Dust Bowl
The Dust Bowl was a period of severe dust storms that greatly damaged the ecology and agriculture of the American and Canadian prairies during the 1930s. The phenomenon was caused by a combination of natural factors and human-made factors: a failure to apply dryland farming methods to prevent wind erosion, most notably the destruction of the natural topsoil by settlers in the region. The drought came in three waves: 1934, 1936, and 1939–1940, but some regions of the High Plains experienced drought conditions for as long as eight years. It exacerbated an already existing agricultural recession.
The Dust Bowl has been the subject of many cultural works, including John Steinbeck's 1939 novel The Grapes of Wrath; the Dust Bowl Ballads of Woody Guthrie; and Dorothea Lange's photographs depicting the conditions of migrants, particularly Migrant Mother, taken in 1936.
Geographic characteristics and early history
The Dust Bowl area lies principally west of the 100th meridian on the High Plains, characterized by plains that vary from rolling in the north to flat in the Llano Estacado. Elevation ranges from in the east to at the base of the Rocky Mountains. The area is semiarid, receiving less than of rain annually; this rainfall supports the shortgrass prairie biome originally present in the area. The region is also prone to extended drought, alternating with unusual wetness of equivalent duration. During wet years, the rich soil provides bountiful agricultural output, but crops fail during dry years. The region is also subject to high winds. During early European and American exploration of the Great Plains, this region was thought unsuitable for European-style agriculture; explorers called it the Great American Desert. The lack of surface water and timber made the region less attractive than other areas for pioneer settlement and agriculture.The federal government encouraged settlement and development of the Plains for agriculture via the Homestead Act of 1862, offering settlers "quarter section" plots. With the end of the Civil War in 1865 and the completion of the first transcontinental railroad in 1869, waves of new migrants and immigrants reached the Great Plains and greatly increased the acreage under cultivation. An unusually wet period in the Great Plains mistakenly led settlers and the federal government to believe that "rain follows the plow" and that the region's climate had permanently changed. While initial agricultural endeavors were primarily cattle ranching, the harsh winters' adverse effect on the cattle, beginning in 1886, a short drought in 1890, and general overgrazing, led many landowners to increase the amount of land under cultivation.
Recognizing the challenge of cultivating marginal arid land, the U.S. government expanded on the offered under the Homestead Act, granting to homesteaders in western Nebraska under the Kinkaid Act and elsewhere in the Great Plains under the Enlarged Homestead Act of 1909. Waves of European settlers arrived in the plains at the beginning of the 20th century. A return of unusually wet weather seemingly confirmed a previously held opinion that the "formerly" semiarid area could support large-scale agriculture. At the same time, technological improvements such as mechanized plowing and mechanized harvesting made it possible to operate larger properties without increasing labor costs.
With insufficient understanding of the ecology of the plains, farmers had conducted extensive deep plowing of the Great Plains' virgin topsoil during the previous decade; this displaced the native, deep-rooted grasses that normally trapped soil and moisture even during periods of drought and high winds. The rapid mechanization of farm equipment, especially small gasoline tractors, and widespread use of the combine harvester contributed to farmers' decisions to convert arid grassland to cultivated cropland. During the drought of the 1930s, the unanchored soil turned to dust, which prevailing winds blew away in huge clouds that sometimes blackened the sky. These choking billows of dustnamed "black blizzards" or "black rollers"traveled cross-country, reaching as far as the East Coast and striking such cities as New York City and Washington, D.C. On the plains, they often reduced visibility to or less. Associated Press reporter Robert E. Geiger happened to be in Boise City, Oklahoma, to witness the "Black Sunday" black blizzards of April 14, 1935; Edward Stanley, the Kansas City news editor of the Associated Press, coined the term "Dust Bowl" while rewriting Geiger's news story.
The term "the Dust Bowl" originally referred to the geographical area affected by the dust, but today it usually refers to the event itself. The drought and erosion of the Dust Bowl affected that centered on the Texas Panhandle and Oklahoma Panhandle and touched adjacent sections of New Mexico, Colorado, and Kansas. The Dust Bowl forced tens of thousands of poverty-stricken families, who were unable to pay mortgages or grow crops, to abandon their farms, and losses reached $25 million per day by 1936. Many of these families, often called "Okies" because many of them came from Oklahoma, migrated to California and other states to find that the Great Depression had rendered economic conditions there little better than those they had left.
The combined effects of World War I and the disruption of the Russian Revolution, which decreased the supply of wheat and other commodity crops, increased agricultural prices; this demand encouraged farmers to dramatically increase cultivation. For example, in the Llano Estacado of eastern New Mexico and northwestern Texas, the area of farmland doubled between 1900 and 1920, then tripled between 1925 and 1930. The agricultural methods farmers favored during this period created the conditions for large-scale erosion under certain environmental conditions. The widespread conversion of the land by deep plowing and other soil preparation methods to enable agriculture eliminated the native grasses that held the soil in place and helped retain moisture during dry periods. Furthermore, cotton farmers left fields bare during the winter, when winds in the High Plains are highest, and burned the stubble as a means to control weeds before planting, thereby depriving the soil of organic nutrients and surface vegetation.
Drought and dust storms
After fairly favorable climatic conditions in the 1920s with good rainfall and relatively moderate winters, which permitted increased settlement and cultivation in the Great Plains, the region entered an unusually dry era in the summer of 1930. During the next decade, the northern plains suffered four of their seven driest calendar years since 1895, Kansas four of its 12 driest, and the entire region south to West Texas lacked any period of above-normal rainfall until record rains hit in 1941. When severe drought struck the Great Plains region in the 1930s, it resulted in erosion and loss of topsoil because of farming practices at the time. The drought dried the topsoil and over time it became friable, reduced to a powdery consistency in some places. Without indigenous grasses in place, the plains' high winds picked up the topsoil and created massive dust storms. The persistent dry weather caused crops to fail, leaving the plowed fields exposed to wind erosion. The Great Plains' fine soil eroded easily and was carried east by strong continental winds.The first recorded dust storm occurred on September 14, 1930. It was seen more as a meteorological anomaly at the time as it was unlike anything else ever recorded. Unlike a sand storm, the cloud was black or gray and rolled across the ground. Inside, visibility dropped to the point where people couldn't see their hand in front of their face.
On November 11, 1933, a very strong dust storm stripped topsoil from desiccated South Dakota farmlands in one of a series of severe dust storms that year. Beginning on May 9, 1934, a strong, two-day dust storm removed massive amounts of Great Plains topsoil in one of the worst such storms of the Dust Bowl. The dust clouds blew all the way to Chicago, where they deposited of dust. Two days later, the same storm reached cities to the east, such as Cleveland, Buffalo, Boston, New York City, and Washington, D.C. Dust worked its way into even well-sealed homes, leaving a coating on food, skin, and furniture. That winter, red snow fell on New England.
On April 14, 1935, known as "Black Sunday", the day started out clear and warm, with temperatures in the 80s and the air completely still, causing many people to let down their guard. However, a diving cold front from Canada kicked up mountains of dust in the turbulent air in the Dakotas and plowed south across the Great Plains at 60 mph. The only sign of the advancing storm was the snapping of static electricity and the flocks of screeching birds and rabbits streaming south; unlike other such storms, the winds didn't pick up until the dust cloud's leading edge arrived.
Denver-based Associated Press reporter Robert E. Geiger had been sent to "the dust sector" on assignment. His three-part story about Black Sunday marked the first appearance of the term Dust Bowl; it was coined by Edward Stanley, Kansas City news editor of the Associated Press, while rewriting Geiger's news story.
Much of the farmland in the Plains was eroded in the aftermath of the Dust Bowl. In 1941, a Kansas agricultural experiment station released a bulletin that suggested reestablishing native grasses by the "hay method". Developed in 1937 to speed up the process and increase returns from pasture, the "hay method" was originally supposed to occur in Kansas naturally over 25–40 years.
After much data analysis, the causal mechanism for the droughts can be linked to ocean temperature anomalies. Specifically, Atlantic Ocean sea surface temperatures appear to have had an indirect effect on the general atmospheric circulation, while Pacific sea surface temperatures seem to have had the most direct influence.