Reply to “Comment on ‘Two Foreshock Sequences Post Gulia and Wiemer (2019)’ by Kelian Dascher-Cousineau, Thorne Lay, and Emily E. Brodsky” by Laura Gulia and Stefan Wiemer

2021 ◽  
Author(s):  
Kelian Dascher-Cousineau ◽  
Thorne Lay ◽  
Emily E. Brodsky
Keyword(s):  
Puerto Rico ◽  
Real Time ◽  
Monitoring System ◽  
Expert Judgment ◽  
Aftershock Sequence ◽  
Real Time Monitoring ◽  
Traffic Light ◽  
Light System ◽  
System Output ◽  
Earthquake Sequences

Abstract Gulia and Wiemer (2019; hereafter, GW2019) proposed a near-real-time monitoring system to discriminate between foreshocks and aftershocks. Our analysis (Dascher-Cousineau et al., 2020; hereinater, DC2020) tested the sensitivity of the proposed Foreshock Traffic-Light System output to parameter choices left to expert judgment for the 2019 Ridgecrest Mw 7.1 and 2020 Puerto Rico Mw 6.4 earthquake sequences. In the accompanying comment, Gulia and Wiemer (2021) suggest that at least six different methodological deviations lead to different pseudoprospective warning levels, particularly for the Ridgecrest aftershock sequence which they had separately evaluated. Here, we show that for four of the six claimed deviations, we conformed to the criteria outlined in GW2019. Two true deviations from the defined procedure are clarified and justified here. We conclude as we did originally, by emphasizing the influence of expert judgment on the outcome in the analysis.

Comment on “Two Foreshock Sequences Post Gulia and Wiemer (2019)” by Kelian Dascher-Cousineau, Thorne Lay, and Emily E. Brodsky

2021 ◽  
Author(s):  
Laura Gulia ◽  
Stefan Wiemer
Keyword(s):  
Puerto Rico ◽  
Magnitude Scale ◽  
Traffic Light ◽  
B Values ◽  
Light System ◽  
Meaningful Analysis ◽  
Earthquake Sequences

Abstract Dascher-Cousineau et al. (2020) apply the so-called foreshock traffic-light system (FTLS) model proposed by Gulia and Wiemer (2019) to two earthquake sequences that occurred after the submission of the model: the 2019 Ridgecrest (Mw 7.1) and the 2020 Mw 6.4 Puerto Rico earthquakes. We show in this comment that the method applied by Kelian Dascher-Cousineau et al. (2020) deviates in at least six substantial and not well-documented aspects from the original FTLS method. As a consequence, they used for example in the Ridgecrest case only 1% of the data available to estimate b-values and from a small subvolume of the relevant mainshock fault. In the Puerto Rico case, we document here substantial issues with the homogeneity of the magnitude scale that in our assessment make a meaningful analysis of b-values impossible. We conclude that the evaluation by Dascher-Cousineau et al. (2020) is misrepresentative and a not a fair test of the FTLS hypothesis.

Two Foreshock Sequences Post Gulia and Wiemer (2019)

2020 ◽  
Vol 91 (5) ◽  
pp. 2843-2850 ◽  
Author(s):  
Kelian Dascher-Cousineau ◽  
Thorne Lay ◽  
Emily E. Brodsky
Keyword(s):  
Puerto Rico ◽  
Real Time ◽  
Exact Result ◽  
Monte Carlo Sampling ◽  
B Value ◽  
Aftershock Sequence ◽  
Traffic Light ◽  
B Values ◽  
Aftershock Sequences ◽  
Abrupt Changes

Abstract Recognizing earthquakes as foreshocks in real time would provide a valuable forecasting capability. In a recent study, Gulia and Wiemer (2019) proposed a traffic-light system that relies on abrupt changes in b-values relative to background values. The approach utilizes high-resolution earthquake catalogs to monitor localized regions around the largest events and distinguish foreshock sequences (reduced b-values) from aftershock sequences (increased b-values). The recent well-recorded earthquake foreshock sequences in Ridgecrest, California, and Maria Antonia, Puerto Rico, provide an opportunity to test the procedure. For Ridgecrest, our b-value time series indicates an elevated risk of a larger impending earthquake during the Mw 6.4 foreshock sequence and provides an ambiguous identification of the onset of the Mw 7.1 aftershock sequence. However, the exact result depends strongly on expert judgment. Monte Carlo sampling across a range of reasonable decisions most often results in ambiguous warning levels. In the case of the Puerto Rico sequence, we record significant drops in b-value prior to and following the largest event (Mw 6.4) in the sequence. The b-value has still not returned to background levels (12 February 2020). The Ridgecrest sequence roughly conforms to expectations; the Puerto Rico sequence will only do so if a larger event occurs in the future with an ensuing b-value increase. Any real-time implementation of this approach will require dense instrumentation, consistent (versioned) low completeness catalogs, well-calibrated maps of regionalized background b-values, systematic real-time catalog production, and robust decision making about the event source volumes to analyze.

INVESTIGATION OF HAND KINEMATICS TOWARDS FRONT CRAWL SWIMMING USING NON-INVASIVE REAL-TIME MONITORING SYSTEM

2014 ◽  
Author(s):  
Rozaimi Ghazali ◽  
◽  
Asiah Mohd Pilus ◽  
Wan Mohd Bukhari Wan Daud ◽  
Mohd Juzaila Abd Latif ◽  
...  
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Real Time Monitoring ◽  
Front Crawl ◽  
Non Invasive ◽  
Hand Kinematics

Study on Slope Slide Real-Time Monitoring System in Guangdong Using GPS/CORS Integration Technique

2011 ◽  
Vol 13 (4) ◽  
pp. 562-570 ◽  
Author(s):  
Pingxin WEI ◽  
Chenggang LI ◽  
Feng XU ◽  
Xiaochun SHI
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Integration Technique ◽  
Real Time Monitoring

Selection and Evaluation of a Real Time Monitoring System for the Bigeye Bomb Fill/Close Production Facility. Phase 2

1989 ◽  
Author(s):  
Foy E. Ferguson ◽  
Michael W. Ellzy ◽  
Joseph W. Lovrich ◽  
Theodore L. Strozyk ◽  
Jr
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Phase 2 ◽  
Production Facility ◽  
Real Time Monitoring
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