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A PRELIMINARY ANALYSIS OF THE INFLUENCE OF
SUMATRAN TSUNAMI ON INDIAN OCEAN
CHL-
AND SST
a
DANLING TANG
†,∗
, B. SATYANARAYANA
†
, HUI ZHAO
†
andR.P.SINGH
‡
†
Laboratory for Tropical Marine Environmental Dynamics
South China Sea Institute of Oceanology
Chinese Academy of Sciences
Guangzhou-510301, P. R. China
‡
Department of Civil Engineering, Indian Institute of Technology
Kanpur-208016, India
∗
lingzistdl@126.com
The massive earthquake off the northern Sumatran coast (Indonesia) on Decem-
ber 26, 2004 produced the largest trans-oceanic tsunami. Besides landform
destruction and changes, the alterations produced the phenomena of aquatic
environments, highlighting that ecosystem responses are also important. In this
paper, we present pre- and post consequences of the tsunami on spatial and tem-
poral distribution of Chlorophyll-
a
(Chl-
a
), the vital element of marine ecosys-
tem and primary production. Our analysis based on satellite data (MODIS)
indicated that levels of Chl-
increased prior (December 2-22) to the tsunami,
and dispersed afterwards along with the drift of current. The time-series data
(daily and 8-day intervals) between 2002 and 2005 (October-January) also
revealed a similar trend and indicated an inverse relationship between Chl-
a
a
and Sea Surface Temperature (SST). Further detailed analyzes have shown that
the distribution of Chl-
is influenced also by other environmental factors such
as wind, upwelled water and circulation in the Indian Ocean.
a
1. Introduction
The term “tsunami” is used to describe a series of waves that travel across
the ocean with exceptionally long wavelengths.
1
,
2
The case in this study was
a subduction
3
earthquake on December 26, 2004 off the northern Suma-
tran coast (Indonesia).
4
-
6
According to United States Geological Survey
(USGS),
7
the epicentre of earthquake was located near 3.3
◦
N, 95.95
◦
E
with a magnitude of 9.0 and focal depth of 10 km at 00:58:53 UTC. It
was presumed that approximately a trillion tonnes of water was displaced
and driven towards Southeast Asia's coastline in long, low amplitude waves
travelling up to 900 km/h.
8
Although, the velocity of waves slows down
15
