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Abstract Iran is located in a seismic prone region along Alpine-Himalaya Orogenic belt. Along two main mountain ranges of Alborz and Zagros in the country (in north and west parts of Iran, respectively) several active faults exist, that are the roots of many destructive earthquakes occurred during the recent decades such as Manjil (1990), Awaj (2002), Firouz Abad-Koujour (2004), Silakhor (2006) and recentlyVarzaghan (2012) Earthquakes. Most of these events were associated with some types of landslides and rock-falls, due to topography of the affected regions. In this paper, having a look on the causes and impacts of these earthquakes, different types of the slope instabilities observed or reported after each event will be introduced and discussed. In addition, the impacts of landslides on post-earthquake activities such as emergency response and reconstruction of the damaged areas will be presented. Finally having a look on socio-economic impacts of these geological instabilities, some recommendation will be presented to be applied for reducing the impacts of those hazards that can be applied in Iran and other countries facing similar challenges.
Introduction Many destructive earthquakes have been occurred in Iran during its history, due to its geological condition and existing numerous active faults extended at different parts of the country; the major ones are shown in Figure 1.
Seismicity studies show that the country will undoubtedly experience large earthquakes in the future; averagely in each year one seismic event with magnitude higher than 6.0 and every ten years an event with magnitude of about 7.0 (Amini Hosseini et al., 2009).
In most of the recent seismic events in Iran and all around the world, some types of geological hazards were also triggered by ground shaking that caused further damages and casualties. As example, the Tohoku, Japan Earthquake (2011) triggered many landslides that caused further destruction of buildings and infrastructure (Higaki et al., 2011). Landslides triggered by Padang, Indonesia Earthquake (2009) are another example that caused about 600 deaths in hillside of the Padand Pariman district in West Sumatra. This is almost equal to the number of casualties of collapsed buildings by ground shaking (Vigny, 2009). Similar impacts of landslides and rock-falls can be also found in Port au Prince, Haiti (2010), Sichuan, China (2008) some types of landslide or rock-fall. In some seismic events in Iran, the damages of such instabilities were much higher than the ground shaking. Therefore, during the recent years the impacts of such ground failures were also studied and some guidelines and plans have been developed to reduce their impacts. In this paper, having a look on the damages of slope instabilities associated with recent earthquakes in Iran, the existing conditions on geo-hazards risk mitigation and management activities in Iran will be reviewed and discussed.
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