Article,
Thermal monitoring of hydrothermal activity by permanent infrared automatic stations: Results obtained at Solfatara di Pozzuoli, Campi Flegrei (Italy)
Journal of Geophysical Research, 112 (B12): B12206+ (Dec 28, 2007)
DOI: 10.1029/2007JB005140
Abstract
A permanent automatic infrared (IR) station was installed at Solfatara
crater, the most active zone of Campi Flegrei caldera. After a positive
in situ calibration of the IR camera, we analyze 2175 thermal IR
images of the same scene from 2004 to 2007. The scene includes a
portion of the steam heated hot soils of Solfatara. The experiment
was initiated to detect and quantify temperature changes of the shallow
thermal structure of a quiescent volcano such as Solfatara over long
periods. Ambient temperature is the main parameter affecting IR temperatures,
while air humidity and rain control image quality. A geometric correction
of the images was necessary to remove the effects of slow movement
of the camera. After a suitable correction the images give a reliable
and detailed picture of the temperature changes, over the period
October 2004 to January 2007, which suggests that origin of the changes
were linked to anthropogenic activity, vegetation growth, and the
increase of the flux of hydrothermal fluids in the area of the hottest
fumaroles. Two positive temperature anomalies were registered after
the occurrence of two seismic swarms which affected the hydrothermal
system of Solfatara in October 2005 and October 2006. It is worth
noting that these signs were detected in a system characterized by
a low level of activity with respect to systems affected by real
volcanic crisis where more spectacular results will be expected.
Results of the experiment show that this kind of monitoring system
can be a suitable tool for volcanic surveillance.
