Ocean Floor Map

Unnamed volcano: depth and map

Seamount or guyot: 70 m to the summit (GEBCO_2026 grid).

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Sea level in metres below today’s. A simple bathtub model: it lowers the sea everywhere by the same amount and does not simulate how the water would really drain.

Key

Sea depth

  • Deeper than 6,000 m
  • 4,000 to 6,000 m
  • 2,000 to 4,000 m
  • 1,000 to 2,000 m
  • 200 to 1,000 m
  • Shallower than 200 m (the continental shelf)

Land height

  • Land up to 500 m
  • 500 to 2,000 m
  • Above 2,000 m

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  • Seabed exposed when the sea is lowered A dashed white line marks today’s coast.

How to read the map. Darker blue is deeper water. Tap anywhere to see how deep the sea is there, or how high the land is, and the nearest named undersea feature. Depths come from the GEBCO_2026 grid, which in most of the deep ocean is predicted from satellite measurements of the sea surface rather than surveyed by ship, and the map’s tiles are coarser than the grid, so narrow trenches read shallower on the map than their true depth. Not for navigation.

Unnamed volcano at a glance

  • 70 mto the summit, in the grid
  • Seamount or guyottype of feature
  • 21.38° S, 175.65° Wlisted point
  • Tonganearest country, about 41 km
  • 500 mWikidata's own depth

Unnamed volcano is a seamount or guyot. Its summit is about 70 m below the surface in the GEBCO grid. That figure is the depth of the shallowest cell within 10 km of its listed point, which is its summit. The nearest country in our list is Tonga, about 41 km from its listed point.

Open the main map at its summit and tap anywhere to read the depth.

How deep is the Unnamed volcano?

The grid figure is 70 m. We measured it as the depth of the shallowest cell within 10 km of its listed point, which is its summit. The cell is at 21.34° S, 175.65° W. The GEBCO_2026 grid has a value every 15 arc-seconds, about 460 m at the equator, so a very narrow feature can be a little deeper or shallower in reality than any grid cell shows.

Wikidata gives 500 m, which is 430 m deeper than the grid figure of 70 m. Published depths for the same feature often differ like this: they can come from one ship's sounding of one spot rather than a gridded model, or refer to a different part of a long feature. We show both, and use the grid figure in our headline numbers because every depth on this site then comes from one source.

About seamounts and guyots

A seamount is an underwater mountain, usually an extinct volcano. A guyot is a seamount with a flat top, worn flat by waves when it once stood at the surface.

This site lists 420 seamounts and guyots, 115 of them with their own indexed page. See all undersea features.

Nearby undersea features

Distances are between listed points. A long feature such as a trench or ridge has a single listed point on Wikidata.

The highest seamount summits in our list

Frequently asked questions

How deep is the top of Unnamed volcano?

In the GEBCO grid the figure is 70 m. That is the depth of the shallowest cell within 10 km of its listed point, which is its summit. Wikidata gives 500 m, which is 430 m deeper than the grid figure of 70 m. Published depths for the same feature often differ like this: they can come from one ship's sounding of one spot rather than a gridded model, or refer to a different part of a long feature. We show both, and use the grid figure in our headline numbers because every depth on this site then comes from one source.

Where is the Unnamed volcano?

Its listed point is 21.38° S, 175.65° W, about 41 km from Tonga. The grid's shallowest cell for it is at 21.34° S, 175.65° W.

Data: depth from the GEBCO_2026 grid. Name and position from Wikidata Q24044817 (CC0). See data sources and licences. The GEBCO Grid should NOT be used for navigation or for any other purpose involving safety at sea.

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