Suchergebnisse

Intro -- Preface -- Introduction -- References -- Contents -- Part I The Role of NATO -- 1 NATO Cooperation with Georgia in the Framework of the Science for Peace and Security (SPS) Programme -- 1.1 The Science for Peace and Security (SPS) Programme -- 1.2 SPS Cooperation with Georgia -- 1.3 Securing Georgia and the Caucasus Against Geohazards -- 1.4 Conclusion -- 2 Lens on NATO-Georgia Cooperation: A Shared Engagement -- 3 An Overview of the 20-Year Collaboration Between NATO and Earth Scientists to Assess Geohazards in the Caucasus and Other Critical Regions -- 3.1 Introduction -- 3.2 Project CLG 982957 - Volcanic Hazards and Countermeasures for Georgian Section of Caspian Pipelines -- 3.2.1 Summary of the Project -- 3.2.2 Why this Project -- 3.2.3 Outcomes -- 3.3 Project G4934 - Security Against Geohazards at the Major Enguri Hydroelectric Scheme in Georgia -- 3.3.1 Summary of the Project -- 3.3.2 Why this Project -- 3.3.3 Outcomes -- 3.4 Project SFP 983142 - Geo-Environmental Security of the Toktogul Hydroelectric Power Station Region, Central Asia -- 3.4.1 Summary of the Project -- 3.4.2 Why this Project -- 3.4.3 Outcomes -- 3.5 CLG Project 978989 - A Multidisciplinary Approach to Recent Geologic Catastrophes at Subduction Zones -- 3.5.1 Summary of the Project -- 3.5.2 Why this Project -- 3.5.3 Outcomes -- 3.6 Discussion and Final Remarks -- References -- Part II Key Studies Focused on Regional and Geological Aspects -- 4 Active Kinematics of the Greater Caucasus from Seismological and GPS Data: A Review -- 4.1 Introduction -- 4.2 Main Tectonic Features of Greater Caucasus -- 4.3 Seismicity of the Greater Caucasus -- 4.3.1 Source of Data -- 4.3.2 Epicentre Distribution -- 4.3.3 Hypocentres Distribution -- 4.3.4 Focal Mechanism Solutions -- 4.3.4.1 Data Source -- 4.3.4.2 FMS Results -- 4.3.5 Stress Distribution -- 4.4 GPS Data.

Abstract. The Enguri dam and water reservoir, nested in the southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that affect a subaerial area of 1.2 km2. The head scarp affects the Jvari–Khaishi–Mestia main road with offsets of man-made features that indicate slip rates of 2–9 cm yr−1. Static, pseudostatic and Newmark analyses, based on field and seismological data, suggest different unstable rock volumes based on the environmental conditions. An important effect of variation of the water table is shown, as well as the possible destabilization of the slope following seismic shaking, compatible with the expected local peak ground acceleration. This worst-case scenario corresponds to an unstable volume on the order of up to 48±12×106 m3. The opposite, eastern slope of the same mountain ridge is also affected by wide deformation affecting an area of 0.37 km2. Here, field data indicate 2–5 cm yr−1 of slip rates. All this evidence is interpreted as resulting from two similar landslides, whose possible causes are discussed, comprising seismic triggering, mountain rapid uplift, river erosion and lake variations.