Geoscience Reference
In-Depth Information
volcano monitoring, for the modeling of tephra dispersal, and for remote measurements of
volcanic gas fluxes for which the plume transport speed is needed.
7. Other applications of transportable radars
Beyond their main use to measure near-source eruptive parameters, compact Doppler radars
can be utilized for a number of other applications in volcano monitoring. The identification of
erupting vents using range gating and the tracking of rockfalls are illustrated in this section;
possible investigations on fallout are discussed in the concluding section.
7.1 Discrimination of active vents
The summit areas of active volcanoes have complex and evolving morphologies, often
comprising multiple craters, themselves possibly nesting several vents, all potentially active
simultaneously with various dynamics. The relatively good spatial resolution (tens of
meters) of dedicated ground-based radars often allows the spatial discrimination of the
surface activity and, in particular, the identification of the eruptive vents. This information
is obviously very useful in volcano monitoring to locate the activity in real-time. Note that
large wavelength signals, such as that used by VOLDORAD (L band) can penetrate through
dense ash-laden plumes or lava fountains and give information on possible activity
occurring in craters behind.
Fig. 16. Spatial discrimination of active craters of Etna using range gating (VOLDORAD 2B).
Simultaneous tephra emissions of Bocca Nuova and new SE Crater at Etna on July 9 2011 are
discriminated using echoes in range gates at 3735 m and 3135 m respectively (Radar data:
OPGC-INGV; Photo courtesy: Tom Pfeiffer, www.volcanodiscovery.com).
