Seismic and geological controls on earthquake-induced landslide size
| Autor: | Giovanni B. Crosta, Odin Marc, Andrea Valagussa, Paolo Frattini |
|---|---|
| Přispěvatelé: | Valagussa, A, Marc, O, Frattini, P, Crosta, G |
| Rok vydání: | 2019 |
| Předmět: |
Ground motion
010504 meteorology & atmospheric sciences Frequency of occurrence Lithology New guinea Landslide Earthquake magnitude 010502 geochemistry & geophysics 01 natural sciences Geophysics Fault trace Space and Planetary Science Geochemistry and Petrology Epicenter Earth and Planetary Sciences (miscellaneous) earthquake landslide magnitude–frequency distribution seismic source ground motion lithology Seismology Geology 0105 earth and related environmental sciences |
| Zdroj: | Earth and Planetary Science Letters |
| Popis: | Landslide size controls the destructive power of landslides and is related to the frequency of occurrence, with larger landslides being less frequent than smaller ones. For this reason, the analysis of landslide size is essential for landslide hazard assessment. We analyse six earthquake-induced landslide inventories with earthquake magnitude ranging between 6.6 and 7.9 Mw (Papua New Guinea, 1993; ChiChi 1999; Northridge, 1994; Niigata–Chuetsu, 2004; Iwate–Miyagi Nairiku, 2008; Wenchuan, 2008). For each inventory, we developed magnitude–frequency curves to analyse the size distribution of landslides as a function of ground motion, distance from the seismic source (both fault trace and epicentre), local relief, and lithology. For three earthquakes, we observed a clear relationship between the landslide size and ground motion, with larger landslides associated with higher ground motion. We investigate different possible causes for such observation, and propose that the main mechanical reason is that stronger shaking induces higher stresses that may overcome the strength, which increases with depth, triggering larger landslides. We also show that landslide size decreases with distance from the fault trace, whereas, this trend is not clear for distance from the epicentre. Local relief does not seem a first order control on landslide size for the earthquake-induced landslides considered here. Some lithologies do influence landslide size, but we were unable to identify a general behaviour for different lithologies. |
| Databáze: | OpenAIRE |
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