Lava Tubes at Shallow Depth
Many theoretical studies concerning lava tubes focus on the thermal disturbances generated on the earth surface. Recently a solution was suggested, where a lava tube located at a great depth h in the soil, where the ratio between h to the major axis of the ellipse a is higher than 10. However, lava tubes more frequently are located at shallower depths. In this work we focus our attention to the stationary thermal field generated by an elliptical lava tube at constant temperature located at shallow depths. Moreover, we take into account the effect of the heat lost from the earth surface by air convention. The problem is approached by COMSOL Multiphysics.