Bosporus at a glance
- 32 maverage depth
- 26 mmedian depth
- 109 mmaximum depth
- 67 km²water area
Bosporus is a strait. Inside its outline the GEBCO grid has about 67 km² of water, with an average depth of about 32 m (the middle value is 26 m) and a maximum of 109 m, found at 41.21° N, 29.13° E.
Open the map at the deepest cell and tap to read the depth.
How deep is each part of the Bosporus?
The bar splits the Bosporus's water by depth. Each colour is a depth band, and the shares add up to 100%.
- 0 to 200 m: 100%
- 200 to 1,000 m: 0%
- 1,000 to 4,000 m: 0%
- 4,000 to 6,000 m: 0%
- below 6,000 m: 0%
Named features near the deepest point: Danube Canyon (324 km), Calypso Deep (863 km), Eratosthenes Seamount (895 km), Herodotus Basin (918 km).
The Bosporus if sea level dropped
The slider on the map lowers the sea in steps. This table shows how much of the Bosporus's water would be land at each step.
| Sea level lowered by | Becomes land | Share of its water |
|---|---|---|
| 10 m | 10 km² | 15.3% |
| 20 m | 21 km² | 30.8% |
| 50 m | 52 km² | 77% |
| 80 m | 67 km² | 100% |
| 120 m | 67 km² | 100% |
| 200 m | 67 km² | 100% |
| 500 m | 67 km² | 100% |
| 1,000 m | 67 km² | 100% |
| 2,000 m | 67 km² | 100% |
| 3,000 m | 67 km² | 100% |
| 4,000 m | 67 km² | 100% |
| 6,000 m | 67 km² | 100% |
A simple bathtub model: it lowers the sea everywhere by the same amount and does not simulate how water would really drain.
Nearby seas
- Sea of Marmara average depth about 319 m
- Aegean Sea average depth about 306 m
- Black Sea average depth about 1,300 m
- Sea of Crete average depth about 696 m
- Sea of Azov average depth about 9 m
- Ionian Sea average depth about 2,122 m
Nearest by the centre of each outline. All oceans and seas
Frequently asked questions
How deep is the Bosporus?
On average about 32 m in the GEBCO grid (the middle value is 26 m). The deepest cell inside its outline is 109 m, at 41.21° N, 29.13° E.
How big is the Bosporus?
About 67 km² of water inside its Natural Earth outline, counted from the grid cells that are below sea level.
How much of the Bosporus would be land if sea level dropped?
With the sea 10 m lower, about 10 km² (15.3%) of its water would be land. At 6,000 m lower, 100% would be. This is a simple bathtub model that lowers the sea evenly everywhere.
Data: depths from the GEBCO_2026 grid, statistics worked out inside the Natural Earth outline of the strait. See data sources and licences. The GEBCO Grid should NOT be used for navigation or for any other purpose involving safety at sea.