Investigation ofmbandMSformulas for the Western United States and their impact on theMS/mbdiscriminant
| Autor: | Marvin D. Denny, Steven R. Taylor, Eileen S. Vergino |
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| Rok vydání: | 1987 |
| Předmět: | |
| Zdroj: | Bulletin of the Seismological Society of America. 77:987-995 |
| ISSN: | 1943-3573 0037-1106 |
| DOI: | 10.1785/bssa0770030987 |
| Popis: | The impact of regional mb and MS formulas on regional MS/mb discrimination is investigated using a large number of Western United States earthquakes and explosions. Comparison of NEIS mb values with regional mb values shows a systematic error of 1.2. Additionally, a simple analysis of variance shows that the variance of the magnitude estimate is reduced when log(A) replaces log(A/T). These changes, along with a refinement of the distance correction, yield a new regional mb for the Western United States given by mb = log(A) + 2.4 log(Δ) − 3.95 + cj, where A = 0 to peak amplitude in nanometers, Δ is the distance in kilometers, and ci is a station correction. Usage of this formula improves the performance of regional MS/mb discrimination by a factor of 2 to 6. |
| Databáze: | OpenAIRE |
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