Application of apparent strong earthquake activity pattern in operational earthquake forecasting

Abstract

Consulting the Catalogue of the International Seismological Centre (ISC), for the period 1904–2016 to detect the occurrence of potentially damaging earthquakes we observed that in most cases, when a high magnitude earthquake occurs (magnitude of at least 6.5), there is an increased probability that a similar high magnitude earthquake will occur within a relatively short period of weeks (less than a year). This occurs when the two events are located on latitudes of practically the same absolute value. This Apparent Strong Earthquake Pattern (ASEP) is observed in about 90% of all earthquakes of magnitudes greater than, or equal to 6.5. ASEP is evident in a high percentage of events and remains practically unchanged even after shuffling the dates of occurrence of earthquakes several times. This statistical observation is not surprising when considering the geographic distribution of earthquake epicenters and activity rates in regions of relatively frequent high magnitude earthquakes. Nevertheless, it leads us to consider the possibility of introducing ASEP in earthquake risk management and Operational Earthquake Forecasting (OEF). The main objective of this study is to assess the potential of estimating the location, magnitude, and time of occurrence of a strong earthquake after the occurrence of a similar strong earthquake in a distant area, when subsequent events conform to the apparent event pattern of strong earthquakes. The effectiveness of ASEP is quantified in terms of the ratio between the success rates obtained by applying ASEP and the probability of a randomly occurring earthquake of magnitude M in a given seismic zone within dT weeks. The effectiveness of ASEP was initially evaluated through simulations from the data from earthquake catalogues. The simulations reveal, as expected, that when the earthquakes in catalogue A are independent of the earthquakes in catalogue B, and when the occurrence of earthquakes in each catalogue are random and obey laws of Poisson distribution, the effectiveness is always lower than 1, i.e., the chance of a successful random guess is always higher than the probability of successful forecasting that follows ASEP. The opposite is observed when applying the ASEP schema to real cases. After arbitrarily choosing ten pairs of seismogenic zones, the success rates of the apparent earthquake pattern forecasts always yield a higher forecast probability, sometimes considerably higher than would a random guess. It is also observed that when selecting pairs of active zones which fail to obey ASEP requirement about the locations of events, the success rate of forecasting is, in most tested cases, zero. i.e., similar to what is observed in the simulations. Subsequently, the proposed forecasting scheme based on ASEP may be useful for OEF applications which in turn could be considered in earthquake risk management programs. These observations also suggest that the temporal behavior of strong earthquakes is not purely random.

Ukrayna İşgali Döneminde Jeopolitik Risk ve Ekonomik Belirsizliğin Yeşil Tahvil Piyasası Üzerindeki Nedensellik Etkileri

“…Başçı ve Başçı (2022), BİST'te bulunan on iki şehir endeksinin belirleyicilerini araştırmışlardır. Panel veri analizi yöntemini kullanmışlardır.…”

“…Numerous papers (e.g., Lee et al, 2021;Lee et al, 2022;Long et al, 2022;Piñeiro-Chousa et al, 2021;Tian et al, 2022) study the impact of financial or uncertainty/risk factors on the green bond market by applying various techniques other than causality tests. For example, Long et al (2022) examine the relationship between uncertainty and green bonds in the U.S., Europe, and China using a quantitative connectedness approach based on VAR and find that stock market uncertainty (VIX) and oil market uncertainty (OVX) exhibit a larger influence on green bonds, particularly in emerging markets. Tian et al (2022) use a nonlinear ARDL model to examine how climate policy uncertainty (CPU), infectious disease stock market volatility (IDEMV), the CBOE Crude Oil Volatility Index (OVX), and geopolitical risk (GPR) affect green bond prices in the United States, Europe, and China.…”

“…Buna karşılık Alhares (2020) ve Almor vd. (2022) araştırmalarında kadın üye oranı ve ar-ge faaliyetleri arasında negatif bir ilişkinin bulunduğu sonucunu elde etmişlerdir.…”

“…Kaya (2021) MKK tarafından açıklanan yerli, yabancı yerli gerçek ve yerli tüzel yatırımcı risk iştahı endeksleri arasındaki ilişkiyi 4 Ocak 2008 ile 7 Ağustos 2020 dönemi için incelemiştir. Seriler arasında uzun dönemli ilişkinin varlığını tespit ettikten sonra nedensellik analizi yapmış her bir risk iştahı endeksinin karşılıklı nedensellik ilişkisine sahip olduğu sonucuna ulaşmıştır.Yılmaz ve Yıldız(2022) yatırımcı risk iştahı endeksleri ile VIX Korku Endeksleri arasındaki ilişkiyi incelemek için Ocak 2008 ile Nisan 2022 tarihleri arasını ele almışlardır. Korku endeksleri arasında V2TX(Avrupa) korku endeksinin tüm yatırımcı tiplerinin risk iştahı üzerinde en etkili korku endeksi olduğu sonucuna ulamışlardır.…”

“…Nitekim kadın üye oranı ar-ge harcamaları arasındaki negatif ilişki, kurul üye sayısı ve ar-ge harcamaları arasındaki ilişkiye benzer şekilde negatiftir. Elde edilen bulgular Alhares (2020) ve Almor vd (2022). gibi araştırmacıların sonuçları ile örtüşmektedir.…”