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Observations by the International
Tsunami Survey Team in Sri Lanka
Philip L.-F. Liu,
1
Patrick Lynett,
2
*Harindra Fernando,
3
Bruce E. Jaffe,
4
Hermann Fritz,
5
Bretwood Higman,
6
Robert Morton,
4
James Goff,
7
Costas Synolakis
8
On 26 December 2004 at 00:58:53 universal
time (U.T.), an earthquake of surface wave
magnitude (M
s
) 9.0 occurred off the west coast
of northern Sumatra. Large tsu-
namis were generated that severe-
ly damaged coastal communities
in countries around the Bay of
Bengal and the Indian Ocean, in-
cluding Indonesia, Thailand, Sri
Lanka, and India. The estimated
tsunami death toll ranges from
156,000 to 178,000 across 11
nations, with an additional 26,500
to 142,000 missing, most of them
presumed dead.
A tsunami survey plan was
initiated within 3 days of the
earthquake; a survey team of eight
scientists from the United States
and one from New Zealand was
formedanddispatchedtoSri
Lanka. The team was supported
by four Sri Lankan scientists. The
team surveyed both the east and
southwest coasts of Sri Lanka
duringtheperiod10January
through 14 January 2005. The
team measured maximum tsunami
heights, maximum runup heights,
inundation distances, and areas of
inundation. We also collected soil
samples from tsunami deposits, did
a limited aerial inspection along the
southwestern coast, and recorded
eyewitness accounts.
The elevations of watermarks
on buildings, scars on trees, and rafted debris
were measured as indicators of the maximum
tsunami height, which is defined relative to sea
level. Inundation distance is the distance from
the shoreline to the inland limit of tsunami
flooding, and the maximum runup height is the
elevation at the inundation distance. Every
mark used for the measurement was photo-
graphed, and its location was identified using a
global positioning satellite. Figure 1 shows the
measured maximum tsunami heights and
runup heights, adjusted for the tide levels at
the time the tsunami hit.
Eyewitnesses described one to three waves,
depending on the location, and provided
estimates of their heights. From Matara at the
southern tip to near Galle, the first wave arrived
around 03:10 U.T. (9:10 a.m. local time) as a
leading elevation wave (1) with a wave height
less than 1 m, followed 10 min later by a
second large elevation wave with wave height
up to 10 m. The leading waves were refracted
around the southern tip of the island and
reached the west coast (2). North of Galle, up
to Kaluthara, a third elevation wave with a
height up to several meters was reported near
noon, suggestive of reflection from the coast of
India or from the Maldives. On the east coast,
the first reported wave was an elevation that
rose like a tide to È1m,followedbyadepres-
sion, whereas the second elevation wave was
large and fast. On both the east and southwest
coasts, eyewitnesses reported a major recession
of hundreds of meters in horizontal length
between the first and second arrivals.
The importance of tsunami education for
coastal residents was exemplified in a small
fishing village near Galle. One of the village
residents, a merchant marine who witnessed a
tsunami in Chile two decades ago, recognized
the sea withdrawal as a tsunami indicator. He
gave warning to run to higher ground, which
nearly all his fellow residents followed. In this
village of a few hundred, only one died.
We noted a number of instances where
human development likely modified the runup
behavior of the tsunami. The Sumudra Devi, a
passenger train out of Colombo, was derailed
and overturned by the tsunami,
killing more than 1,000. In the im-
mediate area, substantial coral
mining had occurred, related to
tourism development. Tsunami
runup in the area was nearly 8 m.
In the town of Yala, tourism activi-
ties also affected the tsunami runup.
One resort, for the purpose of better
scenic views, had removed some of
the dune seaward of its hotel. The
hotel was destroyed by the tsunami.
Substantially larger water eleva-
tions and greater damage observa-
tions were found near the hotel, as
compared to neighboring areas
located behind unaltered dunes. In
essence, by removing some of the
natural coastal protection in a local-
ized area, a conduit was created
through which the tsunami energy
could flow more freely.
References and Notes
1. S. Tadepalli, C. E. Synolakis, Phys. Rev.
Lett. 77, 2141 (1996).
2. P. L.-F. Liu, Y.-S. Cho, M. J. Briggs, C. E.
Synolakis, U. Kanoglu, J. Fluid Mech.
302, 259 (1995).
3. Supported by the Earthquake Engi-
neering Research Institute, the Na-
tional Science Foundation, the United
States Geological Survey, and the
New Zealand Society for Earthquake
Engineering.
7 February 2005; accepted 1 April 2005
10.1126/science.1110730
BREVIA
1
School of Civil and Environmental Engineering,
Cornell University, Ithaca, NY 14853, USA.
2
Depart-
ment of Civil Engineering, Texas A&M University,
College Station, TX 77845, USA.
3
Department of Me-
chanical and Aerospace Engineering, Arizona State
University, Tempe, AZ 85287, USA.
4
Pacific Science
Center, United States Geological Survey, Santa Cruz,
CA 95060, USA.
5
School of Civil and Environmental
Engineering, Georgia Institute of Technology, Savan-
nah, GA 31407, USA.
6
Department of Earth and
Space Sciences, University of Washington, Seattle,
WA 98195, USA.
7
National Institute of Water and
Atmospheric Research, Ltd., Lyttelton, New Zealand.
8
Department of Civil Engineering, University of
Southern California, Los Angeles, CA 90089, USA.
*To whom correspondence should be addressed.
E-mail: plynett@tamu.edu
Elevation (m)
0
10
10 0
50 km
SRI LANKA
COLOMBO
GALLE
BATTICALOA
YALA
TRINCOMALEE
KALMUNAI
N
8N
80 E 82 E
6N
Elevation (m)
010
Elevation (m)
Fig. 1. Measured tsunami runups (blue) and maximum tsunami heights
(black). Red dots show sites of elevation measurement; areas shaded in
black are less than 10 m above sea level. The map is modified from one
by NASA/GSFC/METI/ERSDAC/JAROS and ASTER.
www.sciencemag.org SCIENCE VOL 308 10 JUNE 2005 1595
