SVILUPPO DI METODI DI ANALISI DI SERIE STORICHE FOR L'ANALISI DI TERREMOTI E IL LORO CARATTERE  TSUNAMIGENICO

Responsabili di progetto

Luciano Telesca, Ashutosh Chamoli

Accordo

INDIA - CSIR-expired - Council of Scientific and Industrial Research

Bando

CNR/CSIR 2012-2014

Dipartimento

ICT

Area tematica

Ingegneria, ICT e tecnologie per l'energia e i trasporti

Stato del progetto

Nuovo

Proposta di ricerca

Great earthquakes in the sea have often generated the devastating tsunami waves. Tsunami is a very complex natural phenomenon to understand, and its complexity lies in all its stages, i.e., generation, propagation, runup and inundation. The recent devasting and giant tsunamis which occurred in the in Japan (11 March 2011) and Sunda trench (26 December 2004) have opened the Pandora's box in the field of studies devoted to the subduction zone. Apart from the precise alert/warning system, it has altered entire scientific community in the world. There are several methods available to detect tsunamis and its near-field and far-field impact, but these are time consuming and difficult to apply in the practical and real situations. One approach which is widely and generally used by the early warning systems/centers for the detection of tsunamigenic and non-tsunamigenic earthquakes is by receiving the information from the DART buoys deployed in the deep oceans. The tsunami has to reach these buoys, then transfer of tsunami water level information to the early warning centers, processing this data and issuing warning takes time. Another accurate approach which is used by several researchers in this field is modeling of all the stages of tsunami propagation and simulation of tsunami wave heights and runup heights at the far-field locations before the arrival of the tsunami. But this method needs precise magnitude estimation and fault parameters, i.e., strike (orientation of the fault), dip, rake, slip magnitude and focal depth. This method is appropriate to understand tsunami behaviour and to estimate far-field (impact) effects, but not suitable to issue early warnings. The time of the arrival of tsunami at the coastal areas nearby epicentral region is less compared to the time taken for the simulation process.
In the framework of the present project, we intend to develop diagnostic rules for distinguishing the tsunamigenic and non-tsunamigenic earthquakes by means of the integration of several methods based on the (i) correlation content, (ii) informational content and (iii) frequency content of seismograms. The correlation content will be investigated by means of the recent and robust methodologies like the detrended fluctuation analysis, the multifractal detrended fluctuation analysis, the singular spectrum analysis, which allow to estimate dynamical parameters of a time series, like scaling exponents, dynamical crossovers, persistence degrees, power content that are important for a deep understanding of the dynamical mechanisms that govern such time series. The informational content will be investigated by means of the Fisher information measure, the Shannon entropy, and the Fisher-Shannon information plane method, able to estimate the degree of organization and order of the system and to furnish a 2-dimensional visual discrimination of the two types of earthquakes. The frequency content will be analysed by means of the power spectral density and wavelets. Such methods have been already applied by both teams in several scientific fields, and their application to seismograms could lead to their better dynamical characterization. The methods will be applied to different tsunamigenic and non-tsunamigenic earthquakes considering only first few minutes of the P-wave train which could help in early warnings.
The expected results and deliverables of the project are:  1) Tools for the robust processing of tsnunamigenic seismograms.  2) Intermediate and final reports on the performed activities and obtained results.  3) Papers and abstracts submitted to international journals and conferences respectively with the acknowledgement of the CNR-CSIR bilateral agreement.  4) Webpage dedicated to the project (description, teams, data and results).  5) Seminars jointly organized in Italy and Spain focused on the topics of the project.

Obiettivi della ricerca

The general objectives are:1) To start the co-operation between the involved institutions;2) To share data and methodologies for a better understanding of earthquake and tsunami  processes;3) To acquire co-operation procedures and sharing of data and human resources, to be exploited for a future continuation of joint research/education activities. The specific objectives are:1) to develop diagnostic rules for the discrimination between tsunamigenic and non-tsnunamigenic earthquakes;2) to organize testing procedures and define confidence bands for the developed methods by using simulated series generated by means of different surrogate methods (random shuffling, AAFT);3) to set up a framework for the assessment of tsunami hazard, by means of all the data collected and the results obtained; 4) to disseminate preliminary and final results of the project in international conferences, publications, and in a project-oriented internet website;5) to foster young researchers of both the involved institutions.

Ultimo aggiornamento: 04/07/2025