cultivation of the prairie grassland
began to replace cattle ranching. The
carpet of buffalo grass was turned
under and homesteaders planted
wheat, barley, oats and even cotton in
some areas.
A huge market for grains and fibers followed the end of World War I
in 1918, as Europe struggled to get
back on its feet. Driven by a speculative market overseas and new tractor
technology at home, Great Plains farmers used huge gang plows to plow and
plant more and more of the prairie
grasslands. And the climate across
the Great Plains cooperated.
Then, beginning in 1929-30,
double catastrophes hit Great Plains’
farmers. The Wall Street crash of Oct.
29, 1929, sent banks failing all across
the region, many having loaned farmers money to purchase farm equipment and land. In 1930, the 20-inch
isohyet moved eastward 300 miles and
intense drought came to the region,
creating the infamous Dust Bowl.
Throughout the decade of the
1930s, an unusual drying wind pattern developed across the Great Plains
and dependable regional rains seldom
came. Even when it rained, drying
Bowl stretched westward to the
Rockies and eastward nearly to Minnesota, Iowa, Missouri and Arkansas.
Meteorological causes of the Dust
Bowl escaped scientists until rather
recently. Beginning in the 1960s, scientists began studying El Niño and its
effects on floods and droughts in
South America. The study of this cyNeal G.
clic warming of the surface of the
Lineback
Pacific Ocean, followed by cooling
phase called La Niña began to explain
radical climatic behaviors throughout the Western Hemisphere and beyond.
Scientific evidence increasingly
Using data from ships logs,
points to the oceans as a main influNASA’s Siegfried Schubert and his
ence in radical changes in the earth’s
colleagues recently discovered that
climate. The most recent findings induring the 1930s tropical Pacific Ocean
volve the 1930’s Dust Bowl in the U.S.
surface temperatures were much
Great Plains. Noted as the most devcolder than normal (Science, Mar. 19,
astating climatic event in the last cen2004). At the same time, waters of the
tury, the causes of the Dust Bowl
tropical Atlantic were much warmer
escaped explanation until recently.
than normal. The result was a weakThe Dust Bowl refers to a Great
ened storm pattern across the SouthPlains region stretching from South
west and Great Plains. Whereas counTexas to eastern Montana and North
terclockwise cyclonic storms normally
Dakota. This geographic region is
brought Gulf moisture into the Plains,
known for the radical fluctuations of
the weakened pattern did not.
its annual precipitation. During an
Now scientists are following a trail
average year, precipitation hovers
to find the direct causes of the ocean
around 20 inches (51
surface temperature
cm.); during dry years,
differences and unA Dusty Situation
however, totals can be
usual storm pattern
h
y
o
e
s
t
nch i
half that amount. Such
that resulted in the
20 i
areas have a steppe cliDust Bowl. What
mate, where natural
caused the extreme opgrasslands proliferate,
posite ocean temperathe sort of landscape that
ture patterns to deoriginally attracted
velop at the same time
cattle ranchers to the
in the Atlantic and PaGreat Plains in the 1800s.
cific oceans? Was it just
The 20-inch isohyetcoincidental that they
the line connecting
happened simultapoints receiving 20
neously? Or were those
1930s Dust Bowl Core
inches of precipitationpatterns related to
generally runs northsome other event in the
1930s Dust Bowl Region
south through the Great
Arctic? Or in Africa?
Greater than and equal
Geography in the News 5/28/04
Plains, approximating
Or South Asia? Finally,
to 20 inches of average P. Larkins ©2004
the 100th meridian. East
can we come to predict
annual precipitation
of the line, places receive
such devastating climore precipitation,
winds kept the soil consistently dry.
matic phenomena in the future? The
while west of the line places receive
Loose soil from the plowed fields creanswers await our scientific sleuths.
less than 20 inches. On average, it
ated massive dust storms across the
And that is Geography in the
takes about 20 inches of annual moisregion, literally ruining thousands of
News™. May 28, 2004. #730.
ture to grow a crop of wheat.
prosperous farms and bankrupting
(The author is a Geography Professor
When homesteading settlement
entire towns. The center of the Dust
and
Dean of Arts and Sciences, Appalabegan in earnest on the western Great
Bowl was near Guymon, located in
chian
State University, Boone, NC.)
Plains in the late 1800s and early 1900s,
the Oklahoma panhandle, but the Dust
Geography
in the
News™
THE DUST BOWL
AND THE OCEANS
© 2004 maps.com