Active Global Seismology

Neotectonics and Earthquake Potential of the Eastern Mediterranean Region

Ibrahim Cemen, Yucel Yilmaz

• Publisher: American Geophysical Union
• Year: 2017
• ISBN:
  9781118945001
• Edition: 1
• Topic: Ciencias físicas
• Subtopic: Geología y ciencias de la Tierra

Neotectonics involves the study of the motions and deformations of the Earth's crust that are current or recent in geologic time. The Mediterranean region is one of the most important regions for neotectonics and related natural hazards. This volume focuses on the neotectonics of the Eastern Mediterranean region, which has experienced many major extensive earthquakes, including the devastating Izmit, Turkey earthquake on August 17, 1999. The event lasted for 37 seconds, killing around 17, 000 people, injuring 44, 000 people, and leaving approximately half a million people homeless. Since then, several North American, European, and Turkish research groups have studied the neotectonics and earthquake potential of the region using different geological and geophysical methods, including GPS studies, geodesy, and passive source seismology. Some results from their studies were presented in major North American and European geological meetings.

This volume highlights the work involving the Eastern Mediterranean region, which has one of the world's longest and best studied active strike-slip (horizontal motion) faults: the east-west trending North Anatolian fault zone, which is very similar to the San Andreas fault in California. This volume features discussions of:

• Widespread applications in measuring plate motion that have strong implications in predicting natural disasters like earthquakes, both on a regional and a global scale
• Recent motions, particularly those produced by earthquakes, that provide insights on the physics of earthquake recurrence, the growth of mountains, orogenic movements, and seismic hazards
• Unique methodical approaches in collecting tectonophysical data, including field, seismic, experimental, computer-based, and theoretical approaches.

Active Global Seismology is a valuable resource for geoscientists, particularly in the field of tectonophysics, geophysics, geodynamics, seismology, structural geology, environmental geology, and geoengineering.

Read an interview with the editors to find out more:
https://eos.org/editors-vox/neotectonics-and-earthquake-forecasting

1
Neotectonics and Earthquake Potential of the Eastern Mediterranean Region: Introduction

İbrahim Çemen¹ Yücel Yılmaz²

¹ Department of Geological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA

² Department of Geological Engineering, İstanbul Technical University, İstanbul, Turkey

1.1. INTRODUCTION

Neotectonics is a subdiscipline of tectonics and involves the study of recent motions and deformation of the Earth's crust. These recent motions, particularly those produced by earthquakes, can provide insights on the physics of earthquake recurrence, the growth of mountains, orogenic movements, and the seismic hazard. This volume focuses on neotectonics of the eastern Mediterranean region (Figure 1.1), which has experienced many major devastating earthquakes throughout its recorded history. A major devastating earthquake in the region occurred at 3:02 a.m. on 17 August 1999 in Izmit, Turkey (Mw = 7.4), lasted for 37 sec, killed around 17,000, injured 44,000 people, and left approximately half a million people homeless. Economic loss due to this earthquake is estimated at around $20 billion. Since the Izmit earthquake, several North American, European, and Turkish research groups have been studying the neotectonics and earthquake potential of the eastern Mediterranean region by using different geological and geophysical methods, including GPS studies, geodesy, and passive source seismology. Some results from these studies were presented in major North American and European geological meetings and published in major earth science journals. However, the first comprehensive collection of research case studies of this region was convened by the editors of this book at the 2013 AGU fall meeting in San Francisco, California, USA, which included 8 oral and 12 poster presentations. This book is a collection of the research that was presented at the meeting.

Figure 1.1 Digital elevation map of the eastern Mediterranean region showing major neotectonics structural features, volcanic centers (red triangles), and epicenters of the earthquakes (M > 5.0) since 1950. A = Ankara; EAFZ = East Anatolian fault zone; EF = Ecemis fault; I = Istanbul; MM = Menderes Massif; NAFZ = North Anatolian fault zone; T = Thessaloniki; TGF = Tuz Golu fault.

The eastern Mediterranean region is one of the most dynamically complex and seismically active neotectonic settings on Earth (Figure 1.1). It includes the following major geographic divisions: the Aegean Sea region, the Anatolian Peninsula, and the northern part of the Arabian Peninsula. Each of these geographic domains corresponds to a distinctly different and composite tectonic entity.

The Anatolian Peninsula is part of the Alpine‐Himalayan orogenic belt. Along its northern and southern edges lie approximately E‐W trending mountain ranges known as the Pontides (the northern range) and the Taurides (the southern range). In Anatolia, the orogeny started in the north, migrated progressively to the south, and ended up in the Bitlis‐Zagros orogenic belt. Following the latest phase of the collision along the Bitlis‐Zagros suture, the Arabian Plate continued moving northward and generated a north‐directed contraction (Figure 1.1). Consequently, the East Anatolian crust and lithosphere have been thickened, and the region was elevated to form the East Anatolian‐Iranian high plateau. This shortening gave way to the formation of the North Anatolian and East Anatolian fault zones (Figure 1.1). The initiation of the two fault zones is generally considered as the beginning of neotectonics in Anatolia and surrounding regions.

Neotectonics of the eastern Mediterranean region is dominated by the African Plate subduction along the Hellenic and Cyprus trenches, collision between the Anatolian and Eurasian plates, and westward extrusion of the Anatolian Plate along the north and east Anatolian fault zones [Sengor and Yilmaz, 1981; Sengor et al., 1985; Robertson and Dixon, 1984; Çemen et al., 1999, 2006; Aksu et al., 2005]. The convergent zones are characterized by deep earthquakes along the Hellenic and western segment of the Cyprus arcs [Di Luccio and Pasyanos, 2007], volcanism [Pe‐Piper and Piper, 2006; 2007; Altunkaynak and Dilek, 2006; Prelević et al., 2012; Jolivet et al., 2013], large‐scale continental extension [Faccenna et al., 2003; Çemen, 2010; and Ersoy et al., 2014], uplift [Schildgen et al., 2012; 2014], trench retreat, slab tear, and slab detachment [Faccenna et al., 2006; Biryol et al., 2011; Hall et al., 2014]. The extension and uplift are related to the southwest retreating Hellenic trench and westward movement of the Anatolian Plate [Çemen et al., 2006 and 2014; Reilinger et al., 2010; Cosentino et al., 2012; Schildgen et al., 2014].

This book contains nine chapters covering a wide range of contributions to the neotectonics and earthquake potential of the eastern Mediterranean region. The chapters cover an extensive and overlapping tectonic mosaic of new data that contribute significantly to our understanding of the crustal and lithospheric behavior manifested by tectonic, seismotectonic, and morphotectonic elements in the region.

The chapters are organized under the following thematic groups.

1.1.1. Part I: Morphotectonic Characteristics of Neotectonics in Anatolia and Its Surroundings

Two chapters are in this section of the book.

1.1.1.1. Chapter 1. Morphotectonic Development of Anatolia and the Surrounding Regions by Yücel Yılmaz

This chapter may be regarded as a tectonic backbone of the book in the sense that it covers tectonic framework of Anatolia and its surroundings. Several local and regional morphological studies were conducted on different parts of Anatolia. However, this chapter is the first attempt to encompass morphological treatment of the whole Anatolian peninsula to evaluate interactions of morphotectonically different regions and major tectonic elements, and along this direction it provides a platform for similar future studies.

The chapter's major points are summarized as follows: Anatolia is being deformed presently under an ongoing severe post‐late orogenic tectonic regime, which is expressed by the GPS data; frequent earthquakes that occur in a vast terrain from the east to the west; and rugged, irregular, and tectonically controlled morphology. In order to understand the tectonics of Anatolia, structural analyses of the tectonically different regions and the earthquakes are studied extensively using a variety of methods and techniques. but the morphotectonic features that are also equally important are commonly ignored. Therefore, this chapter is complementary to most of the structurally and tectonically oriented regional and local treatments.

Anatolia and the surrounding regions contain a number of morphotectonic subdivisions including the East Anatolian‐Iranian high plateau. The other subdivision are the peripheral mountain ranges (the Pontides and Taurides), the central Anatolian plateau, and the western Anatolian extensional region. They have all essentially formed during the Neotectonics period. Therefore, a critical period in the geologic‐tectonic and particularly morphotectonic history of the region corresponds to a change from the Paleotectonic to Neotectonic periods. This chapter first addresses the timing and cause of the transition between these periods for each tectonic subdivision of the region, and then discusses at length morphotectonic character and characteristic features of each of the morphotectonic subdivisions, starting from the northwestern edge of the Arabian Peninsula around the Bitlis‐Zagros suture mountains because this belt is the latest product of the Anatolian Orogen that formed as a result of the collision between the Arabian and Anatolian plates. The northward advance of the Arabian Plate continuing after the collision generated a north‐directed severe contraction to push Anatolia northward. The N‐S contraction initially deformed eastern Turkey. East and central Anatolia began to rise together. In this, slab break off of the northerly subducting plate and lithospheric delamination played a significant role. The contraction then formed the North and East Anatolian transform faults. These faults border the Anatolian Plate, which began escaping to the west. Major morphotectonic features, the peripheral mountains (the Pontides and Taurides) and the western Anatolian extensional region, have evolved together with the transform faults, which played an important role in transfer of the stress in the region.

Compared to the east, the western of Anatolia has followed a different path of morphotectonic development. The region was a high lan...

Table of contents

• COVER
• TITLE PAGE
• TABLE OF CONTENTS
• CONTRIBUTORS
• PREFACE
• 1 Neotectonics and Earthquake Potential of the Eastern Mediterranean Region: Introduction
• Part I Morphotectonic Characteristics of Neotectonics in Anatolia and Its Surroundings
• Part II Neotectonics of the Aegean‐Western Anatolian Region
• Part III Seismotectonics in the Eastern Mediterranean Region
• INDEX
• END USER LICENSE AGREEMENT