Fracturation pattern and morphostructure of the Deception Island volcano, South Shetland Islands, Antarctica

Abstract The Antarctic active volcano Deception Island has been the subject of extensive geological, geophysical and geomorphological research, including studies on its volcanic history. Since the initial geoscientific research, many authors have included lineament traces (in general considered as faults) in the maps, schemes and figures accompanying their publications. In the last 3 decades, several papers have contributed to improving our understanding of the volcano’s structure. In some cases, the fracture network was identified, measured and analysed and general models of the island’s structure were developed. However, the various authors have not always used consistent methodologies for lineament mapping, presenting significant disparities in the obtained results. This paper analyses previously interpreted lineaments and integrates existing geophysical, geological and morphostructural evidence, along with original field data, to establish a morphostructural model through a coherence and uncertainty analysis. The lineaments determined on Deception Island exhibit three preferred directions: NE-SW, ESE-WSW and SSE-NNW. However, the fractures measured in the field generally show a radial distribution, although there are two preferred directions: NNE-SSW and SE-NW. A synthetic map of Deception Island’s lineaments is presented, indicating which are the lineaments that should be considered tectonic-volcanic fractures among the other existing lineaments.