Climate from Speleothems: Devil’s Hole Record Compared With Milankovitch Hypothesis

Carson Rittel

The Devils Hole calcite vein provides a high-resolution paleoclimate record for 500ka. The climate data is derived from the delta 18 O record of the core. The data has presents four challenges to the well-accepted Milankovitch hypothesis.

The Milankovitch hypothesis states that ice ages have been driven by periodic cycles of eccentricity, obliquity, and precession of Earth’s orbit.

The Devils hole record presents the following challenges:

(See Fig 1)

•Interglacial maximum at 140ka B.P. SPECMAP maximum at 128 ka B.P.

•Increase in glacial cycles from 80ka to 130ka long.

•Interglacial climate warmer from 410-120ka. This is not seen on SPECMAP

•Glacial/Interglacial at 450-350ka when isolation says none should occur (See Fig 2&3)

Devils Hole / SPECMAP

Fig 1. (Bradley 1999) Devils Hole record compared with the SPECMAP marine isotope record.

Fig 2. Note the difference between the d18O and the ETP curve at 400ka.

Source: http://www.lancs.ac.uk/staff/telfordr/lectures/352holocene/specmap.html

Orbital inclination / SPECMAP

Fig 3. (Muller 2001) Comparison of orbital inclination and climate data from SPECMAP. Orbital inclination provides a solution to the glacial/interglacial between 350-450ka.

SEMINAR OUTLINE:

I. Introduction

II. Background info on Speleothems

III. Devils Hole Record

a. Milankovitch Hypothesis

b. Devils Hole Challenges

c. Support for Milankovitch

IV. Closing

References:

Journals:

Monastersky, Richard, (1992). Devils Hole Heats Up Debate Over Ice Ages, Science News, vol. 142, p. 228.

Winograd, I.J., Coplen, T.B., Landwehr, J.M., Riggs, A.C., Ludwig, K.R., Szabo, Kolesar, P.T., and Reversz, K.M., (1992). Continuous 500,000 climate record from vein calcite in Devils Hole, Nevada, Science, vol. 258, p. 255.

(1992). Devils Hole discovery hots up row over ice ages, New Scientist, vol. 136, p. 15.

(1993). Devilish ice-age record, Science News, vol. 144, p. 44.

Webpages:

Landwehr, J.M., Winograd, I.J., (2/22/2001). A Devils Hole Primer, http://water.usgs.gov/nrp/devils.html

Muller, Richard A., MacDonald, Gordon J., (3/25/01). Origin of the 100kyr Glacial Cycle: eccentricity or orbital inclination?, http://muller.lbl.gov/papers/nature.html

Books:

Bradley, Raymond S., (1999). Paleoclimatology – Reconstructing Climates of the Quaternary, Harcourt Academic Press, p. 333.