Houses and ships are swept away after what experts believe is world's fifth biggest quake since 1900. Read the latest developments here:

3:10 p.m. ET Several organizations are jumping in to help victims of the Japanese quake. Click here to see a list of organizations and how you can help.

3:00 p.m. ET Economist.com has an interesting graphic that lists the world’s largest recorded earthquakes – Friday’s ranks fifth.  

2:50 p.m. ET The massive earthquake that struck off the coast of Japan Friday was the strongest quake in the area in nearly 1,200 year,  David Applegate, a senior science adviser for earthquake and geologic hazards for the U.S. Geological Survey, told the AP. He said the 8.9-magnitude quake ruptured a patch of the earth's crust 150 miles long and 50 miles across.

2:45 p.m. ET Air that may contain radioactive materials will be vented from a nuclear power plant in quake-stricken Fukushima Prefecture, NHK World reported. The Tokyo Electric Power Company has decided to release air from the reactor's containment vessels,  in an effort to avoid their breakdown.

1:09 p.m. ET Dr. Ellen Prager, a marine scientist and author, explained this interesting graphic from NOAA regarding the recent tsunami.

"This NOAA graphic shows the predicted wave height throughout the Pacific Ocean, from a computer model,” said Pager. “One of the things it shows, that we learned following the Indian Ocean Tsunami, is that the energy is not directly evenly in all directions, and luckily the U.S. West Coast is not in the direction of the greatest energy flow.”

1:05 p.m. ET: Japan says pressure is rising at nuclear reactor after cooling system failure, the AP reports. NTV reports that the nuclear reactor pressure issue was caused by a power shortage (as reported elsewhere) and that electricians are working to get power back within an hour.

12:45 p.m. ET: U.K.’s Metro newspaper puts the Japan quake in context by comparing it to the earthquake that recently struck Christchurch, New Zealand.

“To put that into some sort of context, it's 8,000 times larger than the one that destroyed Christchurch last month, and on a similar scale to the Chile earthquake in February last year,” Brian Baptie, a seismologist from the British Geological Survey in Edinburgh told the Metro.

12:30 p.m. ET: More dramatic video of the Japan earthquake and tsunami from ITN:

12:15 p.m. ET: The United States has transported coolant to a Japanese nuclear plant hit by the massive Friday earthquake, Secretary of State Hillary Clinton said.

"We just had our Air Force assets in Japan transport some really important coolant to one of the nuclear plants," Clinton said at a meeting of the President's Export Council.

"Japan is very reliant on nuclear power and they have very high engineering standards but one of their plants came under a lot of stress with the earthquake and didn't have enough coolant," Clinton said.

12:00p.m. ET: Wrap-up of video of the devastation from NBC's Anne Thompson:

11:57 a.m. ET: Kyodo News reports the death toll from the Japan quake is likely to surpass 1,000.

11:07 a.m. ET: Statement by Japan’s Prime Minister Naoto Kan on earthquake

My fellow citizens, as you are already aware from reports on TV and on the radio, today at 2:46 PM an enormously powerful earthquake of Magnitude 8.4 struck, with its seismic center off the Sanriku coast. This has resulted in tremendous damage across a wide area, centered on the Tohoku district. I extend my heartfelt sympathy to those who have suffered.

As for our nuclear power facilities, a portion of them stopped their operations automatically. At present we have no reports of any radioactive materials or otherwise affecting the surrounding areas.

In light of these circumstances, I immediately established an emergency headquarters for response to disaster, with myself as the head. The government will make every possible effort to ensure the safety of the public and keep damage to the minimum possible extent.

I ask the public to continue to stay fully vigilant and to keep abreast of TV and radio reports, and I ask everyone to act calmly.

10:45 a.m. ET: Two more aftershocks measuring 5.1 hits near the east coast of Honshu, Japan, the U.S. Geological Survey reports.

10:25 a.m. ET: Disaster bulletin boards have been set up by Japanese phone carriers, NHK World reports. The Chinese and South Korean embassies, as well as representatives of Taiwan, have also established telephone helplines specifically for their nationals, NHK reports.

10:05 a.m. ET: Oil prices have dropped below $100 per barrel for the first time in more than a week after the massive earthquake spawned a tsunami that slammed into northern Japan. Japan is the third-largest oil importer in the world. But 18 percent of Japan's refining capacity has shut down as a result of the tsunami, impacting the worldwide demand for oil.

9:30 a.m. ET: Runways at both Haneda and Narita airports have been opened, NHK World reports. However there are significant flight disruptions.

9:15 a.m. ET: Japan coast guard searching for ship with 80 on board washed away by tsunami, AP reports.

JAPAN OUT AFP PHOTO / HO / NHK

A screen grab taken from news footage by Japanese Government broadcaster NHK on Friday shows cars on a flooded street following an earthquake-triggered tsumani in Miyagi prefecture. Click on the photo above for a slideshow of the devastation across Japan.

8:52 a.m. ET: Japanese police say 200 to 300 bodies have been found in a northeastern coastal area as a result of the tsunami, AP reports. The death toll is expected to climb given the magnitude of the disaster.

8:48 a.m. ET: The Japanese government has declared an emergency situation at one of Tokyo Electric Power company's nuclear power plants in quake-stricken Fukushima Prefecture, NHK reports. It says no radioactive materials have been leaked. But Tokyo Electric said an equipment failure has made it impossible to cool two reactors at the Fukushima Number One plant. The firm says it does not have enough electric power to cool the reactors, which automatically stopped operating when the quake struck.

8:35 a.m. ET: A tsunami alert for Guam has been lifted after it was triggered by a massive earthquake off Japan, Reuters reported the U.S. Pacific territory's governor said in a statement.

7:55 a.m. ET: Disrupted train services and traffic jams strand massive crowds in capital Tokyo, according to NHK.

7:52 a.m. ET:  Around 1,300 are stranded in Sendai airport after water swamped the gates and surrounded the terminal buildings, NHK reports. Here's video of the damage on Flightglobal.

7:38 a.m. ET:  The news of damage throughout Japan is coming in fast. More than 300 houses destroyed in a single city, Sky News reports citing Jiji News.  NHK is reporting that a home for senior citizens collapsed, killing several residents.  There are also reports of 600 people huddled together in a elementary school that is serving as a shelter.  The building is without power so people are using their cell phones for light. 

7:32 a.m. ET:  The death toll from the earthquake rises to 59, according to Kyodo.

7:28 a.m. ET:  The International Atomic Energy Agency says it is looking for more information on the condition of Fukushima nuclear reactor buildings and cooling systems, Reuters reports. Meanwhile, Japanese authorities say that fire at Onagawa nuclear plant has been extinguished.

7:22 a.m. ET:  Kyodo is reporting that 2,000 residents near Fukushima nuclear power plant have been urged to evacuate. This is the plant that that developed a mechanical failure in the reactor cooling system after it was shut down in the earthquake. 

7:16 a.m. ET:  A huge number of people are stranded in Tokyo after all railway services in the capital's metropolitan area are suspended, Kyodo News reports.  The East Japan Railway Co. suspended its services for all railways in the metropolitan area as well as bullet train services on the Tohoku, Joetsu, Nagano, Yamagata and Akita Shinkansen Lines. 

7:13 a.m. ET:  The American military is preparing for rescue operations and is ready to help if the Japanese government asks for assistance, according to NHK. Russia has also said it is ready to send aid.

7:08 a.m. ET:  A NHT correspondent just warned that tsunamis arrive in sets and often the strongest waves don't come first.

7:03 a.m. ET:  Read the American Red Cross guide on how to prepare for tsunamis.

7:00 a.m. ET:  Japanese police raise the death toll from the earthquake and tsunami to 40, the AP reports. Thirty-nine are still missing.

6:56 a.m. ET:  Google has activated a Person Finder page to help people concerned about loved ones in the area affected.

6:50 a.m. ET:  The earthquake won't affect the Chinese mainland "obviously," although tremors were felt in parts of Beijing,  seismological official Chen Jianmin tells Xinhua. "But most parts of the Pacific region should keep vigilant against a tsunami triggered by the quake," he says.

6:45 a.m. ET: NHK reports another strong aftershock, says people in crowded temporary shelter screamed when it hit.

6:39 a.m. ET:  Watch a video report on the situation at Fukushima nuclear power plants.

6:31 a.m. ET:  This just in from Reuters: A ship carrying 100 people was swept away by the tsunami that smashed into northeastern Japan, Kyodo news agency reports.

6:31 a.m. ET:  Officials fear tsunami may have washed over entire islands in the Pacific, CNN reports.

6:29 a.m. ET:  Chief Cabinet Secretary Yukio Edano says the nuclear power plant in Fukushima developed a mechanical failure in the system needed to cool the reactor after it was shut down in the earthquake.  He said the measure was a precaution.

6:23 a.m. ET: President Obama offers condolences to the people of Japan and says: "The United States stands ready to help the Japanese people in this time of great trial. The friendship and alliance between our two nations is unshakeable, and only strengthens our resolve to stand with the people of Japan as they overcome this tragedy. We will continue to closely monitor tsunamis around Japan and the Pacific going forward and we are asking all our citizens in the affected region to listen to their state and local officials as I have instructed FEMA to be ready to assist Hawaii and the rest of the US states and territories that could be affected."

6:15 a.m. ET:  The National Oceanic and Atmospheric Administration's Tsunami Warning Center issues a list of estimated tsunami arrival times for locations along the North American Pacific coast.

6:07 a.m. ET:  Government has no information on radioactive leakage, government minister says, according to NHK World.

5:44 a.m. ET:  Nuclear power plant administrator in northern Japan says process for cooling reactor is "not going as planned," adding that "nuclear emergency situation" has been declared.  Asks people nearby to stay calm, NHK World reports.  Also says that American military has offered to help.

5:24 a.m. ET:   The West Coast and Alaska Tsunami Warning Center just put out this tsunami propagation forecast.

5:16 a.m. ET:  Japan's Fire and Disaster Management Agency and police say at least 29 people died in the quake that unleashed the 13-foot tsunami that swept boats, cars, buildings and tons of debris miles inland, according to the AP.

5:11 a.m. ET:  All U.S. service members are accounted for and there are no reports of damage to U.S. installations in Japan, a Pentagon spokesman tells NBC News.

5:10 a.m. ET:  Flights to Tokyo are now being diverted to Anchorage, Alaska, according to Airport Operations. Two flights are on the ground now, one more is coming, according to NBC affiliate KTUU.

5:06 a.m. ET:  A Japanese utility reports a fire at turbine building at a nuclear power plant in northeastern Japan, the AP reports.

5 a.m. ET:  A tsunami warning has been issued for the entire Pacific basin except for the mainland United States and Canada following the huge earthquake that hit Japan on Friday, according to the Pacific Tsunami Warning Center.

- F. Brinley Bruton, msnbc.com