6 Şubat 2023 Pazarcık ve Elbistan Deprem Çiftinin Sismotektonik Karakteri

<p class="AnahtarKelime"><span lang="EN-GB" style="font-size: 10pt;">On February 6, 2023, twostrong (Mw=7.7 and Mw=7.6) and shallow (h=8.9 km and h=7.7 km) earthquakes withan interval of ~9 hours were struck in the Pazarcık and Elbistan(Kahramanmaraş) provinces in southern Türkiye, respectively. </span><span lang="EN-GB" style="font-size: 10pt;">The first mainshockoccurred at 01:17:32 (UTC) and the second mainshock occurred at 10:24:47 (UTC).The focal mechanism solutions of these doublet earthquakes demonstrated theleft lateral strike-slip fault mechanisms with 310 km and 150 km surfaceruptures, respectively. According to the earthquake catalogue of the Disasterand Emergency Management Authority (AFAD), approximately 230 aftershocks wererecorded between the time interval of two mainshocks, 13 of which were magnitudegreater than M≥5.0. It is important to note that 11 aftershocks with amagnitude greater than M≥5.7 have occurred and the region has experiencedapproximately 70,000 aftershocks from 6 February 2023 to today. In general, thefocal mechanisms of these heavy aftershocks demonstrated the left-lateralstrike-slip mechanisms response to the East Anatolian Fault Zone (EAFZ) andDead Sea Fault Zone (DSFZ). </span><span lang="EN-GB" style="font-size: 10pt;">Thesegreat mainshock doublets with mass aftershocks affected 11 cities called Hatay, Kahramanmaraş, Adıyaman, Malatya, Osmaniye,Gaziantep, Kilis, Şanlıurfa, Diyarbakır, Adana and Elazığ provinces. Therefore,approximately 240,000 buildings were damaged, ~60,000people died, and ~115,000 people were injured in these cities.<o:p></o:p></span> <p class="AnahtarKelime"><span lang="EN-GB" style="font-size: 10pt;">This study conducted theseismotectonic characterization of the 6 February 2023 Pazarcık and Elbistan mainshocksand their aftershock propagations using the Coulomb stress change, potentialfield anomaly, </span><span lang="EN-GB" style="font-size:10.0pt;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin;mso-ansi-language:EN-GB;mso-bidi-font-style:italic">b</span><span lang="EN-GB" style="font-size: 10pt;">-value distribution, and aftershock clusters. Also, wemade a seismotectonic review using the horizontal displacements of the focalmechanism solutions of the main shocks and their large aftershocks. Theaftershock clustering can be observed along the EAFZ, especially related to thePütürge, Erkenek, and Pazarcık segments and the Doğanşehir fault zone in the northand northeast directions. Besides, the south and southwest-oriented aftershockzone extends to the Yumurtalık and Amanos segments with the Ecemiş fault. Onone hand, the present-day Coulomb stress variations support these directions,especially in shallow depths. In the tectonic stress field maps, <span style="color:#231F20">the mainshocks have caused the positive stress transferbetween Elazığ and Malatya provinces in the northeast, Kahramanmaraş-Göksun provincein the west, and Hatay province in the sout</span>h.</span><span lang="EN-GB" style="font-size:10.0pt;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin;mso-ansi-language:EN-GB"> </span><span lang="EN-GB" style="font-size: 10pt;">On the other hand, shallowaftershocks are associated with high-gravity anomalies. According to theanalysis of </span><span lang="EN-GB" style="font-size:10.0pt;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin;mso-ansi-language:EN-GB;mso-bidi-font-style:italic">b</span><span lang="EN-GB" style="font-size: 10pt;">-value distribution, the low </span><span lang="EN-GB" style="font-size:10.0pt;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin;mso-ansi-language:EN-GB;mso-bidi-font-style:italic">b</span><span lang="EN-GB" style="font-size: 10pt;">-values are identified in the northeast and southwest sections of EAFZ.</span><span lang="EN-GB" style="font-size: 10pt; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">Finally, wecan deduce that the observed parameters indicate upcoming seismicity in theintermediate and long term in both the northeast and southwest directions ofthe EAFZ</span><span lang="EN-GB" style="font-family: &quot;Times New Roman&quot;, serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">.<o:p></o:p></span>