* Deep-sea life: Thomson and his team discovered a vast array of previously unknown life forms living in the deep sea, including new species of fish, invertebrates, and microorganisms. This challenged the prevailing belief that no life could exist at such depths.
* Ocean floor topography: The Challenger expedition meticulously mapped the ocean floor, revealing its complex and varied topography, including mountains, trenches, and vast plains. This data laid the foundation for modern oceanography.
* Ocean currents: Thomson studied ocean currents and their influence on marine life and climate, helping to develop our understanding of global ocean circulation.
* Marine sediments: The expedition collected and analyzed vast amounts of marine sediments, providing insights into the geological history of the oceans and the processes that shape the Earth.
* The concept of the "Challenger abyss": This term was coined by Thomson to describe the deepest part of the ocean floor, which they discovered during the expedition. It later gave way to the term "Mariana Trench".
Thomson's work on the Challenger expedition was a monumental achievement in science, fundamentally changing our understanding of the oceans and the life within them. He is considered one of the pioneers of modern oceanography.