抄録
In October to November, 2009, a multi-beam bathymetry survey had been successfully completed in the outer-arc high off northwest Sumatra during the KY09-09 cruise using R/V KAIYO of JAMSTEC (Japan Agency for Marine-Earth Science and Technology). Then KY09-09 bathymetry data were integrated with a previous NT05-02 bathymetry data to make a new detailed bathymetry map, gridded at approximately ∼37 m cell size, in the middle part of the outer-arc high. The most predominant morphological feature is the NNW trending sigmoidal structures consisting of a series of ridges and troughs parallel to the local trench, which is more evident trenchward than landward. Secondary predominant structure is the N-S to NE-SW trending ridges and adjoining V shaped valleys that offset the most predominant structures from north to south in the middle part of the integrated map area. Third predominant structure is the NNE to NE narrow valleys that cut the NNW trending sigmoidal structures elsewhere in the whole integrated map area.
