Michaele Kashgarian
R. Rye
S. Lund
F. Paillet
J. Smoot
C. Kester
S. Mensing
D. Meko
S. Lindstrom
L. Benson
2002
<p><span>Continuous, high-resolution </span><i>δ</i><sup>18</sup><span>O records from cored sediments of Pyramid Lake, Nevada, indicate that oscillations in the hydrologic balance occurred, on average, about every 150</span><span> </span><span>years (yr) during the past 7630 calendar years (cal</span><span> </span><span>yr). The records are not stationary; during the past 2740</span><span> </span><span>yr, drought durations ranged from 20 to 100</span><span> </span><span>yr and intervals between droughts ranged from 80 to 230</span><span> </span><span>yr. Comparison of tree-ring-based reconstructions of climate change for the past 1200</span><span> </span><span>yr from the Sierra Nevada and the El Malpais region of northwest New Mexico indicates that severe droughts associated with Anasazi withdrawal from Chaco Canyon at 820</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP (calendar years before present) and final abandonment of Chaco Canyon, Mesa Verde, and the Kayenta area at 650</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP may have impacted much of the western United States.During the middle Holocene (informally defined in this paper as extending from 8000 to 3000</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP), magnetic susceptibility values of sediments deposited in Pyramid Lake's deep basin were much larger than late–Holocene (3000–0</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP) values, indicating the presence of a shallow lake. In addition, the mean </span><i>δ</i><sup>18</sup><span>O value of CaCO</span><sub>3</sub><span> precipitated between 6500 and 3430</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP was 1.6‰ less than the mean value of CaCO</span><sub>3</sub><span> precipitated after 2740</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP. Numerical calculations indicate that the shift in the </span><i>δ</i><sup>18</sup><span>O baseline probably resulted from a transition to a wetter (>30%) and cooler (3–5°C) climate. The existence of a relatively dry and warm middle-Holocene climate in the Truckee River–Pyramid Lake system is generally consistent with archeological, sedimentological, chemical, physical, and biological records from various sites within the Great Basin of the western United States. Two high-resolution Holocene-climate records are now available from the Pyramid and Owens lake basins which suggest that the Holocene was characterized by five climatic intervals. TIC and </span><i>δ</i><sup>18</sup><span>O records from Owens Lake indicate that the first interval in the early Holocene (11,600–10,000</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP) was characterized by a drying trend that was interrupted by a brief (200</span><span> </span><span>yr) wet oscillation centered at 10,300</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP. This was followed by a second early-Holocene interval (10,000–8000</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP) during which relatively wet conditions prevailed. During the early part of the middle Holocene (8000–6500</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP), high-amplitude oscillations in TIC in Owens Lake and </span><i>δ</i><sup>18</sup><span>O in Pyramid Lake indicate the presence of shallow lakes in both basins. During the latter part of the middle Holocene (6500–3800</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP), drought conditions dominated, Owens Lake desiccated, and Lake Tahoe ceased spilling to the Truckee River, causing Pyramid Lake to decline. At the beginning of the late Holocene (∼3000</span><span> </span><span>cal</span><span> </span><span>yr</span><span> </span><span>BP), Lake Tahoe rose to its sill level and Pyramid Lake increased in volume.</span></p>
application/pdf
10.1016/S0277-3791(01)00048-8
en
Elsevier
Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada
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