Title: Did hurricanes blow dinosaurs away?
Subject(s): HURRICANES; DINOSAURS; EMMANUEL, Kerry
Source: Science News, 9/23/95, Vol. 148 Issue 13, p204, 1/4p
Abstract: Reports on the development of a theory proposing that
monster hurricanes may have triggered the extinction of dinosaurs.
Proposal of the theory by scientist Kerry A. Emmanuel.
AN: 9510094863
ISSN: 0036-8423
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Database: MasterFILE Elite

Section: Earth Science

DID HURRICANES BLOW DINOSAURS AWAY?

Pity the poor dinosaurs. Though the immense saurians and many of their
neighbors disappeared from the planet 65 million years ago, scientists
never tire of dreaming up ways to kill off the beasts.

The newest theory, proposed by Massachusetts Institute of Technology
atmospheric scientist Kerry A. Emanuel and his colleagues, revolvers
around monster hurricanes called hyper-canes. While studying factors
that limit hurricane size, Emanuel recognized that tropical storms
could, in theory, grow much larger than they do at present if ocean
water warmed to 50 degrees C, almost double current temperatures in
the tropics. Ocean water does not get that warm under normal
conditions, but a large meteorite impact into the ocean or a major
volcanic eruption in shallow water could drive temperatures into the
hypercane zone, according to simulations done with a computer model of
the atmosphere, the scientists report in the July 20 JOURNAL OF
GEOPHYSICAL RESEARCH.

Therein lies the dinosaur connection. Emerging evidence suggests that
a large extraterrestrial body hit the Gulf of Mexico at the end of the
Cretaceous period, about the same time as the mass extinction recorded
in the fossil record. The crash could have warmed water enough to
spark a series of hyper-canes that reached altitudes of 45 kilometers,
well up into the stratosphere. Normal hurricanes top out at the base
of the stratosphere, about 19 kilometers up.

Because of their height, the storms could have transported water
vapor, ice particles, and dust into the stratosphere, where they would
block out sunlight and decimate the life-protecting ozone layer,
speculate the researchers. "The idea is a little far-fetched," admits
Emanuel. "But I don't think it's so far-fetched as to be outrageously
unlikely."
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Source: Science News, 9/23/95, Vol. 148 Issue 13, p204, 1/4p.
Item Number: 9510094863
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