Carbon dioxide Earth degassing and seismogenesis in central and southern Italy

Abstract

We present the first regional map of CO 2 Earth degassing from a large area (most of central and south Italy) derived from the carbon of deep provenance dissolved in the main springs of the region. The investigation shows that a globally significant amount of deeply derived CO 2 (10% of the estimated global CO 2 emitted from subaerial volcanoes) is released by two large areas located in western Italy. The anomalous flux of CO 2 suddenly disappears in the Apennine in correspondence to a narrow band where most of seismicity concentrates. Here, at depth, the gas accumulates in crustal traps generating CO 2 overpressurized reservoirs which induce seismicity.