Infrared remote sensing of Earth degassing - Ground study

• Main Authors: P. Strobl, H. Gemperlein, H. Pfanz, V. Tank
• Format: Article
• Language: English
• Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 2005-06-01
• Series: Annals of Geophysics
• Subjects: mofettes; thermography; remote sensing; swarm earthquakes; CO2-gas emission
• Online Access: http://www.annalsofgeophysics.eu/index.php/annals/article/view/3193

Geodynamical processes e.g., volcanoes, often cause degassing at the Earth surface. The geogas emanates via
 mineral springs, water mofettes, or dry mofettes. It is assumed that the emerging gas influences the temperature
 of the spring or mofette water, respectively and the surface temperature of the soil at and around the dry gas
 vents. This causes a thermal anomaly in comparison to the close vicinity. Under specific conditions this effect
 should be extractable from remotely acquired infrared images allowing detection, mapping and monitoring of
 gas vents/springs within large areas and short times. This article describes preparatory investigations for which
 emanating Earth gas was simulated by leading compressed air into the ground and releasing it in some depth via
 a metal lance. The thermal effect at the surface was observed from a nearby thermovision camera in summer and
 winter under varying meteorological conditions. A procedure was developed to reliably identify gas release areas
 within the recorded thermal images of the scene. The investigations are aiming at studies to be performed
 later in the Western Bohemia (Czech Republic) earthquake swarm region where especially CO2 of magmatic origin
 from European SubContinental Mantle (ESCM) emanates.