• For the second time this year Indonesia was struck by Tsunami but this time none of the sensors of the networked warning systems in the Indian Ocean region could detect any kind of abnormal oceanic movement.
  • It was a localized tsunami which occurred due to a volcanic euption leading to mudslide on the ocean bed.
  • As there was no earthquake the sensors could not catch anything.
  • There is no technology available to detect Tsunamis occurring due to mudslides closer to the shore.
  • It is very difficult to handle localized Tsunamis and far more easier to detect one which affects the entire ocean basin on a larger area.
  • There are sensors used in mountains to alert about mudslides but sensors to detect them on the ocean beds are not yet available although scientists are continuously working on improving the models.
  • The last Tsunami which had occurred in the Indonesian island of Palu claiming many lives was triggered by an earthquake followed by “combination of sliding of a portion of landmass and mudslide in a small bay area”
  • A necessary advice was issued then by ITEWS when the quake was noticed in the sensors but none could predict the devastation that followed as there was “no unusual activity in the oceanic buoys and sea level gauges”.
  • It was a ‘strike slip’ earthquake where two land masses move one against the other parallelly which usually do not cause much displacement of water in the sea and hence, the Tsunami too will not be of that much force.
  • However, due to one portion of the island dipping into the sea and being an enclosed bay area, the Tsunami impact was greater.
  • High ocean tides too could have amplified the Tsunami impact in the latest case.
  • Ocean beds near the shore should be mapped underwater to understand the geographical features on the mud accumulation before introducing any alert warning systems.