Morphological and geological features of Drake Passage, Antarctica, from a new digital bathymetric model

The Drake Passage is an oceanic gateway of about 850 km width located between South America and the Antarctic Peninsula that connects the southeastern Pacific Ocean with the southwestern Atlantic Ocean. It is an important gateway for mantle flow, oceanographic water masses, and migrations of biota. This sector developed within the framework of the geodynamic evolution of the Scotia Arc, including continental fragmentation processes and oceanic crust creation, since the oblique divergence of the South American plate to the north and the Antarctic plate to the south started in the Eocene. As a consequence of its complex tectonic evolution and subsequent submarine processes, as sedimentary infill and erosion mainly controlled by bottom currents and active tectonics, this region shows a varied physiography. We present a detailed map of the bathymetry and geological setting of the Drake Passage that is mainly founded on a new compilation of precise multibeam bathymetric data obtained on 120 cruises between 1992 and 2015, resulting in a new Digital Bathymetric Model with 200 × 200 m cell spacing. The map covers an area of 1,465,000 km2 between parallels 52°S and 63°S and meridians 70°W and 50°W at scale 1:1,600,000 allowing the identification of the main seafloor features. In addition, the map includes useful geological information related to magnetism, seismicity and tectonics. This work constitutes an international cooperative effort and is part of the International Bathymetric Chart of the Southern Ocean project, under the Scientific Committee on Antarctic Research umbrella.德雷克海峡（Drake Passage）是位于南美洲与南极半岛之间的大洋通道，宽度约850千米，连接东南太平洋与西南大西洋。其是地幔流、海洋水团运移以及生物群迁徙的重要通道。自南美板块向北、南极板块向南发生始新世斜向张裂以来，该区域便处于斯科舍海岭（Scotia Arc）地球动力学演化框架之中，经历了大陆裂解与洋壳形成等过程。受复杂构造演化与后续海底作用（主要由底流与活动构造控制的沉积充填与侵蚀过程）影响，该区域呈现出多样的地形地貌特征。本研究提供了德雷克海峡高精度水深与地质背景图件，其编制基础为1992年至2015年间120次科考航次获取的精准多波束水深数据，最终构建了像元间距为200×200米的全新数字水深模型（Digital Bathymetric Model）。该图件比例尺为1:1600000，覆盖范围为南纬52°至63°、西经70°至50°，总面积达146.5万平方千米，可清晰识别主要海底地貌特征。此外，该图件还包含与磁法、地震活动及构造相关的实用地质信息。本研究为国际合作成果，隶属于南极研究科学委员会（Scientific Committee on Antarctic Research, SCAR）框架下的南大洋国际水深图（International Bathymetric Chart of the Southern Ocean, IBCSO）项目。