Registro de resúmenes

Reunión Anual UGM 2023


SE13-7 Plática invitada

 Resumen número: 0123  |  Resumen aceptado  
Presentación oral

Título:

DENSE NODAL SENSORS PROBE THE UNDERGROUND OF LIPARI VOLCANIC ISLAND (AEOLIAN ISLANDS, ITALY)

Autores:

1 Francesca Di Luccio ← Ponente
Istituto Nazionale di Geofisica e Vulcanologia
francesca.diluccio@ingv.it

2 Marco Calò
UNAM
calo@igeofisica.unam.mx

3 Patricia Persaud
University of Arizona
ppersaud@arizona.edu

4 Guido Ventura
INGV
guido.ventura@ingv.it

5 Luigi Cucci
INGV
luigi.cucci@ingv.it

6 Alessandra Esposito
INGV
alessandra.esposito@ingv.it

7 Mimmo Palano
INGV
mimmo.palano@ingv.it

Sesión:

SE13 Métodos de inversión y estimación de las incertidumbres aplicados a datos geofísicos Sesión especial

Resumen:

We applied Ambient Noise Tomography to continuous data recorded by the 2018 dense seismic array at Lipari. The active volcanic island extends for ~37 km2 in the southern Tyrrhenian Sea at the intersection of the WNW-ESE Sisifo-Alicudi fault system to the west, and the NNW-SSE Aeolian-Tindari-Letojanni fault system to southeast, in the framework of the subduction of the Ionian plate under the Calabrian Arc. At Lipari, volcanic rocks and deeper intrusions fill a ∼3-km-deep structural depression. The volcanic activity developed between 267 ka and historical times (1220 CE). Proceeded from west to east, the early products were basaltic to andesitic lava flows and scoria deposits, while the final stages consist of the extrusion of rhyolitic domes, explosive eruptions including sub-Plinian events, and the emplacement of pumice cones and obsidian lava flows.

Although geophysical studies have imaged the structure of the Aeolian Islands at the regional scale, Lipari’s structure remained poorly understood due to the lack of a dense seismic network on the island. In 2018, for the first time, 48 compact seismic instruments were installed providing continuous data for about one month that are used in this study to produce the first 3D model of the volcano down to ∼2.5-3 km depth. Since most of Lipari’s seismicity occurs offshore and is not evenly distributed, ambient noise tomography is the most suitable technique to obtain high resolution images of the underground. 3D imaging depicts a complex shallow VS structure revealing the close spatial and temporal relationship among different volcanic, structural, and hydrothermal features. This complexity is due to the coexistence of a) partly superimposed volcanoes with different structures, for example, a central polygenic edifice (Mt. S. Angelo), small-scale scoria and pumice cones (Timponi, Mt. Pilato), and domes (Mt. Guardia), b) erupted products with extremely variable compositions, for example, early basalts and basaltic andesites and later andesites, dacites and rhyolites, c) areas of intense hydrothermal activity, and d) zones affected (or not) by faults. High shear wave velocities are found in western Lipari, where active hydrothermal vents and N-S faults are mapped. Low wave speeds are revealed beneath southern and north-eastern Lipari, where more recent (<24 ka) volcanic activity developed along N-S dike-like structures that are aligned with rhyolitic vents. We propose that such dikes may represent the preferred pathways of future volcanic eruptions. This conclusion suggests the importance to continuously monitor variations of geophysical and geochemical observables over time. Results of the 2018 seismic experiment demonstrate that dense nodal arrays can provide high-quality datasets useful for studying the velocity structure of volcanically active and densely populated islands. Such rapid low-cost deployments further allow for the time-lapse monitoring of volcanic and hydrothermal systems for near real-time hazard assessment. In the next future a multidisciplinary approach will be applied to study in detail the lithospheric structure, the pattern of crustal deformation and the geochemical signature of the Central-Aeolian Islands.





Reunión Anual UGM 2023
29 de Octubre al 3 de Noviembre
Puerto Vallarta, Jalisco, México