with 18 fi gures and 2 tables Summary. Th is paper presents geo-scientifi c evidence of beachrock-type calcarenitic tsunamites from three study areas in western Greece, namely from the Bays of Aghios Nikolaos (Akarnania), Langadakia (Cefalonia Island) and Aghios Andreas (Peloponnese). Geomorphological, sedimentological, micromorphological and geochemical studies were conducted to clarify depositional processes and the post-sedimentary evolution. Calcarenitic and locally conglomeratic carbonate crusts were studied in natural outcrops along the seafront and in vibracores. High-resolution topographic surveys and 3D-visualisation were carried out by diff erential GPS and LIDAR measurements. Tsunami impact was dated by a combined approach of radiocarbon, OSL and archaeological age determination and compared to local tsunami and earthquake chronologies. We found sedimentary structures such as basal unconformities, rip-up and intra-clasts, evidence of fi ning upward, thinning landward and upward increase in sorting as well as bi-to multimodal deposits and injection structures all of which are described as features typical of recent or historic tsunami deposits. Typically non-littoral sedimentary features such as load casts and convolute bedding further indicate gravity driven processes in water-saturated sheets of allochthonous deposits and are well known from, for example, turbidites. Moreover, thin section analyses revealed highenergy shock-and impact-borne cracking and shearing eff ects. Our results show that cementation of tsunami deposits may occur by post-depositional pedogenetic decalcifi cation of higher sections and subsequent secondary carbonate precipitation in lower sections of tsunami deposits provided that they were deposited above sea level. Th e calcarenitic tsunamites encountered in the three study areas match the defi nition of beachrock sensu stricto. Th is is thus the fi rst paper giving examples of beachrock sequences that are interpreted as partially cemented tsunami deposits. Consequently, beachrock is recommended not to be used as sea level indicator in future studies unless a tsunamigenic formation can be defi nitely excluded. Dating results brought to light young, mostly Holocene ages of tsunami sediments. In the Bay of Aghios Andreas, western Peloponnese, we found spectacular traces that Olympia's ancient harbour site Pheia was destroyed by tsunami impact in the 6 th cent. AD and covered by a rapidly cemented, up to 3 m-thick beachrock-type tsunami deposit. Zusammenfassung. Dieser Aufsatz stellt geowissenschaftliche Belege für Beachrock-artige kalkarenitische Tsunamite aus drei Untersuchungsgebieten Westgriechenlands vor, nämlich der Bucht von Aghios Nikolaos (Akarnanien), der Bucht von Langadakia (Kephallonia) und der Bucht von Aghios Andreas (Peloponnes). Geomorphologische, sedimentologische, mikromorphologische und geochemische Analysen dienten der Klärung von Ablagerungsprozessen und der postsedimentären Entwicklung. Kalkarenitische und lokal konglomeratische Karbonatkrusten wurden in natü...
Abstract. The deformation pattern of the 6 and 7 April 2009 MW=6.3 and MW=5.6 earthquakes in L'Aquila is revealed by DInSAR analysis and compared with earthquake environmental effects. The DInSAR predicted fault surface ruptures coincide with localities where surface ruptures have been observed in the field, confirming that the ruptures observed near Paganica village are indeed primary. These ruptures are almost one order of magnitude lower than the ruptures that have been produced by other major surrounding faults in the past. These faults have not been activated during the 2009 event, but have the capacity to generate significantly stronger events. DInSAR analysis shows that 66% (or 305 km2) of the area deformed has been subsided whereas the remaining 34% (or 155 km2) has been uplifted. A footwall uplift versus hangingwall subsidence ratio of about 1/3 is extracted from the mainshock. The maximum subsidence (25 cm) was recorded about 4.5 km away from the primary surface ruptures and about 9 km away from the epicentre. In the immediate hangingwall, subsidence did not exceeded 15 cm, showing that the maximum subsidence is not recorded near the ruptured fault trace, but closer to the hangingwall centre. The deformation pattern is asymmetrical expanding significantly towards the southeast. A part of this asymmetry can be attributed to the contribution of the 7 April event in the deformation field.
The purpose of this study is to assess the susceptibility of landslides at the eastern part of Messinia prefecture using GIS and Multicriteria Decision Analysis. Analytic Hierarchy Process and Weighted Linear Combination method were used to create a landslide susceptibility map for the study area. The produced map provides valuable information concerning the stability conditions of the territory and may serve as the first step in a complete hazard assessment towards the mitigation of natural landslide disasters in Messinia Prefecture area. Particularly the intention is to transfer effectively information regarding slope stability to non-geologists who take decisions for future land use planning processes and major construction projects.
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