Geomorphological Analysis of Xilokastro Fault, Central Gulf of Corinth, Greece

Sotirios Verroios,Vasiliki Zygouri

doi:10.3390/geosciences11120516

Abstract

The Gulf of Corinth is a rapidly opening area with high seismicity associated with extensive building collapses, destruction of cities, and even the deaths of inhabitants. Rapid residential development, especially in the southern part of the Gulf of Corinth, and the construction of crucial technical infrastructures necessitate understanding the activity across crustal-scale faults that host devastating earthquakes. The evolution of landforms affected by fault action is a dominant issue in geological science. In the present study, was selected the 20 km long Xilokastro pure normal fault. In this fault, we apply eight geomorphological indices in footwall catchments that drain perpendicular to its trace. In total, more than 5000 measurements were made in 102 catchments. The determination of geomorphological indices requires the construction of morphological profiles either perpendicular to the faults or perpendicular to the main tributaries of the drainage basins under consideration through the use of the geographical information systems (ArcGIS platform). Τhe application of these indices along catchments draining the Xilokastro fault scarp show high active tectonics. Its high activity is evidenced by the high values of the length-slope index near the fault trace, the low values of the width to height ratio index, the strong asymmetry of the drainage basins, especially in the overlapping zones between its segments, and the elongated shape of the drainage basins. This study supports the idea that the application of a single morphometric index is unable to reflect the distribution of active tectonics across faults, which makes inevitable the systematic comparison of a series of tectonic morphometric indices from which a new combined index emerges (Iat). The Iat classifies the Xilokastro fault in the high degree of activity at a rate of 75% of its length.

Highlights

The evolution of tectonically controlled landforms and the way active tectonics of an area are imprinted has caused a great deal of research by and discussion among the scientific community [1]
Understanding the geometry of faults, the interaction between faults, and the sensitivity of river systems to tectonic movements becomes extremely important in determining the active tectonics of an area [2,3,4,5,6]
The use of geomorphological methods in areas of active tectonics, which are associated to strong seismicity, leads to conclusions and quantifies the changes in the terrain along a fault, and it can be an indication of the slip rate in an active fault

Summary

Introduction

The evolution of tectonically controlled landforms and the way active tectonics of an area are imprinted has caused a great deal of research by and discussion among the scientific community [1]. The use of geomorphological methods in areas of active tectonics, which are associated to strong seismicity, leads to conclusions and quantifies the changes in the terrain along a fault, and it can be an indication of the slip rate in an active fault. The existence of many faults of normal geometry in its southern margin is “responsible” for the impressive topography in the gulf [10,11,12]. The intense tectonic activity ensures conditions required for capturing tectonic movements in landforms. By this way the landforms become “able” to provide data on the tectonic evolution of an area for both short-term and long-term observation periods

Objectives

Methods

Results

Discussion

Conclusion