Drought, freshwater availability and cultural resilience on Easter Island (SE Pacific) during the Little Ice Age
- Subject Areas
- Ecology, Coupled Natural and Human Systems, Climate Change Biology, Environmental Impacts, Food, Water and Energy Nexus
- Easter Island, Rapa Nui, lakes, Little Ice Age, drought, cultural change, coastal seeps, paleoecology, brackish water, groundwater, freshwater, archaeology
- © 2019 Rull
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2019. Drought, freshwater availability and cultural resilience on Easter Island (SE Pacific) during the Little Ice Age. PeerJ Preprints 7:e27681v2 https://doi.org/10.7287/peerj.preprints.27681v2
After decades of human-deterministic explanations for the collapse of the ancient Rapanui culture that inhabited Easter Island (Rapa Nui) before European contact (1722 CE), paleoecological studies developed over the last decade have provided sound evidence of climate changes and their potential socioecological impacts. Especially significant is the occurrence of a century-scale (1570-1720 CE) drought occurred during the Little Ice Age. Freshwater is a critical resource on Easter Island that heavily depends on rain, which maintains the only three permanent surficial freshwater sources on the island: two lakes (Rano Kao and Rano Raraku) and a marsh (Rano Aroi). Under these conditions, the LIA drought could have significantly affected human life; however, the Rapanui society remained healthy, showing remarkable resilience. There are two main hypotheses on how the ancient Rapanui could have obtained freshwater to guarantee its continuity. The intra-island migration hypothesis proposes that Rano Raraku, the cultural center of this culture, dried out and the Rapanui were forced to migrate to Rano Kao, which was likely the only surficial freshwater source during the LIA drought. This shift was accompanied by a profound cultural reorganization. The coastal groundwater hypothesis dismisses the use of lakes and other surficial freshwater sources to maintain the water-stressed Rapanui population and contends that the only routine freshwater sources during the LIA drought were the abundant and widespread coastal seeps fed by fresh/brackish groundwater. The pros and cons of these two hypotheses are discussed on the basis of the available archeological and paleoecological evidence, and it is concluded that in the present state of knowledge, neither can be rejected. Therefore, these two proposals could be complementary, rather than mutually exclusive.
The manuscript has been modified after the comments of two colleagues and edited for grammar and style. A figure (2) has been added and two figures (1 and 3) have been modified. The manuscript has been formatted to be submitted to a journal.