Tectonophysics最新文献_第4页

Tectonics of East Indian Subcontinent: As derived from Integrated Gravity Anomalies of India, Bangladesh, Bay of Bengal and Myanmar Regions 东印度次大陆的构造：来自印度、孟加拉国、孟加拉湾和缅甸地区的综合重力异常

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-06 DOI: 10.1016/j.tecto.2025.231061

J.V. Rama Rao , Ravi Kumar Bandi , T.R.K. Chetty

The East Indian Subcontinent (EISC) is a geologically complex region recording tectonic evolution from the Proterozoic era to the present. This study integrates terrestrial, marine, and satellite gravity data across ∼5 million sq. km covering eastern India, Bangladesh, the Bay of Bengal, and Myanmar, along with earthquake incidences from the past 120 years to unravel the tectonic framework of the region.

A Key focus of this study is building the interrelations among major Proterozoic orogenic belts—Central Indian Tectonic Zone (CITZ), Eastern Ghats Mobile Belt (EGMB), Chhotanagpur Granite Gneissic Complex (CGGC), and Shillong Meghalaya Gneissic Complex (SMGC). From this study, we propose a possible eastern boundary of the CITZ marked as Lucknow–Varanasi–Ranchi lineament, highlight the remarkable affinities between eastern CGGC and EGMB, and redefine the Eastern Continental Margin of India.

Gravity analysis delineates the disposition of collision zones of EISC besides inferring five tectonic domains of EISC, crustal boundaries, plate margins, and transitions from continental to oceanic crust. It also reveals heterogeneity over submarine ridges and the segmentation of the India–Myanmar subduction zone. Aseismic central segment, bounded by cross-faults, is an explicit inference of our study about current Indo-Australian plate subduction dynamics beneath the Sunda–Myanmar Plate.

东印度次大陆（EISC）是一个地质复杂的地区，记录了从元古代到现在的构造演化。这项研究整合了约500万平方英尺的陆地、海洋和卫星重力数据。覆盖了印度东部、孟加拉国、孟加拉湾和缅甸，以及过去120年的地震事件，从而揭开了该地区的构造框架。建立元古代主要造山带—印度中部构造带（CITZ）、东高止山脉活动带（EGMB）、Chhotanagpur花岗片麻岩杂岩（CGGC）和西隆-梅加拉亚片麻岩杂岩（SMGC）之间的相互关系是本研究的重点。在此基础上，我们提出了Lucknow-Varanasi-Ranchi界线作为CITZ可能的东部边界，强调了CGGC东部与EGMB之间的显著亲和性，并重新定义了印度东部大陆边缘。重力分析除了推断出东陆板块碰撞带的5个构造域、地壳边界、板块边缘和陆壳向洋壳过渡外，还圈定了东陆板块碰撞带的配置。它还揭示了海底脊的非均质性和印缅俯冲带的分段性。以交叉断裂为界的地震中心段是我们对巽他-缅甸板块下现今印澳板块俯冲动力学研究的明确推论。

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引用次数: 0

Polyphasic deformation during the evolution of the southern Central Andes: Insights from the La Ramada fold-thrust belt (32°-32°30′S) 中安第斯山脉南部演化过程中的多相变形：来自La Ramada褶皱冲断带（32°-32°30’s）的启示

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-06 DOI: 10.1016/j.tecto.2026.231070

Nicolás Alejandro Peluffo , Lucas Martín Fennell , Sarah Ellen Thomas , Federico Exequiel Martos , Victor Valencia , Andrés Folguera , Maximiliano Naipauer

This work presents an update of the evolution of the La Ramada fold-thrust belt (∼32°S-32°30′S), located in a remote area of the Principal Cordillera of Argentina, integrating two measured stratigraphic sections, novel field observations, and three new zircon UPb ages: two detrital and one igneous. Our new stratigraphic framework includes Paleocene to Miocene sedimentary and volcanic rocks, a period previously interpreted as a hiatus in the area. This sheds light on an enigmatic stage in the evolution of the Andes at these latitudes. We describe the Teatinos Formation, a sedimentary unit with a maximum depositional age of 11.2 ± 0.2 Ma at its base. These rocks were deposited in the Teatinos Basin, a newly defined piggyback basin developed within the Principal Cordillera, representing the innermost expression of the Miocene Andean foreland basin system at these latitudes. A new UPb crystallization age of 19.1 ± 0.5 Ma, obtained from a sill intruding ∼900 m of volcanic rocks, confirms the presence of the late Eocene - early Miocene Abanico Formation in an anomalous position, up to 5 km east of the eastern boundary of the Abanico Basin. This boundary is represented in our area by the Major Andean Fault, a first-order structure that juxtaposes rocks of the western Principal Cordillera over the Teatinos Formation. We also present a new maximum depositional age of 145.2 ± 1.5 Ma from sedimentary rocks in the hanging wall of this fault. These are overlain by the Abanico Formation, defining a > 100 Myr hiatus compatible with the existence of a pre-Oligocene contractional event. We propose a polyphasic evolution for the La Ramada fold-thrust belt involving at least three contractional pulses: one pre-Oligocene and two during the Miocene (ca. 22–18 Ma and ca. 12–9 Ma).

本文对位于阿根廷Principal Cordillera偏远地区的La Ramada褶皱冲断带（~32°S-32°30’s）的演化进行了更新，整合了两个测量的地层剖面、新的野外观测和三个新的锆石UPb年龄：两个碎屑和一个火成岩。我们的新地层格架包括古新世到中新世的沉积岩和火山岩，这一时期以前被解释为该地区的裂谷期。这揭示了安第斯山脉在这些纬度的演化过程中的一个神秘阶段。我们描述了Teatinos组，这是一个沉积单元，其底部的最大沉积年龄为11.2 ± 0.2 Ma。这些岩石沉积在Teatinos盆地中，Teatinos盆地是在Principal Cordillera内发育的一个新定义的背驮式盆地，代表了中新世安第斯前陆盆地体系在这些纬度的最内部表达。新的UPb结晶年龄为19.1 ± 0.5 Ma，来自仍侵入~900 m的火山岩，证实了晚始新世-早中新世Abanico组在Abanico盆地东部边界以东5 km的异常位置存在。这个边界在我们的地区由安第斯大断层代表，这是一个一级结构，将西部主要科迪勒拉的岩石与Teatinos组并列。在断层上盘沉积岩中发现了新的最大沉积年龄145.2 ± 1.5 Ma。它们被Abanico组覆盖，定义了一个 >； 100迈的裂谷，与前渐新世收缩事件的存在相一致。我们提出La Ramada褶皱冲断带的多相演化包括至少三个收缩脉冲：一个前渐新世和两个中新世（约22-18 Ma和约12-9 Ma）。

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引用次数: 0

Reevaluation of geomorphic offsets along the 1920 Haiyuan earthquake rupture, China: A discussion of uncertainties in slip measurements and COPD analyses using high-resolution topography 1920年中国海原地震断裂带沿线地貌偏移的再评价：高分辨率地形对滑动测量和COPD分析不确定性的讨论

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-05 DOI: 10.1016/j.tecto.2026.231071

Longfei Han , Wenqian Yao , Jing Liu-Zeng , Yann Klinger , Chengguo Yan , Peng Wang , Yanxiu Shao

Accurate measurements of coseismic slip distributions derived from geomorphic markers provide essential insights into earthquake rupture dynamics and make a significant contribution to seismic hazard evaluation. With the increased availability of high-resolution topographic data and advanced statistical techniques such as cumulative offset probability distribution (COPD), reconstructing single-event coseismic displacement from cumulative offsets of successive paleoearthquakes has become more feasible. However, assessing the reliability of these methods remains critical. The 1920 Mw7.9 Haiyuan earthquake, the most recent major event along the strike-slip Haiyuan fault, serves as an ideal case study due to notable discrepancies in previously reported displacement measurements. In this study, we utilize very high-resolution (0.1 m) topographic data derived from aerial imagery processed via the Structure from Motion (SfM) technique, covering approximately 85 km of the ∼240 km rupture length. Our analysis, based on detailed horizontal slip measurements and COPD calculation, yields a maximum displacement of 7.6 ± 0.8 m for the 1920 Haiyuan earthquake, differing from previous estimates but aligning well with global scaling relationships for strike-slip earthquakes. Our results reveal three COPD peaks in the geomorphic records along the Haiyuan fault. The displacement interval between the two most recent peaks is similar to that of the latest peak, with reduced displacement observed in the western section. These findings suggest that previous interpretations of four to five events may significantly overestimate single-event slip. Comparisons with previous studies underscore the methodological challenges in COPD-based reconstructions, including uncertainties from different slip measurement methods, geomorphic marker interpretations, fault geometry, along-strike slip variability, and the contribution of moderate-magnitude earthquakes to cumulative offsets.

从地貌标志中得到的同震滑动分布的精确测量为地震破裂动力学提供了重要的见解，并对地震危险性评估做出了重大贡献。随着高分辨率地形数据的可用性和累积偏移概率分布（COPD）等先进统计技术的增加，利用连续古地震的累积偏移重建单事件同震位移变得更加可行。然而，评估这些方法的可靠性仍然至关重要。1920年海原Mw7.9地震是海原走滑断层最近的一次重大地震，由于以前报道的位移测量值存在显著差异，因此可以作为一个理想的研究案例。在这项研究中，我们使用了非常高分辨率（0.1 m）的地形数据，这些数据来自通过运动构造（SfM）技术处理的航空图像，覆盖了约240公里断裂长度中的85公里。我们的分析基于详细的水平滑动测量和COPD计算，得出1920年海原地震的最大位移为7.6±0.8 m，与之前的估计不同，但与走滑地震的全球尺度关系很好地吻合。结果表明，在海原断裂沿线的地貌记录中存在3个慢阻肺峰值。两个最近的峰值之间的位移间隔与最近的峰值相似，但在西段观测到的位移较小。这些发现表明，以前对四到五个事件的解释可能大大高估了单事件滑动。与以往研究的对比强调了基于copd的重建在方法上的挑战，包括不同滑动测量方法的不确定性、地貌标志解释、断层几何形状、沿走滑变异性以及中震级地震对累积偏移量的贡献。

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引用次数: 0

Timing of India-Asia diachronous collision: A view from the westernmost Indian margin, Pakistan 印度-亚洲历时碰撞的时机：从印度最西端边缘，巴基斯坦的视角

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-03 DOI: 10.1016/j.tecto.2025.231067

Muhammad Qasim , Owais Tayyab , Lin Ding , Javed Iqbal Tanoli , Muhammad Awais , Kamran Tabassum , Fulong Cai , Zhang Dingding , Ishtiaq A.K. Jadoon

The India-Asia collision along the western Indian Plate margin remains debated, with contrasting models for the first arrival of Asian-derived detritus in the region. The Sulaiman Fold–Thrust Belt (SFB) in southwestern Pakistan preserves a crucial record of this transition, with the Paleocene to Eocene stratigraphic succession providing insights into sediment provenance shifts. To constrain the collision timing, we analyzed detrital zircon for U-Pb-Hf geochronology, supplemented by petrography and zircon Th/U geochemistry, from Cenozoic sequences exposed in the Mughalkot section, SFB. Detrital zircon age distributions from the Paleocene Dunghan Formation are dominated by ∼500–1100 Ma, ∼1400–2000 Ma, and ∼ 2400–2600 Ma grains, indicating a primary sediment source from the Indian Plate. A similar detrital zircon age pattern in the early to middle Eocene Ghazij Formation suggests continued derivation from the Indian craton. However, a pronounced provenance shift is observed in the lowermost Baska Formation (middle Eocene), marked by the arrival of Late Cretaceous–Paleocene (<100 Ma) detrital zircons, which possess Th/U ratios (>0.3) indicative of an igneous origin. Juvenile Hf signatures of the younger detrital zircons further support their derivation from the Kohistan-Ladakh Arc, which is located between the Indian and the Asian plates in North Pakistan. The arrival of this detritus signals the onset of the India-Asia collision, constrained by the maximum depositional age to post–51 Ma. When compared to northern and central segments of the Himalayan orogen, this suggests a diachronous collision with its later onset in the westernmost region. These findings contribute to the broader framework of India-Asia convergence, supporting models that invoke regional variability in collision timing and foreland basin evolution.

沿着西印度板块边缘的印度-亚洲碰撞仍然存在争议，对于亚洲来源的碎屑首次到达该地区，存在不同的模型。巴基斯坦西南部的苏莱曼褶皱冲断带（SFB）保存了这一转变的重要记录，古新世到始新世的地层演替为沉积物物源转移提供了见解。为了约束碰撞时间，我们分析了SFB Mughalkot剖面新生代序列的碎屑锆石U- pb - hf年代学，并补充了岩石学和锆石Th/U地球化学。古新世Dunghan组碎屑锆石年龄分布以~ 500 ~ 1100 Ma、~ 1400 ~ 2000 Ma和~ 2400 ~ 2600 Ma颗粒为主，表明其主要沉积源来自印度板块。始新世早至中Ghazij组的碎屑锆石年龄模式相似，表明其继续源自印度克拉通。然而，在巴斯卡组最下部（中始新世），物源转移明显，标志着晚白垩世-古新世（<100 Ma）碎屑锆石的到来，其Th/U比（>0.3）表明其成因为火成岩。这些碎屑的到来标志着印度-亚洲碰撞的开始，受最大沉积年龄限制在51 Ma之后。与喜马拉雅造山带的北部和中部部分相比，这表明在最西部地区发生的碰撞较晚，是一次历时性碰撞。这些发现有助于建立更广泛的印度-亚洲辐合框架，支持碰撞时间和前陆盆地演化的区域变异性模型。

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引用次数: 0

Mesozoic differential uplift-exhumation processes in the western Tian Shan, Uzbekistan: Constraints from apatite/zircon fission track and (UTh)/He thermochronology 乌兹别克斯坦西天山中生代差异性隆升-掘出过程：磷灰石/锆石裂变径迹和(U - Th)/He热年代学的约束

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-03 DOI: 10.1016/j.tecto.2026.231068

Weini Zhang , Wengao Zhang , Fengbin Han , Jian Chang , Hailong Huo , Jiayong Pan , Bakhtiar Nurtaev , Shukhrat Shukurov , Zhengle Cheng

The western Tian Shan in Uzbekistan, forming the orogen's western terminus, provides critical insights into Meso-Cenozoic tectonic evolution through its uplift-exhumation history. This study integrates apatite/zircon fission-track (AFT/ZFT) and zircon (UTh)/He analyses on 15 granitic samples from the Kyzylkum Nurata segment. Key findings include: (1) AFT ages span 67.50 ± 10.03–215.31 ± 14.53 Ma, with short mean track lengths (11.47 ± 1.38–12.65 ± 0.75 μm), indicating partial thermal resetting.(2)The western Tian Shan experienced Meso-Cenozoic multi-phase rapid uplift-exhumation, revealing a progressive northwest-to-southeast younging of apatite fission track ages and a marked contrast in exhumation regimes between the northwestern Nurata Range and adjacent ranges within the Kyzylkum-Nurata segment, highlighting spatiotemporal migration of tectonic activity and localized deformation partitioning. (3) Three thermo-tectonic phases were identified: Triassic rapid exhumation responding to Turan-Qiangtang/Paleo-Asia collision; Jurassic-Early Cretaceous uplift controlled by Lhasa-Qiangtang collision effects; Late Cretaceous-Cenozoic burial-rejuvenation cycles linked to Kohistan-Dras arc accretion in the Late Cretaceous and India-Eurasia/Kunlun-Pamir collisions in the Cenozoic. Differential exhumation patterns reflect inherited crustal heterogeneity, suture zone reactivation, and far-field stresses from Tethyan plate interactions. This study fills critical gaps in understanding Meso-Cenozoic uplift-exhumation processes in the westernmost Tian Shan, providing enhanced constraining models for the tectonic evolution of the entire orogen. Based on the investigation into the dynamic origins of uplift and exhumation, it can be concluded that the trend of uplift and exhumation in the Kyzylkum-Nurata segment of the Western Tian Shan propagated from southeast to northwest.

乌兹别克斯坦西天山形成了造山带的西端，通过其隆升-掘出历史，为中新生代构造演化提供了重要的认识。本文对Kyzylkum Nurata段15个花岗岩样品进行了磷灰石/锆石裂变径迹（AFT/ZFT）和锆石（UTh /He）分析。主要发现包括：(1)AFT年龄跨度为67.50±10.03 ~ 215.31±14.53 Ma，平均径迹长度较短（11.47±1.38 ~ 12.65±0.75 μm），表明部分热复位；(2)天山西部经历中新生代多期快速隆升掘出，磷灰石裂变径迹年龄由西北向东南渐进性年轻化，努拉塔山脉西北部与kyzylkm -Nurata段相邻山脉的掘出制度对比明显，突出了构造活动的时空迁移和局部变形分区。(3)确定了三个热构造阶段：三叠纪快速掘出响应吐兰-羌塘/古亚洲碰撞；拉萨-羌塘碰撞作用控制侏罗纪-早白垩世隆升；晚白垩世-新生代埋藏-恢复旋回与晚白垩世Kohistan-Dras弧增生和新生代印度-欧亚/昆仑-帕米尔碰撞有关。不同的挖掘模式反映了继承的地壳非均质性、缝合带的重新激活和特提斯板块相互作用的远场应力。该研究填补了认识天山最西端中新生代隆升-掘出过程的关键空白，为整个造山带的构造演化提供了强化的约束模式。通过对隆升和掘出动力成因的研究，认为西天山克孜库姆—努拉塔段隆升和掘出趋势是由东南向西北扩展的。

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引用次数: 0

Multi-mode pre-seismic geomagnetic anomalies reveal potential mechanisms of the August 15, 2007, Mw8.0 Pisco earthquake: Pressure-stimulated rock current 多模态震前地磁异常揭示了2007年8月15日Mw8.0皮斯科地震的潜在机制：压力刺激的岩石流

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-02 DOI: 10.1016/j.tecto.2025.231065

Busheng Xie , Lixin Wu , Licheng Sun , Youyou Xu , Akimasa Yoshikawa , Wenfei Mao

This study investigates multi-type pre-seismic geomagnetic anomalies observed before the August 15, 2007, M_w 8.0 Pisco earthquake, and proposes Pressure-Stimulated Rock Current (PSRC) as an underlying mechanism. Using time-domain and frequency-domain analyses, the research identifies ultra-low frequency (ULF) emissions and magnetic vector deflections related to the earthquake. Based on the diurnal variation anomalies across multiple stations, a novel algorithm, the Forward Intersection of Magnetic Disturbance Vector (FIMDV), was developed to estimate the location of the seismogenic zone by analyzing the magnetic vector deflection. The FIMDV algorithm integrates the magnitude and directional information of magnetic disturbance vectors to pinpoint rock currents, providing new insights into geomagnetic anomalies and earthquake preparation. The study identifies two key phases of potential PSRC generation: the crack coalescence phase, associated with ULF emissions detected a month before the earthquake, and the crack interconnection phase, which corresponds to diurnal anomalies observed on the earthquake day. The former involves microcrack formation and positive hole activation, leading to varying electromagnetic fields that propagate as low-frequency waves detectable at the ground surface. The latter involves cracks interconnection facilitating the propagation of direct rock currents to the ground surface and inducing stable magnetic disturbance vectors. Geological validation confirmed that the local lithology, rich in silicate minerals, enables positive holes activation and propagation, further supporting PSRC as a driving mechanism of the observed multi-mode geomagnetic anomalies, including diurnal variation, vector deflection, Z/H polarization ratio, and horizontal polarization ellipse.

本文对2007年8月15日mw8.0 Pisco地震前观测到的多类型震前地磁异常进行了研究，并提出压力刺激岩石电流（PSRC）是其潜在机制。通过时域和频域分析，该研究确定了与地震有关的超低频（ULF）发射和磁矢量偏转。基于多台站的日变化异常，提出了一种新的算法——磁扰动矢量正向交会（FIMDV），通过分析磁矢量偏转来估计孕震带的位置。FIMDV算法集成了磁扰动矢量的震级和方向信息来精确定位岩石电流，为地磁异常和地震准备提供了新的见解。该研究确定了潜在PSRC产生的两个关键阶段：裂缝合并阶段，与地震前一个月检测到的超低辐射辐射有关；裂缝互连阶段，与地震当天观测到的日异常相对应。前者涉及微裂纹的形成和正孔激活，导致不同的电磁场以低频波的形式传播，在地表可探测到。后者涉及裂缝互连，有利于直接岩石电流向地表传播，并产生稳定的磁扰动矢量。地质验证证实，局部岩性富含硅酸盐矿物，有利于孔洞的激活和扩展，进一步支持PSRC是观测到的多模地磁异常（包括日变化、矢量偏转、Z/H极化比和水平极化椭圆）的驱动机制。

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引用次数: 0

Controls of temperature on seismic moment released from reactivated faults 重新激活的断层释放的地震力矩的温度控制

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-02 DOI: 10.1016/j.tecto.2025.231062

Junpeng Wang , Agathe Eijsink , Matthew Roseboom , Chris Marone , Jacques Riviere , Parisa Shokouhi , Derek Elsworth

Induced seismicity is the main uncertainty to safely produce geothermal energy, raising questions as to how applicable known physical laws are at increased temperatures. We explore the impact of elevated temperatures on maximum seismic moments anticipated in induced seismicity. We conduct laboratory reactivation experiments on a single inclined fracture (SIF) at equilibrated temperatures of 23 °C, 78 °C and 137 °C. Fractures are loaded at a constant shear stress of ∼80 % of the peak shear strength with slip activated by fluid injection. Reactivated seismic moments scale linearly with volume injected but decrease by one-order-of-magnitude with incremented temperatures over the range 23–137 °C. We provide a new perspective of temperature influence on fracture shearing – emphasizing the role of fracture properties (stiffnesses) of elastic tangential and normal stiffnesses on the energetics of slip. We use these stiffnesses to define a relationship linking injected volume to the resulting seismic moment. In transiting from 23 °C to 137 °C, tangential stiffness is halved and normal stiffness quadrupled, thus the resulting seismic moment is potentially reduced by a factor of eight – congruent with observations of reactivated seismic moments over the same temperature range. The change in stiffness can be explained by an increasing contact area, which we also observe by P wave measurements. Our results suggest that increased temperature inhibits fault seismicity and the expected maximum seismic moment of induced seismicity.

诱发地震活动是安全生产地热能的主要不确定因素，这就提出了已知物理定律在温度升高时如何适用的问题。我们探讨了高温对在诱发地震活动中预期的最大地震矩的影响。我们在23°C、78°C和137°C的平衡温度下对单个倾斜裂缝（SIF）进行了实验室再激活实验。裂缝在恒定剪切应力下加载，剪切应力为峰值剪切强度的80%，并由流体注入激活滑移。重新激活的地震矩与注入体积呈线性关系，但在23-137℃范围内，随着温度的增加，地震矩会减小一个数量级。我们提供了温度对断裂剪切影响的新视角-强调弹性切向和法向刚度的断裂特性（刚度）对滑移能量学的作用。我们使用这些刚度来定义注入体积与产生的地震力矩之间的关系。从23°C过渡到137°C时，切向刚度减半，法向刚度翻了两番，因此产生的地震矩可能减少了8倍，这与在相同温度范围内重新激活的地震矩的观测结果一致。刚度的变化可以用接触面积的增加来解释，我们也通过P波测量观察到这一点。研究结果表明，温度升高抑制了断层地震活动性和诱发地震活动性的预期最大地震矩。

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引用次数: 0

Multi-source geodetic constraints on 3D crustal deformation, strain accumulation, and fault locking in the Tianshan Orogen 天山造山带三维地壳变形、应变聚集和断层锁闭的多源大地测量约束

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-01 DOI: 10.1016/j.tecto.2025.231063

Jiangtao Qiu , Jianbao Sun , Lingyun Ji , Liangyu Zhu

The Tianshan orogen, located at the northern margin of the India–Eurasia collision zone, is one of the world's most seismically active intracontinental mountain belts. However, a comprehensive understanding of its crustal deformation, strain accumulation, and fault locking patterns remains limited due to the lack of large-scale, high-resolution geodetic observations. In this study, we integrate Sentinel-1 interferometric synthetic aperture radar (InSAR) time-series analysis with regional Global Navigation Satellite System (GNSS) data to reconstruct a three-dimensional (3D) deformation field covering the entire Tianshan range. We apply atmospheric corrections using ERA5 reanalysis and constrain the InSAR solutions with GNSS data to significantly improve their consistency, enabling reliable quantification of crustal motions. Our results reveal pronounced spatial variability in north–south shortening, with rates reaching ∼20 mm/yr in the western segment (75°-79°E) and decreasing to 6–9 mm/yr in the eastern segment (85°-87°E). Uplift rates are higher in the South Tianshan (1.8–2.2 mm/yr) than in the North Tianshan (0.8–1.2 mm/yr), while strike-slip motions are concentrated along the southern foreland. Non-tectonic deformation is also identified, including large-scale subsidence due to groundwater extraction (∼34 mm/yr) and localized oilfield-induced subsidence (∼20 mm/yr). From the 3D deformation field, we derive the strain rate distribution and invert fault locking parameters using a block model with Bayesian optimization. High strain accumulation and strong locking are observed along the Pamir frontal thrust, the Maidan fault (which ruptured in the 2024 Mw 7.1 Wushi earthquake), the south Issyk-Kul fault, the Kepingtag fault (which ruptured in the 2020 Mw 6.0 Jiashi earthquake), and the Qiulitag belt. Our findings highlight the coupled tectonic and anthropogenic processes shaping Tianshan deformation and identify the western Qiulitag as a potential source for future large earthquakes.

天山造山带位于印度-欧亚碰撞带的北缘，是世界上地震最活跃的大陆内山带之一。然而，由于缺乏大规模、高分辨率的大地测量观测，对其地壳变形、应变积累和断层锁定模式的全面了解仍然有限。在这项研究中，我们将Sentinel-1干涉合成孔径雷达（InSAR）时间序列分析与区域全球导航卫星系统（GNSS）数据相结合，重建了覆盖整个天山山脉的三维（3D）变形场。我们使用ERA5再分析进行大气校正，并将InSAR解决方案与GNSS数据进行约束，以显着提高其一致性，从而实现可靠的地壳运动量化。我们的研究结果表明，南北缩短的空间变异性明显，西段（75°-79°E）的速率为~ 20 mm/yr，而东段（85°-87°E）的速率为6-9 mm/yr。南天山隆升速率（1.8 ~ 2.2 mm/yr）高于北天山隆升速率（0.8 ~ 1.2 mm/yr），走滑运动沿南前陆集中。此外，还发现了非构造变形，包括地下水开采引起的大规模沉降（~ 34 mm/yr）和局部油田引起的沉降（~ 20 mm/yr）。从三维变形场出发，利用贝叶斯优化的块体模型推导出应变率分布，反演出断层锁定参数。沿帕米尔前缘逆冲、麦丹断裂（2024 Mw 7.1吴市地震破裂）、南伊塞克-库尔断裂、柯平塔格断裂（2020 Mw 6.0贾市地震破裂）和秋里塔格带观察到高应变积累和强锁断。我们的研究结果强调了构造和人为作用的耦合作用对天山变形的影响，并确定了秋里塔格西部是未来大地震的潜在震源。

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引用次数: 0

Lateral anisotropic gradients in the subslab mantle beneath the Kuril subduction zone detected by observations of quasi-Love wave scattering 准爱波散射观测探测千岛岛俯冲带下地幔横向各向异性梯度

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-01 DOI: 10.1016/j.tecto.2025.231066

Wei Cheng , Xiaogang Hu , Yan Lu , Xinghui Liang , Lintao Liu , Panpan Zhang , Yufeng Zhou

The northwestern part of the Pacific plate is subducting into the Kuril trench at high speed, which is expected to result in strong shear on the underlying mantle asthenosphere. However, the splitting measurements in the Kuril subslab mantle reveal complex patterns of seismic anisotropy along the Kuril subduction zone. Love-to-Rayleigh scattered waves (quasi-Love waves) are straightforward indicators of sharp lateral gradients in the anisotropic properties of the Earth's upper mantle (at depths of 100–200 km). Here, we present observations of quasi-Love waves at stations located in Japan from surface waves that sampled the Kuril subslab mantle. Clear quasi-Love waves were diagnosed from 11 earthquakes. The inferred quasi-Love scatterers are located mainly in central and northern Kuril, suggesting the presence of extensive lateral anisotropic gradients in the Kuril subslab mantle, whereas southern Kuril lacks similar anisotropic gradients in the subslab mantle. The lateral anisotropic gradients in northern Kuril may simply reflect the transition from anisotropic subducted slab to mantle flow in the asthenosphere or reflect local toroidal flow around the slab edges, while the lateral anisotropic gradients in northern Kuril may indicate the regions where subslab mantle flow is significantly deflected. Considering the specific slab geometry in and around the Kuril subduction zone, we infer that the detachment of the subducting northwest Pacific slab beneath the Aleutian–Kamchatka junction and the fast slab rollback in central Kuril may be the driving forces for the generation of lateral anisotropic gradients beneath the central Kuril. Our observations of quasi-Love waves provide new constraints on the mantle anisotropy in Kuril.

太平洋板块西北部正高速向千岛海沟俯冲，预计将对下伏地幔软流圈产生强烈剪切。然而，千岛岛板块下地幔的分裂测量揭示了千岛岛俯冲带地震各向异性的复杂模式。Love-to-Rayleigh散射波（准love波）是地球上地幔（深度100-200公里）各向异性特性的急剧横向梯度的直接指示。在这里，我们介绍了日本站对千岛岛板块下地幔表面波的观测结果。从11次地震中诊断出清晰的准love波。推断的准love散射体主要分布在千岛岛中部和北部，表明千岛岛下地幔存在广泛的横向各向异性梯度，而南千岛岛下地幔则缺乏类似的各向异性梯度。南千岛岛北部各向异性梯度可能仅仅反映了软流圈内各向异性俯冲板块向地幔流动的转变或反映了板块边缘附近的局部环面流动，而北千岛岛北部各向异性梯度可能反映了板块下地幔流动明显偏转的区域。考虑到千岛岛俯冲带内及周边特定的板块几何形状，我们推断阿留申-堪察加交界处下俯冲西北太平洋板块的拆离和千岛岛中部板块的快速回滚可能是千岛岛中部下方横向各向异性梯度产生的驱动力。我们的准love波观测为千岛岛地幔各向异性提供了新的约束条件。

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引用次数: 0

Detailed structure of upper mantle discontinuities beneath the Pamir-Hindu Kush from the short period regional seismic array 来自短周期区域地震阵的帕米尔-兴都库什上地幔不连续体的详细结构

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-12-31 DOI: 10.1016/j.tecto.2025.231064

Yan Xu, Shunping Pei, Xinhua Jia, Chaodi Xie, Mingrui Huang

Two intermediate-depth earthquakes with moment magnitude 5.8 and 5.3 respectively occurred in the Pamir-Hindu Kush in August 2023. We select three subarrays that exhibit a two-dimensional delta-shaped array response function from a temporary regional short-period array. For each event/subarray pair, the data is slant-stacked and normalized with respect to the initial p phase. Two secondary arrivals, P410p and s140p, bring out the information of the upper mantle beneath Pamir-Hindu Kush area. The reflection depth of the P-wave from the 410-km discontinuity suggests that the subducted cold slab of the Hindu Kush penetrates the discontinuity, uplifting it to a shallower depth as the reflection point approaches the cold core. The deepening trend of the reflection depth along the strike of the Pamir slab is consistent with the model that suggests the splitting of the subducted Pamir slab with its western part abutting against the Hindu Kush slab below 350 km. Our data provide a direct sampling of the boundary zone between the abutted Pamir-Hindu Kush slab and the normal mantle material. We observe a P wave, s140p, that was converted from an upgoing S wave at a depth of 140 km. This s140p phase exhibits a rapid drop in energy within a spatially confined, northwest-southeast oriented area, suggesting a near-vertical velocity boundary.

2023年8月，帕米尔高原-兴都库什山脉发生两次矩级分别为5.8级和5.3级的中深度地震。我们从一个临时的区域短周期阵列中选择了三个表现出二维三角形阵列响应函数的子阵列。对于每个事件/子阵列对，数据相对于初始p阶段进行倾斜堆叠和规范化。P410p和s140p两个次级到达带出了帕米尔-兴都库什地区上地幔的信息。从410 km不连续的p波反射深度表明，兴都库什山脉的俯冲冷板块穿过了不连续，当反射点接近冷核时，将其抬升到较浅的深度。反射深度沿帕米尔板块走向的加深趋势与俯冲帕米尔板块西部在350 km以下与兴都库什板块毗邻的分裂模式相一致。我们的数据提供了相邻的帕米尔-兴都库什板块与正常地幔物质之间的边界带的直接采样。我们观测到一个P波，s140p，是由一个上升的S波在140千米的深度转换而来的。这个s140p相在一个空间受限的西北-东南方向区域内表现出能量的快速下降，表明存在一个接近垂直的速度边界。

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引用次数: 0