Antarctic Ice Shelf Collapse Due to Waves

Research Review #1:

From time to time I will summarize new science research from recently published, or about-to-be published papers. Usually, notice of the research comes in the form of press releases from universities that are made available to the media. Here are some reports that the Arizona Daily Star apparently missed.

Antarctic Ice Shelf Collapse Possibly Triggered by Ocean Waves

Scripps Institution of Oceanography

Background: In the summer of 2007, Arctic sea ice melted more than it had previously. The media made much of that, but failed to mention that the same year, Antarctic sea ice reached the greatest extent ever recorded. You may also remember that in 2008, several large chunks of Antarctic sea ice broke off to become very large icebergs. The general media trumpeted this as evidence of global warming. Scripps has an alternative theory.

The research findings:

Storm-driven waves in the North Pacific break along the coastlines of North and South America where “they are transformed into very long-period ocean waves called ‘infragravity waves’ that travel vast distances to Antarctica.” The authors “propose that the southbound traveling infragravity waves may be a key mechanical agent that contributes to the production and/or expansion of the pre-existing crevasse fields on ice shelves, and that the infragravity waves also may provide the trigger necessary to initiate the collapse process.” “The study found that each of the Wilkins Ice Shelf breakup events in 2008 coincided with the estimated arrival of infragravity waves. The authors note that such waves could affect ice shelf stability by opening crevasses, reducing ice integrity through fracturing and initiating a collapse.”

Press release and photo:

https://scripps.ucsd.edu/news/2042

Does Global Warming Threaten Alpine Ecosystems?

Research shows that the combination of genetic diversity within and among alpine species and the high diversity of micro-habitats in alpine terrain precludes any profound effects of warming on alpine species survival. See analysis from CO2Science.org here:

http://www.co2science.org/articles/V13/N7/B3.php

The mammoths’ swan song revised

University of Copenhagen

The researchers claim that by using DNA in soil samples they found that mammoths existed back to between 10,500 and 7,500 years ago, and are therefore remained between 2,600 and 5,600 years after their supposed extinction from mainland Alaska. “Our findings show that the mammoth and the horse existed side by side with the first human immigrants in America for certainly 3,500 years and were therefore not wiped out by human beings or natural disasters within a few hundred years, as common theories otherwise argue.” The research does not address the ultimate cause of their disappearance.

Press release: http://www.eurekalert.org/pub_releases/2009-12/uoc-tms121409.php

Team finds subtropical waters flushing through Greenland fjord

Woods Hole Oceanographic Institution

“Waters from warmer latitudes — or subtropical waters — are reaching Greenland’s glaciers, driving melting and likely triggering an acceleration of ice loss…”

Press release: http://www.whoi.edu/page.do?pid=7545&tid=3622&cid=69134

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