MORPHOTECTONIC EVALUATION OF SIRCH MOUNTAINS USING WATER BASIN GEOMORPHIC INDICES

Morphotectonic indices are useful instruments for investigating the effect of tectonic activity in a certain region. Calculation of these indicators using the advantages of Geographical Information System, GIS, in a large area is useful for detecting potential disorders related to active tectonics. This method is useful in regions on which few morphotectonic studies have been conducted. An example of such areas can be the watersheds of the Sirch mountainous region. The watersheds of the Sirch region located in Central Iran’s zone in the southeast of Iran are a very ideal zone to evaluate the concepts of these indicators in the prediction of the relative tectonic activity according to the investigation of drainage systems or mountain fronts. Based on the values of the calculated indices including Form Factor (FF), Compaction Coefficient (CC), Ratio of Circularity (RC), Ratio of Elongation (RE), relative Basin Height (BH), and Ruggedness Number (RN), a final indicator called Active Tectonic Indicator (ATI) is obtained. The latter is a combination of the abovementioned indicators and evaluates the morphotectonic activity based on the shape of the watersheds. By measuring and combining these indicators, the tectonic activity stage of the Sirch region was determined by analyzing the watersheds of this region.

MORPHOTECTONICS OF THE PSATHOPYRGOS ACTIVE FAULT, WESTERN CORINTH RIFT, CENTRAL GREECE

The study area is located on the western part of the Gulf of Corinth which is considered as a paradigm of an active rift system in Greece. This rift was formed by normal slip on big faults which extend the crust of the Earth in the N-S direction. The morphotectonic indices (hypsometric curve, hypsometric integral, drainage basin asymmetry, ratio of valley floor width to valley height) have been estimated using the 20-m digital elevation model of this area and the ARC software. The normal faults of the study area have been extracted by use of a DEM mosaic of 20-m pixel size, satellite images from Landsat 7 ETM+ and SRTM 90m. Our results highlight the recent activity of the Psathopyrgos normal fault on the basis of a series of morphotectonic evidence and suggest the existence of a single fault segment for a distance of 16 km.

MORPHOTECTONIC ANALYSIS OF THE NEOTECTONIC AND ACTIVE FAULTS OF BEOTIA (CENTRAL GREECE), USING G.I.S. TECHNIQUES

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.

Morphotectonic analysis of faults in Sperchios Basin (Fthiotis, Central Greece).

This paper aims to study one of the major neotectonic, fault-controlled, features of the Hellenides, Sperchios basin, with the application of specific morphotectonic indices. The study area includes well exposed fault-bounded mountain fronts with dominant footwall relief. The most prominent structures of this WNW-ESE trending neotectonic basin are WNW-ESE to NW-SE trending faults, the most prominent of which is the Sperchios Fault System (SFS) causing mainly subsidence toward the NNE. The antithetic Coastal Fault System (CFS) also forms a distinct, yet gentler relief at the NE basin boundary. The segmentation of these neotectonic faults allowed detailed measurements, based on morphotectonic characteristics, of each segment separately. Mountain-front sinuosity (Smf) as well as the ratio of valley floor width to valley height (Vf) were among the indices used in this study and contributed to the identification of the potential fault activity. The results show that there is a strong correlation between uplift rates and the morphotectonic signature of faulting, as well as a clear morphotectonic differentiation of fault segments.

Μορφοτεκτονική μελέτη της ευρύτερης περιοχής Θεσ/νίκης για τη χαρτογράφηση νεοτεκτονικών ρηγμάτων.

At this paper studied the neotectonic active faults of the broader area of Thessaloniki with morphotectonic criteria. We have studied three main faults of Anthemounta, Asvestophori and Pylaia - Panorama with the contribution of cartography, digital elevation models, drainage patterns, and the morphotectonic indices like drainage basin asymmetry, mountain front sinuosity, knick points and stream length-gradient index. Those faults show elements of activity.