Current Structure and Preliminary Indication of Mentawaian-Jet in the Southeastern Mentawai Waters, Indonesia

Abstract

The baseline observations of water current in the southeastern Mentawai waters using Shipboard Acoustic Doppler Current Profiler (SADCP) of the RV Baruna Jaya VIII in April 2013 were presented study. This study aims to reveal the current subsurface system in the internal western Sumatra waters, the southeastern Mentawai Islands waters. We found unique hydrodynamics in this region where the southeastward flows were observed in the upper 50 m yet persistent northwestward flow below. We suggest that the southeastward flows in the upper layer were the remaining Southeast Monsoon-driven circulations. The northwestward flows below were likely acting as counter-current due to continuity processes in this semi-enclosed sea. This counter-current exceeds 1 m s−1 at a depth of>125 m, a localized jet-like current. We propose to name this high magnitude current as Mentawaian Jet as it feeds the western Sumatra internal waters.