Diffuse Degassing Baseline in Paricutin volcano and Michoacan-Guanajuato monogenetic volcanic field, Mexico

Diffuse CO2 emissions are a powerful tool for detecting changes in volcanic activity, temporary degassing variations, and delimiting spatial structures of fluid rise given permeability contrasts. In this work, base degassing values of CO2 flux and total fluxes are reported for the first time in the Michoac acute accent an Guanajuato monogenetic volcanic field, as well as its temporal evolution, comparing data from 2006, 2009, 2011, 2012, and until 2020 in 30 measurement stations that have the Paricutin volcano as the central zone. Likewise, diffuse degassing alignments are reported in the directions SW-NE and (SW-W)-(NE-E) in the northeast part of the Tancitaro volcano. This area coincides with the high density of earthquakes during the 2020 and 2021 swarms and with the region where La Escondida is located, whose inhabitants reported perceiving the swarm. Additionally, diffuse degassing results of CO2 are shown for the first time in Paricutin volcano, the youngest cone in the field, for three field works done in 2011, 2012, and 2020. Fluxes of CO2 remain in the range of 0.01-226.12 +/- 10 g m(-2) d(-1). The study includes generation of distribution maps and the discussion of main diffuse degassing structures at Paricutin volcano in the directions N-S to SW-NE. Furthermore, for both zones, the entire field and the Paricutin volcano, three degassing groups (A -low, B -medium and C-high) were obtained, delimiting the anomalous degassing group in volcanic field as all CO2 fluxes with values equal or greater than group C of the Paricutin volcano (2020) in the range of 88-190 +/- 10 g m(- 2) d(-1). With this work, it is shown that the continuous measurements of diffuse emissions should be a priority of the comprehensive monitoring of the volcanic field, being able to detect in advance: (a) anomalous emissions or areas of high permeability that could favor the rise of fluids and melts; and (b) changes in the emission rates.

Automated summary

This study reports the CO2 diffuse emissions in the Michoacán and Guanajuato monogenetic volcanic field in Mexico for the first time. The temporal evolution and spatial structures of the emissions are analyzed based on data from 2006 to 2020. The study highlights the importance of continuous monitoring of diffuse emissions in detecting changes in volcanic activity and anomalous emissions, and emphasizes the need to prioritize this monitoring for comprehensive volcano surveillance.