Thermal sensitivity analysis of emplacement of the magma chamber in Los Humeros caldera, Puebla, Mexico

Abstract

We present results of our simulation study of the effects of the depth (top of the magma chamber at 5-10 km) and volume (1000-1400 km3) of the primary heat source beneath the Los Humeros caldera. The thermal gradient in the vicinity of the magma chamber calculated from the temperature excess (difference between the simulated and the initial temperatures prior to emplacement of the magma) is more sensitive to its depth of intrusion than to its volume. This relationship was quantified from multiple linear regression equations. The temperature excess at 2-3 km depth due to the emplacement of magma and its conductive cooling is also more dependent on the chamber depth than on its volume. Therefore, in the study of calderas, volcanoes, and geothermal fields, constraining the chamber depth is more important than its volume. Similarly, comparison of the thermal regime inferred along vertical and horizontal profiles shows the importance of solving the thermal transport equations in three dimensions instead of one or two dimensions.