Common depth points and associated geographic coordinates

Fluids in subduction zones can influence seismogenic behaviour and prism morphology. The Eastern Makran subduction zone, offshore Pakistan, has a very thick incoming sediment section of up to 7.5 km, providing a large potential fluid source to the accretionary prism. A hydrate-related bottom simulating reflector (BSR), zones of high amplitude reflectivity, seafloor seep sites and reflective thrust faults are present across the accretionary prism, indicating the presence of fluids and suggesting active fluid migration. High amplitude free gas zones and seep sites are primarily associated with anticlinal hinge traps, and fluids here appear to be sourced from shallow biogenic sources and migrate to the seafloor along minor normal faults. There are no observed seep sites associated with the surface expression of the wedge thrust faults, potentially due to burial of the surface trace by failure of the steep thrust ridge slopes. Thrust fault reflectivity is restricted to the upper 3 km of sediment and the deeper décollement is non-reflective. We interpret that fluids and overpressure are not common in the deeper stratigraphic section. Thermal modelling of sediments at the deformation front suggests that the deeper sediment section is relatively dewatered and not currently contributing to fluid expulsion in the Makran accretionary prism.俯冲带内的流体可影响发震行为与增生楔（accretionary prism）形态。位于巴基斯坦近海的东马克兰俯冲带，其外来沉积层厚度可达7.5千米，为增生楔提供了规模可观的潜在流体源。该区域增生楔广泛分布与水合物相关的海底模拟反射层（BSR）、高振幅反射带、海底渗液点以及反射性逆冲断层，这指示了流体的赋存，并暗示存在活跃的流体运移过程。高振幅游离气带与海底渗液点主要与背斜枢纽圈闭相关联，此处的流体似乎源自浅层生物成因来源，并沿小型正断层运移至海底。目前尚未观测到与楔状逆冲断层地表露头相关的渗液点，这可能是由于陡峭逆冲脊斜坡的崩塌掩埋了其地表迹线。逆冲断层的反射信号仅局限于上部3千米的沉积地层中，更深层的拆离面（décollement）无反射特征。我们推断，深层地层内流体与超压并不常见。对变形前缘沉积物的热模拟结果表明，深层沉积层已相对脱水，目前并未向马克兰增生楔贡献流体排溢活动。