[S05-1] Preservation and usage of analog seismogram archives I

[S05-1-04] A brief introduction to the analog seismograms storage in China

^○Ruifeng Liu, Leiyu Mou (Institute of Geophysics, China Earthquake Administration, Beijing, China)

invited

From 1950 to 1980, China Earthquake Administration(CEA) finished the construction of National Seismic Network with 86 stations, among them 24 stations equipped with short period seismograph, broad band seismograph and long period seismograph, and 62 stations equipped with short period seismograph. From 1996, supported by the central government and local governments, CEA launched national projects of updating the seismological observation facilities into digital seismological observation systems. By the end of 2007, CEA had accomplished analog to digital conversion of the then existing seismological observation systems and set up 1007 digital seismic stations. This indicates full digitization of seismological observation in China.
From 1950 to 2007, CEA accumulated a huge mass of analog seismograms, some seismographs are stored in Institute of Geophysics, and some seismographs are stored in provincial seismological earthquake administration. Due to storage in different regions, some seismograms have been damaged or lost. We must sort through these valuable historical seismograms and input to computer timely for proper record.
CEA pay more attention to analog seismograph rescure, we scanned about 40,000 seismographs with 600 dpi in jpg format in 2015. With the helps of Prof. Paul Richards and Dr. Won-Young Kim, we installed the analog seismograph digital software SeisDig and digitized some seismographs in 2016. SeisDig is a Graphical User Interface (GUI) based interactive digitizing tool, digitizing operations are mouse selected.