Physical Sciences and Mathematics Commons^™

Methanesulfonate In The Firn Of King George Island, Antarctica, Jiankang Han, Zichu Xie, Xinping Zhang, Dongsheng Dai, Paul Andrew Mayewski, M. S. Twickler

Earth Science Faculty Scholarship

Methanesulfonate was investigated as a potential contributor to the sulfur budget, based on analysis of a firn core from Collins Ice Cap, King George Island, Antarctica (62°10' S, 58°50' W). The anion was found to be present at a mean concentration of 0.17 μeq L^-1, with a maximum of 0.73 μeq L^-1. Dating based on the δ¹⁸O profile suggests that the principal peaks of methanesulfonate are associated with snow deposited in summer and autumn. A careful examination of MSA, SO₄^2-and nssSO₄^2- profiles indicates that two of the three peaks …

High-Precision Dating Of Volcanic Events (A.D. 1301–1995) Using Ice Cores From Law Dome, Antarctica, Anne S. Palmer, Tas D. Van Ommen, Mark A. J. Curran, Vin Morgan, Joe M. Souney, Paul Andrew Mayewski

Earth Science Faculty Scholarship

A record of volcanic activity over the period A.D. 1301–1995 has been extracted from three Law Dome ice cores (East Antarctica). The record dating is unambiguous at the annual level from A.D. 1807 to 1995 and has an uncertainty of ±1 year at A.D. 1301. Signals from 20 eruptions are preserved in the record, including those of two unknown eruptions with acid deposition beginning in A.D. 1810.8 and A.D. 1685.8. The beginning of the ice core signal from the A.D. 1815 Tambora eruption is observed in the austral summer of A.D. 1816/1817. The mean observed stratospheric transport and deposition time …

The Origin Of A Polar Ice Sheet In East Antarctica, George H. Denton

University of Maine Office of Research Administration: Grant Reports

This award supports a study to determine the sequence and chronology of events that led to the development of the Antarctic ice sheet. A continental-scale ice sheet probably first developed in East Antarctica close to the Eocene-Oligocene boundary under temperate climatic conditions. The purpose of this project is to determine, from landscape analysis (with a numerical chronology), when (and why) these early temperate conditions gave way to a polar environment in Antarctica. From previous field work and recent photographic analysis, an extensive relict landscape (older than 17 million years) with landforms and erosional features characteristic of temperate glaciation has been …

Acquisition Of Ion Chromatographs And Related Glaciochemistry Equipment, Paul Andrew Mayewski

University of Maine Office of Research Administration: Grant Reports

The goal of this project has been to upgrade the ice core processing and analytical equipment. This has been accomplished in three major areas: the design and construction of an ice core lathe, develpoment of a continuous melting system, and new ion chromatographs. The lathe is a unique ice core processing tool that operates similiar to a wood lathe. The lathe will reduce or eliminate the need for the cores to be hand scraped, the first cleaning step of core preparation.

Our continuous melting system is a modification of existing designs. Unlike other systems, we will collect discrete samples for …

Collaborative Research: Paleoclimate And Glaciological Recontructions In Central Asia, Karl J. Kreutz

University of Maine Office of Research Administration: Grant Reports

This project resulted in the collection of two intermediate-length (165 m) ice cores from the Inilchek Glacier, Central Tien Shan Mountains, Kyrgyzstan, during July/August 2000 with colleagues from UCSB, UNH, and the USGS. In addition, precipitation, fresh snow, surface snow, and aerosol samples were collected on the glacier and in the Inilchek Valley to assess atmospheric chemistry and deposition processes. The overall goal of the project (including a pending NSF/DOE proposal) is to develop high-resolution paleoclimatic records covering the last 1000-2000 years, which will be calibrated with meteorological data from the robust station network in the former Soviet Central Asian …

A Theory Of Global Climate Change On Millennial Time Scales, Kirk A. Maasch

University of Maine Office of Research Administration: Grant Reports

A Theory of Global Climate Change on Millennial Time Scales In the northern hemisphere, large and rapid shifts in environmental conditions have occurred repeatedly over the last glacial- interglacial cycle. Indications are that climate change occurs on two characteristic time scales, roughly 1 - 3,000 years and 5 - 10,000 years. Evidence for millennial-scale climate variability has been found in ice cores drilled through the Greenland ice sheet, sediment cores from the North Atlantic Ocean, pollen records from both North America and Europe, and glacial deposits in North America. Paleoclimate records from the southern hemisphere also show climatic variability on …