Information for foreigners
Japan's Meteorological Agency says aftershocks could continue for a week. It advises people in the affected areas to stay indoors. It's also warning people to watch out for broken glass and to stay away from downed power lines to avoid being electrocuted.
NHK World Japan advises those in the affected areas to check with their local municipalities for updates and advisories. Those in Hokkaido who need information in English, Mandarin, or Korean can call the Hokkaido Disaster Prevention Information at one of the following
The English service is available 24 hours, while Mandarin and Korean services are available between 8:45AM and 5:30PM on weekdays. The services are for foreigners in Hokkaido only.
Information can also be found on the Hokkaido disaster prevention website
The website can also be found by doing an Internet search for "Hokkaido disaster prevention information."
Landslides engulf homes
The Meteorological Agency estimates the magnitude of the earthquake was 6.7. A tremor of 7 was recorded in the town of Atsuma, which is the highest on Japan's seismic intensity scale. The huge tremor triggered landslides, wiping out homes there. Many of the missing are from this town of 33 residents. Helicopter crews are carrying out rescue operations.
The extent of the damage is still being assessed. But throughout the prefecture, buildings are tilted and roads are cracked and buckled.
A man in Sapporo described the frightening moment. "The whole building shook for about 30 seconds. It felt long," he says.
Another man says, "It was shaking up and down. The tremors came suddenly with a big thud."
Prime Minister Shinzo Abe says his government has set up an emergency task force that is putting a priority on search and rescue, and 25-thousand Self-Defense troops will be sent.
Electricity shut down across the prefecture
Nearly 3 million households throughout Hokkaido are without power. The industry ministry says the tremor shut down the largest thermal power plant in Hokkaido, the Tomato-Atsuma plant, which in turn led to a shutdown of all other thermal and hydro plants in the prefecture.
Hokkaido Electric Power Company has resumed operation of 4 hydropower plants. But the electricity generated is being used to restore the thermal power plants, and it is still unable to supply power to homes and businesses.
The utility is also conducting inspections to search for damage to power cables and substations across the prefecture.
The ministry says it will take at least a week for a full recovery. It has ordered operators to get the power plants running as soon as possible.
Tomari nuclear power plant using emergency generators
Despite the power outage, authorities say a nuclear power plant in the region has not experienced any safety issues. The Tomari nuclear power plant's 3 reactors have been offline since 2012 following the Fukushima nuclear accident.
When the power went out during Thursday's quake, 6 emergency diesel-powered generators automatically switched on to keep cooling more than 1,500 fuel rods in storage pools.
Japan's nuclear authorities and the plant operator say the generators can keep the Tomari plant running for at least a week.
People gather at evacuation shelters
Evacuation shelters are being set up in many towns and cities. People are gathering at them in preparation for possible aftershocks.
A 79-year-old woman at one of the shelters told NHK about her moment of desperation following the huge tremors. "I was sleeping when the tremors hit. I immediately got up. When I tried to open the door, it started shaking violently. I clung to it and managed to exit the house."
A man in his 20s at a shelter said, "Things are scattered everywhere in my house. I came here to escape to a place with more space where food is available."