1Institute of Geophysics, China Earthquake Administration (CEA), Beijing, China
According to the calculation, the latest nuclear explosion that occurred in North Korea had the largest energy at the frequency of 0.1-3 Hz, and in the frequency higher than 3 Hz, the latest event had the same energy with the one in January 2016, the one in 2013 and even the one in 2009. At 2 Hz, the ratio of the event that occurred in September 2016 to the other four events are 40.1, 4.7, 2.0, and 1.8 respectively, which have little difference with the results of the Wen Lianxing（2016） group, who gave yields of 17.8kt, 11.3kt, 12.2kt, 7kt, and 0.48kt for the five events, and the ratios are 37.1, 2.5, 1.5, and 1.6 respectively. According to the calculation, the maximum coefficients of E1609 and E06, E09, E13, E16 is 0.88, 0.98, 0.94, and 0.98 in the vertical direction. According to the analysis using the Fuqing array and the Zhangzhou array in China and the research results of Ingate (1985) and Ringdal (1982), we concluded that the aperture of the five events is no larger than 3km, the distance between the latest two events is no longer than 1km.
Start time: 28/Jun/2017, 09:00 (local time)
Duration: 15 minutes
Location: Hofburg, Zeremoniensaal, Wintergarten, Marmorsaal