Open AccessLong‐term record of CO 2 degassing along Mt. Etna's flanks and its relationship with magma dynamics and eastern flank instability
Author(s) -
Federico Cinzia,
Camarda Marco,
De Gregorio Sofia,
Gurrieri Sergio
Publication year - 2011
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2011gc003601
Subject(s) - geology , induced seismicity , volcano , magma , flank , seismology , intrusion , fault (geology) , rift zone , rift , geochemistry , petrology , tectonics , sociology , anthropology
A record of soil CO 2 flux data on the lower flanks of Mt. Etna, measured from 1989 to 2008, is discussed in the framework of multidisciplinary observations, including seismicity, ground deformations, and flank instability. A huge increase in soil CO 2 fluxes appears to be related to the dynamics of magma ascent in the upper portions of the volcano (0–3 km) and the intrusion of dykes along the southern rift, as mainly observed before the 1991–93 eruption. Even after the 1991–93 eruption, the recharge of the shallow/central reservoir was accompanied by a long‐term increase in soil CO 2 degassing mainly in the southwestern area. The 2001 eruption marked dramatic changes in the areal distribution of seismicity, the deformation pattern, and the soil CO 2 degassing. Indeed, while the soil CO 2 degassing showed background values in the southwestern area, it progressively increased in the eastern sector and along the Pernicana fault. This has been related to the marked sliding of the eastern flank since the 2002–03 eruption and the associated seismicity. This study provides evidence that the extent of soil CO 2 degassing on the lower flanks of Mt. Etna is controlled by (1) the volume of involved magma, (2) the intrusion of dykes in the upper parts of the volcano, and (3) fault movement and seismicity. This implies that different degassing structures must be monitored simultaneously when attempting to understand the behavior of the volcano as a whole.