Abstract

The Indian Ocean Tsunami of December 26, 2004 made starkly evident the need for better information on tsunami hazard in the Indian Ocean. The tsunami threat faced by Indian Ocean countries consists of a complex mix of tsunami from local, regional and distant sources, whose effects at any particular location in the Indian Ocean are highly dependent on variations in sea floor shape between the source and affected coastlines, complicating tsunami disaster management and the design of tsunami warning systems for the Indian Ocean. In order to provide national governments in the Indian Ocean with the information they need to make informed decisions about tsunami mitigation measures, including development of a warning system, a comprehensive hazard and risk ass In this presentation we discuss the results of this assessment. The study focused on tsunami caused by subduction zone earthquakes, because they are the most frequent source of large tsunami, and tsunami hazard is expressed as annual probability of a tsunami exceeding a given amplitude at a given offshore depth. Because so little is known about the recurrence rates of large megathrust earthquakes in the subduction zones bordering the Indian Ocean, it was decided to develop two hazard maps: a 'low-hazard' end member, based on only those earthquake sources of tsunami for which there is definite evidence, and a 'high-hazard' end member, based on all potential megathrust earthquake sources, including hypothetical ones for which there is no historical or geological evidence, that may affect Indian Ocean coastlines. The actual hazard lies somewhere between these two end members, and the difference between the low hazard and high hazard maps is a simple and effective way to express the uncertainty in the hazard assessment. This uncertainty reflects the lack of knowledge of tsunamigenic earthquake occurrence, and can only be reduced through a better understanding of earthquake and tsunami occurrence in the Indian Ocean.
Google map showing geographic bounding box with values North bound East bound West bound South bound
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Product Type/Sub Type

nonGeographicDataset - GA Publication - Professional Opinion

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2009

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

Keywords

GA Publication
Professional Opinion
geohazards
earthquakes
tsunamis
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Lineage

Unknown

Digital Transfer Options

onLine

DISTRIBUTION Format

pdf

Distributor

Role
distributor
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

a05f7892-ea90-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

Metadata Date Stamp

2009-03-16

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Downloads
For information on acquiring this product,
please contact Geoscience Australia Client Services via:

fax:
+61 2 6249 9960; or
phone:
1800 800 173 (within Australia);
 
+61 2 6249 9966 (outside Australia).