Costa Recta beach, Deception Island, West Antarctica: a retreated scarp of a submarine fault?

Abstract

Deception Island (South Shetlands, Antarctica) is one of the most active volcanoes in Antarctica, having erupted recently in 1967Antarctica, having erupted recently in , 1969Antarctica, having erupted recently in and 1970, damaging scientific stations on the island. It is also seismically very active. The island has attracted the attention of many researchers as it constitutes an undisturbed natural laboratory to study seismo-volcanic events and how they affect landscape modelling and evolution. One of the most remarkable geological and geomorphological features on Deception Island is the linearity of its easternmost coastal landform, the origin of which remains unknown. Some answers, based on presence of strike-slip fault or on the ice cap and beach geomorphological dynamics, have been reported in the literature. Our new work provides several indications of the existence of a dip-slip submarine fault, parallel to the coast (NNW-SSE), which suggests a tectonic origin for this morphological feature. Uplifted marine terraces, incision of a fluvial network over the ice cap, normal faulting parallel to the coast in the north and south rock heads bounding the beach and sharp shelf-break with rather constant slope, constitute some of this evidence. Terrace uplift and fluvial channel incision decreasing southward from Macaroni Point, indicates possible tilt movement across this inferred fault plane.

Determination of volumetric variations and coastal changes due to historical volcanic eruptions using historical maps and remote-sensing at Deception Island (West-Antarctica)

“…Holohan et al (2005) described fracture sets associated with caldera collapse, pointing out that ring and radial faults control the brittle deformation, and probably determine the location of later eruptions associated with the caldera rim. The outer shoreline of the island exhibits a complex evolution, with high lava cliffs on the northern and western shorelines, and a linear coastline due to the action of submarine faulting to the east of the island (Fernández-Ibáñez et al, 2005).…”

The 3D Attenuation Structure of Deception Island (Antarctica)

“…1) is considered as a laboratory for Volcano Geophysics due to the large number of multidisciplinary studies focused both on imaging its surface and deep structures and on monitoring its volcanic activity. Scientists have widely studied the origin and morphology of Deception Island, bringing forward general and local models (e.g., Martí et al 1996Martí et al , 2013Smellie et al 2002;Fernández-Ibáñez et al 2005;Maestro et al 2007; Barclay et al 2009;Melo et al 2012;Torrecillas et al 2012Torrecillas et al , 2013. The study of the seismic activity of the volcano is probably the most active and productive research line, as reported by Tejedo et al (2014).…”

Characterization of fracture systems using precise array locations of earthquake multiplets: An example at Deception Island volcano, Antarctica

“…Kirkwood, the phreatomagmatic eruptions produced by these fissures and the alignments of submarine cones inside the caldera. The third system is NNW–SSE oriented and its main evidence is in the Costa Recta alignment [ Fernández‐Ibáñez et al , 2005]. Other alignments can be observed in the Mt.…”