Tsunami has “attacked” Indonesia twice in 2018. Without any preparation and warning signs, the tsunami came and devoured thousands of lives as happened in Central Sulawesi in September and then Banten and Lampung last week. This disaster seems to be a warning for the government to fix its early warning system, so it will no longer cause many casualties.
On Saturday night (12/22), around 9:30 PM (West Indonesia Time/WIB), a three-meter high tsunami wave destroyed hundreds of buildings and washed away thousands of people in Banten and Lampung. It came suddenly without any early notice and predictions from the Meteorology, Climatology and Geophysics Agency (BMKG) or the National Disaster Mitigation Agency (BNPB).
In fact, it is unfortunate that the two agencies initially stated there were no tsunamis in Sunda Strait. Without taking steps to ascertain it first, they asserted that it was only a tidal wave – a normal phenomenon that occurs during a full moon.
In Its twitter account, BMKG stated there was no earthquake causing tsunami. “What happened in Anyer and its surroundings was not a tsunami, but a tidal wave. Moreover, the full moon phenomenon occurred tonight,” the agency said through its official account @InfoBMKG on Saturday night (12/22).
BNPB Spokesperson Sutopo Purwo Nugroho also stated the same thing. He referred to the BMKG’s report that there were no large earthquakes that could cause tsunamis either in the Sunda Strait or the Indian Ocean. The tidal wave phenomenon also has nothing to do with the eruption of Anak Krakatau, which occurred since the morning. The eruption was relatively small and did not cause an increase in sea waves.
“The phenomenon was not a tsunami. Currently, there was no tsunami in the territory of Indonesia,” Sutopo said on Twitter, which was posted through BNPB official account @BNPB_Indonesia on Saturday night.
A few hours later, the two agencies corrected their statements. Without expressing an apology, BMKG deleted its previous statement on Twitter and then issued a new release stating the existence of tsunamis in Anyer and Lampung. The BMKG also stated that it was difficult to confirm it because no earthquake had occurred before the tsunamis.
Sutopo eventually apologized for the changes in information from BMKG in accordance with the latest analysis. The tsunami that hit Pandeglang Regency, Serang, South Lampung and Tanggamus was probably due to a combination of two natural factors, which are the eruption of Anak Krakatau and the tidal wave due to the emergence of a full moon.
Three months earlier, earthquake and tsunami also hit Central Sulawesi. Around 2,101 people have been killed, 4,438 injured, and 1,373 missing. The early warning sign was actually active before tsunami came, but BMKG turned it off as the agency perceived the situation was already safe. Moments later, the tsunami really came.
According to the BMKG Head Dwikorita Karnawati, the tsunami early warning sensor in Palu failed to send a signal. The device worked, but the earthquake damaged the communication network. The BMKG can only analyse the potential of tsunamis from the early warning sensor in Mamuju that was still functioning.
The number of tsunami victims can actually be minimised if the early warning system works well. At least, the public can get advance information about the possibility of a tsunami in their area, so they have the chance to evacuate.
The early warning system is not running optimally due to limited funds and improper equipment. According to the BMKG Earthquake and Tsunami Mitigation Head Tiar Prasetya, there were no tsunami early warnings in Banten and Lampung because there were no earthquakes that night. “Indeed, there were no warnings because BMKG noted that no earthquakes have occurred that night,” Tiar said in Jakarta, Tuesday (12/25). So far, BMKG's predictions regarding the potential of tsunamis have indeed referred to earthquakes, as happened in Central Sulawesi.