Japan's Kikai Caldera hosts giant lava dome, survey confirms

Feb. 9 (UPI) -- A trio of surveys carried out by scientists with the Kobe Ocean Bottom Exploration Center in Japan has confirmed the presence of a giant lava dome in the Kikai Caldera, a mostly submerged caldera located south of Japan's main islands.

Kikai is one of Earth's largest post-caldera volcanoes. The latest research -- published Friday in the journal Science Advances -- a giant lava dome has developed since the volcano's massive eruption some 7,300 years ago.

KOBEC researchers used a variety of instruments and analysis methods to study the caldera and its internal structure. Scientists combined the observations of underwater robots and the results of rock sample analysis with data collected by seismographs and electromagnetometers.

The results of the survey suggest the makeup of Kikai's lava dome is similar to the contents of the post-caldera volcano found on the nearby island of Satsuma Iwo-jima.

"It is possible that currently a giant magma buildup may exist under the Kikai Caldera," scientists wrote in a news release.

Scientists determined there is a 1 percent risk of the magma inside Kikai's lava dome erupting during the next century. If the dome were to erupt, Japan's archipelago could experience the sudden release of 40 cubic kilometers of lava.

The nature of the dome's internal plumbing isn't yet clear. In follow-up surveys, scientists plan to conduct high-resolution imaging of the dome's deep-lying inner structures using seismic and electromagnetic methods. The future surveys will give scientists a better idea of how and when the caldera and its lava dome might erupt in the future.