Each buoy floats on the surface while tethered to the seabed, monitoring signals from a seismic sensor on the ocean floor and changes in the water level. - AFP
ANDAMAN SEA: Almost 1,000km off the Thai coast devastated by a tsunami 20 years ago, engineers lower a detection buoy into the waves -- a key link in a warning system intended to ensure no disaster is as deadly again.
On Dec 26, 2004, a magnitude 9.1 earthquake under the Indian Ocean triggered a huge tsunami with waves up to 30 metres (100 feet) high.
