Geoelectric survey of Fundáo Island, Rio de Janeiro - Brasil

Fundäo Island, located in Guanabara Bay, and part of Rio de Janeiro city, Brasil, is the result of an artificial embankment of a former small archipelago, built in the early 1950's. The aim of this work is to identify, by means of a geoelectric survey, the cores of the original islands. Normally, deep structures near the seacoast cannot be detected through geoelectric measurements. This is due to the presence of salt water in sediments. However. in the case of Fundäo Island, the high conductivity segments have a lenticular form and correspond to the embankments.'This circumstance allows the detection of deep layers and resistive nuclei. Results of vertical electric soundings using Schlumberger method with a maximum aperture (AB/2) of 100 m at the UFRJ campus (Fundäo Island) show that the resistive nuclei are strongly correlated to the original islands of the archipelago. Data were processed by means of RESIX-IP (1993) software.