Indonesian authorities have warned residents to stay away from beaches along the Sunda Strait, saying extreme weather and volcanic activity could generate another devastating tsunami in areas where more than 420 people were killed over the weekend.
The warning came as the nation marked the anniversary of the 2004 tsunami in which 130,000 Indonesians died – most of them in Aceh – after a magnitude 9.1 quake in the Indian Ocean spawned giant walls of water that killed 230,000 across 14 countries.
“Extreme weather could increase the potential of the Anak Krakatau landslides to the sea,” said Dwikorita Karnawati, chief of Indonesia’s Meteorology, Climatology and Geophysics Agency (BMKG), referring to the volcano that has been erupting since June. “We are afraid that could trigger a tsunami.”
Scientists said satellite images showed that a 64-hectare (158-acre) chunk of the crater of Anak Krakatau collapsed after an eruption on Saturday night, sliding into the ocean to produce a deadly wave that swept beachfront homes and hotels in coastal areas of Banten Province in West Java and Lampung Province in Sumatra.
“It was a very big and fast (landslide),” Widjo Kongko, a tsunami researcher with the Indonesia Agency for the Assessment and Application of Technology (BPPT), told BenarNews on Wednesday.
“Since the collapse, I assume that the slope is now steeper and the rain has made it more fragile,” he said.
The volcano, which sits in the middle of the Sunda Strait, about 25 to 30 miles (40 to 50 kilometers) from the Java and Sumatra coastlines, remains active, authorities said, urging residents to observe a 1-kilometer (0.62-mile) “exclusion zone,” the distance from coastlines that residents must avoid.
Widjo said heavy rains could make the volcano’s crater susceptible to another collapse.
“I can't predict whether [the tsunami] would be bigger or smaller. But the risk is there,” he said. “Especially since last night the escalation of the eruption has started to be more frequent.”
Police have been patrolling the beaches, urging people to stay away from battered coastal villages. Emergency crews expect to find more bodies as they press into remote villages clobbered by the tsunami, officials said.
The death toll climbed slightly to 430 on Wednesday, with at least 159 people still missing and around 1,500 injured, according to the National Disaster Management Agency (BNPB). Almost 22,000 were left homeless, it said.
Rains hamper evacuation efforts
Soldiers and volunteers were seen carrying body bags on Wednesday as they searched along beaches cluttered by debris, local reports said.
But bad weather was hampering rescue efforts in other areas where roads had been cut off, BNPB spokesman Sutopo Purwo Nugroho told a news conference in Jakarta.
“Heavy rains make the river overflow and block access, such as in Labuan, Pandeglang Regency, Banten,” said Sutopo, referring to the place that bore the brunt of the disaster.
“Many roads that were damaged by the tsunami have now become increasingly difficult,” he said.
The government has started using helicopters to distribute aid in several areas, Sutopo said.
A state of emergency has been declared until Jan. 4 in affected areas of Banten Province to make it easier to deploy assistance, he said.
Several countries have offered assistance in the wake of the disaster, which also destroyed more than 900 houses, 73 hotels and lodging units and hundreds of boats and vehicles.
"Saddened by the loss of lives and destruction in Indonesia caused by tsunami. Condolences to the bereaved families," Indian Prime Minister Narendra Modi tweeted on Sunday. “India is ready to assist our maritime neighbor and friend in relief work,” he said.
Australian Prime Minister Scott Morrison also expressed his condolences on Monday.
“A very difficult day for our friends in Indonesia,” Morrison tweeted. “Our thoughts go out to all those who have lost loved ones, the injured and all of their families. As always we stand ready to assist as needed.”
The European Union and the United States earlier also offered their assistance.
But Sutopo on Wednesday told reporters that Indonesia could still handle relief and rescue without foreign help.
"Our national potential is sufficient to handle the Sunda Strait disaster,” he said.
It was the second time in three months that a tsunami has clobbered Indonesia. On Sept. 28, a tsunami spawned by a major quake slammed Sulawesi island, killing more than 2,000 people.
The tsunami on Saturday roared ashore with little warning, officials said, acknowledging that no alert had been sounded in advance because the nation’s warning system detects only tsunamis spawned by temblors.
Indonesia, home to about 260 million people, is located in the tectonically active Ring of Fire – an area in the basin of the Pacific Ocean – and frequently suffers earthquakes and volcanic eruptions.
On Dec. 26, 2004, about 130,000 people died in the nation’s westernmost province of Aceh when a magnitude 9.1 earthquake struck off the west coast of Sumatra, spawning a series of devastating tsunamis.