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| Titel |
Evaluation of potential meteorological triggers of large landslides in sensitive glaciomarine clay, eastern Canada |
| VerfasserIn |
D. Gauthier, D. J. Hutchinson |
| 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 ; 12, no. 11 ; Nr. 12, no. 11 (2012-11-14), S.3359-3375 |
| Datensatznummer |
250011195
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| Publikation (Nr.) |
 copernicus.org/nhess-12-3359-2012.pdf |
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| Zusammenfassung |
| Heavy rains spread over some interval preceding large
landslides in sensitive glaciomarine clay in eastern Canada are often noted
as a triggering or causative factor in case studies or research reports for
individual landslides, although the quantity or duration of the triggering
rain event has never been characterized adequately. We selected five large
landslide events that occurred in the glaciomarine clay in eastern Canada,
and calculated cumulative antecedent precipitation for intervals ranging
between one and 365 days preceding each event. We also calculated the
antecedent precipitation values for every other day in the record, and
computed the relative rank of the landslide day within the complete record.
Our results show that several intervals for each landslide event are highly
ranked – including those preceding a presumably earthquake-triggered
landslide – but overall the rankings were highly variable, ranging between
99% and 6%. The set of highest-ranking intervals are unique for each
event, including both short and long-term cumulative precipitation. All of
the landslides occurred in the spring months, and the release of sequestered
surface and ground water during the spring ground thaw may be related to the
timing of the large landslides, so that the evolution of ground frost in the
early winter may be of interest for landslide prediction. We found no simple
precipitation threshold for triggering large landslides in sensitive
glaciomarine clay in eastern Canada, suggesting that some complex temporal
and spatial combination of pre-conditions, external energy (e.g. earthquakes),
precipitation triggers and other factors such as ground frost
formation and thaw are required to trigger a landslide. |
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