| Popis: |
In their article, Yadav et al. (2009) made two major approximations that have a significant impact on the estimates of Mw ,HRVD proxies for the catalog that they considered. The first approximation is to consider the unspecified magnitudes equivalent to MS ,ISC for all magnitude ranges, and the second relates to estimating Mw ,HRVD proxies as the average of the two M w,HRVD conversions wherever available both from mb ,ISC and MS ,ISC. They also used a small number of data pairs of Mw ,HRVD & MS ,NEIC and MS ,ISC & MS ,NEIC for estimating representative regional relationships to be used for corresponding Mw ,HRVD conversions. In this comment we examine the inaccuracy involved in these approximations and in correlations based on small sample sizes, and we propose improved regression relations and an alternative scheme for calculating the averages of Mw ,HRVD proxies. For the period 1897 to 1962, magnitudes are not specified for about 186 … |
