scholarly journals Evidence of recurrent mass movement in front of the maximum slip area of the 1960 Chile earthquake: Implications for risk assessment and paleoseismology

2020 ◽  
Author(s):  
Cristian Araya-Cornejo ◽  
Matías carvajal ◽  
Jasper Moernaut ◽  
Felipe González ◽  
Marco Cisternas
2020 ◽  
Author(s):  
Cristian Araya-Cornejo ◽  
Matías Carvajal ◽  
Jasper Moernaut ◽  
Felipe González ◽  
Marco Cisternas

2020 ◽  
Vol 66 (2) ◽  
pp. 94-110
Author(s):  
Vibhash C Jha ◽  
◽  
Subhasis Ghosh ◽  

A proper geomorphic study of a region can be useful in understanding past and present environmental circumstances and analyzing potential environmental risks. Careful analysis of morphodynamic processes and existing diagnostic landforms reveal several aspects about the origin, characteristics and possible pattern of morpho-climatic interactions on the landscape over temporal scale, which helps significantly in proper terrain evaluation from societal welfare and integrated management point of view, including environmental risk assessment and disaster management. This paper has made a thorough geomorphic investigation based on intensive fieldwork and multi-sourced remote sensing data to characterize the lateritic soil profile and landforms of the study area in respect to their morphology and Physico-chemical properties at the different sites of land degradation to understand the outcome of morphoclimatic interactions on the landscape over time, and to evaluate the severity of operation with pedo-geomorphic constraints in the lateritic environment for sustainable management purposes. It is found that the region is highly sensitive to weathering, mass movement and denudational activities, mainly caused by rainwater erosion which has resulted into varied landforms including well-developed rills and gullies, lateritic ridges, isolated residual hills etc and generated a unique identity to this part of the lateritic region. The study also suggested a model for the development of geomorphic landforms in a lateritic terrain based on past and present morphoclimatic interactions, nature of physiography, lithology, soil characteristics and other biotic and abiotic elements. The region is also found to be a subject to moderate to severe land degradation due to the active geomorphic processes in operation in tropical regions and inherently poor physical and chemical formation of the existing soil profile and radical conversion of land uses as observed at cadastral level leading towards irresistible desertification. Annual topsoil loss amount has been calculated using the Universal Soil Loss Equation method. Three sample Mouzas namely Ballavpur, Shyambati and Chawpahari jungle have been assessed to be having 36.98%, 71.42% and 61.73% of degraded land in respect to their total village area. Various conservative measures like stabilization of gully heads and beds through reforestation and afforestation with cutting earth plug, brush fills and check dams; improvement of the irrigation network, suitable dryland farming etc. have been recommended to arrest the desertification process.


2016 ◽  
Vol 51 (1) ◽  
pp. 17-28
Author(s):  
Miloslav Nechyba ◽  
Zuzana Vařilová ◽  
Pavel Kotva ◽  
Jan Kropáček ◽  
Jiří Zvelebil

2016 ◽  
Vol 10 (03) ◽  
pp. 1640008 ◽  
Author(s):  
Wataru Suzuki ◽  
Nelson Pulido ◽  
Shin Aoi

To investigate the rupture process and strong-motion generation of the [Formula: see text] 8.2 Iquique, Northern Chile, earthquake in 2014, we estimated kinematic source models from waveform inversion and back-projection analyses using strong-motion records. A slip model derived from the waveform inversion using the low-frequency (0.02–0.125[Formula: see text]Hz) velocities is characterized by a large slip area localized 50[Formula: see text]km south of the epicenter with a peak slip of 10[Formula: see text]m, and a deeper slip area with a peak slip above 2[Formula: see text]m located below the coast. The main rupture of these areas started 25[Formula: see text]s after the initial break generating two pronounced phases observed in most of the records. The landward slip area ruptured for about 10[Formula: see text]s generating the first impulsive phase, while the offshore largest slip area ruptured for 20[Formula: see text]s creating a longer duration phase observed later. Results from a back-projection analysis based on stacking of envelopes of 5–10-Hz accelerations indicate that the high-frequency radiation propagated down-dip towards the coast, reaching its maximum value from 25[Formula: see text]s to 40[Formula: see text]s, far away from the shallow main slip area obtained from low-frequency waveform inversion. Our results suggest a clear depth dependence of the seismic wave radiation during the Iquique earthquake.


2002 ◽  
Vol 39 (1) ◽  
pp. 193-212 ◽  
Author(s):  
Jacques Locat ◽  
Homa J Lee

Due to the recent development of well-integrated surveying techniques of the sea floor, significant improvements were achieved in mapping and describing the morphology and architecture of submarine mass movements. Except for the occurrence of turbidity currents, the aquatic environment (marine and fresh water) experiences the same type of mass failure as that found on land. Submarine mass movements, however, can have run-out distances in excess of 100 km, so their impact on any offshore activity needs to be integrated over a wide area. This great mobility of submarine mass movements is still not very well understood, particularly for cases like the far-reaching debris flows mapped on the Mississippi Fan and the large submarine rock avalanches found around many volcanic islands. A major challenge ahead is the integration of mass movement mechanics in an appropriate evaluation of the hazard so that proper risk assessment methodologies can be developed and implemented for various human activities offshore, including the development of natural resources and the establishment of reliable communication corridors.Key words: submarine slides, hazards, risk assessment, morphology, mobility, tsunami.


2019 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
Tuan Anh Bui ◽  
Teuku Faisal Fathani ◽  
Wahyu Wilopo

Landslide is the most frequent natural disaster in Yogyakarta, Indonesia. In the mid-March 2018, a few cracks appeared in the north of the hill in the Pendoworejo Village, Kulon Progo District, Yogyakarta Special Province. The landslide movement of this area still threatens the residents and makes them evacuated due to their fear upon potential landslide disaster. In order to reduce the risk, landslide investigation and risk assessment were conducted. The stability analysis focused on the relationship of the displacement,the velocity and the fluctuation of groundwater level due to the rainfall intensity. Then, a monitoring and warning system was designed as a non-structural mitigation effort. Based on the preliminary investigation on April 2018, there was no evidence of mass movement on the west and south part of the hill. On the other hand, the north part area was estimated to have risk as indicated by the occurrence of many cracks. Based on the result of analysis, the fluctuation of the groundwater level rose or dropped substantially before and after heavy rainfall. In the rainy season, the velocity and the displacement increased slightly in the first three months and grew rapidly afterward. In fact, the landslide risk increased in every rainy season. Therefore, the risk could be more dangerous in the future.


1998 ◽  
Vol 62 (10) ◽  
pp. 756-761 ◽  
Author(s):  
CW Douglass
Keyword(s):  

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