The use of spectral content to improve earthquake early warning systems in Central Asia; case study of Bishkek, Kyrgyzstan

Expansion of urban areas in Central Asia increases their exposure to seismic hazard, but at present no earthquake early warning (EEW) systems exist in the region. Such systems, successfully implemented in other regions, aim to provide warning of the order of tens of seconds about impending disasters, enabling the first rapid-response steps to be taken. The feasibility of such systems for Bishkek, Kyrgyzstan, has been demonstrated. This study investigates how the use of the spectral content, instead of just ground-motion thresholds, can be used to improve the performance of proposed regional warning systems. We find that using the spectral content of the first few seconds after the P-wave arrival can provide timely warning for events closer to the target city than was possible with the threshold systems. It is further shown that for events less than 60 km from the target, any regional system needs to be complemented with an onsite one to provide a comprehensive EEW system.