Authorities in Indonesia will set up a special system near Mount Krakatau to trigger early tsunami warning signals if tidal waves occur.
The buoy and cable base tsunameters (CBT) will be installed together in the water near Mount Krakatau.
Two other buoys will also be installed along the west coast of Sumatra Island, waters off Bengkulu province, and along the south coast of Java Island.
"The CBT is a cable with a sensor placed on seafloor to gauge the extreme change of pressure underwater which indicates a tsunami. The sensor will send the data through a satellite to the receiver post onshore," an official from the Indonesian agency for the assessment and application of technology (BPPT) explained.
The move comes after the December 2018 tsunami triggered by the eruption of Anak Krakatau volcano left over 400 people dead and more than 14,000 others injured.