You are here: /main/research expeditions/May 2005/Brooks Bank Mapping

Brooks Bank Mapping
by NWHI Mapping Team

Brooks Bank was recently mapped by the NOAA ship Hi`ialakai. The high resolution seafloor topography data reveals the flat-topped nature of many of the seamounts and atolls in the Northwestern Hawaiian Islands (NWHI) archipelago. These seamounts formed by erosion when their tops were near sea level. Brooks Bank has two distinct terraces at -75 and -125 m illustrating the affects of at least two distinct sea level stands on the Bank. There is over 500 m of relief between the top of Brooks Bank and the surrounding seafloor and large submarine canyons characterize the steep slopes below the incised edges of the Bank top.

Blocks of material at the base of the slopes are probably slumps or landslide deposits similar to material mapped around the Main Hawaiian Islands, believed to be deposited during catastrophic landslide events. Information gained from images like these give insight into the evolution of the Hawaiian Islands, provide base layers for benthic habitat mapping, and aid in NWHI Coral Reef Ecosystem Reserve boundary determination. NOAA is currently undertaking the enormous task of mapping the NWHI Coral Reef Ecosystem Reserve, the largest offshore protected area in the United States.