多波束测深技术在洋中脊构造地貌解译中的应用

The Application of the Multi-beam Echo Sounding Technique in Tecto-geomorphic Interpretation of Mid-ocean Ridges

多波束测深技术在国际上是海洋科学研究、海底资源开发和海洋工程建设中的重要技术手段。基于对国内外多波束地形数据的广泛调研,对洋中脊附近洋底构造地貌形态进行分析研究。文中利用不同扩张速率洋中脊附近的50 m分辨率的多波束地形数据,基于数字地形空间分析方法,利用不同滑动窗口和阈值自动识别来提取洋中脊附近地形面的最大、最小曲率以及坡度,并以此对洋中脊进行构造解译。对中大西洋洋中脊和东太平洋洋隆两个实验结果的定量分析表明,基于地形曲面曲率和坡度的洋中脊构造解译方法是有效且可行的,其结果为洋中脊构造样式解译提供重要参考。但是相比之下,50 m分辨率下慢速扩张洋中脊的应用效果要明显好于快速扩张洋中脊,这可能与不同扩张速率的断层尺寸及发育规律有关。

It is of great significance to understand the evolution of geological structures of mid-ocean ridges with the surface morphology of the ocean floor near a mid-ocean ridge. Because of thin sedimentary cover, the structure and distribution of ocean floors directly reflect the lithospheric characters of oceanic crusts and the expansion of mid-ocean ridges. Multi-beam echo sounding technology plays a vital role in ocean explorations because it is one of important methods in marine scientific research, benthonic resource exploitation, and ocean engineering construction. The multi-beam terrain data provide a more convenient way to study ocean floor structures near mid-ocean ridges. In this paper, we use different expansion rates of ridge near 50 m precision of multi-beam terrain data, based on the multi-scale space analysis method, using different sliding windows and automatic threshold recognition and extraction of terrain near mid-ocean ridges to the maximum, minimum curvatures and slopes, and the structures of the mid-ocean ridges according to this interpretation. For mid-ocean ridges in the Atlantic and eastern Pacific Oceans, two quantitative analysis of the test results show that, based on the terrain surface curvatures and slopes of the mid-ocean ridge, the structural interpretation method is effective and feasible and the results for the mid-ocean ridge tectonic style interpretations provide an important reference. However, in comparison, application to slow spreading of mid-ocean ridges with 50 m accuracy is better than that of the rapid spreading of mid-ocean ridges, which may be related to the size of faults and the development law of different rifting rates.