SAPPORO – More powerful eruptions and flows of rocks and lava may occur anytime between the next few days and two weeks on the western side of Hokkaido’s Mount Usu, seismologists said Wednesday.
A subcommittee of the government’s Coordinating Committee for the Prediction of Volcanic Eruptions announced that “there was a high possibility” that such heightened activity could happen within that time frame.
Mudslides and a new column of volcanic smoke on the southeastern flank of Mount Usu were sighted Wednesday morning by the Meteorological Agency.
The agency said it has confirmed that new volcanic activity is taking place at about 5:20 a.m. near the Toyako hot springs resort at the foot of the 732-meter-high mountain.
Volcanologists said they believe the smoke is coming from a new crater that bad weather had prevented them from seeing until Wednesday morning.
“We could not confirm it because of the weather,” an agency official said, “but we believe this is an eruption that is coming from new craters.”
The official was quick to add, however, that this development does not necessarily mean that eruptions have entered a new stage.
The agency said it has also confirmed that mudslides occurred at the foot of Mount Kompira, which is part of Mount Usu. The agency was not able to determine the scale of the slides, but said there have been no reports they have caused injuries or damage.
The Meteorological Agency issued mudslide warnings Wednesday for areas around Mount Usu as heavy rain was expected through today. It said the mudslides around the volcano could mix with volcanic ash and rocks loosened by seismic tremors.
The agency said the rain was expected to peak early today and forecast strong winds for the area.
Hiromu Okada, who heads a team of volcano experts monitoring Mount Usu, said the Earth’s crust near the mountain was expanding and contracting at an accelerated pace. Some of the numerous faults that have recently formed on the mountain now have sides as much as 10 meters out of alignment, he said.
Meanwhile, the Hokkaido Prefectural Government said evacuation orders affecting 13,000 residents of Date and the towns of Sobetsu and Abuta are still in force. The three municipalities form a triangle surrounding the mountain.
About 4,500 residents have spent recent days in evacuation shelters.
The number of tremors has subsided since peaking at 2,454 on March 30. In the first 10 hours of Wednesday, the Meteorological Agency recorded five earthquakes, compared to nine during the whole of Tuesday. The agency, however, did not rule out the possibility that an eruption could take place at the top of the mountain.
In the meantime, the problem of cattle, horses and pigs left behind in areas near Mount Usu by fleeing livestock farmers is becoming a concern. At present, the animals are being fed twice a day, in the morning and the evening, by farmers accompanied by police patrol cars. The farmers are concerned about whether the central and local governments are prepared to help care for the animals in case the farmers’ evacuation is prolonged by the unpredictable volcano.
Some of the livestock have been left in the care of those in safer areas.
According to the Date Municipal Government, 550 cattle, including 300 milking cows, 2,000 pigs, 30 horses and 120,000 chickens have been left in areas from which residents have been evacuated.
In addition, about 150 more milking cows have been transported to safer locations, the local government said.
Officials of the Hokkaido Prefectural Government’s Agricultural Bureau said they are considering giving appropriate technical guidance to farmers so they can care for their livestock in accordance with changes in the situation.