Nowadays, Early Warning Systems (EWSs) are of great importance for urban seismic risk and emergency management. In this work, we describe the development and combination of a series of approaches for constructing a database of earthquake spatial effects towards creating a EWS for the Lefkada old town, situated in one of the most seismically active areas of the Mediterranean region. The geospatial information presented regards the earthquake damage probability at the target site and it is derived from seismic scenarios developed by combining seismic sources, vulnerability of buildings and site effects.Vulnerability was assessed empirically for individual buildings through a field survey.Site effects were determined using dense ambient noise HVSR measurements atselected points in Lefkada old town and available data from geotechnical boreholes.1D viscoelastic soil models were determined for each point by inverting the HVSRcurves using a Monte Carlo approach. Peak ground acceleration was assessed at each point using the point-source stochastic simulation scheme, by applying the siteamplification deduced from the 1D viscoelastic models. Seismic risk scenarios weredeveloped assuming two seismic sources (a) the earthquake on August 14th 2003 with M6.2 at a distance of 13 km from Lefkada old town and (b) a future nearest maximum credible earthquake with M7 at the same distance.The discrete damage probability was resolved by formulating a beta distribution of an average damage grade related to the vulnerability and the simulated PGA through empirical equations. The obtained models are found to be comparable with co-seismic observations during the 2003 earthquake and hence they are likely appropriate for preparing future emergency plans for the target site. An adaptable Arc-GIS automated procedure to map earthquake damage scenarios is currently being developed by implementing the above mentioned methods.

This work presents the current state of seismic vulnerability in Greece, the most seismically active region in Europe and the corresponding impacts of austerity measures imposed to the nation during the last five years. The analysis of physical risks and socio-economic conditions shows a very dangerous situation, which has to be promptly confronted, in terms of a revised and prioritized National reinforcement effort regarding pre-seismic preparedness and post-seismic interventions. The latter certainly requires funding, however it has to be coupled with restorative measures for the existing socio-political status embracing authorities, communities and individuals.

The present work constitutes the first part of a multi-parametric research for the representation of damage scenarios in Lefkada old town. The study area lies in the most seismically active zone of Greece and has suffered several devastating earthquakes. Most of its old buildings were built by local practices incorporating elements of earthquake resistance and have been designated as particular earthquake resistant constructions by the European Council Cultural Heritage Unit. The most recent earthquake of {\$}{\$}{\backslash}hbox {\{}M{\}}{\_}{\backslash}mathrm{\{}w{\}}=6.2{\$}{\$}Mw=6.2that occurred on 14 August 2003, located about 10 km from the town, caused moderate damage to its buildings and substantial geotechnical failures. Investigations on the coseismic effects yielded extensive literature information, which initially motivated our investigations. This paper deals with the empirical vulnerability assessment of the buildings in Lefkada old town based on basic structural characteristics such as the type and material of the structural system, the period of construction, the number of storeys, etc. Those characteristics, primarily available from the most recent available census were further exploited by an in-situ survey, during which all 1,420 buildings in the old town were inspected. Following, each building was indexed with an EMS-98 vulnerability class. Expert decisions on the damage scale due to the 14 August 2003 event were reassessed and converted into damage grades of EMS-98. The full data set was also analysed in ArcGIS producing detailed maps of the 14 August 2003 earthquake damage distribution by structural typology and vulnerability class in Lefkada old town.

We report cm-size dynamic displacements of continuous GPS stations onshore the island of Cephalonia, Ionian Sea, Greece, following the passage of seismic waves from two (2) shallow earthquakes on Jan 26, 2014 and Feb 3, 2014, respectively. First, we estimated the displacements from the high-rate GPS data collected at NOA station VLSM, near to the epicenters, by using state-of-art data processing strategies. The time series of displacements were analyzed both in time and frequency domains. From the dynamic analysis of 1Hz data it is shown that the second event was recorded at station VLSM with higher amplitudes on both horizontal components, despite its smaller (22 %) moment magnitude, possibly due to its shallower depth. The static field of deformation is characterized by cm-size permanent motion in opposing directions between stations KIPO (western Cephalonia) and VLSM (eastern Cephalonia), in agreement with the right-lateral kinematics of both ruptures. The 7.4 cm northward motion of station KIPO implies that the western peninsula of Cephalonia island (Paliki) belongs to a separate crustal block with respect to the rest of the island. The northward motion of KIPO also implies that the Cephalonia Transform Fault (CTF) did not rupture during the 2014 events, because KIPO is located at the hanging wall of CTF. It is possible that the amount of accumulated strain along CTF since 1983 (M=6.8) can be released by a seismic event of M6.5-6.7, at any time.

This study focuses on a series of small intraplate earthquakes that took place during May–August 2013 on the southwestern coast of the Corinth Rift (Central Greece), a few km southeast of Aigion city. The Corinth Rift is one of the most seismically active parts of the Mediterranean. We analyzed more than 1500 events with 0.4≤ML≤3.7, the major part of which was recorded by a dense local network. The seismicity is densely clustered in a volume of dimensions ∼4×2×6km3, aligned in a N110° direction and at depths ranging between 6 and 12km. Precisely relocated hypocenters and reliably constrained focal mechanisms indicate north dipping planar faults with an average dip of ∼60°. Stress inversion of focal mechanisms implies that the dominant local stress field is extensional in a N5° direction, in good agreement with geodetic observations. The swarm evolved in two phases, with a spatiotemporal migration of epicenters from the eastern toward the western part of the rupture zone, while slip distribution appears homogeneous over the eastern part and strongly inhomogeneous in the western part. These two phases also produced different results in scaling relations such as the Gutenberg–Richter law, the Modified Omori Formula and the Epidemic Type of Aftershock Sequence model. Similar results from other studies have been reported and correlated with a fluid driven mechanism, however further research is required to strengthen this hypothesis for the purposes of this study.

Damage scenarios were developed for the Lefkada old town (LOT). LOT is the historical center of the capital of Lefkas Island, part of the Ionian Islands, one of the most seismically prone areas within the Mediterranean region that suffered numerous devastating earthquakes in the past. The most recent strong earthquake with Mw = 6.2 occurred on 14 August 2003 at a distance of about 13 km from LOT. A peak ground acceleration (PGA) equal to 0.42 g was recorded in LOT, one of the highest values ever recorded in Greece. Nevertheless, the 2003 event produced limited damage to the buildings of LOT, comprising traditional construction practices of architectural significance and a high seismic behaviour. Towards the development of damage scenarios the following tasks were performed: (a) buildings inventory and vulnerability indices determination using EMS-98 along with behaviour modification scores, (b) subsoil response functions and 1D visco-elastic models calculation using microtremors and (c) stochastic PGA simulation using site amplification deduced from the subsoil response functions. Two scenarios were developed considering the sources of the 2003 M6.2 earthquake and a future M7 event, located at the same fault. The discrete damage probability was resolved by formulating a beta distribution of an average damage grade related to the vulnerability index and the simulated PGA through empirical equations. The deduced models are comparable with the observed 2003 damage distribution, hence they are likely useful for preparing future emergency plans. In the aftermath, although further investigation is needed to explain outliers, the implementation of the followed methodology into an automated procedure for near real time shake and damage maps generation in case of a seismic crisis is highly recommended. The work herein, with proper adaptations, is potentially fairly applicable for other towns and regions in Europe.