Investigating Generation of the February 6,2023 M7.8 Double Earthquakes in Türkiye
Generation of the double Ms7.8 earthquakes of 6 February 2023 in southern Türkiye was comprehensively studied based on the crust structure and seismogeologic,ge-ophysical and geothermal fluid geochemistry data as well as the spatial-temporal character-istics of the seismic sequence occurrences,in order to improve earthquake prediction and earthquake generation research.The double M7.8 earthquakes took place on 6 February 2023 in southern Türkiye,companying dozens of M≥5.0 earthquakes and several thou-sands of M＜5.0 aftershocks in the duration of 6-17 February.Depths of the earthquakes focus range from 5 km to 22 km.The earthquake epicenters predominantly distributed in two belts in an area of about 500 km X 300 km.One belt of NE trending has a length of 300 km and width of 40 km,another belt of EW trending has a length of 240 km and width of 50 km.Existences of low velocity and resistivity zone in the crust,high heat flow a-nomaly,negative Bouguer gravity anomaly,aeromagnetic anomaly and the deep-cut fault zones in the study area indicate that there are the necessary requirements for mantle-de-rived fluid accumulation and formation of super-pressure fluid bodies in the lithosphere of the area.The process of locally mantle-derived fluid accumulation to build super-pressure fluid bodies can be considered as the process of seismogenesis.The periodical accumulation of earthquake hypocenters in space and variations of the hypocenter depths during 6-17 February indicated that increasing supplement of high-energy-density fluids derived from the mantle to the earthquake source bodies,resulted in repeated increases of fluid pres-sure.Cryptoexplosion occurred when the fluid pressure in the source bodies exceeded the strength of the surrounding rocks(compressive strength+hydrostatic pressure),produ-cing earthquakes.The high-energy-density fluids migrated in the way of the inflate-explo-sion-deflate-inflate-explosion-deflate cycle,which produced the M7.8 double earthquakes and aftershocks.Therefore,the M7.8 double earthquakes and M≥4.0 aftershocks occur-ring in the discontinuous inelastic source bodies in the small region can be reasonably ex-plained from the view of energy source and seismogenesis of geothermal fluid explosion.
Double M7.8 earthquakesCryptoexplosionMantle-derived fluidsSeis-mopregnant process of geothermal fluidsSeismogenesisTürkiye
NETL
NSTL
万方数据
