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Challenger Deep

earth science Maturity 7-9 Next article →

The Challenger Deep is the deepest known part of the ocean floor on Earth.

Marianatrenchmap
Marianatrenchmap

It is located in the western Pacific Ocean at the southern end of the Mariana Trench. This area is part of the ocean territory of the Federated States of Micronesia. The deep spot is a small, slot-shaped depression within a much larger, crescent-shaped trench.

Cross section of mariana trench
Cross section of mariana trench

It is a very important place for scientists to study. Understanding this deep spot helps us learn about our planet's hidden oceans.

GEBCO 2019 bathymetry Challenger Deep and Sirena Deep
GEBCO 2019 bathymetry Challenger Deep and Sirena Deep

This deep area is made of three distinct sections called basins. These basins are long, wide, and very deep. They sit in a line from west to east.

Challenger Deep EM124 Sonar Map and Diving History 101119
Challenger Deep EM124 Sonar Map and Diving History 101119

Small mounds of rock separate the three basins from each other. The western and eastern basins have recorded depths of over 10,000 meters. The center basin is a little less deep than the others. The floor of these basins has slopes and piles of rocks. These rocks sit on top of a soft layer called pelagic ooze.

Humans first found this place using old-fashioned tools. In 1875, a British ship named HMS Challenger found the area.

Gaskell HMS Challenger II
Gaskell HMS Challenger II

The crew used a weighted rope to measure how deep the water was. They were traveling near Guam when they found this deep spot. Later, the HMS Challenger II investigated the area between 1950 and 1952. This ship used a taut wire with 140 pounds of scrap iron to find the depth. The name Challenger Deep honors both of these famous British ships.

Measuring the exact depth of the ocean is a hard job. Scientists often use sonar, which is a system that uses sound to map the floor.

Hakuho Maru, Fremantle, 2019 (06)
Hakuho Maru, Fremantle, 2019 (06)

They must account for how the speed of sound changes in the water. This speed changes based on temperature, pressure, and how much salt is in the water. A study from 2011 placed the depth at 10,994 meters. A more recent study in 2021 revised this value to 10,935 meters. Researchers continue to use many different vessels to find the most accurate numbers.

Going to the bottom of the Challenger Deep is a rare feat. The first time a vehicle went down there was in January 1960.

Bathyscaphe Trieste Piccard-Walsh
Bathyscaphe Trieste Piccard-Walsh

The United States Navy used a special craft called the Trieste for this dive. Since that first trip, only 27 people have ever descended to the bottom. This makes the Challenger Deep one of the most difficult places for humans to visit. It remains a place of great wonder for everyone who studies the sea.

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🖼️ Images & Media (23)
File:Marianatrenchmap.png
Marianatrenchmap.png
File:Challenger Deep EM124 Sonar Map and Diving History 101119.jpg
Challenger Deep EM124 Sonar Map and...
File:Gaskell HMS Challenger II.jpg
Gaskell HMS Challenger II.jpg
File:Kaliningrad 05-2017 img62 Ocean Museum.jpg
Kaliningrad 05-2017 img62 Ocean Museum.jpg
File:Cross section of mariana trench.svg
Cross section of mariana trench.svg
File:Hakuho Maru, Fremantle, 2019 (06).jpg
Hakuho Maru, Fremantle, 2019 (06).jpg
File:JAMSTEC Yokosuka P5123676.jpg
JAMSTEC Yokosuka P5123676.jpg
File:JAMSTEC Deep Sea Research Ship Kairei P7214312.jpg
JAMSTEC Deep Sea Research Ship Kairei P7214312.jpg
File:RV Melville (25635910745).jpg
RV Melville (25635910745).jpg
File:US Navy 090814-N-0000X-001 The Office of Naval Research small waterplane area twin-hull oceanographic research ship R-V Kilo Moana takes part in the second Radiance in a Dynamic Ocean (RaDyO) program.jpg
US Navy 090814-N-0000X-001 The Office of...
File:JAMSTEC Deep Sea Research Ship Kairei P7224519.jpg
JAMSTEC Deep Sea Research Ship Kairei P7224519.jpg
File:USCGC Sequoia (WLB-215).jpg
USCGC Sequoia (WLB-215).jpg

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