The Palu segment,situated in the northeastern part of the East Anatolian Fault System(EAFS),is a crucial structural feature with notable seismic potential.This study examines the paleoseismic activity of the Palu segm...The Palu segment,situated in the northeastern part of the East Anatolian Fault System(EAFS),is a crucial structural feature with notable seismic potential.This study examines the paleoseismic activity of the Palu segment through trench excavations and geochronological analyses utilizing Optically Stimulated Luminescence(OSL)and radiocarbon(14C)dating methods.Two trenches,located near Karşıbahçeler,exposed evidence of multiple surface-rupturing seismic events spanning the Holocene and Pleistocene epochs.Chronological analyses identified five distinct seismic events in trench 1(P1),dated between 94.09±6.07 ka and 0.84±0.45 ka,and three events in trench 2(P2),dated between 28.83±1.61 ka and 351±21 BP.Bayesian analysis using Oxcal distribution suggested event timings between 90.52±25.99 ka and 1.25±0.55 ka.Comparative analysis with historical earthquake records correlates the most recent event with the 1789 or 1874 AD earthquakes,while the penultimate event matches the 995 AD earthquake.Earlier events reflect prehistoric tectonic activity.The recurrence intervals for these events range from 710 to 5,370 years during the Holocene,with evidence of seismic activity extending into the Pleistocene.Stress inversion analyses and geodetic data indicate a predominantly strike-slip stress regime,consistent with geometry of the fault.These findings provide critical insights into the long-term seismic behavior and recurrence patterns of the Palu segment,enhancing seismic hazard assessments for the region.展开更多
This paper investigates the correlation between tidal stress and earthquakes for periods ranging from hours to months in the limited zone of the Palu region(Central Sulawesi,Indonesia).Through Schuster and binomial te...This paper investigates the correlation between tidal stress and earthquakes for periods ranging from hours to months in the limited zone of the Palu region(Central Sulawesi,Indonesia).Through Schuster and binomial tests,we examined the relation between the seismicity(time density of seismic events)and tidal potential arising from the Moon and Sun,using all tidal components simultaneously and focusing on the estimation of specific terms.The results show significant correlations between the seismicity and tidal potential for S2(0.5 d)and O1(1.075 d)tidal components in the case of solely isolated earthquake events,particularly for shallow earthquakes.Meanwhile,there is a strong relationship between aftershocks and tidal components larger than the Mf period(13.661 d).Finally,the analysis of the temporal variation of the earthquake-tide relation reveals an optimal correlation for about six years before the 2018 great Palu earthquake.The correlation becomes insignificant afterwards.展开更多
The 2018 Palu M_W7.5 earthquake and tsunami attracted geophysicists' attention for its strike slip focal mechanism and magnitude. We inspected the details of this disaster and discussed its particularity and possi...The 2018 Palu M_W7.5 earthquake and tsunami attracted geophysicists' attention for its strike slip focal mechanism and magnitude. We inspected the details of this disaster and discussed its particularity and possible causations. The submarine landslide and special terrain conditions could have contributed to the unusual size of the tsunami. The early warning system and the post disaster response is also reviewed. Efficient social warnings and broadcast systems along with good maintenance is essential. We also found that enhancing publics scientific literacy is the most important way to reduce disaster damage and casualties. Moreover, social conditions and rebuilding difficulties post tsunami are related as reference resources for future disaster management strategies.展开更多
The Lake Hazar basin,located along the Palu segment of the East Anatolian Fault System(EAFS),provides a key natural laboratory for examining transtensional deformation in a major intracontinental strike-slip zone.Inte...The Lake Hazar basin,located along the Palu segment of the East Anatolian Fault System(EAFS),provides a key natural laboratory for examining transtensional deformation in a major intracontinental strike-slip zone.Integrated field mapping,fault-slip analysis,and focal mechanism inversion reveal a polyphase tectonic history involving sequential compressional,strike-slip,and extensional regimes.Rigorous discrimination of heterogeneous fault-slip datasets into homogeneous subsets enabled reconstruction of geologically consistent stress tensors and clarified the temporal transition from strike-slip to transtensional deformation.Paleostress results indicate NNE–SSW compression and NW–SE extension,consistent with present-day seismotectonic and geomorphic patterns.Variations in stress ratio Rvalues(0.26–0.57 for strike-slip;0.28–0.33 for extensional domains)and low misfit angles(<15°)reflect localized strain partitioning and reactivation of inherited faults.The Lake Hazar basin thus evolved from a pull-apart structure into a negative flower geometry through successive deformation and fault linkage.These findings highlight that discriminating polyphase fault-slip data is essential for resolving deformation dynamics in complex fault systems.The integrated structural,paleostress,and seismotectonic framework presented here refines understanding of strain localization,fault reactivation,and stress transfer along the East Anatolian Fault System.展开更多
On September 28, 2018, a Mw7.5 earthquake occurred near Sulawesi, Indonesia as a result of strike-slip faulting at shallow depth within the interior of the Molucca Sea Microplate that forms a part of the broader Sunda...On September 28, 2018, a Mw7.5 earthquake occurred near Sulawesi, Indonesia as a result of strike-slip faulting at shallow depth within the interior of the Molucca Sea Microplate that forms a part of the broader Sunda Plate. Focal mechanism solutions and distribution for the earthquakes indicate rupture occurred on a left-lateral NNW-SSE-to N-S-striking fault. This region has been characterized by complex tectonics in which motions of numerous small microplates are accommodating large-scale convergence between the Australia, Sunda, Pacific and Philippine Sea plates. In this paper, the Coulomb stress calculation verified the WNW-, nearly E-W-trending sinistral strike slip receiver fault in Sulawesi, which is consistent with the giant sinisterly strike-slip fault system across New Guinea, Pacific Tectonic System and the Tethys Tectonic System caused by the oblique convergence. The result has been reconciled within the modern GPS velocity field.展开更多
基金partially supported by the Fırat University Scientific Research Project in Elazığ,Türkiye,under Project Number ADEP.23.12.
文摘The Palu segment,situated in the northeastern part of the East Anatolian Fault System(EAFS),is a crucial structural feature with notable seismic potential.This study examines the paleoseismic activity of the Palu segment through trench excavations and geochronological analyses utilizing Optically Stimulated Luminescence(OSL)and radiocarbon(14C)dating methods.Two trenches,located near Karşıbahçeler,exposed evidence of multiple surface-rupturing seismic events spanning the Holocene and Pleistocene epochs.Chronological analyses identified five distinct seismic events in trench 1(P1),dated between 94.09±6.07 ka and 0.84±0.45 ka,and three events in trench 2(P2),dated between 28.83±1.61 ka and 351±21 BP.Bayesian analysis using Oxcal distribution suggested event timings between 90.52±25.99 ka and 1.25±0.55 ka.Comparative analysis with historical earthquake records correlates the most recent event with the 1789 or 1874 AD earthquakes,while the penultimate event matches the 995 AD earthquake.Earlier events reflect prehistoric tectonic activity.The recurrence intervals for these events range from 710 to 5,370 years during the Holocene,with evidence of seismic activity extending into the Pleistocene.Stress inversion analyses and geodetic data indicate a predominantly strike-slip stress regime,consistent with geometry of the fault.These findings provide critical insights into the long-term seismic behavior and recurrence patterns of the Palu segment,enhancing seismic hazard assessments for the region.
文摘This paper investigates the correlation between tidal stress and earthquakes for periods ranging from hours to months in the limited zone of the Palu region(Central Sulawesi,Indonesia).Through Schuster and binomial tests,we examined the relation between the seismicity(time density of seismic events)and tidal potential arising from the Moon and Sun,using all tidal components simultaneously and focusing on the estimation of specific terms.The results show significant correlations between the seismicity and tidal potential for S2(0.5 d)and O1(1.075 d)tidal components in the case of solely isolated earthquake events,particularly for shallow earthquakes.Meanwhile,there is a strong relationship between aftershocks and tidal components larger than the Mf period(13.661 d).Finally,the analysis of the temporal variation of the earthquake-tide relation reveals an optimal correlation for about six years before the 2018 great Palu earthquake.The correlation becomes insignificant afterwards.
基金sponsored by the Scientific Research Institutes' Basic Research and Development Operations Special Fund of the Institute of Geophysics,China Earthquake Administration(Grant No.DQJB18B08)the National Natural Science Foundation of China(Grant No.41674058 and 41804063)
文摘The 2018 Palu M_W7.5 earthquake and tsunami attracted geophysicists' attention for its strike slip focal mechanism and magnitude. We inspected the details of this disaster and discussed its particularity and possible causations. The submarine landslide and special terrain conditions could have contributed to the unusual size of the tsunami. The early warning system and the post disaster response is also reviewed. Efficient social warnings and broadcast systems along with good maintenance is essential. We also found that enhancing publics scientific literacy is the most important way to reduce disaster damage and casualties. Moreover, social conditions and rebuilding difficulties post tsunami are related as reference resources for future disaster management strategies.
文摘The Lake Hazar basin,located along the Palu segment of the East Anatolian Fault System(EAFS),provides a key natural laboratory for examining transtensional deformation in a major intracontinental strike-slip zone.Integrated field mapping,fault-slip analysis,and focal mechanism inversion reveal a polyphase tectonic history involving sequential compressional,strike-slip,and extensional regimes.Rigorous discrimination of heterogeneous fault-slip datasets into homogeneous subsets enabled reconstruction of geologically consistent stress tensors and clarified the temporal transition from strike-slip to transtensional deformation.Paleostress results indicate NNE–SSW compression and NW–SE extension,consistent with present-day seismotectonic and geomorphic patterns.Variations in stress ratio Rvalues(0.26–0.57 for strike-slip;0.28–0.33 for extensional domains)and low misfit angles(<15°)reflect localized strain partitioning and reactivation of inherited faults.The Lake Hazar basin thus evolved from a pull-apart structure into a negative flower geometry through successive deformation and fault linkage.These findings highlight that discriminating polyphase fault-slip data is essential for resolving deformation dynamics in complex fault systems.The integrated structural,paleostress,and seismotectonic framework presented here refines understanding of strain localization,fault reactivation,and stress transfer along the East Anatolian Fault System.
基金National Programme on Global Change and Air-Sea Interaction, State Oceanic Administration (GASI-GEOGE-01)National Key Research and Development Program of China (2017YFC0601401 and 2016YFC0601002)+1 种基金supported by Aoshan Talents Program Supported by Qingdao National Laboratory for Marine Science and Technology to Prof. Sanzhong Li (2015ASTP-0S10)the Taishan Scholar Program to Prof. Sanzhong Li
文摘On September 28, 2018, a Mw7.5 earthquake occurred near Sulawesi, Indonesia as a result of strike-slip faulting at shallow depth within the interior of the Molucca Sea Microplate that forms a part of the broader Sunda Plate. Focal mechanism solutions and distribution for the earthquakes indicate rupture occurred on a left-lateral NNW-SSE-to N-S-striking fault. This region has been characterized by complex tectonics in which motions of numerous small microplates are accommodating large-scale convergence between the Australia, Sunda, Pacific and Philippine Sea plates. In this paper, the Coulomb stress calculation verified the WNW-, nearly E-W-trending sinistral strike slip receiver fault in Sulawesi, which is consistent with the giant sinisterly strike-slip fault system across New Guinea, Pacific Tectonic System and the Tethys Tectonic System caused by the oblique convergence. The result has been reconciled within the modern GPS velocity field.
