Correlation between tectonic CO2 Earth degassing and seismicity is revealed by a 10-year record in the Apennines, Italy

Deep CO₂ emissions characterize many nonvolcanic, seismically active regions worldwide, and the involvement of deep CO₂ in the earthquake cycle is now generally recognized. However, no long-time records of such emissions have been published, and the temporal relations between earthquake occurrence and tectonic CO₂ release remain enigmatic. Here, we report a 10-year record (2009-2018) of tectonic CO₂ flux in the Apennines (Italy) during intense seismicity. The gas emission correlates with the evolution of the seismic sequences: Peaks in the deep CO₂ flux are observed in periods of high seismicity and decays as the energy and number of earthquakes decrease. We propose that the evolution of seismicity is modulated by the ascent of CO₂ accumulated in crustal reservoirs and originating from the melting of subducted carbonates. This large-scale, continuous process of CO₂ production favors the formation of overpressurized CO₂-rich reservoirs potentially able to trigger earthquakes at crustal depth.

Porosity, bulk density and CaCO3 content of travertines. A new dataset from Rapolano, Canino and Tivoli travertines (Italy)

The dataset presented in this article is used in the Quaternary Science Review research article "Evaluating the geogenic CO₂ flux from geothermal areas by analysing Quaternary travertine masses. New data from western Central Italy and review of previous CO₂ flux data" [1]. The present data article reports the physical properties and new compositional data of 86 travertine samples from Rapolano, Canino and Tivoli travertine deposits (Italy). The dataset include the following parameters: mass, volume, porosity, bulk density, CaCO₃ content and insoluble fraction. The dataset is integrated with the photographic documentation of the sampling areas, the location and the stratigraphic position of each sample.