West Pacific Earthquake Forecasting Using NOAA Electron Bursts With Independent L-Shells and Ground-Based Magnetic Correlations

Abstract

Recent advances in statistical correlations between strong earthquakes and several non-seismic phenomena have opened the possibility of formulating warnings within days or even hours. The retrieved correlations have been discovered for those ionospheric physical observations which lasted a long time and realized using the same instruments, including multi-satellite recordings. One of those regarded the electron burst phenomena detected by NOAA, for which the conditional probability of a seismic event was calculated. Then an earthquake probability greater than its frequency was assigned when a satellite realized such a phenomenological observation. This approach refers to the correlations obtained between high-energy electrons detected using the NOAA POES and strong Indonesian and Philippine earthquakes. It is reformulated here to realize a test of earthquake forecasting. The fundamental step is obtained by using a unique electron L-shell interval of 1.21 ≤ L ≤ 1.31, which decouples the electron parameters from the earthquake parameters. Then, the optimized correlation was recalculated to be 1.5–3.5 h early, between electron bursts and an increased number of seismic events with M ≥ 6, therein improving the significance too. Moreover, this methodology is reconnected to the frequency theory, and to Molchan’s error diagram, by the probability gain, where a comparison among the significances of various methods is given. The previously proposed physical link between the crust and the ionosphere through magnetic interaction, presumably operating 4–6 h before strong earthquakes, is examined quantitatively on the basis of recent magnetic pulse measurements. Consequently, the probability gain of earthquake forecasting is hypothetically calculated for both the dependent measurements of electron bursts using NOAA satellites and possible ground-based magnetic pulse detection. This method of combining probability gains for earthquake forecasting is general enough that it can be applied to any pair of observables from space and the ground.

Transfer Entropy of West Pacific Earthquakes to Inner Van Allen Belt Electron Bursts

“…These can be evaluated immediately because the unconditioned probabilities are known for the singularly considered systems of West Pacific EQs and precipitating EBs from the internal Van Allen belts [12]. The total entropy of the two systems is the sum of their entropies.…”

“…In fact, considering the probability gain from EBs and the probability gain from magnetic pulses, a combined probability gain was calculated supposing to use both together. Thus, the probability gains due to one of two types of events indifferently retrieved in the same space-time region, was shown to be greater than each EB and magnetic pulse probability gains [12].…”

“…This study was based upon the large data set of particle counting rates, EQs, and geomagnetic indexes that are deposited in publicly available databases. A well-established method [9][10][11][12] permits to define EBs from the 30-100 keV electron counting rate database during geomagnetically quiet days defined by geomagnetic indexes. Then, EBs are correlated to EQs running on 16.5 years of data by filling histograms for intervals of positive and negative delays between each other.…”

“…A correlation between EQs and EBs has been recently calculated so as to unambiguously define EBs. It was obtained by including only an EB L-shell in a restricted interval [12]. A peak of correlation appeared when considering EQs at a depth of less than 200 km, located in a large portion of the Earth's crust in the West Pacific, with a minimum magnitude of 6.…”

“…In a recent publication, results of a possible EQ forecasting experiment by NOAA satellites were estimated, as well as the number of false alarms. The complete equivalence of this formulation with those of the probability gain for a test verification was presented [12]. The hypothesis of magnetic pulses able to push electrons out of the trapped conditions was quantitatively evaluated, starting from recent results of magnetic measurements [13].…”