Ice shelf breaks away in Canadian Arctic

Ice shelf breaks off in Arctic

A massive 19-square-mile ice shelf in Canada’s northern Arctic has broken away and is floating in the Arctic Ocean, the latest sign of rapid climate change in the remote region, a team of scientists said Tuesday.

They said the Markham Ice Shelf – one of just five remaining ice shelves in the Arctic – split away from Ellesmere Island in early August. They also said two large chunks totaling 47 square miles had broken off the nearby Serson Ice Shelf, reducing it in size by 60%.

Derek Mueller, an Arctic ice shelf specialist at Trent University in Ontario, said the total amount of ice lost from the shelves this summer totaled 83 square miles.

Measles vaccine not tied to autism

New research further debunks any link between measles vaccine and autism, work that comes as the nation is experiencing a surge in measles cases fueled by children left unvaccinated.

Years of research with the measles, mumps and rubella vaccine, better known as MMR, have concluded that it doesn’t cause autism. Still, some parents’ fears persist, in part because of one 1998 British study that linked the vaccine with a subgroup of autistic children who also have serious gastrointestinal problems.

In the new study, published Wednesday in the online journal PLoS ONE, the researchers rigorously retested that finding, concluding that there is no evidence that MMR plays any role.

At age 2,100, wall stands tall

Israeli archaeologists unveiled on Wednesday a 2,100-year-old Jerusalem perimeter wall – along with beer bottles left behind by 19th century researchers who first discovered the stone defenses.

The wall, on Mount Zion at the southern edge of Jerusalem’s Old City, dates back to the Second Jewish Temple, which was destroyed by the Romans in AD 70.

The 10 1/2 -foot-high wall was not supported by any mortar or other bonding material and formed part of a 3 1/2 -mile-long fortification around the city, said Yehiel Zelinger, who headed the excavation for the Israel Antiquities Authority.

British archaeologists surveyed the site in the 19th century, leaving behind a shoe, and beer and wine bottles, which Zelinger’s team found and put on display on Wednesday.

Father’s age adds to bipolar risk

Children born to older fathers face a greater chance of developing bipolar disorder, according to one of the largest studies linking mental illness with advanced paternal age.

The risks started increasing around age 40 but were strongest among those 55 and older, according to the study led by researchers at Sweden’s Karolinska Institute.

The leading theory is that older men’s sperm may be more likely to develop mutations. Even so, the odds of a person becoming bipolar are so low that the study’s authors said it shouldn’t dissuade older men from becoming fathers.

Climate change threatens sequoias

Federal researchers are warning that warming temperatures could soon cause California’s giant sequoia trees to die off more quickly unless forest managers plan with an eye toward climate change and the impact of a longer, harsher wildfire season.

Hot, dry weather over the last two decades already has contributed to the deaths of an unusual number of old-growth pine and fir trees growing in Yosemite and Sequoia National Parks, according to recent research from the U.S. Geological Survey.

In the next decade, climate change also could start interfering with the giant sequoias’ ability to sprout new seedlings, said Nathan Stephenson, one of several scientists speaking Thursday at a government agency symposium on how global warming could affect the Sierra Nevada.

From Times staff and wire reports