Field investigations of an ancient fortress wall in southern Myanmar reveal an offset of ~6 m across the Sagaing fault, the major right-lateral fault between the Sunda and Burma plates. The fault slip rate implied by offset of this 16th-century fortress is between 11 and 18 cm yr^(–1). A palaeoseismological excavation within the fortress reveals at least two major fault ruptures since its construction. The slip rate we obtained is comparable to geodetic and geological estimates farther north, but is only 50 per cent of the spreading rate (38 mm yr^(–1)) at the Andaman Sea spreading centre. This disparity suggests that other structures may be accommodating deformation within the Burma Plate. We propose two fault-slip scenarios to explain the earthquake-rupture history of the southern Sagaing fault. Using both small offset features along the fault trace and historical records, we speculate that the southern Sagaing fault exhibits a uniform-fault-slip behaviour and that one section of the fault could generate a M7+ earthquake within the next few decades
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机译：对缅甸南部一处古老的堡垒墙进行的实地调查显示，跨越实皆断层（Sunda和缅甸板块之间的主要右侧断层）的偏移量约为6 m。该16世纪堡垒的偏移隐含的断层滑动率在11至18 cm yr ^（– 1）之间。堡垒内的古地震发掘显示，自其建造以来，至少发生了两次重大断层破裂。我们获得的滑移率可与更北部的大地测量和地质估计相媲美，但仅为安达曼海扩散中心扩散速度（38 mm yr ^（– 1））的50％。这种差异表明其他结构可能正在适应缅甸板块内部的变形。我们提出了两种断层滑移情景，以解释实皆南部断层的地震破裂历史。利用沿断层迹线的小偏移特征和历史记录，我们推测实皆南部断层表现出统一的断层滑动特性，并且断层的一部分可能在未来几十年内引发M7 +地震。
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