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umerous tremors have been recorded around Anak Krakatau in the Sunda Strait, leading authorities to warn the public against getting too close to the famous volcano, according to an official.

“Data recorded at a monitoring post on Oct. 3 shows that 5,800 tremors came from the volcano [that day],” an official at the Anak Krakatau volcano monitoring post in Cinangka, Serang, Banten, Anton S. Pambudi, said on Tuesday as quoted by Antara news agency.

The amount of tremors on Monday dropped slightly from a peak of more than 6,000 recorded
on Sunday.

“We urge the public to avoid [Anak Krakatau] because it is dangerous,” Anton said.

In Bandung, the Volcanology and Geological Disaster Mitigation Center (PVMBG) raised the status of Mount Anak Krakatau to alert, the third of four alert levels, on Sept. 30. The elevated status is supported by seismic data that has logged up to five quakes in a period of one minute.

“This is the most activity recorded. Based on the history of the volcano, there have never been 1,503 tremors within six hours,” PVMBG head Surono said at his office in Bandung on Monday.

Despite being recorded by the seismograph, the intensity of the quakes has never exceeded a 2 on the Richter scale, so Surono said the volcano’s status must be raised.

For comparison, he cited a decision-making case to raise Mount Kelud’s status in 2007. Then, PVMBG raised its status from active normal, or level 1, to alert, or level 2, based on seismic data that only recorded four times.

“We raised the status from standby to alert because we received seismic data 10 times in one day,”
he said.

According to Surono, the temperature of the water surrounding the 315-meter-tall volcano could rise along with the increased activity. The rise in temperature attracts plankton and fish around it.

“Fish will gather and fishermen will certainly go there, so we have determined that a 2-kilometer radius should be free of human activities,” he said.

Surono has urged residents living on the coast in Banten and Lampung not to panic about tsunami rumors in the event of an eruption.

He said the volcano, formed after its parent erupted in 1883, remained active and had erupted every year until 1950, after which it erupted sporadically once every two to four years.

The eruptions cause it to continuously vent energy. Molten material discharged from the volcano accounts for its growth to 315 meters above sea level in only 75 years.

“It is impossible for it to erupt like its parent did in 1883. Its magma reservoir is destroyed,” Surono said, adding that an eruption would be unlikely to trigger a quake and tsunami in the Sunda Strait.

The PVMBG set Mount Anak Krakatau’s level 2 status on Oct. 31, 2009. Surono said activities in Anak Krakatau had not stopped since 2007.

The threat of danger from an eruption is predicted to cover a 2-kilometer radius from its crater. “The risks include bursts of volcanic material and lava flows,” he said.