Geoscience Reference
In-Depth Information
eighteenth-century drought over the southern Plains and Mexico (including 'El
Año de Hambre'), the seventeenth-century Pueblo drought over the Southwest, the
early seventeenth-century Jamestown drought in Virginia, and the sixteenth-century
megadrought across North America. We also discuss the Aztec drought of 'One
Rabbit' in the mid-fifteenth century, the late thirteenth-century Great Drought first
documented and discussed by Douglass, and the prolonged droughts contemporane-
ous with the Classic Period decline in Mesoamerica late in the first millennium AD.
Many of the wettest years now evident in the North American PDSI reconstructions
also had significant social consequences, including the early nineteenth-century plu-
vial, one of the wettest episodes in the tree-ring record for western North America
in 500 years (Fig. 10.6 ) .
In the dendroclimatic perspective of the past 500 years, the twentieth century
was unusually wet, in spite of the Dust Bowl and 1950s droughts. The nineteenth
century was drier, punctuated by several prolonged droughts that we know had sig-
nificant socioeconomic and environmental impacts, magnified in part by human
activities (Fig. 10.6 ) . The so-called 'Great Die-Up' during the blizzards of 1886-
1887 occurred during widespread drought in the central and northern Great Plains
from 1886 through 1890 (Fig. 10.7 ) . The drought appears to have been most severe
over the Dakotas and Canadian prairies; it is reported to have degraded the forage
value of the grasslands and contributed to the poor condition and subsequent mortal-
ity of cattle and to the ultimate collapse of the speculative, overstocked High Plains
cattle empire in the late nineteenth century (Stegner 1954 ) . The heavy mortality
of cattle during the drought and blizzards of 1886-1887, which extended into the
southern Great Plains (e.g., Wheeler 1991 ) , was made famous by Charley Russell's
Fig. 10.7
Tree-ring-reconstructed
summer PDSI averaged and
mapped for the 5-year period
from 1886 to 1890, and
indicating prolonged drought
over the northern Plains and
Pacific Northwest (see
Fig. 10.2 for mapping
details). The impacts of this
dry period were magnified by
the extreme blizzards of
1886, which resulted in the
'Great Die-Up' of range
cattle across the Great Plains
 
Search WWH ::




Custom Search