▲ Photo: Jeju World Heritage Office

The existence of a crater near Seongsan Ilchulbong Peak in Jeju, which had only been academically hypothesized, has been scientifically proven.

According to the Jeju World Heritage Office, following the Seongsan Ilchulbong Submarine Geological Survey and Value Discovery Project funded by the Cultural Heritage Administration, traces of a circular crater were confirmed on the seabed near Seongsan Ilchulbong Peak. The survey was conducted using a multi-beam echo sounder to precisely survey the underwater topography of the three-kilometer radius surrounding Seongsan Ilchulbong.

The result shows traces of a 600m-wide circular crater at a depth of 10m, about 500 m southeast of Seongsan Ilchulbong Peak. A band-shaped topographical structure was also observed around the crater. Researchers speculated that traces were left by the erosion of the outer ring of the crater.

Seongsan Ilchulbong Peak is a tuff cone formed by hydrovolcanic activity when hot magma comes into contact with shallow water. The volcanic ash layer was eroded by waves, giving it its present form.

Studies have already been conducted on existing terrestrial elements, but not as sufficiently on the topography and geology of the seafloor.

“We will reproduce the formative history of hydrovolcanic activities by inferring the initial topography and distribution range of Seongsan Ilchulbong at the time its formation through the analysis of seabed topography and offshore drilling,” said Yun Seok-hun, a senior researcher of the project and professor at Jeju National University.

“Seongsan Ilchulbong Peak erupted 5,000 years ago, and the newfound crater was created before that,” said Ki Jin-seok, curator at the World Heritage Office. “The exact period of formation will be confirmed through drilling,” he added.