The spatiotemporal evolution of monogenetic scoria cones in the Paricutin-Tancítaro region, Mexico: Results from a Morpho-chronological analysis and its consequences on the distributed volcanic hazard

Abstract

The Paricutin-Tancítaro region (PTR) within the Michoacán-Guanajuato monogenetic Volcanic Field (MGVF) is characterized by a large stratovolcano, Tancítaro enclosed in a dense distribution of monogenetic volcanoes, mainly scoria cones, that includes the well-known Paricutin. The succession of seismic swarms beginning 54 years after the birth of Paricutin in 1943 represents a challenge for apprising the region's volcanic and seismic hazards. In this work, we introduce a novel methodology to assess the spatiotemporal evolution of the monogenetic scoria cones and the distributed volcanic hazards. We first performed a morpho-chronometric analysis of 171 scoria cones to estimate their relative ages, which revealed an increasing trend in the rate of monogenetic eruptions over the last 120 kyr, especially in the last 20 kyr, with a current mean waiting interval between monogenetic eruptions of only 120 yr. In a second step, we estimate the spatiotemporal evolution of monogenetic volcanic activity in PTR using a Voronoi tessellation to represent the spatial density distribution of scoria cone emplacement through time to detect dynamic shifts in volcanic activity locations in the region. This approach thus reveals spatial dynamic patterns in the rates of monogenetic eruptions over time. Subsequently, a Poisson process is assumed to estimate the spatially distributed cone-forming eruption probabilities based on the morpho-chronometrically analyzed cones. Remarkably, a high spatial correlation was found between the areas with the highest probabilities and the location of the recent seismic swarms recorded in the PTR.