A new undersea mud volcano is erupting off Aceh following a massive earthquake there earlier this month, a 15-member geological assessment team sent to the province has confirmed.
Officials, however, were quick to add that the new volcano was unlikely to pose a threat.
“Based on our visual observations, the volcano is not dangerous. But we are going to conduct an in-depth analysis this week of the samples we collected, so we will have a definitive answer,” said Ridwan Djamaluddin, director for mitigation and regional development at the Agency for the Assessment and Application of Technology (BPPT).
Ridwan said the volcano, located near Banyak Island off the coast of Singkil district, was currently 30 meters in diameter and eight meters tall.
Local residents have claimed the seabed in the area has risen dramatically since the 7.2-magnitude earthquake on April 7.
Before the quake, the waters around Gosong Turak reef were 20 meters to 30 meters deep, but now were just five, said Mufliadi, a Banyak Island resident.
Villagers have reported seeing an undersea fissure spewing out mud and rocks, and are worried an undersea volcano could be forming, he said.
Mufliadi said the phenomenon was first noted a week after the earthquake by a fisherman who had been trawling for sea cucumbers in the waters around Pailana Island, just off Banyak Island.
“He was shocked and came back to tell us what he had seen because that site is a prime fishing spot for local fishermen,” but now there are no fish there, Mufliadi said.
The geologists, who traveled to the province last week at the request of Aceh Governor Irwandi Yusuf, confirmed there were no fish in the area.
“The fish around the area have gone and the water has become turbid,” Ridwan said, adding that the water temperature had risen from 27 degrees Celsius to 32 degrees.
To prevent worried residents from fleeing the area, Ridwan said the team would work quickly to analyze the samples it had collected.
“We still have to conduct an in-depth analysis of this,” he said, adding that if the mud and rocks contained methane, it would be dangerous.