Abstract
Tilt and strainmeter data collected in the Friuli seismic area between 1977 and 1985 have been analyzed to study the stress-strain field and/or the elastic parameter variations in the area after the strong 1976 seismic event.
We concentrated on three different frequency bands, respectively linked with the tidal waves, the seasonal effect and the secular one. The results from the first two bands point at an increase of the local rigidity modulus.
Relevant stresses induced by the seasonal groundwater level variations have been found, thus supporting the hypothesis that they can act as triggering effects. The secular trend reveals significant tectonic stress modifications. It appears that the post-seismic tectonic stresses faded during 1981–1983, and were followed by a new loading phase.
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On leave from the Institute of Geodesy and Geophysics of the Chinese Academy of Sciences. Ph. D. student at the Institute of Geodesy and Geophysics, Trieste University.
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Mao, W.J., Santero, P. & Zadro, M. Long- and middle-term behaviour of the tilt and strain variations in the decade following the 1976 friuli earthquake in NE Italy. PAGEOPH 132, 653–677 (1990). https://doi.org/10.1007/BF00876812
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DOI: https://doi.org/10.1007/BF00876812