F26 GIRS Seminars: The Seimare Giant Rock Avalanche, Iran: Lessons from the Past and Implications for Future Landslide Hazards

📅 When: Thursday, November 19, 2026
🕐 Time: 1:00–2:00 PM PT
📍 Where: (In-Person) Engineering 6 Building, Room 580B and 💻 ZOOM

Habib Shahnazari, Ph.D., P.E., Int. PE (APEC)

headshot of Dr. Habib shahnazari

Abstract: Recent disasters, such as the devastating landslides and floods in Nepal, remind us how destructive natural hazards can be, affecting communities, damaging infrastructure, and triggering additional hazards. Understanding these events is essential to reducing future risks.

The Seimare rock avalanche in the Zagros Mountains of southwestern Iran is considered the largest known non-volcanic landslide on land. Around 10,000 years ago, an enormous section of a mountainside collapsed, sending massive volumes of rock downslope, blocking a river, forming a natural dam, and reshaping the landscape. Although an earthquake may have triggered the collapse, the exact cause remains uncertain.

This presentation will examine the geological conditions, geometry, and failure mechanism of the Seimare landslide, along with findings from deterministic and probabilistic seismic hazard analyses. It will also address the potential for future instability along the margins of the ancient landslide and the associated risks to nearby communities and infrastructure.

Studying Seimare helps us understand how massive landslides develop, the possible role of earthquakes, and how lessons from the past can improve future hazard assessments and help protect lives and property.

Short Bio: Habib Shahnazari is the Founder and CEO of Geotekra LLC and a Research Affiliate at the UCLA Garrick Institute for the Risk Sciences. Uniquely bridging academia and industry, his expertise spans seismic hazard analysis, slope stability, and complex geotechnical risk assessment, backed by an extensive record of peer-reviewed publications. With a Ph.D. in Geotechnical Engineering from the University of Tokyo, he previously served as a professor and the Director of the Geotechnical Engineering Research Center (GERS) at the Iran University of Science and Technology. He is a licensed Professional Engineer in Nevada and British Columbia, and holds the International Professional Engineer (Int. PE, APEC) designation.