北吕宋海槽深海滑坡沉积及其分布特征

Deepwater landslide deposition and distribution characteristics in the northern Luzon Trough

通过浅地层剖面和多波束地形资料的精细解释,在北吕宋海槽中部发现了一个规模约500 km2,平均厚20多米的海底滑坡沉积。通过对该滑坡体的物源及其沉积环境分析,将整个滑坡体沉积分为末端区和前缘区两个部分。从滑坡体与周围地层的叠置关系及火山弧喷发的历史来看,初步认为该海底滑坡是地震造成的。该滑坡体的发现对深化深水滑坡体的认识具有重要作用。

High-resolution bathymetry and subbottom profile data have been acquired in the northern Luzon Trough,a landslide extended on an area of 500 km2,more than 20 m thick has been found in the middle trough.According to the analysis of landslide source and its sedimentary environment,the landslide is divided into two parts： an end area and a front area.From the relationship between the landslide area and the surrounding stratum and the history of the volcano eruption,it is suggested that the submarine landslide is triggered by the earthquake.Most submarine landslides occur in the depth range of 2 000 m,while the average depth of the study area is more than 3 000 m,thus the discovery of the submarine landslide is significant in deepening the research of the deepwater landslide.