Coffee Hour: Foot Steps of the Ancient Great Glacier of North America: A Long Lost Document of a Revolution in Nineteenth Century Geological Theory

Friday, March 18, 2016 - 3:30pm
Refreshments are offered in 319 Walker Building at 3:30 p.m. The lecture begins in 112 Walker Building at 4:00 p.m.

Foot Steps manuscriptand book covers


About the talk

John K. DeLaski practiced medicine in the Penobscot Bay region of Maine in the middle of the 19th century. He was also a naturalist with keen powers of observation. His study of the landscape led to the conclusion that a thick glacier had overtopped the highest hills, flooded all of Penobscot Bay, extended far to the east and west and probably was part of a greater continental glacier. He published his field observations and inferences in numerous articles in local newspapers and magazines, and in the American Journal of Science in 1864. His work put him on the “team” of Benjamin Silliman, James D. Dana and Louis Agassiz as an advocate for glaciation as the regional land shaping force opposed to that of the biblical deluge, a major scientific conflict of the day both in North America and Europe. He remained a shadowy player, in the background, but clearly contributed significant observations to the argument through personal interactions with Agassiz and other prominent naturalists. John DeLaski’s summary work, a 400-page handwritten manuscript for the book, “The Ancient Great Glacier of North America”, was dated 1869. If it had been published in his day, it would have been the first book on this continent, at least, to present a holistic discussion of the controversy in which he laid out his critical observations of the surficial geology of Maine, southern New England and New Brunswick concluding that the depositional and erosional features must be of glacial origin.

About the speaker

Kirk MaaschKirk Allen Maasch is a professor of Atmospheric Science in the Climate Change Institute and the School of Earth and Climate Sciences at The University of Maine. He earned a B.S. in geology from SUNY Stony Brook (1981), and a M.Phil. (1984) and Ph.D. (1989) in atmospheric science from Yale University. He has over 30 years of experience using climate models and statistical methods to investigate the causes of climate change across time scales ranging from years to millions of years. The models range in complexity from simple low-order dynamical systems to complex three-dimensional models of the atmosphere. Maasch has worked toward developing a theory for long-time scale climate change (ice ages and millennial scales) using low-order dynamical systems models guided by the most detailed available paleoclimate proxy records. For higher frequency climate variability (interannual to decadal) ice core chemistry is used to reconstruct sub-annually resolved records of changes in atmospheric circulation over the past several thousand years. These ice core derived proxy records are calibrated with the instrument record, primarily reanalysis data, in order to interpret how the changes in chemistry relate to climate change. He has looked at interannual to decadal scale climate variability in the Holocene focusing on how past changes in the frequency of El Niño have impacted human activities. He remains interested in the history of scientific progress toward understanding climate change as well as using historic accounts of weather to extend the quantitative record of climate change. Maasch is also actively involved in modeling present-day and future regional scale climate change using general circulation models of the atmosphere along with nested high-resolution models.

Suggested reading

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Coffee Hour