Submarine and Subaerial Morphological Changes Associated with the 2014 Eruption at Stromboli Island

Daniele Casalbore,Alessandro Bosman,Claudia Romagnoli,Federico Di Traglia,Nicola Casagli,Francesco Latino Chiocci

doi:10.3390/rs13112043

Abstract

Stromboli is an active insular volcano located in the Southern Tyrrhenian Sea and its recent volcanic activity is mostly confined within the Sciara del Fuoco (SdF, hereafter), a 2-km wide subaerial–submarine collapse scar, which morphologically dominates the NW flank of the edifice. In August-November 2014, an effusive eruption occurred along the steep SdF slope, with multiple lava flows reaching the sea. The integration of multisensor remote sensing data, including lidar, photogrammetric, bathymetric surveys coupled with SAR amplitude images collected before and after the 2014 eruption enabled to reconstruct the dynamics of the lava flows through the main morphological changes of the whole SdF slope. Well-defined and steep-sided ridges were created by lava flows during the early stages of the eruption, when effusion rates were high, favoring the penetration into the sea of lava flows as coherent bodies. Differently, fan-shaped features were emplaced during the declining stage of the eruption or in relation to lava overflows and associated gravel flows, suggesting the prevalence of volcaniclastic breccias with respect to coherent lava flows. The estimated volume of eruptive products emplaced on the SdF slope during the 2014 eruption, accounts for about 3.7 × 106 m3, 18% of which is in the submarine setting. This figure is different with respect to the previous 2007 eruption at Stromboli, when a large lava submarine delta formed. This discrepancy can be mainly related to the different elevation of the main vents feeding lava flows during the 2007 eruption (around 400 m) and the 2014 eruption (around 650 m). Besides slope accretion, instability processes were detected both in the subaerial and submarine SdF slope. Submarine slope failure mobilized at least 6 × 105 m3 of volcaniclastic material, representing the largest instability event detected since the 2007 lava delta emplacement.

Highlights

IntroductionStromboli is the north-easternmost island of the Aeolian Archipelago in the Southern
A2 and A3: while the former one corresponds to a well-defined and steep-sided ridge (R2 in Figure 6b), a more irregular, fan-shaped feature is present in the area A3. This difference in morphology could be ascribed to the different amount of coherent lava flows with respect to chaotic breccias, using as reference the scuba observations made for the 2007 lava delta, where this kind of products were recognized [25]
The integration of repeated bathymetric, lidar and photogrammetric surveys along with SAR amplitude images was a fundament tool to understand the morphological evolution of the SdF slope induced by the 2014 eruption and its pre-eruptive stage, which was characterized by two months of intense Strombolian activity

Summary

Introduction

Stromboli is the north-easternmost island of the Aeolian Archipelago in the Southern. Stromboli and Panarea volcanic edifices are part of a 45 km long volcanic area developed along a NE-SW regional extensional fault system (Figure 1b) above the thinned continental crust of the Calabrian Arc [1,2]. The evolution of Stromboli island occurred in the last 85 ka (apart from the older Strombolicchio edifice dated at about 200 ka) and can be divided in six main growth stages, with magmas ranging from calc-alkaline to potassic series, typical. 2021, 13, 2043 be divided in six main growth stages, with magmas ranging from calc-alkaline to potassic of an arc-volcanic setting, whose formation can be related tocan thebe subduction thesubducIonian series, typical of an arc-volcanic setting, whose formation related toof the crustofbeneath the Calabrian. Remote Sens. 2021, 13, 2043 be divided in six main growth stages, with magmas ranging from calc-alkaline to potassic of an arc-volcanic setting, whose formation can be related tocan thebe subduction thesubducIonian series, typical of an arc-volcanic setting, whose formation related toof the crustofbeneath the Calabrian

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Conclusion