On this day in history...
...in 1872, the HMS Challenger departed from England to nearly four years of groundbreaking exploration (December 1872 – May 1876). This pioneering voyage is often regarded as the birth of modern oceanography, including physical oceanography.
The expedition systematically measured ocean temperature, salinity, currents, and depth at hundreds of locations across the world’s oceans. The team deployed weighted lines to determine seabed depths, laying the groundwork for modern bathymetry, and recorded the first comprehensive observations of global ocean circulation.
One of the expedition's key contributions to physical oceanography was its extensive dataset on the distribution of deep-sea temperatures. These measurements confirmed the existence of cold, dense water masses at great depths, supporting the concept of thermohaline circulation—an essential process driving global ocean currents.
The findings of the HMS Challenger expedition were published in a monumental 50-volume report, providing a wealth of knowledge that continues to shape oceanographic studies to this day.
Source
- https://www.rmg.co.uk/stories/blog/library-archive/telling-story-challenger-expedition-1872-76
- https://www.rsgs.org/blog/the-challenger-expedition-peering-into-the-abyss
- https://en.wikipedia.org/wiki/Challenger_expedition
- https://oceanexplorer.noaa.gov/explorations/03mountains/background/challenger/challenger.html