Today’s Antarctic sea levels lowest in last several thousand years
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)
Following that highstand, RSL fell rapidly at rates of four 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, five meters ASL by 3,200 years ago, and still one meter ASL about 800 years ago.
Image Source: Small et al., 2025
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.
Image Source: Watcham et al., 2011
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).
Image Source: Katrantsiotis et al., 2023
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