James Terry

Collaborators:

James Goff University of New South Wales, Australia

Nigel Winspear Catastrophe Risk Consultant, Singapore

Kruawun Jankaew Chulalongkorn University, Thailand

Interdisciplinary collaboration on tsunamis and typhoons in the

greater South China Sea.

Do we fully understand the potential risks?

Steering Group on Natural Hazards and Disaster RiskICSU Regional Office For Asia and the Pacific

Chao Phraya Delta: at “low risk”

(according to the World Bank 2010)

Our interpretation for the Bay of Bangkok: At risk!

Methods for risk determination:

1. Recent storm records

2. Historical archives

3. Geological evidence

Shoreline retreat

Subsidence1.5 m

Age-dating using U:Th – Ko Larn coastal boulders

“Gravity vs the Waves”Hypothesised

Tracks

Forecast Tracks: Asia Typhoon Model

Newly recognised potential

tsunami sources for the

South China Sea

SCS potential tsunami

sources by thematic type

Megathrust

earthquakes

Fault activity

Volcanism

Major submarine

landslides

Flank collapse of

carbonate buildups

Potential for atoll flank collapse in the South China Sea?

atolls

active

volcanoes

atolls

Paracel carbonate platform slides. From Yubo et al. (2011)

Note the carbonate debris flows, some dating from the middle Miocene

Makin Atoll, Kiribati

Oral legends of Rebua RockPhoto courtesy of Emili Artack, SOPAC

Funafuti, Tuvalu - atoll shape and bathymetry

Landslide scar

(with lobe of debris

at depth?)

ABLS

(image courtesy of SOPAC)

Conclusions

Multiple likely sources for tsunamis in the SCS

Significant uncertainty in existing modelling of Brunei

megaslide

Proposed further interdisciplinary work to establish the

magnitude–timing–frequency of past tsunami events.

Late Holocene typhoons have penetrated the upper

Gulf of Thailand (possibly at higher than historically-

recorded intensities).

Safe coastal perception for Bangkok is a blind spot that

needs revision.

The instrumental record is an inadequate guide to

potential typhoon paths and maximum intensity.