Abstract
AbstractTristan da Cunha is assumed to be the youngest subaerial expression of the Walvis Ridge hot spot. Based on new hydroacoustic data, we propose that the most recent hot spot volcanic activity occurs west of the island. We surveyed relatively young intraplate volcanic fields and scattered, probably monogenetic, submarine volcanoes with multibeam echosounders and sub-bottom profilers. Structural and zonal GIS analysis of bathymetric and backscatter results, based on habitat mapping algorithms to discriminate seafloor features, revealed numerous previously-unknown volcanic structures. South of Tristan da Cunha, we discovered two large seamounts. One of them, Isolde Seamount, is most likely the source of a 2004 submarine eruption known from a pumice stranding event and seismological analysis. An oceanic core complex, identified at the intersection of the Tristan da Cunha Transform and Fracture Zone System with the Mid-Atlantic Ridge, might indicate reduced magma supply and, therefore, weak plume-ridge interaction at present times.
Funder
Deutsche Forschungsgemeinschaft
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry
Reference70 articles.
1. Clague, D. & Dalrymple, G. B. The Hawaiian-Emperor volcanic chain: part I. Geologic evolution. US Geol. Surv. Prof. Pap. 1350, 5–54 (1987).
2. Hagen, R. A., Baker, N. A., Naar, D. F. & Hey, R. N. A SeaMARC II survey of recent submarine volcanism near Easter Island. Mar. Geophys. Res. 12, 297 (1990).
3. Fretzdorff, S., Haase, K. M. & Garbe-Schönberg, C. D. Petrogenesis of lavas from the Umu volcanic field in the young hotspot region west of Easter Island, southeastern Pacific. Lithos 38, 23–40 (1996).
4. Devey, C. W. et al. Giving birth to hotspot volcanoes: distribution and composition of young seamounts from the seafloor near Tahiti and Pitcairn islands. Geology 31, 395–398 (2003).
5. Sobolev, A. V., Hofmann, A. W., Sobolev, S. V. & Nikogosian, I. K. An olivine-free mantle source of Hawaiian shield basalts. Nature 434, 590–597 (2005).
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