Abstract The Andaman–Sumatra–Java subduction zone is characterized by significant spatial variations in subducting plate age, subduction velocity, and slab bending. With (i) the uplifting controlled by the Ninety East Ridge in the north, (ii) trench eroding affected by the Roo Rise in the south, and (iii) the highly deformed Warton Basin in front of the trench cut through by a series of strike-slip faults, the entire subducting plate exhibits strong spatial heterogeneity. In this paper, we investigated the effect of the heterogeneous subducting plate on seismicity based on the comparison between the spatial variations in the b-value of the Gutenberg-Richer Law and in the tectonic features of the subducting oceanic plate. We used the International Seismological Centre, EHB Bulletin (ISC-EHB) from 1970 to 2013 to conduct a detailed study of b-value spatial variations in the Andaman–Sumatra–Java subduction zone. Via the inter-comparison of tectonic factors, we found that the subduction zone was tectonically segmented. There are good positive correlations between b-value and subducting plate age in two tectonic domains after removing the influence of local tectonic irregularities, which implies that the subducting plate density generally controls the stress and coupling between the plates. The subduction of local tectonic irregularities, such as the fracture zones and seamounts, has significantly affected seismicity, which prevents the occurrence of large earthquakes and causes the b-value to rise. In addition, the anomalous tectonic environments, such as the spreading center, and the thrust fault zones, could also impact spatial variations of the b-value. Therefore, seismicity in subduction zones is a result of the combined impacts of complex tectonic features. Understanding and clarifying the mechanisms of these tectonic features in relation to b-values can help us to better assess seismic risk in subduction zones.

中文翻译：

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异质俯冲板块对地震活动的影响：安达曼-苏门答腊-爪哇俯冲带 b 值的约束

摘要 安达曼-苏门答腊-爪哇俯冲带的特征是俯冲板块年龄、俯冲速度和板片弯曲的空间变化显着。(i) 北部受东九十岭控制的抬升，(ii) 南部受 Roo Rise 影响的海沟侵蚀，以及 (iii) 海沟前高度变形的 Warton 盆地被一系列的走滑断层，整个俯冲板块表现出强烈的空间非均质性。在本文中，我们基于古腾堡-里歇尔定律 b 值的空间变化与俯冲大洋板块构造特征的空间变化比较，研究了异质俯冲板块对地震活动的影响。我们使用了国际地震中心，EHB 公告 (ISC-EHB) 从 1970 年到 2013 年对安达曼-苏门答腊-爪哇俯冲带的 b 值空间变化进行了详细研究。通过构造因素的相互比较，我们发现俯冲带在构造上是分段的。去除局部构造不规则的影响后，两个构造域的b值与俯冲板块年龄之间存在良好的正相关，这意味着俯冲板块密度总体上控制了板块之间的应力和耦合。断裂带、海山等局部构造不规则的俯冲对地震活动产生了显着影响，阻止了大地震的发生，使b值升高。此外，扩张中心、逆冲断裂带等异常构造环境，也可能影响 b 值的空间变化。因此，俯冲带的地震活动是复杂构造特征共同作用的结果。理解和阐明与 b 值相关的这些构造特征的机制可以帮助我们更好地评估俯冲带的地震风险。