Submarine Geomorphology and Seafloor Instabilities Revealed from Geophysical Data Offshore Southeastern Taiwan

Taiwan has excellent natural conditions for marine energy development. However, due to the active marine environment and geological processes, submarine geohazards must be carefully assessed before engineering development offshore southeastern Taiwan. Tectonically, it is situated in the oblique collision between the Eurasian Plate and the Philippine Sea Plate with fast exhumation and eroding transportation of sediments. Previous studies suggest that the Southern Longitudinal Trough (SLT) is characterized by a series of backthrusts and slumpings. Considering the rapid erosion and deposition led by extreme events, including typhoons and active tectonics, offshore SE Taiwan is an excellent site to study submarine geomorphology and seafloor instabilities.

After detailed structural and morphological analyses from seismic and bathymetry data, some geological features, faultings, gullies, and submarine canyon systems are recognized, moreover, several sliding scars and slumpings are interpreted from repeated and sequence surveys. It gives us insights into the potential mechanisms of sediment transportation and geological hazards by discussing the structure connections and distribution.

Since the study area has high ocean energy potential, appropriate site selection and development planning based on geological analysis should be carried out before marine industry projects. Whether in marine scientific research, site selection, engineering design, or social and economic development, studying geological processes and seabed stability offshore SE of Taiwan is urgent. Our results could provide a basis for subsequent seabed monitoring and engineering development.