-
摘要:
洋中脊是地球上重要的火山-地震带之一，也是多圈层相互作用以及能量和物质交换的重要构造位置。洋中脊作为板块构造理论中典型的离散板块边界，伸展构造以及与其相关的正断层活动是其变形的主旋律。然而，2022年年底北大西洋54ºN段发生了一次逆冲断层地震活动。文章主要报道并简述与这次地震事件相关的且发表在2024年4月Nature 期刊上的一篇研究论文。该论文通过地震观测、地质分析及数值模拟等多学科综合研究，详细报道了在典型离散板块边界发生的逆冲地震活动，深入分析了短时间尺度内地震事件在海底地貌上的记录，并对伸展构造背景下挤压应力区的发育机制进行了论证。以上研究挑战了离散板块边界只发育伸展构造的传统观点，也证实了多学科综合作业以及多时间尺度地质过程耦合分析等手段对开展固体地球科学研究的必要性。
Abstract:The mid-ocean ridge is a remarkable feature of our planet, renowned as one of Earth's most vital zones for volcanic and seismic activity. It serves as a crucial setting for the transfer of energy and materials between the ocean and lithosphere. As the archetypal divergent plate boundary, mid-ocean ridges are primarily sculpted by extensional tectonics and the associated development of normal faults. However, in a surprising twist, a thrust seismic event was detected in late 2022 along the 54ºN segment of the Atlantic mid-ocean ridge. This article focuses on summarizing a recent paper that addresses this seismic event, featured in the prestigious journal Nature (https://www.nature.com/articles/s41586-024-07247-w). The research, integrating seismic observations, geological analyses, and numerical simulations across multiple disciplines, provides a detailed account of the thrust seismic activity at a classical divergent plate boundary. It delves into the imprint of these short-lived seismic events on the landscape's topography and geomorphology, elucidating the mechanisms behind the formation of compression stress zones within an extensional tectonic setting. The study not only challenges the long-held assumption that divergent plate boundaries are solely associated with extensional tectonics but also underscores the indispensable role of interdisciplinary collaboration and the integration of geological processes across different timescales in advancing solid Earth science research.
-
Key words:
- mid-oceanic ridge /
- seismic activity /
- topographic features /
- geodynamics
-
-
图 1 发生在慢速扩张洋中脊的逆冲地震活动以及附近的地形特征（Olive et al., 2024 ）
Figure 1.
图 2 离散板块边界挤压应力区的形成机制（Olive et al., 2024 ）
Figure 2.
-
[1] CESCA S, METZ M, BÜYÜKAKPINAR P, DAHM T. 2023. The energetic 2022 seismic unrest related to magma intrusion at the North Mid-Atlantic Ridge[J]. Geophysical Research Letters,50(13):e2023GL102782. doi: 10.1029/2023GL102782
[2] ESCARTÍN J, COWIE P A, SEARLE R C, ALLERTON S, MITCHELL N C, MACLEOD C J, SLOOTWEG A P. 1999. Quantifying tectonic strain and magmatic accretion at a slow spreading ridge segment, Mid-Atlantic Ridge, 29°N[J]. Journal of Geophysical Research: Solid Earth,104(B5):10421-10437. doi: 10.1029/1998JB900097
[3] FAN Q K, LI J H, LIU Z L, LIU C H. 2019. A quantitative method for active fault migration distance assessment on both sides of Mid‐Ocean ridges—based on Multi‐beam data[J]. Acta Geologica Sinica (English Edition),93(4):810-819. doi: 10.1111/1755-6724.13850
[4] JACKSON J, MCKENZIE D. 2023. Reverse-faulting earthquakes and the tectonics of slowly-spreading mid-ocean ridge axes[J]. Earth and Planetary Science Letters,618:118279. doi: 10.1016/j.jpgl.2023.118279
[5] LIU Z L, BUCK W R. 2018. Magmatic controls on axial relief and faulting at mid-ocean ridges[J]. Earth and Planetary Science Letters,491:226-237. doi: 10.1016/j.jpgl.2018.03.045
[6] LIU Z L, BUCK W R. 2020. Global trends of axial relief and faulting at plate spreading centers imply discrete magmatic events[J]. Journal of Geophysical Research: Solid Earth,125(8):e2020JB019465. doi: 10.1029/2020JB019465
[7] LIU Z L, BUCK W R. 2022. Magmatic sill formation during dike opening[J]. Geology,50(4):407-411. doi: 10.1130/G49400.1
[8] LIU Z L, PÉREZ-GUSSINYÉ M, RÜPKE L, MULDASHEV I A, MINSHULL T A, BAYRAKCI G. 2022. Lateral coexistence of ductile and brittle deformation shapes magma-poor distal margins: an example from the West Iberia-Newfoundland margins[J]. Earth and Planetary Science Letters,578:117288. doi: 10.1016/j.jpgl.2021.117288
[9] OLIVE J A, EKSTRÖM G, BUCK W R, LIU Z L, ESCARTÍN J, BICKERT M. 2024. Mid-ocean ridge unfaulting revealed by magmatic intrusions[J]. Nature,628(8009):782-787. doi: 10.1038/s41586-024-07247-w
[10] OPDYKE N D, GLASS B, HAYS J D, FOSTER J. 1966. Paleomagnetic study of antarctic deep-sea cores: paleomagnetic study of sediments in a revolutionary method of dating events in Earth's history[J]. Science,154(3747):349-357. doi: 10.1126/science.154.3747.349
[11] OU Y, ZHANG J, FENG J, LIU D M, JIA D Y, YANG F, HU Z P, LIN Z Z. 2022. 3D visualization modeling of geological and geophysical data and its application: A case study of Xiong'an New Area[J]. East China Geology,43(3):286-296.
[12] PARNELL-TURNER R, SOHN R A, PEIRCE C, RESTON T J, MACLEOD C J, SEARLE R C, SIMÃO N M. 2017. Oceanic detachment faults generate compression in extension[J]. Geology,45(10):923-926. doi: 10.1130/G39232.1
[13] RUNDQUIST D V, SOBOLEV P O. 2002. Seismicity of mid‐oceanic ridges and its geodynamic implications: a review[J]. Earth‐Science Reviews,58(1-2):143-161.
[14] SCHLINDWEIN V, SCHMID F. 2016. Mid-ocean-ridge seismicity reveals extreme types of ocean lithosphere[J]. Nature,535(7611):276-279. doi: 10.1038/nature18277
[15] SOLOMON S C, HUANG P Y, MEINKE L. 1988. The seismic moment budget of slowly spreading ridges[J]. Nature,334(6177):58-60. doi: 10.1038/334058a0
[16] SYKES L R. 1967. Mechanism of earthquakes and nature of faulting on the mid-oceanic ridges[J]. Journal of Geophysical Research,72(8):2131-2153. doi: 10.1029/JZ072i008p02131
[17] WOLFE C J, BERGMAN E A, SOLOMON S C. 1993. Oceanic transform earthquakes with unusual mechanisms or locations: relation to fault geometry and state of stress in the adjacent lithosphere[J]. Journal of Geophysical Research: Solid Earth,98(B9):16187-16211. doi: 10.1029/93JB00887
[18] YU Z Y, LI J B, DING W W. 2024. Microearthquake reveals the lithospheric structure at mid-ocean ridges and oceanic transform faults[J]. Journal of Oceanology and Limnology,42(3):697-700. doi: 10.1007/s00343-024-3246-2
[19] ZHU H B, CHEN G G, ZHAO D D, ZHANG B S, Di B Y, YU L, YUAN P F. 2022. Application of microtremor survey method in the study of stratum structure: A case study of Binhai New Town, Fuzhou City[J]. East China Geology,43(3):297-305.
[20] 欧洋, 张杰, 冯杰, 刘东明, 贾定宇, 杨峰, 胡志鹏, 林振洲. 2022. 地质-地球物理三维可视化建模及其应用——以雄安新区为例[J]. 华东地质,43(3):286-296.
[21] 朱红兵, 陈国光, 赵东东, 张宝松, 邸兵叶, 于雷, 袁平峰. 2022. 微动探测技术在地层结构研究中的应用——以福州滨海新城核心区为例[J]. 华东地质,43(3):297-305.
-
下载:
图(2)
计量
- 文章访问数: 207
- PDF下载数: 123
- 施引文献: 0