The Ice Age sea level at a glance
- 21.7 million km²seabed becomes land
- 14.8%of today's land area
- 94%of today's sea remains (340.1 million km²)
- 10of 10 land bridges open
A drop of 120 m is about the lowest sea level of the last Ice Age, when great ice sheets held a lot of the world's water. On this map it exposes 21.7 million km² of seabed, 14.8% of the land area we have today (measured against 147,036,202 km² of land, lakes excluded). Most of it is shallow continental shelf, and several famous land bridges are dry.
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.
Doggerland: the land that is now the North Sea
Doggerland is the name archaeologists give to the land that once joined Britain to the rest of Europe. Our data has no named outline for it, so the map builds it from the seabed. The middle of the North Sea sits about 43 m below today's sea level, so it is dry once the sea is lowered by 50 m. At 120 m, 416,596 km² of the North Sea's 492,936 km² is land, which is 85% of it. See the North Sea depth map.
Doggerland was a low-lying land of marshes and rivers where people could once hunt and settle. As the ice sheets melted after the last Ice Age the sea rose and flooded it, slowly turning a land that joined Britain to Europe into the North Sea, and leaving Britain as an island. Fishing boats still pull up animal bones and stone tools from the North Sea floor. The map cannot show when this happened, only how much land the sea covers today at each level.
Ice Age land bridges on the map
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 | 58 m | 80 m lower |
| Irish Sea floor | 48 m | 50 m lower |
| Beringia (Bering Strait) | 55 m | 80 m lower |
| Beringia (Chukchi shelf) | 53 m | 80 m lower |
| Sundaland (Java Sea) | 40 m | 50 m lower |
| Sundaland (Gulf of Thailand) | 63 m | 80 m lower |
| Sahul (Arafura Sea) (opens at this step) | 111 m | 120 m lower |
| Sahul (Gulf of Carpentaria) | 65 m | 80 m lower |
| Bass Strait (Tasmania) (opens at this step) | 81 m | 120 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 120 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 Thailand | 293,746 km² | 100% |
| Gulf of Carpentaria | 287,878 km² | 100% |
| Gulf of Tonkin | 111,363 km² | 100% |
| Chukchi Sea | 336,604 km² | 100% |
| Yellow Sea | 369,064 km² | 100% |
| Bo Hai | 76,411 km² | 99.9% |
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 120 m?
About 21.7 million km² of seabed becomes land, which is 14.8% of today's land area (147,036,202 km², lakes excluded). 94% of today's sea remains.
What was Doggerland?
Doggerland is the name given to the land that stood where the North Sea is now. On the map the floor of the North Sea, about 43 m below today's sea level at its middle, is dry from a 50 m drop, and at 120 m about 416,596 km² of the North Sea's 492,936 km² is land. It joins Britain to the continent, along with the English Channel floor.
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.