Source: US Geological Survey
Research Purpose and Objectives
Scientists from the US Geological Survey (USGS), the University of Hawaiʻi at Mānoa, Scripps Institution of Oceanography, and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will conduct ship-based research in the deep waters and seafloor far offshore the Hawaiian Islands in Fall 2024. The team, with its broad range of expertise in biology, geology, and oceanography, will study marine minerals and their environmental setting—the microbes and animals that coexist with them and the characteristics of the surrounding sediments and seawater—in the deepest and least scientifically characterized parts of the ocean, known as the abyssal plains.
Abyssal Plains and Manganese Nodules
Abyssal plains exist at depths between 3,000 and 6,000 meters (9,800 to 19,700 feet) and constitute more than 70 percent of the global seafloor. Processes driving the geology and biology of these deep-sea environments remain largely unstudied. To facilitate understanding of global abyssal seafloor settings given the very little physical data available, scientists use large-scale factors like sedimentation rate, surface primary productivity, and bathymetry to predict the geologic features, marine minerals, and ecosystems that are likely to occur. In the abyssal regions about 230 miles (~370 kilometers) south of the Island of Hawaiʻi, oceanographic and geologic evidence indicate that manganese nodules may be present on the seafloor.
Abyssal manganese nodules—concretions smaller than a fist that are mainly composed of iron and manganese and form very slowly, at rates of millimeters per million years—offer a distinct habitat for local fauna compared to the surrounding sediment-covered seafloor. Since these nodules form in layers, they can offer unique insights into the geochemistry of the ocean going back millions of years, yet their formation, regional distribution, and interaction with their environment is still not well understood.
The research expedition will characterize the abyssal plain south of Hawai’i, focusing on the interaction of geology and biology within a holistic mineral-environment system.
Scientists will: