Carbon dating evidence from the elevation of abandoned penguin rookeries (and other proxies) reveals that relative sea level (RSL) was ~30 meters higher than today across East Antarctica about 8,000 years ago (Small et al., 2025). [some emphasis, links added]
Following that highstand, RSL fell rapidly at rates of 4 to 10 meters per 1,000 years.
RSL was 24 meters above present sea level (ASL) by 7,200 years ago, 15 meters ASL by 5,700 years ago, 5 meters ASL by 3,200 years ago, and still 1 meter ASL about 800 years ago.
Another study from Antarctica’s South Shetland Islands suggests RSL has plummeted by 10 meters just in the last 2,000 years after a 15-meter highstand 9,000 years ago.
There are regions in the northern hemisphere where RSL reached similarly high elevations as they did across East Antarctica.
The southeast coast of Sweden, i.e., the southern Baltic Sea, records RSL 22 meters higher than today from approximately 7,500 to 6,200 years ago (Katrantsiotis et al., 2023).
Read more at No Tricks Zone
