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The Parnitha mountain range lies between two Quaternary rift systems in central Greece: the Gulf of Corinth Rift and the Gulf of Evia rift. We suggest that the range was formed by footwall uplift on active normal faults striking WNW–ESE and NE–SW. We investigated the scarp appearance, geometry and slip rates of three normal faults bounding this mountain range by field mapping at 1:5000 scale. Active faults studied include the 8.5 km long Fili Fault, the 4.7 km long Maliza Fault and the 4 km long Thrakomakedones Fault. We calculated comparable mean slip rates for all mapped faults (Fili: 0.18 mm/yr, Avlon: 0.2 mm/yr, Thrakomakedones: 0.24 mm/yr); however, we suggest that the WNW–ESE structures are more active during the Late Quaternary because of abundant field evidence of recent movements along slip surfaces (fresh basal stripes and slickenlines). In addition, stress axes analysis shows a N7°E–N25°E (NNE–SSW) oriented, extensional stress field, which is compatible with the focal mechanism of the Athens 1999 earthquake. The fault-slip data from the Parnitha faults show orientations similar to other low-strain areas in central Greece, such as the Gulf of Evia Rift to the north. Our slip rate estimates may explain the low recurrence of large earthquakes in Attica as opposed to high slip rate areas in central Greece such as the neighbouring Gulf of Corinth

The Greek Database of Seismogenic Sources (GreDaSS) is a repository of geological, tectonic and active-fault data for the Greek territory and its surroundings. In this report, we present the state-of-the-art of an on-going project devoted to the building of the GreDaSS, which represents the results of decades of investigations by the authors and a myriad of other researchers working on the active tectonics of the broader Aegean Region. The principal aim of this international project is to create a homogeneous framework of all of the data relevant to the seismotectonics, and especially the seismic hazard assessment, of Greece and its surroundings, as well as to provide a common research platform for performing seismic hazard analyses, modeling and scenarios from specific seismogenic structures. In particular, we introduce and synthetically describe the results obtained (and included in the database) to date in the northern sector of continental Greece and the Aegean Sea. As a first step we collected all available (both published and unpublished) historical and instrumental seismicity data relevant to the determining of the causative faults. Following the experience of recent 'surprising' earthquakes (e.g. 1995 Kozani, and Athens), we realized the deficiency of such an approach, and decided to also include in the GreDaSS active faults (i.e. seismogenic sources) recognized on the basis of geological, structural, morphotectonic, paleoseismological and geophysical investigations. A second step is the critical analysis of all of the collected data for the extraction of the necessary seismotectonic information, enabling the recognition of as many seismogenic sources as possible, as well as their characterization and parameterization. The most updated version of the database consists of numerous seismogenic sources that are categorized into three types: composite, individual, and debated. In this report, we describe the major seismotectonic properties of all of the composite seismogenic sources and individual seismogenic sources in northern Greece, which imply the partitioning of the area into five sectors that show similar internal behavior. Northern Greece was chosen as a pilot area because the parameters and accompanied metadata of its seismogenic sources show a high level of confidence and completeness. The amount of information and the degree of uncertainty is different for the three types.

The design of critical facilities needs a targeted computation of the expected ground motion levels. The Trans Adriatic Pipeline (TAP) is the pipeline that transports natural gas from the Greek-Turkish border, through Greece and Albania, to Italy. We present here the probabilistic seismic hazard analysis (PSHA) that we performed for this facility, and the deaggregation of the results, aiming to identify the dominant seismic sources for a selected site along the Albanian coast, where one of the two main compressor stations is located. PSHA is based on an articulated logic tree of twenty branches, consisting of two models for source, seismicity, estimation of the maximum magnitude, and ground motion. The area with the highest hazard occurs along the Adriatic coast of Albania (PGA between 0.8 and 0.9 g on rock for a return period of 2475 years), while strong ground motions are also expected to the north of Thessaloniki, Kavala, in the southern Alexandroupolis area, as well as at the border between Greece and Turkey. The earthquakes contributing most to the hazard of the test site at high and low frequencies (1 and 5 Hz) and the corresponding design events for the TAP infrastructure have been identified as local quakes with MW 6.6 and 6.0, respectively.

In May 2012, two earthquakes (Mw 6.1 and 5.9) affected the Po Plain, Italy. The strongest shock produced extensive secondary effects associated with liquefaction phenomena. Few weeks after the earthquakes, an exploratory trench was excavated across a levee of the palaeo‐Reno reach, where a system of aligned ground ruptures was observed. The investigated site well preserves the geomorphic expression of a fluvial body that mainly formed in the fifteenth to sixteenth centuries as historical sources and radiometric data testify. In the trench several features pinpointed the occurrence of past liquefaction events: (i) dikes filled with overpressured injected sand and associated with vertical displacements have no correspondence with the fractures mapped at the surface; (ii) thick dikes are buried by the plowed level or even by fluvial deposits; (iii) although some of the 2012 ground fractures characterized by vertical displacement and opening occurred in correspondence of thick dikes observed in the trench, sand and water ejection did not occur; (iv) some seismites (load casts) were observed in the trench well above the 2012 water level. The results strongly suggest that shaking has locally occurred in the past producing a sufficient ground motion capable of triggering liquefaction phenomena prior to, and likely stronger than, the May 2012 earthquake. Historical seismicity documents three seismic events that might have been able to generate liquefaction in the broader investigated area. Based on the analysis of their macroseismic fields, the 17 November 1570 Ferrara earthquake is the most likely causative event of the observed palaeoliquefactions.

The new reasearch project to create the Greek Catalogue of Active Faults and Database of Seismogenic Sources has three major goals: (i) the systematic collection of all available information concerning neotectonic, active and capable faults as well as broader seismogenic volumes within the Aegean Region; the search will be mainly based on geological and geophysical data; (ii) the quantification of the principal seismotectonic parameters of the different sources and the associated degree of uncertainty; (iii) to supply an integrated view of potentially damaging seismogenic sources for a better assessment of the Seismic Hazard of Greece. The informatic framework of the database follows that used for the Italian Database of Individual Seismogenic Sources (DISS). In this paper we present the architecture of the new Database of Active faults of the broader Aegean Area relative to Greece, the progress made up to present and the following activities yet to be accomplished.

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We study the neotectonic regime and evolution of the central-eastern part of the Asopos River basin (Beotia, Central Greece) which is an area undergoing crustal extension. The main tools that were used in this research were a) field mapping of neotectonic and active normal faults and b) morphotectonic analysis of 59 catchments, which was carried out by GIS techniques. Our results include a) series of maps displaying the spatial variation of morphotectonic indices (sinuosity, asymmetry factor, valley-floor-to-height-ratio etc) and b) map of neotectonic fault segments with associated faultslip data. The morphotectonic analysis indicates that if normal faults in this area are active, they are capable of generating earthquakes with M >6.0.