  
Seismic Landslide

AbstractThe post-seismic history of the 2008 Mw7.9 Wenchuan earthquake shows that marginally stable deposits of large co-seismic landslide dams can pose persistent debris flow hazards for the downstream areas. Here, we combine analyses of single-station recordings of ambient noise with electrical resistivity tomography (ERT) surveys to explore the potential of drawing information on structure and geometry of the deposit of a large rock avalanche triggered by the Mw 7.9 2008 Wenchuan earthquake, which dammed the Yangjia stream in the Sichuan Province (China). The substantial thickness and heterogeneity of this kind of deposits limit the application of standard geophysical techniques, like active seismic surveys, which require highly energetic sources and long linear geophone arrays to reach adequate investigation depths. Passive single-station methods, relying on ambient noise recordings to determine site resonance properties, controlled by the contrast between soft surface layers and a stiffer substratum, offer the opportunity of investigating subsoil properties down to larger depths. In particular, we use a recently developed technique, which isolates the contribution of Rayleigh waves to ambient noise and draws information on sub-soil properties from the inversion of Rayleigh wave ellipticity curves plotted as function of frequency. In this framework, the ERT data can support the ellipticity curve inversion, typically affected by highly non-univocal solutions, by providing constraints for defining of the thickness of the uppermost surficial layers. The results allowed inferring the overlap of different layers within the 2008 rock avalanche deposit, as well as estimating lateral variations in their thickness and S-wave (Vs) velocities.

scholarly journals Locating rock slope failures along highways and understanding their physical processes using seismic signals

2021 ◽  
Vol 9 (3) ◽  
pp. 505-517
Author(s):  
Jui-Ming Chang ◽  
Wei-An Chao ◽  
Hongey Chen ◽  
Yu-Ting Kuo ◽  
Che-Ming Yang
Keyword(s):  
Slope Failure ◽  
Rock Slope ◽  
Scaling Law ◽  
Mass Movement ◽  
Volume Estimation ◽  
Seismic Signals ◽  
Slope Failures ◽  
Physical Processes ◽  
Seismic Parameters ◽  
Duration Magnitude

Abstract. Regional monitoring of rock slope failures using the seismic technique is rarely undertaken due to significant source location errors; this method also still lacks the signal features needed to understand events of this type because of the complex mass movement involved. To better comprehend these types of events, 10 known events along highways in Taiwan were analyzed. First, a hybrid method (GeoLoc) composed of cross-correlation-based and amplitude-attenuation-based approaches was applied, and it produced a maximum location error of 3.19 km for the 10 events. We then analyzed the ratio of local magnitude (ML) and duration magnitude (MD) and found that a threshold of 0.85 yields successful classification between rock slope failure and earthquake. Further, GeoLoc can retrieve the seismic parameters, such as signal amplitude at the source (A0) and ML of events, which are crucial for constructing scaling law with source volume (V). Indeed, Log(V) = 1.12 ML + 3.08 and V = 77 290 A00.44 derived in this study provide the lower bound of volume estimation, as the seismic parameters based on peak amplitudes cannot represent the full process of mass loss. Second, while video records correspond to seismic signals, the processes of toppling and sliding present column- and V-shaped spectrograms, respectively. The impacts of rockfall link directly to the pulses of seismic signals. Here, all spectrogram features of events can be identified for events with volumes larger than 2000 m3, corresponding to the farthest epicenter distance of ∼ 2.5 km. These results were obtained using the GeoLoc scheme for providing the government with rapid reports for reference. Finally, a recent event on 12 June 2020 was used to examine the GeoLoc scheme's feasibility. We estimated the event's volume using two scalings: 3838 and 3019 m3. These values were roughly consistent with the volume estimation of 5142 m3 from the digital elevation model. The physical processes, including rockfall, toppling, and complex motion behaviors of rock interacting with slope inferred from the spectrogram features were comprehensively supported by the video record and field investigation. We also demonstrated that the GeoLoc scheme, which has been implemented in Sinwulyu catchment, Taiwan, can provide fast reports, including the location, volume, and physical process of events, to the public soon after they occur.

Dynamic simulation of the motion of fragmenting rock avalanches

2002 ◽  
Vol 39 (4) ◽  
pp. 789-798 ◽  
Author(s):  
T R Davies ◽  
M J McSaveney
Keyword(s):  
Field Data ◽  
Mass Movement ◽  
Rock Avalanche ◽  
Earth Pressure ◽  
Long Runout ◽  
Analogue Model ◽  
Pressure Coefficients ◽  
Rock Avalanches ◽  
Internal Pressures ◽  
Rapid Mass

A mass-referenced continuum model for dynamic analysis of rapid mass movement (DAN) is verified by laboratory and field data. Increased earth pressure coefficients are used in this model to represent the dispersive pressures caused by fragmentation within a translating rock avalanche. The numerical model demonstrates that increased runout in large rock avalanches can occur with normal friction coefficients if higher than normal internal pressures, such as those believed to be generated by fragmentation, are present. The extent of the Falling Mountain rock-avalanche deposit in New Zealand is reproduced in the model with normal friction and high earth pressure coefficients to represent by analogy the additional internal pressures due to fragmentation. It appears that if internal friction is changed by fragmentation, it is only by a small amount and may increase rather than decrease. To test this, and to move beyond the present analogue model, requires a better understanding of the rheology of fragmenting rock.Key words: rock avalanches, long runout, fragmentation, simulation model, dispersive stresses, earth pressure coefficients, Falling Mountain.

scholarly journals Empirical prediction for travel distance of channelized rock avalanches in the Wenchuan earthquake area

2016 ◽  
Author(s):  
Weiwei Zhan ◽  
Xuanmei Fan ◽  
Runqiu Huang ◽  
Xiangjun Pei ◽  
Qiang Xu ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
Prediction Models ◽  
Rock Avalanche ◽  
Field Investigation ◽  
Travel Distance ◽  
Validation Dataset ◽  
Good Prediction ◽  
Visual Interpretation ◽  
Rock Avalanches ◽  
Landslide Volume

Abstract. Rock avalanches are extremely rapid, massive flow-like movements of fragmented rock. The travel path of the rock avalanches may be confined by channels in some cases, which were named as the channelized rock avalanches. Channelized rock avalanches are potentially dangerous due to their hardly predictable travel distance. In this study, we constructed a dataset with detailed characteristic parameters of 38 channelized rock avalanches triggered by the 2008 Wenchuan earthquake using the visual interpretation of remote sensing imagery, field investigation, and literature review. Based on this dataset, we assessed the influence of different factors on the runout distance and developed prediction models of the channelized rock avalanches using the multivariate regression method. The results suggested that the movement of channelized rock avalanche was dominated by the landslide volume, total relief, and channel gradient. The performance of both models was then tested with an independent validation dataset of 8 rock avalanches that induced by the 2008 Wenchuan, the Ms7.0 Lushan earthquake, and heavy rainfall in 2013, showing acceptable good prediction results. Therefore, the travel distance prediction models for channelized rock avalanches constructed in this study is applicable and reliable for predicting the run out of similar rock avalanches in other regions.

Sign in / Sign up

Export Citation Format

Share Document