Uncertainty estimates in broadband seismometer sensitivities using microseisms

Journal of Seismology
By: , and 

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Abstract

The midband sensitivity of a seismic instrument is one of the fundamental parameters used in published station metadata. Any errors in this value can compromise amplitude estimates in otherwise high-quality data. To estimate an upper bound in the uncertainty of the midband sensitivity for modern broadband instruments, we compare daily microseism (4- to 8-s period) amplitude ratios between the vertical components of colocated broadband sensors across the IRIS/USGS (network code IU) seismic network. We find that the mean of the 145,972 daily ratios used between 2002 and 2013 is 0.9895 with a standard deviation of 0.0231. This suggests that the ratio between instruments shows a small bias and considerable scatter. We also find that these ratios follow a standard normal distribution (R 2 = 0.95442), which suggests that the midband sensitivity of an instrument has an error of no greater than ±6 % with a 99 % confidence interval. This gives an upper bound on the precision to which we know the sensitivity of a fielded instrument.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Uncertainty estimates in broadband seismometer sensitivities using microseisms
Series title Journal of Seismology
DOI 10.1007/s10950-014-9467-7
Volume 19
Issue 2
Year Published 2015
Language English
Publisher Springer
Contributing office(s) Geologic Hazards Science Center
Description 11 p.
First page 317
Last page 327
Online Only (Y/N) N
Additional Online Files (Y/N) N