RECENT SEISMIC SWARMS IN THE PARICUTIN REGION: WHAT TYPES OF ERUPTIONS CAN BE EXPECTED IN THE FUTURE BASED ON THE VOLCANIC GEOLOGY?
Over the past 30 years, eight distinct seismic swarms were recorded between in the Paricutin region and interpreted to reflect magma movement at depths between 16 and 8 km (Legrand et al., 2023). Whether they are precursors to a new eruption remains uncertain.
Knowledge of the volcanic geology of the Michoacán-Guanajuato Volcanic Field (MGVF) is fragmentary, but available radiocarbon dates allow to infer that another eruption is likely to occur during the next 200 years. Furthermore, geologic information provides clues on possible eruption scenarios and hazards, which is of importance for implementing disaster mitigation strategies.
Recent studies in the Paricutin region (e.g., Larrea et al., 2019) confirm that the most common and voluminous products are lava flows of andesitic composition, while basalts and rhyolites are subordinate. Tephra fallout from Strombolian activity is quite frequent, but limited in volume. Monogenetic scoria cones and their associated lava flows with small volumes (<2 km3) are the most abundant type of volcano. In addition, mid-sized shields and domes (5-15 km3) dominate the landscape (Chevrel et al., 2016) while phreatomagmatic volcanoes are rare.
The smaller monogenetic vents in the MGVF occur either isolated or form small clusters. The identification of small clusters comprising several monogenetic volcanoes that erupted in a sequence of geologically short time intervals (hundreds to few thousands of years) in small areas (e.g., Zacapu; Reyes-Guzmán et al., 2021) opens several questions in the context of the seismic swarms near Paricutin: Are the Holocene clusters still “active” and is a new eruption likely to occur within their surroundings? How long are such clusters “active”? Is it possible that the prehistoric Astillero/Pedregal (Larrea et al., 2019) and historic eruptions of Paricutin (1943-1952) represent the beginning of clusters and should a new eruption in their proximity be expected in the future? In order to address these questions, several clusters are currently under study in order to shed more light on the conditions that allow several magma sources to be formed and then tapped in close temporal and spatial proximity to each other and produce such small “flare-ups”.
References:
Chevrel, M.O., Guilbaud, M.N., Siebe, C. (2016). The AD 1250 effusive eruption of El Metate shield volcano (Michoacán, Mexico): Magma source, crustal storage, eruptive dynamics, and lava rheology. Bull. Volcanol. 78 (4): 32.
Larrea, P., Siebe, C., Juárez-Arriaga, E., Salinas, S., Ibarra, H., Böhnel, H. (2019). The ~AD 500-700 (Late Classic) El Astillero and El Pedregal volcanoes (Michoacán, Mexico): a new monogenetic cluster in the making? Bull. Volcanol. 81(10): 59.
Legrand, D., Perton, M., Macías, J.L., Siebe, C., et al. (2023). Repeated seismic swarms near Paricutin volcano: Precursors to the birth of a new monogenetic volcano in the Michoacán-Guanajuato volcanic field, México? Bull. Volcanol. 85: 30.
Reyes-Guzmán, N., Siebe, C., Chevrel, O.M., Pereira, G., (2021). Late Holocene Malpaís de Zacapu (Michoacán, Mexico) andesitic lava flows: Rheology and eruption properties based on LiDAR image. Bull. Volcanol. 83 (4): 28.