17 May – 20 June 2026
#Doldrums
Our planet’s longest mountain range is located in the center of the Atlantic Ocean: the Mid-Atlantic Ridge. This submarine volcanic mountain chain stretches for more than 16,000 kilometers, shaping Earth’s geology where tectonic plates drift apart. As the plates separate, mantle material rises, partially melts, and generates magma that forms new oceanic crust. The movement of plates forms wrinkles and lines along the planet’s surface, known as fault zones, which tell the story of Earth’s tectonic history. These fault zones circulate water into the seafloor and through the crust, later releasing it with new chemical compositions— some of which feed deep-sea bacteria that fuel thriving ecosystems in the deepest, darkest parts of the Ocean. While chemosynthetic ecosystems are well documented along the ridge, little is known about what lives on the fault zones.

The Doldrums Megatransform System is one of these fault zones formed where offset ridge segments are linked by transform faults as the Atlantic seafloor spreads apart. Here, tectonic plates scrape and slide past one another, creating fascinating geologic formations like fault scarps and sedimented basins, both of which can host areas of chemically altered seawater and deep-sea ecosystems. Dr. Aaron Micallef of MBARI (Monterey Bay Aquarium Research Institute) and the international team will travel to the Doldrums Fracture Zone to map and identify interesting geological features, and then use ROV SuBastian to visualize them. Key to their work will be The Childlike Empress AUV, which will both create high-resolution maps of the seafloor and use its sensors to sniff out interesting chemicals that indicate venting. This expedition marks the first time Schmidt Ocean Institute’s new AUV will be used for scientific research.