A 160 m firn and ice core was recovered from Eclipse Icefield (60.510 N, 139.470 W, 3017 m elevation) in the summer of 1996. Visible stratigraphy (location and thickness of ice layers) and density measurements were made in the field, and then the core was shipped frozen to the University of New Hampshire.

A 160 m ice core was recovered in June 1996 from Eclipse Icefield (60.51 degrees N, 139.47 degrees W, 3017 m elevation). Visible stratigraphy (location and thickness of ice layers) and density measurements were made in the field, and then the core was shipped frozen to the University of New Hampshire. The core was continuously sampled in 10 cm segments, corresponding to a minimum of 12 samples per year. Above the firn-ice transition which occurs at 45 m depth, core was scraped on an acrylic lathe system under a laminar flow bench using a titanium scraper so that all surface and sub-surface contamination from the drilling process was removed. Below the firn-ice transition, samples were cut into 3 x 3 cm pieces 10 cm long and the middle of the samples melted out using a custom made melter also used to sample the GISP2 ice core. Samples were analyzed for major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-) using a Dionex model 2010 ion chromatograph in a dedicated laboratory at the University of New Hampshire. The cation system used a CS12A column with CSRS-ultra suppressor in auto suppression recycle mode with 20 mM MSA eluent. The anion system used an AS11 column with an ASRS-ultra suppressor in auto suppression recycle mode with 6 mM NaOH eluent. Analytical precision was monitored by analyzing 10% of the samples in duplicate and found to be 11% for K+, 10% for NH4+, 7% for Na+, and less than 5% for all other species. Aliquots of the same samples were also analyzed for oxygen isotopes (delta 18O) at the Stable Isotope Laboratory in Copenhagen, Denmark (precision ± 0.05‰). Chronology of the Eclipse ice core is based on multi-parameter annual layer counting of seasonal oscillations in the stable isotope and major ion records (especially Na+ and NH4+). Age control on the chronology established via annual layer counting is provided by the 1963 and 1961 beta activity reference horizons and volcanic reference horizons identified by statistical analysis of the sulfate record and verified by tephrochronology. The resulting time scale indicates that the Eclipse 1996 ice core covers the period 1894 to 1996, with dating error in the core estimated to be +1 year based on the number of independently dated horizons. The chemical data presented here are at sub-annual resolution, and annually averaged. Data for the years 1894, 1995, and 1996 are incomplete and not included in the annual averages.

A 160 m ice core (Core 1) was recovered from Eclipse Icefield, St. Elias Mountains, Yukon, Canada, (60.51°N, 139.47°W, 3017 m elevation) in 1996. Two additional cores, 345m (Core 2) and 130m (Core 3) in length, were recovered in 2002.

Two Icecores (345 m and 130 m) were recovered in 2002, 100 m up the flow line from the 1996 drill site. All two cores were sampled continuously at high resolution for major ions and stable isotopes to establish a detailed chronology for the core. Sample resolution ranged from 6 to 15 cm for major ions and 2 to 15 cm for stable isotopes. Stringent core processing techniques were used to ensure samples were contamination-free at the ng/g level.

Icecore 345 m was recovered in 2002, core was sampled continuously at high resolution for major ions and stable isotopes to establish a detailed chronology for the core. Sample resolution ranged from 6 to 15 cm for major ions and 2 to 15 cm for stable isotopes. Stringent core processing techniques were used to ensure samples were contamination-free at the ng/g level.

In 1997, three ice cores were recovered from the Dasuopu glacier (28°23'N, 85°43'E) with the use of an electromechanical drill in dry holes. The first core (C1) was 159.9 m long and was drilled at 7000 m above sea level (a.s.l.) down the flow line from the top of the col, and two cores (C2 and C3), 149.2 and 167.7 m long, respectively, were drilled to bedrock 100 m apart on the col at 7200 m a.s.l. Visible stratigraphy showed no hiatus features in any of the cores. All cores were analyzed over their entire lengths for oxygen isotopic ratio (?18O ), chemical composition, and dust concentration.

Icecore of 130 m was recovered in 2002, 100 m up the flow line from the 1996 drill site. The core was sampled continuously at high resolution for major ions and stable isotopes to establish a detailed chronology for the core. Sample resolution ranged from 6 to 15 cm for major ions and 2 to 15 cm for stable isotopes. Stringent core processing techniques were used to ensure samples were contamination-free at the ng/g level.