Several sites within the Transantarctic Mountains fit the requirements necessary for the retrieval of ice cores that can provide valuable information concerning climate change and atmospheric chemistry

Mayewski, Paul Andrew

English

University of Maine

The University of MaineDigitalCommons@UMaineEarth Science Faculty Scholarship Earth Sciences1987Transantarctic Mountains Ice Core StudyPaul Andrew MayewskiUniversity of Maine, paul.mayewski@maine.eduFollow this and additional works at: https://digitalcommons.library.umaine.edu/ers_facpubPart of the Climate Commons, Geochemistry Commons, Glaciology Commons, and theHydrology CommonsThis Article is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Earth Science FacultyScholarship by an authorized administrator of DigitalCommons@UMaine. For more information, please contactum.library.technical.services@maine.edu.Repository CitationMayewski, Paul Andrew, "Transantarctic Mountains Ice Core Study" (1987). Earth Science Faculty Scholarship. 229.https://digitalcommons.library.umaine.edu/ers_facpub/229Transantarctic Mountains ice corestudyPAUL A. MAYEWSKIGlacier Research GroupInstitute for the Study of Earth Oceans and SpaceUniversity of New HampshireDurham, New Hampshire 03824Several sites within the Transantarctic Mountains fit the re-quirements necessary for the retrieval of ice cores that canprovide valuable information concerning climate change andatmospheric chemistry. During the 1984-1985 austral summer,our group recovered, with the aid of the Polar Ice Coring Office,a 201-meter long core from a 2,800-meter high snow massif atopthe Dominion Range (85°15'S 166°10'E) close to the confluenceof the Mill and Beardmore glaciers. Chemical properties (sul-fate, nitrate, fluoride, chloride, phosphate, sodium, reactivesilicate, and total beta-activity) and physical properties (strat-igraphy, density, and solid conductivity) combined with oxy-gen-isotope analysis (provided by P. Grootes and M. Stuiver,University of Washington) are currently being completed onone 6-meter snowpit, several 2-meter snowpits, fresh and agedsurface snow, and the 201-meter core. Final results from thestudy await analysis of several more sections of core, but it isapparent that the study will provide valuable information forthe period 0-2,000 years ago in some cases with seasonal detail,concerning: volcanic activity, source and input timing for chem-ical species transported to the drill site, changes in atmosphericchemistry and mass balance, and ice mass stability for the area.The Dominion Range core will be supplemented by a coringprogram in southern Victoria Land to begin in austral summer1987-1988 in an attempt to provide a regional view of climatechange and atmospheric chemistry for the TransantarcticMountains.This work was supported by National Science Foundationgrants DPP 84-11108 and DPP 85-13699.Ice-core drilling for paleoclimaticinformation at plateau remoteELLEN MOSLEY-TFIOMPSON, JOHN F PASKIEVITCH,and STEVEN M. GROSSByrd Polar Research CenterOhio State UniversityColumbus, Ohio 43210An ice-core drilling program was conducted during De-cember 1986 and January 1987 at a remote site (84°S 43°E, 3,330meters above sea level) near the Pole of Relative Inaccessibilityon the east antarctic plateau. The central research objective ofthis program is to acquire information about atmospheric con-centrations of insoluble and soluble particulates, atmospherictemperature, and net mass accumulation during the last two orthree millennia. The plateau remote program complements pro-grams previously conducted at South Pole Station (Mosley-Thompson et al. 1985), Siple Station (Mosley-Thompson,Mountain, and Paskievitch 1986; Mosley-Thompson in prepara-tion), and on the Quelccaya ice cap in the Peruvian Andes(Thompson, Mosley-Thompson, and Arnao 1984; Thompson etal. 1985, 1986).The drilling was performed by the Polar Ice Coring Office(Kuivinen and Koci, Antarctic Journal, this issue). Two deepcores (205 meters and 202 meters) and 13 shallow cores ofdepths varying between 8 and 22 meters were recovered.Weather conditions were generally clear with a persistent windof 5 meters per second from the quadrant between 320° and 10°(with reference to true north). Temperatures ranged from a highof -26'C toward the end of the season and near the warmestpart of the day to a low near - 40°C. Sastrugi as high as 0.4 to 0.5meters were observed to be oriented in two prominent direc-tions. The long axis of the first set of sastrugi was nearly parallelto the observed surface wind (approximately 0° or true north).This is also approximately parallel to the surface contours (ex-tracted from Drewry 1983). The second set of sastrugi wasoriented 30°-40° from true north suggesting formation by windobliquely crossing the elevation contours. This may reflect theprevailing winter surface wind regime which exhibits high con-stancy due to the thermal wind effect. The latter effect resultswhen an extensive atmospheric inversion layer lies over a gentlysloped surface (Schwerdtfeger and Mahrt 1968).Multiple vertical sequences of samples were collected fromthe walls of two pits and will be analyzed for insoluble micro-particle concentrations and size distributions, liquid con-ductivity, anion concentrations, oxygen-isotope ratios, and totalBeta radioactivity. Density profiles were measured in each pit. Apreliminary estimate of net annual accumulation based solelyupon visible stratigraphy suggests 40 to 70 millimeters of iceequivalent per year and a high degree of variability from year toyear. The visible stratigraphy was mapped and a video camerawas used to produce a permanent record for more detailedstudy. Shallow cores (8 to 20 meters in depth) were collectedbehind the sampled pit walls for comparison with pit samples.Ten of the shallow cores were collected prior to pit excavationand the pit sampling was conducted immediately upon excava-tion to minimize contamination. The stratigraphic mapping andphotography were performed last.The analyses of the 13 shallow cores, in conjunction withsamples collected from two pits, will allow assessment of thespatial variability present in the particulate concentrations, liq-uid conductivities, oxygen-isotope ratios, and net mass ac-cumulation records. This assessment is necessary to determinethe limit to which annual information can be extracted from thetwo deeper cores. The characteristics of the annual signal (ifpresent) in each of the preserved ice core parameters must bedetermined and any interrelationships understood. The modi-fication of the annual signal by depositional and post-deposi-78	 ANTARCTIC JOURNAL

Transantarctic Mountains Ice Core Study

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Transantarctic Mountains Ice Core Study

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