Rano Raraku geochemical data

A geochemical survey of the water, suspended particulate matter, sediments and soil of the Rano Raraku crater lake basin in Rapa Nui (Easter Island) was performed in order to assess if the lake water could have been a viable fresh water source for early inhabitants, as well as better understanding past interactions between humans and environmental conditions as archived in lake sediments.
At the time of sampling in September 2017, lake maximum depth was 1.5 m. The lake level has substantially declined in the subsequent years, with the lake drying almost completely in January 2018. The lake is currently characterized by highly anoxic conditions, with a predominance of ammonium ions on nitrates, a high concentration of organic carbon in the water-sediment interface and reducing conditions of the lake, as evidenced by Mn/Fe and Cr/V ratios. At the time of sampling, water pH was 7.8.

为评估拉帕努伊（复活节岛）拉诺拉拉库火山口湖的水是否曾作为早期居民的可行淡水来源，并深入理解湖泊沉积物中记录的过去人类与环境条件之间的相互作用，对该地区的水、悬浮颗粒物、沉积物和土壤进行了地球化学调查。在2017年9月采样时，湖的最大深度为1.5米。随后几年中，湖水水平显著下降，2018年1月湖几乎完全干涸。目前，该湖以高度缺氧条件为特征，以氨离子对硝酸盐的占主导地位，水-沉积物界面中有机碳含量高，以及通过Mn/Fe和Cr/V比率体现的湖泊还原条件。采样时，水的pH值为7.8。