Aeromagnetic anomalies and structure of the Iztaccíhuatl- Popocatépetl volcanic region in Central Mexico

Abstract

Popocatépetl volcano is characterized by a high amplitude dipolar anomaly that is normally polarized and centered on the summit cone. The anomaly shows the effects of topographic relief and of major fault zones. Similar characteristics are docu- mented over the Iztaccíhuatl volcanic complex, where a large composite dipolar anomaly is correlated with topography and with effects of deeper-seated source bodies. The dipolar anomaly is normally polarized over the summit elevations, with superimposed lower amplitude anomalies over the volcano flanks. An aeromagnetic survey over the adjacent volcanic and sedimentary terrains to the east and south of the Iztaccíhuatl-Popocatépetl complex also reflect the surface and deep geological features, with high- amplitude, high-frequency anomalies over the volcanic units and small volcanoes and low-amplitude, long-wavelength anomalies over the volcano-sedimentary deposits. The aeromagnetic survey illustrates the potential of aerogeophysical methods in studying volcanic structures over abrupt topography and undergoing active eruptive phases.