Publication information

Geological Survey of Canada
Open File 8436

Site corrections and residual analysis for seismograph stations used for magnitude calculations 
in eastern Canada

A. L. Bent

© Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources, 2019

Permanent link: https://doi.org/10.4095/314747

Publications in this series have not been edited; they are released as submitted by the author.

Recommended citation

Bent, A.L., 2019. Site corrections and residual analysis for seismograph stations used for magnitude calculations in eastern Canada; Geological Survey of Canada, Open File 8436, 1 .zip file. https://doi.org/10.4095/314747

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Contents

Earthquake magnitudes are generally determined by taking an average of magnitudes calculated at many individual seismograph stations.  Conditions beneath the recording station affect the calculated value.  For example, soft soils tend to amplify the seismic signal resulting in an apparent magnitude that is higher than the true value.  By analyzing the differences between the magnitude determined at a specific station and the average magnitude for a large number of earthquakes, a site correction for the station can be determined and then applied as part of the magnitude calculation.  Station corrections have been determined for more than three hundred seismographs used in the calculations of magnitudes in eastern Canada.  The station corrections are summarized,  applied and the resultant residuals analyzed for any dependence of factors, such as distance or azimuth.  Corrections for most stations are close to 0.0 but there are several stations for which the correction is significant.    The text describes the analysis in detail.   The tables summarizing the corrections are also provided as spreadsheets. 

Directory structure

of_8436.pdf
of_8436_table1.xlsx
of_8436_table2.xlsx

Author contact information

Allison Bent (allison.bent@canada.ca)
Geological Survey of Canada
7 Observatory Crescent
Ottawa, Ontario
 K1A 0Y3

Availability information

This publication is available for free download through GEOSCAN (https://geoscan.nrcan.gc.ca/).

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