Kanupriya Kapoor,
Agustinus Beo Da Costa & Gayatri Suroyo | on 8:13 PM September 30,
2018
Jakarta. Indonesia's
geophysics agency lifted a tsunami warning 34 minutes after it was first issued
following a major earthquake that sent huge waves crashing into the
northeastern coast of Sulawesi Island, killing hundreds and leaving thousands
more homeless.
The magnitude-7.5 quake and
tsunami, which hit Palu, Central Sulawesi, and further along the coastline,
killed at least 384 people. Officials said on Saturday (29/09) that the death
toll was likely to rise.
Hundreds of people had gathered
for a festival on the beach in Palu on Friday when waves as high as 6 meters smashed onshore
at dusk, sweeping many to their death.
The Meteorology, Climatology and
Geophysics Agency (BMKG) faced criticism on Saturday on social media, with many
questioning if the tsunami warning was lifted too soon.
The agency said it followed
standard operating procedure and made the call to "end" the warning
based on data available from the closest tidal sensor, around 200 kilometers from
Palu.
"We have no observation data
at Palu. So we had to use the data we had and make a call based on that,"
said Rahmat Triyono, head of the earthquake and tsunami center at the BMKG.
He said the closest tide gauge,
which measures changes in sea level, only recorded an
"insignificant," 6-centimeter wave and did not account for the giant
waves near Palu.
"If we had a tide gauge or
proper data in Palu, of course, it would have been better. This is something we
must evaluate for the future," Triyono said.
It was not clear whether the
tsunami, which officials say hammered Palu and the surrounding area at
extremely high speeds measuring in the hundreds of kilometers per hour,
occurred before or after the warning had been lifted.
"Based on the videos
circulating on social media, we estimate the tsunami happened before the
warning officially ended," Triyono said.
Indonesia sits on the Pacific
Ring of Fire and is regularly hit by earthquakes. The most devastating came on
Dec. 26, 2004, when a magnitude-9.5 quake triggered a massive tsunami that
killed around 226,000 people along the shorelines of the Indian Ocean,
including over 126,000 in
Indonesia.
Palu sits at the mouth of a
narrow bay in northeastern Sulawesi and is home to around 380,000 people. It
was hit by a tsunami in 1927 and 1968, according to the National Disaster
Mitigation Agency (BNPB).
Baptiste Gombert, a geophysics
researcher at the University of Oxford, said it was "surprising" the
quake had generated a tsunami.
Friday's quake was recorded as a
"strike-slip" event where neighboring tectonic plates move
horizontally against each other, rather than vertically, which is what usually
generates a tsunami.
"There is some speculation
that there was a landslide under the sea, which displaced a lot of water and
caused the tsunami," he said, adding that the narrow bay may have
concentrated the force of the waves as they moved toward the shore.
BNPB spokesman Sutopo Purwo
Nugroho told reporters that his team had been "preparing to send public
warnings that were easy to understand" when the tsunami warning was
"suddenly ended."
The Ministry of Communication and
Information Technology said repeated warnings were sent out to residents via
text message, but Sutopo said the quake had brought down the area's power and
communications lines and there were no sirens along the coast.
Indonesians took to social media
to question the BMKG's move to lift the tsunami warning and a failure to
release information in a timely manner.
"So upset.. the warning was
lifted.. although a tsunami happened..." Twitter user @zanoguccy said in a
direct message to the BMKG.
Jakarta Globe | Reuters
Photo: The remains of the iconic Palu IV, or Panolele Bridge, in Palu, Central Sulawesi, pictured on Sunday (30/09), two days after a magnitude-7.4 earthquake and tsunami hit the area. (Antara Photo/Akbar Todo)
Photo: The remains of the iconic Palu IV, or Panolele Bridge, in Palu, Central Sulawesi, pictured on Sunday (30/09), two days after a magnitude-7.4 earthquake and tsunami hit the area. (Antara Photo/Akbar Todo)
