00000nam 2200000za 4500 9.856878 CaOODSP 20251031142447 cr ||||||||||| 180523s2018 oncbd ob f000 0 eng d CaOODSP eng n-cn--- M183-2/8232E-PDF Bent, Allison Lyn. Magnitudes at close and very close distances in eastern Canada [electronic resource] : issues and recommendations / A.L. Bent. [Ottawa] : Natural Resources Canada, 2018. 32 p. : charts (mostly col.), col. maps. Open file ; 8232 Includes bibliographical references (p. 18-20). "The MN magnitude scale used in eastern Canada is not defined for distances of less than 50 km. The ML scale is used instead, but its attenuation relations are not appropriate for eastern Canada. This study compares magnitudes at close and regional distances to develop a reliable conversion relation such that magnitudes from close stations can be objectively compared to magnitudes from more distant stations. The recommendation for routine use is that the MN scale be used for distances greater than 10 km but that a 0.11 magnitude unit correction be applied for distances of 10-50 km. These corrections allow magnitudes to be calculated from a higher number of stations and may increase the magnitude range used for seismic hazard assessments. Magnitudes from stations at distances less than 10 km should not be used unless the earthquake was too small to be recorded at greater distances. In this case, the correction for 10-50 km should be applied but it should be noted that the resulting magnitude may not be accurate"--Provided by publisher. Earthquake magnitude Measurement Canada, Eastern Canada. Natural Resources Canada. Geological Survey of Canada. Open file (Geological Survey of Canada) 8232. (CaOODSP)9.506878 PDF 2.08 MB https://publications.gc.ca/collections/collection_2018/rncan-nrcan/m183-2/M183-2-8232-eng.pdf 308131