The retreat of glaciers in response to climate warming leads to substantial changes in meltwater and sediment yield. Glacial shrinkage also induces the emergence and growth of proglacial margin landforms which strongly affect water and sedimentary transfers from the glacier to the outwash plains. On a decadal-timescale, field observations show that outwash plains of retreating glaciers typically exhibit proximal incision which decreases in magnitude downstream and stops at an inflection point where aggradation begins. Nevertheless, there is a lack of knowledge about the rates and magnitude of this fluvial adjustment and the effects of the proglacial margin configuration on the temperance or the aggravation of this fluvial adjustment to glacier retreat. This paper investigates the proglacial rivers of 14 retreating glaciers in southeast Iceland over a post-Little Ice Age timescale, combining fluvial deposits mapping, lichenometric dating and long-profile measurements of proglacial fluvial terraces. Our results demonstrate that: (1) proximal incision, associated with distal aggradation and downstream migration of the inflection point is the dominant pattern of proglacial river response to post-LIA glacier retreat in Iceland; (2) estimated mean rates of downstream migration of the inflection point range between 5 and 46 m.a-1 ; (3) the downstream migration rate of the inflection point is positively correlated with the proportion of proglacial lakes within the glacier foreland. These findings suggest that proglacial margins dominated by proglacial lakes intensify the rates of proximal incision and inflection point migration

中文翻译：

---

前冰河中的切割和加成：小冰河时代后冰岛南部的长剖面调整淹没平原

冰川因气候变暖而退缩，导致融水和沉积物产量发生重大变化。冰川收缩还导致前冰期边缘地貌的出现和生长，这强烈影响了从冰川到外冲平原的水和沉积物转移。在十年时间尺度上，实地观察表明，退缩冰川的外冲平原通常表现出近端切口，其在下游的幅度减小，并在开始加积的拐点处停止。然而，人们对这种河流调整的速率和幅度以及前冰期边缘配置对这种河流调整对冰川退缩的节制或加剧的影响缺乏了解。本文研究了小冰河时代后冰岛东南部 14 条退缩冰川的前冰河，结合了河流沉积物测绘、地衣测年和前冰河阶地的长剖面测量。我们的研究结果表明：（1）近端切口，与拐点的远端积聚和下游迁移相关，是前冰河对冰岛后 LIA 冰川退缩的主要响应模式；(2) 估计的拐点下游迁移平均速率介于 5 到 46 ma-1 之间；(3)拐点向下游迁移速率与冰川前陆内原冰湖比例呈正相关。