Method for determining the foot point of continental slope in complex geological background: Take the southern continental margin of Mozambique as an example

doi:10.3969/j.issn.1001-909X.2024.01.002

Abstract

Abstract:

A new method for determining the foot point of the continental slope (FOS) was proposed for the delineation of the continental shelf in a complex geological context. This method calculated the location of the foot of slope based on the mean gradient of water depth and optimized it by combining the contrary evidence and the principles of convexity, segmentation and continuity. Using the southern continental margin of Mozambique as the study area, the method was applied to extract the most critical basis—FOS for continental shelf delineation using high-precision multibeam topographic data measured in 2021, and the result was confirmed by comparison with those extracted by the Geocap software which is used by the United Nations Commission on the Limits of the Continental shelf, proving the effectiveness and accuracy of this method.

Key words: delimitation of continental shelf, foot point of slope, average gradient changes, southern continental margin of Mozambique

CLC Number:

P229.6

ZHUANG Baojiang, TANG Yong, LÜ Xiaohui, YANG Chunguo, WU Zhaocai, LI He. Method for determining the foot point of continental slope in complex geological background: Take the southern continental margin of Mozambique as an example[J]. Journal of Marine Sciences, 2024, 42(1): 13-22.

Figures/Tables 9

Fig.1 Regional tectonic map of the southern margin of Mozambique (The figure is modified from reference [14]. MCSP003 shows the location of the multibeam and seismic profile investigated in this study.)

Fig.2 Survey line and FOS in southern continental margin of Mozambique

Fig.3 Multibeam terrain (a) and 3D terrain display map (b) (The red arrow shows the submarine canyons and depressions corresponding to the three-dimensional topography.)

Fig.4 Sketch map of Geocap average slope

Fig.5 Finite difference fitting and first and second derivative graph

Fig.6 Comparison of topographic profile and slope change under finite difference fitting

Fig.7 Comparison of topographic profile and mean gradient change at different step lengths

Fig.8 Topographic variation and geophysical characteristics in the southern continental margin of Mozambique

Fig.9 FOS analysis using Geocap

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