Present work studies the influence of the regional topography on the hydrothermal fluid flow pattern in the subsurface of a volcanic complex. We discuss how the advective transfer of heat from a magmatic source is controlled by the regional topography for different values of the averaged permeability. For this purpose, we use a 2-D numerical model of coupled mass and heat transport and new data sets acquired at Ticsani and Ubinas, two andesitic volcanoes in Southern Peru which have typical topography, justifying this approach. A remarkable feature of these hydrothermal systems is their remote position not centered on the top of the edifice. It is evidenced by numerous hot springs located in more than 10 km distance from the top of each edifice. Upwelling of thermal water is also inferred from a positive self-potential anomaly at the summit of the both volcanoes, and by ground temperature...

Se realiza la aplicación del método magnetotelúrico (MT) en el Complejo Volcánico Ampato-Sabancaya (CVAS), volcán Hualca Hualca (VHH) y alrededores. El procesamiento de estos datos e inversión unidimensional (1D) y tridimensional (3D), han permitido obtener modelos de resistividad 1D y 3D, que permitieron identificar tres zonas conductivas y dos zonas resistivas a diferentes niveles de profundidad: 1) El conductor superficial C1 (1 a10 Ω.m), ubicado a ~1.0 km de profundidad, asociado al sistema hidrotermal que comparten el CVAS y VHH. 2) El conductor intermedio C2, está compuesto por los sub-conductores C2.1, C2.2 y C2.3. De ellos, el C2.1 (1 a 4 Ω.m), se ubica bajo el volcán Sabancaya, entre ~2 y 8 km de profundidad que por sus características, se trataría de la cámara magmática superficial del volcán Sabancaya; C2.2 (< 1.2 Ω.m), ubicada por debajo del volcán Ampato,...

Páginas 1140-1143.

4 páginas.