What may look like a "yellow brick road" to the mythical city of Atlantis is really an example of ancient active volcanic geology! Our Corps of Exploration have witnessed incredibly unique and fascinating geological formations while diving on the Liliʻuokalani Ridge within Papahānaumokuakea Marine National Monument. At the summit of Nootka Seamount, the team spotted a "dried lake bed" formation, now IDed as a fractured flow of hyaloclastite rock (a volcanic rock formed in high-energy eruptions where many rock fragments settle to the seabed). The unique 90-degree fractures are likely related to heating and cooling stress from multiple eruptions at this baked margin. Throughout the seamount chain, the team also sampled basalts coated with ferromanganese (iron-manganese) crusts from across different depths and oxygen saturations as well as an interesting-looking pumice rock that almost resembled a sponge.
Our exploration of this never-before-surveyed area is helping researchers take a deeper look at life on and within the rocky slopes of these deep, ancient seamounts. Scientists are studying the microbial communities residing within the ferromanganese crusts found over rock surfaces and how the characteristics of the crusts vary from region to region in ocean basins as well the microorganisms that live on and within them. These studies will help provide baseline information on the living communities of seamounts which can inform management and conservation measures.
Learn more about this expedition funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute with additional support from the NOAA Office of National Marine Sanctuaries: https://nautl.us/37kH3ol