How long is the core that they took? What exactly is "Full Depth" in meters?
The core is approximately 9.5 meters long — that is the full ice thickness at Everest's summit measured by the 2022 radar survey that planned this drill.
Why it matters: Nine-and-a-half meters sounds modest, but it is the entire ice column: drilling 'full depth' means reaching bedrock, not a partial sample, which is what makes this archive complete.
- A May 2022 ground-penetrating radar survey by Xu Baiqing's team found mean ice/snow depth at the Everest summit to be 9.5 ± 1.2 meters — far deeper than the 0.9–3.5 m estimates from the previous five decades.
- That 2022 radar work was explicitly designed to set drilling targets for this expedition, so the 2026 core should match that ~9.5 m full-thickness figure.
- 'Full depth' means the drill went from the surface all the way to bedrock, capturing the entire summit ice column rather than stopping at a set length — a distinction that matters for completeness of the climate record.
- For comparison, the previous Everest-region record cores from the East Rongbuk Glacier (6,518 m) reached up to 108 meters — longer because valley glaciers are far thicker than summit ice caps.
- The 9.5 m figure is the radar-measured ice thickness, not a confirmed published length for the 2026 core itself — Chinese state media and wire reports describe it as 'full depth' without stating a meter figure, so the exact core length awaits the scientific paper.
