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Full-Text Articles in Physical Sciences and Mathematics
Methanesulfonate In The Firn Of King George Island, Antarctica, Jiankang Han, Zichu Xie, Xinping Zhang, Dongsheng Dai, Paul Andrew Mayewski, M. S. Twickler
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, SO42-and nssSO42- 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
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 …
New Data On Welshite, E.G. Ca2mg3.8mn0.62+Fe0.12+Sb1.55+O2 [Si2.8be1.7fe0.653+Al0.7as0.17o18], An Aenigmatite-Group Mineral, Edward S. Grew, U. Hålenius, M. Kritikos, C. K. Shearer
New Data On Welshite, E.G. Ca2mg3.8mn0.62+Fe0.12+Sb1.55+O2 [Si2.8be1.7fe0.653+Al0.7as0.17o18], An Aenigmatite-Group Mineral, Edward S. Grew, U. Hålenius, M. Kritikos, C. K. Shearer
Earth Science Faculty Scholarship
Electron and ion microprobe data on two samples of welshite from the type locality of Langban, Sweden, gave analytical totals of 99.38-99.57 wt.% and BeO contents of 4.82-5.11 wt.%, corresponding to 1.692-1.773 Be/20 O. Mossbauer and optical spectra of one of these samples gave Fe-[iv](3+)/Sigma Fe = 0.91, Fe-[iv](2+)/Sigma Fe = 0.09, and no evidence of Mn3+. The resulting formula for this sample is Ca2Mg3.8Mn0.62+Fe0.12+Sb1.55+O2[Si2.8Be1.7Fe0.653+Al0.7As0.17O18], and that for the second sample, Ca2Mg3.8Mn0.12+Fe0.12+F0.83+Sb1.25+O2[Si2.8Be1.8F0.653+Al0.25As0.25O18], is related by the substitution involving tetrahedral and octahedral sites: 0.59([vi,iv])(Fe,Al)(3+) approximate to 0.42([vi])(Mg,Mn,Fe)(2+) + 0.21(Sb-[vi],As-[iv])(5+), i.e. 3([vi,iv]) M3+ = 2([vi])M(2+) + M-[vi,iv](5+). WelShite is distinctive among aenigmatite-group …
Comment On "On Sharp Spectral Lines In The Climate Record And The Millennial Peak" By Carl Wunsch, L. D. Meeker, Paul Andrew Mayewski, Pieter M. Grootes, Richard B. Alley, Gerard C. Bond
Comment On "On Sharp Spectral Lines In The Climate Record And The Millennial Peak" By Carl Wunsch, L. D. Meeker, Paul Andrew Mayewski, Pieter M. Grootes, Richard B. Alley, Gerard C. Bond
Earth Science Faculty Scholarship
No abstract provided.
Glacial Lake Wright, A High-Level Antarctic Lake During The Lgm And Early Holocene, Brenda L. Hall, George H. Denton, B. Overturf
Glacial Lake Wright, A High-Level Antarctic Lake During The Lgm And Early Holocene, Brenda L. Hall, George H. Denton, B. Overturf
Earth Science Faculty Scholarship
We report evidence of a large proglacial lake (Glacial Lake Wright) that existed in Wright Valley in the McMurdo Dry Valleys region of Antarctica at the last glacial maximum (LGM) and in the early Holocene. At its highstands, Glacial Lake Wright would have stretched 50 km and covered c. 210 km(2). Chronology for lake-level changes comes from 30 AMS radiocarbon dates of lacustrine algae preserved in deltas, shorelines, and glaciolacustrine deposits that extend up to 480 m above present-day lakes. Emerging evidence suggests that Glacial Lake Wright was only one of a series of large lakes to occupy the McMurdo …
Long-Term And Seasonal Variations In Co2: Linkages To Catchment Alkalinity Generation, Stephen A. Norton, B. J. Cosby, I. J. Fernandez, J. S. Kahl, M. Robbins Church
Long-Term And Seasonal Variations In Co2: Linkages To Catchment Alkalinity Generation, Stephen A. Norton, B. J. Cosby, I. J. Fernandez, J. S. Kahl, M. Robbins Church
Earth Science Faculty Scholarship
As atmospheric emissions of S have declined in the Northern Hemisphere, there has been an expectation of increased pH and alkalinity in streams believed to have been acidified by excess S and N. Many streams and lakes have not recovered. Evidence from East Bear Brook in Maine, USA and modelling with the groundwater acid-base model MAGIC (Cosby et al. 1985a,b) indicate that seasonal and yearly variations in soil PCO2 are adequate to enhance or even reverse acid-base (alkalinity) changes anticipated from modest decreases of SO4 in surface waters. Alkalinity is generated in the soil by exchange of H+ from dissociation …
A High-Altitude Snow Chemistry Record From Amundsenisen, Dronning Maud Land, Antarctica, E. Isaksson, W. Karlen, Paul Andrew Mayewski, M. Twickler, S. Whitlow
A High-Altitude Snow Chemistry Record From Amundsenisen, Dronning Maud Land, Antarctica, E. Isaksson, W. Karlen, Paul Andrew Mayewski, M. Twickler, S. Whitlow
Earth Science Faculty Scholarship
In this paper a detailed record of major ions from a 20 in deep firn core from Amundsenisen, western Dronning Maud Land, Antarctica, is presented. The core was drilled at 75degreesS, 2degrees E (2900 m.a.s.l.) during austral summer 1991/92. The following ions were measured at 3 cm resolution: Na+, Mg2+, Ca2+, Cl-, NO3-, SO42- and CH3SO3H (MSA). The core was dated back to 1865 using a combination of chemical records and volcanic reference horizons. The volcanic eruptions identified in this core are Mount Ngauruhoe, New Zealand (1974-75), Mount Agung, Indonesia (1963), Azul, Argentina (1932). and a broad peak that corresponds …
Oxygen Isotopic And Soluble Ionic Composition Of A Shallow Firn Core, Inilchek Glacier, Central Tien Shan, Karl J. Kreutz, Vladimir B. Aizen, L. Dewayne Cecil, Cameron P. Wake
Oxygen Isotopic And Soluble Ionic Composition Of A Shallow Firn Core, Inilchek Glacier, Central Tien Shan, Karl J. Kreutz, Vladimir B. Aizen, L. Dewayne Cecil, Cameron P. Wake
Earth Science Faculty Scholarship
Oxygen isotopic and soluble ionic measurements made on snow-pit (2 in depth) and firn-core (12.4 m depth samples recovered from the accumulation zone 5100 m) of Inilchek glacier 43degrees N, 79degrees E) provide information on recent (1992-98) climatic and environmental conditions in the central Tien Shan region of central Asia. The combined 14.4 m snow-pit/firn-core profile lies within the firn zone, arid contains only one observed melt feature (10 m temperature = - 12 degreesC), Although some post-depositional attenuation of the sub-seasonal delta(18)O record is possible, annual cycles are apparent throughout the isotope profile. We therefore use the preserved delta(18)O …
Evidence Of The Kuwaiti Oil Fires In The Dasuopu Glacier Ice Core, Central Himalaya, Shichang Kang, Qin Dahe, Paul Andrew Mayewski, Xie Shucheng, Duan Keqin
Evidence Of The Kuwaiti Oil Fires In The Dasuopu Glacier Ice Core, Central Himalaya, Shichang Kang, Qin Dahe, Paul Andrew Mayewski, Xie Shucheng, Duan Keqin
Earth Science Faculty Scholarship
No abstract provided.
Recent 180 Year Oxalate (C2o42-) Records Recovered From The Mount Everest Ice Core: Some Environmental Implications, Shichang Kang, Qin Dahe, Paul Andrew Mayewski, Cameron P. Wake
Recent 180 Year Oxalate (C2o42-) Records Recovered From The Mount Everest Ice Core: Some Environmental Implications, Shichang Kang, Qin Dahe, Paul Andrew Mayewski, Cameron P. Wake
Earth Science Faculty Scholarship
No abstract provided.