•iO-Laucastar Farming, Saturday, February 14,1987
Remote Sensing Leeds
Scientists To Prehistoric
Mien Footpaths
BOULDER, Colo. - From the
ground, most of the footpaths
around the prehistoric Indian
settlements in northeastern Costa
Rica are invisible, blanketed under
many feet of volcanic ash and thick
tropical vegetation.
From the sky, it’s an entirely
different picture. On an orbiting
satellite and aboard high-flying
planes, electronic remote-sensing
equipment visually peels away the
blanket, revealing images from
wavelengths of the elec
tromagnetic spectrum that can’t
be seen with the human eye.
Verified on Ground
Combined with verification from
scientists on the ground, the
images point the way to the paths.
As a result, University of Colorado
scientists are adding swiftly and
steadily to their knowledge of a
remarkably self-sufficient, stable
culture that flourished for some
3,500 years before the Spanish
Conquest in the 1500 s.
The ancient agrarian Indians
lived on the shores of Lake Arenal,
at the base of 5,358-foot Arenal
Volcano, about 2,000 years longer
than any other society previously
identified in that region.
They had their problems with the
volcano, which has had at least
nine big eruptions over the past
4,000 years. The last major one was
about A.D. 1500. An eruption in 1968
killed 68 people, and another could
occur “in the next couple of cen
turies,” says Payson D. Sheets, the
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Colorado anthropologist
directs the Arenal project.
Although eruptions have
periodically plagued Arenal-area
citizens, they’ve been a boon to
Sheets and his team. Volcanic ash
has helped preserve artifacts, and
the definable layers of ash have
helped establish precise dates for
events.
But for Sheets, the real ex
citement has come from the
remote-sensing devices on the
National Aeronautics and Space
Administration’s Landsat IV
satellite and the agency’s specially
equipped planes.
“Nobody’s ever traced
prehistoric footpaths this way
before,” Sheets says. “It’s nice not
to have such a burden of tradition,
but to do something brand-new. It
really is a new window on the
past.”
“Remote sensing may soon be as
valuable as radiocarbon dating,”
says a key member of the Arenal
team, NASA anthropologist
Thomas L. Sever, a remote
sensing expert who is now a doc
toral candidate at the University of
Colorado.
Most Paths Ancient
During their July dig, Sheets and
his crew checked out, through
excavation, little lines on the
remote-sensing photographs to see
if they really were ancient paths.
Most were; a few were old roads of
less scientific interest.
(Turn to Pageßl2)
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St. Valentine's Day offers an opportunity to send cards and tokens of affection to loved
ones. Homemade Valentines are especially appreciated on this day for loved ones. If
you'd like to surprise your mom and dad with a card, make up your own, or write a
message in the heart above. You can clip it out of the paper with scissors and color it in
with crayons or magic markers. When you’re finished, surprise your parents with a hug,
a kiss and the special card you've made just for them.
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