Plains in the late 1800s and early 1900s,
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
the Oklahoma panhandle, but the
Dust 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
Neal G.
South America. The study of this cyLineback
clic warming of the surface of the
Pacific Ocean, followed by cooling
phase called La Niña began to explain
radical climatic behaviors throughout the Western Hemisphere and beScientific evidence increasingly
yond.
points to the oceans as a main influUsing data from ships logs,
ence in radical changes in the earth’s
NASA’s Siegfried Schubert and his
climate. The most recent findings incolleagues recently discovered that
volve the 1930’s Dust Bowl in the U.S.
during the 1930s tropical Pacific Ocean
Great Plains. Noted as the most devsurface temperatures were much
astating climatic event in the last cencolder than normal (Science, Mar. 19,
tury, the causes of the Dust Bowl
2004). At the same time, waters of the
escaped explanation until recently.
tropical Atlantic were much warmer
The Dust Bowl refers to a Great
than normal. The result was a weakPlains region stretching from South
ened storm pattern across the SouthTexas to eastern Montana and North
west and Great Plains. Whereas counDakota. This geographic region is
terclockwise cyclonic storms normally
known for the radical fluctuations of
brought Gulf moisture into the Plains,
its annual precipitation. During an
the weakened pattern did not.
average year, precipitation hovers
Now scientists are following a trail
around 20 inches (51 cm.); during dry
to find the direct causes of the ocean
years, however, totals
surface temperature
A Dusty Situation
can be half that
differences and unamount. Such areas
usual storm pattern
h isohyet
c
n
i
20
have a steppe climate,
that resulted in the Dust
where natural grassBowl. What caused the
lands proliferate, the
extreme opposite ocean
sort of landscape that
temperature patterns to
originally attracted
develop at the same
cattle ranchers to the
time in the Atlantic and
Great Plains in the
Pacific oceans? Was it
1800s.
just coincidental that
The 20-inch isothey happened simulhyet-the line connecttaneously? Or were
ing points receiving 20
those patterns related
1930s Dust Bowl Core
inches of precipitationto some other event in
1930s Dust Bowl Region
generally runs norththe Arctic? Or in Afsouth through the
rica? Or South Asia? FiGreater than and equal Geography in the News 5/28/04
Great Plains, approxito 20 inches of average P. Larkins ©2004
nally, can we come to
mating the 100th meannual precipitation
predict such devastatridian. East of the line,
ing climatic phenomplaces receive more precipitation,
winds kept the soil consistently dry.
ena in the future? The answers await
while west of the line places receive
Loose soil from the plowed fields creour 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.)
Geography
in the
News™
THE DUST BOWL
AND THE OCEANS
© 2004 maps.com