The precise number of casualties in Hokkaido remains unclear.
The latest tally by public broadcaster NHK as of 9am showed that at least 20 people are missing – and could have been buried alive in their homes due to the mudslides. At least 120 people were injured, including 87 in capital city Sapporo alone.
Japan’s northernmost island is also the country’s largest prefecture and home to about 5.4 million people.
According to the Japan Meteorological Agency, the magnitude-6.7 earthquake recorded upper 6 on the Japanese seismic intensity scale of 7 in the town of Abira, Hokkaido, and lower 6 in the city of Chitose, Hokkaido. The quake, which struck at about 3:08 a.m., was centered at a depth of about 40 kilometers in the eastern part of the Iburi district.
An official in the Abira city office said the earthquake knocked items off bookshelves and desks.
“We won’t know the full extent of the damage until after sunrise,” the official said.
Guests at a hotel near JR Sapporo Station were seen standing outside the hotel with worried expressions after the quake.
Power was cut in cities including Sapporo, Hakodate and Tomakomai.
The New Chitose Airport, which serves Sapporo, will be closed for the whole of Thursday at least, due to the power outage and extensive structural damage with burst water pipes and collapsed wall panels.
Shinkansen bullet train services connecting Aomori, the northernmost prefecture on Japan’s main island, to Hakodate, the southernmost city on Hokkaido, have also been temporarily halted.
Dramatic news pictures show a landslide along a long ridge in the rural town of Atsuma, as well as collapsed brick walls and broken glass and overturned furniture in homes.
Efforts to restore power are currently underway. Trade and Industry Minister Hiroshige Seko said the ministry has instructed Hokkaido Electric Power to restart the coal-fired Tomato-Atsuma power plant “within a few hours”.
Prime Minister Shinzo Abe, in convening an Emergency Response Headquarters meeting, said 25,000 Self-Defence Force (SDF) personnel will be activated for relief operations.
The JMA has warned of the possibility of aftershocks of a similar intensity for the next week.
Japan is situated on the “Ring of Fire” arc of volcanoes and oceanic trenches that partly encircles the Pacific Basin, and accounts for about 20 per cent of the world’s earthquakes measuring at least magnitude 6.0.
Thursday’s tremor registered a six-plus on the seven-point Japanese ‘shindo’ seismic intensity scale, which measures earthquakes by their impact on the public and not by geology.
A reading of six-plus means that most will find it impossible to remain standing and to move without crawling.
The earthquake comes as Japan grapples with the disaster relief in the aftermath of the strongest typhoon to hit the country since 1993.
Typhoon Jebi, which made landfall on Tuesday (Sept 4) in the Kansai region, had left at least 11 dead and 600 injured, flooding the Kansai Airport and forcing the closure of the facility.
Mr Abe said on Thursday that domestic flights will resume on Friday, with international flights to follow “as soon as possible”.