Estimating the Epicenter of a Future Strong Earthquake in Southern California, Mexico, and Central America by Means of Natural Time Analysis and Earthquake Nowcasting

Abstract

It has recently been shown in the Eastern Mediterranean that by combining natural time analysis of seismicity with earthquake networks based on similar activity patterns and earthquake nowcasting, an estimate of the epicenter location of a future strong earthquake can be obtained. This is based on the construction of average earthquake potential score maps. Here, we propose a method of obtaining such estimates for a highly seismically active area that includes Southern California, Mexico and part of Central America, i.e., the area N1035W80120. The study includes 28 strong earthquakes of magnitude M ≥7.0 that occurred during the time period from 1989 to 2020. The results indicate that there is a strong correlation between the epicenter of a future strong earthquake and the average earthquake potential score maps. Moreover, the method is also applied to the very recent 7 September 2021 Guerrero, Mexico, M7 earthquake as well as to the 22 September 2021 Jiquilillo, Nicaragua, M6.5 earthquake with successful results. We also show that in 28 out of the 29 strong M ≥7.0 EQs studied, their epicenters lie close to an estimated zone covering only 8.5% of the total area.

Natural Time Analysis of Global Seismicity

“…73.99 0.862 (8) using the Weibull distribution provides a fair approximation with root mean square of residuals [117] equal to 0.017. This is in accordance with the results found in References [79,81,110].…”

“…We note that SES are low-frequency variations of the electric field of the Earth that precede EQs, see, e.g., References [4,[66][67][68][69][70][71][72][73][74][75]. Moreover, characteristic (local) minima of β W have been identified in California [76], Japan [11], Mexico [77][78][79], Eastern Mediterranean [80,81], and Global seismicity [13,82] before the strongest EQs, i.e., those in the EQ catalog having a magnitude M greater than or equal to a target threshold M t , M ≥ M t , and these minima are statistically significant precursors [83,84]. Interestingly, the appearance of these minima has been related [85] to the emission of SES activities and are also simultaneous with changes in the long-range correlations of the EQ magnitude time series [64,86,87] (cf.…”

“…Thus, the number n stands for the waiting natural time or interoccurrence natural time. The EQ catalogs used [42,43,79,81,[108][109][110][111][112] for earthquake nowcasting are publicly available global EQ catalogs. Here, we used the GCMT EQ catalog, see Section 2.1.…”

“…an extensive related review has been published by Varotsos et al [88]). Finally, almost a year ago, the combination of the study of the fluctuations β W of the order parameter κ 1 of seismicity provided an earthquake nowcasting method of estimating the epicenter of a forthcoming strong EQ, which was based on the self-consistent construction of average EPS maps [79,81].…”

Analysis of Potential Precursory Pattern at Earth Surface and the Above Atmosphere and Ionosphere Preceding Two Mw ≥ 7 Earthquakes in Mexico in 2020–2021

“…The Cocos plate and Rivera Plate move northeastward, the Caribbean plate moves eastward, the North American plate moves southwestward, and the Eastern Pacific plate moves northwestward. Cocos plate subducts beneath the North American plate, and the subduction interface indicates a significant variety in strike dip angles along the central portion of the Middle American Trench (Perez‐Oregon et al., 2021). Such interaction around the Mexican Pacific's southern coast is the main inducement of earthquakes in the country.…”