Today’s sea levels are the lowest of the last several thousand years.
Carbon dating evidence from the elevation of abandoned penguin rookeries (and other proxies) reveal relative sea level (RSL) was ~30 m higher than today across East Antarctica about 8000 years ago (Small et al., 2025).
Following that highstand RSL fell rapidly at rates of 4 to 10 m per 1000 years. RSL was 24 m above present sea level (ASL) by 7200 years ago, 15 m ASL by 5700 years ago, 5 m ASL by 3200 years ago, and still 1 m 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 2000 years after a 15 m highstand 9000 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, the southern Baltic Sea, records RSL 22 m higher than today from approximately 7500 to 6200 years ago (Katrantsiotis et al., 2023).
[…] Related: New Study: 8000 Years Ago Relative Sea Level Was 30 Meters Higher Than Today Across East Antarctica […]