East Rongbuk ice cores (1998–2002)
Joint Chinese-American teams drilled ice cores on the col of the East Rongbuk Glacier at 6,500 meters on Everest's north side. The 2001 and 2002 drilling reached bedrock, yielding cores of 117, 108, and 95 meters. Analyses produced the first long records of Asian monsoon variability and pollutant deposition from the Everest region.
Papers in the mid-2000s mapped seasonal dust, trace metals, and snow chemistry on the north slope.
The East Rongbuk dataset became the benchmark Everest ice-core record for two decades and the comparison point for every later high-altitude drilling project.
Every prior Everest ice-core study came from this lower-elevation glacier. The 2026 summit cores test whether the chemistry seen at 6,500 meters holds at the actual peak.