New cracks discovered at Anak Krakatau raise new landslide and tsunami fears, Indonesia

While volcanic activity continues at Indonesian Anak Krakatau, authorities said they've discovered new cracks running through the remaining island. The discovery raises fears that another potentially large-scale landslide and tsunami could be produced.

According to Dr. Dwikorita Karnawati, head of the Indonesian Meteorology, Climatology and Geophysics Agency (BMKG), two cracks appeared after the volcano's height dropped from 338 m (1 108 feet) to 110 m (360 feet) following its eruptions at the end of December 2018.

"From the latest we have seen from the air, the mountain is sloping and smoke is rising from beneath the sea water. And on the body of the mountain, we can see from the surface, there are cracks that continue to emit smoke," she said. "The cracks are certainly deep", unlike normal gaps, she added, as reported by the Straits Times.

"What we are worried about is that if there is another eruption, the cracks might connect and weaken the slope, causing part of the mountain to collapse again," Dwikorita said.

"Of course the hope is that it will not be like what happened on December 22, but we ask the public to be vigilant when they are in the 500 m (1 600 feet) zone around the coast."

The part of the volcano that could collapse currently has a volume of about 60 million m³ – smaller than the 90 million m³ of slope that slid into the Sunda Strait on December 22, displacing massive amounts of water that sent waves up to 5 m (16 feet) high crashing into densely populated areas on Sumatra and Java islands.

Nevertheless, this is quite sufficient for another very dangerous tsunami. Plus, the island is still growing.

According to Volcanic Ash Advisory issued by the Darwin VAAC at 10:24 UTC on January 5, 2019, regular volcanic ash emissions to 10 km (33 000 feet) are moving ESE. Discrete eruptions to 13.7 m (45 000 feet) moving WSW are occurring every 3 to 6 hours and dissipating quickly.

"This behavior has persisted for over 48 hours," the center said.

Alert Level for Anak Krakatau remains at 3 of 4.

Residents and tourists are not allowed to approach within 5 km (3.1 miles) of the crater.

Featured image credit: Planet Labs