Composition and textural tephra characteristics of the 1970 eruption at Deception Island (Antarctica): Implications for volcanic hazards.

Deception Island is the most active volcano in the South Shetland Islands with more than 20 explosive eruptions registered over the past centuries. The latest event (1970) was severely violent with a volcanic explosivity index (VEI) of 3. The column height reached 10 km, the estimated bulk eruptive volume was > 0.1 km3 and tephra fallout was reported as far as in King George Island (> 150 km distance). In this work, we perform a compositional and textural analysis of the 1970 tephra layers found at Livingston Island¿s glaciers. Results obtained are compared to the in situ pyroclastic deposits of the active vents during the eruption. The objective is to establish a correlation between the eruptive phases occurred during the 1970 event and the physicochemical features observed in the tephra deposits. This will be used the onset of future studies of tephra layers found in glaciers and marine/lacustrine sediment cores outside the island, improving our capacity to reconstruct the eruptive dynamics of past eruptions. This is fundamental to: (i) determine the size and explosiveness of past eruptions; (ii) assess the extent of their related hazards; (iii) complete the eruptive record; and (iv) consequently, perform accurate hazard assessments at the island.