World Heritage site: Easter Island
World Heritage sites are internationally recognised as places of outstanding universal cultural and natural value. The second destination feature in our series on World Heritage sites focuses on the recent Aviva/Earthwatch Climate Change Research Award-winning project Easter Island Culture: Climate Change, Human Impacts and Social Transformation.
Easter Island, also known by the Polynesian name Rapa Nui, is located in the South Pacific and is the most isolated inhabited place on Earth, around 2,500 miles from the coast of South America. This extreme isolation was a key influencing factor in the development of the complex hierarchical society that developed on the island. This culture established an advanced tradition of sophisticated architecture and monumental sculpture, which from the 10th to the 16th century created the giant stone figures known as moai. In 1995 the island was inscribed as a UNESCO World Heritage site; the World Heritage Committee concluded that Rapa Nui National Park contains one of the most remarkable cultural phenomena in the world; the remains of this culture combine with their natural surroundings to create an unparallelled cultural landscape.
The date when the Polynesian settlers first arrived on Rapa Nui is hotly debated, but is thought to be around AD 400-600. At this time, the island was covered in a dense forest of palms and other trees. Over the centuries, the inhabitants felled the trees for various reasons, including building canoes, clearing areas to plant crops, providing fuel, and to obtain logs for moving the moai statues from the quarry to their final location. Eventually the island was completely denuded of its forest. As a result of this large-scale deforestation, topsoil began to erode and the productivity of the island decreased. The spectacularly advanced prehistoric culture underwent a rapid and drastic decline about 900 years after settlement. Several competing territorial groups formed, and inter-group wars broke out. Furthermore, the inhabitants were unable to escape from the environmentally impoverished island as there was no longer any wood available for canoe-making. By the time the island was ‘rediscovered' by Dutch explorer Jacob Rogeveen on Easter Sunday 1722, the islanders had suffered a drastic reduction in population and were at the limits of human endurance.
Various schools of thought exist on the causes of the pre-European cultural decline. One widely held theory is that the overexploitation of the tiny island's resources led to the collapse. Many experts view Easter Island as a microcosm of planet Earth; a model that demonstrates the importance of maintaining a sustainable balance between resource use, material goods and cultural expression.
Archaeologist and Earthwatch Principal Investigator Dr. Chris Stevenson (Virginia Department for Historic Resources) is researching the role of climate in the decline of the prehistoric Rapa Nui culture. Dr. Stevenson has proposed that a period of increasing aridity was one of the primary factors implicit in the political reorganisation and overall decline of the traditional society on Easter Island. Dr. Stevenson's team is investigating the climatic trends before and during the Polynesian settlement, and the factors that led to the development and subsequent rapid decline of this society.
Stevenson hypothesises that the inhabitants of Rapa Nui recognised the problems that deforestation and environmental degradation had caused and used new techniques such as rock gardens to help mitigate the effects of increased aridity and wind stress. Other responses included shifting fields to higher elevations to benefit from greater rainfall in those areas. Despite these attempts at adaptation, the research team proposes that the climatic change was prolonged and the decreased availability of water meant it was impossible to maintain surplus production required to maintain the traditional culture.
On the expedition
Volunteers on Easter Island Culture take part in a range of landscape survey and site excavation tasks, including digging, screening, trowelling, map drawing, photography, sample selection, and data management. The field survey team will systematically walk across the landscape, recording prehistoric sites on the surface. This will entail the measurement of stone features, photography, grass clearing, and Global Positioning System (GPS) data collection. Soil samples will be taken from the many prehistoric pits or midden deposits encountered during excavation.
Volunteers stay in a residencia, or small family hotel, in "downtown" Hanga Roa, the only town on Easter Island.
Easter Island fact file
Area: 163 km2
Capital: Hanga Roa
Languages: Spanish, English, Rapa Nui
Government: Special Territory of Chile
Currency: Chilean peso/US dollar