The Mariana Trench's Challenger Deep plunges 10,994 metres below sea level — the deepest known point in any ocean on Earth.
Quick answer: 1. Challenger Deep, Mariana Trench, 2. Tonga Trench (Horizon Deep), 3. Kuril-Kamchatka Trench, 4. Emden Deep, Philippine Trench, 5. Kermadec Trench, 6. Izu-Ogasawara Trench, 7. Japan Trench, 8. South Sandwich Trench, 9. Puerto Rico Trench (Milwaukee Deep), 10. Mo'o Pa'au, Tonga Trench (second deep).
The ocean floor is not flat. Subduction zones where tectonic plates collide create deep trenches that plunge far below the surrounding seabed. The deepest of these — the hadal zone, named after Hades, the Greek underworld — reaches depths that exceed the height of Mount Everest turned upside down. This list ranks the ten deepest known points in the world's oceans by their maximum recorded depth below sea level, using data from the Five Deeps Expedition and the Global Multi-Resolution Topography synthesis.
The deepest known point on Earth, located in the Mariana Trench of the western Pacific Ocean. The Five Deeps Expedition measured it at 10,994 metres in 2019, though the exact depth varies slightly between surveys. It was first visited by Jacques Piccard and Don Walsh in the bathyscaphe Trieste in 1960.
The Tonga Trench in the southwest Pacific Ocean reaches depths of over 10,800 metres. The Five Deeps Expedition measured the Horizon Deep at 10,823 metres in 2019, making it the second-deepest point on Earth and the deepest point in the Southern Hemisphere.
The Kuril-Kamchatka Trench lies off the coast of Kamchatka, Russia, in the northwest Pacific. Its maximum depth of approximately 10,542 metres makes it the third-deepest trench, created by the subduction of the Pacific Plate beneath the Okhotsk Plate.
The Philippine Trench, also known as the Mindanao Trench, reaches depths of approximately 10,540 metres. The Emden Deep was named after the German cruiser SMS Emden and was the third point visited during the Five Deeps Expedition.
The Kermadec Trench extends northeast from New Zealand's North Island. Its deepest point reaches approximately 10,047 metres, making it the fifth-deepest trench. It is part of the Pacific Ring of Fire and is one of the most seismically active regions on Earth.
The Izu-Ogasawara Trench, also known as the Bonin Trench, lies south of Japan in the western Pacific. Its maximum depth of approximately 9,810 metres places it sixth among the world's deepest ocean points.
The Japan Trench extends east of the Japanese archipelago, where the Pacific Plate subducts beneath the Okhotsk Plate. Its maximum depth of approximately 9,000 metres was the epicentre region of the 2011 Tōhoku earthquake and tsunami.
The South Sandwich Trench in the southern Atlantic Ocean is the deepest point in the Atlantic and the Southern Ocean. The Five Deeps Expedition measured its deepest point at 8,428 metres, making it the eighth-deepest ocean trench on Earth.
The Puerto Rico Trench is the deepest point in the Atlantic Ocean and the Caribbean Sea. The Milwaukee Deep, its deepest point at approximately 8,376 metres, lies north of Puerto Rico and was formed by the subduction of the North American Plate beneath the Caribbean Plate.
The Five Deeps Expedition identified a second deep point in the Tonga Trench system, named Mo'o Pa'au ("lizard's tail" in Tongan). This distinct basin reaches 8,310 metres, making it the tenth-deepest known ocean point and the deepest point in the South Pacific Gyre.
| # | Name | Depth | Trench | Ocean | Location | First visited |
|---|---|---|---|---|---|---|
| 1 | Challenger Deep, Mariana Trench | 10,994 m | Mariana Trench | Pacific Ocean | Western Pacific, near Guam | 1960 |
| 2 | Tonga Trench (Horizon Deep) | 10,823 m | Tonga Trench | Pacific Ocean | Southwest Pacific, near Tonga | 2019 (Five Deeps) |
| 3 | Kuril-Kamchatka Trench | 10,542 m | Kuril-Kamchatka Trench | Pacific Ocean | Off Kamchatka, Russia | Unmanned surveys |
| 4 | Emden Deep, Philippine Trench | 10,540 m | Philippine Trench | Pacific Ocean | East of the Philippines | 2019 (Five Deeps) |
| 5 | Kermadec Trench | 10,047 m | Kermadec Trench | Pacific Ocean | Northeast of New Zealand | Unmanned surveys |
| 6 | Izu-Ogasawara Trench | 9,810 m | Izu-Ogasawara Trench | Pacific Ocean | South of Japan | Unmanned surveys |
| 7 | Japan Trench | 9,000 m | Japan Trench | Pacific Ocean | East of Japan | Unmanned surveys |
| 8 | South Sandwich Trench | 8,428 m | South Sandwich Trench | Atlantic Ocean | South of the South Sandwich Islands | 2019 (Five Deeps) |
| 9 | Puerto Rico Trench (Milwaukee Deep) | 8,376 m | Puerto Rico Trench | Atlantic Ocean | North of Puerto Rico | Unmanned surveys |
| 10 | Mo'o Pa'au, Tonga Trench (second deep) | 8,310 m | Tonga Trench | Pacific Ocean | Southwest Pacific, near Tonga | 2019 (Five Deeps) |
Points are ranked by their maximum recorded depth in metres below sea level. Data is drawn from the 2019-2020 Five Deeps Expedition (which used direct CTD and sonar measurements with pressure sensors calibrated to ±1 metre) and the GEBCO global bathymetric dataset. Only confirmed ocean-floor points are included; subglacial or sub-surface features are excluded. Rank 1 is the deepest point. All measurements are in metres below sea level.
The Challenger Deep in the Mariana Trench is the deepest known point on Earth, reaching 10,994 metres below sea level as measured by the 2019 Five Deeps Expedition.
Modern measurements use pressure-calibrated CTD instruments and multibeam sonar. The Five Deeps Expedition used direct depth sensors with ±1 metre accuracy, a significant improvement over earlier echo-sounding estimates.
The Pacific Ocean contains the seven deepest points on Earth. The Mariana, Tonga, Philippine, and Kuril-Kamchatka trenches all exceed 10,500 metres.
The Puerto Rico Trench's Milwaukee Deep reaches 8,376 metres, though the South Sandwich Trench in the southern Atlantic is deeper at 8,428 metres, technically making it the deepest point in the Atlantic Ocean basin.