Tsunami swirls near a port in Oarai, Ibaraki Prefecture (state) after Japan was struck by a strong earthquake off its northeastern coast Friday, March 11, 2011.
The tsunami that hit northern Japan today created an enormous whirlpool in a harbor off the east coast of that country. According to researchers, whirlpools aren't unusual after waves of this size.
The tsunami was triggered by an 8.9-magnitude earthquake that struck off the coast of Japan at 2:46 p.m. Tokyo time. Video footage shows a boat swirling in the massive eddy. It's not known whether anyone was on the vessel.
Based on eye-witness accounts and video in recent years, whirlpools probably occur with some regularity after large tsunamis, said Ruth Ludwin, a retired seismologist at the University of Washington in Seattle.
"Whirlpools have a big impact on the human imagination," Ludwin said. "They're very notable and very frightening. But from the perspective of the geological record, they don't leave any particular sign that has been recognized so far."
Whirlpools happen because of the interaction between rushing water and the geology of the coastline and seafloor, Ludwin said.
"Obviously there is a lot of water that is being pushed around, and it is interacting with the shape, the bathymetry, near the coastline," she said. [Album: Monster Waves]
The first images and videos of post-tsunami whirlpools came out of the 2004 Indian Ocean tsunami, Ludwin said. But eyewitness accounts from previous coastal quakes suggest that tsunami whirlpools are nothing new. One was reported in the great Lisbon earthquake of 1775, Ludwin said. The Haida people of the Queen Charlotte Islands off the coast of British Columbia have myths about a whirling wave of foam.
Apela Colorado, Ludwin's colleague with the Worldwide Indigenous Science Network in Hawaii, has identified a petroglyph in southeastern Alaska that seems to show a whirlpool in the body of a sea monster. In an abstract presented at the 2006 meeting of the Seismological Society of America, Colorado and Ludwin describe the native myths about that monster. According to ancient tales, they wrote, the creature "inundates canoes, makes the salt-water boil, swallows fishermen, pushes fish into a cave, and creates a canoe passage by flopping across a spit."
Sunday, March 20, 2011
Why Japan's Tsunami Triggered an Enormous Whirlpool Tại sao động đất Nhật bản gây ra nước xoáy lớn
Saif al-Islam Muammar Al-Gaddafi the future for Libya
Saif al-Islam Muammar Al-Gaddafi the future for Libya2
Libya Under Missile Attack - Li-bi bị tấn công tên lửa
Libya Under Missile Attack - Li-bi bị tấn công tên lửa
GUY RAZ, host:
From NPR News, this is special coverage of the military situation in Libya. I'm Guy Raz.
The United States and its allies at this hour are engaged in Libya.
President BARACK OBAMA: Today, I authorize the Armed Forces of the United States to begin a limited military action in Libya in support of an international effort to protect Libyan civilians. An action has now begun.
RAZ: That's President Obama speaking this afternoon in Brazil.
In Libya, French warplanes took the lead today in launching attacks against the forces of Moammar Gadhafi. The strikes were intended to stop Gadhafi's march against rebels in the eastern part of the country, near the city of Benghazi. Then came cruise missiles launched by American and British forces. More than a hundred of those missiles rained down, targeting Libyan air defenses.
European, American and Arab leaders met in Paris earlier today to discuss how to coordinate an intervention. Meanwhile, Gadhafi sent troops backed by tanks into the country's second largest city, the rebel stronghold of Benghazi.
We'll start today with NPR's Pentagon correspondent Tom Bowman who is in the studio with me. Tom, what do we know about the military campaign at this point?
TOM BOWMAN: Well, as you say, it started with the French taking on Libyan troops around Benghazi, the last rebel stronghold in the east and it was followed quickly by cruise missiles being fired by warships, British and U.S. warships in the Mediterranean, 110 cruise missiles, each have 1,000-pound warhead, taking out the radar sites, the missiles sites of Moammar Gadhafi so they can implement that no-fly zone. They wouldn't be able to fly safely through Libya without being targeted by these missiles.
RAZ: How could Moammar Gahhafi respond to this? I mean, this is a pretty big campaign now, more than 25 countries involved and presumably will get bigger over the coming days. I mean, how could he respond to these attacks?
BOWMAN: Well, one way he could respond is terrorism. I mean, clearly, he's been linked to terrorism in the past. The last time the U.S. took part in a military operation was in 1986 when there's Libyan complicity in the La Belle discotheque bombing in Berlin, which killed two U.S. soldiers and injured many others.
And two years we had the Lockerbie bombing, which Libyan agents took part in more than - nearly 200 people were killed in that bombing over Scotland. So there's concern particularly about terrorism. Also, he has a good amount of mustard agent, mustard that he could use either against rebels or against civilians. He - western hostages, he could play that card as well. So there were a lot of concerns here about what he could do now that he's cornered.
RAZ: Tom, Defense Secretary Robert Gates was not too keen on imposing a fly zone. Of course you remember just a few weeks ago at a congressional hearing he said, let me be clear, this is a military intervention. It seemed like he was also staking out his position here.
BOWMAN: Absolutely. He talked about loose talk of a no-fly zone. He think - he thought that people really didn't realize what this meant. He said it meant going to war. And, again, taking out those radars and missile sites that we're seeing right now.
But the question is, will this be enough? If you start that no-fly zone, and the U.N. resolution said no-fly zone plus all measures to go after Libyan forces. Will this be just the beginning?
Now, Gadhafi isn't overthrown, you could chop the country in half. You get a Benghazi on one side with the rebels, Tripoli with Gadhafi on the other. And then there's going to be a question of what do you do now? Do you arm the rebels? Do you send ground troops in? U.S. has said no ground troops. But, again, this could go on for a long time.
RAZ: That's NPR's Pentagon correspondent Tom Bowman who's following the latest on this story. We'll be hearing from Tom in the coming hours. Tom, thanks.
BOWMAN: You're welcome.
Saturday, March 19, 2011
WHO issues guidelines on radiation exposure - Hướng dẫn của Tổ chức Y tế thế giới về phơi nhiễm phóng xạ
WHO issues guidelines on radiation exposure - Hướng dẫn của Tổ chức Y tế thế giới về phơi nhiễm phóng xạ
 Logistics Spc. 2nd Class Robert Bannister carries a shovelful of sediment as he and his unit cleans up behind a damaged building in Hachinohe, Japan. About 17,000 U.S. military personnel are involved in relief operations in the country. GENEVA (Reuters) - In the wake of Japan's nuclear crisis, the World Health Organization (WHO) issued fresh guidelines on how to minimize exposure to radiation that can cause cancers, especially in children and young adults. |
Japan nuclear accident poses crisis for worker safety - Sự cố hạt nhân Nhật bản đe dọa an toàn tính mạng công nhân
Japan nuclear accident poses crisis for worker safety - Sự cố hạt nhân Nhật bản đe dọa an toàn tính mạng công nhân
Workers at the damaged Fukushima Daiichi nuclear plant could rapidly reach their annual radiation exposure limit and may have to be rotated out soon.
An aerial view of the damaged Reactor No. 4 at the Fukushima Daiichi nuclear power facility. (Reuters)
Bursts of radiation being released at the stricken Fukushima nuclear plant could mean workers there will have to be quickly rotated out, and some could rapidly reach their annual exposure limit, complicating efforts to contain Japan's continuing nuclear crisis.
"Those are pretty brave people," David Brenner, the director of the Center for Radiological Research at Columbia University Medical Center, said of the workers. "There are going to be some martyrs among them."
Disaster officials could face a grim choice: Scale back their containment efforts or allow workers to face radiation levels that could significantly increase their risk of cancer.
Reports on Thursday indicated that at times radiation was intense enough to exceed even Japan's newly raised annual limit in as little as an hour.
The new limit — 250 millisieverts — is five times the allowable exposure in U.S. nuclear plants and 125 times what workers typically receive each year.
That level of exposure raises the chances that workers will eventually die of cancer by 1 percentage point, according to John Boice, a cancer epidemiologist at Vanderbilt University and radiation safety expert.
Considering the scope of the disaster — and the fact that at least 20% of people already die of cancer — many workers may be willing to accept the danger. The situation becomes more complicated at higher doses, because radiation risk is cumulative. In other words, the risk of dying of cancer rises an extra percentage point with each additional 250 millisieverts.
It is not clear for how long the government will abide by its new limit.
There were conflicting reports about the amount of radiation the workers may have received so far. It also was not clear if the releases were planned and whether the workers were sheltered at the time.
At one point on Thursday, a level of 400 millisieverts per hour was recorded at the plant. That reading was an instantaneous measurement, and it was not clear how long that emission rate was sustained. But at that rate, a fully exposed worker would have to leave in 37 minutes, 30 seconds and not come back for a year to avoid exceeding the limit.
The Japanese government has tried to protect workers by keeping as few people on-site as possible, monitoring how much radiation they receive and limiting helicopter missions to drop water on the plant. Special clothing and respirators provide some protection from the damaging emissions.
"The main danger is gamma radiation," said Elmer Lewis, a nuclear plant safety expert at Northwestern University in Evanston, Ill. "Gamma can penetrate your body no matter what you're wearing out there. It's like a high-powered X-ray."
The plant workers are trained to react to crisis through simulated disasters, Lewis said.
But, he said, "there's really no way to anticipate what we're seeing here. They're professionals who are doing the best with what they have."
The most acute danger would come from a sudden release of radiation from which workers could not escape — an explosion, for example. That could cause radiation sickness, a devastating illness that is often fatal.
In the 1986 Chernobyl disaster in Ukraine, then part of the Soviet Union, the worst nuclear plant accident in history, workers who battled a weeklong fire were exposed to radiation at levels thousands of times higher than the Japanese yearly limit.
At first, people exposed to that much radiation might look normal. In a week, things change drastically.
"People's hair starts to fall out and the burns appear and the bone marrow damage starts," said Dr. Robert Peter Gale, a hematologist who flew to Moscow days after the accident to try to save workers airlifted there. He is scheduled to fly to Japan on Saturday to help with the Fukushima relief efforts.
Gale treated Chernobyl exposure victims with antibiotics and experimental hormones. In 13 cases, he performed bone marrow transplants in an attempt to revive their immune systems.
Of 600 workers present when the Chernobyl accident occurred, 134 developed radiation sickness, and 28 of those died within four months, according to the United Nations. Many of the rest have continued to battle health problems. Several developed cataracts.
The number of workers at the damaged Fukushima Daiichi plant during the crisis has varied from about 50 to 180, except for an hour or two when all workers had withdrawn.
Still, it is difficult to compare the accidents.
Some firefighters sent to the burning Chernobyl reactor later said they were not warned about the radiation danger, and many workers lacked protective suits and breathing devices. Soviet officials sent helicopters into the clouds of radioactive smoke to help douse the fire.
The actions of the power plant workers in Japan have already been described as heroic, and examples of heroism are common in such situations, said Dr. Fred Mettler, a University of New Mexico radiologist and advisor to the U.N. on radiation safety.
At one point during the Chernobyl disaster, he said, workers were conferring about how much water was in one reactor pool. No one knew the answer and their instruments couldn't tell them, he said. "An Armenian engineer slipped out and came back in 30 minutes. He said, 'There's 3 feet of water,' " Mettler said. "He did that on his own."
The engineer died soon after of acute radiation poisoning.
"Its always hard to tell what people are going to do," he said. "Workers have done remarkable things, some things you wouldn't expect."
Nuclear plant workers in the United States expressed a camaraderie with their Japanese counterparts, even as they puzzled over the response to the catastrophe. "I have a lot of empathy for the Japanese people, for those workers," said Charlie Arnone, 51, general manager of plant operations at the Waterford 3 facility on the Mississippi River in Killona, La. "They're clearly very dedicated folks."
Arnone, who has worked with nuclear energy since 1977, said he and other workers train according to federal Severe Accident Mitigation Guidelines, scenarios specific to each plant. They review what could happen if, for instance, they can't maintain the water level in a spent fuel pool.
"We might hook up things, basically fire nozzles that automatically spray. Then if that doesn't work, you can open up and try air cooling," Arnone said. "We just have different guidelines and tools. My understanding is the Japanese don't have that. We have all this equipment staged. We have a generator already set up, and we can pull water out of the river if we have to, to keep the core cool, the spent fuel cool."
Experts are focusing their concern on nuclear workers because the general population's exposure to radiation around the Fukushima Daiichi plant has so far been minimal.
The government quickly evacuated a 12-mile zone around the plant. Readings of radiation outside that area have remained low.
The utility that operates the plant, Tokyo Electric Power Co., has released gases laden with radioactive substances in small bursts to prevent the buildup of pressure inside the containment buildings. For now, the winds have cooperated in blowing much of the material out to the Pacific Ocean, where scientists say it settles in the water and is diluted into concentrations that pose little danger.
Even in Chernobyl, nobody in the general population suffered radiation sickness. The U.N. says that 6,500 cases of thyroid cancer can be attributed to the disaster, but because the cases were closely monitored and treated, only a few were fatal.
Those occurred mainly because people were not warned to stop drinking milk — the main way that dangerous quantities of radioactive iodine enter the body. The isotopes land on the grass, which is then eaten by cows, turning their milk radioactive.
"All they had to say was 'don't drink the milk,' " Boice said.
"In Japan, radioactive iodines are not going to be that big a deal," he said. "They won't let the milk into the food supply."
Photos: Crisis continues in Japan
alan.zarembo@latimes.com