3:00 pm: Tragedy oftentimes produces the most compelling writing -- and the online edition of Spiegel Online is one of the best showcases of the genre. Here, from the site, is a Cordula Meyer story on the new ghost towns of Japan, springing up in the vicinity of the embattled nuclear reactors.
Also from the same site, a series on nuclear no-go zones, that takes you beyond the Chernobyls and Fukushimas and shows you just how dangerous, and how vast, the radioactive hazard really is.
1:15 pm: The economic damage from Japan's massive earthquake and tsunami last month is likely to be worse than first thought as power shortages curtail factory output and disrupt supply chains, the country's economics minister warned on Tuesday.
The Bank of Japan governor said the economy was in a "severe state," while central bankers were uncertain when efforts to rebuild the tsunami-ravaged northeast would boost growth, according to minutes from a meeting held three days after a record earthquake struck Japan on March 11.
12:50 pm: Tokyo Electric Power Company chief takes upping of nuke crisis severity 'extremely seriously'
12:30: pm: Kyodo News reports that a quake, pegged at magnitude 6.3, rocked the Fukushima and Ibaraki prefectures in northeastern and eastern Japan early this afternoon local time. The quake came in the sake of another, magnitude 6.4, that rocked Chiba Prefecture, east of Tokyo, and one of magnitude 5.6 quake that rocked Nagano Prefecture in central, earlier this morning, local time.
12:15 pm: So what does it mean, to say that Japan has upgraded the severity of its nuclear crisis to a seven, on par with Chernobyl? The Sydney Morning Herald speaks to Prof Stephen Lincoln to find answers. The relevant quote:
Chemistry and physics professor Stephen Lincoln, of Adelaide University, said the main worry was the food stock in the ocean, where much of the radioactive material was being released.
While one of the radioactive substances, iodine-131, had a half-life of nine days, two others - caesium-137 and strontium-90 - could be more harmful in the long term as they had half-lives of 30 years, he said.
A half-life is the time taken for half of a sample of a radioactive isotope to decay into other materials.
"[People] should not venture into the ocean [where the radioactive materials are being released]; they should not eat any fish or seaweed from the ocean.
"The living species likely to be most affected are shellfish because they are stationary whereas fish that swim may pass through the area and out again. The shellfish such as mussels, oysters and clams certainly accumulate high levels of radioactivity.
"If they can stop the leaks, then the ocean can disperse the radioactivity until it becomes no more than background."
11:45 am: Workers have been struggling to prevent a nuclear disaster at Japan's Fukushima Daiichi nuclear plant. Here's a graphic representation by the Wall Street Journal that explains the current status of each of the six reactors.
11:30 am: Level 7 accidents on the International Nuclear Event Scale correspond to the release into the external environment of radioactive materials equal to more than tens of thousands of terabecquerels of radioactive iodine 131. One terabecquerel equals 1 trillion becquerels.
11:00 am: World's worst nuclear incidents
* Level 7: Chernobyl, Ukraine, 1986 - explosion and fire in operational reactor, fallout over thousands of square kilometres, possible 4,000 cancer cases
* Level 7: Fukushima, 2011 - tsunami and possibly earthquake damage from seismic activity beyond plant design, leading to...?
* Level 6: Kyshtym, Russia, 1957 - explosion in waste tank leading to hundreds of cancer cases, contamination over hundreds of square kilometres
* Level 5: Windscale, UK, 1957 - fire in operating reactor, release of contamination in local area, possible 240 cancer cases
* Level 5: Three Mile Island, US, 1979 - instrument fault leading to large-scale meltdown, severe damage to reactor core
10:00 am: Although the Japanese incident now equates to Chernobyl on the international scale, the two accidents are different in a number of important ways. In Chernobyl it was the reactor core itself that exploded, releasing a huge amount of radioactive material in a very short space of time. Fukushima experienced a less critical hydrogen explosion.
9:30 am: A month has elapsed since the emergency at Fukushima began. But what exactly has gone on there and what are the priorities now? BBC analyzes what needs to be done in Fukushima
9:00 am: It was the Cold War. Within days, the name 'Chernobyl' had become a byword across the world for Soviet bungling -- and callousness, since Moscow, obsessed by secrecy, did not come clean about the disaster for nearly 36 hours. Postcard from Chernobyl: vision of Apocalypse
8:30 am: A magnitude 6.3 earthquake occurred offshore near Chiba prefecture in eastern Japan at 8.08 a.m. local time Tuesday, Xinhua quoted Japan Meteorological Agency as stating.The epicentre of the quake was located some 30 km under the sea of the eastern prefecture in eastern Honshu, said the agency, however, adding the quake poses no tsunami risk.8:00 am: The rating of the accident at the Fukushima Daiichi nuclear plant was raised to 7, the worst on an internationally recognised scale, from a 5-rating. Japan said this reflects the initial severity of the crisis and not the current situation.
Right at this moment, we are still trying to control this accident, and the nuclear reactors are not stable yet - Hidehiko Nishiyama
"This is a preliminary assessment, and is subject to finalisation by the International Atomic Energy Agency," said an official at the Nuclear and Industrial Safety Agency (NISA), the government's nuclear watchdog, which made the announcement with the Nuclear Safety Commission.
