Earthquake altered Nias' position

Earthquake altered Nias' position

The massive quake that hit Nias island on March 28 has altered
its position.

Based on a LIPI study, the island shifted 12 meters westwards,
away from Sumatra, a few seconds after the quake.

Telo island in the Batu islands moved 70 centimeters farther
away from Sumatra.

Danny said that before the quake, Nias island was moving
toward Sumatra at a rate of 3 centimeters per year due to the
depressing of the continental plate by the oceanic plate, at the
end of which Nias island is located. The pressure was released
during the quake, which resulted in Nias shifting away from
Sumatra.

A joint team from LIPI's Geotechnology Research Center and the
California Institute of Technology has been conducting
seismological research on the west coast of Sumatra since 1993.
The movements of tectonic plates are measured by the Global
Positioning System (GPS).

The team has installed 19 GPS monitors in 19 locations on
Sumatra's west coast from Muko-Muko in Bengkulu to Aceh. Some
have been installed on islands off the west coast of Sumatra,
from Enggano in Bengkulu to Simeuleu in Aceh.

The team installed nine telemetric devices connected to the
GPS last week to obtain satellite data so that they do not have
to actually visit the GPS locations any longer to recover the
data.

In addition, the team has also positioned nine seismographs at
those locations and five accelerographs on Mentawai and Nias, and
in the Simeuleu islands.

An accelerograph is a device used to measure and record
massive quakes. A seismograph can usually only record seismic
tremors of up to 7 magnitude, but an accelerograph is able to
record tremors of 9 magnitude and over.

--Sfofiardi Bachyul Jb