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Tsunami
Officials reject concerns over 500 percent radiation increase on California beach.
Health officials in California are now telling residents not to worry after a video uploaded to the internet last month seemed to show high levels of radiation at a Pacific Coast beach.
The video, “Fukushima radiation hits San Francisco,” has been viewed nearly half-a-million times since being uploaded to YouTube on Christmas Eve, and its contents have caused concern among residents who fear that nuclear waste from the March 2011 disaster in Japan may be arriving on their side of the Pacific Ocean.
Throughout the course of the seven-minute-long clip, a man tests out his Geiger counter radiation detector while walking through Pacifica State Beach outside of San Francisco. At times, the monitor on the machine seems to show radiation of 150 counts-per-minute, or the equivalent of around five times what is typically found in that type of environment.
After the video began to go viral last month, local, state and federal officials began to investigate claims that waste from the Fukushima nuclear plant has washed ashore in California. Only now, though, are authorities saying that they have no reason to believe that conditions along the West Coast are unsafe.
The Half Moon Bay Review reported on Friday that government officials conducted tests along California’s Pacific Coast after word of the video began to spread online, but found no indication that radiation levels had reached a hazardous point.
“It’s not something that we feel is an immediate public health concern,” Dean Peterson, the county environmental health director, told the Review. “We’re not even close to the point of saying that any of this is from Fukushima.”
According to the Review’s Mark Noack, counts-per-minute does indeed measure radiation, but “does not directly equate to the strength or its hazard level to humans.” And while the paper has reported that testing conducted by Peterson’s department on their own Geiger counters has since revealedradiation level of about 100 micro-REM per hour, or about five times the normal amount, officials are confident that there is nothing to be concerned about.
“Although the radiation levels were clearly higher than is typical, Peterson emphasized that it was still not unsafe for humans,” Noack wrote. “A person would need to be exposed to 100 microREMs of radiation for 50,000 hours before it surpassed safety guidelines by the Occupational Safety and Health Administration, he explained.”
Even so, officials are still uncertain as to why those levels — even if they are relatively safe — seem to be five-times higher than what is expected. Peterson told the Review he was “befuddled” over the ordeal, but suggested the culprit could be something not too sinister — such as red-painted eating utensils buried on the beach.
“I honestly think the end result of this is that it’s just higher levels of background radiation,” he said.
Researchers at the Geiger Counter Bulletin website have since tried to make sense of the reading on their own, and agree that the levels being detected are several times over what should be expected. According to a post on their website from this weekend, however, an independent testing of soil taken from near Pacifica State Beach tested positive for some radioactive material — but nothing that would have come from Fukushima.
The results of testing conducted by California’s Department of Public Health are expected to be announced later this week.
Scientists Find Evidence of Ancient Tsunami in Switzerland.
Researchers say they’ve found good evidence that it has happened before. In the sixth century — the age of King Arthur, Mohammed and the bubonic plague — a bishop named Gregory of Tours noted an unusual event in Geneva. In 563, he wrote, a cascade of rocks plunged into the Rhone River, generating a wave of water that “overwhelmed with a sudden and violent flood all that was on the banks as far as the city of Geneva,” over 40 miles away, according to the New York Times.
Historians reading Gregory’s story, which is backed up by other ancient texts, have suspected for quite some time that something akin to a tsunami had hit Lake Geneva.
Now, there may be science to prove it. On the bottom of the lake, nearly 1,000 feet down, researchers from the University of Geneva have discovered a massive, 16-foot deep deposit of sediment, six miles long and three miles wide. Taking samples from bits of wood and leaves stuck in the sludge, the scientists concluded that the sediment dates from between the late fourth and early seventh century. They suspect this may have been what was left of the rocky mass that Gregory reported nearly 1,500 years ago. Using computer simulations, they estimate that the effect of that much material plunging into the water would have caused a 26-foot high tsunami wave which would have reached Geneva in about 70 minutes.
What caused the rocks to fall into the river in the first place? It may have been an earthquake, say scientists. They also say lakeside dwellers should wipe that smug, not-tsunami-fearing look off their faces. “People think, ‘Oh, lucky us, we live near a lake — we don’t have any such threat,’ ” Dr. Guy Simpson of the University of Geneva told the New York Times. “This reminds people that hey, hang on, these things have happened in the past, and quite likely will happen again.”
Head on over to the New York Times website to check out a graphic illustrating how the Swiss tsunami may have unfolded. You can also listen to an interesting discussion with the article’s author, Henry Fountain, and find out what became of 6th century Geneva.
If you’re looking to bone up on ancient natural disasters, here’s a primer on a few lesser-known ones:
1. The Plague of Justinian
In 541-542 A.D., a tiny bacteria swept across the ancient world, killing as many as 100 million people. It’s named after Justinian, emperor of the Eastern Roman Empire at the time, who contracted the disease but did not die from it. We can all give thanks to Alexander Fleming for discovering that little mold penicillin in 1928 and ensuring this (probably) won’t happen again.
2. The Antioch Earthquake
The 6th century was not a great time for humanity in general. In 526 A.D., a devastating earthquake struck the city of Antioch, in present-day Turkey, killing some 250,000 people. The quake lifted the city’s port up by more than three feet and caused fires to break out, destroying what remained of the metropolis. Antioch, once a great outpost of the Byzantine Empire, was reduced to rubble in the disaster.
3. The Alexandria Tsunami
On July 21, 365 A.D., a magnitude 8.0 quake hit the island of Crete, generating a tsunami that swept across the Mediterranean towards the port city of Alexandria. The water pushed the port’s giant ships inland into the city and deposited them on top of buildings. Tens of thousands of people lost their lives.
This earthquake hit modern-day Iran on Dec. 22, 856 A.D., causing some 200,000 deaths, including 45,000 in the Persian city of Damghan.
During the Peloponnesian War (431-404 B.C.), Athens was struck down by a plague which may have wiped out as much as a third of the city-state’s population. Historians debate whether the epidemic contributed to Athens’ loss of the war to Sparta and the Peloponnesian league. In the city-state itself, however, the plague had a number of well-documented social effects. The Greek historian Thucydides recorded that it changed peoples’ attitudes toward the social order and money — with citizens spending and breaking the law with impunity.
Source: Time.com
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