This study focuses on rapidly determining seismic intensity maps of earthquakes because it offers fundamental information for effective emergency rescue and subsequent scientific research, and remains challenging to accurately determine seismic intensity map in regions with sparse instru- mental observations. Here we applied a novel method that consisted of array technology (back- projection), ground-motion prediction equations, and site corrections, to estimate the seismic intensity maps of the 2021 Mw 7.3 Madoi, Qinghai and the Mw 6.1 Yangbi, Yunnan, China earthquakes. We used seismic data recorded at European stations to back-project the source processes of the 2021 Mw 7.3 Madoi, Qinghai and the Mw 6.1 Yangbi, Yunnan, China earthquakes. The back-projected energy ra- diations were then used as subevents or used to define the fault geometry. Summing the contributions of each subevent or estimating the shortest distances from each site to the rupture fault, we obtained the ground motion (PGA and PGV) for each site under rock site conditions. The estimated ground motions were corrected at each site for local site amplification according to the Vs30 database. Our estimated seismic intensity maps and field reports showed high similarity, which further validated the effective- ness of the novel approach, and pushed the limit of earthquake size down to～M 6. Such efforts would substantially help in the fast and accurate evaluation of earthquake damage, and precise rescue efforts.

Wenkai Chen;Dun Wang;Can Zhang;Qiang Yao;Hongjun Si

Lanzhou Institute of Seismology,China Earthquake Administration,Lanzhou 730000,China;State Key Laboratory of Geological Processes and Mineral Resources,School of Earth Sciences,China University of Geosciences,Wuhan 430074,China;Seismological Research Institute Inc.,Tokyo 113-0032,Japan

地球科学学刊（英文版）

[1]Wenkai Chen;Dun Wang;Can Zhang;Qiang Yao;Hongjun Si-.Estimating Seismic Intensity Maps of the 2021 Mw 7.3 Madoi, Qinghai and Mw 6.1 Yangbi, Yunnan, China Earthquakes)[J].地球科学学刊（英文版）,2022(04):839-846

diations,subevents,Summing,subevent

Estimating,Seismic,Intensity,Maps,Mw,Madoi,Qinghai,Yangbi,Yunnan,China,Earthquakes,This,study,focuses,rapidly,determining,seismic,intensity,maps,earthquakes,because,offers,fundamental,information,effective,emergency,rescue,subsequent,scientific,research,remains,challenging,accurately,determine,regions,sparse,instru,observations,Here,applied,novel,method,that,consisted,array,technology,back,projection,ground,prediction,equations,site,corrections,We,used,recorded,European,stations,source,processes,projected,energy,were,then,define,fault,geometry,contributions,each,estimating,shortest,distances,from,rupture,obtained,PGA,PGV,under,rock,conditions,estimated,motions,corrected,local,amplification,according,Vs30,database,Our,field,reports,showed,high,similarity,which,further,validated,ness,approach,pushed,limit,size,down,Such,efforts,would,substantially,help,fast,evaluation,damage,precise

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