Seafloor Imaging Exploration off the Northeastern Coast of Taiwan Using a Deep-towed Vehicle

The northeastern part of Taiwan, characterized by volcanic formations from tectonic plate collisions, includes the Datun and Keelung Volcanic Groups and volcanic islands such as Keelung, Huaping, Mienhua, and Pengjia Islets. Recent discoveries of submarine volcanoes off Taiwan's northeastern coast highlight potential for polymetallic hydrothermal sulfide deposits, presenting opportunities for economic and scientific exploration. Utilizing the deep-towed vehicle Abyss Twisted-pair Imaging System (ATIS), seafloor imaging surveys were conducted from 2020 to 2023, covering 25.68 kilometers over 36.24 hours. Key observations include sandy seafloors with hydrothermal activity indicated by abrupt changes in water temperature and gas emissions in the Keelung Islet area; large igneous rocks and hydrothermal activity across eight sites in the Huaping Islet area; and similar large igneous rocks and hydrothermal activity in the Mienhua and Pengjia Islet areas. These findings support ongoing exploration and resource evaluation, providing crucial data for geophysical and geochemical analysis.