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
Earthquakes are predominantly associated with tectonically active regions,yet the rising frequency of seismic events globally has raised concerns about the role of industrial activities,such as fluid injection,convent...Earthquakes are predominantly associated with tectonically active regions,yet the rising frequency of seismic events globally has raised concerns about the role of industrial activities,such as fluid injection,conventional oil-gas,mining,and reservoir impoundment,in triggering significant earthquakes.While natural processes like tectonic stress changes,fluid migration,and surface loading are critical in earthquake nucleation,human-induced seismicity is becoming increasingly recognized.The Atatürk Dam,Türkiye's largest clay-core rockfill dam,situated near the East Anatolian Fault System,Adyaman Fault Zone,and Bozova Fault,offers a compelling case to explore the interplay between tectonic and anthropogenic seismicity.This study presents the first trenching studies along the Bozova Fault,revealing evidence of surface ruptures and localized seismicity linked to reservoir impoundment and conventional oil and gas.Temporal and spatial analyses suggest that reservoir-induced mechanisms,including pore pressure diffusion and stress redistribution,significantly influence seismicity,recurrence interval,alongside dominant tectonic forces.By integrating trenching investigations,seismic analyses,and stress inversion techniques,this research highlights the critical role of anthropogenic factors in modulating seismic hazards.The findings emphasize the importance of paleoseismological and geophysical studies for distinguishing induced seismicity from natural tectonic activity,thereby contributing to improved seismic hazard assessment and mitigation strategies in tectonically active,reservoir-influenced regions.展开更多
Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel...Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel insights into physical criteria for delineating surface fault-rupture hazard zones(SRHZs)along ruptured strike-slip faults.To achieve this objective,three trench studies across the surface rupture were conducted on the Pazarcık segment of the EAFZ to collect field data,and earthquake recurrence intervals were interpreted using Bayesian statistics from previously conducted paleoseismological trenchings.The results of the proposed model indicate that the Pazarcık segment produced five significant surface-rupturing earthquakes in the last∼11 kyr:E1:11.13±1.74 kyr,E2:7.62±1.20 kyr,E3:5.34±1.05 kyr,E4:1.82±0.93 kyr,and E5:0.35±0.11 kyr.In addition,the recurrence intervals of destructive earthquakes on the subject in question range from 0.6 kyr to 4.8 kyr.Considering that the last significant earthquake occurred in 1513,the longest time since the most recent surface fault rupturing earthquake on this particular segment was 511 years.These results indicate that,in terms of the theoretical recurrence interval of earthquakes that can create surface ruptures on the Pazarcık segment,the period in which the February 6,2023,earthquake occurred was within the end of the expected return period.As a result,the potential for a devastating earthquake in the near future is not foreseen on the same fault.Finally,the SRHZ proposed for the Pazarcık section of Gölbaşıvillage was calculated as a 61-meter-wide offset on the fault lineament to reduce the negativities that may occur in the ruptured area in the future.It is recommended to take into account this width in the settlement of this area and nearby areas.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Earthquakes are predominantly associated with tectonically active regions,yet the rising frequency of seismic events globally has raised concerns about the role of industrial activities,such as fluid injection,conventional oil-gas,mining,and reservoir impoundment,in triggering significant earthquakes.While natural processes like tectonic stress changes,fluid migration,and surface loading are critical in earthquake nucleation,human-induced seismicity is becoming increasingly recognized.The Atatürk Dam,Türkiye's largest clay-core rockfill dam,situated near the East Anatolian Fault System,Adyaman Fault Zone,and Bozova Fault,offers a compelling case to explore the interplay between tectonic and anthropogenic seismicity.This study presents the first trenching studies along the Bozova Fault,revealing evidence of surface ruptures and localized seismicity linked to reservoir impoundment and conventional oil and gas.Temporal and spatial analyses suggest that reservoir-induced mechanisms,including pore pressure diffusion and stress redistribution,significantly influence seismicity,recurrence interval,alongside dominant tectonic forces.By integrating trenching investigations,seismic analyses,and stress inversion techniques,this research highlights the critical role of anthropogenic factors in modulating seismic hazards.The findings emphasize the importance of paleoseismological and geophysical studies for distinguishing induced seismicity from natural tectonic activity,thereby contributing to improved seismic hazard assessment and mitigation strategies in tectonically active,reservoir-influenced regions.
基金partially supported by the Turkish government through the 1002-C project in Natural Disasters Focused Fieldwork Emergency Support Program managed by the TUBITAK.I am grateful to F.Koçbulut and S.Koşaroğlu for helping me with the trenching studies.I also gratefully acknowledge H.Sözbilir,M.Nas,and E.Akgün for comments and suggestions.Furthermore,I extend my gratitude to the anonymous referees for their constructive criticisms and insightful feedback during the evaluation phase of this manuscript.
文摘Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel insights into physical criteria for delineating surface fault-rupture hazard zones(SRHZs)along ruptured strike-slip faults.To achieve this objective,three trench studies across the surface rupture were conducted on the Pazarcık segment of the EAFZ to collect field data,and earthquake recurrence intervals were interpreted using Bayesian statistics from previously conducted paleoseismological trenchings.The results of the proposed model indicate that the Pazarcık segment produced five significant surface-rupturing earthquakes in the last∼11 kyr:E1:11.13±1.74 kyr,E2:7.62±1.20 kyr,E3:5.34±1.05 kyr,E4:1.82±0.93 kyr,and E5:0.35±0.11 kyr.In addition,the recurrence intervals of destructive earthquakes on the subject in question range from 0.6 kyr to 4.8 kyr.Considering that the last significant earthquake occurred in 1513,the longest time since the most recent surface fault rupturing earthquake on this particular segment was 511 years.These results indicate that,in terms of the theoretical recurrence interval of earthquakes that can create surface ruptures on the Pazarcık segment,the period in which the February 6,2023,earthquake occurred was within the end of the expected return period.As a result,the potential for a devastating earthquake in the near future is not foreseen on the same fault.Finally,the SRHZ proposed for the Pazarcık section of Gölbaşıvillage was calculated as a 61-meter-wide offset on the fault lineament to reduce the negativities that may occur in the ruptured area in the future.It is recommended to take into account this width in the settlement of this area and nearby areas.
