Sea level 80 m lower at a glance
- 17.3 million km²seabed becomes land
- 11.8%of today's land area
- 95.2%of today's sea remains (344.5 million km²)
- 8of 10 land bridges open
With the sea 80 m lower than today, about 17.3 million km² of seabed becomes land, 11.8% of today's land area. 95.2% of today's sea, about 344.5 million km² of the 361.8 million km² connected to the open ocean, is still under water.
The exposed area counts only seabed connected to the open ocean. Lakes stay water, and basins below sea level on land, such as Death Valley, stay land. It is a simple bathtub model, not a forecast.
Land bridges at this sea level
These places are seabed today and dry land at this step. Each depth is the average seabed level at the point we checked, taken from the 1 arc-minute grid.
| Land bridge | Depth today | Dry from |
|---|---|---|
| Doggerland (North Sea) | 43 m | 50 m lower |
| English Channel floor (opens at this step) | 58 m | 80 m lower |
| Irish Sea floor | 48 m | 50 m lower |
| Beringia (Bering Strait) (opens at this step) | 55 m | 80 m lower |
| Beringia (Chukchi shelf) (opens at this step) | 53 m | 80 m lower |
| Sundaland (Java Sea) | 40 m | 50 m lower |
| Sundaland (Gulf of Thailand) (opens at this step) | 63 m | 80 m lower |
| Sahul (Gulf of Carpentaria) (opens at this step) | 65 m | 80 m lower |
The list holds 10 places that we checked against the grid. It is not every land bridge there has been.
Seas that shrink most at 80 m lower
| Sea, gulf or bay | Becomes land | Share of its water |
|---|---|---|
| East Siberian Sea | 602,561 km² | 100% |
| Sea of Azov | 36,741 km² | 100% |
| Gulf of Carpentaria | 287,878 km² | 100% |
| Gulf of Tonkin | 111,320 km² | 100% |
| Bo Hai | 76,373 km² | 99.9% |
| Gulf of Thailand | 293,209 km² | 99.8% |
| Chukchi Sea | 335,117 km² | 99.6% |
| Kattegat | 22,192 km² | 96.5% |
The Caspian Sea is left out because it is a lake and stays water in this model.
Other sea levels
Frequently asked questions
How much land appears if sea level drops 80 m?
About 17.3 million km² of seabed becomes land, which is 11.8% of today's land area (147,036,202 km², lakes excluded). 95.2% of today's sea remains.
Which land bridges open at 80 m?
At this step English Channel floor, Beringia (Bering Strait), Beringia (Chukchi shelf), Sundaland (Gulf of Thailand), Sahul (Gulf of Carpentaria) first become dry land on the map. 3 more are already open from earlier steps.
Is this a forecast of sea level change?
No. It is a simple bathtub model that lowers the sea everywhere by the same amount, from today's coast, using the GEBCO_2026 grid. It does not simulate how the water would drain, how the land would adjust, or any past or future climate.
Data: land and depths from the GEBCO_2026 grid, lakes from Natural Earth. See data sources and licences. The GEBCO Grid should NOT be used for navigation or for any other purpose involving safety at sea.