WASHINGTON : A deep-diving robot that chiseled into the rocky Pacific seabed at a spot where two of the immense plates comprising Earth’s outer shell meet has unearthed a previously unknown realm of animal life thriving underground near hydrothermal vents.
Giant tubeworms – the world’s heftiest worms – and other marine invertebrates such as snails and bristle worms were found using the remotely operated underwater vehicle SuBastian. They were living inside cavities within the Earth’s crust at an ocean-floor site where the Pacific is 1.56 miles (2,515 meters) deep. All the species were previously known to have lived near such vents, but never underground.
“We discovered vent animal life in the cavities of the ocean’s crust. We now know that the unique hydrothermal vent ecosystem extends into the ocean’s crust,” said marine biologist Sabine Gollner of the Royal Netherlands Institute for Sea Research, one of the leaders of the study published this week in the journal Nature Communications.
“To our knowledge, it is the first time that animal life has been discovered in the ocean crust,” Gollner added.
The exploration was conducted at the East Pacific Rise, a volcanically active ridge on the floor of the southeastern Pacific, running approximately parallel to South America’s west coast. Earth’s rigid outer part is divided into colossal plates that move gradually over time in a process called plate tectonics. The East Pacific Rise is located where two such plates are gradually spreading apart.
This area contains many hydrothermal vents, fissures in the seafloor situated where seawater and magma beneath the Earth’s crust come together. Magma refers to molten rock that is underground, while lava refers to molten rock that reaches the surface, including the seafloor. New seafloor forms in places where magma is forced upward toward the surface at a mid-ocean ridge and cools to form volcanic