IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Poster presentation 1803
Revision and update of the tsunami database for New Zealand
Mrs. Gaye Downes
IASPEI
Willem P. De Lange
In the last decade there have been many advances in the science of tsunamis, and tsunami hazard and
risk assessment. Despite these advances, the historical record of tsunami impact, once almost the only
tool for tsunami-hazard assessment, continues to have an important role. Thispresentation reports on
recent revisions and updates of the tsunami database. In New Zealands short written historical record of
just over 165 years, more than 50 local, regional and distant source tsunamis have occurred, some very
isolated landslide-generated events in confined waters (e.g. fiords), some observable on tide-gauge
records only, some local events large enough to be detectable elsewhere in the Pacific, and others large
enough to have caused disastrous impact, had they occurred at a time and place of more significant
coastal settlement. New Zealand has had a fairly comprehensive tsunami database since 1986 (de
Lange & Healy, 1986). Recent events, such as the small 4 May 2006 tsunami (max. peak-to-trough in
NZ, 0.35 m) and the December 2004 Sumatra tsunami (max peak-to-trough, 1.05 m), have been added.
In addition, in-depth searching of historical records in the last five years has uncovered new historical
tsunamis and extensive further data on known tsunamis. At present, the tsunami database is being
developed as an Excel spreadsheet. Many fields are incorporated, including source parameter fields
(with references) and impact fields, with separate entries for tide-gauge data (for example, maximum
crest-to-trough heights, amplitude, first motion and predominant period), and observed data (for
example, run-up, maximum inundation, brief referenced extracts from historical documents), as well as
event summaries and key references to publications on specific events. The Excel database will be
converted to a Web-based searchable interface, with tools to download and display data. In addition to
the Excel database, transcribing of historical accounts is also in progress. These materials provide
resources for researchers, emergency managers and planners, and for public education and community
awareness. De Lange, W P and Healy, T R (1986). New Zealand tsunamis 1840-1982. Journal of
geology and geophysics 2, 115-134.
Keywords: tsunami database, tsunami hazard