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| Titel |
Liquefaction phenomena associated with the Emilia earthquake sequence of May-June 2012 (Northern Italy) |
| VerfasserIn |
Emergeo Working Group |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 13, no. 4 ; Nr. 13, no. 4 (2013-04-18), S.935-947 |
| Datensatznummer |
250018407
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| Publikation (Nr.) |
 copernicus.org/nhess-13-935-2013.pdf |
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| Zusammenfassung |
| In this paper we present the geological effects induced by the 2012 Emilia
seismic sequence in the Po Plain. Extensive liquefaction phenomena were
observed over an area of ~ 1200 km2 following the 20 May,
ML 5.9 and 29 May, ML 5.8 mainshocks; both occurred on about E–W trending, S
dipping blind thrust faults. We collected the coseismic geological evidence
through field and aerial surveys, reports from local people and Web-based
survey. On the basis of their morphologic and structural characteristics, we
grouped the 1362 effects surveyed into three main categories: liquefaction
(485), fractures with liquefaction (768), and fractures (109). We show that the
quite uneven distribution of liquefaction effects, which appear concentrated
and aligned, is mostly controlled by the presence of paleo-riverbeds,
out-flow channels and fans of the main rivers crossing the area; these
terrains are characterised by the pervasive presence of sandy layers in the
uppermost 5 m, a local feature that, along with the presence of a high water
table, greatly favours liquefaction. We also find that the maximum distance
of observed liquefaction from the earthquake epicentre is ~ 30 km, in agreement with the regional empirical relations available for the
Italian Peninsula. Finally, we observe that the contour of the liquefaction
observations has an elongated shape almost coinciding with the aftershock
area, the InSAR deformation area, and the I ≥ 6 EMS area. This
observation confirms the control of the earthquake source on the
liquefaction distribution, and provides useful hints in the characterisation of the seismogenic source responsible for historical
and pre-historical liquefactions. |
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