Antarctic Science



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


FERMÍN FERNÁNDEZ-IBÁÑEZ a1c1, RAUL PÉREZ-LÓPEZ a2, JOSÉ J. MARTÍNEZ-DÍAZ a3, CARLOS PAREDES a4, JORGE L. GINER-ROBLES a3, ALBERTO T. CASELLI a5 and JESÚS M. IBÁÑEZ a6
a1 Dpto. de Geodinámica, F. de Ciencias, Campus Fuentenueva s/n, Universidad de Granada, 18002, Granada, Spain
a2 Dpto. de C.C. Ambientales y Rec. Naturales, Facultad de Farmacia, Universidad San Pablo-CEU, 28688 Boadilla del Monte, Madrid, Spain
a3 Dpto. de Geodinámica, F. C.C. Geológicas, Universidad Complutense de Madrid, 28040, Madrid, Spain
a4 Dpto. de Matemática Aplicada y Métodos Informáticos, E.T.S. Ingenieros de Minas, Universidad Politécnica de Madrid 28003, Madrid, Spain
a5 Dpto. Cs. Geológicas, Fac. Cs. Ex. y Nat., Universidad de Buenos Aires, Argentina, Ciudad Universitaria, Pab.2, 1428, Buenos Aires, Argentina
a6 Instituto Andaluz de Geofísica, Campus de Cartuja s/n, Universidad de Granada, 18071 Granada, Spain

Article author query
fernández-ibáñez f   [PubMed][Google Scholar] 
pérez-lópez r   [PubMed][Google Scholar] 
martínez-díaz jj   [PubMed][Google Scholar] 
paredes c   [PubMed][Google Scholar] 
giner-robles jl   [PubMed][Google Scholar] 
caselli at   [PubMed][Google Scholar] 
ibáñez jm   [PubMed][Google Scholar] 

Abstract

Deception Island (South Shetlands, Antarctica) is one of the most active volcanoes in Antarctica, having erupted recently in 1967, 1969 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.

(Received August 3 2004)
(Accepted March 29 2005)


Key Words: active tectonics; fault escarpment; straight coast; tectonic geomorphology; uplifted terraces.

Correspondence:
c1 fferiba@ugr.es


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