Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake
<p>The propagation of a seismic rupture on a fault introduces spatial variations in the seismic wave field surrounding the fault. This directivity effect results in larger shaking amplitudes in the rupture propagation direction. Its seismic radiation pattern also causes amplitude variations...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-04-01
|
| Series: | Solid Earth |
| Online Access: | https://www.solid-earth.net/10/463/2019/se-10-463-2019.pdf |
| _version_ | 1818262992653910016 |
|---|---|
| author | S. von Specht S. von Specht S. von Specht U. Ozturk U. Ozturk U. Ozturk G. Veh F. Cotton F. Cotton O. Korup O. Korup |
| author_facet | S. von Specht S. von Specht S. von Specht U. Ozturk U. Ozturk U. Ozturk G. Veh F. Cotton F. Cotton O. Korup O. Korup |
| author_sort | S. von Specht |
| collection | DOAJ |
| description | <p>The propagation of a seismic rupture on a fault introduces spatial variations
in the seismic wave field surrounding the fault. This directivity effect
results in larger shaking amplitudes in the rupture propagation direction.
Its seismic radiation pattern also causes amplitude variations between the
strike-normal and strike-parallel components of horizontal ground motion. We
investigated the landslide response to these effects during the 2016 Kumamoto
earthquake (<i>M</i><sub>w</sub> 7.1) in central Kyushu (Japan). Although the
distribution of some 1500 earthquake-triggered landslides as a function of
rupture distance is consistent with the observed Arias intensity, the
landslides were more concentrated to the northeast of the
southwest–northeast striking rupture. We examined several landslide
susceptibility factors: hillslope inclination, the median amplification
factor (MAF) of ground shaking, lithology, land cover, and topographic
wetness. None of these factors sufficiently explains the landslide
distribution or orientation (aspect), although the landslide head scarps have
an elevated hillslope inclination and MAF. We propose a new physics-based
ground-motion model (GMM) that
accounts for the seismic rupture effects, and we demonstrate that the
low-frequency seismic radiation pattern is consistent with the overall
landslide distribution. Its spatial pattern is influenced by the rupture
directivity effect, whereas landslide aspect is influenced by amplitude
variations between the fault-normal and
fault-parallel motion at frequencies < 2 Hz. This azimuth dependence
implies that comparable landslide concentrations can occur at different
distances from the rupture. This quantitative link between the prevalent
landslide aspect and the low-frequency seismic radiation pattern can improve
coseismic landslide hazard assessment.</p> |
| first_indexed | 2024-12-12T19:11:56Z |
| format | Article |
| id | doaj.art-2d81e6e9741c46d0b7bc5da5450daf1a |
| institution | Directory Open Access Journal |
| issn | 1869-9510 1869-9529 |
| language | English |
| last_indexed | 2024-12-12T19:11:56Z |
| publishDate | 2019-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Solid Earth |
| spelling | doaj.art-2d81e6e9741c46d0b7bc5da5450daf1a2022-12-22T00:14:49ZengCopernicus PublicationsSolid Earth1869-95101869-95292019-04-011046348610.5194/se-10-463-2019Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquakeS. von Specht0S. von Specht1S. von Specht2U. Ozturk3U. Ozturk4U. Ozturk5G. Veh6F. Cotton7F. Cotton8O. Korup9O. Korup10Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanyUniversity of Potsdam, Institute of Geosciences, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, GermanyUniversity of Potsdam, Institute of Environmental Science and Geography, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, GermanyHelmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanyUniversity of Potsdam, Institute of Environmental Science and Geography, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, GermanyPotsdam Institute for Climate Impact Research (PIK) e.V., Telegrafenberg, 14473 Potsdam, GermanyUniversity of Potsdam, Institute of Environmental Science and Geography, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, GermanyHelmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanyUniversity of Potsdam, Institute of Geosciences, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, GermanyUniversity of Potsdam, Institute of Geosciences, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, GermanyUniversity of Potsdam, Institute of Environmental Science and Geography, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, Germany<p>The propagation of a seismic rupture on a fault introduces spatial variations in the seismic wave field surrounding the fault. This directivity effect results in larger shaking amplitudes in the rupture propagation direction. Its seismic radiation pattern also causes amplitude variations between the strike-normal and strike-parallel components of horizontal ground motion. We investigated the landslide response to these effects during the 2016 Kumamoto earthquake (<i>M</i><sub>w</sub> 7.1) in central Kyushu (Japan). Although the distribution of some 1500 earthquake-triggered landslides as a function of rupture distance is consistent with the observed Arias intensity, the landslides were more concentrated to the northeast of the southwest–northeast striking rupture. We examined several landslide susceptibility factors: hillslope inclination, the median amplification factor (MAF) of ground shaking, lithology, land cover, and topographic wetness. None of these factors sufficiently explains the landslide distribution or orientation (aspect), although the landslide head scarps have an elevated hillslope inclination and MAF. We propose a new physics-based ground-motion model (GMM) that accounts for the seismic rupture effects, and we demonstrate that the low-frequency seismic radiation pattern is consistent with the overall landslide distribution. Its spatial pattern is influenced by the rupture directivity effect, whereas landslide aspect is influenced by amplitude variations between the fault-normal and fault-parallel motion at frequencies < 2 Hz. This azimuth dependence implies that comparable landslide concentrations can occur at different distances from the rupture. This quantitative link between the prevalent landslide aspect and the low-frequency seismic radiation pattern can improve coseismic landslide hazard assessment.</p>https://www.solid-earth.net/10/463/2019/se-10-463-2019.pdf |
| spellingShingle | S. von Specht S. von Specht S. von Specht U. Ozturk U. Ozturk U. Ozturk G. Veh F. Cotton F. Cotton O. Korup O. Korup Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake Solid Earth |
| title | Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake |
| title_full | Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake |
| title_fullStr | Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake |
| title_full_unstemmed | Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake |
| title_short | Effects of finite source rupture on landslide triggering: the 2016 <i>M</i><sub>w</sub> 7.1 Kumamoto earthquake |
| title_sort | effects of finite source rupture on landslide triggering the 2016 i m i sub w sub 7 1 kumamoto earthquake |
| url | https://www.solid-earth.net/10/463/2019/se-10-463-2019.pdf |
| work_keys_str_mv | AT svonspecht effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT svonspecht effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT svonspecht effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT uozturk effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT uozturk effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT uozturk effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT gveh effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT fcotton effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT fcotton effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT okorup effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake AT okorup effectsoffinitesourceruptureonlandslidetriggeringthe2016imisubwsub71kumamotoearthquake |