EarthMapped Ocean floor
World map of ocean depth with mid-ocean ridges and trenches

Ocean Floor Map

The ocean floor is mostly a deep plain between 3,000 and 6,000 m down, crossed by mid-ocean ridges where plates spread apart and cut by deep trenches where they sink. This map shows 12 depth bands with the ridges and trenches on top.

  • Bathymetry. The study of the floors of the ocean, lakes and rivers: how deep the water is and the shape of the bottom. Source
  • Mid-ocean ridge. An underwater mountain range that forms along divergent plate boundaries, where new ocean floor is made. Source
  • Subduction zone. Where one plate sinks under another and back into the mantle, usually marked by a deep ocean trench. Source
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Data source: Natural Earth 1:10m bathymetry (from SRTM30 Plus), Public domain. Download: Depth GeoJSON .

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What the map shows

Colors show how deep the water is Bathymetry. The study of the floors of the ocean, lakes and rivers: how deep the water is and the shape of the bottom. Source , from pale blue near the coasts to dark blue in the trenches. Each band is a depth range from the Natural Earth bathymetry. On top are two kinds of plate boundary from the PB2002 model: red mid-ocean ridges Mid-ocean ridge. An underwater mountain range that forms along divergent plate boundaries, where new ocean floor is made. Source , where plates move apart, and dark blue trenches, where one plate sinks under another Subduction zone. Where one plate sinks under another and back into the mantle, usually marked by a deep ocean trench. Source . Dots mark the deepest measured point of each ocean.

The shape of the sea floor

Close to land is a shallow shelf, the palest band. Past it the floor drops away to wide, deep plains, which make up most of the map. The ridges rise from these plains as a single chain that winds through every ocean. The deepest places are not in the middle of the oceans but at their edges, in narrow trenches, most of them around the Pacific.

Key facts

  1. The average depth of the ocean is about 3,682 m (12,080 feet). NOAA Ocean Service, How deep is the ocean?
  2. The deepest known point is the Challenger Deep in the Mariana Trench, measured at 10,924 ±15 m by the Five Deeps Expedition. Bongiovanni, Stewart and Jamieson (2022), Geoscience Data Journal 9(1)
  3. On this map, the 4,000 to 5,000 m band covers the most sea floor: 31.2% of the ocean. Depths of 3,000 to 6,000 m together cover 73%.
  4. Water less than 200 m deep covers 7.9% of the ocean. Depths beyond 6,000 m cover only 0.66%.
  5. The PB2002 plate model maps 67,367 km of spreading ridge and 51,309 km of subduction zone. PB2002 plate model, Bird (2003), converted by Hugo Ahlenius, Nordpil
  6. As of April 2026, 28.7% of the global sea floor had been mapped with modern high-resolution multibeam sonar. NOAA Ocean Service, How much of the ocean have we explored?

How much sea floor lies at each depth

Area of each depth band on the Natural Earth polygons, as a share of the whole ocean (363,345,408 km²).

Ocean area by depth band
DepthArea (km²)Share of ocean (%)
0 to 200 m 28,833,925 7.94
200 to 1,000 m 17,150,562 4.72
1,000 to 2,000 m 17,252,321 4.75
2,000 to 3,000 m 33,932,272 9.34
3,000 to 4,000 m 84,780,982 23.33
4,000 to 5,000 m 113,497,553 31.24
5,000 to 6,000 m 65,506,669 18.03
6,000 to 7,000 m 2,080,674 0.57
7,000 to 8,000 m 199,209 0.05
8,000 to 9,000 m 93,571 0.03
9,000 to 10,000 m 16,569 under 0.01
10,000 m and deeper 1,102 under 0.01

Data source: Natural Earth 1:10m bathymetry (from SRTM30 Plus), Public domain. Download: Depth GeoJSON , Depth zones CSV .

Deepest point of each ocean

Deepest measured point of each ocean
OceanDeepest pointDepth (m)
Pacific Challenger Deep (Mariana Trench) 10,924 ±15
Atlantic Brownson Deep (Puerto Rico Trench) 8,378 ±5
Southern Unnamed (South Sandwich Trench) 7,432 ±13
Indian Unnamed (Java Trench) 7,187 ±13
Arctic Molloy Hole (Sea floor between Greenland and Svalbard) 5,551 ±14

Data source: Bongiovanni, Stewart and Jamieson (2022), Five Deeps Expedition, CC BY 4.0. Download: Deepest points CSV .

Follow the spreading centers on the mid-ocean ridge map and the sinking plates on the subduction zones map. See every deep trench on the ocean trenches map, zoom in on the Mariana Trench, or read about the Pacific Plate and all tectonic plates.

Print this map Ocean currents worksheet. Label the currents and the five gyres, with an answer key

Glossary

Bathymetry
The study of the floors of the ocean, lakes and rivers: how deep the water is and the shape of the bottom. Source
Mid-ocean ridge
An underwater mountain range that forms along divergent plate boundaries, where new ocean floor is made. Source
Subduction zone
Where one plate sinks under another and back into the mantle, usually marked by a deep ocean trench. Source

All terms in the glossary

Ocean floor FAQ

How deep is the ocean floor on average?
NOAA gives an average depth of about 3,682 m (12,080 feet). On this map the most common depth band is 4,000 to 5,000 m.
What is the deepest part of the ocean floor?
The Challenger Deep in the Mariana Trench, measured at 10,924 ±15 m by the Five Deeps Expedition. See the Mariana Trench map.
Has the whole ocean floor been mapped?
Only in low detail. Satellite data gives a general picture of the whole floor, but NOAA says that as of April 2026 only 28.7% had been mapped with high-resolution multibeam sonar.
What are the long lines on the ocean floor?
The red lines are mid-ocean ridges, where plates spread apart and new sea floor forms. The dark blue lines are trenches, where one plate sinks under another. See the mid-ocean ridge map and the subduction zones map.
Where does the depth data come from?
From the Natural Earth 1:10m bathymetry, a public domain set of depth polygons made from the SRTM30 Plus data. It is a generalized picture, good for a world map but not for navigation.

Sources: NOAA Ocean Service, How deep is the ocean?; NOAA Ocean Service, How much of the ocean have we explored?; Bongiovanni, Stewart and Jamieson (2022), Geoscience Data Journal 9(1); NOAA Ocean Service, What is bathymetry?.