Seafloor mapping using high-resolution multibeam backscatter: The Palinuro Seamount (Eastern Tyrrhenian Sea)

Sara Innangi,Salvatore Passaro,Renato Tonielli,Girolamo Milano,Guido Ventura,Stella Tamburrino

doi:10.1080/17445647.2015.1071719

Sara Innangi, Salvatore Passaro + Show 4 more

Open Access

https://doi.org/10.1080/17445647.2015.1071719

Copy DOI

Abstract

ABSTRACTWe present a seafloor map of the summit of Palinuro Seamount, an E–W elongated volcanic ridge located in the Eastern Tyrrhenian Sea. The seafloor was mapped using multibeam backscatter and seafloor samples collected between 80 and 1000 m below the sea level. The high-resolution imaging of the Palinuro seafloor was obtained by merging a Digital Terrain Model with a 2.5 m-sized grid and a backscatter mosaic with 2.5 m pixel. The resulting 1:20,000 scale map includes six main facies recognized based on their backscatter properties. These six facies reflect different lithologies. The Palinuro seafloor map represents a useful tool for morphological and geological studies of the Palinuro volcanic ridge.

Highlights

Recent improvements in sonar technology provide a new tool for the exploration of the seafloor
The final mosaic was exported as a geo-referenced TIFF image with a 2.5 m pixel size and imaged using a grey scale in which the higher backscatter values correspond to darker areas (Figure 3B)
The recognized six main acoustic facies are: (1) BedRock (BR); this facies is characterized by a hard bottom and high backscatter values; (2) Biodetritic sand (BS); this consists of organic detritus produced from the erosion of coralligenous concretions

Summary

Introduction

Recent improvements in sonar technology provide a new tool for the exploration of the seafloor. Backscatter measurements are carried out for identifying and mapping gas hydrate seafloor morphologies in the Eastern Mediterranean (Lykousis et al, 2009; Woodside, David, Frantzis, & Hooker, 2006), Tyrrhenian Sea (Rovere et al, 2014), Black Sea (Klaucke et al, 2006), Nile delta (Duprè, Woodside, Klaucke, Mascle, & Foucher, 2010). They have been used in specific studies aimed at the detection of active mud-flows (Chen et al, 2014), hemipelagic dust, carbonate crusts (Zitter, Huguen, & Woodside, 2005), and sampling of flares in the water column (Law et al, 2010). Mapping of Palinuro Seamount (PS) is crucial for (1) volcalonological studies, (2) submarine mining exploration (poly-metallic nodules at shallow depth), and (3) the evaluation of the hazard related to possible flank instability processes

Geological setting

Data and methods

Results and discussion

Conclusions

Disclosure statement