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| Titel |
The small but clear gravity signal above the natural cave “Grotta Gigante” (Trieste, Italy) |
| VerfasserIn |
Carla Braitenberg, Daniele Sampietro, David Zuliani, Alfio Barbagallo, Paolo Fabris, Julius Fabbri, Lorenzo Rossi, Ahmed Handi Mansi |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250100410
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| Publikation (Nr.) |
 EGU/EGU2014-16374.pdf |
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| Zusammenfassung |
| Gravity observations are a powerful means for detecting underground mass changes. The Italian and Slovenian
Karst has a number of explored caves, several are also touristic due to their size (e.g. Grotta Gigante in Italy;
Skocjianske Jame and Postojnska Jama in Slovenia). Just a few years ago another big cave was discovered by
chance close to Trieste when drilling a tunnel for a motor-highway, which shows that more caves are expected to be
discovered in coming years. We have acquired the gravity field above the Grotta Gigante cave, a cave roughly 100
m high and 200 m long with a traditional spring-gravity meter (Lacoste&Romberg) and height measurements made
with GPS and total station. The GPS was made with two different teams and processing algorithms, to cross-check
accuracy and error estimate. Some stations had to be surveyed with a classical instrument due to the vegetation
which concealed the satellite positioning signal. Here we present the results of the positioning acquisitions and
the gravity field. The cave produces a signal of 1.5 mGal, with a clear elongated concentric symmetry. The survey
shows that a systematic coverage of the Karst would have the benefit to recover the position of all of the greater
existing caves. This will have a large impact on civil and environmental purposes, since it will for example allow
to plan the urban development at a safety distance from subsurface caves. |
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