Another tsunami could strike Indonesia, experts have warned, after a powerful wave caused by a volcanic eruption killed hundreds when it swallowed coastal settlements, taking earthquake-focused disaster monitors by surprise.

- What caused the tsunami? -

While tsunamis are often triggered by earthquakes, in this case experts believe the deadly waves were generated by an eruption of the Anak (or "child of") Krakatoa volcano, which could have caused a large undersea landslide or flow of molten rock into the water.

The tsunami "appears to have been caused by an underwater collapse" of part of the volcano, said David Rothery, a professor of planetary geosciences at Britain's Open University.

Anak Krakatoa is an island that emerged around 1928 in the crater left by Krakatoa, whose massive 1883 eruption killed at least 36,000 people.

The tsunami that struck on Saturday was the third natural disaster to hit Indonesia in six months.

The country has 127 active volcanoes and lies on the Pacific Ocean's "Ring of Fire" where earthquakes and volcanic eruptions are frequent.

- Why was it so deadly? -

Anak Krakatoa, located in the Sunda Strait between Java and Sumatra islands, is close to densely populated areas.

The volcano has been particularly active since June, noted Jacques-Marie Bardintzeff at the University of Paris-South.

"We were helpless given how sudden" the event took place, Bardintzeff said. "The time between cause and effect was a few dozen minutes, which was too short to warn the population."

The killer wave struck at night, sweeping across tourist beaches and low-lying settlements on both sides of the Sunda Strait and catching both residents and disaster monitors totally unawares.

"Signs that a tsunami was coming weren't detected and so people did not have time to evacuate," said Indonesia's disaster agency spokesman Sutopo Purwo Nugroho, who blamed vandalism, technical problems and limited budgets for the lack of warning buoys.

But the Open University's Rothry said such buoys, normally positioned to monitor earthquakes at underwater tectonic plate boundaries, would still have had limited efficacy.

"Even if there had been such a buoy right next to Anak Krakatoa, this is so close to the affected shorelines that warning time would have been minimal given the high speeds at which tsunami waves travel."

Simon Boxall of Southampton University said the region was in spring tide, "and it would appear that the wave hit some of the coastal areas at the highest point of this high tide, exacerbating the damage done".

While the tsunami was relatively small, Richard Teeuw, a disaster risk reduction expert at the University of Portsmouth in England said: "Such waves -- laden with debris -- can be deadly for coastal communities, especially if there is no warning."

- Could more tsunamis be coming? -

"Devastating tsunami caused by volcanic eruptions are rare; one of the most famous (and deadly) was caused by the eruption of Krakatoa in 1883," Teeuw said.

"The likelihood of further tsunamis in the Sunda Strait will remain high while Anak Krakatoa volcano is going through its current active phase because that might trigger further submarine landslides," he said.

Sonar surveys would now be needed to map the seafloor around the volcano, but "unfortunately submarine surveys typically take many months to organise and carry out," he added.

Bardintzeff warned "we must be wary now that the volcano has been destabilised".

Hunt for survivors as Indonesian tsunami death toll climbs to 373
Carita, Indonesia (AFP) Dec 24, 2018 - Dozens of filled body bags were hauled away from buildings flattened by Indonesia's volcano-triggered tsunami Monday, as the death toll climbed to 373 and search teams pushed on with the grim hunt for corpses.

Rescue teams used their bare hands, diggers and other heavy equipment to haul debris from the stricken area around the Sunda Strait, as thousands were evacuated to higher ground.

Experts warned that more deadly waves could slam the devastated region after Saturday night's disaster, as questions swirled over why the killer wave caught a disaster-prone country's monitors completely off guard.

The powerful tsunami swept over popular beaches on southern Sumatra and western Java and inundated tourist hotels and coastal settlements.

Some 1,459 people were injured with another 128 missing, disaster agency spokesman Sutopo Purwo Nugroho said, giving an updated toll late Monday.

"The lack of a tsunami early warning system caused a lot of victims because people did not have the time to evacuate," he said.

Hundreds of buildings were destroyed by the wave that left a tangled mess of corrugated steel roofing, timber and rubble at Carita beach, a popular spot for day-trippers on the west coast of Java.

Beachside cottages at one resort were flattened while the dining room's mud-caked floor was strewn with smashed chairs and tables, utensils and spilled cups of ice cream.

In the lobby, a Christmas tree remained standing, surrounded by fallen holiday ornaments and toppled-over flower pots.

"The military and police are searching the ruins to see if we can find more victims," said Dody Ruswandi, a senior official at the disaster agency, adding that the rescue effort was likely to last a week.

- 'No time to evacuate' -

Indonesia's disaster agency initially said there was "no tsunami threat" even as the wave crashed ashore.

It was later forced to issue a correction and an apology as it pointed to the area's lack of early warning systems.

Unlike those caused by earthquakes, which usually trigger alert systems, volcano-triggered tsunamis give authorities very little time to warn residents of the impending threat.

Experts say Saturday's disaster was most likely caused by a moderate eruption of the Anak Krakatoa volcano in the Sunda Strait that triggered either a large and very fast moving flow of molten rock into the sea or a sudden and massive submarine landslide -- both would displace large amounts of water, resulting in a tsunami.

The evidence so far suggested that a section of the volcano collapsed and slid into the ocean, triggering a tsunami, said Dwikorita Karnawati, head of Indonesia's meteorological agency.

It was the third major natural disaster to strike Indonesia in the space of six months, following a series of powerful earthquakes on the island of Lombok in July and August and a quake-tsunami in September that killed around 2,200 people in Palu on Sulawesi island, with thousands more missing and presumed dead.

It also came less than a week before the 14th anniversary of the 2004 Boxing Day tsunami, one of the deadliest disasters in history that killed some 220,000 people in countries around the Indian Ocean, including some 168,000 Indonesians.

The vast archipelago nation is one of the most disaster-hit nations on Earth due to its position straddling the so-called Pacific Ring of Fire, where tectonic plates collide.

- 'Saw the water coming' -

In devastated Sukarame village, Sunarti waded through knee-deep water as she searched for belongings outside her destroyed house -- and waited for aid to arrive.

"There's been no help at all so far," the 61-year-told AFP from the flattened hamlet.

"Some people are starving."

Survivor Ade Junaedi recounted seeing nature's fury firsthand.

"It happened very quickly," he said.

"I was chatting with a guest at our place when my wife opened the door and she suddenly screamed in panic. I thought there was a fire, but when I walked to the door I saw the water coming."

Richard Teeuw, a geohazard expert from the University of Portsmouth in England, said the eruption and landslide may well have destabilised the volcano, heightening the risk of another tsunami.

"The likelihood of further tsunamis in the Sunda Strait will remain high while Anak Krakatoa volcano is going through its current active phase because that might trigger further submarine landslides," Teeuw said.

Dramatic video posted on social media showed a wall of water suddenly crashing into a concert by pop group "Seventeen" -- hurling band members off the stage and then flooding into the audience.

At least two band members were killed along with its manager and a crew member, while Indonesian media said the band's missing drummer was found dead Monday.

The surviving lead singer's wife is missing. Front man Riefian Fajarsyah posted a picture online of he and his wife kissing in Paris with the Eiffel Tower in the background.

"Today is your birthday -- I want wish you a happy birthday in person. Come home soon, honey," he wrote in the caption of the photo, which was posted Sunday.

Anak Krakatoa, which forms a small island in the Sunda Strait between Java and Sumatra, emerged around 1928 in the crater left by Krakatoa, whose massive eruption in 1883 killed at least 36,000 people and affected global weather patterns for years.

Related Links
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Hunt for survivors as Indonesian tsunami death toll tops 280
Carita, Indonesia (AFP) Dec 24, 2018
Indonesian rescuers raced to find survivors Monday after a volcano-triggered tsunami killed at least 281 people, with experts warning the devastated region could be slammed by more deadly waves. Rescue teams used their bare hands, diggers and other heavy equipment to haul debris from the stricken area around the Sunda Strait, as thousands were evacuated to higher ground. The powerful tsunami struck without any warning on Saturday night, sweeping over popular beaches of southern Sumatra and the w ... read more