Questions still
abound about what caused the tsunami.
Tsunami hit beaches
in Lampung and Banten, killing at least 168 and injuring 750.
The lack of a
powerful earthquake or strong volcanic eruption caused the BMKG to initially announce that …
the waves did not constitute a tsunami but
were instead caused by high tide.
“The BMKG has not
recorded any earthquake occurring tonight.
What happened in
Anyer [Banten] and the surrounding area was not a tsunami, but a tidal wave.
There is also a full
moon tonight, which causes high tidal waves. Stay calm,”
the BMKG stated in a
tweet that has since been deleted.
It was only
discovered hours later that the tide was three meter high, and potentially
caused by volcanic activity of Mount Anak Krakatau.
Krakatau is located
in the middle of the Sunda Strait.
The strait divides Sumatra and Java.
She confirmed there
had been a tsunami but no tectonic activity in the area..
They suspected the
tsunami was caused by an eruption from the volcano.
“At 21:03 [Saturday
night] Krakatau erupted again and damaged nearby seismometers, but the Sertung
Seismic Station recorded continuous tremors.
She added that
seismic sensors in Cigeulis, Banten also recorded seismic activity lasting
around 24 seconds.
It was still looking
into the connection between the Anak Krakatau eruption and the tsunami.
The volcano had
been active since June and stronger eruptions from the mountain had not
resulted in tsunamis.
“To trigger a
tsunami that large, there needs to be a massive landslide that falls into the
sea […]
and that requires a
large amount of energy, which has not been detected by seismographs in volcanic
observation posts.
A monitoring station
of the volcano in Anyer Beach.
The station is
located about 40 kilometers away from Anak Krakatau.
The station recorded
lava eruption to the southern part of the mountain, but the eruption
had been deemed too minor to cause a tsunami.
There were two
possible causes of the tsunami: a landslide caused by the Anak
Krakatau eruption or a sudden change in meteorological conditions.
He added that both
theories had their limitations.
“Right now it’s
still a blind debate because we have limited information, only the tide gauge
data from four stations.
“If the tsunami was
caused by a landslide from the eruption, we would expect the four stations to
record the waves at around the same time, but
The tide gauge at
Panjang Port recorded it significantly later than the other stations,”
The three islands
surrounding Anak Krakatau should have blocked any waves resulting from an
eruption.
Meteorological
factors could have also caused the tsunami, but …
BMKG data do not
show any sign of sudden changes in air pressure that would be required to
trigger such a “meteo-tsunami.”
“But the data does
show that there were very high wind speeds.
This could have
combined with the landslide to exacerbate the size of the tsunami.
Authorities were
continuing efforts to trace survivors and retrieve bodies of the deceased as of
Sunday.
As of Sunday at 1
p.m. the agency had recorded at least 168 dead and 750 injured, while
35 remained missing.
Hundreds of houses
and other buildings were destroyed.
Based on currently
available data, he felt that an underwater landslide was the best explanation
for the tsunami.
“The Anak Krakatau
eruption probably caused a tremor that resulted in a landslide on an underwater
slope that in turn triggered the tsunami.
While the volcano’s
activity had not shown any significant increase in intensity in recent days,
the repeating tremors may have weakened one of the underwater slopes and
eventually caused a landslide.
“This is still interpretation,
we need more information
to confirm the real cause,”.
''
Questions still abound about what caused the tsunami that hit beaches in Lampung and Banten on Saturday night, killing at least 168 and injuring 750.
The lack of a powerful earthquake or strong volcanic eruption caused the Meteorology, Climatology and Geophysics Agency (BMKG) to initially announce that the waves did not constitute a tsunami but were instead caused by high tide.
“The BMKG has not recorded any earthquake occurring tonight. What happened in Anyer [Banten] and the surrounding area was not a tsunami, but a tidal wave. There is also a full moon tonight, which causes high tidal waves. Stay calm,” the BMKG stated on its Twitter account on Saturday night, in a tweet that has since been deleted.
It was only discovered hours later that the tide was three meter high, and potentially caused by volcanic activity of Mount Anak Krakatau, which is located in the middle of the Sunda Strait that divides Sumatra and Java.
BMKG head Dwikorita Karnawati confirmed there had been a tsunami but no tectonic activity in the area, and that they suspected the tsunami was caused by an eruption from the volcano.
“At 21:03 [Saturday night] Krakatau erupted again and damaged nearby seismometers, but the Sertung Seismic Station recorded continuous tremors,” she said in a statement on Saturday.
She added that seismic sensors in Cigeulis, Banten also recorded seismic activity lasting around 24 seconds.
The Center for Volcanology and Geological Hazard Mitigation (PVMBG) said it was still looking into the connection between the Anak Krakatau eruption and the tsunami. It said the volcano had been active since June and stronger eruptions from the mountain had not resulted in tsunamis.
“To trigger a tsunami that large, there needs to be a massive landslide that falls into the sea […] and that requires a large amount of energy, which has not been detected by seismographs in volcanic observation posts,” the center said in a press statement.
A monitoring station of the volcano in Pasauran, Anyer Beach, which is located about 40 kilometers away from Anak Krakatau, recorded lava eruption to the southern part of the mountain on Saturday night, but the eruption had been deemed too minor to cause a tsunami.
Tsunami expert Ahmad Muhari said there were two possible causes of the tsunami: a landslide caused by the Anak Krakatau eruption or a sudden change in meteorological conditions, but added that both theories had their limitations.
“Right now it’s still a blind debate because we have limited information, only the tide gauge data from four stations,” he told The Jakarta Post on Sunday.
“If the tsunami was caused by a landslide from the eruption, we would expect the four stations to record the waves at around the same time, but the tide gauge at Panjang Port in Lampung recorded it significantly later than the other stations,” he said, adding that the three islands surrounding Anak Krakatau should have blocked any waves resulting from an eruption.
Meteorological factors could have also caused the tsunami, Ahmad said, but BMKG data do not show any sign of sudden changes in air pressure that would be required to trigger such a “meteo-tsunami.”
“But the data does show that there were very high wind speeds and this could have combined with the landslide to exacerbate the size of the tsunami,” he said.
Authorities were continuing efforts to trace survivors and retrieve bodies of the deceased as of Sunday.
National Disaster Mitigation Agency (BNPB) spokesperson Sutopo Purwo Nugroho through his Twitter handle @Sutopo_PN said that as of Sunday at 1 p.m. the agency had recorded at least 168 dead and 750 injured, while 35 remained missing. Hundreds of houses and other buildings were destroyed.
Indonesian Geologists Association (IAGI) chairman Sukmandaru said that based on currently available data, he felt that an underwater landslide was the best explanation for the tsunami.
“The Anak Krakatau eruption probably caused a tremor that resulted in a landslide on an underwater slope that in turn triggered the tsunami,” he told the Post on Sunday.
He said that while the volcano’s activity had not shown any significant increase in intensity in recent days, the repeating tremors may have weakened one of the underwater slopes and eventually caused a landslide.
“This is still interpretation, we need more information to confirm the real cause,” he said. (wit)
--
People have criticized the Meterology, Climatology and Geophysics Agency (BMKG) on social media for its initial handling of the Sunda Strait tsunami that hit beaches in Lampung and Banten on Saturday night.
The BMKG initially announced on Saturday night that there had been a tidal wave in the Sunda Strait, refuting tsunami claims.
“The BMKG has not recorded any earthquake occurring tonight. What happened in Anyer and the surrounding area was not a tsunami, but a tidal wave. There is also a full moon tonight, which causes high tidal waves. Stay calm,” the BMKG stated on its Twitter account on Saturday night. The tweet also included a "sunglasses" emoji.
The agency apologized for the tweet shortly after, saying that the emoji was "inappropriate."
Not long after, the BMKG tweeted that a tsunami had indeed occurred, saying that it was suspected to have been caused by volcanic activity from Anak Krakatau.
A similar statement was made by National Disaster Mitigation Agency (BNPB) spokesperson Sutopo Purwo Nugroho based on the BMKG's information in a now deleted tweet.
However, Sutopo retracted his statement on Sunday morning through a tweet, apologizing for the wrong information he had spread the night before.
“My apologies regarding my previous tweet which claimed there had been a tidal wave instead of a tsunami. There have been changes of information in accordance with new data and analysis. There was indeed a tsunami in the Sunda Strait. We are referring to the BMKG,” his tweet says.
The BMKG had previously been heavily criticized for allegedly ending the tsunami warning too early when high waves hit various areas in Central Sulawesi in October.
==
At least 20 people have been killed and more than one hundred injured in a tsunami in Indonesia that may have been caused by a volcano known as the "child" of the legendary Krakatau, officials said early Sunday.
Dozens of buildings were destroyed by the wave, which hit beaches in Lampung and Banten about 9.30 pm local time (1430 GMT) on Saturday, national disaster agency spokesman Sutopo Purwo Nugroho said in a statement.
"20 people died, 165 people were injured and two people were missing in three regions," Nugroho said in a statement.
Authorities say the tsunami may have been triggered by an abnormal tidal surge due to a full moon and an underwater landslide following the eruption of Anak Krakatau, which forms a small island in the Sunda Strait between Java and Sumatra.
Indonesia's geological agency was investigating the cause, Nugroho said, adding the death toll would likely increase.
Anak Krakatau is a small volcanic island that emerged from the ocean half a century after Krakatau's deadly 1883 eruption.
Indonesia, one of the most disaster-prone nations on earth, straddles the so-called Pacific 'Ring of Fire', where tectonic plates collide and a large portion of the world's volcanic eruptions and earthquakes occur.
The country regularly experiences deadly earthquakes, including most recently in the city of Palu on Sulawesi island where a quake and tsunami killed thousands of people.
Anak Krakatau is one of 127 active volcanoes which run the length of the archipelago.
;;
At least 222 people have died as a result of a tsunami that hit beaches of Lampung and Banten on Saturday night, the National Disaster Mitigation Agency (BNPB) announced on Sunday.
As of 4:00 p.m., the BNPB recorded 222 deaths, while 843 people were injured and 28 were missing.
"The material damage includes 556 houses, nine hotels, 60 [eateries] and 350 ships or boats that were heavily damaged," BNPB spokesperson Sutopo Purwo Nugroho said in a statement on Sunday. "There were no foreign victims, all are Indonesian citizens."
He said that the number of casualties was expected to increase, because not all victims had been evacuated and not all community health centers had reported the number of patients they were treating.
Pandeglang regency in Banten was the worst hit area, with 164 fatalities, 624 people injured, and two people missing. Eleven casualties were recorded in Serang regency, Banten, while 48 people died in Lampung Selatan regency.
"Heavy equipment has been deployed to help with the evacuation," Sutopo said. "At the moment, five excavators, two loaders, two dump trucks and six water tankers are in the field."
He added that the number of evacuees was also still being estimated.
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