An Ice Core Snapshot of Past Atmospheric Chemistry in Mt. Everest’s 'Death Zone'

Mariusz Potocki, Paul Andrew Mayewski

We present a unique atmospheric chemistry record from the highest ice core ever recovered (8020 m, South Col Glacier (SCG), Mt. Everest), that captures ~400 years of deposition during the latter half of the first millennium BCE. Due to recent glacier thinning, the upper ~2000 years of accumulation have been lost, however, this is the only ice core record ever recovered from the “Death Zone (>8000 m)” and likely the only record that can be attained. Insights from this 10m deep record and comparison with an ice core we recovered on the north side of Mt. Everet include: an estimated lapse rate of water isotopes at extreme elevations; the influence of southerly and northerly source air masses on precipitation, dusts and overall atmospheric chemistry over Mt. Everest; and possibly the earliest influences of human activity on the chemistry of the atmosphere in this region.