First Application of the New IASPEI Teleseismic Magnitude Standards to Data of the China National Seismographic Network

Reply to "Comment on `A Homogeneous and Complete Earthquake Catalog for Northeast India and the Adjoining Region' by R. B. S. Yadav, P. Bormann, B. K. Rastogi, M. C. Das, and S. Chopra" by R. Das and H. R. Wason

“…The same trend change with comparable slopes was found by Bormann et al (2009) between M w , HRVD and IASPEI standard M S (20) measured at the Chinese national seismic broadband network for globally distributed earthquakes in the distance range 20° to 100°. However, in contrast to the above relationships, Bormann et al (2009) calculated orthogonal regressions that correctly assume that both types of correlated magnitudes are afflicted by comparably large errors Castellaro and Bormann 2007): , which runs out of the cloud for values M S > 6.2.…”

“…This explains why National Earthquake Information Center (NEIC) or ISC m b data published in the past saturated already in the range between about 6.2 and 7, depending also on the time window of measurement which varied from initially 5 s to 10-20 s later and rarely up to 60 s for the strongest earthquakes only (see Bormann et al 2007 Gupta et al (1986), then these would most likely be m B and not m b data. Abe (1981) Gutenberg and Richter 1956;Bormann et al 2009). 10.…”

“…Such a small difference cannot explain the very large difference in effects. Calculating M w proxies with the global Scordilis (2006) M w -M S relationships for 6.2 ≤ M S ≤ 8.2, which is very large in data (almost 26,000 data points) with reasonably low standard deviation of 0.20, and the global M w -m b relationship for 4.5 < m b < 7.5 published by Bormann et al (2009), one gets for the first earthquake M w (m b ) = 6.0 and M w (M S ) = 6.5, and thus an average M w proxy of 6.2. For the second earthquake the respective values would be M w (m b ) = 7.3 and M w (M S ) 6.8, corresponding to an average of about 7.0.…”

“…For comparison, we choose the most comprehensive study by Scordilis (2006), which is based on tens of thousands of magnitude data published in the International Seismological Centre (ISC), the National Earthquake Information Center (NEIC) of the U.S. Geological Survey (USGS), and the Harvard Centroid-Moment Tensor (HRVD) catalogs between 1965 and 2003, and results published by Bormann et al (2009). In contrast to Scordilis (2006), the latter investigated for the first time …”

The Influence of Earthquake Magnitude on Hazard Related to Induced Seismicity

“…Indeed, such comparisons extend to many different magnitude scales (e.g., Bormann et al 2009). Careful initial calibrations nevertheless ensure that over a broad region of interest, earthquake magnitudes using different scales are consistent.…”