We
report data from a radon survey conducted at Villarrica volcano.
Measurements have been obtained at selected sites by E-PERM®electretsand
two automatic stations utilizing DOSEman detectors (SARAD Gmbh). Mean
values for Villarrica are 1600 (±1150) Bq/m3are
similar to values recorded at Cerro Negro and Arenal in Central
America. Moderately higher emissions, at measurement sites, were
recorded on the NNW sector of the volcano and the summit, ranging from
1800 to 2400 Bq/m3.
These measurements indicate that this area could potentially be a zone
of flank weakness. In addition, the highest radon activities, up to
4600 Bq/m3,
were measured at a station located near the intersection of the
Liquiñe-Ofqui Fault Zone with the Gastre Fault Zone.
To
date, the Villarrica radon measurements reported here are, together
with those collected at Galeras (Colombia), the sole radon data
reported from South American volcanoes. This research may contribute to
improving future geochemical monitoring and volcano surveillance.