王振山, 魏东平, 徐佳静, 王少坡. 2019: 走滑断层对洋中脊热结构与流动场的影响规律及对太平洋南部边界RRF型三联点的解释. 地震学报, 41(4): 459-471. DOI: 10.11939/jass.20180009
引用本文: 王振山, 魏东平, 徐佳静, 王少坡. 2019: 走滑断层对洋中脊热结构与流动场的影响规律及对太平洋南部边界RRF型三联点的解释. 地震学报, 41(4): 459-471. DOI: 10.11939/jass.20180009
Wang Zhenshan, Wei Dongping, Xu Jiajing, Wang Shaopo. 2019: Effects of the strike-slip fault on the thermal structure and mantle flow of the mid-ocean ridge and the interpretation to RRF triple junctions at the southern Pacific boundary. Acta Seismologica Sinica, 41(4): 459-471. DOI: 10.11939/jass.20180009
Citation: Wang Zhenshan, Wei Dongping, Xu Jiajing, Wang Shaopo. 2019: Effects of the strike-slip fault on the thermal structure and mantle flow of the mid-ocean ridge and the interpretation to RRF triple junctions at the southern Pacific boundary. Acta Seismologica Sinica, 41(4): 459-471. DOI: 10.11939/jass.20180009

走滑断层对洋中脊热结构与流动场的影响规律及对太平洋南部边界RRF型三联点的解释

Effects of the strike-slip fault on the thermal structure and mantle flow of the mid-ocean ridge and the interpretation to RRF triple junctions at the southern Pacific boundary

  • 摘要: 选取太平洋板块南部边界的板块相对运动速度不同的两个洋脊-洋脊-转换断层(RRF)型三联点,即麦夸里(Macquarie)三联点和南太平洋三联点,为研究对象,通过数值模拟的方法,研究该类型三联点走滑断层边界两侧的板块相对运动速度对三联点附近地区地幔流动场和温度结构的影响。模拟结果表明:太平洋南部边界RRF三联点走滑断层边界两侧的板块相对运动速度控制着三联点附近的温度分布和地幔流动;随着走滑断层边界两侧板块相对运动速度的增加,转换断层相对滑动速度增加,温度上升,距洋脊边界100 km范围内的地幔流体速度变大;麦夸里三联点和南太平洋三联点处3个板块的相对运动,使得三联点的转换断层边界浅部产生剪应力集中,导致震源深度集中在15—25 km;同时相对运动产生的地幔流动引起温度结构变化,该变化控制着地形变化。

     

    Abstract: Triple junction provides a natural place for studying the interaction of plates. In this paper, we chose two ridge-ridge-fault (RRF) triple junctions with different relative plate velocities at the southern boundary of the Pacific Plate, namely, the Macquarie triple junction and the South Pacific triple junction. We studied the effects of relative plate velocity of the strike-slip fault on the mantle flow and temperature structure of the RRF triple junction by numerical simulation method. We can conclude the following results: ① The relative plate velocity of the strike-slip fault of RRF triple junctions at the southern boundary of the Pacific controls the mantle flow and temperature distribution near triple junctions. ② With increase of the relative plate velocity of the strike-slip fault, the slip velocity of the transform fault and the temperature increases, while the effect on the velocity distribution of mantle fluid concentrates within 100 km from the boundary of the ridge. ③ The relative movement of the three plates at the Macquarie triple junction and the South Pacific triple junction makes the shear stress concentrate in the shallow boundary of the transform fault, which results in the centralized distribution of earthquakes with focal depth in a range of 15−25 km. ④ The topography is mainly controlled by the change of the mantle temperature from the mantle flow caused by the relative motion of plates.

     

/

返回文章
返回