Regional-scale airborne electromagnetic surveying of the Yucatan karst aquifer (Mexico): geological and hydrogeological interpretation

作者：Gondwe Bibi R N^*; Ottowitz David; Supper Robert; Motschka Klaus; Merediz Alonso Gonzalo; Bauer Gottwein Peter

来源：Hydrogeology Journal, 2012, 20(7): 1407-1425.

DOI：10.1007/s10040-012-0877-8

• Remote sensing
• Frequency-domain EM
• Karst
• Yucatan
• Mexico

Geometry and connectivity of high-permeability zones determine groundwater flow in karst aquifers. Efficient management of karst aquifers requires regional mapping of preferential flow paths. Remote-sensing technology provides tools to efficiently map the subsurface at such scales. Multi-spectral remote sensing imagery, shuttle radar topography data and frequency-domain airborne electromagnetic (AEM) survey data were used to map karst-aquifer structure on the Yucatan Peninsula, Mexico. Anomalous AEM responses correlated with topographic features and anomalous spectral reflectance of the terrain. One known preferential flow path, the Holbox fracture zone, showed lower bulk electrical resistivity than its surroundings in the AEM surveys. Anomalous structures delineated inland were sealed above by a low-resistivity layer (resistivity: 1-5 Omega m, thickness: 5-6 m). This layer was interpreted as ejecta from the Chicxulub impact (Cretaceous/Paleogene boundary), based on similar resistivity signatures found in borehole logs. Due to limited sensitivity of the AEM survey, the subsurface configuration beneath the low-resistivity layer could not be unambiguously determined. AEM measurements combined with remote-sensing data analysis provide a potentially powerful multi-scale methodology for structural mapping in karst aquifers on the Yucatan Peninsula and beyond.

• 出版日期2012-11