Field study at seven Scottish sites has resulted in the following evidence for late- and post-glacial earthquakes and fault movements. a) Glen Roy, western Highlands: Earthquake-induced deformation structures are observed in 10,000 year-old lake deposits, and can be related to a surface fault rupture and several landslides. The deformation structures have been mapped over an area of 100 sq. km and display most intense deformation in a central area, with decreasing degrees of deformation in peripheral zones. This zonation is interpreted in terms of varying intensities of ground-shaking during a major earthquake. The field data indicate a magnitude 6.25 event. b) Kinloch Hourn, western Highlands: A prominent, 14-km long fault displays evidence for recurrent movement. A magnitude 5.5-6.0 event occurred between 3500 and 2400 years ago, and unquantified movement has occurred since then. c Firth of Lorn (west coast): Levelling survey, at two sites, indicates several vertical displacements of up to 3m, of a 10,000 year old raised shoreline. d) Lismore (west coast): Lateral fault displacements of c. 0.5m have disrupted present rock and soil morphology and indicate movement in the last few thousand years. e Tayside, eastern Scotland: Two sites display soft-sediment deformation structures in late-glacial sands and silts. The structures are interpreted as the result of (unquantified) earthquake ground-shaking. This field evidence is collectively evaluated in terms of crustal stress, earthquake recurrence and present-day earthquake hazard. Earthquakes as large as magnitude 7 are thought to have occurred but were probably triggered by glacial rebound stesses. Earthquakes upto magnitude 6 have certainly occurred, some as recently as 3000 years ago, and are likely to recur. Present-day surface fault displacements of up to 0.1m are considered likely on fractures favourably orientated with respect to the present-day stress field.

Kατά τις τελευταίες δύο δεκαετίες θεωρείται ότι υπάρχουν ενδείξεις πιθανού συσχετισμού των μεταβολών του εκλυόμενου ραδονίου στο έδαφος και της σεισμικής δραστηριότητας. Παρότι στην Ελλάδα εκδηλώνεται το μεγαλύτερο μέρος της σεισμικής δραστηριότητας της Ευρώπης, δεν έχουν πραγματοποιηθεί συστηματικές έρευνες έως τώρα. Η περιοχή της διατριβής καλύπτει την ανάγκη ανάλυσης της έκλυσης ραδονίου από περιβαλλοντικές παραμέτρους και τη σεισμικότητα. Το πείραμα χωροθετήθηκε στην περιοχή του Κορινθιακού κόλπου λόγω του ότι: 1) παρουσιάζεται υψηλή σεισμικότητα, η σεισμικότητα σε αυτή την περιοχή δε είναι εντοπισμένη σε ένα συγκεκριμένο τμήμα της, αλλά χαρακτηρίζει την ευρύτερη περιοχή. 2) Στην περιοχή εκδηλώνονται συχνά σεισμικά γεγονότα όλων των μεγεθών, σχετιζόμενα με τη σεισμικότητα της ίδιας της περιοχής, αλλά και λόγω διέγερσης σεισμικών ρηγμάτων στην εγγύς περιοχή (π.χ. σεισμοί Αλκυονίδων 1981 και σεισμοί Αθήνας 1999). 3) Η ύπαρξη στην περιοχή ενός μεγάλου αριθμού ρηγμάτων, τα οποία έχουν σαφή επιφανειακή έκφραση. Η ύπαρξη ρηγμάτων με σαφή επιφανειακή έκφραση δίνει επιπλέον τη δυνατότητα μέτρησης της ροής ραδονίου μέσα από ένα ρήγμα. 4) Στην περιοχή μελέτης υπάρχουν καλής ακρίβειας σεισμολογικά και μετεωρολογικά δεδομένα, έτσι ώστε να μπορεί να συσχετισθεί η επίπτωση των μετεωρολογικών αλλαγών με τις μετρήσεις ραδονίου. Η συγκεκριμένη περιοχή δε χαρακτηρίζεται από βίαιες μετεωρολογικές μεταβολές, οι οποίες επηρεάζουν την έκλυση του ραδονίου. / Over the last decades evidence for correlation between radon emission and earthquake activity suggests that monitoring of radon in soil gas can be used as a method to predict future earthquakes. However, although the method is promising for earthquake prediction and most of the seismic activity in Europe is released in Greece, no systematic experiments were conducted so far. In this study we present preliminary results of a two years experiment through the monitoring of eight sites in the Megara basin. In each site, soil radon exhalation was monitored in shallow boreholes (80 cm deep), using CR39 films, which were exposed every 15-day. The Megara basin was selected as a study area for the following reasons: (a) the basin is actively deformed and most of this deformation is accommodated by strong historic earthquakes. The most recent of these events are the 1981 Corinth earthquake sequence. (b) Within the basin large faults have spectacular outcrops, and or still preserve seismic ruptures. Thus the tectonic setting of the monitoring sites is well known in its tectonic position. (c) The entire experiment is set up quite close to Athens, thus earthquake epicenters are calculated fairly well and detailed meteorological data are also available. The experiment includes a series of monitoring sites distributed from Megara town to the coast of the Alkyonides bay, that it well known as the epicenter of the 1981 Corinth earthquakes. In essence the coastal area of the Gulf is rather the surface expression of the South Alkyonides Fault zone. Surface displacement along this fault during the 1981 event reached up to 1 m north side down. Based on these monitoring sites, we present the first results regarding the background soil radon concentration in the Megara basin as well as radon exhalation through a fault. Specifically, we present data of radon exhalation through a still preserved co-seismic rupture, 20 north of the rupture on the hanging wall block and 200 m south of the rupture within the footwall block of the South Alkyonides Fault zone.