SAPPORO – Mount Usu, which had been dormant for about 22 years, erupted for a fourth time Saturday afternoon, keeping residents uncertain of when they’ll be able to return home.
While there have been no casualties reported so far, experts said it was hard to determine when the activity would subside — a factor that could sway the lives of the thousands of local residents who have taken refuge in shelters.
Hokkaido University professor Hiromu Okada, who inspected the 732-meter volcano from a helicopter, said that by the end of the day, he had confirmed the existence of roughly 10 openings in two areas on the mountain’s sides.
Tadahide Ui, a professor at Hokkaido University, said substances from the eruptions showed that they were magma phreatic explosions that occur when magma comes into contact with underground water. He noted that the magma at Usu was rising to a level very near the surface, but added that he saw no indication that activity was increasing.
The first of the eruptions occurred Friday afternoon.
The Meteorological Agency said early Saturday that it detected thick smoke rising from the western foot of the mountain at around 2:50 a.m. with a highly sensitive camera.
The sky lit up for about 10 minutes from around 3:20 a.m., agency officials said. The observatory said the gray smoke rose to about 200 meters as of 7 a.m., but could not confirm any pyroclastic flows.
Another eruption occurred around 11:40 a.m. Saturday on the northwest side of the mountain near the Lake Toya hot spring resort.
The Mount Usu area was rocked by another eruption at around 1 p.m., which occurred near the site of the first.
The Meteorological Agency’s Muroran Meteorological Observatory, southeast of Mount Usu, issued another volcanic warning after the eruption near Lake Toya.
The observatory also issued a volcanic advisory Saturday, warning of mudflows as the mountain is covered with snow, and rain and snow have been seen in the area since Friday evening.
The roofs of hotels and houses were covered with volcanic ashes and damage to property were reported in some part of the area.
In addition, a portion of track on the JR Muroran line was found by aerial survey to be damaged.
About 5,000 local residents stayed overnight at some 30 shelters set up in local elementary and junior high schools in Date and the towns of Sobetsu and Toyoura.
Some elderly people are suffering from exhaustion and illness after spending four days at the shelters.
On Saturday, baths were provided at some of the shelters, and many taking refuge from the eruptions were able to sink into a warm tub of water for the first time in days.
The Hokkaido Prefectural Government dispatched officials to the municipalities to discuss the need or possibility of setting up temporary housing in the event the evacuation continues for a prolonged period of time.
Most of the residents of the town of Abuta are in the shelters of neighboring municipalities, and the town decided to move roughly half of the nearly 3,000 townspeople sheltered in Toyoura to the village of Toya and other areas. The move is part of efforts to ease the burden on both Toyoura and the townspeople.
Masaaki Nakayama, head of the National Land Agency, and the team of central government researchers visited shelters in Date and other towns to inspect conditions.
The Ground Self-Defense Force increased the number of personnel distribution water and food to the afflicted to some 3,000, while the Hokkaido Prefectural Police dispatched about 1,000 officers with the help of other prefectural police forces to regulate traffic and stand vigil.
The Meteorological Agency said a quake with an estimated magnitude of 4.8 on the open-ended Richter scale, the largest so far in the recent series of volcano-related tremors, hit the town of Sobetsu, just north of Mount Usu, at around 3:12 a.m. Saturday.
The quake registered lower 5 on the Japanese intensity scale of 7, the agency said.
Missing man found
A 64-year-old man feared missing near Mount Usu, which sprang back to life with an eruption Friday, was safely found in an inn in the town of Toyoura, it was learned Saturday.
Torao Nakagawa, unemployed, from the town of Abuta, said he tried to drive back to his home near the volcano’s crater but failed because the road was blocked by rocks some 50 cm in diameter.
“I only have the clothes I am wearing now and slippers instead of shoes. I am worried about my house but it seems to have been punched full of holes due to showering rocks,” a dejected Nakagawa said.
Nakagawa’s house is about 1 km from the crater. He said he saw smoke rising from the crater Friday when he drove to a nearby hill.
When he tried to go home a few hours after, he could not go back as rocks blocked the road, Nakagawa said. He went to a nearby gas station to fill up just in case he would have to evacuate, but they were all closed.
He went to the neighboring town of Toyoura to refuel, but then could not return to his town due to traffic control measures, Nakagawa said.
Nakagawa’s wife was safe as she had been at her parents’ home in Sapporo since Tuesday. It had been believed that the couple failed to evacuate.