Morphosedimentary analysis of the Sloggett submarine canyon and its regional implications. NW Scotia Sea.

FEDERICO DAMIÁN ESTEBAN; JUAN PABLO ORMAZABAL; MARÍA EMILIA BRAVO; JOSÉ ISOLA; GRAZIELLA BOZZANO; CÉSAR ARTUNDUAGA; FERMIN IGNACIO PALMA; SEBASTIÁN PRINCIPI; DANIELA SPOLTORE; ALEJANDRO ALBERTO TASSONE

Atenas

Conferencia; Regional Conference on Geomorphology; 2019

INTERNATIONAL ASSOCIATION OF GEOMORPHOLOGISTS

The south Argentine Continental Margin (ACM) is incised by deep and large canyons that belong to the canyon´s system of Tierra del Fuego. The Sloggett Canyon, located in northwestern Scotia Sea, is the longest with a total lenght of 142 km along the thalweg, cutting the continental platform, slope and abyssal plain. In this work we present a morphosedimentary and structural analysis of the canyon revealed from recently data obtained on board the R/V Austral in the YTEC-GTGM0 cruise in September 2017. It consists in the first complete very-high resolution imaging (up to 20 m) of the canyon from its upper part down to its distalmost reach. Swath bathimetry with the echosounder EM-122 and sub-bottom profiler with Parasound P70 were used for distinguish morphologies made by processes of erosion, transport and deposition. The head is affected by tributaries channels that range in size, direction and depth and act as a conduit for gravity flows and turbidity currents. They have a wide expression in the east flank regarding the western flank where predominate wall slumping, gullies and scar. The canyon was studied considering three parts of the thalweg, where the direction changes abruptly two times from NW-SE to SW-NE in an angle of approximately 90 degrees. This was associated with the NW-SE lineaments of the West Scotia Ridge, where could be acted as a path for the canyon and the Beagle Channel Fault System that has a W-E direction affecting the slope. Additionally, along-processes related to the strong oceanic currents from contourites drifts and erode the margin to form contourites terraces along canyon depth. The canyon has a connection with the Sloggett Bay (10 Km notrth) and can be considered as a continuation of the Sloggett Continental Tectonic Lineament.