The first ultra-high resolution Digital Terrain Model of the shallow-water sector around Lipari Island (Aeolian Islands, Italy)

Alessandro Bosman Alessandro Bosman,Filippo Muccini Filippo Muccini,Marco Anzidei Marco Anzidei,Cosmo Carmisciano Cosmo Carmisciano,Francesco Latino Chiocci Francesco Latino Chiocci,Daniele Casalbore Daniele Casalbore

doi:10.4401/ag-6746

Abstract

Very high resolution bathymetric map obtained through multibeam echo-sounders data are crucial to generate accurate Digital Terrain Models from which the morphological setting of active volcanic areas can be analyzed in detail. Here we show and discuss the main results from the first multibeam bathymetric survey performed in shallow-waters around the island of Lipari, the largest and the most densely populated of the Aeolian Islands (southern Italy). Data have been collected in the depth range of 0.1-150 m and complete the already existent high-resolution multibeam bathymetry realized between 100 and 1300 m water depth. The new ultra-high resolution bathymetric maps at 0.1-0.5 m provide new insights on the shallow seafloor of Lipari, allowing to detail a large spectrum of volcanic, erosive-depositional and anthropic features. Moreover, the presented data allow outlining the recent morphological evolution of the shallow coastal sector of this active volcanic island, indicating the presence of potential geo-hazard factors in shallow waters.

Highlights

Since the beginning of 1930s, single-beam echosounders were used to produce early remote-sensing based bathymetric maps
The main reason for such improvements in seafloor mapping is that multibeam echo-sounders (MBES), with respect to single beam echo-sounders, are equipped with hundreds of narrow adjacent beams arranged in a fan-like swath of typically 90 to 170 degrees across, providing very high resolution measurements up to few centimeters
The aim of the paper is to present the technical details of the survey and briefly depict the first results arising from the ultra-high resolution multibeam bathymetry, evidencing possible implications on recent volcanism, tectonics and coastal hazard at Lipari Island

Summary

Introduction

Since the beginning of 1930s, single-beam echosounders were used to produce early remote-sensing based bathymetric maps. The main reason for such improvements in seafloor mapping is that MBES, with respect to single beam echo-sounders, are equipped with hundreds of narrow adjacent beams arranged in a fan-like swath of typically 90 to 170 degrees across, providing very high resolution measurements up to few centimeters. MBES mapping benefited from GNSS satellite data to precisely positioning the vessel during surveys, supported by on board integrated motion-sensors used to estimate and correct continuously the vessel motion (roll, pitch and yaw) during the survey. The GPS satellites of the Global Navigation Satellite System (GNSS) provides the precise position of the vessel and the MBES sensor during navigation even up to a few cm of accuracy, collecting the soundings data in the WGS84 geodetic reference system. Nowadays MBES technique represents the most significant advance in the field of seafloor and continental water basins mapping, becoming a crucial tool for marine geomorphological studies [Locat and Lee 2002, Morgan et al 2003, Esposito et al 2006 and references therein, Anzidei et al 2008, Bosman et al 2009, Blondel 2012, Romagnoli et al 2012, Romagnoli et al 2013a]

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Conclusion