EARTHQUAKE
AND TSUNAMI OF JANUARY 2, 2002 IN VANUATU
George Pararas-Carayannis
INTRODUCTION 
 On January 2, 2002 (UTC -3 January
local date), a powerful earthquake struck Vanuatu, a group of
about 80 islands in the Southwest Pacific with a population of
about 190,000 people. The earthquake caused extensive damage
in the capital, Port-Vila, (a town of about 19,400) and surrounding
areas on the island of Efate. A small tsunami was generated.
This was the most destructive event in the Vanuatu Archipelago
since the 26 November 1999 earthquake and tsunami struck the
northern island of Pentecost, a town of about 12,000 people.
The 1999 tsunami left thousands of people homeless.
THE EARTHQUAKE
The earthquake occurred
at 17:22:49 on 2 January 2002 (UTC)(or 04.22 hrs on 3 January,
local time and date). Its magnitude was 6.3mb (7.5MS) and its
focal depth about 21 km. The epicenter was at at 17.78S, 167.88E
(USGS), approximately 45 km West of of Port Vila. A
number of aftershocks were recorded.
TECTONIC SETTING
 The
entire region where Vanuatu island group is located is characterized
by high volcanic and seismic activity and is part of what is
often referred to as the " Pacific Rim of Fire" - an
area notorious for frequent earthquakes and volcanic eruptions.
This region of the Southwest Pacific Ocean is presently responsible
for about ten per cent of the total energy released by earthquakes
in the world.
 The 2 January 2002 earthquake
occurred along a zone where tectonic plate convergence and subduction
take place, as the Pacific tectonic plate submerges beneath the
Australian plate. In the Vanuatu area this process of subduction
has formed the New Hebrides Trench and is the cause of major
earthquakes and locally destructive tsunamis. The tectonic plates
move at speeds averaging between 1 cm and 10 cm per year. The
Australian plate also shares boundaries with the Philippine Plate,
the Indian Plate, the Somali Plate, the Eurasian plate and the
Antarctic plate.
THE TSUNAMI
Historically only
local tsunamis are generated by earthquakes in the region. The
quake generated a local tsunami. It took 14 minutes after the
quake for the first wave to reach the Port Vila tide gauge station,
the closest to the earthquake's origin. The maximum recorded
tsunami wave was 0.8 m (trough to crest). The average period
was about 11 minutes.
However, as with the
November 1999 event, the Port Vila gauge tsunami recorded height
does not represent the maximum runup observed elsewhere in the
harbor. According to eyewitness reports the maximum tsunami runup
at different parts of PortVila , was about 3.0 meters - large
enough to cause some damage. However most of the damage was caused
by the earthquake.
A large aftershock
on the following day generated another small local tsunami, which
was recorded by the Port Vila tide gauge to be less than 10 cm.
DEATH TOLL AND
DAMAGES
 Several people were injured but
there were no reported deaths. Fearing a tsunami hundreds of
residents had fled to higher ground. Damage at Port Vila and
other areas on Efate Island was widespread but was caused primarily
by the earthquake effects and landslides. Buildings in the business
district of the town were damaged and shops had broken windows.
Ground liquifaction was responsible for most of the damage to
homes, buildings, structures and embankments. Three bridges were
reported damaged or destroyed.
Return to
Return to
 
Links to other
Pages
Now available
from Amazon, Barnes and Noble and other major bookstores. A signed
by the author copy can be also ordered by contacting directly
by email Aston
Forbes Press.
Other
Miscellaneous Non-technical Writings
(©) Copyright
1963-2007 George Pararas-Carayannis / all rights reserved / Information
on this site is for viewing and personal information only - protected
by copyright. Any unauthorized use or reproduction of material
from this site without written permission is prohibited.
|