GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 2.1 313 An analysis was performed of the correlation in which time of earthquakes was radomised while positions equal to those of true earthquakes. From this analysis emerged a new significant peak that suggested a further verify of the analysis. Verify indicated an error concerning the geomagnetic index which was corrected. The analysis after the correction confirmed the 2 - 3 hours correlation result and canceled the 15 - 18 hours correlation reported in the past (Fidani, 2016), see Fig. 3 left for 1800 km earthquake projection. Moreover, a correlation calculus with randomised earthquake time was repeated taking into account the correction, which confirmed absence of any correlations, see Fig. 3 right for 1800 km earthquake projection. Regarding the 2-3 hours correlation peak, if a causal connection between earthquakes and electron bursts exists, a question arises: could the 2-3 hours correlation be used for strong Indonesian earthquake forecasting? Following the method developed above to select electron bursts through adiabatic coordinates, it is currently possible to study electron bursts in real time, by defining the statistical behaviour of counting rates over the 24 hours period preceding the considered time. Starting from here an experiment of Indonesian earthquake forecasting would consist of the following phases: 1) the downloading of data immediately after each semi-orbit through the detection area; 2) counting rates analysis to find electron bursts; 3) carry out the probability calculation of a strong earthquake over the next 2 - 3 hours in Indonesia or the Philippines. To carry out phase 1) several ground stations would be necessary to be able to download data from NOAA satellites at the dovetail region (Fidani, 2015) corresponding to longitudes between 200° and 280°. This requirement could be satisfied by the presence of several Northern US ground stations. As they are localised in northern US, downloads of NOAA POES data can occur at the end of up satellite orbits or at the beginning of the next orbit for down orbits. To carry out phase 2), after uploading data in a server, it would be necessary to run automatically the software which realises the steps described above to select electron bursts. Phase 3) must take into account the results of the statistical correlation of 2 - 3 hours. This can be made through the relation between covariance and correlation (Billingsley, 1995) applied to earthquake and electron burst events: (1) with cov(EQ,EB) = [P(EQ ∩ EB)−P(EQ)P(EB)], and where P(EQ) and P(EB) are the independent probabilities of earthquake and electron burst occurrence, respectively. Then the joint probability is (2) and the conditional probability P(EQ|EB) = P(EQ ∩ EB)/P(EB) is Fig. 3 - The correlation between earthquakes and electron bursts calculated over 144 hours, without (on the left) and with (on the right) randomised earthquake times; no significant peaks are above the threshold of 99%, in yellow, in this latter case. The average is represented by the red line.