QUANTITATIVE ANALYTICAL RESULTS ON TOPOGRAPHIC FEATURE OF THE VIETNAM’S CONTINENTAL SHELF WITHIN COORDINATES 11.7 - 14.00 AND 109.5 - 110.20

Abstract

This paper presents some analytical results of bathymetry data according to three maps: Three dimensions (3D), slope, aspect on the continental slope and shelf area in the central part of Vietnam within the coordinates of 11.7 - 14.0⁰ and 109.5 - 110.2⁰. The obtained results have reflected clearly the geomorphic characteristics in this area. For example, on the 3D map, the continental slope exists three steps at the depths of 500 - 700 m, 1,250 m, and 1,500 - 1,700 m, running along the meridian 109.7⁰, about 250 km long. These results are also shown on the slope and aspect map. On the slope map, from the depth of about 250 m to the first step base, the slope angle varies within 5 - 20⁰ and from the first step base to second step base, the slope angle varies within 5 - 10⁰; In the remaining part, the slope angle varies within 2 - 8⁰. The other analytical results from the aspect map are also shown clearly, the aspect direction on the wall of three slope steps varies from 50 to 100⁰, reflecting the topographic slope towards the east, where is abyssal plain. The existence of Pliocene - Quaternary sediments along with steep continental slope caused landslide phenomenon in this area.