Located off the coast of Chile , the survival of the fittest account of other inhabitant on the tiny volcanic island of Rapa Nui has long advert archaeologist . Now , a team of researchers believes they ’ve uncover how the ancient island population – between 15,000 and 20,000 at its peak – were able-bodied to observe their fellowship for centuries in the absence of an fair to middling supply of novel water , and what led them to famously construct hundreds of massive statue known as moai .
An eighteenth - century account of European first contact with the Pacific Islanders detailed aboriginal being able to drink brine without harm – a feat we all bang is insufferable today ( the human body cannotprocesshigh concentration of seawater , eventually killing a person through dehydration ) . By 1887 , the local population of Easter Island dropped to just 110 largely due to slave trading and disease , decimating any chance of uncovering the hoi polloi ’s unwritten history .
A team of researchers conduct two subject field surveys across the island . With the elision of two unmanageable - to - admittance lake and a stream that often call on to a wetland peat bog , they found that Easter Island does not have a substantial reference of freshwater .
" The porous volcanic soils quickly absorb rain , result in a lack of stream and river , " said study author Carl Lipo in astatement .
So the squad turn to the 4 - meter - tall ( 13 - feet ) statue posit along the coast for guidance .
When it rain down , urine beneath the ground flow downhill and exits the soil where the rock suffer the ocean . When lunar time period are low , this “ results in the flow of fresh water flat into the sea . ” The tonic and saltwater mix to create a “ brackish but potable water along the coastline ” that moderate grim enough levels of salt to be safely consume by humans , which the researchers guess the island-dweller must have done .
“ Although coastal groundwater germ are of miserable quality , they were plain sufficient to corroborate the universe and allow them to build glorious statutes for which Easter Island is famous , ” wrote the writer in their bailiwick published inHydrogeology .
It ’s intend the 4 - metre - marvelous ( 13 foot ) statue located in these areas were indicative of groundwater that was muster out , enabling early indweller to skim freshwater from the surface , build trenches , or create other coastal impounding . These reserve would have helped the Rapa Nui survive periods of drouth by diversifying their body of water source .
However , others argue that belittled cisterns encounter on the island could have been used for collecting rainfall . Lipo debate that if collecting rainfall was primal to the civilization , then the cistern would have been much large ( they only concord between 2 - 4 litre of weewee each ) . Furthermore , Rapa Nui only encounter 1,240 millimeters of rain every year . Paired with the rate of piddle evaporation here , the cisterns would likely have only been a viable source of water for less than one - third of the year .
In their next trip , the team hopes to explore how the handiness of freshwater in sure fix could be linked to how the large statue were build .
