The Globe and Mail's team took your questions and put together need-to-know information on the disaster:
What was the magnitude of the quake?
The magnitude of the initial quake was 8.9 and it struck just off the coast of Japan's main island of Honshu. It's the biggest earthquake to hit Japan in more than a century, and one of the five biggest in the world since 1900.
How can I get information about family or friends living in Japan?
From reader Alex Svetlovsky: Google has activated their People Finder page in response to the situation in Japan: http://japan.person-finder.appspot.com/?lang=en
From reader Fred: My sales manager has a brother who works in Japan, he was unreachable by phone, which had us worried, but he eventually made it to a computer and posted on his facebook status that he was OK. If your family abroad has access to facebook, see if they've posted something there, or on twitter and other social networks. If not, post your concern on their wall and see if they respond. I did that when the earthquake in Chile happened and I needed to hear from my cousin that he was OK.
Here's what Foreign Affairs advises: Canadians who believe that they have Canadian friends or family who may be affected to call the Department of Foreign Affairs and International Trade at 613-943-1055, or toll free within Canada at 1-800-387-3124, or email firstname.lastname@example.org.
Canadian citizens in Japan requiring emergency consular assistance should contact the Canadian Embassy in Tokyo at (011-81-3) 5412-6200, or call DFAIT's Emergency Operations Centre collect at 613-996-8885. An email can also be sent to email@example.com. The Operations Centre of Foreign Affairs and International Trade Canada operates 24 hours a day, seven days a week.
What was communication like after the quake?
From Globe correspondent Mark MacKinnon (6:50 a.m. ET - March 11): I'm communicating with people in Japan via e-mail and Twitter right now, but phone lines are largely down.
From reader Alison Teasdale in Japan (10:40 local time, 8:40 a.m. ET - March 11): Cell phones and telephones in the areas are mostly not working, so people are having trouble contacting their families. My cell phone is working fine. The power is out in many parts of Tokyo and northern Japan, so cell phone batteries are also probably wearing out. I can see people lined up at public telephone booths to place calls in Tokyo on the news. The land lines seem to be working in some cases.
From reader Jeff Richmond in Japan (10:42 p.m. local time, 8:42 a.m. ET - March 11): Mobile phones were not working across the board for at least 3 hours after the quake. Land lines were swamped too. Calls on both are getting through now and then but it's sporadic. Even email (via cell phone) wasn't working.
How big were the tsunami waves that hit Japan?
From Globe correspondent Mark MacKinnon (6:50 a.m. ET - March 11): The wall of water that struck northeastern Japan this afternoon (local time) was reportedly 10 metres above sea level.
What parts of Japan were affected by the tsunami?
From reader Alison Teasdale in Japan (10:28 local time, 8:28 a.m. ET - March 11): For people unfamiliar with Japan, inland areas of Western Japan (Nagoya, Osaka, Kobe, Hiroshima, Nagashima) have suffered no damage from the earthquake, although there is still a possibility of a Tsunami along the coastlines in those areas. New tsunami warnings in effect for coastal Japan. In areas of Miyagi, Iwate and Fukushima prefectures they are predicting 10 metre waves.
@misterwordplay via Twitter: Watching Japanese TV now. Looks apocalyptic in Kanto area. Shocking. Kobe was spared. We had nothing here.
Where was the epicentre of the quake?
Here are the details of the earthquake, from the U.S. Geological survey:
Earthquake struck Friday, March 11, 2011 at 02:46:23 PM local time at epicenter
130 km (80 miles) E of Sendai, Honshu, Japan
178 km (110 miles) E of Yamagata, Honshu, Japan
178 km (110 miles) ENE of Fukushima, Honshu, Japan
373 km (231 miles) NE of TOKYO, Japan
What areas were under a tsunami warning?
From Globe correspondent Mark MacKinnon (6:53 a.m. ET - March 11): Tsunami warnings have been issued for pretty much the entire Pacific Rim. The tsunami warnings are all across the Pacific. Sirens are said to be sounding now in Hawaii. Taiwan looks to have been spared, but Indonesia - where memories of the 2004 Indian Ocean tsunami are still raw - looks to be in its path. Canada is obviously a long way off, but those on the Pacific coast should definitely be aware and start thinking about whether they want to move inland, just in case.
When did the tsunami hit those areas?
The Alaska/British Columbia border 0538 PST
Langara Island, British Columbia 0543 PST
The north tip of Vancouver Island 0626 PST
Tofino, British Columbia 0706 PST
Prince Rupert, British Columbia 0711
The Washington-British Columbia border 0712 PST
Bella Bella, British Columbia 0812 PST
Were any countries besides Japan seriously affected by the tsunami?
Indonesia: @journodave via Twitter: AFP reports Tsunami has hit Eastern Indonesia without causing any damage.
Washington state, Friday morning: Sheriff's deputies and firefighters in Washington's Grays Harbor County handed out tsunami warning fliers and urged residents to evacuate. The flier warns "This is not a drill," adding that an initial tsunami wave of around 3 feet is forecast for the area Friday morning after a massive earthquake in Japan. And the flier adds, "Following waves are expected to be larger." In Pacific County, the sheriff says an orderly evacuation is happening in Long Beach, Ilwaco and Ocean Park.
Hawaii: The Pacific Tsunami Warning Center said Kauai was the first of the Hawaiian islands hit by the tsunami. Water rushed ashore in Honolulu, swamping the beach in Waikiki and surging over the break wall in the world-famous resort but stopping short of the area's high-rise hotels.
Waves about 6 feet high were recorded on Maui, and 3 feet in Oahu and Kauai. Officials warned that the waves would continue and could become larger, but a scientist at the tsunami warning center said it didn't appear that they would cause major damage in Hawaii.
From a reader: From a Facebook friend at 3:17 a.m. PT: "In Kauai right now. South shore. Being evacuated right now. Police are directing people to higher ground. No panic as of yet, just a steady stream of people leaving the low lying areas. Warm night, no rain, lucky for people who have to stay out in the open for the next few hours. Gotta go though, being ushered to move faster."
California: The Coast Guard launched a search on Friday for a man swept out to sea in Northern California while taking pictures of tsunami waves.
Singapore: Tsunami warnings have been lifted for some densely populated Asia Pacific countries previously thought to be at risk after a huge earthquake that hit Japan on Friday, the U.S. Pacific Tsunami Warning Center (PTWC) and national officials said Friday morning.
Australia and New Zealand: Had been on an initial warning list, were later removed. The Joint Australian Tsunami Warning Centre confirmed there was no tsunami threat.
China, the Philippines, Taiwan, U.S. territory of Guam: Lifted their tsunami warnings in hours after quake, said the threat of the massive waves had passed.
Mexico: Detected the first ocean swells related to the tsunami about midday Friday. The swells are much weaker than predicted: A navy spokesperson says they've detected swells of about 70 cm, whereas earlier warnings predicted 2-metre waves.
Heavy swells have been rolling through the port and marinas of the Mexico's Baja California resort of Cabo San Lucas. Some are several feet (more than a meter) high, but no damage has been reported. Mexico earlier closed the cargo port of Manzanillo and officials say some ships have delayed entering ports to avoid possible problems.
Alaska: Alaska Emergency Management says the tsunami from the Japanese earthquake caused a wave just over 5 feet at Shemya and about 18 inches at Adak and Dutch Harbor in the Aleutian Islands.
The Alaska Tsunami Warning Center issued a tsunami warning for the coastal areas of Alaska from Attu to Amchitka Pass in the Aleutians and an advisory from Amchitka Pass along the West Coast to Oregon.
Where can I watch video of the earthquake?
From Globe correspondent Mark MacKinnon: Horrifying video from city of Sendai, city closest to epicentre of quake, broadcast by Japan's NHK: http://www.youtube.com/user/NHKonline
From Globe online editor Chris Hannay: YouTube has been collecting witnesses' videos from Japan on their Citizentube page: http://www.youtube.com/user/citizentube#g/c/0870831CE43351E1
What is Canada doing for Japan?
At an event in Guelph, Ont. on Friday morning, Prime Minister Stephen Harper is extending Canada's condolences and a helping hand to the people of quake-stricken Japan.
Harper says the country's thoughts and prayers are with those in Japan, which was rocked early Friday by a powerful earthquake that triggered a devastating tsunami.
He says he has offered any support and assistance that may be necessary, and says embassy officials are working to determine whether any Canadians have been injured.
What is the United States doing to help?
U.S. President Barack Obama said this morning that the U.S. "stands ready to help" in any way it can.
Obama said he has told the Federal Emergency Management Agency to be ready to assist Hawaii and any other U.S. states and territories that might be affected. He said he's ready to support the Japanese people "in this time of great trial."
"The friendship and alliance between our two nations is unshakeable," he said, "and only strengthens our resolve to stand with the people of Japan as they overcome this tragedy.
"We currently have an aircraft carrier in Japan and another is on its way. We also have a ship en route to the Marianas Islands to assist as needed. The Defense Department is working to account for all our military personnel in Japan. U.S. embassy personnel in Tokyo have moved to an off-site location, and the State Department is working to account for and assist any and all American citizens who are in the country."
How was air travel to and from Japan affected in the aftermath?
After the quake, more than 700 domestic flights in Japan were cancelled. Late Friday, Tokyo's Narita airport has partially resumed flights. Air Canada cancelled flights to Tokyo for Friday. Air Canada said it has no reports of injuries to any of its staff in Japan.
United Airlines said it expected conditions at Japanese airports to lead to delays or cancellations of flights to and from Japan. It asked customers to check their flight status before leaving for the airport and was offering to reschedule at no cost.
American Airlines and Delta say they will waive reissue fees for passengers booked to travel to Tokyo between Friday and March 18.
How did people in Tokyo who were stranded or homeless cope in the immediate aftermath?
As night fell and temperatures hovered just above freezing, tens of thousands of people remained stranded in Tokyo, where the rail network was still down. The streets were jammed with cars, buses and trucks trying to get out of the city.
The city set up 33 shelters in city hall, on university campuses and in government offices, but many planned to spend the night at 24-hour cafes, hotels and offices.
From reader Alison Teasdale in Japan (10:24 p.m. local time, 8:24 a.m. ET - March 11): All high schools in Tokyo are opening up as evacuation centres for those who can not get home tonight. A news report from Fukushima prefecture. Food and blankets are being distributed. Cell phone service is also improving. In many areas it was snowing today, so even in the evacuation centres it is going to be a cold night.
From reader Peggy Goodfellow (10:23 a.m. ET): email from daughter who lives in Japan. She and her students spend last night sleeping in the school gym. All trains are down and emergency services there are telling people to stay where they are. Don't use the roads until the all clear is given. Power is on. They are OK. She is south of Tokyo about 2 hours.
How many quakes hit Japan on March 11?
More than 80 aftershocks greater than magnitude-5 have been felt since the Japanese quake -- a number that scientists say is normal for a quake this size.
A strong 6.7-magnitude earthquake felt in Tokyo hit Japan's mountainous Niigata prefecture and caused landslides and avalanches at 4:00 am local time Saturday. (2 p.m. ET Friday)
Kyodo News Agency said there were no immediate reports of casualties and no fresh tsunami alert was issued after the quake, which was followed by an almost equally strong quake in the same area half an hour later.
The focus of both predawn quakes was in central Niigata.
The US Geological Survey put the strength at 6.2 and said it hit at a depth of only one kilometre.
Police said they had received reports of a landslide and avalanche in Tokamachi and another avalanche in Tsunan town, Kyodo reported. There were no other immediate reports of major damage.
From reader Alison Teasdale in Japan (11:40 p.m. local time, 9:40 a.m. ET - March 11): Just to put things in perspective, there have been over 60 aftershocks of various degrees in intensity in the last 8 hours. Most have been centred in Miyagi, Fukushima, Ibaraki Prefectures.
How did the disaster affect financial markets?
U.S. stocks fell at the open on March 11 and accelerating inflation in China unnerved investors.
The Dow Jones industrial average fell 33.08 points, or 0.28 percent, to 11,951.53. The Standard & Poor's 500 Index dipped 2.42 points, or 0.19 percent, to 1,292.69. The Nasdaq Composite Index lost 6.51 points, or 0.24 percent, to 2,694.51.
Oil prices slid more than $3 a barrel, with U.S. crude falling below $100, while MSCI's all-country world index of global stocks fell to a five-week low after the Japan earthquake.
Who should I follow on Twitter to get more information?
How can I donate money to the Japan relief effort?
Foreign Affairs has information on their website about on how Canadians can help: http://www.international.gc.ca/humanitarian-humanitaire/japan_earthquake_japon_seisme.aspx?lang=eng
From reader Alex Svetlovsky: The Canadian Red Cross has put out a call for donations: http://twitter.com/redcrosscanada/status/46278602437828608
Which parts of Canada are most at risk for an earthquake?
A list from The Canadian Press on areas in Canada with the greatest chance of having an earthquake:
- West coast of Vancouver Island.
- Off the northeast coast of Melville Island in the Arctic.
- Central eastern Yukon near the N.W.T. border.
- South shore of the lower St. Lawrence River in Quebec.
- Off the southeast coast of Newfoundland in the Atlantic Ocean.
(Source: Geological Survey of Canada, 2005)
What was it like in Japan after the quake and tsunami struck?
@hiroko_nakamura via Twitter: People walking and driving home. Walking faster than driving.
@burninlover via Twitter: People are tweeting from Tokyo Disneyland saying DisneySea is flooding and the parking lots is over flowing with water.
From reader Shabbar in Japan (10:11 p.m. local time, 8:11 a.m. ET March 11): We're still experiencing powerful aftershocks in Tokyo, almost every hour (about 5.0 - 6.0 in magnitude). I'm stuck at my lab at Tokyo University as public transportation has been suspended this evening. I was actually on the Marunochi line (between Shinjuku and Yotsuya in Central Tokyo) when the first earthquake hit. We were evacuated to the street just before the major earthquake struck. People ran into the street and buildings began swaying.
From reader Jeff Richmond in Japan (10:26 p.m. local time, 8:26 a.m. ET - March 11): I'm here in Tokyo, have lived here 11 years and experienced plenty of quakes, big and small, including the Niigata temblor several years ago that rattled Tokyo second only to this one earlier today. In comparison to which the Niigata shaker was NO-THING.
This was by far the worst earthquake here I've ever felt--and that's no exaggeration--in the 11 years I've lived and worked here. I was up on the 30th floor of the news agency building in which I work smack-dab in the center of downtown Tokyo (adjacent to the Imperial Palace) and at first it was a slow "as usual" back-and-forth event, with only a little of the (worse, more dangerous) up-and-down rumbling. Within 30 seconds, however, it became very clear this was no "ordinary" quake--not even an "ordinary" big quake.
We shook and swayed violently. People were screaming. Books, papers, files were flying off shelves. (I've seen some of this on TV here, so you may be seeing similar footage there within hours if you haven't already). We have huge file "closets" on tracks up here that are two deep and can be rolled aside, and these were careening back and forth and banging against each other...this among a lot of other terrifying "background" noise that usually accompanies these shakers.
Employees all over Chiyoda Ward downtown are stranded. Convenience store shelves are all but empty downtown here. Never seen anything like it in 11 years here.
From reader Alison Teasdale in Japan (10:36 local time, 8:36 a.m. ET - March 11): I am several hundred kilometers from the effected areas, so I am not personally experiencing any trouble, but all the news channels are reporting from the disaster areas. I was at work in a Toyota car factory when the earthquake hit. The shaking was horrizontal and shook for a very long time. Now that it has gotten dark out, instead of the disaster areas, the news reports are focusing on how people are spending the night in the evacuation centers and getting home, particularly in the Tokyo area From reader Scott McLean in Japan (11:24 p.m. local time, 9:24 a.m. ET - March 11): Made it home after walking for 5 hours. Main streets are completely here in Tokyo totally jammed, dangerous situation as emergency vehicles can't get though the traffic. One main street, Yasukuni Dori, cars going about half the speed as walkers, saw old people getting off a bus between stops so they could walk. Stranded people who live too far out to walk are everywhere, cold and windy night too.
Click on the box below to get a recap of The Globe and Mail's live updates as events unfolded today. If you're seeing this on a smartphone, use this link.