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| Titel |
Extraordinary distance limits of landslides triggered by the 2011 Virginia earthquake, USA |
| VerfasserIn |
Randall W. Jibson, Edwin L. Harp |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074743
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| Zusammenfassung |
| The 23 August 2011 Mineral, Virginia earthquake (Mw 5.8) was the largest to strike the
eastern U.S. since 1897 and was felt over an extraordinarily large area. Though no large
landslides occurred, the shaking did trigger many rock and soil falls from steep river banks
and natural cliffs in the epicentral area and from steep road cuts along and northwest of the
Blue Ridge Parkway. We mapped the occurrence of rock falls to determine distance limits
that could be compared with those from other documented earthquakes. Studies of previous
earthquakes indicated a maximum epicentral distance limit for landsliding of about 60 km for
a M-5.8 earthquake; the maximum distance limit for the 2011 earthquake was 245 km, the
largest exceedance of the historical limit ever recorded. Likewise, the previous maximum
area affected by landslides for this magnitude was 1,500 km2; the area affected by
landslides in the 2011 earthquake was 33,400 km2. These observations provide physical
evidence that attenuation of strong shaking for eastern U.S. earthquakes is significantly
lower than for plate-boundary earthquakes. Also, distance limits parallel to the
regional structural trend are greater than those that transect the structure, which
suggests anisotropic attenuation related to the regional geologic structure. Peak ground
acceleration at the landslide distance limits is estimated to have been about 0.02-0.04 g. |
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