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Title: A Big Problem for Small Earthquakes: Benchmarking Routine Magnitudes and Conversion Relationships with Coda Envelope-Derived Mw in Southern Kansas and Northern Oklahoma

Journal Article · · Bulletin of the Seismological Society of America
DOI:https://doi.org/10.1785/0120210115· OSTI ID:1868860
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [5]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [3]; ORCiD logo [3]
  1. US Geological Survey, Golden, CO (United States). Geologic Hazards Science Center
  2. Air Force Technical Applications Center, Patrick AFB, FL (United States)
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  4. Univ. of Utah, Salt Lake City, UT (United States). University of Utah Seismograph Stations
  5. US Geological Survey, Moffett Field, CA (United States). Earthquake Science Center
+ Show Author Affiliations

Earthquake magnitudes are widely relied upon measures of earthquake size. Although moment magnitude (Mw) has become the established standard for moderate and large earthquakes, difficulty in reliably measuring seismic moments for small (generally Mw<4) earthquakes has meant that magnitudes for these events remain plagued by a patchwork of inconsistent measurement scales. Because of this, magnitudes of small earthquakes and statistics derived from them can be biased. Furthermore, because small earthquakes are much more numerous than large ones, many applications, such as seismic hazard modeling, depend critically on analysis of events characterized by magnitudes other than Mw. Therefore, to assess this problem, we apply coda envelope analysis to reliably determine moment magnitudes for a case study of small earthquakes from northern Oklahoma and southern Kansas. Not surprisingly, we find significant differences among ML, mbLg, and Mw for M ~2–4 earthquakes examined here. More troublingly, we find that relations designed to convert other magnitudes to Mw, which are relied upon for important applications such as seismic hazard analysis, often increase rather than decrease this bias for our dataset. In our case study, we find that converted magnitudes can result in a systematic bias sometimes exceeding 0.5 magnitude units, a difference that typically corresponds to a factor of ~3 in seismicity rate. Moreover, we find a correspondingly large bias in Gutenberg–Richter b-values, controlled primarily by inaccurate magnitude scaling in the conversion relationships. Although this study focuses on a relatively small geographic area, we can expect that similar issues exist with varying severity in other regions. Therefore, magnitudes of small earthquakes and their associated statistics, including seismicity rates and b-values, should be treated with caution.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF)
Grant/Contract Number:
AC52-07NA27344; EAR-1851048
OSTI ID:
1868860
Report Number(s):
LLNL-JRNL-833008; 1050737
Journal Information:
Bulletin of the Seismological Society of America, Vol. 112, Issue 1; ISSN 0037-1106
Publisher:
Seismological Society of AmericaCopyright Statement
Country of Publication:
United States
Language:
English

References (61)

A study of the relations between ML, Me, Mw, apparent stress, and fault aspect ratio journal January 2020
Earthquake stress via event ratio levels: Application to the 2011 and 2016 Oklahoma seismic sequences journal April 2017
Performance assessment of the induced seismicity traffic light protocol for northeastern British Columbia and western Alberta journal February 2018
Tectonic stress and the spectra of seismic shear waves from earthquakes journal September 1970
Source Spectral Properties of Small to Moderate Earthquakes in Southern Kansas: SOUTHERN KANSAS SOURCE SPECTRA journal October 2017
Reliability of Source Parameters for Small Events in Central Italy: Insights from Spectral Decomposition Analysis Applied to Both Synthetic and Real Data journal July 2020
Origin of coda waves: Source, attenuation, and scattering effects journal August 1975
Influence of pore-pressure on the event-size distribution of induced earthquakes: PORE PRESSURE AND EQ SIZE DISTRIBUTION journal May 2012
Real-time discrimination of earthquake foreshocks and aftershocks journal October 2019
Moment, energy, stress drop, and source spectra of western United States earthquakes from regional coda envelopes journal May 1996
Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable journal August 2017
Theoretical Basis for the Observed Break in M L / M w Scaling between Small and Large Earthquakes journal February 2017
Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3)--The Time-Independent Model journal June 2014
Moment-magnitude relations in theory and practice journal July 1984
Spectral models for ground motion prediction in the L'Aquila region (central Italy): evidence for stress-drop dependence on magnitude and depth journal December 2015
The energy release in great earthquakes journal July 1977
A new spectral ratio method using narrow band coda envelopes: Evidence for non-self-similarity in the Hector Mine sequence journal January 2007
Fluid-faulting evolution in high definition: Connecting fault structure and frequency-magnitude variations during the 2014 Long Valley Caldera, California, earthquake swarm: Fluid-Faulting Evolution in Long Valley journal March 2016
A Local Magnitude Relation for Earthquakes in the Western Canada Sedimentary Basin journal April 2017
The 2018 update of the US National Seismic Hazard Model: Overview of model and implications journal November 2019
An instrumental earthquake magnitude scale* journal January 1935
Toward Robust and Routine Determination of Mw for Small Earthquakes: Application to the 2020 Mw 5.7 Magna, Utah, Seismic Sequence journal January 2021
Brittle-ductile transition and associated seismicity: Experimental and numerical studies and relationship with the b value : BRITTLE-DUCTILE TRANSITION AND SEISMICITY journal January 2003
The standard error of the magnitude-frequency b value journal October 1982
Coda-derived source spectra, moment magnitudes and energy-moment scaling in the western Alps: Energy-moment scaling in the western Alps journal December 2004
On the Relationship between ML and Mw in a Broad Range: An Example from the Apennines, Italy journal January 2018
Spectral Analysis of K-NET and KiK-net Data in Japan, Part II: On Attenuation Characteristics, Source Spectra, and Site Response of Borehole and Surface Stations journal March 2011
Minimum Magnitude of Completeness in Earthquake Catalogs: Examples from Alaska, the Western United States, and Japan journal August 2000
Likelihood testing of seismicity‐based rate forecasts of induced earthquakes in Oklahoma and Kansas journal May 2016
Yield estimates of nevada test site explosions obtained from seismic Lg waves journal January 1986
Seismic moments, local magnitudes, and coda-duration magnitudes for earthquakes in central California journal April 1984
Seismic wave attenuation and magnitude relations for eastern North America journal February 1973
Monitoring the Earthquake Source Process in North America journal December 2011
Lg-Coda Methods Applied to Nevada Test Site Events: Spectral Peaking and Yield Estimation journal February 2009
A moment magnitude scale journal January 1979
Magnitude-based discrimination of man-made seismic events from naturally occurring earthquakes in Utah, USA: DISCRIMINATION OF MAN-MADE SEISMICITY journal October 2016
An Investigation of MbLg Versus Mw for Eastern North America journal May 2014
Analysis of earthquake body wave spectra for potency and magnitude values: implications for magnitude scaling relations journal September 2016
The frequency-magnitude relation of microfracturing in rock and its relation to earthquakes journal February 1968
Scaling Transition in Earthquake Sources: A Possible Link Between Seismic and Laboratory Measurements journal December 2013
The 2013–2016 Induced Earthquakes in Harper and Sumner Counties, Southern Kansas journal February 2018
Discrimination of Small Earthquakes and Buried Single-Fired Chemical Explosions at Local Distances (<150  km) in the Western United States from Comparison of Local Magnitude (ML) and Coda Duration Magnitude (MC) journal October 2020
Empirical and Synthetic Approaches to the Calibration of the Local Magnitude Scale, ML, in Southern Kansas journal March 2020
Seismic‐Hazard Forecast for 2016 Including Induced and Natural Earthquakes in the Central and Eastern United States journal August 2016
Coda journal March 2003
Spectral Inversion for Seismic Site Response in Central Oklahoma: Low-Frequency Resonances from the Great Unconformity journal November 2020
Regression problems for magnitudes journal June 2006
A Statistical Significance Test of the Difference in b-value between Two Earthquake Groups journal January 1966
Stable and Transportable Regional Magnitudes Based on Coda-Derived Moment-Rate Spectra journal February 2003
Influence of Lithostatic Stress on Earthquake Stress Drops in North America journal February 2017
Modelling correlation between Gutenberg–Richter parameters a and b in PSHA journal November 2017
Determination of Local Magnitude Distance Corrections for Northern Oklahoma journal August 2018
A Long-Term Earthquake Rate Model for the Central and Eastern United States from Smoothed Seismicity journal November 2015
Earthquake Catalogs for the USGS National Seismic Hazard Maps journal October 2018
On the Relationship between M w and M L for Small Earthquakes journal September 2016
On the stress dependence of the earthquake b value journal March 2015
Coda-Derived Source Parameters of Earthquakes and Their Scaling Relationships in the Korean Peninsula journal September 2011
Probabilistic Seismic Hazard Assessment Using Legacy Data in Georgia journal April 2020
Variations in earthquake-size distribution across different stress regimes journal September 2005
The Oklahoma Geological Survey Statewide Seismic Network journal November 2019
Assessing the Quality of Earthquake Catalogues: Estimating the Magnitude of Completeness and Its Uncertainty journal April 2005

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