The Mariana Trench reaches roughly seven miles below the ocean surface.
Notes on verification
Well-corroborated by multiple independent, reputable sources (Live Science, Smithsonian Ocean, Wikipedia/NOAA data). Exact figure is closer to 6.8 miles, but 'roughly seven miles' is a commonly used and reasonable approximation.
Sources
- The Pacific Ocean—facts and information (nationalgeographic.com)
- https://ocean.si.edu/planet-ocean/seafloor/mariana-trench (ocean.si.edu)
- https://www.fisheries.noaa.gov/pacific-islands/habitat-conservation/mariana-trench-marine-national-monument (fisheries.noaa.gov)
- https://www.britannica.com/place/Mariana-Trench (britannica.com)
- https://www.scientificamerican.com/article/the-mariana-trench-is-7-miles-deep-whats-down-there/ (scientificamerican.com)
- https://www.ncei.noaa.gov/news/planet-postcard-mariana-trench (ncei.noaa.gov)