Made with a new satellite data processing procedure. The authors: «The volcano is constantly changing, it will be useful for scientists but also for guides and tourists»
A study has outlined the new face of Etna, the largest active volcano in Europe, in continuous evolution and transformation. The research, fruit of the work of Ingv scientists Gaetana Ganci, Annalisa Cappello and Marco Neri, led to the elaboration of a new topographic map of the volcano published in the specialized magazine Remote Sensing
. The map was produced thanks to a new procedure fusion of satellite data elaborated by Tania Ganci. The study was supported by the Ingv Dynamic Planet project.
The changes
«Very active volcanoes such as Etna», says the volcanologist of theIngv of Catania Marco Neri, «significantly modify their topographic surface with great frequency, especially in zone summits, i.e. those most exposed to the covering of new lava flows, erosions and collapses. Also for this reason it is very important to always produce new topographic maps of the portions of the territory that are constantly changing, also to update the three-dimensional models of the terrain on which to simulate the propagation of lava flows”. Neri adds: «For example, the lava flow active since the first days of December 2022 and emerging from an eruptive fissure that opened at the northern base of the South-East crater, albeit modestly fed, is already modifying the morphology and altitude of those places ».
Hi-tech instruments
A continuous change, in progress. Etna is an evolving model monitored and studied from a variety of points of view and with the most sophisticated hi-tech methods and tools. The largest open-air scientific laboratory on the globe, where innovative and cutting-edge experiments are carried out. The new mapping has considerable scientific, theoretical and practical relevance, and will have it in terms of daily life on the volcano, also for the tourist guides whose experience thousands of visitors and travelers rely on every year.
The new map
What are the key aspects of the new map? The scientists explain it in their article: «It is a new automatic procedure for updating digital topographic data from multi-source satellite images, which consists in the production of digital surface models (DSM) from high resolution optical satellite images , followed by a merger context-aware which takes advantage of the complementary features of multi-source DSM. This minimizes errors and artifacts due to occlusions (for example, the presence of clouds, snow or ash plumes) in the source images, resulting in improved accuracy and quality compared to those that are not merged» .
The analyzed period, methods and tools
The study authors state that “the procedure has been tested to produce the 2021 digital topography of theEtna, whose summit area is constantly evolving and shows the new peak of 3,347 meters on the north rim of the South-East crater. We also use the DSM 2021 to measure the volcanic deposits located in the last five years, finding about 120 million cubic meters, with an average annual volume of about 24 million cubic meters in accordance with the large eruptive rates recorded on Etna starting from seventies. The flexibility and modularity of the procedure presented”, they continue, “make it easily exportable to other environmental contexts, allowing a rapid and frequent reconstruction of topographic surfaces even in extreme environments”.
The life of Etna
According to scholars «today on the summit of this volcano there are four active craters: that of the South-East, formed during the 1971 eruption, was the most active summit crater in recent decades. 2021 has been a crucial year in the recent transformation of Etna: the summit area has in fact undergone an unprecedented morphological change. More than 50 eruptive events occurred from January to July, characterized by the emission of sustained eruptive columns and lava flows, combined with several collapses followed by pyroclastic avalanches.
January 3, 2023 (change January 3, 2023 | 10:01 am)
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