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Posts Tagged ‘paleomagnetism

“Hurricane season brings a humbling reminder that, despite our technologies, most of nature remains unpredictable”*…

Still, as Katarina Zimmer explains, an emerging science can help us improve our forecasts…

…  contemporary simulations suggest the Great Colonial Hurricane was a Category 3.5 storm, probably the strongest in recorded eastern New England history. (For reference, Sandy, which killed nearly 150 people and caused some $65 billion in damage in the United States, was technically no longer even a hurricane when it made landfall in the New York metro area in 2012.)

Scientists know about the Great Colonial Hurricane’s impact not only from written reports but curiously, also from hidden, physical impressions the long-ago storm left on the landscape.

At the bottom of a pond, Jeffrey Donnelly, a hurricane scientist at the Woods Hole Oceanographic Institution, and his colleagues found subtle, buried evidence of the storm that almost felled the Mather line. The researchers were collecting sediment cores from a lakebed on Cape Cod. The spot, known as Salt Pond, lies about a third of a mile from the ocean and has long been a place of mud. But in their core samples, they found a pinky finger-thick layer of pure ocean sand in layers that dated back to roughly 1635. The only thing that could have pulled that much beach material over the sand barrier and that far inland was a truly massive storm.

The cores revealed other clues, too. Although written accounts suggest the 1635 tempest was the strongest of its time, the exhumed samples showed it wasn’t the only intense storm in the area. Donnelly found evidence for 10 major storms in the area between 1400 and 1675—a surprising toll, given that major hurricanes are virtually unheard of this far north today. The fact that hurricanes were much more frequent in the past begs the question of why, and whether these levels of storm activity could someday return.

Which is why researchers like Donnelly are traipsing along coastlines and digging in the muck. They hope their relatively new branch of science, paleotempestology (the study of old storms), can use these buried traces of long-gone winds to augur ancient patterns. Patterns that might also help us predict the weather that lies ahead…

Paleotempestology promises to uncover patterns of historical hurricanes—to better predict destructive weather of the future. More at: “The Secret Messages in Ancient Storms,” (or here) from @katarinazimmer in @NautilusMag.

* Diane Ackerman

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As we muse on the meteorological, we might send exploratory birthday greetings to Bernard Brunhes; he was born on this date in 1867. A geophysicist, he is known for his pioneering work in paleomagnetism, in particular, his 1906 discovery of geomagnetic reversal [see here]. The current period of normal polarity, Brunhes Chron, and the Brunhes–Matuyama reversal are named for him.

Brunes made his discovery in a way that presaged the work of paleotempestologists: he found volcanic lava and clay samples that recorded the Earth’s inversion of its magnetic field.

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