Relationship between macroseismic intensity and instrumental seismic intensity for Korean earthquakes

Abstract

It is important to assess damage by region and to communicate the information with relevant organizations in earthquake response. Timely and reliable information minimize public confusion and reduce unnecessary effort. Seismic intensity is the representative information related to earthquake damage. It is classified into macroseismic intensity and instrumental seismic intensity. Korea is in different earthquake environment from overseas. Therefore, it is required to improve seismic intensity assessment system suitable for Korea. It should be improved in two aspects. One is related to improving the description of macroseismic intensity, and the other is related to developing the macroseismic-intensity- prediction model. The former is researched separately, and the latter was researched in this thesis. Correlation analysis between macroseismic intensity(observed MMI) and 4 kinds of instrumental intensities were performed. Housner spectral intensity showed the highest correlation coefficient and was used for regression analysis to develop MMI prediction model. Proposed model provides more improved information than before, despite its limited applicability(MMI < 6 and epicentral distance 140km). Most cases will be in that condition, because Korean earthquakes are usually small-to-moderate. Stronger earthquake data of overseas, which are in intra-plate similar to Korea, would help to supplement the model in the future research.