Geomorphological and statistical characterization of submarine volcanic centers of Pantelleria Volcano (Italy)
Presented by Dr. Marilena CALARCO on 23 Sep 2013 from 17:15 to 19:15
Type: Poster presentation
Session: Poster session
Track: Poster presentations
Pantelleria Volcano is well known for its subaerial activity and as the type locality for pantellerite rocks. However, the last eruption (1891) was submarine occurring 5 km W-NW of Pantelleria harbor. Recent high-resolution mapping offshore Pantelleria volcano has revealed a complex seafloor morphology characterized by volcanic features mostly represented by lava flows, volcanic outcrop remnants and several volcanic centers. These centers, located both on the insular shelf and along the flanks (down to 850 m bsl), are mainly concentrated NW of the island. A geo-morphological analysis of Pantelleria submarine cones was performed. The cones along the flanks were found to range in height up to about 360 m, have basal widths of 0.2-2.3 km, slopes from 21° to 42°, and an average aspect ratio of 0.15. Their volumes vary from 7x10-4 to 0.37 km3. The volcanic centers exhibit a well-preserved morphology and were classified as pointed, elongated, or composite. They are mainly characterized by a single or multi-peak profile rather than displaying craters or flat-topped summits. It is worth to note that some cones show small-scale summit collapses with a newly reconstructed dome within the scar. Pre-collapse morphologies of these cones were reconstructed and dimensions and volumes were estimated to better understand their growth and failures. The statistical analysis showed a good correlation between cone diameter and height suggesting that the cones evolved self-similarly, in response of analogous constructional and erosional processes. Slope stability was also evaluated and indicated that the cones affected by sector collapses would have been stable in static conditions. It should be noted that the cones affected by collapses result to have had the peak at shallower depths. Therefore, a relationship between summit depth, volcanic activity, and collapse was inferred. Overall, this study provides for the first time key information on the nature of Pantelleria submarine cones, which represent a significant contribution to the growth of the volcano, and gives new insights to better understand associated instability phenomena.
Geomorphological and statistical analyses of submarine volcanic cones offshore Pantelleria Island suggest a possible mechanism for their sector collape.