mercoledì 11 maggio 2016

Short-Term Earthquake Forecast with the Seismic Sequence Hierarchization Method

All strong earthquakes are preceded by branching structures having different durations whose development scheme is partly largely predictable because it follows a well organized and recognizable pattern. By using a seismic sequence hierarchization method, this study graphically explains the preparation process of an earthquake, called “branching structure”. In addition, criteria apt to distinguish the structures that will produce shocks of average magnitude from strong earthquakes’ will be defined. Based on the temporal oscillations of the magnitude values, we explain the procedure for identifying the developmental stages that characterize the energy accumulation stage of the branching structure, in order to early detect the energy release stage’s trigger point and obtain information on how it will develop over time. The study identifies also some pre-signals (trigger points) of various magnitudes in the energy release stage, which allows us to early predict the foreshocks and mainshock time position. The method we developed constitutes a truly innovative approach for the earthquake forecasting analysis, which dramatically differs from those developed so far, as it considers the structure of the seismic sequence not only as a magnitude values’ oscillation, but also as a sequence of developmental stages that may begin much earlier.

Riga G. & Balocchi P., 2016

Paper
Riga G. & Balocchi P. (2016); Short-Term Earthquake Forecast with the Seismic Sequence Hierarchization Method. Open Journal of Earthquake Research, 5, 79-96. doi: 10.4236/ojer.2016.52006.

sabato 7 maggio 2016

Terremoto del Friuli del 6 Maggio 1976 - Friuli earthquake on May 6, 1976



Il terremoto del 6 maggio 1976 è stato preceduto da un foreshock di primo ordine di Mb 5.2. La fase di rilascio di energia è classificata come “Progressive earthquakes”. La fase di accumulo di energia che segue il mainshock di Ms 6.5, è composta da aftershocks di tipo “Flah earthquakes” con schemi di attivazione di tipo Falling wedge Pattern o Rectangle Pattern (Horizontal e ascending).

The earthquake on May 6, 1976 was preceded by a foreshock of the first order of Mb 5.2. The energy release phase is classified as "Progressive earthquakes". The energy accumulation phase that follows the mainshock of Ms 6.5, is composed of "flah earthquakes"aftershocks, with type of activation: Falling Wedge Pattern or Rectangle Pattern (Horizontal and ascending).

Reference
Riga G. & Balocchi P. (2016); Seismic Sequence Structure and Earthquakes Triggering Patterns. Open Journal of Earthquake Research, 5, pp. 20-34.
NCEDC (2014), Northern California Earthquake Data Center. UC Berkeley Seismological Laboratory. Dataset. doi:10.7932/NCEDC --> ANSS Composite Earthquake Catalog.