Morphology and distribution of monogenetic volcanoes in Los Tuxtlas Volcanic Field, Veracruz, Mexico: implications for hazard assessment

We find that volcanic hazards vary across the historically active Los Tuxtlas volcanic field (LTVF), with large scoria cones, and likely larger magnitude and intensity eruptions, concentrated in a NW–SE trending band and maars distributed at lower elevations. As eruptive processes vary in systematic ways across the LTVF that reflect the structure and topography of this volcanic field, spatial variations in eruption characteristics we identify are a valuable guide to future volcanic hazard assessments. The LTVF is located in a tropical climate near the coast of the Gulf of Mexico, isolated from the Trans-Mexican Volcanic Belt. We have identified 350 recent monogenetic edifices, mainly scoria cones and maars, in this approximately 100 × 50 km and mostly poorly accessible volcanic field. We compare morphologic traits among scoria cones and maars in the central and distal areas of the volcanic field using statistical analyses of volcano morphometric parameters obtained from Lidar images. Predictions, using the Kriging function, indicate areas most prone to future eruptions and likely morphologic characteristics of future volcanoes, which correlate with eruptive processes. Larger-sized scoria cones are preferentially located close to fault systems that define the center line of the NW–SE elongate volcanic field and likely are produced by eruptions with violent Strombolian phases. Some of these cones emplaced close to the NW-trending fault systems are associated with low-viscosity lava flows that reach > 10 km off the axis of the volcanic field. These are inferred to have particularly high effusion rates. Phreatomagmatic eruptions occur preferentially in the SW section of the volcanic field, a region which currently hosts a shallow ground water table near the contact with the Tertiary Veracruz basin sediment fill.