Development and application of advanced statistical methods to characterize GPS and gravimetric continuous signals measured in a high geodinamically active area of Azerbaijan

Project leaders

Luciano Telesca, Gulam Babayev

Agreement

AZERBAIJAN - ANAS-not in force - Azerbaijan National Academy of Sciences

Call

CNR/ANAS 2014-2015

Department

Earth system science and environmental technologies

Thematic area

Earth system science and environmental technologies

Status of the project

New

Research proposal

Azerbaijan is caught in the active continent collision of the Arabian plate with Eurasia (Mckenzie, 1972; Sengor et al., 1985; Philip et al., 1989). Plate tectonic reconstructions provide only broad constraints on the timing of the initial collision of the Arabian Plate with Eurasia of between 10 - 30 Ma BP (e.g., Robertson, 2000; Allen et al., 2004), and indicate that the rate of northward motion of Arabia relative to Eurasia has remained more or less constant at about 20 mm/yr since collision began (McQuarrie et al., 2003; Reilinger et al., 2006). These reconstructions imply that Arabia has progressed from 200 - 600 km "into" space formerly occupied by Eurasian continental lithosphere. This "intrusion" of Arabia into Eurasia continues to be accommodated by lithospheric shortening on roughly E-W striking thrust faults and lateral displacement of lithosphere out of the collision zone along right-lateral strike-slip faults (McKenzie, 1972; Sengor et al., 1985; Jackson, 1992; Kadirov, 2004; Reilinger et al., 2006b). These regional tectonic processes give rise to earthquakes that have devastated the Caucasus region throughout recorded history.

In order to monitor the complex geodynamics of Azerbaijan, the research group leaded by Prof. F. Kadirov has installed a dense network of GPS stations within the territory of Azerbaijan. The results obtained so far indicate that the GPS velocity field quite clearly reflects the N-NE motion over the Azerbaijani territory and in the neighboring regions of the Lesser Caucasus relative to Eurasia. Along with these GPS stations, in the area of Sheki (northern Azerbaijan) a gravimetric station was also installed in order to get additional information on the deformation of the Earth caused by tidal forces and regional movements. Sheki station represents the unique Earth-tidal station in Azerbaijan, located in a high geodynamically active area, located in the foothills of Greater Caucasus.

Within this context, the project intends to perform a detailed investigation of the dynamical properties of the GPS and gravimetric signals acquired in Azerbaijan and to give a contribution to a better understanding of the deformation processes taking place in the Azerbaijani territory. In particular, the area monitored by Sheki station will be the main object of the present project, because both GPS and gravity measurements are concomitantly carried out, this leading to a more complete description of the underlying geodynamics.
The project combines the expertise of the two involved institutions in the study of earth processes aiming at refining the existing level of understanding of geodynamical mechanisms of seismicity, improving the knowledge about the dynamics of earthquakes, and contributing to seismic hazard assessment. These studies were never performed for the Azerbaijani territory so far. In this project the Azerbaijani team will be essentially devoted to the GPS and gravity measurement data storage, to study the seismo-tectonic and geologic settings, and to the development of a model of Earth's deformation in the investigated areas. On the other hand, the Italian team will be more dedicated to analyse the observational signals continuously measured by the Azerbaijani team, using advanced and robust statistical methodologies and well assessed nonlinear techniques (like spectral, fractal, multifractal, informational, decompositional, etc.) and to contribute in characterizing the deformation processes from a dynamical point of view, with clear implications in the context of seismic hazard.
The project is grounded in earth sciences, but has also a strong methodological component, and the cooperation between the involved institutions of CNR and ANAS offers a real synergistic advantage of exchange of data, statistical/mathematical methodologies and, in general, all the geophysical know-how. Furthermore, the project will strengthen the solid scientific relationship between the two institutions, successfully experienced in previous common projects.

The intended activities include: a) Analysis of the time series of GPS and gravimetric data measured in Azerbaijan; b) Development of a seismo-tectonic zoning of Azerbaijani territory on the base of the GPS and gravity measurements recorded during the period of validity of the project; c) Improvement of the seismic hazard assessment of Azerbaijan on the base of the up-to-date seismic recordings as well as the new information conveyed by the GPS and gravimetric time series analysis; d) Exchange visits of scientists as required to enhance the collaborative activities and generate research outputs; e) Generation of research outputs; both ongoing and final research results will be published in international journals and presented in conferences; f) Methodological and technological support for possible PhD students by both sides.

To perform such activities the available resources for the project are: 1) up-to-date GPS and gravimetric database of signals recorded at Sheki station; 2) detailed geological and tectonic settings; 3) previous macro-seismic studies performed by ANAS researchers and digital waveform data of all significant events relevant to focal mechanism and moment tensor analysis; 4) software (PreAnalyse, GMT and ETERNA); 5) methodological and statistical know-how in time series analysis.

The deliverables of the project are: 1) Database of the GPS and gravity measurements at Shaki station available for both the involved teams; 2) Velocity profiles and deformation maps; 3) Intermediate and final reports on the performed activities and obtained results; 4) Papers and abstracts submitted to international journals and conferences respectively with the acknowledgement of the CNR-ANAS bilateral agreement; 5) Webpage dedicated to the project (description, teams, data, results); 6) Seminars in Italy and/or Azerbaijan focused on the topics of the project.

Research goals

The specific objectives of the project are: 1) to create a database of GPS and gravity measurements at Sheki station (Azerbaijan) available for both the involved teams; 2) to study the influence of Earth-Moon system and the deformation of the Earth caused by tidal forces and regional contemporary movements and deformations; 3) to develop a geodynamical model of the Azerbaijani territory on the base of velocity profiles and deformation maps; 4) to characterize the time dynamics of GPS and gravimetric signals by using advanced statistical methods; 5) to disseminate preliminary and final results of the project in international conferences, publications, internet website; 6) to foster young researchers and Ph.D students in both the involved institutions.

Last update: 20/04/2024