Water properties and bottom water patterns in hadal trench environments

We examine baseline water properties and bottom water patterns in hadal trench environments across the Southern Ocean, Indian Ocean, and Western Pacific. Significant differences are identified in the South Fiji Basin and surrounding the Philippine Sea, primarily due to the movement of cold Lower Circumpolar Deep Water along topographic features, highlighting the importance of a trench’s geospatial position. We present the first hydrographic profiles in the Java Trench, warranting further research. Increases in salinity patterns in depths over 10,000 dbar are investigated, with potential causes including instrumentation error, internal mixing, and saline pore water expulsion. These hadopelagic variations are crucial for assessing climate change impacts, especially regarding Antarctic Bottom Water. The study underscores the importance of incorporating these adiabatic conditions for insights into ecological biodiversity, alongside the baseline conditions presented being indispensable for future oceanographic research across multiple disciplines.