Seismic Profiles from Port Foster, Deception Island (Antarctica)
|Author(s)||Gómez-Ballesteros María1, Gómez De Paz Ricardo1, Álvarez-Valero Antonio2, Kereszturi Gabor3|
|Affiliation(s)||1 : Instituto Español de Oceanografía, C/Corazón de María 8, 28002 Madrid, Spain
2 : Departamento de Geología, Universidad de Salamanca, 37008 Salamanca, Spain
3 : Volcanic Risk Solutions, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
|Keyword(s)||TOPAS, Seismic Profiles, Port Foster, South Shetland Islands, Deception Island, Antarctica|
Deception Island (South Shetland Islands, Antarctica) consist of a horseshoe-shaped volcanic edifice, which evolution is marked by the formation of a collapse caldera. It is the most active volcano in the South Shetland archipelago with more than 20 eruptions in the past two centuries. In order to improve our knowledge about Deception Island, a total of 12 parametric seismic profiles were obtained from the island’s interior bay (Port Foster) during the 2017/2018 Spanish Antarctic Campaign and the Antarctic GALILEO-IHM cruise aboard the R/V Hespérides (2017 / 2018) with a hull-mounted TOPAS PS 018 high-resolution parametric sounder designed for sub-bottom profiling with very high spatial resolution in water depths from less than 20 meters to full ocean depth.
|Utilisation||Data are published without any warranty, express or implied. The user assumes all risk arising from his/her use of data. Data are intended to be research-quality and include estimates of data quality and accuracy, but it is possible that these estimates or the data themselves contain errors. It is the sole responsibility of the user to assess if the data are appropriate for his/her use, and to interpret the data, data quality, and data accuracy accordingly. Authors welcome users to ask questions and report problems.|
|Acknowledgements||This research was supported by the Spanish Government POSVOLDEC (CTM2016-79617-P)(AEI/FEDER, UE) project and the GALIEO-IHM Program. We thank the BIO Hespérides oceanographic cruise and the Marine Hydrographic Institute, for their constant help and logistic support, without which this research would not have been possible.|
Parametric seismic profiles were obtained with a hull-mounted TOPAS PS 018 high-resolution parametric sounder designed for sub-bottom profiling with very high spatial resolution in water depths from less than 20 meters to full ocean depth. The +80% relative bandwidth, low frequency signal is generated in the water column by non-linear interaction between two high frequency signals (centered symmetrically around 18 kHz). The seismic profiles obtained were recorded working in high-penetration mode, by transmission of a Chirp wave (LFM), trying at all times not to interfere with the EM122 multibeam echosounder signal. Normal transmission frequencies vary from 2.0 kHz for the initial and 5 kHz for the final, with a pulse length of 10 ms, and transmitted at a 1,500 ms internal mode trigger interval. The record length was 400 ms at a sampling rate of 16.0 Hz. The deconvolution and initial 2 kHz filtering (HP filter) of the signal have always been applied in this Chirp mode. The TVG ramps normally used during the acquisition have been 0.78 d/ms between the bottom and 5.4 ms depth, 0.77 d/ms between 5.4 and 25.9 ms, and 0.14 d/ms after 35.6 ms.