Tsunamigenic slope failures: the Pacific Islands ‘blind spot’?

Document Type

Article

Source of Publication

Landslides

Publication Date

12-1-2016

Abstract

© 2015, Springer-Verlag Berlin Heidelberg. We discuss issues related to a recognised shortcoming in existing tsunami hazard assessments for Pacific Island Countries and Territories (PICTs), that of tsunamigenic slope failures (TSFs). Currently, TSFs are most likely underrepresented as sources in existing tsunami databases for two key reasons. First, relatively low magnitude earthquakes associated with subduction zones are generally assigned as the tsunamigenic source, as opposed to the TSFs they generate. A reassessment of such ‘anomalous tsunamis’ may yield clues that serve to reassign their tsunamigenic source. Second, there are thousands of oceanic islands and seamounts scattered across the Pacific and flank collapse of volcanic edifices such as these is a largely unquantified tsunamigenic threat. However, while it is now possible to model such TSFs, this is unlikely to happen in the near future because of the lack of detailed bathymetry and landslide mass data. Recent developments in the identification of past tsunamis in the Pacific Islands have developed a unique range of indicators that can be used for identifying such events. These are geological, oral tradition and archaeological components that include, but are not limited to, a modified Darwinian model of atoll formation, coastal megaclasts, oral traditions of vanished islands and giant waves, and the abandonment of prehistoric coastal sites. As such, the most logical way forward is to use the multiple indicators available to us to identify evidence of past tsunamis.

ISSN

1612-510X

Publisher

Springer Verlag

Volume

13

Issue

6

First Page

1535

Last Page

1543

Disciplines

Life Sciences

Keywords

Flank collapse, Pacific Islands, Palaeotsunami indicators, Tsunamigenic slope failures

Scopus ID

84945548812

Indexed in Scopus

yes

Open Access

no

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