LAUSR

Abstract The bathymetry and geomorphological characteristics of Udaeta Lake are herein presented. This lake is located in the central-eastern portion of Isla Grande de Tierra del Fuego and it fills a structural depression originated along a section of the Magallanes-Fagnano Fault System. Based on a bathymetric survey, the depth data of the lake allowed for describing it by means of several morphometric parameters. Udaeta Lake has an area of 159 ha, a perimeter of 4.911 m, and a maximum depth of 25.9 m. Two sub-basins can be recognized within the Udaeta Lake: a large-size (ca. 953 × 1012 m), deep (25.9 m), and asymmetric basin located to the east and a smaller (175 × 317 m), shallower (17 m) sub-basin to the west. The Udaeta Lake is characterized as a geomorphologic feature of the Magallanes Fagnano Fault System, i.e. as an active pull-apart basin. In this paper, we provide information that may help to the geomorphological characterization and interpretation of the neotectonic genesis of Udaeta Lake.