Rainfall triggers more deep-seated landslides than Cascadia earthquakes in the Oregon Coast Range, USA
| Autor: | Joseph Wartman, Joshua J. Roering, Alison R. Duvall, Alex Grant, William Struble, Benjamin A Mishkin, Adam M. Booth, Sean Richard LaHusen, David R. Montgomery |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
geography
Peak ground acceleration Multidisciplinary geography.geographical_feature_category 010504 meteorology & atmospheric sciences Subduction Bedrock SciAdv r-articles Magnitude (mathematics) Geology Landslide Coast range 010502 geochemistry & geophysics 01 natural sciences Large earthquakes Precipitation Research Articles Seismology Research Article 0105 earth and related environmental sciences |
| Zdroj: | Science Advances |
| ISSN: | 2375-2548 |
| Popis: | Deep-seated landslides in the central Oregon Coast Range are triggered mostly by rainfall, not large Cascadia earthquakes. The coastal Pacific Northwest USA hosts thousands of deep-seated landslides. Historic landslides have primarily been triggered by rainfall, but the region is also prone to large earthquakes on the 1100-km-long Cascadia Subduction Zone megathrust. Little is known about the number of landslides triggered by these earthquakes because the last magnitude 9 rupture occurred in 1700 CE. Here, we map 9938 deep-seated bedrock landslides in the Oregon Coast Range and use surface roughness dating to estimate that past earthquakes triggered fewer than half of the landslides in the past 1000 years. We find landslide frequency increases with mean annual precipitation but not with modeled peak ground acceleration or proximity to the megathrust. Our results agree with findings about other recent subduction zone earthquakes where relatively few deep-seated landslides were mapped and suggest that despite proximity to the megathrust, most deep-seated landslides in the Oregon Coast Range were triggered by rainfall. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|