Fecha: 20 abril 2026
Autor Ckelar: Amiel NietoTorres
Otros autores: Ana Lillian Martin Del Pozzo
Revista científica: Journal of Volcanology and Geothermal Research
Abstract
Chichinautzin volcano was formed along a WSW-ENE-trending fissure that extends 900 m long, located at the watershed of two basins. This caused the lava flows to spread out radially, but primarily towards the south and north, reaching what is now the southernmost inhabited part of Mexico City. The eruptive activity of the Chichinautzin volcano began explosively with the emission of pyroclasts and rapidly turned effusive, characterized by the emission of fluid lava and the formation of large lava tubes. These pahoehoe and aa lava flows formed a wide lava-shield covering 52 km2. The Chichinautzin lava flows (and flow units) were mapped in more than 80 field campaigns. Through field analysis for each of the flow units and the processing of a high-resolution digital elevation model, as well as the analysis of SPOT, Maxar, Sentinel 2 and LANDSAT 8 satellite images, drone images and twelve 1:5000 scale aerial photographs, the different structures associated with each flow were identified such as tumuli, levees, subsidence craters, inflation cracks, channels, lava tubes and hornitos. The thickness, width, and length of eachof the lava flow units were measured in order to estimate effusion rates, volume and eruption duration. We found significant variations in the effusion rate, which are related to the volume of emitted lava and the characteristics of the lava flows at each eruptive stage. The effusion rate is high at the beginning of the effusive phase, >100 m3/s, and becomes progressively lower towards the end of the eruption, <1 m3/s. The total volume of lava emitted, calculated using two methods, range between 3.3 and 3.6 km3. The duration of the eruption was estimated to be between 7 and 11 years. Lavas vary from basaltic andesites (53%) to andesites (57%) with time. The fluid lava erupted at the beginning of the eruption, form the distal lava flows, while the upper lava flows were shorter. When comparing the characteristics of the Chichinautzin volcano eruption with other recent monogenetic and fissural eruptions around the world, we found significant contrasts, which highlights the unique nature of this eruption such as the large volume of lava emitted and the long duration of the eruption. The fissure activity of an islandic nature is also exceptional in this part of México. The volcano’s location at the watershed of two basins and the proximity to populated areas suggests the type of risk that México City and the Morelos urban area face.