Geospatial warning systems
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Project > Methodologies > Ground-based heat and CO2 flux measurements
Heat Flux Measurements
The systematic measuring of the thermal energy released by active volcanoes
in quiescent periods can constitute a powerful monitoring tool for volcanic
activity. This is based on the relatively high thermal energy outputs estimated
for many volcanic-geothermal systems (Fig. 24) and their potentially high variability
as a result of magmatic and tectonic processes.
Based on soil diffuse degassing structures (DDS) and soil temperature gradient
measurements, a thermal energy of 58 MW was estimated to be discharged from
soil diffuse emission at the hydrothermal crater area of Nisyros. The heat fluxes
of individual DDS are typically tens or hundreds of W /m2.
Fig. 24 Measurements of diffuse CO2-fluxes and LS heat flux
sensor measurements. Osservatorio Vesuviano Napoli (OVNI)
Technical specification of LS heat flux sensor and computer modeling
The LS sensor is a disk (thickness 0.7 cm, diameter 5 cm) composed of two steel
layers (0.2 cm thick) with an inter-bedded 0.3 cm thick epoxy layer (Fig. 25).
The thermal conductivity of the sensor on the whole is 0.5 W / (K m).
Fig. 25 LS heat flux sensor measurement on the floor of Stefanos
hydrothermal crater (Nisyros). Osservatorio Vesuviano Napoli (OVNI)
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