The deep-sea researcher was the only one with a submarine, and a year later, her exploration team had raised enough money to go back.
When Tunnicliffe finally descended over 2,000 metres to a patch of ocean floor, everything was dark, save for the light on the submersible.
Below them, two tectonic plates diverged, allowing cold sea water to seep through the Earth’s crust. Super-heated by molten lava, the water shoots back into the ocean as a 400-degree-Celsius hot soup of nutrients and chemicals.
The crew crept along the bottom in an exercise Tunnicliffe describes as “trying to explore the Rocky Mountains with a flashlight.”
First came white mats of bacteria. Then, out of the darkness, huge mounds of “gorgeous” white tube worms emerged, the metre-and-a-half-long creatures topped with red plumes. Inside, the scientist would later learn they had no guts, but a body filled with vent-fed bacteria that feed the…


