Historical geological catastrophes in Northern Kyrgyzstan
Impacts of natural catastrophes on ethno-cultural development in Northern Kyrgyzstan
Tech Area / Field
- ENV-SEM/Seismic Monitoring/Environment
3 Approved without Funding
Institute of Geology of NAS of Kyrgyzstan Republic, Kyrgyzstan, Bishkek
- University of Texas at El Paso, USA, TX, El Paso\nUniversity of Milan, Italy, Milan
Project summaryProject scope: explore and excavate ground archaeological sites and identify and map submerged archaeological sites along seismically active zones in Northern Kyrgyzstan located along mountainous rim of the Issyk-Kul Basin and Chui and Talas Valleys to collect data on ancient geological catastrophes and their impacts on human activity at the sites under study; collect and analyze data on ancient geological catastrophes traced within explored sites and apply research findings to forecast the periodicity and assess geo-hazards in the region.
Rationale: Northern Kyrgyzstan is one of the country’s most densely populated regions, many towns and villages, touristic places, health facilities and resorts. The country’s capital, Bishkek, with population of more than a million is also located here. However, the region is seismically active and prone to geo-hazards, such as landslides, mudflows, sudden water level changes in Lake Issyk-Kul, etc. The region has witnessed a number of very strong, catastrophic earthquakes with magnitude ≥7 (7.0 magnitude Belovodsk earthquake in 1885, 8.2 magnitude Kemin earthquake in 1911, 6.9 magnitude Kemin-Chui earthquake in 1938, 6.9 magnitude Sary-Kamysh earthquake in 1970, 6.5 magnitude Jalanash-Tyup earthquake in 1978, 6.1 magnitude Baisoorun earthquake in 1990). The Belovodsk earthquake caused many large rockslides in the Sokuluk river basin, while the best-known earthquake-triggered landslide is the Ananyevo rockslide that occurred on the southern slope of the Kungey Range during the Kemin earthquake and involved the failure of 350 million cubic meters of rock and earth. Mudflow hazards in Northern Kyrgyzstan are associated with mountain rivers. Snow melting and heavy rainfalls in narrow mountain ravines turn mountain streams into strong torrents that lift and carry debris and stones from the valley slopes and floor. In particular, heavy rains in 2003 caused a mudflow in the Ala-Archa river valley that destroyed bridges, washed out the asphalt road, damaged several buildings in a nearby holiday village and even killed a man—the village’s security guard.
It should be noted that Soviet-time radioactive waste disposal facilities are still present on the southern shore of Lake Issyk-Kul (near Kadji-Sai Village) and in the Kichi-Kemin River Valey (northern tributary of the Chui River). The tailings impoundments are in extremely poor condition: radioactive wastes are stockpiled on fragments of alluvial terraces or in dry stream channels. The protective dams are washed out or damaged and cannot function properly. During rainfalls or snow melt periods, radioactive wastes are carried away with rain or melt water into Lake Issyk-Kul and the Chui River, which is used for irrigation and household needs by population of two countries: Kyrgyzstan and Kazakhstan. Strong earthquakes and earthquake-triggered landslides and mudflows in the tailings impoundment areasmaycause environmental catastrophes (including transboundary ones).
Strong earthquakes, significant landslides and catastrophic mudflows are also expected in the future. This is why an accurate assessment of hazards and risks of geological catastrophes for this densely populated region requires building a large and chronologically long GIS database. However, reliable written sources mentioning such earthquakes are dated to no earlier than the mid of the 19th century. There had been no local writing tradition in the region until then, and existing external sources are not informative in this respect. This is the reason why geoarcheological archaeoseismic and paleoseismic studies are the only way to expand the regional database of past geo-catastrophic events. These methods will ultimately allow the reconstruction of the history of past natural processes.
Paleoseismic methods will help study the structure of seismically active fault zones and related seismic displacements. The next phase will be the identification and mapping of archaeological sites along seismically active fault zones in Northern Kyrgyzstan followed by excavation of project-specific sites to collect data for further analysis of ancient geo-catastrophes. An underwater archaeological survey will be carried out in parallel and will consist of exploration of submerged archaeological sites and sample collection for absolute dating. This effort will also allow the team to study and plot the evolution of Issyk-Kul Lake’s shoreline over the historical period. The final phase will include computer modeling of past geological catastrophes and correlation of forecasts based on newly collected data, and also production of data that will help assess geo-hazards and in Northern Kyrgyzstan.
The project relies on archaeological, archeo-seismic and paleo-seismic experience gained in international projects and confirmed by paper presentations at various conferences and publications in scientific journals (see clause 12 Additional Information) as well as on the global experience and world’s best practices (Archaeoseismology, 1996; Paleoseismology, 1996, 2009; The Archaeology of Geological Catastrophes, 2000; Archaeoseismology at the Beginning of the 21st Century, 2006 and many others). The experience of the weapons science, in particular in connection with deformations and failures under dynamic loading and seismic modeling, will be also used in some of the studies and field data analysis. The knowledge of the project team is expected to be sufficient to comprehensively address geological catastrophes and enable a reliable geo-hazard assessment of the Northern Kyrgyzstan.