The decline of several of the world's largest deltas has spurred interest in expensive coastal restoration projects to make these economically and ecologically vital regions more sustainable. The success of these projects depends, in part, on our understanding of how delta plains evolve over time scales longer than the instrumental record. Building on a new set of optically stimulated luminescence ages, we demonstrate that a large portion (~10,000 km²) of the late Holocene river-dominated Mississippi Delta grew in a radially symmetric fashion for almost a millennium before abandonment. Sediment was dispersed by deltaic distributaries that formed by means of bifurcations at the coeval shoreline and remained active throughout the life span of this landform. Progradation rates (100 to 150 m/year) were surprisingly constant, producing 6 to 8 km² of new land per year. This shows that robust rates of land building were sustained under preindustrial conditions. However, these rates are several times lower than rates of land loss over the past century, indicating that only a small portion of the Mississippi Delta may be sustainable in a future world with accelerated sea-level rise.

中文翻译：

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密西西比三角洲增长的解剖及其对沿海恢复的影响。

世界上最大的几个三角洲的衰落激发了人们对昂贵的沿海恢复项目的兴趣，以使这些在经济和生态上至关重要的地区更加可持续。这些项目的成功在一定程度上取决于我们对三角洲平原如何在比工具记录更长的时间尺度上演变的理解。基于一组新的光激发发光年龄，我们证明了很大一部分（〜10,000 km ²）晚期的全新世河流占主导的密西西比三角洲以放射状对称的方式生长了近一千年，然后才被放弃。沉积物通过三角洲分流而散布，三角洲分流是通过在古代海岸线上分叉形成的，并在该地貌的整个生命周期中保持活跃。令人难以置信的恒定化速率（每年100至150 m），每年产生6至8 km ²的新土地。这表明在工业化之前的条件下，土地建设的强劲速度得以维持。但是，这些比率比上个世纪的土地流失比率要低几倍，这表明在未来世界中，随着海平面上升的加速，密西西比三角洲的一小部分可能是可持续的。