In Our Time: The Mariana Trench

From The Documentary Podcast by BBC World Service

April 29, 2026 · 49 min

About this episode

Misha Glenny and guests discuss the discovery and significance of the Mariana Trench.

Misha Glenny and guests discuss one of the wonders of the natural world. In 1875 in the western Pacific, the crew of HMS Challenger discovered the Mariana Trench which turned out to be deeper than Everest is high, by two kilometres. Trenches like Mariana form when one tectonic plate slips under another and heads down and there are around fifty of them globally. While at one time some thought it was too dark and deep for life there and others wildly imagined monsters, the truth has turned out to be much more surprising.

People in this episode

Host: Misha Glenny

Topics covered

natural wonders
oceanography
tectonic plates
marine life
exploration

Keywords

Mariana Trench
HMS Challenger
ocean depth
tectonic plates
marine life

Mentioned in this episode

Places: Mariana Trench, western Pacific, Everest