Department of Earth Sciences
Newton Horace Winchell School of Earth Sciences


R. Lawrence Edwards

Office: 

208A Pillsbury Hall

Phone: 
612-626-0207
Email: 
edwar001
Info box extra information: 

Robert D. and Carol C. Gunn Professor and Distinguished McKnight University Professor
PhD, 1988, California Institute of Technology


Research Interests

Larry Edwards is an isotope geochemist well-known for his role in the development of modern uranium-thorium (or Th-230) dating methods and his application of these methods to the study of climate history and ocean chemistry. His approaches have improved the accuracy of radiocarbon dating, with the long-sought goal of a complete calibration of the radiocarbon timescale now in sight.

Edwards champions cave deposits as recorders of historic and pre-historic climate. Using innovative strategies, he relates his cave climate histories to those from ocean sediments and from ice cores, thereby establishing patterns of changing climate in time and space. His work helps us to understand the causes of abrupt climate change and the causes of the rapid melting of ice sheets at the end of glacial cycles.

Some of his research assesses the relationship between climate change and cultural history, drawing plausible links between global shifts in rainfall patterns and major cultural changes. For example, his cave records suggest that dry conditions contributed to the demise of the Tang, Yuan, and Ming Dynasties in China. His records also suggest that ample rainfall in the early decades of the Northern Song Dynasty contributed to the large expansion of rice cultivation and population increase in this era when rice became a staple of the Chinese diet.

His cave records of the last several centuries contain some of the strongest evidence yet for human-induced climate change. Edwards is one of the most cited earth scientists in the world.



Courses Taught

  • Earth and Its Environments
  • Geochemical Principles
  • Isotope Geology



Selected Publications

  • Badertscher, S., Fleitmann, D., Cheng, H., and Edwards, R.L., Göktürk, O.M., Zumbühl, A., Leuenberger, M. and Tüysüz, O. 2011. Pleistocene water intrusions from the Mediterranean and Caspian Seas into the Black Sea, Nature Geoscience 4, 236-239. doi: 10.1038/NGEO1106
  • Denton, G.H., Anderson, R.F., Toggweilor, J.R., Edwards, R.L., Schaeffer, J.M. and Putnam, A.E. 2010. The last glacial termination. Science 328, 1652-1656. DOI: 10.1126/science.1184119.
  • Cai, Y.J., Cheng, H., An, Z.S., Edwards, R.L., Wang, X.F., Tan, L.C., and Wang, J. 2010. Large variations of oxygen isotopes in precipitation over south-central Tibet during Marine Isotope Stage 5. Geology 38:3, 243-246. doi: 10.1130/G30306.1
  • Cheng, H., Edwards, R.L., Broecker, W.S., Denton, G.H., Kong, X.G., Wang, Y.J., Zhang, R., Wang, X.F., & Jiang, X.Y. 2009. Ice Age Terminations. Science 326, 248-252. doi: 10.1126/science.1177840.
  • Zhang, P.Z., Cheng, H., Edwards, R.L., Chen, F.H., Wang, Y.J., Yang, X.L., Liu, J., Tan, M., Wang, X.F., Liu, J.H., An, C.L., Dai, Z.B., Zhou, J., Zhang, D.Z., Jia, J.H., Jin, L., & Johnson, K.R. 2008. A high resolution test of sun, climate, culture relationships from a 1810-year Chinese cave record. Science 322, 940-942.
  • Wang, Y.J., Cheng, H., Edwards. R.L., Kong, X.G., Shao, X.H., Chen, S.T., Wu, J.Y., Jiang, X.Y., Wang, X.F. & An, Z.S. 2008. Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years. Nature 451, 1090-1093; doi:10.1038/nature06692
  • Cheng, H., Edwards, R.L., Wang, Y.J., Kong, X.G., Ming, Y.F., Kelly, M.J., Wang, X.F., Gallup, C.D., and Liu, W.G. 2006. A penultimate glacial monsoon record from Hulu Cave and two-phase glacial terminations. Geology 34, 217-220.
  • Wang, Y.J., Cheng, H., Edwards, R.L., He, Y.Q., Kong, X.G., An, Z.S., Wu, J.Y., Kelly, M.G., and Dykoski, C.A. 2005. The Holocene Asian Monsoon: links to solar changes and North Atlantic climate. Science 308, 854-857.
  • Wang, X.-F., Auler, A.S., Edwards, R.L., Cheng, H., Cristalli, P., Smart, P., & Richards, D. 2004. Wet periods in NE Brazil over the past 210 kyr linked to distant climate anomalies. Nature 432, 740-744.
  • Yuan, D.X., Cheng, H., Edwards, R.L., Dykoski, C., Kelly, M.J., Zhang, M.L., Qing, J.M., Lin, Y.S., Wang, Y.G., Dorale, J.A., An, Z.S. & Cai, Y.J. 2004. Timing, duration, and transitions of the Last Interglacial Asian Monsoon. Science 304, 575-578.
  • Cobb, K.M., Charles, C.D., Cheng, H., and Edwards, R.L. 2003. El Nino-Southern Oscillation and tropical Pacific climate during the last millennium. Nature 424, 271-276.
  • Wang, Y.G., Cheng, H., Edwards, R.L., An, Z.S., Wu, J.Y., Shen, C.-C. & Dorale, J.A. 2001. A high-resolution absolute-dated late Pleistocene monsoon record from Hulu Cave, China. Science 294, 2345-2348.
  • Cheng, H., Edwards, R.L., Hoff, J., Gallup, C.D., Richards, D.A., and Asmerom, Y. 2000. The half-lives of uranium-234 and thorium-230. Chemical Geology 169, 17-33.
  • Edwards, R.L., Chen, J.H. & Wasserburg, G.J. 1987. U-238, U-234, Th-230, Th-232 systematics and the precise measurement of time over the past 500,000 years. Earth Planet. Sci. Lett.81, 175-192

    *designates student author


Recent Honors and Awards

 

Citations