RECENT GEOMORPHIC CHANGES AND ANTHROPOGENIC ACTIVITIES IN THE DELTAIC PLAIN OF PINIOS RIVER IN CENTRAL GREECE

The Pinios river delta is a Late Holocene arcuate type delta, located in the southern Thermaikos gulf (Central Greece). In order to determine the processes which contributed in the recent configuration of the delta, a detailed geomorphic map at the scale of 1:5000 has been prepared showing both the deltaic plain and the coastal zone features using GIS techniques. Comparative examinations of aerial photographs taken in different dates and reliable maps of the last two centuries along with field observations depict recent changes of the delta morphology. The most important factors for the development of the delta are fluvial sedimentation, wave activity and longshore currents in a tectonically active area. Land uses throughout the delta plain have been mapped in an attempt to identify socio-economic activities. The dominant feature in the deltaic plain is the numerous abandoned meandering channels. The delta shoreline is generally retreating due to marine processes especially where former river mouths occur. Finally, various future sea-level rise scenarios have been analyzed and an assessment of the impacts of the potential global future sea-level rise to the delta is estimated

Assessment of neotectonic landscape deformation in Evia Island, Greece, using GIS-based multi-criteria analysis

This study deals with the assessment and mapping of neotectonic landscape deformation in the northern part of the Evia Island (Central Greece). Multi-Criteria Decision Analysis (MCDA) utilizing Analytic Hierarchy Process (AHP) andWeighted Linear Combination (WLC) procedures were conducted for the calculation of the Neotectonic Landscape Deformation Index (NLDI). The study is based on the combination of morphotectonic, geomorphological and geological parameters. The GIS-based spatial MCDA led to the classification of the study area into five classes of neotectonic deformation (from very low to very high) and to a neotectonic deformation map. The results were compared with the outputs of a relative tectonic activity classification approach based on quantitative geomorphic analysis at a regional scale, including site-specific field observations. Areas of high and very high deformation are related to the major active faults of Dirfis, Kandili and Gregolimano- Telethrio. Other minor active normal faults of medium to high seismic risk level, affecting the northern and northeastern parts of the island, are also associated with areas of intense landscape neotectonic deformation

GEOMORPHOLOGY AND SEDIMENTOLOGICAL PROCESSES ALONG THE COASTAL ZONE BETWEEN LIVANATES AND AGIOS KONSTANTINOS (N. EVOIKOS GULF, CENTRAL GREECE)

This study deals with aspects of geomorphology and nearshore marine processes in the coastal zone located between Livanates and Agios Konstantinos (North Evoikos Gulf, central Greece). Evoikos Gulf is a tectonic graben bounded by WNW-ESE trending normal faults; it can be further characterized as semi-closed marine basin with water depths exceeding 400m.The Coastal geomorphology is affected by active tectonics with the most prominent morphological features being the uplifted marine terraces and the well-developed deltaic fan of Xerias torrent. In the present investigation, detailed geomorphological mapping at a scale of 1:5000 was performed together with granulometric analysis, while nearshore wave and current activity related to sediment dynamics has been determined on the basis of wind-generated wave regime. The examined coastal zone consists of a series of alluvial cones and fans, Xerias fan being the largest among them, low cliffs, a cuspate foreland and beach zones of limited length, often hosting beachrock formations. The formation and evolution of the study area seems to be controlled by the limited terrestrial influxes, the relatively weak wave regime due to limited wave fetches distances, and the associated longshore currents that induces limited sediment transport

Recognition of past earthquakes along the Sparta fault (Peloponnesus, southern Greece) during the Holocene, by combining results of different dating techniques

Sparta fault is an impressive landform, located on the eastern front of Taygetos mountain, southern Greece. Detailed morphotectonic observations on this fault suggest that it should be active at least since Early Quaternary. However, according to the current seismological knowledge, this region is characterized by very low seismicity. The only reported earthquake to have occurred in this area is that of 464 b. c., a destructive event that devastated the whole city of Sparta. In order to get information on the occurrence of past earthquakes during the Holocene, results of different independent dating works that have performed along the Sparta fault were used. These researchers confirm the existence not only of the 464 B.C. earthquake but also of several more that occurred at ca. 3900 b. c., 2500 B.C. and 2000 B.C., 550 A.D. and 1000 A.D. The events that occurred at 2500 and 464 B.C. should correspond to major events of magnitude of the order of 7, which ruptured the entire length of the fault, while these at 3900 B.C., 2000 B.C., 550 A.D. and 1000 A.D., to smaller events of magnitude 6-6.5. The return periods of strong earthquakes along the Sparta fault is estimated to be around 2000 years, but within these periods events of smaller magnitude that ruptured segments of the fault have also occurred. © 2005 Elsevier Ltd. All rights reserved

Geomorphic and archaeological -historical evidence for past ealihquakes in Greece

Geomorphic observations focused on landforms of marine and fluvial origin such as notches, beachrocks, stream channel shifts, alluvial terraces and knickpoints, when combined with historical and archaeological information are able to date seismic events that took place in the past in some places of the Peloponnesus. At thc Eastern Gulf of Corinth, a seismically active area, all the geomorphic observations fit quite well with the deformation field induced by the action of an offshore fault. At Mycenae, a seismically inactive area with no historical evidence of earthquakes, the archaeological information is the only evidence for past earthquakes while geomorphic data indicate the most probable activated fault. At Sparta, an area of low seismicity but with historical evidence of destructive earthquakes, the geomorphic evidence helps to identify the most likely ruptured fault. At Eliki, a seismically active area with well documented historical activity, the geomorphic data serve to define the causative fault.This paper shows that although historical and archaeological data provide evidence far the occurrence of past earthquakes and often their date, geomorphic observations must be used to identify the causative fault

Geomorphic and archaeological -historical evidence for past ealihquakes in Greece

Geomorphic observations focused on landforms of marine and fluvial origin such as notches, beachrocks, stream channel shifts, alluvial terraces and knickpoints, when combined with historical and archaeological information are able to date seismic events that took place in the past in some places of the Peloponnesus. At thc Eastern Gulf of Corinth, a seismically active area, all the geomorphic observations fit quite well with the deformation field induced by the action of an offshore fault. At Mycenae, a seismically inactive area with no historical evidence of earthquakes, the archaeological information is the only evidence for past earthquakes while geomorphic data indicate the most probable activated fault. At Sparta, an area of low seismicity but with historical evidence of destructive earthquakes, the geomorphic evidence helps to identify the most likely ruptured fault. At Eliki, a seismically active area with well documented historical activity, the geomorphic data serve to define the causative fault.This paper shows that although historical and archaeological data provide evidence far the occurrence of past earthquakes and often their date, geomorphic observations must be used to identify the causative fault