U.S. GEOLOGICAL SURVEY

What is Devils Hole?
Devils Hole is a tectonic cave developed in the discharge zone of a regional aquifer in south-central Nevada. The walls of this predominantly subaqueous cavern are coated with dense vein calcite. The stable isotopic content of the calcite provides a 500,000-year record of variations in temperature and other paleoclimatic parameters.
(See Winograd, et al., 1992; and Riggs, et al., 1994.)

What do the stable isotopic records represent?
The Devils Hole d¹⁸O record is an indicator of paleotemperature and corresponds in timing and magnitude to paleo-SST (sea surface temperature) recorded in Pacific Ocean sediments off the California and Oregon coasts. The record is also highly correlated with major variations in temperature in the Vostok ice core, from the East Antarctic plateau. The d¹³C record is thought to reflect changes in global variations in the ratio of stable carbon isotopes of atmospheric CO₂ and/or changes in the density of vegetation in the groundwater recharge areas tributary to Devils Hole.
(See Winograd et al., 1996; Herbert et al., 2001; Winograd, 2002; Winograd, et al., 1997; Landwehr and Winograd, 2001; Landwehr, 2002; and Coplen, et al., 1994.)

Are the Devils Hole ages accurate? How was the vein calcite dated?
As eminent a geochemist as W. Broecker has stated that "...the Devils Hole chronology is the best we have..." Since 1992, all core material has been uranium-series dated using thermal ionization mass spectrometric (TIMS) methodology. In 1997, the Devils Hole Thorium-230 dates were independently confirmed by non-USGS investigators using Protactinium-231.
(See Broecker, 1992; Ludwig, et al., 1992; Winograd, et al., 1997; and Edwards, et al., 1997.)

Is there still an inconsistency between the Devils Hole record and the Milankovitch hypothesis?
Yes. The Milankovitch hypothesis holds that the timing and duration of the Pleistocene ice ages are a direct consequence of variations in solar insolation occurring at the latitude of 65° North, in response to changes in the precession, obliquity and eccentricity of the Earth's orbit. The 500,000-year Devils Hole d¹⁸O record presents four challenges to this theory with respect to:

1. the timing of the penultimate glacial-interglacial transition;
2. the duration of the interglacial climates ;
3. the apparent non-stationarity of paleoclimatic time series; and
4. the occurrence of a well-developed glacial-interglacial cycle at a time (450,000-350,000 years ago) when orbital theory indicates that none should occur.

Numerous discussions of the implications of the Devils Hole record to the Milankovitch hypothesis have been published since 1992, most addressing the first challenge listed above. However, uranium-series dating of corals that mark past sea level high stands has shown that the penultimate glacial-interglacial transition occurred by about 136,000 years ago, a finding irreconcilable with the Milankovitch hypothesis, even as modified by Crowley and Kim (1994). The three remaining challenges listed above have yet to receive detailed attention. A recent overview of this controversy appeared in the June 23, 2000 issue of Science.
(See Winograd, et al., 1992; Crowley and Kim, 1994; Winograd, et al., 1996; Winograd, et al., 1997; Henderson and Slowey, 2000; Gallup et al., 2002; Muhs et al., 2002; and Karner and Muller, 2000.)

How long can we expect the present interglaciation to last?
No one knows for sure. In the Devils Hole record, the last four interglaciations lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 -years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stand, and would suggest that an equally long duration should be inferred for the current interglacial period as well. Work in progress on Devils Hole data for the period 60,000 to 5,000 years ago indicates that current interglacial temperature conditions may have already persisted for 17,000 years. Other workers have suggested that the current interglaciation might last tens of thousands of years.
(See Winograd, et al., 1997; Muhs et al., 2002; and Paillard, 2001.)

Why should anyone but a scientist care about this topic?
In addition to providing information about the possible duration of our present interglacial climate (discussed above), research in Devils Hole has provided valuable information for water managers about recharge rates in the principal aquifer in south-central Nevada. Precise information about paleoclimates also provides information needed for evaluation of the potential suitability of Yucca Mountain, Nevada, for the disposal of nuclear wastes.
(See Szabo, et al., 1994; Forester et al., 1999; and Thomas, Winograd and Coplen, 1996.)

Where can I see the records?
Records for the period ~560 to 60 ka are given in USGS Open-file report 97-792, "Data from Devils Hole Core DH-11".
(See Landwehr, et al., 1997.)

References:

Broecker, W.S., 1992, Upset for Milankovitch theory: Nature, v. 359, p.779-780.

Coplen, T.B., Winograd, I.J., Landwehr, J.M., and Riggs, A.C., 1994, 500,000-year stable carbon isotopic record from Devils Hole, Nevada: Science, v. 263, p. 361-365.

Crowley, T.J., and Kim, K-Y, 1994, Milankovitch forcing of the last interglacial sea level: Science, v. 265, p. 1566-1568.

Edwards, R.L., Cheng, H., Murrell, M.T., and Goldstein, S.J., 1997, Protactinium-231 dating of carbonates by thermal ionization mass spectrometry: Implications for Quaternary climate change: Science, v. 276, p. 782-786.

Forester, R.M. et al., 1999, The climatic and hydrologic history of southern Nevada during the late Quaternary: U. S. Geological Survey, Open-File Report 98-635, 63 p.

Gallup, C.D., Cheng, H., Taylor, F.W., and Edwards, R.L., 2002, Direct determination of the timing of sea level change during termination II: Science, v. 295, p. 310-313.

Henderson, G.M. and Slowey, N.C., 2000, Evidence from U-Th dating against Northern Hemisphere forcing of the penultimate deglaciation: Nature, v. 404, p. 61-66.

Herbert, T.D., Schuffert, J.D., Andreasen, D., Heusser, L., Lyle, M., Mix, A., Ravelo, A.C., Stott, L.D., and Herguera, J.C., 2001, Collapse of the California Current during glacial maxima linked to climate change on land: Science, v. 293, p. 71-76.

Karner, D.B. and Muller, R.A., 2000, A causality problem for Milankovitch: Science, v. 288, p. 2143-2144.

Landwehr, J. M., 2002, Ice core depth-age relation for Vostok dD and Dome Fuji d¹⁸O records based on the Devils Hole paleotemperature chronology: U.S. Geological Survey Open-File Report 02-266, 53 p.

Landwehr, J.M., Coplen, T.B., Ludwig, K., Winograd, I.J., and Riggs, A. 1997, "Data from Devils Hole Core DH-11": U. S. Geological Survey Open File Report 97-792, 8 p.

Landwehr, J.M. and Winograd, I.J., 2001, Dating the Vostok ice core record by importing the Devils Hole Chronology: Journal of Geophysical Research - Atmospheres, v. D106, p. 31853-31862.

Ludwig, K.R., Simmons, K.R., Szabo, B.J., Winograd, I.J., Landwehr, J.M., Riggs, A.C., and Hoffman, R.J., 1992, Mass-spectrometric 230Th-234U-238U dating of the Devils Hole calcite vein: Science, v. 258, p. 284-287.

Muhs, D.R., Simmons, K.R., and Steinke, B., 2002, Timing and warmth of the last interglacial period: New U-series evidence from Hawaii and Bermuda and a new fossil compilation for North America: Quaternary Science Reviews, v. 21, p. 1355-1383.

Paillard, D., 2001, Glacial cycles: Toward a new paradigm: Reviews of Geophysics, v. 39, p. 325-346.

Riggs, A.C., Carr, W.J., Kolesar, P.T., and Hoffman, R.H., 1994, Tectonic speleogenesis of Devils Hole, Nevada, and implications for hydrogeology and the development of long, continuous paleoenvironmental records: Quaternary Research, v. 42, p. 241-254.

Szabo, B.J., Kolesar, P.T., Riggs, A.C., Winograd, I.J., and Ludwig, K.R., 1994, Paleoclimatic inferences from a 120,000-year calcite record of water-table fluctuations in Browns Room of Devils Hole, Nevada: Quaternary Research, v. 41, p. 59-69.

Thomas, J.M., Winograd, I.J. and Coplen, T.B., 1996, Carbon-14 dating of groundwater in southern Nevada: Three decades of surprises: Geological Society of America, Abstracts with Programs, v. 28, no. 7, p. A-197.

Winograd, I. J., 2002, The California Current, Devils Hole, and Pleistocene climate: Science, v. 296, p. 7

Winograd, I.J., Coplen T.B., Landwehr, J.M., Riggs, A.C., Ludwig,K.R., Szabo, B.J., Kolesar, P.T., and Revesz, K.M., 1992, Continuous 500,000-year climate record from vein calcite in Devils Hole, Nevada: Science, v. 258, p. 255-260.

Winograd, I.J., Coplen, T.B., Ludwig, K.R., Landwehr, J.M., and Riggs, A.C., 1996, High resolution delta-18O record from Devils Hole, Nevada, for the period 80 to 19 ka: EOS, v. 77, no. 17, p. S169.

Winograd, I.J., Landwehr, J.M., Ludwig, K.R., Coplen, T.B., and Riggs, A.C, 1997, Duration and structure of the past four interglaciations: Quaternary Research, v. 48, p. 141-154.

FOR ADDITIONAL INFORMATION,
see description of NRP project Interface of Paleoclimatology and Aquifer Geochemistry
Isaac J. Winograd, USGS, 432 National Center, Reston, VA 20192 USA. ijwinogr@usgs.gov
or contact
Jurate M. Landwehr, USGS, 431 National Center, Reston, VA 20192 USA jmlandwe@usgs.gov