Earthquake forecasting based on ionosphere statistical monitoring
- 1. Earthquake Forecasting based on Ionosphere Statistical Monitoring: A BRIEF OF THE INTEGRATED METHOD FOR IONOSPHERIC-SEISMIC MONITORING CHILE-SISMOS 2012
- 2. Earthquake Forecasting based on Ionosphere Statistical Monitoring 1. DATA COLLECTING AND PROCESSING The GPS data is obtained from the IGS stations and others, at the UNAVCO server site. Daily files are extracted in RINEX format. They content geodetic measures and an estimation of the ionospheric signal delay (∆t).
- 3. Earthquake Forecasting based on Ionosphere Statistical Monitoring 1. DATA COLLECTING AND PROCESSING RINEX files are processed by Rinex GPS-TEC software, provided by Gopi Seemala Ph.D ( Gopi.Seemala@BC.edu) . STD extension ASCII output files contain the VTEC values measured every 10 minutes. UT VTEC σTEC Lat 0.00 17.03 4.11 -34.38 0.10 16.89 3.99 -34.38 0.20 16.83 3.47 -34.38 0.30 17.08 3.33 -34.38 0.40 17.29 3.21 -34.38
- 4. Earthquake Forecasting based on Ionosphere Statistical Monitoring 2. STATISTICAL CALCULATION A Summation Index analysis of the VTEC from 2 GPS- TEC stations is performed (Pulinet et al. 2004) C = Σ (f 1,i – af1) (f 2,i -af 2) k(σ1σ2) An upper percentage deviation of the analysis for each GPS-TEC station values is also performed UB = (x - UB) or UB = x 0.96 σ UB The daily or 3-hours kp index is arranged in a chart
- 5. Earthquake Forecasting based on Ionosphere Statistical Monitoring 3. INTERPRETATION OF RESULTS A triangulation based on the Index Summation chart is estimated for 3 stations: C(1, 2), C(2, 3), and C(3,1). Every value >0.8 is compared against the peaks from the upper percentage deviation and kp index trends. GPS-TEC Source Earthquake Anomaly (C>0.8) will be present in the closer GPS-TEC station
- 6. Earthquake Forecasting based on Ionosphere Statistical Monitoring 3. INTERPRETATION OF RESULTS In days under kp<4, drops on the C charts (>0.8) might be interpreted as ionospheric anomalies produced by electro-chemical, or electromagnetic emissions from the crustal region close to the faults prior an earthquake, or a vulcano eruption. Generally, there is an opposite behavior between the C and UB% charts in the time that anomalies occur. A peak in the 1020Ǻ Aerosol Optical Thickness (AOT), is also observed in most of the cases. This is the wavelength of the Radon (Rn).
- 7. Earthquake Forecasting based on Ionosphere Statistical Monitoring 3. INTERPRETATION OF RESULTS K=4 UTC: 08:33:05 04/07/2012 5.2Mw Concepción (8 days ahead)
- 8. Earthquake Forecasting based on Ionosphere Statistical Monitoring 3. INTERPRETATION OF RESULTS A “zoom” of the anomaly in the %UB chart provide a dimensional analysis of the TEC disturbance: Per Dovobrolsky’s equation magnitude can be estimated Max: 28,26 40 1130.4 565.2 6.4 Min: 7,05 40 282 141 5.0 Aver: 17,65 40 706 353 5.9 UTC: 08:33:05 04/07/2012 5.2Mw Concepción (8 days ahead)
- 9. Earthquake Forecasting based on Ionosphere Statistical Monitoring 3. INTERPRETATION OF RESULTS LATEST RESULTS: Date Anomaly Magnitude Estimated Date Date EQ Magnitude Days Ahead Efficiency % 5/19/2012 5.5 5/26/2012 5/28/2012 6.6 10 83.33 5/24/2012 5.6 6/1/2012 5/31/2012 4.6 7 82.14 5/29/2012 5.3 6/5/2012 6/6/2012 4.1 8 77.36 6/4/2012 5.9 6/12/2012 6/7/2012 5.8 3 98.31 6/15/2012 5.5 6/23/2012 6/23/2012 4.5 8 81.82 6/23/2012 5.9 7/1/2012 6/28/2012 5.2 5 88.14 6/25/2012 5.2 7/3/2012 7/4/2012 4.8 9 92.31 Ahead Average Days: 7 Efficiency: 86.2%