Japan has awoken to devastation along its northeastern coast, with fires raging in many cities, parts of others still underwater and serious concerns about two nuclear reactors in the worst hit area.
At least 1,000 people are known to have died in the massive 8.9 magnitude earthquake the tsunami that followed.
The US Geological Survey says the initial quake caused a rupture in the Earth’s crust 150 miles long and 50 miles wide – dozens of strong aftershocks were felt in the hours that followed.
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Updates 0900-2359
2359 The earthquake has sparked at least 80 fires in cities and towns along the coast of Japan.
Car manufacturing plants, electronics factories and refineries have been shut, many roads are buckled and power to millions of homes and businesses has been knocked out.
Several airports, including Tokyo's Narita, have been closed and much of the nation's rail services halted. All ports remain shut.
2359 A total of 45,000 people living within a 10km radius of the Fukushima facilities have been told to leave the area under an evacuation order.
2358 The two reactors at Fukushima - Fukushima No1 (Daiichi plant) and Fukushima No 2 (Daini plant) - are located around 240km north of Tokyo.
Tokyo Electric Power (TEPCO) has confirmed it has lost the ability to control the pressure in some of the reactors at both plants.
Gas is due to be vented at Fukushima No 1 shortly to ease the pressure there.
'The situation is still several stages away from Three Mile Island when the reactor container ceased to function as it should,' stressed Tomoko Murakami, leader of the nuclear energy group at Japan's Institute of Energy Economics.
Japan informed the International Atomic Energy Agency (IAEA) that the quake and tsunami had cut the supply of off-site power to the plant and the diesel generators intended to provide back-up electricity to the cooling system.
2357 Jiji news agency is reporting that a ship, thought to have been lost in the tsunami, has been found. All 81 people on board are being airlifted to safety.
2347 NHK now reporting that Tokyo Electric Power has warned the Japanese government that 'equipment failures are making it impossible' to cool three of the four nuclear reactors (reactors 1,2 & 4) at the second Fukushima nuclear plant (Fukushima No 2).
2341 Readings from an observatory in Miyagi prefecture show it is now located four metres further east than it was before the earthquake.
2331 The Japanese government has ordered Tokyo Electric Power to vent gases from the Fukushima No 1 plant to release the pressure and avoid damaging the facility.
2320 In the capital Tokyo, many residents have spent the night in offices and train stations after public transport was shut down.
80,000 people spent the night in temporary shelters.
Some subways in Tokyo are resuming operation this morning, but many trains still not running and many highways are closed.
2307 Aerial shot of the Fukushima plant
2301 Tokyo Electric Power says it has lost the ability to control pressure in some of the reactors of a second nuclear power plant at its quake-hit Fukushima facility.
'Pressure is stable inside the reactors but rising in the containment vessels,' a spokesman said.
He said he did not know if there would be a need to release pressure at the plant at this point - this would involve a release of radiation.
2235 Latest aerial video of damage taken a short time ago
2231 It has been reported that 'an emergency situation' has now been declared at Fukushima No 2 plant - in addition to the ongoing cooling problems at Fukushima No 1 plant.
NHK says that in both cases small amounts of radioactive material may be vented into the air to ease the pressure - 'it is hoped that this will not affect human beings in a serious manner,' says the Japanese Nuclear Safety agency.
2229 Japanese TV saying up to 13,000 people were stranded in Tokyo's Narita Airport overnight.
2219 NHK, quoting nuclear safety officials, says there is 'no immediate health hazard' to residents from the small radiation leak at Fukushima.
People are being urged to evacuate the area calmly.
The elevated radiation reading was taken in the control room of the No 1 reactor of the Fukushima plant.
2211 'Every indication is that the type of event that has occurred there (Fukushima) is one of the most serious things that can happen in a nuclear reactor.' Nuclear expert Edwin Lyman has told Reuters.
2147 AFP is reporting that radiation levels are now 1,000 times above normal at the Fukushima nuclear plant.
Meanwhile, the US military now says it did not provide any coolant for the reactor, as had previously been reported.
One US official told AFP a short time ago that Japan had asked the US for the coolant - but ultimately decided to handle the matter on its own.
The Japanese government has expanded its evacuation order to a 10km radius around the nuclear reactor.
2131 Chile's government says it is evacuating low-lying coastal areas and moving resident inland.
2115 As dawn breaks over Japan, further reports of damage are coming in.
Jiji news agency is reporting that the northeastern Japanese city of Kesennuma, with a population of 74,000, has been hit by widespread fires and one-third of the city is submerged.
2112 At least 384 people are confirmed dead so far. This toll is expected to rise significantly.
2054 Japan Railways now says that four trains are unaccounted for after the earthquake and tsunami.
2049 The separate 6.7 magnitude (revised upwards) earthquake in Niigata prefecture a few hours ago is understood to have caused landslides and avalanches in the region.
Kyodo News said there were no immediate reports of casualties after the quake, which was followed by an almost equally strong quake in the same area half an hour later.
The quakes struck in the west of the main Honshu island, on the Sea of Japan coast and far from the offshore Pacific Ocean tremor.
The US Geological Survey said the latest earthquakes 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.
2041 This National Oceanic and Atmospheric Administration image projects the wave heights of the tsunami across the Pacific basin.
2015 Pressure in the Fukushima nuclear plant has risen to 1.5 times the designed capacity, says the Japan Nuclear Safety agency.
Radioactive gas building up inside the plant is set to be released soon.
'It's possible that radioactive material in the reactor vessel could leak outside but the amount is expected to be small and the wind blowing towards the sea will be considered,' Chief Cabinet Yukio Edano told a news conference a short time ago.
2000 Pope Benedict XVI has said he was ‘deeply saddened’ by the events in Japan.
The country is predominantly Shintoist and Buddhist, with only 1.5% of the total population, or less than 2m people, Christians. Less than 500,000 are Catholic.
1953 Japan has requested a limited number of foreign search and rescue teams to help with the aftermath of its major earthquake and tsunami, according to the United Nations.
More than 68 search and rescue teams from 45 countries have offered aid to Japan, but it has only asked for a handful to travel.
1939 The US Geological Survey says this morning's earthquake caused a rupture in the Earth's crust 150 miles long and 50 miles across.
1938 The Tokyo Electric company says it has decided to release 'possibly radioactive' gas from containment vessels at the nuclear plant in Fukushima following a severe build up of pressure.
1927 NHK has confirmed that the latest earthquake had a magnitude of 6.6 - saying it struck the mountainous Niigata prefecture of Honshu island.
1906 NHK is reporting a 6.6 magnitude earthquake in the northwest of the country.
The station is saying the latest tremor is not directly related to this morning's earthquake - which occurred in the northeast. It is not an aftershock.
1853 The International Red Cross has set up a website to help thousands of people who have lost touch with relatives or friends in quake-hit Japan.
1845 Still no firm information on the pressure build up at the nuclear reactor in Fukushima.
A few minutes ago, a spokesman for Tokyo Electric Power said authorities were nearing a decision to release radioactive steam from the troubled reactor in a bid to ease the pressure.
'Pressure has risen in the container of the reactor and we are trying to deal with it,' said Banri Kaieda.
The Japanese government has ordered thousands of residents living within a 3km radius of the Fukushima No 1 plant to leave the area.
1838 Stranded commuters sit at Tokyo International Forum after all public transportation was suspended.
1817 A small radiation leak 'could occur 'at Fukushima nuclear plant, Japan's trade minister has admitted.
Officials say a pressure build-up has occurred in one of the reactors after the earthquake.
1758 The New Scientist is reporting that the Japanese earthquake may have been as strong as 9.0 magnitude
1751 A total of 11 reactors at four plants operated by three firms have been shut down after the earthquake in Japan.
Japan's nine utilities and one wholesaler have 54 nuclear power generators for commercial use.
1731 Despite the evacuation of an area around Fukushima nuclear plant there is as yet no word on whether there has actually been a leak.
Tokyo Electric Power Co said pressure inside a reactor at its Fukushima-Daiichi plant rose after the cooling system was knocked out by the earthquake.
Kyodo news agency quoted the company as saying that the radiation level was rising in the turbine building and the pressure had risen to 1.5 times the designed capacity.
Experts say there could be leakage if water levels in the Fukushima reactor fell and the temperature of the nuclear rods rose, though this might not happen immediately.
'Even if fuel rods are exposed, it does not mean they would start melting right away,' said Tomoko Murakami, leader of the nuclear energy group at Japan's Institute of Energy Economics.
1700 Californian search and rescue teams say they are on standby to help out in earthquake-hit Japan if needed - only a day after returning from searching the rubble in New Zealand.
The Los Angeles County Fire Department said it could send more than 70 experts in search and rescue, including paramedics, if called on by Japanese authorities.
1632 The US Geological Survey says today's earthquake in Japan ranks as the fifth largest in the world since 1900.
1617 Police are now putting the confirmed death toll in Japan at 337, That figure is expected to rise significantly.
1609 There are reports that a dam has broken in Japan's northeast Fukushima prefecture.
Many homes have been washed away, says Kyodo news agency.
1600 The situation at Japan's Fukushima nuclear plant is said to be under control, and water is being pumped into its cooling system, according to the IAEA.
1548 Video showing skyskrapers in Tokyo swaying during the earthquake
1545 The Philippines has lifted its tsunami warning.
1538 US President Barack Obama has called Japanese Prime Minister Naoto Kanto offer help.
President Obama earlier delayed a scheduled press conference by 75 minutes so that he could get a briefing on the disaster, a US National Security Council spokesman said.
1526 A nuclear plant in Fukushima prefecture, north of Tokyo, whose cooling system failure prompted a government evacuation order for thousands of nearby residents is expecting to have its system return to normal soon.
1519 Taoiseach Enda Kenny says the solidarity of the Irish people is with the people of Japan 'in this moment of great trial.'
'While it is our sincere and earnest belief that the Japanese people will recover quickly and fully from this disaster, Ireland stands ready to assist our Japanese friends in any way possible.'
1518 Fires raging in the city of Natori following the tsunami..
1517 The Japanese military is readying 300 planes and 40 vessels for an earthquake relief effort, according to the Kyodo news agency.
1515 Tsunami waves have washed ashore in Hawaii, but the popular tourist destination appears to have escaped major damage.
As sirens blared and Hawaiian authorities rapidly evacuated low-lying areas, the Pacific Tsunami Warning Center reported wave changes at Waianae Harbour at around 3:24am (1.24pm Irish time). Many residents had already taken refuge in shelters.
Hawaii and parts of the US West Coast were placed under a tsunami warning after a 8.9-magnitude quake hit Japan, the largest ever recorded in the Asian nation's history.
The quake triggered a huge tsunami that slammed parts of the Japanese coastline.
The largest wave to crash ashore in Hawaii - some 4,000 miles (6,500km) from the epicentre of the quake - was measured as a six-foot (1.8m) surge and hit Kahului on Maui.
1510 Millions of Japanese citizens learned about today’s massive earthquake about one minute before they could feel its violent shockwaves, thanks to an early-warning system.
The sophisticated system is connected to network of about 1,000 seismometers around the country which detect and analyse primary waves of quakes and issue warnings if the tremors are predicted to be powerful.
Primary waves travel faster than secondary waves, which are much more destructive - meaning that alarms about quakes can arrive moments before the earth starts to shake, just enough time to take cover.
1509 The view in Miyagi prefecture earlier today
1508 Small tsunami waves have hit the Philippines, but officials said there were no reports of damage or casualties as thousands of people fled the coasts.
Waves of between 30cm and 1m were recorded across the length of its east coast between 10am and 12.44pm (Irish time).
1505 Fire has engulfed a large waterfront area in northeastern Japan.
Houses and other buildings were ablaze across Kesennuma city in Miyagi prefecture, near Sendai city, footage from public broadcaster NHK showed.
The city, with a population of 74,000, has residential, light industry and fishing areas.
1500 There are an estimated 2,000 Irish citizens known to be living in Japan.
The Irish Embassy in Tokyo has been contacting those Irish citizens who are in the affected areas. There are no details on any Irish casualties at present.
Tánaiste and Minister for Foreign Affairs Eamon Gilmore has expressed his sympathy at the tragic loss of life and devastation.
1415 3,000 residents living near a nuclear plant in Fukushima prefecture, north of Tokyo, have been told to evacuate the area, Chief Cabinet Secretary Yukio Edano tells reporters.
1414 Below is the predicted direction and time of tsunamis caused by the Japan earthquake.
1409 The Los Angeles Times has put together a collection of high quality photographs taken over the past few hours in Japan.
1401 A seismological chart of the earthquake which hit Japan (below)
1351 Japanese police: Up to 300 bodies have been found floating in the water off the coast of the northestern city of Sendai.
1347 The water on the coast of Honolulu in Hawaii has receded significantly, exposing the sea floor. Live webcam feed here
1441 Tokyo's Narita airport has now partially resumed flights.
1339 The tsunami alert for Guam has been lifted.
1331 Latest info from the US Geological Survey - a 'shake map' displaying the varying intensity of the earthquake across Japan.
1326 The California Emergency Office says northern California - near Crescent City - is likely to see the largest tsunami waves on the US coast.
1324 Kyodo news agency is now reporting that a Japanese passenger train is unaccounted for following the tsunami.
1319 A live webcam feed from Kauai in Hawaii is available here
1313 Associated Press is reporting that tsunami waves have reached western Hawaiian islands.
1301 Japanese authorities say there have been no radiation leaks from a number of nuclear power plants affected by the quake.
1230 The International Atomic Energy Agency says it is seeking more information on condition of reactor buildings and cooling systems.
1228 Developments in the Western Pacific:
HAWAII
The tsunami is expected to hit the islands at 3am (1pm Irish time). Civil defence officials have ordered all coastal areas evacuated.
GUAM
Authorities ordered evacuations in low-lying areas and advised tourists in hotels to take shelter on the sixth floor and above.
GALAPAGOS ISLANDS
Ecuador's President Rafael Correa declared a state of emergency and urged coastal and island residents to evacuate fast to higher areas.
EASTER ISLAND
Luz Zasso, the mayoress of the remote Chilean territory in the South Pacific, said residents would evacuate to higher ground hours before a possible tsunami.
CHILE
President Sebastian Pinera called on Chileans to remain alert but continue with their daily routines.
1220 The International Atomic Energy Agency has said it has received information of a heightened state of alert at Fukushima Daiichi nuclear plant.
1218 The European Union has said it will mobilise 'all appropriate assistance' for Japan.
1210 Japanese police have said that at least 40 people have been killed and 39 are missing. Public broadcaster NHK has put the death toll at 44.
1205 The US State Department has moved its embassy operations in Japan to an alternate location.
1200 Electronics firm Sony has said it has closed six of its factories in the north of Japan.
1153 Detailed Pacific tsunami warnings available here
1147 'Tsunami Alert for New Zealand, the Philippines, Indonesia, Papua New Guinea, Hawaii, and others. Waves expected over the next few hours, caused by 8.9 earthquake in Japan,' reads an alert now being carried on Google search pages worldwide
1141 The earthquake struck just under 400km northeast of Tokyo, at a depth of 24.4km, according to the US Geological Survey (see below).
The initial quake was followed by more than a dozen aftershocks, one as strong as 7.1.
1133 Kyodo news agency is reporting that a ship carrying 100 people was swept away by the tsunami.
1130 '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,' said US President Barack Obama.
1126 Millions of people in greater Tokyo are stranded because the earthquake shut down the capital's subway system.
1125 Graphic from Yomiuri Shimbun in Tokyo showing the intensity of the earthquake as it was felt across Japan.
1110 New Zealand civil defence officials have now issued a tsunami warning and warned people to stay clear of beaches following a massive earthquake in Japan.
'A tsunami marine warning is in effect for New Zealand,' New Zealand Civil Defence, adding that no threat to land was expected when the tsunami arrives at around 5.23pm Irish time.
1108 Japan's Kyodo news agency is now reporting that 'an emergency core-cooling unit has been activated' at Fukushima nuclear plant.
Authorities are already dealing with a fire in the turbine building of Onagawa nuclear plant in Miyagi Prefecture.
1045 'The damage is so enormous that it will take us much time to gather data,' an official at the National Police Agency said.
The death toll has reached 32 including three in Tokyo. Among the dead are a 67-year-old man crushed by a wall and an elderly woman killed by a collapsed roof.
1039 Hawaii's civil defense agency ordered all coastal areas, including the main tourist hub Honolulu, evacuated by 2am local time (12pm Irish time). The first tsunami wave was expected to reach Hawaii at 3am local time.
1033 All national Red Cross and Red Crescent Societies in the region including the Philippines, Papua New Guinea and Pacific Islands weer mobilised to help their populations.
1029 The earthquake is a 'terrible reminder of the destructive power of nature', says British Prime Minister David Cameron.
'Everyone should be thinking of the country and its people and I have asked immediately that our Government look at what we can do to help.'
1026 Kyodo News is reporting that the fire broke out in the turbine building of Onagawa nuclear plant in Miyagi Prefecture.
1015 Australia and New Zealand, which had been on an initial tsunami warning list, have been removed.
1013 Kyodo news agency has reported that a fire has broken out at a nuclear plant in northeast Japan.
1010 British Airways and Virgin Airlines have cancelled flights from Heathrow to Tokyo.
1005 Marshall Islands has downgraded its tsunami alert, while Taiwan said the tsunami has hit without major impact.
1000 The death toll has reached 26, Japanese media reported.
0950 The US Pacific territory of Guam cleared its shore areas.
0941 Tsunami warning issued for parts of California, Oregon, Alaska.
0940 The International Atomic Energy Agency has said that four nuclear power plants closest to the earthquake have been safely shut down.
0930 Today’s earthquake was Japan's biggest ever and the seventh largest on record, according to the US Geological Survey data.
The largest was in Chile in 1960 when a 9.5 magnitude earthquake killed more than 1,600 people and left 2,000,000 homeless.
0927 The Department of Foreign Affairs has activated its Consular Crisis Centre to deal with public queries relating to the earthquake and tsunami. The dedicated number is 01-4180233.
0925 'An earthquake of this size has the potential to generate a destructive tsunami that can strike coastlines near the epicentre within minutes and more distant coastlines within hours,' said the Pacific Tsunami Warning Centre.
0922 Sirens have sounded in Hawaii warning residents to move away from coastal areas.
0920 Japanese media reports that the death toll has now reached 19.
0915 At least five people are reported to have died in Japan after the earthquake. There are reports that dozens of people are trapped under the rubble of a collapsed hotel.
Further massive waves also hit the coastal city of Sendai, and more are expected. Buildings collapsed in Tokyo and transport systems came to a halt following the quake.
An oil refinery near Tokyo is on fire, with dozens of tanks storing petroleum gas under threat.
Nuclear power plants have been shut down and 4m people are without electricity, although the Japanese Prime Minister said that no nuclear facilities had been damaged.
0910 The whole Pacific Rim region is now on tsunami alert, including Australia, South America, Hawaii, and Indonesia.
Residents in coastal areas of the Pacific coast of Russia, Taiwan and the Philippines are being moved to higher ground.
The Red Cross has said that the waves are higher than the highest points of some islands in the Pacific.
0900 A powerful earthquake with a magnitude of 8.9 in the Pacific Ocean off Japan's coast has triggered several tsunamis that have caused widespread devastation.
