Science Tuesday - Plate Tectonics, Genetic Testing, and Water on a Saturn Moon?

One day after the magnitude 9.2 earthquake on March 27, 1964, a section of an Anchorage street was several feet higher than another section. It is still the most powerful earthquake ever in North America.


A '64 Quake Still Reverberates
By Henry Fountain, The New York Times, April 7, 2014

When a strong earthquake rocked northern Chile on April 1, scientists were quick with an explanation: It had occurred along a fault where stresses had been building as one of the earth’s crustal plates slowly dipped beneath another. A classic low-angle megathrust event, they called it.

Such an explanation may seem straightforward now, but until well into the 20th century, scientists knew relatively little about the mechanism behind these large seismic events. But that all changed when a devastating quake struck south-central Alaska on March 27, 1964, nearly 50 years to the day before the Chilean quake.

Studies of the great Alaskan quake — undertaken largely by a geologist who, when he began, knew little about seismology — revealed the mechanism by linking the observed changes in the landscape to what was then a novel theory, plate tectonics.

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Fearing Punishment for Bad Genes
By KIRA PEIKOFF, The New York Times, APRIL 7, 2014

About 700,000 Americans have had their DNA sequenced, in full or in part, and the number is rising rapidly as costs plummet — to $1,000 or less for a full genome, down from more than $1 million less than a decade ago.

But many people are avoiding the tests because of a major omission in the 2008 federal law that bars employers and health insurers from seeking the results of genetic testing.

The Genetic Information Nondiscrimination Act, known as GINA, does not apply to three types of insurance — life, disability and long-term care — that are especially important to people who may have serious inherited diseases. Sponsors of the act say that they were well aware of the omission, but that after a 14-year effort to write and pass the law, they had to settle for what they could get.

That leaves many patients who may be at risk for inherited diseases fearful that a positive result could be used against them.

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Enceladus as viewed from NASA’s Cassini spacecraft. Gravity measurements taken by the craft align with the presence of a sea 20 to 25 miles below the moon’s surface, scientists say.

Under Icy Surface of a Saturn Moon Lies a Sea of Water, Scientists Say
By KENNETH CHANG, The New York Times, APRIL 3, 2014

Inside a moon of Saturn, beneath its icy veneer and above its rocky core, is a sea of water the size of Lake Superior, scientists announced on Thursday.

The findings, published in the journal Science, confirm what planetary scientists have suspected about the moon, Enceladus, ever since they were astonished in 2005 by photographs showing geysers of ice crystals shooting out of its south pole.

“What we’ve done is put forth a strong case for an ocean,” said David J. Stevenson, a professor of planetary science at the California Institute of Technology and an author of the Science paper.

For many researchers, this tiny, shiny cue ball of a moon, just over 300 miles wide, is now the most promising place to look for life elsewhere in the solar system, even more than Mars.

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