Assessment of prospective geological hazards in Torrevieja-La Mata coast (western Mediterranean) based on Pleistocene and Holocene events

The coastal zone in which the lagoons of La Mata and Torrevieja (Eastern Spain) developed can be described as a compilation of geo-hazards typical of the Mediterranean realm. This study has focused mainly on those linked to recent tectonics. Extensive use of the amino acid racemization dating method allowed us to establish the evolution of all the geomorphological units differentiated in the area, the most striking manifestation being at the La Mata Lagoon Bar, where MIS 5 deposits settled on MIS 7 sediments along a marked erosive unconformity, thereby attesting coastal uplift between these two stages. In addition, recent uplift processes were reflected on stepped abrasion platforms and, in some cases, enormous boulders were transported over these platforms by extreme surge waves. Furthermore, we obtained feasible evidence that, during the end of MIS 5, an earthquake with an offshore epicenter linked to Torrevieja Fault, Bajo Segura Fault or the set of faults linked to the former, was responsible for tsunami surge deposits represented in accumulations of randomly arranged and well-preserved Glycymeris and Acanthocardia shells. Recent catastrophic effects linked to the earthquakes were also detected. In this regard, comparison of the paleontological and taphonomic analyses allowed us to discern between wave and tsunami surge deposits. Therefore, evidence of these hazards undoubtedly points to important future (and present) erosive and/or catastrophic processes, which are enhanced by the presence of tourist resorts and salt-mining industry. Thus, these sites are also threatened by future increases in sea level in the context of warmer episodes, attested by raised marine fossil deposits. At the north of Cervera Cape, beaches will be eroded, without any possibility of sediment input from the starved Segura River delta. At the south of this cape, waves (and tsunamis) will erode the soft rocks that built up the cliff, creating deep basal notches.

Assesment of prospective geological hazards in Torrevieja-La Mata coast (Western Mediterranean) based on Pleistocene and Holocene events

The coastal zone in which the lagoons of La Mata and Torrevieja (Eastern Spain) developed can be described as a compilation of geo-hazards typical of the Mediterranean realm. This study has focused mainly on those linked to recent tectonics. Extensive use of the amino acid racemization dating method allowed us to establish the evolution of all the geomorphological units differentiated in the area, the most striking manifestation being at the La Mata Lagoon Bar, where MIS 5 deposits settled on MIS 7 sediments along a marked erosive unconformity, thereby attesting coastal uplift between these two stages. In addition, recent uplift processes were reflected on stepped abrasion platforms and, in some cases, enormous boulders were transported over these platforms by extreme surge waves. Furthermore, we obtained feasible evidence that, during the end of MIS 5, an earthquake with an offshore epicenter linked to Torrevieja Fault, Bajo Segura Fault or the set of faults linked to the former, was responsible for tsunami surge deposits represented in accumulations of randomly arranged and well preserved Glycymeris and Acanthocardia shells. Recent catastrophic effects linked to the earthquakes were also detected. In this regard, comparison of the paleontological and taphonomic analyses allowed us to discern between wave and tsunami surge deposits. Therefore, evidence of these hazards undoubtedly points to important future (and present) erosive and/or catastrophic processes, which are enhanced by the presence of tourist resorts and salt-mining industry. Thus, these sites are also threatened by future increases in sea level in the context of warmer episodes, attested by raised marine fossil deposits. At the north of Cervera Cape, beaches will be eroded, without any possibility of sediment input from the starved Segura River delta. South of this cape, waves (and tsunamis) will erode the soft rocks that built up the cliff, creating deep basal notches and causing rockfall and the collapse of the overlying buildings.

Global geodetic parameters obtained from 14 years Lageos 1 Satellite Laser Ranging

<p>Satellite Laser Ranging (SLR) data of the geodynamic satellite Lageos-1 (LAser GEOdynamics Satellite) for the period January 2000 - June 2013 are processed and analysed through sequential estimation to obtain multiyear solution for global geodetic parameters - coordinates and velocities of 37 stations located on the main tectonic plates. The analysis is carried out with the Satellite Laser Ranging Processor (SLRP) software, version 4.3, developed in the Department Geodesy of the National Institute of Geophysics, Geodesy and Geography at Bulgarian Academy of Sciences. The software consists of two main programs – orbit determination and parameter estimation modules. Total number of 202 447 measurements are processed and analyzed by monthly batches. Arc dependent parameters, geogravitational parameter - GM, Earth Orientation Parameters (pole coordinates and length of the day - LOD), along track and solar radiation pressure coefficients are obtained from monthly solutions. The weighted root mean squares of the monthly station coordinates solution are between 2 and 16 mm. The analysis of monthly GM time series reveal value of the secular trend Ġ/G = -3.31. 10<sup>-13</sup>yr<sup>-1</sup>. The results obtained contribute to the monitoring of recent tectonics of the major continental plates and global geodynamic parameters.</p>

Analysis of the recent Plio-Quaternary deformation and the correlation with the focal mechanisms of the significant earthquakes in the Bokoya, Ras Tarf (Eastern Rif)

Relative movements of microplates developed between the African and Eurasian plate characterize the continuity of the tectonic movements in Westerner of the Mediterranean Sea. The convergence movements between these plates, at the origin of the current structuring in oriental Rif. The recent tectonics in the south ripple of Alboran Sea, translated by an important seismic activity, In the North of Morocco, exactly in the Al Hoceima region, considered as zone of plates border with important seismicity. The structural analysis made in this paper and the interpretation of focals mechanisms earthquakes characteristics in the Al Hoceima region, has allows to deduct the main directions of faults, which we compared with the results of the satellite images. This study we has provides to demonstrate the directions of faults which are able to generate earthquakes in the future. The direction NE-SW represents the overall faults dominant in oriental Rif, this major direction coincides with the breaks of surface. A reduced number of faults shows a generall direction NNE-SSO to N-S through the Quaternary formations in the NO of Al Hoceima city, the direction NO does not show a good correlation with the directions of surface rupture, as well as with the deducted directions from focals mechanisms. This study drives us to propose that faults of direction NNE-SSO to NE-SO, represent the major directions of the faults in the Al Hoceima region, which represents the main cause of the seismic activity in the region.

The actual problems of the study of the recent platform structures (on the example of the East European platform and the adjacent partof the Scythian plate)

The actual problems of the study of recent tectonics of the East European Platform and the Scythian Plate: development of cover formations of neotectonic structures, discontinuous distribution and bad of safety of correlative deposits, different views on the type of structural forms - block or bending, the nature and type of boundaries between structural forms, a change in the structural plans for the latest phase, the conditions and sources of stress in the formation of new structures.