Indonesia's earthquake system 'shaky but stable'
The Meteorological and Geophysical Agency of Indonesia (BMG) says the installation of a tsunami early warning system for the Indian Ocean is being compromised by difficulties in acquiring appropriate land.
The agency announced that it has so far installed about 70 of the planned 180 sensors required to detect the location and size of earthquakes in Indonesia.
The new system, currently under construction by BMG with help from a German research consortium, detected and sized a magnitude 7.6 earthquake last week (8 August) in 4 minutes and 38 seconds. It located the quake in 2 minutes and 11 seconds.
The older system, installed in 2005 after the Indian Ocean tsunami of December 2004, took about ten minutes to detect an earthquake and located it with less precision.
Sri Woro B Harijono, head of BMG, said the performance of the new system is a giant leap for Indonesia, especially given that it only had a single sensor in 2004 when the tsunami hit.
But despite this success, Masturyono, head of the BMG's Instrumentation and Calibration Unit told SciDev.Net that some of the sensors were having trouble collecting 'clean' data.
Some of the sensors are experiencing 'noise', he said — vibrations from vehicles that run near the station for example — so the results aren't as clear as they could be.
Sri Woro said some of the sensors had been placed in unsuitable locations because of difficulties in purchasing appropriate land.
People often increase the price of their land when they find out their properties are being targeted by BMG and international donors, she said.
As a result, equipment donated by the Japanese and German governments has been installed near airports — with vibrations caused by aircraft interfering with equipment — on the islands of Kalimantan and Sumatra. Masturyono says this is "because we can't find any other sites at a suitable price".
BMG plans to finish installation of the whole 180 sensor installations by 2008 and expects the system be in operation in the same year.Indonesia consists of 17,508 islands. It's location on the edges of the Australian, Eurasian and Pacific tectonic plates makes it the site of frequent earthquakes.