Image gallery of Potter Cove, King George Island, webcam 2 in 2011

Recent rapid retreat of glacial front lines and the loss of land ice along the Antarctic margins may play an important role in exporting suspended particulate matter (SPM) potentially rich in bioavailable (defined as ascorbate leachable) iron (FeA) to coastal areas of the Southern Ocean. Sediment ablation is an additional source of iron for this high-nutrient low-chlorophyll region. In Potter Cove, King George Island, meltwater streams discharge up to 18 000 mg/l (average 283 mg/l) of slightly weathered, finely ground bedrock particles into coastal waters during the summer. Approximately 15% of this SPM is exported within a low-salinity surface plume into Bransfield Strait. Based on our data, an estimated 12 mg/m**2/yr of FeA is exported from the South Shetland Island land surface (ice-free and subglacial areas) to the surrounding coastal waters. Extrapolated to an area of 2.5x104 km**2, this FeA input is comparable to the contribution from icebergs and c. 240-fold higher than aeolian input via dust. An observed rise in local sediment accumulation rates suggests that glacial erosion has been increasing over recent decades and that (sub-)glacially derived SPM is becoming more important as a source of iron to the Southern Ocean.南极陆缘地带冰川前缘的快速退缩与陆冰流失，可能在向南大洋沿岸海域输送富含生物可利用铁（bioavailable iron，定义为抗坏血酸可浸提态，记为FeA）的悬浮颗粒物（suspended particulate matter, SPM）方面发挥重要作用。对于该高营养盐低叶绿素海区而言，沉积物消融是另一重要铁素来源。在乔治王岛波特湾，夏季融水溪流可向近岸海域排放最高浓度达18000 mg/L、平均浓度为283 mg/L的轻度风化细粒基岩颗粒。其中约15%的悬浮颗粒物会通过低盐度表层羽状流被输送至布兰斯菲尔德海峡。基于本研究数据，估算得到南设得兰群岛陆地表面（无冰区与冰下区域）每年向周边近岸海域输出的FeA通量为12 mg/m²/yr。若将该通量外推至2.5×10⁴平方千米的区域范围，则其FeA输入量与冰山贡献量相当，且约为大气粉尘输入量的240倍。观测到的本地沉积物沉积速率上升表明，近几十年来冰川侵蚀作用持续增强，且冰下来源的悬浮颗粒物作为南大洋铁素来源的重要性日益凸显。