Publication Date:
2019-03-26
Description:
Uplift and subsidence alternate throughout the life cycle of a volcano mirroring magma accumulation,
migration and/or gas pressurization, and magma cooling or depressurization, respectively. The
unusual occurrence of coeval inflation and deflation is difficult to reconcile with the recharging or cooling
of a single magma chamber, or hydrological processes. Here we show a persistent flank uplift and central
subsidence at Colli Albani volcano near Rome (Italy), by mapping about 20 years of deformation by InSAR
data. The magmatic helium signature increases in correspondence with N-S faults along the western slope
of Colli Albani, which are therefore interpreted as deep-seated structures directly or indirectly connected
with an underlying magma reservoir. Deformation modeling shows that these faults are pathways for fresh
magma intrusion, whereas a residual magma is cooling below the deflating caldera. Therefore, magma
recharge at depth is controlled by major faults along which the vents of the most recent activity (〈200 ka
ago) concentrate in the western side of the volcano and not by the caldera structures. We demonstrate that
the Colli Albani magmatic system is slowly rejuvenating, posing a volcanic threat for Rome.
Description:
Published
Description:
1484-1498
Description:
4V. Processi pre-eruttivi
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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